AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 128 PM MDT TUE SEP 6 2005 .SHORT TERM (TONIGHT THROUGH THURSDAY)... A SHORTWAVE TROUGH WAS ROTATING NORTH OVER SOUTHERN UTAH THIS AFTERNOON AND WILL CONTINUE DRAWING MOISTURE AND INSTABILITY INTO THE AREA. RUC SHOWS THIS FEATURE FAIRLY WELL MATCHED WITH WV SATELLITE FEATURES. HAVE INCREASED POPS AND CLOUDS ACROSS EASTERN UTAH AND WESTERN CO FOR THE REST OF THIS AFTERNOON THROUGH MIDNIGHT. LOOKING AHEAD TO WED THROUGH THU...THE GFS SEEMS TO HAVE THE BEST HANDLE ON LARGER SCALE FEATURES. ANOTHER SURGE OF SUBTROPICAL MOISTURE SHOULD MOVE FROM NW MEXICO INTO AZ THEN NORTH TO UT/CO. NAM SHOWS THIS FEATURE BEING DRAWN SOUTH AND EAST OF THE AREA...BUT NAM HAS BEEN MISSING THESE LATELY...OFTEN BEING TOO DRY. WILL STAY WITH GFS-BASED FORECAST THROUGH THURSDAY. .LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)... MEDIUM RANGE MODELS CONTINUE TO BE IN GOOD AGREEMENT THROUGH THE END OF THIS WEEK...THEN DIFFER ONLY A LITTLE ON DETAILS THEREAFTER. FRIDAY...LOOKS LIKE THE POTENTIAL WILL EXIST FOR CONTINUED MOIST AIR MASS WITH SHORTWAVE DISTURBANCES EMBEDDED IN THE FLOW OVER OUR CWA. RAISED POPS SUCH THAT ALL ZONES HAVE AT LEAST SCATTERED CATEGORY. FRIDAY NIGHT...THOUGH MODELS APPEAR TO BE RATHER DRY FOR THIS TIME PERIOD...OUR CWA WILL REMAIN UNDER THE SAME SOUTHERLY THAT WILL LIKELY PRODUCE AT LEAST SCATTERED -TSRA ON THURSDAY AND FRIDAY. SOME NOCTURNAL ACTIVITY SHOULD BE EXPECTED...AND HAVE INTRODUCED SLIGHT CHANCE POPS TO ALL ZONES. SATURDAY...MODELS INDICATE THE WEST COAST TROUGH TO MOVE INLAND FAR ENOUGH TO LOWER H7 TEMPS OVER OUR CWA BY 2-3C. IF TIMING IS A LITTLE SLOWER THAN MODELS INDICATE...THEN OUR MAX TEMPS FOR THIS DAY WILL BE OKAY...BUT OUR POPS/WX WILL HAVE TO BE INCREASED. IF MODEL TIMING OF TROF IS GOOD...THEN OUR MAX TEMPS WILL HAVE TO BE LOWERED ABOUT 5F ACROSS THE BOARD. SINCE CONFIDENCE ON TIMING NOT GREAT...WILL LEAVE CURRENT GRIDS ALONE AT THIS TIME. SATURDAY NIGHT THROUGH TUESDAY...IF MODEL TIMING IS CORRECT...THEN OUR CWA SHOULD BE UNDER A DRIER SOUTHWEST FLOW BY SATURDAY NIGHT... WITH SUBTROPICAL PLUME SHIFTING TO THE EAST AND MOISTURE ASSOCIATED WITH UPPER LOW REMAINING TO NW. THIS GENERAL SITUATION PROGGED TO NOT CHANGE MUCH. HOWEVER...OUR CWA COULD BE RECIPIENT OF SOME UPPER LOW MOISTURE AS VORT SPOKES ROTATE ACROSS OUR CWA...MAINLY EFFECTING NW PORTION OF OUR CWA. FORECASTED MAX TEMPS DURING THIS TIME PERIOD APPEAR TO BE IN BALL PARK. .GJT WATCHES/WARNINGS/ADVISORIES... .CO...NONE. .UT...NONE. && CC/JRP co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 920 PM CDT TUE SEP 6 2005 .DISCUSSION... .UPDATE... MAIN FOCUS OF EVE UPDATE WAS PCPN TRENDS. SVRL SHRT WVS CURRENTLY UPSTREAM ACRS RCKYS INTO NE BUT NOT APCHG QUICKLY. SEPARATE CLUSTERS OF PCPN OVR N CNTRL AND SERN NE MOVG SLOWLY. BOTH SYSS SEEM TO BE RESPONDING MORE TO KINEMATIC RATHER THAN THERMODYNAMIC FORCING JUST AHD OF THEIR PARENT WVS. NRN MCS STGR AS ITS IN AN ELEVATED INSTABILITY AXIS INVOF SFC FNTL BNDRY WHICH EXTENDS FM KONL-KSUX-KAEL AT 01Z. SHOWALTERS -4 TO -7 IN THESE AREAS. MINIMAL SVR THREAT HWVR AS SHEAR AND WND FIELDS WEAK. HAVE TO APCH 7KM AT NLG PROFILER TO GET WNDS AOA 20KTS AND WEAK COLD ADVCTN IS APPARENT IN 1KM-4KM LYR. SIMILAR LGT WNDS AT KOAX SOUNDING AND SLA PROFILER WITH EITHER WEAK COOL OR NEUTRAL ADVCTN. ANY PCPN WE WOULD GET WOULD SEEM TO BE FAIRLY ELEVATED AND LIKELY TAKE AWHILE TO GET HERE. RUC 305-315K ISENT LYR KEEPS MSTR TRANSPORT AND CNVGNC MAINLY TO OUR N AND W OVNGT WITH HINT AT PCPN EXPANDING INVOF FNTL BNDRY ALA GFS. THUS HAVE KEEP FCST DRY THRU 08Z AND THEN GONE WITH SLGT TO CHC POPS TWRD DAYBREAK WITH HIGHEST N AND W. LTL CHG TO OTHER FIELDS. .PREV DISCUSSION... MAIN FORECAST CONCERNS INCLUDE PRECIP TRENDS AND SVR/HEAVY RAIN POTENTIAL THROUGH THURSDAY. SFC COLD FRONT WILL BE THE FOCUS FOR SCT SHRA/TSRA ACTIVITY ACROSS MUCH OF NORTHERN IA FROM TNT THRU EARLY WED. 19Z ANALYSIS SHOWS CLD FRONT BEGINNING TO PUSH INTO XTREME NW IA...EXTD FM KMSP SWWD THRU KSPW. A FEW ELV TSRA HAVE ALREADY DEVELOPED ALONG THE BNDRY NEAR KSUX WHERE CIN HAS VIRTUALLY BEEN ERODED. INSTABILITY AXIS INVOF CLD FRONT WILL CONTINUE TO CREEP INTO NW IA THROUGH LATE THIS EVE WITH LLVL MOISTURE ALSO POOLING IN ADVANCE OF THE SFC FEATURE. WITH CAP WEAKENING AND MODERATE INSTABILITY (1500-1800 J/KG) PROGGED ACROSS THE NORTHERN TIER...CONVECTION SHOULD INITIATE NEAR/AHEAD OF THE FRONT AS IT MOVES INTO NW IA. ALTHOUGH THE 18Z NAM HAS TRENDED DRIER...SREF/RUC AND PREVIOUS NAM RUN IN FAIRLY GOOD AGREEMENT WITH DEVELOPING PRECIP ACROSS THE NORTH. BOOSTED POPS TO LIKELY CATEGORY NORTH AFTER MIDNIGHT...WHERE HEAVIER RAIN SHOULD OCCUR. UPDATED HWO ISSUED TO MENTION MARGINAL SEVERE HAIL THREAT NW THRU SUNSET...ALONG WITH THE POSSIBILITY OF ISOLATED 1/2 TO 1.5 INCH RAINFALL AMOUNTS. FLASH FLOODING NOT EXPECTED TO BE AN ISSUE OVERNIGHT. ON WEDNESDAY...BOTH THE NAM/GFS INDICATE SEVERAL PIECES OF ENERGY MOVING THROUGH THE REGION AS THE FRONT SAGS INTO IOWA. FAVORED THE NW 2/3 OF THE FORECAST AREA FOR HIGHEST POPS. SFC RIDGING SHOULD KEEP MUCH OF THE CWA DRY WEDNESDAY NIGHT. THE GFS IS SUGGESTING SOME WAA PRECIP LATE WEDNESDAY NIGHT IN THE SOUTH. MAINTAINED LOW CHC POPS FOR COORDINATION PURPOSES. THE OVERALL SEVERE WEATHER THREAT LOOKS RATHER LOW FOR WEDNESDAY. LATE WEDNESDAY NIGHT...THE NAM DEVELOPS AN MCS ACROSS SOUTH DAKOTA AND BARRELS IT THROUGH IOWA DURING THE DAY ON THURSDAY INTO THURSDAY EVENING. THE GFS ALSO GENERATES PRECIP OVER THE NORTH DURING THE AFTERNOON. ENOUGH CONFIDENCE TO RAISE POPS TO LIKELY CATEGORY OVER THE NORTH HALF. THE BEST POTENTIAL IS EXPECTED TO BE THURSDAY...WITH POSSIBLE MCS REMNANTS IN THE MORNING...AND RE-FIRING IN THE LATE AFTERNOON/EARLY EVENING ALONG THE WARM FRONT. THERE IS STILL A HEAVY RAIN POTENTIAL THURSDAY...BUT 1 HR FFG VALUES OF 2 TO 3 INCHES SHOULD PRECLUDE ANY SIGNIFICANT FLOODING. TEMPERATURES WILL BE A CHALLENGE THROUGH THE PERIOD. FAVORED THE WARMER END OF MOS GUIDANCE FOR MINS THROUGH FRIDAY...AND STAYED CLOSE TO THE COOLER MET MOS FOR HIGH TEMPS GIVEN THE CLOUDS/PRECIP EXPECTED. TEMPS SHOULD REBOUND INTO THE MID/UPPER 80S W/SW PORTIONS FRIDAY AS UPPER RIDGE BUILDS IN. IN THE LATER PERIODS (SAT-TUES)...THE MEDIUM RANGE MODELS ARE IN DECENT AGREEMENT IN DEPICTING A LARGE UPPER RIDGE ACROSS THE CENTRAL AND EASTERN U.S. WITH SW FLOW. THE DGEX/GFS SUGGEST THE PLAINS FRONT WILL APPROACH NW IA LATE IN THE PERIOD AND ENSEMBLE POPS HAVE ALSO CREPT ABOVE CLIMO. THUS...HAVE ADDED SOME SMALL POPS IN THE NORTH MON NITE INTO TUES. PERSISTENT SOUTH TO SOUTHWEST FLOW WILL KEEP TEMPERATURES WELL ABOVE NORMAL THROUGH THE EXTENDED...WITH HIGHS IN THE 80S AND LOWS MAINLY IN THE LOW TO MID 60S. STAYED AT OR SLIGHTLY ABOVE OPERATIONAL GFS MOS. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ STEINBUGL/KINNEY/SMALL ia AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 325 PM CDT TUE SEP 6 2005 .DISCUSSION... MAIN FORECAST CONCERNS INCLUDE PRECIP TRENDS AND SVR/HEAVY RAIN POTENTIAL THROUGH THURSDAY. SFC COLD FRONT WILL BE THE FOCUS FOR SCT SHRA/TSRA ACTIVITY ACROSS MUCH OF NORTHERN IA FROM TNT THRU EARLY WED. 19Z ANALYSIS SHOWS CLD FRONT BEGINNING TO PUSH INTO XTREME NW IA...EXTD FM KMSP SWWD THRU KSPW. A FEW ELV TSRA HAVE ALREADY DEVELOPED ALONG THE BNDRY NEAR KSUX WHERE CIN HAS VIRTUALLY BEEN ERODED. INSTABILITY AXIS INVOF CLD FRONT WILL CONTINUE TO CREEP INTO NW IA THROUGH LATE THIS EVE WITH LLVL MOISTURE ALSO POOLING IN ADVANCE OF THE SFC FEATURE. WITH CAP WEAKENING AND MODERATE INSTABILITY (1500-1800 J/KG) PROGGED ACROSS THE NORTHERN TIER...CONVECTION SHOULD INITIATE NEAR/AHEAD OF THE FRONT AS IT MOVES INTO NW IA. ALTHOUGH THE 18Z NAM HAS TRENDED DRIER...SREF/RUC AND PREVIOUS NAM RUN IN FAIRLY GOOD AGREEMENT WITH DEVELOPING PRECIP ACROSS THE NORTH. BOOSTED POPS TO LIKELY CATEGORY NORTH AFTER MIDNIGHT...WHERE HEAVIER RAIN SHOULD OCCUR. UPDATED HWO ISSUED TO MENTION MARGINAL SEVERE HAIL THREAT NW THRU SUNSET...ALONG WITH THE POSSIBILITY OF ISOLATED 1/2 TO 1.5 INCH RAINFALL AMOUNTS. FLASH FLOODING NOT EXPECTED TO BE AN ISSUE OVERNIGHT. ON WEDNESDAY...BOTH THE NAM/GFS INDICATE SEVERAL PIECES OF ENERGY MOVING THROUGH THE REGION AS THE FRONT SAGS INTO IOWA. FAVORED THE NW 2/3 OF THE FORECAST AREA FOR HIGHEST POPS. SFC RIDGING SHOULD KEEP MUCH OF THE CWA DRY WEDNESDAY NIGHT. THE GFS IS SUGGESTING SOME WAA PRECIP LATE WEDNESDAY NIGHT IN THE SOUTH. MAINTAINED LOW CHC POPS FOR COORDINATION PURPOSES. THE OVERALL SEVERE WEATHER THREAT LOOKS RATHER LOW FOR WEDNESDAY. LATE WEDNESDAY NIGHT...THE NAM DEVELOPS AN MCS ACROSS SOUTH DAKOTA AND BARRELS IT THROUGH IOWA DURING THE DAY ON THURSDAY INTO THURSDAY EVENING. THE GFS ALSO GENERATES PRECIP OVER THE NORTH DURING THE AFTERNOON. ENOUGH CONFIDENCE TO RAISE POPS TO LIKELY CATEGORY OVER THE NORTH HALF. THE BEST POTENTIAL IS EXPECTED TO BE THURSDAY...WITH POSSIBLE MCS REMNANTS IN THE MORNING...AND RE-FIRING IN THE LATE AFTERNOON/EARLY EVENING ALONG THE WARM FRONT. THERE IS STILL A HEAVY RAIN POTENTIAL THURSDAY...BUT 1 HR FFG VALUES OF 2 TO 3 INCHES SHOULD PRECLUDE ANY SIGNIFICANT FLOODING. TEMPERATURES WILL BE A CHALLENGE THROUGH THE PERIOD. FAVORED THE WARMER END OF MOS GUIDANCE FOR MINS THROUGH FRIDAY...AND STAYED CLOSE TO THE COOLER MET MOS FOR HIGH TEMPS GIVEN THE CLOUDS/PRECIP EXPECTED. TEMPS SHOULD REBOUND INTO THE MID/UPPER 80S W/SW PORTIONS FRIDAY AS UPPER RIDGE BUILDS IN. IN THE LATER PERIODS (SAT-TUES)...THE MEDIUM RANGE MODELS ARE IN DECENT AGREEMENT IN DEPICTING A LARGE UPPER RIDGE ACROSS THE CENTRAL AND EASTERN U.S. WITH SW FLOW. THE DGEX/GFS SUGGEST THE PLAINS FRONT WILL APPROACH NW IA LATE IN THE PERIOD AND ENSEMBLE POPS HAVE ALSO CREPT ABOVE CLIMO. THUS...HAVE ADDED SOME SMALL POPS IN THE NORTH MON NITE INTO TUES. PERSISTENT SOUTH TO SOUTHWEST FLOW WILL KEEP TEMPERATURES WELL ABOVE NORMAL THROUGH THE EXTENDED...WITH HIGHS IN THE 80S AND LOWS MAINLY IN THE LOW TO MID 60S. STAYED AT OR SLIGHTLY ABOVE OPERATIONAL GFS MOS. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ STEINBUGL/KINNEY ia AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1136 AM CDT TUE SEP 6 2005 .SHORT TERM (REST OF TODAY)... WL ISSUE UPDATE MAINLY TO DEC POPS A BIT FROM EARLY THIS AFT->EVE (MAINLY FROM HIGHWAY 20 SOUTH) AND FRESHEN UP MORNING WORDING. LEFTOVER BNDRYS INITIATING ISOLD SHRA WHICH CONT TO DRIFT INTO WCENT IA BUT QUICKLY DISSIPATE AS THEY TRAVERSE EWRD INTO STABLE AIR. ALSO TWEAKED A FEW SKY/TEMP GRIDS BASED ON HOURLY TRENDS. FORECAST CONSIDERATIONS INCLUDE TIMING AND DEVELOPMENT OF PRECIP MAINLY ACROSS THE NORTH LATER THIS AFT/EVE COINCIDING WITH DIURNAL MAX AND INC INSTABILITY. AS SFC CLD FRONT WORKS FURTHER SEWD...CAP SHOULD SLOWLY ERODE AT LEAST OVR NW IA WITH RUC PROGGING 1500-2000 J/KG ML CAPE FROM 21-00 UTC. A FEW CELLS GOING UP TO MY NW NOW...S OF KFSD AND N OF KOFK. RUC/NAM HAVE DECENT HANDLE ON PRECIP TRENDS ATTM. WILL CONT TO MONITOR AND ASSESS FOR AFT PACKAGE. && .PREV DISCUSSION... (ISSUED 338 AM CDT TUE SEP 6 2005) DISCUSSION... FORECAST FOCUS IS ON THE NEXT THREE DAYS AS A SLOW MOVING COLD FRONT STALLS ACROSS THE MIDWEST THEN LIFTS BACK TO THE NORTH AS A WARM FRONT TOWARD THE END OF THE WEEK. IN THE NEAR TERM THUNDERSTORMS HAVE ENTERED NW IA. THIS LINE OF STORMS CONTINUES TO MOVE SE INTO A LESS FAVORABLE ENVIRONMENT WITH LESS ELEVATED INSTABILITY AND WEAK SHEAR. CORFIDI VECTORS SUGGEST THAT THE LINES ADVANCE TO THE SE WILL BEGIN TO SLOW AND MAY EVEN HANG UP OVER THE NW 1/2 FOR THE MORNING HOURS. NO SIGNS OF THIS YET. DUE TO THIS POTENTIAL THOUGH AND EXPECTED CLOUD COVER...HAVE INCHED HIGHS TODAY DOWN A FEW DEGREES OVER THE NORTH. A STRONG SHORT WAVE PUNCHING ACROSS THE SRN CANADIAN PROVINCES HAS FLATTENED THE MID LEVEL RIDGE WITH A MORE ZONAL FLOW EXPECTED THROUGH THURSDAY. THIS WILL ALLOW THE COLD FRONT TO STALL IN THE AREA AND BRING SEVERAL CHANCES FOR THUNDERSTORMS DURING THE PERIOD. HEAVY RAINFALL WILL BE A CONCERN WITH UNSEASONABLY HIGH PWATS AND THE POTENTIAL FOR SLOW MOVING STORMS TRAINING ALONG THE BOUNDARY...HOWEVER GIVEN THE OVERALL DRY WEATHER RECENTLY...DO NOT EXPECT WIDESPREAD PROBLEMS AT THIS POINT. SIMILAR TO TODAY...CLOUD TRENDS WILL BE PROBLEMATIC WED AND THU AND WILL MAKE FOR A DIFFICULT TEMPERATURE FORECAST. NORTHERN AREAS LIKELY TO REMAIN CLOUDY AND COOL ON WEDNESDAY THEN A FEW MORE BREAKS ON THURSDAY. THE UPPER RIDGE BEGINS TO REASSERT ITSELF TOWARD THE END OF THE WEEK WITH THE BOUNDARY LIFTING BACK NORTH OF IOWA AS A WARM FRONT. DRY AND WARM FOR THE WEEKEND. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...STEINBUGL ia AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WICHITA KS 910 PM CDT TUE SEP 6 2005 .DISCUSSION... DO NOT PLAN ON ANY UPDATES TO ONGOING FORECAST AT THIS TIME. UPPER AIR ANALYSIS SHOWS 700MB FLOW STARTING TO VEER INCREASING THETA-E ADVECTION ACROSS CENTRAL KANSAS. RUC ANALYSIS ALSO INCREASING LIFT ON THE 310K SURFACE. THIS HAS RESULTED IN SOME WEAK ECHOS ACROSS CENTRAL KANSAS. OVER THE NEXT FEW HOURS AM EXPECTING SHOWER AND STORM COVERAGE TO INCREASE. THE PREVIOUS FORECAST LOOKS TO HAVE A GOOD HANDLE ON THIS WITH INCREASING RAIN CHANCES AFTER 06Z. && LAWSON .PREV DISCUSSION... /ISSUED 312 PM CDT TUE SEP 6 2005/ DISCUSSION... FORECAST CONCERNS WILL FOCUS ON PRECIPITATION CHANCES TONIGHT THROUGH WEDNESDAY NIGHT/EARLY THURSDAY, MAINLY ACROSS CENTRAL KANSAS. ATTENTION THEN TURNS TOWARD WARMING TREND AND AMPLIFYING WESTERN CONUS TROUGH INTO EARLY NEXT WEEK. ONGOING ELEVATED SHOWER/THUNDERSTORM ACTIVITY OVER CENTRAL AND SOUTH CENTRAL KANSAS IS BEING SUSTAINED BY A SUBTLE MCV, WEAK DIFFLUENT/DIVERGENT FLOW ALOFT AND 850-700MB WARM/MOIST ADVECTION. EXPECTING ACTIVITY TO LINGER/REDEVELOP OVER CENTRAL KANSAS THROUGH THE OVERNIGHT HOURS, AS 700MB WARM/MOIST ADVECTION CONTINUES. HOWEVER, SUBSIDENCE IN WAKE OF MCV MAY INHIBIT FURTHER DEVELOPMENT THIS EVENING, BUT SHOWER/THUNDERSTORM COVERAGE SHOULD INCREASE AFTER MIDNIGHT, MAINLY OVER CENTRAL KANSAS. 