Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/21/15


AREA FORECAST DISCUSSION
NWS TUCSON AZ
938 AM MST WED AUG 19 2015 .SYNOPSIS...EXPECT ISOLATED THUNDERSTORMS NEAR THE INTERNATIONAL BORDER SOUTHEAST OF TUCSON THIS AFTERNOON AND EVENING...AND ISOLATED THUNDERSTORMS FROM TUCSON EAST AND SOUTH THURSDAY. SIGNIFICANTLY GREATER CHANCES FOR SHOWERS AND THUNDERSTORMS WILL THEN OCCUR FRIDAY AND CONTINUE INTO EARLY NEXT WEEK. A GRADUAL COOLING TREND WILL PREVAIL THROUGH FRIDAY FOLLOWED BY NEAR NORMAL DAYTIME TEMPERATURES THIS WEEKEND AND EARLY NEXT WEEK. && .DISCUSSION...SIMILAR WEATHER CONDITIONS AS YESTERDAY CAN BE ANTICIPATED FOR TODAY. MODELS STILL SUGGEST AN INCREASE IN THUNDERSTORM ACTIVITY RETURNING TO THE AREA FRIDAY INTO EARLY NEXT WEEK AS THE FLOW PATTERN BECOMES MORE FAVORABLE. CURRENT FORECAST LOOKED ON TRACK...SO NO UPDATES NECESSARY THIS MORNING. PLEASE REFER TO THE ADDITIONAL SECTIONS FOR MORE DETAILS. && .AVIATION...VALID THRU 20/06Z. SCT CIRRUS CLOUDS UNDER NW FLOW ALOFT OTRW CLR. AFT 19/21Z FEW-SCT 8- 10KFT WITH SLGT CHC OF TSTMS OVER MTNS WELL SE OF KTUS. LIGHT TERRAIN DRIVEN WINDS EXCEPT NW 15-20 KTS SAFFORD VALLEY. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...GENERALLY DRY CONDITIONS ARE EXPECTED WITH POSSIBLE EXCEPTION OF AN ISOLATED THUNDERSTORM FAR SOUTHERN PART OF ZONE 152 LATE TODAY. MIN RH LEVELS TODAY WILL BE THE LOWEST OF THE WEEK AND BOTTOM OUT IN THE 15-25 PERCENT RANGE ACROSS LOWER ELEVATIONS WITH A DECENT AFTERNOON BREEZE AGAIN THIS AFTERNOON. THE WIND WILL BE STRONGEST IN THE GILA VALLEY ALTHOUGH A FEW MPH LESS THAN YESTERDAY. MOISTURE WILL BEGIN TO INCREASE THURSDAY WITH ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE...MAINLY SOUTHERN AREAS. THEN THE MOISTURE AND THUNDERSTORMS CHANCES WILL INCREASE AND SPREAD THROUGHOUT SOUTHEAST ARIZONA THROUGH THE WEEKEND INTO EARLY NEXT WEEK. && .PREV DISCUSSION...NWLY FLOW ALOFT CONTINUES ACROSS SE ARIZONA EARLY THIS MORNING WITH HIGH PRESSURE CENTERED NEAR THE SOUTHERN CALIFORNIA COAST. PRECIP-FREE CONDITIONS WILL OCCUR ACROSS MUCH OF THIS FORECAST AREA THRU TONIGHT. HOWEVER...HAVE OPTED TO INTRODUCE A SLIGHT CHANCE OF SHOWERS/TSTMS THIS AFTERNOON AND EVENING ACROSS SRN PORTIONS OF COCHISE COUNTY...AND THE ERN PORTION OF SANTA CRUZ COUNTY. SEVERAL HRRR SOLUTIONS AS WELL AS THE 19/06Z NAM12 DEPICT THE BEST CHANCE FOR MEASURABLE RAINFALL TO OCCUR ACROSS THE HUACHUCA MOUNTAINS. ANY SHOWERS/TSTMS SHOULD DISSIPATE AROUND SUNSET OR SHORTLY THEREAFTER. THE UPPER HIGH IS THEN PROGGED VIA THE 19/00Z NAM/GFS/ECMWF/CMC TO WEAKEN ON THUR...AND THE NEAR-SURFACE FLOW REGIME IS PROGGED TO BECOME INCREASINGLY SLY/SELY...ESPECIALLY BY THUR NIGHT. HAVE MAINTAINED ISOLATED SHOWERS/TSMTS MAINLY FROM TUCSON EWD/SWD THUR AFTERNOON INTO THUR NIGHT. MOISTURE WILL CONTINUE TO INCREASE ACROSS THE AREA FRI AS HIGH PRESSURE ALOFT BECOMES POSITIONED OVER FAR WEST TEXAS. THUS...HAVE INCREASED POPS GENERALLY 10-20 PERCENT FRI ESPECIALLY FROM TUCSON EAST AND SOUTH VERSUS THE INHERITED FORECAST. HOWEVER POPS FOR FRI AFTERNOON/EVENING ARE STILL SOMEWHAT LOW RELATIVE TO SOME GUIDANCE SUCH AS THE GFSX/ECMX. AT ANY RATE...SCATTERED SHOWERS/TSTMS SHOULD OCCUR ACROSS MUCH OF THE AREA FRI AFTERNOON/ EVENING...WITH ISOLATED SHOWERS/TSTMS ACROSS WRN SECTIONS. SOME DECREASE IN THE COVERAGE OF SHOWERS/TSTMS IS EXPECTED SAT GIVEN THE PROGGED VERY LIGHT MID/UPPER LEVEL FLOW REGIME. THE POTENTIAL THEN EXISTS FOR A FAIRLY SIGNIFICANT INCREASE IN SHOWERS/TSTMS SUN- MON DUE TO A DEEPER SELY FLOW REGIME. THE GFS/ECMWF WERE ALSO SIMILAR WITH DEPICTING AN INVERTED TROUGH TO ENCROACH UPON FAR SERN SECTIONS SUN NIGHT/EARLY MON. AT ANY RATE...POPS WERE TRENDED UPWARD BASED ON THE 19/00Z GFS/ECMWF/CMC SOLUTIONS TO REFLECT THIS NOTION. THEREAFTER...ADEQUATE MOISTURE SUGGESTS THE CONTINUATION OF CHANCE- CATEGORY POPS ACROSS MUCH OF SE ARIZONA MON NIGHT-TUE. HIGH TEMPS TODAY WILL BE QUITE SIMILAR TO TEMPS ACHIEVED TUE...AND WILL AVERAGE ABOUT 2-6 DEGS F ABOVE NORMAL. SOME MINOR DAILY COOLING WILL THEN OCCUR THUR-FRI FOLLOWED BY NEAR NORMAL DAYTIME TEMPS FOR MUCH OF THE AREA SAT-TUE. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS TUCSON AZ
350 AM MST WED AUG 19 2015 .SYNOPSIS...EXPECT ISOLATED THUNDERSTORMS NEAR THE INTERNATIONAL BORDER SOUTHEAST OF TUCSON THIS AFTERNOON AND EVENING...AND ISOLATED THUNDERSTORMS FROM TUCSON EAST AND SOUTH THURSDAY. SIGNIFICANTLY GREATER CHANCES FOR SHOWERS AND THUNDERSTORMS WILL THEN OCCUR FRIDAY AND CONTINUE INTO EARLY NEXT WEEK. A GRADUAL COOLING TREND WILL PREVAIL THROUGH FRIDAY FOLLOWED BY NEAR NORMAL DAYTIME TEMPERATURES THIS WEEKEND AND EARLY NEXT WEEK. && .DISCUSSION...NWLY FLOW ALOFT CONTINUES ACROSS SE ARIZONA EARLY THIS MORNING WITH HIGH PRESSURE CENTERED NEAR THE SOUTHERN CALIFORNIA COAST. PRECIP-FREE CONDITIONS WILL OCCUR ACROSS MUCH OF THIS FORECAST AREA THRU TONIGHT. HOWEVER...HAVE OPTED TO INTRODUCE A SLIGHT CHANCE OF SHOWERS/TSTMS THIS AFTERNOON AND EVENING ACROSS SRN PORTIONS OF COCHISE COUNTY...AND THE ERN PORTION OF SANTA CRUZ COUNTY. SEVERAL HRRR SOLUTIONS AS WELL AS THE 19/06Z NAM12 DEPICT THE BEST CHANCE FOR MEASURABLE RAINFALL TO OCCUR ACROSS THE HUACHUCA MOUNTAINS. ANY SHOWERS/TSTMS SHOULD DISSIPATE AROUND SUNSET OR SHORTLY THEREAFTER. THE UPPER HIGH IS THEN PROGGED VIA THE 19/00Z NAM/GFS/ECMWF/CMC TO WEAKEN ON THUR...AND THE NEAR-SURFACE FLOW REGIME IS PROGGED TO BECOME INCREASINGLY SLY/SELY...ESPECIALLY BY THUR NIGHT. HAVE MAINTAINED ISOLATED SHOWERS/TSMTS MAINLY FROM TUCSON EWD/SWD THUR AFTERNOON INTO THUR NIGHT. MOISTURE WILL CONTINUE TO INCREASE ACROSS THE AREA FRI AS HIGH PRESSURE ALOFT BECOMES POSITIONED OVER FAR WEST TEXAS. THUS...HAVE INCREASED POPS GENERALLY 10-20 PERCENT FRI ESPECIALLY FROM TUCSON EAST AND SOUTH VERSUS THE INHERITED FORECAST. HOWEVER POPS FOR FRI AFTERNOON/EVENING ARE STILL SOMEWHAT LOW RELATIVE TO SOME GUIDANCE SUCH AS THE GFSX/ECMX. AT ANY RATE...SCATTERED SHOWERS/TSTMS SHOULD OCCUR ACROSS MUCH OF THE AREA FRI AFTERNOON/ EVENING...WITH ISOLATED SHOWERS/TSTMS ACROSS WRN SECTIONS. SOME DECREASE IN THE COVERAGE OF SHOWERS/TSTMS IS EXPECTED SAT GIVEN THE PROGGED VERY LIGHT MID/UPPER LEVEL FLOW REGIME. THE POTENTIAL THEN EXISTS FOR A FAIRLY SIGNIFICANT INCREASE IN SHOWERS/TSTMS SUN- MON DUE TO A DEEPER SELY FLOW REGIME. THE GFS/ECMWF WERE ALSO SIMILAR WITH DEPICTING AN INVERTED TROUGH TO ENCROACH UPON FAR SERN SECTIONS SUN NIGHT/EARLY MON. AT ANY RATE...POPS WERE TRENDED UPWARD BASED ON THE 19/00Z GFS/ECMWF/CMC SOLUTIONS TO REFLECT THIS NOTION. THEREAFTER...ADEQUATE MOISTURE SUGGESTS THE CONTINUATION OF CHANCE- CATEGORY POPS ACROSS MUCH OF SE ARIZONA MON NIGHT-TUE. HIGH TEMPS TODAY WILL BE QUITE SIMILAR TO TEMPS ACHIEVED TUE...AND WILL AVERAGE ABOUT 2-6 DEGS F ABOVE NORMAL. SOME MINOR DAILY COOLING WILL THEN OCCUR THUR-FRI FOLLOWED BY NEAR NORMAL DAYTIME TEMPS FOR MUCH OF THE AREA SAT-TUE. && .AVIATION...VALID THRU 20/00Z. SCT TO BKN CIRRUS CLOUDS UNDER NW FLOW ALOFT OTRW CLR. AFT 19/19Z FEW-SCT 8-10KFT WITH SLGT CHC OF TSTMS OVER MTNS WELL SE OF KTUS. LIGHT TERRAIN DRIVEN WINDS EXCEPT NW WIND 5-12 KTS IN THE SAFFORD VALLEY THEN AFT 19/19Z WIND BECOMING W TO NW 8-15 KTS EXCEPT 15-20 KTS SAFFORD VALLEY. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...GENERALLY DRY CONDITIONS ARE EXPECTED WITH POSSIBLE EXCEPTION OF AN ISOLATED THUNDERSTORM FAR SOUTHERN PART OF ZONE 152 LATE TODAY. MIN RH LEVELS TODAY WILL BE THE LOWEST OF THE WEEK AND BOTTOM OUT IN THE 15-25 PERCENT RANGE ACROSS LOWER ELEVATIONS WITH A DECENT AFTERNOON BREEZE AGAIN THIS AFTERNOON. THE WIND WILL BE STRONGEST IN THE GILA VALLEY ALTHOUGH A FEW MPH LESS THAN YESTERDAY. MOISTURE WILL BEGIN TO INCREASE THURSDAY WITH ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE...MAINLY SOUTHERN AREAS. THEN THE MOISTURE AND THUNDERSTORMS CHANCES WILL INCREASE AND SPREAD THROUGHOUT SOUTHEAST ARIZONA THROUGH THE WEEKEND INTO EARLY NEXT WEEK. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON DISCUSSION...FRANCIS AVIATION/FIRE WEATHER...CERNIGLIA
AREA FORECAST DISCUSSION
NWS TAUNTON MA
725 PM EDT THU AUG 20 2015 .SYNOPSIS... A SLOW MOVING FRONT WILL STALL OVER THE REGION FRIDAY INTO SATURDAY BRINGING SCATTERED SHOWERS AND THUNDERSTORMS WITH LOCALLY HEAVY RAINFALL. HUMID CONDITIONS ALONG WITH THE THREAT OF SHOWERS AND THUNDERSTORMS WILL PERSIST THROUGH TUESDAY...THEN A COLD FRONT WILL MOVE THROUGH BRINGING DRIER WEATHER FOR THE MIDDLE OF NEXT WEEK. SUBTROPICAL LOW PRESSURE MOVING NORTHWEST FROM BERMUDA WILL REMAIN WELL OUT TO SEA SUNDAY NIGHT INTO MONDAY. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... 720 PM UPDATE... STRATUS STARTING TO DEVELOP ALONG THE S COAST...AND PUSHING SOUTH ALONG THE NORTH SHORE AS LOW LEVEL MOISTURE INCREASES FROM SE FLOW. DEWPOINTS UPPER 60S AND LOWER 70S SO LOTS OF MOIST AIR AT LOW LEVELS. STRATUS WILL CONTINUE TO DEVELOP AND GRADUALLY ADVECT INLAND TONIGHT WITH AREAS OF FOG FORMING...ESPECIALLY ALONG THE COAST. THE FOG MAY BE LOCALLY DENSE IN SPOTS. MIN TEMPS SHOULD BE NEAR THE DEW POINTS...IN THE UPPER 60S AND LOWER 70S. FRONT APPROACHING THROUGH NEW YORK OVERNIGHT WILL SPREAD SHOWERS TOWARD OUR WESTERN AREAS WELL AFTER MIDNIGHT. WHILE MOST OF THE DYNAMICS LIFT NORTH INTO CANADA...LOW LEVEL CONVERGENCE ALONG THE FRONT WILL YIELD STRONG MID LEVEL OMEGA WHICH COMBINED WITH A FEW HUNDRED JOULES OF SBCAPE WILL BE ENOUGH TO BRING SHOWERS/SCT THUNDER INTO AREAS WEST OF WORCESTER AND WILLIMANTIC. HRRR AND HIRES ARW/NMM ALL BRING A BAND OF HEAVY SHOWERS INTO W MA AND W CT AROUND 09Z. PRECIPITABLE WATER VALUES CLIMB OVER 1.5 INCHES ALL OF OUR AREA AND TO 2.0 INCHES IN WESTERN MASS AND CT. MEANWHILE THE PROJECTED STORM MOTION WILL BE SOUTHWEST AT 5-10 KNOTS. MAIN THREAT VERY LATE TONIGHT WILL BE LOCALLY HEAVY DOWNPOURS WHICH COULD CAUSE POOR DRAINAGE FLOODING. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... FRIDAY... SHOWERS/TSTMS FROM TONIGHT WILL EXPAND ACROSS SOUTHERN NEW ENGLAND FRIDAY MORNING. BY AFTERNOON MOST OF THE INSTABILITY WILL BE FOUND IN EASTERN MASS/RI AND SUPPORTED BY A MOIST FLOW OFF THE OCEAN. CONTINUED HIGH PRECIPITABLE WATER VALUES AND WEAK DYNAMICS. THE PROBLEM OF THE DAY SHOULD REMAIN LOCALLY HEAVY DOWNPOURS WHILE THE RISK OF SEVERE/DAMAGING WEATHER WILL BE LOW. SHOWER/TSTM POTENTIAL LINGERS FRIDAY NIGHT BUT WITH LOWER CHANCE THAN DURING THE DAY. WE CONSIDERED ISSUING A FLOOD WATCH FOR FRIDAY. BUT ANTECEDENT CONDITIONS ARE DRY AND MAY TAKE AS MUCH AS 3 INCHES FOR PROBLEMS TO DEVELOP. WE EXPECT THE HEAVIEST RAIN AMOUNTS TO FALL JUST SHY OF THAT. SO NO WATCH AT THIS TIME...BUT THE SITUATION WILL MERIT CLOSE MONITORING. WITH CLOUDS AND PCPN...EXPECT DAY/NIGHT TEMPERATURE CHANGES WILL BE LIMITED. MAX TEMPS MID 70S TO LOWER 80S...AND FRI NIGHT MIN TEMPS IN THE MID 60S TO AROUND 70. && .LONG TERM /SATURDAY THROUGH THURSDAY/... HIGHLIGHTS... * WARM AND HUMID CONDITIONS ALONG WITH SCATTERED SHOWERS AND THUNDERSTORMS PERSIST THROUGH TUE * DRY WEATHER AND LESS HUMID CONDITIONS WILL FOLLOW FOR WED/THU OVERVIEW... MODELS IN DECENT AGREEMENT ON LARGE SCALE PATTERN THROUGH MUCH OF NEXT WEEK FEATURING A BUILDING RIDGE ACROSS THE ROCKIES AND CENTRAL PLAINS AND CLOSED LOW MOVING INTO SE CANADA WITH MEAN TROF DEVELOPING ACROSS THE GT LAKES. WITH SUBTROPICAL AIRMASS IN PLACE AND DEVELOPING MOIST EASTERLY FLOW FROM APPROACHING LOW PRES MOVING NW FROM BERMUDA...UNSETTLED WEATHER EXPECTED THROUGH EARLY NEXT WEEK WITH SCT SHOWERS AND T-STORMS AT TIMES. THIS LOW MAY DEVELOP SUBTROPICAL OR TROPICAL CHARACTERISTICS BUT IS EXPECTED TO REMAIN WELL OUT TO SEA LATE SUN INTO MON. APPROACHING MID LEVEL TROF WILL BRING A COLD FRONT THROUGH THE REGION LATE TUE/TUE EVENING WHICH WILL FINALLY PUSH THE HUMIDITY OUT TO SEA WITH DRIER AIRMASS MOVING IN FOR WED/THU. SATURDAY... COLD FRONT WILL HAVE MOVED TO SE NEW COAST BY SAT MORNING...BUT FRONT IS EXPECTED TO WEAKEN AND EVENTUALLY GET ABSORBED BY DEVELOPING LOW LEVEL EASTERLY FLOW. MODELS SHOW AXIS OF INSTABILITY WITH CAPES 1000-1500 J/KG DEVELOPING ACROSS CENTRAL AND E NEW ENG AND WITH LEFTOVER CONVERGENCE FROM SFC BOUNDARY...EXPECT SCT SHOWERS AND T-STORMS TO DEVELOP. ACTIVITY SHOULD BE MAINLY CONFINED E OF THE CT VALLEY AS DRIER AIR AND MUCH LOWER KI ADVECT INTO W NEW ENG AND THE CT VALLEY WHICH SHOULD SUPPRESS CONVECTION IN THIS AREA. 0- 6KM SHEAR 20-25 KT IS A BIT LESS THAN WE WOULD LIKE TO SEE FOR SEVERE WEATHER...BUT GIVEN CAPES GREATER THAN 1000 J/KG CANT RULE OUT A FEW STRONG TO SEVERE STORMS. HEAVY RAINFALL WILL BE THE PRIMARY THREAT GIVEN PWATS 1.75 TO 2 INCHES. LOTS OF CLOUDS EXPECTED SAT WHICH WILL KEEP TEMPS IN THE UPPER 70S TO LOWER 80S...BUT QUITE HUMID IN THE COASTAL PLAIN WITH DEWPOINTS NEAR 70. LESS HUMID CONDITIONS IN W NEW ENG. SUNDAY AND MONDAY... GFS IS A WESTERN OUTLIER WITH LOW PRES MOVING NW FROM BERMUDA. THIS SYSTEM MAY BECOME SUBTROPICAL OR TROPICAL BUT IS EXPECTED TO REMAIN WELL OUT TO SEA. SUBTROPICAL MOISTURE AHEAD OF THIS SYSTEM WILL BE ADVECTED INTO THE REGION RESULTING IN QUITE HUMID CONDITIONS AND DEWPOINTS NEAR 70. THIS WILL LEAD TO MODEST INSTABILITY DEVELOPING AND A CONTINUED THREAT OF SCT SHOWERS/T-STORMS. HEAVY RAINFALL WILL BE PRIMARY THREAT IN HIGH PWAT AIRMASS. SEVERE THREAT IS LIMITED GIVEN RELATIVELY WEAK SHEAR BUT CAPES NEAR OR ABOVE 1000 J/KG SO CANT RULE OUT A FEW STRONG STORMS. TUESDAY... THIS MAY BE THE BEST CHANCE FOR ORGANIZED SEVERE WEATHER AS MID LEVEL TROF AND COLD FRONT APPROACHES FROM THE W. CAPES FORECAST TO BE GREATER THAN 1000 J/KG. INCREASING MID LEVEL WINDS MOVING IN FROM THE WEST RESULTS IN 0-6 KM SHEAR INCREASING TO 30-40 KT SO POTENTIAL EXISTS FOR STRONG TO SEVERE STORMS. STILL A DAY 5 FORECAST SO WILL HAVE TO CONTINUE TO MONITOR. WEDNESDAY AND THURSDAY... COLD FRONT MOVES OFFSHORE WITH HIGH PRES BUILDING IN FROM THE WEST WILL LEAD TO DRY AND LESS HUMID CONDITIONS. && .AVIATION /23Z THURSDAY THROUGH TUESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/... TONIGHT...MODERATE CONFIDENCE. IFR STRATUS DEVELOPING ALONG THE S COAST AND NORTH SHORE. EXPECT STRATUS TO CONTINUE TO DEVELOP AND GRADUALLY SPREAD INLAND WITH IFR/LIFR DEVELOPING ALONG WITH AREAS OF FOG. LOCALLY DENSE FOG IS POSSIBLE...MAINLY ALONG THE COAST. SHOWERS DEVELOPING IN THE BERKSHIRES AND CONNECTICUT RIVER VALLEY LATE AT NIGHT...TOWARD 09Z. LIGHT SOUTHEAST FLOW. FRIDAY...MODERATE CONFIDENCE. LOW CLOUDS AND FOG SHOULD LIFT TO SOME DEGREE BY LATE MORNING...BUT MVFR CONDITIONS MAY PERSIST INTO THE AFTERNOON. IN ADDITION...SHOWERS/SCATTERED THUNDERSTORMS WITH LOCALLY HEAVY RAINFALL WILL BE POSSIBLE. CIGS MAY IMPROVE TO VFR BUT VSBYS IN ANY SHOWERS/DOWNPOURS WILL BE MVFR AND LOCALLY IFR. LIGHT SOUTH TO SOUTHWEST FLOW. FRIDAY NIGHT...MODERATE CONFIDENCE. MVFR CIGS/VSBYS IN ANY SHOWERS/TSTMS WITH IFR POSSIBLE IN LOCALLY HEAVY DOWNPOURS. KBOS TERMINAL...MODERATE CONFIDENCE. EXPECT STRATUS TO DEVELOP/MOVE INTO LOGAN THIS EVENING. IFR FOG POSSIBLE LATER TONIGHT. KBDL TERMINAL...MODERATE TO HIGH CONFIDENCE. VFR. OUTLOOK /SATURDAY THROUGH TUESDAY/... SATURDAY...MODERATE CONFIDENCE. MVFR/IFR STRATUS AND PATCHY FOG E NEW ENG IN THE MORNING GRADUALLY IMPROVING. MOSTLY VFR W. HOWEVER... SCT SHOWERS/T-STORMS WITH LOCALLY HEAVY RAIN EXPECTED E OF CT VALLEY WITH BRIEF IFR POSSIBLE. SUNDAY THROUGH TUESDAY...MODERATE CONFIDENCE. MVFR/IFR CONDITIONS POSSIBLE AT TIMES IN NIGHTTIME STRATUS AND FOG ALONG WITH SCT SHOWERS/T-STORMS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /TODAY THROUGH FRIDAY/...HIGH CONFIDENCE. TONIGHT...HIGH PRESSURE OFFSHORE WITH A WEAK PRESSURE GRADIENT. EXPECT LIGHT SOUTHEAST FLOW WITH WINDS/SEAS BELOW SMALL CRAFT ADVISORY THRESHOLDS. FOG/LOW CLOUDS LINGERS ALONG CAPE ANN. ADDITIONAL FOG/LOW CLOUDS WILL REDEVELOP ALONG THE REMAINDER OF THE WATERS...BRINGING POOR VISIBILITY ESPECIALLY AFTER MIDNIGHT. FRIDAY AND FRIDAY NIGHT... WINDS AND SEAS REMAIN BELOW SMALL CRAFT THRESHOLDS. FOG/LOW CLOUDS WILL LIFT AND THIN...BUT SHOWERS/TSTMS AHEAD OF A WEAK COLD FRONT WILL MOVE OVER THE WATERS BY FRIDAY AFTERNOON AND FRIDAY NIGHT. OUTLOOK...SATURDAY THROUGH TUESDAY... SATURDAY...HIGH CONFIDENCE. LIGHT WINDS AND SEAS. POOR VSBYS IN MORNING FOG...IMPROVING IN THE AFTERNOON BUT MAY BE BRIEFLY REDUCED IN ANY SHOWERS AND T-STORMS. SUNDAY THROUGH TUESDAY...MODERATE CONFIDENCE. STRONGER WINDS FROM APPROACHING LOW PRES SHOULD REMAIN OFFSHORE LATE SUN INTO MON. EASTERLY WINDS MOSTLY LESS THAN 20 KT...WITH SW WINDS DEVELOPING TUE. BUILDING SWELL MAY LEAD TO 5+ FT SEAS OVER OUTER WATERS LATE SUN INTO MON. VSBYS REDUCED AT TIMES IN FOG. A FEW SHOWERS AND T- STORMS POSSIBLE. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...WTB/KJC NEAR TERM...WTB/KJC SHORT TERM...WTB LONG TERM...KJC AVIATION...WTB/KJC MARINE...WTB/KJC
AREA FORECAST DISCUSSION
NWS MIAMI FL
758 PM EDT THU AUG 20 2015 .AVIATION... SLIGHTLY WEAKER WIND FLOW WILL BE THE ONLY CHANGE TO THE CURRENT REGIME ON FRIDAY. IN ADDITION, A WEAKER OR NO SUBSIDENCE CAP MAY LEAD TO MORE NUMEROUS STORMS, SOME OF WHICH MAY BE CLOSER TO THE EAST COAST TAF SITES. HOWEVER, WITH FOCUS STILL OVER THE INTERIOR, AND NOT A GREAT DEAL OF CONFIDENCE, WILL NOT ADD VCTS AT THIS TIME TO THE EAST COAST. A BRIEF MVFR CIG CAN OCCUR ONCE AGAIN NEAR DAWN UNDER EAST FLOW. && .PREV DISCUSSION... /ISSUED 747 PM EDT THU AUG 20 2015/ UPDATE... MAKING SOME MINOR ADJUSTMENTS TO THE EVENING UPDATES BASED ON LATEST TRENDS. EARLY EVENING ACTIVITY SHOULD DIMINISH BY 02Z WITH THE GRADIENT FLOW WEAKENING CONSIDERABLY SO THE CHANCES FOR ATLANTIC DEVELOPMENT LATER TONIGHT MOVING ONSHORE SEEM RATHER REMOTE AT THIS TIME. NEITHER THE HRRR NOR THE LOCALLY RUN WRF SHOW THIS OCCURRING SO AM REMOVING MENTION OF THUNDER ALL AREAS WITH THE EXCEPTION OF THE THE OFFSHORE WATERS FOR LATER TONIGHT. KOB && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 78 92 77 92 / 10 40 20 40 FORT LAUDERDALE 79 91 79 92 / 10 40 20 50 MIAMI 79 92 79 94 / 10 40 30 50 NAPLES 78 90 78 91 / 10 40 30 50 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...30/KOB LONG TERM....30/KOB AVIATION...21/KM
AREA FORECAST DISCUSSION
NWS MIAMI FL
747 PM EDT THU AUG 20 2015 .UPDATE... MAKING SOME MINOR ADJUSTMENTS TO THE EVENING UPDATES BASED ON LATEST TRENDS. EARLY EVENING ACTIVITY SHOULD DIMINISH BY 02Z WITH THE GRADIENT FLOW WEAKENING CONSIDERABLY SO THE CHANCES FOR ATLANTIC DEVELOPMENT LATER TONIGHT MOVING ONSHORE SEEM RATHER REMOTE AT THIS TIME. NEITHER THE HRRR NOR THE LOCALLY RUN WRF SHOW THIS OCCURRING SO AM REMOVING MENTION OF THUNDER ALL AREAS WITH THE EXCEPTION OF THE THE OFFSHORE WATERS FOR LATER TONIGHT. KOB && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
230 PM EDT WED AUG 19 2015 .PREV DISCUSSION... /ISSUED 1113 AM EDT WED AUG 19 2015/ .UPDATE... MAIN ADJUSTMENTS IN THE NEAR TERM WERE TO LOWER POP TRENDS THROUGH MIDDAY AND FOCUS BEST CHANCE FOR SHOWERS AND STORMS IN THE AFTERNOON/EVENING PER THE NAM 305 THETA UPGLIDE ZONES AND THE HRRR AS THIS HI-RES SOLUTION SEEMS TO BE THE ONLY ONE LATCHING ON TO THE LACK OF COVERAGE OBSERVED THUS FAR. STILL VERY TROPICAL AIRMASS WITH 1.9 INCH PWAT OFF THIS MORNING SOUNDING AND JUST OVER 2.0 INCH FOR BMX SO CONTINUING THE FLOODING THREAT AND STRONG TO BRIEFLY SEVERE POTENTIAL WITH AFTERNOON DESTABILIZATION. THE BIG PLAYER FOR THIS EVENING AND OVERNIGHT WILL BE THE EVOLUTION OF A LARGE CONVECTIVE COMPLEX CURRENTLY UPSTREAM ACROSS LOUISIANA. THE HRRR ALSO HAS THE MCS/MCV BRINGING AT LEAST ANOTHER ROUND OF WIDESPREAD SHOWERS BY 02-06Z TONIGHT THOUGH SOME UNCERTAINTY WITH INTENSITY OF CONVECTION. WILL BE MONITORING THIS FOR AFTERNOON FCST ISSUANCE AND MAY NEED TO RAISE OVERNIGHT POPS ACCORDINGLY. PREVIOUS DISCUSSION FOLLOWS... BAKER && PREV DISCUSSION... /ISSUED 731 AM EDT WED AUG 19 2015/ PREV DISCUSSION... /ISSUED 430 AM EDT WED AUG 19 2015/ .SHORT TERM /TODAY THROUGH THURSDAY/... MODELS IN GOOD AGREEMENT THROUGH THE SHORT TERM WITH A VERY GOOD GULF CONNECTION SPREADING DEEP MOISTURE OVER THE CWA. THIS WILL CONTINUE INTO WEDNESDAY KEEP SCATTERED TO WIDESPREAD SHOWERS AND TSTORMS OVER THE CWA. THE BEST CHANCES WILL BE ACROSS NORTH GEORGIA AND MAINLY DURING THE AFTERNOON AND EVENING HOURS. ALTHOUGH THUNDER WILL BE MINIMAL EARLY THIS MORNING AND ALSO WEDNESDAY MORNING... EXPECT THUNDER TO BECOME MORE NUMEROUS WITH DAYTIME HEATING THIS AFTERNOON AND INTO THE EARLY EVENING HOURS. ALTHOUGH THE GREATEST INSTABILITY WILL BE ACROSS NORTH GA...AN ISOLATED STRONG TO SEVERE STORM WILL BE POSSIBLE JUST ABOUT ANYWHERE THIS AFTERNOON AND EVENING WITH THE MAIN THREAT BEING STRONG WINDS. TEMPERATURES THROUGH WEDNESDAY WILL BE PRETTY CLOSE TO PERSISTENCE DUE TO CLOUDS AND PRECIP...AND THE MODELS HAVE A GOOD HANDLE ON THIS. 17 && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... PATTERN STILL ON TRACK TO SHIFT TO WEAK W-E ZONAL FLOW ACROSS THE SE CONUS LATE THIS WEEK THEN GO INTO WEAK NW FLOW ON THIS WEEKEND. SOME INDICATIONS THAT A WEAK SHORTWAVE WILL AFFECT AREA ON SUNDAY BY 00Z MED RANGE MODELS. HAVE BUMPED POPS UP A LITTLE FROM BLEND. CHC FOR FROPA NOW LOOKING LESS LIKELY EARLY NEXT WEEK SO IN THE SOUP WE STAY. DAYTIME TEMPS SHOULD BE AT OR SLIGHTLY BELOW NORMAL SO SOME CONSOLATION. ATLANTIC BASIN HAS ITS FOURTH NAMED STORM...TS DANNY...AND COULD AFFECT INTERESTS IN THE VIRGIN ISLANDS AND PERHAPS PUERTO RICO NEXT WEEK AS DANNY MOVES SLOWLY WEST. NO OTHER FEATURES OF NOTE THRU TUES. SNELSON 17 .AVIATION... 18Z UPDATE... INITIAL CIGS OF HIGH END MVFR TO LOW END VFR IN 2500-3500 FT RANGE WITH SCATTERED SHOWERS AND TSRA POTENTIAL UP UNTIL 00Z OR SLIGHTLY AFTER WITH LINGERING -SHRA POSSIBLY THRU 04Z FROM A DISTURBANCE TRACKING ALONG THE TROPICAL SW FLOW. CIGS LOOK TO LOWER AGAIN TO IFR SIMILAR TO PREVIOUS MORNINGS FOR 09-14Z WITH GRADUAL IMPROVEMENT AND AGAIN CHANCE FOR PRECIP AND -TSRA RETURNING NEAR 18Z TOMORROW. WINDS SHOULD STAY MAINLY SW TO WEST AT 5-8 KTS WITH LIGHT TO CALM OVERNIGHT. EXPECT REDUCED VSBYS WITH ANY TSRA IN MVFR/IFR RANGE. //ATL CONFIDENCE...18Z UPDATE... MEDIUM ON PRECIP TIMING AND OVERNIGHT CIGS. HIGH ON ALL ELSE. BAKER && .PRELIMINARY POINT TEMPS/POPS... ATHENS 84 71 89 72 / 70 50 60 30 ATLANTA 86 71 88 72 / 70 60 60 30 BLAIRSVILLE 79 70 82 65 / 70 70 60 30 CARTERSVILLE 86 72 86 69 / 70 60 60 30 COLUMBUS 87 74 88 74 / 70 60 60 30 GAINESVILLE 82 71 84 71 / 70 60 60 30 MACON 89 73 91 73 / 60 40 50 30 ROME 85 71 85 69 / 70 70 60 30 PEACHTREE CITY 87 71 90 71 / 70 60 60 30 VIDALIA 91 73 94 75 / 50 40 50 30 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...17/BAKER LONG TERM....SNELSON AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1113 AM EDT WED AUG 19 2015 .UPDATE... MAIN ADJUSTMENTS IN THE NEAR TERM WERE TO LOWER POP TRENDS THROUGH MIDDAY AND FOCUS BEST CHANCE FOR SHOWERS AND STORMS IN THE AFTERNOON/EVENING PER THE NAM 305 THETA UPGLIDE ZONES AND THE HRRR AS THIS HI-RES SOLUTION SEEMS TO BE THE ONLY ONE LATCHING ON TO THE LACK OF COVERAGE OBSERVED THUS FAR. STILL VERY TROPICAL AIRMASS WITH 1.9 INCH PWAT OFF THIS MORNING SOUNDING AND JUST OVER 2.0 INCH FOR BMX SO CONTINUING THE FLOODING THREAT AND STRONG TO BRIEFLY SEVERE POTENTIAL WITH AFTERNOON DESTABILIZATION. THE BIG PLAYER FOR THIS EVENING AND OVERNIGHT WILL BE THE EVOLUTION OF A LARGE CONVECTIVE COMPLEX CURRENTLY UPSTREAM ACROSS LOUISIANA. THE HRRR ALSO HAS THE MCS/MCV BRINGING AT LEAST ANOTHER ROUND OF WIDESPREAD SHOWERS BY 02-06Z TONIGHT THOUGH SOME UNCERTAINTY WITH INTENSITY OF CONVECTION. WILL BE MONITORING THIS FOR AFTERNOON FCST ISSUANCE AND MAY NEED TO RAISE OVERNIGHT POPS ACCORDINGLY. PREVIOUS DISCUSSION FOLLOWS... BAKER && .PREV DISCUSSION... /ISSUED 731 AM EDT WED AUG 19 2015/ PREV DISCUSSION... /ISSUED 430 AM EDT WED AUG 19 2015/ .SHORT TERM /TODAY THROUGH THURSDAY/... MODELS IN GOOD AGREEMENT THROUGH THE SHORT TERM WITH A VERY GOOD GULF CONNECTION SPREADING DEEP MOISTURE OVER THE CWA. THIS WILL CONTINUE INTO WEDNESDAY KEEP SCATTERED TO WIDESPREAD SHOWERS AND TSTORMS OVER THE CWA. THE BEST CHANCES WILL BE ACROSS NORTH GEORGIA AND MAINLY DURING THE AFTERNOON AND EVENING HOURS. ALTHOUGH THUNDER WILL BE MINIMAL EARLY THIS MORNING AND ALSO WEDNESDAY MORNING... EXPECT THUNDER TO BECOME MORE NUMEROUS WITH DAYTIME HEATING THIS AFTERNOON AND INTO THE EARLY EVENING HOURS. ALTHOUGH THE GREATEST INSTABILITY WILL BE ACROSS NORTH GA...AN ISOLATED STRONG TO SEVERE STORM WILL BE POSSIBLE JUST ABOUT ANYWHERE THIS AFTERNOON AND EVENING WITH THE MAIN THREAT BEING STRONG WINDS. TEMPERATURES THROUGH WEDNESDAY WILL BE PRETTY CLOSE TO PERSISTENCE DUE TO CLOUDS AND PRECIP...AND THE MODELS HAVE A GOOD HANDLE ON THIS. 17 && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... PATTERN STILL ON TRACK TO SHIFT TO WEAK W-E ZONAL FLOW ACROSS THE SE CONUS LATE THIS WEEK THEN GO INTO WEAK NW FLOW ON THIS WEEKEND. SOME INDICATIONS THAT A WEAK SHORTWAVE WILL AFFECT AREA ON SUNDAY BY 00Z MED RANGE MODELS. HAVE BUMPED POPS UP A LITTLE FROM BLEND. CHC FOR FROPA NOW LOOKING LESS LIKELY EARLY NEXT WEEK SO IN THE SOUP WE STAY. DAYTIME TEMPS SHOULD BE AT OR SLIGHTLY BELOW NORMAL SO SOME CONSOLATION. ATLANTIC BASIN HAS ITS FOURTH NAMED STORM...TS DANNY...AND COULD AFFECT INTERESTS IN THE VIRGIN ISLANDS AND PERHAPS PUERTO RICO NEXT WEEK AS DANNY MOVES SLOWLY WEST. NO OTHER FEATURES OF NOTE THRU TUES. SNELSON 17 && .AVIATION... 12Z UPDATE... A MIX OF IFR/MVFR WILL CONTINUE THROUGH MID MORNING THEN RISE TO VFR BY 16Z AND REMAIN VFR UNTIL EVENING. SCATTERED LIGHT SHOWERS ACROSS THE FORECAST AREA WILL BECOME MORE NUMEROUS TODAY...THEN DIMINISH AFTER SUNSET. WINDS WILL REMAIN SOUTHWEST LESS THAN 10 KTS. //ATL CONFIDENCE...12Z UPDATE... MEDIUM ON CIGS THIS MORNING MEDIUM ON TIMING OF SHRA/TSRA HIGH ON REMAINING ELEMENTS 17 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 84 71 89 72 / 70 50 60 30 ATLANTA 86 71 88 72 / 70 60 60 30 BLAIRSVILLE 79 70 82 65 / 70 70 60 30 CARTERSVILLE 86 72 86 69 / 70 60 60 30 COLUMBUS 87 74 88 74 / 70 60 60 30 GAINESVILLE 82 71 84 71 / 70 60 60 30 MACON 89 73 91 73 / 60 40 50 30 ROME 85 71 85 69 / 70 70 60 30 PEACHTREE CITY 87 71 90 71 / 70 60 60 30 VIDALIA 91 73 94 75 / 50 40 50 30 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...17/BAKER LONG TERM....SNELSON AVIATION...17
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
754 AM EDT WED AUG 19 2015 .SYNOPSIS... DEEP MOISTURE WILL REMAIN ACROSS THE AREA THE AREA TODAY INTO THURSDAY WITH SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. A WEAK FRONT WILL APPROACH THE AREA ON THURSDAY. THE FRONT WILL DISSIPATE NEAR THE AREA SATURDAY...WITH HIGH PRESSURE RETURNING FOR SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... OUR REGION WILL RESIDE ALONG THE NORTHERN PERIPHERY OF THE UPPER RIDGE CENTERED ACROSS FLORIDA INTO THE GULF OF MEXICO. COULD SEE WEAK SHORT WAVES CROSS THE AREA IN SOUTHWEST FLOW ALOFT. THE AIR MASS WILL REMAIN QUITE MOIST WITH PWAT VALUES AT OR ABOVE 2 INCHES. GIVEN POSSIBLE SHORT WAVES...WEAK TO MODERATE INSTABILITY...AMPLE MOISTURE AND DAYTIME HEATING...WE EXPECT ANOTHER DAY OF SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. THE HRRR MODEL HAS ONE AREA OF CONVECTION EXITING TO THE NORTHEAST EARLY THIS MORNING...THEN NEXT ROUND MOVING INTO THE REGION FROM THE WEST EARLY THIS AFTERNOON. HEAVY DOWNPOURS ONCE AGAIN POSSIBLE. SHOWERS AND THUNDERSTORMS EXPECTED TO LINGER INTO TONIGHT AS A PRE- FRONTAL TROUGH DEVELOP ACROSS THE CAROLINAS. KEPT TEMPERATURES CLOSE TO GUIDANCE CONSENSUS WITH HIGHS IN THE UPPER 80S TO LOWER 90S AND LOWS IN THE LOW TO MID 70S. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... OUR WET PATTERN WILL HOLD THURSDAY INTO FRIDAY AS A WEAK COLD FRONT MOVES INTO THE AREA. PRECIPITABLE WATER WILL REMAIN HIGH WITH VALUES MAINLY AROUND 2 INCHES. HEAVY DOWNPOURS MAY OCCUR WITH SOME OF THE THUNDERSTORMS. THE FRONT MAY SLIDE JUST SOUTH AND EAST OF THE MIDLANDS AND CSRA FRIDAY. HAVE FOLLOWED GUIDANCE TRENDS WITH HIGH CHANCE POPS FOR THURSDAY THEN LOW CHANCE FOR FRIDAY. USED THE GUIDANCE CONSENSUS FOR THE HIGH TEMPERATURE FORECAST. USED THE WARMER LOW TEMPERATURE GUIDANCE BECAUSE OF THE HIGH MOISTURE. && .LONG TERM /SATURDAY THROUGH TUESDAY/... THE GFS AND ECMWF DISPLAY A DIFFUSE FRONT STALLED NEAR THE FORECAST AREA EARLY IN THE MEDIUM-RANGE PERIOD. THE MODELS DISPLAY ANOTHER FRONT LATE IN THE PERIOD. THE MODELS HAVE UPPER RIDGING SATURDAY...WITH TROUGHING DURING THE REST OF THE PERIOD. THE PATTERN SUPPORTS A CONTINUED CHANCE OF SHOWERS AND THUNDERSTORMS. THE GFS ENSEMBLE MEAN PLUS GFS...ECMWF...AND EKD MOS SUPPORT POPS OF MAINLY 20 TO 30 PERCENT. ABOVE NORMAL HIGH TEMPERATURES SHOULD BE ASSOCIATED WITH THE UPPER RIDGING EARLY IN THE PERIOD. THE REST OF THE PERIOD WILL LIKELY HAVE NEAR NORMAL TEMPERATURES. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... VFR CONDITIONS EXPECTED OUTSIDE OF FOG/STRATUS THIS MORNING AND SHOWERS/THUNDERSTORMS THROUGH TONIGHT. RESTRICTIONS IN FOG AND STRATUS HAVE DEVELOPED THIS MORNING IN THE CSRA BUT MIXING SHOULD ALLOW A RETURN TO VFR BY 14Z. DEEP MOISTURE AND HEATING WILL PROMOTE THE DEVELOPMENT OF SHOWERS ONCE AGAIN THIS AFTERNOON...WHICH MAY BRING BRIEF RESTRICTIONS TO VISIBILITY AT ALL TAF SITES. WINDS WILL BE OUT OF THE SOUTHWEST TODAY AT 5 TO 10 KNOTS. EXTENDED AVIATION OUTLOOK...A MOIST SOUTHERLY FLOW WILL CONTINUE THROUGH THURSDAY. THERE WILL BE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. STRATUS AND FOG MAY OCCUR DURING THE EARLY MORNING HOURS. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
418 AM EDT WED AUG 19 2015 .SYNOPSIS... DEEP MOISTURE WILL REMAIN ACROSS THE AREA THE AREA TODAY INTO THURSDAY WITH SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. A WEAK FRONT WILL APPROACH THE AREA ON THURSDAY. THE FRONT WILL DISSIPATE NEAR THE AREA SATURDAY...WITH HIGH PRESSURE RETURNING FOR SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... OUR REGION WILL RESIDE ALONG THE NORTHERN PERIPHERY OF THE UPPER RIDGE CENTERED ACROSS FLORIDA INTO THE GULF OF MEXICO. COULD SEE WEAK SHORT WAVES CROSS THE AREA IN SOUTHWEST FLOW ALOFT. THE AIR MASS WILL REMAIN QUITE MOIST WITH PWAT VALUES AT OR ABOVE 2 INCHES. GIVEN POSSIBLE SHORT WAVES...WEAK TO MODERATE INSTABILITY...AMPLE MOISTURE AND DAYTIME HEATING...WE EXPECT ANOTHER DAY OF SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. THE HRRR MODEL HAS ONE AREA OF CONVECTION EXITING TO THE NORTHEAST EARLY THIS MORNING...THEN NEXT ROUND MOVING INTO THE REGION FROM THE WEST EARLY THIS AFTERNOON. HEAVY DOWNPOURS ONCE AGAIN POSSIBLE. SHOWERS AND THUNDERSTORMS EXPECTED TO LINGER INTO TONIGHT AS A PRE- FRONTAL TROUGH DEVELOP ACROSS THE CAROLINAS. KEPT TEMPERATURES CLOSE TO GUIDANCE CONSENSUS WITH HIGHS IN THE UPPER 80S TO LOWER 90S AND LOWS IN THE LOW TO MID 70S. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... OUR WET PATTERN WILL HOLD THURSDAY INTO FRIDAY AS A WEAK COLD FRONT MOVES INTO THE AREA. PRECIPITABLE WATER WILL REMAIN HIGH WITH VALUES MAINLY AROUND 2 INCHES. HEAVY DOWNPOURS MAY OCCUR WITH SOME OF THE THUNDERSTORMS. THE FRONT MAY SLIDE JUST SOUTH AND EAST OF THE MIDLANDS AND CSRA FRIDAY. HAVE FOLLOWED GUIDANCE TRENDS WITH HIGH CHANCE POPS FOR THURSDAY THEN LOW CHANCE FOR FRIDAY. USED THE GUIDANCE CONSENSUS FOR THE HIGH TEMPERATURE FORECAST. USED THE WARMER LOW TEMPERATURE GUIDANCE BECAUSE OF THE HIGH MOISTURE. && .LONG TERM /SATURDAY THROUGH TUESDAY/... THE GFS AND ECMWF DISPLAY A DIFFUSE FRONT STALLED NEAR THE FORECAST AREA EARLY IN THE MEDIUM-RANGE PERIOD. THE MODELS DISPLAY ANOTHER FRONT LATE IN THE PERIOD. THE MODELS HAVE UPPER RIDGING SATURDAY...WITH TROUGHING DURING THE REST OF THE PERIOD. THE PATTERN SUPPORTS A CONTINUED CHANCE OF SHOWERS AND THUNDERSTORMS. THE GFS ENSEMBLE MEAN PLUS GFS...ECMWF...AND EKD MOS SUPPORT POPS OF MAINLY 20 TO 30 PERCENT. ABOVE NORMAL HIGH TEMPERATURES SHOULD BE ASSOCIATED WITH THE UPPER RIDGING EARLY IN THE PERIOD. THE REST OF THE PERIOD WILL LIKELY HAVE NEAR NORMAL TEMPERATURES. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... S/W MOVING ACROSS THE AREA OVERNIGHT. AHEAD OF THIS FEATURE A LINE OF SHOWERS AND SCATTERED THUNDERSTORMS CONTINUES TO MOVE EAST- NORTHEAST ACROSS THE EASTERN PORTION OF THE CWA. THE STRONGEST STORMS AREA ACROSS CHESTERFIELD COUNTY AND MOVING INTO THE PEE DEE/S CNTRL NC. ALL TAF SITES CURRENTLY REPORTING VFR CONDITIONS. HAVE CONTINUED THROUGH 07Z THE MENTION OF SHOWERS AT OGB...OTHERWISE EXPECT MAINLY DRY CONDITIONS FOR THE REMAINDER OF THE NIGHT. WINDS GENERALLY VARIABLE DUE TO BOUNDARIES ACROSS THE AREA. MODELS DO HINT AT SOME ENHANCED MOISTURE IN LOW-LEVELS LATE TONIGHT...BUT DO NOT EXPECT ANY WIDESPREAD FOG DUE TO AN OVERNIGHT LOW-LEVEL JET AND EXPECTED CLOUDS. CONFIDENCE REMAINS LOW...BUT DID MENTION MVFR BR AT AGS/OGB TOWARDS MORNING. ADDITIONAL SHOWERS SHOULD ONCE AGAIN FORM THIS AFTERNOON...WHICH MAY BRING BRIEF RESTRICTIONS TO VISIBILITY AT ALL TAF SITES. EXTENDED AVIATION OUTLOOK...A MOIST SOUTHERLY FLOW WILL CONTINUE THROUGH THURSDAY. THERE WILL BE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. STRATUS AND FOG MAY OCCUR DURING THE EARLY MORNING HOURS. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
109 AM EDT WED AUG 19 2015 .PREV DISCUSSION... /ISSUED 1020 PM EDT TUE AUG 18 2015/ UPDATE... THUNDER KEEPS DIMINISHING ACROSS THE CWFA THIS EVENING. HAVE TWEAKED POPS ACCORDING TO THE LATEST RADAR TRENDS. THE HRRR KEEPS ONLY A FEW SHOWERS AROUND OVERNIGHT...SO HAVE LOWERED POPS A BIT. MODELS ARE A LITTLE SLOWER STARTING THE PRECIP TOMORROW...SO DELAYED THE ONSET OF THE LIKELY POPS. PREV DISCUSSION... /ISSUED 343 PM EDT TUE AUG 18 2015/ SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... NO MAJOR CHANGES IN THE OVERALL WET PATTERN IS EXPECTED AS AN ACTIVE SOUTHWEST FLOW ALOFT CONTINUES TO INTERACT WITH VERY MOIST AND MODERATELY UNSTABLE ENVIRONMENT TO PRODUCE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS... MAINLY DURING DAYTIME HEATING BETWEEN NOON AND 10 PM... WITH MAINLY ISOLATED TO SCATTERED SHOWERS LINGERING OVERNIGHT. ALTHOUGH MOST STORMS WILL REMAIN WELL UNDER SEVERE LIMITS... AN ISOLATED STRONG TO SEVERE STORM CANNOT BE RULED OUT DURING THE LATE AFTERNOON AND EARLY EVENING HOURS TODAY... AND AGAIN ON WEDNESDAY AS CAPE VALUES CLIMB INTO THE 2500-3000 J/KG RANGE. THE GREATER CONVECTIVE CONCERN IS THE POTENTIAL FOR BRIEF FLOODING AS ENTRENCHED DEEP TROPICAL MOISTURE SUPPORTS LOCALLY HEAVY DOWNPOURS... EVEN FROM SHOWERS... THAT CAN QUICKLY DUMP 1-3 INCHES IN A SHORT PERIOD OF TIME. WILL NEED TO MONITOR ANY FLASHY... FLOOD PRONE CREEKS CLOSELY OVER THE NEXT COUPLE OF DAYS OR MORE. OTHERWISE... WILL LEAN TOWARD PERSISTENCE FOR TEMPS AS AMPLE LOWS CLOUDS TONIGHT AND WEDNESDAY NIGHT HOLD LOWS IN THE 70S... AND WIDESPREAD CONVECTION HELP HOLD HIGHS ON WEDNESDAY MOSTLY IN THE 80S... EXCEPT SOME LOWER 90S IN THE FAR SOUTHERN REACHES. 39 LONG TERM /THURSDAY THROUGH TUESDAY/... NO MAJOR CHANGES MADE TO THE FORECAST PERIOD AS THE LONG TERM SOLUTIONS IN DECENT AGREEMENT EXCEPT FOR LATE IN THE PERIOD. GFS HAS LOWER AMPLITUDE UPPER TROUGH DYNAMICS BY EARLY NEXT WEEK AND THUS STRUGGLES TO PUSH A FRONT THROUGH BUT HAVE LEANED MORE TOWARD PREVIOUS FORECAST AND EARLIER ECMWF TO KEEP CONSISTENCY. OTHERWISE HAVE REFRESHED OTHER FIELDS WITH LATEST BLEND. PREVIOUS DISCUSSION FOLLOWS... BAKER LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... PATTERN IN LONG TERM PERIOD TRANSITIONS FROM HIGH AMPLITUDE TROUGH ALONG THE MS RIVER VALLEY STATES ON WED TO ZONAL FLOW THIS WEEKEND AND FINALLY WEAK NW FLOW/UPR RIDGE TO THE WEST WITH A HINT OF A MDT FROPA ON MONDAY. WITH THE FIRST TWO PATTERNS...SE CONUS SHOULD REMAIN IN MOIST PATTERN WITH DEEP MOISTURE THRU THE WEEKEND. NO ONE DAY SEEMS TO STAND OUT WITH PRECIP CHCS NOR DO ANY DAYS SEEM TO HAVE CHC FOR SVR OR EVEN STRONG DEEP CONVECTION. MED RANGE MODELS IN GOOD AGREEMENT. WPC PREFERRING BLEND OF ALL 00Z OPERATIONAL MODELS FOR FEATURES AFFECTING CWA THRU DAY 7. TROPICAL ACTIVITY REMAINS SUBDUED. COLD CORE UPPER LOW OFF CAROLINA COAST...WHICH HAS PLAYED A ROLE IN CREATING STAGNANT PATTERN OF LATE AND MAY BECOME TROPICAL IN NATURE...SHOULD GET PICKED UP BY UPPER TROUGH THIS WEEKEND AND LIFT AWAY FROM EAST COAST. LOW LATITUDE DISTURBANCE AT 35W LONGITUDE THAT TPC IS TRACKING COULD DEVELOP INTO A NAMED STORM BUT PROGGED TO REMAIN ON WESTERLY COURSE WITH MEAGER INTENSITY BY ECMWF AND GFS. BY NO MEANS A GUARANTEE BUT THATS THE LATEST 411. SNELSON && .AVIATION... 06Z UPDATE... A FEW AREAS OF STRATUS HAVE BEGUN TO DEVELOP AND SHOULD BECOME MOSTLY IFR CIGS BY LATER THIS MORNING...RISING TO VFR BY NOON. ISOLATED/SCATTERED SHOWERS WILL MOVE INTO THE WESTERN TAF AREAS THIS MORNING AND BECOMING WIDESPREAD OVER ALL THE FORECAST AREA THIS AFTERNOON...DIMINISHING AFTER SUNSET. WINDS WILL REMAIN LIGHT SOUTHWEST THROUGH THE FORECAST EXCEPT GUSTY IN STORMS. //ATL CONFIDENCE...06Z UPDATE... LOW TO MEDIUM ON CIGS THIS MORNING MEDIUM ON TIMING OF SHRA/TSRA HIGH ON REMAINING ELEMENTS 17 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 89 73 89 73 / 70 70 70 30 ATLANTA 87 73 87 73 / 70 70 70 30 BLAIRSVILLE 81 68 80 66 / 80 80 70 30 CARTERSVILLE 87 72 86 70 / 80 80 70 30 COLUMBUS 89 74 90 75 / 70 70 60 30 GAINESVILLE 85 72 85 72 / 70 70 70 30 MACON 91 74 91 74 / 70 70 60 30 ROME 86 72 85 71 / 80 80 70 30 PEACHTREE CITY 88 72 88 72 / 70 70 70 30 VIDALIA 91 75 92 76 / 70 60 50 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...17 LONG TERM....SNELSON AVIATION...17
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
424 PM EDT WED AUG 19 2015 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW && .SYNOPSIS... ISSUED AT 242 PM EDT WED AUG 19 2015 TWO SYSTEMS WILL IMPACT THE WEATHER ACROSS CENTRAL INDIANA OVER THE FORECAST PERIOD. THE FIRST IS CURRENTLY MAKING ITS WAY INTO THE UPPER MIDWEST...AND ITS ASSOCIATED COLD FRONT WILL TRIGGER SHOWERS AND THUNDERSTORMS ACROSS THE AREA THIS EVENING AND INTO TONIGHT. AFTER A DRY PERIOD FROM HIGH PRESSURE THROUGH SATURDAY...ANOTHER SYSTEM WILL INITIATE CONVECTIVE DEVELOPMENT SUNDAY AFTERNOON AND NIGHT. FURTHER OUT...HIGH PRESSURE WILL RETURN AT THE BEGINNING OF NEXT WEEK. && .NEAR TERM /THIS EVENING AND TONIGHT/... ISSUED AT 242 PM EDT WED AUG 19 2015 THE MAIN FOCUS OF THE NEAR TERM PERIOD IS SHOWER AND THUNDERSTORM CHANCES AS COLD FRONT ENTERS CENTRAL INDIANA. SYNOPTICALLY...A RATHER STRONG LOW PRESSURE SYSTEM IS CURRENTLY ROTATING OVER THE UPPER MIDWEST WHILE ITS ASSOCIATED COLD FRONT MAKES ITS WAY INTO NORTHWEST INDIANA. RADAR TRENDS HAVE BEEN LEANING TOWARD INCREASING CONVECTIVE DEVELOPMENT ACROSS CENTRAL INDIANA OVER THE LAST FEW HOURS AND WILL CONTINUE TO STRENGTHEN THROUGH THU 06Z AS AFOREMENTIONED COLD FRONT APPROACHES CENTRAL INDIANA. BEST FRONTOGENETIC FORCING IN LOWER AND MID LEVELS WILL BE DURING THE THU 06-12Z TIME FRAME FROM WEST/NORTHWEST TO EAST/SOUTHEAST ACROSS FORECAST AREA. NONETHELESS...SUBSTANTIAL MOISTURE AND AFTERNOON HEATING AHEAD OF THE FRONT WILL BE ENOUGH TO SUSTAIN PRE-FRONTAL SHOWERS AND THUNDERSTORMS THIS EVENING...WITH POTENTIAL FOR ISOLATED STRONG TO SEVERE DEVELOPMENT AT TIMES. TEMPS WILL FALL BELOW NORMAL TONIGHT IN WAKE OF COLD FRONT WITH OVERNIGHT LOWS DIPPING INTO THE UPPER 50S/LOW 60S. SOME MID 50S CAN EVEN BE EXPECTED ACROSS THE NORTHWEST PORTIONS OF THE FORECAST AREA. MODELS SEEM TO HAVE A GOOD HANDLE ON THE FRONTAL PASSAGE...SO STUCK CLOSE TO A BLEND. && .SHORT TERM /TOMORROW THROUGH SATURDAY/... ISSUED AT 242 PM EDT WED AUG 19 2015 COLD FRONT WILL BE THROUGH THE FORECAST AREA BY THU 12Z...BUT RESIDUAL CLOUD COVER WILL LINGER ACROSS THE EASTERN COUNTIES TOMORROW MORNING UNTIL THE ASSOCIATED UPPER LOW PUSHES FARTHER EAST. AFTER THAT...FLOW WILL BECOME MORE ZONAL ALOFT AND HIGH PRESSURE WILL STRENGTHEN AT THE SURFACE OVER THE OHIO VALLEY. SO...DRY CONDITIONS CAN BE EXPECTED INTO SATURDAY. TEMPERATURES WILL START OUT WELL BELOW NORMAL FOR THE FIRST HALF OF THE SHORT TERM PERIOD AS THEY TRY TO REBOUND FROM THE AFOREMENTIONED COLD FRONT. SO...HIGHS WILL ONLY BE IN THE MID TO UPPER 70S FOR THURSDAY...AND UPPER 70S/LOW 80S BY FRIDAY. THEY WILL START TO RECOVER BY SATURDAY THOUGH WITH MORE WIDESPREAD LOW 80S. MEANWHILE...DECENT RADIATIONAL COOLING AT NIGHT WILL KEEP LOWS SIGNIFICANTLY BELOW NORMAL WITH READINGS IN THE 50S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... ISSUED AT 201 PM EDT WED AUG 19 2015 ECMWF AND GFS BLEND PRETTY WELL DURING THE PERIOD. BOTH MODELS SUGGEST A DECENT COLD FRONT ALONG WITH A SHORT WAVE ALOFT PASSING THROUGH CENTRAL INDIANA ON SUNDAY NIGHT INTO EARLY MONDAY. A WARM AND MOIST AIR MASS ALONG WITH SOUTHERLY FLOW MAY ALSO LEAD TO SOME AFTERNOON PEAK HEATING DAYTIME CONVECTION ACROSS CENTRAL INDIANA. THUS HAVE INCLUDED POPS STARTING SUNDAY AFTERNOON THROUGH LATE SUNDAY NIGHT. HIGH PRESSURE LOOKS TO RETURN TO THE AREA ON MONDAY AND NORTHWEST FLOW RESUMES ALOFT AND AN UPPER LOW CONTINUE TO PULL NORTHEAST TOWARD QUEBEC. THIS ALONG WITH HIGH PRESSURE IN PLACE AT THE SURFACE WILL ALLOW FOR SUBSIDENCE AND DRY WEATHER ACROSS CENTRAL INDIANA. LOOK FOR TEMPS TO BE AT OR BELOW NORMALS THROUGH THIS PERIOD AS NORTHWEST FLOW IS EXPECTED TO PERSIST THROUGH MUCH OF THE PERIOD. && .AVIATION /DISCUSSION FOR THE 192100Z TAF UPDATE/... ISSUED AT 424 PM EDT WED AUG 19 2015 BULK OF TSRA REMAINS WELL SOUTH OF KIND...AND RECENT TRENDS INDICATE THAT THIS WILL CONTINUE THE NEXT FEW HOURS. HAVE THUS CHANGED VCTS TO VCSH FOR THE NEXT FEW HOURS. STILL EXPECTING SOME DEVELOPMENT OF TSRA WITH COLD FRONT THIS EVENING SO LEFT TEMPO TSRA GROUP IN FOR NOW. PREVIOUS DISCUSSION FOLLOWS... VFR CONDITIONS EXPECTED FOR THE NEXT FEW HOURS. MVFR CONDITIONS WILL BE EXPECTED THIS AFTERNOON AND OVERNIGHT. A RETURN TO VFR IS EXPECTED AFTER 14Z THURSDAY. CONVECTIVE TEMPS IN THE LOWER 80S ARE EXPECTED TO BE REACHED MOMENTARILY. TSRA DEVELOPMENT IS EXPECTED ACROSS SOUTHERN ILLINOIS AND WESTERN INDIANA AHEAD OF THE APPROACHING FRONTAL BOUNDARY. HRRR SHOWS AREAS OF THUNDERSTORMS DEVELOPING AND PUSHING ACROSS CENTRAL INDIANA DURING THE PEAK HEATING HOURS AND EARLY THIS EVENING. THUS WILL INCLUDE A PERIOD OF VCSH ALONG WITH A TEMPO PERIOD FOR THUNDER DURING THE MOST FAVORABLE WINDOW FOR THUNDERSTORMS. AFTER DYNAMICS AND FORCING MOVES EAST AFTER 06Z...FORECAST SOUNDINGS AND TIME HEIGHTS ALONG WITH THE SUGGESTION OF RECENT RAINS INDICATE LOWER LEVEL MOISTURE AND STRATOCU/MVFR FOG LINGERING OVERNIGHT. AS HIGH PRESSURE ARRIVES IN THE AREA ON THURSDAY ALONG WITH SUBSIDENCE...A QUICK RETURN TO VFR IS EXPECTED. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...TDUD NEAR TERM...TDUD SHORT TERM...TDUD LONG TERM....PUMA AVIATION...JP/50
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
359 PM EDT WED AUG 19 2015 .UPDATE... THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW && .SYNOPSIS... ISSUED AT 242 PM EDT WED AUG 19 2015 TWO SYSTEMS WILL IMPACT THE WEATHER ACROSS CENTRAL INDIANA OVER THE FORECAST PERIOD. THE FIRST IS CURRENTLY MAKING ITS WAY INTO THE UPPER MIDWEST...AND ITS ASSOCIATED COLD FRONT WILL TRIGGER SHOWERS AND THUNDERSTORMS ACROSS THE AREA THIS EVENING AND INTO TONIGHT. AFTER A DRY PERIOD FROM HIGH PRESSURE THROUGH SATURDAY...ANOTHER SYSTEM WILL INITIATE CONVECTIVE DEVELOPMENT SUNDAY AFTERNOON AND NIGHT. FURTHER OUT...HIGH PRESSURE WILL RETURN AT THE BEGINNING OF NEXT WEEK. && .NEAR TERM /THIS EVENING AND TONIGHT/... ISSUED AT 242 PM EDT WED AUG 19 2015 THE MAIN FOCUS OF THE NEAR TERM PERIOD IS SHOWER AND THUNDERSTORM CHANCES AS COLD FRONT ENTERS CENTRAL INDIANA. SYNOPTICALLY...A RATHER STRONG LOW PRESSURE SYSTEM IS CURRENTLY ROTATING OVER THE UPPER MIDWEST WHILE ITS ASSOCIATED COLD FRONT MAKES ITS WAY INTO NORTHWEST INDIANA. RADAR TRENDS HAVE BEEN LEANING TOWARD INCREASING CONVECTIVE DEVELOPMENT ACROSS CENTRAL INDIANA OVER THE LAST FEW HOURS AND WILL CONTINUE TO STRENGTHEN THROUGH THU 06Z AS AFOREMENTIONED COLD FRONT APPROACHES CENTRAL INDIANA. BEST FRONTOGENETIC FORCING IN LOWER AND MID LEVELS WILL BE DURING THE THU 06-12Z TIME FRAME FROM WEST/NORTHWEST TO EAST/SOUTHEAST ACROSS FORECAST AREA. NONETHELESS...SUBSTANTIAL MOISTURE AND AFTERNOON HEATING AHEAD OF THE FRONT WILL BE ENOUGH TO SUSTAIN PRE-FRONTAL SHOWERS AND THUNDERSTORMS THIS EVENING...WITH POTENTIAL FOR ISOLATED STRONG TO SEVERE DEVELOPMENT AT TIMES. TEMPS WILL FALL BELOW NORMAL TONIGHT IN WAKE OF COLD FRONT WITH OVERNIGHT LOWS DIPPING INTO THE UPPER 50S/LOW 60S. SOME MID 50S CAN EVEN BE EXPECTED ACROSS THE NORTHWEST PORTIONS OF THE FORECAST AREA. MODELS SEEM TO HAVE A GOOD HANDLE ON THE FRONTAL PASSAGE...SO STUCK CLOSE TO A BLEND. && .SHORT TERM /TOMORROW THROUGH SATURDAY/... ISSUED AT 242 PM EDT WED AUG 19 2015 COLD FRONT WILL BE THROUGH THE FORECAST AREA BY THU 12Z...BUT RESIDUAL CLOUD COVER WILL LINGER ACROSS THE EASTERN COUNTIES TOMORROW MORNING UNTIL THE ASSOCIATED UPPER LOW PUSHES FARTHER EAST. AFTER THAT...FLOW WILL BECOME MORE ZONAL ALOFT AND HIGH PRESSURE WILL STRENGTHEN AT THE SURFACE OVER THE OHIO VALLEY. SO...DRY CONDITIONS CAN BE EXPECTED INTO SATURDAY. TEMPERATURES WILL START OUT WELL BELOW NORMAL FOR THE FIRST HALF OF THE SHORT TERM PERIOD AS THEY TRY TO REBOUND FROM THE AFOREMENTIONED COLD FRONT. SO...HIGHS WILL ONLY BE IN THE MID TO UPPER 70S FOR THURSDAY...AND UPPER 70S/LOW 80S BY FRIDAY. THEY WILL START TO RECOVER BY SATURDAY THOUGH WITH MORE WIDESPREAD LOW 80S. MEANWHILE...DECENT RADIATIONAL COOLING AT NIGHT WILL KEEP LOWS SIGNIFICANTLY BELOW NORMAL WITH READINGS IN THE 50S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... ISSUED AT 201 PM EDT WED AUG 19 2015 ECMWF AND GFS BLEND PRETTY WELL DURING THE PERIOD. BOTH MODELS SUGGEST A DECENT COLD FRONT ALONG WITH A SHORT WAVE ALOFT PASSING THROUGH CENTRAL INDIANA ON SUNDAY NIGHT INTO EARLY MONDAY. A WARM AND MOIST AIR MASS ALONG WITH SOUTHERLY FLOW MAY ALSO LEAD TO SOME AFTERNOON PEAK HEATING DAYTIME CONVECTION ACROSS CENTRAL INDIANA. THUS HAVE INCLUDED POPS STARTING SUNDAY AFTERNOON THROUGH LATE SUNDAY NIGHT. HIGH PRESSURE LOOKS TO RETURN TO THE AREA ON MONDAY AND NORTHWEST FLOW RESUMES ALOFT AND AN UPPER LOW CONTINUE TO PULL NORTHEAST TOWARD QUEBEC. THIS ALONG WITH HIGH PRESSURE IN PLACE AT THE SURFACE WILL ALLOW FOR SUBSIDENCE AND DRY WEATHER ACROSS CENTRAL INDIANA. LOOK FOR TEMPS TO BE AT OR BELOW NORMALS THROUGH THIS PERIOD AS NORTHWEST FLOW IS EXPECTED TO PERSIST THROUGH MUCH OF THE PERIOD. && .AVIATION /DISCUSSION FOR THE 191800Z IND TAFS/... ISSUED AT 116 PM EDT WED AUG 19 2015 VFR CONDITIONS EXPECTED FOR THE NEXT FEW HOURS. MVFR CONDITIONS WILL BE EXPECTED THIS AFTERNOON AND OVERNIGHT. A RETURN TO VFR IS EXPECTED AFTER 14Z THURSDAY. CONVECTIVE TEMPS IN THE LOWER 80S ARE EXPECTED TO BE REACHED MOMENTARILY. TSRA DEVELOPMENT IS EXPECTED ACROSS SOUTHERN ILLINOIS AND WESTERN INDIANA AHEAD OF THE APPROACHING FRONTAL BOUNDARY. HRRR SHOWS AREAS OF THUNDERSTORMS DEVELOPING AND PUSHING ACROSS CENTRAL INDIANA DURING THE PEAK HEATING HOURS AND EARLY THIS EVENING. THUS WILL INCLUDE A PERIOD OF VCSH ALONG WITH A TEMPO PERIOD FOR THUNDER DURING THE MOST FAVORABLE WINDOW FOR THUNDERSTORMS. AFTER DYNAMICS AND FORCING MOVES EAST AFTER 06Z...FORECAST SOUNDINGS AND TIME HEIGHTS ALONG WITH THE SUGGESTION OF RECENT RAINS INDICATE LOWER LEVEL MOISTURE AND STRATOCU/MVFR FOG LINGERING OVERNIGHT. AS HIGH PRESSURE ARRIVES IN THE AREA ON THURSDAY ALONG WITH SUBSIDENCE...A QUICK RETURN TO VFR IS EXPECTED. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...TDUD NEAR TERM...TDUD SHORT TERM...TDUD LONG TERM....PUMA AVIATION...JP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
208 PM EDT WED AUG 19 2015 .UPDATE... THE LONG TERM SECTION HAS BEEN UPDATED BELOW && .SYNOPSIS... ISSUED AT 218 AM EDT WED AUG 19 2015 A STRONG FRONTAL SYSTEM...FOR THIS TIME OF YEAR...WILL BRING WIDESPREAD THUNDERSTORMS TO CENTRAL INDIANA TODAY AND TONIGHT. SOME OF THE STORMS COULD BE STRONG OR POSSIBLY EVEN SEVERE. THEN...HIGH PRESSURE WILL PROVIDE FOR DRY CONDITIONS THROUGH SATURDAY. ANOTHER SEASONABLY STRONG FRONTAL SYSTEM WILL BRING MORE STORMS TO THE AREA SUNDAY AND SUNDAY NIGHT BEFORE HIGH PRESSURE AND DRY WEATHER RETURN MONDAY. TEMPERATURES WILL BE BELOW NORMAL...ESPECIALLY LATE THIS WORK WEEK AND EARLY NEXT WEEK FOLLOWING THE FRONTAL PASSAGES...WHEN HIGHS WILL BE IN THE 70S AND LOWS IN THE 50S. && .NEAR TERM /REST OF TODAY AND TONIGHT/... ISSUED AT 947 AM EDT WED AUG 19 2015 UPDATE... LATEST RADAR MOSAIC SHOWS SCATTERED SHOWERS CONFINED TO THE FAR SOUTHERN TIER OF COUNTIES IN CENTRAL INDIANA. THIS CORRELATES WELL WITH LOCATION OF BEST INSTABILITY AT THIS HOUR. CONVECTIVE ACTIVITY IS STILL EXPECTED TO BECOME MORE WIDESPREAD AND STRONGER THROUGH THE COURSE OF THE AFTERNOON AS COLD FRONT APPROACHES FROM THE WEST. PLUS...THE FIRST WAVE OF SHOWERS AND THUNDERSTORMS HAVE STAYED FARTHER SOUTH THAN ORIGINALLY ANTICIPATED. SO...WITH MORE BREAKS IN CLOUD COVER...THE FRONT MAY HAVE MORE INSTABILITY TO WORK WITH ACROSS THE NORTHERN TWO-THIRDS OF THE FORECAST AREA LATER TODAY. CURRENT TEMPS ACROSS THE AREA ARE GENERALLY IN THE 70S WITH DEWPOINTS IN THE MID TO UPPER 60S. WINDS ARE SOUTH/SOUTHWESTERLY AT 10 TO 14 MPH...GUSTING TO 21 MPH. PREVIOUS DISCUSSIONS... ISSUED AT 620 AM EDT WED AUG 19 2015 LATEST RADAR TRENDS ARE BRINGING WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS TO ABOUT AN INDIANAPOLIS TO LAFAYETTE LINE AROUND 8 AM. RAISED POPS TO CATEGORICAL SLIGHTLY EARLIER. FIRST WAVE OF STORMS SHOULD BE EAST OF THE AREA AROUND 16Z WITH STORMS DEVELOPING AND ALSO MOVING IN FROM THE WEST SHORTLY THEREAFTER. THIS SHOULD KEEP THINGS FROM BECOMING TO UNSTABLE AND SUPPORTS THE MARGINAL SEVERE RISK AS OPPOSED TO SLIGHT RISK. PREVIOUS DISCUSSION FOLLOWS... ISSUED AT 218 AM EDT WED AUG 19 2015 THUNDERSTORMS...SOME STRONG AND POSSIBLY SEVERE...WILL BE THE MAIN FOCUS FOR THE NEAR TERM AS A STRONG LOW PRESSURE SYSTEM...FOR LATE AUGUST...LIFTS NORTHEAST ACROSS LAKE SUPERIOR AND NORTHWEST ONTARIO DRAGGING A COLD FRONT ACROSS CENTRAL INDIANA. RAP13 AND HIGH RES RAPID REFRESH SEEM TO HAVE A DECENT HANDLE ON CONVECTIVE EVOLUTION COMPARED TO THE LATEST RADAR TRENDS. THUNDERSTORMS WERE LIFTING NORTHEAST OVER NORTHWESTERN PARTS OF CENTRAL INDIANA EARLY THIS OVERNIGHT AND THE REFLECTIVITY PROGS FROM THE RAPID REFRESH WERE BRINGING THE INDIVIDUAL STORMS NORTHEAST BUT THE AREA OF CONVECTION SOUTHEAST AHEAD OF A COLD FRONT THAT EXTENDED FROM A SURFACE LOW OVER SOUTH CENTRAL MINNESOTA TO NORTHEASTERN MISSOURI AND NORTHEASTERN OKLAHOMA. THE GFS CONTINUES TO BE A FAST OUTLIER WITH ITS 00Z WEDNESDAY RUN WITH REGARDS TO THE FRONTAL PASSAGE OVER CENTRAL INDIANA AND THUS WILL BE IGNORED WITH A BLEND BETWEEN THE OTHER SIMILAR OPERATIONAL MODELS ACCEPTED. NON-GFS BLEND TAKES THE COLD FRONT TO NEAR CHICAGO TO ST. LOUIS LINE 12Z THIS MORNING...TO A VALPO TO CARBONDALE LINE AT 18Z AND TO AROUND A FORT WAYNE TO INDIANAPOLIS LINE BY 00Z THURSDAY. MEANWHILE...THE FRONT SHOULD BE THROUGH CENTRAL OHIO AND EASTERN KENTUCKY BY 12Z THURSDAY WHICH SHOULD PUT AN END TO THE CONVECTION FROM NORTHWEST TO SOUTHEAST OVERNIGHT TONIGHT. HOWEVER...PRIOR TO THAT...THE RAPID REFRESH WAS BRINGING EASTERN MISSOURI STORMS OVER CENTRAL INDIANA IN THE 11Z-15Z TIME FRAME. MEANWHILE...MORE WIDESPREAD STORMS ARE EXPECTED THIS AFTERNOON AS THE FRONT GETS CLOSER. MODELS MAY BE OVERDOING IT A LITTLE ON INSTABILITY AS BREAK BETWEEN MORNING AND AFTERNOON CONVECTION SHOULD NOT BE TOO LONG. THAT SAID...EVEN THE LEAST UNSTABLE ECMWF HAD 500 J/KG OR MORE MIXED LAYER CAPE TODAY TO GO ALONG WITH THE DYNAMICS. 20-30 KNOT LOW LEVEL JET ACROSS WEST CENTRAL INDIANA AND APPROACHING NEGATIVELY-TILTED TROUGH SUGGESTS LIKELY TO CATEGORICAL POPS THROUGH THIS EVENING BEFORE DROPPING OFF FROM NORTHWEST TO SOUTHEAST LATE TONIGHT. FAST UPPER JET AROUND THE BASE OF THE TROUGH WILL PUSH INDIVIDUAL CELLS THROUGH QUICKLY...SO DO NOT FORESEE A BIG FLASH FLOOD THREAT DESPITE THE DYNAMICS AND PRECIPITABLE WATER AMOUNTS TO 2 INCHES. REGARDING SEVERE THREAT...AREA CONTINUES TO BE IN A MARGINAL RISK FOR THIS AFTERNOON AND EVENING. THIS LOOKS REASONABLE. ISOLATED DAMAGING WINDS WILL BE THE MAIN SEVERE THREAT. WITH LITTLE BREAKS IN THE CLOUDS TODAY...WENT WITH THE COOLEST 00Z NAM MOS WITH HIGHS IN THE UPPER 70S AND LOWER 80S. MOS LOWS CLOSE TONIGHT AND LOOK REASONABLE. COOLEST TEMPERATURES WILL BE NORTHWESTERN PARTS...WHERE BREAKS IN THE CLOUDS WILL OCCUR FIRST BEHIND THE FRONT. WILL BE A LITTLE CHILLY WITH LOWS IN THE UPPER 50S TO LOWER 60S. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... ISSUED AT 218 AM EDT WED AUG 19 2015 MAIN FOCUS FOR THE SHORT TERM WILL BE ON TEMPERATURES AS SURFACE HIGH PRESSURE BUILDS OVER THE OHIO VALLEY BY LATE THURSDAY BEHIND THE COLD FRONT AND TRAILING UPPER TROUGH ALLOWING FOR CLEAR SKIES AND COOL TEMPERATURES FOR THIS TIME OF YEAR. THE HIGH WILL SHIFT TO SOUTHERN ONTARIO BY FRIDAY NIGHT...BUT DRY COLUMN AND FRONTAL SYSTEM WELL TO THE WEST SHOULD ENSURE DRY WEATHER. LOW LEVEL THERMAL PROGS AND LITTLE CLOUD COVER SUPPORT SIMILAR BLEND OF 00Z MOS WITH AFTERNOON HIGHS IN THE MID AND UPPER 70S ON THURSDAY AND UPPER 70S TO LOWER 80S ON FRIDAY. WITH STRONG RADIATIONAL COOLING...IT WILL BE QUITE COOL WITH OVERNIGHT LOWS IN THE 50S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... ISSUED AT 201 PM EDT WED AUG 19 2015 ECMWF AND GFS BLEND PRETTY WELL DURING THE PERIOD. BOTH MODELS SUGGEST A DECENT COLD FRONT ALONG WITH A SHORT WAVE ALOFT PASSING THROUGH CENTRAL INDIANA ON SUNDAY NIGHT INTO EARLY MONDAY. A WARM AND MOIST AIR MASS ALONG WITH SOUTHERLY FLOW MAY ALSO LEAD TO SOME AFTERNOON PEAK HEATING DAYTIME CONVECTION ACROSS CENTRAL INDIANA. THUS HAVE INCLUDED POPS STARTING SUNDAY AFTERNOON THROUGH LATE SUNDAY NIGHT. HIGH PRESSURE LOOKS TO RETURN TO THE AREA ON MONDAY AND NORTHWEST FLOW RESUMES ALOFT AND AN UPPER LOW CONTINUE TO PULL NORTHEAST TOWARD QUEBEC. THIS ALONG WITH HIGH PRESSURE IN PLACE AT THE SURFACE WILL ALLOW FOR SUBSIDENCE AND DRY WEATHER ACROSS CENTRAL INDIANA. LOOK FOR TEMPS TO BE AT OR BELOW NORMALS THROUGH THIS PERIOD AS NORTHWEST FLOW IS EXPECTED TO PERSIST THROUGH MUCH OF THE PERIOD. && .AVIATION /DISCUSSION FOR THE 191800Z IND TAFS/... ISSUED AT 116 PM EDT WED AUG 19 2015 VFR CONDITIONS EXPECTED FOR THE NEXT FEW HOURS. MVFR CONDITIONS WILL BE EXPECTED THIS AFTERNOON AND OVERNIGHT. A RETURN TO VFR IS EXPECTED AFTER 14Z THURSDAY. CONVECTIVE TEMPS IN THE LOWER 80S ARE EXPECTED TO BE REACHED MOMENTARILY. TSRA DEVELOPMENT IS EXPECTED ACROSS SOUTHERN ILLINOIS AND WESTERN INDIANA AHEAD OF THE APPROACHING FRONTAL BOUNDARY. HRRR SHOWS AREAS OF THUNDERSTORMS DEVELOPING AND PUSHING ACROSS CENTRAL INDIANA DURING THE PEAK HEATING HOURS AND EARLY THIS EVENING. THUS WILL INCLUDE A PERIOD OF VCSH ALONG WITH A TEMPO PERIOD FOR THUNDER DURING THE MOST FAVORABLE WINDOW FOR THUNDERSTORMS. AFTER DYNAMICS AND FORCING MOVES EAST AFTER 06Z...FORECAST SOUNDINGS AND TIME HEIGHTS ALONG WITH THE SUGGESTION OF RECENT RAINS INDICATE LOWER LEVEL MOISTURE AND STRATOCU/MVFR FOG LINGERING OVERNIGHT. AS HIGH PRESSURE ARRIVES IN THE AREA ON THURSDAY ALONG WITH SUBSIDENCE...A QUICK RETURN TO VFR IS EXPECTED. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...MK NEAR TERM...MK/TDUD SHORT TERM...MK LONG TERM....PUMA AVIATION...JP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
116 PM EDT WED AUG 19 2015 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW && .SYNOPSIS... ISSUED AT 218 AM EDT WED AUG 19 2015 A STRONG FRONTAL SYSTEM...FOR THIS TIME OF YEAR...WILL BRING WIDESPREAD THUNDERSTORMS TO CENTRAL INDIANA TODAY AND TONIGHT. SOME OF THE STORMS COULD BE STRONG OR POSSIBLY EVEN SEVERE. THEN...HIGH PRESSURE WILL PROVIDE FOR DRY CONDITIONS THROUGH SATURDAY. ANOTHER SEASONABLY STRONG FRONTAL SYSTEM WILL BRING MORE STORMS TO THE AREA SUNDAY AND SUNDAY NIGHT BEFORE HIGH PRESSURE AND DRY WEATHER RETURN MONDAY. TEMPERATURES WILL BE BELOW NORMAL...ESPECIALLY LATE THIS WORK WEEK AND EARLY NEXT WEEK FOLLOWING THE FRONTAL PASSAGES...WHEN HIGHS WILL BE IN THE 70S AND LOWS IN THE 50S. && .NEAR TERM /REST OF TODAY AND TONIGHT/... ISSUED AT 947 AM EDT WED AUG 19 2015 UPDATE... LATEST RADAR MOSAIC SHOWS SCATTERED SHOWERS CONFINED TO THE FAR SOUTHERN TIER OF COUNTIES IN CENTRAL INDIANA. THIS CORRELATES WELL WITH LOCATION OF BEST INSTABILITY AT THIS HOUR. CONVECTIVE ACTIVITY IS STILL EXPECTED TO BECOME MORE WIDESPREAD AND STRONGER THROUGH THE COURSE OF THE AFTERNOON AS COLD FRONT APPROACHES FROM THE WEST. PLUS...THE FIRST WAVE OF SHOWERS AND THUNDERSTORMS HAVE STAYED FARTHER SOUTH THAN ORIGINALLY ANTICIPATED. SO...WITH MORE BREAKS IN CLOUD COVER...THE FRONT MAY HAVE MORE INSTABILITY TO WORK WITH ACROSS THE NORTHERN TWO-THIRDS OF THE FORECAST AREA LATER TODAY. CURRENT TEMPS ACROSS THE AREA ARE GENERALLY IN THE 70S WITH DEWPOINTS IN THE MID TO UPPER 60S. WINDS ARE SOUTH/SOUTHWESTERLY AT 10 TO 14 MPH...GUSTING TO 21 MPH. PREVIOUS DISCUSSIONS... ISSUED AT 620 AM EDT WED AUG 19 2015 LATEST RADAR TRENDS ARE BRINGING WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS TO ABOUT AN INDIANAPOLIS TO LAFAYETTE LINE AROUND 8 AM. RAISED POPS TO CATEGORICAL SLIGHTLY EARLIER. FIRST WAVE OF STORMS SHOULD BE EAST OF THE AREA AROUND 16Z WITH STORMS DEVELOPING AND ALSO MOVING IN FROM THE WEST SHORTLY THEREAFTER. THIS SHOULD KEEP THINGS FROM BECOMING TO UNSTABLE AND SUPPORTS THE MARGINAL SEVERE RISK AS OPPOSED TO SLIGHT RISK. PREVIOUS DISCUSSION FOLLOWS... ISSUED AT 218 AM EDT WED AUG 19 2015 THUNDERSTORMS...SOME STRONG AND POSSIBLY SEVERE...WILL BE THE MAIN FOCUS FOR THE NEAR TERM AS A STRONG LOW PRESSURE SYSTEM...FOR LATE AUGUST...LIFTS NORTHEAST ACROSS LAKE SUPERIOR AND NORTHWEST ONTARIO DRAGGING A COLD FRONT ACROSS CENTRAL INDIANA. RAP13 AND HIGH RES RAPID REFRESH SEEM TO HAVE A DECENT HANDLE ON CONVECTIVE EVOLUTION COMPARED TO THE LATEST RADAR TRENDS. THUNDERSTORMS WERE LIFTING NORTHEAST OVER NORTHWESTERN PARTS OF CENTRAL INDIANA EARLY THIS OVERNIGHT AND THE REFLECTIVITY PROGS FROM THE RAPID REFRESH WERE BRINGING THE INDIVIDUAL STORMS NORTHEAST BUT THE AREA OF CONVECTION SOUTHEAST AHEAD OF A COLD FRONT THAT EXTENDED FROM A SURFACE LOW OVER SOUTH CENTRAL MINNESOTA TO NORTHEASTERN MISSOURI AND NORTHEASTERN OKLAHOMA. THE GFS CONTINUES TO BE A FAST OUTLIER WITH ITS 00Z WEDNESDAY RUN WITH REGARDS TO THE FRONTAL PASSAGE OVER CENTRAL INDIANA AND THUS WILL BE IGNORED WITH A BLEND BETWEEN THE OTHER SIMILAR OPERATIONAL MODELS ACCEPTED. NON-GFS BLEND TAKES THE COLD FRONT TO NEAR CHICAGO TO ST. LOUIS LINE 12Z THIS MORNING...TO A VALPO TO CARBONDALE LINE AT 18Z AND TO AROUND A FORT WAYNE TO INDIANAPOLIS LINE BY 00Z THURSDAY. MEANWHILE...THE FRONT SHOULD BE THROUGH CENTRAL OHIO AND EASTERN KENTUCKY BY 12Z THURSDAY WHICH SHOULD PUT AN END TO THE CONVECTION FROM NORTHWEST TO SOUTHEAST OVERNIGHT TONIGHT. HOWEVER...PRIOR TO THAT...THE RAPID REFRESH WAS BRINGING EASTERN MISSOURI STORMS OVER CENTRAL INDIANA IN THE 11Z-15Z TIME FRAME. MEANWHILE...MORE WIDESPREAD STORMS ARE EXPECTED THIS AFTERNOON AS THE FRONT GETS CLOSER. MODELS MAY BE OVERDOING IT A LITTLE ON INSTABILITY AS BREAK BETWEEN MORNING AND AFTERNOON CONVECTION SHOULD NOT BE TOO LONG. THAT SAID...EVEN THE LEAST UNSTABLE ECMWF HAD 500 J/KG OR MORE MIXED LAYER CAPE TODAY TO GO ALONG WITH THE DYNAMICS. 20-30 KNOT LOW LEVEL JET ACROSS WEST CENTRAL INDIANA AND APPROACHING NEGATIVELY-TILTED TROUGH SUGGESTS LIKELY TO CATEGORICAL POPS THROUGH THIS EVENING BEFORE DROPPING OFF FROM NORTHWEST TO SOUTHEAST LATE TONIGHT. FAST UPPER JET AROUND THE BASE OF THE TROUGH WILL PUSH INDIVIDUAL CELLS THROUGH QUICKLY...SO DO NOT FORESEE A BIG FLASH FLOOD THREAT DESPITE THE DYNAMICS AND PRECIPITABLE WATER AMOUNTS TO 2 INCHES. REGARDING SEVERE THREAT...AREA CONTINUES TO BE IN A MARGINAL RISK FOR THIS AFTERNOON AND EVENING. THIS LOOKS REASONABLE. ISOLATED DAMAGING WINDS WILL BE THE MAIN SEVERE THREAT. WITH LITTLE BREAKS IN THE CLOUDS TODAY...WENT WITH THE COOLEST 00Z NAM MOS WITH HIGHS IN THE UPPER 70S AND LOWER 80S. MOS LOWS CLOSE TONIGHT AND LOOK REASONABLE. COOLEST TEMPERATURES WILL BE NORTHWESTERN PARTS...WHERE BREAKS IN THE CLOUDS WILL OCCUR FIRST BEHIND THE FRONT. WILL BE A LITTLE CHILLY WITH LOWS IN THE UPPER 50S TO LOWER 60S. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... ISSUED AT 218 AM EDT WED AUG 19 2015 MAIN FOCUS FOR THE SHORT TERM WILL BE ON TEMPERATURES AS SURFACE HIGH PRESSURE BUILDS OVER THE OHIO VALLEY BY LATE THURSDAY BEHIND THE COLD FRONT AND TRAILING UPPER TROUGH ALLOWING FOR CLEAR SKIES AND COOL TEMPERATURES FOR THIS TIME OF YEAR. THE HIGH WILL SHIFT TO SOUTHERN ONTARIO BY FRIDAY NIGHT...BUT DRY COLUMN AND FRONTAL SYSTEM WELL TO THE WEST SHOULD ENSURE DRY WEATHER. LOW LEVEL THERMAL PROGS AND LITTLE CLOUD COVER SUPPORT SIMILAR BLEND OF 00Z MOS WITH AFTERNOON HIGHS IN THE MID AND UPPER 70S ON THURSDAY AND UPPER 70S TO LOWER 80S ON FRIDAY. WITH STRONG RADIATIONAL COOLING...IT WILL BE QUITE COOL WITH OVERNIGHT LOWS IN THE 50S. && .LONG TERM /SATURDAY THROUGH TUESDAY/... ISSUED AT 307 AM EDT WED AUG 19 2015 HIGH PRESSURE WILL MOVE NORTHEAST AWAY FROM CENTRAL INDIANA ON SATURDAY NIGHT ALLOWING A LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT TO SLIDE INTO THE AREA ON SUNDAY. MODELS HAVE TRENDED A LITTLE SLOWER WITH THE ARRIVAL OF THIS SYSTEM AND THUS SATURDAY NIGHT NOW LOOKS DRY. THE AFOREMENTIONED COLD FRONT WILL BRING THUNDERSTORM CHANCES FOR SUNDAY AND SUNDAY NIGHT TO THE AREA. BY MONDAY THOUGH CANADIAN HIGH PRESSURE WILL BUILD BACK IN OVER CENTRAL INDIANA AND USHER IN BELOW NORMAL HIGHS IN THE 70S ALONG WITH DRY WEATHER. && .AVIATION /DISCUSSION FOR THE 191800Z IND TAFS/... ISSUED AT 116 PM EDT WED AUG 19 2015 VFR CONDITIONS EXPECTED FOR THE NEXT FEW HOURS. MVFR CONDITIONS WILL BE EXPECTED THIS AFTERNOON AND OVERNIGHT. A RETURN TO VFR IS EXPECTED AFTER 14Z THURSDAY. CONVECTIVE TEMPS IN THE LOWER 80S ARE EXPECTED TO BE REACHED MOMENTARILY. TSRA DEVELOPMENT IS EXPECTED ACROSS SOUTHERN ILLINOIS AND WESTERN INDIANA AHEAD OF THE APPROACHING FRONTAL BOUNDARY. HRRR SHOWS AREAS OF THUNDERSTORMS DEVELOPING AND PUSHING ACROSS CENTRAL INDIANA DURING THE PEAK HEATING HOURS AND EARLY THIS EVENING. THUS WILL INCLUDE A PERIOD OF VCSH ALONG WITH A TEMPO PERIOD FOR THUNDER DURING THE MOST FAVORABLE WINDOW FOR THUNDERSTORMS. AFTER DYNAMICS AND FORCING MOVES EAST AFTER 06Z...FORECAST SOUNDINGS AND TIME HEIGHTS ALONG WITH THE SUGGESTION OF RECENT RAINS INDICATE LOWER LEVEL MOISTURE AND STRATOCU/MVFR FOG LINGERING OVERNIGHT. AS HIGH PRESSURE ARRIVES IN THE AREA ON THURSDAY ALONG WITH SUBSIDENCE...A QUICK RETURN TO VFR IS EXPECTED. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...MK NEAR TERM...MK/TDUD SHORT TERM...MK LONG TERM....CP AVIATION...JP
...UPDATE TO AVIATION FORECAST DISCUSSION...

