Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/13/14


AREA FORECAST DISCUSSION
NWS PHOENIX AZ
335 PM MST THU SEP 11 2014 .UPDATE...UPDATED FIRE WEATHER DISCUSSION. && .SYNOPSIS... THE COMBINATION OF A RATHER DRY AIRMASS AND HIGH PRESSURE ALOFT IS EXPECTED TO KEEP SKIES MAINLY CLEAR OVER THE REGION THROUGH FRIDAY. A VERY SLOW INCREASE IN MOISTURE WILL BEGIN LATE FRIDAY...THEN CONTINUE INTO THE WEEKEND...AND INTO NEXT WEEK AS THE FLOW ALOFT BECOMES MORE SOUTHEASTERLY. THIS WILL LEAD TO INCREASED CHANCES OF SHOWERS AND THUNDERSTORMS...INITIALLY OVER MOUNTAINOUS AREAS OVER THE WEEKEND...BUT POSSIBLY SPREADING INTO LOWER DESERT LOCATIONS BY EARLY NEXT WEEK. && .DISCUSSION... LATEST RAP STREAMLINE ANALYSIS SHOWS A WEAK UPPER LEVEL TROUGH SITUATED ACROSS AZ. SOMEWHAT DEEPER MOISTURE IS EVIDENT ON WV IMAGERY EAST OF THE TROUGH ACROSS SOUTHERN AND EASTERN AZ...THOUGH REGIONAL SOUNDINGS INDICATE PWATS ARE ONLY IN THE 1.0-1.2 INCH RANGE. ISOLATED CU HAS DEVELOPED ACROSS A FEW RIDGETOPS THIS AFTERNOON...THOUGH A LACK OF CAPE IS LIMITING VERTICAL DEVELOPMENT. CONSENSUS OF CONVECTIVE ALLOWING MODELS SUGGESTS THAT ISOLATED SHOWER AND THUNDERSTORM ACTIVITY WILL REMAIN CONFINED TO SOUTHERN AND EASTERN AZ THIS AFTERNOON. CONTINUED WARMING AND DRYING TREND EXPECTED FRIDAY AS THE SUBTROPICAL RIDGE REMAINS THE PREDOMINANT WEATHER FEATURE. AGAIN...LITTLE CHANCE FOR CONVECTION EXCEPT FOR ISOLATED ACTIVITY IN THE VICINITY OF THE DEEPEST MOISTURE ACROSS SOUTHEASTERN AZ. && .PREVIOUS DISCUSSION... SATURDAY AND SUNDAY... A SLOW INCREASE IN THE AVAILABLE MOISTURE LEVELS IS STILL EXPECTED TO OCCUR OVER THE UPCOMING WEEKEND AS THE FLOW BELOW 400MB BECOMES EASTERLY TO SOUTHEASTERLY...AND BEGINS TO PULL MOISTURE BACK INTO THE REGION. THE GFS IS MOST BULLISH ON THIS MOISTURE INCREASE...PUSHING PWATS UP TO NEAR 1.50 ON SATURDAY...WHILE THE EURO KEEPS THEM MAINLY AOB 1.20 INCH. CONSIDERING THAT THE PRIMARY REASON FOR THE INCREASE IN THE SFC PRESSURE GRADIENT/EASTERLY FLOW IN THE LOW LEVELS IS THE FACT THAT A RATHER STRONG...AND QUITE COLD SFC HIGH IS FORECAST TO DIVE SOUTHWARD INTO THE CENTRAL AND SOUTHERN PLAINS...WITH ITS ORIGINS BEING FROM NORTHERN CANADA/ALASKA...RATHER THAN A MORE TYPICAL SUBTROPICAL HIGH THAT OFTEN BUILDS OVER THAT REGION THIS TIME OF YEAR...I AM INCLINED TO GO WITH THE DRIER EURO FOR NOW. STILL...THERE SHOULD BE ENOUGH MOISTURE/INSTABILITY TO KEEP SLIGHT CHANCES FOR SHOWERS/THUNDERSTORMS OVER THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX IN THE FORECAST...BUT WITH MAINLY SINGLE DIGIT POPS OVER THE LOWER DESERTS. HIGH TEMPERATURES ARE EXPECTED TO REMAIN MOSTLY IN THE 105-108F RANGE ACROSS SE CA AND SW AZ...BUT COOL A DEGREE OR TWO OVER SOUTH-CENTRAL AZ AS A BIT OF COOLER AIR WORKS ITS WAY IN FROM THE EAST. MONDAY THROUGH WEDNESDAY... A FURTHER MOISTURE INCREASE IS STILL EXPECTED DURING THIS TIME PERIOD AS HURRICANE ODILE MOVES NORTHWESTWARD JUST OFF THE WEST COAST OF BAJA CALIFORNIA. DEEP SE-LY FLOW TO THE EAST AND NORTHEAST OF ODILE WILL LIKELY PUSH ADDITIONAL MOISTURE NORTHWESTWARD UP THE GULF OF CALIFORNIA...AND INTO THE DESERT SOUTHWEST. ALTHOUGH THERE WILL LIKELY BE ENOUGH INCREASE IN AVAILABLE MOISTURE TO TRIGGER AT LEAST ISOLATED THUNDERSTORMS ACROSS THE LOWER DESERTS OF AZ/SE CA DURING THIS PERIOD...IT STILL APPEARS THAT WE WILL NOT SEE ANYTHING CLOSE TO WHAT WE SAW EARLIER THIS WEEK...SINCE LATEST MODEL SUITES ARE IN VERY STRONG AGREEMENT THAT ODILE WILL TRACK WELL OFF TO OUR SOUTH AND WEST...EVENTUALLY DISSIPATING OVER THE COOLER WATERS OF THE EASTERN PACIFIC...WELL OFF THE SOUTHERN CA COAST...WITH MOST OF ITS ASSOCIATED MOISTURE REMAINING FAR AWAY FROM OUR REGION. THUS...ONCE AGAIN GOING WITH THE DRIER EURO...WHICH KEEPS OUR PWATS MAINLY AOB 1.50 INCH THROUGH THIS PERIOD. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... NO AVIATION IMPACTS THROUGH FRIDAY MORNING...AS ONLY A FEW AFTERNOON CU OVER TERRAIN FEATURES WILL PREVAIL ACROSS THE TERMINAL REGION. SFC WINDS WILL REMAIN VERY LIGHT AOB 10 KT WITH MODERATE CONFIDENCE OF WIND SHIFT TIMING. IN MANY LOCATIONS AFTER SUNSET...WINDS WILL BE NEARLY CALM. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SUNDAY THROUGH THURSDAY... INCREASING LOW TO MID LEVEL EASTERLY WINDS WILL DEVELOP OVER THE WEEKEND...HELPING TO SPREAD MONSOONAL MOISTURE AND AN INCREASING THREAT OF AFTERNOON AND EVENING THUNDERSTORMS BACK OVER THE REGION. BY SUNDAY A SLIGHT CHANCE OF THUNDERSTORMS IS FORECAST ACROSS THE ARIZONA DESERTS. HUMIDITY VALUES ACROSS THE DESERTS WILL BEGIN A STEADY RISE OVER THE WEEKEND AND INTO NEXT WEEK WITH MINIMUM VALUES FOR MOST AREAS CLIMBING ABOVE 20 PERCENT BY SUNDAY. OVERNIGHT RECOVERY WILL BE GENERALLY GOOD THROUGH MONDAY WITH MAX HUMIDITY VALUES CLIMBING ABOVE 50 PERCENT EACH NIGHT...BECOMING GOOD TO EXCELLENT EARLY NEXT WEEK WITH MANY DESERT LOCALES EXCEEDING 70 PERCENT BY WEDNESDAY MORNING. THE BREEZY EAST WINDS SEEN OVER THE WEEKEND WILL DIMINISH THROUGH THE MIDDLE OF NEXT WEEK...FAVORING THE SOUTH TO SOUTHWEST DIRECTIONS AT GENERALLY LESS THAN 15 MPH. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...HIRSCH PREVIOUS DISCUSSION...PERCHA AVIATION...MO FIRE WEATHER...MCLANE/CB
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
325 PM MST THU SEP 11 2014 .SYNOPSIS... THE COMBINATION OF A RATHER DRY AIRMASS AND HIGH PRESSURE ALOFT IS EXPECTED TO KEEP SKIES MAINLY CLEAR OVER THE REGION THROUGH FRIDAY. A VERY SLOW INCREASE IN MOISTURE WILL BEGIN LATE FRIDAY...THEN CONTINUE INTO THE WEEKEND...AND INTO NEXT WEEK AS THE FLOW ALOFT BECOMES MORE SOUTHEASTERLY. THIS WILL LEAD TO INCREASED CHANCES OF SHOWERS AND THUNDERSTORMS...INITIALLY OVER MOUNTAINOUS AREAS OVER THE WEEKEND...BUT POSSIBLY SPREADING INTO LOWER DESERT LOCATIONS BY EARLY NEXT WEEK. && .DISCUSSION... LATEST RAP STREAMLINE ANALYSIS SHOWS A WEAK UPPER LEVEL TROUGH SITUATED ACROSS AZ. SOMEWHAT DEEPER MOISTURE IS EVIDENT ON WV IMAGERY EAST OF THE TROUGH ACROSS SOUTHERN AND EASTERN AZ...THOUGH REGIONAL SOUNDINGS INDICATE PWATS ARE ONLY IN THE 1.0-1.2 INCH RANGE. ISOLATED CU HAS DEVELOPED ACROSS A FEW RIDGETOPS THIS AFTERNOON...THOUGH A LACK OF CAPE IS LIMITING VERTICAL DEVELOPMENT. CONSENSUS OF CONVECTIVE ALLOWING MODELS SUGGESTS THAT ISOLATED SHOWER AND THUNDERSTORM ACTIVITY WILL REMAIN CONFINED TO SOUTHERN AND EASTERN AZ THIS AFTERNOON. CONTINUED WARMING AND DRYING TREND EXPECTED FRIDAY AS THE SUBTROPICAL RIDGE REMAINS THE PREDOMINANT WEATHER FEATURE. AGAIN...LITTLE CHANCE FOR CONVECTION EXCEPT FOR ISOLATED ACTIVITY IN THE VICINITY OF THE DEEPEST MOISTURE ACROSS SOUTHEASTERN AZ. && .PREVIOUS DISCUSSION... SATURDAY AND SUNDAY... A SLOW INCREASE IN THE AVAILABLE MOISTURE LEVELS IS STILL EXPECTED TO OCCUR OVER THE UPCOMING WEEKEND AS THE FLOW BELOW 400MB BECOMES EASTERLY TO SOUTHEASTERLY...AND BEGINS TO PULL MOISTURE BACK INTO THE REGION. THE GFS IS MOST BULLISH ON THIS MOISTURE INCREASE...PUSHING PWATS UP TO NEAR 1.50 ON SATURDAY...WHILE THE EURO KEEPS THEM MAINLY AOB 1.20 INCH. CONSIDERING THAT THE PRIMARY REASON FOR THE INCREASE IN THE SFC PRESSURE GRADIENT/EASTERLY FLOW IN THE LOW LEVELS IS THE FACT THAT A RATHER STRONG...AND QUITE COLD SFC HIGH IS FORECAST TO DIVE SOUTHWARD INTO THE CENTRAL AND SOUTHERN PLAINS...WITH ITS ORIGINS BEING FROM NORTHERN CANADA/ALASKA...RATHER THAN A MORE TYPICAL SUBTROPICAL HIGH THAT OFTEN BUILDS OVER THAT REGION THIS TIME OF YEAR...I AM INCLINED TO GO WITH THE DRIER EURO FOR NOW. STILL...THERE SHOULD BE ENOUGH MOISTURE/INSTABILITY TO KEEP SLIGHT CHANCES FOR SHOWERS/THUNDERSTORMS OVER THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX IN THE FORECAST...BUT WITH MAINLY SINGLE DIGIT POPS OVER THE LOWER DESERTS. HIGH TEMPERATURES ARE EXPECTED TO REMAIN MOSTLY IN THE 105-108F RANGE ACROSS SE CA AND SW AZ...BUT COOL A DEGREE OR TWO OVER SOUTH-CENTRAL AZ AS A BIT OF COOLER AIR WORKS ITS WAY IN FROM THE EAST. MONDAY THROUGH WEDNESDAY... A FURTHER MOISTURE INCREASE IS STILL EXPECTED DURING THIS TIME PERIOD AS HURRICANE ODILE MOVES NORTHWESTWARD JUST OFF THE WEST COAST OF BAJA CALIFORNIA. DEEP SE-LY FLOW TO THE EAST AND NORTHEAST OF ODILE WILL LIKELY PUSH ADDITIONAL MOISTURE NORTHWESTWARD UP THE GULF OF CALIFORNIA...AND INTO THE DESERT SOUTHWEST. ALTHOUGH THERE WILL LIKELY BE ENOUGH INCREASE IN AVAILABLE MOISTURE TO TRIGGER AT LEAST ISOLATED THUNDERSTORMS ACROSS THE LOWER DESERTS OF AZ/SE CA DURING THIS PERIOD...IT STILL APPEARS THAT WE WILL NOT SEE ANYTHING CLOSE TO WHAT WE SAW EARLIER THIS WEEK...SINCE LATEST MODEL SUITES ARE IN VERY STRONG AGREEMENT THAT ODILE WILL TRACK WELL OFF TO OUR SOUTH AND WEST...EVENTUALLY DISSIPATING OVER THE COOLER WATERS OF THE EASTERN PACIFIC...WELL OFF THE SOUTHERN CA COAST...WITH MOST OF ITS ASSOCIATED MOISTURE REMAINING FAR AWAY FROM OUR REGION. THUS...ONCE AGAIN GOING WITH THE DRIER EURO...WHICH KEEPS OUR PWATS MAINLY AOB 1.50 INCH THROUGH THIS PERIOD. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... NO AVIATION IMPACTS THROUGH FRIDAY MORNING...AS ONLY A FEW AFTERNOON CU OVER TERRAIN FEATURES WILL PREVAIL ACROSS THE TERMINAL REGION. SFC WINDS WILL REMAIN VERY LIGHT AOB 10 KT WITH MODERATE CONFIDENCE OF WIND SHIFT TIMING. IN MANY LOCATIONS AFTER SUNSET...WINDS WILL BE NEARLY CALM. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SATURDAY THROUGH WEDNESDAY. INCREASING LOW TO MID LEVEL EASTERLY WINDS WILL DEVELOP OVER THE WEEKEND...HELPING TO SPREAD MONSOONAL MOISTURE AND AN INCREASING THREAT OF AFTERNOON AND EVENING THUNDERSTORMS BACK OVER THE REGION. BY SUNDAY A SLIGHT CHANCE OF THUNDERSTORMS IS FORECAST ACROSS THE ARIZONA DESERTS. HUMIDITY VALUES ACROSS THE DESERTS WILL BEGIN A STEADY RISE OVER THE WEEKEND AND INTO NEXT WEEK WITH MINIMUM VALUES FOR MOST AREAS CLIMBING ABOVE 20 PERCENT BY SUNDAY. OVERNIGHT RECOVERY WILL BE GENERALLY GOOD THROUGH MONDAY WITH MAX HUMIDITY VALUES CLIMBING ABOVE 50 PERCENT EACH NIGHT...BECOMING GOOD TO EXCELLENT EARLY NEXT WEEK WITH MANY DESERT LOCALES EXCEEDING 70 PERCENT BY WEDNESDAY MORNING. THE BREEZY EAST WINDS SEEN OVER THE WEEKEND WILL DIMINISH THROUGH THE MIDDLE OF NEXT WEEK...FAVORING THE SOUTH TO SOUTHWEST DIRECTIONS AT GENERALLY LESS THAN 15 MPH. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...HIRSCH PREVIOUS DISCUSSION...PERCHA AVIATION...MO FIRE WEATHER...MCLANE/CB
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
1255 PM MST THU SEP 11 2014 ...UPDATED AVIATION... .SYNOPSIS... THE COMBINATION OF A RATHER DRY AIRMASS AND HIGH PRESSURE ALOFT IS EXPECTED TO KEEP SKIES MAINLY CLEAR OVER THE REGION THROUGH FRIDAY. A VERY SLOW INCREASE IN MOISTURE WILL BEGIN LATE FRIDAY...THEN CONTINUE INTO THE WEEKEND...AND INTO NEXT WEEK AS THE FLOW ALOFT BECOMES MORE SOUTHEASTERLY. THIS WILL LEAD TO INCREASED CHANCES OF SHOWERS AND THUNDERSTORMS...INITIALLY OVER MOUNTAINOUS AREAS OVER THE WEEKEND...BUT POSSIBLY SPREADING INTO LOWER DESERT LOCATIONS BY EARLY NEXT WEEK. && .DISCUSSION... LATEST RAP STREAMLINE ANALYSIS SHOWS A WEAK UPPER LEVEL TROUGH SITUATED ACROSS AZ. SOMEWHAT DEEPER MOISTURE IS EVIDENT ON WV IMAGERY EAST OF THE TROUGH ACROSS SOUTHERN AND EASTERN AZ...THOUGH REGIONAL SOUNDINGS INDICATE PWATS ARE ONLY IN THE 1.0-1.2 INCH RANGE. CONSENSUS OF CONVECTIVE ALLOWING MODELS SUGGESTS THAT ISOLATED SHOWER AND THUNDERSTORM ACTIVITY WILL REMAIN CONFINED TO THESE AREAS THIS AFTERNOON AND THIS IS REFLECTED IN THE CURRENT FORECAST. ONLY MINOR ADJUSTMENTS TO THE SHORT-TERM TEMPERATURES AND DEWPOINTS WERE NEEDED THIS MORNING. && .PREVIOUS DISCUSSION... TODAY THROUGH FRIDAY... WESTERLY FLOW ALOFT OVER THE LAST 24-36 HOURS HAS NOW PUSHED ENOUGH DRY AIR INTO THE REGION TO PUSH PWATS ACROSS MUCH OF OUR REGION TO AOB 1.00 INCH. AS A RESULT...SKIES HAVE BECOME MOSTLY CLEAR WITH THE MAIN MOISTURE PLUME NOW DISPLACED WELL TO OUR SOUTH AND EAST...EXTENDING NORTHEASTWARD FROM NORTHERN MEXICO ACROSS SE NM INTO W TX. NOT MUCH CHANGE IN THE SENSIBLE WEATHER IS EXPECTED THROUGH FRIDAY AS WESTERLY FLOW CONTINUES OVER THE REGION. HIGH TEMPERATURES ARE EXPECTED TO RISE TO NEAR 100 ACROSS THE LOWER DESERTS TODAY...AND UP INTO THE 103-108F RANGE ON FRIDAY AS 700MB TEMPS RISE FROM AROUND 11C TODAY TO AROUND 13 ON FRIDAY. SATURDAY AND SUNDAY... A SLOW INCREASE IN THE AVAILABLE MOISTURE LEVELS IS STILL EXPECTED TO OCCUR OVER THE UPCOMING WEEKEND AS THE FLOW BELOW 400MB BECOMES EASTERLY TO SOUTHEASTERLY...AND BEGINS TO PULL MOISTURE BACK INTO THE REGION. THE GFS IS MOST BULLISH ON THIS MOISTURE INCREASE...PUSHING PWATS UP TO NEAR 1.50 ON SATURDAY...WHILE THE EURO KEEPS THEM MAINLY AOB 1.20 INCH. CONSIDERING THAT THE PRIMARY REASON FOR THE INCREASE IN THE SFC PRESSURE GRADIENT/EASTERLY FLOW IN THE LOW LEVELS IS THE FACT THAT A RATHER STRONG...AND QUITE COLD SFC HIGH IS FORECAST TO DIVE SOUTHWARD INTO THE CENTRAL AND SOUTHERN PLAINS...WITH ITS ORIGINS BEING FROM NORTHERN CANADA/ALASKA...RATHER THAN A MORE TYPICAL SUBTROPICAL HIGH THAT OFTEN BUILDS OVER THAT REGION THIS TIME OF YEAR...I AM INCLINED TO GO WITH THE DRIER EURO FOR NOW. STILL...THERE SHOULD BE ENOUGH MOISTURE/INSTABILITY TO KEEP SLIGHT CHANCES FOR SHOWERS/THUNDERSTORMS OVER THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX IN THE FORECAST...BUT WITH MAINLY SINGLE DIGIT POPS OVER THE LOWER DESERTS. HIGH TEMPERATURES ARE EXPECTED TO REMAIN MOSTLY IN THE 105-108F RANGE ACROSS SE CA AND SW AZ...BUT COOL A DEGREE OR TWO OVER SOUTH-CENTRAL AZ AS A BIT OF COOLER AIR WORKS ITS WAY IN FROM THE EAST. MONDAY THROUGH WEDNESDAY... A FURTHER MOISTURE INCREASE IS STILL EXPECTED DURING THIS TIME PERIOD AS HURRICANE ODILE MOVES NORTHWESTWARD JUST OFF THE WEST COAST OF BAJA CALIFORNIA. DEEP SE-LY FLOW TO THE EAST AND NORTHEAST OF ODILE WILL LIKELY PUSH ADDITIONAL MOISTURE NORTHWESTWARD UP THE GULF OF CALIFORNIA...AND INTO THE DESERT SOUTHWEST. ALTHOUGH THERE WILL LIKELY BE ENOUGH INCREASE IN AVAILABLE MOISTURE TO TRIGGER AT LEAST ISOLATED THUNDERSTORMS ACROSS THE LOWER DESERTS OF AZ/SE CA DURING THIS PERIOD...IT STILL APPEARS THAT WE WILL NOT SEE ANYTHING CLOSE TO WHAT WE SAW EARLIER THIS WEEK...SINCE LATEST MODEL SUITES ARE IN VERY STRONG AGREEMENT THAT ODILE WILL TRACK WELL OFF TO OUR SOUTH AND WEST...EVENTUALLY DISSIPATING OVER THE COOLER WATERS OF THE EASTERN PACIFIC...WELL OFF THE SOUTHERN CA COAST...WITH MOST OF ITS ASSOCIATED MOISTURE REMAINING FAR AWAY FROM OUR REGION. THUS...ONCE AGAIN GOING WITH THE DRIER EURO...WHICH KEEPS OUR PWATS MAINLY AOB 1.50 INCH THROUGH THIS PERIOD. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... NO AVIATION IMPACTS THROUGH FRIDAY MORNING...AS ONLY A FEW AFTERNOON CU OVER TERRAIN FEATURES WILL PREVAIL ACROSS THE TERMINAL REGION. SFC WINDS WILL REMAIN VERY LIGHT AOB 10 KT WITH MODERATE CONFIDENCE OF WIND SHIFT TIMING. IN MANY LOCATIONS AFTER SUNSET...WINDS WILL BE NEARLY CALM. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SATURDAY THROUGH WEDNESDAY. INCREASING LOW TO MID LEVEL EASTERLY WINDS WILL DEVELOP OVER THE WEEKEND...HELPING TO SPREAD MONSOONAL MOISTURE AND AN INCREASING THREAT OF AFTERNOON AND EVENING THUNDERSTORMS BACK OVER THE REGION. BY SUNDAY A SLIGHT CHANCE OF THUNDERSTORMS IS FORECAST ACROSS THE ARIZONA DESERTS. HUMIDITY VALUES ACROSS THE DESERTS WILL BEGIN A STEADY RISE OVER THE WEEKEND AND INTO NEXT WEEK WITH MINIMUM VALUES FOR MOST AREAS CLIMBING ABOVE 20 PERCENT BY SUNDAY. OVERNIGHT RECOVERY WILL BE GENERALLY GOOD THROUGH MONDAY WITH MAX HUMIDITY VALUES CLIMBING ABOVE 50 PERCENT EACH NIGHT...BECOMING GOOD TO EXCELLENT EARLY NEXT WEEK WITH MANY DESERT LOCALES EXCEEDING 70 PERCENT BY WEDNESDAY MORNING. THE BREEZY EAST WINDS SEEN OVER THE WEEKEND WILL DIMINISH THROUGH THE MIDDLE OF NEXT WEEK...FAVORING THE SOUTH TO SOUTHWEST DIRECTIONS AT GENERALLY LESS THAN 15 MPH. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...HIRSCH PREVIOUS DISCUSSION...PERCHA AVIATION...MO FIRE WEATHER...MCLANE/CB
AREA FORECAST DISCUSSION
NWS TUCSON AZ
945 AM MST THU SEP 11 2014 .SYNOPSIS...A FEW SHOWERS AND THUNDERSTORMS WILL OCCUR THIS AFTERNOON AND EVENING MAINLY NEAR THE NEW MEXICO BORDER. EXPECT ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ON FRIDAY AND CONTINUING INTO NEXT WEEK AS MOISTURE GRADUALLY INCREASES. WARMER DAYTIME TEMPERATURES WILL PREVAIL THROUGH FRIDAY FOLLOWED BY MODEST COOLING EARLY THIS WEEKEND. && .DISCUSSION...SUNNY SKIES ACROSS MUCH OF SE AZ AT THIS TIME WITH THE EXCEPTION OF A FEW CIRRIFORM CLOUDS MAINLY SE OF TUCSON. DEWPOINTS AT LOWER ELEVATIONS VALID 16Z WERE IN THE MID-UPPER 50S...AND THESE TEMPS WERE NEARLY 2-5 DEGS F LOWER VERSUS 24 HOURS AGO. SURFACE TEMPS VALID 16Z WERE ABOUT 2-5 DEGS F WARMER VERSUS THIS TIME WED. 11/12Z KTWC SOUNDING TOTAL PRECIP WATER WAS 1.05 INCHES...AND LIGHT WLY/SWLY FLOW PREVAILED ABOVE 700 MB. 11/12Z NAM/GFS...11/12Z UNIV OF AZ WRF-NAM...AND THE 11/14Z RUC HRRR WERE SIMILAR WITH DEPICTING A FEW SHOWERS/TSTMS TO OCCUR THIS AFTERNOON AND THIS EVENING MAINLY NEAR THE NEW MEXICO BORDER. THE WRF-NAM AND HRRR WERE ALSO SIMILAR WITH DEPICTING THE INITIAL DEVELOPMENT OF SHOWERS/TSTMS TO OCCUR ON THE CHIRICAHUA MOUNTAINS AROUND 18Z-19Z. THESE NWP MODELS DEPICT SHOWERS/TSTMS TO END BY ABOUT 12/02Z-03Z...OR SHORTLY AFTER SUNSET. ANY RAINFALL AMOUNTS WILL BE QUITE LIGHT THIS AFTERNOON AND EVENING. OTHERWISE...CLEAR SKIES OR MOSTLY CLEAR SKIES INTO FRIDAY MORNING WEST OF TUCSON... AND MOSTLY CLEAR SKIES TO PARTLY CLOUDY SKIES ELSEWHERE. HIGH TEMPS THIS AFTERNOON WILL BE ABOUT 3-6 DEGS F WARMER ACROSS THE AREA VERSUS WED. THERE ARE NO UPDATES PLANNED AT THIS TIME. PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL. && .AVIATION...VALID THRU 12/12Z. CLEAR SKIES WILL PREVAIL WEST OF KTUS THRU FRIDAY MORNING. KTUS VICINITY EASTWARD EXPECT A FEW-SCT CLOUDS AT 8-12K FT AGL MAINLY THIS AFTERNOON AND EVENING. THERE IS A SLIGHT CHANCE OF -SHRA/-TSRA MAINLY NEAR THE NEW MEXICO BORDER THIS AFTERNOON AND THIS EVENING. MOSTLY CLEAR SKIES SHOULD PREVAIL LATE TONIGHT INTO FRIDAY MORNING. SURFACE WIND WILL GENERALLY BE LESS THAN 10 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...THERE IS A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING MAINLY NEAR THE NEW MEXICO BORDER. ISOLATED TO SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL THEN RETURN STARTING FRIDAY AND CONTINUE INTO NEXT WEEK AS MOISTURE GRADUALLY INCREASES ACROSS THE AREA. 20-FOOT WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN...EXCEPT FOR STRONG GUSTY OUTFLOWS ASSOCIATED WITH THUNDERSTORMS. && .PREV DISCUSSION...BY FRIDAY INCREASING WINDS TO OUR EAST OVER WEST TEXAS AND SOUTHERN NEW MEXICO THAT ARE ASSOCIATED WITH THE BOUNDARY/ BACKDOOR FRONT WILL HELP TO USHER IN ADDITIONAL MOISTURE. AS A RESULT OUR RAIN CHANCES WILL INCREASE...WITH ISOLATED SHOWER AND THUNDERSTORM ACTIVITY FOR CENTRAL DESERTS...INCLUDING TUCSON AND SCATTERED ACTIVITY OVER THE EASTERN ZONES BETWEEN TUCSON AND THE NEW MEXICO BORDER. FOR SATURDAY AND SUNDAY WE WILL STILL MAINTAIN GENERALLY ISOLATED POPS FOR MOST AREAS WITH SCATTERED POPS FOR THE WHITE MOUNTAINS. AS ANOTHER TROPICAL SYSTEM (ODILE)...HEADS TO THE NORTHWEST AND EVENTUALLY ALONG THE WEST COAST OF THE BAJA PENINSULA...REACHING A POSITION A COUPLE OF HUNDRED MILES WEST OF THE SOUTH CENTRAL BAJA PENINSULA BY AROUND LATE MONDAY...WE SHOULD SEE SOME INFLUENCE WITH AN INCREASE IN SHOWER AND THUNDERSTORM ACTIVITY AS MODELS ARE SHOWING ACTIVITY DEVELOPING OVER NORTHERN MEXICO AND INTO PARTS OF SOUTHERN ARIZONA. HOWEVER...THE WINDS IN THIS CASE WILL USHER MOISTURE MOSTLY TO THE WEST OR WEST NORTHWEST...KEEPING THE BULK OF THE SHOWERS AND THUNDERSTORMS TO OUR SOUTH. THAT SAID...JUST HAVE CHANCE CATEGORY POPS ALONG THE INTERNATIONAL BORDER BEGINNING MONDAY AND CONTINUING THROUGH THE MIDDLE OF NEXT WEEK. MORE NORTHERN PARTS OF MY FORECAST AREA WILL STILL SEE SLIGHT CHANCE TYPE POPS FOR DESERTS/VALLEYS AND CHANCE POPS FOR THE MOUNTAINS DURING THAT PERIOD. OF COURSE THE FORECAST FOR NEXT WEEK WILL CONTINUALLY BE REEVALUATED WITH EACH NEW MODEL RUN...SO STAY TUNED FOR CHANGES AND ENHANCEMENTS TO THE FORECAST BETWEEN NOW AND EARLY NEXT WEEK. HIGH TEMPERATURES WILL GENERALLY BE 1 TO 3 DEGS ABOVE NORMAL TODAY AND ESPECIALLY FRIDAY...THEN NEAR OR SLIGHTLY BELOW NORMAL FOR SATURDAY. THEREAFTER...HIGHS AT OR SLIGHTLY ABOVE NORMAL EACH DAY. LOW TEMPS WILL BE SEVERAL DEGREES ABOVE NORMAL EACH MORNING. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON DISCUSSION...FRANCIS PREVIOUS DISCUSSION...MOLLERE
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
930 AM MST THU SEP 11 2014 .SYNOPSIS... THE COMBINATION OF A RATHER DRY AIRMASS AND HIGH PRESSURE ALOFT IS EXPECTED TO KEEP SKIES MAINLY CLEAR OVER THE REGION THROUGH FRIDAY. A VERY SLOW INCREASE IN MOISTURE WILL BEGIN LATE FRIDAY...THEN CONTINUE INTO THE WEEKEND...AND INTO NEXT WEEK AS THE FLOW ALOFT BECOMES MORE SOUTHEASTERLY. THIS WILL LEAD TO INCREASED CHANCES OF SHOWERS AND THUNDERSTORMS...INITIALLY OVER MOUNTAINOUS AREAS OVER THE WEEKEND...BUT POSSIBLY SPREADING INTO LOWER DESERT LOCATIONS BY EARLY NEXT WEEK. && .DISCUSSION... LATEST RAP STREAMLINE ANALYSIS SHOWS A WEAK UPPER LEVEL TROUGH SITUATED ACROSS AZ. SOMEWHAT DEEPER MOISTURE IS EVIDENT ON WV IMAGERY EAST OF THE TROUGH ACROSS SOUTHERN AND EASTERN AZ...THOUGH REGIONAL SOUNDINGS INDICATE PWATS ARE ONLY IN THE 1.0-1.2 INCH RANGE. CONSENSUS OF CONVECTIVE ALLOWING MODELS SUGGESTS THAT ISOLATED SHOWER AND THUNDERSTORM ACTIVITY WILL REMAIN CONFINED TO THESE AREAS THIS AFTERNOON AND THIS IS REFLECTED IN THE CURRENT FORECAST. ONLY MINOR ADJUSTMENTS TO THE SHORT-TERM TEMPERATURES AND DEWPOINTS WERE NEEDED THIS MORNING. && .PREVIOUS DISCUSSION... TODAY THROUGH FRIDAY... WESTERLY FLOW ALOFT OVER THE LAST 24-36 HOURS HAS NOW PUSHED ENOUGH DRY AIR INTO THE REGION TO PUSH PWATS ACROSS MUCH OF OUR REGION TO AOB 1.00 INCH. AS A RESULT...SKIES HAVE BECOME MOSTLY CLEAR WITH THE MAIN MOISTURE PLUME NOW DISPLACED WELL TO OUR SOUTH AND EAST...EXTENDING NORTHEASTWARD FROM NORTHERN MEXICO ACROSS SE NM INTO W TX. NOT MUCH CHANGE IN THE SENSIBLE WEATHER IS EXPECTED THROUGH FRIDAY AS WESTERLY FLOW CONTINUES OVER THE REGION. HIGH TEMPERATURES ARE EXPECTED TO RISE TO NEAR 100 ACROSS THE LOWER DESERTS TODAY...AND UP INTO THE 103-108F RANGE ON FRIDAY AS 700MB TEMPS RISE FROM AROUND 11C TODAY TO AROUND 13 ON FRIDAY. SATURDAY AND SUNDAY... A SLOW INCREASE IN THE AVAILABLE MOISTURE LEVELS IS STILL EXPECTED TO OCCUR OVER THE UPCOMING WEEKEND AS THE FLOW BELOW 400MB BECOMES EASTERLY TO SOUTHEASTERLY...AND BEGINS TO PULL MOISTURE BACK INTO THE REGION. THE GFS IS MOST BULLISH ON THIS MOISTURE INCREASE...PUSHING PWATS UP TO NEAR 1.50 ON SATURDAY...WHILE THE EURO KEEPS THEM MAINLY AOB 1.20 INCH. CONSIDERING THAT THE PRIMARY REASON FOR THE INCREASE IN THE SFC PRESSURE GRADIENT/EASTERLY FLOW IN THE LOW LEVELS IS THE FACT THAT A RATHER STRONG...AND QUITE COLD SFC HIGH IS FORECAST TO DIVE SOUTHWARD INTO THE CENTRAL AND SOUTHERN PLAINS...WITH ITS ORIGINS BEING FROM NORTHERN CANADA/ALASKA...RATHER THAN A MORE TYPICAL SUBTROPICAL HIGH THAT OFTEN BUILDS OVER THAT REGION THIS TIME OF YEAR...I AM INCLINED TO GO WITH THE DRIER EURO FOR NOW. STILL...THERE SHOULD BE ENOUGH MOISTURE/INSTABILITY TO KEEP SLIGHT CHANCES FOR SHOWERS/THUNDERSTORMS OVER THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX IN THE FORECAST...BUT WITH MAINLY SINGLE DIGIT POPS OVER THE LOWER DESERTS. HIGH TEMPERATURES ARE EXPECTED TO REMAIN MOSTLY IN THE 105-108F RANGE ACROSS SE CA AND SW AZ...BUT COOL A DEGREE OR TWO OVER SOUTH-CENTRAL AZ AS A BIT OF COOLER AIR WORKS ITS WAY IN FROM THE EAST. MONDAY THROUGH WEDNESDAY... A FURTHER MOISTURE INCREASE IS STILL EXPECTED DURING THIS TIME PERIOD AS HURRICANE ODILE MOVES NORTHWESTWARD JUST OFF THE WEST COAST OF BAJA CALIFORNIA. DEEP SE-LY FLOW TO THE EAST AND NORTHEAST OF ODILE WILL LIKELY PUSH ADDITIONAL MOISTURE NORTHWESTWARD UP THE GULF OF CALIFORNIA...AND INTO THE DESERT SOUTHWEST. ALTHOUGH THERE WILL LIKELY BE ENOUGH INCREASE IN AVAILABLE MOISTURE TO TRIGGER AT LEAST ISOLATED THUNDERSTORMS ACROSS THE LOWER DESERTS OF AZ/SE CA DURING THIS PERIOD...IT STILL APPEARS THAT WE WILL NOT SEE ANYTHING CLOSE TO WHAT WE SAW EARLIER THIS WEEK...SINCE LATEST MODEL SUITES ARE IN VERY STRONG AGREEMENT THAT ODILE WILL TRACK WELL OFF TO OUR SOUTH AND WEST...EVENTUALLY DISSIPATING OVER THE COOLER WATERS OF THE EASTERN PACIFIC...WELL OFF THE SOUTHERN CA COAST...WITH MOST OF ITS ASSOCIATED MOISTURE REMAINING FAR AWAY FROM OUR REGION. THUS...ONCE AGAIN GOING WITH THE DRIER EURO...WHICH KEEPS OUR PWATS MAINLY AOB 1.50 INCH THROUGH THIS PERIOD. && AVIATION... SOUTH-CENTRAL ARIZONA...SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KPHX...KIWA...KSDL...KIPL...AND KBLH... HIGH PRESSURE ALOFT CONTINUES TO BUILD ACROSS THE LOWER DESERTS...AS AS THIS OCCURS DRIER AIR WILL FILTER IN FROM THE WEST. AS SUCH...EXPECT GENERALLY CLEAR SKIES NEXT 24 HOURS WITH POSSIBLY A FEW CU DECKS DURING THE AFTERNOON HOURS AT THE TAF SITES...WITH BASES AOA 6K FEET. OTHERWISE...WINDS TO BE QUITE LIGHT AND VARIABLE AT THE TERMINALS...OCCASIONALLY FOLLOWING NORMAL DIURNAL DIRECTIONS. NO AVIATION IMPACTS EXPECTED NEXT 24 HOURS WITH VFR CONDITIONS AT ALL TERMINALS THROUGH FRIDAY MORNING. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... SATURDAY THROUGH WEDNESDAY. INCREASING LOW TO MID LEVEL EASTERLY WINDS WILL DEVELOP OVER THE WEEKEND...HELPING TO SPREAD MONSOONAL MOISTURE AND AN INCREASING THREAT OF AFTERNOON AND EVENING THUNDERSTORMS BACK OVER THE REGION. BY SUNDAY A SLIGHT CHANCE OF THUNDERSTORMS IS FORECAST ACROSS THE ARIZONA DESERTS. HUMIDITY VALUES ACROSS THE DESERTS WILL BEGIN A STEADY RISE OVER THE WEEKEND AND INTO NEXT WEEK WITH MINIMUM VALUES FOR MOST AREAS CLIMBING ABOVE 20 PERCENT BY SUNDAY. OVERNIGHT RECOVERY WILL BE GENERALLY GOOD THROUGH MONDAY WITH MAX HUMIDITY VALUES CLIMBING ABOVE 50 PERCENT EACH NIGHT...BECOMING GOOD TO EXCELLENT EARLY NEXT WEEK WITH MANY DESERT LOCALES EXCEEDING 70 PERCENT BY WEDNESDAY MORNING. THE BREEZY EAST WINDS SEEN OVER THE WEEKEND WILL DIMINISH THROUGH THE MIDDLE OF NEXT WEEK...FAVORING THE SOUTH TO SOUTHWEST DIRECTIONS AT GENERALLY LESS THAN 15 MPH. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...HIRSCH PREVIOUS DISCUSSION...PERCHA AVIATION...CB FIRE WEATHER...MCLANE/CB
AREA FORECAST DISCUSSION
NWS PUEBLO CO
551 PM MDT FRI SEP 12 2014 .UPDATE... ISSUED AT 549 PM MDT FRI SEP 12 2014 LOOKING AT SAT PIX...AND HI RES RH FIELDS IN THE LOWER LVLS OF THE ATMOSPHERE AND PRGD SOUNDINGS...HAVE PLAYED UP MORE LOW CLOUDS FOR TONIGHT THAN WERE IN EARLIER FCST PRODUCTS. FCST ARE BEING UPDATED AS I WRITE. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 242 PM MDT FRI SEP 12 2014 WIDESPREAD LOW CLOUDS CONTINUE TO COVER THE SERN CO PLAINS THIS AFTERNOON...WITH TEMPS IN THE 40S. THE REST OF THE FORECAST AREA HAS HAD MOSTLY SUNNY SKIES...WITH SOME CONVECTIVE CLOUDS DEVELOPING OVER THE SRN MTNS AND SAN LUIS VALLEY. THERE CONTINUES TO BE SOME SPOTTY LIGHT DRIZZLE IN LOCATIONS NR THE ERN MTNS. THE NAM HAS WAY OVERDONE THE PCPN OVR THE SERN PLAINS FOR TODAY...WITH THE HRRR BEING MORE REASONABLE. FOR THIS EVENING AND OVERNIGHT THE NAM PRINTS OUT SOME ISOLD PCPN OVR THE SRN CO MTNS. THE HRRR IS DRY FOR THIS EVENING. IT IS POSSIBLE THAT A FEW SHOWERS COULD DEVELOP FOR THE EVENING HOURS...BUT FOR NOW WL LEAVE SILENT POPS IN THE FORECAST. THE NAM AND HRRR ARE STILL SHOWING A DECREASE IN LOW LEVEL CLOUD COVER LATER THIS AFTERNOON AND EARLY THIS EVENING...BUT NOT SEEING ANY EVIDENCE OF THIS IN THE SATELLITE IMAGES YET. BOTH MODELS THEN SHOW THE POTENTIAL FOR LOW CLOUD REFORMING OVR PORTIONS OF THE PLAINS BY LATE EVENING. OVERNIGHT LOW TEMPS ARE EXPECTED TO BE IN THE UPPER 30S TO LOWER 40S OVR THE SERN PLAINS...THE COLDEST AREAS LOOK TO BE NORTHERN PORTIONS OF PUEBLO COUNTY...EL PASO AND CROWLEY COUNTIES. LOWS IN THESE LOCATIONS LOOK LIKE THEY WL BE IN THE LOWER 30S. HAVE DECIDED TO ISSUE A FROST ADVISORY FOR THESE COUNTIES JUST IN CASE THERE ARE POCKETS OF FROST. MODELS ARE INDICATING THAT THE LOW CLOUDS SHOULD DISSIPATE BY LATE MORNING ON SATURDAY WITH A GOOD WARM UP IN STORE. HIGHS ON SAT OVR THE SERN PLAINS SHOULD BE IN THE 70S...WITH MID TO UPPER 70S IN THE SAN LUIS VALLEY. GENERALLY DRY WESTERLY FLOW ALOFT IS EXPECTED OVR THE FORECAST AREA. THE NAM AGAIN PRINTS OUT SOME LIGHT PCPN OVR THE SRN CO MTNS AND SAN LUIS VALLEY SAT AFTERNOON...SO WL LEAVE SOME ISOLD POPS IN THE FORECAST FOR THE SW MTNS AND THE SANGRES. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 242 PM MDT FRI SEP 12 2014 MODELS IN GOOD AGREEMENT THROUGH THE EXTENDED PERIOD WITH SMALL ENSEMBLE SPREADS AND HIGHER FORECAST CONFIDENCE. SATURDAY NIGHT THROUGH SUNDAY NIGHT...FLAT ZONAL WESTERLY FLOW WILL PERSIST ACROSS COLORADO THROUGH THIS PERIOD AS AN UPPER RIDGE BEGINS TO BUILD ALONG THE WEST COAST AND SHORTWAVE TROUGH DROPS SOUTH OUT OF CANADA INTO THE NORTHERN PLAINS. EXPECT ISOLATED SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS ON SATURDAY EVENING TO DISSIPATE AROUND SUNDOWN WITH LOSS OF DAYTIME INSTABILITY. OVERNIGHT LOWS WILL FALL INTO THE MID TO UPPER 40S FOR MUCH OF THE REGION. A WEAK DISTURBANCE EMBEDDED IN THE WESTERLY FLOW ALOFT WILL MOVE ACROSS THE STATE ON SUNDAY AFTERNOON. ANOTHER ROUND OF ISOLATED TO SCATTERED MOUNTAIN SHOWERS AND THUNDERSTORMS ARE EXPECTED...WHICH SHOULD DISSIPATE ON SUNDAY EVENING. HIGHS SUNDAY WILL REACH INTO THE 80S FOR THE LOWER ELEVATIONS. MONDAY AND MONDAY NIGHT...MODELS IN GOOD AGREEMENT WITH A STRONG COLD FRONT DROPPING SOUTH ACROSS THE EASTERN PLAINS ON MONDAY MORNING. THE NAM IS THE FASTEST SOLUTION...WITH IT CLEARING SOUTH INTO NEW MEXICO BY 12Z...WHILE THE ECMWF AND GFS ARE ABOUT 6 HOURS SLOWER. FEEL THAT A BIT FASTER SOLUTIONS WILL LIKELY PLAY OUT AND FOLLOWED THE NAM FRONTAL PROGRESSION. EXPECT LOW LEVEL FLOW TO TURN EASTERLY AND USHER IN MUCH COOLER AIR INTO THE PLAINS. UPGLIDE AND MOISTURE BEHIND THE FRONT WILL LIKELY LEAD TO LIGHT RAIN FOR THE PLAINS THROUGH MONDAY AFTERNOON. WARMER TEMPERATURES AND GREATER INSTABILITY WILL EXIST OVER THE MOUNTAIN AREAS MONDAY AFTERNOON AND SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED. MODELS IN AGREEMENT WITH THE LIGHT RAIN COMING TO AN END FOR THE PLAINS FROM NORTH TO SOUTH THROUGH THE AFTERNOON HOURS. EXPECT THUNDERSTORMS OVER THE MOUNTAINS TO DISSIPATE AFTER SUNSET. TEMPERATURES WILL BE MUCH COOLER BEHIND THE FRONT WITH THE PLAINS LIKELY ONLY SEEING 60S FOR HIGHS. TUESDAY THROUGH FRIDAY...THE UPPER PATTERN WILL BECOME AMPLIFIED ACROSS THE CONUS WITH HIGH PRESSURE BUILDING OVER THE WEST AND A TROUGH OVER THE EASTERN STATES. THIS WILL PUT SOUTHERN COLORADO UNDER BROAD NORTHWEST FLOW. EXPECT GENERALLY DRY CONDITIONS ACROSS THE REGION WITH DAILY AFTERNOON AND EVENING MOUNTAIN CONVECTION POSSIBLE. TEMPERATURES WILL BE QUICK TO WARM UP WITH 80S FOR THE LOWER ELEVATIONS THROUGH THE MIDDLE OF THE WEEK. BY FRIDAY MODELS ARE BRINGING A PIECE OF ENERGY FROM TROPICAL STORM ODILE WHICH IS FORECAST TO BE OFF THE NORTHERN BAJA COAST BY FRIDAY. IF THIS DISTURBANCE AND MOISTURE DOES MATERIALIZE...THERE WILL BE MUCH BETTER CHANCES FOR PRECIPITATION...ESPECIALLY ALONG THE CONTINENTAL DIVIDE...BY FRIDAY. THIS WILL NEED TO BE MONITORED. MOZLEY && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 522 PM MDT FRI SEP 12 2014 LATEST GUIDANCE KEEPS KCOS AND KPUB SOCKED IN FOR TONIGHT AND HAVE ADJUSTED TAFS ACCORDINGLY. GUIDANCE LOOKS REASONABLE...ESPECIALLY FOR KCOS...AS SOUTHERLY WINDS ARE PROJECTED TO OCCUR THROUGHOUT THE NIGHT TIME HOURS. && .PUB WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY FROM 1 AM TO 8 AM MDT SATURDAY FOR COZ084>086-089. && $$ UPDATE...HODANISH SHORT TERM...28 LONG TERM...MOZLEY AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
526 PM MDT FRI SEP 12 2014 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 242 PM MDT FRI SEP 12 2014 WIDESPREAD LOW CLOUDS CONTINUE TO COVER THE SERN CO PLAINS THIS AFTERNOON...WITH TEMPS IN THE 40S. THE REST OF THE FORECAST AREA HAS HAD MOSTLY SUNNY SKIES...WITH SOME CONVECTIVE CLOUDS DEVELOPING OVER THE SRN MTNS AND SAN LUIS VALLEY. THERE CONTINUES TO BE SOME SPOTTY LIGHT DRIZZLE IN LOCATIONS NR THE ERN MTNS. THE NAM HAS WAY OVERDONE THE PCPN OVR THE SERN PLAINS FOR TODAY...WITH THE HRRR BEING MORE REASONABLE. FOR THIS EVENING AND OVERNIGHT THE NAM PRINTS OUT SOME ISOLD PCPN OVR THE SRN CO MTNS. THE HRRR IS DRY FOR THIS EVENING. IT IS POSSIBLE THAT A FEW SHOWERS COULD DEVELOP FOR THE EVENING HOURS...BUT FOR NOW WL LEAVE SILENT POPS IN THE FORECAST. THE NAM AND HRRR ARE STILL SHOWING A DECREASE IN LOW LEVEL CLOUD COVER LATER THIS AFTERNOON AND EARLY THIS EVENING...BUT NOT SEEING ANY EVIDENCE OF THIS IN THE SATELLITE IMAGES YET. BOTH MODELS THEN SHOW THE POTENTIAL FOR LOW CLOUD REFORMING OVR PORTIONS OF THE PLAINS BY LATE EVENING. OVERNIGHT LOW TEMPS ARE EXPECTED TO BE IN THE UPPER 30S TO LOWER 40S OVR THE SERN PLAINS...THE COLDEST AREAS LOOK TO BE NORTHERN PORTIONS OF PUEBLO COUNTY...EL PASO AND CROWLEY COUNTIES. LOWS IN THESE LOCATIONS LOOK LIKE THEY WL BE IN THE LOWER 30S. HAVE DECIDED TO ISSUE A FROST ADVISORY FOR THESE COUNTIES JUST IN CASE THERE ARE POCKETS OF FROST. MODELS ARE INDICATING THAT THE LOW CLOUDS SHOULD DISSIPATE BY LATE MORNING ON SATURDAY WITH A GOOD WARM UP IN STORE. HIGHS ON SAT OVR THE SERN PLAINS SHOULD BE IN THE 70S...WITH MID TO UPPER 70S IN THE SAN LUIS VALLEY. GENERALLY DRY WESTERLY FLOW ALOFT IS EXPECTED OVR THE FORECAST AREA. THE NAM AGAIN PRINTS OUT SOME LIGHT PCPN OVR THE SRN CO MTNS AND SAN LUIS VALLEY SAT AFTERNOON...SO WL LEAVE SOME ISOLD POPS IN THE FORECAST FOR THE SW MTNS AND THE SANGRES. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 242 PM MDT FRI SEP 12 2014 MODELS IN GOOD AGREEMENT THROUGH THE EXTENDED PERIOD WITH SMALL ENSEMBLE SPREADS AND HIGHER FORECAST CONFIDENCE. SATURDAY NIGHT THROUGH SUNDAY NIGHT...FLAT ZONAL WESTERLY FLOW WILL PERSIST ACROSS COLORADO THROUGH THIS PERIOD AS AN UPPER RIDGE BEGINS TO BUILD ALONG THE WEST COAST AND SHORTWAVE TROUGH DROPS SOUTH OUT OF CANADA INTO THE NORTHERN PLAINS. EXPECT ISOLATED SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS ON SATURDAY EVENING TO DISSIPATE AROUND SUNDOWN WITH LOSS OF DAYTIME INSTABILITY. OVERNIGHT LOWS WILL FALL INTO THE MID TO UPPER 40S FOR MUCH OF THE REGION. A WEAK DISTURBANCE EMBEDDED IN THE WESTERLY FLOW ALOFT WILL MOVE ACROSS THE STATE ON SUNDAY AFTERNOON. ANOTHER ROUND OF ISOLATED TO SCATTERED MOUNTAIN SHOWERS AND THUNDERSTORMS ARE EXPECTED...WHICH SHOULD DISSIPATE ON SUNDAY EVENING. HIGHS SUNDAY WILL REACH INTO THE 80S FOR THE LOWER ELEVATIONS. MONDAY AND MONDAY NIGHT...MODELS IN GOOD AGREEMENT WITH A STRONG COLD FRONT DROPPING SOUTH ACROSS THE EASTERN PLAINS ON MONDAY MORNING. THE NAM IS THE FASTEST SOLUTION...WITH IT CLEARING SOUTH INTO NEW MEXICO BY 12Z...WHILE THE ECMWF AND GFS ARE ABOUT 6 HOURS SLOWER. FEEL THAT A BIT FASTER SOLUTIONS WILL LIKELY PLAY OUT AND FOLLOWED THE NAM FRONTAL PROGRESSION. EXPECT LOW LEVEL FLOW TO TURN EASTERLY AND USHER IN MUCH COOLER AIR INTO THE PLAINS. UPGLIDE AND MOISTURE BEHIND THE FRONT WILL LIKELY LEAD TO LIGHT RAIN FOR THE PLAINS THROUGH MONDAY AFTERNOON. WARMER TEMPERATURES AND GREATER INSTABILITY WILL EXIST OVER THE MOUNTAIN AREAS MONDAY AFTERNOON AND SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED. MODELS IN AGREEMENT WITH THE LIGHT RAIN COMING TO AN END FOR THE PLAINS FROM NORTH TO SOUTH THROUGH THE AFTERNOON HOURS. EXPECT THUNDERSTORMS OVER THE MOUNTAINS TO DISSIPATE AFTER SUNSET. TEMPERATURES WILL BE MUCH COOLER BEHIND THE FRONT WITH THE PLAINS LIKELY ONLY SEEING 60S FOR HIGHS. TUESDAY THROUGH FRIDAY...THE UPPER PATTERN WILL BECOME AMPLIFIED ACROSS THE CONUS WITH HIGH PRESSURE BUILDING OVER THE WEST AND A TROUGH OVER THE EASTERN STATES. THIS WILL PUT SOUTHERN COLORADO UNDER BROAD NORTHWEST FLOW. EXPECT GENERALLY DRY CONDITIONS ACROSS THE REGION WITH DAILY AFTERNOON AND EVENING MOUNTAIN CONVECTION POSSIBLE. TEMPERATURES WILL BE QUICK TO WARM UP WITH 80S FOR THE LOWER ELEVATIONS THROUGH THE MIDDLE OF THE WEEK. BY FRIDAY MODELS ARE BRINGING A PIECE OF ENERGY FROM TROPICAL STORM ODILE WHICH IS FORECAST TO BE OFF THE NORTHERN BAJA COAST BY FRIDAY. IF THIS DISTURBANCE AND MOISTURE DOES MATERIALIZE...THERE WILL BE MUCH BETTER CHANCES FOR PRECIPITATION...ESPECIALLY ALONG THE CONTINENTAL DIVIDE...BY FRIDAY. THIS WILL NEED TO BE MONITORED. MOZLEY && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 522 PM MDT FRI SEP 12 2014 LATEST GUIDANCE KEEPS KCOS AND KPUB SOCKED IN FOR TONIGHT AND HAVE ADJUSTED TAFS ACCORDINGLY. GUIDANCE LOOKS REASONABLE...ESPECIALLY FOR KCOS...AS SOUTHERLY WINDS ARE PROJECTED TO OCCUR THROUGHOUT THE NIGHT TIME HOURS. && .PUB WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY FROM 1 AM TO 8 AM MDT SATURDAY FOR COZ084>086-089. && $$ SHORT TERM...28 LONG TERM...MOZLEY AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS ALBANY NY
736 AM EDT THU SEP 11 2014 .SYNOPSIS... LOW PRESSURE IN EASTERN CANADA WILL DRIVE A COLD FRONT ACROSS THE REGION THIS AFTERNOON. AHEAD OF THIS FRONT WILL BE SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM...MAINLY SOUTH OF ALBANY. BEHIND THIS FRONT WILL COME THE COOLEST AIR MASS SINCE LATE MAY BY FRIDAY. A DISTURBANCE MIGHT BRING A ROUND OF SHOWERS ON SATURDAY FOLLOWED BY MORE COOL DRY WEATHER SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 630 AM EDT...SCATTERED MAINLY LIGHT SHOWERS WERE WORKING INTO MUCH OF THE AREA. THIS BATCH WILL LEAVE BUT OTHERS WILL THROUGHOUT THE DAY. LOW PRESSURE WAS WORKING THROUGH SOUTHERN ONTARIO DRAGGING AA COLD FRONT INTO WESTERN NEW YORK. FOR THIS UPDATE...JUST INCREASED HOURLY POPS A BIT THIS MORNING (DUE TO THE SCATTERED SHOWERS MOVING QUICKLY EAST). OTHERWISE VERY LITTLE TO TWEAK OTHER THAN THAT. THE LATEST RUC13 INDICATED LITTLE OR NO INSTABILITY SO WE KEPT ANY MENTION OF THUNDER OUT OF THE FORECAST THROUGH EARLY MORNING. TEMPERATURES WERE QUITE MILD DUE TO AN INCREASE IN CLOUDS...AND A PERSISTENT SOUTHERLY BREEZE ON THE WARM SIDE OF THE LOW PRESSURE...HOLDING MAINLY IN THE 60S. THE AFOREMENTIONED COLD FRONT ASSOCIATED WITH THE LOW PRESSURE WILL MOVE STEADILY ALONG AND WORK INTO THE SOUTHERN ADIRONDACKS AND THE MOHAWK VALLEY EARLY THIS AFTERNOON...THE CAPITAL REGION AND SURROUNDING AREAS LATE AFTERNOON...AND THE MID HUDSON VALLEY AND NORTHWESTERN CONNECTICUT BY EARLY EVENING. DUE TO VERY LIMITED INSTABILITY WE ONLY MENTION A SLIGHT CHANCE OF THUNDERSTORM FROM THE CAPITAL REGION NORTHWARD. FURTHER SOUTH...WITH A LITTLE MORE INSTABILITY...WE DID MENTION A CHANCE OF THUNDERSTORMS. IT IS REMOTELY POSSIBLE THAT ANY THUNDERSTORM IN THIS AREA COULD CONTAIN SOME GUSTY WINDS AS THE OVERALL WIND FIELD (BULK SHEAR) INCREASES TO ABOUT 35-40KTS. HOWEVER...THE THREAT APPEARED LOW ENOUGH NOT TO MENTION IN THE GRIDS OR CERTAINLY ENHANCED WORDING AT THIS TIME. PWAT VALUES LOOK TO INCREASE TO ABOUT 2 INCHES...BUT THIS LOOKS TO HAPPEN THIS MORNING. THE H20 WATER VAPOR LOOP ALREADY INDICATED A MID LEVEL DRY PUNCH QUICKLY WORKING INTO WESTERN NEW YORK STATE. THIS DRY PUNCH WILL ALLOW PWATS TO DROP QUICKLY THIS AFTERNOON...EVEN AHEAD OF THE FRONT. THEREFORE THE BEST FORCING (WHICH IS GOING TO WELL NORTH)...WILL NOT LINE UP WITH THE BEST PWATS AND PASSAGE OF THE COLD FRONT. THERE WILL BE PLENTY OF CLOUDS TODAY WITH PERHAPS A FEW BREAKS OF AFTERNOON SUNSHINE. EVEN SO...TEMPERATURES COULD SPIKE A LITTLE AHEAD OF THE FRONT. WE EXPECT HIGHS NEAR 80 IN THE MID HUDSON VALLEY AND LOWER LITCHFIELD COUNTY...UPPER 70S AROUND ALBANY. FURTHER NORTH AND WEST WHERE THE COLD FRONT WILL BE FIRST TO COME THROUGH...HIGH TEMPERATURES WILL BE HELD TO BETWEEN THE UPPER 60S TO MID 70S. A GUSTY SOUTH WIND PREVAIL TODAY 10 TO 20 MPH...SHIFTING TO THE WEST BY LATE IN THE DAY ONCE THE COLD FRONT MOVES THROUGH. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... THE COLD FRONT WILL BE FINISHING ITS SWEEP THROUGH OUR AREA THIS EVENING TAKING ANY LEFTOVER SHOWERS WITH IT. THEN...A COOL CANADIAN AIR MASS WILL BE USHERED IN TONIGHT ON SOMEWHAT GUSTY NORTH OR NORTHWEST WINDS. THE SKY WILL CLEAR AND TEMPERATURES WILL DIP DOWN TO AROUND 50 FROM ALBANY SOUTH AND EAST. FURTHER NORTHWEST AND WEST...THEY WILL DIVE INTO THE 40S...AND EVEN TOUCH THE UPPER 30S ACROSS OUR ADIRONDACKS. FRIDAY LOOKS TO FEATURE A GOOD DEAL OF SUNSHINE (MIXING WITH FAIR WEATHER STRATO-CUMULUS) AND TEMPERATURES BELOW NORMAL. H850 TEMPERATURES LOOK TO DROP TO BETWEEN +5C NORTHWEST TO +9C SOUTHEAST ACROSS OUR REGION. THIS WILL TRANSLATE TO HIGH TEMPERATURES MAINLY IN THE 60S THROUGH OUR REGION...PERHAPS TOUCHING 70 FROM POUGHKEEPSIE...BUT ONLY 50S ACROSS THE ELEVATED TERRAIN NORTH OF ALBANY...MAKING IT FEEL AUTUMNAL. HIGH PRESSURE WILL CREST NORTH OF THE REGION EARLY FRIDAY NIGHT BEFORE RETREATING TO THE CANADIAN MARITIMES. A COOL NIGHT IS IN STORE BUT NOT AS COOL AS WOULD HAVE BEEN. WHILE THE NIGHT WILL START CLEAR...CLOUDS SHOULD INCREASE DUE TO WARM AIR ADVECTION AS A POTENT DISTURBANCE APPROACHES FROM THE OHIO VALLEY. OVERNIGHT LOWS WILL RANGE FROM THE UPPER 40S SOUTHEAST OF ALBANY...DOWN TO THE UPPER 30S ACROSS THE ADIRONDACKS. IF IT WERE TO GET ANY COLDER THERE...SOME FROST WOULD BE POSSIBLE. WE WILL MONITOR THAT POTENTIAL BUT FOR NOW...WE ARE FORECASTING TEMPERATURES TO REMAIN JUST ABOVE THE FROST THRESHOLD. THEN ON SATURDAY...AS THE AFOREMENTIONED DISTURBANCE APPROACH...IT LOOKS AS OF SURFACE LOW PRESSURE WILL FORM AT THE TRIPLE POINT OF THE WARM FRONT/COLD FRONT INTERFACE TO OUR SOUTHEAST. AT THIS POINT SHOWERS APPEARS TO BE A GOOD BET. IF SURFACE LOW PRESSURE DEVELOPS EVEN QUICKER...WE WOULD BE LOOKING AT A STEADY RAIN. FOR NOW...WILL CALL IT SHOWERS...BUT EITHER WAY...SATURDAY LOOKS LIKE A CLOUDY...DAMP DAY WITH HIGHS RANGING ONLY FROM THE MID 50S NORTHWEST TO UPPER 60S SOUTHEAST OF ALBANY. THE DISTURBANCE LOOKS TO MOVE QUICKLY EAST SATURDAY NIGHT...FOLLOWED BY PARTIAL CLEAR AND ANOTHER CANADIAN HIGH PRESSURE BRINGING A RE-NEWED SHOT OF COOL BUT DRY TO CLOSE OUT THE WEEKEND. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... THE LONG TERM PORTION OF THE FORECAST WILL FEATURE A BROAD UPPER TROUGH ACROSS THE EASTERN 2/3RDS OF NOAM. THIS WILL KEEP TEMPERATURES A BIT BELOW NORMAL ALONG WITH NEAR TO BELOW NORMAL PRECIPITATION. THE NEXT APPRECIABLE CHANCE FOR WET WEATHER IS LATE MONDAY NIGHT INTO TUESDAY AS THE NEXT PV ANOMALY IS PROGGED TO TRACK ACROSS THE GREAT LAKES REGION AND NORTHEAST CONUS. QPF/S FROM THE GLOBAL MODELS DIFFER AS THE GFS IS THE MOST AGGRESSIVE /LESS QPF/ WITH TRACK OF THIS WAVE. MEANWHILE THE ECMWF CONTINUES TO SUGGEST A COASTAL WAVE DEVELOPMENT WHICH SLOWS DOWN THE FORWARD PROGRESS AND KEEPS THE PRECIP LINGER LONGER /AND HIGHER QPF/. THE GGEM IS FURTHER SOUTH WITH LIGHTER AMOUNTS AS MAIN WAVE MOVES OFF THE CAROLINA/VIRGINIA COAST. OTHERWISE...SURFACE HIGH PRESSURE WILL BE THE MAIN FEATURE. THE H850 MEAN TEMPERATURES ARE EXPECTED TO HOVER INTO THE MIDDLE SINGLE DIGITS WHICH WILL RESULT IN MAINLY 60S FOR VALLEY LOCATIONS AND OVERNIGHT LOWS INTO THE 40S. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... SCATTERED TO BROKEN LINE OF SHOWERS WILL MOVE ACROSS THE REGION THIS MORNING. CIGS UPSTREAM WERE MAINLY MVFR WITH AN OCCASIONAL HIGH END IFR. WILL MENTION PREDOMINANT MVFR CONDITIONS...ALTHOUGH BRIEF IFR WILL CIGS WILL BE POSSIBLE THIS MORNING. WINDS TOO HAVE BEEN A BIT GUSTY FROM THE SOUTHERLY DIRECTION AND HAVE INCREASED MAGNITUDES IN THIS SET OF TAFS. VIS HAS NOT SHOWN MUCH RESTRICTIONS AND WE WILL KEEP THE VALUES INTO VFR. FRONTAL PASSAGE WILL SIGNIFY AN END TO THE SHOWERS AND A WIND SHIFT TO THE WEST-NORTHWEST BY AFTERNOON. MAGNITUDES WILL REMAIN AROUND 10 KTS WITH AN OCCASIONAL GUST TO NEAR 20 KTS. CIGS WILL BE A CHALLENGE AS IT WILL BE BORDERLINE BETWEEN MVFR/VFR...ESPECIALLY FOR THE UPSLOPE CONDITIONS INTO KPSF. OUTLOOK... FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. SUNDAY TO MONDAY: NO OPERATIONAL IMPACT. NO SIG WX. MONDAY NIGHT TO TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. && .FIRE WEATHER... A COLD FRONT WILL CROSS THE REGION THIS AFTERNOON...BRINGING SOME SHOWERS AND PERHAPS A THUNDERSTORM...MAINLY SOUTH OF ALBANY. RAINFALL AMOUNTS WITH SHOWERS LOOK TO BE UP TO HALF AN INCH IN OUR NORTHWESTERN ZONES...AROUND A QUARTER INCH LOCALLY IN THE CAPITAL REGION...LESS THAN THAT FURTHER SOUTH. A SOUTH WIND WILL AVERAGE 10 TO 20 MPH TODAY...SHIFTING TO THE NORTHWEST BEHIND THE COLD FRONT. RH LEVELS WILL REMAIN ELEVATED THIS AFTERNOON...ONLY DROPPING INTO THE 60S. TONIGHT ALL THE SHOWERS WILL MOVE EAST FOLLOWED BY PARTIAL CLEARING. A NORTHWEST BREEZE MIGHT BE ENOUGH TO MITIGATE THE FORMATION OF MOST FOG. FRIDAY WILL BE A DRY DAY WITH TEMPERATURES A BIT BELOW NORMAL. RH VALUES BY AFTERNOON WILL BE IN THE 35-45 PERCENT RANGE. THE SURFACE WIND WILL BE NORTH TO NORTHWEST 5-15 MPH. THE NEXT CHANCE OF SHOWERS WILL BE ON SATURDAY. && .HYDROLOGY... NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED THE NEXT FIVE DAYS ENDING MONDAY. SHOWERS AND ANY THUNDERSTORMS TODAY WILL PRODUCE ONLY ABOUT HALF AN INCH OF AVERAGE BASIN RAINFALL IN OUR NORTHERN AREAS...ABOUT A QUARTER INCH OR LESS ALBANY SOUTHWARD. THIS RAIN WILL NOT INFLUENCE ANY OF OUR MAIN STEM RIVERS THROUGH OUT THE REGION. ANY THUNDERSTORM COULD CONTAIN LOCALLY HEAVY RAINFALL...WITH AMOUNTS CLOSER TO AN INCH...JUST ENOUGH TO PRODUCE SOME PONDING OF WATER IN A FEW SPOTS. DRY WEATHER WILL RETURN TONIGHT AFTER A POSSIBLE LEFTOVER EVENING SHOWERS. IT WILL BE DRY FRIDAY...BUT THERE IS A CHANCE OF SHOWERS ON SATURDAY WITH ANOTHER DISTURBANCE. THEN...DRY WEATHER RETURNS SUNDAY INTO EARLY NEXT WEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...HWJIV NEAR TERM...HWJIV SHORT TERM...HWJIV LONG TERM...BGM AVIATION...BGM/JPV FIRE WEATHER...HWJIV/WASULA HYDROLOGY...HWJIV/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
