AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 133 PM MDT SUN JUL 22 2007 .SHORT TERM...TONIGHT THROUGH TUESDAY... DEEP EASTERLY FLOW IN PLACE OVER THE FORECAST AREA TODAY AS UPPER LEVEL RIDGING HOLDS STRONG OVER THE CENTRAL PLAINS. THIS IS DRIVING SOME DRIER AIR WESTWARD OVER THE DIVIDE AND INTO WESTERN COLORADO. IN ADDITION...KBOU 12Z SOUNDING SHOWED A WEAK CAP ALOFT...SIMILAR TO KGJT...WHICH HAS SLOWED THE CONVECTION DOWN A TAD THIS AFTERNOON. HOWEVER...CONVECTIVE TEMPS ARE BEING HIT THIS AFTERNOON...AND THE KGJX RADAR IS STARTING TO HEAT UP...WITH ACTIVITY FIRING OVER THE SAN JUANS AND NORTHERN MOUNTAINS. THIS TREND WILL CONTINUE THROUGH LATE THIS AFTERNOON WITH MORE ACTIVITY DEVELOPING. STORM MOTION REMAINS LIGHT...WITH GENERAL MOVEMENT OFF TO THE WEST AT LESS THAN 10 MPH. PRECIPITABLE WATER VALUES AT KGJT WERE STILL AROUND ONE INCH THIS MORNING...BUT MUCH LOWER AT KBOU WITH JUST UNDER 0.70 INCHES. STILL DECENT MOISTURE TO WORK WITH...BUT WIDESPREAD HEAVY RAIN PRODUCING THUNDERSTORMS ARE NOT EXPECTED. CONVECTION CONTINUES INTO THE LATE EVENING HOURS TONIGHT...WITH ISOLATED ACTIVITY EXPECTED TO PERSIST UNTIL THE EARLY MORNING HOURS ON MONDAY. THE LATEST WRF AND RUC RUNS INDICATING A WEAK DISTURBANCE WILL BE HEADING WEST OVER THE CENTRAL PORTIONS OF THE FORECAST AREA LATE TONIGHT. AS A RESULT...HAVE TRIMMED POPS BACK ACROSS THE NORTHERN AND SOUTHERN ZONES...AND LEFT AN AREA OF SLIGHTLY HIGHER POPS OVER THE CENTRAL ZONES. CONDITIONS STABILIZE EARLY MORNING MORNING...WITH DRY WEATHER EXPECTED THROUGH MIDDAY...BEFORE CONDITIONS AGAIN DESTABILIZE MONDAY AFTERNOON. NO MAJOR ADJUSTMENTS NEEDED TO THE FORECAST AS CONVECTION WILL ONCE AGAIN BE OF THE SCATTERED TO NUMEROUS VARIETY...WITH BEST ACTIVITY OVER THE SAN JUANS. ANOTHER SURGE OF MOISTURE IS EXPECTED LATER MONDAY NIGHT AND TUESDAY AS THE RIDGE UNDERGOES SOME REPOSITIONING AS A RESULT OF SHRTWV ENERGY PASSING ACROSS THE NORTHERN U.S. AND SOUTHERN CANADA. AS THESE WAVES PASS TO OUR NORTH...THE RIDGE FLATTENS SLIGHTLY...ALLOWING SUBTROPICAL MOISTURE TO OUR SOUTH TO GET DRAWN BACK NORTHWARD AND INTO THE FORECAST AREA. AS A RESULT...HAVE INCREASED DIURNAL POPS ON TUESDAY TO ACCOUNT FOR THIS RETURN SURGE. TEMPERATURES WILL REMAIN ON THE WARM SIDE OF NORMAL THROUGH THE PERIOD. .LONG TERM...TUESDAY NIGHT THROUGH SATURDAY NIGHT... HIGH PRESSURE CENTERED TO THE NORTHEAST WILL GRADUALLY SHIFT TO OUR SOUTHWEST BY THE END OF THE WEEK. WHILE CHANCE OF PRECIP WILL CONTINUE THROUGH THE PERIOD MID WEEK HAS THE BEST COVERAGE WITH INCREASED MOISTURE AND A WEAK SHORTWAVE INDICATED MOVING THROUGH THE RIDGE. IF MODELS HOLD TRUE COULD SEE BREAK IN HIGH COUNTRY POPS WITH NORTHWEST FLOW IN PLACE. CURRENT FORECAST COVERS THIS SITUATION WELL SO ONLY MADE MINOR TWEAKS IN THE PACKAGE. DJC/21 && .AVIATION... SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS EXPECTED THROUGH MIDWEEK...MAINLY DURING AFTERNOON AND EVENING HOURS...WITH THE HIGHEST AREAL COVERAGE SOUTH OF INTERSTATE 70. ALTHOUGH VFR CONDITIONS ARE EXPECTED TO PREVAIL...SOME STORMS WILL LIKELY PRODUCE MOUNTAIN OBSCURATIONS AND LOCAL MVFR CONDITIONS. && .GJT WATCHES/WARNINGS/ADVISORIES... .CO...NONE. .UT...NONE. $$ SHORT TERM...JDC LONG TERM...DJC AVIATION...JDC co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 330 AM MDT SUN JUL 22 2007 .SHORT TERM (TODAY THROUGH MONDAY NIGHT)... OVERALL WEATHER PATTERN NOT CHANGING MUCH TODAY AND MONDAY. SLIGHTLY DRIER CONDITIONS PREVAIL NORTH OF INTERSTATE 70. SOUTH OF THE INTERSTATE A MOIST EASTERLY FLOW WILL CONTINUE WITH CONVECTION FOCUSED BY WEAK SHORTWAVE TROUGHS ROTATING AROUND THE DOMINANT HIGH. RUC AND NAM12 PICK UP ON 2 SHORTWAVE TODAY WHICH WILL TRAVEL OVER THE SAN JUAN MTS AND SOUTHEAST UT FROM EAST TO WEST...THE FIRST JUST BEFORE NOON AND THE SECOND LATE THIS AFTERNOON AND EVENING. HAVE INCREASED POPS OVER THE SOUTHERN CO AND UT MTS AND CENTRAL CO MTSS AS WELL AS LOWER ELEVATIONS OF THE FOUR CORNERS. MODELS SHOW A SLIGHT DOWNTURN IN PRECIPITATION CHANCES MONDAY WITH LESS MOISTURE FLOW IN FROM THE EAST. THIS MAY PAN OUT AS DRIER CONDITIONS AND LESS CLOUD COVER EVIDENT ON SATELLITE OVER EASTERN CO. WILL STAY BELOW LIKELY POPS AS A RESULT. NOT MUCH CHANGE IN TEMPS EXPECTED NEXT 2 DAYS. .LONG TERM...TUESDAY THROUGH SATURDAY NIGHT... LATEST MODELS ARE NOT QUITE AS QUICK TO MOVE THE RIDGE AXIS TO THE EAST SO THE MOISTURE FLUX IS SLIGHTLY SLOWER TO MOVE IN EARLY TUESDAY ALTHOUGH THERE WILL BE ENOUGH RESIDUAL MOISTURE FOR CONVECTIVE DEVELOPMENT. COVERAGE SHOULD INCREASE LATE TUESDAY INTO WEDNESDAY AS ANOTHER MOISTURE PULSE IS INDICATED. EXPECT THE MIDDLE OF THE WEEK TO HAVE THE MOST COVERAGE AND BETTER CHANCES FOR HEAVY RAINFALL. THE CENTER OF THE RIDGE SHIFTS/REDEVELOPS FARTHER WEST LATE IN THE WEEK RESULTING IN EASTERLY FLOW TO OUR SOUTH CUTTING OFF THE MOISTURE PLUME. THUNDERSTORM COVERAGE SHOULD DECLINE SLIGHTLY ON FRIDAY AND SATURDAY...THEREFORE TRENDED THE POPS ACCORDINGLY. A FEW WEAK DISTURBANCES ARE NOTED IN THE MODELS AND COULD INCREASE LOCAL THUNDERSTORM ACTIVITY LATE IN THE WEEK. NOT ENOUGH CERTAINTY WITH TIMING AND PLACEMENT TO INCREASE CHANCES. TEMPERATURES WILL REMAIN WARM THROUGH THE PERIOD. && .AVIATION... SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS EXPECTED THROUGH MONDAY...MAINLY DURING AFTERNOON AND EVENING HOURS WITH THE HIGHEST AREAL COVERAGE SOUTH OF INTERSTATE 70. ALTHOUGH VFR CONDITIONS ARE EXPECTED TO PREVAIL...SOME STORMS WILL LIKELY PRODUCE MOUNTAIN OBSCURATIONS AND LOCAL MVFR CONDITIONS. && .GJT WATCHES/WARNINGS/ADVISORIES... .CO...NONE. .UT...NONE. $$ SHORT TERM...CJC LONG TERM...AS AVIATION...CJC co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBANY NY 725 PM EDT MON JUL 23 2007 .SYNOPSIS... A LOW PRESSURE AREA IN THE MID LEVELS OF THE ATMOSPHERE WILL MEANDER ACROSS THE MID ATLANTIC AND GREAT LAKES STATES MUCH OF THE WEEK. EMBEDDED DISTURBANCES ROTATING AROUND IT...COMBINED WITH THE DAYTIME HEATING CYCLE WILL BRING THE THREAT OF SCATTERED SHOWERS AND THUNDERSTORMS MUCH OF THE WEEK...BUT MOST OF THE TIME IT WILL BE DRY. WEAK LOW PRESSURE WILL MOVE FROM THE NJ COAST THIS AFTERNOON TO THE HUDSON VALLEY AND DISSIPATE OVERNIGHT. TUESDAY INTO THURSDAY A SOUTHERLY FLOW OR WARM HUMID AIR WILL BECOME ESTABLISHED ACROSS THE REGION...WHILE THIS MID LEVEL LOWS DRIFTS BACK TOWARD MICHIGAN. && .NEAR TERM /THROUGH TONIGHT/... SFC LOW PRESSURE OFF NJ WILL DRIFT NORTH AND DISSIPATE IN THE HUDSON VALLEY OVERNIGHT. AN AREA OF OVERRUNNING -RN AHEAD OF IT COVERS MUCH OF NYS F THE MHWK VLY SOUTH...AND THIS AREA IS LIFTING TO THE NW. THIS AREA WILL CONTINUE TO DO SO...DIMINISHING TO SCT -SHRA DURING THIS EVENING. THE BULK OF THE HEAVIEST RN WITH THIS AREA WILL EXIT TO THE NW OUT OF THE REGION IN A FEW HRS...OTHERWISE OUTSIDE OF THE S TIER OF NYS MOST AREAS WILL HAVE SCT -SHRA INTO THIS EVNG. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... GFS/NAM PRETTY MUCH IN AGREEMENT THROUGH THIS PERIOD. 500 HPA CUT OFF LIFTS NW FM VIRGINIA TO OHIO...AND BULK TO SHORT WVS ROTATING AROUND IT ARE ON THE CUT OFFS WEST SIDE INTO TUESDAY NIGHT. WEAK FLOW OF MARITIME TROPICAL AIR INTO REGION SETS UP AND WHILE THREAT OF -SHRA PERSISTS...BEST CHANCE TUES IS DURING THE AFTN IN RESPONSE TO HEATING CYCLE...AS THERE ARE NO SHORT WVS PASSING ACROSS THE REGION. WEDNESDAY INTO THURSDAY THE CUT OFF DRIFTS FM OHIO TWRD THE LOWER PENINSULA OF MICHIGAN. WHILE 500 HPA SHORT WVS CONTINUE TO ROTATE AROUND THE CUTOFF...THE BULK OF THE FORCING THEY PRODUCE REMAINS TO THE W OF...OR ALONG THE WESTERN PERIPHERY OF FCA. SO FCA WILL BE IN VRBL CLOUDINESS...WITH WARM AND HUMID BUT NOT HOT CONDS THE BULK OF THE WEEK. THERE`LL BE A MORE CLOUDS TO THE WEST AND MORE SUN TO THE NE IN THE FCA WITH A FEW DEGREES DIFFERENCE IN TEMPS ASA RESULT...AND AGAIN THE THREAT OF SWRA WILL BE BEST IN THE AFTN AND EVNG. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... THURSDAY NIGHT THE CUTOFF OPENS UP...THEN SLOWLY PROGRESSES EAST FM MICHIGAN ACROSS THE NE USA. SAT INTO SAT NIGHT A CDFNT DROPS SOUTH THROUGH THE REGION SLOWLY. UNTIL THIS FROPA...MORE OF THE SAME...VRBL CLOUDS...SCT -SHRA/TSTMS. SUNDAY CONDITIONS GRADUALLY IMPV AS SFC HIGH BUILDS IN...AND SOUPY AIRMASS IS DISPLACED TO THE SOUTH. AS THIS IS A CUT OFF...AND MDLS RESOLUTION OF BIT THIS FEATURE AS WELL AS THE EMBEDDED SHORT WVS IS PROBLEMATIC...SHIFTS IN THIS FEATURES LOCATION...COULD HAVE SIGNIFICANT RESULTS OF THE FCST OVER TIME. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... LOWERING CEILINGS AND THE ONSET OF DRIZZLE/MIST WILL MAKE FOR MAINLY MVFR TO IFR CONDITIONS OVERNIGHT. AS SURFACE LOW TRAVELS INLAND ACROSS EASTERN NY...WINDS WILL RELAX TO LIGHT AND VARIABLE WHICH WILL ONLY ENHANCE THE POTENTIAL FOR IFR CIGS AND VISIBILITIES. HOWEVER...ALOFT...EAST WINDS WILL BE A BIT STRONGER AND WILL INCLUDE WIND SHEAR FOR A BRIEF TIME THIS EVENING (ALREADY SEEING EVIDENCE ON THE VWP THIS EVENING). THEN IT WILL INTERESTING TO SEE HOW MUCH BREAKS IN THE CLOUD COVER OCCUR DURING TUESDAY. LATEST EXPERIMENTAL RUC SOUNDINGS ONLINE AND 18Z RUN OF THE NAM SUGGEST THE LOW LEVEL MOISTURE WILL BE HARD TO SCOUR OUT YET THE 18Z GFS POINTS TOWARD RAPID IMPROVEMENT TO VFR. AT THIS TIME...PREFER TO KEEP WITH THE MVFR CEILINGS BUT IMPROVE THE VISIBILITIES TO VFR ON TUESDAY. OUTLOOK... TUE NIGHT...AREAS MVFR/IFR DUE TO PATCHY FOG. WED...VFR/MVFR...SLIGHT CHANCE OF PM SHOWERS/THUNDERSTORMS. THU...VFR/MVFR...SLIGHT CHANCE OF PM SHOWERS/THUNDERSTORMS. FRI...VFR/MVFR...SCT SHOWERS/THUNDERSTORMS. SAT...VFR/MVFR...SCT SHOWERS/THUNDERSTORMS. && .HYDROLOGY... 0.4 TO 0.6 INCH OF RAIN HAS FALLEN OVER THE CATSKILLS...THE MID HUDSON REGION OF NY...AND NORTHWESTERN CONNECTICUT DURING THE LAST 6 TO 9 HOURS. TOTAL RAINFALL WILL GENERALLY RANGE FROM LESS THAN 0.2 INCH IN THE NORTH AND WEST TO SLIGHTLY OVER AN INCH SOUTH AND EAST. MOST OF THIS RAIN WILL SOAK IN THE GROUND. TRIBUTARIES TO THE HOUSATONIC IN CONNECTICUT AND THE HUDSON IN NEW YORK WILL RISE A FOOT OR TWO BUT REMAIN WELL BELOW BANKFULL. SOME MINOR PONDING MAY OCCUR ON ROADS AND PARKING AREAS BRIEFLY DURING PERIODS OF HEAVIER RAIN. A BERMUDA HIGH WILL BEGIN TO BUILD IN ON TUESDAY WITH A BRIEF PERIOD OF DRY WEATHER OVER THE REGION INTO WEDNESDAY. IT WILL BECOME PROGRESSIVELY WARMER AND MORE HUMID WITH AN INCREASING CHANCE OF AFTERNOON THUNDERSTORMS. PRECIPITABLE WATER VALUES WILL BE RUNNING IN THE 1.50-2.00" RANGE...SO SOME LOCALIZED HEAVY DOWN POURS WILL BE POSSIBLE. A COLD FRONT WILL SLOWLY DROP SOUTHWEST FROM THE ST LAWRENCE RIVER VALLEY ON SATURDAY WITH A MORE WIDE- SPRED CHANCE OF SHOWERS AND THUNDERSTORMS SATURDAY INTO SUNDAY. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SNYDER/KILPATRICK AVIATION...BGM WWW.WEATHER.GOV/ALBANY ct AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBANY NY 112 PM EDT SUN JUL 22 2007 .SYNOPSIS... WEAKENING HIGH PRESSURE WILL CREST OVER OUR REGION AND PROVIDE ANOTHER BEAUTIFUL MID SUMMER DAY. THE HIGH WILL THEN DRIFT OFF SHORE...AND ALLOW AN UPPER DISTURBANCE TO OUR SOUTH...TO MOVE NORTH AND BRING ANOTHER ROUND OF SHOWERS OR EVEN STEADY RAIN BY LATE MONDAY...ESPECIALLY SOUTH OF ALBANY. && .NEAR TERM /THROUGH TODAY/... AFTER A RATHER CHILLY START WITH LOWS RANGING FROM 45 TO 55 DEGREES...JULY SUNSHINE AND MAINLY CLEAR SKIES HAS RESULTED IN A RATHER QUICK JUMP TO THE TEMPERATURES AS WE ARE WELL INTO THE 60S AS OF 14Z. HI RES VISIBLE IMAGERY REVEALS THE ISOLATED VALLEY FOG LOCATIONS HAVE CLEARED OUT WITH SOME SCT-BKN CI/CS ACROSS PORTIONS OF THE CWA (A LITTLE THICKER CI/CS ACROSS THE MID-LOWER HUDSON VALLEY AND NORTHWEST CONNECTICUT). LATEST RUC ALONG WITH OUR 12Z SOUNDING POINTS TOWARD A DRIER AND MORE STABLE ENVIRONMENT AND WILL KEEP SKIES MOSTLY SUNNY. HIGH LEVEL MOISTURE IS EXPECTED TO CONTINUE INCREASING AND ADVECT FROM SOUTHEAST TO NORTHWEST WITH SOME DIURNAL CU EXPECTED. MAX TEMPS BASED ON MIXING LEVEL HEIGHTS OF 750MB POINT TOWARD LOWER 80S IN THE VALLEYS AND CURRENT FORECAST LOOKS GOOD AT THIS TIME. && .SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... AS USUAL...THE PROBLEM IN THE SHORT TERM WILL BE WHERE EXACTLY THIS SURFACE WAVE AND RESULTANT WARM CONVEYOR BELT FORMS. THIS WILL DETERMINE WHERE THE HEAVIEST QPF WILL TAKE PLACE. THE 00Z NAM IS MUCH MORE AGGRESSIVE...GIVING SOME OF OUR SOUTHERN AREAS SEVERAL INCHES OF RAINFALL. THE GFS HAS A LOT QPF. MORE ABOUT THIS WILL BE DISCUSSED IN OUR HYDRO SECTION. WE WILL KEEP IT DRY TONIGHT WITH A GRADUAL INCREASE IN HIGH CLOUDS...AND BRING THE RAIN IN FROM SOUTHEAST TO NORTHWEST TOMORROW WITH THE HIGHEST POPS (LIKELY) CONFINED TO SOUTH AND EAST OF ALBANY. LIKELY FROM ABOUT THE CAPITAL DISTRICT SOUTHWARD MONDAY NIGHT. MOST MODELS ACTUALLY WEAKEN THE SURFACE WAVE AS THE ROLL IT UP THE COAST IN OR A BIT INLAND ON TUESDAY...PROBABLY IN RESPONSE TO THE FACT THE THE UPPER AIR IS FORECAST TO MOVE SOUTHWEST...WHILE THE ENERGY LIFTS NORTHEAST...AWAY FROM THE UPPER AIR LOW CENTER. ALSO...SOMEWHAT DRIER AIR...AT LEAST IN THE MID LEVELS. && .LONG TERM /TUESDAY THROUGH SATURDAY/... OF COURSE ANOTHER BIG QUESTION IS WHERE EXACTLY WILL THIS CUTOFF LOW END UP? THE LATEST GFS HAS RE-INTRODUCED THE IDEA OF IT RETROGRADING WELL SOUTH AND WEST (NOT AS FAR AS IA) BUT AT LEAST TO KY LATER IN THE WEEK. THE NAM IS NOT FAR WEST WITH THE RETROGRESSION. AT THIS POINT IT IS PROBABLY MUTE TO WORRY TO MUCH ABOUT EXACTLY WHERE IT GOES. ONE THING LOOKS SOMEWHAT CERTAIN TO US IS THAT THE COLDEST POOL OF AIR ALOFT... SHOULD STAY WEST. THEREFORE THE MOST UNSTABLE AIR SHOULD AS WELL. MEANWHILE...IT LOOKS AS IF INCREASINGLY HUMID AND WARM AIR WILL ATTEMPT TO BUILD IN FROM THE EAST (A TROPICAL MOIST AIR MASS). THEREFORE AT THIS TIME...WILL KEEP SLIGHT CHANCES OF CONVECTION IN TUESDAY THROUGH SATURDAY. FOR NOW...WILL IN SOME CASES DIURNALLY TIME THE SLIGHT CHANCE (AFTERNOON AND EARLY EVENING HOURS). AS MENTIONED IN THE PREVIOUS DISCUSSION CHECK BACK ON THE EVOLUTION OF THE THIS UPPER AIR LOW. OTHER THAN THAT...NO CHANGES FROM THE PREVIOUS PACKAGE. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... VFR CONDITIONS PREVAIL FOR THE REMAINDER OF THE AFTERNOON AND INTO THE EVENING HOURS. TROUGH OVERHEAD WILL BECOME BISECTED AS THE MAIN BRANCH LIFTS NORTHEAST LEAVING IN ITS WAKE A CUT OFF UPPER LOW. DEEP TROPICAL MOISTURE OFF THE SOUTHEAST CONUS IS FORECAST TO SPREAD NORTHWEST OVERNIGHT AROUND THE PERIPHERY OF THIS CUT OFF UPPER LOW WITH INCREASING MID AND HIGH LEVEL CLOUDS. POTENTIAL RAINFALL WITH THIS SYSTEM REMAINS IN QUESTION BUT FEEL A VCSH FOR POU IS WORTH MENTIONING AT THIS TIME FOR MONDAY MORNING WHERE DEEPER MOISTURE IS EXPECTED. WINDS WILL REMAIN RATHER LIGHT WITH A PREDOMINANT DIRECTION FROM THE NORTH-NORTHEAST. MON...VFR/MVFR...CIG AND SCT SHRAS. TUE...VFR/MVFR...CIG AND SLIGHT CHANCE OF SHOWERS/PM THUNDERSTORMS. WED...VFR/MVFR...SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS. THU...VFR/MVFR...SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS. FRI...VFR/MVFR...CHC-SCT SHOWERS/THUNDERSTORMS. && .FIRE WEATHER... SURFACE HIGH PRESSURE CENTERED OVER THE WESTERN GREAT LAKES EXPECTED TO BRING DRY WEATHER TO THE REGION THROUGH TONIGHT...BUT AND UPPER LOW OVER THE MID ATLANTIC STATES WILL BRING MOISTURE AND SHOWERS BACK TO THE REGION MONDAY AND MONDAY NIGHT. RELATIVE HUMIDITY LEVELS WILL LOWER TO 30 TO 40 PERCENT TODAY...RECOVER TO 90 TO 100 PERCENT TONIGHT...AND ONLY LOWER TO BETWEEN 55 AND 75 PERCENT ON MONDAY. SURFACE WINDS WILL BE NORTHERLY TODAY 5 TO 15 MPH...BECOME LIGHT TONIGHT...AND NORTHEAST 5 TO 15 MPH ON MONDAY. && && .HYDROLOGY... NO RAINFALL EXPECTED THROUGH SUNDAY NIGHT DESPITE UPPER LEVEL TROUGH BEING IN CLOSE PROXIMITY TO THE REGION. SURFACE HIGH PRESSURE WILL KEEP LOW LEVELS TOO DRY FOR SHOWER DEVELOPMENT. THE TROUGH IS EXPECTED TO EVOLVE INTO A CUTOFF LOW WHICH WILL LIKELY FORM OVER THE MID ATLANTIC STATES. THIS SYSTEM EXPECTED TO BRING AN INCREASE IN MOISTURE AND SHOWERS/RAIN TO THE AREA ON MONDAY AND MONDAY NIGHT. MODELS VARY GREATLY IN HOW MUCH RAIN. WRF MODEL HAS HEAVIEST RAIN WITH UP TO 4 INCHES FORECAST OVER THE SOUTHEAST CATSKILLS. GFS MUCH LIGHTER WITH AMOUNTS LESS THAN AN INCH IN ALL AREAS. TOO EARLY TO TELL WHICH MODEL IS BETTER...BUT THERE COULD BE HYDRO PROBLEMS EARLY NEXT WEEK DEPENDING ON HOW THIS SYSTEM EVOLVES. UNTIL THEN...RIVER FLOWS ARE EXPECTED TO REMAIN AT NORMAL TO BELOW NORMAL LEVELS FOR LATE JULY. FOR NOW...WE HAVE INCLUDED A 24-HR STORM RAINFALL TOTAL (12Z MON TO 12Z TUES) OF AROUND 2 INCHES IN OUR SOUTHERN AREAS...AROUND AN INCH LOCALLY IN THE CAPITAL DISTRICT AND ABOUT HALF THAT NORTH. BY THE WAY...THE INCOMING 06Z NAM HAS SHIFTED THE AXIS OF HEAVIEST PCPN FURTHER SOUTH...WHILE CUTTING BACK THE TOTAL 24-HR QPF BY MORE THAN HALF! UNCERTAINTIES CONTINUE TO ABOUND. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...HWJIV NEAR TERM...BGM SHORT TERM...HWJIV LONG TERM...HWJIV AVIATION...BGM FIRE WEATHER...MAGLARAS HYDROLOGY...MAGLARAS WWW.WEATHER.GOV/ALBANY ct AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 335 PM EDT MON JUL 23 2007 .SYNOPSIS... 18Z WATER VAPOR AND H4 RUC ANALYSIS CONTINUE TO SHOW A VERY AMPLIFIED PATTERN ACROSS THE CONUS WITH A HUGE DOMINANT RIDGE ACROSS THE WESTERN 2/3RDS OF COUNTY AND DEEP TROUGHING ALONG THE EAST COAST ALL THE WAY TO THE NORTHEAST GULF. CLOSED LOW CONTOUR IS NOW COVERING THE AREA FROM VIRGINA TO NORTH CAROLINA AND REMAINS VERY UNUSUAL FOR LATE JULY...MORE REMINISCENT OF A MID TO LATE SPRING PATTERN. AT THE SURFACE STILL LOOKING AT A WEAK AND STATIONARY BOUNDARY LYING EAST TO WEST FROM CENTRAL FLORIDA INTO THE NORTH-CENTRAL GULF OF MEXICO AND THEN BACK TOWARD THE TEXAS/LOUISIANA COAST. AN ADDITIONAL SURFACE TROUGH IS RUNNING FROM THE NORTH-CENTRAL GULF OF MEXICO NORTHWARD ALONG THE AL/MS BORDER. TO THE NORTH AND EAST OF THESE BOUNDARIES WE SEE DRIER EASTERLY FLOW. SHOWERS AND THUNDERSTORMS CONTINUE VERY ACTIVE ACROSS THE COASTAL WATERS THIS AFTERNOON. STORMS HAD BEEN GENERALLY STAYING OFFSHORE WITH THE EXCEPTING OF A FEW SHOWERS CLOSE TO APALACHICOLA...HOWEVER RECENT TRENDS HAVE BEEN FOR A FEW THUNDERSTORMS TO REACH THE PANHANDLE BEACHES. THIS IS LIKELY TO BE THE CASE INTO THE EARLY EVENING WITH THE MAJORITY OF THE RAINFALL OVER LAND BEING CONFINED TO THE NEAR-COAST AREAS OF THE EASTERN PANHANDLE. WITH THE DRIER LOW LEVEL EASTERLY FLOW AND AN UNFAVORABLE THERMODYNAMIC PROFILE BASED ON MORNING SOUNDING DATA STILL EXPECT A VERY INACTIVE REST OF THE DAY IN TERMS OF CONVECTION ACROSS MOST INLAND LOCATIONS. ONLY OTHER PLACES TO WATCH WILL BE ACROSS THE FAR SOUTHEASTERN FL BIG BEND CLOSER TO THE SURFACE BOUNDARY AS SHOWERS AND STORMS HAVE DEVELOPED SOUTH OF OUR AREA AND ARE TRYING TO BUILD NORTH WITH TIME. ALSO NUMEROUS STORMS ARE UNDERWAY WITHIN THE SURFACE TROUGH OVER CENTRAL AL. A FEW OF THESE STORMS MAY TRY TO BUILD EAST INTO COFFEE AND GENEVA COUNTIES EARLY THIS EVENING. MID/HIGH LEVEL CLOUD-COVER HAS BEEN QUITE ROBUST TODAY ACROSS THE BIG BEND AND PANHANDLE ASSOCIATED WITH THE NORTHEASTWARD BLOWOFF FROM THE OFFSHORE CONVECTION AND MOSTLY CLOUDY SKIES WILL CONTINUE INTO THE EVENING ACROSS THESE AREA WHILE CONTINUING TO EXPAND NORTH AND EAST. && .SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)... SURFACE BOUNDARY TO THE SOUTH OF THE COASTAL WATERS BEGINS TO LIFT NORTH TONIGHT REACHING THE COAST TOWARD DAYBREAK. THIS SHOULD KEEP THE SHOWERS AND THUNDERSTORMS GOING OVER THE WATERS. KEPT CHANCE POPS IN ALONG THE COAST DUE TO THE CLOSE PROXIMITY OF THESE SHOWERS AND STORMS AND THE LIKELIHOOD THAT A FEW WILL MIGRATE ONSHORE AT TIMES. DID NOT DEVIATE MUCH FROM MOS FOR TONIGHTS LOW WITH GENERALLY UPPER 60S TO NEAR 70 INLAND IN LOWER 70S ALONG THE COAST. BIG DIFFERENCES IN GUIDANCE FOR TUESDAY CONTINUE. THE UPPER PATTER WILL FEATURE THE EAST COAST TROUGH BEGINNING TO LOSE INFLUENCE OVER THE AREA. SURFACE TROUGH WILL BECOME SITUATED DIRECTLY OVERHEAD DURING THE DAY AND SHOULD BE THE FOCUS FOR QUITE ACTIVE CONVECTION DURING THE LATE MORNING AND AFTERNOON. SHOWERS AND THUNDERSTORMS MAY BE MORE OF AN ALL DAY EVENT CLOSE TO THE COAST. ONCE AGAIN THE MAV IS THE WETTER SOLUTION SHOWING HIGH CHANCE TO LIKELY POPS ACROSS THE ENTIRE FORECAST AREA. THE MET ON THE OTHER HAND IS CONSIDERABLY DRIER SHOWING A VERY INACTIVE DAY. REALLY CAN NOT MAKE AN ARGUMENT FOR GOING WITH THE LOWER POPS AT THIS TIME. INHERITED POPS WERE CLOSE TO THE MAV AND WILL LEAN HEAVILY TOWARD THIS SOLUTION FOR THE AFTERNOON HOURS. HERE ARE THE REASONS. SURFACE TROUGH MENTIONED ABOVE WILL BECOME A SYNOPTIC FOCUS FOR CONVERGENCE. IN ADDITION FORECAST SOUNDING PROFILES ARE MUCH MORE CONDUCIVE FOR CONVECTION. MODIFYING THE GFS 18Z SOUNDING FOR KTLH (WHICH SHOULD BE FAIRLY REPRESENTATIVE OF THE AREA) SHOWED OVER 2000 J/KG OF CAPE FOR A SURFACE PARCEL OF 90/68F. PW VALUES RISE TO AROUND 1.8" (CLOSE TO CLIMO) AND ALTHOUGH WEAKENING THERE WILL STILL BE SOME CYCLONIC INFLUENCE OF THE UPPER TROUGH. RAN HIGH TEMPERATURES A FEW DEGREES BELOW CLIMO WITH UPPER 80S TO NEAR 90 COMMON AS DO EXPECT ENOUGH CLOUDCOVER TO LIMITED DIURNAL HEATING. SURFACE TROUGH LIFTS NORTH OF THE FORECAST AREA TUESDAY NIGHT WITH THE SUBTROPICAL RIDGE AXIS ONCE AGAIN TRYING TO BUILD NORTH TOWARD THE AREA. WITH THE BOUNDARY GONE DO NOT EXPECT QUITE THE EXTENT OF OFFSHORE CONVECTION AND SHOULD SEE LAND BASED CONVECTION BECOME ISOLATED IN NATURE BY AROUND MIDNIGHT. LOWS TEMPS WILL BE UP A FEW DEGREES INTO THE LOWER 70S WITH THE HIGHER MOISTURE AND SOUTHERLY FLOW. A MORE TYPICAL SUMMER DAY SHAPING UP FOR WEDNESDAY INTO WEDNESDAY NIGHT WITH THE SUBTROPICAL RIDGE AXIS BUILDING DIRECTLY OVERHEAD. THIS WILL RESULT IN LIGHTER FLOW AND A BLEND BETWEEN A TYPE 1 AND TYPE 6 REGIME. THESE REGIMES FAVOR CLIMO POPS IN THE 40-50% RANGE OVER OUR FLORIDA ZONES AND SOUTHEAST ALABAMA...AND SLIGHTLY LOWER POPS FOR GEORGIA. DECIDED TO KEEP THINGS A BIT MORE UNIFORM WITH NEAR 50 POPS FOR ALL AS WOULD EXPECT THERE TO BE PLENTY OF RESIDUAL BOUNDARIES FROM TUESDAYS CONVECTION TO HELP AID DEVELOPMENT ACROSS GEORGIA. HIGH TEMPERATURES SHOULD TOP OUT NEAR CLIMO AS WELL WITH LOWER 90S COMMON. && .LONG TERM (THURSDAY THROUGH MONDAY)... UPPER LOW CONTINUES TO MEANDER IN THE OHIO RIVER VALLEY UNTIL THURSDAY EVENING WHEN AN APPROACHING TROF MOVING THROUGH CENTRAL CANADA APPROACHES. THE CLOSED LOW WILL OPEN UP AND PHASE IN WITH THE TROF AND KICK OUT TO SEA. ANOTHER TROF WILL TAKE ITS PLACE ACROSS THE EASTERN CONUS AND TRY ONCE AGAIN TO DRIVE A FRONTAL BOUNDARY INTO THE SOUTHEAST. LOW LEVEL FLOW ACROSS THE REGION WILL CONTINUE TO STAY SOUTHERLY KEEPING PLENTY OF MOISTURE IN PLACE...ESPECIALLY BY THE WEEKEND AS MOISTURE BEGINS TO POOL AHEAD OF THE APPROACHING FRONTAL BOUNDARY. AT THIS TIME...THE MODELS ARE KEEPING THE FRONT ACROSS THE TENNESSEE VALLEY...BUT PERSISTENT SOUTHERLY FLOW WILL KEEP POPS HIGH THROUGH THE WEEKEND...WITH NEAR 50 PERCENT POPS BY SATURDAY AND SUNDAY. TEMPERATURES WILL ALSO BE COOLER THAN LAST WEEK...GENERALLY A DEGREE OR TWO BELOW CLIMATOLOGY IN THE UPPER 80S TO LOWER 90S DUE TO ALL THE CONVECTION ONGOING. && .AVIATION... VFR CONDITIONS WILL PREVAIL THROUGH THE REMAINDER OF THE AFTERNOON AND OVERNIGHT FOR MOST LOCATIONS. EXCEPTION WILL BE KPFN WHICH HAS THE BEST SHOT AT CONVECTION AND MVFR CONDITIONS THROUGH THE REMAINDER OF THE AFTERNOON AND OVERNIGHT. && .MARINE... NUMEROUS SHOWERS AND THUNDERSTORMS CONTINUE ACROSS THE COASTAL WATERS TO THE NORTH OF A WEAK SURFACE BOUNDARY. LOW LEVEL WIND FIELDS ARE FROM THE SOUTHEAST BETWEEN 10 AND 15 KNOTS...HOWEVER WIND GUSTS WITHIN SOME OF THE STORMS HAVE BEEN MEASURED BETWEEN 20 AND 30 KNOTS AT TIMES. THE WEAK SURFACE BOUNDARY SLOWLY MOVES NORTH INTO THE COASTAL WATERS OVERNIGHT AND THIS IS LIKELY TO KEEP THE SHOWERS AND STORMS GOING INTO AT LEAST EARLY TUESDAY MORNING. THE BOUNDARY THEN MOVES NORTH OF THE WATERS BY TUESDAY NIGHT ALLOWING THE SUBTROPICAL RIDGE AXIS TO ONCE AGAIN BUILD NORTH FROM WEDNESDAY INTO THE EARLY PORTION OF THE WEEKEND. WITH THE SURFACE RIDGE AXIS IN THE VICINITY...WINDS WILL GENERALLY REMAIN BELOW CAUTION CRITERIA. && .FIRE WEATHER... RED FLAG WARNING FOR INLAND PORTIONS OF THE FLORIDA BIG BEND IS GOING TO BE CLOSE. VERY STUBBORN HIGH LEVEL CLOUDS STREAMING NORTHEAST FROM OFFSHORE CONVECTION HAS KEEP TEMPS A FEW DEGREES COOLER THAN EARLIER THOUGHT AND PREVENTED SOME MIXING OF DRIER AIR FROM ALOFT. STILL RH VALUES ARE IN THE UPPER 30S TO LOWER 40S ACROSS THE WARNING AREA AND WITH HIGH DISPERSION VALUES ONLY AN HOURS IS NEEDED. MAY STILL GET THIS THROUGH 7 PM EDT AND SO DECISION HAS BEEN MADE TO LEAVE WARNING ALONE. THEREAFTER INCREASING MOISTURE ON SOUTHEAST TO SOUTH FLOW AND BETTER RAIN CHANCES INTO THE MIDDLE OF THE WEEK WILL HELP KEEP CRITICAL FIRE WEATHER CONDITIONS FROM BEING REACHED. && .PRELIMINARY POINT TEMPS/POPS... TALLAHASSEE 69 90 71 90 72 / 20 60 30 50 30 PANAMA CITY 74 88 76 90 75 / 40 60 30 40 30 DOTHAN 69 90 71 90 71 / 20 60 40 50 30 ALBANY 67 91 69 91 71 / 10 50 30 50 30 VALDOSTA 67 91 70 91 71 / 10 50 30 50 30 CROSS CITY 69 90 70 91 72 / 30 60 30 50 30 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR THE FOLLOWING ZONES: GADSDEN...JEFFERSON...LEON...MADISON. GM...NONE. $$ PUBLIC/MARINE...MROCZKA AVIATION/FIRE WX...CAMP LONG TERM...GODSEY/RUBIO fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 300 PM EDT SUN JUL 22 2007 .SYNOPSIS... 17Z WATER VAPOR AND H4 RUC ANALYSIS SHOW A VERY AMPLIFIED PATTERN ACROSS THE CONUS WITH A HUGE DOMINANT RIDGE ACROSS THE WESTERN 2/3RDS OF COUNTY AND A DEEP TROUGH ALONG THE EAST COAST ALL THE WAY TO THE NORTHEAST GULF. THE DEEP TROUGH AND NOW CLOSED LOW OVER THE MID-ATLANTIC STATES IS VERY UNUSUAL FOR LATE JULY AND IS MORE REMINISCENT OF A MID TO LATE SPRING PATTERN. AT THE SURFACE WE SEE THE REMNANTS OF AN OLD FRONTAL BOUNDARY STALLED ACROSS NORTH-CENTRAL FLORIDA WESTWARD INTO OUR COASTAL WATERS AND THEN ARCHING BACK INTO SOUTHERN AL. ONCE AGAIN HAVING A FRONT/BOUNDARY SLIP INTO AND THEN SOUTH OF THE GULF COAST IN LATE JULY IS VERY RARE. STRONG CONTINENTAL HIGH PRESSURE WELL TO THE NORTH IS TRYING TO NOSE INTO THE FORECAST AREA BEHIND THE BOUNDARY BUT HAS MADE JUST ABOUT AS MUCH PROGRESS SOUTH AS IS GOING TO HAPPEN. WITH THE UPPER TROUGH AND ASSOCIATED MID LEVEL COOL POOL IN PLACE...TEMPERATURES THIS AFTERNOON ARE A BIT COOLER THAN HAS BEEN SEEN OVER THE PAST WEEK WITH HIGHS STRUGGLING INTO THE LOWER 90S. SHOWERS AND THUNDERSTORMS HAVE DEVELOPED ALONG THE FLORIDA PANHANDLE SEA-BREEZE AND ALSO MIGRATED INTO SOUTH-CENTRAL GA AND THE FLORIDA BIG BEND FROM THE EAST. && .SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)... SHOWERS AND THUNDERSTORMS CONTINUE SCATTERED AROUND THE AREA INTO THE EVENING HOURS. LOCAL WORKSTATION WRF HAS ACTUALLY DONE A VERY GOOD JOB WITH THE CONVECTIVE ACTIVITY THUS FAR TODAY. THE LATEST RUN HAS THE STORMS CONTINUING WELL INTO THE EVENING...ENDING LAST OVER THE WESTERN BIG BEND AND EASTERN PANHANDLE TOWARD MIDNIGHT. MID/UPPER LEVEL TROUGH WILL REMAIN GENERALLY IN PLACE THROUGH THE SHORT TERM WITH THE CLOSED CONTOUR OVER THE MID-ATLANTIC STATES RETROGRADING SLOWLY WEST TOWARD THE TENNESSEE OR OHIO VALLEYS. WEAK BOUNDARY/SURFACE TROUGH JUST TO OUR SOUTH IS FORECAST BY NAM/GFS TO REMAIN ACROSS THE NORTH-CENTRAL FLORIDA PENINSULA...BUT BECOME MORE SOUTHEAST TO NORTHWEST ORIENTED TO OUR WEST ACROSS THE WESTERN FLORIDA PANHANDLE AND CENTRAL ALABAMA THROUGH MONDAY AFTERNOON. MAV GUIDANCE IS CERTAINLY THE WETTER SOLUTION FOR MONDAY ACROSS A LARGE PORTION OF THE AREA WHILE MET/FWC ARE QUITE DRY. MONDAY LOOKS TO BE A MIX OF A TYPE 2 AND TYPE 6 DAYS WITH GENERAL E-SE FLOW BETWEEN 6-10KTS. THESE FLOWS WILL TEND TO FAVOR FLORIDA ZONES UP INTO SOUTHEAST ALABAMA FOR HIGHEST POPS. WOULD SAY BASED ON PATTERN THAT THE MAV IS A BIT HIGH AND THE MET/FWC A BIT LOW ON THEIR POPS. FOR THIS REASON WILL RUN A BLEND OF GUIDANCE WITH A LEAN TOWARD THE WETTER MAV GUIDANCE ACROSS THE WESTERN CWA. LEANING TOWARD THE MAV GUIDANCE HERE SINCE THE SURFACE TROUGH CLOSEST TO OUR WESTERN ZONES IS LIKELY TO FOCUS LOW LEVEL CONVERGENCE AND CONVECTION. CONVECTION MAY ALSO BE SLIGHTLY SUPPRESSED IN THE EAST BY DRIER LOW LEVEL CONDITIONS. MAV GUIDANCE IS SHOWING SURFACE DEWPOINTS FALLING INTO THE UPPER 50S TO LOWER 60S ACROSS INLAND PORTIONS OF GA AND THE FLORIDA BIG BEND BY MID AFTERNOON. THIS SHOULD HELP KEEP INSTABILITY DOWN. IN ADDITION WE MAY BEGIN TO FLIRT WITH CRITICAL FIRE WX CONDITIONS ACROSS THE INLAND BIG BEND IF THESE DEWPOINTS VERIFY. WITH UPPER TROUGH STILL OVERHEAD THE COOL POOL ASSOCIATED WITH IT WILL HAVE SOME IMPACT ON OUR TEMPS. WILL RUN A MOS BLEND HERE AS WELL WHICH GIVES TEMPERATURES A COUPLE OF DEGREES BELOW CLIMO IN THE 89-92 RANGE. SURFACE TROUGH TO OUR SOUTH AND SOUTHEAST BEGINS TO MOVE BACK NORTH DURING MONDAY NIGHT INTO EARLY TUESDAY TIME FRAME. THE GFS IS A BIT FASTER WITH THIS MOVEMENT THAN THE NAM...HOWEVER THE GENERAL PATTERN IS SIMILAR. WITH THE SURFACE TROUGH BACK IN THE VICINITY...FORECAST POPS ARE ACTUALLY REALLY HIGH FOR THE OVERNIGHT TIME FRAME. WITH THE DIFFERENCES IN TIMING BETWEEN MODELS WILL NOT GO QUITE AS HIGH AS THE MAV GUIDANCE WHICH SHOWS 40%+ IN SPOTS ACROSS THE SOUTHERN FORECAST AREA. HOWEVER WILL CERTAINLY NOT LET POPS DROP OFF TO SILENT AND WILL LIKELY KEEP SLIGHT CHANCE POPS ACROSS THE NORTH WITH LOW END CHANCE POPS ACROSS THE SOUTHEAST BIG BEND. WHERE SHOWERS/STORMS MAY BECOME RATHER NUMEROUS DURING THE LATE NIGHT HOURS INTO EARLY TUESDAY IS ACROSS THE COASTAL WATERS CLOSEST TO THE TROUGH AND WHERE CONVECTION IS DIURNALLY FAVORED. TUESDAY STILL LOOKS TO BECOME INCREASINGLY ACTIVE IN TERMS OF CONVECTION. WITH THE SURFACE TROUGH NOW ALMOST DIRECTLY OVERHEAD THE FLOW WILL BECOME RATHER LIGHT IN THE LOWER LEVELS RESULTING IN THE REGIME 1 TYPE DAY. THIS TYPE OF PATTERN IS TYPICALLY QUITE ACTIVE 40-50% COVERAGE ACROSS THE FLORIDA ZONES WITH SLIGHTLY LOWER POPS TO THE NORTH. HOWEVER WITH A SYNOPTIC SURFACE TROUGH ACROSS THE AREA...WILL KEEP POPS A BIT MORE UNIFORM FROM NORTH TO SOUTH. IN FACT WITH THE SURFACE BOUNDARY/SEA-BREEZE FORMATION AND GENERAL SYNOPTIC FLOW THROUGH A DEEP LAYER ASSOCIATED WITH THE UPPER TROUGH...CONVECTIVE ACTIVITY MAY BE HIGHER THAN FORECAST AND WOULD NOT BE SURPRISED TO SEE THESE POPS RISE IN FUTURE FORECASTS. MODIFIED GFS FCST SOUNDING FOR TUESDAY AFTERNOON FOR SURFACE PROFILE OF 90/70F IS SHOWING AROUND 2700 J/KG OF SURFACE BASED CAPE AND PW VALUES RUNNING NEAR CLIMO. THESE PARAMETERS ARE PLENTY FOR ACTIVE CONVECTION AND THE HIGHER CAPE IS POSSIBLY SUPPORTIVE OF A FEW STRONG/SEVERE STORMS. WILL BE RUNNING HIGH TEMPERATURES CLOSER TO THE WARMER MET NUMBERS AS THE MAV IS LIKELY FEELING THE EFFECTS OF ENHANCED CONVECTION RESULTING IN QUITE COOL TEMPS. THIS TIME OF YEAR IF CONVECTION IS DELAYED BY EVEN AN HOUR OR TWO FROM FORECAST OR ENDS UP BEING LESS IN COVERAGE...TEMPERATURE CAN RISE QUITE A BIT ABOVE GUIDANCE. UNTIL A MORE CERTAIN HIGHER POP IS NEEDED WOULD NOT FEEL COMFORTABLE KEEPING HIGHS IN THE MIDDLE AND UPPER 80S. LOOKING AT FAIRLY ACTIVE CONVECTION INTO THE LATER EVENING HOURS TUESDAY BEFORE COVERAGE BEGINS TO DIMINISH AFTER MIDNIGHT. && .LONG TERM... UPPER LOW REMAINS CLOSED OVER THE OHIO VALLEY AND BEGINS TO RETROGRADE INTO THE MISSISSIPPI RIVER VALLEY BY THURSDAY. WITH SOUTHERLY FLOW REMAINING IN PLACE FOR US...POPS WILL CONTINUE TO BE NEAR CLIMATOLOGY OR SLIGHTLY HIGHER. BY THURSDAY NIGHT THE UPPER LOW DROPS INTO THE MID SOUTH AND BEGINS TO APPROACH OUR REGION ON FRIDAY. A SERIES OF IMPULSES WILL ROUND THE BASE OF THE LOW AND COMBINE WITH ACTIVE SEA BREEZES TO YIELD DECENT COVERAGE OF STORMS BOTH FRIDAY AND SATURDAY AFTERNOONS. HIGH POPS CHANCES WILL REMAIN IN THE FORECAST THROUGH THE WEEKEND AS THE UPPER LOW REMAINS PARKED ACROSS THE REGION. FOLLOWED CLOSE TO THE MEX GUIDANCE FOR TEMPS...WHICH END UP BEING JUST SLIGHTLY BELOW CLIMO BASED ON EXPECTED CLOUD COVER AND PRECIP. && .AVIATION... CONVECTION POPPING UP THIS AFTERNOON ALONG THE EDGES OF THE CWA. COVERAGE WILL CONTINUE TO INCREASE THROUGH THE AFTERNOON MAINLY OVER FLORIDA TERMINALS AND KVLD. HAVE ADDED TEMPO FOR THE AFTERNOON FOR THESE SITES. OTHERWISE...VFR CONDITION EXPECTED OVERNIGHT UNTIL LATE WHEN MAY SEE SOME MINOR RESTRICTIONS TO MVFR FROM FOG. && .MARINE... WEAK PRESSURE GRADIENT ASSOCIATED WITH BROAD SURFACE BOUNDARY OVER THE COASTAL WATERS IS FORECAST TO TIGHTEN OVERNIGHT WITH EASTERLY FLOW INCREASING TO JUST UNDER CAUTION LEVELS FROM EAST TO WEST FOR A PERIOD AFTER MIDNIGHT. FLOW WILL BECOME SOUTHEAST ON MONDAY AND CONTINUE INTO EARLY TUESDAY BETWEEN HIGH PRESSURE TO THE NORTHEAST AND A SURFACE TROUGH TO THE SOUTH AND WEST. WITH A WEAK SURFACE TROUGH IN THE AREA MONDAY NIGHT INTO EARLY TUESDAY...SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BECOME QUITE NUMEROUS OVER THE WATERS. SUBTROPICAL RIDGE THEN BUILDS ACROSS THE COASTAL WATERS FOR THE REMAINDER OF THE PERIOD KEEPING WINDS LIGHT FROM THE SOUTH OR SOUTHWEST. && .FIRE WEATHER... A BRIEF BOUT OF DRIER AIR FOR MONDAY AFTERNOON AND EARLY EVENING WILL COMBINE WITH TEMPERATURES INTO THE LOWER 90S TO PRODUCE A PERIOD OF NEAR CRITICAL RELATIVE HUMIDITY VALUES ACROSS PORTIONS OF THE INLAND FLORIDA BIG BEND. DISPERSION INDICES ARE ALSO EXPECTED TO BE RATHER HIGH RESULTING IN THE ISSUANCE OF A FIRE WX WATCH FOR THESE AREAS. INCREASING MOISTURE AND GREATER RAIN CHANCES WILL KEEP FIRE WEATHER CONDITIONS ABOVE CRITICAL LEVELS MONDAY NIGHT THROUGH AT LEAST THE MIDDLE PART OF THE WEEK. && .PRELIMINARY POINT TEMPS/POPS... TALLAHASSEE 68 91 69 91 70 / 30 30 30 50 30 PANAMA CITY 73 90 74 90 75 / 30 40 30 50 30 DOTHAN 68 91 68 91 69 / 20 30 20 50 30 ALBANY 66 92 68 91 69 / 20 20 20 50 30 VALDOSTA 67 91 68 91 69 / 20 20 20 50 30 CROSS CITY 68 91 69 90 70 / 30 40 30 50 30 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...FIRE WX WATCH NOW IN EFFECT FOR LEON...JEFFERSON...MADISON AND GADSDEN COUNTIES FROM 18Z TO 00Z MONDAY AFTERNOON AND EARLY EVENING FOR POSSIBLE DURATIONS OF RELATIVE HUMIDITY AT OR JUST BELOW 35 PERCENT COMBINED WITH HIGH DISPERSIONS NEAR OR ABOVE 75. GM...NONE. $$ PUBLIC/MARINE...MROCZKA AVIATION/FIRE WX...CAMP LONG TERM...GODSEY/RUBIO fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 354 AM EDT SUN JUL 22 2007 ...STRONG TO SVR TSTMS POSSIBLE ACROSS THE AREA AGAIN TODAY... .SYNOPSIS...SHARP UPPER TROF CONTINUES OVER THE E SEABOARD OF THE US WHILE MASSIVE RIDGE CONTINUES OVER THE W 2/3 OF THE COUNTRY. SHORTWAVE CURRENTLY ROTATING THRU BASE OF TROF CONTINUING TO AID CONVECTION OVER THE NE GOMEX AND THE SE GA COAST. IR SAT PIX SHOW COLD CLOUD TOP AREA SHRINKING IN SIZE...BUT EXTENSIVE CLOUD COVER OVER ALL BUT THE NW PORTION OF THE AREA. AT THE SFC... QUASI- STATIONARY FRONT IS LOCATED NEAR THE FL/GA LINE. .SHORT TERM...MODELS SHOW AREA OF DIFFERENTIAL POSITIVE VORTICITY ADVECTION (PVA) LINED UP WELL WITH ENHANCED CLOUD TOPS AND ONGOING PRECIP. THIS PVA RIBBON IS PROGGED TO CONTINUE TO ROTATE SE AROUND BASE OF TROF. ANOTHER...POSSIBLY STRONGER BAND OF PVA IS FCST BY THE RUC TO MOVE INTO SE GA BY NOONTIME. COLDER THAN NORMAL TEMPS ALOFT AND OVERALL INSTABILITY WILL LEAD TO MORE STRONG TO SVR TSTMS TODAY ACROSS THE AREA. AS DRIER AIR CONTINUES TO FILTER INTO THE REGION...OVERALL COVERAGE MAY BE A BIT LESS THAN ON SAT. HOWEVER...INCREASING BULK SHEAR WILL INCREASE HAIL THREAT AND DRIER AIR IN THE MID-LEVELS WILL INCREASE THREAT OF DOWNBURSTS IN STORMS THAT DO DEVELOP. EXPECT GREATEST COVERAGE WILL BE ON NW EDGE OF LINGERING CLOUD AREA AS SECOND SHOT OF PVA MOVES INTO THE AREA. THIS ACTIVITY WILL THEN SPREAD SE AS THE DAY PROGRESSES. ON MON...TSTM ACTIVITY WILL BE MAINLY ACROSS NE FL AS DRY AIR CONTINUES TO FILTER INTO THE AREA FROM THE N. THIS WILL ALSO ALLOW NIGHTTIME LOWS TO DROP INTO THE MID TO UPPER 60S OVER MANY INLAND AREAS. MOS INDICATES THAT LOWER TO MID 60S ARE POSSIBLE...BUT HAVE LEANED CLOSER TO CLIMO FOR NOW DUE TO UNCERTAINTY AS TO EXTENT OF DRYING. FOR TUE...POPS AND TEMPS RETURN TO CLIMO NORMS ACROSS THE AREA. .LONG TERM...HAVE MADE FEW ADJUSTMENTS TO TEMPS OR POPS. NEAR NORMAL TEMPS AND NEAR TO SLIGHTLY ABOVE NORMAL POPS EXPECTED. && .AVIATION...AREA OF SHOWERS AND THUNDERSTORMS NORTH OF JAX HAVE PERSISTED MOST OF THE NIGHT AND ARE DRIFTING SE AND SLOWLY WEAKENING. WILL CONTINUE WITH VCTS AT JAX AND CRG A COUPLE MORE HOURS. WILL ALSO SEE A BRIEF PERIOD OF MVFR FROM CIGS 2000-3000 FT TIL 12Z. AFTER 12Z...WILL BEGIN THE DAY VFR... HOWEVER THE DEEP TROUGH OVER THE AREA AND AFTERNOON HEATING WILL LEAD TO SCATTERED AFTERNOON STORMS AGAIN WITH THE STORMS MOST NUMEROUS ACROSS NE FL DURING THE AFTERNOON AFTER CLOUDS LIFT. HAVE INCLUDED TEMPO GROUPS FOR IFR DUE TO REDUCED VSBY FROM STORMS BETWEEN 20Z-24Z AT ALL TAF SITES. THE STORMS WILL BE LOCALLY STRONG AND HAVE INCLUDED WIND GUSTS TO 30 KNOTS. && .MARINE...HIGH PRESSURE BUILDING NORTH OF THE AREA BRINGS IN EASTERLY SURGE TODAY. GRAYS REEF HAS HAD EASTERLY WINDS SUSTAINED 15+ KNOTS WITH 5 FOOT SEAS MOST OF THE NIGHT. WINDS HAVE SHIFTED TO NW AND BEGINNING TO INCREASE AT ST AUGUSTINE BUOY. HAVE GONE WITH AN EXERCISE CAUTION FOR THE OFFSHORE WATERS. THE INCREASED ONSHORE FLOW AND SEAS WILL ELEVATE THE RISK OF RIP CURRENTS BOTH TODAY AND MONDAY. AS THE HIGH TO THE NORTH RETREATS TO THE EAST AND THE ATLANTIC RIDGE BEGINS TO BUILD BACK OVER FLORIDA AGAIN NEXT WEEK...WILL SEE WINDS/SEAS DECREASE SOMEWHAT AND VEER TO THE SOUTH. && .PRELIMINARY POINT TEMPS/POPS... AMG 89 66 91 67 / 30 10 10 0 SSI 85 73 85 75 / 20 10 10 0 JAX 87 68 88 70 / 30 10 20 10 SGJ 84 73 84 73 / 40 20 20 20 GNV 86 68 88 69 / 50 20 30 20 OCF 86 69 88 70 / 70 30 50 30 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ CARROLL/PETERSON fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TOPEKA KS 806 PM CDT MON JUL 23 2007 .DISCUSSION... HAVE UPDATED THE FORECAST TO REMOVE PRECIP CHANCES FROM THIS EVENING. 00Z WATER VAPOR IMAGERY SHOWS THE UPPER WAVE THAT PRODUCED CONVECTION EARLIER TODAY CONTINUING TO MOVE SOUTHWEST. SUBSIDENCE FROM THE UPPER WAVE HAS CLEARED OUT THE CLOUDS AS WELL AS ANY CHANCE FOR PRECIP. 