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 335 PM CDT TUE AUG 18 2015 19Z WATER VAPOR SHOWS A CLOSED UPPER LOW OVER SD WHILE SURFACE OBS PLACE THE LOW OVER NORTHWEST IA/SOUTHWEST MN BORDER. A STRONG COLD FRONT EXTENDED SOUTH FROM THE SURFACE LOW THROUGH SOUTHEAST NEB TO JUST WEST OF SLN. VISIBLE SATELLITE HAS SHOWN SOME BREAKS IN THE CLOUDS AHEAD OF THE FRONT WHICH HAS ALLOWED TEMPS TO WARM INTO THE LOWER 80S. THIS WOULD SUPPORT SURFACE BASED CAPE VALUES AROUND 1000J/KG WHILE 0-6 KM SHEAR INCREASES TO AROUND 45 KTS. SO THE POTENTIAL FOR SEVERE STORMS REMAINS IN PLACE. MODELS SHOW AREA ALONG AND SOUTH OF I-70 AS THE PLACES THAT SHOULD SEE THE BETTER INSTABILITY. THEREFORE THINK THIS MAY BE WHERE STRONG TO SEVERE STORMS DEVELOP THIS AFTERNOON, IF THEY STRENGTHEN. SINCE SURFACE WINDS HAVE VEERED TO THE SOUTHWEST AHEAD OF THE FRONT, THE POTENTIAL FOR TORNADOES APPEARS TO REMAIN FAIRLY SMALL. THE RAP AND HRRR, WHICH HAVE SHOWN A BETTER TIMING FOR THE FRONT, TAKE THE BOUNDARY EAST OF THE FORECAST AREA BETWEEN 8 AND 9 PM. THE RISK FOR SEVERE WEATHER SHOULD DIMINISH QUICKLY BEHIND THE FRONT AS COOLER MORE STABLE AIR COMES IN. ONCE THE FRONT PASSES EAST, THINK THE REST OF TONIGHT WILL BE FAIRLY UNEVENTFUL. THERE HAVE BEEN SOME LOWER CLOUDS ACROSS WESTERN NEB MIST OF THE DAY BUT THE MODELS TEND TO KEEP THE LOWER CLOUDS TO THE NORTH OVERNIGHT. THEREFORE WITH COLD AIR ADVECTION AND MOST LIKELY PARTLY CLOUDY SKIES, LOWS IN THE MID AND UPPER 50S LOOKS ON TARGET. BY LATE TONIGHT AND THROUGH THE MORNING WEDNESDAY, MODELS SWING A DECENT VORT MAX THROUGH THE BASE OF THE UPPER TROUGH PASSING THROUGH EASTERN KS. THERE IS NO SIGN OF LOW LEVEL MOISTURE ADVECTION OVER THE COLD FRONT, BUT THERE IS AN INDICATION OF A SATURATED AIRMASS ACROSS EAST CENTRAL KS WITH GOOD FRONTOGENESIS AS THE WAVE PASSES OVERHEAD. BECAUSE OF THIS HAVE CONTINUED WITH SOME CHANCE POPS FOR RAIN MAINLY OVER EAST CENTRAL KS. THERE SHOULD BE MORE DRY AIR OVER NORTH CENTRAL AND NORTHEAST KS THAT WILL LIMIT PRECIP CHANCES. THE COLD AIR ADVECTION WEAKENS THROUGH THE DAY WEDNESDAY, BUT THERE MAY BE SOME CLOUDS LINGER. THEREFORE HIGHS ARE FORECAST TO TOP OUT IN THE LOWER AND MID 70S. THIS IS ABOUT 15 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 335 PM CDT TUE AUG 18 2015 LOWER LEVEL WINDS BACK TO THE WEST WEDNESDAY NIGHT AND THEN SOUTHWEST INTO THURSDAY NIGHT BRINGING SOME WARMING BACK AND SURFACE TEMPS SHOULD MODIFY CONSIDERABLY. HAVE KEPT VALUES NEAR TO BELOW MOS FOR WEDNESDAY NIGHT IN LIGHT WINDS AND CLEAR SKIES. MODELS TRENDING A BIT COOLER FOR FRIDAY WITH CONTINUED BACKED TO NEAR SOUTHEAST WITH HIGHS STILL LIKELY CLOSE TO THOSE OF THURSDAY. PRECIP CHANCES CONTINUE TO LOOK QUITE LOW THROUGH THURSDAY NIGHT. AT LEAST SOME MOISTURE RETURNS AHEAD OF A WEAK UPPER WAVE FRIDAY...THOUGH THERE REMAINS TO BE A WIDE DEGREE OF VARIANCE IN BOTH OF THESE ELEMENTS...WITH A TREND TOWARD LOWER AVAILABLE MOISTURE NOTED. AT THIS POINT CHANCES FOR ANYTHING MORE THAN ISOLATED PRECIP LOOK LOW. FOR THE BEGINNING OF THE WEEKEND, RETURN FLOW WILL BE IN PLACE OVER THE SOUTHERN AND CENTRAL PLAINS AHEAD OF A DEEPENING TROUGH OVER THE NORTHERN ROCKIES. THIS SYSTEM WILL CONTINUE EASTWARD PROGRESSION INTO THE DAY SATURDAY AND OVERNIGHT INTO SUNDAY BEFORE IT BECOMES MORE NEGATIVELY TILTED AND LIFTS THROUGH THE UPPER MISSISSIPPI VALLEY INTO THE GREAT LAKES REGION BY MONDAY. THIS LARGER SCALE FEATURE SHOULD BRING ABOUT THE CHANCE OF ELEVATED STORMS FOR SATURDAY MORNING AS A LLJ SHOULD HELP ENHANCE AN AREA OF ISENTROPIC LIFT OVER EASTERN KS. INTO THE DAY, SOUNDINGS DO SUGGEST THAT STORM POTENTIAL MAY BE LIMITED WITH A PRETTY STRONG CAP DEVELOPING OVER THE REGION. THE BETTER CHANCE FOR THUNDERSTORM REDEVELOPMENT WILL BE IN THE LATE AFTERNOON INTO THE EARLY EVENING AS SHEAR PROFILES BECOME A LITTLE MORE ORGANIZED AND WAA INCREASES LOW LEVEL MOISTURE ALONG WITH INSTABILITY OVER THE REGION. SOME POTENTIAL FOR STRONG TO SEVERE STORMS COULD EXIST, BUT STILL TOO FAR OUT TO PINPOINT OVERALL LIKELIHOOD. MODELS SEEM TO BE IN FAIRLY GOOD AGREEMENT FOR THE MOST PART WITH EASTWARD PROGRESSION OF THE TROUGH. THE GFS SOLUTION DOES SEEM TO BE THE MORE AGGRESSIVE OF THE SOLUTIONS THOUGH WITH A DEEPER UPPER LOW AND MORE NORTHERLY PROGRESSION AFTER THE MONDAY MORNING TIME FRAME. IN THE WAKE OF THIS FALL-LIKE LOOKING SYSTEM, WILL BE ANOTHER NICE FEW DAYS AS HEIGHTS RISE AND SUBSIDENCE SETS IN WITH SIGNIFICANT MOISTURE BEING PUSHED SOUTH. HIGH TEMPS COOL BEHIND THE SYSTEM INTO THE UPPER 70S AND ONLY CLIMB INTO THE MID 80S BY TUESDAY. LOWS MEANWHILE COULD FLIRT WITH LOW 50S IN PARTS OF THE AREA BY TUESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1232 AM CDT WED AUG 19 2015 VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...WOLTERS LONG TERM...65/DRAKE AVIATION...SANDERS
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
257 PM CDT WED AUG 19 2015 . DISCUSSION... FOR A THIRD DAY IN A ROW...A LARGE SWATH OF RAIN HAS MOVED NORTHEAST OUT OF THE GULF ACROSS THE CWA AND BROUGHT PLENTIFUL RAIN TO THE AREA. TODAY HAS BEEN LIKELY THE MOST SUBSTANTIAL FROM A COVERAGE AND QPF PERSPECTIVE. UPWARDS OF 2 INCHES HAS FALLEN OVER MANY LOCATIONS WEST OF INTERSTATE 55. FOR THE SHORT TERM RAIN EXPECTATIONS...THE HRRR ONCE AGAIN HAS DONE AN EXCELLENT JOB ON THE TIMING AND MOVEMENT OF RAIN. IT SUGGESTS THAT THE WEAKENING TREND THAT CAN BE SEEN ON RADAR WILL CONTINUE WITH MUCH OF THE CURRENT ACTIVITY DISSIPATED BEFORE 00Z AND SEE NO REASON THIS SOLUTION WONT OCCUR. SOME RESIDUAL SHOWERS MAY LINGER INTO THE EVENING HOURS BUT GENERALLY DRY THROUGH MUCH OF THE NIGHT. AN UPPER LEVEL TROUGH IS IN THE PROCESS OF SWINGING ACROSS THE UPPER MISSISSIPPI VALLEY AND WILL CONTINUE TO DO SO BEFORE MOVING NORTHEAST OVER THE GREAT LAKES THROUGH THURSDAY. A COLD FRONT ASSOCIATED WITH THIS TROUGH IS CURRENTLY MOVING SOUTHEAST ACROSS NORTH TEXAS AND NWRN ARKANSAS. THE BOUNDARY SHOULD BE MOVING SEWD ACROSS NORTHERN LOUISIANA EARLY THURSDAY MORNING. IT DOES APPEAR THAT THE FRONT WILL STALL SOMEWHERE BETWEEN CENTRAL LA TO OVER SOUTHEAST LA. ABUNDANT MOISTURE WHICH IS ALREADY IN PLACE IN COMBINATION WITH CONVERGENCE ALONG THE FRONT WILL BE CONDUCIVE FOR ANOTHER ROUND OF NUMEROUS SHOWERS AND STORMS THURSDAY. SO HAVE INCREASED POPS TO 60 TO 80 PERCENT OVER THE CWA. MAY HAVE SLIGHTLY LESS COVERAGE ON FRIDAY AS THE FRONT DISSOLVES BUT IN THE GRAND SCHEME OF THINGS...WILL STILL BE QUITE A BIT OF SHOWERS AND STORMS DEVELOPING. MEFFER && .AVIATION... A BROAD SHIELD OF LIGHT TO MODERATE RAIN WILL CONTINUE TO BRING LOW CEILINGS BETWEEN 1000 AND 2500 FEET AND REDUCED VISIBILITIES AS LOW AS 3 MILES TO KBTR...KMCB...KHDC THROUGH AROUND 21Z. CONDITIONS SHOULD START TO IMPROVE BACK INTO VFR RANGE AFTER 21Z AS THE PRECIPITATION SHIELD DISSIPATES. ON THE LEADING EDGE OF THE AREA OF RAIN...INCREASED CONVECTIVE INSTABILITY REMAINS IN PLACE...AND KEEP VCTS WORDING IN FOR THE REMAINDER OF THE TERMINALS THROUGH 00Z. EXPECT TO SEE A MIX OF SCATTERED TO BROKEN CEILINGS RANGING FROM 1500 TO 3000 FEET THROUGH THE AFTERNOON HOURS AT THE REMAINING TERMINALS. VFR CONDITIONS WILL BE FOUND AT ALL TERMINALS AFTER 00Z...BUT ANOTHER ELEVATED INVERSION SHOULD ALLOW FOR MVFR CEILINGS AROUND 1500 TO 2500 TO REDEVELOP AROUND 10-11Z TOMORROW MORNING AND PERSIST THROUGH THE REMAINDER OF THE MORNING HOURS. AT KMCB...THE INVERSION WILL BE STRONGER AND RESULT IN SOME IFR AND POSSIBLY LIFR CEILINGS OF 200 TO 300 FEET AND VISIBILITIES DOWN TO 2 MILES OR LESS AT TIMES FROM 10Z THROUGH AROUND 14Z. 32 && .MARINE... HAVE MADE SOME SHORT TERM ADJUSTMENTS TO THE WINDS AND SEAS OVER LAKE PONTCHARTRAIN. LOCALIZED NW WINDS HAVE INCREASED TO A GOOD 15 KNOTS AND LIKELY 3-4 FOOT SEAS OVER THE LAST FEW HOURS FROM SWATH OF RAIN MOVING THROUGH. THINKING IS THAT THESE WINDS MAY MAINTAIN FOR A COUPLE MORE HOURS BEFORE TRENDING BACK DOWN TO 10 KNOTS THIS EVENING. MAIN ISSUE FOR MARINERS THROUGH AT LEAST FRIDAY WILL BE THE DEVELOPMENT OF SCATTERED TO NUMEROUS THUNDERSTORMS...WITH THE POTENTIAL FOR WINDS GUSTING ABOVE 30 KNOTS. OUTSIDE OF THE THUNDERSTORM THREAT...GENERAL ONSHORE FLOW FROM THE SOUTH WILL CONTINUE THROUGH THE END OF THE WORK WEEK. SHOULD BE ENOUGH OF A GRADIENT TODAY TO PRODUCE 10-15 KNOT WINDS OVER THE OPEN WATERS BEFORE RELAXING BELOW 10 KNOTS IN MOST AREAS FOR THURSDAY THROUGH SATURDAY. DO NOT SEE A CLEAN FRONTAL PASSAGE ANY TIME SOON...BUT AS EAST COAST TROF DEEPENS OVER THE WEEKEND...LIGHT OFFSHORE FLOW SHOULD DEVELOP ON SUNDAY. 35 && .DECISION SUPPORT... DSS CODE....GREEN. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...NONE. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE && .PRELIMINARY POINT TEMPS/POPS... MCB 74 89 72 90 / 30 70 20 60 BTR 74 90 74 90 / 30 60 20 60 ASD 76 90 76 90 / 30 70 20 70 MSY 78 88 78 90 / 30 80 20 70 GPT 80 89 78 88 / 30 60 20 50 PQL 78 90 76 89 / 30 60 20 50 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
122 AM EDT WED AUG 19 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 335 PM EDT TUE AUG 18 2015 WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH FROM NRN HUDSON BAY INTO THE NRN PLAINS RESULTING IN A WSW FLOW INTO THE NRN GREAT LAKES. A LINGERNIG AREA OF 700 MB FGEN AND WEAK WAA/ISENTROPIC LIFT CONTINUES TO SUPPORT A PERSISTENT CLUSTER OF SHOWERS OVER SCNTRL UPPER MI INTO EARLY AFTERNOON. UPSTREAM A VIGOROUS SHRTWV ROTATING OVER SD/NE WILL LIFT TOWARD THE UPPER GREAT LAKES TONIGHT BRINGING SHRA TO UPPER MI MAINLY TONIGHT INTO EARLY WED. AT THE SFC...A WEAK FRONTAL BOUNDARY EXTENDED FROM CNTRL IA THROUGH CNTRAL WI INTO CNTRL LWR MI. WITH HIGH PRES OVER NRN ONTARIO...LIGHT NE WINDS PREVAILED ACROSS THE NRN LAKES TODAY. TONIGHT...ATTENTION TURNS TO THE DEVELOPING UNSEASONABLY STRONG LOW PRES SYSTEM MOVING OUT OF THE PLAINS. THE SD/NE SHRTWV WILL SUPPORT A DEEPENING LOW MOVING INTO SRN MN BY 00Z/WED AND THEN INTO NRN WI/SW U.P. BY 12Z/WED AS THE CENTRAL PRESSURE LOWERS NEAR 995 MB APPROACHING RECORD LEVELS FOR THIS TIME OF YEAR. STRONG MOISTURE TRANSPORT AND 305K-310K ISENTROPIC ASCENT WILL BRING AN AREA OF RAIN THROUGH UPPER MI TONIGHT...MAINLY AFTER MIDNIGHT. HOWEVER...THIS TRANSIENT BAND IS EXPECTED TO BRING QPF AMOUNTS OF ONLY 0.25-0.40 INCHES OVER THE CNTRL AND ERN CWA. THE FAR WEST HAS THE POTENTIAL TO GET HIGHER AMOUNTS (0.5 TO ONE INCH) CLOSER TO THE STRONGEST DEEP LAYER QVECTOR CONV AND LIFT WHICH WILL REMAIN TO THE WEST OVER NRN MN AND WRN LAKE SUPERIOR. WITH MODEST MUCAPE VALUES INTO THE 200- 500 J/KG RANGE ONLY ISOLD TSRA ARE EXPECTED. WEDNESDAY...SHOWERS WILL BE EXITING N AND E WED MORNING AHEAD OF THE COLD FRONT AND THEN THE DRY SLOT WITH THE SYSTEM WILL MOVE IN FROM THE SW WED LATE MORNING/AFTERNOON. ALTHOUGH THERE WILL BE STRONG 0-6 KM SHEAR ALONG THE FRONTAL BOUNDARY...AMOUNT OF INSTABILITY (MODELS PROJECT 300-600 J/KG) REMAINS IN QUESTION AS THERE COULD BE CONSIDERABLE CLOUD COVER LINGERING OVER THE AREA. BUT IF SUFFICIENT INSTABILITY DEVELOPS AHEAD/ALONG THE FRONT...THERE COULD BE SOME STRONG TO POSSIBLY SEVERE STORMS FORMING OVER MAINLY THE CENTRAL AND ERN CWA IN THE MORNING. AFTER THE DRY SLOT MOVES INTO MAINLY THE CENTRAL AND ERN CWA EXPECT SHRA TO GENERALLY DISSIPATE IN THE AFTERNOON. WRAP AROUND PRECIP/MOISTURE WITH SYSTEM COULD MOVE INTO WRN UPPER MI LATE IN THE DAY. WED LOOKS WINDY OVER CENTRAL AND ERN UPPER MI WITH S-SW WINDS GUSTING TO 25-30 MPH. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 251 PM EDT TUE AUG 18 2015 THE ANOMALOUS UPPER TROUGH AND SURFACE LOW (AROUND 3-4 SIGMA) WILL BE CENTERED BETWEEN DULUTH AND ISLE ROYALE AT THE START OF THE LONG TERM FORECAST. THESE FEATURES WILL BE SLOWLY LIFTING TO THE NORTHEAST THROUGH THURSDAY...BRINGING THE POTENTIAL FOR RAIN SHOWERS AND BREEZY CONDITIONS TO THE AREA DURING THAT PERIOD. STARTING OFF THE PERIOD...THE MID LEVEL DRY SLOT WILL BE OVER THE CENTRAL AND EASTERN U.P. AND DON/T EXPECT MUCH MORE THAN LOW CLOUDS FOR THE EVENING. BUT OVER THE WEST...WRAP AROUND MOISTURE WILL LEAD TO SCATTERED/NUMEROUS SHOWERS WILL BE OCCURRING AND WILL LIKELY SEE SOME ASSISTANCE FROM TERRAIN ENHANCEMENT WITH THE WEST-NORTHWEST WINDS BEHIND THE SURFACE TROUGH THAT WILL BE LOCATED OVER THE CENTRAL U.P. AT 06Z THURSDAY. AS THAT LOW LIFTS TO THE NORTHEAST OVERNIGHT WEDNESDAY INTO THURSDAY...EXPECT THE SHOWERS TO SHIFT EASTWARD BEHIND THE TROUGH AND MOVE OVER THE CENTRAL/EASTERN U.P. ACCUMULATIONS WILL BE LIGHTER THAN OVER THE WEST WITH LESS TERRAIN INFLUENCE...BUT SHOULD STILL SEE A FEW HUNDREDTHS BY LATE THURSDAY AFTERNOON. WITH THE UPPER LOW QUICKLY MOVING TO THE NORTH THURSDAY AFTERNOON INTO THURSDAY NIGHT...SHOULD SEE THE SHOWER COVERAGE QUICKLY DIMINISH AS DRIER AIR ASSOCIATED WITH A SURFACE RIDGE MOVING NORTHEAST INTO THE AREA. HAVE FOLLOWED THAT IDEA BOTH WITH THE POPS AND CLOUD COVER THURSDAY AFTERNOON AND EVENING. IN FACT...SOME OF THE AREAS NEAR THE WISCONSIN BORDER MAY HAVE THE LOW CLOUDS SCATTER OUT BY EARLY AFTERNOON. IN ADDITION TO THE RAIN...EXPECT WINDS TO INCREASE OVER AT LEAST THE WESTERN HALF OF THE CWA ON WEDNESDAY NIGHT. THE DIFFERENCES IN THE MODELS LEADS TO SOME UNCERTAINTY IN THE STRENGTH...BUT IT STILL APPEARS THAT GUSTS UP TO 30KTS ARE POSSIBLE OVER THE KEWEENAW. FOR THE REST OF THE AREA...EXPECT GUSTS IN THE 20-25KT RANGE ON THURSDAY. THE HIGH PRESSURE RIDGE WILL BE NEAR THE AREA (FROM A HIGH IN THE OHIO RIVER VALLEY) THROUGH FRIDAY NIGHT...BUT EXPECT THE GRADIENT TO TIGHTEN THROUGH THAT PERIOD AS ANOTHER LOW DEVELOPS IN THE NORTHERN PLAINS. THAT GRADIENT AND PLENTY OF SUNSHINE SHOULD LEAD TO DECENT MIXING ON FRIDAY (AROUND 800MB)...RAISING TEMPERATURES TO NORMAL OR SLIGHTLY ABOVE NORMAL VALUES UNDER OCCASIONALLY GUSTY SOUTHWESTERLY WINDS (17-23KTS). WITH THE UPPER TROUGH AND SURFACE LOW STILL NEAR THE NORTHERN PLAINS AND MOVING INTO THE UPPER MISSISSIPPI VALLEY...EXPECT A SIMILAR DAY ON SATURDAY. HAVE REMOVED THE POPS OVER THE WEST FOR SATURDAY AND WILL KEEP SKIES MOSTLY SUNNY. SINCE THE TIGHTENING GRADIENT WILL REMAIN IN PLACE AHEAD OF THE LOW...EXPECT WINDS TO BE A LITTLE GUSTIER THAN FRIDAY (UP TO 25KTS) AND TEMPERATURES TO BE A FEW DEGREES WARMER. THE UPPER TROUGH FOR THE SECOND HALF OF THE WEEKEND WILL MOVE THROUGH THE UPPER GREAT LAKES REGION OVERNIGHT SATURDAY THROUGH SUNDAY EVENING. MEANWHILE...THE SURFACE LOW WILL LIFT NORTH-NORTHEAST FROM NORTHWEST MINNESOTA TO FAR NORTHERN ONTARIO. THIS WILL LEAD TO A SHARP COLD FRONT MOVING EAST ACROSS THE AREA ON SUNDAY. MODELS SEEM TO BE FOCUSING ON LATE SATURDAY NIGHT AND SUNDAY MORNING FOR THE FRONT TO MOVE THROUGH AND WILL FOCUS THE HIGHEST POPS DURING THAT PERIOD (LOW LIKELY) AND QUICKLY RAMP UP/DOWN ON BOTH SIDES. MODELS NOT SHOWING A WHOLE LOT OF INSTABILITY AHEAD OF THE FRONT (MUCAPE VALUES ONLY UP TO 500 J/KG)...SO THINK THAT THE THUNDER THREAT WILL BE LIMITED AND WILL CAP AT CHANCES. THE COLD FRONT WILL USHER IN ANOTHER PERIOD OF BELOW NORMAL TEMPERATURES FOR THE START OF NEXT WEEK AS HIGH PRESSURE BUILDS OVER THE AREA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 122 AM EDT WED AUG 19 2015 UNUSUALLY DEEP LOW PRES FOR AUG WILL MOVE FROM SW MN TO NCNTRL LAKE SUPERIOR DURING THIS FCST PERIOD. ABUNDANT MOISTURE AND SHRA STREAMING N WITH THIS SYSTEM WILL LEAD TO LIFR CONDITIONS AT KIWD/KCMX/KSAW OVERNIGHT AHEAD OF WARM FRONT LIFTING N. PASSAGE OF WARM FRONT/OCCLUDING FRONT WILL THEN BRING IMPROVING CONDITIONS THIS MORNING/EARLY AFTN. FARTHEST FROM SFC LOW...KSAW WILL SEE BETTER DRYING AND POTENTIAL FOR IMPROVEMENT TO VFR IN THE AFTN. KCMX MAY BRIEFLY REACH VFR...BUT MVFR IS MORE LIKELY TO PREVAIL THRU THE AFTN. KIWD WILL REMAIN MVFR. THERE IS SOME POTENTIAL FOR ISOLD TSTMS THIS AFTN IN NW AND CNTRL UPPER MI...BUT WITH CONSIDERABLE UNCERTAINTY IN WHERE TSTMS WILL DEVELOP IF THEY DO...NO TS MENTION WAS INCLUDED IN FCST. WINDS WILL BECOME GUSTY AFTER FROPA... ESPECIALLY AT KSAW WHERE GUSTS TO AROUND 25KT ARE EXPECTED. CONDITIONS WILL DETERIORATE AGAIN THIS EVENING AS LOW-LEVEL MOISTURE WRAPS BACK INTO THE AREA AFTER THE LOW PASSES. KIWD SHOULD FALL TO LIFR...KCMX TO IFR AND KSAW TO MVFR. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 327 PM EDT TUE AUG 18 2015 AS LOW PRES ORGANIZES AND STRENGTHENS OVER THE PLAINS THIS EVENING ...NE WINDS WILL BEGIN TO INCREASE...ESPECIALLY OVER WRN LAKE SUPERIOR WHERE GUSTS SHOULD REACH 30KT LATE AFTN/EARLY EVENING. MAY EVEN BE A FEW GALE GUSTS NEAR APOSTLE ISLANDS EARLY EVENING. THIS LOW WILL BECOME UNSEASONABLY DEEP FOR AUG AS IT LIFTS ACROSS WRN LAKE SUPERIOR WED AFTERNOON. 20-30KT WINDS ARE EXPECTED OVER MUCH OF THE LAKE TONIGHT INTO WED. MAY SEE GALE FORCE GUSTS OVER FAR WRN LAKE SUPERIOR IN THE NE WINDS AHEAD OF THE LOW TONIGHT AND THEN IN THE WESTERLY WINDS ACROSS WRN AND CENTRAL LAKE SUPERIOR ON THU AS THE LOW LIFTS N OF THE AREA. WINDS WILL DIMINISH TO UNDER 20KT BY FRI...AND THEN BEGIN TO INCREASE SOME AGAIN ON SAT AHEAD OF THE NEXT COLD FRONT MOVING OUT ACROSS THE PLAINS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...SRF AVIATION...ROLFSON MARINE...VOSS
AREA FORECAST DISCUSSION
NWS DULUTH MN
642 PM CDT THU AUG 20 2015 .UPDATE... ISSUED AT 636 PM CDT THU AUG 20 2015 UPDATED AVIATION SECTION BELOW. CLOUD COVER FORECAST IS CURRENTLY ON TRACK AND EXPECT TO LOSE A LOT OF THE REMAINING CLOUD COVER BETWEEN NOW AND 02Z...SETTING US UP FOR A FAIRLY GOOD RADIATIONAL COOLING NIGHT. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 330 PM CDT THU AUG 20 2015 SHOWERS/DRIZZLE ENDING ACROSS THE ARROWHEAD EARLY THIS AFTERNOON GIVING WAY TO SUNNY AND JUST BELOW SEASONABLE TEMPERATURES ACROSS THE REGION. CLEAR SKIES AND NEAR-CALM WIND TONIGHT WITH A HIGH PRESSURE BUILDING IN WILL LEAD TO COOL OVERNIGHT LOWS. SUNNY AND WARMER ON FRIDAY WITH HIGHS NEAR 80. ON THE SYNOPTIC SCALE THE BROAD LOW PRESSURE SYSTEM THAT BROUGHT INTENSE RAINFALL TO THE REGION EARLIER THIS WEEK IS FINALLY DEPARTING TO THE NORTHEAST. BEHIND THIS SOME LOW-LEVEL RIDGING WILL BUILD IN TO THE UPPER MIDWEST AS A HIGH PRESSURE BUILDS FROM THE TENNESSEE TO OHIO RIVER VALLEY. WARM AIR ADVECTION WILL RAMP UP DUE TO WEST/SOUTHWESTERLY WINDS AT LOW LEVELS TONIGHT INTO TOMORROW. IN ADDITION...A WEAK WARM FRONT ON THE LEADING EDGE OF THE WARM AIR ADVECTION WILL MOVE ACROSS MANITOBA INTO NORTHWEST ONTARIO...WHICH MAY GRAZE THE BORDERLAND WITH SOME SHOWERS OVERNIGHT. WHILE THERE IS NOT MUCH SUPPORT FROM THE GLOBAL MODEL SUITE AS FAR AS QPF GOES...MOST MODELS INDICATE THE NECESSARY FORCING WILL BE THERE FOR A FEW SHOWERS. THE LATEST HRRR RUNS ARE ALSO SUPPORTIVE OF THIS IDEA...SO INCLUDED SOME LOW POPS UP ALONG THE INTERNATIONAL FALLS REGION. ON FRIDAY THE LOW-LEVEL RIDGING FLATTENS OUT WITH WEST- SOUTHWEST FLOW ALOFT RESULTING IN CONTINUED WARM AIR ADVECTION. FOR REFERENCE...THE 850MB TEMP FROM THIS MORNINGS 12Z SOUNDING AT INTERNATIONAL FALLS WAS 3.1C...AND THE MODEL CONSENSUS IS FOR THIS TO RISE TO ABOUT 18C BY FRIDAY AFTERNOON. TONIGHT...GRADUALLY CLEARING SKIES WITH PATCHY FOG POSSIBLE. WINDS BECOMING NEAR-CALM IN THE EVENING WHICH SHOULD ALLOW FOR FOG TO DEVELOP...ESPECIALLY IN NORTHWEST WISCONSIN WHERE THE HEAVIEST RAINFALL HAS FALLEN OVER THE PAST FEW DAYS. GUIDANCE NOT VERY SUPPORTIVE OF THE FOG IDEA WHICH IS PROBABLY DUE TO THE DRIER AIR MOVING IN FROM THE WEST...BUT WITH A WEAK RIDGE OVER THE REGION TEMPS WILL FALL RAPIDLY AND AT LEAST PATCHY RADIATION FOG SHOULD DEVELOP. LATER IN THE NIGHT...AFTER MIDNIGHT...SOME HIGH CLOUDS MAY MOVE IN ACROSS FAR NORTH-CENTRAL MINNESOTA...AND POSSIBLY A SHOWER OR TWO IN THE INTERNATIONAL FALLS REGION. FOG MAY DISSIPATE BEFORE SUNRISE IF WINDS PICK UP BY EARLY FRIDAY MORNING...THIS WILL DEPEND ON THE TIMING OF THE RIDGE AXIS BUT THINKING BY SUNRISE FOG SHOULD BE GONE EVERYWHERE EXCEPT FOR NORTHERN WISCONSIN NEAR THE UP. LOWS IN THE LOW/MID 40S TO LOW 50S. FRIDAY...MOSTLY SUNNY...WARM...AND BREEZY. WINDS OUT OF THE SOUTH AT 10 TO 15 MPH WITH GUSTS TO NEAR 25 MPH. THERE MAY BE AN ISOLATED SHOWER IN THE MORNING ACROSS THE BORDERLAND...BUT OTHERWISE DRY. HIGHS IN THE UPPER 70S TO LOW 80S. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 330 PM CDT THU AUG 20 2015 THE MAIN CONCERN FOR THE EXTENDED IS THE THREAT FOR SEVERE WEATHER SATURDAY AFTERNOON AND NIGHT. THE SOUTHERLY FLOW CONTINUES ACROSS THE FORECAST AREA FRIDAY NIGHT OUT AHEAD OF THE SYSTEM. THE NAM AND ECMWF ARE SIMILAR WITH TAKING THE CENTER ACROSS NORTHERN MN WITH THE GFS KEEPING NORTH OF THE INTERNATIONAL BORDER. BASED ON CURRENT TRENDS AND PERFORMANCE OF THE MODELS WITH THE LAST STORM...WILL GO WITH A MIXTURE OF NAM/ECMWF FOR SOLUTION. THE COLD FRONT WILL ENTER WESTERN LATE SATURDAY MORNING AND ACROSS THE TWIN PORTS LATE SATURDAY EVENING. THUNDERSTORMS WILL DEVELOP SATURDAY MORNING IN WRN MN AND MOVE EAST DURING THE DAY. SPC DAY 3 OUTLOOK INDICATES A SLIGHT RISK MAINLY EAST OF HIGHWAY 53/I-35 IN MN WITH MARGINAL RISK ACROSS MOST OF THE REST OF THE FORECAST AREA. AS INDICATED BY THE MID SHIFT...THERE WILL BE A RISK FOR SEVERE THUNDERSTORMS IN THE AFTERNOON BUT MAY BE FOCUSED FURTHER WEST IN MN. IT STILL LOOKS LIKE A MCS MAY DEVELOP LATER IN THE AFTERNOON. IT WILL BE ANOTHER HEAVY RAIN EVENT WITH PWATS IN THE 1.5 TO 2.0 INCHES EXPECTED ACROSS THE FORECAST AREA. STORM TOTAL QPF FORECAST IS FOR 1-1.5 INCHES FROM INL TO BRD WITH 0.50 TO 0.75 INCHES FURTHER EAST BY SUNDAY MORNING. SIMILAR TO THE PAST SYSTEM...MUCH COOLER AIR WILL PUSH INTO THE REGION WITH SOME SHOWERS ON SUNDAY. HIGHS WILL BE IN THE 60S INTO THE MIDDLE OF THE WEEK WITH 45-55 AT NIGHT. A SHORTWAVE WILL PASS THROUGH THE REGION ON THURSDAY BRINGING A POSSIBILITY OF A THUNDERSTORM. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 636 PM CDT THU AUG 20 2015 SURFACE RIDGE OF HIGH PRESSURE BUILDING ACROSS THE AREA THIS EVENING...THEN SOUTHWEST RETURN FLOW TO SET UP FOR TOMORROW. CURRECT CUMULUS CLOUDS TO DISSIPATE BY 02Z THIS EVENING LEAVING VFR CONDITIONS WITH DIMINISHING WINDS. FOG POSSIBLE AT TERMINALS AFTER RECENT RAINFALL...SO HAVE PUT IN SOME IFR VISIBILITIES IN TEMPO GROUPS FOR NOW. WILL RE-EVALUATE HERE FOR THE 06Z SET AND CAN PUT A BIT MORE CERTAINTY IN THEN. FOG TO DISSIPATE IN THE 11-14Z TIME RANGE AND RETURN TO VFR CONDITIONS. && .PRELIMINARY POINT TEMPS/POPS... DLH 51 78 62 79 / 0 0 20 40 INL 47 82 60 80 / 20 20 20 70 BRD 52 82 64 81 / 0 0 20 70 HYR 48 79 62 81 / 0 10 10 10 ASX 47 80 61 84 / 0 0 10 10 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. LS...NONE. && $$ UPDATE...LE SHORT TERM...JJM LONG TERM...STEWART AVIATION...LE
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
1121 PM CDT TUE AUG 18 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 258 PM CDT TUE AUG 18 2015 VERY POWERFUL LOW PRESSURE MOVING FROM SOUTHWEST MN TO THE ARROWHEAD REGION BY WEDNESDAY EVENING. IT IS VERY RARE TO SEE SUCH A STRONG LOW PRESSURE SYSTEM IN THE SUMMER. IN FACT IT MAY WELL RIVAL THE LOW PRESSURE RECORD FOR MSP. THE HRRR AND HOPWRF ARE IN GOOD AGREEMENT AND HAVE DONE WELL THE LAST FEW HOURS. RADAR AND OBS SUPPORT THE IDEA OF LESS PRECIPITATION IN TERMS OF AMOUNTS AND LESS CHANCES FOR THUNDER AFTER 02Z THIS EVENING ACROSS THE AREA. DRY SLOT REALLY TOOK OVER FOR THIS EVENT IN SRN MN. EXPECT THE COMMA HEAD WRAP-AROUND PRECIPITATION TO AFFECT WESTERN MN LATE THIS AFTERNOON AND SLOWLY LIFT EAST AND NORTH THROUGH THE EVENING AND OVERNIGHT HOURS. MAIN PRECIPITATION WILL BE OVER WRN MN AND EXTENDING TO THE ARROWHEAD. WE CAN EXPECT SCATTERED RAIN AND AN ISOLATED SHOWER OVER CENTRAL MN INTO WRN WI THROUGH THE OVERNIGHT HOURS...MAYBE DRIZZLE. RAIN SHOULD DIMINISH TOWARD MORNING AND THEN SEE AN INCREASE BY MID DAY. STRONG WINDS WILL MOVE IN OVERNIGHT WITH GUSTS INTO THE MID 30 MPH RANGE WEDNESDAY AFTERNOON WITH MOSTLY CLOUDY SKIES AND COOL TEMPERATURES. VERY MUCH LIKE OCTOBER. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 258 PM CDT TUE AUG 18 2015 PICKING UP THE FORECAST WEDNESDAY NIGHT...THE FOCUS REMAINS GETTING THIS INCREDIBLY STRONG MID AUGUST SYNOPTIC SCALE STORM SYSTEM OUT OF HERE. BY THIS POINT...THE SURFACE LOW SHOULD BE POSITIONED OVER WESTERN LAKE SUPERIOR AND SLIDING NORTHEAST. IT WILL BE ESSENTIALLY VERTICALLY STACKED AND BEGIN WEAKENING OVERNIGHT. THE HIGHLY AMPLIFIED 500MB TROUGH WILL INTRODUCE DRY NORTHWESTERLY FLOW INTO WESTERN MN WHICH WILL EXPAND EASTWARD BY THURSDAY MORNING. DRY AIR WILL ACCOMPANY THE NORTHWESTERLY FLOW...SO WE`LL SEE THE CLOUDS BEGIN TO CLEAR FROM WEST TO EAST OVERNIGHT IN WESTERN MN...THROUGH WESTERN WI BY MIDDAY THURSDAY. WITH CLEARING SKIES...AND THE LOW MOVING OFF...WE`LL SEE TEMPERATURES REBOUND INTO THE MID 70S FOR HIGHS. WESTERLY WINDS AT THE SURFACE OF 10-15 MPH ARE EXPECTED THURSDAY...SO MUCH LESS WINDY THAN WEDNESDAY. BY FRIDAY...A LOW PRESSURE SYSTEM WILL BE DEVELOPING NEAR MONTANA...AND WE WILL BE ON THE BACK SIDE OF THE SURFACE RIDGE AXIS ASSOCIATED WITH A SURFACE HIGH SLIDING EAST FROM THE CENTRAL PLAINS TOWARD THE OHIO RIVER VALLEY....WHICH MEANS AN INCREASE IN SOUTHERLY WINDS IS EXPECTED. WIND SPEEDS ARE FORECAST TO BE AROUND 15-20 MPH WITH GUSTS OVER 20...AND TEMPERATURES WILL WARM INTO THE LOW 80S ONCE AGAIN. MAYBE MORE NOTICEABLY...WILL BE THE DEW POINTS RISING INTO THE MID 60S BY FRIDAY AFTERNOON. FOR THE WEEKEND...THE AFOREMENTIONED SYSTEM IN MONTANA WILL BE THE FEATURE OF CONCERN. THE SURFACE LOW IS EXPECTED TO PROGRESS EASTWARD ALONG THE INTERNATIONAL BORDER SATURDAY THROUGH SUNDAY...BUT A NORTH-SOUTH ORIENTED COLD FRONT WILL BE THE FOCUS FOR SHOWER AND THUNDERSTORM ACTIVITY TO DEVELOP IN OUR AREA...MOST LIKELY SATURDAY AFTERNOON THROUGH THE OVERNIGHT HOURS. THIS SHOULD BE A PROGRESSIVE LINE OF THUNDERSTORMS ALONG THE BOUNDARY...SO BY SUNDAY MORNING WE SHOULD BE BACK IN DRIER NORTHWESTERLY FLOW AND COOLER TEMPERATURES. WILL HAVE TO SEE HOW THIS SYSTEM DEVELOPS IN THE FUTURE MODEL GUIDANCE AS TIMING ISSUES ARE QUITE COMMON THIS FAR OUT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1120 PM CDT TUE AUG 18 2015 THE LOW PRESSURE IS CENTERED NEAR RWF WITH A WARM FRONT EXTENDING TO MSP/RNH/EAU. SOUTH OF THE FRONT...CONDITIONS ARE MAINLY VFR BUT MVFR/IFR CIGS ARE BEGINNING TO DEVELOP IN POCKETS OF SWRN WI AND SERN MN. FOUR OF THE SIX TAF LOCATIONS ARE NEAR THE WARM FRONT WHICH LEADS TO A LOW CONFIDENCE FORECAST FOR MUCH OF THE NIGHT AS THE WARM FRONT LINGERS NEARBY. EVENTUALLY THE LOW WILL TRACK THROUGH AND MOISTURE ON ITS BACKSIDE WILL BRING CIGS INTO THE MVFR/IFR RANGE INTO MUCH OF WEDNESDAY. KMSP...CONDITIONS HAVE RANGED FROM IFR AND NEARLY LIFR NORTH OF THE FRONT TO VFR WITH THE PASSAGE OF THE WARM FRONT. DON/T BELIEVE THE FRONT WILL GO TOO FAR WHICH WILL RESULT IN HIGHLY VARIABLE CONDITIONS TONIGHT. PREVAILING VFR WITH INSTANCES OF IFR EXPECTED...BEFORE MVFR/IFR CONDITIONS TAKE HOLD BEGINNING LATE TONIGHT. /OUTLOOK FOR KMSP/ THU...VFR. WINDS W 10-15 KTS. FRI...VFR. WINDS S 10-15 KTS. SAT...VFR WITH MVFR/TSRA POSSIBLE LATE. WIND S AT 15G20 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...DRL LONG TERM...SPD AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
402 PM CDT WED AUG 19 2015 .SHORT TERM...(This Evening through Friday Night) Issued at 400 PM CDT WED AUG 19 2015 Can`t beat this weather...October in mid August. Better enjoy it while it lasts. Deep upper trough extending from MN through eastern KS into OK will continue tracking east tonight. Water vapor imagery shows a weak vorticity max dropping down the back side of the trough across western IA. Widely scattered instability showers have popped as a result. HRRR trend supports low-end slight chance PoPs over northern MO until about sunset. Most likely only sprinkles. Otherwise, heating based stratocu cloud cover from NE into the CWA should dissipate with loss of daytime heating and leave skies cloud free by midnight. Could be flirting with record lows tomorrow morning. MCI record min is 53 and STJ is 48. Temperatures will rebound, but remain below average on Thursday, before returning closer to seasonal on Friday. Warming will be the result of the cooler/drier air being pulled away as the upper trough moves east vs return flow from a retreating surface high. But even the warm-up will be pleasant by summer standards as dewpoints will remain in the 50s on Thursday and only increase into the lower 60s on Saturday. Sure beats the upper 60s to lower 70s which occur so often this time of year. Will leave the forecast rain-free through Friday except for a token slight chance PoP over far northwest MO late Thursday night. Rain chances begin to ramp up late Friday night into Saturday morning as stronger isentropic ascent tied to increasing low-level moisture and development of the nocturnal low-level jet. .LONG TERM...(Saturday through Wednesday) Issued at 400 PM CDT WED AUG 19 2015 The GFS, European, and Canadian models are all in good agreement that this weekend will see a pattern very similar to the pattern that moved through the area the past couple days. The models depict an upper level trough will develop and slide east over the northern states through the weekend. An associated cold front will advance across the Central Plains ahead of the trough. The models show the best chance for storms will be Saturday night into Sunday as the upper level trough moves over the Dakotas and the cold front moves through the forecast area. Initially, convection will occur across MN and IA earlier Saturday evening before spreading further south into the forecast area as the cold front interacts with increasing moisture ahead of and along the front. Severe potential would be limited if showers or cloud cover linger throughout the day on Saturday as these could restrict surface heating and convection later in the evening. Just like today, showers could linger on Sunday morning after the passage of the cold front. Also, temperatures will be lower than normal for August on Sunday into Monday, and dry conditions will prevail after the lingering showers dissipate on Sunday. Temperatures gradually increase throughout the early part of the work week as upper level high pressure slowly builds over the Plains. && .AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon) Issued at 1242 PM CDT WED AUG 19 2015 A few light showers/sprinkles possible over parts of west central/central MO this afternoon as well as north central and northeast MO. Otherwise, VFR conditions expected except at KSTJ where local effects due to temperature spread between river water and air should result in generation of steam fog. Could see brief periods of LIFR visibilities/ceilings during the pre-dawn hours. && .CLIMATE... Issued at 400 PM CDT WED AUG 19 2015 Record low temperature/date for August 19th... Kansas City (MCI) 53/1950 St. Joseph (STJ) 48/1981 && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ SHORT TERM...MJ LONG TERM...HEC AVIATION...MJ CLIMATE...MJ
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1216 PM CDT WED AUG 19 2015 .UPDATE: ISSUED AT 829 AM CDT WED AUG 19 2015 NORTHWARD EXPANSION OF PRECIPITATION SHIELD HAS NOT MATERIALIZED THIS MORNING AS PREVIOUSLY FORECAST. HAVE REMOVED THUNDER AS CONVECTION IS NOW LIMITED TO ARKANSAS AND ITS THAT SOUTHWARD PUSH ON THE LEADING EDGE THAT IS LIKELY RESPONSIBLE FOR THE DRIER CONDITIONS ACROSS OUR AREA. STILL EXPECT THAT WE WILL SEE ISOLATED TO SCATTERED SHOWERS DEVELOP THIS AFTERNOON AS THE SHORTWAVE MOVES ACROSS THE AREA...BUT WIDESPREAD PRECIPITATION SHOULD BE LIMITED TO SOUTHERN MISSOURI AND ILLINOIS. CVKING && .SHORT TERM: (THROUGH TONIGHT) ISSUED AT 306 AM CDT WED AUG 19 2015 A STOUT COLD FRONT WAS SWEEPING THROUGH THE REGION EARLY THIS MORNING. AT 08Z, THE FRONT STRETCHED FROM ITS PARENT CYCLONE OVER SRN MN SEWD THROUGH ERN IA, THEN CURVED BACK SWWD THROUGH MO AND INTO SERN KS AND NRN OK. WATER VAPOR IMAGERY AND RAP PV ANALYSES DEPICT A SECONDARY VORT MAX DIVING INTO THE BASE OF THE TROUGH, WHICH IS CONSISTENT WITH MODEL GUIDANCE. LARGE SCALE ASCENT AHEAD OF THIS FEATURE WILL SUPPORT PERIODS OF SH/TS TODAY INTO TONIGHT. PRECIPITATION SHOULD TAPER OFF TONIGHT IN THE WAKE OF THE AFOREMENTIONED VORT MAX. WED NIGHT/EARLY THU MORNING LOWS IN THE 50S WILL BE AROUND 10 DEGREES BELOW AVERAGE. KANOFSKY .LONG TERM: (THURSDAY THROUGH TUESDAY) ISSUED AT 306 AM CDT WED AUG 19 2015 SURFACE HIGH PRESSURE BUILDS INTO THE SOUTHERN PLAINS ON THU AND GRADUALLY SHIFTS EWD WITH TIME. THIS WILL KEEP COOLER/DRIER CONDITIONS AND WESTERLY WINDS IN PLACE ACROSS MOST OF THE CWA ON THU/FRI UNTIL THE SURFACE HIGH HAS SHIFTED FAR ENOUGH EAST FOR WINDS TO TURN SLY AROUND ITS BACK SIDE. RETURN FLOW SETS UP FARTHER WEST ACROSS THE PLAINS ON THU NIGHT/FRI AHEAD OF THE NEXT LOW PRESSURE SYSTEM WHICH WILL BE CROSSING FROM THE PACIFIC NW INTO THE PLAINS OVER THE WEEKEND. THIS SYSTEM WILL BRING THE NEXT CHANCE FOR SH/TS TO THE LSX CWA OVER THE WEEKEND. ANOTHER STOUT COLD FRONT IS EXPECTED TO MOVE ACROSS THE CWA ON SUN AND THEN SETTLE SOUTH OF THE CWA EARLY NEXT WEEK. TEMPERATURES WILL DIP BELOW AVERAGE AGAIN IN THE WAKE OF THIS FRONT. KANOFSKY && .AVIATION: (FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1215 PM CDT WED AUG 19 2015 EXPECT VFR CONDITIONS WITH ISOLATED TO SCATTERED SHOWERS THIS AFTERNOON AS THE UPPER LEVEL TROF SWINGS ACROSS THE AREA. CLEARING SKIES TONIGHT WITH WEST/NORTHWEST WIND CONTINUING. SPECIFICS FOR KSTL: EXPECT VFR CONDITIONS WITH A FEW SHOWERS THIS AFTERNOON. CVKING && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
834 AM CDT WED AUG 19 2015 .UPDATE: ISSUED AT 829 AM CDT WED AUG 19 2015 NORTHWARD EXPANSION OF PRECIPITATION SHIELD HAS NOT MATERIALIZED THIS MORNING AS PREVIOUSLY FORECAST. HAVE REMOVED THUNDER AS CONVECTION IS NOW LIMITED TO ARKANSAS AND ITS THAT SOUTHWARD PUSH ON THE LEADING EDGE THAT IS LIKELY RESPONSIBLE FOR THE DRIER CONDITIONS ACROSS OUR AREA. STILL EXPECT THAT WE WILL SEE ISOLATED TO SCATTERED SHOWERS DEVELOP THIS AFTERNOON AS THE SHORTWAVE MOVES ACROSS THE AREA...BUT WIDESPREAD PRECIPITATION SHOULD BE LIMITED TO SOUTHERN MISSOURI AND ILLINOIS. CVKING && .SHORT TERM: (THROUGH TONIGHT) ISSUED AT 306 AM CDT WED AUG 19 2015 A STOUT COLD FRONT WAS SWEEPING THROUGH THE REGION EARLY THIS MORNING. AT 08Z, THE FRONT STRETCHED FROM ITS PARENT CYCLONE OVER SRN MN SEWD THROUGH ERN IA, THEN CURVED BACK SWWD THROUGH MO AND INTO SERN KS AND NRN OK. WATER VAPOR IMAGERY AND RAP PV ANALYSES DEPICT A SECONDARY VORT MAX DIVING INTO THE BASE OF THE TROUGH, WHICH IS CONSISTENT WITH MODEL GUIDANCE. LARGE SCALE ASCENT AHEAD OF THIS FEATURE WILL SUPPORT PERIODS OF SH/TS TODAY INTO TONIGHT. PRECIPITATION SHOULD TAPER OFF TONIGHT IN THE WAKE OF THE AFOREMENTIONED VORT MAX. WED NIGHT/EARLY THU MORNING LOWS IN THE 50S WILL BE AROUND 10 DEGREES BELOW AVERAGE. KANOFSKY .LONG TERM: (THURSDAY THROUGH TUESDAY) ISSUED AT 306 AM CDT WED AUG 19 2015 SURFACE HIGH PRESSURE BUILDS INTO THE SOUTHERN PLAINS ON THU AND GRADUALLY SHIFTS EWD WITH TIME. THIS WILL KEEP COOLER/DRIER CONDITIONS AND WESTERLY WINDS IN PLACE ACROSS MOST OF THE CWA ON THU/FRI UNTIL THE SURFACE HIGH HAS SHIFTED FAR ENOUGH EAST FOR WINDS TO TURN SLY AROUND ITS BACK SIDE. RETURN FLOW SETS UP FARTHER WEST ACROSS THE PLAINS ON THU NIGHT/FRI AHEAD OF THE NEXT LOW PRESSURE SYSTEM WHICH WILL BE CROSSING FROM THE PACIFIC NW INTO THE PLAINS OVER THE WEEKEND. THIS SYSTEM WILL BRING THE NEXT CHANCE FOR SH/TS TO THE LSX CWA OVER THE WEEKEND. ANOTHER STOUT COLD FRONT IS EXPECTED TO MOVE ACROSS THE CWA ON SUN AND THEN SETTLE SOUTH OF THE CWA EARLY NEXT WEEK. TEMPERATURES WILL DIP BELOW AVERAGE AGAIN IN THE WAKE OF THIS FRONT. KANOFSKY && .AVIATION: (FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 634 AM CDT WED AUG 19 2015 RAIN SHOWERS ACROSS SOUTHWEST MISSOURI WILL SPREAD NORTHEAST DURING THE MORNING IMPACTING KCOU AND THE ST. LOUIS AREA TERMINALS, WITH SHOWERS BECOMING MORE SPOTTY IN THE AFTERNOON. FUTHER NORTH WE SHOULD SEE SCATTERED SHOWERS DEVELOP IN RESPONSE TO HEATING AND THUS THE COVERAGE AND DIRECT IMPACT AT KUIN IS LESS CERTAIN HENCE ONLY MENTIONED VCSH. FLIGHT CONDITIONS SHOULD BE IN THE HIGH-END MVFR TO LOW-END VFR RANGE MUCH OF THE DAY WITH CLEARING SKIES AREAWIDE BY EARLY THIS EVENING. SPECIFICS FOR KSTL: RAIN SHOWERS WILL SPREAD FROM SOUTHWEST MISSOURI INTO KSTL BY MID-MORNING. SHOWERS SHOULD PERSIST THROUGH EARLY AFTERNOON AND THEN BECOME MORE SPOTTY BY LATE AFTERNOON. EXPECT FLIGHT CONDITIONS IN THE HIGH-END MVFR TO LOW-END VFR RANGE MUCH OF THE DAY WITH CLEARING SKIES EARLY THIS EVENING. GLASS && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
648 AM CDT WED AUG 19 2015 .SHORT TERM: (THROUGH TONIGHT) ISSUED AT 306 AM CDT WED AUG 19 2015 A STOUT COLD FRONT WAS SWEEPING THROUGH THE REGION EARLY THIS MORNING. AT 08Z, THE FRONT STRETCHED FROM ITS PARENT CYCLONE OVER SRN MN SEWD THROUGH ERN IA, THEN CURVED BACK SWWD THROUGH MO AND INTO SERN KS AND NRN OK. WATER VAPOR IMAGERY AND RAP PV ANALYSES DEPICT A SECONDARY VORT MAX DIVING INTO THE BASE OF THE TROUGH, WHICH IS CONSISTENT WITH MODEL GUIDANCE. LARGE SCALE ASCENT AHEAD OF THIS FEATURE WILL SUPPORT PERIODS OF SH/TS TODAY INTO TONIGHT. PRECIPITATION SHOULD TAPER OFF TONIGHT IN THE WAKE OF THE AFOREMENTIONED VORT MAX. WED NIGHT/EARLY THU MORNING LOWS IN THE 50S WILL BE AROUND 10 DEGREES BELOW AVERAGE. KANOFSKY .LONG TERM: (THURSDAY THROUGH TUESDAY) ISSUED AT 306 AM CDT WED AUG 19 2015 SURFACE HIGH PRESSURE BUILDS INTO THE SOUTHERN PLAINS ON THU AND GRADUALLY SHIFTS EWD WITH TIME. THIS WILL KEEP COOLER/DRIER CONDITIONS AND WESTERLY WINDS IN PLACE ACROSS MOST OF THE CWA ON THU/FRI UNTIL THE SURFACE HIGH HAS SHIFTED FAR ENOUGH EAST FOR WINDS TO TURN SLY AROUND ITS BACK SIDE. RETURN FLOW SETS UP FARTHER WEST ACROSS THE PLAINS ON THU NIGHT/FRI AHEAD OF THE NEXT LOW PRESSURE SYSTEM WHICH WILL BE CROSSING FROM THE PACIFIC NW INTO THE PLAINS OVER THE WEEKEND. THIS SYSTEM WILL BRING THE NEXT CHANCE FOR SH/TS TO THE LSX CWA OVER THE WEEKEND. ANOTHER STOUT COLD FRONT IS EXPECTED TO MOVE ACROSS THE CWA ON SUN AND THEN SETTLE SOUTH OF THE CWA EARLY NEXT WEEK. TEMPERATURES WILL DIP BELOW AVERAGE AGAIN IN THE WAKE OF THIS FRONT. KANOFSKY && .AVIATION: (FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 634 AM CDT WED AUG 19 2015 RAIN SHOWERS ACROSS SOUTHWEST MISSOURI WILL SPREAD NORTHEAST DURING THE MORNING IMPACTING KCOU AND THE ST. LOUIS AREA TERMINALS, WITH SHOWERS BECOMING MORE SPOTTY IN THE AFTERNOON. FUTHER NORTH WE SHOULD SEE SCATTERED SHOWERS DEVELOP IN RESPONSE TO HEATING AND THUS THE COVERAGE AND DIRECT IMPACT AT KUIN IS LESS CERTAIN HENCE ONLY MENTIONED VCSH. FLIGHT CONDITIONS SHOULD BE IN THE HIGH-END MVFR TO LOW-END VFR RANGE MUCH OF THE DAY WITH CLEARING SKIES AREAWIDE BY EARLY THIS EVENING. SPECIFICS FOR KSTL: RAIN SHOWERS WILL SPREAD FROM SOUTHWEST MISSOURI INTO KSTL BY MID-MORNING. SHOWERS SHOULD PERSIST THROUGH EARLY AFTERNOON AND THEN BECOME MORE SPOTTY BY LATE AFTERNOON. EXPECT FLIGHT CONDITIONS IN THE HIGH-END MVFR TO LOW-END VFR RANGE MUCH OF THE DAY WITH CLEARING SKIES EARLY THIS EVENING. GLASS && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
407 AM CDT WED AUG 19 2015 .SHORT TERM: (THROUGH TONIGHT) ISSUED AT 306 AM CDT WED AUG 19 2015 A STOUT COLD FRONT WAS SWEEPING THROUGH THE REGION EARLY THIS MORNING. AT 08Z, THE FRONT STRETCHED FROM ITS PARENT CYCLONE OVER SRN MN SEWD THROUGH ERN IA, THEN CURVED BACK SWWD THROUGH MO AND INTO SERN KS AND NRN OK. WATER VAPOR IMAGERY AND RAP PV ANALYSES DEPICT A SECONDARY VORT MAX DIVING INTO THE BASE OF THE TROUGH, WHICH IS CONSISTENT WITH MODEL GUIDANCE. LARGE SCALE ASCENT AHEAD OF THIS FEATURE WILL SUPPORT PERIODS OF SH/TS TODAY INTO TONIGHT. PRECIPITATION SHOULD TAPER OFF TONIGHT IN THE WAKE OF THE AFOREMENTIONED VORT MAX. WED NIGHT/EARLY THU MORNING LOWS IN THE 50S WILL BE AROUND 10 DEGREES BELOW AVERAGE. KANOFSKY .LONG TERM: (THURSDAY THROUGH TUESDAY) ISSUED AT 306 AM CDT WED AUG 19 2015 SURFACE HIGH PRESSURE BUILDS INTO THE SOUTHERN PLAINS ON THU AND GRADUALLY SHIFTS EWD WITH TIME. THIS WILL KEEP COOLER/DRIER CONDITIONS AND WESTERLY WINDS IN PLACE ACROSS MOST OF THE CWA ON THU/FRI UNTIL THE SURFACE HIGH HAS SHIFTED FAR ENOUGH EAST FOR WINDS TO TURN SLY AROUND ITS BACK SIDE. RETURN FLOW SETS UP FARTHER WEST ACROSS THE PLAINS ON THU NIGHT/FRI AHEAD OF THE NEXT LOW PRESSURE SYSTEM WHICH WILL BE CROSSING FROM THE PACIFIC NW INTO THE PLAINS OVER THE WEEKEND. THIS SYSTEM WILL BRING THE NEXT CHANCE FOR SH/TS TO THE LSX CWA OVER THE WEEKEND. ANOTHER STOUT COLD FRONT IS EXPECTED TO MOVE ACROSS THE CWA ON SUN AND THEN SETTLE SOUTH OF THE CWA EARLY NEXT WEEK. TEMPERATURES WILL DIP BELOW AVERAGE AGAIN IN THE WAKE OF THIS FRONT. KANOFSKY && .AVIATION: (FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1159 PM CDT TUE AUG 18 2015 COMPLEX OF THUNDERSTORMS OVER CENTRAL MISSOURI WILL MOVE INTO THE ST. LOUIS METRO TAF SITES AROUND 06Z PRODUCING MVFR AND POSSIBLY BRIEF IFR VISIBILITIES AS WELL AS GUSTY WINDS THROUGH 08Z BEFORE THE THUNDERSTORMS MOVE OFF TO THE EAST. COLD FRONT WILL MOVE THROUGH KUIN AND KCOU AROUND 09Z AND THE ST. LOUIS METRO TAF SITES AROUND 12Z. CEILINGS WILL BE HIGH MVFR OR LOW VFR WITH THE PASSAGE OF THE COLD FRONT INTO THE MORNING HOURS. EXPECT RAIN TO DEVELOP DURING THE MORNING HOURS AT KCOU AND AT THE ST. LOUIS METRO TAF SITES WITH SCATTERED SHOWERS AROUND QUINCY. RAIN SHOULD END BY LATE IN THE DAY. SPECIFICS FOR KSTL: EXPECT THUNDERSTORMS WITH VISIBILITIES AS LOW AS IFR TO AFFECT THE TERMINAL THROUGH 08Z. CEILINGS WILL BE LOW MVFR OR HIGH VFR WITH THE PASSAGE OF A COLD FRONT AROUND 12Z. THEN RAIN WILL MOVE INTO THE AREA BY MID MORNING AND LAST MOST OF THE DAY BEFORE ENDING BY 00Z. BRITT && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1200 AM CDT WED AUG 19 2015 .SHORT TERM: (THROUGH LATE TONIGHT) ISSUED AT 355 PM CDT TUE AUG 18 2015 PREFRONTAL CONVECTION HAS BLOWN UP ABOUT AS EXPECTED THIS AFTERNOON. SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 900 PM THIS EVENING AND WE`VE HAD SOME SPORADIC REPORTS OF TREE LIMBS DOWN WITH THE STRONGEST STORMS. SBCAPE IN EXCESS OF 3000 J/KG INDICATED ON SPC MESOANALYSIS PAGE AHEAD OF THE CONVECTION WITH A VIGOROUS SHORTWAVE MOVING INTO WESTERN MISSOURI AT THIS TIME. MASS FIELDS ON SHORT- RANGE GUIDANCE CONTINUE TO STREAM INSTABILITY UP INTO THE REGION THROUGH THE EVENING...AND THIS LOOKS REASONABLE GIVEN THE POSITION OF THE SHORTWAVE AND SURFACE FRONT. HAVE TO SAY, THE HRRR DID A PRETTY GOOD JOB WITH THE CONVECTION THIS AFTERNOON, SO THE SHORT RANGE FORECAST FOR TONIGHT IS BIASED HEAVILY TOWARD THE HRRR. EXPECT STORMS CURRENTLY OVER EASTERN KANSAS TO CONTINUE TO DEVELOP AND MOVE EASTWARD TONIGHT AHEAD OF THE SHORTWAVE. THERE WILL LIKELY BE A LUL IN THE THUNDERSTORM ACTIVITY OVER OUR CWFA AFTER 00-02Z, BUT THE STORMS CURRENTLY IN KANSAS WILL EVENTUALLY MOVE IN AFTER 04- 05Z. ADDITIONAL DEVELOPMENT IS ALSO POSSIBLE AHEAD OF THE KANSAS STORMS. THE COLD FRONT WILL SWEEP INTO MISSOURI OVERNIGHT AND SHOULD BE THROUGH CENTRAL AND INTO EASTERN MISSOURI BY 12Z. CARNEY .LONG TERM: (WEDNESDAY THROUGH NEXT TUESDAY) ISSUED AT 355 PM CDT TUE AUG 18 2015 MODELS CONTINUE TO SUPPORT A FAST SURFACE FRONTAL SOLUTION WHILE MAINTAINING A SIMILAR TIMING WITH THE UPPER LEVEL PROFILE. WHILE THERE SHOULD STILL BE A NICE SLUG OF WIDESPREAD LIFT BUILDING IN FROM LATE WEDNESDAY MORNING THRU EARLY EVENING...THE COLUMN WILL BE VERY LIMITED THERMODYNAMICALLY...MEANING LIKE MOSTLY SHOWERS WITH DIMINISHING CHANCES FOR THUNDER AS THE DAY GOES ALONG. DECENT RAIN CHANCES ARE NOW EXPECTED TO LINGER INTO EARLY EVENING BEFORE THEN MAKING A RAPID EXIT FROM SOUTHWEST TO NORTHEAST FOLLOWED QUICKLY BY CLEARING SKIES. WHAT WILL REMAIN IN ITS WAKE WILL BE A RARE COOL AND DRY PERIOD BEGINNING LATE WEDNESDAY NIGHT THRU FRIDAY AFTERNOON WITH MIN TEMPS DIPPING INTO THE 50S AND MAX TEMPS ONLY REACHING TO AROUND 80 DEGREES. THE FRONTAL COMPLEX THAT HAD PUSHED TO OUR SOUTH ON WEDNESDAY WILL THEN MOVE BACK TO THE NORTH BY SATURDAY TO ALLOW CHANCES FOR THUNDERSTORMS TO RETURN AND PERSIST THRU THE WEEKEND WITH TEMPERATURES BACK TO SEASONABLE AVERAGES. IN YET ANOTHER SIGN THAT AUTUMN IS NOT TOO FAR OFF ANYMORE...ANOTHER DECENTLY STRONG COLD FRONT PUSHES THRU LATE SUNDAY AND IS EXPECTED TO BRING AN ENCORE OF THE COOL AND DRY PERIOD FOR MONDAY AND TUESDAY OF NEXT WEEK. SOME MODEL DISCREPANCIES THEN EXIST HEADING DEEPER INTO NEXT WEEK BUT THE GENERAL THEME IS SUMMER THEN REMINDING US THAT IT IS NOT YET DONE...WITH AN UPPER LEVEL RIDGE ATTEMPTING TO BUILD IN TO POSSIBLY DELIVER ONE FINAL ROUND OF DANGEROUS HEAT AND HUMIDITY TO CLOSE OUT AUGUST. TES && .AVIATION: (FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1159 PM CDT TUE AUG 18 2015 COMPLEX OF THUNDERSTORMS OVER CENTRAL MISSOURI WILL MOVE INTO THE ST. LOUIS METRO TAF SITES AROUND 06Z PRODUCING MVFR AND POSSIBLY BRIEF IFR VISIBILITIES AS WELL AS GUSTY WINDS THROUGH 08Z BEFORE THE THUNDERSTORMS MOVE OFF TO THE EAST. COLD FRONT WILL MOVE THROUGH KUIN AND KCOU AROUND 09Z AND THE ST. LOUIS METRO TAF SITES AROUND 12Z. CEILINGS WILL BE HIGH MVFR OR LOW VFR WITH THE PASSAGE OF THE COLD FRONT INTO THE MORNING HOURS. EXPECT RAIN TO DEVELOP DURING THE MORNING HOURS AT KCOU AND AT THE ST. LOUIS METRO TAF SITES WITH SCATTERED SHOWERS AROUND QUINCY. RAIN SHOULD END BY LATE IN THE DAY. SPECIFICS FOR KSTL: EXPECT THUNDERSTORMS WITH VISIBILITIES AS LOW AS IFR TO AFFECT THE TERMINAL THROUGH 08Z. CEILINGS WILL BE LOW MVFR OR HIGH VFR WITH THE PASSAGE OF A COLD FRONT AROUND 12Z. THEN RAIN WILL MOVE INTO THE AREA BY MID MORNING AND LAST MOST OF THE DAY BEFORE ENDING BY 00Z. BRITT && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
251 PM EDT WED AUG 19 2015 .SYNOPSIS... UNSETTLED WEATHER WILL CONTINUE THROUGH THURSDAY. A WEAK COLD FRONT WILL MOVE ACROSS THE AREA FRIDAY. LESS COVERAGE OF SHOWERS AND THUNDERSTORMS CAN BE EXPECTED FRIDAY THROUGH EARLY NEXT WEEK WITH TYPICAL LATE SUMMERTIME TEMPERATURES. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... AS OF 300 PM WEDNESDAY...SCATTERED CONVECTION CONTINUES ACROSS MUCH OF THE FORECAST AREA AND WILL CONTINUE THROUGH THE EVENING. WITH LARGE SCALE FORCING MAINLY ABSENT THE BEST FOCUS FOR CONVECTION IS ALONG THE OUTFLOW BOUNDARIES. SEVERAL AREAS ARE SEEING VERY HEAVY RAIN WITH 1 TO 2 INCHES AN HOUR. THIS IS BEING HELPED BY A VERY MOIST ATMOSPHERE WITH PRECIPITABLE WATER VALUES BETWEEN 2 AND 2.25 INCHES. THE 17 UTC RUN OF THE HRRR IS ECHOING THE 13 AND 16 UTC RUNS OF THE HRRR WITH THE DIURNAL CONVECTION CONTINUING OVER MUCH OF THE FORECAST AREA THROUGH 22 UTC THEN SLOWLY DISSIPATING BY SUNSET. MAXIMUM TEMPERATURES ARE RUNNING IN THE MID TO UPPER 80S AND ARE PEAKING FOR THE DAY. OVERNIGHT TEMPERATURES ARE EXPECTED TO DROP INTO THE MIDDLE 70S INLAND AND THE UPPER 70S AT THE COAST. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... AS OF 300 PM WEDNESDAY...A MID LEVEL CYCLONE WILL MOVE ACROSS THE GREAT LAKES WITH A BROAD ZONAL FLOW PUSHING A COLD FRONT ACROSS THE AREA EARLY FRIDAY. BY THE END OF THE PERIOD MID LEVEL HIGH PRESSURE BUILDS BACK IN FROM THE SOUTH WITH ANY APPRECIABLE AFFECTS FROM THE FRONT BASICALLY GONE. FOR THURSDAY...WEAK SURFACE TROUGHING WILL STILL RESIDE ACROSS THE AREA AND GOOD CHANCE POPS REMAIN IN THE FORECAST. POPS DECREASE SOMEWHAT FOR FRIDAY AS THE WEAK FRONT HAS A SIGNIFICANT SUBSIDENCE INVERSION IN THE 700-850MB LAYER WHICH WILL MAKE CONVECTIVE DEVELOPMENT MORE CHALLENGING THAN PREVIOUS DAYS. THERE REMAINS A VERY MOIST PROFILE HOWEVER AND LOWER CHANCE POPS SHOULD BE A GOOD COMPROMISE. TEMPERATURES CHANGE LITTLE THROUGH THE PERIOD WITH HIGHS IN THE 90S AND LOWS IN THE 70S. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 300 AM WEDNESDAY...COLD FRONT PUSHING OFFSHORE FIRST THING SATURDAY WILL LEAVE CLEARING SKY CONDITIONS AND IMPROVING WEATHER FOR THE WKND. WHILE THIS FASTER FROPA REPRESENTS A CHANGE IN THE FORECAST...GUIDANCE IS IN GOOD AGREEMENT ATTM WITH A STRONG MID- LEVEL PUSH...AND THE WKND IS LOOKING TO BE QUITE NICE LOCALLY NOW. WEAK COOL ADVECTION BUT STRONG DRY ADVECTION WILL ERODE CLOUDS SATURDAY...AND THEN LEAVE AMPLE SUNSHINE LATE SATURDAY AND ON SUNDAY...AS PWATS DROP TO AROUND THE FIRST QUARTILE MOVING-AVERAGE FOR LATE AUGUST. TEMPS THIS WKND WILL BE AROUND OR SLIGHTLY BELOW CLIMO WITH N/NE WINDS...BUT OVERALL A PLEASANT WKND APPEARS TO BE IN STORE. RETURN FLOW BEGINS TO REDEVELOP MONDAY WITH TEMPS WARMING BACK TO SEASONABLE LEVELS OR SLIGHTLY ABOVE...BUT THIS WILL BE ACCOMPANIED BY INCREASING PRECIP CHANCES AS WELL. GFS DRIVES A POTENT SHORTWAVE OVERHEAD LATE MONDAY INTO TUESDAY...A PIECE OF THE LONGER TROUGH TRAVERSING THE NORTHEAST...WHILE THE ECMWF SHOWS NO SUCH FEATURE. FOR NOW WILL RAMP POP BACK UP TO CLIMO VALUES FOR EARLY NEXT WEEK...MAINTAINING THE INHERITED FORECAST && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... AS OF 18Z...EXPECT VFR FOR THE REST OF THE VALID TAF PERIOD WITH ISOLATED TO SCATTERED SHRA/TSRA THIS AFTERNOON AND TONIGHT. POTENTIAL FOR PATCHY MARGINAL MVFR FOG OVERNIGHT. LATEST RADAR DEPICTS ISOLATED TO SCATTERED SHRA/TSRA DEVELOPING ACROSS THE AREA. WHILE COULD SEE BRIEF PERIODS OF MVFR IN ANY HEAVY DOWNPOURS...OVERALL EXPECT VFR THROUGH TONIGHT. SOUTHWEST WINDS WILL INCREASE TO AOB 12 KTS THIS AFTERNOON...BECOMING LIGHT AND VARIABLE TONIGHT. COULD SEE PATCHY AREAS OF MARGINAL MVFR FOG LATE OVERNIGHT...THUS HAVE INTRODUCED TEMPO GROUP. AFTER DAYBREAK...VFR WILL PREVAIL WITH SOUTHWEST WINDS. EXTENDED OUTLOOK...SCATTERED CONVECTION IS EXPECTED THROUGH THE PERIOD...MOST ACTIVE THURSDAY WITH BRIEF IFR CONDITIONS POSSIBLE. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM WEDNESDAY...SOUTH TO SOUTHWEST WINDS OF 10 TO 15 KNOTS ARE BLOWING OVER THE WATERS WITH SEAS CONTINUING TO RUN BETWEEN 2 AND 3 FEET. THE FRYING PAN BUOY CONTINUES TO SHOWS A ESE SWELL OF 1.3 FEET WITH THE 2.3 FT WIND WAVE AND THESE CONDITIONS ARE EXPECTED TO REMAIN THE SAME THROUGHOUT THE OVERNIGHT WITH THE ONLY HAZARD WILL BE AN ISOLATED SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 PM WEDNESDAY...THE PIEDMONT TROUGH WILL BECOME MORE A LITTLE BETTER DEFINED THURSDAY AND WIND FIELDS WILL SHOULD RESPOND WITH A SOUTHWEST FLOW OF 10-15 KNOTS...MOSTLY IN THE LOWER END OF THE RANGE. A WEAK FRONT WILL PUSH ACROSS THE WATERS EARLY FRIDAY WITH THE FRONT AND THE LAND BREEZE PROVIDING A BRIEF OFFSHORE FLOW. BY LATER IN THE DAY LIGHT AND VARIABLE WINDS DEVELOP UNDER A WEAK PRESSURE PATTERN. AS FOR SEAS...GENERALLY 2-3 FEET THROUGH THE PERIOD. LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 300 AM WEDNESDAY...COLD FRONT WILL BE SOUTH OF THE WATERS SATURDAY MORNING...LEAVING NE WINDS IN ITS WAKE. THIS WIND DIRECTION WILL PERSIST MUCH OF THE PERIOD...BUT A WEAKENING OF THE FRONT WILL ALLOW RETURN FLOW AND SOUTHERLY WINDS TO REDEVELOP LATE. SPEEDS FROM THE NE WILL BE 10-15 KTS...EASING AS THE WINDS SHIFT AT THE END OF THE PERIOD. WAVE HEIGHTS WILL BE PRIMARILY WIND-WAVE DRIVEN...BUT OF LOW AMPLITUDE AROUND 1-3 FT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...SHK NEAR TERM...DRH SHORT TERM...SHK LONG TERM...JDW AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
152 PM EDT WED AUG 19 2015 .SYNOPSIS... UNSETTLED WEATHER WILL CONTINUE THROUGH MID WEEK AS TROPICAL MOISTURE STREAMS INTO THE AREA AHEAD OF AN APPROACHING COLD FRONT. THE FRONT WILL REACH THE COASTAL CAROLINAS BY FRIDAY AND OFFSHORE OVER THE WEEKEND. ANOTHER COLD FRONT MAY APPROACH ON TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1230 PM WEDNESDAY...SCATTERED CONVECTION HAS DEVELOPED ACROSS MUCH OF THE THE AREA AND IS EXPECTED TO CONTINUE TO DEVELOP ALONG OUTFLOWS AS LARGE SCALE FORCING IS NOT A MAJOR INFLUENCE TODAY. WITH THE PRECIPITABLE WATERS RUNNING OVER 2 INCHES HEAVY DOWNPOURS CAN BE EXPECTED AND FREQUENT LIGHTNING. THE 16 UTC RUN OF THE HRRR IS ECHOING THE 13 UTC RUN WITH THE DIURNAL CONVECTION CONTINUING OVER MUCH OF THE FORECAST AREA THROUGH 22 UTC THEN DISSIPATING. MAXIMUM TEMPERATURES ARE RUNNING IN THE MID TO UPPER 80S AND ARE PEAKING FOR THE DAY. OVERNIGHT TEMPERATURES ARE EXPECTED TO DROP INTO THE MIDDLE 70S INLAND AND THE UPPER 70S AT THE COAST. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 AM WEDNESDAY...BIGGEST QUESTION MARK FOR THE SHORT TERM WILL BE HOW FAR SOUTH DOES A COLD FRONT PROGRESS ACROSS THE CAROLINAS. AHEAD OF THIS FEATURE...SHARP RIDGING ALOFT COMBINED WITH RETURN FLOW WILL PUMP HEAT AND HUMIDITY INTO THE REGION...AND HIGHS WILL RISE INTO THE 90S EVERYWHERE AWAY FROM THE IMMEDIATE COAST. THIS IS SEVERAL DEGREES ABOVE NORMAL FOR MID-AUGUST...AND THE HIGH DEWPOINTS WILL MAKE HEAT INDEX VALUES RISE TO 100 OR SLIGHTLY GREATER. AMPLE INSTABILITY WITHIN THIS AIRMASS WILL BE TAPPED BY A SHORTWAVE PROGGED TO MOVE OVERHEAD IN THE AFTN...AND SCATTERED TO POTENTIALLY WIDESPREAD CONVECTION IS POSSIBLE. MOS P-NUMBERS HAVE INCREASED TO LIKELY ACROSS THE AREA...BUT THEY HAVE BEEN OVERDONE RECENTLY. WILL BUMP POP TO HIGH-CHC LOCALLY WITH PERIODS OF HEAVY RAINFALL THE BIGGEST THREAT. LOWS THURSDAY NIGHT WILL BE QUITE WARM...FALLING INTO THE MID 70S...WITH SOME UPPER 70S POSSIBLE ALONG THE COAST. FRIDAY WILL BE THE TRANSITION DAY AS THE COLD FRONT TO THE WEST MOVES ACROSS THE AREA. ALL GUIDANCE HAS INCREASED THE SPEED OF THIS FEATURE...LIKELY DUE TO A STRONGER PARENT TROUGH AND VORT LOBE..WITH LESS MID-LEVEL PARALLEL FLOW. WPC SUPPORTS THIS FASTER GUIDANCE AS WELL...SO WILL SHOW THE FRONT MOVING OFFSHORE BY LATE FRIDAY. CONVECTION WILL ACCOMPANY THIS BOUNDARY AS IT SWINGS S/SE FRIDAY INTO FRIDAY NIGHT...BUT DRYING DOES OCCUR IN EARNEST LATE SO BEST PRECIP CHANCES WILL BE THE FIRST HALF OF FRIDAY. TEMPS WILL REMAIN ABOVE NORMAL THANKS TO WARM ADVECTION AHEAD OF THE BOUNDARY...BUT WILL BE A FEW DEGREES COOLER THAN THURSDAY. LOWS FRIDAY NIGHT WILL REMAIN ABOVE CLIMO AS WEAK COLD ADVECTION LAGS...WITH MINS DROPPING INTO THE 72-75 DEGREE RANGE...WARMEST AT THE COAST. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 300 AM WEDNESDAY...COLD FRONT PUSHING OFFSHORE FIRST THING SATURDAY WILL LEAVE CLEARING SKY CONDITIONS AND IMPROVING WEATHER FOR THE WKND. WHILE THIS FASTER FROPA REPRESENTS A CHANGE IN THE FORECAST...GUIDANCE IS IN GOOD AGREEMENT ATTM WITH A STRONG MID- LEVEL PUSH...AND THE WKND IS LOOKING TO BE QUITE NICE LOCALLY NOW. WEAK COOL ADVECTION BUT STRONG DRY ADVECTION WILL ERODE CLOUDS SATURDAY...AND THEN LEAVE AMPLE SUNSHINE LATE SATURDAY AND ON SUNDAY...AS PWATS DROP TO AROUND THE FIRST QUARTILE MOVING-AVERAGE FOR LATE AUGUST. TEMPS THIS WKND WILL BE AROUND OR SLIGHTLY BELOW CLIMO WITH N/NE WINDS...BUT OVERALL A PLEASANT WKND APPEARS TO BE IN STORE. RETURN FLOW BEGINS TO REDEVELOP MONDAY WITH TEMPS WARMING BACK TO SEASONABLE LEVELS OR SLIGHTLY ABOVE...BUT THIS WILL BE ACCOMPANIED BY INCREASING PRECIP CHANCES AS WELL. GFS DRIVES A POTENT SHORTWAVE OVERHEAD LATE MONDAY INTO TUESDAY...A PIECE OF THE LONGER TROUGH TRAVERSING THE NORTHEAST...WHILE THE ECMWF SHOWS NO SUCH FEATURE. FOR NOW WILL RAMP POP BACK UP TO CLIMO VALUES FOR EARLY NEXT WEEK...MAINTAINING THE INHERITED FORECAST && .AVIATION /18Z WEDNESDAY THROUGH TUESDAY/... AS OF 18Z...EXPECT VFR FOR THE REST OF THE VALID TAF PERIOD WITH ISOLATED TO SCATTERED SHRA/TSRA THIS AFTERNOON AND TONIGHT. POTENTIAL FOR PATCHY MARGINAL MVFR FOG OVERNIGHT. LATEST RADAR DEPICTS ISOLATED TO SCATTERED SHRA/TSRA DEVELOPING ACROSS THE AREA. WHILE COULD SEE BRIEF PERIODS OF MVFR IN ANY HEAVY DOWNPOURS...OVERALL EXPECT VFR THROUGH TONIGHT. SOUTHWEST WINDS WILL INCREASE TO AOB 12 KTS THIS AFTERNOON...BECOMING LIGHT AND VARIABLE TONIGHT. COULD SEE PATCHY AREAS OF MARGINAL MVFR FOG LATE OVERNIGHT...THUS HAVE INTRODUCED TEMPO GROUP. AFTER DAYBREAK...VFR WILL PREVAIL WITH SOUTHWEST WINDS. EXTENDED OUTLOOK...SCATTERED CONVECTION IS EXPECTED THROUGH THE PERIOD...MOST ACTIVE THURSDAY WITH BRIEF IFR CONDITIONS POSSIBLE. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1230 PM WEDNESDAY...LIGHT SOUTHWEST WINDS OVER THE WATERS THIS MORNING WITH SEAS RUNNING 2 TO 3 FEET WITH A 1.3 EAST SOUTHEAST SWELL. SCATTERED THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AS A FEW STORMS THAT DEVELOP ALONG THE COAST COULD MOVE OUT OVER THE WATER. THE MAIN THREAT APPEARS TO BE LIGHTNING. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 AM WEDNESDAY...PRE- FRONTAL REGIME THURSDAY WILL LEAVE SW WINDS OF 10-15 KTS ACROSS THE WATERS. THIS WILL BE SHORT-LIVED HOWEVER AS A COLD FRONT RACES TOWARDS THE WATERS DURING FRIDAY. THIS FRONT WILL CROSS INTO THE WATERS AND THEN DROP SOUTH BY FRIDAY NIGHT...LEAVING WINDS SHIFTING FROM WEST...ALL THE WAY AROUND TO THE EAST...AND THEN FINALLY TAKING ON A PREDOMINANT NE DIRECTION LATE IN THE PERIOD. SPEEDS THROUGH FRIDAY WILL BE LIGHT REGARDLESS OF DIRECTION...LESS THAN 10 KTS. SEAS THURSDAY WILL BE 2-3 FT WITH A SE SWELL AND SW WIND CHOP COMPRISING THE SPECTRUM. WAVE HEIGHTS FRIDAY WILL DROP TO JUST 1-2 FT ON THE LIGHTER WINDS...WITH A VARIETY OF WAVE GROUPS PRESENT. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 300 AM WEDNESDAY...COLD FRONT WILL BE SOUTH OF THE WATERS SATURDAY MORNING...LEAVING NE WINDS IN ITS WAKE. THIS WIND DIRECTION WILL PERSIST MUCH OF THE PERIOD...BUT A WEAKENING OF THE FRONT WILL ALLOW RETURN FLOW AND SOUTHERLY WINDS TO REDEVELOP LATE. SPEEDS FROM THE NE WILL BE 10-15 KTS...EASING AS THE WINDS SHIFT AT THE END OF THE PERIOD. WAVE HEIGHTS WILL BE PRIMARILY WIND-WAVE DRIVEN...BUT OF LOW AMPLITUDE AROUND 1-3 FT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...DRH SHORT TERM...JDW LONG TERM...JDW AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1042 AM EDT WED AUG 19 2015 .SYNOPSIS... UNSETTLED WEATHER WILL CONTINUE THROUGH MID WEEK AS TROPICAL MOISTURE STREAMS INTO THE AREA AHEAD OF AN APPROACHING COLD FRONT. THE FRONT WILL REACH THE COASTAL CAROLINAS BY FRIDAY AND OFFSHORE OVER THE WEEKEND. ANOTHER COLD FRONT MAY APPROACH ON TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM WEDNESDAY...THE AREA HAS CLEAR OUT OF CONVECTION AND CLOUDS AFTER A SHORT WAVE PROGRESSES ACROSS THE FORECAST AREA THIS MORNING. THE HRRR IS SHOWING VERY WEAK FORCING THE REMAINDER IN THE SOUTHWEST FLOW ALOFT. INSTABILITIES ARE MODERATE FOR THIS AFTERNOON AND THE PRIMARY THREAT APPEARS TO BE LOCALLY HEAVY DOWNPOURS. THE 13 UTC RUN OF THE HRRR IS SHOWING DIURNAL CONVECTION DEVELOPING ALONG THE SEA BREEZE FIRST JUST AFTER 16 UTC AND THEN BECOMING SCATTERED INLAND AND SLOWLY DISSIPATING AFTER SUNSET. TEMPERATURES ARE RUNNING A LITTLE WARMER AS LACK OF CLOUD COVER IS ALLOWING THE TEMPERATURES TO INCREASE QUICKER BUT EXPECTED THE CLOUD COVER TO INCREASE QUICKLY THIS AFTERNOON WHEN THE CONVECTIVE TEMPERATURE IS MET. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 AM WEDNESDAY...BIGGEST QUESTION MARK FOR THE SHORT TERM WILL BE HOW FAR SOUTH DOES A COLD FRONT PROGRESS ACROSS THE CAROLINAS. AHEAD OF THIS FEATURE...SHARP RIDGING ALOFT COMBINED WITH RETURN FLOW WILL PUMP HEAT AND HUMIDITY INTO THE REGION...AND HIGHS WILL RISE INTO THE 90S EVERYWHERE AWAY FROM THE IMMEDIATE COAST. THIS IS SEVERAL DEGREES ABOVE NORMAL FOR MID-AUGUST...AND THE HIGH DEWPOINTS WILL MAKE HEAT INDEX VALUES RISE TO 100 OR SLIGHTLY GREATER. AMPLE INSTABILITY WITHIN THIS AIRMASS WILL BE TAPPED BY A SHORTWAVE PROGGED TO MOVE OVERHEAD IN THE AFTN...AND SCATTERED TO POTENTIALLY WIDESPREAD CONVECTION IS POSSIBLE. MOS P-NUMBERS HAVE INCREASED TO LIKELY ACROSS THE AREA...BUT THEY HAVE BEEN OVERDONE RECENTLY. WILL BUMP POP TO HIGH-CHC LOCALLY WITH PERIODS OF HEAVY RAINFALL THE BIGGEST THREAT. LOWS THURSDAY NIGHT WILL BE QUITE WARM...FALLING INTO THE MID 70S...WITH SOME UPPER 70S POSSIBLE ALONG THE COAST. FRIDAY WILL BE THE TRANSITION DAY AS THE COLD FRONT TO THE WEST MOVES ACROSS THE AREA. ALL GUIDANCE HAS INCREASED THE SPEED OF THIS FEATURE...LIKELY DUE TO A STRONGER PARENT TROUGH AND VORT LOBE..WITH LESS MID-LEVEL PARALLEL FLOW. WPC SUPPORTS THIS FASTER GUIDANCE AS WELL...SO WILL SHOW THE FRONT MOVING OFFSHORE BY LATE FRIDAY. CONVECTION WILL ACCOMPANY THIS BOUNDARY AS IT SWINGS S/SE FRIDAY INTO FRIDAY NIGHT...BUT DRYING DOES OCCUR IN EARNEST LATE SO BEST PRECIP CHANCES WILL BE THE FIRST HALF OF FRIDAY. TEMPS WILL REMAIN ABOVE NORMAL THANKS TO WARM ADVECTION AHEAD OF THE BOUNDARY...BUT WILL BE A FEW DEGREES COOLER THAN THURSDAY. LOWS FRIDAY NIGHT WILL REMAIN ABOVE CLIMO AS WEAK COLD ADVECTION LAGS...WITH MINS DROPPING INTO THE 72-75 DEGREE RANGE...WARMEST AT THE COAST. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 300 AM WEDNESDAY...COLD FRONT PUSHING OFFSHORE FIRST THING SATURDAY WILL LEAVE CLEARING SKY CONDITIONS AND IMPROVING WEATHER FOR THE WKND. WHILE THIS FASTER FROPA REPRESENTS A CHANGE IN THE FORECAST...GUIDANCE IS IN GOOD AGREEMENT ATTM WITH A STRONG MID- LEVEL PUSH...AND THE WKND IS LOOKING TO BE QUITE NICE LOCALLY NOW. WEAK COOL ADVECTION BUT STRONG DRY ADVECTION WILL ERODE CLOUDS SATURDAY...AND THEN LEAVE AMPLE SUNSHINE LATE SATURDAY AND ON SUNDAY...AS PWATS DROP TO AROUND THE FIRST QUARTILE MOVING-AVERAGE FOR LATE AUGUST. TEMPS THIS WKND WILL BE AROUND OR SLIGHTLY BELOW CLIMO WITH N/NE WINDS...BUT OVERALL A PLEASANT WKND APPEARS TO BE IN STORE. RETURN FLOW BEGINS TO REDEVELOP MONDAY WITH TEMPS WARMING BACK TO SEASONABLE LEVELS OR SLIGHTLY ABOVE...BUT THIS WILL BE ACCOMPANIED BY INCREASING PRECIP CHANCES AS WELL. GFS DRIVES A POTENT SHORTWAVE OVERHEAD LATE MONDAY INTO TUESDAY...A PIECE OF THE LONGER TROUGH TRAVERSING THE NORTHEAST...WHILE THE ECMWF SHOWS NO SUCH FEATURE. FOR NOW WILL RAMP POP BACK UP TO CLIMO VALUES FOR EARLY NEXT WEEK...MAINTAINING THE INHERITED FORECAST && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... AS OF 12Z...AREAS OF MVFR DUE TO FOG THIS MORNING...GIVING WAY TO VFR FOR THE REST OF THE VALID TAF PERIOD WITH ISOLATED TO SCATTERED SHRA/TSRA POSSIBLE. LATEST RADAR IMAGERY DEPICTS A FEW LIGHT SHOWERS ACROSS THE AREA THIS MORNING...WITH OBSERVATIONS INDICATING LIGHT WINDS AND PATCHY AREAS OF FOG. COULD SEE BRIEF MARGINAL MVFR DUE TO FOG THIS MORNING...BUT CONFIDENCE IS LOW. EXPECT VFR TO PREVAIL LATER THIS MORNING WITH ISOLATED TO SCATTERED SHRA/TSRA ACTIVITY THROUGH TODAY AND SOUTHWEST WINDS INCREASING TO AOB 12 KTS. INTO THE EVENING HOURS...CONVECTION WILL TAPER OFF AND WINDS WILL BECOME LIGHT. EXTENDED OUTLOOK...SCATTERED CONVECTION IS EXPECTED THROUGH THE PERIOD...MOST ACTIVE WEDNESDAY AND THURSDAY WITH BRIEF IFR CONDITIONS POSSIBLE. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM WEDNESDAY...LIGHT SOUTHWEST WINDS OVER THE WATERS THIS MORNING WITH SEAS RUNNING 2 TO 3 FEET WITH A 1.3 EAST SOUTHEAST SWELL. SCATTERED THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AS A FEW STORMS THAT DEVELOP ALONG THE COAST COULD MOVE OUT OVER THE WATER. THE MAIN THREAT APPEARS TO BE LIGHTNING. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 AM WEDNESDAY...PRE- FRONTAL REGIME THURSDAY WILL LEAVE SW WINDS OF 10-15 KTS ACROSS THE WATERS. THIS WILL BE SHORT-LIVED HOWEVER AS A COLD FRONT RACES TOWARDS THE WATERS DURING FRIDAY. THIS FRONT WILL CROSS INTO THE WATERS AND THEN DROP SOUTH BY FRIDAY NIGHT...LEAVING WINDS SHIFTING FROM WEST...ALL THE WAY AROUND TO THE EAST...AND THEN FINALLY TAKING ON A PREDOMINANT NE DIRECTION LATE IN THE PERIOD. SPEEDS THROUGH FRIDAY WILL BE LIGHT REGARDLESS OF DIRECTION...LESS THAN 10 KTS. SEAS THURSDAY WILL BE 2-3 FT WITH A SE SWELL AND SW WIND CHOP COMPRISING THE SPECTRUM. WAVE HEIGHTS FRIDAY WILL DROP TO JUST 1-2 FT ON THE LIGHTER WINDS...WITH A VARIETY OF WAVE GROUPS PRESENT. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 300 AM WEDNESDAY...COLD FRONT WILL BE SOUTH OF THE WATERS SATURDAY MORNING...LEAVING NE WINDS IN ITS WAKE. THIS WIND DIRECTION WILL PERSIST MUCH OF THE PERIOD...BUT A WEAKENING OF THE FRONT WILL ALLOW RETURN FLOW AND SOUTHERLY WINDS TO REDEVELOP LATE. SPEEDS FROM THE NE WILL BE 10-15 KTS...EASING AS THE WINDS SHIFT AT THE END OF THE PERIOD. WAVE HEIGHTS WILL BE PRIMARILY WIND-WAVE DRIVEN...BUT OF LOW AMPLITUDE AROUND 1-3 FT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...HAWKINS SHORT TERM...JDW LONG TERM...JDW AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
120 AM EDT WED AUG 19 2015 .SYNOPSIS... UNSETTLED WEATHER WILL CONTINUE THROUGH MID WEEK AS TROPICAL MOISTURE STREAMS INTO THE AREA AHEAD OF AN APPROACHING COLD FRONT. THE FRONT WILL REACH THE COASTAL CAROLINAS BY FRIDAY AND OFFSHORE OVER THE WEEKEND. ANOTHER COLD FRONT IS EXPECTED TO REACH THE AREA TUESDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 120 AM WEDNESDAY...ONE AREA OF SHOWERS WAS BRUSHING MARLBORO AND ROBESON COUNTIES. OTHER SLOW MOVING SHOWERS AND THUNDERSTORMS WERE MOVING ACROSS CENTRAL PORTIONS OF THE CAROLINAS. THIS ACTIVITY WAS AHEAD OF A MID LEVEL SHORTWAVE WHICH WILL BE MOVING ACROSS THE AREA OVERNIGHT. WE DO EXPECT MAINLY ISOLATED THUNDERSTORMS AND SHOWERS TO PERSIST AS THEY MOVE INTO WESTERN PORTIONS OF THE FORECAST AREA OVERNIGHT. HOWEVER...THE HIGH RESOLUTION HRRR CONTINUES TO SHOW THIS ACTIVITY WANING WITH TIME WHILE CONVECTION EVENTUALLY BLOSSOMS ACROSS THE WATERS. THIS IS SIMILAR TO WHAT TRANSPIRED LAST NIGHT. WILL SHOW LOW POPS...SMALL CHANCE/SLIGHT CHANCE FOR THE REMAINDER OF THE NIGHT. HOWEVER... WILL TREND POPS HIGHER NEAR THE IMMEDIATE COAST AS THE FLOW SHOULD ALLOW SOME OF THE LATE NIGHT OCEAN SHOWERS AND THUNDERSTORMS TO BRUSH THE MORE IMMEDIATE COAST. STRATUS WAS BEGINNING TO EXPAND ACROSS THE EASTERN CAROLINAS LATE THIS EVE. I HAVE INCLUDED PATCHY FOG FOR A GOOD PORTION OF THE AREA. INLAND AREAS ARE FAVORED OVER THE MORE IMMEDIATE COAST DUE TO THE MORE SIGNIFICANT RAINFALL THERE TODAY. ALTHOUGH A DEVELOPING NOCTURNAL JET MAY FAVOR LOW STRATUS OVER FOG...THE 20-30 KT WINDS ABOVE THE BOUNDARY LAYER SHOULD BE RATHER SHORT- LIVED. && .SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/... AS OF 300 PM TUESDAY...MID TO UPPER LEVEL RIDGE ALIGNED UP THE SOUTHEAST COAST SANDWICHED BETWEEN UPPER LOW WELL OFF SHORE AND TROUGH EXTENDING DOWN FROM THE GREAT LAKES WELL WEST OF OUR AREA. THIS MID TO UPPER TROUGH WILL PUSH A COLD FRONT EAST INTO THE CAROLINAS BEFORE IT LIFTS OFF TO THE NORTHEAST INTO CANADA BY THURS NIGHT. PLENTY OF DEEP MOISTURE WILL STREAM INTO THE AREA AHEAD OF THIS SYSTEM AND WILL COMBINE WITH MINOR SHORTWAVE ENERGY AND LOCALIZED CONVERGENCE ALONG PIEDMONT TROUGH...SEA BREEZE AND THE COLD FRONT UPSTREAM TO PRODUCE GREATER COVERAGE OF CLOUDS AND CONVECTION THROUGH MID WEEK. LOCAL AREA WILL REMAIN ON THE TOP OF THE RIDGE WITH A FLATTER W-SW FLOW ALOFT WHICH WILL AID IN ADVECTING PLENTY OF DEBRIS CLOUDS AND STEERING CONVECTION TOWARD THE LOCAL FORECAST AREA. MOISTURE PROFILES SHOW THE BRUNT OF THIS MOISTURE IN THE MID TO UPPER LEVELS AS PLENTY OF MID TO HIGH LEVEL DEBRIS CLOUDS STREAM INTO AREA. PCP WATER VALUES REMAIN ABOVE 2 INCHES THROUGH THE PERIOD. BY LATE THURS THE COLD FRONT SHOULD DROP FAR ENOUGH SOUTH INTO THE COASTAL CAROLINAS BUT IT SHOULD BEGIN TO LAY DOWN AND SLOW DOWN OUT AS THE UPPER FLOW FLATTENS FURTHER AS MID TO UPPER TROUGH LIFTS OFF INTO CANADA. SOUTHERLY SFC WINDS WILL BEGIN TO VEER AROUND TO THE WEST BY THURS. THIS WILL PRODUCE A DEEPER DOWNSLOPE FLOW AND WILL HELP TO BREAK UP THE CLOUDS AND PRODUCE WARMER TEMPS. BUT IT WILL ALSO ENHANCE LIFT AND POTENTIAL FOR THUNDERSTORMS ACROSS THE AREA...ESPECIALLY CLOSER TO THE COAST. EXPECT TEMPS TO REACH UP INTO THE MID TO UPPER 80S ON WED AND INTO THE 90S MOST PLACES ON THURS. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 300 PM TUESDAY...A SLOW MOVING COLD FRONT LOOKS TO PUSH THROUGH ON FRIDAY. WITH MID LEVEL RIDGING AHEAD OF THIS FEATURE AND FAIRLY WEAK LOW LEVEL MOISTURE FLUX IT DOESN`T APPEAR THAT THERE WILL BE MUCH RAIN QUANTITATIVELY EVEN THOUGH FORECAST RAINFALL CHANCES MAY BE HIGHER THAN CLIMATOLOGY. THIS BOUNDARY APPEARS TO STALL CLOSE ENOUGH TO THE COAST FOR SOME SMALL RAIN CHANCES MAINLY ALONG THE BEACHES. SUNDAY AND MONDAY WILL BRING THE LOWEST RAIN CHANCES OF THE PERIOD BUT WITH A LITTLE BIT OF LINGERING LOW LEVEL MOISTURE ITS TOUGH TO GO WITH A COMPLETELY DRY FORECAST. THEY SHOULD RAMP UP AGAIN ON TUESDAY WITH THE APPROACH OF ANOTHER COLD FRONT. THIS NEXT FRONT MAY ALSO LACK MUCH IN THE WAY OF MOISTURE FLUX BUT MAY HAVE BETTER UPPER LEVEL SUPPORT FOR PRECIP GENERATION. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 06Z...PATCHES OF IFR INLAND THROUGH 13Z-15Z. ISOLATED CONVECTION MAINLY OVER THE WESTERN PORTION OF THE CWA. SOME PATCHY STRATUS IS LIKELY OVER MUCH OF THE REGION WITH WINDS AT 1K FEET AROUND 20 KTS. CONVECTIVE DEBRIS WILL KEEP CEILINGS IN THE MID CLOUD RANGE...WITH PATCHY IFR CIGS. IF WE MANAGE TO GET SOLAR INSOLATION DURING THE DAY TODAY...CONVECTION COULD BE STRONGER THAN TODAY WITH MORE COVERAGE. EXTENDED OUTLOOK...SCATTERED CONVECTION IS EXPECTED THROUGH THE PERIOD...MOST ACTIVE WEDNESDAY AND THURSDAY WITH BRIEF IFR CONDITIONS POSSIBLE. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 120 AM WEDNESDAY...SW WINDS WILL PERSIST FOR THE REMAINDER OF THE NIGHT AT UP TO AROUND 15 KT. SEAS WILL BE 2 TO 3 FT. A 9 TO 10 SECOND EASTERLY SWELL WAS BEING OBSERVED AT THE BUOYS. A WEAK TROUGH OF LOW PRESSURE ACROSS THE INLAND CAROLINAS AND BERMUDA HIGH PRESSURE WILL BETTER DEFINE THE PRESSURE GRADIENT... ESPECIALLY ON WED. WE DO EXPECT SHOWERS AND THUNDERSTORMS TO BEGIN BLOSSOMING ACROSS THE WATERS AFTER MIDNIGHT. MARINERS SHOULD EXPECT REDUCED VISIBILITY IN HEAVY RAIN WITH THIS ACTIVITY. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 300 PM TUESDAY...WEAK RETURN FLOW ON WEDNESDAY WILL VEER TO THE S-SW ON THU AS COLD FRONT REACHES INTO THE CAROLINAS. THIS WILL PRODUCE A SLIGHT TIGHTENING OF GRADIENT AND ALLOW WINDS TO INCREASE UP TO 15 KT LATE WED INTO THU. THIS SLIGHT INCREASE IN WINDS WILL PRODUCE ENOUGH SOUTHERLY PUSH TO INCREASE SEAS JUST ABOVE 3 FT. LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 300 PM TUESDAY...A COLD FRONT DROPS INTO THE AREA. THIS BOUNDARY WILL BE FAIRLY SLOW MOVING AND ALSO DECELERATING MAKING FOR A VERY GRADUAL WIND SHIFT ACROSS THE WATERS WHILE SEAS REMAIN CAPPED AT 2 FT. E TO NE WINDS ON SATURDAY EXPECTED TO STAY 10 KT OR LESS BEHIND THE BOUNDARY AND NO CHANGE IN WAVE HEIGHT EVEN IF THE FROPA SLIGHTLY STEEPENS WAVE FACES FOR A BRIEF TIME. THE BOUNDARY REMAINS JUST TO OUR SOUTH IN A DISSIPATING STATE BY SUNDAY AND IT MAY IN FACT BE TOUGH TO FIND ON SURFACE MAPS. THE HIGH THAT HAD BEEN BUILDING IN BEHIND IT WEAKENS RAPIDLY WITH THE NET LOCAL RESULT LITTLE CHANGE IN WIND OR WAVES FROM THOSE OF SATURDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...RJD/MJC SHORT TERM...RGZ LONG TERM...MBB AVIATION...DL/8
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
710 PM CDT THU AUG 20 2015 .UPDATE... ISSUED AT 706 PM CDT THU AUG 20 2015 SHORT WAVE WITH SHOWERS AND A FEW STORMS MOVING EAST THRU EAST CENTRAL SASK INTO WCNTRL MANITOBA EARLY THIS EVENING. WEAK SFC BOUNDARY DOES EXTEND FROM LOW IN NORTHEASTERN SASK TO NR YORKTON TO NEAR ESTEVAN. THIS BOUNDARY WILL MOVE EAST AND WASH OUT OVER NE ND TONIGHT. HRRR HAS BEEN TOO AGRESSIVE WITH PRECIP SO FAR INTO NW ND. BUT RADAR SHOWS A COUPLE SMALL SHOWERS ALONG MANITOBA-NORTH DAKOTA-SASK BORDER REGION AT 00Z. WITH SOME MID CLOUD ACTIVITY IN THIS AREA DID KEEP IDEA OF LOW POP FOR -SHRA ALONG INTL BORDER TONIGHT THOUGH ADJUSTED TIMING A BIT IN NW FCST AREA TO 02Z INSTEAD OF STARTING AT 00Z. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 245 PM CDT THU AUG 20 2015 THE MAIN CHALLENGE WILL BE SEVERE POTENTIAL SATURDAY WITH A POTENT STORM SYSTEM. MODELS ARE COMING INTO BETTER AGREEMENT WITH A SLOWER SOLUTION WITH A CLOSED OFF UPPER LOW...WITH SIGNIFICANT WRAP AROUND PRECIP IN THE NORTH AS WELL SAT NIGHT INTO SUNDAY...ALONG WITH STRONG WINDS. FOR TONIGHT...THERE WILL BE A WEAK WAVE/UPPER SPEED MAX SKIRTING THE CANADIAN BORDER WITH A 25-30KT LLJ AND SOME WEAK ELEVATED INSTABILITY. THE CAM MODELS INDICATE A WEAK BAND OF SHOWERS ACROSS THE NORTH INTO FRIDAY MORNING. ON FRIDAY...THERE COULD BE SOME MORNING SHOWERS IN NW MN...OTHERWISE IT SHOULD BE DRY AND WARM WITH HIGHS INTO THE MID...PERHAPS UPPER 80S. FOR FRI NIGHT...ELEVATED INSTABILITY AND DEEP MOISTURE WILL INCREASE THROUGHOUT THE AREA. EXPECT ISOLATED TO SCATTERED SHOWERS AND STORMS TO DEVELOP IN ALL AREAS...WITH THE BEST THREAT IN THE FAR NORTH LATE. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 245 PM CDT THU AUG 20 2015 ON SATURDAY...AN STRONG UPPER LOW WILL MOVE INTO THE DAKOTAS WITH A WARM...UNSTABLE AIRMASS OVER THE FORECAST AREA. THERE WILL BE A FRONT MOVING FROM WEST TO EAST ALONG WITH SFC LOW PRESSURE LIKELY MOVING ACROSS THE NORTHERN VALLEY SAT AFTERNOON. DEEP LAYERED SHEAR VALUES SHOULD INITIALLY LAG THE WARM SECTOR...BUT MAY CATCH UP BY AFTERNOON. THIS INCREASING DEEP LAYERED SHEAR ALONG WITH AMPLE INSTABILITY AND MLCAPE AROUND 2000 J/KG IN THE EAST SHOULD MEAN SOME SEVERE STORMS. REFER TO THE SPC DAY 3 OUTLOOK THAT HAS AS SLIGHT RISK THAT MAY BE INCREASED EVEN FURTHER GIVEN THE VERY STRONG UPPER SYSTEM AND SHEAR/INSTABILITY FIELDS. THIS HAS THE POTENTIAL TO BE A FAIRLY SIGNIFICANT SEVERE WEATHER EVENT...STAY TUNED. FOR SAT NIGHT AND SUNDAY...WINDS WILL INCREASE ON THE BACK SIDE OF DEPARTING LOW PRESSURE. THE GFS IS VERY STRONG WITH WINDS WITH NEARLY 65KT TO MIX FROM 850MB LATE SAT NIGHT INTO SUNDAY. THERE WILL ALSO BE A SIGNIFICANT DEFORMATION SHOWER BAND THAT COULD PRODUCE AN INCH OF RAIN IN THE NORTH...WHICH WOULD BE WELCOME SINCE IT HAS BEEN VERY DRY. TEMPS ON SUNDAY WILL BE COOL IN THE 60S AND IT WILL BE A WINDY DAY. FOR SUNDAY NIGHT THROUGH THURSDAY...THE DEPARTING LOW PRESSURE SYSTEM SHOULD BE PUSHING THROUGH THE MINNESOTA ARROWHEAD AND WESTERN ONTARIO FROM SUNDAY NIGHT INTO MONDAY MORNING...WITH A STRONG PUSH /NORTHWEST FLOW/ OF CANADIAN POLAR AIR DROPPING INTO THE AREA IN ITS WAKE. SEASONABLY COOLER AND DRIER AIR SHOULD PERSIST MONDAY INTO TUESDAY... WITH A RETURN SOUTHERLY FLOW SETTING UP ACROSS THE AREA AFTER MIDDAY TUESDAY. THEN BOTH THE GFS AND ECMWF SHOW AN INCREASINGLY WARMER AND WETTER PATTERN FROM WEDNESDAY INTO THURSDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 706 PM CDT THU AUG 20 2015 VFR CONDITIONS THRU THE PD. A FEW HIGH BASED CU THIS EVENING WILL DISSIPATE AND TO BE REPLACED BY A LITTLE CIRRUS...WITH THICKER CIRRUS AND SOME MID CLOUD OVERNIGHT ALONG THE INTL BORDER. SOUTH WINDS WILL DIMINISH THIS EVENING BUT REMAIN GENERALLY SOUTHERLY 5 TO 12 KTS THRU FRIDAY. NO PRECIP AT ANY TAF SITE. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...RIDDLE SHORT TERM...DK LONG TERM...GUST/DK AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1221 AM CDT WED AUG 19 2015 .UPDATE... ISSUED AT 1216 AM CDT WED AUG 19 2015 A FEW MINOR CHANGES WERE MADE TO THE PRECIPITATION FORECAST AND TEMPERATURES. ISOLATED SHOWERS CONTINUE ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE HRRR AND RAP CONTINUE THESE SHOWERS THROUGH THE NIGHT. THEREFORE...EXTENDED BY SPATIALLY AND TEMPORALLY PRECIP CHANCES WEST AND CENTRAL. A BAND OF STEADY RAIN CONTINUED ACROSS SOUTHEAST NORTH DAKOTA. THIS BAND WILL SLOWLY MOVE OUT BY DAYBREAK. TEMPERATURES WERE FALLING A LITTLE FASTER THAN PREVIOUSLY FORECAST ACROSS THE NORTH WHERE CLOUDS HAVE THINNED OUT. LOWERED OVERNIGHT LOWS A FEW DEGREES. UPDATE ISSUED AT 935 PM CDT TUE AUG 18 2015 SHOWERS AND ISOLATED THUNDERSHOWERS IN WESTERN NORTH DAKOTA WERE DIMINISHING THIS PAST HOUR AFTER SUNSET. EXPECT ONLY ISOLATED LIGHT SHOWERS IN THE NEXT HOUR OR TWO IN THE WEST. MEANWHILE THE SURFACE LOW HAD MOVED NORTHEASTWARD INTO SOUTHERN MINNESOTA IN THE PAST FEW HOURS. THE RAIN SHIELD ASSOCIATED WITH THE WRAP AROUND PRECIPITATION WAS PERSISTING OVER EASTERN PORTIONS OF LAMOURE AND DICKEY COUNTIES. EXPECT THESE SHOWERS TO END FROM WEST TO EAST BY LATE EVENING OR SHORTLY AFTER MIDNIGHT. OTHERWISE...ADJUSTED HOURLY TEMPERATURES BASED ON LATEST TRENDS. CURRENT FORECAST REMAINS ON TRACK. UPDATE ISSUED AT 631 PM CDT TUE AUG 18 2015 CURRENTLY...A SURFACE LOW WAS OVER THE BORDER OF IOWA/MINNESOTA/SOUTH DAKOTA...WITH HIGH PRESSURE OVER THE FRONT RANGE OF MONTANA. THE UPPER LEVEL LOW WAS OVER EASTERN SOUTH DAKOTA. A LARGE AREA OF RAIN SHOWERS CONTINUED NORTH AND WEST OF THE SURFACE LOW...WHERE OVERCAST SKIES WERE KEEPING TEMPERATURES IN THE 50S AND 60S...AS IN THE JAMES VALLEY. FARTHER WEST WHERE THERE WERE BREAKS IN THE OVERCAST...TEMPERATURES WERE IN THE UPPER 60S AND INTO THE 70S. ALSO OVER WESTERN NORTH DAKOTA THERE WAS ENOUGH SURFACE HEATING AND UPPER LEVEL INSTABILITY FOR SOME ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. NO SEVERE WEATHER EXPECTED WITH THESE STORMS...WITH UPPER LEVEL SUPPORT MINIMAL...AND WEAK SHEAR. ONLY CHANGE IN THIS UPDATE WAS TO INCREASE PRECIP CHANCES IN LAMOURE/DICKEY/MCINTOSH COUNTIES WITH CURRENT RADAR LOOPS INDICATING MORE COVERAGE IN SHOWERS. MINOR HOURLY TEMPERATURE ADJUSTMENTS AS WELL. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 311 PM CDT TUE AUG 18 2015 CURRENT SURFACE ANALYSIS PLACES LOW OVER NORTHWESTERN IOWA INTO SOUTHWESTERN MINNESOTA WITH HIGH PRESSURE WORKING INTO THE LEE OF THE NORTHERN ROCKIES. UPPER LEVEL ANALYSIS PLACES CUT OFF LOW OVER EASTERN SOUTH DAKOTA WITH RIDGE OFF THE WEST COAST. BROAD AREA OF RAINFALL CONTINUES OVER NORTHEAST SOUTH DAKOTA WITH THIS SYSTEM WITH SOME PRECIPITATION ON THE NORTHERN FRINGES CONTINUING OVER THE SOUTHERN JAMES RIVER VALLEY. WEAK SHORT WAVE NOTED IN CYCLONIC FLOW BEHIND THE LOW IS RESULTING IN SOME SHOWERS/THUNDERSTORMS OVER WESTERN NORTH DAKOTA. FOR THE REST OF THIS AFTERNOON INTO THIS EVENING...UPPER LOW WILL SLOWLY LIFT TOWARDS THE NORTHEAST WITH RAIN OVER THE SOUTHERN JAMES RIVER VALLEY SLOWLY TAPERING OFF FROM WEST TO EAST. AS FOR THE PRECIPITATION OVER WESTERN NORTH DAKOTA...LATEST HIGH-RES GUIDANCE SUGGESTS THAT IT SHOULD BE DIMINISHING BY AROUND MID- EVENING. OTHERWISE...A COOL NIGHT IS IN STORE WITH MOST LOCATIONS DIPPING INTO THE 40S. ON WEDNESDAY...UPPER LOW LIFTS OVER MINNESOTA WITH RIDGING DEVELOPING OVER OUR AREA. EXPECT DRY CONDITIONS WITH TEMPERATURES REMAINING AROUND 10 DEGREES BELOW AVERAGE. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 311 PM CDT TUE AUG 18 2015 WARMING TEMPERATURES AND THUNDERSTORM CHANCES FRIDAY AFTERNOON THROUGH SATURDAY HIGHLIGHT THE EXTENDED RANGE. FOR WEDNESDAY NIGHT...AN UPPER LEVEL LOW LOCATED OVER NORTHERN MINNESOTA WILL CONTINUE TO PUSH EAST WITH A RIDGE BUILDING FROM THE WEST...KEEPING THE DAKOTAS IN NORTHWEST FLOW WITH DIMINISHING CLOUDS. TEMPERATURES WILL BEGIN TO WARM ON THURSDAY...WITH HIGHS GENERALLY REACHING INTO THE 80S AS WE START TO TRANSITION INTO A BRIEF PERIOD OF NEAR ZONAL FLOW. A POTENT SHORTWAVE TROUGH WILL APPROACH THE COUNTY WARNING AREA FROM THE PACIFIC NORTHWEST BY LATE FRIDAY AFTERNOON...BRINGING WITH IT HIGH TEMPERATURES NEAR 90...MOISTURE RETURN...AND SOUTHWEST FLOW. AN ASSOCIATED COLD FRONT WILL MAKE ITS WAY ACROSS THE REGION OVERNIGHT FRIDAY AND INTO SATURDAY...BRINGING CHANCES OF SCATTERED SHOWERS AND THUNDERSTORMS. AS FAR AS SEVERE WEATHER CHANCES GO...THERE IS STILL QUITE A BIT OF UNCERTAINTY. TODAYS 12Z ECMWF IS A BIT QUICKER WITH THE UPPER LEVEL WAVE PROPAGATION...AND IS MORE ROBUST WITH MOISTURE RETURN/INSTABILITY WHEN COMPARED WITH THE 12Z GFS. THEREFORE...STRONG TO SEVERE STORMS WOULD BE MORE LIKELY LATE FRIDAY AFTERNOON AND INTO SATURDAY IF THE EUROPEAN SOLUTION WERE TO VERIFY. WILL HAVE TO WATCH MODEL TRENDS AS THE TIME FRAME GROWS CLOSER. SATURDAY WILL FEATURE ANOTHER COOL DOWN AFTER THE FRONTAL PASSAGE...WITH SOME LINGERING SHOWERS AND THUNDERSTORMS POSSIBLE INTO SUNDAY. THE WESTERN RIDGE WILL BEGIN TO BUILD EAST AGAIN AT THE BEGINNING OF WEEK...PROMOTING ANOTHER WARMUP FOR THE AREA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1216 AM CDT WED AUG 19 2015 VFR CONDITIONS AT ALL TAF SITES THROUGH THE TAF PERIOD. ISOLATED SHOWERS ARE POSSIBLE AT KDIK/KBIS LATE TONIGHT...BUT COVERAGE AND CONFIDENCE NOT HIGH ENOUGH TO WARRANT MENTION IN THE TAF. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AJ SHORT TERM...JJS LONG TERM...ZH AVIATION...AJ