635 AM EDT THU SEP 11 2014 .SYNOPSIS... LOW PRESSURE IN EASTERN CANADA WILL DRIVE A COLD FRONT ACROSS THE REGION THIS AFTERNOON. AHEAD OF THIS FRONT WILL BE SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM...MAINLY SOUTH OF ALBANY. BEHIND THIS FRONT WILL COME THE COOLEST AIR MASS SINCE LATE MAY BY FRIDAY. A DISTURBANCE MIGHT BRING A ROUND OF SHOWERS ON SATURDAY FOLLOWED BY MORE COOL DRY WEATHER SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 630 AM EDT...SCATTERED MAINLY LIGHT SHOWERS WERE WORKING INTO MUCH OF THE AREA. THIS BATCH WILL LEAVE BUT OTHERS WILL THROUGHOUT THE DAY. LOW PRESSURE WAS WORKING THROUGH SOUTHERN ONTARIO DRAGGING AA COLD FRONT INTO WESTERN NEW YORK. FOR THIS UPDATE...JUST INCREASED HOURLY POPS A BIT THIS MORNING (DUE TO THE SCATTERED SHOWERS MOVING QUICKLY EAST). OTHERWISE VERY LITTLE TO TWEAK OTHER THAN THAT. THE LATEST RUC13 INDICATED LITTLE OR NO INSTABILITY SO WE KEPT ANY MENTION OF THUNDER OUT OF THE FORECAST THROUGH EARLY MORNING. TEMPERATURES WERE QUITE MILD DUE TO AN INCREASE IN CLOUDS...AND A PERSISTENT SOUTHERLY BREEZE ON THE WARM SIDE OF THE LOW PRESSURE...HOLDING MAINLY IN THE 60S. THE AFOREMENTIONED COLD FRONT ASSOCIATED WITH THE LOW PRESSURE WILL MOVE STEADILY ALONG AND WORK INTO THE SOUTHERN ADIRONDACKS AND THE MOHAWK VALLEY EARLY THIS AFTERNOON...THE CAPITAL REGION AND SURROUNDING AREAS LATE AFTERNOON...AND THE MID HUDSON VALLEY AND NORTHWESTERN CONNECTICUT BY EARLY EVENING. DUE TO VERY LIMITED INSTABILITY WE ONLY MENTION A SLIGHT CHANCE OF THUNDERSTORM FROM THE CAPITAL REGION NORTHWARD. FURTHER SOUTH...WITH A LITTLE MORE INSTABILITY...WE DID MENTION A CHANCE OF THUNDERSTORMS. IT IS REMOTELY POSSIBLE THAT ANY THUNDERSTORM IN THIS AREA COULD CONTAIN SOME GUSTY WINDS AS THE OVERALL WIND FIELD (BULK SHEAR) INCREASES TO ABOUT 35-40KTS. HOWEVER...THE THREAT APPEARED LOW ENOUGH NOT TO MENTION IN THE GRIDS OR CERTAINLY ENHANCED WORDING AT THIS TIME. PWAT VALUES LOOK TO INCREASE TO ABOUT 2 INCHES...BUT THIS LOOKS TO HAPPEN THIS MORNING. THE H20 WATER VAPOR LOOP ALREADY INDICATED A MID LEVEL DRY PUNCH QUICKLY WORKING INTO WESTERN NEW YORK STATE. THIS DRY PUNCH WILL ALLOW PWATS TO DROP QUICKLY THIS AFTERNOON...EVEN AHEAD OF THE FRONT. THEREFORE THE BEST FORCING (WHICH IS GOING TO WELL NORTH)...WILL NOT LINE UP WITH THE BEST PWATS AND PASSAGE OF THE COLD FRONT. THERE WILL BE PLENTY OF CLOUDS TODAY WITH PERHAPS A FEW BREAKS OF AFTERNOON SUNSHINE. EVEN SO...TEMPERATURES COULD SPIKE A LITTLE AHEAD OF THE FRONT. WE EXPECT HIGHS NEAR 80 IN THE MID HUDSON VALLEY AND LOWER LITCHFIELD COUNTY...UPPER 70S AROUND ALBANY. FURTHER NORTH AND WEST WHERE THE COLD FRONT WILL BE FIRST TO COME THROUGH...HIGH TEMPERATURES WILL BE HELD TO BETWEEN THE UPPER 60S TO MID 70S. A GUSTY SOUTH WIND PREVAIL TODAY 10 TO 20 MPH...SHIFTING TO THE WEST BY LATE IN THE DAY ONCE THE COLD FRONT MOVES THROUGH. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... THE COLD FRONT WILL BE FINISHING ITS SWEEP THROUGH OUR AREA THIS EVENING TAKING ANY LEFTOVER SHOWERS WITH IT. THEN...A COOL CANADIAN AIR MASS WILL BE USHERED IN TONIGHT ON SOMEWHAT GUSTY NORTH OR NORTHWEST WINDS. THE SKY WILL CLEAR AND TEMPERATURES WILL DIP DOWN TO AROUND 50 FROM ALBANY SOUTH AND EAST. FURTHER NORTHWEST AND WEST...THEY WILL DIVE INTO THE 40S...AND EVEN TOUCH THE UPPER 30S ACROSS OUR ADIRONDACKS. FRIDAY LOOKS TO FEATURE A GOOD DEAL OF SUNSHINE (MIXING WITH FAIR WEATHER STRATO-CUMULUS) AND TEMPERATURES BELOW NORMAL. H850 TEMPERATURES LOOK TO DROP TO BETWEEN +5C NORTHWEST TO +9C SOUTHEAST ACROSS OUR REGION. THIS WILL TRANSLATE TO HIGH TEMPERATURES MAINLY IN THE 60S THROUGH OUR REGION...PERHAPS TOUCHING 70 FROM POUGHKEEPSIE...BUT ONLY 50S ACROSS THE ELEVATED TERRAIN NORTH OF ALBANY...MAKING IT FEEL AUTUMNAL. HIGH PRESSURE WILL CREST NORTH OF THE REGION EARLY FRIDAY NIGHT BEFORE RETREATING TO THE CANADIAN MARITIMES. A COOL NIGHT IS IN STORE BUT NOT AS COOL AS WOULD HAVE BEEN. WHILE THE NIGHT WILL START CLEAR...CLOUDS SHOULD INCREASE DUE TO WARM AIR ADVECTION AS A POTENT DISTURBANCE APPROACHES FROM THE OHIO VALLEY. OVERNIGHT LOWS WILL RANGE FROM THE UPPER 40S SOUTHEAST OF ALBANY...DOWN TO THE UPPER 30S ACROSS THE ADIRONDACKS. IF IT WERE TO GET ANY COLDER THERE...SOME FROST WOULD BE POSSIBLE. WE WILL MONITOR THAT POTENTIAL BUT FOR NOW...WE ARE FORECASTING TEMPERATURES TO REMAIN JUST ABOVE THE FROST THRESHOLD. THEN ON SATURDAY...AS THE AFOREMENTIONED DISTURBANCE APPROACH...IT LOOKS AS OF SURFACE LOW PRESSURE WILL FORM AT THE TRIPLE POINT OF THE WARM FRONT/COLD FRONT INTERFACE TO OUR SOUTHEAST. AT THIS POINT SHOWERS APPEARS TO BE A GOOD BET. IF SURFACE LOW PRESSURE DEVELOPS EVEN QUICKER...WE WOULD BE LOOKING AT A STEADY RAIN. FOR NOW...WILL CALL IT SHOWERS...BUT EITHER WAY...SATURDAY LOOKS LIKE A CLOUDY...DAMP DAY WITH HIGHS RANGING ONLY FROM THE MID 50S NORTHWEST TO UPPER 60S SOUTHEAST OF ALBANY. THE DISTURBANCE LOOKS TO MOVE QUICKLY EAST SATURDAY NIGHT...FOLLOWED BY PARTIAL CLEAR AND ANOTHER CANADIAN HIGH PRESSURE BRINGING A RE-NEWED SHOT OF COOL BUT DRY TO CLOSE OUT THE WEEKEND. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... THE LONG TERM PORTION OF THE FORECAST WILL FEATURE A BROAD UPPER TROUGH ACROSS THE EASTERN 2/3RDS OF NOAM. THIS WILL KEEP TEMPERATURES A BIT BELOW NORMAL ALONG WITH NEAR TO BELOW NORMAL PRECIPITATION. THE NEXT APPRECIABLE CHANCE FOR WET WEATHER IS LATE MONDAY NIGHT INTO TUESDAY AS THE NEXT PV ANOMALY IS PROGGED TO TRACK ACROSS THE GREAT LAKES REGION AND NORTHEAST CONUS. QPF/S FROM THE GLOBAL MODELS DIFFER AS THE GFS IS THE MOST AGGRESSIVE /LESS QPF/ WITH TRACK OF THIS WAVE. MEANWHILE THE ECMWF CONTINUES TO SUGGEST A COASTAL WAVE DEVELOPMENT WHICH SLOWS DOWN THE FORWARD PROGRESS AND KEEPS THE PRECIP LINGER LONGER /AND HIGHER QPF/. THE GGEM IS FURTHER SOUTH WITH LIGHTER AMOUNTS AS MAIN WAVE MOVES OFF THE CAROLINA/VIRGINIA COAST. OTHERWISE...SURFACE HIGH PRESSURE WILL BE THE MAIN FEATURE. THE H850 MEAN TEMPERATURES ARE EXPECTED TO HOVER INTO THE MIDDLE SINGLE DIGITS WHICH WILL RESULT IN MAINLY 60S FOR VALLEY LOCATIONS AND OVERNIGHT LOWS INTO THE 40S. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... CLOUDS CONTINUE TO INCREASE...THICKEN AND LOWER ACROSS THE REGION WITH LATEST VIEW OF THE 11U-3.9U SATELLITE IMAGERY REVEALING THE EXPANDING LOW LEVEL STRATUS /MVFR CIGS/ FROM THE WEST-SOUTHWEST DIRECTION ADVECTING NORTHWARD. WE WILL THEREFORE PLACE AT LEAST MVFR FLIGHT RESTRICTIONS INTO THE TAF/S OVERNIGHT. AS FOR SHOWER POTENTIAL...UPSTREAM REGIONAL RADAR MOSAIC SHOWS THE LEADING EDGE OF THE PRECIP IS ERODING DUE TO THE DOWNSTREAM DRY AIRMASS IN PLACE. PER THE LATEST HRRR REFLECTIVITY...EXPECTATIONS ARE FOR THE SHOWER POTENTIAL TO INCREASE TOWARD SUNRISE AS THESE THOUGHTS ARE REFLECTED IN THE TAF/S. THE BEST TIME PERIOD FOR WET WEATHER APPEARS TO BE AROUND SUNRISE AND INTO THE MID MORNING HOURS ASSOCIATED WITH THE FRONTAL PASSAGE. AFTER FROPA...WINDS WILL SHIFT TOWARD THE WEST-NORTHWEST WITH A DRIER MID LEVELS. HOWEVER...LOWER LEVEL MOISTURE MAY LINGER AS WE WILL KEEP CIGS ON THE BORDER OF MVFR/VFR. WINDS WILL BE SOUTHERLY TO SOUTHEASTERLY AROUND 3-7 KT...BECOMING SOUTH AND INCREASING TO 5-10 KT BY 12Z THURSDAY. WINDS WILL SHIFT TO THE WEST-NORTHWEST AROUND 10KTS WITH SOME HIGHER GUSTS TOWARD 20KTS POSSIBLE BY AFTERNOON. OUTLOOK... THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA. SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. SUNDAY TO MONDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... A COLD FRONT WILL CROSS THE REGION THIS AFTERNOON...BRINGING SOME SHOWERS AND PERHAPS A THUNDERSTORM...MAINLY SOUTH OF ALBANY. RAINFALL AMOUNTS WITH SHOWERS LOOK TO BE UP TO HALF AN INCH IN OUR NORTHWESTERN ZONES...AROUND A QUARTER INCH LOCALLY IN THE CAPITAL REGION...LESS THAN THAT FURTHER SOUTH. A SOUTH WIND WILL AVERAGE 10 TO 20 MPH TODAY...SHIFTING TO THE NORTHWEST BEHIND THE COLD FRONT. RH LEVELS WILL REMAIN ELEVATED THIS AFTERNOON...ONLY DROPPING INTO THE 60S. TONIGHT ALL THE SHOWERS WILL MOVE EAST FOLLOWED BY PARTIAL CLEARING. A NORTHWEST BREEZE MIGHT BE ENOUGH TO MITIGATE THE FORMATION OF MOST FOG. FRIDAY WILL BE A DRY DAY WITH TEMPERATURES A BIT BELOW NORMAL. RH VALUES BY AFTERNOON WILL BE IN THE 35-45 PERCENT RANGE. THE SURFACE WIND WILL BE NORTH TO NORTHWEST 5-15 MPH. THE NEXT CHANCE OF SHOWERS WILL BE ON SATURDAY. && .HYDROLOGY... NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED THE NEXT FIVE DAYS ENDING MONDAY. SHOWERS AND ANY THUNDERSTORMS TODAY WILL PRODUCE ONLY ABOUT HALF AN INCH OF AVERAGE BASIN RAINFALL IN OUR NORTHERN AREAS...ABOUT A QUARTER INCH OR LESS ALBANY SOUTHWARD. THIS RAIN WILL NOT INFLUENCE ANY OF OUR MAIN STEM RIVERS THROUGH OUT THE REGION. ANY THUNDERSTORM COULD CONTAIN LOCALLY HEAVY RAINFALL...WITH AMOUNTS CLOSER TO AN INCH...JUST ENOUGH TO PRODUCE SOME PONDING OF WATER IN A FEW SPOTS. DRY WEATHER WILL RETURN TONIGHT AFTER A POSSIBLE LEFTOVER EVENING SHOWERS. IT WILL BE DRY FRIDAY...BUT THERE IS A CHANCE OF SHOWERS ON SATURDAY WITH ANOTHER DISTURBANCE. THEN...DRY WEATHER RETURNS SUNDAY INTO EARLY NEXT WEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...HWJIV NEAR TERM...HWJIV SHORT TERM...HWJIV LONG TERM...BGM AVIATION...BGM FIRE WEATHER...HWJIV/WASULA HYDROLOGY...HWJIV/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
445 AM EDT THU SEP 11 2014 .SYNOPSIS... LOW PRESSURE IN EASTERN CANADA WILL DRIVE A COLD FRONT ACROSS THE REGION LATER TODAY. AHEAD OF THIS FRONT WILL BE SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM...MAINLY SOUTH OF ALBANY. BEHIND THIS FRONT WILL COME THE COOLEST AIR MASS SINCE LATE MAY BY FRIDAY. A DISTURBANCE MIGHT BRING A ROUND OF SHOWERS ON SATURDAY FOLLOWED BY MORE COOL DRY WEATHER SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 445 AM EDT...A RATHER POTENT LOW PRESSURE AREA WAS JUST NORTH OF LAKE HURON. THIS STORM HAS A WINTRY LOOK TO IT IN THAT IT HAS A VERY WELL DEFINED AREA OF DEFORMATION RAIN ON ITS NORTHWEST SIDE...A COLD RAIN AT THAT...WITH POSSIBLY A LITTLE WET SNOW MIXING TO THE SOUTH OF JAMES IN CANADA. CLOSER TO HOME...RAIN SHOWERS WERE WORKING INTO OUR WESTERN AREAS TO THE WEST OF THE HUDSON RIVER VALLEY. SO FAR THERE HAS BEEN NO INDICATIONS OF THUNDERSTORMS WITH THIS FIRST LINE OF SHOWERS. THE LATEST RUC13 INDICATE LITTLE OR NO INSTABILITY SO WE KEPT ANY MENTION OF THUNDER OUT OF THE FORECAST THROUGH EARLY MORNING. TEMPERATURES WERE QUITE MILD DUE TO AN INCREASE IN CLOUDS...AND A PERSISTENT SOUTHERLY BREEZE ON THE WARM SIDE OF THE LOW PRESSURE...HOLDING MAINLY IN THE 60S. A COLD FRONT ASSOCIATED WITH THE LOW PRESSURE WAS WORKING INTO WESTERN NY STATE. THIS FRONT WILL MOVE STEADILY ALONG AND WORK INTO THE SOUTHERN ADIRONDACKS AND THE MOHAWK VALLEY EARLY THIS AFTERNOON...THE CAPITAL REGION AND SURROUNDING AREAS LATE AFTERNOON...AND THE MID HUDSON VALLEY AND NORTHWESTERN CONNECTICUT BY EARLY EVENING. MORE LINES OF SHOWERS CAN BE EXPECTED TODAY. DUE TO VERY LIMITED INSTABILITY WE ONLY MENTION A SLIGHT CHANCE OF THUNDERSTORM FROM THE CAPITAL REGION NORTHWARD. FURTHER SOUTH...WITH A LITTLE MORE INSTABILITY...WE DID MENTION A CHANCE OF THUNDERSTORMS. IT IS REMOTELY POSSIBLE THAT ANY THUNDERSTORM IN THIS AREA COULD CONTAIN SOME GUSTY WINDS AS THE OVERALL WIND FIELD (BULK SHEAR) INCREASES TO ABOUT 35-40KTS. HOWEVER...THE THREAT APPEARED LOW ENOUGH NOT TO MENTION IN THE GRIDS OR CERTAINLY ENHANCED WORDING AT THIS TIME. PWAT VALUES LOOK TO INCREASE TO ABOUT 2 INCHES...BUT THIS LOOKS TO HAPPEN THIS MORNING. THE H20 WATER VAPOR LOOP ALREADY INDICATED A MID LEVEL DRY PUNCH QUICKLY WORKING INTO WESTERN NEW YORK STATE. THIS DRY PUNCH WILL ALLOW PWATS TO DROP QUICKLY THIS AFTERNOON...EVEN AHEAD OF THE FRONT. THEREFORE THE BEST FORCING (WHICH IS GOING TO WELL NORTH)...WILL NOT LINE UP WITH THE BEST PWATS AND PASSAGE OF THE COLD FRONT. THERE WILL BE PLENTY OF CLOUDS TODAY WITH PERHAPS A FEW BREAKS OF AFTERNOON SUNSHINE. EVEN SO...TEMPERATURES COULD SPIKE A LITTLE AHEAD OF THE FRONT...AS THEY WERE ACTUALLY IN THE LOWER 70S IN SECTIONS OF CENTRAL NEW YORK! WE EXPECT HIGHS NEAR 80 IN THE MID HUDSON VALLEY AND LOWER LITCHFIELD COUNTY...UPPER 70S AROUND ALBANY. FURTHER NORTH AND WEST WHERE THE COLD FRONT WILL BE FIRST TO COME THROUGH...HIGH TEMPERATURES WILL BE HELD TO BETWEEN THE UPPER 60S TO MID 70S. A GUSTY SOUTH WIND PREVAIL TODAY 10 TO 20 MPH...SHIFTING TO THE WEST BY LATE IN THE DAY ONCE THE COLD FRONT MOVES THROUGH. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... THE COLD FRONT WILL BE FINISHING ITS SWEEP THROUGH OUR AREA THIS EVENING TAKING ANY LEFTOVER SHOWERS WITH IT. THEN...A COOL CANADIAN AIR MASS WILL BE USHERED IN TONIGHT ON SOMEWHAT GUSTY NORTH OR NORTHWEST WINDS. THE SKY WILL CLEAR AND TEMPERATURES WILL DIP DOWN TO AROUND 50 FROM ALBANY SOUTH AND EAST. FURTHER NORTHWEST AND WEST...THEY WILL DIVE INTO THE 40S...AND EVEN TOUCH THE UPPER 30S ACROSS OUR ADIRONDACKS. FRIDAY LOOKS TO FEATURE A GOOD DEAL OF SUNSHINE (MIXING WITH FAIR WEATHER STRATO-CUMULUS) AND TEMPERATURES BELOW NORMAL. H850 TEMPERATURES LOOK TO DROP TO BETWEEN +5C NORTHWEST TO +9C SOUTHEAST ACROSS OUR REGION. THIS WILL TRANSLATE TO HIGH TEMPERATURES MAINLY IN THE 60S THROUGH OUR REGION...PERHAPS TOUCHING 70 FROM POUGHKEEPSIE...BUT ONLY 50S ACROSS THE ELEVATED TERRAIN NORTH OF ALBANY...MAKING IT FEEL AUTUMNAL. HIGH PRESSURE WILL CREST NORTH OF THE REGION EARLY FRIDAY NIGHT BEFORE RETREATING TO THE CANADIAN MARITIMES. A COOL NIGHT IS IN STORE BUT NOT AS COOL AS WOULD HAVE BEEN. WHILE THE NIGHT WILL START CLEAR...CLOUDS SHOULD INCREASE DUE TO WARM AIR ADVECTION AS A POTENT DISTURBANCE APPROACHES FROM THE OHIO VALLEY. OVERNIGHT LOWS WILL RANGE FROM THE UPPER 40S SOUTHEAST OF ALBANY...DOWN TO THE UPPER 30S ACROSS THE ADIRONDACKS. IF IT WERE TO GET ANY COLDER THERE...SOME FROST WOULD BE POSSIBLE. WE WILL MONITOR THAT POTENTIAL BUT FOR NOW...WE ARE FORECASTING TEMPERATURES TO REMAIN JUST ABOVE THE FROST THRESHOLD. THEN ON SATURDAY...AS THE AFOREMENTIONED DISTURBANCE APPROACH...IT LOOKS AS OF SURFACE LOW PRESSURE WILL FORM AT THE TRIPLE POINT OF THE WARM FRONT/COLD FRONT INTERFACE TO OUR SOUTHEAST. AT THIS POINT SHOWERS APPEARS TO BE A GOOD BET. IF SURFACE LOW PRESSURE DEVELOPS EVEN QUICKER...WE WOULD BE LOOKING AT A STEADY RAIN. FOR NOW...WILL CALL IT SHOWERS...BUT EITHER WAY...SATURDAY LOOKS LIKE A CLOUDY...DAMP DAY WITH HIGHS RANGING ONLY FROM THE MID 50S NORTHWEST TO UPPER 60S SOUTHEAST OF ALBANY. THE DISTURBANCE LOOKS TO MOVE QUICKLY EAST SATURDAY NIGHT...FOLLOWED BY PARTIAL CLEAR AND ANOTHER CANADIAN HIGH PRESSURE BRINGING A RE-NEWED SHOT OF COOL BUT DRY TO CLOSE OUT THE WEEKEND. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... THE LONG TERM PORTION OF THE FORECAST WILL FEATURE A BROAD UPPER TROUGH ACROSS THE EASTERN 2/3RDS OF NOAM. THIS WILL KEEP TEMPERATURES A BIT BELOW NORMAL ALONG WITH NEAR TO BELOW NORMAL PRECIPITATION. THE NEXT APPRECIABLE CHANCE FOR WET WEATHER IS LATE MONDAY NIGHT INTO TUESDAY AS THE NEXT PV ANOMALY IS PROGGED TO TRACK ACROSS THE GREAT LAKES REGION AND NORTHEAST CONUS. QPF/S FROM THE GLOBAL MODELS DIFFER AS THE GFS IS THE MOST AGGRESSIVE /LESS QPF/ WITH TRACK OF THIS WAVE. MEANWHILE THE ECMWF CONTINUES TO SUGGEST A COASTAL WAVE DEVELOPMENT WHICH SLOWS DOWN THE FORWARD PROGRESS AND KEEPS THE PRECIP LINGER LONGER /AND HIGHER QPF/. THE GGEM IS FURTHER SOUTH WITH LIGHTER AMOUNTS AS MAIN WAVE MOVES OFF THE CAROLINA/VIRGINIA COAST. OTHERWISE...SURFACE HIGH PRESSURE WILL BE THE MAIN FEATURE. THE H850 MEAN TEMPERATURES ARE EXPECTED TO HOVER INTO THE MIDDLE SINGLE DIGITS WHICH WILL RESULT IN MAINLY 60S FOR VALLEY LOCATIONS AND OVERNIGHT LOWS INTO THE 40S. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... CLOUDS CONTINUE TO INCREASE...THICKEN AND LOWER ACROSS THE REGION WITH LATEST VIEW OF THE 11U-3.9U SATELLITE IMAGERY REVEALING THE EXPANDING LOW LEVEL STRATUS /MVFR CIGS/ FROM THE WEST-SOUTHWEST DIRECTION ADVECTING NORTHWARD. WE WILL THEREFORE PLACE AT LEAST MVFR FLIGHT RESTRICTIONS INTO THE TAF/S OVERNIGHT. AS FOR SHOWER POTENTIAL...UPSTREAM REGIONAL RADAR MOSAIC SHOWS THE LEADING EDGE OF THE PRECIP IS ERODING DUE TO THE DOWNSTREAM DRY AIRMASS IN PLACE. PER THE LATEST HRRR REFLECTIVITY...EXPECTATIONS ARE FOR THE SHOWER POTENTIAL TO INCREASE TOWARD SUNRISE AS THESE THOUGHTS ARE REFLECTED IN THE TAF/S. THE BEST TIME PERIOD FOR WET WEATHER APPEARS TO BE AROUND SUNRISE AND INTO THE MID MORNING HOURS ASSOCIATED WITH THE FRONTAL PASSAGE. AFTER FROPA...WINDS WILL SHIFT TOWARD THE WEST-NORTHWEST WITH A DRIER MID LEVELS. HOWEVER...LOWER LEVEL MOISTURE MAY LINGER AS WE WILL KEEP CIGS ON THE BORDER OF MVFR/VFR. WINDS WILL BE SOUTHERLY TO SOUTHEASTERLY AROUND 3-7 KT...BECOMING SOUTH AND INCREASING TO 5-10 KT BY 12Z THURSDAY. WINDS WILL SHIFT TO THE WEST-NORTHWEST AROUND 10KTS WITH SOME HIGHER GUSTS TOWARD 20KTS POSSIBLE BY AFTERNOON. OUTLOOK... THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA. SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. SUNDAY TO MONDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... A COLD FRONT WILL CROSS THE REGION THIS AFTERNOON...BRINGING SOME SHOWERS AND PERHAPS A THUNDERSTORM...MAINLY SOUTH OF ALBANY. RAINFALL AMOUNTS WITH SHOWERS LOOK TO BE UP TO HALF AN INCH IN OUR NORTHWESTERN ZONES...AROUND A QUARTER INCH LOCALLY IN THE CAPITAL REGION...LESS THAN THAT FURTHER SOUTH. A SOUTH WIND WILL AVERAGE 10 TO 20 MPH TODAY...SHIFTING TO THE NORTHWEST BEHIND THE COLD FRONT. RH LEVELS WILL REMAIN ELEVATED THIS AFTERNOON...ONLY DROPPING INTO THE 60S. TONIGHT ALL THE SHOWERS WILL MOVE EAST FOLLOWED BY PARTIAL CLEARING. A NORTHWEST BREEZE MIGHT BE ENOUGH TO MITIGATE THE FORMATION OF MOST FOG. FRIDAY WILL BE A DRY DAY WITH TEMPERATURES A BIT BELOW NORMAL. RH VALUES BY AFTERNOON WILL BE IN THE 35-45 PERCENT RANGE. THE SURFACE WIND WILL BE NORTH TO NORTHWEST 5-15 MPH. THE NEXT CHANCE OF SHOWERS WILL BE ON SATURDAY. && .HYDROLOGY... NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED THE NEXT FIVE DAYS ENDING MONDAY. SHOWERS AND ANY THUNDERSTORMS TODAY WILL PRODUCE ONLY ABOUT HALF AN INCH OF AVERAGE BASIN RAINFALL IN OUR NORTHERN AREAS...ABOUT A QUARTER INCH OR LESS ALBANY SOUTHWARD. THIS RAIN WILL NOT INFLUENCE ANY OF OUR MAIN STEM RIVERS THROUGH OUT THE REGION. ANY THUNDERSTORM COULD CONTAIN LOCALLY HEAVY RAINFALL...WITH AMOUNTS CLOSER TO AN INCH...JUST ENOUGH TO PRODUCE SOME PONDING OF WATER IN A FEW SPOTS. DRY WEATHER WILL RETURN TONIGHT AFTER A POSSIBLE LEFTOVER EVENING SHOWERS. IT WILL BE DRY FRIDAY...BUT THERE IS A CHANCE OF SHOWERS ON SATURDAY WITH ANOTHER DISTURBANCE. THEN...DRY WEATHER RETURNS SUNDAY INTO EARLY NEXT WEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...HWJIV NEAR TERM...HWJIV SHORT TERM...HWJIV LONG TERM...BGM AVIATION...BGM FIRE WEATHER...HWJIV/WASULA HYDROLOGY...HWJIV/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
130 AM EDT THU SEP 11 2014 .SYNOPSIS... LOW PRESSURE WILL MOVE INTO SOUTHEASTERN CANADA OVERNIGHT...AS A COLD FRONT APPROACHES THE REGION. THIS COLD FRONT WILL BRING SHOWERS AND ISOLATED THUNDERSTORMS TO SOME LOCATIONS THIS MORNING INTO THE AFTERNOON. HIGH PRESSURE WILL BRING COOL AND DRY WEATHER BACK INTO THE REGION THURSDAY NIGHT INTO EARLY SATURDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 100 AM EDT...CLOUDS CONTINUE TO SLOWLY GATHER OVER MOST OF THE REGION...WHILE STILL THIN AND ONLY PARTIAL IN SOUTHERN AREAS. RADARS INDICATED A FEW POSSIBLE SPRINKLES OVER NORTHERN AREAS...WHILE THE MORE SIGNIFICANT MEASURABLE SHOWERS HAVE YET TO WORK INTO OUR NORTHWESTERN AREAS. FOR THIS UPDATE...ONLY SLIGHT MODIFICATION OF THE HOURLY POPS AS MOST OF THE NEWEST GUIDANCE INDICATED SHOWERS WILL BE WORKING INTO THE CAPITAL REGION BY SUNRISE...TO INCREASED POPS A LITTLE. OTHERWISE ONLY VERY MINOR TINKERING OF THE REMAINDER OF THE HOURLY GRIDS. TEMPERATURES WILL BE MILDER THAN THE PREVIOUS FEW NIGHTS DUE TO THE LOW LEVEL WARM ADVECTION...LIGHT SOUTHERLY BREEZE...AND INCREASING CLOUDS. LOWS WILL GENERALLY BE IN THE MID AND U50S OVER THE MTNS...AND U50S TO L60S IN THE VALLEYS. && .SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...TOMORROW...THE TIMING/SPEED OF THE COLD FRONT HAS INCREASED ACCORDING TO THE LATEST NAM/CAN GGEM/ECMWF/GFS FOR AN EARLIER ONSET OF THE SHOWERS AND ISOLD THUNDERSTORMS SOUTH AND EAST OF THE CAPITAL REGION. THE THREAT FOR THUNDERSTORMS HAVE GREATLY DIMINISHED NORTH AND WEST OF THE CAPITAL REGION DUE TO LIMITED HEATING AHEAD OF THE FRONT...AND HENCE A LACK OF INSTABILITY. THE BEST L0W-LEVEL CONVERGENCE IS WITH THE FRONT...AND S/SW LLJ AT H850 INCREASES TO 40-50 KTS OR SO AROUND 12Z...AND CONTINUES AT 30-45 KTS IN THE AFTERNOON. POPS WERE INCREASED TO LIKELY VALUES IN THE LATE MORNING INTO THE AFTERNOON...ESPECIALLY FROM THE BERKSHIRES...CAPITAL REGION...AND NRN CATSKILLS...NORTH AND WEST. SOME OROGRAPHIC ENHANCEMENT IS POSSIBLE OVER THE SRN GREENS...AND WRN DACKS...AS THE BOUNDARY LAYER WINDS VEER TO THE WEST BY LUNCHTIME. MUCH OF THE HYDRO SERVICE AREA NEEDS SOME RAINFALL. THE CONVERGENCE WEAKENS A BIT SOUTH OF THE CAPITAL REGION...BUT AN ISOLD THUNDERSTORMS ARE POSSIBLE WITH SBCAPE VALUES OF 200-500 J/KG. A THREAT WAS CONTINUED THERE INTO THE EARLY EVENING. PWATS BRIEFLY SURGE TO 1.5-2.0" OR SO AHEAD OF THE FRONT...BUT THIS IS FOR A SHORT DURATION...SO LOCALLY HEAVY RAINFALL WAS REMOVED FROM THE GRIDS AT THIS TIME. HIGHS WILL GENERALLY BE IN THE U70S TO L80S FROM THE CAPITAL REGION...AND MOHAWK VALLEY SOUTH AND EAST...AND U60S T0 L70S NORTH AND WEST...EXCEPT MID OR UPPER 70S IN THE UPPER HUDSON VALLEY...AND PARTS OF THE CT RIVER VALLEY. THU NIGHT...THE FRONT SLIDES SOUTH AND EAST OF THE FCST AREA WITH THE ISOLD-SCT SHOWERS ENDING IN THE EARLY EVENING. STRONG LOW- LEVEL COLD ADVECTION OCCURS IN THE WAKE OF THE FRONT. H850 TEMPS FALL TO -4C TO -10C FROM ALY NORTH AND WEST...AND -10C TO -14C TO THE SOUTH AND EAST. THE SKIES WILL GRADUALLY CLEAR FROM NW TO SE...AND A N TO NW BREEZE OF 5-15 MPH WILL KEEP IT COOL. LOWS WILL BE IN THE U40S TO L50S SOUTH AND EAST OF THE CAPITAL DISTRICT /FEW MD 50S IN NW CT AND THE MID HUDSON VALLEY/...AND LOWER TO MID 40S NORTH AND WEST...AND EVEN A FEW U30S OVER THE SRN DACKS. FRI-FRI NIGHT...FAIR...COOL AND DRY WEATHER RETURNS TO THE FCST AREA...AS A LARGE DOME OF CANADIAN HIGH PRESSURE RIDGES IN FROM S-CNTRL CANADA...THE NRN PLAINS...AND GREAT LAKES REGION. MAX TEMPS WILL RUN ABOUT 5-10 DEGREES BELOW NORMAL WITH HIGHS MAINLY IN THE 60S. SOME U50S ARE POSSIBLE OVER THE SRN GREENS...SRN DACKS...AND ERN CATSKILLS. A FEW L70S ARE POSSIBLE OVER THE MID HUDSON VALLEY. A COOL NIGHT IS EXPECTED WITH PERHAPS SOME PATCHY FROST OVER THE SRN DACKS WITH TEMPS IN THE MID AND U30S. EXPECT LOWER TO M40S OVER A LARGE PORTION OF THE REST OF THE AREA. THE METMOS MINS WERE FAVORED HERE. SATURDAY...A SHORT-WAVE TROUGH...AND A WEAK COLD FRONT MAY INCREASE THE CLOUDS WITH A CHC OF SHOWERS IN THE AFTERNOON. TEMPS WILL BE A LITTLE MILDER THAN FRI WITH HIGHS IN THE 60S TO L70S. THE GFS AND ECMWF/CAN GGEM CONTINUE TO DISAGREE ON THE AMOUNT OF MOISTURE ASSOCIATED WITH THE SHORT-WAVE...WITH THE INTERNATIONAL GUIDANCE WETTER THAN THE GFS. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... THE LONG TERM PERIOD WILL BE CHARACTERIZED BY MAINLY DRY CONDITIONS AND HIGH PRESSURE EXCEPT FOR TWO WEAK DISTURBANCES PRODUCING SCATTERED SHOWERS ACROSS THE REGION SATURDAY NIGHT AND MONDAY NIGHT INTO TUESDAY. AT THE START OF THE LONG TERM PERIOD...A WEAK UPPER-LEVEL SHORTWAVE TROUGH WILL BE PROGRESSING ACROSS THE REGION SATURDAY NIGHT WITH LINGERING SHOWERS SATURDAY NIGHT ACROSS THE REGION. THESE SHOWERS ARE EXPECTED TO CLEAR THE REGION BY DAYBREAK SUNDAY AS HIGH PRESSURE BUILDS ACROSS THE REGION FOR THE REMAINDER OF THE WEEKEND WITH PARTLY CLOUDY SKIES AND DRY WEATHER. THIS AREA OF HIGH PRESSURE WILL MOVE ACROSS THE REGION MONDAY AS ANOTHER WEAK SHORTWAVE TROUGH/CLIPPER-TYPE SYSTEM APPROACHES FROM THE GREAT LAKES REGION MONDAY NIGHT. MOISTURE LOOKS TO BE LIMITED WITH THIS FEATURE BUT ENOUGH FORCING SHOULD BE PRESENT TO PROMOTE ISOLATED TO SCATTERED SHOWERS ACROSS THE REGION MONDAY NIGHT INTO TUESDAY. HIGH PRESSURE WILL BUILD ACROSS THE REGION THROUGH THE REMAINDER OF THE LONG TERM PERIOD WITH DRY CONDITIONS AND PARTLY CLOUDY SKIES. HIGH TEMPERATURES THROUGHOUT THE LONG TERM PERIOD WILL GENERALLY RANGE FROM THE UPPER 50S ACROSS THE HIGHER TERRAIN TO NEAR 70 IN VALLEY LOCATIONS. LOW TEMPERATURES WILL GENERALLY RANGE FROM THE LOW 40S TO NEAR 50...WITH UPPER 30S POSSIBLE ACROSS THE SOUTHERN ADIRONDACKS SUNDAY NIGHT. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... CLOUDS CONTINUE TO INCREASE...THICKEN AND LOWER ACROSS THE REGION WITH LATEST VIEW OF THE 11U-3.9U SATELLITE IMAGERY REVEALING THE EXPANDING LOW LEVEL STRATUS /MVFR CIGS/ FROM THE WEST-SOUTHWEST DIRECTION ADVECTING NORTHWARD. WE WILL THEREFORE PLACE AT LEAST MVFR FLIGHT RESTRICTIONS INTO THE TAF/S OVERNIGHT. AS FOR SHOWER POTENTIAL...UPSTREAM REGIONAL RADAR MOSAIC SHOWS THE LEADING EDGE OF THE PRECIP IS ERODING DUE TO THE DOWNSTREAM DRY AIRMASS IN PLACE. PER THE LATEST HRRR REFLECTIVITY...EXPECTATIONS ARE FOR THE SHOWER POTENTIAL TO INCREASE TOWARD SUNRISE AS THESE THOUGHTS ARE REFLECTED IN THE TAF/S. THE BEST TIME PERIOD FOR WET WEATHER APPEARS TO BE AROUND SUNRISE AND INTO THE MID MORNING HOURS ASSOCIATED WITH THE FRONTAL PASSAGE. AFTER FROPA...WINDS WILL SHIFT TOWARD THE WEST-NORTHWEST WITH A DRIER MID LEVELS. HOWEVER...LOWER LEVEL MOISTURE MAY LINGER AS WE WILL KEEP CIGS ON THE BORDER OF MVFR/VFR. WINDS WILL BE SOUTHERLY TO SOUTHEASTERLY AROUND 3-7 KT...BECOMING SOUTH AND INCREASING TO 5-10 KT BY 12Z THURSDAY. WINDS WILL SHIFT TO THE WEST-NORTHWEST AROUND 10KTS WITH SOME HIGHER GUSTS TOWARD 20KTS POSSIBLE BY AFTERNOON. OUTLOOK... THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA. SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. SUNDAY TO MONDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... LOW PRESSURE WILL MOVE INTO SOUTHEASTERN CANADA TONIGHT...AS A COLD FRONT APPROACHES THE REGION. THIS COLD FRONT WILL BRING SHOWERS AND ISOLATED THUNDERSTORMS TO SOME LOCATIONS TOMORROW MORNING INTO THE AFTERNOON. HIGH PRESSURE WILL BRING COOL AND DRY WEATHER BACK INTO THE REGION THURSDAY NIGHT INTO EARLY SATURDAY. THE RH VALUES WILL INCREASE TO 90 TO 100 PERCENT TONIGHT...THEN LOWER TO 50 TO 70 PERCENT TOMORROW AFTERNOON IN THE SHOWERS. EXPECT A NEAR FULL RECOVERY TO CLOSE TO 100 PERCENT FRIDAY MORNING. TOTAL RAINFALL AMOUNTS MAY RANGE FROM TWO TENTHS TO ONE HALF AN INCH FROM THE FRONT TOMORROW...WITH A FEW LOCALLY HIGHER AMOUNTS. THE WINDS WILL BE FROM THE SOUTH AT 10 MPH OR LESS TONIGHT...THEN INCREASE FROM THE SOUTH/SOUTHWEST AND SHIFT TO TO THE WEST AT 10 TO 20 MPH WITH A FEW GUSTS 30 TO 35 MPH DURING THE MID TO LATE AFTERNOON WITH THE FRONTAL PASSAGE. THE WINDS WILL VEER TO THE NORTHWEST OR NORTH AT 5 TO 10 MPH THU NIGHT. && .HYDROLOGY... NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED THE NEXT FIVE DAYS ENDING MONDAY. THE NEXT CHANCE OF SHOWERS AND ISOLD THUNDERSTORMS WILL BE TONIGHT THROUGH TOMORROW ASSOCIATED WITH A COLD FRONT PASSING THROUGH. AVERAGE BASIN RAINFALL LOOKS TO BE WELL UNDER AN INCH. HOWEVER...ANY THUNDERSTORM COULD CONTAIN HEAVY RAINFALL WITH LOCALIZED RAINFALL OF GREATER THAN A HALF AN INCH POSSIBLE. MOST LOCATIONS WILL GET TWO TENTHS TO LESS THAN A HALF AN INCH OF RAINFALL. PONDING OF WATER ON ROADS AND OTHER LOW LYING AREAS MAY OCCUR. AT THIS TIME...LITTLE OR NO RISES ARE EXPECTED ON MAIN STEM RIVERS. DRY WEATHER RETURNS ON FRIDAY BUT THERE IS A CHANCE OF SHOWERS ON SATURDAY WITH ANOTHER DISTURBANCE...AND DRY WEATHER RETURNS SUNDAY INTO EARLY NEXT WEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...HWJIV/WASULA NEAR TERM...HWJIV/NAS/WASULA SHORT TERM...WASULA LONG TERM...IRL AVIATION...BGM FIRE WEATHER...HWJIV/WASULA HYDROLOGY...HWJIV/WASULA WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS MIAMI FL
944 PM EDT FRI SEP 12 2014 .UPDATE... ONLY MADE SOME MINOR ADJUSTMENTS TO THE POP GRIDS THIS EVENING. COULD HAVE LOWERED THEM EVEN MORE THAN I DID, BUT THESE TROPICAL TYPE SMALL LOW LEVEL CIRCULATIONS CAN BEGIN TO DEVELOP CONVECTION AT ANY TIME GIVEN THE SOUTHEASTERLY FLOW ON THE EAST SIDE WITH DEEP TROPICAL AIRMASS. SO EVEN THOUGH NOT MUCH GOING ON AT THE CURRENT TIME, WAS A LITTLE HESITANT IN MAKING TOO DRASTIC OF A CUT IN THE POPS. THE HRRR KEEPS THE ACTION QUIET SO LATER UPDATES MAY BE NEEDED TO LOWER CHANCES MORE IF TRENDS DICTATE. KOB && .PREV DISCUSSION... /ISSUED 739 PM EDT FRI SEP 12 2014/ AVIATION... LOW PRESSURE CENTERED JUST NORTH OF NAPLES THIS EVENING WILL CONTINUE DRIFTING WEST INTO THE GULF OF MEXICO...BUT WILL BE THE MAJOR INFLUENCE ON SOUTH FLORIDA WEATHER THROUGH THE TAF PERIOD. APPEARS TSRA THREAT OVERNIGHT IS MINIMAL...SO ELECTED TO HAVE VCSH IN FORECAST INTO SATURDAY MORNING. BY 15Z...SCATTERED/NUMEROUS SHOWERS/TSTMS EXPECTED...HANDLED NOW BY VCTS BUT TEMPO GROUPS MAY BE NEEDED ONCE TIMING/COVERAGE BECOME MORE CERTAIN. ESE WINDS WILL DIMINISH TO 5 KTS OR LESS TONIGHT...THEN INCREASE TO 10-15 KTS BY SAT AFTN. PREV DISCUSSION... /ISSUED 344 PM EDT FRI SEP 12 2014/ DISCUSSION... RECENT WATER VAPOR IMAGERY AND THE LATEST GUIDANCE INDICATES AN UPPER LEVEL LOW JUST TO THE NORTH OF THE NORTHERN BAHAMAS AND IS FORECAST TO RETROGRADE WESTWARD TONIGHT INTO SATURDAY. ELEVATED CHANCES OF SHOWERS AND THUNDERSTORMS ARE FORECAST ACROSS THE REGION TONIGHT INTO SATURDAY. AS THE SURFACE LOW CONTINUES TO TRACK WESTWARD TONIGHT...IT IS FORECAST TO ENTER THE GULF WATERS WITH LOW LEVEL SOUTHEASTERLY WINDS FORECAST TO CONTINUE BRINGING IN DEEP TROPICAL MOISTURE INTO THE REGION TONIGHT INTO SATURDAY. FOR TONIGHT...THE AFOREMENTIONED UPPER LEVEL LOW IS FORECAST TO DRIFT WESTWARD WITH 500 HPA VORTICITY FORECAST TO PASS ACROSS THE REGION TONIGHT INTO SATURDAY. THUS THE INGREDIENTS FOR ADDITIONAL SHOWERS AND THUNDERSTORMS WILL CONTINUE TONIGHT INTO SATURDAY WITH ELEVATED POP`S INDICATED IN THE FORECAST. FOR SATURDAY...WILE THE UPPER LEVEL LOW MAY BE LESS OF A FACTOR AS IT IS FORECAST TO CONTINUE MOVING WESTWARD...THE SURFACE LOW IS FORECAST TO BE IN THE EASTERN GULF WITH LOW LEVEL SOUTHEASTERLY WINDS CONTINUING TO ADVECT ADDITIONAL DEEP MOISTURE INTO THE REGION. NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS ARE FORECAST FOR SATURDAY AFTERNOON AND EARLY EVENING HOURS. BY SUNDAY TROPICAL MOISTURE IS FORECAST TO REMAIN ACROSS THE REGION WITH DAY TIME HEATING LIKELY TO DEVELOP AFTERNOON SHOWERS AND THUNDERSTORMS. THE EXTENDED GUIDANCE INDICATES SOME RELATIVELY DRIER AIR ENTERING THE REGION EARLY NEXT WEEK. MARINE... WINDS ARE FORECAST TO BE FROM 10 TO 15 KNOTS THROUGH SATURDAY THEN DECREASING INTO SUNDAY TO AROUND 10 KNOTS. SEAS 2 TO 3 FEET POSSIBLE TODAY INTO SATURDAY THEN DECREASING TO 2 FEET OR LESS BY SUNDAY. && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS MIAMI FL
200 PM EDT THU SEP 11 2014 .AVIATION... LARGE SHIELD OF MODERATE TO HEAVY RAINFALL ASSOCIATED WITH MID LEVEL CIRCULATION JUST WEST OF THE BAHAMAS HAS REMAINED OFFSHORE THUS FAR THIS AFTERNOON. HOWEVER...CONVECTIVE BANDS EMANATING FROM THIS CIRCULATION CONTINUE TO PUSH INTO PALM BEACH COUNTY. LATEST HRRR AND OTHER HI-RES MODELS SEEM TO BE RETRACTING THEIR DEPICTION OF OVERALL COVERAGE OF HEAVY RAIN...BUT STILL SHOW A RATHER LARGE AREA OF SHOWERS PUSHING ACROSS THE EAST COAST SITES THROUGH 00Z AS THE CIRCULATION CENTER SLOWLY SLIDES TO THE WEST. THEREFORE PLACED TEMPOS IN AT ALL EAST COAST SITES FOR SHOWERS AND MVFR CIGS THROUGH 00Z. ISOLATED IFR CIGS/VSBYS ARE POSSIBLE WITHIN THE HEAVIEST SHOWERS BUT SHOULD BE BRIEF AND LEFT OUT OF TAFS FOR NOW. WINDS SHOULD BE LIGHT OVERNIGHT AND INTO THE MORNING HOURS TOMORROW BEFORE BECOMING ESE AGAIN TOMORROW AFTERNOON WITH THE CIRCULATION CENTER TO THE WEST OF THE EAST COAST SITES. && .PREV DISCUSSION... /ISSUED 1049 AM EDT THU SEP 11 2014/ UPDATE... ONLY SIGNIFICANT CHANGE TO THE FORECAST IS TO REDUCE POPS THIS MORNING AS THERE HAS BEEN SOME WEAK SUBSIDENCE AHEAD OF THE WEAK LOW OVER THE BAHAMAS. THE HRRR IS SHOWING THAT MOST CONVECTIVE DEVELOPMENT OVER THE MAINLAND WILL HOLD OFF UNTIL AFTER 18Z. EVEN THEN, MOST OF IT IS INDICATED TO BE OVER THE INTERIOR THIS AFTERNOON. THE MODEL DOES THEN BRING SHOWERS AND THUNDERSTORMS TO THE EASTERN COASTAL AREAS OF SOUTH FLORIDA THIS EVENING. THE ONLY THREAT OF CONCERN RIGHT NOW IS A LOW CHANCE OF URBAN FLOODING DUE TO SLOW MOVING HEAVY SHOWERS AND THUNDERSTORMS. PREV DISCUSSION... /ISSUED 450 AM EDT THU SEP 11 2014/ DISCUSSION... AN AREA OF LOW PRESSURE NEAR THE NORTHWEST BAHAMAS WILL DOMINATE THE WEATHER DISCUSSION OVER THE NEXT COUPLE DAYS. MODELS ARE IN GOOD AGREEMENT THAT THIS WEAK SYSTEM WILL MOVE SLOWLY WESTWARD ACROSS THE NORTHWEST BAHAMAS AND THEN ACROSS SOUTH FLORIDA ON FRIDAY. CONDITIONS ARE FORECAST TO BECOME UNFAVORABLE OVER THE LOW TODAY AS SHEAR INCREASES. HOWEVER...THERE IS STILL A SLIGHT CHANCE THAT THE SYSTEM MAY DEVELOP BEFORE MOVING INTO SOUTH FLORIDA...AND THEN A MEDIUM CHANCE AFTER IT MOVES INTO THE GULF OF MEXICO OVER THE WEEKEND. REGARDLESS OF DEVELOPMENT...THE MAIN IMPACT FOR SOUTH FLORIDA WILL LIKELY BE LOCALLY HEAVY RAINFALL. TODAY...THE WIND FIELD OVER/NEAR THE LOW IS LIGHT...AND WINDS ARE FORECAST TO BE VERY LIGHT ACROSS THE REGION TODAY. A LIGHT NORTHEASTERLY FLOW MAY BRIEFLY DEVELOP BEFORE SEA BREEZE BOUNDARIES BECOME DOMINANT. STORM MOTION IS FORECAST TO BE RELATIVELY SLOW TODAY...AND LOCALLY HEAVY RAINFALL IS POSSIBLE. PONDING IN POORLY DRAINED AREAS AND LOCALIZED STREET FLOODING ARE THE MAIN THREATS. RAIN CHANCES ARE 50-70% ACROSS THE REGION. THE LATEST HRRR RUN SHOWS PRETTY HIGH COVERAGE OF RAIN ACROSS THE REGION. HIGHS ARE FORECAST TO BE IN THE UPPER 80S TO AROUND 90 DEGREES. TONIGHT...THE WEAK AREA OF LOW PRESSURE WILL MOVE CLOSER TO THE EAST COAST...IN THE VICINITY OF PALM BEACH COUNTY COAST BY DAYBREAK. SCATTERED SHOWERS AND A FEW EMBEDDED STORMS ARE FORECAST FOR THE EAST COAST METRO AREAS OVERNIGHT. FRIDAY...THE AREA OF LOW PRESSURE IS FORECAST TO MOVE SLOWLY ACROSS THE REGION...AND SHOWERS AND STORMS ARE LIKELY THROUGHOUT THE DAY. LOCALLY HEAVY RAIN AND MINOR STREET FLOODING IS POSSIBLE. CLOUD COVER AND RAINFALL IS FORECAST TO KEEP TEMPS IN THE 80S. THE AREA OF LOW PRESSURE IS FORECAST TO MOVE SOUTHWEST INTO THE GULF OF MEXICO FRIDAY NIGHT...AND RAIN CHANCES WILL CONTINUE ACROSS COASTAL AREAS. SATURDAY AND SUNDAY...DEEP MOISTURE WILL REMAIN ACROSS SOUTH FLORIDA THROUGH THE WEEKEND. THE ECMWF KEEPS A TROUGH AXIS LINGERING OVER THE REGION EXTENDING TO THE EAST OF THE AREA OF LOW PRESSURE THROUGH SUNDAY. THE GFS MOVES THE SYSTEM QUICKLY WESTWARD ACROSS THE GULF...WITH A RETURN OF THE DEEP EAST TO SOUTHEAST FLOW OBSERVED OVER THE PAST SEVERAL DAYS ON SUNDAY AS THE RIDGE BUILDS WESTWARD ACROSS THE REGION. SO RAIN CHANCES WILL REMAIN IN THE LIKELY CATEGORY ON SATURDAY...AND THEN COME DOWN A LITTLE ON SUNDAY. HIGH PRESSURE WILL THEN BUILD ACROSS THE REGION EARLY NEXT WEEK...WITH A MORE TYPICAL EASTERLY FLOW RAINY SEASON PATTERN. MARINE... A WEAK AREA OF LOW PRESSURE NEAR THE NORTHERN BAHAMAS IS FORECAST TO PUSH SLOWLY WEST ACROSS THE LOCAL ATLANTIC WATERS TONIGHT AND THEN INTO THE GULF WATERS FRIDAY NIGHT. THE NHC IS MONITORING THIS DISTURBANCE...AND THIS COULD IMPACT THE FORECAST FOR FRIDAY AND INTO THE WEEKEND. LIGHT WINDS ARE FORECAST TODAY...WITH GENERALLY EAST TO SOUTHEAST WINDS FRIDAY THROUGH THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 75 86 76 87 / 40 60 20 60 FORT LAUDERDALE 76 88 77 88 / 40 60 30 70 MIAMI 75 86 77 88 / 30 70 30 60 NAPLES 74 89 75 90 / 30 60 30 70 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS MIAMI FL
1049 AM EDT THU SEP 11 2014 .UPDATE... ONLY SIGNIFICANT CHANGE TO THE FORECAST IS TO REDUCE POPS THIS MORNING AS THERE HAS BEEN SOME WEAK SUBSIDENCE AHEAD OF THE WEAK LOW OVER THE BAHAMAS. THE HRRR IS SHOWING THAT MOST CONVECTIVE DEVELOPMENT OVER THE MAINLAND WILL HOLD OFF UNTIL AFTER 18Z. EVEN THEN, MOST OF IT IS INDICATED TO BE OVER THE INTERIOR THIS AFTERNOON. THE MODEL DOES THEN BRING SHOWERS AND THUNDERSTORMS TO THE EASTERN COASTAL AREAS OF SOUTH FLORIDA THIS EVENING. THE ONLY THREAT OF CONCERN RIGHT NOW IS A LOW CHANCE OF URBAN FLOODING DUE TO SLOW MOVING HEAVY SHOWERS AND THUNDERSTORMS. && .PREV DISCUSSION... /ISSUED 850 AM EDT THU SEP 11 2014/ AVIATION... SHOWERS ARE LIKELY ALONG WITH A FEW THUNDERSTORMS ACROSS MUCH OF THE AREA TODAY AS AN AREA OF LOW PRESSURE ACROSS THE BAHAMAS PUSHES TO THE WEST. AS A RESULT...KEPT VCSH TRANSITIONING TO VCTS AND THEN BACK TO VCSH AFTER 02Z AT ALL EAST COAST SITES THROUGH THE PERIOD. WINDS WILL AGAIN BE GENERALLY EASTERLY AT ALL EAST COAST SITES WITH A GULF BREEZE AT KAPF. PREV DISCUSSION... /ISSUED 450 AM EDT THU SEP 11 2014/ DISCUSSION... AN AREA OF LOW PRESSURE NEAR THE NORTHWEST BAHAMAS WILL DOMINATE THE WEATHER DISCUSSION OVER THE NEXT COUPLE DAYS. MODELS ARE IN GOOD AGREEMENT THAT THIS WEAK SYSTEM WILL MOVE SLOWLY WESTWARD ACROSS THE NORTHWEST BAHAMAS AND THEN ACROSS SOUTH FLORIDA ON FRIDAY. CONDITIONS ARE FORECAST TO BECOME UNFAVORABLE OVER THE LOW TODAY AS SHEAR INCREASES. HOWEVER...THERE IS STILL A SLIGHT CHANCE THAT THE SYSTEM MAY DEVELOP BEFORE MOVING INTO SOUTH FLORIDA...AND THEN A MEDIUM CHANCE AFTER IT MOVES INTO THE GULF OF MEXICO OVER THE WEEKEND. REGARDLESS OF DEVELOPMENT...THE MAIN IMPACT FOR SOUTH FLORIDA WILL LIKELY BE LOCALLY HEAVY RAINFALL. TODAY...THE WIND FIELD OVER/NEAR THE LOW IS LIGHT...AND WINDS ARE FORECAST TO BE VERY LIGHT ACROSS THE REGION TODAY. A LIGHT NORTHEASTERLY FLOW MAY BRIEFLY DEVELOP BEFORE SEA BREEZE BOUNDARIES BECOME DOMINANT. STORM MOTION IS FORECAST TO BE RELATIVELY SLOW TODAY...AND LOCALLY HEAVY RAINFALL IS POSSIBLE. PONDING IN POORLY DRAINED AREAS AND LOCALIZED STREET FLOODING ARE THE MAIN THREATS. RAIN CHANCES ARE 50-70% ACROSS THE REGION. THE LATEST HRRR RUN SHOWS PRETTY HIGH COVERAGE OF RAIN ACROSS THE REGION. HIGHS ARE FORECAST TO BE IN THE UPPER 80S TO AROUND 90 DEGREES. TONIGHT...THE WEAK AREA OF LOW PRESSURE WILL MOVE CLOSER TO THE EAST COAST...IN THE VICINITY OF PALM BEACH COUNTY COAST BY DAYBREAK. SCATTERED SHOWERS AND A FEW EMBEDDED STORMS ARE FORECAST FOR THE EAST COAST METRO AREAS OVERNIGHT. FRIDAY...THE AREA OF LOW PRESSURE IS FORECAST TO MOVE SLOWLY ACROSS THE REGION...AND SHOWERS AND STORMS ARE LIKELY THROUGHOUT THE DAY. LOCALLY HEAVY RAIN AND MINOR STREET FLOODING IS POSSIBLE. CLOUD COVER AND RAINFALL IS FORECAST TO KEEP TEMPS IN THE 80S. THE AREA OF LOW PRESSURE IS FORECAST TO MOVE SOUTHWEST INTO THE GULF OF MEXICO FRIDAY NIGHT...AND RAIN CHANCES WILL CONTINUE ACROSS COASTAL AREAS. SATURDAY AND SUNDAY...DEEP MOISTURE WILL REMAIN ACROSS SOUTH FLORIDA THROUGH THE WEEKEND. THE ECMWF KEEPS A TROUGH AXIS LINGERING OVER THE REGION EXTENDING TO THE EAST OF THE AREA OF LOW PRESSURE THROUGH SUNDAY. THE GFS MOVES THE SYSTEM QUICKLY WESTWARD ACROSS THE GULF...WITH A RETURN OF THE DEEP EAST TO SOUTHEAST FLOW OBSERVED OVER THE PAST SEVERAL DAYS ON SUNDAY AS THE RIDGE BUILDS WESTWARD ACROSS THE REGION. SO RAIN CHANCES WILL REMAIN IN THE LIKELY CATEGORY ON SATURDAY...AND THEN COME DOWN A LITTLE ON SUNDAY. HIGH PRESSURE WILL THEN BUILD ACROSS THE REGION EARLY NEXT WEEK...WITH A MORE TYPICAL EASTERLY FLOW RAINY SEASON PATTERN. MARINE... A WEAK AREA OF LOW PRESSURE NEAR THE NORTHERN BAHAMAS IS FORECAST TO PUSH SLOWLY WEST ACROSS THE LOCAL ATLANTIC WATERS TONIGHT AND THEN INTO THE GULF WATERS FRIDAY NIGHT. THE NHC IS MONITORING THIS DISTURBANCE...AND THIS COULD IMPACT THE FORECAST FOR FRIDAY AND INTO THE WEEKEND. LIGHT WINDS ARE FORECAST TODAY...WITH GENERALLY EAST TO SOUTHEAST WINDS FRIDAY THROUGH THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 88 75 86 76 / 60 40 60 20 FORT LAUDERDALE 89 76 88 77 / 60 40 60 30 MIAMI 88 75 86 77 / 60 30 70 30 NAPLES 90 74 89 75 / 60 30 60 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...13/SI LONG TERM....84/AK
AREA FORECAST DISCUSSION
NWS MIAMI FL
850 AM EDT THU SEP 11 2014 .AVIATION... SHOWERS ARE LIKELY ALONG WITH A FEW THUNDERSTORMS ACROSS MUCH OF THE AREA TODAY AS AN AREA OF LOW PRESSURE ACROSS THE BAHAMAS PUSHES TO THE WEST. AS A RESULT...KEPT VCSH TRANSITIONING TO VCTS AND THEN BACK TO VCSH AFTER 02Z AT ALL EAST COAST SITES THROUGH THE PERIOD. WINDS WILL AGAIN BE GENERALLY EASTERLY AT ALL EAST COAST SITES WITH A GULF BREEZE AT KAPF. && .PREV DISCUSSION... /ISSUED 450 AM EDT THU SEP 11 2014/ DISCUSSION... AN AREA OF LOW PRESSURE NEAR THE NORTHWEST BAHAMAS WILL DOMINATE THE WEATHER DISCUSSION OVER THE NEXT COUPLE DAYS. MODELS ARE IN GOOD AGREEMENT THAT THIS WEAK SYSTEM WILL MOVE SLOWLY WESTWARD ACROSS THE NORTHWEST BAHAMAS AND THEN ACROSS SOUTH FLORIDA ON FRIDAY. CONDITIONS ARE FORECAST TO BECOME UNFAVORABLE OVER THE LOW TODAY AS SHEAR INCREASES. HOWEVER...THERE IS STILL A SLIGHT CHANCE THAT THE SYSTEM MAY DEVELOP BEFORE MOVING INTO SOUTH FLORIDA...AND THEN A MEDIUM CHANCE AFTER IT MOVES INTO THE GULF OF MEXICO OVER THE WEEKEND. REGARDLESS OF DEVELOPMENT...THE MAIN IMPACT FOR SOUTH FLORIDA WILL LIKELY BE LOCALLY HEAVY RAINFALL. TODAY...THE WIND FIELD OVER/NEAR THE LOW IS LIGHT...AND WINDS ARE FORECAST TO BE VERY LIGHT ACROSS THE REGION TODAY. A LIGHT NORTHEASTERLY FLOW MAY BRIEFLY DEVELOP BEFORE SEA BREEZE BOUNDARIES BECOME DOMINANT. STORM MOTION IS FORECAST TO BE RELATIVELY SLOW TODAY...AND LOCALLY HEAVY RAINFALL IS POSSIBLE. PONDING IN POORLY DRAINED AREAS AND LOCALIZED STREET FLOODING ARE THE MAIN THREATS. RAIN CHANCES ARE 50-70% ACROSS THE REGION. THE LATEST HRRR RUN SHOWS PRETTY HIGH COVERAGE OF RAIN ACROSS THE REGION. HIGHS ARE FORECAST TO BE IN THE UPPER 80S TO AROUND 90 DEGREES. TONIGHT...THE WEAK AREA OF LOW PRESSURE WILL MOVE CLOSER TO THE EAST COAST...IN THE VICINITY OF PALM BEACH COUNTY COAST BY DAYBREAK. SCATTERED SHOWERS AND A FEW EMBEDDED STORMS ARE FORECAST FOR THE EAST COAST METRO AREAS OVERNIGHT. FRIDAY...THE AREA OF LOW PRESSURE IS FORECAST TO MOVE SLOWLY ACROSS THE REGION...AND SHOWERS AND STORMS ARE LIKELY THROUGHOUT THE DAY. LOCALLY HEAVY RAIN AND MINOR STREET FLOODING IS POSSIBLE. CLOUD COVER AND RAINFALL IS FORECAST TO KEEP TEMPS IN THE 80S. THE AREA OF LOW PRESSURE IS FORECAST TO MOVE SOUTHWEST INTO THE GULF OF MEXICO FRIDAY NIGHT...AND RAIN CHANCES WILL CONTINUE ACROSS COASTAL AREAS. SATURDAY AND SUNDAY...DEEP MOISTURE WILL REMAIN ACROSS SOUTH FLORIDA THROUGH THE WEEKEND. THE ECMWF KEEPS A TROUGH AXIS LINGERING OVER THE REGION EXTENDING TO THE EAST OF THE AREA OF LOW PRESSURE THROUGH SUNDAY. THE GFS MOVES THE SYSTEM QUICKLY WESTWARD ACROSS THE GULF...WITH A RETURN OF THE DEEP EAST TO SOUTHEAST FLOW OBSERVED OVER THE PAST SEVERAL DAYS ON SUNDAY AS THE RIDGE BUILDS WESTWARD ACROSS THE REGION. SO RAIN CHANCES WILL REMAIN IN THE LIKELY CATEGORY ON SATURDAY...AND THEN COME DOWN A LITTLE ON SUNDAY. HIGH PRESSURE WILL THEN BUILD ACROSS THE REGION EARLY NEXT WEEK...WITH A MORE TYPICAL EASTERLY FLOW RAINY SEASON PATTERN. MARINE... A WEAK AREA OF LOW PRESSURE NEAR THE NORTHERN BAHAMAS IS FORECAST TO PUSH SLOWLY WEST ACROSS THE LOCAL ATLANTIC WATERS TONIGHT AND THEN INTO THE GULF WATERS FRIDAY NIGHT. THE NHC IS MONITORING THIS DISTURBANCE...AND THIS COULD IMPACT THE FORECAST FOR FRIDAY AND INTO THE WEEKEND. LIGHT WINDS ARE FORECAST TODAY...WITH GENERALLY EAST TO SOUTHEAST WINDS FRIDAY THROUGH THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 88 75 86 76 / 60 40 60 20 FORT LAUDERDALE 89 76 88 77 / 60 40 60 30 MIAMI 88 75 86 77 / 60 30 70 30 NAPLES 90 74 89 75 / 50 30 60 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS MIAMI FL
450 AM EDT THU SEP 11 2014 .DISCUSSION... AN AREA OF LOW PRESSURE NEAR THE NORTHWEST BAHAMAS WILL DOMINATE THE WEATHER DISCUSSION OVER THE NEXT COUPLE DAYS. MODELS ARE IN GOOD AGREEMENT THAT THIS WEAK SYSTEM WILL MOVE SLOWLY WESTWARD ACROSS THE NORTHWEST BAHAMAS AND THEN ACROSS SOUTH FLORIDA ON FRIDAY. CONDITIONS ARE FORECAST TO BECOME UNFAVORABLE OVER THE LOW TODAY AS SHEAR INCREASES. HOWEVER...THERE IS STILL A SLIGHT CHANCE THAT THE SYSTEM MAY DEVELOP BEFORE MOVING INTO SOUTH FLORIDA...AND THEN A MEDIUM CHANCE AFTER IT MOVES INTO THE GULF OF MEXICO OVER THE WEEKEND. REGARDLESS OF DEVELOPMENT...THE MAIN IMPACT FOR SOUTH FLORIDA WILL LIKELY BE LOCALLY HEAVY RAINFALL. TODAY...THE WIND FIELD OVER/NEAR THE LOW IS LIGHT...AND WINDS ARE FORECAST TO BE VERY LIGHT ACROSS THE REGION TODAY. A LIGHT NORTHEASTERLY FLOW MAY BRIEFLY DEVELOP BEFORE SEA BREEZE BOUNDARIES BECOME DOMINANT. STORM MOTION IS FORECAST TO BE RELATIVELY SLOW TODAY...AND LOCALLY HEAVY RAINFALL IS POSSIBLE. PONDING IN POORLY DRAINED AREAS AND LOCALIZED STREET FLOODING ARE THE MAIN THREATS. RAIN CHANCES ARE 50-70% ACROSS THE REGION. THE LATEST HRRR RUN SHOWS PRETTY HIGH COVERAGE OF RAIN ACROSS THE REGION. HIGHS ARE FORECAST TO BE IN THE UPPER 80S TO AROUND 90 DEGREES. TONIGHT...THE WEAK AREA OF LOW PRESSURE WILL MOVE CLOSER TO THE EAST COAST...IN THE VICINITY OF PALM BEACH COUNTY COAST BY DAYBREAK. SCATTERED SHOWERS AND A FEW EMBEDDED STORMS ARE FORECAST FOR THE EAST COAST METRO AREAS OVERNIGHT. FRIDAY...THE AREA OF LOW PRESSURE IS FORECAST TO MOVE SLOWLY ACROSS THE REGION...AND SHOWERS AND STORMS ARE LIKELY THROUGHOUT THE DAY. LOCALLY HEAVY RAIN AND MINOR STREET FLOODING IS POSSIBLE. CLOUD COVER AND RAINFALL IS FORECAST TO KEEP TEMPS IN THE 80S. THE AREA OF LOW PRESSURE IS FORECAST TO MOVE SOUTHWEST INTO THE GULF OF MEXICO FRIDAY NIGHT...AND RAIN CHANCES WILL CONTINUE ACROSS COASTAL AREAS. SATURDAY AND SUNDAY...DEEP MOISTURE WILL REMAIN ACROSS SOUTH FLORIDA THROUGH THE WEEKEND. THE ECMWF KEEPS A TROUGH AXIS LINGERING OVER THE REGION EXTENDING TO THE EAST OF THE AREA OF LOW PRESSURE THROUGH SUNDAY. THE GFS MOVES THE SYSTEM QUICKLY WESTWARD ACROSS THE GULF...WITH A RETURN OF THE DEEP EAST TO SOUTHEAST FLOW OBSERVED OVER THE PAST SEVERAL DAYS ON SUNDAY AS THE RIDGE BUILDS WESTWARD ACROSS THE REGION. SO RAIN CHANCES WILL REMAIN IN THE LIKELY CATEGORY ON SATURDAY...AND THEN COME DOWN A LITTLE ON SUNDAY. HIGH PRESSURE WILL THEN BUILD ACROSS THE REGION EARLY NEXT WEEK...WITH A MORE TYPICAL EASTERLY FLOW RAINY SEASON PATTERN. && .AVIATION... INCREASING RAINFALL CHANCES WILL REMAIN POSSIBLE AS A WEAK AREA OF LOW PRESSURE TRACKS WESTWARD INTO THE LOCAL AREA TODAY THROUGH FRIDAY. WINDS WILL REMAIN LIGHT AND MAINLY DRIVEN BY THE LAND/SEA BREEZES AND AFTERNOON CONVECTION. WILL INCLUDE VCTS AT ALL SITES AFTER 15Z AND UPDATE AS CONDITIONS EVOLVE. /85 && .MARINE... A WEAK AREA OF LOW PRESSURE NEAR THE NORTHERN BAHAMAS IS FORECAST TO PUSH SLOWLY WEST ACROSS THE LOCAL ATLANTIC WATERS TONIGHT AND THEN INTO THE GULF WATERS FRIDAY NIGHT. THE NHC IS MONITORING THIS DISTURBANCE...AND THIS COULD IMPACT THE FORECAST FOR FRIDAY AND INTO THE WEEKEND. LIGHT WINDS ARE FORECAST TODAY...WITH GENERALLY EAST TO SOUTHEAST WINDS FRIDAY THROUGH THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 88 75 86 76 / 60 40 60 20 FORT LAUDERDALE 89 76 88 77 / 60 40 60 30 MIAMI 88 75 86 77 / 60 30 70 30 NAPLES 90 74 89 75 / 50 30 60 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...84/AK LONG TERM....84/AK AVIATION...85/AG
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
928 PM EDT WED SEP 10 2014 .UPDATE...MUCH LESS CONVECTION THIS AFTERNOON AND EVE DUE TO DRY AND MORE STABLE AIR ALOFT. A FEW REMAINING SHOWERS ACROSS THE SUWANNEE VALLEY WILL CONTINUE TO MOVE WEST AND WEAKEN. WILL KEEP ISOLATED POPS GOING TONIGHT FOR THE COASTAL WATERS AND LOWER ACROSS THE SUWANNEE VALLEY THE NEXT COUPLE OF HOURS. ADEQUATE LOW LEVEL MOISTURE ALONG WITH LIGHT WINDS AND MOSTLY CLEAR SKIES RESULTS IN PATCHY LATE NIGHT DENSE FOG ACROSS THE INLAND AREAS. && .AVIATION... ALTHOUGH CONDITIONS APPEAR FAVORABLE FOR FOG DEVELOPMENT OVERNIGHT...THE MAJORITY OF THE FOG TOOLS SEEM TO BE DOWNPLAYING THIS THREAT. IN FACT...THE HRRR DOES NOT REALLY INDICATE MUCH IN THE WAY OF FOG AT ALL. NEVERTHELESS...GIVEN THE CONDITIONS...WOULD EXPECT AT LEAST PATCHY SHALLOW FOG DEVELOPMENT LATE TONIGHT...POSSIBLY EVEN SOME PATCHY DENSE FOG AT THE MORE PRONE LOCATIONS SUCH AS VQQ. OTHERWISE...VFR WILL PREVAIL THROUGH THIS TAF PERIOD. && .MARINE...NO HEADLINES. SOUTHEAST WINDS 10 KNOTS. SEAS 2 TO 3 FEET. ISOLATED SHOWERS AND THUNDERSTORMS. RIP CURRENTS: LOW RISK. && .PRELIMINARY POINT TEMPS/POPS... AMG 71 91 74 92 / 20 30 20 20 SSI 74 85 75 85 / 10 10 10 10 JAX 73 89 73 88 / 10 20 10 20 SGJ 74 86 74 85 / 10 10 10 10 GNV 71 89 71 89 / 20 30 20 20 OCF 71 89 72 89 / 20 30 30 20 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ SHULER/PETERSON/WALSH
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