18Z NAM AND 21Z RUC SHOW LITTLE IN THE WAY OF FORCING FOR NEW DEVELOPMENT BEHIND THE UPPER WAVE. THERE IS STILL A CONCERN FOR SOME PATCHY FOG WITH MODELS SHOWING THE LOW LEVEL MOISTURE AXIS REMAINING OVER EASTERN KS. NOT SURE LOW LEVEL CLOUDS SUGGESTED BY MODEL RH PROGS WILL DEVELOP SINCE THERE IS NOT VERY MUCH ISENTROPIC LIFT FORECAST. THINKING THE MODELS MAY BE OVERDOING IT...HAVE ADJUSTED CLOUD COVER DOWN TONIGHT. && WOLTERS .PREV DISCUSSION /342 PM CDT MON/... MAJORITY OF TIME DEDICATED TO SHORT TERM FLOODING ISSUES SO DISCUSSION WILL BE BRIEF. SHORTWAVE TROUGH AND ASSOCIATED UPPER LEVEL JET WILL CONTINUE DIVING SOUTHWESTWARD ACROSS THE REGION. WATER VAPOR IMAGERY SHOWS DRIER AIR ALOFT AND SUBSIDENCE MOVING IN BEHIND AFOREMENTIONED FEATURES. COULD STILL SEE ISOLATED SHOWERS/THUNDERSTORMS WITHIN THE NEXT FEW HOURS...BUT CHANCES WILL BE DECREASING AS THE EVENING PROGRESSES. BY TONIGHT...MOST AREAS SHOULD REMAIN DRY AND WINDS DECOUPLE WITH POTENTIAL FOR PATCHY FOG TO DEVELOP ACROSS EASTERN HALF OF THE CWA...ESPECIALLY IN AREAS WHICH RECEIVED RAINFALL TODAY. SLIGHT CHANCE OF THUNDERSTORMS OVER CENTRAL CWA TOMORROW WITH GREATEST THREAT DURING PEAK HEATING AS UPPER LEVEL JET DEPARTS REGION. MADE MINOR CHANGES TO OTHER WEATHER ELEMENTS WITHIN SHORT TERM PACKAGE. TUESDAY NIGHT THROUGH THURSDAY...IN GENERAL A SLIGHT RETROGRADING PATTERN SETS UP DURING THIS PERIOD IN THE UPPER AIR PATTERN WITH UPPER LEVEL RIDGE OVER THE NORTHERN PLAINS SHIFTING WEST INTO THE NORTHERN HIGH PLAINS WHILE UPPER LOW PUSHES WEST OVER THE CENTRAL GREAT LAKES REGION. CURRENT SHORTWAVE OVER THE NORTHEASTERN CWA WILL BRING SLIGHTLY DRIER AIR INTO NORTHEASTERN KS...HOWEVER PERSISTENT SOUTHERLY FLOW THROUGH THE PERIOD WILL LIKELY KEEP UPPER 60S TO LOW 70S DEWPOINTS IN THE LOWER LEVELS OF THE ATMOSPHERE. AS THIS RETROGRADING PATTERN DEVELOPS GFS/NAM/EUROPEAN ALL INDICATE A WEAK PIECE OF ENERGY MOVING VERY SLOWLY SOUTHWEST OUT OF THE WESTERN GREAT LAKES. THIS ENERGY LOOKS TO MAKE ITS WAY NEAR THE NORTHEASTERN CWA WEDNESDAY AFTERNOON...HOWEVER MODELS ALSO BRING WARMER AIR IN THE MID LEVELS...IN THEORY KEEPING EASTERN KS CAPPED...ASSUMING UPPER 60S DEW POINTS. BECAUSE OF THIS AS MENTIONED ABOVE DID NOT MENTION WX AT THIS TIME BUT COULD BE AN ISSUE IF MOISTURE RETURN IS STRONGER THAN FORECAST. ON THURSDAY MODELS BRING SHORT LIVED UPPER LEVEL RIDGING OVER THE FORECAST AREA AHEAD OF A STRONGER SHORTWAVE RIDING ALONG THE RIDGE AXIS IN THE NORTHERN PLAINS. BECAUSE OF THIS SHORT RIDGE AMPLIFICATION THURSDAY HAVE LEFT THE FORECAST DRY. FRIDAY THROUGH SATURDAY...THE RELATIVELY STRONG UPPER LEVEL SHORTWAVE MOVING SOUTHEAST THROUGH THE NORTHERN PLAINS LOOKS TO BRING A COLD FRONT THROUGH THE FORECAST AREA LATE FRIDAY AFTERNOON THROUGH THE OVERNIGHT HOURS. WITH EUROPEAN A BIT SLOWER...AND BOTH EUROPEAN AND GFS TAKING THE BEST UPPER LEVEL ENERGY EAST HAVE PLACED BEST CHANCE POPS ACROSS THE EASTERN HALF OF THE CWA FRIDAY NIGHT. THUNDERSTORMS LOOK POSSIBLE ALONG THE FRONTAL BOUNDARY ACROSS THE NORTHERN CWA FRIDAY AFTERNOON...AND THUNDERSTORM CHANCES COULD LINGER IN THROUGH THE DAY ON SATURDAY AS THE UPPER LEVEL ENERGY MOVES EAST OF THE CWA POSSIBLY STALLING OUT THE FRONTAL BOUNDARY ACROSS NORTHEAST KS. CHANCE OF PRECIPITATION WILL LIKELY INCREASE AS DETAILS ON THE TIMING OF THE FRONT AND THE POSITION OF THE BEST UPPER LEVEL LIFT ARE BETTER RESOLVED BY SHORT RANGE MODELS. SATURDAY NIGHT THROUGH MONDAY...IN THE WAKE OF THIS STRONG SHORTWAVE THE 23/12Z GFS INDICATES A STRONG AREA OF SUBSIDENCE OVER EASTERN KS THROUGH MONDAY MORNING. A COMPLICATING FACTOR HERE IS THAT THE LARGE UPPER RIDGE CONTINUES TO RETROGRADE WEST BRINGING NORTHWEST FLOW THROUGH THE CENTRAL PLAINS DURING THE OUTER PERIODS OF THE FORECAST. NORTHWEST FLOW IS NOTORIOUS FOR BRINGING CONVECTIVE EPISODES THROUGH THE CENTRAL PLAINS DURING THE SUMMER MONTHS...SO THIS GENERAL PATTERN CHANGE IS WORTH NOTING. AT THIS TIME WITH LARGE SCALE SUBSIDENCE THE ONLY OBVIOUS FEATURE OVER THE CWA DURING THE PERIOD HAVE LEFT THE FORECAST DRY. WOULD NOT BE SURPRISED HOWEVER FOR THIS TO CHANGE IF A SHORTWAVE EVENTUALLY MOVES THROUGH THE NORTHWEST FLOW ALOFT. THE LONG RANGE MODELS DO NOT INDICATE SHORTWAVE PASSAGE AT THIS TIME...BUT SHORTWAVES ARE TYPICALLY TOO SMALL TO RESOLVE 5 TO 7 DAYS OUT IN THE FORECAST PERIOD. SO AGAIN...NORTHWEST FLOW CLIMATOLOGY WOULD WARRANT PAYING CLOSE ATTENTION TO SMALLER SCALE FEATURES AS THIS PERIOD APPROACHES. && BLAIR/CAVANAUGH .AVIATION... ONLY CONCERN WILL BE WHETHER MVFR VSBY AND CIGS DEVELOP BETWEEN 08Z AND 13Z. LATEST RUC AND NAM SOUNDINGS INSIST ON CLOUDS FORMING AROUND 2 KFT. HOWEVER THERE IS LITTLE ISENTROPIC LIFT FOR THIS TO OCCUR. WITH MODELS STILL SHOWING LOW LEVEL MOISTURE AXIS ACROSS THE REGION...LEFT A TEMPO FOR 3-5SM AND CIGS AROUND BKN025. OTHERWISE EXPECT DIURNAL CU FIELD FOR TUESDAY AFTERNOON. POTENTIAL FOR CONVECTION APPEARS TO ISOLATED TO MENTION IN TAF SITES ATTM. && WOLTERS .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TOPEKA KS 356 AM CDT SUN JUL 22 2007 .DISCUSSION... THE LATEST WATER VAPOR SATELLITE IMAGERY ALONG WITH THE 00Z UPPER AIR MAPS SHOWED A BROAD UPPER RIDGE ACROSS THE GREAT BASIN EXTENDING EASTWARD ACROSS THE CENTRAL PLAINS...THEN EXTENDING NORTHEAST INTO THE MIDWEST AND SOUTH CENTRAL CANADA. AN UPPER LEVEL TROUGH WAS LOCATED ACROSS THE PACIFIC NORTHWEST AND ACROSS THE EASTERN CONUS. AT THE SURFACE A WEAK FRONT EXTENDED FROM THE CENTRAL GULF COAST NORTHWEST INTO EXTREME SOUTHEAST KS. THE SFC BOUNDARY WAS MORE DIFFUSE AS IT EXTENDED NORTHWARD ACROSS EASTERN KS AND NE. THE RUC AND NAM BOTH SHOWED WEAK ISENTROPIC LIFT ON THE 310 DEG K ISENTROPIC SURFACE ACROSS THE WESTERN COUNTIES THROUGH THE MID MORNING HOURS...AND ANOTHER AREA OF ISENTROPIC LIFT ACROSS EXTREME NORTHEAST KS AND NORTHWEST MO. I CANNOT RULE OUT SOME ISOLATED SHOWERS DEVELOPING ACROSS THE WESTERN CWA AND BROWN COUNTY BY SUNRISE AND THROUGH THE MID MORNING HOURS. I MAY ONLY PLACE IN 14 POPS THIS MORNING THOUGH. TODAY THROUGH SUNDAY NIGHT...BOTH THE NAM AND GFS SHOW THE UPPER RIDGE REMAINING ACROSS THE SOUTHERN HIGH PLAINS...NORTHEAST INTO THE CENTRAL PLAINS. DURING THE AFTERNOON HOURS SURFACE HEATING WILL CAUSE CONVECTIVE TEMPERATURES TO BE REACHED. FORECAST SOUNDING SHOW LITTLE IN THE WAY OF A CAP...THUS ANY WEAK CONVERGENCE ACROSS THE CWA WILL CAUSE ISOLATED THUNDERSTORMS TO DEVELOP THIS AFTERNOON AND EARLY EVENING. IT IS DIFFICULT TO FORECAST WHERE MESOSCALE CONVERGENCE MAY OCCUR THEREFORE I KEPT A SLIGHT CHANCE OF POPS ACROSS THE ENTIRE CWA. SYNOPTIC SCALE SUBSIDENCE NEAR THE 5H RIDGE AXIS SHOULD KEEP ISOLATED COVERAGE OF THUNDERSTORMS. ONCE AGAIN ANY THUNDERSTORM THAT DOES DEVELOP WILL PRODUCE HEAVY RAINFALL. DUE TO THE WEAK MID AND UPPER FLOW THESE ISOLATED STORMS MAY REMAIN NEARLY STATIONARY AND COULD CAUSE FLOODING OF LOW-LYING AREAS. HIGHS TODAY SHOULD REACH THE MID 90S ACROSS THE WESTERN COUNTIES WITH AROUND 90 ACROSS THE EASTERN COUNTIES. MONDAY AND MONDAY NIGHT...BOTH THE NAM AND GFS SHOW A JET MAX AND A MINOR 5H TROUGH ROTATING AROUND THE 5H RIDGE AXIS AND MOVING SOUTHWEST FROM WESTERN WI ACROSS IA AND INTO NORTHEAST KS DURING THE PERIOD. THE NAM IS FASTER AND TRACKS THE 5H TROUGH FARTHER WEST THAN THE GFS. I`M LEANING A BIT MORE TOWARDS THE NAM...THUS I INCREASED POPS FOR THE ENTIRE CWA FOR MONDAY AFTERNOON. THE LIFT AHEAD OF THE 5H TROUGH WILL CAUSE THE COVERAGE OF THUNDERSTORMS TO INCREASE ACROSS THE CWA BY MONDAY AFTERNOON AND THROUGH THE EVENING HOURS. THE STORMS WILL MOVE SOUTH-SOUTHWEST AND MAY BE MORE ORGANIZED DUE TO THE MID LEVEL WINDS INCREASING TO AROUND 40 KTS BY MONDAY AFTERNOON. THE STORMS MAY PRODUCE SMALL HAIL...STRONG OUTFLOW WINDS AND HEAVY RAINFALL. I KEPT CHANCE POPS IN THROUGH MONDAY NIGHT DUE TO THE SLOWER GFS SOLUTION WHICH BRINGS IN THE BEST CHANCE OF RAIN MONDAY EVENING INTO THE EARLY MORNING HOURS OF TUESDAY. HIGHS ON MONDAY WILL BE SLIGHTLY COOLER WITH ADVECTION AND LIFT COOLING THE VERTICAL COLUMN OF THE ATMOSPHERE UP TO 500MB. HIGHS ACROSS THE EASTERN COUNTIES WILL BE IN THE UPPER 80S WITH LOWER 90S ACROSS THE WESTERN COUNTIES. TUESDAY AND TUESDAY NIGHT...BOTH THE NAM AND GFS CONTINUE TO MOVE MINOR DISTURBANCES SOUTHWEST AROUND THE NEARLY STATIONARY RIDGE AXIS ACROSS THE THE SOUTHERN HIGH PLAINS AND CENTRAL PLAINS. GIVEN AN ATMOSPHERE OF DEEP MOISTURE...INSTABILITY AND LIFT THERE WILL BE AT LEAST A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS TUESDAY AFTERNOON AND EVENING. HIGHS MAY BE A DEGREE OR TWO WARMER THAN MONDAY`S HIGHS...WITH NEAR 90 ACROSS THE EASTERN COUNTIES AND MID 90S ACROSS THE WESTERN COUNTIES. WEDNESDAY THROUGH FRIDAY...THE ECMWF MODEL EXPANDS THE 5H RIDGE A BIT FARTHER EAST. THIS WOULD CAUSE HIGH TEMPERATES TO WARM INTO THE LOWER TO MID 90S. ONCE AGAIN THERE MAY BE ADEQUATE DEEP MOISTURE AND ENOUGH SFC CONVERGENCE FOR ISOLATED THUNDERSTORMS DURING THE AFTERNOON AND EVENING HOURS. FRIDAY NIGHT AND SATURDAY...BOTH THE GFS AND ECMWF FORECAST THE UPPER RIDGE TO RETROGRADE WESTWARD ACROSS THE SOUTHERN AND CENTRAL ROCKIES. THIS MAY ALLOW FOR MINOR 5H TROUGHS TO DIG SOUTHEAST AROUND THE 5H RIDGE AXIS ACROSS THE MIDWEST AND MS RIVER VALLEY. THERE MAY BE ENOUGH LIFT AHEAD OF THESE MINOR DISTURBANCES FOR A SLIGHT CHANCE OF THUNDERSTORMS ON SATURDAY. IF THE 5H TROUGHS DIG FARTHER WEST THE RAIN CHANCES WOULD INCREASE. ATTM THE EXTENDED FORECAST GRIDS LOOKED GOOD AND NO CHANGES WERE MADE. 66 && .AVIATION... AVIATION CONCERNS ARE DEVELOPMENT OF LOW CLOUDS IN MOISTURE RICH LOW LEVELS AS WARM ADVECTION/ISENTROPIC LIFT OCCURS OVER DISSIPATING SURFACE BOUNDARY. RUC/NAM ISENTROPIC LIFT ON THE 305-310 THETA SURFACES SHOW EASTERN PORTIONS CWA...KTOP/KFOE TAFS SHOULD BEGIN TO SEE SOME DEVELOPMENT SHORTLY. LATEST 11-3.9U SATELLITE IMAGERY SHOWING A FEW SPOTS OF LOW CLOUDS BUT NOT AS WIDESPREAD AS MODELS WOULD HAVE. PLAN FOR NOW IS TO GO WITH CURRENT FORECAST OF VFR CIGS AROUND 3500FT AT 12Z...GIVEN YESTERDAY`S TREND MAY INCLUDE A SCT DECK AROUND 1200-1500FT THROUGH 15Z. CONDENSATION PRESSURE DEFICITS NOT AS CONDUCIVE FOR CLOUDS IN KMHK SITE AND WILL KEEP SCATTERED CLOUDS THERE...HOWEVER WITH TWO DAYS OF SIGNIFICANT RAINFALL IN AND AROUND TAF SITE...LIGHT WINDS AT START OF DAY...MAY ADD A TEMPO GROUND TIL 14Z OF 4 MILES IN BR. FOG PLOT SAYING MIXY BUT ALSO HAS DEWPOINT LOWER THAN CURRENT READINGS. WAA AND ISENTROPIC LIFT WOULD ALSO HINT OF AT LEAST ISOLD -SHRA CHANCES THIS AM MAINLY OVER EASTERN PTNS OF CWA...WHICH WILL LIKELY HAVE TO WAIT TIL ISSUANCE TIME IF THAT NEEDS TO BE ADDED TO TAFS. OTHERWISE...WILL GO WITH PERSISTENCE AND LEAN TOWARD CURRENT FORECAST WITH SCT CU AT 4-5K FT THIS AFTERNOON UNTIL AROUND 02Z...AND ADD CB TO CLOUDS AT THIS POINT GIVEN AFTERNOON INSTABILITY...JUST NOT SURE WHERE CONVERGENCE WILL BE MOST FOCUSED. CLOUDS SHOULD THIN BY SUNSET BUT APPROACHING SHORTWAVE SHOULD SPREAD SOME MID CLOUDS BACK INTO PICTURE BY LATE TONIGHT. LIGHT SOUTHEAST WINDS UNTIL MIXING THIS MORNING BUT EVEN THEN MODELS SHOWING GENERALLY ONLY 8 TO 15KTS OF S TO SE WINDS. PF && .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ 66/PF ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 958 PM EDT MON JUL 23 2007 .SYNOPSIS... AN AREA OF UPPER LEVEL LOW PRESSURE WILL REMAIN NORTH AND WEST OF THE REGION OVERNIGHT...AS WEAK HIGH PRESSURE BECOMES ESTABLISHED OFF THE SOUTHEAST AND MID ATLANTIC COAST FOR THE REMAINDER OF THE WEEK. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... UPR LOW HAS MOVED FURTHER NORTHWARD THIS EVENING...AND WL CONT TO SLOWLY DRIFT NW OVERNIGHT...REMAINING NEARLY STATIONARY OVER W PA/OH. SKY COVERAGE HAS WANED CONSIDERABLY OVER THE COURSE OF THE EVENING. LINGERING CLOUDINESS OVERNIGHT ON THE BACKSIDE OF THE DEPARTED UPR LOW WL BE WELL WEST OF THE REGION INTO THE MTNS...WITH CLDS IN THE AKQ CWFA LKLY LIMITED TO WISPS OF CI ACRS PIEDMONT AND CENTRAL VA OVERNIGHT...WITH GENLY CLR SKIES TO BE NOTED ELSEWHERE. DID TRIM FOG MENTION BACK...KEEPING FOG OVER MD EASTERN SHORE COUNTIES AFTER 06Z OVERNIGHT INTO ERY TUE. GENLY EXPECTING LTL/NO WND OVERNIGHT...EXACERBATING CONCERNS FOR BR ACROSS RGN (STILL CANNOT RULE OUT SOME ISO BR ACRS PIEDMONT/CENTRAL VA). RECORD LOW TEMP FOR THE DATE (7/25) IS 53 DEGREES IN SBY. LATEST GUIDANCE TRENDING LOWS DOWNWARD (18Z/JUL24 MAV, 54....12Z/JUL24 MET...55). LATEST RUC DATA AND (DRYING) FORECAST SOUNDINGS GIVE NO REASON TO BELIEVE A CHANGE IS NEEDED TO GOING FORECAST. THINKING THAT WE SHUD BE (AT THE VRY LEAST) CLOSE TO THAT 53 NUMBER AT SBY TNGT...WITH DRYING/STABILIZING AIRMASS OVERHEAD AND HV TRENDED TEMPS DOWNWARD ACROSS EASTERN SHORE COUNTIES TO REFLECT THIS TREND. WENT WITH LOWS IN THE U50S/L60S ACROSS THE REMAINDER OF THE AREA. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/... SKIES WILL CLR OUT TONIGHT BEFORE AN INCREASE IN HIGH LVL DEBRIS CLOUDS TWRDS AM OVER FAR W. MAINLY SUNNY/MO SUNNY THROUGH MID AM BEFORE CU WILL ONCE AGAIN DVLP TWRDS AFTN HRS OVER THE REGION. GUIDANCE DID POORLY (ARIEL COVERAGE) SEEING PRECIP DVLPMNT AROUND THE UPR LVL LOW FOR THIS AFTN...SO WILL KEEP POPS IN FOR TMRW (ESPECIALLY WITH ANY SEABREEZE ACTIVITY). && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... BEYOND THAT NOT MUCH CHANGE TO FCST...UPR LVL LOW WILL CONTINUE TO BE SITUATED OVER THE OH VLY/WRN MID ATL RGN INTO LATE WK (AS IT WEAKENS) AS HIGH PRESSURE REMAINS OFFSHORE. THIS LOW WILL ALLOW FOR THE PINWHEEL EFFECT TO CONTINUE...WHICH WILL ALLOW PIECES OF ENERGY (VORT MAXS) TO SPIN AROUND AND OFF OF IT. A TROPICAL CONNECTION WILL CONTINUE AND INCREASE DURING THE WEEK BETWEEN THE UPR LVL LOW AND THE HIGH OFFSHORE ALLOWING FOR GULF COAST MOISTURE TO BE FEED INTO THE MID ATL RGN FROM THE SOUTH. OVERALL...LOOK FOR THE CHC OF SHRA/TSTM TO DEVELOP ON A DAILY BASIS...ESPECIALLY AFTN/EVE (BUT NOT LIMITED TOO). OVERALL CLOUD COVER AND PRECIP COVERAGE MAY IMPINGE ON MAX/MIN TEMPS AT TIMES IN PORTIONS OF THE CWA THROUGH THE COURSE OF THE WEEK. && .AVIATION /01Z TUESDAY THROUGH SATURDAY/... GENLY VFR NEXT SVRL DAYS. COULD BE SOME ISOLD BR AT KSBY...BUT LOW DEWPTS ARGUE AGAINST IT. UPR LOW JUST WEST OF AREA WILL PROVIDE OPPORTUNITIES FOR SHWRS/TSTMS ESPECIALLY FROM MIDWEEK ON. THESE WILL BRING MVFR/PSBL IFR CIGS/VSBYS. BUT THESE CONDITIONS EXPECTED TO BE INTERMITTENT AND BRIEF. COULD SEE SOME NOCTURNAL FOG PROBLEMS LATE IN WEEK AS DEWPTS RISE AND MORE AREAS RECEIVE RAINFALL. && .MARINE... HAVE CANCELED REMAINDER OF THE SCA ON THE COASTAL WATERS AS SEAS HAVE DROPPED BELOW 5 FT ALL AREAS. MADE SOME TWEAKS TO WINDS TNGT AND ERY TUE BASED UPON CURRENT OBSERVATIONS AND LATEST NAM12. PORTIONS OF PREVIOUS DISCUSSION...SHOWERS AND THUNDERSTORMS WILL CONTINUE TO BE POSSIBLE OVER THE WATERS THROUGH THE END OF THE WEEK AS THE UPR LOW REMAINS JUST NW OF THE AREA...BUT WINDS SHOULD REMAIN 15KTS OR LESS THROUGH SATURDAY. && .EQUIPMENT... KDOX REMAINS DOWN...AS THEY WAIT FOR THE ARRIVAL OF A SPARE PART. PART DID NOT ARRIVE TODAY AS ORIGINALLY ANTICIPATED...AND CURRENTLY DO NOT HV ESTIMATE ATTM WHEN PART WILL ARRIVE. WILL PROVIDE ADDITIONAL INFO WHEN WE RECEIVE IT. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...CCW/MAM NEAR TERM...CCW/MAM SHORT TERM...CCW LONG TERM...CCW AVIATION...WRS MARINE...JYM/WRS EQUIPMENT...NWS/AKQ md AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 718 AM EDT MON JUL 23 2007 .SYNOPSIS... LOW PRESSURE WILL STRENGTHEN OFF THE VIRGINIA...MARYLAND COAST TODAY. THE LOW WILL MOVE OFF TO THE NORTH OF THE REGION TONIGHT...AS WEAK HIGH PRESSURE BECOMES ESTABLISHED OFF THE SOUTHEAST AND MID ATLANTIC COAST FOR THE REMAINDER OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATED ZONES TO TWEAK TWDS LATEST TRENDS/OBS...ISO SHWR MAKING IT THRU ZONES N OF RICHMOND AND TSTM OVER CNTRL NC RIGHT NOW W/ THE UPR LOW/VORT MAX. RUC SHOWS THIS VORT MAX TRACKING THRU ERN/CNTRL VA LATE THIS MRNG/ERLY AFTN SO HAVE BROUGHT POPS A BIT FARTHER SOUTHWARD THIS AFTN...AND HAVE ADDED THUNDER INTO VA ERN SHORE CNTYS WITH RUC SHOWING A BIT MORE INSTABILITY. OTHERWISE COASTAL LOW CURRENTLY LOCATED ABOUT 100 MILES EAST OF NORFOLK/VA BCH...PROVIDING BREEZY NLY FLOW ALONG THE COAST. MAIN PRECIP BAND IS ALIGNED SSE TO NNW...FROM SRN NJ/DEL/MD COASTAL AREAS SSE OFFSHORE. NAM INITIALIZING BETTER W/ CURRENT PRECIP SETUP THAN GFS...SO HAVE FOLLOWED CLOSER TO THE NAM FOR POPS TODAY. WENT LIKELY ALONG MD/VA ERN SHORE ZONES. FARTHER SW A FEW ISO SHWRS ARE SEEN ON RADAR ASSOCIATED WITH THE UPPER LOW WHICH IS CENTERED OVER CNTRL NC. ASIDE FROM THE ERN SHORE...MET/MAV GDNC IS VERY LOW WITH PRECIP CHC LATER THIS AFTN. HAVE HOWEVER KEPT AT LEAST 20% CHC IN FOR BULK OF THE CWA THIS AFTN...WITH INFLUENCE OF THE UPPER LOW. LOW LEVEL INSTABILITY WILL BE LMTD DUE TO NLY FLOW...BUT IN VA ZONES (CLOSER TO THE EVENTUAL POSITION OF THE UPPER LOW THIS AFTN) HAVE THUNDER MENTIONED WITH THE ENHANCED MID LVL LAPSE RATES/COLD POOL ALOFT. SEVERE THREAT LOOKS LMTD...BUT FRZ LEVELS RELATIVELY LOW SO WOULD NOT BE SURPRISED TO SEE HAIL IF ANYTHING GETS ORGANIZED. HIGHS TODAY...DEPENDING ON AMT OF CLOUD CVR WILL BE WELL BELOW NORMAL...LWR/MID 80S SW ZONES...ONLY IN THE 70S ON THE COAST AND IN MD (SEE CLIMATE SECTION). && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... RETAIN SCHC PRECIP THROUGH 01Z IN THE EVENG...OTHERWISE SKIES BECOME PTLY CLOUDY TO MCLR OVERNIGHT. TEMPS DROP FAIRLY SIGNIFICANTLY AND WITH SOMEWHAT MORE MSTR AROUND THAN PREV NGTS EXPECT AT LEAST PTCHY FOG DEVELOPMNT INLAND. TUE LOOKS RELATIVELY DRY FROM THE GUIDANCE PERSPECTIVE (KEEPING CONVECTION MAINLY WEST OF THE CWA)...BUT KEPT 20% CHC IN THE FCST FOR THE AFTN/EVENG WITH UPR LVL LOW BEING IN CLOSE PROXIMITY AROUND THE REGION. KEEPING 30% POPS IN OVER FAR WRN PIEDMNT. TEMPS REBOUND CLOSER TO NORMAL ALTHOUGH STILL A TAD BELOW...WITH HIGHS IN MID/UPR 80S. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... BEYOND THAT...UPR LVL LOW WILL CONTINUE TO BE SITUATED OVER THE OH VLY/WRN MID ATL RGN INTO THE BEGINING OF THE WEEKND (AS IT WEAKENS) AND HIGH PRESSURE REMAINS OFFSHORE. THIS LOW WILL ALLOW FOR THE PINWHEEL EFFECT TO CONTINUE...WHICH WILL ALLOW PIECES OF ENERGY (VORT MAXS) TO SPIN OFF AROUND AND OFF OF IT. A TROPICAL CONNECTION WILL EXIST BETWEEN THE UPR LVL LOW AND THE HIGH OFFSHORE ALLOWING FOR GULF COAST MOISTURE TO BE FEED INTO THE MID ATL RGN FROM THE SOUTH. OVERALL...LOOK FOR THE CHC OF SHRA/TSTM TO DEVELOP ON A DAILY BASIS...MAINLY ESPECIALLY AFTN/EVENG. KEEPING POPS IN 305 RANGE WED...THEN WITH INCRSG MSTR THU/FRI HAVE 40% POPS DURING AFTN/EVENG. MEX GDNC/GFS H8 TEMPS ARE COMING IN WARMER WITH LATEST RUNS...BUT THE ECMWF IS A LITTLE COOLER. OVERALL COOL AIR ALOFT ON PERIPHERY OF THE UPPER LOW WILL LEAD TO AT LEAST PTLY CLDY SKIES QUICKLY AS THE CONVECTIVE TEMPS ARE EASILY REACHED. THIS WILL TEND TO HOLD TEMPS DOWN SOMEWHAT SO HAVE KEPT TEMPS 1-3 DEGREES BELOW GDNC (ALTHOUGH RAISED THEM A DEGREE OR TWO FROM PREV FCST). && .AVIATION /11Z MONDAY THROUGH FRIDAY/... GENLY VFR NEXT SVRL DAYS. CSTL LCTNS (ESP SBY) MAY HV BRIEF PDS OF MVFR IN LWR CIGS/SCTD PCPN TDA (MNLY THIS MRNG) DUE TO CSTL LO PRES MVG SLOLY NWD. && .MARINE... UPR LVL LO PRES OVR INLAND MDATLC RGN CONTS TO GRDLY SPIN UP SFC LO OFFSHR. THAT LO MVS GRDLY NWD TO NR NJ CST THIS EVE. FOR JULY...DECENT LLVL WND SPDS FM THE NNE ON THE WTRS...GENLY AVGG 20 TO 25 KT...B4 WKNG AND BCMG MR SSELY FOR MID/LT WK. SCAS RMNG UP THROUGH THIS AFTN ALL AREAS...THROUGH EVE ON THE OCN WTRS. WAVE WATCH BUILDS KPS SEAS AOA 5 FT THROUGH EVE ON THE OCN...THEN LWRG...WL FOLLOW TRENDS/GUID. && .CLIMATE... HIGH TEMPERATURES TODAY WILL BE WELL BELOW NORMAL FOR LATE JULY...ESPECIALLY ON THE MARYLAND ERN SHORE. SBY HAS A DECENT SHOT AT BREAKING THE RECORD LOW MAX TEMP FOR TODAY. (77 F SET IN 1997). && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR NCZ102. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ650- 652-654-656-658. SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS AFTERNOON FOR ANZ630>632. SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ633. && $$ SYNOPSIS...BROWN NEAR TERM...BROWN SHORT TERM...BROWN LONG TERM...CCW/BROWN AVIATION...25 MARINE...25 CLIMATE...BROWN md AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 1250 PM EDT MON JUL 23 2007 .UPDATE... CONCERNS FOCUS ON CHCS OF SHRA THIS AFTERNOON AND COVERAGE. LATEST WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WEAK SHORTWAVE MOVING DOWN OVER HIGH PLAINS RIDGE AND INTO THE UPR GREAT LAKES. HOWEVER...UPSTREAM 12Z SOUNDING AT KINL ALONG PATH OF SHORTWAVE SHOW VERY DRY AIR AT MID-LVLS AND THIS AIR IS PROJECTED BY MODELS TO ADVECT INTO WRN COUNTIES THIS AFTERNOON. MODIFIED RUC SNDGS AT KIWD AND KCMX SHOW EVIDENCE OF THIS DRY AIR MOVING IN THIS AFTERNOON. SOUNDINGS OVER WRN COUNTIES SHOW THIS DRIER AND WARMER AIR PROVIDING ENOUGH OF A CAP (100-200 J/KG OF CIN) WHICH WOULD PREVENT SHRA INITIATION. THUS...HAVE REMOVED SHRA FOR WRN COUNTIES FOR THIS AFTERNOON AND TONIGHT. FCST SNDGS NOT SHOWING AS STRONG OF A CAP OVER CENTRAL COUNTIES SO CONVERGENCE ALONG ANY LAKE BREEZE BOUNDARY COULD INITIATE CONVECTION THIS AFTERNOON WITH 400-500 J/KG CAPE INDICATED. THUS...WILL MAINTAIN GOING LOW CHC POPS OVER CENTRAL AND ERN COUNTIES THIS AFTERNOON. BUMPED UP TEMPS SLIGHTLY BASED ON EXPECTED MIXING TO NEAR 850 MB. PERSISTENT CLOUD COVER NOTED ON VISIBLE SATELLITE MAY LIMIT MIXING FOR SOME LOCATIONS. && .PREV DISCUSSION (ISSUED AT 417 AM EDT)... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE POTENTIAL THUNDERSTORMS TODAY AND TUESDAY. WATER VAPOR AND RUC/NAM SHOWING A CLOSED LOW OVER CENTRAL MID ATLANTIC STATES...A BROAD RIDGE BLANKETS MUCH OF THE WESTERN CONUS. THE RIDGE STRETCHES FROM THE NORTHERN PLAINS ACROSS THE FORECAST AREA INTO SOUTHERN QUEBEC AS WELL. WEAK SHORTWAVE PASSING THROUGH THE AREA TRIGGERED A FEW SHOWERS AND THUNDERSTORMS OVER THE AREA LAST EVENING. ANOTHER SHORTWAVE IS OVER NORTHEAST MINNESOTA AND CENTRAL ONTARIO. SURFACE ANALYSIS DEPICTS A RIDGE OVER THE LOWER GREAT LAKES EXTENDING INTO NORTHERN NEW ENGLAND. A LOW IS OVER MINNESOTA WITH A STATIONARY FRONT EXTENDING NORTHEAST INTO EASTERN HUDSON BAY...AND SOUTH OF THE LOW THROUGH THE CENTRAL PLAINS. ANOTHER LOW IS DEVELOP OVER THE HIGH PLAINS. LOW LEVEL MOISTURE AHEAD OF THE FRONTAL SYSTEM IS FAIRLY DRY AS ANOTHER COLD FRONT DRAPED ACROSS THE SOUTHERN STATES HAVE CUT OFF THE GULF MOISTURE FRONT REACH THE UPPER GREAT LAKES REGION. THE MID LEVEL LOW OVER THE MID ATLANTIC STATES WILL LIFT NORTHWEST THROUGH THE EASTERN OHIO RIVER VALLEY TODAY AND TONIGHT INTO THE LOWER GREAT LAKES WHERE IT WILL SPIN THROUGH TUESDAY. THE NORTHERN PLAINS HIGH WILL SLIDE OVER THE DAKOTAS. THE RIDGE WILL STILL EXTEND EAST ACROSS LAKE SUPERIOR INTO EAST CENTRAL ONTARIO. NAM/GFS DEVELOP MLCAPE VALUES AROUND 1000J/KG OVER THE WESTERN TWO THIRDS TODAY AND >2100J/KG OVER CENTRAL U.P. AROUND 18Z TUESDAY. CANADIAN GEM SHOWERS MEAN RH 65 TO 70 PERCENT OVER THE FORECAST AREA. THUS...WITH SOME DAYTIME HEATING...EXPECT A CHANCE OF SHOWERS AND THUNDERSTORMS OVER THE FORECAST AREA TODAY...MAINLY THE WEST HALF. THE CHANCES SHOULD DIMINISH THIS EVENING AS DAYTIME HEATING FALLS OFF. ON TUESDAY...AVAILABLE MOISTURE WILL STILL BE RATHER LIMITED. HOWEVER...WILL KEEP A SLIGHT CHANCE GOING. THE CLOSED LOW WILL REMAIN OVER LAKE ERIE THROUGH THURSDAY NIGHT. THE RIDGE OVER NORTHERN PLAINS WILL LIKEWISE REMAIN STATIONARY THROUGH WEDNESDAY. WEDNESDAY NIGHT THE RIDGE WILL SHIFT SOUTH INTO THE CENTRAL PLAINS. MEANWHILE...NUMEROUS WEAK SHORTWAVES WILL SWEEP THROUGH THE FORECAST AREA. THE FIRST WILL MOVE THROUGH THE AREA TUESDAY NIGHT FOLLOWED OTHERS THURSDAY AFTERNOON...AND THURSDAY NIGHT. A COLD FRONT WILL SWEEP THROUGH THE FORECAST AREA THURSDAY NIGHT. THE AIR MASS CONTINUES TO BE DRY. HOWEVER...AT THE SURFACE CONDITIONS WILL BE MOIST. A STRONG INVERSION WILL OCCUR AROUND 750MB. GFS/NAM SHOWS THE AIR MASS WILL BE DRY. BY NOON ON TUESDAY...NAM/GFS SHOWING MLCAPE VALUES WILL EXCEED 2K J/KG MAINLY OVER CENTRAL U.P. SURFACE DEW POINTS WILL REMAIN IN THE LOW TO MID 60S ACROSS THE AREA. NIGHTTIME COOLING INTO THE 60S SHOULD LEND ITSELF TO PRODUCING PATCHES OF FOG AROUND THE AREA. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... VFR CLOUD DECK INTERSPERSED WITH AREAS OF HIGH END MVFR CIGS HAS BEEN MOVING/DEVELOPING EASTWARD ACROSS WESTERN UPPER MI EARLY THIS MORNING. UPSTREAM OBS SUGGEST CURRENT MVFR CIGS AT KCMX SHOULD ONLY PERSIST FOR THE NEXT FEW HRS AT MOST. AT KSAW...MVFR CIGS WILL LIKELY MAKE AN APPEARANCE OVER THE NEXT COUPLE OF HRS. BUILDING INSTABILITY THIS AFTN COMBINED WITH DEVELOPING LAKE BREEZE BOUNDARIES SHOULD SET THE STAGE FOR SCT SHRA/TSRA THIS AFTN. AT THIS TIME...IT APPEARS BETTER FOCUS FOR SHRA/TSRA WILL OCCUR OVER THE INTERIOR OF CNTRL UPPER MI. STILL...COVERAGE SHOULD BE LIMITED. HAVE THUS ONLY INCLUDED A PROB GROUP AT KSAW FOR THE LATE AFTN AND DID NOT INCLUDE EXPLICIT MENTION OF THUNDERSTORM. CONDITIONS TONIGHT LOOK FAVORABLE FOR SOME FOG FORMATION...AND HAVE INCLUDED MVFR VSBY AT KSAW/KCMX. MAY SEE VSBY TOUCH IFR LATE. SHOULD IT RAIN AT EITHER SITE TODAY...FOG WILL LIKELY RESTRICT VSBY TO LIFR LATE TONIGHT. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... EXPECT SOME FOG TO BE FOUND ACROSS LAKE SUPERIOR TODAY THUR TUE THOUGH CONFIDENCE ON COVERAGE IS LOW. HAVE NOT SEEN ANY SHIP OBS INDICATING REDUCED VSBY...BUT THERE WERE SCATTERED SHRA OVER THE LAKE EARLIER IN THE NIGHT...SUGGESTING THE POSSIBILITY THAT SOME FOG MAY HAVE DEVELOPED. AFTER SUNRISE...VIS SATELLITE IMAGERY WILL HELP SHED LIGHT ON WHETHER ANY FOG EXISTS. IF THERE IS NONE...FOG WILL LIKELY NOT BE AN ISSUE THROUGH WED. OTHERWISE...WINDS ARE EXPECTED TO REMAIN BELOW 20KT THROUGH FRI WITH ONE EXCEPTION. TROUGH MOVING ACROSS THE NORTHERN PLAINS WILL CAUSE SOUTHERLY WINDS WINDS TO INCREASE WED NIGHT. AS IS TYPICALLY THE CASE...SOUTHERLY WINDS WILL BE STRONGER OVER EASTERN LAKE SUPERIOR. ALTHOUGH WINDS AT BUOY OBSERVATION PLATFORMS WILL REMAIN BLO 20KT...HIGHER OBSERVING PLATFORMS WILL LIKELY SEE SUSTAINED WINDS OR FREQUENT GUSTS TO AROUND 25KT. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE...VOSS AVIATION/MARINE...ROLFSON PREV DISCUSSION...DLG mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 741 AM EDT MON JUL 23 2007 UPDATED FOR AVIATION DISCUSSION .DISCUSSION (ISSUED AT 417 AM EDT)... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE POTENTIAL THUNDERSTORMS TODAY AND TUESDAY. WATER VAPOR AND RUC/NAM SHOWING A CLOSED LOW OVER CENTRAL MID ATLANTIC STATES...A BROAD RIDGE BLANKETS MUCH OF THE WESTERN CONUS. THE RIDGE STRETCHES FROM THE NORTHERN PLAINS ACROSS THE FORECAST AREA INTO SOUTHERN QUEBEC AS WELL. WEAK SHORTWAVE PASSING THROUGH THE AREA TRIGGERED A FEW SHOWERS AND THUNDERSTORMS OVER THE AREA LAST EVENING. ANOTHER SHORTWAVE IS OVER NORTHEAST MINNESOTA AND CENTRAL ONTARIO. SURFACE ANALYSIS DEPICTS A RIDGE OVER THE LOWER GREAT LAKES EXTENDING INTO NORTHERN NEW ENGLAND. A LOW IS OVER MINNESOTA WITH A STATIONARY FRONT EXTENDING NORTHEAST INTO EASTERN HUDSON BAY...AND SOUTH OF THE LOW THROUGH THE CENTRAL PLAINS. ANOTHER LOW IS DEVELOP OVER THE HIGH PLAINS. LOW LEVEL MOISTURE AHEAD OF THE FRONTAL SYSTEM IS FAIRLY DRY AS ANOTHER COLD FRONT DRAPED ACROSS THE SOUTHERN STATES HAVE CUT OFF THE GULF MOISTURE FRONT REACH THE UPPER GREAT LAKES REGION. THE MID LEVEL LOW OVER THE MID ATLANTIC STATES WILL LIFT NORTHWEST THROUGH THE EASTERN OHIO RIVER VALLEY TODAY AND TONIGHT INTO THE LOWER GREAT LAKES WHERE IT WILL SPIN THROUGH TUESDAY. THE NORTHERN PLAINS HIGH WILL SLIDE OVER THE DAKOTAS. THE RIDGE WILL STILL EXTEND EAST ACROSS LAKE SUPERIOR INTO EAST CENTRAL ONTARIO. NAM/GFS DEVELOP MLCAPE VALUES AROUND 1000J/KG OVER THE WESTERN TWO THIRDS TODAY AND >2100J/KG OVER CENTRAL U.P. AROUND 18Z TUESDAY. CANADIAN GEM SHOWERS MEAN RH 65 TO 70 PERCENT OVER THE FORECAST AREA. THUS...WITH SOME DAYTIME HEATING...EXPECT A CHANCE OF SHOWERS AND THUNDERSTORMS OVER THE FORECAST AREA TODAY...MAINLY THE WEST HALF. THE CHANCES SHOULD DIMINISH THIS EVENING AS DAYTIME HEATING FALLS OFF. ON TUESDAY...AVAILABLE MOISTURE WILL STILL BE RATHER LIMITED. HOWEVER...WILL KEEP A SLIGHT CHANCE GOING. THE CLOSED LOW WILL REMAIN OVER LAKE ERIE THROUGH THURSDAY NIGHT. THE RIDGE OVER NORTHERN PLAINS WILL LIKEWISE REMAIN STATIONARY THROUGH WEDNESDAY. WEDNESDAY NIGHT THE RIDGE WILL SHIFT SOUTH INTO THE CENTRAL PLAINS. MEANWHILE...NUMEROUS WEAK SHORTWAVES WILL SWEEP THROUGH THE FORECAST AREA. THE FIRST WILL MOVE THROUGH THE AREA TUESDAY NIGHT FOLLOWED OTHERS THURSDAY AFTERNOON...AND THURSDAY NIGHT. A COLD FRONT WILL SWEEP THROUGH THE FORECAST AREA THURSDAY NIGHT. THE AIR MASS CONTINUES TO BE DRY. HOWEVER...AT THE SURFACE CONDITIONS WILL BE MOIST. A STRONG INVERSION WILL OCCUR AROUND 750MB. GFS/NAM SHOWS THE AIR MASS WILL BE DRY. BY NOON ON TUESDAY...NAM/GFS SHOWING MLCAPE VALUES WILL EXCEED 2K J/KG MAINLY OVER CENTRAL U.P. SURFACE DEW POINTS WILL REMAIN IN THE LOW TO MID 60S ACROSS THE AREA. NIGHTTIME COOLING INTO THE 60S SHOULD LEND ITSELF TO PRODUCING PATCHES OF FOG AROUND THE AREA. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... VFR CLOUD DECK INTERSPERSED WITH AREAS OF HIGH END MVFR CIGS HAS BEEN MOVING/DEVELOPING EASTWARD ACROSS WESTERN UPPER MI EARLY THIS MORNING. UPSTREAM OBS SUGGEST CURRENT MVFR CIGS AT KCMX SHOULD ONLY PERSIST FOR THE NEXT FEW HRS AT MOST. AT KSAW...MVFR CIGS WILL LIKELY MAKE AN APPEARANCE OVER THE NEXT COUPLE OF HRS. BUILDING INSTABILITY THIS AFTN COMBINED WITH DEVELOPING LAKE BREEZE BOUNDARIES SHOULD SET THE STAGE FOR SCT SHRA/TSRA THIS AFTN. AT THIS TIME...IT APPEARS BETTER FOCUS FOR SHRA/TSRA WILL OCCUR OVER THE INTERIOR OF CNTRL UPPER MI. STILL...COVERAGE SHOULD BE LIMITED. HAVE THUS ONLY INCLUDED A PROB GROUP AT KSAW FOR THE LATE AFTN AND DID NOT INCLUDE EXPLICIT MENTION OF THUNDERSTORM. CONDITIONS TONIGHT LOOK FAVORABLE FOR SOME FOG FORMATION...AND HAVE INCLUDED MVFR VSBY AT KSAW/KCMX. MAY SEE VSBY TOUCH IFR LATE. SHOULD IT RAIN AT EITHER SITE TODAY...FOG WILL LIKELY RESTRICT VSBY TO LIFR LATE TONIGHT. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... EXPECT SOME FOG TO BE FOUND ACROSS LAKE SUPERIOR TODAY THUR TUE THOUGH CONFIDENCE ON COVERAGE IS LOW. HAVE NOT SEEN ANY SHIP OBS INDICATING REDUCED VSBY...BUT THERE WERE SCATTERED SHRA OVER THE LAKE EARLIER IN THE NIGHT...SUGGESTING THE POSSIBILITY THAT SOME FOG MAY HAVE DEVELOPED. AFTER SUNRISE...VIS SATELLITE IMAGERY WILL HELP SHED LIGHT ON WHETHER ANY FOG EXISTS. IF THERE IS NONE...FOG WILL LIKELY NOT BE AN ISSUE THROUGH WED. OTHERWISE...WINDS ARE EXPECTED TO REMAIN BELOW 20KT THROUGH FRI WITH ONE EXCEPTION. TROUGH MOVING ACROSS THE NORTHERN PLAINS WILL CAUSE SOUTHERLY WINDS WINDS TO INCREASE WED NIGHT. AS IS TYPICALLY THE CASE...SOUTHERLY WINDS WILL BE STRONGER OVER EASTERN LAKE SUPERIOR. ALTHOUGH WINDS AT BUOY OBSERVATION PLATFORMS WILL REMAIN BLO 20KT...HIGHER OBSERVING PLATFORMS WILL LIKELY SEE SUSTAINED WINDS OR FREQUENT GUSTS TO AROUND 25KT. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ AVIATION/MARINE...ROLFSON DISCUSSION...DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 417 AM EDT MON JUL 23 2007 .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE POTENTIAL THUNDERSTORMS TODAY AND TUESDAY. WATER VAPOR AND RUC/NAM SHOWING A CLOSED LOW OVER CENTRAL MID ATLANTIC STATES...A BROAD RIDGE BLANKETS MUCH OF THE WESTERN CONUS. THE RIDGE STRETCHES FROM THE NORTHERN PLAINS ACROSS THE FORECAST AREA INTO SOUTHERN QUEBEC AS WELL. WEAK SHORTWAVE PASSING THROUGH THE AREA TRIGGERED A FEW SHOWERS AND THUNDERSTORMS OVER THE AREA LAST EVENING. ANOTHER SHORTWAVE IS OVER NORTHEAST MINNESOTA AND CENTRAL ONTARIO. SURFACE ANALYSIS DEPICTS A RIDGE OVER THE LOWER GREAT LAKES EXTENDING INTO NORTHERN NEW ENGLAND. A LOW IS OVER MINNESOTA WITH A STATIONARY FRONT EXTENDING NORTHEAST INTO EASTERN HUDSON BAY...AND SOUTH OF THE LOW THROUGH THE CENTRAL PLAINS. ANOTHER LOW IS DEVELOP OVER THE HIGH PLAINS. LOW LEVEL MOISTURE AHEAD OF THE FRONTAL SYSTEM IS FAIRLY DRY AS ANOTHER COLD FRONT DRAPED ACROSS THE SOUTHERN STATES HAVE CUT OFF THE GULF MOISTURE FRONT REACH THE UPPER GREAT LAKES REGION. THE MID LEVEL LOW OVER THE MID ATLANTIC STATES WILL LIFT NORTHWEST THROUGH THE EASTERN OHIO RIVER VALLEY TODAY AND TONIGHT INTO THE LOWER GREAT LAKES WHERE IT WILL SPIN THROUGH TUESDAY. THE NORTHERN PLAINS HIGH WILL SLIDE OVER THE DAKOTAS. THE RIDGE WILL STILL EXTEND EAST ACROSS LAKE SUPERIOR INTO EAST CENTRAL ONTARIO. NAM/GFS DEVELOP MLCAPE VALUES AROUND 1000J/KG OVER THE WESTERN TWO THIRDS TODAY AND >2100J/KG OVER CENTRAL U.P. AROUND 18Z TUESDAY. CANADIAN GEM SHOWERS MEAN RH 65 TO 70 PERCENT OVER THE FORECAST AREA. THUS...WITH SOME DAYTIME HEATING...EXPECT A CHANCE OF SHOWERS AND THUNDERSTORMS OVER THE FORECAST AREA TODAY...MAINLY THE WEST HALF. THE CHANCES SHOULD DIMINISH THIS EVENING AS DAYTIME HEATING FALLS OFF. ON TUESDAY...AVAILABLE MOISTURE WILL STILL BE RATHER LIMITED. HOWEVER...WILL KEEP A SLIGHT CHANCE GOING. THE CLOSED LOW WILL REMAIN OVER LAKE ERIE THROUGH THURSDAY NIGHT. THE RIDGE OVER NORTHERN PLAINS WILL LIKEWISE REMAIN STATIONARY THROUGH WEDNESDAY. WEDNESDAY NIGHT THE RIDGE WILL SHIFT SOUTH INTO THE CENTRAL PLAINS. MEANWHILE...NUMEROUS WEAK SHORTWAVES WILL SWEEP THROUGH THE FORECAST AREA. THE FIRST WILL MOVE THROUGH THE AREA TUESDAY NIGHT FOLLOWED OTHERS THURSDAY AFTERNOON...AND THURSDAY NIGHT. A COLD FRONT WILL SWEEP THROUGH THE FORECAST AREA THURSDAY NIGHT. THE AIR MASS CONTINUES TO BE DRY. HOWEVER...AT THE SURFACE CONDITIONS WILL BE MOIST. A STRONG INVERSION WILL OCCUR AROUND 750MB. GFS/NAM SHOWS THE AIR MASS WILL BE DRY. BY NOON ON TUESDAY...NAM/GFS SHOWING MLCAPE VALUES WILL EXCEED 2K J/KG MAINLY OVER CENTRAL U.P. SURFACE DEW POINTS WILL REMAIN IN THE LOW TO MID 60S ACROSS THE AREA. NIGHTTIME COOLING INTO THE 60S SHOULD LEND ITSELF TO PRODUCING PATCHES OF FOG AROUND THE AREA. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... RADAR SHOWED DIMINISHING TREND WITH -SHRA INTO THE KEWEENAW AND N CENTRAL UPPER MICHIGAN. WITH ONLY WEAK LIFT EXPECTED WITH THE 850-700 MB WARM FRONT...NO ADDITIONAL -SHRA OR LOWER VSBY/CIGS WERE MENTIONED TONIGHT. EXPECT THE POTENTIAL FOR SOME INLAND SHRA/TSRA AT KSAW AS THE COMBINATION OF LAKE BREEZE AND A WEAK FRONT MOVE THROUGH. FOG COULD MOVE INTO KCMX MON EVENING AS WEAK EASTERLY WIND DEVELOPS PUSHING EXPECTED MARINE LAYER FOG INLAND. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... EXPECT SOME FOG TO BE FOUND ACROSS LAKE SUPERIOR TODAY THUR TUE THOUGH CONFIDENCE ON COVERAGE IS LOW. HAVE NOT SEEN ANY SHIP OBS INDICATING REDUCED VSBY...BUT THERE WERE SCATTERED SHRA OVER THE LAKE EARLIER IN THE NIGHT...SUGGESTING THE POSSIBILITY THAT SOME FOG MAY HAVE DEVELOPED. AFTER SUNRISE...VIS SATELLITE IMAGERY WILL HELP SHED LIGHT ON WHETHER ANY FOG EXISTS. IF THERE IS NONE...FOG WILL LIKELY NOT BE AN ISSUE THROUGH WED. OTHERWISE...WINDS ARE EXPECTED TO REMAIN BELOW 20KT THROUGH FRI WITH ONE EXCEPTION. TROUGH MOVING ACROSS THE NORTHERN PLAINS WILL CAUSE SOUTHERLY WINDS WINDS TO INCREASE WED NIGHT. AS IS TYPICALLY THE CASE...SOUTHERLY WINDS WILL BE STRONGER OVER EASTERN LAKE SUPERIOR. ALTHOUGH WINDS AT BUOY OBSERVATION PLATFORMS WILL REMAIN BLO 20KT...HIGHER OBSERVING PLATFORMS WILL LIKELY SEE SUSTAINED WINDS OR FREQUENT GUSTS TO AROUND 25KT. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ AVIATION...JLB MARINE...ROLFSON DISCUSSION...DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 130 AM EDT MON JUL 23 2007 UPDATED FOR TAF DISCUSSION .UPDATE (ISSUED AT 1045 PM EDT SUN JUL 22)... RADAR INDICATED ISOLD/SCT SHRA FROM CNTRL LAKE SUPERIOR INTO NORTH CENTRAL UPPER MI SUPPORTED BY A WEAK SHORTWAVE TROUGH AND 305K ISENTROPIC LIFT ASSOCIATED WITH THE 850-700 MB WARM FRONT. DESPITE MUCAPE VALUES OF AROUND 1K J/KG AND PLENTIFUL MOISTURE UPSTREAM (KDLH TAMDAR SOUNDING SHOWED 850 MB DEWPOINT OF 17C) THE RELATIVELY WEAK DYNAMICS WITH 20 KT 850-700 MB INFLOW AND WARM MID LEVELS HAVE LIMITED PCPN INTENSITY. EXPECT THAT THE DYNAMICS/LIFT WILL SUSTAIN ONLY ISOLD/SCT SHRA OVERNIGHT AND POSSIBLY A FEW TSRA. PCPN SHOULD ALSO HAVE A HARD TIME MOVING INTO THE SE CWA...AS IN THE GOING FCST...AS IT MOVES INTO A MUCH DRIER AIRMASS...PER KGRB/KAPX SOUNDINGS. && .PREV DISCUSSION (ISSUED 350 PM EDT SUN JUL 22 2007)... SYNOPSIS ... 19Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED STRONG UPPER RIDGING COVERING MUCH OF THE WESTERN 2/3 OF THE U.S. (598 DAM HIGH OVER WYOMING) WHILE AN UPPER LOW WAS PRESENT OVER WESTERN NORTH CAROLINA. ON THE NE SIDE OF THE UPPER RIDGE...A SHRTWV EXTENDED FROM NW ONTARIO INTO NW MINNESOTA. DPVA AHEAD OF THE SHRTWV...COMBINED WITH ELEVATED INSTABILITY AND STRONG 850MB THETA-E CONVERGENCE HAS SUPPORTED AN AREA OF CLOUDS...SHOWERS AND THUNDERSTORMS. THIS AREA THIS MORNING EXTENDED FROM NW ONTARIO THROUGH NORTHERN MN INTO NE NORTH DAKOTA...BUT NOW IS MORE ISOLATED EXCEPT FOR ONE MAIN CLUSTER MOVING SOUTH THROUGH WESTERN WI. FIGURE THAT THE DECREASE IN CONVECTION IS PROBABLY DIURNAL...ESPECIALLY SINCE IT IS ALL ELEVATED (ROOTED AROUND 850MB PER SOUNDING ANALYSIS) AND WINDS ACROSS NE MN IN THE 850MB AREA HAVE DECREASED 10 KT OR SO SINCE 12Z THIS MORNING PER TAMDAR SOUNDINGS. MUCH OF THE CWA IS DOMINATED BY A WEAK UPPER RIDGE DOWNSTREAM OF THE SHRTWV AND PLENTY OF DRY AIR (850MB DEWPOINT DEPRESSION AT 18Z AT CMX WAS 35C)...KEEPING ALL BUT THE FAR WESTERN CWA DRY. SUNSHINE DOWNSTREAM OF THE CLOUDS AND 850MB TEMPS IN THE 14 TO 16C RANGE HAS HELPED READINGS CLIMB AS HIGH AS THE LOW 80S AWAY FROM THE LAKE MICHIGAN SHORELINE. AS FAR AS THE SURFACE PATTERN GOES...A 1026MB HIGH WAS OVER LOWER MICHIGAN WHILE A SURFACE TROUGH EXTENDS FROM NW ONTARIO INTO CENTRAL SOUTH DAKOTA. HUMID CONDITIONS EXIST BOTH AT THE SURFACE AND ALOFT ALONG THE SURFACE TROUGH...WITH SURFACE DEWPOINTS IN THE LOW 70S AND 850MB DEWPOINTS AROUND 18C. SHORT TERM (TONIGHT AND MON)... MAIN FORECAST CONCERN IS PROBABILITY FOR RAIN TONIGHT/MONDAY. UPPER HIGH OVER WYOMING IS PROGGED TO LIFT INTO THE DAKOTAS ON MON...CAUSING THE SHRTWV OVER NW ONTARIO/NW MN TO DROP SE ACROSS THE CWA MON MORNING INTO EARLY MON AFTERNOON. AS THE SHRTWV MOVES SE...850MB THETA-E ADVECTION PRESENT ACROSS WESTERN WI AND WESTERN LAKE SUPERIOR WILL GRADUALLY PUSH EASTWARD. GIVEN THAT NOCTURNAL COOLING SHOULD STRENGTHEN THE WINDS AGAIN ALOFT...INCREASING THE 850MB CONVERGENCE...AND THE FACT THAT THE SHRTWV IS COMING TOWARDS THE CWA RESULTING IN HEIGHT FALLS...THERE SHOULD BE AN INCREASE IN SHOWER AND THUNDERSTORM COVERAGE BY LATE THIS EVENING. HOWEVER... UNTIL IT ACTUALLY HAPPENS AND THAT A RAPID UPDATE WRF-ARW RUN HERE DOES NOT INDICATE MUCH PCPN AT ALL THROUGH 06Z...HAVE LIMITED POPS TO NO HIGHER THAN CHANCE AND KEPT THE WORDING AS PROBABILITY INSTEAD OF COVERAGE. HIGHEST POPS...AROUND 50...REMAIN IN THE FAR WEST WHERE 850MB THETA-E CONVERGENCE IS STRONGEST. BY 12Z MON...THE CONVERGENCE REALLY STARTS TO DIMINISH...AND WITH A LACK OF DYNAMICS...HAVE LOWERED POPS TO NO HIGHER THAN 30 FOR MON. REDUCED POPS EVEN FURTHER OVER LAKES SUPERIOR AND MICHIGAN ON MON AS ANY THUNDERSTORMS SHOULD MAINLY BE ROOTED AT THE SURFACE. THIS IS ASSUMING THAT ENOUGH SUNSHINE CAN OCCUR THROUGH THE MOSTLY CLOUDY SKIES TO GET TEMPS UP AROUND 80. SOUNDINGS FOR AN 80/65 OVER THE WESTERN HALF OF THE U.P. RESULTS IN CAPE UP NEAR 1000 J/KG WITH NO CIN. FOR BOTH TONIGHT AND TOMORROW...DEEP WARM CLOUD DEPTHS... PRECIPITABLE WATER INCREASING TO 1.75 AND THIN CAPE PROFILE SUGGESTS MAIN HAZARD FROM THE STORMS WILL BE HEAVY RAIN. WILL CONTINUE TO HIGHLIGHT THE HEAVY RAIN POTENTIAL IN THE HWO. LOW TEMPERATURES TONIGHT WILL BE FAIRLY WARM...ESPECIALLY WITH DEWPOINTS ON THE INCREASE AND A 5-15 KT SOUTH WIND CONTINUING. HAVE RAISED HIGHS A FEW DEGREES FROM THE PREVIOUS FORECAST. ON MONDAY...ALL MODELS AGREE ON MORE CLOUDS...WHICH MAKES SENSE GIVEN THE CURRENT CLOUD COVER RIGHT NOW. THUS HAVE LOWERED HIGHS A BIT...ESPECIALLY IN THE WESTERN U.P.. LONG TERM (MON NIGHT THROUGH NEXT SUN)... IN THE ABSENCE OF ANY DYNAMIC SUPPORT...EXPECT ANY ONGOING CNVCTN ON MON AFTN TO COLLAPSE DURING THE EVNG WITH LOSS OF DIURNAL HTG. WITH MID LVL DRY AIR ABV LINGERING LLVL MSTR AND LGT WINDS EXPECTED UNDER FLAT PRES GRADIENT...SETUP SEEMS IDEAL FOR FOG TO DVLP AT NGT. CONSIDERING INFLUX OF LLVL MSTR...THINK GFS MOS GUIDANCE TEMPS LOOK TOO LO...SO TENDED MIDWAY BTWN THE GFS AND HIER ETA MOS NUMBERS. THERE WL BE NO DYNAMIC SUPPORT AGAIN ON TUE...SO FCST QUESTION WL BE WHETHER LK BREEZES/DIURNAL HTG/AMPLE LLVL MSTR WL BE ENUF TO OVERCOME WARM/STABLE MID LVLS TO GENERATE SHRA/TSRA. MODIFIED GFS FCST SDNG FOR IWD AT 18Z ON TUE SHOWS LOWEST 100MB MLCAPE OF 1800 J/KG WITH CIN ONLY -10 J/KG FOR SFC T/TD 85/67 AS MOIST ADIABAT JUST CLEARS CAP STRONGEST AT H65. SINCE KINX IS ONLY 27 WITH PRONOUNCED CAP IN PLACE...THINK A 20 POP SHOULD SUFFICE IN AGREEMENT WITH GFS MOS. AT ERY...MODIFIED GFS FCST SDNG FOR SFC T/TD 84/64 YIELDS LOWEST 100MB MLCAPE OF 735 J/KG (CIN ONLY 10 J/KG)...BUT KINX ONLY 25 WITH WARM/STABLE MID LVLS AS WELL. ELECTED TO ADD SCHC POP OVER THE INTERIOR E AS WELL WITH POTENTIAL FOR LK BREEZE CNVGC. THE TUE NGT THRU WED NGT PD WL BE DOMINATED BY BLDG RDG...WITH GFS SHOWING H5 TEMPS RISING TO -3C ON WED. ANY SHRA/TSRA WL DIE QUICKLY WITH LOSS OF DIURNAL HTG TUE EVNG...THEN TENDED TOWARD THE LOWER GFS MOS GUIDANCE IN THE PRESENCE OF LGT WINDS/LOWERING PWAT. SINCE LLVL MSTR/PWAT IS FCST TO BE A BIT LESS ON WED THAN ON TUE UNDER STRENGTHENING CAP...ELECTED TO MAINTAIN GOING DRY FCST EVEN WITH POTENTIAL FOR LK BREEZE DVLPMNT. WED SHOULD BE THE WARMEST DAY OF THE WEEK WITH DRIER TROP AND H85 TEMPS RISING TO ARND 20C OVER THE W. MIXING TO H75 ON GFS FCST SDNGS YIELDS TEMPS INTO THE LO 90S OVER THE INTERIOR W AWAY FM LK MODERATION. TEMPS WL NOT BE AS EXTREME OVER THE E HALF OF THE FA WITH SLY FLOW OFF LK MI. WED NGT SHOULD BE QUITE A BIT WARMER THAN ON TUE NGT WITH STRONGER SW FLOW/RETURNING HIER PWAT. INCLUDED GUSTY WINDS UP TO 25 KTS NR THE LK SUP SHORE AND ABV THE MARINE LYR ON LK SUP. OPERATIONAL 00Z MODELS/06Z GFS HAVE TRENDED FASTER BREAKING DOWN RDG OVER THE UPR GRT LKS THAT WL BE DOMINATING THE WX ON WED. FASTER GUIDANCE NOW SHOWING COLD FNT SWEEPING ACRS THE CWA ON THU...AND NCEP MANUAL GUIDANCE SHOWS THE FNT COMPLETELY CLR THRU THE FA BY 12Z FRI WITH FLOW ALF VEERING NW ACCOMPANYING HGT FALLS. TRENDED FASTER WITH ARRIVAL OF SHRA/TSRA CHCS ON THU AND ENDING POPS ON FRI... COMPLETELY PULLING SHRA/TSRA CHCS ON SAT MRNG BASED ON MODEL CONSENSUS/NCEP MANUAL GUIDANCE SHOWING DRY HI PRES BLDG IN ON SAT. 12Z GFS HAS CONTINUED THESE TRENDS. MODEL SHOWS PWAT AOA 2 INCHES POOLING ALG FNT WITH KINX AS HI AS 40. THIS MSTR WOULD SUPPORT HVY RA AS THE PRIMARY THREAT WITH WEAK SHEAR/DEEP WARM CLD DEPTH. ALSO TRENDED LOWER WITH TEMPS ON THU/FRI TO ACCOUNT FOR QUICKER BREAKDOWN OF RDG/ARRIVAL OF MORE MSTR/FASTER COLD FROPA. ALTHOUGH LATEST GFS SHOWS MSTR RETURN NEXT SUN IN RETURN SW FLOW ARND HI PRES MOVING TO THE E...WENT DRY FOR NOW WITH NCEP MANUAL GUIDANCE/00Z ECMWF SHOWING MORE PERSISTENT RDG OVER THE UPR LKS. COORDINATED WITH APX/GRB/DLH. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... RADAR SHOWED DIMINISHING TREND WITH -SHRA INTO THE KEWEENAW AND N CENTRAL UPPER MICHIGAN. WITH ONLY WEAK LIFT EXPECTED WITH THE 850-700 MB WARM FRONT...NO ADDITIONAL -SHRA OR LOWER VSBY/CIGS WERE MENTIONED TONIGHT. EXPECT THE POTENTIAL FOR SOME INLAND SHRA/TSRA AT KSAW AS THE COMBINATION OF LAKE BREEZE AND A WEAK FRONT MOVE THROUGH. FOG COULD MOVE INTO KCMX MON EVENING AS WEAK ERLY DEVELOPS PUSHING EXPECTED MARINE LAYER FOG INLAND. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... WINDS ARE EXPECTED TO MOSTLY REMAIN BELOW 20 KT THROUGH FRI. HOWEVER...WINDS MAY APPROACH 20 KT BOTH TONIGHT AND WED NIGHT ON EASTERN LAKE SUPERIOR...DUE TO TROUGHS APPROACHING FROM NW ONTARIO BUTTING UP AGAINST HIGH PRESSURE STUCK OVER LAKE ERIE. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE...JLB AVIATION...JLB SHORT TERM/MARINE...AJ LONG TERM...KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1045 PM EDT SUN JUL 22 2007 .UPDATE... RADAR INDICATED ISOLD/SCT SHRA FROM CNTRL LAKE SUPERIOR INTO NORTH CENTRAL UPPER MI SUPPORTED BY A WEAK SHORTWAVE TROUGH AND 305K ISENTROPIC LIFT ASSOCIATED WITH THE 850-700 MB WARM FRONT. DESPITE MUCAPE VALUES OF AROUND 1K J/KG AND PLENTIFUL MOISTURE UPSTREAM (KDLH TAMDAR SOUNDING SHOWED 850 MB DEWPOINT OF 17C) THE RELATIVELY WEAK DYNAMICS WITH 20 KT 850-700 MB INFLOW AND WARM MID LEVELS HAVE LIMITED PCPN INTENSITY. EXPECT THAT THE DYNAMICS/LIFT WILL SUSTAIN ONLY ISOLD/SCT SHRA OVERNIGHT AND POSSIBLY A FEW TSRA. PCPN SHOULD ALSO HAVE A HARD TIME MOVING INTO THE SE CWA...AS IN THE GOING FCST...AS IT MOVES INTO A MUCH DRIER AIRMASS...PER KGRB/KAPX SOUNDINGS. && .SYNOPSIS...ISSUED 350 PM EDT SUN JUL 22 2007 19Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED STRONG UPPER RIDGING COVERING MUCH OF THE WESTERN 2/3 OF THE U.S. (598 DAM HIGH OVER WYOMING) WHILE AN UPPER LOW WAS PRESENT OVER WESTERN NORTH CAROLINA. ON THE NE SIDE OF THE UPPER RIDGE...A SHRTWV EXTENDED FROM NW ONTARIO INTO NW MINNESOTA. DPVA AHEAD OF THE SHRTWV...COMBINED WITH ELEVATED INSTABILITY AND STRONG 850MB THETA-E CONVERGENCE HAS SUPPORTED AN AREA OF CLOUDS...SHOWERS AND THUNDERSTORMS. THIS AREA THIS MORNING EXTENDED FROM NW ONTARIO THROUGH NORTHERN MN INTO NE NORTH DAKOTA...BUT NOW IS MORE ISOLATED EXCEPT FOR ONE MAIN CLUSTER MOVING SOUTH THROUGH WESTERN WI. FIGURE THAT THE DECREASE IN CONVECTION IS PROBABLY DIURNAL...ESPECIALLY SINCE IT IS ALL ELEVATED (ROOTED AROUND 850MB PER SOUNDING ANALYSIS) AND WINDS ACROSS NE MN IN THE 850MB AREA HAVE DECREASED 10 KT OR SO SINCE 12Z THIS MORNING PER TAMDAR SOUNDINGS. MUCH OF THE CWA IS DOMINATED BY A WEAK UPPER RIDGE DOWNSTREAM OF THE SHRTWV AND PLENTY OF DRY AIR (850MB DEWPOINT DEPRESSION AT 18Z AT CMX WAS 35C)...KEEPING ALL BUT THE FAR WESTERN CWA DRY. SUNSHINE DOWNSTREAM OF THE CLOUDS AND 850MB TEMPS IN THE 14 TO 16C RANGE HAS HELPED READINGS CLIMB AS HIGH AS THE LOW 80S AWAY FROM THE LAKE MICHIGAN SHORELINE. AS FAR AS THE SURFACE PATTERN GOES...A 1026MB HIGH WAS OVER LOWER MICHIGAN WHILE A SURFACE TROUGH EXTENDS FROM NW ONTARIO INTO CENTRAL SOUTH DAKOTA. HUMID CONDITIONS EXIST BOTH AT THE SURFACE AND ALOFT ALONG THE SURFACE TROUGH...WITH SURFACE DEWPOINTS IN THE LOW 70S AND 850MB DEWPOINTS AROUND 18C. && .SHORT TERM (TONIGHT AND MON)... MAIN FORECAST CONCERN IS PROBABILITY FOR RAIN TONIGHT/MONDAY. UPPER HIGH OVER WYOMING IS PROGGED TO LIFT INTO THE DAKOTAS ON MON...CAUSING THE SHRTWV OVER NW ONTARIO/NW MN TO DROP SE ACROSS THE CWA MON MORNING INTO EARLY MON AFTERNOON. AS THE SHRTWV MOVES SE...850MB THETA-E ADVECTION PRESENT ACROSS WESTERN WI AND WESTERN LAKE SUPERIOR WILL GRADUALLY PUSH EASTWARD. GIVEN THAT NOCTURNAL COOLING SHOULD STRENGTHEN THE WINDS AGAIN ALOFT...INCREASING THE 850MB CONVERGENCE...AND THE FACT THAT THE SHRTWV IS COMING TOWARDS THE CWA RESULTING IN HEIGHT FALLS...THERE SHOULD BE AN INCREASE IN SHOWER AND THUNDERSTORM COVERAGE BY LATE THIS EVENING. HOWEVER... UNTIL IT ACTUALLY HAPPENS AND THAT A RAPID UPDATE WRF-ARW RUN HERE DOES NOT INDICATE MUCH PCPN AT ALL THROUGH 06Z...HAVE LIMITED POPS TO NO HIGHER THAN CHANCE AND KEPT THE WORDING AS PROBABILITY INSTEAD OF COVERAGE. HIGHEST POPS...AROUND 50...REMAIN IN THE FAR WEST WHERE 850MB THETA-E CONVERGENCE IS STRONGEST. BY 12Z MON...THE CONVERGENCE REALLY STARTS TO DIMINISH...AND WITH A LACK OF DYNAMICS...HAVE LOWERED POPS TO NO HIGHER THAN 30 FOR MON. REDUCED POPS EVEN FURTHER OVER LAKES SUPERIOR AND MICHIGAN ON MON AS ANY THUNDERSTORMS SHOULD MAINLY BE ROOTED AT THE SURFACE. THIS IS ASSUMING THAT ENOUGH SUNSHINE CAN OCCUR THROUGH THE MOSTLY CLOUDY SKIES TO GET TEMPS UP AROUND 80. SOUNDINGS FOR AN 80/65 OVER THE WESTERN HALF OF THE U.P. RESULTS IN CAPE UP NEAR 1000 J/KG WITH NO CIN. FOR BOTH TONIGHT AND TOMORROW...DEEP WARM CLOUD DEPTHS... PRECIPITABLE WATER INCREASING TO 1.75 AND THIN CAPE PROFILE SUGGESTS MAIN HAZARD FROM THE STORMS WILL BE HEAVY RAIN. WILL CONTINUE TO HIGHLIGHT THE HEAVY RAIN POTENTIAL IN THE HWO. LOW TEMPERATURES TONIGHT WILL BE FAIRLY WARM...ESPECIALLY WITH DEWPOINTS ON THE INCREASE AND A 5-15 KT SOUTH WIND CONTINUING. HAVE RAISED HIGHS A FEW DEGREES FROM THE PREVIOUS FORECAST. ON MONDAY...ALL MODELS AGREE ON MORE CLOUDS...WHICH MAKES SENSE GIVEN THE CURRENT CLOUD COVER RIGHT NOW. THUS HAVE LOWERED HIGHS A BIT...ESPECIALLY IN THE WESTERN U.P.. .LONG TERM (MON NIGHT THROUGH NEXT SUN)... IN THE ABSENCE OF ANY DYNAMIC SUPPORT...EXPECT ANY ONGOING CNVCTN ON MON AFTN TO COLLAPSE DURING THE EVNG WITH LOSS OF DIURNAL HTG. WITH MID LVL DRY AIR ABV LINGERING LLVL MSTR AND LGT WINDS EXPECTED UNDER FLAT PRES GRADIENT...SETUP SEEMS IDEAL FOR FOG TO DVLP AT NGT. CONSIDERING INFLUX OF LLVL MSTR...THINK GFS MOS GUIDANCE TEMPS LOOK TOO LO...SO TENDED MIDWAY BTWN THE GFS AND HIER ETA MOS NUMBERS. THERE WL BE NO DYNAMIC SUPPORT AGAIN ON TUE...SO FCST QUESTION WL BE WHETHER LK BREEZES/DIURNAL HTG/AMPLE LLVL MSTR WL BE ENUF TO OVERCOME WARM/STABLE MID LVLS TO GENERATE SHRA/TSRA. MODIFIED GFS FCST SDNG FOR IWD AT 18Z ON TUE SHOWS LOWEST 100MB MLCAPE OF 1800 J/KG WITH CIN ONLY -10 J/KG FOR SFC T/TD 85/67 AS MOIST ADIABAT JUST CLEARS CAP STRONGEST AT H65. SINCE KINX IS ONLY 27 WITH PRONOUNCED CAP IN PLACE...THINK A 20 POP SHOULD SUFFICE IN AGREEMENT WITH GFS MOS. AT ERY...MODIFIED GFS FCST SDNG FOR SFC T/TD 84/64 YIELDS LOWEST 100MB MLCAPE OF 735 J/KG (CIN ONLY 10 J/KG)...BUT KINX ONLY 25 WITH WARM/STABLE MID LVLS AS WELL. ELECTED TO ADD SCHC POP OVER THE INTERIOR E AS WELL WITH POTENTIAL FOR LK BREEZE CNVGC. THE TUE NGT THRU WED NGT PD WL BE DOMINATED BY BLDG RDG...WITH GFS SHOWING H5 TEMPS RISING TO -3C ON WED. ANY SHRA/TSRA WL DIE QUICKLY WITH LOSS OF DIURNAL HTG TUE EVNG...THEN TENDED TOWARD THE LOWER GFS MOS GUIDANCE IN THE PRESENCE OF LGT WINDS/LOWERING PWAT. SINCE LLVL MSTR/PWAT IS FCST TO BE A BIT LESS ON WED THAN ON TUE UNDER STRENGTHENING CAP...ELECTED TO MAINTAIN GOING DRY FCST EVEN WITH POTENTIAL FOR LK BREEZE DVLPMNT. WED SHOULD BE THE WARMEST DAY OF THE WEEK WITH DRIER TROP AND H85 TEMPS RISING TO ARND 20C OVER THE W. MIXING TO H75 ON GFS FCST SDNGS YIELDS TEMPS INTO THE LO 90S OVER THE INTERIOR W AWAY FM LK MODERATION. TEMPS WL NOT BE AS EXTREME OVER THE E HALF OF THE FA WITH SLY FLOW OFF LK MI. WED NGT SHOULD BE QUITE A BIT WARMER THAN ON TUE NGT WITH STRONGER SW FLOW/RETURNING HIER PWAT. INCLUDED GUSTY WINDS UP TO 25 KTS NR THE LK SUP SHORE AND ABV THE MARINE LYR ON LK SUP. OPERATIONAL 00Z MODELS/06Z GFS HAVE TRENDED FASTER BREAKING DOWN RDG OVER THE UPR GRT LKS THAT WL BE DOMINATING THE WX ON WED. FASTER GUIDANCE NOW SHOWING COLD FNT SWEEPING ACRS THE CWA ON THU...AND NCEP MANUAL GUIDANCE SHOWS THE FNT COMPLETELY CLR THRU THE FA BY 12Z FRI WITH FLOW ALF VEERING NW ACCOMPANYING HGT FALLS. TRENDED FASTER WITH ARRIVAL OF SHRA/TSRA CHCS ON THU AND ENDING POPS ON FRI... COMPLETELY PULLING SHRA/TSRA CHCS ON SAT MRNG BASED ON MODEL CONSENSUS/NCEP MANUAL GUIDANCE SHOWING DRY HI PRES BLDG IN ON SAT. 12Z GFS HAS CONTINUED THESE TRENDS. MODEL SHOWS PWAT AOA 2 INCHES POOLING ALG FNT WITH KINX AS HI AS 40. THIS MSTR WOULD SUPPORT HVY RA AS THE PRIMARY THREAT WITH WEAK SHEAR/DEEP WARM CLD DEPTH. ALSO TRENDED LOWER WITH TEMPS ON THU/FRI TO ACCOUNT FOR QUICKER BREAKDOWN OF RDG/ARRIVAL OF MORE MSTR/FASTER COLD FROPA. ALTHOUGH LATEST GFS SHOWS MSTR RETURN NEXT SUN IN RETURN SW FLOW ARND HI PRES MOVING TO THE E...WENT DRY FOR NOW WITH NCEP MANUAL GUIDANCE/00Z ECMWF SHOWING MORE PERSISTENT RDG OVER THE UPR LKS. COORDINATED WITH APX/GRB/DLH. && .AVIATION (FOR THE 00Z TAF ISSUANCE)... WRLY 850-700 MB FLOW WAS BRINGING MOISTURE/INSTABILITY INTO THE AREA WITH ISENTROPIC LIFT SUPPORTING A BAND OF SHRA/TSRA FROM N CNTRL LAKE SUPERIOR INTO THE KEWEENAW. EXPECT POTENTIAL FOR ADDITIONAL NOCTURNAL CONVECTION WITH MORE FAVORABLE CONDITIONS FOR LLJ MOISTURE TRANSPORT/LIFT. THE SHRA/TSRA SHOULD DIMINISH MON MORNING LEAVING CIGS JUST AOA MVFR AS ABUNDANT 900-700 MB MOISTURE LINGERS. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... WINDS ARE EXPECTED TO MOSTLY REMAIN BELOW 20 KT THROUGH FRI. HOWEVER...WINDS MAY APPROACH 20 KT BOTH TONIGHT AND WED NIGHT ON EASTERN LAKE SUPERIOR...DUE TO TROUGHS APPROACHING FROM NW ONTARIO BUTTING UP AGAINST HIGH PRESSURE STUCK OVER LAKE ERIE. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE...JLB AVIATION...JLB SHORT TERM/ARINE...AJ LONG TERM...KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 745 PM EDT SUN JUL 22 2007 .SYNOPSIS... 19Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED STRONG UPPER RIDGING COVERING MUCH OF THE WESTERN 2/3 OF THE U.S. (598 DAM HIGH OVER WYOMING) WHILE AN UPPER LOW WAS PRESENT OVER WESTERN NORTH CAROLINA. ON THE NE SIDE OF THE UPPER RIDGE...A SHRTWV EXTENDED FROM NW ONTARIO INTO NW MINNESOTA. DPVA AHEAD OF THE SHRTWV...COMBINED WITH ELEVATED INSTABILITY AND STRONG 850MB THETA-E CONVERGENCE HAS SUPPORTED AN AREA OF CLOUDS...SHOWERS AND THUNDERSTORMS. THIS AREA THIS MORNING EXTENDED FROM NW ONTARIO THROUGH NORTHERN MN INTO NE NORTH DAKOTA...BUT NOW IS MORE ISOLATED EXCEPT FOR ONE MAIN CLUSTER MOVING SOUTH THROUGH WESTERN WI. FIGURE THAT THE DECREASE IN CONVECTION IS PROBABLY DIURNAL...ESPECIALLY SINCE IT IS ALL ELEVATED (ROOTED AROUND 850MB PER SOUNDING ANALYSIS) AND WINDS ACROSS NE MN IN THE 850MB AREA HAVE DECREASED 10 KT OR SO SINCE 12Z THIS MORNING PER TAMDAR SOUNDINGS. MUCH OF THE CWA IS DOMINATED BY A WEAK UPPER RIDGE DOWNSTREAM OF THE SHRTWV AND PLENTY OF DRY AIR (850MB DEWPOINT DEPRESSION AT 18Z AT CMX WAS 35C)...KEEPING ALL BUT THE FAR WESTERN CWA DRY. SUNSHINE DOWNSTREAM OF THE CLOUDS AND 850MB TEMPS IN THE 14 TO 16C RANGE HAS HELPED READINGS CLIMB AS HIGH AS THE LOW 80S AWAY FROM THE LAKE MICHIGAN SHORELINE. AS FAR AS THE SURFACE PATTERN GOES...A 1026MB HIGH WAS OVER LOWER MICHIGAN WHILE A SURFACE TROUGH EXTENDS FROM NW ONTARIO INTO CENTRAL SOUTH DAKOTA. HUMID CONDITIONS EXIST BOTH AT THE SURFACE AND ALOFT ALONG THE SURFACE TROUGH...WITH SURFACE DEWPOINTS IN THE LOW 70S AND 850MB DEWPOINTS AROUND 18C. && .SHORT TERM (TONIGHT AND MON)... MAIN FORECAST CONCERN IS PROBABILITY FOR RAIN TONIGHT/MONDAY. UPPER HIGH OVER WYOMING IS PROGGED TO LIFT INTO THE DAKOTAS ON MON...CAUSING THE SHRTWV OVER NW ONTARIO/NW MN TO DROP SE ACROSS THE CWA MON MORNING INTO EARLY MON AFTERNOON. AS THE SHRTWV MOVES SE...850MB THETA-E ADVECTION PRESENT ACROSS WESTERN WI AND WESTERN LAKE SUPERIOR WILL GRADUALLY PUSH EASTWARD. GIVEN THAT NOCTURNAL COOLING SHOULD STRENGTHEN THE WINDS AGAIN ALOFT...INCREASING THE 850MB CONVERGENCE...AND THE FACT THAT THE SHRTWV IS COMING TOWARDS THE CWA RESULTING IN HEIGHT FALLS...THERE SHOULD BE AN INCREASE IN SHOWER AND THUNDERSTORM COVERAGE BY LATE THIS EVENING. HOWEVER... UNTIL IT ACTUALLY HAPPENS AND THAT A RAPID UPDATE WRF-ARW RUN HERE DOES NOT INDICATE MUCH PCPN AT ALL THROUGH 06Z...HAVE LIMITED POPS TO NO HIGHER THAN CHANCE AND KEPT THE WORDING AS PROBABILITY INSTEAD OF COVERAGE. HIGHEST POPS...AROUND 50...REMAIN IN THE FAR WEST WHERE 850MB THETA-E CONVERGENCE IS STRONGEST. BY 12Z MON...THE CONVERGENCE REALLY STARTS TO DIMINISH...AND WITH A LACK OF DYNAMICS...HAVE LOWERED POPS TO NO HIGHER THAN 30 FOR MON. REDUCED POPS EVEN FURTHER OVER LAKES SUPERIOR AND MICHIGAN ON MON AS ANY THUNDERSTORMS SHOULD MAINLY BE ROOTED AT THE SURFACE. THIS IS ASSUMING THAT ENOUGH SUNSHINE CAN OCCUR THROUGH THE MOSTLY CLOUDY SKIES TO GET TEMPS UP AROUND 80. SOUNDINGS FOR AN 80/65 OVER THE WESTERN HALF OF THE U.P. RESULTS IN CAPE UP NEAR 1000 J/KG WITH NO CIN. FOR BOTH TONIGHT AND TOMORROW...DEEP WARM CLOUD DEPTHS... PRECIPITABLE WATER INCREASING TO 1.75 AND THIN CAPE PROFILE SUGGESTS MAIN HAZARD FROM THE STORMS WILL BE HEAVY RAIN. WILL CONTINUE TO HIGHLIGHT THE HEAVY RAIN POTENTIAL IN THE HWO. LOW TEMPERATURES TONIGHT WILL BE FAIRLY WARM...ESPECIALLY WITH DEWPOINTS ON THE INCREASE AND A 5-15 KT SOUTH WIND CONTINUING. HAVE RAISED HIGHS A FEW DEGREES FROM THE PREVIOUS FORECAST. ON MONDAY...ALL MODELS AGREE ON MORE CLOUDS...WHICH MAKES SENSE GIVEN THE CURRENT CLOUD COVER RIGHT NOW. THUS HAVE LOWERED HIGHS A BIT...ESPECIALLY IN THE WESTERN U.P.. .LONG TERM (MON NIGHT THROUGH NEXT SUN)... IN THE ABSENCE OF ANY DYNAMIC SUPPORT...EXPECT ANY ONGOING CNVCTN ON MON AFTN TO COLLAPSE DURING THE EVNG WITH LOSS OF DIURNAL HTG. WITH MID LVL DRY AIR ABV LINGERING LLVL MSTR AND LGT WINDS EXPECTED UNDER FLAT PRES GRADIENT...SETUP SEEMS IDEAL FOR FOG TO DVLP AT NGT. CONSIDERING INFLUX OF LLVL MSTR...THINK GFS MOS GUIDANCE TEMPS LOOK TOO LO...SO TENDED MIDWAY BTWN THE GFS AND HIER ETA MOS NUMBERS. THERE WL BE NO DYNAMIC SUPPORT AGAIN ON TUE...SO FCST QUESTION WL BE WHETHER LK BREEZES/DIURNAL HTG/AMPLE LLVL MSTR WL BE ENUF TO OVERCOME WARM/STABLE MID LVLS TO GENERATE SHRA/TSRA. MODIFIED GFS FCST SDNG FOR IWD AT 18Z ON TUE SHOWS LOWEST 100MB MLCAPE OF 1800 J/KG WITH CIN ONLY -10 J/KG FOR SFC T/TD 85/67 AS MOIST ADIABAT JUST CLEARS CAP STRONGEST AT H65. SINCE KINX IS ONLY 27 WITH PRONOUNCED CAP IN PLACE...THINK A 20 POP SHOULD SUFFICE IN AGREEMENT WITH GFS MOS. AT ERY...MODIFIED GFS FCST SDNG FOR SFC T/TD 84/64 YIELDS LOWEST 100MB MLCAPE OF 735 J/KG (CIN ONLY 10 J/KG)...BUT KINX ONLY 25 WITH WARM/STABLE MID LVLS AS WELL. ELECTED TO ADD SCHC POP OVER THE INTERIOR E AS WELL WITH POTENTIAL FOR LK BREEZE CNVGC. THE TUE NGT THRU WED NGT PD WL BE DOMINATED BY BLDG RDG...WITH GFS SHOWING H5 TEMPS RISING TO -3C ON WED. ANY SHRA/TSRA WL DIE QUICKLY WITH LOSS OF DIURNAL HTG TUE EVNG...THEN TENDED TOWARD THE LOWER GFS MOS GUIDANCE IN THE PRESENCE OF LGT WINDS/LOWERING PWAT. SINCE LLVL MSTR/PWAT IS FCST TO BE A BIT LESS ON WED THAN ON TUE UNDER STRENGTHENING CAP...ELECTED TO MAINTAIN GOING DRY FCST EVEN WITH POTENTIAL FOR LK BREEZE DVLPMNT. WED SHOULD BE THE WARMEST DAY OF THE WEEK WITH DRIER TROP AND H85 TEMPS RISING TO ARND 20C OVER THE W. MIXING TO H75 ON GFS FCST SDNGS YIELDS TEMPS INTO THE LO 90S OVER THE INTERIOR W AWAY FM LK MODERATION. TEMPS WL NOT BE AS EXTREME OVER THE E HALF OF THE FA WITH SLY FLOW OFF LK MI. WED NGT SHOULD BE QUITE A BIT WARMER THAN ON TUE NGT WITH STRONGER SW FLOW/RETURNING HIER PWAT. INCLUDED GUSTY WINDS UP TO 25 KTS NR THE LK SUP SHORE AND ABV THE MARINE LYR ON LK SUP. OPERATIONAL 00Z MODELS/06Z GFS HAVE TRENDED FASTER BREAKING DOWN RDG OVER THE UPR GRT LKS THAT WL BE DOMINATING THE WX ON WED. FASTER GUIDANCE NOW SHOWING COLD FNT SWEEPING ACRS THE CWA ON THU...AND NCEP MANUAL GUIDANCE SHOWS THE FNT COMPLETELY CLR THRU THE FA BY 12Z FRI WITH FLOW ALF VEERING NW ACCOMPANYING HGT FALLS. TRENDED FASTER WITH ARRIVAL OF SHRA/TSRA CHCS ON THU AND ENDING POPS ON FRI... COMPLETELY PULLING SHRA/TSRA CHCS ON SAT MRNG BASED ON MODEL CONSENSUS/NCEP MANUAL GUIDANCE SHOWING DRY HI PRES BLDG IN ON SAT. 12Z GFS HAS CONTINUED THESE TRENDS. MODEL SHOWS PWAT AOA 2 INCHES POOLING ALG FNT WITH KINX AS HI AS 40. THIS MSTR WOULD SUPPORT HVY RA AS THE PRIMARY THREAT WITH WEAK SHEAR/DEEP WARM CLD DEPTH. ALSO TRENDED LOWER WITH TEMPS ON THU/FRI TO ACCOUNT FOR QUICKER BREAKDOWN OF RDG/ARRIVAL OF MORE MSTR/FASTER COLD FROPA. ALTHOUGH LATEST GFS SHOWS MSTR RETURN NEXT SUN IN RETURN SW FLOW ARND HI PRES MOVING TO THE E...WENT DRY FOR NOW WITH NCEP MANUAL GUIDANCE/00Z ECMWF SHOWING MORE PERSISTENT RDG OVER THE UPR LKS. COORDINATED WITH APX/GRB/DLH. && .AVIATION (FOR THE 00Z TAF ISSUANCE)... WRLY 850-700 MB FLOW WAS BRINGING MOISTURE/INSTABILITY INTO THE AREA WITH ISENTROPIC LIFT SUPPORTING A BAND OF SHRA/TSRA FROM N CNTRL LAKE SUPERIOR INTO THE KEWEENAW. EXPECT POTENTIAL FOR ADDITIONAL NOCTURNAL CONVECTION WITH MORE FAVORABLE CONDITIONS FOR LLJ MOISTURE TRANSPORT/LIFT. THE SHRA/TSRA SHOULD DIMINISH MON MORNING LEAVING CIGS JUST AOA MVFR AS ABUNDANT 900-700 MB MOISTURE LINGERS. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... WINDS ARE EXPECTED TO MOSTLY REMAIN BELOW 20 KT THROUGH FRI. HOWEVER...WINDS MAY APPROACH 20 KT BOTH TONIGHT AND WED NIGHT ON EASTERN LAKE SUPERIOR...DUE TO TROUGHS APPROACHING FROM NW ONTARIO BUTTING UP AGAINST HIGH PRESSURE STUCK OVER LAKE ERIE. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM/AVIATION/MARINE...AJ LONG TERM...KC mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 139 PM EDT SUN JUL 22 2007 UPDATED AVIATION FOR 18Z TAF ISSUANCE .SYNOPSIS... 14Z WATER VAPOR LOOP...12Z RAOBS AND RUC 500MB HEIGHT ANALYSIS SHOWED A 597 DAM HIGH CENTERED OVER WYOMING...WITH TWO WEAK RIDGES EXTENDING OFF OF IT INTO NW NORTH DAKOTA AND TOWARDS LAKE SUPERIOR. BETWEEN THESE RIDGES IS A SHRTWV TROUGH WHICH EXTENDS FROM EASTERN MANITOBA SOUTHWARD INTO EASTERN NORTH DAKOTA. DPVA DOWNSTREAM OF THE SHRTWV...COMBINED WITH ELEVATED INSTABILITY AND STRONG 850MB THETA-E CONVERGENCE HAS SUPPORTED AN AREA OF CLOUDS...SHOWERS AND THUNDERSTORMS. THIS AREA EXTENDS FROM NW ONTARIO INTO NORTHERN MN AND NE SOUTH DAKOTA. MESOANALYSIS USING RUC DATA SHOWS MUCAPE VALUES OF 1000-3000 J/KG WEST OF DLH LIFTED FROM AROUND 850MB. 12Z SOUNDINGS DEPICTED THE MUCAPE AREA AS ALSO HAVING 850MB DEWPOINTS BETWEEN 15-18C (PER CWPL...INL AND MPX SOUNDINGS)...THUS PCPN IN THIS AIRMASS HAS BEEN PRODUCING DECENT RAINFALL RATES AS SHOWN BY KDLH RADAR STORM TOTAL PRECIP GRAPHIC. COMPARE THESE DEWPOINTS TO FARTHER EAST WHERE GRB 850MB DEWPOINT WAS 7C AND APX WAS -3C. TO GIVE AN IDEA OF THE STRONG 850MB THETA-E ADVECTION OCCURRING... BETWEEN 00Z-11Z AT INL...THE PRECIPITABLE WATER JUMPED FROM 0.59 INCHES TO 1.68 INCHES AND THE K-INDEX JUMPED FROM -19 TO 42. OVER OUR CWA...THE AIRMASS HAS SHOWN ABOVE IS MUCH DRIER...THUS THE ONLY CLOUDS THAT HAVE BEEN TRAVERSING THE AREA HAVE BEEN OF THE CIRRUS VARIETY. HOWEVER...CLOUDS FROM MN ARE APPROACHING IWD. DAYTIME MIXING SO FAR HAS ALLOWED READINGS IN MOST AREAS TO REACH THE LOW 70S. && .UPDATE... MAIN CONCERN IS THE TRACK OF THE CONVECTION ACROSS NE MN. FROM OPERATIONAL AND LOCAL WRF-ARW MODELS...NUMEROUS IDEAS ARE PRESENT AS TO WHERE THE CONVECTION ACROSS NE MN WILL GO. 00Z LOCAL WRF-ARW RUN HAD AN EXCELLENT HANDLE WITH THE CONVECTION...AND IT DEPICTS THE PCPN DROPPING DUE SOUTH...FOLLOWING THE CORFIDI VECTORS. THE 06Z GFS AND 00Z CANADIAN DEPICT THE SAME...THOUGH MAINTAIN SOME SHOWERS AND THUNDERSTORMS NORTHWARD ALONG THE SHRTWV TROUGH ACROSS WESTERN LAKE SUPERIOR IN THE AFTERNOON. THE 06Z AND 12Z CYCLES OF THE NAM REALLY DO NOT HAVE A GOOD HANDLE ON THE PCPN... THUS WERE EXCLUDED. HAVE DECIDED TO FOLLOW THE 06Z GFS IDEA FOR A FEW REASONS. FIRST...THE 12Z SOUNDING FROM MPX DEPICTS PLENTY OF ELEVATED INSTABILITY...WHICH COULD BECOME SURFACE BASED IF TEMPS THERE REACHED INTO THE LOW 90S. THEREFORE...WITH CORFIDI VECTORS SUGGESTING A SOUTHWARD MOVEMENT AND THE BEST INSTABILITY TO THE SOUTH...THE BULK OF THE PCPN OVER DLHS AREA SHOULD DROP SOUTH. HOWEVER...BETTER 500MB HEIGHT FALLS AND 850MB THETA-E CONVERGENCE PROGRESS EASTWARD THROUGH THE DAY ASSOCIATED WITH THE SHRTWV TROUGH...THUS AM EXPECTING SOME OF THE SHOWERS AND THUNDERSTORMS OVER DLHS AREA TO ALSO MOVE EAST. GIVEN THIS...HAVE DECIDED TO RAISE POPS TO LIKELY OVER FAR WESTERN LAKE SUPERIOR THIS AFTERNOON AND THE FAR WESTERN U.P. THIS EVENING. AGAIN...WITH HIGH 850MB DEWPOINTS AND PRECIPITABLE WATER MOVING IN...ANY STORM WILL LIKELY PRODUCE HEAVY RAINFALL. FOR THE REST OF THE CWA...DRY AIR ASSOCIATED WITH HIGH PRESSURE IN LOWER MICHIGAN WILL KEEP THE WEATHER QUIET THROUGH EARLY THIS EVENING (OR LONGER IN THE CASE OF THE EASTERN U.P.). WITH ONLY A FEW HIGH CLOUDS MOVING ACROSS...SOUTHERLY WINDS INCREASING AND 850MB TEMPS RISING TO 12C EAST TO 16C WEST BY 18Z...TEMPS SHOULD REACH THE GOING FORECAST HIGHS. && .DISCUSSION (ISSUED AT 458 AM EDT)... UPR LEVEL RIDGE TO THE WEST RE-ORIENTS THROUGH THE DAY IN RESPONSE TO PACKETS OF SHORTWAVE ENERGY SLIDING ALONG US/CANADIAN BORDER. HEIGHT FALLS AT H5 NOT TOO IMPRESSIVE...BUT THERE ARE SOME HEIGHT FALLS AT H85. AS H85 HEIGHTS FALL...WINDS BACK MORE W/SW INTO UPR MISSISSIPPI RIVER VALLEY AND THE DEEP MOISTURE SHOWING UP AS WELL ABOVE NORMAL PWATS OVR DAKOTAS WILL STREAM EAST ACROSS MN INTO FAR WESTERN UPR GREAT LAKES. NAM/GFS ISENTROPIC LIFT ON THE 310K SFC SHOW THIS AS DOES H85 THETA-E PROGS. EXPECT MID LEVEL CLOUDS TO CONTINUE TO SPREAD EAST THIS MORNING INTO WESTERN UPPER MICHIGAN. HOW QUICKLY WILL PCPN BEGIN FALLING FM THIS MID CLOUD DECK IS MAIN QUESTION FOR TODAY. 310K ISENTROPIC LIFT MAXIMIZES BTWN 18Z-00Z TODAY WITH AREA OF STRONGEST LIFT OVR NW WISCONSIN AND THIS CONTINUES INTO TONIGHT. QPF FM VARIOUS MODELS INDICATE THIS WITH MAXIMUM QPF OVR NW WISCONSIN CLOSER TO BETTER ISENTROPIC LIFT AND HIGHEST LOWER LEVEL THETA-E ADVECTION. KEPT POPS MOST AREAS IN THE EVENING AT 20 PCT. EVENTUALLY...APPROACHING PV ANOMALY CURRENTLY BTWN GREAT SLAVE LAKE AND LAKE ATHABASCA IN NORTHWEST CANADA AND UPR DIVERGENCE FM 300MB JET NOSING INTO LK SUPERIOR REGION COMBINE TO INCREASE POPS ALONG THE MOIST AXIS OVR THE WEST HALF OF THE CWA. HIGHEST POPS STAY ALONG WI BORDER DUE TO THE BETTER LOWER LEVEL INFLOW OF MOISTURE. EXPECT FAVORABLE FACTORS OF PVA AND DEEPER MOISTURE TO BECOME OUT OF PHASE BY LATE MON MORNING AS BULK OF SHORTWAVE AND LARGE SCALE LIFT MOVES ACROSS ONTARIO/QUEBEC. RESULT WILL BE THE LINGERING AXIS OF 1.50 INCH PLUS PWATS STRADDLING A LIGHT WIND FIELD...BOTH ALOFT ...AND AT SFC. SFC DEWPOINTS FM NAM/GFS OVR 70 SEEMED A BIT MUCH. ML DEWPOINTS IN THE 60-65 RANGE GIVES CAPE VALUES OVR WESTERN INTERIOR UP TO 1000 J/KG IF TEMPS REACH 80F. LIGHT WINDS AND SOME AFTN SUNSHINE SHOULD PROMOTE LK BREEZES...AT LEAST LOCALLY. CONVERGENCE BTWN LK BREEZES AND A SOUTHERLY SYNOPTIC FLOW MAY TRIGGER CONVECTION. PREVIOUS GRIDS LOOK FINE SHOWING INTERIOR WEST HALF WITH SMALL POPS INTO THE EVENING. ELSEWHERE...CHANCES OF PCPN LOOK MINIMAL AS MARINE STABILIZATION DEVELOPS ALONG WITH NEGATIVE LARGE SCALE FORCING FOR LIFT. CAPPING IN THE H7-H6 LAYER AND A REINFORCEMENT OF RIDGING ALOFT SHOULD END CHANCES OF THE DIURNALLY DRIVEN CONVECTION BY LATE MON EVENING. RIDGING ALOFT MAINTAINS INTO WED. NO SIGNIFICANT SHORTWAVES OR LARGE SCALE FEATURE TO PRODUCE PCPN. INSTEAD...LK BREEZES AND MESOSCALE FEATURES WILL PROVIDE BEST CHANCE OF PCPN IN UNSTABLE ENVIRONMENT. NARROW RIBBON OF ML DEWPOINTS ABOVE 60 INTO THE WESTERN U.P. TUE AFTN RESULTS IN CAPE VALUES NEARING 1000 J/KG. MODIFIED GFS SOUNDINGS INDICATE THAT IF MIXING TO H85 IS ACHIEVED (HIGHS IN THE UPR 80S TO NEAR 90) A PARCEL WOULD BE ABLE TO JUST GET BY THE CAPPING LAYER PRESENT FM H7-H6. ANY SHORTWAVE IN THE NW FLOW ALOFT COULD ALSO TRIGGER A SHOWER OR THUNDERSTORM WITH THE GIVEN INSTABILITY. SIMILAR SETUP FOR WED TOO...ALTHOUGH ML DEWPOINTS ARE DOWN A BIT TO AROUND 60 AND MOISTURE IN SUB H7 LAYER IS LACKING. MODIFIED SOUNDING FOR T/TD OF 85/64 PRODUCED CAPES LESS THAN 500J/KG AND HAD A CIN OVR 50 DUE TO THE MID LEVEL CAPPING. K-INDEX VALUES WERE BLO 20. KEPT ANY PCPN OUT OF FCST NOW. DID INCREASE CLOUDS A BIT WHERE ENHANCED CU FIELD WOULD DEVELOP. OVERALL....POTENTIAL FOR SEVERE WEATHER WITH ANY THUNDERSTORMS LATE TONIGHT INTO TUE LOOKS MINIMAL DUE TO 1-6KM SHEAR VALUES LESS THAN 30 KT. PRIMARY PROBLEM WITH ANY THUNDERSTORMS WILL BE HEAVY RAIN...ESPECIALLY THROUGH MON...AS PWAT VALUES ARE OVR 150 PCT OF NORMAL...K-INDEXES ARE NEAR 40C...AND STORM MOTIONS ARE SMALL AS SEEN IN CORFIDI VECTORS. IN FACT...CORFIDI VECTORS INDICATE POTENTIAL FOR BACKBUILDING BEHAVIOR IN ANY STORMS. DID NOT HIGHLIGHT HEAVY RAIN POTENTIAL IN GRIDS DUE TO OVERALL LOW COVERAGE OF EXPECTED PCPN. WILL MENTION HEAVY RAIN THREAT IN MORNING HWO. BEYOND WED...MEDIUM RANGE GUIDANCE IS STILL TRYING TO SETTLE ON A SOLUTION. OVERALL...GOING FORECAST IS IN FINE SHAPE. LATEST GFS AND ECMWF A BIT MORE BULLISH IN LOWERING HEIGHTS FM THE NORTH AND BRINGING PCPN ACROSS CWA AS EARLY AS THU. GFS HAS BEEN FAIRLY CONSISTENT...BUT ECMWF HAS BEEN STRUGGLING WITH A CONSISTENT SOLUTION IN WHERE TO PLACE THE EASTERN CONUS CUTOFF TROUGH IN THE WED-FRI PERIOD. MEX MOS POPS DID NOT INCREASE TOO MUCH FM PREVIOUS RUNS SO PREFER TO KEEP THU DRY RIGHT NOW AND LET DAYSHIFT ASSESS THIS TIME FRAME FURTHER. COORDINATED WITH APX/GRB/DLH. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... PER 1730Z SATELLITE AND RADAR ANALYSIS...MASS OF CLOUDS...SHOWERS AND THUNDERSTORMS FROM NE MN INTO NW WI CONTINUES TO PRESS EASTWARD INTO THE DRY AIRMASS OVER THE AREA. A FEW ISOLD -SHRA HAVE EVEN DEVELOPED OVER THE FAR WESTERN U.P.. ALL OF THIS PCPN SHOULD SLOWLY MOVE EASTWARD THROUGH TONIGHT...BRINGING CIELING HEIGHTS DOWN INTO THE VFR TO MVFR RANGE. GIVEN THAT THERE IS PLENTY OF MOISTURE FOR THE SHOWERS TO WORK WITH...VISIBILITIES SHOULD DROP TO MVFR...AND POSSIBLY LOWER AS DULUTH EXPERIENCED THIS MORNING. IT APPEARS THAT THE PCPN SHOULD WEAKEN TOMORROW MORNING...THUS NO MENTION OF PCPN IN THE TAF BEYOND 09Z FOR CMX AND THE 11 TO 15Z TEMPO FOR SAW. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... WINDS BELOW 20 KT ARE EXPECTED THROUGH THU. HOWEVER...WINDS MAY APPROACH 20 KT TONIGHT OVER EASTERN LAKE SUPERIOR...DUE TO A SURFACE TROUGH APPROACHING FROM NW ONTARIO AND BUTTING UP AGAINST HIGH PRESSURE NEAR LAKE ERIE. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS/UPDATE/AVIATION...AJ DISCUSSION...JLA MARINE...VOSS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1035 AM EDT SUN JUL 22 2007 .SYNOPSIS... 14Z WATER VAPOR LOOP...12Z RAOBS AND RUC 500MB HEIGHT ANALYSIS SHOWED A 597 DAM HIGH CENTERED OVER WYOMING...WITH TWO WEAK RIDGES EXTENDING OFF OF IT INTO NW NORTH DAKOTA AND TOWARDS LAKE SUPERIOR. BETWEEN THESE RIDGES IS A SHRTWV TROUGH WHICH EXTENDS FROM EASTERN MANITOBA SOUTHWARD INTO EASTERN NORTH DAKOTA. DPVA DOWNSTREAM OF THE SHRTWV...COMBINED WITH ELEVATED INSTABILITY AND STRONG 850MB THETA-E CONVERGENCE HAS SUPPORTED AN AREA OF CLOUDS...SHOWERS AND THUNDERSTORMS. THIS AREA EXTENDS FROM NW ONTARIO INTO NORTHERN MN AND NE SOUTH DAKOTA. MESOANALYSIS USING RUC DATA SHOWS MUCAPE VALUES OF 1000-3000 J/KG WEST OF DLH LIFTED FROM AROUND 850MB. 12Z SOUNDINGS DEPICTED THE MUCAPE AREA AS ALSO HAVING 850MB DEWPOINTS BETWEEN 15-18C (PER CWPL...INL AND MPX SOUNDINGS)...THUS PCPN IN THIS AIRMASS HAS BEEN PRODUCING DECENT RAINFALL RATES AS SHOWN BY KDLH RADAR STORM TOTAL PRECIP GRAPHIC. COMPARE THESE DEWPOINTS TO FARTHER EAST WHERE GRB 850MB DEWPOINT WAS 7C AND APX WAS -3C. TO GIVE AN IDEA OF THE STRONG 850MB THETA-E ADVECTION OCCURRING... BETWEEN 00Z-11Z AT INL...THE PRECIPITABLE WATER JUMPED FROM 0.59 INCHES TO 1.68 INCHES AND THE K-INDEX JUMPED FROM -19 TO 42. OVER OUR CWA...THE AIRMASS HAS SHOWN ABOVE IS MUCH DRIER...THUS THE ONLY CLOUDS THAT HAVE BEEN TRAVERSING THE AREA HAVE BEEN OF THE CIRRUS VARIETY. HOWEVER...CLOUDS FROM MN ARE APPROACHING IWD. DAYTIME MIXING SO FAR HAS ALLOWED READINGS IN MOST AREAS TO REACH THE LOW 70S. && .UPDATE... MAIN CONCERN IS THE TRACK OF THE CONVECTION ACROSS NE MN. FROM OPERATIONAL AND LOCAL WRF-ARW MODELS...NUMEROUS IDEAS ARE PRESENT AS TO WHERE THE CONVECTION ACROSS NE MN WILL GO. 00Z LOCAL WRF-ARW RUN HAD AN EXCELLENT HANDLE WITH THE CONVECTION...AND IT DEPICTS THE PCPN DROPPING DUE SOUTH...FOLLOWING THE CORFIDI VECTORS. THE 06Z GFS AND 00Z CANADIAN DEPICT THE SAME...THOUGH MAINTAIN SOME SHOWERS AND THUNDERSTORMS NORTHWARD ALONG THE SHRTWV TROUGH ACROSS WESTERN LAKE SUPERIOR IN THE AFTERNOON. THE 06Z AND 12Z CYCLES OF THE NAM REALLY DO NOT HAVE A GOOD HANDLE ON THE PCPN... THUS WERE EXCLUDED. HAVE DECIDED TO FOLLOW THE 06Z GFS IDEA FOR A FEW REASONS. FIRST...THE 12Z SOUNDING FROM MPX DEPICTS PLENTY OF ELEVATED INSTABILITY...WHICH COULD BECOME SURFACE BASED IF TEMPS THERE REACHED INTO THE LOW 90S. THEREFORE...WITH CORFIDI VECTORS SUGGESTING A SOUTHWARD MOVEMENT AND THE BEST INSTABILITY TO THE SOUTH...THE BULK OF THE PCPN OVER DLHS AREA SHOULD DROP SOUTH. HOWEVER...BETTER 500MB HEIGHT FALLS AND 850MB THETA-E CONVERGENCE PROGRESS EASTWARD THROUGH THE DAY ASSOCIATED WITH THE SHRTWV TROUGH...THUS AM EXPECTING SOME OF THE SHOWERS AND THUNDERSTORMS OVER DLHS AREA TO ALSO MOVE EAST. GIVEN THIS...HAVE DECIDED TO RAISE POPS TO LIKELY OVER FAR WESTERN LAKE SUPERIOR THIS AFTERNOON AND THE FAR WESTERN U.P. THIS EVENING. AGAIN...WITH HIGH 850MB DEWPOINTS AND PRECIPITABLE WATER MOVING IN...ANY STORM WILL LIKELY PRODUCE HEAVY RAINFALL. FOR THE REST OF THE CWA...DRY AIR ASSOCIATED WITH HIGH PRESSURE IN LOWER MICHIGAN WILL KEEP THE WEATHER QUIET THROUGH EARLY THIS EVENING (OR LONGER IN THE CASE OF THE EASTERN U.P.). WITH ONLY A FEW HIGH CLOUDS MOVING ACROSS...SOUTHERLY WINDS INCREASING AND 850MB TEMPS RISING TO 12C EAST TO 16C WEST BY 18Z...TEMPS SHOULD REACH THE GOING FORECAST HIGHS. && .DISCUSSION (ISSUED AT 458 AM EDT)... UPR LEVEL RIDGE TO THE WEST RE-ORIENTS THROUGH THE DAY IN RESPONSE TO PACKETS OF SHORTWAVE ENERGY SLIDING ALONG US/CANADIAN BORDER. HEIGHT FALLS AT H5 NOT TOO IMPRESSIVE...BUT THERE ARE SOME HEIGHT FALLS AT H85. AS H85 HEIGHTS FALL...WINDS BACK MORE W/SW INTO UPR MISSISSIPPI RIVER VALLEY AND THE DEEP MOISTURE SHOWING UP AS WELL ABOVE NORMAL PWATS OVR DAKOTAS WILL STREAM EAST ACROSS MN INTO FAR WESTERN UPR GREAT LAKES. NAM/GFS ISENTROPIC LIFT ON THE 310K SFC SHOW THIS AS DOES H85 THETA-E PROGS. EXPECT MID LEVEL CLOUDS TO CONTINUE TO SPREAD EAST THIS MORNING INTO WESTERN UPPER MICHIGAN. HOW QUICKLY WILL PCPN BEGIN FALLING FM THIS MID CLOUD DECK IS MAIN QUESTION FOR TODAY. 310K ISENTROPIC LIFT MAXIMIZES BTWN 18Z-00Z TODAY WITH AREA OF STRONGEST LIFT OVR NW WISCONSIN AND THIS CONTINUES INTO TONIGHT. QPF FM VARIOUS MODELS INDICATE THIS WITH MAXIMUM QPF OVR NW WISCONSIN CLOSER TO BETTER ISENTROPIC LIFT AND HIGHEST LOWER LEVEL THETA-E ADVECTION. KEPT POPS MOST AREAS IN THE EVENING AT 20 PCT. EVENTUALLY...APPROACHING PV ANOMALY CURRENTLY BTWN GREAT SLAVE LAKE AND LAKE ATHABASCA IN NORTHWEST CANADA AND UPR DIVERGENCE FM 300MB JET NOSING INTO LK SUPERIOR REGION COMBINE TO INCREASE POPS ALONG THE MOIST AXIS OVR THE WEST HALF OF THE CWA. HIGHEST POPS STAY ALONG WI BORDER DUE TO THE BETTER LOWER LEVEL INFLOW OF MOISTURE. EXPECT FAVORABLE FACTORS OF PVA AND DEEPER MOISTURE TO BECOME OUT OF PHASE BY LATE MON MORNING AS BULK OF SHORTWAVE AND LARGE SCALE LIFT MOVES ACROSS ONTARIO/QUEBEC. RESULT WILL BE THE LINGERING AXIS OF 1.50 INCH PLUS PWATS STRADDLING A LIGHT WIND FIELD...BOTH ALOFT ...AND AT SFC. SFC DEWPOINTS FM NAM/GFS OVR 70 SEEMED A BIT MUCH. ML DEWPOINTS IN THE 60-65 RANGE GIVES CAPE VALUES OVR WESTERN INTERIOR UP TO 1000 J/KG IF TEMPS REACH 80F. LIGHT WINDS AND SOME AFTN SUNSHINE SHOULD PROMOTE LK BREEZES...AT LEAST LOCALLY. CONVERGENCE BTWN LK BREEZES AND A SOUTHERLY SYNOPTIC FLOW MAY TRIGGER CONVECTION. PREVIOUS GRIDS LOOK FINE SHOWING INTERIOR WEST HALF WITH SMALL POPS INTO THE EVENING. ELSEWHERE...CHANCES OF PCPN LOOK MINIMAL AS MARINE STABILIZATION DEVELOPS ALONG WITH NEGATIVE LARGE SCALE FORCING FOR LIFT. CAPPING IN THE H7-H6 LAYER AND A REINFORCEMENT OF RIDGING ALOFT SHOULD END CHANCES OF THE DIURNALLY DRIVEN CONVECTION BY LATE MON EVENING. RIDGING ALOFT MAINTAINS INTO WED. NO SIGNIFICANT SHORTWAVES OR LARGE SCALE FEATURE TO PRODUCE PCPN. INSTEAD...LK BREEZES AND MESOSCALE FEATURES WILL PROVIDE BEST CHANCE OF PCPN IN UNSTABLE ENVIRONMENT. NARROW RIBBON OF ML DEWPOINTS ABOVE 60 INTO THE WESTERN U.P. TUE AFTN RESULTS IN CAPE VALUES NEARING 1000 J/KG. MODIFIED GFS SOUNDINGS INDICATE THAT IF MIXING TO H85 IS ACHIEVED (HIGHS IN THE UPR 80S TO NEAR 90) A PARCEL WOULD BE ABLE TO JUST GET BY THE CAPPING LAYER PRESENT FM H7-H6. ANY SHORTWAVE IN THE NW FLOW ALOFT COULD ALSO TRIGGER A SHOWER OR THUNDERSTORM WITH THE GIVEN INSTABILITY. SIMILAR SETUP FOR WED TOO...ALTHOUGH ML DEWPOINTS ARE DOWN A BIT TO AROUND 60 AND MOISTURE IN SUB H7 LAYER IS LACKING. MODIFIED SOUNDING FOR T/TD OF 85/64 PRODUCED CAPES LESS THAN 500J/KG AND HAD A CIN OVR 50 DUE TO THE MID LEVEL CAPPING. K-INDEX VALUES WERE BLO 20. KEPT ANY PCPN OUT OF FCST NOW. DID INCREASE CLOUDS A BIT WHERE ENHANCED CU FIELD WOULD DEVELOP. OVERALL....POTENTIAL FOR SEVERE WEATHER WITH ANY THUNDERSTORMS LATE TONIGHT INTO TUE LOOKS MINIMAL DUE TO 1-6KM SHEAR VALUES LESS THAN 30 KT. PRIMARY PROBLEM WITH ANY THUNDERSTORMS WILL BE HEAVY RAIN...ESPECIALLY THROUGH MON...AS PWAT VALUES ARE OVR 150 PCT OF NORMAL...K-INDEXES ARE NEAR 40C...AND STORM MOTIONS ARE SMALL AS SEEN IN CORFIDI VECTORS. IN FACT...CORFIDI VECTORS INDICATE POTENTIAL FOR BACKBUILDING BEHAVIOR IN ANY STORMS. DID NOT HIGHLIGHT HEAVY RAIN POTENTIAL IN GRIDS DUE TO OVERALL LOW COVERAGE OF EXPECTED PCPN. WILL MENTION HEAVY RAIN THREAT IN MORNING HWO. BEYOND WED...MEDIUM RANGE GUIDANCE IS STILL TRYING TO SETTLE ON A SOLUTION. OVERALL...GOING FORECAST IS IN FINE SHAPE. LATEST GFS AND ECMWF A BIT MORE BULLISH IN LOWERING HEIGHTS FM THE NORTH AND BRINGING PCPN ACROSS CWA AS EARLY AS THU. GFS HAS BEEN FAIRLY CONSISTENT...BUT ECMWF HAS BEEN STRUGGLING WITH A CONSISTENT SOLUTION IN WHERE TO PLACE THE EASTERN CONUS CUTOFF TROUGH IN THE WED-FRI PERIOD. MEX MOS POPS DID NOT INCREASE TOO MUCH FM PREVIOUS RUNS SO PREFER TO KEEP THU DRY RIGHT NOW AND LET DAYSHIFT ASSESS THIS TIME FRAME FURTHER. COORDINATED WITH APX/GRB/DLH. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... HIGH PRESSURE CENTERED JUST E OF THE FCST AREA AND ITS ASSOCIATED DRY AIR WILL MAINTAIN VFR CONDITIONS THROUGH TODAY. AS THE HIGH MOVES TO THE EAST A BAND OF MOISTURE WILL MOVE TOWARD THE UPPER GREAT LAKES THIS EVENING AND OVERNIGHT. BKN VFR-MVFR CLOUDS ARE EXPECTED. SHOWERS AND THUNDERSTORMS ARE ALSO POSSIBLE THIS EVENING AND OVERNIGHT AS A WARM FRONT APPROACHES THE AREA. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... WINDS BELOW 20 KT ARE EXPECTED THROUGH THU. HOWEVER...WINDS MAY APPROACH 20 KT TONIGHT OVER EASTERN LAKE SUPERIOR...DUE TO A SURFACE TROUGH APPROACHING FROM NW ONTARIO AND BUTTING UP AGAINST HIGH PRESSURE NEAR LAKE ERIE. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS/UPDATE...AJ DISCUSSION...JLA AVIATION/MARINE...VOSS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 845 PM EDT SAT JUL 21 2007 .SYNOPSIS... 19Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED A 594 DAM HIGH SITTING OVER KANSAS...WITH RIDGING PUSHED UP INTO WESTERN HUDSON BAY. THIS RIDGE IS IN-BETWEEN A TROUGH BEGINNING TO SPLIT INTO TWO FROM QUEBEC INTO THE CAROLINAS AND A TROUGH OVER THE NE PACIFIC. ONLY MAIN SHRTWV TO NOTE OF EXTENDS FROM WESTERN SASKATCHEWAN INTO NW MONTANA. VERY WARM AIR EXISTS UNDER AND IMMEDIATELY WEST OF THE RIDGE AXIS...NOTED BY BOTH SURFACE AND 850MB TEMPS. RAPID CITY HAD AN 850MB TEMP AT 12Z OF 23C...AND WITH FULL SUN AND A DOWNSLOPING WIND...TEMPERATURES THERE HAVE RISEN INTO THE LOW 100S. HUMID AIRMASS ALSO EXISTS JUST TO THE EAST OF RAPID CITY...WITH 65-70F DEWPOINTS ADVECTING NORTHWARD ON BREEZY SOUTH WINDS UP INTO CENTRAL MANITOBA. 850MB DEWPOINTS AT 12Z WERE 17C AT ABR AND OMA. A LINE OF CLOUDS NEAR I-29 DELINATES THIS MOIST AIRMASS AND A MUCH DRIER ONE ASSOCIATED WITH HIGH PRESSURE OFF TO THE EAST OVER LAKE MICHIGAN. MPX 850MB DEWPOINT AT 12Z WAS -16C. NONETHELESS...THIS DRY AIRMASS HAS RESULTED IN PLENTY OF SUN OVER THE CWA...AND WITH 850MB TEMPS BETWEEN 10-12C PER 12Z RAOBS... READINGS INLAND HAVE CLIMBED INTO THE 70S AND LOW 80S. THE WEAK PRESSURE GRADIENT ASSOCIATED WITH THE HIGH HAS ALLOWED LAKE BREEZE CIRCULATIONS TO DEVELOP ACROSS THE WESTERN GREAT LAKES...KEEPING SHORELINE AREAS AS MUCH AS 15 DEGREES COOLER. && .SHORT TERM (TONIGHT AND SUN)... UPPER RIDGE IN SOUTH CENTRAL CANADA WILL FLATTEN AND PUSH SE AS THE SHRTWV OVER SASKATCHEWAN MOVES EASTWARD. BY 00Z MON...THIS SHRTWV SHOULD STRETCH FROM NW ONTARIO INTO EASTERN MN PER GFS/UKMET. AS A RESULT...THE SURFACE HIGH CURRENTLY OVER LAKE MICHIGAN WILL BE SHOVED SLOWLY EASTWARD...ALLOWING FOR WARM AND MOIST ADVECTION TO OCCUR ACROSS MN...WI AND THE WESTERN U.P.. PRECIPITABLE WATERS ARE INDICATED TO NEARLY TRIPLE WHAT THEY WERE AT 12Z TODAY. THIS ADVECTION WILL LIKELY RESULT IN SOME STRATUS DECK MOVING INTO THE WESTERN U.P. TOMORROW...SIMILAR TO THE BAND CURRENTLY NEAR I-29. WHETHER OR NOT THIS BAND PRODUCES PCPN IS A BIG QUESTION. THE NAM IS VERY AGGRESSIVE...DEVELOPING PCPN AS EARLY AS 15Z IN IWD...WHICH IS PROBABLY TOO QUICK GIVEN THE DRY AIR IN PLACE. THE GFS HAS SOME LIGHT PCPN BETWEEN 18-00Z...BUT REALLY WAITS UNTIL AFTER 00Z WHEN BETTER PCPN DEVELOPS. THE CANADIAN AND UKMET DO NOT HAVE ANYTHING UNTIL AFTER 00Z MON. THEREFORE...FOR NOW HAVE ONLY DECIDED TO INCLUDE A 20 POP FOR THE FAR WESTERN U.P....WHERE THE THETA-E ADVECTION/CONVERGENCE IS STRONGEST. IN ADDITION...WANT TO HAVE A CHANCE IN JUST IN CASE THE LOW LEVELS END UP WARMING FASTER THAN THE MID-LEVELS...RESULTING IN A CASE FOR DEEP ELEVATED CONVECTION (AS SUGGESTED BY THE GFS NEAR IWD AT 00Z WITH 2000 J/KG OF CAPE LIFTED FROM 800MB). WIDE RANGE OF TEMPERATURES EXPECTED TONIGHT WITH SOUTHWEST WINDS PICKING UP ON THE BACK SIDE OF THE SURFACE HIGH. LOOKS LIKE THE INTERIOR SOUTH CENTRAL AND EAST SHOULD DECOUPLE...AND WITH PRECIPITABLE WATER REMAINING LOW...THOUGH 0.10-0.20 INCH HIGHER THAN LAST NIGHT...WENT CLOSER TO THE 00Z MEX COOP GUIDANCE FOR LOWS INLAND SOUTH CENTRAL AND EAST (43F FOR PARADISE). LAND BREEZES COMBINING WITH THE SW WIND FLOW SHOULD PREVENT MUCH OF THE AREA BORDERING LAKE SUPERIOR FROM FALLING BELOW 60. ON SUNDAY...850MB TEMPS INCREASING TO 12C EAST TO 16C WEST BY 18Z...COMBINED WITH PLENTY OF SUN (THOUGH DIMINISHING IN THE WEST IN THE AFTERNOON)...SHOULD ALLOW READINGS TO CLIMB INTO THE UPPER 70S TO MID 80S. A RELATIVELY BREEZY S TO SW WIND SHOULD KEEP THE LAKE SUPERIOR LAKE BREEZE FROM COMING INLAND...THOUGH AMPLIFY A LAKE MICHIGAN LAKE BREEZE. THUS READINGS IN THE LOW 70S EXPECTED ALONG THE GARDEN PENINSULA AND IN MANISTIQUE. .LONG TERM (SUN NIGHT THROUGH NEXT SAT)... LATEST NAM/GFS HAVE TRENDED FASTER WITH ADVECTING HIER H85 THETA-E/ PWAT AIR (UP TO 2 INCHES OVER THE W BY 12Z MON) INTO THE CWA W-E SUN NGT EXCEPT OVER THE ERN ZNS...WHERE PESKY CUTOFF LO OVER THE MID ATLANTIC WL HOLD HI PRES RDG/DRIER AIR IN PLACE AND MAINTAIN DRY WX THRU THE NGT. BUMPED UP POPS TO HI CHC OVER THE W AND BROUGHT A LO CHC POP AS FAR E AS THE CNTRL ZNS BY MON MRNG. EXPECT A WIDE VARIATION IN LO TEMPS ACRS THE FA WITH DRIER AIR HOLDING IN OVER THE E AND INFLUX OF MSTR OVER THE W. H5 HGT/TEMPS FCST TO RISE ON MON AS UPR RDG AXIS OVER THE W BLDS SLOWLY EWD WHILE SLUGGISH CUTOFF LO REMAINS OVER THE CNTRL APPALACIANS. DEEP LYR H85-3 QVECTOR DVGC/RISING MID LVL TEMPS FCST TO STRENGTHEN CAPPING ABV LLVL MSTR STUCK IN PLACE OVER THE W HALF...BUT DIURNAL HTG SHOULD BE SUFFICIENT TO TRIGGER ADDITIONAL SHRA/TSRA IN THIS AREA...ESPECIALLY SINCE WEAKER PRES GRADIENT WL ALLOW LK BREEZES TO FORM/SERVE AS FOCUS FOR SCT SHRA/TSRA IN THE ABSENCE OF LARGER SCALE DYNAMIC SUPPORT. MODIFIED GFS FCST SDNGS FOR SFC T/TD 83/66 YIELDS LOWEST 100MB MLCAPE UP TO 800 J/KG...BUT WITH SOME CIN UP TO 50-75 J/KG DUE TO INCRSG H8-7 TEMPS. WL GO NO MORE THAN 30 POP OVER THE W HALF. ACRS THE E...GFS/NAM FCST SDNGS SHOW TOO MUCH DRY AIR WL LINGER FOR ANY CHC OF PCPN. PER GFS MOS FOR ERY...HAVE DROPPED POPS COMPLETELY FOR THE E. WITH NO DYNAMIC SUPPORT AND MID LVL DRYING MON NGT...EXPECT ANY DIURNAL SHRA/TSRA TO DIMINISH MON EVNG...GIVING WAY TO A DRY OVERNIGHT. WITH FLAT PRES GRADIENT/LGT WINDS AND LINGERING LLVL MSTR UNDER THE MID LVL DRYING...ADDED PTCHY FOG OVER THE INTERIOR W HALF. ALTHOUGH LLVL MSTR WL LINGER OVER THE W HALF ON TUE...PREFER THE DRIER GFS SCENARIO UNDER UPR RDG AXIS AND MID LVL WARMING/CAPPING IN THE H75-6 LYR. BUT MAINTAINED GOING SCHC POPS OVER THE INTERIOR W HALF WHERE LK BREEZES MAY PROVIDE FOCUS/LINGERING LLVL MSTR IS GREATEST/MODIFIED GFS FCST SDNG FOR IRON RIVER AT 00Z YIELDS LOWEST 100MB MLCAPE UP TO 1600 J/KG AND ONLY -25 J/KG CIN AND KINX TO 35 FOR SFC T/TD OF 83/66. PCPN CHCS OVER THE E REMAIN NEGLIGIBLE WITH LINGERING DRIER AIR IN THE LLVLS. EXCEPT FOR THE 00Z CNDN MODEL...MODEL CONSENSUS NOW IN GOOD AGREEMENT SHOWING UPR RDG WITH H5 TEMPS AS HI AS -4C DOMINATING THE UPR GRT LKS ON WED INTO THU. ECMWF FCSTG H85 TEMPS AS HI AS 22C WHILE GFS A BIT MORE CONSERVATIVE WITH 18-20C DURING THIS PD. WL TEND TOWARD THE HI END OF 00Z GFS MOS GUIDANCE FOR MAX TEMPS FCST WITH A GOOD DEAL OF SUNSHINE AND DRY WX. QUESTIONS THEN LINGER AS TO HOW QUICKLY WESTERLIES OVER CAN WL DIP INTO THE NRN CONUS. MOST OF THE 00Z OPS MODELS WITH SUPPORT FM MAJORITY OF 00Z GFS REFCST ENSEMBLE MEMBERS HAVE TRENDED FASTER TO LOWER HGTS OVER THE UPR LKS AT THE END OF THE WEEK. NCEP MANUAL GUIDANCE SHOWS COLD FROPA ACCOMPANYING THIS MORE WNW FLOW ALF ON FRI...SO HAVE INTRODUCED CHC POPS OVER THE NW COUNTIES LATE THU NGT AND LINGERED POPS INTO SAT OVER THE SRN ZNS...WHERE NCEP GUIDANCE SHOWS FNT MOVING BY AT 12Z ON SAT. COORDINATED WITH GRB/DLH. && .AVIATION (FOR THE 00Z TAF ISSUANCE)... HIGH PRESSURE OVER THE AREA WITH PLENTY OF DRY AIR WILL KEEP SKIES CLEAR INTO SUN MORNING. AS THE HIGH MOVES TO THE EAST AND A BAND OF MOISTURE EDGES TOWARD THE AREA...EXPECT A LINE OF MVFR/VFR CLOUDS CURRENTLY EXTENDING ALONG I-29 TO MOVE INTO THE WEST HALF OF UPPER MICHIGAN LATE SUNDAY AFTERNOON. && .MARINE (FOR 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... WINDS BELOW 20 KT ARE EXPECTED THROUGH THU. HOWEVER...WINDS MAY APPROACH 20 KT SUNDAY NIGHT OVER EASTERN LAKE SUPERIOR...DUE TO A SURFACE TROUGH OVER NW ONTARIO SUNDAY EVENING MOVING SOUTH AND UP AGAINST HIGH PRESSURE NEAR LAKE ERIE. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ AVIATION...JLB SHORT TERM/MARINE...AJ LONG TERM...KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 1148 PM CDT SUN JUL 22 2007 .UPDATE...ADDED AVIATION DISCUSSION FOR 06Z TAFS BELOW && .DISCUSSION... HAVE MADE SOME UPDATES TO THE TONIGHT PORTION OF THE FORECAST. STRONG THUNDERSTORMS...WITH INTENSE RAINFALL AND LIGHTNING RATES...CONTINUE TO REGENERATE ACROSS A PORTION OF WEST CENTRAL WI. TRAINING CELLS ARE OCCURRING ALONG AN AXIS WHERE MPX/ARX VAD WIND PROFILES INDICATE A LOW LEVEL CONVERGENCE SIGNATURE. HAVE INCREASED POPS TO CATEGORICAL ACROSS MUCH OF W CNTRL WI...AND RAISED QPF VALUES IN EXCESS OF 2 INCHES...ESPECIALLY WITH PWATS RUNNING AROUND 200 PERCENT ABOVE NORMAL. ALSO INTRODUCED POPS TO WESTERN MN AFTER 06Z TONIGHT...WITH SUBSTANTIAL INSTABILITY INDICATED ON THE EDGE OF THE THETA E RIDGE. STILL SOME QUESTION AS TO THE STRENGTH OF THE 700MB CAP AND TRIGGERING MECHANISM...ALTHOUGH THE RUC INDICATES SOME EROSION OF THE MID LEVEL WARM LAYER OVERNIGHT...AS A WEAK AREA OF LIFT PASSES ACROSS. ALSO INCREASED DEWPOINTS ACROSS THE WESTERN HALF OF THE CWA...WHERE READINGS HAVE COME UP INTO THE MID/UPPER 70S. WILL LIKELY ALSO NEED TO INCREASE OVERNIGHT LOWS ACROSS WESTERN MN. && .AVIATION.../06Z TAF CYCLE/ AREA OF CEILINGS MOSTLY IN THE 3300-4000 FOOT RANGE WILL CONTINUE EXPANDING ACROSS TAF SITES DURING THE EARLY MORNING HOURS. A FEW SITES MAY TEMPORARILY DIP INTO THE MVFR CATEGORY...MAINLY KEAU/KRNH/KSTC/KMSP. HAVE INCLUDED VCSH FOR ISOLD-WDLY SCT ACTIVITY THAT MAY DEVELOP AS A WEAK DISTURBANCE DROPS SOUTH ACROSS MN/WI OVERNIGHT. SOME LIGHT FOG WILL BE POSSIBLE TOWARD DAYBREAK...WITH CLOUD COVER EXPECTED TO SCATTER OUT MONDAY MORNING ACROSS MN SITES. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ LS mn AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE DULUTH MN 944 PM CDT SUN JUL 22 2007 .UPDATE... UPDATED FIRST PERIOD...MAINLY TO ADJUST POPS DOWNWARD AND DPTS UPWARD...BASED ON CURRENT TRENDS. ALSO INCREASED CLD CVR A BIT AND REMOVED OBSOLETE TIME REFERENCES. && .PREV DISCUSSION... /ISSUED 326 PM CDT SUN JUL 22 2007/ DISCUSSION...QUITE A BATCH OF PRECIPITATION THAT MOVED THROUGH DURING THE MORNING AND FIRST HALF OF THE AFTERNOON. THE MAJORITY OF THE PRECIPITATION HAD MOVED SOUTH OF THE CWA AS OF 3 PM...WITH ONLY A FEW ISOLATED SHOWERS AND STORMS. IN AREAS THAT HAVE STARTED TO SEE SOME SUNSHINE...TEMPS HAVE RISEN QUICKLY...INTO THE 80S IN SPOTS. THE MOST PERSISTENT CLOUD COVER WAS OVER NW WI...ESPECIALLY NEAR THE MCV IN WC WISCONSIN. THE FOCUS FOR TONIGHT WILL BE THE POTENTIAL FOR SEVERE WEATHER. ANY STORMS THIS AFTERNOON HAVE HAD A HARD TIME GETTING GOING... PERHAPS LIMITED BY MID/HIGH CLOUDS AND THE ABILITY TO REACH CONVECTIVE TEMPS NECESSARY FOR SURFACE BASED STORMS TO DEVELOP. RUC INDICATES A SHORTWAVE MOVING SLOWLY ACROSS NRN MN...AND THIS MAY SET OFF A FEW SURFACE BASED STORMS. THE BEST POTENTIAL WOULD BE OVERNIGHT...ONCE THE LOW LEVEL JET AND MASS CONVERGENCE DEVELOPS. LLJ NOT ALL THAT IMPRESSIVE...BUT SHOULD BE ENOUGH TO GENERATE ELEVATED STORMS WITH THE POSSIBILITY OF SOME LARGE HAIL AND DAMAGING WINDS. THE TROUGH WILL MOVE THROUGH OVERNIGHT... POSSIBLY HELPING TO FOCUS ANOTHER MCS OR TWO. GFS AND NAM SEEM TO PICK UP ON THIS AS A RESULT OF THE SHORTWAVE AND THE SURFACE TROUGH. ALSO ADDED PATCHY FOG TO THE ZONES/GRIDS FOR TONIGHT...DUE TO THE HIGH DEWPOINTS AND PRECIPITATION THAT FELL TODAY. THE BEST CHANCE FOR A CONTINUATION OF THUNDERSTORMS ON MONDAY WILL BE FROM EC MN INTO NW WI...CLOSER TO THE TROUGH. CONTEMPLATED PUTTING IN A SMALL POP TUESDAY AFTERNOON AND WEDNESDAY EVENING...BUT THINK THE POTENTIAL IS PRETTY SMALL AT THIS POINT. BETTER CHANCE WILL ARRIVE WEDNESDAY NIGHT IN THE NORTH AND SPREAD SOUTHWARD ON THURSDAY AND THURSDAY NIGHT. FAIRLY WIDESPREAD SHOWERS AND THUNDERSTORMS SHOULD BREAK OUT ALONG THE SOUTHWARD ADVANCING COLD FRONT. THE WEATHER LOOKS PRETTY QUIET AFTER THAT...WITH THE EXCEPTION OF A POSSIBLE STORM OR TWO ON THE WEEKEND. THE WEATHER LOOKS OVERALL PRETTY WARM WITH 90S FOR THE FIRST HALF OF THIS UPCOMING WORK WEEK...AND MAINLY 80S AFTERWARD. AVIATION...EARLIER CONVECTION HAS LEFT SATURATED BDRY LAYER WITH BRIEF IFR/LIFR CONDITIONS AT DLH AND LCL MVFR OVER EXTREME SE CWA. OTHERWISE EXPECT VFR CONDITIONS OVER MOST OF CWA TIL EARLY EVENING. WITH ABUNDANT SOIL MOISTURE/HIGH BDRY LYR RH AND CLEARING THIS EVENING..MAY SEE DROP TO MVFR WITH FG/BR DEVELOPMENT. BUFKIT FOG TECHNIQUE SUGGESTS AFTER 6Z FOG MAY LOWER CONDITIONS TO TEMPO IFR...THROUGH 12Z AS WEAK SFC TROUGH PUSHES ACROSS WN/CTRL CWA. VFR SHOULD RETURN ACROSS THE REGION BY MID MORNING. && POINT TEMPS/POPS... DLH 66 87 62 86 / 50 10 10 10 INL 66 90 62 91 / 10 10 10 10 BRD 68 91 66 92 / 40 10 10 10 HYR 64 88 62 88 / 50 30 10 10 ASX 64 86 60 85 / 50 20 10 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. $$ 04 mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 851 PM CDT SUN JUL 22 2007 .UPDATE...ADDED AVIATION DISCUSSION FOR 00Z TAFS BELOW AND UPDATED PUBLIC DISCUSSION. && .DISCUSSION... HAVE MADE SOME UPDATES TO THE TONIGHT PORTION OF THE FORECAST. STRONG THUNDERSTORMS...WITH INTENSE RAINFALL AND LIGHTNING RATES...CONTINUE TO REGENERATE ACROSS A PORTION OF WEST CENTRAL WI. TRAINING CELLS ARE OCCURRING ALONG AN AXIS WHERE MPX/ARX VAD WIND PROFILES INDICATE A LOW LEVEL CONVERGENCE SIGNATURE. HAVE INCREASED POPS TO CATEGORICAL ACROSS MUCH OF W CNTRL WI...AND RAISED QPF VALUES IN EXCESS OF 2 INCHES...ESPECIALLY WITH PWATS RUNNING AROUND 200 PERCENT OF NORMAL. ALSO INTRODUCED POPS TO WESTERN MN AFTER 06Z TONIGHT...WITH SUBSTANTIAL INSTABILITY INDICATED ON THE EDGE OF THE THETA E RIDGE. STILL SOME QUESTION AS TO THE STRENGTH OF THE 700MB CAP AND TRIGGERING MECHANISM...ALTHOUGH THE RUC INDICATES SOME EROSION OF THE MID LEVEL WARM LAYER OVERNIGHT...AS A WEAK AREA OF LIFT PASSES ACROSS. ALSO INCREASED DEWPOINTS ACROSS THE WESTERN HALF OF THE CWA...WHERE READINGS HAVE COME UP INTO THE MID/UPPER 70S. WILL LIKELY ALSO NEED TO INCREASE OVERNIGHT LOWS ACROSS WESTERN MN. && .AVIATION.../00Z TAF CYCLE/ TS...WITH INTENSE LIGHTNING...WILL CONTINUE TO AFFECT THE KEAU VICINITY THIS EVENING. VERY HEAVY RAINFALL...WITH CEILINGS/VSBYS TANKING INTO THE LIFR CATEGORY...WILL OCCUR WITH THE STRONGER STORMS. ADDITIONAL DEVELOPMENT IS EXPECTED TO AFFECT SITES BACK WESTWARD INTO MN /INCLUDING KRNH...KMSP..KRWF...KSTC/ TONIGHT...AS THE LOW LEVEL JET STRENGTHENS...AND AREA REMAINS ON THE EASTERN EDGE OF THE MID LEVEL CAP. HAVE INCLUDED TEMPO TS/SHRA...MAINLY BETWEEN 07Z AND 12Z. ADDITIONALLY...FOG MAY DEVELOP DUE TO RESIDUAL MOISTURE...ESPECIALLY NEAR KEAU. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ LS/RAH mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 326 PM CDT SUN JUL 22 2007 .DISCUSSION...QUITE A BATCH OF PRECIPITATION THAT MOVED THROUGH DURING THE MORNING AND FIRST HALF OF THE AFTERNOON. THE MAJORITY OF THE PRECIPITATION HAD MOVED SOUTH OF THE CWA AS OF 3 PM...WITH ONLY A FEW ISOLATED SHOWERS AND STORMS. IN AREAS THAT HAVE STARTED TO SEE SOME SUNSHINE...TEMPS HAVE RISEN QUICKLY...INTO THE 80S IN SPOTS. THE MOST PERSISTENT CLOUD COVER WAS OVER NW WI...ESPECIALLY NEAR THE MCV IN WC WISCONSIN. THE FOCUS FOR TONIGHT WILL BE THE POTENTIAL FOR SEVERE WEATHER. ANY STORMS THIS AFTERNOON HAVE HAD A HARD TIME GETTING GOING... PERHAPS LIMITED BY MID/HIGH CLOUDS AND THE ABILITY TO REACH CONVECTIVE TEMPS NECESSARY FOR SURFACE BASED STORMS TO DEVELOP. RUC INDICATES A SHORTWAVE MOVING SLOWLY ACROSS NRN MN...AND THIS MAY SET OFF A FEW SURFACE BASED STORMS. THE BEST POTENTIAL WOULD BE OVERNIGHT...ONCE THE LOW LEVEL JET AND MASS CONVERGENCE DEVELOPS. LLJ NOT ALL THAT IMPRESSIVE...BUT SHOULD BE ENOUGH TO GENERATE ELEVATED STORMS WITH THE POSSIBILITY OF SOME LARGE HAIL AND DAMAGING WINDS. THE TROUGH WILL MOVE THROUGH OVERNIGHT... POSSIBLY HELPING TO FOCUS ANOTHER MCS OR TWO. GFS AND NAM SEEM TO PICK UP ON THIS AS A RESULT OF THE SHORTWAVE AND THE SURFACE TROUGH. ALSO ADDED PATCHY FOG TO THE ZONES/GRIDS FOR TONIGHT...DUE TO THE HIGH DEWPOINTS AND PRECIPITATION THAT FELL TODAY. THE BEST CHANCE FOR A CONTINUATION OF THUNDERSTORMS ON MONDAY WILL BE FROM EC MN INTO NW WI...CLOSER TO THE TROUGH. CONTEMPLATED PUTTING IN A SMALL POP TUESDAY AFTERNOON AND WEDNESDAY EVENING...BUT THINK THE POTENTIAL IS PRETTY SMALL AT THIS POINT. BETTER CHANCE WILL ARRIVE WEDNESDAY NIGHT IN THE NORTH AND SPREAD SOUTHWARD ON THURSDAY AND THURSDAY NIGHT. FAIRLY WIDESPREAD SHOWERS AND THUNDERSTORMS SHOULD BREAK OUT ALONG THE SOUTHWARD ADVANCING COLD FRONT. THE WEATHER LOOKS PRETTY QUIET AFTER THAT...WITH THE EXCEPTION OF A POSSIBLE STORM OR TWO ON THE WEEKEND. THE WEATHER LOOKS OVERALL PRETTY WARM WITH 90S FOR THE FIRST HALF OF THIS UPCOMING WORK WEEK...AND MAINLY 80S AFTERWARD. && .AVIATION...EARLIER CONVECTION HAS LEFT SATURATED BDRY LAYER WITH BRIEF IFR/LIFR CONDITIONS AT DLH AND LCL MVFR OVER EXTREME SE CWA. OTHERWISE EXPECT VFR CONDITIONS OVER MOST OF CWA TIL EARLY EVENING. WITH ABUNDANT SOIL MOISTURE/HIGH BDRY LYR RH AND CLEARING THIS EVENING..MAY SEE DROP TO MVFR WITH FG/BR DEVELOPMENT. BUFKIT FOG TECHNIQUE SUGGESTS AFTER 6Z FOG MAY LOWER CONDITIONS TO TEMPO IFR...THROUGH 12Z AS WEAK SFC TROUGH PUSHES ACROSS WN/CTRL CWA. VFR SHOULD RETURN ACROSS THE REGION BY MID MORNING. && POINT TEMPS/POPS... DLH 62 87 62 86 / 50 10 10 10 INL 62 90 62 91 / 10 10 10 10 BRD 64 91 66 92 / 40 10 10 10 HYR 62 88 62 88 / 50 30 10 10 ASX 61 86 60 85 / 50 20 10 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. $$ DAP/CANNON mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 641 PM CDT MON JUL 23 2007 .DISCUSSION... COMBO OF UPPER RIDGE FROM THE CENTRAL ROCKIES THROUGH MN AND CUTOFF LOW OVER VA WOBBLING WESTWARD WILL PROVIDE A NORTHEAST UPPER FLOW OVER THE CENTRAL U.S. FOR ANOTHER COUPLE DAYS. WHILE IN THE BOUNDARY LAYER A SURFACE RIDGE FORM THE EASTERN GREAT LAKES THROUGH MO MAINTAINS A CONTINUED SOUTHEASTERLY FETCH OF ABNORMALLY DRY AIR INTO THE SOUTHEAST HALF OF THE CWA. THIS WILL RESULT IN SLIGHTLY BELOW NORMAL MAX TEMPERATURES...EXCEPT FOR THE NORTHWEST CORNER OF MO...FOR THE NEXT COUPLE OF DAYS AND BELOW NORMAL DEWPOINTS FOR THE SOUTHEAST HALF. IN THE NEAR TERM THE MORNING MCS WEAKENED AS IT MOVED INTO EASTERN KS. SUBSIDENCE IN THE WAKE OF THE MCS TEMPORARILY SUPPRESSED EARLY AFTERNOON CONVECTION. HOWEVER...POCKETS OF INSTABILITY FORMED LATE THIS AFTERNOON IN BETWEEN THE RESIDUAL ACCAS WHICH HAS RECENTLY THICKENED. WATER VAPOR IMAGERY SHOWS WHAT IS LEFT OF THE VORTICITY CENTER OVER CENTRAL MO AND SPINNING WESTWARD. LATEST DOPPLER RADAR SHOWS ISOLATED CELLS HAVE POPPED UP FROM KC METRO SOUTHWARD AND THIS SUPPORTS THE LATEST NAM/RUC QPF THROUGH 00Z TONIGHT. DONT THINK WE WILL SEE MORE THAN ISOLATED OR WIDELY SCATTERED CONVECTION SO WILL LEAVE LOW CHANCE POPS FOR FAR WESTERN CWA FOR A FEW MORE HOURS. HAVE INSERTED PATCHY FOG OVER NORTHERN AND WESTERN CWA FOR LATE TONIGHT DUE TO TODAYS HEAVY RAINS AND LIGHT SOUTHEASTERLY WINDS UNDER A DEVELOPING INVERSION. LACKING ANY DISCERNIBLE UPSTREAM SHORTWAVE TOPPING THE UPPER RIDGE NOR AN IMMEDIATE SURFACE BOUNDARY RISK OF CONVECTION NEXT COUPLE OF DAYS IS BELOW SLIGHT CHANCE CATEGORY. WITH THE VA CUTOFF LOW EDGING WESTWARD WHILE THE SURFACE RIDGE REMAINS IN PLACE FAVOR SLIGHTLY COOLER NAM 850MB TEMPERATURES WHICH IMPLIES MID-UPPER 80S FOR MOST AREAS NEXT 2 DAYS. FAR NORTHWEST MO WILL FLIRT WITH 90. WOULD HAVE GONE WITH THE COOLER MET MOS EXCEPT THINKING THERE WOULD BE A GRADUAL 1 OR 2 DEGREE WARMUP PER DAY AS THE AIRMASS SLOWLY MODIFIES. MJ EXTENDED DISCUSSION (THURSDAY THROUGH MONDAY)... LAST HALF OF THE FORECAST...THURSDAY THROUGH NEXT MONDAY...WILL SEE THE DISTINCTLY ODD UPPER LEVEL PATTERN OF THE EARLY WORK WEEK MORPH INTO SOMETHING A LITTLE MORE NORMAL FOR THIS TIME OF YEAR. IN GENERAL... THE MID RANGE MODELS ARE IN AGREEMENT. NAMELY THAT A SHORTWAVE... CURRENTLY MAKING LANDFALL ACROSS BRITISH COLUMBIA...WILL TOP THE RIDGE THAT DOMINATES THE WEST HALF OF THE CONUS AND THEN ABSORB THE CUTOFF LOW INTO A WEEK EAST CONUS TROUGH. THIS WILL TURN THE ODD NORTHEASTERLY FLOW ALOFT INTO MORE OF A SEASONALLY APPROPRIATE DIRTY NORTHWEST FLOW BY FRIDAY ACROSS THE CENTRAL PLAINS. WITH THE ONSET OF THE NORTHWEST FLOW WILL COME THE ARRIVAL OF THE TRAILING EDGE OF THE SHORTWAVE THAT HELPED CHANGE THE PATTERN. THIS SHORTWAVE WILL BRING WITH IT A WEAK SURFACE FRONT. AS EXPECTED...THE MIDRANGE MODELS ALL DIFFER ON THE PRECISE TIMING OF THE FRONT AND SHORTWAVE...BUT WITH AT LEAST A GENERAL CONSENSUS THAT THE WAVE AND FRONT WILL BE THERE I HAVE GONE AHEAD AND ADDED CHANCE POPS TO THE AFTERNOON AND OVERNIGHT HOURS OF FRIDAY. AS FOR THE REST OF THE SHORTWAVES IN THE FLOW THROUGH MONDAY...THEY ARE ALL CURRENTLY PROGGED TO STAY WELL NORTH OF THE CENTRAL PLAINS. THEREFORE I HAVE LEFT THE OUTER PERIODS DRY AT THIS TIME. TEMPERATURES BEHIND THE FRONT SATURDAY LOOK TO TAKE A LITTLE DIP...BUT H85 TEMPERATURES ARE PROGGED TO REBOUND THROUGH THE REST OF THE WEEKEND. HAVE MADE MINOR ADJUSTMENTS TO TEMPERATURE TRENDS TO REFLECT THIS. CUTTER && .AVIATION... AXIS OF BROKEN MVFR CEILINGS EXTENDING ACROSS THE TERMINALS WILL STEADILY DISSIPATE OVER THE NEXT COUPLE HOURS WITH THE LOSS OF DAYTIME HEATING. WAVERING MOISTURE GRADIENT HAS ONCE AGAIN EASED EAST OF THE TERMINALS...WITH DEWPOINTS NOW BACK TO AROUND 70F. SO DESPITE SE WINDS OVERNIGHT...CONTRIBUTION FROM RAINFALL THIS MORNING SHOULD ALLOW AT LEAST LIGHT FOG TO DEVELOP ACROSS THE TERMINALS BEFORE DAYBREAK. LOW LYING AREAS...ESPECIALLY AROUND KSTJ TERMINAL...SHOULD TOUCH IFR CONDITIONS. BOOKBINDER && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. $$ mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 140 PM CDT SUN JUL 22 2007 ...UPDATED FOR AVIATION DISCUSSION... .DISCUSSION... ELIMINATED THE MORNING ISOLATED SHOWERS FROM NORTHWEST MO AS THEY HAVE FAILED TO MATERIALIZE AND THE LATEST SATELLITE IMAGERY SHOWS THE CLOUD COVER IS THICKENING UP JUST WEST OF THIS AREA ANYWAY. ALSO LOWERED HOURLY DEWPOINTS IN THE GRIDDED DATA AS CURRENT DEWPOINTS RUNNING 3-5 DEGREES LOWER THAN CURRENTLY FORECAST AND ONLY EXPECT MODEST INCREASES TODAY. WILL ALSO EVALUATE THE 12Z MODEL RUNS CONCERNING ALL THE CLOUDINESS THEY HAVE BEEN FORECASTING FOR THE WESTERN CWA FOR TODAY. LATEST SATELLITE IMAGERY SUGGESTS IT MAY NOT BE AS DENSE AS FORECAST BY THE MODELS. MJ && .PREV DISCUSSION... /500 AM CDT SUN JUL 22 2007/ LARGE SCALE UPPER RIDGE AXIS REMAINS ENTRENCHED ACROSS WESTERN CONUS EARLY THIS MORNING. IMPULSE CURRENTLY OVERTOPPING RIDGE AXIS MAY ENHANCE WEAK ISENTROPIC LIFT ACROSS NORTHERN PORTIONS OF FORECAST AREA...AS DEPICTED BY NAM/RUC...TO SPAWN ISOLATED SHOWERS THIS MORNING. OVERALL...EXPECT SENSIBLE WEATHER TODAY TO BE SIMILAR TO CONDITIONS EXPERIENCED ON SATURDAY. NAM/RUC SHOWING SLIGHT INCREASE IN H8 AND H9 TEMPERATURES...WHICH COUPLED WITH WEAK SOUTHERLY WINDS...SHOULD ALLOW TEMPERATURES TO BE A COUPLE DEGREES WARMER TODAY. SOUTHERLY FLOW WILL HELP DEWPOINTS INCREASE ACROSS WESTERN PART OF CWA...WHILE DRIER AIRMASS WILL CONTINUE TO AFFECT EASTERN PART OF FORECAST AREA. CONSEQUENTLY...EXPECT TO SEE GREATER DIURNAL RANGES ACROSS EAST TONIGHT AND LEANED TOWARD COOLER MET NUMBERS IN THESE AREAS...WHILE MET/MAV BLEND USED FURTHER WEST. NAM/GFS CONSISTENT IN DROPPING COMPACT SHORTWAVE SOUTHWARD INTO MISSOURI LATE TONIGHT INTO EARLY MONDAY. RIDGE TOPPING SHORTWAVE APPEARS TO SYNC WITH SHEAR AXIS EMANATING FROM EASTERN U.S. UPPER LOW ...WHICH IN TURN WILL DRAG DIFFUSE FRONTAL BOUNDARY INTO NORTHERN PORTIONS OF CWA BY EARLY MONDAY. COUPLING OF SHORTWAVE AND SHEAR AXIS WITH WEAK ISENTROPIC FORCING AND INCREASING BOUNDARY LAYER MOIST FLUX AGAIN WILL BRING THREAT OF ISOLATED TO SCATTERED CONVECTION TO PORTIONS OF FORECAST AREA. CURRENT THINKING IS THAT CONVECTION WILL REMAIN MOSTLY ELEVATED AS CONVERGENCE ALONG SURFACE BOUNDARY VERY WEAK...WHICH SHOULD MITIGATE SEVERE THREAT. H5 SHEAR AXIS LINGERS ACROSS FORECAST AREA MONDAY NIGHT INTO TUESDAY. FOCUS OF ANY CONVECTIVE DEVELOP SHOULD SHIFT GENERALLY SOUTH OF MISSOURI RIVER ON TUESDAY...WITH NORTHERN PORTIONS OF FORECAST AREA REMAINING ON THE ANTICYCLONIC SIDE OF H5 SHEAR AXIS. CONFIDENCE IS LOW ON EXACT ORIENTATION OF SHEAR AXIS THUS...DECIDED TO CARRY ONLY SLIGHT CHANCE POPS FOR NOW. A LITTLE CONCERNED ABOUT TEMPERATURES ON TUESDAY...AS EXPECT THERE WILL BE A FAIRLY PERSISTENT ALTOCU DECK ASSOCIATED WITH SHEAR AXIS. DECIDED TO TWEAK TEMPERATURES SLIGHTLY DOWNWARD BASED ON THIS THINKING. 24 && .AVIATION... FOR THE 18Z TAF VFR CEILINGS THROUGH THIS AFTERNOON WITH CLOUDS SCATTERING OUT TONIGHT. MID CLOUDS INCREASING TOWARDS 12Z MONDAY WITH CEILINGS AOA 5K FEET. CONVECTION SHOULD STAY NORTH OF MCI AND MKC BUT SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE BY LATE MORNING AT STJ WITH TEMPORARY MVFR CEILINGS WITH STORMS. MJ && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. $$ mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 905 AM CDT SUN JUL 22 2007 .DISCUSSION... ELIMINATED THE MORNING ISOLATED SHOWERS FROM NORTHWEST MO AS THEY HAVE FAILED TO MATERIALIZE AND THE LATEST SATELLITE IMAGERY SHOWS THE CLOUD COVER IS THICKENING UP JUST WEST OF THIS AREA ANYWAY. ALSO LOWERED HOURLY DEWPOINTS IN THE GRIDDED DATA AS CURRENT DEWPOINTS RUNNING 3-5 DEGREES LOWER THAN CURRENTLY FORECAST AND ONLY EXPECT MODEST INCREASES TODAY. WILL ALSO EVALUATE THE 12Z MODEL RUNS CONCERNING ALL THE CLOUDINESS THEY HAVE BEEN FORECASTING FOR THE WESTERN CWA FOR TODAY. LATEST SATELLITE IMAGERY SUGGESTS IT MAY NOT BE AS DENSE AS FORECAST BY THE MODELS. MJ && .PREV DISCUSSION... /500 AM CDT SUN JUL 22 2007/ LARGE SCALE UPPER RIDGE AXIS REMAINS ENTRENCHED ACROSS WESTERN CONUS EARLY THIS MORNING. IMPULSE CURRENTLY OVERTOPPING RIDGE AXIS MAY ENHANCE WEAK ISENTROPIC LIFT ACROSS NORTHERN PORTIONS OF FORECAST AREA...AS DEPICTED BY NAM/RUC...TO SPAWN ISOLATED SHOWERS THIS MORNING. OVERALL...EXPECT SENSIBLE WEATHER TODAY TO BE SIMILAR TO CONDITIONS EXPERIENCED ON SATURDAY. NAM/RUC SHOWING SLIGHT INCREASE IN H8 AND H9 TEMPERATURES...WHICH COUPLED WITH WEAK SOUTHERLY WINDS...SHOULD ALLOW TEMPERATURES TO BE A COUPLE DEGREES WARMER TODAY. SOUTHERLY FLOW WILL HELP DEWPOINTS INCREASE ACROSS WESTERN PART OF CWA...WHILE DRIER AIRMASS WILL CONTINUE TO AFFECT EASTERN PART OF FORECAST AREA. CONSEQUENTLY...EXPECT TO SEE GREATER DIURNAL RANGES ACROSS EAST TONIGHT AND LEANED TOWARD COOLER MET NUMBERS IN THESE AREAS...WHILE MET/MAV BLEND USED FURTHER WEST. NAM/GFS CONSISTENT IN DROPPING COMPACT SHORTWAVE SOUTHWARD INTO MISSOURI LATE TONIGHT INTO EARLY MONDAY. RIDGE TOPPING SHORTWAVE APPEARS TO SYNC WITH SHEAR AXIS EMANATING FROM EASTERN U.S. UPPER LOW ...WHICH IN TURN WILL DRAG DIFFUSE FRONTAL BOUNDARY INTO NORTHERN PORTIONS OF CWA BY EARLY MONDAY. COUPLING OF SHORTWAVE AND SHEAR AXIS WITH WEAK ISENTROPIC FORCING AND INCREASING BOUNDARY LAYER MOIST FLUX AGAIN WILL BRING THREAT OF ISOLATED TO SCATTERED CONVECTION TO PORTIONS OF FORECAST AREA. CURRENT THINKING IS THAT CONVECTION WILL REMAIN MOSTLY ELEVATED AS CONVERGENCE ALONG SURFACE BOUNDARY VERY WEAK...WHICH SHOULD MITIGATE SEVERE THREAT. H5 SHEAR AXIS LINGERS ACROSS FORECAST AREA MONDAY NIGHT INTO TUESDAY. FOCUS OF ANY CONVECTIVE DEVELOP SHOULD SHIFT GENERALLY SOUTH OF MISSOURI RIVER ON TUESDAY...WITH NORTHERN PORTIONS OF FORECAST AREA REMAINING ON THE ANTICYCLONIC SIDE OF H5 SHEAR AXIS. CONFIDENCE IS LOW ON EXACT ORIENTATION OF SHEAR AXIS THUS...DECIDED TO CARRY ONLY SLIGHT CHANCE POPS FOR NOW. A LITTLE CONCERNED ABOUT TEMPERATURES ON TUESDAY...AS EXPECT THERE WILL BE A FAIRLY PERSISTENT ALTOCU DECK ASSOCIATED WITH SHEAR AXIS. DECIDED TO TWEAK TEMPERATURES SLIGHTLY DOWNWARD BASED ON THIS THINKING. 24 && .AVIATION... /729 PM CDT SAT JUL 21 2007/ FOR THE 00Z TAF CYCLE...SCATTERED OUT MID LEVEL CLOUDS FOR THE EVENING AND OVERNIGHT PERIOD. THE SHOWERS AROUND THE STJ SITE HAVE DISSIPATED. KEPT WITH PREVIOUS FORECAST CYCLE AND EXPECT CLOUDS TO BE ON THE INCREASE SHORTLY BEFORE 12Z SUNDAY. VFR CONDITIONS WILL CONTINUE TO PREVAIL. THE POSSIBILITY FOR ISOLATED SHOWERS WILL ALSO BE ON THE INCREASE AFTER ABOUT 10Z SUNDAY OWING TO INCREASING ISENTROPIC LIFT. MRD && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. $$ mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 500 AM CDT SUN JUL 22 2007 .DISCUSSION... LARGE SCALE UPPER RIDGE AXIS REMAINS ENTRENCHED ACROSS WESTERN CONUS EARLY THIS MORNING. IMPULSE CURRENTLY OVERTOPPING RIDGE AXIS MAY ENHANCE WEAK ISENTROPIC LIFT ACROSS NORTHERN PORTIONS OF FORECAST AREA...AS DEPICTED BY NAM/RUC...TO SPAWN ISOLATED SHOWERS THIS MORNING. OVERALL...EXPECT SENSIBLE WEATHER TODAY TO BE SIMILAR TO CONDITIONS EXPERIENCED ON SATURDAY. NAM/RUC SHOWING SLIGHT INCREASE IN H8 AND H9 TEMPERATURES...WHICH COUPLED WITH WEAK SOUTHERLY WINDS...SHOULD ALLOW TEMPERATURES TO BE A COUPLE DEGREES WARMER TODAY. SOUTHERLY FLOW WILL HELP DEWPOINTS INCREASE ACROSS WESTERN PART OF CWA...WHILE DRIER AIRMASS WILL CONTINUE TO AFFECT EASTERN PART OF FORECAST AREA. CONSEQUENTLY...EXPECT TO SEE GREATER DIURNAL RANGES ACROSS EAST TONIGHT AND LEANED TOWARD COOLER MET NUMBERS IN THESE AREAS...WHILE MET/MAV BLEND USED FURTHER WEST. NAM/GFS CONSISTENT IN DROPPING COMPACT SHORTWAVE SOUTHWARD INTO MISSOURI LATE TONIGHT INTO EARLY MONDAY. RIDGE TOPPING SHORTWAVE APPEARS TO SYNC WITH SHEAR AXIS EMNATING FROM EASTERN U.S. UPPER LOW ...WHICH IN TURN WILL DRAG DIFFUSE FRONTAL BOUNDARY INTO NORTHERN PORTIONS OF CWA BY EARLY MONDAY. COUPLING OF SHORTWAVE AND SHEAR AXIS WITH WEAK ISENTROPIC FORCING AND INCREASING BOUNDARY LAYER MOIST FLUX AGAIN WILL BRING THREAT OF ISOLATED TO SCATTERED CONVECTION TO PORTIONS OF FORECAST AREA. CURRENT THINKING IS THAT CONVECTION WILL REMAIN MOSTLY ELEVATED AS CONVERGENCE ALONG SURFACE BOUNDARY VERY WEAK...WHICH SHOULD MITIGATE SEVERE THREAT. H5 SHEAR AXIS LINGERS ACROSS FORECAST AREA MONDAY NIGHT INTO TUESDAY. FOCUS OF ANY CONVECTIVE DEVELOP SHOULD SHIFT GENERALLY SOUTH OF MISSOURI RIVER ON TUESDAY...WITH NORTHERN PORTIONS OF FORECAST AREA REMAINING ON THE ANTICYCLONIC SIDE OF H5 SHEAR AXIS. CONFIDENCE IS LOW ON EXACT ORIENTATION OF SHEAR AXIS THUS...DECIDED TO CARRY ONLY SLIGHT CHANCE POPS FOR NOW. A LITTLE CONCERNED ABOUT TEMPERATURES ON TUESDAY...AS EXPECT THERE WILL BE A FAIRLY PERSISTENT ALTOCU DECK ASSOCIATED WITH SHEAR AXIS. DECIDED TO TWEAK TEMPERATURES SLIGHTLY DOWNWARD BASED ON THIS THINKING. 24 && .AVIATION... /729 PM CDT SAT JUL 21 2007/ FOR THE 00Z TAF CYCLE...SCATTERED OUT MID LEVEL CLOUDS FOR THE EVENING AND OVERNIGHT PERIOD. THE SHOWERS AROUND THE STJ SITE HAVE DISSIPATED. KEPT WITH PREVIOUS FORECAST CYCLE AND EXPECT CLOUDS TO BE ON THE INCREASE SHORTLY BEFORE 12Z SUNDAY. VFR CONDITIONS WILL CONTINUE TO PREVAIL. THE POSSIBILITY FOR ISOLATED SHOWERS WILL ALSO BE ON THE INCREASE AFTER ABOUT 10Z SUNDAY OWING TO INCREASING ISENTROPIC LIFT. MRD && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. $$ mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HASTINGS NE 1248 AM CDT SUN JUL 22 2007 .AVIATION...06Z TAF...CONCERN FOR THIS ISSUANCE LOOKS TO BE WHETHER OR NOT WE GET AND STRATUS BEFORE SUNRISE. 0Z UPPER AIR DATA SHOWED BEST LOW LEVEL MOISTURE IN EASTERN NEBRASKA AND KANSAS AND PROFILERS SHOWING WINDS AT THAT LEVEL MAINLY OUT OF THE SOUTH. COULD GET SOME STRATUS IN EASTERN PART OF CWA BUT DO NOT EXPECT IT TO MAKE IT AS FAR AS GRI. SEVERAL MODELS GOING ALONG THIS LINE WHEN LOOKING AT CONDENSATION PRESSURE DEFICITS. WINDS SHOULD KEEP UP TONIGHT AND NOT EXPECTING ANY VSBY PROBLEMS. SOME AFTERNOON CU SHOULD POP SIMILAR TO PAST FEW DAYS. && .PREV DISCUSSION... /ISSUED 958 PM CDT SAT JUL 21 2007/ DISCUSSION...QUICK UPDATE FOR END OF RAIN CHANCES...ALTHOUGH THERE IS A STUBBORN THUNDERSHOWER IN THE TOP CWA...I EXPECT THIS CELL TO DIE BEFORE IT HAS THE CHANCE TO GIVE US ANY PROBLEMS. PREV DISCUSSION... /ISSUED 240 PM CDT SAT JUL 21 2007/ SHORT TERM...TONIGHT THROUGH 12Z MONDAY. MAIN PROBLEM SURROUNDS RAIN CHANCES. AFTERNOON SURFACE ANALYSIS PLACED A SUBTLE/WEAK BOUNDARY ACROSS CENTRAL KANSAS. WEAK FORCING ASSOCIATED WITH THIS...COMBINED WITH AMPLE LOW LEVEL MOISTURE HAS LED TO THE DEVELOPMENT OF ISOLATED SHOWERS ACROSS PORTIONS OF CENTRAL KANSAS. THE 12Z GFS/LATEST RUC AND 09Z SREF ALL SUGGEST THAT A FEW SHOWERS AND PERHAPS A THUNDERSTORM ARE POSSIBLE FURTHER NORTH INTO SOUTH CENTRAL NEBRASKA IN THE MOISTURE/INSTABILITY AXIS. WILL EXPAND THE CHANCE FOR ISOLATED SHOWERS FARTHER NORTH BASED ON THIS...BUT END THEM BY MID EVENING. LOW LEVEL MOISTURE REMAINS IN PLACE TONIGHT...WITH THE 12Z NAM AND GFS BOTH SUGGESTING THAT THE FAVORED LOCATION FOR STRATUS FORMATION WILL BE ACROSS EASTERN NEBRASKA WHICH COULD IMPACT MAINLY EASTERN SECTIONS OF THE FORECAST AREA. WILL INCREASE CLOUDS IN THE EAST LATE TONIGHT AND EARLY SUNDAY MORNING TO ACCOUNT FOR THE POSSIBILITY OF STRATUS. LOWS TONIGHT WILL BE AROUND 70 IN MOST SPOTS. IT IS A TOUGH CALL ON RAIN CHANCES FOR SUNDAY WITH THE MOISTURE/INSTABILITY AXIS STILL ACROSS EASTERN PORTIONS OF THE FORECAST AREA. THERE SHOULD BE LITTLE IN THE WAY OF LOW LEVEL FORCING MECHANISMS...HOWEVER THE 12Z NAM AND GFS BOTH SUGGEST THERE COULD BE A WEAK UPPER WAVE MOVING ACROSS CENTRAL NEBRASKA. THE 09Z SREF ALSO INCREASES THE RAIN CHANCES ACROSS THE EASTERN HALF OF THE FORECAST AREA IN THE AFTERNOON/EVENING...SO WILL CONTINUE TO CARRY A SLIGHT CHANCE POP. HAVE GONE FOR HIGHS IN THE LOWER TO MID 90S ON SUNDAY...WITH LOWS SUNDAY NIGHT AGAIN AROUND 70. LONG TERM...12Z MONDAY THROUGH SATURDAY. ANOTHER RIDGE RIDER COMES THROUGH THE AREA MONDAY AFTERNOON AND EVENING. THIS WILL BRING A SLIGHT CHANCE FOR THUNDERSTORMS TO THE EASTERN PORTION OF THE FORECAST AREA...MAINLY EAST OF HIGHWAY 281. AFTER THAT...RIDGE BUILDS IN FAIRLY WELL UNTIL NEXT WAVE MAKES IT INTO THE AREA ON FRIDAY. THIS WAVE AND THE RETROGRADING UPPER LOW MOVING WEST ACROSS THE OHIO VALLEY WILL BRING ANOTHER FRONT THROUGH THE REGION. THIS WILL BRING A CHANCE FOR THUNDERSTORMS FROM FRIDAY EVENING INTO SATURDAY. STILL TOO EARLY TO ADD ANY DEFINITION TO AREA AND TIMING AND WILL KEEP POPS IN THE SLIGHT CHANCE CATEGORY. AFTERNOON TEMPS TO BE NORMAL FOR MID-JULY WITH READINGS IN THE 90 TO 95 DEGREE RANGE. IT WILL BE A LITTLE COOLER ON SATURDAY AS CLOUDS/PRECIP AND FRONT PASSAGE WILL KEEP TEMPS IN THE UPPER 80S TO LOWER 90S. OVERNIGHT LOWS ARE TO BE IN THE MIDDLE 60S TO LOWER 70S. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 730 PM PDT SUN JUL 22 2007 .SYNOPSIS...AN INCREASINGLY DEEP MOIST SOUTHEAST FLOW WILL SPREAD UP THROUGH THE ENTIRE REGION MONDAY AND TUESDAY BRINGING MORE EXTENSIVE THUNDERSTORM COVERAGE WITH SIGNIFICANT RAINFALL. MOISTURE WILL LINGER ACROSS THE REGION THROUGH THE WEEK FOR SCATTERED AFTERNOON AND EVENING THUNDERSTORMS EACH DAY. && .UPDATE...STORMS HAVE GREATLY DIMINISHED IN SIZE AND INTENSITY OVER THE PAST COUPLE OF HOURS. NEW MODEL DATA COMING IN ALONG WITH SATELLITE ANALYSIS DOES NOT INDICATE A STRONG ENOUGH WAVE TO CAUSE NEW STORM DEVELOPMENT OVER NEVADA. SOME INDICATION FROM THE RUC OF A WAVE THAT WILL GO THROUGH SAN BERNARDINO COUNTY TONIGHT SO KEPT SLIGHTLY HIGHER POPS GOING THERE. WILL ISSUE AN ADDITIONAL GRID UPDATE LATER IF NEEDED. && .PREVIOUS DISCUSSION...330 PM PDT...SHORT TERM...THUNDERSTORMS IN THE FORECAST AREA WERE CONFINED MAINLY TO MOHAVE COUNTY AS OF 22Z BUT MID LEVEL EAST TO NORTHEAST FLOW WAS PUSHING CONVECTION TO THE SOUTHWEST. CLARK AND EASTERN SAN BERNARDINO COUNTIES WERE GETTING MORE SUNSHINE THIS AFTERNOON AS THE CLOUD SHIELD MIXED OUT AND THIS SHOULD HELP DESTABILIZE THE ATMOSPHERE SOMEWHAT. THE MAIN FEATURES TO WATCH ARE THE CIRCULATION ALONG THE NORTHERN CENTRAL ARIZONA/UTAH BORDER AND THE BROADER WAVE OVER CENTRAL AND SOUTHERN ARIZONA. THE 18Z NAM AND GFS BOTH DETECT THESE FEATURES AND MOVE THE CENTRAL ARIZONA WAVE UP INTO NORTHWEST ARIZONA AND SOUTHERN NEVADA BETWEEN 06Z AND 12Z. CONVECTION APPEARED TO BE DEVELOPING ALONG THE LEADING EDGE OF THIS AND IT MAY PROVIDE ENHANCEMENT INTO SOUTHERN NEVADA THROUGH THIS EVENING AND POSSIBLY KEEP ISOLATED STORMS GOING OVERNIGHT. RAINFALL RATES IN MOHAVE COUNTY HAVE BEEN FAIRLY IMPRESSIVE WITH GAGES RECORDING UP TO 1.75 INCHES PER HOUR. THIS WAS ALSO CLOSE TO RADAR ESTIMATES. THE SOUTHEAST FLOW PERSISTS AND TRANSPORTS DEEPER MOISTURE ACROSS THE ENTIRE CWA MONDAY INTO TUESDAY. THE GFS INDICATES A 30 MB SOUTHERLY JET MOVING ACROSS SOUTHERN CALIFORNIA AND SOUTHERN NEVADA EARLY TUESDAY AND THE MODELS INDICATE VARIOUS DISTURBANCES EMBEDDED IN THE FLOW. IT APPEARS TUESDAY HAS A BETTER POTENTIAL FOR MORE EXTENSIVE THUNDERSTORM COVERAGE AND THE PREVIOUS FORECAST REFLECTED THIS TREND. HEAVY RAIN WORDING WAS ADDED ACROSS THE AREA MOHAVE COUNTY AND THE AREA SOUTH OF I-40 THIS EVENING...SOUTHEAST OF I-15 MONDAY THEN ACROSS THE SOUTHERN TWO-THIRDS OF THE FORECAST AREA FOR TUESDAY. .LONG TERM...MONSOONAL MOISTURE WILL REMAIN IN PLACE OVER THE AREA THROUGH THE LONG TERM WITH THE DEEPEST MOISTURE RESIDING IN THE SOUTHERN HALF OF THE FORECAST AREA. HIGH PRESSURE ALOFT IS FORECAST TO PROGRESSIVELY BUILD BACK OVER THE REGION. THIS SHOULD ALLOW FOR A CONTINUOUS RECYCLING OF MOISTURE EACH DAY AND THE POSSIBILITY OF THUNDERSTORMS. MADE LITTLE CHANGE IN THE POP/WX GRIDS WITH NO DISCERNIBLE FEATURES EVIDENT IN THE MODEL DATA THAT WOULD PROVIDE A FOCUS FOR STORMS AND HEAVY RAIN. THUS...EXPECT THAT STORMS WILL BE OF THE SCATTERED VARIETY BUT WILL CARRY THE POTENTIAL FOR PRODUCING HEAVY RAIN IN A SHORT PERIOD OF TIME. THIS COULD LEAD TO FLASH FLOODING PROBLEMS...ESPECIALLY IN AREAS THAT ARE PRONE TO FLASH FLOODING. IN GENERAL...TEMPERATURES SHOULD BE NEAR NORMAL LEVELS BUT WILL BE HIGHLY DEPENDENT ON AMOUNT OF CLOUD COVER OVER THE AREA AND ALSO WHEN AND WHERE SHOWERS DEVELOP EACH DAY. && .AVIATION...FOR MCCARRAN...CLOUD COVER HAS LIMITED THUNDERSTORM DEVELOPMENT THUS FAR TO PORTIONS OF SOUTHERN MOHAVE COUNTY AND SOUTHWEST UTAH. HOWEVER...STORMS ARE NOW DEVELOPING BETWEEN THESE TWO AREAS AND WILL BE IMPACTING BOTH THE MORMON MESA AND PEACH SPRINGS APPROACH CORRIDORS THROUGH THE REMAINDER OF THE AFTERNOON AND INTO THE EVENING. THUNDERSTORMS ARE STILL POSSIBLE LATER THIS AFTERNOON OVER THE SPRING MOUNTAINS AND SHEEP RANGE BUT THERE WILL BE A BETTER CHANCE FOR STORMS OVER THE MOUNTAINS AND IN THE LAS VEGAS VALLEY MONDAY THROUGH WEDNESDAY. THUNDERSTORMS WILL LIKELY IMPACT ALL APPROACH CORRIDORS TOMORROW THROUGH WEDNESDAY WITH THE GREATEST COVERAGE EXPECTED ACROSS THE PEACH SPRINGS AND MORMON MESA CORRIDORS. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...THUNDERSTORM CHANCES WILL REMAIN MAINLY OVER THE EASTERN PORTIONS OF THE AREA THROUGH THE REST OF TODAY BUT WILL INCREASE IN COVERAGE AND SPREAD WEST MONDAY THROUGH WEDNESDAY. MAIN IMPACT FOR WINDS OVER THE NEXT SEVERAL DAYS WILL BE THUNDERSTORM OUTFLOW. && .VEF WATCHES/WARNINGS/ADVISORIES... .NV...NONE. .AZ...NONE. .CA...NONE. && $$ BELL/ADAIR/SALMEN HTTP://WEATHER.GOV/LASVEGAS nv AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 1104 AM EDT MON JUL 23 2007 .SYNOPSIS... LOW PRES OFF THE COAST WILL MOVE N TODAY. WEAK HIGH PRES WILL BUILD OVER THE AREA TONIGHT...THEN MOVE OFFSHORE TUE AND WED. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPR LOW OVER NW NC AND SFC LOW OFF NRN COAST WILL BOTH MOVE N TODAY...LEAVING WEAK SFC RIDGING OVER ERN NC. RESULT WILL BE TOLERABLE TEMPS AND RH FOR LATE JULY. RAIN HAS ENDED ALONG NORTHERN OBX BUT CU FIELD HAS SET UP IN EARNEST. WILL REMOVE POPS FROM OBX FORECAST FOR TODAY. NO OTHER CHANGES NEEDED ATTM. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/... MODELS AGREE ON UPR LOW CONTINUING TO RETROGRADE TO NW DURING PERIOD. WEAK SFC RIDGE WILL BUILD OVER AREA TONIGHT...THEN MOVE OFFSHORE REST OF PERIOD. DRY CONDITIONS CONTINUE TONIGHT AND EARLY TUE...THEN INCREASING MSTR EXPECTED LATE TUE THROUGH WED AS UPR LOW TAPS GULF WHILE OLD FRONTAL BOUNDARY MOVES BACK IN ON RETURN SELY FLOW AT SFC. SLIGHT CHC POPS LIMITED TO COASTAL PLAIN TUE AFTN...THEN ALL ZONES TUE NIGHT. CHC POPS ALL AREAS WED. TEMPS NEAR NORMAL TUE...THEN A FEW DEGS COOLER WED WITH INCREASING MSTR AND MORE CLOUDS. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... MODELS FINALLY COMING INTO AGREEMENT WITH HANDLING OF UPPER LOW ACROSS THE EAST. THE CUTOFF LOW CONTINUE OVER THE GREAT LAKES REGION WED NIGHT BUT GET ABSORBED INTO THE FLOW ALOFT AS A SHORTWAVE TROUGH DIGS SWD ACROSS CANADA. AN UPPER TROUGH CONTINUES ACROSS THE EAST THROUGH THE LONG TERM HOWEVER WITH MOIST S-SWLY FLOW ACROSS THE REGION WITH HIGH PRES OVER THE WRN ATLANTIC. THE COMBINATION OF PERTURBATIONS MOVING THROUGH THE UPPER TROF...MOIST ONSHORE FLOW...DIURNAL HEATING AND SFC SEABREEZE AND THERMAL BOUNDARIES WILL PRODUCE SCATTERED CONVECTION ACROSS THE REGION EACH DAY AND HAVE CHANCE POPS THROUGH THE LONG TERM. WITH LOWER HEIGHTS ACROSS THE REGION AND INCREASED CLOUD COVER ACROSS THE REGION MAX TEMPS ARE EXPECTED TO AVERAGE A LITTLE BELOW NORMAL. && .AVIATION /149Z MONDAY THROUGH FRIDAY/... VFR CONDS WILL CONT THRU TONIGHT WITH LGT TO MOD SFC FLOW. EXPECT CU DVLPMT THIS AFTN IN THE 4-6K FT RANGE. CUD SEE SOME SCT VFR CIGS. && .MARINE... WILL KEEP MARGINAL SCA N OF OCRACOKE THRU THE AFTN BUT WILL LWR SEAS BY 1 FT NRN LEG TO 5 TO 7 FT N OF OREGON INLET AND 4-6 FT S. RUC MODEL SHOWS WINDS SHUD CONT TO DMNSH DURG THE AFTN AS SFC LOW OFF THE DELMARVA GRDLY MOVES AWAY TO THE NE...ALLOWING FOR THE PRES GRAD TO FURTHER RELAX. .RIP CURRENTS... N WINDS 15-20 KT THIS MORNING WITH 3 TO 4 FT WAVES IN THE SURF ZONE WILL CREATE A HIGH RISK OF RIP CURRENTS FROM CAPE HAT N TODAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS AFTERNOON FOR AMZ150- 152-154. && $$ SYNOPSIS...TK NEAR TERM...TK SHORT TERM...TK LONG TERM...TK AVIATION...JAC MARINE...JAC nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TULSA OK 850 PM CDT SUN JUL 22 2007 .DISCUSSION... CONVECTION WHICH INITIATED DURING AFTERNOON HEATING HAS DIMINISHED QUICKLY WITHIN THE LAST HOUR WITH STABILIZING BOUNDARY LAYER. THIS DRYING TREND WILL LIKELY HOLD FOR THE MAJORITY OF THE OVERNIGHT HOURS...HOWEVER WATER VAPOR IMAGERY SUGGESTS A WEAK IMPULSE CURRENTLY DROPPING SOUTHWARD INTO NORTHERN KANSAS WHICH TRACKS BACKWARD TO CONVECTION YESTERDAY EVENING ACROSS WESTERN NEBRASKA. THUNDERSTORMS CONTINUE TO DEVELOP DOWNSTREAM OF THIS FEATURE...AND WHILE BULK OF ANY OVERNIGHT ACTIVITY WILL LIKELY REMAIN TO OUR NORTH...THIS WAVE CONTINUING SOUTHWARD ALONG WITH THE RUC DEPICTION OF THE ELEVATED INSTABILITY AXIS AND ORIENTATION OF MEAN DEEP LAYER WIND FIELDS SUPPORT A SLIGHT CHANCE OF PRECIP ACROSS NORTHWESTERN PORTIONS OF THE FORECAST AREA LATE TONIGHT. OTHERWISE...24HR CHANGE PLOTS SHOW NOTICEABLY DRIER AIR MAKING IT INTO WESTERN ARKANSAS. THIS TREND...WHICH REMAINED ABSENT SATURDAY NIGHT...WILL CONTINUE AND SUPPORTS FORECAST LOW TEMPS. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ SHORT TERM...03 LONG TERM....07 ok AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 815 PM CDT SUN JUL 22 2007 MAIN ISSUE OVERNIGHT IS WHETHER OR NOT TO CONTINUE WITH ANY CHANCE OF THUNDERSTORMS. 25-35 KNOT 400-500 MB SPEED MAX ON THE EASTERN PERIPHERY OF THE COLORADO UPPER HIGH HELPED SUPPORT ROTATING UPDRAFTS WITH A FEW STORMS EARLIER EAST OF INTERSTATE 35. THERE REMAINS AMPLE MOISTURE AND INSTABILITY AS WELL FOR MORE STORMS OVERNIGHT WITH 00Z REGIONAL RAOBS SUPPORTING MIXED LAYER CAPES BETWEEN 1500-2000 J/KG ALONG WITH LOW CONVECTIVE INHIBITION...MAINLY ALONG AND EAST OF INTERSTATE 35 WHERE A WEAKENING OUTFLOW BOUNDARY AND WEAK STATIONARY FRONT EXIST. WITH CONVECTIVELY INDUCED OR CONVECTIVELY-AMPLIFIED PERTURBATIONS POSSIBLY REMAINING IN UPPER LEVEL SPEED MAX REGION THAT EXTENDS INTO NORTHERN KANSAS WHERE THUNDERSTORMS CONTINUE TO DEVELOP...AND A VEERING PROFILE LIKELY FORMING IN THE LOWER/MID LEVELS LATER TONIGHT...ESPECIALLY OVER NORTHERN OKLAHOMA...THINK IT IS BEST TO CONTINUE WITH AT LEAST ISOLATED CHANCES OF THUNDERSTORMS EAST OF A LINE FROM WICHITA FALLS TO WEATHERFORD AND CHEROKEE. OTHERWISE...THE FRONT OVER EASTERN OKLAHOMA IS SHOWN BY THE RUC/NAM TO DRIFT SLIGHTLY WESTWARD BY MORNING WITH A MORE CONTINENTAL AIRMASS AFFECTING EASTERN OKLAHOMA ON MONDAY. JAMES ------------------------- 240 PM CDT SUN JUL 22 2007 .DISCUSSION...A FEW SHOWERS AND TSTMS HAVE DEVELOPED THIS AFTERNOON OVER FAR EASTERN PORTIONS OF THE FA...ALTHOUGH COVERAGE IS NOT AS GREAT AS YESTERDAY AFTN. AXIS OF BETTER INSTABILITY REMAINS FROM AROUND PNC SWD TO VICINITY OF ADM/DUA BUT CONVERGENCE ALONG WEAKENING SFC BNDRY APPEARS WEAKER THAN YESTERDAY. HOWEVER WITH SOME ECHOES DEVELOPING EARLY THIS AFTN WILL CONTINUE WITH LOW POPS THIS THROUGH EARLY EVENING FOR EASTERN HALF OF THE FA. THINK ACTIVITY SHOULD DIE FAIRLY QUICKLY AFTER SUNSET. MOIST AXIS EXPECTED TO SHIFT EVEN FRTHR WWD ON MONDAY AS SFC RDG PUSHES INTO WRN AR/ERN OK. WILL SHIFT POPS WWD ACCORDINGLY. WITH UPPER RIDGE BUILDING INTO THE NRN ROCKIES/PLAINS AND LOW PERSISTING OVER THE ERN U.S. NELY FLOW DEVELOPS OVER THE AREA WITH WEAK IMPULSES MOVING THROUGH. WILL CONTINUE WITH LOW POPS THROUGH TUESDAY. UPPER TROUGH AXIS GENLY REMAINS SE OF THE FA THROUGH MUCH OF THE REMAINDER OF THE WEEK WITH RDG PERSISTING TO THE NW. THUS WILL KEEP FORECAST DRY THROUGH FRIDAY NIGHT. GFS AND ECMWF SHOW A WEAK FRONT MOVING INTO THE FA OVER THE WEEKEND ALTHOUGH THERE ARE TIMING DIFFERENCES. WITH FRONT MOVING IN WILL ADD SOME LOW POPS TO THE WEEKEND FCST. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 72 92 70 91 / 20 20 20 20 HOBART OK 72 92 71 91 / 10 20 20 20 WICHITA FALLS TX 72 93 72 92 / 20 20 20 20 GAGE OK 69 92 69 91 / 10 20 20 20 PONCA CITY OK 73 92 72 90 / 20 20 20 20 DURANT OK 68 92 68 91 / 20 10 10 20 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 23/02 ok AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 358 AM EDT MON JUL 23 2007 .SYNOPSIS... A SHIELD OF MID AND HIGH CLOUDS WILL MOVE NORTHWEST FROM THE MID ATLANTIC COAST AND OVERSPREAD THE REGION DURING THE MID TO LATE MORNING HOURS TODAY. THE CLOUDS WILL LOWER AND THICKEN UP THIS AFTERNOON WHICH WILL ALLOW FREQUENT SHOWERS TO DEVELOP ACROSS THE SUSQUEHANNA VALLEY AND POINTS EAST. THE SHOWERS WILL BE MORE SCATTERED ACROSS THE CENTRAL AND NORTHWEST MOUNTAINS...AND LIMITED TO THE AFTERNOON AND EVENING HOURS. THE AREA OF LOW PRESSURE THAT WAS CAUSING THIS BOUT OF CLOUDS AND SHOWERS WILL BE LOCATED A FEW HUNDRED MILES EAST OF NORFOLK VIRGINIA EARLY TODAY AND WILL MOVE NORTH TO REACH THE SOUTHERN NEW ENGLAND COAST TONIGHT. DRIER AIR WILL COMFORTABLE TEMPERATURES /NEAR TO SLIGHTLY BELOW NORMAL/ AND HUMIDITY WILL RETURN FOR TUESDAY AND WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... NAM APPEARS TO BE THE MORE BELIEVABLE OPERATIONAL MODEL EARLY TODAY AS ITS RESOLVES MESOSCALE UPPER JET SEGMENTS AND THEIR ASSOCIATED DYNAMIC LIFT MUCH BETTER THAN THE GFS WHICH LOSES THE DISTINCT BRANCHES OF UVVEL/SHOWERS IN ITS COARSER GRID STRUCTURE/SMOOTHING. INITIAL UPPER SHORT WAVE AND LIFT WHICH WAS CENTERED WITHIN THE 300-310K LAYER WILL SPREAD A THICK SHIELD OF CIRRUS AND ALTO STRATUS CLOUDS NNWD ACROSS THE CWA EARLY TODAY...AND EVEN A FEW HOURS EARLIER THAN THE 00Z NAM INDICATES. NAM/S 290-300K CONDENSATION DEFICIT IS AOB 20MB ACROSS THE ECENT MTNS...PARTS OF THE MID SUSQ VALLEY AND NORTH CENTRAL PENN...WHICH MEANS THAT THE CLOUDS WILL LOWER AND THICKEN...SUPPORTING SHOWERS /INITIALLY EVAPORATING IN AND SIGNIFICANTLY COOLING/ THE RELATIVELY DRY BOUNDARY LAYER. CONSIDERING THE THICK CLOUD COVER AND LIKELY POPS...HAVE PAINTED TEMPS TODAY CLOSE TO THE COOLER NAM/FWC MOS NUMBERS /ESPECIALLY ACROSS THE EASTERN PART OF THE CWA/ WHERE THE DIFF BETWEEN THE GFS IS 5-8F. THE NOSE OF A E/NE 40-45KT 850 HPA CURLS SWWD AND ACROSS THE NCENT PENN LATE TODAY/THIS EVENING WHICH SHOULD SUPPORT THE FURTHEST WWD PUSH IN THE PRECIP SHIELD AS THE LOW TRACKS UP THE NJ COAST. OUR CURRENT QPF AND POP GRIDS COULD BE A BIT UNDERDONE /ESP ACROSS OUR FAR ERN ZONES/ SHOULD THE NAM VERIFY...SINCE IT SHOWS STORM TOTAL RAINFALL OF ONE HALF TO ONE INCH THERE BY 09Z TUESDAY. GFS IS NEARLY NON-EXISTENT WITH RAINFALL OVER PRACTICALLY THE ENTIRE CWA THIS SAME PERIOD...SUGGESTING PERHAPS ONE TENTH OF AN INCH FALLING CLOSER TO THE COLD POOL ALOFT ACROSS THE LAUREL HIGHLANDS. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... PARTIAL CLEARING WILL OCCUR FROM SOUTHEAST TO NORTHWEST LATE TONIGHT AND TUESDAY AS WEAK RIDGING/ISENT DOWN GLIDE DEVELOPS BETWEEN THE EXITING/DISSIPATING LOW OVER THE NEW ENGLAND STATES...AND THE PERSISTENT CUTOFF LOW THAT WILL BE MEANDERING THROUGH MUCH OF THIS WEEK ACROSS THE CENTRAL OHIO RIVER VALLEY. 12 HOUR POPS WILL AVERAGE ABOUT 30 PERCENT DURING THIS PERIOD WITH THE TYPICAL WEIGHTING TOWARD THE THE LATE AFTERNOON HOURS. DEEP LAYER MOISTURE WILL ADVECT NORTHWARD LATER TUESDAY AND WEDNESDAY TO THE EAST OF THE UPPER LOW CENTER...WITH BOTH GFS AND NAM DEPICTING AT LEAST A WEAK LLJ LIFTING UP THE MID ATLANTIC COASTLINE AND LAYER PWATS INCREASING OVER 1.5" WITH THAT FEATURE. THIS COULD BRING MORE MEANINGFUL AND MUCH NEEDED RAINFALL TO SOUTHEAST PA...BUT SPECIFIC DETAILS EVEN THIS FAR OUT REMAIN SKETCHY AND INSTABILITY WILL BE LACKING WITHOUT SOME BINOVC OVER EASTERN PA...WILL DEPEND UPON SHORTWAVE FEATURES THAN CANNOT BE RESOLVED AT THIS TIME. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... A CUTOFF UPPER LOW WILL OPEN UP INTO A BROAD TROUGH OVER THE LOWER LAKES BY MIDWEEK. THIS WILL ALLOW MOISTURE TO BE DRAWN NORTH FROM THE SOUTHEAST ATLANTIC COAST. THIS WILL ALLOW FOR JUST SCATTERED SHOWERS AND DIURNALLY DRIVEN CONVECTION THROUGH THE END OF THE FORECAST PERIOD. IT WILL NOT BE RAINING ALL OF THE TIME BUT SCATTERED ACTIVITY NONETHELESS. WILL KEEP THE IDEA OF TEMPS COOLEST IN THE FIRST PART OF THE WEEK...THEN RISING THROUGH THE WEEK...AS THE LOW SHOULD EITHER MOVE AWAY OR GO WEST AND BOTH WILL ALLOW HEIGHTS OVERHEAD TO RISE. THE SFC PATTERN FRI/SAT LOOKS TO BE RATHER BERMUDA-HIGH- LIKE. SO...THIS COULD MAKE IT MUGGY AND HOT. WILL HAVE TO WAIT AND SEE HOW THE UPPER LOW PLAYS OUT. && .AVIATION /07Z MONDAY THROUGH FRIDAY/... IR SATELLITE LOOP SHOWS BKN-OVC CI SHIELD /WITH SOME PATCHY MID LVL AC/ ASSOC WITH MOISTURE PLUME ALOFT STREAMING NNWWD ACROSS THE DELMARVA AND INTO CENTRAL PA AHEAD OF RELATIVELY WEAK SFC LOW TRACKING UP THE MID ATLANTIC COAST. LATEST RUC ANALYSIS SHOWS A SLIGHT WWD JOG WITH RESPECT TO THE SFC LOW TRACK WITH THE CENTER OF THE LOW LOCATED APPROX 280-300 MILES EAST OF ORF. MODELS AND SUBSEQUENT MOS GUID STILL HAVING SOME PROBLEMS RESOLVING DETAILS PERTAINING TO THE OVERALL LARGE SCALE PATTERN AND COINCIDING SFC FEATURES...WHICH FOR THIS TIME OF YEAR ARE RATHER ANOMALOUS AND GO AGAINST CLIMO - WHICH IS WEIGHTED HEAVILY IN THE MOS. NEVERTHELESS...EXPECT VFR CONDITIONS WITH INC CLOUDS FROM SE-NW FOR THE CRITICAL TAF PD. LOW LEVELS STILL RATHER DRY WITH SFC DEWPOINTS IN THE 40S/50S. MID AND HIGH CLDS WILL GRADUALLY LOWER AND THICKEN THRU THE DAY ACROSS THE REGION. THE PRIMARY AVN CONCERN WILL BE LOWER SUSQ VLY /MDT/ WHERE FWC GUID SUGGESTS MVFR CONDS FROM BASICALLY MID MORNING ON. WITH A RATHER DEEP ELY FETCH DRAWING IN PLENTY OF ATL MOISTURE...LOWER CLOUDS CERTAINLY NOT OUT OF THE QUESTION AND HAVE HEDGED THAT WAY WITH A PROB GROUP. REGIONAL RADAR MOSAIC ALREADY DEPICTING RETURNS ALOFT ALL THE WAY INTO SRN NJ. WILL CONTINUE TO MONITOR TRENDS ACROSS THIS AREA AND MAY NEED TO HIT THINGS A LITTLE HARDER WITH THE 12Z ISSUANCE. ELSEWHERE...HAVE KEPT CIGS MAINLY AOA 10KFT...BUT AGAIN MAY NEED TO LOWER THESE NEXT GO- AROUND ESP AT KIPT. SFC WNDS LGT AND VRB FOR NOW...BCMG NNELY 5-8KTS AFTER SUNRISE. CLOSED UPPER LEVEL LOW APPEARS TO RETROGRADE WWD IN TIME THRU THE WEEK BACK INTO THE UPR OH VLY...THEN EVENTUALLY GETS PICKED UP BY THE WESTERLIES AND LIFTS OUT TOWARD THE WEEKEND. ALTHOUGH PROBABILITIES REMAIN LOW GIVEN NATURE OF THE COVERAGE...ALMOST DAILY CHCS FOR SCT AFTN CONVECTION WILL BE THE RULE FOR MUCH OF THE WORK WEEK AS LLVL MOISTURE INC. HOWEVER...VFR CONDS WILL STILL BE THE DOMINATE FLIGHT CAT. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...DEVOIR/LAMBERT LONG TERM...DANGELO/TYBURSKI AVIATION...STEINBUGL pa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 219 AM EDT MON JUL 23 2007 .SYNOPSIS... CLEAR SKIES EARLY TONIGHT WILL BE FOLLOWED BY A BLANKET OF CLOUD COVER SPREADING NORTHWEST ACROSS THE REGION MONDAY MORNING AS LOW PRESSURE SLIDES NORTHWARD ALONG THE MID ATLANTIC COAST. AS THE CLOUDS THICKEN UP MONDAY MORNING AND AFTERNOON...SHOWERS WILL REACH CENTRAL AND EASTERN SECTIONS OF THE STATE...WITH SCATTERED SHOWERS DEVELOPING OVER THE WESTERN MOUNTAINS LATER IN THE DAY. PLENTY OF CLOUDS AND SCATTERED SHOWERS WILL REMAIN ACROSS THE COMMONWEALTH MONDAY NIGHT AND TUESDAY. WARMER AND MORE HUMID AIR WILL RETURN DURING THE SECOND HALF OF THE UPCOMING WEEK...WITH A CHANCE OF AN AFTERNOON SHOWER OR THUNDERSTORM WEDNESDAY THROUGH FRIDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... BROKEN HIGH CLOUD SHIELD STREAMING NORTHWARD INTO CENTRAL PA THIS EVENING AHEAD OF CUTOFF LOW CIRCULATION OVER THE CENTRAL APPALACHIANS. ALL RECENT MODEL DATA SUGGESTS A SIGNIFICANT AMT OF HIGH CLOUDINESS OVERNIGHT...AS UPPER LVL SE FLOW DRAWS CONVECTIVE DEBRIS FROM MID ATLANTIC COAST NORTHWESTWARD. THE INCREASED CLOUD COVER SHOULD KEEP TEMPS A FEW DEG MILDER THAN RECENT NIGHTS AND PRECLUDE VALLEY FOG FORMATION. HAVE REMOVED MENTION OF SHWRS OVR THE LOWER SUSQ VALLEY LATE TONIGHT...AS LATEST SREF AND OPER GFS/NAM KEEP IT DRY UNTIL AT LEAST 12Z. && .SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/... TRICKY FORECAST FOR MONDAY...AS SLIGHTLY ANOMALOUS EASTERLY FLOW AROUND MID ATLANTIC COASTAL WAVE DIRECTS HIGHER PWAT AIR TOWARDS NEW JERSEY AND EASTERN PENNSYLVANIA. 18Z NAM TRENDING TOWARD A MORE EASTERLY TRACK OF THIS FEATURE...CLOSER TO THAT OF THE GFS...SO WILL TREND POPS DOWNWARD A BIT ON MONDAY. A LATE DAY SHWR/TSTM APPEARS POSSIBLE AS FAR WEST AS THE LAUREL HIGHLANDS...AS DIURNAL HEATING CREATES MARGINALLY UNSTABLE SOUNDINGS IN VICINITY OF APPROACHING UPPER LOW CENTER. GIVEN THE DRIER FCST...HAVE ALSO RAISED MAX TEMPS A BIT FOR MONDAY. THE COOLER NAM SOUNDINGS SUGGEST HIGHS MAINLY IN THE M/U 70S...SOME 5 TO 10F BELOW NORMAL. MREFS/SREFS DRAMATICALLY DAMPEN COASTAL WAVE IN TIME SO THAT BY TUESDAY NO DISCERNIBLE 850 MB CIRCULATION IS APPARENT...BOWING TO BROAD SOUTHERLY FLOW AT 500 MB EAST OF THE RETROGRESSING UPPER LOW CENTER HAVE BACKED OFF QPF BASIN AVG RAINFALL AMOUNTS FROM PREVIOUS FORECASTS GIVEN DAMPENING OF JET FEATURE DEPICTED BY MREF/SREF... BUT ADMITTEDLY THE MREF/SREF PLUMES DEPICT A BIMODAL SCENARIO WITH EITHER WET OR DRY SOLUTIONS...AND ABOUT A 60/40 SPLIT OF DRY/WET MEMBERS. DEEP LAYER MOISTURE TO ADVECT NORTHWARD LATER TUESDAY AND WEDNESDAY TO THE EAST OF THE UPPER LOW CENTER...WITH BOTH GFS AND NAM DEPICTING AT LEAST A WEAK LLJ LIFTING UP THE MID ATLANTIC COASTLINE AND LAYER PWATS INCREASING OVER 1.5" WITH THAT FEATURE. THIS COULD BRING MORE MEANINGFUL AND MUCH NEEDED RAINFALL TO SOUTHEAST PA...BUT SPECIFIC DETAILS EVEN THIS FAR OUT REMAIN SKETCHY AND INSTABILITY WILL BE LACKING WITHOUT SOME BINOVC OVER EASTERN PA...WILL DEPEND UPON SHORTWAVE FEATURES THAN CANNOT BE RESOLVED AT THIS TIME. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... A CUTOFF UPPER LOW WILL OPEN UP INTO A BROAD TROUGH OVER THE LOWER LAKES BY MIDWEEK. THIS WILL ALLOW MOISTURE TO BE DRAWN NORTH FROM THE SOUTHEAST ATLANTIC COAST. THIS WILL ALLOW FOR JUST SCATTERED SHOWERS AND DIURNALLY DRIVEN CONVECTION THROUGH THE END OF THE FORECAST PERIOD. IT WILL NOT BE RAINING ALL OF THE TIME BUT SCATTERED ACTIVITY NONETHELESS. WILL KEEP THE IDEA OF TEMPS COOLEST IN THE FIRST PART OF THE WEEK...THEN RISING THROUGH THE WEEK...AS THE LOW SHOULD EITHER MOVE AWAY OR GO WEST AND BOTH WILL ALLOW HEIGHTS OVERHEAD TO RISE. THE SFC PATTERN FRI/SAT LOOKS TO BE RATHER BERMUDA-HIGH- LIKE. SO...THIS COULD MAKE IT MUGGY AND HOT. WILL HAVE TO WAIT AND SEE HOW THE UPPER LOW PLAYS OUT. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... IR SATELLITE LOOP SHOWS BKN-OVC CI SHIELD /WITH SOME PATCHY MID LVL AC/ ASSOC WITH MOISTURE PLUME ALOFT STREAMING NNWWD ACROSS THE DELMARVA AND INTO CENTRAL PA AHEAD OF RELATIVELY WEAK SFC LOW TRACKING UP THE MID ATLANTIC COAST. LATEST RUC ANALYSIS SHOWS A SLIGHT WWD JOG WITH RESPECT TO THE SFC LOW TRACK WITH THE CENTER OF THE LOW LOCATED APPROX 280-300 MILES EAST OF ORF. MODELS AND SUBSEQUENT MOS GUID STILL HAVING SOME PROBLEMS RESOLVING DETAILS PERTAINING TO THE OVERALL LARGE SCALE PATTERN AND COINCIDING SFC FEATURES...WHICH FOR THIS TIME OF YEAR ARE RATHER ANOMALOUS AND GO AGAINST CLIMO - WHICH IS WEIGHTED HEAVILY IN THE MOS. NEVERTHELESS...EXPECT VFR CONDITIONS WITH INC CLOUDS FROM SE-NW FOR THE CRITICAL TAF PD. LOW LEVELS STILL RATHER DRY WITH SFC DEWPOINTS IN THE 40S/50S. MID AND HIGH CLDS WILL GRADUALLY LOWER AND THICKEN THRU THE DAY ACROSS THE REGION. THE PRIMARY AVN CONCERN WILL BE LOWER SUSQ VLY /MDT/ WHERE FWC GUID SUGGESTS MVFR CONDS FROM BASICALLY MID MORNING ON. WITH A RATHER DEEP ELY FETCH DRAWING IN PLENTY OF ATL MOISTURE...LOWER CLOUDS CERTAINLY NOT OUT OF THE QUESTION AND HAVE HEDGED THAT WAY WITH A PROB GROUP. REGIONAL RADAR MOSAIC ALREADY DEPICTING RETURNS ALOFT ALL THE WAY INTO SRN NJ. WILL CONTINUE TO MONITOR TRENDS ACROSS THIS AREA AND MAY NEED TO HIT THINGS A LITTLE HARDER WITH THE 12Z ISSUANCE. ELSEWHERE...HAVE KEPT CIGS MAINLY AOA 10KFT...BUT AGAIN MAY NEED TO LOWER THESE NEXT GO- AROUND ESP AT KIPT. SFC WNDS LGT AND VRB FOR NOW...BCMG NNELY 5-8KTS AFTER SUNRISE. CLOSED UPPER LEVEL LOW APPEARS TO RETROGRADE WWD IN TIME THRU THE WEEK BACK INTO THE UPR OH VLY...THEN EVENTUALLY GETS PICKED UP BY THE WESTERLIES AND LIFTS OUT TOWARD THE WEEKEND. ALTHOUGH PROBABILITIES REMAIN LOW GIVEN NATURE OF THE COVERAGE...ALMOST DAILY CHCS FOR SCT AFTN CONVECTION WILL BE THE RULE FOR MUCH OF THE WORK WEEK AS LLVL MOISTURE INC. HOWEVER...VFR CONDS WILL STILL BE THE DOMINATE FLIGHT CAT. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DEVOIR/CONNELLY NEAR TERM...DEVOIR/FITZGERALD SHORT TERM...DEVOIR LONG TERM...DANGELO/TYBURSKI AVIATION...STEINBUGL pa AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 1016 AM CDT MON JUL 23 2007 .DISCUSSION RAISED DEWPOINTS THIS MORNING AND INTO EARLY AFTERNOON AS THEY ARE CURRENTLY SITTING IN THE LOW TO MID 70S ACROSS THE FA. ALSO LOWERED LOWS SLIGHTLY IN NW IA WHERE AFTN TEMPS MAY BE A LITTLE COOLER AND RAIN COOLED AIR MAY AFFECT OVERNIGHT TEMPS. NAM AND RUC BOTH GENERATING PRECIP AROUND AND AFTER 00Z TONIGHT THROUGH NW IA THROUGH THE SUX AREA...BUT OTHER THAN INSTABILITY...IS NOT MUCH SUPPORT FOR SAID PRECIP TO OCCUR...SO WILL LOOK AT THIS MORE CLOSELY THIS AFTERNOON AND KEEP OUT OF THE GRIDS FOR NOW. && .AVIATION... IFR CIGS CONTINUE IN SUX AREA...BUT SHOULD MOVE OUT WITHIN THE HOUR. ONCE THIS CLEARS...TAF SITES WILL BE VFR FOR THE REST OF THE DAY. && .PREV DISCUSSION... SHRTWV MOVG SWD THEN SWWD ARND UPR RDG WILL BE MAINLY E OF FCST AREA TDA...BUT SOME SUPPORT WITH UPPER WINDS AND DECENT INSTBLTY AND MOISTURE WILL KEEP SOME THREAT MOF TSTMS OVER MAINLY SERN PART OF FCST AREA. WHILE THERE HASNT YET BEEN ANY DVLPMNT...SPORADIC MID CLD DVLPMNT OVER AND UPWIND OF AREA IS ALSO AN INDICATION THAT SPOTTY CONVECTION WILL HAVE TO BE ALLOWED FOR. YKN/FSD AND UP TO MML/MWM IN SWRN MN SHUD BE ON THE EDGE OF THIS THREAT...WITH THE CHC DCRG FROM THE N LATER IN THE DAY. IN FACT SUPPORT SEENS TO MOVE FAST ENUF TO KEEP OUT ANY MENTION FOR THIS EVE/TNGT AS WE HAVE BEEN DOING. CURNT MOVMNT OF MCS OVER ERN IA IS DECEPTIVE WITH ACTVTY WANTG TO REDVLP ON THE N SIDE. EVENTUALLY EXPECT SPOTTY STORMS TO DVLP FRTHR W INTO OUR FCST AREA THIS MRNG. UPPER RDGNG AND DCRG INSTBLTY NOT TO MENTION CAPPING SHUD THEN TAKE OVER AND KEEP OUT PCPN THREAT TNGT THRU WED NGT. WILL MAKE NO CHANGE IN THU THRU SUN PD WITH THREAT OF TSTMS THU AFTN THRU FRI MRNG...THEN A RETURN TO DRY.SOME QSTN ON STRENGTH AND PSBLY EXISTENCE OF THIS CDFNT BUTEVEN A WEAK FNT/BOUNDRY CUD BRING SOME DVLPMNT. WARM AND HUMID WX WILL CONT WITH GNLY 90S EXPECTED...SOME UPPER 80S EAST...THEN WILL KEEP THE LITTLE COOLING AND DRYING WE HAVE FOR LATER IN THE WEEK. LATEST GFS PRESENTS SOME DOUBT ON MUCH BREAKING DOWN OF RDG THO NEXT RUNS CUD GO THE OTHER WAY. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ LAFLIN/JM/WILLIAMS sd AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 900 PM CDT SUN JUL 22 2007 .DISCUSSION... MAIN CONCERN TONIGHT IS CONVECTIVE CHANCES LATE. KABR SOUNDINGS SHOWS A VERY STEEP 700-500 MB LAPSE RATE - ON THE ORDER OF 9 C/KM. HOWEVER...A SIGNIFICANT CAP EXISTS BETWEEN 900 MB AND 750 MB. 21Z RUC 3 H FORECAST IS IN LINE WITH THIS AND SHOWS THIS CAP BEING MAINTAINED THROUGH THE NIGHT IN SD. SO LOWERED POPS IN MUCH OF SOUTHEAST SD. HOWEVER...IN WRN MN...CAP IS EXPECTED TO WEAKEN FOR PARCELS LIFTED FROM 850 MB. WITH WEAK WAVE ON WV MOVING SOUTHEASET INTO NRN MN...EXPECT COMBINATION OF WEAK LOW LEVEL BOUNDARY AND UPPER WAVE WILL BE ENOUGH TO GET CONVECTION GOING IN SRN MN. WITH STEEP LAPSE RATES AND DRY AIR ALOFT AS WELL AS VERY UNSTABLE AIR TO FEED UPDRAFTS...EXPECT THAT THIS CONVECTION COULD BECOME SEVERE LATER TONIGHT AS IT MOVES SOUTH. THE QUESTION IS WILL CONVECTION FORM FAR ENOUGH WEST TO AFFECT SW MN AND NW IA. CURRENT THINKING IS THAT CONVECTION IS MOST LIKELY TO BE JUST EAST OF THE CWA BUT WITH OUTFLOW SPREADING TO WEST AND UNSTABLE AIR IN PLACE...WARRANTS A MODERATE CHANCE OF CONVECTION FROM WINDOM DOWN TO KSPW LATE TONIGHT. WHILE HAIL IS UNLIKELY GIVEN MARGINAL SHEAR FOR SUPERCELLS AND VERY WARM AIR ALOFT...DAMAGING WINDS ARE A THREAT EAST OF A LINE FROM KMML TO KSLB. BASED UPON TIMING OF WAVE...WOULD NOT EXPECT CONVECTION TO REACH THE AREA UNTIL WELL AFTER MIDNIGHT AND IT COULD BE AFTER DAWN IN NW IA. INTERESTINGLY AS CONVECTION MOVES SOUTH IT SHOULD BEGIN TO TURN TO THE SOUTHWEST AND APPROACH SUX AREA BY TOMORROW MORNING. OTHERWISE WITH DEW POINTS IN THE 70S IN MOST AREAS...RAISED MINS TO BE AT OR ABOVE YESTERDAY. WOULD NOT BE SURPRISED IF AREAS WEST OF THE JAMES SPEND MOST OF THE NIGHT AT 80 OR ABOVE. WITH CLOUDS AND CONVECTION POSSIBLE TOMORROW MORNING...SLOWED THE RISE OF TEMPS IN NW IA. GRIDS AND PFM AVAILABLE. ZFP OUT SHORTLY. && .PREV DISCUSSION... WEAK FRONTAL BOUNDARY EXTENDING FROM EASTERN NORTH DAKOTA ACROSS CENTRAL SD TO THE NEBRASKA PANHANDLE THIS SUNDAY AFTERNOON WILL SAG SLOWLY SOUTHEAST OVERNIGHT...AND WILL ACT AS A POSSIBLE FOCUS FOR SCATTERED THUNDERSTORMS...WITH THE BEST CHANCE ACROSS THE EASTERN PORTION OF THE CWA LATE TONIGHT. MOISTURE POOLING IN ADVANCE OF THE FRONT WILL HOLD DEW PTS AROUND 70 OVERNIGHT MOST AREAS...SO LOWS TONIGHT WILL BE SIMILAR TO LAST NIGHT...PERHAPS EVEN A DEGREE OR TWO WARMER...ESPECIALLY ACROSS THE WESTERN PART OF THE FA. FRONT SHOULD EXTEND ACROSS SOUTHERN MN AND NW IA MONDAY FOR CONTINUED THUNDERSTORM THREAT THAT AREA...DRIER...BUT STILL VERY WARM AIR BEHIND THE FRONT ACROSS THE REST OF THE CWA MONDAY. ON MON...IF TRW WERE ABLE TO DEVELOP OVERNIGHT...THEY WUD LIKELY BE AFFECTING NW IA IN THE MORNING HOURS AS S/W AND FNT SAGS INTO NW IA. SO WL HAVE HIGHEST POPS THERE. PBLM THEN ARISES TO TEMP FCST. IF MCS DEVELOPS...WUD EXPECT RAIN COOLED ELY FLOW OVR CWA ESPEC IN THE MORN...AND PERSIST ACRS ERN CWA THRU AFTN. THIS CUD KEEP HIGHS IN THE 80S EAST. FOR NOW...SINCE THERE IS UNCERTAINTY IF TRW WL EVE DEVELOP...WL GO CLOSER TO HIGHS NR 90 ACRS THE E WITH 90S ACRS THE WEST. LOW LEVEL SELY FLOW WL PERSIST ACRS THE ERN CWA TUES INTO WED AND THIS WL LIMIT TEMPS FM REACHING TRUE POT AND WL LIKELY BE LIMITED TO LOWER 90S. FURTHER W...SHUD AGAIN BE NR 100 W OF JAMES VALLEY. WL KEEP CWA DRY TUES AND WED. MODELS NOW QUICKER ON BRINING CDFNT THRU CWA THU INTO FRI MORN. MODELS MAY BE A TAD TOO FAST WITH THIS FEATURE...BUT NONETHELESS FNT SHUD MOVE SEWD ACRS CWA. CAPPED AIR AHEAD OF FNT MAY LIMIT TRW TO ALONG AND JUST BEHIND FNT. SO WL PROG TRW WITH THIS IN MIND. ALSO SHUD NOT HEAT OUT AS WELL BEHIND FNT ON THU AND HAVE COOLED TEMPS ACRS THE N. SAT AND SUN SHUD BE COOLER WITH HIGHS IN THE 80S TO LOWER 90S WITH WARMEST TEMPS ACRS THE WEST. && .AVIATION... VFR SHOULD PREVAIL EXCPT FOR SOME MVFR VSBYS IN BR PSBL NE OF LN FM HON TO FSD TO SUX FM 10Z TO 14Z. THERE IS ALSO A CHC OF TSTMS E OF I29 AFT 07Z OR SO...ESP E OF A MML TO SPW LINE. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ sd AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 145 PM MDT SUN JUL 22 2007 .DISCUSSION...LATEST ANALYSIS PLACES A BACKDOOR COLD FRONT ACROSS THE CWA ATTM. TEMPERATURES ARE AGAIN RISING TODAY INTO THE UPPER 90S TO ABOVE 100. DEWPOINTS IN THE 60S AND 70S ACROSS THE CENTRAL PLAINS WERE ADVECTING NORTH THROUGH ERN SOUTH DAKOTA INTO NORTH DAKOTA...THEN PIVOTING AROUND BACK INTO NW SOUTH DAKOTA. AREAS ACROSS HARDING AND PERKINS COUNTIES ARE SEEING TEMPERATURES IN THE MID TO UPPER 90S WITH DEWPOINTS IN THE 60S...A STICKY EXCEPTION BEING BOWMAN ND WITH A T/TD OF 99/70 AT 1930Z. CAPE VALUES ARE ESTIMATED TO BE ABOVE 4000 J/KG...BUT THERE IS STILL A DECENT CAP IN PLACE WHICH IS PREVENTING A CU FIELD FROM DEVELOPING SO FAR. RUC SHOWS THE CAP ERODING OVER THE NEXT FEW HOURS...SO WILL LEAVE IN SL CHC POPS THIS AFTERNOON AND EVENING. FARTHER SOUTH ACROSS THE BLACK HILLS AND PARTS OF NE WYOMING...DEWPOINTS ARE 10 TO 15 DEGREES LOWER...BUT STILL ENOUGH INSTABILITY AND ENOUGH OF A WEAK CAP TO EXPECT A FEW STORMS THIS AFTERNOON AND EVENING. VERTICAL PROFILES CONTINUE TO SHOW WEAK SHEAR ACROSS THE CWA. SOME CU HAVE ALREADY DEVELOPED ACROSS WESTON COUNTY WHICH MAY BE THE INITIAL FOCUS FOR CONVECTION. LITTLE CHANGE TO THE WEATHER PATTERN FOR THE REST OF THE SHORT TERM. STRONG UPPER RIDGE REMAINS ACROSS THE CENTRAL PARTS OF THE CONUS ALONG WITH A THERMAL RIDGE AXIS CENTERED ACROSS THE NORTHERN HIGH PLAINS. 700 MB TEMPS WILL AGAIN RANGE BETWEEN 14 TO 18C TOMORROW AND TUESDAY...JUST LIKE TODAY...RESULTING IN HIGHS ABOVE 100. NOT AS MUCH INSTABILITY EXPECTED TOMORROW OR TUESDAY...SO HAVE LEFT OUT MENTION OF POPS SO FAR. EXTENDED...A VIGOROUS UPPER LEVEL SHORTWAVE WILL RACE ACROSS CENTRAL CANADA ON WEDNESDAY...FLATTENING THE UPPER RIDGE AND ALLOWING CANADIAN HIGH PRESSURE TO NOSE INTO THE NORTHERN PLAINS. THIS SYSTEM WILL PROVIDE A BRIEF REPRIEVE FROM THE TRIPLE DIGIT HEAT...AND ALSO BRING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA WEDNESDAY AFTERNOON INTO THURSDAY. THE UPPER LEVEL RIDGE WILL REBUILD OVER THE NORTHERN PLAINS FOR FRIDAY INTO THE WEEKEND...ALLOWING THE HOT TEMPERATURES TO RETURN. && .AVIATION...VFR CONDITIONS WILL CONTINUE ACROSS THE AREA INTO MONDAY. A FEW STORMS ARE ANTICIPATED FROM THE BLACK HILLS AREA WESTWARD DURING THE LATE AFTERNOON AND EVENING. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ CALDERON/RUDGE sd AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 1047 AM CDT SUN JUL 22 2007 .DISCUSSION... HAVE UPDATED GRIDS AND ZFP TO REFLECT A BOOST IN HIGH TEMPERATURES ACROSS MUCH OF THE CWA...WITH THE BIGGEST CHANGE ACROSS THE SW. ALSO ADDED SPRINKLES FOR THE REST OF THE MORNING ACROSS THE EXTREME NORTH...REMANENTS OF THE DYING THUNDERSTORMS ACROSS NE SOUTH DAKOTA THIS MORNING. THIS ACTIVITY SHOULD CONTINUE TO DECREASE AS THE REST OF THE MORNING PROGRESSES. MAY BE JUST ENOUGH TO DAMPEN THE SIDEWALKS ACROSS OUR NORTHERN TIER COUNTIES THRU NOON. MORE FAVORABLE S-SW SFC WIND THIS AFTERNOON ACROSS THE AREA...SO USED THE LATEST 850 RUC TEMPS AS PRIMARY GUIDANCE FOR THE MAX TEMP ADJUSTMENTS. BLOW OFF CIRRUS FROM THE MORNING THUNDERSTORMS SHOULD THIN OUT DURING THE AFTERNOON SO NOT EXPECTING CLOUDS TO BE A LIMITING FACTOR IN REACHING AFTERNOON POTENTIAL TEMPERATURES...ESPECIALLY ACROSS THE SW PART OF THE CWA. TONIGHT`S SLIGHT CHANCE OF TRW ACROSS OUR EASTERN COUNTIES STILL LOOKS REASONABLE...BUT MAY EXTEND THE THREAT A BIT FURTHER WEST THAN CURRENT GRIDS...TO THE I-20 CORRIDOR AREA...WILL TAKE A CLOSER LOOK THIS AFTERNOON. && .AVIATION... PATCHY EARLY MORNING IFR CIGS HAVE LIFTED WITH THE MID MORNING WARM UP...SO VFR REST OF DAY. && GH .PREV DISCUSSION... TURN TO MORE SRLY LOW LEVEL FLOW SEEMS TO HAVE DRIED LYR OUT FOR NOW AND LOW CLDS DONT SEEM TO BE A CONCERN FOR THE TIME BEING. STILL EXPECT SOME CU/SC TO HEAT OUT BY AFTN IN THE E. CONVECTION THREAT THRU THIS EVE SEEMS TO BE N/E OF FCST AREA AND THIS MAY CONT LATE TNGT THRU MON AS MODELS SHOW UPPER RDGNG FRTHR E THAN THIS TIME YSTDY. ANY CONVECTION THAT DVLPS NE OF FCST AREA CUD DROP SWD OR SSWWD LATR TNGT AND MO AND WILL LEAVE SMALL CHC MENTION FAR ERN FCST AREA BUT IT IS PRETTY SMALL WITH ABV MENTIONED RDGNG AND NOT MUCH ARND TO FOCUS DVLPMNT. MORE THAN LIKELY IT WILL CONT DRY OVER FCST AREA TILL AT LEAST THE END OF THE WEEK WHEN WE WILL LEAVE MENTN IN FOR FRI/FRI NGT AS RDG APPARENTLY SLWLY BREAKS DOWN AND SFC FNT SLIPS SWD INTO FCST AREA. LITTLE CHANGE TO TEMP PATTERN NEXT FEW DAYS WITH TEMPS GETTING TO MOSTLY 90S HIGHS...ARND 90 E TO NEAR 100 SW. ALSO CONTD WARM NIGHTTIME TEMPS. A LITTLE COOLING TWRDS END OF WEEK AS RDG BREAKS DOWN SOME. && .AVIATION... GENERALLY VFR CONDITIONS EXPECTED THROUGH PERIOD. PATCHY MVFR STRATUS/FOG POSSIBLE EAST OF THE JAMES RIVER EARLY THIS MORNING... THOUGH INCREASE IN HIGH CLOUDS OVER THE AREA MAY LIMIT AREAL EXTENT. ISOLATED MID LEVEL BASED SHRA/TSRA MOVING SOUTHEAST INTO WESTERN MN MAY AFFECT PORTIONS OF TWEB RTE 243 AFTER 14Z...WITH ANY TSRA XPCTD TO REMAIN EAST OF KHON/KFSD/KSUX TAF LOCATIONS THROUGH TONIGHT. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ WILLIAMS/JH sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 1045 AM CDT SUN JUL 22 2007 .DISCUSSION... SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE DEVELOPING NEAR BOUNDARY AS IT PUSHES GRADUALLY WEST ACROSS CWFA. THIS BOUNDARY IS BEING AIDED WITH ADDITIONAL LIFT BY A WEAK UPPER LEVEL JET NOSING SOUTH SOUTHWEST TOWARD EAST TEXAS. PW VALUES STILL QUITE HIGH (NEAR 2 INCHES) ACROSS SOUTHERN HALF OF CWFA AND GRADUALLY TAPERS DOWN NORTH AND NORTHEAST OF REGION. SURFACE DEWPOINTS IN THE MID TO UPPER 60S NOTED OVER PORTIONS OF NORTHEAST TEXAS. LATEST 4KM WRF INDICATE BROKEN BAND OF CONVECTION MOVING TO OUR WESTERN ZONES BY THIS AFTERNOON. MORNING SOUNDINGS INDICATE CONVECTIVE TEMPERATURES IN THE UPPER 80S. WE SHOULD SEE CONVECTION FIRING UP BEHIND BOUNDARY DURING AFTERNOON GIVEN APPROACHING UPPER LEVEL JET AND STILL UNSTABLE AND RELATIVELY MOIST AIR MASS. ZFPHG ON TRACK. 37 && .PREV DISCUSSION... /ISSUED 715 AM CDT SUN JUL 22 2007/ UPDATE... RAISED POPS BASED ON CURRENT RADAR TRENDS. RUC/GFS SEEM A LITTLE SLOW WITH PLACEMENT OF SHRA/TSRA. RAISED POPS TO 50 AREAWIDE THIS MORNING. DRIER AIR SHOULD WORK INTO THE EASTERN ZONES THIS AFTERNOON. NEW ZONES ALREADY OUT. 43 PREV DISCUSSION... /ISSUED 319 AM CDT SUN JUL 22 2007/ DISCUSSION... AT 06Z...A SURFACE BOUNDARY WAS LOCATED FROM ABOUT SHV TO LFT. THIS BOUNDARY SEPARATES MOIST AIR ON THE WEST TO CONSIDERABLY DRIER AIR TO THE EAST. THIS BOUNDARY WILL PUSH SLOWLY WEST TODAY AND WILL LIKELY SERVE AS A FOCUS FOR SHOWERS AND THUNDERSTORMS. ONGOING CONVECTION OVER WESTERN LA WILL PROBABLY WEAKEN THIS MORNING AND INTENSIFY WITH PEAK HEATING LATER THIS AFTERNOON. FORECAST SOUNDINGS THIS AFTERNOON SHOW STRONG INSTABILITY PRESENT ALONG WITH AN INVERTED V SIGNATURE. WOULD NOT BE SURPRISED IF A FEW STORMS PRODUCED SOME WIND DAMAGE THIS AFTERNOON. GFS/NAM IN GOOD AGREEMENT WITH DRYING THE REGION OUT MON-WED AND HAVE TRIMMED POPS BACK AND RAISED MAX TEMPS. WITH LOWER SURFACE DEW POINTS IN PLACE...OVERNIGHT LOWS WILL BE A TOUCH COOLER. GFS QUITE AGGRESSIVE WITH MOISTURE RETURN ON THURSDAY AND IS CONSIDERABLY FASTER THAN THE CAN/ECMWF. PREFER THE SLOWER CAN/ECMWF WITH MOISTURE RETURN AS THESE MODELS HAVE HANDLED TODAYS DRY AIR INTRUSION BETTER THAN THE GFS. TROPICAL MOISTURE IS IN PLACE FRI-SUN AND IT LOOKS LIKE ANOTHER WET PERIOD FOR SOUTHEAST TEXAS. AVIATION... MVFR CONDITIONS DUE TO PATCHY FOG ARE EXPECTED AT CLL...UTS...AND CXO THROUGH 14Z. AT LBX...THE GROUND FOG MAY GENERATE IFR CONDITIONS THROUGH 09Z. AFTER 14Z...VFR CONDITIONS ARE EXPECTED. WITH A WEAK BACK DOOR COLD FRONT MOVING ACROSS THE AREA...ISOLATED SHOWERS OR THUNDERSTORMS WILL BE POSSIBLE MAINLY DURING THE AFTERNOON. 40 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 715 AM CDT SUN JUL 22 2007 .UPDATE... RAISED POPS BASED ON CURRENT RADAR TRENDS. RUC/GFS SEEM A LITTLE SLOW WITH PLACEMENT OF SHRA/TSRA. RAISED POPS TO 50 AREAWIDE THIS MORNING. DRIER AIR SHOULD WORK INTO THE EASTERN ZONES THIS AFTERNOON. NEW ZONES ALREADY OUT. 43 && .PREV DISCUSSION... /ISSUED 319 AM CDT SUN JUL 22 2007/ DISCUSSION... AT 06Z...A SURFACE BOUNDARY WAS LOCATED FROM ABOUT SHV TO LFT. THIS BOUNDARY SEPARATES MOIST AIR ON THE WEST TO CONSIDERABLY DRIER AIR TO THE EAST. THIS BOUNDARY WILL PUSH SLOWLY WEST TODAY AND WILL LIKELY SERVE AS A FOCUS FOR SHOWERS AND THUNDERSTORMS. ONGOING CONVECTION OVER WESTERN LA WILL PROBABLY WEAKEN THIS MORNING AND INTENSIFY WITH PEAK HEATING LATER THIS AFTERNOON. FORECAST SOUNDINGS THIS AFTERNOON SHOW STRONG INSTABILITY PRESENT ALONG WITH AN INVERTED V SIGNATURE. WOULD NOT BE SURPRISED IF A FEW STORMS PRODUCED SOME WIND DAMAGE THIS AFTERNOON. GFS/NAM IN GOOD AGREEMENT WITH DRYING THE REGION OUT MON-WED AND HAVE TRIMMED POPS BACK AND RAISED MAX TEMPS. WITH LOWER SURFACE DEW POINTS IN PLACE...OVERNIGHT LOWS WILL BE A TOUCH COOLER. GFS QUITE AGGRESSIVE WITH MOISTURE RETURN ON THURSDAY AND IS CONSIDERABLY FASTER THAN THE CAN/ECMWF. PREFER THE SLOWER CAN/ECMWF WITH MOISTURE RETURN AS THESE MODELS HAVE HANDLED TODAYS DRY AIR INTRUSION BETTER THAN THE GFS. TROPICAL MOISTURE IS IN PLACE FRI-SUN AND IT LOOKS LIKE ANOTHER WET PERIOD FOR SOUTHEAST TEXAS. AVIATION... MVFR CONDITIONS DUE TO PATCHY FOG ARE EXPECTED AT CLL...UTS...AND CXO THROUGH 14Z. AT LBX...THE GROUND FOG MAY GENERATE IFR CONDITIONS THROUGH 09Z. AFTER 14Z...VFR CONDITIONS ARE EXPECTED. WITH A WEAK BACK DOOR COLD FRONT MOVING ACROSS THE AREA...ISOLATED SHOWERS OR THUNDERSTORMS WILL BE POSSIBLE MAINLY DURING THE AFTERNOON. 