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1149 PM CDT TUE AUG 18 2015 .UPDATE... ISSUED AT 1146 PM CDT TUE AUG 18 2015 HRRR AND OTHER MODELS CONTINUE TO INDICATE THE POP GRADIENT AND NW EDGE OF RAIN IN GOOD SHAPE IN THE GRIDS AND NO FURTHER CHANGES REQUIRED. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 242 PM CDT TUE AUG 18 2015 FORECAST CHALLENGE FOR TONIGHT IS WHICH HI RES MODEL TO FOLLOW FOR EVOLUTION OF LOW PRESSURE SYSTEM OVER FAR SERN SD AS IT MOVES EAST AND THEN NORTH...CLIPPING SOUTHERN AND EASTERN PORTIONS OF THE CWA. HRRR HAS CONSISTENTLY VERIFIED WITH PLACEMENT OF PRECIP BEST EACH HOUR...ALTHOUGH EARLIER RUNS THAT SPREAD RAIN AS FAR NORTH AS FARGO WERE THOUGHT TO BE OVERLY BULLISH AND I HAD FAVORED THE NMM/ARW...WHICH KEPT PRECIP FURTHER SOUTH WITH THE NE FLOW IN SFC-H850 LAYER. HOWEVER...15Z HRRR RUN DID A VERY GOOD JOB WITH PLACEMENT OF PRECIP VERIFIED BY 19Z RADAR IMAGERY. THEREFORE WILL CONTINUE HRRR TRENDS THROUGH THE EVENING THROUGH 06Z...THEN A FCST BLEND THROUGH END OF EVENT FOR OUR CWA. TONIGHT AND TOMORROW...PRECIP OVER SOUTHWEST MN WILL CONTINUE TO LIFT FROM SW MN INTO W CNTRL MN...HOWEVER WITH SFC LOW MOVING NE...DO NOT EXPECT RAIN TO LIFT MUCH FURTHER NORTH THAN HILLSBORO WITHIN THE RRV. LOW BEGINS TO LIFT MORE NORTHWARD AFTER MIDNIGHT...EVENTUALLY MOVING OVER LAKE SUPERIOR WED AFTN. QUESTION IS HOW MUCH PRECIP WILL BACK INTO NW MN...AND CURRENT TRENDS ARE KEEPING MOST OF THE NORTHERN VALLEY AND KITTSON/MARSHALL/NW POLK COUNTIES DRY. 00Z ECMWF WAS THE FURTHEST WEST AND HAVE DISCOUNTED IT...PREFERRING A GFS/GEM/NAM BLEND FOR WEDNESDAY POPS. HIGHEST RAINFALL RATES WITHIN DEFORMATION ZONE SHOULD BE OVER CNTRL MN...WHERE HPC QPF IS SHOWING UP TO TWO AND A QUARTER INCHES OF PRECIP WITH A SHARP...DECLINING GRADIENT WESTWARD INTO THE SOUTHERN VALLEY. CURRENT PRECIP TOTAL THOUGHTS ARE AROUND HALF AN INCH IN FARGO...LITTLE IF ANY IN GRAND FORKS...RISING TO AROUND 2 INCHES AS FAR EAST AS PARK RAPIDS. WED NIGHT...SYSTEM PULLS OUT OF LAKE SUPERIOR REGION INTO CNTRL ONTARIO...SLOWLY PULLING PRECIP OUR OF FAR EAST AND NORTHEASTERN ZONES BY 12Z THU. CLEARING IN THE WEST...IN ADDITION TO RELAXING PRESSURE GRADIENT WINDS...WILL ALLOW OVERNIGHT LOWS TO FALL INTO THE UPPER TO MID 40S ACROSS MOST OF THE REGION...WARMEST IN THE FAR EAST WHERE CLOUD COVER WILL LINGER OVERNIGHT. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 242 PM CDT TUE AUG 18 2015 THURSDAY AND FRIDAY...HIGH PRESSURE MOVES INTO REGION BRINGING INCREASED SOLAR AND REBOUNDING TEMPERATURES TO NEAR SEASONAL NORMS ON THURSDAY. RETURN FLOW SETS UP THU NIGHT INTO FRIDAY AND WEAK SOUTHERLY FLOW THROUGH THE DAY FRIDAY WILL RESULT IN TEMPS CLIMBING BACK INTO THE MID 80S. THU NIGHT INTO FRIDAY...PASSING MID LEVEL TROUGH SATURDAY WILL DRAG ANOTHER COLD FRONT ACROSS THE REGION. TIMING OF FRONT WOULD BRING BEST T CHANCES ACROSS EASTERN HALF OF THE FA. SUNDAY WILL BE COOLER FOLLOWED BY MODERATING TEMPERATURES INTO EARLY NEXT WEEK WITH DRY CONDITIONS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1146 PM CDT TUE AUG 18 2015 RAIN WILL CONTINUE FARGO-BEMIDJIJ AREAS THROUGH WEDNESDAY MORNING (FAR) AND INTO EARLY AFTERNOON (BJI). SOME CONCERN ESP AT BJI OF LOWER MVFR OR MAYBE IFR CIGS TOWARD SUNRISE AS DRY AIR ALOFT MOVES IN. SEEING LOWER CIGS TO THE SOUTH MOVING INTO WADENA AND POINTS SOUTH. OTHERWISE VFR AT THE REST OF THE TAF SITES...THOUGH WOULD BE SUPRISED TO SEE BRIEF MVFR CIG AT FARGO NR SUNRISE. WILL MAINTAIN DRY GFK-TVF-DVL. NORTH WINDS INCREASING TO 12 TO 25 KTS AT MOST SITES AS SURFACE LOW MOVES NORTHEAST TOWARD DULUTH AND NW WISCONSIN. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...RIDDLE SHORT TERM...SPEICHER LONG TERM...SPEICHER/VOELKER AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
928 PM EDT THU AUG 20 2015 .SYNOPSIS... A COLD FRONT HAS MOVED EAST OF THE AREA WITH COOLER AND DRIER AIR SETTLING OVER THE AREA BEHIND IT. A SURFACE AREA OF HIGH PRESSURE TO OUR WEST WILL MOVE INTO THE AREA FRIDAY AND LINGER THROUGH THE WEEKEND. THE NEXT CHANCE FOR RAIN WILL BE SUNDAY NIGHT INTO MONDAY WHEN A COLD FRONT ARRIVES. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... UPPER TROUGH WILL LIFT ACROSS THE CENTRAL GREAT LAKES OVERNIGHT. THERE WILL BE SOME INCREASED LIFT OVER THE LAKE AS THE COOLER AIR ARRIVES IN THE WAKE OF THE TROUGH. THERE COULD BE A FEW SHOWERS THAT DEVELOP FROM THE ERIE AREA NORTHWARD INTO NY STATE. HOWEVER THE MAIN IMPACT WILL BE AN INCREASE OF CLOUD COVER FROM CLEVELAND TO ERIE THROUGH THE EVENING. PREVIOUS DISCUSSION... THE WATER VAPOR SATELLITE IMAGERY DISTINCTLY DEFINES THE TROUGH OVER THE UPPER LAKES AND THE DRIER AIR FILTERING INTO THE OHIO VALLEY ALOFT. AT THE SURFACE HIGH PRESSURE OVER THE PLAINS WILL SLIDE EAST OVERNIGHT AND LINGER OVER THE AIR INTO THE WEEKEND. DEW POINTS HAVE DROPPED 10-15F SINCE THIS MORNING...WHICH WILL SUPPORT NOTABLY COOLER TEMPERATURES OVERNIGHT. NCAR ENSEMBLES ALONG WITH THE RUC ARE SUGGESTING DEW POINTS INTO THE UPPER 40S OVERNIGHT...HOWEVER NOT SEEING ANY 40S UPSTREAM OR NEAR THE AREA DESPITE A FAIR AMOUNT OF AFTERNOON MIXING. WITH DEW POINTS IN THE LOW TO MID 50S...MOSTLY CLEAR SKIES...AND WINDS TAPERING OFF AFTER DARK...WILL KEEP TEMPERATURES IN THE LOW TO MID 50S OVERNIGHT. ONLY FLY IN THE OINTMENT WILL BE ANY POTENTIAL DEVELOPMENT OVER THE LAKE AS THE H850 AND WATER TEMPERATURES DIFFER BY ABOUT 14C. THE BEST CHANCE FOR ANYTHING TO DEVELOP WILL BE BETWEEN 06 AND 15Z FRI...BUT AT THIS TIME WILL KEEP ONLY ISOLATED RAIN OVER THE EASTERN PORTIONS OF THE LAKE AND NOT INTO ERIE PA. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY NIGHT/... AS THE HIGH BUILDS OVERHEAD FRIDAY ANY LAKE ACTIVITY WILL BE SHUT DOWN BY THE DRIER AIR AND THE SINKING INVERSION. LOOK FOR SUNNY SKIES AND TEMPERATURES IN THE 70S. THE HIGH WILL SHIFT EAST ON SATURDAY WHICH WILL SUPPORT SOME WEAK RETURN FLOW WHICH WILL CONTINUE INTO SUNDAY. MEANWHILE THE NW FLOW ALOFT WILL TURN TO THE SW WITH WARMER TEMPERATURES ADVECTING IN WITH H850 REACHING 12C WHICH WILL TRANSLATE INTO GRADUAL WARMING AT THE SURFACE. THE NEXT CHANCE FOR PRECIPITATION WILL BE ASSOCIATED WITH ANOTHER MID LEVEL TROUGH MOVING OUT OF THE ROCKIES. AN ASSOCIATED COLD FRONT WILL REACH THE AREA SUNDAY NIGHT AND WITH WARMER/MOIST AIR AND AN INCREASE IN THE LOW LEVEL JET CAN`T RULE OUT SOME THUNDERSTORMS. && .LONG TERM /MONDAY THROUGH THURSDAY/... A COLD FRONT WILL BE MOVING THROUGH THE EASTERN EDGE OF THE AREA MONDAY MORNING ALONG WITH A FEW LINGERING SHOWERS. COLD ADVECTION WILL OVERSPREAD THE REGION IN THE WAKE OF THE COLD FRONT. THE UPPER AIR PATTERN WILL EXHIBIT A LONG WAVE TROUGH OVER ONTARIO EARLY IN THE EXTENDED WITH THIS FEATURE LIFTING FARTHER NORTH AND ALLOWING A MORE ZONAL FLOW TO DEVELOP. BELOW NORMAL TEMPERATURES ARE EXPECTED WITH GENERALLY DRY CONDITIONS BUT A FEW SHOWERS ARE POSSIBLE WEDNESDAY AFTERNOON AND EVENING MAINLY OVER NORTHWEST PA WHERE A MOIST CYCLONIC FLOW ALOFT ALONG WITH WELL MIXED ADIABATIC CONDITIONS ARE EXPECTED. CONDITIONS WILL WARM ON THURSDAY AND FRIDAY AS THE 850 MB TEMPERATURES RISE TO MORE SEASONAL LEVELS AND MORE SUNSHINE PREVAILS. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... COOL AIR ALOFT WILL SUPPORT LAKE EFFECT CLOUDS TONIGHT AND FRI MORNING OVER LAKE ERIE. A TROUGH MOVING EAST ACROSS LAKE ERIE WILL CAUSE THE MEAN LOW LEVEL WINDS TO VEER TO WNW WHICH WILL PROBABLY PRODUCE SCT TO BKN CONDITIONS AT ERI LATE TONIGHT AND FRI MORNING. HIGH PRESSURE PUSHES NE OVER OH FOR FRI AFTERNOON WHICH SHOULD LEAD TO SLOW DISSIPATION OF THE LAKE EFFECT CLOUDS FRI AFTERNOON. DAYTIME HEATING MAY PRODUCE SCT CU IN OTHER PARTS OF THE EAST BY MIDDAY FRI BUT THIS CU WILL DISSIPATE BY EARLY EVENING. WINDS WILL CONTINUE TO DIMINISH NEXT FEW HOURS AS TEMPS COOL AND AIRMASS STABILIZES EXCEPT WINDS MAY CONTINUE TO RUN 8 TO 10 KNOTS AT ERI FOR MUCH OF THE NIGHT. OUTLOOK...NON VFR CONDITIONS POSSIBLE SUNDAY NIGHT WITH THE PASSAGE OF A COLD FRONT AND POSSIBLE SHOWERS AND THUNDERSTORMS. && .MARINE... SMALL CRAFT CONDITIONS PREVAIL IN THE WAKE OF THE COLD FRONT THAT HAS SWEPT EAST THROUGH THE REGION. A RATHER STRONG PRESSURE GRADIENT FOR SUMMER ALONG WITH COLD ADVECTION ALOFT WILL ALLOW MIXING OF HIGHER MOMENTUM AIR TO THE SURFACE. WITH 850 MB TEMPERATURES EXPECTED TO DROP TO NEAR 10C AND LAKE SURFACE TEMPERATURES FROM 22-24C... NEAR ADIABATIC LAPSE RATE IS EXPECTED OVER THE LAKE WHICH WILL PERMIT DEEP MIXING AND STRONGER WINDS TO PREVAIL. WILL CONTINUE WITH SMALL CRAFT ADVISORY THROUGH 08Z EAST OF THE ISLANDS. IT MAY NEED TO BE EXTENDED SLIGHTLY LONGER IN THE EASTERN HALF OF THE LAKE WHERE THE STRONGER PRESSURE GRADIENT WILL LINGER. HIGH PRESSURE WILL GRADUALLY BUILD SOUTH OF THE LAKE FRIDAY AND THEN REMAIN OVER THE REGION INTO THE WEEKEND. WINDS WILL CONTINUE TO DIMINISH FRIDAY AND BE LIGHT ON SATURDAY. SOUTHERLY WINDS WILL INCREASE ON SUNDAY AS ANOTHER FRONTAL BOUNDARY APPROACHES WITH ITS PASSAGE EXPECTED SUNDAY NIGHT. SMALL CRAFT CONDITIONS WILL LIKELY DEVELOP IN THE WAKE OF THAT FRONTAL PASSAGE GIVEN THE COOLING ALOFT DOWN TO JUST BELOW 10C AT 850 MB. WINDS WILL DECREASE ON TUESDAY AS HIGH PRESSURE BUILDS INTO THE REGION. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT FRIDAY FOR LEZ144>149. && $$ SYNOPSIS...JAMISON NEAR TERM...JAMISON/MULLEN SHORT TERM...JAMISON LONG TERM...LAPLANTE AVIATION...ADAMS MARINE...ADAMS/LAPLANTE
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1111 AM EDT WED AUG 19 2015 .SYNOPSIS... WARM AND HUMID AIR TODAY WILL ALLOW FOR SHOWERS AND THUNDERSTORMS TO DEVELOP...IN ADVANCE OF A COLD FRONT THAT WILL MOVE THROUGH THE AREA THURSDAY MORNING. MUCH DRIER CONDITIONS ARE EXPECTED ON THURSDAY AND FRIDAY...WITH SLIGHTLY COOLER TEMPERATURES AND LESS HUMIDITY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A PLUME OF HIGHER PWATS...AROUND 2"...WILL CONTINUE TO ADVECT NORTHEAST INTO THE REGION THIS AFTERNOON. CURRENT RADAR MOSAIC CONTINUES TO SHOW AN EMBEDDED DISTURBANCE NEAR THE TRI-STATE REGION WITH SHOWERS...AND A FEW LIGHTNING STRIKES. THIS FEATURE WILL MOVE EAST/NORTHEAST INTO THE AFTERNOON. WITH DESTABILIZATION AHEAD OF IT...SCATTERED TO LIKELY CONVECTION SHOULD FILL IN ACRS OUR EASTERN AREAS. FOR LATER THIS AFTERNOON INTO THIS EVENING...HIGH RESOLUTION MODELS STILL ARE ADVERTISING A POTENTIAL PREFRONTAL TROF TO MOVE INTO THE AREA. THIS WILL BECOME THE FOCUS FOR MORE SHOWERS AND EMBEDDED THUNDERSTORMS. OVERALL BULK SHEAR WILL BE WEAK...SO ORGANIZATION TO THE CONVECTION WILL BE LACKING. IN ADDITION...MLCAPES MAY ONLY RANGE FROM 800-1200 J/KG AT PEAK HEATING WITH THE HIGHEST IN THE EAST. ALSO...WITH HIGH PWATS...DCAPES WILL BE LOW (LACK OF MID LEVEL DRY AIR). ALL IN ALL... ONLY A MARGINAL RISK FOR SEVERE TODAY WITH PERHAPS GUSTY WINDS DUE TO PCPN LOADING. FREEZING LEVELS WILL REMAIN HIGH TO KEEP HAIL SIZE IN CHECK. IF ANYTHING...LOCALLY HEAVY RAINFALL MAY END UP BEING THE MAIN CONCERN GIVEN HIGH PWATS. HIGHS TODAY WILL BE PCPN AND CLOUD DEPENDENT WITH THE HIGHER VALUES FAVORING OUR EAST AS SOME INSOLATION OCCURS BEFORE CLOUDING OVER. WILL CONTINUE WITH LOWER TO MID 80S. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... THIS EVENING THE UPPER LEVEL LOW OVER MINNESOTA WILL START TO PULL NORTH AS ANOTHER LOW DIVES SOUTH NEAR THE HUDSON BAY. AT THE SAME TIME A COLD FRONT WILL BE APPROACHING FROM THE WEST. EXPECTING COVERAGE TO AGAIN INCREASE THIS EVENING AS MODELS ARE HINTING AT SOME LOW LEVEL CONVERGENCE FROM A LLJ MOVING IN FROM THE SOUTHWEST. THE MAIN QUESTION WILL BE WHERE AND IF THE JET SETS UP. ALSO AT 250 MB A SPLITTING JET STRUCTURE CAN BE FOUND AROUND KENTUCKY/ TENNESSEE JUST SOUTH OF THE AREA. IN NORTHERN OHIO THE UPPER LEVEL FLOW REMAINS MORE UNIFORM SPATIALLY (MUCH LESS UPPER LEVEL DIFFLUENCE). DUE TO THE MENTIONED ABOVE HIGH RES MODELS SHOW MORE COVERAGE IN CONVECTION THROUGH OUR CWA AND SOUTH OF OUR CWA WHILE A BREAK COULD POSSIBLY EXIST IN NORTHERN OHIO AND MICHIGAN. PWATS ARE STILL EXPECTED TO BE AROUND 1.90" AHEAD OF THE FRONT THOUGH AND WITH UPPER LEVEL SUPPORT DECIDED TO LEAVE POP DISTRIBUTION AS IS. REGARDING SEVERE POTENTIAL... INSTABILITY WILL WANE AFTER THE SUNSETS WHILE BY FAR THE BEST SPEED SHEAR LIES JUST BEHIND THE FRONT. LAPSE RATES ALSO DON`T APPEAR PARTICULARLY FAVORABLE... THUS THE MARGINAL RISK BY SPC SEEMS SUFFICIENT. TIMING OF THE FRONTAL PASSAGE HAS ALSO BEEN SLOWING THE LAST COUPLE OF DAYS. THE EURO AND NAM ARE NOW MORE IN AGREEMENT WITH A SLOWER FRONTAL PASSAGE. THEY HAVE THE FRONT PASSING THROUGH CINCINNATI AROUND 12Z (8 AM) WHILE CLEARING THE CWA 6 HRS LATER. BEHIND THE FRONT MUCH LOWER PWAT AIR AND FALLING DEWPOINTS WILL BE USHERED IN. 850 TEMPS ALSO FALL FROM AROUND 16/ 15 DEGREES C TO NEAR 11 DEGREES C BY THURSDAY EVENING. THIS WILL KEEP HIGH TEMPS IN THE MID TO UPPER 70S ACROSS THE REGION THURSDAY. FRIDAY MORNING HIGH PRESSURE WILL MOVE OVERHEAD ALLOWING FOR TEMPERATURES TO QUICKLY FALL AND BOTTOM OUT IN THE MID 50S. THE NAM HAS CONTINUED TO SHOW SOME CIRRUS POSSIBLE ACROSS OUR SOUTHEASTERN ZONES IN ASSOCIATION WITH A WEAK DISTURBANCE WHILE THE GFS AND EURO SHOW THE CIRRUS FURTHER EAST. FOR NOW HAVE KEPT CIRRUS OUT OF THE AREA FRIDAY MORNING ALLOWING FOR MAX RADIATIONAL COOLING. FRIDAY AFTERNOON WILL BE BEAUTIFUL WITH HIGHS LIKELY RIGHT AROUND OR JUST BELOW 80 DEGREES AS 850 MB TEMPS REMAIN AROUND 10 OR 11 DEGREES C. DEWPOINTS WILL ALSO LIKELY MIX OUT ALLOWING FOR RELATIVE HUMIDITY PERCENTAGES IN THE UPPER 30S. && .LONG TERM /SATURDAY THROUGH TUESDAY/... THE NEXT SYSTEM WILL APPROACH AND MOVE THROUGH THE REGION SUNDAY INTO SUNDAY NIGHT. MODELS ARE IN DECENT AGREEMENT WITH THIS SYSTEM AND THEREFORE WENT WITH LIKELY PRECIPITATION CHANCES. HIGH PRESSURE AND DRY CONDITIONS WILL RETURN TO THE REGION MONDAY THROUGH TUESDAY. HIGH TEMPERATURES ARE GENERALLY EXPECTED TO BE SLIGHTLY BELOW NORMAL EXCEPT ON SUNDAY WHEN HIGH TEMPERATURES ARE EXPECTED TO BE SLIGHTLY ABOVE NORMAL. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... A THUNDERSTORM COMPLEX IS MOVING EAST ACROSS SOUTHERN ILLINOIS AND INTO SOUTHWEST INDIANA ATTM AND WE ARE BEGINNING TO SEE SOME SCATTERED DEVELOPMENT OUT AHEAD OF IT ACROSS WESTERN KENTUCKY AND SOUTH CENTRAL INDIANA. THE LATEST HRRR SEEMS TO HAVE A DECENT HANDLE ON THIS...BUT IS PERHAPS A COUPLE OF HOURS SLOW WITH ITS POSITIONING. THIS NEW DEVELOPMENT IS IN AN AREA OF BETTER INSTABILITIES ALONG THE OHIO RIVER SO THINK THIS MAY BECOME THE MORE DOMINANT PCPN FEATURE OVER THE NEXT HOUR OR TWO. KCVG AND KLUK SHOULD HAVE THE BEST CHANCE OF BEING AFFECTED BY THIS IN THE NEAR TERM AS IT CONTINUES TO WORK ITS WAY EASTWARD THROUGH MID MORNING. THE CONVECTIVE ALLOWING MODELS ARE GENERALLY TRYING TO SHOW AT LEAST SOME ADDITIONAL SCATTERED DEVELOPMENT ELSEWHERE ACROSS THE AREA IN ASSOCIATION WITH A PRE FRONTAL TROUGH LATER THIS MORNING AND INTO EARLY TO MID AFTERNOON. TIMING IS SOMEWHAT DIFFICULT THOUGH SO WILL GENERALLY HAVE A VCTS THROUGH MUCH OF THE DAY AND THEN TRY TO INCLUDE SOME TEMPO GROUPS FOR THE MORE FAVORABLE TIME PERIODS. WE MAY THEN GET INTO A BIT OF A LULL LATER THIS AFTERNOON INTO EARLY EVENING BEFORE BETTER FORCING ASSOCIATED WITH THE ACTUAL FRONT BEGINS TO WORK IN FROM THE WEST. THERE ARE STILL SOME TIMING DIFFERENCES BETWEEN THE MODELS WITH THE FRONT FOR TONIGHT...BUT OVERALL EXPECT TO TRANSITION TO MORE WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS HEADING INTO TONIGHT. PREVAILING CIGS WILL DROP DOWN INTO MVFR AND THEN PROBABLY IFR AS THE FRONT APPROACHES/MOVES THROUGH OVERNIGHT. OUTLOOK...THUNDERSTORMS POSSIBLE SUNDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HAINES NEAR TERM...HICKMAN SHORT TERM...HAINES LONG TERM...NOVAK AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
624 AM EDT WED AUG 19 2015 .SYNOPSIS... WARM AND HUMID AIR TODAY WILL ALLOW FOR SHOWERS AND THUNDERSTORMS TO DEVELOP...IN ADVANCE OF A COLD FRONT THAT WILL MOVE THROUGH THE AREA THURSDAY MORNING. MUCH DRIER CONDITIONS ARE EXPECTED ON THURSDAY AND FRIDAY...WITH SLIGHTLY COOLER TEMPERATURES AND LESS HUMIDITY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... EARLIER LINE OF SHOWERS AND THUNDERSTORMS OUT IN INDIANA HAS ALL BUT FIZZLED THIS MORNING WITH MORE CONVECTION CURRENTLY FIRING IN SOUTHERN ILLINOIS. HIGH RES MODELS ARE SHOWING THIS CONVECTION CONTINUING TO WEAKEN AS IT PROGRESSES EASTWARDS BUT MAKING IT TO CINCINNATI LATE MORNING. FORECAST SOUNDINGS FOR THIS AFTERNOON SHOW MOISTURE LEVELS QUICKLY RISING TO NEAR 1.90" WITH K INDEX VALUES PEAKING IN THE UPPER 30S. SHEAR VALUES REMAIN WEAK THIS AFTERNOON WITH SFC TO 6 KM VALUES ONLY AROUND 10 KTS. CAPE VALUES ON BOTH THE GFS AND NAM ARE AROUND 1500 J/KG ON AVERAGE FOR THIS AFTERNOON. IN THE MID LEVELS POCKETS OF PVA ARE FORECASTED TO MOVE ACROSS THE REGION THIS AFTERNOON WHICH WILL SUPPORT POCKETS OF LIFT. HIGH RES MODELS ARE MIXED ON THE AMOUNT OF COVERAGE. THERE DOES APPEAR TO BE A WEAK BOUNDARY THAT SETS UP THIS AFTERNOON SOME WHERE ACROSS THE CWA THOUGH. GIVEN THE ABUNDANT MOISTURE... SUFFICIENT INSTABILITY AND LIFT HAVE PUSHED POPS TO LIKELY THIS AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... THIS EVENING THE UPPER LEVEL LOW OVER MINNESOTA WILL START TO PULL NORTH AS ANOTHER LOW DIVES SOUTH NEAR THE HUDSON BAY. AT THE SAME TIME A COLD FRONT WILL BE APPROACHING FROM THE WEST. EXPECTING COVERAGE TO AGAIN INCREASE THIS EVENING AS MODELS ARE HINTING AT SOME LOW LEVEL CONVERGENCE FROM A LLJ MOVING IN FROM THE SOUTHWEST. THE MAIN QUESTION WILL BE WHERE AND IF THE JET SETS UP. ALSO AT 250 MB A SPLITTING JET STRUCTURE CAN BE FOUND AROUND KENTUCKY/ TENNESSEE JUST SOUTH OF THE AREA. IN NORTHERN OHIO THE UPPER LEVEL FLOW REMAINS MORE UNIFORM SPATIALLY (MUCH LESS UPPER LEVEL DIFFLUENCE). DUE TO THE MENTIONED ABOVE HIGH RES MODELS SHOW MORE COVERAGE IN CONVECTION THROUGH OUR CWA AND SOUTH OF OUR CWA WHILE A BREAK COULD POSSIBLY EXIST IN NORTHERN OHIO AND MICHIGAN. PWATS ARE STILL EXPECTED TO BE AROUND 1.90" AHEAD OF THE FRONT THOUGH AND WITH UPPER LEVEL SUPPORT DECIDED TO LEAVE POP DISTRIBUTION AS IS. REGARDING SEVERE POTENTIAL... INSTABILITY WILL WANE AFTER THE SUNSETS WHILE BY FAR THE BEST SPEED SHEAR LIES JUST BEHIND THE FRONT. LAPSE RATES ALSO DON`T APPEAR PARTICULARLY FAVORABLE... THUS THE MARGINAL RISK BY SPC SEEMS SUFFICIENT. TIMING OF THE FRONTAL PASSAGE HAS ALSO BEEN SLOWING THE LAST COUPLE OF DAYS. THE EURO AND NAM ARE NOW MORE IN AGREEMENT WITH A SLOWER FRONTAL PASSAGE. THEY HAVE THE FRONT PASSING THROUGH CINCINNATI AROUND 12Z (8 AM) WHILE CLEARING THE CWA 6 HRS LATER. BEHIND THE FRONT MUCH LOWER PWAT AIR AND FALLING DEWPOINTS WILL BE USHERED IN. 850 TEMPS ALSO FALL FROM AROUND 16/ 15 DEGREES C TO NEAR 11 DEGREES C BY THURSDAY EVENING. THIS WILL KEEP HIGH TEMPS IN THE MID TO UPPER 70S ACROSS THE REGION THURSDAY. FRIDAY MORNING HIGH PRESSURE WILL MOVE OVERHEAD ALLOWING FOR TEMPERATURES TO QUICKLY FALL AND BOTTOM OUT IN THE MID 50S. THE NAM HAS CONTINUED TO SHOW SOME CIRRUS POSSIBLE ACROSS OUR SOUTHEASTERN ZONES IN ASSOCIATION WITH A WEAK DISTURBANCE WHILE THE GFS AND EURO SHOW THE CIRRUS FURTHER EAST. FOR NOW HAVE KEPT CIRRUS OUT OF THE AREA FRIDAY MORNING ALLOWING FOR MAX RADIATIONAL COOLING. FRIDAY AFTERNOON WILL BE BEAUTIFUL WITH HIGHS LIKELY RIGHT AROUND OR JUST BELOW 80 DEGREES AS 850 MB TEMPS REMAIN AROUND 10 OR 11 DEGREES C. DEWPOINTS WILL ALSO LIKELY MIX OUT ALLOWING FOR RELATIVE HUMIDITY PERCENTAGES IN THE UPPER 30S. && .LONG TERM /SATURDAY THROUGH TUESDAY/... THE NEXT SYSTEM WILL APPROACH AND MOVE THROUGH THE REGION SUNDAY INTO SUNDAY NIGHT. MODELS ARE IN DECENT AGREEMENT WITH THIS SYSTEM AND THEREFORE WENT WITH LIKELY PRECIPITATION CHANCES. HIGH PRESSURE AND DRY CONDITIONS WILL RETURN TO THE REGION MONDAY THROUGH TUESDAY. HIGH TEMPERATURES ARE GENERALLY EXPECTED TO BE SLIGHTLY BELOW NORMAL EXCEPT ON SUNDAY WHEN HIGH TEMPERATURES ARE EXPECTED TO BE SLIGHTLY ABOVE NORMAL. && .AVIATION /10Z WEDNESDAY THROUGH SUNDAY/... A THUNDERSTORM COMPLEX IS MOVING EAST ACROSS SOUTHERN ILLINOIS AND INTO SOUTHWEST INDIANA ATTM AND WE ARE BEGINNING TO SEE SOME SCATTERED DEVELOPMENT OUT AHEAD OF IT ACROSS WESTERN KENTUCKY AND SOUTH CENTRAL INDIANA. THE LATEST HRRR SEEMS TO HAVE A DECENT HANDLE ON THIS...BUT IS PERHAPS A COUPLE OF HOURS SLOW WITH ITS POSITIONING. THIS NEW DEVELOPMENT IS IN AN AREA OF BETTER INSTABILITIES ALONG THE OHIO RIVER SO THINK THIS MAY BECOME THE MORE DOMINANT PCPN FEATURE OVER THE NEXT HOUR OR TWO. KCVG AND KLUK SHOULD HAVE THE BEST CHANCE OF BEING AFFECTED BY THIS IN THE NEAR TERM AS IT CONTINUES TO WORK ITS WAY EASTWARD THROUGH MID MORNING. THE CONVECTIVE ALLOWING MODELS ARE GENERALLY TRYING TO SHOW AT LEAST SOME ADDITIONAL SCATTERED DEVELOPMENT ELSEWHERE ACROSS THE AREA IN ASSOCIATION WITH A PRE FRONTAL TROUGH LATER THIS MORNING AND INTO EARLY TO MID AFTERNOON. TIMING IS SOMEWHAT DIFFICULT THOUGH SO WILL GENERALLY HAVE A VCTS THROUGH MUCH OF THE DAY AND THEN TRY TO INCLUDE SOME TEMPO GROUPS FOR THE MORE FAVORABLE TIME PERIODS. WE MAY THEN GET INTO A BIT OF A LULL LATER THIS AFTERNOON INTO EARLY EVENING BEFORE BETTER FORCING ASSOCIATED WITH THE ACTUAL FRONT BEGINS TO WORK IN FROM THE WEST. THERE ARE STILL SOME TIMING DIFFERENCES BETWEEN THE MODELS WITH THE FRONT FOR TONIGHT...BUT OVERALL EXPECT TO TRANSITION TO MORE WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS HEADING INTO TONIGHT. PREVAILING CIGS WILL DROP DOWN INTO MVFR AND THEN PROBABLY IFR AS THE FRONT APPROACHES/MOVES THROUGH OVERNIGHT. OUTLOOK...THUNDERSTORMS POSSIBLE SUNDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HAINES NEAR TERM...HAINES SHORT TERM...HAINES LONG TERM...NOVAK AVIATION...JGL
AREA FORECAST DISCUSSION
NWS NORMAN OK
100 PM CDT WED AUG 19 2015 .DISCUSSION... THE 18Z AVIATION DISCUSSION IS BELOW. && .AVIATION... ONGOING SHOWERS AND THUNDERSTORMS WILL CONTINUE TO AFFECT KOUN/KLAW/KSPS THIS AFTERNOON. EXPECT PRECIPITATION TO END FROM NORTH TO SOUTH...WITH PRECIPITATION ENDING AT KSPS BY 23Z. PERIODS OF MVFR CONDITIONS CAN BE EXPECTED AT THESE SITES. OTHERWISE...GUSTY NORTHERLY WINDS SHOULD SUBSIDE TO LIGHT AND VARIABLE WITH CLEARING SKIES OVERNIGHT. MAHALE && .PREV DISCUSSION... /ISSUED 1026 AM CDT WED AUG 19 2015/ UPDATE... ADJUSTED PRECIP/WX THROUGH THE AFTERNOON... MINOR ADJUSTMENTS TO TEMPS... DISCUSSION... SHOWERS AND THUNDERSTORMS CONTINUE TO DECREASE IN COVERAGE ACROSS S/SWRN OK AND WRN N TX THIS MORNING. THIS TREND LOOKS TO CONTINUE THROUGH THE AFTN AS THE H700 SHORT WAVE PUSHES EAST... DECREASING MID-LEVEL SUPPORT. BUFR SOUNDINGS SUGGEST DECREASING SHEAR AND INSTABILITY ENVIRONMENT WILL CONTINUE TO EVOLVE ACROSS SRN OK/WRN N TX THROUGH THE EARLY AFTN. HRRR HAS SHOWN RELATIVELY DECENT CONTINUITY THIS AM... WITH SHOWERS AND ISOLATED THUNDER LINGERING THROUGH THE AFTN AND INTO THE EVENING ACROSS SOUTH CENTRAL OK. ADJUSTED HIGH TEMPS SLIGHTLY FOR THIS AFTN... BRINGING OKC TO 67. THROUGH 10AM... ALREADY REACHED 65... AND BEGINNING TO SEE SOME BREAKS IN THE CLOUDS ACROSS NWRN OK. IF A FEW BREAKS DEVELOP OVER CENTRAL OK THIS AFTN... TEMPS COULD EASILY MOVE INTO THE UPPER 60S FOR HIGHS... SO ENJOY. JTK PREV DISCUSSION... /ISSUED 628 AM CDT WED AUG 19 2015/ DISCUSSION... THE 12Z AVIATION DISCUSSION FOLLOWS.... AVIATION... WIDESPREAD RA AND TSRA WILL CONTINUE ALONG...AND IN THE GENERAL VICINITY OF...A STRONG COLD FRONT ACROSS OK AND N TX. SCT SHRA WILL ALSO OCCUR WELL INTO THE COOLER AIR OVER N OK UNTIL HIGH PRESSURE FILLS IN THIS AFTERNOON/EVENING. SCATTERED AREAS OF LOW CLOUDS AND TEMPORARY LOW VISIBILITIES WILL OCCUR NEAR THE NUMEROUS TSRA. AS HIGH PRESSURE CONTINUES TO BUILD INTO OK/N TX THIS EVENING AND OVERNIGHT...THE RAIN WILL BECOME LIMITED TO THE FAR S...AND SKIES WILL BEGIN TO CLEAR IN THE N. BY SUNRISE...EXPECT VFR CONDITIONS AND LIGHT WINDS. AREAS THAT CLEAR BEFORE SUNRISE MAY DEVELOP GROUND FOG. CMS PREV DISCUSSION... /ISSUED 409 AM CDT WED AUG 19 2015/ DISCUSSION... AN UNSEASONABLY STRONG COLD FRONT EXTENDED FROM EAST-CENTRAL TO SOUTHWEST OKLAHOMA EARLY THIS MORNING...WITH AN OUTFLOW BOUNDARY EXTENDING FARTHER TO THE SOUTH...ROUGHLY FROM SHAWNEE TO WICHITA FALLS. MUCH COOLER AND DRIER AIR WAS OVER KANSAS...AND WILL SHIFT SOUTH TODAY AND TONIGHT. THE COMBINED EFFECTS OF THE COOLER/DRIER AIR...AND RAIN FALLING THROUGH IT...WILL RESULT IN TEMPERATURES THAT ARE VERY COOL FOR THIS TIME OF YEAR. RECORD LOW MAXIMUM TEMPERATURES ARE LIKELY ACROSS MUCH OF THE REGION TODAY...AND RECORD LOW MINIMUM TEMPERATURES ARE LIKELY TOMORROW MORNING. THE BALANCE OF THE VARIOUS ELEMENTS AFFECTING TEMPERATURE TODAY IS A MAJOR CHALLENGE...AND TEMPERATURE FORECASTS TODAY SHOULD BE CONSIDERED AS APPROXIMATE...ESPECIALLY HOURLY TEMPERATURES. RAIN CHANCES ARE ALSO PROBLEMATIC TODAY...AS THE EVOLUTION OF THE CURRENT MCS IS UNCLEAR. HAVE GENERALLY FORECAST POPS ABOVE THE OVERALL MODEL GUIDANCE VALUES...ON THE ASSUMPTION THAT THE MCS WILL HOLD TOGETHER AT LEAST THROUGH MID-MORNING. AFTER A DAY OF COOL DRY WEATHER...THE WARM/HUMID AIR WILL RETURN NORTH...BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS FRIDAY. A SERIES OF DISTURBANCES WILL KEEP RAIN IN THE FORECAST UNTIL EARLY NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 69 54 81 61 / 100 10 0 10 HOBART OK 70 54 84 63 / 80 10 0 20 WICHITA FALLS TX 74 57 85 66 / 100 20 0 20 GAGE OK 75 53 82 62 / 30 10 0 10 PONCA CITY OK 73 53 82 61 / 60 10 0 10 DURANT OK 82 59 82 65 / 80 50 10 20 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 04/67/10
AREA FORECAST DISCUSSION
NWS NORMAN OK
1026 AM CDT WED AUG 19 2015 .UPDATE... ADJUSTED PRECIP/WX THROUGH THE AFTERNOON... MINOR ADJUSTMENTS TO TEMPS... && .DISCUSSION... SHOWERS AND THUNDERSTORMS CONTINUE TO DECREASE IN COVERAGE ACROSS S/SWRN OK AND WRN N TX THIS MORNING. THIS TREND LOOKS TO CONTINUE THROUGH THE AFTN AS THE H700 SHORT WAVE PUSHES EAST... DECREASING MID-LEVEL SUPPORT. BUFR SOUNDINGS SUGGEST DECREASING SHEAR AND INSTABILITY ENVIRONMENT WILL CONTINUE TO EVOLVE ACROSS SRN OK/WRN N TX THROUGH THE EARLY AFTN. HRRR HAS SHOWN RELATIVELY DECENT CONTINUITY THIS AM... WITH SHOWERS AND ISOLATED THUNDER LINGERING THROUGH THE AFTN AND INTO THE EVENING ACROSS SOUTH CENTRAL OK. ADJUSTED HIGH TEMPS SLIGHTLY FOR THIS AFTN... BRINGING OKC TO 67. THROUGH 10AM... ALREADY REACHED 65... AND BEGINNING TO SEE SOME BREAKS IN THE CLOUDS ACROSS NWRN OK. IF A FEW BREAKS DEVELOP OVER CENTRAL OK THIS AFTN... TEMPS COULD EASILY MOVE INTO THE UPPER 60S FOR HIGHS... SO ENJOY. JTK && .PREV DISCUSSION... /ISSUED 628 AM CDT WED AUG 19 2015/ DISCUSSION... THE 12Z AVIATION DISCUSSION FOLLOWS.... AVIATION... WIDESPREAD RA AND TSRA WILL CONTINUE ALONG...AND IN THE GENERAL VICINITY OF...A STRONG COLD FRONT ACROSS OK AND N TX. SCT SHRA WILL ALSO OCCUR WELL INTO THE COOLER AIR OVER N OK UNTIL HIGH PRESSURE FILLS IN THIS AFTERNOON/EVENING. SCATTERED AREAS OF LOW CLOUDS AND TEMPORARY LOW VISIBILITIES WILL OCCUR NEAR THE NUMEROUS TSRA. AS HIGH PRESSURE CONTINUES TO BUILD INTO OK/N TX THIS EVENING AND OVERNIGHT...THE RAIN WILL BECOME LIMITED TO THE FAR S...AND SKIES WILL BEGIN TO CLEAR IN THE N. BY SUNRISE...EXPECT VFR CONDITIONS AND LIGHT WINDS. AREAS THAT CLEAR BEFORE SUNRISE MAY DEVELOP GROUND FOG. CMS PREV DISCUSSION... /ISSUED 409 AM CDT WED AUG 19 2015/ DISCUSSION... AN UNSEASONABLY STRONG COLD FRONT EXTENDED FROM EAST-CENTRAL TO SOUTHWEST OKLAHOMA EARLY THIS MORNING...WITH AN OUTFLOW BOUNDARY EXTENDING FARTHER TO THE SOUTH...ROUGHLY FROM SHAWNEE TO WICHITA FALLS. MUCH COOLER AND DRIER AIR WAS OVER KANSAS...AND WILL SHIFT SOUTH TODAY AND TONIGHT. THE COMBINED EFFECTS OF THE COOLER/DRIER AIR...AND RAIN FALLING THROUGH IT...WILL RESULT IN TEMPERATURES THAT ARE VERY COOL FOR THIS TIME OF YEAR. RECORD LOW MAXIMUM TEMPERATURES ARE LIKELY ACROSS MUCH OF THE REGION TODAY...AND RECORD LOW MINIMUM TEMPERATURES ARE LIKELY TOMORROW MORNING. THE BALANCE OF THE VARIOUS ELEMENTS AFFECTING TEMPERATURE TODAY IS A MAJOR CHALLENGE...AND TEMPERATURE FORECASTS TODAY SHOULD BE CONSIDERED AS APPROXIMATE...ESPECIALLY HOURLY TEMPERATURES. RAIN CHANCES ARE ALSO PROBLEMATIC TODAY...AS THE EVOLUTION OF THE CURRENT MCS IS UNCLEAR. HAVE GENERALLY FORECAST POPS ABOVE THE OVERALL MODEL GUIDANCE VALUES...ON THE ASSUMPTION THAT THE MCS WILL HOLD TOGETHER AT LEAST THROUGH MID-MORNING. AFTER A DAY OF COOL DRY WEATHER...THE WARM/HUMID AIR WILL RETURN NORTH...BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS FRIDAY. A SERIES OF DISTURBANCES WILL KEEP RAIN IN THE FORECAST UNTIL EARLY NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 69 54 81 61 / 100 10 0 10 HOBART OK 70 54 84 63 / 80 10 0 20 WICHITA FALLS TX 74 57 85 66 / 100 20 0 20 GAGE OK 75 53 82 62 / 30 10 0 10 PONCA CITY OK 73 53 82 61 / 60 10 0 10 DURANT OK 82 59 82 65 / 80 50 10 20 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1151 PM EDT THU AUG 20 2015 .SYNOPSIS... A COLD FRONT WILL MOVE THROUGH THE REGION LATER THIS EVENING AND OVERNIGHT. DRIER AIR WILL MOVE IN FROM THE WEST LATER TONIGHT...WITH FAIR WEATHER AND COMFORTABLE HUMIDITY CONTINUING FOR THIS WEEKEND. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... THE WEAK SURFACE COLD FRONT JUST PASSED STATE COLLEGE WITH A WEAK WIND SHIFT AND DEWPOINTS STARTING TO FADE AWAY. THE LAST OF THE RAIN IS LEAVING THE EASTERN TIP OF SCHUYLKILL COUNTY AND WILL CONTINUE OFF TO THE EAST. AFTER A SOAKING RAIN OVER MOST OF THE AREA...IT LOOKS LIKE A GOOD SET UP FOR A FOGGY NIGHT TO DEVELOP AS SKIES CLEAR AND WINDS DROP OFF AND BECOME LIGHT. LOWS EARLY FRIDAY WILL VARY FROM THE L50S ACROSS THE NW MTNS...TO THE L-M 60S IN THE FAR SE. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... THE FRONT IS EXPECTED TO SLOW AND EVENTUALLY STALL OUT AS IT NEARS THE MID ATLC COAST...IN RESPONSE TO STRONG N. ATLC UPPER RIDGE AND UPPER/NON-TROPICAL LOW NEAR BERMUDA. THERE IS SOME CONCERN THAT THE EASTERN MOST PORTIONS OF OUR FORECAST ZONES COULD SEE LINGERING CLOUDS AND A SHOWER....BUT I USED THE HRRR TO DOWNPLAY THIS SCENARIO AS LOW PW AIR MOVES IN. SKIES SHOULD BECOME MOSTLY SUNNY ACROSS CENTRAL AND SOUTHERN PENN...WHILE PERIODS OF BKN-OVC STRATO CU WILL LIKELY FORM ACROSS THE NRN MTNS OF PENN WITH EVEN A FEW SPRINKLES POSSIBLE. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... A RELATIVELY QUIET STRETCH OF WEATHER IS IN STORE THROUGH THIS WEEKEND AND MUCH OF NEXT WEEK. PWATS WILL DROP TO -1SD FRI AND REMAIN THAT WAY THRU THE WEEKEND...WHICH WILL BE A NICE CHANGE FROM THE MUGGY AIRMASS WE SAW MUCH OF THE PAST WEEK. IN ALL...THE WEEKEND LOOKS PLEASANT WITH LOW HUMIDITY AND TEMPERATURES RUNNING A FEW DEGREES BELOW LATE-AUGUST NORMALS. THE ONLY POTENTIAL FLY IN THE OINTMENT IS A WEAK AREA OF LOW PRESSURE OFF THE MID-ATLANTIC COAST THAT COULD TRY TO PUSH A BIT OF CLOUDINESS WESTWARD INTO EASTERN PA ON SUNDAY. A WEAKENING COLD FRONT WILL CROSS THE COMMONWEALTH ON MONDAY...ACCOMPANIED BY AN OUTSIDE CHC FOR A FEW SHRA/TSRA. BEHIND THE FRONT...THE MIDDLE OF NEXT WEEK SHOULD SEE A RETURN TO LOW HUMIDITY AND SLIGHTLY BELOW NORMAL TEMPS. && .AVIATION /04Z FRIDAY THROUGH TUESDAY/... GIVEN THE COPIOUS AMOUNTS OF WIDESPREAD PRECIPITATION THIS AFTERNOON AND EVENING AND THE CLEARING SKIES AND WEAK FLOW EXPECT FOR LOW STRATOCU AND PATCHY DENSE FOG TO DEVELOP OVERNIGHT. IN THE 11U-3.9U THERE IS A LINE OF DRY AIR MOVING IN WHICH WILL LIMIT AND PREVENT FOG/LOW STRATOCU DEVELOPMENT. IPT HAS DECOUPLED WITH LIFR CIGS AND VSBYS. GIVEN THE WESTERLY FLOW EXPECT WESTERN AND CENTRAL TAF SITES TO HAVE PERIODS OF IFR FROM 06Z TO 13Z WITH MVFR TO POSSIBLY VFR IN THE INTERIM. AS THE REGION MIXES OUT AFTER SUNRISE AND DRY AIR MIXES DOWN ANY AREAS OF 1/2SM VSBY FOG WILL TEND TO MVFR BETWEEN 12Z TO 15Z BEFORE BECOMING VFR ACROSS ALL OF CENTRAL AND SOUTHERN PENN. OUTLOOK... SAT-MON...NO SIG WX EXPECTED. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LAMBERT/STEINBUGL LONG TERM...EVANEGO AVIATION...LAMBERT/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1048 PM EDT THU AUG 20 2015 .SYNOPSIS... A COLD FRONT WILL MOVE THROUGH THE REGION LATER THIS EVENING AND OVERNIGHT. DRIER AIR WILL MOVE IN FROM THE WEST LATER TONIGHT...WITH FAIR WEATHER AND COMFORTABLE HUMIDITY CONTINUING FOR THIS WEEKEND. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... THE WEAK SURFACE COLD FRONT JUST PASSED STATE COLLEGE WITH A WEAK WIND SHIFT AND DEWPOINTS STARTING TO FADE AWAY. THE LAST OF THE RAIN IS LEAVING THE EASTERN TIP OF SCHUYLKILL COUNTY AND WILL CONTINUE OFF TO THE EAST. AFTER A SOAKING RAIN OVER MOST OF THE AREA...IT LOOKS LIKE A GOOD SET UP FOR A FOGGY NIGHT TO DEVELOP AS SKIES CLEAR AND WINDS DROP OFF AND BECOME LIGHT. LOWS EARLY FRIDAY WILL VARY FROM THE L50S ACROSS THE NW MTNS...TO THE L-M 60S IN THE FAR SE. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... THE FRONT IS EXPECTED TO SLOW AND EVENTUALLY STALL OUT AS IT NEARS THE MID ATLC COAST...IN RESPONSE TO STRONG N. ATLC UPPER RIDGE AND UPPER/NON-TROPICAL LOW NEAR BERMUDA. THERE IS SOME CONCERN THAT THE EASTERN MOST PORTIONS OF OUR FORECAST ZONES COULD SEE LINGERING CLOUDS AND A SHOWER....BUT I USED THE HRRR TO DOWNPLAY THIS SCENARIO AS LOW PW AIR MOVES IN. SKIES SHOULD BECOME MOSTLY SUNNY ACROSS CENTRAL AND SOUTHERN PENN...WHILE PERIODS OF BKN-OVC STRATO CU WILL LIKELY FORM ACROSS THE NRN MTNS OF PENN WITH EVEN A FEW SPRINKLES POSSIBLE. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... A RELATIVELY QUIET STRETCH OF WEATHER IS IN STORE THROUGH THIS WEEKEND AND MUCH OF NEXT WEEK. PWATS WILL DROP TO -1SD FRI AND REMAIN THAT WAY THRU THE WEEKEND...WHICH WILL BE A NICE CHANGE FROM THE MUGGY AIRMASS WE SAW MUCH OF THE PAST WEEK. IN ALL...THE WEEKEND LOOKS PLEASANT WITH LOW HUMIDITY AND TEMPERATURES RUNNING A FEW DEGREES BELOW LATE-AUGUST NORMALS. THE ONLY POTENTIAL FLY IN THE OINTMENT IS A WEAK AREA OF LOW PRESSURE OFF THE MID-ATLANTIC COAST THAT COULD TRY TO PUSH A BIT OF CLOUDINESS WESTWARD INTO EASTERN PA ON SUNDAY. A WEAKENING COLD FRONT WILL CROSS THE COMMONWEALTH ON MONDAY...ACCOMPANIED BY AN OUTSIDE CHC FOR A FEW SHRA/TSRA. BEHIND THE FRONT...THE MIDDLE OF NEXT WEEK SHOULD SEE A RETURN TO LOW HUMIDITY AND SLIGHTLY BELOW NORMAL TEMPS. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... AS SHOWERS CONTINUE TO MOVE EASTWARD AND VACATE THE REGION...CLEARING SKIES AND WEAKENING WINDS WILL OVERTAKE THE REGION. GIVEN THE COPIOUS AMOUNTS OF WIDESPREAD PRECIPITATION THIS AFTERNOON AND EVENING AND THE CLEARING SKIES AND WEAK FLOW EXPECT FOR LOW STRATOCU AND PATCHY DENSE FOG TO DEVELOP OVERNIGHT. LNS HAS ALREADY FORMED A IFR CIGS AND GIVEN THE AMOUNT OF RAIN IT RECEIVED THIS SHOULD CONTINUE OVERNIGHT AND INTO MID MORNING. MOST SITES WILL SEE CONDITIONS TO DETERIORATE BETWEEN NOW AND 06Z AND THEN GO IFR BETWEEN 06Z TO 13Z...BEFORE IMPROVING AFTER SUNRISE AS THE REGION DECOUPLES. AREAS OF 1/2SM VSBY FOG ARE POSSIBLE...ESPECIALLY AT UNV...IPT...LNS AND MDT. THE ONLY CAVEAT TO LNS IS IF THE WINDS PERSIST. DRIER WESTERLY FLOW WILL WORK IN TOMORROW AND THEN VFR ACROSS ALL OF CENTRAL AND SOUTHERN PENN. A FEW PERIODS OF HIGH END MVFR STRATOCU CIGS POSSIBLE INVOF KBFD FRIDAY. OUTLOOK... SAT-MON...NO SIG WX EXPECTED. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LAMBERT/STEINBUGL LONG TERM...EVANEGO AVIATION...LAMBERT/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
902 PM EDT THU AUG 20 2015 .SYNOPSIS... A COLD FRONT WILL MOVE THROUGH THE REGION THIS EVENING AND OVERNIGHT. IMPROVING CONDITIONS FROM WEST TO EAST ARE EXPECTED TO BEGIN LATER TONIGHT...WITH FAIR WEATHER AND COMFORTABLE HUMIDITY CONTINUING FOR THIS WEEKEND. && .NEAR TERM /UNTIL MIDNIGHT TONIGHT/... THE BACK EDGE OF THE STEADY AND HEAVY RAIN SHIELD IS MOVING THROUGH MY EASTERN ZONES AND WILL CONTINUE OFF TO THE EAST OVER THE NEXT SEVERAL HOURS. THE HRRR HAS US PRETTY MUCH RAIN FREE BY 03Z/11PM AND THIS LOOKS REASONABLE. IT LOOKS LIKE A GOOD SET UP FOR A FOGGY NIGHT TO DEVELOP AS SKIES CLEAR AND WINDS DROP OFF AND BECOME LIGHT. LOWS EARLY FRIDAY WILL VARY FROM THE L50S ACROSS THE NW MTNS...TO THE L-M 60S IN THE FAR SE. && .SHORT TERM /MIDNIGHT THROUGH 6 PM FRIDAY/... THE FRONT IS EXPECTED TO SLOW AND EVENTUALLY STALL OUT AS IT NEARS THE MID ATLC COAST...IN RESPONSE TO STRONG N. ATLC UPPER RIDGE AND UPPER/NON-TROPICAL LOW NEAR BERMUDA. THERE IS SOME CONCERN THAT THE EASTERN MOST PORTIONS OF OUR FORECAST ZONES COULD SEE LINGERING CLOUDS AND A SHOWER EVEN AFTER MIDNIGHT....BUT I USED THE HRRR TO DOWNPLAY THIS SCENARIO AS LOW PW AIR MOVES IN. SKIES SHOULD BECOME MOSTLY SUNNY ACROSS CENTRAL AND SOUTHERN PENN...WHILE PERIODS OF BKN-OVC STRATO CU WILL LIKELY FORM ACROSS THE NRN MTNS OF PENN WITH EVEN A FEW SPRINKLES POSSIBLE. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... A RELATIVELY QUIET STRETCH OF WEATHER IS IN STORE THROUGH THIS WEEKEND AND MUCH OF NEXT WEEK. PWATS WILL DROP TO -1SD FRI AND REMAIN THAT WAY THRU THE WEEKEND...WHICH WILL BE A NICE CHANGE FROM THE MUGGY AIRMASS WE SAW MUCH OF THE PAST WEEK. IN ALL...THE WEEKEND LOOKS PLEASANT WITH LOW HUMIDITY AND TEMPERATURES RUNNING A FEW DEGREES BELOW LATE-AUGUST NORMALS. THE ONLY POTENTIAL FLY IN THE OINTMENT IS A WEAK AREA OF LOW PRESSURE OFF THE MID-ATLANTIC COAST THAT COULD TRY TO PUSH A BIT OF CLOUDINESS WESTWARD INTO EASTERN PA ON SUNDAY. A WEAKENING COLD FRONT WILL CROSS THE COMMONWEALTH ON MONDAY...ACCOMPANIED BY AN OUTSIDE CHC FOR A FEW SHRA/TSRA. BEHIND THE FRONT...THE MIDDLE OF NEXT WEEK SHOULD SEE A RETURN TO LOW HUMIDITY AND SLIGHTLY BELOW NORMAL TEMPS. && .AVIATION /01Z FRIDAY THROUGH TUESDAY/... AS SHOWERS CONTINUE TO MOVE EASTWARD AND VACATE THE REGION...CLEARING SKIES AND WEAKENING WINDS WILL OVERTAKE THE REGION. GIVEN THE COPIOUS AMOUNTS OF WIDESPREAD PRECIPITATION THIS AFTERNOON AND EVENING AND THE CLEARING SKIES AND WEAK FLOW EXPECT FOR LOW STRATOCU AND PATCHY DENSE FOG TO DEVELOP OVERNIGHT. LNS HAS ALREADY FORMED A IFR CIGS AND GIVEN THE AMOUNT OF RAIN IT RECEIVED THIS SHOULD CONTINUE OVERNIGHT AND INTO MID MORNING. MOST SITES WILL SEE CONDITIONS TO DETERIORATE BETWEEN NOW AND 06Z AND THEN GO IFR BETWEEN 06Z TO 13Z...BEFORE IMPROVING AFTER SUNRISE AS THE REGION DECOUPLES. AREAS OF 1/2SM VSBY FOG ARE POSSIBLE...ESPECIALLY AT UNV...IPT...LNS AND MDT. THE ONLY CAVEAT TO LNS IS IF THE WINDS PERSIST. DRIER WESTERLY FLOW WILL WORK IN TOMORROW AND THEN VFR ACROSS ALL OF CENTRAL AND SOUTHERN PENN. A FEW PERIODS OF HIGH END MVFR STRATOCU CIGS POSSIBLE INVOF KBFD FRIDAY. OUTLOOK... SAT-MON...NO SIG WX EXPECTED. && .CTP WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR PAZ057>059- 063>066. && $$ SYNOPSIS...LA CORTE/LAMBERT NEAR TERM...LA CORTE/LAMBERT SHORT TERM...LAMBERT/STEINBUGL LONG TERM...EVANEGO AVIATION...CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
802 PM EDT THU AUG 20 2015 .SYNOPSIS... A COLD FRONT WILL MOVE THROUGH THE REGION THIS EVENING AND OVERNIGHT. IMPROVING CONDITIONS FROM WEST TO EAST ARE EXPECTED TO BEGIN LATER TONIGHT...WITH FAIR WEATHER AND COMFORTABLE HUMIDITY CONTINUING FOR THIS WEEKEND. && .NEAR TERM /UNTIL MIDNIGHT TONIGHT/... THE BACK EDGE OF THE STEADY AND HEAVY RAIN SHIELD IS MOVING THROUGH MY EASTERN ZONES AND WILL CONTINUE OFF TO THE EAST OVER THE NEXT SEVERAL HOURS. THE HRRR HAS US PRETTY MUCH RAIN FREE BY 03Z/11PM AND THIS LOOKS REASONABLE. IT LOOKS LIKE A GOOD SET UP FOR A FOGGY NIGHT TO DEVELOP AS SKIES CLEAR AND WINDS DROP OFF AND BECOME LIGHT. LOWS EARLY FRIDAY WILL VARY FROM THE L50S ACROSS THE NW MTNS...TO THE L-M 60S IN THE FAR SE. && .SHORT TERM /MIDNIGHT THROUGH 6 PM FRIDAY/... THE FRONT IS EXPECTED TO SLOW AND EVENTUALLY STALL OUT AS IT NEARS THE MID ATLC COAST...IN RESPONSE TO STRONG N. ATLC UPPER RIDGE AND UPPER/NON-TROPICAL LOW NEAR BERMUDA. THERE IS SOME CONCERN THAT THE EASERNMOST PORTIONS OF OUR FORECAST ZONES COULD SEE LINGERING CLOUDS AND A SHOWER EVEN AFTER MIDNIGHT....BUT I USED THE HRRR TO DOWNPLAY THIS SCENARIO AS LOW PW AIR MOVES IN. SKIES SHOULD BECOME MOSTLY SUNNY ACROSS CENTRAL AND SOUTHERN PENN...WHILE PERIODS OF BKN-OVC STRATO CU WILL LIKELY FORM ACROSS THE NRN MTNS OF PENN WITH EVEN A FEW SPRINKLES POSSIBLE. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... A RELATIVELY QUIET STRETCH OF WEATHER IS IN STORE THROUGH THIS WEEKEND AND MUCH OF NEXT WEEK. PWATS WILL DROP TO -1SD FRI AND REMAIN THAT WAY THRU THE WEEKEND...WHICH WILL BE A NICE CHANGE FROM THE MUGGY AIRMASS WE SAW MUCH OF THE PAST WEEK. IN ALL...THE WEEKEND LOOKS PLEASANT WITH LOW HUMIDITY AND TEMPERATURES RUNNING A FEW DEGREES BELOW LATE-AUGUST NORMALS. THE ONLY POTENTIAL FLY IN THE OINTMENT IS A WEAK AREA OF LOW PRESSURE OFF THE MID-ATLANTIC COAST THAT COULD TRY TO PUSH A BIT OF CLOUDINESS WESTWARD INTO EASTERN PA ON SUNDAY. A WEAKENING COLD FRONT WILL CROSS THE COMMONWEALTH ON MONDAY...ACCOMPANIED BY AN OUTSIDE CHC FOR A FEW SHRA/TSRA. BEHIND THE FRONT...THE MIDDLE OF NEXT WEEK SHOULD SEE A RETURN TO LOW HUMIDITY AND SLIGHTLY BELOW NORMAL TEMPS. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... MOIST SERLY FLOW ASCENDING THE HIGHER TERRAIN OF CENTRAL PA...WITH A SECONDARY FETCH OF ATLANTIC MOISTURE STREAMING INTO EASTERN PA AND THE SUSQ VALLEY WILL CONTINUE TO TRIGGER PERIODS OF HEAVY SHOWERS AND BRIEF/ISOLATED TSRA INTO THIS EVENING. WHILE CONDITIONS WILL VARY BETWEEN VFR AND IFR ACROSS THE EASTERN THIRD TO HALF OF THE STATE LATE THIS AFTERNOON AND EVENING...A SEVERAL TO 8 HOUR PERIOD OF VFR IS EXPECTED IN THE WAKE OF A COLD FRONT ACROSS THE WESTERN HALF OF THE STATE THROUGH EARLY TONIGHT. LATE TONIGHT THROUGH ABOUT 12-13Z FRIDAY...DECREASING WIND...CLEARING SKIES AND LEFTOVER MOISTURE FROM THE RAINFALL WILL LEAD TO AREAS OF 1/2SM VSBY FOG. OUTLOOK... FRI...AREAS OF 1/2SM EARLY AM FOG POSS AT ALL TAF SITES...THEN VFR ACROSS ALL OF CENTRAL AND SOUTHERN PENN. A FEW PERIODS OF HIGH END MVFR STRATOCU CIGS POSSIBLE INVOF KBFD FRIDAY. SAT-MON...NO SIG WX EXPECTED. && .CTP WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR PAZ057>059- 063>066. && $$ SYNOPSIS...LA CORTE/LAMBERT NEAR TERM...LA CORTE/LAMBERT SHORT TERM...LAMBERT/STEINBUGL LONG TERM...EVANEGO AVIATION...LAMBERT
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
519 PM EDT WED AUG 19 2015 .SYNOPSIS... A WEAK FRONT WILL APPROACH THE AREA ON THURSDAY...PRECEDED BY SHOWERS AND THUNDERSTORMS. SOME DRYING IS EXPECTED OVER THE WEEKEND. ANOTHER WEAK FRONT APPROACHES OUR AREA EARLY NEXT WEEK. && .NEAR TERM /THROUGH THURSDAY/... AS OF 510PM WED...UPDATED FORECAST TO CONCENTRATE PRECIPITATION TO EASTERN PARTS OF THE CWA PER RADAR TRENDS AND HRRR GUIDANCE. RADAR HAS HAD HEAVIEST COVERAGE OF THUNDERSTORMS MOVING EASTWARD WITH SOME RESIDUAL ACTIVITY ELSEWHERE. HEAVIER STORMS OVER EASTERN PARTS OF THE CWA AGREES WITH HIGHER CAPE ANALYSIS IN THAT AREA. RAINFALL AMOUNTS WILL CONTINUE TO BE GENEROUS...GIVEN HIGH PRECIPITABLE WATER. SHOWERS WILL BEGIN TO TAPER AFTER 3Z THIS EVENING. AS OF 230 PM WED...RADAR CONTINUES TO SHOW INCREASING COVERAGE AND EXPECT NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE AREA THROUGH THE AFTERNOON. SOME MORE STRATIFORM TYPE PRECIP WITH EMBEDDED THUNDER MAY LINGER INTO THE EVENING HOURS OVER EASTERN AREAS. SPC MESOANAL SHOWING CAPES IN THE 2000-3000J/KG RANGE OUTSIDE THE MOUNTAINS. ALSO...THE DCAPE HIGHER TODAY THAN PREVIOUS DAYS NOW HAVING INCREASED TO OVER 1000J EASTERN AREAS. HENCE...SEVERE STORM CHANCES HIGHER THIS AFTERNOON AND WE SHOULD SEE SEVERAL PULSE SEVERE STORMS. THE SEVERE THREAT WILL BE ALONG SIDE THE LOCALIZED HYDRO THREAT. IN REGARD TO THE BIG PICTURE...A VORT MAX IS FORECAST TO MOVE ACROSS THE AREA DURING THE LATE AFTERNOON AND EVENING HOURS WHICH IS THE PRIMARY TRIGGER OF THE NUMEROUS SHOWERS AND STORMS. NVA BEHIND THIS FEATURE SHOULD RESULT IN A LULL IN PRECIP COVERAGE DURING THE OVERNIGHT HOURS. MINIMUM TEMPS ARE EXPECTED TO BE ABOUT A CATEGORY ABOVE CLIMO. ON THURSDAY...A DEEP UPPER TROUGH SWINGING THROUGH THE GREAT LAKES WILL PUSH A COLD FRONT SOUTHEASTWARD AND IT IS FORECAST TO REACH THE MOUNTAINS DURING THE AFTERNOON. WITH DEEP LAYER MOISTURE STILL IN PLACE...THERE STILL SHOULD BE DECENT COVERAGE OF SHOWERS AND THUNDERSTORMS IN THE MOUNTAINS. HOWEVER EAST OF THE MOUNTAINS...WITH FLOW BECOMING MORE ZONAL/DOWNSLOPE THE COVERAGE SHOULD BE SCT. MODEL FORECAST SOUNDINGS ALSO INDICATE LESS CAPE...SO SEVERE THREAT APPEARS ON THE LOW END. MAX TEMPS WILL BE NEAR TO CLIMO. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... AS OF 200 PM EDT WEDNESDAY...THE SHORT TERM FCST PERIOD INITIALIZES THURSDAY EVENING AMIDST AN ONGOING COLD FRONTAL INTRUSION. THE UPPER PATTERN WILL BE HIGHLIGHTED BY A DEEP NEGATIVELY TILTED LONGWAVE TROF EJECTING THROUGH THE GREAT LAKES WHILE BROAD RIDGING PREVAILS OVER THE DEEP SOUTH AND EASTERN GULF. AS STATED ABOVE...A COLD FRONT WILL BE WORKING ITS WAY INTO/THROUGH THE NC HIGH TERRAIN BY THURSDAY EVENING WITH DEEP SOUTHWESTERLY FLOW PREVAILING OUT AHEAD. IN RESPONSE...EXPECTING ONGOING CONVECTION IN THE WARM SECTOR AT FCST INITIALIZATION POSSIBLY AIDED BY ENHANCED SHEARING AND VORT ADVECTION ALOFT. SHORT TERM GUIDANCE IS NOW IN BETTER AGREEMENT WITH REGARDS TO THE TRACK/DEPTH OF THE FRONTAL PASSAGE WITH BOTH THE GFS/NAM ALONG WITH THE ECMWF PUSHING THE BOUNDARY SOUTH OF THE CWFA...LIKELY WASHING OUT OVER THE LOWCOUNTRY/MIDLANDS BY MID MORNING FRIDAY. BROAD SFC HIGH PRESSURE IS FCST TO ADVECT IN FROM THE MIDWEST INTO THE OHIO VALLEY JUST BEHIND THE FRONT...BEFORE SLIDING OVER THE SOUTHERN/CENTRAL APPS LATER IN THE DAY. AS A RESULT...DRIER NORTHERLY FLOW WILL WARRANT DECREASED PRECIPITATION POTENTIAL AND PARTLY CLOUDY SKIES ACROSS MUCH OF WESTERN NC. DUE TO CLOSER PROXIMITY TO ANY REMNANT FRONTAL MOISTURE...LOCATIONS ALONG AND SOUTH OF THE I85 CORRIDOR WILL SEE SLIGHTLY HIGH PROBABILITIES AND THUS PARTLY/MOSTLY CLOUDY SKIES. NEVERTHELESS...PROFILES ARE NOT SUPPORTIVE OF ANY DEEP CONVECTION AT THIS TIME THEREFORE NOTHING MORE THAN GARDEN VARIETY SHOWERS WITH PERHAPS A FEW RUMBLES OF THUNDER ARE EXPECTED. SATURDAY IS SHAPING UP TO BE THE NICEST DAY OF THE PERIOD WITH MODELS INDICATING FURTHER DRY AIR INTRUSION AS THE ABOVE MENTIONED SURFACE RIDGE MOVES EAST OF THE APPS. MOSGUIDE AND TO SOME EXTENT EVEN THE RAW NAM INDICATES DEWPOINTS IN THE UPPER 50S ACROSS NORTHWEST NC INCREASING TO THE LOWER 60S ALONG THE I85 CORRIDOR. THUS EXPECTING MOSTLY SUNNY TO PARTLY CLOUDY SKIES AND TEMPERATURES A FEW DEGREES BELOW NORMAL ALLOWING FOR A BEAUTIFUL MID/LATE AUGUST DAY. THAT SAID...NAM GUID DOES FAVORS AT LEAST SOME CHANCE FOR LOW END DESTABILIZATION OVER THE SOUTHWEST NC MOUNTAINS AND NORTHEAST GA...THEREFORE WILL INCLUDE POPS TO ACCOUNT FOR SUCH WITH MAX HEATING ON SATURDAY. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AT 230 PM EDT WEDNESDAY...ON SUNDAY AN UPPER RIDGE WILL BE OVER THE WESTERN USA...WITH A MEAN TROUGH OVER THE EAST. THE PATTERN AMPLIFIES SLIGHTLY INTO TUESDAY AS A CLOSED UPPER LOW CROSSES SOUTH CENTRAL CANADA. THE PATTERN DEAMPLIFIES SLIGHTLY BY THURSDAY AS THE CANADIAN LOW APPROACHES THE ATLANTIC....BY WHICH TIME SOME PROGRESSION TAKES PLACE...AND THE UPPER TROUGH REACHES THE EASTERN SEABOARD...WHILE THE RIDGE UPSTREAM CROSSES THE PLAINS AND EXTENDS INTO THE GULF STATES. AT THE SURFACE...SUNDAY STARTS OUT WITH HIGH PRESSURE ALONG THE EASTERN SEABOARD...WITH A COLD FRONT UPSTREAM FORM THE GREAT LAKES TO THE SOUTHERN PLAINS. THIS FRONT REACHES THE SOUTHERN APPALACHIANS ON MONDAY...MOVING TO THE COASTAL PLAIN BY TUESDAY...WHERE IT STALLS AND REMAINS INTO WEDNESDAY. OUR AREA CAN EXPECT AN ACTIVE PATTERN AHEAD OF AND ALONG THE FRONT...WITH A DRYING TREND IN THE WAKE OF THE FRONT. AT THIS TIME...PRECIPITATION AMOUNTS ARE NOT EXPECTED TO BE EXCESSIVE AS THE FRONT DOES NOT STALL UNTIL EAST OF OUR AREA. TEMPERATURES WILL RUN NEAR NORMAL. && .AVIATION /21Z WEDNESDAY THROUGH MONDAY/... AT KCLT...LOOKS LIKE IT IS GOING TO BE ACTIVE DAY FOR CONVECTION AS RADAR BEGINNING TO SHOW QUITE A BIT OF COVERAGE. CURRENT TRENDS INDICATE THAT TEMPO TSRA WILL OCCUR FROM 19Z-23Z WITH PERHAPS SOME MORE STRATIFORM TYPE PRECIP EXTENDING INTO THE EVENING HOURS AS A VORT MAX MOVES THROUGH. IFR RESTRICTIONS CERTAINLY POSSIBLE IN THE HEAVIER CONVECTIVE CELLS. AFTER ABOUT 03Z PRECIP SHOULD END WITH CONDITIONS VFR. GUIDANCE NOT TOO EXCITED ABOUT EARLY MORNING FOG/STRATUS BUT NOT CONVICNED IT WILL NOT OCCUR...SO MENTIONED SOME LIGHT FOG WITH SCT010 CIRCA 12Z. ELSEWHERE...FAIRLY SIMILAR CONDITIONS TO KCLT WITH TEMPO TSRA AND POSSIBLE IFR RESTRICTIONS INTO THE EARLY EVENING HOURS. PRECIP SHOULD END BY 03Z. EXPECT ONLY PATCHY IFR STRATUS/FOG EARLY THURSDAY. CONFIDENCE NOT HIGH ENOUGH TO PUT INTO TAF EXCEPT AT KAVL. OUTLOOK...A COLD FRONT WILL PUSH THROUGH THE AREA LATE THURSDAY AND THURSDAY NIGHT. ASSOCIATED SHOWERS/THUNDERSTORSM ARE EXPECTED TO END THURSDAY NIGHT. LINGERING LOW LEVEL MOISTURE MAY RESULT IN RESTRICTIONS IN FOG/STRATUS EARLY FRIDAY. DRY HIGH PRESSRUE BUILDING IN FROM THE NORTH WILL LIMIT RESTRICTIONS THROUGH THE WEEKEND. CONFIDENCE TABLE... 21-03Z 03-09Z 09-15Z 15-18Z KCLT HIGH 100% HIGH 85% HIGH 100% HIGH 100% KGSP HIGH 91% HIGH 83% HIGH 100% HIGH 88% KAVL HIGH 100% HIGH 96% HIGH 96% HIGH 97% KHKY HIGH 100% HIGH 87% HIGH 86% HIGH 100% KGMU MED 75% HIGH 87% HIGH 100% HIGH 87% KAND HIGH 100% HIGH 100% HIGH 91% HIGH 81% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...JAT NEAR TERM...LG/WJM SHORT TERM...CDG LONG TERM...JAT AVIATION...LG
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1050 PM CDT THU AUG 20 2015 .AVIATION... 06Z TAF CYCLE PERUSING THE LATEST HRRR AND RAP13 MODELS...CONVECTION EXPECTED TO DEVELOP AFTER 08Z TO 10Z FRIDAY ACROSS THE OKLAHOMA PANHANDLE AND THE NORTHERN AND CENTRAL TEXAS PANHANDLE. THE CONVECTION EXPE4CTED TO MOVE EAST AND SOUTH ACROSS MUCH OF THE EASTERN PORTION OF THE PANHANDLES BY 13Z TO 15Z FRIDAY. THE GUYMON TAF SITE MOST LIKELY AFFECTED BY THIS CONVECTION LATE TONIGHT AND COULD POSSIBLY IMPACT THE AMARILLO TAF SITE AS WELL CLOSER TO 10Z TO 12Z FRIDAY. HOWEVER CONFIDENCE IS LOW ON THE AMARILLO TAF SITE AND WILL INSERT A VCTS REMARK FOR NOW LATER TONIGHT AND EARLY FRIDAY MORNING. VFR CONDITIONS SHOULD BECOME MVFR IN CEILINGS AFTER 10Z TO 12Z FRIDAY...AND THEN MAY BECOME VFR AGAIN BETWEEN 18Z FRIDAY AND 00Z SATURDAY. SOUTHEAST TO SOUTH WINDS 10 TO 20 KNOTS WILL INCREASE AND BECOME GUSTY AROUND 15 TO 20 KNOTS AFTER 14Z TO 16Z FRIDAY AND PRIOR TO 00Z SATURDAY. SCHNEIDER && .PREV DISCUSSION... /ISSUED 641 PM CDT THU AUG 20 2015/ AVIATION... 00Z TAF CYCLE AN UPPER TROUGH WILL PUSH SOUTHEAST ACROSS THE PANHANDLES LATER TONIGHT AND FRIDAY MORNING ON A NORTHWESTERLY FLOW ALOFT. CANNOT RULE OUT CONVECTION LATE TONIGHT...AFTER 07Z TO 09Z FRIDAY...MAINLY AT THE DALHART TAF SITE AND POSSIBLE EVEN THE GUYMON TAF SITE. DECIDED TO HOLD OFF FOR NOW MENTIONING IN THE 00Z TAF FORECAST PACKAGE DUE TO LOW CONFIDENCE AT THE MOMENT BUT PROBABLY WILL NEED TO BE ADDED LATER. AN CONVECTION LATE TONIGHT COULD REACH THE AMARILLO TAF SITE BY 12Z FRIDAY...BUT AGAIN...CONFIDENCE TOO LOW TO MENTION. VFR CONDITIONS WILL PREVAIL EARLY HOWEVER MVFR CEILINGS EXPECTED AT ALL THREE TAF SITES AFTER 10Z TO 12Z FRIDAY. VFR CONDITIONS MAY RETURN TO THE DALHART TAF SITE AFTER 14Z TO 16Z FRIDAY. SOUTHERLY WINDS 5 TO 15 KNOTS WILL BACK TO THE SOUTHEAST AFTER 00Z FRIDAY AND INCREASE TO AROUND 10 TO 20 KNOTS WITH SOME HIGHER GUSTS LIKELY AFTER 14Z TO 16Z FRIDAY. SCHNEIDER PREV DISCUSSION... /ISSUED 453 PM CDT THU AUG 20 2015/ DISCUSSION... EARLY THIS AFTERNOON REGIONAL SURFACE ANALYSIS SHOWED THE COLD FRONT ACROSS DEEP SOUTH TEXAS WITH CONVECTION CONFINED TO SOUTHERN PORTIONS OF THE STATE. VISIBLE SATELLITE AND SURFACE OBSERVATIONS SHOWED EXTENSIVE LOW STRATUS PERSISTING ACROSS EASTERN TEXAS BUT STRATUS HAS MOSTLY DIMINISHED FURTHER WEST. SOME CUMULUS HAS DEVELOPED ACROSS PORTIONS OF THE PANHANDLE AND BENEATH INCREASING CIRRUS WITHIN STRENGTHENING WEST-NORTHWESTERLY FLOW ALOFT. A STRENGTHENING LEE SURFACE TROUGH HAS RESULTED IN A RETURN OF SOUTHERLY SURFACE WINDS BUT LOW LEVELS REMAIN RELATIVELY DRY. EVEN WITH AT LEAST PARTIAL INSOLATION TEMPERATURES HAVE BEEN ABOUT 10 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. SHORT TERM GUIDANCE IS INSISTENT ON A NORTHWARD SURGE OF LOW LEVEL THETA-E LATER TONIGHT AS LOW LEVEL JET STRENGTHENS. WEAK PRESSURE ADVECTION ON MOISTENING 310K SURFACE RAISES CONCERN FOR ELEVATED CONVECTIVE DEVELOPMENT LATE TONIGHT AND HAVE RETAINED A BROAD AREA OF SLIGHT PRECIPITATION CHANCES AS CONFIDENCE ON SPATIAL DETAILS FOR WHERE CONVECTION WILL FORM IS LOW. COVERAGE MAY INCREASE BY AROUND DAYBREAK ACROSS THE EASTERN PORTION OF THE PANHANDLES. AT LEAST WEAK ELEVATED INSTABILITY MAY BE SUFFICIENT FOR SUB-SEVERE HAIL WITH THE MOST INTENSE STORMS BUT SEVERE THUNDERSTORMS ARE UNLIKELY. A CONTINUATION OF SOUTHERLY FLOW AND LOW LEVEL MOISTENING IS EXPECTED TOMORROW. SOME LOW CLOUDS AND SHOWERS/STORMS MAY LINGER MAINLY ACROSS THE EAST IN WARM/MOIST ADVECTION REGIME BUT AS 850 MB THERMAL GRADIENT BECOMES MORE PARALLEL TO LOW LEVEL FLOW THROUGHOUT THE DAY AND SO CONVECTION SHOULD WANE AND CLOUDS SHOULD BREAK. WEAK MID LEVEL PERTURBATIONS SEEN IN WATER VAPOR LOOP OVER THE CENTRAL ROCKIES WILL PROVIDE SUBTLE LIFT OF AN INCREASINGLY UNSTABLE ENVIRONMENT LATE IN THE AFTERNOON. DIABATIC HEATING OF MOISTENING BOUNDARY LAYER...MODERATE INSTABILITY WILL DEVELOP. ISOLATED TO SCATTERED THUNDERSTORMS SHOULD FORM NEAR THE SURFACE TROUGH ACROSS THE WESTERN PORTION OF THE PANHANDLES AND FURTHER WEST ACROSS THE HIGHER TERRAIN OF EASTERN NEW MEXICO. MODELS ARE NOT PARTICULARLY COHERENT WITH WITH HANDLING THESE SMALL SCALE FEATURES AND ALSO THE EVOLUTION OF THE LEE SURFACE TROUGH SO SPATIAL AND TEMPORAL DETAILS OF CONVECTION IS SOMEWHAT UNCERTAIN. THE PRESENCE OF MODERATE INSTABILITY AND AT LEAST MODEST STORM DEPTH SHEAR MAY SUPPORT STORM ORGANIZATION AND SUSTENANCE SUPPORTING LARGE HAIL AND DAMAGING WIND POTENTIAL INTO THE EVENING. SOME INCREASE IN COVERAGE SEEMS LIKELY BY EVENING PARTICULARLY ACROSS THE EASTERN PORTION OF THE PANHANDLES AS LOW LEVEL JET STRENGTHENS. FORECAST UNCERTAINTY GROWS ON SATURDAY AND BEYOND. A POTENT SHORTWAVE TROUGH WILL MOVE ACROSS THE ROCKIES AND INTO THE NORTHERN PLAINS SENDING A COLD FRONT SOUTHWARD. THE PRECEDING ENVIRONMENT IS NOT EXPECTED TO CHANGE MUCH AS IT WILL REMAIN MOIST WITH DIURNAL HEATING RESULTING IN MODERATE INSTABILITY. ABSENCE OF ANY RESOLVABLE DISTURBANCES IN THE FLOW AND SUBTLE LARGE SCALE MID LEVEL HEIGHT RISES JUSTIFIES A DRY FORECAST FOR SATURDAY AT THIS TIME. CHANCES INCREASE DURING THE EVENING AS LEE SURFACE LOW SHIFTS EAST AND COLD FRONT MOVES INTO THE AREA...BUT CONFIDENCE IS RELATIVELY LOW WITH HOW THIS SCENARIO WILL PLAY OUT. DEEP LAYER SHEAR WILL SUPPORT ORGANIZED STORMS AND SEVERE POTENTIAL. MADE MINOR ADJUSTMENTS TO THE TIMING OF THE FRONT BRIGING IT INTO THE NORTHERN PORTION OF THE AREA QUICKER THAN MOST GUIDANCE AND INCREASING WIND SPEEDS BEHIND IT. POST FRONTAL AIR MASS SHOULD BE RELATIVELY STABLE ON SUNDAY LIMITING POTENTIAL FOR CONVECTION. HAVE CONFINED LOW PROBABILITIES TO ROUGHLY THE SOUTHERN HALF OF THE AREA BOTH SUNDAY AND MONDAY. DRIER AND WARMER WEATHER IS EXPECTED MUCH OF NEXT WEEK AS THE LARGE SCALE PATTERN AMPLIFIES AND MEAN RIDGING BUILDS. BRB && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 11/10
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
348 PM CDT WED AUG 19 2015 .SYNOPSIS... THE MAIN STORY WITH THIS FORECAST PACKAGE WILL BE THE COOLER WEATHER AND RAIN CHANCES OVER THE NEXT 12-24 HOURS. A RETURN TO WARM CONDITIONS IS EXPECTED LATER THIS WEEK AND THROUGH THE WEEKEND WITH LOWER CHANCES FOR PRECIPITATION. && .SHORT TERM (TONIGHT THROUGH FRIDAY)... A VERY DIFFICULT FORECAST EXISTS WITH SOME DIFFERENCES BETWEEN BOTH HI-RES AND COARSE MODEL SOLUTIONS. AS IS OFTEN THE CASE...NUMERICAL WEATHER PREDICTION OFTEN STRUGGLES WITH EVENTS THAT ARE EITHER WEAKLY FORCED OR PRIMARILY DRIVEN BY MESOSCALE PHENOMENON. IN THE CASE OF TODAY...A BULK OF THE LARGE SCALE FORCING FOR ASCENT WAS DISPLACED WELL TO THE NORTH OF NORTH/CENTRAL TEXAS AND THE MAIN FOCUSING MECHANISMS FOR WHAT RAIN DID FALL THIS MORNING AND THIS AFTERNOON WERE OUTFLOW BOUNDARIES FROM PREVIOUS CONVECTION ACROSS OK AND THE TX PANHANDLE. MOST OF THE CONVECTION THIS AFTERNOON ON AREA RADARS APPEAR TO BE ALONG THE FRONT WHERE SUFFICIENT LOW LEVEL CONVERGENCE IS OCCURRING. WITH THE FRONT STARTING TO QUICKLY MOVE SOUTHWARD MOST OF THIS ACTIVITY IS SHORT LIVED AS IT IS BEING UNDERCUT BY THE SHALLOWER/COOLER AIR. FOR THE REST OF THE AFTERNOON AND TONIGHT...STILL FEEL CONFIDENT ENOUGH THAT THERE WILL BE A COUPLE OF AREAS THAT COULD SEE SOME MEASURABLE PRECIPITATION. THE FIRST WILL BE ALONG OUR SOUTHEAST ZONES NEAR THE SFC-925 MB FRONT LATER THIS AFTERNOON AND INTO TONIGHT. MOST COARSE MODELS /EXCLUDING THE NAM/ SUGGEST THAT SOME LOW LEVEL FRONTOGENESIS WILL OCCUR AND SHOULD YIELD ISOLATED TO SCATTERED CONVECTION. THE OVERALL SEVERE POTENTIAL SEEMS RELATIVELY LOW...BUT GIVEN THE UNSTABLE AIRMASS AHEAD OF THE FRONT...WOULD NOT RULE OUT A STRONG DOWNBURST OR TWO. THERE MAY BE A SMALL HAIL RISK WITH CONVECTION NEAR THE FRONT...BUT THINK THAT CONVECTION IS BECOMING UNDERCUT TOO QUICKLY BEFORE HAIL PRODUCTION CAN OCCUR. THE SECOND AREA WITH A SLIGHTLY HIGHER CHANCE FOR PRECIPITATION WILL BE ALONG AND NORTH OF THE INTERSTATE 20 CORRIDOR WHERE 850 MB FRONTOGENETIC FORCING IS BEING ADVERTISED. PER THE TTU WRF AND LATEST HRRR SOME AREAS OF ISOLATED TO WIDELY SCATTERED ACTIVITY IS EXPECTED TO DEVELOP DURING THE OVERNIGHT HOURS INTO EARLY THURSDAY MORNING. CLOSER TO SUNRISE...THIS ACTIVITY SHOULD SHIFT SOUTHWARD AS DRIER AIR WORKS ITS WAY IN FROM THE NORTH. CURRENTLY THINK THAT SOME SKIES ACROSS OUR IMMEDIATE RED RIVER ZONES MAY CLEAR ENOUGH TO ALLOW FOR SOME DECENT COOLING. WITH THE CONTINUED NORTH WINDS...THIS SHOULD ALLOW TEMPERATURES TO FALL INTO THE 60S WITH PERHAPS EVEN A FEW UPPER 50S ALONG THE RED RIVER. FOR THURSDAY AND THURSDAY NIGHT...THE HIGHEST RAIN CHANCES WILL REMAIN DOWN ALONG OUR SOUTHEASTERN ZONES WHERE THE FRONT WILL STALL AND BEGIN TO LOSE ITS BAROCLINICITY. MAX TEMPERATURES WILL DEPEND ON THE AMOUNT OF SUNSHINE THAT CAN FILTER IN TO HELP OFFSET SOME OF THE COLD AIR ADVECTION. IN GENERAL THINK THAT HIGHS WILL CLIMB INTO THE LOW TO MID 80S...EXCEPT ACROSS FAR SOUTHEASTERN ZONES WHERE UPPER 80S MAY BE POSSIBLE...ESPECIALLY IF THE FRONT STALLS FURTHER NORTH THAN CURRENT EXPECTATIONS. WITH THE ZONAL FLOW ALOFT ACROSS THE CENTRAL PLAINS...LOW LEVEL FLOW SHOULD TURN AROUND TO THE EAST AND EVENTUALLY SOUTHEAST LATE THURSDAY NIGHT INTO FRIDAY. HELD ON TO SOME LINGERING SLIGHT CHANCE POPS ACROSS EASTERN ZONES WITH THE MOIST EAST FLOW AS ADVERTISED BY THE ECMWF AND GFS. INSTABILITY APPEARS MEAGER...BUT WENT AHEAD AND MENTIONED AN ISOLATED THUNDERSTORM OR TWO IN THE WORDED FORECASTS. FOR FRIDAY...ANOTHER UPPER WAVE LOOKS TO MOVE EASTWARD OUT FROM THE INTERMOUNTAIN WEST. THERE IS SOME WEAK LARGE SCALE ASCENT AS EVIDENCED BY SOME UPPER LEVEL PV ACROSS THE NORTHERN AND NORTHEASTERN ZONES. AS A RESULT...RETAINED INHERITED SLIGHT CHANCE POPS ON FRIDAY. WITH THE RETURN TO THE SOUTH FLOW...EXPECT AN INCREASE IN LOW LEVEL MOISTURE AND AN INCREASE IN THE TEMPERATURES AS WELL. TEMPERATURES WILL CLIMB BACK TOWARDS SEASONAL NORMS ON FRIDAY...OUTSIDE ANY PRECIPITATION THAT OCCURS. && .LONG TERM (SATURDAY AND SUNDAY)... FOR SATURDAY AND SUNDAY...MAINTAINED SLIGHT CHANCES FOR PRECIPITATION ACROSS NORTHERN AND EASTERN ZONES WITH THESE AREAS REMAINING ON THE NORTHERN AND EASTERN FRINGES OF A BUILDING MID LEVEL RIDGE. HIGH TEMPERATURES SHOULD CLIMB INTO THE 90S AREA WIDE ON SATURDAY. BOTH THE GFS AND ECMWF ADVERTISE A WEAK BACKDOOR COLD FRONT SOMETIME LATE SUNDAY. THE RIDGE SHOULD GRADUALLY WEAKEN ON ITS EASTERN PERIPHERY WHICH MAY ALLOW FOR THE DEVELOPMENT OF SOME PRECIPITATION ALONG THE FRONT. AS A RESULT...HAVE INTRODUCED LOW CHANCE POPS MAINLY ALONG THE RED RIVER AND ACROSS EASTERN ZONES FOR SUNDAY AND INTO THE DAY ON MONDAY. THERE ARE SOME DISCREPANCIES BETWEEN THE GFS AND THE ECMWF IN THE LONG TERM WITH REGARDS TO HOW FAR SOUTH THIS NEXT COLD FRONT WILL SWEEP SO CONFIDENCE IS NOT HIGH ENOUGH TO DEVIATE TOO FAR FROM A CONSENSUS/BLENDED FORECAST. BAIN && .AVIATION... /ISSUED 100 PM CDT WED AUG 19 2015/ /18Z TAFS/ COLD FRONT IS MOVING THROUGH THE DFW AREA NOW AND NORTH WINDS ARE EXPECTED AT ALL THE DFW METROPLEX TAF SITES BY 19Z. SUSTAINED WIND SPEEDS OF 12-16KTS WITH WIND GUSTS IN THE 15-25KT RANGE WILL OCCUR BEHIND THE FRONT THROUGH THE AFTERNOON HOURS. THERE IS A SMALL CHANCE FOR ISOLATED SHOWERS OR STORMS AS THE FRONT MOVES THROUGH AND WILL CARRY A VCSH FOR TWO HOURS AFTER THE FRONT PASSES. THEN A FEW DRY HOURS ARE EXPECTED WITH ANOTHER CHANCE FOR SHOWERS OVERNIGHT. VFR CONDITIONS ARE EXPECTED TO PREVAIL BUT IT IS POSSIBLE MVFR CIGS MAY DEVELOP OVERNIGHT OVER THE SHALLOW SURFACE COLD FRONT. THE FRONT IS EXPECTED TO REACH KACT AROUND 22-23Z BUT A WIND SHIFT TO THE NORTH MAY OCCUR BEFORE THE TRUE FRONT ARRIVES. WILL CARRY VCTS THROUGH THE AFTERNOON HOURS FOR CONVECTION DEVELOPING AHEAD OF THE FRONT...AND THEN CONTINUE VCTS FOR ABOUT 2 HOURS AFTER THE FRONT PASSES. ADDITIONAL SHOWERS ARE EXPECTED OVERNIGHT ALONG WITH THE DEVELOPMENT OF MVFR CIGS. JLDUNN && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 67 84 73 93 77 / 40 20 10 20 10 WACO, TX 69 83 74 94 76 / 30 30 20 10 5 PARIS, TX 63 79 64 89 73 / 40 20 20 30 30 DENTON, TX 63 82 69 93 76 / 40 10 10 20 20 MCKINNEY, TX 64 81 69 92 76 / 40 20 10 30 20 DALLAS, TX 68 85 74 94 78 / 40 20 10 20 10 TERRELL, TX 66 81 72 92 76 / 40 30 20 20 10 CORSICANA, TX 68 82 73 93 76 / 30 30 20 20 10 TEMPLE, TX 70 86 73 94 75 / 40 30 20 10 5 MINERAL WELLS, TX 64 83 70 94 75 / 40 20 10 20 10 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 82/15
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
944 PM CDT THU AUG 20 2015 .UPDATE...MID LEVEL CLOUD DECK FORMING OVER ERN NE AND WRN IA WILL TREK ACROSS SRN WI FRI AM AND POSSIBLY LINGER INTO THE AFTERNOON OVER ERN WI. CLOUDS ARE ASSOCIATED WITH 850-700 MB WARM ADVECTION AND FRONTOGENESIS. PARTLY CLOUDY SKIES EXPECTED FOR THE AFTERNOON WITH SOME FAIR WX CUMULUS. HIGH TEMPS NEAR 80F...BECOMING COOLER NEAR THE LAKE VIA A LAKE BREEZE. && .AVIATION/06Z TAFS/...MAINLY VFR CONDITIONS FOR EARLY FRI AM THROUGH FRI NT. A RIDGE OF HIGH PRESSURE WILL MOVE ACROSS SRN WI EARLY FRI AM WITH SOME FOG IN LOW LYING AREAS BUT TAF SITES SHOULD REMAIN VFR. A MID LEVEL DECK OF BROKEN CLOUD COVER IS EXPECTED FRI AM AND POSSIBLY LINGER INTO THE AFTERNOON OVER ERN WI BEFORE GIVING WAY TO FAIR WX CUMULUS AROUND 5-6 KFT. && .PREV DISCUSSION... /ISSUED 248 PM CDT THU AUG 20 2015/ TONIGHT AND FRIDAY... FORECAST CONFIDENCE...HIGH CLOUDS WILL SLOWLY CLEAR OUT DURING THE EVENING AND OVERNIGHT HOURS AS A 500 MB SHORTWAVE TROUGH EVENTUALLY MAKES ITS WAY OFF TO THE NORTH AND EAST. NAM AND RAP BUFKIT SOUNDINGS INDICATE A FAIRLY DRY PROFILE BY 06Z TONIGHT. OVERNIGHT CLEARING...ALONG WITH CALMER WINDS...WILL LEAD TO SOME DECENT ADIABATIC COOLING. LOWS TONIGHT LOOK TO REACH PRIMARILY INTO THE LOWER TO MID 50S ACROSS SOUTHERN WISCONSIN...WITH SOME ISOLATED LOCATIONS REACHING INTO THE UPPER 40S. ONCE THE SHORTWAVE MOVES OFF TO THE EAST...A MORE ZONAL MID-LEVEL FLOW WILL MOVE INTO THE REGION...KEEPING CONDITIONS QUIET. A PUSH OF FEW TO SCATTERED LOW-LEVEL CLOUDS COULD APPEAR BY SUNRISE FRIDAY AS A SURGE OF LOW-LEVEL MOISTURE MAKES ITS WAY INTO THE REGION. ADDITIONALLY...SOME PATCHY FOG IS POSSIBLE ALONG THE WISCONSIN RIVER VALLEY DURING THE EARLY MORNING HOURS FRIDAY. EXPECT QUIET CONDITIONS DURING THE DAY FRIDAY AS NEGATIVE VORTICITY ADVECTION AND SFC HIGH PRESSURE WILL BE IN CONTROL OVER THE REGION. SSW WINDS WILL BECOME GUSTY AGAIN DURING THE DAY FRIDAY...ALTHOUGH NOT AS STRONG AS WINDS FROM THURSDAY. FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE IS HIGH. HIGH PRESSURE WILL REMAIN ANCHORED OVER THE EASTERN GREAT LAKES...KEEPING US DRY THROUGH SATURDAY. WE SHOULD SEE SOME RADIATIVE COOLING FRIDAY NIGHT...BUT IT WILL BE TEMPERED BY SOME DECENT WINDS AND MIXING JUST ABOVE THE BOUNDARY LAYER. A TROUGH OF LOW PRESSURE AND IS ASSOCIATED COLD FRONT WILL APPROACH THE REGION ON SATURDAY...TIGHTENING UP THE PRESSURE GRADIENT ACROSS THE FORECAST AREA. LOOK FOR SOUTHERLY WINDS TO INCREASE AND BECOME QUITE GUSTY IN THE AFTERNOON. TEMPS SHOULD CLIMB INTO THE LOWER AND MID 80S. SATURDAY NIGHT AND SUNDAY...FORECAST CONFIDENCE IS MEDIUM. THE TROUGH/CDFNT TO THE WEST WILL PUSH INTO SOUTHERN WISCONSIN AFTER MIDNIGHT SATURDAY NIGHT. THE MODELS SHOW BETTER SUPPORT THROUGH A DEEP LAYER UPSTREAM...BUT IT WEAKENS AS THE SFC TROUGH MOVES IN. GIVEN THE LATE TIMING OF THE TROUGH ARRIVAL AND THE WEAKENING SUPPORT...I/LL BE SOMEWHAT CONSERVATIVE IN PRECIP CHANCES AS IT TRACKS EAST THROUGH SUNDAY MORNING. THE BEST CHANCE FOR RAIN WILL BE WEST AND NORTH OF MADISON LATE SATURDAY NIGHT INTO SUNDAY MORNING. WEAKER CHANCES ALONG THE WI/IL BORDER AND THE SOUTHEAST. THE TROUGH AND CDFNT WILL EXIT EASTERN WISCONSIN DURING THE EARLY AFTERNOON WITH COOLER AND DRIER AIR MOVING RIGHT BACK IN. MONDAY THROUGH THURSDAY...FORECAST CONFIDENCE IS HIGH. BIG CANADIAN HIGH PRESSURE BUILDS IN FOR MUCH OF NEXT WEEK. EXPECT DRY CONDITIONS WITH HIGHS IN THE 70S AND LOWS IN THE 50S. WE MIGHT SEE ANOTHER TROUGH APPROACH LATE IN THE WEEK FOR A CHANCE OF RAIN. LOTS OF MODEL UNCERTAINTY WITH THAT. AVIATION/00Z TAFS/... EXPECT VFR CIGS AND VSBYS TONIGHT AS AN AREA OF LOW PRESSURE SLOWLY MAKES ITS WAY OFF TO THE NORTH AND EAST. THE LAST OF THE LOW- TO MID- LEVEL CLOUDS WILL SLOWLY MOVE OUT BY THE EARLY EVENING. WINDS WILL WEAKEN THIS EVENING AS SFC PRESSURE GRADIENT WEAKENS AND THE BOUNDARY LAYER DECOUPLES. WINDS WILL BECOME MORE NORTHWESTERLY THIS EVENING AS THE AREA OF LOW PRESSURE MOVES OFF TO THE EAST. THERE COULD BE SOME PATCHY FOG DEVELOPING JUST WEST OF THE MSN TAF SITE IN THE WISCONSIN RIVER VALLEY...BUT NOT FORECAST TO AFFECT THE MSN AREA DIRECTLY. GUSTY WINDS WILL RETURN FROM THE SOUTH-SOUTHWEST DURING THE DAY FRIDAY. MARINE... SMALL CRAFT ADVISORY FOR ALL NEARSHORE ZONES WILL CONTINUE UNTIL 00Z TONIGHT AS WINDS WILL WEAKEN BY THAT TIME DUE TO WEAKENING SFC PRESSURE GRADIENT. WINDS WILL EVENTUALLY VEER FROM THE WEST THIS EVENING TO A MORE NORTHWESTERLY DIRECTION. NEARSHORE WINDS WILL ABATE TONIGHT...BUT EXPECT GUSTY SSW WINDS TO RETURN DURING THE DAY FRIDAY...ALTHOUGH NOT EXPECTED TO REACH SMALL CRAFT ADVISORY CRITERIA. BEACHES... BREEZY WESTERLY WINDS WILL PERSIST UNTIL EARLY EVENING. WIND SPEEDS WILL MOSTLY BE BETWEEN 15 TO 25 MPH. SWIM RISK WILL BE LOW DUE TO MORE OF AN OFFSHORE WIND EXPECTED. GUSTY SOUTH-SOUTHWEST WINDS ARE EXPECTED TO RETURN DURING THE DAY FRIDAY. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...GEHRING TONIGHT/FRIDAY AND AVIATION/MARINE...JTS FRIDAY NIGHT THROUGH THURSDAY...DAVIS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1237 PM CDT WED AUG 19 2015 UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE .SHORT TERM...TODAY...TONIGHT...AND THURSDAY ISSUED AT 305 AM CDT WED AUG 19 2015 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR ANALYSIS SHOW OCCLUDED LOW PRESSURE SPINNING OVER SOUTHERN MINNESOTA AND A COLD FRONT ARCING SOUTHWARD OVER EASTERN IOWA AND CENTRAL MISSOURI. A PRE- FRONTAL TROUGH IN COMBINATION WITH A SHORTWAVE IS PUSHING A BROKEN BAND OF SHOWERS NORTHEAST OVER NORTH-CENTRAL AND FAR NORTHEAST WI EARLY THIS MORNING. THESE SHOWERS SHOULD DEPART BY 12Z. ADDITIONAL LIGHT SHOWERS ARE OCCURRING ALONG THE COLD FRONT...WHICH WILL BE REACHING CENTRAL WI BY 12Z. AS LOW PRESSURE AND COLD FRONT MOVE NORTHEAST...PRECIP TRENDS ARE THE MAIN FORECAST CONCERNS. TODAY...OCCLUDED LOW PRESSURE WILL LIFT INTO NORTHWEST WISCONSIN EARLY THIS AFTERNOON AND INTO CENTRAL LAKE SUPERIOR BY EARLY THIS EVENING. MEANWHILE THE COLD FRONT WILL MOVE ACROSS MOST OF THE FORECAST AREA THIS MORNING EXCEPT FOR THE DOOR PENINSULA...WHICH SHOULD OCCUR EARLY THIS AFTERNOON. SCATTERED SHOWERS WILL ACCOMPANY THE COLD FRONT. BUT WITH DAYTIME HEATING...PROGGED SOUNDINGS INDICATE THAT 500-800 J/KG OF CAPE COULD DEVELOP OVER NE WI AHEAD OF THE FRONT. AS A RESULT...NOT OUT OF THE QUESTION THAT A FEW THUNDERSTORMS COULD POP UP BY LATE IN THE MORNING ALONG THE BOUNDARY. ANY THUNDERSTORMS WILL BE CAPABLE OF TRANSFERRING HIGHER WINDS ALOFT TO THE SURFACE SO WILL KEEP A MENTION OF GUSTY WINDS WITH ANY THUNDERSTORMS IN THE HWO. BEHIND THE FRONT...SOUTHWEST WINDS WILL BECOME BREEZY IN THE AFTERNOON WITH SOME GUSTS TO 35 MPH POSSIBLE. WRAP AROUND SHOWERS COULD ALSO MOVE INTO CENTRAL AND NORTH-CENTRAL WI BY MID TO LATE AFTERNOON. HIGHS RANGING FROM THE MID 60S WEST TO MID 70S EAST. TONIGHT...THE UPPER TROUGH MOVES OVERHEAD AS THE SHORTWAVE IN THE BASE OF THE TROUGH LIFTS NORTHWARD OVER EASTERN WISCONSIN. DEEPER MOISTURE WILL ACCOMPANY THE TROUGH...WITH MOISTURE EXTENDING UPWARDS OF 700MB OVERNIGHT. ANY BREAKS IN THE CLOUDS OVER EASTERN WISCONSIN AT THE START OF THE NIGHT WILL THEREFORE LIKELY FILL IN AS THE EVENING PROGRESSES AND WILL SPREAD A SLIGHT CHANCE OF RAIN ALL THE WAY TO THE LAKESHORE. THE MORE PERSISTENT RAINS SHOULD FALL OVER NORTH-CENTRAL WI WHERE A SURFACE TROUGH WILL MOVE THROUGH. LOWS MAINLY IN THE 50S. THURSDAY...THE UPPER TROUGH WILL CONTINUE TO BE OVERHEAD DURING THE MORNING....WHICH SHOULD LEAD TO SCATTERED SHOWERS AND SPOTTY DRIZZLE. THEN THE LIGHT PRECIP SHOULD COME TO AN END IN THE AFTERNOON AS THE TROUGH LIFTS TO THE NORTHEAST. HIGHS RANGING FROM THE LOW 60S NORTH TO LOW 70S SOUTH. .LONG TERM...THURSDAY NIGHT THROUGH TUESDAY ISSUED AT 305 AM CDT WED AUG 19 2015 THE TWO MAIN WEATHER FEATURES TO KEY ON DURING THE EXTENDED PERIOD WL BE THE MOVEMENT OF THE NEXT PROMINENT SHORTWAVE TROF/ASSOCIATED CDFNT ACROSS THE NRN TIER OF STATES THIS WEEKEND INTO EARLY NEXT WEEK AND THE BUILDING OF AN UPR RDG OVER THE HI PLAINS. THE MAIN STICKING POINT AMONG THE MODELS IS WHETHER THIS SHORTWAVE TROF WL BE PROGRESSIVE OR CLOSE OFF INTO AN UPR LOW SOMEWHERE NEAR THE GREAT LAKES. THE ANSWER TO THIS QUESTION WOULD GO A LONG WAY IN DETERMINING THE WEATHER IN OUR AREA FROM SUNDAY THRU TUE. AFTER A BRIEF WARM-UP THRU SAT...TEMPS ARE EXPECTED TO FALL BELOW NORMAL FOR THE FIRST HALF OF NEXT WEEK. THE GREAT LAKES REGION TO RESIDE ON THE NRN FRINGES OF AN AREA OF HI PRES MOVING ALONG THE OHIO RIVER VALLEY THU NGT. CLEARING SKIES...LIGHT WINDS AND AN INFLUX OF DRIER AIR SHOULD ALLOW TEMPS TO FALL INTO THE MID 40S TO MID 50S RANGE WITH THE WARMER TEMPS NEAR LAKE MI. WI TO GET ON THE BACKSIDE OF THIS RETREATING AREA OF HI PRES ON FRI AS WINDS BACK TO THE S-SE. WAA WL GRADUALLY WORK ACROSS THE AREA AS 8H TEMPS CLIMB TO AROUND +15C BY 00Z SAT. TEMPS WL RESPOND WITH READINGS TOPPING OUT MAINLY IN THE MID 70S TO AROUND 80 DEGS. QUIET AND MILDER CONDITIONS EXPECTED FOR FRI NGT AS NE WI TO SIT BETWEEN HI PRES TO OUR EAST AND DEVELOPING LOW PRES WELL TO OUR WEST. BOUNDARY LAYER WINDS ARE FCST TO INCREASE THRU THE NGT AND KEEP THE ATMOSPHERE MIXED...THEREBY PREVENTING TEMPS FROM FALLING TOO FAR. LOOK FOR MINS TO RANGE FROM THE MID 50S TO AROUND 60 DEGS NORTH...LWR 60S SOUTH. ATTENTION TO BE FOCUSED ON THE MOVEMENT OF A SHARP SHORTWAVE TROF/ATTENDANT SFC CDFNT PROGGED TO REACH THE NRN PLAINS ON SAT. THIS SYSTEM TO STILL BE TOO FAR AWAY TO IMPACT NE WI...OTHER THAN BRING A BLUSTERY AND WARM DAY TO THE REGION. MAX TEMPS WL RANGE FROM AROUND 80 DEGS NORTH/LAKESHORE...LWR 80S SOUTH. THE SHORTWAVE TROF TO PUSH EAST INTO THE UPR MS VALLEY SAT NGT... AS THE CDFNT REACHES WRN WI BY DAYBREAK. EVEN THO INSTABILITY AND FORCING ARE SOMEWHAT MARGINAL...THERE IS GOOD LIFT FROM THE CDFNT AND THE 0-6KM BULK SHEAR VALUES ARE GREATER THAN 40 KTS APPROACHING CNTRL WI LATE SAT NGT. HIGHEST POPS PLACED OVER CNTRL WI WITH A POTENTIAL FOR PARTS OF ERN WI TO STAY DRY THRU THE NGT. FCST CONFIDENCE IS A BIT BETTER NOW FOR SUNDAY AND BEYOND NOW THAT THE 00Z ECMWF HAS KEPT THIS SHORTWAVE TROF PROGRESSIVE AND NOT TRY TO CLOSE THE TROF INTO AN UPR LOW. PCPN CHCS WL CONT FOR SUNDAY AS THE UPR TROF AND CDFNT MOVE THRU THE FCST AREA. TOKEN SMALL POPS WERE LEFT IN THE FCST FOR MON AND TUE DUE TO THE UNCERTAINTY OF THE MODELS HANDLING THIS SHORTWAVE TROF CORRECTLY. IF THE NEW 12Z MODEL OUTPUTS ARE SIMILAR TO THE 00Z RUN...THEN POPS COULD BE DROPPED FOR BOTH MON AND TUE WITH MORE SUNSHINE. ONE THING THAT IS MORE CERTAIN WOULD BE THE DROP IN TEMPS BEHIND THE CDFNT FOR EARLY NEXT WEEK. THIS WOULD BE ESPECIALLY TRUE ON MON WITH MAX TEMPS IN THE UPR 60S TO THE LWR HALF OF THE 70S. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1228 PM CDT WED AUG 19 2015 OCCLUDED FRONT EXTENDED FROM LAND O LAKES TO NEAR MENOMINEE MICHIGAN EARLY THIS AFTERNOON. SCATTERED SHOWERS AND PERHAPS A FEW ISOLATED THUNDERSTORMS. THE STRONGEST STORMS WERE OVER NORTHERN MARINETTE COUNTY. THE OCCLUDED FRONT WILL CONTINUE TO PUSH TO THE NORTHEAST INTO UPPER MICHIGAN THIS AFTERNOON. MEANWHILE...UPPER LOW IS EXPECTED TO MOVE EAST. A NEW WRINKLE TO THE FORECAST FOR LATER TONIGHT IS THE INCREASED CHANCES FOR SHOWERS AS AN UPPER LEVEL DISTURBANCE SWINGS AROUND THE UPPER LOW. ADDED MORE RAIN TO THE FORECAST FOR THE KATW/KGRB/KMTW 18Z TAFS FROM 06Z TO 12Z. GUSTY SOUTHWEST WINDS WILL DIMINISH AROUND 00Z...WITH GUSTY WEST WINDS TO AROUND 20 KNOTS EXPECTED AFTER 15Z THURSDAY. && .GRB WATCHES/WARNINGS/ADVISORIES... BEACH HAZARDS STATEMENT UNTIL 8 PM CDT THIS EVENING FOR WIZ022-040-050. && $$ SHORT TERM.....MPC LONG TERM......KALLAS AVIATION.......ECKBERG
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