154 PM EDT THU SEP 11 2014 .PREV DISCUSSION... UPDATE... /ISSUED 1122 AM EDT THU SEP 11 2014/ ALREADY SHOWERS ACROSS FAR NORTH GEORGIA. BOTH HRRR AND LOCAL WRF INCREASE DEVELOPMENT INTO THE AFTERNOON HOWEVER TWO OTHER HI RES MODELS ARE MUCH MORE CONSERVATIVE IN TERMS OF PRECIPITATION. CONSIDERING THE TRENDS OF THE HRRR THIS SUMMER...IT MAY BE SLIGHTLY OVERDONE. UPDATED POPS THIS MORNING LEAN TOWARDS THE BETTER CHANCES OF PRECIPITATION...GIVEN APPROACHING FRONTAL BOUNDARY...BUT DO NOT SHOW BETTER PRECIP CHANCES AS FAR SOUTH AS THE HRRR AND THE LOCAL WRF. WILL HAVE TO CONTINUE TO MONITOR THE PRECIP TRENDS THOUGH FOR FUTURE UPDATES. 11 SHORT TERM /TODAY THROUGH FRIDAY/... /ISSUED AT 456 AM EDT THU SEP 11 2014/ MODELS IN CLOSE AGREEMENT THROUGH THE LONG TERM. SURFACE FRONT AND ASSOCIATED SHORT WAVE WILL MOVE INTO THE TENNESSEE VALLEY TODAY AND THIS WILL INCREASE THE RISK OF SHOWERS AND TSTORMS OVER NORTH GA THIS AFTERNOON. ALTHOUGH SHEAR IS NOT IMPRESSIVE...SBCAPES ARE RUNNING IN THE 1500 TO 2500 DEPENDING ON THE MODEL WHICH COULD BE ENOUGH TO PRODUCE STRONG STORMS WITH GUSTY WINDS. THE INHIBITING FACTOR TO STRONG STORMS WILL BE THE H5 HIGH SITTING OVER THE GA/AL BORDER NEAR CSG. PROXIMITY TO THIS COULD KEEP TSTORMS FROM GOING SEVERE...HOWEVER THIS WILL NEED TO BE WATCHED. A DIFFERENT STORY ON FRIDAY AS THE H5 HIGH WEAKENS AND THE SURFACE FRONT DROPS INTO THE STATE. CONVERGENCE ALONG THE FRONT AS WELL AS CAPES IN THE 2000 TO 2500 RANGE BY ALL MODELS WILL BE ENOUGH FOR A FEW STRONG TO SEVERE STORMS TO DEVELOP DURING FRIDAY AFTERNOON...MAINLY ACROSS NORTH GEORGIA. 17 LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... /ISSUED AT 456 AM EDT THU SEP 11 2014/ EXTENDED MODELS CONSISTENT WITH SHOWING AFOREMENTIONED SHORT-TERM FRONT STALLED ACROSS THE STATE SATURDAY AS A SECONDARY FRONT APPROACHES THE AREA. UPPER LOW TRACKING ACROSS THE SOUTHERN GREAT LAKES WILL PULL THE SECOND FRONT INTO THE REGION QUICKLY BEHIND THE FIRST...WITH AMPLE MOISTURE POSITIONED ACROSS THE STATE SATURDAY THROUGH EARLY NEXT WEEK AS BOUNDARIES BECOME STATIONARY AND PILE UP ACROSS CENTRAL GEORGIA. THESE FRONTS WILL SERVE AS A FOCUS FOR ENHANCED SHOWERS AND THUNDERSTORMS ACROSS THE STATE. NOT UNTIL A SHORTWAVE SWEEPS INTO THE REGION TUESDAY AND KICKS THE STATIONARY FRONTS EASTWARD DOES THE STATE REALLY GET TO SEE SOME DRIER AIR MOVE INTO THE STATE. FOR NOW...HAVE OPTED TO CONTINUE WITH GOOD CHANCE TO LIKELY POPS ACROSS A VAST MAJORITY OF THE AREA SATURDAY THROUGH MONDAY. INTO MID WEEK NEXT WEEK THE EXTENDED MODELS DISAGREE WITH THE EXTENT THE DRIER AIR PUSHES INTO THE STATE AND WITH A SERIES OF UPPER LEVEL DISTURBANCES THROUGH THE AREA. AS A RESULT...ASIDE FROM ZERO POPS IN FAR NW GEORGIA ON SUNDAY NIGHT AND TUESDAY NIGHT...CARRY AT LEAST GOOD CHANCE POPS ACROSS THE STATE EACH AFTERNOON...AND AT LEAST SLIGHT CHANCE EACH OVERNIGHT. MODELS ARE INDICATING THAT COOLER TEMPERATURES ARE IN STORE FOR THE STATE BY THE WEEKEND...ESPECIALLY WITH THE INFLUENCE OF THE PRECIPITATION AND CLOUDS. ANTICIPATE AN OVERALL COOLING TREND THROUGH THE WEEK...AND BY THE LATTER HALF OF NEXT WEEK COULD BE BELOW NORMAL FOR TEMPERATURES. AS OF NOW...WEEKEND QPF IS EXPECTED TO BE 0.75 TO 1.5 INCHES...WITH THE HIGHEST AMOUNTS GENERALLY NOSING INTO THE STATE FROM THE CAROLINAS. LOCALLY HEAVIER AMOUNTS CAN BE EXPECTED. AT THIS TIME...GUIDANCE SUGGESTS MUCH OF THE STATE CAN HANDLE THIS AMOUNT OF RAINFALL AND WILL NOT ISSUE ANY KIND OF WATCH AT THIS TIME. 31 && .AVIATION... 18Z UPDATE... A BIT OF UNCERTAINTY IN TERMS OF SHRA/TSRA POTENTIAL AT NORTHERN SITES. THINK SOME DEVELOPMENT WILL DRIFT INTO THE ATL SITES AT SOME POINT. ADVERTISING TSRA IN THE TAFS SINCE THERE IS SOME INSTABILITY...BUT BASED ON CURRENT RADAR TRENDS...COULD END UP BEING JUST SHRA. CHANCES DECREASE INTO AHN AND THEN EVEN MORE INTO MCN AND CSG. //ATL CONFIDENCE...18Z UPDATE... HIGH CONFIDENCE ON WIND. MEDIUM CONFIDENCE ON CIGS AND VSBYS. 11 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 90 71 90 70 / 30 30 60 60 ATLANTA 88 72 89 72 / 40 30 50 50 BLAIRSVILLE 82 67 81 65 / 60 50 60 60 CARTERSVILLE 88 71 89 69 / 50 40 50 50 COLUMBUS 91 73 93 72 / 20 20 50 50 GAINESVILLE 85 71 87 69 / 40 30 60 60 MACON 92 71 93 71 / 20 10 50 50 ROME 89 70 89 69 / 50 50 60 50 PEACHTREE CITY 89 70 90 69 / 30 20 50 50 VIDALIA 92 72 93 72 / 20 10 40 40 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...11 LONG TERM....BAKER AVIATION...11
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1122 AM EDT THU SEP 11 2014 .UPDATE... ALREADY SHOWERS ACROSS FAR NORTH GEORGIA. BOTH HRRR AND LOCAL WRF INCREASE DEVELOPMENT INTO THE AFTERNOON HOWEVER TWO OTHER HI RES MODELS ARE MUCH MORE CONSERVATIVE IN TERMS OF PRECIPITATION. CONSIDERING THE TRENDS OF THE HRRR THIS SUMMER...IT MAY BE SLIGHTLY OVERDONE. UPDATED POPS THIS MORNING LEAN TOWARDS THE BETTER CHANCES OF PRECIPITATION...GIVEN APPROACHING FRONTAL BOUNDARY...BUT DO NOT SHOW BETTER PRECIP CHANCES AS FAR SOUTH AS THE HRRR AND THE LOCAL WRF. WILL HAVE TO CONTINUE TO MONITOR THE PRECIP TRENDS THOUGH FOR FUTURE UPDATES. 11 && .PREV DISCUSSION... SHORT TERM /TODAY THROUGH FRIDAY/... /ISSUED AT 456 AM EDT THU SEP 11 2014/ MODELS IN CLOSE AGREEMENT THROUGH THE LONG TERM. SURFACE FRONT AND ASSOCIATED SHORT WAVE WILL MOVE INTO THE TENNESSEE VALLEY TODAY AND THIS WILL INCREASE THE RISK OF SHOWERS AND TSTORMS OVER NORTH GA THIS AFTERNOON. ALTHOUGH SHEAR IS NOT IMPRESSIVE...SBCAPES ARE RUNNING IN THE 1500 TO 2500 DEPENDING ON THE MODEL WHICH COULD BE ENOUGH TO PRODUCE STRONG STORMS WITH GUSTY WINDS. THE INHIBITING FACTOR TO STRONG STORMS WILL BE THE H5 HIGH SITTING OVER THE GA/AL BORDER NEAR CSG. PROXIMITY TO THIS COULD KEEP TSTORMS FROM GOING SEVERE...HOWEVER THIS WILL NEED TO BE WATCHED. A DIFFERENT STORY ON FRIDAY AS THE H5 HIGH WEAKENS AND THE SURFACE FRONT DROPS INTO THE STATE. CONVERGENCE ALONG THE FRONT AS WELL AS CAPES IN THE 2000 TO 2500 RANGE BY ALL MODELS WILL BE ENOUGH FOR A FEW STRONG TO SEVERE STORMS TO DEVELOP DURING FRIDAY AFTERNOON...MAINLY ACROSS NORTH GEORGIA. 17 LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... /ISSUED AT 456 AM EDT THU SEP 11 2014/ EXTENDED MODELS CONSISTENT WITH SHOWING AFOREMENTIONED SHORT-TERM FRONT STALLED ACROSS THE STATE SATURDAY AS A SECONDARY FRONT APPROACHES THE AREA. UPPER LOW TRACKING ACROSS THE SOUTHERN GREAT LAKES WILL PULL THE SECOND FRONT INTO THE REGION QUICKLY BEHIND THE FIRST...WITH AMPLE MOISTURE POSITIONED ACROSS THE STATE SATURDAY THROUGH EARLY NEXT WEEK AS BOUNDARIES BECOME STATIONARY AND PILE UP ACROSS CENTRAL GEORGIA. THESE FRONTS WILL SERVE AS A FOCUS FOR ENHANCED SHOWERS AND THUNDERSTORMS ACROSS THE STATE. NOT UNTIL A SHORTWAVE SWEEPS INTO THE REGION TUESDAY AND KICKS THE STATIONARY FRONTS EASTWARD DOES THE STATE REALLY GET TO SEE SOME DRIER AIR MOVE INTO THE STATE. FOR NOW...HAVE OPTED TO CONTINUE WITH GOOD CHANCE TO LIKELY POPS ACROSS A VAST MAJORITY OF THE AREA SATURDAY THROUGH MONDAY. INTO MID WEEK NEXT WEEK THE EXTENDED MODELS DISAGREE WITH THE EXTENT THE DRIER AIR PUSHES INTO THE STATE AND WITH A SERIES OF UPPER LEVEL DISTURBANCES THROUGH THE AREA. AS A RESULT...ASIDE FROM ZERO POPS IN FAR NW GEORGIA ON SUNDAY NIGHT AND TUESDAY NIGHT...CARRY AT LEAST GOOD CHANCE POPS ACROSS THE STATE EACH AFTERNOON...AND AT LEAST SLIGHT CHANCE EACH OVERNIGHT. MODELS ARE INDICATING THAT COOLER TEMPERATURES ARE IN STORE FOR THE STATE BY THE WEEKEND...ESPECIALLY WITH THE INFLUENCE OF THE PRECIPITATION AND CLOUDS. ANTICIPATE AN OVERALL COOLING TREND THROUGH THE WEEK...AND BY THE LATTER HALF OF NEXT WEEK COULD BE BELOW NORMAL FOR TEMPERATURES. AS OF NOW...WEEKEND QPF IS EXPECTED TO BE 0.75 TO 1.5 INCHES...WITH THE HIGHEST AMOUNTS GENERALLY NOSING INTO THE STATE FROM THE CAROLINAS. LOCALLY HEAVIER AMOUNTS CAN BE EXPECTED. AT THIS TIME...GUIDANCE SUGGESTS MUCH OF THE STATE CAN HANDLE THIS AMOUNT OF RAINFALL AND WILL NOT ISSUE ANY KIND OF WATCH AT THIS TIME. 31 AVIATION... 12Z UPDATE... /ISSUED 729 AM EDT THU SEP 11 2014/ NOT A CONTINUOUS CLOUD COVER ACROSS THE FORECAST AREA WITH POCKETS OF IFR CLOUDS OVER CENTRAL GA AND POCKES OF 3000 TO 4000 FT CIGS ACROSS THE REST OF THE FORECAST AREA. ALL AREAS SHOULD BE VFR WITH INCREASING CLOUD COVER BY LATE THIS MORNING...AND REMAIN VFR FOR THE REMAINDER OF THE FORECAST. DO EXPECT A MOSTLY BROKEN CLOUD COVER ACROSS NORTH GA THROUGH THE FORECAST WHILE CENTRAL GA SHOULD BE SCT-BKN. WINDS WILL BE WEST TO SOUTHWEST WITH SPEEDS OF 6 KTS OR LESS TODAY...GOING NEAR CALM AFTER SUNSET THIS EVENING. ISOLATED SHOWERS HAVE ALREADY DEVELOPED ACROSS NORTH GA AND WHILE THERE COULD BE ISOLATED TSRA THIS AFTERNOON OVER THE FORECAST AREA...THE BEST CHANCES WILL REMAIN NORTH OF THE TAF SITES. //ATL CONFIDENCE...12Z UPDATE... MEDIUM CONFIDENCE ON CIGS. HIGH CONFIDENCE ON REMAINING ELEMENTS. 17 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 90 71 90 70 / 40 40 60 60 ATLANTA 88 72 89 72 / 40 40 50 50 BLAIRSVILLE 82 67 81 65 / 60 50 60 60 CARTERSVILLE 88 71 89 69 / 50 50 60 50 COLUMBUS 91 73 93 72 / 20 20 40 40 GAINESVILLE 85 71 87 69 / 50 50 60 60 MACON 92 71 93 71 / 20 20 40 40 ROME 89 70 89 69 / 50 50 60 50 PEACHTREE CITY 89 70 90 69 / 30 30 50 40 VIDALIA 92 72 93 72 / 20 20 40 40 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...11 LONG TERM....BAKER AVIATION...11
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
302 PM CDT THU SEP 11 2014 .DISCUSSION... 240 PM...FORECAST CONCERNS INCLUDE MUCH BELOW NORMAL TEMPERATURES AND CHANCES FOR SHOWERS THROUGH SATURDAY AND AGAIN ON MONDAY. STRATUS DECK HAS REMAINED MOSTLY OVERCAST TODAY AND THAT HAS HELD TEMPS IN THE LOWER/MID 50S MOST AREAS...SOME 20 TO 25 DEGREES BELOW NORMAL FOR MID SEPTEMBER. SEE CLIMATE SECTION BELOW FOR RECORDS. CLOUD COVER IS EXPECTED TO REMAIN AT LEAST BROKEN IF NOT OVERCAST OVERNIGHT INTO FRIDAY MORNING...SO NOT EXPECTING MUCH OF A SWING IN TEMPS WITH LOWS TONIGHT IN THE MID/UPPER 40S. AS COLDER AIR CONTINUES TO SPREAD ACROSS THE AREA...A FEW LAKE EFFECT RAIN SHOWERS HAVE DEVELOPED OVER THE SOUTHEASTERN PART OF THE LAKE. AS HIGH PRESSURE MOVES NORTH OF THE AREA TONIGHT... WINDS WILL TURN MORE NORTHEAST AND THESE LAKE EFFECT RAIN SHOWERS WILL BEGIN TO AFFECT NORTHEAST IL OVERNIGHT INTO FRIDAY MORNING. COVERAGE REMAINS A BIT UNCERTAIN AND HAVE ONLY BUMPED POPS UP TO LOW CHANCE. TRENDS WILL NEED TO BE MONITORED LATER TONIGHT WITH THE POSSIBILITY THAT POPS WILL NEED TO BE BUMPED UP FURTHER. LAKE EFFECT RAIN SHOWERS WILL CONTINUE INLAND ACROSS NORTHERN IL FRIDAY MORNING AS FLOW TURNS MORE EAST/NORTHEAST. CLOUD COVER WILL LIKELY REMAIN MOSTLY CLOUDY AND THIS COULD LIMIT TEMPS TO JUST THE 50S AGAIN ON FRIDAY. SOUTHERN AREAS MAY SEE A FEW BREAKS WITH THE POTENTIAL TO REACH 60...BUT OVERALL FRIDAY WILL CONTINUE MUCH BELOW NORMAL. AN UPPER WAVE WILL MOVE ACROSS THE REGION FRIDAY AFTERNOON INTO FRIDAY EVENING WITH SHOWERS/LIGHT RAIN SPREADING ACROSS THE NORTHWEST CWA IN THE AFTERNOON THEN ACROSS MUCH OF THE AREA EARLY FRIDAY EVENING. BUMPED POPS UP SOME...WITH LIKELY OVER THE NORTHERN TWO THIRDS OF THE CWA...POSSIBLE POPS WILL NEED TO BE INCREASED HERE AS WELL...THOUGH TOTAL QFP AMOUNTS SHOULD BE IN THE 0.25 TO 0.5 INCH RANGE. THIS WAVE IS FAIRLY PROGRESSIVE...SO TRIMMED POPS FROM THE WEST OVERNIGHT. LAKE EFFECT RAIN SHOWERS MAY CONTINUE INTO NORTHWEST INDIANA SATURDAY MORNING BEFORE ENDING IN THE AFTERNOON. DESPITE SOME SUNSHINE SATURDAY...AIRMASS WILL BE EVEN COLDER THAN TODAY AND FRIDAY. NOT SURE HOW MUCH MID SEPTEMBER SUN WILL AID TEMP INCREASE SO MAINTAINED JUST LOWER 60S FOR HIGHS. HIGH PRESSURE PASSES ACROSS THE REGION SATURDAY NIGHT INTO SUNDAY MORNING WITH LOWS DIPPING INTO THE LOWER 40S MOST AREAS...BUT WARMER IN THE IMMEDIATE CHICAGO METRO AREA. ANOTHER FAST MOVING WAVE WILL MOVE ACROSS THE AREA MONDAY BRINGING ANOTHER CHANCE OF SHOWERS. DEPENDING ON TIMING...CLOUD COVER AND PRECIP COULD HOLD TEMPS DOWN MONDAY BUT FOR NOW HAVE MAINTAINED 60S. BEYOND MONDAY...HIGH PRESSURE SPREADS ACROSS THE REGION WITH DRY WEATHER EXPECTED MID WEEK BUT TEMPS STILL BELOW NORMAL. CMS && .CLIMATE... 915 AM CDT SEP 11 2014 AN UNSEASONABLY COOL AIR MASS OVER THE REGION INTO THE WEEKEND COULD PUT SOME RECORD TEMPERATURES IN JEOPARDY AT CHICAGO AND ROCKFORD. RECORD LOW MAX TEMPERATURES ARE MOST LIKELY TO BE THREATENED. RECORD LOW MAX TEMPERATURES SEPTEMBER 11-13 ------------------------------------------- SEPTEMBER 11 SEPTEMBER 12 SEPTEMBER 13 ------------ ------------ ------------ CHICAGO 61/1940 53/1902 55/1880 ROCKFORD 55/1914 56/1943 55/1970 RC && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * MVFR CIGS THROUGH THE PERIOD...WITH POTENTIAL FOR IFR LATE TONIGHT INTO FRIDAY MORNING. * NORTH-NORTHEAST WINDS 360-030 DEG AT OR BELOW 10 KT INTO THIS EVENING. * LAKE EFFECT SHOWERS LATE TONIGHT INTO FRIDAY MORNING. * NORTH-NORTHEAST WINDS AROUND 10 KT BECOMING NORTHEAST ON FRIDAY. * RAIN SHOWERS MOVING INTO AREA LATE FRIDAY AFTERNOON...WITH PREVAILING RAIN AND CIG/VSBY IMPACTS MORE LIKELY FRIDAY EVE. RC //DISCUSSION...UPDATED 18Z... UNSEASONABLY COOL AIR MASS OVER THE REGION IS RESULTING IN SEVERAL CONCERNS THIS PERIOD. MOISTURE LOCKED UNDER INVERSION IS KEEPING STRATUS DECK IN PLACE THIS AFTERNOON AND NOW EXPECT PRIMARILY MVFR CIGS THROUGH THE PERIOD. THE COOL AIR MASS MOVING OVER THE MILD LAKE WATERS WILL LIKELY RESULT IN THE DEVELOPMENT OF LAKE EFFECT SHOWERS LATE TONIGHT INTO FRIDAY MORNING. HIGHER RESOLUTION GUIDANCE HINTS THAT DECENT BAND COULD EVEN SET UP INTO NORTHWEST INDIANA INITIALLY AND THEN GRADUALLY SHIFT NORTHEAST. HAVE MEDIUM TO HIGH CONFIDENCE THAT THERE WILL BE SHOWERS AROUND...BUT LOW CONFIDENCE IN DIRECT IMPACTS TO ORD/MDW/GYY...THUS HAVE CARRIED VCSH MENTION. IF SHRA ARE MORE ORGANIZED AND DIRECTLY IMPACT TERMINALS...THERE COULD BE IMPACTS TO VSBY. ONSHORE FLOW IS EXPECTED TO ALSO RESULT IN LOWERING OF MVFR CIGS AT EASTERN TERMINALS...WITH SOME GUIDANCE MEMBERS INDICATING POTENTIAL FOR IFR. HAVE HINTED AT THIS WITH SCT IFR CLOUDS IN TAF. A FAIRLY STRONG UPPER LEVEL DISTURBANCE AND REINFORCING SHOT OF COOL AIR WILL MOVE ACROSS REGION DURING THE DAY ON FRIDAY...AND THIS WILL RESULT IN RAIN SHOWERS SPREADING IN FROM NORTHWEST. PREVAILING RAIN SHOWERS ARE EXPECTED IN ROCKFORD VICINITY DURING AFTERNOON...BUT NOT UNTIL BEYOND THE 30 HOUR ORD TAF AT THE EASTERN TAF SITES. REGARDING WINDS...PREDOMINANTLY NORTHERLY WINDS EARLY THIS AFTERNOON ARE EXPECTED TO SHIFT TO NORTHEAST OR NORTH-NORTHEAST LATER THIS AFTERNOON INTO THE EVENING. IF AN ORGANIZED LAKE EFFECT BAND SETS UP INTO NORTHEAST ILLINOIS OVERNIGHT...WINDS MAY TREND MORE NORTHERLY OR EVEN NORTH-NORTHWEST...BUT THEN NORTHEAST WINDS AROUND 10 KT ARE EXPECTED FRIDAY MORNING THROUGH THE END OF THE PERIOD. RC //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM-HIGH IN MVFR CIGS CONTINUING THROUGH THE PERIOD. LOW IN IFR LATE TONIGHT INTO FRIDAY. * MEDIUM IN WIND TRENDS THROUGH THE PERIOD. MEDIUM IN WIND SPEEDS INTO THIS EVENING. * MEDIUM-HIGH IN LAKE EFFECT SHOWERS DEVELOPING TONIGHT...LOW IN DIRECT IMPACTS TO TERMINALS. * MEDIUM IN PREVAILING RAIN SHOWERS MORE LIKELY TO MOVE IN FRIDAY EVENING. RC //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... FRIDAY NIGHT...SHRA LIKELY. MVFR/IFR CIGS PSBL. SATURDAY...VFR. GUSTY NW WINDS IN THE MORNING. SUNDAY...VFR. MONDAY...CHC SHRA DURING THE DAY. MVFR CIGS PSBL. TUESDAY AND WEDNESDAY...VFR KMD && .MARINE... 209 PM CDT STRONG LOW PRESSURE SYSTEM THAT BROUGHT THE GALE FORCE WINDS HAS CONTINUED TO LIFT NORTHEAST AWAY FROM THE GREAT LAKES REGION...WITH THE GRADIENT OVER LAKE MICHIGAN STEADILY WEAKENING. THE GRADIENT WILL REMAIN JUST ENOUGH TO PRODUCE WINDS BETWEEN 15 AND 25 KT OVERNIGHT GENERALLY FROM THE NORTH...BEGINNING TO TURN SLIGHTLY NORTHEAST AHEAD OF THE BROAD RIDGE OF HIGH PRESSURE OVER THE CENTRAL PLAINS THAT IS POISED TO ARRIVE SATURDAY INTO SUNDAY MORNING. ANOTHER FRONTAL BOUNDARY WILL ARRIVE FRIDAY EVENING WHICH WILL PROVIDE A REINFORCING PUSH OF GUSTY NORTH WINDS TO THE LAKE...WITH THE GRADIENT BEING SLIGHTLY TIGHTER ALONG THE SOUTHERN HALF OF THE LAKE FRIDAY NIGHT THROUGH EARLY SATURDAY. WAVES WILL REMAIN ELEVATED THROUGH FRIDAY NIGHT...CREATING HAZARDOUS WAVES TO SMALL CRAFT THROUGH THIS PERIOD. THEN THE WAVES SHOULD STEADILY DIMINISH BY EARLY SATURDAY MORNING TO ALLOW THE SMALL CRAFT TO END. HOWEVER IF THE WINDS REMAIN ELEVATED...THIS WILL KEEP WAVES UP AS WELL THROUGH DAYBREAK SAT. HIGH PRESSURE IS THEN POISED TO BUILD OVER LAKE MICHIGAN SATURDAY EVENING AND CONTINUE THROUGH SUNDAY. WHICH WILL THEN PROVIDE MUCH LIGHTER WINDS AND SUBSIDING WAVES. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014 UNTIL 5 PM SATURDAY. IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 5 PM SATURDAY. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 10 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 259 PM CDT Thu Sep 11 2014 .SHORT TERM...(Tonight) ISSUED AT 259 PM CDT THU SEP 11 2014 Cold front just south of the Ohio River Valley this afternoon as high pressure builds into the Midwest. Northerly flow at the sfc bringing unseasonably cool temps into the region, in stark contrast to the weather of the last few days. Cooler temperatures expected to continue into the overnight hours. With lows dipping into the upper 40s across the nrn portions of the state...and low 50s before dawn for much of Illinois. Breaks in the cloud cover off to the west not having much success in moving into the region. As a result, continued cloud coverage expected through the overnight hours as llvl RH has remained trapped. Both NAM and HRRR slow to move clouds out, though some brief clearing is possible NW of the Illinois River. && .LONG TERM...(Friday through Thursday) ISSUED AT 259 PM CDT THU SEP 11 2014 Cool and cloudy conditions are expected again Friday as low level northerly flow continues with a strong capping inversion at around 850 mb. An upper level shortwave will be rapidly approaching from the west. The axis of the shortwave expected to cross Illinois late Friday evening to early Saturday morning...pushing another frontal boundary through the region. Current model forecasts are fairly consistent keeping precipitation with this feature mainly north of I-72...and modest amounts around 0.10 inches or less. Have PoPs beginning Friday afternoon west of I-55 as lift associated with the approaching shortwave begins...then PoPs spread through most areas I-55 northward Friday evening. The system moves rapidly east- northeastward leaving a cool and dry weekend behind it...with highs in the 60s and lows in the 40s...as high pressure settles over the area. The next chance for precipitation will be Monday as models consistently track another broad trough through the midwest. Cool dry northwesterly flow aloft is expected to follow for the remainder of the week with little chance for any precipitation and below normal temperatures continuing. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) ISSUED AT 1234 PM CDT THU SEP 11 2014 Not much in the way of a change in the forecast. MVFR continuing, with some IFR conditions still possible today as cigs are right on the cusp btwn two categories above and below 1kft. Some breaks in the clouds are still well to the west and northwest. Models are breaking between some drying out of the low levels and the NAM holding on to the higher RH below 850mb. HRRR keeping MVFR through the day with some breaks approaching PIA, but certainly not predominant and will amend accordingly should the sun break through. However, the HRRR going into the evening hours starts to drop the cigs once again, with IFR very near. Not going that pessimistic just yet, but not clearing the MVFR through the end of the fcst pd. North/northeast winds throughout. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...HJS LONG TERM...ONTON AVIATION...HJS
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1255 PM CDT THU SEP 11 2014 .DISCUSSION... 339 AM CDT WHAT A DIFFERENCE A DAY MAKES...AS THE FIRST REAL AUTUMN-LIKE PUSH OF COOL AIR SPREADS INTO THE MIDWEST TODAY IN THE WAKE OF YESTERDAYS COLD FRONT. MAIN FOCUS OF THE FORECAST ARE THESE MID OCTOBER-LIKE TEMPERATURES OVER THE NEXT SEVERAL DAYS...A CHANCE OF RAIN FRIDAY AND FRIDAY NIGHT...AND EVEN THE POTENTIAL FOR SOME LAKE EFFECT RAIN SHOWERS AS OUR UNSEASONABLY COOL AIR SPREADS OVER THE RELATIVELY WARM LAKE MICHIGAN WATERS. DEEP SURFACE LOW PRESSURE WHICH MOVED ACROSS THE UPPER MIDWEST WEDNESDAY WAS PULLING AWAY ACROSS SOUTHWESTERN QUEBEC PER EARLY MORNING ANALYSIS...WITH THE TRAILING COLD FRONT PUSHING THROUGH THE LOWER OHIO VALLEY. MUCH COOLER WAS SPREADING IN FROM THE NORTH AND NORTHWEST...WITH UPSTREAM TEMPS IN THE MID-40S ACROSS MINNESOTA AND WISCONSIN AND EVEN A FEW LOW-MID 30S NOTED UP IN THE MINNESOTA ARROWHEAD. THIS COOL AIR MASS WILL CONTINUE TO SPREAD INTO THE GREAT LAKES AND MIDWEST TODAY AS SPRAWLING CANADIAN HIGH PRESSURE MOVES SLOWLY SOUTHEAST ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST. IR SATELLITE IMAGERY SHOWS EXTENSIVE LOW CLOUD SHIELD ACROSS MUCH OF THE UPPER MIDWEST...AND WITH ONLY WEAK SUBSIDENCE NOTED IN MODEL TIME HEIGHT SECTIONS IT APPEARS THAT CLOUD COVER WILL BE SLOW TO ERODE IN PERSISTENT COOL ADVECTION REGIME TODAY. LOW LEVEL THERMAL PROGS AND GUIDANCE NUMBERS ALL POINT TO HIGHS RANGING FROM AROUND 60 NEAR THE IL/WI BORDER TODAY...TO THE LOW-MID 60S FAR SOUTH IN EAST CENTRAL IL. TO PUT THESE TEMPS INTO PERSPECTIVE...61 IS THE RECORD LOW MAXIMUM TEMP FOR TODAY/SEPTEMBER 11 FOR CHICAGO...WHICH WOULD BE NORMAL HIGH TEMPERATURE RANGE FOR MID-LATE OCTOBER. EXTENSIVE CLOUD COVER AND A MODEST NORTH WIND WILL HELP KEEP TEMPS IN THE 40S TONIGHT. 850 MB TEMPS LOWER TO ABOUT +2 OR +3 C TONIGHT...WITH SOUTHERN LAKE MICHIGAN WATER TEMPERATURES IN THE LOW-MID 60S F. FORECAST SOUNDINGS DEPICT A RISING INVERSION LEVEL TONIGHT INTO EARLY FRIDAY WHICH WOULD SUPPORT LAKE-INDUCED INSTABILITY CLOUDS AND POSSIBLY SOME LIGHT SPRINKLES OR SHOWERS...MAINLY LATE TONIGHT INTO EARLY FRIDAY AS THE INVERSION HEIGHT INCREASES. LOW LEVEL WINDS TURN NORTHEASTERLY DURING THIS TIME WHICH MAY BRING A FEW OF THESE LIGHT SHOWERS INTO NORTHEAST IL. A GREATER CHANCE OF RAIN THEN LOOKS TO DEVELOP ACROSS THE AREA FRIDAY...AS THE STRONG DIGGING SHORT WAVE SEEN IN CURRENT WATER VAPOR IMAGERY ACROSS THE NORTHERN ROCKIES APPROACHES. IMPRESSIVE FORCING FOR VERTICAL MOTION DEVELOPS PER MODEL OMEGA/Q-VECTOR CONVERGENCE FIELDS AS THIS WAVE PROPAGATES ALONG THE ELEVATED BAROCLINIC ZONE ASSOCIATED WITH OUR RECENT LOW LEVEL COOL AIR INTRUSION. STRONG HEIGHT FALLS AND STRENGTHENING UPPER JET CORE DEVELOP ALOFT...WITH LOWER LEVEL FRONTOGENETIC FORCING ALSO INCREASING ESPECIALLY FRIDAY AFTERNOON/NIGHT AS THE TROUGH NEARS. GUIDANCE IN GOOD AGREEMENT IN DEVELOPING RAIN ACROSS NORTHWEST HALF OF THE CWA FRIDAY...AND ACROSS THE REMAINDER OF THE FORECAST AREA FRIDAY NIGHT WITH GENERALLY 0.15-0.25 INCHES OF QPF. SHARP MID-LEVEL TROUGH AXIS PASSES TOWARD SUNRISE SATURDAY MORNING...WITH QUICK SHUT-OFF OF PRECIPITATION EXPECTED GIVEN STRONG MID-LEVEL SUBSIDENCE AND SHARPLY RISING HEIGHTS BEHIND THE SHORT WAVE. EXCEPTION MAY BE ALONG THE LAKE AND INTO NORTHWEST INDIANA SATURDAY MORNING AS SOME POTENTIAL FOR LAKE EFFECT SHOWERS WILL LINGER UNTIL SUBSIDENCE INVERSION STRENGTHENS AND LOWERS ENOUGH TO LIMIT DEPTH OF INSTABILITY OVER THE LAKE WATERS. SURFACE HIGH PRESSURE RIDGE DEVELOPS ACROSS THE REGION IN THE WAKE OF THE STRONG DEPARTING MID-LEVEL WAVE SATURDAY AFTERNOON AND NIGHT WITH GOOD POTENTIAL FOR SCOURING OUT CLOUDS. CLEARING LIKELY TO BE OCCURRING TOWARD SUNRISE SATURDAY FROM THE WEST WITH SOME NORTH WIND LIKELY KEEPING TEMPS FROM BOTTOMING OUT...THOUGH SOME AREAS NOT FAR WEST/NORTH OF THE CWA COULD SEE SATURDAY NIGHT/SUNDAY AM MINS IN THE 30S. DESPITE THE RETURN OF SUNSHINE NOT MUCH CHANGE IN HIGH TEMPERATURE IS EXPECTED SATURDAY WITH REINFORCING PUSH OF COOLER AIR AHEAD OF THE HIGH OFFSETTING ANY GAINS FROM MORE SUNSHINE. TEMPS IN THE LOW 60S/LOWS IN THE 40S EXPECTED SATURDAY AND SATURDAY NIGHT... THOUGH THE PROSPECT FOR A FEW SUNDAY AM LOWS IN THE 30S CANT BE RULED OUT WITH LIGHT WINDS AND POTENTIALLY CLEAR SKIES. THE SURFACE HIGH PRESSURE RIDGE DRIFTS SOUTHEAST AND WEAK WARM ADVECTION RETURNS ON SUNDAY. RELATIVELY MODEST GAINS IN TEMPS EXPECTED HOWEVER WITH MAX TEMPS MODERATING ONLY TO THE 65-70 RANGE INTO EARLY NEXT WEEK AS ANOTHER MID-LEVEL WAVE APPROACHES. NEXT CHANCE OF RAIN ACCOMPANIES THIS SYSTEM ON MONDAY. RATZER && .CLIMATE... 915 AM CDT SEP 11 2014 AN UNSEASONABLY COOL AIR MASS OVER THE REGION INTO THE WEEKEND COULD PUT SOME RECORD TEMPERATURES IN JEOPARDY AT CHICAGO AND ROCKFORD. RECORD LOW MAX TEMPERATURES ARE MOST LIKELY TO BE THREATENED. RECORD LOW MAX TEMPERATURES SEPTEMBER 11-13 ------------------------------------------- SEPTEMBER 11 SEPTEMBER 12 SEPTEMBER 13 ------------ ------------ ------------ CHICAGO 61/1940 53/1902 55/1880 ROCKFORD 55/1914 56/1943 55/1970 RC && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * MVFR CIGS THROUGH THE PERIOD...WITH POTENTIAL FOR IFR LATE TONIGHT INTO FRIDAY MORNING. * NORTH-NORTHEAST WINDS 350-020 DEG AROUND 10 KT BECOMING MORE NORTHEAST 020-040 DEG AROUND 10 KT BY ABOUT 20Z. * LAKE EFFECT SHOWERS LATE TONIGHT INTO FRIDAY MORNING. * NORTH-NORTHEAST WINDS AROUND 10 KT BECOMING NORTHEAST ON FRIDAY. * RAIN SHOWERS MOVING INTO AREA LATE FRIDAY AFTERNOON...WITH PREVAILING RAIN AND CIG/VSBY IMPACTS MORE LIKELY FRIDAY EVE. RC //DISCUSSION...UPDATED 18Z... UNSEASONABLY COOL AIR MASS OVER THE REGION IS RESULTING IN SEVERAL CONCERNS THIS PERIOD. MOISTURE LOCKED UNDER INVERSION IS KEEPING STRATUS DECK IN PLACE THIS AFTERNOON AND NOW EXPECT PRIMARILY MVFR CIGS THROUGH THE PERIOD. THE COOL AIR MASS MOVING OVER THE MILD LAKE WATERS WILL LIKELY RESULT IN THE DEVELOPMENT OF LAKE EFFECT SHOWERS LATE TONIGHT INTO FRIDAY MORNING. HIGHER RESOLUTION GUIDANCE HINTS THAT DECENT BAND COULD EVEN SET UP INTO NORTHWEST INDIANA INITIALLY AND THEN GRADUALLY SHIFT NORTHEAST. HAVE MEDIUM TO HIGH CONFIDENCE THAT THERE WILL BE SHOWERS AROUND...BUT LOW CONFIDENCE IN DIRECT IMPACTS TO ORD/MDW/GYY...THUS HAVE CARRIED VCSH MENTION. IF SHRA ARE MORE ORGANIZED AND DIRECTLY IMPACT TERMINALS...THERE COULD BE IMPACTS TO VSBY. ONSHORE FLOW IS EXPECTED TO ALSO RESULT IN LOWERING OF MVFR CIGS AT EASTERN TERMINALS...WITH SOME GUIDANCE MEMBERS INDICATING POTENTIAL FOR IFR. HAVE HINTED AT THIS WITH SCT IFR CLOUDS IN TAF. A FAIRLY STRONG UPPER LEVEL DISTURBANCE AND REINFORCING SHOT OF COOL AIR WILL MOVE ACROSS REGION DURING THE DAY ON FRIDAY...AND THIS WILL RESULT IN RAIN SHOWERS SPREADING IN FROM NORTHWEST. PREVAILING RAIN SHOWERS ARE EXPECTED IN ROCKFORD VICINITY DURING AFTERNOON...BUT NOT UNTIL BEYOND THE 30 HOUR ORD TAF AT THE EASTERN TAF SITES. REGARDING WINDS...PREDOMINANTLY NORTHERLY WINDS EARLY THIS AFTERNOON ARE EXPECTED TO SHIFT TO NORTHEAST OR NORTH-NORTHEAST LATER THIS AFTERNOON INTO THE EVENING. IF AN ORGANIZED LAKE EFFECT BAND SETS UP INTO NORTHEAST ILLINOIS OVERNIGHT...WINDS MAY TREND MORE NORTHERLY OR EVEN NORTH-NORTHWEST...BUT THEN NORTHEAST WINDS AROUND 10 KT ARE EXPECTED FRIDAY MORNING THROUGH THE END OF THE PERIOD. RC //ORD AND MDW CONFIDENCE...UPDATED 18Z... * MEDIUM-HIGH IN MVFR CIGS CONTINUING THROUGH THE PERIOD. LOW IN IFR LATE TONIGHT INTO FRIDAY. * MEDIUM IN WIND TRENDS THROUGH THE PERIOD. MEDIUM-HIGH IN SPEEDS AROUND 10 KT WITH NORTH-NORTHEAST WINDS THIS AFTERNOON. * MEDIUM-HIGH IN LAKE EFFECT SHOWERS DEVELOPING TONIGHT...LOW IN DIRECT IMPACTS TO TERMINALS. * MEDIUM IN PREVAILING RAIN SHOWERS MORE LIKELY TO MOVE IN FRIDAY EVENING. RC //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... FRIDAY NIGHT...SHRA LIKELY. MVFR/IFR CIGS PSBL. SATURDAY...VFR. GUSTY NW WINDS IN THE MORNING. SUNDAY...VFR. MONDAY...CHC SHRA DURING THE DAY. MVFR CIGS PSBL. TUESDAY AND WEDNESDAY...VFR KMD && .MARINE... 356 AM CDT STRONG EARLY FALL LOW PRESSURE SYSTEM HAS KICKED OUT TO THE NORTHEAST EARLY THIS MORNING AND WILL CONTINUE ITS TREK NORTHEAST THROUGH QUEBEC OVER THE COMING DAYS. THIS SYSTEM COMBINED WITH A STRONG COLD FRONT HAS LED TO 40-45 KT GALES EARLY THIS MORNING...AND IN SPITE OF THE BUOYS SHOWING A TREND DOWNWARD...STILL SEEING SHIP OBS OF 40 KT ALONG THE WEST HALF OF LAKE. AS THE LOW MOVES OUT OF THE AREA...THE LINGERING GRADIENT WILL CONTINUE TO EASE...THUS GALE FORCE GUSTS SHOULD LARGELY BE DONE BY LATE MORNING. ALSO...WITH HIGH PRESSURE BUILDING INTO THE PLAINS...THIS WILL MAINTAIN A FETCH OF NORTHERLY WINDS DOWN THE LAKE AND KEEP WAVES ELEVATED THROUGH THE REST OF THE WEEK. A SECONDARY COLD FRONT WILL PASS THROUGH THE LAKE FRIDAY NIGHT AND WILL REINFORCE THE GUSTY NORTHERLY WINDS ON THE SOUTHERN HALF OF THE LAKE AS A WEAK LOW DEVELOPS AHEAD OF THE FRONT. AT THIS POINT WAVES WOULD HAVE BEEN GRADUALLY SUBSIDING DUE TO A WEAKENING WIND FIELD...SO THIS FRONT WILL REBUILD WAVES AGAIN...ESPECIALLY ALONG THE INDIANA SHORELINE. THE HIGH WILL THEN BUILD OVERHEAD FOR THE WEEKEND. KMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014 UNTIL 5 PM SATURDAY. IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 5 PM SATURDAY. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 10 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1241 PM CDT Thu Sep 11 2014 .UPDATE... ISSUED AT 1057 AM CDT THU SEP 11 2014 Northerly winds and cooler temperatures advecting into the area this morning under cloudy skies. Very little clearing anticipated today as any clearing on sat imagery is well off to the NW. Sun may cause a few breaks in the clouds by later this afternoon/evening. Forecast going well and no updates are anticipated at this time. && .SHORT TERM...(Today) ISSUED AT 229 AM CDT THU SEP 11 2014 07z/1am surface analysis shows cold front settling southward toward the Ohio River, with all its associated precip now south of the KILX CWA. Behind the boundary, extensive low cloud cover is noted on IR satellite imagery across Illinois northward into Wisconsin/Minnesota. With northerly winds expected to prevail throughout the day, think clouds will remain in place, especially given presence of very strong inversion at around 900mb. Models have different opinions concerning sky cover today, with MAV guidance indicating partial clearing and MET keeping conditions overcast. Given current satellite imagery and developing inversion, think the pessimistic MET solution is the way to go. As a result, have increased sky cover to go with a mostly cloudy forecast today. Have also lowered high temps due to clouds and strong CAA, with readings only rising into the lower to middle 60s. && .LONG TERM...(Tonight through Wednesday) ISSUED AT 229 AM CDT THU SEP 11 2014 Another unseasonably cool day is on tap for Friday as N/NE flow continues and skies remain partly to mostly cloudy. 500mb trough currently over the Northern Rockies will track southeastward, with the trough axis passing through Illinois Friday night. As has been advertised for the past several model runs, clouds and perhaps a few showers will accompany the trough, although models differ on how much precip may occur. NAM continues to be rather aggressive with its QPF, while both the GFS and ECMWF are drier and more diurnally driven. Given dry airmass in place ahead of this feature, prefer the GFS/ECMWF consensus here. Have introduced chance PoPs across the western half of the CWA Friday afternoon as the wave approaches, but have dropped PoPs to just slights Friday night as daytime instability diminishes and lapse rates become less steep. Once the Friday night trough passes, strong Canadian high pressure will provide cool and dry conditions this weekend. Temperatures will begin to slowly moderate through the period, with highs reaching the upper 60s and lower 70s by Sunday. After that, the next northern stream short-wave will arrive early next week, with the 00z Sep 11 models now in better agreement concerning its timing. With fairly robust wave arriving on Monday, think clouds and scattered showers are a good bet. This feature will quickly track off to the east, resulting in a return to dry weather for Tuesday and Wednesday. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) ISSUED AT 1234 PM CDT THU SEP 11 2014 Not much in the way of a change in the forecast. MVFR continuing, with some IFR conditions still possible today as cigs are right on the cusp btwn two categories above and below 1kft. Some breaks in the clouds are still well to the west and northwest. Models are breaking between some drying out of the low levels and the NAM holding on to the higher RH below 850mb. HRRR keeping MVFR through the day with some breaks approaching PIA, but certainly not predominant and will amend accordingly should the sun break through. However, the HRRR going into the evening hours starts to drop the cigs once again, with IFR very near. Not going that pessimistic just yet, but not clearing the MVFR through the end of the fcst pd. North/northeast winds throughout. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HJS SHORT TERM...BARNES LONG TERM...BARNES AVIATION...HJS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
250 PM CDT THU SEP 11 2014 ...UPDATED LONG TERM SECTION... .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 157 PM CDT THU SEP 11 2014 STATUS LINGERING ACROSS MOST OF SOUTHWEST AND WESTERN KANSAS EARLY THIS AFTERNOON HAS REDUCED THE CHANCE FOR SURFACE BASED CONVECTION LATE TODAY. AT THIS TIME HOWEVER A FEW SCATTERED ELEVATED SHOWERS OR EVEN AN ISOLATED THUNDERSTORM WILL STILL BE POSSIBLE THROUGH EARLY EVENING ACROSS FAR WESTERN KANSAS, MAINLY WEST OF HIGHWAY 83. THIS IS BASED ON THE MOISTURE AND WARM AIR ADVECTION FORECAST AROUND THE 700MB LEVEL AND ELEVATED CAPE VALUES BETWEEN 00Z AND 03Z FRIDAY FROM THE NAM AND ARW. MODELS TODAY REMAINED IN GOOD AGREEMENT WITH A REINFORCEMENT OF COLDER AIR CROSSING WESTERN KANSAS LATE TONIGHT AS A COLD DOME OF HIGH PRESSURE, LOCATED OVER EASTERN MONTANA AT 12Z THURSDAY, MOVES SOUTHEAST INTO EASTERN WYOMING AND WESTERN NEBRASKA BY 12Z FRIDAY. AS THIS COLDER AIR INVADES WESTERN KANSAS....GUSTY NORTHEAST WINDS WILL DEVELOP. BASED ON THE MEAN WINDS FROM THE SURFACE TO 0.5KM WINDS, 925MB TO 850MB WINDS AND WITH 12Z NAM BUFR SOUNDINGS IT APPEARS WIND SPEEDS WILL BRIEFLY APPROACH ADVISORY CRITERIA BETWEEN 09Z AND 15Z FRIDAY WEST OF HIGHWAY 83. GIVEN THE COLD AIR ADVECTION ADVERTISED BY THE NAM AND GFS THE TEMPERATURES OVERNIGHT WILL CONTINUE TO FAVOR THE PREVIOUS FORECAST WHICH WAS A FEW DEGREES BELOW THE COOLER GUIDANCE DESPITE THE CLOUD COVER EXPECTED. LOWS TONIGHT ARE STILL EXPECTED TO RANGE FROM THE LOWER 40S TO NEAR 50 DEGREES. WIDESPREAD RAINFALL WILL IMPROVE ACROSS ALL OF WESTERN KANSAS LATER TONIGHT AND THEN CONTINUE THROUGH FRIDAY AS A MID LEVEL BAROCLINIC ZONE AHEAD OF AN UPPER LEVEL TROUGH CROSSES THE CENTRAL PLAINS. THE BETTER FORCING FOR THIS PRECIPITATION TONIGHT AND FRIDAY WILL OCCUR ALONG A BAND OF 850MB TO 700MB FRONTOGENISIS THAT WILL MOVE FROM WEST CENTRAL KANSAS AT 06Z FRIDAY TO SOUTH CENTRAL KANSAS BETWEEN 15Z AND 18Z FRIDAY. AFTER 18Z THE PRECIPITATION IS EXPECTED TO TAPER OFF FROM NORTHWEST TO SOUTHEAST AS THE MID LEVEL BAROCLINIC ZONE MOVES INTO CENTRAL KANSAS AND NORTHERN OKLAHOMA. THERE MAY ALSO BE SOME CLEARING NEAR THE COLORADO BORDER LATE IN THE DAY FRIDAY AS SUBSIDENCE DEVELOPS BEHIND THE UPPER LEVEL TROUGH THAT WILL BE CROSSING NEBRASKA AND KANSAS DURING THE DAY ON FRIDAY. LITTLE DIURNAL CHANGE IN TEMPERATURES WILL OCCUR ACROSS WESTERN KANSAS BETWEEN THURSDAY NIGHT LOWS AND HIGHS FRIDAY AFTERNOON BASED ON CLOUD COVER AND PRECIPITATION CHANCES THROUGH MUCH OF THE DAY. TAKING THIS INTO ACCOUNT WILL STAY CLOSE TO THE LATEST GUIDANCE ACROSS PORTIONS WESTERN KANSAS WHERE SOME BREAKS OF SUN WILL BE POSSIBLE LATE FRIDAY. WILL UNDERCUT GUIDANCE FURTHER EAST. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 318 AM CDT THU SEP 11 2014 FRIDAY AND SATURDAY WILL BE RECOVERY DAYS FROM THE RELATIVELY COOL AND CLOUDY CONDITIONS FROM THE PREVIOUS WAVE. THE WAVE WILL BE EXITING THE REGION ON FRIDAY EVENING, LEAVING IN IT`S WAKE ZONAL WINDS ALOFT AND INCREASINGLY COOL AND DRY BOUNDARY LAYER ON SATURDAY. EARLY SATURDAY MORNING, TEMPERATURES WILL PROBABLY PLUMMET INTO THE UPPER 30S IN SOME AREAS OF THE WEST CENTRAL AND CENTRAL COUNTIES WHERE LIGHT WINDS LOW DEW POINTS AND CLEARING SKIES FAVOR EFFICIENT LONGWAVE RADIATIONAL COOLING. HOWEVER TEMPERATURES WILL STILL WARM AT THE SURFACE DUE TO INCREASED INSOLATION WITH TEMPERATES RISING THROUGH THE 60S BY SATURDAY AFTERNOON, AND A LARGER JUMP ON STRONGER SOUTHERLY /SOUTHWEST WINDS ON SUNDAY INTO THE LOW TO MID 80S IN SOME AREAS. BY SUNDAY NIGHT OR EARLY MONDAY ALL OF THE MODELS BEGIN TO SHOW THE NEXT PV ANOMALY MOVING THROUGH THE FLOW ACROSS THE GREAT LAKE REGION WITH A WEAK TROUGH/DEFORMATION ZONE EXTENDING SOUTH THROUGH THE CENTRAL PLANS IN VICINITY OF CENTRAL KANSAS. POPS HAVE CONTINUED TO BE CARRIED FOR THUNDERSTORM CHANCES IN THIS PERIOD AS THE GFS MODEL SOUNDINGS DO APPEAR TO SUPPORT THE POTENTIAL WITH NEAR SATURATED PROFILES NEAR THE LCL AND JUST BELOW LFC MONDAY. BEYOND THAT, CONVECTION COULD ALSO OCCUR ANY GIVEN DAY AS WEAK SOUTHERLY 850 MB MOISTURE TRANSPORT SIGNALS CONTINUE ACROSS THE HIGH PLAINS REGION TUESDAY AND WEDNESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1208 PM CDT THU SEP 11 2014 BUFR SOUNDINGS AND HRRR BOTH IN GOOD AGREEMENT WITH IFR AND LIFR CEILINGS GRADUALLY IMPROVING THROUGH THE EARLY AFTERNOON WITH A BRIEF PERIOD OF VFR CONDITIONS DEVELOPING AT GCK AND DDC AFTER 21Z. CLOUD BASES WILL THEN LOWER ONCE AGAIN BACK INTO THE 700 TO 1500FT AGL LEVEL AFTER 00Z FRIDAY AS MORE HUMID AIR RETURNS TO SOUTHWEST KANSAS. IN ADDITION TO THE LOWERING CEILINGS EARLY TONIGHT PERIODS OF LIGHT RAIN AND/OR DRIZZLE CAN BE EXPECTED LATE TONIGHT THROUGH EARLY FRIDAY. NORTHEASTERLY WINDS AT 15 TO 20 KNOTS THIS AFTERNOON WILL BECOME MORE NORTHERLY AFTER 06Z AND THEN INCREASE TO 20 TO NEAR 25 KNOTS. && .PRELIMINARY POINT TEMPS/POPS... DDC 46 53 40 65 / 90 80 0 0 GCK 43 50 38 67 / 90 80 0 0 EHA 42 51 43 71 / 90 80 0 0 LBL 47 54 42 69 / 90 80 0 0 HYS 42 52 38 64 / 90 80 0 0 P28 52 58 43 67 / 40 60 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BURGERT LONG TERM...MR AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
200 PM CDT THU SEP 11 2014 ...UPDATED SHORT TERM DISCUSSION... .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 157 PM CDT THU SEP 11 2014 STATUS LINGERING ACROSS MOST OF SOUTHWEST AND WESTERN KANSAS EARLY THIS AFTERNOON HAS REDUCED THE CHANCE FOR SURFACE BASED CONVECTION LATE TODAY. AT THIS TIME HOWEVER A FEW SCATTERED ELEVATED SHOWERS OR EVEN AN ISOLATED THUNDERSTORM WILL STILL BE POSSIBLE THROUGH EARLY EVENING ACROSS FAR WESTERN KANSAS, MAINLY WEST OF HIGHWAY 83. THIS IS BASED ON THE MOISTURE AND WARM AIR ADVECTION FORECAST AROUND THE 700MB LEVEL AND ELEVATED CAPE VALUES BETWEEN 00Z AND 03Z FRIDAY FROM THE NAM AND ARW. MODELS TODAY REMAINED IN GOOD AGREEMENT WITH A REINFORCEMENT OF COLDER AIR CROSSING WESTERN KANSAS LATE TONIGHT AS A COLD DOME OF HIGH PRESSURE, LOCATED OVER EASTERN MONTANA AT 12Z THURSDAY, MOVES SOUTHEAST INTO EASTERN WYOMING AND WESTERN NEBRASKA BY 12Z FRIDAY. AS THIS COLDER AIR INVADES WESTERN KANSAS....GUSTY NORTHEAST WINDS WILL DEVELOP. BASED ON THE MEAN WINDS FROM THE SURFACE TO 0.5KM WINDS, 925MB TO 850MB WINDS AND WITH 12Z NAM BUFR SOUNDINGS IT APPEARS WIND SPEEDS WILL BRIEFLY APPROACH ADVISORY CRITERIA BETWEEN 09Z AND 15Z FRIDAY WEST OF HIGHWAY 83. GIVEN THE COLD AIR ADVECTION ADVERTISED BY THE NAM AND GFS THE TEMPERATURES OVERNIGHT WILL CONTINUE TO FAVOR THE PREVIOUS FORECAST WHICH WAS A FEW DEGREES BELOW THE COOLER GUIDANCE DESPITE THE CLOUD COVER EXPECTED. LOWS TONIGHT ARE STILL EXPECTED TO RANGE FROM THE LOWER 40S TO NEAR 50 DEGREES. WIDESPREAD RAINFALL WILL IMPROVE ACROSS ALL OF WESTERN KANSAS LATER TONIGHT AND THEN CONTINUE THROUGH FRIDAY AS A MID LEVEL BAROCLINIC ZONE AHEAD OF AN UPPER LEVEL TROUGH CROSSES THE CENTRAL PLAINS. THE BETTER FORCING FOR THIS PRECIPITATION TONIGHT AND FRIDAY WILL OCCUR ALONG A BAND OF 850MB TO 700MB FRONTOGENISIS THAT WILL MOVE FROM WEST CENTRAL KANSAS AT 06Z FRIDAY TO SOUTH CENTRAL KANSAS BETWEEN 15Z AND 18Z FRIDAY. AFTER 18Z THE PRECIPITATION IS EXPECTED TO TAPER OFF FROM NORTHWEST TO SOUTHEAST AS THE MID LEVEL BAROCLINIC ZONE MOVES INTO CENTRAL KANSAS AND NORTHERN OKLAHOMA. THERE MAY ALSO BE SOME CLEARING NEAR THE COLORADO BORDER LATE IN THE DAY FRIDAY AS SUBSIDENCE DEVELOPS BEHIND THE UPPER LEVEL TROUGH THAT WILL BE CROSSING NEBRASKA AND KANSAS DURING THE DAY ON FRIDAY. LITTLE DIURNAL CHANGE IN TEMPERATURES WILL OCCUR ACROSS WESTERN KANSAS BETWEEN THURSDAY NIGHT LOWS AND HIGHS FRIDAY AFTERNOON BASED ON CLOUD COVER AND PRECIPITATION CHANCES THROUGH MUCH OF THE DAY. TAKING THIS INTO ACCOUNT WILL STAY CLOSE TO THE LATEST GUIDANCE ACROSS PORTIONS WESTERN KANSAS WHERE SOME BREAKS OF SUN WILL BE POSSIBLE LATE FRIDAY. WILL UNDERCUT GUIDANCE FURTHER EAST. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 318 AM CDT THU SEP 11 2014 FRIDAY WILL BE COOL AND MOIST, WITH LIGHT RAIN LIKELY. FRIDAY WILL BE IN A POST FRONTAL REGIME, WITH COOL HIGH PRESSURE BUILDING IN FROM THE NORTHWEST. THE SURFACE FLOW WILL BE UPSLOPE WITH NORTHEAST TO EASTERLY WINDS AT 10 TO 20 MPH. CLOUDS WILL BE THICKEST IN THE MORNING, BUT STILL PREVALENT IN THE AFTERNOON. MAX TEMPS WILL GENERALLY BE IN THE 50S, BUT I ONLY EXPECT LIGHT RAIN WITH 0.05 TO 0.10 INCH ACCUMULATION. THE HIGH PRESSURE WILL BEGIN TO DOMINATE FRIDAY EVENING, LEADING TO CLEAR SKIES OVERNIGHT. THE COOL AIR WILL FILTRATE IN FROM THE NORTHWEST, AND FROST MAY BE POSSIBLE IN OUR EXTREME NORTHWESTERN COUNTIES OF TREGO, AND NORTHERN LANE AND SCOTT COUNTIES SATURDAY MORNING. AS THAT TIME FRAME APPROACHES, WE WILL NEED TO LOOK INTO A POSSIBLE WATCH OR REFINE THE AREA WHERE FROST MAY OCCUR. AFTER THE FALL-LIKE WEATHER ON FRIDAY, SATURDAY AND SUNDAY WILL SHOW A GRADUAL WARM UP, WITH HIGHS REACHING THE MID 60S TO LOWER 70S ON SATURDAY, AND BOUNDING UPWARD TO THE UPPER 70S TO LOWER 80S BY SUNDAY. A COLD FRONT WILL PLOW THROUGH TO THE SOUTHEAST ON MONDAY AFTERNOON, BRINGING A CHANCE FOR THUNDERSTORMS TO OUR SOUTHEAST-MOST ZONES, PRIMARILY IN PRATT AND BARBER COUNTIES. AN UPPER LEVEL WAVE WILL COME THROUGH IN THE FLOW MONDAY NIGHT, GIVING MOST OF THE CWA A 20 TO 30 PERCENT CHANCE FOR THUNDERSTORMS. A LEE SIDE TROUGH WILL BE IN WESTERN KANSAS TUESDAY AND WEDNESDAY, AND SLIGHT CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS WILL EXIST ACROSS MOST OF OUR FORECAST AREA, MAINLY THE EAST. WEDNESDAY WILL SEE A RETURN TO A WARM SOUTHWEST FLOW, AND HIGH TEMPERATURES WILL RESPOND LIKEWISE WITH VALUES IN THE LOWER 80S NORTH OF I-70 AND THE MIDDLE 80S SOUTHWEST A LINE FROM GARDEN CITY TO DODGE CITY TO MEDICINE LODGE. WINDS THROUGH THE EXTENDED DO NOT LOOK TOO STRONG, EXCEPT AHEAD OF THE FRONT ON MONDAY, AND THEN AGAIN BEHIND THE FRONT ON TUESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1208 PM CDT THU SEP 11 2014 BUFR SOUNDINGS AND HRRR BOTH IN GOOD AGREEMENT WITH IFR AND LIFR CEILINGS GRADUALLY IMPROVING THROUGH THE EARLY AFTERNOON WITH A BRIEF PERIOD OF VFR CONDITIONS DEVELOPING AT GCK AND DDC AFTER 21Z. CLOUD BASES WILL THEN LOWER ONCE AGAIN BACK INTO THE 700 TO 1500FT AGL LEVEL AFTER 00Z FRIDAY AS MORE HUMID AIR RETURNS TO SOUTHWEST KANSAS. IN ADDITION TO THE LOWERING CEILINGS EARLY TONIGHT PERIODS OF LIGHT RAIN AND/OR DRIZZLE CAN BE EXPECTED LATE TONIGHT THROUGH EARLY FRIDAY. NORTHEASTERLY WINDS AT 15 TO 20 KNOTS THIS AFTERNOON WILL BECOME MORE NORTHERLY AFTER 06Z AND THEN INCREASE TO 20 TO NEAR 25 KNOTS. && .PRELIMINARY POINT TEMPS/POPS... DDC 45 53 40 65 / 90 80 0 0 GCK 42 50 38 67 / 90 80 0 0 EHA 45 51 43 71 / 90 80 0 0 LBL 48 54 42 69 / 90 80 0 0 HYS 42 52 38 64 / 90 80 0 0 P28 50 58 43 67 / 40 60 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BURGERT LONG TERM...BURKE AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1212 PM CDT THU SEP 11 2014 ...UPDATED SYNOPSIS AND AVIATION DISCUSSION... .SYNOPSIS... ISSUED AT 1208 PM CDT THU SEP 11 2014 AT 12Z THURSDAY A -28C 500MB LOW WAS LOCATED OVER WESTERN MONTANA WITH A +100 KNOT 300MB JET EXTENDING FROM THE BASED OF THIS UPPER LOW NEAR SOUTHERN IDAHO EASTWARD INTO SOUTH DAKOTA. A 700MB BAROCLINIC ZONE STRETCHED FROM EASTERN IDAHO TO SOUTHEAST WYOMING AND ACROSS CENTRAL NEBRASKA. THIS IS ALSO WHERE AN AREA OF HIGHER 850MB AND 700MB MOISTURE APPEARS TO BE LOCATED EARLIER THIS MORNING. AN 850MB COLD FRONT WAS LOCATED FROM SOUTHEAST COLORADO TO NORTH CENTRAL KANSAS WITH A MOISTURE UPSLOPE FLOW FROM THE SURFACE TO THE 850MB LEVEL JUST NORTH OF THIS BOUNDARY. DODGE CITY SOUNDINGS HAD THE DEPTH OF THIS LOW LEVEL MOISTURE AROUND 3000FT AGL. A ENFORCEMENT OF COOLER AIR AT 850MB LEVEL APPEARS TO EXTEND FROM SOUTHEAST WYOMING TO SOUTHERN IOWA. 850MB TEMPERATURES THIS MORNING SOUTH OF THIS BOUNDARY RANGE FROM +8C AT TOPEKA TO +11C AT DODGE CITY WHILE NORTH OF THIS BOUNDARY RAPID CITY REPORTED -2C AND ABERDEEN REPORTED -1C. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 112 AM CDT THU SEP 11 2014 SHORT TERM MODELS INDICATE AN UPPER LEVEL SHORTWAVE TROUGH DIGGING SOUTHEAST ACROSS THE NORTHERN ROCKIES TODAY AND PUSHING FURTHER SOUTHEAST INTO THE WESTERN HIGH PLAINS TONIGHT SETTING UP PRECIP CHANCES ACROSS NEBRASKA SOUTHWARD INTO PORTIONS OF WESTERN KANSAS. AS THE SHORTWAVE APPROACHES THIS EVENING, A SERIES OF H5 VORT MAXIMA WILL BEGIN TO EJECT EASTWARD OUT OF THE COLORADO ROCKIES INTO THE HIGH PLAINS OF EASTERN COLORADO AND WESTERN KANSAS. MEANWHILE, AN ATTENDANT COLD FRONT TO THE SHORTWAVE WILL BEGIN TO PUSH SOUTHWARD ACROSS WESTERN KANSAS LATE THIS EVENING INTO EARLY FRIDAY MORNING. OVERNIGHT, DYNAMIC SUPPORT ALOFT WILL BECOME MORE FAVORABLE AS THE RIGHT FRONT ENTRANCE REGION TO A +90KT JET EXITING THE APPROACHING TROUGH AXIS SHIFTS SOUTHWARD INTO WESTERN KANSAS. AS A RESULT, RAIN CHANCES WILL INCREASE ACROSS WESTERN KANSAS THIS EVENING, SPREADING SOUTH AND EAST ACROSS THE REGION OVERNIGHT. A FEW ISOLATED THUNDERSTORMS WILL BE POSSIBLE ACROSS EXTREME SOUTHWEST KANSAS THIS EVENING WHERE SOME INCREASED INSTABILITY AND MORE FAVORABLE VERTICAL SHEAR PROFILES WILL EXIST IN A SOUTHEASTERLY UPSLOPE FLOW. HOWEVER, NAM/GFS MODEL SOUNDINGS INDICATE LIMITED INSTABILITY WITH CAPE VALUES REMAINING WELL UNDER 1000 J/KG. THIS WILL RESTRICT THE POTENTIAL FOR SEVERE STORMS ACROSS SOUTHWEST KANSAS. TEMPERATURES WILL BE WELL BELOW NORMAL TODAY AS COOLER AIR FILTERS SOUTHWARD INTO WESTERN KANSAS AHEAD OF A BROAD SURFACE HIGH MOVING SOUTHEASTWARD OUT OF THE NORTHERN ROCKIES INTO THE HIGH PLAINS OF EASTERN WYOMING AND WESTERN NEBRASKA. THE NAM AND GFS SHOW H85 TEMPERATURES FALLING BELOW 10C ACROSS CENTRAL KANSAS NEAR THE I-70 CORRIDOR BY THIS AFTERNOON WITH THE MID TO UPPER TEENS(C) ACROSS EXTREME SOUTHWEST KANSAS WITHIN A SOUTHEAST UPSLOPE FLOW. ADDITIONALLY, HIGH TEMPERATURES MAY BE HINDERED TODAY DEPENDING ON HOW FAR SOUTH LOW LEVEL STRATUS MOVING OUT OF NEBRASKA THIS MORNING PUSHES INTO SOUTHWEST KANSAS, NOT TO MENTION HOW LONG IT MAY LAST. THE HRRR SUGGESTS THE STRATUS DECK PERSISTING THROUGH AT LEAST MID DAY, PARTICULARLY ACROSS CENTRAL KANSAS IN THE VICINITY OF THE I-70 CORRIDOR. BECAUSE OF THIS, HIGHS MAY STRUGGLE TO REACH THE 60S(F) IN CENTRAL KANSAS WITH THE LOWER TO MID 70S(F) POSSIBLE CLOSER TO THE OKLAHOMA BORDER, ESPECIALLY IN EXTREME SOUTHWEST KANSAS. A SECONDARY PUSH OF COLDER AIR BEHIND YET ANOTHER COLD FRONT PUSHING ACROSS WESTERN KANSAS EARLY FRIDAY MORNING WILL LIKELY DROP LOWS DOWN INTO THE 40S(F) ACROSS MUCH OF CENTRAL AND SOUTHWEST KANSAS TONIGHT. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 318 AM CDT THU SEP 11 2014 FRIDAY WILL BE COOL AND MOIST, WITH LIGHT RAIN LIKELY. FRIDAY WILL BE IN A POST FRONTAL REGIME, WITH COOL HIGH PRESSURE BUILDING IN FROM THE NORTHWEST. THE SURFACE FLOW WILL BE UPSLOPE WITH NORTHEAST TO EASTERLY WINDS AT 10 TO 20 MPH. CLOUDS WILL BE THICKEST IN THE MORNING, BUT STILL PREVALENT IN THE AFTERNOON. MAX TEMPS WILL GENERALLY BE IN THE 50S, BUT I ONLY EXPECT LIGHT RAIN WITH 0.05 TO 0.10 INCH ACCUMULATION. THE HIGH PRESSURE WILL BEGIN TO DOMINATE FRIDAY EVENING, LEADING TO CLEAR SKIES OVERNIGHT. THE COOL AIR WILL FILTRATE IN FROM THE NORTHWEST, AND FROST MAY BE POSSIBLE IN OUR EXTREME NORTHWESTERN COUNTIES OF TREGO, AND NORTHERN LANE AND SCOTT COUNTIES SATURDAY MORNING. AS THAT TIME FRAME APPROACHES, WE WILL NEED TO LOOK INTO A POSSIBLE WATCH OR REFINE THE AREA WHERE FROST MAY OCCUR. AFTER THE FALL-LIKE WEATHER ON FRIDAY, SATURDAY AND SUNDAY WILL SHOW A GRADUAL WARM UP, WITH HIGHS REACHING THE MID 60S TO LOWER 70S ON SATURDAY, AND BOUNDING UPWARD TO THE UPPER 70S TO LOWER 80S BY SUNDAY. A COLD FRONT WILL PLOW THROUGH TO THE SOUTHEAST ON MONDAY AFTERNOON, BRINGING A CHANCE FOR THUNDERSTORMS TO OUR SOUTHEAST-MOST ZONES, PRIMARILY IN PRATT AND BARBER COUNTIES. AN UPPER LEVEL WAVE WILL COME THROUGH IN THE FLOW MONDAY NIGHT, GIVING MOST OF THE CWA A 20 TO 30 PERCENT CHANCE FOR THUNDERSTORMS. A LEE SIDE TROUGH WILL BE IN WESTERN KANSAS TUESDAY AND WEDNESDAY, AND SLIGHT CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS WILL EXIST ACROSS MOST OF OUR FORECAST AREA, MAINLY THE EAST. WEDNESDAY WILL SEE A RETURN TO A WARM SOUTHWEST FLOW, AND HIGH TEMPERATURES WILL RESPOND LIKEWISE WITH VALUES IN THE LOWER 80S NORTH OF I-70 AND THE MIDDLE 80S SOUTHWEST A LINE FROM GARDEN CITY TO DODGE CITY TO MEDICINE LODGE. WINDS THROUGH THE EXTENDED DO NOT LOOK TOO STRONG, EXCEPT AHEAD OF THE FRONT ON MONDAY, AND THEN AGAIN BEHIND THE FRONT ON TUESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1208 PM CDT THU SEP 11 2014 BUFR SOUNDINGS AND HRRR BOTH IN GOOD AGREEMENT WITH IFR AND LIFR CEILINGS GRADUALLY IMPROVING THROUGH THE EARLY AFTERNOON WITH A BRIEF PERIOD OF VFR CONDITIONS DEVELOPING AT GCK AND DDC AFTER 21Z. CLOUD BASES WILL THEN LOWER ONCE AGAIN BACK INTO THE 700 TO 1500FT AGL LEVEL AFTER 00Z FRIDAY AS MORE HUMID AIR RETURNS TO SOUTHWEST KANSAS. IN ADDITION TO THE LOWERING CEILINGS EARLY TONIGHT PERIODS OF LIGHT RAIN AND/OR DRIZZLE CAN BE EXPECTED LATE TONIGHT THROUGH EARLY FRIDAY. NORTHEASTERLY WINDS AT 15 TO 20 KNOTS THIS AFTERNOON WILL BECOME MORE NORTHERLY AFTER 06Z AND THEN INCREASE TO 20 TO NEAR 25 KNOTS. && .PRELIMINARY POINT TEMPS/POPS... DDC 60 45 53 40 / 0 90 80 0 GCK 59 42 50 38 / 10 90 80 0 EHA 69 45 51 43 / 20 90 90 0 LBL 65 48 54 42 / 10 90 80 0 HYS 58 42 52 38 / 10 90 80 0 P28 69 50 58 43 / 0 40 60 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BURGERT SHORT TERM...JJOHNSON LONG TERM...BURKE AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