40 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 92 72 93 69 93 / 50 20 20 10 10 HOUSTON (IAH) 91 73 91 72 91 / 50 20 20 10 10 GALVESTON (GLS) 88 79 89 77 89 / 50 20 20 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...43 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 938 PM CDT MON JUL 23 2007 .UPDATE... MAY NEED TO ADD SOME SPRINKLES/ISOLD SHRA TO FORECAST FOR LATER TONIGHT BASED ON 24.00Z RUC/WRF. BOTH THESE DATA SHOWING WEAK 60KT JET IN 300-250 MB DIVING SOUTHWEST INTO MIS MS RIVER VALLEY...PLACING PORTIONS OF FCST AREA IN WEAK RIGHT ENTRANCE REGION FORCING FOR ASCENT. SEE A MEAGER RESPONSE IN THE 800-700MB FRONTOGENETIC REGION IN THIS AREA OF UPPER FORCING...OVER THE MEAN MOISTURE AXIS RUNNING NE-SW ACROSS THE REGION. RADAR BEEN SILENT THUS FAR...BUT HINTS OF A FEW ECHOES PERHAPS ABOUT TO GROW EAST OF BLACK RIVER FALLS. SREF PROBABILITIES FOR MEASURABLE RAIN VERY LOW...BUT HAVE TO THINK LATEST DETERMINISTIC WRF SOLN WHICH SHOWS PERSISTENT VERY LIGHT SHRA ACROSS PORTIONS OF THE AREA THROUGH NIGHT HAS SOME MERIT. LAPS SOUNDINGS AND FORECAST BUFR SOUNDINGS SHOWING VERY LITTLE ELEVATED INSTABILITY...AND GIVEN VERY WEAK FORCING SIGNAL...WILL KEEP THUNDER OUT...AND PROBABILITIES LOW...IF ADDED TO FORECAST. MAY SEE SOME PATCHY FOG OUTSIDE CLOUD AREAS...BUT HAVE A FEELING CLOUDS WILL FILL IN A LITTLE MORE WITH TIME...PUTTING WIDESPREAD FOG POSSIBILITIES...AND VSBY RESTRICTIONS...RATHER LOW. BINAU && .PREV DISCUSSION... /ISSUED 236 PM CDT MON JUL 23 2007/ SHORT TERM...THROUGH WEDNESDAY NIGHT MAIN FORECAST CONCERNS ARE THE CLOUD TRENDS EARLY IN THE PERIOD AND ANY RAIN CHANCES FOR TUESDAY. SURFACE ANALYSIS THIS AFTERNOON SHOWS HIGH PRESSURE OVER THE EASTERN GREAT LAKES. A VERY WEAK TROUGH OF LOW PRESSURE/CONVERGENCE LINE EXTENDED FROM THE WESTERN TIP OF THE U.P. OF MICHIGAN INTO SOUTHWEST MINNESOTA. SATELLITE SHOWING LOTS OF CLOUDS FROM THE SURFACE TROUGH EAST INTO WISCONSIN. THE CLOUD FORECAST FOR TONIGHT INTO TUESDAY PRESENTS A LOT OF UNCERTAINTY IN THE FORECAST. THE NAM HAS DONE A DECENT JOB OF CAPTURING THE HIGHER MOISTURE FIELDS WHERE THE CLOUDS PRESENTLY ARE. IT THEN INDICATES VERY LITTLE CHANGE IN THE AMOUNT OR LOCATION OF THE MOISTURE THROUGH TUESDAY. HOWEVER...THE VISIBLE SATELLITE CLEARLY SHOWS THAT SOME OF THE CLOUDS ON THE SOUTH AND EAST EDGES ARE DIURNAL CUMULUS AND SHOULD DISSIPATE THIS EVENING AND THERE ARE HOLES IN OTHER PARTS OF THE CLOUD SHIELD. THE WEAK SURFACE TROUGH IS NOT EXPECTED TO MOVE MUCH TONIGHT AND THERE ARE WEAK PERIODS OF THETA-E CONVERGENCE THAT OCCUR AT 700 AND 500 MB. HAVE RAISED THE CLOUD COVER INITIALLY FOR TONIGHT TO REFLECT WHAT IS CURRENTLY HAPPENING...BUT AFTER THAT ONLY MADE SMALL INCREASES IN THE CLOUD COVER GIVEN ALL THE UNKNOWNS THAT EXIST AT THIS POINT. ALSO...WITH LOW CONFIDENCE IN THE CLOUD FORECAST...EVEN LOWER CONFIDENCE IN WHETHER FOG WILL DEVELOP OVERNIGHT. SINCE DENSE FOG IS NOT EXPECTED TO FORM...OPTED TO REMOVE THE MENTION OF PATCHY FOG FOR NOW. A SHORT WAVE TROUGH LEFT OVER FROM LAST NIGHTS CONVECTION OVER NORTH DAKOTA IS EXPECTED TO ROUND THE TOP OF THE RIDGE AND DROP SOUTH ACROSS THE UPPER MIDWEST TUESDAY. BOTH THE NAM AND GFS INDICATE THIS WAVE SHOULD DROP SOUTH ACROSS WESTERN MINNESOTA KEEPING THE BEST FORCING TO THE WEST OF THE AREA. NEITHER THE NAM OR GFS SHOW ANY RAIN DEVELOPING WITH THIS WAVE AND THE 09Z SREF PROBABILITIES ARE 5 OR LESS...SO WILL MAINTAIN THE DRY FORECAST. VERY FEW CHANGES MADE FOR THE REMAINDER OF THE PERIOD. STILL SOME CONCERN ABOUT THE CLOUD COVER AS THE NAM CONTINUES TO SHOW THE BETTER MOISTURE FIELDS REMAINING OVER THE EASTERN HALF OF THE FORECAST AREA THROUGH WEDNESDAY NIGHT. OTHERWISE...A GENERAL SOUTHWEST LOW LEVEL FLOW WILL DEVELOP AHEAD OF A APPROACHING COLD FRONT THAT WILL HELP TEMPERATURES AND DEW POINTS SLOWLY RISE. LONG TERM...THURSDAY THROUGH MONDAY MEDIUM RANGE MODELS CONTINUE TO BE IN GOOD AGREEMENT THROUGH THE PERIOD BUT STILL HAVE RUN TO RUN CONSISTENCY PROBLEMS WITH THE CUT OFF LOW OVER THE EASTERN PART OF THE COUNTRY. LATEST GUIDANCE NOW SUGGESTS THE LOW WILL RETROGRADE TO THE NORTHWEST ENDING UP OVER LOWER MICHIGAN THURSDAY BEFORE BECOMING AN OPEN WAVE AND LIFTING OUT TO THE NORTHEAST. DESPITE THESE CHANGES...STILL LOOKING FOR A SHORT WAVE TROUGH TO TOP THE UPPER LEVEL RIDGE AND COME ACROSS THE UPPER MIDWEST THURSDAY NIGHT AND FRIDAY. A COLD FRONT IS EXPECTED TO COME THROUGH AS WELL WITH THE BEST UPPER LEVEL FORCING OCCURRING BEHIND THE FRONT. BECAUSE OF THIS...WILL CONTINUE TO MAINLY LIMIT THE POPS TO THE THURSDAY NIGHT/FRIDAY TIME FRAME WITH LITTLE ACTIVITY EXPECTED THURSDAY AHEAD OF THE FRONT. WITH THE QUICKER MOVEMENT OF THE UPPER LEVEL LOW...THE FRONT SHOULD ALSO BE QUICKER TO CLEAR THE AREA AND WILL DROP THE POPS FOR SATURDAY. AVIATION...MVFR CLOUD DECK HAD PERSISTED ACROSS THE AREA THROUGH THE EARLY AFTERNOON HOURS ON MONDAY. MODELS ARE SHOWING LOW LEVEL MOISTURE TO STICK AROUND INTO THE DAY TOMORROW. HAD LITTLE CONFIDENCE WHETHER THE CLOUDS WOULD SCATTER OUT THIS EVENING OR IF THEY WOULD STAY BROKEN OVER THE REGION...OR WITH THE FOG FORMATION IN THE MORNING...SO LEFT THOSE TRENDS GOING AT BOTH TAFS SITES. IF CLOUD COVER STAYS BKN TO OVC OVERNIGHT EXPECT LITTLE IF ANY FOG FORMATION TUESDAY MORNING. EXPECTING MVFR CEILINGS ACROSS BOTH SITES TUESDAY MORNING. ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. $$ SHORT/LONG TERM...04 AVIATION...BROOKS && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 400 AM CDT MON JUL 23 2007 .DISCUSSION...FCST FOCUS IS HANDLING ANY SLIM RAIN CHANCES OVER THE NEXT FEW DAYS. ATTM MCS DROPPING SW ACRS IA BEING FED BY STRONG LOW LEVEL...925-700MB CONVERGENCE AND DECENT THETA-E ADVECTION. MODELS ALL IN GOOD AGREEMENT KEEPING THE FOCUS TO OUR WEST TODAY AS THE DRY HIGH LINGERS. WATER VAPOR/RUC COMBO DOES SHOW ANOTHER WEAK WAVE VCNTY MN ARRROWHEAD HEADING SEWD THRU RDG AXIS. MODELS SHOW THIS FEATURE ELONGATING/SHEARING OUT WITH TIME AS IT WORKS ITS WAY INTO THE RIDGE AXIS. VERY WEAK LOW LEVEL FORCING ACRS OUR CWA WITH MOIST AXIS FROM IA NORTH INTO MN AND THEN INTO NRN WI. PATTERN REMAINS LARGELY UNCHANGED INTO THURSDAY WITH UPPER RIDGE AXIS TO OUR NW AND SLOWLY ENCROACHING RETRGRADING UPPER LOW TO OUR EAST. INCREASING UPPER CONFLUENCE SUGGESTS ANY VORT WILL BE HIGHLY SHEARED WITHIN THIS FLOW. LOW LEVEL FLOW LOOKS QUITE WEAK. WRF20 AND GFS MOS DEW POINTS LOOK MORE REASONABLE THAN MODEL AND MOS DEWS FROM THE NAM. THUS THE INSTAB AND QPF BEING GENERATED BY THE NAM LOOKS OVERDONE FOR TUESDAY. GFS SOUNDINGS DO SHOW SOME MID LEVEL SATURATION BUT LACK OF LOW LEVEL CONVERGENCE AND UPPER SUPPORT SUGGEST GOING WITH A DRY FCST. 00Z GFS SHOWS A HIGHLY SUSPICIOUS VORT BREAKING DOWN THE RIDGE FOR THU NGT AND FRIDAY. 00Z ECMWF SHOWS MORE UPPER RIDGING THU NGT/FRI BUT STILL SHOW A WEAK SFC TROUGH SLIDING THROUGH. && 10 .AVIATION...SURFACE HIGH OVER THE GREAT LAKES TO NEW ENGLAND. VFR CONDITIONS EXCEPT FOR ISOLATED MVFR/IFR VSBYS IN FOG TIL 14Z. SOME STRATOCUMULUS AROUND 5 THSD FT OVR SOUTH CENTRAL WISCONIN. && .MKX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 250 AM CDT MON JUL 23 2007 .SHORT TERM...THROUGH WEDNESDAY NIGHT FORECAST CONCERNS WERE PRIMARILY FOCUSED ON RAIN CHANCES TODAY AND IF ADDITIONAL RAIN CHANCES MAY BE WARRANTED TONIGHT INTO WEDNESDAY. MCS THAT BROUGHT LOCALLY HEAVY RAIN TO PARTS OF THE FORECAST AREA LAST EVENING HAD SHIFTED SOUTHWARD INTO IOWA. MEANWHILE...SCATTERED CONVECTION STILL DEVELOPING AND PROPAGATING SOUTHWARD IN WAKE OF THIS SYSTEM. WEAKENING LOW LEVEL JET PER LATEST RUC SUGGESTS SCATTERED CONVECTION SHOULD CONTINUE THIS MORNING. WATER VAPOR IMAGERY INDICATED SHORT WAVE THAT INITIATED LAST EVENING CONVECTION DROPPING SOUTHWARD INTO IOWA. MEANWHILE...ANOTHER WAVE WAS NOTED ALONG MN/CANADIAN BORDER...ADVANCING SOUTHEASTWARD AROUND PERIPHERY OF 500MB RIDGE ANCHORED OVER PLAINS. DIFFERENCES NOTED IN 00Z 23JUL07 DETERMINISTIC GFS AND NAM/WRF WAS WITH DETAILS OF QPF TODAY THROUGH WEDNESDAY. NAM/WRF CONTINUES TO SUGGEST RAIN CHANCES...WHILE GFS WAS DRY ACROSS THE FORECAST AREA. 21Z 22JUL07 SREF INDICATED HIGHEST RAIN PROBABILITIES SHIFTING INTO INTO IOWA TODAY...THEN LOW-END PROBABILITIES CONTINUING TONIGHT THROUGH WEDNESDAY. AT THIS TIME...CONFIDENCE WAS HIGH ENOUGH TO MAINTAIN SPIRIT OF FORECAST...WITH RAIN CHANCES LINGERING TODAY. MODEL DIFFERENCES TONIGHT THROUGH WEDNESDAY LEND LOWER CONFIDENCE... THUS OPTED TO CONTINUE WITH DRY FORECAST. TODAY...MN/CANADIAN BORDER SHORT WAVE EXPECTED TO TRACK SOUTHWARD. MEANWHILE...LOW LEVEL THETA-E CONVERGENCE AND SBCAPE VALUES OF 1000-2000 J/KG LINGERS ALONG A NORTHEAST-SOUTHWEST AXIS THROUGH THE FORECAST AREA. INTERACTION BETWEEN SHORT WAVE AND MOIST/UNSTABLE BOUNDARY LAYER SHOULD CONTINUE TO PROMOTE SCATTERED CONVECTION. TONIGHT THROUGH WEDNESDAY...AS MENTIONED EARLIER...CONFIDENCE NOT AS HIGH AS ONE WOULD LIKE WITH REGARDS TO INCLUDING ADDITIONAL RAIN CHANCES. ONE THING FOR CERTAIN...APPEARS ATMOSPHERE SHOULD BE PRIMED FOR FOG DEVELOPMENT TONIGHT...WHAT WITH LIGHT WINDS AND MOIST BOUNDARY LAYER. THEREFORE...FORECAST CONFIDENCE WAS HIGH ENOUGH TO INCLUDE MENTION OF FOG TONIGHT INTO TUESDAY MORNING. .LONG TERM...THURSDAY THROUGH SUNDAY LATEST PROBABILISTIC AND DETERMINISTIC DATA SUITE HAD CONSISTENT SIGNAL OF 500MB CLOSED LOW AMBLING FROM OHIO VALLEY TO LOWER GREAT LAKES REGION THROUGH MIDWEEK. MEANWHILE...500MB RIDGE REMAINS ANCHORED FROM PLAINS AND INTERMOUNTAIN WEST NORTHEASTWARD TOWARD LAKE SUPERIOR. THIS FEATURE ANTICIPATED TO EVENTUALLY FLATTEN...THUS ALLOWING FRONT TO SLIDE SOUTHWARD LATER IN THE WEEK. BOTH DETERMINISTIC 00Z 23JUL07 GFS AND ECMWF HAD SIMILAR TIMING OF FRONT MOVING THROUGH UPPER MISSISSIPPI VALLEY THURSDAY NIGHT INTO FRIDAY. RAIN CHANCES IN THIS TIME FRAME APPEARED REASONABLE... ALTHOUGH INCLUDING RAIN CHANCES ON THURSDAY MAY BE WARRANTED BASED ON MODEL TREND OF FRONTAL PROGRESSION PERHAPS ARRIVING A BIT SOONER. MODEL CONSENSUS SEEMS TO BE BUILDING FOR WEAK SURFACE HIGH PRESSURE RIDGE TO DRIFT ACROSS THE FORECAST AREA SATURDAY INTO SUNDAY. FORECAST CONFIDENCE INCREASING THAT DRY WEATHER IN THIS TIME FRAME SHOULD BE THE PROBABLE OUTCOME...AS SUPPORTED IN CURRENT DATA BASE. NO CHANGES WERE MADE IN THE EXTENDED OUTLOOK. && .AVIATION... WEAK SHORTWAVES IN THE NORTHERLY FLOW ALOFT WILL CONTINUE TO RIPPLE OVER THE AREA TODAY AND TONIGHT...HOWEVER THEIR IMPACT ON SHRA/TSRA CHANCES REMAIN UNCERTAIN. THE BETTER LOW LEVEL MOISTURE TRANSPORT/ THETA-E CONVERGENCE ARE OVER THE AREA THIS MORNING. WITH WEAK FORCING/LIFT...ONLY CARRIED VCSH IN TAFS THRU 15Z-16Z TIME-FRAME. WEAK MID LEVEL RIDGING BUILDS IN FOR THIS AFTERNOON/TONIGHT...WITH NO CONVECTIVE MENTION IN TAFS FOR AFTERNOON/TONIGHT HOURS. THOUGH CANNOT RULE OUT WDLY SCT -SHRA/TSRA ACROSS THE FORECAST AREA THRU THE AFTERNOON HOURS WITH DIURNAL WARMING/INCREASE OF INSTABILITY. ANOTHER CONCERN IS FOG POTENTIAL TONIGHT WITH THE MOIST BOUNDARY LAYER AIRMASS /DEW POINTS IN THE 60S AND RECENT RAINS/...PARTLY CLOUDY SKIES AND LIGHT SOUTH WINDS. APPEARS MUCH OF THE AREA MAY SEE VSBYS 2-5SM BR AFTER 06Z TONIGHT AND WILL ADD TO NEXT CYCLE OF TAFS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT/LONG TERM...THOMPSON AVIATION...RRS wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 829 PM CDT SUN JUL 22 2007 .UPDATE... FOCUS THIS EVENING IS LOCALIZED HEAVY/EXCESSIVE RAINFALL THREAT...WHETHER WE NEED A FLASH FLOOD WATCH...AND HOW THIS BAND OF STORMS FROM DUNN COUNTY TOWARD WINONA WILL BEHAVE. MANY HEAVY RAIN PARAMETERS CONFIRM AN IDEAL SETUP FOR TORRENTIAL RATES TONIGHT FOR ANY BANDS OF STORMS WE CAN GENERATE LIKE WE HAVE CURRENTLY. 23.00Z KMPX SOUNDING SHOWING A CAPPED SOUNDING TO SURFACE BASED PARCELS...BUT WITH AMPLE WARMTH/MOISTURE WITH PWATS TO 1.80 INCHES. KMPX VWP...AS WELL AS MPX SOUNDING SHOWING PERSISTENT 850MB JET OF 25-30KTS...FEEDING INTO WRN WISCONSIN WHERE KARX VWP IS SOUTHWEST /5KT/ AT 850MB SUGGESTING A GREAT DEAL OF CONVERGENCE. STORMS ORIGINALLY SPARKED WITH WEAK MCV FROM LAST NIGHT/S MCS ACROSS NRN MN...AND NOW BEING FED VERY UNSTABLE AIRMASS ABOVE THE STABILIZING BOUNDARY LAYER AS PARCELS HIT THE LFC IN DUNN/EAU CLAIRE COUNTIES IN MSP. 22.21Z RUC SHOWS THIS 25KT H85 LOW LEVEL JET/WEAK MOISTURE TRANSPORT SIGNAL TO REMAIN INTACT THROUGH MUCH OF THE NIGHT...SO OBVIOUS CONCERN IS WHETHER THIS TO EVOLVE INTO A MORE WIDESPREAD FLOOD THREAT RATHER THAN BUFFALO COUNTY AS IT IS NOW. CALLS TO LAW ENFORCEMENT THUS FAR INDICATING LITTLE WATER ISSUES...BUT IT/S THE REGENERATION OFF THE THE NORTH THAT HAS ME CONCERNED. HAVE ALREADY ADDED HEAVY RAINS TO ZONES...AND UPDATED HWO WITH THIS LINE OF THINKING. WILL MONITOR TRENDS...AND CONSIDER A FLOOD WATCH IF THIS CONTINUES TO SHOW THIS HIGH LEVEL OF ORGANIZATION. A FLASH FLOOD WARNING FOR BUFFALO COUNTY MAY BE NEEDED BY 9 OR 930 PM...AND DOWNSTREAM COUNTIES OF WINONA/FILLMORE WILL NEED TO BE WATCHED. FLASH FLOOD GUIDANCE VALUES ARE VERY HIGH SUGGESTING WE CAN TAKE A LOT OF WATER...AND CORFIDI VECTORS/THICKNESS ORIENTATION SUGGESTS DEVELOPING MCS/MESO BETA ELEMENTS MAY DRIFT SLOWLY WEST/SOUTHWEST OVER TIME...WHICH WE WOULD LIKE TO SEE TO MITIGATE FLOODING. BINAU && .PREV DISCUSSION... /ISSUED 245 PM CDT SUN JUL 22 2007/ SHORT TERM...THROUGH TUESDAY NIGHT FOCUS OF THE FORECAST IS ON THE RAIN CHANCES TONIGHT THROUGH MONDAY NIGHT. SURFACE ANALYSIS THIS AFTERNOON SHOWS HIGH PRESSURE CENTERED OVER LOWER MICHIGAN. A STATIONARY FRONT EXTENDED FROM EASTERN NORTH DAKOTA SOUTH INTO OKLAHOMA. LOCAL AND REGIONAL RADARS SHOW A COMPLEX OF SHOWERS AND THUNDERSTORMS OVER NORTHWEST WISCONSIN SLOWLY DROPPING SOUTHEAST. SHORT TERM MODELS IN PRETTY GOOD AGREEMENT THIS CYCLE TAKING THE SHORT WAVE TROUGH OVER NORTHERN MINNESOTA AND DROPPING IT SOUTH SOUTHWEST ACROSS WISCONSIN TONIGHT AND INTO IOWA MONDAY. THIS WAVE IS HELPING FUEL THE ONGOING CONVECTION TO THE NORTH AND EXPECT THIS ACTIVITY TO DROP SOUTH INTO THE AREA THIS EVENING. HAVE RAISED POPS ACROSS THE NORTH INTO THE LIKELY CATEGORY AND WILL MONITOR RADAR TRENDS TO SEE IF CATEGORICAL POPS WILL BE NEEDED. AREAL COVERAGE OF THE SHOWERS AND STORMS ARE EXPECTED TO INCREASE THROUGH THE NIGHT AS THE WAVE SLOWLY APPROACHES AND THE LOW LEVEL MOISTURE TRANSPORT GETS GOING AFTER SUNSET AND INTERSECTS THE WAVE. THE MOISTURE TRANSPORT IS NOT OVERLY STRONG TONIGHT BUT BOTH THE NAM AND GFS INDICATE IT WILL BE RIGHT INTO THE FORECAST AREA. AN AREA OF ELEVATED CAPE WILL REMAIN OVER THE AREA...ESPECIALLY ACROSS THE WEST THROUGH THE NIGHT. THE NAM SHOWS BETWEEN 500 AND 1000 J/KG ABOVE 1 KM. PRECIPITABLE WATERS RISE TO 1.75 INCHES OR HIGHER SO THE CONVECTION SHOULD PUT DOWN SOME DECENT RAINFALL AMOUNTS. 09Z SREF MEANS INDICATE PROBABILITIES OF 50 TO 70 FOR TONIGHT AND ACCORDINGLY HAVE RAISED THE POPS TO LIKELY FOR MOST OF THE AREA AFTER 06Z. THE ACTIVITY IS EXPECTED TO STILL BE ONGOING OR VERY NEAR THE SOUTHWEST PORTIONS OF THE FORECAST AREA MONDAY MORNING. RAISED POPS TO LIKELY FOR LOCATIONS IN AND AROUND KCCY. MOST OF THE ACTIVITY IS THEN EXPECTED TO SHIFT SOUTHWEST OUT OF THE AREA DURING THE AFTERNOON AND SUBSIDENCE BEHIND THE WAVE SHOULD BE ENOUGH TO DRY THINGS OUT. HOWEVER...THE NAM STILL HAS A WEAK SHORT WAVE TROUGH AT 700 MB COMING OVER THE TOP OF THE RIDGE. THIS COULD BE THE WEAK WAVE CURRENTLY LOCATED NEAR LAKE WINNIPEG SO WILL NOT TOTALLY DROP THE POPS FOR THE AFTERNOON...BUT DID LOWERED THEM ACROSS THE ENTIRE FORECAST AREA. STILL EXPECT TO SEE PLENTY OF CLOUD DEBRIS THROUGH MUCH OF THE DAY AND WITH A GOOD CHANCE OF RAIN YET IN THE MORNING...LOWERED TEMPERATURES QUITE A BIT FOR MONDAY. LONG TERM...WEDNESDAY THROUGH SUNDAY MEDIUM RANGE MODELS HAVE COME INTO VERY GOOD AGREEMENT WITH THE HANDLING OF THE CUT OFF LOW OVER THE EASTERN PART OF THE COUNTRY. MODELS NOW ARE INDICATING A MORE AMPLIFIED PATTERN WITH THE THIS LOW THROUGH THE PERIOD KEEPING THE AREA IN A NORTHWEST FLOW PATTERN. THE SHORT WAVE TROUGH AND SURFACE COLD FRONT SHOWING YESTERDAY TO BE COMING ACROSS THE AREA FOR THE UPCOMING WEEKEND NOW LOOKS TO BE FASTER POSSIBLY CROSSING THE AREA AS EARLY AS THURSDAY NIGHT. NOT QUITE READY TO JUMP TO THIS QUICKER SOLUTION YET BUT WILL TREND TOWARD IT AND INDICATE THE FRONT COMING ACROSS FRIDAY. THIS LEADS TO MOVING THE POPS FORWARD IN TIME STARTING THURSDAY NIGHT AND ENDING FRIDAY NIGHT OR SATURDAY. WITH THE MORE AMPLIFIED FLOW...THE HEAT UNDERNEATH THE UPPER LEVEL RIDGE LOOKS TO STAY WEST OF THE FORECAST AREA AND HAVE CONTINUED A DOWNWARD TREND IN THE TEMPERATURES WITH MAINLY 80S AND A FEW 90S. AVIATION...A 500 MB SHORTWAVE TROUGH WAS DROPPING SOUTHEAST ACROSS THE REGION THIS AFTERNOON...CONTINUING TO SPARK AREAS OF SHOWERS/STORMS ACROSS PARTS OF MN/NORTHWEST WI. DEVELOPMENT CONTINUES DESPITE THE DECREASE IN THE LOW LEVEL JET/MOISTURE TRANSPORT. MODELS HAVING A DIFFICULT TIME GRASPING THE PARTICULARS FOR THE PCPN THREAT...BUT THE OVERALL TREND IS TO INCREASE THE AREAL COVERAGE OF SHRA/TS TONIGHT AS THE MOISTURE TRANSPORT AND 850 MB JET INCREASES...AND THIS LOOKS REASONABLE. THE ACTIVITY SHOULD EXIT TO THE SOUTH BY MON MORNING...WITH A FRONT THEN INTRUDING UPON THE REGION. THIS FRONT COULD SPARK MORE SHRA/TS ON MONDAY...ALTHOUGH DEBRIS CLOUDS FROM THE OVERNIGHT PCPN WILL LIMIT THE INSTABILITY INITIALLY. WILL KEEP MENTION OF VCSH/VCTS FOR TONIGHT...AS TIMING CONFIDENCE ISN/T HIGH ENOUGH FOR A PREDOMINANT OR TEMPO WORDING. CONDITIONS LOOK TO STAY MOSTLY VFR...WITH SOME PERIODS OF MVFR POSSIBLE OVERNIGHT. ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. $$ SHORT/LONG TERM...04 && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 359 AM CDT SUN JUL 22 2007 .DISCUSSION...FCST FOCUS IS ON RESOLVING PCPN CHCS TNGT/MONDAY WITH ENERGY RIDING SOUTH ON ERN PERIPHERY OF UPPER RIDGE. WATER VAPOR ANIMATION CLEARLY SHOWS THE FLOW AROUND THE UPPER RIDGE AXIS...WHICH RUNS ROUGHLY FROM NEBRASKA NORTHEAST INTO NW WI. DECENT WAA AND MOIST ADVECTION COMBINED WITH A WEAK H5 SHORT WAVE HAS BLOSSOMED CONVECTION ACRS SE ND AND NE SD...WHICH IS FURTHER SW THAN WHAT MODEL QPF SUGGESTS. THE NAM AND TO A LESSER EXTENT THE GFS DEVELOP A HUGE CONVECTIVELY INDUCED VORT CENTER FROM THIS CONVECTION AND DRIVES IT SOUTH FROM MN INTO ERN IA TODAY. THIS LOOKS OVERDONE. ACTUALLY THE NGM AND RUC VORT PATTERN LOOKS BETTER. IN THE LOW LEVELS H8 WAA UNDERWAY WITH DECENT BAROCLINICITY SHOWING UP TNGT INTO MONDAY. H8 MOIST ADVECTION MOST PRONOUNCED INTO WRN CWA WITH THE EAST STILL STRONGLY INFLUENCED BY THE DRY HIGH. SREF AND GFS ENSEMBLE POPS SHOWING THE BEST CHCS OF SEEING ANY QPF WOULD BE IN THE WRN CWA TNGT/MONDAY...PRETTY MUCH IN LINE WITH OUR GOING GRIDS. AS FOR MONDAY THE MODELS ARE STILL SHOWING WEAK AND MAINLY SHEARED OUT VORT AXES STRETCHING NE TO SW BETWEEN THE UPPER RIDGE. BUFFY SOUNDINGS SHOW THE ERN CWA MUCH TOO DRY AND STABLE TO SUPPORT PCPN...SO KEEPING THE DRY LOOK THERE STILL SEEMS REASONABLE. MODELS SHOWING UPPER RIDGE AXIS TO OUR NW AND RETROGRADING UPPER LOW TO OUR SE IN THE TUES THRU THURS TIME FRAME. OVERALL LOOKS DRY DURG THIS PERIOD. CORE OF HOTTEST AIR WITH THIS SCENARIO LOOKS TO BE OFF TO OUR NW. 22/00Z GFS AND ECMWF BOTH CONTINUE THE TREND OF RETOGRADING THE ERN UPPER LOW. THE CANADIAN MODEL... WHICH HAS HAD THE MOST RUN TO RUN CONSISTENCY WITH THE RETROGRESSION...SHOWS THE CENTER OF THE UPPER LOW ACRS LAKE MI ON 12Z THU...THO OTHER MODELS HAVE THE UPPER LOW TOO FAR SE TO HAVE AN IMPACT ON SENSIBLE WX. FOR NOW WILL KEEP THURSDAY DRY. && 10 .AVIATION...LARGE SURFACE HIGH CENTERED OVER THE GREAT LAKES. VFR CONDITIONS EXCEPT FOR ISOLATED MVFR/IFR VSBYS IN FOG TIL 14Z...ESPECIALLY IN THE WISCONSIN RIVER VALLEY. SCATTERED FAIR WEATHER CUMULUS AROUND 4 THSD FT EXPECTED THIS AFTN. && .MKX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 152 AM MDT TUE JUL 24 2007 .DISCUSSION...CENTER OF 500 MB HIGH WILL DRIFT SOUTHWEST INTO CENTRAL COLORADO THE NEXT 48 HOURS. THIS WILL PLACE THE FORECAST AREA IN GENERAL SUBSIDENCE WITH WARM TEMPERATURES IN THE MID LEVELS. THOUGH SURFACE DEW POINTS WILL REMAIN DECENT AND SURFACE BASED CAPES WILL BE AROUND 750 J/KG...CONVECTIVE INHIBITION WILL BE HIGH THIS AFTERNOON AND WEDNESDAY AFTERNOON. THIS...PLUS THE LACK OF ANY SIGNIFICANT LOW LEVEL FOCUSING...WILL PREVENT CONVECTION THE NEXT 48 HOURS. 850 MB TEMPERATURES WILL BE AROUND 28 DEGREES CELSIUS...SO EXPECT TEMPERATURES TO BE CLOSE TO WHAT OCCURRED MONDAY AFTERNOON. SOME VERY WEAK WARM AIR ADVECTION WILL OCCUR 36-48 HOURS...AND WILL WARM TEMPERATURES A FEW DEGREES WEDNESDAY AFTERNOON. NAM AND GFS ARE CONSISTENT WITH BRINGING A SHORTWAVE THROUGH THE 500 MB RIDGE THURSDAY AFTERNOON/NIGHT. GFS APPEARS TOO STRONG WITH THE FEATURE GIVEN THE STRENGTH OF THE RIDGE. NAM DEPICTS SHORTWAVE OVER SOUTHEAST WYOMING/NORTHEAST COLORADO BY 18Z THURSDAY AND DEVELOPS CONVECTION OVER THE FRONT RANGE. AS WAVE MOVES SOUTHEAST DURING THE LATE AFTERNOON/EVENING...CONVECTION WILL FOLLOW. THIS APPEARS REASONABLE...AND WILL CONTINUE WITH SCATTERED THUNDERSTORMS ESPECIALLY THURSDAY EVENING. ASSOCIATED COLD FRONT WILL MOVE ACROSS THE FORECAST AREA THURSDAY AFTERNOON BRINGING SLIGHTLY COOLER TEMPERATURES AND SWITCHING SURFACE WINDS TO THE NORTH. NO CHANGES WERE MADE TO THE EXTENDED PARTS OF THE FORECAST. && .AVIATION...HIGH RESOLUTION RUC MODEL DEPICTS VISIBILITIES DROPPING TO 5 MILES IN BR JUST EAST OF KMCK EARLY THIS MORNING. CURRENT SATELLITE IMAGERY DOES NOT INDICATE FOG DEVELOPING ACROSS SOUTHWEST NEBRASKA...HOWEVER...SO WILL KEEP VFR CONDITIONS FORECAST THERE. OTHERWISE...EXPECT HIGH BASED CUMULUS THIS AFTERNOON...MAINLY AROUND 7500 FEET AGL...AT KGLD AND KMCK TERMINALS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ MENTZER ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 315 AM EDT TUE JUL 24 2007 .SHORT TERM (TODAY AND TONIGHT)... FCST CONCERN DURING THE SHORT TERM CENTERS ON TSTM CHANCES THIS AFTERNOON AND EVENING ASSOCIATED WITH UPR LOW...WHICH CURRENTLY IS CENTERED NEAR THE OH-WV STATE BORDER. THIS LOW IS SPINNING HIGH AND SOME MID-LEVEL MOISTURE SWWD INTO OH VALLEY...BUT RADAR SHOWS NO PRECIP ACROSS CNTRL KY AND S-CNTRL IN AT THIS TIME. NAM...GFS...AND RUC MODELS FCST LITTLE OVERALL MOVEMENT OF UPR LOW THRU THIS EVENING. A MESO SFC ANALYSIS AT 06Z SHOWED A SFC TROF ALIGNED SW-NE OVER CNTRL KY. CONVECTION ON MONDAY AFTERNOON OCCURRED MAINLY S OF THIS AXIS ALONG AN APPARENT OUTFLOW BOUNDARY AND IN CONJUNCTION WITH TERRAIN OVER SERN KY AND ERN TN. WITH UPR LOW NOT MOVING ALL THAT MUCH TODAY AND WITH CURRENT WATER VAPOR IMAGERY NOT SHOWING ANY DEFINITIVE SHORTWAVES ROTATING AROUND LOW...FEEL THAT ISOLD TO SCT TSTMS THIS AFTERNOON AND EVENING WILL BE CONFINED TO E-CNTRL AND ERN PART OF S-CNTRL KY...ROUGHLY ALONG AND E OF A FFT TO GLASGOW LINE. THIS AXIS WILL BE ALONG AND S OF WEAK SFC BOUNDARY...AND IT ALSO ALIGNS WITH QPF AND INSTABILITY AXIS FROM GFS AND RUC. ON THE OTHER HAND...NAM APPEARS TO SHOW ITS TYPICAL HIGH BIAS OF SFC DEPWTS AND RESULTING GREATER SFC BASED INSTABILITY...THEREBY ALLOWING SCT CONVECTION TO OCCUR FARTHER W OVER CNTRL KY. AS WAS THE CASE YESTERDAY...BEST TSTM COVERAGE SHOULD AGAIN OCCUR OVER ERN/SERN KY THIS AFTERNOON. ANY TSTM ACTIVITY SHOULD DISSIPATE TONIGHT OVER ERN PARTS OF CNTRL KY. CONTINUED MID/HIGH LEVEL MOISTURE WILL KEEP SKY PARTLY CLOUDY. MOS GUIDANCE TEMPS TODAY AND TONIGHT ARE WITHIN A FEW DEGREES OF EACH OTHER AND SEEM REASONABLE. TWF .LONG TERM (WEDNESDAY THRU MONDAY)... MEANDERING UPR LOW ACRS THE ERN OH VLY AT THE START OF THIS PERIOD FCST BY BOTH NAM/GFS TO WOBBLE NWWD TO THE LOWER GREAT LAKES THU WHILE FILLING. AFTERWARD...LOW OPENS TO A TROF FROM THE GREAT LAKES INTO THE OH VLY (NAM) OR TRANSITIONS ENE WITH TROF FARTHER EAST ACRS THE ERN OH VLY FRI (GFS). THE GFS SOLUTION IS IN BETTER AGREEMENT WITH THE NEW RUNS OF THE ECMWF AND ENSEMBLE MEANS AND WILL BE FOLLOWED FOR THE THU/FRI PERIOD. BOTH MODELS SHOW WEAK SFC/LO LEVEL SLY FLO/CONTD MSTR TRANSPORT INTO OUR FA WED...HOWEVER...LITTLE IN THE WAY OF FORCING...OTHER THAN POSITIONING OF UPR LO/STEEPER LAPSE RATES...AS WEAK SFC TROF BECOMES DIFFUSE. OUR CURRENT FCST OF 20 POPS WRN FA AND 40 ERN AREAS LOOK O.K. BASED ON DEEPER MOISTURE PROGGED EAST BY THE MODELS...WILL HOLD OFF TIL AFTN PER STEEPENING LAPSE RATES. WILL CONTINUE A DIURNAL DOWNWARD TREND WED NIGHT...KEEPING POPS ONLY THRU THE EVENING. FROM THU ON...WILL GENERALLY FOLLOW GFS/ENSEMBLE MEANS/ECMWF WITH A NLY COMPONENT OF UPR LOW MOVEMENT RESULTING IN A DECREASING POP TREND FOR ALL EXCEPT OUR NRN/NERN FA...CLOSEST TO PROGGED UPR LO POSITION. THIS CONSISTENT WITH HPCS PLACEMENT OF HIER QPF FOR THU AND ENSEMBLE MEANS/ECMWF PLACEMENT OF DEEPEST MOISTURE FRI. SCT TSTMS TO REMAIN IN THE FCST FOR THE WEEKEND AS A CDFNT REACHES THE UPR OH VLY SAT AND OUR FA EARLY SUN...EXITING OUR SRN FA SUN NGT. WILL KEEP TEMPS PRETTY MUCH WHERE THEY ARE NOW FOR THIS LONG RANGE PD AFTER EXAMINING MEX MOS. DK && .AVIATION (06Z TAFS)... UPR LOW CURRENTLY SPINNING NEAR OH-WV BORDER. DEFINITIVE PLUME OF HIGH AND SOME MID LEVEL MOISTURE MOVING SWWD ON BACK SIDE OF LOW INTO CNTRL KY. AT 05Z...ALL TAF SITES HAD VFR CONDITIONS AND THIS TREND WILL CONTINUE FOR MUCH OF FCST PERIOD. ONLY EXCEPTION COULD BE BRIEF MVFR VSBYS AT LEX AROUND AND JUST AFTER SUNRISE WITH SOME LIGHT FOG OR HAZE. ALSO FOR TUE AFTERNOON...MARGINAL INSTABILITY WILL WORK A BIT FARTHER N AND W OVER ERN KY COMBINED WITH WEAK LOW-LEVEL BOUNDARY ALREADY IN PLACE OVER CNTRL KY. MODELS SUGGEST THAT ISOLD TO SCT MID-LATE AFTERNOON CONVECTION SHOULD DEVELOP OVER ERN KY...AND A COUPLE CELLS COULD AFFECT AROUND LEX AREA DURING LATE AFTERNOON...THUS HAVE INCLUDED VCTS AT LEX...BUT NOT AT SDF OR BWG AT THIS TIME WHERE AIR MASS APPEARS IT WILL BE A BIT MORE STABLE. TWF && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 443 AM EDT TUE JUL 24 2007 .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE HIGH TEMPERATURES THIS AFTERNOON. WATER VAPOR IMAGERY AND RUC SHOWING A CLOSED LOW OVER EASTERN OHIO AND LARGE HIGH CENTERED OVER SOUTH DAKOTA BLANKETING MUCH OF THE NORTHERN PLAINS. A RIDGE EXTENDING EAST FROM THIS HIGH STRETCHES ACROSS LAKE SUPERIOR INTO EAST CENTRAL ONTARIO. WEAK SHORTWAVES TRAVERSING THE RIDGE ARE OVER NORTHERN LOWER MICHIGAN AND OVER THE KFGF AREA. SURFACE ANALYSIS DEPICTS A BROAD HIGH COVERING EAST CENTRAL CONUS...A WEAK LOW OVER WESTERN SOUTH DAKOTA...AND A COLD FRONT OVER CENTRAL CANADA. NUMEROUS SHOWERS AND THUNDERSTORMS WERE OCCURRING OVER THE HIGH PLAINS DUE TO INCREASED MOISTURE AND UPSLOPE CONDITIONS IN THAT AREA. A LARGE RIDGE OFF THE EAST COAST WILL KEEP THE MID LEVEL OHIO LOW AND THE NORTHERN PLAINS RIDGE FROM MOVING VERY MUCH TODAY. FRONTOGENESIS OVER SASKATCHEWAN SUPPORTS THE DEVELOPMENT OF A LOW OVER NORTHEAST MONTANA AND A COLD FRONT OVER SOUTH CENTRAL CANADA. ANTI-CYCLONIC FLOW AROUND THE EASTERN CONUS HIGH WILL CONTINUE TO DRAW WARM MOIST LOW LEVEL AIR INTO THE FORECAST AREA TODAY. GFS SHOWING HIGHER SURFACE-700MB RH WILL BE ALONG THE LAKE MICHIGAN SHORE. LAKE BREEZES SHOULD SET UP THIS AFTERNOON UNDER MOSTLY CLEAR SKIES AND LIGHT WINDS. FORECAST SOUNDINGS SUGGEST MLCAPE VALUES COULD EXCEED 1000 J/KG OVER CENTRAL AND EAST COUNTIES OF CWA. INCREASED RH AND LITTLE MORE INSTABILITY OVER THE SOUTHERN COUNTIES COULD PRODUCE SOME SHOWERS AND THUNDERSTORMS TRIGGERED BY LAKE BREEZE CONVERGENCE...SO WILL KEEP A MEAN OF SLIGHT CHANCE OF SHOWERS OVER THE SOUTHERN COUNTIES. MOSTLY SUNNY SKIES WILL PREVAIL. THE TRAJECTORY FORECAST SUGGESTING DRAWING THE AIR MASS OVER WISCONSIN YESTERDAY INTO THE FORECAST AREA. LOOKING FOR TEMPERATURES IN THE MID 80S ACROSS THE REGION THIS AFTERNOON. WINDS WILL BE LIGHT SO CONDITIONS ARE FAVORABLE FOR LAKE BREEZES SO TEMPERATURES NEAR THE LAKE SHOULD REMAIN ONLY IN THE MID 70S. THE MID LEVEL LOW OVER OHIO WILL STILL SHOW LITTLE MOVEMENT THROUGH TONIGHT AS WILL THE RIDGE OVER THE LAKE SUPERIOR. A WEAK SHORTWAVE TRAVERSING THE RIDGE WILL SLIDE THROUGH THE FORECAST AREA. THE SURFACE LOW OVER MONTANA WILL LIFT INTO SOUTHERN MANITOBA DRAGGING A COLD FRONT WITH IT. SOUTHWEST FLOW OVER CENTRAL PLAINS WILL CONTINUE TO BRING PLENTY OF WARM MOIST AIR INTO THE AREA. OVERNIGHT LOWS SHOULD BE JUST A LITTLE WARMER THAN THIS MORNINGS. THE MID LEVEL LOW WILL LIFT INTO THE LOWER GREAT LAKES ON THURSDAY AND REMAIN OVER THAT AREA THROUGH FRIDAY. THE RIDGE OVER THE NORTHERN PLAINS WILL BUILD. WEAK SHORTWAVE MIGRATING BETWEEN THESE TWO SYSTEM WILL PASS THROUGH THE AREA. SURFACE LOW AND ASSOCIATED COLD FRONT WILL SHIFT INTO NORTHERN MINNESOTA BY THURSDAY MORNING AND THROUGH THE FORECAST AREA THURSDAY NIGHT. SHORTWAVE ENERGY AND ISENTROPIC ASCENT ASSOCIATED WITH THE FRONTAL SYSTEM WILL GENERATE A CHANCE OF SHOWERS AND THUNDERSTORMS OVER THE AREA STARTING THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. DRY AIR SHOULD RETURN TO THE AREA BEHIND THE FRONTAL SYSTEM. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... CONDITIONS REMAIN FAVORABLE FOR SOME FOG FORMATION LATER TONIGHT AT KCMX WHERE LACK OF CLOUDS WILL ALLOW BETTER RADIATIONAL COOLING WITH LOW-LEVEL MOISTURE TRAPPED UNDER DRIER/WARMER LAYER ALOFT. VSBY MAY DROP INTO THE IFR RANGE LATE. LINGERING LOW-LEVEL MOISTURE SHOULD LEAD TO SOME DIURNAL CU FORMATION ON TUE BUT GENERALLY EXPECT DECK TO BE SCT. MDLS RH FCST SUGGESTS THAT THE 040-050 CIGS AT KSAW MAY LINGER INTO TUE TIL 900-700 MB DRYING MOVES IN LATER IN THE DAY. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... ONCE AGAIN...FOG IS A FCST CHALLENGE FOR THE EARLY MORNING FCST. SHIP JUST OFF COPPER HARBOR INDICATED VIS OF 2 1/2NM AT 03Z. OTHERWISE...THERE HAVE BEEN NO INDICATIONS OF FOG FROM THE FEW SHIP OBS SINCE THEN. UPON VERY CLOSE EXAMINATION OF SATELLITE IMAGERY... THERE ARE HINTS THAT FOG MAY BE PRESENT OVER THE NORTHERN PART OF THE LAKE...GENERALLY ALONG A LINE FROM JUST N OF THE KEWEENAW TO THE EASTERN LAKE BUOY. HAVE THUS OPTED TO MENTION PATCHY FOG FOR TODAY. AFTER SUNRISE...VIS SATELLITE IMAGERY WILL REVEAL WHETHER FOG IS PRESENT ANYWHERE OVER THE LAKE. OTHERWISE...WINDS UNDER 20KT SHOULD PREVAIL THRU THE FCST PERIOD. HIGHEST WINDS WILL OCCUR IN ASSOCIATION WITH A TROF CROSSING LAKE SUPERIOR THU NIGHT/FRI MORNING. SE TO S WINDS AHEAD OF TROF MAY INCREASE TO AROUND 20KT OVER ERN LAKE SUPERIOR WED NIGHT/THU. AFTER TROF PASSAGE...NRLY WINDS MAY REACH 20KT FOR A TIME OVER MUCH OF THE LAKE. .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DISCUSSION...DLG MARINE...ROLFSON AVIATION...JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 340 AM CDT TUE JUL 24 2007 .DISCUSSION... EXTENSIVE CLOUDINESS BLANKETS WEST CENTRAL WI AND PORTIONS OF EAST CENTRAL AND SOUTH CENTRAL MN EARLY THIS MORNING. THE CLOUDINESS HAS ACTUALLY INCREASED IN COVERAGE OVER THE PAST FEW HOURS. 310K THETA SURFACE SHOWING UPGLIDE FROM THE NORTH ACROSS NORTHERN AND WEST CENTRAL WI WITH SOME ADIABATIC OMEGA. MODEL GUIDANCE INDICATING RATHER EXTENSIVE LAYER MOISTURE BELOW 700 MB THROUGH THE DAY. HAVE CUT BACK ON HIGHS OVER WEST CENTRAL WI...THE MSP METRO AREA AND SOUTHWARD ALONG I-35. IF THE CLOUDS STAY...CURRENT HIGH TEMPERATURE FORECAST WILL BE TOO HIGH...IF THE CLOUDS GO... FORECAST WILL BE TOO LOW. TO OUR NORTHWEST...CONVECTIVE COMPLEX CONTINUES TO GROW OVER NE ND. SOME ACTIVITY STARTING TO GET SOUTH OF KFGF ATTM. 850-300MB THICKNESS WOULD HEAD THE ACTIVITY TOWARD OUR NW CWA. 21Z SREF HAD A GOOD HANDLE ON THIS FEATURE. 03Z SREF MAINTAINS THE COMPLEX AND PUSHES IT TOWARD KDLH BY 21Z. THE THUNDERSTORMS ARE ALONG AND NORTH OF ABOUT +13 DEG C AT 700MB. THE RUC TRIES TO MAINTAIN +14 OVER WEST CENTRAL THROUGH CENTRAL MN THROUGH MIDDAY. PLANNING ON GOING DRY ATTM...BUT WILL HAVE TO KEEP AN EYE ON THIS FEATURE EARLY THIS MORNING. HIGHS TODAY FOR WESTERN MN LOOK TO AROUND 93 TO 95 DEGREES IF THIS COMPLEX STAYS AWAY. RAISED DEW POINTS ABOUT 2 DEGREES IN THE GRIDS FOR THE NEXT SEVERAL DAYS ALL AREAS. RESULTING HEAT INDEX VALUES IN THE 100-104 RANGE FOR WEST CENTRAL TODAY AND IN THE 104-107 RANGE ON WEDNESDAY. LITTLE CHANGE TO THE HIGHS FOR WEDNESDAY AND THURSDAY. ONE CHANGE IN THE FORECAST WAS WITH THE PRECIP FORECAST THURSDAY AND THURSDAY NIGHT. DIVIDED THE FORECAST INTO 6 HOUR WINDOWS AND INCREASE POPS INTO THE HIGH CHANCE CATEGORY...MAINLY OVER THE EASTERN AND SOUTHERN CWA. PRETTY GOOD AGREEMENT BETWEEN THE NAM/GFS AND 03Z SREF THAT A FROPA WILL OCCUR BY DAYBREAK FRIDAY. ONE TROUBLING FEATURE SEEN FOR LATE THURSDAY IS THAT PRECIPITABLE WATER VALUES INCREASE TO NEARLY 2.25 INCHES FOR MUCH OF OUR CWA ON BOTH THE NAM AND GFS WITH A 6 HOURLY INCREASE OF OVER HALF AN INCH. WHEN IT FINALLY RAINS...ITS GOING TO POUR. HIGH PRESSURE AND LOWER AFTERNOON HUMIDITY SPREADING IN FOR THE UPCOMING WEEKEND. .PREV DISCUSSION... /ISSUED 1226 AM CDT TUE JUL 24 2007/ AVIATION.../06Z TAF CYCLE/ MVFR CIGS REMAIN ACROSS WC WI THIS EVENING AND MODELS SUGGEST THIS TREND WILL CONTINUE THROUGH THE NIGHT INTO TUESDAY. QUESTION IS HOW FAR WEST TO BRING THIS CLOUD COVER AGAIN. WILL KEEP IT SCT AT MSP EARLY...BRINING IT BACK IN FOR THE DAY TUESDAY. MFVR-IFR VSBY IN FOG AND POSSIBLE STRATUS DEVELOPMENT IN AREAS SEEING MAINLY CLEAR CONDITIONS...ALTHOUGH GRADIENT IS INCREASING A BIT IN THE WEST. AFTER MORNING FOG...MID/HIGH LEVEL CLOUDS THE TRNED FOR WESTERN TAFS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ RAH/DWE mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 310 AM CDT TUE JUL 24 2007 .DISCUSSION...MCS IN NE ND ATTM AND ITS IMPACT ON THE NW QUAD OF THE FA THE CONCERN FOR THE SHORT TERM. 00Z MODELS ARE TOO FAR E WITH THE SHORT WAVE THAT IS MOVING THROUGH MOVING ALONG THE INTERNATIONAL BORDER. 06Z RUC ALSO OVERDOING IT...BUT HAS THE MCS WEAKENING BEFORE REACHING THE FA WITH NO PCPN. DID HOWEVER ADD A SMALL POP THIS MORNING FOR THE POSSIBILITY IT MAY MAKE IT THAT FAR E. OVER THE REST OF THE FA...SFC RIDGING COVERS THE AREA. LOWS CLOUDS AND FOG ARE DEVELOPING/SPREADING OVER THE FA. FOG ALSO A FACTOR OVER THE SOUTHERN HALF OF MN FA WITH MZH ALREADY AT 1/2 MILE. WILL MONITOR CLOSELY FOR DENSE FOG POTENTIAL EARLY. THE ND SHORT WAVE IS PROGGED TO DROP SEWD AND INTO THE FA TODAY. HOWEVER...MODELS ARE NOT GENERATING ANY QPF. WILL KEEP GRIDS RAIN FREE THIS AFTERNOON...BUT LOW CONFIDENCE. HOT AND HUMID CONDITIONS TODAY...APPARENT TEMPERATURE APPROACHES HEAT ADVISORY CRITERIA OVER CROW WING...SOUTHERN CASS AND AITKIN COUNTIES THIS AFTERNOON. NO HEADLINES ATTM...BUT WILL MENTION TO NEXT SHIFT. LITTLE CHANGE IN THE ATMOSPHERE OVER THE FA TONIGHT AND EXPECT PATCHY FOG TO DEVELOP AFTER MIDNIGHT AGAIN. UPPER LEVEL LOW THAT HAS BEEN AFFECTING THE E COAST WILL RETROGRADE INTO THE LOWER GREAT LAKES WEDNESDAY. MEANWHILE...A COLD FRONT WILL APPROACH FROM THE W AIDED BY AN UPPER LEVEL SHORT WAVE. MODELS DIFFER ON WHETHER THUNDERSTORMS WILL BREAK OUT IN NW WI IN THE AFTERNOON. WILL KEEP WITH PERSISTENCE AND NOT MENTION RAIN FOR NOW. APPROACHING SYSTEMS BEGIN TO CONVERGE ON THE FA WEDNESDAY NIGHT WITH THUNDERSTORMS DEVELOPING. TIMING AN ISSUE AT THIS POINT AND HAVE LEFT GRIDS AS IS. BETTER CHANCES FOR RAIN THURSDAY AND FRIDAY AS THE COLD FRONT PUSHES THROUGH. COOLER AND DRIER CONDITIONS EXPECTED FRIDAY NIGHT INTO MONDAY. && .AVIATION...ABUNDANT LOW LEVEL MOISTURE WILL CONTINUE TO RESULT IN AREAS OF MVFR/IFR CONDITIONS WITH FOG THROUGH EARLY MORNING. CONDITIONS SHOULD IMPROVE TO VFR ACROSS MUCH OF THE NORTHLAND BY MID MORNING WITH SCT-BKN MID LEVEL CU. HOWEVER...MVFR CIGS MAY PERSIST ACROSS PORTIONS OF NW WI THROUGH MID DAY. AREAS OF FOG LOOK TO REDEVELOP ACROSS THE ENTIRE FORECAST AREA LATE TONIGHT. && POINT TEMPS/POPS... DLH 90 64 90 64 / 10 10 10 10 INL 93 68 94 66 / 10 10 10 30 BRD 94 68 94 69 / 10 10 10 20 HYR 90 64 91 65 / 10 10 10 10 ASX 88 64 88 64 / 10 10 10 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. $$ GSF/LILES mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 204 AM EDT TUE JUL 24 2007 .SYNOPSIS... THE UPPER LEVEL /CUTOFF/ LOW JUST TO OUR SOUTH/WEST WILL DRIFT SLOWLY WEST AND NORTH THROUGH FRIDAY. THE WINDS CIRCULATING AROUND THE LOW WILL HELP TO BRING AN INCREASE IN MOISTURE TO THE REGION. SCATTERED SHOWERS AND AFTERNOON THUNDERSTORMS ARE POSSIBLE THROUGH THE REST OF THE WEEK. TEMPERATURES WILL RETURN TO NEAR NORMAL BY FRIDAY...AND THE HUMIDITY WILL ALSO INCREASE. && .NEAR TERM /THROUGH TODAY/... MCLEAR SKIES ACROSS THE REGION NOW WITH FOG DEVELOPING IN THE NORTH WEHERE RAIN FELL ON MON. WILL MONITOR FOR POSSIBLE DENSE FOG ADVSRY...BUT NO OBSERVING SITES ARE BELOW 1/4SM JUST YET. MANY ARE APPROACHING ZERO DEWPOINT DEPRESSIONS THOUGH. CLOUDS SHOULD ROTATE BACK IN FROM THE SOUTH SHORTLY...WITH HIGHEST COVERAGE OVER THE WESTERN MOUNTAINS LATER THIS MORNING. WE SHOULD ALSO SEE A FEW SHOWERS IN THERE...BUT MOST OF THE SHOWERS WILL WAIT UNTIL THE AFTERNOON TO DEVELOP. WILL KEEP MENTIONS OF THUNDER WITH THE UPPER LOW/S COOL POOL ALOFT SO CLOSE. THE ONLY PLACE THAT MAY STAY DRY LOOKS LIKE THE FAR NORTHEASTERN COUNTIES. WILL THEREFORE KEEP THE POPS BELOW 15 PCT THERE. MAXES SHOULD REMAIN SLIGHTLY BELOW NORMALS FOR THIS TIME OF YEAR...HOLDING IN THE MID 70S TO LOWER 80S. && .SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/... NAM AND GFS SOLUTIONS ARE ALMOST IDENTICAL THROUGH 60 HRS WITH THEIR PROJECTED POSITION AND DEPTH/STRENGTH OF THE CUTOFF LOW. THIS LENDS TO A BIT MORE CONFIDENCE IN THE FORECAST DETAILS. BUT SHOWERY PRECIP IS NEVER EASY TO PINPOINT. DIURNAL SHRA/TSRA SHOULD DIE DOWN AFTER SUNSET...BUT AS WITH OVER WRN VA...WHERE THERE ARE A FEW SHOWERS THAT AREN/T FOLLOWING THIS CONVENTION...WE MAY SEE SOME LINGER THROUGH THE NIGHT TONIGHT. MINS SHOULD BE HIGHER THAN TONIGHT WITH A BIT MORE CLOUD COVER IN PLACE. IT WILL STILL NOT BE VERY MUGGY WITH DEWPOINTS EXPECTED TO ONLY BE NEAR 60 IN THE SUSQ VALLEY AND STILL IN THE 50S IN THE MOUNTAINS. WILL GO WITH MINS IN THE 50S TO L60S. WEDNESDAY LOOKS LIKE WE COULD HAVE A BIT BETTER/WIDER COVERAGE TO THE SHOWERS - THAN TODAY AT LEAST. WILL UP POPS A BIT TO NEAR 60/LIKELY FOR THE SW AND 50 OR SO FOR THE REST OF THE WESTERN AND CENTRAL COUNTIES...CLOSER TO THE UPPER LOW. WILL ALSO KEEP TEMPS DOWN A DEG OR TWO FROM TODAYS EXPECTED MAXES. AGAIN...THE EASTERN CITIES LOOK TO HAVE THE BEST CHANCE TO STAY DRY. WILL NOT TOTALLY ELIMINATE POPS BUT KEEP THEM LOWEST OVER THAT WAY. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... THE CUTOFF UPPER LOW WILL RETROGRADE SLIGHTLY TO THE WEST OVER OHIO BY MID WEEK...AND NORTHWARD INTO THE GREAT LAKES FOR THE END OF THE WEEK. SHORT WAVES ROTATING AROUND THE FEATURE WILL TAP INTO SOME INCREASING MOISTURE TO SET OFF SCATTERED SHOWERS AND AFTERNOON THUNDERSTORMS INTO FRIDAY. THE LOW OPENS UP INTO A WAVE ON FRIDAY WHICH WILL STILL KEEP THE THREAT FOR SHOWERS INTO THE WEEKEND WHEN A NORTHERN STREAM TROUGH CAPTURES THIS FEATURE AND SLOWLY PULLS MOST OF THE MOISTURE TO THE EAST COAST. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... LATEST SFC PRES ANALYSIS COURTESY OF THE RUC SHOWS LOW PRES MOVG NWD INTO UPSTATE NY WITH A MESO-HIGH SITUATED ACROSS THE LAUREL HIGHLANDS. RESIDUAL LOW/MID CLOUD COVER WILL EXIT NRN PA WITHIN THE NEXT FEW HOURS WITH LOCALLY DENSE FOG AT BFD/IPT AS LLVL MSTR FROM YESTERDAYS RAINFALL BECOMES TRAPPED BLW NOCTURNAL INVERSION. FOG WILL DISSIPATE SHORTLY AFT SUNRISE AS BLYR BECOMES WELL-MIXED. VFR WILL BE THE DOMINATE FLIGHT CAT TODAY. ONCE THE INVERSION MIXES OUT...LOOK FOR SLY SFC WNDS 4-8KTS. MAIN AVN CONCERN WILL BE CLOSE PROXIMITY OF MID/UPPER LVL LOW OVER THE UPR OH VLY.../AND ITS ASSOC COOL POOL ALOFT/...WHICH WILL SUPPORT SCT-BKN CU DEVELOPMENT DURING THE AFTN HOURS. AS DESTABILIZATION CONTINUES INTO THE MID/LATE AFTN...EXPECT SOME TCU WITH SCT TSRA AND LCL MVFR-IFR PSBL AT JST/AOO/UNV/BFD WITH MORE ISOLD/WDLY SCT CONVECTION FURTHER EAST /FURTHER AWAY FROM THE COOL POOL ALOFT/. COINCIDING WITH THE DIURNAL CYCLE...CU SHOULD BEGIN TO CRUMBLE CLOSE TO SUNSET WITH SCT-BKN MID LVL CLOUD DEBRIS REMAINING. DUE TO THE PERSISTENCE OF THE UPPER LOW...CANT RULE OUT THE POSSIBILITY FOR SCATTERED CONVECTIVE SHOWERS WED AFTERNOON. THIS IS A TREND THAT CAN BE EXPECTED TO CONTINUE THROUGH THE REST OF THE WEEK. SINCE NONE OF THE SHOWERS WILL BE ORGANIZED...EXPECT PRIMARILY VFR CONDITIONS WITH ISOLD MVFR/IFR IN THE AFTERNOON/EVENING. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO NEAR TERM...DANGELO SHORT TERM...DANGELO LONG TERM...DANGELO/TYBURSKI AVIATION...STEINBUGL pa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 125 AM EDT TUE JUL 24 2007 .SYNOPSIS... A LOW PRESSURE SYSTEM ALOFT WILL HELP FUNNEL MOISTURE INTO THE REGION. SCATTERED SHOWERS AND AFTERNOON THUNDERSTORMS ARE POSSIBLE THROUGH THE REST OF THE WEEK. TEMPERATURES WILL RETURN TO NEAR OR SLIGHTLY ABOVE NORMAL BY FRIDAY ALONG WITH AN INCREASE IN HUMIDITY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... IR IMAGERY SHOWS MCLEAR SKIES ACROSS SOUTHERN PA WITH RESIDUAL CLOUD COVER NOW LIFTING NORTH OF I-80. RECENT RAIN...LIGHT WIND AND CLEARING SKIES SHOULD YIELD AREAS OF DENSE FOG DURING THE PREDAWN HOURS ACROSS NORTHERN PA...WHERE BTWN 0.25 AND 0.50 INCHES OF RAIN FELL YESTERDAY. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/... AREAS OF EARLY FOG WILL LIKELY BURN OFF TO MSUNNY SKIES FOR A TIME DURING MID AM TUESDAY. HOWEVER...COOL TEMPS ALOFT IN VICINITY OF UPPER LO WILL RESULT IN ABUNDANT CU BY AFTN. BEST CHC OF AFTN SHWRS/TSTMS WILL BE OVER THE LAUREL HIGHLANDS...CLOSEST TO UPPER LO OVR SE OHIO. MODEL 850 TEMPS SUPPORT HIGHS FROM M70S ALLEGHENY PLATEAU...TO THE L80S SUSQ VALLEY. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... A CUTOFF UPPER LOW WILL RETROGRADE WEST OVER OHIO BY MID WEEK. SHORT WAVES ROTATING AROUND THE FEATURE WILL TAP INTO SOME INCREASING MOISTURE TO SET OFF SCATTERED SHOWERS AND AFTERNOON THUNDERSTORMS INTO FRIDAY. THE LOW OPENS UP INTO A WAVE ON FRIDAY WHICH WILL STILL KEEP THE THREAT FOR SHOWERS INTO THE WEEKEND WHEN A NORTHERN STREAM TROUGH CAPTURES THIS FEATURE AND SLOWLY PULLS MOST OF THE MOISTURE TO THE EAST COAST. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... LATEST SFC PRES ANALYSIS COURTESY OF THE RUC SHOWS LOW PRES MOVG NWD INTO UPSTATE NY WITH A MESO-HIGH SITUATED ACROSS THE LAUREL HIGHLANDS. RESIDUAL LOW/MID CLOUD COVER WILL EXIT NRN PA WITHIN THE NEXT FEW HOURS WITH LOCALLY DENSE FOG AT BFD/IPT AS LLVL MSTR FROM YESTERDAYS RAINFALL BECOMES TRAPPED BLW NOCTURNAL INVERSION. FOG WILL DISSIPATE SHORTLY AFT SUNRISE AS BLYR BECOMES WELL-MIXED. VFR WILL BE THE DOMINATE FLIGHT CAT TODAY. ONCE THE INVERSION MIXES OUT...LOOK FOR SLY SFC WNDS 4-8KTS. MAIN AVN CONCERN WILL BE CLOSE PROXIMITY OF MID/UPPER LVL LOW OVER THE UPR OH VLY.../AND ITS ASSOC COOL POOL ALOFT/...WHICH WILL SUPPORT SCT-BKN CU DEVELOPMENT DURING THE AFTN HOURS. AS DESTABILIZATION CONTINUES INTO THE MID/LATE AFTN...EXPECT SOME TCU WITH SCT TSRA AND LCL MVFR-IFR PSBL AT JST/AOO/UNV/BFD WITH MORE ISOLD/WDLY SCT CONVECTION FURTHER EAST /FURTHER AWAY FROM THE COOL POOL ALOFT/. COINCIDING WITH THE DIURNAL CYCLE...CU SHOULD BEGIN TO CRUMBLE CLOSE TO SUNSET WITH SCT-BKN MID LVL CLOUD DEBRIS REMAINING. DUE TO THE PERSISTENCE OF THE UPPER LOW...CANT RULE OUT THE POSSIBILITY FOR SCATTERED CONVECTIVE SHOWERS WED AFTERNOON. THIS IS A TREND THAT CAN BE EXPECTED TO CONTINUE THROUGH THE REST OF THE WEEK. SINCE NONE OF THE SHOWERS WILL BE ORGANIZED...EXPECT PRIMARILY VFR CONDITIONS WITH ISOLD MVFR/IFR IN THE AFTERNOON/EVENING. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT/TYBURSKI NEAR TERM...DEVOIR/FITZGERALD/STEINBUGL SHORT TERM...DEVOIR LONG TERM...DANGELO/TYBURSKI AVIATION...STEINBUGL pa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 1045 AM EDT TUE JUL 24 2007 .SYNOPSIS... HIGH PRESSURE OVER THE WESTERN ATLANTIC WILL BEGIN TO SHIFT EAST OVER THE ATLANTIC TODAY. A WEAK TROUGH WILL LIFT NORTH TOWARD THE AREA TONIGHT...WITH ATLANTIC HIGH PRESSURE RE-ESTABLISHING ITSELF THROUGH THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... HIGH PRESSURE OVER US TODAY WILL BEGIN TO SHIFT EAST ALLOWING A SETUP FOR ONSHORE FLOW AND THE CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON MAINLY OVER PORTIONS OF SOUTHEAST GEORGIA. MADE A FEW CHANGES TODAY FOR THE SHORT TERM. IT APPEARS CLOUD COVER WILL MAKE ITS WAY INTO OUR SOUTHERN ZONES BASED ON VIS SAT IMAGERY. SOUNDINGS ALSO INDICATE AN INCREASE IN MID LVL MOISTURE DURING THE AFTERNOON...WHICH IS DEPICTED IN CURRENT WATER VAPOR IMAGERY AS WELL. LATEST RUC PUTS OUR CWA UNDER A FAVORABLE QUADRANT OF A H25 JET...WHICH SUGGESTS ENHANCED UPLIFT FOR CLOUDS THIS AFTERNOON. THIS WILL ALLOW AREAS OVER OUR GA ZONES TO REMAIN SLIGHTLY COOLER THAN NORMAL. THEREFORE HAVE LOWERED HIGH TEMPS A FEW DEGREES AS SOLAR HEATING SHOULD BE LIMITED IN THE AFTERNOON. HIGHS FOR TODAY SHOULD MAX OUT IN THE UPPER 80S WITH A FEW LOCATIONS REACHING 90...EXCEPT ALONG THE COAST WHERE UPPER MID 80S WILL BE SEEN. LATEST RUC SHOWS AN INCREASINGLY ONSHORE FLOW TO RETURN OVER OUR CWA LATER THIS MORNING AS HIGH PRESSURE BEGINS TO SHIFT EAST. WE SHOULD SEE A SHIFT IN WIND DIRECTION FROM EAST NORTHEAST TO SOUTHEAST DURING THE AFTERNOON. GUIDANCE ALSO FAVORS AN INCREASE IN MOISTURE TODAY. GIVEN TROUGH EXPECTED TO BE IN PLACE...DECIDED TO RAISE DEWPTS INLAND DUE TO AN INCREASE IN ONSHORE FLOW AND LIMITED MIXING OUT OF MOISTURE IN THE AFTERNOON DUE TO INCREASED CLOUD COVER NOT ALLOWING ENHANCED THERMAL MIXING. LIGHT SHOWER ACTIVITY REMAINS OVER THE JACKSONVILLE AREA. WITH TIME...SOME LIGHT SHOWERS WITH AN ISOLATED THUNDERSTORM OR TWO MAY PUSH NORTHEAST INTO OUR SOUTHERN ZONES...MAINLY SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA. HAVE INCREASED SOME LOCATIONS TO 30 POPS IN EXTREME SOUTHEASTERN GEORGIA AND COASTAL WATERS WHERE ENHANCED ACTIVITY IS PROBABLE. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... SKIES WILL BE PARTLY CLOUDY THROUGH TONIGHT AS CIRRUS ASSOCIATED WITH THE UPPER LEVEL JET CONTINUES TO STREAM ACROSS THE AREA FROM THE SOUTHWEST. LOW TEMPERATURES TONIGHT WILL STILL BE BELOW NORMAL...BUT WILL ALSO SLOWLY MODIFY FROM PREVIOUS NIGHTS DUE TO THE WEAK ONSHORE FLOW AND INCREASING MOISTURE AT THE SURFACE. HOWEVER...HAVE LEANED TOWARD THE LOWER END OF GUIDANCE AS ONLY THE HIGH LEVEL CLOUDS WILL PREVENT GOOD RADIATIONAL CONDITIONS FROM OCCURRING. MOISTURE WILL CONTINUE TO INCREASE ACROSS THE AREA ON WEDNESDAY AS A WEAK SURFACE TROUGH LIFTS NORTH. THE INCREASE IN MOISTURE...THE NEARBY BOUNDARY AND A WEAK SHORT WAVE ROTATING AROUND THE BASE OF THE UPPER LEVEL LOW MAY BE ENOUGH TO SPARK SCATTERED AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS ACROSS THE AREA. THE STORM PREDICTION CENTER HAS PLACED SOUTHEAST GEORGIA IN A 5 PERCENT RISK ON WEDNESDAY...AS THIS AREA WILL EXPERIENCE MODERATE INSTABILITY WITH DEWPOINTS NEARING 70...CAPE VALUES APPROACHING 1500 J/KG AND LI/S LOWERING TO NEAR -5. CONTINUED SLOW MODIFICATION OF TEMPERATURES IS EXPECTED DURING THIS PERIOD AS WELL. && .LONG TERM /THURSDAY THROUGH MONDAY/... ATLANTIC HIGH PRESSURE TRIES TO RE-ESTABLISH ITSELF OVER THE AREA THU INTO FRI. HOWEVER...PERSISTENT UPPER TROUGHING TO OUR N AS WELL AS A DEVELOPING PIEDMONT TROUGH INLAND WILL MAKE FOR A SLIGHTLY WETTER THAN NORMAL PATTERN THROUGH THE WEEKEND. THUS...WILL MAINTAIN 30/40 POPS FOR MUCH OF THE PERIOD...MAINLY FOR AFTERNOON/EARLY EVENING SHOWERS AND THUNDERSTORMS. TEMPERATURES WILL RUN WITHIN A COUPLE DEGREES EITHER SIDE OF CLIMO THROUGH THE PERIOD. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... VFR CONDITIONS WILL PREVAIL THROUGH 12Z WED. OTHER THAN CIRRUS CONTINUING TO STREAM ACROSS THE AREA THROUGH MUCH OF THE FORECAST PERIOD DUE TO AN UNSEASONABLY STRONG UPPER LEVEL JET...EXPECT FEW TO SCATTERED CUMULUS TO DEVELOP LATE THIS MORNING INTO THIS AFTERNOON WITH THE HEATING OF THE DAY. LIGHT NE/E WINDS THIS MORNING WILL VEER SE THIS AFTERNOON WITH PEAK WIND SPEEDS UP AROUND 10-12 KT. EXTENDED AVIATION OUTLOOK...PREVAILING CIGS/VSBY WILL BE VFR THROUGH THE PERIOD. ISOLD TO SCT SHOWERS AND TSTMS MAY BRIEFLY PRODUCE MVFR OR IFR CONDITIONS EACH AFTN/EVNG WED-SAT. && .MARINE... HIGH PRESSURE WILL MOVE OFF THE COAST NORTH OF THE AREA TODAY...AS A WEAK TROUGH APPROACHES FROM THE SOUTH. MARINE FORECAST APPEARS TO BE ON TRACK FOR TODAY. LATEST OBS FROM BUOYS 41004 AND 41008 HAVE EAST WINDS AROUND 10 KNOTS AND SEAS 2 TO 3 FEET WITH MOST OF IT BEING ASSOCIATED WITH SWELL FROM THE NORTH NORTHEAST. IN GENERAL...WE WILL SEE A SLIGHT INCREASE IN WAVE HEIGHT LATER TODAY...ESPECIALLY OVER OUR GA COASTAL ZONES WHERE SHOWER AND THUNDERSTORM ACTIVITY WILL LEAD TO 4 FEET SEAS. NO HAZARDS ARE EXPECTED AT THIS TIME. AS HIGH PRESSURE CONTINUES TO MOVE OFF THE COAST NORTH OF THE AREA TODAY...A THIS TROUGH IS EXPECTED TO LIFT NORTH ACROSS THE WATERS WEDNESDAY. OVERALL ONSHORE WINDS WILL PREVAIL...ALTHOUGH THE FLOW SHOULD VEER MORE SOUTHERLY ON WEDNESDAY FOLLOWING THE PASSAGE OF THE TROUGH. WIND SPEEDS COULD REACH UP AROUND 15 KT LATE THIS AFTERNOON INTO THIS EVENING...OTHERWISE WINDS WILL BE LESS THAN 15 KT THROUGH WEDNESDAY NIGHT. SEAS OF 2-3 FT CAN BE EXPECTED...ALTHOUGH MAY BUILD UP TO 4 FT IN THE OUTER GEORGIA WATERS LATER TODAY AS THE ONSHORE FLOW INCREASES. THURSDAY THROUGH SATURDAY...ATLANTIC HIGH PRESSURE WILL RE- ESTABLISH ITSELF OVER THE WATERS THROUGH THE WEEKEND. RATHER TRANQUIL MARINE WEATHER IS EXPECTED THROUGH THE PERIOD...WITH WINDS AND SEAS REMAINING BELOW HEADLINE CRITERIA. && .FIRE WEATHER... MODEL SOUNDINGS SHOW PLENTY OF DRY AIR IN THE LOW AND MID LEVELS OF THE ATMOSPHERE TODAY...AND EXPECT SOME OF THIS TO MIX TO THE SURFACE WITH THE HEATING OF THE DAY. AS A RESULT...MINIMUM RELATIVE HUMIDITY VALUES MAY APPROACH NEAR CRITICAL LEVELS WELL INLAND THIS AFTERNOON. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ DPB ga AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 1050 AM EDT TUE JUL 24 2007 .LATE MORNING UPDATE... CURRENT FORECAST IS IN GOOD SHAPE. HAVE MADE MINOR ADJUSTMENTS TO DEWPOINTS FOR THIS AFTERNOON AND HAVE RAISED TEMPERATURES A DEGREE OR TWO OVER THE EAST. MORNING ACARS SOUNDINGS FROM SDF INDICATE THUNDERSTORM ACTIVITY SHOULD NOT DEVELOP OVER THE WESTERN PORTION OF THE FORECAST AREA SO WE WILL KEEP THE WEST DRY AND CHANCE POPS OVER THE FAR EAST. --MB PREVIOUS DISCUSSION BELOW SHORT TERM (TODAY AND TONIGHT)... FCST CONCERN DURING THE SHORT TERM CENTERS ON TSTM CHANCES THIS AFTERNOON AND EVENING ASSOCIATED WITH UPR LOW...WHICH CURRENTLY IS CENTERED NEAR THE OH-WV STATE BORDER. THIS LOW IS SPINNING HIGH AND SOME MID-LEVEL MOISTURE SWWD INTO OH VALLEY...BUT RADAR SHOWS NO PRECIP ACROSS CNTRL KY AND S-CNTRL IN AT THIS TIME. NAM...GFS...AND RUC MODELS FCST LITTLE OVERALL MOVEMENT OF UPR LOW THRU THIS EVENING. A MESO SFC ANALYSIS AT 06Z SHOWED A SFC TROF ALIGNED SW-NE OVER CNTRL KY. CONVECTION ON MONDAY AFTERNOON OCCURRED MAINLY S OF THIS AXIS ALONG AN APPARENT OUTFLOW BOUNDARY AND IN CONJUNCTION WITH TERRAIN OVER SERN KY AND ERN TN. WITH UPR LOW NOT MOVING ALL THAT MUCH TODAY AND WITH CURRENT WATER VAPOR IMAGERY NOT SHOWING ANY DEFINITIVE SHORTWAVES ROTATING AROUND LOW...FEEL THAT ISOLD TO SCT TSTMS THIS AFTERNOON AND EVENING WILL BE CONFINED TO E-CNTRL AND ERN PART OF S-CNTRL KY...ROUGHLY ALONG AND E OF A FFT TO GLASGOW LINE. THIS AXIS WILL BE ALONG AND S OF WEAK SFC BOUNDARY...AND IT ALSO ALIGNS WITH QPF AND INSTABILITY AXIS FROM GFS AND RUC. ON THE OTHER HAND...NAM APPEARS TO SHOW ITS TYPICAL HIGH BIAS OF SFC DEPWTS AND RESULTING GREATER SFC BASED INSTABILITY...THEREBY ALLOWING SCT CONVECTION TO OCCUR FARTHER W OVER CNTRL KY. AS WAS THE CASE YESTERDAY...BEST TSTM COVERAGE SHOULD AGAIN OCCUR OVER ERN/SERN KY THIS AFTERNOON. ANY TSTM ACTIVITY SHOULD DISSIPATE TONIGHT OVER ERN PARTS OF CNTRL KY. CONTINUED MID/HIGH LEVEL MOISTURE WILL KEEP SKY PARTLY CLOUDY. MOS GUIDANCE TEMPS TODAY AND TONIGHT ARE WITHIN A FEW DEGREES OF EACH OTHER AND SEEM REASONABLE. TWF .LONG TERM (WEDNESDAY THRU MONDAY)... MEANDERING UPR LOW ACRS THE ERN OH VLY AT THE START OF THIS PERIOD FCST BY BOTH NAM/GFS TO WOBBLE NWWD TO THE LOWER GREAT LAKES THU WHILE FILLING. AFTERWARD...LOW OPENS TO A TROF FROM THE GREAT LAKES INTO THE OH VLY (NAM) OR TRANSITIONS ENE WITH TROF FARTHER EAST ACRS THE ERN OH VLY FRI (GFS). THE GFS SOLUTION IS IN BETTER AGREEMENT WITH THE NEW RUNS OF THE ECMWF AND ENSEMBLE MEANS AND WILL BE FOLLOWED FOR THE THU/FRI PERIOD. BOTH MODELS SHOW WEAK SFC/LO LEVEL SLY FLO/CONTD MSTR TRANSPORT INTO OUR FA WED...HOWEVER...LITTLE IN THE WAY OF FORCING...OTHER THAN POSITIONING OF UPR LO/STEEPER LAPSE RATES...AS WEAK SFC TROF BECOMES DIFFUSE. OUR CURRENT FCST OF 20 POPS WRN FA AND 40 ERN AREAS LOOK O.K. BASED ON DEEPER MOISTURE PROGGED EAST BY THE MODELS...WILL HOLD OFF TIL AFTN PER STEEPENING LAPSE RATES. WILL CONTINUE A DIURNAL DOWNWARD TREND WED NIGHT...KEEPING POPS ONLY THRU THE EVENING. FROM THU ON...WILL GENERALLY FOLLOW GFS/ENSEMBLE MEANS/ECMWF WITH A NLY COMPONENT OF UPR LOW MOVEMENT RESULTING IN A DECREASING POP TREND FOR ALL EXCEPT OUR NRN/NERN FA...CLOSEST TO PROGGED UPR LO POSITION. THIS CONSISTENT WITH HPCS PLACEMENT OF HIER QPF FOR THU AND ENSEMBLE MEANS/ECMWF PLACEMENT OF DEEPEST MOISTURE FRI. SCT TSTMS TO REMAIN IN THE FCST FOR THE WEEKEND AS A CDFNT REACHES THE UPR OH VLY SAT AND OUR FA EARLY SUN...EXITING OUR SRN FA SUN NGT. WILL KEEP TEMPS PRETTY MUCH WHERE THEY ARE NOW FOR THIS LONG RANGE PD AFTER EXAMINING MEX MOS. DK && .AVIATION (12Z TAFS)... UPPER LOW NEAR OH-WV BORDER CONTINUES TO SPIN MOISTURE AROUND SRN AND WRN SIDE OF LOW. OVER CNTRL KY...THIS MOISTURE IS MID AND HIGH LEVEL...ALTHOUGH SCT ELEVATED CONVECTION HAS DEVELOPED OVER ERN KY EARLY THIS MORNING A LITTLE CLOSER TO THE UPPER LOW AND PERHAPS INFLUENCED BY TERRAIN AND A PERSISTENT WEAK SFC TROF ACRS CNTRL/ERN KY. THE TSTMS ARE MOVING EWD AT THIS TIME AWAY FROM CNTRL KY. FOR TODAY...PROXIMITY OF UPPER LOW AND SOME SFC HEATING SHOULD ALLOW ENOUGH DESTABILIZATION FOR ISOLD TO SCT TSTMS THIS AFTERNOON OVER PARTS OF E-CNTRL KY POSSIBLY INCLUDING LEX DURING THE LATE AFTERNOON. SDF AND BWG SITES SHOLD REMAIN DRY WITH VFR CONDITIONS. BY EARLY WEDNESDAY MORNING...HIGHER SFC DEWPTS MAY LEAD TO LIGHT FOG AT LEX AND/OR BWG. TWF .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 700 AM EDT TUE JUL 24 2007 .AVIATION (12Z TAFS)... UPPER LOW NEAR OH-WV BORDER CONTINUES TO SPIN MOISTURE AROUND SRN AND WRN SIDE OF LOW. OVER CNTRL KY...THIS MOISTURE IS MID AND HIGH LEVEL...ALTHOUGH SCT ELEVATED CONVECTION HAS DEVELOPED OVER ERN KY EARLY THIS MORNING A LITTLE CLOSER TO THE UPPER LOW AND PERHAPS INFLUENCED BY TERRAIN AND A PERSISTENT WEAK SFC TROF ACRS CNTRL/ERN KY. THE TSTMS ARE MOVING EWD AT THIS TIME AWAY FROM CNTRL KY. FOR TODAY...PROXIMITY OF UPPER LOW AND SOME SFC HEATING SHOULD ALLOW ENOUGH DESTABILIZATION FOR ISOLD TO SCT TSTMS THIS AFTERNOON OVER PARTS OF E-CNTRL KY POSSIBLY INCLUDING LEX DURING THE LATE AFTERNOON. SDF AND BWG SITES SHOLD REMAIN DRY WITH VFR CONDITIONS. BY EARLY WEDNESDAY MORNING...HIGHER SFC DEWPTS MAY LEAD TO LIGHT FOG AT LEX AND/OR BWG. TWF .SHORT TERM (TODAY AND TONIGHT)... FCST CONCERN DURING THE SHORT TERM CENTERS ON TSTM CHANCES THIS AFTERNOON AND EVENING ASSOCIATED WITH UPR LOW...WHICH CURRENTLY IS CENTERED NEAR THE OH-WV STATE BORDER. THIS LOW IS SPINNING HIGH AND SOME MID-LEVEL MOISTURE SWWD INTO OH VALLEY...BUT RADAR SHOWS NO PRECIP ACROSS CNTRL KY AND S-CNTRL IN AT THIS TIME. NAM...GFS...AND RUC MODELS FCST LITTLE OVERALL MOVEMENT OF UPR LOW THRU THIS EVENING. A MESO SFC ANALYSIS AT 06Z SHOWED A SFC TROF ALIGNED SW-NE OVER CNTRL KY. CONVECTION ON MONDAY AFTERNOON OCCURRED MAINLY S OF THIS AXIS ALONG AN APPARENT OUTFLOW BOUNDARY AND IN CONJUNCTION WITH TERRAIN OVER SERN KY AND ERN TN. WITH UPR LOW NOT MOVING ALL THAT MUCH TODAY AND WITH CURRENT WATER VAPOR IMAGERY NOT SHOWING ANY DEFINITIVE SHORTWAVES ROTATING AROUND LOW...FEEL THAT ISOLD TO SCT TSTMS THIS AFTERNOON AND EVENING WILL BE CONFINED TO E-CNTRL AND ERN PART OF S-CNTRL KY...ROUGHLY ALONG AND E OF A FFT TO GLASGOW LINE. THIS AXIS WILL BE ALONG AND S OF WEAK SFC BOUNDARY...AND IT ALSO ALIGNS WITH QPF AND INSTABILITY AXIS FROM GFS AND RUC. ON THE OTHER HAND...NAM APPEARS TO SHOW ITS TYPICAL HIGH BIAS OF SFC DEPWTS AND RESULTING GREATER SFC BASED INSTABILITY...THEREBY ALLOWING SCT CONVECTION TO OCCUR FARTHER W OVER CNTRL KY. AS WAS THE CASE YESTERDAY...BEST TSTM COVERAGE SHOULD AGAIN OCCUR OVER ERN/SERN KY THIS AFTERNOON. ANY TSTM ACTIVITY SHOULD DISSIPATE TONIGHT OVER ERN PARTS OF CNTRL KY. CONTINUED MID/HIGH LEVEL MOISTURE WILL KEEP SKY PARTLY CLOUDY. MOS GUIDANCE TEMPS TODAY AND TONIGHT ARE WITHIN A FEW DEGREES OF EACH OTHER AND SEEM REASONABLE. TWF .LONG TERM (WEDNESDAY THRU MONDAY)... MEANDERING UPR LOW ACRS THE ERN OH VLY AT THE START OF THIS PERIOD FCST BY BOTH NAM/GFS TO WOBBLE NWWD TO THE LOWER GREAT LAKES THU WHILE FILLING. AFTERWARD...LOW OPENS TO A TROF FROM THE GREAT LAKES INTO THE OH VLY (NAM) OR TRANSITIONS ENE WITH TROF FARTHER EAST ACRS THE ERN OH VLY FRI (GFS). THE GFS SOLUTION IS IN BETTER AGREEMENT WITH THE NEW RUNS OF THE ECMWF AND ENSEMBLE MEANS AND WILL BE FOLLOWED FOR THE THU/FRI PERIOD. BOTH MODELS SHOW WEAK SFC/LO LEVEL SLY FLO/CONTD MSTR TRANSPORT INTO OUR FA WED...HOWEVER...LITTLE IN THE WAY OF FORCING...OTHER THAN POSITIONING OF UPR LO/STEEPER LAPSE RATES...AS WEAK SFC TROF BECOMES DIFFUSE. OUR CURRENT FCST OF 20 POPS WRN FA AND 40 ERN AREAS LOOK O.K. BASED ON DEEPER MOISTURE PROGGED EAST BY THE MODELS...WILL HOLD OFF TIL AFTN PER STEEPENING LAPSE RATES. WILL CONTINUE A DIURNAL DOWNWARD TREND WED NIGHT...KEEPING POPS ONLY THRU THE EVENING. FROM THU ON...WILL GENERALLY FOLLOW GFS/ENSEMBLE MEANS/ECMWF WITH A NLY COMPONENT OF UPR LOW MOVEMENT RESULTING IN A DECREASING POP TREND FOR ALL EXCEPT OUR NRN/NERN FA...CLOSEST TO PROGGED UPR LO POSITION. THIS CONSISTENT WITH HPCS PLACEMENT OF HIER QPF FOR THU AND ENSEMBLE MEANS/ECMWF PLACEMENT OF DEEPEST MOISTURE FRI. SCT TSTMS TO REMAIN IN THE FCST FOR THE WEEKEND AS A CDFNT REACHES THE UPR OH VLY SAT AND OUR FA EARLY SUN...EXITING OUR SRN FA SUN NGT. WILL KEEP TEMPS PRETTY MUCH WHERE THEY ARE NOW FOR THIS LONG RANGE PD AFTER EXAMINING MEX MOS. DK && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ ky AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 751 AM EDT TUE JUL 24 2007 UPDATED FOR AVIATION DISCUSSION .DISCUSSION (ISSUED AT 443 AM EDT)... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE HIGH TEMPERATURES THIS AFTERNOON. WATER VAPOR IMAGERY AND RUC SHOWING A CLOSED LOW OVER EASTERN OHIO AND LARGE HIGH CENTERED OVER SOUTH DAKOTA BLANKETING MUCH OF THE NORTHERN PLAINS. A RIDGE EXTENDING EAST FROM THIS HIGH STRETCHES ACROSS LAKE SUPERIOR INTO EAST CENTRAL ONTARIO. WEAK SHORTWAVES TRAVERSING THE RIDGE ARE OVER NORTHERN LOWER MICHIGAN AND OVER THE KFGF AREA. SURFACE ANALYSIS DEPICTS A BROAD HIGH COVERING EAST CENTRAL CONUS...A WEAK LOW OVER WESTERN SOUTH DAKOTA...AND A COLD FRONT OVER CENTRAL CANADA. NUMEROUS SHOWERS AND THUNDERSTORMS WERE OCCURRING OVER THE HIGH PLAINS DUE TO INCREASED MOISTURE AND UPSLOPE CONDITIONS IN THAT AREA. A LARGE RIDGE OFF THE EAST COAST WILL KEEP THE MID LEVEL OHIO LOW AND THE NORTHERN PLAINS RIDGE FROM MOVING VERY MUCH TODAY. FRONTOGENESIS OVER SASKATCHEWAN SUPPORTS THE DEVELOPMENT OF A LOW OVER NORTHEAST MONTANA AND A COLD FRONT OVER SOUTH CENTRAL CANADA. ANTI-CYCLONIC FLOW AROUND THE EASTERN CONUS HIGH WILL CONTINUE TO DRAW WARM MOIST LOW LEVEL AIR INTO THE FORECAST AREA TODAY. GFS SHOWING HIGHER SURFACE-700MB RH WILL BE ALONG THE LAKE MICHIGAN SHORE. LAKE BREEZES SHOULD SET UP THIS AFTERNOON UNDER MOSTLY CLEAR SKIES AND LIGHT WINDS. FORECAST SOUNDINGS SUGGEST MLCAPE VALUES COULD EXCEED 1000 J/KG OVER CENTRAL AND EAST COUNTIES OF CWA. INCREASED RH AND LITTLE MORE INSTABILITY OVER THE SOUTHERN COUNTIES COULD PRODUCE SOME SHOWERS AND THUNDERSTORMS TRIGGERED BY LAKE BREEZE CONVERGENCE...SO WILL KEEP A MEAN OF SLIGHT CHANCE OF SHOWERS OVER THE SOUTHERN COUNTIES. MOSTLY SUNNY SKIES WILL PREVAIL. THE TRAJECTORY FORECAST SUGGESTING DRAWING THE AIR MASS OVER WISCONSIN YESTERDAY INTO THE FORECAST AREA. LOOKING FOR TEMPERATURES IN THE MID 80S ACROSS THE REGION THIS AFTERNOON. WINDS WILL BE LIGHT SO CONDITIONS ARE FAVORABLE FOR LAKE BREEZES SO TEMPERATURES NEAR THE LAKE SHOULD REMAIN ONLY IN THE MID 70S. THE MID LEVEL LOW OVER OHIO WILL STILL SHOW LITTLE MOVEMENT THROUGH TONIGHT AS WILL THE RIDGE OVER THE LAKE SUPERIOR. A WEAK SHORTWAVE TRAVERSING THE RIDGE WILL SLIDE THROUGH THE FORECAST AREA. THE SURFACE LOW OVER MONTANA WILL LIFT INTO SOUTHERN MANITOBA DRAGGING A COLD FRONT WITH IT. SOUTHWEST FLOW OVER CENTRAL PLAINS WILL CONTINUE TO BRING PLENTY OF WARM MOIST AIR INTO THE AREA. OVERNIGHT LOWS SHOULD BE JUST A LITTLE WARMER THAN THIS MORNINGS. THE MID LEVEL LOW WILL LIFT INTO THE LOWER GREAT LAKES ON THURSDAY AND REMAIN OVER THAT AREA THROUGH FRIDAY. THE RIDGE OVER THE NORTHERN PLAINS WILL BUILD. WEAK SHORTWAVE MIGRATING BETWEEN THESE TWO SYSTEM WILL PASS THROUGH THE AREA. SURFACE LOW AND ASSOCIATED COLD FRONT WILL SHIFT INTO NORTHERN MINNESOTA BY THURSDAY MORNING AND THROUGH THE FORECAST AREA THURSDAY NIGHT. SHORTWAVE ENERGY AND ISENTROPIC ASCENT ASSOCIATED WITH THE FRONTAL SYSTEM WILL GENERATE A CHANCE OF SHOWERS AND THUNDERSTORMS OVER THE AREA STARTING THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. DRY AIR SHOULD RETURN TO THE AREA BEHIND THE FRONTAL SYSTEM. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... VIS/CIG TOOK A NOSEDIVE TO LIFR AT KCMX IN THE LAST HR OR SO. GIVEN SHALLOW NATURE OF THIS RADIATION FOG...IT SHOULD LIFT QUICKLY IN THE NEXT HR OR SO AS JULY SUN WARMS THE BOUNDARY LAYER. OCCASSIONAL MVFR CIGS ARE SHOWING UP AT KSAW. BELIEVE THIS WILL BE SHORT LIVED GIVEN VFR CLOUDS DOMINATING THE AREAS OUTSIDE OF WHERE FOG IS OCCURRING. SO...AFTER THE NEXT OR TWO...ANTICIPATE VFR CONDITIONS TO RULE THE DAY INTO THE EARLY EVENING AT KSAW/KCMX. CONDITIONS TONIGHT AGAIN LOOK FAVORABLE FOR FOG DEVELOPMENT WITH MOIST LOW-LEVELS TRAPPED BLO DRIER/WARMER LAYER ALOFT. OPTED TO DROP VIS AT KCMX/KSAW TO MVFR AT 04Z WITH IFR VIS LATER IN THE NIGHT. NOT COMPLETELY OUT OF THE QUESTION THAT LIFR CONDITIONS COULD DEVELOP LATE. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... ONCE AGAIN...FOG IS A FCST CHALLENGE FOR THE EARLY MORNING FCST. SHIP JUST OFF COPPER HARBOR INDICATED VIS OF 2 1/2NM AT 03Z. OTHERWISE...THERE HAVE BEEN NO INDICATIONS OF FOG FROM THE FEW SHIP OBS SINCE THEN. UPON VERY CLOSE EXAMINATION OF SATELLITE IMAGERY... THERE ARE HINTS THAT FOG MAY BE PRESENT OVER THE NORTHERN PART OF THE LAKE...GENERALLY ALONG A LINE FROM JUST N OF THE KEWEENAW TO THE EASTERN LAKE BUOY. HAVE THUS OPTED TO MENTION PATCHY FOG FOR TODAY. AFTER SUNRISE...VIS SATELLITE IMAGERY WILL REVEAL WHETHER FOG IS PRESENT ANYWHERE OVER THE LAKE. OTHERWISE...WINDS UNDER 20KT SHOULD PREVAIL THRU THE FCST PERIOD. HIGHEST WINDS WILL OCCUR IN ASSOCIATION WITH A TROF CROSSING LAKE SUPERIOR THU NIGHT/FRI MORNING. SE TO S WINDS AHEAD OF TROF MAY INCREASE TO AROUND 20KT OVER ERN LAKE SUPERIOR WED NIGHT/THU. AFTER TROF PASSAGE...NRLY WINDS MAY REACH 20KT FOR A TIME OVER MUCH OF THE LAKE. .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DISCUSSION...DLG MARINE/AVIATION...ROLFSON mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE DULUTH MN 1046 AM CDT TUE JUL 24 2007 .UPDATE... TOOK FOG OUT FOR THIS MORNING...ELIMINATED PRECIPITATION TODAY AND CHANGED THE FORECAST TO AREAS OF FOG LATE TONIGHT AND EARLY WEDNESDAY. && .DISCUSSION... A CAP...DEFIINED CRUDELY AS ABOVE 10C AT 700 MB FOR THE PURPOSES OF AN AREAL PERSPECTIVE...COVERS OUR ENTIRE FORECAST AREA. CONVECTION FEEDING ON LOCALLY GREATER MOISTURE AND AN EARLIER BROKEN CAP JUST NORTH OF THE BOUNDARY WATERS AREA SEEMS TO BE HAVING TO DO TOO MUCH WORK AGAINST THE GROWING CAP SO...IN SPITE OF STRONG SUNSHINE...SEEMS TO BY DYING. PRIND LIGHT RAIN FROM DYING CONVECTION TO OUR WEST WILL NOT REACH OUR FORECAST AREA. THAT CONVECTION SEEMS TO BE HOLDING TOGETHER...SEVERAL COUNTIES WEST OF OUR AREA OVER THE UPPER RED RIVER. SO...WE HAVE KEPT THINGS DRY THROUGH THE AFTERNOON AND EVENING. TRAPPED BY THE CAP IS SURFACE TEMPERATURES THAT WILL APPROACH OR REACH 35C INLAND AND DEW POINTS AS HIGH AS THE 22C TO 24C RANGE. THAT CAP IS PROTECTING US FROM REAL CONVECTIVE TROUBLE...THERE IS PLENTY OF ENERGY THERE. WITH INVERSIONS IN PLACE AND MOISTURE FLUX DOWNWARD...WE ANCPT PLENTY OF RADIATION FOG TONIGHT. WITH THE LAKE RELATIVELY COOL AND EVEN MORE INVERSIONS OVER THE WATER...WE ALSO ANCPT SIGNIFICANT DENSE MARINE FOG TO PERSIST. && .AVIATION... WDSPRD LIFR IN GNDFG WL DVLP AGN TNGT AND PRST INTO WED MRNG. OTRW...VFR CONDS WL PVL. && .PREV DISCUSSION... /ISSUED 310 AM CDT TUE JUL 24 2007/ DISCUSSION...MCS IN NE ND ATTM AND ITS IMPACT ON THE NW QUAD OF THE FA THE CONCERN FOR THE SHORT TERM. 00Z MODELS ARE TOO FAR E WITH THE SHORT WAVE THAT IS MOVING THROUGH MOVING ALONG THE INTERNATIONAL BORDER. 06Z RUC ALSO OVERDOING IT...BUT HAS THE MCS WEAKENING BEFORE REACHING THE FA WITH NO PCPN. DID HOWEVER ADD A SMALL POP THIS MORNING FOR THE POSSIBILITY IT MAY MAKE IT THAT FAR E. OVER THE REST OF THE FA...SFC RIDGING COVERS THE AREA. LOWS CLOUDS AND FOG ARE DEVELOPING/SPREADING OVER THE FA. FOG ALSO A FACTOR OVER THE SOUTHERN HALF OF MN FA WITH MZH ALREADY AT 1/2 MILE. WILL MONITOR CLOSELY FOR DENSE FOG POTENTIAL EARLY. THE ND SHORT WAVE IS PROGGED TO DROP SEWD AND INTO THE FA TODAY. HOWEVER...MODELS ARE NOT GENERATING ANY QPF. WILL KEEP GRIDS RAIN FREE THIS AFTERNOON...BUT LOW CONFIDENCE. HOT AND HUMID CONDITIONS TODAY...APPARENT TEMPERATURE APPROACHES HEAT ADVISORY CRITERIA OVER CROW WING...SOUTHERN CASS AND AITKIN COUNTIES THIS AFTERNOON. NO HEADLINES ATTM...BUT WILL MENTION TO NEXT SHIFT. LITTLE CHANGE IN THE ATMOSPHERE OVER THE FA TONIGHT AND EXPECT PATCHY FOG TO DEVELOP AFTER MIDNIGHT AGAIN. UPPER LEVEL LOW THAT HAS BEEN AFFECTING THE E COAST WILL RETROGRADE INTO THE LOWER GREAT LAKES WEDNESDAY. MEANWHILE...A COLD FRONT WILL APPROACH FROM THE W AIDED BY AN UPPER LEVEL SHORT WAVE. MODELS DIFFER ON WHETHER THUNDERSTORMS WILL BREAK OUT IN NW WI IN THE AFTERNOON. WILL KEEP WITH PERSISTENCE AND NOT MENTION RAIN FOR NOW. APPROACHING SYSTEMS BEGIN TO CONVERGE ON THE FA WEDNESDAY NIGHT WITH THUNDERSTORMS DEVELOPING. TIMING AN ISSUE AT THIS POINT AND HAVE LEFT GRIDS AS IS. BETTER CHANCES FOR RAIN THURSDAY AND FRIDAY AS THE COLD FRONT PUSHES THROUGH. COOLER AND DRIER CONDITIONS EXPECTED FRIDAY NIGHT INTO MONDAY. AVIATION...ABUNDANT LOW LEVEL MOISTURE WILL CONTINUE TO RESULT IN AREAS OF MVFR/IFR CONDITIONS WITH FOG THROUGH EARLY MORNING. CONDITIONS SHOULD IMPROVE TO VFR ACROSS MUCH OF THE NORTHLAND BY MID MORNING WITH SCT-BKN MID LEVEL CU. HOWEVER...MVFR CIGS MAY PERSIST ACROSS PORTIONS OF NW WI THROUGH MID DAY. AREAS OF FOG LOOK TO REDEVELOP ACROSS THE ENTIRE FORECAST AREA LATE TONIGHT. && POINT TEMPS/POPS... DLH 85 65 86 63 / 10 10 10 20 INL 93 68 95 66 / 10 10 10 30 BRD 94 69 95 70 / 10 10 10 20 HYR 93 65 93 66 / 10 10 10 10 ASX 83 64 86 64 / 10 10 10 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. $$ EOM/TL mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 624 AM CDT TUE JUL 24 2007 .UPDATE FOR 12Z AVIATION DISCUSSION. && .PREV DISCUSSION... /ISSUED 340 AM CDT TUE JUL 24 2007/ DISCUSSION... EXTENSIVE CLOUDINESS BLANKETS WEST CENTRAL WI AND PORTIONS OF EAST CENTRAL AND SOUTH CENTRAL MN EARLY THIS MORNING. THE CLOUDINESS HAS ACTUALLY INCREASED IN COVERAGE OVER THE PAST FEW HOURS. 310K THETA SURFACE SHOWING UPGLIDE FROM THE NORTH ACROSS NORTHERN AND WEST CENTRAL WI WITH SOME ADIABATIC OMEGA. MODEL GUIDANCE INDICATING RATHER EXTENSIVE LAYER MOISTURE BELOW 700 MB THROUGH THE DAY. HAVE CUT BACK ON HIGHS OVER WEST CENTRAL WI...THE MSP METRO AREA AND SOUTHWARD ALONG I-35. IF THE CLOUDS STAY...CURRENT HIGH TEMPERATURE FORECAST WILL BE TOO HIGH...IF THE CLOUDS GO... FORECAST WILL BE TOO LOW. TO OUR NORTHWEST...CONVECTIVE COMPLEX CONTINUES TO GROW OVER NE ND. SOME ACTIVITY STARTING TO GET SOUTH OF KFGF ATTM. 850-300MB THICKNESS WOULD HEAD THE ACTIVITY TOWARD OUR NW CWA. 21Z SREF HAD A GOOD HANDLE ON THIS FEATURE. 03Z SREF MAINTAINS THE COMPLEX AND PUSHES IT TOWARD KDLH BY 21Z. THE THUNDERSTORMS ARE ALONG AND NORTH OF ABOUT +13 DEG C AT 700MB. THE RUC TRIES TO MAINTAIN +14 OVER WEST CENTRAL THROUGH CENTRAL MN THROUGH MIDDAY. PLANNING ON GOING DRY ATTM...BUT WILL HAVE TO KEEP AN EYE ON THIS FEATURE EARLY THIS MORNING. HIGHS TODAY FOR WESTERN MN LOOK TO AROUND 93 TO 95 DEGREES IF THIS COMPLEX STAYS AWAY. RAISED DEW POINTS ABOUT 2 DEGREES IN THE GRIDS FOR THE NEXT SEVERAL DAYS ALL AREAS. RESULTING HEAT INDEX VALUES IN THE 100-104 RANGE FOR WEST CENTRAL TODAY AND IN THE 104-107 RANGE ON WEDNESDAY. LITTLE CHANGE TO THE HIGHS FOR WEDNESDAY AND THURSDAY. ONE CHANGE IN THE FORECAST WAS WITH THE PRECIP FORECAST THURSDAY AND THURSDAY NIGHT. DIVIDED THE FORECAST INTO 6 HOUR WINDOWS AND INCREASE POPS INTO THE HIGH CHANCE CATEGORY...MAINLY OVER THE EASTERN AND SOUTHERN CWA. PRETTY GOOD AGREEMENT BETWEEN THE NAM/GFS AND 03Z SREF THAT A FROPA WILL OCCUR BY DAYBREAK FRIDAY. ONE TROUBLING FEATURE SEEN FOR LATE THURSDAY IS THAT PRECIPITABLE WATER VALUES INCREASE TO NEARLY 2.25 INCHES FOR MUCH OF OUR CWA ON BOTH THE NAM AND GFS WITH A 6 HOURLY INCREASE OF OVER HALF AN INCH. WHEN IT FINALLY RAINS...ITS GOING TO POUR. HIGH PRESSURE AND LOWER AFTERNOON HUMIDITY SPREADING IN FOR THE UPCOMING WEEKEND. && .AVIATION.../12Z TAF CYCLE/ IFR(LIFR) STRATUS/FOG ACROSS NORTHWEST AREA EARLY SHOULD GRADUALLY LIFT/DISSIPATE AS MCS MOVES ACROSS EASTERN NORTH/SOUTH DAKOTA THIS MORNING. BEST FORCING FOR THUNDER INTO THE EASTERN DAKOTAS. MVFR CIG/FOG OVER EASTERN MN WILL GRADUALLY LIFT DURING THE DAY AGAIN...WITH RATHER WEAK SOUTHERLY SURFACE FLOW TO CONTINUE. CU RULES SHOW IT SHOULD REMAIN BKN MUCH OF THE DAY HOWEVER. EXPECT SOME CLEARING INTO THE EVENING...AND MORE FOG DEVELOPING LATER WITH LIGHT WINDS AND HIGH DEWPOINTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ DWE/RAH mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 1020 AM EDT TUE JUL 24 2007 .SYNOPSIS... DRY AIR IN THE WAKE OF YESTERDAY`S STORM WILL BRING PARTLY SUNNY WEATHER TO MOST OF THE AREA THIS AFTERNOON. SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE WEDNESDAY THROUGH THE END OF THE WEEK... AS AN UPPER LEVEL LOW PRESSURE AREA MOVES SLOWLY EAST FROM THE OHIO VALLEY TOWARD THE EAST COAST. && .NEAR TERM /UNTIL 5 PM THIS AFTERNOON/... LOW CLOUDS ARE GRADUALLY LIFTING NORTH AROUND THE EAST SIDE OF THE UPPER LOW THIS MORNING... WITH SOME CLEARING HAVING ALREADY OCCURRED ACROSS THE CENTRAL SOUTHERN TIER OF NY AND NORTHEAST PA. EXPECT THE CLEARING TREND TO CONTINUE TO PUSH NORTH... WITH PARTLY SUNNY SKIES ALL AREAS BY LATE AFTERNOON. LATEST RUC SOUNDINGS SHOW CAPPING THIS AFTERNOON... WITH A HINT THAT THE CAP COULD ERODE ENOUGH FOR ISOLATED SHOWERS ACROSS THE WEST CLOSEST TO THE UPPER LOW BY LATE AFTERNOON. BASED ON THIS WILL GO WITH A 20 POP FOR THE CENTRAL SOUTHERN TIER OF NY LATE THIS AFTERNOON... AND A DRY FORECAST ELSEWHERE. && .SHORT TERM /5 PM THIS AFTERNOON THROUGH THURSDAY/... MINOR TWEEKS TO LATTER PDS. CHC FOR MAINLY AFTN CONVECTION NXT FEW DAYS...BETTER CHCS XPCTD ON THU AS INSTABILITY LOOKS A LITTLE BETTER. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... UNCERTAINTY WITH CUTOFF UPPER LEVEL LOW CONTINUES. MODELS NOT AGREEING WITH STACKED LOW OVER OHIO VALLEY. AT START MOST MODELS SHOWING THE UL STACKED LOW GETTING CAPTURED BY A TRANSITORY UL TROF. THIS SENDS A COLD FRONT THROUGH THE AREA SATURDAY. HIGH PRESSURE WILL BUILD IN MONDAY WITH DRY WEATHER AND MODERATING TEMPERATURES. HAVE FOLLOWED HPC GUIDANCE. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... AVP AND ELM ON EDGE OF CLOUDS AND ALREADY MVFR CIGS AND VFR VSBYS. SRN EDGE OF THE LOW CLDS WILL WORK NWD WITH VFR CONDITIONS FINALLY REACHING RME/SYR BY MID/LATE AFTN. W TO SW WINDS AT 5 TO 10 KTS TODAY BECOMING LIGHT TO CALM AGAIN TONIGHT. AN UPPER LOW WILL STALL OVER THE OH VALLEY WITH UNSETTLED WX THRU FRIDAY. AREAS OF LOWER CLOUDS AND SHRA/TSRA MAINLY DURING THE DAYTIME HRS WILL RESULT IN MVFR/IFR CONDS THRU THE PERIOD. MORE SHOWERS AND THUNDERSTORMS SATURDAY WILL AGAIN REDUCE CONDITIONS TO MVFR/IFR AT TIMES. MORNING MVFR FOG POSSIBLE TOO. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...MSE NEAR TERM...MSE SHORT TERM...RHB LONG TERM...TAC AVIATION...TAC ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 1052 AM EDT TUE JUL 24 2007 .SYNOPSIS... AN UPPER LEVEL LOW PRESSURE CENTERED OVER THE EASTERN OH VALLEY WILL SHIFT SLOWLY NW THROUGH WEDNESDAY. CONSIDERABLE CLOUDINESS AND A CHANCE OF SHOWERS AND THUNDERSTORMS WILL CONTINUE ACROSS THE PIEDMONT AND ESPECIALLY THE NORTHWEST PIEDMONT THROUGH WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 12Z SFC ANALYSIS SHOWS A WEAK PRESSURE FIELD OVER THE REGION WITH A TROUGH STRETCHING ACROSS VA WEST INTO WV AND KY. ANOTHER WEAK TROUGH IS LOCATED JUST EAST OF THE HIGHER TERRAIN IN NC AND SC. DEWPOINTS ACROSS THE STATE WERE GENERALLY IN THE UPPER 50S TO LOWER 60S WITH DEWPOINTS IN THE MID 60S IN THE IMMEDIATE COASTAL REGION. 12Z UPPER AIR ANALYSIS SHOWS THE UPPER LOW CENTERED NEAR KPIT HAS MOVED SLOWLY NW DURING THE PAST 24 HOURS. SCT SHOWERS AND A FEW THUNDERSTORMS MOVED ACROSS THE FOOTHILLS AND TRIAD EARLY THIS MORNING. THIS ACTIVITY IN RESPONSE TO A SHORTWAVE ROTATING AROUND THE UPPER LOW. WV SAT IMAGERY SHOWS NEXT DISTURBANCE LOCATED OVER S KY. NAM12 AND RUC DEVELOP AN AREA OF SHOWERS AND THUNDERSTORMS WITH THIS SYSTEM ACROSS THE MOUNTAINS AND THEN MOVE IT EAST DURING THE AFTERNOON. BEST SUPPORT FOR PRECIPITATION IS LOCATED ACROSS THE TRIAD WITH LESSER CHANCES SOUTH AND EAST. SPC HAS HIGHLIGHTED W NC IN THE SEE TEXT OF THE DAY 1 SVR WX OUTLOOK. TEMPERATURES ARE IN FAIRLY GOOD. ADJUSTED TEMPS UP SLIGHTLY WITH THIS UPDATE WITH HIGHS IN THE MID 80S IN THE NW PIEDMONT WHERE MORE CLOUD COVER IS EXPECTED...TO NEAR 90 IN THE SANDHILLS AND SE COASTAL PLAIN WHERE LESS CLOUD COVER IS EXPECTED. PREVIOUS DAYS HAVE SEEN A DECENT DROP IN DEWPOINTS DURING THE PEAK HEATING HOURS. CURRENT UPDATE WILL INCLUDE A DOWNWARD ADJUSTMENT IN DEWPOINTS...ESPECIALLY IN THE EAST TO REFLECT BETTER MIXING. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... BOTH THE GFS/NAM SHOW THE UPPER LEVEL LOW SLOWLY RETROGRADING THROUGH THE OHIO VALLEY TOWARD THE GREAT LAKES THROUGH THURSDAY. DURING THIS PERIOD HIGH/LOW TEMPS ARE EXPECTED TO BE A FEW DEGREES BELOW NORMAL (PRIMARILY NORTHERN HALF OF THE CWA) TO NEAR NORMAL (SOUTHERN HALF OF CWA) ACROSS CENTRAL NC. GFS/NAM BUFR SOUNDINGS SHOW THERMODYNAMIC PROFILES BECOMING MORE FAVORABLE FOR CONVECTION ON WED...AND IF THE GFS BUFR SOUNDINGS ARE TO BELIEVED...VERY FAVORABLE FOR CONVECTION ON THURSDAY. FCST SOUNDINGS ON WED SHOW AROUND 1000 J/KG OR SO OF SFC BASED CAPE ACROSS CENTRAL NC...WITH DEWPOINTS IN THE UPPER 50S TO AROUND 60F. GFS BUFR SOUNDINGS SHOW COPIOUS AMOUNTS OF INSTABILITY ON THURSDAY AFTERNOON...WITH AS MUCH AS 3000-4000 J/KG OF SFC BASED CAPE WITH DEWPOINTS HAVING INCREASED INTO THE LOWER 70S! PWAT VALUES ALSO INCREASE TO NEAR 2.00" ON THURSDAY ACCORDING TO THE GFS. THE GFS SHOWS A BOUNDARY LIFTING NORTH THROUGH THE AREA WED NIGHT AND THU MORNING...WHICH WOULD ALLOW BETTER MOISTURE TO RETURN TO THE AREA...HOWEVER...IT SEEMS LIKE LOWER 70S DEWPOINTS ON THU AFTERNOON WOULD BE A STRETCH AT THIS TIME. A BETTER BET WOULD BE LOWER/MID 60S AT MOST FOR DEWPOINTS BY THU AFTERNOON. THEREFORE...PRECIP CHANCES ARE EXPECTED TO INCREASE ON WED/THU ACROSS THE AREA. SINCE INSTABILITY WILL INCREASE OVER THE AREA ON WED AS MENTIONED ABOVE...AND ENERGY WILL CONTINUE TO ROTATE AROUND THE UPPER LOW INTO CENTRAL NC (BETTER CHANCE OF UPPER LEVEL LIFT IN NW PORTIONS OF THE AREA)... WILL KEEP CHANCE POPS (30-40%) OVER THE ENTIRE AREA...WITH THE HIGHER CHANCES IN THE NW PIEDMONT. SIMILAR POPS FOR THURSDAY...EXCEPT A BIT HIGHER GIVEN BETTER SFC DEWPOINTS (AS MENTIONED ABOVE) AND MORE INSTABILITY...WITH THE BETTER CHANCES AGAIN IN THE NW PIEDMONT. THE REASON FOR NOT GOING ANY HIGHER THAN CHANCE POPS ON THU AFTERNOON IS BECAUSE AT THIS TIME IT APPEARS THE UPPER LEVEL LOW WILL BE MUCH FURTHER NORTH OVER MI / LAKE HURON AND WE WILL BE MORE REMOVED FROM THE FAVORABLE UPPER LEVEL LIFT. HIGH TEMPS ON WED/THU IN THE MID/UPPER 80S (N/NW) TO NEAR 90F (SOUTH) -VINCENT && .LONG TERM /FRIDAY THROUGH MONDAY/... NOT MUCH CHANGE IN GOING FORECAST TRENDS. BROAD TROUGH WILL PERSIST OVER THE EASTERN CONUS DURING THE PERIOD. AT THE SURFACE...A WEAK FRONT WILL MOVE ACROSS THE AREA DURING THE WEEKEND. THUS THERE WILL BE A PERSISTENT CHANCE FOR MAINLY DIURNAL CONVECTION EACH DAY. -RA && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. HOWEVER...CONSIDERABLE AMOUNT OF MID AND HIGH LEVEL CLOUDS WILL MOVE ACROSS THE AREA. THERE IS THE POTENTIAL FOR A FEW SHOWERS AND POSSIBLE A THUNDERSTORM . FOR THIS AFTERNOON BKN CU 4-6KFT AT INT/GSO/RDU TAF SITES ...MOSTLY SCATTERED AT FAY/RWI. BEST CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS WILL BE GSO/INT VICINITIES...ISOLATED RDU AREA. AT THIS TIME LITTLE CHANCE FOR CONVECTION FAY/RWI VICINITIES. THE CHANCE FOR CONVECTION WILL INCREASE FOR ALL TAF SITES MID TO LATE WEEK. ACTIVITY MOST LIKELY DURING THE AFTERNOONS AND EVENINGS. POTENTIAL FOR MVFR/IFR CONDS IN SCATTERED SHOWERS AND TSTMS. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BLAES NEAR TERM...BLAES SHORT TERM...VINCENT LONG TERM...RA AVIATION...JFB nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 1138 AM EDT TUE JUL 24 2007 .SYNOPSIS... AN UNSTABLE AIRMASS ASSOCIATED WITH LOW PRESSURE IN THE UPPER ATMOSPHERE WILL PROVIDE AN INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS THROUGH THURSDAY. TEMPERATURES WILL GRADUALLY INCREASE OVER THE NEXT FEW DAYS AS THE UPPER LOW TRAVELS SLOWLY NORTHWEST. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPR LO CENTERED OVER ERN OH THIS MRNG WITH PREDOMINANTLY MID/HI LVL CLOUDS STREAMING FROM THE NORTH AROUND THE LO AND INTO THE FCST AREA. WDLY SCT -SHRA AND/OR SPRINKLES WERE NOTED JUST NORTH AND EAST OF FCST AREA. TEMPS WERE GENERALLY IN THE L/M70S ATTM. CURRENT SFC ANALYSIS INDCG INV TROF FROM NEAR KZZV BISECTING THE SE FCST AREA AND CONTINUING SW INTO THE KENTUCKY BLUEGRASS REGION. MUCH OF THE HEAVIER CONVECTION ASSOCD WITH POTENT S/WV ROTATING AROUND BASE OF THE UPR LO THIS MRNG HAS BEEN EAST OF FCST AREA IN WEST VIRGINIA. 