608 AM CDT WED AUG 19 2015 UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE .SHORT TERM...TODAY...TONIGHT...AND THURSDAY ISSUED AT 305 AM CDT WED AUG 19 2015 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR ANALYSIS SHOW OCCLUDED LOW PRESSURE SPINNING OVER SOUTHERN MINNESOTA AND A COLD FRONT ARCING SOUTHWARD OVER EASTERN IOWA AND CENTRAL MISSOURI. A PRE- FRONTAL TROUGH IN COMBINATION WITH A SHORTWAVE IS PUSHING A BROKEN BAND OF SHOWERS NORTHEAST OVER NORTH-CENTRAL AND FAR NORTHEAST WI EARLY THIS MORNING. THESE SHOWERS SHOULD DEPART BY 12Z. ADDITIONAL LIGHT SHOWERS ARE OCCURRING ALONG THE COLD FRONT...WHICH WILL BE REACHING CENTRAL WI BY 12Z. AS LOW PRESSURE AND COLD FRONT MOVE NORTHEAST...PRECIP TRENDS ARE THE MAIN FORECAST CONCERNS. TODAY...OCCLUDED LOW PRESSURE WILL LIFT INTO NORTHWEST WISCONSIN EARLY THIS AFTERNOON AND INTO CENTRAL LAKE SUPERIOR BY EARLY THIS EVENING. MEANWHILE THE COLD FRONT WILL MOVE ACROSS MOST OF THE FORECAST AREA THIS MORNING EXCEPT FOR THE DOOR PENINSULA...WHICH SHOULD OCCUR EARLY THIS AFTERNOON. SCATTERED SHOWERS WILL ACCOMPANY THE COLD FRONT. BUT WITH DAYTIME HEATING...PROGGED SOUNDINGS INDICATE THAT 500-800 J/KG OF CAPE COULD DEVELOP OVER NE WI AHEAD OF THE FRONT. AS A RESULT...NOT OUT OF THE QUESTION THAT A FEW THUNDERSTORMS COULD POP UP BY LATE IN THE MORNING ALONG THE BOUNDARY. ANY THUNDERSTORMS WILL BE CAPABLE OF TRANSFERRING HIGHER WINDS ALOFT TO THE SURFACE SO WILL KEEP A MENTION OF GUSTY WINDS WITH ANY THUNDERSTORMS IN THE HWO. BEHIND THE FRONT...SOUTHWEST WINDS WILL BECOME BREEZY IN THE AFTERNOON WITH SOME GUSTS TO 35 MPH POSSIBLE. WRAP AROUND SHOWERS COULD ALSO MOVE INTO CENTRAL AND NORTH-CENTRAL WI BY MID TO LATE AFTERNOON. HIGHS RANGING FROM THE MID 60S WEST TO MID 70S EAST. TONIGHT...THE UPPER TROUGH MOVES OVERHEAD AS THE SHORTWAVE IN THE BASE OF THE TROUGH LIFTS NORTHWARD OVER EASTERN WISCONSIN. DEEPER MOISTURE WILL ACCOMPANY THE TROUGH...WITH MOISTURE EXTENDING UPWARDS OF 700MB OVERNIGHT. ANY BREAKS IN THE CLOUDS OVER EASTERN WISCONSIN AT THE START OF THE NIGHT WILL THEREFORE LIKELY FILL IN AS THE EVENING PROGRESSES AND WILL SPREAD A SLIGHT CHANCE OF RAIN ALL THE WAY TO THE LAKESHORE. THE MORE PERSISTENT RAINS SHOULD FALL OVER NORTH-CENTRAL WI WHERE A SURFACE TROUGH WILL MOVE THROUGH. LOWS MAINLY IN THE 50S. THURSDAY...THE UPPER TROUGH WILL CONTINUE TO BE OVERHEAD DURING THE MORNING....WHICH SHOULD LEAD TO SCATTERED SHOWERS AND SPOTTY DRIZZLE. THEN THE LIGHT PRECIP SHOULD COME TO AN END IN THE AFTERNOON AS THE TROUGH LIFTS TO THE NORTHEAST. HIGHS RANGING FROM THE LOW 60S NORTH TO LOW 70S SOUTH. .LONG TERM...THURSDAY NIGHT THROUGH TUESDAY ISSUED AT 305 AM CDT WED AUG 19 2015 THE TWO MAIN WEATEHR FEATURES TO KEY ON DURING THE EXTENDED PERIOD WL BE THE MOVEMENT OF THE NEXT PROMINENT SHORTWAVE TROF/ASSOCIATED CDFNT ACROSS THE NRN TIER OF STATES THIS WEEKEND INTO EARLY NEXT WEEK AND THE BUILDING OF AN UPR RDG OVER THE HI PLAINS. THE MAIN STICKING POINT AMONG THE MODELS IS WHETHER THIS SHORTWAVE TROF WL BE PROGRESSIVE OR CLOSE OFF INTO AN UPR LOW SOMEWHERE NEAR THE GREAT LAKES. THE ANSWER TO THIS QUESTION WOULD GO A LONG WAY IN DETERMINING THE WEATEHR IN OUR AREA FROM SUNDAY THRU TUE. AFTER A BRIEF WARM-UP THRU SAT...TEMPS ARE EXPECTED TO FALL BELOW NORMAL FOR THE FIRST HALF OF NEXT WEEK. THE GREAT LAKES REGION TO RESIDE ON THE NRN FRINGES OF AN AREA OF HI PRES MOVING ALONG THE OHIO RIVER VALLEY THU NGT. CLEARING SKIES...LIGHT WINDS AND AN INFLUX OF DRIER AIR SHOULD ALLOW TEMPS TO FALL INTO THE MID 40S TO MID 50S RANGE WITH THE WARMER TEMPS NEAR LAKE MI. WI TO GET ON THE BACKSIDE OF THIS RETREATING AREA OF HI PRES ON FRI AS WINDS BACK TO THE S-SE. WAA WL GRADUALLY WORK ACROSS THE AREA AS 8H TEMPS CLIMB TO AROUND +15C BY 00Z SAT. TEMPS WL RESPOND WITH READINGS TOPPING OUT MAINLY IN THE MID 70S TO AROUND 80 DEGS. QUIET AND MILDER CONDITIONS EXPECTED FOR FRI NGT AS NE WI TO SIT BETWEEN HI PRES TO OUR EAST AND DEVELOPING LOW PRES WELL TO OUR WEST. BOUNDARY LAYER WINDS ARE FCST TO INCREASE THRU THE NGT AND KEEP THE ATMOSPHERE MIXED...THEREBY PREVENTING TEMPS FROM FALLING TOO FAR. LOOK FOR MINS TO RANGE FROM THE MID 50S TO AROUND 60 DEGS NORTH...LWR 60S SOUTH. ATTENTION TO BE FOCUSED ON THE MOVEMENT OF A SHARP SHORTWAVE TROF/ATTENDANT SFC CDFNT PROGGED TO REACH THE NRN PLAINS ON SAT. THIS SYSTEM TO STILL BE TOO FAR AWAY TO IMPACT NE WI...OTHER THAN BRING A BLUSTERY AND WARM DAY TO THE REGION. MAX TEMPS WL RANGE FROM AROUND 80 DEGS NORTH/LAKESHORE...LWR 80S SOUTH. THE SHORTWAVE TROF TO PUSH EAST INTO THE UPR MS VALLEY SAT NGT... AS THE CDFNT REACHES WRN WI BY DAYBREAK. EVEN THO INSTABILITY AND FORCING ARE SOMEWHAT MARGINAL...THERE IS GOOD LIFT FROM THE CDFNT AND THE 0-6KM BULK SHEAR VALUES ARE GREATER THAN 40 KTS APPROACHING CNTRL WI LATE SAT NGT. HIGHEST POPS PLACED OVER CNTRL WI WITH A POTENTIAL FOR PARTS OF ERN WI TO STAY DRY THRU THE NGT. FCST CONFIDENCE IS A BIT BETTER NOW FOR SUNDAY AND BEYOND NOW THAT THE 00Z ECMWF HAS KEPT THIS SHORTWAVE TROF PROGRESSIVE AND NOT TRY TO CLOSE THE TROF INTO AN UPR LOW. PCPN CHCS WL CONT FOR SUNDAY AS THE UPR TROF AND CDFNT MOVE THRU THE FCST AREA. TOKEN SMALL POPS WERE LEFT IN THE FCST FOR MON AND TUE DUE TO THE UNCERTAINTY OF THE MODELS HANDLING THIS SHORTWAVE TROF CORRECTLY. IF THE NEW 12Z MODEL OUTPUTS ARE SIMILAR TO THE 00Z RUN...THEN POPS COULD BE DROPPED FOR BOTH MON AND TUE WITH MORE SUNSHINE. ONE THING THAT IS MORE CERTAIN WOULD BE THE DROP IN TEMPS BEHIND THE CDFNT FOR EARLY NEXT WEEK. THIS WOULD BE ESPECIALLY TRUE ON MON WITH MAX TEMPS IN THE UPR 60S TO THE LWR HALF OF THE 70S. && .AVIATION...FOR 12Z TAF ISSUANCE ISSUED AT 608 AM CDT WED AUG 19 2015 SHOWERS AND A FEW THUNDERSTORMS WILL IMPACT THE TAF SITES THIS MORNING ALONG A QUICK MOVING COLD FRONT. THIS LINE OF SHOWERS COULD POSSIBLY PRODUCE STRONG GUSTY WINDS TO AROUND 35 KNOTS. BEHIND THE FRONT...A TIGHT PRESSURE GRADIENT WILL CAUSE GUSTY SYNOPTIC WINDS OF 25 TO 30 KNOTS DURING THE LATE MORNING AND AFTERNOON HOURS. UPPER LEVEL LOW PRESSURE WILL MOVE OVERHEAD TONIGHT. CIGS WILL QUICKLY FALL TO IFR/LIFR OVER CENTRAL AND NORTH-CENTRAL WI...BUT WILL NOT CRASH UNTIL OVERNIGHT OVER THE EAST. SCATTERED SHOWERS ARE LIKELY TONIGHT WHICH WILL TEMPORARILY DROP VSBYS TO MVFR. && .GRB WATCHES/WARNINGS/ADVISORIES... BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR WIZ022-040-050. && $$ SHORT TERM.....MPC LONG TERM......KALLAS AVIATION.......MPC
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND THURSDAY ISSUED AT 305 AM CDT WED AUG 19 2015 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR ANALYSIS SHOW OCCLUDED LOW PRESSURE SPINNING OVER SOUTHERN MINNESOTA AND A COLD FRONT ARCING SOUTHWARD OVER EASTERN IOWA AND CENTRAL MISSOURI. A PRE- FRONTAL TROUGH IN COMBINATION WITH A SHORTWAVE IS PUSHING A BROKEN BAND OF SHOWERS NORTHEAST OVER NORTH-CENTRAL AND FAR NORTHEAST WI EARLY THIS MORNING. THESE SHOWERS SHOULD DEPART BY 12Z. ADDITIONAL LIGHT SHOWERS ARE OCCURRING ALONG THE COLD FRONT...WHICH WILL BE REACHING CENTRAL WI BY 12Z. AS LOW PRESSURE AND COLD FRONT MOVE NORTHEAST...PRECIP TRENDS ARE THE MAIN FORECAST CONCERNS. TODAY...OCCLUDED LOW PRESSURE WILL LIFT INTO NORTHWEST WISCONSIN EARLY THIS AFTERNOON AND INTO CENTRAL LAKE SUPERIOR BY EARLY THIS EVENING. MEANWHILE THE COLD FRONT WILL MOVE ACROSS MOST OF THE FORECAST AREA THIS MORNING EXCEPT FOR THE DOOR PENINSULA...WHICH SHOULD OCCUR EARLY THIS AFTERNOON. SCATTERED SHOWERS WILL ACCOMPANY THE COLD FRONT. BUT WITH DAYTIME HEATING...PROGGED SOUNDINGS INDICATE THAT 500-800 J/KG OF CAPE COULD DEVELOP OVER NE WI AHEAD OF THE FRONT. AS A RESULT...NOT OUT OF THE QUESTION THAT A FEW THUNDERSTORMS COULD POP UP BY LATE IN THE MORNING ALONG THE BOUNDARY. ANY THUNDERSTORMS WILL BE CAPABLE OF TRANSFERRING HIGHER WINDS ALOFT TO THE SURFACE SO WILL KEEP A MENTION OF GUSTY WINDS WITH ANY THUNDERSTORMS IN THE HWO. BEHIND THE FRONT...SOUTHWEST WINDS WILL BECOME BREEZY IN THE AFTERNOON WITH SOME GUSTS TO 35 MPH POSSIBLE. WRAP AROUND SHOWERS COULD ALSO MOVE INTO CENTRAL AND NORTH-CENTRAL WI BY MID TO LATE AFTERNOON. HIGHS RANGING FROM THE MID 60S WEST TO MID 70S EAST. TONIGHT...THE UPPER TROUGH MOVES OVERHEAD AS THE SHORTWAVE IN THE BASE OF THE TROUGH LIFTS NORTHWARD OVER EASTERN WISCONSIN. DEEPER MOISTURE WILL ACCOMPANY THE TROUGH...WITH MOISTURE EXTENDING UPWARDS OF 700MB OVERNIGHT. ANY BREAKS IN THE CLOUDS OVER EASTERN WISCONSIN AT THE START OF THE NIGHT WILL THEREFORE LIKELY FILL IN AS THE EVENING PROGRESSES AND WILL SPREAD A SLIGHT CHANCE OF RAIN ALL THE WAY TO THE LAKESHORE. THE MORE PERSISTENT RAINS SHOULD FALL OVER NORTH-CENTRAL WI WHERE A SURFACE TROUGH WILL MOVE THROUGH. LOWS MAINLY IN THE 50S. THURSDAY...THE UPPER TROUGH WILL CONTINUE TO BE OVERHEAD DURING THE MORNING....WHICH SHOULD LEAD TO SCATTERED SHOWERS AND SPOTTY DRIZZLE. THEN THE LIGHT PRECIP SHOULD COME TO AN END IN THE AFTERNOON AS THE TROUGH LIFTS TO THE NORTHEAST. HIGHS RANGING FROM THE LOW 60S NORTH TO LOW 70S SOUTH. .LONG TERM...THURSDAY NIGHT THROUGH TUESDAY ISSUED AT 305 AM CDT WED AUG 19 2015 THE TWO MAIN WEATEHR FEATURES TO KEY ON DURING THE EXTENDED PERIOD WL BE THE MOVEMENT OF THE NEXT PROMINENT SHORTWAVE TROF/ASSOCIATED CDFNT ACROSS THE NRN TIER OF STATES THIS WEEKEND INTO EARLY NEXT WEEK AND THE BUILDING OF AN UPR RDG OVER THE HI PLAINS. THE MAIN STICKING POINT AMONG THE MODELS IS WHETHER THIS SHORTWAVE TROF WL BE PROGRESSIVE OR CLOSE OFF INTO AN UPR LOW SOMEWHERE NEAR THE GREAT LAKES. THE ANSWER TO THIS QUESTION WOULD GO A LONG WAY IN DETERMINING THE WEATEHR IN OUR AREA FROM SUNDAY THRU TUE. AFTER A BRIEF WARM-UP THRU SAT...TEMPS ARE EXPECTED TO FALL BELOW NORMAL FOR THE FIRST HALF OF NEXT WEEK. THE GREAT LAKES REGION TO RESIDE ON THE NRN FRINGES OF AN AREA OF HI PRES MOVING ALONG THE OHIO RIVER VALLEY THU NGT. CLEARING SKIES...LIGHT WINDS AND AN INFLUX OF DRIER AIR SHOULD ALLOW TEMPS TO FALL INTO THE MID 40S TO MID 50S RANGE WITH THE WARMER TEMPS NEAR LAKE MI. WI TO GET ON THE BACKSIDE OF THIS RETREATING AREA OF HI PRES ON FRI AS WINDS BACK TO THE S-SE. WAA WL GRADUALLY WORK ACROSS THE AREA AS 8H TEMPS CLIMB TO AROUND +15C BY 00Z SAT. TEMPS WL RESPOND WITH READINGS TOPPING OUT MAINLY IN THE MID 70S TO AROUND 80 DEGS. QUIET AND MILDER CONDITIONS EXPECTED FOR FRI NGT AS NE WI TO SIT BETWEEN HI PRES TO OUR EAST AND DEVELOPING LOW PRES WELL TO OUR WEST. BOUNDARY LAYER WINDS ARE FCST TO INCREASE THRU THE NGT AND KEEP THE ATMOSPHERE MIXED...THEREBY PREVENTING TEMPS FROM FALLING TOO FAR. LOOK FOR MINS TO RANGE FROM THE MID 50S TO AROUND 60 DEGS NORTH...LWR 60S SOUTH. ATTENTION TO BE FOCUSED ON THE MOVEMENT OF A SHARP SHORTWAVE TROF/ATTENDANT SFC CDFNT PROGGED TO REACH THE NRN PLAINS ON SAT. THIS SYSTEM TO STILL BE TOO FAR AWAY TO IMPACT NE WI...OTHER THAN BRING A BLUSTERY AND WARM DAY TO THE REGION. MAX TEMPS WL RANGE FROM AROUND 80 DEGS NORTH/LAKESHORE...LWR 80S SOUTH. THE SHORTWAVE TROF TO PUSH EAST INTO THE UPR MS VALLEY SAT NGT... AS THE CDFNT REACHES WRN WI BY DAYBREAK. EVEN THO INSTABILITY AND FORCING ARE SOMEWHAT MARGINAL...THERE IS GOOD LIFT FROM THE CDFNT AND THE 0-6KM BULK SHEAR VALUES ARE GREATER THAN 40 KTS APPROACHING CNTRL WI LATE SAT NGT. HIGHEST POPS PLACED OVER CNTRL WI WITH A POTENTIAL FOR PARTS OF ERN WI TO STAY DRY THRU THE NGT. FCST CONFIDENCE IS A BIT BETTER NOW FOR SUNDAY AND BEYOND NOW THAT THE 00Z ECMWF HAS KEPT THIS SHORTWAVE TROF PROGRESSIVE AND NOT TRY TO CLOSE THE TROF INTO AN UPR LOW. PCPN CHCS WL CONT FOR SUNDAY AS THE UPR TROF AND CDFNT MOVE THRU THE FCST AREA. TOKEN SMALL POPS WERE LEFT IN THE FCST FOR MON AND TUE DUE TO THE UNCERTAINTY OF THE MODELS HANDLING THIS SHORTWAVE TROF CORRECTLY. IF THE NEW 12Z MODEL OUTPUTS ARE SIMILAR TO THE 00Z RUN...THEN POPS COULD BE DROPPED FOR BOTH MON AND TUE WITH MORE SUNSHINE. ONE THING THAT IS MORE CERTAIN WOULD BE THE DROP IN TEMPS BEHIND THE CDFNT FOR EARLY NEXT WEEK. THIS WOULD BE ESPECIALLY TRUE ON MON WITH MAX TEMPS IN THE UPR 60S TO THE LWR HALF OF THE 70S. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1054 PM CDT TUE AUG 18 2015 SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE TO IMPACT THE TAF SITES DURING THE OVERNIGHT HOURS. FOR NOW THE MAIN THUNDERSTORM ACTIVITY IS EXPECTED TO BE CONFINED TO MTW WHERE AN AREA OF THUNDERSTORMS IS TRACKING NORTH. ONCE THE MAIN SHOWERS PASS LINGERING LIGHT SHOWERS AND DRIZZLE WILL REMAIN WITH MVFR/IFR CONDITIONS. THERE IS SOME POTENTIAL FOR A LINE OF SHOWERS TO REDEVELOP WITH THE COLD FRONT ON WEDNESDAY...MAINLY FROM 13Z TO 17Z AS THE LINE OF SHOWERS WILL RACE NORTHEAST. THIS LINE OF SHOWERS COULD POSSIBLY PRODUCE STRONG GUSTY WINDS TO AROUND 40 KNOTS. A TIGHT PRESSURE GRADIENT WILL CAUSE GUSTY SYNOPTIC WINDS OF 25 TO 30 KNOTS DURING THE DAY ON WEDNESDAY. && .GRB WATCHES/WARNINGS/ADVISORIES... BEACH HAZARDS STATEMENT FROM 7 AM CDT THIS MORNING THROUGH THIS EVENING FOR WIZ022-040-050. && $$ SHORT TERM.....MPC LONG TERM......KALLAS AVIATION.......KURIMSKI
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
339 AM EDT FRI AUG 21 2015 .DISCUSSION... TODAY...GPS PRECIPITABLE WATER VALUES WERE A LITTLE ABOVE 2 INCHES EARLY THIS MORNING. RECENT CLOUD TRENDS SHOW DEBRIS CLOUDS THINNING OUT SO THERE WILL BE AMPLE MORNING HEATING. HOWEVER...THE LATEST RAP ANALYSIS SHOWS 700MB TEMPS 10-11 CELSIUS...WHICH USUALLY INDICATES DEEP CONVECTIVE DEVELOPMENT WILL BE DELAYED SOME. THE AXIS OF A WEAKENING SURFACE RIDGE OVER NORTH BAHAMAS WILL PROVIDE LIGHT WEST/SOUTHWEST WINDS THIS MORNING...DELAYING THE ONSET OF EAST COAST SEA BREEZE UNTIL NOON TO EARLY AFTERNOON. THIS WILL ALLOW SOME HEAT INDEX READINGS TO REACH 100-105 BEFORE CONVECTION INITIATES. ADDITIONALLY...THIS HOT/SULTRY AIR MASS WILL ALLOW FOR A CHANCE OF STORMS ALONG THE COAST BEFORE THE SEA BREEZE PUSHES WELL INLAND. THE STRONGEST BOUNDARY INTERACTIONS WILL OCCUR OVER THE INTERIOR DURING THE LATE AFTERNOON TO EARLY EVENING. MOS POPS CAME IN 30 PERCENT RIGHT ALONG THE COAST AND ONLY 30-50 PERCENT OVER THE INTERIOR. HAVE FOLLOWED THIS DOWNWARD TREND BUT KEPT THE INTERIOR POPS AT 50 PERCENT. FREQUENT LIGHTNING STRIKES IN STRONGER STORMS ARE LIKELY MAINLY OVER THE INTERIOR. WEAK STEERING FLOW INDICATES A CONTINUED POTENTIAL FOR QUICK 2-3 INCH RAIN AMOUNTS. GFS FORECAST SOUNDINGS SHOW A LITTLE MID LEVEL DRYING DURING THE DAY SO A THREAT FOR DOWNBURST WINDS 40-50 KNOTS ARE POSSIBLE TOO. SAT-SUN...MID-LEVEL HIGH PRESSURE OVER THE GOMEX GRADUALLY WEAKENS LATE SUN/SUN NIGHT AS SHORTWAVE IMPULSES TRAVERSE THE N/NE PERIPHERY OF THIS ANTI-CYCLONE. THIS WILL ALLOW NORTHERLY WINDS TO BACK TO NORTHWESTERLY. 500 MB TEMPERATURES WILL REMAIN FAIRLY WARM AT -5C/- 6C. AT THE SURFACE HIGH PRESSURE ACROSS THE EASTERN CONUS WILL WEAKEN AND DRIFT TOWARD THE EASTERN SEABOARD/WESTERN ATLC WITH THE APPROACH OF A COLD FRONT. THE SURFACE PRESSURE GRADIENT WILL REMAIN WEAK THROUGH THIS PERIOD WITH LIGHT NORTHEASTERLY FLOW. THE EAST COAST SEA BREEZE WILL DEVELOP EACH DAY AND PUSH INLAND. GREATEST STORM CHANCES WILL FAVOR THE INTERIOR EACH AFTERNOON WITH STEERING FLOW FROM THE N/NNE. MON-THU...TROUGHING IN THE MID-LEVELS WILL GRADUALLY DEVELOP ACROSS THE EASTERN CONUS THROUGH THIS TIME AS NWRLY FLOW ALOFT BECOMES SWRLY ACROSS THE AREA. DEEP LAYER MOISTURE WILL BE LOWER THAN PREVIOUS DAYS. A WEAK SURFACE BOUNDARY WILL BECOME NEAR STATIONARY ACROSS THE DEEP SOUTH WITH WEAK HIGH PRESSURE CONTINUING OVER ECFL. OUR LIGHT ONSHORE FLOW WILL BECOME LIGHT S/SWRLY WED-THU THOUGH THE EAST COAST SEA BREEZE WILL STILL DEVELOP EACH AFTERNOON AND PUSH INLAND. NORTHERLY STORM STEERING FLOW WILL CONTINUE MON-TUE WITH LOWER CONFIDENCE WED-THU IN STORM MOTION...THOUGH IT APPEARS TO BE LIGHT/ERRATIC FOR NOW. LOWER THAN NORMAL PRECIPITATION CHANCES LIKELY MON-TUE WITH AN UPTICK AGAIN MOVING INTO/PAST MID-WEEK TOWARDS CLIMO NUMBERS. && .AVIATION...MAINLY VFR UNTIL STORMS START FIRING THIS AFTERNOON. ALL OF THE COASTAL SITES WILL HAVE A CHANCE OF STORMS FROM ABOUT 16-20Z. OUTFLOW BOUNDARY MERGERS WILL PROPAGATE STORMS TO THE INTERIOR TERMINALS WITH THE GREATEST CHANCE ABOUT 19-23Z. CANNOT PIN DOWN WHICH TERMINALS WILL BE AFFECTED BY STRONG STORMS...BUT INTERIOR SITES WILL HAVE A SLIGHT CHANCE FOR TORRENTIAL DOWNPOURS... FREQUENT LIGHTNING STRIKES AND GUSTY WINDS ABOVE 35 KNOTS. && .MARINE... TODAY-TONIGHT...WEAK PRESSURE GRADIENT TYPICAL OF THE AUGUST DOLDRUMS WILL CONTINUE SO THERE ARE NO WIND/SEA CONCERNS. WEAK STEERING TODAY SHOULD CONFINE STORM POTENTIAL TO THE MAINLAND BUT A FEW COULD AFFECT THE INTRACOASTAL...ESPECIALLY FROM THE CAPE NORTHWARD DURING THE EARLY TO MID AFTERNOON. WEEKEND...WEAK PRESSURE GRADIENT OVER THE AREA WITH A LIGHT N/NE WIND FLOW BELOW 10 KTS. GRADIENT IS SO WEAK THAT WINDS MAY BE MORE VARIABLE IN DIRECTION AT TIMES. THE ECSB WILL DEVELOP EACH AFTERNOON PUSHING INLAND WITH A SLIGHT BUMP UP IN SPEEDS NEAR THE IMMEDIATE COAST. ONLY AN ISOLD THREAT FOR SHRA/TSRA. SEA HEIGHTS AOB 3 FT. MON-TUE...THE WEAK PRESSURE GRADIENT AND LIGHT WIND FIELDS CONTINUE INTO EARLY WEEK AS A WEAK FRONTAL BOUNDARY SETTLES ACROSS THE DEEP SOUTH/SOUTHEAST U.S. DAILY SEA BREEZE FORMATION AND PUSH INLAND DURING THE AFTERNOON WILL ALSO REMAIN COMMON. SHOWER/STORM CHANCES REMAIN ISOLD. SEAS AOB 3 FT. && .PRELIMINARY POINT TEMPS/POPS... DAB 92 76 90 75 / 40 20 30 20 MCO 94 76 93 76 / 50 20 50 20 MLB 92 77 90 77 / 40 20 30 20 VRB 92 74 89 75 / 40 20 30 20 LEE 94 77 94 77 / 50 20 50 20 SFB 94 77 93 77 / 50 20 40 20 ORL 95 78 94 77 / 50 20 50 20 FPR 92 73 89 74 / 40 20 30 20 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ SHORT TERM...LASCODY LONG TERM....SEDLOCK
AREA FORECAST DISCUSSION
NWS MIAMI FL
138 AM EDT FRI AUG 21 2015 .AVIATION... VFR WILL PREVAIL OVERNIGHT. A WEAK LAND BREEZE DEVELOPING COULD ALLOW FOR SCATTERED THUNDERSTORMS TO DEVELOP ACROSS THE EAST COAST BY MID MORNING FRI THEN OVER THE INTERIOR WITH MOVEMENT TO THE GULF COAST THROUGH THE DAY. ADDED VCTS FOR ALL TERMINALS GIVEN THIS REGIME EXPECTED. ANY DIRECT TSRA IMPACTS WOULD BE BRIEF, BUT BRIEF IFR WILL BE POSSIBLE IN HEAVY RAIN. /GREGORIA && .PREV DISCUSSION... /ISSUED 758 PM EDT THU AUG 20 2015/ AVIATION... SLIGHTLY WEAKER WIND FLOW WILL BE THE ONLY CHANGE TO THE CURRENT REGIME ON FRIDAY. IN ADDITION, A WEAKER OR NO SUBSIDENCE CAP MAY LEAD TO MORE NUMEROUS STORMS, SOME OF WHICH MAY BE CLOSER TO THE EAST COAST TAF SITES. HOWEVER, WITH FOCUS STILL OVER THE INTERIOR, AND NOT A GREAT DEAL OF CONFIDENCE, WILL NOT ADD VCTS AT THIS TIME TO THE EAST COAST. A BRIEF MVFR CIG CAN OCCUR ONCE AGAIN NEAR DAWN UNDER EAST FLOW. PREV DISCUSSION... /ISSUED 747 PM EDT THU AUG 20 2015/ UPDATE... MAKING SOME MINOR ADJUSTMENTS TO THE EVENING UPDATES BASED ON LATEST TRENDS. EARLY EVENING ACTIVITY SHOULD DIMINISH BY 02Z WITH THE GRADIENT FLOW WEAKENING CONSIDERABLY SO THE CHANCES FOR ATLANTIC DEVELOPMENT LATER TONIGHT MOVING ONSHORE SEEM RATHER REMOTE AT THIS TIME. NEITHER THE HRRR NOR THE LOCALLY RUN WRF SHOW THIS OCCURRING SO AM REMOVING MENTION OF THUNDER ALL AREAS WITH THE EXCEPTION OF THE THE OFFSHORE WATERS FOR LATER TONIGHT. KOB && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 77 92 78 92 / 20 40 30 40 FORT LAUDERDALE 79 92 79 91 / 20 50 40 50 MIAMI 79 94 78 92 / 30 50 40 50 NAPLES 78 91 77 93 / 30 50 40 50 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
346 AM CDT FRI AUG 21 2015 .SHORT TERM /TODAY/... ISSUED AT 346 AM CDT FRI AUG 21 2015 MAIN FORECAST CONCERN WAS FOCUSED ON TEMPERATURES AND WINDS FOR THIS AFTERNOON...AND WITH WEAK SHORTWAVE PROVIDING SOME ISOLATED SHOWERS/STORMS THROUGH THE MID-MORNING. A FEW ELEVATED SHOWERS/STORMS HAVE DEVELOPED OVER WEST-CENTRAL TO NORTHWEST IOWA AND LOOK TO MEANDER INTO NORTH-CENTRAL IOWA THROUGH 15Z THIS MORNING. THERE IS ENOUGH FORCING AND ELEVATED INSTABILITY...ALBEIT VERY WEAK...BUT ENOUGH TO WARRANT SLIGHT/LOW CHANCE POPS OVER THE NORTH. HOWEVER WITH A A STRONG CAP IN PLACE TODAY...IT WILL LIMIT ANYTHING PAST 15Z. THE LATEST 21.07Z HRRR HAS A DECENT HANDLE ON THE CONVECTIVE TRENDS AND LEANED TOWARD ITS SOLUTION FOR POPS/WX. STRONG MIXING AND WAA DEVELOP TODAY AS PRESSURE GRADIENT TIGHTENS THIS AFTERNOON. MIXING TO AROUND 850MB PUTS HIGHS IN THE LOWER 80S AND TWEAKED MAX TEMPS UP SLIGHTLY. THE MAV/ECS HAD A GREAT HANDLE ON TEMPS TODAY AS THE MET WAS TOO COLD THROUGHOUT THE FORECAST AREA. ALSO TWEAKED UP WINDS SLIGHTLY AS WINDS ATOP THE MIXED LAYER IN THE 25-30 KNOT RANGE. .LONG TERM /TONIGHT THROUGH THURSDAY/... ISSUED AT 346 AM CDT FRI AUG 21 2015 THE LONG TERM FORECAST IS CHARACTERIZED BY VARYING TEMPERATURES AND MOSTLY DRY CONDITIONS BUT PUNCTUATED AND HEADLINED BY THE STORM SYSTEM MOVING ACROSS THE REGION ON SATURDAY AND SATURDAY NIGHT. THE DRIVER FOR THIS SYSTEM WILL COME IN THE FORM OF A MID/UPPER LEVEL TROUGH...STRONG FOR THIS SEASON...MOVING ACROSS THE NORTHERN ROCKIES ON FRIDAY NIGHT AND OVER THE DAKOTAS AND MINNESOTA ON SATURDAY AND SATURDAY NIGHT. THIS WILL BE REFLECTED AT THE SURFACE BY A STEADILY STRENGTHENING TROUGH/FRONT...INITIALLY STRETCHING DOWN THE HIGH PLAINS AND THEN SWEEPING EAST/SOUTHEAST IN RESPONSE TO THE PROGRESSION OF THE MID/UPPER TROUGH ON SATURDAY/SATURDAY NIGHT. AHEAD OF THIS SYSTEM MOST OF SATURDAY WILL BE WARM AND INCREASINGLY BREEZY ACROSS OUR FORECAST AREA AS THE SURFACE PRESSURE GRADIENT TIGHTENS UP BETWEEN THE HIGH PLAINS TROUGH AND A LARGE HIGH PRESSURE AREA DEPARTING TO THE EAST. FOR MUCH OF THE DAY THINGS WILL REMAIN QUIET...BUT BY PEAK HEATING IN THE LATE AFTERNOON/EVENING INSTABILITY WILL BE MAXIMIZED AND THE SURFACE FRONT WILL SERVE AS A MECHANISM FOR THUNDERSTORM DEVELOPMENT COINCIDENT WITH THE ARRIVAL OF STRONGER FORCING AND WIND FIELDS ALOFT GIVEN THE APPROACH OF THE MID/UPPER TROUGH. INITIAL STORMS WILL LIKELY BE ORGANIZED WITHIN THIS ENVIRONMENT PROVIDING A FAIRLY SUBSTANTIAL SEVERE WEATHER THREAT...THEN AS THE SYSTEM MOVES EAST/SOUTHEAST WITH SUNSET THE STORMS SHOULD BECOME MORE LINEAR AND GRADUALLY DIMINISH IN INTENSITY BY THE TIME THEY REACH EASTERN IOWA. FOR NOW THE PRIMARY QUESTIONS ARE WHERE THE STORMS WILL INITIALLY DEVELOP...OVER SOUTH DAKOTA/MINNESOTA/NEBRASKA OR OVER WESTERN/NORTHWESTERN IOWA...AND HOW FAR EAST/SOUTHEAST THEY WILL REMAIN SEVERE AS THEY MOVE QUICKLY ACROSS THE STATE. SPC PRODUCTS HANDLE THE THREAT WELL AND WILL BE CLOSELY MONITORED TODAY AND TOMORROW. AFTER THE FRONT AND ASSOCIATED STORMS BLOW THROUGH ON SATURDAY NIGHT WE WILL ONCE AGAIN SEE MOSTLY CLEAR...COOL...AND BREEZY WEATHER FROM SUNDAY INTO EARLY NEXT WEEK. BY MONDAY THE 500 MB PATTERN WILL FEATURE A DEEPENING GYRE OVER THE GREAT LAKES REGION...THAT BEING THE SYSTEM THAT AFFECTED US ON SATURDAY/SATURDAY NIGHT...WITH A DEVELOPING RIDGE OVER THE FOUR CORNERS REGION. INITIALLY THIS WILL PLACE IOWA BENEATH PERSISTENT NORTHWEST FLOW RESULTING IN A VERY SLOW WARMING TREND. BY MIDWEEK AS THE EASTERN GYRE DEPARTS THE WESTERN RIDGE WILL BUILD FURTHER AND APPROACH OUR AREA...BUT MOST OF THE HEAT BUBBLE SHOULD REMAIN WEST/SOUTHWEST OF IOWA THROUGH AT LEAST WEDNESDAY. THERE ARE CONSISTENT INDICATIONS THAT A SHORTWAVE WILL OVERTOP THE 500 MB RIDGE SOMETIME AROUND THURSDAY...POSSIBLY PROVIDING US WITH ANOTHER CHANCE FOR RAIN BUT MORE IMPORTANTLY SHUNTING THE RIDGE SOUTHWARD FOR A DAY OR TWO. BEYOND THIS...LOOKING TOWARD THE NEXT WEEKEND OR SO...IT REMAINS UNCERTAIN WHETHER THE LARGE RIDGE WILL BE ABLE TO BUILD UP OVER THE MIDWEST OR WILL REMAIN JUST TO OUR SOUTHWEST. THIS WILL DETERMINE WHETHER WE GET ONE LAST BLAST OF SUMMER HEAT OR NOT. && .AVIATION...21/06Z ISSUED AT 1149 PM CDT THU AUG 20 2015 VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD WITH MID CLOUDS TO MOVE IN OVERNIGHT. STILL SOME ISOLATED SHRA/TSRA POSSIBLE LATE TONIGHT INTO EARLY FRIDAY...COULD IMPACT KFOD AND KMCW. STILL HAVE LEFT OUT OF THE TAF GIVEN THE UNCERTAINTY AND WIDELY SCATTERED NATURE OF THE EXPECTED STORMS. SOUTHERLY WINDS TO PICK UP FRIDAY...AND DIMINISH AGAIN FRIDAY EVENING. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...LEE AVIATION...BEERENDS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
352 AM MDT FRI AUG 21 2015 .SHORT TERM...(TODAY THROUGH SUNDAY NIGHT) ISSUED AT 330 AM MDT FRI AUG 21 2015 FORECAST CONCERNS WILL BE THUNDERSTORM CHANCES INTO THE BEGINNING OF THE WEEKEND AND HOW COOL TO MAKE IT SATURDAY NIGHT INTO SUNDAY NIGHT. SATELLITE SHOWING AN AMPLIFIED/BLOCKY OVER THE PACIFIC. THIS TRANSITIONS TO A BROAD TROUGH/WESTERLY ALOFT OVER MOST OF THE COUNTRY. STRONG SYSTEM DIGGING INTO SOUTHWEST CANADA WITH SEVERAL SHORTWAVE TROUGHS EMBEDDED IN THE WESTERLY FLOW. AT JET LEVEL...MODELS DID WELL. AT MID LEVELS...THE GFS/CANADIAN AND THE UKMET WERE DOING A LITTLE BETTER THAN THE ECMWF. THE SREF AND ESPECIALLY THE NAM WERE NOT DOING WELL. THE GFS WAS DOING A LITTLE BETTER THAN THE ECMWF WITH THE LOW LEVEL WIND FIELD. ALL MODELS INITIALIZED WELL ON THE LOW LEVEL THERMAL FIELD DIFFICULT AND UNCERTAIN PRECIPITATION FORECAST...ESPECIALLY THROUGH THIS EVENING. CONFIDENCE IS BELOW AVERAGE FOR THE PRECIPITATION FORECAST. TODAY/TONIGHT...WILL HAVE TO KEEP AN EYE ON ANY LATE NIGHT/EARLY MORNING DEVELOPMENT NEAR THE BOUNDARY JUST TO THE NORTH OF OUR AREA. MODELS HAVE BEEN HINTING AT IT AND WILL CONTINUE TO MONITOR. FOR YESTERDAYS THUNDERSTORMS...JUST ENOUGH MOISTURE ALONG A BOUNDARY WITH A WEAK SHORTWAVE TROUGH WAS ABLE TO SPARK ISOLATED THUNDERSTORMS OVER AND NEAR THE NORTHEAST PORTION OF THE AREA. NOT TOO DIFFERENT A SETUP FOR TODAY FROM YESTERDAY. AGAIN WHAT MAKES FORECAST UNCERTAIN IS THE MOISTURE AVAILABILITY...ESPECIALLY ABOVE THE LOW LEVELS...WHERE DOES THE SURFACE TROUGH SETUP AND THE WEAK/COMPLICATED MID LEVEL FORCING INVOLVED. MODELS HAVE THE BOUNDARY PRETTY CLOSE BUT A LITTLE FURTHER WEST THAN WHAT WAS SHOWN YESTERDAY. 700 MB SHORTWAVE EJECTS INTO THE PLAINS THIS AFTERNOON AND IT LOOKS TO BE IN TWO PIECES. ONE PORTION GOES ACROSS THE NORTH AND IS THE SLOWER OF THE TWO SHORTWAVE TROUGHS. THE SECOND ONE GOES ACROSS TO OUR SOUTH AND BRUSHES THE SOUTHERN PORTION OF THE AREA. THERE IS WEAK FORCING IN BETWEEN. ALSO THE MODELS DIFFER ON HOW FAR EAST DURING THE DAY THEY MOVE THESE SHORTWAVE TROUGHS. CONVECTIVE ALLOWING MODELS ARE HAVING A DIFFICULT WITH ALL THIS. THE ARW HAS LITTLE TO NOTHING. THE HRRR AND ESPECIALLY THE NMM DEVELOP ROBUST CONVECTION OVER THE WESTERN PORTION OF THE AREA THIS AFTERNOON CLOSE TO THE SURFACE TROUGH. THE 00Z NAM DID NOT INDICATE ANYTHING BUT NOW THE 06Z NAM IS MATCHING UP WITH THE ABOVE TWO MODELS. THE 00Z ECMWF EXPLODES CONVECTION OVER THE NORTHERN PORTION OF THE AREA. ALL THIS TIME A RATHER STOUT EML LIES OVER THE AREA. AFTER LOOKING AT THIS AND COLLABORATION...PULLED THE INITIATION A LITTLE FURTHER WEST THAN BEFORE. THE PROBLEM THEN BECOMES HOW FAR EAST TO TAKE THIS ACTIVITY. THE HRRR TAKES IT FURTHER EAST WHILE THE REST OF THE OUTPUT THAT DID DEVELOP SOMETHING JUST KEEPS IT OVER THE WEST AS IT EITHER DISSIPATES THE THUNDERSTORMS OR MOVES THEM OF THE AREA TO THE NORTH OR SOUTH. SO DID LOWER POPS A LITTLE DUE TO THIS. IT DOES LOOK LIKE THE THUNDERSTORMS END BY 06Z. HOWEVER ELEVATED STORMS/REDEVELOPMENT WILL NEED TO BE LOOKED AT AGAIN TO A LOW LEVEL JET AND DECENT WARM AIR ADVECTION PATTERN ALOFT AHEAD OF ANOTHER SHORTWAVE TROUGH. FOR THIS AFTERNOON AND EVENINGS CONVECTION...IF STORMS DEVELOP...IT WILL BE POSSIBLE THAT THESE WILL BECOME SEVERE DUE TO THE INSTABILITY AND LAPSE RATES INVOLVED. NO MATTER IF STORMS DEVELOP OR NOT...BOUNDARY LAYER MOISTURE INCREASES AND AT THE VERY LEAST A LOT OF STRATUS WILL DEVELOP WITH SOME PATCHY FOG INVOLVED. PRESSURE FALLS AND GRADIENT SUPPORT NEAR BREEZY OR BREEZY CONDITIONS. GUIDANCE HAS BEEN RUNNING COOL ON MAXES HERE THE LAST FEW DAYS. THE GFS/MAV HAS BEEN DOING THE BEST AND HAVE RAISED THE MAXES SOME. SATURDAY/SATURDAY NIGHT...PATCHY FOG ENDS BY MID MORNING WITH THE STRATUS LASTING A LITTLE LONGER. THERE ARE STILL DIFFERENCES IN HOW FAST THE MODELS BRING IN THE COLD FRONT. THE NAM IS THE SLOWEST FOLLOWED BY SREF. THE GFS/ECMWF/CANADIAN ARE THE FASTEST. ROUGHLY IT LOOKS LIKE THE FRONT IS THROUGH THE NORTHWEST HALF OF THE AREA BY LATE MORNING. THE FRONT THEN LOOKS TO MOVE ACROSS THE REST OF THE AREA BY LATE AFTERNOON OR EARLY EVENING. THE CHANCE OF THUNDERSTORMS WILL BE OVER THE SOUTHEAST PORTION OF THE AREA IN ADVANCE OF THIS FRONT. CONTINUED THE LOW CHANCE POPS IN THIS AREA. FRONT AND ASSOCIATED FORCING EXIT THE AREA EARLY IN THE EVENING AND SO PRECIPITATION CUTS OFF RATHER FAST. WINDS BEHIND THE FRONT COULD GET WINDY AND THE DAY SHIFT WILL NEED TO LOOK AT RAISING THE WINDS EVEN MORE. DESPITE SIMILAR TIMING TO YESTERDAYS OUTPUT...MODELS HAVE RAISED HIGH TEMPERATURES FOR THE DAY. THE GFS...CANADIAN AND THE NAM ARE IN DECENT AGREEMENT ON THIS. IT SEEMS THAT THE COLDER AIR DOES LAG SLIGHTLY BEHIND THE FRONT. DID RAISE MAXES A LITTLE BUT THEY MAY NEED TO BE RAISED EVEN MORE IN SOUTHERN LOCATIONS. WINDS STAY UP ENOUGH TONIGHT THAT TEMPERATURES SHOULD NOT DROP LIKE A ROCK. IF THE WINDS LET UP QUICKER...GOOD RADIATIONAL CONDITIONS WOULD BE IN PLACE AND A LOWERING OF THE MINS WOULD BE NEEDED. SUNDAY/SUNDAY NIGHT...DRY PERIOD WITH POST FRONTAL COOL AIR MASS IN PLACE. NEW GUIDANCE FOR TEMPERATURES VERY SIMILAR TO WHAT WAS IN THERE FOR MAXES AND MADE ONLY SLIGHT ADJUSTMENTS. ONCE AGAIN FOR THE MINS...IF WINDS END UP BEING LESS THAN CURRENTLY PREDICTED ADDITIONAL COOLING WILL BE NEEDED. .LONG TERM...(MONDAY THROUGH THURSDAY) ISSUED AT 330 AM MDT FRI AUG 21 2015 THE EXTENDED PERIOD LOOKS TO BE MOSTLY DRY ALONG WITH NEAR TO ABOVE NORMAL TEMPERATURES FOR THE AREA AS RIDGING INFLUENCES THE FORECAST. ON MONDAY...AN UPPER LEVEL RIDGE CONTINUES TO BUILD INTO THE PLAINS FOLLOWING THE SYSTEM PREDICTED TO IMPACT THE REGION THIS WEEKEND. THE RIDGE AMPLIFIES AND MOVES EAST EARLY NEXT WEEK...WITH ITS AXIS NEARING THE PLAINS ON WEDNESDAY. DRY CONDITIONS ARE EXPECTED DURING THIS TIME FRAME. MOISTURE RETURNS TO THE AREA WEDNESDAY AND THURSDAY AS A SHORTWAVE MOVES ALONG THE PERSISTENT RIDGE. THIS DISTURBANCE LOOKS TO GENERATE SHOWER AND THUNDERSTORM CHANCES WEDNESDAY NIGHT AND THURSDAY FOR PORTIONS OF THE REGION. AFTER SUNDAYS COOL DOWN...TEMPERATURES ARE EXPECTED TO QUICKLY REBOUND IN THE EXTENDED PERIOD WITH HIGHS IN THE UPPER 80S TO LOW 90S AND LOWS IN THE UPPER 50S TO UPPER 60S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1000 PM MDT THU AUG 20 2015 FOR KGLD AND KMCK VFR CONDITIONS EXPECTED. SOUTH WINDS 7-11KTS AT TAF ISSUANCE EXPECTED TO CONTINUE THROUGH 14Z OR SO BEFORE INCREASING TO 12KT THRESHOLD AROUND 15Z. GUSTS TO 25KTS OR SO EXPECTED FROM 17Z THROUGH SUNSET. AFTER SUNSET SUSTAINED SOUTH WINDS AROUND 13KTS EXPECTED. WILL HAVE TO WATCH A SFC TROUGH/WIND SHIFT LINE THAT IS FORECAST TO EXTEND FROM NEAR KIML TO KGLD/KITR AROUND 00Z. CONVERGENCE ALONG THIS BOUNDARY AND AN UNSTABLE AIRMASS SUGGEST AT LEAST ISOLATED THUNDERSTORMS POSSIBLE. GIVEN THE LOW THREAT OF DIRECTLY IMPACTING THE TERMINAL (KGLD) WILL LEAVE OUT OF THE FORECAST FOR NOW. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...BULLER LONG TERM...JBH AVIATION...99
AREA FORECAST DISCUSSION
NWS DULUTH MN
1231 AM CDT FRI AUG 21 2015 .UPDATE... ISSUED AT 1228 AM CDT FRI AUG 21 2015 UPDATED AVIATION SECTION BELOW. UPDATE ISSUED AT 636 PM CDT THU AUG 20 2015 UPDATED AVIATION SECTION BELOW. CLOUD COVER FORECAST IS CURRENTLY ON TRACK AND EXPECT TO LOSE A LOT OF THE REMAINING CLOUD COVER BETWEEN NOW AND 02Z...SETTING US UP FOR A FAIRLY GOOD RADIATIONAL COOLING NIGHT. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 330 PM CDT THU AUG 20 2015 SHOWERS/DRIZZLE ENDING ACROSS THE ARROWHEAD EARLY THIS AFTERNOON GIVING WAY TO SUNNY AND JUST BELOW SEASONABLE TEMPERATURES ACROSS THE REGION. CLEAR SKIES AND NEAR-CALM WIND TONIGHT WITH A HIGH PRESSURE BUILDING IN WILL LEAD TO COOL OVERNIGHT LOWS. SUNNY AND WARMER ON FRIDAY WITH HIGHS NEAR 80. ON THE SYNOPTIC SCALE THE BROAD LOW PRESSURE SYSTEM THAT BROUGHT INTENSE RAINFALL TO THE REGION EARLIER THIS WEEK IS FINALLY DEPARTING TO THE NORTHEAST. BEHIND THIS SOME LOW-LEVEL RIDGING WILL BUILD IN TO THE UPPER MIDWEST AS A HIGH PRESSURE BUILDS FROM THE TENNESSEE TO OHIO RIVER VALLEY. WARM AIR ADVECTION WILL RAMP UP DUE TO WEST/SOUTHWESTERLY WINDS AT LOW LEVELS TONIGHT INTO TOMORROW. IN ADDITION...A WEAK WARM FRONT ON THE LEADING EDGE OF THE WARM AIR ADVECTION WILL MOVE ACROSS MANITOBA INTO NORTHWEST ONTARIO...WHICH MAY GRAZE THE BORDERLAND WITH SOME SHOWERS OVERNIGHT. WHILE THERE IS NOT MUCH SUPPORT FROM THE GLOBAL MODEL SUITE AS FAR AS QPF GOES...MOST MODELS INDICATE THE NECESSARY FORCING WILL BE THERE FOR A FEW SHOWERS. THE LATEST HRRR RUNS ARE ALSO SUPPORTIVE OF THIS IDEA...SO INCLUDED SOME LOW POPS UP ALONG THE INTERNATIONAL FALLS REGION. ON FRIDAY THE LOW-LEVEL RIDGING FLATTENS OUT WITH WEST- SOUTHWEST FLOW ALOFT RESULTING IN CONTINUED WARM AIR ADVECTION. FOR REFERENCE...THE 850MB TEMP FROM THIS MORNINGS 12Z SOUNDING AT INTERNATIONAL FALLS WAS 3.1C...AND THE MODEL CONSENSUS IS FOR THIS TO RISE TO ABOUT 18C BY FRIDAY AFTERNOON. TONIGHT...GRADUALLY CLEARING SKIES WITH PATCHY FOG POSSIBLE. WINDS BECOMING NEAR-CALM IN THE EVENING WHICH SHOULD ALLOW FOR FOG TO DEVELOP...ESPECIALLY IN NORTHWEST WISCONSIN WHERE THE HEAVIEST RAINFALL HAS FALLEN OVER THE PAST FEW DAYS. GUIDANCE NOT VERY SUPPORTIVE OF THE FOG IDEA WHICH IS PROBABLY DUE TO THE DRIER AIR MOVING IN FROM THE WEST...BUT WITH A WEAK RIDGE OVER THE REGION TEMPS WILL FALL RAPIDLY AND AT LEAST PATCHY RADIATION FOG SHOULD DEVELOP. LATER IN THE NIGHT...AFTER MIDNIGHT...SOME HIGH CLOUDS MAY MOVE IN ACROSS FAR NORTH-CENTRAL MINNESOTA...AND POSSIBLY A SHOWER OR TWO IN THE INTERNATIONAL FALLS REGION. FOG MAY DISSIPATE BEFORE SUNRISE IF WINDS PICK UP BY EARLY FRIDAY MORNING...THIS WILL DEPEND ON THE TIMING OF THE RIDGE AXIS BUT THINKING BY SUNRISE FOG SHOULD BE GONE EVERYWHERE EXCEPT FOR NORTHERN WISCONSIN NEAR THE UP. LOWS IN THE LOW/MID 40S TO LOW 50S. FRIDAY...MOSTLY SUNNY...WARM...AND BREEZY. WINDS OUT OF THE SOUTH AT 10 TO 15 MPH WITH GUSTS TO NEAR 25 MPH. THERE MAY BE AN ISOLATED SHOWER IN THE MORNING ACROSS THE BORDERLAND...BUT OTHERWISE DRY. HIGHS IN THE UPPER 70S TO LOW 80S. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 330 PM CDT THU AUG 20 2015 THE MAIN CONCERN FOR THE EXTENDED IS THE THREAT FOR SEVERE WEATHER SATURDAY AFTERNOON AND NIGHT. THE SOUTHERLY FLOW CONTINUES ACROSS THE FORECAST AREA FRIDAY NIGHT OUT AHEAD OF THE SYSTEM. THE NAM AND ECMWF ARE SIMILAR WITH TAKING THE CENTER ACROSS NORTHERN MN WITH THE GFS KEEPING NORTH OF THE INTERNATIONAL BORDER. BASED ON CURRENT TRENDS AND PERFORMANCE OF THE MODELS WITH THE LAST STORM...WILL GO WITH A MIXTURE OF NAM/ECMWF FOR SOLUTION. THE COLD FRONT WILL ENTER WESTERN LATE SATURDAY MORNING AND ACROSS THE TWIN PORTS LATE SATURDAY EVENING. THUNDERSTORMS WILL DEVELOP SATURDAY MORNING IN WRN MN AND MOVE EAST DURING THE DAY. SPC DAY 3 OUTLOOK INDICATES A SLIGHT RISK MAINLY EAST OF HIGHWAY 53/I-35 IN MN WITH MARGINAL RISK ACROSS MOST OF THE REST OF THE FORECAST AREA. AS INDICATED BY THE MID SHIFT...THERE WILL BE A RISK FOR SEVERE THUNDERSTORMS IN THE AFTERNOON BUT MAY BE FOCUSED FURTHER WEST IN MN. IT STILL LOOKS LIKE A MCS MAY DEVELOP LATER IN THE AFTERNOON. IT WILL BE ANOTHER HEAVY RAIN EVENT WITH PWATS IN THE 1.5 TO 2.0 INCHES EXPECTED ACROSS THE FORECAST AREA. STORM TOTAL QPF FORECAST IS FOR 1-1.5 INCHES FROM INL TO BRD WITH 0.50 TO 0.75 INCHES FURTHER EAST BY SUNDAY MORNING. SIMILAR TO THE PAST SYSTEM...MUCH COOLER AIR WILL PUSH INTO THE REGION WITH SOME SHOWERS ON SUNDAY. HIGHS WILL BE IN THE 60S INTO THE MIDDLE OF THE WEEK WITH 45-55 AT NIGHT. A SHORTWAVE WILL PASS THROUGH THE REGION ON THURSDAY BRINGING A POSSIBILITY OF A THUNDERSTORM. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1228 AM CDT FRI AUG 21 2015 SURFACE RIDGE OF HIGH PRESSURE SLIDING EAST ACROSS THE AREA OVERNIGHT...WITH SOUTHWEST RETURN FLOW SETTING UP FOR TOMORROW. MAINLY VFR CONDITIONS AT THIS TIME WITH LIGHT AND VARIABLE WINDS. FOG HAS ALREADY DEVELOPED AT KHIB...AND EXPECT THIS TO SPREAD TO ALL TERMINALS IN THE NEXT FEW HOURS. I EXPECT KHYR...KDLH AND KHIB TO BE AFFECTED WITH IFR CONDITIONS AND CEILINGS THROUGH APPROXIMATELY 12Z...WITH MVFR CONDITIONS AT KINL AND KBRD AS SOUTH WINDS SHOULD INCREASE THERE AFTER 09Z AND HELP MIX OUT THE FOG. FOG TO DISSIPATE IN THE 11-14Z TIME RANGE AND RETURN TO VFR CONDITIONS FOR THE REMAINDER OF THE TAF PERIOD. && .PRELIMINARY POINT TEMPS/POPS... DLH 62 79 55 65 / 20 40 80 30 INL 60 80 53 63 / 20 70 80 60 BRD 64 81 54 65 / 20 70 60 30 HYR 62 81 55 67 / 10 10 70 30 ASX 61 84 57 69 / 10 10 80 30 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. LS...NONE. && $$ UPDATE...LE SHORT TERM...JJM LONG TERM...STEWART AVIATION...LE
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
150 AM PDT FRI AUG 21 2015 .SYNOPSIS...HAZY CONDITIONS WILL CONTINUE OVER THE NEXT FEW DAYS DUE TO SMOKE PASSING THROUGH THE AREA FROM CALIFORNIA WILDFIRES. A WEAK PUSH OF MOISTURE WILL LEAD TO SLIGHT CHANCES FOR THUNDERSTORMS OVER MAINLY THE HIGHER TERRAIN SOUTH OF INTERSTATE 15 FRIDAY AND SATURDAY. DEEPER MOISTURE ARRIVES MONDAY AND COULD LINGER THROUGH MID WEEK WHICH WILL RESULT IN INCREASING COVERAGE OF SHOWERS AND STORMS. && .SHORT TERM...THROUGH MONDAY NIGHT. CLEAR SKIES DOMINATE THE FORECAST AREA EARLY THIS MORNING BUT THICK SMOKE CONTINUES TO BE PROBLEMATIC ACROSS THE OWENS VALLEY. I ANTICIPATE THE SMOKE WILL CONTINUE TO BE PREVAIL ACROSS THE OWENS VALLEY AGAIN TODAY...ESPECIALLY FROM BISHOP SOUTHWARD TO OLANCHA. ELSEWHERE...HAZE REMAINS POSSIBLE AS SMOKE FROM CALIFORNIA WILDFIRES DRIFTS WEST...THROUGH AFTERNOON BREEZY CONDITIONS MAY HELP MIX OUT THE HAZE AS IT DID THURSDAY...IMPROVING THE AIR QUALITY SOMEWHAT. THE BIGGEST CONCERN IN THE SHORT TERM PERIOD BESIDES THE SMOKE REVOLVES AROUND THUNDERSTORM CHANCES. MOISTURE HAS BEEN SEEPING INTO THE AREA UNDER A SOUTHERLY FLOW IN THE LOWER LEVELS OF THE ATMOSPHERE. DEWPOINTS EARLY THIS MORNING HAVE REACHED NEAR 60 DEGREES AT BULLHEAD CITY AND NEEDLES...AND MID 60S IN LAKE HAVASU. FURTHER SOUTH...THE DEWPOINT IN YUMA HAS SHOT UP TO 75F AND VAD WIND PROFILER DATA INDICATES A SOUTHERLY FLOW OF 15-20KTS IN THE LOWER 4K FEET OF THE ATMOSPHERE DRIVING THIS DEEPER MOISTURE NORTHWARD. WHILE MUCH OF THIS MOISTURE WILL MIX OUT WITH DAYTIME HEATING...THERE SHOULD STILL BE ENOUGH MOISTURE TO KICK OFF SOME ISOLATED CONVECTION ALONG THE HIGHER TERRAIN OF MOHAVE...EXTREME EASTERN SAN BERNARDINO...AND SOUTHERN CLARK COUNTIES THIS AFTERNOON AND EVENING. TROUBLE WILL BE THE LACK OF ANY SUBSTANCIAL TRIGGERING MECHANISM TO GET THINGS GOING. EARLY MORNING RUNS OF THE HRRR DO NOT PAINT A VERY PROMISING PICTURE FOR STORMS TODAY AND MOST MODEL GUIDANCE DOESNT DEVELOP ACTIVITY DESPITE THE INSTABILITY PRESENT. OPTED TO MAINTAIN THE SLIGHT CHANCE...TERRAIN ORIENTED POPS BUT CONFIDENCE IN DEVELOPMENT IS NOT REAL HIGH. SIMILAR OUTLOOK FOR SATURDAY WITH MARGINAL MOISTURE AND INSABILITY PRESENT...BUT NO REAL TRIGGER. ON SUNDAY...ANY DISCERNIBLE INSTABILITY GETS SHIFTED FURTHER EAST INTO FAR EASTERN MOHAVE COUNTY...SO KEPT POPS LIMITED TO THOSE FAR EASTERN ZONES AND CONDITIONS DRY ELSEWHERE. TEMPERATURES FRIDAY THROUGH THE WEEKEND WILL AVERAGE 3 TO 6 DEGREES ABOVE NORMAL. ON MONDAY...LEADING EDGE OF DEEPER MONSOON MOISTURE BEGINS TO LIFT INTO NORTHWEST ARIZONA AND EASTERN CALIFORNIA. BETTER MOISTURE AT THIS POINT LOOKS TO ARRIVE OVERNIGHT AND INTO TUESDAY BUT SOME ACTIVITY MAY BREAK OUT IN MOHAVE...EASTERN SAN BERNARDINO...AND THE HIGHER TERRAIN OF CLARK COUNTIES AND MAINTAINED POPS IN THESE AREAS. .LONG TERM...TUESDAY THROUGH FRIDAY. MODELS HAVE COME INTO BETTER LARGE SCALE AGREEMENT FOR MUCH OF THE PERIOD...BUT IMPORTANT DETAIL DIFFERENCES REMAIN. FOR TUESDAY...THE GFS LOOKS MUCH LIKE ITS PREVIOUS RUNS...BUT THE ECMWF DEPICTS THE FOUR CORNERS HIGH CENTER JUST A BIT FARTHER WEST...WHICH DELAYS THE MOISTURE RETURN AND SENDS HIGH TEMPERATURES ZOOMING BACK UP TO NEAR EXCESSIVE HEAT CRITERIA. WHILE THIS IS A POSSIBILITY...BELIEVE IT HAS A LOW PROBABILITY OF OCCURRENCE GIVEN MODEL TRENDS OVER THE PAST SEVERAL DAYS...AND HAVE GIVEN IT LITTLE WEIGHT IN THE FORECAST. THE GFS SOLUTION...WHICH SUGGESTS PRECIP CHANCES ROUGHLY NEAR AND EAST OF LAS VEGAS...WAS PREFERRED. FOR WEDNESDAY AND THURSDAY...MODELS HAVE COME INTO MUCH BETTER AGREEMENT WITH AMPLIFICATION OF BOTH THE NORTHERN STREAM LOW NEAR THE BRITISH COLUMBIA COAST AND THE RIDGE EXTENDING NORTH INTO SASKATCHEWAN FROM THE FOUR CORNERS HIGH. THIS LEAVES OUR CWA IN MOIST SOUTHERLY FLOW ON WEDNESDAY...TRANSITIONING INTO A SLIGHTLY DRIER SOUTHWEST FLOW ON THURSDAY AS TROUGHING IN THE EAST PACIFIC STRETCHES ALL THE WAY DOWN BELOW 30N. THERE IS DISAGREEMENT ON HOW TO EVOLVE THIS TROUGHING ON FRIDAY...BUT DECENT CONSENSUS THAT OUR SENSIBLE WEATHER WILL CHANGE LITTLE...WITH SOUTHWEST FLOW BRINGING MINIMAL PRECIP CHANCES BUT PERHAPS NOT STRONG ENOUGH TO SCOUR OUT LOW LEVEL MOISTURE...ESPECIALLY OVER MOHAVE COUNTY. && .AVIATION...FOR MCCARRAN...LIGHT SOUTHERLY DRAINAGE WINDS EXPECTED EARLY IN THE MORNING BEFORE BECOMING LIGHT AND VARIABLE SUNRISE THROUGH AROUND 17Z. A PERIOD OF SOUTHEAST WINDS OF 9-12KTS IS POSSIBLE BETWEEN 17Z AND 20Z BEFORE SOUTH-SOUTHWEST WINDS TAKE OVER IN THE AFTERNOON WITH GUSTS TO 25KTS. HAZY CONDITIONS REMAIN POSSIBLE. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...AREAS OF HAZE EXPECTED MAINLY NORTH OF INTERSTATE 40 AGAIN TODAY WITH SMOKE MOST CONCENTRATED NEAR THE SIERRA AND OWENS VALLEY. SMOKE MAY LOCALLY REDUCE VISIBILITIES TO BELOW 4 MILES. OTHERWISE...BREEZY SOUTH WINDS OF 12-18 KTS WITH GUSTS TO 25KTS EXPECTED ACROSS THE AREA IN THE AFTERNOON. SLIGHT CHANCES FOR ISOLATED THUNDERSTORMS EXIST IN THE HIGHER TERRAIN MAINLY SOUTH AND EAST OF KLAS THIS AFTERNOON. && .SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && $$ SHORT TERM...OUTLER LONG TERM...MORGAN FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
352 AM CDT FRI AUG 21 2015 .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 345 AM CDT FRI AUG 21 2015 FORECAST CHALLENGES WILL BE SEVERE THREAT SATURDAY AS WELL AS RAINFALL AMOUNTS MAINLY THIS WEEKEND AND TEMPERATURES/WIND. MODELS OVERALL IN PRETTY GOOD AGREEMENT THROUGH THE PERIOD AND WILL USE MODEL BLEND. CURRENT SHORTWAVE PROPAGATING EAST ACROSS SW MB INTO ONTARIO THIS MORNING. ASSOCIATED AREA OF SHRA/ISOLD T ON NOSE OF LOW LEVEL JET IN WARM ADVECTION ZONE. ALTHOUGH INSTABILITY AND CAPE MINIMAL A FEW LIGHTNING STRIKES OCCURRING. CURRENT HRRR WEAKENS PCPN THROUGH THE MORNING AND OUT OF THE FA BY MID MORNING. WILL MAINTAIN LOW POPS BASED ON SHORT TERM MODEL GUIDANCE. THE REMAINDER OF THIS AFTERNOON SHOULD REMAIN DRY. CONTINUED WARM ADVECTION WILL SET UP WARM FRONTAL BOUNDARY ALONG THE INTERNATIONAL BORDER BY THIS EVENING. WITH FA IN WARM SECTOR TEMPERATURES SHOULD RECOVER WELL WITH MOST AREAS ABOVE AVERAGE. TONIGHT MORE SIGNIFICANT WAVE CURRENTLY OVER BC WILL DIG INTO THE NORTHERN ROCKIES. ASSOCIATED SURFACE LOW WILL ORGANIZE OVER THE WESTERN DAKOTAS WITH SW-NE ORIENTED BOUNDARY SETTING UP LATER IN THE NIGHT. WILL CONTINUE WITH CHANCE POPS ALONG THIS BOUNDARY. TEMPERATURES WILL REMAIN MILD OVERNIGHT. SURFACE LOW WILL LIFT NE SATURDAY AS WAVE APPROACHES. AS IT DOES ASSOCIATED COLD FRONT WILL FOLLOW LOW AND BE ORIENTED CLOSE TO THE VALLEY BY PRIME HEATING. CONVECTIVE PARAMETERS FAVORABLE FOR SEVERE STORMS ALONG AND AHEAD OF THE BOUNDARY SO SEVERE POTENTIAL WILL HINGE ON JUST WHERE BOUNDARY SETS UP. DEGREE OF CLOUD COVER WILL GOVERN TEMPERATURES WITH COOLEST READINGS OVER THE FAR NW WHICH WILL BE BEHIND THE COLD FRONT. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 345 AM CDT FRI AUG 21 2015 UPPER TROUGH CLOSES OFF SATURDAY NIGHT AS IT LIFTS NE. WRAP AROUND/DEF ZONE RAIN WILL FOLLOW. AT THIS POINT MODEL GUIDANCE SUGGESTS THAT THE BEST POTENTIAL FOR RAIN WILL BE OVER THE NORTHERN 2/3RD OF THE FA. SUNDAY WILL BE WINDY AND COOLER WITH DEF ZONE PCPN BAND SHIFTING EAST ACROSS THE FA. COOLER COLUMN AND CLOUDS WILL HOLD TEMPERATURES DOWN. RAIN WILL MOVE OUT OF THE NE FA SUNDAY NIGHT. WINDS TO DIMINISH BUT WILL BE A COOL NIGHT WITH MINIMUM TEMPERATURES IN THE 40S. LONG WAVE TROUGHS WERE OFF THE WESTERN CANADIAN COAST AND THE GREAT LAKES WITH A FLAT RIDGE OVER MT. PATTERN AMPLIFIES WITH A TROUGH OVER THE EASTERN PACIFIC/WESTERN CANADA AND RIDGING INTO THE NORTHERN PLAINS BY THE END OF THE PERIOD. GFS AND ECMWF WERE IN BETTER AGREEMENT WITH TODAYS MODEL RUN THROUGH THE PERIOD. THE ECMWF WAS SLIGHTLY FASTER THAN THE GFS. THE ECMWF WAS VACILLATING AROUND A POINT WHILE THE GFS WAS TRENDING SLOWER OVER THE LAST COUPLE MODEL RUNS. NO CHANGE TO HIGH TEMPS FOR MON. HIGH TEMPS WERE DECREASED A DEGREE OR TWO FOR TUE AND WED, AND INCREASED ZERO TO FOUR DEGREES FOR THU FORM YESTERDAYS PACKAGE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1149 PM CDT THU AUG 20 2015 SCATTERED MID AND HIGH LEVEL CLOUDS MAINLY NE ND/NW MN WITH SHORT WAVE MOVING THRU MANITOBA OVERNIGHT INTO FRIDAY MORNING. SCATTERED CIRRUS IN SE ND/WCNTRL MN. SOUTH WINDS 8 TO 15 KTS WITH A FEW GUSTS AT TIMES THRU FRIDAY....PICKING UP FRI EVENING. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ SHORT TERM...VOELKER LONG TERM...HOPPES/VOELKER AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
146 AM EDT FRI AUG 21 2015 .SYNOPSIS... A COLD FRONT HAS MOVED EAST OF THE AREA WITH COOLER AND DRIER AIR SETTLING OVER THE AREA BEHIND IT. A SURFACE AREA OF HIGH PRESSURE TO OUR WEST WILL MOVE INTO THE AREA FRIDAY AND LINGER THROUGH THE WEEKEND. THE NEXT CHANCE FOR RAIN WILL BE SUNDAY NIGHT INTO MONDAY WHEN A COLD FRONT ARRIVES. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... UPPER TROUGH WILL LIFT ACROSS THE CENTRAL GREAT LAKES OVERNIGHT. THERE WILL BE SOME INCREASED LIFT OVER THE LAKE AS THE COOLER AIR ARRIVES IN THE WAKE OF THE TROUGH. THERE COULD BE A FEW SHOWERS THAT DEVELOP FROM THE ERIE AREA NORTHWARD INTO NY STATE. HOWEVER THE MAIN IMPACT WILL BE AN INCREASE OF CLOUD COVER FROM CLEVELAND TO ERIE THROUGH THE EVENING. PREVIOUS DISCUSSION... THE WATER VAPOR SATELLITE IMAGERY DISTINCTLY DEFINES THE TROUGH OVER THE UPPER LAKES AND THE DRIER AIR FILTERING INTO THE OHIO VALLEY ALOFT. AT THE SURFACE HIGH PRESSURE OVER THE PLAINS WILL SLIDE EAST OVERNIGHT AND LINGER OVER THE AIR INTO THE WEEKEND. DEW POINTS HAVE DROPPED 10-15F SINCE THIS MORNING...WHICH WILL SUPPORT NOTABLY COOLER TEMPERATURES OVERNIGHT. NCAR ENSEMBLES ALONG WITH THE RUC ARE SUGGESTING DEW POINTS INTO THE UPPER 40S OVERNIGHT...HOWEVER NOT SEEING ANY 40S UPSTREAM OR NEAR THE AREA DESPITE A FAIR AMOUNT OF AFTERNOON MIXING. WITH DEW POINTS IN THE LOW TO MID 50S...MOSTLY CLEAR SKIES...AND WINDS TAPERING OFF AFTER DARK...WILL KEEP TEMPERATURES IN THE LOW TO MID 50S OVERNIGHT. ONLY FLY IN THE OINTMENT WILL BE ANY POTENTIAL DEVELOPMENT OVER THE LAKE AS THE H850 AND WATER TEMPERATURES DIFFER BY ABOUT 14C. THE BEST CHANCE FOR ANYTHING TO DEVELOP WILL BE BETWEEN 06 AND 15Z FRI...BUT AT THIS TIME WILL KEEP ONLY ISOLATED RAIN OVER THE EASTERN PORTIONS OF THE LAKE AND NOT INTO ERIE PA. && .SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/... AS THE HIGH BUILDS OVERHEAD FRIDAY ANY LAKE ACTIVITY WILL BE SHUT DOWN BY THE DRIER AIR AND THE SINKING INVERSION. LOOK FOR SUNNY SKIES AND TEMPERATURES IN THE 70S. THE HIGH WILL SHIFT EAST ON SATURDAY WHICH WILL SUPPORT SOME WEAK RETURN FLOW WHICH WILL CONTINUE INTO SUNDAY. MEANWHILE THE NW FLOW ALOFT WILL TURN TO THE SW WITH WARMER TEMPERATURES ADVECTING IN WITH H850 REACHING 12C WHICH WILL TRANSLATE INTO GRADUAL WARMING AT THE SURFACE. THE NEXT CHANCE FOR PRECIPITATION WILL BE ASSOCIATED WITH ANOTHER MID LEVEL TROUGH MOVING OUT OF THE ROCKIES. AN ASSOCIATED COLD FRONT WILL REACH THE AREA SUNDAY NIGHT AND WITH WARMER/MOIST AIR AND AN INCREASE IN THE LOW LEVEL JET CAN`T RULE OUT SOME THUNDERSTORMS. && .LONG TERM /MONDAY THROUGH THURSDAY/... A COLD FRONT WILL BE MOVING THROUGH THE EASTERN EDGE OF THE AREA MONDAY MORNING ALONG WITH A FEW LINGERING SHOWERS. COLD ADVECTION WILL OVERSPREAD THE REGION IN THE WAKE OF THE COLD FRONT. THE UPPER AIR PATTERN WILL EXHIBIT A LONG WAVE TROUGH OVER ONTARIO EARLY IN THE EXTENDED WITH THIS FEATURE LIFTING FARTHER NORTH AND ALLOWING A MORE ZONAL FLOW TO DEVELOP. BELOW NORMAL TEMPERATURES ARE EXPECTED WITH GENERALLY DRY CONDITIONS BUT A FEW SHOWERS ARE POSSIBLE WEDNESDAY AFTERNOON AND EVENING MAINLY OVER NORTHWEST PA WHERE A MOIST CYCLONIC FLOW ALOFT ALONG WITH WELL MIXED ADIABATIC CONDITIONS ARE EXPECTED. CONDITIONS WILL WARM ON THURSDAY AND FRIDAY AS THE 850 MB TEMPERATURES RISE TO MORE SEASONAL LEVELS AND MORE SUNSHINE PREVAILS. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... SYNOPTIC AND LAKE EFFECT CLOUDS PRIMARILY AROUND 6K FEET WILL PERIODICALLY PASS OVER SITES NEAREST TO THE LAKESHORE. KERI COULD BRIEFLY SEE A 3.5K FOOT CIG DEVELOP BY DAYBREAK. CLOUDS WILL BEGIN TO BREAK UP FRIDAY AFTERNOON AS HIGH PRESSURE MOVES IN FROM THE SW. DIURNAL CU IS THEN LIKELY TO DEVELOP ACROSS NEOH AND NWPA. THE WIND WILL GRADUALLY DIMINISH THROUGH THE DAY AS THE HIGH APPROACHES. FRIDAY NIGHT THE WIND WILL BECOME LIGHT AND VARIABLE IN THE EAST WITH THE HIGH OVERHEAD...AND SOUTHERLY IN THE WEST. OUTLOOK...NON VFR CONDITIONS POSSIBLE SUNDAY NIGHT WITH THE PASSAGE OF A COLD FRONT AND POSSIBLE SHOWERS AND THUNDERSTORMS. && .MARINE... SMALL CRAFT CONDITIONS PREVAIL IN THE WAKE OF THE COLD FRONT THAT HAS SWEPT EAST THROUGH THE REGION. A RATHER STRONG PRESSURE GRADIENT FOR SUMMER ALONG WITH COLD ADVECTION ALOFT WILL ALLOW MIXING OF HIGHER MOMENTUM AIR TO THE SURFACE. WITH 850 MB TEMPERATURES EXPECTED TO DROP TO NEAR 10C AND LAKE SURFACE TEMPERATURES FROM 22-24C... NEAR ADIABATIC LAPSE RATE IS EXPECTED OVER THE LAKE WHICH WILL PERMIT DEEP MIXING AND STRONGER WINDS TO PREVAIL. WILL CONTINUE WITH SMALL CRAFT ADVISORY THROUGH 08Z EAST OF THE ISLANDS. IT MAY NEED TO BE EXTENDED SLIGHTLY LONGER IN THE EASTERN HALF OF THE LAKE WHERE THE STRONGER PRESSURE GRADIENT WILL LINGER. HIGH PRESSURE WILL GRADUALLY BUILD SOUTH OF THE LAKE FRIDAY AND THEN REMAIN OVER THE REGION INTO THE WEEKEND. WINDS WILL CONTINUE TO DIMINISH FRIDAY AND BE LIGHT ON SATURDAY. SOUTHERLY WINDS WILL INCREASE ON SUNDAY AS ANOTHER FRONTAL BOUNDARY APPROACHES WITH ITS PASSAGE EXPECTED SUNDAY NIGHT. SMALL CRAFT CONDITIONS WILL LIKELY DEVELOP IN THE WAKE OF THAT FRONTAL PASSAGE GIVEN THE COOLING ALOFT DOWN TO JUST BELOW 10C AT 850 MB. WINDS WILL DECREASE ON TUESDAY AS HIGH PRESSURE BUILDS INTO THE REGION. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR LEZ144>149. && $$ SYNOPSIS...JAMISON NEAR TERM...JAMISON/MULLEN SHORT TERM...JAMISON LONG TERM...LAPLANTE AVIATION...MAYERS MARINE...ADAMS/LAPLANTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
124 AM EDT FRI AUG 21 2015 .SYNOPSIS... HIGH PRESSURE OVER THE OHIO VALLEY WILL BUILD EAST INTO PENNSYLVANIA TODAY AND REMAIN OVER THE REGION THROUGH THE UPCOMING WEEKEND. A COLD FRONT WILL MOVE THROUGH THE AREA ON MONDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... WET GROUND...CLEARING SKIES AND A LIGHT WIND PROMOTING PATCHY DENSE FOG ACROSS CENTRAL PA EARLY THIS AM. 11-3.9U SATL IMAGERY SHOWING THE FOG IS MOST PREVALENT ACROSS THE EASTERN HALF OF THE STATE...WHERE THE HEAVIEST RAIN FELL. NEAR TERM MDL SFC RH FIELDS IMPLY THIS WILL REMAIN THE CASE THROUGH DAWN. TEMPS ON TRACK TO BOTTOM OUT FROM THE L50S ACROSS THE NW MTNS...TO THE L-M 60S IN THE FAR SE. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/... THE FRONT IS EXPECTED TO SLOW AND EVENTUALLY STALL OUT AS IT NEARS THE MID ATLC COAST...IN RESPONSE TO STRONG N. ATLC UPPER RIDGE AND UPPER/NON-TROPICAL LOW NEAR BERMUDA. THERE IS SOME CONCERN THAT THE EASTERN MOST PORTIONS OF OUR FORECAST ZONES COULD SEE LINGERING CLOUDS AND A SHOWER....BUT I USED THE HRRR TO DOWNPLAY THIS SCENARIO AS LOW PW AIR MOVES IN. SKIES SHOULD BECOME MOSTLY SUNNY ACROSS CENTRAL AND SOUTHERN PENN...WHILE PERIODS OF BKN-OVC STRATO CU WILL LIKELY FORM ACROSS THE NRN MTNS OF PENN WITH EVEN A FEW SPRINKLES POSSIBLE. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... A RELATIVELY QUIET STRETCH OF WEATHER IS IN STORE THROUGH THIS WEEKEND AND MUCH OF NEXT WEEK. PWATS WILL DROP TO -1SD FRI AND REMAIN THAT WAY THRU THE WEEKEND...WHICH WILL BE A NICE CHANGE FROM THE MUGGY AIRMASS WE SAW MUCH OF THE PAST WEEK. IN ALL...THE WEEKEND LOOKS PLEASANT WITH LOW HUMIDITY AND TEMPERATURES RUNNING A FEW DEGREES BELOW LATE-AUGUST NORMALS. THE ONLY POTENTIAL FLY IN THE OINTMENT IS A WEAK AREA OF LOW PRESSURE OFF THE MID-ATLANTIC COAST THAT COULD TRY TO PUSH A BIT OF CLOUDINESS WESTWARD INTO EASTERN PA ON SUNDAY. A WEAKENING COLD FRONT WILL CROSS THE COMMONWEALTH ON MONDAY...ACCOMPANIED BY AN OUTSIDE CHC FOR A FEW SHRA/TSRA. BEHIND THE FRONT...THE MIDDLE OF NEXT WEEK SHOULD SEE A RETURN TO LOW HUMIDITY AND SLIGHTLY BELOW NORMAL TEMPS. && .AVIATION /05Z FRIDAY THROUGH TUESDAY/... GIVEN THE COPIOUS AMOUNTS OF WIDESPREAD PRECIPITATION THIS AFTERNOON AND EVENING AND THE CLEARING SKIES AND WEAK FLOW EXPECT FOR LOW STRATOCU AND PATCHY DENSE FOG TO DEVELOP OVERNIGHT. IN THE 11U-3.9U THERE IS A LINE OF DRY AIR MOVING IN WHICH WILL LIMIT AND PREVENT FOG/LOW STRATOCU DEVELOPMENT. IPT HAS DECOUPLED WITH LIFR CIGS AND VSBYS. GIVEN THE WESTERLY FLOW EXPECT WESTERN AND CENTRAL TAF SITES TO HAVE PERIODS OF IFR FROM 06Z TO 13Z WITH MVFR TO POSSIBLY VFR IN THE INTERIM. AS THE REGION MIXES OUT AFTER SUNRISE AND DRY AIR MIXES DOWN ANY AREAS OF 1/2SM VSBY FOG WILL TEND TO MVFR BETWEEN 12Z TO 15Z BEFORE BECOMING VFR ACROSS ALL OF CENTRAL AND SOUTHERN PENN. OUTLOOK... SAT-MON...NO SIG WX EXPECTED. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...FITZGERALD/LA CORTE NEAR TERM...FITZGERALD SHORT TERM...LAMBERT/STEINBUGL LONG TERM...EVANEGO AVIATION...LAMBERT/CERU
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
333 AM CDT FRI AUG 21 2015 .SHORT TERM (TODAY THROUGH SATURDAY)... A N-S ORIENTED SHEAR AXIS MOST NOTABLE IN THE MID LEVELS OVER S TX AND ADJACENT AREAS OF NERN MEXICO SHOULD BRING ANOTHER DAY OF CONVECTION AND MODERATED DAYTIME TEMPERATURES FOR THE EASTERN HALF OF SOUTH CENTRAL TX. WHILE THE FRONTAL ZONE THAT BROUGHT WELL BELOW NORMAL MAX TEMPS TO THE AREA THURSDAY HAS RETREATED NORTH...SOME COASTAL TROUGHING IS STILL NOTED NEAR CRP...AND A SMALL COMPLEX OF STORMS CONFIRMS THE UNSTABLE ENVIRONMENT THAT COULD SPREAD INLAND LATER THIS MORNING. RAPID REFRESH MODEL RUNS DEPICT EARLY DESTABILIZATION NEAR AND EAST OF I-35 TODAY...BUT EARLIER RUNS OF THE HRRR WERE SHOWN TO BE TOO AGGRESSIVE WITH CONVECTION IN THE PRE-DAWN HOURS. ADDITIONAL MOISTURE AND POSSIBLE INSTABILITY IS MOVING IN FROM NW FLOW ALOFT FROM WEST TX...BUT WITH ONLY THE 00Z NSSL WRF MODEL SHOWING AN IMPACT OVER OUR WESTERN COUNTIES VERSUS SEVERAL THAT DO NOT...WILL STICK WITH THE CONSENSUS POPS FOR THE SERN TWO-THIRDS OF THE FORECAST AREA. BLENDED GUIDANCES CONTAIN ARTIFACTS OF EARLIER FORECAST HIGHER TEMPS...SO OPTED FOR A BLEND OF MAV/MET FOR HIGHS. MODEL RUN TO RUN TRENDS IN THE EARLY PERIODS SHOW MORE SHEAR THAN EARLIER RUNS...SO WILL FOLLOW THIS TREND TO KEEP A SLIGHTLY LESS STABLE PICTURE FOR OUR SOUTHERN/WRN COUNTIES FOR SATURDAY. INCREASED RIDGING AND DRY AIR ENTRAINMENT FROM THE NORTH SHOULD PRECLUDE CONVECTION OVER MOST OF SOUTH CENTRAL TEXAS...BUT THE WESTWARD SHIFTING SHEAR AXIS SHOULD PULL SOME MOISTURE WITH IT TO BRING A SLIGHT CHANCE OF DAYTIME CONVECTION OVER THE RIO GRANDE PLAINS. MEANWHILE SOUTHERN PARTS OF THE COASTAL PLAINS LOSE THE CYCLONIC SHEAR BUT MAINTAIN LOCALLY HIGHER PWAT VALUES FOR ONE MORE DAY. WILL FAVOR THE GFS BASED GUIDANCE FOR WARMER TEMPS TO REGAIN CONTROL OVER CENTRAL TX WHERE THE DRIER AND MORE STABLE MID- LEVEL AIR MOVES IN. && .LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)... THE BRIEF BREAK FROM THE HEAT IS ALL BUT FORGOTTEN BY SUNDAY. THE GFS AND ECMWF BOTH BUILD A STRONG RIDGE OVER THE SOUTHERN ROCKIES WITH AN AXIS THAT EXTENDS SE ACROSS CENTRAL TX. WILL SHADE TOWARD THE HIGHER MEX GUIDANCE ON MAXES SUNDAY THROUGH WEDNESDAY AS AUGUST RAINS HAVE BEEN MOSTLY TOO SPARSE TO PROVIDE FEEDBACK THROUGH SOIL AND VEGETATION. LATE MONDAY THROUGH DAYTIME WEDNESDAY...THERE IS A SIGNAL FOR MID-LEVEL MOISTURE POOLING TO SPREAD SOUTH FROM NORTH TX AS NORTHERLY FLOW INCREASES ALOFT. THUS WILL SHADE TOWARD THE SLIGHTLY MORE UNSTABLE ECMWF OVER THE SLIGHTLY DRIER GFS FOR THOSE DAYS. LITTLE OR NO CONVECTION IS SHOWN BY EITHER MODEL FOR THE REMAINDER OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 94 76 98 77 99 / 20 10 10 - - AUSTIN BERGSTROM INTL AIRPORT 93 73 97 75 98 / 30 10 10 - - NEW BRAUNFELS MUNI AIRPORT 94 75 98 76 98 / 30 10 10 - - BURNET MUNI AIRPORT 93 74 97 75 98 / 10 10 10 - - DEL RIO INTL AIRPORT 96 76 98 78 99 / 10 - 20 - - GEORGETOWN MUNI AIRPORT 92 76 96 76 98 / 20 10 10 - 10 HONDO MUNI AIRPORT 95 74 96 75 97 / 20 10 10 - - SAN MARCOS MUNI AIRPORT 93 75 98 76 99 / 30 10 10 - - LA GRANGE - FAYETTE REGIONAL 93 76 96 76 98 / 40 20 20 10 10 SAN ANTONIO INTL AIRPORT 93 76 97 77 98 / 30 10 10 - - STINSON MUNI AIRPORT 94 76 98 77 99 / 30 20 10 - - && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...ALLEN SYNOPTIC/GRIDS...OAKS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
318 AM CDT FRI AUG 21 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 318 AM CDT FRI AUG 21 2015 MOST OF THE FORECAST TIME THIS MORNING WAS ENSURING WE WERE ON TRACK WITH RAIN CHANCES IN THE RETURN FLOW TODAY....CLOUDS ON SATURDAY...BUT MAINLY THE SATURDAY NIGHT THUNDERSTORM THREATS AND ANY MESSAGING THAT WILL BE NEEDED FOR THOSE OUTDOORS. CURRENT OBSERVATIONAL DATA AS OF 21.07Z INDICATES NW-SE ORIENTED CLOUD BANDING AROUND 10KFT ACROSS CENTRAL MN ASSOCIATED WITH FRONTOGENESIS IN THE 800-900 MB LAYER PER LATEST RAP ANALYSIS. TSRA AND LIGHTNING IN NWRN IA ON THE NOSE OF THE LOW-LEVEL JET PER 88D VWPS AND RAP ANALYSIS. SPC MESOANALYSIS SHOWING THAT TSRA IS ON THE NORTHERN EXTENT OF THE MUCAPE REGION /ONLY ABOUT 250 J/KG THERE/. GOES FOG PRODUCT AND SURFACE OBSERVATIONS SHOW A LOWER CLOUD FIELD OVER OK/TX SOUTH IN A RICH MOIST POOL OF SURFACE DEWPOINTS OVER 65F...AND 925MB DEWPOINTS AT 18C PER 21.00Z RAOBS. WILL HAVE TO WATCH THIS AREA AS IT ADVECTS NORTHWARD AHEAD OF THE FRONT THAT IS MOVING IN FOR SATURDAY NIGHT...ASSOCIATED WITH THE SHORTWAVE TROUGH NOW WORKING SOUTHWARD THROUGH BRITISH COLUMBIA /PER GOES WATER VAPOR/. RAP ANALYSIS INDICATES THIS SPINNER HAS A TROPOPAUSE FOLD DOWN TO ROUGHLY 750 MB...SO A POTENT VORTEX. SHORT TERM GUIDANCE SUPPORTS EVOLVING THE FRONTOGENESIS AND THE LOW-LEVEL JET NOSE CONVERGENCE NORTHEAST THROUGH THE FIRST PORTION OF TODAY INTO NRN WI BY AFTERNOON. THERE WILL LIKELY BE VERY LIGHT RADAR RETURNS AND PER 00Z RAOB DATA...SOME PRETTY DRY AIR TO OVERCOME BELOW THE ACCAS CLOUD BASE /10KFT/. FOR NOW...HAVE KEPT THE HIGHER PROBABILITY DRY FORECAST. SPRINKLES OR AN ISOLATED WETTING SHOWER MAY BE POSSIBLE WITH FORCING EVOLUTION NEWRD. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 318 AM CDT FRI AUG 21 2015 NO BIG CHANGES DURING THIS PERIOD. SOUTHWESTERLY FLOW WILL PREVAIL SATURDAY AND PRE-FRONTALLY WILL NEED TO WATCH THE SURGE OF 925 MB MOISTURE NORTHWARD TONIGHT. CONSENSUS 21.00Z GUIDANCE SUGGESTS THIS TONGUE REMAINS WEST OF THE AREA UNTIL FRONT ARRIVES SAT EVENING. HAVE INCREASED WIND GUSTS SATURDAY WITH STRONGER LOW-LEVEL WIND FIELD SUGGESTED AND MIXING DEPTH INTO THE 35-38KT CONSENSUS 900MB WINDS. TIMING IS ABOUT THE SAME AS PREVIOUS FORECASTS FOR FRONT TO BECOME ACTIVE TO THE WEST OF THE AREA LATER SATURDAY. THIS FRONT IS ASSOCIATED WITH THE BRITISH COLUMBIA SHORTWAVE AS IT DIGS SOUTHEAST INTO CENTRAL MN...THEN EJECTS NORTHEAST OVER DULUTH. THUS...THE AREA ISNT DIRECTLY HIT BY THE MID-UPPER TROPOSPHERIC FORCING...WHICH FAVORS BETTER CONVECTION TO EJECT NORTHEAST...BUT BROAD ASCENT FROM LARGE SCALE FORCING IS OVER THE AREA. THE CAPE AXIS IS VERY NARROW...RIGHT ALONG THE FRONT...WITH A STOUT CAP OUT AHEAD SUGGESTED. MUCAPE HAS REMARKABLE DROP SUGGESTED IN THE MODEL GUIDANCE FROM 7PM TO 1 AM...ABOUT 2500 IN PEAK HEATING WEST OF THE FORECAST AREA...TO ABOUT 750 J/KG BY 1 AM ON THE MISS RIVER. THE WESTERN FORECAST AREAS OF NERN IA AND SERN MN HAVE THE MOST POTENTIAL FOR SEVERE STORMS FOR A SMALL WINDOW SATURDAY EVENING AS THE STORMS WEAKEN HEADING EAST. SPC DAY 2 RISK HAS SHIFTED THE SLIGHT RISK EAST INTO THAT AREA...BUT NOT TOO MUCH HAS CHANGED. MODEST 0-3KM WIND SHEAR WOULD FAVOR LINE SEGMENTS PROMOTING DAMAGING WINDS. THE 0-3KM SHEAR VECTOR IS ALIGNED PERPENDICULAR TO THE FRONT OR CONVECTIVE LINE...PROMOTING BETTER COLD POOL MAINTENANCE. SEVERE THREAT DEPENDS ON TIMING OF THE FRONT AND STORMS. ARRIVAL IN THE EARLY EVENING WOULD FAVOR HIGHER SEVERE STORM CHANCES PER HIGHER CAPE IN MODEST LOW-LEVEL SHEAR. CONSENSUS MODEL GUIDANCE IS A MID-LATER EVENING APPROACH OF STORMS IN NERN IA AND SERN MN WITH STORMS JUST PAST PEAK AND INTO WEAKENING STAGE...WITH COLD POOLS THAT COULD PROBABLY PRODUCE ISOLATED WIND DAMAGE. WILL TAKE A SLIGHT STEP UP IN MESSAGING MOVING TO STRONG TO ISOLATED SEVERE STORMS. A COOL FIRST HALF OF THE WEEK IN NORTHWEST FLOW WITH DRIER CONDITIONS AND BELOW NORMAL TEMPERATURES...WARMING LATE WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1128 PM CDT THU AUG 20 2015 VFR CONDITIONS EXPECTED. AS SURFACE RIDGE QUICKLY PASSES TONIGHT...ALREADY SEEING RESPONSE OF APPROACHING SHORT WAVE TROUGH COMING THROUGH CENTRAL PLAINS. LOW LEVEL JET ACROSS WESTERN IOWA INTO MINNESOTA IS HELPING WITH FRONTOGENETIC BAND SETTING UP IN THE FORM OF MID LEVEL CLOUDS THAT HAVE FORMED ACROSS MINNESOTA LAST FEW HOURS. LOW LEVEL MOISTURE TRANSPORT HAS ALSO LED TO SOME CLOUDS AND ISOLATED SHOWERS FURTHER WEST. GIVEN SUCH DRY AIRMASS AND ONLY MODEST LIFT WITH WAVE... WILL NOT INTRODUCE ANY RAIN. THIS FOCUS AREA SHIFTS EAST OF THE AREA AFTER DAYBREAK FRIDAY...SO OUTSIDE OF A FEW DAYTIME CUMULUS CLOUDS THAT COULD FORM...LOOKING AT A TRANQUIL AVIATION PERIOD. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BAUMGARDT LONG TERM...BAUMGARDT AVIATION...SHEA
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
502 AM MST FRI AUG 21 2015 .UPDATE...TO AVIATION AND FIRE WEATHER DISCUSSIONS... && .SYNOPSIS... THUNDERSTORMS WILL GENERALLY REMAIN CONFINED TO THE HIGHER TERRAIN OF SOUTHERN AND EASTERN ARIZONA THROUGH THE WEEKEND. THE MONSOON HIGH WILL SETTLE ACROSS THE FOUR CORNERS MONDAY...RESULTING IN BETTER RAIN CHANCES ACROSS THE LOWER DESERTS. DRIER CONDITIONS WILL RETURN BY MIDWEEK ALONG WITH NEAR TO ABOVE NORMAL TEMPERATURES. && .DISCUSSION... AN ANTICYCLONE IN THE MID AND UPPER LEVELS REMAINS POSITIONED OFF THE BAJA PENINSULA...RESULTING IN A WESTERLY COMPONENT TO THE FLOW. AT THE SURFACE...YUMA VWP SUGGESTS THAT A SHALLOW GULF SURGE IS TAKING PLACE ACROSS SOUTHWESTERN AZ. DEWPOINTS NEAR YUMA AND ACROSS THE IMPERIAL VALLEY HAVE RESPONDED...INCREASING INTO THE MID TO UPPER 70S EARLY THIS MORNING. FURTHER EAST ACROSS THE LOWER DESERTS OF SOUTH-CENTRAL AZ...AN INFLUX OF MOISTURE IS ALSO ANTICIPATED THIS MORNING...BUT TO A LESSER DEGREE. SOME EARLIER WRF-BASED GUIDANCE INDICATED THAT SHOWERS AND THUNDERSTORMS WOULD DEVELOP THIS MORNING ACROSS PORTIONS OF THE LOWER DESERTS. HOWEVER...THE LATEST LOCAL WRFS AND U OF ARIZONA WRFS HAVE BACKED OFF CONSIDERABLY AND DEPICT CONVECTION BEING MOST CONCENTRATED ACROSS THE HIGHER TERRAIN SOUTH AND EAST OF PHOENIX THIS AFTERNOON. SEVERAL RUNS OF THE HRRR HAVE ALSO DISMISSED THE POSSIBILITY OF CONVECTION STARTING EARLY THIS MORNING...THOUGH CAPES ABOVE 1000 J/KG SHOULD CERTAINLY SUPPORT DEVELOPMENT BY EARLY AFTERNOON. LACK OF A TRIGGER IN THE UPPER LEVELS ALONG WITH WEAK WESTERLY FLOW POINT TO TERRAIN- BASED CONVERGENCE AS THE PRIMARY LIFTING MECHANISM. NEVERTHELESS...THERE IS A SLIGHT CHANCE OF THUNDERSTORMS IN THE PHOENIX AREA...THOUGH THE GREATER LIKELIHOOD IS FOR AREAS OF BLOWING DUST. MEAN FLOW WILL BECOME MORE WESTERLY SATURDAY AS THE ANTICYCLONE DRIFTS NORTHWARD. THIS WILL AGAIN CONFINE THUNDERSTORMS MAINLY TO THE HIGHER TERRAIN EAST OF PHOENIX. MORE OF THE SAME FOR SUNDAY AS THE HIGH DRIFTS OVERHEAD. CONDITIONS WILL BECOME SOMEWHAT MORE FAVORABLE FOR PRECIPITATION EARLY NEXT WEEK AS THE MONSOON HIGH BECOMES REESTABLISHED ACROSS THE FOUR CORNERS. INCREASING EASTERLY COMPONENT TO THE FLOW GENERALLY FAVORS HIGHER CHANCES OF THUNDERSTORMS. HOWEVER...MODEL CROSS SECTIONS INDICATE THAT ABUNDANT MOISTURE IN THE MID AND UPPER LEVELS MAY RESULT IN CONSIDERABLE CLOUDINESS AND ULTIMATELY A DECREASE IN INSTABILITY AND THE POTENTIAL FOR THUNDERSTORMS ACROSS THE AREA. OPERATIONAL GFS AND ECMWF ALSO SUGGEST THE PRESENCE OF AN INVERTED TROUGH ACROSS NORTHERN SONORA...THOUGH DIFFERENCES IN THE STRENGTH AND TIMING OF THIS FEATURE ARE APPARENT. GENERAL CONSENSUS AMONG THE MODELS FOR NEXT WEEK IS THAT THE MONSOON HIGH WILL DRIFT EASTWARD AND SOUTHWARD. FLOW WILL GRADUALLY BECOME SOUTHWESTERLY AGAIN...FAVORING THE HIGHER TERRAIN FOR CONVECTION. TEMPERATURES AT OR ABOVE NORMAL ARE EXPECTED THROUGH THE EXTENDED. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL AND SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... EARLY AM SCT-BKN CLOUDS BETWEEN PHX AND CGZ WILL SETTLE OUT TO FEW- SCT MID-LEVEL CLOUDS FOR THE AFTN...WITH SKIES REMAINING MOSTLY CLEAR FOR THE WESTERN TERMINALS OF BLH AND IPL. S-SE AM WINDS TO PREVAIL FOR THE TERMINALS SAVE FOR KPHX...WHICH WILL MAINTAIN SUBTLE W-NW HEADINGS WITH PERIODS OF VRB. AFTN WINDS TO BECOME S-SW FOR THE PHX AREA TERMINALS...WITH PERIODS OF 20KT GUSTINESS. ISO TS SHOULD FORM WELL EAST AND SOUTH OF THE PHX AREA...WITH VERY REMOTE CHANCES OF OUTFLOW RELATED IMPACTS INTO KIWA DURING THE EVENING. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SUNDAY THROUGH THURSDAY... MONSOON MOISTURE LEVELS AND HUMIDITIES WILL PERSIST THROUGH MIDWEEK. STORM CHANCES WILL CONTINUE FOR THE HIGHER TERRAIN LOCALES FOR SUNDAY BEFORE EXPANDING INTO THE LOWER DESERT ELEVATIONS BY THE EARLY WORK WEEK AS SOME UPPER LEVEL DISTURBANCES PASS THROUGH THE AREA AND SUPPORT THE POTENTIAL FOR MORE WIDESPREAD STORM DEVELOPMENT. DAYTIME HUMIDITIES WILL RANGE FROM THE 20 TO 30 PERCENT RANGE WHILE MAKING GOOD OVERNIGHT RECOVERIES. OUTSIDE OF THUNDERSTORM OUTFLOW AND VICINITY WINDS...SFC WINDS TO MAINTAIN DAYTIME HEADINGS 10 TO 20 MPH WHILE BECOMING DOWN DRAINAGE/DOWN VALLEY IN THE OVERNIGHTS. A SLIGHT DRAW DOWN OF MONSOON MOISTURE AND INTRUSION OF WESTERLY FLOW ALOFT WILL RELEGATE STORM CHANCES BACK ACROSS EASTERN AZ FOR THE LATTER PART OF THE WEEK...WHILE TEMPERATURES ALSO BEGIN TO WARM TO ABOVE NORMAL VALUES. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...HIRSCH AVIATION...NOLTE FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
328 AM MST FRI AUG 21 2015 .SYNOPSIS... THUNDERSTORMS WILL GENERALLY REMAIN CONFINED TO THE HIGHER TERRAIN OF SOUTHERN AND EASTERN ARIZONA THROUGH THE WEEKEND. THE MONSOON HIGH WILL SETTLE ACROSS THE FOUR CORNERS MONDAY...RESULTING IN BETTER RAIN CHANCES ACROSS THE LOWER DESERTS. DRIER CONDITIONS WILL RETURN BY MIDWEEK ALONG WITH NEAR TO ABOVE NORMAL TEMPERATURES. && .DISCUSSION... AN ANTICYCLONE IN THE MID AND UPPER LEVELS REMAINS POSITIONED OFF THE BAJA PENINSULA...RESULTING IN A WESTERLY COMPONENT TO THE FLOW. AT THE SURFACE...YUMA VWP SUGGESTS THAT A SHALLOW GULF SURGE IS TAKING PLACE ACROSS SOUTHWESTERN AZ. DEWPOINTS NEAR YUMA AND ACROSS THE IMPERIAL VALLEY HAVE RESPONDED...INCREASING INTO THE MID TO UPPER 70S EARLY THIS MORNING. FURTHER EAST ACROSS THE LOWER DESERTS OF SOUTH-CENTRAL AZ...AN INFLUX OF MOISTURE IS ALSO ANTICIPATED THIS MORNING...BUT TO A LESSER DEGREE. SOME EARLIER WRF-BASED GUIDANCE INDICATED THAT SHOWERS AND THUNDERSTORMS WOULD DEVELOP THIS MORNING ACROSS PORTIONS OF THE LOWER DESERTS. HOWEVER...THE LATEST LOCAL WRFS AND U OF ARIZONA WRFS HAVE BACKED OFF CONSIDERABLY AND DEPICT CONVECTION BEING MOST CONCENTRATED ACROSS THE HIGHER TERRAIN SOUTH AND EAST OF PHOENIX THIS AFTERNOON. SEVERAL RUNS OF THE HRRR HAVE ALSO DISMISSED THE POSSIBILITY OF CONVECTION STARTING EARLY THIS MORNING...THOUGH CAPES ABOVE 1000 J/KG SHOULD CERTAINLY SUPPORT DEVELOPMENT BY EARLY AFTERNOON. LACK OF A TRIGGER IN THE UPPER LEVELS ALONG WITH WEAK WESTERLY FLOW POINT TO TERRAIN- BASED CONVERGENCE AS THE PRIMARY LIFTING MECHANISM. NEVERTHELESS...THERE IS A SLIGHT CHANCE OF THUNDERSTORMS IN THE PHOENIX AREA...THOUGH THE GREATER LIKELIHOOD IS FOR AREAS OF BLOWING DUST. MEAN FLOW WILL BECOME MORE WESTERLY SATURDAY AS THE ANTICYCLONE DRIFTS NORTHWARD. THIS WILL AGAIN CONFINE THUNDERSTORMS MAINLY TO THE HIGHER TERRAIN EAST OF PHOENIX. MORE OF THE SAME FOR SUNDAY AS THE HIGH DRIFTS OVERHEAD. CONDITIONS WILL BECOME SOMEWHAT MORE FAVORABLE FOR PRECIPITATION EARLY NEXT WEEK AS THE MONSOON HIGH BECOMES REESTABLISHED ACROSS THE FOUR CORNERS. INCREASING EASTERLY COMPONENT TO THE FLOW GENERALLY FAVORS HIGHER CHANCES OF THUNDERSTORMS. HOWEVER...MODEL CROSS SECTIONS INDICATE THAT ABUNDANT MOISTURE IN THE MID AND UPPER LEVELS MAY RESULT IN CONSIDERABLE CLOUDINESS AND ULTIMATELY A DECREASE IN INSTABILITY AND THE POTENTIAL FOR THUNDERSTORMS ACROSS THE AREA. OPERATIONAL GFS AND ECMWF ALSO SUGGEST THE PRESENCE OF AN INVERTED TROUGH ACROSS NORTHERN SONORA...THOUGH DIFFERENCES IN THE STRENGTH AND TIMING OF THIS FEATURE ARE APPARENT. GENERAL CONSENSUS AMONG THE MODELS FOR NEXT WEEK IS THAT THE MONSOON HIGH WILL DRIFT EASTWARD AND SOUTHWARD. FLOW WILL GRADUALLY BECOME SOUTHWESTERLY AGAIN...FAVORING THE HIGHER TERRAIN FOR CONVECTION. TEMPERATURES AT OR ABOVE NORMAL ARE EXPECTED THROUGH THE EXTENDED. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL AND SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... MOSTLY CLEAR SKIES AND LIGHT WINDS AT THE TERMINAL SITES EXPECTED OVERNIGHT THROUGH MID-DAY FRIDAY. ISOLATED THUNDERSTORMS WILL FORM WELL EAST AND SOUTH OF PHOENIX AREA TERMINALS AFTER 20Z FRIDAY... WITH SOUTHWEST AZ AND SOUTHEAST CA DESERT SITES REMAINING DRY. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SATURDAY THROUGH WEDNESDAY... INCREASING MONSOON MOISTURE FROM MEXICO IS EXPECTED THIS PERIOD. A SLIGHT CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS ARE FORECAST OVER THE SOUTHERN GILA COUNTY MOUNTAINS THIS WEEKEND. THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL SPREAD WEST ACROSS MUCH OF SOUTHWEST AND SOUTH CENTRAL ARIZONA MONDAY THROUGH WEDNESDAY. MINIMUM RELATIVE HUMIDITY BECOMING 20 TO 30 PERCENT. SOUTH TO SOUTHWEST AFTERNOON DIURNAL WINDS 10 TO 20 MPH. FAIR RECOVERY OVERNIGHT. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...HIRSCH AVIATION...MEYERS FIRE WEATHER...VASQUEZ
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
425 AM PDT FRI AUG 21 2015 .SYNOPSIS... DRY WEATHER WITH NEAR NORMAL TEMPERATURES THROUGH EARLY NEXT WEEK. HAZY/SMOKY CONDITIONS WILL CONTINUE IN PORTIONS OF NORCAL. && .DISCUSSION... The Delta Breeze is still healthy early this morning which is keeping temperatures in the upper 50s to mid 60s. And speaking of temperatures, the short term forecast into Monday will be reasonable & seasonable. Daytime highs will generally oscillate within 5 degrees of normal. For areas influenced by the Delta Breeze, daytime highs will be near to slightly below normal while other areas will be near to slightly above normal. For today, Valley highs will range upper 80s (near Delta) to upper 90s (near Redding) while max temps in higher terrain will range in the 70s (higher elevations of the Sierra) to the upper 80s/low 90s (foothill locations). Very subtle warming occurs starting Saturday as ridging strengthens over NorCal. The main concern in the short term are the hazy/smoky conditions due to fires that continue to burn, especially the many fires in Trinity County. The HRRR model showed that smoke particulates from the Trinity vicinty could move southward today towards Sacramento area and then curl around as the Delta Breeze moves northward up the valley. It`s going to be tricky to know where the worst smoke conditions will be, but it`s a safe bet that much of interior NorCal will at least be hazy the next several days. JBB && .EXTENDED DISCUSSION (Tuesday THROUGH Friday) Near normal temperatures on Tuesday will be followed by temperatures trending down through the rest of the week into the weekend as a cool trough from the Gulf of Alaska approaches. How quickly this system moves in is still in doubt, as the 00Z GFS and ECMWF have essentially traded positions from model runs yesterday, with the GFS now keeping a closed low off the coast and the ECMWF bringing a quicker moving trough in on Friday. This would bring the potential for some precipitation into far northern California late Friday. While the GFS does keep the main low off the coast, it does have a weak shortwave on Friday afternoon. Have introduced just a slight chance of rain showers for the northern Coastal Range for Friday afternoon. Will be watching to see if later model runs trend closer together and need to expand this later. Current Global Ensemble Forecast System (GEFS) ensembles and analogs are pointing towards a cool down for late in the week. Highs by Friday may stay in the 80s, even over the northern Sacramento Valley. Increased cloud cover if the trough moves inland would be a factor in this. EK && .AVIATION... General VFR conditions expected over the next 24 hours. MVFR with local IFR cigs expected through the Delta until 17z, with SCT010 possible into the Sacramento metro area. Delta breeze wind gusts to 30 kt through 17z. Mid level clouds over the northern Sacramento Valley through this morning. Wildfire smoke around 5000 ft over the southern Sacramento Valley, and may extend to the surface bringing some haze at times, local MVFR/IFR conditions for the Coastal Range. EK && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
949 AM EDT FRI AUG 21 2015 .UPDATE... OLD FRONTAL BOUNDARY CURRENTLY DRAPED ACROSS CENTRAL GA THIS MORNING. IN THE MID LEVELS...A SHEAR AXIS IS SITUATED ALMOST DIRECTED ON TOP OF THE BOUNDARY. WV AND 500MB RAP ANALYSIS SHOWS A WEAK WAVE SHORTWAVE ASSOCIATED WITH THE SHOWERS ACROSS EASTERN GA THIS MORNING. THERE ARE TWO MORE SHORTWAVES ANALYZED IN THE FLOW...ONE ACROSS CENTRAL AL AND ANOTHER ACROSS THE ARKLAMISS. THE WAVE ACROSS CENTRAL AL SHOULD HELP SCT CONVECTION DEVELOP THIS AFTERNOON DURING PEAK HEATING ACROSS MUCH OF THE CWFA. HAVE UPDATED THE POPS ACCORDING TO THE LATEST RADAR TRENDS. HAVE ALSO TWEAKED THE AFTERNOON POPS A BIT TO COME A LITTLE MORE INTO LINE WITH THE HRRR...WHICH HAS A PRETTY GOOD HANDLE ON THE SHRA THAT ARE ONGOING. LOCALLY HEAVY RAINFALL AND FREQUENT LIGHTNING STRIKES ARE THE MAIN HAZARDS ASSOCIATED WITH ANY THUNDERSTORMS THIS AFTERNOON. && .PREV DISCUSSION... /ISSUED 718 AM EDT FRI AUG 21 2015/ PREV DISCUSSION... /ISSUED 414 AM EDT FRI AUG 21 2015/ SHORT TERM /TODAY THROUGH SATURDAY/... NAM/GFS/ECMWF IN VERY GOOD AGREEMENT THROUGH THE SHORT TERM. SURFACE TROUGH HAS STALLED ACROSS NORTH GEORGIA KEEPING MOST OF THE CWA IN THE WARM AND MOIST SECTOR. THIS TROUGH WILL NOT MOVE MUCH BUT SHOULD BE A FOCUS FOR CONVECTION THIS AFTERNOON AS A WEAK WAVE MOVES ALONG THE BOUNDARY. AFTER THIS WAVE MOVES TO OUR EAST...THE SURFACE TROUGH WILL SHIFT SOUTH. CAPES REMAIN IN THE 1500-2000 RANGE ALONG WITH PWATS RANGING FROM 1.8 TO 2.1 INCHES. WILL KEEP HIGH CHANCE POPS ACROSS NORTH AND PARTS OF CENTRAL GA WHERE THE DEEPEST MOISTURE WILL BE WITH CHANCE POPS ELSEWHERE. CONVECTION WILL DIMINISH QUICKLY THIS EVENING. ON SATURDAY EXPECT CONVECTION AGAIN ALTHOUGH WITH SLIGHTLY DRIER AIR OVER THE REGION WILL LIMIT POPS TO SLIGHT CHANCE TO CHANCE AND MAINLY DURING THE AFTERNOON. GUIDANCE TEMPS HAVE BEEN RUNNING 1 TO 2 DEGREES TOO LOW OVER THE PAST 10 DAYS AND HAVE THEREFORE RAISED MAX TEMPS BOTH DAYS BY A DEGREE OR TWO. 17 LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE EXTENDED FORECAST START OFF WITH WEAKENING BOUNDARY ACROSS CENTRAL GA SUNDAY MOVING SOUTH. THE NEXT FRONTAL SYSTEM BEGINS TO MOVE INTO N GA MONDAY MORNING BUT THERE IS NOT MUCH MOISTURE ASSOCIATED WITH IT. THIS BOUNDARY WILL ACT AS A CATALYST FOR STORMS TO DEVELOP ACROSS THE AREA MONDAY AND TUESDAY BUT IT WILL ALSO USHER IN A MUCH DRIER AIRMASS TUESDAY NIGHT. THIS DRIER AIR IS EXPECTED TO STAY ACROSS THE REGION THROUGH THURSDAY WHICH WILL KEEP SHRA/TSRA ACTIVITY TO A MINIMUM. ALL IN ALL IT LOOKS LIKE WE MAY BE IN THE BEGINNING STAGES OF TRANSITIONING TO A MORE FALL LIKE PATTERN...WITH FRONTS MOVING THROUGH THE STATE GIVING THE CWA MOSTLY CLEAR SKIES FOR A FEW DAYS AND NOT STALLING ACROSS CENTRAL OR SOUTH GA. TEMPS REMAIN IN THE MID 80S TO MID 90S THROUGH THE EXTENDED. 01 AVIATION... 12Z UPDATE... ISOLATED LIGHT SHOWERS HAVE DEVELOPED AROUND THE ATL AREA AND WILL ADD A VCSH IN THE ATL AREA TAFS AND ALSO AHN. VERY THIN AREAS OF IFR CIGS ALSO AROUND THE ATL AREA AND WILL NEED TO INCLUDE SCT-BKN IFR CIGS THIS MORNING. THERE SHOULD BE SOME INITIAL LIFTING WITH DAYTIME HEATING WHICH WILL BRING SCT-BKN MVFR CIGS LATER THIS MORNING BUT BECOMING VFR BY NOON. EXPECT SCATTERED TSRA TO DEVELOP THIS AFTERNOON AND DIMINISH RAPIDLY AFTER SUNSET. //ATL CONFIDENCE...12Z UPDATE... LOW TO MEDIUM ON CIGS EARLY THIS MORNING MEDIUM ON TIMING OF CONVECTION HIGH ON REMAINING ELEMENTS 17 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 90 71 89 71 / 50 50 30 20 ATLANTA 89 71 90 73 / 50 50 30 20 BLAIRSVILLE 82 65 84 63 / 40 40 30 20 CARTERSVILLE 89 69 91 69 / 40 50 30 10 COLUMBUS 91 74 93 75 / 40 40 20 20 GAINESVILLE 86 71 87 71 / 50 50 30 20 MACON 92 73 93 73 / 40 40 20 20 ROME 87 68 90 69 / 40 50 30 10 PEACHTREE CITY 89 70 91 71 / 50 50 30 20 VIDALIA 93 76 94 74 / 40 40 20 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM... AVIATION...