607 AM CDT THU SEP 11 2014 ...UPDATE FOR THE AVIATION DISCUSSION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 112 AM CDT THU SEP 11 2014 SHORT TERM MODELS INDICATE AN UPPER LEVEL SHORTWAVE TROUGH DIGGING SOUTHEAST ACROSS THE NORTHERN ROCKIES TODAY AND PUSHING FURTHER SOUTHEAST INTO THE WESTERN HIGH PLAINS TONIGHT SETTING UP PRECIP CHANCES ACROSS NEBRASKA SOUTHWARD INTO PORTIONS OF WESTERN KANSAS. AS THE SHORTWAVE APPROACHES THIS EVENING, A SERIES OF H5 VORT MAXIMA WILL BEGIN TO EJECT EASTWARD OUT OF THE COLORADO ROCKIES INTO THE HIGH PLAINS OF EASTERN COLORADO AND WESTERN KANSAS. MEANWHILE, AN ATTENDANT COLD FRONT TO THE SHORTWAVE WILL BEGIN TO PUSH SOUTHWARD ACROSS WESTERN KANSAS LATE THIS EVENING INTO EARLY FRIDAY MORNING. OVERNIGHT, DYNAMIC SUPPORT ALOFT WILL BECOME MORE FAVORABLE AS THE RIGHT FRONT ENTRANCE REGION TO A +90KT JET EXITING THE APPROACHING TROUGH AXIS SHIFTS SOUTHWARD INTO WESTERN KANSAS. AS A RESULT, RAIN CHANCES WILL INCREASE ACROSS WESTERN KANSAS THIS EVENING, SPREADING SOUTH AND EAST ACROSS THE REGION OVERNIGHT. A FEW ISOLATED THUNDERSTORMS WILL BE POSSIBLE ACROSS EXTREME SOUTHWEST KANSAS THIS EVENING WHERE SOME INCREASED INSTABILITY AND MORE FAVORABLE VERTICAL SHEAR PROFILES WILL EXIST IN A SOUTHEASTERLY UPSLOPE FLOW. HOWEVER, NAM/GFS MODEL SOUNDINGS INDICATE LIMITED INSTABILITY WITH CAPE VALUES REMAINING WELL UNDER 1000 J/KG. THIS WILL RESTRICT THE POTENTIAL FOR SEVERE STORMS ACROSS SOUTHWEST KANSAS. TEMPERATURES WILL BE WELL BELOW NORMAL TODAY AS COOLER AIR FILTERS SOUTHWARD INTO WESTERN KANSAS AHEAD OF A BROAD SURFACE HIGH MOVING SOUTHEASTWARD OUT OF THE NORTHERN ROCKIES INTO THE HIGH PLAINS OF EASTERN WYOMING AND WESTERN NEBRASKA. THE NAM AND GFS SHOW H85 TEMPERATURES FALLING BELOW 10C ACROSS CENTRAL KANSAS NEAR THE I-70 CORRIDOR BY THIS AFTERNOON WITH THE MID TO UPPER TEENS(C) ACROSS EXTREME SOUTHWEST KANSAS WITHIN A SOUTHEAST UPSLOPE FLOW. ADDITIONALLY, HIGH TEMPERATURES MAY BE HINDERED TODAY DEPENDING ON HOW FAR SOUTH LOW LEVEL STRATUS MOVING OUT OF NEBRASKA THIS MORNING PUSHES INTO SOUTHWEST KANSAS, NOT TO MENTION HOW LONG IT MAY LAST. THE HRRR SUGGESTS THE STRATUS DECK PERSISTING THROUGH AT LEAST MID DAY, PARTICULARLY ACROSS CENTRAL KANSAS IN THE VICINITY OF THE I-70 CORRIDOR. BECAUSE OF THIS, HIGHS MAY STRUGGLE TO REACH THE 60S(F) IN CENTRAL KANSAS WITH THE LOWER TO MID 70S(F) POSSIBLE CLOSER TO THE OKLAHOMA BORDER, ESPECIALLY IN EXTREME SOUTHWEST KANSAS. A SECONDARY PUSH OF COLDER AIR BEHIND YET ANOTHER COLD FRONT PUSHING ACROSS WESTERN KANSAS EARLY FRIDAY MORNING WILL LIKELY DROP LOWS DOWN INTO THE 40S(F) ACROSS MUCH OF CENTRAL AND SOUTHWEST KANSAS TONIGHT. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 318 AM CDT THU SEP 11 2014 FRIDAY WILL BE COOL AND MOIST, WITH LIGHT RAIN LIKELY. FRIDAY WILL BE IN A POST FRONTAL REGIME, WITH COOL HIGH PRESSURE BUILDING IN FROM THE NORTHWEST. THE SURFACE FLOW WILL BE UPSLOPE WITH NORTHEAST TO EASTERLY WINDS AT 10 TO 20 MPH. CLOUDS WILL BE THICKEST IN THE MORNING, BUT STILL PREVALENT IN THE AFTERNOON. MAX TEMPS WILL GENERALLY BE IN THE 50S, BUT I ONLY EXPECT LIGHT RAIN WITH 0.05 TO 0.10 INCH ACCUMULATION. THE HIGH PRESSURE WILL BEGIN TO DOMINATE FRIDAY EVENING, LEADING TO CLEAR SKIES OVERNIGHT. THE COOL AIR WILL FILTRATE IN FROM THE NORTHWEST, AND FROST MAY BE POSSIBLE IN OUR EXTREME NORTHWESTERN COUNTIES OF TREGO, AND NORTHERN LANE AND SCOTT COUNTIES SATURDAY MORNING. AS THAT TIME FRAME APPROACHES, WE WILL NEED TO LOOK INTO A POSSIBLE WATCH OR REFINE THE AREA WHERE FROST MAY OCCUR. AFTER THE FALL-LIKE WEATHER ON FRIDAY, SATURDAY AND SUNDAY WILL SHOW A GRADUAL WARM UP, WITH HIGHS REACHING THE MID 60S TO LOWER 70S ON SATURDAY, AND BOUNDING UPWARD TO THE UPPER 70S TO LOWER 80S BY SUNDAY. A COLD FRONT WILL PLOW THROUGH TO THE SOUTHEAST ON MONDAY AFTERNOON, BRINGING A CHANCE FOR THUNDERSTORMS TO OUR SOUTHEAST-MOST ZONES, PRIMARILY IN PRATT AND BARBER COUNTIES. AN UPPER LEVEL WAVE WILL COME THROUGH IN THE FLOW MONDAY NIGHT, GIVING MOST OF THE CWA A 20 TO 30 PERCENT CHANCE FOR THUNDERSTORMS. A LEE SIDE TROUGH WILL BE IN WESTERN KANSAS TUESDAY AND WEDNESDAY, AND SLIGHT CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS WILL EXIST ACROSS MOST OF OUR FORECAST AREA, MAINLY THE EAST. WEDNESDAY WILL SEE A RETURN TO A WARM SOUTHWEST FLOW, AND HIGH TEMPERATURES WILL RESPOND LIKEWISE WITH VALUES IN THE LOWER 80S NORTH OF I-70 AND THE MIDDLE 80S SOUTHWEST A LINE FROM GARDEN CITY TO DODGE CITY TO MEDICINE LODGE. WINDS THROUGH THE EXTENDED DO NOT LOOK TOO STRONG, EXCEPT AHEAD OF THE FRONT ON MONDAY, AND THEN AGAIN BEHIND THE FRONT ON TUESDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 603 AM CDT THU SEP 11 2014 SETTLING HIGH PRESSURE HAS RESULTED IN LIGHT UPSLOPE, EAST- NORTHEASTERLY WINDS AT THE SURFACE. STRATUS CLOUDS AND SOME FOG FORMED IN THE MOIST, UPSLOPE FLOW. IFR CONDITIONS WILL PREVAIL UNTIL ABOUT NOON, THEN MFVR CIGS WITH VFR VSBYS ARE EXPECTED. && .PRELIMINARY POINT TEMPS/POPS... DDC 65 45 53 40 / 10 70 70 0 GCK 65 42 50 38 / 10 70 70 0 EHA 75 45 51 43 / 20 80 70 0 LBL 72 48 54 42 / 10 70 70 0 HYS 58 42 52 38 / 10 70 70 0 P28 65 50 58 43 / 10 70 70 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...JJOHNSON LONG TERM...BURKE AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
322 AM CDT THU SEP 11 2014 ...UPDATED FOR THE LONG TERM... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 112 AM CDT THU SEP 11 2014 SHORT TERM MODELS INDICATE AN UPPER LEVEL SHORTWAVE TROUGH DIGGING SOUTHEAST ACROSS THE NORTHERN ROCKIES TODAY AND PUSHING FURTHER SOUTHEAST INTO THE WESTERN HIGH PLAINS TONIGHT SETTING UP PRECIP CHANCES ACROSS NEBRASKA SOUTHWARD INTO PORTIONS OF WESTERN KANSAS. AS THE SHORTWAVE APPROACHES THIS EVENING, A SERIES OF H5 VORT MAXIMA WILL BEGIN TO EJECT EASTWARD OUT OF THE COLORADO ROCKIES INTO THE HIGH PLAINS OF EASTERN COLORADO AND WESTERN KANSAS. MEANWHILE, AN ATTENDANT COLD FRONT TO THE SHORTWAVE WILL BEGIN TO PUSH SOUTHWARD ACROSS WESTERN KANSAS LATE THIS EVENING INTO EARLY FRIDAY MORNING. OVERNIGHT, DYNAMIC SUPPORT ALOFT WILL BECOME MORE FAVORABLE AS THE RIGHT FRONT ENTRANCE REGION TO A +90KT JET EXITING THE APPROACHING TROUGH AXIS SHIFTS SOUTHWARD INTO WESTERN KANSAS. AS A RESULT, RAIN CHANCES WILL INCREASE ACROSS WESTERN KANSAS THIS EVENING, SPREADING SOUTH AND EAST ACROSS THE REGION OVERNIGHT. A FEW ISOLATED THUNDERSTORMS WILL BE POSSIBLE ACROSS EXTREME SOUTHWEST KANSAS THIS EVENING WHERE SOME INCREASED INSTABILITY AND MORE FAVORABLE VERTICAL SHEAR PROFILES WILL EXIST IN A SOUTHEASTERLY UPSLOPE FLOW. HOWEVER, NAM/GFS MODEL SOUNDINGS INDICATE LIMITED INSTABILITY WITH CAPE VALUES REMAINING WELL UNDER 1000 J/KG. THIS WILL RESTRICT THE POTENTIAL FOR SEVERE STORMS ACROSS SOUTHWEST KANSAS. TEMPERATURES WILL BE WELL BELOW NORMAL TODAY AS COOLER AIR FILTERS SOUTHWARD INTO WESTERN KANSAS AHEAD OF A BROAD SURFACE HIGH MOVING SOUTHEASTWARD OUT OF THE NORTHERN ROCKIES INTO THE HIGH PLAINS OF EASTERN WYOMING AND WESTERN NEBRASKA. THE NAM AND GFS SHOW H85 TEMPERATURES FALLING BELOW 10C ACROSS CENTRAL KANSAS NEAR THE I-70 CORRIDOR BY THIS AFTERNOON WITH THE MID TO UPPER TEENS(C) ACROSS EXTREME SOUTHWEST KANSAS WITHIN A SOUTHEAST UPSLOPE FLOW. ADDITIONALLY, HIGH TEMPERATURES MAY BE HINDERED TODAY DEPENDING ON HOW FAR SOUTH LOW LEVEL STRATUS MOVING OUT OF NEBRASKA THIS MORNING PUSHES INTO SOUTHWEST KANSAS, NOT TO MENTION HOW LONG IT MAY LAST. THE HRRR SUGGESTS THE STRATUS DECK PERSISTING THROUGH AT LEAST MID DAY, PARTICULARLY ACROSS CENTRAL KANSAS IN THE VICINITY OF THE I-70 CORRIDOR. BECAUSE OF THIS, HIGHS MAY STRUGGLE TO REACH THE 60S(F) IN CENTRAL KANSAS WITH THE LOWER TO MID 70S(F) POSSIBLE CLOSER TO THE OKLAHOMA BORDER, ESPECIALLY IN EXTREME SOUTHWEST KANSAS. A SECONDARY PUSH OF COLDER AIR BEHIND YET ANOTHER COLD FRONT PUSHING ACROSS WESTERN KANSAS EARLY FRIDAY MORNING WILL LIKELY DROP LOWS DOWN INTO THE 40S(F) ACROSS MUCH OF CENTRAL AND SOUTHWEST KANSAS TONIGHT. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 318 AM CDT THU SEP 11 2014 FRIDAY WILL BE COOL AND MOIST, WITH LIGHT RAIN LIKELY. FRIDAY WILL BE IN A POST FRONTAL REGIME, WITH COOL HIGH PRESSURE BUILDING IN FROM THE NORTHWEST. THE SURFACE FLOW WILL BE UPSLOPE WITH NORTHEAST TO EASTERLY WINDS AT 10 TO 20 MPH. CLOUDS WILL BE THICKEST IN THE MORNING, BUT STILL PREVALENT IN THE AFTERNOON. MAX TEMPS WILL GENERALLY BE IN THE 50S, BUT I ONLY EXPECT LIGHT RAIN WITH 0.05 TO 0.10 INCH ACCUMULATION. THE HIGH PRESSURE WILL BEGIN TO DOMINATE FRIDAY EVENING, LEADING TO CLEAR SKIES OVERNIGHT. THE COOL AIR WILL FILTRATE IN FROM THE NORTHWEST, AND FROST MAY BE POSSIBLE IN OUR EXTREME NORTHWESTERN COUNTIES OF TREGO, AND NORTHERN LANE AND SCOTT COUNTIES SATURDAY MORNING. AS THAT TIME FRAME APPROACHES, WE WILL NEED TO LOOK INTO A POSSIBLE WATCH OR REFINE THE AREA WHERE FROST MAY OCCUR. AFTER THE FALL-LIKE WEATHER ON FRIDAY, SATURDAY AND SUNDAY WILL SHOW A GRADUAL WARM UP, WITH HIGHS REACHING THE MID 60S TO LOWER 70S ON SATURDAY, AND BOUNDING UPWARD TO THE UPPER 70S TO LOWER 80S BY SUNDAY. A COLD FRONT WILL PLOW THROUGH TO THE SOUTHEAST ON MONDAY AFTERNOON, BRINGING A CHANCE FOR THUNDERSTORMS TO OUR SOUTHEAST-MOST ZONES, PRIMARILY IN PRATT AND BARBER COUNTIES. AN UPPER LEVEL WAVE WILL COME THROUGH IN THE FLOW MONDAY NIGHT, GIVING MOST OF THE CWA A 20 TO 30 PERCENT CHANCE FOR THUNDERSTORMS. A LEE SIDE TROUGH WILL BE IN WESTERN KANSAS TUESDAY AND WEDNESDAY, AND SLIGHT CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS WILL EXIST ACROSS MOST OF OUR FORECAST AREA, MAINLY THE EAST. WEDNESDAY WILL SEE A RETURN TO A WARM SOUTHWEST FLOW, AND HIGH TEMPERATURES WILL RESPOND LIKEWISE WITH VALUES IN THE LOWER 80S NORTH OF I-70 AND THE MIDDLE 80S SOUTHWEST A LINE FROM GARDEN CITY TO DODGE CITY TO MEDICINE LODGE. WINDS THROUGH THE EXTENDED DO NOT LOOK TOO STRONG, EXCEPT AHEAD OF THE FRONT ON MONDAY, AND THEN AGAIN BEHIND THE FRONT ON TUESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1200 AM CDT THU SEP 11 2014 LOW LEVEL STRATUS ACROSS MUCH OF NEBRASKA IS EXPECTED TO SHIFT SOUTH- SOUTHWEST INTO CENTRAL AND PORTIONS OF SOUTHWEST KANSAS EARLY THIS MORNING DROPPING CIGS WELL DOWN INTO THE MVFR CATEGORY IN THE VICINITY OF ALL TAF SITES. AS RELATIVE HUMIDITY INCREASES, BRIEF PERIODS OF IFR CIGS MAY BE POSSIBLE TOWARD SUNRISE WITH CIGS BEGINNING TO SLOWLY LIFT THROUGH THURSDAY AFTERNOON. LIGHT NORTHEASTERLY WINDS WILL PERSIST ACROSS CENTRAL AND SOUTHWEST KANSAS EARLY THIS MORNING AS SURFACE HIGH PRESSURE BEGINS TO SHIFT SOUTHEAST ACROSS THE NORTHERN PLAINS. WINDS MAY BECOME MORE EASTERLY DURING THE DAY THURSDAY AS THE SURFACE HIGH PUSHES FURTHER SOUTHEAST INTO NEBRASKA. && .PRELIMINARY POINT TEMPS/POPS... DDC 65 45 53 40 / 10 70 70 0 GCK 65 42 50 38 / 10 70 70 0 EHA 75 45 51 43 / 20 80 70 0 LBL 72 48 54 42 / 10 70 70 0 HYS 58 42 52 38 / 10 70 70 0 P28 65 50 58 43 / 10 70 70 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...JJOHNSON LONG TERM...BURKE AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
115 AM CDT THU SEP 11 2014 ...UPDATE TO SHORT TERM... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 112 AM CDT THU SEP 11 2014 SHORT TERM MODELS INDICATE AN UPPER LEVEL SHORTWAVE TROUGH DIGGING SOUTHEAST ACROSS THE NORTHERN ROCKIES TODAY AND PUSHING FURTHER SOUTHEAST INTO THE WESTERN HIGH PLAINS TONIGHT SETTING UP PRECIP CHANCES ACROSS NEBRASKA SOUTHWARD INTO PORTIONS OF WESTERN KANSAS. AS THE SHORTWAVE APPROACHES THIS EVENING, A SERIES OF H5 VORT MAXIMA WILL BEGIN TO EJECT EASTWARD OUT OF THE COLORADO ROCKIES INTO THE HIGH PLAINS OF EASTERN COLORADO AND WESTERN KANSAS. MEANWHILE, AN ATTENDANT COLD FRONT TO THE SHORTWAVE WILL BEGIN TO PUSH SOUTHWARD ACROSS WESTERN KANSAS LATE THIS EVENING INTO EARLY FRIDAY MORNING. OVERNIGHT, DYNAMIC SUPPORT ALOFT WILL BECOME MORE FAVORABLE AS THE RIGHT FRONT ENTRANCE REGION TO A +90KT JET EXITING THE APPROACHING TROUGH AXIS SHIFTS SOUTHWARD INTO WESTERN KANSAS. AS A RESULT, RAIN CHANCES WILL INCREASE ACROSS WESTERN KANSAS THIS EVENING, SPREADING SOUTH AND EAST ACROSS THE REGION OVERNIGHT. A FEW ISOLATED THUNDERSTORMS WILL BE POSSIBLE ACROSS EXTREME SOUTHWEST KANSAS THIS EVENING WHERE SOME INCREASED INSTABILITY AND MORE FAVORABLE VERTICAL SHEAR PROFILES WILL EXIST IN A SOUTHEASTERLY UPSLOPE FLOW. HOWEVER, NAM/GFS MODEL SOUNDINGS INDICATE LIMITED INSTABILITY WITH CAPE VALUES REMAINING WELL UNDER 1000 J/KG. THIS WILL RESTRICT THE POTENTIAL FOR SEVERE STORMS ACROSS SOUTHWEST KANSAS. TEMPERATURES WILL BE WELL BELOW NORMAL TODAY AS COOLER AIR FILTERS SOUTHWARD INTO WESTERN KANSAS AHEAD OF A BROAD SURFACE HIGH MOVING SOUTHEASTWARD OUT OF THE NORTHERN ROCKIES INTO THE HIGH PLAINS OF EASTERN WYOMING AND WESTERN NEBRASKA. THE NAM AND GFS SHOW H85 TEMPERATURES FALLING BELOW 10C ACROSS CENTRAL KANSAS NEAR THE I-70 CORRIDOR BY THIS AFTERNOON WITH THE MID TO UPPER TEENS(C) ACROSS EXTREME SOUTHWEST KANSAS WITHIN A SOUTHEAST UPSLOPE FLOW. ADDITIONALLY, HIGH TEMPERATURES MAY BE HINDERED TODAY DEPENDING ON HOW FAR SOUTH LOW LEVEL STRATUS MOVING OUT OF NEBRASKA THIS MORNING PUSHES INTO SOUTHWEST KANSAS, NOT TO MENTION HOW LONG IT MAY LAST. THE HRRR SUGGESTS THE STRATUS DECK PERSISTING THROUGH AT LEAST MID DAY, PARTICULARLY ACROSS CENTRAL KANSAS IN THE VICINITY OF THE I-70 CORRIDOR. BECAUSE OF THIS, HIGHS MAY STRUGGLE TO REACH THE 60S(F) IN CENTRAL KANSAS WITH THE LOWER TO MID 70S(F) POSSIBLE CLOSER TO THE OKLAHOMA BORDER, ESPECIALLY IN EXTREME SOUTHWEST KANSAS. A SECONDARY PUSH OF COLDER AIR BEHIND YET ANOTHER COLD FRONT PUSHING ACROSS WESTERN KANSAS EARLY FRIDAY MORNING WILL LIKELY DROP LOWS DOWN INTO THE 40S(F) ACROSS MUCH OF CENTRAL AND SOUTHWEST KANSAS TONIGHT. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 343 PM CDT WED SEP 10 2014 PRECIPITATION EPISODE THURSDAY NIGHT INTO THE FIRST HALF OF FRIDAY APPEARS TO BE ON TRACK. THERE REALLY WAS NOT A MAJOR CHANGE IN THE OVERALL THINKING REGARDING TIMING OF THE FRONT, PRECIPITATION, ETC...BUT THERE WERE A COUPLE OF ADJUSTMENTS. FIRST, IT APPEARS THAT MUCH OF THE PRECIPITATION INITIALLY ACROSS FAR WEST-CENTRAL AND SOUTHWEST KANSAS WILL BE CONVECTIVE IN NATURE. INTENSE CYCLOGENESIS DURING THE LATE DAY WILL ALLOW SURFACE MOISTURE TO DRAW NORTHWEST INTO FAR SOUTHEASTERN COLORADO/ADJACENT FAR SOUTHWEST KANSAS. THE NAM12 SHOWS A MESOSCALE AREA OF SURFACE-BASED CAPE AROUND 1000 J/KG, HOWEVER ANY SURFACE BASED STORMS SHOULD QUICKLY BECOME ELEVATED ABOVE A SURGING COLD AIRMASS FROM THE NORTH. EVENTUALLY, THE NATURE OF PRECIPITATION (ESPECIALLY BY 06Z) WILL BECOME STRATIFORM, SO IN THE GRIDS WE WILL CONTINUE TO CARRY "RAIN" AS THE PRECIPITATION (INSTEAD OF SHOWERS/THUNDERSTORMS). AS FAR AS FRIDAY GOES, THE FIRST HALF OF THE DAY WILL BE COMPOSED OF NORTH WINDS, LOW STRATUS, RAIN, AND TEMPERATURES IN THE 40S FOR MUCH OF THE SOUTHWEST KANSAS REGION, WHICH IS A STARK CHANGE TO SOME OF THE SUMMER WARMTH WE HAVE BEEN SEEING. FRIDAY HIGHS WILL OCCUR AT MIDNIGHT WITH TEMPERATURES FROM THE MID-UPPER 50S TO LOWER 60S. BY MID-MORNING, MOST EVERYONE WILL BE IN THE MID TO UPPER 40S...WITH STEADY TEMPERATURES THROUGH EARLY AFTERNOON. EVENTUALLY, CLOUDS WILL BREAK UP WITH SOME DIRECT INSOLATION BEING REALIZED, HELPING OFFSET THE COLD ADVECTION AS TEMPERATURES WARM INTO THE 50 TO 53F RANGE. SATURDAY MORNING WILL BE RATHER CHILLY WITH NEAR-RECORD LOW TEMPERATURES FOR MOST LOCATIONS. WE WILL BE GOING FOR LOWS OF 36F DOWN TO A SCOTT CITY TO WAKEENEY LINE WITH UPPER 30S AS FAR SOUTH AS THE ARKANSAS RIVER. THE ECMWF IS THE MOST AGGRESSIVE MODEL SHOWING THE CENTER OF A NEAR 1030MB HIGH FROM SOUTHWEST KANSAS INTO SOUTHWEST IOWA AND NEARLY CALM WINDS. IT LOOKS LIKE AN IDEAL RADIATIONAL COOLING NIGHT, PER THE ECMWF, AND IT IS CERTAINLY CONCEIVABLE WE SEE MORE AREAS OF THE WEST- CENTRAL/SOUTHWEST KANSAS REGION 36F OR EVEN COOLER YIELDING SOME FROST. WE WILL BEGIN TO WARM BACK UP OVER THE WEEKEND AS THE HIGH DEPARTS AND THE LOW LEVEL AIRMASS MODIFIES. THE FORECAST IS DRY THROUGH LATE SUNDAY, HOWEVER SUNDAY EVENING/NIGHT SOME WARM ADVECTION IN THE 800- 900MB LAYER MAY SUPPORT SOME NOCTURNAL SHOWERS/THUNDERSTORMS AND WE WILL HAVE SOME 20 POPS IN CENTRAL/SOUTH CENTRAL KANSAS FOR THAT POSSIBILITY. ANOTHER FRONTAL PASSAGE IS ANTICIPATED MONDAY WITH COOLER AIR SETTLING BACK IN AS ANOTHER DECENT SHORTWAVE TROUGH MOVES EAST-SOUTHEAST ACROSS THE NORTHERN PLAINS INTO THE UPPER MIDWEST REGION. HIGHEST POPS (30 PERCENT) WILL BE MONDAY NIGHT WITHIN THE BAROCLINIC ZONE 800-700MB. IT IS STILL PRETTY FAR AWAY IN THE FORECAST, BUT TUESDAY HIGHS WILL LIKELY BE LOWERED IF SUCCESSIVE GLOBAL SPECTRAL MODEL RUNS CONTINUE TO SHOW A FAIRLY DECENT FRONTAL PASSAGE AS THE 12Z RUNS SHOWED TODAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1200 AM CDT THU SEP 11 2014 LOW LEVEL STRATUS ACROSS MUCH OF NEBRASKA IS EXPECTED TO SHIFT SOUTH- SOUTHWEST INTO CENTRAL AND PORTIONS OF SOUTHWEST KANSAS EARLY THIS MORNING DROPPING CIGS WELL DOWN INTO THE MVFR CATEGORY IN THE VICINITY OF ALL TAF SITES. AS RELATIVE HUMIDITY INCREASES, BRIEF PERIODS OF IFR CIGS MAY BE POSSIBLE TOWARD SUNRISE WITH CIGS BEGINNING TO SLOWLY LIFT THROUGH THURSDAY AFTERNOON. LIGHT NORTHEASTERLY WINDS WILL PERSIST ACROSS CENTRAL AND SOUTHWEST KANSAS EARLY THIS MORNING AS SURFACE HIGH PRESSURE BEGINS TO SHIFT SOUTHEAST ACROSS THE NORTHERN PLAINS. WINDS MAY BECOME MORE EASTERLY DURING THE DAY THURSDAY AS THE SURFACE HIGH PUSHES FURTHER SOUTHEAST INTO NEBRASKA. && .PRELIMINARY POINT TEMPS/POPS... DDC 67 45 53 40 / 10 70 70 0 GCK 67 42 50 38 / 10 70 70 0 EHA 75 45 51 43 / 20 80 70 0 LBL 72 48 54 42 / 10 70 70 0 HYS 60 42 52 38 / 10 70 70 0 P28 72 50 58 43 / 10 70 70 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...JJOHNSON LONG TERM...UMSCHEID AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS PADUCAH KY
837 PM CDT Fri Sep 12 2014 .UPDATE... Issued at 836 PM CDT FRI SEP 12 2014 Advancement of a sheared shortwave vorticity axis coincident with decent low level moisture in the 306-311K isentropic layer across the WFO PAH forecast area. Improved condensation pressure deficits and local pressure derivatives of up to 1 microbars/second are forecast to move across the Southeast Missouri Delta, the Purchase Area and Pennyrile areas of West Kentucky between 02z-10z per the NMM version of the 4km NAM-WRF, the 13km RAP, and 3km HRRR guidance. With this in mind, adjusted the gridded forecast to enhances some area with a mixture of measurable PoP/Weather (very light rain) and patchy/areas of trace precipitation (drizzle) overnight. There may be a miss for some areas, but attempted to use the high resolution guidance to focus on those areas from late evening to the early morning hours on Saturday for rain chances. To accommodate (non-diabatic) sensible weather changes with these enhanced precipitation areas, minor tweaks to temperature, dewpoint, and winds were also modified for the evening. Dry air advection with time at the lower levels should limit any measurable visibility restrictions due to the precipitation overnight. Given the short temporal (time) and spatial (space) impacts of the precipitation, these adjustments will show up more in the gridded forecast (available through the point and click forecast on the NWS Paducah web page) and tabular forecast versus the general text forecast for specific forecast locations overnight. && .SHORT TERM...(Tonight through Sunday night) Issued at 250 PM CDT FRI SEP 12 2014 The upper-level storm system is currently moving eastward through Minnesota, and the trough trails to the southwest into the central Plains. Some light showers are trying to move northeast out of central Arkansas and toward the four state region. The general consensus of the 12Z guidance is that the precipitation will dissipate before reaching our region. The lone exception appears to be the NAM which drags some light showers or drizzle northeast through the Pennyrile region of Kentucky in the late evening and early morning hours. Decided to keep a slight chance of showers in the far east in that time period, but kept the rest of the area dry tonight. There has been an increase in drizzly echoes to the south and southeast of KPAH in the last hour, so also added patchy drizzle over the southern half of the forecast area through 06Z. The models continue to indicate a rapid clearing trend late tonight and Saturday morning, as the upper system passes by and the surface high really begins to surge across the area. Some locations may test record min max temperatures Saturday. The record min max at KPAH today is going to be shattered, but Saturday will be with full sunshine. Gusty north winds will make it feel even cooler Saturday afternoon. Surface high pressure will slowly settle over the region, and winds over much of the area may drop to near calm. This will likely lead to good radiational cooling, and with dewpoints well into the 40s throughout the area, some record lows may be tested Sunday morning. Some moderation is expected in both temperatures and dewpoints Sunday, but guidance may be a bit aggressive with those trends. .LONG TERM...(Monday through Friday) Issued at 250 PM CDT FRI SEP 12 2014 For the upcoming work week, the weather appears to be fairly quiet. The only real challenge will be Monday-Tuesday when decisions have to be made on the likelihood of rain with an incoming frontal boundary. Lower level moisture will be lacking for much of Monday, with the bulk of it to our northwest. Therefore, believe that much of the area will be dry. As we head into Monday night into Tuesday, low level moisture will be increasing from the north and settle into the area. The 00Z ECMWF stays the course of its past runs and shows the moisture blasting on through here and exiting by Tuesday morning, not bringing us much of anything in the way of precip. The GFS a slower solution and indicates better chances for precip after midnight Monday night in the northwestern half. This is also supported by a few members of the GFS precip ensembles. However, the moisture is slow to move through, so it is possible to see a few lingering showers into Tuesday, but will leave mainly dry for now. After watching the behavior of the last several runs of the GFS, it has definitely been favoring this scenario, unlike the faster Euro. Nevertheless, by Wednesday, high pressure will build in and northwest flow aloft will take over...with no big signals of any other systems to deal with for the rest of the week. && .AVIATION... Issued at 637 PM CDT FRI SEP 12 2014 With moisture still trapped below the inversion, IFR/MVFR cigs will continue through 14-16Z, then VFR. Northerly winds AOB 10 knots will continue through 14Z, then veer around to the north northeast around 15Z at 10 knots with gusts up to 18-20 knots at KCGI/KPAH. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ UPDATE...Smith SHORT TERM...DRS LONG TERM...CW AVIATION...JP
AREA FORECAST DISCUSSION
NWS JACKSON KY
354 PM EDT THU SEP 11 2014 .UPDATE... ISSUED AT 142 PM EDT THU SEP 11 2014 CONSIDERING APPARENT FRONTAL POSITION AND PRECIP TRENDS...HAVE LOWERED POPS FOR THIS AFTERNOON NORTH OF KJKL. ALSO...OBSERVED TEMPS HAVE SURPASSED PREVIOUS FORECAST HIGHS IN OUR SOUTHERN COUNTIES. WITH DEVELOPMENT OF PRECIP...IT SHOULD NOT GET TOO MUCH WARMER THERE...BUT FORECAST MAX TEMPS DID NEED TO BE RAISED. UPDATE ISSUED AT 1014 AM EDT THU SEP 11 2014 MADE ADJUSTMENTS TO TIMING OF SOUTHWARD PROGRESSION OF HIGHER POPS TODAY...BUT WITH LITTLE IMPACT ON THE GENERAL 12 HOUR OUTLOOK. UPDATE ISSUED AT 645 AM EDT THU SEP 11 2014 MADE A FEW ADJUSTMENTS TO THE FORECAST GRIDS FOR EARLY THIS MORNING BASED ON THE CURRENT RADAR TRENDS. DECIDED TO SLIGHTLY SPEED UP THE EASTWARD PROGRESSION OF SHOWERS AND STORMS THIS MORNING PER LATEST RADAR. BASED ON UPSTREAM SHOWER AND STORM FORMATION...AND THE STILL SLOW EASTWARD MOVEMENT OF THE COLD FRONT...IT STILL APPEARS THAT WIDESPREAD RAINFALL WILL OCCUR ACROSS EASTERN KENTUCKY THROUGH THIS AFTERNOON. LOCALLY HEAVY RAINFALL...AND PERHAPS SOME ISOLATED INSTANCES OF FLOODING...WILL STILL BE POSSIBLE AS NUMEROUS STORMS WILL LIKELY MOVE ACROSS THE SAME LOCATIONS THROUGHOUT THE DAY. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 323 AM EDT THU SEP 11 2014 THE MODELS WERE IN GOOD AGREEMENT WITH THE LARGE SCALE AND LOCAL WEATHER PATTERN FOR THE FIRST 36 HOURS OF THE FORECAST. THE NAM12...SREF...AND HRRR MODELS HAVE ALL HANDLED THE TIMING AND EVOLUTION OF A LINE OF SHOWERS AND STORMS THAT IS CURRENTLY MOVING ACROSS CENTRAL KENTUCKY AND SOUTHERN OHIO. THE NAM12 AND SREF SEEM TO DO A BETTER JOB OF HANDLING THE EVOLUTION OF THIS LINE OF SHOWERS AND STORMS AFTER SUNRISE TODAY THAN THE HRRR...SO THOSE TWO MODELS WERE USED TO CREATE THE NEW FORECAST. THE MODELS SUGGEST A STRONG COLD FRONT WILL MOVE ACROSS CENTRAL AND EASTERN KENTUCKY TODAY...WITH THE BOUNDARY EXITING THE AREA LATE THIS AFTERNOON. WIDESPREAD SHOWERS AND STORMS ARE EXPECTED TO CONTINUE FIRING ALONG AND JUST AHEAD OF THIS FRONT...WITH THE PEAK IN ACTIVITY OCCURRING BETWEEN ROUGHLY NOON AND 5 PM. THE LATEST FORECAST SOUNDINGS CONTINUE TO SUPPORT THE POTENTIAL FOR LOCALLY HEAVY RAINFALL...WITH PRECIPITABLE WATER VALUES OF AROUND 2 INCHES PERSISTING THROUGH THE OVERNIGHT HOURS. SOME OF THE STRONGER THUNDERSTORMS COULD ALSO PRODUCE GUSTY WINDS...BUT LOCALLY HEAVY RAINFALL WILL BE THE PRIMARY THREAT. THE RAIN CHANCES WILL NOT END ONCE THE FRONT HAS PASSED BY US...HOWEVER. THE BOUNDARY IS EXPECTED TO STALL ACROSS THE TENNESSEE VALLEY ON FRIDAY. WAVES OF LOW PRESSURE ARE THEN PROGGED TO MIGRATE FROM WEST TO EAST ALONG THE FRONT. THESE DISTURBANCES WILL BRING ENOUGH LIFT AND MOISTURE TO LOCATIONS SOUTH OF THE MOUNTAIN PARKWAY TO PERHAPS FIRE OFF ISOLATED TO SCATTERED RAIN SHOWERS LATE TONIGHT THROUGH THE END OF THE DAY ON FRIDAY. ONCE THE FRONT MOVES THROUGH EARLY TONIGHT...AN UNSEASONABLY COOL CANADIAN AIR MASS WILL SETTLE OVER THE AREA. THIS AIR MASS WILL BRING FALL LIKE TEMPERATURES TO EASTERN KENTUCKY TONIGHT AND FRIDAY. THE COOL WEATHER WILL FIRST BE EXPERIENCED LATE TONIGHT...AS WINDS SHIFT TO THE NORTH AND THE COOL AIR FULLY INVADES THE REGION. TONIGHTS LOWS ARE EXPECTED TO BOTTOM OUT IN THE LOW TO MID 60S FOR MOST LOCATIONS. FOLKS ALONG AND NORTH OF THE I-64 CORRIDOR MAY SEE THE MERCURY DIP INTO THE UPPER 50S BY FRIDAY MORNING. HIGH TEMPERATURES ON FRIDAY WILL LIKELY ONLY CLIMB INTO THE LOW TO MID 70S ACROSS THE AREA. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 354 PM EDT THU SEP 11 2014 MID TERM MODELS ARE STILL IN GOOD AGREEMENT FOR THE UPPER LEVEL LONG WAVE PATTERN. A CLOSED LOW WILL BE PASSING ALONG THE UPPER GREAT LAKES AT THE START OF THE FORECAST PERIOD...QUICKLY MOVING EASTWARD AND LOSING STRENGTH. MEANWHILE...AN UPPER LEVEL RIDGE ACROSS THE SOUTHERN CONUS WILL KEEP A GOOD TRANSITION ZONE OVER THE OHIO RIVER VALLEY WITH STRONG WRLY FLOW. THIS SHORTWAVE/CLOSED LOW WILL CAUSE A DISTURBANCE AT THE SURFACE...WITH A STRONG AREA OF QVECTOR CONVERGENCE EXPECTED TO MOVE ACROSS THE UPPER GREAT LAKES REGION AS WELL BY THE START OF THE FORECAST PERIOD. KY WILL FIND ITSELF ON THE SOUTHERN FRINGES OF THIS DISTURBANCE...EXITING AS WE HEAD INTO 12Z SATURDAY. AS IT QUICKLY PUSHES OFF TO THE EAST DURING THE DAY...ANY PRECIP CHANCES WILL CEASE ACROSS FAR SE KY BY LATE SAT AFTERNOON. MODELS ARE CONTINUING TO SUPPORT A FASTER EXIT OF PRECIPITATION COMPARED TO THAT OF PREVIOUS RUNS FOR DURING THE DAY SATURDAY. CUT BACK POPS SLIGHTLY...WITH ALL RAIN EXITING KY BY 0Z SUNDAY. THE BOUNDARY WILL BECOME STALLED OUT ONCE MORE TO OUR SOUTH...NEAR THE ATLANTIC COAST. HOWEVER...WITH THE INFLUX OF MOISTURE FROM THE ATLANTIC...DAYTIME INSTABILITY WILL HELP PRECIP CHANCES SPREAD FARTHER NORTH...POSSIBLY MAKING IT TO THE FAR SE BORDER OF KY DURING THE DAY SUNDAY. PREVIOUS FORECAST LEFT MENTION OF PRECIP OUT ALONG THE BORDER. HOWEVER...LATEST MODEL RUNS ARE ALL IN VERY GOOD AGREEMENT THAT POPS MOVE CLOSE ENOUGH TO OUR BORDER THAT CONFIDENCE ERRED ON THE SIDE AT LEAST INCLUDING SOME SLIGHT CHANCE POPS FOR THE HIGH TERRAIN ALONG THE TN/VA BORDER. THE SAME APPLIES FOR DURING THE DAY MONDAY....ALTHOUGH MODELS ARE GOOD AGREEMENT OF THE PRECIP SPREADING FARTHER INTO THE CWA DURING THE DAY AS THE BOUNDARY SHIFTS SLIGHTLY NORTHWARD. MEANWHILE MONDAY...ANOTHER SHORTWAVE WILL DEVELOP IN THE LONGWAVE PATTERN...DROPPING HEIGHTS SLIGHTLY ACROSS EASTERN KY AND BRINGING YET ANOTHER QUICK MOVING BUT WEAK SURFACE COLD FRONT THAT WILL SWEEP THROUGH KY LATE MONDAY NIGHT. ONCE AGAIN...ERN KY WILL FIND ITSELF ON THE SOUTHERN FRINGES OF THIS DISTURBANCE...BUT THE BOUNDARY SHOULD INTERACT ENOUGH WITH THE ONGOING PRECIP IN THE SE TO KEEP POPS GOING THROUGHOUT MOST OF THE NIGHT MONDAY NIGHT AS WELL. STRONG SUBSIDENCE WILL MOVE IN BEHIND THE FRONTAL BOUNDARY...WITH POPS QUICKLY TAPERING OFF BY EARLY TUESDAY. WIDESPREAD CLOUD COVER WILL ALSO ACCOMPANY THIS SYSTEM...SLOWLY CLEARING THROUGHOUT THE DAY TUESDAY. HIGH PRESSURE...ONCE IN CONTROL...SHOULD STAY FOR THE REMAINDER OF THE FORECAST PERIOD...WITH EASTERN KY FINALLY EXPECTED TO HAVE A BREAK FROM THE PRECIP FROM TUESDAY THROUGH THURSDAY. OVERALL...STRONG ZONAL FLOW ACROSS KY WILL KEEP TEMPERATURES MODERATED IN THE MID 70S THROUGH MUCH OF THE EXTENDED FORECAST. OVERNIGHT LOWS WILL BE CLOUD DEPENDENT. FOR THOSE NIGHTS WHEN CLEARING IS EXPECTED...LOWS COULD DROP DOWN INTO THE CHILLY LOW TO MID 50S. AND WHEN THERE IS CLOUD COVER INVOLVED...AS IS THE CASE IN THE SE FOR MUCH OF THE EXTENDED...UPPER 50S AND LOW 60S WILL BE RANGE TO LOOK FOR. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1255 PM EDT THU SEP 11 2014 EARLY AFTERNOON CONDITIONS RANGED FROM VLIFR IN MANY LOCATIONS NEAR AND NORTH OF I-64...TO VFR IN MOST PLACES NEAR THE TN AND VA BORDERS. SHOWERS WERE OCCURRING AND BECOMING MORE NUMEROUS ALONG AND SOUTHEAST OF A LINE FROM SOMERSET TO PAINTSVILLE. DURING THE AFTERNOON...THE TREND OF INCREASING PRECIP SOUTH AND EAST OF KJKL SHOULD CONTINUE...WITH A SLIGHT CHANCE FOR THUNDERSTORMS TOO. MVFR AND IFR WILL SPREAD/DEVELOP SOUTHEASTWARD TO THE STATE LINE BY ABOUT 00Z. MEANWHILE LOCATIONS NEAR/NORTH OF I-64 SHOULD SEE IMPROVEMENT...WITH CEILINGS EVENTUALLY BREAKING UP TONIGHT AND FRIDAY. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HAL SHORT TERM...AR LONG TERM...JMW AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
142 PM EDT THU SEP 11 2014 .UPDATE... ISSUED AT 142 PM EDT THU SEP 11 2014 CONSIDERING APPARENT FRONTAL POSITION AND PRECIP TRENDS...HAVE LOWERED POPS FOR THIS AFTERNOON NORTH OF KJKL. ALSO...OBSERVED TEMPS HAVE SURPASSED PREVIOUS FORECAST HIGHS IN OUR SOUTHERN COUNTIES. WITH DEVELOPMENT OF PRECIP...IT SHOULD NOT GET TOO MUCH WARMER THERE...BUT FORECAST MAX TEMPS DID NEED TO BE RAISED. UPDATE ISSUED AT 1014 AM EDT THU SEP 11 2014 MADE ADJUSTMENTS TO TIMING OF SOUTHWARD PROGRESSION OF HIGHER POPS TODAY...BUT WITH LITTLE IMPACT ON THE GENERAL 12 HOUR OUTLOOK. UPDATE ISSUED AT 645 AM EDT THU SEP 11 2014 MADE A FEW ADJUSTMENTS TO THE FORECAST GRIDS FOR EARLY THIS MORNING BASED ON THE CURRENT RADAR TRENDS. DECIDED TO SLIGHTLY SPEED UP THE EASTWARD PROGRESSION OF SHOWERS AND STORMS THIS MORNING PER LATEST RADAR. BASED ON UPSTREAM SHOWER AND STORM FORMATION...AND THE STILL SLOW EASTWARD MOVEMENT OF THE COLD FRONT...IT STILL APPEARS THAT WIDESPREAD RAINFALL WILL OCCUR ACROSS EASTERN KENTUCKY THROUGH THIS AFTERNOON. LOCALLY HEAVY RAINFALL...AND PERHAPS SOME ISOLATED INSTANCES OF FLOODING...WILL STILL BE POSSIBLE AS NUMEROUS STORMS WILL LIKELY MOVE ACROSS THE SAME LOCATIONS THROUGHOUT THE DAY. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 323 AM EDT THU SEP 11 2014 THE MODELS WERE IN GOOD AGREEMENT WITH THE LARGE SCALE AND LOCAL WEATHER PATTERN FOR THE FIRST 36 HOURS OF THE FORECAST. THE NAM12...SREF...AND HRRR MODELS HAVE ALL HANDLED THE TIMING AND EVOLUTION OF A LINE OF SHOWERS AND STORMS THAT IS CURRENTLY MOVING ACROSS CENTRAL KENTUCKY AND SOUTHERN OHIO. THE NAM12 AND SREF SEEM TO DO A BETTER JOB OF HANDLING THE EVOLUTION OF THIS LINE OF SHOWERS AND STORMS AFTER SUNRISE TODAY THAN THE HRRR...SO THOSE TWO MODELS WERE USED TO CREATE THE NEW FORECAST. THE MODELS SUGGEST A STRONG COLD FRONT WILL MOVE ACROSS CENTRAL AND EASTERN KENTUCKY TODAY...WITH THE BOUNDARY EXITING THE AREA LATE THIS AFTERNOON. WIDESPREAD SHOWERS AND STORMS ARE EXPECTED TO CONTINUE FIRING ALONG AND JUST AHEAD OF THIS FRONT...WITH THE PEAK IN ACTIVITY OCCURRING BETWEEN ROUGHLY NOON AND 5 PM. THE LATEST FORECAST SOUNDINGS CONTINUE TO SUPPORT THE POTENTIAL FOR LOCALLY HEAVY RAINFALL...WITH PRECIPITABLE WATER VALUES OF AROUND 2 INCHES PERSISTING THROUGH THE OVERNIGHT HOURS. SOME OF THE STRONGER THUNDERSTORMS COULD ALSO PRODUCE GUSTY WINDS...BUT LOCALLY HEAVY RAINFALL WILL BE THE PRIMARY THREAT. THE RAIN CHANCES WILL NOT END ONCE THE FRONT HAS PASSED BY US...HOWEVER. THE BOUNDARY IS EXPECTED TO STALL ACROSS THE TENNESSEE VALLEY ON FRIDAY. WAVES OF LOW PRESSURE ARE THEN PROGGED TO MIGRATE FROM WEST TO EAST ALONG THE FRONT. THESE DISTURBANCES WILL BRING ENOUGH LIFT AND MOISTURE TO LOCATIONS SOUTH OF THE MOUNTAIN PARKWAY TO PERHAPS FIRE OFF ISOLATED TO SCATTERED RAIN SHOWERS LATE TONIGHT THROUGH THE END OF THE DAY ON FRIDAY. ONCE THE FRONT MOVES THROUGH EARLY TONIGHT...AN UNSEASONABLY COOL CANADIAN AIR MASS WILL SETTLE OVER THE AREA. THIS AIR MASS WILL BRING FALL LIKE TEMPERATURES TO EASTERN KENTUCKY TONIGHT AND FRIDAY. THE COOL WEATHER WILL FIRST BE EXPERIENCED LATE TONIGHT...AS WINDS SHIFT TO THE NORTH AND THE COOL AIR FULLY INVADES THE REGION. TONIGHTS LOWS ARE EXPECTED TO BOTTOM OUT IN THE LOW TO MID 60S FOR MOST LOCATIONS. FOLKS ALONG AND NORTH OF THE I-64 CORRIDOR MAY SEE THE MERCURY DIP INTO THE UPPER 50S BY FRIDAY MORNING. HIGH TEMPERATURES ON FRIDAY WILL LIKELY ONLY CLIMB INTO THE LOW TO MID 70S ACROSS THE AREA. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 431 AM EDT THU SEP 11 2014 THE MODELS ARE IN GOOD AGREEMENT WITH THE LONG WAVE PATTERN THROUGH THE PERIOD. PROGRESSIVE AND AMPLIFIED FLOW WILL CONTROL ACROSS THE NORTHERN HALF OF THE CONUS AS SEVERAL PASSING SHORT WAVES HELP TO REINFORCE TROUGHING ACROSS THE REGION. UPPER LEVEL RIDGING HANGING ON ACROSS THE SOUTHERN CONUS WILL GRADUALLY DAMPEN AND GET SUPPRESSED FURTHER SOUTH INTO EARLY NEXT WEEK...BEFORE CONSOLIDATING MORE ACROSS THE DESERT SOUTHWEST BY THE MIDDLE OF NEXT WEEK. FOR EASTERN KENTUCKY...THE FIRST MAIN SHORT WAVE WILL MOVE THROUGH FRIDAY NIGHT INTO SATURDAY...BRINGING A CHANCE OF SHOWERS. GENERALLY DRY WEATHER CAN BE EXPECTED FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT...AS HIGH PRESSURE TEMPORARILY BUILDS IN AT THE SURFACE. A DEEPER TROUGH AXIS...WITH SOME SURFACE DEVELOPMENT NOTED BY THE MODELS...WILL THEN AFFECT THE AREA FROM MONDAY THROUGH TUESDAY. THIS SYSTEM WILL BRING SOME RENEWED CHANCES OF SHOWERS...ALTHOUGH THERE WILL NOT BE AS MUCH LOW LEVEL MOISTURE TO WORK WITH...SO STUCK FAIRLY CLOSE TO THE BLENDED GUIDANCE ON THE POPS. DRY WEATHER WILL ENSUE ONCE AGAIN THEREAFTER...AS SURFACE HIGH PRESSURE BUILDS IN ACROSS THE OHIO VALLEY. TEMPERATURES WILL AVERAGE BELOW NORMAL THROUGH THE PERIOD...WITH HIGHS MAINLY IN THE LOW TO MID 70S AND LOWS IN THE 50S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1255 PM EDT THU SEP 11 2014 EARLY AFTERNOON CONDITIONS RANGED FROM VLIFR IN MANY LOCATIONS NEAR AND NORTH OF I-64...TO VFR IN MOST PLACES NEAR THE TN AND VA BORDERS. SHOWERS WERE OCCURRING AND BECOMING MORE NUMEROUS ALONG AND SOUTHEAST OF A LINE FROM SOMERSET TO PAINTSVILLE. DURING THE AFTERNOON...THE TREND OF INCREASING PRECIP SOUTH AND EAST OF KJKL SHOULD CONTINUE...WITH A SLIGHT CHANCE FOR THUNDERSTORMS TOO. MVFR AND IFR WILL SPREAD/DEVELOP SOUTHEASTWARD TO THE STATE LINE BY ABOUT 00Z. MEANWHILE LOCATIONS NEAR/NORTH OF I-64 SHOULD SEE IMPROVEMENT...WITH CEILINGS EVENTUALLY BREAKING UP TONIGHT AND FRIDAY. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HAL SHORT TERM...AR LONG TERM...GEOGERIAN AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
1255 PM EDT THU SEP 11 2014 .UPDATE... ISSUED AT 1014 AM EDT THU SEP 11 2014 MADE ADJUSTMENTS TO TIMING OF SOUTHWARD PROGRESSION OF HIGHER POPS TODAY...BUT WITH LITTLE IMPACT ON THE GENERAL 12 HOUR OUTLOOK. UPDATE ISSUED AT 645 AM EDT THU SEP 11 2014 MADE A FEW ADJUSTMENTS TO THE FORECAST GRIDS FOR EARLY THIS MORNING BASED ON THE CURRENT RADAR TRENDS. DECIDED TO SLIGHTLY SPEED UP THE EASTWARD PROGRESSION OF SHOWERS AND STORMS THIS MORNING PER LATEST RADAR. BASED ON UPSTREAM SHOWER AND STORM FORMATION...AND THE STILL SLOW EASTWARD MOVEMENT OF THE COLD FRONT...IT STILL APPEARS THAT WIDESPREAD RAINFALL WILL OCCUR ACROSS EASTERN KENTUCKY THROUGH THIS AFTERNOON. LOCALLY HEAVY RAINFALL...AND PERHAPS SOME ISOLATED INSTANCES OF FLOODING...WILL STILL BE POSSIBLE AS NUMEROUS STORMS WILL LIKELY MOVE ACROSS THE SAME LOCATIONS THROUGHOUT THE DAY. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 323 AM EDT THU SEP 11 2014 THE MODELS WERE IN GOOD AGREEMENT WITH THE LARGE SCALE AND LOCAL WEATHER PATTERN FOR THE FIRST 36 HOURS OF THE FORECAST. THE NAM12...SREF...AND HRRR MODELS HAVE ALL HANDLED THE TIMING AND EVOLUTION OF A LINE OF SHOWERS AND STORMS THAT IS CURRENTLY MOVING ACROSS CENTRAL KENTUCKY AND SOUTHERN OHIO. THE NAM12 AND SREF SEEM TO DO A BETTER JOB OF HANDLING THE EVOLUTION OF THIS LINE OF SHOWERS AND STORMS AFTER SUNRISE TODAY THAN THE HRRR...SO THOSE TWO MODELS WERE USED TO CREATE THE NEW FORECAST. THE MODELS SUGGEST A STRONG COLD FRONT WILL MOVE ACROSS CENTRAL AND EASTERN KENTUCKY TODAY...WITH THE BOUNDARY EXITING THE AREA LATE THIS AFTERNOON. WIDESPREAD SHOWERS AND STORMS ARE EXPECTED TO CONTINUE FIRING ALONG AND JUST AHEAD OF THIS FRONT...WITH THE PEAK IN ACTIVITY OCCURRING BETWEEN ROUGHLY NOON AND 5 PM. THE LATEST FORECAST SOUNDINGS CONTINUE TO SUPPORT THE POTENTIAL FOR LOCALLY HEAVY RAINFALL...WITH PRECIPITABLE WATER VALUES OF AROUND 2 INCHES PERSISTING THROUGH THE OVERNIGHT HOURS. SOME OF THE STRONGER THUNDERSTORMS COULD ALSO PRODUCE GUSTY WINDS...BUT LOCALLY HEAVY RAINFALL WILL BE THE PRIMARY THREAT. THE RAIN CHANCES WILL NOT END ONCE THE FRONT HAS PASSED BY US...HOWEVER. THE BOUNDARY IS EXPECTED TO STALL ACROSS THE TENNESSEE VALLEY ON FRIDAY. WAVES OF LOW PRESSURE ARE THEN PROGGED TO MIGRATE FROM WEST TO EAST ALONG THE FRONT. THESE DISTURBANCES WILL BRING ENOUGH LIFT AND MOISTURE TO LOCATIONS SOUTH OF THE MOUNTAIN PARKWAY TO PERHAPS FIRE OFF ISOLATED TO SCATTERED RAIN SHOWERS LATE TONIGHT THROUGH THE END OF THE DAY ON FRIDAY. ONCE THE FRONT MOVES THROUGH EARLY TONIGHT...AN UNSEASONABLY COOL CANADIAN AIR MASS WILL SETTLE OVER THE AREA. THIS AIR MASS WILL BRING FALL LIKE TEMPERATURES TO EASTERN KENTUCKY TONIGHT AND FRIDAY. THE COOL WEATHER WILL FIRST BE EXPERIENCED LATE TONIGHT...AS WINDS SHIFT TO THE NORTH AND THE COOL AIR FULLY INVADES THE REGION. TONIGHTS LOWS ARE EXPECTED TO BOTTOM OUT IN THE LOW TO MID 60S FOR MOST LOCATIONS. FOLKS ALONG AND NORTH OF THE I-64 CORRIDOR MAY SEE THE MERCURY DIP INTO THE UPPER 50S BY FRIDAY MORNING. HIGH TEMPERATURES ON FRIDAY WILL LIKELY ONLY CLIMB INTO THE LOW TO MID 70S ACROSS THE AREA. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 431 AM EDT THU SEP 11 2014 THE MODELS ARE IN GOOD AGREEMENT WITH THE LONG WAVE PATTERN THROUGH THE PERIOD. PROGRESSIVE AND AMPLIFIED FLOW WILL CONTROL ACROSS THE NORTHERN HALF OF THE CONUS AS SEVERAL PASSING SHORT WAVES HELP TO REINFORCE TROUGHING ACROSS THE REGION. UPPER LEVEL RIDGING HANGING ON ACROSS THE SOUTHERN CONUS WILL GRADUALLY DAMPEN AND GET SUPPRESSED FURTHER SOUTH INTO EARLY NEXT WEEK...BEFORE CONSOLIDATING MORE ACROSS THE DESERT SOUTHWEST BY THE MIDDLE OF NEXT WEEK. FOR EASTERN KENTUCKY...THE FIRST MAIN SHORT WAVE WILL MOVE THROUGH FRIDAY NIGHT INTO SATURDAY...BRINGING A CHANCE OF SHOWERS. GENERALLY DRY WEATHER CAN BE EXPECTED FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT...AS HIGH PRESSURE TEMPORARILY BUILDS IN AT THE SURFACE. A DEEPER TROUGH AXIS...WITH SOME SURFACE DEVELOPMENT NOTED BY THE MODELS...WILL THEN AFFECT THE AREA FROM MONDAY THROUGH TUESDAY. THIS SYSTEM WILL BRING SOME RENEWED CHANCES OF SHOWERS...ALTHOUGH THERE WILL NOT BE AS MUCH LOW LEVEL MOISTURE TO WORK WITH...SO STUCK FAIRLY CLOSE TO THE BLENDED GUIDANCE ON THE POPS. DRY WEATHER WILL ENSUE ONCE AGAIN THEREAFTER...AS SURFACE HIGH PRESSURE BUILDS IN ACROSS THE OHIO VALLEY. TEMPERATURES WILL AVERAGE BELOW NORMAL THROUGH THE PERIOD...WITH HIGHS MAINLY IN THE LOW TO MID 70S AND LOWS IN THE 50S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1255 PM EDT THU SEP 11 2014 EARLY AFTERNOON CONDITIONS RANGED FROM VLIFR IN MANY LOCATIONS NEAR AND NORTH OF I-64...TO VFR IN MOST PLACES NEAR THE TN AND VA BORDERS. SHOWERS WERE OCCURRING AND BECOMING MORE NUMEROUS ALONG AND SOUTHEAST OF A LINE FROM SOMERSET TO PAINTSVILLE. DURING THE AFTERNOON...THE TREND OF INCREASING PRECIP SOUTH AND EAST OF KJKL SHOULD CONTINUE...WITH A SLIGHT CHANCE FOR THUNDERSTORMS TOO. MVFR AND IFR WILL SPREAD/DEVELOP SOUTHEASTWARD TO THE STATE LINE BY ABOUT 00Z. MEANWHILE LOCATIONS NEAR/NORTH OF I-64 SHOULD SEE IMPROVEMENT...WITH CEILINGS EVENTUALLY BREAKING UP TONIGHT AND FRIDAY. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HAL SHORT TERM...AR LONG TERM...GEOGERIAN AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
1014 AM EDT THU SEP 11 2014 .UPDATE... ISSUED AT 1014 AM EDT THU SEP 11 2014 MADE ADJUSTMENTS TO TIMING OF SOUTHWARD PROGRESSION OF HIGHER POPS TODAY...BUT WITH LITTLE IMPACT ON THE GENERAL 12 HOUR OUTLOOK. UPDATE ISSUED AT 645 AM EDT THU SEP 11 2014 MADE A FEW ADJUSTMENTS TO THE FORECAST GRIDS FOR EARLY THIS MORNING BASED ON THE CURRENT RADAR TRENDS. DECIDED TO SLIGHTLY SPEED UP THE EASTWARD PROGRESSION OF SHOWERS AND STORMS THIS MORNING PER LATEST RADAR. BASED ON UPSTREAM SHOWER AND STORM FORMATION...AND THE STILL SLOW EASTWARD MOVEMENT OF THE COLD FRONT...IT STILL APPEARS THAT WIDESPREAD RAINFALL WILL OCCUR ACROSS EASTERN KENTUCKY THROUGH THIS AFTERNOON. LOCALLY HEAVY RAINFALL...AND PERHAPS SOME ISOLATED INSTANCES OF FLOODING...WILL STILL BE POSSIBLE AS NUMEROUS STORMS WILL LIKELY MOVE ACROSS THE SAME LOCATIONS THROUGHOUT THE DAY. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 323 AM EDT THU SEP 11 2014 THE MODELS WERE IN GOOD AGREEMENT WITH THE LARGE SCALE AND LOCAL WEATHER PATTERN FOR THE FIRST 36 HOURS OF THE FORECAST. THE NAM12...SREF...AND HRRR MODELS HAVE ALL HANDLED THE TIMING AND EVOLUTION OF A LINE OF SHOWERS AND STORMS THAT IS CURRENTLY MOVING ACROSS CENTRAL KENTUCKY AND SOUTHERN OHIO. THE NAM12 AND SREF SEEM TO DO A BETTER JOB OF HANDLING THE EVOLUTION OF THIS LINE OF SHOWERS AND STORMS AFTER SUNRISE TODAY THAN THE HRRR...SO THOSE TWO MODELS WERE USED TO CREATE THE NEW FORECAST. THE MODELS SUGGEST A STRONG COLD FRONT WILL MOVE ACROSS CENTRAL AND EASTERN KENTUCKY TODAY...WITH THE BOUNDARY EXITING THE AREA LATE THIS AFTERNOON. WIDESPREAD SHOWERS AND STORMS ARE EXPECTED TO CONTINUE FIRING ALONG AND JUST AHEAD OF THIS FRONT...WITH THE PEAK IN ACTIVITY OCCURRING BETWEEN ROUGHLY NOON AND 5 PM. THE LATEST FORECAST SOUNDINGS CONTINUE TO SUPPORT THE POTENTIAL FOR LOCALLY HEAVY RAINFALL...WITH PRECIPITABLE WATER VALUES OF AROUND 2 INCHES PERSISTING THROUGH THE OVERNIGHT HOURS. SOME OF THE STRONGER THUNDERSTORMS COULD ALSO PRODUCE GUSTY WINDS...BUT LOCALLY HEAVY RAINFALL WILL BE THE PRIMARY THREAT. THE RAIN CHANCES WILL NOT END ONCE THE FRONT HAS PASSED BY US...HOWEVER. THE BOUNDARY IS EXPECTED TO STALL ACROSS THE TENNESSEE VALLEY ON FRIDAY. WAVES OF LOW PRESSURE ARE THEN PROGGED TO MIGRATE FROM WEST TO EAST ALONG THE FRONT. THESE DISTURBANCES WILL BRING ENOUGH LIFT AND MOISTURE TO LOCATIONS SOUTH OF THE MOUNTAIN PARKWAY TO PERHAPS FIRE OFF ISOLATED TO SCATTERED RAIN SHOWERS LATE TONIGHT THROUGH THE END OF THE DAY ON FRIDAY. ONCE THE FRONT MOVES THROUGH EARLY TONIGHT...AN UNSEASONABLY COOL CANADIAN AIR MASS WILL SETTLE OVER THE AREA. THIS AIR MASS WILL BRING FALL LIKE TEMPERATURES TO EASTERN KENTUCKY TONIGHT AND FRIDAY. THE COOL WEATHER WILL FIRST BE EXPERIENCED LATE TONIGHT...AS WINDS SHIFT TO THE NORTH AND THE COOL AIR FULLY INVADES THE REGION. TONIGHTS LOWS ARE EXPECTED TO BOTTOM OUT IN THE LOW TO MID 60S FOR MOST LOCATIONS. FOLKS ALONG AND NORTH OF THE I-64 CORRIDOR MAY SEE THE MERCURY DIP INTO THE UPPER 50S BY FRIDAY MORNING. HIGH TEMPERATURES ON FRIDAY WILL LIKELY ONLY CLIMB INTO THE LOW TO MID 70S ACROSS THE AREA. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 431 AM EDT THU SEP 11 2014 THE MODELS ARE IN GOOD AGREEMENT WITH THE LONG WAVE PATTERN THROUGH THE PERIOD. PROGRESSIVE AND AMPLIFIED FLOW WILL CONTROL ACROSS THE NORTHERN HALF OF THE CONUS AS SEVERAL PASSING SHORT WAVES HELP TO REINFORCE TROUGHING ACROSS THE REGION. UPPER LEVEL RIDGING HANGING ON ACROSS THE SOUTHERN CONUS WILL GRADUALLY DAMPEN AND GET SUPPRESSED FURTHER SOUTH INTO EARLY NEXT WEEK...BEFORE CONSOLIDATING MORE ACROSS THE DESERT SOUTHWEST BY THE MIDDLE OF NEXT WEEK. FOR EASTERN KENTUCKY...THE FIRST MAIN SHORT WAVE WILL MOVE THROUGH FRIDAY NIGHT INTO SATURDAY...BRINGING A CHANCE OF SHOWERS. GENERALLY DRY WEATHER CAN BE EXPECTED FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT...AS HIGH PRESSURE TEMPORARILY BUILDS IN AT THE SURFACE. A DEEPER TROUGH AXIS...WITH SOME SURFACE DEVELOPMENT NOTED BY THE MODELS...WILL THEN AFFECT THE AREA FROM MONDAY THROUGH TUESDAY. THIS SYSTEM WILL BRING SOME RENEWED CHANCES OF SHOWERS...ALTHOUGH THERE WILL NOT BE AS MUCH LOW LEVEL MOISTURE TO WORK WITH...SO STUCK FAIRLY CLOSE TO THE BLENDED GUIDANCE ON THE POPS. DRY WEATHER WILL ENSUE ONCE AGAIN THEREAFTER...AS SURFACE HIGH PRESSURE BUILDS IN ACROSS THE OHIO VALLEY. TEMPERATURES WILL AVERAGE BELOW NORMAL THROUGH THE PERIOD...WITH HIGHS MAINLY IN THE LOW TO MID 70S AND LOWS IN THE 50S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 645 AM EDT THU SEP 11 2014 WIDESPREAD SHOWERS AND STORMS WILL LOCALLY HEAVY RAINFALL AND GUSTY WINDS ARE STILL ON TAP TODAY AT ALL FOUR TAF SITES. MVFR AND AT TIMES IFR CONDITIONS WILL BE POSSIBLE DUE TO HEAVY RAINFALL AND FOG WITH SHOWERS AND STORMS TODAY. THE RAIN IS EXPECTED TO LAST ALL DAY BEFORE TAPERING OFF THIS EVENING. WINDS ARE EXPECTED TO SHIFT TO TO THE WEST LATE THIS AFTERNOON AND THEN TO THE NORTH THIS EVENING AS THE FRONT MOVES PAST. LOW LEVEL CLOUD COVER WILL LIKELY PLAGUE THE TAF SITES THROUGH TOMORROW MORNING AS THE FRONT STALLS OUT TO OUR SOUTH AND MOIST AIR CONTINUES TO RIDE UP AND OVER THE BOUNDARY. ISOLATED RAIN SHOWERS WILL ALSO LINGER OVERNIGHT INTO EARLY TOMORROW...PARTICULARLY NEAR LOZ AND SME...WHICH WILL BE CLOSER TO THE FRONT. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HAL SHORT TERM...AR LONG TERM...GEOGERIAN AVIATION...AR