12Z NAM/RUC HAVE BOTH HANDLED THIS AREA OF TSTMS WELL...AND TAKE THIS CONVECTION NE INTO SW PA INTO AFTN HOURS. EXPECT INV TROF AND LOCALIZED CONV AXIS ALONG IT WILL BE A FOCUS FOR SOME CONVECTIVE DVLPMNT THIS AFTN WITH FILTERED SUNSHINE CONTRIBUTING TO WEAK INSTABILITIES... AND HAVE MAINTAINED 30 POPS OVER SE FCST AREA THRU AFTN HOURS. FURTHER WEST THOUGH...LACK OF INSTABILITY AND NOTED DRY BNDRY LYR OFF OF 12Z KILN SOUNDING SHOULD REALLY HAMPER ANY ORGANIZED PCPN DVLPMNT. HAVE TRIMMED MEASURABLE PCPN AREAS TO I-71 AND POINTS EAST WITH ONLY SPRINKLES EXPECTED FURTHER WEST. KEPT GOOD DEAL OF CLOUDS ACRS FCST AREA FOR AFTN HOURS AND WITH CURRENT TEMPS RUNNING COOLER THAN FCST...HAVE DROPPED AFTN HIGHS BACK A FEW DEG. ZONE AND GRID UPDATES HAVE BEEN SENT. RYAN && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... CHANCE FOR SHOWERS AND THUNDERSTORMS WILL PERSIST IN MARGINALLY UNSTABLE AIRMASS AS THE UPPER LOW MEANDERS THROUGH OHIO. INCREASED POPS TO AROUND 40 PERCENT DURING DAYLIGHT HOURS...THOUGH FORECAST POPS ARE STILL BELOW MOISTER MAV...SINCE THERE WILL PROBABLY BE TOO LITTLE LOW LEVEL FORCING TO RESULT IN NUMEROUS THUNDERSTORMS. ALSO INCREASED SKY COVER SINCE CLOUDS WILL CONTINUE TO ROTATE AROUND THE UPPER LOW. TEMPERATURES ARE LIKELY TO REMAIN BELOW NORMAL WITH THE PRESENCE OF CLOUDS AND SCATTERED PRECIPITATION. STAYED CLOSE TO SLIGHTLY WARMER MAV AS PER PREVIOUS FORECAST. && .LONG TERM /FRIDAY THROUGH MONDAY/... OPERATIONAL MODELS COMING INTO AGREEMENT WITH HAVING THE UPPER LOW MEANDER ACROSS THE UPPER OHIO VALLEY AND GREAT LAKES REGION BEFORE BEING PICKED UP BY THE WESTERLIES AT THE END OF THE WEEK. HAVE OPTED TO SPREAD LOW CHANCE POPS AREAWIDE FOR THURSDAY AND FRIDAY. A SHORT WAVE WILL FOLLOW BEHIND THE UPPER LOW WHICH WILL CAUSE A COLD FRONT TO CROSS THE AREA OVER THE WEEKEND. THERE IS SOME UNCERTAINTY IN TIMING THIS FRONT. FOR NOW HAVE CONCENTRATED HIGHER POPS ON SATURDAY AFTERNOON AND EVENING. BUT KEPT A LINGERING CHANCE IN THE FAR SOUTHERN ZONES INTO SUNDAY. HIGH PRESSURE WILL THEN BUILD IN AT THE END OF THE PERIOD. HIGH TEMPERATURES ARE FORECAST TO BE WITHIN A FEW DEGREES OF NORMAL THROUGH THE LONG TERM BUT LOWS ARE EXPECTED TO BE ABOVE NORMAL. && .AVIATION /16Z TUESDAY THROUGH SATURDAY/... CUTOFF LOW NEAR OH/PA STATE LINE TO DRIFT VERY SLOWLY WEST INTO ERN OHIO TODAY AND WOBBLE AROUND A BIT BEFORE LIFTING N-NW ACROSS NRN OH ON WED. WINDS HAVE BEEN LIGHT OVERNIGHT BUT WITH MID/HIGH LEVEL CIGS ACRS THE TAF SITES FLIGHT CONDITIONS REMAINED VFR ACRS THE TAF SITES. WEAK AXIS OF LO LVL CONVERGENCE TO DEVELOP TO OUR EAST. MARGINAL INSTBY TO DEVELOP ACRS SE WITH CAPES APPROACHING 1000 J/KG THIS AFTN. EXPECT MOST OF THE PRECIP ACTIVITY TO BE ALONG AND EAST OF I-71 WHERE MORE FAVORABLE MSTR...AND INSTBY WL EXIST. HAVE LEFT WESTERN TAFS DRY WITH ONLY A MENTION OF -SHRA WITH NO RESTRICTION TO VSBY AT KILN...KLCK AND KCMH THIS AFTN. OTHERWISE...VFR CONDITIONS EXPECTED. A BETTER CHC OF SHOWERS AND EMBEDDED THUNDER WL EXIST ON WED WITH THE UPPER LOW MIGRATING THRU OHIO. OUTLOOK...SCATTERED THUNDERSTORMS POSSIBLE WEDNESDAY THROUGH SATURDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RENO NV 320 PM PDT TUE JUL 24 2007 .UPDATE #2... AFTER REVIEWING FRESH 18Z GFS/NAM AND 15Z SREF OUTPUT...HAVE DECIDED TO TRIM POPS FOR WED/WED NIGHT IN CA ZONES NORTH OF TAHOE INTO SECTIONS OF WASHOE COUNTY IN WRN NV. MODELS ARE SHOWING MORE ROBUST DRYING/STABILIZING INTO THESE AREAS...THOUGH THERE MAY BE ENOUGH INSTABILITY TO GENERATE AN ISOLD -TSRA OR SHOWER. REST OF FCST UNCHANGED. CS .UPDATE... WILL BE EXPANDING THE FLASH FLOOD WATCH TO COVER ENTIRE CWA WITH AFTERNOON FCST PACKAGE. STORMS DEVELOPING OVER NVZ004 ARE EXHIBITING VERY SLOW STORM MOTION...WITH LOCALLY HEAVY RAINFALL LIKELY. THIS IS CONFIRMED IN THE RUC 0-6KM MEAN WIND FIELDS...WHICH SHOW A RELATIVE MINIMUM (EVEN ZERO) OVER EASTERN SECTIONS OF THE CWA. STORM CURRENTLY EAST OF MIDDLEGATE ON US HIGHWAY 50 HAS LIKELY PRODUCED AT LEAST 0.75" OF RAIN. FURTHER WEST...ESTIMATED STORM MOTIONS NORTH OF TAHOE ALONG SIERRA WILL BE HIGHER PER RUC DATA (10KTS OR SO)...SO THREAT FOR SLOW MOVING CELLS MAY BE MINIMAL THERE. BUT WITH RECENT BURN AREAS (ANGORA/ANTELOPE) ANY APPRECIABLE RAINFALL MAY CAUSE RUNOFF ISSUES. CS && .SHORT TERM... UPPER WAVE OVER CALIF IN CONJUNCTION WITH DESTABILIZATION WILL HELP GENERATE SCT TSRA OVER THE CWA THIS AFTN/EVE. SREF/GFS HIGHLIGHT FAR NRN ZONES ALONG WITH MONO/MINERAL AREAS FOR BEST INSTABILITY...WHICH MAY PAN OUT GIVEN RECENT SATELLITE TRENDS SHOWING BEST CLEARING IN THOSE AREAS. IN FACT...STORMS ARE STARTING TO FIRE OVER TERRAIN IN MONO COUNTY ATTM. SOUNDINGS AND GOES PW PRODUCT SHOWING VALUES NEAR OR ABOVE ONE INCH OVER MOST OF THE CWA (EXCEPT FAR NW)...THEREFORE WITH LIGHT STEERING FLOW THE THREAT FOR HVY RAIN REMAINS. IF CONVECTION CAN DEVELOP OVER NRN ZONES THIS AFTN/EVE...ENHANCED 0-6KM SHEAR MAY HELP ORGANIZE STORMS...OTHERWISE LOOKS LIKE MAINLY PULSE TYPE CELLS ACROSS THE REST OF THE CWA. GFS CONTINUES TO SHOW APPRECIABLE MIDLEVEL MOISTURE TRANSPORT OVERNIGHT AHEAD OF WEAKENING WAVE...THEREFORE WILL CONTINUE CHCS FOR -SHRA OVERNIGHT ACROSS MOST OF THE CWA. WEDNESDAY COULD BE FAIRLY ACTIVE...AS SREF INDICATING PLENTIFUL MOISTURE AND INSTABILITY... ESPECIALLY OVER AREAS EAST OF RENO/CARSON CITY. HAVE INCREASED POPS AS A RESULT...AND GIVEN ANOMALOUSLY HIGH PW VALUES REMAINING IN THE AREA...WILL MENTION LCL HVY RAIN POSSIBLE. WILL NOT ISSUE A SECOND FFA AT THIS TIME...BUT SOMETHING TO RE-EVALUATE DOWN THE ROAD. SIMILAR TO TONIGHT...MOISTURE TRANSPORT SUFFICIENT TO WARRANT CONTINUING POPS FOR -SHRA WED NIGHT ESP IN OUR NV COUNTIES. SWLY FLOW ALOFT PICKS UP A LITTLE ON THURSDAY...ALLOWING FOR DRYING IN THE MIDLEVELS AND INCREASED STABILITY OVER MUCH OF THE WRN CWA. WILL CONTINUE CHC POPS FROM MONO NORTH INTO THE NFL/LOL AREAS...BUT TRIM POPS AS ONE HEADS WESTWARD. SHOULD BE LESS OF A THREAT FOR HVY RAINFALL WITH MOIST PLUME E OF THE AREA. ON FRIDAY...CHCS FOR TS WILL BE CONFINED TO THE FAVORED MONO/MINERAL CONVERGENCE ZONE AREA. SREF SUGGESTS THIS IS LIKELY TO BE THE ONLY AREA WITH SUFFICIENT INSTABILITY TO GENERATE CONVECTION FRI AFTN/EVE. NOT OUT OF THE QUESTION WE COULD SEE SOME VERY ISOLD CELLS DEVELOP OVER PARTS OF CHURCHILL/PERSHING COUNTIES AS WELL WITH AFTN HEATING. SPEAKING OF TEMPS...WE SHOULD EXPECT A WARMING TREND THROUGH THE BALANCE OF THE WEEK...WITH 500MB RIDGE CENTER DRIFTING CLOSER TO THE CWA WITH TIME. CS .LONG TERM...SATURDAY THROUGH TUESDAY... UPPER RIDGE OVER THE FOUR-CORNERS/SOUTHWESTERN US WILL CONTINUE TO DOMINATE THE REGION OVER THE LONG TERM. GFS/ECMWF/UKMET ARE ALL IN GOOD AGREEMENT WITH LONGWAVE PATTERN...INCLUDING AN UPPER LOW MOVING OVER THE PAC NW OVER THE WEEKEND. THIS WILL INCREASE WEST TO SOUTHWESTERLY FLOW ACROSS THE REGION...WHICH WILL DRY US OUT. TEMPERATURES WILL REMAIN IN THE MID TO UPPER 90S ACROSS THE WESTERN NV VALLEYS...WITH MID 80S IN THE EASTERN SIERRA. WITH THE SLIGHT INSTABILITY AND LOCALIZED EFFECTS...EACH AFTERNOON AND EVENING THERE WILL BE A SLIGHT POSSIBILITY FOR AN ISOLATED THUNDERSTORM IN THE MONO-MINERAL COUNTY CONVERGENCE ZONE THROUGH TUESDAY. HOON && .AVIATION... SCTD TSTMS ARE FCST TO DEVELOP OVER MUCH OF THE AREA AFTER 18Z LASTING UNTIL AROUND 04Z. EXPECT LOCALIZED HEAVY RAIN ALONG WITH GUSTY DOWNDRAFT WINDS WITH THESE STORMS. HOON && .REV WATCHES/WARNINGS/ADVISORIES... NV...FLASH FLOOD WATCH CONTINUES FOR NVZ001>005 FROM 21Z/24 TO 05Z/25. CA...FLASH FLOOD WATCH CONTINUES FOR CAZ070>073 FROM 21Z/24 TO 05Z/25. $$ HTTP://WEATHER.GOV/RENO ca AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RENO NV 215 PM PDT TUE JUL 24 2007 .UPDATE... WILL BE EXPANDING THE FLASH FLOOD WATCH TO COVER ENTIRE CWA WITH AFTERNOON FCST PACKAGE. STORMS DEVELOPING OVER NVZ004 ARE EXHIBITING VERY SLOW STORM MOTION...WITH LOCALLY HEAVY RAINFALL LIKELY. THIS IS CONFIRMED IN THE RUC 0-6KM MEAN WIND FIELDS...WHICH SHOW A RELATIVE MINIMUM (EVEN ZERO) OVER EASTERN SECTIONS OF THE CWA. STORM CURRENTLY EAST OF MIDDLEGATE ON US HIGHWAY 50 HAS LIKELY PRODUCED AT LEAST 0.75" OF RAIN. FURTHER WEST...ESTIMATED STORM MOTIONS NORTH OF TAHOE ALONG SIERRA WILL BE HIGHER PER RUC DATA (10KTS OR SO)...SO THREAT FOR SLOW MOVING CELLS MAY BE MINIMAL THERE. BUT WITH RECENT BURN AREAS (ANGORA/ANTELOPE) ANY APPRECIABLE RAINFALL MAY CAUSE RUNOFF ISSUES. CS && .SHORT TERM... UPPER WAVE OVER CALIF IN CONJUNCTION WITH DESTABILIZATION WILL HELP GENERATE SCT TSRA OVER THE CWA THIS AFTN/EVE. SREF/GFS HIGHLIGHT FAR NRN ZONES ALONG WITH MONO/MINERAL AREAS FOR BEST INSTABILITY...WHICH MAY PAN OUT GIVEN RECENT SATELLITE TRENDS SHOWING BEST CLEARING IN THOSE AREAS. IN FACT...STORMS ARE STARTING TO FIRE OVER TERRAIN IN MONO COUNTY ATTM. SOUNDINGS AND GOES PW PRODUCT SHOWING VALUES NEAR OR ABOVE ONE INCH OVER MOST OF THE CWA (EXCEPT FAR NW)...THEREFORE WITH LIGHT STEERING FLOW THE THREAT FOR HVY RAIN REMAINS. IF CONVECTION CAN DEVELOP OVER NRN ZONES THIS AFTN/EVE...ENHANCED 0-6KM SHEAR MAY HELP ORGANIZE STORMS...OTHERWISE LOOKS LIKE MAINLY PULSE TYPE CELLS ACROSS THE REST OF THE CWA. GFS CONTINUES TO SHOW APPRECIABLE MIDLEVEL MOISTURE TRANSPORT OVERNIGHT AHEAD OF WEAKENING WAVE...THEREFORE WILL CONTINUE CHCS FOR -SHRA OVERNIGHT ACROSS MOST OF THE CWA. WEDNESDAY COULD BE FAIRLY ACTIVE...AS SREF INDICATING PLENTIFUL MOISTURE AND INSTABILITY... ESPECIALLY OVER AREAS EAST OF RENO/CARSON CITY. HAVE INCREASED POPS AS A RESULT...AND GIVEN ANOMALOUSLY HIGH PW VALUES REMAINING IN THE AREA...WILL MENTION LCL HVY RAIN POSSIBLE. WILL NOT ISSUE A SECOND FFA AT THIS TIME...BUT SOMETHING TO RE-EVALUATE DOWN THE ROAD. SIMILAR TO TONIGHT...MOISTURE TRANSPORT SUFFICIENT TO WARRANT CONTINUING POPS FOR -SHRA WED NIGHT ESP IN OUR NV COUNTIES. SWLY FLOW ALOFT PICKS UP A LITTLE ON THURSDAY...ALLOWING FOR DRYING IN THE MIDLEVELS AND INCREASED STABILITY OVER MUCH OF THE WRN CWA. WILL CONTINUE CHC POPS FROM MONO NORTH INTO THE NFL/LOL AREAS...BUT TRIM POPS AS ONE HEADS WESTWARD. SHOULD BE LESS OF A THREAT FOR HVY RAINFALL WITH MOIST PLUME E OF THE AREA. ON FRIDAY...CHCS FOR TS WILL BE CONFINED TO THE FAVORED MONO/MINERAL CONVERGENCE ZONE AREA. SREF SUGGESTS THIS IS LIKELY TO BE THE ONLY AREA WITH SUFFICIENT INSTABILITY TO GENERATE CONVECTION FRI AFTN/EVE. NOT OUT OF THE QUESTION WE COULD SEE SOME VERY ISOLD CELLS DEVELOP OVER PARTS OF CHURCHILL/PERSHING COUNTIES AS WELL WITH AFTN HEATING. SPEAKING OF TEMPS...WE SHOULD EXPECT A WARMING TREND THROUGH THE BALANCE OF THE WEEK...WITH 500MB RIDGE CENTER DRIFTING CLOSER TO THE CWA WITH TIME. CS .LONG TERM...SATURDAY THROUGH TUESDAY... UPPER RIDGE OVER THE FOUR-CORNERS/SOUTHWESTERN US WILL CONTINUE TO DOMINATE THE REGION OVER THE LONG TERM. GFS/ECMWF/UKMET ARE ALL IN GOOD AGREEMENT WITH LONGWAVE PATTERN...INCLUDING AN UPPER LOW MOVING OVER THE PAC NW OVER THE WEEKEND. THIS WILL INCREASE WEST TO SOUTHWESTERLY FLOW ACROSS THE REGION...WHICH WILL DRY US OUT. TEMPERATURES WILL REMAIN IN THE MID TO UPPER 90S ACROSS THE WESTERN NV VALLEYS...WITH MID 80S IN THE EASTERN SIERRA. WITH THE SLIGHT INSTABILITY AND LOCALIZED EFFECTS...EACH AFTERNOON AND EVENING THERE WILL BE A SLIGHT POSSIBILITY FOR AN ISOLATED THUNDERSTORM IN THE MONO-MINERAL COUNTY CONVERGENCE ZONE THROUGH TUESDAY. HOON && .AVIATION... SCTD TSTMS ARE FCST TO DEVELOP OVER MUCH OF THE AREA AFTER 18Z LASTING UNTIL AROUND 04Z. EXPECT LOCALIZED HEAVY RAIN ALONG WITH GUSTY DOWNDRAFT WINDS WITH THESE STORMS. HOON && .REV WATCHES/WARNINGS/ADVISORIES... NV...FLASH FLOOD WATCH CONTINUES FOR NVZ001>005 FROM 21Z/24 TO 05Z/25. CA...FLASH FLOOD WATCH CONTINUES FOR CAZ070>073 FROM 21Z/24 TO 05Z/25. $$ HTTP://WEATHER.GOV/RENO ca AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 233 PM EDT TUE JUL 24 2007 .SHORT TERM...SFC DATA SHOWS WEAK FRONTAL TROUGH IS ORIENTED FROM NEAR JAX TO VALDOSTA WITH MOST OF THE CONVECTION DEVELOPING NEAR AND JUST N OF THE IT. RUC MODEL SHOWS A FEW DISTURBANCES ALOFT WITH ONE OVER N CENTRAL FL AND MORE SIGNIFICANT VORT MAX OVER THE WRN FL PANHANDLE. TEMPS HELD DOWN CURRENTLY IN THE MID 80S DUE TO CLOUDS AND PRECIP. ANTICIPATE A FEW STRONG TO SEVERE STORMS REST OF THIS AFTERNOON GIVEN ENOUGH SFC HEATING AND BOUNDARY COLLISIONS. .SHORT TERM (TONIGHT-FRI)...LOW LEVEL RIDGE AXIS WILL REMAIN S OF THE AREA MAINTAINING A S TO SW FLOW OVER THE REGION. RICH MOISTURE COMBINED WITH INSTABILTIY WILL WARRANT SCT TO NUMEROUS SHWOERS AND STORMS IN SHORT TERM PERIOD. TONIGHT...WEAK FRONTAL TROUGH WILL LIFT NWD WITH SCT CONVECTION SLOWLY WINDING DOWN BECOMING ISOLD AFTER MIDNIGHT. ADDITIONAL SUPPORT FROM SHORTWAVE WILL ALSO BECOME LESS OF A FACTOR AS IT DE- AMPLIFIES AND LIFTS NEWD. WEDNESDAY...SE TO S LOW LEVEL WINDS AND PRECIP WATER AROUND THE 2 INCH MARK SUGGEST HIGH END CHANCE TO LIKELY POPS. ALSO SUPPORTIVE IS DEEPER LAYER VORT ADVECTION MOVING SW TO NE BY LATER IN THE DAY. OVERALL PREFERRED GFS HIGHER POPS BASED ON RECENT PERFORMANCE BUT DIDN`T WANT TO GO AS HIGH (ALMOST CATEGORICAL). WEDNESDAY NIGHT...SCT CONVECTION SHOULD SLOWLY DISSIPATE BUT CAN`T RULE OUT STRAY SHOWER OR THUNDERSTORM LATE. THURSDAY...MEAN RH LEVELS REMAIN FAIRLY HIGH WITH PRECIP WATER JUST UNDER 2 INCHES. ALTHOUGH FAIRLY GOOD DEEP LAYER LIFT IS NOTED IN GFS RUN...UPPER LEVELS WILL WARM SLIGHTLY AS MID-UPPER RIDGE BUILDS NWD OVER CENTRAL FL. WILL KEEP POPS AROUND THE 40-60% RANGE WITH HIGHEST OVER FL ZONES. FRIDAY...SLIGHT CHANGE IN PATTERN AS UPPER TROUGH BECOMES MORE BROAD ACROSS SE STATES ALLOWING MEAN MID LEVEL FLOW TO BECOME MORE WLY. THIS MAY OPEN THE DOOR FOR FAST MOVING IMPULSES RIDING THROUGH BASE OF TROUGH. AT THIS TIME MOS POPS LOOK A LITTLE HIGH BUT WILL CARRY HIGH END CHANCE POPS ALL ZONES. TEMPS DURING THE PERIOD LOOK TO BE 1-2 DEG BELOW NORMAL. .LONG TERM (SAT-TUE)...MID TO UPPER TROUGH DOMINATES THE ERN AND SE U.S. DURING THE EXTENDED. IN FACT TROUGH APPEARS TO AMPLIFY WITH TIME OVER THE WEEKEND. AT SFC...RIDGE ACROSS N CENTRAL FL WILL SHIFT GRADUALLY SWD TOWARD SRN TIP OF FL AS MID-UPPER RIDGE OVER SRN FL AND SRN GULF OF MEXICO GETS SHUNTED SWD. MEAN FLOW REMAINS OUT OF THE SW AND W AND JUDGING FROM GFS MOISTURE LEVELS REMAIN NEAR TO ABOVE AVERAGE. THUS...IT SEEMS VERY REASONABLE TO CONTINUE WITH AT LEAST CLIMO-TYPE POPS WITH LIKELY POPS A POSSIBILITY...ESPECIALLY DURING THE WEEKEND...AGAIN. SHORTWAVE ENERGY IN NW FLOW MAY HELP SUPPORT A BRIEF PERIOD OF STRONG OR SEVERE STORMS FROM SAT-MON MAINLY NRN ZONES. NEAR NORMAL TEMPS EXPECTED WITH A FEW AREAS POSSIBLY BELOW NORMAL DUE TO CLOUD COVER AND/OR PRECIP. && .AVIATION...MOSTLY VFR CONDITIONS TONIGHT WITH TEMPO MVFR/IFR DUE TO SCATTERED SHOWER AND THUNDERSTORM ACTIVITY. HEAVY DOWNPOURS WILL LOWER VSBYS TO 2SM OR LESS WITH CIGS LOWERING TO AROUND 2KFT MAINLY THIS AFTERNOON AND EARLY EVENING. EAST TO SOUTHEAST WINDS THIS EVENING WILL BECOME SOUTH TO SOUTHWEST ON WEDNESDAY. && .MARINE...ONSHORE FLOW TONIGHT WILL BECOME SOUTH TO SOUTHWEST AT 15 KNOTS OR LESS WEDNESDAY THROUGH SUNDAY. SEAS WILL REMAIN IN 2 TO 4 FOOT RANGE. && .PRELIMINARY POINT TEMPS/POPS... AMG 69 90 70 91 / 30 50 30 50 SSI 74 86 75 87 / 30 50 40 40 JAX 70 89 71 90 / 40 60 40 50 SGJ 72 87 73 88 / 40 60 40 50 GNV 70 90 70 91 / 40 60 30 60 OCF 70 90 71 91 / 40 60 30 50 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ SHASHY/ZIBURA/MCALLISTER fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 220 PM MDT TUE JUL 24 2007 .DISCUSSION...17Z WATER VAPOR IMAGERY/RUC ANALYSIS INDICATED H5 RIDGE CENTERED ACROSS WESTERN NEBRASKA AND WESTERN SOUTH DAKOTA. SHORT WAVE TROUGH WAS NOTED SLIDING SOUTH ALONG THE NORTHERN PERIPHERY OF THE RIDGE. AT THE SFC...PRESSURE FIELD WAS FAIRLY WEAK ACROSS THE CWA WITH SFC RIDGE TO THE EAST AND A TROUGH DEVELOPING ACROSS THE WESTERN HIGH PLAINS. NO REAL APPARENT SFC FEATURES WERE NOTED ACRS THE CWA...ALTHOUGH AREA OF SFC CONVERGENCE WITH AN AREA OF CU WAS NOTED JUST TO THE NORTHWEST OF THE CWA. SHORT RANGE MODELS ARE IN FAIRLY GOOD AGREEMENT...BUT DIFFERENCES BEGIN TO EMERGE WITH HANDLING OF RIDGE. NAM APPEARS TO BE THE LEAST AMPLIFIED WITH GFS LOOKING SIMILAR TO THE SREF MEAN...SO WILL LEAN TOWARDS THIS DIRECTION THROUGH THE LATER PORTIONS OF THE FORECAST. TONIGHT...FIRST CONCERN WILL BE WHETHER OR NOT AN ISOLATED THUNDERSTORM CAN DEVELOP THIS AFTERNOON. MORNING SOUNDING INDICATE THAT EXPECTED MAX TEMPS WILL BE ENOUGH TO REMOVE ANY CINH...BUT THERE IS A NOTICEABLE LACK OF ANY STRONG...OR PERSISTENT SFC FORCING. WEAK SHORT WAVE TROUGH WILL BE MOVING OVER THE AREA AROUND 00Z...WHICH MAY PROVIDE ENOUGH LIFT TO FIRE OF A STORM OR TOO...BUT PLAN ON WAITING TO SEE HOW AFTERNOON DEVELOPS BEFORE MAKING A FINAL DECISION. OTHERWISE H5 RIDGE AXIS WILL SLOWLY SHIFT SOUTH OVERNIGHT LEADING TO LARGE SCALE SUBSIDENCE. WINDS SHOULD REMAIN UP THROUGH THE NIGHT SO DO NOT EXPECT FOR THINGS TO COOL OFF AS MUCH AS LAST NIGHT...SO KEPT LOWS IN THE 60S. TOMORROW/TOMORROW NIGHT...H5 RIDGE WILL CONTINUE TO BE CENTERED OVER THE AREA LEADING TO CONTINUED LARGE SCALE SUBSIDENCE. CONVECTION SHOULD DEVELOP ALONG THE FRONTAL BOUNDARY TO THE NORTH AND EAST OF THE AREA OVERNIGHT. FRONTAL BOUNDARY MAY BE NEARING YUMA COUNTY IN THE EVENING...BUT STORM MOTIONS SHOULD BE NEARLY STATIONARY SO DO NOT ANTICIPATE STORMS MAKING A LARGE PUSH INTO THE CWA. A DECENT LLJ DEVELOPS OVERNIGHT...BUT LITTLE IF ANY INSTABILITY APPEARS AVAILABLE TO ELEVATED PARCELS SO WILL LEAVE FORECAST DRY. BOTH THE GFS AND NAM SHOW DEEP MIXED LAYER DEVELOPING DURING THE AFTERNOON AND SUGGEST TDS WILL FALL OFF INTO THE UPPER 40S/LOW 50S. WITH TEMPS IN THE MID/UPPER 90S THIS WILL DRIVE RHS TO THE 15-20% RANGE IN THE WEST. WINDS SHOULD REMAIN FAIRLY LIGHT SO DO NOT ANTICIPATE ANY KIND OF FIRE WX HIGHLIGHT THURSDAY-THURSDAY NIGHT...GFS...NAM AND SREF ALL FAIRLY CLOSE WITH TIMING OF FROPA...WITH SREF BEING A BIT FASTER THAN...BUT SIMILAR IN ORIENTATION TOO THE GFS. MAIN CONCERN FOR THIS PERIOD WILL BE PRECIPITATION CHANCES. AS MENTIONED BEFORE...PREFER GFS/SREF TIMING AND ORIENTATION OF THE FRONT WHICH WILL BE MOVING ACROSS THE AREA DURING AND AFTER PEAK HEATING. AM A LITTLE CONCERNED THAT BULK OF THE INSTABILITY IS BEHIND THE FRONT...WHICH MAY KEEP COVERAGE MORE SCATTERED AND PREVENT A SOLID LINE...AS INSTABILITY WILL NOT BE COLOCATED WITH STRONGEST SFC FORCING. OVERALL WILL KEEP 30-40 POPS GOING DURING THE AFTERNOON AND INTO THE EVENING. MODELS KEEP PRECIPITATION GOING OVERNIGHT...BUT CANT SEEM TO FIND A LOT OF FORCING TO SUPPORT THAT SO WILL CONFINE POPS TO AREA AROUND FRONT. FRIDAY...HOW FAST THE COOLER AIR BUILDS INTO THE AREA. NAM AND GFS BRING THE COOLER AIR IN DURING THE MORNING HOURS...SWEEPING AWAY ANY SFC BASED INSTABILITY WELL BEFORE PEAK HEATING. SREF EVEN COLDER...WITH MEAN MAX TEMPS ONLY IN THE 70S IN A FEW LOCATIONS. WILL TREND DOWN TEMPS SEVERAL DEGREES...BUT WILL HOLD OFF REALLY HOLDING BACK TEMPS TO SEE IF MODEL AGREEMENT KEEPS UP. FOR POPS...IF COOLER AIR WORKS IN QUICKER DONT SEE A LOT OF HOPE FOR SFC BASED CONVECTION EXCEPT FOR FAVORED UPSLOPE FLOW AREAS. HOWEVER...MODELS STILL HAVE SOME ELEVATED INSTABILTY WITH WEAK H7-H6 WAA AREA SWEEPS ACROSS THE AREA SO DESPITE THE UNCERTAINTY WITH THE FRONT...WILL KEEP LOW POPS THROUGH THE DAY. .IN THE EXTENDED...H5 RIDGE WILL SHIFT TO THE SOUTH AS COLD FRONT SWEEPS ACROSS THE AREA EARLY IN THE PERIOD. MAIN CONCERN FOR THIS PERIOD WILL BE TEMPS AS THERE IS QUITE A RANGE BETWEEN GFS AND ECMWF WITH RESPECT TO TEMPS BEHIND THE FRONT. ECMWF IS AROUND 5C COOLER THAN OPERATIONAL GFS RUNS...AND GFS 06Z ENSEMBLE VARIANCES ARE THE HIGHEST IN THE FRI-SUN PERIOD SO CONFIDENCE IN ANY ONE SOLUTION IS LOW. BASED ON FRONTAL POSITION AND EXPECTED EASTERLY FLOW...DID KNOCK MAX TEMPS A FEW DEGREES...AND LOWERED MIN T`S SEVERAL DEGREES AS AIRMASS BEHIND THE FRONT SHOULD BE A BIT DRIER AND LIGHT WINDS SHOULD ALLOW FOR A LARGER DIURNAL RANGE...AND MAY STILL BE A TAD TOO WARM. WITH SUCH UNCERTAINTY WITH FRONTAL INTENSITY AND TIMING...HARD TO GET TO EXCITED FOR POPS...AND KEPT POPS 30 PERCENT OR LESS THROUGH THE PERIOD. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ JRM ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 102 PM EDT TUE JUL 24 2007 .AVIATION (FOR 18Z TAFS)... UPPER-LEVEL LOW SPINNING OVER OHIO COMBINED WITH A SFC TROUGH EXTENDING FROM WRN TN TO ERN KY WILL HELP GENERATE ISLD-SCT SHRA/TSRA THIS AFTERNOON AND EVENING. WITH THE UPPER LOW SPINNING CLOSER TO THE AREA OVERNIGHT...AN ISOLATED SHOWER OR TWO WILL BE POSSIBLE DURING THE NIGHTTIME HOURS...TOO...BUT WILL BE SO WIDELY SCATTERED THAT WE WILL NOT INCLUDE THIS IN THE TAFS. HOWEVER FROM 19 OR 20Z THROUGH 01 OR 02Z...ISLD SHRA/TSRA WILL BE POSSIBLE MAINLY AT THE LEX TAF SITE AND POSSIBLY AT BWG. WILL INCLUDE A FEW HOURS OF VCTS OR VCSH AT LEX...AND POSSIBLY BWG TOO. WITH ANY STORM NEAR LEX...SMALL HAIL AND GUSTY WINDS WILL BE POSSIBLE...BUT WILL LIKELY LEAVE OUT THESE THREATS FROM THE LEX TAF BASED ON THE HIGHLY ISOLATED NATURE OF THE STORMS. AGAIN WITH LOW-LEVEL MOISTURE PRESENT AND LIGHT WINDS EXPECTED OVERNIGHT...COULD HAVE MVFR VSBYS TOWARD 12Z WEDNESDAY...ESPECIALLY AT LEX AND BWG. A BETTER CHANCE OF SCT SHRA/TSRA EXISTS ON WEDNESDAY...BUT SINCE THIS TAF PERIOD ENDS AT 18Z...WE MAY LEAVE OUT THE MENTION OF VCTS FOR NOW. AL && .PREVIOUS DISCUSSION... LATE MORNING UPDATE... CURRENT FORECAST IS IN GOOD SHAPE. HAVE MADE MINOR ADJUSTMENTS TO DEWPOINTS FOR THIS AFTERNOON AND HAVE RAISED TEMPERATURES A DEGREE OR TWO OVER THE EAST. MORNING ACARS SOUNDINGS FROM SDF INDICATE THUNDERSTORM ACTIVITY SHOULD NOT DEVELOP OVER THE WESTERN PORTION OF THE FORECAST AREA SO WE WILL KEEP THE WEST DRY AND CHANCE POPS OVER THE FAR EAST. --MB SHORT TERM (TODAY AND TONIGHT)... FCST CONCERN DURING THE SHORT TERM CENTERS ON TSTM CHANCES THIS AFTERNOON AND EVENING ASSOCIATED WITH UPR LOW...WHICH CURRENTLY IS CENTERED NEAR THE OH-WV STATE BORDER. THIS LOW IS SPINNING HIGH AND SOME MID-LEVEL MOISTURE SWWD INTO OH VALLEY...BUT RADAR SHOWS NO PRECIP ACROSS CNTRL KY AND S-CNTRL IN AT THIS TIME. NAM...GFS...AND RUC MODELS FCST LITTLE OVERALL MOVEMENT OF UPR LOW THRU THIS EVENING. A MESO SFC ANALYSIS AT 06Z SHOWED A SFC TROF ALIGNED SW-NE OVER CNTRL KY. CONVECTION ON MONDAY AFTERNOON OCCURRED MAINLY S OF THIS AXIS ALONG AN APPARENT OUTFLOW BOUNDARY AND IN CONJUNCTION WITH TERRAIN OVER SERN KY AND ERN TN. WITH UPR LOW NOT MOVING ALL THAT MUCH TODAY AND WITH CURRENT WATER VAPOR IMAGERY NOT SHOWING ANY DEFINITIVE SHORTWAVES ROTATING AROUND LOW...FEEL THAT ISOLD TO SCT TSTMS THIS AFTERNOON AND EVENING WILL BE CONFINED TO E-CNTRL AND ERN PART OF S-CNTRL KY...ROUGHLY ALONG AND E OF A FFT TO GLASGOW LINE. THIS AXIS WILL BE ALONG AND S OF WEAK SFC BOUNDARY...AND IT ALSO ALIGNS WITH QPF AND INSTABILITY AXIS FROM GFS AND RUC. ON THE OTHER HAND...NAM APPEARS TO SHOW ITS TYPICAL HIGH BIAS OF SFC DEPWTS AND RESULTING GREATER SFC BASED INSTABILITY...THEREBY ALLOWING SCT CONVECTION TO OCCUR FARTHER W OVER CNTRL KY. AS WAS THE CASE YESTERDAY...BEST TSTM COVERAGE SHOULD AGAIN OCCUR OVER ERN/SERN KY THIS AFTERNOON. ANY TSTM ACTIVITY SHOULD DISSIPATE TONIGHT OVER ERN PARTS OF CNTRL KY. CONTINUED MID/HIGH LEVEL MOISTURE WILL KEEP SKY PARTLY CLOUDY. MOS GUIDANCE TEMPS TODAY AND TONIGHT ARE WITHIN A FEW DEGREES OF EACH OTHER AND SEEM REASONABLE. TWF LONG TERM (WEDNESDAY THRU MONDAY)... MEANDERING UPR LOW ACRS THE ERN OH VLY AT THE START OF THIS PERIOD FCST BY BOTH NAM/GFS TO WOBBLE NWWD TO THE LOWER GREAT LAKES THU WHILE FILLING. AFTERWARD...LOW OPENS TO A TROF FROM THE GREAT LAKES INTO THE OH VLY (NAM) OR TRANSITIONS ENE WITH TROF FARTHER EAST ACRS THE ERN OH VLY FRI (GFS). THE GFS SOLUTION IS IN BETTER AGREEMENT WITH THE NEW RUNS OF THE ECMWF AND ENSEMBLE MEANS AND WILL BE FOLLOWED FOR THE THU/FRI PERIOD. BOTH MODELS SHOW WEAK SFC/LO LEVEL SLY FLO/CONTD MSTR TRANSPORT INTO OUR FA WED...HOWEVER...LITTLE IN THE WAY OF FORCING...OTHER THAN POSITIONING OF UPR LO/STEEPER LAPSE RATES...AS WEAK SFC TROF BECOMES DIFFUSE. OUR CURRENT FCST OF 20 POPS WRN FA AND 40 ERN AREAS LOOK O.K. BASED ON DEEPER MOISTURE PROGGED EAST BY THE MODELS...WILL HOLD OFF TIL AFTN PER STEEPENING LAPSE RATES. WILL CONTINUE A DIURNAL DOWNWARD TREND WED NIGHT...KEEPING POPS ONLY THRU THE EVENING. FROM THU ON...WILL GENERALLY FOLLOW GFS/ENSEMBLE MEANS/ECMWF WITH A NLY COMPONENT OF UPR LOW MOVEMENT RESULTING IN A DECREASING POP TREND FOR ALL EXCEPT OUR NRN/NERN FA...CLOSEST TO PROGGED UPR LO POSITION. THIS CONSISTENT WITH HPCS PLACEMENT OF HIER QPF FOR THU AND ENSEMBLE MEANS/ECMWF PLACEMENT OF DEEPEST MOISTURE FRI. SCT TSTMS TO REMAIN IN THE FCST FOR THE WEEKEND AS A CDFNT REACHES THE UPR OH VLY SAT AND OUR FA EARLY SUN...EXITING OUR SRN FA SUN NGT. WILL KEEP TEMPS PRETTY MUCH WHERE THEY ARE NOW FOR THIS LONG RANGE PD AFTER EXAMINING MEX MOS. DK && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ ky AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 102 PM CDT TUE JUL 24 2007 .UPDATE...FOR 18Z AVIATION DISCUSSION. && .PREVIOUS DISCUSSION.../ISSUED 340 AM CDT TUE JUL 24 2007/ EXTENSIVE CLOUDINESS BLANKETS WEST CENTRAL WI AND PORTIONS OF EAST CENTRAL AND SOUTH CENTRAL MN EARLY THIS MORNING. THE CLOUDINESS HAS ACTUALLY INCREASED IN COVERAGE OVER THE PAST FEW HOURS. 310K THETA SURFACE SHOWING UPGLIDE FROM THE NORTH ACROSS NORTHERN AND WEST CENTRAL WI WITH SOME ADIABATIC OMEGA. MODEL GUIDANCE INDICATING RATHER EXTENSIVE LAYER MOISTURE BELOW 700 MB THROUGH THE DAY. HAVE CUT BACK ON HIGHS OVER WEST CENTRAL WI...THE MSP METRO AREA AND SOUTHWARD ALONG I-35. IF THE CLOUDS STAY...CURRENT HIGH TEMPERATURE FORECAST WILL BE TOO HIGH...IF THE CLOUDS GO... FORECAST WILL BE TOO LOW. TO OUR NORTHWEST...CONVECTIVE COMPLEX CONTINUES TO GROW OVER NE ND. SOME ACTIVITY STARTING TO GET SOUTH OF KFGF ATTM. 850-300MB THICKNESS WOULD HEAD THE ACTIVITY TOWARD OUR NW CWA. 21Z SREF HAD A GOOD HANDLE ON THIS FEATURE. 03Z SREF MAINTAINS THE COMPLEX AND PUSHES IT TOWARD KDLH BY 21Z. THE THUNDERSTORMS ARE ALONG AND NORTH OF ABOUT +13 DEG C AT 700MB. THE RUC TRIES TO MAINTAIN +14 OVER WEST CENTRAL THROUGH CENTRAL MN THROUGH MIDDAY. PLANNING ON GOING DRY ATTM...BUT WILL HAVE TO KEEP AN EYE ON THIS FEATURE EARLY THIS MORNING. HIGHS TODAY FOR WESTERN MN LOOK TO AROUND 93 TO 95 DEGREES IF THIS COMPLEX STAYS AWAY. RAISED DEW POINTS ABOUT 2 DEGREES IN THE GRIDS FOR THE NEXT SEVERAL DAYS ALL AREAS. RESULTING HEAT INDEX VALUES IN THE 100-104 RANGE FOR WEST CENTRAL TODAY AND IN THE 104-107 RANGE ON WEDNESDAY. LITTLE CHANGE TO THE HIGHS FOR WEDNESDAY AND THURSDAY. ONE CHANGE IN THE FORECAST WAS WITH THE PRECIP FORECAST THURSDAY AND THURSDAY NIGHT. DIVIDED THE FORECAST INTO 6 HOUR WINDOWS AND INCREASE POPS INTO THE HIGH CHANCE CATEGORY...MAINLY OVER THE EASTERN AND SOUTHERN CWA. PRETTY GOOD AGREEMENT BETWEEN THE NAM/GFS AND 03Z SREF THAT A FROPA WILL OCCUR BY DAYBREAK FRIDAY. ONE TROUBLING FEATURE SEEN FOR LATE THURSDAY IS THAT PRECIPITABLE WATER VALUES INCREASE TO NEARLY 2.25 INCHES FOR MUCH OF OUR CWA ON BOTH THE NAM AND GFS WITH A 6 HOURLY INCREASE OF OVER HALF AN INCH. WHEN IT FINALLY RAINS...ITS GOING TO POUR. HIGH PRESSURE AND LOWER AFTERNOON HUMIDITY SPREADING IN FOR THE UPCOMING WEEKEND. && .AVIATION.../18Z TAF CYCLE 12Z MPX RAOB INDICATED A FORMIDABLE INVERSION BETWEEN 800 AND 700 MB WHICH APPEARS TO BE ACTING AS A GOOD CAP FOR CONVECTIVE DEVELOPMENT OVER EASTERN MN AND WESTERN WISCONSIN. SOME TOWERS WENT UP EARLIER THIS MORNING IN SOUTH CENTRAL MN BUT THEY DID NOT REALLY DEVELOP MUCH PAST 15 KFT AND HAVE SINCE WEAKENED. OLD AREA OF CONVECTION IS WORKING SOUTHWARD AND WE HAVE CONVECTION MENTIONED FOR AT LEAST VICINITY FOR BOTH KSTC AND KAXN. 3-5 MILE VISIBILITIES IN GROUND FOG AGAIN LIKELY AFTER 09Z AT MOST SITES GIVEN THE HISTORY OF THIS AIRMASS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ mn AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE DULUTH MN 1202 PM CDT TUE JUL 24 2007 .UPDATE... ADDED ISOLATED SHOWERS AND THUNDERSTORMS TO AREAS AGAINST THE CANADIAN BORDER FOR TODAY. && .DISCUSSION... ISOLATED WEAK SHOWERS ALONG AN OLD CONVECTIVE OUTFLOW BOUNDARY SEEM TO BE MOVING SLOWLY SOUTH BETWEEN LITTLEFORK AND CRANE LAKE ATTM. IF THESE PERSIST...THEY MAY EVENTUALLY MAKE IT INTO THE ORR...TOWER AND ELY AREA. WITH THE STRONG CAP...UPWARD DEVELOPMENT WITHIN THE SHOWERS IS VERY LIMITED...BUT IN THE TROPICAL-TYPE LOW LEVELS THERE DOESN/T HAVE TO BE MUCH DEPTH NOR ANY GLACIATION FOR RAIN TO OCCUR. SO...WE ADDED ISOLATED SHOWERS OR THUNDERSTORMS TO THE FORECAST FOR TWO REASONS...ONE OF THE SHOWERS MAY BREAK THE CAP AND OLD...STALE CONVECTIVE COMPLEX SEEMS TO BE MAINTAINING ITSELF MOVING UP THE RED RIVER VALLEY...WELL TO OUR WEST...IN AN EVEN STRONGER CAP. && .AVIATION... ISOLD IFR CONDS ARE PSBL IN THE INL AREA THIS AFTN. ATTM WE DO NOT ANCPT CNVCTN THERE TO CONT INTO THE EVE. && .PREV DISCUSSION... /ISSUED 1046 AM CDT TUE JUL 24 2007/ UPDATE... TOOK FOG OUT FOR THIS MORNING...ELIMINATED PRECIPITATION TODAY AND CHANGED THE FORECAST TO AREAS OF FOG LATE TONIGHT AND EARLY WEDNESDAY. DISCUSSION... A CAP...DEFIINED CRUDELY AS ABOVE 10C AT 700 MB FOR THE PURPOSES OF AN AREAL PERSPECTIVE...COVERS OUR ENTIRE FORECAST AREA. CONVECTION FEEDING ON LOCALLY GREATER MOISTURE AND AN EARLIER BROKEN CAP JUST NORTH OF THE BOUNDARY WATERS AREA SEEMS TO BE HAVING TO DO TOO MUCH WORK AGAINST THE GROWING CAP SO...IN SPITE OF STRONG SUNSHINE...SEEMS TO BY DYING. PRIND LIGHT RAIN FROM DYING CONVECTION TO OUR WEST WILL NOT REACH OUR FORECAST AREA. THAT CONVECTION SEEMS TO BE HOLDING TOGETHER...SEVERAL COUNTIES WEST OF OUR AREA OVER THE UPPER RED RIVER. SO...WE HAVE KEPT THINGS DRY THROUGH THE AFTERNOON AND EVENING. TRAPPED BY THE CAP IS SURFACE TEMPERATURES THAT WILL APPROACH OR REACH 35C INLAND AND DEW POINTS AS HIGH AS THE 22C TO 24C RANGE. THAT CAP IS PROTECTING US FROM REAL CONVECTIVE TROUBLE...THERE IS PLENTY OF ENERGY THERE. WITH INVERSIONS IN PLACE AND MOISTURE FLUX DOWNWARD...WE ANCPT PLENTY OF RADIATION FOG TONIGHT. WITH THE LAKE RELATIVELY COOL AND EVEN MORE INVERSIONS OVER THE WATER...WE ALSO ANCPT SIGNIFICANT DENSE MARINE FOG TO PERSIST. AVIATION... WDSPRD LIFR IN GNDFG WL DVLP AGN TNGT AND PRST INTO WED MRNG. OTRW...VFR CONDS WL PVL. PREV DISCUSSION... /ISSUED 310 AM CDT TUE JUL 24 2007/ DISCUSSION...MCS IN NE ND ATTM AND ITS IMPACT ON THE NW QUAD OF THE FA THE CONCERN FOR THE SHORT TERM. 00Z MODELS ARE TOO FAR E WITH THE SHORT WAVE THAT IS MOVING THROUGH MOVING ALONG THE INTERNATIONAL BORDER. 06Z RUC ALSO OVERDOING IT...BUT HAS THE MCS WEAKENING BEFORE REACHING THE FA WITH NO PCPN. DID HOWEVER ADD A SMALL POP THIS MORNING FOR THE POSSIBILITY IT MAY MAKE IT THAT FAR E. OVER THE REST OF THE FA...SFC RIDGING COVERS THE AREA. LOWS CLOUDS AND FOG ARE DEVELOPING/SPREADING OVER THE FA. FOG ALSO A FACTOR OVER THE SOUTHERN HALF OF MN FA WITH MZH ALREADY AT 1/2 MILE. WILL MONITOR CLOSELY FOR DENSE FOG POTENTIAL EARLY. THE ND SHORT WAVE IS PROGGED TO DROP SEWD AND INTO THE FA TODAY. HOWEVER...MODELS ARE NOT GENERATING ANY QPF. WILL KEEP GRIDS RAIN FREE THIS AFTERNOON...BUT LOW CONFIDENCE. HOT AND HUMID CONDITIONS TODAY...APPARENT TEMPERATURE APPROACHES HEAT ADVISORY CRITERIA OVER CROW WING...SOUTHERN CASS AND AITKIN COUNTIES THIS AFTERNOON. NO HEADLINES ATTM...BUT WILL MENTION TO NEXT SHIFT. LITTLE CHANGE IN THE ATMOSPHERE OVER THE FA TONIGHT AND EXPECT PATCHY FOG TO DEVELOP AFTER MIDNIGHT AGAIN. UPPER LEVEL LOW THAT HAS BEEN AFFECTING THE E COAST WILL RETROGRADE INTO THE LOWER GREAT LAKES WEDNESDAY. MEANWHILE...A COLD FRONT WILL APPROACH FROM THE W AIDED BY AN UPPER LEVEL SHORT WAVE. MODELS DIFFER ON WHETHER THUNDERSTORMS WILL BREAK OUT IN NW WI IN THE AFTERNOON. WILL KEEP WITH PERSISTENCE AND NOT MENTION RAIN FOR NOW. APPROACHING SYSTEMS BEGIN TO CONVERGE ON THE FA WEDNESDAY NIGHT WITH THUNDERSTORMS DEVELOPING. TIMING AN ISSUE AT THIS POINT AND HAVE LEFT GRIDS AS IS. BETTER CHANCES FOR RAIN THURSDAY AND FRIDAY AS THE COLD FRONT PUSHES THROUGH. COOLER AND DRIER CONDITIONS EXPECTED FRIDAY NIGHT INTO MONDAY. AVIATION...ABUNDANT LOW LEVEL MOISTURE WILL CONTINUE TO RESULT IN AREAS OF MVFR/IFR CONDITIONS WITH FOG THROUGH EARLY MORNING. CONDITIONS SHOULD IMPROVE TO VFR ACROSS MUCH OF THE NORTHLAND BY MID MORNING WITH SCT-BKN MID LEVEL CU. HOWEVER...MVFR CIGS MAY PERSIST ACROSS PORTIONS OF NW WI THROUGH MID DAY. AREAS OF FOG LOOK TO REDEVELOP ACROSS THE ENTIRE FORECAST AREA LATE TONIGHT. && POINT TEMPS/POPS... DLH 85 65 86 63 / 10 10 10 20 INL 93 68 95 66 / 20 10 10 30 BRD 94 69 95 70 / 10 10 10 20 HYR 93 65 93 66 / 10 10 10 10 ASX 83 64 86 64 / 10 10 10 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. $$ EOM/TL mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 1235 AM CDT TUE JUL 24 2007 ...UPDATED AVIATION... .DISCUSSION... QUICK ADJUSTMENT TO THE FORECAST THIS MORNING FOR ISOLATED POPS IN EASTERN KANSAS AND EXTREME NORTHWEST MISSOURI. MOISTURE AXIS THIS MORNING WAS/IS LOCATED JUST WEST OF THE KANSAS MISSOURI STATE LINE. VERTICAL CU WAS EVIDENT ON VISIBLE SATELLITE IMAGERY AND WAS SLOWLY ADVECTING EAST UNDER THE INFLUENCE OF WEAK WESTERLIES AT 850MB. SURFACE BASED CAPE VALUES JUMP OVER 1500 J/KG THIS AFTERNOON IN EASTERN KANSAS THIS AFTERNOON ON THE RUC/GFS/NAM MODELS. WITH LITTLE TO NO CAP IN PLACE SOME SMALL ISOLATED STORMS HAVE ALREADY BEEN NOTED PERCOLATING ACROSS EAST KANSAS ALREADY THIS MORNING. RESTRICTED THE POPS TO EASTERN KANSAS AND NORTHWEST MISSOURI AS SURFACE HIGH CENTERED TO OUR EAST...AND WEAK WINDS ALOFT...WILL LIMIT THE ABILITY OF THE STORMS TO MOVE PAST MUCH THE STATE LINE. CUTTER && .PAST DISCUSSION... /316 AM CDT TUE JUL 24 2007/ AREAS OF PATCHY FOG AND STRATUS DEVELOPING THIS MORNING ATOP SATURATED SOIL FROM YESTERDAYS RAIN. EXPECTING THIS TO BURN OFF AND BREAK UP DURING THE MORNING HOURS WITH CU DEVELOPING BY LATE MORNING/EARLY AFTERNOON...MORE SO ACROSS THE WESTERN CWA WHERE MORE ABUNDANT LOW LEVEL MOISTURE RESIDES. SYNOPTICALLY...AREA REMAINS TRAPPED BETWEEN STUBBORN UPPER RIDGE TO THE NW AND UPPER LOW TO THE EAST. WITH THE ABSENCE OF A DECENT SHORT WAVE TO SPARK CONVECTION...NOT OVERLY IMPRESSED WITH PRECIP CHCS TODAY. WILL LIKELY SEE MODEST INSTABILITY ACROSS THE WESTERN CWA WHERE HIGHER LLVL MOISTURE IS CONFINED. HOWEVER...WITH DECENT WARM NOSE NEAR H7 AND LACK OF SFC FOCUS FOR INITIATION...SHOULD SEE CONVECTION KEPT AT BAY THROUGH THE AFTERNOON. OTHERWISE...MAIN CONCERN TODAY WILL BE WITH AFTERNOON TEMPS. SHOULD SEE 16-18C H85 TEMPS ACROSS THE AREA WITH THE WARMER READINGS ACROSS NW MO AND HAVE THEREFORE TAILORED ACCORDINGLY. NEXT POTENTIAL FOR PRECIP WILL BE WEDNESDAY NIGHT AS MODELS HINT AT A WEAK IMPULSE ROUNDING THE UPPER RIDGE AND TRAVERSING THE AREA ON THE BACK SIDE OF GREAT LAKES UPPER LOW. MUCH DISCREPANCY WITH REGARDS TO HOW THIS WILL EVOLVE...AND LEANED TOWARD GFS ENSEMBLE OUTPUT KEEPING THINGS DRY FOR THE TIME BEING UNTIL BETTER CONTINUITY IS REALIZED. OTHERWISE...RAISED TEMPS A FEW DEGREES EACH DAY FOR THE NEXT FEW DAYS AS H85 TEMPS SLOWLY CLIMB. THE REMAINDER OF THE FORECAST LOOKS TO BE ON TRACK AND NO CHANGES MADE BEYOND DAY 3. DEROCHE && .AVIATION... CU FIELD HAS SPREAD EAST THIS MORNING ALONG WITH A MOISTURE AXIS THAT STARTED THE DAY WEST OF THE KANSAS/MISSOURI STATE LINE. CEILING HEIGHTS FROM THIS DECK ARE LOOKING TO RANGE AT OR ABOVE 3500 FEET...IN THE VFR RANGE. WILL KEEP VFR CONDITIONS GOING AT THE TERMINALS THROUGH THE NEXT 24 HOURS AS THE SURFACE HIGH TO OUR EAST KEEPS RELATIVELY DRY AIR IN PLACE ACROSS THE TERMINALS TONIGHT. DID ADD SOME MVFR VISIBILITIES TO KSTJ AS TEMPERATURES OVERNIGHT WILL DROP OFF IN THE DRY AIRMASS...RESULTING IN SOME HAZE NEAR THE TERMINAL. CUTTER && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. $$ mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 1135 AM CDT TUE JUL 24 2007 .DISCUSSION... QUICK ADJUSTMENT TO THE FORECAST THIS MORNING FOR ISOLATED POPS IN EASTERN KANSAS AND EXTREME NORTHWEST MISSOURI. MOISTURE AXIS THIS MORNING WAS/IS LOCATED JUST WEST OF THE KANSAS MISSOURI STATE LINE. VERTICAL CU WAS EVIDENT ON VISIBLE SATELLITE IMAGERY AND WAS SLOWLY ADVECTING EAST UNDER THE INFLUENCE OF WEAK WESTERLIES AT 850MB. SURFACE BASED CAPE VALUES JUMP OVER 1500 J/KG THIS AFTERNOON IN EASTERN KANSAS THIS AFTERNOON ON THE RUC/GFS/NAM MODELS. WITH LITTLE TO NO CAP IN PLACE SOME SMALL ISOLATED STORMS HAVE ALREADY BEEN NOTED PERCOLATING ACROSS EAST KANSAS ALREADY THIS MORNING. RESTRICTED THE POPS TO EASTERN KANSAS AND NORTHWEST MISSOURI AS SURFACE HIGH CENTERED TO OUR EAST...AND WEAK WINDS ALOFT...WILL LIMIT THE ABILITY OF THE STORMS TO MOVE PAST MUCH THE STATE LINE. CUTTER && .PAST DISCUSSION... AREAS OF PATCHY FOG AND STRATUS DEVELOPING THIS MORNING ATOP SATURATED SOIL FROM YESTERDAYS RAIN. EXPECTING THIS TO BURN OFF AND BREAK UP DURING THE MORNING HOURS WITH CU DEVELOPING BY LATE MORNING/EARLY AFTERNOON...MORE SO ACROSS THE WESTERN CWA WHERE MORE ABUNDANT LOW LEVEL MOISTURE RESIDES. SYNOPTICALLY...AREA REMAINS TRAPPED BETWEEN STUBBORN UPPER RIDGE TO THE NW AND UPPER LOW TO THE EAST. WITH THE ABSENCE OF A DECENT SHORT WAVE TO SPARK CONVECTION...NOT OVERLY IMPRESSED WITH PRECIP CHCS TODAY. WILL LIKELY SEE MODEST INSTABILITY ACROSS THE WESTERN CWA WHERE HIGHER LLVL MOISTURE IS CONFINED. HOWEVER...WITH DECENT WARM NOSE NEAR H7 AND LACK OF SFC FOCUS FOR INITIATION...SHOULD SEE CONVECTION KEPT AT BAY THROUGH THE AFTERNOON. OTHERWISE...MAIN CONCERN TODAY WILL BE WITH AFTERNOON TEMPS. SHOULD SEE 16-18C H85 TEMPS ACROSS THE AREA WITH THE WARMER READINGS ACROSS NW MO AND HAVE THEREFORE TAILORED ACCORDINGLY. NEXT POTENTIAL FOR PRECIP WILL BE WEDNESDAY NIGHT AS MODELS HINT AT A WEAK IMPULSE ROUNDING THE UPPER RIDGE AND TRAVERSING THE AREA ON THE BACK SIDE OF GREAT LAKES UPPER LOW. MUCH DISCREPANCY WITH REGARDS TO HOW THIS WILL EVOLVE...AND LEANED TOWARD GFS ENSEMBLE OUTPUT KEEPING THINGS DRY FOR THE TIME BEING UNTIL BETTER CONTINUITY IS REALIZED. OTHERWISE...RAISED TEMPS A FEW DEGREES EACH DAY FOR THE NEXT FEW DAYS AS H85 TEMPS SLOWLY CLIMB. THE REMAINDER OF THE FORECAST LOOKS TO BE ON TRACK AND NO CHANGES MADE BEYOND DAY 3. DEROCHE && .AVIATION... AXIS OF BROKEN MVFR CEILINGS EXTENDING ACROSS THE TERMINALS WILL STEADILY DISSIPATE OVER THE NEXT COUPLE HOURS WITH THE LOSS OF DAYTIME HEATING. WAVERING MOISTURE GRADIENT HAS ONCE AGAIN EASED EAST OF THE TERMINALS...WITH DEWPOINTS NOW BACK TO AROUND 70F. SO DESPITE SE WINDS OVERNIGHT...CONTRIBUTION FROM RAINFALL THIS MORNING SHOULD ALLOW AT LEAST LIGHT FOG TO DEVELOP ACROSS THE TERMINALS BEFORE DAYBREAK. LOW LYING AREAS...ESPECIALLY AROUND KSTJ TERMINAL...SHOULD TOUCH IFR CONDITIONS. BOOKBINDER && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. $$ mo