AREA FORECAST DISCUSSION
NWS DES MOINES IA
650 AM CDT FRI AUG 21 2015 ...UPDATED AVIATION DISCUSSION... .SHORT TERM /TODAY/... ISSUED AT 346 AM CDT FRI AUG 21 2015 MAIN FORECAST CONCERN WAS FOCUSED ON TEMPERATURES AND WINDS FOR THIS AFTERNOON...AND WITH WEAK SHORTWAVE PROVIDING SOME ISOLATED SHOWERS/STORMS THROUGH THE MID-MORNING. A FEW ELEVATED SHOWERS/STORMS HAVE DEVELOPED OVER WEST-CENTRAL TO NORTHWEST IOWA AND LOOK TO MEANDER INTO NORTH-CENTRAL IOWA THROUGH 15Z THIS MORNING. THERE IS ENOUGH FORCING AND ELEVATED INSTABILITY...ALBEIT VERY WEAK...BUT ENOUGH TO WARRANT SLIGHT/LOW CHANCE POPS OVER THE NORTH. HOWEVER WITH A A STRONG CAP IN PLACE TODAY...IT WILL LIMIT ANYTHING PAST 15Z. THE LATEST 21.07Z HRRR HAS A DECENT HANDLE ON THE CONVECTIVE TRENDS AND LEANED TOWARD ITS SOLUTION FOR POPS/WX. STRONG MIXING AND WAA DEVELOP TODAY AS PRESSURE GRADIENT TIGHTENS THIS AFTERNOON. MIXING TO AROUND 850MB PUTS HIGHS IN THE LOWER 80S AND TWEAKED MAX TEMPS UP SLIGHTLY. THE MAV/ECS HAD A GREAT HANDLE ON TEMPS TODAY AS THE MET WAS TOO COLD THROUGHOUT THE FORECAST AREA. ALSO TWEAKED UP WINDS SLIGHTLY AS WINDS ATOP THE MIXED LAYER IN THE 25-30 KNOT RANGE. .LONG TERM /TONIGHT THROUGH THURSDAY/... ISSUED AT 346 AM CDT FRI AUG 21 2015 THE LONG TERM FORECAST IS CHARACTERIZED BY VARYING TEMPERATURES AND MOSTLY DRY CONDITIONS BUT PUNCTUATED AND HEADLINED BY THE STORM SYSTEM MOVING ACROSS THE REGION ON SATURDAY AND SATURDAY NIGHT. THE DRIVER FOR THIS SYSTEM WILL COME IN THE FORM OF A MID/UPPER LEVEL TROUGH...STRONG FOR THIS SEASON...MOVING ACROSS THE NORTHERN ROCKIES ON FRIDAY NIGHT AND OVER THE DAKOTAS AND MINNESOTA ON SATURDAY AND SATURDAY NIGHT. THIS WILL BE REFLECTED AT THE SURFACE BY A STEADILY STRENGTHENING TROUGH/FRONT...INITIALLY STRETCHING DOWN THE HIGH PLAINS AND THEN SWEEPING EAST/SOUTHEAST IN RESPONSE TO THE PROGRESSION OF THE MID/UPPER TROUGH ON SATURDAY/SATURDAY NIGHT. AHEAD OF THIS SYSTEM MOST OF SATURDAY WILL BE WARM AND INCREASINGLY BREEZY ACROSS OUR FORECAST AREA AS THE SURFACE PRESSURE GRADIENT TIGHTENS UP BETWEEN THE HIGH PLAINS TROUGH AND A LARGE HIGH PRESSURE AREA DEPARTING TO THE EAST. FOR MUCH OF THE DAY THINGS WILL REMAIN QUIET...BUT BY PEAK HEATING IN THE LATE AFTERNOON/EVENING INSTABILITY WILL BE MAXIMIZED AND THE SURFACE FRONT WILL SERVE AS A MECHANISM FOR THUNDERSTORM DEVELOPMENT COINCIDENT WITH THE ARRIVAL OF STRONGER FORCING AND WIND FIELDS ALOFT GIVEN THE APPROACH OF THE MID/UPPER TROUGH. INITIAL STORMS WILL LIKELY BE ORGANIZED WITHIN THIS ENVIRONMENT PROVIDING A FAIRLY SUBSTANTIAL SEVERE WEATHER THREAT...THEN AS THE SYSTEM MOVES EAST/SOUTHEAST WITH SUNSET THE STORMS SHOULD BECOME MORE LINEAR AND GRADUALLY DIMINISH IN INTENSITY BY THE TIME THEY REACH EASTERN IOWA. FOR NOW THE PRIMARY QUESTIONS ARE WHERE THE STORMS WILL INITIALLY DEVELOP...OVER SOUTH DAKOTA/MINNESOTA/NEBRASKA OR OVER WESTERN/NORTHWESTERN IOWA...AND HOW FAR EAST/SOUTHEAST THEY WILL REMAIN SEVERE AS THEY MOVE QUICKLY ACROSS THE STATE. SPC PRODUCTS HANDLE THE THREAT WELL AND WILL BE CLOSELY MONITORED TODAY AND TOMORROW. AFTER THE FRONT AND ASSOCIATED STORMS BLOW THROUGH ON SATURDAY NIGHT WE WILL ONCE AGAIN SEE MOSTLY CLEAR...COOL...AND BREEZY WEATHER FROM SUNDAY INTO EARLY NEXT WEEK. BY MONDAY THE 500 MB PATTERN WILL FEATURE A DEEPENING GYRE OVER THE GREAT LAKES REGION...THAT BEING THE SYSTEM THAT AFFECTED US ON SATURDAY/SATURDAY NIGHT...WITH A DEVELOPING RIDGE OVER THE FOUR CORNERS REGION. INITIALLY THIS WILL PLACE IOWA BENEATH PERSISTENT NORTHWEST FLOW RESULTING IN A VERY SLOW WARMING TREND. BY MIDWEEK AS THE EASTERN GYRE DEPARTS THE WESTERN RIDGE WILL BUILD FURTHER AND APPROACH OUR AREA...BUT MOST OF THE HEAT BUBBLE SHOULD REMAIN WEST/SOUTHWEST OF IOWA THROUGH AT LEAST WEDNESDAY. THERE ARE CONSISTENT INDICATIONS THAT A SHORTWAVE WILL OVERTOP THE 500 MB RIDGE SOMETIME AROUND THURSDAY...POSSIBLY PROVIDING US WITH ANOTHER CHANCE FOR RAIN BUT MORE IMPORTANTLY SHUNTING THE RIDGE SOUTHWARD FOR A DAY OR TWO. BEYOND THIS...LOOKING TOWARD THE NEXT WEEKEND OR SO...IT REMAINS UNCERTAIN WHETHER THE LARGE RIDGE WILL BE ABLE TO BUILD UP OVER THE MIDWEST OR WILL REMAIN JUST TO OUR SOUTHWEST. THIS WILL DETERMINE WHETHER WE GET ONE LAST BLAST OF SUMMER HEAT OR NOT. && .AVIATION...21/12Z ISSUED AT 648 AM CDT FRI AUG 21 2015 VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. ONLY CONCERN IS WITH GUSTY WINDS LATE THIS MORNING INTO THE AFTERNOON...AND SUSTAINED WINDS ARE EXPECTED TO PERSIST TONIGHT INTO TOMORROW MORNING WITH A DECENT PRESSURE GRADIENT ACROSS THE STATE. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...LEE AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
545 AM MDT FRI AUG 21 2015 .SHORT TERM...(TODAY THROUGH SUNDAY NIGHT) ISSUED AT 330 AM MDT FRI AUG 21 2015 FORECAST CONCERNS WILL BE THUNDERSTORM CHANCES INTO THE BEGINNING OF THE WEEKEND AND HOW COOL TO MAKE IT SATURDAY NIGHT INTO SUNDAY NIGHT. SATELLITE SHOWING AN AMPLIFIED/BLOCKY OVER THE PACIFIC. THIS TRANSITIONS TO A BROAD TROUGH/WESTERLY ALOFT OVER MOST OF THE COUNTRY. STRONG SYSTEM DIGGING INTO SOUTHWEST CANADA WITH SEVERAL SHORTWAVE TROUGHS EMBEDDED IN THE WESTERLY FLOW. AT JET LEVEL...MODELS DID WELL. AT MID LEVELS...THE GFS/CANADIAN AND THE UKMET WERE DOING A LITTLE BETTER THAN THE ECMWF. THE SREF AND ESPECIALLY THE NAM WERE NOT DOING WELL. THE GFS WAS DOING A LITTLE BETTER THAN THE ECMWF WITH THE LOW LEVEL WIND FIELD. ALL MODELS INITIALIZED WELL ON THE LOW LEVEL THERMAL FIELD DIFFICULT AND UNCERTAIN PRECIPITATION FORECAST...ESPECIALLY THROUGH THIS EVENING. CONFIDENCE IS BELOW AVERAGE FOR THE PRECIPITATION FORECAST. TODAY/TONIGHT...WILL HAVE TO KEEP AN EYE ON ANY LATE NIGHT/EARLY MORNING DEVELOPMENT NEAR THE BOUNDARY JUST TO THE NORTH OF OUR AREA. MODELS HAVE BEEN HINTING AT IT AND WILL CONTINUE TO MONITOR. FOR YESTERDAYS THUNDERSTORMS...JUST ENOUGH MOISTURE ALONG A BOUNDARY WITH A WEAK SHORTWAVE TROUGH WAS ABLE TO SPARK ISOLATED THUNDERSTORMS OVER AND NEAR THE NORTHEAST PORTION OF THE AREA. NOT TOO DIFFERENT A SETUP FOR TODAY FROM YESTERDAY. AGAIN WHAT MAKES FORECAST UNCERTAIN IS THE MOISTURE AVAILABILITY...ESPECIALLY ABOVE THE LOW LEVELS...WHERE DOES THE SURFACE TROUGH SETUP AND THE WEAK/COMPLICATED MID LEVEL FORCING INVOLVED. MODELS HAVE THE BOUNDARY PRETTY CLOSE BUT A LITTLE FURTHER WEST THAN WHAT WAS SHOWN YESTERDAY. 700 MB SHORTWAVE EJECTS INTO THE PLAINS THIS AFTERNOON AND IT LOOKS TO BE IN TWO PIECES. ONE PORTION GOES ACROSS THE NORTH AND IS THE SLOWER OF THE TWO SHORTWAVE TROUGHS. THE SECOND ONE GOES ACROSS TO OUR SOUTH AND BRUSHES THE SOUTHERN PORTION OF THE AREA. THERE IS WEAK FORCING IN BETWEEN. ALSO THE MODELS DIFFER ON HOW FAR EAST DURING THE DAY THEY MOVE THESE SHORTWAVE TROUGHS. CONVECTIVE ALLOWING MODELS ARE HAVING A DIFFICULT WITH ALL THIS. THE ARW HAS LITTLE TO NOTHING. THE HRRR AND ESPECIALLY THE NMM DEVELOP ROBUST CONVECTION OVER THE WESTERN PORTION OF THE AREA THIS AFTERNOON CLOSE TO THE SURFACE TROUGH. THE 00Z NAM DID NOT INDICATE ANYTHING BUT NOW THE 06Z NAM IS MATCHING UP WITH THE ABOVE TWO MODELS. THE 00Z ECMWF EXPLODES CONVECTION OVER THE NORTHERN PORTION OF THE AREA. ALL THIS TIME A RATHER STOUT EML LIES OVER THE AREA. AFTER LOOKING AT THIS AND COLLABORATION...PULLED THE INITIATION A LITTLE FURTHER WEST THAN BEFORE. THE PROBLEM THEN BECOMES HOW FAR EAST TO TAKE THIS ACTIVITY. THE HRRR TAKES IT FURTHER EAST WHILE THE REST OF THE OUTPUT THAT DID DEVELOP SOMETHING JUST KEEPS IT OVER THE WEST AS IT EITHER DISSIPATES THE THUNDERSTORMS OR MOVES THEM OF THE AREA TO THE NORTH OR SOUTH. SO DID LOWER POPS A LITTLE DUE TO THIS. IT DOES LOOK LIKE THE THUNDERSTORMS END BY 06Z. HOWEVER ELEVATED STORMS/REDEVELOPMENT WILL NEED TO BE LOOKED AT AGAIN TO A LOW LEVEL JET AND DECENT WARM AIR ADVECTION PATTERN ALOFT AHEAD OF ANOTHER SHORTWAVE TROUGH. FOR THIS AFTERNOON AND EVENINGS CONVECTION...IF STORMS DEVELOP...IT WILL BE POSSIBLE THAT THESE WILL BECOME SEVERE DUE TO THE INSTABILITY AND LAPSE RATES INVOLVED. NO MATTER IF STORMS DEVELOP OR NOT...BOUNDARY LAYER MOISTURE INCREASES AND AT THE VERY LEAST A LOT OF STRATUS WILL DEVELOP WITH SOME PATCHY FOG INVOLVED. PRESSURE FALLS AND GRADIENT SUPPORT NEAR BREEZY OR BREEZY CONDITIONS. GUIDANCE HAS BEEN RUNNING COOL ON MAXES HERE THE LAST FEW DAYS. THE GFS/MAV HAS BEEN DOING THE BEST AND HAVE RAISED THE MAXES SOME. SATURDAY/SATURDAY NIGHT...PATCHY FOG ENDS BY MID MORNING WITH THE STRATUS LASTING A LITTLE LONGER. THERE ARE STILL DIFFERENCES IN HOW FAST THE MODELS BRING IN THE COLD FRONT. THE NAM IS THE SLOWEST FOLLOWED BY SREF. THE GFS/ECMWF/CANADIAN ARE THE FASTEST. ROUGHLY IT LOOKS LIKE THE FRONT IS THROUGH THE NORTHWEST HALF OF THE AREA BY LATE MORNING. THE FRONT THEN LOOKS TO MOVE ACROSS THE REST OF THE AREA BY LATE AFTERNOON OR EARLY EVENING. THE CHANCE OF THUNDERSTORMS WILL BE OVER THE SOUTHEAST PORTION OF THE AREA IN ADVANCE OF THIS FRONT. CONTINUED THE LOW CHANCE POPS IN THIS AREA. FRONT AND ASSOCIATED FORCING EXIT THE AREA EARLY IN THE EVENING AND SO PRECIPITATION CUTS OFF RATHER FAST. WINDS BEHIND THE FRONT COULD GET WINDY AND THE DAY SHIFT WILL NEED TO LOOK AT RAISING THE WINDS EVEN MORE. DESPITE SIMILAR TIMING TO YESTERDAYS OUTPUT...MODELS HAVE RAISED HIGH TEMPERATURES FOR THE DAY. THE GFS...CANADIAN AND THE NAM ARE IN DECENT AGREEMENT ON THIS. IT SEEMS THAT THE COLDER AIR DOES LAG SLIGHTLY BEHIND THE FRONT. DID RAISE MAXES A LITTLE BUT THEY MAY NEED TO BE RAISED EVEN MORE IN SOUTHERN LOCATIONS. WINDS STAY UP ENOUGH TONIGHT THAT TEMPERATURES SHOULD NOT DROP LIKE A ROCK. IF THE WINDS LET UP QUICKER...GOOD RADIATIONAL CONDITIONS WOULD BE IN PLACE AND A LOWERING OF THE MINS WOULD BE NEEDED. SUNDAY/SUNDAY NIGHT...DRY PERIOD WITH POST FRONTAL COOL AIR MASS IN PLACE. NEW GUIDANCE FOR TEMPERATURES VERY SIMILAR TO WHAT WAS IN THERE FOR MAXES AND MADE ONLY SLIGHT ADJUSTMENTS. ONCE AGAIN FOR THE MINS...IF WINDS END UP BEING LESS THAN CURRENTLY PREDICTED ADDITIONAL COOLING WILL BE NEEDED. .LONG TERM...(MONDAY THROUGH THURSDAY) ISSUED AT 330 AM MDT FRI AUG 21 2015 THE EXTENDED PERIOD LOOKS TO BE MOSTLY DRY ALONG WITH NEAR TO ABOVE NORMAL TEMPERATURES FOR THE AREA AS RIDGING INFLUENCES THE FORECAST. ON MONDAY...AN UPPER LEVEL RIDGE CONTINUES TO BUILD INTO THE PLAINS FOLLOWING THE SYSTEM PREDICTED TO IMPACT THE REGION THIS WEEKEND. THE RIDGE AMPLIFIES AND MOVES EAST EARLY NEXT WEEK...WITH ITS AXIS NEARING THE PLAINS ON WEDNESDAY. DRY CONDITIONS ARE EXPECTED DURING THIS TIME FRAME. MOISTURE RETURNS TO THE AREA WEDNESDAY AND THURSDAY AS A SHORTWAVE MOVES ALONG THE PERSISTENT RIDGE. THIS DISTURBANCE LOOKS TO GENERATE SHOWER AND THUNDERSTORM CHANCES WEDNESDAY NIGHT AND THURSDAY FOR PORTIONS OF THE REGION. AFTER SUNDAYS COOL DOWN...TEMPERATURES ARE EXPECTED TO QUICKLY REBOUND IN THE EXTENDED PERIOD WITH HIGHS IN THE UPPER 80S TO LOW 90S AND LOWS IN THE UPPER 50S TO UPPER 60S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 540 AM MDT FRI AUG 21 2015 AT THIS TIME VFR CONDITIONS ARE EXPECTED AT BOTH SITES. SOUTHERLY WINDS WILL INCREASE THIS MORNING AND BECOME GUSTY. THESE GUSTY WINDS WILL LAST WELL INTO THE NIGHT WITH SUSTAINED SPEEDS OF 14 TO 17 KNOTS WITH GUSTS 22 TO 25 KNOTS. THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND EVENING BUT MODEL DIFFERENCES ON TIME AND AREA OF INITIATION MAKE THINGS A LITTLE UNCERTAIN. AT THIS TIME ONLY FEEL COMFORTABLE ENOUGH TO PUT IN A VCTS AT BOTH SITES WITH KGLD STARTING AT 21Z AND KMCK AT 00Z. THUNDERSTORMS ARE EXPECTED TO BE DONE BY 03Z. LATER IN THE NIGHT SOME FOG IS EXPECTED VISIBILITIES STAYING ABOVE MVFR. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...BULLER LONG TERM...JBH AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
954 AM CDT FRI AUG 21 2015 .DISCUSSION... NUM SHRA/TSRA BEGINNING TO MOVE ASHORE SE TX/SW LA IN ASSOCIATION WITH THE NEXT UPPER LEVEL IMPULSE MOVING NE ACROSS THE TX COAST THIS MORNING. THUS...HAD TO BUMP UP POPS AND QPF SIGNIFICANTLY THIS MORNING...CLOSE TO HRRR GUIDANCE WHICH HAS A GOOD HANDLE ON THIS SITUATION. ALSO INCLUDED HEAVY RAINFALL POSSIBLE AS THESE WILL BE SOMEWHAT SLOWER MOVING. WITH THE INCREASED CLOUD COVER...AGREE WITH HRRR AND LOWERED TEMPS ACROSS SE TX/SW LA. OTHERWISE...BUMPED UP WINDS A BIT TO 10-15 KTS ACROSS THE COASTAL WATERS THIS MORNING AS THIS SYSTEM MOVES ACROSS THE REGION. THATS ABOUT IT. UPDATES ALREADY OUT. DML && .PREV DISCUSSION... /ISSUED 716 AM CDT FRI AUG 21 2015/ DISCUSSION... FOR THE 12Z TAF PACKAGE. AVIATION... QUIETER NIGHT AND MORNING VERSUS THE PREVIOUS COUPLE OF DAYS...THOUGH CONVECTIVE ACTIVITY HAS BEEN ON THE INCREASE OVER THE COASTAL WATERS FOR THE PAST COUPLE OF HRS...ESPECIALLY OFF THE SE TX/SW LA COASTS. LATEST HIGH RESOLUTION MODEL DATA DEPICTS THE WELL DEFINED SHORTWAVE OVER THE MIDDLE TX COAST...AND ITS ASSOCIATED CONVECTION...LIFTING NE THROUGH THE AREA LATER THIS MORNING INTO THE AFTERNOON. VCTS WAS INSERTED AT EACH SITE BASED ON THIS THINKING. RECENT PLUNGE IN VSBY AT KAEX IS EXPECTED TO BE SHORT LIVED...PERHAPS AN HR OR SO. WILL CONTINUE TO MONITOR FOR A POSSIBLE AMD. VFR EXPECTED TO PREVAIL OUTSIDE OF CONVECTION...AND BY THIS EVENING AS ACTIVITY LIFTS NE OF THE AREA. 13 PREV DISCUSSION... /ISSUED 452 AM CDT FRI AUG 21 2015/ SYNOPSIS... A NEARLY STATIONARY W-E ORIENTED SFC FRONT EXTENDS FM NE TX ACRS NRN LA INTO CNTL MS. THE FRONT HAS BECOME A LITTLE MORE DIFFUSE THE PAST SEVERAL HOURS...AS DEWPOINTS ALONG AND SOUTH OF THE FRONTAL ZONE ARE IN THE LOWER TO MIDDLE 70S WITH COOLER AND DRIER AIR LOCATED WELL BEHIND THE BOUNDARY ACRS NRN/CNTL ARK AND FAR N MS. THE LATEST WV IMAGERY AND UA ANALYSIS SHOWS MOISTURE ALOFT BEING FUNNELED OVER THE REGION ON SWLY FLOW BETWEEN A TROF/WEAKNESS OVER THE SRN PLAINS AND AN UPR RIDGE ACRS THE GULF OF MEXICO. A LITTLE LESS CONVECTIVE ACTIVITY SO FAR TODAY THAN THE PAST COUPLE OF MORNINGS...ALTHOUGH REGIONAL RADAR MOSAIC SHOWS SCT SHOWERS AND A FEW TSTMS DEVELOPING OFF THE UPR TX COAST AND OVER GALVESTON BAY WITH MORE ISOLATED ACTIVITY OVER OUR COASTAL WATERS ZONES. FURTHER INLAND...A BAND OF LT TO MDT RAIN WAS LOCATED NEAR THE FRONTAL BOUNDARY...FM JUST NORTH OF THE LAKES REGION OF SE TX INTO PORTIONS OF WRN LA. DISCUSSION... THE FRONT WILL GRADUALLY WEAKEN AS IT LIFTS BACK NORTH LATER TODAY. HOWEVER...ABUNDANT MOISTURE REMAINS OVER THE AREA AND WITH THE LINGERING DISTURBANCE OR WEAKNESS ALOFT...EXPECT SCT CONVECTION TO AGAIN DEVELOP TODAY. THIS ACTIVITY IS EXPECTED TO BE MORE DIURNALLY DRIVEN...WITH THE SEABREEZE BOUNDARY AND THE DISSIPATING FRONT FOCUSING CONVECTIVE DEVELOPMENT AS DAYTIME HEATING GETS UNDERWAY. PRECIP WATER VALUES WILL REMAIN NEAR 2 INCHES...AND THIS SHOULD AGAIN ALLOW TSTMS TO BE EFFICIENT RAINFALL PRODUCERS WITH HIGH RAIN RATES AT TIMES. CLOUDY SKIES ON THURSDAY HELPED TO KEEP TEMPERATURES IN THE 80S...WITH SOME LOCATIONS ONLY REACHING THE LOWER 80S. WHILE THIS MAY BE THE CASE AGAIN TODAY...THINK CLOUD AND CONVECTIVE COVERAGE WILL BE A LITTLE LESS AND OCCASIONAL PEEKS OF SUN SHOULD ALLOW TEMPERATURES TO RISE TO NEAR 90 IN THE AFTN. MEANWHILE...THE WEAKNESS ALOFT WILL MORE OR LESS LINGER OVER THE REGION THROUGH THE WEEKEND EVEN AS THE HIGH OVER THE ERN GULF BEGINS TO BUILD WEST. THERE WILL STILL BE A DAILY CHC FOR SHOWERS OR STORMS SATURDAY AND SUNDAY BUT COVERAGE WILL BE LOWER AS SLIGHTLY DRIER AIR BEGINS TO WORK INTO THE REGION. WITH LESS CONVECTION AND CLOUDS...AFTN TEMPERATURES WILL BEGIN A WARMING TREND. BY EARLY NEXT WEEK...THE HIGH WILL RETROGRADE FURTHER WEST AS A SHORTWAVE TROF DIGS OVER THE ERN STATES...WITH THE SYSTEM GRADUALLY AMPLIFYING OVER THE CONUS. THIS WILL LEAD TO A DEEPENING NLY FLOW THAT WILL PUSH A SFC FRONT INTO THE AREA BY TUESDAY. RAIN CHCS WILL BUMP BACK UP IN ADVANCE OF THE FRONT MONDAY INTO TUESDAY. GLOBAL MODELS ARE IN GENERAL AGREEMENT REGARDING THE DEVELOPMENT OF THIS AMPLIFIED SYSTEM AND ASSOCIATED SFC FROPA...AND KEEPING THE AREA UNDER A NLY FLOW ALOFT THROUGH THE LATTER PART OF THE WEEK. SHOULD THIS SCENARIO PAN OUT...DRIER MORE COMFORTABLE CONDITIONS CAN BE EXPECTED FROM WEDNESDAY THROUGH FRIDAY WITH SLIGHTLY BELOW NORMAL LOWS IN THE UPPER 60S TO LOWER 70S AND HIGHS NEAR NORMAL IN THE LOWER 90S. 24 MARINE... A LT TO OCCASIONALLY MDT ONSHORE FLOW AND LOW SEAS WILL PERSIST THROUGH EARLY NEXT WEEK AS HIGH PRES CONTINUES TO RIDGE OVER THE GULF. A LINGERING DISTURBANCE OVER THE REGION WILL ALLOW FOR SCT SHOWERS AND TSTMS TODAY...BUT RAIN CHCS WILL DECREASE OVER THE WEEKEND AS HIGH PRES BUILDS ALOFT. A FRONT WILL MOVE SOUTH INTO THE AREA BY LATE MONDAY INTO TUESDAY...BRINGING ANOTHER CHC FOR SHOWERS OR TSTMS. AT THIS TIME...MODEL GUIDANCE SHOWS THIS FRONT MOVING SOUTH OVER THE COASTAL WATERS ZONES...WITH OFFSHORE FLOW AND DRIER WEATHER POSSIBLE FOR THE MIDDLE AND LATTER PART OF NEXT WEEK. 24 && .PRELIMINARY POINT TEMPS/POPS... AEX 92 74 94 75 / 70 20 30 10 LCH 85 77 90 77 / 60 20 30 10 LFT 87 76 91 76 / 70 20 30 10 BPT 84 77 90 77 / 80 20 30 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$ PUBLIC...08
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
810 AM CDT FRI AUG 21 2015 ...SOUNDING DISCUSSION... WINDS THROUGHOUT THE ATMOSPHERE ARE FROM THE SOUTHWEST ALLOWING FOR MOISTURE TO REMAIN OVER THE AREA WITH A PRECIPITABLE WATER VALUE OVER 2 INCHES. A SURFACE INVERSION AND LIGHT WINDS HAVE ALLOWED FOR SOME FOG TO FORM WITH VISIBILITIES BEING REDUCED GENERALLY BETWEEN 5 TO 10 MILES WHERE IT HAS FORMED. GOOD BOUNDARY LAYER MIXING WILL OCCUR WITH MAINLY CLEAR SKIES THROUGH MID- MORNING ALLOWING THE INVERSION TO BE REMOVED. THE CONVECTIVE TEMPERATURE OF 86 SHOULD BE REACHED ACROSS MOST OF THE AREA AROUND NOON TODAY AND THE 12Z HRRR SHOWS CONVECTION INCREASING IN COVERAGE EARLY THIS AFTERNOON. 12Z BALLOON INFO: A ROUTINE FLIGHT THIS MORNING THAT LASTED 103 MINUTES. THE BALLOON REACHED A HEIGHT OF 21.5 MILES ABOVE THE GROUND BURSTING JUST EAST OF ABITA SPRINGS 10 MILES DOWNRANGE FROM THE OFFICE. ANSORGE && .PREV DISCUSSION... /ISSUED 340 AM CDT FRI AUG 21 2015/ SHORT TERM... COLD FRONT STALLED OVER SOUTHERN ARK THIS MORNING WILL BEGIN TO MOVE BACK TO THE NORTH LATER TODAY. THIS FRONT WILL BE REPLACED WITH A SECOND FRONT MOVING INTO THE SOUTHERN ARK AREA MONDAY. THIS SYSTEM WILL STALL FOR ABOUT 12 HOURS BEFORE MOVING SOUTHWARD ONCE AGAIN MON NIGHT. THE AERA OF SH/TS WILL BE DEVELOPING ALONG THE PREFRONTAL TROUGH THAT MOVES OUT AHEAD OF THE ACTUAL COLD FRONT. THIS WILL SEND A GOOD ROUND OF SH/TS THROUGH THE AREA LATE MONDAY AND POSSIBLY THROUGH MONDAY NIGHT. THE FRONT WILL BE ROUGHLY 10 TO 12 HOURS BEHIND THE PREFRONTAL TROUGH AND SHOULD MOVE THROUGH LATE TUESDAY. THIS WILL BE NOTICED AS DP TEMPS WILL DROP BACK INTO THE LOWER 60S. THIS IS STILL SEVERAL DAYS AWAY. BUT THE UPPER LONG WAVE TROUGH DROPS INTO THE AREA AS WHAT IS LEFT OF DANNY IS BEING PICKED UP BY IT. THIS SETS SOME HIGHER CONFIDENCE IN THIS FRONT MAKING IT THROUGH THE AREA SINCE THE MOVEMENT OF ONE AREA OF LARGE SCALE MASS MOVES NORTH SOMETHING EQUAL WILL NEED TO MOVE SOUTH OR VICE VERSA. THE ONLY OTHER THING TO WATCH FOR WITH THIS SCENARIO WILL BE THE POSSIBILITY OF SOME STRONG OR SEVERE TS ACTIVITY MONDAY EVENING. WILL FIND BETTER TIMING AND STRENGTH OF THIS SCENARIO WITH FUTURE FCASTS. LONG TERM... IF THE COLD FRONT MOVES THROUGH AND CLEARS THE AREA...WED THROUGH THE REMAINDER OF THE WEEK IS LOOKING FANTASTIC. AVIATION... VFR CONDITIONS WILL GENERALLY PREVAIL THROUGH THE PERIOD. MVFR CIGS MAY DEVELOP FOR A COUPLE HOURS NEAR DAYBREAK. WINDS WILL GENERALLY REMAIN LESS THAN 10 KTS...EXCEPT FOR IN THE VICINITY OF SHOWERS AND THUNDERSTORMS. SCATTERED CONVECTION IS EXPECTED TO DEVELOP THIS AFTERNOON AND TEMPO GROUPS HAVE BEEN INCLUDED AT MOST SITES DURING THE 18Z TO 22Z TIME FRAME. MARINE... GENERALLY TRANQUIL CONDITIONS WILL PREVAIL THROUGH THE PERIOD AS WINDS ARE EXPECTED TO REMAIN 10 KNOTS OR LESS WITH WAVES NO HIGHER THAN 2 FEET. ONLY REAL EXCEPTION WILL BE IN THE VICINITY OF SCATTERED SHOWERS AND THUNDERSTORMS...WHERE STRONGER WINDS AND ROUGHER SEAS WILL BE POSSIBLE. A WEAK FRONTAL BOUNDARY IS EXPECTED TO SLIDE THROUGH THE AREA AND RESULT IN PREVAILING OFFSHORE FLOW BY WEDNESDAY. DECISION SUPPORT... DSS CODE....GREEN. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...NONE. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE && .PRELIMINARY POINT TEMPS/POPS... MCB 89 73 94 74 / 60 20 40 10 BTR 92 74 94 75 / 60 20 40 10 ASD 90 75 91 76 / 60 20 40 10 MSY 90 77 91 77 / 50 20 40 10 GPT 90 78 90 78 / 50 20 30 10 PQL 90 77 90 77 / 50 20 30 10 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS GLASGOW MT
947 AM MDT FRI AUG 21 2015 .SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SUNDAY... MORNING UPDATE... CHANGE TO THE FORECAST FOR THIS MORNING WERE FOCUSED ON SPORADIC QPF BLOTCHES WHICH ARE SHOWING UP IN VARIOUS MODELS IN DIFFERENT PLACES ACROSS THE CWA. WITH THE STALLED FRONTAL BOUNDARY ISOLATED RAIN SHOWERS WILL BE POSSIBLE BUT PLACEMENT FOR THESE SHOWERS IS GENERALLY UNKNOWN. BEST GUESS WOULD BE FORMATIONS OVER THE CENTRAL MONTANA MOUNTAINS WERE LIGHT RAIN SHOWERS WOULD THEN WANDER IN TO THE WESTERN ZONES OF THE CWA... BUT THEN THE RAP AND HRRR BOTH SHOW A SHOWER FORMING OVER THE BIG SHEEP HILLS. SO EVEN EASTERN ZONES ARE NOT OUT OF THE QUESTION TO RECEIVE VERY LIGHT PRECIP THIS AFTERNOON. WITH A SLIGHT REWORKING OF WIND GRIDS THIS AFTERNOON ALSO SAW THE WINDS AHEAD OF THE FRONT FALLING OFF TO LESS THAN 10 KTS AT TIMES. HOWEVER... DIRECTLY BEHIND THE FRONT WINDS RAMP UP FAST AND STRONG. SO... HAVE NOT TOUCHED ANY OF THE HAZARD PRODUCTS IN ANTICIPATION OF THE KICK UP OVERNIGHT. GAH PREVIOUS SHORT TERM DISCUSSION... UPPER LEVEL TROUGH CURRENTLY MOVING ACROSS BRITISH COLUMBIA WILL MOVE ACROSS EASTERN MONTANA TONIGHT AND SATURDAY. TO THE EAST... LOW PRESSURE SYSTEM WILL DEVELOP OVER EASTERN MONTANA TODAY AND MOVE EAST INTO NORTH DAKOTA THIS EVENING. THIS WILL DRAG A COLD FRONT ACROSS EASTERN MONTANA THIS AFTERNOON AND EARLY EVENING. LOOK FOR VERY WARM TEMPERATURES AND LOW RH AHEAD OF THE FRONT TODAY. WITH GUSTY WEST WINDS EXPECTED BEHIND THE FRONT IN THE WEST THIS AFTERNOON... WILL KEEP RED FLAG WARNING IN EFFECT. SEE FIRE WEATHER DISCUSSION FOR MORE INFORMATION. THE DRY AIR MASS WILL ALSO BRING A DRY FRONTAL PASSAGE FOR THE MOST PART. UNSTABLE AIR MASS IN THE EAST MAY ALLOW FOR A SLIGHT CHANCE OF THUNDERSTORMS THIS AFTERNOON. A TIGHT SURFACE GRADIENT WILL DEVELOP THIS EVENING BETWEEN THE LOW PRESSURE SYSTEM IN NORTH DAKOTA AND A SURFACE HIGH IN ALBERTA. THIS WILL ALLOW GUSTY NORTHWEST WINDS TO DEVELOP. WILL ISSUE A LAKE WIND ADVISORY FOR FORT PECK LAKE STARTING AT 21Z (3 PM MDT). MOISTURE WITH THIS SYSTEM WILL BE PRIMARILY IN THE UPPER TROUGH. WILL INCREASE THE CHANCES OF SHOWERS FROM WEST TO EAST TONIGHT AS THE UPPER TROUGH MOVES INTO THE AREA. AIR MASS MAY BE UNSTABLE ENOUGH FOR AN ISOLATED THUNDERSTORM THIS EVENING. THE UPPER TROUGH MOVES INTO THE DAKOTAS SATURDAY AFTERNOON WHILE THE SURFACE LOW MOVES INTO MINNESOTA. MOISTURE ASSOCIATED WITH THE UPPER TROUGH WILL BRING RAIN SHOWERS TO MOST OF THE FORECAST AREA DURING THE MORNING AND IN THE EAST IN THE AFTERNOON. TIGHT SURFACE GRADIENT REMAINS SO IT WILL BE WINDY WITH NW WINDS 20 TO 35 MPH. MUCH COLDER AIR MASS WILL BE IN PLACE WITH HIGHS 55 TO 65 OR ABOUT 30 DEGREES COLDER THAN TODAY. HIGH PRESSURE BUILDS INTO EASTERN MONTANA SATURDAY NIGHT DIMINISHING THE WINDS AND CLEARING THE SKIES. WITH COLDER AIR MASS IN PLACE...SOME AREAS WILL HAVE LOWS IN THE 30S. HIGH PRESSURE REMAINS OVER EASTERN MONTANA ON SUNDAYS WITH MOSTLY SUNNY SKIES AND WARMER TEMPERATURES. FORRESTER .LONG TERM...SUNDAY NIGHT THROUGH FRIDAY... THE EXTENDED PERIOD BEGINS SUNDAY NIGHT WITH AN UPPER LEVEL RIDGE IN PLACE OVER THE WEST. THE RIDGE AXIS WILL BE ALIGNED WITH THE NORTHERN ROCKIES INITIALLY. THE AXIS MOVES OVER NORTHEAST MONTANA AROUND MONDAY NIGHT...WHICH WILL ALLOW DESERT AIR TO CREEP NORTH INTO THE LOCAL REGION. THIS WILL SEND TEMPERATURES ABOVE NORMAL BEGINNING TUESDAY. BY WEDNESDAY A SHORT-WAVE DISTURBANCE RIDES THE RIDGE NORTH INTO WYOMING...UNDER-CUTTING MONTANA. MODELS SHOW SOME LOCAL INSTABILITY DEVELOPING LATE WEDNESDAY INTO THURSDAY. THEN FRIDAY ANOTHER EMBEDDED BUT WEAKER DISTURBANCE COULD CONTINUE THE CHANCE FOR THUNDERSTORMS AND RAIN SHOWERS. OVERALL...EXPECT INITIALLY NORMAL TEMPERATURES THAT INCREASE TO ABOVE AVERAGE FOR THE MOST OF THE PERIOD. ALSO EXPECT DRY CONDITIONS UNTIL MID-WEEK. SCT && .AVIATION... FLIGHT CATEGORY: VFR INITIALLY... MVFR/IFR BY THE END OF THE CYCLE. SYNOPSIS: A SURFACE TROUGH AND STALLED FRONT WILL BRING ABOUT VEERING WIND SHIFTS. ISOLATED SHOWERS COULD ALSO FORM ON THESE BOUNDARIES THIS AFTERNOON BUT CHANCE ARE TOO LOW TO INCLUDE IN THE TAFS. STORM SYSTEM: A COMPACT STORM SYSTEM WILL MOVE THROUGH THE REGION TONIGHT BRINGING RAIN SHOWERS AND SOME THUNDERSTORMS...ALONG WITH GUSTY NORTHWEST WIND. EXPECT CEILINGS AND VISIBILITY CONDITIONS TO BECOME MVFR/IFR BY OR AFTER 12Z. CONDITIONS WILL BEGIN TO IMPROVE SATURDAY NIGHT. HAZE: CLOUDS WILL BE MIXED WITH SMOKE FROM WILD FIRES IN THE WEST...PRODUCING A HAZY OVERCAST AT TIMES. WINDS: FROM THE EAST AND SOUTHEAST AT LESS THAN 10 KTS THIS MORNING... VEERING TO THE WEST THIS AFTERNOON AND INCREASING TO 10 TO 15 KTS.... THEN FURTHER VEERING TO THE NORTHWEST OVERNIGHT AND INCREASING TO 20-30KT WHEN A STRONG COLD FRONT MOVES THROUGH THE AREA. GAH/SCT && .GLASGOW WATCHES/WARNINGS/ADVISORIES... LAKE WIND ADVISORY FROM 3 PM THIS AFTERNOON TO 9 PM MDT SATURDAY FOR FORT PECK LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY...GARFIELD...MCCONE...PETROLEUM. RED FLAG WARNING FROM NOON TODAY TO MIDNIGHT TONIGHT FOR FIRE WEATHER ZONES 134...135...136...AND 137. && $$ WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1020 AM EDT FRI AUG 21 2015 .SYNOPSIS... A COLD FRONT WILL WAVER ACROSS THE AREA TODAY...BRINGING A RENEWED CHANCE FOR SHOWERS AND THUNDERSTORMS. MOSTLY SUNNY AND SEASONABLE WEATHER WILL FOLLOW FOR THE WEEKEND BEHIND THIS FRONT. WARMER AND MORE HUMID AIR WILL RETURN NEXT WEEK AHEAD OF A COLD FRONT WHICH WILL APPROACH ON TUESDAY...AND THEN STALL ACROSS THE AREA THROUGH THURSDAY BRINGING COOLER AND UNSETTLED CONDITIONS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM FRIDAY...HARD TO PICK OUT THE FRONT THIS MORNING. BASED ON WIND DIRECTIONS IT APPEARS TO BE WAVERING ACROSS THE AREA AND MAY BE JUST OFFSHORE AT THIS TIME. ANALYSIS OF MORNING SOUNDING DATA SHOWS A VERY MOIST ATMOSPHERE WITH DEWPOINTS WELL IN THE 70S AND P/W VALUES APPROACHING 2.25 INCHES. NAM IS STILL LIKING SCATTERED CONVECTION THIS AFTERNOON...ESPECIALLY NEAR THE COAST...ALTHOUGH THE HRRR CONTINUES IN A MORE MODEST VEIN...WITH ISOLATED SEA-BREEZE CONVECTION FIRING UP THIS AFTERNOON. KEEPING PRESENT CHANCE POPS IN PLACE AS WITH SUCH A MOIST COLUMN IT WILL NOT TAKE MUCH TO KICK OFF CONVECTION. PREVIOUS DISCUSSION FOLLOWS: DESPITE GREAT MODEL-TO-MODEL CONSISTENCY 24 HOURS AGO THE COLD FRONT IS LAGGING THOSE PROGS BY NEARLY 100 MILES THIS MORNING. AT 6 AM THE FRONT APPEARS TO LIE ROUGHLY ALONG A LINE FROM ELIZABETHTOWN AND WHITEVILLE TO MYRTLE BEACH AND GEORGETOWN. THIS IS ANALYZED MORE BY PRESSURE THAN WIND SINCE WINDS ARE NEARLY CALM ON EITHER SIDE OF THE BOUNDARY. THE FRONT SHOULD CROSS THE NORTH CAROLINA BEACHES IN THE NEXT 1-2 HOURS...BUT WITH LITTLE WIND BEHIND THE FRONT THERE WILL BE NO SIGNIFICANT AIRMASS CHANGE. TEMPERATURES RISING INTO THE LOWER 90S INLAND THIS AFTERNOON SHOULD TRIGGER A SEABREEZE WHICH WILL MOVE THE EFFECTIVE LOCATION OF THE FRONT BACK INLAND DUE TO DEVELOPING ONSHORE WINDS ALONG THE COAST. WITH DEWPOINTS HOLDING IN THE LOWER 70S SURFACE-BASED INSTABILITY SHOULD GROW TO 1000-2000 J/KG THIS AFTERNOON. SYNOPTIC AND FINE- SCALE MODELS ALL SHOW THE POTENTIAL FOR AT LEAST SCATTERED SHOWERS AND STORMS THIS AFTERNOON...MOST NUMEROUS NEAR THE COAST WHERE SEABREEZE-ENHANCED CONVERGENCE WILL ASSIST THE GROWING CUMULUS CLOUDS. FORECAST POPS RANGE FROM 20 PERCENT INLAND TO 30-40 PERCENT ON THE COAST. LIGHT TROPOSPHERIC WINDS MEAN ANY CONVECTION WILL LIKELY BE DISORGANIZED PULSE-TYPE WITH NO SIGNIFICANT POTENTIAL FOR SEVERE WEATHER. DAYTIME CLOUDS WILL BE SLOW TO CLEAR TONIGHT ESPECIALLY ACROSS SOUTH CAROLINA WHERE A MID-LEVEL DISTURBANCE IS PROGGED TO MOVE IN FROM THE WEST DURING THE EVENING HOURS. THIS SHOULD SPREAD MID-LEVEL CLOUDS EASTWARD TOWARD THE COAST. A SMALL CHANCE OF SHOWERS AND STORMS WILL BE MAINTAINED OVERNIGHT ACROSS THE PEE DEE REGION DUE TO THE MOISTURE ADVECTING EASTWARD...AND OVERNIGHT LOWS HAVE BEEN ADJUSTED UPWARD DUE TO LESS RADIATIONAL COOLING EXPECTED. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...A BEAUTIFUL WKND IN STORE AS A COLD FRONT WILL BE WELL SOUTH OF THE AREA...LEAVING DRYING AND MOSTLY SUNNY CONDITIONS FOR SATURDAY AND SUNDAY. SATURDAY STILL HAS A CHANCE FOR SOME ISOLATED SHOWERS/TSTMS ACROSS THE SOUTHERN TIER OF ZONES WHERE PWATS WILL BE HIGHER AND THE FRONT WILL STILL BE IN THE VICINITY...POTENTIALLY INTERACTING WITH A WEAK SHORTWAVE MOVING IN FROM THE MIDLANDS OF SC...BUT NOT EXPECTING WIDESPREAD OR HEAVY CONVECTION...AND INTENSITY/COVERAGE WILL DECREASE THROUGH THE AFTN/EVE ON THE DRY ADVECTION. SUNDAY STILL SHAPING UP TO BE A GORGEOUS DAY...ALTHOUGH FLOW IS PROGGED TO RETURN TO THE SW EARLIER THAN PREVIOUSLY. THIS WILL CAUSE TEMPS TO BE WARMER...ALONG WITH SLIGHTLY HIGHER HUMIDITY THAN PREVIOUSLY FORECAST...BUT STILL EXPECT BRIGHT SUNSHINE AND A GREAT LATE- AUGUST DAY. TEMPS SATURDAY WILL BE AROUND SEASONABLE LEVELS AS COOL ADVECTION IS LACKING BEHIND THE FRONT. EXPECT HIGHS AROUND 87 FAR NW TO ABOUT 90 ALONG THE SOUTHERN TIER. MAX TEMPS ON SUNDAY WILL BE ABOUT 1-3 DEGREES WARMER EVERYWHERE. SUB-CLIMO MINS SATURDAY NIGHT THANKS TO THE DRY COLUMN...AND LOWS WILL DROP INTO THE REFRESHING CATEGORY...DROPPING INTO THE MID 60S WELL NW TO AROUND 70 AT THE COAST. MORE TYPICAL MINS SUNDAY NIGHT WITH LOWS A DEGREE OR TWO EITHER SIDE OF 70. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 AM FRIDAY...MID-LEVEL FLOW TO BECOME ANOMALOUSLY AMPLIFIED FOR AUGUST MUCH OF THE UPCOMING WEEK AS A LARGE TROUGH DEVELOPS ACROSS THE EAST WITH A BIG RIDGE BLOSSOMING OVER THE MTN WEST. ALTHOUGH MONDAY WILL FEATURE WARM TEMPS...POSSIBLY ABOVE NORMAL...WITH TYPICAL SUMMERTIME CONVECTION CHANCES...THIS IS LOOKING TO BE THE ONE ABOVE-NORMAL DAY OF THE PERIOD. THEREAFTER A COLD FRONT DROPS INTO THE CAROLINAS AND STALLS THROUGH MID-WEEK BEFORE FINALLY GETTING PUSHED SOUTH LATE WED INTO THU. THIS WILL CREATE AN EXTENDED PERIOD OF UNSETTLED WEATHER WITH GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS...ALONG WITH SUB-CLIMO TEMPS THANKS TO LOWERED THICKNESSES WITHIN THE TROUGH COMBINING WITH CLOUDS AND PRECIP. HARD TO SAY THE ENTIRE TUE-THU PERIOD WILL BE WET AND CLOUDY...BUT AT LEAST A GOOD PORTION OF EACH DAY LOOKS TO BE UNSETTLED WITH HIGHS SLIGHTLY BELOW CLIMO AND LOWS SLIGHTLY ABOVE AS DIURNAL RANGES BECOME COMPRESSED && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... AS OF 12Z...COLD FRONT PUSHING SOUTH THROUGH THE REGION AT THIS TIME. NO WEATHER ASSOCIATED WITH IT...JUST A WIND SHIFT TO THE NORTHWEST. THE HRRR MODEL HAS ISOLATED CONVECTION POPPING UP THIS AFTERNOON...BUT THAT IS A BIT OF A STRETCH AS THERE WILL NOT BE MUCH MOISTURE TO WORK WITH. WINDS CONTINUE TO VEER TO THE NORTHEAST BY AFTERNOON. LIGHT WINDS OVERNIGHT WITH LITTLE OR NO FOG EXPECTED. EXTENDED OUTLOOK...VFR WITH SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THE EXTENDED. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM FRIDAY...LIGHT AND VARIABLE WINDS WITH 2 FT WAVES OVER THE WATERS THIS MORNING AS A COLD FRONT WAVERS IN THE VICINITY. NO CHANGES TO THE FORECAST WITH THE LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS: SLOW-MOVING COLD FRONT SHOULD MOVE OFF THE BEACHES SHORTLY AFTER SUNRISE THIS MORNING. WESTERLY WINDS IN ADVANCE OF THE FRONT WILL VEER NORTHERLY LATER THIS MORNING BUT WITH NO INCREASE IN WIND SPEED. BY THIS AFTERNOON THE TYPICAL SEABREEZE CIRCULATION SHOULD OVERWHELM WHAT LITTLE WIND EXISTS BEHIND THE FRONT...WITH ONSHORE WINDS 10 KNOTS OR LESS EXPECTED ALL ALONG THE COAST. ENOUGH MOISTURE WILL REMAIN BEHIND THE FRONT THAT A FEW SHOWERS AND STORMS SHOULD FIRE UP DURING THE AFTERNOON HOURS NEAR THE COAST ALONG THE SEABREEZE BOUNDARY. STEERING WINDS ALOFT WILL BE LIGHT AND FROM THE NORTHWEST...PERHAPS PUSHING ANY OF THIS ISOLATED SHOWER/STORM ACTIVITY OUT ACROSS THE BEACHES AND INTO THE COASTAL WATERS. A NORTH-NORTHEAST WIND WILL GRADUALLY INCREASE LATE TONIGHT... REACHING 10-15 KNOTS LATE. SEAS SHOULD AVERAGE ONLY 2 FEET TODAY AND TONIGHT...PERHAPS BUILDING TO 3 FEET IN EXPOSED WATERS LATE. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...HIGH PRESSURE RIDGING DOWN THE COAST BEHIND A COLD FRONT WILL CREATE N/NE WINDS SATURDAY AND THE FIRST HALF OF SUNDAY. THE GRADIENT ASSOCIATED WITH THIS HIGH PRESSURE IS WEAK...SO WIND SPEEDS WILL BE 10 KTS OR LESS FROM THIS DIRECTION...AFTER A BRIEF SURGE UP TO 15 KTS EARLY SATURDAY. LATE SUNDAY...RETURN FLOW WILL BEGIN TO REDEVELOP AS WINDS SHIFT BACK AROUND TO THE SW BUT AT CONTINUED LIGHT SPEEDS. WAVE HEIGHTS WILL BE 2-3 FT EARLY DURING THE RESIDUAL NE SURGE...BUT FALL TO 1-2 FT SATURDAY AFTN AND PERSIST AT THESE AMPLITUDES THROUGH THE WIND SHIFT AND INTO THE END OF THE PERIOD LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 300 AM FRIDAY...SW WINDS AHEAD OF A COLD FRONT WILL INCREASE STEADILY DURING MONDAY...RISING UP TOWARDS 15 KTS LATE IN THE DAY. AS THE COLD FRONT APPROACHES WINDS WILL EASE A BIT MONDAY NIGHT...BUT THIS FRONT WILL LIKELY NOT REACH THE WATERS DURING TUESDAY AND INSTEAD STALL JUST INLAND. THIS WILL CONTINUE S/SW WINDS TUESDAY AT 10-15 KTS. SEAS WILL BE PRIMARILY 2-3 FT THROUGH THE PERIOD WITH A SE GROUND SWELL AND WEAK WIND WAVE COMPRISING THE SPECTRUM. LATE MONDAY AND INTO TUESDAY...SOME 12-SEC PERIOD SWELL FROM DISTANT TROPICAL SYSTEMS MAY ENTER THE SPECTRUM...BUT WILL BE AT 1 FT OR LESS IN AMPLITUDE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JDW NEAR TERM...REK/TRA SHORT TERM...JDW LONG TERM...JDW AVIATION...DL MARINE...REK/TRA/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
636 AM EDT FRI AUG 21 2015 .SYNOPSIS... A COLD FRONT WILL WAVER ACROSS THE AREA TODAY BRINGING A RENEWED CHANCE FOR SHOWERS AND THUNDERSTORMS. MOSTLY SUNNY AND SEASONABLE WEATHER WILL FOLLOW FOR THE WEEKEND BEHIND THIS FRONT. WARMER AND MORE HUMID AIR WILL RETURN NEXT WEEK AHEAD OF A COLD FRONT WHICH WILL APPROACH ON TUESDAY...AND THEN STALL ACROSS THE AREA THROUGH THURSDAY BRINGING COOLER AND UNSETTLED CONDITIONS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM FRIDAY...DESPITE GREAT MODEL-TO-MODEL CONSISTENCY 24 HOURS AGO THE COLD FRONT IS LAGGING THOSE PROGS BY NEARLY 100 MILES THIS MORNING. AT 6 AM THE FRONT APPEARS TO LIE ROUGHLY ALONG A LINE FROM ELIZABETHTOWN AND WHITEVILLE TO MYRTLE BEACH AND GEORGETOWN. THIS IS ANALYZED MORE BY PRESSURE THAN WIND SINCE WINDS ARE NEARLY CALM ON EITHER SIDE OF THE BOUNDARY. THE FRONT SHOULD CROSS THE NORTH CAROLINA BEACHES IN THE NEXT 1-2 HOURS...BUT WITH LITTLE WIND BEHIND THE FRONT THERE WILL BE NO SIGNIFICANT AIRMASS CHANGE. TEMPERATURES RISING INTO THE LOWER 90S INLAND THIS AFTERNOON SHOULD TRIGGER A SEABREEZE WHICH WILL MOVE THE EFFECTIVE LOCATION OF THE FRONT BACK INLAND DUE TO DEVELOPING ONSHORE WINDS ALONG THE COAST. WITH DEWPOINTS HOLDING IN THE LOWER 70S SURFACE-BASED INSTABILITY SHOULD GROW TO 1000-2000 J/KG THIS AFTERNOON. SYNOPTIC AND FINE- SCALE MODELS ALL SHOW THE POTENTIAL FOR AT LEAST SCATTERED SHOWERS AND STORMS THIS AFTERNOON...MOST NUMEROUS NEAR THE COAST WHERE SEABREEZE-ENHANCED CONVERGENCE WILL ASSIST THE GROWING CUMULUS CLOUDS. FORECAST POPS RANGE FROM 20 PERCENT INLAND TO 30-40 PERCENT ON THE COAST. LIGHT TROPOSPHERIC WINDS MEAN ANY CONVECTION WILL LIKELY BE DISORGANIZED PULSE-TYPE WITH NO SIGNIFICANT POTENTIAL FOR SEVERE WEATHER. DAYTIME CLOUDS WILL BE SLOW TO CLEAR TONIGHT ESPECIALLY ACROSS SOUTH CAROLINA WHERE A MID-LEVEL DISTURBANCE IS PROGGED TO MOVE IN FROM THE WEST DURING THE EVENING HOURS. THIS SHOULD SPREAD MID-LEVEL CLOUDS EASTWARD TOWARD THE COAST. A SMALL CHANCE OF SHOWERS AND STORMS WILL BE MAINTAINED OVERNIGHT ACROSS THE PEE DEE REGION DUE TO THE MOISTURE ADVECTING EASTWARD...AND OVERNIGHT LOWS HAVE BEEN ADJUSTED UPWARD DUE TO LESS RADIATIONAL COOLING EXPECTED. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...A BEAUTIFUL WKND IN STORE AS A COLD FRONT WILL BE WELL SOUTH OF THE AREA...LEAVING DRYING AND MOSTLY SUNNY CONDITIONS FOR SATURDAY AND SUNDAY. SATURDAY STILL HAS A CHANCE FOR SOME ISOLATED SHOWERS/TSTMS ACROSS THE SOUTHERN TIER OF ZONES WHERE PWATS WILL BE HIGHER AND THE FRONT WILL STILL BE IN THE VICINITY...POTENTIALLY INTERACTING WITH A WEAK SHORTWAVE MOVING IN FROM THE MIDLANDS OF SC...BUT NOT EXPECTING WIDESPREAD OR HEAVY CONVECTION...AND INTENSITY/COVERAGE WILL DECREASE THROUGH THE AFTN/EVE ON THE DRY ADVECTION. SUNDAY STILL SHAPING UP TO BE A GORGEOUS DAY...ALTHOUGH FLOW IS PROGGED TO RETURN TO THE SW EARLIER THAN PREVIOUSLY. THIS WILL CAUSE TEMPS TO BE WARMER...ALONG WITH SLIGHTLY HIGHER HUMIDITY THAN PREVIOUSLY FORECAST...BUT STILL EXPECT BRIGHT SUNSHINE AND A GREAT LATE- AUGUST DAY. TEMPS SATURDAY WILL BE AROUND SEASONABLE LEVELS AS COOL ADVECTION IS LACKING BEHIND THE FRONT. EXPECT HIGHS AROUND 87 FAR NW TO ABOUT 90 ALONG THE SOUTHERN TIER. MAX TEMPS ON SUNDAY WILL BE ABOUT 1-3 DEGREES WARMER EVERYWHERE. SUB-CLIMO MINS SATURDAY NIGHT THANKS TO THE DRY COLUMN...AND LOWS WILL DROP INTO THE REFRESHING CATEGORY...DROPPING INTO THE MID 60S WELL NW TO AROUND 70 AT THE COAST. MORE TYPICAL MINS SUNDAY NIGHT WITH LOWS A DEGREE OR TWO EITHER SIDE OF 70. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 AM FRIDAY...MID-LEVEL FLOW TO BECOME ANOMALOUSLY AMPLIFIED FOR AUGUST MUCH OF THE UPCOMING WEEK AS A LARGE TROUGH DEVELOPS ACROSS THE EAST WITH A BIG RIDGE BLOSSOMING OVER THE MTN WEST. ALTHOUGH MONDAY WILL FEATURE WARM TEMPS...POSSIBLY ABOVE NORMAL...WITH TYPICAL SUMMERTIME CONVECTION CHANCES...THIS IS LOOKING TO BE THE ONE ABOVE-NORMAL DAY OF THE PERIOD. THEREAFTER A COLD FRONT DROPS INTO THE CAROLINAS AND STALLS THROUGH MID-WEEK BEFORE FINALLY GETTING PUSHED SOUTH LATE WED INTO THU. THIS WILL CREATE AN EXTENDED PERIOD OF UNSETTLED WEATHER WITH GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS...ALONG WITH SUB-CLIMO TEMPS THANKS TO LOWERED THICKNESSES WITHIN THE TROUGH COMBINING WITH CLOUDS AND PRECIP. HARD TO SAY THE ENTIRE TUE-THU PERIOD WILL BE WET AND CLOUDY...BUT AT LEAST A GOOD PORTION OF EACH DAY LOOKS TO BE UNSETTLED WITH HIGHS SLIGHTLY BELOW CLIMO AND LOWS SLIGHTLY ABOVE AS DIURNAL RANGES BECOME COMPRESSED && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... AS OF 12Z...COLD FRONT PUSHING SOUTH THROUGH THE REGION AT THIS TIME. NO WEATHER ASSOCIATED WITH IT...JUST A WIND SHIFT TO THE NORTHWEST. THE HRRR MODEL HAS ISOLATED CONVECTION POPPING UP THIS AFTERNOON...BUT THAT IS A BIT OF A STRETCH AS THERE WILL NOT BE MUCH MOISTURE TO WORK WITH. WINDS CONTINUE TO VEER TO THE NORTHEAST BY AFTERNOON. LIGHT WINDS OVERNIGHT WITH LITTLE OR NO FOG EXPECTED. EXTENDED OUTLOOK...VFR WITH SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THE EXTENDED. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM FRIDAY...SLOW-MOVING COLD FRONT SHOULD MOVE OFF THE BEACHES SHORTLY AFTER SUNRISE THIS MORNING. WESTERLY WINDS IN ADVANCE OF THE FRONT WILL VEER NORTHERLY LATER THIS MORNING BUT WITH NO INCREASE IN WIND SPEED. BY THIS AFTERNOON THE TYPICAL SEABREEZE CIRCULATION SHOULD OVERWHELM WHAT LITTLE WIND EXISTS BEHIND THE FRONT...WITH ONSHORE WINDS 10 KNOTS OR LESS EXPECTED ALL ALONG THE COAST. ENOUGH MOISTURE WILL REMAIN BEHIND THE FRONT THAT A FEW SHOWERS AND STORMS SHOULD FIRE UP DURING THE AFTERNOON HOURS NEAR THE COAST ALONG THE SEABREEZE BOUNDARY. STEERING WINDS ALOFT WILL BE LIGHT AND FROM THE NORTHWEST...PERHAPS PUSHING ANY OF THIS ISOLATED SHOWER/STORM ACTIVITY OUT ACROSS THE BEACHES AND INTO THE COASTAL WATERS. A NORTH-NORTHEAST WIND WILL GRADUALLY INCREASE LATE TONIGHT... REACHING 10-15 KNOTS LATE. SEAS SHOULD AVERAGE ONLY 2 FEET TODAY AND TONIGHT...PERHAPS BUILDING TO 3 FEET IN EXPOSED WATERS LATE. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...HIGH PRESSURE RIDGING DOWN THE COAST BEHIND A COLD FRONT WILL CREATE N/NE WINDS SATURDAY AND THE FIRST HALF OF SUNDAY. THE GRADIENT ASSOCIATED WITH THIS HIGH PRESSURE IS WEAK...SO WIND SPEEDS WILL BE 10 KTS OR LESS FROM THIS DIRECTION...AFTER A BRIEF SURGE UP TO 15 KTS EARLY SATURDAY. LATE SUNDAY...RETURN FLOW WILL BEGIN TO REDEVELOP AS WINDS SHIFT BACK AROUND TO THE SW BUT AT CONTINUED LIGHT SPEEDS. WAVE HEIGHTS WILL BE 2-3 FT EARLY DURING THE RESIDUAL NE SURGE...BUT FALL TO 1-2 FT SATURDAY AFTN AND PERSIST AT THESE AMPLITUDES THROUGH THE WIND SHIFT AND INTO THE END OF THE PERIOD LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 300 AM FRIDAY...SW WINDS AHEAD OF A COLD FRONT WILL INCREASE STEADILY DURING MONDAY...RISING UP TOWARDS 15 KTS LATE IN THE DAY. AS THE COLD FRONT APPROACHES WINDS WILL EASE A BIT MONDAY NIGHT...BUT THIS FRONT WILL LIKELY NOT REACH THE WATERS DURING TUESDAY AND INSTEAD STALL JUST INLAND. THIS WILL CONTINUE S/SW WINDS TUESDAY AT 10-15 KTS. SEAS WILL BE PRIMARILY 2-3 FT THROUGH THE PERIOD WITH A SE GROUND SWELL AND WEAK WIND WAVE COMPRISING THE SPECTRUM. LATE MONDAY AND INTO TUESDAY...SOME 12-SEC PERIOD SWELL FROM DISTANT TROPICAL SYSTEMS MAY ENTER THE SPECTRUM...BUT WILL BE AT 1 FT OR LESS IN AMPLITUDE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JDW NEAR TERM...TRA SHORT TERM...JDW LONG TERM...JDW AVIATION...43 MARINE...TRA/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
630 AM EDT FRI AUG 21 2015 .SYNOPSIS... A COLD FRONT WILL WAVER ACROSS THE AREA TODAY BRINGING A RENEWED CHANCE FOR SHOWERS AND THUNDERSTORMS. MOSTLY SUNNY AND SEASONABLE WEATHER WILL FOLLOW FOR THE WEEKEND BEHIND THIS FRONT. WARMER AND MORE HUMID AIR WILL RETURN NEXT WEEK AHEAD OF A COLD FRONT WHICH WILL APPROACH ON TUESDAY...AND THEN STALL ACROSS THE AREA THROUGH THURSDAY BRINGING COOLER AND UNSETTLED CONDITIONS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM FRIDAY...DESPITE GREAT MODEL-TO-MODEL CONSISTENCY 24 HOURS AGO THE COLD FRONT IS LAGGING THOSE PROGS BY NEARLY 100 MILES THIS MORNING. AT 3 AM THE FRONT APPEARS TO LIE ROUGHLY ALONG INTERSTATE 95...MOVING EASTWARD TOWARD THE COAST AT A SLOW PACE. THE FRONT SHOULD CROSS THE BEACHES SHORTLY AFTER SUNRISE...BUT WITH LITTLE WIND BEHIND THE FRONT THERE WILL BE NO SIGNIFICANT AIRMASS CHANGE. TEMPERATURES RISING INTO THE LOWER 90S INLAND THIS AFTERNOON SHOULD TRIGGER A SEABREEZE WHICH WILL MOVE THE EFFECTIVE LOCATION OF THE FRONT BACK INLAND DUE TO DEVELOPING ONSHORE WINDS ALONG THE COAST. WITH DEWPOINTS HOLDING IN THE LOWER 70S SURFACE-BASED INSTABILITY SHOULD GROW TO 1000-2000 J/KG THIS AFTERNOON. SYNOPTIC AND FINE- SCALE MODELS ALL SHOW THE POTENTIAL FOR AT LEAST SCATTERED SHOWERS AND STORMS THIS AFTERNOON...MOST NUMEROUS NEAR THE COAST WHERE SEABREEZE-ENHANCED CONVERGENCE WILL ASSIST THE GROWING CUMULUS CLOUDS. FORECAST POPS RANGE FROM 20 PERCENT INLAND TO 40 PERCENT ON THE COAST. LIGHT TROPOSPHERIC WINDS MEAN ANY CONVECTION WILL LIKELY BE DISORGANIZED PULSE-TYPE WITH NO SIGNIFICANT POTENTIAL FOR SEVERE WEATHER. DAYTIME CLOUDS WILL BE SLOW TO CLEAR TONIGHT ESPECIALLY ACROSS SOUTH CAROLINA WHERE A MID-LEVEL DISTURBANCE IS PROGGED TO MOVE IN FROM THE WEST DURING THE EVENING HOURS. THIS SHOULD SPREAD MID-LEVEL CLOUDS EASTWARD TOWARD THE COAST. A SMALL CHANCE OF SHOWERS AND STORMS WILL BE MAINTAINED OVERNIGHT ACROSS THE PEE DEE REGION DUE TO THE MOISTURE ADVECTING EASTWARD...AND OVERNIGHT LOWS HAVE BEEN ADJUSTED UPWARD DUE TO LESS RADIATIONAL COOLING EXPECTED. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...A BEAUTIFUL WKND IN STORE AS A COLD FRONT WILL BE WELL SOUTH OF THE AREA...LEAVING DRYING AND MOSTLY SUNNY CONDITIONS FOR SATURDAY AND SUNDAY. SATURDAY STILL HAS A CHANCE FOR SOME ISOLATED SHOWERS/TSTMS ACROSS THE SOUTHERN TIER OF ZONES WHERE PWATS WILL BE HIGHER AND THE FRONT WILL STILL BE IN THE VICINITY...POTENTIALLY INTERACTING WITH A WEAK SHORTWAVE MOVING IN FROM THE MIDLANDS OF SC...BUT NOT EXPECTING WIDESPREAD OR HEAVY CONVECTION...AND INTENSITY/COVERAGE WILL DECREASE THROUGH THE AFTN/EVE ON THE DRY ADVECTION. SUNDAY STILL SHAPING UP TO BE A GORGEOUS DAY...ALTHOUGH FLOW IS PROGGED TO RETURN TO THE SW EARLIER THAN PREVIOUSLY. THIS WILL CAUSE TEMPS TO BE WARMER...ALONG WITH SLIGHTLY HIGHER HUMIDITY THAN PREVIOUSLY FORECAST...BUT STILL EXPECT BRIGHT SUNSHINE AND A GREAT LATE- AUGUST DAY. TEMPS SATURDAY WILL BE AROUND SEASONABLE LEVELS AS COOL ADVECTION IS LACKING BEHIND THE FRONT. EXPECT HIGHS AROUND 87 FAR NW TO ABOUT 90 ALONG THE SOUTHERN TIER. MAX TEMPS ON SUNDAY WILL BE ABOUT 1-3 DEGREES WARMER EVERYWHERE. SUB-CLIMO MINS SATURDAY NIGHT THANKS TO THE DRY COLUMN...AND LOWS WILL DROP INTO THE REFRESHING CATEGORY...DROPPING INTO THE MID 60S WELL NW TO AROUND 70 AT THE COAST. MORE TYPICAL MINS SUNDAY NIGHT WITH LOWS A DEGREE OR TWO EITHER SIDE OF 70. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 AM FRIDAY...MID-LEVEL FLOW TO BECOME ANOMALOUSLY AMPLIFIED FOR AUGUST MUCH OF THE UPCOMING WEEK AS A LARGE TROUGH DEVELOPS ACROSS THE EAST WITH A BIG RIDGE BLOSSOMING OVER THE MTN WEST. ALTHOUGH MONDAY WILL FEATURE WARM TEMPS...POSSIBLY ABOVE NORMAL...WITH TYPICAL SUMMERTIME CONVECTION CHANCES...THIS IS LOOKING TO BE THE ONE ABOVE-NORMAL DAY OF THE PERIOD. THEREAFTER A COLD FRONT DROPS INTO THE CAROLINAS AND STALLS THROUGH MID-WEEK BEFORE FINALLY GETTING PUSHED SOUTH LATE WED INTO THU. THIS WILL CREATE AN EXTENDED PERIOD OF UNSETTLED WEATHER WITH GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS...ALONG WITH SUB-CLIMO TEMPS THANKS TO LOWERED THICKNESSES WITHIN THE TROUGH COMBINING WITH CLOUDS AND PRECIP. HARD TO SAY THE ENTIRE TUE-THU PERIOD WILL BE WET AND CLOUDY...BUT AT LEAST A GOOD PORTION OF EACH DAY LOOKS TO BE UNSETTLED WITH HIGHS SLIGHTLY BELOW CLIMO AND LOWS SLIGHTLY ABOVE AS DIURNAL RANGES BECOME COMPRESSED && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... AS OF 12Z...COLD FRONT PUSHING SOUTH THROUGH THE REGION AT THIS TIME. NO WEATHER ASSOCIATED WITH IT...JUST A WIND SHIFT TO THE NORTHWEST. THE HRRR MODEL HAS ISOLATED CONVECTION POPPING UP THIS AFTERNOON...BUT THAT IS A BIT OF A STRETCH AS THERE WILL NOT BE MUCH MOISTURE TO WORK WITH. WINDS CONTINUE TO VEER TO THE NORTHEAST BY AFTERNOON. LIGHT WINDS OVERNIGHT WITH LITTLE OR NO FOG EXPECTED. EXTENDED OUTLOOK...VFR WITH SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THE EXTENDED. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM FRIDAY...A SLOW-MOVING COLD FRONT SHOULD MOVE OFF THE BEACHES SHORTLY AFTER SUNRISE THIS MORNING. WESTERLY WINDS IN ADVANCE OF THE FRONT WILL VEER NORTHERLY THIS MORNING BUT WITH NO INCREASE IN WIND SPEED. BY THIS AFTERNOON THE TYPICAL SEABREEZE CIRCULATION SHOULD OVERWHELM WHAT LITTLE WIND EXISTS BEHIND THE FRONT...WITH ONSHORE WINDS 10 KNOTS OR LESS EXPECTED ALL ALONG THE COAST. ENOUGH MOISTURE WILL REMAIN BEHIND THE FRONT THAT SCATTERED SHOWERS AND STORMS SHOULD FIRE UP DURING THE AFTERNOON HOURS NEAR THE COAST ALONG THE SEABREEZE BOUNDARY. STEERING WINDS ALOFT WILL BE LIGHT AND FROM THE NORTHWEST...PERHAPS PUSHING ANY SHOWERS AND STORMS OUT ACROSS THE BEACHES AND INTO THE COASTAL WATERS. A NORTH-NORTHEAST WIND WILL GRADUALLY INCREASE LATE TONIGHT...REACHING 10-15 KNOTS LATE. SEAS SHOULD AVERAGE ONLY 2 FEET TODAY AND TONIGHT...PERHAPS BUILDING TO 3 FEET IN EXPOSED WATERS LATE. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...HIGH PRESSURE RIDGING DOWN THE COAST BEHIND A COLD FRONT WILL CREATE N/NE WINDS SATURDAY AND THE FIRST HALF OF SUNDAY. THE GRADIENT ASSOCIATED WITH THIS HIGH PRESSURE IS WEAK...SO WIND SPEEDS WILL BE 10 KTS OR LESS FROM THIS DIRECTION...AFTER A BRIEF SURGE UP TO 15 KTS EARLY SATURDAY. LATE SUNDAY...RETURN FLOW WILL BEGIN TO REDEVELOP AS WINDS SHIFT BACK AROUND TO THE SW BUT AT CONTINUED LIGHT SPEEDS. WAVE HEIGHTS WILL BE 2-3 FT EARLY DURING THE RESIDUAL NE SURGE...BUT FALL TO 1-2 FT SATURDAY AFTN AND PERSIST AT THESE AMPLITUDES THROUGH THE WIND SHIFT AND INTO THE END OF THE PERIOD LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 300 AM FRIDAY...SW WINDS AHEAD OF A COLD FRONT WILL INCREASE STEADILY DURING MONDAY...RISING UP TOWARDS 15 KTS LATE IN THE DAY. AS THE COLD FRONT APPROACHES WINDS WILL EASE A BIT MONDAY NIGHT...BUT THIS FRONT WILL LIKELY NOT REACH THE WATERS DURING TUESDAY AND INSTEAD STALL JUST INLAND. THIS WILL CONTINUE S/SW WINDS TUESDAY AT 10-15 KTS. SEAS WILL BE PRIMARILY 2-3 FT THROUGH THE PERIOD WITH A SE GROUND SWELL AND WEAK WIND WAVE COMPRISING THE SPECTRUM. LATE MONDAY AND INTO TUESDAY...SOME 12-SEC PERIOD SWELL FROM DISTANT TROPICAL SYSTEMS MAY ENTER THE SPECTRUM...BUT WILL BE AT 1 FT OR LESS IN AMPLITUDE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JDW NEAR TERM...TRA SHORT TERM...JDW LONG TERM...JDW AVIATION...43 MARINE...TRA/JDW
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
955 AM CDT FRI AUG 21 2015 .UPDATE... ISSUED AT 955 AM CDT FRI AUG 21 2015 WE ARE GETTING SMOKE INTO THE REGION...AND THIS WILL IMPACT HIGH TEMPS SOME TODAY. WE WILL LOWER TEMPS TODAY ABOUT 2-4 DEGREES GIVEN THICKER HIGH LEVEL SMOKE. OTHERWISE...NO OTHER MAJOR CHANGES NEEDED. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 345 AM CDT FRI AUG 21 2015 FORECAST CHALLENGES WILL BE SEVERE THREAT SATURDAY AS WELL AS RAINFALL AMOUNTS MAINLY THIS WEEKEND AND TEMPERATURES/WIND. MODELS OVERALL IN PRETTY GOOD AGREEMENT THROUGH THE PERIOD AND WILL USE MODEL BLEND. CURRENT SHORTWAVE PROPAGATING EAST ACROSS SW MB INTO ONTARIO THIS MORNING. ASSOCIATED AREA OF SHRA/ISOLD T ON NOSE OF LOW LEVEL JET IN WARM ADVECTION ZONE. ALTHOUGH INSTABILITY AND CAPE MINIMAL A FEW LIGHTNING STRIKES OCCURRING. CURRENT HRRR WEAKENS PCPN THROUGH THE MORNING AND OUT OF THE FA BY MID MORNING. WILL MAINTAIN LOW POPS BASED ON SHORT TERM MODEL GUIDANCE. THE REMAINDER OF THIS AFTERNOON SHOULD REMAIN DRY. CONTINUED WARM ADVECTION WILL SET UP WARM FRONTAL BOUNDARY ALONG THE INTERNATIONAL BORDER BY THIS EVENING. WITH FA IN WARM SECTOR TEMPERATURES SHOULD RECOVER WELL WITH MOST AREAS ABOVE AVERAGE. TONIGHT MORE SIGNIFICANT WAVE CURRENTLY OVER BC WILL DIG INTO THE NORTHERN ROCKIES. ASSOCIATED SURFACE LOW WILL ORGANIZE OVER THE WESTERN DAKOTAS WITH SW-NE ORIENTED BOUNDARY SETTING UP LATER IN THE NIGHT. WILL CONTINUE WITH CHANCE POPS ALONG THIS BOUNDARY. TEMPERATURES WILL REMAIN MILD OVERNIGHT. SURFACE LOW WILL LIFT NE SATURDAY AS WAVE APPROACHES. AS IT DOES ASSOCIATED COLD FRONT WILL FOLLOW LOW AND BE ORIENTED CLOSE TO THE VALLEY BY PRIME HEATING. CONVECTIVE PARAMETERS FAVORABLE FOR SEVERE STORMS ALONG AND AHEAD OF THE BOUNDARY SO SEVERE POTENTIAL WILL HINGE ON JUST WHERE BOUNDARY SETS UP. DEGREE OF CLOUD COVER WILL GOVERN TEMPERATURES WITH COOLEST READINGS OVER THE FAR NW WHICH WILL BE BEHIND THE COLD FRONT. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 345 AM CDT FRI AUG 21 2015 UPPER TROUGH CLOSES OFF SATURDAY NIGHT AS IT LIFTS NE. WRAP AROUND/DEF ZONE RAIN WILL FOLLOW. AT THIS POINT MODEL GUIDANCE SUGGESTS THAT THE BEST POTENTIAL FOR RAIN WILL BE OVER THE NORTHERN 2/3RD OF THE FA. SUNDAY WILL BE WINDY AND COOLER WITH DEF ZONE PCPN BAND SHIFTING EAST ACROSS THE FA. COOLER COLUMN AND CLOUDS WILL HOLD TEMPERATURES DOWN. RAIN WILL MOVE OUT OF THE NE FA SUNDAY NIGHT. WINDS TO DIMINISH BUT WILL BE A COOL NIGHT WITH MINIMUM TEMPERATURES IN THE 40S. LONG WAVE TROUGHS WERE OFF THE WESTERN CANADIAN COAST AND THE GREAT LAKES WITH A FLAT RIDGE OVER MT. PATTERN AMPLIFIES WITH A TROUGH OVER THE EASTERN PACIFIC/WESTERN CANADA AND RIDGING INTO THE NORTHERN PLAINS BY THE END OF THE PERIOD. GFS AND ECMWF WERE IN BETTER AGREEMENT WITH TODAYS MODEL RUN THROUGH THE PERIOD. THE ECMWF WAS SLIGHTLY FASTER THAN THE GFS. THE ECMWF WAS VACILLATING AROUND A POINT WHILE THE GFS WAS TRENDING SLOWER OVER THE LAST COUPLE MODEL RUNS. NO CHANGE TO HIGH TEMPS FOR MON. HIGH TEMPS WERE DECREASED A DEGREE OR TWO FOR TUE AND WED, AND INCREASED ZERO TO FOUR DEGREES FOR THU FORM YESTERDAYS PACKAGE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 639 AM CDT FRI AUG 21 2015 CIGS ASSOCIATED WITH SHRA OVER THE NORTHERN FA REMAIN IN THE MID LEVELS WITH CLEARING REACHING THE NORTHERN VALLEY. EXPECT MID LEVEL CIGS TO EXIT THE FA BY LATE MORNING WITH VFR CONDITIONS CONTINUING THROUGH THE REMAINDER OF THE PERIOD. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...DK SHORT TERM...VOELKER LONG TERM...HOPPES/VOELKER AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
644 AM CDT FRI AUG 21 2015 .UPDATE... ISSUED AT 639 AM CDT FRI AUG 21 2015 SHRA SHRINKING IN COVERAGE AND CONFINED TO NW MN EAST OF NORTHERN VALLEY. NO LTG STRIKES IN THE LAST FEW HOURS SO TRANSITIONED BACK TO SHRA. MADE SOME MINOR POP ADJUSTMENTS THROUGH THE REMAINDER OF THE MORNING WITH NO OTHER FORECAST CHANGES. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 345 AM CDT FRI AUG 21 2015 FORECAST CHALLENGES WILL BE SEVERE THREAT SATURDAY AS WELL AS RAINFALL AMOUNTS MAINLY THIS WEEKEND AND TEMPERATURES/WIND. MODELS OVERALL IN PRETTY GOOD AGREEMENT THROUGH THE PERIOD AND WILL USE MODEL BLEND. CURRENT SHORTWAVE PROPAGATING EAST ACROSS SW MB INTO ONTARIO THIS MORNING. ASSOCIATED AREA OF SHRA/ISOLD T ON NOSE OF LOW LEVEL JET IN WARM ADVECTION ZONE. ALTHOUGH INSTABILITY AND CAPE MINIMAL A FEW LIGHTNING STRIKES OCCURRING. CURRENT HRRR WEAKENS PCPN THROUGH THE MORNING AND OUT OF THE FA BY MID MORNING. WILL MAINTAIN LOW POPS BASED ON SHORT TERM MODEL GUIDANCE. THE REMAINDER OF THIS AFTERNOON SHOULD REMAIN DRY. CONTINUED WARM ADVECTION WILL SET UP WARM FRONTAL BOUNDARY ALONG THE INTERNATIONAL BORDER BY THIS EVENING. WITH FA IN WARM SECTOR TEMPERATURES SHOULD RECOVER WELL WITH MOST AREAS ABOVE AVERAGE. TONIGHT MORE SIGNIFICANT WAVE CURRENTLY OVER BC WILL DIG INTO THE NORTHERN ROCKIES. ASSOCIATED SURFACE LOW WILL ORGANIZE OVER THE WESTERN DAKOTAS WITH SW-NE ORIENTED BOUNDARY SETTING UP LATER IN THE NIGHT. WILL CONTINUE WITH CHANCE POPS ALONG THIS BOUNDARY. TEMPERATURES WILL REMAIN MILD OVERNIGHT. SURFACE LOW WILL LIFT NE SATURDAY AS WAVE APPROACHES. AS IT DOES ASSOCIATED COLD FRONT WILL FOLLOW LOW AND BE ORIENTED CLOSE TO THE VALLEY BY PRIME HEATING. CONVECTIVE PARAMETERS FAVORABLE FOR SEVERE STORMS ALONG AND AHEAD OF THE BOUNDARY SO SEVERE POTENTIAL WILL HINGE ON JUST WHERE BOUNDARY SETS UP. DEGREE OF CLOUD COVER WILL GOVERN TEMPERATURES WITH COOLEST READINGS OVER THE FAR NW WHICH WILL BE BEHIND THE COLD FRONT. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 345 AM CDT FRI AUG 21 2015 UPPER TROUGH CLOSES OFF SATURDAY NIGHT AS IT LIFTS NE. WRAP AROUND/DEF ZONE RAIN WILL FOLLOW. AT THIS POINT MODEL GUIDANCE SUGGESTS THAT THE BEST POTENTIAL FOR RAIN WILL BE OVER THE NORTHERN 2/3RD OF THE FA. SUNDAY WILL BE WINDY AND COOLER WITH DEF ZONE PCPN BAND SHIFTING EAST ACROSS THE FA. COOLER COLUMN AND CLOUDS WILL HOLD TEMPERATURES DOWN. RAIN WILL MOVE OUT OF THE NE FA SUNDAY NIGHT. WINDS TO DIMINISH BUT WILL BE A COOL NIGHT WITH MINIMUM TEMPERATURES IN THE 40S. LONG WAVE TROUGHS WERE OFF THE WESTERN CANADIAN COAST AND THE GREAT LAKES WITH A FLAT RIDGE OVER MT. PATTERN AMPLIFIES WITH A TROUGH OVER THE EASTERN PACIFIC/WESTERN CANADA AND RIDGING INTO THE NORTHERN PLAINS BY THE END OF THE PERIOD. GFS AND ECMWF WERE IN BETTER AGREEMENT WITH TODAYS MODEL RUN THROUGH THE PERIOD. THE ECMWF WAS SLIGHTLY FASTER THAN THE GFS. THE ECMWF WAS VACILLATING AROUND A POINT WHILE THE GFS WAS TRENDING SLOWER OVER THE LAST COUPLE MODEL RUNS. NO CHANGE TO HIGH TEMPS FOR MON. HIGH TEMPS WERE DECREASED A DEGREE OR TWO FOR TUE AND WED, AND INCREASED ZERO TO FOUR DEGREES FOR THU FORM YESTERDAYS PACKAGE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 639 AM CDT FRI AUG 21 2015 CIGS ASSOCIATED WITH SHRA OVER THE NORTHERN FA REMAIN IN THE MID LEVELS WITH CLEARING REACHING THE NORTHERN VALLEY. EXPECT MID LEVEL CIGS TO EXIT THE FA BY LATE MORNING WITH VFR CONDITIONS CONTINUING THROUGH THE REMAINDER OF THE PERIOD. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...VOELKER SHORT TERM...VOELKER LONG TERM...HOPPES/VOELKER AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
1114 AM EDT FRI AUG 21 2015 .DISCUSSION... POST-FRONTAL HIGH PRESSURE FILLING INTO THE REGION. DEW POINTS GETTING A LITTLE LOWER AHEAD OF SCHEDULE...ACROSS THE BOARD...SO LOWERED DEW POINTS 1-3 DEG AS NEEDED. ALSO STRATOCUMULUS DECK ACROSS NORTHERN ALABAMA AND MIDDLE TENNESSEE WILL BE SPREADING ACROSS OUR SOUTHERN COUNTIES...LOWERED MAX TEMPS 1-2 DEG IN THOSE AREAS. KEEPING SWRN COUNTIES DRY WITH THIS UPDATE FOR THIS AFTERNOON. DON`T THINK SHOWERS IN MISSISSIPPI WILL MAKE IN FIRST PERIOD...AND HRRR HAS THEM FADING ANYWAY. ALSO...MODEL SOUNDINGS DON`T LOOK FAVORABLE FOR CONVECTIVE DEVELOPMENT...COOLER SURFACE UNDER CLOUD COVER AND DRIER AIR ALOFT THAT WOULD GET ENTRAINED. WILL KEEP LIGHT POPS IN EXTREME SE COUNTIES FOR NOW DUE TO POSSIBLE EXTRA OROGRAPHIC LIFT THERE. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 84 68 87 67 / 10 10 10 20 KNOXVILLE MCGHEE TYSON AIRPORT, TN 84 65 86 65 / 10 10 10 20 OAK RIDGE, TN 85 63 86 64 / 10 0 10 20 TRI CITIES AIRPORT, TN 84 59 84 61 / 10 0 10 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ GM
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
935 AM CDT FRI AUG 21 2015 .UPDATE... EARLY MORNING SHOWERS AND THUNDERSTORMS OVER THE COASTAL AREAS HAS SENT AN OUTFLOW THAT GENERATED SHOWERS AND THUNDERSTORMS OVER THE EASTERN PARTS OF SOUTH CENTRAL TEXAS. HAVE BOOSTED POPS 10 TO 20 PERCENT ACROSS AREAS EAST OF I-35 TO ACROSS THE AUSTIN AREA INTO THE NORTHEASTERN HILL COUNTRY. DUE TO CLOUDS AND RAIN LINGERING INTO THE AFTERNOON DUE TO BEING ON THE EASTERN SIDE OF THE MID TO UPPER LEVEL SHEAR AXIS...HAVE ALSO LOWERED TEMPERATURES SLIGHTLY. REMAINDER OF SOUTH CENTRAL TEXAS FORECAST IS ON TRACK. && .PREV DISCUSSION... /ISSUED 650 AM CDT FRI AUG 21 2015/ AVIATION.../12Z TAF CYCLE/ LOWER CIGS HAVE FILLED IN AS EXPECTED THIS MORNING WITH WIDESPREAD MVFR WITH INTERMINGLED IFR CONDITIONS PRESENT ACROSS CENTRAL TAF SITES WITH KDRT MVFR AS WELL. AMPLE MOISTURE IN THE LOWER LAYERS WILL TAKE SOME TIME TO MIX OUT THROUGH 15-17Z WITH A GRADUAL IMPROVEMENT THROUGH MVFR TO EVENTUAL VFR FALL ALL SITES BY LATE MORNING TO EARLY AFTERNOON. A COMPLEX OF SHOWERS AND STORMS IS MOVING INLAND NEAR KVCT BUT WILL LIKELY MISS THE CENTRAL SITES. FEEL MOST SCATTERED ACTIVITY WILL REMAIN SOUTHEAST OF THE MAIN TERMINALS AND HAVE REFRAINED FROM VCTS WORDING THIS TAF CYCLE. TRENDS WILL NEED TO BE MONITORED HOWEVER FOR POSSIBLE INCLUSION ON 18Z CYCLE. SURFACE WINDS ARE LIGHT AND VARIABLE CURRENTLY BUT WILL PICK UP TO 10-15 KT THIS AFTN FROM THE SOUTHEAST TO SOUTH DIRECTION. PREV DISCUSSION... /ISSUED 333 AM CDT FRI AUG 21 2015/ SHORT TERM (TODAY THROUGH SATURDAY)... A N-S ORIENTED SHEAR AXIS MOST NOTABLE IN THE MID LEVELS OVER S TX AND ADJACENT AREAS OF NERN MEXICO SHOULD BRING ANOTHER DAY OF CONVECTION AND MODERATED DAYTIME TEMPERATURES FOR THE EASTERN HALF OF SOUTH CENTRAL TX. WHILE THE FRONTAL ZONE THAT BROUGHT WELL BELOW NORMAL MAX TEMPS TO THE AREA THURSDAY HAS RETREATED NORTH...SOME COASTAL TROUGHING IS STILL NOTED NEAR CRP...AND A SMALL COMPLEX OF STORMS CONFIRMS THE UNSTABLE ENVIRONMENT THAT COULD SPREAD INLAND LATER THIS MORNING. RAPID REFRESH MODEL RUNS DEPICT EARLY DESTABILIZATION NEAR AND EAST OF I-35 TODAY...BUT EARLIER RUNS OF THE HRRR WERE SHOWN TO BE TOO AGGRESSIVE WITH CONVECTION IN THE PRE-DAWN HOURS. ADDITIONAL MOISTURE AND POSSIBLE INSTABILITY IS MOVING IN FROM NW FLOW ALOFT FROM WEST TX...BUT WITH ONLY THE 00Z NSSL WRF MODEL SHOWING AN IMPACT OVER OUR WESTERN COUNTIES VERSUS SEVERAL THAT DO NOT...WILL STICK WITH THE CONSENSUS POPS FOR THE SERN TWO-THIRDS OF THE FORECAST AREA. BLENDED GUIDANCES CONTAIN ARTIFACTS OF EARLIER FORECAST HIGHER TEMPS...SO OPTED FOR A BLEND OF MAV/MET FOR HIGHS. MODEL RUN TO RUN TRENDS IN THE EARLY PERIODS SHOW MORE SHEAR THAN EARLIER RUNS...SO WILL FOLLOW THIS TREND TO KEEP A SLIGHTLY LESS STABLE PICTURE FOR OUR SOUTHERN/WRN COUNTIES FOR SATURDAY. INCREASED RIDGING AND DRY AIR ENTRAINMENT FROM THE NORTH SHOULD PRECLUDE CONVECTION OVER MOST OF SOUTH CENTRAL TEXAS...BUT THE WESTWARD SHIFTING SHEAR AXIS SHOULD PULL SOME MOISTURE WITH IT TO BRING A SLIGHT CHANCE OF DAYTIME CONVECTION OVER THE RIO GRANDE PLAINS. MEANWHILE SOUTHERN PARTS OF THE COASTAL PLAINS LOSE THE CYCLONIC SHEAR BUT MAINTAIN LOCALLY HIGHER PWAT VALUES FOR ONE MORE DAY. WILL FAVOR THE GFS BASED GUIDANCE FOR WARMER TEMPS TO REGAIN CONTROL OVER CENTRAL TX WHERE THE DRIER AND MORE STABLE MID- LEVEL AIR MOVES IN. LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)... THE BRIEF BREAK FROM THE HEAT IS ALL BUT FORGOTTEN BY SUNDAY. THE GFS AND ECMWF BOTH BUILD A STRONG RIDGE OVER THE SOUTHERN ROCKIES WITH AN AXIS THAT EXTENDS SE ACROSS CENTRAL TX. WILL SHADE TOWARD THE HIGHER MEX GUIDANCE ON MAXES SUNDAY THROUGH WEDNESDAY AS AUGUST RAINS HAVE BEEN MOSTLY TOO SPARSE TO PROVIDE FEEDBACK THROUGH SOIL AND VEGETATION. LATE MONDAY THROUGH DAYTIME WEDNESDAY...THERE IS A SIGNAL FOR MID-LEVEL MOISTURE POOLING TO SPREAD SOUTH FROM NORTH TX AS NORTHERLY FLOW INCREASES ALOFT. THUS WILL SHADE TOWARD THE SLIGHTLY MORE UNSTABLE ECMWF OVER THE SLIGHTLY DRIER GFS FOR THOSE DAYS. LITTLE OR NO CONVECTION IS SHOWN BY EITHER MODEL FOR THE REMAINDER OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 91 76 98 77 99 / 40 10 10 - - AUSTIN BERGSTROM INTL AIRPORT 92 73 97 75 98 / 40 10 10 - - NEW BRAUNFELS MUNI AIRPORT 92 75 98 76 98 / 30 10 10 - - BURNET MUNI AIRPORT 92 74 97 75 98 / 20 10 10 - - DEL RIO INTL AIRPORT 96 76 98 78 99 / 10 - 20 - - GEORGETOWN MUNI AIRPORT 92 76 96 76 98 / 40 10 10 - 10 HONDO MUNI AIRPORT 95 74 96 75 97 / 20 10 10 - - SAN MARCOS MUNI AIRPORT 92 75 98 76 99 / 30 10 10 - - LA GRANGE - FAYETTE REGIONAL 91 76 96 76 98 / 50 20 20 10 10 SAN ANTONIO INTL AIRPORT 93 76 97 77 98 / 30 10 10 - - STINSON MUNI AIRPORT 93 76 98 77 99 / 30 20 10 - - && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...TREADWAY SYNOPTIC/GRIDS...04 PUBLIC SERVICE/DATA COLLECTION...10
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
655 AM CDT FRI AUG 21 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 318 AM CDT FRI AUG 21 2015 MOST OF THE FORECAST TIME THIS MORNING WAS ENSURING WE WERE ON TRACK WITH RAIN CHANCES IN THE RETURN FLOW TODAY....CLOUDS ON SATURDAY...BUT MAINLY THE SATURDAY NIGHT THUNDERSTORM THREATS AND ANY MESSAGING THAT WILL BE NEEDED FOR THOSE OUTDOORS. CURRENT OBSERVATIONAL DATA AS OF 21.07Z INDICATES NW-SE ORIENTED CLOUD BANDING AROUND 10KFT ACROSS CENTRAL MN ASSOCIATED WITH FRONTOGENESIS IN THE 800-900 MB LAYER PER LATEST RAP ANALYSIS. TSRA AND LIGHTNING IN NWRN IA ON THE NOSE OF THE LOW-LEVEL JET PER 88D VWPS AND RAP ANALYSIS. SPC MESOANALYSIS SHOWING THAT TSRA IS ON THE NORTHERN EXTENT OF THE MUCAPE REGION /ONLY ABOUT 250 J/KG THERE/. GOES FOG PRODUCT AND SURFACE OBSERVATIONS SHOW A LOWER CLOUD FIELD OVER OK/TX SOUTH IN A RICH MOIST POOL OF SURFACE DEWPOINTS OVER 65F...AND 925MB DEWPOINTS AT 18C PER 21.00Z RAOBS. WILL HAVE TO WATCH THIS AREA AS IT ADVECTS NORTHWARD AHEAD OF THE FRONT THAT IS MOVING IN FOR SATURDAY NIGHT...ASSOCIATED WITH THE SHORTWAVE TROUGH NOW WORKING SOUTHWARD THROUGH BRITISH COLUMBIA /PER GOES WATER VAPOR/. RAP ANALYSIS INDICATES THIS SPINNER HAS A TROPOPAUSE FOLD DOWN TO ROUGHLY 750 MB...SO A POTENT VORTEX. SHORT TERM GUIDANCE SUPPORTS EVOLVING THE FRONTOGENESIS AND THE LOW-LEVEL JET NOSE CONVERGENCE NORTHEAST THROUGH THE FIRST PORTION OF TODAY INTO NRN WI BY AFTERNOON. THERE WILL LIKELY BE VERY LIGHT RADAR RETURNS AND PER 00Z RAOB DATA...SOME PRETTY DRY AIR TO OVERCOME BELOW THE ACCAS CLOUD BASE /10KFT/. FOR NOW...HAVE KEPT THE HIGHER PROBABILITY DRY FORECAST. SPRINKLES OR AN ISOLATED WETTING SHOWER MAY BE POSSIBLE WITH FORCING EVOLUTION NEWRD. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 318 AM CDT FRI AUG 21 2015 NO BIG CHANGES DURING THIS PERIOD. SOUTHWESTERLY FLOW WILL PREVAIL SATURDAY AND PRE-FRONTALLY WILL NEED TO WATCH THE SURGE OF 925 MB MOISTURE NORTHWARD TONIGHT. CONSENSUS 21.00Z GUIDANCE SUGGESTS THIS TONGUE REMAINS WEST OF THE AREA UNTIL FRONT ARRIVES SAT EVENING. HAVE INCREASED WIND GUSTS SATURDAY WITH STRONGER LOW-LEVEL WIND FIELD SUGGESTED AND MIXING DEPTH INTO THE 35-38KT CONSENSUS 900MB WINDS. TIMING IS ABOUT THE SAME AS PREVIOUS FORECASTS FOR FRONT TO BECOME ACTIVE TO THE WEST OF THE AREA LATER SATURDAY. THIS FRONT IS ASSOCIATED WITH THE BRITISH COLUMBIA SHORTWAVE AS IT DIGS SOUTHEAST INTO CENTRAL MN...THEN EJECTS NORTHEAST OVER DULUTH. THUS...THE AREA ISNT DIRECTLY HIT BY THE MID-UPPER TROPOSPHERIC FORCING...WHICH FAVORS BETTER CONVECTION TO EJECT NORTHEAST...BUT BROAD ASCENT FROM LARGE SCALE FORCING IS OVER THE AREA. THE CAPE AXIS IS VERY NARROW...RIGHT ALONG THE FRONT...WITH A STOUT CAP OUT AHEAD SUGGESTED. MUCAPE HAS REMARKABLE DROP SUGGESTED IN THE MODEL GUIDANCE FROM 7PM TO 1 AM...ABOUT 2500 IN PEAK HEATING WEST OF THE FORECAST AREA...TO ABOUT 750 J/KG BY 1 AM ON THE MISS RIVER. THE WESTERN FORECAST AREAS OF NERN IA AND SERN MN HAVE THE MOST POTENTIAL FOR SEVERE STORMS FOR A SMALL WINDOW SATURDAY EVENING AS THE STORMS WEAKEN HEADING EAST. SPC DAY 2 RISK HAS SHIFTED THE SLIGHT RISK EAST INTO THAT AREA...BUT NOT TOO MUCH HAS CHANGED. MODEST 0-3KM WIND SHEAR WOULD FAVOR LINE SEGMENTS PROMOTING DAMAGING WINDS. THE 0-3KM SHEAR VECTOR IS ALIGNED PERPENDICULAR TO THE FRONT OR CONVECTIVE LINE...PROMOTING BETTER COLD POOL MAINTENANCE. SEVERE THREAT DEPENDS ON TIMING OF THE FRONT AND STORMS. ARRIVAL IN THE EARLY EVENING WOULD FAVOR HIGHER SEVERE STORM CHANCES PER HIGHER CAPE IN MODEST LOW-LEVEL SHEAR. CONSENSUS MODEL GUIDANCE IS A MID-LATER EVENING APPROACH OF STORMS IN NERN IA AND SERN MN WITH STORMS JUST PAST PEAK AND INTO WEAKENING STAGE...WITH COLD POOLS THAT COULD PROBABLY PRODUCE ISOLATED WIND DAMAGE. WILL TAKE A SLIGHT STEP UP IN MESSAGING MOVING TO STRONG TO ISOLATED SEVERE STORMS. A COOL FIRST HALF OF THE WEEK IN NORTHWEST FLOW WITH DRIER && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 650 AM CDT FRI AUG 21 2015 WARM AIR ADVECTION AND SOME MOISTURE TRANSPORT WILL CONTINUE TO PRODUCE A SCATTERED TO BROKEN MID DECK OF CLOUDS ACROSS THE AREA TODAY...AND THEN SKIES WILL CLEAR. WITH DIURNAL MIXING TODAY... THE SUSTAINED SOUTH WINDS WILL CLIMB INTO THE 10 TO 20 KNOTS... AND THE WINDS WILL GUST INTO THE 20 TO 30 KNOT RANGE. THE WINDS WILL THEN SUBSIDE QUICKLY THIS EVENING. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BAUMGARDT LONG TERM...BAUMGARDT AVIATION...BOYNE
