AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 234 PM MDT FRI JUL 20 2007 .SHORT TERM... (TONIGHT AND SATURDAY) ...LOCALIZED FLASH FLOODING POSSIBLE AGAIN THIS AFTERNOON AND EVENING MAINLY WEST OF I-25... MOISTURE PLUME STILL OVER CENTRAL AND WESTERN CO WITH THE MAIN UPPER HIGH CENTER LOCATED OVER NE CO/SE WY. ONCE AGAIN...ITS DIFFICULT TO PICK OUT ANY EMBEDDED SHORTWAVES OVER THE REGION...THOUGH RUC IS PLACING A VORT MAX OVER WRN CO...WHICH IS DRIFTING SLOWLY TO THE NE. COULD BE AN WEAK MCV ASSOC WITH LAST NIGHTS CONVECTION ACROSS EASTERN CO WHICH IS DRIFTING TO THE WEST ALONG THE SRN PERIPHERY OF THE UPPER HIGH CENTER...BUT MODELS DON`T SEEM TO INDICATE THIS FEATURE...SO HARD TO KNOW HOW MUCH UPPER LIFT MAY BE PRESENT. SFC DEW POINTS QUITE HIGH ACROSS MUCH OF THE AREA...WITH MID 50S/LOWER 60S ACROSS THE PLAINS...AND UPPER 40S TO LOWER 50 DEWPOINTS ACROSS THE MTN LOCATIONS AS WELL. WITH MOISTURE PLUME TRANSLATING WESTWARD IN WV PICS...THINK MAIN THREAT FOR HEAVY RAINFALL WILL BE ACROSS THE WESTERN HALF OF THE FCST AREA. CLOUD COVER HAS SLOWED SFC BASED HEATING...WHICH HAS DELAYED THUNDERSTORM DEVELOPMENT ACROSS THIS AREA...HOWEVER LATEST RADAR TRENDS ARE SHOWING SOME THUNDERSTORMS POPPING ALONG THE CREST OF THE SRN SANGRES...AND ALONG THE EAST SLOPES OF THE LA GARITAS AND EASTERN SAN JUAN MTS. SO FOR TONIGHT...PRECIP WATERS/LAYER SPECIFIC HUMIDITIES REMAIN HIGH THROUGH THE EVENING...(150% OF NORMAL IN GJT 12Z MORNING SOUNDING). THUS...HEAVY RAIN POTENTIAL IS STILL THERE. WITH GROUND SATURATED IN SOME AREAS FROM YESTERDAY/S RAINFALL...SOME AREAS ARE ALREADY PRIMED FOR POTENTIAL FLASH FLOODING. HAVE OPTED TO ISSUE A FLASH FLOOD WATCH ONCE AGAIN...THOUGH THIS TIME THINK THREAT AREA WILL BE A BIT FARTHER WEST. MODEL QPFS ARE ALL OVER THE MAP WITH RUC ALREADY OVERDOING PCPN ACROSS THE EASTERN PLAINS DURING THE MORNING HOURS WHERE NO PRECIPITATION HAS BEEN OCCURRING. HOWEVER BY LATER THIS AFTN/EVENING...ENOUGH SFC BASED HEATING...AND WHATEVER WEAK UPPER LIFT IS AVAILABLE...SHOULD ALLOW SCATTERED TO NUMEROUS THUNDERSTORMS TO DEVELOP ALONG/WEST OF I-25. EAST OF I-25...ATMOS MAY BE MORE CAPED...AND FORCING DOESN/T LOOK AS GREAT IN THIS REGION...SO ISOLATED POPS SHOULD DO IT. CONCEPTUALLY...FOCUS FOR HEAVIEST PCPN SHOULD BE ACROSS FREMONT COUNTY...THE SANGRES AND WET MOUNTAINS...PIKES PEAK/TELLER COUNTY...CHAFFEE/LAKE COUNTIES...AND THE SOUTHWEST MTS INCLUDING THE LA GARITAS AND EASTERN SAN JUAN MTS EAST OF THE CONTDVD. THINK THREAT WILL BE LOCALIZED...BUT GIVEN THAT IMPACT COULD BE COMPOUNDED BY THE FACT THAT SOME AREAS ARE ALREADY SATURATED FROM YESTERDAY`S RAINFALL...WENT AHEAD AND ISSUED THE WATCH. HEAVY RAINFALL IS POSSIBLE JUST ABOUT ANYWHERE...BUT DECIDED TO LIMIT THE WATCH AREA TO LOCATIONS WHERE COMPLEX TERRAIN...BURN SCARS...OR SATURATED SOILS MAKE FLASH FLOODING PARTICULARLY SUSCEPTIBLE. OF COURSE EVEN IN URBAN AREAS...2 INCH PER HOUR RAINFALL RATES CAN QUICKLY OVERWHELM DRAINAGE SYSTEMS. THINK MAIN THREAT AREA WILL BE WEST OF INTERSTATE 25...BUT DID INCLUDE PUEBLO COUNTY SINCE WRN PORTIONS ARE SO SATURATED. TOUGH CALL FOR EL PASO COUNTY AS THIS AREA LOOKS TO BE JUST ON THE FRINGES OF THE THREAT AREA. FOR NOW WILL LEAVE THEM OUT OF THE WATCH SINCE THEY DIDN/T GET THE WIDESPREAD RAINFALL WHICH OCCURRED YESTERDAY...AND WILL MONITOR LATEST RADAR TRENDS AND MAKE THIS A LAST MINUTE CALL BEFORE ZONE ISSUANCE. THUNDERSTORMS SHOULD DIMINISH FOR MOST AREAS BY MIDNIGHT...THOUGH COULD STILL SEE SOME LINGERING SHOWERS AFTER MIDNIGHT ACROSS THE WRN MTS. AS FOR SEVERE WEATHER POTENTIAL...HIGHEST CAPES APPEAR TO BE ACROSS SRN AND WRN PORTIONS OF THE FCST AREA...WHERE LAPS INDICATES 1500-2000+ J/KG OF CAPE. FREEZING LEVELS ARE QUITE HIGH...SO SOME MARGINAL SEVERE HAIL IS POSSIBLE OVER THE MOUNTAIN AREAS...THOUGH THINK MOST OF THE HAIL WILL BE AROUND 1/2 INCH OR LESS IN DIAMETER. DEEP LAYER SHEARS STILL QUITE WEAK...SO NOT EXPECTING ANY ROTATING SUPERCELLS. FOR SATURDAY...DRIER AIR MOVES INTO THE EASTERN SECTIONS OF THE FCST AREA...AND LEE TROF EXPANDS SOUTHWARD WHICH HELPS TO DRY OUT SFC DEW POINTS ALONG AND EAST OF THE SE MTS. PRECIP WATERS STILL QUITE HIGH OUT WEST...SO IMAGINE THAT THERE WILL STILL BE SOME THREAT FOR FLASH FLOODING ACROSS THE SOUTHWEST/CEN MTNS...BUT THREAT MAY BE MORE LOCALIZED. TEMPS WARM A FEW DEGREES FOR EASTERN AREAS ON SATURDAY...AND OVERALL GRIDS LOOK IN GOOD SHAPE. MAIN CHANGE WAS TO BUMP UP POPS FOR THE WRN MTS SAT AFTN. -KT .LONG TERM... SATURDAY NIGHT THROUGH FRIDAY UPPER RIDGE REMAINS OVER THE REGION THROUGH THE FORECAST PERIOD. UPPER HIGH CENTER WOBBLES TO EAST OVER THE WEEKEND THEN REFORMS TO THE NORTH. THIS SHOULD ALLOW DRIER AIR TO WORK INTO EASTERN PORTIONS OF THE FORECAST AREA BUT MOISTURE REMAINS TRAPPED UNDER THE RIDGE ALONG AND WEST OF CONTINENTAL DIVIDE. THIS WILL KEEP THE DIURNAL CONVECTION GOING OVER THE HIGH TERRAIN. TEMPS WILL START TO WARM AGAIN RETURNING TO ABOVE NORMAL AT LEAST THROUGH MID WEEK. INTERESTING PATTERN CHANGE FOR THE END OF THE FORECAST CYCLE. EUROPEAN AND GFS MODELS INDICATING THAT THE UPPER LOW IN THE NORTHEAST WILL RETROGRADE WESTWARD. THIS SHOULD PUT THE EASTERN PLAINS OF THE FORECAST AREA INTO A COOLER PATTERN WITH NORTHERLY FLOW AROUND THE BACK SIDE OF THE UPPER LOW WHILE THE WEST REMAINS WARM AND MOIST WITH CONTINUED SOUTHERLY FLOW AND MOISTURE TRAPPED UNDER THE RIDGE. HELD ON TO CURRENT FORECAST WITHOUT MUCH CHANGE. WARMED MAX TEMPS SLIGHTLY ON WEDNESDAY AND THURSDAY. -FORTUNE- && .AVIATION... HEAVY RAIN WITH IFR CIGS EXPECTED WITH THUNDERSTORMS ALONG AND WEST OF THE INTERSTATE 25 CORRIDOR THROUGH THIS EVENING. THUNDERSTORMS SHOULD DISSIPATE AFTER 06Z WITH SOME LINGERING LIGHT SHOWERS ALONG THE SOUTHERN AND WESTERN PORTIONS OF THE ROUTES UNTIL 12Z. IFR TO MVFR CIGS MAY DEVELOP ACROSS THE SAN LUIS VALLEY OVERNIGHT...AFFECTING THE KALS TAF SITE. MORE PATCHY IFR TO MVFR CIGS WILL BE POSSIBLE ACROSS THE PLAINS TONIGHT AS WELL...HOWEVER WITH WESTERLY DRAINAGE WINDS OFF THE EASTERN MTS...THINK THESE CLOUDS WILL STAY EAST OF THE KCOS AND KPUB TAF SITES. THUNDERSTORMS WILL BE FOCUSED MORE TO THE WEST FOR SATURDAY...WHERE HEAVY RAIN AND LOCAL IFR CIGS WILL BE POSSIBLE MAINLY WEST OF KANK AND KALS. && .PUB WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 11 PM MDT THIS EVENING FOR COZ058>063- 065>068-072>083-086>088. && $$ 31/21 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 350 AM MDT FRI JUL 20 2007 .SHORT TERM... (TONIGHT AND FRIDAY) ...HEAVY RAIN AND FLOODING REMAIN A CONCERN THROUGH THIS EVENING... IMPRESSIVE MCC OVER CO EARLY THIS MORN...WHICH HAS DEVELOPED A LIFE OF ITS OWN IN THE CENTER OF A BROAD UPPER RIDGE THAT CONTINUES TO BUILD NORTHWARD THROUGH THE CENTRAL ROCKIES AND HIGH PLAINS. CLOUD TOPS HAVE STEADILY WARMED THIS MORN...EXCEPT OVER EXTREME SERN COUNTIES WHERE CONVECTION REMAINS PRETTY ACTIVE ATTM. A LINE SEGMENT OVER BACA COUNTY WILL MOVE SLOWLY TO THE NW THIS MORN...AND IS LIKELY PRODUCING SOME PRETTY HEAVY LOCAL RAINFALL AND SMALL HAIL. EVEN 06Z RUNS OF HIGHER RES NAM AND RUC HAVE NOT PICKED UP ON THE CONVECTION OVER THE SERN PLAINS...WHICH LEAVES LITTLE CONFIDENCE IN SPECIFIC QPF FORECASTS FOR TODAY. MAIN AREA OF CONCERN TODAY WILL BE OVER THE ERN MTS AND ADJACENT PLAINS...WHERE A BROAD AREA RECEIVED 2-4 INCHES OF RAIN YESTERDAY. WILL ALSO SEE POTENTIAL FOR FLASH FLOODING OVER THE ERN SAN JUANS...LA GARITAS...AND SRN SAWATCH LATER THIS AFTERNOON. THIS REGION DID NOT RECEIVE AS MUCH RAINFALL YESTERDAY...BUT AS HIGH SLOWLY SHIFTS TO THE N AND E TODAY...MAY SEE FOCUS FOR HEAVY CONVECTION SHIFT TO THE WRN RANGES. QPF FROM THE LATEST GUIDANCE IS NOT THAT HIGH FOR EITHER OF THESE REGIONS TODAY...IN THE .5 TO 1 INCH RANGE...BUT IT WILL NOT TAKE MUCH WITH ALREADY SATURATED SOILS FOR FLOODING TO OCCUR WITH ANY STORMS THAT DO DEVELOP. PRECIP H20 IS DOWN A BIT FROM YESTERDAY...BUT STILL IN THE 1.25-1.5 INCH RANGE. DEWPOINTS REMAIN QUITE HIGH...SATURATED RIGHT NOW AT KPUB WITH A DEWPT OF 63...AND UPPER 50S TO LOWER 60S OVER MUCH OF SWERN CO. EVEN HIGH VALLEYS ARE IN THE UPR 40S TO LOWER 50S. SO...A WHOLE LOT OF AVAILABLE MOISTURE TO WORK WITH TODAY. MAIN PROBLEM IS THAT...UNLIKE YESTERDAY...THERE IS NO REAL SYNOPTIC FEATURE TO SET OFF PRECIP. MAIN TRIGGER TODAY WILL PROBABLY CONTINUE TO BE THE WEAK CIRCULATION OVER CO THAT HAS BEEN SETTING OFF SHRA THROUGH THIS MORNING. TEMPS WILL BE A GOOD 10-12 DEGREES LOWER TODAY WITH MOISTURE AND HEAVY CLOUD COVER KEEPING THINGS ON THE COOL SIDE. WENT CLOSE TO THE NAM-BASED MOS FOR TEMPS TODAY. SO...WHILE THERE IS DEFINITELY POTENTIAL FOR MORE FLOODING TODAY...WILL HOLD OFF ON ANY WATCHES FOR NOW BUT STRONGLY HIGHLIGHT THE POTENTIAL IN THE HWO AND GRAPHICAL FORECASTS. LIKE YESTERDAY...WEAK UPPER WINDS WILL LIMIT STORM MOVEMENT AND THIS COULD BE PROBLEMATIC WITH ANY STRONG CONVECTION THAT DOES DEVELOP. SHOULD SEE CONVECTION WIND DOWN A BIT EARLIER THIS EVE...AS THE UPR HIGH CONTINUES TO BUILD...SETTING THE STAGE FOR A HOT AND RELATIVELY DRY WEEKEND. ROSE .LONG TERM... (SATURDAY THROUGH THURSDAY) MAIN ISSUES ARE THE USUAL...COVERAGE OF PRECIPITATION AND TEMPERATURES. SATURDAY...UPPER HIGH FIRMLY IN PLACE OVER COLORADO...BUT WITH MOISTURE IN THE RIDGE...WOULD EXPECT CONVECTION TO ERUPT AGAIN FROM THE I-25 CORRIDOR TO THE WESTERN AND CENTRAL MOUNTAINS. WOULD BET THE FOCUS OF THE HEAVIER RAINFALL WOULD BE ACROSS THE HIGHER TERRAIN...AS INDICATED BY THE HIGHER CAPES IN THE NAM12. NEED TO WATCH FOR REPEAT RAINFALL EVENTS...ESPECIALLY OVER THE EASTERN MOUNTAINS...FOR THE POSSIBILITY OF FLASH FLOODING. HAVE LOWERED HIGH TEMPERATURES...PER NEW GUIDANCE...AND THE FACT THAT THE GROUND IS WET ALONG THE I-25 CORRIDOR...AND OTHER AREAS IN THE MOUNTAINS AND SOUTHEAST. SUNDAY...THE UPPER FLOW IS WEAK...AT THE CENTER OF THE RIDGE...SO ANY DEEP CONVECTION WILL MOVE SLOWLY...AND LOCALLY HEAVY RAINS ARE AGAIN PROBABLE. FOCUS OF RAINFALL AGAIN WILL BE IN THE MOUNTAINS AND HIGH VALLEYS. COVERAGE OF RAIN ON NAM12 LESS...AND MID LEVEL TEMPERATURES A TAD HIGHER....SO KEPT GOING FORECAST OF THE WARMER WEEKEND DAY INTACT. GUIDANCE HAS DEEP EASTERLY FLOW ON MONDAY...SO PRECIPITATION SHOULD BE CONFINED TO THE I-25 CORRIDOR AND WESTWARD. TEMPERATURES SHOULD SOAR WELL INTO THE 90S ACROSS THE PLAINS...WITH 80S TO 60S IN THE HIGH VALLEYS AND MOUNTAINS. FOR THE REST OF THE FORECAST PERIOD...LITTLE CHANGE...WITH MID LEVELS TEMPERATURES HOVERING BETWEEN 14 AND 18 DEGREES CELSIUS...AND DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS FROM THE EASTERN MOUNTAINS TO THE SAWATCH RANGE AND EASTERN SAN JUANS...AS UPPER RIDGE MOVES LITTLE. && .AVIATION...MAIN CONCERN WILL BE LOW CIGS THIS MORNING OVER MUCH OF THE SERN PLAINS...AND POTENTIAL FOR WIDESPREAD HEAVY RAINFALL ONCE AGAIN THIS AFTERNOON AND EVENING. PATCHY FOG EARLY THIS MORN SHOULD BE LIMITED TO THE HYR TRRN AND WILL DISSIPATE LATER THIS MORN. CONCERN THIS AFTERNOON WILL SHIFT TO AREAS OF IFR VIS IN NUMEROUS THUNDERSTORMS THAT DEVELOP THIS AFTERNOON. BEST POTENTIAL FOR HEAVY RAINFALL AND SMALL HAIL WILL BE OVER THE MOUNTAINS AND ADJACENT PLAINS. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 44/13 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 324 AM MDT THU JUL 19 2007 .SHORT TERM... (TODAY AND TONIGHT) ...STRONG-SEVERE TSTMS POSSIBLE WITH HEAVY RAIN THIS AFTN/EVE... CURRENTLY...SATELLITE IMAGERY SHOWED MESOSCALE CONVECTIVE SYSTEM(MCS) STRETCHED ACROSS MUCH OF NE...NRN KS...AND IA EARLY THIS MORNING. RESULTANT OUTFLOW BOUNDARY WAS RACING THROUGH SERN CO/SWRN KS PER REGIONAL RADAR DATA. MUCH OF THE MCS PRECIPITATION OVER NWRN KS WAS DISSIPATING. FURTHER W...ISOLD-SCT SHRA AND A FEW TSTMS WERE OVER EXTREME WRN CO/ERN UT. 08Z/19 HAND ANALYZED SURFACE CHART SHOWED LOWER TO MIDDLE 60S DEW POINTS ACROSS NERN CO AND TRYING TO ADVECT INTO SERN CO PLAINS. MSAS SURFACE PRESSURE CHANGE ANALYSIS HAD THE STRONGEST RISES FURTHER NE INTO SRN NE DIRECTLY UNDER THE MCS CENTROID(MBE). MIDDLE AND UPPER LEVEL HIGH PRESSURE CENTER WAS OVER CNTRL CO PER RUC MODEL UPPER AIR ANALYSES. TODAY...BIG FORECAST CHALLENGES WITH TSTM DEVELOPMENT AND ITS IMPACT WEATHER. ACTUAL PLACEMENT OF THE SURFACE-LOW LEVEL FRONTAL BOUNDARY ACROSS SERN CO PLAINS WILL BE A KEY. HIGH RESOLUTION MODEL WANTS TO STALL IT OUT SOMEWHERE AROUND THE CO/NM/OK/KS BORDER LATER TODAY...WHICH COULD BE REASONABLE GIVEN THE LACK OF CURRENT PRESSURE RISES BEHIND THIS PART OF THE BOUNDARY. ACTUAL LOW LEVEL MOISTURE WILL BE ANOTHER KEY. RUC40 AND WRF WANT TO BRING 60S SURFACE DEW POINTS UP AGAINST THE MOUNTAINS AND SERN CO PLAINS LATER TODAY. RESULTING IN SOME RELATIVELY HIGH SURFACE-BASED CAPE VALUES UP TO 3K J/KG ACROSS SERN CO. IF THE SURFACE DEW POINTS ARE LOWER...THEN CAPE VALUES WILL BE A LITTLE LOWER...BUT STILL RESPECTABLE PROBABLY AROUND 1K-2K J/KG WITH LIFTED INDICES OF 0C TO -4C. NOTHING IN THE MIDDLE/UPPER LEVELS TO FOCUS ON A TSTM TRIGGER TODAY TO ENHANCE CONVECTION...SO WILL NEED TO RELY ON LOW LEVEL FORCING. NO H3-H2 POTENTIAL VORTICITY LOBE WITHIN THE WEAK FLOW HIGH ALOFT...WHICH IS USUALLY TO BE EXPECTED. THINK THE 12Z-15Z RUC40 QPF IS A LITTLE OVERDONE. THINKING IS THE SAME THING WILL HAPPEN HAS YESTERDAY. ISOLD-SCT SHRA/TSRA WILL FIRE UP OVER THE MOUNTAINS BETWEEN 15Z-18Z AND THEN SPREAD INTO THE ADJACENT VALLEYS AND I-25 CORRIDOR DURING THE AFTN. POTENTIAL FOR SOME LOW LEVEL BOUNDARY FORCING NEAR AND JUST N OF THE BOUNDARY ACROSS THE SERN CO PLAINS THIS AFTN. THE MAIN TSTM IMPACT WEATHER SHOULD BE MODERATE-HEAVY RAIN GIVEN THE RELATIVELY WEAK CLOUD LAYER STEERING CURRENTS OF 5KTS OR LESS...RELATIVELY HIGH FREEZING LEVELS...AND H7-H5 SPECIFIC HUMIDITY VALUES OF 6-8 G/KG. LOCALIZED 1 TO 2 INCHES PER HOURS WOULD BE POSSIBLE THIS AFTN...ESPECIALLY GIVEN TSTM CELL TRAINING AND MERGERS. JUST MODERATE RAIN IN EXTREMELY DIVERSE COMPLEX TERRAIN(E.G. CANYONS) COULD CAUSE A VERY LOCALIZED FLASH FLOOD THREAT. PRIMARILY...THE STORM TYPE SHOULD BE PULSE...BUT WITH 0-6KM SHEAR VALUES AROUND 20-25KTS JUXTAPOSED WITH A LOW LEVEL BOUNDARY...MIGHT SUGGEST THE POTENTIAL FOR A ROTATING STORM SOMEWHERE IN SERN CO PLAINS. PATTERN WOULD SUGGEST THE POTENTIAL FOR PROLIFIC SMALL HAILERS PRODUCING COUPLE OF INCHES WITH THE SLOW MOVING STORMS...ESPECIALLY FOR THE HIGHER ELEVATIONS WHERE THE SMALLER HAILSTONES WOULD HAVE A GREATER PROBABILITY OF SURVIVING. STILL COULD NOT RULE OUT ONE OR TWO FREAK SEVERE TSTMS THIS AFTN. BASED ON POST RADAR ANALYSIS FROM YESTERDAY...WILL INCREASE POPS TO LIKELY OVER THE MOUNTAINS AND HIGH SCATTERED POPS FOR THE LOWER ELEVATIONS. ALSO...ADDED MODERATE-HEAVY RAIN TO MUCH OF THE CWFA WITH THE HEAVY RAIN THREAT FOR OUR SERN CO MOUNTAINS/PLAINS. CURRENT HIGH TEMPERATURES LOOK REASONABLE AND THE MET MOS GUIDANCE MIGHT BE A LITTLE TOO COOL AND THE MAV MOS GUIDANCE A LITTLE TOO WARM. TONIGHT...THE EVE TSTM ACTIVITY WILL DEPEND ON WHEN AND WHERE THINGS GET GOING THIS AFTN AND HOW /WORKED OVER/ THE ATMOSPHERE IS BY THIS EVE. THE TSTM FOCUS...WITH HEAVY RAIN...MAY SHIFT TOWARDS THE NM/CO/OK/KS BORDER DURING THE EVE AND SHUTDOWN QUICKLY FURTHER N. TOUGH CALL. MUCH OF THE TSTM ACTIVITY SHOULD DISSIPATE AROUND MIDNIGHT GIVEN THE LACK OF ANY SYNOPTIC SCALE FORCING OVERNIGHT. METZE .LONG TERM... (FRIDAY THROUGH WEDNESDAY) ...MORE HEAT FOR THE WEEKEND... THE MAIN FEATURE FOR THE EXTENDED CONTINUES TO BE THE PERSISTENT UPPER RIDGE OVER THE CENTRAL AND SOUTHERN ROCKIES. THE HIGH CENTER WILL SLOWLY MOVE TO THE NORTHEAST...OVER CO BY THIS WEEKEND AND THEN INTO THE NORTHERN HIGH PLAINS AND UPP MISSOURI BY NEXT WEEK. THIS WILL CONTINUE THE WARM WX AND DIURNAL TSTORMS OVER THE MTS THROUGH THE EXTENDED. ONLY REAL CHANGE IN THE FORECAST WAS TO FOCUS POPS OVER THE CONTDVD ESPECIALLY AS THE HIGH MOVES NORTH OF CO. H5 WINDS WILL THEN BE ERLY...AND THIS WILL KEEP DIURNAL TSTORMS FROM MOVING OUT OVER THE ERN PLAINS. SHOULD SEE ONE MORE RELATIVELY COOL DAY ON FRI AS ERLY PUSH CONTINUES OVR THE PLAINS. MAY SEE SOME LOW CLOUDS OVER THE SERN GRASSLAND FRI MORN AND AGAIN EARLY SAT WITH LIGHT ERLY FLOW CONTINUING AT THE SURFACE AND ABUNDANT LLVL MOISTURE. H7 TEMPS REBOUND NICELY BACK TO 18 DEG C OR SO FOR SAT AND SUN...AND THESE SHOULD BE THE WARMEST DAYS WITH TEMPS OVR THE PLAINS ONCE AGAIN CLOSE TO 100 DEG. UPPER RIDGE WILL SLOWLY WEAKEN AND BECOME MORE `DIRTY` NEXT WEEK...WITH LONG RANGE MODELS INDICATING A POSSIBLE PATTERN CHANGE BY THE END OF THE MONTH. ROSE && .AVIATION... SHRA/TSRA WILL AFFECT MUCH OF THE AIRPORTS AND FLIGHT ROUTES BETWEEN 17Z/19 - 04Z/20. SHRA/TSRA WILL CREATE ERRATIC WINDS ALONG WITH MVFR-VFR MODERATE TO HEAVY RAIN AND SMALL HAIL. METZE && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 17/44 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBANY NY 1011 PM EDT THU JUL 19 2007 .SYNOPSIS... A SURFACE LOW WAS LOCATED NEAR GLENS FALLS THIS EVENING. A WARM FRONT EXTENDED FROM THIS LOW ACROSS MASSACHUSETTS TO NEAR CAPE COD. A STRONG COLD FRONT WAS POISED TO ENTER WESTERN NEW YORK STATE. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... NEXT SLUG OF RAINFALL ABOUT TO ENTER CWA THIS EVENING. HIT OR MISS LIGHTNING ASSOCIATED WITH THIS PRECIP WAS NOTED ACROSS THE SOUTHERN TIER. PRECIP WILL CONTINUE TO MARCH EASTWARD TONIGHT AND OVERSPREAD ENTIRE CWA. WILL CARRY CATEGORICAL PRECIP WITH CHANCE TSRA. EVENING ALY SOUNDING SHOWED SURPRISING CAPE AT 1700 J/KG. HOWEVER PLUGGING IN CURRENT SURFACE READINGS CAPE DOWN TO 600 J/KG AND CIN ON THE RISE. RUC FORECAST SHOWS SHOWALTERS TO LINGER AROUND 0C THROUGH THE NIGHT...SO MAINTAINING CHANCE TSRA SEEMS WARRANTED. SEVERE CHANCE IS NIL. UPPED MIN TEMPS SLIGHTLY GIVEN CURRENT READINGS AND ALSO TWEAKED WINDS TO MAINTAIN MORE NORTHERNLY WINDS ACROSS NORTHERN HALF OF THE CWA. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... NCEP AND THE NAM-12 MODEL MOVE THE FRONT ACROSS THE FORECAST AREA THIS EVENING WITH SOME RAIN PERSISTING OVER OUR WESTERN NEW ENGLAND ZONES OVERNIGHT. IN THE MEANTIME A SECOND AREA OF RAIN ASSOCIATED WITH THE UPPER TROF BEGINS TO DROP SOUTHEAST OUT OF CANADA INTO NORTHERN AND WESTERN NEW YORK BY MID MORNING. THE SURFACE LOW LIFTS NORTHEAST INTO THE MARITIMES LATE FRIDAY AFTERNOON AND ENABLES HIGH PRESSURE TO MAKE ITS WAY INTO THE REGION FRIDAY NIGHT. MEANWHILE THE 500 HPA TROF SHARPENS AND DIGS SOUTH ALONG THE EAST COAST ON SATURDAY... AS THE RIDGE TO THE WEST SLOWLY MAKES IT WAY INTO THE PLAINS. A SURFACE LOW FORMS NEAR CAPE HATTERAS FRIDAY EVENING AND MOVES NORTH TO OFF THE DELMARVA COAST BY NOON SATURDAY. AT THIS TIME IT APPEARS ITS EFFECT WILL BE LIMITED TO SPREADING SOME HIGH CLOUDS OVER OUR NEW ENGLAND ZONES. && .LONG TERM /SUNDAY THROUGH THURSDAY/... THE 500 HPA TROF OVER THE REGION CONTINUES TO DIG SOUTH ALONG THE EAST COAST SUNDAY...AS THE RIDGE TO THE WEST MIGRATES FROM THE PLAINS TO THE UPPER MISSISSIPPI VALLEY. A SURFACE HIGH OVER THE WESTERN GREAT LAKES BUILDS SOUTH AND SLIGHTLY EAST THE LOW EAST DELMARVA DRIFTS SLOWLY EAST INTO THE ATLANTIC. A CUTOFF LOW FORMS IN THE TROF OVER SOUTHERN NJ AND THE TROF STALLS OVER THE HUDSON VALLEY...AS THE SURFACE LOW MOVES TO EAST OF CAPE COD AND THE HIGH DRIFTS SLOWLY EAST. ON MONDAY THE CUTOFF LOW BEGINS TO LIFT OUT TO THE NORTH AS THE RIDGE TO THE WEST CONTINUES TO MOVE SLOWLY EAST. A COLD FRONT DROPS SOUTH OUT OF CENTRAL CANADA AND WEAKENS AND DISSIPATES AS IT STALLS CLOSE TO THE REGION MONDAY NIGHT AND TUESDAY. MEANWHILE THE LARGE 500 HPA HIGH TO THE WEST BEGINS TO MOVE INTO THE REGION...SETTING UP WHAT APPEARS TO BE A CLASSIC BERMUDA HIGH BY WEDNESDAY AFTERNOON. IT LOOKS LIKE THE BERMUDA HIGH WILL DOMINATE OUR WEATHER THROUGH THURSDAY...RESULTING IN SULTRY WEATHER WITH HIGHS IN THE 80S TO NEAR 90...DEWPOINTS IN THE MID 60S...AND AFTERNOON SHOWERS AND THUNDERSTORMS. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... NEXT ROUND OF SHRA TRACKING ACROSS CENTRAL NOW AND EXPECT TO ARRIVE AT AREA TERMINALS BY ABOUT 02Z. SHOULD SEE MAINLY MVFR CONDITIONS WITH THIS ACTIVITY...BASED ON UPSTREAM OBS. BY THE TIME SHRA ACTIVITY ARRIVES...LITTLE IF ANY SURFACE BASED INSTABILITY AVAILABLE...BUT GIVEN POTENT NATURE OF SHORT WAVE...CAN NOT RULE OUT A RUMBLE OF THUNDER HENCE CB IN TEMPO GROUP. TIMING OF THIS PRECIP GETS IT OUT OF THE AREA BY ABOUT 07Z /ALTHOUGH NOT A LOT OF CONFIDENCE IN IT ENDING BY THEN/. ASSUMING TIMING IS CORRECT...HAVE ALLOWED FOR SOME CLEARING TO SET IN WITH ENOUGH TIME TO STILL LEAD TO BR FORMATION. THINKING NOW IS THAT WILL BE LIMITED TO IFR BR AND NOT FG...BUT IF CLEARING SETS IN IN EARNEST...THEN GFL COULD GO TO FG. FOR TOMORROW HAVE INCLUDED VCSH IN TAFS AS ANOMALOUSLY STRONG TROUGH LINGERS OVER THE AREA. FRI...MAINLY VFR...BUT MVFR POSSIBLE WITH A ISOLAD SHRAS. SAT...VFR...NO SIG WX. SUN...VFR...NO SIG WX. MON...VFR/MVFR...WDLY SCT SHRAS. && .HYDROLOGY... SOME MINOR RISES HAVE OCCURRED IN RIVERS AND STREAMS FROM THE RAIN WHICH FELL YESTERDAY. MOST OF THAT RAIN WENT INTO THE GROUND SO THE GROUND IS NOW MOISTER AND MORE OF WHAT RAIN COMES TODAY WILL RUN OFF. RAINFALL OVER THE AREA WILL GENERALLY AVERAGE AROUND AN INCH...BUT AMOUNTS WILL VARY A GREAT DEAL. SHARP RISES WILL OCCUR ON STREAMS IN THE VICINITY OF HEAVY DOWNPOURS BUT BASIN WIDE RAINFALL WILL ONLY BE ENOUGH TO CAUSE MINOR TO MODERATE WITHIN- BANK RISES. REFER TO OUR ADVANCED HYDROLOGIC PREDICTION PAGES FOR DETAILS ON SPECIFIC RIVERS. NUISANCE TYPE FLOODING OF POORLY DRAINED ROADS AND PARKING AREAS IS LIKELY TO OCCUR DURING HEAVY DOWNPOURS. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...OKEEFE NEAR TERM...OKEEFE ct AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 230 AM EDT THU JUL 19 2007 ...ABOVE AVERAGE TEMPERATURES CONTINUE TODAY... .SHORT TERM...GIVEN THE FACT THAT MOST OF THE CONVECTIVE ACTIVITY WAS SUPPRESSED YESTERDAY DESPITE IMPRESSIVE CAPE VALUES...A LITTLE SURPRISED TO SEE ACTIVITY FIRE AT THIS HOUR. BUT SUCH IS THE CASE OVER ST JOHNS COUNTY AND NOW OVER THE NEARSHORE ATLANTIC WATERS WITH EVEN A FEW LIGHTNING STRIKES EARLIER. EXPECT THIS SHOULD BE THE EXCEPTION MORE THAN THE RULE FOR THE REMAINDER OF THE OVERNIGHT HOURS WITH RUC SHOWING LARGE UPPER LEVEL RIDGE ACROSS ALL OF SOUTHEAST GEORGIA AND NORTHEAST FLORIDA. AT THE SURFACE...A TROUGH OF LOW PRESSURE IS MOVING THROUGH THE CAROLINAS AND NORTH GA AND HAS SHUNTED RIDGE AXIS TO THE SOUTH ONCE AGAIN OVER SOUTH CENTRAL FLORIDA. FOR TODAY...EXPECT A SIMILAR DAY TO YESTERDAY WITH UPPER HIGH BEING VERY INFLUENTIAL IN SUPPRESSING ACTIVITY. MODELS IN AGREEMENT WITH A DRY SLOT AT 700 MB INHIBITING CONVECTIVE DEVELOPMENT OVER NORTHERN FLORIDA ALONG THE I-10 CORRIDOR FOR MUCH OF THE DAY. LOW END SCT POPS WILL BE FAVORED SOUTH OF THIS FEATURE OVER ALACHUA AND MARION COUNTIES. FURTHER NORTH...OVER THE GA PORTION...ANOTHER SURFACE TROUGH WILL MOVE INTO THE REGION...THIS TIME AT THE TIME OF MAX HEATING. THIS SHOULD LEAD TO MORE STORM COVERAGE THAN PREVIOUS DAYS AND WILL INCLUDE LOW END SCT FOR MOST LOCATIONS. WITH WESTERLY STEERING FLOW AND THE ARRIVAL OF SURFACE TROUGH AND A SHORTWAVE THROUGH 06Z...LOOKS LIKE ACTIVITY MAY FIRE DURING THE LATE EVENING HOURS AS WELL ALONG COASTAL SOUTHEAST GA AND WILL KEEP POPS GOING INTO THE OVERNIGHT PERIOD. COMPLEX THAT IS GENERATED BY THE VORT LOBE WILL SHIFT OFFSHORE FOR FRIDAY WITH DRIER AIR MOVING IN ON THE BACK SIDE. THIS WILL ALLOW FOR A POP REDUCTION OVER THE GA PORTION FOR THE FIRST PART OF FRIDAY...WITH GREATEST RAIN CHANCES FOCUSED OVER NORTHEAST FLORIDA. HOWEVER...WITH SURFACE LOW DEVELOPMENT OVER THE CAROLINAS...AND ANOTHER SHORTWAVE...SE GA SHOULD GET IN ON THE ACT ONCE AGAIN DURING THE LATE EVEN HOURS WITH SCT POPS WARRANTED THROUGH THE OVERNIGHT PORTION. PRETTY TOUGH AT THIS POINT TO DETERMINE WHERE SURFACE TROUGH WILL RESIDE FOR SAT AND AT THIS POINT WILL GO WITH MID RANGE SCT POPS FOR ALL ZONES. WILL SLIGHTLY FAVOR THE SOUTHERN TIER AS PREVIOUS DAYS OUTFLOWS WILL LIKELY TAKE TROUGH FURTHER SOUTH THAN WHAT MODELS CURRENTLY DEPICT. .LONG TERM...NOT MUCH CHANGE TO THE LONG TERM AS SURFACE TROUGH STALLS OVER THE FLORIDA PORTION INITIALLY AND THEN SURGES BACK NORTHWARD WITH THE ESTABLISHMENT OF THE BERMUDA HIGH. HIGH END SCT POPS FOR THE FLORIDA PORTION SUNDAY AND MONDAY...WITH EVERYONE GETTING IN ON ACT BY MID WEEK. && .AVIATION...MOSTLY VFR CONDITIONS OUTSIDE OF ISOLD TSTMS. && .MARINE...LITTLE CHANGE TO PREVIOUS PACKAGE. GENERALLY SOUTHWEST WINDS BECOMING MORE S IN THE AFTN. NIGHTTIME WIND SURGES WILL CONTINUE...CAPPED AT 15 KTS. WINDS WILL BECOME MORE ONSHORE BY EARLY NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... AMG 97 72 97 71 / 30 30 30 30 SSI 92 78 92 76 / 30 40 30 20 JAX 97 74 97 74 / 30 40 30 20 SGJ 94 75 93 75 / 30 30 40 20 GNV 96 72 96 72 / 20 20 30 30 OCF 95 72 94 73 / 20 10 30 30 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ DEESE/CARROLL fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 1038 AM CDT FRI JUL 20 2007 .DISCUSSION... ISSUED 1031 AM CDT FRI JUL 20 2007 HIGH PRESSURE IS BUILDING SOUTHWARD ACROSS THE REGION THIS MORNING. A WEAK UPPER LEVEL DISTURBANCE IS MOVING THROUGH THE REGION AT THE MOMENT... WHICH HAS HELPED TO ENHANCE CU DEVELOPMENT ACROSS NORTHERN AREAS OF THE CWA... AS WELL AS SOME CIRRUS WHICH IS PUSHING SOUTH OF THE REGION. WILL ADJUST WIND SPEED/GUSTS UPWARD A BIT AS GRADIENT REMAINS STRONG ENOUGH TO 10-15 MPH THIS AFTERNOON... POSSIBLY SOME GUSTS UP TO 20 MPH. TEMPERATURES SHOULD TOP OUT NO HIGHER THAN 80 DEGREES ACROSS MUCH OF THE AREA... AND 80S WILL MOST LIKELY BE SUPPRESSED SOUTH OF A PRINCEVILLE-MATTOON-SHELBYVILLE LINE. WILL SEND OUT ZFP UPDATE BY 11 AM... BUT ONLY IF SIGNIFICANT WORDING CHANGES ARE PRODUCED. HARDIMAN && .AVIATION... ISSUED 632 AM CDT FRI JUL 20 2007...FOR THE 12Z TAFS CANADIAN HIGH PRESSURE IS BUILDING SOUTH INTO ILLINOIS THIS MORNING. SOME SCATTERED STRATOCU CLOUDS HAVE DEVELOPED ALONG A NARROW AXIS OF CHANNELED H5 VORTICITY IN EASTERN IOWA AND NORTHERN ILLINOIS. FORECAST SOUNDINGS INDICATE A THIN LATER OF MOISTURE WILL REMAIN ACROSS OUR AREA TODAY. CU RULE FROM NAM/GFS/ AND RUC ALL INDICATING THAT THE HEAT OF THE DAY WILL DEVELOP THAT MOISTURE INTO A SCATTERED CU FIELD. EVEN IF A DECK DEVELOPS...IT WILL BE FOR A VERY SHORT TIME...AS THE CU FLATTENS AND DISSIPATES IN THE DRY AIR ABOVE AND BELOW THE 4K FT LAYER. OTHERWISE...LIGHT NORTHEAST WINDS WILL PREVAIL TODAY...WITH CLEAR SKIES TONIGHT. NO FOG IS EXPECTED TO CAUSE ANY TRAVEL PROBLEMS...AS DEWPOINTS DROP INTO THE MID 50S. SHIMON && .PREV DISCUSSION... ISSUED 222 AM CDT FRI JUL 20 2007 TRANQUIL CONDITIONS TO PREVAIL ACROSS CENTRAL ILLINOIS FOR THE NEXT SEVERAL DAYS...AS HIGH PRESSURE DOMINATES THE WEATHER. 06Z SURFACE CHART SHOWS COLD FRONT AND ASSOCIATED CONVECTION SINKING SOUTH OF THE OHIO RIVER...AS COOLER AND DRIER AIRMASS SETTLES SOUTHWARD OUT OF CANADA. ALOFT...HIGHLY AMPLIFIED PATTERN CONTINUES ACROSS THE CONUS...WITH STRONG RIDGING OVER THE ROCKIES/PLAINS AND DEEP TROUGHING ACROSS THE EAST. SHORT TERM...TODAY THROUGH SUNDAY HIGH PRESSURE CURRENTLY CENTERED OVER THE UPPER MIDWEST WILL DROP SOUTHWARD TODAY...PROVIDING PLENTY OF SUNSHINE AND LIGHT NORTHEASTERLY WINDS. MUCH COOLER WEATHER WILL BE ON TAP...AS 850MB TEMPS ARE PROGGED TO DROP INTO THE 10 TO 12C RANGE. MET NUMBERS IN THE MIDDLE 70S SEEM A LITTLE TOO COOL FOR HIGHS...ESPECIALLY GIVEN THE DRY AIRMASS AND AMPLE SUNSHINE. WILL THEREFORE GO A COUPLE OF DEGREES HIGHER...WITH MOST LOCATIONS TOPPING OUT IN THE UPPER 70S TO AROUND 80 DEGREES. EXPECT LOW HUMIDITY AS WELL...WITH DEWPOINTS ONLY IN THE 50S...AND PERHAPS AS LOW AS THE UPPER 40S GIVEN AFTERNOON MIXING. CLEAR SKIES AND LIGHT WINDS WILL ALLOW FOR EXCELLENT RADIATIONAL COOLING TONIGHT...SUPPORTING LOWS MAINLY IN THE MIDDLE 50S. A FEW LOW-LYING RURAL LOCATIONS MAY EVEN DIP INTO THE LOWER 50S. PRETTY MUCH THE SAME WEATHER ON TAP FOR SATURDAY AND SUNDAY...WITH TEMPS SLOWLY INCHING UPWARD EACH DAY. SURFACE RIDGE AXIS REMAINS FIRMLY IN PLACE ACROSS THE REGION...SO SUNSHINE AND LIGHT E/NE WINDS WILL BE THE RULE. AFTERNOON HIGHS WILL CLIMB TO AROUND 80 DEGREES...WHILE OVERNIGHT LOWS DROP INTO THE 50S. LONG TERM...MONDAY THROUGH THURSDAY QUIET WEATHER WILL CONTINUE THROUGH THE MIDDLE OF NEXT WEEK...AS UPPER RIDGE ACROSS THE PLAINS STRENGTHENS AND BUILDS NORTHEASTWARD INTO THE GREAT LAKES. MODELS HAVE BEEN HINTING THAT HIGH AMPLITUDE RIDGE WILL ACT TO CUT OFF A PIECE OF ENERGY ACROSS THE MID-ATLANTIC STATES EARLY NEXT WEEK...WITH THIS FEATURE THEN POSSIBLY WOBBLING WESTWARD TOWARD ILLINOIS. BOTH ECMWF AND GFS HAVE BEEN FLIP-FLOPPING BACK AND FORTH CONCERNING THE EXACT POSITIONING OF THIS SYSTEM...SO FOR NOW WILL NOT BUY INTO ANY RETROGRESSION OF THE UPPER ENERGY. WILL THEREFORE KEEP EXTENDED DRY...WITH TEMPS RISING BACK TO AOA 90 DEGREES BY TUESDAY. BARNES && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 632 AM CDT FRI JUL 20 2007 .DISCUSSION... ISSUED 222 AM CDT FRI JUL 20 2007 TRANQUIL CONDITIONS TO PREVAIL ACROSS CENTRAL ILLINOIS FOR THE NEXT SEVERAL DAYS...AS HIGH PRESSURE DOMINATES THE WEATHER. 