AREA FORECAST DISCUSSION
NWS JACKSON KY
645 AM EDT THU SEP 11 2014 .UPDATE... ISSUED AT 645 AM EDT THU SEP 11 2014 MADE A FEW ADJUSTMENTS TO THE FORECAST GRIDS FOR EARLY THIS MORNING BASED ON THE CURRENT RADAR TRENDS. DECIDED TO SLIGHTLY SPEED UP THE EASTWARD PROGRESSION OF SHOWERS AND STORMS THIS MORNING PER LATEST RADAR. BASED ON UPSTREAM SHOWER AND STORM FORMATION...AND THE STILL SLOW EASTWARD MOVEMENT OF THE COLD FRONT...IT STILL APPEARS THAT WIDESPREAD RAINFALL WILL OCCUR ACROSS EASTERN KENTUCKY THROUGH THIS AFTERNOON. LOCALLY HEAVY RAINFALL...AND PERHAPS SOME ISOLATED INSTANCES OF FLOODING...WILL STILL BE POSSIBLE AS NUMEROUS STORMS WILL LIKELY MOVE ACROSS THE SAME LOCATIONS THROUGHOUT THE DAY. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 323 AM EDT THU SEP 11 2014 THE MODELS WERE IN GOOD AGREEMENT WITH THE LARGE SCALE AND LOCAL WEATHER PATTERN FOR THE FIRST 36 HOURS OF THE FORECAST. THE NAM12...SREF...AND HRRR MODELS HAVE ALL HANDLED THE TIMING AND EVOLUTION OF A LINE OF SHOWERS AND STORMS THAT IS CURRENTLY MOVING ACROSS CENTRAL KENTUCKY AND SOUTHERN OHIO. THE NAM12 AND SREF SEEM TO DO A BETTER JOB OF HANDLING THE EVOLUTION OF THIS LINE OF SHOWERS AND STORMS AFTER SUNRISE TODAY THAN THE HRRR...SO THOSE TWO MODELS WERE USED TO CREATE THE NEW FORECAST. THE MODELS SUGGEST A STRONG COLD FRONT WILL MOVE ACROSS CENTRAL AND EASTERN KENTUCKY TODAY...WITH THE BOUNDARY EXITING THE AREA LATE THIS AFTERNOON. WIDESPREAD SHOWERS AND STORMS ARE EXPECTED TO CONTINUE FIRING ALONG AND JUST AHEAD OF THIS FRONT...WITH THE PEAK IN ACTIVITY OCCURRING BETWEEN ROUGHLY NOON AND 5 PM. THE LATEST FORECAST SOUNDINGS CONTINUE TO SUPPORT THE POTENTIAL FOR LOCALLY HEAVY RAINFALL...WITH PRECIPITABLE WATER VALUES OF AROUND 2 INCHES PERSISTING THROUGH THE OVERNIGHT HOURS. SOME OF THE STRONGER THUNDERSTORMS COULD ALSO PRODUCE GUSTY WINDS...BUT LOCALLY HEAVY RAINFALL WILL BE THE PRIMARY THREAT. THE RAIN CHANCES WILL NOT END ONCE THE FRONT HAS PASSED BY US...HOWEVER. THE BOUNDARY IS EXPECTED TO STALL ACROSS THE TENNESSEE VALLEY ON FRIDAY. WAVES OF LOW PRESSURE ARE THEN PROGGED TO MIGRATE FROM WEST TO EAST ALONG THE FRONT. THESE DISTURBANCES WILL BRING ENOUGH LIFT AND MOISTURE TO LOCATIONS SOUTH OF THE MOUNTAIN PARKWAY TO PERHAPS FIRE OFF ISOLATED TO SCATTERED RAIN SHOWERS LATE TONIGHT THROUGH THE END OF THE DAY ON FRIDAY. ONCE THE FRONT MOVES THROUGH EARLY TONIGHT...AN UNSEASONABLY COOL CANADIAN AIR MASS WILL SETTLE OVER THE AREA. THIS AIR MASS WILL BRING FALL LIKE TEMPERATURES TO EASTERN KENTUCKY TONIGHT AND FRIDAY. THE COOL WEATHER WILL FIRST BE EXPERIENCED LATE TONIGHT...AS WINDS SHIFT TO THE NORTH AND THE COOL AIR FULLY INVADES THE REGION. TONIGHTS LOWS ARE EXPECTED TO BOTTOM OUT IN THE LOW TO MID 60S FOR MOST LOCATIONS. FOLKS ALONG AND NORTH OF THE I-64 CORRIDOR MAY SEE THE MERCURY DIP INTO THE UPPER 50S BY FRIDAY MORNING. HIGH TEMPERATURES ON FRIDAY WILL LIKELY ONLY CLIMB INTO THE LOW TO MID 70S ACROSS THE AREA. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 431 AM EDT THU SEP 11 2014 THE MODELS ARE IN GOOD AGREEMENT WITH THE LONG WAVE PATTERN THROUGH THE PERIOD. PROGRESSIVE AND AMPLIFIED FLOW WILL CONTROL ACROSS THE NORTHERN HALF OF THE CONUS AS SEVERAL PASSING SHORT WAVES HELP TO REINFORCE TROUGHING ACROSS THE REGION. UPPER LEVEL RIDGING HANGING ON ACROSS THE SOUTHERN CONUS WILL GRADUALLY DAMPEN AND GET SUPPRESSED FURTHER SOUTH INTO EARLY NEXT WEEK...BEFORE CONSOLIDATING MORE ACROSS THE DESERT SOUTHWEST BY THE MIDDLE OF NEXT WEEK. FOR EASTERN KENTUCKY...THE FIRST MAIN SHORT WAVE WILL MOVE THROUGH FRIDAY NIGHT INTO SATURDAY...BRINGING A CHANCE OF SHOWERS. GENERALLY DRY WEATHER CAN BE EXPECTED FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT...AS HIGH PRESSURE TEMPORARILY BUILDS IN AT THE SURFACE. A DEEPER TROUGH AXIS...WITH SOME SURFACE DEVELOPMENT NOTED BY THE MODELS...WILL THEN AFFECT THE AREA FROM MONDAY THROUGH TUESDAY. THIS SYSTEM WILL BRING SOME RENEWED CHANCES OF SHOWERS...ALTHOUGH THERE WILL NOT BE AS MUCH LOW LEVEL MOISTURE TO WORK WITH...SO STUCK FAIRLY CLOSE TO THE BLENDED GUIDANCE ON THE POPS. DRY WEATHER WILL ENSUE ONCE AGAIN THEREAFTER...AS SURFACE HIGH PRESSURE BUILDS IN ACROSS THE OHIO VALLEY. TEMPERATURES WILL AVERAGE BELOW NORMAL THROUGH THE PERIOD...WITH HIGHS MAINLY IN THE LOW TO MID 70S AND LOWS IN THE 50S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 645 AM EDT THU SEP 11 2014 WIDESPREAD SHOWERS AND STORMS WILL LOCALLY HEAVY RAINFALL AND GUSTY WINDS ARE STILL ON TAP TODAY AT ALL FOUR TAF SITES. MVFR AND AT TIMES IFR CONDITIONS WILL BE POSSIBLE DUE TO HEAVY RAINFALL AND FOG WITH SHOWERS AND STORMS TODAY. THE RAIN IS EXPECTED TO LAST ALL DAY BEFORE TAPERING OFF THIS EVENING. WINDS ARE EXPECTED TO SHIFT TO TO THE WEST LATE THIS AFTERNOON AND THEN TO THE NORTH THIS EVENING AS THE FRONT MOVES PAST. LOW LEVEL CLOUD COVER WILL LIKELY PLAGUE THE TAF SITES THROUGH TOMORROW MORNING AS THE FRONT STALLS OUT TO OUR SOUTH AND MOIST AIR CONTINUES TO RIDE UP AND OVER THE BOUNDARY. ISOLATED RAIN SHOWERS WILL ALSO LINGER OVERNIGHT INTO EARLY TOMORROW...PARTICULARLY NEAR LOZ AND SME...WHICH WILL BE CLOSER TO THE FRONT. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AR SHORT TERM...AR LONG TERM...GEOGERIAN AVIATION...AR
AREA FORECAST DISCUSSION
NWS JACKSON KY
431 AM EDT THU SEP 11 2014 .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 323 AM EDT THU SEP 11 2014 THE MODELS WERE IN GOOD AGREEMENT WITH THE LARGE SCALE AND LOCAL WEATHER PATTERN FOR THE FIRST 36 HOURS OF THE FORECAST. THE NAM12...SREF...AND HRRR MODELS HAVE ALL HANDLED THE TIMING AND EVOLUTION OF A LINE OF SHOWERS AND STORMS THAT IS CURRENTLY MOVING ACROSS CENTRAL KENTUCKY AND SOUTHERN OHIO. THE NAM12 AND SREF SEEM TO DO A BETTER JOB OF HANDLING THE EVOLUTION OF THIS LINE OF SHOWERS AND STORMS AFTER SUNRISE TODAY THAN THE HRRR...SO THOSE TWO MODELS WERE USED TO CREATE THE NEW FORECAST. THE MODELS SUGGEST A STRONG COLD FRONT WILL MOVE ACROSS CENTRAL AND EASTERN KENTUCKY TODAY...WITH THE BOUNDARY EXITING THE AREA LATE THIS AFTERNOON. WIDESPREAD SHOWERS AND STORMS ARE EXPECTED TO CONTINUE FIRING ALONG AND JUST AHEAD OF THIS FRONT...WITH THE PEAK IN ACTIVITY OCCURRING BETWEEN ROUGHLY NOON AND 5 PM. THE LATEST FORECAST SOUNDINGS CONTINUE TO SUPPORT THE POTENTIAL FOR LOCALLY HEAVY RAINFALL...WITH PRECIPITABLE WATER VALUES OF AROUND 2 INCHES PERSISTING THROUGH THE OVERNIGHT HOURS. SOME OF THE STRONGER THUNDERSTORMS COULD ALSO PRODUCE GUSTY WINDS...BUT LOCALLY HEAVY RAINFALL WILL BE THE PRIMARY THREAT. THE RAIN CHANCES WILL NOT END ONCE THE FRONT HAS PASSED BY US...HOWEVER. THE BOUNDARY IS EXPECTED TO STALL ACROSS THE TENNESSEE VALLEY ON FRIDAY. WAVES OF LOW PRESSURE ARE THEN PROGGED TO MIGRATE FROM WEST TO EAST ALONG THE FRONT. THESE DISTURBANCES WILL BRING ENOUGH LIFT AND MOISTURE TO LOCATIONS SOUTH OF THE MOUNTAIN PARKWAY TO PERHAPS FIRE OFF ISOLATED TO SCATTERED RAIN SHOWERS LATE TONIGHT THROUGH THE END OF THE DAY ON FRIDAY. ONCE THE FRONT MOVES THROUGH EARLY TONIGHT...AN UNSEASONABLY COOL CANADIAN AIR MASS WILL SETTLE OVER THE AREA. THIS AIR MASS WILL BRING FALL LIKE TEMPERATURES TO EASTERN KENTUCKY TONIGHT AND FRIDAY. THE COOL WEATHER WILL FIRST BE EXPERIENCED LATE TONIGHT...AS WINDS SHIFT TO THE NORTH AND THE COOL AIR FULLY INVADES THE REGION. TONIGHTS LOWS ARE EXPECTED TO BOTTOM OUT IN THE LOW TO MID 60S FOR MOST LOCATIONS. FOLKS ALONG AND NORTH OF THE I-64 CORRIDOR MAY SEE THE MERCURY DIP INTO THE UPPER 50S BY FRIDAY MORNING. HIGH TEMPERATURES ON FRIDAY WILL LIKELY ONLY CLIMB INTO THE LOW TO MID 70S ACROSS THE AREA. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 431 AM EDT THU SEP 11 2014 THE MODELS ARE IN GOOD AGREEMENT WITH THE LONG WAVE PATTERN THROUGH THE PERIOD. PROGRESSIVE AND AMPLIFIED FLOW WILL CONTROL ACROSS THE NORTHERN HALF OF THE CONUS AS SEVERAL PASSING SHORT WAVES HELP TO REINFORCE TROUGHING ACROSS THE REGION. UPPER LEVEL RIDGING HANGING ON ACROSS THE SOUTHERN CONUS WILL GRADUALLY DAMPEN AND GET SUPPRESSED FURTHER SOUTH INTO EARLY NEXT WEEK...BEFORE CONSOLIDATING MORE ACROSS THE DESERT SOUTHWEST BY THE MIDDLE OF NEXT WEEK. FOR EASTERN KENTUCKY...THE FIRST MAIN SHORT WAVE WILL MOVE THROUGH FRIDAY NIGHT INTO SATURDAY...BRINGING A CHANCE OF SHOWERS. GENERALLY DRY WEATHER CAN BE EXPECTED FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT...AS HIGH PRESSURE TEMPORARILY BUILDS IN AT THE SURFACE. A DEEPER TROUGH AXIS...WITH SOME SURFACE DEVELOPMENT NOTED BY THE MODELS...WILL THEN AFFECT THE AREA FROM MONDAY THROUGH TUESDAY. THIS SYSTEM WILL BRING SOME RENEWED CHANCES OF SHOWERS...ALTHOUGH THERE WILL NOT BE AS MUCH LOW LEVEL MOISTURE TO WORK WITH...SO STUCK FAIRLY CLOSE TO THE BLENDED GUIDANCE ON THE POPS. DRY WEATHER WILL ENSUE ONCE AGAIN THEREAFTER...AS SURFACE HIGH PRESSURE BUILDS IN ACROSS THE OHIO VALLEY. TEMPERATURES WILL AVERAGE BELOW NORMAL THROUGH THE PERIOD...WITH HIGHS MAINLY IN THE LOW TO MID 70S AND LOWS IN THE 50S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 140 AM EDT THU SEP 11 2014 VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH AROUND 11Z THIS MORNING AT THE PRIMARY TAF SITES. IT LOOKS LIKE THE FIRST SHOWERS AND STORMS WILL BEGIN MOVING ACROSS THE TAF SITES BEGINNING AT 10Z FOR SME...11Z FOR LOZ...12Z FOR JKL...AND 13Z FOR SJS. MVFR TO IFR CONDITIONS WILL BE POSSIBLE WITH ANY THUNDERSTORMS OR INTENSE SHOWERS. LOCALLY HEAVY RAINFALL AND LIGHTNING WILL THE PRIMARY CONCERNS FOR AVIATORS WITH ANY SHOWERS OR STORMS. THE COLD FRONT THAT IS PRODUCING THE PRECIPITATION SHOULD BE THROUGH THE AREA BY AROUND 0Z THIS EVENING...WITH WINDS SHIFTING FROM SOUTHWEST TO WEST BEHIND THE FRONT. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...AR LONG TERM...GEOGERIAN AVIATION...AR
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
323 AM EDT THU SEP 11 2014 .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 3 23AM EDT THU SEP 11 2014 THE MODELS WERE IN GOOD AGREEMENT WITH THE LARGE SCALE AND LOCAL WEATHER PATTERN FOR THE FIRST 36 HOURS OF THE FORECAST. THE NAM12...SREF...AND HRRR MODELS HAVE ALL HANDLED THE TIMING AND EVOLUTION OF A LINE OF SHOWERS AND STORMS THAT IS CURRENTLY MOVING ACROSS CENTRAL KENTUCKY AND SOUTHERN OHIO. THE NAM12 AND SREF SEEM TO DO A BETTER JOB OF HANDLING THE EVOLUTION OF THIS LINE OF SHOWERS AND STORMS AFTER SUNRISE TODAY THAN THE HRRR...SO THOSE TWO MODELS WERE USED TO CREATE THE NEW FORECAST. THE MODELS SUGGEST A STRONG COLD FRONT WILL MOVE ACROSS CENTRAL AND EASTERN KENTUCKY TODAY...WITH THE BOUNDARY EXITING THE AREA LATE THIS AFTERNOON. WIDESPREAD SHOWERS AND STORMS ARE EXPECTED TO CONTINUE FIRING ALONG AND JUST AHEAD OF THIS FRONT...WITH THE PEAK IN ACTIVITY OCCURRING BETWEEN ROUGHLY NOON AND 5 PM. THE LATEST FORECAST SOUNDINGS CONTINUE TO SUPPORT THE POTENTIAL FOR LOCALLY HEAVY RAINFALL...WITH PRECIPITABLE WATER VALUES OF AROUND 2 INCHES PERSISTING THROUGH THE OVERNIGHT HOURS. SOME OF THE STRONGER THUNDERSTORMS COULD ALSO PRODUCE GUSTY WINDS...BUT LOCALLY HEAVY RAINFALL WILL BE THE PRIMARY THREAT. THE RAIN CHANCES WILL NOT END ONCE THE FRONT HAS PASSED BY US...HOWEVER. THE BOUNDARY IS EXPECTED TO STALL ACROSS THE TENNESSEE VALLEY ON FRIDAY. WAVES OF LOW PRESSURE ARE THEN PROGGED TO MIGRATE FROM WEST TO EAST ALONG THE FRONT. THESE DISTURBANCES WILL BRING ENOUGH LIFT AND MOISTURE TO LOCATIONS SOUTH OF THE MOUNTAIN PARKWAY TO PERHAPS FIRE OFF ISOLATED TO SCATTERED RAIN SHOWERS LATE TONIGHT THROUGH THE END OF THE DAY ON FRIDAY. ONCE THE FRONT MOVES THROUGH EARLY TONIGHT...AN UNSEASONABLY COOL CANADIAN AIR MASS WILL SETTLE OVER THE AREA. THIS AIR MASS WILL BRING FALL LIKE TEMPERATURES TO EASTERN KENTUCKY TONIGHT AND FRIDAY. THE COOL WEATHER WILL FIRST BE EXPERIENCED LATE TONIGHT...AS WINDS SHIFT TO THE NORTH AND THE COOL AIR FULLY INVADES THE REGION. TONIGHTS LOWS ARE EXPECTED TO BOTTOM OUT IN THE LOW TO MID 60S FOR MOST LOCATIONS. FOLKS ALONG AND NORTH OF THE I-64 CORRIDOR MAY SEE THE MERCURY DIP INTO THE UPPER 50S BY FRIDAY MORNING. HIGH TEMPERATURES ON FRIDAY WILL LIKELY ONLY CLIMB INTO THE LOW TO MID 70S ACROSS THE AREA. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 323 AM EDT THU SEP 11 2014 AN EXTENDED DISCUSSION WILL BE ISSUED SHORTLY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 140 AM EDT THU SEP 11 2014 VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH AROUND 11Z THIS MORNING AT THE PRIMARY TAF SITES. IT LOOKS LIKE THE FIRST SHOWERS AND STORMS WILL BEGIN MOVING ACROSS THE TAF SITES BEGINNING AT 10Z FOR SME...11Z FOR LOZ...12Z FOR JKL...AND 13Z FOR SJS. MVFR TO IFR CONDITIONS WILL BE POSSIBLE WITH ANY THUNDERSTORMS OR INTENSE SHOWERS. LOCALLY HEAVY RAINFALL AND LIGHTNING WILL THE PRIMARY CONCERNS FOR AVIATORS WITH ANY SHOWERS OR STORMS. THE COLD FRONT THAT IS PRODUCING THE PRECIPITATION SHOULD BE THROUGH THE AREA BY AROUND 0Z THIS EVENING...WITH WINDS SHIFTING FROM SOUTHWEST TO WEST BEHIND THE FRONT. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...AR LONG TERM...GEOGERIAN AVIATION...AR
AREA FORECAST DISCUSSION
NWS JACKSON KY
306 AM EDT THU SEP 11 2014 .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 305 AM EDT THU SEP 11 2014 THE MODELS WERE IN GOOD AGREEMENT WITH THE LARGE SCALE AND LOCAL WEATHER PATTERN FOR THE FIRST 36 HOURS OF THE FORECAST. THE NAM12...SREF...AND HRRR MODELS HAVE ALL HANDLED THE TIMING AND EVOLUTION OF A LINE OF SHOWERS AND STORMS THAT IS CURRENTLY MOVING ACROSS CENTRAL KENTUCKY AND SOUTHERN OHIO. THE NAM12 AND SREF SEEM TO DO A BETTER JOB OF HANDLING THE EVOLUTION OF THIS LINE OF SHOWERS AND STORMS AFTER SUNRISE TODAY THAN THE HRRR...SO THOSE TWO MODELS WERE USED TO CREATE THE NEW FORECAST. THE MODELS SUGGEST A STRONG COLD FRONT WILL MOVE ACROSS CENTRAL AND EASTERN KENTUCKY TODAY...WITH THE BOUNDARY EXITING THE AREA LATE THIS AFTERNOON. WIDESPREAD SHOWERS AND STORMS ARE EXPECTED TO CONTINUE FIRING ALONG AND JUST AHEAD OF THIS FRONT...WITH THE PEAK IN ACTIVITY OCCURRING BETWEEN ROUGHLY NOON AND 5 PM. THE LATEST FORECAST SOUNDINGS CONTINUE TO SUPPORT THE POTENTIAL FOR LOCALLY HEAVY RAINFALL...WITH PRECIPITABLE WATER VALUES OF AROUND 2 INCHES PERSISTING THROUGH THE OVERNIGHT HOURS. SOME OF THE STRONGER THUNDERSTORMS COULD ALSO PRODUCE GUSTY WINDS...BUT LOCALLY HEAVY RAINFALL WILL BE THE PRIMARY THREAT. ONCE THE FRONT MOVES THROUGH EARLY TONIGHT...AN UNSEASONABLY COOL CANADIAN AIR MASS WILL SETTLE OVER THE AREA. THIS AIR MASS WILL BRING FALL LIKE TEMPERATURES TO EASTERN KENTUCKY TONIGHT AND FRIDAY. THE COOL WEATHER WILL FIRST BE EXPERIENCED LATE TONIGHT...AS WINDS SHIFT TO THE NORTH AND THE COOL AIR FULL INVADES THE REGIONS. TONIGHTS LOWS ARE EXPECTED TO BOTTOM OUT IN THE LOW TO MID 60S FOR MOST LOCATIONS. FOLKS ALONG AND NORTH OF THE I-64 CORRIDOR MAY SEE THE MERCURY DIP INTO THE UPPER 50S BY FRIDAY MORNING. HIGH TEMPERATURES ON FRIDAY WILL LIKELY ONLY CLIMB INTO THE LOW TO MID 70S ACROSS THE AREA. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 305 AM EDT THU SEP 11 2014 AN EXTENDED DISCUSSION WILL BE ISSUED SHORTLY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 140 AM EDT THU SEP 11 2014 VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH AROUND 11Z THIS MORNING AT THE PRIMARY TAF SITES. IT LOOKS LIKE THE FIRST SHOWERS AND STORMS WILL BEGIN MOVING ACROSS THE TAF SITES BEGINNING AT 10Z FOR SME...11Z FOR LOZ...12Z FOR JKL...AND 13Z FOR SJS. MVFR TO IFR CONDITIONS WILL BE POSSIBLE WITH ANY THUNDERSTORMS OR INTENSE SHOWERS. LOCALLY HEAVY RAINFALL AND LIGHTNING WILL THE PRIMARY CONCERNS FOR AVIATORS WITH ANY SHOWERS OR STORMS. THE COLD FRONT THAT IS PRODUCING THE PRECIPITATION SHOULD BE THROUGH THE AREA BY AROUND 0Z THIS EVENING...WITH WINDS SHIFTING FROM SOUTHWEST TO WEST BEHIND THE FRONT. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...AR LONG TERM...GEOGERIAN AVIATION...AR
AREA FORECAST DISCUSSION
NWS JACKSON KY
140 AM EDT THU SEP 11 2014 .UPDATE... ISSUED AT 140 AM EDT THU SEP 11 2014 INGESTED THE LATEST OBSERVATIONAL DATA INTO THE FORECAST GRIDS TO ESTABLISH NEW TRENDS AND FRESHEN UP THE EXISTING FORECAST FOR THE REST OF THE NIGHT. THE CHANGES MADE TO THE GRIDS WERE MINOR ENOUGH TO NOT WARRANT A FORECAST UPDATE AT THIS TIME. UPDATE ISSUED AT 1049 PM EDT WED SEP 10 2014 HAVE SLOWED DOWN THE PRECIPITATION ONSET JUST A BIT MORE BASED ON THE LATEST RADAR AND HRRR MODEL TRENDS. THE LATEST IR SATELLITE SHOWS QUITE A BIT OF CLEARING ACROSS OUR AREA CURRENTLY...AND A FEW OF THE NORMALLY COOLER VALLEYS HAVE ALREADY DIPPED INTO THE UPPER 60S. CLOUDS SHOULD FILL IN NICELY BETWEEN 06 AND 12Z...HOWEVER DID LOWER SOME OF THE LOW TEMPERATURES IN THE EAST WHERE SOME DECENT CLEARING WILL HANG ON FOR THE NEXT 2 TO 3 HOURS...ALLOWING FOR ANOTHER DEGREE DROP OFF OR SO. UPDATES HAVE BEEN SENT. UPDATE ISSUED AT 820 PM EDT WED SEP 10 2014 BASED ON OBS AND AFTERNOON MODEL RUNS...HAVE SLOWED THE ARRIVAL OF PRECIP TONIGHT...BUT THE OVERNIGHT REMAINS UNCHANGED...WITH THE SAME 12 HOUR POPS FOR THE PERIOD. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 400 PM EDT WED SEP 10 2014 MODELS ARE IN GOOD AGREEMENT FOR THE WEATHER EVENT TO AFFECT US DURING THE PERIOD. A COLD FRONT WILL MOVE SOUTHEAST...PASSING THROUGH KY ON THURSDAY AND THURSDAY EVENING. SHOWERS WILL OCCUR NEAR AND AHEAD OF THE FRONT...ENTERING THE JKL FORECAST AREA OVERNIGHT...WITH MOST OF THE PRECIP EXITING INTO TN AND VA BY THURSDAY EVENING. LIMITED HEATING IS EXPECTED ON THURSDAY AND LAPSE RATES WILL BE NEAR MOIST ADIABATIC...AND WINDS ALOFT ONLY MODEST. SO...DESPITE AMPLE MOISTURE...CONVECTION SHOULD NOT BE TOO RAMBUNCTIOUS. PRECIPITABLE WATER WILL BE NEAR 2 INCHES...AND LOCALLY HEAVY RAINFALL MAY OCCUR WHERE CELLS TRAIN...BUT THE CELLS WILL AT LEAST BE MOVING ALONG. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 400 PM EDT WED SEP 10 2014 ATTENTION TURNS TO A SIGNIFICANT SHORT WAVE THAT WILL MOVE FROM THE NORTH PLAINS EAST TO THE GREAT LAKES FRIDAY INTO SATURDAY. THIS WAVE MOVES PAST EAST KENTUCKY DURING THE DAY SATURDAY FOLLOWED BY FLATTER...BUT STILL RATHER FAST...FLOW INTO THE DAY SUNDAY. FOR THIS TIME FRAME...THROUGH THE DAY TUESDAY...WILL FAVOR A GENERAL MODEL BLEND. THE MODELS KEEP THIS SORT OF ABNORMALLY COOL PATTERN GOING THROUGH THEIR RUN SUGGESTING THAT OUR DAYS OF SUMMER-LIKE WEATHER MAY BE OVER FOR THE SEASON...THOUGH BEING KENTUCKY IT WOULD NOT TAKE MUCH OF A WIGGLE TO BRING SOME SOUTHERN WARMTH BACK NORTH. WE SHALL SEE... THE RUB WITH THE FORECAST THROUGH THE FIRST PART OF THE WEEKEND WILL BE THE POSSIBILITY THAT THE FRONT DOES NOT COMPLETELY CLEAR THE CWA AND LINGERS CLOSE ENOUGH FOR SHOWERS TO ACCOMPANY THE FALL-LIKE COOL DOWN FOR OUR SOUTHERN MOST LOCATIONS. THE SHOWER THREAT INCREASES DURING FRIDAY NIGHT THROUGH THE DAY SATURDAY AS A REINFORCING COLD FRONT MOVES THROUGH THE OHIO VALLEY. THIS FRONT SHOULD HAVE A BETTER PUSH BEHIND IT AND HELP TO CLEAR OUT LINGERING SHOWER THREATS FOR AT LEAST A DAY OR SO ACROSS ALL OF THE AREA. THE HIGH PRESSURE ASSOCIATED WITH THIS COOL BLAST WILL MODERATE SOMEWHAT AND MOVE BY TO THE NORTHEAST BY MONDAY MORNING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 140 AM EDT THU SEP 11 2014 VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH AROUND 11Z THIS MORNING AT THE PRIMARY TAF SITES. IT LOOKS LIKE THE FIRST SHOWERS AND STORMS WILL BEGIN MOVING ACROSS THE TAF SITES BEGINNING AT 10Z FOR SME...11Z FOR LOZ...12Z FOR JKL...AND 13Z FOR SJS. MVFR TO IFR CONDITIONS WILL BE POSSIBLE WITH ANY THUNDERSTORMS OR INTENSE SHOWERS. LOCALLY HEAVY RAINFALL AND LIGHTNING WILL THE PRIMARY CONCERNS FOR AVIATORS WITH ANY SHOWERS OR STORMS. THE COLD FRONT THAT IS PRODUCING THE PRECIPITATION SHOULD BE THROUGH THE AREA BY AROUND 0Z THIS EVENING...WITH WINDS SHIFTING FROM SOUTHWEST TO WEST BEHIND THE FRONT. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AR SHORT TERM...HAL LONG TERM...JKL AVIATION...AR
AREA FORECAST DISCUSSION...UPDATED
NWS PADUCAH KY
1141 PM CDT Wed Sep 10 2014 .UPDATE... Issued at 1141 PM CDT WED SEP 10 2014 Updated the aviation discussion for the 06Z TAF issuance. && .SHORT TERM...(Tonight through Friday night) Issued at 323 PM CDT WED SEP 10 2014 The showers are still trying to dissipate over southern Illinois, and now a tiny heavy shower has develop near KSAR in the last scan or two. The latest HRRR indicates that there may be some heavier convective elements with this pesky band of showers, as it moves eastward toward the EVV Tri State late this afternoon. Widespread cloud cover has stunted surface-based instability today, and this may help keep the severe weather threat in check as we move into this evening. Model soundings from southern Illinois and southwest Indiana reveal very weak lapse rates, and overall instability. There is decent low-level shear, possibly enough to support a few rotating updrafts. The low-level shear will weaken through the evening, and there is little shear above 3 km. Cannot rule out a stray severe thunderstorm, especially if it can display supercellular characteristics. Damaging winds still appear to be the primary concern, but large hail and a brief tornado cannot be ruled out. Precipitable water values are well above 2 inches, and this could lead to some torrential rainfall. Generally followed HPC QPF through Thursday, and this yields 1.5-2" over much of the area, with the possible exception of the far southeast corner of the forecast area. 1-hour and 3-hour Flash flood Guidance is well over 2", so will not be issuing a Flash Flood Watch at this time. Some nuisance flooding in low-lying and poorly draining areas is possible, but major problems are not expected. The heaviest rains will be waning over the southern half of the area toward sunrise. Still not sure when/where convective initiation will occur, but the latest HRRR runs have been consistent and developing scattered convection across northern portions of southeast Missouri into southern Illinois by 00Z. Convection currently developing along the cold front from west central Illinois into central Missouri is moving east and should not pose any immediate concern for our region, but figure that the convection will fill in between it and our scattered convection through the evening. Will keep some decent PoPs in the southeast Thursday morning, but it should be drying out over most areas in the afternoon. Thursday night and Friday morning should be dry, but as the next rather sharp upper-level storm system rotates eastward out of the central/northern Plains, would not be surprised to see some showers develop, as moisture is drawn back northward over the shallow Canadian airmass. This would primarily be in the south Friday afternoon, and then throughout the area Friday night. Still don`t think there will be much precipitation, but a slight chance of showers seems reasonable for both periods. As for temperatures, stayed close to the consensus of all guidance for lows tonight with the frontal passage. With clouds, precipitation and cool advection, went under guidance in the southeast Thursday. Went near consensus for lows Thursday night, and then went below guidance Friday and near or just above it Friday night. .LONG TERM...(Saturday through Wednesday) Issued at 323 PM CDT WED SEP 10 2014 Surface high pressure will build into the area on Saturday, providing much drier air and lowering temperatures. The center of the high will pass over the Great Lakes region and then move into the New England states. Our region should remain dry through the weekend though as weak high pressure continues to stay situated over us. Models try and bring a front into the area on Monday. The front weakens substantially as it arrives Monday into Monday night, so chances for precipitation appear minimal at this time but cloud cover should increase. Most of the upper level dynamics and moisture look to be to the north of our area. However, we will have to watch Monday night, as a few of the GFS ensemble members and the 12Z Euro are hinting that this front could produce some light precipitation, especially in our northwestern counties. Even the operational GFS indicates lower level moisture increasing by Monday night. For Tuesday, models differ on the degree of dry air filtering into the area, in association with the area of high pressure that moves toward us. The 12Z GFS is much more robust in scouring out the moisture while the 00Z ECMWF seems to keep plenty of moisture lingering until Wednesday. The 12Z run of the ECMWF is a bit more pronounced with drying us out now but still not as much as the GFS. Nevertheless, it looks like we`ll be dry on Tuesday. On Wednesday, the GFS starts to bring better moisture back into the area from the west and even hints at possible precipitation chances out in SEMO as well. However, the 12Z run was the only run that was this quick in bringing precipitation back in and even the 12Z ECMWF was dry. Temperatures will be coolest on Saturday and remain in the 70s for the majority of the extended period. There might be a few places that reach in the lower 80s by next week. Lows will generally be in the 50s but some upper 40s might be attainable on Saturday night especially in the north. && .AVIATION... Issued at 1141 PM CDT WED SEP 10 2014 With the passage of a strong cold front, showers and thunderstorms producing IFR/MVFR conditions will continue across all TAF sites through the first third of the period. Afer the precipitation ends. MVFR cigs will continue through 18-20Z, then VFR. Winds will become northwest AOB 10 knots in the wake of the front through the first half of the period, then veer around to the north. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ AVIATION/PUBLIC...JP
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1015 PM CDT FRI SEP 12 2014 .DISCUSSION... COLD FRONT SOUTH OF INTERSTATE 20 AND NEARING THE SOUTHERN PARTS OF EAST AND NORTHEAST TEXAS ACROSS LOWER PARTS OF NORTHWEST AND NORTH CENTRAL LOUISIANA LATE THIS EVENING. RAIN AND EMBEDDED HEAVIER SHOWERS CONTINUED ALONG AND IN WAKE OF THE COLD FRONT AS MOISTURE LIFTS NEAR THE BOUNDARY AND COOLS IN THE COOLER AIR TO THE RADAR OF THE BOUNDARY. HAVE REMOVED THUNDERSTORMS FROM THE WORDING OF THE ZONES FOR THE REST OF TONIGHT AND INTO TOMORROW. SOME ISOLATED THUNDERSTORMS MAY OCCUR BUT MOST LOCATIONS WILL NOT HAVE THUNDERSTORMS. RAIN WILL TAPER OFF FROM NORTHWEST TO SOUTHEAST. ADJUSTED THE TEMPERATURES LOWER FOR PARTS OF EAST AND NORTHEAST TEXAS AND SOUTHEAST OKLAHOMA...WHERE COLD AIR WILL MORE PRONE TO ENTER THE REGION. /06/ && .PREV DISCUSSION... /ISSUED 659 PM CDT FRI SEP 12 2014/ AVIATION... FOR THE 13/00Z TAFS...A BAND OF SHWRS/TSTMS CONTINUES TO SLOWLY MOVE NWD ACROSS E TX/CNTRL LA BUT THE OVERALL INTENSITY OF THE CONVECTION IS GRADUALLY DIMINISHING. SCT SHWRS WILL LIKELY PERSIST THROUGH SATURDAY AFTERNOON...MAINLY S OF I-20...BUT WHETHER OR NOT THE PRECIP ACTUALLY AFFECTS ANY OF THE TAF SITES IS MORE UNCERTAIN. BEST RAIN CHANCES FOR THIS PERIOD SHOULD BE AT KLFK AS COOLER AND DRIER AIR SLOWLY WORKS INTO THE AREA FROM THE NORTH. CIGS EXPECTED TO FALL INTO THE MVFR/IFR RANGE DURING THE OVERNIGHT HRS WITH VERY LITTLE IMPROVEMENT DURING THE DAY SATURDAY. TIGHT PRESSURE GRADIENT BEHIND THE COLD FRONT WILL KEEP NLY WINDS AROUND 10 KTS WITH A FEW HIGHER GUSTS BUT SPEEDS SHOULD DIMINISH SOMEWHAT SATURDAY AS A SFC HIGH BUILDS SWD AND THE PRESSURE GRADIENT RELAXES. /09/ PREV DISCUSSION... /ISSUED 348 PM CDT FRI SEP 12 2014/ DISCUSSION... OUR WEAK COLD FRONT REMAINS STATIONARY JUST S OF THE I-20 CORRIDOR OF E TX/N LA THIS AFTERNOON...WITH A LARGE SUCKER HOLE RECENTLY OPENING UP ACROSS NW LA. TEMPS IN THESE AREAS HAVE WARMED INTO THE LOWER/MID 80S THIS AFTERNOON...BUT TEMPS REMAIN MUCH COOLER UNDER THE LOW STRATUS FARTHER W AND N. AS EXPECTED...SCT CONVECTION HAS DEVELOPED ALONG THE FRONTAL ZONE OVER DEEP E TX...WITH THE WEAK SEABREEZE APPROACHING THIS AREA AS WELL AS WCNTRL LA FROM SE TX/SW LA. BELIEVE THAT THIS CONVECTION WILL CONTINUE THROUGH A PORTION OF THIS EVENING BEFORE DIMINISHING WITH THE LOSS OF HEATING/INSTABILITY...WITH THE FRONTAL BNDRY EXPECTED TO SLOWLY DRIFT BACK S ACROSS THIS AREA AND THE SRN SECTIONS OF NCNTRL LA THIS EVENING/OVERNIGHT. THE HRRR AND TO SOME EXTENT...THE 12Z WRF DOES INDICATE THE ONGOING CONVECTION POSSIBLY BUILDING BACK A LITTLE FARTHER NNE TO NEAR/JUST S OF THE I-20 CORRIDOR OF E TX/NW LA THIS EVENING...WITH ONLY ISOLATED -SHRA EXPECTED FARTHER N CLOSER TO THE WEAK 850MB TROUGH AS IT REMAINS JUST N OF THE REGION OVER SE OK/WRN AND CNTRL AR. DID MAINTAIN HIGH CHANCE POPS FOR AREAS NEAR/S OF THE FRONT THIS EVENING...LOWERING POPS A TAD LATE AS THE CONVECTION SHOULD WANE ONCE OVERALL FORCING WEAKENS. SHOULD SEE A WIDE RANGE IN MIN TEMPS OVERNIGHT GIVEN THE SHALLOW NATURE OF THE POST-FRONTAL AIR MASS...WITH TEMPS POSSIBLY FALLING INTO THE UPPER 50S OVER SE OK/SW AR. THE WEAK COLD FRONT IS EXPECTED TO NEAR THE COAST AROUND 12Z SATURDAY...WITH THE POST-FRONTAL STRATUS HOLDING TOUGH THROUGH THE DAY. GIVEN THE DEPTH OF THE MOISTURE IN PLACE...DID INSERT SLIGHT CHANCE POPS AREAWIDE SATURDAY AS ANY WEAK FORCING WILL EASILY RESULT IN -SHRA DEVELOPMENT...WITH DAYTIME TEMPS ONLY RISING 10 DEGREES OR SO FROM THE MORNING LOWS. THE LOW STRATUS SHOULD BEGIN TO SLOWLY LIFT SUNDAY...POSSIBLY SCATTERING OUT IN THE AFTERNOON OVER PORTIONS OF THE REGION. THIS SHOULD RESULT IN MODERATING TEMPS...ALTHOUGH SFC RIDGING IN PLACE WILL MAINTAIN ABNORMALLY LOW DEWPOINTS AND COMFORTABLE RH/S FOR THIS TIME OF YEAR. SHOULD BEGIN TO SEE A RETURN OF HIGHER RH/S BY TUESDAY AS THE BROAD UPPER LEVEL LOW/TROPICAL WAVE...NOW OVER SRN FL...BEGINS TO SHIFT W ACROSS THE GULF OF MX THIS WEEKEND AND POSSIBLY IMPACT THE TX COAST. ATTM...ENOUGH SHEAR ALOFT SHOULD KEEP THIS SYSTEM FROM INTENSIFYING THIS WEEKEND AND EARLY NEXT WEEK...ALTHOUGH IT WILL HELP ENHANCE THE SEABREEZE AS IT MOVES INLAND ACROSS SE AND DEEP E TX/SRN AND CNTRL LA TUESDAY. IN ADDITION...A SHORTWAVE IN THE NW FLOW ALOFT WILL DROP SE ACROSS THE REGION TUESDAY AS WELL...WHICH COULD FURTHER ENHANCE FORCING OVER THE SRN SECTIONS OF THE REGION. HAVE INCREASED POPS TO MID CHANCE S OF I-20 TUESDAY...WITH CONVECTION DIMINISHING TUESDAY NIGHT/WEDNESDAY AS DRIER AIR ALOFT MIXES SE IN WAKE OF THIS SHORTWAVE. A DRY NW FLOW LOOKS TO PERSIST THROUGHOUT THE REMAINDER OF THE WEEK AS UPPER LEVEL RIDGING BUILDS OVER THE DESERT SW AND THE ROCKIES. TEMPS SHOULD BE NEAR CLIMO THROUGH THE PERIOD AS WELL. PRELIMS TO FOLLOW BELOW... 15 && .PRELIMINARY POINT TEMPS/POPS... SHV 64 76 61 85 66 / 30 20 10 10 10 MLU 64 79 61 84 65 / 50 20 10 10 10 DEQ 58 71 57 79 62 / 20 10 10 10 10 TXK 60 73 58 81 63 / 20 20 10 10 10 ELD 61 74 57 81 62 / 30 20 10 10 10 TYR 62 75 61 85 68 / 30 20 10 10 10 GGG 64 76 61 85 66 / 40 20 10 10 10 LFK 67 80 64 88 68 / 60 30 10 10 10 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...NONE. LA...NONE. OK...NONE. TX...NONE. && $$ 06
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
659 PM CDT FRI SEP 12 2014 .AVIATION... FOR THE 13/00Z TAFS...A BAND OF SHWRS/TSTMS CONTINUES TO SLOWLY MOVE NWD ACROSS E TX/CNTRL LA BUT THE OVERALL INTENSITY OF THE CONVECTION IS GRADUALLY DIMINISHING. SCT SHWRS WILL LIKELY PERSIST THROUGH SATURDAY AFTERNOON...MAINLY S OF I-20...BUT WHETHER OR NOT THE PRECIP ACTUALLY AFFECTS ANY OF THE TAF SITES IS MORE UNCERTAIN. BEST RAIN CHANCES FOR THIS PERIOD SHOULD BE AT KLFK AS COOLER AND DRIER AIR SLOWLY WORKS INTO THE AREA FROM THE NORTH. CIGS EXPECTED TO FALL INTO THE MVFR/IFR RANGE DURING THE OVERNIGHT HRS WITH VERY LITTLE IMPROVEMENT DURING THE DAY SATURDAY. TIGHT PRESSURE GRADIENT BEHIND THE COLD FRONT WILL KEEP NLY WINDS AROUND 10 KTS WITH A FEW HIGHER GUSTS BUT SPEEDS SHOULD DIMINISH SOMEWHAT SATURDAY AS A SFC HIGH BUILDS SWD AND THE PRESSURE GRADIENT RELAXES. /09/ && .PREV DISCUSSION... /ISSUED 348 PM CDT FRI SEP 12 2014/ DISCUSSION... OUR WEAK COLD FRONT REMAINS STATIONARY JUST S OF THE I-20 CORRIDOR OF E TX/N LA THIS AFTERNOON...WITH A LARGE SUCKER HOLE RECENTLY OPENING UP ACROSS NW LA. TEMPS IN THESE AREAS HAVE WARMED INTO THE LOWER/MID 80S THIS AFTERNOON...BUT TEMPS REMAIN MUCH COOLER UNDER THE LOW STRATUS FARTHER W AND N. AS EXPECTED...SCT CONVECTION HAS DEVELOPED ALONG THE FRONTAL ZONE OVER DEEP E TX...WITH THE WEAK SEABREEZE APPROACHING THIS AREA AS WELL AS WCNTRL LA FROM SE TX/SW LA. BELIEVE THAT THIS CONVECTION WILL CONTINUE THROUGH A PORTION OF THIS EVENING BEFORE DIMINISHING WITH THE LOSS OF HEATING/INSTABILITY...WITH THE FRONTAL BNDRY EXPECTED TO SLOWLY DRIFT BACK S ACROSS THIS AREA AND THE SRN SECTIONS OF NCNTRL LA THIS EVENING/OVERNIGHT. THE HRRR AND TO SOME EXTENT...THE 12Z WRF DOES INDICATE THE ONGOING CONVECTION POSSIBLY BUILDING BACK A LITTLE FARTHER NNE TO NEAR/JUST S OF THE I-20 CORRIDOR OF E TX/NW LA THIS EVENING...WITH ONLY ISOLATED -SHRA EXPECTED FARTHER N CLOSER TO THE WEAK 850MB TROUGH AS IT REMAINS JUST N OF THE REGION OVER SE OK/WRN AND CNTRL AR. DID MAINTAIN HIGH CHANCE POPS FOR AREAS NEAR/S OF THE FRONT THIS EVENING...LOWERING POPS A TAD LATE AS THE CONVECTION SHOULD WANE ONCE OVERALL FORCING WEAKENS. SHOULD SEE A WIDE RANGE IN MIN TEMPS OVERNIGHT GIVEN THE SHALLOW NATURE OF THE POST-FRONTAL AIR MASS...WITH TEMPS POSSIBLY FALLING INTO THE UPPER 50S OVER SE OK/SW AR. THE WEAK COLD FRONT IS EXPECTED TO NEAR THE COAST AROUND 12Z SATURDAY...WITH THE POST-FRONTAL STRATUS HOLDING TOUGH THROUGH THE DAY. GIVEN THE DEPTH OF THE MOISTURE IN PLACE...DID INSERT SLIGHT CHANCE POPS AREAWIDE SATURDAY AS ANY WEAK FORCING WILL EASILY RESULT IN -SHRA DEVELOPMENT...WITH DAYTIME TEMPS ONLY RISING 10 DEGREES OR SO FROM THE MORNING LOWS. THE LOW STRATUS SHOULD BEGIN TO SLOWLY LIFT SUNDAY...POSSIBLY SCATTERING OUT IN THE AFTERNOON OVER PORTIONS OF THE REGION. THIS SHOULD RESULT IN MODERATING TEMPS...ALTHOUGH SFC RIDGING IN PLACE WILL MAINTAIN ABNORMALLY LOW DEWPOINTS AND COMFORTABLE RH/S FOR THIS TIME OF YEAR. SHOULD BEGIN TO SEE A RETURN OF HIGHER RH/S BY TUESDAY AS THE BROAD UPPER LEVEL LOW/TROPICAL WAVE...NOW OVER SRN FL...BEGINS TO SHIFT W ACROSS THE GULF OF MX THIS WEEKEND AND POSSIBLY IMPACT THE TX COAST. ATTM...ENOUGH SHEAR ALOFT SHOULD KEEP THIS SYSTEM FROM INTENSIFYING THIS WEEKEND AND EARLY NEXT WEEK...ALTHOUGH IT WILL HELP ENHANCE THE SEABREEZE AS IT MOVES INLAND ACROSS SE AND DEEP E TX/SRN AND CNTRL LA TUESDAY. IN ADDITION...A SHORTWAVE IN THE NW FLOW ALOFT WILL DROP SE ACROSS THE REGION TUESDAY AS WELL...WHICH COULD FURTHER ENHANCE FORCING OVER THE SRN SECTIONS OF THE REGION. HAVE INCREASED POPS TO MID CHANCE S OF I-20 TUESDAY...WITH CONVECTION DIMINISHING TUESDAY NIGHT/WEDNESDAY AS DRIER AIR ALOFT MIXES SE IN WAKE OF THIS SHORTWAVE. A DRY NW FLOW LOOKS TO PERSIST THROUGHOUT THE REMAINDER OF THE WEEK AS UPPER LEVEL RIDGING BUILDS OVER THE DESERT SW AND THE ROCKIES. TEMPS SHOULD BE NEAR CLIMO THROUGH THE PERIOD AS WELL. PRELIMS TO FOLLOW BELOW... 15 && .PRELIMINARY POINT TEMPS/POPS... SHV 65 76 61 85 66 / 30 20 10 10 10 MLU 65 77 61 84 65 / 30 20 10 10 10 DEQ 59 71 57 79 62 / 30 20 10 10 10 TXK 60 72 58 81 63 / 30 20 10 10 10 ELD 61 74 57 81 62 / 30 20 10 10 10 TYR 63 74 61 85 68 / 40 20 10 10 10 GGG 65 75 61 85 66 / 40 20 10 10 10 LFK 69 80 64 88 68 / 50 30 10 10 10 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...NONE. LA...NONE. OK...NONE. TX...NONE. && $$ 09
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1245 PM CDT THU SEP 11 2014 .AVIATION... COLD FRONT IS WRAPPING THE OUACHITAS AND DEEP CONVECTION REMAINS NORTH OF I-30 WITH AN OUTFLOW FROM AR INTO I-20 OF LA DVLPG SMALL CONVECTIVE ELEMENTS. HRRR MODEL SHOWING INCREASING COVERAGE AND INTENSITY ALONG I-20 INTO THE HEAT OF THE AFTERNOON. VCTS FOR MANY CITES WITH AMENDMENTS TO COME AS THE THREAT UNFOLDS. SFC WINDS LIGHT SW AND SHIFTING TO N BEHIND OUTFLOW FOR KTXK/KELD AND SOON FOR KSHV. ALOFT...SHV VAD...LOW LEVEL VEERING FROM SW THIS AM TO NW THIS EARLY PM. FROPA WILL BE DURING THIS CYCLE WITH NE SFC WINDS. && .PREV DISCUSSION... /ISSUED 931 AM CDT THU SEP 11 2014/ UPDATE... HAVE UPDATED THE FORECAST TO MENTION HEAVY RAINFALL POSSIBLE IN THE AREAS ALONG AND NEAR THE I-30 CORRIDOR. WPC HAS OUTLOOKED THE AREA FOR HEAVY RAINFALL AND FLASH FLOODING LIKELY...NEW FORECAST IS ALREADY OUT... && .PRELIMINARY POINT TEMPS/POPS... SHV 93 73 88 65 83 / 40 40 50 30 20 MLU 95 72 88 65 86 / 40 30 50 40 20 DEQ 84 68 77 60 77 / 60 50 70 20 10 TXK 90 71 81 63 80 / 60 50 60 30 10 ELD 91 70 86 63 81 / 40 40 60 30 20 TYR 91 73 86 64 82 / 40 50 50 20 20 GGG 94 73 88 64 82 / 40 40 50 30 20 LFK 95 74 89 69 83 / 20 30 50 40 30 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...NONE. LA...NONE. OK...NONE. TX...NONE. && $$ 24
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
854 PM EDT FRI SEP 12 2014 .SYNOPSIS... COOL WEATHER PATTERN FOR MUCH OF THE FORECAST. SHOWERS WILL MOVE THROUGH SATURDAY MORNING. && .NEAR TERM /THROUGH SATURDAY/... HAVE ADJUSTED CLOUD COVER AND TEMPS FOR OVERNIGHT. DRIER AIR CONTINUES TO NOSE IN FROM THE EAST...SO CLOUDS WILL BE A LITTLE TRICKY EARLY IN THE FORECAST PERIOD. CLOUDS WILL BE ON THE INCREASE OVER THE CLEAR AREAS LATER TONIGHT AS THE NEXT SYSTEM SLOWLY MOVES IN FROM THE SOUTH AND WEST. PREVIOUS DISCUSSION FOLLOWS AND IS STILL LARGELY APPLICABLE...CLOUDY DAY ACROSS THE PBZ CWA. MDCRS PLOT FROM PIT CONTINUES TO SHOW A STOUT INVERSION JUST ABOVE H900. HOWEVER...CLOUDS ARE STARTING TO ERODE A BIT FROM THE EASTERN RIDGES...GARRETT AND TUCKER COUNTIES IN PARTICULAR ARE GETTING SOME SUN. WHILE THIS SLOW TREND SHOULD CONTINUE FOR A FEW HOURS WITH LBE AND DUJ BENEFITING A BIT...I AM DUBIOUS THAT MUCH CLOUD BREAKUP WILL OCCUR FROM PIT ON WEST. RAP SOUNDINGS CONCUR WITH THIS. IN ANY EVENT...AREAS THAT CLEAR WILL START TO SEE MID CLOUDS INCREASE THIS EVENING IN SW FLOW ALOFT AHEAD OF NEXT SYSTEM. MODELS ARE IN GOOD AGREEMENT ON THE SCENARIO. FAIRLY SHARP H500 SHORTWAVE WILL MOVE ACROSS THE GREAT LAKES TONIGHT AND INTO SOUTHERN QUEBEC BY 00Z SUNDAY. A WEAK SURFACE WAVE WILL FORM ALONG THE FRONT FROM YESTERDAY AND MOVES NORTHEAST THROUGH THE CAROLINAS TONIGHT. IN OUR CWA...INVERTED TROUGHING AT THE SURFACE WILL HELP TO PULL DEEPER MOISTURE BACK NORTHWARD...ESPECIALLY EAST OF THE OHIO RIVER. PWATS RISE TO AROUND 1.5 INCHES FOR A SHORT TIME SOUTH OF PIT LATE TONIGHT. POPS LITTLE CHANGED FROM PREVIOUS SHIFT...WITH LIKELY VALUES EAST OF HLG/PIT/FKL AND LESSER TO THE WEST. LOOKING FOR A QUARTER TO A HALF INCH OF RAIN AT MOST ALONG THE RIDGES. THUNDER NOT EXPECTED. SHORTWAVE TROUGH AXIS QUICKLY ROTATES THROUGH AFTER 12Z SATURDAY...WHICH WILL SHUNT THE DEEP MOISTURE EASTWARD BY MID-AFTERNOON. A FEW SHOWERS MAY LINGER IN LOW LEVEL NW FLOW...BUT EXPECTING ALL RAIN TO WRAP UP BY 00Z SUNDAY...WHEN A SURFACE HIGH BEGINS TO ARRIVE FROM THE WEST. BELOW SEASONAL TEMPERATURES WILL CONTINUE. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... BLDG HIGH PRES WL BRING DRY WEA THRU ERLY MON. THE HIGH WL SHIFT E MON AFTN...WITH INCRG CLDS AHD OF THE NXT APCHG SHRTWV. TEMPS WL CONT TO AVG BLO SEASONAL LVLS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... THE ADVNG SHRTWV IS EXPD TO SPAWN SHWRS MONDAY NGT AND EARLY TUES. SFC HIGH PRES...UNDR BROAD ERN CONUS TROFG...IS THEN FORECAST TO MAINTAIN DRY...BUT SEASONABLY COOL WEATHER FOR THE RMNDR OF THE LONG TERM PD. LONG TERM TEMPS WERE FORECAST USING HPC GUIDANCE... TWEAKED UPWARD VIA GFS MOS TRENDS. && .AVIATION /01Z SATURDAY THROUGH WEDNESDAY/... MVFR CIGS BLANKET ALL PORTS BUT MGW AND LBE. CLEARING LINE IS TRYING TO EDGE ITS WAY WESTWARD...SO AGC AND PIT MAY SEE SOME LESSENING OF CLOUD COVER BEFORE THE MVFR CIG DECK TO THE WEST BEGINS TO MOVE EASTWARD AHEAD OF NEXT SYSTEM. FORECAST WILL MIRROR THIS TREND OVERNIGHT. LIGHT SHOWERS WILL MOVE IN TOWARD DAWN...DON`T EXPECT MANY RESTRICTIONS AND RAINFALL MAY AVOID ZZV. SYSTEM QUICKLY MOVES EASTWARD SATURDAY MORNING...ALLOWING FOR IMPROVEMENT IN CONDITIONS FROM WEST TO EAST. WITH THE EXCEPTION OF NORTHERN PORTS...RETURN TO VFR CONDITIONS IS ANTICIPATED. OUTLOOK...THURSDAY NIGHT THROUGH TUESDAY... NEXT FRONTAL SYSTEM WITH POSSIBLE RESTRICTIONS ARRIVES MONDAY NIGHT INTO TUESDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
721 PM EDT FRI SEP 12 2014 .SYNOPSIS... COOL WEATHER WILL CARRY THROUGH MUCH OF THE NEXT SEVEN DAYS. LOW PRESSURE PASSING SATURDAY BRINGS THE CHANCE FOR SHOWERS...OUTSIDE EASTERN OHIO. AFTER A PERIOD OF DRY WEATHER THANKS TO HIGH PRESSURE...THE NEXT COLD FRONT IS PREDICTED TO CROSS TUESDAY INTO WEDNESDAY. && .NEAR TERM /THROUGH SATURDAY/... SKIES HAVE GENERALLY CLEARED IN THE RIDGES AND IN ALL POINTS TO THEIR EAST. AS LOW LEVEL FLOW AS TURNED A BIT MORE EASTERLY...A HINT OF DOWNSLOPE MAY ERODE THE EASTERN EDGE OF THE STRATUS SHIELD PRIOR TO MID-CLOUD INCREASING. SKY GRIDS WERE ADJUSTED ACCORDINGLY...HOWEVER ONLY THE EASTERN FRINGE OF THE FORECAST AREA IS LIKELY TO BENEFIT FROM ANY SCATTERING OUT/CLEARING...WHILE THE STRATUS SHOULD HOLD IN THE MAJORITY OF THE AREA UNTIL THE ARRIVAL OF A DEEPER CLOUD SHIELD. FRIES PREVIOUS DISCUSSION FOLLOWS AND IS STILL LARGELY APPLICABLE...CLOUDY DAY ACROSS THE PBZ CWA. MDCRS PLOT FROM PIT CONTINUES TO SHOW A STOUT INVERSION JUST ABOVE H900. HOWEVER...CLOUDS ARE STARTING TO ERODE A BIT FROM THE EASTERN RIDGES...GARRETT AND TUCKER COUNTIES IN PARTICULAR ARE GETTING SOME SUN. WHILE THIS SLOW TREND SHOULD CONTINUE FOR A FEW HOURS WITH LBE AND DUJ BENEFITING A BIT...I AM DUBIOUS THAT MUCH CLOUD BREAKUP WILL OCCUR FROM PIT ON WEST. RAP SOUNDINGS CONCUR WITH THIS. IN ANY EVENT...AREAS THAT CLEAR WILL START TO SEE MID CLOUDS INCREASE THIS EVENING IN SW FLOW ALOFT AHEAD OF NEXT SYSTEM. MODELS ARE IN GOOD AGREEMENT ON THE SCENARIO. FAIRLY SHARP H500 SHORTWAVE WILL MOVE ACROSS THE GREAT LAKES TONIGHT AND INTO SOUTHERN QUEBEC BY 00Z SUNDAY. A WEAK SURFACE WAVE WILL FORM ALONG THE FRONT FROM YESTERDAY AND MOVES NORTHEAST THROUGH THE CAROLINAS TONIGHT. IN OUR CWA...INVERTED TROUGHING AT THE SURFACE WILL HELP TO PULL DEEPER MOISTURE BACK NORTHWARD...ESPECIALLY EAST OF THE OHIO RIVER. PWATS RISE TO AROUND 1.5 INCHES FOR A SHORT TIME SOUTH OF PIT LATE TONIGHT. POPS LITTLE CHANGED FROM PREVIOUS SHIFT...WITH LIKELY VALUES EAST OF HLG/PIT/FKL AND LESSER TO THE WEST. LOOKING FOR A QUARTER TO A HALF INCH OF RAIN AT MOST ALONG THE RIDGES. THUNDER NOT EXPECTED. SHORTWAVE TROUGH AXIS QUICKLY ROTATES THROUGH AFTER 12Z SATURDAY...WHICH WILL SHUNT THE DEEP MOISTURE EASTWARD BY MID-AFTERNOON. A FEW SHOWERS MAY LINGER IN LOW LEVEL NW FLOW...BUT EXPECTING ALL RAIN TO WRAP UP BY 00Z SUNDAY...WHEN A SURFACE HIGH BEGINS TO ARRIVE FROM THE WEST. BELOW SEASONAL TEMPERATURES WILL CONTINUE. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... BLDG HIGH PRES WL BRING DRY WEA THRU ERLY MON. THE HIGH WL SHIFT E MON AFTN...WITH INCRG CLDS AHD OF THE NXT APCHG SHRTWV. TEMPS WL CONT TO AVG BLO SEASONAL LVLS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... THE ADVNG SHRTWV IS EXPD TO SPAWN SHWRS MONDAY NGT AND EARLY TUES. SFC HIGH PRES...UNDR BROAD ERN CONUS TROFG...IS THEN FORECAST TO MAINTAIN DRY...BUT SEASONABLY COOL WEATHER FOR THE RMNDR OF THE LONG TERM PD. LONG TERM TEMPS WERE FORECAST USING HPC GUIDANCE... TWEAKED UPWARD VIA GFS MOS TRENDS. && .AVIATION /23Z FRIDAY THROUGH WEDNESDAY/... MVFR CIGS BLANKET ALL PORTS BUT MGW AND LBE. CLEARING LINE IS TRYING TO EDGE ITS WAY WESTWARD...SO AGC AND PIT MAY SEE SOME LESSENING OF CLOUD COVER BEFORE THE MVFR CIG DECK TO THE WEST BEGINS TO MOVE EASTWARD AHEAD OF NEXT SYSTEM. FORECAST WILL MIRROR THIS TREND OVERNIGHT. LIGHT SHOWERS WILL MOVE IN TOWARD DAWN...DON`T EXPECT MANY RESTRICTIONS AND RAINFALL MAY AVOID ZZV. SYSTEM QUICKLY MOVES EASTWARD SATURDAY MORNING...ALLOWING FOR IMPROVEMENT IN CONDITIONS FROM WEST TO EAST. WITH THE EXCEPTION OF NORTHERN PORTS...RETURN TO VFR CONDITIONS IS ANTICIPATED. OUTLOOK...THURSDAY NIGHT THROUGH TUESDAY... NEXT FRONTAL SYSTEM WITH POSSIBLE RESTRICTIONS ARRIVES MONDAY NIGHT INTO TUESDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