AREA FORECAST DISCUSSION...UPDATE
NWS PHOENIX AZ
1020 AM MST FRI AUG 21 2015 .UPDATE... AVIATION DISCUSSION. && .SYNOPSIS... THUNDERSTORMS WILL GENERALLY REMAIN CONFINED TO THE HIGHER TERRAIN OF SOUTHERN AND EASTERN ARIZONA THROUGH THE WEEKEND. HIGH PRESSURE WILL SETTLE ACROSS THE FOUR CORNERS MONDAY...RESULTING IN BETTER RAIN CHANCES ACROSS THE LOWER DESERTS. DRIER CONDITIONS WILL RETURN BY MIDWEEK ALONG WITH NEAR TO ABOVE NORMAL TEMPERATURES. && .DISCUSSION... A SHEARING SHORTWAVE WAS STILL EVIDENT OVER FAR SERN ARIZONA/SW NEW MEXICO ON MORNING WV IMAGERY...WITH FLOW OTHERWISE BACKING TO WLY IN THE MIDLEVELS THROUGH THE FORECAST AREA. RATHER EXTENSIVE ACCAS CONTINUED TO PERCOLATE FROM ERN PIMA THROUGH GILA COUNTY IN ASSOCIATION WITH A SLUG OF MOISTURE IN THE H8-H7 LAYER TRAPPED BELOW A WEAK ELEVATED CAPPED LAYER. HOWEVER...THE MOST NOTABLE FEATURES IN 12Z SOUNDING DATA IS RICH MOISTURE AVAILABILITY IN THE BOUNDARY LAYER WITH KPSR DATA MEASURING 11-12 G/KG IN THE SFC-H7 LAYER...AND KTWC SAMPLING AN IMPRESSIVE 14-15 G/KG IN A SFC-750MB LAYER. AS A RESULT...LATEST MESOANALYSIS ESTIMATES MLCAPES IN THE SERN QUARTER OF ARIZONA ALREADY ECLIPSING THE 1500-2000 J/KG RANGE...ALBEIT WITH CINH STILL PRESENT. DESPITE THESE EXCESSIVE LEVELS OF INSTABILITY...THERE IS LITTLE TO NOTHING EVIDENT IN SATELLITE IMAGERY THAT COULD BE TERMED AS A LIFTING MECHANISM...AND THE FACT THAT THE ACCAS TURRETS HAVE NOT EXPERIENCED UPSCALE GROWTH SUGGEST LARGER SCALE SUBSIDENCE STILL PREDOMINATES ACROSS THE REGION. THEREFORE...WITH STILL ONLY LIMITED SUPPORT FOR HIGH RESOLUTION ENSEMBLE DATA...MADE VERY LITTLE CHANGE TO POPS THE REMAINDER OF THE DAY. HOWEVER...AM STILL CONCERNED DESPITE THE LOWER CONFIDENCE GIVEN THE POTENTIAL LARGE IMPACTS GIVEN THE HIGH INSTABILITY VALUES. WILL CONTINUE TO EVALUATE CONVECTIVE POTENTIAL AND COVERAGE THROUGH THE AFTERNOON. && .PREVIOUS DISCUSSION... /502 AM MST FRI AUG 21 2015/ AN ANTICYCLONE IN THE MID AND UPPER LEVELS REMAINS POSITIONED OFF THE BAJA PENINSULA...RESULTING IN A WESTERLY COMPONENT TO THE FLOW. AT THE SURFACE...YUMA VWP SUGGESTS THAT A SHALLOW GULF SURGE IS TAKING PLACE ACROSS SOUTHWESTERN AZ. DEWPOINTS NEAR YUMA AND ACROSS THE IMPERIAL VALLEY HAVE RESPONDED...INCREASING INTO THE MID TO UPPER 70S EARLY THIS MORNING. FURTHER EAST ACROSS THE LOWER DESERTS OF SOUTH-CENTRAL AZ...AN INFLUX OF MOISTURE IS ALSO ANTICIPATED THIS MORNING...BUT TO A LESSER DEGREE. SOME EARLIER WRF-BASED GUIDANCE INDICATED THAT SHOWERS AND THUNDERSTORMS WOULD DEVELOP THIS MORNING ACROSS PORTIONS OF THE LOWER DESERTS. HOWEVER...THE LATEST LOCAL WRFS AND U OF ARIZONA WRFS HAVE BACKED OFF CONSIDERABLY AND DEPICT CONVECTION BEING MOST CONCENTRATED ACROSS THE HIGHER TERRAIN SOUTH AND EAST OF PHOENIX THIS AFTERNOON. SEVERAL RUNS OF THE HRRR HAVE ALSO DISMISSED THE POSSIBILITY OF CONVECTION STARTING EARLY THIS MORNING...THOUGH CAPES ABOVE 1000 J/KG SHOULD CERTAINLY SUPPORT DEVELOPMENT BY EARLY AFTERNOON. LACK OF A TRIGGER IN THE UPPER LEVELS ALONG WITH WEAK WESTERLY FLOW POINT TO TERRAIN- BASED CONVERGENCE AS THE PRIMARY LIFTING MECHANISM. NEVERTHELESS...THERE IS A SLIGHT CHANCE OF THUNDERSTORMS IN THE PHOENIX AREA...THOUGH THE GREATER LIKELIHOOD IS FOR AREAS OF BLOWING DUST. MEAN FLOW WILL BECOME MORE WESTERLY SATURDAY AS THE ANTICYCLONE DRIFTS NORTHWARD. THIS WILL AGAIN CONFINE THUNDERSTORMS MAINLY TO THE HIGHER TERRAIN EAST OF PHOENIX. MORE OF THE SAME FOR SUNDAY AS THE HIGH DRIFTS OVERHEAD. CONDITIONS WILL BECOME SOMEWHAT MORE FAVORABLE FOR PRECIPITATION EARLY NEXT WEEK AS THE MONSOON HIGH BECOMES REESTABLISHED ACROSS THE FOUR CORNERS. INCREASING EASTERLY COMPONENT TO THE FLOW GENERALLY FAVORS HIGHER CHANCES OF THUNDERSTORMS. HOWEVER...MODEL CROSS SECTIONS INDICATE THAT ABUNDANT MOISTURE IN THE MID AND UPPER LEVELS MAY RESULT IN CONSIDERABLE CLOUDINESS AND ULTIMATELY A DECREASE IN INSTABILITY AND THE POTENTIAL FOR THUNDERSTORMS ACROSS THE AREA. OPERATIONAL GFS AND ECMWF ALSO SUGGEST THE PRESENCE OF AN INVERTED TROUGH ACROSS NORTHERN SONORA...THOUGH DIFFERENCES IN THE STRENGTH AND TIMING OF THIS FEATURE ARE APPARENT. GENERAL CONSENSUS AMONG THE MODELS FOR NEXT WEEK IS THAT THE MONSOON HIGH WILL DRIFT EASTWARD AND SOUTHWARD. FLOW WILL GRADUALLY BECOME SOUTHWESTERLY AGAIN...FAVORING THE HIGHER TERRAIN FOR CONVECTION. TEMPERATURES AT OR ABOVE NORMAL ARE EXPECTED THROUGH THE EXTENDED. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL A RATHER MESSY EASTERLY FLOW ACROSS THE PHX AREA CONTINUES LATE THIS MORNING. FULLY EXPECT WESTERLY FLOW TO DEVELOP OVER THE NEXT FEW HOURS...APPEARING NOT AS STRONG/GUSTY AS EARLIER. ONE THING TO WATCH IS A FEW THUNDERSHOWERS WELL E OF THE PHX AREA. ATMOSPHERE DOES HAVE A DECENT AMOUNT OF INSTABILITY TODAY BUT NO CLEAR MECHANISM TO RELEASE IT. SHOULD STORMS OVER SE AZ DEVELOP BETTER THROUGH THE DAY...MAY CONTEND WITH NEARBY TS AND OUTFLOW FOR PHX AREA TERMINALS. MOST LIKELY OUTCOME IS A SUNNY AND QUIET DAY. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... TYPICAL DIURNAL WIND PATTERNS WITH CLEAR SKIES THROUGH AT LEAST 00Z SUNDAY. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SUNDAY THROUGH THURSDAY... MONSOON MOISTURE LEVELS AND HUMIDITIES WILL PERSIST THROUGH MIDWEEK. STORM CHANCES WILL CONTINUE FOR THE HIGHER TERRAIN LOCALES FOR SUNDAY BEFORE EXPANDING INTO THE LOWER DESERT ELEVATIONS BY THE EARLY WORK WEEK AS SOME UPPER LEVEL DISTURBANCES PASS THROUGH THE AREA AND SUPPORT THE POTENTIAL FOR MORE WIDESPREAD STORM DEVELOPMENT. DAYTIME HUMIDITIES WILL RANGE FROM THE 20 TO 30 PERCENT RANGE WHILE MAKING GOOD OVERNIGHT RECOVERIES. OUTSIDE OF THUNDERSTORM OUTFLOW AND VICINITY WINDS...SFC WINDS TO MAINTAIN DAYTIME HEADINGS 10 TO 20 MPH WHILE BECOMING DOWN DRAINAGE/DOWN VALLEY IN THE OVERNIGHTS. A SLIGHT DRAW DOWN OF MONSOON MOISTURE AND INTRUSION OF WESTERLY FLOW ALOFT WILL RELEGATE STORM CHANCES BACK ACROSS EASTERN AZ FOR THE LATTER PART OF THE WEEK...WHILE TEMPERATURES ALSO BEGIN TO WARM TO ABOVE NORMAL VALUES. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...MO/HIRSCH AVIATION...NOLTE FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS TUCSON AZ
1004 AM MST FRI AUG 21 2015 .SYNOPSIS...SHOWER AND THUNDERSTORM CHANCES WILL CONTINUE TO INCREASE THROUGH THE COMING WEEKEND WITH A MORE TYPICAL MONSOON PATTERN EXPECTED INTO EARLY NEXT WEEK. THE INCREASED MOISTURE WILL ALSO KEEP DAYTIME TEMPERATURES CLOSER TO SEASONAL AVERAGES FRIDAY INTO EARLY NEXT WEEK. && .DISCUSSION...THE TUCSON MORNING UPPER-AIR SOUNDING INDICATED A RATHER MOIST AND UNSTABLE AIRMASS IN PLACE ACROSS THE AREA. IN FACT...A FEW SHOWERS AND THUNDERSTORMS WERE ALREADY REDEVELOPING IN COCHISE COUNTY AS OF 10 AM MST. LATEST HRRR SOLUTIONS SUGGESTED ANOTHER ACTIVE THUNDERSTORM DAY INSTORE FOR SOUTHEAST ARIZONA TODAY. RAIN CHANCES IN THE CURRENT FORECAST STILL LOOKED ON TRACK...SO NO PLANS TO UPDATE THE FORECAST AT THIS TIME. PLEASE REFER THE ADDITIONAL SECTIONS FOR MORE DETAILS. && .AVIATION...VALID THRU 22/18Z. SKC-FEW HIGH CIRRUS CLOUDS AT 20-25K FT...THEN SCT-BKN CLOUDS AT 7- 11K FT AGL REDEVELOPING THIS AFTERNOON...ALONG WITH ISOLATED TO SCATTERED SHRA/TSRA. BRIEF MVFR CONDITIONS...ALONG WITH STRONG GUSTY WINDS POSSIBLE IN AN AROUND SHRA/TSRA. OTHERWISE...WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...MOISTURE WILL CONTINUE TO INCREASE WITH ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED THIS AFTERNOON AND EVENING WITH AN EMPHASIS ON AREAS FROM TUCSON AND POINTS EASTWARD. THEREAFTER...MOISTURE AND THUNDERSTORMS CHANCES WILL INCREASE AND SPREAD THROUGHOUT SOUTHEAST ARIZONA THROUGH THE WEEKEND INTO EARLY NEXT WEEK. EXPECT A DECREASE IN SHOWER AND THUNDERSTORMS DURING THE MIDDLE TO LATTER PART OF NEXT WEEK. WINDS WILL BE TYPICAL FOR MID AUGUST AND GENERALLY LESS THAN 15 MPH WITH AFTERNOON GUSTINESS... ESPECIALLY IN THE GILA RIVER VALLEY. && .PREV DISCUSSION...THERE IS A VERY WEAK FEATURE OVER NORTHERN BAJA THAT SHOULD MOVE SLOWLY EASTWARD AND POTENTIALLY HELP OUT ALONG OR SOUTH OF THE BORDER LATE TODAY BUT IT IS MUCH LESS SIGNIFICANT THAN WHAT HELPED YESTERDAYS CONVECTION. SO OVERALL WITH THE INSTABILITY AND MOISTURE THAT WE HAVE WOULD EXPECT CONVECTION TO FIRE UP OVER HIGHER TERRAIN EARLY THIS AFTERNOON ACROSS THE EASTERN TWO THIRDS OF THE AREA THEN SPREAD FROM THERE DUE TO OUTFLOWS. WHAT WILL BE INTERESTING IS STORM MOTION AS THE UPPER LEVEL WINDS ARE LIGHTER THAN YESTERDAY SO STORM MOTION WILL BE SLOWER AND LIKELY A BIT TO THE EAST ALTHOUGH OUTFLOWS WILL LIKELY DRIVE THE MOVEMENT OF SOME STORMS IN THIS LIGHT FLOW. WITH 102 AS A HIGH THURSDAY I WENT AHEAD AND BUMPED TODAYS TEMPS A DEGREE OR TWO FROM WHAT WAS IN THERE. IF THE CONVECTION IS SLOWER TO DEVELOP WILL LIKELY BE A BIT HIGHER YET. ON SATURDAY THE UPPER HIGH NOW JUST TO OUR SW WILL BE MOVING EAST ACROSS THE AREA THROUGH THE DAY. WILL STILL HAVE A GOOD AMOUNT OF MOISTURE HOWEVER MID LEVEL TEMPS WILL BE A BIT WARMER FOR LESS INSTABILITY. SHOULD STILL SEE CONVECTION DEVELOP JUST NOT EXPECTING AN ABUNDANCE OF IT AND WILL LIKELY BE FOCUSED ON THE TERRAIN FROM TUCSON EASTWARD. IT POTENTIALLY BECOMES A BIT MORE INTERESTING AFTER THAT AS THE HIGH CONTINUES EAST TO NEW MEXICO/TEXAS BY SUNDAY. GUIDANCE CONTINUES TO SHOW A DISTURBANCE OVER MEXICO MOVING WNW ACROSS THE AREA SUNDAY INTO MONDAY. VARIOUS MODELS DIFFER ON THE TIMING WITH THE GFS BEING THE QUICKER OF THE BUNCH ON THE LATEST RUN. WHEN THIS DOES PASS IT SHOULD RAMP UP THE CONVECTION AND AT THIS TIME THE MOST LIKELY TIME WOULD BE LATE SUNDAY INTO MONDAY. I RAISED POPS A BIT THROUGH THIS TIME FRAME TO TRY TO CAPTURE THIS BUT WE WILL NEED TO KEEP AN EYE ON THIS AS THE TIME APPROACHES FOR MORE DETAILS AS THE BULK OF IT COULD SLIDE BY JUST TO OUR SOUTH DEPENDING ON THE LOCATION OF THE EAST/WEST RIDGE AXIS. SUNDAY AND MONDAY LIKELY THE COOLEST DAYS OF THE FORECAST PERIOD WITH HIGHS A BIT BELOW NORMAL. TUESDAY AND WEDNESDAY THE UPPER HIGH IS IN A PRETTY GOOD POSITION FOR CONVECTIVE ACTIVITY OVER THE CWA AND HAVE LEFT THE POPS AS THEY WERE WHICH IS ABOUT 5-10 POINTS ABOVE CLIMO. WITH A BIT MORE SUNSHINE BUMPED TEMPS BACK UP A BIT. SHOULD BE ABLE TO ADD A FEW MORE 100+ DEGREE DAYS TO THE TALLY FOR TUCSON. THURSDAY ONWARD THE UPPER HIGH IS PROGGED TO SLIDE RIGHT OVER THE AREA WHICH WOULD ACT TO SHUT OFF THE MOISTURE FLOW AND SUPPRESS CONVECTION WHILE ALSO ALLOWING FOR ABOVE NORMAL TEMPERATURES. TWEAKED THE GRIDS WITH THAT IN MIND...SLIGHTLY DRIER AND WARMER. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
945 AM MST FRI AUG 21 2015 .SYNOPSIS... THUNDERSTORMS WILL GENERALLY REMAIN CONFINED TO THE HIGHER TERRAIN OF SOUTHERN AND EASTERN ARIZONA THROUGH THE WEEKEND. HIGH PRESSURE WILL SETTLE ACROSS THE FOUR CORNERS MONDAY...RESULTING IN BETTER RAIN CHANCES ACROSS THE LOWER DESERTS. DRIER CONDITIONS WILL RETURN BY MIDWEEK ALONG WITH NEAR TO ABOVE NORMAL TEMPERATURES. && .DISCUSSION... A SHEARING SHORTWAVE WAS STILL EVIDENT OVER FAR SERN ARIZONA/SW NEW MEXICO ON MORNING WV IMAGERY...WITH FLOW OTHERWISE BACKING TO WLY IN THE MIDLEVELS THROUGH THE FORECAST AREA. RATHER EXTENSIVE ACCAS CONTINUED TO PERCOLATE FROM ERN PIMA THROUGH GILA COUNTY IN ASSOCIATION WITH A SLUG OF MOISTURE IN THE H8-H7 LAYER TRAPPED BELOW A WEAK ELEVATED CAPPED LAYER. HOWEVER...THE MOST NOTABLE FEATURES IN 12Z SOUNDING DATA IS RICH MOISTURE AVAILABILITY IN THE BOUNDARY LAYER WITH KPSR DATA MEASURING 11-12 G/KG IN THE SFC-H7 LAYER...AND KTWC SAMPLING AN IMPRESSIVE 14-15 G/KG IN A SFC-750MB LAYER. AS A RESULT...LATEST MESOANALYSIS ESTIMATES MLCAPES IN THE SERN QUARTER OF ARIZONA ALREADY ECLIPSING THE 1500-2000 J/KG RANGE...ALBEIT WITH CINH STILL PRESENT. DESPITE THESE EXCESSIVE LEVELS OF INSTABILITY...THERE IS LITTLE TO NOTHING EVIDENT IN SATELLITE IMAGERY THAT COULD BE TERMED AS A LIFTING MECHANISM...AND THE FACT THAT THE ACCAS TURRETS HAVE NOT EXPERIENCED UPSCALE GROWTH SUGGEST LARGER SCALE SUBSIDENCE STILL PREDOMINATES ACROSS THE REGION. THEREFORE...WITH STILL ONLY LIMITED SUPPORT FOR HIGH RESOLUTION ENSEMBLE DATA...MADE VERY LITTLE CHANGE TO POPS THE REMAINDER OF THE DAY. HOWEVER...AM STILL CONCERNED DESPITE THE LOWER CONFIDENCE GIVEN THE POTENTIAL LARGE IMPACTS GIVEN THE HIGH INSTABILITY VALUES. WILL CONTINUE TO EVALUATE CONVECTIVE POTENTIAL AND COVERAGE THROUGH THE AFTERNOON. && .PREVIOUS DISCUSSION... /502 AM MST FRI AUG 21 2015/ AN ANTICYCLONE IN THE MID AND UPPER LEVELS REMAINS POSITIONED OFF THE BAJA PENINSULA...RESULTING IN A WESTERLY COMPONENT TO THE FLOW. AT THE SURFACE...YUMA VWP SUGGESTS THAT A SHALLOW GULF SURGE IS TAKING PLACE ACROSS SOUTHWESTERN AZ. DEWPOINTS NEAR YUMA AND ACROSS THE IMPERIAL VALLEY HAVE RESPONDED...INCREASING INTO THE MID TO UPPER 70S EARLY THIS MORNING. FURTHER EAST ACROSS THE LOWER DESERTS OF SOUTH-CENTRAL AZ...AN INFLUX OF MOISTURE IS ALSO ANTICIPATED THIS MORNING...BUT TO A LESSER DEGREE. SOME EARLIER WRF-BASED GUIDANCE INDICATED THAT SHOWERS AND THUNDERSTORMS WOULD DEVELOP THIS MORNING ACROSS PORTIONS OF THE LOWER DESERTS. HOWEVER...THE LATEST LOCAL WRFS AND U OF ARIZONA WRFS HAVE BACKED OFF CONSIDERABLY AND DEPICT CONVECTION BEING MOST CONCENTRATED ACROSS THE HIGHER TERRAIN SOUTH AND EAST OF PHOENIX THIS AFTERNOON. SEVERAL RUNS OF THE HRRR HAVE ALSO DISMISSED THE POSSIBILITY OF CONVECTION STARTING EARLY THIS MORNING...THOUGH CAPES ABOVE 1000 J/KG SHOULD CERTAINLY SUPPORT DEVELOPMENT BY EARLY AFTERNOON. LACK OF A TRIGGER IN THE UPPER LEVELS ALONG WITH WEAK WESTERLY FLOW POINT TO TERRAIN- BASED CONVERGENCE AS THE PRIMARY LIFTING MECHANISM. NEVERTHELESS...THERE IS A SLIGHT CHANCE OF THUNDERSTORMS IN THE PHOENIX AREA...THOUGH THE GREATER LIKELIHOOD IS FOR AREAS OF BLOWING DUST. MEAN FLOW WILL BECOME MORE WESTERLY SATURDAY AS THE ANTICYCLONE DRIFTS NORTHWARD. THIS WILL AGAIN CONFINE THUNDERSTORMS MAINLY TO THE HIGHER TERRAIN EAST OF PHOENIX. MORE OF THE SAME FOR SUNDAY AS THE HIGH DRIFTS OVERHEAD. CONDITIONS WILL BECOME SOMEWHAT MORE FAVORABLE FOR PRECIPITATION EARLY NEXT WEEK AS THE MONSOON HIGH BECOMES REESTABLISHED ACROSS THE FOUR CORNERS. INCREASING EASTERLY COMPONENT TO THE FLOW GENERALLY FAVORS HIGHER CHANCES OF THUNDERSTORMS. HOWEVER...MODEL CROSS SECTIONS INDICATE THAT ABUNDANT MOISTURE IN THE MID AND UPPER LEVELS MAY RESULT IN CONSIDERABLE CLOUDINESS AND ULTIMATELY A DECREASE IN INSTABILITY AND THE POTENTIAL FOR THUNDERSTORMS ACROSS THE AREA. OPERATIONAL GFS AND ECMWF ALSO SUGGEST THE PRESENCE OF AN INVERTED TROUGH ACROSS NORTHERN SONORA...THOUGH DIFFERENCES IN THE STRENGTH AND TIMING OF THIS FEATURE ARE APPARENT. GENERAL CONSENSUS AMONG THE MODELS FOR NEXT WEEK IS THAT THE MONSOON HIGH WILL DRIFT EASTWARD AND SOUTHWARD. FLOW WILL GRADUALLY BECOME SOUTHWESTERLY AGAIN...FAVORING THE HIGHER TERRAIN FOR CONVECTION. TEMPERATURES AT OR ABOVE NORMAL ARE EXPECTED THROUGH THE EXTENDED. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL AND SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... EARLY AM SCT-BKN CLOUDS BETWEEN PHX AND CGZ WILL SETTLE OUT TO FEW- SCT MID-LEVEL CLOUDS FOR THE AFTN...WITH SKIES REMAINING MOSTLY CLEAR FOR THE WESTERN TERMINALS OF BLH AND IPL. S-SE AM WINDS TO PREVAIL FOR THE TERMINALS SAVE FOR KPHX...WHICH WILL MAINTAIN SUBTLE W-NW HEADINGS WITH PERIODS OF VRB. AFTN WINDS TO BECOME S-SW FOR THE PHX AREA TERMINALS...WITH PERIODS OF 20KT GUSTINESS. ISO TS SHOULD FORM WELL EAST AND SOUTH OF THE PHX AREA...WITH VERY REMOTE CHANCES OF OUTFLOW RELATED IMPACTS INTO KIWA DURING THE EVENING. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SUNDAY THROUGH THURSDAY... MONSOON MOISTURE LEVELS AND HUMIDITIES WILL PERSIST THROUGH MIDWEEK. STORM CHANCES WILL CONTINUE FOR THE HIGHER TERRAIN LOCALES FOR SUNDAY BEFORE EXPANDING INTO THE LOWER DESERT ELEVATIONS BY THE EARLY WORK WEEK AS SOME UPPER LEVEL DISTURBANCES PASS THROUGH THE AREA AND SUPPORT THE POTENTIAL FOR MORE WIDESPREAD STORM DEVELOPMENT. DAYTIME HUMIDITIES WILL RANGE FROM THE 20 TO 30 PERCENT RANGE WHILE MAKING GOOD OVERNIGHT RECOVERIES. OUTSIDE OF THUNDERSTORM OUTFLOW AND VICINITY WINDS...SFC WINDS TO MAINTAIN DAYTIME HEADINGS 10 TO 20 MPH WHILE BECOMING DOWN DRAINAGE/DOWN VALLEY IN THE OVERNIGHTS. A SLIGHT DRAW DOWN OF MONSOON MOISTURE AND INTRUSION OF WESTERLY FLOW ALOFT WILL RELEGATE STORM CHANCES BACK ACROSS EASTERN AZ FOR THE LATTER PART OF THE WEEK...WHILE TEMPERATURES ALSO BEGIN TO WARM TO ABOVE NORMAL VALUES. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...MO/HIRSCH AVIATION...NOLTE FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
908 AM PDT FRI AUG 21 2015 .Synopsis... Dry weather with near normal temperatures through early next week. Hazy/smoky conditions will continue in portions of NorCal. && .Short Term Discussion (Today through Monday)... The Delta Breeze is still healthy early this morning some stratus that formed over northeastern Sacramento county, but it won`t last very long. The short term forecast into Monday will be reasonable & seasonable. Daytime highs will generally oscillate within 5 degrees of normal. For areas influenced by the Delta Breeze, daytime highs will be near to slightly below normal while other areas will be near to slightly above normal. For today, Valley highs will range upper 80s (near Delta) to upper 90s (near Redding) while max temps in higher terrain will range in the 70s (higher elevations of the Sierra) to the upper 80s/low 90s (foothill locations). Very subtle warming occurs starting Saturday as ridging strengthens over NorCal. The main concern in the short term are the hazy/smoky conditions due to fires that continue to burn, especially the many fires in Trinity county. The HRRR model showed that smoke particulates from the Trinity vicinity could move southward today towards Sacramento area and then curl around as the Delta Breeze moves northward up the valley. However, the satellite imagery this morning indicates less smoke than yesterday, with a swath south and east of Sacramento area and a west to east plume into Redding. In any case, some degree of haze will be present over the next several days. JBB/JClapp && .Extended Discussion (Tuesday through Friday) Near normal temperatures on Tuesday will be followed by temperatures trending down through the rest of the week into the weekend as a cool trough from the Gulf of Alaska approaches. How quickly this system moves in is still in doubt, as the 00Z GFS and ECMWF have essentially traded positions from model runs yesterday, with the GFS now keeping a closed low off the coast and the ECMWF bringing a quicker moving trough in on Friday. This would bring the potential for some precipitation into far northern California late Friday. While the GFS does keep the main low off the coast, it does have a weak shortwave on Friday afternoon. Have introduced just a slight chance of rain showers for the northern Coastal Range for Friday afternoon. Will be watching to see if later model runs trend closer together and need to expand this later. Current Global Ensemble Forecast System (GEFS) ensembles and analogs are pointing towards a cool down for late in the week. Highs by Friday may stay in the 80s, even over the northern Sacramento Valley. Increased cloud cover if the trough moves inland would be a factor in this. EK && .Aviation... General VFR conditions expected over the next 24 hours. MVFR with local IFR cigs expected into I-680 until 17-18z, with bases BKN010-012 in NE Sacramento county before eroding around 17z. Wildfire smoke may pose slant-range visibility issues. JClapp && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
300 PM MDT FRI AUG 21 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 300 PM MDT FRI AUG 21 2015 TRAILING SOUTHERN END OF A SHORTWAVE MOVING THROUGH WESTERLY FLOW ALOFT ACROSS WY AND NE CO HAS TRIGGERED THUNDERSTORMS ALONG THE SFC TROF AXIS ACROSS EASTERN CO. MEANWHILE...REMNANT MOISTURE CAUGHT WITHIN THE FLAT UPPER RIDGE ACROSS SOUTHWEST CO HAS TRIGGERED THUNDERSTORMS ACROSS THE EASTERN SAN JUANS. THESE TWO AREAS WILL BE THE FOCUS FOR CONTINUED THUNDERSTORM DEVELOPMENT THROUGH THIS EVENING. POTENTIAL FOR STRONGEST THUNDERSTORMS WILL BE ACROSS THE FAR SOUTHEAST PLAINS...NAMELY KIOWA...PROWERS AND BACA COUNTIES. DEW POINTS EAST OF THE SFC TROF AXIS WILL REMAIN IN THE 50S...YIELDING 2500+ J/KG AND DEEP LAYER SHEARS OF 30-35 KTS. THIS WILL BE SUFFICIENT FOR ONE OR TWO SEVERE THUNDERSTORMS THROUGH THE LATE AFTERNOON AND EVENING HOURS. HRRR PUTS THE GREATEST THREAT ACROSS EASTERN KIOWA...PROWERS AND BACA COUNTIES. ACTIVITY SHOULD SHIFT EASTWARD INTO KS BY 00Z. FOR THE SOUTHWEST MTS...MAIN THREAT WILL BE LOCALLY HEAVY RAINFALL...THOUGH STORM MOTIONS TO THE EAST AT 15-20 KTS SHOULD HELP MITIGATE THE THREAT FOR FLASH FLOODING ON THE WEST FORK BURN SCAR SOME. THIS AREA WILL STILL NEED TO BE MONITORED CLOSELY THOUGH. LOW TEMPERATURES TONIGHT SHOULD STAY ON THE MILD SIDE...PARTICULARLY FOR THE SE PLAINS WHERE DOWNSLOPE WESTERLY WINDS INTO THE SFC TROF WILL CONTINUE. MOISTURE LEVELS INCREASE OUT WEST A TAD WHICH SHOULD KEEP MINS UP A COUPLE DEGREES OVER LAST NIGHTS VALUES AS WELL. UPPER TROF WILL DROP OUT OF CANADA AND ACROSS THE NRN U.S. ROCKIES ON SATURDAY. THIS WILL EVENTUALLY SEND A COLD FRONT THROUGH THE SOUTHEAST PLAINS LATE SAT AFTN/EVENING. AHEAD OF THE FRONT ON SATURDAY...EXPECT TEMPERATURES TO WARM QUICKLY. DEW POINTS WILL BE THE LIMITING FACTOR...THOUGH THEY DO START TO REBOUND FROM THE 30S INTO THE 40S ACROSS NORTHERN PORTIONS OF THE SE PLAINS LATE SAT AS THE FRONT DROPS IN. CAPE VALUES WILL BE CONSIDERABLY LOWER...PERHAPS UP TO 1000 J/KG BUT MOST LIKELY BELOW THIS VALUE. SO NOT EXPECTING ANY SEVERE THUNDERSTORMS. BUT COULD SEE SOME ISOLATED STRONGER CELLS CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL...WHICH WOULD BE MORE OF A CONCERN FOR BURN SCARS IN EL PASO COUNTY. FOR NOW...THREAT DOESN`T LOOK ALL THAT HIGH. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 300 PM MDT FRI AUG 21 2015 ...COOLER SUNDAY WITH A SLOW RETURN OF THE MONSOON INTO MIDDLE OF NEXT WEEK... SATURDAY NIGHT-SUNDAY NIGHT...MODERATE TO STRONG WEST TO NORTHWEST LOW ALOFT ACROSS THE REGION SATURDAY NIGHT MODERATES THROUGH THE DAY ON SUNDAY...AS A PASSING NORTHERN TIER UPPER TROUGH CONTINUES TO TRANSLATE SOUTH AND EAST ACROSS THE NORTHERN ROCKIES AND NORTHERN HIGH PLAINS AND UPPER LEVEL RIDGING REBUILDS WEST ACROSS THE SOUTHERN ROCKIES AND INTO THE DESERT SOUTHWEST. MODELS REMAIN SIMILAR WITH BEST FORCING NORTH OF THE AREA...ALTHOUGH COULD SEE SOME CONVECTION ALONG AN ASSOCIATED COLD FRONT MOVING ACROSS EASTERN COLORADO LATE SATURDAY AFTERNOON THROUGH SATURDAY NIGHT. COLD FRONT WILL ALSO BE MARKED WITH GUSTY NORTH TO NORTHEAST WINDS OF 20-30 MPH IN ITS WAKE. OVERNIGHT LOWS TO BE TRICKY SATURDAY NIGHT...ESPECIALLY ACROSS EASTERN COLORADO WITH WINDS SLOWLY DECOUPLING BEHIND SAID FRONT. MODELS INDICATING A SLIGHT INCREASE IN AVAILABLE MOISTURE ON SUNDAY...SUPPORTING ISOLATED TO SCATTERED STORMS OVER AND NEAR THE HIGHER TERRAIN. THE BEST COVERAGE OF STORMS LOOK TO BE ACROSS THE SOUTHERN MTS WITH THE EASTERN PLAINS EXPECTED TO BE CAPPED. HIGHS ON SUNDAY TO BE 5-15F COOLER THAN SATURDAY...MOST NOTABLE OVER THE EASTERN PLAINS WITH BREEZY SOUTH TO SOUTHEAST UPSLOPE FLOW DEVELOPING IN THE AFTERNOON. WARMING ALOFT NOTED ACROSS THE AREA SUNDAY NIGHT...THOUGH COULD SEE SOME COOLER OVERNIGHT LOWS SUNDAY NIGHT WITH GOOD RADIATIONAL COOLING ACROSS THE LOWER ELEVATIONS. MONDAY-FRIDAY...A RETURN TO A MORE MONSOONAL PATTERN LOOKS TO BE IN THE OFFING AS THE UPPER RIDGE ACROSS THE DESERT SOUTHWEST AND INTO THE GREAT BASIN SLOWLY BUILDS EAST ACROSS THE CENTRAL AND NORTHERN ROCKIES. SOME DIFFERENCES NOTED IN LONGER RANGE MODELS WITH THE LATEST GFS BRINGING A DISTURBANCE ACROSS THE STATE ON WEDNESDAY SUPPORTING MORE WIDESPREAD CONVECTION ACROSS THE AREA...WHERE AS THE ECMWF IS SLOWER AND FURTHER NORTH WITH THE DISTURBANCE. AT ANY RATE...SHOULD SEE A SLOW INCREASE IN SUBTROPICAL MOISTURE THROUGH THE PERIOD...WITH DAILY CHANCES OF SHOWERS AND THUNDERSTORMS OVER AND NEAR THE HIGHER TERRAIN SLOWLY INCREASING AND SPREADING EAST THROUGH THE PERIOD. AT OR ABOVE SEASONAL TEMPERATURES EXPECTED TO RETURN TO THE AREA THROUGH THE PERIOD. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 300 PM MDT FRI AUG 21 2015 CONDITIONS SHOULD REMAIN VFR AT THE TERMINALS...WITH SMOKE REDUCING THE VISIBILITIES AT TIMES. FOR NOW...DO NOT THINK SMOKE WILL BECOME THICK ENOUGH TO REDUCE VISIBILITIES TO UNDER 6 MILES. ISOLATED THUNDERSTORMS THIS EVENING ARE EXPECTED TO BYPASS THE TERMINALS...THOUGH KALS COULD SEE A WINDOW OF GUSTY WEST WINDS IF THUNDERSTORM OUTFLOWS HOLD TOGETHER AS THEY PUSH EASTWARD OFF THE SOUTHWEST MTS. THUNDERSTORMS WILL DIMINISH THIS EVENING. A FRONT WILL DROP SOUTH OF THE PALMER DIVIDE SAT AFTERNOON...AND WILL BRING A SLIGHTLY BETTER CHANCE FOR THUNDERSTORMS AT THE KCOS TAF SITE DURING THE AFTERNOON. LIGHTNING...BRIEF RAINFALL AND GUSTY OUTFLOW WINDS WILL BE THE PRIMARY STORM THREATS. THIS FRONT WILL SHIFT SOUTHWARD INTO THE KPUB AREA AROUND 00Z SUN. NORTHERLY WIND GUSTS BEHIND THE FRONT COULD GUST UP TO 30-35 KTS AT BOTH KCOS AND KPUB. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KT LONG TERM...MW AVIATION...KT
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
303 PM EDT FRI AUG 21 2015 .DISCUSSION... TONIGHT AND SATURDAY...EAST AND WEST COAST BREEZE BOUNDARIES COMING TOGETHER OVER THE CENTER OF THE STATE WILL BRING THE BEST CHANCE FOR STORM DEVELOPMENT LATE THIS AFTERNOON AND INTO THE EARLY EVENING. LTST HRRR GUID SHOWS A BREEZE COLLISION WEST OF METRO ORLANDO AFTER 5 PM. A FEW STRONG STORMS WILL BE POSSIBLE WITH WIND GUSTS OF 40 TO 50 MPH AND FREQUENT LIGHTNING...ESP FROM THE THEME PARKS TO LAKE COUNTY AND LAKE GEORGE. PCPN TIED TO SFC HEATING AND BOUNDARY COLLISIONS SHOULD COME TO AN END OVER LAND AREAS BY 1030 PM. SAT...STACKED HIGH OVER THE STATE WL MAINTAIN CONTROL WITH MORE STABLE CONDS OVERALL. NE WINDS WL WOKR SWD FROM THE MID ATLC SEABOARD...PROVIDING ADTL LWR LEVEL STABILITY IN THE FORM OF A MARINE INFLUENCE TO THE COAST AND ESP NORTHERN AREAS. PRECIP CHCS HAVE BEEN TAPERED BACK TO ISOLD ALONG THE CST AND 30 TO 40 PERCENT INLAND. CONVERGENCE IN THE AFTN BEST SUITABLE FOR PCPN DEVELOPMENT SHOULD LARGELY OCCUR OVER THE WESTERN SIDE OF THE PENINSULA. SUN...(MODIFIED PREV DISC)...MID-LEVEL HIGH PRESSURE OVER THE GOMEX GRADUALLY WEAKENS AS SHORTWAVE IMPULSES TRAVERSE THE N/NE PERIPHERY OF THIS ANTI-CYCLONE. THIS WILL ALLOW NORTHERLY WINDS TO BACK TO NORTHWESTERLY. 500 MB TEMPERATURES WILL REMAIN FAIRLY WARM AT -5C/- 6C. AT THE SURFACE HIGH PRESSURE ACROSS THE EASTERN CONUS WILL WEAKEN AND DRIFT TOWARD THE EASTERN SEABOARD/WESTERN ATLC WITH THE APPROACH OF A COLD FRONT. THE SURFACE PRESSURE GRADIENT WILL REMAIN WEAK THROUGH THIS PERIOD WITH LIGHT NORTHEASTERLY FLOW. THE EAST COAST SEA BREEZE WILL DEVELOP EACH DAY AND PUSH INLAND. GREATEST STORM CHANCES WILL FAVOR THE INTERIOR EACH AFTERNOON WITH STEERING FLOW FROM THE N/NNE. MON-THU...TROUGHING IN THE MID-LEVELS WILL GRADUALLY DEVELOP ACROSS THE EASTERN CONUS THROUGH THIS TIME AS NWRLY FLOW ALOFT BECOMES SWRLY ACROSS THE AREA. DEEP LAYER MOISTURE WILL BE LOWER THAN PREVIOUS DAYS. A WEAK SURFACE BOUNDARY WILL BECOME NEAR STATIONARY ACROSS THE DEEP SOUTH WITH WEAK HIGH PRESSURE CONTINUING OVER ECFL. OUR LIGHT ONSHORE FLOW WILL BECOME LIGHT S/SWRLY WED-THU THOUGH THE EAST COAST SEA BREEZE WILL STILL DEVELOP EACH AFTERNOON AND PUSH INLAND. NORTHERLY STORM STEERING FLOW WILL CONTINUE MON-TUE WITH LOWER CONFIDENCE WED-THU IN STORM MOTION...THOUGH IT APPEARS TO BE LIGHT/ERRATIC FOR NOW. LOWER THAN NORMAL PRECIPITATION CHANCES LIKELY MON-TUE WITH AN UPTICK AGAIN MOVING INTO/PAST MID-WEEK TOWARDS CLIMO NUMBERS. && .AVIATION...VFR CONDS ALL COASTAL SITES WITH BRIEF MVFR CONDS PSBL INTERIOR SITES THIS AFTN THROUGH 22/02Z IN ISOLD RELATIVELY BRIEF TSRA/SHRA...OTHERWISE VFR CONDS INTERIOR AS WELL THROUGH 22/16Z. && .MARINE... TONIGHT AND SATURDAY...LIGHT WINDS WITH THE DIURNAL ONSHORE BREEZE IN THE AFTERNOON WL MAINTAIN SIG WVS 2 FT OR LESS DURING THE PERIOD. ONSHORE WINDS WILL INCREASE FROM N TO S ON SAT AS A NE PRIMARY WIND ENTERS THE NE AND CENTRAL FL WATERS BY LATE SATURDAY AFTN. NEXT WEEK...WEAK PRESSURE GRADIENT OVER THE AREA WITH A LIGHT N/NE WIND FLOW BELOW 10 KTS. GRADIENT IS SO WEAK THAT WINDS MAY BE MORE VARIABLE IN DIRECTION AT TIMES. THE ECSB WILL DEVELOP EACH AFTERNOON PUSHING INLAND WITH A SLIGHT BUMP UP IN SPEEDS NEAR THE IMMEDIATE COAST. ONLY AN ISOLD THREAT FOR SHRA/TSRA. SEA HEIGHTS AOB 3 FT. MON-TUE...THE WEAK PRESSURE GRADIENT AND LIGHT WIND FIELDS CONTINUE INTO EARLY WEEK AS A WEAK FRONTAL BOUNDARY SETTLES ACROSS THE DEEP SOUTH/SOUTHEAST U.S. DAILY SEA BREEZE FORMATION AND PUSH INLAND DURING THE AFTERNOON WILL ALSO REMAIN COMMON. SHOWER/STORM CHANCES REMAIN ISOLD. SEAS AOB 3 FT. && .PRELIMINARY POINT TEMPS/POPS... DAB 76 93 76 90 / 20 20 20 20 MCO 76 94 76 93 / 30 40 20 20 MLB 76 92 77 90 / 20 20 20 20 VRB 73 91 74 89 / 20 20 20 20 LEE 77 95 77 93 / 30 40 20 30 SFB 77 95 77 93 / 30 40 20 20 ORL 77 95 77 94 / 30 40 20 20 FPR 74 92 74 89 / 20 20 20 20 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ PUBLIC/MARINE...PENDERGRAST IMPACT WEATHER/AVIATION...WIMMER
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
310 PM EDT FRI AUG 21 2015 .SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/... FRONTAL BOUNDARY CONTINUES ACROSS CENTRAL GA THIS AFTERNOON. THE BOUNDARY WILL CONTINUE TO OOZE SOUTHWARD THROUGH THE EVENING. IN THE MID LEVELS...WV AND RAP ANALYSIS SHOWS A FAIRLY DECENT SHORTWAVE HELPING TO ENHANCE SHOWERS AND THUNDERSTORM DEVELOPMENT IN CENTRAL/EASTERN AL. THE SHORTWAVE WILL CONTINUE EASTWARD...SPREADING CONVECTION INTO NORTH CENTRAL GA AND WILL ALSO HELP PUSH THE OLD FRONT A LITTLE FURTHER SOUTH. SURFACE INSTABILITY IS GREATEST ALONG AND SOUTH OF THE FRONT BUT MID LEVEL LAPSE RATES REMAIN WEAK. WITH HIGH PWATS...MAIN HAZARDS FROM STORMS WILL BE LOCALLY HEAVY RAINFALL PLUS FREQUENT LIGHTNING. A FEW STRONG STORMS ARE POSSIBLE WITH GUSTY WINDS. THE FRONT SHOULD MOVE TO OVER THE SOUTHERN PORTION OF THE CWFA TONIGHT. WITH THE LOSS OF HEATING...CONVECTIVE COVERAGE SHOULD MOSTLY DIMINISH. MODELS ARE PROGGING ANOTHER GOOD SHORTWAVE TO MOVE EAST IN THE FLOW TOMORROW. THE DISTURBANCE WILL INTERACT WITH THE OLD BOUNDARY AND PRODUCE SCATTERED/ISOLD SHRA/TSRA AGAIN TOMORROW AFTERNOON. NLISTEMAA .LONG TERM /SUNDAY THROUGH FRIDAY/... MAINLY ONLY TWEAKS TO THE LONG TERM BASED ON THE LASTEST GUIDANCE. BDL PREVIOUS DISCUSSION... THE EXTENDED FORECAST START OFF WITH WEAKENING BOUNDARY ACROSS CENTRAL GA SUNDAY MOVING SOUTH. THE NEXT FRONTAL SYSTEM BEGINS TO MOVE INTO N GA MONDAY MORNING BUT THERE IS NOT MUCH MOISTURE ASSOCIATED WITH IT. THIS BOUNDARY WILL ACT AS A CATALYST FOR STORMS TO DEVELOP ACROSS THE AREA MONDAY AND TUESDAY BUT IT WILL ALSO USHER IN A MUCH DRIER AIRMASS TUESDAY NIGHT. THIS DRIER AIR IS EXPECTED TO STAY ACROSS THE REGION THROUGH THURSDAY WHICH WILL KEEP SHRA/TSRA ACTIVITY TO A MINIMUM. ALL IN ALL IT LOOKS LIKE WE MAY BE IN THE BEGINNING STAGES OF TRANSITIONING TO A MORE FALL LIKE PATTERN...WITH FRONTS MOVING THROUGH THE STATE GIVING THE CWA MOSTLY CLEAR SKIES FOR A FEW DAYS AND NOT STALLING ACROSS CENTRAL OR SOUTH GA. TEMPS REMAIN IN THE MID 80S TO MID 90S THROUGH THE EXTENDED. 01 && .AVIATION... 18Z UPDATE... CONVECTION HAS BEGUN DEVELOPING ACROSS THE AREA WITH KMCN AND KCSG ALONG MAIN LINE. SO FAR STORMS HAVE REMAINED SHOWERS BUT WE ARE EXPECTING THUNDERSTORMS ACROSS THE TAF SITES MAINLY 19-24Z. WINDS WILL BE NORTHWEST TO WEST AT 5-10KTS INITIALLY...DIMINISHING AFTER 00Z WITH THE LOOS OF HEATING. PATCHY FOG WILL DEVELOP IN THE USUAL SUSPECTS AND RAIN SOAKED AREAS BY DAYBREAK WITH MVFR VISIBILITIES. EXPECT CIGS IN MVFR/VFR RANGE THROUGH THE PERIOD. //ATL CONFIDENCE...18Z UPDATE... MEDIUM CONFIDENCE ON CIGS/TIMING OF TS MEDIUM TO HIGH ON ALL OTHER ELEMENTS. ATWELL && .PRELIMINARY POINT TEMPS/POPS... ATHENS 71 89 72 90 / 30 30 20 40 ATLANTA 73 89 73 89 / 20 30 20 40 BLAIRSVILLE 64 83 66 84 / 30 30 20 50 CARTERSVILLE 69 90 69 90 / 20 30 20 40 COLUMBUS 75 92 75 92 / 20 30 20 30 GAINESVILLE 71 86 71 87 / 30 30 20 50 MACON 73 93 74 92 / 30 30 20 40 ROME 69 89 70 90 / 20 20 20 30 PEACHTREE CITY 71 91 72 90 / 20 30 20 40 VIDALIA 75 93 74 92 / 30 30 20 50 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...NLISTEMAA LONG TERM....BDL AVIATION...NLISTEMAA
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
201 PM EDT FRI AUG 21 2015 .PREV DISCUSSION... /ISSUED 949 AM EDT FRI AUG 21 2015/ UPDATE... OLD FRONTAL BOUNDARY CURRENTLY DRAPED ACROSS CENTRAL GA THIS MORNING. IN THE MID LEVELS...A SHEAR AXIS IS SITUATED ALMOST DIRECTED ON TOP OF THE BOUNDARY. WV AND 500MB RAP ANALYSIS SHOWS A WEAK WAVE SHORTWAVE ASSOCIATED WITH THE SHOWERS ACROSS EASTERN GA THIS MORNING. THERE ARE TWO MORE SHORTWAVES ANALYZED IN THE FLOW...ONE ACROSS CENTRAL AL AND ANOTHER ACROSS THE ARKLAMISS. THE WAVE ACROSS CENTRAL AL SHOULD HELP SCT CONVECTION DEVELOP THIS AFTERNOON DURING PEAK HEATING ACROSS MUCH OF THE CWFA. HAVE UPDATED THE POPS ACCORDING TO THE LATEST RADAR TRENDS. HAVE ALSO TWEAKED THE AFTERNOON POPS A BIT TO COME A LITTLE MORE INTO LINE WITH THE HRRR...WHICH HAS A PRETTY GOOD HANDLE ON THE SHRA THAT ARE ONGOING. LOCALLY HEAVY RAINFALL AND FREQUENT LIGHTNING STRIKES ARE THE MAIN HAZARDS ASSOCIATED WITH ANY THUNDERSTORMS THIS AFTERNOON. PREV DISCUSSION... /ISSUED 414 AM EDT FRI AUG 21 2015/ SHORT TERM /TODAY THROUGH SATURDAY/... NAM/GFS/ECMWF IN VERY GOOD AGREEMENT THROUGH THE SHORT TERM. SURFACE TROUGH HAS STALLED ACROSS NORTH GEORGIA KEEPING MOST OF THE CWA IN THE WARM AND MOIST SECTOR. THIS TROUGH WILL NOT MOVE MUCH BUT SHOULD BE A FOCUS FOR CONVECTION THIS AFTERNOON AS A WEAK WAVE MOVES ALONG THE BOUNDARY. AFTER THIS WAVE MOVES TO OUR EAST...THE SURFACE TROUGH WILL SHIFT SOUTH. CAPES REMAIN IN THE 1500-2000 RANGE ALONG WITH PWATS RANGING FROM 1.8 TO 2.1 INCHES. WILL KEEP HIGH CHANCE POPS ACROSS NORTH AND PARTS OF CENTRAL GA WHERE THE DEEPEST MOISTURE WILL BE WITH CHANCE POPS ELSEWHERE. CONVECTION WILL DIMINISH QUICKLY THIS EVENING. ON SATURDAY EXPECT CONVECTION AGAIN ALTHOUGH WITH SLIGHTLY DRIER AIR OVER THE REGION WILL LIMIT POPS TO SLIGHT CHANCE TO CHANCE AND MAINLY DURING THE AFTERNOON. GUIDANCE TEMPS HAVE BEEN RUNNING 1 TO 2 DEGREES TOO LOW OVER THE PAST 10 DAYS AND HAVE THEREFORE RAISED MAX TEMPS BOTH DAYS BY A DEGREE OR TWO. 17 LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE EXTENDED FORECAST START OFF WITH WEAKENING BOUNDARY ACROSS CENTRAL GA SUNDAY MOVING SOUTH. THE NEXT FRONTAL SYSTEM BEGINS TO MOVE INTO N GA MONDAY MORNING BUT THERE IS NOT MUCH MOISTURE ASSOCIATED WITH IT. THIS BOUNDARY WILL ACT AS A CATALYST FOR STORMS TO DEVELOP ACROSS THE AREA MONDAY AND TUESDAY BUT IT WILL ALSO USHER IN A MUCH DRIER AIRMASS TUESDAY NIGHT. THIS DRIER AIR IS EXPECTED TO STAY ACROSS THE REGION THROUGH THURSDAY WHICH WILL KEEP SHRA/TSRA ACTIVITY TO A MINIMUM. ALL IN ALL IT LOOKS LIKE WE MAY BE IN THE BEGINNING STAGES OF TRANSITIONING TO A MORE FALL LIKE PATTERN...WITH FRONTS MOVING THROUGH THE STATE GIVING THE CWA MOSTLY CLEAR SKIES FOR A FEW DAYS AND NOT STALLING ACROSS CENTRAL OR SOUTH GA. TEMPS REMAIN IN THE MID 80S TO MID 90S THROUGH THE EXTENDED. 01 && .AVIATION... 18Z UPDATE... CONVECTION HAS BEGUN DEVELOPING ACROSS THE AREA WITH KMCN AND KCSG ALONG MAIN LINE. SO FAR STORMS HAVE REMAINED SHOWERS BUT WE ARE EXPECTING THUNDERSTORMS ACROSS THE TAF SITES MAINLY 19-24Z. WINDS WILL BE NORTHWEST TO WEST AT 5-10KTS INITIALLY...DIMINISHING AFTER 00Z WITH THE LOOS OF HEATING. PATCHY FOG WILL DEVELOP IN THE USUAL SUSPECTS AND RAIN SOAKED AREAS BY DAYBREAK WITH MVFR VISIBILITIES. EXPECT CIGS IN MVFR/VFR RANGE THROUGH THE PERIOD. //ATL CONFIDENCE...18Z UPDATE... MEDIUM CONFIDENCE ON CIGS/TIMING OF TS MEDIUM TO HIGH ON ALL OTHER ELEMENTS. ATWELL && .PRELIMINARY POINT TEMPS/POPS... ATHENS 90 71 89 71 / 50 50 30 20 ATLANTA 89 71 90 73 / 50 50 30 20 BLAIRSVILLE 82 65 84 63 / 40 40 30 20 CARTERSVILLE 89 69 91 69 / 40 50 30 10 COLUMBUS 91 74 93 75 / 40 40 20 20 GAINESVILLE 86 71 87 71 / 50 50 30 20 MACON 92 73 93 73 / 40 40 20 20 ROME 87 68 90 69 / 40 50 30 10 PEACHTREE CITY 89 70 91 71 / 50 50 30 20 VIDALIA 93 76 94 74 / 40 40 20 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...NLISTEMAA LONG TERM....BDL AVIATION...ATWELL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
121 PM CDT FRI AUG 21 2015 .SHORT TERM /TODAY/... ISSUED AT 346 AM CDT FRI AUG 21 2015 MAIN FORECAST CONCERN WAS FOCUSED ON TEMPERATURES AND WINDS FOR THIS AFTERNOON...AND WITH WEAK SHORTWAVE PROVIDING SOME ISOLATED SHOWERS/STORMS THROUGH THE MID-MORNING. A FEW ELEVATED SHOWERS/STORMS HAVE DEVELOPED OVER WEST-CENTRAL TO NORTHWEST IOWA AND LOOK TO MEANDER INTO NORTH-CENTRAL IOWA THROUGH 15Z THIS MORNING. THERE IS ENOUGH FORCING AND ELEVATED INSTABILITY...ALBEIT VERY WEAK...BUT ENOUGH TO WARRANT SLIGHT/LOW CHANCE POPS OVER THE NORTH. HOWEVER WITH A A STRONG CAP IN PLACE TODAY...IT WILL LIMIT ANYTHING PAST 15Z. THE LATEST 21.07Z HRRR HAS A DECENT HANDLE ON THE CONVECTIVE TRENDS AND LEANED TOWARD ITS SOLUTION FOR POPS/WX. STRONG MIXING AND WAA DEVELOP TODAY AS PRESSURE GRADIENT TIGHTENS THIS AFTERNOON. MIXING TO AROUND 850MB PUTS HIGHS IN THE LOWER 80S AND TWEAKED MAX TEMPS UP SLIGHTLY. THE MAV/ECS HAD A GREAT HANDLE ON TEMPS TODAY AS THE MET WAS TOO COLD THROUGHOUT THE FORECAST AREA. ALSO TWEAKED UP WINDS SLIGHTLY AS WINDS ATOP THE MIXED LAYER IN THE 25-30 KNOT RANGE. .LONG TERM /TONIGHT THROUGH THURSDAY/... ISSUED AT 346 AM CDT FRI AUG 21 2015 THE LONG TERM FORECAST IS CHARACTERIZED BY VARYING TEMPERATURES AND MOSTLY DRY CONDITIONS BUT PUNCTUATED AND HEADLINED BY THE STORM SYSTEM MOVING ACROSS THE REGION ON SATURDAY AND SATURDAY NIGHT. THE DRIVER FOR THIS SYSTEM WILL COME IN THE FORM OF A MID/UPPER LEVEL TROUGH...STRONG FOR THIS SEASON...MOVING ACROSS THE NORTHERN ROCKIES ON FRIDAY NIGHT AND OVER THE DAKOTAS AND MINNESOTA ON SATURDAY AND SATURDAY NIGHT. THIS WILL BE REFLECTED AT THE SURFACE BY A STEADILY STRENGTHENING TROUGH/FRONT...INITIALLY STRETCHING DOWN THE HIGH PLAINS AND THEN SWEEPING EAST/SOUTHEAST IN RESPONSE TO THE PROGRESSION OF THE MID/UPPER TROUGH ON SATURDAY/SATURDAY NIGHT. AHEAD OF THIS SYSTEM MOST OF SATURDAY WILL BE WARM AND INCREASINGLY BREEZY ACROSS OUR FORECAST AREA AS THE SURFACE PRESSURE GRADIENT TIGHTENS UP BETWEEN THE HIGH PLAINS TROUGH AND A LARGE HIGH PRESSURE AREA DEPARTING TO THE EAST. FOR MUCH OF THE DAY THINGS WILL REMAIN QUIET...BUT BY PEAK HEATING IN THE LATE AFTERNOON/EVENING INSTABILITY WILL BE MAXIMIZED AND THE SURFACE FRONT WILL SERVE AS A MECHANISM FOR THUNDERSTORM DEVELOPMENT COINCIDENT WITH THE ARRIVAL OF STRONGER FORCING AND WIND FIELDS ALOFT GIVEN THE APPROACH OF THE MID/UPPER TROUGH. INITIAL STORMS WILL LIKELY BE ORGANIZED WITHIN THIS ENVIRONMENT PROVIDING A FAIRLY SUBSTANTIAL SEVERE WEATHER THREAT...THEN AS THE SYSTEM MOVES EAST/SOUTHEAST WITH SUNSET THE STORMS SHOULD BECOME MORE LINEAR AND GRADUALLY DIMINISH IN INTENSITY BY THE TIME THEY REACH EASTERN IOWA. FOR NOW THE PRIMARY QUESTIONS ARE WHERE THE STORMS WILL INITIALLY DEVELOP...OVER SOUTH DAKOTA/MINNESOTA/NEBRASKA OR OVER WESTERN/NORTHWESTERN IOWA...AND HOW FAR EAST/SOUTHEAST THEY WILL REMAIN SEVERE AS THEY MOVE QUICKLY ACROSS THE STATE. SPC PRODUCTS HANDLE THE THREAT WELL AND WILL BE CLOSELY MONITORED TODAY AND TOMORROW. AFTER THE FRONT AND ASSOCIATED STORMS BLOW THROUGH ON SATURDAY NIGHT WE WILL ONCE AGAIN SEE MOSTLY CLEAR...COOL...AND BREEZY WEATHER FROM SUNDAY INTO EARLY NEXT WEEK. BY MONDAY THE 500 MB PATTERN WILL FEATURE A DEEPENING GYRE OVER THE GREAT LAKES REGION...THAT BEING THE SYSTEM THAT AFFECTED US ON SATURDAY/SATURDAY NIGHT...WITH A DEVELOPING RIDGE OVER THE FOUR CORNERS REGION. INITIALLY THIS WILL PLACE IOWA BENEATH PERSISTENT NORTHWEST FLOW RESULTING IN A VERY SLOW WARMING TREND. BY MIDWEEK AS THE EASTERN GYRE DEPARTS THE WESTERN RIDGE WILL BUILD FURTHER AND APPROACH OUR AREA...BUT MOST OF THE HEAT BUBBLE SHOULD REMAIN WEST/SOUTHWEST OF IOWA THROUGH AT LEAST WEDNESDAY. THERE ARE CONSISTENT INDICATIONS THAT A SHORTWAVE WILL OVERTOP THE 500 MB RIDGE SOMETIME AROUND THURSDAY...POSSIBLY PROVIDING US WITH ANOTHER CHANCE FOR RAIN BUT MORE IMPORTANTLY SHUNTING THE RIDGE SOUTHWARD FOR A DAY OR TWO. BEYOND THIS...LOOKING TOWARD THE NEXT WEEKEND OR SO...IT REMAINS UNCERTAIN WHETHER THE LARGE RIDGE WILL BE ABLE TO BUILD UP OVER THE MIDWEST OR WILL REMAIN JUST TO OUR SOUTHWEST. THIS WILL DETERMINE WHETHER WE GET ONE LAST BLAST OF SUMMER HEAT OR NOT. && .AVIATION...21/18Z ISSUED AT 119 PM CDT FRI AUG 21 2015 GENERALLY VFR CONDITIONS THROUGH THE PERIOD. LOW POTENTIAL FOR STRATUS DEVELOPING OVERNIGHT HOWEVER WINDS SHOULD REMAIN STRONG ENOUGH TO KEEP THIS POTENTIAL AT A MINIMUM. OTHERWISE BREEZY SOUTHERLY WINDS TODAY DIMINISHING OVERNIGHT THEN INCREASING AGAIN SATURDAY MORNING. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...LEE AVIATION...DONAVON
AREA FORECAST DISCUSSION
NWS GOODLAND KS
241 PM MDT FRI AUG 21 2015 .UPDATE... ISSUED AT 1003 AM MDT FRI AUG 21 2015 CURRENT FORECAST FOR THE AFTERNOON AND EVENING LOOKS ON TRACK WITH THE LATEST OBSERVATIONS AND MODEL DATA. DID ADJUST THE COVERAGE AND VALUE OF THE RAINFALL CHANCES A BIT GIVEN THE GOOD AGREEMENT AMONG THE MODELS FOR THE STORM ACTIVITY THIS AFTERNOON. EXPECT STORMS TO DEVELOP ALONG A SURFACE TROUGH/DRY LINE OVER THE WESTERN PART OF THE AREA. THE STRONGEST LIFT WILL REMAIN TIED TO THE NEARLY STATIONARY TROUGH THROUGH THE AFTERNOON...SO EXPECT STORMS TO DEVELOP ALONG IT AND MOVE SLOWLY EAST. THE MAIN QUESTION WILL BE HOW FAR EAST WILL THE STORMS GO BEFORE DISSIPATING SINCE THE MAJORITY OF THE LIFT WILL REMAIN WITH THE SURFACE TROUGH. CURRENTLY LOOKS LIKE THE MAJORITY OF THE STORMS WILL WEAKEN BY THE TIME THEY REACH THE HIGHWAY 83 CORRIDOR...ALTHOUGH STORMS WHICH MOVE OVER SOUTHWEST NEBRASKA MAY MAKE IT ALL THE WAY THROUGH RED WILLOW COUNTY BEFORE DISSIPATING. FOR THE EVENING AM NOT TOO CONFIDENT REGARDING STORMS EAST OF HIGHWAY 25. AM THINKING ONCE THE SURFACE HEATING ENDS THE NOSE OF THE LOW LEVEL JET WILL SERVE AS THE PRIMARY TRIGGER FOR STORMS...WHICH WILL BE PRIMARILY WEST OF HIGHWAY 27. HOWEVER SOUNDINGS INDICATE A FAIRLY DRY ENVIRONMENT DURING THE EVENING WEST OF HIGHWAY 27...WHICH MAY HINDER STORM DEVELOPMENT DESPITE THE INFLUENCE OF THE NOSE OF THE LOW LEVEL JET. ASIDE FROM THE STORMS DID INCREASE THE WINDS DUE TO THE STRENGTHENING LOW LEVEL JET IN THE AFTERNOON MIXING TO THE GROUND. WEST OF THE SURFACE TROUGH THE WINDS WILL BE LIGHT DUE TO THE LOW. && .SHORT TERM...(TODAY THROUGH SUNDAY NIGHT) ISSUED AT 330 AM MDT FRI AUG 21 2015 FORECAST CONCERNS WILL BE THUNDERSTORM CHANCES INTO THE BEGINNING OF THE WEEKEND AND HOW COOL TO MAKE IT SATURDAY NIGHT INTO SUNDAY NIGHT. SATELLITE SHOWING AN AMPLIFIED/BLOCKY OVER THE PACIFIC. THIS TRANSITIONS TO A BROAD TROUGH/WESTERLY ALOFT OVER MOST OF THE COUNTRY. STRONG SYSTEM DIGGING INTO SOUTHWEST CANADA WITH SEVERAL SHORTWAVE TROUGHS EMBEDDED IN THE WESTERLY FLOW. AT JET LEVEL...MODELS DID WELL. AT MID LEVELS...THE GFS/CANADIAN AND THE UKMET WERE DOING A LITTLE BETTER THAN THE ECMWF. THE SREF AND ESPECIALLY THE NAM WERE NOT DOING WELL. THE GFS WAS DOING A LITTLE BETTER THAN THE ECMWF WITH THE LOW LEVEL WIND FIELD. ALL MODELS INITIALIZED WELL ON THE LOW LEVEL THERMAL FIELD DIFFICULT AND UNCERTAIN PRECIPITATION FORECAST...ESPECIALLY THROUGH THIS EVENING. CONFIDENCE IS BELOW AVERAGE FOR THE PRECIPITATION FORECAST. TODAY/TONIGHT...WILL HAVE TO KEEP AN EYE ON ANY LATE NIGHT/EARLY MORNING DEVELOPMENT NEAR THE BOUNDARY JUST TO THE NORTH OF OUR AREA. MODELS HAVE BEEN HINTING AT IT AND WILL CONTINUE TO MONITOR. FOR YESTERDAYS THUNDERSTORMS...JUST ENOUGH MOISTURE ALONG A BOUNDARY WITH A WEAK SHORTWAVE TROUGH WAS ABLE TO SPARK ISOLATED THUNDERSTORMS OVER AND NEAR THE NORTHEAST PORTION OF THE AREA. NOT TOO DIFFERENT A SETUP FOR TODAY FROM YESTERDAY. AGAIN WHAT MAKES FORECAST UNCERTAIN IS THE MOISTURE AVAILABILITY...ESPECIALLY ABOVE THE LOW LEVELS...WHERE DOES THE SURFACE TROUGH SETUP AND THE WEAK/COMPLICATED MID LEVEL FORCING INVOLVED. MODELS HAVE THE BOUNDARY PRETTY CLOSE BUT A LITTLE FURTHER WEST THAN WHAT WAS SHOWN YESTERDAY. 700 MB SHORTWAVE EJECTS INTO THE PLAINS THIS AFTERNOON AND IT LOOKS TO BE IN TWO PIECES. ONE PORTION GOES ACROSS THE NORTH AND IS THE SLOWER OF THE TWO SHORTWAVE TROUGHS. THE SECOND ONE GOES ACROSS TO OUR SOUTH AND BRUSHES THE SOUTHERN PORTION OF THE AREA. THERE IS WEAK FORCING IN BETWEEN. ALSO THE MODELS DIFFER ON HOW FAR EAST DURING THE DAY THEY MOVE THESE SHORTWAVE TROUGHS. CONVECTIVE ALLOWING MODELS ARE HAVING A DIFFICULT WITH ALL THIS. THE ARW HAS LITTLE TO NOTHING. THE HRRR AND ESPECIALLY THE NMM DEVELOP ROBUST CONVECTION OVER THE WESTERN PORTION OF THE AREA THIS AFTERNOON CLOSE TO THE SURFACE TROUGH. THE 00Z NAM DID NOT INDICATE ANYTHING BUT NOW THE 06Z NAM IS MATCHING UP WITH THE ABOVE TWO MODELS. THE 00Z ECMWF EXPLODES CONVECTION OVER THE NORTHERN PORTION OF THE AREA. ALL THIS TIME A RATHER STOUT EML LIES OVER THE AREA. AFTER LOOKING AT THIS AND COLLABORATION...PULLED THE INITIATION A LITTLE FURTHER WEST THAN BEFORE. THE PROBLEM THEN BECOMES HOW FAR EAST TO TAKE THIS ACTIVITY. THE HRRR TAKES IT FURTHER EAST WHILE THE REST OF THE OUTPUT THAT DID DEVELOP SOMETHING JUST KEEPS IT OVER THE WEST AS IT EITHER DISSIPATES THE THUNDERSTORMS OR MOVES THEM OF THE AREA TO THE NORTH OR SOUTH. SO DID LOWER POPS A LITTLE DUE TO THIS. IT DOES LOOK LIKE THE THUNDERSTORMS END BY 06Z. HOWEVER ELEVATED STORMS/REDEVELOPMENT WILL NEED TO BE LOOKED AT AGAIN TO A LOW LEVEL JET AND DECENT WARM AIR ADVECTION PATTERN ALOFT AHEAD OF ANOTHER SHORTWAVE TROUGH. FOR THIS AFTERNOON AND EVENINGS CONVECTION...IF STORMS DEVELOP...IT WILL BE POSSIBLE THAT THESE WILL BECOME SEVERE DUE TO THE INSTABILITY AND LAPSE RATES INVOLVED. NO MATTER IF STORMS DEVELOP OR NOT...BOUNDARY LAYER MOISTURE INCREASES AND AT THE VERY LEAST A LOT OF STRATUS WILL DEVELOP WITH SOME PATCHY FOG INVOLVED. PRESSURE FALLS AND GRADIENT SUPPORT NEAR BREEZY OR BREEZY CONDITIONS. GUIDANCE HAS BEEN RUNNING COOL ON MAXES HERE THE LAST FEW DAYS. THE GFS/MAV HAS BEEN DOING THE BEST AND HAVE RAISED THE MAXES SOME. SATURDAY/SATURDAY NIGHT...PATCHY FOG ENDS BY MID MORNING WITH THE STRATUS LASTING A LITTLE LONGER. THERE ARE STILL DIFFERENCES IN HOW FAST THE MODELS BRING IN THE COLD FRONT. THE NAM IS THE SLOWEST FOLLOWED BY SREF. THE GFS/ECMWF/CANADIAN ARE THE FASTEST. ROUGHLY IT LOOKS LIKE THE FRONT IS THROUGH THE NORTHWEST HALF OF THE AREA BY LATE MORNING. THE FRONT THEN LOOKS TO MOVE ACROSS THE REST OF THE AREA BY LATE AFTERNOON OR EARLY EVENING. THE CHANCE OF THUNDERSTORMS WILL BE OVER THE SOUTHEAST PORTION OF THE AREA IN ADVANCE OF THIS FRONT. CONTINUED THE LOW CHANCE POPS IN THIS AREA. FRONT AND ASSOCIATED FORCING EXIT THE AREA EARLY IN THE EVENING AND SO PRECIPITATION CUTS OFF RATHER FAST. WINDS BEHIND THE FRONT COULD GET WINDY AND THE DAY SHIFT WILL NEED TO LOOK AT RAISING THE WINDS EVEN MORE. DESPITE SIMILAR TIMING TO YESTERDAYS OUTPUT...MODELS HAVE RAISED HIGH TEMPERATURES FOR THE DAY. THE GFS...CANADIAN AND THE NAM ARE IN DECENT AGREEMENT ON THIS. IT SEEMS THAT THE COLDER AIR DOES LAG SLIGHTLY BEHIND THE FRONT. DID RAISE MAXES A LITTLE BUT THEY MAY NEED TO BE RAISED EVEN MORE IN SOUTHERN LOCATIONS. WINDS STAY UP ENOUGH TONIGHT THAT TEMPERATURES SHOULD NOT DROP LIKE A ROCK. IF THE WINDS LET UP QUICKER...GOOD RADIATIONAL CONDITIONS WOULD BE IN PLACE AND A LOWERING OF THE MINS WOULD BE NEEDED. SUNDAY/SUNDAY NIGHT...DRY PERIOD WITH POST FRONTAL COOL AIR MASS IN PLACE. NEW GUIDANCE FOR TEMPERATURES VERY SIMILAR TO WHAT WAS IN THERE FOR MAXES AND MADE ONLY SLIGHT ADJUSTMENTS. ONCE AGAIN FOR THE MINS...IF WINDS END UP BEING LESS THAN CURRENTLY PREDICTED ADDITIONAL COOLING WILL BE NEEDED. .LONG TERM...(SATURDAY THROUGH FRIDAY) ISSUED AT 241 PM MDT FRI AUG 21 2015 FOR THIS RUN OF THE EXTENDED FORECAST...THE PRIMARY SENSIBLE WEATHER TO FOCUS ON WILL BE SATURDAY INTO SATURDAY NIGHT AS A COLD FRONT PASSES AND THUNDERSTORM DEVELOPMENT OCCURS. BEGINNING SATURDAY MORNING...A COLD FRONT SHOULD BEGIN SLIDING INTO THE FORECAST AREA. AHEAD OF THE FRONT...AMPLE MIXING WILL LEAD TO A FAST RISE IN THE TEMPERATURES BEFORE THE FRONT MOVES THROUGH. THEREFORE...HIGH TEMPERATURE FORECAST IS TRICKY BECAUSE OF QUESTIONS ON THE DEGREE OF WARMING AND FRONT TIMING. AHEAD OF THE COLD FRONT...A MOIST AND UNSTABLE AIRMASS WILL BE IN PLACE. THE STORM ENVIRONMENT SHOULD BE CHARACTERIZED BY SBCAPE OF 2000-3500 J/KG...850-500 MB LAPSE RATES OF 8-9 C/KM...0-6 KM BULK SHEAR NEAR 30 KTS...INCREASING IN THE EVENING. THIS MEANS A FEW STRONG/SEVERE STORMS ARE POSSIBLE AHEAD OF THE FRONT. THE LOCATIONS UNDER THE HIGHEST THREAT FOR STORMS/SEVERE WEATHER LIE ALONG AND SOUTH OF A LINE FROM HILL CITY KANSAS TO OAKLEY TO KIT CARSON COLORADO. THE PRIMARY THREATS WILL BE LARGE HAIL AND DAMAGING WINDS. WEAK SHEAR INDICATE STORMS MAY BE PULSE-LIKE IN NATURE BUT SOME ORGANIZATION IS LIKELY...SIMILAR TO TODAY`S ACTIVITY. ANOTHER ITEM TO NOTE IS THAT STORM MOVEMENT SHOULD BE ROUGHLY PARALLEL TO THE FRONT. THIS MAY LEAD TO A FLASH FLOODING THREAT IF STORMS TRAIN ALONG THE EAST/WEST ORIENTED COLD FRONT. STORMS SHOULD EXIT THE REGION DURING THE EVENING AS THE FRONT CONTINUES ITS SOUTHWARD PUSH. FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT...BELOW NORMAL TEMPERATURES AND DRY WEATHER CAN BE ANTICIPATED. IN FACT...WE WILL LIKELY OBSERVE A FEW LOW TEMPERATURES IN THE UPPER 40S BOTH SATURDAY AND SUNDAY NIGHTS. THIS IS SIMILAR TO THE COLD FRONT THAT PASSED THROUGH IN RECENT DAYS. IN ADDITION TO COOLER WEATHER...VERY DRY AIR ADVECTS IN FROM THE NORTHWEST. DRY AIR IS ALREADY IN PLACE ACCORDING TO OBSERVATIONS ACROSS NORTHEAST COLORADO...WYOMING AND MONTANA. THIS FURTHERS CONFIDENCE IN COOL TEMPERATURES WITH CLEAR SKIES OVERHEAD AND LIGHT WINDS DUE TO A PASSING SURFACE HIGH PRESSURE. A WARMING TREND BEGINS MONDAY AS AN UPPER LEVEL RIDGE BUILDS OVER THE REGION. WITH THE RIDGE OF HIGH PRESSURE IN PLACE AND NO APPRECIABLE SHORTWAVE TROUGHS ROUNDING THE RIDGE...WENT WITH A DRY FORECAST. A FEW STORMS MAY SNEAK INTO EAST COLORADO TUESDAY EVENING BUT MOST ACTIVITY SHOULD REMAIN CONFINED TO THE COLORADO FRONT RANGE. WEDNESDAY AND BEYOND...GUIDANCE DISAGREEMENT AND UNCERTAINTY REGARDING SHORTWAVE TROUGH POTENTIAL AND HIGH PRESSURE RIDGE STRENGTH REDUCE FORECAST CONFIDENCE IN PRECIPITATION CHANCES. MAINTAINED CR_INITIALIZATION POPS WHICH SEEMED REASONABLE GIVEN THIS TIME OF YEAR. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1136 AM MDT FRI AUG 21 2015 VFR CONDITIONS EXPECTED FOR THE 18Z TAFS. SOUTH WINDS WILL INCREASE THROUGH THE AFTERNOON THEN DECLINE SOME DURING THE EVENING. SCATTERED STORMS WILL MOVE EAST ACROSS THE AREA AND BE MOST LIKELY TO IMPACT KGLD RATHER THAN KMCK LATE THIS AFTERNOON INTO THE EVENING. MINOR FOG MAY DEVELOP OVERNIGHT INTO EARLY MORNING FOR BOTH SITES. AT THIS TIME KGLD LOOKS MORE FAVORABLE FOR FOG THAN KMCK. SATURDAY WINDS WILL TURN TO THE WEST THEN NORTHWEST AHEAD OF A COLD FRONT. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JTL SHORT TERM...BULLER LONG TERM...RRH AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1141 AM MDT FRI AUG 21 2015 .UPDATE... ISSUED AT 1003 AM MDT FRI AUG 21 2015 CURRENT FORECAST FOR THE AFTERNOON AND EVENING LOOKS ON TRACK WITH THE LATEST OBSERVATIONS AND MODEL DATA. DID ADJUST THE COVERAGE AND VALUE OF THE RAINFALL CHANCES A BIT GIVEN THE GOOD AGREEMENT AMONG THE MODELS FOR THE STORM ACTIVITY THIS AFTERNOON. EXPECT STORMS TO DEVELOP ALONG A SURFACE TROUGH/DRY LINE OVER THE WESTERN PART OF THE AREA. THE STRONGEST LIFT WILL REMAIN TIED TO THE NEARLY STATIONARY TROUGH THROUGH THE AFTERNOON...SO EXPECT STORMS TO DEVELOP ALONG IT AND MOVE SLOWLY EAST. THE MAIN QUESTION WILL BE HOW FAR EAST WILL THE STORMS GO BEFORE DISSIPATING SINCE THE MAJORITY OF THE LIFT WILL REMAIN WITH THE SURFACE TROUGH. CURRENTLY LOOKS LIKE THE MAJORITY OF THE STORMS WILL WEAKEN BY THE TIME THEY REACH THE HIGHWAY 83 CORRIDOR...ALTHOUGH STORMS WHICH MOVE OVER SOUTHWEST NEBRASKA MAY MAKE IT ALL THE WAY THROUGH RED WILLOW COUNTY BEFORE DISSIPATING. FOR THE EVENING AM NOT TOO CONFIDENT REGARDING STORMS EAST OF HIGHWAY 25. AM THINKING ONCE THE SURFACE HEATING ENDS THE NOSE OF THE LOW LEVEL JET WILL SERVE AS THE PRIMARY TRIGGER FOR STORMS...WHICH WILL BE PRIMARILY WEST OF HIGHWAY 27. HOWEVER SOUNDINGS INDICATE A FAIRLY DRY ENVIRONMENT DURING THE EVENING WEST OF HIGHWAY 27...WHICH MAY HINDER STORM DEVELOPMENT DESPITE THE INFLUENCE OF THE NOSE OF THE LOW LEVEL JET. ASIDE FROM THE STORMS DID INCREASE THE WINDS DUE TO THE STRENGTHENING LOW LEVEL JET IN THE AFTERNOON MIXING TO THE GROUND. WEST OF THE SURFACE TROUGH THE WINDS WILL BE LIGHT DUE TO THE LOW. && .SHORT TERM...(TODAY THROUGH SUNDAY NIGHT) ISSUED AT 330 AM MDT FRI AUG 21 2015 FORECAST CONCERNS WILL BE THUNDERSTORM CHANCES INTO THE BEGINNING OF THE WEEKEND AND HOW COOL TO MAKE IT SATURDAY NIGHT INTO SUNDAY NIGHT. SATELLITE SHOWING AN AMPLIFIED/BLOCKY OVER THE PACIFIC. THIS TRANSITIONS TO A BROAD TROUGH/WESTERLY ALOFT OVER MOST OF THE COUNTRY. STRONG SYSTEM DIGGING INTO SOUTHWEST CANADA WITH SEVERAL SHORTWAVE TROUGHS EMBEDDED IN THE WESTERLY FLOW. AT JET LEVEL...MODELS DID WELL. AT MID LEVELS...THE GFS/CANADIAN AND THE UKMET WERE DOING A LITTLE BETTER THAN THE ECMWF. THE SREF AND ESPECIALLY THE NAM WERE NOT DOING WELL. THE GFS WAS DOING A LITTLE BETTER THAN THE ECMWF WITH THE LOW LEVEL WIND FIELD. ALL MODELS INITIALIZED WELL ON THE LOW LEVEL THERMAL FIELD DIFFICULT AND UNCERTAIN PRECIPITATION FORECAST...ESPECIALLY THROUGH THIS EVENING. CONFIDENCE IS BELOW AVERAGE FOR THE PRECIPITATION FORECAST. TODAY/TONIGHT...WILL HAVE TO KEEP AN EYE ON ANY LATE NIGHT/EARLY MORNING DEVELOPMENT NEAR THE BOUNDARY JUST TO THE NORTH OF OUR AREA. MODELS HAVE BEEN HINTING AT IT AND WILL CONTINUE TO MONITOR. FOR YESTERDAYS THUNDERSTORMS...JUST ENOUGH MOISTURE ALONG A BOUNDARY WITH A WEAK SHORTWAVE TROUGH WAS ABLE TO SPARK ISOLATED THUNDERSTORMS OVER AND NEAR THE NORTHEAST PORTION OF THE AREA. NOT TOO DIFFERENT A SETUP FOR TODAY FROM YESTERDAY. AGAIN WHAT MAKES FORECAST UNCERTAIN IS THE MOISTURE AVAILABILITY...ESPECIALLY ABOVE THE LOW LEVELS...WHERE DOES THE SURFACE TROUGH SETUP AND THE WEAK/COMPLICATED MID LEVEL FORCING INVOLVED. MODELS HAVE THE BOUNDARY PRETTY CLOSE BUT A LITTLE FURTHER WEST THAN WHAT WAS SHOWN YESTERDAY. 700 MB SHORTWAVE EJECTS INTO THE PLAINS THIS AFTERNOON AND IT LOOKS TO BE IN TWO PIECES. ONE PORTION GOES ACROSS THE NORTH AND IS THE SLOWER OF THE TWO SHORTWAVE TROUGHS. THE SECOND ONE GOES ACROSS TO OUR SOUTH AND BRUSHES THE SOUTHERN PORTION OF THE AREA. THERE IS WEAK FORCING IN BETWEEN. ALSO THE MODELS DIFFER ON HOW FAR EAST DURING THE DAY THEY MOVE THESE SHORTWAVE TROUGHS. CONVECTIVE ALLOWING MODELS ARE HAVING A DIFFICULT WITH ALL THIS. THE ARW HAS LITTLE TO NOTHING. THE HRRR AND ESPECIALLY THE NMM DEVELOP ROBUST CONVECTION OVER THE WESTERN PORTION OF THE AREA THIS AFTERNOON CLOSE TO THE SURFACE TROUGH. THE 00Z NAM DID NOT INDICATE ANYTHING BUT NOW THE 06Z NAM IS MATCHING UP WITH THE ABOVE TWO MODELS. THE 00Z ECMWF EXPLODES CONVECTION OVER THE NORTHERN PORTION OF THE AREA. ALL THIS TIME A RATHER STOUT EML LIES OVER THE AREA. AFTER LOOKING AT THIS AND COLLABORATION...PULLED THE INITIATION A LITTLE FURTHER WEST THAN BEFORE. THE PROBLEM THEN BECOMES HOW FAR EAST TO TAKE THIS ACTIVITY. THE HRRR TAKES IT FURTHER EAST WHILE THE REST OF THE OUTPUT THAT DID DEVELOP SOMETHING JUST KEEPS IT OVER THE WEST AS IT EITHER DISSIPATES THE THUNDERSTORMS OR MOVES THEM OF THE AREA TO THE NORTH OR SOUTH. SO DID LOWER POPS A LITTLE DUE TO THIS. IT DOES LOOK LIKE THE THUNDERSTORMS END BY 06Z. HOWEVER ELEVATED STORMS/REDEVELOPMENT WILL NEED TO BE LOOKED AT AGAIN TO A LOW LEVEL JET AND DECENT WARM AIR ADVECTION PATTERN ALOFT AHEAD OF ANOTHER SHORTWAVE TROUGH. FOR THIS AFTERNOON AND EVENINGS CONVECTION...IF STORMS DEVELOP...IT WILL BE POSSIBLE THAT THESE WILL BECOME SEVERE DUE TO THE INSTABILITY AND LAPSE RATES INVOLVED. NO MATTER IF STORMS DEVELOP OR NOT...BOUNDARY LAYER MOISTURE INCREASES AND AT THE VERY LEAST A LOT OF STRATUS WILL DEVELOP WITH SOME PATCHY FOG INVOLVED. PRESSURE FALLS AND GRADIENT SUPPORT NEAR BREEZY OR BREEZY CONDITIONS. GUIDANCE HAS BEEN RUNNING COOL ON MAXES HERE THE LAST FEW DAYS. THE GFS/MAV HAS BEEN DOING THE BEST AND HAVE RAISED THE MAXES SOME. SATURDAY/SATURDAY NIGHT...PATCHY FOG ENDS BY MID MORNING WITH THE STRATUS LASTING A LITTLE LONGER. THERE ARE STILL DIFFERENCES IN HOW FAST THE MODELS BRING IN THE COLD FRONT. THE NAM IS THE SLOWEST FOLLOWED BY SREF. THE GFS/ECMWF/CANADIAN ARE THE FASTEST. ROUGHLY IT LOOKS LIKE THE FRONT IS THROUGH THE NORTHWEST HALF OF THE AREA BY LATE MORNING. THE FRONT THEN LOOKS TO MOVE ACROSS THE REST OF THE AREA BY LATE AFTERNOON OR EARLY EVENING. THE CHANCE OF THUNDERSTORMS WILL BE OVER THE SOUTHEAST PORTION OF THE AREA IN ADVANCE OF THIS FRONT. CONTINUED THE LOW CHANCE POPS IN THIS AREA. FRONT AND ASSOCIATED FORCING EXIT THE AREA EARLY IN THE EVENING AND SO PRECIPITATION CUTS OFF RATHER FAST. WINDS BEHIND THE FRONT COULD GET WINDY AND THE DAY SHIFT WILL NEED TO LOOK AT RAISING THE WINDS EVEN MORE. DESPITE SIMILAR TIMING TO YESTERDAYS OUTPUT...MODELS HAVE RAISED HIGH TEMPERATURES FOR THE DAY. THE GFS...CANADIAN AND THE NAM ARE IN DECENT AGREEMENT ON THIS. IT SEEMS THAT THE COLDER AIR DOES LAG SLIGHTLY BEHIND THE FRONT. DID RAISE MAXES A LITTLE BUT THEY MAY NEED TO BE RAISED EVEN MORE IN SOUTHERN LOCATIONS. WINDS STAY UP ENOUGH TONIGHT THAT TEMPERATURES SHOULD NOT DROP LIKE A ROCK. IF THE WINDS LET UP QUICKER...GOOD RADIATIONAL CONDITIONS WOULD BE IN PLACE AND A LOWERING OF THE MINS WOULD BE NEEDED. SUNDAY/SUNDAY NIGHT...DRY PERIOD WITH POST FRONTAL COOL AIR MASS IN PLACE. NEW GUIDANCE FOR TEMPERATURES VERY SIMILAR TO WHAT WAS IN THERE FOR MAXES AND MADE ONLY SLIGHT ADJUSTMENTS. ONCE AGAIN FOR THE MINS...IF WINDS END UP BEING LESS THAN CURRENTLY PREDICTED ADDITIONAL COOLING WILL BE NEEDED. .LONG TERM...(MONDAY THROUGH THURSDAY) ISSUED AT 330 AM MDT FRI AUG 21 2015 THE EXTENDED PERIOD LOOKS TO BE MOSTLY DRY ALONG WITH NEAR TO ABOVE NORMAL TEMPERATURES FOR THE AREA AS RIDGING INFLUENCES THE FORECAST. ON MONDAY...AN UPPER LEVEL RIDGE CONTINUES TO BUILD INTO THE PLAINS FOLLOWING THE SYSTEM PREDICTED TO IMPACT THE REGION THIS WEEKEND. THE RIDGE AMPLIFIES AND MOVES EAST EARLY NEXT WEEK...WITH ITS AXIS NEARING THE PLAINS ON WEDNESDAY. DRY CONDITIONS ARE EXPECTED DURING THIS TIME FRAME. MOISTURE RETURNS TO THE AREA WEDNESDAY AND THURSDAY AS A SHORTWAVE MOVES ALONG THE PERSISTENT RIDGE. THIS DISTURBANCE LOOKS TO GENERATE SHOWER AND THUNDERSTORM CHANCES WEDNESDAY NIGHT AND THURSDAY FOR PORTIONS OF THE REGION. AFTER SUNDAYS COOL DOWN...TEMPERATURES ARE EXPECTED TO QUICKLY REBOUND IN THE EXTENDED PERIOD WITH HIGHS IN THE UPPER 80S TO LOW 90S AND LOWS IN THE UPPER 50S TO UPPER 60S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1136 AM MDT FRI AUG 21 2015 VFR CONDITIONS EXPECTED FOR THE 18Z TAFS. SOUTH WINDS WILL INCREASE THROUGH THE AFTERNOON THEN DECLINE SOME DURING THE EVENING. SCATTERED STORMS WILL MOVE EAST ACROSS THE AREA AND BE MOST LIKELY TO IMPACT KGLD RATHER THAN KMCK LATE THIS AFTERNOON INTO THE EVENING. MINOR FOG MAY DEVELOP OVERNIGHT INTO EARLY MORNING FOR BOTH SITES. AT THIS TIME KGLD LOOKS MORE FAVORABLE FOR FOG THAN KMCK. SATURDAY WINDS WILL TURN TO THE WEST THEN NORTHWEST AHEAD OF A COLD FRONT. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JTL SHORT TERM...BULLER LONG TERM...JBH AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1019 AM MDT FRI AUG 21 2015 .UPDATE... ISSUED AT 1003 AM MDT FRI AUG 21 2015 CURRENT FORECAST FOR THE AFTERNOON AND EVENING LOOKS ON TRACK WITH THE LATEST OBSERVATIONS AND MODEL DATA. DID ADJUST THE COVERAGE AND VALUE OF THE RAINFALL CHANCES A BIT GIVEN THE GOOD AGREEMENT AMONG THE MODELS FOR THE STORM ACTIVITY THIS AFTERNOON. EXPECT STORMS TO DEVELOP ALONG A SURFACE TROUGH/DRY LINE OVER THE WESTERN PART OF THE AREA. THE STRONGEST LIFT WILL REMAIN TIED TO THE NEARLY STATIONARY TROUGH THROUGH THE AFTERNOON...SO EXPECT STORMS TO DEVELOP ALONG IT AND MOVE SLOWLY EAST. THE MAIN QUESTION WILL BE HOW FAR EAST WILL THE STORMS GO BEFORE DISSIPATING SINCE THE MAJORITY OF THE LIFT WILL REMAIN WITH THE SURFACE TROUGH. CURRENTLY LOOKS LIKE THE MAJORITY OF THE STORMS WILL WEAKEN BY THE TIME THEY REACH THE HIGHWAY 83 CORRIDOR...ALTHOUGH STORMS WHICH MOVE OVER SOUTHWEST NEBRASKA MAY MAKE IT ALL THE WAY THROUGH RED WILLOW COUNTY BEFORE DISSIPATING. FOR THE EVENING AM NOT TOO CONFIDENT REGARDING STORMS EAST OF HIGHWAY 25. AM THINKING ONCE THE SURFACE HEATING ENDS THE NOSE OF THE LOW LEVEL JET WILL SERVE AS THE PRIMARY TRIGGER FOR STORMS...WHICH WILL BE PRIMARILY WEST OF HIGHWAY 27. HOWEVER SOUNDINGS INDICATE A FAIRLY DRY ENVIRONMENT DURING THE EVENING WEST OF HIGHWAY 27...WHICH MAY HINDER STORM DEVELOPMENT DESPITE THE INFLUENCE OF THE NOSE OF THE LOW LEVEL JET. ASIDE FROM THE STORMS DID INCREASE THE WINDS DUE TO THE STRENGTHENING LOW LEVEL JET IN THE AFTERNOON MIXING TO THE GROUND. WEST OF THE SURFACE TROUGH THE WINDS WILL BE LIGHT DUE TO THE LOW. && .SHORT TERM...(TODAY THROUGH SUNDAY NIGHT) ISSUED AT 330 AM MDT FRI AUG 21 2015 FORECAST CONCERNS WILL BE THUNDERSTORM CHANCES INTO THE BEGINNING OF THE WEEKEND AND HOW COOL TO MAKE IT SATURDAY NIGHT INTO SUNDAY NIGHT. SATELLITE SHOWING AN AMPLIFIED/BLOCKY OVER THE PACIFIC. THIS TRANSITIONS TO A BROAD TROUGH/WESTERLY ALOFT OVER MOST OF THE COUNTRY. STRONG SYSTEM DIGGING INTO SOUTHWEST CANADA WITH SEVERAL SHORTWAVE TROUGHS EMBEDDED IN THE WESTERLY FLOW. AT JET LEVEL...MODELS DID WELL. AT MID LEVELS...THE GFS/CANADIAN AND THE UKMET WERE DOING A LITTLE BETTER THAN THE ECMWF. THE SREF AND ESPECIALLY THE NAM WERE NOT DOING WELL. THE GFS WAS DOING A LITTLE BETTER THAN THE ECMWF WITH THE LOW LEVEL WIND FIELD. ALL MODELS INITIALIZED WELL ON THE LOW LEVEL THERMAL FIELD DIFFICULT AND UNCERTAIN PRECIPITATION FORECAST...ESPECIALLY THROUGH THIS EVENING. CONFIDENCE IS BELOW AVERAGE FOR THE PRECIPITATION FORECAST. TODAY/TONIGHT...WILL HAVE TO KEEP AN EYE ON ANY LATE NIGHT/EARLY MORNING DEVELOPMENT NEAR THE BOUNDARY JUST TO THE NORTH OF OUR AREA. MODELS HAVE BEEN HINTING AT IT AND WILL CONTINUE TO MONITOR. FOR YESTERDAYS THUNDERSTORMS...JUST ENOUGH MOISTURE ALONG A BOUNDARY WITH A WEAK SHORTWAVE TROUGH WAS ABLE TO SPARK ISOLATED THUNDERSTORMS OVER AND NEAR THE NORTHEAST PORTION OF THE AREA. NOT TOO DIFFERENT A SETUP FOR TODAY FROM YESTERDAY. AGAIN WHAT MAKES FORECAST UNCERTAIN IS THE MOISTURE AVAILABILITY...ESPECIALLY ABOVE THE LOW LEVELS...WHERE DOES THE SURFACE TROUGH SETUP AND THE WEAK/COMPLICATED MID LEVEL FORCING INVOLVED. MODELS HAVE THE BOUNDARY PRETTY CLOSE BUT A LITTLE FURTHER WEST THAN WHAT WAS SHOWN YESTERDAY. 