06Z SURFACE CHART SHOWS COLD FRONT AND ASSOCIATED CONVECTION SINKING SOUTH OF THE OHIO RIVER...AS COOLER AND DRIER AIRMASS SETTLES SOUTHWARD OUT OF CANADA. ALOFT...HIGHLY AMPLIFIED PATTERN CONTINUES ACROSS THE CONUS...WITH STRONG RIDGING OVER THE ROCKIES/PLAINS AND DEEP TROUGHING ACROSS THE EAST. SHORT TERM...TODAY THROUGH SUNDAY HIGH PRESSURE CURRENTLY CENTERED OVER THE UPPER MIDWEST WILL DROP SOUTHWARD TODAY...PROVIDING PLENTY OF SUNSHINE AND LIGHT NORTHEASTERLY WINDS. MUCH COOLER WEATHER WILL BE ON TAP...AS 850MB TEMPS ARE PROGGED TO DROP INTO THE 10 TO 12C RANGE. MET NUMBERS IN THE MIDDLE 70S SEEM A LITTLE TOO COOL FOR HIGHS...ESPECIALLY GIVEN THE DRY AIRMASS AND AMPLE SUNSHINE. WILL THEREFORE GO A COUPLE OF DEGREES HIGHER...WITH MOST LOCATIONS TOPPING OUT IN THE UPPER 70S TO AROUND 80 DEGREES. EXPECT LOW HUMIDITY AS WELL...WITH DEWPOINTS ONLY IN THE 50S...AND PERHAPS AS LOW AS THE UPPER 40S GIVEN AFTERNOON MIXING. CLEAR SKIES AND LIGHT WINDS WILL ALLOW FOR EXCELLENT RADIATIONAL COOLING TONIGHT...SUPPORTING LOWS MAINLY IN THE MIDDLE 50S. A FEW LOW-LYING RURAL LOCATIONS MAY EVEN DIP INTO THE LOWER 50S. PRETTY MUCH THE SAME WEATHER ON TAP FOR SATURDAY AND SUNDAY...WITH TEMPS SLOWLY INCHING UPWARD EACH DAY. SURFACE RIDGE AXIS REMAINS FIRMLY IN PLACE ACROSS THE REGION...SO SUNSHINE AND LIGHT E/NE WINDS WILL BE THE RULE. AFTERNOON HIGHS WILL CLIMB TO AROUND 80 DEGREES...WHILE OVERNIGHT LOWS DROP INTO THE 50S. LONG TERM...MONDAY THROUGH THURSDAY QUIET WEATHER WILL CONTINUE THROUGH THE MIDDLE OF NEXT WEEK...AS UPPER RIDGE ACROSS THE PLAINS STRENGTHENS AND BUILDS NORTHEASTWARD INTO THE GREAT LAKES. MODELS HAVE BEEN HINTING THAT HIGH AMPLITUDE RIDGE WILL ACT TO CUT OFF A PIECE OF ENERGY ACROSS THE MID-ATLANTIC STATES EARLY NEXT WEEK...WITH THIS FEATURE THEN POSSIBLY WOBBLING WESTWARD TOWARD ILLINOIS. BOTH ECMWF AND GFS HAVE BEEN FLIP-FLOPPING BACK AND FORTH CONCERNING THE EXACT POSITIONING OF THIS SYSTEM...SO FOR NOW WILL NOT BUY INTO ANY RETROGRESSION OF THE UPPER ENERGY. WILL THEREFORE KEEP EXTENDED DRY...WITH TEMPS RISING BACK TO AOA 90 DEGREES BY TUESDAY. BARNES && .AVIATION... ISSUED 632 AM CDT FRI JUL 20 2007...FOR THE 12Z TAFS CANADIAN HIGH PRESSURE IS BUILDING SOUTH INTO ILLINOIS THIS MORNING. SOME SCATTERED STRATOCU CLOUDS HAVE DEVELOPED ALONG A NARROW AXIS OF CHANNELED H5 VORTICITY IN EASTERN IOWA AND NORTHERN ILLINOIS. FORECAST SOUNDINGS INDICATE A THIN LATER OF MOISTURE WILL REMAIN ACROSS OUR AREA TODAY. CU RULE FROM NAM/GFS/ AND RUC ALL INDICATING THAT THE HEAT OF THE DAY WILL DEVELOP THAT MOISTURE INTO A SCATTERED CU FIELD. EVEN IF A DECK DEVELOPS...IT WILL BE FOR A VERY SHORT TIME...AS THE CU FLATTENS AND DISSIPATES IN THE DRY AIR ABOVE AND BELOW THE 4K FT LAYER. OTHERWISE...LIGHT NORTHEAST WINDS WILL PREVAIL TODAY...WITH CLEAR SKIES TONIGHT. NO FOG IS EXPECTED TO CAUSE ANY TRAVEL PROBLEMS...AS DEWPOINTS DROP INTO THE MID 50S. SHIMON && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 1250 PM CDT THU JUL 19 2007 .DISCUSSION... ISSUED 1032 AM CDT THU JUL 19 2007 STALLED FRONTAL BOUNDARY NOT QUITE STATIONARY...BUT DRIFTING VERY SLOWLY SOUTHWARD...OVER NRN ILLINOIS THIS MORNING...WELL BEHIND SCATTERED SHOWER ACTIVITY LEFT OVER FROM THE MCS THAT ROLLED ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST. SHOWER ACTIVITY TO GET REINFORCED LATER THIS AFTERNOON AND THIS EVENING FOR SRN TWO- THIRDS OF CWA. AS RESULT...HAVE LEFT MUCH OF FORECAST ALONE...ONLY TWEAKING THE TEMPERATURES SLIGHTLY. NO MAJOR UPDATES NECESSARY AT THIS POINT. && .AVIATION... ISSUED 1244 PM CDT THU JUL 19 2007 NORTHERN TAF SITES TO KEEP MOSTLY VFR THROUGH TONIGHT...WITH THE MAJORITY OF THE CONVECTIVE ACTIVITY SHIFTING SWD. BMI AND CMI STILL FIGHTING WITH REMNANTS OF VCSH. CMI...AND MORE LIKELY SPI AND DEC... MOST LIKELY TO SEE SOME THUNDER ACTIVITY THIS AFTERNOON AS MCV TO THE WEST MAKES ITS WAY THROUGH THE REGION. IN THE WAKE OF ALL THIS...DRIER AND COOLER AIR IS BEING USHERED BACK INTO THE REGION. HOWEVER...THE NORTHERN TAF SITES HAVE THE BEST CHANCE OF MIXING OUT SOME MOISTURE... BUT WILL ALSO BE THE FIRST TO CLEAR OUT TONIGHT. CHANCES OF FOG ARE GOOD...BUT ONLY WENT DOWN TO 1SM TO START THE TREND. AND WHEREAS THE SRN TAF SITES MAY NOT CLEAR OUT NEARLY AS MUCH...THEY ARE MORE LIKELY TO HAVE THE FRESHEST LLVL MOISTURE TRAPPED AT THE SFC...AND WILL REQUIRE LESS OF A DROP IN TEMPS TO FOG UP IN THE MORNING. BEYOND THAT...DRY AIR THRU THE COLUMN...SUNNY SKIES FOR THE END OF THE WEEK. HJS && .PREV DISCUSSION... ISSUED 225 AM CDT THU JUL 19 2007 AFTER ONE MORE UNSETTLED DAY...COOLER AND DRIER WEATHER WILL RETURN TO CENTRAL ILLINOIS IN TIME FOR THE WEEKEND. 06Z SURFACE MAP CONTINUES TO SHOW STALLED FRONTAL BOUNDARY EXTENDING FROM THE SOUTHERN GREAT LAKES WESTWARD INTO NORTHERN IOWA. THIS BOUNDARY HAS BEEN THE FOCUS FOR NUMEROUS SHOWERS/STORMS ACROSS NORTHERN ILLINOIS OVER THE PAST SEVERAL HOURS. FURTHER NORTH...STRONG COLD FRONT IS DROPPING SOUTHWARD THROUGH THE UPPER MIDWEST...AIDED BY VIGOROUS SHORT-WAVE DIVING OUT OF CANADA. SHORT TERM...TODAY THROUGH SATURDAY CLUSTERS OF SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP ACROSS IOWA...THEN TRACK E/SE ACROSS NORTHERN SECTIONS OF ILLINOIS AND INDIANA FOR THE NEXT FEW HOURS. THIS BAND OF PRECIPITATION WILL GRADUALLY SINK SOUTHWARD INTO THE NORTHERN KILX CWA...REACHING THE I-74 CORRIDOR BY 12Z. BOTH NAM-WRF/RUC SUGGEST PERIODS OF SHOWERS/STORMS FOR MUCH OF THE MORNING ACROSS THIS AREA...BEFORE MAIN FOCUS FOR PRECIP SINKS SOUTHWARD TO NEAR THE I-72 CORRIDOR BY MIDDAY. MCS ACTIVITY ACROSS THE NORTH WILL DIMINISH LATER THIS MORNING AS LOW-LEVEL JET WEAKENS...WHICH WILL REDUCE THE THREAT FOR HEAVY RAINFALL. HOWEVER...GIVEN LATEST RADAR TRENDS AND MODEL FORECASTS...WILL EXTEND THE FLASH FLOOD WATCH FOR THE NORTHERN CWA THROUGH 18Z. MORNING CONVECTION WILL LEAVE BEHIND NUMEROUS OUTFLOW BOUNDARIES...WHICH WILL SERVE AS PRIMARY FOCUS FOR ADDITIONAL CONVECTION THIS AFTERNOON. ATMOSPHERE ACROSS CENTRAL ILLINOIS WILL BE UNCAPPED AND MODERATELY UNSTABLE..WITH CAPE VALUES MAINLY IN THE 1500-2500J/KG RANGE. BEST INSTABILITY WILL DEVELOP ACROSS THE SE CWA...WHERE CONVECTIVE DEBRIS WILL BE THINNEST. LATEST DAY 1 CONVECTIVE OUTLOOK PLACES ALL BUT THE FAR NORTHERN CWA IN A SLIGHT RISK FOR SEVERE TODAY...BUT BASED ON EXPECTED TRACK OF MORNING CONVECTION AND PROBABLE LOCATION OF OUTFLOW BOUNDARIES...THINK PRIMARY EMPHASIS FOR STRONG TO SEVERE STORMS WILL BE SOUTH OF I-72 THIS AFTERNOON. WITH ALL THE CLOUDS AND RAIN AROUND TODAY...TEMPS WILL BE HELD DOWN QUITE A BIT ACROSS MANY AREAS. NUMERIC GUIDANCE IS IN GOOD AGREEMENT ON HIGHS...BUT WILL CONTINUE THE RECENT TREND OF UNDERCUTTING THE MAV NUMBERS...PRODUCING HIGHS RANGING FROM THE LOWER 80S NORTH TO AROUND 90 FAR SOUTH. 00Z JUL 19 MODELS DIFFER ON SPEED OF FRONT LATER TODAY...WITH NAM- WRF BEING SLOWEST. BASED ON STRENGTH OF SHORT-WAVE ON WATER VAPOR IMAGERY...THINK FRONT WILL GET A SOLID PUSH SOUTHWARD. WILL THEREFORE FOLLOW THE FASTER AND MORE CONSISTENT GFS FOR FROPA TIMING. WILL CARRY 30 POPS INTO THE EVENING HOURS ACROSS THE CENTRAL ZONES...WITH 50S FURTHER SOUTH. ALL MODELS DRY THINGS OUT ACROSS THE ENTIRE CWA AFTER MIDNIGHT...BUT WILL HOLD ON TO A 20 POP ALONG AND SOUTH OF I-70 IN CASE FRONT SLOWS A BIT. ONCE FRONT SINKS SOUTH OF ILLINOIS...MUCH COOLER AND DRIER AIRMASS WILL SETTLE INTO THE REGION COURTESY OF CANADIAN HIGH PRESSURE. THERMAL PROFILES SUGGEST HIGH TEMPS ONLY IN THE UPPER 70S AND LOWER 80S FOR FRIDAY...WITH MUCH LOWER HUMIDITY VALUES. CLEAR SKIES AND DRY AIRMASS WILL ALLOW OVERNIGHT LOW TEMPS FRIDAY AND SATURDAY TO DIP INTO THE MIDDLE TO UPPER 50S IN MOST LOCATIONS. LONG TERM...SUNDAY THROUGH WEDNESDAY QUIET WEATHER EXPECTED IN THE EXTENDED...WITH A GRADUAL WARMING TREND SUNDAY THROUGH WEDNESDAY. UPPER RIDGE ACROSS THE PLAINS BUILDS EASTWARD TOWARD THE MIDWEST NEXT WEEK...HELPING PUSH TEMPS BACK TO AROUND THE 90 DEGREE MARK BY TUESDAY. && .ILX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 1 PM CDT THIS AFTERNOON FOR ILZ027>031- 036>038-041>046-053. && $$ il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 243 AM CDT THU JUL 19 2007 .DISCUSSION... ISSUED 225 AM CDT THU JUL 19 2007 AFTER ONE MORE UNSETTLED DAY...COOLER AND DRIER WEATHER WILL RETURN TO CENTRAL ILLINOIS IN TIME FOR THE WEEKEND. 06Z SURFACE MAP CONTINUES TO SHOW STALLED FRONTAL BOUNDARY EXTENDING FROM THE SOUTHERN GREAT LAKES WESTWARD INTO NORTHERN IOWA. THIS BOUNDARY HAS BEEN THE FOCUS FOR NUMEROUS SHOWERS/STORMS ACROSS NORTHERN ILLINOIS OVER THE PAST SEVERAL HOURS. FURTHER NORTH...STRONG COLD FRONT IS DROPPING SOUTHWARD THROUGH THE UPPER MIDWEST...AIDED BY VIGOROUS SHORT-WAVE DIVING OUT OF CANADA. SHORT TERM...TODAY THROUGH SATURDAY CLUSTERS OF SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP ACROSS IOWA...THEN TRACK E/SE ACROSS NORTHERN SECTIONS OF ILLINOIS AND INDIANA FOR THE NEXT FEW HOURS. THIS BAND OF PRECIPITATION WILL GRADUALLY SINK SOUTHWARD INTO THE NORTHERN KILX CWA...REACHING THE I-74 CORRIDOR BY 12Z. BOTH NAM-WRF/RUC SUGGEST PERIODS OF SHOWERS/STORMS FOR MUCH OF THE MORNING ACROSS THIS AREA...BEFORE MAIN FOCUS FOR PRECIP SINKS SOUTHWARD TO NEAR THE I-72 CORRIDOR BY MIDDAY. MCS ACTIVITY ACROSS THE NORTH WILL DIMINISH LATER THIS MORNING AS LOW-LEVEL JET WEAKENS...WHICH WILL REDUCE THE THREAT FOR HEAVY RAINFALL. HOWEVER...GIVEN LATEST RADAR TRENDS AND MODEL FORECASTS...WILL EXTEND THE FLASH FLOOD WATCH FOR THE NORTHERN CWA THROUGH 18Z. MORNING CONVECTION WILL LEAVE BEHIND NUMEROUS OUTFLOW BOUNDARIES...WHICH WILL SERVE AS PRIMARY FOCUS FOR ADDITIONAL CONVECTION THIS AFTERNOON. ATMOSPHERE ACROSS CENTRAL ILLINOIS WILL BE UNCAPPED AND MODERATELY UNSTABLE..WITH CAPE VALUES MAINLY IN THE 1500-2500J/KG RANGE. BEST INSTABILITY WILL DEVELOP ACROSS THE SE CWA...WHERE CONVECTIVE DEBRIS WILL BE THINNEST. LATEST DAY 1 CONVECTIVE OUTLOOK PLACES ALL BUT THE FAR NORTHERN CWA IN A SLIGHT RISK FOR SEVERE TODAY...BUT BASED ON EXPECTED TRACK OF MORNING CONVECTION AND PROBABLE LOCATION OF OUTFLOW BOUNDARIES...THINK PRIMARY EMPHASIS FOR STRONG TO SEVERE STORMS WILL BE SOUTH OF I-72 THIS AFTERNOON. WITH ALL THE CLOUDS AND RAIN AROUND TODAY...TEMPS WILL BE HELD DOWN QUITE A BIT ACROSS MANY AREAS. NUMERIC GUIDANCE IS IN GOOD AGREEMENT ON HIGHS...BUT WILL CONTINUE THE RECENT TREND OF UNDERCUTTING THE MAV NUMBERS...PRODUCING HIGHS RANGING FROM THE LOWER 80S NORTH TO AROUND 90 FAR SOUTH. 00Z JUL 19 MODELS DIFFER ON SPEED OF FRONT LATER TODAY...WITH NAM- WRF BEING SLOWEST. BASED ON STRENGTH OF SHORT-WAVE ON WATER VAPOR IMAGERY...THINK FRONT WILL GET A SOLID PUSH SOUTHWARD. WILL THEREFORE FOLLOW THE FASTER AND MORE CONSISTENT GFS FOR FROPA TIMING. WILL CARRY 30 POPS INTO THE EVENING HOURS ACROSS THE CENTRAL ZONES...WITH 50S FURTHER SOUTH. ALL MODELS DRY THINGS OUT ACROSS THE ENTIRE CWA AFTER MIDNIGHT...BUT WILL HOLD ON TO A 20 POP ALONG AND SOUTH OF I-70 IN CASE FRONT SLOWS A BIT. ONCE FRONT SINKS SOUTH OF ILLINOIS...MUCH COOLER AND DRIER AIRMASS WILL SETTLE INTO THE REGION COURTESY OF CANADIAN HIGH PRESSURE. THERMAL PROFILES SUGGEST HIGH TEMPS ONLY IN THE UPPER 70S AND LOWER 80S FOR FRIDAY...WITH MUCH LOWER HUMIDITY VALUES. CLEAR SKIES AND DRY AIRMASS WILL ALLOW OVERNIGHT LOW TEMPS FRIDAY AND SATURDAY TO DIP INTO THE MIDDLE TO UPPER 50S IN MOST LOCATIONS. LONG TERM...SUNDAY THROUGH WEDNESDAY QUIET WEATHER EXPECTED IN THE EXTENDED...WITH A GRADUAL WARMING TREND SUNDAY THROUGH WEDNESDAY. UPPER RIDGE ACROSS THE PLAINS BUILDS EASTWARD TOWARD THE MIDWEST NEXT WEEK...HELPING PUSH TEMPS BACK TO AROUND THE 90 DEGREE MARK BY TUESDAY. && .AVIATION... ISSUED 232 AM CDT THU JUL 19 2007 DISCUSSION FOR 06Z TAFS. QUASI STATIONARY FRONT ACROSS THE AREA HAS SLOWLY DRIFTED SOUTH OVER THE PAST COUPLE OF HOURS... REINFORCED/AIDED BY RAIN COOLED AIR / OUTFLOW BOUNDARIES FROM EARLIER CONVECTION. RUC LOW LEVEL THETA SURFACES AND AREA VWP AND PROFILERS INDICATE INCREASING LIFT ALONG THE SAGGING BAROCLINIC ZONE OVER WESTERN ILLINOIS. MEANWHILE... WEAKENING MCS OVER CENTRAL IOWA CONTINUES TO DROP SE... AND THIS SHOULD OVERALL HELP THE FOCUS FOR ELEVATED CONVECTION/ STEADIER RAINFALL SHIFT SLOWLY SOUTHWARD OVER THE NEXT FEW HOURS... AFFECTING NORTHERN TERMINALS OF PIA/BMI INITIALLY... AND EVENTUALLY SHIFTING EASTWARD TO CMI BY 12Z. WILL BE AMENDING 06Z TAFS SHORTLY TO ACCOUNT FOR LONGER DURATION OF SHOWERS AND ISOLATED THUNDER FOR PIA/BMI AND CMI. AS WEAKENING MCS FROM CENTRAL IA MOVES THROUGH... THIS MAY ALLOW THE FRONT ITSELF TO CLEAR THE NORTHERN TERMINALS BY MID-MORNING. OVERALL CONDITIONS WILL BE VFR-MVFR... BUT OCCASIONAL VFR IN HEAVIER SHOWERS AND ISOLATED THUNDERSTORMS. FOCUS FOR STRONGER CONVECTION THIS AFTERNOON KEEPS SHIFTING FARTHER SOUTH AS MCS ACTIVITY HELPS SHOVE QUASI-STATIONARY FRONT FURTHER SOUTHWARD. HARDIMAN && .ILX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 7 AM CDT THIS MORNING FOR ILZ027>031- 036>038-041>046-053. && $$ il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 245 PM CDT THU JUL 19 2007 .SYNOPSIS... MUCH QUIETER WEATHER IS OVERSPREADING THE AREA TODAY. SUBJECTIVE 12Z UPPER AIR ANALYSIS INDICATES STRONG UPPER RIDGE EXTENDING FROM CO NWD TO NRN CANADA...WITH DIGGING ERN TROUGH AS WELL AS LOW DIGGING OFF THE NW PAC COAST. 850MB LOW WAS CENTERED IN SRN ONT...WITH FRONT THROUGH MI TOWARD THE OH RIVER VALLEY...AND 850MB HIGH WAS CENTERED IN SRN AB. DRIER 850MB AIR WAS PUSHING SWD OUT OF THE NRN GREAT LAKES/NRN PLAINS...WITH MOISTURE CONFINED TO S OF THE 850MB BDRY AND OVER THE ROCKIES IN WAKE OF THE 850MB HIGH. SURFACE FRONT AT 19Z WAS SOUTH OF THE CWA...DRAPED FROM THE SURFACE LOW IN NY THROUGH CTRL IN/IL/MO TOWARD A SECONDARY LOW IN SWRN KS/OK PANHANDLE. SECONDARY BDRY WAS ALSO NOTED FROM SRN LK MI THROUGH THE HWY 30 CORRIDOR TOWARD SWRN IA...ALONG A WIND SHIFT AND MOISTURE GRADIENT. SURFACE HIGH WAS CENTERED IN SRN AB/WRN ONT AND DROPPING INTO THE DAKOTAS/MN. SATELLITE IMAGERY INDICATES BACK EDGE OF STRATUS WORKING THROUGH THE NRN CWA AS OF 19Z...WITH STRATUS THINNING WHERE IT DOES REMAIN...AND CLEAR SKIES WELL N INTO NRN IA/MN/WRN WI/DAKOTAS. && .SHORT TERM...TONIGHT AND TOMORROW... MAIN FORECAST CONCERNS ARE FRONTAL PASSAGE TODAY AND POTENTIAL FOR FOG TONIGHT. SECONDARY FRONT HAS DEVELOPED SHOWERS IN THE LAST HOUR...MAINLY IN A LINE FROM KJOT TO KCWI. NAM/RUC INDICATE UP TO 2000 J/KG CAPE AHEAD OF THAT BOUNDARY...THUS WILL INCLUDE WORDING FOR ISOLATED TSRA THIS EVENING AS THAT BOUNDARY SAGS SOUTH. BEHIND THAT LINE...SKIES CLEAR RAPIDLY. MOISTURE HAS BEEN SLOW TO SCOUR OUT OF THE AREA WITH LINGERING CLOUDS. SFC DEWPOINTS IN THE NRN CWA ARE IN THE LOW 60S...WHILE LOW TO MID 70S REMAIN S OF I-80. WITH CLEARING AND CALMING WINDS AFTER SUNSET...CAN EXPECT TEMP/DEWPOINT SPREADS TO BECOME VERY LOW OVERNIGHT EVEN AS DEWPOINTS DROP. SRNMOST CWA MAY ACTUALLY REMAIN CLOUDY FOR A GOOD PART OF THE NIGHT AND NOT DROP AS QUICKLY. HAVE INCLUDED FOG WORDING IN GRIDS...WITH AREAS N OF I-80 AND PATCHY S. POTENTIAL IS THERE FOR SOME LOCALLY DENSE FOG...AND WILL NEED TO BE MONITORED. WITH LIKELIHOOD OF FOG AS WELL AS RELUCTANCE OF MOISTURE TO SCOUR OUT...HAVE INCREASED DEWPOINTS AND MIN TEMPS OVERNIGHT...THOUGH STILL DOWN INTO THE LOW 50S IN THE NRN CWA. WITH COOLER 850MB TEMPS /10-12C/ SPREADING INTO THE CWA TMRW...TEMPS SHOULD STRUGGLE TO GET OUT OF THE 70S. DRIER AIR WILL HELP THE JULY SUN DO ITS WORK...BUT WET GROUND AND COOLER MID-LEVL TEMPS WILL WORK AGAINST IT. HAVE KEPT MAX TEMP FORECAST ABOUT THE SAME AS PREVIOUS...BUT DID INCREASE DEWPOINTS SLIGHTLY WITH VERY WET GROUND AFTER A WEEK OF ABUNDANT RAINFALL. ALSO KEPT SKIES CLEAR WITH SUBSIDENCE AND DRY MID/UPPER-LEVEL AIRMASS UPSTREAM. MAYES && .LONG TERM...TOMORROW NIGHT THROUGH THURSDAY... LARGE 500MB RIDGE WILL SET UP OVER THE NATION/S MID-SECTION THROUGH THE PERIOD WITH A DRY SURFACE CANADIAN HIGH OVER THE GREAT LAKES SLOWLY SHIFTING OFF TO THE SOUTHEAST STATES. LOW HUMIDITY LEVELS...LIGHT WINDS...AND GENERALLY CLEAR SKIES WILL BE THE STORY THROUGH THE WEEKEND. THE GFS IS BRINGING A POCKET OF UPPER 30 TO MID 40 SFC DEWPOINTS DOWN ACROSS PARTS OF NW ILLINOIS SATURDAY MORNING...WHILE THE NAM HAS THEM IN THE MID 50S. CURRENTLY SEEING DEWPOINT TEMPS ACROSS ONTARIO...SOURCE REGION OF HIGH...IN THE MID 40S. BELIEVE WITH SURFACE LAYER SO MOIST FROM ALL THE RECENT RAINS...THE GFS IS OVERDONE...BUT UPPER 40 TO LOW 50 SFC DEWPOINTS NOT UNREASONABLE. THUS...POTENTIAL FOR NEAR RECORD MINS...ESPECIALLY NEAR DUBUQUE...STILL EXISTS. SEE CHART BELOW. A GRADUAL WARMING TREND WILL COMMENCE SUNDAY ALONG WITH AN INCREASE IN HUMIDITY LEVELS...AS SOUTH TO SOUTHWEST FLOW...ALBEIT WEAK...GETS RE-ESTABLISHED ON THE BACKSIDE OF THE DEPARTING HIGH. BELIEVE GUIDANCE IS OVERDONE ON WARM-UP DUE TO HIGH MOISTURE LEVELS...THUS HAVE LOWERED TEMPS THROUGH THE PERIOD A TOUCH. OTHERWISE...NO MAJOR CHANGES. RECORD MINS 7/21 ---------------------- BURLINGTON 51 1970+ CEDAR RAPIDS 47 1944 DUBUQUE 50 1882 MOLINE 50 1944 14 && .AVIATION... MVFR TO IFR CIGS LINGERING AT KMLI/KBRL ARE GIVING WAY TO VFR CONDITIONS. MAY SEE 2SM OR LOWER FOG FORM AT KDBQ/KCID/KMLI TONIGHT WITH CALMING CONDITIONS...FALLING TEMPS...AND LOTS OF MOISTURE NEAR THE GROUND. AFTER 12-13Z...FOG SHOULD LIFT AND LEAVE VFR CONDITIONS THROUGH TOMORROW. MAYES && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ MAYES/14 ia AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WICHITA KS 631 PM CDT FRI JUL 20 2007 .UPDATE... RUC AND EXTRAPOLATED LAPS DATA SUGGEST A REMOTE CHANCE FOR A FEW STORMS AS FAR WEST AS ELLSWORTH TO HUTCH TO GREATER WICHITA UNTIL DARK. HOWEVER BETTER CHANCE FOR ISOLATED TO WIDELY SCATTERED STORMS TO CONTINUE THIS EVENING FOR THE FLINT HILLS AND SOUTHEAST KANSAS. KED && .AVIATION... FOR THE 00Z TAF SUITE...VFR CONDITIONS EXPECTED THROUGH THE FORECAST VALID TIME...OUTSIDE OF ISOLATED TO WIDELY SCATTERED CONVECTION. THE KCNU AND KSLN TAF SITES WILL BE MOST IMPACTED...MAINLY THIS EVENING WITH THE THUNDERSTORM ACTIVITY. KED && .PREV DISCUSSION... /ISSUED 248 PM CDT FRI JUL 20 2007/ DISCUSSION... FORECAST CHALLENGES ARE PRECIPITATION CHANCES TONIGHT AND TEMPERATURES FOR THE NEXT FEW DAYS. TONIGHT: CURRENT VISIBLE SATELLITE SHOWS CUMULUS DEVELOPMENT ACROSS MUCH OF KANSAS...AS WELL AS THE REMNANTS OF AN MCV OVER SOUTHWEST KANSAS. THE WARM FRONT THAT WAS ACROSS KANSAS YESTERDAY HAS WASHED OUT AND THERE ARE REALLY NO INDICATIONS OF A BOUNDARY ANYMORE. TEMPERATURES HAVE BEEN ABLE TO CLIMB A COUPLE DEGREES HIGHER THAN WE EXPECTED TODAY...BUT WERE STILL A FEW DEGREES BELOW NORMAL. A FEW SHOWERS AND THUNDERSTORMS DEVELOPED ALONG AN INSTABILITY AXIS THAT STRETCHES ACROSS SOUTHEAST KANSAS...BUT THEY QUICKLY WEAKENED. THIS TREND IS EXPECTED TO CONTINUE THROUGH THE NIGHT. PRECIPITATION CHANCES WERE TRIMMED BACK TO JUST SOUTHEAST KANSAS OVERNIGHT. SATURDAY-SUNDAY: SOUTHERLY TO SOUTHEASTERLY FLOW AT THE SURFACE CONTINUES THROUGH THE WEEKEND...AND MOISTURE TRANSPORT IS MAINLY FOCUSED INTO SOUTHWEST KANSAS. THERE REMAINS SOME WEAK FORCING IN THE MID-LEVELS ACROSS SOUTHEAST KANSAS...BUT CONFIDENCE IS LOW THAT MORE THAN AN ISOLATED STORM OR TWO WILL BE ABLE TO DEVELOP. 1000-850MB THICKNESSES SUPPORT AT OR SLIGHTLY BELOW NORMAL TEMPERATURES THROUGH THE WEEKEND...THEREFORE WE BROUGHT MAXIMUM TEMPERATURES DOWN JUST A BIT TO ACCOUNT FOR THIS AND THE FACT THAT IT HAS BEEN A STRUGGLE TO GET ABOVE THE LOW 90S ACROSS THE FORECAST AREA WITH THE EXCEPTION OF CENTRAL KANSAS THIS SUMMER. MONDAY-THURSDAY: UPPER RIDGE IN PLACE DURING THIS TIME...WITH DRY WEATHER EXPECTED. THERE ARE SOME HINTS AT SOME WEAK RIPPLES IN THE FLOW...HOWEVER WITH TIMING AND TRACK OF THESE IMPULSES SURE TO CHANGE QUITE A BIT IN THE NEXT FEW DAYS...OPTED TO KEEP THE FORECAST DRY FOR NOW. 1000-850MB THICKNESSES DO NOT SUPPORT MID-90S FOR MUCH OF THE FORECAST AREA...RATHER LOW 90S...SO WE LOWERED MAX TEMPERATURES A COUPLE DEGREES TO ACCOUNT FOR THIS ESPECIALLY GIVEN THE STRUGGLE WE HAVE HAD THIS YEAR TO MAKE IT ABOVE THE LOW 90S THIS YEAR. SCHRECK AVIATION...FOR 18Z TAF ISSUANCE LATEST RADAR LOOP IS SHOWING SEVERAL SHOWERS AND THUNDERSTORMS STARTING TO DEVELOP ALONG THE INSTABILITY AXIS STRETCHING FROM CHANUTE TOWARDS SALINA. WE HAVE INTRODUCED A TEMPO TSRA GROUP FOR THE CHANUTE TAF THIS AFTERNOON...BUT WE HAVE HELD OFF AT SALINA UNTIL WE SEE A LITTLE MORE EVIDENCE. THE REMAINDER OF THE TAF SITES WILL SEE MAINLY CUMULUS THIS AFTERNOON...BUT YOU CANNOT RULE OUT A STORM OR TWO IN THE VICINITY. THIS THUNDERSTORM ACTIVITY SHOULD BEGIN TO DIE OFF AFTER SUNSET. WE DID MENTION SOME PATCHY BR IN THE CHANUTE TAF TOWARDS SUNRISE SINCE THERE IS A LOT OF LOW LEVEL MOISTURE IN PLACE ALONG WITH SOME DECOUPLING ACCORDING TO THE GFS. COX && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 68 93 70 93 / 20 10 10 10 HUTCHINSON 69 93 70 93 / 10 10 10 10 NEWTON 68 92 69 93 / 20 10 10 10 ELDORADO 67 92 69 92 / 30 10 10 10 WINFIELD-KWLD 69 93 70 92 / 20 10 10 10 RUSSELL 69 93 70 95 / 10 0 10 10 GREAT BEND 69 94 70 94 / 10 10 10 10 SALINA 67 92 69 93 / 20 10 10 10 MCPHERSON 68 93 69 93 / 20 10 10 10 COFFEYVILLE 67 92 68 90 / 30 20 10 10 CHANUTE 66 91 67 90 / 30 20 10 10 IOLA 66 91 67 90 / 30 10 10 10 PARSONS-KPPF 66 92 68 90 / 30 20 10 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 207 PM MDT FRI JUL 20 2007 .SHORT TERM... (TONIGHT - MONDAY) PRIMARILY A TEMPERATURE FORECAST WITH UPPER RIDGING IN PLACE. EASTERLY SURFACE WINDS WILL VEER TO SOUTH TONIGHT AS SURFACE HIGH SLIDES AWAY TOWARDS THE GREAT LAKES. HOWEVER EASTERLY COMPONENT WILL PERSIST ACROSS NORTHEAST CORNER OF THE CWA THROUGH 12Z SATURDAY...AND THAT IS WHERE RUC INSISTS ON FOG DEVELOPING. NAM PAINTS SIMILAR PICTURE. GIVEN HIGH SURFACE DEW POINTS AND CLEARING SKIES HARD TO ARGUE AGAINST THAT SCENARIO. ON SATURDAY...PRESSURE GRADIENT TIGHTENS AS LEE TROUGH DEVELOPS IN EASTERN COLORADO UNDER RIDGE ALOFT. EXPECT TO SEE BREEZY CONDITIONS WEST OF HIGHWAY 83 AND INTO EASTERN COLORADO BY THE AFTERNOON. VERY LITTLE CHANGES ON SUNDAY...BUT WINDS DO LOOK TO COME DOWN WHILE 850MB TEMPERATURES NUDGE A BIT HIGHER. AGAIN NO PRECIPITATION EXPECTED. ON MONDAY...MODELS ACTUALLY DROP A FEW DEGREES C AT 850. APPEARS CWA MAY BENEFIT FROM SLIGHT COLD ADVECTION ASSOCIATED WITH SHORTWAVE COMING AROUND THE RIDGE AND MOVING SOUTHEAST ACROSS EASTERN KANSAS. GIVEN GOOD MODEL AGREEMENT WILL TRIM A BIT OFF THE TOP FOR MONDAY TEMPERATURES. .LONG TERM... (TUESDAY - FRIDAY) SPRAWLING 595DAM UPPER RIDGE CENTERED OVER THE NORTHERN PLAINS WILL DOMINATE THIS FORECAST PERIOD. JET/STORM TRACK WILL BE FAR NORTH IN CENTRAL CANADA. PACIFIC NORTHWEST DISTURBANCES WILL HAVE TO RIDE UP AND OVER THE RIDGE...PRECLUDING ANY SYNOPTIC SCALE LIFT FOR PRECIPITATION IN THE LOCAL AREA. INTERESTING FEATURE OVER THE EAST COAST...WHERE CUT OFF LOW FORECAST BY THE ECMWF TO RETROGRADE AS FAR WEST AS THE UPPER MISSISSIPPI RIVER VALLEY BY MIDWEEK...CAUGHT BETWEEN THE NORTHERN PLAINS RIDGE AND BERMUDA HIGH. STILL...SHOULD NOT PROGRESS MUCH FURTHER WEST AND NOT BE A LOCAL FACTOR. SO GENERAL FLAVOR OF THE LONG TERM WILL BE HOT AND DRY. GOOD AGREEMENT BETWEEN THE MODELS WITH 850MB TEMPERATURES STEADILY RISING FROM THE UPPER 20S CELSIUS TO LOWER 30S BY THE END OF THE PERIOD. THIS WILL TRANSLATE TO SURFACE TEMPERATURES STEADILY RISING THROUGH THE 90S AND LIKELY REACHING TRIPLE DIGITS AGAIN BY LATE IN THE PERIOD. && .AVIATION... LOW DEW POINT DEPRESSIONS AFTER 09Z WILL PRODUCE IFR CEILINGS/VISIBILITIES AT KMCK. RUC MODEL HANDLES THIS TREND WELL. VISIBILITIES/CEILINGS MAY DROP AT KGLD ALSO...BUT THERE MAY BE ENOUGH MIXING TO KEEP CONDITIONS IN THE MVFR CATEGORY. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ JDK/JDK/SAM ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WICHITA KS 1249 PM CDT FRI JUL 20 2007 .UPDATE... WE ARE RAISING POPS FOR THIS AFTERNOON MAINLY ALONG THE NORTHEAST SECTION OF OUR FORECAST AREA. LATEST SURFACE ANALYSIS/LAPS DATA IS SHOWING AN INSTABILITY AXIS STRETCHING FROM JUST NORTHEAST OF SALINA TO NEAR IOLA. MIXED LAYER CAPES ACROSS THIS REGION IS ON THE ORDER OF 2000-2500J/KG. HOWEVER...NEODESHA AND HILLSBORO PROFILERS ARE SHOWING VERY LITTLE IF ANY SHEAR. THEREFORE...I WOULD ANTICIPATE MOST OF THESE STORMS TO BE HEAVY RAINFALL PRODUCERS WITH AN ISOLATED WIND GUST UP TO 40 MPH POSSIBLE. RAINFALL AMOUNTS COULD EXCEED AN INCH IN SOME OF THESE HEAVY DOWNPOURS. COX && .PREV DISCUSSION... /ISSUED 1235 PM CDT FRI JUL 20 2007/ AVIATION...FOR 18Z TAF ISSUANCE LATEST RADAR LOOP IS SHOWING SEVERAL SHOWERS AND THUNDERSTORMS STARTING TO DEVELOP ALONG THE INSTABILITY AXIS STRETCHING FROM CHANUTE TOWARDS SALINA. WE HAVE INTRODUCED A TEMPO TSRA GROUP FOR THE CHANUTE TAF THIS AFTERNOON...BUT WE HAVE HELD OFF AT SALINA UNTIL WE SEE A LITTLE MORE EVIDENCE. THE REMAINDER OF THE TAF SITES WILL SEE MAINLY CUMULUS THIS AFTERNOON...BUT YOU CANNOT RULE OUT A STORM OR TWO IN THE VICINITY. THIS THUNDERSTORM ACTIVITY SHOULD BEGIN TO DIE OFF AFTER SUNSET. WE DID MENTION SOME PATCHY BR IN THE CHANUTE TAF TOWARDS SUNRISE SINCE THERE IS A LOT OF LOW LEVEL MOISTURE IN PLACE ALONG WITH SOME DECOUPLING ACCORDING TO THE GFS. COX PREV DISCUSSION... /ISSUED 1154 AM CDT FRI JUL 20 2007/ UPDATE... WE ARE SENDING OUT A QUICK UPDATE TO RAISE TEMPERATURES. LAPS DATA AND SURFACE ANALYSIS ARE SHOWING THE INSTABILITY AXIS SETTING UP FROM CENTRAL INTO SOUTHEAST KANSAS. WE MAY NEED TO TWEAK POPS IN THE NEAR FUTURE. OTHERWISE...WE RAISED TEMPERATURES A COUPLE OF DEGREES TO REFLECT THE CURRENT TRENDS. TEMPERATURES SHOULD STABILIZE EARLY THIS AFTERNOON ONCE THE CONVECTIVE TEMPERATURE IS REACHED. COX PREV DISCUSSION... /ISSUED 939 AM CDT FRI JUL 20 2007/ UPDATE... WE ARE SENDING OUT AN UPDATE TO LOWER POPS THIS MORNING AND THIS AFTERNOON. LATEST WATER VAPOR LOOP IS SHOWING THE REMNANTS OF THE MESOSCALE CONVECTIVE SYSTEM (MCS) OVER CENTRAL KANSAS. THIS MCS HAS INDUCED A MID LEVEL MESOSCALE CONVECTIVE VORT LOBE (MCV)OVER THIS SAME REGION THIS MORNING. THE LATEST RUC/NAM-WRF ARE SHIFTING THIS MCV SOUTH INTO THE SOUTHWEST PART OF THE FORECAST AREA THIS AFTERNOON. AS A RESULT...WE COULD SEE A FEW STORMS DEVELOP MAINLY ALONG AND SOUTHWEST OF A GREAT BEND TO WINFIELD LINE. THE REMAINDER OF THE AREA...WILL BE MOSTLY DRY EXCEPT FOR A ISOLATED STORM OR TWO DUE TO WEAK CONVECTIVE INHIBITION AND A WEAK BOUNDARY (NEARLY WASHED OUT) SITUATED IN THE NORTHEAST SECTION OF OUR FORECAST AREA. WE ALSO LOWERED POPS CONSIDERABLY DURING THE MORNING TIME FRAME. COX DISCUSSION... WE ARE SENDING OUT AN UPDATE TO LOWER POPS THIS MORNING AND THIS AFTERNOON. LATEST WATER VAPOR LOOP IS SHOWING THE REMNANTS OF THE MESOSCALE CONVECTIVE SYSTEM (MCS) OVER CENTRAL KANSAS. THIS MCS HAS INDUCED A MID LEVEL MESOSCALE CONVECTIVE VORT LOBE (MCV)OVER THIS SAME REGION THIS MORNING. THE LATEST RUC/NAM-WRF ARE SHIFTING THIS MCV SOUTH INTO THE SOUTHWEST PART OF THE FORECAST AREA THIS AFTERNOON. AS A RESULT...WE COULD SEE A FEW STORMS DEVELOP MAINLY ALONG AND SOUTHWEST OF A GREAT BEND TO WINFIELD LINE. THE REMAINDER OF THE AREA...WILL BE MOSTLY DRY EXCEPT FOR A ISOLATED STORM OR TWO DUE TO WEAK CONVECTIVE INHIBITION AND A WEAK BOUNDARY (NEARLY WASHED OUT) SITUATED IN THE NORTHEAST SECTION OF OUR FORECAST AREA. WE ALSO LOWERED POPS CONSIDERABLY DURING THE MORNING TIME FRAME. PREV DISCUSSION... /ISSUED 552 AM CDT FRI JUL 20 2007/ AVIATION... UPDATE FOR 12Z TAFS...EXPECTING MAINLY VFR CONDITIONS TODAY WITH SCATTERED THUNDERSTORMS AFFECTING SOME TAF SITES AT TIMES FOR THE MORNING AND AFTERNOON HOURS. THE THUNDERSTORMS SHOULD GRADUALLY TAPER OFF ACROSS THE AREA AFTER 00Z. JAKUB PREV DISCUSSION... /ISSUED 318 AM CDT FRI JUL 20 2007/ DISCUSSION... FORECAST CONCERNS ARE CONVECTION CHANCE FOR TODAY AND INTO TONIGHT. TODAY: THIS MORNING A BAND OF THUNDERSTORMS CONTINUE ACROSS NORTH CENTRAL KANSAS. THIS IS WHERE A WEAK SURFACE BOUNDARY WAS LOCATED AND THE 310K INDICATED FAIRLY GOOD ISENTROPIC LIFT. THE SURFACE BOUNDARY WILL DOMINATE OUR WEATHER THROUGH THE DAY. CONVECTION IS EXPECTED TO INCREASE THIS MORNING AND ARE ALREADY SEEING EVIDENCE OF THAT AS THE ALTOCUMULS CLOUDS OVER SOUTH CENTRAL KANSAS EXPAND BOTH IN COVERAGE AND VERTICAL EXTENT. BY AFTERNOON THE BOUNDARY SHOULD EXTEND FROM NORTHEAST OKLAHOMA TO WEST CENTRAL KANSAS. KEPT CHANCES OF THUNDERSTORMS OVER THE ENTIRE AREA TODAY...BUT BY LATE AFTERNOON SHOULD SEE THE BEST CHANCES OF STORMS CONFINED TO THE SOUTHERN HALF OF THE AREA AS THE BOUNDARY CONTINUES TO DRIFT TO THE SOUTHWEST. MAINTAINED THE HIGH TEMPERATURE FORECAST AS IS...WITH HIGHS IN THE MID 80S MOST AREAS CONSIDERING THE AMOUNT OF CLOUDS AND CHANCES OF THUNDERSTORMS. SATURDAY: LOOKS AS THOUGH BOUNDARY WILL CONTINUE TO WASH OUT AS SURFACE HIGH PRESSURE DOMINATES THE AREA. LEFT SOME SLIGHT CHANCES FOR THUNDERSTORMS IN SOUTHEAST KANSAS WHERE SURFACE MOISTURE AND UPSLOPE FLOW IS GREATEST. REMAINDER OF THE AREA SHOULD BE DRY. SUNDAY THROUGH MONDAY: WILL KEEP THIS TIME FRAME DRY FOR NOW...BUT POSSIBLE MESOSCALE CONVECTIVE VORT MAXES COULD DRIFT INTO THE AREA AGAIN FROM THE NORTH AND EAST. NOT REAL CONFIDENT THIS PERIOD WILL BE COMPLETELY DRY. WITH UPPER RIDGE IN PLACE...AM PRETTY CONFIDENT THAT TEMPS WILL BE AT OR SLIGHTLY ABOVE SEASONAL NORMS. TUESDAY THROUGH THURSDAY: CURRENT FORECAST ON TRACK WITH A CONTINUATION OF BEING DOMINATED BY THE UPPER RIDGE. MODELS CONTINUE TO SHOW A WEAK IMPULSE GETTING CAUGHT UNDER THE RIDGE AND DRIFTING BACK WEST INTO ARKANSAS AND OKLAHOMA BY THURSDAY...WHICH COULD LEAD TO SOME SCATTERED CONVECTION BY THURSDAY AFTERNOON. KEPT THE LOW POPS FOR THUNDERSTORMS IN SOUTHEAST KANSAS WITH SEASONAL TEMPERATURES. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 90 68 91 70 / 30 20 10 10 HUTCHINSON 90 69 91 70 / 40 20 10 10 NEWTON 89 68 90 69 / 40 20 10 10 ELDORADO 89 67 90 69 / 40 20 10 10 WINFIELD-KWLD 90 69 91 70 / 30 20 20 10 RUSSELL 89 69 91 70 / 30 10 10 10 GREAT BEND 90 69 92 70 / 30 20 10 10 SALINA 88 67 90 69 / 30 10 10 10 MCPHERSON 89 68 91 69 / 40 20 10 10 COFFEYVILLE 88 67 90 68 / 40 20 20 10 CHANUTE 87 66 89 67 / 40 20 20 10 IOLA 87 66 89 67 / 40 20 10 10 PARSONS-KPPF 88 66 90 68 / 40 20 20 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WICHITA KS 1235 PM CDT FRI JUL 20 2007 .AVIATION...FOR 18Z TAF ISSUANCE LATEST RADAR LOOP IS SHOWING SEVERAL SHOWERS AND THUNDERSTORMS STARTING TO DEVELOP ALONG THE INSTABILITY AXIS STRETCHING FROM CHANUTE TOWARDS SALINA. WE HAVE INTRODUCED A TEMPO TSRA GROUP FOR THE CHANUTE TAF THIS AFTERNOON...BUT WE HAVE HELD OFF AT SALINA UNTIL WE SEE A LITTLE MORE EVIDENCE. THE REMAINDER OF THE TAF SITES WILL SEE MAINLY CUMULUS THIS AFTERNOON...BUT YOU CANNOT RULE OUT A STORM OR TWO IN THE VICINITY. THIS THUNDERSTORM ACTIVITY SHOULD BEGIN TO DIE OFF AFTER SUNSET. WE DID MENTION SOME PATCHY BR IN THE CHANUTE TAF TOWARDS SUNRISE SINCE THERE IS A LOT OF LOW LEVEL MOISTURE IN PLACE ALONG WITH SOME DECOUPLING ACCORDING TO THE GFS. COX && .PREV DISCUSSION... /ISSUED 1154 AM CDT FRI JUL 20 2007/ UPDATE... WE ARE SENDING OUT A QUICK UPDATE TO RAISE TEMPERATURES. LAPS DATA AND SURFACE ANALYSIS ARE SHOWING THE INSTABILITY AXIS SETTING UP FROM CENTRAL INTO SOUTHEAST KANSAS. WE MAY NEED TO TWEAK POPS IN THE NEAR FUTURE. OTHERWISE...WE RAISED TEMPERATURES A COUPLE OF DEGREES TO REFLECT THE CURRENT TRENDS. TEMPERATURES SHOULD STABILIZE EARLY THIS AFTERNOON ONCE THE CONVECTIVE TEMPERATURE IS REACHED. COX PREV DISCUSSION... /ISSUED 939 AM CDT FRI JUL 20 2007/ UPDATE... WE ARE SENDING OUT AN UPDATE TO LOWER POPS THIS MORNING AND THIS AFTERNOON. LATEST WATER VAPOR LOOP IS SHOWING THE REMNANTS OF THE MESOSCALE CONVECTIVE SYSTEM (MCS) OVER CENTRAL KANSAS. THIS MCS HAS INDUCED A MID LEVEL MESOSCALE CONVECTIVE VORT LOBE (MCV)OVER THIS SAME REGION THIS MORNING. THE LATEST RUC/NAM-WRF ARE SHIFTING THIS MCV SOUTH INTO THE SOUTHWEST PART OF THE FORECAST AREA THIS AFTERNOON. AS A RESULT...WE COULD SEE A FEW STORMS DEVELOP MAINLY ALONG AND SOUTHWEST OF A GREAT BEND TO WINFIELD LINE. THE REMAINDER OF THE AREA...WILL BE MOSTLY DRY EXCEPT FOR A ISOLATED STORM OR TWO DUE TO WEAK CONVECTIVE INHIBITION AND A WEAK BOUNDARY (NEARLY WASHED OUT) SITUATED IN THE NORTHEAST SECTION OF OUR FORECAST AREA. WE ALSO LOWERED POPS CONSIDERABLY DURING THE MORNING TIME FRAME. COX DISCUSSION... WE ARE SENDING OUT AN UPDATE TO LOWER POPS THIS MORNING AND THIS AFTERNOON. LATEST WATER VAPOR LOOP IS SHOWING THE REMNANTS OF THE MESOSCALE CONVECTIVE SYSTEM (MCS) OVER CENTRAL KANSAS. THIS MCS HAS INDUCED A MID LEVEL MESOSCALE CONVECTIVE VORT LOBE (MCV)OVER THIS SAME REGION THIS MORNING. THE LATEST RUC/NAM-WRF ARE SHIFTING THIS MCV SOUTH INTO THE SOUTHWEST PART OF THE FORECAST AREA THIS AFTERNOON. AS A RESULT...WE COULD SEE A FEW STORMS DEVELOP MAINLY ALONG AND SOUTHWEST OF A GREAT BEND TO WINFIELD LINE. THE REMAINDER OF THE AREA...WILL BE MOSTLY DRY EXCEPT FOR A ISOLATED STORM OR TWO DUE TO WEAK CONVECTIVE INHIBITION AND A WEAK BOUNDARY (NEARLY WASHED OUT) SITUATED IN THE NORTHEAST SECTION OF OUR FORECAST AREA. WE ALSO LOWERED POPS CONSIDERABLY DURING THE MORNING TIME FRAME. PREV DISCUSSION... /ISSUED 552 AM CDT FRI JUL 20 2007/ AVIATION... UPDATE FOR 12Z TAFS...EXPECTING MAINLY VFR CONDITIONS TODAY WITH SCATTERED THUNDERSTORMS AFFECTING SOME TAF SITES AT TIMES FOR THE MORNING AND AFTERNOON HOURS. THE THUNDERSTORMS SHOULD GRADUALLY TAPER OFF ACROSS THE AREA AFTER 00Z. JAKUB PREV DISCUSSION... /ISSUED 318 AM CDT FRI JUL 20 2007/ DISCUSSION... FORECAST CONCERNS ARE CONVECTION CHANCE FOR TODAY AND INTO TONIGHT. TODAY: THIS MORNING A BAND OF THUNDERSTORMS CONTINUE ACROSS NORTH CENTRAL KANSAS. THIS IS WHERE A WEAK SURFACE BOUNDARY WAS LOCATED AND THE 310K INDICATED FAIRLY GOOD ISENTROPIC LIFT. THE SURFACE BOUNDARY WILL DOMINATE OUR WEATHER THROUGH THE DAY. CONVECTION IS EXPECTED TO INCREASE THIS MORNING AND ARE ALREADY SEEING EVIDENCE OF THAT AS THE ALTOCUMULS CLOUDS OVER SOUTH CENTRAL KANSAS EXPAND BOTH IN COVERAGE AND VERTICAL EXTENT. BY AFTERNOON THE BOUNDARY SHOULD EXTEND FROM NORTHEAST OKLAHOMA TO WEST CENTRAL KANSAS. KEPT CHANCES OF THUNDERSTORMS OVER THE ENTIRE AREA TODAY...BUT BY LATE AFTERNOON SHOULD SEE THE BEST CHANCES OF STORMS CONFINED TO THE SOUTHERN HALF OF THE AREA AS THE BOUNDARY CONTINUES TO DRIFT TO THE SOUTHWEST. MAINTAINED THE HIGH TEMPERATURE FORECAST AS IS...WITH HIGHS IN THE MID 80S MOST AREAS CONSIDERING THE AMOUNT OF CLOUDS AND CHANCES OF THUNDERSTORMS. SATURDAY: LOOKS AS THOUGH BOUNDARY WILL CONTINUE TO WASH OUT AS SURFACE HIGH PRESSURE DOMINATES THE AREA. LEFT SOME SLIGHT CHANCES FOR THUNDERSTORMS IN SOUTHEAST KANSAS WHERE SURFACE MOISTURE AND UPSLOPE FLOW IS GREATEST. REMAINDER OF THE AREA SHOULD BE DRY. SUNDAY THROUGH MONDAY: WILL KEEP THIS TIME FRAME DRY FOR NOW...BUT POSSIBLE MESOSCALE CONVECTIVE VORT MAXES COULD DRIFT INTO THE AREA AGAIN FROM THE NORTH AND EAST. NOT REAL CONFIDENT THIS PERIOD WILL BE COMPLETELY DRY. WITH UPPER RIDGE IN PLACE...AM PRETTY CONFIDENT THAT TEMPS WILL BE AT OR SLIGHTLY ABOVE SEASONAL NORMS. TUESDAY THROUGH THURSDAY: CURRENT FORECAST ON TRACK WITH A CONTINUATION OF BEING DOMINATED BY THE UPPER RIDGE. MODELS CONTINUE TO SHOW A WEAK IMPULSE GETTING CAUGHT UNDER THE RIDGE AND DRIFTING BACK WEST INTO ARKANSAS AND OKLAHOMA BY THURSDAY...WHICH COULD LEAD TO SOME SCATTERED CONVECTION BY THURSDAY AFTERNOON. KEPT THE LOW POPS FOR THUNDERSTORMS IN SOUTHEAST KANSAS WITH SEASONAL TEMPERATURES. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 90 68 91 70 / 30 20 10 10 HUTCHINSON 90 69 91 70 / 40 20 10 10 NEWTON 89 68 90 69 / 40 20 10 10 ELDORADO 89 67 90 69 / 40 20 10 10 WINFIELD-KWLD 90 69 91 70 / 30 20 20 10 RUSSELL 89 69 91 70 / 30 10 10 10 GREAT BEND 90 69 92 70 / 30 20 10 10 SALINA 88 67 90 69 / 30 10 10 10 MCPHERSON 89 68 91 69 / 40 20 10 10 COFFEYVILLE 88 67 90 68 / 40 20 20 10 CHANUTE 87 66 89 67 / 40 20 20 10 IOLA 87 66 89 67 / 40 20 10 10 PARSONS-KPPF 88 66 90 68 / 40 20 20 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WICHITA KS 1154 AM CDT FRI JUL 20 2007 .UPDATE... WE ARE SENDING OUT A QUICK UPDATE TO RAISE TEMPERATURES. LAPS DATA AND SURFACE ANALYSIS ARE SHOWING THE INSTABILITY AXIS SETTING UP FROM CENTRAL INTO SOUTHEAST KANSAS. WE MAY NEED TO TWEAK POPS IN THE NEAR FUTURE. OTHERWISE...WE RAISED TEMPERATURES A COUPLE OF DEGREES TO REFLECT THE CURRENT TRENDS. TEMPERATURES SHOULD STABILIZE EARLY THIS AFTERNOON ONCE THE CONVECTIVE TEMPERATURE IS REACHED. COX && .PREV DISCUSSION... /ISSUED 939 AM CDT FRI JUL 20 2007/ UPDATE... WE ARE SENDING OUT AN UPDATE TO LOWER POPS THIS MORNING AND THIS AFTERNOON. LATEST WATER VAPOR LOOP IS SHOWING THE REMNANTS OF THE MESOSCALE CONVECTIVE SYSTEM (MCS) OVER CENTRAL KANSAS. THIS MCS HAS INDUCED A MID LEVEL MESOSCALE CONVECTIVE VORT LOBE (MCV)OVER THIS SAME REGION THIS MORNING. THE LATEST RUC/NAM-WRF ARE SHIFTING THIS MCV SOUTH INTO THE SOUTHWEST PART OF THE FORECAST AREA THIS AFTERNOON. AS A RESULT...WE COULD SEE A FEW STORMS DEVELOP MAINLY ALONG AND SOUTHWEST OF A GREAT BEND TO WINFIELD LINE. THE REMAINDER OF THE AREA...WILL BE MOSTLY DRY EXCEPT FOR A ISOLATED STORM OR TWO DUE TO WEAK CONVECTIVE INHIBITION AND A WEAK BOUNDARY (NEARLY WASHED OUT) SITUATED IN THE NORTHEAST SECTION OF OUR FORECAST AREA. WE ALSO LOWERED POPS CONSIDERABLY DURING THE MORNING TIME FRAME. COX DISCUSSION... WE ARE SENDING OUT AN UPDATE TO LOWER POPS THIS MORNING AND THIS AFTERNOON. LATEST WATER VAPOR LOOP IS SHOWING THE REMNANTS OF THE MESOSCALE CONVECTIVE SYSTEM (MCS) OVER CENTRAL KANSAS. THIS MCS HAS INDUCED A MID LEVEL MESOSCALE CONVECTIVE VORT LOBE (MCV)OVER THIS SAME REGION THIS MORNING. THE LATEST RUC/NAM-WRF ARE SHIFTING THIS MCV SOUTH INTO THE SOUTHWEST PART OF THE FORECAST AREA THIS AFTERNOON. AS A RESULT...WE COULD SEE A FEW STORMS DEVELOP MAINLY ALONG AND SOUTHWEST OF A GREAT BEND TO WINFIELD LINE. THE REMAINDER OF THE AREA...WILL BE MOSTLY DRY EXCEPT FOR A ISOLATED STORM OR TWO DUE TO WEAK CONVECTIVE INHIBITION AND A WEAK BOUNDARY (NEARLY WASHED OUT) SITUATED IN THE NORTHEAST SECTION OF OUR FORECAST AREA. WE ALSO LOWERED POPS CONSIDERABLY DURING THE MORNING TIME FRAME. PREV DISCUSSION... /ISSUED 552 AM CDT FRI JUL 20 2007/ AVIATION... UPDATE FOR 12Z TAFS...EXPECTING MAINLY VFR CONDITIONS TODAY WITH SCATTERED THUNDERSTORMS AFFECTING SOME TAF SITES AT TIMES FOR THE MORNING AND AFTERNOON HOURS. THE THUNDERSTORMS SHOULD GRADUALLY TAPER OFF ACROSS THE AREA AFTER 00Z. JAKUB PREV DISCUSSION... /ISSUED 318 AM CDT FRI JUL 20 2007/ DISCUSSION... FORECAST CONCERNS ARE CONVECTION CHANCE FOR TODAY AND INTO TONIGHT. TODAY: THIS MORNING A BAND OF THUNDERSTORMS CONTINUE ACROSS NORTH CENTRAL KANSAS. THIS IS WHERE A WEAK SURFACE BOUNDARY WAS LOCATED AND THE 310K INDICATED FAIRLY GOOD ISENTROPIC LIFT. THE SURFACE BOUNDARY WILL DOMINATE OUR WEATHER THROUGH THE DAY. CONVECTION IS EXPECTED TO INCREASE THIS MORNING AND ARE ALREADY SEEING EVIDENCE OF THAT AS THE ALTOCUMULS CLOUDS OVER SOUTH CENTRAL KANSAS EXPAND BOTH IN COVERAGE AND VERTICAL EXTENT. BY AFTERNOON THE BOUNDARY SHOULD EXTEND FROM NORTHEAST OKLAHOMA TO WEST CENTRAL KANSAS. KEPT CHANCES OF THUNDERSTORMS OVER THE ENTIRE AREA TODAY...BUT BY LATE AFTERNOON SHOULD SEE THE BEST CHANCES OF STORMS CONFINED TO THE SOUTHERN HALF OF THE AREA AS THE BOUNDARY CONTINUES TO DRIFT TO THE SOUTHWEST. MAINTAINED THE HIGH TEMPERATURE FORECAST AS IS...WITH HIGHS IN THE MID 80S MOST AREAS CONSIDERING THE AMOUNT OF CLOUDS AND CHANCES OF THUNDERSTORMS. SATURDAY: LOOKS AS THOUGH BOUNDARY WILL CONTINUE TO WASH OUT AS SURFACE HIGH PRESSURE DOMINATES THE AREA. LEFT SOME SLIGHT CHANCES FOR THUNDERSTORMS IN SOUTHEAST KANSAS WHERE SURFACE MOISTURE AND UPSLOPE FLOW IS GREATEST. REMAINDER OF THE AREA SHOULD BE DRY. SUNDAY THROUGH MONDAY: WILL KEEP THIS TIME FRAME DRY FOR NOW...BUT POSSIBLE MESOSCALE CONVECTIVE VORT MAXES COULD DRIFT INTO THE AREA AGAIN FROM THE NORTH AND EAST. NOT REAL CONFIDENT THIS PERIOD WILL BE COMPLETELY DRY. WITH UPPER RIDGE IN PLACE...AM PRETTY CONFIDENT THAT TEMPS WILL BE AT OR SLIGHTLY ABOVE SEASONAL NORMS. TUESDAY THROUGH THURSDAY: CURRENT FORECAST ON TRACK WITH A CONTINUATION OF BEING DOMINATED BY THE UPPER RIDGE. MODELS CONTINUE TO SHOW A WEAK IMPULSE GETTING CAUGHT UNDER THE RIDGE AND DRIFTING BACK WEST INTO ARKANSAS AND OKLAHOMA BY THURSDAY...WHICH COULD LEAD TO SOME SCATTERED CONVECTION BY THURSDAY AFTERNOON. KEPT THE LOW POPS FOR THUNDERSTORMS IN SOUTHEAST KANSAS WITH SEASONAL TEMPERATURES. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 90 68 91 70 / 30 20 10 10 HUTCHINSON 90 69 91 70 / 40 20 10 10 NEWTON 89 68 90 69 / 40 20 10 10 ELDORADO 89 67 90 69 / 40 20 10 10 WINFIELD-KWLD 90 69 91 70 / 30 20 20 10 RUSSELL 89 69 91 70 / 30 10 10 10 GREAT BEND 90 69 92 70 / 30 20 10 10 SALINA 88 67 90 69 / 30 10 10 10 MCPHERSON 89 68 91 69 / 40 20 10 10 COFFEYVILLE 88 67 90 68 / 40 20 20 10 CHANUTE 87 66 89 67 / 40 20 20 10 IOLA 87 66 89 67 / 40 20 10 10 PARSONS-KPPF 88 66 90 68 / 40 20 20 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WICHITA KS 939 AM CDT FRI JUL 20 2007 .UPDATE... WE ARE SENDING OUT AN UPDATE TO LOWER POPS THIS MORNING AND THIS AFTERNOON. LATEST WATER VAPOR LOOP IS SHOWING THE REMNANTS OF THE MESOSCALE CONVECTIVE SYSTEM (MCS) OVER CENTRAL KANSAS. THIS MCS HAS INDUCED A MID LEVEL MESOSCALE CONVECTIVE VORT LOBE (MCV)OVER THIS SAME REGION THIS MORNING. THE LATEST RUC/NAM-WRF ARE SHIFTING THIS MCV SOUTH INTO THE SOUTHWEST PART OF THE FORECAST AREA THIS AFTERNOON. AS A RESULT...WE COULD SEE A FEW STORMS DEVELOP MAINLY ALONG AND SOUTHWEST OF A GREAT BEND TO WINFIELD LINE. THE REMAINDER OF THE AREA...WILL BE MOSTLY DRY EXCEPT FOR A ISOLATED STORM OR TWO DUE TO WEAK CONVECTIVE INHIBITION AND A WEAK BOUNDARY (NEARLY WASHED OUT) SITUATED IN THE NORTHEAST SECTION OF OUR FORECAST AREA. WE ALSO LOWERED POPS CONSIDERABLY DURING THE MORNING TIME FRAME. COX && .DISCUSSION... WE ARE SENDING OUT AN UPDATE TO LOWER POPS THIS MORNING AND THIS AFTERNOON. LATEST WATER VAPOR LOOP IS SHOWING THE REMNANTS OF THE MESOSCALE CONVECTIVE SYSTEM (MCS) OVER CENTRAL KANSAS. THIS MCS HAS INDUCED A MID LEVEL MESOSCALE CONVECTIVE VORT LOBE (MCV)OVER THIS SAME REGION THIS MORNING. THE LATEST RUC/NAM-WRF ARE SHIFTING THIS MCV SOUTH INTO THE SOUTHWEST PART OF THE FORECAST AREA THIS AFTERNOON. AS A RESULT...WE COULD SEE A FEW STORMS DEVELOP MAINLY ALONG AND SOUTHWEST OF A GREAT BEND TO WINFIELD LINE. THE REMAINDER OF THE AREA...WILL BE MOSTLY DRY EXCEPT FOR A ISOLATED STORM OR TWO DUE TO WEAK CONVECTIVE INHIBITION AND A WEAK BOUNDARY (NEARLY WASHED OUT) SITUATED IN THE NORTHEAST SECTION OF OUR FORECAST AREA. WE ALSO LOWERED POPS CONSIDERABLY DURING THE MORNING TIME FRAME. && .PREV DISCUSSION... /ISSUED 552 AM CDT FRI JUL 20 2007/ AVIATION... UPDATE FOR 12Z TAFS...EXPECTING MAINLY VFR CONDITIONS TODAY WITH SCATTERED THUNDERSTORMS AFFECTING SOME TAF SITES AT TIMES FOR THE MORNING AND AFTERNOON HOURS. THE THUNDERSTORMS SHOULD GRADUALLY TAPER OFF ACROSS THE AREA AFTER 00Z. JAKUB PREV DISCUSSION... /ISSUED 318 AM CDT FRI JUL 20 2007/ DISCUSSION... FORECAST CONCERNS ARE CONVECTION CHANCE FOR TODAY AND INTO TONIGHT. TODAY: THIS MORNING A BAND OF THUNDERSTORMS CONTINUE ACROSS NORTH CENTRAL KANSAS. THIS IS WHERE A WEAK SURFACE BOUNDARY WAS LOCATED AND THE 310K INDICATED FAIRLY GOOD ISENTROPIC LIFT. THE SURFACE BOUNDARY WILL DOMINATE OUR WEATHER THROUGH THE DAY. CONVECTION IS EXPECTED TO INCREASE THIS MORNING AND ARE ALREADY SEEING EVIDENCE OF THAT AS THE ALTOCUMULS CLOUDS OVER SOUTH CENTRAL KANSAS EXPAND BOTH IN COVERAGE AND VERTICAL EXTENT. BY AFTERNOON THE BOUNDARY SHOULD EXTEND FROM NORTHEAST OKLAHOMA TO WEST CENTRAL KANSAS. KEPT CHANCES OF THUNDERSTORMS OVER THE ENTIRE AREA TODAY...BUT BY LATE AFTERNOON SHOULD SEE THE BEST CHANCES OF STORMS CONFINED TO THE SOUTHERN HALF OF THE AREA AS THE BOUNDARY CONTINUES TO DRIFT TO THE SOUTHWEST. MAINTAINED THE HIGH TEMPERATURE FORECAST AS IS...WITH HIGHS IN THE MID 80S MOST AREAS CONSIDERING THE AMOUNT OF CLOUDS AND CHANCES OF THUNDERSTORMS. SATURDAY: LOOKS AS THOUGH BOUNDARY WILL CONTINUE TO WASH OUT AS SURFACE HIGH PRESSURE DOMINATES THE AREA. LEFT SOME SLIGHT CHANCES FOR THUNDERSTORMS IN SOUTHEAST KANSAS WHERE SURFACE MOISTURE AND UPSLOPE FLOW IS GREATEST. REMAINDER OF THE AREA SHOULD BE DRY. SUNDAY THROUGH MONDAY: WILL KEEP THIS TIME FRAME DRY FOR NOW...BUT POSSIBLE MESOSCALE CONVECTIVE VORT MAXES COULD DRIFT INTO THE AREA AGAIN FROM THE NORTH AND EAST. NOT REAL CONFIDENT THIS PERIOD WILL BE COMPLETELY DRY. WITH UPPER RIDGE IN PLACE...AM PRETTY CONFIDENT THAT TEMPS WILL BE AT OR SLIGHTLY ABOVE SEASONAL NORMS. TUESDAY THROUGH THURSDAY: CURRENT FORECAST ON TRACK WITH A CONTINUATION OF BEING DOMINATED BY THE UPPER RIDGE. MODELS CONTINUE TO SHOW A WEAK IMPULSE GETTING CAUGHT UNDER THE RIDGE AND DRIFTING BACK WEST INTO ARKANSAS AND OKLAHOMA BY THURSDAY...WHICH COULD LEAD TO SOME SCATTERED CONVECTION BY THURSDAY AFTERNOON. KEPT THE LOW POPS FOR THUNDERSTORMS IN SOUTHEAST KANSAS WITH SEASONAL TEMPERATURES. && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 87 68 91 70 / 30 20 10 10 HUTCHINSON 87 69 91 70 / 40 20 10 10 NEWTON 86 68 90 69 / 40 20 10 10 ELDORADO 86 67 90 69 / 40 20 10 10 WINFIELD-KWLD 87 69 91 70 / 30 20 20 10 RUSSELL 87 69 91 70 / 30 10 10 10 GREAT BEND 87 69 92 70 / 30 20 10 10 SALINA 86 67 90 69 / 30 10 10 10 MCPHERSON 86 68 91 69 / 40 20 10 10 COFFEYVILLE 86 67 90 68 / 40 20 20 10 CHANUTE 85 66 89 67 / 40 20 20 10 IOLA 85 66 89 67 / 40 20 10 10 PARSONS-KPPF 86 66 90 68 / 40 20 20 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TOPEKA KS 915 PM CDT THU JUL 19 2007 .DISCUSSION... HAVE UPDATED FORECAST TO KEEP SCATTERED SHOWERS AND THUNDERSTORMS GOING THROUGH THE NIGHT TONIGHT. 00Z RUC AND 18Z NAM SHOW ISENTROPIC LIFT CONTINUING THROUGH THE NIGHT OVER THE STALL BOUNDARY...WHICH AT 02Z WAS SOMEWHERE NEAR SLN TO OTTAWA. WITH LIMITED ELEVATED INSTABILITY INDICATED ON FORECAST SOUNDINGS...THIS LIFT SHOULD BE ENOUGH TO KEEP PRECIP DEVELOPING. A LACK OF SHEAR AND WEAK INSTABILITY SHOULD YIELD MULTI CELL CLUSTERS WITH SLOW STORM MOTIONS. THEREFORE WILL NEED TO WATCH OUT FOR PERIODS OF HEAVY RAIN...AS PWS FROM EVENING SOUNDING STILL GREATER THAN 1.75 INCHES. && WOLTERS .PREV DISCUSSION /335 PM CDT/... SHOWERS AND STORMS STRUGGLING TO DEVELOP OVER THE CWA TODAY. UPPER SHORTWAVE PUSHING FRONT SOUTHWARD ACROSS THE CWA ATTM...HOWEVER DEBRIS CLOUDS AND OUTFLOWS FROM OVERNIGHT CONVECTION IN NEBRASKA HAVE REALLY KEPT A LID ON THE INSTABILITY TODAY. LAPSE RATES IN THE 18Z SOUNDING NOT TERRIBLY IMPRESSIVE AS WELL. WILL KEEP CHANCE POPS FOR THE EVENING HOURS MAINLY ALONG AND SOUTH OF INTERSTATE 70. FRONT PROGGED TO MOVE SLOWLY SOUTHWARD...THEN STALL ACROSS SOUTHERN KANSAS BY EARLY FRIDAY. SOUTHERN COUNTIES HAVE HAD BETTER SUNSHINE TODAY...HOWEVER CLOUDS NOW MOVING IN AND TEMPS STILL IN THE MID 80S SUGGESTING CONVECTION WILL LIKELY STRUGGLE THERE AS WELL. WITH 1600 J/KG CAPE IN THE SOUNDING AND STILL NEARLY 2 INCHES OF WATER...COULD STILL SEE A STRONGER STORM OR TWO ACROSS OUR SOUTH BEFORE THE EVENING IS OUT. ISENTROPIC LIFT OVER THE BOUNDARY STAYS TO OUR SOUTH OVERNIGHT...AND WILL KEEP POP CHANCES FOR THE SOUTHERN COUNTIES BASED MAINLY ON AN UNCERTAIN FRONTAL POSITION. HIGH PRESSURE ESTABLISHES ACROSS THE GREAT LAKES AND WILL BRING COOLER AND SLIGHTLY DRIER AIR INTO THE STATE FROM THE NORTHEAST BY LATE FRIDAY. BIG QUESTION MAY BE TEMPS...AS GUIDANCE DIFFERS ON CLOUD COVER AND THEREFORE HIGHS. HAVE GONE TOWARDS A COOLER SOLUTION GIVEN CURRENT STATE OF THE AIRMASS AND THINKING SOME CU AND STRATUS WILL REMAIN. FOR SATURDAY AND BEYOND...LONG RANGE MODELS CUT OFF UPPER HIGH OVER THE NORTHERN PLAINS AND SLOWLY DRIFT IT EWD. THIS KEEPS US IN NLY/NELY UPPER FLOW THROUGH THE NEXT WEEK. MODELS STRUGGLING WITH WHATEVER MINOR WAVES THAT MAY AFFECT FORECAST AREA. RESIDUAL LOW-LEVEL MOISTURE AND DISSIPATING BOUNDARY IN THE VICINITY COULD LEAD TO DIURNALLY DRIVEN ISOLATED/WIDELY SCATTERED THUNDERSTORMS SATURDAY AND SUNDAY AFTERNOON. BOTH GFS AND NAM WOULD SHOW SOME PRECIP CHANCES SATURDAY...ESPECIALLY ACROSS EC KS...AND NAM TRIES TO DEVELOP MCS SATURDAY NIGHT OVER IA...THAT IT DRIFTS SSWD INTO ERN KS ON SUNDAY. HOWEVER...HAVE OPTED TO KEEP SUNDAY DRY AT THIS TIME AS UPPER VORT MAX THAT AFFECTS AREA SUNDAY IN NAM...COMPLETELY DEPENDENT ON DEVELOPMENT OF IA MCS. WHILE ISOLATED AFTN SHOWERS/THUNDERSTORMS IN TROPICAL AIRMASS NOT OUT OF THE QUESTION FOR MON THROUGH WED...THERE REALLY IS NOTHING TO LATCH ONTO TO INDICATE ANY ORGANIZATION OR TO POINT TO ANY DAY BEING MORE FAVORABLE THAN ANOTHER. ECMWF FROM 00Z AND TO A LESSER EXTENT 00 AND 06Z GFS INDICATED A WWD MOVING WAVE THAT COULD AFFECT PARTS OF THE CENTRAL PLAINS/MISSISSIPPI VALLEY BY NEXT THURSDAY. NEW ECMWF DOES NOT AGREE WITH THIS...BUT HAVE ADDED LOW POPS FOR NEXT THURSDAY IN EC KS BASED ON PREVIOUS MODEL RUNS. WITH LITTLE CHANGE IN AIRMASS OVER NEXT WEEK...TEMPERATURES EXPECTED TO BE MAINLY IN LOWER TO MIDDLE 90S WITH LOWS IN THE MID 60S TO LOW 70S. && .AVIATION... CONCERN THIS EVENING IS WHETHER CONVECTION WILL MOVE INTO TAF SITES. MHK WILL BE CLOSER TO THE ISENTROPIC LIFT AND HAVE INCLUDED A TEMP FOR TS. WILL MONITOR TOP AND FOE...BUT HAVE OPTED TO BE OPTIMISTIC AND KEEP TS OUT. OTHER CONCERN IS STCU DEVELOPING OVERNIGHT FROM THE ISENTROPIC LIFT AND POSSIBLY PRODUCING SOME MVFR CIGS. CURRENT OBS SHOW STCU AROUND 6 KFT. SINCE MODELS SHOW DEEPER MOISTURE ALREADY BEHIND THE FRONT WITH RELATIVELY DRYER AIR ADVECTING NORTH...WILL KEEP CIGS VFR FOR NOW...EXCEPT FOR SOME MVFR CIGS WITHIN THE TS. && WOLTERS .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 200 AM MDT THU JUL 19 2007 .DISCUSSION...FORECAST CONCERNS ARE TEMPERATURES/PRECIPITATION AND LOW CIGS (AVIATION) IN THE SHORT TERM. .SHORT TERM (TODAY-SATURDAY NIGHT)... TODAY-TONIGHT...UPPER DISTURBANCE EMBEDDED WITHIN NEARLY NORTHERLY FLOW ALOFT CURRENTLY OVER WESTERN NEBRASKA WILL PUSH A COLD FRONT THROUGH THE AREA TODAY. WILL HAVE TO DEAL WITH STRATUS AND/OR SOME LOW CLOUDINESS MUCH OF THE DAY AS WELL AS GUSTY NORTHEAST POST FRONTAL WINDS. THIS WILL MAKE FOR A DIFFICULT TEMPERATURE FORECAST. PRECIPITATION FORECAST WILL BE DIFFICULT TOO. DESPITE LIMITED INHIBITION ACROSS PARTS OF THE AREA (DEPENDANT ON CLOUD COVER) AND SOME CAPE FORCING LOOKS TO BE ALONG THE FRONT WHICH WOULD FAVOR FAR SOUTHERN FORECAST AREA. WILL MAINTAIN SOME SLIGHT CHANCE POPS GENERALLY SOUTH OF THE INTERSTATE. FOR TONIGHT PROBLEM TURNS TO RETURN OF STRATUS. NAM/GFS/RUC13 ALL HAVE SATURATED BOUNDARY LAYER CONDITIONS OVER VARIOUS PARTS OF THE FORECAST AREA. FOR NOW HAVE STARTED WITH PREVIOUS FORECAST CLOUD GRIDS...ESP AFTER 06Z AND INCREASED THEM TO SOMEWHAT MIMIC THE RUC13 CEILING FORECAST. BASED ON 2M/MOS AND 850 TEMPERATURES WILL GO FOR MID 80S NORTH TO MID 90S SOUTH FOR HIGHS. FRIDAY-FRIDAY NIGHT...DAY WILL START OUT WITH CONSIDERABLE CLOUDINESS ACROSS THE EAST AND SOUTH...DISSIPATING SOMEWHAT DURING THE LATE AFTERNOON HOURS. NAM RESATURATES THE BOUNDARY LAYER SUGGESTING WIDESPREAD LOW CLOUDINESS FRIDAY NIGHT WHILE THE GFS IS MUCH LESS AGGRESSIVE. FOR NOW WILL GO WITH THE LESS AGGRESSIVE SOLUTION WHICH MATCHES UP BETTER WITH SURROUNDING OFFICES. WE HAVE THE NGM/NAM COOL TEMPERATURES AT 850 ANOTHER FEW DEGREES WHILE THE GFS/UKMET WARM THEM A FEW DEGREES. AVERAGING THEM AND THE 2M/MOS GUIDANCE NUMBERS PRODUCES A HIGH TEMP FORECAST VERY CLOSE TO CURRENTLY ADVERTISED ONE SO LITTLE CHANGE NEEDED RIGHT NOW. SATURDAY-SATURDAY NIGHT...GOOD AGREEMENT BETWEEN THE UKMET/GFS/NAM ON WARMING TEMPERATURES WITH 850 TEMPS SUPPORTING HIGHS AROUND 95 ACROSS THE AREA. .LONG TERM (SUNDAY-WEDNESDAY)... SUNDAY-MONDAY...LITTLE CHANGE AT 850MB SUNDAY WITH THE GFS/DGEX/ECWMF SHOWING +32C ACROSS THE WESTERN FORECAST TO +25C ACROSS THE EAST...SUPPORTING GENERALLY MID 90S WITH MAYBE SOME UPPER 90S ACROSS THE WEST. ON MONDAY THE 3 MODELS DO SHOW 850 TEMPS JUST A FEW DEGREES COOLER SO GIVEN THE CONSENSUS I BUMPED THEM DOWN JUST A FEW DEGREES WITH READINGS STILL IN THE MID 90S. && .AVIATION... CIGS BELOW 1K FEET WILL REACH THE KGLD TERMINAL AROUND 11Z AND CONTINUE THROUGH AT LEAST 18Z BEFORE BECOMING SCATTERED SHORTLY THEREAFTER. FOR THE KMCK AREA EXPECT THE LOW CIGS AROUND 12Z OR SO AND LASTING THROUGH AT LEAST 20Z OR SO. ANY SCT CIGS AROUND 1K THAT DEVELOP WILL BECOME BKN EARLY TONIGHT AS UPSLOPE FLOW CONTINUES. EXPECT CIGS BELOW 1K FT THROUGH 12Z FRIDAY. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ DDT/DDT/DDT ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 312 AM EDT FRI JUL 20 2007 .DISCUSSION... ARRIVAL OF AMPLIFIED UPR RDG FROM THE PLAINS AND BUILDING 5H HEIGHTS WILL RESULT IN DRY WEATHER AT LEAST THROUGH THE WEEKEND ALONG WITH A GRADUAL WARMING TREND. TODAY...POSITION OF SFC RDG AXIS TO THE W WILL RESULT IN A LIGHT NRLY FLOW ACROSS MUCH OF THE FCST AREA. 8H TEMPS OF 7-9C WILL RESULT IN INLAND HIGHS AROUND 70F WITH COOLER TEMPS(60S) FOR LAKE SUPERIOR SHORELINE AREAS. EXPECT A STEADY WARMING TREND THROUGH THE WEEKEND AS THE CENTER OF THE SFC HI IS PROGGED TO SLIDE INTO THE LOWER GREAT LAKES BY SUN AND SETUP A RETURN SW FLOW. H85 TEMPS ARE FCST TO INCREASE ABOUT 2C EACH DAY...FM 12-14C SAT TO 14-16C ON SUN. THE HI PRES CENTER WL BE CLOSE ENOUGH ON SAT TO ALLOW LK BREEZES TO FORM...BUT STRONGER SSW FLOW ON SUN WL TEND TO MINIMIZE LAKE INFLUENCE EXCEPT FOR AREAS DOWNSTREAM OF LAKE MI EAST OF KESC. KEPT GOING FCST HIGH TEMPS SLIGHTLY ABV MOS GUIDANCE WITH INLAND READINGS AROUND 80F ON SAT AND 80-85F ON SUN. THE 00Z GFS AND CANADIAN STILL SHOW HINT OF A WEAK SHORTWAVE MOVING THROUGH THE AMPLIFIED RDG ALONG WITH ASSOC WEAK SFC COLD FRONT APPROACHING INTO THE FCST AREA. ALTHOUGH IT WILL BE HARD FOR A SHORTWAVE TO BREAK DOWN SUCH AN AMPLIFIED RDG...DECIDED TO KEEP IN GOING SLIGHT CHC POPS FOR MON GIVEN THAT GFS/CANADIAN HAVE PERSISTED WITH THIS SOLN FOR LAST FEW RUNS. COORDINATED WITH GRB. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... SATELLITE IMAGERY AND RUC/NAM SFC-850 MB RH PROGS SUGGEST POTENTIAL FOR SOME SCT-BKN CLOUDS AT BOTH SITES. HOWEVER...EXPECT CIGS TO REMAIN IN THE VFR RANGE...GENERALLY 040-050. SCT-BKN CU MAY ALSO DEVELOP AGAIN LATER TODAY UNTIL THE 850 MB THERMAL TROF DEPARTS...LEAVING DRIER AIR...ACYC NRLY FLOW....AND CLEARING SKIES. NEVERTHELESS...VFR CONDITIONS SHOULD CONTINUE TO PREVAIL. && .MARINE (FOR 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... HIGH PRESSURE CONTINUES TO BUILD OVER THE UPPER LAKES THIS MORNING. THIS HIGH WILL STAY PUT OVER THE GREAT LAKES THROUGH THE WEEKEND. AFTER TODAY WITH LINGERING NW WINDS...EXPECT LIGHT S/SW WINDS WITH LK BREEZE COMPONENTS DEVELOPING SAT AND SUN AFTN. MAY BE A WEAK SFC TROUGH COME THROUGH MON NIGHT OR TUE...BUT CURRENT INDICATIONS SUGGEST MAIN WIND SHIFT COULD REMAIN TO THE NORTH OVER ONTARIO. FOR NOW...S/SW WINDS WELL BELOW 20 KT COVERS IT JUST FINE. && $$ PUBLIC...VOSS AVIATION...JLB MARINE...JLA mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 137 AM EDT FRI JUL 20 2007 UPDATED AVIATION DISCUSSION FOR 06Z TAFS .SYNOPSIS... WATER VAPOR IMAGERY AND RUC SHOWING A LONGWAVE TROUGH OVER EASTERN CANADA...A STEEP RIDGE OVER THE NORTHERN HIGH PLAINS AND THE CANADIAN PRAIRIES...AND ANOTHER LONGWAVE TROUGH OFF THE PACIFIC NORTHWEST. A SHORTWAVE ROTATING AROUND THE BASE OF THE EASTERN CANADIAN TROUGH IS MOVING THROUGH SOUTHEASTERN ONTARIO AND NORTHERN LOWER MICHIGAN. ANOTHER MUCH WEAKER SHORTWAVE SLIDING DOWN THE LEE OF THE RIDGE IS JUST NORTH OF THE MINNESOTA ARROWHEAD. SURFACE ANALYSIS SHOWING A LOW MOVING THROUGH THE LOWER GREAT LAKES DRAGGING A COLD FRONT THROUGH THE MIDDLE MISSISSIPPI AND NORTHERN OHIO RIVER VALLEYS. A HIGH BUILDING OVER SOUTHEAST MANITOBA AND WESTERN ONTARIO IS EXPANDING INTO THE FORECAST AREA. THE SHORTWAVE OVER THE FORECAST AREA IS PRODUCING SCATTERED SHOWERS AND THUNDERSTORMS OVER EASTERN ONTARIO AND EASTERN U.P. PRODUCING UPSLOPE CONDITIONS OFF OF LAKE SUPERIOR IS PRODUCE AREAS OF DRIZZLE AND LIGHT RAIN OVER THE HIGHER TERRAIN OF NORTH CENTRAL U.P. .SHORT TERM DISCUSSION (TNGT AND FRI)... THE SHORTWAVE OVER THE ARROWHEAD WILL CONTINUE TO HEAD SOUTHEAST INTO THE FORECAST AREA AS THE STRONGER SHORTWAVE SHIFTS INTO NORTHERN LOWER MICHIGAN THIS AFTERNOON. DRIER AIR WILL ADVECT INTO THE FORECAST AREA BY LATE EVENING. IN THE MEAN TIME...WARM AIR ADVECTION AROUND 800MB WILL PRODUCE AN INVERSION WHICH WILL MAKE A CAP LIMITING ANY THUNDERSTORMS DEVELOPMENT ESPECIALLY OVER THE WESTERN U.P. HOWEVER...THERE IS STILL ENOUGH MOISTURE PRESENT AND A STRONG ENOUGH CAP ENOUGH TO PREVENT PRECIPITATION. UPSLOPE OVER EASTERN LAKE SUPERIOR MAKE PRODUCE A SLIGHT OF RAIN OVER THE HIGH TERRAIN OF CENTRAL U.P. THIS EVENING. ALSO WILL KEEP A SLIGHT MENTION OF THUNDERSTORMS OVER LUCE COUNTY THROUGH EARLY EVENING. GFS SHOWING DRY AIR MOVING IN THIS EVENING. WINDS OUT OF THE NORTH TODAY PRODUCED SOME RIP CURRENT ON THE LAKE SUPERIOR BEACHES BETWEEN MARQUETTE AND GRAND MARAIS. THESE WILL DIMINISH TO A LIGHT RISK BY LATE EVENING AS WINDS AND WAVES DIE DOWN. THE LONGWAVE TROUGH WILL PUSH INTO WESTERN QUEBEC ON FRIDAY...WHILE THE CANADIAN PRAIRIE RIDGE WANDERS INTO MANITOBA. THE SURFACE HIGH WILL SETTLE OVER UPPER MICHIGAN ON FRIDAY. GRADIENTS WILL WEAKEN AND DRY AIR WILL ACCOMPANY THE HIGH. THUS WINDS WILL REMAIN LIGHT ON MONDAY. GFS FORECAST SOUNDINGS SUGGEST THAT FEW CUMULUS CLOUDS WILL DEVELOP OVER THE WESTERN U.P. BUT FOR THE MOST PART THE SKIES WILL BE MOSTLY SUNNY. .LONG TERM DISCUSSION (FRI NGT THRU THU)... FA FCST TO BE UNDER DOMINATION OF BLDG UPR HGTS IN THE FRI NGT THRU SUN PD UNDER SHARPENING UPR RDG ON THE SRN FLANK OF MAIN BAND OF WESTERLIES FCST TO SHIFT ACRS CNTRL CAN AND BTWN BUBBLE OF HOT AIR IN THE PLAINS AND TROF CUTTING OFF OVER THE E. FRI NGT SHOULD BE ON THE COOL SIDE WITH SFC HI PRES CENTER MOVING TO NRN LK MI BY 12Z SAT AND LGT WINDS OVER THE FA. GFS/NAM FCST SDNGS HINT SOME MID/HI CLD WL MOVE IN ESPECIALLY OVER THE E ON SRN FLANK OF BETTER WAD IN ONTARIO...BUT HARD TO IMAGINE ANY AC/CI WL BE THICK ENUF TO IMPACT DIURNAL TEMP DROP WITH RISING HGTS/SHARPENING RDG AXIS UPSTREAM. SO TENDED TOWARD THE LO END OF MOS GUIDANCE...ESPECIALLY OVER THE INTERIOR SCNTRL/E CLOSER TO WEAKER PRES GRADIENT THRU 12Z. THEN EXPECT A STEADY WARMING TREND THRU THE WEEKEND AS CENTER OF SFC HI PRES PROGGED TO DIP INTO THE LOWER LKS BY SUN AND SETUP A RETURN SW FLOW. H85 TEMPS FCST TO INCRS ABOUT 2C EACH DAY...FM ARND 10C ON FRI TO 14C ON SAT AND 16C ON SUN. HI PRES CENTER WL BE CLOSE ENUF ON SAT TO ALLOW LK BREEZES TO FORM...BUT STRONGER WSW FLOW ON SUN WL TEND TO MINIMIZE LK INFLUENCE EXCEPT DOWNSTREAM OF LK MI MAINLY E OF ESC. UPR RDG CENTERED OVER THE PLAINS AND ABV NORMAL TEMPS WL DOMINATE THE MEDIUM/EXTENDED PD WITH MAIN BELT OF WESTERLIES TO THE N IN CAN. HOWEVER...VARIOUS MODEL RUNS HINT AT A BACKDOOR COOL FROPA EARLY NXT WEEK WHEN GFS SHOWS H5 TEMPS DIPPING A BIT TO ARND -8C OR -9C IN MORE NLY ALF BTWN HI AMPLITUDE RDG/BUBBLE OF HOT AIR OVER THE PLAINS AND UPR TROF SOMEWHERE IN THE ERN CONUS. 12Z GFS/CNDN MODELS ALSO SHOW DISTURBANCE IMPACTING THE FA ON MON WITH FAIRLY IMPRESSIVE H85 THETA-E ADVCTN WHILE LOWER H5 TEMPS STILL IN PLACE. FOLLOWED NCEP LEAD AND INTRODUCED SCHC POPS FOR MON. FOLLOWING THE PASSAGE OF THIS SHRTWV...UPR RDG FCST TO BLD INTO THE UPR LKS. GIVEN HI HGTS/H5 TEMPS IN THE -6 TO -7C RANGE/CAPPING AT H85 WITH TEMPS IN THE 20-24C RANGE...SUSPECT ANY SHRA WL BE FEW AND FAR BTWN IN THE ABSENCE OF DYNAMICS AFT MON WITH LARGE MAJORITY OF GFS ENSEMBLE MEMBERS SHOWING HIER HGTS TOWARD MIDWEEK. WL GO WITH DRY FCST FOR TUE THRU NEXT THU. TENDED TOWARD THE HI END OF GFS MOS GUIDANCE AFT MON FOR MAX TEMPS FCST GIVEN THE HI H85 TEMPS EXPECTED UNDER THE RDG AND WSW FLOW THAT WL MINIMIZE LK MODERATION. COORDINATED WITH APX/GRB/DLH. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... SATELLITE IMAGERY AND RUC/NAM SFC-850 MB RH PROGS SUGGEST POTENTIAL FOR SOME SCT-BKN CLOUDS AT BOTH SITES. HOWEVER...EXPECT CIGS TO REMAIN IN THE VFR RANGE...GENERALLY 040-050. SCT-BKN CU MAY ALSO DEVELOP AGAIN LATER TODAY UNTIL THE 850 MB THERMAL TROF DEPARTS AND DRIER AIR MOVES IN WITH ACYC NRLY FLOW. BY LATE AFTN...EXPECT CLEARING SKIES IN THE MID TO LATE AFTERNOON. NEVERTHELESS...VFR CONDITIONS SHOULD CONTINUE TO PREVAIL. && .MARINE (FOR 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... HIGH PRESSURE BUILDING OVER LAKE SUPERIOR WILL KEEP THE GRADIENTS LIGHT AND WINDS OUT OF THE NORTH. AS THE HIGH PUSHES EAST ON SATURDAY WINDS WILL BACK TO THE SOUTH. A COLD FRONT WILL PUSH THROUGH THE AREA MONDAY NIGHT WHILE ANOTHER HIGH BUILDS OVER SOUTH CENTRAL CANADA. && $$ AVIATION...JLB MARINE...DLG SHORT TERM DISCUSSION...DLG LONG TERM DISCUSSION...KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 740 PM EDT THU JUL 19 2007 .SYNOPSIS... WATER VAPOR IMAGERY AND RUC SHOWING A LONGWAVE TROUGH OVER EASTERN CANADA...A STEEP RIDGE OVER THE NORTHERN HIGH PLAINS AND THE CANADIAN PRAIRIES...AND ANOTHER LONGWAVE TROUGH OFF THE PACIFIC NORTHWEST. A SHORTWAVE ROTATING AROUND THE BASE OF THE EASTERN CANADIAN TROUGH IS MOVING THROUGH SOUTHEASTERN ONTARIO AND NORTHERN LOWER MICHIGAN. ANOTHER MUCH WEAKER SHORTWAVE SLIDING DOWN THE LEE OF THE RIDGE IS JUST NORTH OF THE MINNESOTA ARROWHEAD. SURFACE ANALYSIS SHOWING A LOW MOVING THROUGH THE LOWER GREAT LAKES DRAGGING A COLD FRONT THROUGH THE MIDDLE MISSISSIPPI AND NORTHERN OHIO RIVER VALLEYS. A HIGH BUILDING OVER SOUTHEAST MANITOBA AND WESTERN ONTARIO IS EXPANDING INTO THE FORECAST AREA. THE SHORTWAVE OVER THE FORECAST AREA IS PRODUCING SCATTERED SHOWERS AND THUNDERSTORMS OVER EASTERN ONTARIO AND EASTERN U.P. PRODUCING UPSLOPE CONDITIONS OFF OF LAKE SUPERIOR IS PRODUCE AREAS OF DRIZZLE AND LIGHT RAIN OVER THE HIGHER TERRAIN OF NORTH CENTRAL U.P. .SHORT TERM DISCUSSION (TNGT AND FRI)... THE SHORTWAVE OVER THE ARROWHEAD WILL CONTINUE TO HEAD SOUTHEAST INTO THE FORECAST AREA AS THE STRONGER SHORTWAVE SHIFTS INTO NORTHERN LOWER MICHIGAN THIS AFTERNOON. DRIER AIR WILL ADVECT INTO THE FORECAST AREA BY LATE EVENING. IN THE MEAN TIME...WARM AIR ADVECTION AROUND 800MB WILL PRODUCE AN INVERSION WHICH WILL MAKE A CAP LIMITING ANY THUNDERSTORMS DEVELOPMENT ESPECIALLY OVER THE WESTERN U.P. HOWEVER...THERE IS STILL ENOUGH MOISTURE PRESENT AND A STRONG ENOUGH CAP ENOUGH TO PREVENT PRECIPITATION. UPSLOPE OVER EASTERN LAKE SUPERIOR MAKE PRODUCE A SLIGHT OF RAIN OVER THE HIGH TERRAIN OF CENTRAL U.P. THIS EVENING. ALSO WILL KEEP A SLIGHT MENTION OF THUNDERSTORMS OVER LUCE COUNTY THROUGH EARLY EVENING. GFS SHOWING DRY AIR MOVING IN THIS EVENING. WINDS OUT OF THE NORTH TODAY PRODUCED SOME RIP CURRENT ON THE LAKE SUPERIOR BEACHES BETWEEN MARQUETTE AND GRAND MARAIS. THESE WILL DIMINISH TO A LIGHT RISK BY LATE EVENING AS WINDS AND WAVES DIE DOWN. THE LONGWAVE TROUGH WILL PUSH INTO WESTERN QUEBEC ON FRIDAY...WHILE THE CANADIAN PRAIRIE RIDGE WANDERS INTO MANITOBA. THE SURFACE HIGH WILL SETTLE OVER UPPER MICHIGAN ON FRIDAY. GRADIENTS WILL WEAKEN AND DRY AIR WILL ACCOMPANY THE HIGH. THUS WINDS WILL REMAIN LIGHT ON MONDAY. GFS FORECAST SOUNDINGS SUGGEST THAT FEW CUMULUS CLOUDS WILL DEVELOP OVER THE WESTERN U.P. BUT FOR THE MOST PART THE SKIES WILL BE MOSTLY SUNNY. .LONG TERM DISCUSSION (FRI NGT THRU THU)... FA FCST TO BE UNDER DOMINATION OF BLDG UPR HGTS IN THE FRI NGT THRU SUN PD UNDER SHARPENING UPR RDG ON THE SRN FLANK OF MAIN BAND OF WESTERLIES FCST TO SHIFT ACRS CNTRL CAN AND BTWN BUBBLE OF HOT AIR IN THE PLAINS AND TROF CUTTING OFF OVER THE E. FRI NGT SHOULD BE ON THE COOL SIDE WITH SFC HI PRES CENTER MOVING TO NRN LK MI BY 12Z SAT AND LGT WINDS OVER THE FA. GFS/NAM FCST SDNGS HINT SOME MID/HI CLD WL MOVE IN ESPECIALLY OVER THE E ON SRN FLANK OF BETTER WAD IN ONTARIO...BUT HARD TO IMAGINE ANY AC/CI WL BE THICK ENUF TO IMPACT DIURNAL TEMP DROP WITH RISING HGTS/SHARPENING RDG AXIS UPSTREAM. SO TENDED TOWARD THE LO END OF MOS GUIDANCE...ESPECIALLY OVER THE INTERIOR SCNTRL/E CLOSER TO WEAKER PRES GRADIENT THRU 12Z. THEN EXPECT A STEADY WARMING TREND THRU THE WEEKEND AS CENTER OF SFC HI PRES PROGGED TO DIP INTO THE LOWER LKS BY SUN AND SETUP A RETURN SW FLOW. H85 TEMPS FCST TO INCRS ABOUT 2C EACH DAY...FM ARND 10C ON FRI TO 14C ON SAT AND 16C ON SUN. HI PRES CENTER WL BE CLOSE ENUF ON SAT TO ALLOW LK BREEZES TO FORM...BUT STRONGER WSW FLOW ON SUN WL TEND TO MINIMIZE LK INFLUENCE EXCEPT DOWNSTREAM OF LK MI MAINLY E OF ESC. UPR RDG CENTERED OVER THE PLAINS AND ABV NORMAL TEMPS WL DOMINATE THE MEDIUM/EXTENDED PD WITH MAIN BELT OF WESTERLIES TO THE N IN CAN. HOWEVER...VARIOUS MODEL RUNS HINT AT A BACKDOOR COOL FROPA EARLY NXT WEEK WHEN GFS SHOWS H5 TEMPS DIPPING A BIT TO ARND -8C OR -9C IN MORE NLY ALF BTWN HI AMPLITUDE RDG/BUBBLE OF HOT AIR OVER THE PLAINS AND UPR TROF SOMEWHERE IN THE ERN CONUS. 