359 PM EDT THU SEP 11 2014 .SYNOPSIS... COLD FRONT WILL CROSS THE REGION THIS EVENING AND INTO THE OVERNIGHT. THE FRONT WILL STALL OVER NORTH CAROLINA THROUGH THE WEEKEND. FRONTAL BOUNDARY WILL REMAIN ALONG THE SOUTHEAST COAST INTO EARLY NEXT WEEK AS HIGH PRESSURE BUILDS TO THE NORTH. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... LATEST RADAR MOSAIC DEPICTS A NARROW BAND OF SHOWERS/THUNDERSTORMS OVER THE HIGHER TERRAIN OF WRN VA. COLD FRONT LOCATED NOT FAR BEHIND OVER THE CNTRL APPALACHIANS. ISOLATED SHOWERS HAVE DEVELOPED JUST WEST OF THE LOCAL AREA...BUT QUICKLY DISSIPATED AS THEY PROPAGATED EWD THANKS TO SUBSIDENCE ALOFT. EXPECT THIS TREND TO CONTINUE UNTIL THE COLD FRONT REACHES THE LOCAL AREA LATE THIS AFTERNOON-EARLY THIS EVENING. WEAK UPPER WAVE VISIBLE ON WATER VAPOR WILL PUSH INTO THE REGION THIS EVENING AS THE COLD FRONT SLOWLY CROSSES THE LOCAL AREA. PRECIP CHANCES THIS EVENING WILL BE TIED TO THE WEAKENING FRONT/CONVERGENCE ZONE. SHORTWAVE WILL HELP SUPPORT SOME MODEST UVM...BUT WITH THE BEST DYNAMICS/FLOW REMAINING WELL NORTH...UPPER LEVEL FORCING WILL BE RATHER UNIMPRESSIVE. HI-RES GUIDANCE CONTINUES TO INDICATE SCT SHOWERS/THUNDERSTORMS ALONG/IN ADVANCE OF THE FRONT WITH THE BEST COVERAGE OVER THE N AND NE. SOME LOCATIONS IN THE SW COULD EVEN REMAIN DRY. UPSTREAM PWATS AROUND 2 INCHES WILL SPREAD INTO THE REGION IN WLY FLOW...WITH MOISTURE EXTENDING UP TO 300MB. UNFAVORABLE OVERNIGHT FRONTAL TIMING AND WEAK SHEAR WILL ONLY RESULT IN SLIGHT CHANCE-CHANCE THUNDER. POTENTIAL EXISTS OVER THE PIEDMONT FOR GUSTY WINDS AS TIMING AND INSTABILITY IS BETTER AND BUFR SOUNDINGS INDICATED DRY LOW LEVELS. LOCALLY HEAVY RAINFALL IS ALSO POSSIBLE DUE TO HIGH PWATS AND WEAK FLOW. FRONTAL TIMING AND CLOUDS WILL RESULT IN MILD OVERNIGHT TEMPS...GENERALLY IN THE MID-UPPER 60S. COOLER IN THE NW IF SKIES CAN CLEAR BEHIND THE FRONT. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/... UNSETTLED/WET WEATHER PATTERN EXPECTED THROUGH THE WEEKEND AS TEMPS REMAIN BELOW NORMAL. COLD FRONT PUSHES THRU THE AREA THRU FRI MORNING...STALLING ACROSS NC AS FLOW ALOFT REMAINS SWLY. A POTENT UPPER SHORTWAVE OVER THE UPPER MIDWEST WILL EJECT QUICKLY EWD AS A STRONG SPEED MAX ROUNDS THE BASE OF THE TROUGH. SUBTROPICAL HIGH GETS SHOVED SWD OVER THE GULF STATES/NRN GULF...BUT VERY LITTLE CHANGE IN MID LEVEL HEIGHTS OVER THE LOCAL AREAL. SFC HIGH PRESSURE BUILDS OVER SE CANADA/NE US WITH A RIDGE AXIS EXTENDING SWD INTO THE LOCAL AREA. STILL SOME UNCERTAINTY AS TO WHERE THE FRONT WILL STALL...BUT ATTM IT APPEARS IT WILL BE JUST SOUTH OF THE LOCAL AREA. BEST CHANCES FOR MEASURABLE RAIN WILL BE TIED TO THE WEAK FRONTAL BOUNDARY AND HIGH PWAT AXIS. HOWEVER...MDLS DIFFER ON THE AMOUNT OF MOISTURE OVER THE LOCAL AREA...WHICH COMBINED WITH WEAK WAVES IN SWLY FLOW MAY BE ENOUGH FOR SHOWERS FRI. WILL KEEP BETTER POPS CLOSE TO THE FRONT...BUT WILL MAINTAIN LOW END CHANCE POPS NWD INTO CNTRL VA. HYBRID WEDGE SETUP WILL KEEP SKIES CLOUDY AS WINDS WILL BE FROM THE N-NE. CLOUDS/POSSIBLE PRECIP WILL PREVENT TEMPS FROM REACHING THEIR FULL POTENTIAL WITH HIGHS GENERALLY IN THE MID 70S. SHORTWAVE PROPAGATES EWD OVER THE GREAT LAKES INTO SE CANADA SAT. A WAVE OF LOW PRESSURE IS PROGGED TO DEVELOP ALONG THE FRONT OVER THE TN VALLEY WITH ANOTHER AREA OF LOW PRESSURE DEVELOPING OFF THE NC COAST. THE INLAND LOW WILL BEGIN TO LIFT NEWD IN AMPLIFYING FLOW...LIFTING THE FRONT NWD. TWO DISTINCT AREAS OF PRECIP EXPECTED TO DEVELOP FRI NIGHT-SAT MORNING...WITH THE FIRST LIFTING OVER THE CNTRL APPALACHIANS AND THE OTHER REMAINING OVER ERN NC AND OFFSHORE. BUT AS THE LOW QUICKLY LIFTS NWD INTO NEW ENGLAND...OVERRUNNING MOISTURE/PRECIP OVERSPREAD MUCH OF THE LOCAL AREA FROM THE SOUTH AND WEST. HAVE INCREASED POPS TO LIKELY AS BETTER AGREEMENT IN THE MODELS LENDS TO HIGHER CONFIDENCE. PWATS RETURN TO AROUND 2+ INCHES...AND MOISTURE EXTENDS WELL ABOVE 0C...SO LOCALLY HEAVY RAINFALL IS POSSIBLE. SHORTWAVE PUSHES OFF THE NE COAST SAT NIGHT INTO SUN MORNING AS THE COASTAL LOW LIFTS NEWD AWAY FROM THE COAST. HOWEVER...FLOW REMAINS SWLY OVER THE LOCAL AREA WITH THE BOUNDARY REMAINING ALONG THE COAST. HIGH PRESSURE WILL ALSO BUILD OVER NEW ENGLAND IN WAKE OF LOW PRESSURE...REINFORCING THE HYBRID CAD OVER THE LOCAL AREA. NLY FLOW WILL AGAIN RESULT IN MOSTLY CLOUDY-CLOUDY SKIES. INLAND BUFR SOUNDINGS INDICATE SOME CLEARING OVER THE PIEDMONT. BEST RAINFALL CHANCES TRANSITION TO ERN VA SAT NIGHT INTO SUN WITH THE BEST CHANCES FOR PRECIP TRANSFERRING TO SE VA/NE NC SUN. TRENDED QPF TOWARD ENSEMBLE MEAN GUIDANCE...WITH QPF AMOUNTS THIS WEEKEND RANGING FROM AROUND ONE QUARTER INCH NE TO AN INCH SOUTH. HOWEVER...THERE ARE SOME OUTLIERS INDICATING THAT MORE RAINFALL MAY FALL. BASED ON PWATS OF +2 STD DEV AND WEAK FLOW...LOCALLY HEAVY RAINFALL IS EXPECTED WITH SOME AREAS RECEIVING UPWARDS OF 2+ INCHES. HIGHS AGAIN SUN IN THE LOW-MID 70S. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... DESPITE THE TIME OF THE YEAR...WILL LEAN TOWARD THE WETTER ECMWF GIVEN THE FORECASTED UPR LVL PATTERN NEXT WEEK. FRONTAL BOUNDARY REMAINS SOUTH OF THE REGION TO START OFF THE PERIOD WITH SEVERAL AREAS OF LOW PRESSURE MOVING NORTH ALONG IT MONDAY AND TUESDAY BASICALLY KEEPING CLOUDS AND PERIODIC CHCS FOR RAIN. FRONTAL BNDRY MAY ACTUALLY SNAKE BACK NORTH AS A WARM FRONT TUESDAY SO WENT AHEAD AND ADDED THUNDER ACROSS SERN HALF OF FA THEN. CLOUDS / PCPN KEEPS TMPS BLO NORMAL WITH HIGHS BOTH DAYS IN THE 70S. LOWS U50S-U60S. TRAILING COLD FRONT PUSHES OFFSHORE TUES NIGHT AND ERLY WED AS THE 1020MB CANADIAN HIGH PRS BUILDS EAST. GUID WANTS TO STALL THIS BNDRY IVOF THE GULF STREAM ONCE AGAIN KEEPING ADDNTL CLOUDINESS AND SCT SHWRS ALONG THE MID ATLNTC COASTAL SECTIONS WED INTO THU. COOLER WITH HIGH WED / THU 70-75. LOWS IN THE 50S XCPT 60S COASTAL AREAS. && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... VFR CONDITIONS PREVAIL AHEAD OF A COLD FRONT. THE FRONT WILL MOVE ACROSS THE AREA THIS EVENING. ACCOMPANYING THE FRONT WILL BE SCATTERED SHOWERS AND TSTMS. SEVERAL MODELS WEAKEN THESE STORMS AS THE CROSS THE AREA TONIGHT. THE HRRR TRIES TO BRING SOME THROUGH AFTER 00Z TO ABOUT 03Z. WOULD EXPECT AT LEAST SOME SHOWERS THAT TIME FRAME AND POSSIBLY A TSTM. THE HEAVIEST SHOWERS COULD BRIEFLY BRING MVFR CIGS OR VSBY. AFTER THE FRONT PASSES WINDS WILL SHIFT TO THE NORTHEAST. WINDS ALOFT WILL REMAIN SOUTHWEST AND CAUSE THE FRONT TO STALL IN NORTHEAST NORTH CAROLINA. THIS WILL CAUSE CLOUDS TO LINGER ACROSS THE AREA LATE TONIGHT AND THROUGH FRIDAY. THERE IS A GOOD CHANCE FOR MVFR CIGS FROM PHF SOUTHEAST. COULD EVEN BE SOME BRIEF IFR CIGS ON FRIDAY MORNING. THERE WILL ALSO BE THE CHANCE OF SHOWERS AGAIN ON FRIDAY. OUTLOOK...THE FRONT REMAINS STATIONARY IN NE NC WITH WEAK WAVES OF LOW PRESSURE MOVING ALONG IT INTO THE WEEKEND. THIS WILL CAUSE PERIODS OF PCPN AND POSSIBLE MVFR AND PATCHY IFR SATURDAY THROUGH SUNDAY. && .MARINE... MODELS CONTINUE TO SHOW A SEVERAL HOUR PERIOD OF MINIMAL SCA WINDS BEHIND A COLD FRONT LATE TONIGHT AND FRI. TWEEKED TIMING OF SCA`S FOR THE BAY A BIT AND ALSO ADDED THE LOWER JAMES RIVER TO THE MIX FRI MORNING. WENT AHEAD WITH A MINIMAL SCA FOR NRN CSTL WTRS FRI MORNING AS WELL. DATA SUGGESTS GUSTS TO 25 KTS PSBL N OF PARRAMORE ISLAND FOR A FEW HRS. SEAS AVGG 3-4 FT BUT CAN`T RULE OUT SOME 5 FOOTERS OUT NEAR 20 NM AT TIMES. HIGH PRES MOVES INTO NEW ENG BY SAT...BRINGING CONTD ONSHORE (NE) WNDS AHEAD OF NEXT LOW PRES SYS AND ITS ASSOCIATED CDFNT. THAT SYS CROSSES THE WTRS SAT NIGHT. MODELS NOT AS BULLISH WITH THE SURGE BEHIND THIS BNDRY...BUT WILL CONTINUE TO INDICATE ANTHR CAA SURGE SUN MORNING GIVEN THE MODELS TEND TO UNDERFCST THESE EVENTS. ONSHORE FLOW CONTINUES INTO EARLY NEXT WEEK BUT SPEEDS XPCTD TO REMAIN BLO 20 KTS AS A COMPLEX SYSTEM OF LOW PRESSURE SYSTMS AFFECT THE MID ATLNTC REGION. && .TIDES/COASTAL FLOODING... GIVEN A FORECAST OF LEVELS RIGHT ARND MINOR FLOODING THRESHOLDS FOR THIS AFTRNS HIGH TIDE...WENT AHEAD AND ISSUED ANTHR CSTL FLOOD ADVSRY FOR THE CHES BAY SIDE OF THE LWR MD ERN SHORE BTWN 18Z-00Z. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR MDZ025. COASTAL FLOOD ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MDZ021>023. NC...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR NCZ102. VA...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR VAZ098>100. MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 4 PM EDT FRIDAY FOR ANZ632- 634. SMALL CRAFT ADVISORY FROM 6 AM TO NOON EDT FRIDAY FOR ANZ630- 631. SMALL CRAFT ADVISORY FROM 6 AM TO 1 PM EDT FRIDAY FOR ANZ638. SMALL CRAFT ADVISORY FROM 6 AM TO 2 PM EDT FRIDAY FOR ANZ650- 652. && $$ SYNOPSIS...SAM NEAR TERM...SAM SHORT TERM...SAM LONG TERM...MPR AVIATION...LSA/JAB MARINE...MPR TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
134 PM EDT THU SEP 11 2014 .SYNOPSIS... A COLD FRONT OVER THE OHIO VALLEY WILL APPROACH THE MID ATLANTIC STATES AND MOVE THROUGH THE AREA TONIGHT AND SETTLE OVER NORTH CAROLINA FRIDAY. A LOW PRESSURE SYSTEM WILL AFFECT THE REGION SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... HIGH PRESSURE HAS PUSHED OFFSHORE THIS MORNING IN ADVANCE OF A COLD FRONT APPROACHING FROM THE WEST. GRADIENT BTWN THESE SFC FEATURES HAS PRODUCED SW WINDS OF 10 TO 15 MPH WITH A FEW GUSTS OF 25 MPH. MORNING STRATUS HAS ERODED WITH ONLY SOME PASSING HIGH CLOUDS RESULTING IN PARTLY SUNNY SKIES. TEMPS HAVE ALREADY WARMED INTO THE UPPER 70S TO LOW 80S THANKS TO SW WINDS AND INCREASING THICKNESSES. FOR TODAY...WATER VAPOR AND MORNING RAOB PLOTS INDICATE SHORTWAVE ENERGY OVER THE LWR MO VALLEY THAT WILL TRACK EWD ALONG THE KY/TN VALLEYS THRU THE DAY. COLD FRONT WILL REACH THE CNTRL APPALACHIANS EARLY THIS EVENING. IN ADVANCE OF THE FRONT...STRONG SFC HEATING AND SW WINDS (GUSTS TO 20 MPH) WILL PUSH TEMPS INTO THE LOW 90S (+1 STD DEV) MOST LOCATIONS. LOW-MID 80S ALONG THE COAST. HIGH PRESSURE ALOFT WILL NUDGE INTO THE REGION FROM THE SW TODAY...HELPING PROVIDE SUBSIDENCE OVER THE REGION. LACK OF APPRECIABLE FORCING/TRIGGER WILL ALSO HELP KEEP THINGS DRY...REGARDLESS OF INCREASING MOISTURE/INSTABILITY AND POTENTIAL HEATING/DIFFERENTIAL BOUNDARIES. MAINLY FAIR WEATHER CU TODAY UNDER THE INVERSION...WITH MID-HIGH CLOUDS INCREASING FROM THE WEST LATE TODAY. PRECIP CHANCES WILL BE TIED TO THE WEAKENING FRONT/CONVERGENCE ZONE. AFOREMENTIONED SHORTWAVE WILL LIKELY HELP SUPPLY SOME MODEST UVM...BUT WITH THE BEST DYNAMICS/FLOW REMAINING WELL NORTH...UPPER LEVEL FORCING WILL BE RATHER UNIMPRESSIVE. EVEN ONGOING PRECIP OVER THE CNTRL APPALACHIANS WILL QUICKLY OUTRUN THE BETTER UPPER LEVEL SUPPORT...LIKELY DISSIPATING AS IT REACHES THE PIEDMONT. PRECIP CHANCES INCREASE LATE TODAY INTO THIS EVENING ACROSS THE PIEDMONT. HI-RES GUIDANCE CONTINUES TO INDICATE SCT SHOWERS/THUNDERSTORMS ALONG THE LINE WITH THE BEST COVERAGE OVER THE N AND NE. SOME LOCATIONS IN THE SW COULD REMAIN DRY. UPSTREAM PWATS AROUND 2 INCHES WILL SPREAD INTO THE REGION IN WLY FLOW...WITH MOISTURE EXTENDING UP TO 300MB. UNFAVORABLE OVERNIGHT FRONTAL TIMING AND WEAK SHEAR WILL ONLY RESULT IN SLIGHT CHANCE THUNDER. POTENTIAL EXISTS OVER THE PIEDMONT FOR GUSTY WINDS AS TIMING AND INSTABILITY IS BETTER AND BUFR SOUNDINGS INDICATED DRY LOW LEVELS. LOCALLY HEAVY RAINFALL IS ALSO POSSIBLE DUE TO HIGH PWATS AND WEAK FLOW. FRONTAL TIMING AND CLOUDS WILL RESULT IN MILD OVERNIGHT TEMPS...GENERALLY IN THE MID-UPPER 60S. COOLER IN THE NW IF SKIES CAN CLEAR BEHIND THE FRONT. && .SHORT TERM /FRIDAY THROUGH SATURDAY/... FRIDAY WILL SEE SIGNIFICANTLY COOLER TEMPERATURES DUE TO CLOUD COVER AND A COOLER AIR MASS. PCPN WILL BE MAINLY OVER SE PORTIONS CLOSE TO THE FRONT WITH POPS LOWERING THROUGH THE DAY FROM NORTH TO SOUTH. FUTURE ISSUANCES MAY BE ABLE TO HAVE ADDITIONAL LOWERING OF THE POPS NORTHERN PORTIONS. LOWERED TEMPERATURES FRIDAY WITH GENERALLY LOW TO MID 70S EXCEPT UPR 70S TO NEAR 80 IN NORTH CAROLINA COUNTIES. CLOUD COVER WILL RESULT IN LOW TEMPERATURES FROM THE MID 60S TO AROUND 70 SATURDAY MORNING. AN UPPER LEVEL SHORT WAVE MOVES ACROSS THE MIDWEST AND DEVELOPS A SURFACE LOW TO OUR WEST. THIS WILL BRING AN INCREASE IN MOISTURE AND PCPN DURING THE DAY SATURDAY. BASICALLY HAVE 50 PERCENT POPS ACROSS THE AREA AS THE DETAILS ARE NOT CLEAR AT THIS POINT. FUTURE ISSUANCES WILL PROBABLY HAVE LIKELY POPS IN PORTIONS OF THE CWA. CLOUD COVER AND PCPN WILL HOLD TEMPERATURES DOWN AND HAVE HIGHS JUST A FEW DEGREES HIGHER THAN FRIDAY...GENERALLY MID TO UPR 70S WITH 80 DEGREE READINGS IN NORTH CAROLINA. MINOR CHANGES WERE MADE TO THE FORECAST FOR SATURDAY NIGHT AND SUNDAY BUT GENERALLY DRYING MOVES IN FROM THE NW FOLLOWING THE PASSAGE OF THE SHORT WAVE. ANOTHER DAY OF BELOW NORMAL TEMPERATURES IS EXPECTED ON SUNDAY. SEE BELOW FOR MORE DETAILS. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... UPR LEVEL TROF ACROSS THE ERN US RESULTS IN A COOLER THAN NORMAL PATTERN THROUGH THE MEDIUM RANGE PERIOD. MODELS SEEM TO AGREE THAT THE FA WILL BE NORTH OF THE STALLED FRONTAL BOUNDARY (IVOF THE GULF STREAM) EARLY NEXT WEEK. THE FORECAST CHALLENGE WILL BE TIMING OF SEVERAL WAVES OF ENERGY PROGGED TO MOVE NE ALONG THIS BOUNDARY AS CANADIAN HIGH PRESSURE (1025 MB) TRACKS EAST WHILE REMAINING NORTH OF THE AREA. FOLLOWED THE ECMWF WRT SYNOPTIC FEATURES WHICH FEATURES A SCNDRY BNDRY PASSAGE SAT NIGHT / SUNDAY. KEPT CHC POPS (SHWRS) IN ATTM WITH THE HIGHEST POPS ACROSS SRN HALF OF FA...ESPECIALLY SUNDAY. MAY ACTUALLY DRY ACROSS NRN COUNTIES WITH SOME AFTRN SUNSHINE GIVEN STRENGTH OF THE HIGH PRESSURE BUILDING IN FROM THE NW. LOWS SAT & SUN NIGHTS 55-60 NORTH...M-U60S SOUTH. HIGHS SUN L-M70S. DATA SUGGESTS BOUNDARY BEGINS TO DRIFT BACK NORTH AS A WARM FRONT MON AND TUES...BUT CONFIDENCE ON JUST HOW FAR NORTH IT GETS IS PROBLEMATIC ATTM. KEPT CHC POPS (SHWRS...KEEPING THUNDER OUT OF FCST THIS FAR OUT) WITH HIGHEST POPS SOUTH ONCE AGAIN. HIGHS MON L-M70S. LOWS MON NIGHT U50S-U60S. WARMING A BIT TUESDAY WITH HIGHS 75-80. DRYING OUT WED WITH HIGHS M-U70S. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... VFR CONDITIONS PREVAIL AHEAD OF A COLD FRONT. THE FRONT WILL MOVE ACROSS THE AREA THIS EVENING. ACCOMPANYING THE FRONT WILL BE SCATTERED SHOWERS AND TSTMS. SEVERAL MODELS WEAKEN THESE STORMS AS THE CROSS THE AREA TONIGHT. THE HRRR TRIES TO BRING SOME THROUGH AFTER 00Z TO ABOUT 03Z. WOULD EXPECT AT LEAST SOME SHOWERS THAT TIME FRAME AND POSSIBLY A TSTM. THE HEAVIEST SHOWERS COULD BRIEFLY BRING MVFR CIGS OR VSBY. AFTER THE FRONT PASSES WINDS WILL SHIFT TO THE NORTHEAST. WINDS ALOFT WILL REMAIN SOUTHWEST AND CAUSE THE FRONT TO STALL IN NORTHEAST NORTH CAROLINA. THIS WILL CAUSE CLOUDS TO LINGER ACROSS THE AREA LATE TONIGHT AND THROUGH FRIDAY. THERE IS A GOOD CHANCE FOR MVFR CIGS FROM PHF SOUTHEAST. COULD EVEN BE SOME BRIEF IFR CIGS ON FRIDAY MORNING. THERE WILL ALSO BE THE CHANCE OF SHOWERS AGAIN ON FRIDAY. OUTLOOK...THE FRONT REMAINS STATIONARY IN NE NC WITH WEAK WAVES OF LOW PRESSURE MOVING ALONG IT INTO THE WEEKEND. THIS WILL CAUSE PERIODS OF PCPN AND POSSIBLE MVFR AND PATCHY IFR SATURDAY THROUGH SUNDAY. && .MARINE... SSW WNDS AHEAD OF APPROACHING CDFNT FM THE W THROUGH TDA. A BIT OF A NOCTURNAL SURGE (TO ABT 15 KT) INVOF CNTRL BAY INTO EARLY THIS MRNG. OTRW...CONDS RMN BLO SCA INTO TNGT. CDFNT CROSSES THE WTRS AFT MIDNIGHT THROUGH MID MRNG FRI. XPCG A POST FNTL SURGE IN SPEEDS FM THE N (TO LO END SCA ON THE BAY)...THERE MAY BE A SHORT PD OF SCAS ON THE (NRN) OCN WATERS IN THE EARLY/MID MRNG AS WELL. IT IS TIME OF YEAR FOR THESE TYPES OF SURGES TO BE A BIT MORE ROBUST THAN MDLS FCST (COOLER/DRIER AIR SPREADING OVR WARMER WTRS). THE INCRS IN SPDS DIMINISHES FM N TO S OVR THE WTRS IN THE AFTN/EVE HRS. SFC HI PRES MOVES INTO NEW ENG BY SAT...BRINGING CONTD ONSHORE WNDS AHEAD OF NEXT APPROACHES LO PRES SYS AND ITS ASSOCIATED CDFNT. THAT SYS CROSSES THE WTRS SAT EVE...W/ PTNTLLY AN EVEN STRONGER NLY SURGE IN ITS WAKE INTO SUN. && .TIDES/COASTAL FLOODING... GIVEN A FORECAST OF LEVELS RIGHT ARND MINOR FLOODING THRESHOLDS FOR THIS AFTRNS HIGH TIDE...WENT AHEAD AND ISSUED ANTHR CSTL FLOOD ADVSRY FOR THE CHES BAY SIDE OF THE LWR MD ERN SHORE BTWN 18Z-00Z. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR MDZ025. COASTAL FLOOD ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MDZ021>023. NC...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR NCZ102. VA...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR VAZ098>100. MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 3 PM EDT FRIDAY FOR ANZ632- 634. SMALL CRAFT ADVISORY FROM 6 AM TO NOON EDT FRIDAY FOR ANZ630- 631. && $$ SYNOPSIS...LSA NEAR TERM...SAM SHORT TERM...LSA LONG TERM...MPR AVIATION...LSA/JAB MARINE...ALB TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1055 PM CDT Fri Sep 12 2014 .UPDATE: Issued at 1027 PM CDT Fri Sep 12 2014 Issued at 620 PM CDT Fri Sep 12 2014 cloud cover continues to slowly recede southeastward across north- central Missouri. Light to moderate drizzle still continues over much of central Missouri into southwest and central Illinois. Light to moderate drizzle will continue over parts of central and much of east-central - southwest illinois through early Saturday morning. Cloud cover will slowly recede southward with time. But will still continue to linger beyond 0900 UTC. Surface winds will be dimishing to 5 kts after 0600 UTC. temperatures will drop intot he upper 30s over far northeast Missouri tonight under clear skies. Should be a fine day on Saturday with partly cloudy skies and mild tempatures over the region as surface high pressure builds over the area. Could reach record lows for far northeast Missouri and again on Sunday morning for northeast through central Missouri. Przybylinski && .SHORT TERM: (Through Tonight) Issued at 236 PM CDT Fri Sep 12 2014 Cloud cover continues to cover the area this afternoon as stratus is trapped under a low level inversion and mid-high level clouds are streaming in ahead of a mid level trough. There has been some light rain associated with the mid-level trough moving across northern Missouri early this afternoon, but it`s coverage has been limited. Latest runs of the RAP and HRRR still show some redevelopment of some light rain over western Missouri this afternoon and this evening ahead of the upper trough that will move across the CWA this evening. Then expect clearing of the clouds from north to south after 06Z as the upper trough moves to the east allowing subsidence to set in. Drier air will move into the low levels as the inversion weakens which should allow the low level clouds to move out. Temperatures should fall close to agreeable MOS guidance for lows once skies begin to clear with the light northeasterly winds. Britt .LONG TERM: (Saturday through Next Friday) Issued at 236 PM CDT Fri Sep 12 2014 (Saturday through Monday) Overall, mdls are in good agreement thru this period. Period begins with a large sfc ridge settling across the region. This ridge will keep temps around 15 degrees below seasonal average despite ample insolation. As the ridge retreats, the approaching trof and sfc fnt will bring another chance for precip to the region late in the period. Some minor differences in timing are apparent among the mdl guidance. Will keep PoPs lower except where mdls are in agreement. (Tuesday through Friday) Not much change from the prev forecast. Mdls remain in good agreement overall thru the period with respect to mass fields anyway. Sfc ridge builds into the region on Tues with precip coming to an end Mon night. Cool temps will prevail thru mid week, tho not as cool as this weekend. Mdls differ regarding precip chances for late Wed into Thurs. The ECMWF is more robust with nocturnal convection developing along a stationary fnt across the region. The GFS would suggest height rising with the sfc ridge still holding on into the area. Have kept PoPs low given the uncertainty forecasting mesoscale features on day 7. As for temps, have trended twd the warmer guidance thru the period given heights over the region. Tilly && .AVIATION: (For the 00z TAFs through 00z Saturday Evening) Issued at 534 PM CDT Fri Sep 12 2014 An extensive area of MVFR stratus/stratocumulus was in place across the region at TAF issuance. Although drier air will be working into the region overnight, there is still a lot of moisture trapped below an inversion. This suggests that clouds will be slow to clear even with the drier air. On the other hand, recent satellite imagery has shown that upstream stratocu was breaking up over IA/NE, and it is possible that cigs may clear earlier than expected. Ceilings could fall to IFR at times overnight until the drier air arrives. Intermittent light drizzle or light rain may also occur over the next several hours. Initially northerly winds will back slightly overnight then veer tomorrow. Specifics for KSTL: It is likely that MVFR ceilings will persist overnight. Ceilings should rise by tomorrow morning at the latest due to diurnal mixing and drier low-level air. Initially northerly winds will back slightly overnight then veer tomorrow and become easterly towards the end of the valid TAF period. Kanofsky && .CLIMATE: Issued at 236 PM CDT Fri Sep 12 2014 Record Lows This Weekend: STL COU UIN 13 43(1975) 33(1902) 33(1902) 14 46(1996) 40(1892) 38(1996) && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
625 PM CDT Fri Sep 12 2014 .UPDATE: Issued at 620 PM CDT Fri Sep 12 2014 Updated forecasts for much of northern and central Missouri based on the timing of precipitation. Frontogenetical band of rainshowers continues to slowly slide southeast as precipitation elements move to the east-northeast at 30 to 35 mph. Did not change much in the way of temperatures but will look closer on temperatures in the next update. Back to fall like weather again. Przybylinski && .SHORT TERM: (Through Tonight) Issued at 236 PM CDT Fri Sep 12 2014 Cloud cover continues to cover the area this afternoon as stratus is trapped under a low level inversion and mid-high level clouds are streaming in ahead of a mid level trough. There has been some light rain associated with the mid-level trough moving across northern Missouri early this afternoon, but it`s coverage has been limited. Latest runs of the RAP and HRRR still show some redevelopment of some light rain over western Missouri this afternoon and this evening ahead of the upper trough that will move across the CWA this evening. Then expect clearing of the clouds from north to south after 06Z as the upper trough moves to the east allowing subsidence to set in. Drier air will move into the low levels as the inversion weakens which should allow the low level clouds to move out. Temperatures should fall close to agreeable MOS guidance for lows once skies begin to clear with the light northeasterly winds. Britt .LONG TERM: (Saturday through Next Friday) Issued at 236 PM CDT Fri Sep 12 2014 (Saturday through Monday) Overall, mdls are in good agreement thru this period. Period begins with a large sfc ridge settling across the region. This ridge will keep temps around 15 degrees below seasonal average despite ample insolation. As the ridge retreats, the approaching trof and sfc fnt will bring another chance for precip to the region late in the period. Some minor differences in timing are apparent among the mdl guidance. Will keep PoPs lower except where mdls are in agreement. (Tuesday through Friday) Not much change from the prev forecast. Mdls remain in good agreement overall thru the period with respect to mass fields anyway. Sfc ridge builds into the region on Tues with precip coming to an end Mon night. Cool temps will prevail thru mid week, tho not as cool as this weekend. Mdls differ regarding precip chances for late Wed into Thurs. The ECMWF is more robust with nocturnal convection developing along a stationary fnt across the region. The GFS would suggest height rising with the sfc ridge still holding on into the area. Have kept PoPs low given the uncertainty forecasting mesoscale features on day 7. As for temps, have trended twd the warmer guidance thru the period given heights over the region. Tilly && .AVIATION: (For the 00z TAFs through 00z Saturday Evening) Issued at 534 PM CDT Fri Sep 12 2014 An extensive area of MVFR stratus/stratocumulus was in place across the region at TAF issuance. Although drier air will be working into the region overnight, there is still a lot of moisture trapped below an inversion. This suggests that clouds will be slow to clear even with the drier air. On the other hand, recent satellite imagery has shown that upstream stratocu was breaking up over IA/NE, and it is possible that cigs may clear earlier than expected. Ceilings could fall to IFR at times overnight until the drier air arrives. Intermittent light drizzle or light rain may also occur over the next several hours. Initially northerly winds will back slightly overnight then veer tomorrow. Specifics for KSTL: It is likely that MVFR ceilings will persist overnight. Ceilings should rise by tomorrow morning at the latest due to diurnal mixing and drier low-level air. Initially northerly winds will back slightly overnight then veer tomorrow and become easterly towards the end of the valid TAF period. Kanofsky && .CLIMATE: Issued at 236 PM CDT Fri Sep 12 2014 Record Lows This Weekend: STL COU UIN 13 43(1975) 33(1902) 33(1902) 14 46(1996) 40(1892) 38(1996) && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
255 PM CDT Thu Sep 11 2014 .SHORT TERM: (Through Late Tonight) Issued at 252 PM CDT Thu Sep 11 2014 Clouds have not cleared out this afternoon even though high pressure has begun to build into the low levels. This is because of persistent low level inversion that the RAP is showing around 900mb. Moisture is being trapped below this inversion, so expect these clouds to persist into the night. Drizzle may redevelop over the area toward morning. Temperatures did not climb much today and do not have far to fall tonight to reach agreeable MOS guidance for lows. Britt .LONG TERM: (Friday through Next Thursday) Issued at 252 PM CDT Thu Sep 11 2014 Next shortwave to continue sliding southeast into forecast area on Friday. Models in good agreement on timing and precipitation associated with it. Will see isolated/widely scattered showers develop and spread southeast across forecast area during the day on Friday exiting late Friday evening. QPF amounts will be rather light with best chances along and north of I-70. As for temperatures, to remain well below normal with highs only in the upper 50s to upper 60s. Lows Friday night will be in the low 40s to low 50s. Then on Saturday, strong ridge of high pressure to build in and skies to clear out. Despite the sunshine, it will continue to feel like fall with high temperatures only in the 60s and lows Saturday night in the 40s. By Sunday, surface ridge begins to move off to the east allowing temperatures to slowly moderate. Highs will be in the upper 60s to low 70s. Then Sunday night the next weather system to approach the region with showers developing and spread southeast through region Sunday night through Monday night. Frontal boundary to stall out just south of forecast area early Tuesday morning with weak surface ridging building in. Could see some lingering isolated/scattered showers through Wednesday night for western and southern portions of the area. As for temperatures, highs will be in the 70s and lows in the 50s through next Thursday. Byrd && .AVIATION: (For the 18z TAFs through 18z Friday Afternoon) Issued at 1226 PM CDT Thu Sep 11 2014 Expect mainly MVFR conditions to persist through the rest of the TAF period. Current ceilings are expected to improve to above 2000 feet this afternoon, though the are expected to remain below 3000 feet through the night. Ceilings are expected to fall below 2000 feet with some IFR conditions possible between 08-16Z as drizzle redevelops at the terminals. Conditions will then improve again by mid morning Friday. Winds will be north to northeast and and remain under 10kts. Specifics for KSTL: Expect MVFR ceilings to persist through the period, with bases increasing above 2000ft this afternoon. Ceilings will fall back below 2000ft between 09-15Z with -dz redeveloping at the terminal. Improvement is then expected after mid morning Friday. Britt && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1227 PM CDT Thu Sep 11 2014 .UPDATE: Issued at 1059 AM CDT Thu Sep 11 2014 Mainly cloudy skies are expected the rest of the afternoon. The latest RAP soundings are showing moisture being trapped below a inversion at 900mb. This will keep temperatures from climbing much this afternoon given the clouds and northerly winds. Fewer locations are reporting drizzle this last hour, so I expect this trend should continue into the afternoon as the ceilings increase. Britt && .SHORT TERM: (Through Late This Afternoon) Issued at 340 AM CDT Thu Sep 11 2014 A strong surface cold front has moved completely southeast of our region early this morning with an extensive area of low clouds in its wake. The radar mosaic showed the northern edge of the rain was barely edging our region into southern Reynolds and Madison counties in MO. The center of the airmass responsible for this cold front was still well to the northwest of us over southern Alberta province meaning this airmass will take considerable time to build into our area and remain around for awhile. Temps have dipped into the 50s for many areas north of Interstate 70, but remain in the 60s and even lower 70s elsewhere. A strong storm system at the upper levels will dig in across Montana and Wyoming today and actually back the flow across our region to a bit more southwesterly than what it is currently. This should cause the surface front to become quasi-stationary, but still remain well to our south. However, the better moisture in tow behind the front will likely remain across much of southeastern MO and far southern IL thru today. Models loosely depict a wave riding along the stalling frontal boundary later today--more specifically late this morning and early this afternoon--which looks to be a sufficiently northern enough track to justify some mentionable PoP throughout a good portion of the day in the far southern CWA in southeastern MO. Otherwise, the atmosphere drys out enough to go with a dry forecast. Based on PIREPs from last evening, the thickness of the cloud layer currently over us is about 2500ft. We are less than two weeks from the autumnal equinox and with a rather persistently decent CAA at the low levels expected, expect this low cloud to be a bit of a foretaste to the more stubborn cloud cover we will encounter more frequently during the colder months. Favored a more pessimistic cloud cover forecast a la the RAP which doesn`t really start to break things up until later this afternoon and even then may re-gel together tonight. Cloudy skies for much of the day will keep temps down and this looks like it is well handled with the 00z MOS, with maxes in the 60s. TES .LONG TERM: (Tonight through Wednesday) Issued at 340 AM CDT Thu Sep 11 2014 The shortwave now diving into Montana will move into the northeast Plains and Upper Midwest Friday. Latest guidance is in good agreement with the speed and track of the wave as it passes north of the area. Most of the synoptic scale lift ahead of the shortwave will pass north of the CWFA, but we will be in the right rear quadrant of the upper level jet and both the GFS and NAM are also showing bands of frontogenetical forcing moving through Friday afternoon and Friday night. Corresponding light QPF is being produced by the models, so feel pretty confident there will be some light rain. However am not sure how much of this precip will be measurable so am sticking with slight chance to mid chance PoPs Friday afternoon through Friday night as this wave moves through. Zonal flow aloft with a 1030mb Canadian high pressure will control the weather for the weekend. Expect this to provide the Bi-State region with spectacular weather for those who enjoy Autumn, with highs mainly in the mid 60s to low 70s and lows in the 40s. Medium range guidance is indicating a pattern shift in the atmosphere over us toward mid-week from quasi-zonal to northwest flow aloft. The initial wave which will dig into the eastern CONUS is forecast to pass over the Midwest Monday into Monday night. Much like Friday`s wave, the broad synoptic lift associated with the wave should pass north of us with a band of low level frontogenetical forcing ahead of another cold front. Feel low chance PoPs continue to be indicated for Monday and Monday night as this forcing affects the region, and higher PoPs may be needed if the shortwave turns out to be stronger than currently forecast. Another shot of Canadian air will shift across the Midwest Tuesday into the Ohio Valley Wednesday. Stuck close to guidance for temperatures with highs in the 70s and lows in the 50s which continue to be below climatology...although it may not be cool enough given the falling heights and easterly flow as the high moves east of the area. Carney && .AVIATION: (For the 18z TAFs through 18z Friday Afternoon) Issued at 1226 PM CDT Thu Sep 11 2014 Expect mainly MVFR conditions to persist through the rest of the TAF period. Current ceilings are expected to improve to above 2000 feet this afternoon, though the are expected to remain below 3000 feet through the night. Ceilings are expected to fall below 2000 feet with some IFR conditions possible between 08-16Z as drizzle redevelops at the terminals. Conditions will then improve again by mid morning Friday. Winds will be north to northeast and and remain under 10kts. Specifics for KSTL: Expect MVFR ceilings to persist through the period, with bases increasing above 2000ft this afternoon. Ceilings will fall back below 2000ft between 09-15Z with -dz redeveloping at the terminal. Improvement is then expected after mid morning Friday. Britt && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1059 AM CDT Thu Sep 11 2014 .UPDATE: Issued at 1059 AM CDT Thu Sep 11 2014 Mainly cloudy skies are expected the rest of the afternoon. The latest RAP soundings are showing moisture being trapped below a inversion at 900mb. This will keep temperatures from climbing much this afternoon given the clouds and northerly winds. Fewer locations are reporting drizzle this last hour, so I expect this trend should continue into the afternoon as the ceilings increase. Britt && .SHORT TERM: (Through Late This Afternoon) Issued at 340 AM CDT Thu Sep 11 2014 A strong surface cold front has moved completely southeast of our region early this morning with an extensive area of low clouds in its wake. The radar mosaic showed the northern edge of the rain was barely edging our region into southern Reynolds and Madison counties in MO. The center of the airmass responsible for this cold front was still well to the northwest of us over southern Alberta province meaning this airmass will take considerable time to build into our area and remain around for awhile. Temps have dipped into the 50s for many areas north of Interstate 70, but remain in the 60s and even lower 70s elsewhere. A strong storm system at the upper levels will dig in across Montana and Wyoming today and actually back the flow across our region to a bit more southwesterly than what it is currently. This should cause the surface front to become quasi-stationary, but still remain well to our south. However, the better moisture in tow behind the front will likely remain across much of southeastern MO and far southern IL thru today. Models loosely depict a wave riding along the stalling frontal boundary later today--more specifically late this morning and early this afternoon--which looks to be a sufficiently northern enough track to justify some mentionable PoP throughout a good portion of the day in the far southern CWA in southeastern MO. Otherwise, the atmosphere drys out enough to go with a dry forecast. Based on PIREPs from last evening, the thickness of the cloud layer currently over us is about 2500ft. We are less than two weeks from the autumnal equinox and with a rather persistently decent CAA at the low levels expected, expect this low cloud to be a bit of a foretaste to the more stubborn cloud cover we will encounter more frequently during the colder months. Favored a more pessimistic cloud cover forecast a la the RAP which doesn`t really start to break things up until later this afternoon and even then may re-gel together tonight. Cloudy skies for much of the day will keep temps down and this looks like it is well handled with the 00z MOS, with maxes in the 60s. TES .LONG TERM: (Tonight through Wednesday) Issued at 340 AM CDT Thu Sep 11 2014 The shortwave now diving into Montana will move into the northeast Plains and Upper Midwest Friday. Latest guidance is in good agreement with the speed and track of the wave as it passes north of the area. Most of the synoptic scale lift ahead of the shortwave will pass north of the CWFA, but we will be in the right rear quadrant of the upper level jet and both the GFS and NAM are also showing bands of frontogenetical forcing moving through Friday afternoon and Friday night. Corresponding light QPF is being produced by the models, so feel pretty confident there will be some light rain. However am not sure how much of this precip will be measurable so am sticking with slight chance to mid chance PoPs Friday afternoon through Friday night as this wave moves through. Zonal flow aloft with a 1030mb Canadian high pressure will control the weather for the weekend. Expect this to provide the Bi-State region with spectacular weather for those who enjoy Autumn, with highs mainly in the mid 60s to low 70s and lows in the 40s. Medium range guidance is indicating a pattern shift in the atmosphere over us toward mid-week from quasi-zonal to northwest flow aloft. The initial wave which will dig into the eastern CONUS is forecast to pass over the Midwest Monday into Monday night. Much like Friday`s wave, the broad synoptic lift associated with the wave should pass north of us with a band of low level frontogenetical forcing ahead of another cold front. Feel low chance PoPs continue to be indicated for Monday and Monday night as this forcing affects the region, and higher PoPs may be needed if the shortwave turns out to be stronger than currently forecast. Another shot of Canadian air will shift across the Midwest Tuesday into the Ohio Valley Wednesday. Stuck close to guidance for temperatures with highs in the 70s and lows in the 50s which continue to be below climatology...although it may not be cool enough given the falling heights and easterly flow as the high moves east of the area. Carney && .AVIATION: (For the 12z TAFs through 12z Friday Morning) Issued at 652 AM CDT Thu Sep 11 2014 MVFR ceilings are expected to prevail at the TAF sites thru much, if not all, of the valid period. For early this morning, also expect brief periods of drizzle mixed in with some lower ceilings, perhaps to IFR levels. Otherwise, northerly surface winds between 5 and 10 knots will continue. Specifics for KSTL: MVFR ceilings thru the period. Brief periods of drizzle and IFR ceilings also expected with this becoming less likely heading into late morning. Otherwise, northerly winds around 10 knots. TES && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
652 AM CDT Thu Sep 11 2014 .SHORT TERM: (Through Late This Afternoon) Issued at 340 AM CDT Thu Sep 11 2014 A strong surface cold front has moved completely southeast of our region early this morning with an extensive area of low clouds in its wake. The radar mosaic showed the northern edge of the rain was barely edging our region into southern Reynolds and Madison counties in MO. The center of the airmass responsible for this cold front was still well to the northwest of us over southern Alberta province meaning this airmass will take considerable time to build into our area and remain around for awhile. Temps have dipped into the 50s for many areas north of Interstate 70, but remain in the 60s and even lower 70s elsewhere. A strong storm system at the upper levels will dig in across Montana and Wyoming today and actually back the flow across our region to a bit more southwesterly than what it is currently. This should cause the surface front to become quasi-stationary, but still remain well to our south. However, the better moisture in tow behind the front will likely remain across much of southeastern MO and far southern IL thru today. Models loosely depict a wave riding along the stalling frontal boundary later today--more specifically late this morning and early this afternoon--which looks to be a sufficiently northern enough track to justify some mentionable PoP throughout a good portion of the day in the far southern CWA in southeastern MO. Otherwise, the atmosphere drys out enough to go with a dry forecast. Based on PIREPs from last evening, the thickness of the cloud layer currently over us is about 2500ft. We are less than two weeks from the autumnal equinox and with a rather persistently decent CAA at the low levels expected, expect this low cloud to be a bit of a foretaste to the more stubborn cloud cover we will encounter more frequently during the colder months. Favored a more pessimistic cloud cover forecast a la the RAP which doesn`t really start to break things up until later this afternoon and even then may re-gel together tonight. Cloudy skies for much of the day will keep temps down and this looks like it is well handled with the 00z MOS, with maxes in the 60s. TES .LONG TERM: (Tonight through Wednesday) Issued at 340 AM CDT Thu Sep 11 2014 The shortwave now diving into Montana will move into the northeast Plains and Upper Midwest Friday. Latest guidance is in good agreement with the speed and track of the wave as it passes north of the area. Most of the synoptic scale lift ahead of the shortwave will pass north of the CWFA, but we will be in the right rear quadrant of the upper level jet and both the GFS and NAM are also showing bands of frontogenetical forcing moving through Friday afternoon and Friday night. Corresponding light QPF is being produced by the models, so feel pretty confident there will be some light rain. However am not sure how much of this precip will be measurable so am sticking with slight chance to mid chance PoPs Friday afternoon through Friday night as this wave moves through. Zonal flow aloft with a 1030mb Canadian high pressure will control the weather for the weekend. Expect this to provide the Bi-State region with spectacular weather for those who enjoy Autumn, with highs mainly in the mid 60s to low 70s and lows in the 40s. Medium range guidance is indicating a pattern shift in the atmosphere over us toward mid-week from quasi-zonal to northwest flow aloft. The initial wave which will dig into the eastern CONUS is forecast to pass over the Midwest Monday into Monday night. Much like Friday`s wave, the broad synoptic lift associated with the wave should pass north of us with a band of low level frontogenetical forcing ahead of another cold front. Feel low chance PoPs continue to be indicated for Monday and Monday night as this forcing affects the region, and higher PoPs may be needed if the shortwave turns out to be stronger than currently forecast. Another shot of Canadian air will shift across the Midwest Tuesday into the Ohio Valley Wednesday. Stuck close to guidance for temperatures with highs in the 70s and lows in the 50s which continue to be below climatology...although it may not be cool enough given the falling heights and easterly flow as the high moves east of the area. Carney && .AVIATION: (For the 12z TAFs through 12z Friday Morning) Issued at 652 AM CDT Thu Sep 11 2014 MVFR ceilings are expected to prevail at the TAF sites thru much, if not all, of the valid period. For early this morning, also expect brief periods of drizzle mixed in with some lower ceilings, perhaps to IFR levels. Otherwise, northerly surface winds between 5 and 10 knots will continue. Specifics for KSTL: MVFR ceilings thru the period. Brief periods of drizzle and IFR ceilings also expected with this becoming less likely heading into late morning. Otherwise, northerly winds around 10 knots. TES && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
340 AM CDT Thu Sep 11 2014 .SHORT TERM: (Through Late This Afternoon) Issued at 340 AM CDT Thu Sep 11 2014 A strong surface cold front has moved completely southeast of our region early this morning with an extensive area of low clouds in its wake. The radar mosaic showed the northern edge of the rain was barely edging our region into southern Reynolds and Madison counties in MO. The center of the airmass responsible for this cold front was still well to the northwest of us over southern Alberta province meaning this airmass will take considerable time to build into our area and remain around for awhile. Temps have dipped into the 50s for many areas north of Interstate 70, but remain in the 60s and even lower 70s elsewhere. A strong storm system at the upper levels will dig in across Montana and Wyoming today and actually back the flow across our region to a bit more southwesterly than what it is currently. This should cause the surface front to become quasi-stationary, but still remain well to our south. However, the better moisture in tow behind the front will likely remain across much of southeastern MO and far southern IL thru today. Models loosely depict a wave riding along the stalling frontal boundary later today--more specifically late this morning and early this afternoon--which looks to be a sufficiently northern enough track to justify some mentionable PoP throughout a good portion of the day in the far southern CWA in southeastern MO. Otherwise, the atmosphere drys out enough to go with a dry forecast. Based on PIREPs from last evening, the thickness of the cloud layer currently over us is about 2500ft. We are less than two weeks from the autumnal equinox and with a rather persistently decent CAA at the low levels expected, expect this low cloud to be a bit of a foretaste to the more stubborn cloud cover we will encounter more frequently during the colder months. Favored a more pessimistic cloud cover forecast a la the RAP which doesn`t really start to break things up until later this afternoon and even then may re-gel together tonight. Cloudy skies for much of the day will keep temps down and this looks like it is well handled with the 00z MOS, with maxes in the 60s. TES .LONG TERM: (Tonight through Wednesday) Issued at 340 AM CDT Thu Sep 11 2014 The shortwave now diving into Montana will move into the northeast Plains and Upper Midwest Friday. Latest guidance is in good agreement with the speed and track of the wave as it passes north of the area. Most of the synoptic scale lift ahead of the shortwave will pass north of the CWFA, but we will be in the right rear quadrant of the upper level jet and both the GFS and NAM are also showing bands of frontogenetical forcing moving through Friday afternoon and Friday night. Corresponding light QPF is being produced by the models, so feel pretty confident there will be some light rain. However am not sure how much of this precip will be measurable so am sticking with slight chance to mid chance PoPs Friday afternoon through Friday night as this wave moves through. Zonal flow aloft with a 1030mb Canadian high pressure will control the weather for the weekend. Expect this to provide the Bi-State region with spectacular weather for those who enjoy Autumn, with highs mainly in the mid 60s to low 70s and lows in the 40s. Medium range guidance is indicating a pattern shift in the atmosphere over us toward mid-week from quasi-zonal to northwest flow aloft. The initial wave which will dig into the eastern CONUS is forecast to pass over the Midwest Monday into Monday night. Much like Friday`s wave, the broad synoptic lift associated with the wave should pass north of us with a band of low level frontogenetical forcing ahead of another cold front. Feel low chance PoPs continue to be indicated for Monday and Monday night as this forcing affects the region, and higher PoPs may be needed if the shortwave turns out to be stronger than currently forecast. Another shot of Canadian air will shift across the Midwest Tuesday into the Ohio Valley Wednesday. Stuck close to guidance for temperatures with highs in the 70s and lows in the 50s which continue to be below climatology...although it may not be cool enough given the falling heights and easterly flow as the high moves east of the area. Carney && .AVIATION: (For the 06z TAFs through 06z Thursday Night) Issued at 1051 PM CDT Wed Sep 10 2014 Extensive area of MVFR stratus covers the Midwest in the wake of this cold front and have a hard time seeing it dissipating tomorrow. Northwest wind will become north-northeast by tomorrow evening. Specifics for KSTL: MVFR stratus will blanket the region through tomorrow evening. CVKING && .PRELIMINARY POINT TEMPS/POPS: Saint Louis 66 54 66 49 / 0 5 20 30 Quincy 63 49 62 43 / 0 10 30 30 Columbia 66 52 64 45 / 0 5 30 20 Jefferson City 66 53 65 47 / 0 5 30 20 Salem 68 53 67 51 / 5 5 10 30 Farmington 67 52 66 50 / 10 10 10 30 && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