700MB WARM/MOIST ADVECTION IS EXPECTED TO REMAIN OVER CENTRAL KANSAS THROUGH AT LEAST WEDNESDAY NIGHT/EARLY THURSDAY, PROMPTING CONTINUED SHOWER/THUNDERSTORM CHANCES. DUE TO LIMITED INSTABILITY & SHEAR, WEAK FORCING AND NATURE OF THE ELEVATED CONVECTION, AM NOT EXPECTING SEVERE THUNDERSTORMS. FOR THURSDAY INTO THURSDAY NIGHT, ETA PROGRESSES A WEAK COLD FRONT INTO NORTHERN KANSAS. THIS SOLUTION SEEMS UNREASONABLE GIVEN MID/UPPER ATMOSPHERIC RIDGING OVER THE PLAINS. FURTHERMORE, OTHER OPERATIONAL MODELS DO NOT SUPPORT THIS SOLUTION. OTHERWISE, DRY AND RELATIVELY WARM CONDITIONS ARE EXPECTED TO CONTINUE THROUGH AT LEAST THE WEEKEND, AS AN UNSEASONABLY STRONG MID/UPPER LEVEL LONG WAVE TROUGH IS EXPECTED TO AMPLIFY OVER THE PACIFIC NORTHWEST, AND EVENTUALLY INTO THE WESTERN CONUS. THE INCREASE IN ATMOSPHERIC THICKNESS AND SOUTHERLY FLOW WILL WARM TEMPERATURES 90-95F...ABOUT 5-10F ABOVE NORMAL. SCATTERED AFTERNOON AND EVENING THUNDERSTORMS MAY BE A GOOD BET ALONG THE HIGH PLAINS OF WESTERN KANSAS/EASTERN COLORADO, AS A LEE TROUGH WILL REMAIN NEARLY STATIONARY FOR SEVERAL DAYS. DEPENDING ON AVAILABLE MOISTURE/INSTABILITY, IT IS CONCEIVABLE THAT SOME OF THIS ACTIVITY COULD VENTURE INTO CENTRAL KANSAS. HOWEVER, UNCERTAINTY REMAINS TOO GREAT TO INSERT POPS AT THIS TIME. PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 66 88 66 91 / 20 10 10 10 HUTCHINSON 65 86 65 89 / 30 20 20 10 NEWTON 65 87 66 90 / 20 20 20 10 ELDORADO 66 88 66 91 / 10 10 10 10 WINFIELD-KWLD 66 91 66 92 / 10 10 10 5 RUSSELL 65 85 65 89 / 40 30 30 10 GREAT BEND 65 85 65 89 / 40 30 30 10 SALINA 65 85 66 89 / 30 30 30 10 MCPHERSON 65 85 66 89 / 30 20 20 10 COFFEYVILLE 65 91 65 92 / 5 5 10 5 CHANUTE 65 90 65 92 / 5 5 10 5 IOLA 65 89 65 91 / 5 10 10 5 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ KLEINSASSER/ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DODGE CITY KS 206 PM CDT TUE SEP 6 2005 .DISCUSSION... DAYS 1-2... RUC THIS MORNING APPEARING TO HAVE A SLIGHT EDGE ON UPPER S/W TROF ASSOC W/ LEFT ENTRANCE REGION OF 25H JET STREAK WHICH WAS LOCATED OVER S/SW CO AT 12Z TUES. FOLLOWING THE RUC SOLUTION YIELDS CONVECTION DEVELOPING ALONG LEE TROF AFTER 21Z...THEN MUCH LIKE LAST NIGHT MOVING EAST AS PROGGED WAA/LLJ DEVELOPS. ON WEDNESDAY 5H RIDGE SLIDES EAST ACROSS THE TX PANHANDLE INTO OK AS NAM/GFS/UKMET ALL (TO VARIOUS DEGREES) MOVE ANOTHER 5H VORT LOBE ACROSS SE CO. DESPITE WEAK FLOW ALOFT CONVECTION ONCE AGAIN WILL BE POSSIBLE ALONG THE LEE TROF AND COLD FRONT WHICH WILL BE NEAR OUR NRN CWA BY EVENING. SHEAR AND INSTAB APPEAR TO BE MORE FAVORABLE TO OUR N/NW AS 925-85H WAA DEVELOPS IN THIS REGION WED NIGHT BUT GIVEN THE UNCERTAINTY OF LOCATION OF FRONT/TROF WILL KEEP SMALL CHC POPS IN MY NORTH LATE WED-WED NIGHT. BASED ON EXPECTED CLOUDS AND PCPN CHANCES WILL TRIM SEVERAL DEGREES OFF GUIDANCE FOLLOWING MORE OF A 9H NAM/85H GFS MIX DOWN TEMP SOLUTION FOR WED. GO WARMER ON THURSDAY BASED ON MORE CLOUDS AND SMALL CHC OF PCPN. DAYS 3-7... EXTENDED RANGE MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH MAIN SYNOPTIC FEATURES EXPECTED. DIGGING TROUGH OVER THE WESTERN U.S. WILL HELP TO AMPLIFY RIDGE THAT WILL BE PASSING OVER CWA MIDWEEK AND STALL OUT OVER THE EASTERN U.S. FOR THE DAYS 4-7 TIME FRAME. THIS WILL SETUP A SOUTH-SOUTHWESTERLY FLOW OVER THE CWA WITH WARM TEMPERATURES CONTINUING. SHOULD SEE HIGHS MAINLY IN THE LOWER 90S AT LEAST UNTIL SATURDAY WITH SOME COOLER TEMPERATURES POSSIBLE FOR END OF THE EXTENDED AS THE SOUTH-SOUTHWEST FLOW TAPS INTO SOME SUBTROPICAL MOISTURE AND BRINGS BACK A CHANCE FOR RAIN TO THE AREA. SHOULD STILL SEE HIGHS JUST A BIT ABOVE AVERAGE WITH HIGHS IN THE MID TO UPPER 80S. INCREASED DIGGING OF THE WESTERN U.S. TROUGH THROUGH DAY 10 AND A SERIES OF DISTURBANCES HELPING TO BREAK DOWN RIDGE WILL LEAD TO NEAR AVERAGE TEMPERATURES AND PRECIPITATION IN THE 8-10 DAY PERIOD. && .PRELIMINARY POINT TEMPS/POPS... DDC 64 85 63 88 / 30 30 0 0 GCK 63 86 64 89 / 40 20 20 0 EHA 63 80 63 86 / 50 20 10 0 LBL 64 84 63 87 / 30 20 0 0 HYS 64 85 63 90 / 40 30 40 0 P28 65 88 64 89 / 20 20 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 18/28 ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1055 PM EDT TUE SEP 6 2005 .UPDATE...COLD FRONT FROM NRN LAKE SUPERIOR TO SRN MN THIS EVENING WHILE BAND OF MID/UPPER CLOUDINESS ROLLING THROUGH NRN MICHIGAN. LATEST RUC/SATELLITE ANALYSIS AND UPPER AIR PLOTS SUGGESTING THIS HIGHER LEVEL MOISTURE WILL SLIDE ACROSS THE EASTERN CWA OVERNIGHT LIKELY CLINGING TO AREAS NEAR THE SAG BAY BY DAYBREAK. FURTHER UPSTREAM IN NW WI/SRN MN...AHEAD OF AFOREMENTIONED BOUNDARY...THE ANALYSIS REVEALS LOWER LEVEL MOISTURE MORE PLENTIFUL. THIS NOT SUPPORTED BY OBS SO MUCH...BUT AS ATMOSPHERE COOLS THROUGH THE NIGHT...WOULD EXPECT TO SEE A GRADUAL INCREASE IN 4-6KFT CLOUDS THAT WILL SPREAD INTO PORTIONS OF OUR NRN CWA LATE. HELPING THE CAUSE WILL BE SOME WEAK TO MODERATE -DIVQ IN THE H8-H7 LAYER. MOISTURE DOES NOT LOOK DEEP ENOUGH FOR ANY GREAT CHANCE OF PRECIPITATION EVEN WITH THE FRONT TRYING TO WORK INTO EASTERN UPPER/STRAITS REGION BY DAYBREAK. WILL DROP ALL POPS FOR THE NIGHT...AS ANYTHING THAT DEVELOPS DOES NOT LOOK TO BE MORE THAN A FEW SPRINKLES OR VERY ISOLATED LIGHT SHOWERS ALONG THE FRONT. THE CLOUDS AND INCREASE IN H8 WINDS TO 20KTS OR SO WILL KEEP MIN TEMPS UP IN THE LOWER 60S FOR MANY AREAS TONIGHT. THE COOLEST LOCALES LOOK TO BE IN THE SE CWA WHERE LOWEST LEVEL MOISTURE WILL ARRIVE LAST. DEW POINTS IN THIS REGION ARE STILL IN THE UPPER 50S. BETTER CHANCE FOR RAIN/POTENTIAL THUNDER MAY BE TOMORROW AFTERNOON IN NRN LOWER WHILE FRONT SETTLES IN...BETTER SFC TD'S...AXIS OF MAX THETA-E OVERHEAD WITH STEEPER MID LEVEL LAPSE RATES. SMD && .PREV DISCUSSION ISSUED AT 415 PM EDT TUE SEP 6 2005 DISCUSSION...SURFACE RIDGING HAS PUSHED EAST OF THE REGION AS THE UPSTREAM COOL FRONT LEANS INTO THE REGION. FRONT CURRENTLY EXTENDS FROM ERN LAKE SUPERIOR INTO SE MINNESOTA. WDLY SCT SHRA CONTINUE TO DEVELOP AHEAD OF THIS BOUNDARY WITHIN A NARROW BAND OF LIMITED MOISTURE AND WEAK INSTABILITY. SO FAR...THE SHOWERS HAVE ONLY HELD TOGETHER ACROSS ERN UPR MICHIGAN...AND HAVE DISSIPATED BEFORE REACHING NW LOWER MICHIGAN DUE TO DRY LOW LEVEL AIR AND A LACK OF SUFFICIENT INSTABILITY WITHIN THIS REGION. POPS AND THE POTENTIAL FOR THUNDER WILL REMAIN THE PRIMARY FORECAST ISSUE FOR THE NEXT 24 HOURS. TONIGHT...WEAK SLOW-MOVING COOL FRONT WILL LAY INTO THE CWA THROUGHOUT THE NIGHT...REACHING THE STRAITS BY 12Z. AGAIN... INSTABILITY WILL BE MINIMAL BUT STILL PRESENT ALONG AND AHEAD OF THE FRONT WITHIN THE NARROW 850 MB THETA E RIDGE AXIS. UPPER SUPPORT AND WIND FIELDS WILL REMAIN TOO WEAK FOR ANY CHANCE OF A SEVERE TSRA THREAT. HOWEVER...WOULD NOT RULE OUT THE POSSIBILITY THAT A FEW OF THE SHOWERS THAT DEVELOP ALONG AND AHEAD OF THE FRONT FURTHER DEVELOP INTO THUNDERSTORMS GIVEN THE PRESENCE OF SOME INSTABILITY. THE CHANCE OF SHRA/TSRA WILL GRADUALLY SPREAD FROM NW TO SE ACROSS THE CWA DURING THE NIGHT. LOCATIONS SE OF A LINE FROM APN TO GOV TO CAD WILL LIKELY NOT SEE ANY PRECIP UNTIL THE OVERNIGHT HOURS. OTHERWISE...SKIES WILL REMAIN PARTLY TO MOSTLY CLOUDY. OVERNIGHT LOWS WILL DROP INTO THE UPPER 50S AND LOWER 60S. WILL CANCEL THE SCA FOR NEARSHORE ZONES AS WINDS AND WAVES HAVE FALLEN BELOW SCA CRITERIA IN RESPONSE TO LOOSENING OF THE SURFACE PRESSURE GRADIENT WITH THE APPROACH OF THE COOL FRONT. WEDNESDAY...COOL FRONT WILL MAKE LIMITED SE PROGRESS THROUGHOUT THE DAY...REACHING THE SRN HALF OF THE CWA BY LATE AFTERNOON. LITTLE WILL CHANGE WITHIN THE RIBBON OF MOISTURE AND INSTABILITY AHEAD OF THE FRONT. THUS...POTENTIAL FOR CONVECTIVE DEVELOPMENT (INCLUDING A FEW THUNDERSTORMS) WILL CONTINUE BUT ORGANIZATION AND INTENSITY WILL BE WEAK. CHANCES OF PRECIP FOR ERN UPR MICHIGAN WILL END (FOR THE MOST PART) EARLY IN THE MORNING AS THE FRONT AND ASSOCIATED FEATURES SINKS FURTHER SOUTH AWAY FROM THAT REGION. NRN LOWER MICHIGAN WILL MAINTAIN A CHANCE OF PRECIP THROUGHOUT THE DAY. SKIES WILL REMAIN PARTLY TO MOSTLY CLOUDY. HIGH TEMPS WILL BE COOLER THAN THE PREVIOUS 2 DAYS...BUT SHOULD STILL REACH INTO THE 70S. RELATIVELY FLAT/PROGRESSIVE FLOW NOW ACROSS NORTH AMERICA FORECAST TO TRANSITION INTO A SHARP WEST COAST TROUGH-EAST COAST RIDGE PATTERN LATE THIS WEEKEND AND INTO EARLY NEXT WEEK. APPEARS THAT SUMMER WILL CONTINUE TO HANG ON ACROSS NORTHERN MICHIGAN INTO MID SEPTEMBER WITH TEMPS AGAIN PUSHING THE 80 DEGREE MARK BY THE END OF THE WEEKEND AND EARLY NEXT WEEK. OVERALL...A DRY WEATHER PATTERN ANTICIPATED WITH A FEW OPPORTUNITIES FOR RAINFALL LATE THIS WEEK AS A WARM AIR PUSHES INTO THE REGION...AND LATE IN THE WEEKEND/EARLY NEXT WEEK AS A WEAK COLD FRONT SLIPS THROUGH. WEDNESDAY NIGHT...GFS80 A BIT SLOWER VERSUS THE NAM WITH THE WEAK COLD FRONT PASSAGE PLACING THE FRONT INTO THE SAGINAW VALLEY BY EVENING WHILE THE NAM PLACES THE FRONT INTO SE MICHIGAN BY THAT TIME. THIS MAY BE INCONSEQUENTIAL HOWEVER...AS LOW LEVEL CONVERGENCE WITH THE FRONT LOOKS LACKLUSTER ANYWAY AND THE DEEPER MOISTURE AXIS STILL LAGS BACK BEHIND. INSTEAD...BOTH SOLUTIONS DEVELOP A FAIRLY RESPECTABLE BAND OF 850-700MB FRONTOGENESIS WELL BEHIND THE FRONT STRETCHING FROM NRN MICHIGAN INTO CANADA AND AN ASSOCIATED BAND OF Q-VECTOR CONVERGENCE AND THE 850 MB FRONT SLIPPING THROUGH NRN LOWER MICHIGAN DURING THE EVENING HOURS. GFS IS FAIRLY AGGRESSIVE IN DEVELOPING POST FRONTAL PRECIP ACROSS NRN MICHIGAN LATE IN THE AFTERNOON AND INTO THE EVENING. DID CONSIDER EXTENDING POPS OVER A GREATER PORTION OF NRN LOWER MICHIGAN FOR THE EVENING BUT AFTER COLLABORATION WITH GRR/DTX HAVE KEPT THE CHANCE JUST ALONG AND SOUTH OF M-55 FOR NOW WHERE THE BEST LINGERING INSTABILITY WILL RESIDE. HOWEVER...MIDNIGHT SHIFT WILL WANT TO SCRUTINIZE THIS A BIT CLOSER. THURSDAY AND FRIDAY...UPPER RIDGE AXIS FORECAST TO INCH INTO THE UPPER MIDWEST WHILE SFC HIGH PRESSURE DOMINATES ACROSS THE STATE. THERE WAS A CONCERN FOR CONVECTION DEVELOPING ALONG AND NORTH OF A WARM FRONT LIFTING INTO THE PLAINS...WITH SOME OF THE CONVECTION WORKING E/SE INTO LOWER MICHIGAN BY EARLY FRIDAY. HOWEVER...MODEL TRENDS CONTINUE TO SUGGEST THAT BULK OF FOCUS/ACTIVITY WILL REMAIN WELL OFF TO THE WEST WHILE HIGH PRESSURE REMAINS DOMINANT. SO...WILL CONTINUE WITH A DRY FORECAST. SATURDAY THROUGH TUESDAY...SHARP UPPER RIDGE DEVELOPS ACROSS THE WESTERN GREAT LAKES STARTING SATURDAY AND REMAINS IN PLACE THROUGH AT LEAST EARLY NEXT WEEK. THUS...ANTICIPATE ANOTHER PERIOD OF WARMER TEMPERATURES WITH DAYTIME READINGS REACHING THE MID 70S TO LOWER 80S (NEARLY 10 DEGREES ABOVE NORMAL FOR EARLY SEP). DRY WEATHER TO START...BUT QUESTIONS ARISE OVER PRECIP CHANCES LATE IN THE WEEKEND AND EARLY NEXT WEEK AS A WEAK COLD FRONT TRIES TO SLIP SOUTH THROUGH THE STATE AND INTO THE UPPER RIDGE. GFS/ECMWF DISAGREE OVER JUST HOW FAR SOUTHWARD THIS FRONT WILL ADVANCE WITH THE ECMWF A LITTLE FLATTER WITH THE RIDGE AND FURTHER SOUTH WITH THE FRONT. SOME QUESTION AS TO WHETHER WE GET ANY PRECIP AT ALL CONSIDERING THE STRENGTH OF THE UPPER RIDGE. BUT WITH COLLABORATION WITH MQT/GRB WILL INTRODUCE A LOW CHANCE FOR PRECIP SUN NIGHT INTO MONDAY AS THIS FRONT SLIPS SOUTH. DEPENDING ON JUST WHERE THE FRONT ENDS UP...ONE CAN ARGUE TO ALSO ADD POPS THROUGH AT LEAST MONDAY NIGHT. BUT NOT WILLING TO DO SO FOR SUCH A WEAK UNCERTAIN SYSTEM. ADAM && .APX...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 425 PM EDT TUE SEP 6 2005 .DISCUSSION... CURRENTLY ACROSS UPR LAKES REGION BAND OF DEEP MOISTURE AND Q-VECTOR CONVERGENCE ASSOCIATED WITH SHORTWAVE LOBE IS PUSHING INTO E HALF OF CWA. REGIONAL RADAR LOOP SHOWS ONLY A FEW SHOWERS OVR E LAKE SUPERIOR AND OVR FAR E UPR MI. DEEPER MOISTURE HAS OUTRUN THE PRIMARY FRONT FM NCNTRL ONTARIO TO VCNTY KDLH AND BACK TOWARD KMSP. EARLY AFTN TAMDAR SOUNDINGS DEPICTED A QUITE DRY MID LEVEL AIR BACK INTO MN/N WI. EARLIER SPC DAY 1 OUTLOOK FEATURED THIS AREA FOR POSSIBLE TSRA DEVELOPMENT AS CAPES ARE BTWN 1500-2000 J/KG AND 0-6KM SHEAR IS MARGINAL 30-35KT. ALTHOUGH SFC DEWPOINTS ARE IN THE LWR 60S THUS FAR IT SEEMS LIKE DEEP DRYING/SUBSIDENCE JUST ABOVE THIS SHALLOW MOISTURE LAYER IS LIMITING ANY CONVECTION FM DEVELOPING OVR NW WI (LATEST DAY 1 HAS REMOVED THE SLIGHT RISK). JUST WITHIN LAST FEW MINUTES A FEW CELLS ARE TRYING TO DEVELOP OVR ALGER/DELTA COUNTIES ON BACK EDGE OF EXITING DEEPER MOISTURE. KEPT A 20 POP IN THIS EVENING ALONG THE FRONT. LATER TONIGHT POCKET OF MID LEVEL MOISTURE ALONG WITH STEEPENING LAPSE RATES PER RUC OVR SW MN MAY TRY TO LIFT NE ALONG THE BOUNDARY HELPED ALONG BY INCRESING DIVERGENCE FM H3 JET OVR S ONTARIO/LK SUPERIOR. KEPT SLIGHTLY HIGHER POPS OVERNIGHT MAINLY FM MNM TO ESC AND TO ISQ. FRONT WILL BE OVR FAR S CNTRL CWA BY 12Z WED THEN PUSH TO THE S THROUGH THE MORNING. AS THE WAVE OF DEEPER MOISTURE/Q-VECTOR CONVERGENCE RIDE ALONG THE FRONT KEPT A 20 POP IN OVR FAR S THROUGH THE MORNING...AND INTO EARLY AFTN FOR FAR S MENOMINEE COUNTY. DEEP DRYING AND SUBSIDENCE SWEEP ACROSS REST OF CWA WED AFTN AND SKIES SHOULD BECOME MOSTLY SUNNY. H85 TEMPS FM +8C N TO +12C SOUTH SUGGEST TEMPS IN THE UPR 60S ALONG KEWEENAW TO MID 70S INLAND AND ALONG LK MI. WED NIGHT LOOKS CHILLY AS SFC HIGH FIRMLY SLIDES OVER THE UPR LAKES. WITH GFS/NAM WINDS THROUGH H85 VERY LIGHT AND SOME HINT OF PWAT MINIMUM OVER UPR MI...THINK THAT LOWS WELL BELOW GUIDANCE ARE GOOD. PREV FCST HAD SOME UPR 30S INLAND AND THAT SEEMS GOOD. TEMPS ON THU WILL LIKELY BE A BIT COOLER THAN WED AS THERMAL TROUGH IS OVERHEAD. 00Z GFS DID REMAIN INSISTENT ON BRUSHING W AND S CWA WITH SOME QPF BTWN 18Z THU AND 06Z FRI. THE 12Z RUN FINALLY BEGAN TO BACK AWAY SIMILAR TO NAM AND CANADIAN. THE TREND WITHIN LAST COUPLE DAYS WAS FOR HIGHER PRESSURES OVER THE REGION AS ECMWF FIRST SHOWED. THE WARM FRONT SHOWN BY MODELS A COUPLE DAYS AGO IS ALL BUT GONE SO ANY QPF WOULD BE ASSOCIATED WITH CONVECTION THAT EMERGES FM DAKOTAS AND W MN ON THU AFTN AND TRIES TO ROLL EAST. THINK DRY AIRMASS AND HIGH PRES RIDGE OVR E CWA WILL KEEP MOST PCPN OUT OF CWA THU AFTN THROUGH FRI NIGHT. AFTER COORD WITH GRB AND FACT THAT 12Z RUNS OF GFS/NAM/CANADIAN SHOW POSSIBLE MCS PASSING TO THE SOUTH OF UPR MI KEPT ANY POPS OUT OF CWA THU NIGHT-FRI. AND SINCE THE PRIMARY WARM AIR ADVECTION AND FORCING FOR PCPN WILL BE FROM THE N PLAINS INTO CNTRL CANADA LATER FRI INTO SAT REMOVED ALL POPS DURING THAT TIME. EXTENDED (SAT THROUGH TUE)...H5 HEIGHTS RISE IN EARNEST ON SAT WITH 588DAM HEIGHTS POKING INTO THE UPR LAKES SAT AFTN. H85 TEMPS RISING INTO UPR TEENS SUPPORT MAX TEMPS IN THE MID 80S. UPR LAKES REMAIN ON E EDGE OF THE H5 RIDGE SUN-MON. UPR LEVEL CONFLUENCE DEVELOPING OVR ONTARIO WILL HELP HIGH PRES AREA TO SPRAWL TOWARD N FRINGES OF UPR LAKES SUN AFTN. GFS/ECMWF BOTH SHOW HIGHER PRESSURES TO THE NORTH AND BOTH SHOW A WEAK COLD FRONT ON LEADING EDGE OF COOLER AIR WILL PUSH INTO CWA SUN PM. STILL EXPECT VERY WARM TEMPS AHEAD OF THE FRONT ON SUN AFTN. COOLEST DAY WILL LIKELY BE ON MON AS LIGHT ONSHORE FLOW AFFECTS AT LEAST LK SUPERIOR ZONES AS HIGH SLIDES INTO FAR E ONTARIO INTO QUEBEC. AS LONG AS THIS FRONT IS IN VCNTY CANNOT RULE OUT SHRA/TS ON MON. DROPPED POPS TO SLIGHT CHANCE MON NIGHT AS GFS/ECMWF AND GFS ENSEMBLES INDICATE FRONT SLIDES TO THE SOUTH OF CWA. ATTN THEN TURNS TO DEVELOPING TROUGH OVR N PLAINS LATE MON NIGHT INTO TUE. WARM FRONT ASSOCIATED WITH THIS LOW PRES AREA (PERHAPS THE COLD FRONT THAT JUST PUSHED THROUGH) WILL MOVE BACK INTO UPR LAKES TUE AFTN PROVIDING A FOCUS FOR ADDITIONAL SHRA/TS CHANCES. COORD WITH APX/GRB/DLH...THANKS. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ JLA mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1113 AM EDT TUE SEP 6 2005 .