700 MB SHORTWAVE EJECTS INTO THE PLAINS THIS AFTERNOON AND IT LOOKS TO BE IN TWO PIECES. ONE PORTION GOES ACROSS THE NORTH AND IS THE SLOWER OF THE TWO SHORTWAVE TROUGHS. THE SECOND ONE GOES ACROSS TO OUR SOUTH AND BRUSHES THE SOUTHERN PORTION OF THE AREA. THERE IS WEAK FORCING IN BETWEEN. ALSO THE MODELS DIFFER ON HOW FAR EAST DURING THE DAY THEY MOVE THESE SHORTWAVE TROUGHS. CONVECTIVE ALLOWING MODELS ARE HAVING A DIFFICULT WITH ALL THIS. THE ARW HAS LITTLE TO NOTHING. THE HRRR AND ESPECIALLY THE NMM DEVELOP ROBUST CONVECTION OVER THE WESTERN PORTION OF THE AREA THIS AFTERNOON CLOSE TO THE SURFACE TROUGH. THE 00Z NAM DID NOT INDICATE ANYTHING BUT NOW THE 06Z NAM IS MATCHING UP WITH THE ABOVE TWO MODELS. THE 00Z ECMWF EXPLODES CONVECTION OVER THE NORTHERN PORTION OF THE AREA. ALL THIS TIME A RATHER STOUT EML LIES OVER THE AREA. AFTER LOOKING AT THIS AND COLLABORATION...PULLED THE INITIATION A LITTLE FURTHER WEST THAN BEFORE. THE PROBLEM THEN BECOMES HOW FAR EAST TO TAKE THIS ACTIVITY. THE HRRR TAKES IT FURTHER EAST WHILE THE REST OF THE OUTPUT THAT DID DEVELOP SOMETHING JUST KEEPS IT OVER THE WEST AS IT EITHER DISSIPATES THE THUNDERSTORMS OR MOVES THEM OF THE AREA TO THE NORTH OR SOUTH. SO DID LOWER POPS A LITTLE DUE TO THIS. IT DOES LOOK LIKE THE THUNDERSTORMS END BY 06Z. HOWEVER ELEVATED STORMS/REDEVELOPMENT WILL NEED TO BE LOOKED AT AGAIN TO A LOW LEVEL JET AND DECENT WARM AIR ADVECTION PATTERN ALOFT AHEAD OF ANOTHER SHORTWAVE TROUGH. FOR THIS AFTERNOON AND EVENINGS CONVECTION...IF STORMS DEVELOP...IT WILL BE POSSIBLE THAT THESE WILL BECOME SEVERE DUE TO THE INSTABILITY AND LAPSE RATES INVOLVED. NO MATTER IF STORMS DEVELOP OR NOT...BOUNDARY LAYER MOISTURE INCREASES AND AT THE VERY LEAST A LOT OF STRATUS WILL DEVELOP WITH SOME PATCHY FOG INVOLVED. PRESSURE FALLS AND GRADIENT SUPPORT NEAR BREEZY OR BREEZY CONDITIONS. GUIDANCE HAS BEEN RUNNING COOL ON MAXES HERE THE LAST FEW DAYS. THE GFS/MAV HAS BEEN DOING THE BEST AND HAVE RAISED THE MAXES SOME. SATURDAY/SATURDAY NIGHT...PATCHY FOG ENDS BY MID MORNING WITH THE STRATUS LASTING A LITTLE LONGER. THERE ARE STILL DIFFERENCES IN HOW FAST THE MODELS BRING IN THE COLD FRONT. THE NAM IS THE SLOWEST FOLLOWED BY SREF. THE GFS/ECMWF/CANADIAN ARE THE FASTEST. ROUGHLY IT LOOKS LIKE THE FRONT IS THROUGH THE NORTHWEST HALF OF THE AREA BY LATE MORNING. THE FRONT THEN LOOKS TO MOVE ACROSS THE REST OF THE AREA BY LATE AFTERNOON OR EARLY EVENING. THE CHANCE OF THUNDERSTORMS WILL BE OVER THE SOUTHEAST PORTION OF THE AREA IN ADVANCE OF THIS FRONT. CONTINUED THE LOW CHANCE POPS IN THIS AREA. FRONT AND ASSOCIATED FORCING EXIT THE AREA EARLY IN THE EVENING AND SO PRECIPITATION CUTS OFF RATHER FAST. WINDS BEHIND THE FRONT COULD GET WINDY AND THE DAY SHIFT WILL NEED TO LOOK AT RAISING THE WINDS EVEN MORE. DESPITE SIMILAR TIMING TO YESTERDAYS OUTPUT...MODELS HAVE RAISED HIGH TEMPERATURES FOR THE DAY. THE GFS...CANADIAN AND THE NAM ARE IN DECENT AGREEMENT ON THIS. IT SEEMS THAT THE COLDER AIR DOES LAG SLIGHTLY BEHIND THE FRONT. DID RAISE MAXES A LITTLE BUT THEY MAY NEED TO BE RAISED EVEN MORE IN SOUTHERN LOCATIONS. WINDS STAY UP ENOUGH TONIGHT THAT TEMPERATURES SHOULD NOT DROP LIKE A ROCK. IF THE WINDS LET UP QUICKER...GOOD RADIATIONAL CONDITIONS WOULD BE IN PLACE AND A LOWERING OF THE MINS WOULD BE NEEDED. SUNDAY/SUNDAY NIGHT...DRY PERIOD WITH POST FRONTAL COOL AIR MASS IN PLACE. NEW GUIDANCE FOR TEMPERATURES VERY SIMILAR TO WHAT WAS IN THERE FOR MAXES AND MADE ONLY SLIGHT ADJUSTMENTS. ONCE AGAIN FOR THE MINS...IF WINDS END UP BEING LESS THAN CURRENTLY PREDICTED ADDITIONAL COOLING WILL BE NEEDED. .LONG TERM...(MONDAY THROUGH THURSDAY) ISSUED AT 330 AM MDT FRI AUG 21 2015 THE EXTENDED PERIOD LOOKS TO BE MOSTLY DRY ALONG WITH NEAR TO ABOVE NORMAL TEMPERATURES FOR THE AREA AS RIDGING INFLUENCES THE FORECAST. ON MONDAY...AN UPPER LEVEL RIDGE CONTINUES TO BUILD INTO THE PLAINS FOLLOWING THE SYSTEM PREDICTED TO IMPACT THE REGION THIS WEEKEND. THE RIDGE AMPLIFIES AND MOVES EAST EARLY NEXT WEEK...WITH ITS AXIS NEARING THE PLAINS ON WEDNESDAY. DRY CONDITIONS ARE EXPECTED DURING THIS TIME FRAME. MOISTURE RETURNS TO THE AREA WEDNESDAY AND THURSDAY AS A SHORTWAVE MOVES ALONG THE PERSISTENT RIDGE. THIS DISTURBANCE LOOKS TO GENERATE SHOWER AND THUNDERSTORM CHANCES WEDNESDAY NIGHT AND THURSDAY FOR PORTIONS OF THE REGION. AFTER SUNDAYS COOL DOWN...TEMPERATURES ARE EXPECTED TO QUICKLY REBOUND IN THE EXTENDED PERIOD WITH HIGHS IN THE UPPER 80S TO LOW 90S AND LOWS IN THE UPPER 50S TO UPPER 60S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 540 AM MDT FRI AUG 21 2015 AT THIS TIME VFR CONDITIONS ARE EXPECTED AT BOTH SITES. SOUTHERLY WINDS WILL INCREASE THIS MORNING AND BECOME GUSTY. THESE GUSTY WINDS WILL LAST WELL INTO THE NIGHT WITH SUSTAINED SPEEDS OF 14 TO 17 KNOTS WITH GUSTS 22 TO 25 KNOTS. THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND EVENING BUT MODEL DIFFERENCES ON TIME AND AREA OF INITIATION MAKE THINGS A LITTLE UNCERTAIN. AT THIS TIME ONLY FEEL COMFORTABLE ENOUGH TO PUT IN A VCTS AT BOTH SITES WITH KGLD STARTING AT 21Z AND KMCK AT 00Z. THUNDERSTORMS ARE EXPECTED TO BE DONE BY 03Z. LATER IN THE NIGHT SOME FOG IS EXPECTED VISIBILITIES STAYING ABOVE MVFR. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JTL SHORT TERM...BULLER LONG TERM...JBH AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1238 PM CDT FRI AUG 21 2015 .DISCUSSION... FOR THE 21/18Z TAF ISSUANCE. && .AVIATION... NUMEROUS SHOWERS AND THUNDERSTORMS WILL CONTINUE TO SPREAD NORTH DURING THE AFTERNOON HOURS. MAIN ACTIVITY HAS MOVED NORTH OF KBPT...SO WILL JUST MENTION VCSH THERE. WILL HAVE PREVAILING SHOWERS WITH VCTS FOR KLCH/KLFT/KARA THROUGH MID AFTERNOON 21/20Z...WITH ACTIVITY BEGINNING AT KAEX AROUND 21/19Z. UPPER LEVEL DISTURBANCE WILL MOVE OFF TO THE NORTH LATE THIS AFTERNOON...AND WITH LOSS OF DAYTIME HEATING...MOST OF THE ACTIVITY WILL DISSIPATE BY 22/01Z...WITH VFR CONDITIONS THEN EXPECTED FOR THE NIGHT...WITH EXCEPTION OF KAEX...WHERE SOME MVFR PATCHY FOG MAY OCCUR NEAR DAYBREAK. RUA && .PREV DISCUSSION... /ISSUED 954 AM CDT FRI AUG 21 2015/ DISCUSSION... NUM SHRA/TSRA BEGINNING TO MOVE ASHORE SE TX/SW LA IN ASSOCIATION WITH THE NEXT UPPER LEVEL IMPULSE MOVING NE ACROSS THE TX COAST THIS MORNING. THUS...HAD TO BUMP UP POPS AND QPF SIGNIFICANTLY THIS MORNING...CLOSE TO HRRR GUIDANCE WHICH HAS A GOOD HANDLE ON THIS SITUATION. ALSO INCLUDED HEAVY RAINFALL POSSIBLE AS THESE WILL BE SOMEWHAT SLOWER MOVING. WITH THE INCREASED CLOUD COVER...AGREE WITH HRRR AND LOWERED TEMPS ACROSS SE TX/SW LA. OTHERWISE...BUMPED UP WINDS A BIT TO 10-15 KTS ACROSS THE COASTAL WATERS THIS MORNING AS THIS SYSTEM MOVES ACROSS THE REGION. THATS ABOUT IT. UPDATES ALREADY OUT. DML PREV DISCUSSION... /ISSUED 716 AM CDT FRI AUG 21 2015/ DISCUSSION... FOR THE 12Z TAF PACKAGE. AVIATION... QUIETER NIGHT AND MORNING VERSUS THE PREVIOUS COUPLE OF DAYS...THOUGH CONVECTIVE ACTIVITY HAS BEEN ON THE INCREASE OVER THE COASTAL WATERS FOR THE PAST COUPLE OF HRS...ESPECIALLY OFF THE SE TX/SW LA COASTS. LATEST HIGH RESOLUTION MODEL DATA DEPICTS THE WELL DEFINED SHORTWAVE OVER THE MIDDLE TX COAST...AND ITS ASSOCIATED CONVECTION...LIFTING NE THROUGH THE AREA LATER THIS MORNING INTO THE AFTERNOON. VCTS WAS INSERTED AT EACH SITE BASED ON THIS THINKING. RECENT PLUNGE IN VSBY AT KAEX IS EXPECTED TO BE SHORT LIVED...PERHAPS AN HR OR SO. WILL CONTINUE TO MONITOR FOR A POSSIBLE AMD. VFR EXPECTED TO PREVAIL OUTSIDE OF CONVECTION...AND BY THIS EVENING AS ACTIVITY LIFTS NE OF THE AREA. 13 PREV DISCUSSION... /ISSUED 452 AM CDT FRI AUG 21 2015/ SYNOPSIS... A NEARLY STATIONARY W-E ORIENTED SFC FRONT EXTENDS FM NE TX ACRS NRN LA INTO CNTL MS. THE FRONT HAS BECOME A LITTLE MORE DIFFUSE THE PAST SEVERAL HOURS...AS DEWPOINTS ALONG AND SOUTH OF THE FRONTAL ZONE ARE IN THE LOWER TO MIDDLE 70S WITH COOLER AND DRIER AIR LOCATED WELL BEHIND THE BOUNDARY ACRS NRN/CNTL ARK AND FAR N MS. THE LATEST WV IMAGERY AND UA ANALYSIS SHOWS MOISTURE ALOFT BEING FUNNELED OVER THE REGION ON SWLY FLOW BETWEEN A TROF/WEAKNESS OVER THE SRN PLAINS AND AN UPR RIDGE ACRS THE GULF OF MEXICO. A LITTLE LESS CONVECTIVE ACTIVITY SO FAR TODAY THAN THE PAST COUPLE OF MORNINGS...ALTHOUGH REGIONAL RADAR MOSAIC SHOWS SCT SHOWERS AND A FEW TSTMS DEVELOPING OFF THE UPR TX COAST AND OVER GALVESTON BAY WITH MORE ISOLATED ACTIVITY OVER OUR COASTAL WATERS ZONES. FURTHER INLAND...A BAND OF LT TO MDT RAIN WAS LOCATED NEAR THE FRONTAL BOUNDARY...FM JUST NORTH OF THE LAKES REGION OF SE TX INTO PORTIONS OF WRN LA. DISCUSSION... THE FRONT WILL GRADUALLY WEAKEN AS IT LIFTS BACK NORTH LATER TODAY. HOWEVER...ABUNDANT MOISTURE REMAINS OVER THE AREA AND WITH THE LINGERING DISTURBANCE OR WEAKNESS ALOFT...EXPECT SCT CONVECTION TO AGAIN DEVELOP TODAY. THIS ACTIVITY IS EXPECTED TO BE MORE DIURNALLY DRIVEN...WITH THE SEABREEZE BOUNDARY AND THE DISSIPATING FRONT FOCUSING CONVECTIVE DEVELOPMENT AS DAYTIME HEATING GETS UNDERWAY. PRECIP WATER VALUES WILL REMAIN NEAR 2 INCHES...AND THIS SHOULD AGAIN ALLOW TSTMS TO BE EFFICIENT RAINFALL PRODUCERS WITH HIGH RAIN RATES AT TIMES. CLOUDY SKIES ON THURSDAY HELPED TO KEEP TEMPERATURES IN THE 80S...WITH SOME LOCATIONS ONLY REACHING THE LOWER 80S. WHILE THIS MAY BE THE CASE AGAIN TODAY...THINK CLOUD AND CONVECTIVE COVERAGE WILL BE A LITTLE LESS AND OCCASIONAL PEEKS OF SUN SHOULD ALLOW TEMPERATURES TO RISE TO NEAR 90 IN THE AFTN. MEANWHILE...THE WEAKNESS ALOFT WILL MORE OR LESS LINGER OVER THE REGION THROUGH THE WEEKEND EVEN AS THE HIGH OVER THE ERN GULF BEGINS TO BUILD WEST. THERE WILL STILL BE A DAILY CHC FOR SHOWERS OR STORMS SATURDAY AND SUNDAY BUT COVERAGE WILL BE LOWER AS SLIGHTLY DRIER AIR BEGINS TO WORK INTO THE REGION. WITH LESS CONVECTION AND CLOUDS...AFTN TEMPERATURES WILL BEGIN A WARMING TREND. BY EARLY NEXT WEEK...THE HIGH WILL RETROGRADE FURTHER WEST AS A SHORTWAVE TROF DIGS OVER THE ERN STATES...WITH THE SYSTEM GRADUALLY AMPLIFYING OVER THE CONUS. THIS WILL LEAD TO A DEEPENING NLY FLOW THAT WILL PUSH A SFC FRONT INTO THE AREA BY TUESDAY. RAIN CHCS WILL BUMP BACK UP IN ADVANCE OF THE FRONT MONDAY INTO TUESDAY. GLOBAL MODELS ARE IN GENERAL AGREEMENT REGARDING THE DEVELOPMENT OF THIS AMPLIFIED SYSTEM AND ASSOCIATED SFC FROPA...AND KEEPING THE AREA UNDER A NLY FLOW ALOFT THROUGH THE LATTER PART OF THE WEEK. SHOULD THIS SCENARIO PAN OUT...DRIER MORE COMFORTABLE CONDITIONS CAN BE EXPECTED FROM WEDNESDAY THROUGH FRIDAY WITH SLIGHTLY BELOW NORMAL LOWS IN THE UPPER 60S TO LOWER 70S AND HIGHS NEAR NORMAL IN THE LOWER 90S. 24 MARINE... A LT TO OCCASIONALLY MDT ONSHORE FLOW AND LOW SEAS WILL PERSIST THROUGH EARLY NEXT WEEK AS HIGH PRES CONTINUES TO RIDGE OVER THE GULF. A LINGERING DISTURBANCE OVER THE REGION WILL ALLOW FOR SCT SHOWERS AND TSTMS TODAY...BUT RAIN CHCS WILL DECREASE OVER THE WEEKEND AS HIGH PRES BUILDS ALOFT. A FRONT WILL MOVE SOUTH INTO THE AREA BY LATE MONDAY INTO TUESDAY...BRINGING ANOTHER CHC FOR SHOWERS OR TSTMS. AT THIS TIME...MODEL GUIDANCE SHOWS THIS FRONT MOVING SOUTH OVER THE COASTAL WATERS ZONES...WITH OFFSHORE FLOW AND DRIER WEATHER POSSIBLE FOR THE MIDDLE AND LATTER PART OF NEXT WEEK. 24 && .PRELIMINARY POINT TEMPS/POPS... AEX 92 74 94 75 / 70 20 30 10 LCH 85 77 90 77 / 60 20 30 10 LFT 87 76 91 76 / 70 20 30 10 BPT 84 77 90 77 / 80 20 30 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$ AVIATION...07
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
402 PM EDT FRI AUG 21 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 316 PM EDT FRI AUG 21 2015 WEATHER REMAINS QUIET INTO SATURDAY WITH WARMING TREND. IN THE REAL NEAR TERM...TRYING TO FIGURE OUT IF THE HRRR AND RAP SHOWING A FEW BLIPS ON THE MODELED REFLECTIVITY ARE REALISTIC. REGIONAL RADAR LOOP HAS SHOWN ISOLD ECHOES OVER NORTHERN WI...BUT ONLY OBS SHOWING LGT RAIN ARE OVER WCNTRL WI CLOSER TO MUCAPES OF A FEW HUNDRED J/KG. ANOTHER AGITATED AREA OF MID CLOUDS AND ISOLD SHRA IS OVER MN ARROWHEAD. MAIN SHORTWAVE DRIVING THAT AREA OF WX IS LIFTING OVER NORTHERN ONTARIO INSTEAD OF TOWARD UPR MICHIGAN. OVER THE CWA REST OF THIS AFTN...HRRR AND RAP SOUNDINGS SHOW NARROW LAYER OF MOISTURE AROUND H7 WITH DRY AIR BLO AND ABOVE. GOING TO KEEP IT DRY WITH JUST INCREASING MID CLOUDS LATE THIS AFTN INTO THE EVENING. FOR REST OF SHORT TERM...STRONG UPPER LEVEL TROUGH OVER SOUTHERN BRITISH COLUMBIA THIS AFTN DIGS ACROSS ROCKIES OF ALBERTA AND MONTANA TONIGHT INTO SATURDAY MORNING WITH SFC TROUGH OVER MONTANA THIS AFTN DEEPENING TO A 995-1000MB SFC LOW OVER DAKOTAS BY 12Z SATURDAY. SINCE SFC LOW AND COLD FRONT REMAIN TO THE WEST OF UPR MICHIGAN THROUGH EARLY SATURDAY EVENING...APPEARS TO BE A DRY...WARM...AND WINDY DAY IN THE WARM SECTOR OF THE SFC LOW. WINDS HAVE POTENTIAL TO BE QUITE GUSTY WITH EASILY 25-30 KTS IN THE MIXED LAYER ON SATURDAY AFTN. IN ADDITION...PRESSURE GRADIENT WILL BE TIGHT AS UPR MICHIGAN IS BETWEEN THE APPROACHING SFC LOW AND DEPARTING HIGH OVER THE LOWER GREAT LAKES. DECENT AGREEMENT FM NAM/GFS/GEM-REGIONAL ON THE WINDS/WIND GUSTS FOR SATURDAY. COULD SEE WIND GUSTS 30 TO POSSIBLY 40 MPH DURING PEAK HEATING ON SATURDAY AFTN. THERE IS A CAVEAT FOR THE MIXING STRENGTH THOUGH. NOT A LOT OF CLOUD COVER EXPECTED AS MOST MID CLOUDS THAT MOVE THROUGH INTO EARLY THIS EVENING WILL BE NORTH AND EAST OF THE AREA ON SATURDY. YET...LIKELY WILL SEE FILTERED OR DIMMED SUNSHINE AS WIDESPREAD AREA OF SMOKE ALOFT OVER THE ROCKIES AND PLAINS TODAY /25KFT AGL PER MANUAL SFC OBS FM DAKOTAS TO MINNESOTA/ MOVES OVER THE UPPER GREAT LAKES BASED ON EXPECTED WINDS IN THE SMOKE LAYER /H4-H3/. ALWAYS TOUGH TO PREDICT EXACT COVERAGE AND THICKNESS OF SMOKE LAYER...BUT GIVEN ALL THE SMOKE UPSTREAM THIS AFTN...TRENDED HIGHER ON THE SKY COVER TO AT LEAST GO PARTLY CLOUDY INSTEAD OF SUNNY. DURING OTHER BOUTS EARLIER THIS SUMMER WITH SMOKE ALOFT...MIXING WAS HELD DOWN MORE THAN WHAT YOU WOULD NORMALLY EXPECT...SO THAT MAY OCCUR AGAIN. BASED ON FORECAST H85 TEMPS OF 16-18C...TEMPS SHOULD REACH THE 80S AWAY FM LAKE MICHIGAN. CAPPED READINGS IN THE LOW TO MID 80S...WARMEST ALONG LK SUPERIOR DUE TO STRONG/GUSTY SOUTH WINDS PROVIDING DOWNSLOPING WARMING. TEMPS NEAR LK MICHIGAN WILL REACH UPPER 70S. WILL BE BUMPY AGAIN FOR WINDS/WAVES ON NORTHERN LK MICHIGAN ESPECIALLY ON SATURDAY AFTN DUE TO THE INCREASING SOUTH WINDS. PROBABLY WILL NEED ANOTHER SMALL CRAFT ADVISORY FOR THE MARINE INTERESTS. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 401 PM EDT FRI AUG 21 2015 THE END OF THE WEEKEND WILL BE FAIRLY ACTIVE WEATHER WISE...WITH ANOTHER AUTUMN LIKE COLD FRONT MOVING THROUGH THE AREA ON SUNDAY. THE MODELS ARE IN GOOD AGREEMENT ON TIMING OF THE FRONTAL PASSAGE ACROSS THE AREA BEING SUNDAY MORNING...WITH MUCH COOLER AIR MOVING ACROSS THE AREA LATER SUNDAY NIGHT INTO MONDAY AS THE UPPER LOW SETTLES JUST NORTH OF LAKE SUPERIOR. AS SUCH...WILL KEEP LIKELY POPS SPREADING WEST TO EAST LATER SATURDAY NIGHT INTO SUNDAY MORNING. DUE TO THE TIMING OF THE FRONTAL PASSAGE DURING THE NIGHT AND EARLY MORNING HOURS...DO NOT EXPECT WIDESPREAD THUNDERSTORM ACTIVITY. HOWEVER...CANNOT RULE OUT STORMS DEVELOPING OVER MN EARLY SAT EVENING WITH THE RESIDUAL MOVING INTO UPPER MI OVERNIGHT. AS SUCH...WILL KEEP THUNDER CHANCES IN THE FORECAST AHEAD OF THE FRONT. AFTER FROPA...EXPECT SCATTERED RAIN SHOWERS IN THE CYCLONIC FLOW...ALTHOUGH THERE WILL LIKELY BE A LULL IN THE PCPN IMMEDIATELY BEHIND THE COLD FRONT SUNDAY IN THE DRY SLOT. BEST CHANCES FOR SHOWER ACTIVITY WILL BE LATER SUNDAY NIGHT INTO MONDAY DOWNWIND OF LAKE SUPERIOR WHERE SOME LAKE EFFECT RAIN IS POSSIBLE DUE TO 850MB TEMPS DROPPING TO +4C YIELDING LAKE INDUCED INSTABILITY WITH WATER TEMPS AROUND +15C ESPECIALLY ACROSS THE WESTERN BASIN. AS SUCH...WILL MAINTAIN NUMEROUS RAIN SHOWERS FOR SUNDAY NIGHT AND MONDAY FOR NORTHWEST UPPER MICHIGAN AND SCATTERED SHOWERS ELSEWHERE. TEMPERATURES ON SUNDAY WILL LIKELY DROP DURING THE DAY WHILE TEMPS ON MONDAY WILL BE LUCKY TO RISE OUT OF THE 50S. IN FACT...WITH 850MB TEMPS BEING SO COLD...IF IT REMAINS CLOUDY ALL DAY THERE MAY BE SPOT OR TWO THAT STAYS IN THE UPPER 40S/LOWER 50S ON MONDAY. REGARDLESS...MONDAY WILL FEEL QUITE LIKE AUTUMN WITH BREEZY CONDITIONS AND COOL TEMPERATURES. WITH THE UPPER LOW BECOME CLOSED OFF NORTH OF THE AREA...WE WILL SEE PERSISTING DEEP CYCLONIC NW FLOW THROUGH TUESDAY WITH DEEP MOISTURE REMAINING ACROSS THE AREA. WILL NEED TO MAINTAIN SCATTERED SHOWERS MONDAY NIGHT CLOSER TO LAKE SUPERIOR...THEN SLOWLY TAPERING FROM WEST TO EAST DURING THE DAY ON TUESDAY AS THE UPPER LOW IS FORECAST TO MOVE EAST YIELDING TO CONFLUENT NW FLOW ALOFT. QUIET BUT STILL COOL WEATHER EXPECTED ON WEDNESDAY WITH HIGH PRESSURE IN CONTROL AND UPPER HEIGHTS RISE. NEXT CHANCE FOR PRECIPITATION WILL BE LATE THURSDAY INTO FRIDAY MORNING WITH THE NEXT SYSTEM MOVING THROUGH THE NW FLOW ALOFT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 215 PM EDT FRI AUG 21 2015 VFR CONDITIONS WILL PERSIST THROUGH THE TAF PERIOD. SCATTERED MID CLOUDS THIS AFTN AND A THICK SMOKE LAYER ALOFT TONIGHT INTO SATURDAY. GUSTY SOUTH WINDS AT KIWD REST OF THE AFTN WILL GIVE WAY TO LOW-LEVEL WIND SHEAR BY MIDNIGHT TONIGHT AS WINDS DIMINISH AT THE SFC. WINDS WILL ALSO BECOME GUSTY FOR A TIME AT KSAW THIS AFTN AS WELL. EXPECT STRONG AND GUSTY SOUTH WINDS AT ALL TAF SITES ON SATURDAY ONCE LOW-LEVEL INVERSION BREAKS BY MID MORNING. WIND GUSTS SATURDAY AFTN COULD TOP OUT NEAR 30 KTS AT KIWD AND KSAW. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 316 PM EDT FRI AUG 21 2015 S WINDS INCREASE TO 25 KTS TONIGHT UNDER SHARPENING PRES GRADIENT BETWEEN THE DEPARTING RIDGE AND A DEEP LOW PRESSURE SYSTEM MOVING FROM THE NORTHERN PLAINS INTO ONTARIO. MAY SEE GUSTS TO 30 KTS OVER EASTERN LK SUPERIOR ON SATURDAY AFTN. STEADY S WINDS WILL VEER TOWARD THE W FOLLOWING A COLD FRONTAL PASSAGE ON LATE SAT NIGHT/SUN AND INCREASE UP TO 30 KTS. DEPENDING ON THE INTENSITY OF A LOW PRESSURE SYSTEM MOVING SLOWLY NE THRU ONTARIO...THERE COULD BE SOME MARGINAL GALES TO 35 KTS AT TIMES ON SUN INTO MON WITH THE ARRIVAL OF COOLER AIR/MORE DESTABILIZATION OVER THE RELATIVELY WARM LAKE WATERS AS THE FLOW CONTINUES TO VEER TO THE NW UNDER TIGHT PRES GRADIENT AHEAD OF APPROACHING HI PRES RIDGE FROM THE NORTHERN PLAINS. AS THE HI MOVES CLOSER AND THE GRADIENT SLACKENS...EXPECT WINDS TO DIMINISH LATER TUE INTO WED. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLA LONG TERM...MRD AVIATION...JLA MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
317 PM EDT FRI AUG 21 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 316 PM EDT FRI AUG 21 2015 WEATHER REMAINS QUIET INTO SATURDAY WITH WARMING TREND. IN THE REAL NEAR TERM...TRYING TO FIGURE OUT IF THE HRRR AND RAP SHOWING A FEW BLIPS ON THE MODELED REFLECTIVITY ARE REALISTIC. REGIONAL RADAR LOOP HAS SHOWN ISOLD ECHOES OVER NORTHERN WI...BUT ONLY OBS SHOWING LGT RAIN ARE OVER WCNTRL WI CLOSER TO MUCAPES OF A FEW HUNDRED J/KG. ANOTHER AGITATED AREA OF MID CLOUDS AND ISOLD SHRA IS OVER MN ARROWHEAD. MAIN SHORTWAVE DRIVING THAT AREA OF WX IS LIFTING OVER NORTHERN ONTARIO INSTEAD OF TOWARD UPR MICHIGAN. OVER THE CWA REST OF THIS AFTN...HRRR AND RAP SOUNDINGS SHOW NARROW LAYER OF MOISTURE AROUND H7 WITH DRY AIR BLO AND ABOVE. GOING TO KEEP IT DRY WITH JUST INCREASING MID CLOUDS LATE THIS AFTN INTO THE EVENING. FOR REST OF SHORT TERM...STRONG UPPER LEVEL TROUGH OVER SOUTHERN BRITISH COLUMBIA THIS AFTN DIGS ACROSS ROCKIES OF ALBERTA AND MONTANA TONIGHT INTO SATURDAY MORNING WITH SFC TROUGH OVER MONTANA THIS AFTN DEEPENING TO A 995-1000MB SFC LOW OVER DAKOTAS BY 12Z SATURDAY. SINCE SFC LOW AND COLD FRONT REMAIN TO THE WEST OF UPR MICHIGAN THROUGH EARLY SATURDAY EVENING...APPEARS TO BE A DRY...WARM...AND WINDY DAY IN THE WARM SECTOR OF THE SFC LOW. WINDS HAVE POTENTIAL TO BE QUITE GUSTY WITH EASILY 25-30 KTS IN THE MIXED LAYER ON SATURDAY AFTN. IN ADDITION...PRESSURE GRADIENT WILL BE TIGHT AS UPR MICHIGAN IS BETWEEN THE APPROACHING SFC LOW AND DEPARTING HIGH OVER THE LOWER GREAT LAKES. DECENT AGREEMENT FM NAM/GFS/GEM-REGIONAL ON THE WINDS/WIND GUSTS FOR SATURDAY. COULD SEE WIND GUSTS 30 TO POSSIBLY 40 MPH DURING PEAK HEATING ON SATURDAY AFTN. THERE IS A CAVEAT FOR THE MIXING STRENGTH THOUGH. NOT A LOT OF CLOUD COVER EXPECTED AS MOST MID CLOUDS THAT MOVE THROUGH INTO EARLY THIS EVENING WILL BE NORTH AND EAST OF THE AREA ON SATURDY. YET...LIKELY WILL SEE FILTERED OR DIMMED SUNSHINE AS WIDESPREAD AREA OF SMOKE ALOFT OVER THE ROCKIES AND PLAINS TODAY /25KFT AGL PER MANUAL SFC OBS FM DAKOTAS TO MINNESOTA/ MOVES OVER THE UPPER GREAT LAKES BASED ON EXPECTED WINDS IN THE SMOKE LAYER /H4-H3/. ALWAYS TOUGH TO PREDICT EXACT COVERAGE AND THICKNESS OF SMOKE LAYER...BUT GIVEN ALL THE SMOKE UPSTREAM THIS AFTN...TRENDED HIGHER ON THE SKY COVER TO AT LEAST GO PARTLY CLOUDY INSTEAD OF SUNNY. DURING OTHER BOUTS EARLIER THIS SUMMER WITH SMOKE ALOFT...MIXING WAS HELD DOWN MORE THAN WHAT YOU WOULD NORMALLY EXPECT...SO THAT MAY OCCUR AGAIN. BASED ON FORECAST H85 TEMPS OF 16-18C...TEMPS SHOULD REACH THE 80S AWAY FM LAKE MICHIGAN. CAPPED READINGS IN THE LOW TO MID 80S...WARMEST ALONG LK SUPERIOR DUE TO STRONG/GUSTY SOUTH WINDS PROVIDING DOWNSLOPING WARMING. TEMPS NEAR LK MICHIGAN WILL REACH UPPER 70S. WILL BE BUMPY AGAIN FOR WINDS/WAVES ON NORTHERN LK MICHIGAN ESPECIALLY ON SATURDAY AFTN DUE TO THE INCREASING SOUTH WINDS. PROBABLY WILL NEED ANOTHER SMALL CRAFT ADVISORY FOR THE MARINE INTERESTS. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 407 AM EDT FRI AUG 21 2015 ALTHOUGH THE WEEKEND WL START ON A DRY AND WARMER NOTE...ANOTHER POTENT SHRTWV DRIFTING E THRU THE NRN PLAINS TOWARD THE UPR LKS WL BRING AN UNSETTLED PERIOD OF WX TO THE CWA LATE SAT NGT INTO EARLY NEXT WEEK. TIMING/IMPACTS OF THIS DISTURBANCE ARE THE PRIMARY FOCUS FOR THIS SHIFT. RIGHT NOW...THE ACCOMPANYING DYNAMIC FORCING LOOKS SUFFICIENT TO JUSTIFY A PERIOD OF SOME HI LIKELY POPS AHEAD OF ATTENDANT COLD FROPA FOR LATE SAT NGT THRU SUN DESPITE CONCERNS ON MSTR INFLOW THAT WL LIMIT TS CHCS. SAT...UPR MI WL REMAIN DOMINATED BY LARGE SCALE SUBSIDENCE/DRY AIRMASS ASSOCIATED WITH SLOWLY EXITING UPR RDG TO THE E OF POTENT SHRTWV MOVING INTO THE NRN PLAINS. GUSTY S FLOW BTWN SFC HI PRES DRIFTING INTO THE MID ATLANTIC STATES AND LO PRES NEAR THE CNDN BORDER/ATTENDANT COLD FNT MOVING INTO MN LATER IN THE DAY IS FCST TO LIFT H85 TEMPS TO 16-18C...SUPPORTING HI TEMPS WELL INTO THE 80S AWAY FM THE COOLING INFLUENCE OF LK MI WITH A GOOD DEAL OF SUNSHINE. SAT NGT...ARRIVAL OF WARM CONVEYOR BELT MSTR RIBBON/SFC COLD FNT OVER THE W HALF LATE SAT NGT AHEAD OF SHRTWV MOVING INTO MN WL BRING A RETURN OF SHOWERS/SOME TS TO THAT AREA. DESPITE THE STRENGTH OF THE INCOMING SHRTWV/SLY FLOW AHEAD OF THE FNT...OVERALL MSTR INFLOW INTO UPR MI IS FCST TO BE SOMEWHAT LIMITED AND FOCUSED TO THE S IN WI SO THAT ONLY A NARROW BAND OF PWAT ARND 1.50 INCHES IS SHOWN TO MOVE INTO THE W OVERNGT. ARRIVAL OF THE FNT DURING PERIOD OF NOCTURNAL COOLING WL ALSO BE A LIMITING FACTOR...WITH FCST MUCAPE NO HIER THAN ABOUT 500-600 J/KG. BUT WITH 12HR H5 HGT FALLS UP TO 100M AHEAD OF THE APRCHG SHRTWV THAT IS FCST TO BECOME CUTOFF AT H5...DID RETAIN LIKELY POPS UNDER THE WARM CONVEYOR BELT. THE E HALF SHOULD REMAIN DRY CLOSER TO DEPARTING SFC HI PRES TO THE E. SUN...STRONG SHRTWV IS FCST TO DRIFT ONLY SLOWLY E THRU NRN MN... PUSHING COLD FNT/WARM CONVEYOR BELT MSTR RIBBON TO NEAR NEWBERRY LATE IN THE DAY. BAND OF SHOWERS WITH EMBEDDED TS IN PRESENCE OF SOME DAYTIME HEATING WL DRIFT ACRS UPR MI ALONG THIS FNT UNDER AREA OF SUPPORTING DEEP LYR QVECTOR CNVGC THAT MAY BE ENHANCED BY ANOTHER DISTURBANCE ROTATING ARND THE SLOW MOVING CUTOFF H5 LO. ARRIVAL OF SOME DEEP LYR QVECTOR DVGC/DRY SLOTTING WL DIMINISH THE SHOWER CHCS W-E BEHIND THE FROPA...BUT AREA OF WRAP ARND LO-MID LVL MSTR IN CONCERT WITH DAYTIME HEATING/UPSLOPE LLVL CYC W FLOW ARND LO PRES IN ONTARIO MAY RESULT IN SOME MORE SHOWERS OVER THE W HALF IN THE AFTN. H85 TEMPS ARE FCST TO FALL TO 6-8C OVER THE W HALF IN THE AFTN...SO TEMPS MAY ACTUALLY FALL IN THAT AREA. THE 00Z NAM MODEL IS QUITE A BIT SLOWER ON THE FROPA TIMING THAN THE OTHER MODELS AND WAS NOT UTILIZED PER NCEP PREFERENCE. SUN NGT THRU TUE...UPR MI IS FCST TO BE DOMINATED BY DEEP... STRONG CYC NW FLOW OF COOL AIR ANRD STACKED CLOSED LO EXITING ONLY SLOWLY TO THE ENE THRU ONTARIO. H85 TEMPS WL BE WITHIN A FEW DEGREES OF 5C...RESUTLING IN SOME COOL WX THAT WL BE MORE TYPICAL OF EARLY FALL. GUSTY WINDS WITH H925 WINDS UP TO 30-35 KTS WL MAKE THE AIR FEEL EVEN COOLER. COMBINATION OF THE SHARP CYC FLOW...POTENTIAL EMBEDDED SHRTWVS ROTATING ARND THE CLOSED LO AND COOLNESS OF THE AIRMASS OVER THE RELATIVELY WARM LK WATERS /WATER TEMPS OVER THE OPEN WATERS OF WRN LK SUP ARE 15-17C/ WL RESULT IN NMRS SHOWERS... ESPECIALLY OVER THE HIER TERRAIN OF THE NW HALF. GOING LIKELY POPS IN THIS AREA SEEM ON TRACK. DAYTIME HEATING ON MON WL LIKELY RESULT IN SCT SHOWERS EVEN AWAY FM THAT AREA. AS UPR HGTS GRDLY RISE ON TUE AND THE LLVL CYC FLOW BEGINS TO WEAKEN ON TUE WITH THE CLOSER APRCH OF TRAILING HI PRES...POPS/CLDS/GUSTY WINDS WL DIMINISH. EXTENDED...TRAILING HI PRES WL BRING A DRY...SEASONABLE PERIOD ON TUE NGT THRU WED NGT UNDER RISING HGTS TO THE E OF BLDG UPR RDG IN THE PLAINS. DEPENDING ON HOW QUICKLY ANOTHER SHRTWV RIDES OVER THIS RDG...SHOWER/TS CHCS MAY RETURN AS EARLY AS NEXT THU ALONG WITH SOME WARMER WX. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 215 PM EDT FRI AUG 21 2015 VFR CONDITIONS WILL PERSIST THROUGH THE TAF PERIOD. SCATTERED MID CLOUDS THIS AFTN AND A THICK SMOKE LAYER ALOFT TONIGHT INTO SATURDAY. GUSTY SOUTH WINDS AT KIWD REST OF THE AFTN WILL GIVE WAY TO LOW-LEVEL WIND SHEAR BY MIDNIGHT TONIGHT AS WINDS DIMINISH AT THE SFC. WINDS WILL ALSO BECOME GUSTY FOR A TIME AT KSAW THIS AFTN AS WELL. EXPECT STRONG AND GUSTY SOUTH WINDS AT ALL TAF SITES ON SATURDAY ONCE LOW-LEVEL INVERSION BREAKS BY MID MORNING. WIND GUSTS SATURDAY AFTN COULD TOP OUT NEAR 30 KTS AT KIWD AND KSAW. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 316 PM EDT FRI AUG 21 2015 S WINDS INCREASE TO 25 KTS TONIGHT UNDER SHARPENING PRES GRADIENT BETWEEN THE DEPARTING RIDGE AND A DEEP LOW PRESSURE SYSTEM MOVING FROM THE NORTHERN PLAINS INTO ONTARIO. MAY SEE GUSTS TO 30 KTS OVER EASTERN LK SUPERIOR ON SATURDAY AFTN. STEADY S WINDS WILL VEER TOWARD THE W FOLLOWING A COLD FRONTAL PASSAGE ON LATE SAT NIGHT/SUN AND INCREASE UP TO 30 KTS. DEPENDING ON THE INTENSITY OF A LOW PRESSURE SYSTEM MOVING SLOWLY NE THRU ONTARIO...THERE COULD BE SOME MARGINAL GALES TO 35 KTS AT TIMES ON SUN INTO MON WITH THE ARRIVAL OF COOLER AIR/MORE DESTABILIZATION OVER THE RELATIVELY WARM LAKE WATERS AS THE FLOW CONTINUES TO VEER TO THE NW UNDER TIGHT PRES GRADIENT AHEAD OF APPROACHING HI PRES RIDGE FROM THE NORTHERN PLAINS. AS THE HI MOVES CLOSER AND THE GRADIENT SLACKENS...EXPECT WINDS TO DIMINISH LATER TUE INTO WED. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLA LONG TERM...KC AVIATION...JLA MARINE...JLA
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1001 AM PDT FRI AUG 21 2015 .SYNOPSIS...HAZY CONDITIONS WILL CONTINUE OVER THE NEXT FEW DAYS DUE TO SMOKE PASSING THROUGH THE AREA FROM CALIFORNIA WILDFIRES. A WEAK PUSH OF MOISTURE WILL LEAD TO SLIGHT CHANCES FOR THUNDERSTORMS OVER MAINLY THE HIGHER TERRAIN SOUTH OF INTERSTATE 15 FRIDAY AND SATURDAY. DEEPER MOISTURE ARRIVES MONDAY AND COULD LINGER THROUGH MID WEEK WHICH WILL RESULT IN INCREASING COVERAGE OF SHOWERS AND STORMS. && .UPDATE...EXTENSIVE AREA OF SMOKE/HAZE VISIBLE OFF SATELLITE COVERING MUCH OF INYO COUNTY AND SOUTHERN NEVADA. VISIBILITY SHOULD IMPROVE THROUGHOUT THE DAY DUE TO A DEEPER MIXED LAYER. BASED ON THE HRRR AND 12Z NAM/GFS REMOVED MENTION OF THUNDERSTORMS FROM THE HIGHER TERRAIN OF SOUTHERN NEVADA AND MUCH OF MOHAVE COUNTY TODAY. LEFT SLIGHT CHANCE MENTION FOR THE FAR NORTHEAST CORNER OF MOHAVE COUNTY. && .PREV DISCUSSION...150 AM PDT FRI AUG 21 2015 .SHORT TERM...THROUGH MONDAY NIGHT. CLEAR SKIES DOMINATE THE FORECAST AREA EARLY THIS MORNING BUT THICK SMOKE CONTINUES TO BE PROBLEMATIC ACROSS THE OWENS VALLEY. I ANTICIPATE THE SMOKE WILL CONTINUE TO BE PREVAIL ACROSS THE OWENS VALLEY AGAIN TODAY...ESPECIALLY FROM BISHOP SOUTHWARD TO OLANCHA. ELSEWHERE...HAZE REMAINS POSSIBLE AS SMOKE FROM CALIFORNIA WILDFIRES DRIFTS WEST...THROUGH AFTERNOON BREEZY CONDITIONS MAY HELP MIX OUT THE HAZE AS IT DID THURSDAY...IMPROVING THE AIR QUALITY SOMEWHAT. THE BIGGEST CONCERN IN THE SHORT TERM PERIOD BESIDES THE SMOKE REVOLVES AROUND THUNDERSTORM CHANCES. MOISTURE HAS BEEN SEEPING INTO THE AREA UNDER A SOUTHERLY FLOW IN THE LOWER LEVELS OF THE ATMOSPHERE. DEWPOINTS EARLY THIS MORNING HAVE REACHED NEAR 60 DEGREES AT BULLHEAD CITY AND NEEDLES...AND MID 60S IN LAKE HAVASU. FURTHER SOUTH...THE DEWPOINT IN YUMA HAS SHOT UP TO 75F AND VAD WIND PROFILER DATA INDICATES A SOUTHERLY FLOW OF 15-20KTS IN THE LOWER 4K FEET OF THE ATMOSPHERE DRIVING THIS DEEPER MOISTURE NORTHWARD. WHILE MUCH OF THIS MOISTURE WILL MIX OUT WITH DAYTIME HEATING...THERE SHOULD STILL BE ENOUGH MOISTURE TO KICK OFF SOME ISOLATED CONVECTION ALONG THE HIGHER TERRAIN OF MOHAVE...EXTREME EASTERN SAN BERNARDINO...AND SOUTHERN CLARK COUNTIES THIS AFTERNOON AND EVENING. TROUBLE WILL BE THE LACK OF ANY SUBSTANCIAL TRIGGERING MECHANISM TO GET THINGS GOING. EARLY MORNING RUNS OF THE HRRR DO NOT PAINT A VERY PROMISING PICTURE FOR STORMS TODAY AND MOST MODEL GUIDANCE DOESNT DEVELOP ACTIVITY DESPITE THE INSTABILITY PRESENT. OPTED TO MAINTAIN THE SLIGHT CHANCE...TERRAIN ORIENTED POPS BUT CONFIDENCE IN DEVELOPMENT IS NOT REAL HIGH. SIMILAR OUTLOOK FOR SATURDAY WITH MARGINAL MOISTURE AND INSABILITY PRESENT...BUT NO REAL TRIGGER. ON SUNDAY...ANY DISCERNIBLE INSTABILITY GETS SHIFTED FURTHER EAST INTO FAR EASTERN MOHAVE COUNTY...SO KEPT POPS LIMITED TO THOSE FAR EASTERN ZONES AND CONDITIONS DRY ELSEWHERE. TEMPERATURES FRIDAY THROUGH THE WEEKEND WILL AVERAGE 3 TO 6 DEGREES ABOVE NORMAL. ON MONDAY...LEADING EDGE OF DEEPER MONSOON MOISTURE BEGINS TO LIFT INTO NORTHWEST ARIZONA AND EASTERN CALIFORNIA. BETTER MOISTURE AT THIS POINT LOOKS TO ARRIVE OVERNIGHT AND INTO TUESDAY BUT SOME ACTIVITY MAY BREAK OUT IN MOHAVE...EASTERN SAN BERNARDINO...AND THE HIGHER TERRAIN OF CLARK COUNTIES AND MAINTAINED POPS IN THESE AREAS. .LONG TERM...TUESDAY THROUGH FRIDAY. MODELS HAVE COME INTO BETTER LARGE SCALE AGREEMENT FOR MUCH OF THE PERIOD...BUT IMPORTANT DETAIL DIFFERENCES REMAIN. FOR TUESDAY...THE GFS LOOKS MUCH LIKE ITS PREVIOUS RUNS...BUT THE ECMWF DEPICTS THE FOUR CORNERS HIGH CENTER JUST A BIT FARTHER WEST...WHICH DELAYS THE MOISTURE RETURN AND SENDS HIGH TEMPERATURES ZOOMING BACK UP TO NEAR EXCESSIVE HEAT CRITERIA. WHILE THIS IS A POSSIBILITY...BELIEVE IT HAS A LOW PROBABILITY OF OCCURRENCE GIVEN MODEL TRENDS OVER THE PAST SEVERAL DAYS...AND HAVE GIVEN IT LITTLE WEIGHT IN THE FORECAST. THE GFS SOLUTION...WHICH SUGGESTS PRECIP CHANCES ROUGHLY NEAR AND EAST OF LAS VEGAS...WAS PREFERRED. FOR WEDNESDAY AND THURSDAY...MODELS HAVE COME INTO MUCH BETTER AGREEMENT WITH AMPLIFICATION OF BOTH THE NORTHERN STREAM LOW NEAR THE BRITISH COLUMBIA COAST AND THE RIDGE EXTENDING NORTH INTO SASKATCHEWAN FROM THE FOUR CORNERS HIGH. THIS LEAVES OUR CWA IN MOIST SOUTHERLY FLOW ON WEDNESDAY...TRANSITIONING INTO A SLIGHTLY DRIER SOUTHWEST FLOW ON THURSDAY AS TROUGHING IN THE EAST PACIFIC STRETCHES ALL THE WAY DOWN BELOW 30N. THERE IS DISAGREEMENT ON HOW TO EVOLVE THIS TROUGHING ON FRIDAY...BUT DECENT CONSENSUS THAT OUR SENSIBLE WEATHER WILL CHANGE LITTLE...WITH SOUTHWEST FLOW BRINGING MINIMAL PRECIP CHANCES BUT PERHAPS NOT STRONG ENOUGH TO SCOUR OUT LOW LEVEL MOISTURE...ESPECIALLY OVER MOHAVE COUNTY. && .AVIATION...FOR MCCARRAN...LIGHT SOUTHERLY DRAINAGE WINDS EXPECTED EARLY IN THE MORNING BEFORE BECOMING LIGHT AND VARIABLE SUNRISE THROUGH AROUND 17Z. A PERIOD OF SOUTHEAST WINDS OF 9-12KTS IS POSSIBLE BETWEEN 17Z AND 20Z BEFORE SOUTH-SOUTHWEST WINDS TAKE OVER IN THE AFTERNOON WITH GUSTS TO 25KTS. HAZY CONDITIONS REMAIN POSSIBLE. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...AREAS OF HAZE EXPECTED MAINLY NORTH OF INTERSTATE 40 AGAIN TODAY WITH SMOKE MOST CONCENTRATED NEAR THE SIERRA AND OWENS VALLEY. SMOKE MAY LOCALLY REDUCE VISIBILITIES TO BELOW 4 MILES. OTHERWISE...BREEZY SOUTH WINDS OF 12-18 KTS WITH GUSTS TO 25KTS EXPECTED ACROSS THE AREA IN THE AFTERNOON. SLIGHT CHANCES FOR ISOLATED THUNDERSTORMS EXIST IN THE HIGHER TERRAIN MAINLY SOUTH AND EAST OF KLAS THIS AFTERNOON. && .SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && $$ UPDATE...PIERCE SHORT TERM...OUTLER LONG TERM...MORGAN FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
331 PM MDT FRI AUG 21 2015 .SYNOPSIS... HIGH PRESSURE ALOFT WILL GRADUALLY BUILD OVER THE AREA THROUGH SATURDAY WITH DAYTIME TEMPERATURES REMAINING ABOVE NORMALS. BEST THUNDERSTORM COVERAGE WILL REMAIN FOCUSED OVER THE HIGHER TERRAIN AND SOUTHWEST SATURDAY AFTERNOON AND EVENING. THEREAFTER...ANOTHER SEASONABLY STRONG BACKDOOR FRONT WILL BOOST STORM COVERAGE ON SUNDAY ESPECIALLY FOR THE WESTERN AND SOUTHERN HALVES OF THE STATE. DAYTIME TEMPERATURES WILL DOWNWARD AGAIN...ESPECIALLY ACROSS THE EASTERN PLAINS WHERE HIGH TEMPERATURES ARE FORECAST TO BE BELOW NORMAL AND A GOOD 15 TO 25 DEGREES COOLER AS COMPARED TO SATURDAY. LOOKING AHEAD...AFTER A RELATIVELY ACTIVE DAY ON MONDAY A GRADUAL WARMING AND DRYING TREND WILL DOMINATE MUCH OF NEXT WEEK WITH STORM COVERAGE WANING EACH DAY THROUGH WEEK/S END. && .DISCUSSION... SUBTLE WAVE ALOFT/ASSOCIATED JET MAX TO TRANSLATE EAST OF THE AREA BY EARLY EVENING. LOOKS TO BE VISUAL EVIDENCE OF SUBSIDENCE EFFECTS IN THE IMMEDIATE FOUR CORNERS REGION. WILL NEED TO CAREFULLY MONITOR THE FAR NE...EC/SE PLAINS NEXT SEVERAL HOURS. A FAIRLY ATYPICAL SURFACE DRYLINE IN THE PROCESS OF SHARPENING EAST OF DES MOINES TO SANTA ROSA TO FORT SUMNER LINE /SFC DEW POINTS IN THE MID 20S TO MID 30S WEST OF THE DRYLINE WHILE MID 50S TO NEAR 60 COMMON TO THE EAST/ WITH A MORE DIFFUSE W-E GRADIENT OVER THE SOUTHEAST PLAINS. THIS BOUNDARY WILL LIKELY FOCUS A FEW STRONG IF NOT BRIEFLY SEVERE STORMS LATER THIS AFTERNOON INTO EARLY EVENING. OTHERWISE...BETTER MOISTURE PROFILES CONTINUE OVER SC/SW ZONES WHERE WE/LL CONTINUE TO FOCUS THE HIGHEST POPS. STORM MOTIONS GENERALLY TOWARD THE SE AT 15-20 KTS...AND COULD SEE A FEW PULSE STRONG STORMS WITH LOCALIZED GUSTY WINDS AND OF COURSE CG LIGHTNING THE MAIN THREATS. CONCEPTUAL MODEL WOULD ARGUE FOR A PRETTY QUIET PERIOD AFTER MIDNIGHT AS 500MB HEIGHTS SLOWLY BUILD FROM SW TO NE. BUT THE GFS/NAM AND NOT SURPRISINGLY HRRR REDEVELOP VERY ISOLATED QPF OVER THE WEST ESPECIALLY NORTHWEST. THIS MAY BE IN RESPONSE TO YET ANOTHER SPEED MAX WITHIN THE BASE OF YET ANOTHER VIGOROUS SHORTWAVE TROUGH THAT WILL CROSS THE CENTRAL/NORTHERN ROCKIES LATE TONIGHT. BEST GUESS IS WE COULD SEE SOME MID-LEVEL CLOUDINESS AND VIRGA SHOWERS/SPRINKLES DURING THE OVERNIGHT BUT HIGHLY DOUBT WE WOULD SEE A REPEAT OF EARLY MORNING T-STORMS. GOING INTO SATURDAY NIGHT AND SUNDAY...FOCUS WILL BE ON THE INCOMING BACKDOOR COLD FRONT THAT WILL FOLLOW IN WAKE OF THE ABOVE MENTIONED SHORTWAVE. TIMING OF THE FRONT SIMILAR TO PREVIOUS THINKING...INTO THE NORTHEAST SATURDAY EVENING PRESSING SOUTH AND WEST OVERNIGHT SATURDAY NIGHT INTO MIDDAY SUNDAY. LOOKS PRETTY COOL/STABLE ONCE AGAIN FOR THE NORTHEAST PLAINS...WITH THE FOCUS FOR CONVECTIVE PRECIP SHIFTING WEST AND SOUTH. THE MODELS HONESTLY LOOK A LITTLE UNDERCOOKED ON QPF FOR SUNDAY PM ESPECIALLY FOR AREAS BETWEEN THE DIVIDE AND EAST SLOPES OF THE CENTRAL MOUNTAIN CHAIN BUT THE CURRENT AIR MASS HAS NOT FULLY RECOVERED FROM THE LAST DRYING EVENT AND NOT A TREMENDOUSLY MOIST AIR MASS BEING USHERED IN WITH THIS FRONT. WILL SHOW AN UPWARD TREND IN POP COVERAGE FOR SUNDAY...BUT GENERALLY NOT AS DRY AT THE NAM WOULD SUGGEST. WARMER ON MONDAY AND WITH ANY ADDITIONAL MOISTURE INPUT ASSOCIATED WITH THE BACKDOOR PUSH WE EXPECT A DECENT INCREASE IN T-STORM ACTIVITY. 500MB HIGH CENTER GENERALLY EXPECTED OVER THE FOUR CORNERS OR PERHAPS A BIT EAST. STEERING WINDS WILL BE WEAK BUT GENERALLY FROM N TO S...SO NOT ALL BAD NEWS FOR THE RIO GRANDE VALLEY...NE AND CENTRAL HIGH PLAINS. RIDGE ALOFT FORECAST TO STRENGTHEN TUE INTO MID-WEEK BEFORE SHIFTING WESTWARD LATE WEEK. PROBABLY ANOTHER BACKDOOR COLD FRONT IN OUR FUTURE LATE THU OR FRI. KJ && .FIRE WEATHER... ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WITH WETTING RAIN WILL CONTINUE DEVELOPING THROUGHOUT THE AFTERNOON INTO THE EVENING ACROSS THE SOUTHWEST....SOUTH CENTRAL AND NORTHERN MOUNTAINS AND PORTIONS OF THE FAR EASTERN PLAINS. GUSTY AND ERRATIC WINDS WILL FOLLOW STORMS THAT PRODUCE OUTFLOW BOUNDARIES. SATURDAY WILL SEE ISOLATED TO SCATTERED STORMS FAVORING HIGH TERRAIN AREAS...WITH ABOVE NORMAL TEMPERATURES...HIGHER MIN RH VALUES IN THE SOUTHWEST MOUNTAINS WITH 5 HAINES VALUES ACROSS THE NORTHEAST AND EAST CENTRAL PLAINS. EXPECT BREEZY TO MODERATE WEST NORTHWEST WINDS DURING THE DAY. LATE SATURDAY INTO EARLY SUNDAY...A POTENT BACK DOOR FRONT WILL INVADE THE NORTHEAST...COOLING TEMPERATURES 5 TO 15 DEGREES BELOW NORMAL CENTRAL AND EAST WHILE WETTING RAIN CHANCES AND MIN RH VALUES TREND UPWARD CENTRAL AND WEST. EAST CANYON WINDS COULD PEAK 35 TO 45 MPH EARLY SUNDAY ALONG THE CENTRAL MOUNTAINS AS THE BACK DOOR FRONT PUSHES THROUGH THE GAPS TOWARD THE CONTINENTAL DIVIDE. BREEZY TO MODERATE EAST WINDS WILL CONTINUE THROUGHOUT THE DAY...BECOMING SOUTHEASTERLY BY THE LATE AFTERNOON...EARLY EVENING AS THE FRONT WASHES OUT. SO FAR...MODELS LOOK TO AGREE WITH A VERY ACTIVE MONDAY AS THE GFS HAS THE UPPER LEVEL HIGH OVER THE STATE WITH STORMS FAVORING CENTRAL AND WESTERN AREAS WHILE THE ECMWF HAS THE HIGH OVER THE GREAT BASIN AND IS MORE BULLISH FOR ACTIVITY TO FAVOR CENTRAL AND EASTERN AREAS. BY TUESDAY...GFS HAS THE HIGH LINGERING OVER THE STATE WHILE THE ECMWF HAS THE HIGH HOVERING OVER THE FOUR CORNERS REGION. OTHERWISE...TEMPERATURES LOOK TO REBOUND MONDAY AND TUESDAY IN THE EAST BECOMING ABOVE NORMAL BY THE MIDWEEK. GOOD TO EXCELLENT VENT RATES TODAY AND SATURDAY. BECOMING POOR CENTRAL AND NORTH SUNDAY...IMPROVING IN THE EAST MONDAY THROUGH WEDNESDAY. 32 && .AVIATION... 18Z TAF CYCLE SCT CIGS CURRENTLY DEVELOPING ACROSS MUCH OF WESTERN AND CENTRAL NEW MEXICO. LOOK FOR SHRA/TSRA ACTIVITY TO FAVOR THE SOUTHWEST...NORTHERN AND SOUTH CENTRAL MTNS THIS AFTERNOON. HAD LOW CONFIDENCE OF VCTS...SO KEPT VCSH FOR KABQ/KAEG...KSAF AND KROW. EXPECT BREEZY TO MODERATE NORTHWEST WINDS BETWEEN 19 AND 00Z ACROSS WESTERN AND CENTRAL AREAS. COULD SEE STORM CHANCES CONTINUE AFTER SUNSET ACROSS THE SOUTHWEST MTNS AND THE FAR EASTERN PLAINS. CML && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 60 91 59 90 / 10 5 10 10 DULCE........................... 48 85 49 84 / 10 10 10 20 CUBA............................ 53 82 53 80 / 10 20 10 20 GALLUP.......................... 55 86 54 86 / 30 20 20 30 EL MORRO........................ 52 82 51 80 / 30 20 20 50 GRANTS.......................... 55 84 53 80 / 30 20 20 20 QUEMADO......................... 56 82 54 80 / 30 30 30 40 GLENWOOD........................ 58 85 58 85 / 30 30 30 60 CHAMA........................... 47 79 47 77 / 10 40 20 30 LOS ALAMOS...................... 59 84 57 79 / 10 30 30 40 PECOS........................... 57 83 56 75 / 10 20 20 40 CERRO/QUESTA.................... 51 80 50 77 / 10 20 10 30 RED RIVER....................... 43 69 44 65 / 10 40 20 60 ANGEL FIRE...................... 46 72 46 67 / 10 20 30 40 TAOS............................ 46 84 50 78 / 10 20 10 20 MORA............................ 53 80 51 71 / 10 20 20 40 ESPANOLA........................ 57 89 56 84 / 10 10 10 10 SANTA FE........................ 60 85 58 79 / 10 20 10 20 SANTA FE AIRPORT................ 58 88 57 82 / 10 10 10 10 ALBUQUERQUE FOOTHILLS........... 64 90 63 84 / 20 10 10 10 ALBUQUERQUE HEIGHTS............. 67 92 64 86 / 20 10 10 10 ALBUQUERQUE VALLEY.............. 62 93 62 88 / 20 10 10 10 ALBUQUERQUE WEST MESA........... 65 94 63 88 / 10 10 10 10 LOS LUNAS....................... 64 93 62 87 / 20 10 10 10 RIO RANCHO...................... 65 93 63 87 / 10 10 10 10 SOCORRO......................... 66 94 63 89 / 20 10 20 10 SANDIA PARK/CEDAR CREST......... 58 86 57 79 / 20 20 10 20 TIJERAS......................... 57 88 56 80 / 20 10 10 10 MORIARTY/ESTANCIA............... 54 88 53 79 / 10 10 10 20 CLINES CORNERS.................. 58 85 54 75 / 10 10 10 20 GRAN QUIVIRA.................... 60 86 59 79 / 20 10 10 30 CARRIZOZO....................... 63 90 62 81 / 20 10 20 20 RUIDOSO......................... 60 82 56 74 / 20 30 30 30 CAPULIN......................... 57 84 53 73 / 10 20 30 10 RATON........................... 54 89 52 79 / 10 20 20 20 SPRINGER........................ 54 90 54 78 / 10 20 20 20 LAS VEGAS....................... 55 87 52 74 / 10 20 10 20 CLAYTON......................... 62 93 57 76 / 10 10 20 10 ROY............................. 59 90 56 73 / 10 20 20 10 CONCHAS......................... 64 96 61 78 / 10 10 20 10 SANTA ROSA...................... 62 95 61 79 / 10 10 20 10 TUCUMCARI....................... 65 98 63 79 / 10 10 20 10 CLOVIS.......................... 64 96 62 80 / 20 10 20 20 PORTALES........................ 65 96 64 81 / 20 10 20 20 FORT SUMNER..................... 66 97 64 79 / 10 10 20 10 ROSWELL......................... 68 101 67 86 / 20 10 20 30 PICACHO......................... 64 93 63 80 / 20 20 20 20 ELK............................. 63 86 61 76 / 20 20 20 40 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 41
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
601 PM EDT FRI AUG 21 2015 .SYNOPSIS... HIGH PRESSURE WILL BUILD SOUTHWARD FROM THE EASTERN GREAT LAKES THIS WEEKEND BRINGING DRIER WEATHER. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST TUESDAY WITH SCATTERED SHOWERS AND STORMS RETURNING TO THE FORECAST. FRONT STALLS IN THE AREA DURING THE MIDDLE OF THE WEAK AND SLOWLY DISSIPATES. DRIER AIR MAY MOVE INTO THE AREA FOR THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... AS OF 530 PM FRIDAY...THIS UPDATE WAS CONCERNED WITH THE INCREASED DEVELOPMENT OF CONVECTION ACROSS THE FA. MAINLY ITS A RESULT OF THE INTERACTION BETWEEN THE SEA BREEZE DRIFTING INLAND... AND THE COOL FRONT DROPPING/DRIFTING SE-WARD. HAVE A WIDE RANGE OF POPS ACROSS THE FA...MUCH OF IT ASSOCIATED WITH THE LATEST 88D TRENDS IN REGARD TO LATEST CONVECTIVE DEVELOPMENT AND MOVEMENT. HAVE ALSO UPPED QPF DUE TO WHAT THE LATEST 88DS ARE SPITTING OUT... AND ESPECIALLY WITH CURRENT AND PROGGED 2.00 THRU 2.25 INCH PRECIPITABLE WATER RANGES. PREVIOUS........................................................ AS OF 3 PM FRIDAY... THE COLD FRONT REMAINS TOUGH TO PICK OUT BUT BASED ON THE LATEST OBS INCLUDING WINDS AND DEWPOINT DEPRESSIONS IT APPEARS THAT THE FRONT IS BISECTING THE CWA FROM NE TO SW. IT APPEARS TO BE MERGING WITH THE SEA BREEZE FRONT OVER OUR NC COUNTIES...WHICH FURTHER COMPLICATES LOCATING THE COLD FRONT. CONVECTION HAS FINALLY COMMENCED WITH ISOLATED SHOWERS FORMING IN THE VICINITY OF THE COLD FRONT/SEA BREEZE FRONT CONGLOMERATION. EXPECT THAT THIS FRONTAL FEATURE WILL CONTINUE TO BE THE FOCUS FOR SCATTERED CONVECTION FOR THE REMAINDER OF THE AFTERNOON AND INTO THE EVENING HOURS...WITH ACTIVITY SHUTTING DOWN BY AROUND MIDNIGHT AS THIS IS ALL PRIMARILY DIURNALLY DRIVEN. A CONSENSUS OF GUIDANCE GIVES US A NORTH TO SOUTH TEMPERATURE GRADIENT...WITH LOWER 70S UP NORTH AND MID 70S TO THE SOUTH...AND ALSO MID 70S AT THE COAST. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...REMAINS OF WEAK FRONT OFF THE NC COAST AT THE START OF THE PERIOD WILL EXTEND WEST ACROSS NORTHERN SC. ALTHOUGH THE FRONT WILL BECOME QUITE DIFFUSE BY MIDDAY STILL THINK PRECIP CHANCES WILL REMAIN ELEVATED ACROSS PORTIONS OF SC. HIGH PRESSURE BUILDING IN FROM THE NORTH HELPS KEEP PRESSURE GRADIENT WEAK...WITH WEAK SEA BREEZE DEVELOPMENT IN THE AFTERNOON MASKING THE FRONT. MOISTURE POOLING ALONG THE FRONT COUPLED WITH DIURNAL HEATING IS LIKELY TO LEAD TO DEVELOPMENT OF AFTERNOON SHOWERS AND THUNDERSTORMS. HAVE MAINTAINED INHERITED CHC TO SLIGHT CHC POP ACROSS ILM SC COUNTIES. PRECIP SHOULD BE WEAKER AND DIURNAL IN NATURE SO ONCE SUN SETS DEBRIS CLOUD WILL LINGER BUT PRECIP COVERAGE SHOULD RAPIDLY DECREASE. TEMPERATURES SAT AND SAT NIGHT WILL BE NEAR CLIMO. WEAK SURFACE RIDGING REMAINS OVER THE EAST COAST SUN WITH MID LEVEL FLOW ALOFT BECOMING PROGRESSIVE. WEAK SHORTWAVE MOVES ACROSS THE SOUTHEAST LATER IN THE DAY...ACCOMPANIED BY AN INCREASED IN MID LEVEL MOISTURE. THE CORE OF THE SHORTWAVE PASSES SOUTH OF THE FORECAST AREA BUT PVA AHEAD OF IT COULD GENERATE SOME LATE AFTERNOON/EVENING CONVECTION ACROSS MAINLY THE SC COUNTIES. WILL CARRY AFTERNOON EVENING SLIGHT CHC/CHC POP TO COVER THE PASSAGE OF THE WAVE. DEPENDING ON THE SPEED OF THE WAVE CONVECTION COULD LINGER INTO THE OVERNIGHT PERIOD...BUT WEAK SUBSIDENCE FOLLOWING THE SHORTWAVE SHOULD END ANY CONVECTION BY DAY BREAK. TEMPERATURES WILL REMAIN NEAR CLIMO SUN AND SUN NIGHT. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 330 PM FRIDAY...SHORTWAVE WILL PUSH A COLD FRONT INTO THE CAROLINAS BUT IT LOOKS LIKE THIS FRONT WILL BECOME WASHED OUT AND LINGER JUST SOUTH OR OVER THE COASTAL CAROLINAS. A MID TO UPPER TROUGH DIGGING DOWN FROM THE GREAT LAKES WILL ALIGN WITH THIS SHORTWAVE LEAVING A DEEP TROUGH DOWN THE EAST COAST THROUGH MUCH OF THE UPCOMING WEEK. THE WINDS VEER AROUND TO THE NORTH ALOFT...BUT OVERALL REMAIN QUITE LIGHT AND VARIABLE WITHOUT MUCH OF A DRIVING FORCE TO THE FRONT. EXPECT GREATEST CHC OF PCP FARTHER INLAND ON MON AFTN AND SHOULD PUSH TOWARD THE COAST ON TUES. THIS BOUNDARY ALONG WITH LOCALIZED CONVERGENCE ALONG SEA BREEZE AND PIEDMONT TROUGH FURTHER INLAND WILL CONTRIBUTE TO DIURNAL CU DEVELOPMENT AND CONVECTIVE ACTIVITY. THE MODELS ARE NOT GENERATING TOO MUCH IN THE WAY OF QPF AND DO NOT EXPECT CONVECTION TO BE TOO WIDESPREAD...BUT LOCALIZED HEAVIER AMT ARE LIKELY IN STRONGER STORMS. ANOTHER SHORTWAVE WILL ROTATE AROUND MAIN TROUGH AND SHOULD ADVECT DRIER AIR IN FROM THE NORTHWEST BY THURS INTO FRI. PCP WATER VALUES UP CLOSER TO 1.75 INCHES WILL FALL DOWN BELOW 1.5 INCHES THURS INTO FRI PRIMARILY OVER INLAND TO NORTHWEST PORTIONS OF AREA. ESSENTIALLY EXPECT AN EXTENDED PERIOD OF UNSETTLED WEATHER WITH CU DEVELOPMENT EACH AFTN AS WELL AS DEBRIS CLOUDS AND GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS. THE INCREASED CHC OF CLOUDS AND CONVECTION ALONG WITH LOWERING OF H5 HEIGHT AND LOW LEVEL THICKNESSES WILL KEEP TEMPS NEAR OR BELOW NORMAL AFTER MONDAY. && .AVIATION /22Z FRIDAY THROUGH WEDNESDAY/... AS OF 18Z...FRONT SEEMS TO BE STALLED OVER THE SOUTHERN PORTION OF THE CWA. WINDS ARE NEARLY CALM...WITH A WEAK NORTHERLY COMPONENT THAT WILL BE REPLACED WITH A SOUTHEAST SEA BREEZE THIS AFTERNOON. THE HRRR DOES HAVE SOME WEAK CONVECTION WITH THE RESULTANT...ENOUGH FOR A VCSH MENTION. LIGHT WINDS TONIGHT WITH SOME STRATUS LIKELY RETURNING AFTER 06Z. SATURDAY...BECOMING VFR WITH NORTHEAST FLOW. ISOLATED CONVECTION IS EXPECTED...MAINLY ALONG THE RESULTANT AND OVER THE WESTERN PORTION OF THE CWA WHERE THE DEEPER MOISTURE WILL RESIDE. EXTENDED OUTLOOK...PREDOMINATELY VFR WITH SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THE EXTENDED. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 530 PM FRIDAY...THIS UPDATE CONCERNED WITH INCREASING CONVECTIVE POPS...MAINLY CLOSER TO SHORE DUE TO THE PCPN MOVING OFF THE MAINLAND. OTHERWISE...MAINTAINED THE BASICALLY VARIABLE WIND DIRECTION AT 10 KT OR LESS AHEAD OF THE COOL FRONT THIS EVENING. WINDS SHOULD ALL BECOME NE-ENE AFTER MIDNIGHT...WITH SPEEDS AROUND 10 KT. THE SFC PG DOES TIGHTEN AFTER THE CFP...BUT ITS DELAYED UNTIL DAYLIGHT SAT. PREVIOUS..................................................... AS OF 3 PM FRIDAY...WINDS WILL STAY LIGHT THROUGH THE NEAR TERM...BECOMING VARIABLE AT TIMES AS A COLD FRONT STALLS IN THE VICINITY. THESE LIGHT WINDS WILL KEEP SEAS MANAGEABLE...AT RIGHT AROUND 2 FT THROUGH THE PERIOD. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...HIGH PRESSURE TO THE NORTH WILL BUILD SOUTH WITH WEAK FRONT DISSIPATING OVER OR JUST EAST OF THE WATERS SATURDAY. HIGH PRESSURE REMAINS IN CONTROL THROUGH THE PERIOD WITH WEAK GRADIENT KEEPING WINDS LIGHT. INITIALLY WINDS WILL BE FROM THE NORTH-NORTHEAST BUT VEER TO SOUTHERLY DURING SAT. WINDS REMAIN SOUTHERLY THROUGH THE END OF THE PERIOD WITH SLIGHT INCREASES EACH AFTERNOON DUE TO SEA BREEZE DEVELOPMENT. SEAS WILL RUN 2 TO 3 FT. LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 330 PM FRIDAY...WINDS WILL HAVE A GREATER SOUTHERLY COMPONENT ON MONDAY AS COLD FRONT APPROACHES THE AREA. OVERALL EXPECT A LIGHTER PREVAILING WIND FLOW DOMINATED BY LAND/SEA BREEZE AS A COLD FRONT DROPS SOUTH AND WEAKENS. DIURNAL FLUCTUATIONS ARE EXPECTED WITH A SPIKE IN WINDS AND CHOPPIER SEAS EACH AFTN. AS FRONT LINGERS CLOUDS AND PCP MAY PLAY A ROLE EACH DAY IN STRENGTH OF SEA BREEZE. SEAS WILL BE PRIMARILY 2 TO 3 FT WITH A LONGER PERIOD UP TO 12 SEC SE SWELL MIXING IN MON NIGHT THROUGH MID WEEK FROM VERY DISTANT TROPICAL SYSTEM OUT IN THE TROPICAL ATLANTIC. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...III NEAR TERM...DCH/REK SHORT TERM...III LONG TERM...RGZ AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
357 PM EDT FRI AUG 21 2015 .SYNOPSIS... HIGH PRESSURE WILL BUILD SOUTHWARD FROM THE EASTERN GREAT LAKES THIS WEEKEND BRINGING DRIER WEATHER. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST TUESDAY WITH SCATTERED SHOWERS AND STORMS RETURNING TO THE FORECAST. FRONT STALLS IN THE AREA DURING THE MIDDLE OF THE WEAK AND SLOWLY DISSIPATES. DRIER AIR MAY MOVE INTO THE AREA FOR THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... AS OF 3 PM FRIDAY... THE COLD FRONT REMAINS TOUGH TO PICK OUT BUT BASED ON THE LATEST OBS INCLUDING WINDS AND DEWPOINT DEPRESSIONS IT APPEARS THAT THE FRONT IS BISECTING THE CWA FROM NE TO SW. IT APPEARS TO BE MERGING WITH THE SEA BREEZE FRONT OVER OUR NC COUNTIES...WHICH FURTHER COMPLICATES LOCATING THE COLD FRONT. CONVECTION HAS FINALLY COMMENCED WITH ISOLATED SHOWERS FORMING IN THE VICINITY OF THE COLD FRONT/SEA BREEZE FRONT CONGLOMERATION. EXPECT THAT THIS FRONTAL FEATURE WILL CONTINUE TO BE THE FOCUS FOR SCATTERED CONVECTION FOR THE REMAINDER OF THE AFTERNOON AND INTO THE EVENING HOURS...WITH ACTIVITY SHUTTING DOWN BY AROUND MIDNIGHT AS THIS IS ALL PRIMARILY DIURNALLY DRIVEN. A CONSENSUS OF GUIDANCE GIVES US A NORTH TO SOUTH TEMPERATURE GRADIENT...WITH LOWER 70S UP NORTH AND MID 70S TO THE SOUTH...AND ALSO MID 70S AT THE COAST. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...REMAINS OF WEAK FRONT OFF THE NC COAST AT THE START OF THE PERIOD WILL EXTEND WEST ACROSS NORTHERN SC. ALTHOUGH THE FRONT WILL BECOME QUITE DIFFUSE BY MIDDAY STILL THINK PRECIP CHANCES WILL REMAIN ELEVATED ACROSS PORTIONS OF SC. HIGH PRESSURE BUILDING IN FROM THE NORTH HELPS KEEP PRESSURE GRADIENT WEAK...WITH WEAK SEA BREEZE DEVELOPMENT IN THE AFTERNOON MASKING THE FRONT. MOISTURE POOLING ALONG THE FRONT COUPLED WITH DIURNAL HEATING IS LIKELY TO LEAD TO DEVELOPMENT OF AFTERNOON SHOWERS AND THUNDERSTORMS. HAVE MAINTAINED INHERITED CHC TO SLIGHT CHC POP ACROSS ILM SC COUNTIES. PRECIP SHOULD BE WEAKER AND DIURNAL IN NATURE SO ONCE SUN SETS DEBRIS CLOUD WILL LINGER BUT PRECIP COVERAGE SHOULD RAPIDLY DECREASE. TEMPERATURES SAT AND SAT NIGHT WILL BE NEAR CLIMO. WEAK SURFACE RIDGING REMAINS OVER THE EAST COAST SUN WITH MID LEVEL FLOW ALOFT BECOMING PROGRESSIVE. WEAK SHORTWAVE MOVES ACROSS THE SOUTHEAST LATER IN THE DAY...ACCOMPANIED BY AN INCREASED IN MID LEVEL MOISTURE. THE CORE OF THE SHORTWAVE PASSES SOUTH OF THE FORECAST AREA BUT PVA AHEAD OF IT COULD GENERATE SOME LATE AFTERNOON/EVENING CONVECTION ACROSS MAINLY THE SC COUNTIES. WILL CARRY AFTERNOON EVENING SLIGHT CHC/CHC POP TO COVER THE PASSAGE OF THE WAVE. DEPENDING ON THE SPEED OF THE WAVE CONVECTION COULD LINGER INTO THE OVERNIGHT PERIOD...BUT WEAK SUBSIDENCE FOLLOWING THE SHORTWAVE SHOULD END ANY CONVECTION BY DAY BREAK. TEMPERATURES WILL REMAIN NEAR CLIMO SUN AND SUN NIGHT. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 330 PM FRIDAY...SHORTWAVE WILL PUSH A COLD FRONT INTO THE CAROLINAS BUT IT LOOKS LIKE THIS FRONT WILL BECOME WASHED OUT AND LINGER JUST SOUTH OR OVER THE COASTAL CAROLINAS. A MID TO UPPER TROUGH DIGGING DOWN FROM THE GREAT LAKES WILL ALIGN WITH THIS SHORTWAVE LEAVING A DEEP TROUGH DOWN THE EAST COAST THROUGH MUCH OF THE UPCOMING WEEK. THE WINDS VEER AROUND TO THE NORTH ALOFT...BUT OVERALL REMAIN QUITE LIGHT AND VARIABLE WITHOUT MUCH OF A DRIVING FORCE TO THE FRONT. EXPECT GREATEST CHC OF PCP FARTHER INLAND ON MON AFTN AND SHOULD PUSH TOWARD THE COAST ON TUES. THIS BOUNDARY ALONG WITH LOCALIZED CONVERGENCE ALONG SEA BREEZE AND PIEDMONT TROUGH FURTHER INLAND WILL CONTRIBUTE TO DIURNAL CU DEVELOPMENT AND CONVECTIVE ACTIVITY. THE MODELS ARE NOT GENERATING TOO MUCH IN THE WAY OF QPF AND DO NOT EXPECT CONVECTION TO BE TOO WIDESPREAD...BUT LOCALIZED HEAVIER AMTS ARE LIKELY IN STRONGER STORMS. ANOTHER SHORTWAVE WILL ROTATE AROUND MAIN TROUGH AND SHOULD ADVECT DRIER AIR IN FROM THE NORTHWEST BY THURS INTO FRI. PCP WATER VALUES UP CLOSER TO 1.75 INCHES WILL FALL DOWN BELOW 1.5 INCHES THURS INTO FRI PRIMARILY OVER INLAND TO NORTHWEST PORTIONS OF AREA. ESSENTIALLY EXPECT AN EXTENDED PERIOD OF UNSETTLED WEATHER WITH CU DEVELOPMENT EACH AFTN AS WELL AS DEBRIS CLOUDS AND GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS. THE INCREASED CHC OF CLOUDS AND CONVECTION ALONG WITH LOWERING OF H5 HEIGHT AND LOW LEVEL THICKNESSES WILL KEEP TEMPS NEAR OR BELOW NORMAL AFTER MONDAY. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... AS OF 18Z...FRONT SEEMS TO BE STALLED OVER THE SOUTHERN PORTION OF THE CWA. WINDS ARE NEARLY CALM...WITH A WEAK NORTHERLY COMPONENT THAT WILL BE REPLACED WITH A SOUTHEAST SEA BREEZE THIS AFTERNOON. THE HRRR DOES HAVE SOME WEAK CONVECTION WITH THE RESULTANT...ENOUGH FOR A VCSH MENTION. LIGHT WINDS TONIGHT WITH SOME STRATUS LIKELY RETURNING AFTER 06Z. SATURDAY...BECOMING VFR WITH NORTHEAST FLOW. ISOLATED CONVECTION IS EXPECTED...MAINLY ALONG THE RESULTANT AND OVER THE WESTERN PORTION OF THE CWA WHERE THE DEEPER MOISTURE WILL RESIDE. EXTENDED OUTLOOK...PREDOMINATELY VFR WITH SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THE EXTENDED. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM FRIDAY...WINDS WILL STAY LIGHT THROUGH THE NEAR TERM...BECOMING VARIABLE AT TIMES AS A COLD FRONT STALLS IN THE VICINITY. THESE LIGHT WINDS WILL KEEP SEAS MANAGEABLE...AT RIGHT AROUND 2 FT THROUGH THE PERIOD. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...HIGH PRESSURE TO THE NORTH WILL BUILD SOUTH WITH WEAK FRONT DISSIPATING OVER OR JUST EAST OF THE WATERS SATURDAY. HIGH PRESSURE REMAINS IN CONTROL THROUGH THE PERIOD WITH WEAK GRADIENT KEEPING WINDS LIGHT. INITIALLY WINDS WILL BE FROM THE NORTH-NORTHEAST BUT VEER TO SOUTHERLY DURING SAT. WINDS REMAIN SOUTHERLY THROUGH THE END OF THE PERIOD WITH SLIGHT INCREASES EACH AFTERNOON DUE TO SEA BREEZE DEVELOPMENT. SEAS WILL RUN 2 TO 3 FT. LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 330 PM FRIDAY...WINDS WILL HAVE A GREATER SOUTHERLY COMPONENT ON MONDAY AS COLD FRONT APPROACHES THE AREA. OVERALL EXPECT A LIGHTER PREVAILING WIND FLOW DOMINATED BY LAND/SEA BREEZE AS A COLD FRONT DROPS SOUTH AND WEAKENS. DIURNAL FLUCTUATIONS ARE EXPECTED WITH A SPIKE IN WINDS AND CHOPPIER SEAS EACH AFTN. AS FRONT LINGERS CLOUDS AND PCP MAY PLAY A ROLE EACH DAY IN STRENGTH OF SEA BREEZE. SEAS WILL BE PRIMARILY 2 TO 3 FT WITH A LONGER PERIOD UP TO 12 SEC SE SWELL MIXING IN MON NIGHT THROUGH MID WEEK FROM VERY DISTANT TROPICAL SYSTEM OUT IN THE TROPICAL ATLANTIC. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...REK SHORT TERM...III LONG TERM...RGZ AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
130 PM EDT FRI AUG 21 2015 .SYNOPSIS... A COLD FRONT WILL WAVER ACROSS THE AREA TODAY...BRINGING A RENEWED CHANCE FOR SHOWERS AND THUNDERSTORMS. MOSTLY SUNNY AND SEASONABLE WEATHER WILL FOLLOW FOR THE WEEKEND BEHIND THIS FRONT. WARMER AND MORE HUMID AIR WILL RETURN NEXT WEEK AHEAD OF A COLD FRONT WHICH WILL APPROACH ON TUESDAY...AND THEN STALL ACROSS THE AREA THROUGH THURSDAY BRINGING COOLER AND UNSETTLED CONDITIONS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 130 PM FRIDAY...AS EXPECTED...STILL WAITING ON THE FIRST SIGNIFICANT CONVECTION OF THE DAY TO FIRE OFF. AN EXTENSIVE CU FIELD HAS DEVELOPED HOWEVER...AND GIVEN STRONG HEATING AND A MOIST COLUMN WILL LIKELY SEE OUR FIRST SHOWERS OF THE DAY FORM SOON. RETAINING CHANCE POPS FOR THIS AFTERNOON/EVENING. PREVIOUS DISCUSSIONS FOLLOW: HARD TO PICK OUT THE FRONT THIS MORNING. BASED ON WIND DIRECTIONS IT APPEARS TO BE WAVERING ACROSS THE AREA AND MAY BE JUST OFFSHORE AT THIS TIME. ANALYSIS OF MORNING SOUNDING DATA SHOWS A VERY MOIST ATMOSPHERE WITH DEWPOINTS WELL IN THE 70S AND P/W VALUES APPROACHING 2.25 INCHES. NAM IS STILL LIKING SCATTERED CONVECTION THIS AFTERNOON...ESPECIALLY NEAR THE COAST...ALTHOUGH THE HRRR CONTINUES IN A MORE MODEST VEIN...WITH ISOLATED SEA-BREEZE CONVECTION FIRING UP THIS AFTERNOON. KEEPING PRESENT CHANCE POPS IN PLACE AS WITH SUCH A MOIST COLUMN IT WILL NOT TAKE MUCH TO KICK OFF CONVECTION. PREVIOUS DISCUSSION FOLLOWS: DESPITE GREAT MODEL-TO-MODEL CONSISTENCY 24 HOURS AGO THE COLD FRONT IS LAGGING THOSE PROGS BY NEARLY 100 MILES THIS MORNING. AT 6 AM THE FRONT APPEARS TO LIE ROUGHLY ALONG A LINE FROM ELIZABETHTOWN AND WHITEVILLE TO MYRTLE BEACH AND GEORGETOWN. THIS IS ANALYZED MORE BY PRESSURE THAN WIND SINCE WINDS ARE NEARLY CALM ON EITHER SIDE OF THE BOUNDARY. THE FRONT SHOULD CROSS THE NORTH CAROLINA BEACHES IN THE NEXT 1-2 HOURS...BUT WITH LITTLE WIND BEHIND THE FRONT THERE WILL BE NO SIGNIFICANT AIRMASS CHANGE. TEMPERATURES RISING INTO THE LOWER 90S INLAND THIS AFTERNOON SHOULD TRIGGER A SEABREEZE WHICH WILL MOVE THE EFFECTIVE LOCATION OF THE FRONT BACK INLAND DUE TO DEVELOPING ONSHORE WINDS ALONG THE COAST. WITH DEWPOINTS HOLDING IN THE LOWER 70S SURFACE-BASED INSTABILITY SHOULD GROW TO 1000-2000 J/KG THIS AFTERNOON. SYNOPTIC AND FINE- SCALE MODELS ALL SHOW THE POTENTIAL FOR AT LEAST SCATTERED SHOWERS AND STORMS THIS AFTERNOON...MOST NUMEROUS NEAR THE COAST WHERE SEABREEZE-ENHANCED CONVERGENCE WILL ASSIST THE GROWING CUMULUS CLOUDS. FORECAST POPS RANGE FROM 20 PERCENT INLAND TO 30-40 PERCENT ON THE COAST. LIGHT TROPOSPHERIC WINDS MEAN ANY CONVECTION WILL LIKELY BE DISORGANIZED PULSE-TYPE WITH NO SIGNIFICANT POTENTIAL FOR SEVERE WEATHER. DAYTIME CLOUDS WILL BE SLOW TO CLEAR TONIGHT ESPECIALLY ACROSS SOUTH CAROLINA WHERE A MID-LEVEL DISTURBANCE IS PROGGED TO MOVE IN FROM THE WEST DURING THE EVENING HOURS. THIS SHOULD SPREAD MID-LEVEL CLOUDS EASTWARD TOWARD THE COAST. A SMALL CHANCE OF SHOWERS AND STORMS WILL BE MAINTAINED OVERNIGHT ACROSS THE PEE DEE REGION DUE TO THE MOISTURE ADVECTING EASTWARD...AND OVERNIGHT LOWS HAVE BEEN ADJUSTED UPWARD DUE TO LESS RADIATIONAL COOLING EXPECTED. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...A BEAUTIFUL WKND IN STORE AS A COLD FRONT WILL BE WELL SOUTH OF THE AREA...LEAVING DRYING AND MOSTLY SUNNY CONDITIONS FOR SATURDAY AND SUNDAY. SATURDAY STILL HAS A CHANCE FOR SOME ISOLATED SHOWERS/TSTMS ACROSS THE SOUTHERN TIER OF ZONES WHERE PWATS WILL BE HIGHER AND THE FRONT WILL STILL BE IN THE VICINITY...POTENTIALLY INTERACTING WITH A WEAK SHORTWAVE MOVING IN FROM THE MIDLANDS OF SC...BUT NOT EXPECTING WIDESPREAD OR HEAVY CONVECTION...AND INTENSITY/COVERAGE WILL DECREASE THROUGH THE AFTN/EVE ON THE DRY ADVECTION. SUNDAY STILL SHAPING UP TO BE A GORGEOUS DAY...ALTHOUGH FLOW IS PROGGED TO RETURN TO THE SW EARLIER THAN PREVIOUSLY. THIS WILL CAUSE TEMPS TO BE WARMER...ALONG WITH SLIGHTLY HIGHER HUMIDITY THAN PREVIOUSLY FORECAST...BUT STILL EXPECT BRIGHT SUNSHINE AND A GREAT LATE- AUGUST DAY. TEMPS SATURDAY WILL BE AROUND SEASONABLE LEVELS AS COOL ADVECTION IS LACKING BEHIND THE FRONT. EXPECT HIGHS AROUND 87 FAR NW TO ABOUT 90 ALONG THE SOUTHERN TIER. MAX TEMPS ON SUNDAY WILL BE ABOUT 1-3 DEGREES WARMER EVERYWHERE. SUB-CLIMO MINS SATURDAY NIGHT THANKS TO THE DRY COLUMN...AND LOWS WILL DROP INTO THE REFRESHING CATEGORY...DROPPING INTO THE MID 60S WELL NW TO AROUND 70 AT THE COAST. MORE TYPICAL MINS SUNDAY NIGHT WITH LOWS A DEGREE OR TWO EITHER SIDE OF 70. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 300 AM FRIDAY...MID-LEVEL FLOW TO BECOME ANOMALOUSLY AMPLIFIED FOR AUGUST MUCH OF THE UPCOMING WEEK AS A LARGE TROUGH DEVELOPS ACROSS THE EAST WITH A BIG RIDGE BLOSSOMING OVER THE MTN WEST. ALTHOUGH MONDAY WILL FEATURE WARM TEMPS...POSSIBLY ABOVE NORMAL...WITH TYPICAL SUMMERTIME CONVECTION CHANCES...THIS IS LOOKING TO BE THE ONE ABOVE-NORMAL DAY OF THE PERIOD. THEREAFTER A COLD FRONT DROPS INTO THE CAROLINAS AND STALLS THROUGH MID-WEEK BEFORE FINALLY GETTING PUSHED SOUTH LATE WED INTO THU. THIS WILL CREATE AN EXTENDED PERIOD OF UNSETTLED WEATHER WITH GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS...ALONG WITH SUB-CLIMO TEMPS THANKS TO LOWERED THICKNESSES WITHIN THE TROUGH COMBINING WITH CLOUDS AND PRECIP. HARD TO SAY THE ENTIRE TUE-THU PERIOD WILL BE WET AND CLOUDY...BUT AT LEAST A GOOD PORTION OF EACH DAY LOOKS TO BE UNSETTLED WITH HIGHS SLIGHTLY BELOW CLIMO AND LOWS SLIGHTLY ABOVE AS DIURNAL RANGES BECOME COMPRESSED && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AS OF 18Z...FRONT SEEMS TO BE STALLED OVER THE SOUTHERN PORTION OF THE CWA. WINDS ARE NEARLY CALM...WITH A WEAK NORTHERLY COMPONENT THAT WILL BE REPLACED WITH A SOUTHEAST SEA BREEZE THIS AFTERNOON. THE HRRR DOES HAVE SOME WEAK CONVECTION WITH THE RESULTANT...ENOUGH FOR A VCSH MENTION. LIGHT WINDS TONIGHT WITH SOME STRATUS LIKELY RETURNING AFTER 06Z. SATURDAY...BECOMING VFR WITH NORTHEAST FLOW. ISOLATED CONVECTION IS EXPECTED...MAINLY ALONG THE RESULTANT AND OVER THE WESTERN PORTION OF THE CWA WHERE THE DEEPER MOISTURE WILL RESIDE. EXTENDED OUTLOOK...PREDOMINATELY VFR WITH SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THE EXTENDED. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM FRIDAY...LIGHT AND VARIABLE WINDS WITH 2 FT WAVES CONTINUE OVER THE WATERS THIS AFTERNOON AS A COLD FRONT WAVERS IN THE VICINITY. NO CHANGES TO THE FORECAST WITH THE LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS: SLOW-MOVING COLD FRONT SHOULD MOVE OFF THE BEACHES SHORTLY AFTER SUNRISE THIS MORNING. WESTERLY WINDS IN ADVANCE OF THE FRONT WILL VEER NORTHERLY LATER THIS MORNING BUT WITH NO INCREASE IN WIND SPEED. BY THIS AFTERNOON THE TYPICAL SEABREEZE CIRCULATION SHOULD OVERWHELM WHAT LITTLE WIND EXISTS BEHIND THE FRONT...WITH ONSHORE WINDS 10 KNOTS OR LESS EXPECTED ALL ALONG THE COAST. ENOUGH MOISTURE WILL REMAIN BEHIND THE FRONT THAT A FEW SHOWERS AND STORMS SHOULD FIRE UP DURING THE AFTERNOON HOURS NEAR THE COAST ALONG THE SEABREEZE BOUNDARY. STEERING WINDS ALOFT WILL BE LIGHT AND FROM THE NORTHWEST...PERHAPS PUSHING ANY OF THIS ISOLATED SHOWER/STORM ACTIVITY OUT ACROSS THE BEACHES AND INTO THE COASTAL WATERS. A NORTH-NORTHEAST WIND WILL GRADUALLY INCREASE LATE TONIGHT... REACHING 10-15 KNOTS LATE. SEAS SHOULD AVERAGE ONLY 2 FEET TODAY AND TONIGHT...PERHAPS BUILDING TO 3 FEET IN EXPOSED WATERS LATE. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...HIGH PRESSURE RIDGING DOWN THE COAST BEHIND A COLD FRONT WILL CREATE N/NE WINDS SATURDAY AND THE FIRST HALF OF SUNDAY. THE GRADIENT ASSOCIATED WITH THIS HIGH PRESSURE IS WEAK...SO WIND SPEEDS WILL BE 10 KTS OR LESS FROM THIS DIRECTION...AFTER A BRIEF SURGE UP TO 15 KTS EARLY SATURDAY. LATE SUNDAY...RETURN FLOW WILL BEGIN TO REDEVELOP AS WINDS SHIFT BACK AROUND TO THE SW BUT AT CONTINUED LIGHT SPEEDS. WAVE HEIGHTS WILL BE 2-3 FT EARLY DURING THE RESIDUAL NE SURGE...BUT FALL TO 1-2 FT SATURDAY AFTN AND PERSIST AT THESE AMPLITUDES THROUGH THE WIND SHIFT AND INTO THE END OF THE PERIOD LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 300 AM FRIDAY...SW WINDS AHEAD OF A COLD FRONT WILL INCREASE STEADILY DURING MONDAY...RISING UP TOWARDS 15 KTS LATE IN THE DAY. AS THE COLD FRONT APPROACHES WINDS WILL EASE A BIT MONDAY NIGHT...BUT THIS FRONT WILL LIKELY NOT REACH THE WATERS DURING TUESDAY AND INSTEAD STALL JUST INLAND. THIS WILL CONTINUE S/SW WINDS TUESDAY AT 10-15 KTS. SEAS WILL BE PRIMARILY 2-3 FT THROUGH THE PERIOD WITH A SE GROUND SWELL AND WEAK WIND WAVE COMPRISING THE SPECTRUM. LATE MONDAY AND INTO TUESDAY...SOME 12-SEC PERIOD SWELL FROM DISTANT TROPICAL SYSTEMS MAY ENTER THE SPECTRUM...BUT WILL BE AT 1 FT OR LESS IN AMPLITUDE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JDW NEAR TERM...REK/TRA SHORT TERM...JDW LONG TERM...JDW AVIATION...DL MARINE...REK/TRA/JDW