929 PM CDT FRI SEP 12 2014 .UPDATE... ISSUED AT 924 PM CDT FRI SEP 12 2014 OPTED TO EXPAND THE FROST ADVISORY FOR JUST A COUPLE OF COUNTIES WHERE TEMPS ARE FORECAST TO DROP TO NEAR 36. MAY ALSO SEE SOME PATCHY FOG OVERNIGHT. IT MAY BE VERY THIN GROUND FOG...AND MAYBE MORE STEAM FOG NEAR THE RIVERS AND LAKES. MAY HAVE TO ADD TO THE FORECAST IF IT BECOMES WIDESPREAD OR DENSE ENOUGH...AND WILL CONTINUE TO MONITOR THROUGH THE NIGHTTIME. FOG HAD ALREADY DEVELOPED AT CLARINDA IOWA AND MILLARD...AND LATEST RAP MODEL SUGGESTS IT COULD EXPAND ESPECIALLY ACROSS WESTERN IOWA WHERE WINDS WILL PROBABLY REMAIN CALM OVERNIGHT. && .SHORT TERM...(TONIGHT THROUGH MONDAY) ISSUED AT 319 PM CDT FRI SEP 12 2014 ...FIRST FROST OF THE SEASON EXPECTED FOR PARTS OF THE AREA... THE MAIN CONCERN CONCERN FOR THE SHORT TERM CONTS TO BE WITH THE COLD WEATHER TONIGHT. WE FEEL THAT MOST LOCATIONS WILL FALL SHORT OF THE RECORDS LOWS...BUT WITH SKIES CLEARING...WINDS DIMINISHING THIS EVENING...AND THE SFC HIGH CROSSING THE CWA OVERNIGHT WE ARE IN FOR THE COLDEST NIGHT YET OF THE EARLY FALL SEASON. GOING FORECAST LOWS WERE IN GOOD SHAPE AND VERY FEW CHANGES WERE MADE THERE...BUT WE DID GO AHEAD AND ISSUE A FROST ADVRY FOR PARTS OF THE AREA THAT WILL LIKELY SEE A COUPLE HOURS OF TEMPERATURES AT OR BELOW ABOUT 36 DEGREES. RETURN FLOW STARTS TO KICK ON ON SAT BUT TEMPERATURES WILL REMAIN BELOW NORMAL DESPITE THE MIXING TO 850 MB. LOWS TEMPERATURES WILL BE A BIT WARMER ON SAT NIGHT AHEAD OF A FRONT THAT WILL START TO WORK INTO THE MID MO RVR VALLEY ON SUN. ALL MODELS ARE IN PRETTY GOOD AGREEMENT ON THE EVOLUTION OF THE SENSIBLE WX ASSOCIATED WITH THE FRONT ON SUN/SUN NIGHT ALLOWING FOR INCREASED CONFIDENCE AND HIGHER POPS. MOISTURE RETURN WILL BE LIMITED BUT ISENTROPIC LIFT WILL INCREASE DURING THE DAY ON SUN LEADING TO INCREASING CLOUDS...AND AS LARGE-SCALE FORCING FOR ASCENT ALSO INCREASES LATE ON SUN AFTN...AS A SHORT-WAVE TROUGH WORKS THRU SD...WE SHOULD SEE AN INCREASE IN SHRA AND MAYBE AN ISO TSRA OR TWO. THIS CHANCE WILL CONT TO INCREASE ON SUN NIGHT AND WE WILL HAVE SOME LIKELY POPS IN THE CNTRL AND SRN CWA. THE FRONT WILL SHIFT SOUTH OF OUR AREA ON MON ALLOW FOR ANOTHER SHOT OF COOLER AIR TO MOV IN FOR MON AND MON NIGHT AND WE HAVE LOWERED HIGHS/LOWS DURING THIS TIME. .LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT 319 PM CDT FRI SEP 12 2014 SENSIBLE WEATHER WILL BE PRETTY QUIET IN THE EXTENDED PERIOD OF THE FORECAST. THE OVER-ALL PATTERN WILL TRANSITION FROM NORTHWEST FLOW AND COOL AT THE START OF THE PERIOD TO WESTERLY AND A BIT WARMER AT THE END. THE PERIOD WILL GENERALLY BE DRY BUT AS THE UPPER LEVEL FLOW TURNS MORE WEST WE WILL SEE AN INCREASE IN MOISTURE THAT MAY LEAD TO SOME CHC FOR PRECIP TOWARDS THE END OF THE PERIOD...ESPECIALLY IN THE NORTHERN CWA CLOSER TO A BOUNDARY. && .AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 524 PM CDT FRI SEP 12 2014 VFR CONDITIONS INITIALLY WITH CLOUDS DISSIPATING BY 01-03Z WITH WINDS BECOMING LIGHT AND VARIABLE. COULD BE SOME MVFR FOG AT ALL THREE TAF SITES 10-13Z. COULD BE PATCHY FROST AT KLNK/KOFK LATE TONIGHT AS WELL. WINDS BECOME SOUTH TOMORROW MORNING AND INCREASE TO 13 TO 15 KNOTS BY 15-16Z...AND COULD SEE GUSTS AT KOFK UP TO 22 KNOTS THROUGH THE AFTERNOON. MAY ALSO SEE FEW-SCT CUMULUS CLOUDS DEVELOP SATURDAY. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...FROST ADVISORY FROM 3 AM TO 9 AM CDT SATURDAY FOR NEZ015>018- 030>034-042>045-050-051-065-066-078-088-089. IA...FROST ADVISORY FROM 3 AM TO 9 AM CDT SATURDAY FOR IAZ043-055-056- 069-079-080-090-091. && $$ UPDATE...DEWALD SHORT TERM...BOUSTEAD LONG TERM...BOUSTEAD AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1041 PM EDT FRI SEP 12 2014 .SYNOPSIS... A COLD FRONT WILL BRING UNSETTLED WEATHER THROUGH THE WEEKEND. THE FRONT WILL WEAKEN ON MONDAY BUT MOISTURE WILL LINGER FOR A SCATTERING OF SHOWERS ON MONDAY. ANOTHER COLD FRONT SHOULD AFFECT THE REGION ON WEDNESDAY. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... AS OF 10:30 PM FRIDAY...ALTHOUGH MOST OF THE FORECAST AREA THIS EVENING SAW STRATIFORM RAIN OF GRADUALLY DIMINISHING EXTENT...THE CAPE FEAR REGION AND WILMINGTON IN PARTICULAR EXPERIENCED A HEAVY RAIN EVENT COMPLETE WITH LOCALIZED FLOODING. IT APPEARS THAT A SERIES OF UNFORTUNATELY PLACED BOUNDARY COLLISIONS AND A JUICY AIR-MASS WERE RESPONSIBLE. LIGHT TO MODERATE RAIN IS STILL BLANKETING NEW HANOVER COUNTY AND A FLOOD WARNING IS OUT FOR THAT AREA. GIVEN P/W VALUES IN EXCESS OF 2 INCHES SHOWER ACTIVITY AREA- WIDE CONTINUES TO BE A POSSIBILITY...ESPECIALLY GIVEN THE PROXIMITY OF THE COLD FRONT...WHICH SEEMS TO NOW EXTEND ACROSS THE NORTHERN HALF OF THE FORECAST AREA WITH A FRONTAL WAVE NOW PLACED OVER THE CAPE FEAR REGION. THIS ALSO NO DOUBT ENHANCED OUR RECENT BOUT OF HEAVY RAIN. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...ANOTHER FAIRLY UNSETTLED AFTERNOON IN STORE FOR THE REGION SATURDAY AS COLD FRONT ENTERS THE COASTAL PLAIN IN THE PRESENCE OF FAIRLY DEEP TROPICAL MOISTURE. THE MOST WIDESPREAD COVERAGE WILL BE OVER NWRN ZONES WHICH WILL BE MOST PROXIMAL TO THE BOUNDARY...PERHAPS RADAR COVERAGE NOT UNLIKE THAT OF THIS AFTERNOON. WITH A MORE CLOUDY START COMPARED TO TODAY AFTERNOON TEMPERATURES WILL NOT GROW AS HOT AND TEND TO BE QUITE SEASONABLE. PRECIPITABLE WATER REMAINS ABOVE 2 INCHES WHILE STORM MOTION REMAINS BELOW 5KT SO CHANCE FOR HEAVY DOWNPOURS REMAINS INTACT. RAIN CHANCES WILL HAVE A HARD TIME DIPPING MUCH LOWER THAN LOW END CHANCE RANGE SATURDAY NIGHT AS THE FRONT MOVES ATOP OF THE FORECAST AREA...ALTHOUGH THE LOSS OF DAYTIME HEATING SHOULD DIMINISH THEIR INTENSITY AND THE HEAVY RAIN THREAT. WE WIND UP ON THE OTHER SIDE OF THE FRONT ON SUNDAY AS IT REMAINS NEARLY STALLED TO OUR SOUTH AND EAST. RAIN CHANCES WILL BE SHIFTED SOUTH AND EAST ACCORDINGLY AND THE HEAVY RAIN THREAT WILL BE RELATIVELY MITIGATED. SUNDAY AFTERNOON MAY OFFER UP A RANGE OF HIGH TEMPERATURES FROM NORTH TO SOUTH FROM THE UPPER 70S TO THE MID 80S. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 3 PM FRIDAY...WEAKENING FRONT STALLED IN THE AREA AT THE START OF THE PERIOD AND DEEP TROPICAL MOISTURE ENSURE THE FIRST HALF OF NEXT WEEK REMAIN UNSETTLED. PRECIPITABLE WATER VALUES AROUND 2 INCHES MON AND TUE IN A MODERATELY UNSTABLE AIRMASS SHOULD LEAD TO SHOWER AND THUNDERSTORM DEVELOPMENT. PLAN TO CARRY CHC POP WITH A DIURNAL DISTRIBUTION. THE LACK OF FORCING ALOFT SHOULD LEAD TO A DECREASE IN COVERAGE/ACTIVITY OVERNIGHT BUT DO NOT THINK STORMS WILL COMPLETELY DISSIPATE. STORM MOTIONS WILL REMAIN 10 KT OR LESS WHICH WILL MAINTAIN FLOODING POTENTIAL. A STRONGER COLD FRONT WILL DROP IN FROM THE NORTHWEST MID WEEK. THIS FRONT HAS A MORE DEFINED TROUGH BEHIND IT WHICH WILL PUSH THE BOUNDARY SOUTH OF THE AREA BY THE END OF THE WEEK. HOWEVER THERE IS STILL SOME UNCERTAINTY AS TO HOW FAR SOUTH THIS FRONT MOVES BEFORE STALLING. ECMWF HAS THE FRONT FARTHER SOUTH...SO DOES WPC...WHILE THE GFS KEEPS THE FRONT CLOSER TO THE CAROLINAS. BOTH MEDIUM RANGE SOLUTIONS DEVELOP A WEAK LOW ON THE FRONT AND LIFT IT NORTH...THOUGH TIMING IS DIFFERENT. ECMWF SOLUTION WOULD PRODUCE SLIGHT CHC TO LOW CHC OF PRECIP THROUGH THU...MAINLY ALONG THE COAST...WITH DRYING FRI. GFS IS WETTER WITH HIGH CHC TO LIKELY POP THROUGH THE END OF THE PERIOD FOR MUCH OF THE FORECAST AREA. PREVIOUS FORECASTS HAVE BEEN IN LINE WITH THE DRIER ECMWF/WPC SOLUTION AND AT THIS POINT CAN SEE NO REASON TO MAKE A CHANGE. CONFIDENCE REMAINS LOW SO SIGNIFICANT CHANGES IN LATER FORECASTS IS STILL A POSSIBILITY. TEMPERATURE RANGES EARLY IN THE PERIOD WILL BE ON THE NARROW END WITH CLOUD COVER AND PRECIP KEEPING HIGHS NEAR TO SLIGHTLY BELOW CLIMO BUT HELPING HOLD LOWS SEVERAL DEGREES ABOVE CLIMO. PASSAGE OF FRONT MID WEEK WILL BRING BELOW CLIMO TEMPS FOR THE END OF THE WEEK. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... AS OF 00Z...EXPECT SHRA/TSRA TO END EARLY THIS EVENING...WITH WIDESPREAD STRATIFORM LIGHT RAIN DECREASING THEN ENDING AROUND MIDNIGHT. THE HRRR MODELS SUGGESTS SOME ISOLATED CONVECTIVE SHOWERS MAY REDEVELOP AROUND MIDNIGHT NEAR KILM AND 10Z NEAR KLBT. UNTIL CONVECTION DISSIPATES THIS EVENING THERE WILL BE A CHANCE OF TEMPO MVFR CONDITIONS. BRIEF IFR POSSIBLE IF A SHOWER MOVES DIRECTLY OVER A TERMINAL...BUT CONFIDENCE IS LOW. GENERALLY EXPECT THICK MID/UPPER CLOUD COVER THROUGH THE TAF VALID PERIOD WITH COPIOUS AMOUNTS OF LOW LEVEL MOISTURE. IFR/LIFR CONDITIONS WILL DEVELOP AFTER 08Z AT KLBT/KILM/FLO WITH HIGHEST CONFIDENCE AT KLBT/KILM WHICH IS NEAREST THE STATIONARY FRONT. KCRE/KMYR ARE MORE LIKELY TO EXPERIENCE MVFR CONDITIONS OVERNIGHT. IFR LIFTS FAIRLY QUICKLY SATURDAY MORNING WITH VFR DEVELOPING AT ALL TERMINALS BY 18Z. CLOUD COVER SHOULD INHIBIT HEATING AND LIFT SO THINK WORSE CASE VCSH COASTAL TERMINALS IN THE MORNING HOURS. BY AFTERNOON THUNDERSTORM POTENTIAL SHOULD BE GREATEST AT KFLO/KLBT. EXTENDED OUTLOOK...A CHANCE OF SHOWERS WITH MAINLY AFTERNOON THUNDERSTORMS/TEMPO MVFR THROUGH TUESDAY. && .MARINE... NEAR TERM/THROUGH TONIGHT/... AS OF 10:30 PM FRIDAY...LIGHT AND VARIABLE WINDS WITH 2 FT SEAS CONTINUE ACROSS THE WATERS THIS EVENING. FORECAST REMAINS UNCHANGED. PREVIOUS DISCUSSION FOLLOWS: OUTSIDE OF TSTMS NO REAL PROBLEMS EXPECTED ON THE WATERS WITH LIGHT WINDS OVERALL AND SEAS 2 FEET OR LESS...AS A WEAK FRONTAL BOUNDARY REMAINS IN VICINITY OF THE AREA. MOST STORMS SHOULD STAY OVER LAND BUT TONIGHT CELLS MAY BEGIN TO FAVOR THE 0-20 NM WATERS. SEAS AROUND 2 FEET IN A MIX OF SE WAVES 1-1.5 FT EVERY 8-9 SECONDS AND S WAVES 0.5-1 FT EVERY 3-4 SECONDS. WITHIN TSTMS WINDS AND SEAS WILL BE LOCALLY AND SIGNIFICANTLY HIGHER. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...PREFRONTAL SOUTHWESTERLY FLOW ON SATURDAY SHOULD REMAIN AT 10 KT PREVENTING SEAS FROM ATTAINING HEIGHTS MORE THAN 2 FT. LATE SATURDAY NIGHT AS THE FRONT DRAWS NEAR THE COAST THERE MAY BE A GENTLE BACKING OF THE FLOW FOLLOWED BY A MORE PRECIPITOUS VEER ON SUNDAY ASSOCIATED WITH ACTUAL FROPA. THE FRONT WILL NOT MOVE VERY FAR TO OUR SOUTH BEFORE STALLING WHICH PRECLUDES MUCH OF A SURGE OF HIGH PRESSURE AND THUS ANY HIGHER WINDS. THUS THE VEER TO ENE FLOW APPEARS TO BE THE MAIN EFFECT OF THE FROPA AS WIND SPEEDS AND WAVE HEIGHTS REMAIN UNCHANGED...ALTHOUGH WAVE PERIODS MAY SHORTEN UP A BIT. LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 3 PM FRIDAY...DIMINISHING NORTHERLY SURGE AT THE START OF THE PERIOD WILL LEAVE LIGHT AND VARIABLE WINDS OVER THE WATERS FOR MUCH OF MON AND TUE GIVEN PROXIMITY TO THE STALLED FRONT. ANOTHER COLD FRONT WILL DROP IN FROM THE NORTHWEST DURING THE SECOND HALF OF THE PERIOD. THIS FRONT IS MORE DEFINED AND SHOULD BE ACCOMPANIED BY A STRONGER NORTHERLY SURGE LATER WED INTO WED NIGHT. WINDS WILL APPROACH A SOLID 15 KT WED NIGHT WITH GUSTS AROUND 20 KT POSSIBLE. SEAS 2 TO 3 FT FOR MUCH OF THE PERIOD WILL BUILD AS HIGH AS 5 FT AS THE PERIOD ENDS DUE TO THE PROLONGED AND STEADILY INCREASING NATURE OF THE NORTHERLY SURGE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...MJC/REK SHORT TERM...MBB LONG TERM...III AVIATION...MRR MARINE...MJC/REK/III/MBB
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
735 PM EDT FRI SEP 12 2014 .SYNOPSIS... A COLD FRONT WILL BRING UNSETTLED WEATHER THROUGH THE WEEKEND. THE FRONT WILL WEAKEN ON MONDAY BUT MOISTURE WILL LINGER FOR A SCATTERING OF SHOWERS ON MONDAY. ANOTHER COLD FRONT SHOULD AFFECT THE REGION ON WEDNESDAY. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... AS OF 7:30 PM FRIDAY...CONVECTION FROM THIS AFTERNOON HAS TRANSITIONED TO A WIDESPREAD LIGHT STRATIFORM RAIN EVENT THIS EVENING. THERE ARE A FEW EMBEDDED SHORT-LIVED THUNDERSTORMS...BUT THEY ARE ALSO ON THE WANE. INSTABILITY PRETTY MUCH TAPPED OUT AND CONVECTIVE ACTIVITY WAS ALMOST ENTIRELY DIURNALLY-DRIVEN...SO EXPECT A GRADUAL DECREASE IN AREAL COVERAGE OF LIGHT RAIN THROUGH MIDNIGHT...WITH SPOTTY SHOWERS THEREAFTER. HAVE UPDATED FORECAST ACCORDINGLY. RELEVANT PORTION OF PREVIOUS DISCUSSION FOLLOWS: A FEW IMPULSES ALOFT TRAVERSING THE SFC BOUNDARY WILL LIKELY KEEP A CHANCE OF SHRA/TSTMS GOING INTO THE OVERNIGHT...BUT OVERALL RAIN-RATES AND STORM COVERAGE IS EXPECTED TO SHOW SOME SCALING BACK AS SURFACE HEATING TAILS OFF AND IS TAPPED INTO OVER THE NEXT 8 HOURS. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...ANOTHER FAIRLY UNSETTLED AFTERNOON IN STORE FOR THE REGION SATURDAY AS COLD FRONT ENTERS THE COASTAL PLAIN IN THE PRESENCE OF FAIRLY DEEP TROPICAL MOISTURE. THE MOST WIDESPREAD COVERAGE WILL BE OVER NWRN ZONES WHICH WILL BE MOST PROXIMAL TO THE BOUNDARY...PERHAPS RADAR COVERAGE NOT UNLIKE THAT OF THIS AFTERNOON. WITH A MORE CLOUDY START COMPARED TO TODAY AFTERNOON TEMPERATURES WILL NOT GROW AS HOT AND TEND TO BE QUITE SEASONABLE. PRECIPITABLE WATER REMAINS ABOVE 2 INCHES WHILE STORM MOTION REMAINS BELOW 5KT SO CHANCE FOR HEAVY DOWNPOURS REMAINS INTACT. RAIN CHANCES WILL HAVE A HARD TIME DIPPING MUCH LOWER THAN LOW END CHANCE RANGE SATURDAY NIGHT AS THE FRONT MOVES ATOP OF THE FORECAST AREA...ALTHOUGH THE LOSS OF DAYTIME HEATING SHOULD DIMINISH THEIR INTENSITY AND THE HEAVY RAIN THREAT. WE WIND UP ON THE OTHER SIDE OF THE FRONT ON SUNDAY AS IT REMAINS NEARLY STALLED TO OUR SOUTH AND EAST. RAIN CHANCES WILL BE SHIFTED SOUTH AND EAST ACCORDINGLY AND THE HEAVY RAIN THREAT WILL BE RELATIVELY MITIGATED. SUNDAY AFTERNOON MAY OFFER UP A RANGE OF HIGH TEMPERATURES FROM NORTH TO SOUTH FROM THE UPPER 70S TO THE MID 80S. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 3 PM FRIDAY...WEAKENING FRONT STALLED IN THE AREA AT THE START OF THE PERIOD AND DEEP TROPICAL MOISTURE ENSURE THE FIRST HALF OF NEXT WEEK REMAIN UNSETTLED. PRECIPITABLE WATER VALUES AROUND 2 INCHES MON AND TUE IN A MODERATELY UNSTABLE AIRMASS SHOULD LEAD TO SHOWER AND THUNDERSTORM DEVELOPMENT. PLAN TO CARRY CHC POP WITH A DIURNAL DISTRIBUTION. THE LACK OF FORCING ALOFT SHOULD LEAD TO A DECREASE IN COVERAGE/ACTIVITY OVERNIGHT BUT DO NOT THINK STORMS WILL COMPLETELY DISSIPATE. STORM MOTIONS WILL REMAIN 10 KT OR LESS WHICH WILL MAINTAIN FLOODING POTENTIAL. A STRONGER COLD FRONT WILL DROP IN FROM THE NORTHWEST MID WEEK. THIS FRONT HAS A MORE DEFINED TROUGH BEHIND IT WHICH WILL PUSH THE BOUNDARY SOUTH OF THE AREA BY THE END OF THE WEEK. HOWEVER THERE IS STILL SOME UNCERTAINTY AS TO HOW FAR SOUTH THIS FRONT MOVES BEFORE STALLING. ECMWF HAS THE FRONT FARTHER SOUTH...SO DOES WPC...WHILE THE GFS KEEPS THE FRONT CLOSER TO THE CAROLINAS. BOTH MEDIUM RANGE SOLUTIONS DEVELOP A WEAK LOW ON THE FRONT AND LIFT IT NORTH...THOUGH TIMING IS DIFFERENT. ECMWF SOLUTION WOULD PRODUCE SLIGHT CHC TO LOW CHC OF PRECIP THROUGH THU...MAINLY ALONG THE COAST...WITH DRYING FRI. GFS IS WETTER WITH HIGH CHC TO LIKELY POP THROUGH THE END OF THE PERIOD FOR MUCH OF THE FORECAST AREA. PREVIOUS FORECASTS HAVE BEEN IN LINE WITH THE DRIER ECMWF/WPC SOLUTION AND AT THIS POINT CAN SEE NO REASON TO MAKE A CHANGE. CONFIDENCE REMAINS LOW SO SIGNIFICANT CHANGES IN LATER FORECASTS IS STILL A POSSIBILITY. TEMPERATURE RANGES EARLY IN THE PERIOD WILL BE ON THE NARROW END WITH CLOUD COVER AND PRECIP KEEPING HIGHS NEAR TO SLIGHTLY BELOW CLIMO BUT HELPING HOLD LOWS SEVERAL DEGREES ABOVE CLIMO. PASSAGE OF FRONT MID WEEK WILL BRING BELOW CLIMO TEMPS FOR THE END OF THE WEEK. && .AVIATION /23Z FRIDAY THROUGH WEDNESDAY/... AS OF 00Z...EXPECT SHRA/TSRA TO END EARLY THIS EVENING...WITH WIDESPREAD STRATIFORM LIGHT RAIN DECREASING THEN ENDING AROUND MIDNIGHT. THE HRRR MODELS SUGGESTS SOME ISOLATED CONVECTIVE SHOWERS MAY REDEVELOP AROUND MIDNIGHT NEAR KILM AND 10Z NEAR KLBT. UNTIL CONVECTION DISSIPATES THIS EVENING THERE WILL BE A CHANCE OF TEMPO MVFR CONDITIONS. BRIEF IFR POSSIBLE IF A SHOWER MOVES DIRECTLY OVER A TERMINAL...BUT CONFIDENCE IS LOW. GENERALLY EXPECT THICK MID/UPPER CLOUD COVER THROUGH THE TAF VALID PERIOD WITH COPIOUS AMOUNTS OF LOW LEVEL MOISTURE. IFR/LIFR CONDITIONS WILL DEVELOP AFTER 08Z AT KLBT/KILM/FLO WITH HIGHEST CONFIDENCE AT KLBT/KILM WHICH IS NEAREST THE STATIONARY FRONT. KCRE/KMYR ARE MORE LIKELY TO EXPERIENCE MVFR CONDITIONS OVERNIGHT. IFR LIFTS FAIRLY QUICKLY SATURDAY MORNING WITH VFR DEVELOPING AT ALL TERMINALS BY 18Z. CLOUD COVER SHOULD INHIBIT HEATING AND LIFT SO THINK WORSE CASE VCSH COASTAL TERMINALS IN THE MORNING HOURS. BY AFTERNOON THUNDERSTORM POTENTIAL SHOULD BE GREATEST AT KFLO/KLBT. EXTENDED OUTLOOK...A CHANCE OF SHOWERS WITH MAINLY AFTERNOON THUNDERSTORMS/TEMPO MVFR THROUGH TUESDAY. && .MARINE... NEAR TERM/THROUGH TONIGHT/... AS OF 7:30 PM FRIDAY...LIGHT AND VARIABLE WINDS WITH 2 FT SEAS CONTINUE ACROSS THE WATERS THIS EVENING. FORECAST REMAINS UNCHANGED. PREVIOUS DISCUSSION FOLLOWS: OUTSIDE OF TSTMS NO REAL PROBLEMS EXPECTED ON THE WATERS WITH LIGHT WINDS OVERALL AND SEAS 2 FEET OR LESS...AS A WEAK FRONTAL BOUNDARY REMAINS IN VICINITY OF THE AREA. MOST STORMS SHOULD STAY OVER LAND BUT TONIGHT CELLS MAY BEGIN TO FAVOR THE 0-20 NM WATERS. SEAS AROUND 2 FEET IN A MIX OF SE WAVES 1-1.5 FT EVERY 8-9 SECONDS AND S WAVES 0.5-1 FT EVERY 3-4 SECONDS. WITHIN TSTMS WINDS AND SEAS WILL BE LOCALLY AND SIGNIFICANTLY HIGHER. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...PREFRONTAL SOUTHWESTERLY FLOW ON SATURDAY SHOULD REMAIN AT 10 KT PREVENTING SEAS FROM ATTAINING HEIGHTS MORE THAN 2 FT. LATE SATURDAY NIGHT AS THE FRONT DRAWS NEAR THE COAST THERE MAY BE A GENTLE BACKING OF THE FLOW FOLLOWED BY A MORE PRECIPITOUS VEER ON SUNDAY ASSOCIATED WITH ACTUAL FROPA. THE FRONT WILL NOT MOVE VERY FAR TO OUR SOUTH BEFORE STALLING WHICH PRECLUDES MUCH OF A SURGE OF HIGH PRESSURE AND THUS ANY HIGHER WINDS. THUS THE VEER TO ENE FLOW APPEARS TO BE THE MAIN EFFECT OF THE FROPA AS WIND SPEEDS AND WAVE HEIGHTS REMAIN UNCHANGED...ALTHOUGH WAVE PERIODS MAY SHORTEN UP A BIT. LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 3 PM FRIDAY...DIMINISHING NORTHERLY SURGE AT THE START OF THE PERIOD WILL LEAVE LIGHT AND VARIABLE WINDS OVER THE WATERS FOR MUCH OF MON AND TUE GIVEN PROXIMITY TO THE STALLED FRONT. ANOTHER COLD FRONT WILL DROP IN FROM THE NORTHWEST DURING THE SECOND HALF OF THE PERIOD. THIS FRONT IS MORE DEFINED AND SHOULD BE ACCOMPANIED BY A STRONGER NORTHERLY SURGE LATER WED INTO WED NIGHT. WINDS WILL APPROACH A SOLID 15 KT WED NIGHT WITH GUSTS AROUND 20 KT POSSIBLE. SEAS 2 TO 3 FT FOR MUCH OF THE PERIOD WILL BUILD AS HIGH AS 5 FT AS THE PERIOD ENDS DUE TO THE PROLONGED AND STEADILY INCREASING NATURE OF THE NORTHERLY SURGE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...MJC/REK SHORT TERM...MBB LONG TERM...III AVIATION...MRR MARINE...MJC/REK/III/MBB
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
132 PM EDT THU SEP 11 2014 .SYNOPSIS... LATE SUMMER WEATHER CAN BE EXPECTED TODAY AHEAD OF A COLD FRONT APPROACHING FROM THE NORTHWEST. THE FRONT WILL BRING AN INCREASING CHANCE OF SHOWERS AND STORMS FRIDAY THROUGH MONDAY. A SERIES OF CANADIAN HIGH PRESSURE SYSTEMS WILL BUILD INTO THE REGION A GOOD PORTION OF NEXT WEEK...BRINGING A FEEL OF EARLY FALL TO THE AREA. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1045 AM THURSDAY...TRIMMED MAXIMUM TEMPERATURES A DEGREE OR 2 ACROSS THE CAPE FEAR REGION DUE TO HIGH LAYERED BUT IMPACTFUL CLOUDS PRESENTLY SAILING SOUTH OVER A SWATH OF PENDER AND NEW HANOVER COUNTIES. OTHERWISE LITTLE CHANGE TO EXPECTED HIGHS TODAY AND THIS IS SHAPING UP TO BE OUR WARMEST DAY IN A WHILE AND FOR A WHILE...AS A COLD EDGES CLOSER TO THE REGION FROM THE NORTHWEST. STRONG INSOLATION WILL CERTAINLY PROMPT CUMULUS DEVELOPMENT THIS AFTERNOON...AND SATELLITE BASED PWAT DETECTORS ARE REGISTERING INCREASING COLUMN MOISTURE OVER THE AREA IN THE INCREASINGLY WARM PRE-FRONTAL AIR MASS HERE LOCALLY. THUS WITH DEWPOINT EXPECTATIONS COUPLED WITH MAX T TODAY WILL RESULT IN MAX APPARENT TEMPERATURES IN THE 90S MOST AREAS. THE OTHER CHANGE WAS TO REMOVE MENTIONABLE POP VALUES FOR THE DAYTIME PERIOD TODAY AS IT APPEARS DRY AIR WILL REMAIN IN PLACE ABOVE 9-10KFT. WHILE A RAINDROP CANNOT BE RULED OUT COMPLETELY ALONG THE MAXIMUM OF SEA BREEZE CONVERGENCE...AM BASING POPS ON MEASURABLE RAINFALL PROBABILITY...AND THIS IS LESS THAN 15 PCNT THROUGH AFTERNOON. LAND VS SEA TEMPERATURE DIFFERENTIAL SHOULD PROPEL A HEALTHY SEA BREEZE CIRCULATION BY THE MIDDLE/LATE AFTN. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 300 AM THURSDAY...COLD FRONT WILL MOVE ACROSS THE CAROLINAS ON FRIDAY WITH INCREASING CLOUDS AND CHC OF SHWRS/TSTMS THROUGH THE DAY. THE FRONT WILL SLOW DOWN AND STALL OUT IN THE VICINITY OF LOCAL FORECAST AREA AS SHORTWAVE PUSHING THIS FRONT COMES UP AGAINST A DECENT RIDGE IN PLACE ACROSS THE SOUTHEAST AND RIDES UP TO THE NORTHEAST...LEAVING A FLOW MORE PARALLEL TO FRONT. THE NEXT SHORTWAVE SHOULD NUDGE THE FRONT A LITTLE FARTHER SOUTH SAT NIGHT BUT LOOKS LIKE IT MAY STILL REMAIN STRETCHED JUST ALONG THE SOUTHEAST COAST. LATEST GFS RUN WAS A LITTLE FASTER...MOVING THE FRONT INTO THE CAPE FEAR REGION BY FRI AFTERNOON. THE MAIN SHORTWAVE ENERGY WILL REMAIN WELL NORTH OF AREA BUT CONVERGENCE ALONG THE COLD FRONT ALONG WITH A SATURATED COLUMN WILL PRODUCE SOME HIGHER END QPF AMOUNTS OVER FORECAST AREA. THE PCP WATER VALUES REACH ABOVE 2.25 INCHES WITH BULLSEYE OVER LOCAL FORECAST AREA BY FRI AFTN AND REMAINING ABOVE 2 INCHES THROUGH THE WEEKEND. OVERALL EXPECT A CLOUDY AND WET FORECAST FOR THE WEEKEND. TEMPS OVER SOUTHEAST NORTH CAROLINA WILL MAKE A RUN FOR 80 DEGREES ON FRIDAY BEFORE FRONT MOVES IN WHILE TEMPS IN NORTHEAST SOUTH CAROLINA SHOULD MAKE IT INTO THE MID 80S. CLOUDS...SHOWERS AND LIGHT NORTHERLY FLOW WILL KEEP TEMPS BELOW NORMAL FOR HIGHS AND ABOVE NORMAL FOR OVERNIGHT LOWS FRIDAY AND SATURDAY. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 300 AM THURSDAY...SHORTWAVES RIDING AROUND BROAD TROUGH OVER THE GREAT LAKES WILL PUSH PERSISTENT RIDGE OVER THE SOUTHERN CONUS A LITTLE FARTHER SOUTH THROUGH EARLY NEXT WEEK. THE COLD FRONT CAUGHT IN BETWEEN WILL REMAIN HUNG UP IN THE VICINITY PRODUCING PLENTY OF CLOUDS AND UNSETTLED WEATHER THROUGH MUCH OF THE WEEK. WILL KEEP CLOUDS AND CHC POPS IN FORECAST THROUGH AT LEAST TUES. THE BROAD MID TO UPPER TROUGH OVER THE GREAT LAKES WILL DIG FARTHER SOUTH THROUGH TUES AND MAY PUSH FAR ENOUGH SOUTH TO ALLOW DRIER AIR TO MOVE IN. HIGH PRESSURE WILL BUILD DOWN INTO THE SOUTHEAST BUT COLD FRONT WILL LINGER THROUGH THE WEEK...PERHAPS REMAINING FAR ENOUGH SOUTH BY TUES TO ALLOW FOR SOME DRIER WEATHER FOR MID WEEK. FOR NOW WILL KEEP CLOUDS AND PCP IN FORECAST AS WINDS ALOFT OUT OF THE W-SW WILL RIDE OVER THE COOLER NORTHERLY FLOW TO SUPPORT LIFT THROUGHOUT MUCH OF THE PERIOD. SHOULD END UP WITH A DECENT QPF SPREAD OVER SEVERAL DAYS. THE COOLER NORTHERLY FLOW ALONG WITH CLOUDS AND PCP WILL ALL COMBINE TO KEEP TEMPS BELOW NORMAL MOST DAYS AND OVERNIGHT LOWS JUST ABOVE NORMAL. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... AS OF 18Z...FRONTAL BOUNDARY SLOW APPROACHING THROUGH THE FORECAST PERIOD. THE HRRR DOES DEPICT SOME ISOLATED CONVECTION ALONG THE SEA BREEZE...VERY ISOLATED AND NOT ENOUGH FOR A MENTION IN THE TAFS. SOUTHERLY FLOW ON THE EAST SIDE OF THE RESULTANT. TONIGHT...INCREASING CLOUDINESS TOWARD MORNING AS THE FRONT APPROACHES. IF WE DO NOT GET A CEILING SOON ENOUGH HOWEVER...SOME FOG MAY FORM...POSSIBLY PRETTY DENSE. WILL GO WITH THE CEILING SCENARIO FOR NOW WITH ONLY LIGHT FOG. FRIDAY...CONVECTION BREAKING OUT FROM WEST TO EAST. THE LATEST NAM IS NOT SO ENTHUSED WITH ONLY ISOLATED ACTIVITY ALONG THE COAST BY AFTERNOON. EXTENDED OUTLOOK...INCREASING CHANCES FOR SHOWERS/TSTMS AND TEMPO MVFR FRIDAY AFTERNOON THROUGH THE WEEKEND WITH AN APPROACHING COLD FRONT. THE FRONT STALLS WITH A CONTINUED CHANCE FOR PRECIP THROUGH TUESDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1045 AM THURSDAY...SFC RIDGING FROM THE WESTERN ATLANTIC HIGH...WILL PERSIST ACROSS AND AFFECT THE ILM COASTAL WATERS THROUGH TONIGHT. THE SFC PRESSURE PATTERN WILL PRODUCE S-SW WIND DIRECTIONS...THE SFC PRESSURE GRADIENT WILL REMAIN LOOSE INTO THIS EVENING AND THUS PRODUCING AROUND 10 KT WIND SPEEDS. THE LOCAL SEA BREEZE CIRCULATION WILL PROVIDE AN ADDITIONAL 5 KT THIS AFTERNOON AND EARLY TONIGHT WITH 10-15 KT BECOMING COMMON ESPECIALLY NEARSHORE OR WITHIN 10 NM OF THE COAST. FOR TONIGHT...THE COLD FRONT DROPPING SE-WARD...WILL PUSH CLOSER TO THE AREA WATERS. THE END RESULT WILL BE A SLIGHT TIGHTENING OF THE SFC PG. WILL HIGHLIGHT WITH SW WINDS INCREASING TO 10-15 KT. SIGNIFICANT SEAS WILL HOVER AROUND 2 FT...BUILDING TO 2 TO 3 FT THIS AFTN AND TONIGHT DUE TO THE INCREASE OF LOW PERIOD WIND DRIVEN WAVES. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 300 AM THURSDAY...LIGHT SOUTHERLY FLOW AHEAD OF AN APPROACHING COLD FRONT ON FRIDAY WILL COME AROUND TO THE N-NE BY FRI NIGHT BUT WILL REMAIN FAIRLY LIGHT IN AN OTHERWISE WEAKER GRADIENT FLOW. OVERALL EXPECT WINDS LESS THAN 10 KTS THROUGH MUCH OF THE WEEKEND. THIS WILL KEEP SEAS LESS THAN 3 FT FOR THE MOST PART ACROSS THE LOCAL WATERS. LONG TERM /SUNDAY THROUGH MONDAY/... AS OF 300 AM THURSDAY...A SLOW MOVING COLD FRONT SHOULD GET ANOTHER NUDGE SOUTHWARD EARLY SUNDAY HELPING IT TO PROGRESS SOUTH THROUGH EARLY NEXT WEEK...BUT GRADIENT WILL REMAIN RELAXED KEEPING WINDS LESS THAN 10 KTS. SEAS WILL REMAIN LESS THAN 3 FT THROUGH THE PERIOD. && .TIDES/COASTAL FLOODING... AS OF 1045 AM THURSDAY...LATEST TIDE FORECASTS FOR THE CAPE FEAR RIVER GAGE IN THE VICINITY OF DOWNTOWN WILMINGTON IS EXPECTED TO APPROACH 6.00 FT MLLW AROUND NOON TODAY. THIS IS NEARLY HALF A FOOT ABOVE THE THRESHOLD FOR COASTAL FLOODING TO OCCUR. IN ADDITION...WATER ACROSS CANAL DRIVE OF CAROLINA BEACH IS CORRELATED TO THE CAPE FEAR RIVER GAGE REACHING NEAR 6.00 FT MLLW. A CFW HAS BEEN ISSUED AND IS IN EFFECT BETWEEN 11AM AND 2PM AT WHICH TIME GAGE READINGS WILL BE AT OR ABOVE 5.5 FT MLLW. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...COASTAL FLOOD ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR NCZ107-108. MARINE...NONE. && $$ SYNOPSIS...MJC NEAR TERM...MJC SHORT TERM...RGZ LONG TERM...RGZ AVIATION...DL/8 TIDES...DOUGH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1146 AM CDT THU SEP 11 2014 .UPDATE... ISSUED AT 1146 AM CDT THU SEP 11 2014 SURFACE-BASED ISOLATED SHOWER ACTIVITY HAS ALREADY DEVELOPED OVER CENTRAL NORTH DAKOTA IN THE AREAS WHERE MID/UPPER LEVEL CLOUDS HAVE CLEARED OUT. IT LOOKS LIKE THE LATEST HRRR IS VERIFYING THE AREAL COVERAGE OF ISOLATED SHOWER ACTIVITY. AS A RESULT...UPDATED THE FORECAST REFLECT THE LATEST HRRR SOLUTION AND ADDED ISOLATED SHOWERS OVER ALL OF WESTERN AND CENTRAL NORTH DAKOTA TO THE AFTERNOON FORECAST. THE REMAINING FORECAST ELEMENTS ARE IN GOOD SHAPE. THE UPDATED PRODUCTS WILL BE OUT SHORTLY. UPDATE ISSUED AT 1006 AM CDT THU SEP 11 2014 CLOUDS ARE BEGINNING TO BREAK OVER WESTERN AND CENTRAL NORTH DAKOTA. TEMPERATURES ARE RESPONDING BY JUMPING INTO THE 40S WITHIN THE LAST HOUR. BOWMAN RADAR SHOWS ALL RETURNS SOUTH OF THE STATE. HOWEVER...MAINTAINED CHANCE OF LIGHT RAIN SOUTHWEST THROUGH THE THE MORNING AS A BAROCLINIC ZONE WILL BE IN THE VICINITY. ELSEWHERE...THE LATEST ARW AND NMM MESOSCALE MODELS PROG ISOLATED TO SCATTERED SHOWER ACTIVITY DEVELOPING SOUTHWEST OF THE MISSOURI RIVER THIS AFTERNOON. THE LATEST HRRR PROGS ISOLATED SHOWERS DEVELOPING CWA-WIDE THIS AFTERNOON. GIVEN THE PROXIMITY OF THE MOISTURE AND SUBTLE MUCAPE...WILL KEEP AFTERNOON POPS CONFINED TO AREAS SOUTHWEST OF THE MISSOURI RIVER...SIMILAR TO THE ARW AND NMM SOLUTIONS. AS A RESULT...CHANGED AFTERNOON WEATHER PRECIP TYPE WORDING FROM STRATIFORM RAIN TO CONVECTIVE SHOWERS. THE UPDATED PRODUCTS WILL BE OUT SHORTLY. UPDATE ISSUED AT 645 AM CDT THU SEP 11 2014 LATEST SATELLITE IMAGERY SHOWS UPPER LEVEL TROUGH DROPPING SOUTH THROUGH THE NORTHERN ROCKIES WITH STRONG JET EXTENDING FROM THE BASE OF THE TROUGH EAST INTO THE NORTHERN PLAINS. LATEST RADAR IMAGERY INDICATES THE MAJORITY OF THE PRECIPITATION REMAINING SOUTH OF THE FORECAST AREA...WITH FAR SOUTHWEST BOWMAN COUNTY SEEING SOME LIGHT RETURNS. MADE SOME MINOR ADJUSTMENTS TO POPS...CONFINING THEM TO THE FAR SOUTHWEST EARLY THIS MORNING. IF WE SEE SOME BREAKS IN THE CLOUDS TODAY...STRONG LOW LEVEL LAPSE RATES SHOULD AID IN SHOWER DEVELOPMENT FARTHER NORTH AND EAST. LATEST HRRR DEVELOPS ISOLATED CONVECTION ACROSS THE CWA BY THIS AFTERNOON. FOR NOW WILL KEEP POPS LIMITED TO THE SOUTHWEST QUARTER AS PREVIOUSLY FORECAST. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 346 AM CDT THU SEP 11 2014 FREEZING TEMPERATURES TONIGHT HIGHLIGHT THE SHORT TERM FORECAST. THE 00 UTC DETERMINISTIC SUITE SUGGESTS THE CURRENT STRATUS DECK IN PLACE THIS MORNING ACROSS WESTERN AND CENTRAL NORTH DAKOTA WILL BEGIN TO CLEAR ACROSS THE FAR NORTH LATE THIS AFTERNOON. THE CLEARING TREND IS FORECAST TO CONTINUE TO PUSH SOUTH THROUGH THE EVENING AS THE SURFACE HIGH ACROSS WESTERN SASKATCHEWAN THIS MORNING PROPAGATES INTO WESTERN SOUTH DAKOTA FRIDAY MORNING. GIVEN COOL TEMPERATURES IN THE 40S AND LOWER 50S TO BEGIN THE EVENING...WIDESPREAD LOWS IN THE UPPER 20S AND LOWER 30S ARE EXPECTED ACROSS MUCH OF WESTERN AND CENTRAL NORTH DAKOTA TONIGHT WITH RADIATIONAL COOLING. THUS HAVE ISSUED A FREEZE WARNING FOR MUCH OF THE AREA LATE TONIGHT INTO FRIDAY MORNING..OUTSIDE OF THE JAMES RIVER VALLEY AND FAR SOUTH CENTRAL. FOR THESE AREAS...SUFFICIENT CLOUD COVER IS EXPECTED TO REMAIN THROUGH THE NIGHT TO KEEP LOWS ABOVE FREEZING. HOWEVER...A FROST ADVISORY MAY BE NEEDED WITH LATER UPDATES. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 346 AM CDT THU SEP 11 2014 A MEAN EASTERN PACIFIC/WESTERN U.S RIDGE AND CENTRAL/EASTERN U.S. TROUGH PATTERN IS EXPECTED TO CONTINUE THROUGH THE LONG TERM PERIOD. NORTHWEST FLOW OVER THE NORTHERN PLAINS WILL BRING A SERIES OF WEAK SHORTWAVES DOWN THE LEE OF THE CANADIAN ROCKIES AND INTO THE FORECAST AREA...KEEPING DAYTIME HIGH TEMPERATURES MAINLY IN THE 60S...WITH A THREAT OF PATCHY FROST EACH MORNING INTO EARLY NEXT WEEK. THE WESTERN RIDGE FINALLY TRANSLATES INLAND NEXT WEEK BRINGING UPPER LEVEL RIDGING AND WARMER TEMPERATURES...MAINLY 70S...TO THE FORECAST AREA NEXT TUESDAY THROUGH THURSDAY. COULD SEE AN ISOLATED SHOWER ALONG THE INTERNATIONAL BORDER SATURDAY EVENING...OTHERWISE DRY CONDITIONS ARE ANTICIPATED THROUGH THE EXTENDED PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1146 AM CDT THU SEP 11 2014 ISOLATED SHOWERS WILL DEVELOP OVER WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON. WILL ADD VCSH TO ALL TAF SITES AS A RESULT. IMPACTS TO SPECIFIC TERMINAL AERODROMES SHOULD BE BRIEF...IF ANY AT ALL. OTHERWISE...VFR CONDITIONS ARE EXPECTED THROUGH THE REMAINDER OF THE TAF PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING FROM 1 AM CDT /MIDNIGHT MDT/ TO 10 AM CDT /9 AM MDT/ FRIDAY FOR NDZ001>005-009>013-017>022-031>035-040>044. && $$ UPDATE...TM SHORT TERM...AYD LONG TERM...TWH AVIATION...TM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1006 AM CDT THU SEP 11 2014 .UPDATE... ISSUED AT 1006 AM CDT THU SEP 11 2014 CLOUDS ARE BEGINNING TO BREAK OVER WESTERN AND CENTRAL NORTH DAKOTA. TEMPERATURES ARE RESPONDING BY JUMPING INTO THE 40S WITHIN THE LAST HOUR. BOWMAN RADAR SHOWS ALL RETURNS SOUTH OF THE STATE. HOWEVER...MAINTAINED CHANCE OF LIGHT RAIN SOUTHWEST THROUGH THE THE MORNING AS A BAROCLINIC ZONE WILL BE IN THE VICINITY. ELSEWHERE...THE LATEST ARW AND NMM MESOSCALE MODELS PROG ISOLATED TO SCATTERED SHOWER ACTIVITY DEVELOPING SOUTHWEST OF THE MISSOURI RIVER THIS AFTERNOON. THE LATEST HRRR PROGS ISOLATED SHOWERS DEVELOPING CWA-WIDE THIS AFTERNOON. GIVEN THE PROXIMITY OF THE MOISTURE AND SUBTLE MUCAPE...WILL KEEP AFTERNOON POPS CONFINED TO AREAS SOUTHWEST OF THE MISSOURI RIVER...SIMILAR TO THE ARW AND NMM SOLUTIONS. AS A RESULT...CHANGED AFTERNOON WEATHER PRECIP TYPE WORDING FROM STRATIFORM RAIN TO CONVECTIVE SHOWERS. THE UPDATED PRODUCTS WILL BE OUT SHORTLY. UPDATE ISSUED AT 645 AM CDT THU SEP 11 2014 LATEST SATELLITE IMAGERY SHOWS UPPER LEVEL TROUGH DROPPING SOUTH THROUGH THE NORTHERN ROCKIES WITH STRONG JET EXTENDING FROM THE BASE OF THE TROUGH EAST INTO THE NORTHERN PLAINS. LATEST RADAR IMAGERY INDICATES THE MAJORITY OF THE PRECIPITATION REMAINING SOUTH OF THE FORECAST AREA...WITH FAR SOUTHWEST BOWMAN COUNTY SEEING SOME LIGHT RETURNS. MADE SOME MINOR ADJUSTMENTS TO POPS...CONFINING THEM TO THE FAR SOUTHWEST EARLY THIS MORNING. IF WE SEE SOME BREAKS IN THE CLOUDS TODAY...STRONG LOW LEVEL LAPSE RATES SHOULD AID IN SHOWER DEVELOPMENT FARTHER NORTH AND EAST. LATEST HRRR DEVELOPS ISOLATED CONVECTION ACROSS THE CWA BY THIS AFTERNOON. FOR NOW WILL KEEP POPS LIMITED TO THE SOUTHWEST QUARTER AS PREVIOUSLY FORECAST. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 346 AM CDT THU SEP 11 2014 FREEZING TEMPERATURES TONIGHT HIGHLIGHT THE SHORT TERM FORECAST. THE 00 UTC DETERMINISTIC SUITE SUGGESTS THE CURRENT STRATUS DECK IN PLACE THIS MORNING ACROSS WESTERN AND CENTRAL NORTH DAKOTA WILL BEGIN TO CLEAR ACROSS THE FAR NORTH LATE THIS AFTERNOON. THE CLEARING TREND IS FORECAST TO CONTINUE TO PUSH SOUTH THROUGH THE EVENING AS THE SURFACE HIGH ACROSS WESTERN SASKATCHEWAN THIS MORNING PROPAGATES INTO WESTERN SOUTH DAKOTA FRIDAY MORNING. GIVEN COOL TEMPERATURES IN THE 40S AND LOWER 50S TO BEGIN THE EVENING...WIDESPREAD LOWS IN THE UPPER 20S AND LOWER 30S ARE EXPECTED ACROSS MUCH OF WESTERN AND CENTRAL NORTH DAKOTA TONIGHT WITH RADIATIONAL COOLING. THUS HAVE ISSUED A FREEZE WARNING FOR MUCH OF THE AREA LATE TONIGHT INTO FRIDAY MORNING..OUTSIDE OF THE JAMES RIVER VALLEY AND FAR SOUTH CENTRAL. FOR THESE AREAS...SUFFICIENT CLOUD COVER IS EXPECTED TO REMAIN THROUGH THE NIGHT TO KEEP LOWS ABOVE FREEZING. HOWEVER...A FROST ADVISORY MAY BE NEEDED WITH LATER UPDATES. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 346 AM CDT THU SEP 11 2014 A MEAN EASTERN PACIFIC/WESTERN U.S RIDGE AND CENTRAL/EASTERN U.S. TROUGH PATTERN IS EXPECTED TO CONTINUE THROUGH THE LONG TERM PERIOD. NORTHWEST FLOW OVER THE NORTHERN PLAINS WILL BRING A SERIES OF WEAK SHORTWAVES DOWN THE LEE OF THE CANADIAN ROCKIES AND INTO THE FORECAST AREA...KEEPING DAYTIME HIGH TEMPERATURES MAINLY IN THE 60S...WITH A THREAT OF PATCHY FROST EACH MORNING INTO EARLY NEXT WEEK. THE WESTERN RIDGE FINALLY TRANSLATES INLAND NEXT WEEK BRINGING UPPER LEVEL RIDGING AND WARMER TEMPERATURES...MAINLY 70S...TO THE FORECAST AREA NEXT TUESDAY THROUGH THURSDAY. COULD SEE AN ISOLATED SHOWER ALONG THE INTERNATIONAL BORDER SATURDAY EVENING...OTHERWISE DRY CONDITIONS ARE ANTICIPATED THROUGH THE EXTENDED PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 645 AM CDT THU SEP 11 2014 GENERALLY VFR STRATUS WILL PERSIST THROUGH MORNING ACROSS WESTERN AND CENTRAL NORTH DAKOTA...BEFORE SLOWLY CLEARING FROM NORTH TO SOUTH LATE THIS AFTERNOON AND INTO THE EVENING. CANNOT RULE OUT A BRIEF PERIOD OF MVFR CONDITIONS IN STRATUS...WITH LIGHT RAIN POSSIBLY MIXED WITH SNOW THIS MORNING AT KDIK. && .BIS WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING FROM 1 AM CDT /MIDNIGHT MDT/ TO 10 AM CDT /9 AM MDT/ FRIDAY FOR NDZ001>005-009>013-017>022-031>035-040>044. && $$ UPDATE...TM SHORT TERM...AYD LONG TERM...TWH AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
645 AM CDT THU SEP 11 2014 .UPDATE... ISSUED AT 645 AM CDT THU SEP 11 2014 LATEST SATELLITE IMAGERY SHOWS UPPER LEVEL TROUGH DROPPING SOUTH THROUGH THE NORTHERN ROCKIES WITH STRONG JET EXTENDING FROM THE BASE OF THE TROUGH EAST INTO THE NORTHERN PLAINS. LATEST RADAR IMAGERY INDICATES THE MAJORITY OF THE PRECIPITATION REMAINING SOUTH OF THE FORECAST AREA...WITH FAR SOUTHWEST BOWMAN COUNTY SEEING SOME LIGHT RETURNS. MADE SOME MINOR ADJUSTMENTS TO POPS...CONFINING THEM TO THE FAR SOUTHWEST EARLY THIS MORNING. IF WE SEE SOME BREAKS IN THE CLOUDS TODAY...STRONG LOW LEVEL LAPSE RATES SHOULD AID IN SHOWER DEVELOPMENT FARTHER NORTH AND EAST. LATEST HRRR DEVELOPS ISOLATED CONVECTION ACROSS THE CWA BY THIS AFTERNOON. FOR NOW WILL KEEP POPS LIMITED TO THE SOUTHWEST QUARTER AS PREVIOUSLY FORECAST. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 346 AM CDT THU SEP 11 2014 FREEZING TEMPERATURES TONIGHT HIGHLIGHT THE SHORT TERM FORECAST. THE 00 UTC DETERMINISTIC SUITE SUGGESTS THE CURRENT STRATUS DECK IN PLACE THIS MORNING ACROSS WESTERN AND CENTRAL NORTH DAKOTA WILL BEGIN TO CLEAR ACROSS THE FAR NORTH LATE THIS AFTERNOON. THE CLEARING TREND IS FORECAST TO CONTINUE TO PUSH SOUTH THROUGH THE EVENING AS THE SURFACE HIGH ACROSS WESTERN SASKATCHEWAN THIS MORNING PROPAGATES INTO WESTERN SOUTH DAKOTA FRIDAY MORNING. GIVEN COOL TEMPERATURES IN THE 40S AND LOWER 50S TO BEGIN THE EVENING...WIDESPREAD LOWS IN THE UPPER 20S AND LOWER 30S ARE EXPECTED ACROSS MUCH OF WESTERN AND CENTRAL NORTH DAKOTA TONIGHT WITH RADIATIONAL COOLING. THUS HAVE ISSUED A FREEZE WARNING FOR MUCH OF THE AREA LATE TONIGHT INTO FRIDAY MORNING..OUTSIDE OF THE JAMES RIVER VALLEY AND FAR SOUTH CENTRAL. FOR THESE AREAS...SUFFICIENT CLOUD COVER IS EXPECTED TO REMAIN THROUGH THE NIGHT TO KEEP LOWS ABOVE FREEZING. HOWEVER...A FROST ADVISORY MAY BE NEEDED WITH LATER UPDATES. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 346 AM CDT THU SEP 11 2014 A MEAN EASTERN PACIFIC/WESTERN U.S RIDGE AND CENTRAL/EASTERN U.S. TROUGH PATTERN IS EXPECTED TO CONTINUE THROUGH THE LONG TERM PERIOD. NORTHWEST FLOW OVER THE NORTHERN PLAINS WILL BRING A SERIES OF WEAK SHORTWAVES DOWN THE LEE OF THE CANADIAN ROCKIES AND INTO THE FORECAST AREA...KEEPING DAYTIME HIGH TEMPERATURES MAINLY IN THE 60S...WITH A THREAT OF PATCHY FROST EACH MORNING INTO EARLY NEXT WEEK. THE WESTERN RIDGE FINALLY TRANSLATES INLAND NEXT WEEK BRINGING UPPER LEVEL RIDGING AND WARMER TEMPERATURES...MAINLY 70S...TO THE FORECAST AREA NEXT TUESDAY THROUGH THURSDAY. COULD SEE AN ISOLATED SHOWER ALONG THE INTERNATIONAL BORDER SATURDAY EVENING...OTHERWISE DRY CONDITIONS ARE ANTICIPATED THROUGH THE EXTENDED PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 645 AM CDT THU SEP 11 2014 GENERALLY VFR STRATUS WILL PERSIST THROUGH MORNING ACROSS WESTERN AND CENTRAL NORTH DAKOTA...BEFORE SLOWLY CLEARING FROM NORTH TO SOUTH LATE THIS AFTERNOON AND INTO THE EVENING. CANNOT RULE OUT A BRIEF PERIOD OF MVFR CONDITIONS IN STRATUS...WITH LIGHT RAIN POSSIBLY MIXED WITH SNOW THIS MORNING AT KDIK. && .BIS WATCHES/WARNINGS/ADVISORIES... FREEZE WARNING FROM 1 AM CDT /MIDNIGHT MDT/ TO 10 AM CDT /9 AM MDT/ FRIDAY FOR NDZ001>005-009>013-017>022-031>035-040>044. && $$ UPDATE...TWH SHORT TERM...AYD LONG TERM...TWH AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1251 AM CDT THU SEP 11 2014 .UPDATE... ISSUED AT 1249 AM CDT THU SEP 11 2014 NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE. THE BEST CHANCE FOR PRECIPITATION THE REMAINDER OF THE NIGHT IS ACROSS THE FAR SOUTHWEST IN ASSOCIATION WITH THE UPPER LEVEL LOW ACROSS CENTRAL MONTANA THAT WILL CONTINUE TO PROPAGATE SOUTHEAST THROUGH THE NIGHT. LIGHT SNOW MAY MIX WITH RAIN SOUTHWEST...HOWEVER NO ACCUMULATIONS ARE EXPECTED. GIVEN CLOUD COVER...MAY CANCEL THE FROST ADVISORY ACROSS THE TURTLE MOUNTAINS AREA THIS MORNING...FOCUSING ANY FROST AND FREEZE HEADLINES FOR THURSDAY NIGHT INTO FRIDAY MORNING WITH THE NEXT UPDATE. UPDATE ISSUED AT 912 PM CDT WED SEP 10 2014 LATEST WATER VAPOR IMAGERY SHOWS A SHORTWAVE ROTATING THROUGH SOUTHWEST NORTH DAKOTA. UPWARD VERTICAL MOTION ASSOCIATED WITH THIS SHORTWAVE ALONG WITH THE LEFT EXIT REGION OF AN UPPER JET ACROSS SOUTHERN NORTH DAKOTA IS PRODUCING SCATTERED RAIN SHOWERS...WITH AN ISOLATED/BRIEF PERIOD OF SLEET WITHIN THE STRONGEST VERTICAL MOTION FIELD. THIS WILL CONTINUE TO MOVE INTO THE JAMES RIVER VALLEY THROUGH THIS LATE EVENING. OTHERWISE...THE NEXT AREA OF PRECIPITATION WITH FORCING MECHANISMS VERY SIMILAR TO WHAT WAS MENTIONED ABOVE...IS PROPAGATING THROUGH SOUTHERN/SOUTHEASTERN MONTANA AT THIS TIME. THE HIGHEST POPS/LIKELY CATEGORY...WILL JUST GRAZE THE FAR SOUTHWEST PER NAM/RAP OVERNIGHT. SCATTERED RAIN SHOWERS SEEMS MORE APPROPRIATE...WITH SOME SNOW POSSIBLY MIXED IN AT TIMES. DEWPOINTS IN THE TURTLE MOUNTAINS HAVE NOW RISEN INTO THE LOWER 30S. DESPITE SOME CLEARING FROM TIME TO TIME...SATELLITE IMAGERY AND SURFACE OBS STILL INDICATE ENOUGH CLOUD COVER UPSTREAM TO KEEP TEMPERATURES ABOVE FREEZING OVERNIGHT. BELIEVE THE FROST ADVISORY IS IN GOOD STANDING AND WILL NOT MAKE ANY CHANGES AT THIS TIME. UPDATE ISSUED AT 618 PM CDT WED SEP 10 2014 THE LATEST VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS SHOW A CLOUDY SKY ACROSS WESTERN AND CENTRAL NORTH DAKOTA WITH THE EXCEPTION OF RUGBY AND ROLLA WHERE A STRONGER NORTHEAST FLOW IS ERODING A CLOUD SHIELD ADVANCING EAST FROM WESTERN NORTH DAKOTA. THERE ARE MORE HOLES IN THE OVERCAST CONDITIONS ACROSS SOUTHEAST SASKATCHEWAN AND WESTERN MANITOBA. THE CURRENT FROST ADVISORY AREA LOOKS ON TRACK AT THIS TIME. WILL MONITOR FOR ADDITIONAL CLEARING FARTHER WEST AND SEE HOW TEMPERATURES REACT THIS EVENING...GIVEN DEWPOINTS ARE IN THE UPPER 20S IN THE TURTLE MOUNTAINS. THIS COULD BECOME A BIGGER CONCERN WITH COLDER LOW TEMPERATURES IF THE SKY GRID TRENDS CLEARER THAN EXPECTED WITH A CONTINUED NORTHEAST WIND. HOWEVER AT THIS TIME...FEEL ENOUGH CLOUDS UPSTREAM WILL NEGATE A POTENTIAL FREEZE WARNING IN THE NORTHEAST...BUT WILL MONITOR THIS EVENING. REPORTS OF SOME SNOW MIXED IN WITH THE RAIN AT BEACH LATE THIS AFTERNOON...ALSO AT NEW ENGLAND AND IN AMIDON. SURFACE TEMPERATURE ROUGHLY AT 36F FOR THIS MIX TO OCCUR. THIS IS ASSOCIATED WITH A SHORTWAVE EJECTING OUT OF THE WEST. NORTHEAST WINDS IN CENTRAL NORTH DAKOTA CONTINUE TO ERODE THE LEADING EDGE OF THIS AREA SHOWERS. HOWEVER...AN ISOLATED MENTION FROM BISMARCK/MANDAN EAST INTO THE SOUTHERN JAMES RIVER VALLEY IS WARRANTED PER CURRENT REFLECTIVITY`S AND HIGH RESOLUTION SOLUTIONS OF THE HRRR AND RAP WHICH SLIDES A WEAK AREA THROUGH THIS EVENING. MINOR ADJUSTMENTS TO TEMPERATURES AND DEWPOINTS AS WELL AS POPS THIS EVENING. REST OF FORECAST REMAINS ON TRACK. UPDATE ISSUED AT 437 PM CDT WED SEP 10 2014 QUICK UPDATE TO EXPAND AN ISOLATED MENTION OF RAIN SHOWERS THROUGH SOUTH CENTRAL NORTH DAKOTA THIS EVENING. LATEST BISMARCK AND BOWMAN RADARS SHOWING AN AREA OF LIGHT RAIN SHOWERS MOVING EAST OUT OF THE SOUTHWEST. A MID LEVEL CIRCULATION LOCATED IN THE WEST WILL SLIDE EAST EARLY THIS EVENING...AND CONCUR WITH HIGHER RESOLUTION MODELS OF THE RAP AND HRRR...THIS PRECIPITATION WEAKENS BUT ALSO EXPANDS INTO SOUTH CENTRAL NORTH DAKOTA INCLUDING THE SOUTHERN JAMES RIVER VALLEY BETWEEN 00Z AND 03Z. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 255 PM CDT WED SEP 10 2014 THE MAJOR FORECAST CHALLENGE WILL BE THE FROST POTENTIAL TONIGHT. THE LATEST SHORT RANGE MODEL GUIDANCE CONTINUES TO PROG BOUNDARY LAYER MOISTURE TO ERODE TO THE SOUTHWEST AS DRIER AIR GETS USHERED IN FROM THE NORTHEAST. FURTHERMORE...BOUNDARY LAYER WINDS ARE FORECAST TO WEAKEN TO AROUND 10 KNOTS TONIGHT AS HIGH PRESSURE SETTLES INTO MONTANA. HOWEVER...THE LATEST GUIDANCE CONTINUES TO PROG MID-LEVEL MOISTURE/CLOUDS (USING 850MB-500MB LAYER RH FIELDS) TO STREAM OVER MOST OF WESTERN AND CENTRAL NORTH DAKOTA TONIGHT AHEAD OF A SHORTWAVE ROTATING INTO MONTANA. THIS WOULD LIKELY INHIBIT COOLING TEMPERATURES. BALANCING WHERE THE CLEARING SKIES ARE FORECAST...WINDS WEAKENING OVERNIGHT...AND BOUNDARY LAYER TEMPERATURES...THINK THE TURTLE MOUNTAIN AREA WILL HAVE THE BEST CHANCE OF SEEING A FROST BETWEEN 09Z-14Z THURSDAY MORNING. AS A RESULT...ISSUED A FROST ADVISORY FOR BOTTINEAU...ROLETTE...AND PIERCE COUNTIES FOR SAID TIME PERIOD. TO THE SOUTHWEST...THERE WILL BE A CHANCE FOR A RAIN/SNOW MIX AFTER MIDNIGHT. HOWEVER...ACCUMULATIONS SHOULD BE LIGHT. FOR THURSDAY...DEEP MOISTURE AND ASSOCIATED PRECIP CHANCES WILL CONTINUE TO PUSH SOUTH OF THE STATE AS HIGH PRESSURE BUILDS INTO THE REGION. WELL BELOW NORMAL HIGHS ARE EXPECTED ONCE AGAIN WITH READINGS RANGING FROM THE MID 40S SOUTHWEST TO THE MID 50S EAST. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 255 PM CDT WED SEP 10 2014 FOCUS IN THE LONG TERM WILL BE ON THE POTENTIAL FOR WIDESPREAD FROST AND A FREEZE FRIDAY MORNING. MODEL GUIDANCE CONTINUES TO SHOW LOWS IN THE UPPER 20S ACROSS THE WEST AND LOWER 30S ELSEWHERE. WITH A LARGE SURFACE HIGH OVER THE NORTHERN PLAINS WINDS WILL BE LIGHT. THE BIGGEST QUESTION WILL BE HOW FAST CLOUDS CLEAR OUT. DEEP MOISTURE ACROSS THE STATE WILL BEGIN TO CLEAR OUT QUICKLY AROUND 18 UTC THURSDAY...HOWEVER THE 12 UTC MODEL GUIDANCE SHOWS A THIN LAYER OF LOW TO MID LEVEL MOISTURE HANGING AROUND THROUGH 06 UTC FRIDAY. REGARDLESS AT LEAST PATCHY FROST SEEMS LIKELY ACROSS CENTRAL AND WESTERN NORTH DAKOTA. WIDESPREAD FROST IS LOOKING THE MOST LIKELY ACROSS THE NORTHWEST AS CLOUD COVER WILL CLEAR FROM NORTH TO SOUTH. THE NORTH WILL ALSO HAVE THE BEST OPPORTUNITY FOR A FREEZE AS LOWS WILL MOSTLY BE BELOW FREEZING...ESPECIALLY NORTHWEST. AS FOR THE SOUTH HAVE LIMITED THE WORDING FOR FROST AT AREAS FOR NOW AS CLOUD COVER MAY STICK AROUND LONG ENOUGH TO PREVENT WIDESPREAD FROST DEVELOPMENT. FOR THE SAME REASON THERE IS LESS OF A CHANCE OF A FREEZE ACROSS THE SOUTH. TEMPERATURES WILL ALSO DROP LOW ENOUGH ON SATURDAY MORNING ACROSS THE SOUTH...ESPECIALLY FOR THE SOUTHWEST...FOR SOME PATCHY FROST. FOR THE REMAINDER OF THE LONG TERM THE 12 UTC MODEL GUIDANCE CONTINUES TO SHOW A MEAN TROUGH OVER THE U.S. THE 12 UTC GFS AND ECMWF SHOW ANOTHER SHORT WAVE RIDING DOWN THE LEE OF THE CANADIAN ROCKIES INTO THE NORTHERN PLAINS LATE SATURDAY INTO SUNDAY. MODELS ARE NOT SHOWING MUCH PRECIPITATION WITH THIS SYSTEM AND THE REMAINDER OF THE LONG TERM IS ALSO LOOKING MOSTLY DRY AND WARMER. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1250 AM CDT THU SEP 11 2014 MVFR CEILINGS AT KDIK WILL CONTINUE THROUGH THE NIGHT...WITH SCATTERED LIGHT RAIN SHOWERS POSSIBLY MIXED WITH SNOW. OTHERWISE GENERALLY VFR STRATUS WILL PERSIST THROUGH THE NIGHT AND THROUGH THE MORNING ACROSS WESTERN AND CENTRAL NORTH DAKOTA...BEFORE SLOWLY CLEARING FROM NORTH TO SOUTH LATE THIS AFTERNOON AND INTO THE EVENING. && .BIS WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY FROM 4 AM TO 9 AM CDT THIS MORNING FOR NDZ004-005- 013. && $$ UPDATE...AYD SHORT TERM...TM LONG TERM...MM AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1143 PM CDT WED SEP 10 2014 .UPDATE... ISSUED AT 1143 PM CDT WED SEP 10 2014 TWEAKED TEMPS A BIT BUT WILL KEEP THE FROST HEADLINES GOING. A FEW SPOTS IN THE EASTERN COUNTIES HAVE ALREADY DROPPED INTO THE 30S BUT WITH INCREASING CLOUDS THAT SHOULD SLOW DOWN A BIT. NORTHWESTERN COUNTIES MAY NOT MAKE ADVISORY CRITERIA BUT WITH THE POSSIBILITY OF A FEW BREAKS IN THE CLOUDS AM RELUCTANT TO END IT EARLY. BUMPED UP POPS IN THE FAR SOUTHWEST AS THERE HAVE BEEN SOME DECENT RADAR RETURNS ALTHOUGH REPORTS OF RAIN REACHING THE GROUND HAVE BEEN HIT OR MISS. UPDATE ISSUED AT 947 PM CDT WED SEP 10 2014 TEMPS CONTINUE TO BE THE MAIN QUESTION. MOST LOCATIONS HAVE STAYED IN THE 40S...ALTHOUGH FOSSTON HAS DROPPED DOWN TO 37 WITH LESS CLOUD COVER IN THAT AREA AND THAT SITES TYPICAL COLD BIAS. DEW POINTS EARLIER THIS EVENING WERE IN THE UPPER 20S IN SOME SPOTS...BUT THERE HAS BEEN AN UPWARD TREND AND CLOUDS CONTINUE TO INCREASE FROM THE WEST. THERE COULD BE SOME BREAKS IN THE CLOUDS AND LIGHT ENOUGH WINDS TO DROP A FEW SPOTS INTO THE MID TO LOW 30S. THE DEW POINTS ARE LOWEST IN THE NORTHWESTERN COUNTIES BUT THE CLOUD COVER IS LESS IN THE NORTHEAST...SO THESE AREAS CONTINUE TO BE MOST LIKELY TO SEE THE LOW TEMPERATURES. WILL KEEP THE FROST ADVISORY GOING FOR NOW. DOWN OVER THE SOUTHWESTERN COUNTIES...RADAR RETURNS HAVE BEEN ENTERING THE AREA AS A WEAK SHORTWAVE PASSES THROUGH. NOT TOO MUCH REACHING THE GROUND SO WILL KEEP POPS IN THE 20-30 PERCENT RANGE. THE PRECIP SHOULD TAPER OFF AFTER MIDNIGHT. UPDATE ISSUED AT 645 PM CDT WED SEP 10 2014 MADE A FEW MINOR TWEAKS TO POPS AS SHORT RANGE MODELS LIKE THE HRRR AND THE RAP TREND TOWARDS BRINGING SOME SHOWERS FROM SOUTHWESTERN ND INTO OUR FAR SOUTHWESTERN COUNTIES. NOT HUGELY IMPRESSED WITH SIGNIFICANT PRECIP CHANCES...BUT INCLUDED A ISOLATED MENTION IN THE FAR SOUTHWEST IN CASE SOME SPRINKLES MOVE INTO RANSOM OR SARGENT COUNTIES. WILL HOLD ONTO FROST HEADLINES AND CURRENT TEMPS FOR NOW AND TAKE A SECOND LOOK ONCE THE SUN SETS. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 258 PM CDT WED SEP 10 2014 MAIN FORECAST CHALLENGE WILL BE FROST POTENTIAL THE NEXT FEW NIGHTS. AS OF MID AFTERNOON SEEING MORE SUN THAN HAD EARLIER ANTICIPATED. BASICALLY SEEING WEST TO EAST MID LEVEL FLOW WITH SOME MID LEVEL CLOUDS DRIFTING OVER THE FA. MEANWHILE DRY NORTHEAST WINDS CONTINUE TO ERODE THE LOWER CLOUDS OVER PORTIONS OF THE NORTHERN AND EASTERN FA. WINDS ARE STILL PRETTY GUSTY BUT THESE SHOULD BEGIN TO DECREASE THRU THE EVENING. SHOULD SEE THE MOST DECREASE IN WINDS LATE...THEREFORE MUCH OF THIS FORECAST HINGES ON CLOUD COVER. THINK THAT THERE WILL BE SOME CLOUD COVER OVER THE AREA TONIGHT AND MAYBE MORE SO ACROSS THE SOUTH. WITH TEMPS ALREADY SO COOL THINK THAT ALL IT WILL TAKE IS AN HOUR OR SO WITH NO CLOUDS FOR TEMPS TO QUICKLY PLUMMET. THEREFORE DROPPED LOWS A FEW MORE DEGREES IN THE EAST TO GO ALONG WITH THE EXPECTED COOLER TEMPS IN THE NORTHWEST. WILL GO WITH A FROST ADVISORY FOR BOTH AREAS...ESSENTIALLY THE NORTHWEST EDGE OF THE FA AND THE EASTERN EDGE. IN BETWEEN MAY BE CLOSE AND WILL LET THE EVENING SHIFT KEEP AN EYE ON THAT. SEEMS LIKE WE TRADITIONALLY MISS THE FIRST FROST BECAUSE IT IS SO SPOTTY. THIS MAY BE THE CASE THIS TIME TOO...WITH SOME COLD SPOTS AND FROST WITH SOME WARMER SPOTS CLOSE BY. WILL CONTINUE TO SEE THE WESTERLY MID LEVEL FLOW ON THU SO WILL STICK WITH MORE CLOUDS TO THE SOUTH AND LESS NORTH...BUT AGAIN A TOUGH CALL. MORE OF THE AREA WILL PROBABLY BE UNDER THE GUN THU NIGHT BUT THINK AREAS ALONG AND NORTH OF HIGHWAY 2 MAY HAVE THE BEST CHANCE OF FROST. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 258 PM CDT WED SEP 10 2014 SFC HIGH WILL DRIFT SOUTH OF THE AREA FOR FRI INTO SAT. THERE MAY STILL BE SOME FROST POSSIBLE FRI NIGHT BUT RETURN SOUTH-SW FLOW WILL DEVELOP. THEREFORE WIND AND CLOUDS WILL REMAIN THE MAIN CHALLENGE. KEPT A DRY FORECAST SAT ALTHOUGH SEVERAL MODELS SHOW ANOTHER SFC LOW IN THE NORTHWEST FA WITH A LITTLE LIGHT PCPN AROUND IT. LONG TERM MODELS IN SIMILAR AGREEMENT WITH UPPER WAVE EXTENDING ACROSS S CNTRL CANADA SUN NIGHT...AND POSITION OF SFC HIGH IN MUCH BETTER AGREEMENT (THAN YESTERDAYS 12Z RUNS) BETWEEN THE GFS/ECMWF. BOTH MODELS INDICATING MOSTLY DRY WX AS SFC FRONT MOVES ACROSS MB AND CLIPS THE NORTHERN VALLEY. CONSALL DOES SHOW LOW POPS OVER NORTHEAST AS BOTH MODELS HAVE PRECIP OVER NE MN SAT NIGHT. SFC HIGH THEN DOMINATES AREA FOR MON AND TUE OF NEXT WEEK AS DRY AND COOL WX CONTINUES. RETURN FLOW SETS UP ON TUE...CAUSING A MILD WARMING TREND BUT DID REMOVE SPOTTY LOW POPS PRODUCED BY CONSALL AS BOTH GFS AND ECMWF ARE DRY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1143 PM CDT WED SEP 10 2014 VFR CONDITIONS WILL CONTINUE THROUGHOUT THE PERIOD WITH MID AND HIGH LEVEL CLOUDS. TOMORROW THE CIGS COULD DROP TO THE LOWER END OF VFR BUT ARE NOT EXPECTED TO GO ANY LOWER. NORTH WINDS WILL CONTINUE BUT SHOULD BE UNDER 12 KTS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...FROST ADVISORY FROM 4 AM TO 9 AM CDT THURSDAY FOR NDZ006-007-014. MN...FROST ADVISORY FROM 4 AM TO 9 AM CDT THURSDAY FOR MNZ005-006-008- 009-013>017-023-024. && $$ UPDATE...JR SHORT TERM...GODON LONG TERM...GODON/SPEICHER AVIATION...JR