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST UPDATE IS THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING OVER THE CWA. WATER VAPOR IMAGERY AND RUC/ETA SHOWING A CLOSED LOW OVER CENTRAL MANITOBA AND A BROAD HIGH OVER NEW YORK STATE. ANOTHER HIGH IS OVER NORTH CENTRAL TEXAS. A WEAK SHORTWAVE MOVING THROUGH THE BASE OF THE MANITOBA LOW IS OVER MINNESOTA WITH ANOTHER OVER NORTHERN LAKE MICHIGAN. SURFACE ANALYSIS INSIST THAT A COLD FRONT STRETCHES FROM A LOW OVER NORTHWEST ONTARIO THROUGH MINNESOTA TO A LOW IN SOUTHEAST COLORADO. A LARGE HIGH BLANKETS THE NORTHEAST STATES. SCATTERED SHOWERS HAVE BEEN FIRING IN THE AREA OF ISENTROPIC ASCENT AHEAD OF THE COLD FRONT OVER EASTERN MINNESOTA...NORTHERN WISCONSIN...AND OVER WEST END OF THE FORECAST AREA. ETA12/RUC INDICATE TWO WEAK SHORTWAVES AHEAD OF THE FRONT. THE FIRST OVER NORTHERN LAKE MICHIGAN WILL DEEPEN THIS AFTERNOON AND WILL BE DIVERT NORTHEAST AS IT RUNS UP AGAINST THE EAST COAST HIGH. THE WEAK SHORTWAVE OVER MINNESOTA WILL MERGE WITH THE SHORTWAVE OVER NORTHERN LAKE MICHIGAN THIS AFTERNOON. THE UPPER LEVEL JET ALSO INDICATES THE STRONGEST DIVERGENCE WILL BE OVER THE EASTERN U.P. THIS AFTERNOON. A BAND OF LOW LEVEL MOISTURE WILL LIKEWISE MERGE OVER THE EAST END OF THE CWA THIS AFTERNOON. MODELS INDICATE SBCAPE OF AROUND 2000J/KG OVER THE EASTERN U.P. THIS AFTERNOON. K-INDEX OF AROUND 35...AND LIFTED INDEX OF AROUND -5. THUS PLAN TO UP THE POPS FOR PARTS OF EASTERN U.P. THIS AFTERNOON. CONDITIONS LOOK FAVORABLE FOR A LITTLE BETTER CHANCE OVER THE EASTERN U.P. THIS AFTERNOON. TEMPERATURES LOOK REASONABLE SO FAR. WILL NEED TO TWEAK THE WORDING ON WINDS A BIT. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 945 PM CDT TUE SEP 6 2005 .DISCUSSION... SHOWERS IN SOUTHEAST NEBRASKA ARE SLOWLY ADVANCING TOWARD THE NORTHWEST TIP OF MISSOURI. METARS FROM CONCORDIA AND BEATRICE SUGGEST THAT CLOUD BASES ARE QUITE HIGH (8000 TO 12000 FT) AND THE SOUNDING FROM TOPEKA CONFIRMS THAT THE LOW LEVELS OF THE ATMOSPHERIC COLUMN ARE DRY. ONE MUST LOOK TO 700MB TO FIND THE SOURCE OF LIFT FOR THE SHOWERS IN SOUTHEAST NEBRASKA. PROFILERS AND RUC ANALYSIS INDICATE MODEST THETA-E ADVECTION FROM HASTINGS TO FALLS CITY DIMINISHING SUBSTANTIALLY OVER NORTHWEST MISSOURI. UPGLIDE OVER THE SAME AREA CAN BE INFERRED ON THE RUC 310 THETA SURFACE. LIFT IS NOT FORECAST BY THE RUC TO MOVE EAST MUCH OVERNIGHT SO I HAVE ONLY INCLUDED LOW CHANCES OF SHOWERS IN DONIPHAN, HOLT AND ATCHISON COUNTIES THROUGH SUNRISE. CHANCES FOR THUNDER DO NOT LOOK GOOD SINCE MID LEVEL LAPSE RATES ARE POOR (BARELY MOIST ADIABATIC). KOCH .PREV DISCUSSION... 334 PM... FORECAST CONCERN IS FOR RAIN CHANCES THROUGH THE NEXT SEVERAL DAYS. WATCHING TWO MAIN AREAS. SCATTERED CONVECTION PERSISTED ACROSS CENTRAL KANSAS IN AREA OF LIFT WITHIN THE SUBTROPICAL MOISTURE PLUME. THIS HAS EVEN GENERATED A WEAK MCV ACROSS NORTHERN KANSAS. WITH THE MCV PUSHING CLOSE TO EXTREME NORTHWEST MISSOURI...HAVE ADDED SLIGHT CHANCE POPS TO THAT AREA FOR THIS EVENING. DO NOT THINK THE SCATTERED PRECIP OVER CENTRAL KANSAS WILL HAVE ENOUGH ENERGY TO MAKE IT TO THE MISSOURI-KANSAS BORDER AS WINDS ACROSS WESTERN KANSAS HAVE BEGUN TO BACK. CONVECTION FROM LAST NIGHT MANAGED TO PUSH A WEAK OUTFLOW BOUNDARY INTO EXTREME NORTHERN MISSOURI THIS MORNING. THAT BOUNDARY HAS SINCE WASHED OUT. HOWEVER THE WEAK COLD FRONT IS PUSHING A LITTLE CLOSER...ACROSS NORTHERN NEBRASKA INTO NORTHWEST IOWA. CONVECTION HAS BEEN FIRING ALONG THIS FRONT ACROSS NORTHEAST NEBRASKA. THIS IS THE SECOND AREA TO WATCH. HAVE HELD ON TO THE SLIGHT CHANCE POPS ACROSS NORTHERN MISSOURI AS PERIODS OF ISENTROPIC LIFT ARE GENERATED ALONG AND SOUTH OF THE FRONT...WHICH MAY JUST EDGE INTO THE AREA. BOTH THE GFS AND NAM SUGGEST HIGH RH AND PERIODS OF ISENTROPIC LIFT ACROSS NORTHERN MISSOURI BEGINNING WEDNESDAY...CONTINUING INTO THURSDAY. HAVE MAINTAINED LOW CHANCE POPS FOR NORTHERN MISSOURI DURING THAT TIME. HAVE NOT GONE HIGHER WITH THE ACTUAL LOCATION OF THE BOUNDARY STILL IN QUESTION. CURRENT TEMP FORECAST REMAINS ON TRACK WITH COOLER TEMPS ACROSS THE NORTH AND HIGHS IN THE UPPER 80S TO AROUND 90 IN THE SOUTH. IF RAIN SETS UP ACROSS NORTHERN MISSOURI...LATER SHIFTS WILL NEED TO LOWER HIGHS IN THAT AREA BY SEVERAL CATEGORIES. UPPER RIDGING BEGINS TO AMPLIFY AND SHIFT EAST BY THE WEEKEND AS TROUGHING INCREASES OVER THE WEST. THIS WILL LEAVE THE FORECAST AREA WITHIN SOUTHWEST FLOW ALOFT. FEW CHANGES MADE TO THE EXTENDED FORECAST...OTHER THAN BUMPING TEMPERATURES UP A DEGREE OR TWO HERE AND THERE. THE NEXT FRONT TO OUR WEST LOOKS LIKE IT WILL HOLD OFF REACHING THE AREA UNTIL AFTER THE 7 DAY FORECAST...SO KEPT THE FORECAST FROM FRIDAY THROUGH TUESDAY DRY. NRR/STOFLET && 232 AM TUE... THE FIRST FEW DAYS OF THE FORECAST FEATURE A FLATTENING UPPER LEVEL RIDGE WITH A SURFACE BOUNDARY HOVERING JUST NORTH OF OUR CWA. THE CHALLENGE IS TO TIME THIS BOUNDARY...ADJUSTING POPS AS NECESSARY. THERE ARE A FEW WAVES THAT THE SHORT RANGE MODELS FORECAST TO MOVE THROUGH WHICH MAY BE ENOUGH TO PUSH THE BOUNDARY THROUGH. ALTHOUGH THE GFS LOOKS MORE LIKE CONVECTIVE FEEDBACK THAN ANYTHING. WITHOUT ANY STRONG FEATURE TO FOCUS ON...AND BOUNDARY CONVERGENCE LOOKING WEAK...HAVE NOT RAISED POPS ANY FROM PREVIOUS FORECAST. AS FAR AS TIMING...BEST FORCING AND MOISTURE CONVERGENCE LOOKS TO STAY JUST WEST OF US OVERNIGHT TONIGHT...SO HAVE REMOVED POPS FROM THE OVERNIGHT PD AND PUSHED INTO WEDNESDAY. WILL KEEP BOUNDARY POSITION IN THE NORTH WED/WED NIGHT AND CONTINUE PREVIOUS FORECAST THOUGHT OF MOVING IT THROUGH/WASHING IT OUT/ ON THURS. MAINLY A PERSISTENCE FORECAST FOR TEMPS...HOWEVER HAVE LOWERED TEMPS SLIGHTLY IN NORTHERN CWA FOR CLOUD/RAIN POTENTIAL. LVK && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. $$ WFO EAX mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 1000 AM EDT TUE SEP 6 2005 .SHORT TERM (TODAY)...STRONG SFC HI PRES OVER THE MID-ATLC CONTINUES TO CONTROL THE WX ACROSS NC. PREVAILING NE FLOW IS PRODUCING SHOWERS OVER THE NEAR SHORE WATERS BUT NONE OCCURRING OVER LAND. FORECAST SOUNDINGS FROM BOTH THE NAM AND GFS INDICATE PLENTY OF LOW LEVEL MOIST IN THE DEEP EASTERLY FLOW ACROSS THE REGION. THIS WILL LEAD TO NUMEROUS STRATOCUMULUS CLOUD STREETS WITH HEATING. WHILE THE BULK OF ANY SHOWER ACTIVITY WILL REMAIN OFFSHORE...THERE IS ENOUGH MOIST AND LATENT INSTAB FOR A LOW THREAT OF A FEW SHOWERS ALONG THE IMMEDIATE COAST THIS AFTERNOON. THIS IS INDICATED IN ALL THE OPERATIONAL MODELS INCLUDING THE RUC40. ONSHORE FLOW AND CLOUDS WILL HELP TO KEEP MINIMUM TEMPS A LITTLE BELOW NORMAL TODAY. DECENT P-GRAD BETWEEN HIGH PRES NORTH AND A SERIES OF LOWS IN THE TROPICS WILL PRODUCE BREEZY/WINDY CONDITIONS INLAND/COAST. THE CURRENT FORECAST IS IN GOOD SHAPE AND NO CHANGES PLANNED. && .AVIATION...VFR CONDITIONS WILL EXIST TODAY. SOME SCT-BKN AFTERNOON CU WILL DEVELOP BY THIS AFTERNOON. && .MARINE....SMALL CRAFT ADVISORY CONTINUES FOR ALL COASTAL WATERS TODAY. HAVE INCREASED WINDS OVER THE SOUNDS TO REFLECT CURRENT TRENDS AND BUMPED WAVES TO 2-3 FT. HAVE DECIDED TO UPGRADE THE SCEC THAT WAS IN EFFECT FOR THE SOUNDS TO A SCA UNTIL 00Z AS WINDS WILL REMAIN IN THE 20-25 KT RANGE. SEAS 11-12 FT AT DIAMOND WITH 10-11 SECOND PERIOD. WILL RETAIN HIGH SURF ADVISORY FOR AREAS NORTH OF HATTERAS UNTIL WEDNESDAY MORNING. .RIP CURRENTS...STRONG NORTHEAST FLOW COMBINED WITH LONG PERIOD SWELL WILL RESULT IN A HIGH THREAT OF RIP CURRENTS ALL COASTAL AREAS TODAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...HIGH SURF ADVISORY NCZ103 UNTIL 8 AM WEDNESDAY. MARINE...SMALL CRAFT ADVISORY FOR AMZ152-154-156-158 UNTIL 2 PM THURSDAY. ...SMALL CRAFT ADVISORY FOR AMZ150 UNTIL 2 AM THURSDAY. ...SMALL CRAFT ADVISORY FOR AMZ130-135 UNTIL 8 PM TUESDAY. && $$ JME/JW nc AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE GRAND FORKS ND 815 PM CDT TUE SEP 6 2005 .UPDATE... JMS JUST CAME IN WITH SOME -RA...SO ECHOES ARE HITTING THE GROUND. AMOUNTS WILL BE VERY LIGHT THOUGH...LIKELY AROUND 0.01. WITH DEWPOINTS IN SOUTHERN 1/3 OF AREA AROUND 50...WILL MENTION SOME ISOLATED SHOWERS IN SOUTH UNTIL AROUND 08Z...WITH CLEARING THEREAFTER. .UPDATE... MAIN CHALLENGE OVERNIGHT WILL BE CLOUD TRENDS AND TEMPS. MID LEVEL CLOUDS CONTINUE ALONG A BISMARCK TO JMS LINE THIS EVENING...WITHIN 850-700MB FRONTOGENESIS AND SOME WEAK LIFT HERE. MAIN MOISTURE IS BETWEEN 600 AND 500MB...AND CLOUD BASES FROM BISMARCK NEVER WENT BROKEN AS SOME RADAR ECHOES WENT OVER THEM. LOW LEVELS WILL DRY OUT SIGNIFICANTLY OVERNIGHT...WITH DEWPOINTS FALLING INTO THE UPPER 30S UPSTREAM OF THE FORECAST AREA. SFC HIGH PRESSURE WILL SETTLE OVER REGION LATER TONIGHT...AND EXPECT SKIES TO CLEAR IN ALL AREAS BY LATE TONIGHT. SOUTHERN AREAS WILL KEEP CLOUDS THE LONGEST...AND LOWS WILL BE WARMER HERE. FURTHER NORTH THOUGH...SKIES ARE CLEAR ALREADY AND ONCE HIGH BUILDS IN...EXPECT TEMPS TO FALL. LOWS LAST NIGHT NEAR THIS HIGH IN CANADA WERE IN THE UPPER 30S...SO SOME COOL READINGS POSSIBLE BY MORNING. EXPECT A FEW AREAS IN NORTHWEST TO BE IN THE LOWER 40S OR EVEN NEAR 40 IN SOME LOCALIZED SPOTS. READINGS TO THE SOUTH WILL BE WARMER...PROBABLY IN THE UPPER 40S. WILL NEED TO ADJUST LOWS DOWN SOME OVERNIGHT. DON/T EXPECT ANY PRECIPITATION FROM CURRENT VIRGA ECHOES ON RADAR. CAN/T RULE OUT AN ISOLATED SPRINKLE IN THE SOUTH...BUT NOT WORTH A MENTION IN GRIDS...BUT WILL MONITOR FOR POTENTIAL ISOLATED SHOWER THIS EVENING. WILL SEND UPDATED GRIDS/TEXT PRODUCTS BY 915 PM. && .PREV DISCUSSION... (ISSUED 255 PM CDT TUE SEP 6 2005) SHORT TERM...FORECAST CHALLENGE TO BE TEMPERATURES AND THEN PRECIP CHANCES THU MORNING THRU FRI. 12Z GFS/NAM INITIALIZED WELL AND IN GENERAL AGREEMENT. WILL USE COMPROMISE. CLOUD COVER WITH BASES AROUND 10KFT CURRENTLY EXTENDS FROM W CENTRAL ND TO E CENTRAL ND. WEAK RETURNS ALSO EVIDENT ON RADAR IMAGERY. THIS ASSOCIATED WITH 850MB-700MB BAROCLINIC ZONE WHICH EXTENDS THROUGH THE AREA...WITH WEAK SHORTWAVES RIDING IN FAST UPPER LEVEL FLOW. 500MB SHORTWAVE LOCATED NORTH OF MINNESOTA TO CONTINUE SLOW NE PROPAGATION. THIS TO KEEP FORECAST AREA (FA) IN NW FLOW WHICH TRANSLATES BAROCLINIC ZONE TO SOUTHERN FA. AS A RESULT...18Z RUC SHOWS MID-LEVEL FRONTOGENESIS AND INCREASED 700MB-500MB RH. WITH DRY LOW LEVEL RH EXPECT ONLY VIRGA...WHICH IS CURRENTLY OBSERVED. THUS...MOSTLY CLOUD SKIES ACROSS S FA WILL BE SUFFICIENT. SKIES WILL CLEAR AFTER MIDNIGHT ALLOWING TEMPS TO DROP TO NEAR DEW POINT VALUES. SFC HIGH PRESSURE/LOW LEVEL RIDGE TO PROPAGATE ACROSS THE REGION THROUGH WEDNESDAY. THIS WILL KEEP THE AREA DRY AND TEMPS NEAR NORMAL. AS THIS FEATURE SHIFTS EAST RETURN FLOW WILL ALLOW MOISTURE AND HIGHER TEMPS TO RETURN FOR THU-FRI. WITH WAVES IS FAST UPPER ZONAL FLOW...INSTABILITY IN PLACE...AND WARM AIR ADVECTION REGIME WILL KEEP LOW POPS LATE WED NIGHT-FRI. MODELS HINTING AT A SCENARIO WHERE ONE COMPLEX MOVES THROUGH AREA THU MORNING...AND THEN ANOTHER THU NIGHT-FRI MORNING WITH BEST CHANCES ACROSS SOUTHERN FA (BEST INSTABILITY AND PROXIMITY TO LOW LEVEL JET)...BUT THIS ALL UNCERTAIN. THE LACK OF ANY SHARP SFC BOUNDRY WILL MAKE WIDESPREAD CONVECTION DIFFICULT. HOWEVER...ISOLD CONVECTION IS POSSIBLE DURING THU-FRI PERIOD. LONG TERM...SAT THROUGH TUE...MODELS ARE IN PRETTY GOOD AGREEMENT WITH DIGGING 500MB TROF IN W U.S. AS 500MB RIDGE REMAINS OVER N PLAINS. SURFACE HIGH KEEPS AREA DRY FOR SAT AND SAT NIGHT. THEN... THE NEXT LOW PRESSURE SYSTEM MOVES OUT INTO THE PLAINS...BRINGING A CHANCE FOR THUNDERSTORMS TO THE AREA SUN AND MON. AS FAR AS TEMPERATURES...EXPECT TO REMAIN NEAR TO ABOVE NORMAL. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ DK nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 806 PM CDT TUE SEP 6 2005 .UPDATE... MAIN CHALLENGE OVERNIGHT WILL BE CLOUD TRENDS AND TEMPS. MID LEVEL CLOUDS CONTINUE ALONG A BISMARCK TO JMS LINE THIS EVENING...WITHIN 850-700MB FRONTOGENESIS AND SOME WEAK LIFT HERE. MAIN MOISTURE IS BETWEEN 600 AND 500MB...AND CLOUD BASES FROM BISMARCK NEVER WENT BROKEN AS SOME RADAR ECHOES WENT OVER THEM. LOW LEVELS WILL DRY OUT SIGNIFICANTLY OVERNIGHT...WITH DEWPOINTS FALLING INTO THE UPPER 30S UPSTREAM OF THE FORECAST AREA. SFC HIGH PRESSURE WILL SETTLE OVER REGION LATER TONIGHT...AND EXPECT SKIES TO CLEAR IN ALL AREAS BY LATE TONIGHT. SOUTHERN AREAS WILL KEEP CLOUDS THE LONGEST...AND LOWS WILL BE WARMER HERE. FURTHER NORTH THOUGH...SKIES ARE CLEAR ALREADY AND ONCE HIGH BUILDS IN...EXPECT TEMPS TO FALL. LOWS LAST NIGHT NEAR THIS HIGH IN CANADA WERE IN THE UPPER 30S...SO SOME COOL READINGS POSSIBLE BY MORNING. EXPECT A FEW AREAS IN NORTHWEST TO BE IN THE LOWER 40S OR EVEN NEAR 40 IN SOME LOCALIZED SPOTS. READINGS TO THE SOUTH WILL BE WARMER...PROBABLY IN THE UPPER 40S. WILL NEED TO ADJUST LOWS DOWN SOME OVERNIGHT. DON/T EXPECT ANY PRECIPITATION FROM CURRENT VIRGA ECHOES ON RADAR. CAN/T RULE OUT AN ISOLATED SPRINKLE IN THE SOUTH...BUT NOT WORTH A MENTION IN GRIDS...BUT WILL MONITOR FOR POTENTIAL ISOLATED SHOWER THIS EVENING. WILL SEND UPDATED GRIDS/TEXT PRODUCTS BY 915 PM. && .PREV DISCUSSION... (ISSUED 255 PM CDT TUE SEP 6 2005) SHORT TERM...FORECAST CHALLENGE TO BE TEMPERATURES AND THEN PRECIP CHANCES THU MORNING THRU FRI. 12Z GFS/NAM INITIALIZED WELL AND IN GENERAL AGREEMENT. WILL USE COMPROMISE. CLOUD COVER WITH BASES AROUND 10KFT CURRENTLY EXTENDS FROM W CENTRAL ND TO E CENTRAL ND. WEAK RETURNS ALSO EVIDENT ON RADAR IMAGERY. THIS ASSOCIATED WITH 850MB-700MB BAROCLINIC ZONE WHICH EXTENDS THROUGH THE AREA...WITH WEAK SHORTWAVES RIDING IN FAST UPPER LEVEL FLOW. 500MB SHORTWAVE LOCATED NORTH OF MINNESOTA TO CONTINUE SLOW NE PROPAGATION. THIS TO KEEP FORECAST AREA (FA) IN NW FLOW WHICH TRANSLATES BAROCLINIC ZONE TO SOUTHERN FA. AS A RESULT...18Z RUC SHOWS MID-LEVEL FRONTOGENESIS AND INCREASED 700MB-500MB RH. WITH DRY LOW LEVEL RH EXPECT ONLY VIRGA...WHICH IS CURRENTLY OBSERVED. THUS...MOSTLY CLOUD SKIES ACROSS S FA WILL BE SUFFICIENT. SKIES WILL CLEAR AFTER MIDNIGHT ALLOWING TEMPS TO DROP TO NEAR DEW POINT VALUES. SFC HIGH PRESSURE/LOW LEVEL RIDGE TO PROPAGATE ACROSS THE REGION THROUGH WEDNESDAY. THIS WILL KEEP THE AREA DRY AND TEMPS NEAR NORMAL. AS THIS FEATURE SHIFTS EAST RETURN FLOW WILL ALLOW MOISTURE AND HIGHER TEMPS TO RETURN FOR THU-FRI. WITH WAVES IS FAST UPPER ZONAL FLOW...INSTABILITY IN PLACE...AND WARM AIR ADVECTION REGIME WILL KEEP LOW POPS LATE WED NIGHT-FRI. MODELS HINTING AT A SCENARIO WHERE ONE COMPLEX MOVES THROUGH AREA THU MORNING...AND THEN ANOTHER THU NIGHT-FRI MORNING WITH BEST CHANCES ACROSS SOUTHERN FA (BEST INSTABILITY AND PROXIMITY TO LOW LEVEL JET)...BUT THIS ALL UNCERTAIN. THE LACK OF ANY SHARP SFC BOUNDRY WILL MAKE WIDESPREAD CONVECTION DIFFICULT. HOWEVER...ISOLD CONVECTION IS POSSIBLE DURING THU-FRI PERIOD. LONG TERM...SAT THROUGH TUE...MODELS ARE IN PRETTY GOOD AGREEMENT WITH DIGGING 500MB TROF IN W U.S. AS 500MB RIDGE REMAINS OVER N PLAINS. SURFACE HIGH KEEPS AREA DRY FOR SAT AND SAT NIGHT. THEN... THE NEXT LOW PRESSURE SYSTEM MOVES OUT INTO THE PLAINS...BRINGING A CHANCE FOR THUNDERSTORMS TO THE AREA SUN AND MON. AS FAR AS TEMPERATURES...EXPECT TO REMAIN NEAR TO ABOVE NORMAL. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ DK nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 255 PM CDT TUE SEP 6 2005 .SHORT TERM...FORECAST CHALLENGE TO BE TEMPERATURES AND THEN PRECIP CHANCES THU MORNING THRU FRI. 12Z GFS/NAM INITIALIZED WELL AND IN GENERAL AGREEMENT. WILL USE COMPROMISE. CLOUD COVER WITH BASES AROUND 10KFT CURRENTLY EXTENDS FROM W CENTRAL ND TO E CENTRAL ND. WEAK RETURNS ALSO EVIDENT ON RADAR IMAGERY. THIS ASSOCIATED WITH 850MB-700MB BAROCLINIC ZONE WHICH EXTENDS THROUGH THE AREA...WITH WEAK SHORTWAVES RIDING IN FAST UPPER LEVEL FLOW. 500MB SHORTWAVE LOCATED NORTH OF MINNESOTA TO CONTINUE SLOW NE PROPAGATION. THIS TO KEEP FORECAST AREA (FA) IN NW FLOW WHICH TRANSLATES BAROCLINIC ZONE TO SOUTHERN FA. AS A RESULT...18Z RUC SHOWS MID-LEVEL FRONTOGENESIS AND INCREASED 700MB-500MB RH. WITH DRY LOW LEVEL RH EXPECT ONLY VIRGA...WHICH IS CURRENTLY OBSERVED. THUS...MOSTLY CLOUD SKIES ACROSS S FA WILL BE SUFFICIENT. SKIES WILL CLEAR AFTER MIDNIGHT ALLOWING TEMPS TO DROP TO NEAR DEW POINT VALUES. SFC HIGH PRESSURE/LOW LEVEL RIDGE TO PROPAGATE ACROSS THE REGION THROUGH WEDNESDAY. THIS WILL KEEP THE AREA DRY AND TEMPS NEAR NORMAL. AS THIS FEATURE SHIFTS EAST RETURN FLOW WILL ALLOW MOISTURE AND HIGHER TEMPS TO RETURN FOR THU-FRI. WITH WAVES IS FAST UPPER ZONAL FLOW...INSTABILITY IN PLACE...AND WARM AIR ADVECTION REGIME WILL KEEP LOW POPS LATE WED NIGHT-FRI. MODELS HINTING AT A SCENARIO WHERE ONE COMPLEX MOVES THROUGH AREA THU MORNING...AND THEN ANOTHER THU NIGHT-FRI MORNING WITH BEST CHANCES ACROSS SOUTHERN FA (BEST INSTABILITY AND PROXIMITY TO LOW LEVEL JET)...BUT THIS ALL UNCERTAIN. THE LACK OF ANY SHARP SFC BOUNDRY WILL MAKE WIDESPREAD CONVECTION DIFFICULT. HOWEVER...ISOLD CONVECTION IS POSSIBLE DURING THU-FRI PERIOD. .LONG TERM...SAT THROUGH TUE...MODELS ARE IN PRETTY GOOD AGREEMENT WITH DIGGING 500MB TROF IN W U.S. AS 500MB RIDGE REMAINS OVER N PLAINS. SURFACE HIGH KEEPS AREA DRY FOR SAT AND SAT NIGHT. THEN... THE NEXT LOW PRESSURE SYSTEM MOVES OUT INTO THE PLAINS...BRINGING A CHANCE FOR THUNDERSTORMS TO THE AREA SUN AND MON. AS FAR AS TEMPERATURES...EXPECT TO REMAIN NEAR TO ABOVE NORMAL. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ TG/NG nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 1023 AM CDT TUE SEP 6 2005 .UPDATE...500MB SHORTWAVE NOW NORTH OF MINNESOTA PLACING FORECAST AREA (FA) IN COLD AIR ADVECTION REGIME. THIS WILL KEEP SKIES MOSTLY CLEAR THROUGH THE MORNING AND EARLY AFTERNOON HOURS AS DRIER AIR WORKS IN. SATELLITE IMAGERY SHOWS BAND OF MID TO HIGH CLOUDS EXTENDING FROM E MONTANA THROUGH W ND. THESE MOST LIKELY ASSOCIATED WITH BAND OF 700MB FRONTOGENESIS SHOWN BY 12Z RUC. WATER VAPOR IMAGERY ALSO INDICATING WEAK WAVE IN FAST 500MB FLOW. RADAR IMAGERY SHOWING WEAK RETURNS...BUT WITH DRY LOW-LEVEL AIR EXPECT MOSTLY VIRGA. AS ENTIRE PATTERN TRANSLATES EAST TODAY 700MB FRONTOGENESIS WILL AFFECT SOUTHERN FA. WILL NEED TO INCREASE CLOUD COVERAGE FOR LATE AFTERNOON/EARLY EVENING...ESPECIALLY ACROSS SOUTHERN FA. AGAIN EXPECT ONLY VIRGA IF ANYTHING. BREEZY TO WINDY CONDITIONS (ESPECIALLY ACROSS NORTHERN FA) WILL SUBSIDE DURING THE AFTERNOON AS SFC HIGH PRESSURE WORKS IN. TEMPERATURES LOOK REASONABLE. TG && .PREV DISCUSSION... (ISSUED 421 AM CDT TUE SEP 6 2005) SHORT TERM (TODAY THRU FRIDAY)... FORECAST CHALLENGE OVER THIS PERIOD WILL CONCERN PRECIP CHANCES THURSDAY MORNING INTO THE EARLY WEEKEND. THIS MORNING...THUNDERSTORMS HAVE MOVED SOUTH AND EAST INTO SOUTHERN MN AND NORTHERN IOWA ALONG A PREFRONTAL TROUGH. THE MAIN BOUNDARY JUST EAST OF HALLOCK EXTENDING SOUTHWARD EAST OF CROOKSTON THROUGH JUST WEST OF WAHPETON...HAS BEEN SLOWLY PROPAGATING EASTWARD ACROSS THE FORECAST AREA. BEHIND THE BOUNDARY MOSTLY CLEAR SKIES WITH HIGH PRESSURE BUILDING IN FROM THE WEST. EASTERN NORTH DAKOTA REMAINS MOSTLY CLEAR THIS MORNING WITH CLOUDS LINGERING OVER MOST OF NORTHWEST AND WEST CENTRAL MINNESOTA LEFT OVER FROM THE CONVECTION OVERNIGHT. NORTHWEST SURFACE FLOW WILL ALLOW SLIGHTLY COOLER AND DRY AIR INTO NORTHERN NORTH DAKOTA WHICH WILL SLOWLY WORK SOUTHEAST DURING THE DAY INTO NORTHWEST AND WEST CENTRAL MN. HIGH PRESSURE WILL REMAIN OVER THE FORECAST AREA THROUGH WEDNESDAY GIVING WAY TO THE NEXT UPPER LEVEL WAVE WEDNESDAY NIGHT. THE NEXT CHANCE FOR PRECIP COMES EARLY THURSDAY AS SHORTWAVE MOVES INTO THE NORTHERN PLAINS ON WEDNESDAY. LOW PRESSURE DEVELOPS OVER EASTERN MT...WESTERN ND AND SD WITH WARM FRONT EXTENDING EAST INTO SOUTHERN MN WHICH SHOULD ALLOW SOME CONVECTION TO DEVELOP OVER WESTERN ND WEDNESDAY NIGHT AND SPREAD EAST INTO EASTERN ND/WESTERN MN THURSDAY MORNING. SOUTHEAST RETURN FLOW ON THE BACK SIDE OF THE EASTWARD MOVING SURFACE HIGH AND INCREASING 850 MB JET SHOULD ALLOW CONVECTION TO CONTINUE INTO THURSDAY AFTERNOON ALONG THE WARM FRONT. MODELS CONTINUE TO DISAGREE WITH LOCATION OF CONVECTION AND MOVEMENT OF SURFACE BOUNDARIES. GFS SOLUTION SEEMED MORE REALISTIC AND USED FROM THIS TIME PERIOD. CHANCES FOR THUNDERSTORMS REMAIN THROUGH FRIDAY WITH VORT ENERGY MOVING NORTHEASTWARD. SOUNDINGS SUGGEST +40 KT 850 MB JET...+1400 J/KG ML CAPES AND FAVORABLE MID LEVEL LAPSE RATES. HOWEVER...CAPPING MAY BE AN ISSUE...+20 C 850 MB TEMPS...WHICH COULD LIMIT SURFACE BASED CONVECTION. VERY MINOR CHANGES TO THE FORECAST OVERALL. TWEAKED SOME OF THE WX POPS GRIDS THROUGH THE WEEKEND BUT NO MAJOR CHANGES. LONG TERM (SAT THRU TUES)... NO MAJOR CHANGES IN THE EXTENDED. LEFT FROM SAT MORNING ON DRY HOWEVER MODELS CONTINUE TO SHOW AN ACTIVE PATTERN EARLY NEXT WEEK. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ JDS nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC ISSUED BY NATIONAL WEATHER SERVICE COLUMBIA SC 1030 AM EDT TUE SEP 6 2005 .SHORT TERM (REST OF TODAY)... TEMPERATURE-DEW POINT TEMPERATURE SPREADS LATE THIS MORNING SUPPORT REMOVING MORNING FOG FROM THE FORECAST. THE MAIN PROBLEM IS THE EXTEND OF CLOUDINESS THIS AFTERNOON IN THE EAST-NORTHEAST FLOW UNDER THE INVERSION. THE LATEST RUC MAINTAINS HIGH RELATIVE HUMIDITY AROUND H85 THROUGH THIS AFTERNOON. EXPECT ENOUGH MIXING WILL PROBABLY OCCUR TO GENERALLY KEEP BREAKS IN THE CLOUDINESS SO PLAN TO KEEP THE PARTLY CLOUDY FORECAST THIS AFTERNOON. TEMPERATURES APPEAR ON TRACK. && .PREVIOUS DISCUSSION... (ISSUED 224 AM EDT TUE SEP 6 2005) SHORT TERM (TODAY THROUGH THURSDAY)... IR IMAGERY BEFORE ECLIPSE DEPICTED HIGH BASED STRATOCU DEVELOPING ONCE AGAIN IN EASTERLY 850 MB FLOW EARLY THIS MORNING. HOWEVER...NAM AND GFS BOTH FEATURE 850 MB DRYING IN THE SUBSIDENCE UNDER THE RIDGE THROUGH 12Z...SO SKY COVER SHOULD AVERAGE OUT TO PARTLY CLOUDY. CLOUDS MAY INCREASE SLIGHTLY ACROSS THE SOUTHERN TIER LATER IN THE DAY AS GREATER ATLANTIC MOISTURE ROTATES IN FROM THE FL COASTAL LOW PRES SYSTEM. THE REGION REMAINS UNDER EASTERLY FLOW BETWEEN MID ATLANTIC HIGH PRESSURE AND FLORIDA LOW PRESSURE THROUGH THURSDAY. MODEL TIME SECTIONS REMAIN DRY THROUGHOUT...WITH THE EXCEPTION OF THE PERSISTENT MOIST LAYER TRAPPED BENEATH THE SUBSIDENCE INVERSION. WILL FEATURE TEMPERATURES ON LOWER END OF MOS...ABOUT A CATEGORY BELOW NORMAL CLIMATE VALUES FOR TODAY AND TOMORROW. A SLIGHT WARMING TREND IS INDICATED BY LATE WEEK. LONG TERM (THURSDAY NIGHT THROUGH MONDAY)... THE GFS HAS TRENDED TO A MORE WESTWARD DRIFTING SOLUTION WITH REGARD TO THE TROPICAL DISTURBANCE OFF THE S FLORIDA COAST. THE EAST COAST HIGH PRESSURE RIDGE SHOULD KEEP THE SYSTEM SUPPRESSED TO THE SOUTH THROUGH MUCH OF THE MEDIUM RANGE...BUT TROPICAL MOISTURE COULD BEGIN TO ENCROACH ON THE REGION EARLY NEXT WEEK. NO CHANGES WILL BE MADE TO THE CURRENT DRY FORECAST PENDING LATE MORNING COORDINATION WITH HPC. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ RJL sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 344 AM MDT WED SEP 7 2005 .SHORT TERM... (TODAY AND TONIGHT) ...A LOT OF MOISTURE IN THE AIR...POSSIBLE HEAVY RAINS AGAIN TODAY... SUBTROPICAL RAIN PROCESSES GOING ON IN THE ATMOSPHERE OVER SOUTHERN COLORADO. SHOWERS OVER PUEBLO COUNTY LAST EVENING HAD LOTS OF SMALL/MEDIUM DROPS...EXTREME RAINFALL RATES...AND NOT A LOT OF LIGHTNING. HERE AT THE AIRPORT...CLOSE TO 1/2 INCH OF RAIN MEASURED IN THE WEIGHING GAGE IN LESS THAN 30 MINUTES. VISIBILITIES IN THE SHOWERS ON THE WAY INTO WORK WERE DOWN TO 1/4 MILE OR LESS...FORCING DRIVERS TO SLOW WAY DOWN OR EVEN PULL OVER DUE TO EXTREME RAINFALL INTENSITY. ALSO...BOTH MYSELF AND THE OTHER GUY HERE TONIGHT HAD SCARY HYDRO-PLANING STORIES. A LOOK AT SATELLITE PICTURES INDICATES SOUTHERN COLORADO TO REMAIN UNDER A GOOD MONSOON PLUME AGAIN TODAY...SO MORE OF THE SAME AS YESTERDAY EXPECTED IN THE WEATHER DEPARTMENT. WE SHOULD SEE SCATTERED THUNDERSTORMS AGAIN...WITH THE MAIN THREATS BEING LIGHTNING AND HEAVY RAINFALL. RUC PRECIPITABLE WATER VALUES FOR THE PLAINS THIS AFTERNOON ARE FORECAST TO BE GENERALLY AROUND AN INCH OR MORE...WITH ABOUT THREE QUARTERS OF INCH ACROSS THE MOUNTAINS AND HIGH VALLEYS. THESE ARE PRETTY GOOD...ABOUT AS GOOD AS THEY EVER GET. THE SAME CAN BE SAID FOR DEWPOINTS RIGHT NOW...UPPER 50S TO MID 60S ON THE PLAINS...WITH 40S TO LOWER 50S ACROSS THE MOUNTAINS/HIGH VALLEYS. SO...I WOULD THINK THAT HEAVY RAINFALL...AND THE URBAN/SMALL STREAM FLOODING THAT COMES WITH IT WOULD BE THE MAIN CONCERNS TODAY AND TONIGHT. TEMPERATURES TODAY SHOULD END UP CLOSE TO YESTERDAY'S MARKS... WHICH IS STILL ABOVE AVERAGE FOR THIS TIME OF YEAR. LW .LONG TERM... (THURSDAY THROUGH TUESDAY) ABOVE NORMAL TEMPERATURES WITH A DAILY CHANCE FOR PRECIPITATION EXPECTED THROUGH THE EXTENDED PERIOD. THURSDAY AND FRIDAY: THE UPPER HIGH REMAINS PREDOMINANTLY OVER TEXAS...WITH AN UPPER TROUGH OVER THE WEST COAST. THE MOISTURE PLUME OVER THE 4 CORNERS REMAINS SOMEWHAT STATIC ON THURSDAY AND FRIDAY...AND COUPLED WITH LLVL EASTERLY UPSLOPE FLOW FOR THE PLAINS...MEANS A HEALTHY CHANCE FOR PCPN BOTH DAYS. ONGOING GRIDS REFLECTED THIS FOR THURS...BUT HAD TO BOOST POPS AND CLOUD COVER FOR FRI SLIGHTLY. LATEST NUMERICAL GUIDANCE STILL INDICATES VERY WARM TEMPS...SO HOT AND POTENTIALLY STEAMY CONDITIONS ARE ON TAP JUST PRIOR TO THE WEEKEND. FRIDAY NIGHT THROUGH TUESDAY: THE UPPER HIGH IS FORECAST TO WEAKEN AND MIGRATE TO THE EAST TOWARDS THE LOWER MISS RIVER VALLEY THROUGH THE END OF THE FORECAST PERIOD...WHILE THE UPPER TROUGH OUT WEST STRENGTHENS AND MOVES IN TO COVER THE WESTERN THIRD OF THE COUNTRY. THIS SHOULD PRODUCE INCREASING SW FLOW FOR THE HIGHER TERRAIN... ALONG WITH A DRYING WARMER FLOW FOR THE E PLAINS IN THE ABSENCE OF ANY NOTICEABLE UPSLOPE COMPONENT. THE MOISTURE PLUME REMAINS IN PLACE SO DIURNAL SHOWERS AND STORMS FOR THE MTS...HIGH VALLEYS...I- 25 CORRIDOR AND RATON RIDGE LOOKS REASONABLE...WITH THE BEST PCPN WINDOW ALONG THE CONTDVD AND SOUTHERN PORTIONS OF THE CWA. SECOND DAY IN A ROW THAT GFS TRIES TO COOL MAX TEMPS THROUGH THE EXTENDED. FEEL THIS IS THE MODEL TRYING TO LEAN TOWARDS CLIMATOLOGY INSTEAD OF ANY REAL COOLING TREND...BUT RUN TO RUN CONSISTENCY LED ME TO COOL TEMPS A DEGREE OR TWO. HOWEVER...ABOVE NORMAL MAX AND MIN TEMPS STILL IN PLACE. \\MOORE// && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 50/27 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 530 AM EDT WED SEP 7 2005 .UPDATE... WILL UPDATE FCST TO EXPAND PATCHY EARLY MORNING FOG NORTHWARD INTO SRN IND. HNB REPORTING 1/4SM AS OF 0930 UTC. REST OF FCST ON TRACK. CS .SHORT TERM (TODAY-TONIGHT)... ANOTHER QUIET DAY EXPECTED AS THE REGION REMAINS ON THE ERN PERIPHERY OF STRONG UPPER RIDGING LOCATED OVER PLAINS. A BAND OF SCT-BKN MID LEVEL CLOUDS DEVELOPED OVER PARTS OF THE CWA WITHIN THE PAST COUPLE HOURS...CIGS AROUND 7KFT AGL. RUC 800MB RH FIELDS SORT OF PICK UP ON THIS FEATURE AND KEEP SOME SCT CLOUDS IN THE CWA THROUGH SUNRISE. SCT CIRRUS WILL ALSO MOVE OVER PARTS OF IN/IL THROUGH DAYBREAK. OTHER INTERESTING FEATURE OF NOTE IS THAT FOR THE SECOND NIGHT IN A ROW...LIGHT EASTERLIES HAVE PERSISTED INTO THE OVERNIGHT HOURS AT LEX. AS OF 06 UTC...THIS DOWNSLOPING WIND WAS HOLDING DOWN THE LEX DEWPOINT TO 54...WHILE LOW/MID 60S WERE REPORTED ELSEWHERE IN THE CWA. IFR VSBYS POSSIBLE AT BWG THIS MORNING WITH FAVORABLE T/TD/WIND PROFILE IN LOW LEVELS...THOUGH FOG OVERALL WILL TEND TO BE SHALLOW IN NATURE. WILL MENTION PATCHY EARLY MORNING FG FOR THE BWG ZONE. SOME HAZE POSSIBLE AT THE SDF TERMINAL...WITH CLOUDS/HEAT ISLAND LIMITING FURTHER VSBY REDUCTIONS. VSBYS WILL REMAIN UNRESTRICTED AT LEX WITH THE EASTERLY WIND. LATEST ACARS SOUNDINGS AT SDF ARE SHOWING A RATHER STRONG INVERSION AROUND 800MB...SOMETHING WHICH THE 00 UTC NAM FAILED TO PICK UP OR MIXED OUT TOO SOON IN THE MODEL RUN. THIS WOULD HAVE THE TENDENCY TO FLATTEN OUT ANY DIURNAL CU THAT DEVELOP TODAY. GFS/NAM/RUC CONSENSUS SHOWS VERY DRY 800MB AIR ADVECTING INTO LEX/LOU SECTORS OF THE CWA TODAY FURTHER LIMITING CU DEVELOPMENT TO FEW AT BEST. SCT CU POSSIBLE OVER BWG WHERE RH VALUES ARE MORE FAVORABLE. BASED ON LOW LEVEL THICKNESS TRENDS TEMPERATURES SHOULD ONLY BE SLIGHTLY WARMER TODAY COMPARED TO YESTERDAY. WILL GO ABOUT A DEGREE UNDER GFS MOS GUIDANCE...YIELDING MOSTLY MIDDLE 80S THOUGH A COUPLE UPPER 80S READINGS POSSIBLE. MOSTLY CLEAR SKIES ANTICIPATED TONIGHT PER BUFKIT FCST SOUNDINGS. WE COULD SEE SOME CIRRUS SPILL DOWN INTO THE OHIO VALLEY FROM UPSTREAM CONVECTION OVER THE MIDWEST. CS .REST OF THE SHORT TERM (THURSDAY THROUGH FRIDAY NIGHT)... WILL ADD A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR FRIDAY AND FRIDAY NIGHT. SURFACE HIGH PRESSURE PREVIOUSLY IN PLACE ACROSS NEW ENGLAND THROUGH LATE WEDNESDAY WILL WEAKEN AS A COLD FRONT SLOWLY SAGS SOUTH TO PERHAPS THE NORTHERN INDIANA BORDER BY LATE THURSDAY. UPPER AIR PATTERN WILL FEATURE BROAD ZONAL FLOW ACROSS THE NORTHERN CONUS THURSDAY. BY FRIDAY...A SHALLOW...FAST MOVING UPPER FEATURE WILL SCOOT ACROSS INDIANA. IN RESPONSE...WEAK LOW PRESSURE IS EXPECTED TO FORM ACROSS INDIANA AND MOVE EAST INTO OHIO BY EARLY SATURDAY. WHILE I FEEL THAT NAM BRING TOO MUCH MOISTURE IN VICINITY OF SURFACE LOW FRIDAY (UPPER 60 DEWPOINTS)...SOME MOISTURE CONVERGENCE AND UPPER FORCING MAY GENERATE PRECIP...ESPECIALLY ACROSS SOUTHERN INDIANA...FRIDAY INTO SATURDAY MORNING. GFS IS WEAKER AND FARTHER NORTH WITH THE UPPER AIR FEATURE...CONFINING PRECIP ACROSS THE SOUTHERN GREAT LAKES. WITH SPEED OF UPPER AIR FEATURE...ANY CLOUDS OR ASSOCIATE PRECIP SHOULD EXIT AREA BY LATE SATURDAY MORNING. JSD .IN THE EXTENDED (SATURDAY THROUGH WEDNESDAY)... IN RESPONSE TO STRONG RIDGING ACROSS THE EASTERN PACIFIC...UPPER AIR PATTERN ACROSS THE ENTIRE CONUS EXPECTED TO AMPLIFY QUITE A BIT BEGINNING SATURDAY. IN AGREEMENT WITH HPC...WENT WITH ECWMF