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1208 PM CDT FRI AUG 21 2015 .UPDATE... ISSUED AT 1210 PM CDT FRI AUG 21 2015 SMOKE CONTINUES TO SLOW TEMP RISE TODAY...AND WILL LOWER A FEW MORE DEGREES FOR ALL AREAS. OTHERWISE...NO OTHER CHANGES NEEDED TODAY. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 345 AM CDT FRI AUG 21 2015 FORECAST CHALLENGES WILL BE SEVERE THREAT SATURDAY AS WELL AS RAINFALL AMOUNTS MAINLY THIS WEEKEND AND TEMPERATURES/WIND. MODELS OVERALL IN PRETTY GOOD AGREEMENT THROUGH THE PERIOD AND WILL USE MODEL BLEND. CURRENT SHORTWAVE PROPAGATING EAST ACROSS SW MB INTO ONTARIO THIS MORNING. ASSOCIATED AREA OF SHRA/ISOLD T ON NOSE OF LOW LEVEL JET IN WARM ADVECTION ZONE. ALTHOUGH INSTABILITY AND CAPE MINIMAL A FEW LIGHTNING STRIKES OCCURRING. CURRENT HRRR WEAKENS PCPN THROUGH THE MORNING AND OUT OF THE FA BY MID MORNING. WILL MAINTAIN LOW POPS BASED ON SHORT TERM MODEL GUIDANCE. THE REMAINDER OF THIS AFTERNOON SHOULD REMAIN DRY. CONTINUED WARM ADVECTION WILL SET UP WARM FRONTAL BOUNDARY ALONG THE INTERNATIONAL BORDER BY THIS EVENING. WITH FA IN WARM SECTOR TEMPERATURES SHOULD RECOVER WELL WITH MOST AREAS ABOVE AVERAGE. TONIGHT MORE SIGNIFICANT WAVE CURRENTLY OVER BC WILL DIG INTO THE NORTHERN ROCKIES. ASSOCIATED SURFACE LOW WILL ORGANIZE OVER THE WESTERN DAKOTAS WITH SW-NE ORIENTED BOUNDARY SETTING UP LATER IN THE NIGHT. WILL CONTINUE WITH CHANCE POPS ALONG THIS BOUNDARY. TEMPERATURES WILL REMAIN MILD OVERNIGHT. SURFACE LOW WILL LIFT NE SATURDAY AS WAVE APPROACHES. AS IT DOES ASSOCIATED COLD FRONT WILL FOLLOW LOW AND BE ORIENTED CLOSE TO THE VALLEY BY PRIME HEATING. CONVECTIVE PARAMETERS FAVORABLE FOR SEVERE STORMS ALONG AND AHEAD OF THE BOUNDARY SO SEVERE POTENTIAL WILL HINGE ON JUST WHERE BOUNDARY SETS UP. DEGREE OF CLOUD COVER WILL GOVERN TEMPERATURES WITH COOLEST READINGS OVER THE FAR NW WHICH WILL BE BEHIND THE COLD FRONT. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 345 AM CDT FRI AUG 21 2015 UPPER TROUGH CLOSES OFF SATURDAY NIGHT AS IT LIFTS NE. WRAP AROUND/DEF ZONE RAIN WILL FOLLOW. AT THIS POINT MODEL GUIDANCE SUGGESTS THAT THE BEST POTENTIAL FOR RAIN WILL BE OVER THE NORTHERN 2/3RD OF THE FA. SUNDAY WILL BE WINDY AND COOLER WITH DEF ZONE PCPN BAND SHIFTING EAST ACROSS THE FA. COOLER COLUMN AND CLOUDS WILL HOLD TEMPERATURES DOWN. RAIN WILL MOVE OUT OF THE NE FA SUNDAY NIGHT. WINDS TO DIMINISH BUT WILL BE A COOL NIGHT WITH MINIMUM TEMPERATURES IN THE 40S. LONG WAVE TROUGHS WERE OFF THE WESTERN CANADIAN COAST AND THE GREAT LAKES WITH A FLAT RIDGE OVER MT. PATTERN AMPLIFIES WITH A TROUGH OVER THE EASTERN PACIFIC/WESTERN CANADA AND RIDGING INTO THE NORTHERN PLAINS BY THE END OF THE PERIOD. GFS AND ECMWF WERE IN BETTER AGREEMENT WITH TODAYS MODEL RUN THROUGH THE PERIOD. THE ECMWF WAS SLIGHTLY FASTER THAN THE GFS. THE ECMWF WAS VACILLATING AROUND A POINT WHILE THE GFS WAS TRENDING SLOWER OVER THE LAST COUPLE MODEL RUNS. NO CHANGE TO HIGH TEMPS FOR MON. HIGH TEMPS WERE DECREASED A DEGREE OR TWO FOR TUE AND WED, AND INCREASED ZERO TO FOUR DEGREES FOR THU FORM YESTERDAYS PACKAGE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1210 PM CDT FRI AUG 21 2015 VFR CONDITIONS FCST TO CONTINUE THROUGH THE PERIOD WITH MAINLY MID AND HIGH LEVEL CIGS. SFC HIGH PRESSURE WILL RETREAT THIS AFTERNOON AND EVENING...WITH WINDS BECOMING SOUTHERLY FROM 10 TO 20 MPH AHEAD OF DEVELOPING LOW PRESSURE MOVG ACROSS THE HIGH PLAINS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...DK SHORT TERM...VOELKER LONG TERM...HOPPES/VOELKER AVIATION...HOPKINS
AREA FORECAST DISCUSSION
NWS NORMAN OK
600 PM CDT FRI AUG 21 2015 .AVIATION... EXPECT TO SEE SOME SHWR/TSTMS IMPACT MOST SITES LATER THIS EVENING WITH ASSOCAITED MVFR CONDITIONS. WITH VFR RETURNING OVERNIGHT AND CONT THROUGH THE DAY ON SATURDAY. MUCH LIKE TODAY... SOUTH WINDS WILL INCREASE DURING THE DAY SATURDAY WITH GUSTS OF 20 TO 25KTS EXPECTED BY LATE MORNING INTO THE AFTN HOURS. 30 && .PREV DISCUSSION... /ISSUED 218 PM CDT FRI AUG 21 2015/ .DISCUSSION... PRIMARY FORECAST CONCERN LIES WITH THUNDERSTORM CHANCES THIS EVENING AND OVERNIGHT. CURRENTLY... STOUT MID-LEVEL SHORT WAVE CONTINUES TO DIG ACROSS NERN NM/SERN CO INTO THE NRN PANHANDLES. AHEAD OF THIS WAVE... WAA HAS INCREASED ACROSS WRN N TX INTO WRN OK... IN RESPONSE... LL CLOUDS CONTINUE TO DISSIPATE ACROSS NRN TX/SRN INTO CENTRAL OK. FROM 15Z FORWARD... EACH PROGRESSIVE RUN OF THE HRRR HAS BECOME MORE AGGRESSIVE WITH CONVECTIVE DEVELOPMENT OVER THE ERN PANHANDLES AND ACROSS WRN OK/WRN N TX INTO CENTRAL/SOUTH CENTRAL OK OVERNIGHT. TIMING HAS BEEN RELATIVELY CONSISTENT FROM RUN TO RUN... AND SIMILAR TO TRADITIONAL GUIDANCE FROM THE NAM/GFS/ECMWF. WITH THAT SAID... CURRENT EXPECTATIONS IS FOR INITIAL CONVECTION TO DEVELOP OVER THE NRN TX PH/OK PH BETWEEN 21-23Z (4-6 PM CDT)... MOVING E/SE INTO WRN OK THROUGH 23-01Z (6-8 PM CDT). WITH CLEARING SKIES... INSTABILITY WILL INCREASE ACROSS THE WRN TX PH/WRN OK... 1000 TO 1500 J/KG ALONG WITH 30 TO 40KTS OF DEEP LAYER SHEAR. ASCENT FOR FORCING IS CONFINED TO THE MID-LEVELS... 850/700MB... THEREFORE... EXPECT CONVECTION TO BE ELEVATED... AND BUFR SOUNDINGS SUPPORT THIS... WITH LCLS BETWEEN 2000 TO 3000 FT AGL. PRIMARY CONCERN WILL BE LARGE HAIL... POSSIBLY UP TO GOLF BALL SIZE... DAMAGING WINDS UP TO 60 MPH AND FREQUENT LIGHTNING. LOCALLY HEAVY RAINFALL IS ALSO POSSIBLE... WITH PWATS IN THE 75TH PERCENTILE... 1.40-1.60IN... HOWEVER... THE MID-LEVEL SHORT WAVE IS MOVING AT A DECENT CLIP... SO HYDRO IMPACTS SHOULD BE MINIMAL AS STORMS WILL BE MOVING OUT QUICKLY THROUGH THE EARLY MORNING HOURS OF SATURDAY. SATURDAY MORNING... THE CHANCE FOR STRONG TO SEVERE STORMS WILL WANE QUICKLY THROUGH MIDNIGHT... WITH SCATTERED CONVECTION CONTINUING ACROSS CENTRAL INTO ERN OK THROUGH DAWN. MOST OF THE REMAINING STORMS WILL STILL RETAIN THE ABILITY TO PRODUCE 40 MPH GUSTS AND FREQUENT LIGHTNING. LATE SATURDAY MORNING AND AFTERNOON... SOME LINGERING SHOWERS MAY HANG AROUND... BUT DRY WEATHER CAN BE EXPECTED AS WAA INCREASES AGAIN AHEAD OF COLD FRONT THAT WILL BE MOVING IN FROM THE NW DURING THE AFTN IN RESPONSE TO A STRONG H500 SHORT WAVE SWINGING ACROSS THE NRN PLAINS. THIS FRONT WILL DROP S/SE INTO THE SRN PLAINS SAT NIGHT THROUGH SUN MORNING... BRINGING A GOOD CHANCE OF PRECIP TO THE REGION OVERNIGHT AS PWATS WILL RANGE FROM 1.5 TO 1.70IN AHEAD OF THE FRONT OVERNIGHT. GUIDANCE REMAINS IN DECENT AGREEMENT... WITH THE FRONT MOVING FAIRLY QUICKLY... PUSHING TO THE RED RIVER THROUGH EARLY/MID MORNING. PRECIP AMOUNTS BETWEEN 0.50 AND 1.00 IN... WITH THE BEST CHANCES ACROSS NRN OK OVERNIGHT. NO SEVERE WEATHER IS EXPECTED AT THIS TIME... ALTHOUGH A FEW STRONGER STORMS MAY BE CAPABLE OF 40 TO 45 MPH GUSTS. AFTER SUNDAY... THE H500 RIDGE WILL CONTINUE TO BUILD OVER THE SWRN U.S... WITH GOOD CONSISTENCY BETWEEN RUNS OVER THE PAST FEW DAYS. THIS WILL BODE WELL FOR TEMPS ACROSS THE REGION... KEEPING THE SRN PLAINS NEAR NORMAL... WITH HIGHS IN THE UPPER 80S/LOWER 90S INTO NEXT WEEK. HOWEVER... RESIDING UNDER THE ERN EDGE OF THE RIDGE... THERE WILL BE A NEAR DAILY CHANCE OF ISOLATED TO SCATTERED THUNDERSTORMS ACROSS THE REGION IN RESPONSE TO A SERIES OF SHORT WAVES TRAVERSING THE LARGER RIDGE THROUGH THE END OF NEXT WEEK. THE BEST CHANCE FOR PRECIP NEXT WEEK WILL BE MON INTO TUE AS THE WEEKEND FRONT LIFTS TOWARD THE RED RIVER AS A WEAK WARM FRONT... BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS TO TEXOMA AND WRN AND CENTRAL OK. JTK && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 71 92 71 84 / 40 10 60 30 HOBART OK 71 96 72 85 / 60 10 40 30 WICHITA FALLS TX 74 97 75 93 / 40 10 20 40 GAGE OK 69 94 65 80 / 60 0 60 20 PONCA CITY OK 72 91 67 82 / 40 20 70 10 DURANT OK 73 94 75 93 / 40 10 10 30 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$
AREA FORECAST DISCUSSION
NWS NORMAN OK
218 PM CDT FRI AUG 21 2015 .DISCUSSION... PRIMARY FORECAST CONCERN LIES WITH THUNDERSTORM CHANCES THIS EVENING AND OVERNIGHT. CURRENTLY... STOUT MID-LEVEL SHORT WAVE CONTINUES TO DIG ACROSS NERN NM/SERN CO INTO THE NRN PANHANDLES. AHEAD OF THIS WAVE... WAA HAS INCREASED ACROSS WRN N TX INTO WRN OK... IN RESPONSE... LL CLOUDS CONTINUE TO DISSIPATE ACROSS NRN TX/SRN INTO CENTRAL OK. FROM 15Z FORWARD... EACH PROGRESSIVE RUN OF THE HRRR HAS BECOME MORE AGGRESSIVE WITH CONVECTIVE DEVELOPMENT OVER THE ERN PANHANDLES AND ACROSS WRN OK/WRN N TX INTO CENTRAL/SOUTH CENTRAL OK OVERNIGHT. TIMING HAS BEEN RELATIVELY CONSISTENT FROM RUN TO RUN... AND SIMILAR TO TRADITIONAL GUIDANCE FROM THE NAM/GFS/ECMWF. WITH THAT SAID... CURRENT EXPECTATIONS IS FOR INITIAL CONVECTION TO DEVELOP OVER THE NRN TX PH/OK PH BETWEEN 21-23Z (4-6 PM CDT)... MOVING E/SE INTO WRN OK THROUGH 23-01Z (6-8 PM CDT). WITH CLEARING SKIES... INSTABILITY WILL INCREASE ACROSS THE WRN TX PH/WRN OK... 1000 TO 1500 J/KG ALONG WITH 30 TO 40KTS OF DEEP LAYER SHEAR. ASCENT FOR FORCING IS CONFINED TO THE MID-LEVELS... 850/700MB... THEREFORE... EXPECT CONVECTION TO BE ELEVATED... AND BUFR SOUNDINGS SUPPORT THIS... WITH LCLS BETWEEN 2000 TO 3000 FT AGL. PRIMARY CONCERN WILL BE LARGE HAIL... POSSIBLY UP TO GOLF BALL SIZE... DAMAGING WINDS UP TO 60 MPH AND FREQUENT LIGHTNING. LOCALLY HEAVY RAINFALL IS ALSO POSSIBLE... WITH PWATS IN THE 75TH PERCENTILE... 1.40-1.60IN... HOWEVER... THE MID-LEVEL SHORT WAVE IS MOVING AT A DECENT CLIP... SO HYDRO IMPACTS SHOULD BE MINIMAL AS STORMS WILL BE MOVING OUT QUICKLY THROUGH THE EARLY MORNING HOURS OF SATURDAY. SATURDAY MORNING... THE CHANCE FOR STRONG TO SEVERE STORMS WILL WANE QUICKLY THROUGH MIDNIGHT... WITH SCATTERED CONVECTION CONTINUING ACROSS CENTRAL INTO ERN OK THROUGH DAWN. MOST OF THE REMAINING STORMS WILL STILL RETAIN THE ABILITY TO PRODUCE 40 MPH GUSTS AND FREQUENT LIGHTNING. LATE SATURDAY MORNING AND AFTERNOON... SOME LINGERING SHOWERS MAY HANG AROUND... BUT DRY WEATHER CAN BE EXPECTED AS WAA INCREASES AGAIN AHEAD OF COLD FRONT THAT WILL BE MOVING IN FROM THE NW DURING THE AFTN IN RESPONSE TO A STRONG H500 SHORT WAVE SWINGING ACROSS THE NRN PLAINS. THIS FRONT WILL DROP S/SE INTO THE SRN PLAINS SAT NIGHT THROUGH SUN MORNING... BRINGING A GOOD CHANCE OF PRECIP TO THE REGION OVERNIGHT AS PWATS WILL RANGE FROM 1.5 TO 1.70IN AHEAD OF THE FRONT OVERNIGHT. GUIDANCE REMAINS IN DECENT AGREEMENT... WITH THE FRONT MOVING FAIRLY QUICKLY... PUSHING TO THE RED RIVER THROUGH EARLY/MID MORNING. PRECIP AMOUNTS BETWEEN 0.50 AND 1.00 IN... WITH THE BEST CHANCES ACROSS NRN OK OVERNIGHT. NO SEVERE WEATHER IS EXPECTED AT THIS TIME... ALTHOUGH A FEW STRONGER STORMS MAY BE CAPABLE OF 40 TO 45 MPH GUSTS. AFTER SUNDAY... THE H500 RIDGE WILL CONTINUE TO BUILD OVER THE SWRN U.S... WITH GOOD CONSISTENCY BETWEEN RUNS OVER THE PAST FEW DAYS. THIS WILL BODE WELL FOR TEMPS ACROSS THE REGION... KEEPING THE SRN PLAINS NEAR NORMAL... WITH HIGHS IN THE UPPER 80S/LOWER 90S INTO NEXT WEEK. HOWEVER... RESIDING UNDER THE ERN EDGE OF THE RIDGE... THERE WILL BE A NEAR DAILY CHANCE OF ISOLATED TO SCATTERED THUNDERSTORMS ACROSS THE REGION IN RESPONSE TO A SERIES OF SHORT WAVES TRAVERSING THE LARGER RIDGE THROUGH THE END OF NEXT WEEK. THE BEST CHANCE FOR PRECIP NEXT WEEK WILL BE MON INTO TUE AS THE WEEKEND FRONT LIFTS TOWARD THE RED RIVER AS A WEAK WARM FRONT... BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS TO TEXOMA AND WRN AND CENTRAL OK. JTK && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 71 92 71 84 / 40 10 60 30 HOBART OK 71 96 72 85 / 60 10 40 30 WICHITA FALLS TX 74 97 75 93 / 40 10 20 40 GAGE OK 69 94 65 80 / 60 0 60 20 PONCA CITY OK 72 91 67 82 / 40 20 70 10 DURANT OK 73 94 75 93 / 40 10 10 30 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
516 PM EDT FRI AUG 21 2015 .SYNOPSIS... H PRESSURE WILL CONTINUE TO BUILD IN FROM THE NORTH...THOUGH MUCH DRYING IN THE WAKE OF THE FRONTAL PASSAGE IS UNLIKELY. ANOTHER COLD FRONT WILL CROSS THE REGION ON MONDAY...WITH A MUCH DRIER PERIOD STARTING ON TUESDAY. ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS WILL RETURN BY THE END OF NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... AS OF 510PM FRIDAY...AREA IS CURRENTLY CLEAR OF ALL BUT THE LIGHTEST ISOLATED SHOWERS. LATEST HRRR ALSO HAS NO NEW CONVECTION IN THE NEAR FUTURE. CONVECTION THAT EARLIER CAMS HAD BY 18Z HAS NOT MATERIALIZED. HAVE THUS LOWERED THE PRECIP. FORECAST FOR THE NEXT 6 HOURS. AS OF 200 PM...HIGH PRESSURE CONTINUES TO RIDGE DOWN THE EAST COAST IN A WEDGE-LIKE CONFIGURATION. SFC FRONT NOW STRETCHES FROM MIDDLE GA THRU THE SC MIDLANDS...WITH NE WINDS AND RELATIVELY DRY DEWPTS ACRS MOST OF THE AREA. PATCHY MIDLEVEL CLOUDS REMAIN ACRS MUCH OF THE CWFA RESULTING FROM A WEAK VORT MAX DRIFTING ACRS THE AREA. THIS DECK APPEARS THINNER THAN IT DID LATE THIS MRNG...AND AS THE VORT MAX CONTINUES TO MOVE EAST IT SHOULD FOLLOW. A SHALLOW CU FIELD HAS QUICKLY BROKEN OUT AS SUNSHINE RETURNS...PARTICULARLY OVER THE MTNS OF SW NC AND NE GA...AND NOW THE UPPER SAVANNAH RIVER VALLEY. A COUPLE SHOWERS ARE ALSO SEEN ON RADAR TO OUR WEST. SHORT RANGE CAM GUIDANCE HAS GENERALLY OVERDONE THE STATE OF CONVECTION THIS MORNING POSSIBLY BECAUSE THEY UNDERESTIMATED THE RESTRICTED WARMING ASSOC WITH THE CLOUD COVER. THE HRRR HAS TRENDED TOWARD MORE ISOLATED COVERAGE. SEEING THE RATHER WEAK ACTIVITY UPSTREAM SUPPORTS MAINLY ISOLD RANGE POPS THIS AFTN. A SECOND VORT MAX OVER NRN ALABAMA WILL ARRIVE THIS EVENING...AND ENOUGH ELEVATED INSTABILITY AND LOW LEVEL MOISTURE WILL STILL BE PRESENT FOR ISOLATED CONVECTION TO OCCUR TONIGHT OVER MUCH OF THE AREA. DESPITE HIGH PRESSURE ALREADY HAVING BEGUN TO SETTLE INTO THE AREA AS OF THIS AFTERNOON...APPRECIABLE DRYING DOES NOT OCCUR UNTIL TOMORROW. ANY CONVECTIVE SHOWERS THAT OCCUR THIS AFTN OR TONIGHT ARE LIKELY TO PRODUCE HIGH RAINFALL RATES. MIN TEMPS WILL BE SLIGHTLY ABOVE CLIMO TONIGHT WITH A FAIR AMOUNT OF CLOUD COVER...GIVEN THE UPPER DISTURBANCE AND MOIST FLOW INTO THE BLUE RIDGE. SUBSIDENCE CAPPING IS EXPECTED TO KEEP CONVECTION ISOLATED OR TOTALLY AT BAY OVER MUCH OF THE NC PIEDMONT ON SATURDAY...AND SCATTERED AT BEST AROUND THE FRINGES OF THE AIRMASS /IN THE MTNS AND SAVANNAH VALLEY/. THE ARRIVAL OF DRIER AIR ALOFT IMPLIES GUSTY/STRONG WINDS MAY BE OF A BIT MORE CONCERN...AND HEAVY RAIN A BIT LESS. MAX TEMPS AGAIN WILL BE SLIGHTLY BELOW NORMAL. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... AS OF 200 PM EDT FRIDAY...THE SHORT TERM FCST PERIOD INITIALIZES SATURDAY EVENING WITH THE UPPER PATTERN HIGHLIGHTED BY AN EASTERN GULF ANTICYCLONE...WHILE A SHORTWAVE TROF SLIDES THROUGH THE MIDSOUTH...WITH A DEEPER LONGWAVE TROF ADVECTING OVER THE UPPER MIDWEST. AT THE SFC...RELATIVELY DRIER NORTHERLY FLOW WILL PREVAIL OVER THE WESTERN CAROLINAS AND NORTHEAST GEORGIA CONSEQUENT OF ELONGATED HIGH PRESSURE MOVING EAST OF THE SOUTHERN/CENTRAL APPS. MODELS HINT AT ISOLATED/SCATTERED CONVECTION POSSIBLE AT FCST INITIALIZATION ACROSS THE AREA...HOWEVER MAINLY FOCUSED OVER THE NC/GA HIGH TERRAIN AND THE UPPER SAVANNAH RIVER VALLEY. EXPECTING THE UPPER SHORT WAVE TO ADVECT FURTHER EAST THROUGH THE NIGHT WARRANTING MENTIONABLE POPS THROUGH MORNING OVER THE WEST...SPREADING EAST AND INCREASING INTO THE AFTERNOON. THUS THE FCST FEATURES CHANCE POPS DURING THE DAY ON SUNDAY. MEANWHILE...A COLD FRONT WILL BE MOVING THROUGH THE MID MISSISSIPPI RIVER VALLEY INTO THE OHIO VALLEY BY EARLY MONDAY MORNING...ENTERING THE NC HIGH TERRAIN LATE AFTERNOON TO EARLY EVENING MONDAY. STILL SOME UNCERTAINTY AS TO HOW UNSTABLE THE AIRMASS WILL BE OUT AHEAD OF THE FRONT HOWEVER WITH THE LATEST THE NAM COMING IN MORE SO THAN PREVIOUS RUNS. THUS...WOULDNT BE SURPRISED TO SEE CONVECTION IN THE WARM SECTOR MONDAY AFTERNOON AHEAD/ALONG THE FRONT. FORTUNATELY...THE MOST ENHANCED UPPER WIND FIELD WILL BE WELL TO THE NORTH ALONG WITH THE PRIMARY UPPER LOW. THEREFORE SOUNDINGS FAVOR MORE OF A HAIL AND HYDRO THREAT AT THIS TIME...WITH EVEN THAT BEING ISOLATED. POPS ON MONDAY WILL FEATURE CHANCE LEVELS OVER THE HIGH TERRAIN TAPERING TO SLIGHT CHANCE LEVELS EAST ALONG THE I77 CORRIDOR. AS FOR HURRICANE DANNY...LATEST ADVISORY ISSUANCE FROM NHC INDICATES SOME WEAKENING THIS WEEKEND AS IT ENCOUNTERS DRIER AIR WITH THE CENTER OF CIRCULATION JUST OFF THE EAST COAST OF PUERTO RICO BY MONDAY AFTERNOON...LIKELY IN THE FORM OF A TROPICAL STORM. TEMPERATURES THROUGH THE PERIOD WILL SLOWLY MODERATE...WITH NEAR NORMAL HIGHS FCST ON SUNDAY AND HIGHS JUST ABOVE NORMAL ON MONDAY. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... OF 200 PM FRIDAY...OVERALL MODEL AGREEMENT FOR THE MEDIUM RANGE IS ABOVE AVERAGE. THE UPPER PATTERN WILL CONTINUE TO AMPLIFY...WITH A SUBSTANTIAL RIDGE STILL IN PLACE OVER THE WESTERN CONUS AND A RAPIDLY DEEPENING TROUGH OVER THE EAST. AT THE SURFACE...THE APPROACHING FRONTAL BOUNDARY WILL MOVE THROUGH THE CWFA AT THE BEGINNING OF THE PERIOD. DESPITE THE FRONTAL PASSAGE COINCIDING WITH PEAK HEATING...DEEP NORTHWESTERLY FLOW WILL DRIVE SOME LEVEL OF DRYING BEFORE THE BOUNDARY ARRIVES. MODERATE INSTABILITY IS POSSIBLE IN THE HIGHER TERRAIN...BUT IS UNIMPRESSIVE ELSEWHERE. THOUGH THERE IS SOME QPF RESPONSE AS THE FRONT PASSES...A LACK OF DEEP MOISTURE AND LESS THAN THRILLING SHEAR PROFILES SHOULD KEEP CHANCES OF CONVECTION TO NO MORE THAN CHANCE OUTSIDE THE MOUNTAINS...AND HIGH-END CHANCE IN THE HIGHER TERRAIN. AN UNUSUALLY QUIET PERIOD...ESPECIALLY FOR THE END OF SUMMER...WILL ARRIVE AFTER THE FRONT CROSSES THE CWA. A SURFACE HIGH WILL BUILD IN FROM THE OHIO RIVER VALLEY...AND PWATS DROP TO WELL BELOW NORMAL. A NORTHERLY COMPONENT IS MAINTAINED IN THE SURFACE WINDS FOR ALMOST THE ENTIRE MEDIUM RANGE...SO KEEP A "SILENT 10" POP IN EACH AFTERNOON FOR THE MAJORITY OF THE AREA. SLIGHT CHANCE POPS WERE USED BORDERING COLUMBIA`S AREA...WITH ANY CHANCE AT CONVECTION FOLLOWING THE BETTER INSTABILITY. THE UPPER PATTERN WILL FLATTEN OUT BY THE END OF NEXT WEEK...AND THE INFLUENCE OF ATLANTIC HIGH PRESSURE WILL BUILD BACK IN. THIS INFLUENCE WILL BE REFLECTED IN A SLIGHT MOISTENING DUE TO AN INCREASED SOUTHERLY FLOW AT THE SURFACE. MAX AND MIN TEMPS WILL BE NEAR CLIMO THROUGH THE PERIOD. && .AVIATION /21Z FRIDAY THROUGH WEDNESDAY/... AT KCLT...VFR. A PASSING UPPER DISTURBANCE THIS AFTERNOON WILL MAINTAIN A FAIR AMOUNT OF HIGH CLOUD COVER AND LIMIT DESTABILIZATION...SO EVEN THOUGH LOW VFR CU WILL DEVELOP THEY ARE UNLIKELY TO BECOME DEEP ENOUGH FOR ANY PRECIP TO RESULT. HIGH PRESSURE WILL CONTINUE TO BUILD DOWN THE EAST COAST REINFORCING NELY WINDS...THOUGH THEY ARE EXPECTED TO VEER SLIGHTLY SOUTH OF EAST FOR A TIME THIS EVENING. A SECOND DISTURBANCE ARRIVING TONIGHT WILL BRING ADDITIONAL CLOUD COVER AND A BETTER CHANCE FOR LIGHT SHOWERS...BOTH OF WHICH ARE EXPECTED TO CAUSE LITTLE IMPACT. WINDS WILL RETURN TO NE AFTER DAYBREAK. ELSEWHERE...IN THE WAKE OF ONE UPPER DISTURBANCE...HIGHER CLOUDS SHOULD MOVE EAST AND RETURNING SUNSHINE WILL ALLOW CUMULUS TO BUILD IN THEIR WAKE. ISOLD TO WIDELY SCATTERED SHRA AND PERHAPS A TSRA OR TWO HAS PROMPTED A VCSH MENTION AT KGSP/KGMU. A SECOND DISTURBANCE ARRIVING TONIGHT WILL BRING BETTER CHANCES TO MOST OF THE AREA...BUT STILL ONLY VCSH WORTHY AT BEST. SOME FOG IS EXPECTED IN MTN VALLEYS AND IN THE SAVANNAH RIVER VALLEY...TAKING KAVL/KAND DOWN TO MVFR IN THE EARLY MRNG. POPS DIMINISH AFTER DAYBREAK AS THE DISTURBANCE DEPARTS...BEFORE RAMPING UP AGAIN TOWARD MIDDAY WITH DIURNAL DESTABILIZATION. WINDS WILL REFLECT THE HIGH PRESSURE RIDGING DOWN THE EAST SIDE OF THE APPALACHIANS IN A REGIME SIMILAR TO A CAD WEDGE...MAINLY NE OVER THE PIEDMONT AND SE AT KAVL. OUTLOOK...DRY HIGH PRESSURE WILL MAINTAIN LOW POTENTIAL FOR MORNING RESTRICTIONS THROUGH THE WEEKEND. A RETURN TO A TYPICAL DIURNAL CYCLE OF CONVECTION MAY OCCUR EARLY NEXT WEEK AS A COLD FRONT ARRIVES FROM THE NORTHWEST. CONFIDENCE TABLE... 21-03Z 03-09Z 09-15Z 15-18Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 87% KAVL HIGH 96% HIGH 100% HIGH 90% HIGH 82% KHKY HIGH 100% HIGH 100% LOW 55% MED 72% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 95% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...LEV NEAR TERM...WIMBERLEY/WJM SHORT TERM...CDG LONG TERM...LEV AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
237 PM EDT FRI AUG 21 2015 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE NORTH...THOUGH MUCH DRYING IN THE WAKE OF THE FRONTAL PASSAGE IS UNLIKELY. ANOTHER COLD FRONT WILL CROSS THE REGION ON MONDAY...WITH A MUCH DRIER PERIOD STARTING ON TUESDAY. ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS WILL RETURN BY THE END OF NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... AS OF 230 PM...HIGH PRESSURE CONTINUES TO RIDGE DOWN THE EAST COAST IN A WEDGE-LIKE CONFIGURATION. SFC FRONT NOW STRETCHES FROM MIDDLE GA THRU THE SC MIDLANDS...WITH NE WINDS AND RELATIVELY DRY DEWPTS ACRS MOST OF THE AREA. PATCHY MIDLEVEL CLOUDS REMAIN ACRS MUCH OF THE CWFA RESULTING FROM A WEAK VORT MAX DRIFTING ACRS THE AREA. THIS DECK APPEARS THINNER THAN IT DID LATE THIS MRNG...AND AS THE VORT MAX CONTINUES TO MOVE EAST IT SHOULD FOLLOW. A SHALLOW CU FIELD HAS QUICKLY BROKEN OUT AS SUNSHINE RETURNS...PARTICULARLY OVER THE MTNS OF SW NC AND NE GA...AND NOW THE UPPER SAVANNAH RIVER VALLEY. A COUPLE SHOWERS ARE ALSO SEEN ON RADAR TO OUR WEST. SHORT RANGE CAM GUIDANCE HAS GENERALLY OVERDONE THE STATE OF CONVECTION THIS MORNING POSSIBLY BECAUSE THEY UNDERESTIMATED THE RESTRICTED WARMING ASSOC WITH THE CLOUD COVER. THE HRRR HAS TRENDED TOWARD MORE ISOLATED COVERAGE. SEEING THE RATHER WEAK ACTIVITY UPSTREAM SUPPORTS MAINLY ISOLD RANGE POPS THIS AFTN. A SECOND VORT MAX OVER NRN ALABAMA WILL ARRIVE THIS EVENING...AND ENOUGH ELEVATED INSTABILITY AND LOW LEVEL MOISTURE WILL STILL BE PRESENT FOR ISOLATED CONVECTION TO OCCUR TONIGHT OVER MUCH OF THE AREA. DESPITE HIGH PRESSURE ALREADY HAVING BEGUN TO SETTLE INTO THE AREA AS OF THIS AFTERNOON...APPRECIABLE DRYING DOES NOT OCCUR UNTIL TOMORROW. ANY CONVECTIVE SHOWERS THAT OCCUR THIS AFTN OR TONIGHT ARE LIKELY TO PRODUCE HIGH RAINFALL RATES. MIN TEMPS WILL BE SLIGHTLY ABOVE CLIMO TONIGHT WITH A FAIR AMOUNT OF CLOUD COVER...GIVEN THE UPPER DISTURBANCE AND MOIST FLOW INTO THE BLUE RIDGE. SUBSIDENCE CAPPING IS EXPECTED TO KEEP CONVECTION ISOLATED OR TOTALLY AT BAY OVER MUCH OF THE NC PIEDMONT ON SATURDAY...AND SCATTERED AT BEST AROUND THE FRINGES OF THE AIRMASS /IN THE MTNS AND SAVANNAH VALLEY/. THE ARRIVAL OF DRIER AIR ALOFT IMPLIES GUSTY/STRONG WINDS MAY BE OF A BIT MORE CONCERN...AND HEAVY RAIN A BIT LESS. MAX TEMPS AGAIN WILL BE SLIGHTLY BELOW NORMAL. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... AS OF 200 PM EDT FRIDAY...THE SHORT TERM FCST PERIOD INITIALIZES SATURDAY EVENING WITH THE UPPER PATTERN HIGHLIGHTED BY AN EASTERN GULF ANTICYCLONE...WHILE A SHORTWAVE TROF SLIDES THROUGH THE MIDSOUTH...WITH A DEEPER LONGWAVE TROF ADVECTING OVER THE UPPER MIDWEST. AT THE SFC...RELATIVELY DRIER NORTHERLY FLOW WILL PREVAIL OVER THE WESTERN CAROLINAS AND NORTHEAST GEORGIA CONSEQUENT OF ELONGATED HIGH PRESSURE MOVING EAST OF THE SOUTHERN/CENTRAL APPS. MODELS HINT AT ISOLATED/SCATTERED CONVECTION POSSIBLE AT FCST INITIALIZATION ACROSS THE AREA...HOWEVER MAINLY FOCUSED OVER THE NC/GA HIGH TERRAIN AND THE UPPER SAVANNAH RIVER VALLEY. EXPECTING THE UPPER SHORT WAVE TO ADVECT FURTHER EAST THROUGH THE NIGHT WARRANTING MENTIONABLE POPS THROUGH MORNING OVER THE WEST...SPREADING EAST AND INCREASING INTO THE AFTERNOON. THUS THE FCST FEATURES CHANCE POPS DURING THE DAY ON SUNDAY. MEANWHILE...A COLD FRONT WILL BE MOVING THROUGH THE MID MISSISSIPPI RIVER VALLEY INTO THE OHIO VALLEY BY EARLY MONDAY MORNING...ENTERING THE NC HIGH TERRAIN LATE AFTERNOON TO EARLY EVENING MONDAY. STILL SOME UNCERTAINTY AS TO HOW UNSTABLE THE AIRMASS WILL BE OUT AHEAD OF THE FRONT HOWEVER WITH THE LATEST THE NAM COMING IN MORE SO THAN PREVIOUS RUNS. THUS...WOULDNT BE SURPRISED TO SEE CONVECTION IN THE WARM SECTOR MONDAY AFTERNOON AHEAD/ALONG THE FRONT. FORTUNATELY...THE MOST ENHANCED UPPER WIND FIELD WILL BE WELL TO THE NORTH ALONG WITH THE PRIMARY UPPER LOW. THEREFORE SOUNDINGS FAVOR MORE OF A HAIL AND HYDRO THREAT AT THIS TIME...WITH EVEN THAT BEING ISOLATED. POPS ON MONDAY WILL FEATURE CHANCE LEVELS OVER THE HIGH TERRAIN TAPERING TO SLIGHT CHANCE LEVELS EAST ALONG THE I77 CORRIDOR. AS FOR HURRICANE DANNY...LATEST ADVISORY ISSUANCE FROM NHC INDICATES SOME WEAKENING THIS WEEKEND AS IT ENCOUNTERS DRIER AIR WITH THE CENTER OF CIRCULATION JUST OFF THE EAST COAST OF PUERTO RICO BY MONDAY AFTERNOON...LIKELY IN THE FORM OF A TROPICAL STORM. TEMPERATURES THROUGH THE PERIOD WILL SLOWLY MODERATE...WITH NEAR NORMAL HIGHS FCST ON SUNDAY AND HIGHS JUST ABOVE NORMAL ON MONDAY. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 200 PM FRIDAY...OVERALL MODEL AGREEMENT FOR THE MEDIUM RANGE IS ABOVE AVERAGE. THE UPPER PATTERN WILL CONTINUE TO AMPLIFY...WITH A SUBSTANTIAL RIDGE STILL IN PLACE OVER THE WESTERN CONUS AND A RAPIDLY DEEPENING TROUGH OVER THE EAST. AT THE SURFACE...THE APPROACHING FRONTAL BOUNDARY WILL MOVE THROUGH THE CWFA AT THE BEGINNING OF THE PERIOD. DESPITE THE FRONTAL PASSAGE COINCIDING WITH PEAK HEATING...DEEP NORTHWESTERLY FLOW WILL DRIVE SOME LEVEL OF DRYING BEFORE THE BOUNDARY ARRIVES. MODERATE INSTABILITY IS POSSIBLE IN THE HIGHER TERRAIN...BUT IS UNIMPRESSIVE ELSEWHERE. THOUGH THERE IS SOME QPF RESPONSE AS THE FRONT PASSES...A LACK OF DEEP MOISTURE AND LESS THAN THRILLING SHEAR PROFILES SHOULD KEEP CHANCES OF CONVECTION TO NO MORE THAN CHANCE OUTSIDE THE MOUNTAINS...AND HIGH-END CHANCE IN THE HIGHER TERRAIN. AN UNUSUALLY QUIET PERIOD...ESPECIALLY FOR THE END OF SUMMER...WILL ARRIVE AFTER THE FRONT CROSSES THE CWA. A SURFACE HIGH WILL BUILD IN FROM THE OHIO RIVER VALLEY...AND PWATS DROP TO WELL BELOW NORMAL. A NORTHERLY COMPONENT IS MAINTAINED IN THE SURFACE WINDS FOR ALMOST THE ENTIRE MEDIUM RANGE...SO KEEP A "SILENT 10" POP IN EACH AFTERNOON FOR THE MAJORITY OF THE AREA. SLIGHT CHANCE POPS WERE USED BORDERING COLUMBIA`S AREA...WITH ANY CHANCE AT CONVECTION FOLLOWING THE BETTER INSTABILITY. THE UPPER PATTERN WILL FLATTEN OUT BY THE END OF NEXT WEEK...AND THE INFLUENCE OF ATLANTIC HIGH PRESSURE WILL BUILD BACK IN. THIS INFLUENCE WILL BE REFLECTED IN A SLIGHT MOISTENING DUE TO AN INCREASED SOUTHERLY FLOW AT THE SURFACE. MAX AND MIN TEMPS WILL BE NEAR CLIMO THROUGH THE PERIOD. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... AT KCLT...VFR. A PASSING UPPER DISTURBANCE THIS AFTERNOON WILL MAINTAIN A FAIR AMOUNT OF HIGH CLOUD COVER AND LIMIT DESTABILIZATION...SO EVEN THOUGH LOW VFR CU WILL DEVELOP THEY ARE UNLIKELY TO BECOME DEEP ENOUGH FOR ANY PRECIP TO RESULT. HIGH PRESSURE WILL CONTINUE TO BUILD DOWN THE EAST COAST REINFORCING NELY WINDS...THOUGH THEY ARE EXPECTED TO VEER SLIGHTLY SOUTH OF EAST FOR A TIME THIS EVENING. A SECOND DISTURBANCE ARRIVING TONIGHT WILL BRING ADDITIONAL CLOUD COVER AND A BETTER CHANCE FOR LIGHT SHOWERS...BOTH OF WHICH ARE EXPECTED TO CAUSE LITTLE IMPACT. WINDS WILL RETURN TO NE AFTER DAYBREAK. ELSEWHERE...IN THE WAKE OF ONE UPPER DISTURBANCE...HIGHER CLOUDS SHOULD MOVE EAST AND RETURNING SUNSHINE WILL ALLOW CUMULUS TO BUILD IN THEIR WAKE. ISOLD TO WIDELY SCATTERED SHRA AND PERHAPS A TSRA OR TWO HAS PROMPTED A VCSH MENTION AT KGSP/KGMU. A SECOND DISTURBANCE ARRIVING TONIGHT WILL BRING BETTER CHANCES TO MOST OF THE AREA...BUT STILL ONLY VCSH WORTHY AT BEST. SOME FOG IS EXPECTED IN MTN VALLEYS AND IN THE SAVANNAH RIVER VALLEY...TAKING KAVL/KAND DOWN TO MVFR IN THE EARLY MRNG. POPS DIMINISH AFTER DAYBREAK AS THE DISTURBANCE DEPARTS...BEFORE RAMPING UP AGAIN TOWARD MIDDAY WITH DIURNAL DESTABILIZATION. WINDS WILL REFLECT THE HIGH PRESSURE RIDGING DOWN THE EAST SIDE OF THE APPALACHIANS IN A REGIME SIMILAR TO A CAD WEDGE...MAINLY NE OVER THE PIEDMONT AND SE AT KAVL. OUTLOOK...DRY HIGH PRESSURE WILL MAINTAIN LOW POTENTIAL FOR MORNING RESTRICTIONS THROUGH THE WEEKEND. A RETURN TO A TYPICAL DIURNAL CYCLE OF CONVECTION MAY OCCUR EARLY NEXT WEEK AS A COLD FRONT ARRIVES FROM THE NORTHWEST. CONFIDENCE TABLE... 18-24Z 00-06Z 06-12Z 12-18Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 91% KAVL HIGH 99% HIGH 100% HIGH 80% HIGH 86% KHKY HIGH 100% HIGH 100% HIGH 82% MED 70% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 94% KAND HIGH 100% HIGH 100% HIGH 97% HIGH 97% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...LEV NEAR TERM...WIMBERLEY SHORT TERM...CDG LONG TERM...LEV AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
212 PM EDT FRI AUG 21 2015 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE NORTH...THOUGH MUCH DRYING IN THE WAKE OF THE FRONTAL PASSAGE IS UNLIKELY. ANOTHER COLD FRONT WILL CROSS THE REGION ON MONDAY...WITH A MUCH DRIER PERIOD STARTING ON TUESDAY. ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS WILL RETURN BY THE END OF NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... AS OF 200 PM...PATCHY MIDLEVEL CLOUDS REMAIN ACRS MUCH OF THE CWFA RESULTING FROM A WEAK VORT MAX DRIFTING ACRS THE AREA. THIS DECK APPEARS THINNER THAN IT DID LATE THIS MRNG...AND AS THE VORT MAX CONTINUES TO MOVE EAST IT SHOULD FOLLOW. A SHALLOW CU FIELD HAS QUICKLY BROKEN OUT AS SUNSHINE RETURNS...PARTICULARLY OVER THE MTNS OF SW NC AND NE GA...AND NOW THE UPPER SAVANNAH RIVER VALLEY. A COUPLE SHOWERS ARE ALSO SEEN ON RADAR TO OUR WEST. SHORT RANGE CAM GUIDANCE HAS GENERALLY OVERDONE THE STATE OF CONVECTION THIS MORNING POSSIBLY BECAUSE THEY UNDERESTIMATED THE RESTRICTED WARMING ASSOC WITH THE CLOUD COVER. THE HRRR HAS TRENDED TOWARD MORE ISOLATED COVERAGE. SEEING THE RATHER WEAK ACTIVITY UPSTREAM SUPPORTS MAINLY ISOLD RANGE POPS THIS AFTN. A SECOND VORT MAX OVER NRN ALABAMA WILL ARRIVE THIS EVENING...AND ENOUGH ELEVATED INSTABILITY AND LOW LEVEL MOISTURE WILL STILL BE PRESENT FOR ISOLATED CONVECTION TO OCCUR TONIGHT OVER MUCH OF THE AREA. MORE DETAILS TO COME IN DISCUSSION WITH AFTN PACKAGE DURING THE NEXT HOUR. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... AS OF 200 PM EDT FRIDAY...THE SHORT TERM FCST PERIOD INITIALIZES SATURDAY EVENING WITH THE UPPER PATTERN HIGHLIGHTED BY AN EASTERN GULF ANTICYCLONE...WHILE A SHORTWAVE TROF SLIDES THROUGH THE MIDSOUTH...WITH A DEEPER LONGWAVE TROF ADVECTING OVER THE UPPER MIDWEST. AT THE SFC...RELATIVELY DRIER NORTHERLY FLOW WILL PREVAIL OVER THE WESTERN CAROLINAS AND NORTHEAST GEORGIA CONSEQUENT OF ELONGATED HIGH PRESSURE MOVING EAST OF THE SOUTHERN/CENTRAL APPS. MODELS HINT AT ISOLATED/SCATTERED CONVECTION POSSIBLE AT FCST INITIALIZATION ACROSS THE AREA...HOWEVER MAINLY FOCUSED OVER THE NC/GA HIGH TERRAIN AND THE UPPER SAVANNAH RIVER VALLEY. EXPECTING THE UPPER SHORT WAVE TO ADVECT FURTHER EAST THROUGH THE NIGHT WARRANTING MENTIONABLE POPS THROUGH MORNING OVER THE WEST...SPREADING EAST AND INCREASING INTO THE AFTERNOON. THUS THE FCST FEATURES CHANCE POPS DURING THE DAY ON SUNDAY. MEANWHILE...A COLD FRONT WILL BE MOVING THROUGH THE MID MISSISSIPPI RIVER VALLEY INTO THE OHIO VALLEY BY EARLY MONDAY MORNING...ENTERING THE NC HIGH TERRAIN LATE AFTERNOON TO EARLY EVENING MONDAY. STILL SOME UNCERTAINTY AS TO HOW UNSTABLE THE AIRMASS WILL BE OUT AHEAD OF THE FRONT HOWEVER WITH THE LATEST THE NAM COMING IN MORE SO THAN PREVIOUS RUNS. THUS...WOULDNT BE SURPRISED TO SEE CONVECTION IN THE WARM SECTOR MONDAY AFTERNOON AHEAD/ALONG THE FRONT. FORTUNATELY...THE MOST ENHANCED UPPER WIND FIELD WILL BE WELL TO THE NORTH ALONG WITH THE PRIMARY UPPER LOW. THEREFORE SOUNDINGS FAVOR MORE OF A HAIL AND HYDRO THREAT AT THIS TIME...WITH EVEN THAT BEING ISOLATED. POPS ON MONDAY WILL FEATURE CHANCE LEVELS OVER THE HIGH TERRAIN TAPERING TO SLIGHT CHANCE LEVELS EAST ALONG THE I77 CORRIDOR. AS FOR HURRICANE DANNY...LATEST ADVISORY ISSUANCE FROM NHC INDICATES SOME WEAKENING THIS WEEKEND AS IT ENCOUNTERS DRIER AIR WITH THE CENTER OF CIRCULATION JUST OFF THE EAST COAST OF PUERTO RICO BY MONDAY AFTERNOON...LIKELY IN THE FORM OF A TROPICAL STORM. TEMPERATURES THROUGH THE PERIOD WILL SLOWLY MODERATE...WITH NEAR NORMAL HIGHS FCST ON SUNDAY AND HIGHS JUST ABOVE NORMAL ON MONDAY. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 200 PM FRIDAY...OVERALL MODEL AGREEMENT FOR THE MEDIUM RANGE IS ABOVE AVERAGE. THE UPPER PATTERN WILL CONTINUE TO AMPLIFY...WITH A SUBSTANTIAL RIDGE STILL IN PLACE OVER THE WESTERN CONUS AND A RAPIDLY DEEPENING TROUGH OVER THE EAST. AT THE SURFACE...THE APPROACHING FRONTAL BOUNDARY WILL MOVE THROUGH THE CWFA AT THE BEGINNING OF THE PERIOD. DESPITE THE FRONTAL PASSAGE COINCIDING WITH PEAK HEATING...DEEP NORTHWESTERLY FLOW WILL DRIVE SOME LEVEL OF DRYING BEFORE THE BOUNDARY ARRIVES. MODERATE INSTABILITY IS POSSIBLE IN THE HIGHER TERRAIN...BUT IS UNIMPRESSIVE ELSEWHERE. THOUGH THERE IS SOME QPF RESPONSE AS THE FRONT PASSES...A LACK OF DEEP MOISTURE AND LESS THAN THRILLING SHEAR PROFILES SHOULD KEEP CHANCES OF CONVECTION TO NO MORE THAN CHANCE OUTSIDE THE MOUNTAINS...AND HIGH-END CHANCE IN THE HIGHER TERRAIN. AN UNUSUALLY QUIET PERIOD...ESPECIALLY FOR THE END OF SUMMER...WILL ARRIVE AFTER THE FRONT CROSSES THE CWA. A SURFACE HIGH WILL BUILD IN FROM THE OHIO RIVER VALLEY...AND PWATS DROP TO WELL BELOW NORMAL. A NORTHERLY COMPONENT IS MAINTAINED IN THE SURFACE WINDS FOR ALMOST THE ENTIRE MEDIUM RANGE...SO KEEP A "SILENT 10" POP IN EACH AFTERNOON FOR THE MAJORITY OF THE AREA. SLIGHT CHANCE POPS WERE USED BORDERING COLUMBIA`S AREA...WITH ANY CHANCE AT CONVECTION FOLLOWING THE BETTER INSTABILITY. THE UPPER PATTERN WILL FLATTEN OUT BY THE END OF NEXT WEEK...AND THE INFLUENCE OF ATLANTIC HIGH PRESSURE WILL BUILD BACK IN. THIS INFLUENCE WILL BE REFLECTED IN A SLIGHT MOISTENING DUE TO AN INCREASED SOUTHERLY FLOW AT THE SURFACE. MAX AND MIN TEMPS WILL BE NEAR CLIMO THROUGH THE PERIOD. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AT KCLT...VFR. A PASSING UPPER DISTURBANCE THIS AFTERNOON WILL MAINTAIN A FAIR AMOUNT OF HIGH CLOUD COVER AND LIMIT DESTABILIZATION...SO EVEN THOUGH LOW VFR CU WILL DEVELOP THEY ARE UNLIKELY TO BECOME DEEP ENOUGH FOR ANY PRECIP TO RESULT. HIGH PRESSURE WILL CONTINUE TO BUILD DOWN THE EAST COAST REINFORCING NELY WINDS...THOUGH THEY ARE EXPECTED TO VEER SLIGHTLY SOUTH OF EAST FOR A TIME THIS EVENING. A SECOND DISTURBANCE ARRIVING TONIGHT WILL BRING ADDITIONAL CLOUD COVER AND A BETTER CHANCE FOR LIGHT SHOWERS...BOTH OF WHICH ARE EXPECTED TO CAUSE LITTLE IMPACT. WINDS WILL RETURN TO NE AFTER DAYBREAK. ELSEWHERE...IN THE WAKE OF ONE UPPER DISTURBANCE...HIGHER CLOUDS SHOULD MOVE EAST AND RETURNING SUNSHINE WILL ALLOW CUMULUS TO BUILD IN THEIR WAKE. ISOLD TO WIDELY SCATTERED SHRA AND PERHAPS A TSRA OR TWO HAS PROMPTED A VCSH MENTION AT KGSP/KGMU. A SECOND DISTURBANCE ARRIVING TONIGHT WILL BRING BETTER CHANCES TO MOST OF THE AREA...BUT STILL ONLY VCSH WORTHY AT BEST. SOME FOG IS EXPECTED IN MTN VALLEYS AND IN THE SAVANNAH RIVER VALLEY...TAKING KAVL/KAND DOWN TO MVFR IN THE EARLY MRNG. POPS DIMINISH AFTER DAYBREAK AS THE DISTURBANCE DEPARTS...BEFORE RAMPING UP AGAIN TOWARD MIDDAY WITH DIURNAL DESTABILIZATION. WINDS WILL REFLECT THE HIGH PRESSURE RIDGING DOWN THE EAST SIDE OF THE APPALACHIANS IN A REGIME SIMILAR TO A CAD WEDGE...MAINLY NE OVER THE PIEDMONT AND SE AT KAVL. OUTLOOK...DRY HIGH PRESSURE WILL MAINTAIN LOW POTENTIAL FOR MORNING RESTRICTIONS THROUGH THE WEEKEND. A RETURN TO A TYPICAL DIURNAL CYCLE OF CONVECTION MAY OCCUR EARLY NEXT WEEK AS A COLD FRONT ARRIVES FROM THE NORTHWEST. CONFIDENCE TABLE... 18-24Z 00-06Z 06-12Z 12-18Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 91% KAVL HIGH 99% HIGH 100% HIGH 80% HIGH 86% KHKY HIGH 100% HIGH 100% HIGH 82% MED 70% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 94% KAND HIGH 100% HIGH 100% HIGH 97% HIGH 97% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...LEV NEAR TERM...WIMBERLEY SHORT TERM...CDG LONG TERM...LEV AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
603 PM CDT FRI AUG 21 2015 .DISCUSSION...SEE 00Z AVIATION DISCUSSION. && .AVIATION...CONVECTION COMING TO AN END AND/OR MOVING OUT OF AREA. THINK KLRD WILL NOT SEE ANYTHING...BUT WILL MAKE ANY CHANGE IF NEEDED. THINK WITH MID/HIGH CLOUD COVER STILL EXPECTED...MVFR CIGS MAY BE HARD TO COME BY EXCEPT AT KVCT...WHERE MVFR CIGS COULD RESULT DUE TO SUSTAINED FLOW FROM THE GULF. OTHERWISE...WILL KEEP MVFR CIGS (TEMPO) IN KALI AND KLRD BEFORE 14Z (NEXT FORECASTER CAN DECIDE)...THEN SHOULD HAVE VFR. WITH TROUGH TO EAST AND WINDS KICKING UP...THINK CONVECTION WILL BE VERY LIMITED. WILL MENTION VCSH/VCTS FOR KVCT AND KCRP WHERE MOISTURE IS BETTER BUT NOTHING ANYWHERE ELSE (AND NO TEMPOS OR PROB30). SOUTH WINDS KICK UP ON SATURDAY AFTER 15Z...AND BECOME SSE IN THE AFTERNOON BEHIND THE SEA-BREEZE. && .PREV DISCUSSION... /ISSUED 329 PM CDT FRI AUG 21 2015/ SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...ATMOSPHERE HAS RECENTLY RECOVERED FROM CONVECTION EARLIER THIS MORNING. SHOWERS AND THUNDERSTORMS ARE NOW BEGINNING TO DEVELOP ALONG THE SEA BREEZE. A FEW OF THESE THUNDERSTORMS HAVE THE POTENTIAL TO BECOME STRONG AS MLCAPES ARE AOA 2000 J/KG PER SPC MESOANALYSIS PAGE. GUSTY WINDS AND LOCALLY HEAVY DOWNPOURS WOULD BE THE MAIN IMPACTS FROM THESE STORMS. MOST OF THIS ACTIVITY SHOULD BE DIURNALLY DRIVEN AND LATEST RUN OF THE HRRR SUPPORTS THIS. WILL ONLY CARRY 20 POPS AFTER 00Z. AS WITH THE LAST COUPLE OF MORNINGS... CONVECTION MAY REDEVELOP OVER THE GULF WATERS LATE TONIGHT INTO EARLY SATURDAY MORNING. SHOWERS AND STORMS WILL THEN MOVE INLAND WITH SEA BREEZE DURING THE AFTERNOON...WHICH IS HANDLED WELL IN THE CURRENT FORECAST. TEMPERATURES WILL REBOUND ON SATURDAY WITH HIGHS NEAR 100 OVER THE RIO GRANDE PLAINS TO LOWER/MIDDLE 90S ACROSS THE COASTAL BEND. OVERNIGHT LOWS WILL CONTINUE TO BE ON THE WARM SIDE...WITH TEMPS IN THE MID/UPPER 70S AND LOWER 80S ALONG THE IMMEDIATE COAST. LONG TERM (SUNDAY THROUGH FRIDAY)...MID LEVEL HIGH PRESSURE ACROSS THE DESERT SOUTHWEST AND ACROSS THE GULF BEGIN TO MERGE TOGETHER ACROSS THE SOUTHERN PLAINS SUNDAY...ALLOWING FOR RIDGING TO BUILD ACROSS SOUTH TEXAS. REMNANTS OF THE EARLIER TROUGH LIFT TO THE NORTH AND EAST...BUT SEND OUT AN IMPULSE OF ENERGY SOUTHWARD MONDAY. AT THE SURFACE...LOW PRESSURE ACROSS THE HIGH PLAINS SWINGS EAST PUSHING A COLD FRONT THROUGH THE CENTRAL PLAINS AND GREAT LAKES REGION. ALTHOUGH THE MAIN FRONT IS NOT EXPECTED TO MOVE THROUGH SOUTH TEXAS...WITH THE MID LEVEL IMPULSE WILL AIDING IN FURTHER SOUTHEASTWARD PROGRESSION OF THE FRONT...AND HIGH PRESSURE WILL BEGIN TO BUILD INTO THE SOUTHERN STATES. MOISTURE POOLING ALONG THE SOUTHERN PERIPHERY OF THE HIGH WITH PWATS NEAR 1.9 INCHES...WILL BRING RAIN CHANCES TUESDAY AND WEDNESDAY. THIS BOUNDARY WILL ALLOW FOR WINDS TO BECOME LIGHT AND VARIABLE BY TUESDAY...WITH THE COASTAL PLAINS WINDS MORE INFLUENCED ON DIURNAL THERMAL DIFFERENCES...WITH A LIGHT LAND BREEZE OVERNIGHT SWITCHING OUT OF THE EAST TO SOUTHEAST IN THE AFTERNOON DUE TO THE SEA BREEZE. A MORE PERSISTENT SOUTHEASTERLY FLOW WILL REDEVELOP HEADING INTO THURSDAY NIGHT. NOTICEABLE DIURNAL FLUCTUATIONS WITH TEMPERATURES ARE ALSO EXPECTED...ESPECIALLY AFTER WEDNESDAY...AS THE DRIER AIR AND CLEARER SKIES SHOULD CONTINUE TO ALLOW DAYTIME TEMPS TO REACH INTO THE MID TO UPPER 90S AND ALSO RESULT IN OVERNIGHT LOWS DIPPING INTO THE LOWER 70S. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 79 93 79 94 76 / 20 20 10 20 10 VICTORIA 76 94 76 96 75 / 20 30 10 20 10 LAREDO 78 100 78 101 77 / 20 20 10 10 10 ALICE 76 96 76 96 75 / 20 30 10 20 10 ROCKPORT 80 91 81 91 79 / 20 20 10 20 10 COTULLA 77 99 77 100 76 / 20 20 10 10 10 KINGSVILLE 78 95 78 96 76 / 20 20 10 20 10 NAVY CORPUS 80 89 81 91 80 / 20 20 10 20 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ GW/86...SHORT TERM GW/86...LONG TERM
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
335 PM CDT FRI AUG 21 2015 .SHORT TERM... (Tonight and Saturday) Skies were mostly sunny across West Central Texas this afternoon with south winds of 10 to 15 mph. The conditions were humid with dewpoints in the 60s at 19Z. Temperatures across the area were in the lower to mid 90s. Keeping an eye on a vort max (per WV imagery) over southeast Colorado, with subtle trough axis extending south into west Texas. The combination of mid and upper ascent from the upper level feature, moderate instability and a surface trough will lead to scattered thunderstorms developing across the Texas Panhandle and South Plains late this afternoon and evening. All of the convective allowing models (TX Tech WRF, HRRR and 4km NMM) indicate scattered cells merging into a few small convective complexes and moving east-southeast toward western Oklahoma and northwest Texas this evening into the early morning hours. The Big Country has the best chance of seeing thunderstorms tonight, mainly after 02Z. A few storms may produce strong wind gusts along with dangerous lightning. Going with slight chance to chance Pops generally north of Sterling City to Brownwood line for tonight, with the highest numbers north of the I-20 corridor. Lows will be 70 to 75. For Saturday, going with a dry and hot forecast as low level southerly flow will persist. Highs will be 95 to 100. There will be widespread low clouds across much of the area during the morning, mostly dissipating by 17Z. 21 .LONG TERM... (Saturday night through Friday) Generally quiet weather conditions are anticipated Saturday night. The low-level jet will intensify by mid-evening, keeping southerly winds up at 10-15 mph overnight. This will help maintain a moist boundary layer and keep overnight lows in the mid 70s. We may also see low stratus develop over the Hill Country, but its northward extent should remain limited. A cold front will move south across the South Plains early Sunday and is expected to move into the Big Country during the afternoon hours. Temperatures across the Big Country will depend on how fast (and how far south) the front advances on Sunday afternoon, but for now it appears that highs will be in the mid to upper 90s across most of the area. There is a chance for showers and thunderstorms, mainly along and north of the front (across the Big Country), Sunday afternoon. This boundary is forecast to move slowly south Sunday night and early Monday, eventually stalling between I-10 and I-20. Again, the best rain chances will be focused along and north of the front. However, with an east-northeast steering flow, slight chance PoPs were warranted farther south and west of the boundary, covering most of the CWA. Temperatures should be a few degrees cooler on Monday, and may need to be lowered a few degrees further. Rain chances will continue areawide on Tuesday as the quasi- stationary front persists over the CWA. Temperatures should again be in the vicinity of climatology with lows in the low/mid 70s and highs in the mid 90s. By midweek, the subtropical ridge is expected to become the dominate synoptic feature over the High Plains. This should result in dry conditions Wednesday and Thursday, with temperatures likely moving back into the mid/upper 90s. Both the ECMWF and GFS indicate a fairly potent shortwave moving southeast into the Southern Plains Thursday night into Friday. This could result in additional rain chances, but the forecast was left dry for now. Will continue to watch how this feature is handled by subsequent model runs. Johnson && .PRELIMINARY POINT TEMPS/POPS... Abilene 73 98 75 96 / 20 5 5 20 San Angelo 73 100 75 99 / 10 5 0 10 Junction 73 97 75 98 / 10 5 0 5 && .SJT WATCHES/WARNINGS/ADVISORIES... None. && $$ 21/25
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
329 PM CDT FRI AUG 21 2015 .SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...ATMOSPHERE HAS RECENTLY RECOVERED FROM CONVECTION EARLIER THIS MORNING. SHOWERS AND THUNDERSTORMS ARE NOW BEGINNING TO DEVELOP ALONG THE SEA BREEZE. A FEW OF THESE THUNDERSTORMS HAVE THE POTENTIAL TO BECOME STRONG AS MLCAPES ARE AOA 2000 J/KG PER SPC MESOANALYSIS PAGE. GUSTY WINDS AND LOCALLY HEAVY DOWNPOURS WOULD BE THE MAIN IMPACTS FROM THESE STORMS. MOST OF THIS ACTIVITY SHOULD BE DIURNALLY DRIVEN AND LATEST RUN OF THE HRRR SUPPORTS THIS. WILL ONLY CARRY 20 POPS AFTER 00Z. AS WITH THE LAST COUPLE OF MORNINGS... CONVECTION MAY REDEVELOP OVER THE GULF WATERS LATE TONIGHT INTO EARLY SATURDAY MORNING. SHOWERS AND STORMS WILL THEN MOVE INLAND WITH SEA BREEZE DURING THE AFTERNOON...WHICH IS HANDLED WELL IN THE CURRENT FORECAST. TEMPERATURES WILL REBOUND ON SATURDAY WITH HIGHS NEAR 100 OVER THE RIO GRANDE PLAINS TO LOWER/MIDDLE 90S ACROSS THE COASTAL BEND. OVERNIGHT LOWS WILL CONTINUE TO BE ON THE WARM SIDE...WITH TEMPS IN THE MID/UPPER 70S AND LOWER 80S ALONG THE IMMEDIATE COAST. && .LONG TERM (SUNDAY THROUGH FRIDAY)...MID LEVEL HIGH PRESSURE ACROSS THE DESERT SOUTHWEST AND ACROSS THE GULF BEGIN TO MERGE TOGETHER ACROSS THE SOUTHERN PLAINS SUNDAY...ALLOWING FOR RIDGING TO BUILD ACROSS SOUTH TEXAS. REMNANTS OF THE EARLIER TROUGH LIFT TO THE NORTH AND EAST...BUT SEND OUT AN IMPULSE OF ENERGY SOUTHWARD MONDAY. AT THE SURFACE...LOW PRESSURE ACROSS THE HIGH PLAINS SWINGS EAST PUSHING A COLD FRONT THROUGH THE CENTRAL PLAINS AND GREAT LAKES REGION. ALTHOUGH THE MAIN FRONT IS NOT EXPECTED TO MOVE THROUGH SOUTH TEXAS...WITH THE MID LEVEL IMPULSE WILL AIDING IN FURTHER SOUTHEASTWARD PROGRESSION OF THE FRONT...AND HIGH PRESSURE WILL BEGIN TO BUILD INTO THE SOUTHERN STATES. MOISTURE POOLING ALONG THE SOUTHERN PERIPHERY OF THE HIGH WITH PWATS NEAR 1.9 INCHES...WILL BRING RAIN CHANCES TUESDAY AND WEDNESDAY. THIS BOUNDARY WILL ALLOW FOR WINDS TO BECOME LIGHT AND VARIABLE BY TUESDAY...WITH THE COASTAL PLAINS WINDS MORE INFLUENCED ON DIURNAL THERMAL DIFFERENCES...WITH A LIGHT LAND BREEZE OVERNIGHT SWITCHING OUT OF THE EAST TO SOUTHEAST IN THE AFTERNOON DUE TO THE SEA BREEZE. A MORE PERSISTENT SOUTHEASTERLY FLOW WILL REDEVELOP HEADING INTO THURSDAY NIGHT. NOTICEABLE DIURNAL FLUCTUATIONS WITH TEMPERATURES ARE ALSO EXPECTED...ESPECIALLY AFTER WEDNESDAY...AS THE DRIER AIR AND CLEARER SKIES SHOULD CONTINUE TO ALLOW DAYTIME TEMPS TO REACH INTO THE MID TO UPPER 90S AND ALSO RESULT IN OVERNIGHT LOWS DIPPING INTO THE LOWER 70S. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 79 93 79 94 76 / 20 20 10 20 10 VICTORIA 76 94 76 96 75 / 20 30 10 20 10 LAREDO 78 100 78 101 77 / 20 20 10 10 10 ALICE 76 96 76 96 75 / 20 30 10 20 10 ROCKPORT 80 91 81 91 79 / 20 20 10 20 10 COTULLA 77 99 77 100 76 / 20 20 10 10 10 KINGSVILLE 78 95 78 96 76 / 20 20 10 20 10 NAVY CORPUS 80 89 81 91 80 / 20 20 10 20 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ TB/78...SHORT TERM CB/85...LONG TERM
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
319 PM CDT FRI AUG 21 2015 .SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...UPPER LEVEL TROUGH REMAINS OVER THE AREA PUMPING IN HIGH LEVELS OF MOISTURE INTO THE AREA. IN FACT...12Z BRO SOUNDING SHOWED PWATS OF 2.3 INCHES. EARLY MORNING MID/HIGH CLOUDS STUNTED DIURNAL TEMPERATURE RISE IN THE MID/LOWER VALLEY SO ADJUSTED HOURLY TEMPERATURE GRIDS DOWN AND SHAVED A DEGREE OF THE HIGHS. STILL EXPECT 90S TODAY WITH UPPER 90S OUT IN OUR WESTERN SECTIONS. CUMULUS FIELD IS SLOW TO DEVELOP AND IS NOW BECOMING AGITATED ACROSS THE RANCHLANDS OF BROOKS AND EASTERN JIM HOGG COUNTIES. IN THE VALLEY...JUST NOW BEGINNING TO SEE CUMULUS DEVELOPMENT UNDERNEATH REMAINING MID/HIGH CLOUD DECKS. MOS GUIDANCE HAS LOWERED POPS IN THE VALLEY AND HAVE FOLLOWED SUIT AND HAVE LEFT INHERITED POPS AS IS FOR THIS AFTERNOON. HRRR SHOWS DEVELOPMENT IMMINENT IN THE RANCHLANDS WITH SHOWERS/STORMS MOVING WESTWARD WITH TIME INTO OUR WESTERN SECTIONS EARLY THIS EVENING BEFORE DISSIPATING BY MID EVENING. OVERNIGHT CONVECTION WILL DEVELOP OVER THE COASTAL WATERS BUT SHOULD NOT BE AS WIDESPREAD AS LAST NIGHT. LOW/MID CLOUDS EXPECTED TO DEVELOP OVERNIGHT WITH MOSTLY CLOUDY SKIES BY DAYBREAK HOLDING UP LOW TEMPERATURES CLOSER TO 80 DEGREES IN THE VALLEY. UPPER TROUGH WEAKENS SATURDAY AND BEING REPLACED BY EXPANDING UPPER LEVEL RIDGING AND LOWER PWATS LEADING TO LOWER CHANCES FOR PRECIPITATION SATURDAY AND SATURDAY NIGHT. TIME HEIGHTS AND CROSS SECTIONS DEPICT MAINLY LOW LEVEL MOISTURE WITH A DRYING MID LEVEL COLUMN. THERE IS A CHANCE FOR A FEW SHOWERS SATURDAY BUT SHOULD REMAIN ISOLATED. THERE WILL AN UPTICK IN THE WINDS WITH SFC HIGH PRESSURE IN THE NORTHERN GULF AND LOW PRESSURE ACROSS THE HIGH PLAINS. HIGH TEMPERATURES WILL BE WARMER AS WELL WITH HIGHS AROUND 100 IN THE FAR WEST TO MID 90S IN THE LOWER VALLEY. .LONG TERM /SUNDAY THROUGH FRIDAY/...THE 500 MB RIDGING WILL BUILD OVER THE REGION THROUGHOUT NEXT WEEK AS TROFFING BUILDS OVER THE EASTERN STATES. THE GFS PRODUCES A DRIER SOLUTION VERSUS THE ECMWF WITH THE EURO MODEL BRINGING A PRETTY STRONG 500 MB VORT MAX AROUND THE EAST SIDE OF THE RIDGE WHICH CRANKS OUT MUCH HIGHER POPS FOR THE RGV AROUND MIDWEEK. THE GFS HAS BEEN CONSISTENTLY DRY OVER THE LAST SEVERAL RUNS SO AM A LITTLE SCEPTICAL OF THE WETTER ECMWF SOLUTION AT THIS TIME. WILL SEE IF FUTURE RUNS OF THE ECMWF MAINTAIN THE WET BIAS BEFORE JUMPING TO HIGHER POPS IN THE LONGER RANGE. SO WILL GO WITH SLGT CHC POPS AT THIS TIME. SINCE CONFIDENCE LEVEL IN THE LONGER RANGE NUMERICAL GUIDANCE IS A BIT LOWER TODAY WILL OPT FOR A GENERAL BLEND OF THE GFS MEX MOS TEMPS AND THE ECMWF TEMPS. && .MARINE...NOW THROUGH SATURDAY NIGHT...SEAS WERE NEAR 3 FEET WITH SOUTHEAST WINDS NEAR 14 KNOTS AT BUOY020 THIS AFTERNOON. MODERATE SOUTHEAST WINDS WILL PREVAIL ACROSS THE COASTAL WATERS AS HIGH PRESSURE ACROSS THE NORTHERN GULF OF MEXICO AND LOW PRESSURE ACROSS WEST TEXAS WILL KEEP A STEADY SOUTHEAST WIND GOING ACROSS THE COASTAL WATERS. WINDS AND SEAS WILL BE HIGHER IN AND AROUND AND SHOWERS AND STORMS. SUNDAY THROUGH WEDNESDAY...A STATIONARY FRONT WILL DRIFT SOUTH OVER THE GULF COAST AND THE NORTHERN GULF OF MEXICO THROUGHOUT EARLY NEXT WEEK. AS THIS FRONT SAGS SOUTHWARDS THE PGF WILL WEAKEN SOMEWHAT ALLOWING FOR FAIRLY LOW WINDS AND SEAS TO PREVAIL ACROSS THE BAY AND GULF WATERS. NO SCA CONDITIONS EXPECTED THROUGH WEDNESDAY. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 80 94 80 92 / 20 20 10 10 BROWNSVILLE 79 94 79 93 / 20 20 10 10 HARLINGEN 79 97 79 96 / 20 20 10 10 MCALLEN 79 98 80 99 / 20 20 10 10 RIO GRANDE CITY 78 99 78 100 / 30 20 10 10 SOUTH PADRE ISLAND 81 88 81 87 / 20 20 10 20 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV SHORT TERM...55 LONG TERM...60
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1237 PM CDT FRI AUG 21 2015 .AVIATION... AFTER SPENDING MUCH OF THE MORNING IN IFR CONDITIONS ACROSS THE I-35 CORRIDOR AND MVFR CONDITIONS AT DRT CLOUDS ARE BEGINNING TO BREAK. AS OF A FEW MOMENTS AGO MVFR CONDITIONS NOW PREVAIL AT ALL 4 TERMINALS. THESE CIGS SHOULD STICK AROUND FOR ANOTHER HOUR OR TWO BUT CLOUDS ARE THINNING FROM WEST TO EAST SO VFR CONDITIONS SHOULD BREAK OUT AT ALL TERMINALS BY 20Z. MORNING RAINFALL HAS MOVED NORTH OF AUS AND PRECIPITATION TO THE SOUTH OF AUS AND EAST OF SAT SHOWS SIGNS OF WEAKENING. WILL NOT CARRY ANY MENTION OF PRECIPITATION IN THE AFTERNOON TAFS AS CHANCES WILL BE DECREASING THROUGH THE DAY. WINDS WILL BE SOUTHEASTERLY THROUGH THE TAF PERIOD. WITH THE SUN HELPING TO MIX OUT SOME MOISTURE THIS AFTERNOON SHOULD NOT SEE A REPEAT OF THIS MORNINGS CIGS. WILL SEE MORNING MVFR STRATUS THOUGH BEGINNING AROUND 09Z AND BREAKING AROUND 17Z SATURDAY MORNING AT THE I-35 TERMINALS. DRT MAY SEE SOME HIGH END MVFR STRATUS AS WELL. && .PREV DISCUSSION... /ISSUED 935 AM CDT FRI AUG 21 2015/ UPDATE... EARLY MORNING SHOWERS AND THUNDERSTORMS OVER THE COASTAL AREAS HAS SENT AN OUTFLOW THAT GENERATED SHOWERS AND THUNDERSTORMS OVER THE EASTERN PARTS OF SOUTH CENTRAL TEXAS. HAVE BOOSTED POPS 10 TO 20 PERCENT ACROSS AREAS EAST OF I-35 TO ACROSS THE AUSTIN AREA INTO THE NORTHEASTERN HILL COUNTRY. DUE TO CLOUDS AND RAIN LINGERING INTO THE AFTERNOON DUE TO BEING ON THE EASTERN SIDE OF THE MID TO UPPER LEVEL SHEAR AXIS...HAVE ALSO LOWERED TEMPERATURES SLIGHTLY. REMAINDER OF SOUTH CENTRAL TEXAS FORECAST IS ON TRACK. PREV DISCUSSION... /ISSUED 650 AM CDT FRI AUG 21 2015/ AVIATION.../12Z TAF CYCLE/ LOWER CIGS HAVE FILLED IN AS EXPECTED THIS MORNING WITH WIDESPREAD MVFR WITH INTERMINGLED IFR CONDITIONS PRESENT ACROSS CENTRAL TAF SITES WITH KDRT MVFR AS WELL. AMPLE MOISTURE IN THE LOWER LAYERS WILL TAKE SOME TIME TO MIX OUT THROUGH 15-17Z WITH A GRADUAL IMPROVEMENT THROUGH MVFR TO EVENTUAL VFR FALL ALL SITES BY LATE MORNING TO EARLY AFTERNOON. A COMPLEX OF SHOWERS AND STORMS IS MOVING INLAND NEAR KVCT BUT WILL LIKELY MISS THE CENTRAL SITES. FEEL MOST SCATTERED ACTIVITY WILL REMAIN SOUTHEAST OF THE MAIN TERMINALS AND HAVE REFRAINED FROM VCTS WORDING THIS TAF CYCLE. TRENDS WILL NEED TO BE MONITORED HOWEVER FOR POSSIBLE INCLUSION ON 18Z CYCLE. SURFACE WINDS ARE LIGHT AND VARIABLE CURRENTLY BUT WILL PICK UP TO 10-15 KT THIS AFTN FROM THE SOUTHEAST TO SOUTH DIRECTION. PREV DISCUSSION... /ISSUED 333 AM CDT FRI AUG 21 2015/ SHORT TERM (TODAY THROUGH SATURDAY)... A N-S ORIENTED SHEAR AXIS MOST NOTABLE IN THE MID LEVELS OVER S TX AND ADJACENT AREAS OF NERN MEXICO SHOULD BRING ANOTHER DAY OF CONVECTION AND MODERATED DAYTIME TEMPERATURES FOR THE EASTERN HALF OF SOUTH CENTRAL TX. WHILE THE FRONTAL ZONE THAT BROUGHT WELL BELOW NORMAL MAX TEMPS TO THE AREA THURSDAY HAS RETREATED NORTH...SOME COASTAL TROUGHING IS STILL NOTED NEAR CRP...AND A SMALL COMPLEX OF STORMS CONFIRMS THE UNSTABLE ENVIRONMENT THAT COULD SPREAD INLAND LATER THIS MORNING. RAPID REFRESH MODEL RUNS DEPICT EARLY DESTABILIZATION NEAR AND EAST OF I-35 TODAY...BUT EARLIER RUNS OF THE HRRR WERE SHOWN TO BE TOO AGGRESSIVE WITH CONVECTION IN THE PRE-DAWN HOURS. ADDITIONAL MOISTURE AND POSSIBLE INSTABILITY IS MOVING IN FROM NW FLOW ALOFT FROM WEST TX...BUT WITH ONLY THE 00Z NSSL WRF MODEL SHOWING AN IMPACT OVER OUR WESTERN COUNTIES VERSUS SEVERAL THAT DO NOT...WILL STICK WITH THE CONSENSUS POPS FOR THE SERN TWO-THIRDS OF THE FORECAST AREA. BLENDED GUIDANCES CONTAIN ARTIFACTS OF EARLIER FORECAST HIGHER TEMPS...SO OPTED FOR A BLEND OF MAV/MET FOR HIGHS. MODEL RUN TO RUN TRENDS IN THE EARLY PERIODS SHOW MORE SHEAR THAN EARLIER RUNS...SO WILL FOLLOW THIS TREND TO KEEP A SLIGHTLY LESS STABLE PICTURE FOR OUR SOUTHERN/WRN COUNTIES FOR SATURDAY. INCREASED RIDGING AND DRY AIR ENTRAINMENT FROM THE NORTH SHOULD PRECLUDE CONVECTION OVER MOST OF SOUTH CENTRAL TEXAS...BUT THE WESTWARD SHIFTING SHEAR AXIS SHOULD PULL SOME MOISTURE WITH IT TO BRING A SLIGHT CHANCE OF DAYTIME CONVECTION OVER THE RIO GRANDE PLAINS. MEANWHILE SOUTHERN PARTS OF THE COASTAL PLAINS LOSE THE CYCLONIC SHEAR BUT MAINTAIN LOCALLY HIGHER PWAT VALUES FOR ONE MORE DAY. WILL FAVOR THE GFS BASED GUIDANCE FOR WARMER TEMPS TO REGAIN CONTROL OVER CENTRAL TX WHERE THE DRIER AND MORE STABLE MID- LEVEL AIR MOVES IN. LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)... THE BRIEF BREAK FROM THE HEAT IS ALL BUT FORGOTTEN BY SUNDAY. THE GFS AND ECMWF BOTH BUILD A STRONG RIDGE OVER THE SOUTHERN ROCKIES WITH AN AXIS THAT EXTENDS SE ACROSS CENTRAL TX. WILL SHADE TOWARD THE HIGHER MEX GUIDANCE ON MAXES SUNDAY THROUGH WEDNESDAY AS AUGUST RAINS HAVE BEEN MOSTLY TOO SPARSE TO PROVIDE FEEDBACK THROUGH SOIL AND VEGETATION. LATE MONDAY THROUGH DAYTIME WEDNESDAY...THERE IS A SIGNAL FOR MID-LEVEL MOISTURE POOLING TO SPREAD SOUTH FROM NORTH TX AS NORTHERLY FLOW INCREASES ALOFT. THUS WILL SHADE TOWARD THE SLIGHTLY MORE UNSTABLE ECMWF OVER THE SLIGHTLY DRIER GFS FOR THOSE DAYS. LITTLE OR NO CONVECTION IS SHOWN BY EITHER MODEL FOR THE REMAINDER OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 91 76 98 77 99 / 40 10 10 - - AUSTIN BERGSTROM INTL AIRPORT 92 73 97 75 98 / 40 10 10 - - NEW BRAUNFELS MUNI AIRPORT 92 75 98 76 98 / 30 10 10 - - BURNET MUNI AIRPORT 92 74 97 75 98 / 20 10 10 - - DEL RIO INTL AIRPORT 96 76 98 78 99 / 10 - 20 - - GEORGETOWN MUNI AIRPORT 92 76 96 76 98 / 40 10 10 - 10 HONDO MUNI AIRPORT 95 74 96 75 97 / 20 10 10 - - SAN MARCOS MUNI AIRPORT 92 75 98 76 99 / 30 10 10 - - LA GRANGE - FAYETTE REGIONAL 91 76 96 76 98 / 50 20 20 10 10 SAN ANTONIO INTL AIRPORT 93 76 97 77 98 / 30 10 10 - - STINSON MUNI AIRPORT 93 76 98 77 99 / 30 20 10 - - && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...TREADWAY SYNOPTIC/GRIDS...04 PUBLIC SERVICE/DATA COLLECTION...10
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1236 PM CDT FRI AUG 21 2015 .DISCUSSION...UPDATED FOR 18Z AVIATION. && .AVIATION...LATEST RUN OF THE HRRR RE-DEVELOPS SHOWERS AND THUNDERSTORMS ACROSS SOUTH TEXAS THIS AFTERNOON. WILL HANDLE THE POTENTIAL FOR CONVECTION WITH VCTS REMARKS FOR NOW AND WILL AMEND AS NECESSARY. VFR CONDITIONS INITIALLY WILL THEN TRANSITION TO MVFR LEVELS OVERNIGHT INTO EARLY SATURDAY MORNING. LOW CLOUDS SHOULD MIX OUT AROUND 14Z/15Z WITH A RETURN TO VFR CONDITIONS. && .PREV DISCUSSION... /ISSUED 905 AM CDT FRI AUG 21 2015/ DISCUSSION...INCREASED POPS ACROSS THE MIDDLE TEXAS COASTAL WATERS AND IMMEDIATE COASTAL COUNTIES BASED ON LATEST RADAR TRENDS. PREV DISCUSSION... /ISSUED 645 AM CDT FRI AUG 21 2015/ DISCUSSION...NOTE AVIATION DISCUSSION BELOW. AVIATION...A MIXTURE OF VFR/MVFR CEILINGS WL PERSIST THIS MORNING DRG AND OUTSIDE OF ISOLATED/SCATTERED SHOWERS OVER THE COASTAL BEND/OFFSHORE. CONTINUE TO ANTICIPATE THE DEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS DRG THE LATE MORNING/AFTERNOON OVER LAND MAINLY EAST OF U.S. ROUTE 281. EXPECT CONVECTION TO THEN MOVE GENERALLY WEST OF U.S. ROUTE 281 DRG THE EVENING. NOCTURNAL CONVECTION EXPECTED AGAIN OVERNIGHT NEAR THE COAST/OFFSHORE. GENERALLY LGT/VARIABLE WIND EARLY THIS MORNING TRANSITIONING TO MODERATE ONSHORE FLOW DRG THE MID/LATE AFTN HOURS TODAY. BECOMING LGT AGAIN OVERNIGHT. PREV DISCUSSION... /ISSUED 601 AM CDT FRI AUG 21 2015/ SHORT TERM (TODAY THROUGH SATURDAY)...CONVECTION EARLY THIS MORNING OVER THE MSA/ERN CWA NEAR A SFC TROUGH. GFS/NAM STREAMLINES DEPICT AN UPPER TROUGH AXIS OVER THE ERN CWA. GOES SOUNDER DPI PWAT SUGGEST COPIOUS MSTR OVER THE CWA/MSA. NAM PREDICTS SIGNIFICANT CAPE/LOW CIN THIS AFTN. EXPECT THE COMBINATION OF THE UPPER SYSTEM/MSTR/INSTABILITY/SEA BREEZE TO RESULT IN SCATTERED CONVECTION TODAY. EXPECT CONVECTION TO SHIFT TO THE WRN CWA DRG THE EVENING. CONCUR WITH THE GFS/NAM WHICH MAINTAINS THE UPPER PATTERN TONIGHT/SATURDAY. THUS EXPECT NOCTURAL CONVECTION TO DEVELOP AGAIN OVER THE MSA OVERNIGHT/EARLY SATURDAY FOLLOWED BY AFTN CONVECTION OVER THE CWA. LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...THE UPPER LEVEL TROUGH AXIS IS PROGD TO SHIFT FARTHER W SAT NIGHT/SUN WITH HIGH PRESSURE BUILDING ACROSS S TX FROM THE NE AND E. THIS WILL BRING DRIER AIR TO S TX...BUT STILL SUFFICIENT MOISTURE FOR ISOLD SEA BREEZE CONVECTION SUN AFTERNOON. THE HIGH PRESSURE ALOFT IS PROGD TO REMAIN IN CONTROL THROUGH THE REMAINDER OF NEXT WEEK WITH ONLY ISOLD CONVECTION EXPECTED ON TUE ACROSS THE NE AND E CWA DUE TO A WEAK SHORT WAVE ROUNDING THE SE PERIPHERY OF THE RIDGE. OTHERWISE...GENERALLY DRY FCST FOR THE EXTENDED. TEMPS ARE EXPECTED TO BE NEAR NORMAL NEXT WEEK ALONG WITH A WEAK TO OCCASIONALLY MOD ONSHORE FLOW. MODELS DO SHOW VERY LIGHT OFFSHORE WINDS EACH NIGHT/EARLY MORNING THROUGH MUCH OF NEXT WEEK WHICH WILL HELP KEEP MN TEMPS A TAD COOLER THAN THIS PAST WEEK. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 78 93 79 94 78 / 20 20 10 20 10 VICTORIA 76 94 76 95 76 / 20 30 10 20 10 LAREDO 78 99 78 101 77 / 20 20 10 10 10 ALICE 76 96 77 96 76 / 20 30 10 20 10 ROCKPORT 80 90 81 91 80 / 20 20 10 20 10 COTULLA 75 98 76 100 76 / 20 20 10 10 10 KINGSVILLE 77 95 78 95 77 / 20 20 10 20 10 NAVY CORPUS 80 89 81 90 80 / 20 20 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ TB/78...AVIATION
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1242 PM CDT FRI AUG 21 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 318 AM CDT FRI AUG 21 2015 MOST OF THE FORECAST TIME THIS MORNING WAS ENSURING WE WERE ON TRACK WITH RAIN CHANCES IN THE RETURN FLOW TODAY....CLOUDS ON SATURDAY...BUT MAINLY THE SATURDAY NIGHT THUNDERSTORM THREATS AND ANY MESSAGING THAT WILL BE NEEDED FOR THOSE OUTDOORS. CURRENT OBSERVATIONAL DATA AS OF 21.07Z INDICATES NW-SE ORIENTED CLOUD BANDING AROUND 10KFT ACROSS CENTRAL MN ASSOCIATED WITH FRONTOGENESIS IN THE 800-900 MB LAYER PER LATEST RAP ANALYSIS. TSRA AND LIGHTNING IN NWRN IA ON THE NOSE OF THE LOW-LEVEL JET PER 88D VWPS AND RAP ANALYSIS. SPC MESOANALYSIS SHOWING THAT TSRA IS ON THE NORTHERN EXTENT OF THE MUCAPE REGION /ONLY ABOUT 250 J/KG THERE/. GOES FOG PRODUCT AND SURFACE OBSERVATIONS SHOW A LOWER CLOUD FIELD OVER OK/TX SOUTH IN A RICH MOIST POOL OF SURFACE DEWPOINTS OVER 65F...AND 925MB DEWPOINTS AT 18C PER 21.00Z RAOBS. WILL HAVE TO WATCH THIS AREA AS IT ADVECTS NORTHWARD AHEAD OF THE FRONT THAT IS MOVING IN FOR SATURDAY NIGHT...ASSOCIATED WITH THE SHORTWAVE TROUGH NOW WORKING SOUTHWARD THROUGH BRITISH COLUMBIA /PER GOES WATER VAPOR/. RAP ANALYSIS INDICATES THIS SPINNER HAS A TROPOPAUSE FOLD DOWN TO ROUGHLY 750 MB...SO A POTENT VORTEX. SHORT TERM GUIDANCE SUPPORTS EVOLVING THE FRONTOGENESIS AND THE LOW-LEVEL JET NOSE CONVERGENCE NORTHEAST THROUGH THE FIRST PORTION OF TODAY INTO NRN WI BY AFTERNOON. THERE WILL LIKELY BE VERY LIGHT RADAR RETURNS AND PER 00Z RAOB DATA...SOME PRETTY DRY AIR TO OVERCOME BELOW THE ACCAS CLOUD BASE /10KFT/. FOR NOW...HAVE KEPT THE HIGHER PROBABILITY DRY FORECAST. SPRINKLES OR AN ISOLATED WETTING SHOWER MAY BE POSSIBLE WITH FORCING EVOLUTION NEWRD. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 318 AM CDT FRI AUG 21 2015 NO BIG CHANGES DURING THIS PERIOD. SOUTHWESTERLY FLOW WILL PREVAIL SATURDAY AND PRE-FRONTALLY WILL NEED TO WATCH THE SURGE OF 925 MB MOISTURE NORTHWARD TONIGHT. CONSENSUS 21.00Z GUIDANCE SUGGESTS THIS TONGUE REMAINS WEST OF THE AREA UNTIL FRONT ARRIVES SAT EVENING. HAVE INCREASED WIND GUSTS SATURDAY WITH STRONGER LOW-LEVEL WIND FIELD SUGGESTED AND MIXING DEPTH INTO THE 35-38KT CONSENSUS 900MB WINDS. TIMING IS ABOUT THE SAME AS PREVIOUS FORECASTS FOR FRONT TO BECOME ACTIVE TO THE WEST OF THE AREA LATER SATURDAY. THIS FRONT IS ASSOCIATED WITH THE BRITISH COLUMBIA SHORTWAVE AS IT DIGS SOUTHEAST INTO CENTRAL MN...THEN EJECTS NORTHEAST OVER DULUTH. THUS...THE AREA ISNT DIRECTLY HIT BY THE MID-UPPER TROPOSPHERIC FORCING...WHICH FAVORS BETTER CONVECTION TO EJECT NORTHEAST...BUT BROAD ASCENT FROM LARGE SCALE FORCING IS OVER THE AREA. THE CAPE AXIS IS VERY NARROW...RIGHT ALONG THE FRONT...WITH A STOUT CAP OUT AHEAD SUGGESTED. MUCAPE HAS REMARKABLE DROP SUGGESTED IN THE MODEL GUIDANCE FROM 7PM TO 1 AM...ABOUT 2500 IN PEAK HEATING WEST OF THE FORECAST AREA...TO ABOUT 750 J/KG BY 1 AM ON THE MISS RIVER. THE WESTERN FORECAST AREAS OF NERN IA AND SERN MN HAVE THE MOST POTENTIAL FOR SEVERE STORMS FOR A SMALL WINDOW SATURDAY EVENING AS THE STORMS WEAKEN HEADING EAST. SPC DAY 2 RISK HAS SHIFTED THE SLIGHT RISK EAST INTO THAT AREA...BUT NOT TOO MUCH HAS CHANGED. MODEST 0-3KM WIND SHEAR WOULD FAVOR LINE SEGMENTS PROMOTING DAMAGING WINDS. THE 0-3KM SHEAR VECTOR IS ALIGNED PERPENDICULAR TO THE FRONT OR CONVECTIVE LINE...PROMOTING BETTER COLD POOL MAINTENANCE. SEVERE THREAT DEPENDS ON TIMING OF THE FRONT AND STORMS. ARRIVAL IN THE EARLY EVENING WOULD FAVOR HIGHER SEVERE STORM CHANCES PER HIGHER CAPE IN MODEST LOW-LEVEL SHEAR. CONSENSUS MODEL GUIDANCE IS A MID-LATER EVENING APPROACH OF STORMS IN NERN IA AND SERN MN WITH STORMS JUST PAST PEAK AND INTO WEAKENING STAGE...WITH COLD POOLS THAT COULD PROBABLY PRODUCE ISOLATED WIND DAMAGE. WILL TAKE A SLIGHT STEP UP IN MESSAGING MOVING TO STRONG TO ISOLATED SEVERE STORMS. A COOL FIRST HALF OF THE WEEK IN NORTHWEST FLOW WITH DRIER && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1242 PM CDT FRI AUG 21 2015 MAIN TAF CONCERNS ARE WINDY CONDITIONS AT BOTH TAF SITES THROUGH TAF PERIOD. LATEST METARS INDICATE SOUTH TO SOUTHWEST WINDS HAVE INCREASED TO 15 KNOTS WITH GUST OF 20 TO 28 KNOTS ACROSS THE AREA. DUE TO FULL SUN THIS AFTERNOON...WINDS WILL MIX DOWN FROM ALOFT AND CONTINUE TO BE SUSTAINED AT 15 TO 17 KNOTS WITH GUSTS 25 TO 30 KNOTS AT BOTH RST/LSE TAF SITES. WINDS WILL SLACK OFF A BIT AFTER 00Z WITH SUNSET. HOWEVER...SUSTAINED WINDS ARE EXPECTED TO BE AROUND 15 KNOTS THROUGH THE NIGHT TIME HOURS. PRESSURE GRADIENT TIGHTENS AHEAD OF AN APPROACHING COLD FRONT SATURDAY AND EXPECT WINDS TO INCREASE AFTER 12Z AT BOTH RST/LSE TAF SITES. SUSTAINED WINDS OF 15 KNOTS WILL PREVAIL AND GUSTS 25 TO 30 KNOTS...AND POTENTIALLY GUST TO AROUND 35 KNOTS AT RST TAF SITE LATE IN THE TAF PERIOD. VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIODS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BAUMGARDT LONG TERM...BAUMGARDT AVIATION...DTJ