12Z GFS/CNDN MODELS ALSO SHOW DISTURBANCE IMPACTING THE FA ON MON WITH FAIRLY IMPRESSIVE H85 THETA-E ADVCTN WHILE LOWER H5 TEMPS STILL IN PLACE. FOLLOWED NCEP LEAD AND INTRODUCED SCHC POPS FOR MON. FOLLOWING THE PASSAGE OF THIS SHRTWV...UPR RDG FCST TO BLD INTO THE UPR LKS. GIVEN HI HGTS/H5 TEMPS IN THE -6 TO -7C RANGE/CAPPING AT H85 WITH TEMPS IN THE 20-24C RANGE...SUSPECT ANY SHRA WL BE FEW AND FAR BTWN IN THE ABSENCE OF DYNAMICS AFT MON WITH LARGE MAJORITY OF GFS ENSEMBLE MEMBERS SHOWING HIER HGTS TOWARD MIDWEEK. WL GO WITH DRY FCST FOR TUE THRU NEXT THU. TENDED TOWARD THE HI END OF GFS MOS GUIDANCE AFT MON FOR MAX TEMPS FCST GIVEN THE HI H85 TEMPS EXPECTED UNDER THE RDG AND WSW FLOW THAT WL MINIMIZE LK MODERATION. COORDINATED WITH APX/GRB/DLH. && .AVIATION (FOR THE 00Z TAF ISSUANCE)... EVEN THOUGH THE BEST SFC-850 MB DRY ADVECTION WILL HOLD OFF UNTIL MIDDAY FRI...EXPECT THAT WITH THE LOSS OF DIURNAL HEATING NO MORE THAN SCT CLOUDS THIS EVENING ARE EXPECTED. SOME INLAND DIURNAL CU MAY DEVELOP FRI. OTHERWISE...VFR CONDITIONS SHOULD PERSIST. && .MARINE (FOR 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... HIGH PRESSURE BUILDING OVER LAKE SUPERIOR WILL KEEP THE GRADIENTS LIGHT AND WINDS OUT OF THE NORTH. AS THE HIGH PUSHES EAST ON SATURDAY WILL WINDS WILL BACK TO THE SOUTH. A COLD FRONT WILL PUSH THROUGH THE AREA MONDAY NIGHT BY ANOTHER HIGH BUILDING OVER SOUTH CENTRAL CANADA. && $$ AVIATION...JLB MARINE...DLG SHORT TERM DISCUSSION...DLG LONG TERM DISCUSSION...KC mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 147 PM EDT THU JUL 19 2007 .DISCUSSION... WATER VAPOR IMAGERY AND RUC SHOWING A LONGWAVE TROUGH OVER EASTERN CANADA...A STEEP RIDGE OVER THE NORTHERN HIGH PLAINS AND THE CANADIAN PRAIRIES...AND ANOTHER LONGWAVE TROUGH OFF THE PACIFIC NORTHWEST. A SHORTWAVE ROTATING TO THE EASTERN CANADIAN TROUGH IS MOVE THROUGH EASTERN ONTARIO AND THE U.P. ANOTHER WEAKER SHORTWAVE SLIDING DOWN THE LEE OF THE RIDGE IS OVER WESTERN ONTARIO. SURFACE ANALYSIS SHOWING A LOW MOVING THROUGH THE LOWER GREAT LAKES DRAGGING A COLD FRONT THROUGH THE MIDDLE MISSISSIPPI RIVER VALLEY. A HIGH BUILDING OVER THE SOUTHERN MANITOBA AND WESTERN ONTARIO IS EXPANDING INTO THE FORECAST AREA. THE SHORTWAVE OVER THE FORECAST AREA IS PRODUCING SCATTERED SHOWERS AND THUNDERSTORMS OVER EASTERN ONTARIO AND EASTERN U.P. THE SHORTWAVE OVER THE FORECAST AREA WILL CONTINUE TO HEAD SOUTHEAST INTO NORTHERN LOWER MICHIGAN THIS AFTERNOON...WHILE THE WEAKER SHORTWAVE OVER WESTERN ONTARIO SHIFT INTO THE ARROWHEAD OF MINNESOTA. DRIER AIR WILL ADVECT INTO THE FORECAST AREA THIS MORNING AND EARLY AFTERNOON. IN THE MEAN TIME...WARM AIR ADVECTION AROUND 800MB WILL PRODUCE AN INVERSION WHICH WILL CAP THE ANY DEVELOPMENT ALSO... ESPECIALLY OVER THE WESTERN U.P. THERE IS STILL ENOUGH MOISTURE PRESENT AND CAP STRONG ENOUGH TO PREVENT PRECIPITATION OF THE EAST SO WILL KEEP A SLIGHT MENTION IN THE EAST THROUGH THE AFTERNOON. FOR TEMPERATURES...GOING HIGHS LOOKED REASONABLE WITH TEMPS MOSTLY IN THE 60S WITH LOW 70S ACROSS THE SOUTH AWAY FROM THE LAKE. TONIGHT ONWARDS...QUIET WEATHER TAKES OVER AND WITH LIGHT WINDS AND CLEAR SKIES...IDEAL RADIATIONAL COOLING CONDITIONS OCCUR AND UNDERCUT GUIDANCE A BIT IN THE WEST AND CENTRAL. FOR TEMPERATURES...WENT CLOSE TO ADJMRF TEMPS AND MIXED 850 MB TEMPS DOWN TO THE SFC WHICH SEEMED REASONABLE. OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... UPSLOPE CONDITIONS OFF OF LAKE SUPERIOR WILL CONTINUE TO CAUSE LOW CEILING THIS AFTERNOON OVER NORTHERN PART OF THE U.P. ISOLATED SHOWERS AND THUNDERSTORMS WILL CONTINUE OVER THE EASTERN U.P. DUE THE PRESENCE OF THE WEAK SHORTWAVE AS MENTIONED ABOVE. DRIER AIR WILL ADVECT INTO THE AREA THIS EVENING AND SHOULD CLEAR MOST OF THE LOW CLOUDS OUT. A CAP AROUND 800MB WILL KEEP THE THUNDERSTORMS FROM DEVELOPING. STEEP LAPSE RATES AT THE LOW LEVELS WILL PRODUCE LOW CLOUDS IN LATE TONIGHT AND FRIDAY MORNING. && .MARINE (FOR 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... PRESSURE FIELD IS INITIALLY DISORGANIZED THIS MORNING BUT TIGHTENS QUICKLY AS LOW PRESSURE OVER GREAT LAKES STRENGTHENS AND HIGH PRESSURE OVER CANADA BUILDS SE. COLD AIR ADVECTION AND THE TIGHT GRADIENT LEADS TO 20-30KT WINDS OVR MOST OF LK SUPERIOR TODAY. FAR WESTERN LK SUPERIOR NOT SEEING AS MUCH COLD AIR ADVECTION SO IT IS MORE STABLE AND SO EXPECT LIGHTER WINDS WEST OF THE KEWEENAW PENINSULA TOWARD THE MN SHORELINE. AFTER THIS EVENING...EXPECT WINDS TO REMAIN BELOW 20 KT THROUGH EARLY NEXT WEEK. && $$ AVIATION/MARINE...JLA DISCUSSION...DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPRINGFIELD MO 1130 PM CDT THU JUL 19 2007 .UPDATE... SCATTERED TO BROKEN CONVECTION CONTINUED ALONG A DIFFUSE SURFACE BOUNDARY AND 850 MB CONVERGENCE AXIS FROM EAST CENTRAL KANSAS TO SOUTH CENTRAL MISSOURI. THIS AXIS ALONG WITH THE SCATTERED CONVECTION WILL SAG SOUTHWARD OVERNIGHT. RUC AND WRF MODELS DEPICT THE ACTIVITY DIMINISHING OVERNIGHT BUT FEEL THAT AMPLE CONVERGENCE AND ELEVATED INSTABILITY WILL MAINTAIN THE CONVECTION OVERNIGHT. FOSTER && .DISCUSSION... CHALLENGES CONTINUE TO BE ASSOCIATED WITH A SLOW MOVING COLD FRONT MOVING SOUTH FROM NORTHERN MISSOURI. COOLER THAN NORMAL TEMPS ARE EXPECTED OVER THE WEEKEND. CURRENTLY...SLOW MOVING COLD FRONT NOW FROM CENTRAL ILLINOIS TO KANSAS CITY...EXTENDING SOUTHWESTWARD INTO SOUTHWEST KANSAS. ESTIMATED TIME OF ARRIVAL INTO CENTRAL MISSOURI LOOKS TO BE AROUND 4-5 PM...INTO SOUTHERN MISSOURI 10-11 PM THIS EVENING. CURRENT AREA RADAR STILL SHOWS CWA ECHO FREE...BUT STARTING TO SEE A SOUTHWARD PROGRESSION ON AREA OF SHOWERS UP IN NORTHERN MISSOURI. 18Z SGF SOUNDING SHOWING TWO STRONG CAPS OVER THE AREA...ONE NEAR 863MBS...THE OTHER NEAR 655MBS. SO FOR AT LEAST THE EARLY PART OF THE AFTERNOON...WE SHOULD REMAIN DRY. TONIGHT...GFS BEGINS TO COOL DOWN MID LEVELS AROUND 00Z WITH 700MB TEMPS DROPPING FROM +10C TO +8C. THIS SHOULD HELP BREAK THE UPPER CAP AND GET CONVECTION GOING DOWN IN THIS AREA. FRONT SHOULD BE MOVING INTO CENTRAL MISSOURI BY THAT TIME AS WELL. WRF SOUNDING REALLY BECOMES UNSTABLE AFTER 03Z THIS EVENING. WOULD EXPECT THIS WOULD BE THE TIMEFRAME WHEN CONVECTION REALLY STARTS GOING. BY 06Z...CONVECTIVE INHIBITION TOTALLY GONE WITH CAPES AROUND 1200-1500 J/KG. WILL NEED TO WATCH NORTHEASTERN KANSAS EARLY IN THE EVENING TO SEE WHAT CONVECTION GETS GOING IN THAT AREA. MODELS SHOWING STRONGEST CONVERGENCE THIS AREA. MAY SEE MCS FORM THERE AND THEN MOVE SOUTHEAST INTO WESTERN MISSOURI. FRIDAY TO SATURDAY...FRONT DOWN NEAR THE MISSOURI/ARKANSAS FRIDAY MORNING. 925MB STREAMLINES SHOWING DIFFLUENT FLOW OVER MOST OF THE CWA. KEPT CHANCE POPS GOING FOR THE MORNING AND EARLY AFTERNOON TIMEFRAME ACROSS SOUTHERN MISSOURI IN THE EVENT THE FRONT HANGS UP. BY FRIDAY EVENING...GFS SHOWING SURFACE WAVE ACROSS SOUTHWEST MISSOURI WITH SIGNIFICANT PRECIP OVER THIS AREA. WRF ON THE OTHER HAND...CONTINUES TO PUSH FRONT PROGRESSIVELY SOUTH. TENDED MORE TOWARDS THE WRF SOLUTION AS GFS HAS BEEN REALLY AFFECTED BY CONVECTIVE FEEDBACK ISSUES. EXTENDED...SUNDAY THROUGH THURSDAY. NO MAJOR CHANGES IN THE EXTENDED PERIOD WITH THE UPPER RIDGE ACROSS THE ROCKIES EXPECTING TO BUILD ACROSS THE CENTRAL PLAINS...AND ACROSS THE UPPER MIDWEST/NORTHERN PLAINS BY EARLY NEXT WEEK. THIS WILL KEEP THE HOTTEST AIRMASS NORTH OF OUR REGION...BUT STILL REMAINING SEASONABLE WITH HIGHS RISING BACK TO NEAR 90 DEGREES BY SUNDAY/MONDAY...AND CONTINUING THROUGH THURSDAY. HEAT INDICES WILL ALSO SLOWLY RISE BY MIDWEEK AS THE AIR MASS SLOWLY MODIFIES ACROSS THE MID MISSISSIPPI VALLY REGION. ONLY FORECAST PROBLEM IS A WEAKNESS IN THE HEIGHT FIELDS ACROSS THE SOUTHEAST U.S. AND SPREADING WESTWARD ACROSS THE SOUTHERN MISSISSIPPI VALLEY. THIS WEAKNESS WILL ALLOW FOR MORE UNSETTLED CONDITIONS TO DEVELOP AND PROVIDE A FOCUS FOR THUNDERSTORMS BY NEXT THURSDAY. THERE NEEDS TO BE MORE CONSISTENCY IN THE MODEL RUNS FOR THE NEXT SEVERAL DAYS BEFORE ANY TYPE OF WIDESPREAD PRECIPITATION LOOKS REASONABLE LATE NEXT WEEK. JLT && .AVIATION... SCATTERED SHOWERS AND THUNDERSTORMS WILL AFFECT THE JOPLIN AND SPRINGFIELD TERMINAL VICINITIES OVERNIGHT AS A WEAK FRONT SAGS SOUTHWARD INTO THE OZARKS. LOCALIZED MVFR CONDITIONS WILL BE POSSIBLE IN THE SHOWERS. SOME PATCHY LIGHT FOG WILL ALSO BE POSSIBLE AROUND SUNRISE. THE POSSIBILITY OF THUNDERSTORMS WILL PERSIST INTO FRIDAY MORNING AT THE SPRINGFIELD TERMINAL AND MUCH OF THE DAY FRIDAY AT JOPLIN. HOWEVER VFR CONDITIONS WILL BE THE RULE. FOSTER && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ WFO SGF mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HASTINGS NE 1208 PM CDT FRI JUL 20 2007 .AVIATION...PERIODS OF MVFR CONDITIONS EXPECTED AT THE KGRI TERMINAL THROUGH THE NEXT 24 HOURS. CEILINGS ARE FINALLY BEGINNING TO LIFT THUS ALLOWING FOR PREVAILING VFR CONDITIONS. PERIODIC MVFR CONDITIONS STILL REMAIN POSSIBLE HOWEVER THROUGH 21Z. VFR CONDITIONS SHOULD THEN CONTINUE UNINTERRUPTED THROUGH EARLY MORNING SATURDAY. STRATUS WILL ACCOMPANY PATCHY FOG SATURDAY MORNING...WITH MVFR CONDITIONS ONCE AGAIN POSSIBLE BETWEEN 09Z AND 13Z. SURFACE WINDS WILL GENERALLY REMAIN OUT OF THE SOUTHEAST THROUGH THE FORECAST PERIOD. && .PREV DISCUSSION... /ISSUED 1142 AM CDT FRI JUL 20 2007/ UPDATE...UPDATED FORECAST TO REMOVE MORNING WORDING. NO OTHER CHANGES MADE. PREV DISCUSSION... /ISSUED 944 AM CDT FRI JUL 20 2007/ UPDATE...MORNING SHOWERS AND THUNDERSTORMS ACROSS OUR KANSAS COUNTIES HAVE DIMINISHED FOR THE MOST PART. MORNING ANALYSIS CONTINUES TO INDICATE AN ELEVATED BOUNDARY NEAR THE AREA...WITH WEAK ISENTROPIC LIFT NEAR THE 310K SURFACE ALSO PRESENT. LATEST RUC GUIDANCE INDICATES ISENTROPIC LIFT ALONG THIS SAME SURFACE MAY INCREASE LATER THIS AFTERNOON ACROSS OUR KANSAS COUNTIES AND PERHAPS PORTIONS OF OUR EXTREME SOUTHERN NEBRASKA COUNTIES. AS A RESULT...HAVE GONE AHEAD AND INSERTED SLIGHT CHANCE POPS FOR OUR KANSAS COUNTIES AND FROM HARLAN COUNTY EASTWARD THROUGH THIS AFTERNOON. ALSO TWEAKED SKY COVER A BIT. REST OF THE FORECAST REMAIN ON TRACK WITH NO OTHER CHANGES MADE. PREV DISCUSSION... /ISSUED 357 AM CDT FRI JUL 20 2007/ DISCUSSION...LATEST WATER VAPOR IMAGERY REVEALS A HIGHLY AMPLIFIED PATTERN WITH A LARGE RIDGE ACROSS THE CENTRAL CONUS AND A TROUGH OVER THE GREAT LAKES AND THE WEST COAST. ALTHOUGH MOST OF THE PLAINS IS SEEING MID AND UPPER LEVEL HEIGHT RISES...SEVERAL SMALL BUT POTENT SHORT WAVES ARE SEEN UNDER THIS RIDGE. ONE OF THESE WAVES HAS BEEN INTERACTING WITH THE 850MB FRONT ACROSS NORTH CENTRAL KANSAS WITH ISOLATED TO SCATTERED CONVECTION SEEN ACROSS THIS AREA. WITH PW VALUES AROUND 150 PERCENT OF NORMAL...THIS CONVECTION HAS BEEN PRODUCING SOME DECENT RAINFALL AMOUNTS WITH RATES OVER ONE INCH PER HOUR. RECENT OBJECTIVE SURFACE ANALYSIS SHOWS A NEARLY STALLED FRONT SITTING ACROSS SOUTHERN AND CENTRAL KANSAS WITH SLIGHTLY DRIER AIR SITTING ACROSS NEBRASKA. THE WEATHER PATTERN WILL CHANGE LITTLE TODAY AS THE LARGE UPPER RIDGE WILL BECOME ANCHORED ACROSS THE PLAINS AND ROCKIES WHILE THE AFOREMENTIONED FRONT REMAINS STALLED ACROSS SOUTHERN KANSAS. THE WAVE RESPONSIBLE FOR KICKING OFF THE ELEVATED CONVECTION ACROSS NORTH CENTRAL KANSAS IS SHOWN TO GRADUALLY DRIFT TO THE SOUTH THROUGH THE DAY. HOWEVER...STILL EXPECT AT LEAST SOME ISOLATED CONVECTION TO IMPACT MAINLY NORTH CENTRAL KANSAS THROUGH EARLY AFTERNOON AS THE MODELS SHOW DECENT LOW LEVEL CAPE DEVELOPING ACROSS THIS AREA. HIGH TEMPERATURES WILL BE TRICKY TODAY GIVEN PLENTY OF CLOUD COVER AROUND...BUT WILL AIM FOR HIGHS IN THE LOWER 80S NEAR ORD...TO THE MID TO UPPER 80S ACROSS NORTH CENTRAL KANSAS. HOT AND DRY PATTERN THEN LOOKS TO TAKE HOLD OF THE REGION FOR THE WEEKEND AS THE UPPER RIDGE SITS OVER THE PLAINS AND ROCKIES. PRESSURE FALLS ACROSS THE NORTHERN HIGH PLAINS WILL HELP TO GRADUALLY DEEPEN THE LEE TROUGH INTO EASTERN COLORADO AND IN THE PROCESS LIFTING THE STALLED OUT FRONT NORTHEAST OF THE AREA. THIS WILL SET THE STAGE FOR HIGHS IN THE UPPER 80S TO MID 90S THIS WEEKEND. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SB ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HASTINGS NE 1142 AM CDT FRI JUL 20 2007 .UPDATE...UPDATED FORECAST TO REMOVE MORNING WORDING. NO OTHER CHANGES MADE. && .PREV DISCUSSION... /ISSUED 944 AM CDT FRI JUL 20 2007/ UPDATE...MORNING SHOWERS AND THUNDERSTORMS ACROSS OUR KANSAS COUNTIES HAVE DIMINISHED FOR THE MOST PART. MORNING ANALYSIS CONTINUES TO INDICATE AN ELEVATED BOUNDARY NEAR THE AREA...WITH WEAK ISENTROPIC LIFT NEAR THE 310K SURFACE ALSO PRESENT. LATEST RUC GUIDANCE INDICATES ISENTROPIC LIFT ALONG THIS SAME SURFACE MAY INCREASE LATER THIS AFTERNOON ACROSS OUR KANSAS COUNTIES AND PERHAPS PORTIONS OF OUR EXTREME SOUTHERN NEBRASKA COUNTIES. AS A RESULT...HAVE GONE AHEAD AND INSERTED SLIGHT CHANCE POPS FOR OUR KANSAS COUNTIES AND FROM HARLAN COUNTY EASTWARD THROUGH THIS AFTERNOON. ALSO TWEAKED SKY COVER A BIT. REST OF THE FORECAST REMAIN ON TRACK WITH NO OTHER CHANGES MADE. PREV DISCUSSION... /ISSUED 622 AM CDT FRI JUL 20 2007/ AVIATION...IMMEDIATE CONCERN REVOLVES AROUND STRATUS DECK AND WHETHER IT WILL GET INTO GRI OR NOT. BELIEVE IT WILL GIVING SATELLITE AND VISUAL OBS. FOG WILL NOT BE A PROBLEM TODAY AS DRIER AIR AT SURFACE ADVECTED IN OVERNIGHT KEEPING VSBYS UP. SHOULD SEE SOME CLEARING THIS AFTERNOON...AT LEAST FROM BKN TO SCT...BUT PLENTY OF LOW LEVEL MOISTURE SO WON`T GO CLEAR. OTHER CONCERN IS POSSIBLE FOG BEFORE SUNRISE ON SATURDAY BUT WON`T ADD MENTION INTO TAF AT THIS TIME. PREV DISCUSSION... /ISSUED 357 AM CDT FRI JUL 20 2007/ DISCUSSION...LATEST WATER VAPOR IMAGERY REVEALS A HIGHLY AMPLIFIED PATTERN WITH A LARGE RIDGE ACROSS THE CENTRAL CONUS AND A TROUGH OVER THE GREAT LAKES AND THE WEST COAST. ALTHOUGH MOST OF THE PLAINS IS SEEING MID AND UPPER LEVEL HEIGHT RISES...SEVERAL SMALL BUT POTENT SHORT WAVES ARE SEEN UNDER THIS RIDGE. ONE OF THESE WAVES HAS BEEN INTERACTING WITH THE 850MB FRONT ACROSS NORTH CENTRAL KANSAS WITH ISOLATED TO SCATTERED CONVECTION SEEN ACROSS THIS AREA. WITH PW VALUES AROUND 150 PERCENT OF NORMAL...THIS CONVECTION HAS BEEN PRODUCING SOME DECENT RAINFALL AMOUNTS WITH RATES OVER ONE INCH PER HOUR. RECENT OBJECTIVE SURFACE ANALYSIS SHOWS A NEARLY STALLED FRONT SITTING ACROSS SOUTHERN AND CENTRAL KANSAS WITH SLIGHTLY DRIER AIR SITTING ACROSS NEBRASKA. THE WEATHER PATTERN WILL CHANGE LITTLE TODAY AS THE LARGE UPPER RIDGE WILL BECOME ANCHORED ACROSS THE PLAINS AND ROCKIES WHILE THE AFOREMENTIONED FRONT REMAINS STALLED ACROSS SOUTHERN KANSAS. THE WAVE RESPONSIBLE FOR KICKING OFF THE ELEVATED CONVECTION ACROSS NORTH CENTRAL KANSAS IS SHOWN TO GRADUALLY DRIFT TO THE SOUTH THROUGH THE DAY. HOWEVER...STILL EXPECT AT LEAST SOME ISOLATED CONVECTION TO IMPACT MAINLY NORTH CENTRAL KANSAS THROUGH EARLY AFTERNOON AS THE MODELS SHOW DECENT LOW LEVEL CAPE DEVELOPING ACROSS THIS AREA. HIGH TEMPERATURES WILL BE TRICKY TODAY GIVEN PLENTY OF CLOUD COVER AROUND...BUT WILL AIM FOR HIGHS IN THE LOWER 80S NEAR ORD...TO THE MID TO UPPER 80S ACROSS NORTH CENTRAL KANSAS. HOT AND DRY PATTERN THEN LOOKS TO TAKE HOLD OF THE REGION FOR THE WEEKEND AS THE UPPER RIDGE SITS OVER THE PLAINS AND ROCKIES. PRESSURE FALLS ACROSS THE NORTHERN HIGH PLAINS WILL HELP TO GRADUALLY DEEPEN THE LEE TROUGH INTO EASTERN COLORADO AND IN THE PROCESS LIFTING THE STALLED OUT FRONT NORTHEAST OF THE AREA. THIS WILL SET THE STAGE FOR HIGHS IN THE UPPER 80S TO MID 90S THIS WEEKEND. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SB ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HASTINGS NE 944 AM CDT FRI JUL 20 2007 .UPDATE...MORNING SHOWERS AND THUNDERSTORMS ACROSS OUR KANSAS COUNTIES HAVE DIMINISHED FOR THE MOST PART. MORNING ANALYSIS CONTINUES TO INDICATE AN ELEVATED BOUNDARY NEAR THE AREA...WITH WEAK ISENTROPIC LIFT NEAR THE 310K SURFACE ALSO PRESENT. LATEST RUC GUIDANCE INDICATES ISENTROPIC LIFT ALONG THIS SAME SURFACE MAY INCREASE LATER THIS AFTERNOON ACROSS OUR KANSAS COUNTIES AND PERHAPS PORTIONS OF OUR EXTREME SOUTHERN NEBRASKA COUNTIES. AS A RESULT...HAVE GONE AHEAD AND INSERTED SLIGHT CHANCE POPS FOR OUR KANSAS COUNTIES AND FROM HARLAN COUNTY EASTWARD THROUGH THIS AFTERNOON. ALSO TWEAKED SKY COVER A BIT. REST OF THE FORECAST REMAIN ON TRACK WITH NO OTHER CHANGES MADE. && .PREV DISCUSSION... /ISSUED 622 AM CDT FRI JUL 20 2007/ AVIATION...IMMEDIATE CONCERN REVOLVES AROUND STRATUS DECK AND WHETHER IT WILL GET INTO GRI OR NOT. BELIEVE IT WILL GIVING SATELLITE AND VISUAL OBS. FOG WILL NOT BE A PROBLEM TODAY AS DRIER AIR AT SURFACE ADVECTED IN OVERNIGHT KEEPING VSBYS UP. SHOULD SEE SOME CLEARING THIS AFTERNOON...AT LEAST FROM BKN TO SCT...BUT PLENTY OF LOW LEVEL MOISTURE SO WON`T GO CLEAR. OTHER CONCERN IS POSSIBLE FOG BEFORE SUNRISE ON SATURDAY BUT WON`T ADD MENTION INTO TAF AT THIS TIME. PREV DISCUSSION... /ISSUED 357 AM CDT FRI JUL 20 2007/ DISCUSSION...LATEST WATER VAPOR IMAGERY REVEALS A HIGHLY AMPLIFIED PATTERN WITH A LARGE RIDGE ACROSS THE CENTRAL CONUS AND A TROUGH OVER THE GREAT LAKES AND THE WEST COAST. ALTHOUGH MOST OF THE PLAINS IS SEEING MID AND UPPER LEVEL HEIGHT RISES...SEVERAL SMALL BUT POTENT SHORT WAVES ARE SEEN UNDER THIS RIDGE. ONE OF THESE WAVES HAS BEEN INTERACTING WITH THE 850MB FRONT ACROSS NORTH CENTRAL KANSAS WITH ISOLATED TO SCATTERED CONVECTION SEEN ACROSS THIS AREA. WITH PW VALUES AROUND 150 PERCENT OF NORMAL...THIS CONVECTION HAS BEEN PRODUCING SOME DECENT RAINFALL AMOUNTS WITH RATES OVER ONE INCH PER HOUR. RECENT OBJECTIVE SURFACE ANALYSIS SHOWS A NEARLY STALLED FRONT SITTING ACROSS SOUTHERN AND CENTRAL KANSAS WITH SLIGHTLY DRIER AIR SITTING ACROSS NEBRASKA. THE WEATHER PATTERN WILL CHANGE LITTLE TODAY AS THE LARGE UPPER RIDGE WILL BECOME ANCHORED ACROSS THE PLAINS AND ROCKIES WHILE THE AFOREMENTIONED FRONT REMAINS STALLED ACROSS SOUTHERN KANSAS. THE WAVE RESPONSIBLE FOR KICKING OFF THE ELEVATED CONVECTION ACROSS NORTH CENTRAL KANSAS IS SHOWN TO GRADUALLY DRIFT TO THE SOUTH THROUGH THE DAY. HOWEVER...STILL EXPECT AT LEAST SOME ISOLATED CONVECTION TO IMPACT MAINLY NORTH CENTRAL KANSAS THROUGH EARLY AFTERNOON AS THE MODELS SHOW DECENT LOW LEVEL CAPE DEVELOPING ACROSS THIS AREA. HIGH TEMPERATURES WILL BE TRICKY TODAY GIVEN PLENTY OF CLOUD COVER AROUND...BUT WILL AIM FOR HIGHS IN THE LOWER 80S NEAR ORD...TO THE MID TO UPPER 80S ACROSS NORTH CENTRAL KANSAS. HOT AND DRY PATTERN THEN LOOKS TO TAKE HOLD OF THE REGION FOR THE WEEKEND AS THE UPPER RIDGE SITS OVER THE PLAINS AND ROCKIES. PRESSURE FALLS ACROSS THE NORTHERN HIGH PLAINS WILL HELP TO GRADUALLY DEEPEN THE LEE TROUGH INTO EASTERN COLORADO AND IN THE PROCESS LIFTING THE STALLED OUT FRONT NORTHEAST OF THE AREA. THIS WILL SET THE STAGE FOR HIGHS IN THE UPPER 80S TO MID 90S THIS WEEKEND. AVIATION...SHOWERS AND A FEW THUNDERSTORMS IN NORTH CENTRAL KANSAS ARE TRYING TO DEVELOP NORTH AND ACROSS THE STATE LINE. DO NOT THINK THESE WILL MAKE IT ALL THE WAY UP TO THE GRI AREA. LOOKS LIKE UPSLOPE CONDITIONS STILL IN PLACE AND SOME FOG AND LOWER CEILINGS MAY DEVELOP A FEW HOURS BEFORE SUNRISE. STILL BELIEVE CLOUDS MAY SCATTER OUT THIS AFTERNOON. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SB ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBUQUERQUE NM 933 PM MDT FRI JUL 20 2007 .UPDATE... LATEST RADAR TRENDS SHOW MOST PERSISTENT AREA OF PRECIP IS ALONG THE E SLOPES OF THE SANGRES IN WESTERN MORA AND COLFAX COUNTIES. RAISED POPS THERE FOR THE REMAINDER OF THE EVE. THE OTHER AREA OF PRECIP OVER THE SW MTNS AND UPPER GILA REGION SHOULD BEGIN TO DISSIPATE PER LATEST RUC GUIDANCE. LOWERED POPS ELSEWHERE TO REFLECT 00Z MODEL TRENDS BUT STILL HELD ON TO ISOLD SINCE CANNOT RULE OUT A STORM DEVELOPING ON REMNANT OUTFLOW BOUNDARIES. LATEST IR IMAGERY ALSO SHOWS CLEAR TO PARTLY CLOUDY SKIES OVER MUCH OF THE E PLAINS AND ANTICIPATE THIS TO CONTINUE THROUGH THE EARLY MORNING. TEMPS AND WINDS LOOK GREAT SO WILL LEAVE UNTOUCHED. && .PREV DISCUSSION...255 PM MDT FRI JUL 20 2007... FORECAST CHALLENGES IN THE SHORT TERM INVOLVE PCPN CHANCES AS WELL AS DIURNAL TEMPS. COMPLICATED...YET RATHER INTERESTING WATER VAPOR LOOP AND RUC ANALYSIS THIS AFTERNOON. STRONG MID/UPPER LEVEL HIGH REMAINS CENTERED OVER NRN COLORADO. MEANWHILE...250MB ANALYSIS HAS AN UPPER LOW TRACKING SLOWLY W/NW OVER SRN NM WITH AN UPR HIGH IN THE SRN TIP OF TEXAS. SUBTROPICAL JET CONTINUES TO ADVECT MOISTURE NORTHWARD FROM THE ERN PAC INTO NORTH CENTRAL MEXICO/SRN TX. THIS INCREASE IN MOISTURE IS ALSO EVIDENT ON THE REGIONAL 12Z SOUNDINGS WITH PRECIPITABLE WATERS IN TEXAS RANGING FROM 1.5 TO 2.0 INCHES... WHILE ABQ REMAINS NEAR THREE-QUARTERS OF AN INCH. WITH EXAMINATION OF THE WATER VAPOR LOOP...IT APPEARS CYCLONIC FLOW AROUND THE UPR LOW IS TAPPING INTO SOME OF THIS SUBTROPICAL MOISTURE AND WRAPPING IT INTO NM ON THE NE QUADRANT. DIFFICULT TO ASCERTAIN THE LEVEL AT WHICH THIS MOISTURE IS RESIDING BASED ON WATER VAPOR...BUT FEEL IT IS HIGH LEVEL MOISTURE BASED ON RUC ANALYSIS OF THE 250MB LOW AND AND IT SHOULD NOT HAVE A HUGE IMPACT ON NM JUST YET. MEANWHILE...A SLOW CONVECTIVE START THIS AFTERNOON...HOWEVER EXPECT SCT SHOWERS/ STORMS TO INCREASE IN COVERAGE LATE THIS AFTERNOON/EVENING ACROSS THE NRN AND WEST CENTRAL MTS. DIRECTIONAL SHEAR WILL ALSO SUPPORT ACTIVITY ACROSS THE NE PLAINS. SLOW MOVING STORMS SHOULD ENCOURAGE LOCALLY HEAVY RAINFALL AND MINOR FLOODING ISSUES. STRONGER STORMS SHOULD DIMINISH BY MIDNIGHT...BUT ISOLATED PCPN STILL POSSIBLE TIL THE MID-MORNING HOURS. EXPECT TEMPS TONIGHT TO BE SIMILAR TO EARLY THIS MORNING. LOW CLOUDS WILL CLAIM MORE REAL ESTATE ACROSS THE SE PLAINS AFTER MIDNIGHT...GENERALLY OF THE MVFR NATURE...DISSIPATING BY LATE MORNING SAT. STILL QUESTIONABLE AS TO THE SPEED OF THE WEAK UPPER LOW...HOWEVER BOTH MODELS ARE FAIRLY CONSISTENT WITH ITS LOCATION IN THE SW OR W CENTRAL PORTIONS OF THE STATE BY 00Z SUN. MAIN FOCUS FOR STORMS ON SAT AFTERNOON WILL BE ACROSS THE CENTRAL/WRN HIGH TERRAIN...WITH A BREAK IN THE NE PLAINS. BY SUN AFTERNOON...UPPER HIGH TO THE NORTH WILL STRENGTHEN AND SHOVE THE WEAK UPR LOW INTO CENTRAL AZ. IN THE MEANTIME...ELY FLOW WILL INCREASE ACROSS TX/NM/MEXICO...WHICH WILL SHOVE THE SUBTROPICAL MOISTURE WESTWARD...PARTICULARLY OVER SRN NM/ AZ AND NRN MEXICO. ELY WAVES EMBEDDED WITHIN THE SRN PERIPHERY OF THE UPPER HIGH WILL ENHANCE CONVECTIVE DEVELOPMENT. IT APPEARS THE SW CORNER OF THE CWA MAY EXPERIENCE THE GREATEST INCREASE IN PCPN. THE NAM IS NOTABLY FASTER AND FURTHER WEST WITH THE UPPER HIGH AND WILL DISCARD SOLUTION ATTM. CONFIDENCE OF EXTENDED REMAINS LOW AS THE GFS/ECMWF/CANADIAN ADVERTISE A RETROGRADING UPPER LOW TRACKING FROM THE OHIO VALLEY TO THE CENTRAL GREAT PLAINS. ALTHOUGH IT MAY SEEM IMPLAUSIBLE...SIMILAR PATTERNS HAVE DEVELOPED IN THE PAST. IF THIS SCENARIO PANS OUT...UPPER HIGH WILL BE SHOVED INTO THE DESERT SW BY THE END OF THE UPCOMING WORK WEEK. DPORTER && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 64 90 61 95 / 10 30 30 20 GALLUP.......................... 57 85 56 88 / 20 30 30 20 GRANTS.......................... 56 86 55 87 / 10 20 40 20 GLENWOOD........................ 59 93 62 91 / 20 30 50 30 CHAMA........................... 48 80 48 82 / 10 30 30 30 LOS ALAMOS...................... 56 82 55 84 / 10 20 30 20 RED RIVER....................... 45 73 44 75 / 20 30 30 20 TAOS............................ 53 83 52 88 / 20 20 20 20 SANTA FE........................ 54 84 55 87 / 20 30 20 20 SANTA FE AIRPORT................ 59 87 58 89 / 10 20 20 20 ESPANOLA........................ 57 90 57 92 / 10 20 20 20 ALBUQUERQUE HEIGHTS............. 67 90 67 91 / 10 20 20 20 ALBUQUERQUE VALLEY.............. 63 91 63 92 / 10 20 20 20 ALBUQUERQUE FOOTHILLS........... 65 88 65 90 / 10 30 30 20 ALBUQUERQUE WEST MESA........... 66 90 66 91 / 10 20 30 20 SOCORRO......................... 63 90 63 90 / 10 20 20 20 SANDIA PARK/CEDAR CREST......... 52 80 53 83 / 10 30 30 20 MORIARTY/ESTANCIA............... 56 87 57 88 / 10 20 20 20 CARRIZOZO....................... 59 88 59 87 / 10 20 20 20 RUIDOSO......................... 55 79 53 79 / 10 30 20 20 RATON........................... 56 87 55 91 / 30 10 5 10 LAS VEGAS....................... 54 83 53 86 / 10 20 20 20 ROY............................. 61 88 60 90 / 10 10 10 5 CLAYTON......................... 62 89 62 92 / 10 10 5 5 SANTA ROSA...................... 64 91 64 93 / 10 10 10 10 TUCUMCARI....................... 65 92 68 95 / 10 10 5 10 FORT SUMNER..................... 65 91 67 93 / 10 10 10 10 CLOVIS.......................... 63 89 64 91 / 10 20 10 10 PORTALES........................ 61 90 63 92 / 10 20 10 10 ROSWELL......................... 66 90 67 92 / 10 20 20 10 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 42 nm AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBUQUERQUE NM 255 PM MDT FRI JUL 20 2007 .DISCUSSION... FORECAST CHALLENGES IN THE SHORT TERM INVOLVE PCPN CHANCES AS WELL AS DIURNAL TEMPS. COMPLICATED...YET RATHER INTERESTING WATER VAPOR LOOP AND RUC ANALYSIS THIS AFTERNOON. STRONG MID/UPPER LEVEL HIGH REMAINS CENTERED OVER NRN COLORADO. MEANWHILE...250MB ANALYSIS HAS AN UPPER LOW TRACKING SLOWLY W/NW OVER SRN NM WITH AN UPR HIGH IN THE SRN TIP OF TEXAS. SUBTROPICAL JET CONTINUES TO ADVECT MOISTURE NORTHWARD FROM THE ERN PAC INTO NORTH CENTRAL MEXICO/SRN TX. THIS INCREASE IN MOISTURE IS ALSO EVIDENT ON THE REGIONAL 12Z SOUNDINGS WITH PRECIPITABLE WATERS IN TEXAS RANGING FROM 1.5 TO 2.0 INCHES... WHILE ABQ REMAINS NEAR THREE-QUARTERS OF AN INCH. WITH EXAMINATION OF THE WATER VAPOR LOOP...IT APPEARS CYCLONIC FLOW AROUND THE UPR LOW IS TAPPING INTO SOME OF THIS SUBTROPICAL MOISTURE AND WRAPPING IT INTO NM ON THE NE QUADRANT. DIFFICULT TO ASCERTAIN THE LEVEL AT WHICH THIS MOISTURE IS RESIDING BASED ON WATER VAPOR...BUT FEEL IT IS HIGH LEVEL MOISTURE BASED ON RUC ANALYSIS OF THE 250MB LOW AND AND IT SHOULD NOT HAVE A HUGE IMPACT ON NM JUST YET. MEANWHILE...A SLOW CONVECTIVE START THIS AFTERNOON...HOWEVER EXPECT SCT SHOWERS/ STORMS TO INCREASE IN COVERAGE LATE THIS AFTERNOON/EVENING ACROSS THE NRN AND WEST CENTRAL MTS. DIRECTIONAL SHEAR WILL ALSO SUPPORT ACTIVITY ACROSS THE NE PLAINS. SLOW MOVING STORMS SHOULD ENCOURAGE LOCALLY HEAVY RAINFALL AND MINOR FLOODING ISSUES. STRONGER STORMS SHOULD DIMINISH BY MIDNIGHT...BUT ISOLATED PCPN STILL POSSIBLE TIL THE MID-MORNING HOURS. EXPECT TEMPS TONIGHT TO BE SIMILAR TO EARLY THIS MORNING. LOW CLOUDS WILL CLAIM MORE REAL ESTATE ACROSS THE SE PLAINS AFTER MIDNIGHT...GENERALLY OF THE MVFR NATURE...DISSIPATING BY LATE MORNING SAT. STILL QUESTIONABLE AS TO THE SPEED OF THE WEAK UPPER LOW...HOWEVER BOTH MODELS ARE FAIRLY CONSISTENT WITH ITS LOCATION IN THE SW OR W CENTRAL PORTIONS OF THE STATE BY 00Z SUN. MAIN FOCUS FOR STORMS ON SAT AFTERNOON WILL BE ACROSS THE CENTRAL/WRN HIGH TERRAIN...WITH A BREAK IN THE NE PLAINS. BY SUN AFTERNOON...UPPER HIGH TO THE NORTH WILL STRENGTHEN AND SHOVE THE WEAK UPR LOW INTO CENTRAL AZ. IN THE MEANTIME...ELY FLOW WILL INCREASE ACROSS TX/NM/MEXICO...WHICH WILL SHOVE THE SUBTROPICAL MOISTURE WESTWARD...PARTICULARLY OVER SRN NM/ AZ AND NRN MEXICO. ELY WAVES EMBEDDED WITHIN THE SRN PERIPHERY OF THE UPPER HIGH WILL ENHANCE CONVECTIVE DEVELOPMENT. IT APPEARS THE SW CORNER OF THE CWA MAY EXPERIENCE THE GREATEST INCREASE IN PCPN. THE NAM IS NOTABLY FASTER AND FURTHER WEST WITH THE UPPER HIGH AND WILL DISCARD SOLUTION ATTM. CONFIDENCE OF EXTENDED REMAINS LOW AS THE GFS/ECMWF/CANADIAN ADVERTISE A RETROGRADING UPPER LOW TRACKING FROM THE OHIO VALLEY TO THE CENTRAL GREAT PLAINS. ALTHOUGH IT MAY SEEM IMPLAUSIBLE...SIMILAR PATTERNS HAVE DEVELOPED IN THE PAST. IF THIS SCENARIO PANS OUT...UPPER HIGH WILL BE SHOVED INTO THE DESERT SW BY THE END OF THE UPCOMING WORK WEEK. DPORTER && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 64 90 61 95 / 30 30 30 20 GALLUP.......................... 57 85 56 88 / 20 30 30 20 GRANTS.......................... 56 86 55 87 / 20 20 40 20 GLENWOOD........................ 59 93 62 91 / 30 30 50 30 CHAMA........................... 48 80 48 82 / 50 30 30 30 LOS ALAMOS...................... 56 82 55 84 / 40 20 30 20 RED RIVER....................... 45 73 44 75 / 40 30 30 20 TAOS............................ 53 83 52 88 / 40 20 20 20 SANTA FE........................ 54 84 55 87 / 30 30 20 20 SANTA FE AIRPORT................ 59 87 58 89 / 30 20 20 20 ESPANOLA........................ 57 90 57 92 / 40 20 20 20 ALBUQUERQUE HEIGHTS............. 67 90 67 91 / 20 20 20 20 ALBUQUERQUE VALLEY.............. 63 91 63 92 / 20 20 20 20 ALBUQUERQUE FOOTHILLS........... 65 88 65 90 / 20 30 30 20 ALBUQUERQUE WEST MESA........... 66 90 66 91 / 20 20 30 20 SOCORRO......................... 63 90 63 90 / 20 20 20 20 SANDIA PARK/CEDAR CREST......... 52 80 53 83 / 20 30 30 20 MORIARTY/ESTANCIA............... 56 87 57 88 / 20 20 20 20 CARRIZOZO....................... 59 88 59 87 / 20 20 20 20 RUIDOSO......................... 55 79 53 79 / 30 30 20 20 RATON........................... 56 87 55 91 / 30 10 5 10 LAS VEGAS....................... 54 83 53 86 / 20 20 20 20 ROY............................. 61 88 60 90 / 20 10 10 5 CLAYTON......................... 62 89 62 92 / 20 10 5 5 SANTA ROSA...................... 64 91 64 93 / 20 10 10 10 TUCUMCARI....................... 65 92 68 95 / 10 10 5 10 FORT SUMNER..................... 65 91 67 93 / 10 10 10 10 CLOVIS.......................... 63 89 64 91 / 10 20 10 10 PORTALES........................ 61 90 63 92 / 10 20 10 10 ROSWELL......................... 66 90 67 92 / 10 20 20 10 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 46 nm AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BUFFALO NY 817 PM EDT THU JUL 19 2007 .SYNOPSIS... AN AREA OF LOW PRESSURE CENTERED OVER NORTHERN NEW YORK WILL CONTINUE TO MOVE AWAY FROM THE REGION TONIGHT. MEANWHILE AN UNSEASONABLY STRONG UPPER LEVEL DISTURBANCE WILL DROP SOUTHEAST ACROSS THE EASTERN GREAT LAKES TONIGHT AND KEEP THE CHANCE OF A FEW SHOWERS AND THUNDERSTORMS FOR TONIGHT THROUGH FRIDAY. AN AREA OF HIGH PRESSURE WILL THEN BUILD ACROSS THE GREAT LAKES OVER THE WEEKEND AND BRING A RETURN TO AMPLE SUNSHINE AND VERY PLEASANT MID SUMMER WEATHER. TEMPERATURES WILL BE A LITTLE COOL ON FRIDAY THEN TEMPERATURES WILL MODERATE AND RETURN TO NEAR NORMAL BY THE END OF THE WEEKEND. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... AREA OF STEADY RAIN IS JUST ABOUT OUT OF THE CWA AT 18Z...AND WILL CLEAR LEWIS COUNTY OVER THE NEXT HOUR OR SO. BEHIND THE SHIELD OF STEADY RAIN MODEST INSTABILITY HAS DEVELOPED WITHIN SOME BINOVC WHICH ALLOWED FOR SOME LIMITED INSOLATION. SPC OBJECTIVE RUC ANALYSIS AT 18Z SHOWING POCKETS OF AROUND 1000J/KG OF CAPE ACROSS PORTIONS OF WESTERN NY...WITH UP TO 1500J/KG ACROSS SOUTHERN ONTARIO WHERE MORE SUNSHINE HAS OCCURRED. A NARROW BAND OF SHOWERS HAS DEVELOPED FROM NEAR FORT ERIE ACROSS METRO BUF EAST TO THE FINGER LAKES ALONG AN AXIS OF LOW LEVEL CONVERGENCE WHICH IS A COMBINATION OF THE PRE-FRONTAL TROUGH AND SOME LAKE ENHANCED CONVERGENCE. OF MORE IMPORTANCE IS A BROKEN LINE OF MORE INTENSE CONVECTION OVER SOUTHERN ONTARIO FROM THE KAWARTHAS TO JUST WEST OF TORONTO AND HAMILTON. THESE STORMS ARE FORMING ALONG THE LEADING EDGE OF STRONG MID LEVEL HEIGHT FALLS AHEAD OF A SHARP MID LEVEL CLOSED CIRCULATION WHERE DPVA IS MAXIMIZED. AT LEAST SCT SHOWERS AND STORMS WILL CONTINUE INTO THE EVENING HOURS...AND MAY BECOME MORE CONCENTRATED FOR AWHILE THIS EVENING AS HEIGHT FALLS OVER SOUTHERN ONTARIO OVERSPREAD THE CWA. WILL MAKE A LAST MINUTE CALL ON POPS FOR THIS EVENING...BUT MAY NEED LIKELY FOR A FEW HOURS INTO THE EVENING. STILL A VERY MARGINAL RISK OF AN ISOLATED SEVERE STORM THIS EVENING WITH ACTIVITY COMING OUT OF SOUTHERN ONTARIO. LARGE SCALE FORCING AND DEEP LAYER SHEAR ARE QUITE FAVORABLE THIS EVENING...HOWEVER LACK OF STRONG INSTABILITY AND RELATIVELY WEAK MID LEVEL LAPSE RATES ARE THE MAIN LIMITING FACTOR. ANY MARGINAL SEVERE RISK WILL END BY MID OR LATE EVENING WITH NOCTURNAL STABILIZATION OF THE BOUNDARY LAYER. OVERNIGHT THE MAIN MID LEVEL TROUGH AXIS CROSSES THE AREA ALONG WITH WRAP AROUND MOISTURE...WHICH WILL KEEP THE CHANCES FOR A FEW SHOWERS OVERNIGHT. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/... ON FRIDAY CYCLONIC FLOW ALOFT CONTINUES AS UNSEASONABLY STRONG TROUGH DIGS ACROSS NEW ENGLAND. NW FLOW ALOFT ALWAYS TRICKY IN THIS AREA AND SUSPECT WE MAY SEE A BAND OF ENHANCED CONVERGENCE DEVELOP FROM THE NIAGARA PENINSULA EAST ACROSS THE NORTHERN HALF OF METRO BUF INTO THE WESTERN FINGER LAKES. MAY SEE SOME ENHANCED SHOWER ACTIVITY ALONG THIS AXIS IF ENOUGH LOW LEVEL MOISTURE REMAINS. EXPECT ANOTHER AREA OF MORE ENHANCED SHOWERS EAST OF LAKE ONTARIO WHERE DEEPER MOISTURE REMAINS AND FAVORABLE UPSLOPE FLOW DEVELOPS. HAVE GONE WITH LOW LIKELY POPS IN THIS AREA...WITH CHANCE ELSEWHERE. ANY LINGERING SHOWERS EAST OF LAKE ONTARIO END FRIDAY EVENING. HIGH PRESSURE WILL THEN BUILD SLOWLY ACROSS THE GREAT LAKES THROUGH THE UPCOMING WEEKEND. A CLOSED MID LEVEL LOW WILL EVENTUALLY DEVELOP OVER THE MID ATLANTIC REGION...HOWEVER OUR CWA WILL BE SITUATED NW OF THIS CLOSED LOW WITHIN A REGION OF MID LEVEL CONFLUENCE WHICH IS THE SO CALLED SWEET SPOT WITH FAIR AND SUNNY WEATHER. TEMPS WILL START CHILLY ON FRIDAY WITH H85 TEMPS ONLY AROUND +10C SUPPORTING HIGHS IN THE LOW 70S ALONG THE LAKE PLAIN AND ONLY UPPER 60S ACROSS THE HIGHER ELEVATIONS OF THE SOUTHERN TIER AND EAST OF LAKE ONTARIO. TEMPS MODERATE BACK TO SEASONAL NORMS BY SUNDAY. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... EARLY IN THIS PERIOD AN UPPER LEVEL IS STILL EXPECTED TO BE OVER THE EASTERN SEABOARD WITH A HIGH AMPLITUDE RIDGE STRETCHING FROM QUEBEC PROVINCE SOUTHWEST INTO THE NATION`S MIDSECTION. THE UPPER LOW IS EXPECTED TO MOVE VERY LITTLE THROUGH EARLY NEXT WEEK BUT ANY PRECIPITATION WILL LIKELY REMAIN TO OUR EAST. OUR BEST CHANCE OF GETTING RAIN WILL BE TUESDAY AS A SHORT WAVE ROTATES THROUGH ON THE WESTERN PERIPHERY OF THE UPPER LOW BUT EVEN THEN THE CHANCES ARE QUITE LOW. TEMPERATURES ARE EXPECTED TO STAY JUST SLIGHTLY BELOW NORMAL THROUGH TUESDAY AND THEN WARM UP CONSIDERABLY WEDNESDAY AND THURSDAY AS THE UPPER RIDGE BUILDS FURTHER EAST. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... AN UPPER LOW DROPPING SE ACROSS THE LOWER LAKES WILL CONTINUE TO BRING SHOWERS WITH SOME EMBEDDED TSTMS ACROSS THE REGION EARLY TONIGHT WITH CONDITIONS VARYING MAINLY FROM MVFR TO IFR. THE SHOWERS AND TSTMS SHLD DECREASE OVERNIGHT EXCEPT FOR AREAS EAST OF LAKE ONTARIO. FRIDAY MORNING A SECONDARY TROUGH MOVING SE ACROSS THE AREA WILL BRING MORE SCATTERED SHOWERS AND TSTMS AND THEY SHLD BE MORE PERSISTENT EAST OF LAKE ONTARIO. MVFR CIGS SHLD IMPROVE TO VFR BY FRIDAY AFTERNOON ESPECIALLY FROM THE FINGER LKS WESTWARD AS THE SYSTEM MOVES FURTHER EAST. THE WEEKEND AND EARLY NEXT WEEK LOOKS LIKE A FAIR WEATHER PATTERN WITH VFR CONDITIONS PREVAILING. A WEAK FRONT MAY PASS THROUGH THE AREA ON TUESDAY HOWEVER. && .MARINE... LOW PRESSURE CENTERED OVER EASTERN NEW YORK THIS AFTERNOON WILL CONTINUE TO TRACK EASTWARD OVERNIGHT. A TIGHTER PRESSURE GRADIENT DEVELOPING ON THE BACK SIDE OF THE LOW WILL HELP INCREASE THE WINDS ACROSS THE LOWER GREAT LAKE REGION TONIGHT INTO FRIDAY. SINCE COLDER AIR WILL ALSO BE BUILDING IN BEHIND THIS SYSTEM THERE WILL BE INSTABILITY AND A TRANSFER OF MOMENTUM FROM WINDS ALOFT. SMALL CRAFT ADVISORIES WILL BE ISSUED FOR BOTH THE LAKE ERIE AND LAKE ONTARIO SHORES. WINDS WILL BEGIN TO SLACKEN ACROSS LAKE ERIE FIRST FRIDAY AFTERNOON AS HIGH PRESSURE APPROACHES FROM THE CENTRAL AND UPPER LAKES. THE WEEKEND LOOKS GOOD AT THIS POINT WITH LIGHTER WINDS AS THE HIGH CONTINUES TO MOVE SLOWLY EASTWARD. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 12 PM EDT FRIDAY FOR LEZ040-041. SMALL CRAFT ADVISORY FROM 4 AM TO 8 PM EDT FRIDAY FOR LOZ043>045. SMALL CRAFT ADVISORY FROM 2 AM TO 8 PM EDT FRIDAY FOR LOZ042. && $$ SYNOPSIS...HITCHCOCK NEAR TERM...HITCHCOCK SHORT TERM...HITCHCOCK LONG TERM...SAGE AVIATION...JJP MARINE...SAGE ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 925 PM EDT FRI JUL 20 2007 .SYNOPSIS... A COLD FRONT WILL MOVE OFF THE COAST OVERNIGHT. LOW PRES WILL DEVELOP ALONG THE FRONT TONIGHT THEN MOVE NE AWAY FROM THE AREA ON SATURDAY. HIGH PRESSURE FROM THE NORTH WILL RIDGE SOUTH INTO NC WITH COOLER AIR SUNDAY THROUGH EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... CONVECTION HAS DIED OFF CONSIDERABLY OVER THE PAST FEW HOURS...STILL SOME LINGERING ISOLATED SHOWERS OVER THE ALBEMARLE SOUND...BUT BULK OF ACTIVITY IS ALONG THE NC/SC BORDER AND OFFSHORE. AS FOR THE UPDATE TONIGHT...LOWERED MIN TEMPS INLAND A DEGREE OR TWO OVERNIGHT. SCALED BACK POPS QUITE A BIT...RUC AND ARW HAVE ALL ACTIVITY OFFSHORE BY AROUND 07Z. KEPT ISOLATED CHANCE FOR COASTAL COUNTIES UNTIL AROUND MIDNIGHT. GENERALLY MOSTLY CLOUDY SKIES THROUGHOUT THE FORECAST AREA...BECOMING PARTLY CLOUDY AS FRONT MOVES OFFSHORE OVER THE NEXT FEW HOURS. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY NIGHT/... NAM LOOKS TO BE THE OBVIOUS CHOICE IN MODELS...ESPECIALLY FOR TOMORROW MORNING IN LIGHT OF HOW IT IS VERIFYING THIS AFTERNOON. WE CONT POPS ALONG THE IMMEDIATE COAST IN THE 20-30 RANGE FOR TONIGHT AND KEEP SMALL POPS OVER THE EASTERN PORTION OF CWA FOR TOMORROW BASED ON NAM. THEREAFTER...BOTH MODELS INDICATING DRIER WEATHER FOR SUNDAY AND MONDAY. MODELS HINT AT PCPN ON MONDAY BUT WILL OUT POPS ATTM BASED ON COLLABORATION. && .LONG TERM /TUESDAY THROUGH FRIDAY/... LOWER THAN NORMAL CONFIDENCE IN FORECAST. MODELS HAVING TROUBLE HANDLING CUT-OFF UPPER LOW. SOME WANT TO RETROGRADE IT TOWARD THE SOUTH CENTRAL US INTO A STRONG UPPER RIDGE WHILE OTHERS WOULD KEEP IT OVER THE CENTRAL/SOUTHERN APLCHS. WE FEEL CONFIDENT THAT COOLER AIR WILL FILTER INTO THE REGION BEHIND TONIGHTS FRONT...HOWEVER COOL/CYCLONIC FLOW ALOFT WOULD BE CONDUCIVE TO SCT SHOWERS/STORMS THROUGH THE PERIOD. THEREFORE WILL FORECAST TEMPS A LITTLE BELOW NORMAL WITH SMALL CHANCES FOR SHOWERS AND STORMS EACH DAY. && .AVIATION /01Z SATURDAY THROUGH WEDNESDAY/... CDFNT WILL MOVE THRU AREA OVERNIGHT WITH ISOLD CONVECTION ALG AND AHD OF THE FNT THRU ABT 12Z...AND WIND SHIFT TO THE N AND NE. FCST IFR CIGS AND MVFR VSBYS OVERNIGHT ACRS SRN TERMINAL SITES WHERE BTR LOW LVL MSTR IS AVBL...OTRW VFR CIGS/VSBYS EXPECTED THRU SAT EVE OUTSIDE OF ISOLD DIURNAL CONVECTION. SCT LOW CLDS EXPECTED TO DVLP DURG DAYTIME HTG ON SAT ARND 4K FT. GOOD CHC FOR IFR FOG EARLY SUN AND MONDAY MORNING IN LIGHT NLY FLOW. SCT AFTERNOON CONVECTION SHOULD RETURN TO THE AREA TUESDAY AND WEDNESDAY AFTERNOON AS WE RETURN TO A SOUTHERLY LOW LEVEL WIND FLOW. && .MARINE... DELAYED INCREASE OF STRONGER POST FRONTAL WINDS TIL LATER TONIGHT AND ALSO DECREASED THEM SLIGHTLY. OUR LOCAL WRF MODEL SEEMS TO BE TOO DEEP WITH SFC LOW INIT OFF THE CST AND THINK ITS WINDS ARE A BIT TOO STRONG. WENT CLOSER TO NAM/GFS AND KEPT MARGINAL SCA ALL WTRS DEVELOPING LATER TONIGHT. SCA WILL CONT N OF LOOKOUT INTO SAT NIGHT AS N/NE WINDS CONT IN THE 15 TO 20 KT RANGE WITH SEAS 4 TO 6 FT. .RIP CURRENTS... DEVELOPING ONSHORE FLOW NORTH OF HATTERAS WILL PRODUCE A MODERATE THREAT FOR RIP CURRENTS FOR SATURDAY AND PROBABLY SUNDAY AS WELL. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 2 AM TO 11 AM EDT SATURDAY FOR AMZ130-135. SMALL CRAFT ADVISORY FROM 2 AM SATURDAY TO 2 AM EDT SUNDAY FOR AMZ150-152-154-156. SMALL CRAFT ADVISORY FROM 6 AM TO 11 AM EDT SATURDAY FOR AMZ158. && $$ SYNOPSIS...JME NEAR TERM...CLQ SHORT TERM...TK LONG TERM...JME AVIATION...JC MARINE...RF nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 859 PM EDT FRI JUL 20 2007 .SYNOPSIS... A COLD FRONT WILL DROP SOUTHEAST THROUGH THE AREA OVERNIGHT. HIGH PRESSURE...AND A DRIER AND COOLER AIR MASS WILL BUILD IN FROM THE NORTHWEST OVER THE WEEKEND. && .NEAR TERM /UNTIL 7 AM SATURDAY MORNING/... SFC ANALYSIS THIS EVENING SHOWS A BOUNDARY IN THE FORM OF A MOISTURE DISCONTINUITY (JULY COLD FRONT) SINKING SLOWLY SOUTH THROUGH NORTH-CENTRAL NC. AHEAD OF THE BOUNDARY DEWPOINTS WERE IN THE MID 60S TO LOWER 70S...AND BEHIND THE BOUNDARY DEWPOINTS WERE IN THE MID 50S (55F HNZ...54F DAN). A WEAK AREA OF LOW PRESSURE WAS LOCATED NEAR/ALONG THE SC COAST BETWEEN CHARLESTON AND MYRTLE BEACH. ALOFT...RUC H5 HEIGHT/VORTICITY FIELDS AND WV IMAGERY SHOW SHORTWAVE ENERGY DROPPING SOUTHEAST THROUGH GA/SC. CONVECTIVE ACTIVITY THIS EVENING IS NOW CONFINED PRIMARILY TO SC... WITH A FEW WEAK SHOWERS IN FAR EASTERN NC. WITH THE SFC BOUNDARY DROPPING SOUTH INTO THE AREA AND DEWPOINTS FALLING INTO THE LOWER 60S AND 50S...AND NOW THAT THE UPPER LEVEL SUPPORT HAS SHIFTED SOUTH OF THE AREA...WITH TAKE POPS OUT EVERYWHERE EXCEPT FOR THE SC/NC BORDER COUNTIES WHERE A SLIGHT CHANCE (20%) FOR A SHOWER WILL BE LEFT IN UNTIL MIDNIGHT TO ACCOUNT FOR ONGOING ACTIVITY NEAR THE SC/NC BORDER. OTHERWISE...FORECAST ON TRACK THIS EVENING WITH PARTLY TO MOSTLY CLOUDY SKIES. -VINCENT && .SHORT TERM /7 AM SATURDAY MORNING THROUGH MONDAY/... NORTHWEST FLOW ALOFT AND NORTHEAST FLOW AT THE SURFACE WILL RESULT IN BELOW NORMAL TEMPS THROUGH THE WEEKEND. DESPITE MOSTLY SUNNY SKIES TOMORROW...HIGHS WILL ONLY MAKE IT TO THE 83-87 DEGREE AS 1000-850 MB THICKNESSES FALL SEVERAL METERS BELOW CLIMO. BY SATURDAY NIGHT...A PIECE OF THE UPPER LEVEL TROUGH WILL SPLIT OFF FROM THE MAIN TROUGH...CLOSING OFF OVER THE MIDDLE ATLANTIC. THERE HAVE BEEN NUMEROUS MODEL SOLUTIONS ON HOW TO HANDLE THIS CLOSED LOW...WITH MOST DATA NOW FAVORING A SLOW RETROGRESSION. THIS IS IN STARK CONTRAST TO YESTERDAY WHERE THE GFS SHOWED THE UPPER TROUGH LIFTING OFF TO THE NORTHEAST...RESULTING IN BUILDING HEIGHTS ACROSS THE EAST. EVEN THE ECMWF HAS HAD DIFFICULTY GATHERING A HANDLE ON THE PATTERN. IT IS LOOKING INCREASINGLY LIKELY THAT WE WILL HAVE A CLOSED LOW TO CONTEND WITH JUST TO OUR NORTH THROUGH AT LEAST MONDAY. IT STILL REMAINS TO BE SEEN ON HOW DRASTICALLY THIS WILL ALTER OUR SENSIBLE WEATHER ON SUNDAY AND MONDAY. WHAT IS LIKELY NOT TO CHANGE IS THE CONTINUATION OF BELOW NORMAL TEMPERATURES WITH HIGHS IN THE 80S AND LOWS IN THE 60S...WITH PERHAPS A FEW UPPER 50S ON SUNDAY MORNING. ONE CHANGE WE COULD SEE IS MORE CLOUD COVER THAN WHAT WAS PREVIOUSLY THOUGHT. FORECAST SOUNDINGS SHOW STEEP LOW LEVEL LAPSE RATES...AIDED BY THE DIFFERENTIAL IN THE HEATING OF THE SFC LAYER AND THE COOL CORE OF THE UPPER LOW. WITH POCKETS OF 850-700 MB MOISTURE ROTATING AROUND THE LOW...ENHANCED DIURNAL CUMULUS IS CERTAINLY POSSIBLE. THE FORECAST WILL REMAIN DRY FOR NOW...BUT WE WILL HAVE TO MONITOR THE PROGRESSION OF THE CLOSED LOW. THE LATEST GUIDANCE IS HINTING AT SOME ISENTROPIC LIFT SUN NIGHT/MONDAY AS THE SFC FLOW REMAINS E/NE AND THE LOW TO MID LEVEL FLOW AROUND THE UPPER LOW TURNS S/SE. NEEDLESS TO SAY...MORE UNCERTAINTY REVOLVES AROUND THIS PORTION OF THE FORECAST COMPARED TO THIS TIME YESTERDAY. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... MODELS DO NOT IN GENERAL HANDLE CLOSED UPPER LOWS WELL. SOLUTIONS BY THE MODELS FOR THIS PERIOD ARE A DIVERSE BUNCH...THUS CONFIDENCE IS LESS THAN LOW. THE FORECAST WILL BE REASONABLY SIMILAR TO THE CURRENT FORECAST...WITH AN UPPER LOW DISTANCING ITSELF FROM NORTH CAROLINA TOWARD THE END OF THE WORK WEEK. THIS ALLOWS AFTERNOON TEMPERATURES TO RETURN TO THE LOW 90S BY THE END OF THE WORK WEEK. WILL LIMIT RAIN CHANCES TO LESS THAN ONE IN THREE AND MAINLY DURING THE FAVORED PERIOD OF AFTERNOONS AND EVENINGS. && .AVIATION /01Z SATURDAY THROUGH WEDNESDAY/... LIGHT PRECIPITATION WILL BE ENDING FROM NORTHWEST TO SOUTHEAST THIS AFTERNOON. CEILINGS GENERALLY NOT WIDESPREAD AND ASSOCIATED WITH PRECIPITATION... OTHERWISE CEILINGS ABOVE 10000 FEET. WITH LIGHT NORTH WINDS ONLY BRIEF MVFR FOG NEAR DAWN EXPECTED...EXCEPT PERHAPS ROCKY MOUNT. NO STRATUS DEVELOPMENT FORECAST. A FEW CUMULUS SHOULD APPEAR IN THE LATE MORNING SATURDAY. DRY CONDITIONS ARE FORECAST FOR SATURDAY THROUGH MONDAY NIGHT AS A LOW LEVEL NORTHEAST FLOW SETS UP. VFR CONDITIONS ANTICIPATED DURING THIS PERIOD. THE FORECAST FOR THE REMAINDER OF THE WORK WEEK IS UNCERTAIN... ALTHOUGH CHANCES FOR AFTERNOON SHOWERS OR THUNDERSTORMS WILL LIKELY RETURN TO THE FORECAST BY MID WEEK. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...VINCENT SHORT TERM...JFB LONG TERM...RLH AVIATION...RLH nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 320 AM EDT FRI JUL 20 2007 .SYNOPSIS... A COLD FRONT WILL DROP SOUTHEAST THROUGH THE AREA TODAY. A DRIER AND MORE SEASONABLE AIR MASS WILL BUILD IN FROM THE NORTHWEST OVER THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... OUTFLOW BOUNDARY IS CURRENTLY DROPPING SOUTH OVER WFO RALEIGH. THE AIR MASS OVER ALL BUT THE FAR NORTHERN COUNTIES REMAINS MODERATELY UNSTABLE WITH LAPS SOUNDINGS AND RUC ANALYSES SHOWING CAPES HOLDING AOA 1000 J/KG... HOWEVER THE LARGE SCALE FORCING IN THE FORM OF MID LEVEL POSITIVE VORTICITY ADVECTION AND UPPER DIVERGENCE IS STILL HOLDING JUST N AND NW OF THE CWA. UPSTREAM CONVECTION HAS WEAKENED CONSIDERABLY OVER THE LAST FEW HOURS AND APPEARS TO BE FALLING VICTIM TO THE INCREASINGLY WESTERLY 850 MB FLOW... DIMINISHED INSTABILITY... AND DECREASED LOW LEVEL CONFLUENCE. THE COLD FRONT... AS DEFINED BY THE LEADING EDGE OF MUCH LOWER SURFACE THETA-E VALUES... CONTINUES A STEADY SSE MOVEMENT THROUGH THE OHIO VALLEY... ON TRACK TO DROP THROUGH NC FROM MID-LATE MORNING THROUGH MID EVENING. PRECIP COVERAGE AHEAD OF THE FRONT MAY BE LIMITED SOMEWHAT BY THE WESTERLY LOW LEVEL WINDS... HOWEVER THIS IS LIKELY TO ONLY AFFECT THE PIEDMONT COUNTIES... WHERE POPS TODAY ARE ALREADY LOWER THAN TO THE EAST AND SOUTH... WHERE MORNING SUN WILL HELP WITH DESTABILIZATION AND THERMODYNAMIC FORCING TO PRODUCE BETTER SHOWER AND STORM COVERAGE. WITH PRECIPITABLE WATER VALUES OF 1.8-2.1 INCHES... NOT MUCH LIFT IS NEEDED TO PRODUCE PRECIPITATION. HAVE HELD WITH 40-53% POPS. SEVERE STORM THREAT WILL BE LIMITED BY THE LOW 15-20 KTS (AT MOST) DEEP LAYER SHEAR... THE FAIRLY WEAK MID LEVEL LAPSE RATES... AND THE FORECAST SKINNY CAPE WHICH FAVORS WEAKER VERTICAL ACCELERATIONS. BUT THE FLOW WILL STILL BE ENOUGH FOR ORGANIZED MULTICELLS AND THE LOW LEVEL LAPSE RATES WILL BE HIGH ENOUGH FOR THE RISK OF DAMAGING WINDS WITH A FEW CELLS... AND LIFT MAY ALSO BE ENHANCED BY UPPER DIVERGENCE IN THE RIGHT ENTRANCE REGION OF THE JET. HIGHS 85-93... BANKING ON ENOUGH SUNSHINE EARLY ACROSS THE SOUTHEAST CWA TO PUSH UP TEMPERATURES. MODELS ARE STILL INDICATING A QUICK EXIT OF THE PRECIP OUT OF THE AREA BY 00Z... AND HAVE HELD ONTO POPS IN THE SOUTH AND EAST ONLY THROUGH MID EVENING. THE COLUMN DRIES OUT CONSIDERABLY AND SKY COVER SHOULD QUICKLY DECREASE FROM N TO S TONIGHT... ALTHOUGH JET-INDUCED HIGH CLOUDS SHOULD PERSIST. LOWS 60-70. -GIH && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... A SCENARIO OF ABUNDANT SUNSHINE AND A STABILIZING COLUMN OVER THE WEEKEND LOOKED LIKE A SURE BET YESTERDAY WITH THE FRONT SOUTHEAST OF THE CWA AND HIGH PRESSURE BEGINNING TO BUILD IN FROM THE NORTHWEST... HOWEVER THE LATEST MODELS HAVE THROWN A BIT OF A WRENCH INTO THIS PICTURE WITH NORTHEAST LOW LEVEL FLOW BRINGING PATCHES OF 850-700 MB MOISTURE ACROSS CENTRAL NC THROUGH THE PERIOD. IF THIS MOISTURE ADVECTION DOES COME TO PASS... WHICH IS ENTIRELY POSSIBLE CONSIDERING THE CURRENT MOISTURE ON THE EASTERN FRIDGE OF THE SURFACE HIGH... GIVEN THE LIKELIHOOD THAT THE MOISTURE WILL BE TRAPPED BY THE WEAK SUBSIDENCE INVERSION ALOFT... PERIODS OF PARTLY TO MOSTLY CLOUDY SKIES ARE CERTAINLY POSSIBLE OVER THE WEEKEND... PARTICULARLY WITH THE MID LEVEL VORTEX SETTLING OVER VA AND NORTHERN NC. HAVE RAISED SKY COVER A BIT... BUT KEPT IT IN THE PARTLY CLOUDY TERRITORY FOR NOW. HAVE MADE MINOR DOWNWARD ADJUSTMENTS TO HIGHS... 83-88 BOTH DAYS. LOWS 59-64 THROUGH SUNDAY NIGHT. && .LONG TERM /MONDAY THROUGH THURSDAY/... THE GFS HAS BEEN FAIRLY CONSISTENT TAKING THE MID LEVEL VORTEX SLOWLY NNE INTO NEW ENGLAND MONDAY THROUGH TUESDAY WITH THE TRAILING TROUGH AXIS CONTINUING TO EXTEND DOWN THROUGH WESTERN NC AND THE WESTERN GULF STATES. HIGH PRESSURE WILL NOSE INTO NC FROM THE NORTH... WITH NORTHERLY LOW LEVEL WINDS BOOSTED BY THE FLOW AROUND THE LOW PRESSURE CENTER OFF DELMARVA. FORECAST SOUNDINGS SHOW LIMITED BOUNDARY LAYER MOISTURE AND QUITE A BIT OF WARM AND DRY AIR IN THE MID LEVELS MONDAY... AND A CONTINUED DRY FORECAST AND BELOW NORMAL TEMPERATURES LOOKS GOOD. MID LEVEL HEIGHTS RISE QUICKLY OVER NC TUESDAY... AND THE HIGH PRESSURE OFF THE SOUTHEAST COAST BECOMES OUR DOMINANT SURFACE FEATURE WITH INCREASING ONSHORE LOW LEVEL SOUTH AND SOUTHEAST FLOW INTO NC AS WHAT IS LEFT OF THE OLD FRONT SHIFTS NORTHWARD. AN INCREASE IN CLOUD COVER AND SLIGHT CHANCE POPS LOOKS JUSTIFIED... AND FURTHERMORE... IF THE 00Z/20 GFS IS CORRECT WITH ITS DEEP SATURATED COLUMN... HIGHER RAIN CHANCES MAY BE NEEDED FOR TUESDAY. THE PICTURE GETS MURKIER WEDNESDAY/THURSDAY AS THE GFS NOW DEVELOPS A WEAK MID LEVEL LOW OVER THE SOUTHERN APPALACHIANS... AGAINST THE PREVIOUS RUN WHICH DEVELOPED IT MUCH FARTHER SOUTHWEST OVER AL/AR. WITH SUCH A WEAK FLOW PATTERN AND THE AVAILABILITY OF ATLANTIC MOISTURE FEEDING INTO NC... WILL KEEP LOW CHANCE DAYTIME POPS... PARTLY TO MOSTLY CLOUDY SKIES... AND NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES BOTH DAYS. -GIH && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... A PRE-FRONTAL TROUGH AND NUMEROUS CONVECTIVE BOUNDARIES WERE COMING SOUTH INTO NORTHERN NC AS OF 200 AM/FRIDAY MORNING. WHERE THESE BOUNDARIES END UP THIS MORNING WILL PROBABLY BE WHERE THE INITIAL CONVECTION FIRES TODAY. THE NW TERMINALS (KINT AND KGSO) APPEAR TO GET THE WIND SHIFT TO THE NW-N BEFORE CONVECTION CAN DEVELOP THIS MORNING. KRDU/KRWI SHOULD SEE THE BEST CHANCE FROM AROUND NOON THROUGH MID AFTERNOON (WILL INCLUDE CB IN THE TAF FOR NOW). KFAY WILL HAVE THE BEST CHANCE FROM MID AFTERNOON TO SUNSET OR SO. COLD FRONT WILL BE WELL SE OF THE AREA BY MIDNIGHT TONIGHT... WITH ONLY A BIT OF MVFR FOG AT KFAY/KRWI OVERNIGHT. DRY CONDITIONS ARE FORECAST FOR SATURDAY THROUGH MONDAY AS A LOW LEVEL NE FLOW SETS UP. VFR CONDITIONS ANTICIPATED. THE OUTLOOK FOR NEXT WEEK IS FOR VFR UNDER DRY HIGH PRESSURE. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...HARTFIELD LONG TERM...HARTFIELD AVIATION...BADGETT nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 1003 PM EDT THU JUL 19 2007 .SYNOPSIS... A COLD FRONT WILL DROP SOUTHEAST THROUGH THE AREA FRIDAY AFTERNOON. A DRIER AND MORE SEASONABLE AIR MASS WILL BUILD IN FROM THE NORTHWEST OVER THE WEEKEND. && .NEAR TERM /UNTIL 7 AM FRIDAY MORNING/... WHAT LITTLE CONVECTIVE ACTIVITY DID DEVELOP THIS AFTERNOON HAS SINCE DIED OUT ACROSS THE AREA. ONE STORM THAT DEVELOPED IN ALAMANCE COUNTY BECAME QUITE IMPRESSIVE...PROMPTING A WARNING AS IT DEVELOPED FROM VIRTUALLY NOTHING INTO A 50-55 KFT ECHO TOP STORM WITH MAX REFLECTIVITIES AROUND 70 DBZ UP TO 26 KFT IN ONLY 20-25 MINUTES! THE STORM SUBSEQUENTLY PRODUCED WIND DAMAGE NEAR THE ALAMANCE/ORANGE COUNTY BORDER SOUTH OF INTERSTATE 85. CONVECTIVE ACTIVITY CONTINUES NORTH OF THE AREA FROM VA ALL THE WAY WEST THROUGH KY INTO MO. NAM12/RUC MODEL DATA AND CURRENT OBS SHOW THIS ACTIVITY HAS DEVELOPED ALONG AND AHEAD OF A SHORTWAVE AND ELONGATED VORT MAX ASSOC/W AN AMPLIFYING UPPER LEVEL TROUGH OVER THE GREAT LAKES AND MID ATLANTIC...AND AHEAD OF A SFC COLD FRONT DROPPING SOUTH THROUGH THE OHIO VALLEY. THIS ACTIVITY WILL STAY NORTH AND NORTHWEST OF THE AREA FOR MOST OF TONIGHT...ALTHOUGH N/NW PORTIONS OF THE CWA...INCLUDING THE TRIAD...MAY SEE SHOWERS...OR POSSIBLY AN ISOLATED STORM...APPROACHING BEFORE SUNRISE AS THE SHORTWAVE ENERGY AND SFC COLD FRONT CONTINUE TO DROP SOUTH. CURRENT FORECAST DEPICTS THIS WITH A SLIGHT CHANCE OF SHOWERS/STORMS BEGINNING AT 09Z WEST AND NORTH OF THE TRIANGLE...WITH CHANCES EXPANDING TO THE EAST AND SOUTH AND INCREASING AFTER SUNRISE. OTHER THAN A FEW MINOR CHANGES TO CLOUD COVER AND HOURLY TEMPS/DEWPOINTS...NO CHANGE TO THE CURRENT FORECAST IS PLANNED THIS EVENING. -VINCENT && .SHORT TERM /7 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... THE AFOREMENTIONED SHORTWAVE WILL MOVE THROUGH CENTRAL NC DURING THE DAY TOMORROW AS A LONGWAVE TROUGH AMPLIFIES OVER THE EASTERN U.S. A COLD FRONT WILL MOVE ACROSS THE AREA AS A RESULT...PROVIDING AT LEAST A SOMEWHAT BETTER CHANCE FOR PRECIP. THERE IS STILL SOME MODEL DISAGREEMENT ON TIMING OF THE FRONT WITH THE NAM BEING ABOUT 6 HRS QUICKER THAN THE GFS...BRINGING THE FRONT THROUGH BEFORE 18Z. BOTH MODELS DO SLOW THE FRONT DOWN SOME BY TOMORROW AFTERNOON AS A WEAK SFC LOW DEVELOPS ALONG THE FRONT AND TRACKS UP EASTERN NC. THE EXACT TRACK OF THE SFC LOW WILL DETERMINE BETTER RAIN CHANCES AND SEVERE WEATHER POTENTIAL. KEPT POPS IN THE CHANCE CATEGORY FOR NOW. THERE WILL BE LARGE SCALE ASCENT AHEAD OF THE SHORTWAVE ALONG WITH A WARM AND MOIST AIRMASS. HOWEVER...PERSISTENT WESTERLY FLOW IN THE LOW LEVELS WILL LIKELY INHIBIT CONVECTIVE POTENTIAL TO SOME DEGREE. BEST CHANCES WILL BE IN THE COASTAL PLAIN...DUE TO EXPECTED LONGER DURATION OF DESTABILIZATION AND CLOSER PROXIMITY TO WEAK SFC LOW DEVELOPMENT. REGARDING SVR WX POTENTIAL...SPC HAS PLACED THE SOUTHERN COASTAL PLAIN IN A SLIGHT RISK FOR TOMORROW. CANNOT RULE OUT A SVR STORM OR TWO TOMORROW GIVEN MLCAPES OF 1000-1500 J/KG AND THE PRESENCE OF LARGE SCALE ASCENT WITH THE UPPER TROUGH. A FEW NEGATIVES ARE THE LACK OF DEEP LAYER SHEAR (ONLY ON THE ORDER OF 20-25KTS) AND WEAK MID LEVEL LAPSE RATES WITH FORECAST SOUNDINGS SHOWING A NEAR MOIST ADIABATIC PROFILE. HAIL POTENTIAL IS LIMITED GIVEN HIGH FREEZING LEVELS OF AROUND 14 KFT AND -20C AROUND 25 KFT. LOCALIZED DAMAGING WINDS APPEAR TO BE THE MAIN THREAT. SFC FRONT AND UPPER LEVEL ENERGY MOVE EAST TOMORROW NIGHT WITH COOL HIGH PRESSURE BUILDING IN ON SATURDAY. TEMPS WILL DROP TO BELOW NORMAL LEVELS UNDER THE DEEP NORTHERLY FLOW. && .LONG TERM /SUNDAY THROUGH THURSDAY/... THE ANOMALOUSLY DEEP TROUGH WILL PERSIST OVER THE EAST ON SUNDAY... MAINTAINING OUR DRY WEATHER AND BELOW NORMAL TEMPERATURES. THERE IS SOME DISAGREEMENT IN THE MID RANGE MODELS ON HOW TO HANDLE THE TROUGH AFTER SUNDAY. THE ECMWF WANTS TO CLOSE OFF THE LOW AND RETROGRADE IT WEST WHILE THE GFS AND ITS ENSEMBLES BEGIN TO LIFT OUT THE TROUGH BY THE BEGINNING OF THE WEEK. FOR NOW WILL SIDE WITH THE GFS ENSEMBLE MEAN SHOWING HEIGHTS RISING ACROSS OUR AREA NEXT WEEK. THIS SHOULD RESULT IN A GRADUAL RETURN TO NORMAL TEMPS...POSSIBLY BECOMING ABOVE NORMAL BY THE MIDDLE OF NEXT WEEK. THE ONLY RAIN CHANCES IN THE EXTEND LOOK TO BE POSSIBLE ISOLATED DIURNAL CONVECTION WED/THU. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... LIMITED CONVECTION DEVELOPED IN THE EARLY AFTERNOON OUTSIDE CENTRAL NORTH CAROLINA. SOME CONVECTION SHOULD DRIFT IN FROM THE WEST BEFORE SUNSET AND DEVELOPMENT IN THE SOUTHEAST IS STILL POSSIBLE. COVERAGE SHOULD BE LIMITED AND ODDS ARE TAF SITES WILL BE DRY. MVFR FOG MAINLY NEAR DAWN ALTHOUGH LIKELY DEVELOPING EARLIER IN THE EAST WHERE LOW LEVEL MOISTURE IS BEST. TROUGH FORECAST TO SWEEP INTO THE NORTHWEST AROUND SUNRISE. WITH WINDS ALOFT FROM THE WEST AHEAD OF THIS SYSTEM... MUCH OF CENTRAL NORTH CAROLINA COULD END UP DRY...WITH LOW VFR CEILINGS FAILING TO DEVELOP OTHER THAN TOWARD THE VIRGINIA BORDER. SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS ARE FORECAST THROUGH FRIDAY NIGHT. AREAS OF MVFR CONDITIONS IN FOG EACH MORNING AROUND DAWN. DRY CONDITIONS ARE FORECAST FOR SATURDAY INTO THE FIRST OF NEXT WEEK. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...VINCENT SHORT TERM...JFB LONG TERM...JFB AVIATION...RLH nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 950 AM EDT THU JUL 19 2007 .SYNOPSIS... WARM... HUMID... AND UNSETTLED WEATHER WILL PERSIST OVER THE REGION INTO FRIDAY. A COLD FRONT WILL DROP SOUTHEAST THROUGH THE AREA LATE FRIDAY. A DRIER AND MORE SEASONABLE AIR MASS WILL BUILD IN FROM THE NORTHWEST OVER THE WEEKEND. && .NEAR TERM /TODAY/... HEAT...00Z NAM MODEL CAME AROUND TO THE PREVIOUS DAYS GFS LOW LEVEL THICKNESS PATTERN...WITH A MAXIMA OVER VIRGINIA...BUT DROPPED THICKNESS ABOUT 14 METERS FROM THE WEDNESDAY RUN. GREENSBORO THICKNESS CAME IN AT 1424 METERS THIS MORNING AND THE OVERNIGHT MODEL FORECAST OF ONLY A SINGLE DIGIT RISE IN THICKNESS SIMPLY IS NOT GOING TO HAPPEN. THE RUC MODEL VALUES OF 1440 PLUS METERS AND 850 TEMPERATURES IN EXCESS OF 20 CELSIUS NEAR AND WEST OF HIGHWAY ONE LOOK MUCH MORE REASONABLE FOR 21Z TODAY. DIURNAL RISES OVER THE PAST TWO DAYS HAVE BEEN ABOUT 17 METERS. HEAT ALOFT IN THE WEST WILL EVEN OUT THE SURFACE TEMPERATURES AND EXPECT LITTLE VARIATION ACROSS CENTRAL NORTH CAROLINA 97 TO NEAR 100. BEST BET FOR TRIPLE DIGITS WOULD BE ROANOKE RAPIDS. DEW POINTS AT 9 AM ARE MID 60S IN THE TRIAD (NORTHWEST)... AROUND 70 NEAR HIGHWAY ONE AND AROUND 73 IN THE EAST. WEST FLOW ALOFT WILL BRING SOME DOWNSLOPE DRYING AND HEATING TO THE WEST...BUT WIND SPEEDS ARE NOT HIGH ENOUGH TO ADVECT THIS ACROSS THE ENTIRE AREA. AS WE MIX WITH HEATING TO LEVELS ABOVE 7000 FEET...CURRENT DEW POINTS SHOULD FALL AT LEAST A COUPLE OF DEGREES. THIS WOULD PUT HEAT INDICES HIGHWAY ONE AND EAST ABOVE 100 DEGREES FOR MUCH OF THE AFTERNOON WITH SOME LOCATIONS BRIEFLY TOUCHING 105. CONVECTION...MID LEVEL LAPSE RATES ARE NOT GREATLY UNSTABLE HOWEVER LIFTED INDICES FALL TO AROUND MINUS SIX OR SEVEN THIS AFTERNOON. ALTHOUGH WEST FLOW IS WEAK...IT SHOULD BE ENOUGH TO KEEP THE SEA BREEZE FROM MOVING TOO FAR INLAND. THE BEST MOISTURE IS IN OUR EAST PARTS EAST OF INTERSTATE 95 AND RAIN CHANCE... THOUGH SMALL...WILL BE BEST THERE. CAPE VALUES POTENTIALLY OF 3 TO 4 THOUSAND. WINDS ARE WEAK BUT HIGH MIXING HEIGHTS AND AN INVERTED "V" BOUNDARY LAYER RISK EVAPORATIVE COOLING AIDED DOWNBURSTS REACHING THE GROUND. ALTHOUGH FREEZING LEVELS ARE HIGH...A STRONG CONVECTIVE CORE WILL LOCALLY DROP FREEZING LEVELS. A SINGLE CELL WITH GOLF BALL HAIL AND DAMAGING WINDS CERTAINLY POSSIBLE...MAINLY HIGHWAY ONE AND EAST. && .SHORT TERM /TONIGHT THROUGH SATURDAY/... MUCH OF TONIGHT LOOKS DRY... ALTHOUGH THE MODELS DEPICT MID LEVEL POSITIVE VORTICITY ADVECTINO PUSHING INTO THE NORTHWEST PIEDMONT TOWARD MORNING. TRYING TO PIN DOWN THE TIMING AND STRENGTH OF MID LEVEL DYNAMICS RESULTING FROM ONGOING COPIOUS MESOSCALE CONVECTIVE COMPLEX ACTIVITY OVER THE MIDWEST IS DICEY AT BEST... ESPECIALLY WITH THE DEGREE OF CONVECTIVE FEEDBACK NOTED ON THE GFS. ALSO OF NOTE IS THE NAM`S 850 MILLIBAR THETA-E RIDGE AND 30 TO 35 KNOT WESTERLY 850 MILLIBAR JETLET BOTH NOSING INTO SOUTHWEST NORTH CAROLINA OVERNIGHT... SUGGESTING THE NORTH CAROLINA MOUNTAINS INTO THE SOUTHERN PIEDMONT COULD SEE A WEAK MESOSCALE CONVECTIVE COMPLEX OVERNIGHT. WILL NEED TO KEEP AN EYE ON THIS POTENTIAL... AND FOR NOW WILL BRING IN A SLIGHT CHANCE IN THE FAR WESTERN COUNTIES VERY LATE TONIGHT. WILL HAVE ISOLATED POPS IN THE NORTHWEST FRIDAY MORNING WITH THE POSSIBLE POSITIVE VORTICITY ADVECTION... BUT THE BETTER COVERAGE OVERALL SHOULD HOLD OFF UNTIL THE CONVECTIVE TEMPERATURE IS ACHIEVED IN THE LATE MORNING TO EARLY AFTERNOON ON FRIDAY. WILL HANG ON TO 40 TO 50 PERCENT POPS FRIDAY AFTERNOON INTO EARLY EVENING... TAPERING OFF NORTHWEST TO SOUTHEAST FRIDAY NIGHT AS THE FRONT DROPS SOUTHEAST. WHILE THE DEEP LAYER SHEAR IMPROVES FRIDAY... THE INSTABILITY IS MARGINAL WITH SREF INDICATING UNIMPRESSIVE PROBABILITIES FOR CAPES OVER 2000 J/KG... SO WHILE ISOLATED SEVERE STORMS ARE POSSIBLE... LATEST INDICATIONS DO NOT FAVOR WIDESPREAD SEVERE WEATHER. LOWS 70 TO 75 AND HIGHS 87 TO 93... A CATEGORY BELOW THE MAV MOS GUIDANCE FOR HIGHS AND VERY CLOSE TO THE CURRENT FORECAST. TOTAL PRECIPITATION THROUGH FRIDAY NIGHT IN CENTRAL NORTH CAROLINA IS EXPECTED TO RANGE FROM A QUARTER TO THREE QUARTERS OF AN INCH. -GIH && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... HIGH PRESSURE NOSES INTO NORTH CAROLINA FROM THE NORTHWEST INTO MONDAY BEFORE WEAKENING IN FAVOR OF A WESTERN ATLANTIC HIGH. THE MID LEVEL LOW IS EXPECTED TO DRIFT EAST SOUTHEAST FROM PENNSYLVANIA BEFORE PLODDING NORTHEASTWARD INTO NEW ENGLAND BY TUESDAY. DURING THIS TIME THE GFS SWINGS WEAK LOBES OF VORTICITY AROUND THE TROUGH BASE THROUGH NORTH CAROLINA... THE MOST NOTABLE OF WHICH DROPS THROUGH LATE SUNDAY AND SUNDAY NIGHT... GENERATING PRECIPITATION OVER SOUTHWEST AND SOUTH CENTRAL NORTH CAROLINA. TIME SECTIONS SHOW A LIFT SOURCE AROUND 700 MILLIBAR ASSOCIATED WITH A LIKELY SPURIOUS VORTICITY MAXIMUM... AND WITH A GENERALLY DRY COLUMN AND FLOW... WILL CONTINUE WITH DRY WEATHER FOR THIS PERIOD. MID LEVEL HEIGHTS CONTINUE TO RISE OVER NORTH CAROLINA TUESDAY AND WEDNESDAY AS THE EASTERN NOAM TROUGH DEAMPLIFIES AND LIFTS EAST... WHILE THE ATLANTIC RIDGE BEGINS TO DOMINATE OUR WEATHER ANEW WITH RISING LOW LEVEL THICKNESSES TO ABOVE NORMAL VALUES. WITH A WEAK MID LEVEL SHEAR AXIS AGAIN SETTING UP FROM THE NORTH ATLANTIC TROUGH AND ACROSS NORTH CAROLINA TO A TEXAS LOW BY WEDNESDAY... WE SHOULD RETURN TO A NORMAL SUMMERTIME PATTERN WITH AFTERNOON CAPES NEARING 2000 J/KG AND ISOLATED AFTERNOON STORMS. CURRENT TREND OF TEMPERATURES RISING BACK TO ABOVE NORMAL BY WEDNESDAY STILL LOOKS QUITE GOOD. -GIH && .AVIATION /13Z THURSDAY THROUGH MONDAY/... LIMITED MOISTURE THIS MORNING SHOULD CURTAIL FOG DEVELOPMENT. THE EXCEPTION WILL BE THE EASTERN TAFS WHERE DEWPOINT SPREADS ARE A LITTLE CLOSER. MVFR VISIBILITIES POSSIBLE THROUGH 13Z AT RDU/FAY. IFR/LIFR CONDITIONS LIKELY THROUGH 13Z AT RWI IN STRATUS AND FOG. AFTER 13Z OVER THE TAF AREA... SCATTERED CLOUDS AT 5 THOUSAND FEET WITH SCATTERED TO BROKEN ALTOCUMULUS AT OR ABOVE 10 THOUSAND FEET. A SURFACE TROUGH WILL COMBINE WITH PRECIPITABLE WATERS VALUES AROUND 1.75 INCHES AND TEMPERATURES REACHING WELL INTO THE 90S TO PRODUCE SCATTERED AFTERNOON AND EVENING THUNDERSTORMS... WHICH WILL BE TIMED IN WITH LATER FORECAST. SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS ARE FORECAST THROUGH FRIDAY NIGHT. AREAS OF MVFR CONDITIONS IN FOG EACH MORNING AROUND DAWN. DRY CONDITIONS ARE FORECAST FOR SATURDAY INTO THE FIRST OF NEXT WEEK. -RHJ && .CLIMATE... RECORD HIGHS FOR TODAY (JULY 19): GSO - 98 - 1977 RDU - 99 - 1986 && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OH 910 PM EDT FRI JUL 20 2007 .SYNOPSIS... LARGE AREA OF HIGH PRESSURE MOVING SOUTH THROUGH THE GREAT LAKES WILL MOVE OVER THE AREA SATUARDAY AND DOMINATE THE WEATHER ACROSS THE AREA THROUGH THE WEEKEND. && .NEAR TERM /THROUGH SATURDAY/... CUMULUS OVER MUCH OF THE EASTERN FORECAST AREA HAS DECREASED FOR THE TIME BEING. CLOUDS OVER NORTHWEST OHIO CONTINUE AND WILL EVENTUALLY DECREASE AS THE VORT MAX THAT WAS CAUSING THEM MOVES SOUTH OF THE AREA. OVER THE NORTHEAST PORTION OF THE FORECAST AREA WITH THE LAKE AND 850 MB TEMPERATURE DIFFERENCE OVER 13C SOME LAKE EFFECT CLOUDS WILL DEVELOP OVERNIGHT. MOST MODELS ESPECIALLY THE NAM AND RUC INDICATE THIS. WILL FORECAST PARTLY CLOUDY OVER THE EASTERN AREAS. DID SOME MINOR ADJUSTMENTS TO THE MINIMUM TEMPERATURES BASED ON THE LOW DEWPOINTS LATE THIS AFTERNOON. ONLY A FEW LOCATIONS WILL BE CLOSE TO RECORD LOWS. HIGH PRESSURE BUILDING OVERHEAD FOR SATURDAY SO EXPECT A SUNNY START ACROSS THE AREA. HOWEVER...WITH H850 TEMPS AROUND 8-9C AND CU RULE ANALYSIS... EXPECT CU TO POP UP AGAIN FROM LATE MORNING ON ESPECIALLY ACROSS THE EASTERN HALF OF THE FORECAST AREA. TEMPS WILL AGAIN RANGE MAINLY IN THE 70S ACROSS THE AREA TOMORROW WITH THE COOLEST TEMPS ACROSS NE OH/NW PA WHERE CU FIELD IS EXPECTED. OTHERWISE EXPECTING DRY CONDITIONS. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... SURFACE HIGH PRESSURE WILL CONTINUE TO DOMINATE ACROSS THE AREA FROM SATURDAY NIGHT INTO SUNDAY. AT THIS TIME EXPECTING DRY CONDITIONS TO CONTINUE THROUGH SUNDAY ACROSS THE AREA WITH TEMPS WARMING SLIGHTLY BY THE END OF THE WEEKEND. BY MONDAY...BOTH NAM AND GFS BEGINNING TO SHOW UPPER LOW BEGINNING TO CLOSE OFF OVER THE CENTRAL APPALACHIANS AND SURFACE HIGH PRESSURE WEAKENING OVER THE AREA. WITH LOW EXPECTED TO BEGIN CLOSING OFF EAST OF THE AREA KEPT MONDAY DRY ESPECIALLY FOR WESTERN AREAS. CONTINUED TO TREND TOWARDS WARMER TEMPS...INTO THE UPPER 70S TO LOWER 80S BUT WILL HAVE TO WATCH FOR CLOUD COVER ACROSS THE AREA AT THIS TIME. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... FEATURE THAT WILL HAVE TO BE WATCH DURING THIS TIME PERIOD WILL BE A CLOSED OFF UPPER LOW THAT IS EXPECTED TO LINGER ACROSS THE AREA THROUGH LATE IN THE WEEK. EARLIER RUN OF THE GFS THIS MORNING BEGAN TO SHOW UPPER LOW LINGER ACROSS THE CENTRAL APPALACHIANS WITH A SLIGHT RETROGRADE WEST. LOOKING AT THE ECMWF RUNS THERE WAS QUITE A ABRUPT SHIFT WITH EARLIER RUNS KEEPING THE UPPER LOW WELL TO THE EAST OF THE AREA...THEN SHIFTING THE LOW BACK WEST TOWARDS SW OH. LATEST 12Z GFS NOW SHIFTS THIS UPPER LOW EVEN FURTHER BACK TO THE WEST. EVEN 12Z NAM HINTING AT THIS TREND. GIVEN THAT THIS IS A RELATIVELY NEW INDICATION OF GUIDANCE IN THE LONGER TERM...DID MENTION SOME SLIGHT CHANCE POPS ACROSS THE AREA IN THE GRIDS BEGINNING ON TUE. GFSX INDICATING A BIT HIGHER POPS FROM TUE ON...BUT WOULD LIKE TO SEE SOME MORE RUN TO RUN CONSISTENCY OVER THE NEXT DAY OR SO BEFORE INCREASING POPS. AS FOR TEMPS THROUGH THE PERIOD REMAINED CLOSE TO GUIDANCE VALUES...BUT DID TREND FORECAST TEMPS DOWN A BIT DURING THE PERIOD GIVEN THE POSSIBILITY OF MORE CLOUDS AND SHRA/TSTM ACROSS THE AREA. && .AVIATION /01Z SATURDAY THROUGH WEDNESDAY/... VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST PERIOD. LARGE SFC HIGH CENTERED OVER WISCONSIN WILL REMAIN NEARLY STATIONARY NEXT 24 HOURS. EXPECT SOME LINGERING SCT040-060 AS AN UPPER LEVEL TROUGH SWINGS ACROSS THE AREA TONIGHT. COULD ALSO SEE SOME LAKE EFFECT CLOUDS DEVELOP AND PUSH INLAND FROM CLEVELAND EAST. EXPECT LIGHT N-NE FLO OVERNIGHT. HIGH PRES WILL REMAIN OVER THE AREA THRU TUESDAY. AN UPPER LEVEL DISTURBANCE MAY BRING A SLIGHT CHANCE OF PRECIPITATION TO NW PA AND EASTERN OHIO WEDNESDAY. ALSO WATCH FOR SOME PATCHY FOG ESPECIALLY SATURDAY MORNING AND MAYBE EVEN SUNDAY MORNING AS WINDS GO LIGHT AND SOME POCKETS OF LEFT OVER LOW LEVEL MOISTURE. && .MARINE... COLD ADVECTION BEHIND THE FRONT CONTINUES THIS AFTERNOON...HOWEVER WINDS HAVE REMAINED MARGINAL FOR SMALL CRAFT ADVISORY SINCE 16Z. THINK THAT THE WINDS WILL CONTINUE TO BE ON THE DECREASE THIS AFTERNOON AND EVENING...BUT WILL LET THE SMALL CRAFT ADVISORY CONTINUE TIL 4AM AND EXPIRE AS SCHEDULED. HIGH PRESSURE BUILDS OVER THE LAKE TOMORROW AND WILL REMAIN IN PLACE THROUGH THE MIDDLE OF NEXT WEEK. WINDS SHOULD REMAIN LIGHT AND VARIABLE ON THE LAKE THROUGH THE MIDDLE OF NEXT WEEK DESPITE WIDELY VARYING MODEL SOLUTIONS. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR LEZ142>149. && $$ SYNOPSIS...ABE NEAR TERM...KIELTYKA SHORT TERM...ABE LONG TERM...ABE AVIATION...DJB MARINE...LEINS oh AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE ABERDEEN SD 946 AM CDT FRI JUL 20 2007 .UPDATE... MORNING UPDATE INCLUDES A NUDGING OF MAX TEMPERATURE UPWARDS BY 2 TO 4 DEGREES ACROSS THE WESTERN THIRD OF THE FORECAST AREA. STILL LOOKS LIKE PLENTIFUL SUNSHINE TODAY...AS LOW STRATUS DECK /INFERRING LOW LEVEL MOISTURE RETURN/ LIFTING UP ACROSS SOUTHWEST AND SOUTH CENTRAL SOUTH DAKOTA FROM NEBRASKA IS EXPECTED TO DISSIPATE THIS MORNING AS BOUNDARY LAYER MIXING PICKS UP IN EARNEST. LATEST RUC/NAM DATASETS SUPPORT LOW TO MID 90S /AT MINIMUM/ OUT ACROSS THE WEST RIVER COUNTIES OF CORSON...DEWEY...STANLEY...JONES AND LYMAN COUNTIES. STILL SOMEWHAT OF A CONCERN AS TO WHETHER SURFACE DEWPOINTS WILL SHOW A SUBSTANTIVE DROP LATER THIS AFTERNOON AS THOSE 90 DEGREE TEMPERATURES BEGIN TO BE REALIZED...RESULTING IN LOWER RELATIVE HUMIDITIES THAN ARE CURRENTLY BEING FORECAST /NAMELY...RH VALUES IN THE LOWER 20S INSTEAD OF THE LOWER 30S/. NO RED FLAG WARNINGS AT THIS TIME...BUT WILL CONTINUE TO MONITOR THE NEED FOR ONE. && .PREV DISCUSSION... .SHORT TERM...TODAY THROUGH SUNDAY NIGHT. ALL MODELS IN EXCELLENT AGREEMENT ON THE 500HPA RIDGE MOVING OVER THE REGION TODAY FOR THE BEGINNING OF WHAT APPEARS TO BE AN EXTENDED HOT AND DRY PERIOD FOR THE NORTHERN PLAINS. THUS...NOT MUCH TO TALK ABOUT THIS MORNING. A SURFACE HIGH REMAINS OVER THE GREAT LAKES TODAY THROUGH SUNDAY MORNING BEFORE MIGRATING TO THE EAST...WITH SOUTHERLY WINDS BETWEEN THE HIGH AND A LOW PRESSURE TROUGH TO THE WEST HELPING TO BRING HOT AND MORE HUMID AIR BACK TO THE REGION THROUGH THE WEEKEND. THE 00Z NAM CONTINUES TO SHOW MOISTURE STREAMING NORTHWARD TONIGHT THROUGH TOMORROW MORNING ON THE HEELS OF WARM AIR ADVECTION...WITH THE GFS NOW IN BETTER AGREEMENT...AND THUS INCREASED CLOUD COVER IN THE SOUTHERN/EASTERN SECTIONS OF THE CWA FROM TONIGHT THROUGH SATURDAY AS THIS MOISTURE HANGS AROUND THE FAR EAST THROUGHOUT THE DAY ON SATURDAY. OTHERWISE...CURRENT WARMING TREND STILL LOOKS GOOD...THOUGH RAISED HIGHS JUST A TAD ON SUNDAY AS 500HPA HEIGHTS RISE TO 594 TO 596 DECAMETERS AND 850MB TEMPERATURES SOAR TO 24C TO 31C BY EARLY SUNDAY EVENING. GUIDANCE CONTINUES TO INCREASE HIGHS AS WELL. ONLY CONCERN WITH THIS SEEMS TO BE THAT MODEL INDICATIONS CONTINUE TO POINT TO DEW POINTS IN THE UPPER 60S TO LOWER 70S AND SOUTH/SOUTHEAST WINDS...NOT THE GREATEST SETUP FOR VERY HOT CONDITIONS...BUT WITH VERY WARM AIR ALOFT EVEN FOR LATE JULY...DO NOT NECESSARILY NEED THE IDEAL SETUP TO GET NEAR 100 TO 105 IN MANY AREAS ACROSS THE CWA...BUT WILL CONTINUE TO MONITOR. SHOULD FORECAST PAN OUT AS CURRENTLY INDICATED...HEAT INDICES WILL REACH TO NEAR 105 OR A LITTLE HIGHER ACROSS MOST OF THE CWA DURING PEAK HEATING ON SUNDAY. HOWEVER...DEW POINTS COULD FALL A BIT IN THE AFTERNOON AS TEMPERATURES WARM. .LONG TERM...MONDAY THROUGH WEDNESDAY MORNING MEDIUM RANGE MODELS CONTINUE TO DEPICT A STRONG WESTERN RIDGE WITH A CLOSED HIGH OVER THE NORTHERN PLAINS. HIGH H5 HEIGHTS WILL EQUATE TO A HOT AND STAGNANT PATTERN. CONTINUED TEMPERATURE GRIDS PUSHING 100 DEGREE MARK FOR LARGE PARTS OF CENTRAL SOUTH DAKOTA. ALSO NIGHT TIME TEMPERATURES WILL STAY WARM AS WELL. LITTLE CHANCE OF RAIN WITH THIS PATTERN. && .AVIATION... UPPER LEVEL RIDGING AND SURFACE HIGH PRESSURE CONTINUE ACROSS THE AREA...VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGHOUT THE PERIOD. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...DORN SHORT TERM...ECKSTEIN LONG TERM...KEEFE AVIATION...GIONTA sd AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 900 PM CDT FRI JUL 20 2007 .DISCUSSION...SATELLITE AND RADAR IMAGES INDICATE MOST OF THE CONVECTION HAS SHIFTED WESTWARD ACROSS SOUTHWEST TEXAS AND THE RIO GRANDE PLAINS THIS EVENING. 500MB PRESSURE HEIGHTS HAVE RISEN ACROSS THE CWA AND THIS APPEARS TO BE KEEPING A LID ON CONVECTION DEVELOPING ACROSS THE AREA FOR NOW. THE 18Z GFS AND NAM MODEL RUNS PROG SOME DRIER AIR FILTERING INTO SOUTHEAST TX SATURDAY. NOT WILLING TO AGREE WITH THESE LATEST MODEL RUNS AS OF YET BUT BELIEVE RAIN CHANCES MAY NOT BE AS WIDESPREAD TOMORROW AS THEY HAVE BEEN THE LAST COUPLE OF DAYS. PRECIPITABLE WATER VALUES REMAIN NEAR 2 INCHES ACROSS THE AREA AND RUC80 1000-500MB WIND STREAMLINE ANALYSIS INDICATED THAT MOISTURE OVER THE WESTERN GULF OF MEXICO CONTINUES TO ADVECT NORTHWARD INTO SOUTH TX. ALSO...LCH/CRP 00Z SOUNDINGS INDICATE AN UNSTABLE AIRMASS PERSISTS ACROSS THE AREA WITH LITTLE OR NO CAP. WILL GO AHEAD AND LOWER POPS TONIGHT FOR NOW. 32 && .PREV DISCUSSION... /ISSUED 730 PM CDT FRI JUL 20 2007/ AVIATION... WITH CONTINUED ONSHORE CONVERGENCE AT THE LOWER LEVELS AND WIDESPREAD SURFACE PRECIPITABLE WATER VALUES GREATER THAN 2.0 INCHES...HAVE ELECTED TO FOLLOW PERSISTENCE WITH THIS TAF PACKAGE. INLAND TAF SITES WILL EXPERIENCE PATCHY MVFR CIG CONDITIONS DURING EARLY MORNING HOURS (FOG/STRATUS)...FOLLOWED BY WIDESPEAD MVFR CONDITIONS AFTER 10-12Z (SH/TSRA). THE ATMOSPHERE WILL STABILIZE SOMEWHAT AFTER 18Z...SO MOST SITES WILL BE VFR IN THE AFTERNOON WITH VCSH CONDITIONS. THE 18Z MODEL GUIDANCE SUGGESTS A WESTWARD MOVEMENT OF THE SURFACE RIDGE THAT WOULD CAUSE CONDITIONS TO IMPROVE SOONER THAN REFLECTED THE THE TAFS. I DECIDED NOT TO JUMP ON THE MODEL BAND WAGON WITH ONLY ONE RUN. IF OBSERVED DATA AND THE 00Z MODEL RUN CONTINUE TO FALL IN LINE WITH 18Z MODEL RUNS...THE 06Z TAF PACKAGE MAY REFLECT THESE IMPROVING CONDITIONS. 44 PREV DISCUSSION.../ISSUED 219 PM CDT FRI JUL 20 2007/ CONVECTION HAS DIMINISHED OVER THE LAST COUPLE OF HOURS AS AIRMASS AS STABILIZED IN THE WAKE OF THE EARLY MORNING MCS. WILL KEEP 30 POPS GOING THROUGH THE EVENING...GIVEN THE POSSIBLE REDEVELOPMENT OF SCATTERED -SHRA AS THE CONVECTIVE TEMP IS REACHED. HEAVIER STORMS EXPECTED TO FORM OVER THE WATERS AGAIN AFTER MIDNIGHT AS WEAK LOW LEVEL CONVERGENCE DEVELOPS. THIS ACTIVITY COULD AFFECT AREAS MAINLY SOUTH OF I-10 BEGINNING LATE TONIGHT. MODELS SHOW LITTLE CHANGE FOR SATURDAY WITH PWS OF 2.0-2.2 INCHES...SIGNIFICANT DIFLUENCE AT 300 MB...NO CAPPING...AND CONVECTIVE TEMPS IN THE MID 80S. NUMEROUS STORMS EXPECTED AGAIN WITH THE POTENTIAL FOR LOCALLY HEAVY DOWNPOURS AND MINOR FLOODING. EXACT TIMING OF THE RAIN SOMEWHAT UNCERTAIN. IF THE BULK OF THE CONVECTION OCCURS IN THE MORNING THEN THE ATMOSPHERE COULD STABILIZE LEAVING THE CWA MOSTLY DRY IN THE AFTERNOON (SIMILAR TO TODAY). WILL MENTION POSSIBILITY OF LOCALLY HEAVY RAIN FOR SATURDAY IN THE HWOHGX. MODELS INDICATE A VERY MODEST DRYING TREND BEGINNING ON SUNDAY/MONDAY...WITH PWS DROPPING TO 1.7-1.9 INCHES. DESPITE THIS...THE ATMOSPHERE WILL REMAIN UNCAPPED WITH CONVECTIVE TEMPS IN THE MID 80S. GFS SHOWS THE WEAK BACKDOOR FRONT STALLING OVER EXTREME EAST TX SUNDAY/MONDAY...POSSIBLY SERVING AS AN ADDED FOCUS FOR CONVECTIVE DEVELOPMENT. FOR NOW...HAVE KEPT POPS AT 40 PCT BOTH DAYS. HAVE DISCOUNTED THE OUTLIER SOLUTION OF THE 12Z NAM WHICH SHOWS THE FRONT CROSSING THE CWA...AND SHARPLY LOWER PWS ON MONDAY. ALL THE MODELS SHOW DRYING TAKING PLACE ON TUESDAY...WITH PWS DROPPING TO AROUND 1.5 INCHES. STILL EXPECT SCATTERED TSRA TO DEVELOP TUESDAY...BUT COVERAGE SHOULD BE LOWER THAN PREVIOUS DAYS. WILL FCST ONLY 30 POPS TUESDAY...THE MOST OPTIMISTIC PART OF THE ENTIRE FORECAST. ALL THE MEDIUM RANGE MODELS SHOW ANOTHER WEAK 500 MB TROUGH SETTING UP ACROSS TEXAS BEGINNING WEDNESDAY...WITH THE LATEST GFS SHOWING ANOTHER SURGE OF 2 INCH PWS ARRIVING THURSDAY. MODELS HAVE BEEN CONSISTENT WITH THIS SCENARIO WHICH WOULD BRING A RETURN OF MORE WIDESPREAD CONVECTIVE DEVELOPMENT LATE NEXT WEEK INTO THE FOLLOWING WEEKEND. 35 MARINE... OUTFLOW WINDS FROM DECAYING CONVECTION HAS RESULTED IN VARIABLE WINDS OVER NEARSHORE WATERS EARLY THIS AFTERNOON. ONSHORE FLOW EXPECTED TO PREVAIL AGAIN THIS EVENING BECOMING 10 TO 15 KNOTS TOWARD MORNING. SHOWERS AND THUNDERSTORMS PROBABLY WILL INCREASE IN COVERAGE LATE TONIGHT AND THEN DECREASING BY MID DAY SATURDAY. WINDS BECOMING LIGHT LATE IN THE WEEKEND WITH WEAKENING PRESSURE GRADIENT. 37 CLIMATE... HOUSTON IAH HAS RECEIVED 1.12 INCHES OF RAIN TODAY WHICH BRINGS THE JULY RAINFALL TOTAL UP TO 8.11 INCHES. AS A RESULT...JULY 2007 NOW RANKS AS THE THE 9TH WETTEST JULY ON RECORD FOR HOUSTON. HOUSTON HAS SEEN MEASURABLE RAIN 14 DAYS THIS MONTH...AND 28 OUT OF THE LAST 37 DAYS. COLLEGE STATION AND GALVESTON ARE NOT IN THE TOP 10 RANKING YET. THE UNUSUALLY MILD TEMPERATURES DESERVE A MENTION AS WELL. THE NORMAL HIGH FOR TODAY IN HOUSTON IS 94 DEGREES. TYPICALLY HOUSTON HAS 90+ TEMPERATURES NEARLY EVERY DAY IN JULY...MID 90S FOR NEARLY HALF THE MONTH...AND EVEN A FEW DAYS IN THE UPPER 90S TO NEAR 100 DEGREES. IAH HAS RECORDED A 90+ DEGREE TEMPERATURE ONLY 8 DAYS SO FAR THIS MONTH...AND THE HIGHEST HAS BEEN ONLY 96 DEGREES. && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 72 87 73 90 72 / 10 60 30 40 20 HOUSTON (IAH) 73 88 74 90 73 / 20 60 30 40 20 GALVESTON (GLS) 77 87 78 87 78 / 20 60 20 30 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...32 AVIATION/MARINE...44 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 940 AM CDT FRI JUL 20 2007 .DISCUSSION...THE HVY RAIN THREAT HAS SHIFTED FURTHER NORTHEAST ACROSS THE UPPER TX COASTLINE THIS MORNING WITH ONLY SOME PATCHY LIGHT SHOWERS MOVING OVER ZAPATA COUNTY AT THE MOMENT. THE AIRMASS OVER DEEP SOUTH TEXAS REMAINS PRETTY MOIST AND UNSTABLE WITH THE 12Z BRO SOUNDING SHOWING A PWAT OF 2.14 INCHES AND A CAPE OF 5175 J/KG. ALTHOUGH MOST OF THE BRO CWA IS PCPN FREE THIS MORNING...DAYTIME HEATING WILL LIKELY HELP REDEVELOP MORE SCT CONV LATER THIS AFTERNOON AND THIS EVENING. MAV POP GUIDANCE IS MORE WET VERSUS THE MET NUMBERS. BUT IT APPEARS THAT THE GFS IS NOT INTIALIZING WELL ON THIS MORNINGS CONV OVER TX. THE NAM AND RUC GUIDANCE ALSO APPEAR TO SUFFER FROM INITIALIZATION/FEEDBACK PROBLEMS IN SHOWING WIDEPREAD CONV FURTHER WEST OVER SOUTH CENTRAL TX. SO WILL DEVIATE FROM ALL OF THE SHORT RANGE MODEL QPF FIELDS AND WILL REFLECT A MORE DIURNALLY DRIVEN POP/QPF FIELD FOR LATER THIS AFTERNOON AND EVENING. SO HAVE MADE SOME ADJUSTMENTS TO THE EXISTING GRID POP AND TEMP FIELDS. && .MARINE...BUOY020 REPORTED SSE WINDS AROUND 15 KTS AND SEAS AT 4 FT. A HIGH PRESSURE WILL PREVAIL OVER THE NORTHERN GULF OF MEXICO MAINTAINING LIGHT TO MODERATE WINDS EAST TO SOUTHEAST WINDS TODAY. A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS WILL REMAIN THROUGH THE WEEKEND WITH HIGHER WINDS AND SEAS IN THE VICINITY OF ANY CONVECTION. HIGH PRESSURE SHIFTS TO THE WESTERN GULF OVER THE WEEKEND WITH LIGHT WINDS AND SEAS THROUGH THE MIDDLE OF NEXT WEEK. && .AVIATION...FG CREATING MVFR VIS AND IFR CIGS FG ACROSS MUCH OF NRN AND WRN ZONES THIS AM. VFR CONDITIONS WITH MID AND HI CIGS WILL PREVAIL BY 16Z WITH TEMPO MVFR TO IFR CONDITIONS AS SCT SHRA/TSRA DEVELOP AND MOVE INLAND. && .BRO WATCHES/WARNINGS/ADVISORIES...NONE. && $$ THIS PRODUCT IS ALSO AVAILABLE ON OUR INTERNET WEB PAGE AT: HTTP://WWW.SRH.NOAA.GOV/BRO SYNOPTIC/GRIDS...60 MARINE/AVIATION...55 MESO...ABBOTT tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 800 PM CDT THU JUL 19 2007 .DISCUSSION...LAPS CAPE GUIDANCE SHOWS SOME DECENT INSTABILITY ALONG THE LOWER RGV AND DOWN SOUTH OVER NORTHEAST MEXICO WITH AROUND 1600 TO 2400 J/KG ALONG AND NORTH OF THE RIVER AND 2400 TO 3400 SOUTH OF THE RIVER OVER THE HIGHER TERRAIN OF NORTHEAST MEXICO. THIS IS RESULTING IN ONLY SOME ISOLD TO SCT CONV PERSISTING MAINLY TO THE WEST AND SOUTH OF THE BRO CWA THIS EVENING WITH THE HELP OF THE LATE AFTER HEATING AND THE TROPICAL AIRMASS WHICH THE 00Z BRO SOUNDING REPORTING A MOIST PWAT AROUND 2.25 INCHES. THE RUC AND NAM SHORT TERM GUIDANCE TONIGHT KEEP MINIMAL TO NIL PVA MOVING OVER THE BRO CWA WITH THE BROAD INVERTED 500 MB TROUGH AXIS POSITIONED TO OUR WEST. THE GFS KEEPS A FAIRLY STRONG POCKET OF VORTICITY MOVING UP NORTH JUST WEST OF THE BRO CWA AND THIS WILL LIKELY KEEP THE CURRENT CONV CONCENTRATED NEAR OR JUST WEST OF OUR FORECAST AREA. SO WILL ALLOW THE FLASH FLOOD WATCH TO EXPIRE AT 8 PM THIS EVENING. HOWEVER...WILL MAINTAIN THE MENTION OF SOME CONV CHCS OVERNIGHT FOR ANY DEVELOPMENT THAT MOVES AWAY FROM NORTHEAST MEXICO. OTHERWISE... THE NAM AND GFS MODELS CONTINUE TO DIMINISH THE POPS ACROSS DEEP SOUTH TEXAS OVER THE NEXT COUPLE OF DAYS WHICH WILL ALLOW THE SATURATED HYDRO CONDITIONS TO SLOWLY IMPROVE. SO WILL UPDATE THE CURRENT ZFP TO REMOVE THE FLASH FLOOD WATCH HEADLINE. NO OTHER CHANGES NEEDED AT THIS TIME. && .MARINE...AT 7PM BUOY 42020 REPORTED EAST WINDS AT 8 KNOTS AND 4- FOOT SEAS WITH A PERIOD OF 7 SECONDS. HIGH PRESSURE TO THE EAST AND LOW PRESSURE TO THE WEST OF THE AREA IS EXPECTED TO MAINTAIN A BIT OF A PRESSURE GRADIENT AND CONTINUE LIGHT TO MODERATE SOUTHEAST WINDS INTO THE WEEKEND. WAVEWATCH III MODEL GUIDANCE INDICATES SEAS WILL STAY NEAR PRESENT LEVELS DURING THIS TIME FRAME. AS HIGH PRESSURE BEGINS TO DOMINATE EARLY NEXT WEEK...A DECREASING PRESSURE GRADIENT WILL ALLOW WINDS TO WEAKEN. SEAS ARE EXPECTED TO FALL TO AROUND 2 FEET BY MIDWEEK. && .AVIATION...VFR CONDITIONS AND LIGHT WINDS ARE EXPECTED TO CONTINUE OVERNIGHT. SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN ON FRIDAY AFTERNOON ALONG WITH SOUTHEAST WINDS UP TO AROUND 15 KNOTS. && .BRO WATCHES/WARNINGS/ADVISORIES...NONE. && $$ THIS PRODUCT IS ALSO AVAILABLE ON OUR INTERNET WEB PAGE AT: HTTP://WWW.SRH.NOAA.GOV/BRO SYNOPTIC/GRIDS....60 MARINE/AVIATION...68 MESO...MARTINEZ tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPOKANE WA 415 AM PDT THU JUL 19 2007 .SYNOPSIS...SHOWERS AND THUNDERSTORMS WILL AFFECT EASTERN WASHINGTON AND NORTHERN IDAHO THIS MORNING AS A COLD FRONT MOVES THROUGH THE REGION. MORE SETTLED WEATHER WILL RETURN TO THE REGION TONIGHT AS HIGH PRESSURE BUILDS INTO THE INLAND NORTHWEST. && UPDATED AVIATION DISCUSSION AND INCREASED MORNING POPS FOR NE WA .DISCUSSION... THE THREAT OF SEVERE THUNDERSTORMS IS RAPIDLY DIMINISHING THIS MORNING. 10Z RUC ANALYSIS SHOWS THE COMPUTED CAPE FOR PARCELS LIFTED FROM THE 800-700MB LAYER IS MOVING EAST INTO MONTANA. STRONGER STORMS IN LATAH...BENEWAH...KOOTENAI...AND BOUNDARY COUNTIES BETWEEN 7-8Z WERE CLOSELY TIED TO THE MID LEVEL INSTABILITY AXIS. NOW THAT THE UPPER LEVEL DYNAMICS OVER WESTERN WASHINGTON IS BECOMING SEPARATED FROM THE BETTER INSTABILITY...A GENERAL DECREASE IN THUNDERSTORM COVERAGE IS EXPECTED. THE POST FRONTAL PRECIPITATION BAND IN EASTERN WASHINGTON SHOULD REMAIN INTACT THROUGH 15-18Z HOWEVER. A LAST MINUTE UPDATE TO INCREASE PRECIPITATION AND QPF WAS ADDED TO THE FORECAST FOR THE SPOKANE AND COLVILLE AREAS. GKOCH ISSUED 250 AM... TODAY AND TONIGHT...A STRONG BAROCLINIC ZONE IN THE MID LEVELS OVER EASTERN WASHINGTON AND EASTERN OREGON HAS PRODUCED A BAND OF SHOWERS AND THUNDERSTORMS EXTENDING FROM AROUND BAKER CITY TO THE CANADIAN BORDER. STORMS IN THE WARM SECTOR OVER THE PANHANDLE HAVE EXHIBITED STRONG TO SEVERE SIGNATURES ON THE RADAR BETWEEN 08Z AND 0930Z. REFLECTIVITIES BETWEEN 50-60DBZ TO 25KFT SUGGESTED THE POTENTIAL FOR LARGE HAIL...BUT GIVEN THE TIME OF NIGHT...GROUND TRUTH HAS BEEN HARD TO COME BY. SMALL BOWING SEGMENTS HAVE BEEN RACING TO THE NORTH BETWEEN 60-70MPH. PROLONGED DAMAGING WINDS HAVE PROBABLY NOT SURFACED GIVEN THE WAINING LOW LEVEL INSTABILITY...BUT IT HAS BEEN HARD TO IGNORE STORMS MOVING THAT FAST. ANY WIND THAT WOULD SURFACE FROM A STORM MOVING 65MPH WOULD LIKELY CAUSE DAMAGE. THE MAIN UPPER LOW WILL TRAVERSE THROUGH WESTERN WASHINGTON BETWEEN 12Z AND 20Z. THE COLD FRONT THAT HAS BEEN HUNG OVER EASTERN WASHINGTON WILL ACCELERATE EASTWARD BY LATE IN THE MORNING AS THE UPPER LOW MOVES NORTH. THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS THIS MORNING WILL BE EAST OF A LINE FROM MOSES LAKE TO REPUBLIC...ROUGHLY ALONG THE 700MB FRONT. BY THE AFTERNOON...THE BEST Q-VECTOR CONVERGENCE ASSOCIATED WITH THE UPPER TROUGH WILL BE FOCUSED INTO CANADA. COLD AIR ALOFT WILL HAVE THE POTENTIAL TO PRODUCE SOME WIDELY SCATTERED SHOWERS AND THUNDERSTORMS OVER THE NORTHERN PORTION OF THE EAST SLOPES FROM WENATCHEE TO OMAK. POINTS SOUTH AND EAST WILL LIKELY BE TOO STABLE FOR AFTERNOON CONVECTION. /GKOCH FRIDAY THROUGH WEDNESDAY NIGHT...ALTHOUGH MODELS ARE IN GENERAL AGREEMENT WITH REGARD TO THE SYNOPTIC EVOLUTION THROUGH THE PERIOD AS WELL AS PLACEMENT AND GENERAL TIMING OF CLOUD COVER AND QPF...GLOBAL GUIDANCE STILL SEEMS TO BE HAVING SOME DIFFICULTY WITH THE VERTICAL THERMAL STRUCTURE UNDER ANY POTENTIAL CLOUD LAYERS THROUGH THE PERIOD...MOST SPECIFICALLY FRIDAY AND SATURDAY. WITH THE GFS BEING A COLD OUTLIER EARLY IN THE PERIOD...THE NAM AND ECMWF HAVE CLUSTERED FAIRLY STRONGLY TO BE WARMER THAN THE GFS. DUE TO A SLIGHTLY SLOWER FORWARD TRANSLATION SPEED WITH UPPER DIVERGENCE AND UPPER RH/CLOUD FIELDS...THE NAM AND ECMWF ALLOW FOR MORE SIGNIFICANT DIURNAL RISES IN TEMPERATURES ACROSS THE EASTERN CWA FRIDAY AS A SYSTEM GLANCES THE NORTHWESTERN CWA. AS IT DOES SO...BETTER CHANCES FOR SHOWERS AND POSSIBLE THUNDERSTORMS WILL BE CENTERED FROM THE CASCADES THROUGH THE OKANOGAN HIGHLANDS AS A PRETTY DECENT Q-CONVERGENCE MAXIMUM SHIFTS NORTHEASTWARD ACROSS THE WESTERN FLANK OF THE RESIDENT RIDGE TO OUR EAST. WITH INCREASING CLOUDS THROUGH THE DAY FRIDAY...TEMPERATURES WILL BE HELD BACK FROM RECENT READINGS. BY THE WEEKEND...THE MODELS ARE TENDING TO AMPLIFYING THE PATTERN IN PLACE. THIS STILL LEAVES THE BULK OF THE CWA IN A PRECARIOUS POSITION FOR THE FORECAST. WHILE IT SEEMS COOLER AIR WILL INFILTRATE THE WESTERN CWA AS EVIDENCED BY SIGNIFICANTLY LOWER 850 MB TEMPERATURES ALONG THE CASCADES AND OKANOGAN VALLEY AREAS...850 MB TEMPERATURES SOAR INTO THE MID 20S OVER THE EASTERN CWA PER THE GFS AND ECMWF. AS A RESULT...THE MOST SIGNIFICANT CHANGES TO THE FORECAST WERE GENERALLY TO LOWER TEMPERATURES FROM RITZVILLE WESTWARD...WHILE LEAVING THE TEMPERATURES ACROSS THE EASTERN CWA LARGELY ALONE. /FRIES && .AVIATION... VFR CONDITIONS WILL BE THE PREVAILING CATEGORY OVER EASTERN WASHINGTON AND NORTHERN IDAHO THROUGH 12Z FRIDAY. SOME TEMPORARY MVFR CEILINGS AND VISIBILITIES ARE POSSIBLE IN THE SPOKANE AND COEUR D`ALENE AREAS THROUGH 17Z IN THE HEART OF A RAIN BAND THAT WILL LIFT TO THE NORTHEAST THIS MORNING. THE BAND OF RAIN WITH EMBEDDED THUNDER IS CLOSELY TIED TO A MID LEVEL FRONT. ONCE THE FRONT CLEARS THE IDAHO PANHANDLE LATE THIS MORNING...SOME WIDELY SCATTERED CONVECTIVE SHOWERS MAY POP UP AFTER 20Z OVER THE HIGH TERRAIN OF THE CASCADES AND NORTHERN MOUNTIANS OF WASHINGTON. /GKOCH && .PRELIMINARY POINT TEMPS/POPS... SPOKANE 79 56 80 57 86 58 / 60 10 10 10 10 10 COEUR D`ALENE 81 52 83 54 86 58 / 60 10 10 10 10 10 PULLMAN 78 49 83 52 85 54 / 60 10 10 10 10 10 LEWISTON 86 60 90 64 94 62 / 60 10 10 10 10 10 COLVILLE 76 52 80 53 84 56 / 60 10 20 10 10 10 SANDPOINT 79 53 83 54 85 54 / 60 10 10 10 10 10 KELLOGG 83 54 86 56 88 57 / 60 10 10 10 10 10 MOSES LAKE 84 58 80 58 85 60 / 20 10 10 10 10 10 WENATCHEE 82 61 76 61 83 61 / 20 10 20 10 10 10 OMAK 81 55 78 58 80 60 / 20 20 20 10 10 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...NONE. WA...NONE. && $$ wa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 255 AM CDT THU JUL 19 2007 .DISCUSSION...FORECAST FOCUS IS ON QUIET WEATHER TODAY THROUGH MONDAY. MODELS ARE IN VERY GOOD AGREEMENT WITH SYNOPTIC SITUATION FOR THE NEXT SEVERAL DAY. THE COLUMN DRIES OUT TODAY WITH STRONG SUBSIDENCE...AND THESE CONDITIONS PERSIST THROUGH MONDAY. DRY CANADIAN RIDGE GRADUALLY SETTLES OVER THE WESTERN GREAT LAKES REGION. THE ONLY PROBLEM MAY BE SOME ISOLATED SHOWERS EARLY THIS MORNING. RADAR LOOPS SHOW ALL ORGANIZED CONVECTION WELL SOUTH OF CWA AT THIS TIME...BUT AN ISOLATED SHOWERS OR TWO CONTINUES TO POP UP AT TIMES THEN DISSIPATES. RUC AND LAPS CONTINUE TO SHOW INSTABILITY ACROSS SOUTHERN WISCONSIN BUT THERE IS NOTHING TO FOCUS DEVELOPMENT. DEW POINTS ARE SLOWLY LOWERING FROM THE NORTH AND THE AIRMASS WILL CONTINUE TO BECOME MORE STABLE. AT THIS TIME...I WILL LEAVE RAIN OUT OF THE FORECAST FOR TODAY SUBJECT TO LAST MINUTE CHANGES. && .AVIATION...LOW PRESSURE TO MOVE EAST OF THE AREA THIS MORNING. WEAK ONSHORE FLOW HAS BROUGHT DENSE FOG AND LOW CLOUDS TO AREAS NEAR THE LAKE...INCLUDING THE KMKE TAF. COULD SEE SOME FOG AT KMSN AS WELL THIS MORNING IN WEAK FLOW. STRONG COLD FRONT TO SWEEP THROUGH THE AREA DURING THE MORNING AND SHOULD SCOUR OUT KMKE BY 14Z TO 15Z. DRIER CANADIAN AIRMASS TO BRING SCT CLOUDS TO THE AREA DURING THE AFTERNOON. && .MKX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 35/05 wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 300 AM CDT SAT JUL 21 2007 .DISCUSSION... 300 AM CDT NOT A WHOLE LOT OF CHANGES IN STORE FOR THIS SET OF ZONES/GRIDS AS THE WEATHER SCENARIO HAS NOT CHANGED MUCH...ESPECIALLY OVER THE SHORT TERM. WITH THE DEEP TROF OUT EAST AND AN AMPLIFIED RIDGE OUT WEST...OUR REGION IS CAUGHT IN THE MIDDLE WITH NORTHERLY FLOW FUNNELING DOWN INTO THE LAKES WITH A SFC HIGH PARKED OVER NORTHERN LAKE MICHIGAN. THIS HIGH WILL EVENTUALLY PROPAGATE SOUTHEASTWARD THROUGH THE LAKES AND BRING ON A WARMING TREND THROUGH NEXT WEEK AS WINDS SHIFT FROM BEING NE/E TO SE/S. THE H5 RIDGE THEN STARTS TO TILT NORTHEASTWARD INTO THE REGION FROM THE WEST EARLY NEXT WEEK AND THIS IS WHERE WE START TO SEE SOME MODEL DIFFERENCES...PUTTING IT LIGHTLY. THE SOUTHERN PORTION OF THE DEEP MID-LEVEL TROUGH OUT EAST CLOSES OFF AND STARTS TO RETROGRADE WESTWARD STARTING ON SUNDAY. HOW FAR WEST THE CLOSED LOW GETS IS WHERE THE MODELS START TO DEVIATE. THE TREND SEEMS TO BE FAVORING THE GFS PROGRESSION WHERE THE CLOSED LOW GETS INTO EASTERN OHIO...BUT THEN GETS PICKED UP BY THE FLOW AND STAYS CLEAR OF OUR AREA. THE DIFFERENCES BETWEEN THE RUNS CAN BE NOTED ON THE ECMWF RUNS ON THE 12Z FROM THE 20TH AND THE MORE RECENT 00Z RUN. THE 12Z RUN HAD THE CLOSED LOW MAKING IT TO EASTERN NEBRASKA BY THE END OF THE WEEK...WHILE THE NEW 00Z RUN TRENDS TOWARD THE GFS WITH THE VORT MAX GOING OVER LAKE ERIE AND LIFTING NORTH. THE 00Z NOGAPS AND UKMET ALSO SHOW A SIMILAR SOLUTION WITH THE NAM/DGEX AND CANADIAN BEING OUTLIERS ATTM WITH THE NAM/DGEX BRINGING THE TROF THRU MISSOURI AND THE CANADIAN BRINGING IT THRU MINNESOTA. THESE MODELS THAT SHOW THE FURTHER WESTWARD PROPAGATION ALL HAVE LOWER H5 HEIGHTS IN THE SOUTHERN PLAINS...WHICH ALLOW FOR THE CLOSED LOW TO PROPAGATE WESTWARD WITH LITTLE FORCE. SO...AM GOING ALONG WITH THE GFS/NOGAPS/UKMET/00Z EURO SOLUTIONS AND HAVE NOT MADE ANY ADJUSTMENTS TO THE EXTENDED FORECAST AS PREVIOUS THINKING WAS THAT THE CLOSED LOW WOULD ONLY MAKE IT TO INDIANA AND THIS GOES ALONG WELL WITH HPCS GUIDANCE. HALBACH && .AVIATION... FOR THE 0600 UTC TAFS...VFR CONDITIONS ARE EXPECTED THROUGH THIS TAF CYCLE. OVERNIGHT LIGHT WINDS MAY HAVE A TENDENCY TO BACK A BIT TO LIGHT NW AS INCREASING THERMAL DIFFERENTIAL COULD LEAD TO A WEAK LAND BREEZE DEVELOPING TOWARD SUNRISE...HOWEVER VELOCITIES WILL REMAIN LIGHT. WRF/RUC FORECAST SOUNDINGS BOTH SUGGEST THAT 950-900MB TEMPS WILL BE 2-3C WARMER THAN THURS MORNING SO THINK THE CHANCES OF LAKE EFFECT CLOUDINESS DEVELOPING AGAIN THIS MORNING IS NOT ALL THAT GREAT. SOME MID LEVEL CLOUDINESS COULD SPREAD INTO THE AREA LATER THIS MORNING INTO THE AFTERNOON HOURS AS GFS/WRF BOTH SUGGEST SOME WEAK SHORTWAVE ENERGY CRESTING THE HIGH AMPLITUDE RIDGE AND DROPPING SSW INTO THE GREAT LAKES REGION...HOWEVER ANY CLOUDINESS WOULD LIKELY REMAIN AOA FL100. WINDS SHOULD TEND TO VEER TO ENE BY LATE MORNING AS SYNOPTIC GRADIENT GETS A BIT OF A BOOST FROM THE LAKE DURING THE DAY TODAY. IZZI && .MARINE... 230 AM CDT HIGH PRESSURE OVER THE LAKE WILL EVER SO SLOWLY MIGRATE SE OVER THE NEXT FEW DAYS WITH WINDS OVER THE LAKE LARGELY GOVERNED BY DIURNAL LAND/SEA BREEZE CIRCULATIONS. WAVES FINALLY SUBSIDING OVER THE SOUTH END OF THE LAKE AFTER BEING STIRRED UP BY THE STRONG WINDS THE LAST COUPLE DAYS...AND WITH MAINLY LIGHT WINDS OVER THE LAKE LOOK FOR A CONTINUATION OF RELATIVELY LITTLE WAVE ACTION THROUGH MID WEEK. IZZI && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 1227 AM CDT SAT JUL 21 2007 .DISCUSSION... 235 PM CDT SOME AFTN CU SUPPLIED BY LAKE MSTR WILL DISSIPATE AT SUNSET TO ANOTHER CLEAR NIGHT. WINDS DROPPING OFF TO L/V OVERNIGHT BUT WILL RESIST ANY FOG MENTION. LIKELY TO BE SOME SHALLOW GROUND FOG NEAR DAYBREAK BUT NOT RESTRICTIVE TO MOTORISTS OR MOST AVIATION. STRONG HIGH PRESSURE BLDG ACROSS THE LAKES TONIGHT AND SAT WILL MAINTAIN NE FLOW OVER AREA AND LIKELY TO SEE SOME SCT CU AGAIN SAT WITH DIURNAL HEATING. WEAKER SFC FLOW OFF LAKE SUNDAY ALONG WITH VEERING TO EAST TO SE SHUD ALLOW WARMER TEMPS TO NEAR 80. TREND IN THE PAST FEW RUNS HAS BEEN TO GRADUALLY WARM UP INTO THE 90S BY MID WEEK. HOWEVER LASTEST RUN INDICATING UPR LOW INTENSIFICATION OVER MID APPALACHIANS LIKELY TO KEEP COOL NORTH FLOW ALOFT OVER AREA. THUS KEEPING SEASONABLE TEMPS IN PLACE EARLY IN WEEK. THIS UPR LOW TAKING A RETROGRADE MOTION WESTWARD ALONG THE UPR OHIO VLY MONDAY AND TUESDAY...TO THE LOWER OHIO VLY WEDNESDAY. GFS HAS GONE SO FAR AS TO TAKE IT NORTH OF STL THURS INTO SRN IOWA FRIDAY. RETROGRESSION SUPPORTED BY NAM AND ECMWF ALTHO TO VARYING DEGREES. WOULD PREFER TO CURB THE WESTWARD PROGRESS PERHAPS INTO INDIANA BY FRIDAY WHICH WUD CALL FOR INCREASING CLOUD COVER TOWARD THE END OF THE WEEK WITH INCREASING CHANCES OF RAIN TO OUR EAST AS MSTR DRAWS UP FROM THE GULF. FOR THE MOMENT...AM LEAVING THE LATTER HALF OF THE WEEK DRY IN HOPES OF AVOIDING A PROBABLE FLIP-FLOP FORECAST. HAVE HOWEVER CURBED HIGH TEMPS A BIT FROM PREVIOUS RUN IN EXTENDED IN ANTICIPATION OF INCREASED CLOUD COVER. WILL LOOK AT SITUATION THRU THE WEEKEND TO MONITOR RUN TO RUN CONSISTENCY. IF CONFIDENCE BECOMES MORE CONCRETE ...WILL LIKELY BE PUTTING IN CHANCE POPS IN LATTER PERIODS. RLB && .AVIATION... FOR THE 0600 UTC TAFS...VFR CONDITIONS ARE EXPECTED THROUGH THIS TAF CYCLE. OVERNIGHT LIGHT WINDS MAY HAVE A TENDENCY TO BACK A BIT TO LIGHT NW AS INCREASING THERMAL DIFFERENTIAL COULD LEAD TO A WEAK LAND BREEZE DEVELOPING TOWARD SUNRISE...HOWEVER VELOCITIES WILL REMAIN LIGHT. WRF/RUC FORECAST SOUNDINGS BOTH SUGGEST THAT 950-900MB TEMPS WILL BE 2-3C WARMER THAN THURS MORNING SO THINK THE CHANCES OF LAKE EFFECT CLOUDINESS DEVELOPING AGAIN THIS MORNING IS NOT ALL THAT GREAT. SOME MID LEVEL CLOUDINESS COULD SPREAD INTO THE AREA LATER THIS MORNING INTO THE AFTERNOON HOURS AS GFS/WRF BOTH SUGGEST SOME WEAK SHORTWAVE ENERGY CRESTING THE HIGH AMPLITUDE RIDGE AND DROPPING SSW INTO THE GREAT LAKES REGION...HOWEVER ANY CLOUDINESS WOULD LIKELY REMAIN AOA FL100. WINDS SHOULD TEND TO VEER TO ENE BY LATE MORNING AS SYNOPTIC GRADIENT GETS A BIT OF A BOOST FROM THE LAKE DURING THE DAY TODAY. IZZI && .MARINE... 