IN DEVELOPING UNSEASONABLY DEEP TROUGH ACROSS THE WESTERN STATES. ADDITIONAL JET ENERGY MOVING SOUTH INTO TROUGH WILL MAINTAIN IT ACROSS THE WESTERN STATES THROUGH WEDNESDAY. CONVERSELY...HIGH AMPLITUDE RIDGE WILL DEVELOP ACROSS THE EASTERN CONUS...ACTUALLY CENTERING ACROSS THE LOWER OHIO VALLEY BY MONDAY. WITH SUCH A STRONG RIDGE IN PLACE EXPECT DRY WEATHER WITH DISTINCTLY WARMER THAN NORMAL TEMPERATURES THROUGH AT LEAST WEDNESDAY. JSD && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 225 AM EDT WED SEP 7 2005 .SHORT TERM (TODAY-TONIGHT)... ANOTHER QUIET DAY EXPECTED AS THE REGION REMAINS ON THE ERN PERIPHERY OF STRONG UPPER RIDGING LOCATED OVER PLAINS. A BAND OF SCT-BKN MID LEVEL CLOUDS DEVELOPED OVER PARTS OF THE CWA WITHIN THE PAST COUPLE HOURS...CIGS AROUND 7KFT AGL. RUC 800MB RH FIELDS SORT OF PICK UP ON THIS FEATURE AND KEEP SOME SCT CLOUDS IN THE CWA THROUGH SUNRISE. SCT CIRRUS WILL ALSO MOVE OVER PARTS OF IN/IL THROUGH DAYBREAK. OTHER INTERESTING FEATURE OF NOTE IS THAT FOR THE SECOND NIGHT IN A ROW...LIGHT EASTERLIES HAVE PERSISTED INTO THE OVERNIGHT HOURS AT LEX. AS OF 06 UTC...THIS DOWNSLOPING WIND WAS HOLDING DOWN THE LEX DEWPOINT TO 54...WHILE LOW/MID 60S WERE REPORTED ELSEWHERE IN THE CWA. IFR VSBYS POSSIBLE AT BWG THIS MORNING WITH FAVORABLE T/TD/WIND PROFILE IN LOW LEVELS...THOUGH FOG OVERALL WILL TEND TO BE SHALLOW IN NATURE. WILL MENTION PATCHY EARLY MORNING FG FOR THE BWG ZONE. SOME HAZE POSSIBLE AT THE SDF TERMINAL...WITH CLOUDS/HEAT ISLAND LIMITING FURTHER VSBY REDUCTIONS. VSBYS WILL REMAIN UNRESTRICTED AT LEX WITH THE EASTERLY WIND. LATEST ACARS SOUNDINGS AT SDF ARE SHOWING A RATHER STRONG INVERSION AROUND 800MB...SOMETHING WHICH THE 00 UTC NAM FAILED TO PICK UP OR MIXED OUT TOO SOON IN THE MODEL RUN. THIS WOULD HAVE THE TENDENCY TO FLATTEN OUT ANY DIURNAL CU THAT DEVELOP TODAY. GFS/NAM/RUC CONSENSUS SHOWS VERY DRY 800MB AIR ADVECTING INTO LEX/LOU SECTORS OF THE CWA TODAY FURTHER LIMITING CU DEVELOPMENT TO FEW AT BEST. SCT CU POSSIBLE OVER BWG WHERE RH VALUES ARE MORE FAVORABLE. BASED ON LOW LEVEL THICKNESS TRENDS TEMPERATURES SHOULD ONLY BE SLIGHTLY WARMER TODAY COMPARED TO YESTERDAY. WILL GO ABOUT A DEGREE UNDER GFS MOS GUIDANCE...YIELDING MOSTLY MIDDLE 80S THOUGH A COUPLE UPPER 80S READINGS POSSIBLE. MOSTLY CLEAR SKIES ANTICIPATED TONIGHT PER BUFKIT FCST SOUNDINGS. WE COULD SEE SOME CIRRUS SPILL DOWN INTO THE OHIO VALLEY FROM UPSTREAM CONVECTION OVER THE MIDWEST. CS .REST OF THE SHORT TERM (THURSDAY THROUGH FRIDAY NIGHT)... WILL ADD A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR FRIDAY AND FRIDAY NIGHT. SURFACE HIGH PRESSURE PREVIOUSLY IN PLACE ACROSS NEW ENGLAND THROUGH LATE WEDNESDAY WILL WEAKEN AS A COLD FRONT SLOWLY SAGS SOUTH TO PERHAPS THE NORTHERN INDIANA BORDER BY LATE THURSDAY. UPPER AIR PATTERN WILL FEATURE BROAD ZONAL FLOW ACROSS THE NORTHERN CONUS THURSDAY. BY FRIDAY...A SHALLOW...FAST MOVING UPPER FEATURE WILL SCOOT ACROSS INDIANA. IN RESPONSE...WEAK LOW PRESSURE IS EXPECTED TO FORM ACROSS INDIANA AND MOVE EAST INTO OHIO BY EARLY SATURDAY. WHILE I FEEL THAT NAM BRING TOO MUCH MOISTURE IN VICINITY OF SURFACE LOW FRIDAY (UPPER 60 DEWPOINTS)...SOME MOISTURE CONVERGENCE AND UPPER FORCING MAY GENERATE PRECIP...ESPECIALLY ACROSS SOUTHERN INDIANA...FRIDAY INTO SATURDAY MORNING. GFS IS WEAKER AND FARTHER NORTH WITH THE UPPER AIR FEATURE...CONFINING PRECIP ACROSS THE SOUTHERN GREAT LAKES. WITH SPEED OF UPPER AIR FEATURE...ANY CLOUDS OR ASSOCIATE PRECIP SHOULD EXIT AREA BY LATE SATURDAY MORNING. JSD .IN THE EXTENDED (SATURDAY THROUGH WEDNESDAY)... IN RESPONSE TO STRONG RIDGING ACROSS THE EASTERN PACIFIC...UPPER AIR PATTERN ACROSS THE ENTIRE CONUS EXPECTED TO AMPLIFY QUITE A BIT BEGINNING SATURDAY. IN AGREEMENT WITH HPC...WENT WITH ECWMF IN DEVELOPING UNSEASONABLY DEEP TROUGH ACROSS THE WESTERN STATES. ADDITIONAL JET ENERGY MOVING SOUTH INTO TROUGH WILL MAINTAIN IT ACROSS THE WESTERN STATES THROUGH WEDNESDAY. CONVERSELY...HIGH AMPLITUDE RIDGE WILL DEVELOP ACROSS THE EASTERN CONUS...ACTUALLY CENTERING ACROSS THE LOWER OHIO VALLEY BY MONDAY. WITH SUCH A STRONG RIDGE IN PLACE EXPECT DRY WEATHER WITH DISTINCTLY WARMER THAN NORMAL TEMPERATURES THROUGH AT LEAST WEDNESDAY. JSD && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 320 AM EDT WED SEP 7 2005 .DISCUSSION... 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW THE SAME OLD ERN RDG/WRN TROF UPR PATTERN ACRS NAMERICA. POTENT SHRTWV CURRENTLY MOVING THRU FAR NW ONTARIO IS RIDING OVER THE ERN RDG...AND UPR FLOW IS TENDING TO BCM MORE WLY ALF OVER THE UPR GRT LKS IN RESPONSE TO THIS SYS. THIS MORE WLY FLOW HAS ADVECTED MUCH DRIER AIR SHOWN ON THE 00Z INL SDNG (PWAT 0.50 INCH...KINX -11 WITH H7 DEWPT DEPRESSION OF 35C) INTO THE FA ALF EVEN AHD OF SFC/H85 COOL FNT NOW MOVING INTO THE WRN FA. SO JUST SOME SCT-BKN CLD MARKS THE FNT WITH SFC DWPTS FALLING INTO THE UPR 40S OVER NRN MN. AXIS OF HIER MSTR THAT CAUSED A FEW -SHRA OVER THE FA YDAY HAS PUSHED TO THE E. HOWEVER... GRADIENT OF MSTR TO THE S IS QUITE SHARP...BIS SDNG SHOWS PWAT 0.75 INCH WITH HI RH BTWN H7-4. MPX SDNG IS EVEN MORE MOIST WITH PWAT 1.36 INCH... KINX 24 AND FAIRLY STEEP H7-5 LAPSE RATES. BUT H7 DEWPT DEPRESSION THERE 17C. A FEW -SHRA HAVE EVEN POPPED UP OVER THE MN/ND BORDER WHERE FAIRLY IMPRESSIVE H85-3 QVECTOR CNVGC IN RRQ OF UPR JET SUPPORTING ONTARIO SHRTWV ACTING ON THE MID LVL MSTR SHOWN ON THE BIS SDNG. THE MID LVL DRY AIR SHOWN ON THE MPX SDNG APPEARS TO BE THE REASON THE PCPN IS NOT MORE WDSPRD DESPITE THE IMPRESSIVE DYNAMICS. MAIN FCST CONCERNS THIS PACKAGE REVOLVE ARND SML PCPN CHCS OVER THE SRN TIER THIS MRNG...THEN PRIMARILY TEMPS WITH SFC HI PRES FCST TO BUILD OVER THE UPR GRT LKS THE NEXT COUPLE OF DAYS. SOME CONCERN FOR PCPN CHCS THU/THU NGT. FOR TDAY...SHRTWV OVER FAR NW ONTARIO PROGGED TO MOVE E INTO NW QUEBEC BY 00Z THU...CAUSING CONFLUENT UPR FLOW TO GRDLY VEER MORE WNW AND PUSH AREA OF PWAT AOB 0.5 INCH OVER THE FA. SFC HI PRES RDG NOW IN THE NRN PLAINS FCST TO REACH NCNTRL MN UNDER THIS UPR CONFLUENCE BY DAYS END. BEFORE ALL THIS DRYING HOWEVER...CONCERN THAT STEEPER LAPSE RATES/DYNAMICS IN RRQ OF UPR JET TO THE N MAY BE SUFFICIENT TO TRIGGER PCPN OVER THE SRN TIER ZNS CLOSER TO THE DEEPER MSTR. BUT SINCE H7 DEWPT DEPRESSION ON THE MPX SDNG IS SO HI...WL ASSUME THE ATMOSPHERE WL REMAIN PROHIBITIVELY DRY FOR ANY PCPN. BY THE TIME THE HIER MID LVL RH SHOWN ON THE BIS SDNG WOULD MOVE IN...UPR FLOW SHOULD VEER ENUF TO SHUNT THIS MSTR OFF TO THE S. SO WL GO WITH NAM ZERO QPF AND GOING DRY FCST...WITH JUST SOME SCT-BKN CLDS THIS MRNG OVER MAINLY THE SRN TIER. DURING THE AFTN... DRYING FM THE NW SHOULD ALLOW SKIES TO BCM MOSUNNY. AS FOR HI TEMPS...GFS/NAM SHOW H85 TEMPS FALLING TO 9 OR 10C BY THE END OF THE DAY. MIXING TO H85/BASE OF DVLPG SUBSIDENCE INVRN ON NAM FCST SDNGS YIELDS TMAX APRCH 75 OVER THE SCNTRL AWAY FM LK INFLUENCE. HI PRES FCST TO MOVE OVHD TNGT UNDER CONFLUENT WNW FLOW ALF. NAM MOST AGGRESSIVE AT DROPPING SHRTWV THRU ONTARIO...WITH STRONGER H925 NW WINDS FCST THAN GFS OVER LK SUP. UNCERTAINTY HERE MOST CRITICAL FOR THE ZNS NR LK SUP FM THE KEWEENAW EWD. FOR THE WI BORDER AND INTERIOR W...FCST PWAT AOB 0.50 INCH AND LGT WINDS WL ALLOW FOR EFFICIENT RADIATIONAL COOLING...SO WL GO BLO MOS GUIDANCE FOR LO TEMPS OVER THESE AREAS. CONSIDERING SFC DWPTS IN THE UPR 30S UPSTREAM THIS MRNG...COLDER INTERIOR LOCATIONS MIGHT SEE SOME MID 30S AND FROST. BUT AREAL COVG OF FROST AND UNCERTAINTY WITH STRENGTH OF H925 WINDS NOT ENUF TO WARRANT ANY KIND OF HEADLINE ATTM. QUITE A BIT OF MODEL DISCREPANCIES CONCERNING FCST FOR THU AND TRACK OF SHRWTV PROGGED TO SINK SEWD THRU THE UPR MIDWEST. NAM/NGM SHOW DRY WNW FLOW SHUNTING THIS SHRTWV WELL TO THE S...WITH NO PCPN. GFS AND UKMET ON THE OTHER HAND SHOW SHRTWV TRACK FARTHER N THRU WI... WITH PCPN FCST OVER MUCH OF THE U.P. THE GFS APPEARS TO SUFFER FM CONVECTIVE FEEDBACK...WHICH RESULTS IN ARTIFICIALLY ENHANCED H85 WINDS/OVRRNG/FRONTOGENESIS. UKMET FCST OF MUCH MORE CONCERN...WITH SGNFT UPR DVGC IN RRQ OF 100KT H25 JET MAX OVER ONTARIO IMPACTING THE FA LATE IN THE AFTN. EVEN SO...STRONGEST H85 WINDS/BEST ISENTROPIC LIFT ON THE 305K SFC REMAIN FOCUSED ON STNRY FNT WELL TO THE S. THIS SOLN SUGS A THICK MID/HI OVC WOULD OVERSPRD THE AREA ESPECIALLY THE W AND SCNTRL...WITH JUST SOME -RA/--RA MAINLY NR THE WI BORDER. CNDN MODEL SHOWS SOME LGT PCPN NR THE WI BORDER. BUT SINCE GOING FCST IS DRY ATTM... SOME MODELS INDICATE A DRY DAY...ANTECEDENT AIRMASS IS SO DRY...AND COORDINATION WITH GRB INDICATES THEY WL BE ADDING JUST A 30 POP ALG THE BORDER...WL MAINTAIN GOING DRY FCST AND JUST INCRS AMT OF MID/HI CLD FOR NOW. DESPITE DIFFERENCES IN INCRSG HI LVL RH...NAM/GFS FCST SDNGS SUG TMAX WL REACH 70-75. DESPITE THEIR DIFFERENCES ON THU WX...ALL MODELS SHOW SHRTWV DIGGING TO THE SE AND AWAY FM THE FA ON THU NGT. RESULT IS DRYING ALF DOWNSTREAM OF BLDG RDG ACRS THE PLAINS AND UNDER UPR CNVGC/QVECTOR DVGC. LOWEST TEMPS ON THU NGT WL BE OVER THE E...CLOSER TO LOWER PWAT ON THE NRN FLANK OF SHRTWV DIVING TO THE SE. FRI SHOULD BE A RATHER PLEASANT DAY WITH SFC HI PRES/ACYC FLOW/AREA OF LOWER PWAT DOMINATING JUST DOWNWIND OF UPR RDG AXIS. GFS/UKMET SHOW H85 TEMPS RISING TO ARND 15C BY LATE IN THE DAY AT IWD...WHICH SUPPORTS HI TEMPS RISING TOWARD 80 ESPECIALLY WITH DOWNSLOPING SSE FLOW THERE. COORDINATED WITH GRB. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 257 AM CDT WED SEP 7 2005 .DISCUSSION... PRECIP CHANCES CONTINUE TO BE THE MAIN FORECAST FOCUS. WIDELY SCATTERED SHOWERS HAVE MOVED INTO EXTREME NORTHWEST CORNER OF MISSOURI THIS MORNING. THIS ACTIVITY IS WEAKENING AS IT MOVES EAST...FOR REASONS MENTIONED IN PREVIOUS DISCUSSION. ACTIVITY CONTINUES TO GENERATE IN SOUTHEAST NEBRASKA...SO WILL CONTINUE LOW CHANCE POPS THIS MORNING ACROSS THE NORTHWEST. A WEAK SURFACE BOUNDARY IS SITTING ACROSS CENTRAL IOWA EARLY THIS MORNING. THIS MAY MOVE A LITTLE FARTHER SOUTH DURING THE DAY...SLOWLY EDGING SOUTH AND WASHING OUT BEFORE FRIDAY. LITTLE TO NO CONVERGENCE ALONG THIS BOUNDARY...WITH MAINLY KINEMATIC PROCESSES CAUSING PRECIPITATION. CANNOT GET TOO EXCITED ABOUT THIS...AND HAVE CONTINUED ONLY LOW POPS. THE CHALLENGE WITH TEMPS CENTERS ON CLOUD COVER. AIRMASS HAS NOT REALLY CHANGED...AND NOT EXPECTED TO...WITH H8 TEMPS REMAINING IN THE 18-20C RANGE. SO WITH A PERSISTENCE FORECAST...HAVE ONLY LOWERED TEMPS SLIGHTLY IN NORTHERN MO DUE TO MORE CLOUDS. HAD QUITE A FEW CLOUDS AROUND YESTERDAY AND STILL MANAGED TO MAKE IT INTO THE UPPER 80S IN SEVERAL LOCATIONS...SO WON'T BACK OFF TEMPS TOO MUCH. LVK .PREV DISCUSSION... 945 PM TUE... SHOWERS IN SOUTHEAST NEBRASKA ARE SLOWLY ADVANCING TOWARD THE NORTHWEST TIP OF MISSOURI. METARS FROM CONCORDIA AND BEATRICE SUGGEST THAT CLOUD BASES ARE QUITE HIGH (8000 TO 12000 FT) AND THE SOUNDING FROM TOPEKA CONFIRMS THAT THE LOW LEVELS OF THE ATMOSPHERIC COLUMN ARE DRY. ONE MUST LOOK TO 700MB TO FIND THE SOURCE OF LIFT FOR THE SHOWERS IN SOUTHEAST NEBRASKA. PROFILERS AND RUC ANALYSIS INDICATE MODEST THETA-E ADVECTION FROM HASTINGS TO FALLS CITY DIMINISHING SUBSTANTIALLY OVER NORTHWEST MISSOURI. UPGLIDE OVER THE SAME AREA CAN BE INFERRED ON THE RUC 310 THETA SURFACE. LIFT IS NOT FORECAST BY THE RUC TO MOVE EAST MUCH OVERNIGHT SO I HAVE ONLY INCLUDED LOW CHANCES OF SHOWERS IN DONIPHAN, HOLT AND ATCHISON COUNTIES THROUGH SUNRISE. CHANCES FOR THUNDER DO NOT LOOK GOOD SINCE MID LEVEL LAPSE RATES ARE POOR (BARELY MOIST ADIABATIC). KOCH 334 PM... FORECAST CONCERN IS FOR RAIN CHANCES THROUGH THE NEXT SEVERAL DAYS. WATCHING TWO MAIN AREAS. SCATTERED CONVECTION PERSISTED ACROSS CENTRAL KANSAS IN AREA OF LIFT WITHIN THE SUBTROPICAL MOISTURE PLUME. THIS HAS EVEN GENERATED A WEAK MCV ACROSS NORTHERN KANSAS. WITH THE MCV PUSHING CLOSE TO EXTREME NORTHWEST MISSOURI...HAVE ADDED SLIGHT CHANCE POPS TO THAT AREA FOR THIS EVENING. DO NOT THINK THE SCATTERED PRECIP OVER CENTRAL KANSAS WILL HAVE ENOUGH ENERGY TO MAKE IT TO THE MISSOURI-KANSAS BORDER AS WINDS ACROSS WESTERN KANSAS HAVE BEGUN TO BACK. CONVECTION FROM LAST NIGHT MANAGED TO PUSH A WEAK OUTFLOW BOUNDARY INTO EXTREME NORTHERN MISSOURI THIS MORNING. THAT BOUNDARY HAS SINCE WASHED OUT. HOWEVER THE WEAK COLD FRONT IS PUSHING A LITTLE CLOSER...ACROSS NORTHERN NEBRASKA INTO NORTHWEST IOWA. CONVECTION HAS BEEN FIRING ALONG THIS FRONT ACROSS NORTHEAST NEBRASKA. THIS IS THE SECOND AREA TO WATCH. HAVE HELD ON TO THE SLIGHT CHANCE POPS ACROSS NORTHERN MISSOURI AS PERIODS OF ISENTROPIC LIFT ARE GENERATED ALONG AND SOUTH OF THE FRONT...WHICH MAY JUST EDGE INTO THE AREA. BOTH THE GFS AND NAM SUGGEST HIGH RH AND PERIODS OF ISENTROPIC LIFT ACROSS NORTHERN MISSOURI BEGINNING WEDNESDAY...CONTINUING INTO THURSDAY. HAVE MAINTAINED LOW CHANCE POPS FOR NORTHERN MISSOURI DURING THAT TIME. HAVE NOT GONE HIGHER WITH THE ACTUAL LOCATION OF THE BOUNDARY STILL IN QUESTION. CURRENT TEMP FORECAST REMAINS ON TRACK WITH COOLER TEMPS ACROSS THE NORTH AND HIGHS IN THE UPPER 80S TO AROUND 90 IN THE SOUTH. IF RAIN SETS UP ACROSS NORTHERN MISSOURI...LATER SHIFTS WILL NEED TO LOWER HIGHS IN THAT AREA BY SEVERAL CATEGORIES. UPPER RIDGING BEGINS TO AMPLIFY AND SHIFT EAST BY THE WEEKEND AS TROUGHING INCREASES OVER THE WEST. THIS WILL LEAVE THE FORECAST AREA WITHIN SOUTHWEST FLOW ALOFT. FEW CHANGES MADE TO THE EXTENDED FORECAST...OTHER THAN BUMPING TEMPERATURES UP A DEGREE OR TWO HERE AND THERE. THE NEXT FRONT TO OUR WEST LOOKS LIKE IT WILL HOLD OFF REACHING THE AREA UNTIL AFTER THE 7 DAY FORECAST...SO KEPT THE FORECAST FROM FRIDAY THROUGH TUESDAY DRY. NRR/STOFLET && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. $$ WFO EAX mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 308 AM EDT WED SEP 7 2005 ...HIGH SURF AND DANGEROUS RIP CURRENTS TO CONTINUE AT THE COAST... ...TROPICAL STORM OPHELIA STRENGTHENING OFF THE CNTRL FL COAST... ATTENTION CUSTOMERS AND PARTNERS...SEVERAL OF OUR FORECASTS PRODUCTS MAY BE DELAYED UNTIL AFTER THE 4 AM CONFERENCE CALL WITH THE NHC SO THAT THE LATEST INFORMATION ON TS OPHELIA CAN BE INCORPORATED INTO THE FORECAST. WE APPRECIATE YOUR PATIENCE. .SHORT TERM /TODAY THROUGH THURSDAY/...THE AREA REMAINS CAUGHT BTWN HIGH PRES CNTRD OVR VA AND DVLPG TS OPHELIA OFF THE CNTRL FL COAST. ATTENDANT GULF STREAM INSTABILITY AND STRONG LOW-LVL CONVERGENCE IS HELPING TO DRIVE THE DVLPMNT OF SCATTERED SHOWERS ACROSS THE COASTAL WTRS THIS MRNG. SIMILAR TO YDA THIS ACTIVITY SHOULD EXPAND CLOSER TO THE COAST AS THE DAY PROGRESSES BUT DRIER MID-LVL AIR IN PLACE ACROSS THE MIDLANDS AND E-CNTRL GA WL SEVERELY LIMIT PCPN CHANCES WELL INLAND. NE TRAJECTORIES WL KEEP THE HIGHEST POPS ALONG THE GA COAST WHICH IS CONSISTENT WITH THE PREVIOUS FCST. WL LYR POPS FROM 20 PCNT WELL INLAND TO 60 PCNT ALONG MOST OF THE N GA COAST THROUGH MID EVNG THEN TAPER POPS BACK SLGTLY AFT MIDNGT. COULD SEE SOME LOCALIZED FLOODING IN A FEW LOCATIONS WHERE TRAINING OCCURS...BUT THE OVERALL FLOOD RISK IS TO TOO SMALL TO WARRANT A FLOOD WATCH ATTM. WOULD NOT BE SURPRISED TO SEE A FEW LOCATIONS ALONG THE GA COAST RECEIVE A QUICK 1-2 INCHES BY THIS EVNG. TEMPS WL CONT BLO CLIMO WITH HIGHS IN THE MID 80S. BREEZY CONDITIONS ARE XPCTD AGAIN TODAY WITH A PINCHED GRADIENT HOLDING FIRM ACROSS THE AREA. WNDS AT COASTAL SITES ARE STILL IN THE 15-20 MPH RANGE AT THIS HR WITH OCNL GUSTS TO 30 MPH. WNDS OVR LAKE MOULTRIE WL LIKELY REACH THE 15-25 KT RANGE LTR THIS MRNG AS HIGHER WNDS ALOFT MIX DOWN. PER COORDINATION WITH WFO CAE...WL GO WITH A LAKE WIND ADV FOR LAKE MOULTRIE THROUGH 9 PM TNGT. SIMILAR CONDITIONS ARE EXPECTED ON THU WITH THE HIGHEST POPS CONFINED TO COASTAL GA. THE NAM IS INSISTENT THAT MID-LVL DRY AIR WL FILTER IN ALL THE WAY TO THE COAST BUT AM DOUBTFUL THIS WL OCCUR GIVEN HOW OPHELIA/S CIRCULATION IS EXPANDING. WL KEEP THE HIGHEST POPS ALONG THE GA COAST...SIMILAR TO TDA. && .LONG TERM /FRIDAY THROUGH TUESDAY/...MUCH OF THE EXTENDED FCST WL BE DEPENDENT ON THE EVOLUTION OF TS OPHELIA. OPHELIA APPEARS TO BE BECMG BTR ORGANIZED THIS MRNG OFF THE CNTRL FL COAST WITH CONVECTION TRYING TO CONSOLIDATE CLOSER TO THE CNTR OF CIRCULATION. THE 07/03Z NHC TRACK TAKES OPHELIA INTO THE NE FL COAST SAT EVNG AS A STRONG TS. THE 07/00Z GLOBAL MODELS ARE SHOWING A DISTINCT BIFURCATION IN THE FCST TRACK. ONE SET TAKES THE STORM ACROSS FL INTO THE NE GULF WITH THE SECOND MOVING THE SYSTEM N THEN VEERING IT OUT TO SEA OFF THE THE SC/GA COASTS. AM HESITANT TO MAKE ANY MAJOR CHANGES GIVEN THESE TRENDS BUT WL OPT TO MAKE SOME LAST MINUTE CHANGES AFT THE 4 AM NHC CONFERENCE CALL. IF THE 07/03Z NHC TRACK HOLDS TRUE...TS FORCE WNDS AND FLOODING RAINS COULD IMPACT PORTIONS OF THE FCST AREA THIS WEEKEND. RESIDENTS AND VISITORS ACROSS SRN SC AND SE GA SHOULD CONTINUE TO CAREFULLY MONITOR FUTURE FCSTS. && .AVIATION...APPEARS THAT SCT TO BKN MID CLOUDINESS HAS DELAYED THE DECOUPLING OF THE SFC WINDS AT KCHS THIS MORNING. STILL GUSTING TO ARND 20 KT ATTM. THIS SHOULD SLACKEN A LITTLE DURING THE REST OF THE MORNING WITH ANOTHER SURGE AT BOTH SITES ON WED. CURRENT SHRA ACTIVITY EXPECTED TO STAY OFFSHORE BASED ON THE STEERING FLOW...BUT AS WIND VEERS THIS AFTERNOON THERE COULD BE ENOUGH CONVERGENCE ALONG THE COAST FOR SOME LIGHT SHOWERS. WILL KEEP PROB30 TO ACCOUNT FOR THIS. GFS PROG SHOWS SOME GOOD MOIST ISENTROPIC UPGLIDE STARTING AROUND DAYBREAK ALONG THE COAST AND CONTINUING THROUGH THE DAY. THIS WOULD BE SIMILAR TO YESTERDAY/S SETUP...THUS HAVE KEPT MVFR CIGS AT BOTH SITES FOR THE MORNING HRS. && .MARINE...THE UPPER LONGWAVE PATTERN STILL SUPPORTS THE WEAKENING OF THE SFC HIGH OVER THE MID-ATLC REGION ON THURSDAY. HOWEVER...TS OPHELIA IS EXPECTED TO SLOWLY STRENGTHEN OFF THE FL COAST THROUGH THE WEEKEND...INCHING NORTHWEST. THIS WILL BEGIN TO TAKE OVER AS THE PRIMARY CAUSE FOR STRONG WINDS AND CONTINUED HIGH SEAS ACROSS MOST OF OUR WATERS TOWARD THE END OF THE WEEK. UNFORTUNATELY THERE IS LITTLE GUIDANCE TO WORK WITH THIS MORNING. NAM LOSES THE CIRCULATION OF OPHELIA WITHIN 12 HRS OF INITIALIZATION. RUC TAKES IT IMMEDIATELY INLAND OVER ERN FL. GFS AND UKMET TAKE THE SYSTEM NWWD THROUGH FRIDAY BEFORE A TURN TO THE NE SAT MORNING. THESE SOLNS ARE CLOSE TO THE NHC TRACK FOR THE FIRST THREE DAYS AND WILL BE FOLLOWED. WITH WINDS STILL HOWLING ACROSS THE SRN WATERS THIS MORNING...DO NOT FEEL CONFIDENT IN LOWERING GALE WARNING FOR GA OFFSHORE WATERS...ESPECIALLY WITH A STRENGTHENING TROPICAL SYSTEM EXPECTED TO MOVE CLOSER. WILL EXTEND THE GALE THROUGH 22Z. ALSO...THE SCA FOR THE CHS HARBOR WAS SUPPOSED TO EXPIRE THIS EVENING BUT I EXTENDED IT ANOTHER 24 HRS. && .RIP CURRENTS...WILL CONTINUE THE HIGH RISK TODAY. STRONG NELY WINDS WITH CHOPPY 3-5 FT SURF WILL KEEP NEARSHORE QUITE HAZARDOUS TO SWIMMERS. THE LONGSHORE CURRENT WILL REMAIN STRONG TODAY ADDING ANOTHER HAZARD TO SWIMMERS. && .HIGH SURF AND EROSION...WILL EXTEND HIGH SURF ADVY UP THE COAST TO INCLUDE OUR ENTIRE COASTLINE. REALLY NO CHANGE EXPECTED TODAY IN WIND SPEED OR DIRECTION...AND HAD REPORTS OF 5-7 FT BREAKERS AT FOLLY BEACH YESTERDAY WHICH EASILY MEETS CRITERIA. WILL ALSO STRESS POSSIBILITY OF SIGNIFICANT BEACH EROSION DUE TO THIS BEING A PROLONGED NE FLOW EVENT. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...HIGH SURF ADVISORY UNTIL 9 PM GAZ117-119-139-141. SC...HIGH SURF ADVISORY UNTIL 9 PM SCZ048>051 ...LAKE WIND ADVISORY FOR LAKE MOULTRIE UNTIL 9 PM SCZ045. MARINE...GALE WARNING AMZ374. SMALL CRAFT ADVISORY AMZ330-350-352-354. && $$ ST/JRL sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 958 AM EDT WED SEP 7 2005 .UPDATE...TROPICAL STORM OPHELIA IS CENTERED ABOUT 80 MILES EAST OF CAPE CANAVERAL FL, MOVING SLOWLY NORTHWARD. CONVERGENT RAINBANDS CONTINUE TO MOVE ASHORE OVER NORTHEAST FL. VISIBLE IMAGERY SHOWS THE WESTERN FRINGES OF LOW/MID CLOUDS ENTERING OUR EASTERNMOST COUNTIES. A TIGHT SURFACE PRESSURE GRADIENT BETWEEN STRONG RIDGE TO THE NORTH AND OPHELIA TO THE EAST IS GENERATING BREEZY NORTHEAST WINDS. THE LOCAL SOUNDING PRECIP WATER REMAINS UNCHANGED, HOWEVER IT IS MORE STABLE DUE TO WARMING IN THE 500-700 MB LAYER. && .SHORT TERM...LOWERED 12-18Z POP GRIDS SLIGHTLY TO MATCH RADAR TRENDS AND BLEND WITH NEIGHBORING WFOS. ALSO TWEAKED WIND, WEATHER AND SKY GRIDS FOR THIS AFTERNOON. && .MARINE...NORTHEAST WINDS AROUND 20 KNOTS GUSTING TO 25. SEAS AVERAGED 7 FEET AT THE BUOYS. BASED ON RUC, WINDS AND SEAS ARE PROGGED TO DECREASE TO EXERCISE CAUTION CRITERIA OVER THE WESTERN LEGS, WHILE REMAINING AT ADVISORY CRITERIA OVER THE EASTERN LEGS FOR THE REST OF TODAY. && .FIRE WEATHER...ASIDE FROM HIGH DISPERSIONS, NO CONCERNS ANTICIPATED. && .AVIATION...PREVAILING VFR WITH GUSTY NORTHEAST WINDS AT TIMES. SCT SHRA/ISOLD TS MAY REDUCE CIGS/VSBYS TO MVFR THIS AFTERNOON AT VLD. && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...SMALL CRAFT ADVISORY GMZ755-775. && $$ MAJ fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 955 AM EDT WED SEP 7 2005 .SHORT TERM UPDATE... MID LEVEL CLOUDINESS PERSISTS FROM CVG TO SDF TO KBWG...MOSTLY CLEAR ACROSS REST OF FORECAST AREA. WILL HAVE TO TWEAK CLOUDS SOME IN THE GRIDS...AND DEWPTS SLIGHTLY. TEMPS LOOK ON TRACK...THO BWG HAS HAD FOG WHICH HAS KEPT TEMPS LAGGING THE GRIDS 3 TO 5 DEGREES WHICH SHOULD RECOVER QUICKLY WITH FOG BURNING OFF. WILL REMOVE MORNING WORDING MENTIONING FOG. --SCHOTT .SHORT TERM (TODAY-TONIGHT)... ANOTHER QUIET DAY EXPECTED AS THE REGION REMAINS ON THE ERN PERIPHERY OF STRONG UPPER RIDGING LOCATED OVER PLAINS. A BAND OF SCT-BKN MID LEVEL CLOUDS DEVELOPED OVER PARTS OF THE CWA WITHIN THE PAST COUPLE HOURS...CIGS AROUND 7KFT AGL. RUC 800MB RH FIELDS SORT OF PICK UP ON THIS FEATURE AND KEEP SOME SCT CLOUDS IN THE CWA THROUGH SUNRISE. SCT CIRRUS WILL ALSO MOVE OVER PARTS OF IN/IL THROUGH DAYBREAK. OTHER INTERESTING FEATURE OF NOTE IS THAT FOR THE SECOND NIGHT IN A ROW...LIGHT EASTERLIES HAVE PERSISTED INTO THE OVERNIGHT HOURS AT LEX. AS OF 06 UTC...THIS DOWNSLOPING WIND WAS HOLDING DOWN THE LEX DEWPOINT TO 54...WHILE LOW/MID 60S WERE REPORTED ELSEWHERE IN THE CWA. IFR VSBYS POSSIBLE AT BWG THIS MORNING WITH FAVORABLE T/TD/WIND PROFILE IN LOW LEVELS...THOUGH FOG OVERALL WILL TEND TO BE SHALLOW IN NATURE. WILL MENTION PATCHY EARLY MORNING FG FOR THE BWG ZONE. SOME HAZE POSSIBLE AT THE SDF TERMINAL...WITH CLOUDS/HEAT ISLAND LIMITING FURTHER VSBY REDUCTIONS. VSBYS WILL REMAIN UNRESTRICTED AT LEX WITH THE EASTERLY WIND. LATEST ACARS SOUNDINGS AT SDF ARE SHOWING A RATHER STRONG INVERSION AROUND 800MB...SOMETHING WHICH THE 00 UTC NAM FAILED TO PICK UP OR MIXED OUT TOO SOON IN THE MODEL RUN. THIS WOULD HAVE THE TENDENCY TO FLATTEN OUT ANY DIURNAL CU THAT DEVELOP TODAY. GFS/NAM/RUC CONSENSUS SHOWS VERY DRY 800MB AIR ADVECTING INTO LEX/LOU SECTORS OF THE CWA TODAY FURTHER LIMITING CU DEVELOPMENT TO FEW AT BEST. SCT CU POSSIBLE OVER BWG WHERE RH VALUES ARE MORE FAVORABLE. BASED ON LOW LEVEL THICKNESS TRENDS TEMPERATURES SHOULD ONLY BE SLIGHTLY WARMER TODAY COMPARED TO YESTERDAY. WILL GO ABOUT A DEGREE UNDER GFS MOS GUIDANCE...YIELDING MOSTLY MIDDLE 80S THOUGH A COUPLE UPPER 80S READINGS POSSIBLE. MOSTLY CLEAR SKIES ANTICIPATED TONIGHT PER BUFKIT FCST SOUNDINGS. WE COULD SEE SOME CIRRUS SPILL DOWN INTO THE OHIO VALLEY FROM UPSTREAM CONVECTION OVER THE MIDWEST. CS .REST OF THE SHORT TERM (THURSDAY THROUGH FRIDAY NIGHT)... WILL ADD A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR FRIDAY AND FRIDAY NIGHT. SURFACE HIGH PRESSURE PREVIOUSLY IN PLACE ACROSS NEW ENGLAND THROUGH LATE WEDNESDAY WILL WEAKEN AS A COLD FRONT SLOWLY SAGS SOUTH TO PERHAPS THE NORTHERN INDIANA BORDER BY LATE THURSDAY. UPPER AIR PATTERN WILL FEATURE BROAD ZONAL FLOW ACROSS THE NORTHERN CONUS THURSDAY. BY FRIDAY...A SHALLOW...FAST MOVING UPPER FEATURE WILL SCOOT ACROSS INDIANA. IN RESPONSE...WEAK LOW PRESSURE IS EXPECTED TO FORM ACROSS INDIANA AND MOVE EAST INTO OHIO BY EARLY SATURDAY. WHILE I FEEL THAT NAM BRING TOO MUCH MOISTURE IN VICINITY OF SURFACE LOW FRIDAY (UPPER 60 DEWPOINTS)...SOME MOISTURE CONVERGENCE AND UPPER FORCING MAY GENERATE PRECIP...ESPECIALLY ACROSS SOUTHERN INDIANA...FRIDAY INTO SATURDAY MORNING. GFS IS WEAKER AND FARTHER NORTH WITH THE UPPER AIR FEATURE...CONFINING PRECIP ACROSS THE SOUTHERN GREAT LAKES. WITH SPEED OF UPPER AIR FEATURE...ANY CLOUDS OR ASSOCIATE PRECIP SHOULD EXIT AREA BY LATE SATURDAY MORNING. JSD .IN THE EXTENDED (SATURDAY THROUGH WEDNESDAY)... IN RESPONSE TO STRONG RIDGING ACROSS THE EASTERN PACIFIC...UPPER AIR PATTERN ACROSS THE ENTIRE CONUS EXPECTED TO AMPLIFY QUITE A BIT BEGINNING SATURDAY. IN AGREEMENT WITH HPC...WENT WITH ECWMF IN DEVELOPING UNSEASONABLY DEEP TROUGH ACROSS THE WESTERN STATES. ADDITIONAL JET ENERGY MOVING SOUTH INTO TROUGH WILL MAINTAIN IT ACROSS THE WESTERN STATES THROUGH WEDNESDAY. CONVERSELY...HIGH AMPLITUDE RIDGE WILL DEVELOP ACROSS THE EASTERN CONUS...ACTUALLY CENTERING ACROSS THE LOWER OHIO VALLEY BY MONDAY. WITH SUCH A STRONG RIDGE IN PLACE EXPECT DRY WEATHER WITH DISTINCTLY WARMER THAN NORMAL TEMPERATURES THROUGH AT LEAST WEDNESDAY. JSD && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1040 AM EDT WED SEP 7 2005 .UPDATE... SURFACE ANALYSIS SHOWS COLD FRONT FROM NORTHERN ONTARIO BACK THROUGH CENTRAL WISCONSIN...JUST PUSHING INTO NORTHERN LOWER. REGIONAL RADAR CONTINUES TO SHOW CONVECTION ALONG THE FRONT...MAINLY ACROSS NORTHERN LAKE MICHIGAN/NORTHERN LOWER BUT DEVELOPING BACK ACROSS WISCONSIN. VIS SATELLITE SHOWS AN AREA OF MID CLOUDS STILL PROGRESSING ACROSS SOUTHEAST MICHIGAN...ASSOCIATED WITH THE INITIAL SURGE OF 700MB THETA-E ADVECTION. CUT TEMPS BACK A COUPLE DEGREES GIVEN ADDITIONAL MORNING CLOUDS/SPRINKLES LIMITING INSOLATION. HOWEVER WITH DEWPOINTS ALREADY BEGINNING TO POOL IN THE LOW 60S WE SHOULD STILL BE ABLE TO REALIZE UP TO 1500 J/KG MIXED LAYER CAPE TODAY. SYNOPTIC SUPPORT FOR CONVECTION REMAINS WEAK WELL SOUTH OF THE UPPER LOW...WITH A RELATIVELY WEAK WIND FIELD AS WELL. CURRENT HWO FEATURE STRONG BUT NOT SEVERE STORMS STILL LOOKS GOOD. UPDATED TO ADJUST THE WEATHER TIMING THOUGH...BASED ON UPSTREAM TRENDS NOTED ALONG THE COLD FRONT AND SLOWER 12Z RUC/NAM SPEEDS BRINGING CONVECTION INTO SOUTHEAST MICHIGAN. 12Z RUN CONTINUES TO SHOW AN MCV FROM SOUTHERN MINNESOTA SWINGING ACROSS LOWER MICHIGAN OVERNIGHT...REINVIGORATING CONVECTION ALONG THE FRONT. CURRENT FORECAST HAS HIGHER POPS FOR TONIGHT ACROSS THE SOUTHERN CWA...WHICH SEEMS TO LINE UP WELL WITH THE NEW DATA ROLLING IN. && .AVIATION...724 AM EDT WED SEP 7 2005 AS OF THE 11Z SURFACE MAP... COLD FRONT EXTENDS FROM EASTERN UPPER MICHIGAN TO NORTHERN IOWA. THIS FRONT WILL MOVE SOUTHEAST TODAY... PASSING THROUGH MBS AROUND 19Z...THEN MAKING IT INTO DTW AROUND 03Z. OUTSIDE OF SOME PATCHY FOG EARLY THIS MORNING... CONDITIONS SHOULD REMAIN VFR AHEAD OF THIS FRONT. CONVERGENCE ALONG THE FRONTAL BOUNDARY WILL PROVIDE SOME SCATTERED THUNDERSTORMS. WILL THUS CARRY A CHANCE FOR MVFR CONDITIONS IN THUNDERSTORMS THIS AFTERNOON AND EVENING IN THE TAFS. WILL HAVE TO MONITOR THE REMNANTS OF THE CONVECTIVE COMPLEX OVER SOUTHERN MN THROUGHOUT THE DAY TO BETTER DETERMINE THUNDERSTORM POTENTIAL THIS EVENING. THIS SYSTEM MAY BE ABLE TO GENERATE STRONGER MID LEVEL VORTICITY ADVECTION THIS EVENING... THEREBY INCREASING THE CHANCES FOR THUNDERSTORMS AFTER 00Z. && .SHORT TERM...TODAY AND TONIGHT A LARGE UPPER LEVEL RIDGE AXIS THAT HAS BEEN IN PLACE ACROSS THE GREAT LAKES REGION THE LAST COUPLE OF DAYS IS BREAKING DOWN A BIT AS A STRONG UPPER LOW LIFTS ACROSS HUDSON BAY TODAY. AN ASSOCIATED COLD FRONT EXTENDS ACROSS CENTRAL UPPER MI AND INTO NEBRASKA PER 07Z SURFACE ANALYSIS. THUS FAR TONIGHT THE ONLY CONVECTION ALONG THIS BOUNDARY HAS BEEN ACROSS SD AND NE WHERE LOW LEVEL MOISTURE TRANSPORT IS STRONGER. THIS COLD FRONT WILL DROP SE ACROSS THE STATE TODAY AND TONIGHT AS HIGH PRESSURE OVER ND BUILDS ACROSS THE NORTHERN GREAT LAKES. OVERALL... THE 00Z MODEL SUITE ARE IN GOOD AGREEMENT WITH THE TIMING OF THIS FRONTAL BOUNDARY THROUGH THE SHORT TERM. THE FRONT IS EXPECTED TO MOVE ACROSS THE SAGINAW VALLEY BETWEEN 18Z AND 21Z THIS AFTERNOON...THEN GRADUALLY SINK SOUTH INTO THE DETROIT AREA OVERNIGHT. THERE WILL BE SOME MODEST BOUNDARY LAYER CONVERGENCE ASSOCIATED WITH THIS FRONT. WEAK SHORT WAVE TROUGHS NOTED UPSTREAM SHOULD ACCOMPANY THE MODEST MID LEVEL HEIGHT FALLS THIS AFTERNOON AND TONIGHT. THERE IS ALSO SOME WEAK UPPER DIVERGENCE/DIFLUENCE EXPECTED. THE 00Z UPPER AIR PLOTS SHOWED A NARROW AXIS OF MOISTURE NEAR 850MB... WITH DEWPOINTS OF 10 TO 14C... ALONG THE FRONTAL BOUNDARY. SURFACE DEWPOINTS HAVE ALSO POOLED INTO THE LOWER 60S ALONG THE BOUNDARY. THIS NARROW AXIS OF MOISTURE WILL WORK ITS WAY SOUTH INTO THE FORECAST AREA THIS AFTERNOON AND TONIGHT ALONG THE FRONT. MODIFIED NAM MODEL SOUNDINGS INDICATE THE POTENTIAL FOR 0-1KM MIXED LAYER CAPE TO RANGE FROM 1000 TO 1500 J/KG ALONG AND AHEAD OF THE FRONT THIS AFTERNOON AND EVENING. BASED ON THIS... WILL MAINTAIN SCATTERED TO CHANCE POPS FOR SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND TONIGHT. LIMITING FACTORS FOR MORE WIDESPREAD COVERAGE IS THE RATHER WEAK SYNOPTIC LIFT...MODEST INSTABILITY AND LACK OF SUFFICIENT MOISTURE BELOW 900MB. DESPITE UNIDIRECTIONAL MID LEVEL WIND FIELDS... 