240 PM CDT MAIN FEATURE THROUGH THE FORECAST PERIOD WILL BE THE BROAD ANTICYCLONE ACROSS THE WESTERN GREAT LAKES THAT WILL GRADUALLY SHIFT INTO THE EASTERN GREAT LAKES THIS WEEKEND. THE MOVEMENT OF THIS RIDGE OF HIGH PRESSURE WILL ALLOW FOR THE NORTH AND NORTHEAST WINDS TO SHIFT TO THE EAST AND SOUTHEAST TOMORROW NIGHT INTO SUNDAY. THE SURFACE PRESSURE GRADIENT WILL BE QUITE WEAK UNDER THE INFLUENCE OF THIS HIGH SO WINDS SHOULD BE NO GREATER THAN 10 TO 15 KNOTS THROUGH THE WEEKEND. THE RIDGE OF HIGH PRESSURE WILL EVENTUALLY REACH NEW ENGLAND BY SUNDAY NIGHT. HOWEVER...LATEST MODEL GUIDANCE IS COMING INTO GENERAL AGREEMENT IN HIGHLIGHTING A RETROGRADING UPPER AIR PATTERN WHICH WOULD ACT TO SHIFT THIS RIDGE OF HIGH PRESSURE BACK WESTWARD ACROSS THE EASTERN GREAT LAKES EARLY NEXT WEEK. AS A RESULT...A PERIOD OF LIGHT SOUTH/SOUTHWEST WINDS IS EXPECTED EARLY NEXT WEEK. IN TERMS OF THE NEARSHORE WATERS...WAVE HEIGHTS WILL DIMINISH THIS EVENING...ALTHOUGH A FEW MORE HOURS OF WAVES AT SMALL CRAFT ADVISORY CRITERIA ARE POSSIBLE THIS EVENING. ON SATURDAY...ONSHORE WINDS OF AROUND 10 KNOTS ARE EXPECTED. MARSILI && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 305 AM CDT SAT JUL 21 2007 .SHORT TERM /TODAY/... MID LEVEL CLOUDS HAVE DEVELOPED ACROSS WESTERN IOWA IN RESPONSE TO A BAND OF THETA-E ADVECTION. IN THE NEAR TERM...THE NAM IS SPREADING SOME SHOWERS INTO THE SOUTHWEST COUNTIES...WHILE THE RUC/GFS KEEP ANY PRECIP OUT OF THE FORECAST AREA EARLY THIS MORNING. LATEST RADAR TRENDS INDICATE A LIGHT SHOWER STARTING TO POP UP IN EXTREME SW IA NEAR PLATTSMOUTH AND WL CONTINUE TO MONITOR FOR POSSIBLE INCLUSION OF POPS TOWARD ISSUANCE TIME. OTHERWISE...FLOW AROUND THE GREAT LAKES HIGH WILL TURN MORE SOUTHEASTERLY TODAY AND TEMPS SHOULD BE A FEW DEGREES WARMER THAN YESTERDAY...BUT STILL BELOW NORMAL. LINGERING CLOUDS IN THE WEST MAY TEMPER THE WARMUP THERE DESPITE STRONGER SOUTHERLY FLOW. .LONG TERM /TONIGHT-FRIDAY/... AGAIN...LITTLE CHANGE MADE TO GOING FORECAST. STRONG UPPER LEVEL RIDGE CENTERED OVER THE ROCKIES BUT WITH AN AXIS REACHING NORTHEAST ACROSS THE NRN PLAINS WILL REMAIN IN THAT POSITION OR MOVE SLIGHTLY EAST EARLY IN THE WEEK. MODELS HAVING A HARD TIME PICKING UP ON SHORTWAVES IN CLOCKWISE FLOW AROUND THE UPPER LEVEL HIGH PRESSURE RIDGE AND FIGURING OUT WHAT TO DO WITH THEM AS THEY MAKE THE SOUTHWESTWARD TURN OVR THE UPR MS VLY. THERE IS SOME AGREEMENT WITH RESPECT TO LOW TO MID LEVEL MOISTURE PLUME CURRENTLY OVR THE CENTRAL PLAINS EDGING EASTWARD ANT INTO WRN PORTIONS OF CENTRAL IA BY SUNDAY AFTN. HOWEVER...PROGRESS OF THAT PLUME EASTWARD FROM THERE IS QUESTIONABLE AT THIS TIME. SINCE CONFIDENCE IN POP FORECAST IS VERY LOW...WILL LEAVE FCST DRY. ONE THING MORE CERTAIN IS THAT THE SFC HIGH PRESSURE RIDGE OVR THE GREAT LAKES WILL CONTINUE TO SUPPORT DRIER AND SLIGHTLY COOLER THAN NORMAL AIR FOR MUCH OF CENTRAL IA. THOUGH WRN SECTIONS WILL BE FARTHEST FROM ITS INFLUENCE. AFTER SUNDAY...THE SFC HIGH SHIFTS FAR ENOUGH EAST TO ALLOW ADDITIONAL WARMING. LITTLE CHANGE EXPECTED THROUGH THE WEEK AS AIRMASS REMAINS FAIRLY HOMOGENEOUS. SOME SUGGESTION AMONG CANADIAN AND EURO MODELS THAT AN UPPER LEVEL CUTOFF LOW WILL OVR THE ERN CONUS EARLY THIS WEEK WILL RETROGRADE WESTWARD TOWARD IA. HOWEVER...LATEST ECMWF RUN IS NOW MOVING AWAY FROM THAT SCENARIO...TOWARD THE GFS AND GFS ENSEMBLE PREDICTION OF HIGH PRESSURE REMAINING ANCHORED OVER OUR REGION. && .AVIATION...21/06Z HIGH PRESSURE CONTINUES TO KEEP QUIET WX OVER THE AVIATION FORECAST POINTS. ONE SMALL CHANGE W/R/T LOCATIONS OVER FAR WESTERN IOWA AND WEST...A WARM FRONT OVER EASTERN NEBRASKA DOES INDICATE SOME WEAK LIFT WITH THE FEATURE AND SOME MID LEVEL CLOUD COVER SEEN IN THAT AREA. AN ISOLATED SHOWER IS QUITE POSSIBLE AFT 09Z IN FAR WRN IA AND EASTERN NEB. VFR COND AND DRY ELSEWHERE. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...KINNEY LONG TERM...MOYER AVIATION...FAB ia AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WICHITA KS 1149 PM CDT FRI JUL 20 2007 .AVIATION... FOR THE 06Z TAF SUITE...LITTLE CHANGE FROM PREVIOUS THOUGHTS. GENERALLY EXPECT VFR CONDITIONS THROUGH THE FORECAST VALID PERIOD. ISOLATED SHOWERS CONTINUE TO FESTER ACROSS A SMALL PART OF THE FLINT HILLS AND SOUTHEAST KANSAS. WILL MAINTAIN VCSH MENTION FOR KCNU. OTHERWISE CHANCES EVEN THROUGH SATURDAY WILL REMAIN RATHER LOW IN BOTH TIME AND SPACE...SO HAVE PRECLUDED MENTION IN ALL TAF SITES FOR NOW. KED && .PREV DISCUSSION... /ISSUED 631 PM CDT FRI JUL 20 2007/ UPDATE... RUC AND EXTRAPOLATED LAPS DATA SUGGEST A REMOTE CHANCE FOR A FEW STORMS AS FAR WEST AS ELLSWORTH TO HUTCH TO GREATER WICHITA UNTIL DARK. HOWEVER BETTER CHANCE FOR ISOLATED TO WIDELY SCATTERED STORMS TO CONTINUE THIS EVENING FOR THE FLINT HILLS AND SOUTHEAST KANSAS. KED AVIATION... FOR THE 00Z TAF SUITE...VFR CONDITIONS EXPECTED THROUGH THE FORECAST VALID TIME...OUTSIDE OF ISOLATED TO WIDELY SCATTERED CONVECTION. THE KCNU AND KSLN TAF SITES WILL BE MOST IMPACTED...MAINLY THIS EVENING WITH THE THUNDERSTORM ACTIVITY. KED PREV DISCUSSION... /ISSUED 248 PM CDT FRI JUL 20 2007/ DISCUSSION... FORECAST CHALLENGES ARE PRECIPITATION CHANCES TONIGHT AND TEMPERATURES FOR THE NEXT FEW DAYS. TONIGHT: CURRENT VISIBLE SATELLITE SHOWS CUMULUS DEVELOPMENT ACROSS MUCH OF KANSAS...AS WELL AS THE REMNANTS OF AN MCV OVER SOUTHWEST KANSAS. THE WARM FRONT THAT WAS ACROSS KANSAS YESTERDAY HAS WASHED OUT AND THERE ARE REALLY NO INDICATIONS OF A BOUNDARY ANYMORE. TEMPERATURES HAVE BEEN ABLE TO CLIMB A COUPLE DEGREES HIGHER THAN WE EXPECTED TODAY...BUT WERE STILL A FEW DEGREES BELOW NORMAL. A FEW SHOWERS AND THUNDERSTORMS DEVELOPED ALONG AN INSTABILITY AXIS THAT STRETCHES ACROSS SOUTHEAST KANSAS...BUT THEY QUICKLY WEAKENED. THIS TREND IS EXPECTED TO CONTINUE THROUGH THE NIGHT. PRECIPITATION CHANCES WERE TRIMMED BACK TO JUST SOUTHEAST KANSAS OVERNIGHT. SATURDAY-SUNDAY: SOUTHERLY TO SOUTHEASTERLY FLOW AT THE SURFACE CONTINUES THROUGH THE WEEKEND...AND MOISTURE TRANSPORT IS MAINLY FOCUSED INTO SOUTHWEST KANSAS. THERE REMAINS SOME WEAK FORCING IN THE MID-LEVELS ACROSS SOUTHEAST KANSAS...BUT CONFIDENCE IS LOW THAT MORE THAN AN ISOLATED STORM OR TWO WILL BE ABLE TO DEVELOP. 1000-850MB THICKNESSES SUPPORT AT OR SLIGHTLY BELOW NORMAL TEMPERATURES THROUGH THE WEEKEND...THEREFORE WE BROUGHT MAXIMUM TEMPERATURES DOWN JUST A BIT TO ACCOUNT FOR THIS AND THE FACT THAT IT HAS BEEN A STRUGGLE TO GET ABOVE THE LOW 90S ACROSS THE FORECAST AREA WITH THE EXCEPTION OF CENTRAL KANSAS THIS SUMMER. MONDAY-THURSDAY: UPPER RIDGE IN PLACE DURING THIS TIME...WITH DRY WEATHER EXPECTED. THERE ARE SOME HINTS AT SOME WEAK RIPPLES IN THE FLOW...HOWEVER WITH TIMING AND TRACK OF THESE IMPULSES SURE TO CHANGE QUITE A BIT IN THE NEXT FEW DAYS...OPTED TO KEEP THE FORECAST DRY FOR NOW. 1000-850MB THICKNESSES DO NOT SUPPORT MID-90S FOR MUCH OF THE FORECAST AREA...RATHER LOW 90S...SO WE LOWERED MAX TEMPERATURES A COUPLE DEGREES TO ACCOUNT FOR THIS ESPECIALLY GIVEN THE STRUGGLE WE HAVE HAD THIS YEAR TO MAKE IT ABOVE THE LOW 90S THIS YEAR. SCHRECK AVIATION...FOR 18Z TAF ISSUANCE LATEST RADAR LOOP IS SHOWING SEVERAL SHOWERS AND THUNDERSTORMS STARTING TO DEVELOP ALONG THE INSTABILITY AXIS STRETCHING FROM CHANUTE TOWARDS SALINA. WE HAVE INTRODUCED A TEMPO TSRA GROUP FOR THE CHANUTE TAF THIS AFTERNOON...BUT WE HAVE HELD OFF AT SALINA UNTIL WE SEE A LITTLE MORE EVIDENCE. THE REMAINDER OF THE TAF SITES WILL SEE MAINLY CUMULUS THIS AFTERNOON...BUT YOU CANNOT RULE OUT A STORM OR TWO IN THE VICINITY. THIS THUNDERSTORM ACTIVITY SHOULD BEGIN TO DIE OFF AFTER SUNSET. WE DID MENTION SOME PATCHY BR IN THE CHANUTE TAF TOWARDS SUNRISE SINCE THERE IS A LOT OF LOW LEVEL MOISTURE IN PLACE ALONG WITH SOME DECOUPLING ACCORDING TO THE GFS. COX && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 71 93 70 93 / 10 10 10 10 HUTCHINSON 70 93 70 93 / 10 10 10 10 NEWTON 70 92 69 93 / 10 10 10 10 ELDORADO 69 92 69 92 / 10 10 10 10 WINFIELD-KWLD 70 93 70 92 / 10 10 10 10 RUSSELL 69 93 70 95 / 10 0 10 10 GREAT BEND 69 94 70 94 / 10 10 10 10 SALINA 71 92 69 93 / 10 10 10 10 MCPHERSON 70 93 69 93 / 10 10 10 10 COFFEYVILLE 69 92 68 90 / 10 20 10 10 CHANUTE 68 91 67 90 / 10 20 10 10 IOLA 68 91 67 90 / 10 10 10 10 PARSONS-KPPF 69 92 68 90 / 10 20 10 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 457 AM EDT SAT JUL 21 2007 .DISCUSSION... THE MAIN FORECAST CONCERN DEALS WITH PCPN CHCS SUN NIGHT INTO TUE. WATER VAPOR LOOP...RUC ANALYSIS AND 00Z RAOB PLOTS SHOW AN AMPLIFIED UPR RIDGE BUILDING FROM THE PLAINS INTO THE WESTERN GREAT LAKES. AT THE SFC HIGH PRES IS CENTERED OVER ERN UPR MI MAINTAINING CLEAR SKIES ACROSS THE REGION EARLY THIS MORNING. SUNNY SKIES AND MIXING OF 850 MB TEMPS 12-14C WILL ALLOW INLAND HIGHS TO REACH THE UPR 70S AND LOWER 80S TODAY. WEAK PRES GRADIENT WITH THE PROXIMITY OF THE SFC HIGH WILL ALLOW FOR LAKE BREEZE CIRCULATIONS TO KEEP TEMPS SLIGHTLY COOLER NEAR THE GREAT LAKES SHORELINES. AS THE SFC HIGH SLIDES INTO THE LOWER GREAT LAKES...A BIT STRONGER SW FLOW WILL DEVELOP BEHIND IT OVER UPR MI TONIGHT. EXPECT THE LOWEST TEMPS (AROUND 50F) OVER THE INTERIOR SCNTRL AND E COUNTIES CLOSER TO WEAKER PRES GRADIENT AND LOWER PWAT AIR ASSOCIATED WITH HI PRES CENTER. LOOK FOR A MOSUNNY AND WARMER DAY ON SUN WITH ANTICYCLONIC SW FLOW AROUND HI PRES OVER LAKE HURON. H85 TEMPS FCST TO RISE TO 14C-16C...AND MIXING AOA 800 MB ON GFS FCST SDNGS SUPPORTS HI TEMPS PUSHING APPROACHING 85F OVER MUCH OF W AND CENTRAL UPR MI. MODERATION DOWNSTREAM OF LAKE MI WILL KEEP TEMPS A FEW DEGREES COOLER THERE. MODELS STILL PERSIST ON BRINGING STRONG 850 MB THETA-E ADVECTION AND HIGHER PWATS (> 1.5 INCHES) INTO WRN COUNTIES SUN NIGHT INTO MON AHEAD OF SHRTWV LOBE RIDING OVER TOP OF PLAINS RDG. KEPT GOING SLIGHT CHC POPS FOR THE WRN COUNTIES SUN NIGHT AND THEN SPREAD SLIGHT CHC POPS INTO CENTRAL AND ERN COUNTIES ON MON AS HIGHER PWAT/THETA-E AIR ADVANCE E. 00Z GFS/NAM AND CANADIAN MODELS ALL SEEM TO SUGGEST HIGHER PWAT/THETA-E AIR AND SFC BOUNDARY WILL LINGER INTO TUE WITH CUT-OFF LOW DRIFTING WWD INTO THE OH VALLEY/LWR GRT LKS. THUS...HAVE EXTENDED THE SLIGHT CHC POP FOR MON NIGHT INTO TUE EVENING ACROSS THE ENTIRE CWFA. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... MID LEVEL WAA/ISENTROPIC LIFT IS EXPECTED TO SUPPORT SOME MID/HIGH CLOUDS. WITH DRY SFC-700 MB LAYER IN PLACE ASSOCIATED WITH A SURFACE HIGH PRESSURE OVER THE WESTERN GREAT LAKES...VFR CONDITIONS WILL PREVAIL THROUGH SATURDAY. && .MARINE (FOR 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... HIGH PRESSURE OVER THE UPPER GREAT LAKES WILL BUILD ACROSS THE REST OF THE GREAT LAKES TODAY. LOW PRESSURE TROUGH MOVING ACROSS NORTHERN ONTARIO LATE SUN INTO SUN NIGHT MAY TEMPORARILY INCREASE PRESSURE GRADIENT ENOUGH TO ALLOW FOR S WINDS TO INCREASE ABOVE 20 KT ON EASTERN SECTIONS OF LK SUPERIOR. RELAXING GRADIENT ON MON WILL RESULT IN SOUTH TO SOUTHWEST WINDS LESS THAN 20 KT THROUGH THE MIDDLE OF NEXT WEEK. && $$ PUBLIC...VOSS AVIATION/MARINE ...JLA mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HASTINGS NE 402 AM CDT SAT JUL 21 2007 .DISCUSSION...PAST EVENING UPPER AIR DATA ALONG WITH EARLY MORNING WATER VAPOR IMAGERY CONTINUES TO SHOW A LARGE RIDGE SITTING ACROSS THE CENTRAL CONUS. SEVERAL SMALL BUT POTENT WAVES CAN BE SEEN ROTATING AROUND THE PERIPHERY OF THIS RIDGE. LATEST SURFACE ANALYSIS SHOWS A STATIONARY FRONT STRETCHING FROM SOUTHEAST KANSAS INTO WESTERN NEBRASKA. RUC ANALYSIS DATA SHOWS MODEST 850MB THETA-E ADVECTION EAST OF THE SURFACE FRONT WHICH CONTINUES TO TRIGGER SOME WEAK ISOLATED CONVECTION ACROSS EASTERN KS INTO WESTERN IA. A HOT AND GENERALLY DRY PATTERN WILL TAKE HOLD OF THE REGION TODAY INTO TONIGHT AS THE UPPER RIDGE REMAINS IN CONTROL OF THE AREA. THIS WILL ALLOW THE AFOREMENTIONED STATIONARY FRONT TO CONTINUE LIFTING SLOWLY NORTHEAST ACROSS THE REGION TODAY. ALTHOUGH LOW LEVEL FORCING ALONG THIS BOUNDARY WILL BE WEAK AT BEST...CAPE VALUES OF 1500-2000 J/KG ALONG WITH WEAK CAPPING COULD TRIGGER A FEW SHOWERS EAST OF A HEBRON TO BELOIT LINE THIS AFTERNOON TO EARLY EVENING. OTHERWISE...LOOK FOR STRATUS ACROSS PORTIONS OF THE REGION THIS MORNING TO SLOWLY GIVE WAY TO A MOSTLY CLEAR TO PARTLY CLOUDY SKY AS TEMPERATURES CLIMB INTO THE UPPER 80S TO MID 90S. SUNDAY IS THEN SHAPING UP TO BE ANOTHER HOT AND GENERALLY DRY DAY ACROSS THE AREA ALTHOUGH THE UPPER RIDGE IS SHOWN TO BEGIN RETROGRADING BACK INTO THE ROCKIES AND INTERMOUNTAIN WEST DURING THIS TIME FRAME. ALTHOUGH BETTER LOW LEVEL FORCING ON SUNDAY WILL REMAIN ACROSS THE HIGH PLAINS CLOSER TO THE LEE TROUGH...A SMALL BUT POTENT WAVE SLIDING SOUTH ALONG THE FRONT SIDE OF THE UPPER RIDGE MAY TRIGGER SOME ISOLATED CONVECTION. BEST CHANCE FOR THIS CONVECTION LOOKS TO BE EAST OF A YORK TO BELOIT LINE. WILL AIM FOR AFTERNOON HIGHS IN THE LOWER TO MID 90S. AS THE REGION HEADS INTO MONDAY THE UPPER RIDGE BEGINS TO BUILD BACK INTO THE NORTHERN PLAINS WHILE A POSITIVELY TITLED UPPER TROUGH OVER THE EASTERN CONUS BEGINS TO BACK INTO THE LOWER TO MID MS RIVER VALLEY. THIS WILL KEEP THE FORECAST AREA ON THE UNSETTLED EASTERN EDGE OF THE UPPER RIDGE. AS WAS THE CASE ON SUNDAY...IT APPEARS ANOTHER WAVE RIDING ALONG THE FRONT SIDE OF THE RIDGE COULD TRIGGER SOME ISOLATED CONVECTION EAST OF A YORK TO BELOIT LINE. AFTERNOON TEMPERATURES WILL ALSO BE SIMILAR WITH HIGHS VARYING FROM THE LOWER TO MID 90S. && .AVIATION...CONCERN WITH THIS TAF IS DEVELOPING STRATUS AND FOG. SATELLITE IMAGERY SHOWING STRATUS AREA TO THE NW OF OUR CWA IS EXPANDING SE. SHOULD END UP MVFR AND POSSIBLY IFR BEFORE SUNRISE. STILL HAVE GOOD TURBULENT MIXING IN LOWER LEVELS SO WHILE VSBYS MAY DROP TO 4 OR 5 MILES...DON`T THINK WE WILL GO LOWER. ALL THIS WILL BE SLOW TO MIX OUT AFTER SUNRISE DUE TO HIGH AMOUNT OF LOW LEVEL MOISTURE. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTH PLATTE NE 344 AM CDT SAT JUL 21 2007 .DISCUSSION... UPPER LEVEL RIDGE CONTINUES TO DOMINATE THE REGION...HOWEVER LOW LEVEL MOISTURE MAKING FOR A DIFFICULT FORECAST. MAIN CONCERNS LEAN ON LOW CLOUDS AND TEMPERATURES. WITH UPPER LEVEL RIDGE REALLY NOT GOING ANYWHERE THROUGH THE FORECAST PERIOD...THE SURFACE CONDITIONS ARE THE MAIN PLAYER. SOUTHEAST WINDS HAVE USHERED EVEN MORE MOISTURE OVERNIGHT WITH DEW PTS HOVERING CLOSE TO THE 70 DEGREE MARK. WINDS HAVE KEPT UP NEAR 10 KTS THUS TEMPS NOT FALLING NOR IS FOG BELOW 4SM BEEN ABLE TO FORM. STRATUS HAS DEVELOPED ACROSS MOST OF THE EASTERN HALF OF FA...PER SAT. EXPECT LITTLE CHANGE THROUGH THE MORNING. THEN COMES THE QUESTION OF HOW LONG WILL STRATUS STICK AROUND AND WHAT EFFECT THE HIGH SURF MOISTURE PLAYS ON ATMOSPHERE TO WARM. FOR SEVERAL DAYS NOW GUIDANCE HAS BEEN TOO WARM. SUSPECT THE GUIDANCE IS FOLLOWING SEVERAL YEARS OF DROUGHT CONDITIONS AND ALLOWING FOR MORE SURFACE HEATING THAT IS POSSIBLE WITH ALL THE SURF MOISTURE. THUS WILL CONTINUE TO GO TOWARDS THE LOWER GUIDANCE VALUES. EXCEPTION WILL BE ACROSS NW FA WHERE DRIER CONDITIONS EXIST AND CLOSER TO WARMER GUIDANCE. WEAK TROF ALONG THE FRONT RANGE AND UPSLOPE FLOW TO LIKELY CONTINUE TO FIRE STORMS TO OUR WEST. NAM SUGGEST A SLIGHT EASTWARD SHIFT OF THE TROF INTO THE NORTHERN PANHANDLE LATE IN THE DAY TOMORROW. WITH HIGH MOISTURE AND HIGH TEMPS...INSTABILITY IS GREAT...HOWEVER SO IS THE CAP AS TEMPS WARM ALOFT. WENT AHEAD AND ADDED LOW POPS...SLIGHT CHANCE...ACROSS NW ZONES. SHEAR IS WEAK SO NOT EXPECTING MUCH...IF ANY...ACTIVITY TO GET GOING TO BE VERY STRONG. REMAINDER OF THE WEEK CONTINUES TO SEE ABOVE TEMPS WITH LITTLE CHANCE FOR MOISTURE. TEMPS ALOFT TO KEEP A DECENT CAP...HOWEVER LL MOISTURE COULD SEE SOME SPOTTY CU FIELDS. && .AVIATION... AVIATION FORECASTS REMAIN CHALLENGING. CURRENT STRATUS TRENDS ARE NOT IN AGREEMENT WITH 12KM NAM BLYR RH FCSTS. PREVAILING MVFR WITH LOCALLY IFR CIGS ARE EXPANDING ACROSS THE NORTHEASTERN HALF OF FORECAST AREA WHILE TAF SITE KVTN NOW ON WRN EDGE OF MVFR CIGS. KLBF NO LONGER NEAR STRATUS AND ANY IFR CIGS AND HAVE UPDATED SITE FOR ONLY TEMPO 4SM BR TIL 14Z. 11-3.9 MICRO SATELLITE IMAGERY AND RUC40 300-310K THETA SFC SUPPORT NORTHEASTWARD MOVEMENT OF STRATUS LEAVING KLBF FREE OF STRATUS RETURN THIS AM. THUS HAVE UPDATED KLBF TO REMOVE CIGS. ALONG TWEB ROUTE 098...MVFR CIGS WILL PREVAIL FROM NEAR KVTN TO 20 SE OF KONL TIL 14Z...THEN LIFT AND SCATTER OUT AFTER 16Z. REMINDER OF TWEB ROUTE TO KOFK WILL SEE MVFR CIGS TIL 16Z DUE TO EASTWARD EXPANSION WHILE SEGMENT WEST TO KCDR WILL REMAIN UNDER VFR TODAY. TWEB ROUTES 264 AND 274 TO REMAIN UNDER VFR CONDITIONS. CONTINUED MONITORING OF SATELLITE IMAGERY AND TAF UPDATES FOR KVTN AND PORTIONS OF TWEB ROUTE 098 REMAIN LIKELY IF TREND CONTINUES. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MASEK/KAR ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 955 AM EDT SAT JUL 21 2007 .DISCUSSION... MAIN FRONTAL BAND STILL BACK ACROSS SRN GA BUT A PREFRONTAL TROF DRIFTING SOUTHWARD THROUGH C FL THIS MORNING. WESTERLY FLOW REGIME THROUGH LOWER/MID LEVELS WILL MEAN WEST COAST BOUNDARY SHOULD PENETRATE ACROSS THE PENINSULA. LOW LEVEL FLOW ON MORNING SOUNDINGS DOES NOT LOOK STRONG ENOUGH INHIBIT EAST COAST BOUNDARY ALTOGETHER BUT WILL ACT TO DELAY ONSET AND HOLD IT CLOSER TO THE EAST COAST. AMPLE MOISTURE COMBINING WITH THE LOW LEVEL BOUNDARIES AND ENHANCEMENT FROM DEEPENING MID/UPPER TROF THAT IS PROPELLING VORT ENERGY SOUTHWARD INTO THE PENINSULA...STORM COVERAGE WILL BE HIGH THIS AFTERNOON. MORNING SOUNDINGS IN C FL CAME IN COOLER THAN MODELS HAVE BEEN SUGGESTING WITH -9C/-10C AT CAPE AND TBW RESPECTIVELY. PLAN TO NUDGE SEVERE POTENTIAL UP IN LATE MORNING HWO/GHWO ISSUANCE WITH HAIL AND DAMAGING DOWNBURST WINDS AS PRIMARY THREAT. LATEST WATER VAPOR IMAGES AND RUC DATA INDICATING SOME NVA WORKING OVER THE AREA WHICH COULD HELP DELAY CONVECTION A LITTLE BUT SHOULD BECOME QUITE ACTIVE HEADING TOWARD THE LATE AFTERNOON AND INTO TONIGHT WITH INFLUENCE OF VORT ENERGY. DAYTIME STORM COVERAGE MAY BE A BIT HIGHER AND EARLIER OVER SOUTHERN SECTIONS WITH SURFACE BOUNDARY AND HOLD OFF A LITTLE LATER IN THE NORTH. WILL MAKE A FEW TWEAKS TO ZONES/GRIDS AND HWO AS TRENDS INDICATE. && .AVIATION...WILL MONITOR CU DEVELOPMENT AND STORM INITIATION TO REFINE TIMING FOR GREATEST CHANCE OF STORMS IN TAFS THIS AFTERNOON AND TONIGHT. DAMAGING WIND GUSTS AND HAIL POSSIBLE IN STRONGER STORMS. && .MARINE...OFFSHORE FLOW AOB 15 KT TODAY/TONIGHT EXPECTED TO BACK TO S/SSE ALONG THE COAST THIS AFTERNOON AS SEA BREEZE DEVELOPS. SEAS 1-2 FEET NEAR SHORE AND UP TO 3 FEET OFFSHORE. SCATTERED-NUMEROUS SHOWERS/STORMS WILL MOVE OFFSHORE...ESPECIALLY LATE AFTERNOON AND TONIGHT...SOME WITH GUSTS OVER 35 KT...HAIL AND FREQUENT LIGHTNING. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ GLITTO fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 1033 AM EDT SAT JUL 21 2007 .SYNOPSIS... A FRONTAL BOUNDARY WILL PUSH THROUGH THE AREA TODAY AND THEN LINGER OVER NORTHERN FLORIDA THROUGH SUNDAY. HIGH PRESSURE WILL BUILD OVER THE REGION IN THE WAKE OF THE FRONT AND PERSIST INTO EARLY NEXT WEEK. THE FRONTAL BOUNDARY OVER FLORIDA WILL THEN LIFT BACK NORTH AS A WARM FRONT BY MID WEEK. A WAVE OF LOW PRESSURE ALONG THE FRONT WILL KEEP HIGHER THAN NORMAL RAIN CHANCES OVER THE AREA THROUGH THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A CDFNT ALONG THE SAVANNAH RIVER WILL CONTINUE TO MAKE STEADY PROGRESS ACROSS SE GA THIS MRNG AND SHOULD CLR THE ALTAMAHA RIVER BY MID-LTE AFTN. NO SIGNIFICANT CAA IS NOTED BEHIND THE FNT BUT TEMPS ARE BEING TEMPERED DUE TO EXTENSIVE MID-HIGH LVL CLOUDINESS. MOSTLY CLOUDY SKIES SHOULD GIVE WAY TO SOME CLR DURING THE AFTN BASED ON THE LATEST RUC FCST SOUNDINGS. THE LATEST VSBL SATL DOES ALREADY SHOWS SOME BREAKS FROM ALLENDALE COUNTY E THROUGH CNTRL COLLETON COUNTY WHICH IS YIELDING SOME FILTERED SUNSHINE. STILL XPCT TEMPS TO RISE INTO THE UPR 80S TO AROUND 90 ACROSS INLAND AREAS BUT A MODERATE ONSHORE FLOW WL LIMIT TEMPS TO THE LWR 80S ALONG THE COAST. THE BEST CHANCES FOR TSTMS WL GENERALLY REMAIN W AND S OF THE I-16/95 CORRIDORS INTO ERLY EVNG. MODIFIED SOUNDINGS YIELD SBCAPES 2000-2500 J/KG WITH LI/S OF -5 BY ERLY AFTN IN THIS AREA. A WEAK RESULTANT SEA BREEZE ALONG THE N GA COAST MAY ALSO ADD ADDITIONAL LOW-LVL CONVG. PLAN TO MAINTAIN OUR CURRENT 20/30 POP REGIME THROUGH ERLY EVNG WITH THE HIGHEST GRIDDED POPS CONFINED TO SE GA. THERE WL BE ENOUGH LOW-LVL MOISTURE AND RESIDUAL INSTABILITY BEHIND THE FNT TO SUPPORT AT LEAST A SLGT CHANCE FOR A SHOWER OR TSTM ACROSS SE SC THUS SLGT CHANCE POPS WL BE MAINTAINED THERE. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... NOT MUCH CHANGE IN THE OVERALL PATTERN THROUGH TONIGHT. ALTHOUGH...WITH LOSS OF DAYTIME HEATING AND THE SEA BREEZE... WILL KEEP A DRY FORECAST OUTSIDE OF ANY LINGERING EVENING SHOWERS AND THUNDERSTORMS. LOWS WILL DIP INTO THE UPPER 60S INLAND WITH LOWER 70S NEAR THE COAST...ALTHOUGH CANNOT RULE OUT MID 60S IN SOME INLAND LOCALES. THE FRONTAL BOUNDARY WILL BE WELL SOUTH OF THE AREA ON SUNDAY. SURFACE DEWPOINTS STILL LOOK MARGINAL FOR WIDESPREAD CONVECTIVE DEVELOPMENT ALONG THE SEA BREEZE. HOWEVER WILL CONTINUE TO MENTION A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS...ESPECIALLY ACROSS SE GA WHERE LOW-LEVEL MOISTURE WILL BE A BIT HIGHER. HIGH TEMPERATURES SUNDAY WILL REACH THE LOWER 90S AWAY FROM THE COAST. AFTER LINGERING EVENING SHOWERS/THUNDERSTORMS...SUNDAY NIGHT WILL BE DRY WITH LOWS IN THE MID/UPPER 60S INLAND AND LOWER 70S NEAR THE COAST. INTERESTINGLY...THE RECORD LOWS FOR CHARLESTON /60 DEGREES SET IN 1966/ AND SAVANNAH /61 DEGREES SET IN 1966/ APPEAR TO BE SAFE...ALTHOUGH WE MAY GET WITHIN A FEW DEGREES OF THE RECORD LOW OF 69 DEGREES SET IN 1966 IN DOWNTOWN CHARLESTON. && .LONG TERM /MONDAY THROUGH FRIDAY/... A CLOSED UPPER LEVEL LOW PRESSURE SYSTEM WILL BE POSITIONED OVER THE OHIO VALLEY ON MONDAY...WHILE AT THE SURFACE A NORTHEAST FLOW ACROSS THE AREA WILL SLOWLY VEER ONSHORE AS HIGH PRESSURE BEGINS TO SHIFT OFFSHORE WELL NORTH OF THE AREA. ISOLATED CONVECTION IS EXPECTED ACROSS MOST AREAS MONDAY...ALTHOUGH THE COVERAGE SHOULD BE SCATTERED ACROSS PARTS OF SOUTHEAST GEORGIA WHERE GREATER MOISTURE POOLING AND SURFACE CONVERGENCE IS EXPECTED DUE TO THE PROXIMITY OF A STALLED FRONTAL BOUNDARY SOUTH OF THE AREA. A WARM FRONT WILL BEGIN TO LIFT ACROSS THE AREA ON TUESDAY IN RESPONSE TO THE HIGH PRESSURE SYSTEM THAT WILL CONTINUE TO MOVE FARTHER OFFSHORE NORTH OF THE AREA. ALONG THE EASTERN PERIPHERY OF THE UPPER LEVEL TROUGH A STRONG 250 MB JET WILL DEVELOP FOR THIS TIME OF YEAR...AND THE FORECAST AREA WILL BE LOCATED IN THE FAVORABLE FRONT ENTRANCE REGION. GIVEN THESE FACTORS ALONG WITH A DEEP ONSHORE FLOW...TUESDAY AFTERNOON/EVENING APPEAR FAVORABLE FOR AT LEAST SCATTERED SHOWER AND THUNDERSTORM ACTIVITY. THERE IS ALSO THE POTENTIAL FOR STRONG OR EVEN SEVERE THUNDERSTORMS TO DEVELOP AS DEWPOINTS RECOVER INTO THE LOWER 70S...CAPE VALUES APPROACH 1500 J/KG AND WIND SHEAR STRENGTHENS DUE TO THE PROXIMITY OF THE LIFTING FRONTAL BOUNDARY AND JETTING ALOFT. WEDNESDAY ALSO APPEARS FAVORABLE FOR SCATTERED SHOWERS AND THUNDERSTORMS AS THE FRONTAL BOUNDARY STALLS NEAR OF JUST WEST OF THE FORECAST AREA. MEANWHILE...WEAK CHANNELED VORTICITY ALOFT WILL BE IN PLACE ALONG THE EASTERN PERIPHERY OF THE UPPER LEVEL TROUGH AIDING IN LIFT ACROSS THE AREA. AS IF THE SYNOPTIC PATTERN MONDAY THROUGH WEDNESDAY WAS NOT UNUSUAL ENOUGH FOR THIS TIME OF YEAR...THE UPPER LEVEL LOW IS FORECAST TO MOVE SOUTH ACROSS THE SOUTHERN APPALACHIANS AND OVER THE DEEP SOUTH THURSDAY AND FRIDAY. A WAVE OF LOW PRESSURE COULD DEVELOP ALONG THE EASTERN PERIPHERY OF THE TROUGH AND TRACK NORTHEAST ALONG THE STALLED FRONTAL BOUNDARY DURING THIS TIME. AS A RESULT...SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED EACH AFTERNOON AND EVENING...AIDED BY THE SEA BREEZE BOUNDARY. TEMPERATURES SHOULD BE SLIGHTLY BELOW NORMAL TROUGH THE LONG TERM PERIOD. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... A COLD FRONT WILL CONTINUE TO TRACK SOUTHEAST ACROSS THE AREA THIS MORNING...THEN SHIFT SOUTH OF THE AREA LATER THIS AFTERNOON AS HIGH PRESSURE BUILDS DOWN FROM THE NORTH. LOW LEVEL MOISTURE POOLING SOUTH OF THE BOUNDARY HAS RESULTED IN SOME LOW STRATUS WHICH MAY RESULT IN IFR OR EVEN LIFR CEILINGS AT KSAV THROUGH 1300. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE ACCOMPANYING THE FRONT AND HAVE INCLUDED VICINITY SHOWERS IN THE KCHS TAF THROUGH 1400 UNTIL THE FRONT CLEARS THE TERMINAL. THE FRONT SHOULD MOVE ACROSS KSAV FROM AROUND 1400-1600. SHOWERS AND THUNDERSTORMS WILL STILL BE POSSIBLE LATER TODAY ALONG AND AHEAD OF THE SEA BREEZE WHICH SHOULD MOVE THROUGH THE TERMINALS LATE IN THE AFTERNOON. THE COVERAGE ON THE STORMS SHOULD BE ISOLATED IN THE KCHS VICINITY BUT SCATTERED IN THE KSAV VICINITY DUE TO THE PROXIMITY OF THE FRONTAL BOUNDARY...SO WILL KEEP MENTION OF CB THERE. EXTENDED AVIATION OUTLOOK...VFR CONDITIONS GENERALLY EXPECTED. HOWEVER...MVFR OR IFR CEILINGS ARE POSSIBLE IN ISOLATED OR SCATTERED AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS THROUGH WEDNESDAY. && .MARINE... A PINCHED GRADIENT HAS DVLPD OFF THE CHARLESTON COUNTY COAST IN THE WAKE OF THE CDFNT. SUSPECT WNDS ARE GENERALLY 15-20 KT IN THIS AREA BASED ON OBSERVATIONS FROM FBIS1. FARTHER S LGT WNDS ARE OCCURRING WITH SPEEDS GENERALLY 10-15 KT. THE FNT WL CONTINUE TO SAG S THROUGH THE GA WTRS THIS AFTN BACKING WNDS TO THE NE AS IT DOES. WNDS WL LIKELY BECOME MORE ELY ALONG THE GA COAST AS A WEAK RESULTANT DVLPS AND MOVES INLAND. WL UPDATE THE MARINE FCST SHORTLY TO SHOW HIGHER WNDS N OF EDISTO BEACH BUT KEEP CONDITIONS BELOW SMALL CRAFT SHOULD EXERCISE CAUTION THRESHOLDS. SEAS WILL BUILD TODAY...POSSIBLY REACHING SCSEC CRITERIA OVER THE OUTER GA WATERS AS EARLY AS EARLY SUN. AN EASTERLY SWELL WILL BE NOTICEABLE DUE TO THE PERSISTENT ONSHORE FLOW. ONSHORE WINDS ARE EXPECTED MONDAY AND TUESDAY ACROSS THE COASTAL WATERS AS HIGH PRESSURE SHIFTS OFFSHORE WELL NORTH OF THE REGION. A WARM FRONT WILL LIFT NORTH ACROSS THE AREA LATE TUESDAY...ALLOWING THE FLOW TO SHIFT MORE TO THE SOUTH/SOUTHWEST INTO THE MIDDLE OF THE WEEK. WIND SPEEDS SHOULD GENERALLY REMAIN AROUND 15 KT OR LESS WITH SEAS RANGING 2-4 FT MONDAY THROUGH WEDNESDAY. && .FIRE WEATHER... WE CONTINUE TO SUPPORT ONGOING WILDFIRE ACTIVITIES ON WASSAW ISLAND...FLORHAMMOCK ISLAND AND BULLS ISLAND. NO FIRE WEATHER PARAMETERS ARE XPCTD TO DROP BELOW CRITICAL THRESHOLDS ALTHOUGH GUSTY WNDS AT BULLS ISLAND WILL PERSIST FOR A FEW MORE HRS. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ ga AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 1040 AM CDT SAT JUL 21 2007 .DISCUSSION... ISSUED 1040 AM CDT SAT JUL 21 2007 HIGH PRESSURE CONTINUES TO SLOWLY SETTLE SOUTHWARD OVER LOWER MICHIGAN. AS A RESULT... LIGHT EASTERLY FLOW WILL PREVAIL TODAY. SLIGHTLY DRIER AIR ALOFT SHOULD RESULT IN LESS CU DEVELOPMENT THAN YESTERDAY... AND NAM/RUC RH FIELDS SUGGEST ANY CU WILL MAINLY BE ACROSS EASTERN IOWA... AND ALONG/EAST OF I57 EASTWARD TOWARDS INDIANA AND OHIO. WITH LESS CU AND CONTINUED DRY FLOW... SHOULD SEE TEMPERATURES CLIMB ANOTHER 2-3 DEGREES ON YESTERDAYS HIGHS. CURRENT FORECAST IS IN GOOD SHAPE. NO UPDATES. HARDIMAN && .AVIATION... ISSUED 623 AM CDT SAT JUL 21 2007...FOR THE 12Z TAFS THE RIDGE AXIS OF CANADIAN HIGH PRESSURE EXTENDS FROM EASTERN WISCONSIN THROUGH CENTRAL ILLINOIS TO ARKANSAS TODAY. LIGHT EAST WINDS ARE EXPECTED...WITH SCATTERED CUMULUS DEVELOPING AROUND MIDDAY NEAR 4K FT. NO CLOUD DECKS ARE EXPECTED...NOR ANY RESTRICTIONS TO VISIBILITY OVER THE NEXT 24 HOURS. SHIMON && .PREV DISCUSSION... ISSUED 330 AM CDT SAT JUL 21 2007 TRANQUIL CONDITIONS TO PREVAIL ACROSS CENTRAL AND SE ILLINOIS FOR THE NEXT SEVERAL DAYS AS HIGH PRESSURE REMAINS NEAR IL. NOT MUCH OF A FORECAST CHALLENGE WITH MODELS IN FAIRLY GOOD AGREEMENT INTO EARLY NEXT WEEK. EXTENDED MODELS TRENDING WITH BRINGING A WEAK UPPER LEVEL LOW WESTWARD TOWARD THE OHIO OR MID MS VALLEY DURING THE MIDDLE OF NEXT WEEK... WITH PATCHES OF QPF OVER IL WED AND/OR THU DEPENDING OF WHICH MODEL YOU FOLLOW. HPC PREFERRED THE GFS MODEL WHICH IS NOT AS FAR WEST WITH BRINGING WEAK UPPER LEVEL LOW AND KEEPS IL DRY THROUGH WED. SHORT TERM...TODAY THROUGH MONDAY NIGHT... 08Z/3 AM SURFACE MAP SHOWS 1024 MB CANADIAN HIGH PRESSURE OVER NE WI AND UPPER MI AND RIDGING SOUTHWARD ACROSS WESTERN IL. FRONTAL BOUNDARY EXTENDED FROM CENTRAL GA TO CENTRAL AR AND ARCHED BACK INTO CENTRAL KS AND WESTERN NEBRASKA. HIGH PRESSURE WAS PROVIDING FAIR SKIES ACROSS IL AND THE MIDWEST. TEMPS OVER CENTRAL/SE IL HAD COOLED INTO THE MID TO UPPER 50S WITH DEWPOINTS 50 TO 55F. LIGHT NE TO CALM WINDS. OMEGA BLOCK PATTERN AND UNSEASONABLY HIGHLY AMPLIFIED UPPER LEVEL PATTERN ALOFT. STRONG UPPER LEVEL RIDGE OVER THE HIGH PLAINS AND STRONG UPPER LEVEL TROFS OVER THE PACIFIC NW AND EASTERN PART OF CANADA AND U.S. CANADIAN HIGH PRESSURE TO DRIFT SLOWLY EAST INTO LOW MI BY SUNSET WHILE WEAK UPPER LEVEL SHORT WAVE DIVES SOUTH INTO INDIANA. JUST FEW TO SCATTERED CUMULUS CLOUDS OVER MAINLY EASTERN IL BY AFTERNOON...SO A SUNNY TO MOSTLY SUNNY AND NICE DAY. MAV WAS TOO WARM YESTERDAY AND APPEARS TO BE AGAIN TODAY THOUGH HIGH TEMP GUIDANCE CLOSER TODAY. FOLLOWED BLEND OF FWC AND MET HIGHS IN THE UPPER 70S TO AROUND 80F. FAIR SKIES TONIGHT WITH LOWS IN THE LOW TO MID 50S AS CANADIAN HIGH PRESSURE STAYS OVER THE GREAT LAKES. HIGH PRESSURE OVER NEW ENGLAND SUN/MON AND RIDGING BACK INTO IL AND TO KEEP MOSTLY SUNNY SKIES AND HIGHS IN THE LOWER 80S SUN AND MID 80S MON AS AIR MASS SLOWLY MODIFIES. SLOWED WARMING A BIT INTO EARLY NEXT WEEK AS 850 MB TEMPS DO NOT RISE TOO MUCH WITH BLOCKED UPPER LEVEL PATTERN. LONG TERM...TUESDAY THROUGH FRIDAY... WEAK CUTOFF UPPER LEVEL LOW THAT DEVELOPS OVER THE MID ATLANTIC STATES MON APPEARS TO RETROGRADE WESTWARD INTO THE OHIO VALLEY DURING NEXT WORK WEEK PER GFS. TEMPS CONTINUE TO SLOWLY MODIFY WITH HIGHS IN THE UPPER 80S TO NEAR 90F AS DEWPOINTS ELEVATE THROUGH THE 60S...SO TO MORE SEASONABLE LEVELS FOR LATE JULY. QUESTION MARK ON IF CONVECTION CHANCES POSSIBLE BY WED OR THU. HPC FOLLOWED FURTHER EAST GFS MODEL WITH UPPER LEVEL FLOW WHICH WOULD KEEP IL DRY INTO THE MIDDLE OF NEXT WEEK. ECMWF IS MOST AGRESSIVE WITH STRONGER CUTOFF LOW GETTING WEST INTO IL BY 12Z/WED WHILE CANADIAN AND NAM EXTRAPOLATED HAS WEAKER UPPER LEVEL LOW IN SOUTHERN IL THEN. IF THIS SCENERIO PANS OUT...WILL HAVE BETTER CHANCE OF AFTERNOON/EVENING CONVECTION WED AND THU WITH MORE CLOUDS AND A BIT COOLER HIGHS. HUETTL && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ il AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 745 AM EDT SAT JUL 21 2007 UPDATED AVIATION DISCUSSION FOR 12Z TAFS .DISCUSSION (457 AM EDT)... THE MAIN FORECAST CONCERN DEALS WITH PCPN CHCS SUN NIGHT INTO TUE. WATER VAPOR LOOP...RUC ANALYSIS AND 00Z RAOB PLOTS SHOW AN AMPLIFIED UPR RIDGE BUILDING FROM THE PLAINS INTO THE WESTERN GREAT LAKES. AT THE SFC HIGH PRES IS CENTERED OVER ERN UPR MI MAINTAINING CLEAR SKIES ACROSS THE REGION EARLY THIS MORNING. SUNNY SKIES AND MIXING OF 850 MB TEMPS 12-14C WILL ALLOW INLAND HIGHS TO REACH THE UPR 70S AND LOWER 80S TODAY. WEAK PRES GRADIENT WITH THE PROXIMITY OF THE SFC HIGH WILL ALLOW FOR LAKE BREEZE CIRCULATIONS TO KEEP TEMPS SLIGHTLY COOLER NEAR THE GREAT LAKES SHORELINES. AS THE SFC HIGH SLIDES INTO THE LOWER GREAT LAKES...A BIT STRONGER SW FLOW WILL DEVELOP BEHIND IT OVER UPR MI TONIGHT. EXPECT THE LOWEST TEMPS (AROUND 50F) OVER THE INTERIOR SCNTRL AND E COUNTIES CLOSER TO WEAKER PRES GRADIENT AND LOWER PWAT AIR ASSOCIATED WITH HI PRES CENTER. LOOK FOR A MOSUNNY AND WARMER DAY ON SUN WITH ANTICYCLONIC SW FLOW AROUND HI PRES OVER LAKE HURON. H85 TEMPS FCST TO RISE TO 14C-16C...AND MIXING AOA 800 MB ON GFS FCST SDNGS SUPPORTS HI TEMPS PUSHING APPROACHING 85F OVER MUCH OF W AND CENTRAL UPR MI. MODERATION DOWNSTREAM OF LAKE MI WILL KEEP TEMPS A FEW DEGREES COOLER THERE. MODELS STILL PERSIST ON BRINGING STRONG 850 MB THETA-E ADVECTION AND HIGHER PWATS (> 1.5 INCHES) INTO WRN COUNTIES SUN NIGHT INTO MON AHEAD OF SHRTWV LOBE RIDING OVER TOP OF PLAINS RDG. KEPT GOING SLIGHT CHC POPS FOR THE WRN COUNTIES SUN NIGHT AND THEN SPREAD SLIGHT CHC POPS INTO CENTRAL AND ERN COUNTIES ON MON AS HIGHER PWAT/THETA-E AIR ADVANCE E. 00Z GFS/NAM AND CANADIAN MODELS ALL SEEM TO SUGGEST HIGHER PWAT/THETA-E AIR AND SFC BOUNDARY WILL LINGER INTO TUE WITH CUT-OFF LOW DRIFTING WWD INTO THE OH VALLEY/LWR GRT LKS. THUS...HAVE EXTENDED THE SLIGHT CHC POP FOR MON NIGHT INTO TUE EVENING ACROSS THE ENTIRE CWFA. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... SCATTERED...EVEN BROKEN...MID CLOUDS ARE PRESSING SSE OUT OF ONTARIO OUT OVR NORTHERN LK SUPERIOR. SATELLITE INDICATES THAT PORTION OF THE CLOUDS WILL SKIRT TAF SITES THROUGH MID AFTN. HOWEVER... SUSTANTIAL DRY AND STABLE LAYER SFC-10KFT WILL KEEP BASES WELL ABOVE THE VFR/MVFR THRESHOLD OF 3KFT. HIGH PRESSURE IN THE REGION WILL ONCE AGAIN PRODUCE LAKE BREEZES THIS AFTN. AS HIGH IS TO THE SOUTHEAST OF THE AREA THIS AFTN EXPECT THE STRONGEST WINDS WILL BE AT KSAW DUE TO THE BREEZE SPREADING IN OFF NORTHERN LK MI. && .MARINE (FOR 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... HIGH PRESSURE OVER THE UPPER GREAT LAKES WILL BUILD ACROSS THE REST OF THE GREAT LAKES TODAY. LOW PRESSURE TROUGH MOVING ACROSS NORTHERN ONTARIO LATE SUN INTO SUN NIGHT MAY TEMPORARILY INCREASE PRESSURE GRADIENT ENOUGH TO ALLOW FOR S WINDS TO INCREASE ABOVE 20 KT ON EASTERN SECTIONS OF LK SUPERIOR. RELAXING GRADIENT ON MON WILL RESULT IN SOUTH TO SOUTHWEST WINDS LESS THAN 20 KT THROUGH THE MIDDLE OF NEXT WEEK. && $$ PUBLIC...VOSS AVIATION/MARINE ...JLA mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HASTINGS NE 641 AM CDT SAT JUL 21 2007 .AVIATION...CONCERN THIS CYCLE IS HOW LONG IFR CONDITIONS WILL LAST. FOG CHANNEL ON SATELLITE SHOWS STRATUS AREA HAS CONTINUED TO INCREASE IN SIZE PAST COUPLE OF HOURS. NOW STRETCHES ACROSS EAST CENTRAL NEB FROM SDAK TO KS BORDERS. MOISTURE CONFINED TO THE LOWER LEVELS AND THINK CIGS AND VSBYS SHOULD GRADUALLY IMPROVE THROUGH MID MORNING. WINDS HAVE STAYED UP SO DO NOT EXPECT VSBY TO DROP BELOW 4 OR 5 MILES. && .PREV DISCUSSION... /ISSUED 402 AM CDT SAT JUL 21 2007/ DISCUSSION...PAST EVENING UPPER AIR DATA ALONG WITH EARLY MORNING WATER VAPOR IMAGERY CONTINUES TO SHOW A LARGE RIDGE SITTING ACROSS THE CENTRAL CONUS. SEVERAL SMALL BUT POTENT WAVES CAN BE SEEN ROTATING AROUND THE PERIPHERY OF THIS RIDGE. LATEST SURFACE ANALYSIS SHOWS A STATIONARY FRONT STRETCHING FROM SOUTHEAST KANSAS INTO WESTERN NEBRASKA. RUC ANALYSIS DATA SHOWS MODEST 850MB THETA-E ADVECTION EAST OF THE SURFACE FRONT WHICH CONTINUES TO TRIGGER SOME WEAK ISOLATED CONVECTION ACROSS EASTERN KS INTO WESTERN IA. A HOT AND GENERALLY DRY PATTERN WILL TAKE HOLD OF THE REGION TODAY INTO TONIGHT AS THE UPPER RIDGE REMAINS IN CONTROL OF THE AREA. THIS WILL ALLOW THE AFOREMENTIONED STATIONARY FRONT TO CONTINUE LIFTING SLOWLY NORTHEAST ACROSS THE REGION TODAY. ALTHOUGH LOW LEVEL FORCING ALONG THIS BOUNDARY WILL BE WEAK AT BEST...CAPE VALUES OF 1500-2000 J/KG ALONG WITH WEAK CAPPING COULD TRIGGER A FEW SHOWERS EAST OF A HEBRON TO BELOIT LINE THIS AFTERNOON TO EARLY EVENING. OTHERWISE...LOOK FOR STRATUS ACROSS PORTIONS OF THE REGION THIS MORNING TO SLOWLY GIVE WAY TO A MOSTLY CLEAR TO PARTLY CLOUDY SKY AS TEMPERATURES CLIMB INTO THE UPPER 80S TO MID 90S. SUNDAY IS THEN SHAPING UP TO BE ANOTHER HOT AND GENERALLY DRY DAY ACROSS THE AREA ALTHOUGH THE UPPER RIDGE IS SHOWN TO BEGIN RETROGRADING BACK INTO THE ROCKIES AND INTERMOUNTAIN WEST DURING THIS TIME FRAME. ALTHOUGH BETTER LOW LEVEL FORCING ON SUNDAY WILL REMAIN ACROSS THE HIGH PLAINS CLOSER TO THE LEE TROUGH...A SMALL BUT POTENT WAVE SLIDING SOUTH ALONG THE FRONT SIDE OF THE UPPER RIDGE MAY TRIGGER SOME ISOLATED CONVECTION. BEST CHANCE FOR THIS CONVECTION LOOKS TO BE EAST OF A YORK TO BELOIT LINE. WILL AIM FOR AFTERNOON HIGHS IN THE LOWER TO MID 90S. AS THE REGION HEADS INTO MONDAY THE UPPER RIDGE BEGINS TO BUILD BACK INTO THE NORTHERN PLAINS WHILE A POSITIVELY TITLED UPPER TROUGH OVER THE EASTERN CONUS BEGINS TO BACK INTO THE LOWER TO MID MS RIVER VALLEY. THIS WILL KEEP THE FORECAST AREA ON THE UNSETTLED EASTERN EDGE OF THE UPPER RIDGE. AS WAS THE CASE ON SUNDAY...IT APPEARS ANOTHER WAVE RIDING ALONG THE FRONT SIDE OF THE RIDGE COULD TRIGGER SOME ISOLATED CONVECTION EAST OF A YORK TO BELOIT LINE. AFTERNOON TEMPERATURES WILL ALSO BE SIMILAR WITH HIGHS VARYING FROM THE LOWER TO MID 90S. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 930 AM EDT SAT JUL 21 2007 .SYNOPSIS... A WEAK AND DIFFUSE COLD FRONT MOVING OFF THE CAROLINA COAST WILL BE FOLLOWED BY A RELATIVELY COOLER AND DRIER MODIFIED CANADIAN HIGH PRESSURE AIR MASS. AN UPPER LEVEL TROUGH WILL AMPLIFY ACROSS THE EASTERN ONE THIRD OF THE U.S. TODAY THROUGH THIS WEEKEND. BERMUDA HIGH PRESSURE WILL BECOME REESTABLISHED ACROSS THE AREA THROUGH MID TO LATE NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MADE A FEW SUBTLE CHANGES TO CLOUD COVER TRENDS OTHERWISE CURRENT FORECAST LOOKS GOOD. LATEST RUC CONTINUES TO SHOW A LITTLE ACTIVITY ACROSS EXTREME SOUTHERN SECTIONS OF AREA THIS AFTERNOON WITH FRONTAL BOUNDARY. CURRENT SLIGHT CHANCE POPS SHOULD SUFFICE. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/... CUT OFF LOW DEVELOPS TONIGHT WITHIN DEEP H5 TROUGH EXTENDING SOUTH ACROSS EASTERN CONUS. MOST GUIDANCE HAS LOW CENTER MEANDERING OVER THE MOUNTAINS OF VIRGINIA THROUGH MONDAY MORNING...THEN LIFTING NORTH OVER WESTERN PA MONDAY NIGHT. NAM IS A BIT OF AN OUTLIER HERE...KEEPING LOW CENTER SIGNIFICANTLY FURTHER TO THE SW. SO...HAVE LEANED ON THE GFS FOR THIS PERIOD. AT THE SURFACE HIGH PRESSURE NOSES IN BRINGING A RELATIVELY COOL NORTH TO NORTHEASTERLY FLOW TO THE REGION INTO SUNDAY NIGHT. ALTHOUGH COLD AIR ADVECTION WILL BE WEAK...AT LEAST THIS TIME THERE WILL BE SOME COLD AIR ADVECTION. SO WILL BE KEEPING TEMPS BELOW CLIMO. TONIGHT AND SUNDAY NIGHT MAY SEE MIN TEMPS DROP 10 DEGREES BELOW SEASONAL NORMS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... CHANGES IN THE GFS COMPARED TO YESTERDAY/S RUN IN THE HANDLING OF THE UPPER LOW ACROSS THE EASTERN UNITED STATES. THE LATEST RUN INDICATES THE UPPER LOW PERSISTING MUCH FARTHER INTO THE EXTENDED PERIOD AND SUBSEQUENTLY THE TREND IN GUIDANCE HAS BEEN FOR COOLER MAX READINGS DURING THE SECOND HALF OF THE WEEK. UNTIL THERE IS BETTER CONTINUITY PLAN TO SPLIT THE DIFFERENCE BETWEEN THE OLD FORECAST TEMPERATURES AND THE COOLER GUIDANCE. HARD TO PIN DOWN ANY SPECIFIC TIME FOR POPS WITH ANY CONFIDENCE...HOWEVER WOULD EXPECT A POSSIBILITY FOR MAINLY DIURNALLY DRIVEN CONVECTION ESPECIALLY WITH COOLER TEMPERATURES ASSOCIATED WITH THE UPPER LOW. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... LINGERING SHOWER ACTIVITY HAS ALL BUT MOVED OFF THE COAST THIS MORNING LEAVING VFR CONDITIONS BEHIND. DID HAVE TO USE A TEMPO GROUP TO ADDRESS MVFR IN FLO BUT ONLY FOR TWO HOURS. FORECAST DIFFICULTY FOR TODAY WILL BE TIMING OF CLEARING. BASICALLY FOLLOWED THE GFS 700MB RH FIELDS FOR A WEST TO EAST TEMPORAL TREND. EXPECT VFR CONDITIONS WITH HIGH PRESSURE BUILDING IN THROUGH EARLY PART OF WEEK. BY MID WEEK WILL SEE INCREASING CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS AS HIGH PRESSURE MOVES OFF SHORE AND RETURN FLOW OF MOISTER AND MORE UNSTABLE AIR MOVES IN. && .MARINE... NEAR TERM /UNTIL 6PM THIS EVENING/... INCREASED WINDS ACROSS NORTHERN ZONES TO AROUND 15 KNOTS AMZ250 AND A RANGE OF 15-20 KNOTS ACROSS AMZ252 AS BUOY OBSERVATIONS AND GFS ARE SHOWING A SURGE ACROSS THESE AREAS ASSOCIATED WITH 1011MB LOW ACROSS THE GULF STREAM. NO OTHER CHANGES. SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... CAA ASSOCIATED WITH COLD FROPA WILL BE WEAK SO DO NOT EXPECT MUCH OF A COLD SURGE AT THE BEGINNING OF THE SHORT TERM. SEAS MAY START OUT AS HIGH AS 4 FT AT THE OUTER FRINGES OF OUR WATERS TONIGHT BUT THIS WILL NOT LAST AS HIGH PRESSURE NOSES IN AND GRADIENT SLACKENS. OVERALL EXPECT SEAS IN THE 2 OR 3 FT RANGE THROUGH THE SHORT TERM. LONG TERM /MONDAY THROUGH WEDNESDAY/... THE FLOW WILL GRADUALLY VEER FROM AN E-SE DIRECTION MONDAY TO A SOUTHERLY DIRECTION TUESDAY AS HIGH PRESSURE MOVES OFF THE COAST. SOUTHERLY FLOW WILL PREVAIL THROUGH THE REMAINDER OF THE LONG TERM PERIOD WITH SPEEDS LESS THAN 15 KTS. NOT MUCH CHANGE IN SEAS THROUGH THE PERIOD WITH AN AVERAGE OF 3 FT...WHICH LOOKS REASONABLE COMPARED TO WNA AND REEFCAST. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...RGZ NEAR TERM...15 SHORT TERM...REK AVIATION...15 nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 1101 AM EDT SAT JUL 21 2007 .SYNOPSIS... COOL AND LESS HUMID AIR WILL REMAIN OVER THE REGION THROUGH THE MONDAY. AN UPPER LEVEL TROUGH WILL DEEPEN OVER THE EASTERN PART OF THE COUNTRY EARLY NEXT WEEK... KEEPING CONDITIONS UNSETTLED. MOIST SOUTHERLY FLOW WILL ALLOW TEMPERATURES AND HUMIDITY TO SLOWLY CLIMB TOWARD NORMAL SUMMERTIME LEVELS BY FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... TWO MAIN CONCERNS FOR THE AFTERNOON ARE HIGHS AND POSSIBILITY OF ISOLATED MOUNTAIN CONVECTION. 12Z OBSERVED THICKNESS FROM THE GSO RAOBS WARMER THAN EXPECTED. FULL SUN TEMP THERE IS 87 WITH 93 FOR FFC. DO NOT EXPECT FULL SUN TODAY AS THERE IS PLENTY OF MOISTURE AROUND H8 WITH EASTERLY FLOW AND SUBSIDENCE INVERSION BASE AROUND H7. IN FACT...CLOUDS ALREADY DEVELOPING ACROSS MUCH OF WESTERN NC...THE UPSTATE AND NE GA. SINCE COOLER AIR MASS IS BUILDING IN AND LESS THAN FULL SUN EXPECTED...WILL UNDERCUT THE THICKNESS HIGHS WHICH RAISES FORECAST HIGHS A DEGREE OR TWO OVER NC WITH LITTLE CHANGE SOUTH. FIRST LOOK AT 12Z NAM SHOWS IT HAS BACKED OFF ON INSTABILITY AND PW FORECAST FOR THE AFTERNOON. IT ALSO HAS MUCH LESS CONVECTION IN ITS PRECIP FORECAST. 09Z SREF AND 06Z GFS ARE DRY WITH ONLY THE 12Z RUC KEEPING HIGHER INSTABILITY AND MORE CONVECTION FOR THE MOUNTAINS. EVEN THOUGH SHORT WAVE WILL MOVE INTO THE AREA AND COOLING MID LEVELS...DEW POINTS ARE LOW ENOUGH AND LOW LEVEL SUBSIDENCE INVERSION WILL BE ENOUGH TO PRECLUDE ONLY THE SMALLEST INSTABILITY. THEREFORE...WILL KEEP GOING POP FREE FORECAST. UPPER TROF CONTINUES TO DIG OVER THE REGION TONIGHT WHILE SURFACE HIGH BUILDS FARTHER S OVER AREA. LOWEST LEVELS REMAIN FAIRLY DRY BUT H85 TO H7 MOISTURE WILL INCREASE IN E UPSLOPE FLOW AND UVV...SO HAVE INCREASED CLOUDS OVERNIGHT...ESP ALONG THE ESCARPMENT. MORNING LOWS WILL RANGE FROM THE MID 60S ACROSS FAR S CWA TO UPPER 50S N NC FOOTHILLS/PIEDMONT...WITH UPPER 40S TO LOW 50S MTNS. && .SHORT TERM /SUNDAY THROUGH MONDAY/... A BELOW NORMAL MAX TEMP FCST WILL BE MAINTAINED FOR SUNDAY WITHIN THE LLVL EASTERLY FLOW. THE LATEST OP GFS/SREF PROGGING VERY SIMILAR POSITIONING WITH RESPECT TO UPPER LOW AND WILL TAKE A BLEND OF THE RESPONSE OF THESE TWO SOLUTIONS FOR POPS. WILL PLAN ON CENTERING CHANCE THUNDER OVER THE SW ESCARPMENT SUNDAY AFTERNOON...WHICH IS IN GOOD AGREEMENT WITH THE NEW DAY 2 HPC QPF FCST. FLOW REGIME JUST ATOP LIGHT SFC LAYER IS PROGGED TO VEER TO A MORE SOUTHERLY COMPONENT SUNDAY NIGHT. WEAK UPSLOPE/UPGLIDE FLOW COULD MAINTAIN A FEW SHOWERS INTO THE OVERNIGHT HOURS OVER THIS SAME AREA. SFC RIDGING OVER THE REGION ON MONDAY LOOKS TO BE WEAKENING RESULTING IN A SLIGHT INCREASE IN LLVL RETURN FLOW. THERE WILL CERTAINLY WILL BE LINGERING EFFECTS OF RETROGRADING UPPER LOW...BUT IT IS DEBATABLE WHETHER MID-LVL TEMPS WILL BE AS COOL AS SUNDAY. AT ANY RATE...INHERITED POP ORIENTATION SEEMS PRETTY GOOD...THUNDER CHANCES MAINLY OVER THE WESTERN CWFA. WILL ALSO PLAN ON ROUGHLY PERSISTENCE MAXES...RESULTING IN CONTINUED BELOW NORMAL READINGS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... FOR THE TIME BEING ANYWAY...THERE IS PRETTY GOOD AGREEMENT BETWEEN THE LATEST MEX GUIDANCE AND OUR GOING BELOW NORMAL MAX TEMP FCST FOR TUESDAY...AS THE SOUTHERLY FLOW DEEPENS AND INCREASES ACRS THE SOUTHEAST U.S. SOLID CHANCE POPS WILL BE LEFT FOR NOW...BUT WE MAY NEED AN UPWARD ADJUSTMENT LATER THIS MORNING. THE SAME CAN SAID FOR WEDNESDAY...ANOTHER BELOW NORMAL MAX TEMP FCST WITH LINGERING SOUTHERLY FLOW AS UPPER TROUGH AXIS IS STILL OFF TO OUR WEST. WILL LEAVE THE GOING TREND OF DRIFTING BACK TOWARD MORE TYPICAL LATE JULY WARMTH AND HUMIDITY AS IS WITH DAILY TSTM CHANCES AS IS. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... LOW LEVEL DRYING WILL CONTINUE OVERNIGHT WITH SCT LOW TO MID CLOUDS AND OCNL BKN CIRRUS. WINDS WILL CONITNUE FROM THE N-NE AND MIXING SHOULD PRECLUDE ANY RESTRICTIONS TO VISIBILITY. AVIATION OUTLOOK...INCREASINGLY MOIST EASTERLY FLOW WILL LEAD TO MORE CLOUDS AND POSSIBLE LATE DAY CONVECTION SUNDAY THROUGH MID WEEK. ALSO EXPECT AN INCREASING CHANCE OF MORNING FOG. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...RB NEAR TERM...RB/RWH SHORT TERM...CSH LONG TERM...ARK/CSH AVIATION...RB sc AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE ABERDEEN SD 1053 AM CDT SAT JUL 21 2007 .UPDATE... UPDATED THE FORECAST THIS MORNING BASED OFF LATEST RUC AND NAM SOLUTIONS TO INCREASE MAX T VALUES ACROSS THE WESTERN THIRD OF ZONES GIVEN 850HPA THERMAL PROGS TO +29C TO +31C NOTED OUT THERE...WITH 925HPA THERMAL PROGS OF +34C TO +37C ACROSS THE FAR WESTERN ZONES DURING PEAK HEATING TODAY. ALSO ADJUSTED DEWPOINT GRIDS BASED OFF CURRENT CONDITIONS AND 12Z NAM SURFACE DEWPOINTS. THIS RESULTS IN HEAT INDICES OF 103 TO 106 THIS AFTERNOON ACROSS THE WESTERN THIRD OF ZONES...BUT NOT QUITE LONG ENOUGH TO SATISFY LENGTH OF TIME REQUIREMENT FOR A HEAT ADVISORY. SO...WILL REFRAIN FROM ISSUING ONE AT THIS TIME. RELATIVE HUMIDITIES ARE ALSO NOW FORECASTED TO DIP DOWN TO AROUND 25 TO 30 PERCENT ACROSS JONES/STANLEY COUNTIES THIS AFTERNOON ON 15 TO 25 MPH SOUTHERLY WINDS WITH HIGHER GUSTS. UPDATED THIS MORNING TO INCREASE WIND SPEED FORECAST TO BREEZY CATEGORY ACROSS ENTIRE FORECAST AREA. PROLLY WILL UPDATE RANGELAND FIRE DANGER PRODUCT TO BUMP JONES/STANLEY COUNTIES TO EXTREME FIRE DANGER FOR THIS AFTERNOON. && .PREV DISCUSSION... .SHORT TERM...TODAY THROUGH MONDAY NIGHT THE PRIMARY CHALLENGES IN THE SHORT TERM ARE PRECIPITATION AND THUNDERSTORM CHANCES AND TEMPERATURES. MODELS HAVE BEGUN HOLDING BACK ON PUSHING THE CENTER OF THE UPPER LEVEL HIGH INTO THE NORTHERN PLAINS...KEEPING IT SOMEWHAT TO THE WEST AND SOUTH THE NEXT FEW DAYS. THUS...THE GFS/NAM/CANADIAN ARE IN GENERAL AGREEMENT IN BRINGING A SERIES OF WAVES AROUND THE TOP OF THE RIDGE INTO NORTH DAKOTA AND MINNESOTA EACH OF THE NEXT THREE NIGHTS...THOUGH PLACEMENT AND STRENGTH DIFFERS BETWEEN EACH MODEL. TONIGHT...A SHORTWAVE MOVES NORTH TO HUDSON BAY...WITH A SURFACE TROUGH EXTENDING SOUTHWARD THROUGH THE DAKOTAS. THE 00Z GFS GENERATES SOME CONVECTION WITH THIS TROUGH IN NORTH DAKOTA AND MINNESOTA AS IR DEVELOPS A SECONDARY SHORTWAVE NEAR THE INTERNATIONAL BORDER...WITH AIR ALOFT IS NOT AS WARM THERE AS IN SOUTH DAKOTA. THE 00Z/06Z NAM RUNS...ON THE OTHER HAND...MOVE ENERGY FROM NORTHWEST WYOMING THIS MORNING AND OVER THE TOP OF THE RIDGE JUST INTO CANADA AND THEN DIVES IT SOUTHEAST STRAIGHT THROUGH EASTERN SOUTH DAKOTA...GENERATING THUNDERSTORMS IN NORTH DAKOTA BEFORE MOVING THEM SOUTHEASTWARD THROUGH MOST OF OUR CWA TONIGHT. WITH NOT MUCH SEEN ON SATELLITE IMAGES IN NORTHWEST WYOMING...HAVE KEPT THE AREA DRY FOR NOW...BUT THAT MAY HAVE TO BE LOOKED AT LATER TODAY IN FUTURE MODEL RUNS. OTHERWISE...THERE IS GENERAL AGREEMENT BETWEEN THE GFS/ECMWF/UKMET IN HANGING THE SURFACE TROUGH/FRONT UP IN NORTH DAKOTA AND NORTHERN MINNESOTA AND MOVING A COUPLE WAVES AROUND THE PERIPHERY OF THE RIDGE SUNDAY AND MONDAY NIGHTS...POTENTIALLY AFFECTING MOSTLY OUR FAR EASTERN CWA. FOR NOW...LEFT POPS JUST UNDER SLIGHT CHANCE CATEGORY...BUT THIS MAY ALSO NEED TO BE REVISITED. THE STORM PREDICTION CENTER HAS PLACED SOME OR ALL OF THE AREA IN SEE TEXT REGIONS WITH FIVE PERCENT PROBABILITIES OF SEVERE WEATHER FOR DAYS ONE THROUGH THREE. AS FOR CLOUD COVER...SOME BLOW OFF CLOUDS FROM EARLIER CONVECTION IN EASTERN WYOMING HAVE MOVED INTO THE WESTERN CWA...AND EXPECT THESE TO GRADUALLY DISSIPATE AS THEY MOVE EASTWARD TODAY. HOWEVER...MOISTURE RETURN FROM THE SOUTH TODAY LOOKS TO INCREASE CLOUD COVER OVER A GOOD PART OF THE SOUTHERN AND EASTERN CWA TODAY...AND HIGH CLOUDS FROM ANY THUNDERSTORMS IN NORTH DAKOTA TONIGHT MAY MOVE INTO THE AREA AS WELL. FINALLY...REGARDING TEMPERATURES AND DEW POINTS...AFOREMENTIONED CLOUD COVER APPEARS TO HOLD HIGH TEMPERATURES TODAY DOWN A BIT FROM PREVIOUSLY INDICATED...ESPECIALLY IN THE EAST. ALSO...850HPA TEMPERATURES ARE NOT SEEN AS HIGH AS PREVIOUSLY INDICATED...RISING TO NEAR 20 EAST TO THE UPPER 20S WEST THIS AFTERNOON. THUS...LOWERED HIGHS THIS AFTERNOON A NOTCH. MODELS STILL AGREE ON STRONG MOISTURE RETURN TODAY ACROSS THE AREA WITH DEW POINTS CLIMBING TO THE UPPER 60S TO NEAR 70 ACROSS MOST AREAS BY LATE THIS AFTERNOON. THESE MORE HUMID CONDITIONS WILL SURELY KEEP LOW TEMPERATURES TONIGHT FROM FALLING MUCH BELOW 70. ON SUNDAY AND MONDAY...THE RIDGE CENTERED TO THE WEST KEEPS 850HPA TEMPERATURES GENERALLY IN THE MIDDLE TO UPPER 20S BOTH DAYS ACROSS THE CWA. THIS COMBINED WITH DEW POINTS NEAR 70 TO POTENTIALLY A BIT HIGHER AND SOUTHERLY WINDS...SUGGEST THAT MOST OF THE AREA MAY STRUGGLE TO SEE PREVIOUSLY INDICATED HIGHS. THE NAM BRINGS THE FRONTAL BOUNDARY TONIGHT SOUTHWARD THROUGH THE NORTHERN CWA BY SUNDAY...KEEPING TEMPERATURES A BIT COOLER THAN OTHER MODELS...BUT THAT IS LIKELY A REFLECTION OF THE SHORTWAVE IT MOVES SOUTHEASTWARD THROUGH THE AREA TONIGHT...AND WITH DIFFERENCES FROM OTHER MODELS...HAVE GENERALLY DISREGARDED IT THIS MORNING...THOUGH THE 06Z RUN HAS JUST ARRIVED WITH THE SAME GENERAL IDEA AS THE 00Z RUN. REGARDLESS...LOWERED HIGH TEMPERATURES BOTH SUNDAY AND MONDAY ABOUT FIVE DEGREES MOSTLY ACROSS THE EASTERN CWA DUE TO THE HUMID CONDITIONS. IT IS INTERESTING TO NOTE THAT THOUGH MEX GUIDANCE HAS 100 FOR KABR ON SUNDAY...AND ENSEMBLE GUIDANCE RANGES FROM 93 TO 100...THE ENSEMBLE MEAN IS 94...SUGGESTING THAT MOST MEMBERS ARE KEEPING IT LOWER. THE NEW FORECAST TEMPERATURES KEEP HEAT INDICES BELOW HEAT ADVISORY CRITERIA FOR THE ENTIRE CWA THROUGH MONDAY. .LONG TERM...TUESDAY THROUGH THURSDAY MORNING MEDIUM RANGE MODELS CONTINUE TO SHOW A LARGE HIGH PRESSURE AREA ALOFT OVER THIS AREA. THIS FEATURE WILL STEER ANY WEATHER AROUND THE AREA SO CONTINUED THE DRY FORECAST. TEMPERATURES WILL BE VERY WARM WITH GOOD SUNSHINE. DEW POINTS WILL BE HIGH ENOUGH TO ALSO HOLD TEMPERATURES UP AT NIGHT. FEW SUBSTANTIVE CHANGES MADE TO THE GOING PACKAGE DURING THIS TIME FRAME. && .AVIATION... THE SOUTHEASTERLY FLOW AND RESULTING MOISTURE ADVECTION IS RESULTING IN SOME LINGERING AREAS OF MVFR CONDITIONS IN THE EASTERN CWA...WITH SOME CEILINGS RANGING FROM 016 TO 025. THESE AREAS OF LOW CEILINGS ARE EXPECTED TO SCATTER OUT BY LATE MORNING...CREATING VFR CONDITIONS...WHICH ARE EXPECTED TO REMAIN THROUGHOUT THE REST OF THE DAY. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...DORN SHORT TERM...ECKSTEIN LONG TERM...KEARNS AVIATION...GIONTA sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 315 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 18Z TAF ISSUANCE)... HIGH PRESSURE OVER THE AREA WITH PLENTY OF DRY AIR WILL KEEP SKIES CLEAR INTO SUN MORNING. KCMX SHOULD SEE A LAKE BREEZE FROM THE E SET UP THIS AFTERNOON...THEN A QUICK RETURN TO A SW DIRECTION TONIGHT AS THE HIGH SLOWLY DRIFTS EAST. KSAW SHOULD ALSO BECOME IMPACTED BY A LAKE BREEZE FROM LAKE MI THIS AFTERNOON. EXPECT A LINE OF MVFR/VFR CLOUDS CURRENTLY EXTENDING ALONG I-29 TO MOVE INTO WESTERN UPPER MI SUN AFTERNOON WITH THE HIGH MOVING EAST...THOUGH PROBABLY NOT MAKING IT INTO CMX UNTIL CLOSER TO 00Z. && .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. && $$ SHORT TERM/AVIATION/MARINE...AJ LONG TERM...KC mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 130 PM EDT SAT JUL 21 2007 UPDATED AVIATION DISCUSSION FOR 18Z TAFS .DISCUSSION (457 AM EDT)... THE MAIN FORECAST CONCERN DEALS WITH PCPN CHCS SUN NIGHT INTO TUE. WATER VAPOR LOOP...RUC ANALYSIS AND 00Z RAOB PLOTS SHOW AN AMPLIFIED UPR RIDGE BUILDING FROM THE PLAINS INTO THE WESTERN GREAT LAKES. AT THE SFC HIGH PRES IS CENTERED OVER ERN UPR MI MAINTAINING CLEAR SKIES ACROSS THE REGION EARLY THIS MORNING. SUNNY SKIES AND MIXING OF 850 MB TEMPS 12-14C WILL ALLOW INLAND HIGHS TO REACH THE UPR 70S AND LOWER 80S TODAY. WEAK PRES GRADIENT WITH THE PROXIMITY OF THE SFC HIGH WILL ALLOW FOR LAKE BREEZE CIRCULATIONS TO KEEP TEMPS SLIGHTLY COOLER NEAR THE GREAT LAKES SHORELINES. AS THE SFC HIGH SLIDES INTO THE LOWER GREAT LAKES...A BIT STRONGER SW FLOW WILL DEVELOP BEHIND IT OVER UPR MI TONIGHT. EXPECT THE LOWEST TEMPS (AROUND 50F) OVER THE INTERIOR SCNTRL AND E COUNTIES CLOSER TO WEAKER PRES GRADIENT AND LOWER PWAT AIR ASSOCIATED WITH HI PRES CENTER. LOOK FOR A MOSUNNY AND WARMER DAY ON SUN WITH ANTICYCLONIC SW FLOW AROUND HI PRES OVER LAKE HURON. H85 TEMPS FCST TO RISE TO 14C-16C...AND MIXING AOA 800 MB ON GFS FCST SDNGS SUPPORTS HI TEMPS PUSHING APPROACHING 85F OVER MUCH OF W AND CENTRAL UPR MI. MODERATION DOWNSTREAM OF LAKE MI WILL KEEP TEMPS A FEW DEGREES COOLER THERE. MODELS STILL PERSIST ON BRINGING STRONG 850 MB THETA-E ADVECTION AND HIGHER PWATS (> 1.5 INCHES) INTO WRN COUNTIES SUN NIGHT INTO MON AHEAD OF SHRTWV LOBE RIDING OVER TOP OF PLAINS RDG. KEPT GOING SLIGHT CHC POPS FOR THE WRN COUNTIES SUN NIGHT AND THEN SPREAD SLIGHT CHC POPS INTO CENTRAL AND ERN COUNTIES ON MON AS HIGHER PWAT/THETA-E AIR ADVANCE E. 00Z GFS/NAM AND CANADIAN MODELS ALL SEEM TO SUGGEST HIGHER PWAT/THETA-E AIR AND SFC BOUNDARY WILL LINGER INTO TUE WITH CUT-OFF LOW DRIFTING WWD INTO THE OH VALLEY/LWR GRT LKS. THUS...HAVE EXTENDED THE SLIGHT CHC POP FOR MON NIGHT INTO TUE EVENING ACROSS THE ENTIRE CWFA. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... HIGH PRESSURE OVER THE AREA WITH PLENTY OF DRY AIR WILL KEEP SKIES CLEAR INTO SUN MORNING. KCMX SHOULD SEE A LAKE BREEZE FROM THE E SET UP THIS AFTERNOON...THEN A QUICK RETURN TO A SW DIRECTION TONIGHT AS THE HIGH SLOWLY DRIFTS EAST. KSAW SHOULD ALSO BECOME IMPACTED BY A LAKE BREEZE FROM LAKE MI THIS AFTERNOON. EXPECT A LINE OF MVFR/VFR CLOUDS CURRENTLY EXTENDING ALONG I-29 TO MOVE INTO WESTERN UPPER MI SUN AFTERNOON WITH THE HIGH MOVING EAST...THOUGH PROBABLY NOT MAKING IT INTO CMX UNTIL CLOSER TO 00Z. && .MARINE (FOR 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... HIGH PRESSURE OVER THE UPPER GREAT LAKES WILL BUILD ACROSS THE REST OF THE GREAT LAKES TODAY. LOW PRESSURE TROUGH MOVING ACROSS NORTHERN ONTARIO LATE SUN INTO SUN NIGHT MAY TEMPORARILY INCREASE PRESSURE GRADIENT ENOUGH TO ALLOW FOR S WINDS TO INCREASE ABOVE 20 KT ON EASTERN SECTIONS OF LK SUPERIOR. RELAXING GRADIENT ON MON WILL RESULT IN SOUTH TO SOUTHWEST WINDS LESS THAN 20 KT THROUGH THE MIDDLE OF NEXT WEEK. && $$ DISCUSSION...VOSS AVIATION...AJ MARINE...JLA mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HASTINGS NE 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. && .AVIATION...THERE COULD BE AN ISOLATED SHOWER THIS AFTERNOON ACROSS PORTIONS OF SOUTH CENTRAL NEBRASKA...BUT THINK COVERAGE WILL BE LOW ENOUGH TO LEAVE OUT OF THE KGRI TERMINAL. LOW LEVEL MOISTURE REMAINS IN PLACE TONIGHT WHICH COULD AGAIN LEAD TO SOME LIGHT FOG OR LOW CLOUDS. IT APPEARS THE BETTER LOW LEVEL SATURATION OCCURS ACROSS EASTERN NEBRASKA...SO WILL ONLY GO WITH SCATTERED LOWER CLOUDS FOR NOW. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM/AVIATION...KING LONG TERM...KISNER ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HASTINGS NE 1227 PM CDT SAT JUL 21 2007 .AVIATION...THERE COULD BE AN ISOLATED SHOWER THIS AFTERNOON ACROSS PORTIONS OF SOUTH CENTRAL NEBRASKA...BUT THINK COVERAGE WILL BE LOW ENOUGH TO LEAVE OUT OF THE KGRI TERMINAL. LOW LEVEL MOISTURE REMAINS IN PLACE TONIGHT WHICH COULD AGAIN LEAD TO SOME LIGHT FOG OR LOW CLOUDS. IT APPEARS THE BETTER LOW LEVEL SATURATION OCCURS ACROSS EASTERN NEBRASKA...SO WILL ONLY GO WITH SCATTERED LOWER CLOUDS FOR NOW. && .PREV DISCUSSION... /ISSUED 402 AM CDT SAT JUL 21 2007/ DISCUSSION...PAST EVENING UPPER AIR DATA ALONG WITH EARLY MORNING WATER VAPOR IMAGERY CONTINUES TO SHOW A LARGE RIDGE SITTING ACROSS THE CENTRAL CONUS. SEVERAL SMALL BUT POTENT WAVES CAN BE SEEN ROTATING AROUND THE PERIPHERY OF THIS RIDGE. LATEST SURFACE ANALYSIS SHOWS A STATIONARY FRONT STRETCHING FROM SOUTHEAST KANSAS INTO WESTERN NEBRASKA. RUC ANALYSIS DATA SHOWS MODEST 850MB THETA-E ADVECTION EAST OF THE SURFACE FRONT WHICH CONTINUES TO TRIGGER SOME WEAK ISOLATED CONVECTION ACROSS EASTERN KS INTO WESTERN IA. A HOT AND GENERALLY DRY PATTERN WILL TAKE HOLD OF THE REGION TODAY INTO TONIGHT AS THE UPPER RIDGE REMAINS IN CONTROL OF THE AREA. THIS WILL ALLOW THE AFOREMENTIONED STATIONARY FRONT TO CONTINUE LIFTING SLOWLY NORTHEAST ACROSS THE REGION TODAY. ALTHOUGH LOW LEVEL FORCING ALONG THIS BOUNDARY WILL BE WEAK AT BEST...CAPE VALUES OF 1500-2000 J/KG ALONG WITH WEAK CAPPING COULD TRIGGER A FEW SHOWERS EAST OF A HEBRON TO BELOIT LINE THIS AFTERNOON TO EARLY EVENING. OTHERWISE...LOOK FOR STRATUS ACROSS PORTIONS OF THE REGION THIS MORNING TO SLOWLY GIVE WAY TO A MOSTLY CLEAR TO PARTLY CLOUDY SKY AS TEMPERATURES CLIMB INTO THE UPPER 80S TO MID 90S. SUNDAY IS THEN SHAPING UP TO BE ANOTHER HOT AND GENERALLY DRY DAY ACROSS THE AREA ALTHOUGH THE UPPER RIDGE IS SHOWN TO BEGIN RETROGRADING BACK INTO THE ROCKIES AND INTERMOUNTAIN WEST DURING THIS TIME FRAME. ALTHOUGH BETTER LOW LEVEL FORCING ON SUNDAY WILL REMAIN ACROSS THE HIGH PLAINS CLOSER TO THE LEE TROUGH...A SMALL BUT POTENT WAVE SLIDING SOUTH ALONG THE FRONT SIDE OF THE UPPER RIDGE MAY TRIGGER SOME ISOLATED CONVECTION. BEST CHANCE FOR THIS CONVECTION LOOKS TO BE EAST OF A YORK TO BELOIT LINE. WILL AIM FOR AFTERNOON HIGHS IN THE LOWER TO MID 90S. AS THE REGION HEADS INTO MONDAY THE UPPER RIDGE BEGINS TO BUILD BACK INTO THE NORTHERN PLAINS WHILE A POSITIVELY TITLED UPPER TROUGH OVER THE EASTERN CONUS BEGINS TO BACK INTO THE LOWER TO MID MS RIVER VALLEY. THIS WILL KEEP THE FORECAST AREA ON THE UNSETTLED EASTERN EDGE OF THE UPPER RIDGE. AS WAS THE CASE ON SUNDAY...IT APPEARS ANOTHER WAVE RIDING ALONG THE FRONT SIDE OF THE RIDGE COULD TRIGGER SOME ISOLATED CONVECTION EAST OF A YORK TO BELOIT LINE. AFTERNOON TEMPERATURES WILL ALSO BE SIMILAR WITH HIGHS VARYING FROM THE LOWER TO MID 90S. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTH PLATTE NE 1132 AM CDT SAT JUL 21 2007 .UPDATE... FORECAST UPDATED TO REMOVE MORNING CLOUDS. VISIBLE SHOWS STRATUS RAPIDLY ERODING ACROSS THE NORTHEASTERN ZONES. NO OTHER CHANGES AS A WARM...HUMID AND MOSTLY SUNNY AFTERNOON APPEARS TO BE ON TRACK. && .PREV DISCUSSION... /ISSUED 344 AM CDT SAT JUL 21 2007/ DISCUSSION... UPPER LEVEL RIDGE CONTINUES TO DOMINATE THE REGION...HOWEVER LOW LEVEL MOISTURE MAKING FOR A DIFFICULT FORECAST. MAIN CONCERNS LEAN ON LOW CLOUDS AND TEMPERATURES. WITH UPPER LEVEL RIDGE REALLY NOT GOING ANYWHERE THROUGH THE FORECAST PERIOD...THE SURFACE CONDITIONS ARE THE MAIN PLAYER. SOUTHEAST WINDS HAVE USHERED EVEN MORE MOISTURE OVERNIGHT WITH DEW PTS HOVERING CLOSE TO THE 70 DEGREE MARK. WINDS HAVE KEPT UP NEAR 10 KTS THUS TEMPS NOT FALLING NOR IS FOG BELOW 4SM BEEN ABLE TO FORM. STRATUS HAS DEVELOPED ACROSS MOST OF THE EASTERN HALF OF FA...PER SAT. EXPECT LITTLE CHANGE THROUGH THE MORNING. THEN COMES THE QUESTION OF HOW LONG WILL STRATUS STICK AROUND AND WHAT EFFECT THE HIGH SURF MOISTURE PLAYS ON ATMOSPHERE TO WARM. FOR SEVERAL DAYS NOW GUIDANCE HAS BEEN TOO WARM. SUSPECT THE GUIDANCE IS FOLLOWING SEVERAL YEARS OF DROUGHT CONDITIONS AND ALLOWING FOR MORE SURFACE HEATING THAT IS POSSIBLE WITH ALL THE SURF MOISTURE. THUS WILL CONTINUE TO GO TOWARDS THE LOWER GUIDANCE VALUES. EXCEPTION WILL BE ACROSS NW FA WHERE DRIER CONDITIONS EXIST AND CLOSER TO WARMER GUIDANCE. WEAK TROF ALONG THE FRONT RANGE AND UPSLOPE FLOW TO LIKELY CONTINUE TO FIRE STORMS TO OUR WEST. NAM SUGGEST A SLIGHT EASTWARD SHIFT OF THE TROF INTO THE NORTHERN PANHANDLE LATE IN THE DAY TOMORROW. WITH HIGH MOISTURE AND HIGH TEMPS...INSTABILITY IS GREAT...HOWEVER SO IS THE CAP AS TEMPS WARM ALOFT. WENT AHEAD AND ADDED LOW POPS...SLIGHT CHANCE...ACROSS NW ZONES. SHEAR IS WEAK SO NOT EXPECTING MUCH...IF ANY...ACTIVITY TO GET GOING TO BE VERY STRONG. REMAINDER OF THE WEEK CONTINUES TO SEE ABOVE TEMPS WITH LITTLE CHANCE FOR MOISTURE. TEMPS ALOFT TO KEEP A DECENT CAP...HOWEVER LL MOISTURE COULD SEE SOME SPOTTY CU FIELDS. AVIATION... AVIATION FORECASTS REMAIN CHALLENGING. CURRENT STRATUS TRENDS ARE NOT IN AGREEMENT WITH 12KM NAM BLYR RH FCSTS. PREVAILING MVFR WITH LOCALLY IFR CIGS ARE EXPANDING ACROSS THE NORTHEASTERN HALF OF FORECAST AREA WHILE TAF SITE KVTN NOW ON WRN EDGE OF MVFR CIGS. KLBF NO LONGER NEAR STRATUS AND ANY IFR CIGS AND HAVE UPDATED SITE FOR ONLY TEMPO 4SM BR TIL 14Z. 11-3.9 MICRO SATELLITE IMAGERY AND RUC40 300-310K THETA SFC SUPPORT NORTHEASTWARD MOVEMENT OF STRATUS LEAVING KLBF FREE OF STRATUS RETURN THIS AM. THUS HAVE UPDATED KLBF TO REMOVE CIGS. ALONG TWEB ROUTE 098...MVFR CIGS WILL PREVAIL FROM NEAR KVTN TO 20 SE OF KONL TIL 14Z...THEN LIFT AND SCATTER OUT AFTER 16Z. REMINDER OF TWEB ROUTE TO KOFK WILL SEE MVFR CIGS TIL 16Z DUE TO EASTWARD EXPANSION WHILE SEGMENT WEST TO KCDR WILL REMAIN UNDER VFR TODAY. TWEB ROUTES 264 AND 274 TO REMAIN UNDER VFR CONDITIONS. CONTINUED MONITORING OF SATELLITE IMAGERY AND TAF UPDATES FOR KVTN AND PORTIONS OF TWEB ROUTE 098 REMAIN LIKELY IF TREND CONTINUES. LBF WATCHES/WARNINGS/ADVISORIES... NONE. $$ && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MASEK/KAR/JMC ne