0-6KM BULK SHEAR OF ONLY 15-20KTS AND MODEST INSTABILITY DOES NOT WARRANT A MENTION OF SEVERE WEATHER. DESPITE DIMINISHING INSTABILITY TONIGHT... WILL MAINTAIN A CHANCE OF CONVECTION WITH THE FRONTAL BOUNDARY SLOWLY WORKING SOUTH THROUGH THE AREA. MID LEVEL LAPSE RATES ARE ALSO EXPECTED TO BE AROUND 6C/KM ATOP THE 850MB MOIST AXIS. SO THERE WILL BE THE POTENTIAL FOR SOME ELEVATED CONVECTION. && .LONG TERM...THURSDAY THROUGH TUESDAY... WEAK FRONTAL BOUNDARY WILL BE DRAPED NEAR THE STATE LINE WITH HIGH PRESSURE ALREADY CENTERED OVER THE NORTHERN GREAT LAKES BY THURSDAY MORNING. WILL LEAVE LOW CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS IN FOR THURSDAY MORNING SOUTH OF ABOUT I-94 WITH SHOWALTER INDEX OF -1.5C. DRY AIR WORKING SOUTH INTO THE AREA WITH SURFACE DEWPOINTS DROPPING BACK INTO THE LOW TO MID 50S SHOULD LIMIT THUNDERSTORM RE-DEVELOPMENT TO SOUTH OF THE STATE LINE BY THURSDAY AFTERNOON. OUR ATTENTION RETURNS TO THIS MOISTURE AXIS BY THURSDAY NIGHT AS A WAVE DEVELOPS ALONG WARM FRONT OVER NORTHERN ILLINOIS AND NORTHWEST INDIANA. 30 KNOT LOW LEVEL JET DEVELOPS OVERNIGHT WITH MODELS INDICATING A POSSIBLE MCS FORMING NEAR SOUTHERN LAKE MICHIGAN AND NORTHWEST INDIANA. 00Z/07 NAM/GFS/LOCAL WRFXX ARE IN GOOD AGREEMENT IN REGARDS TO MCS CHANCES LATE THURSDAY NIGHT INTO FRIDAY MORNING. 00Z AND 12Z RUNS OVER THE PAST 24 HOURS HAVE BEEN SHOWING SIGNS OF AN MCS DEVELOPING SOMEWHERE IN THE REGION...BUT THIS IS THE FIRST CYCLE WHERE MODELS HAVE COME INTO GOOD AGREEMENT ABOUT LOCATION. LOCAL WRFXX MODEL IS VERY SIMILAR TO NAM SHOWING MOST LIKELY TRAJECTORY ACROSS OUR SOUTHERN CWA AND SUSPECT THE MORE NORTHERN TRACK OF THE GFS MAY BE SUFFERING FROM SOME CONVECTIVE FEEDBACK OVER WISCONSIN FROM THE PREVIOUS AFTERNOON. HAVE ADDED CHANCE OF SHOWERS AND THUNDERSTORMS TO OUR SOUTHERN COUNTIES THURSDAY NIGHT AND FRIDAY MORNING. WILL NOT HIT TOO HARD AT THIS TIME WITH LOW LEVEL JET NOT TOO IMPRESSIVE AND SOME LINGERING QUESTION ABOUT TRACK. IF MCS DEVELOPS WE COULD EXPERIENCE SOME LOCALLY HEAVY RAINFALL AND WILL MONITOR MODEL TRENDS TODAY FOR A GREATER THREAT. BY THIS WEEKEND THE UPPER LEVEL PATTERN WILL BECOME MUCH MORE AMPLIFIED WITH A BROAD UPPER LEVEL TROUGH IN PLACE OVER THE WESTERN UNITED STATES. UPPER LEVEL RIDGE WILL BUILD EAST OVER THE GREAT LAKES REGION WITH 500MB HEIGHTS CLIMBING TO 5920M ACROSS SOUTHERN MICHIGAN. TEMPS BY SUNDAY WILL REACH THE LOW TO MID 80S...A GOOD TEN DEGREES ABOVE NORMAL. THESE ABOVE NORMAL TEMPERATURES WILL CONTINUE INTO EARLY NEXT WEEK AS WAVES EJECTING OUT OF THE WESTERN TROUGH ARE FORCED NORTH INTO CANADA AROUND THE RIDGE. A WEAK FRONT WILL BRUSH LAKE HURON SUNDAY NIGHT BUT IS NOT EXPECTED TO MAKE IT SOUTH INTO THE STATE. HAVE GONE ABOVE MEX GUIDANCE TOWARDS THE END OF THE PERIOD AS IT TYPICALLY TRENDS TOWARDS CLIMO AND DO NOT FORESEE ANYTHING TO BREAK THE HEAT THROUGH MID-WEEK. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ UPDATE...BRAVENDER SHORT TERM/AVIATION...CONSIDINE LONG TERM...KAHL mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 945 AM CDT WED SEP 7 2005 .UPDATE...12Z SOUNDINGS AND GOES SOUNDER DATA SHOW LOWER PWATS HAVE ADVECTED INTO THE CWA WITH A NORTHEAST FLOW ON THE WESTERN FLANK OF A TUTT CYCLONE OVER THE WESTERN GLFMEX. THIS IS EXPECTED TO PREVAIL MUCH OF TODAY PER THE FAVORED RUC WHICH IS PORTRAYING THE LOWER PWATS THE BEST. DYNAMICAL FORCING LARGELY REMAINS OVER THE WATERS WITH THE BEST BOUNDARY LAYER FORCING CONFINED TO THE FAR SOUTHEASTERN PORTIONS OF THE CWA. A NORTHEAST SURFACE FLOW IS ALSO TYPICALLY LESS FAVORABLE FOR CONVERGENCE. WILL LOWER POPS TO SLIGHT CHANCE AND CONFINE LOW-END CHANCE POPS TO THE FAR SOUTHEASTERN CWA. WILL INCREASE WIND SPEEDS OR EXPAND THE RANGE(ESPECIALLY THE COASTAL COUNTIES) AS DEEPENING BOUNDARY LAYER WILL TAP INTO STRONGER WINDS IN THE LOWER TROPOSPHERE PER THE CRP VWP. WILL ALSO BE A LITTLE LESS PESSIMISTIC WITH CLOUD COVER. TEMPERATURES LOOK OKAY. && .MARINE...DYNAMICAL FORCING CIRCULATING AROUND THE WESTERN GLFMEX TUTT CYCLONE WILL BE SUFFICIENT TO PRODUCE SCATTERED CONVECTION ACROSS THE NEARSHORE/OFFSHORE WATERS WITH SOME BLEEDOVER INTO THE SOUTHERN BAYS. WILL MAINTAIN SCEC BAYS/NEARSHORE WATERS AND SCA OFFSHORE WATERS BUT INCREASE SEAS SOME AS SURFACE PRESSURE GRADIENT AND MIXING REMAIN FAVORABLE. COASTAL HAZARD MESSAGE FOR MINOR TIDAL OVERFLOW DURING THE TIMES OF HIGH TIDE REMAINS VALID. && .AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH THE DAY WITH ISOLATED CONVECTION PRODUCING A BRIEF PERIOD OF MVFR/IFR CONDITIONS ...MAINLY ALI TO CRP. && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SCA GMZ270-275. && $$ 85/UPDATE tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 234 PM MDT WED SEP 7 2005 .SHORT TERM... (TONIGHT AND THURSDAY) METEOROLOGICAL CONCERNS FOR THE SHORT TERM MAINLY FOCUS ON THE POSSIBILITY OF LOCALLY HEAVY RAINFALL. LATEST WATER VAPOR IMAGERY CONTINUES TO INDICATE THAT MOISTURE PLUME STILL REMAINS IN VICINITY OF CWFA...ESPECIALLY POINTS TO OUR SOUTH AND SOUTHEAST. ALSO...LATEST PRECIPITABLE WATER VALUES HOVERING AROUND 150 PERCENT OF NORMAL AND EXPECTED TO REMAIN THAT WAY TONIGHT INTO THURSDAY. LATEST RUC40 INDICATED SOME QG ASCENT EXPECTED OVER PORTIONS OF THE CWFA THIS EVENING. THEREFORE...IN THE IMPENDING GRIDS/ZONES I HAVE INSERTED SOME LOCALLY HEAVY RAIN WORDING FROM LATE THIS AFTERNOON INTO TONIGHT. MILD TO WARM EARLY SEPTEMBER MINIMUM AND MAXIMUM TEMPERATURES TO CONTINUE WITH TEMPERATURES RUNNING A FEW CATEGORIES ABOVE CLIMATOLOGICAL AVERAGES. EXPECT MINIMUM TEMPERATURES TONIGHT AND MAXIMUM TEMPERATURES ON THURSDAY TO RUN SLIGHTLY WARMER THAN VALUES NOTED PREVIOUS 24 HOURS MOST AREAS. OUTSIDE OF THE STORMS...GRADIENT WINDS EXPECTED TO REMAIN WELL BEHAVED TONIGHT AND THURSDAY AS CENTER OF UPPER RIDGE PROJECTED TO IN THE VICINITY OF FAR SOUTHEAST COLORADO BY 00Z FRIDAY. .LONG TERM... (THURSDAY NIGHT THROUGH WEDNESDAY) MAIN CONCERN IS PCPN CHANCES. TEMPS THRU THE PERIOD LOOK AS THOUGH THEY WL BE ABOVE NORMAL. THU NIGHT AND FRI THE PLUME OF MOISTURE WILL CONTINUE TO STREAM OVR THE FORECAST AREA AS AN UPR RIDGE IS CENTERED OVR NRN TX/OK AND AN UPR TROF LIES OVR NRN CA. A SHRTWV IS EXPECTED TO BE MOVING FROM SW CO INTO CENTRAL CO THU NIGHT WHICH SHOULD ALSO HELP TO KICK OFF THUNDERSTORMS...WHICH COULD CONTINUE THRU THE NIGHT...ESPECIALLY OVR THE SW AND CENTRAL MTS. FRI THE SOUTH TO SW FLOW OVR THE AREA INCREASES SO WE WL SEE SOME STRONGER WINDS. FRI NIGHT AND SAT A NEW UPR MOVES INTO THE PACIFIC NW AND THE LOW THAT WAS OVR NRN CA GETS CAUGHT UP IN THE SW FLOW AHEAD OF THIS NEW UPR LOW AND LIFTS NEWRD INTO WY. DURING THIS TIME THERE WILL STILL BE A FAIRLY STRONG GRADIENT OVR THE FORECAST AREA SO WL KEEP SOME GUSTS IN THE FORECAST MAINLY FOR THE HIGHER ELEVATIONS. SAT THE UPR RIDGE SHIFTS FARTHER E AND BECOMES MORE CENTERED OF AR. THE PLUME OF MSTR SHIFTS E AS WELL BUT CONTINUE OVR ERN CO WITH SLIGHTLY DRIER AIR OVR WRN LOCATIONS. BY SUN THE MSTR PLUME SHIFTS TO OVR THE CENTRAL PLAINS STATES WITH SOME ADDITIONAL DRYING OVR THE FORECAST AREA WITH SW FLOW ALOFT... WITH THIS PATTERN CONTINUING THRU MON. TUE AN UPR TROF SWINGS BY THE AREA BUT AT THIS TIME THE GFS KEEPS THE AIR MASS FAIRLY DRY AND IS NOT SHOWING ANY PCPN ASSOCIATED WITH THIS...BUT WL KEEP SOME POPS OVR THE MTS. WED THE UPR FLOW IS W TO SW AND IT LOOKS LIKE SOME LOW LVL UPSLOPE COULD RETURN TO THE SE PLAINS...BUT MSTR LOOKS FAIRLY LIMITED. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 300 PM EDT WED SEP 7 2005 .SHORT TERM (TONIGHT THROUGH THURSDAY AFTERNOON)... AREA OF HI PRESSURE STRETCHED ACROSS THE OHIO VALLEY...WITH LIGHT WINDS AND SCT CU FIELD ACROSS THE FORECAST AREA ATTM. CU WILL AGAIN DISSIPATE LATER THIS EVENING LEAVING A MOSTLY CLEAR SKY AND GOOD RAD COOLING INTO THE LOW 60S...SOME PATCHY FOG (VSBY 1-3 MI) WILL BE POSSIBLE ACROSS THE SOUTHERN AND WESTERN PORTIONS OF THE AREA WHERE MORE LOW LEVEL MOISTURE IS PRESENT...MOSTLY IN THE PREFERRED AREAS AROUND LOW-LYING AREAS AND NEAR WATERWAYS/LAKES. LEANED TOWARDS THE GFS MOS FOR LOW TEMPS. TOMORROW THE COLD FRONT WILL DROP SLOWLY ACROSS IL/IN...AS THE AREA OF HIGH PRESSURE SLIDES EAST. THE MID LEVEL CAPPING WILL ERODE ACROSS THE FAR NORTHERN PORTIONS OF THE FORECAST AREA DURING THE AFTERNOON...WITH LIS NEARING -5 TO -6 AND CAPES AROUND 2000 J/KG. GFS/NAM12/48 HR RUC/AND SHRT RANGE ENSEMBLES ALL SHOW VERY LOW CHC FOR TSTMS/SHWRS...WITH THE EURO MODELS DRY. A TRIGGER WILL BE HARD TO COME BY...SO WILL ONLY PUSH POPS TO SLIGHT CHANCE ACROSS THE NORTHERN PORTION OF THE CWA...CAPPING TOO STRONG SOUTH OF THE OHIO FOR ANY POPS EVEN WITH LIS NEARING -7 AND CAPES AROUND 2200 J/KG. H850 TEMPS AND THICKNESSES INCREASE SLIGHTLY THURSDAY AFTN...WILL STAY WITH MID TO UPPER 80S ACROSS THE AREA WITH A MAV/NAM MOS BLEND. --SCHOTT .REST OF THE SHORT TERM (THURSDAY NIGHT THROUGH SATURDAY)... A COMPROMISE SOLTN BETWEEN GFS/NAM SEEMS TO BE THE BEST APPROACH ATTM TO BLEND IN WITH CURRENT FCST AND TO MESH WITH OUR NEIGHBORS. UPR LVL IMPLSES COMING OVER THE RIDGE THU NGT/FRI WITH SUBTLE LOWERING HGTS/COOLING. MODELS REVERSE THIS TREND FRI NGT/SAT INTO SUN WITH BUILDING RIDGE/MORE CAPPING. AS WASHING OUT CDFNT CONTS ITS SLOW SWD PROGRESSION THU NGT...WILL EXPAND LOW POPS (20) SWD THRU OUR FA AND CONT INTO FRI WITH ONLY WEAK UPR LVL SUPPORT BUT STEEPENING LAPSE RATES/INCREASING INSTAB. IN WAKE OF WASHED OUT FRONT...WILL PULL 20 POPS FRI NGT AS HIGH PRES RIDGE MOVES IN FROM NEW ENGLAND/MID ATLANTIC COAST. BEGINNING THE WEEKEND AND BEYOND...SEE LONG TERM DISCUSSION BELOW...MAX TEMPS WILL TOY WITH 90 DEGREES. --DK .LONG TERM (SUN THRU WED) WILL CONT WITH A DRY...A BIT WARMER THAN NORMAL FCST IN THE EXTENDED RANGE WITH AN UPR LVL RIDGE ANCHORED OVER THE SERN CONUS (MID RANGE MODEL CONSENSUS. SFC RIDGE BUILDS IN FROM NEW ENGLAND/MID ATLANTIC EARLY IN THE PD THEN SHIFTS TO THE TN VLY/NRN GULF COAST STATES BY WED. GENERALLY FOLLOWED ENSEMBLE MEAN TEMPS WITH MAXS APPROACHING 90 THRU THE PD...CONSISTENT WITH CURRENT GRIDS. DISCOUNTED THE ECMWF FCST FOR T.S. OPHELIA WITH ITS POOR TRACK RECORD WITH HANDLING OF TROPICAL SYSS. --DK && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ SCHOTT ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 430 PM EDT WED SEP 7 2005 MAIN FCST CONCERNS ARE CLOUDS/TEMPS AND PCPN CHANCES LATE FRIDAY INTO THE WEEKEND. WV IMAGERY AND RUC ANALYSIS INDICATED MAINLY ZONAL MID/UPPER LEVEL FLOW ACRS THE N CNTRL CONUS BTWN A TROF OVER HUDSON BAY AND RDGING OVER THE SRN CONUS. MAIN NRN STREAM SHRTWV/VORT AXIS EXTENDED FROM E OF JAMES BAY TO NE LK SUPERIOR. MCS OVER CNTRL INTO E WI N OF SRN WI SFC FRONTAL BNDRY WAS SUPPORTED BY A SHRTWV OVER SRN MN AND UPR LVL DIV WITH RIGHT ENTRANCE OF 95KT H25 JET N OF LK SUPERIOR. ANOTHER WEAK UPSTREAM SHRTWV WAS LOCATED OVER ND. OTHERWISE UPSTREAM SFC RDG WAS BUILDING FROM THE NRN PLAINS AND UPR MS VALLEY INTO THE NRN LAKES. VIS LOOP SHOWED EXTENSIVE MID/HIGH CLOUDS OVER UPR MI NORTH OF THE MCS. TONIGHT...RADAR LOOP INDICATES THAT NRN PORTION OF THE WI MCS MAY CLIP SRN MENOMINEE COUNTY BUT THAT THE REST OF THE AREA SHOULD REMAIN DRY. SATELLITE TRENDS AND THE NAM SUGGEST THAT MID CLOUDS WILL DEPART AS THE SHRTWV SHIFTS OFF TO THE EAST. CLEARING SKIES WILL BRING PERIOD OF FAVORABLE RADIATIONAL COOLING THAT SHOULD ALLOW TEMPS TO FALL AOB CURRENT DEWPOINTS(INTO THE LOWER 40S OVER THE W HLF OF THE CWA). HOWEVER...CLOUDS MAY INCREASE A BIT OVER THE SW LATE TONIGHT AS THE ND SHRTW MOVES TOWARD NRN WI. SO...EVEN THOUGH MIN TEMPS WERE NUDGED A BIT HIGHER...STILL CANNOT RULE OUT SOME PATCHY FROST IN FAVORED INTERERIOR LOCATIONS. THU INTO THU NIGHT...THE GFS SUGGESTS THAT THE ND SHRTWV WILL AFFECT THE SW PORTION OF THE CWA AND GENERATES SOME LIGHT PCPN. GIVEN THE RELATIVELY WEAK QVECTOR CONV WITH THIS FEATURE AND DRY AIRMASS IN PLACE...THE DRY CANADIAN/NAM PCPN WAS PREFERRED. BY LATER IN THE DAY...MDLS HINT AT POTENTIAL FOR ANOTHER MCS FROM MN INTO WI...IN BEST PROXIMITY TO LOW LVL THETA-E RDG. LATE FRI INTO FRI NIGHT...PATTERN AMPLIFIES WITH HGT FALLS OVER THE WEST AND RDG BUILDING FROM THE PLAINS TOWARD THE WRN LAKES. GFS/NAM GENERATE SOME PCPN WITH WAA PATTERN WITH ZONE OF WAA WITH THE 850-700 WARM FRONT. ONLY SLGT CHANCE POPS WERE MENTIONED AS NET ISENTROPIC LIFT AND MOISTURE AVAILABILITY REMAIN MARGINAL FOR MORE SIGNFICANT PCPN. SAT-WED...12Z GFS TREND TOWARD A STRONGER RDG AND SLOWER PROGRESSION WITH FRONTAL BOUNDARIES NOT SAGGING AS FAR S INTO THE WRN LAKES WAS PREFERRED GIVEN DOMINANT ERN RDG AND SUPPORT FROM OTHER GLBL MDLS. SO...TEMPS WERE KEPT ABV GUIDANCE THROUGH MON...WITH H8 TEMPS CLIMBING TO NEAR 19C. LOWER END (20/30 POPS) SHRA/TSRA CHANCES REMAIN AS THE FRONT MOVES NEAR UPR MI SUN AND LINGERS INTO MON. HOWEVER WITH MID LVL RDG OVER THE AREA...CAPPING WILL BE DIFFICULT TO OVERCOME. PCPN CHANCES INCREASE BY TUE AND LINGER INTO WED AS THE SFC FRONTAL BOUNDARY EDGES INTO THE AREA AS DECENT MOISTURE ADVECTION AND SW MID/UPR LVL WILL LIKELY BRING A SERIES OF SHRTWVS FROM THE PLAINS TOWARD THE WRN LAKES. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 402 PM EDT WED SEP 7 2005 .SHORT TERM...TONIGHT AND THURSDAY SURFACE ANALYSIS SHOWS THE COLD FRONT EXTENDING FROM NORTHERN ONTARIO THROUGH SOUTHERN WISCONSIN...ACROSS LAKE HURON AND CENTRAL LOWER MICHIGAN. THE FRONT IS ORIENTED NEARLY PARALLEL TO THE UPPER FLOW...AND HAS MADE A VERY SLOW PROGRESS SOUTHWARD. REGIONAL RADARS SHOW CONVECTION CONTINUING TO FIRE ALONG THE FRONT...BECOMING MORE ENHANCED BOTH DIURNALLY AND WITH SUPPORT OF A CONVECTIVE VORT TRACKING THROUGH WISCONSIN. DECENT INSTABILITY GREATER THAN 1000J/KG PRESENT WITH TEMPS IN THE MID/UPPER 80S AND DEWPOINTS POOLED INTO THE LOW/MID 60S ALONG THE FRONT...ALTHOUGH STILL LIMITED BY MARGINAL MID-LEVEL LAPSE RATES. WIND PROFILE IS ALSO SOMEWHAT WEAK...NOT VERY SUPPORTIVE OF SEVERE ORGANIZATION. EXPECT STORMS THIS EVENING TO CONTINUE TO PERCOLATE AHEAD OF THE FRONT...WITH THE STRONGER AND MORE ORGANIZED STORMS FARTHER UPSTREAM. GIVEN THE SLOW SOUTHWARD SPEED OF THE FRONT AND TIMING/ORIENTATION OF THE UPPER LEVEL SUPPORT...WILL KEEP MENTION OF STRONG STORMS IN THE HWO FOR NOW. IN ADDITIONAL WITH STORMS POPPING AHEAD OF THE FRONT...WILL START SCATTERED/CHANCE POPS OUT FROM THE START RATHER THAN ATTEMPT TO TIME THE ONSET. ADJUSTED POP WORDING/TIMING GIVEN THE SLOWER FRONTAL SPEED...HOLDING ONTO CHANCE LONGER OVERNIGHT. ELEVATED INSTABILITY WILL STILL BE PRESENT OVERNIGHT AND INTO THURSDAY MORNING...AND KEPT CHANCE POPS THROUGH THURSDAY MORNING THROUGH THE SOUTHERN CWA. WITH THE FRONT DROPPING THROUGH THE CWA TONIGHT AND FINALLY CLEARING SOUTH ON THURSDAY...TEMPERATURES WILL BE COOLER A FAIR AMOUNT COOLER THAN TODAY...GENERALLY UPPER 70S/LOW 80S. && .LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY... THE SURFACE BOUNDARY WILL DEPART TO OUR SOUTHEAST AND HIGH PRESSURE WILL BE IN PLACE ACROSS SE MICHIGAN FOR THURSDAY NIGHT AND FRIDAY...MAKING FOR A PLEASANT DAY ON FRIDAY WITH TEMPS NEAR NORMAL. SATURDAY LOOKS TO BE A TAD ABOVE NORMAL WITH SOME CONVECTIVE HIGH CLOUD DEBRIS AROUND. UNSEASONABLY STRONG UPPER RIDGING WILL BUILD IN FROM THE WEST THIS WEEKEND AND SET UP SHOP THROUGH THE EARLY PART OF NEXT WEEK. AS A RESULT...WE CAN EXPECT TEMPS WELL ABOVE AVERAGE SUNDAY THROUGH TUESDAY. MODELS SHOW 850MB TEMPERATURE ADVECTION AS HIGH AS 19C DURING THE DAY ON SUNDAY. GIVEN THE EXPECTATION OF MOSTLY SUNNY DAYS...DECIDED TO BUMP TEMPS UP A FEW DEGREES SUNDAY THROUGH TUESDAY. SUNDAY WILL GIVE US A REALISTIC SHOT AT APPROACHING THE 90 DEGREE MARK. OTHERWISE...ONLY OTHER CHANGE MADE TO THE EXTENDED FORECAST WAS TO REMOVE POPS FOR EARLY FRIDAY MORNING FOR OUR SOUTHERN COUNTIES. WRFXX KEEPS ENOUGH ENERGY AROUND IN THE SOUTH ALONG LINGERING FRONTAL BOUNDARY TO SUPPORT PRECIP...BUT WILL FOLLOW THE GFS WHICH SHOWS A POCKET OF CONSIDERABLE DRY AIR OVER OUR CWA THURSDAY NIGHT. THE SURFACE HIGH WHICH CURRENTLY RESIDES OVER NORTHERN MINNESOTA WILL ROTATE CLOCKWISE AROUND MICHIGAN UNTIL BECOMING VERTICALLY ALIGNED WITH THE UPPER HIGH OVER THE TENNESSEE VALLEY ON MONDAY. THIS SAME UPPER HIGH...ALREADY WELL ESTABLISHED TO OUR SOUTH BY THEN...WILL EXTEND A RIDGE NORTH THROUGH THE GREAT LAKES AND WELL INTO CANADA SATURDAY NIGHT AND SUNDAY. THIS RIDGING WILL BE STRONG ENOUGH TO DEFLECT THE NEXT WAVE MOVING OUT OF THE NORTHERN ROCKIES OFF TO THE NORTHEAST AND ACROSS JAMES BAY ON SUNDAY. THIS WILL KEEP THE MAIN ENERGY...ASSOCIATED WITH THIS FAIRLY POTENT WAVE...NORTH OF THE STATE. AN ASSOCIATED WEAK WARM FRONT WILL TRY TO PUSH NORTHEAST INTO MICHIGAN ON SATURDAY...HOWEVER AT THIS TIME SUSPECT THAT THE RIDGE WILL BE TOO STRONG AND THE AIRMASS TOO DRY TO SUPPORT ANY ACTIVITY WITH THIS FEATURE. AN ASSOCIATED WEAK COLD FRONT WITH THIS SAME SYSTEM WILL ATTEMPT TO SLIDE SOUTHEAST THROUGH LOWER MICHIGAN ON MONDAY. BUT GIVEN THE STRENGTH OF THE RIDGING...594 DM ALL THE WAY INTO SE MICHIGAN...AND THE AMOUNT OF DRY AIR IN PLACE...THE FRONTAL PASSAGE WILL LIKELY BE DRY. THUS...WILL CONTINUE THE DRY FORECAST WITH THIS SURFACE FEATURE AS WELL. A SURFACE HIGH WILL FOLLOW ON THE HEELS OF THE UPPER WAVE MOVING ACROSS CANADA AND WILL EVENTUALLY MERGE WITH THE BEFORE MENTIONED SURFACE HIGH OVER THE TENNESSEE VALLEY TO EXTEND A BROAD AREA OF SURFACE HIGH PRESSURE ACROSS THE EASTERN CONUS ON TUESDAY. THE MAJORITY OF THE MODELS SHOW OPHELIA STILL LINGERING OFF THE COAST OF SOUTH CAROLINA DURING THIS TIME. OF PARTICULAR NOTE...THE LOCAL WRFXX TAKES OPHELIA AROUND THE SOUTHERN PERIPHERY OF THE RIDGE WHICH TAKES IT ACROSS THE NORTHERN PENINSULA OF FLORIDA ON SATURDAY. IT THEN SHOWS OPHELIA MOVING WEST ACROSS THE NORTHERN GULF BEFORE TURNING NORTHWEST INTO SOUTHEAST LOUISIANA ON MONDAY. THE REASON I BRING THIS UP...ALTHOUGH AN OUTLIER AT THIS POINT...THIS TYPE OF A SCENARIO WOULD BRING REMNANT MOISTURE RIGHT ACROSS OUR AREA AROUND THE WEDNESDAY TIMEFRAME. A STRONG COLD FRONT WILL ALSO BE PRESSING DOWN UPON US ON WEDNESDAY...BUT BOTH THE GFS AND DGEX SHOW A FRONTAL PASSAGE THROUGH SE MICHIGAN DURING THE WEDNESDAY NIGHT/THURSDAY TIMEFRAME. DUE TO THESE MULTIPLE VARIABLES NOT ENOUGH CONFIDENCE EXISTS AT THIS TIME TO INTRODUCE ANY PRECIP ON WEDNESDAY. && .AVIATION...ISSUED AT 135 PM COLD FRONT MAKING A SLOW PROGRESS SOUTHWARD ACROSS NORTHERN LOWER. REGIONAL RADARS SHOW CONVECTION CONTINUES TO DEVELOP ACROSS NORTHERN LAKE MICHIGAN AND TRACK THROUGH NORTHERN LOWER. LINEAR EXTRAPOLATION OF THE SOUTHWARD SPEED AGREES WITH THE 15Z RUC FORECAST...BRINGING IT INTO THE SAGINAW VALLEY EARLY THIS EVENING. BUMPED PRECIP TIMING BACK IN ALL THE TAFS GIVEN THE SLOWER FRONTAL SPEED. HOWEVER BROUGHT A TEMPO GROUP IN A BIT EARLIER THAN WOULD BE INDICATED FOR MBS GIVEN THE ADDITIONAL STORMS THAT HAVE BEEN BUBBLING AHEAD OF THE MAIN FRONT. EARLY MORNING MCS ACTIVITY OVER SOUTHERN MINNESOTA HAS SPREAD NORTHEASTWARD ALONG THE FRONT INTO CENTRAL WISCONSIN. GFS DEVELOPS SOME BIG FEEDBACK ISSUES WITH THIS SYSTEM...BUT SEEMS REASONABLE WITH THE OVERALL IDEA OF TAKING AN MCV THROUGH LOWER MICHIGAN TONIGHT. COULD SEE ACTIVITY FILL IN ALONG THE FRONT. THERE HAS BEEN A NORTHWARD TREND FOR THE OVERNIGHT CONVECTION...WHICH CERTAINLY SEEMS REASONABLE GIVEN THE UPSTREAM ACTIVITY. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ SHORT TERM/AVIATION...BRAVENDER LONG TERM....SHULER mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 135 PM EDT WED SEP 7 2005 .AVIATION... COLD FRONT MAKING A SLOW PROGRESS SOUTHWARD ACROSS NORTHERN LOWER. REGIONAL RADARS SHOW CONVECTION CONTINUES TO DEVELOP ACROSS NORTHERN LAKE MICHIGAN AND TRACK THROUGH NORTHERN LOWER. LINEAR EXTRAPOLATION OF THE SOUTHWARD SPEED AGREES WITH THE 15Z RUC FORECAST...BRINGING IT INTO THE SAGINAW VALLEY EARLY THIS EVENING. BUMPED PRECIP TIMING BACK IN ALL THE TAFS GIVEN THE SLOWER FRONTAL SPEED. HOWEVER BROUGHT A TEMPO GROUP IN A BIT EARLIER THAN WOULD BE INDICATED FOR MBS GIVEN THE ADDITIONAL STORMS THAT HAVE BEEN BUBBLING AHEAD OF THE MAIN FRONT. EARLY MORNING MCS ACTIVITY OVER SOUTHERN MINNESOTA HAS SPREAD NORTHEASTWARD ALONG THE FRONT INTO CENTRAL WISCONSIN. GFS DEVELOPS SOME BIG FEEDBACK ISSUES WITH THIS SYSTEM...BUT SEEMS REASONABLE WITH THE OVERALL IDEA OF TAKING AN MCV THROUGH LOWER MICHIGAN TONIGHT. COULD SEE ACTIVITY FILL IN ALONG THE FRONT. THERE HAS BEEN A NORTHWARD TREND FOR THE OVERNIGHT CONVECTION...WHICH CERTAINLY SEEMS REASONABLE GIVEN THE UPSTREAM ACTIVITY. && .UPDATE...1040 AM EDT WED SEP 7 2005 SURFACE ANALYSIS SHOWS COLD FRONT FROM NORTHERN ONTARIO BACK THROUGH CENTRAL WISCONSIN...JUST PUSHING INTO NORTHERN LOWER. REGIONAL RADAR CONTINUES TO SHOW CONVECTION ALONG THE FRONT...MAINLY ACROSS NORTHERN LAKE MICHIGAN/NORTHERN LOWER BUT DEVELOPING BACK ACROSS WISCONSIN. VIS SATELLITE SHOWS AN AREA OF MID CLOUDS STILL PROGRESSING ACROSS SOUTHEAST MICHIGAN...ASSOCIATED WITH THE INITIAL SURGE OF 700MB THETA-E ADVECTION. CUT TEMPS BACK A COUPLE DEGREES GIVEN ADDITIONAL MORNING CLOUDS/SPRINKLES LIMITING INSOLATION. HOWEVER WITH DEWPOINTS ALREADY BEGINNING TO POOL IN THE LOW 60S WE SHOULD STILL BE ABLE TO REALIZE UP TO 1500 J/KG MIXED LAYER CAPE TODAY. SYNOPTIC SUPPORT FOR CONVECTION REMAINS WEAK WELL SOUTH OF THE UPPER LOW...WITH A RELATIVELY WEAK WIND FIELD AS WELL. CURRENT HWO FEATURE STRONG BUT NOT SEVERE STORMS STILL LOOKS GOOD. UPDATED TO ADJUST THE WEATHER TIMING THOUGH...BASED ON UPSTREAM TRENDS NOTED ALONG THE COLD FRONT AND SLOWER 12Z RUC/NAM SPEEDS BRINGING CONVECTION INTO SOUTHEAST MICHIGAN. 12Z RUN CONTINUES TO SHOW AN MCV FROM SOUTHERN MINNESOTA SWINGING ACROSS LOWER MICHIGAN OVERNIGHT...REINVIGORATING CONVECTION ALONG THE FRONT. CURRENT FORECAST HAS HIGHER POPS FOR TONIGHT ACROSS THE SOUTHERN CWA...WHICH SEEMS TO LINE UP WELL WITH THE NEW DATA ROLLING IN. && .SHORT TERM...TODAY AND TONIGHT A LARGE UPPER LEVEL RIDGE AXIS THAT HAS BEEN IN PLACE ACROSS THE GREAT LAKES REGION THE LAST COUPLE OF DAYS IS BREAKING DOWN A BIT AS A STRONG UPPER LOW LIFTS ACROSS HUDSON BAY TODAY. AN ASSOCIATED COLD FRONT EXTENDS ACROSS CENTRAL UPPER MI AND INTO NEBRASKA PER 07Z SURFACE ANALYSIS. THUS FAR TONIGHT THE ONLY CONVECTION ALONG THIS BOUNDARY HAS BEEN ACROSS SD AND NE WHERE LOW LEVEL MOISTURE TRANSPORT IS STRONGER. THIS COLD FRONT WILL DROP SE ACROSS THE STATE TODAY AND TONIGHT AS HIGH PRESSURE OVER ND BUILDS ACROSS THE NORTHERN GREAT LAKES. OVERALL... THE 00Z MODEL SUITE ARE IN GOOD AGREEMENT WITH THE TIMING OF THIS FRONTAL BOUNDARY THROUGH THE SHORT TERM. THE FRONT IS EXPECTED TO MOVE ACROSS THE SAGINAW VALLEY BETWEEN 18Z AND 21Z THIS AFTERNOON...THEN GRADUALLY SINK SOUTH INTO THE DETROIT AREA OVERNIGHT. THERE WILL BE SOME MODEST BOUNDARY LAYER CONVERGENCE ASSOCIATED WITH THIS FRONT. WEAK SHORT WAVE TROUGHS NOTED UPSTREAM SHOULD ACCOMPANY THE MODEST MID LEVEL HEIGHT FALLS THIS AFTERNOON AND TONIGHT. THERE IS ALSO SOME WEAK UPPER DIVERGENCE/DIFLUENCE EXPECTED. THE 00Z UPPER AIR PLOTS SHOWED A NARROW AXIS OF MOISTURE NEAR 850MB... WITH DEWPOINTS OF 10 TO 14C... ALONG THE FRONTAL BOUNDARY. SURFACE DEWPOINTS HAVE ALSO POOLED INTO THE LOWER 60S ALONG THE BOUNDARY. THIS NARROW AXIS OF MOISTURE WILL WORK ITS WAY SOUTH INTO THE FORECAST AREA THIS AFTERNOON AND TONIGHT ALONG THE FRONT. MODIFIED NAM MODEL SOUNDINGS INDICATE THE POTENTIAL FOR 0-1KM MIXED LAYER CAPE TO RANGE FROM 1000 TO 1500 J/KG ALONG AND AHEAD OF THE FRONT THIS AFTERNOON AND EVENING. BASED ON THIS... WILL MAINTAIN SCATTERED TO CHANCE POPS FOR SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND TONIGHT. LIMITING FACTORS FOR MORE WIDESPREAD COVERAGE IS THE RATHER WEAK SYNOPTIC LIFT...MODEST INSTABILITY AND LACK OF SUFFICIENT MOISTURE BELOW 900MB. DESPITE UNIDIRECTIONAL MID LEVEL WIND FIELDS... 0-6KM BULK SHEAR OF ONLY 15-20KTS AND MODEST INSTABILITY DOES NOT WARRANT A MENTION OF SEVERE WEATHER. DESPITE DIMINISHING INSTABILITY TONIGHT... WILL MAINTAIN A CHANCE OF CONVECTION WITH THE FRONTAL BOUNDARY SLOWLY WORKING SOUTH THROUGH THE AREA. MID LEVEL LAPSE RATES ARE ALSO EXPECTED TO BE AROUND 6C/KM ATOP THE 850MB MOIST AXIS. SO THERE WILL BE THE POTENTIAL FOR SOME ELEVATED CONVECTION. && .LONG TERM...THURSDAY THROUGH TUESDAY... WEAK FRONTAL BOUNDARY WILL BE DRAPED NEAR THE STATE LINE WITH HIGH PRESSURE ALREADY CENTERED OVER THE NORTHERN GREAT LAKES BY THURSDAY MORNING. WILL LEAVE LOW CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS IN FOR THURSDAY MORNING SOUTH OF ABOUT I-94 WITH SHOWALTER INDEX OF -1.5C. DRY AIR WORKING SOUTH INTO THE AREA WITH SURFACE DEWPOINTS DROPPING BACK INTO THE LOW TO MID 50S SHOULD LIMIT THUNDERSTORM RE-DEVELOPMENT TO SOUTH OF THE STATE LINE BY THURSDAY AFTERNOON. OUR ATTENTION RETURNS TO THIS MOISTURE AXIS BY THURSDAY NIGHT AS A WAVE DEVELOPS ALONG WARM FRONT OVER NORTHERN ILLINOIS AND NORTHWEST INDIANA. 30 KNOT LOW LEVEL JET DEVELOPS OVERNIGHT WITH MODELS INDICATING A POSSIBLE MCS FORMING NEAR SOUTHERN LAKE MICHIGAN AND NORTHWEST INDIANA. 00Z/07 NAM/GFS/LOCAL WRFXX ARE IN GOOD AGREEMENT IN REGARDS TO MCS CHANCES LATE THURSDAY NIGHT INTO FRIDAY MORNING. 00Z AND 12Z RUNS OVER THE PAST 24 HOURS HAVE BEEN SHOWING SIGNS OF AN MCS DEVELOPING SOMEWHERE IN THE REGION...BUT THIS IS THE FIRST CYCLE WHERE MODELS HAVE COME INTO GOOD AGREEMENT ABOUT LOCATION. LOCAL WRFXX MODEL IS VERY SIMILAR TO NAM SHOWING MOST LIKELY TRAJECTORY ACROSS OUR SOUTHERN CWA AND SUSPECT THE MORE NORTHERN TRACK OF THE GFS MAY BE SUFFERING FROM SOME CONVECTIVE FEEDBACK OVER WISCONSIN FROM THE PREVIOUS AFTERNOON. HAVE ADDED CHANCE OF SHOWERS AND THUNDERSTORMS TO OUR SOUTHERN COUNTIES THURSDAY NIGHT AND FRIDAY MORNING. WILL NOT HIT TOO HARD AT THIS TIME WITH LOW LEVEL JET NOT TOO IMPRESSIVE AND SOME LINGERING QUESTION ABOUT TRACK. IF MCS DEVELOPS WE COULD EXPERIENCE SOME LOCALLY HEAVY RAINFALL AND WILL MONITOR MODEL TRENDS TODAY FOR A GREATER THREAT. BY THIS WEEKEND THE UPPER LEVEL PATTERN WILL BECOME MUCH MORE AMPLIFIED WITH A BROAD UPPER LEVEL TROUGH IN PLACE OVER THE WESTERN UNITED STATES. UPPER LEVEL RIDGE WILL BUILD EAST OVER THE GREAT LAKES REGION WITH 500MB HEIGHTS CLIMBING TO 5920M ACROSS SOUTHERN MICHIGAN. TEMPS BY SUNDAY WILL REACH THE LOW TO MID 80S...A GOOD TEN DEGREES ABOVE NORMAL. THESE ABOVE NORMAL TEMPERATURES WILL CONTINUE INTO EARLY NEXT WEEK AS WAVES EJECTING OUT OF THE WESTERN TROUGH ARE FORCED NORTH INTO CANADA AROUND THE RIDGE. A WEAK FRONT WILL BRUSH LAKE HURON SUNDAY NIGHT BUT IS NOT EXPECTED TO MAKE IT SOUTH INTO THE STATE. HAVE GONE ABOVE MEX GUIDANCE TOWARDS THE END OF THE PERIOD AS IT TYPICALLY TRENDS TOWARDS CLIMO AND DO NOT FORESEE ANYTHING TO BREAK THE HEAT THROUGH MID-WEEK. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....BRAVENDER UPDATE.......BRAVENDER SHORT TERM...CONSIDINE LONG TERM....KAHL mi AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 250 PM MDT WED SEP 7 2005 .DISCUSSION...CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER EAST CENTRAL WY WITH WEAK FRONTAL BOUNDARY STRETCHING ACROSS THE BLACK HILLS AREA INTO NORTHERN NEB. DEWPOINTS EAST OF THE BOUNDARY ARE CREEPING UP THRU THE 50S AND INTO THE LOWER 60S. LOW CLOUDS HAVE DISSIPATED FOR THE MOST PART WITH SOME SUNSHINE ACROSS THE AREA. TEMPS NOW SURGING UP THRU THE 70S AND INTO THE LOWER 80S. UPPER LEVEL ANALYSIS SHOWS LOW OFF NORTHERN CA COAST WITH ZONAL FLOW ACROSS THE NORTHERN HIGH PLAINS. RUC AND LAPS ANALYSIS SHOWING CONVECTIVE CAP SLOWLY ERODING ACROSS THE HILLS AND NORTHEAST WY...WHERE SUN HAS BEEN SHINING FOR GOOD PART OF THE DAY. REGIONAL RADARS SHOWING STORMS FIRING FURTHER SOUTH AND WEST ACROSS THE WY AND CO MOUNTAINS THIS AFTERNOON AND MOVING INTO NEB PANHANDLE. MODELS IN DECENT AGREEMENT WITH SYNOPTIC FEATURES...BUT DIFFER SOME ON MESOSCALE SPECIFICS...AS WOULD BE EXPECTED WITH THIS TYPE OF WEATHER PATTERN. EXPECT ATMOS TO CONTINUE TO DESTABILIZE LATE THIS AFT WITH MLCAPES OF 2000+ J/KG POOLING JUST EAST OF THE HILLS. THE ONLY THING THAT APPEARS TO BE HOLDING THIS BACK FROM BEING A SIGNIFICANT SEVERE WX EVENT IS THE LACK OF STRONG UPPER LEVEL FORCING. BUT WHEN CAP ERODES LATE THIS AFTERNOON ACROSS THE BLACK HILLS AREA...IT SHOULD NOT TAKE A LOT OF LIFT TO GET AT LEAST A FEW STORMS GOING. SEVERE THREAT APPEARS TO BE MOST FAVORABLE OVER AND EAST OF THE HILLS...WHERE MOISTURE CONVERGENCE AND BETTER SHEAR WILL BE IN PLACE. WOULD EXPECT AT LEAST A STORM OR TWO TO BECOME SEVERE...WITH LARGE HAIL THE MAIN THREAT. A MILDER NIGHT IS EXPECTED WITH LOW LEVEL MOISTURE HANGING AROUND...LOWS IN THE 50S TO LOWER 60S. RIDGE WILL BUILD OVER THE PLAINS STATES THURSDAY AND FRIDAY... WARMING TEMPS BACK TO NEAR RECORD LEVELS BY FRIDAY. HIGHS SHOULD BE NEAR 100 EAST OF THE HILLS ON FRIDAY. THIS SHOULD HELP NEGATE THUNDERSTORM DEVELOPMENT FOR THE MOST PART...BUT WILL INCLUDE SOME VERY LOW CHANCES THU AFT AND NIGHT ACROSS WESTERN SD AS LOW LEVEL SOUTHERLY JET CRANKS UP. AS RIDGE SHIFTS EAST LATE FRIDAY AND SATURDAY...UPPER FLOW WILL TURN SOUTHWESTERLY OVER THE ROCKIES AND HIGH PLAINS. COLD FRONT IS EXPECTED TO CROSS THE AREA SOMETIME ON SATURDAY...TIMING IS STILL A BIT UNCERTAIN. WITH SOUTHWEST FLOW AND FRONT IN THE AREA...WILL KEEP AT LEAST SOME LOW CHANCES FOR SHOWERS AND STORMS FRIDAY NIGHT THRU SATURDAY NIGHT. .EXTENDED...UPPER LEVEL TROUGH OVER THE WESTERN UNITED STATES WILL PRODUCE SOUTHWEST FLOW OVER THE NORTHERN PLAINS THROUGH MOST OF THE EXTENDED FORECAST. A SERIES OF SHORTWAVES WILL BE EJECTED OUT OF THE TROUGH AND PROGRESS ACROSS THE FORECAST AREA DURING THE PERIOD. TIMING AND PLACEMENT OF THESE SHORTWAVES IS TRICKY...THEREFORE HAVE NOT CHANGED CURRENT BROADBRUSHED POPS. LATEST MODELS TRYING TO PROGRESS UPPER TROUGH OVER THE AREA BY MIDDLE OF NEXT WEEK. IF THIS PLAYS OUT...COOLER TEMPS AND A CONTINUED CHANCE OF PRECIP WOULD BE THE RESULT. HAVE BUMPED TEMPS DOWN A FEW DEGREES DURING THAT TIME PERIOD. && .AVIATION...THERE WILL BE SOME LOCAL MVFR CONDITIONS WITH GUSTY WINDS THROUGH THURSDAY MORNING IN THE VICINITY OF THUNDERSTORMS...OTHERWISE VFR CONDITIONS ARE EXPECTED. ISOLATED THUNDERSTORMS MAY AFFECT PORTIONS OF ALL TWEB ROUTES THROUGH THE FORECAST PERIOD...WITH TWEB ROUTE 258 EXPERIENCING SLIGHTLY MORE COVERAGE WITH SCATTERED THUNDERSTORMS. && .UNR...WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ sd