AREA FORECAST DISCUSSION
NWS TULSA OK
1154 PM CDT WED SEP 10 2014 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE TO BE POSSIBLE ACROSS MAINLY SOUTHEAST OKLAHOMA AND NORTHWEST ARKANSAS TONIGHT INTO THURSDAY MORNING AS A COLD FRONT MOVES THROUGH. BEHIND THE FRONT...MVFR TO POSSIBLE PERIODS OF IFR CEILINGS ARE EXPECTED TO OVERSPREAD THE REGION AND REMAIN INTO THE AFTERNOON HOURS. PARTS OF NORTHEAST OKLAHOMA INTO FAR NORTHWEST ARKANSAS COULD LIFT BACK TO VFR FOR A FEW HOURS BUT THEN DROP BACK TO MVFR THURSDAY EVENING. PRECIP CHANCES WILL AGAIN BE POSSIBLE THURSDAY AFTERNOON AND EVENING AND WILL CARRY PROB30 GROUPS FOR MLC/FSM AND HOLD OFF FOR NOW ON ADDITIONAL PRECIP MENTIONS ELSEWHERE. && .PREV DISCUSSION... /ISSUED 911 PM CDT WED SEP 10 2014/ ..UPDATE... DISCUSSION... OUN SOUNDING CONTINUES TO SHOW RELATIVELY MOIST SOUTHWEST WINDS ABOVE THE FRONT. THIS COULD SUPPORT ELEVATED PRECIPITATION AND CONVECTION THROUGH THE NIGHT. RAP AND HRRR APPARENTLY SEE THIS AND ALSO DEVELOP PRECIPITATION LATER IN THE NIGHT. BEST BET IS AGAIN OVER WEST CENTRAL ARKANSAS INTO SOUTHEAST OKLAHOMA...GENERALLY ALONG AND SOUTH OF I-40. LOWER CHANCES WILL EXTEND NORTHWARD...BUT NOT ALL THE WAY TO THE KANSAS BORDER. WILL KEEP CHANCES IN THE FORECAST FOR FAR NORTHWEST ARKANSAS ALSO. LIGHT SHOWERS MOVING ACROSS PARTS OF NORTHEAST OK NOW. OTHER SHOWERS AND ISOLATED THUNDERSTORM REDEVELOPING ALONG I-40 FROM CHECOTAH TO THE WEST OF OKEMAH. && .PRELIMINARY POINT TEMPS/POPS... TUL 61 76 61 65 / 40 10 30 50 FSM 70 75 66 71 / 70 50 50 70 MLC 66 75 66 68 / 70 50 60 60 BVO 58 74 58 66 / 20 10 20 40 FYV 63 73 60 67 / 60 40 40 60 BYV 62 72 58 66 / 60 30 40 50 MKO 63 77 63 66 / 50 20 40 60 MIO 59 73 57 66 / 20 10 20 40 F10 63 76 62 65 / 50 20 40 60 HHW 71 80 69 74 / 60 60 70 60 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ AVIATION...20
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
401 PM EDT THU SEP 11 2014 .SYNOPSIS... A STRONG COLD WILL MOVE ACROSS THE REGION TODAY. COOL AND DRIER WEATHER WILL FOLLOW FOR FRIDAY. A NEW DISTURBANCE WILL MOVE THROUGH THE AREA ON SATURDAY BEFORE HIGH PRESSURE RETURNS FAIR WEATHER FOR SUNDAY. THE OVERALL PATTERN FAVORS BELOW NORMAL TEMPERATURES FROM SATURDAY INTO NEXT WEEK. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... 2PM UPDATE... AS OF 2PM...THE COLD FRONT IS BETWEEN STATE COLLEGE AND ALTOONA WITH EVEN FEWER SHOWERS ASSOCIATED THAN EARLIER THIS MORNING. THE UPPER SHORTWAVE IS VERY FLAT AND SHEARED OUT...SO SUPPORT FOR THE FRONT IS NOT IMPRESSIVE EVEN THOUGH THE AIRMASS DISCONTINUITY IS. TEMPERATURES HAVE BEEN STEADY OR FALLING OVER NWRN PA ALL DAY WHILE TEMPS HAVE RISEN INTO THE LOWER 80S OVER THE SERN PART OF THE AREA. THE RAP SHOWS VIRTUALLY NO CAPE OR LOW LEVEL CONVERGENCE ALONG WITH WEAK MID LEVEL LAPSE RATES...AND THE LACK OF SHOWER ACTIVITY PRETTY MUCH CONFIRMS THIS ANALYZED LACK OF INSTABILITY. I LOWERED THE OVERALL PROBABILITY OF SHOWERS AND ISOLATED THUNDERSTORMS OVER MY SERN ZONES AS THE FRONT SWEEPS EAST. THE NEXT 3-6 HOURS WILL BE THE WINDOW OF BEST OPPORTUNITY FOR RAIN BEFORE THINGS DRY OUT FOR TONIGHT AND FRIDAY. THE FRONT WILL PUSH SE OF THE AREA THIS EVENING WITH AN INITIALLY GUSTY NW FLOW GIVING WAY TO A LIGHTER BREEZE. MODEL SOUNDINGS SHOW A FAIR AMOUNT OF LOW LEVEL MOISTURE BEING TRAPPED UNDER A STRENGTHENING SUBSIDENCE INVERSION. LOOKS LIKE LOW CLOUDS AND EVEN SOME PATCHY FOG WILL REDEVELOP LATER TONIGHT...LASTING THROUGH THE SUNRISE HOURS OF FRIDAY. LOWS TONIGHT WILL DIP INTO THE LOW-MID 40S IN VALLEYS OF THE NORTHERN MOUNTAINS TO NEAR 60 IN THE SE. IF CLOUDS HOLD OFF OR BREAK UP...WOULD NOT BE SURPRISED TO SEE SOME READINGS IN THE UPPER 30S AT SOME OF THE NORMAL COLD SPOTS OF THE NORTH. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... IT WILL BE DRY FRIDAY BUT IT COULD BE RATHER CLOUDY FOR A TIME UNTIL THE SUBSIDENCE INVERSION MIXES OUT AND CLOUDS CAN BREAK UP. HIGHS IN THE 60S TO LOWER 70S WILL AVERAGE SOME 5-10 DEG BELOW NORMAL. && .LONG TERM /SATURDAY THROUGH THURSDAY/... A SHORTWAVE TROUGH DIGGING SEWD THROUGH THE NRN HIGH PLAINS THIS MORNING WILL MOVE EASTWARD AND REACH THE GRT LAKES REGION FRI NIGHT WHILE CONTINUING TO AMPLIFY...TAKING ON A NEGATIVE TILT AS IT ACCELERATES NEWD ACROSS THE ST LAWRENCE RIVER VLY ON SAT. THE ENERGY WILL BE IN SUFFICIENTLY CLOSE PROXIMITY TO THE BAROCLINIC ZONE OVER THE SOUTHEAST STATES FOR A WAVE OF LOW PRESSURE TO DEVELOP NEAR THE TN VLY/CNTRL APPLCHNS AND LIFT NEWD THRU UPPER OH VLY/MID ATLC/NORTHEAST ON SAT. MODEST HEIGHT FALLS AND FAVORABLE JET DYNAMICS ALOFT SHOULD PROVIDE SUFFICIENT LG SCALE FORCING FOR LIFT...WHILE STRENGTHENING SLY LLJ/WAA RECOVERS PW VALUES TO 1-1.5 INCHES. MODELS SHOW LITTLE IN THE WAY OF INSTABILITY BUT SOME LOW TOPPED CONVECTION MAY STILL DEVELOP AND PRODUCE LOCAL 0.25 TO 0.50 QPF AMTS. THE TRAILING FRONT SHOULD BE FAIRLY PROGRESSIVE AS IT CROSSES THRU THE LOCAL AREA..WHICH SHOULD ALSO ACT TO LIMIT PCPN AMTS. WITH GOOD AGREEMENT IN THE GUIDANCE OPTED TO INCREASE AREA OF LKLY POPS FOR D3. FROM SUNDAY TO NEXT THURSDAY (9/18) THE UPPER PATTERN OVER NOAM WILL FEATURE A WESTERN RIDGE WITH A DOWNSTREAM MEAN TROUGH OVER THE EAST. WHILE MOST OF THE PERIOD SHOULD BE DRY UNDER THE INFLUENCE OF MODIFIED CANADIAN HIGH PRESSURE...THERE SEEMS TO BE BROAD SUPPORT FOR ANOTHER S/WV AND FRONTAL SYSTEM TO BRING SHOWERS TO THE AREA IN THE LATE MONDAY/TUESDAY TIME FRAME. OTHERWISE MOST OF THE ORGANIZED PCPN WILL BE FOCUSED TO THE SOUTH NEAR STALLED FRONT OVER THE CAROLINAS. THE MEAN PATTERN SUPPORTS BELOW AVG FALL-LIKE READINGS WITH A FEW CHILLY MORNINGS AND COOL DAYS. SOME PATCHY FROST IS POSSIBLE IN THE NRN TIER WHICH IS NOT THAT FAR FROM THE CLIMO. && .AVIATION /19Z THURSDAY THROUGH TUESDAY/... A COLD FRONT IS MOVING THROUGH THE FLYING AREA. CEILINGS HAVE LIFTED UP TO VFR FOR THE MOST PART IN THE WARM AIR AHEAD OF THE FRONT...WHILE BEHIND THE FRONT MVFR AND EVEN AREAS OF IFR ARE FAIRLY WIDESPREAD IN A PATTERN THAT MORE RESEMBLES THE COLD SEASON THAN THE LATE SUMMER. THESE LOWER CEILINGS WILL TEND TO LIFT THROUGH EARLY EVENING WITH MOST SITES BEING VFR BY NIGHTFALL. JST- BFD ARE USUALLY THE TERMINALS THAT HANG ON TO LOWER CONDITIONS THE LONGEST AND THIS SHOULD NOT BE AN EXCEPTION. THERE IS STILL THE POTENTIAL FOR AN ISOLATED HEAVIER SHOWER OR THUNDERSTORM...WITH LOCALIZED BRIEF FLIGHT RESTRICTIONS...OVER SERN AREAS AS THE FRONT SWEEPS EAST. THE THREAT WILL DIMINISH LATER THIS AFTERNOON INTO EARLY EVENING AS THE FRONT MOVES EAST OF THE AREA. FORECAST SOUNDINGS SHOW A STRONG LOW LEVEL INVERSION FORMING LATER TONIGHT AS A SPRAWLING HIGH PRESSURE AREA SPILLS INTO THE REGION. THIS SHOULD LEAD TO THE REDEVELOPMENT OF SOME LOW CLOUDS AND POSSIBLY AREAS OF FOG LATER TONIGHT THROUGH THE POST DAWN HOURS OF FRIDAY MORNING. OUTLOOK... FRI...LOW CIGS PSBL EARLY...BCMG VFR. SAT...VFR/MVFR CIGS WITH SCT SHOWERS. SUN...PATCHY AM FOG...OTHERWISE VFR. MON...NO SIG WX. MON NIGHT - TUE...A COLD FRONT WILL BRING REDUCED CONDITIONS WITH SHOWERS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...STEINBUGL AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
205 PM EDT THU SEP 11 2014 .SYNOPSIS... A STRONG COLD WILL MOVE ACROSS THE REGION TODAY. COOL AND DRIER WEATHER WILL FOLLOW FOR FRIDAY. A NEW DISTURBANCE WILL MOVE THROUGH THE AREA ON SATURDAY BEFORE HIGH PRESSURE RETURNS FAIR WEATHER FOR SUNDAY. THE OVERALL PATTERN FAVORS BELOW NORMAL TEMPERATURES FROM SATURDAY INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... 2PM UPDATE... AS OF 2PM...THE COLD FRONT IS BETWEEN STATE COLLEGE AND ALTOONA WITH EVEN FEWER SHOWERS ASSOCIATED THAN EARLIER THIS MORNING. THE UPPER SHORTWAVE IS VERY FLAT AND SHEARED OUT...SO SUPPORT FOR THE FRONT IS NOT IMPRESSIVE EVEN THOUGH THE AIRMASS DISCONTINUITY IS. TEMPERATURES HAVE BEEN STEADY OR FALLING OVER NWRN PA ALL DAY WHILE TEMPS HAVE RISEN INTO THE LOWER 80S OVER THE SERN PART OF THE AREA. THE RAP SHOWS VIRTUALLY NO CAPE OR LOW LEVEL CONVERGENCE ALONG WITH WEAK MID LEVEL LAPSE RATES...AND THE LACK OF SHOWER ACTIVITY PRETTY MUCH CONFIRMS THIS ANALYZED LACK OF INSTABILITY. I LOWERED THE OVERALL PROBABILITY OF SHOWERS AND ISOLATED THUNDERSTORMS OVER MY SERN ZONES AS THE FRONT SWEEPS EAST. THE NEXT 3-6 HOURS WILL BE THE WINDOW OF BEST OPPORTUNITY FOR RAIN BEFORE THINGS DRY OUT FOR TONIGHT AND FRIDAY. THE FRONT WILL PUSH SE OF THE AREA THIS EVENING WITH AN INITIALLY GUSTY NW FLOW GIVING WAY TO A LIGHTER BREEZE. MODEL SOUNDINGS SHOW A FAIR AMOUNT OF LOW LEVEL MOISTURE BEING TRAPPED UNDER A STRENGTHENING SUBSIDENCE INVERSION. LOOKS LIKE LOW CLOUDS AND EVEN SOME PATCHY FOG WILL REDEVELOP LATER TONIGHT...LASTING THROUGH THE SUNRISE HOURS OF FRIDAY. LOWS TONIGHT WILL DIP INTO THE LOW-MID 40S IN VALLEYS OF THE NORTHERN MOUNTAINS TO NEAR 60 IN THE SE. IF CLOUDS HOLD OFF OR BREAK UP...WOULD NOT BE SURPRISED TO SEE SOME READINGS IN THE UPPER 30S AT SOME OF THE NORMAL COLD SPOTS OF THE NORTH. && .SHORT TERM /FRIDAY/... IT WILL BE DRY FRIDAY BUT IT COULD BE RATHER CLOUDY FOR A TIME UNTIL THE SUBSIDENCE INVERSION MIXES OUT AND CLOUDS CAN BREAK UP. HIGHS IN THE 60S TO LOWER 70S WILL AVERAGE SOME 5-10 DEG BELOW NORMAL. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... SURFACE HIGH SPLITS FRI NIGHT/SAT WITH A PORTION RUNNING EASTWARD ACROSS S ONTARIO/NEW ENGLAND WHILE THE MAIN HIGH PRESSURE CENTER REMAINS CENTERED OVER MISSOURI VALLEY. AT THE SAME TIME...A POTENT UPPER SHORTWAVE SLIDES EAST ALONG THE U.S./CANADA BORDER TURNING LOW LEVEL FLOW OVER PA BACK TO THE SOUTH BRIEFLY FRI NIGHT INTO SAT. INCREASED LOW-MID LEVEL FLOW DURING THIS TIME SHOULD TRIGGER SCT SHOWERS...THOUGH ACCUMS SHOULD BE LIGHT WITH LIMITED MOISTURE TO WORK WITH. LEFT SUNDAY INTO WED DRY. SOME HINTS OF A WEAK TROUGH OVER THE LAKES EARLY NEXT WEEK...BUT LEFT FCST DRY FOR NOW. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... A COLD FRONT IS MOVING THROUGH THE FLYING AREA. CEILINGS HAVE LIFTED UP TO VFR FOR THE MOST PART IN THE WARM AIR AHEAD OF THE FRONT...WHILE BEHIND THE FRONT MVFR AND EVEN AREAS OF IFR ARE FAIRLY WIDESPREAD IN A PATTERN THAT MORE RESEMBLES THE COLD SEASON THAN THE LATE SUMMER. THESE LOWER CEILINGS WILL TEND TO LIFT THROUGH EARLY EVENING WITH MOST SITES BEING VFR BY NIGHTFALL. JST- BFD ARE USUALLY THE TERMINALS THAT HANG ON TO LOWER CONDITIONS THE LONGEST AND THIS SHOULD NOT BE AN EXCEPTION. THERE IS STILL THE POTENTIAL FOR AN ISOLATED HEAVIER SHOWER OR THUNDERSTORM...WITH LOCALIZED BRIEF FLIGHT RESTRICTIONS...OVER SERN AREAS AS THE FRONT SWEEPS EAST. THE THREAT WILL DIMINISH LATER THIS AFTERNOON INTO EARLY EVENING AS THE FRONT MOVES EAST OF THE AREA. FORECAST SOUNDINGS SHOW A STRONG LOW LEVEL INVERSION FORMING LATER TONIGHT AS A SPRAWLING HIGH PRESSURE AREA SPILLS INTO THE REGION. THIS SHOULD LEAD TO THE REDEVELOPMENT OF SOME LOW CLOUDS AND POSSIBLY AREAS OF FOG LATER TONIGHT THROUGH THE POST DAWN HOURS OF FRIDAY MORNING. OUTLOOK... FRI...LOW CIGS PSBL EARLY...BCMG VFR. SAT...VFR/MVFR CIGS WITH SCT SHOWERS. SUN...PATCHY AM FOG...OTHERWISE VFR. MON...NO SIG WX. MON NIGHT - TUE...A COLD FRONT WILL BRING REDUCED CONDITIONS WITH SHOWERS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...MARTIN AVIATION...LA CORTE
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1244 AM CDT THU SEP 11 2014 .UPDATE... AVIATION DISCUSSION HAS BEEN UPDATED. A QUICK MOVING SHORT WAVE TROUGH WAS BRINGING SOME LIGHT RAIN SHOWERS TO THE REGION THIS EVENING. THIS WILL MOVE ON TO THE EAST AFTER MIDNIGHT WHILE NEW DEVELOPMENT MOVES INTO THE WEST AND SOUTHWEST PARTS OF THE CWA WITH THE MAIN UPPER LOW PRESSURE TROUGH. ADJUSTED POPS FOR THE NIGHT...MAINLY ACROSS THE NORTHERN CWA. UPDATED FORECAST. && .PREVIOUS DISCUSSION... .SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT CLOUDY AND COLD IS THE STORY ACROSS THE REGION THIS AFTERNOON. IN FACT...SOME LOCATIONS WILL LIKELY SET RECORDS FOR THE COLDEST HIGH TEMPERATURE EVER RECORDED ON THIS DATE. CWA IS CURRENTLY DRY BUT WATCHING THE BEGINNINGS OF THE NEXT SYSTEM MOVING ACROSS NORTHWEST SD. TREND FOR TONIGHT WILL BE FOR PRECIP TO MAINLY AFFECT WESTERN AND CENTRAL SD...AND MAY EVEN GET COLD ENOUGH LATE TONIGHT AND EARLY THURSDAY MORNING TO ALLOW FOR A RAIN/SNOW MIX ACROSS THE FAR NORTHWEST CWA. TARGET AREA FOR ACCUMULATING SNOW THOUGH STILL REMAINS OVER FAR WESTERN SD AND THE BLACK HILLS. WILL HAVE TO WATCH CLOUD COVER TRENDS OVERNIGHT ACROSS THE NORTHERN/NORTHEAST CWA AS CIGS HAVE THINNED AND HAVE EVEN REVEALED SOME HOLES. RAP MODEL 925-850MB RH SHOWS THIS DRIER AREA NICELY...AND BRINGS IN OVER THE NORTHERN COUNTIES LATER TONIGHT. IF ANY BREAKS OR THINNING OCCUR...TEMPS COULD FALL PRETTY NICELY. BUT OVERALL...THE ABUNDANCE OF MID AND HIGH CLOUDS WITH THE NEXT APPROACHING WAVE...AND THE OVERALL WINDS STAYING UP A TOUCH SHOULD PREVENT THE BOTTOM FROM FALLING OUT ON TEMPS. ATTENTION THEN TURNS TO THURSDAY NIGHT AND FRIDAY MORNING AND THE POTENTIAL FOR FROST. MODELS CONTINUE TO SHIFT PRECIP AND CLOUDS A BIT FURTHER SOUTH AND EAST DURING THIS TIME...A BIT QUICKER THAN PREVIOUS RUNS...AND THE PREVIOUSLY SLOWER EC IS NOW COMING AROUND TO THE FASTER SOLUTIONS OTHER MODELS HAVE BEEN SHOWING. THIS MEANS A BETTER POTENTIAL FOR FROST CONDITIONS AND TEMPS IN THE LOW TO MID 30S OVER A GOOD PORTION OF THE CWA. INSERTED FROST INTO THE GRIDS ALONG AND WEST OF THE JAMES VALLEY AND COULD VERY WELL BE HEADING TOWARDS A FROST ADVISORY AT SOME POINT. IT WILL ALL DEPEND ON HOW MUCH CLOUD COVER LINGERS OVER THE AREA...THE CLEARER THE SKIES THE BETTER THE TEMPS WILL FALL. FOR FRIDAY NIGHT AND SATURDAY...MODELS SEEM TO BE NUDGING THE HIGH CENTER TO THE EAST A TAD QUICKER. WHAT THIS MEANS IS THAT A SLIGHTLY STRONGER GRADIENT SETS UP FRIDAY NIGHT WITH SOUTH WINDS PICKING UP. WHETHER OR NOT THESE WINDS ARE STRONG ENOUGH ALONG AND EAST OF THE JAMES VALLEY TO PREVENT TEMPS FROM REACHING THE LOW TO MID 30S IS DOUBTFUL. WEST OF THERE...PROBABLY YES. CANNOT RULE OUT FROST FRIDAY NIGHT/SATURDAY MORNING EITHER...BUT BEST POTENTIAL HERE WILL BE ACROSS THE EASTERN CWA. .LONG TERM...SATURDAY THROUGH WEDNESDAY NOT MUCH CHANGE IN THE EXTENDED FROM 24 HOURS AGO. 12Z MODEL SOLUTIONS POINT TO A BIT OF WARMING ON SATURDAY OUT AHEAD OF AN APPROACHING COLD FRONT. ANOTHER SURFACE HIGH PRESSURE SYSTEM BUILDS DOWN FOR SUNDAY AND MONDAY...BUT THEN SHIFTS SOUTH AND EAST OF THE AREA...ALLOWING FOR RETURN FLOW WARMING WINDS TUESDAY AND WEDNESDAY. PRECIPITATION CHANCES REALLY ARE FEW AND FAR BETWEEN IN THE OUT PERIODS...WITH THE "BEST" CHANCES FOR A FEW RAIN SHOWERS SHOWING UP SUNDAY AFTERNOON/EVENING BEHIND THIS COLD FROPA. && .AVIATION... 06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS A QUICK MOVING SHORT WAVE TROUGH WILL BRING SOME LIGHT RAIN SHOWERS TO ATY INTO THE EARLY MORNING HOURS. OTHERWISE...LIFT FROM THE MAIN UPPER LOW PRESSURE AREA DROPPING IN FROM THE NORTHWEST TONIGHT AND THURSDAY WILL BRING SHOWERS INTO THE PIERRE AREA THROUGH THURSDAY MORNING. EXPECT MOST OF THE SHOWERS TO REMAIN AWAY FROM MBG...ABR AND ATY. CEILINGS ARE EXPECTED TO BE MAINLY VFR FOR MBG ...ABR AND ATY THROUGH THE PERIOD...EXCEPT FOR PIR WHERE THEY SHOULD BE MAINLY MVFR. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...MOHR SHORT TERM...TMT LONG TERM...DORN AVIATION...TDK WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
725 PM CDT FRI SEP 12 2014 .UPDATE... LATEST SURFACE OBS AND SATELLITE IMAGERY SHOWS LOW CLOUDS CONTINUE TO BLANKET THE MID STATE...AND ACTUALLY EXTEND NORTHWARD ALL THE WAY INTO CANADA SO THEY WONT BE GOING ANYWHERE ANYTIME SOON. WATER VAPOR IMAGERY THIS EVENING DEPICTS A STRONG TROUGH DIGGING SOUTHWARD INTO IOWA AND MISSOURI. AS THIS TROUGH SWINGS THROUGH THE OHIO AND TENNESSEE VALLEYS OVERNIGHT...EXPECT A FEW LIGHT SHOWERS AND SPRINKLES TO BREAK OUT ACROSS THE MID STATE SIMILAR TO THE MOST RECENT HRRR MODEL RUNS. ALSO ANTICIPATE SOME PATCHY FOG DEVELOPMENT IN THE HIGHER TERRAIN AREAS OF EASTERN ZONES AS DEWPOINT DEPRESSIONS LOWER OVERNIGHT. DESPITE EXTENSIVE CLOUD COVER...CAA WILL INCREASE OVERNIGHT WITH DRIER AIR ADVECTING IN FROM THE NORTH AT THE SURFACE...WHICH SHOULD ALLOW TEMPS TO FALL INTO THE UPPER 50S AND LOWER 60S FOR LOWS. CURRENT FORECAST FOR TONIGHT ALREADY HAS CLOUDS...POPS...AND TEMPS WELL HANDLED...AND ONLY MADE MINOR CHANGES FOR THE OVERNIGHT PERIOD. SHAMBURGER && .PREV DISCUSSION... /ISSUED 514 PM CDT FRI SEP 12 2014/ AVIATION 00Z DISCUSSION... PVA WILL BE IN PLACE THROUGH 12Z OVERNIGHT AS A WEAK MID LEVEL IMPULSE WILL BE ON APPROACH. AS A RESULT...LOW CIGS WILL PERSIST THROUGH AT LEAST 12Z. THEREAFTER...THE LOW CLOUDINESS WILL STILL BE RATHER TOUGH TO DISLODGE. THE MID AND UPPER FLOW STILL CARRIES A WEAK SOUTHERLY COMPONENT. NEVERTHELESS...CIGS SHOULD BEGIN TO LIFT SOME TOWARD 18Z WITH PARTIAL CLEARING WEST BY 00Z. OTW...ISOLATED SHOWERS HERE AND THERE WILL BE POSSIBLE UNTIL 12Z. HOWEVER...THE EXPECTED COVERAGE DOES NOT WARRANT THE USAGE OF VCNTY...TEMPO OR PROB GROUPS. PREV DISCUSSION... /ISSUED 256 PM CDT FRI SEP 12 2014/ DISCUSSION...IT WAS A CLOUDY DAY ACROSS MID TN WITH TEMPERATURES MAINLY IN THE 70S...WHICH IS 5 TO 10 DEGREES COOLER THAN NORMAL. A COLD FRONT HAD SETTLED WELL TO OUR SOUTHEAST. HIGH PRESSURE WAS LOCATED WELL TO OUR NORTHWEST...CENTERED OVER THE NORTHERN PLAINS. POST FRONTAL MOISTURE LINGERED OVER A WIDE AREA ...AND THIS MOISTURE AND CLOUDINESS WILL REMAIN FOR A WHILE. FOR TONIGHT...CLOUDY SKIES MAY EVENTUALLY PRODUCE A FEW LIGHT SHOWERS OR PATCHY DRIZZLE AS A TROUGH AXIS PASSES ACROSS THE REGION. THE CLOUDS WILL LOWER...AND SHOULD KEEP ANY FOG FORMATION FROM BEING VERY DENSE. LOWS WILL BE A FEW DEGREES COOLER THAN LAST NIGHT. ON SATURDAY...MODELS SHOW A SMALL CHANCE FOR MORNING SHOWERS PLATEAU...THEN DECREASING MOISTURE FROM NW TO SE. WE THINK CLOUDS COULD BE STUBBORN...SO EXPECT OVERCAST SKIES ALL ZONES THROUGH MIDDAY...THEN PARTIAL CLEARING GRADUALLY WORKING FROM NW TO SE ACROSS THE MID STATE THROUGH THE AFTERNOON. HIGH TEMPS WILL AGAIN BE QUITE PLEASANT...IN THE 70S. NORTH BREEZES WILL PICK UP A BIT TO HELP THE CLEARING TREND. WINDS WILL REACH 10-20 MPH IN THE EARLY AFTERNOON. DRY WX WILL CONTINUE THROUGH THE REST OF THE WEEKEND. SATURDAY NIGHT WILL BE A LITTLE CHILLY...WITH LOWS MAINLY LOWER 50S...BUT SOME 40S POSSIBLE AS WELL. SUNDAY WILL BE MAINLY SUNNY AND TEMPS WILL RECOVER TO THE UPPER 70S. LOOKING AHEAD...NEXT WEEK SHOULD BE QUIET IN THE WX DEPARTMENT. A COUPLE OF WAVES AND FRONTS WILL SWING DOWN IN THE NORTHWEST FLOW...BUT NO MAJOR RAINFALL OR TEMPERATURE ANOMALIES ARE EXPECTED. RIGHT NOW...IT LOOKS LIKE THE STRONGEST SYSTEM WILL MOVE THROUGH TUESDAY NIGHT...AND JUST INCLUDING 20 POPS AT THAT TIME. LOWS NEXT WEEK WILL BE MOSTLY IN THE UPPER 50S TO AROUND 60...WITH HIGHS IN THE MID 70S TO LOWER 80S. 13 PREV DISCUSSION... /ISSUED 1233 PM CDT FRI SEP 12 2014/ AVIATION... MVFR-IFR CIGS ARE EXPECTED TO IMPROVE SLIGHTLY THROUGH THIS AFTERNOON...BUT PERSISTENT VFR CIGS ARE NOT EXPECTED IN THE NEAR TERM. WINDS WILL BE STEADY FROM THE NORTH TO NORTHWEST THROUGH THE NIGHT SO VIS REDUCTIONS ARE NOT ANTICIPATED AT BNA OR CKV. FOR CSV EXPECT IFR-LIFR VIS AND CIGS AGAIN DURING THE OVERNIGHT...WITH CONDITIONS IMPROVING AT ALL THREE TAF SITES AFTER 14Z TOMORROW UNDER A STEADY NORTH TO NORTHEASTERLY FLOW. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 55
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
656 PM CDT FRI SEP 12 2014 .UPDATE... WILL BE ISSUING A FORECAST UPDATE AROUND 7 PM TO ADDRESS POPS FOR THE EVENING PERIOD. CURRENTLY...88D RADARS ARE SHOWING VERY LITTLE FALLING OVER THE NORTHERN TWO-THIRDS. THE TT-WRF AND HRRR SHOW ONLY LIGHT SPOTTY ACTIVITY OVER THIS AREA THIS EVENING...THUS WILL LOWER POPS TO 20 PERCENT FOR LIGHT SHOWERS/DRIZZLE. AS FOR THE SOUTHEAST COUNTIES WHERE THE COLD FRONT AND AN EASTERLY WAVE INTERACTED EARLIER THIS AFTERNOON...THE HI-RES SOLUTIONS INDICATED THAT THE SCATTERED TO NUMEROUS SHOWERS/THUNDERSTORMS WILL CONTINUE THROUGHOUT THE EVENING BEFORE WANING AFTER MIDNIGHT. THUNDERSTORMS ALONG AND SOUTHEAST OF A CAMERON TO PALESTINE LINE WILL BE CAPABLE OF 1-2 INCHES RAINFALL...DANGEROUS LIGHTNING AND SOME WIND GUST POTENTIAL UP TO 30 MPH. THE REST OF THE FORECAST REMAINS UNCHANGED. 75 && .AVIATION... /ISSUED 643 PM CDT FRI SEP 12 2014/ CIGS HAVE BEEN LIFTING DURING THE LAST FEW HOURS AS DRIER AIR ENTERS THE REGION AND THE FRONTAL LAYER DEEPENS. WITH LOWER DEWPOINTS AND HIGHER CIGS FARTHER TO THE NORTH...BELIEVE CIGS WILL PROBABLY HAVE DIFFICULTY DROPPING AFTER SUNSET. HOWEVER IF DRIZZLE OR AREAS OF HEAVIER PRECIP DOES FORM DURING THE NEXT FEW HOURS...THIS WOULD HAVE THE AFFECT OF SATURATING THE LOW LEVELS AND LOWERING CIGS AGAIN TO IFR OR POSSIBLY LOWER. FOR NOW THIS POSSIBILITY LOOKS LOW BUT WILL CONTINUE TO MONITOR. FOR THE TAFS HAVE DRY CONDITIONS AND MVFR PREVAILING THROUGH EARLY AFTERNOON TOMORROW...WITH MOS GUIDANCE LIKELY A BIT TOO QUICK IN LIFTING CIGS DUE TO WHAT IS MORE TYPICAL OF THE TIME OF YEAR. THIS AIRMASS IS SIGNIFICANTLY COLDER THAN NORMAL SO THIS STRATUS MAY BE A BIT MORE STUBBORN THAN NORMAL SEPTEMBER STRATUS. WILL INCLUDE A TEMPO FOR IFR CIGS AROUND DAYBREAK...BUT AGAIN CONFIDENCE IN THIS IS A LITTLE LOW. OTHERWISE NORTH WINDS WILL PREVAIL NEAR 10-20KT THROUGH MIDDAY TOMORROW. FOR WACO HAVE INDICATED SLIGHTLY LOWER CIGS AND THUS AN IFR FORECAST FROM OVERNIGHT THROUGH MID MORNING AS THE FRONTAL LAYER IS MORE SHALLOW THERE. NO PRECIPITATION IS MENTIONED...AS IT SHOULD STAY JUST TO THE SOUTHEAST. TR.92 && .PREV DISCUSSION... /ISSUED 245 PM CDT FRI SEP 12 2014/ THE COLD FRONT IS CURRENTLY MOVING INTO CENTRAL AND EAST TEXAS. AREAS SOUTHEAST OF A TEMPLE...MEXIA...ATHENS LINE WILL LIKELY SEE THE MOST INSTABILITY AND POTENTIAL FOR SHOWERS AND STORMS THROUGH SUNSET THIS EVENING. BEHIND THE COLD FRONT...STRONG COLD ADVECTION AND PERSISTENT STRATUS AND DRIZZLE WERE OCCURRING. SCATTERED SHOWERS WERE CONTINUING ACROSS THE NORTHEAST COUNTIES. COMBINED WITH THE BRISK NORTH WINDS 15 TO 20 MPH...TEMPERATURES HAVE FALLEN OFF INTO THE 60S NORTH OF INTERSTATE 20 WHICH HAS BROUGHT A TRUE AUTUMN FEEL TO THOSE AREAS. THE COLD FRONT SHOULD CLEAR THE CENTRAL TEXAS COUNTIES DURING THE EVENING HOURS WITH A FEW LINGERING LIGHT SHOWERS OR SPRINKLES CONTINUING OVERNIGHT. SATURATION WILL CONTINUE TO OCCUR ON THE SHALLOW FRONTAL INVERSION AND PLENTIFUL STRATUS...SO WE WILL CONTINUE TO UNDERCUT MOS HIGH TEMPERATURES BY A FEW DEGREES ON SATURDAY. THE BROAD SURFACE RIDGE EXTENDING FROM THE GREAT LAKES TO TEXAS WILL SHIFT EAST ON SUNDAY AND MONDAY. LIGHT SOUTHEAST WINDS AND WEAK LOW LEVEL WARM ADVECTION SHOULD ALLOW HIGHS TO CREEP BACK UP INTO THE 80S DESPITE CONTINUE CLOUDINESS IN THE AREA. IN ADDITION...LOW LEVEL MOISTURE WILL SLOWLY INCREASE ACROSS THE AREA WITH SURFACE DEW POINTS RISING BACK INTO THE 60S. HAVE TRIMMED SLIGHT CHANCES TO JUST THE FAR NORTHWEST AND RED RIVER COUNTIES MONDAY WHERE WEAK WARM ADVECTION COULD GENERATE A FEW SHOWERS AND STORMS. ANOTHER...YET A MUCH WEAKER COLD FRONT WILL MOVE THROUGH OKLAHOMA AND INTO NORTHWEST TEXAS MONDAY NIGHT...THEN INTO NORTH AND CENTRAL TEXAS TUESDAY. THIS COLD FRONT WILL LIKELY STALL OR WASH OUT ACROSS CENTRAL TEXAS AND NOT BRING MUCH COOLING TO THE AREA. WHAT IT WILL DO IS ACT AS A FOCUS FOR SCATTERED SHOWERS AND THUNDERSTORMS TUESDAY WITH A SHORTWAVE ALOFT MOVING SOUTHEAST ACROSS THE SOUTHERN PLAINS. BOTH MECHANISMS ARE NOT EXPECTED TO BE VIGOROUS...THUS WIDESPREAD AND SUBSTANTIAL RAINFALL IS NOT EXPECTED FROM THE EARLY WEEK SYSTEM. THE UPPER HIGH WEST OF THE AREA WILL EXPAND EAST OVER TEXAS THE LATTER HALF OF NEXT WEEK. INCREASING SUBSIDENCE AND DRYING OF THE UPPER ATMOSPHERIC COLUMN WILL ALLOW AFTERNOON HIGH TEMPERATURES TO HEAT BACK UP TO AROUND 90 DEGREES. 05/ && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 58 73 65 83 71 / 20 10 10 10 10 WACO, TX 60 75 63 85 70 / 30 10 10 10 10 PARIS, TX 55 72 59 80 66 / 20 10 10 10 10 DENTON, TX 55 72 62 83 69 / 20 10 10 10 10 MCKINNEY, TX 56 73 60 82 68 / 20 10 10 10 10 DALLAS, TX 58 74 64 83 71 / 20 10 10 10 10 TERRELL, TX 57 73 62 82 68 / 20 10 10 10 10 CORSICANA, TX 61 75 64 85 69 / 30 10 10 10 10 TEMPLE, TX 60 73 62 85 70 / 50 10 10 10 10 MINERAL WELLS, TX 55 71 62 82 68 / 20 10 10 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ /75
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
321 PM CDT THU SEP 11 2014 .DISCUSSION... PLENTY OF CHALLENGES THIS FORECAST PACKAGE AS WE TRACK A SLOW- MOVING FRONT NOW EXTENDING FROM A GATESVILLE...TO CORSICANA...TO CANTON LINE. A BROKEN LINE OF SHOWERS AND THUNDERSTORMS CONTAINING LOCALLY HEAVY RAINFALL HAS ERUPTED IN THE PAST 1-2 HOURS ALONG THE BOUNDARY. IN ADDITION...LOCALIZED FLOODING ISSUES WILL NEED TO BE MONITORED ALONG THE COLD FRONT WITH THIS BROKEN LINE OF STORMS WITH RICH PRECIPITABLE WATER VALUES WELL ABOVE 2 INCHES AND HIGH THETA-E AIR BETWEEN 700-850MB. ANY TRAINING ACTIVITY WILL LIKELY CAUSE SOME LOCALIZED HYDROLOGIC PROBLEMS. WE WILL CARRY THE HIGHEST RAIN CHANCES THIS EVENING ALONG AND AHEAD OF THE FRONT OR ACROSS THE SOUTHEAST HALF OF THE REGION. THE BEST INSTABILITY AND FORCING WITH THE COLD FRONT WILL MOST LIKELY DRIVE THIS ACTIVITY THROUGH NIGHTFALL. IN ADDITION...WE HAVE ADDED HIGHER CHANCES ACROSS THE FAR WESTERN COUNTIES FOR LATE EVENING. THE APPROACH OF A SUBTLE DISTURBANCE OVER WEST TEXAS WILL LIKELY PROVIDE ENOUGH LIFT TO SUSTAIN A FEW SHOWER OR STORMS ACROSS THE FAR WESTERN COUNTIES AFTER SUNSET. THE WEST TEXAS DISTURBANCE WILL CONTINUE TO MOVE OVER THE RED RIVER AREA AND SOUTHERN OKLAHOMA TONIGHT. NORTHERN AREAS...ESPECIALLY THOSE ALONG AND NORTH OF I-20 WILL BE UNDERNEATH THE RIGHT ENTRANCE REGION OF A 60-70KT JET STREAK STREAMING OVER OKLAHOMA. AS WE HEAD INTO FRIDAY MORNING...A STRONGER DISTURBANCE CURRENTLY OVER WYOMING WILL ROTATE SOUTHEAST OVER THE KANSAS/NEBRASKA BORDER AND SHOULD SHUNT THE JET STREAK A LITTLE FURTHER SOUTH. THE COMBINATION OF THESE FEATURES WILL PROVIDE THE SYNOPTIC LIFT...WHILE NOCTURNAL LOW LEVEL WARM ADVECTION OVERRIDES THE SHALLOW FRONTAL INVERSION. WITH THE FOCUS SHIFTING BACK NORTH...WILL MAINTAIN LIKELY CHANCES FOR RAINFALL WHICH AT TIMES COULD BE LOCALLY HEAVY...BUT NOT ENOUGH ALONG WITH ANTECEDENT DRY SOIL CONDITIONS TO ISSUE ANY FLOOD WATCHES AT THIS POINT. 500-700MB LAPSE RATES WILL BE HOVERING AROUND 6 DEG/KM WITH BOTH RUC AND NAM12 BUFKIT SOUNDINGS INDICATING A DEEP...BUT SKINNY LAYER OF CAPE. ALL TOLD...SHOWERS WILL BE LIKELY OVERNIGHT TONIGHT INTO FRIDAY MORNING ACROSS THESE AREAS WITH EMBEDDED/ELEVATED THUNDERSTORMS AT TIMES. RAIN CHANCES AFTER NIGHTFALL ACROSS CENTRAL TEXAS SHOULD DIMINISH TO LOWER CHANCES THAN WHAT WILL BE SEEN ACROSS THE NORTH. THERE WILL BE QUITE A VARIANCE ON HIGH TEMPERATURES FROM NORTHWEST TO SOUTHEAST FRIDAY. HIGHS WILL ONLY PUSH TO AROUND 70 DEGREES ACROSS THE FAR NORTHWEST... TO THE LOWER 90S ACROSS THE FAR SOUTHEAST. BETTER RAIN CHANCES SHIFT BACK OVER CENTRAL TEXAS ONCE AGAIN FRIDAY AFTERNOON INTO SATURDAY MORNING. THE PASSAGE OF THE STRONG SHORTWAVE TO THE NORTH TOWARD NORTHERN MISSOURI AND IOWA WILL HELP SEND A STRONGER AND DEEPER PUSH OF COOLER AIR INTO THE NORTHERN COUNTIES WITH THE SOUTH REMAINING WARMER AND MORE UNSTABLE. THE UPPER HIGH WILL STRENGTHEN SOME BACK OVER THE AREA THIS WEEKEND WITH JUST LINGERING LOW RAIN CHANCES ACROSS CENTRAL TEXAS WHERE DEEPER MOISTURE WILL LINGER. THESE CHANCES SHOULD END BY NIGHTFALL SATURDAY EVENING AS THE ATMOSPHERE STABILIZES. EVEN SO...CLOUD COVER ON AND ABOVE THE DEEPENING FRONTAL INVERSION WILL MAINTAIN CONSIDERABLE CLOUDINESS ACROSS THE REGION. THE CLOUDS COMBINED WITH THE COOLER AIRMASS WILL HOLD HIGHS BETWEEN 75 AND 85 DEGREES SATURDAY THAT WILL SLOWLY MODIFY TO THE 80S ON SUNDAY. THE FORECAST AFTER THE WEEKEND BECOMES CHALLENGING ONCE AGAIN AS WE MONITOR AN UPPER DISTURBANCE ROTATING AROUND THE WESTERN PERIPHERY OF THE UPPER HIGH OVER THE WESTERN GULF COAST ON MONDAY. BY MONDAY NIGHT AND TUESDAY...ANOTHER STRONG DISTURBANCE WILL MOVE DOWN WITHIN NORTHWEST FLOW ALOFT ACROSS THE CENTRAL PLAINS AND DRAG A SECOND COLD FRONT INTO SOUTHERN PLAINS BY TUESDAY. MOISTURE WILL BE PLENTIFUL ENOUGH THAT WE HAVE MAINTAINED THE LOW CHANCES FOR SHOWERS AND STORMS UNTIL TIMING AND ENVIRONMENTAL DETAILS BECOME CLEARER FOR THAT TIME FRAME AND WE CAN DIAGNOSE WHEN THE BEST CHANCES WILL OCCUR. THE LATTER HALF OF NEXT WEEK WAS KEPT DRY AND WARM FOR NOW...AS THE SECOND FRONT WASHES OUT OVER THE SOUTHERN PART OF THE STATE. HOWEVER...LOW RAIN CHANCES MAY NEED TO BE EXTENDED ACROSS OUR CENTRAL TEXAS COUNTIES IF THE FRONT STALLS FURTHER NORTH. HIGH TEMPERATURES WILL MODIFY BACK TO THE MID AND UPPER 80S WITH A FEW READINGS IN THE LOWER 90S POSSIBLE ACROSS OUR CENTRAL TEXAS COUNTIES. 05/ && .AVIATION... /ISSUED 214 PM CDT THU SEP 11 2014/ FOR THE 18Z TAFS...PRECIPITATION CHANCES AND TIMING FLIGHT CATEGORY RESTRICTIONS THIS AFTERNOON AND TONIGHT ARE THE PRIMARY FORECAST CONCERNS. FOR THIS AFTERNOON...A COLD FRONT WAS LOCATED JUST TO THE SOUTHEAST OF WACO...MOVING SLOWLY TO THE SOUTHEAST. NUMEROUS SHOWERS AND THUNDERSTORMS WERE DEVELOPING ALONG THIS FRONT AS OF 18Z...AND WILL LIKELY CONTINUE TO DO SO THROUGH THE REMAINDER OF THE AFTERNOON. WENT AHEAD WITH VCTS FROM 18 TO 00Z AT THE WACO TAF AS A RESULT. FOR THE DFW AREA...THERE WERE SOME SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS SOUTHEASTERN COLLIN COUNTY...BUT THESE WERE ELEVATED IN NATURE WELL BEHIND THE FRONT. SOME OF THIS ELEVATED ACTIVITY MAY BUILD WEST TOWARDS DFW/GKY/DAL THROUGH THE PEAK HEATING HRS OF THE DAY...SO WENT AHEAD WITH A MENTION OF VCSH IN THE TAFS THRU 21Z AS A RESULT. WILL AMEND THE TAFS IF IT LOOKS LIKE THUNDERSTORM ACTIVITY IS GOING TO GET CLOSER TO THE DFW TAFS THIS AFTERNOON. HIGH MVFR CIGS WILL HANG AROUND THE DFW AREA THROUGH 21Z...BECOMING LOW VFR THEREAFTER. THIS EVENING...RAIN SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO DISSIPATE WITH THE LOSS OF DAYTIME HEATING ACROSS THE REGION. CIGS SHOULD REMAIN VFR THROUGH MIDNIGHT. MODELS INDICATE THAT LOW- LEVEL WINDS WILL BECOME SOUTHERLY OVER THE SHALLOW COLD FRONT THIS EVENING...SETTING UP THE ENVIRONMENT FOR BETTER PRECIPITATION CHANCES ACROSS THE DFW AREA AFTER MIDNIGHT. LATE TONIGHT THRU TOMORROW MORNING...ELEVATED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP NORTH OF THE FRONT AFTER MIDNIGHT. RAIN CHANCES LOOK BEST AT THE DFW AREA BETWEEN 10 AND 14Z WHEN MOST MODEL GUIDANCE MAXIMIZES LOW-LEVEL LIFT OVER THE METROPLEX. HAVE VCSH FOR A FEW HOURS ON EITHER SIDE OF THIS WINDOW...WITH VCTS AND PERSISTENT SHOWERS IN THE 10-14Z TIME FRAME TO ACCOUNT FOR THIS LIFT. SHOWERS AND THUNDERSTORMS SHOULD DISSIPATE ACROSS THE DFW AREA DURING THE LATE MORNING HOURS AS SUBSIDENCE WORKS OVER THE AREA BEHIND THE FRONT. THE ONLY HAZARDS EXPECTED FROM THUNDERSTORM ACTIVITY ARE CLOUD TO GROUND LIGHTNING...AND REDUCED VISIBILITY FROM HEAVY RAINFALL. CAVANAUGH && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 73 75 62 77 66 / 70 70 20 10 10 WACO, TX 73 84 65 79 65 / 40 50 40 30 10 PARIS, TX 71 73 60 75 62 / 70 70 20 10 10 DENTON, TX 70 72 61 77 64 / 70 70 20 10 10 MCKINNEY, TX 70 72 59 75 63 / 70 70 20 10 10 DALLAS, TX 73 76 62 76 67 / 60 70 20 10 10 TERRELL, TX 73 79 63 76 64 / 60 70 30 10 10 CORSICANA, TX 74 83 65 79 65 / 50 50 40 20 10 TEMPLE, TX 72 86 65 78 65 / 30 60 50 30 20 MINERAL WELLS, TX 69 72 59 75 63 / 70 70 20 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ /05
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
958 AM CDT THU SEP 11 2014 .UPDATE... SEE DISCUSSION FOR MORNING UPDATE. && .DISCUSSION... NOT MANY CHANGES TO THIS MORNINGS FORECAST. WATER VAPOR CLEARLY SHOWS TROPICAL WAVE MARCHING WEST THIS MORNING. SURFACE COLD FRONT IS CURRENTLY RIGHT ON THE DALLAS/ FORT WORTH DOOR STEP. A LINE OF SHOWERS AND THUNDERSTORMS HAS FORMED JUST AHEAD OF THE FRONT. FOR SOUTHEAST TEXAS THE FRONT WILL REMAIN NORTH OF THE AREA THIS AFTERNOON UNTIL THE SHORTWAVE IN MONTANA CAN PUSH FARTHER SOUTH THIS EVENING. MOISTURE VALUES REMAIN NEAR AVERAGE FOR THE AREA WITH CONVECTIVE TEMPERATURES IN THE UPPER 80S. HIGH RES MODELS SHOWING SOME SHOWERS AND THUNDERSTORMS FORMING ALONG A SEA BREEZE THIS AFTERNOON. CURRENT FORECAST HAS THIS COVERED. ONLY MADE MINOR TWEAKS TO ACCOUNT FOR TRENDS. 23 && .PREV DISCUSSION... /ISSUED 358 AM CDT THU SEP 11 2014/ DISCUSSION... SURFACE COLD FRONT MADE SOME MORE PROGRESS EARLIER TONIGHT BEFORE LOOSING STEAM OVER THE LAST COUPLE OF HOURS. AS OF CURRENT THE FRONT WAS LOCATED JUST NORTH OF THE DALLAS/ FORT WORTH AREA. A 0Z 500 MB HAND ANALYSIS REVEALED A POTENT SHORTWAVE DIVING SOUTH OVER MONTANA. AT 250MB RIDGING HAS STARTED TO FLATTEN AS A TROUGH AXIS PUSHES IN FROM THE WEST. FOR TODAY MODELS ARE SHOWING A BIT MORE COVERAGE THAN PREVIOUSLY ADVERTISED. CURRENT PWAT VALUES... COURTESY OF GPS MET SITE... ARE AROUND 1.60". GFS FORECAST SOUNDINGS FOR THIS AFTERNOON SHOW PWAT VALUES AROUND 1.7" WITH K INDEX VALUES NEAR 30 WHILE THE NAM IS SLIGHTLY MORE AGGRESSIVE. THE RIDGE SHOULD CONTINUE TO FLATTEN THIS AFTERNOON SO WILL LEAN TO THE SLIGHTLY MORE AGGRESSIVE NAM. HIGH RES MODELS ALSO SUPPORT THIS WITH CHANCE COVERAGE ALONG THE COAST. THE FRONT SHOULD REMAIN NORTH OF THE AREA THIS AFTERNOON BUT THE RAP IS DEVELOPING PRECIP ALONG THE FRONT AND PUSHING IT INTO OUR NORTHERN ZONES THIS AFTERNOON. THIS EVENING INTO FRIDAY SOME CONVECTION COULD MAKE IT INTO OUR NORTHERN ZONES BEFORE DISSIPATING. FRIDAY MORNING A TROPICAL WAVE CURRENTLY LOCATED NEAR FLORIDA WILL APPROACH THE MEXICAN COAST LINE. AS THE TROPICAL WAVE MOVES WEST IT WILL BRING VERY MOIST AIR WITH IT. PWATS SURGE TOWARDS 2.20" FRIDAY AFTERNOON INTO SATURDAY. AT THE SAME TIME THE FRONT CURRENTLY NORTH OF DALLAS/ FORT WORTH WILL FINALLY MOVE INTO THE AREA. UPPER LEVEL SUPPORT FOR THIS SYSTEM IS WEAK THOUGH. THE SHORTWAVE CURRENTLY DIVING SOUTH IN MONTANA WILL QUICKLY START TO PULL TO THE EAST FRIDAY WHICH WILL HELP TO STALL AND WASH OUT THE FRONT OVER OUR AREA FRIDAY EVENING INTO SATURDAY MORNING. RAIN CHANCES WILL QUICKLY START TO RISE FRIDAY AS THE WAVE APPROACHES. LIFT WILL COME FROM THE SURFACE BOUNDARY AND SPEED CONVERGENCE AT 850MB. GIVEN VERY HIGH MOISTURE VALUES AND LIFT RAIN LOOKS LIKELY FRIDAY EVENING INTO SATURDAY. OMEGA VALUES FROM BOTH THE GFS AND NAM ALSO SUPPORT THIS. AS OF CURRENT IT LOOKS THAT RAIN WILL START FRIDAY MORNING OVER THE WATERS (IN ASSOCIATION WITH THE APPROACHING TROPICAL WAVE) AND JUST NORTH OF THE AREA (IN ASSOCIATION WITH THE FRONT). RAIN WILL THEN MOVE INLAND ALONG A SEA BREEZE AND POSSIBLY COLLIDE WITH ON GOING SHOWERS AND THUNDERSTORMS WITH THE SURFACE FRONT TO THE NORTH. THE EXACT LOCATION OF THE FRONT AND EXTENT OF PRECIPITATION OVER THE WATERS COULD GREATLY INFLUENCE THE EVENTUAL DISTRIBUTION OF RAINFALL. WITH THE WEAK STEERING FLOW THE CHANCE FOR HEAVY RAIN REMAINS POSSIBLE FRIDAY AFTERNOON INTO SATURDAY MORNING. ABOVE AVERAGE MOISTURE VALUES ARE EXPECTED TO REMAIN OVER THE AREA THROUGH THE WEEKEND ALLOWING THE CHANCE OF RAIN TO CONTINUE. MODELS DUE STRUGGLE ON HOW TO HANDLE THE REMNANT ENERGY OF THE WAVE THOUGH AS IT MOVES INTO MEXICO. IN GENERAL MODELS MOVE THE ENERGY NORTH AROUND A WEAK UPPER LEVEL RIDGE AND PICK IT BACK UP IN THE FLOW. THE NAM MOVES PIECES OF POSITIVE VORTICITY OVER OUR AREA SATURDAY EVENING WHILE THE GFS KEEPS THE ENERGY WEST OF US. WHERE THIS LEFTOVER ENERGY MOVES NORTH WILL AFFECT WHERE THE GREATEST CHANCES OF RAIN WILL BE SATURDAY INTO SUNDAY. BY NEXT WEEK THE UPPER LEVEL FLOW WILL AMPLIFY A BIT OVER THE EASTERN UNITED STATES ALLOWING MID LEVEL WINDS TO TURN FROM THE NORTHWEST OVER SOUTHEAST TEXAS. THIS WILL ALSO ALLOW UPPER LEVEL DISTURBANCES TO MOVE OVER THE AREA. THE BEST CHANCES OF RAIN WILL BE IN THE AFTERNOON OF EACH DAY NEXT WEEK THANKS TO DAY TIME HEATING. HAVE TRENDED POPS UP IN THE AFTERNOON FOR NEXT WEEK TO ACCOUNT FOR THIS. 23 MARINE... TYPICAL SUMMER LIKE PATTERN TODAY WITH ISO/SCT PRECIP IN COASTAL WATERS IN THE MORNING HOURS, LIGHT-MODERATE SE WINDS AND LOW SEAS. ERLY WAVE IN THE GULF WILL TRANSPORT INCREASED MOISTURE LEVELS INTO THE WATERS LATER TONIGHT LEADING TO MORE AREAL PRECIP COVERAGE FRI MORNING. AS THE WAVE APPROACHES THE WESTERN GULF COASTLINE FRI NIGHT & SATURDAY...LOOK FOR WINDS TO INCREASE, BECOME MORE ERLY AND SEAS TO BUILD. MAY NEED CAUTION FLAGS DURING THIS TIME. MODERATE ENE FLOW AND RAIN CHANCES SHOULD PERSIST THRU THE WEEKEND AS GRADIENT TIGHTENS NEAR THE COAST COMPLIMENTS OF A FRONTAL BOUNDARY LINGERING IN THE REGION. 47 AVIATION... HIGHER MOISTURE LEVELS HUGGING THE COAST WILL LEAD TO ISO/SCT PRECIP THERE AND IN THE COASTAL COUNTIES THRU LATE MORNING. IT SHOULD CREEP INLAND TODAY WITH DAYTIME HEATING AND EXPAND INTO METRO TAF SITES FROM LATE MORNING-LATE AFTN. INCLUDED SOME VCSH`S FOR NOW. FRONTAL BOUNDARY MOVING INTO N TX SHOULD PROVIDE A FOCUS FOR SOME TSRA LATER TODAY BUT SUSPECT MOST WILL REMAIN N OF CLL THRU THE TAF PERIOD SO NO MENTION THERE YET. DO ANTICIPATE A DEEPER SURGE OF MOISTURE TO MOVE INTO THE COASTAL WATERS PRIOR TO SUNRISE FRI AND EXPECT FAIRLY GOOD CHANCES OF PRECIP S OF I-10 BETWEEN 10-18Z FRI...FOLLOWED BY MORE COVERAGE FRI AFTN (BEYOND 12Z TAF). OUTSIDE OF PRECIP MAINLY VFR CONDITIONS SHOULD PREVAIL. 47 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 97 75 90 71 84 / 20 30 60 60 40 HOUSTON (IAH) 96 77 91 73 86 / 30 30 60 60 50 GALVESTON (GLS) 91 82 90 79 86 / 20 30 60 60 60 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...23
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
358 AM CDT THU SEP 11 2014 .DISCUSSION... SURFACE COLD FRONT MADE SOME MORE PROGRESS EARLIER TONIGHT BEFORE LOOSING STEAM OVER THE LAST COUPLE OF HOURS. AS OF CURRENT THE FRONT WAS LOCATED JUST NORTH OF THE DALLAS/ FORT WORTH AREA. A 0Z 500 MB HAND ANALYSIS REVEALED A POTENT SHORTWAVE DIVING SOUTH OVER MONTANA. AT 250MB RIDGING HAS STARTED TO FLATTEN AS A TROUGH AXIS PUSHES IN FROM THE WEST. FOR TODAY MODELS ARE SHOWING A BIT MORE COVERAGE THAN PREVIOUSLY ADVERTISED. CURRENT PWAT VALUES... COURTESY OF GPS MET SITE... ARE AROUND 1.60". GFS FORECAST SOUNDINGS FOR THIS AFTERNOON SHOW PWAT VALUES AROUND 1.7" WITH K INDEX VALUES NEAR 30 WHILE THE NAM IS SLIGHTLY MORE AGGRESSIVE. THE RIDGE SHOULD CONTINUE TO FLATTEN THIS AFTERNOON SO WILL LEAN TO THE SLIGHTLY MORE AGGRESSIVE NAM. HIGH RES MODELS ALSO SUPPORT THIS WITH CHANCE COVERAGE ALONG THE COAST. THE FRONT SHOULD REMAIN NORTH OF THE AREA THIS AFTERNOON BUT THE RAP IS DEVELOPING PRECIP ALONG THE FRONT AND PUSHING IT INTO OUR NORTHERN ZONES THIS AFTERNOON. THIS EVENING INTO FRIDAY SOME CONVECTION COULD MAKE IT INTO OUR NORTHERN ZONES BEFORE DISSIPATING. FRIDAY MORNING A TROPICAL WAVE CURRENTLY LOCATED NEAR FLORIDA WILL APPROACH THE MEXICAN COAST LINE. AS THE TROPICAL WAVE MOVES WEST IT WILL BRING VERY MOIST AIR WITH IT. PWATS SURGE TOWARDS 2.20" FRIDAY AFTERNOON INTO SATURDAY. AT THE SAME TIME THE FRONT CURRENTLY NORTH OF DALLAS/ FORT WORTH WILL FINALLY MOVE INTO THE AREA. UPPER LEVEL SUPPORT FOR THIS SYSTEM IS WEAK THOUGH. THE SHORTWAVE CURRENTLY DIVING SOUTH IN MONTANA WILL QUICKLY START TO PULL TO THE EAST FRIDAY WHICH WILL HELP TO STALL AND WASH OUT THE FRONT OVER OUR AREA FRIDAY EVENING INTO SATURDAY MORNING. RAIN CHANCES WILL QUICKLY START TO RISE FRIDAY AS THE WAVE APPROACHES. LIFT WILL COME FROM THE SURFACE BOUNDARY AND SPEED CONVERGENCE AT 850MB. GIVEN VERY HIGH MOISTURE VALUES AND LIFT RAIN LOOKS LIKELY FRIDAY EVENING INTO SATURDAY. OMEGA VALUES FROM BOTH THE GFS AND NAM ALSO SUPPORT THIS. AS OF CURRENT IT LOOKS THAT RAIN WILL START FRIDAY MORNING OVER THE WATERS (IN ASSOCIATION WITH THE APPROACHING TROPICAL WAVE) AND JUST NORTH OF THE AREA (IN ASSOCIATION WITH THE FRONT). RAIN WILL THEN MOVE INLAND ALONG A SEA BREEZE AND POSSIBLY COLLIDE WITH ON GOING SHOWERS AND THUNDERSTORMS WITH THE SURFACE FRONT TO THE NORTH. THE EXACT LOCATION OF THE FRONT AND EXTENT OF PRECIPITATION OVER THE WATERS COULD GREATLY INFLUENCE THE EVENTUAL DISTRIBUTION OF RAINFALL. WITH THE WEAK STEERING FLOW THE CHANCE FOR HEAVY RAIN REMAINS POSSIBLE FRIDAY AFTERNOON INTO SATURDAY MORNING. ABOVE AVERAGE MOISTURE VALUES ARE EXPECTED TO REMAIN OVER THE AREA THROUGH THE WEEKEND ALLOWING THE CHANCE OF RAIN TO CONTINUE. MODELS DUE STRUGGLE ON HOW TO HANDLE THE REMNANT ENERGY OF THE WAVE THOUGH AS IT MOVES INTO MEXICO. IN GENERAL MODELS MOVE THE ENERGY NORTH AROUND A WEAK UPPER LEVEL RIDGE AND PICK IT BACK UP IN THE FLOW. THE NAM MOVES PIECES OF POSITIVE VORTICITY OVER OUR AREA SATURDAY EVENING WHILE THE GFS KEEPS THE ENERGY WEST OF US. WHERE THIS LEFTOVER ENERGY MOVES NORTH WILL AFFECT WHERE THE GREATEST CHANCES OF RAIN WILL BE SATURDAY INTO SUNDAY. BY NEXT WEEK THE UPPER LEVEL FLOW WILL AMPLIFY A BIT OVER THE EASTERN UNITED STATES ALLOWING MID LEVEL WINDS TO TURN FROM THE NORTHWEST OVER SOUTHEAST TEXAS. THIS WILL ALSO ALLOW UPPER LEVEL DISTURBANCES TO MOVE OVER THE AREA. THE BEST CHANCES OF RAIN WILL BE IN THE AFTERNOON OF EACH DAY NEXT WEEK THANKS TO DAY TIME HEATING. HAVE TRENDED POPS UP IN THE AFTERNOON FOR NEXT WEEK TO ACCOUNT FOR THIS. 23 && .MARINE... TYPICAL SUMMER LIKE PATTERN TODAY WITH ISO/SCT PRECIP IN COASTAL WATERS IN THE MORNING HOURS, LIGHT-MODERATE SE WINDS AND LOW SEAS. ERLY WAVE IN THE GULF WILL TRANSPORT INCREASED MOISTURE LEVELS INTO THE WATERS LATER TONIGHT LEADING TO MORE AREAL PRECIP COVERAGE FRI MORNING. AS THE WAVE APPROACHES THE WESTERN GULF COASTLINE FRI NIGHT & SATURDAY...LOOK FOR WINDS TO INCREASE, BECOME MORE ERLY AND SEAS TO BUILD. MAY NEED CAUTION FLAGS DURING THIS TIME. MODERATE ENE FLOW AND RAIN CHANCES SHOULD PERSIST THRU THE WEEKEND AS GRADIENT TIGHTENS NEAR THE COAST COMPLIMENTS OF A FRONTAL BOUNDARY LINGERING IN THE REGION. 47 && .AVIATION... HIGHER MOISTURE LEVELS HUGGING THE COAST WILL LEAD TO ISO/SCT PRECIP THERE AND IN THE COASTAL COUNTIES THRU LATE MORNING. IT SHOULD CREEP INLAND TODAY WITH DAYTIME HEATING AND EXPAND INTO METRO TAF SITES FROM LATE MORNING-LATE AFTN. INCLUDED SOME VCSH`S FOR NOW. FRONTAL BOUNDARY MOVING INTO N TX SHOULD PROVIDE A FOCUS FOR SOME TSRA LATER TODAY BUT SUSPECT MOST WILL REMAIN N OF CLL THRU THE TAF PERIOD SO NO MENTION THERE YET. DO ANTICIPATE A DEEPER SURGE OF MOISTURE TO MOVE INTO THE COASTAL WATERS PRIOR TO SUNRISE FRI AND EXPECT FAIRLY GOOD CHANCES OF PRECIP S OF I-10 BETWEEN 10-18Z FRI...FOLLOWED BY MORE COVERAGE FRI AFTN (BEYOND 12Z TAF). OUTSIDE OF PRECIP MAINLY VFR CONDITIONS SHOULD PREVAIL. 47 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 97 75 90 71 85 / 20 30 60 60 40 HOUSTON (IAH) 95 77 91 73 86 / 30 30 60 60 50 GALVESTON (GLS) 91 82 90 79 86 / 20 30 60 60 60 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...23 AVIATION/MARINE...47
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1150 PM CDT WED SEP 10 2014 .DISCUSSION... SEE THE 06Z AVIATION DISCUSSION BELOW. 40 && .AVIATION... A COUPLE OF ITEMS TO COVER FOR THIS FORECAST PERIOD. THE FIRST WILL BE THE POSSIBILITY FOR MVFR CONDITIONS TONIGHT THROUGH 14Z THURSDAY MORNING. BEST CHANCES APPEAR TO BE AT KCLL...KUTS...AND KCXO. THE LATEST NAM12 SHOWED A LOW-LEVEL JET OVERHEAD OF KCLL WHICH SHOULD TRANSLATE TO A LOW CLOUD DECK FORMING BETWEEN 08Z AND 10Z AT THE THREE SITES. THE SECOND ITEM REGARDS RAIN CHANCES. DECENT MOISTURE ADVECTION WAS HELPING FORM ISOLATED SHOWERS IN THE GULF AT 0430Z. THE HIGH RESOLUTION AND NAM12 MODELS ALL INDICATE THESE MAY WORK THEIR WAY INTO KGLS AFTER 09Z. THE NAM12 WEAKENS THE SURFACE PRESSURE GRADIENT AS IT BUILDS A HIGH PRESSURE RIDGE INTO THE COASTAL AREAS FROM THE EAST. HOWEVER...THE MOISTURE INCREASES DURING THE AFTERNOON PERIOD WITH PW/S REACHING TO BETWEEN 1.9 AND 2.2 INCHES. WITH THIS IN MIND...FELT THERE WAS A DECENT CHANCE FOR ISOLATED SHOWERS TO AFFECT THE INLAND SITES DURING THE AFTERNOON FROM KLBX TO KCXO. FOR NOW WILL GO WITH A VICINITY MENTION. LASTLY...DECENT RAIN CHANCES ARE LOOKING TO OCCUR WITH THE ADVANCE OF A COLD FRONT INTO SE TX ON FRIDAY. THE FORECAST COVERAGE AND TIMING BY THE MODELS IS TOO BROAD AT THIS TIME TO PINPOINT FOR THE AVIATION SITES. FOR NOW THE BEST CHANCES LOOK TO BEGIN FROM HOUSTON TO THE COAST SOMETIME LATE MORNING ON FRIDAY. 40 && .PREV DISCUSSION... /ISSUED 952 PM CDT WED SEP 10 2014/ UPDATE... SEE EVENING UPDATE. DISCUSSION... AT 8 PM...A COLD FRONT EXTENDED FROM FT SMITH TO NEAR SHERMAN TO BIG SPRINGS. AT 850 MB...A TROUGH OF LOW PRESSURE EXTENDED NORTH TO SOUTH ACROSS WEST TEXAS WITH DEEP 850 MOISTURE OVER OK...AR AND NE TX. ANOTHER WEAK TROUGH WAS NOTED BETWEEN OKC AND DFW. 850 TEMPS WERE -3 C AT GLASGOW MT WHICH IS PRETTY COOL FOR THIS TIME OF YEAR. A POOL OF DEEPER 700 MB MOISTURE WAS LOCATED OVER N TX AND S OK WITH A WEAK TROUGH OVER SW TX. AT 250 MB...A BROAD TROUGH WAS LOCATED OVER THE CENTRAL PLAINS WITH UPPER LEVEL RIDGING EXTENDING FROM THE SOUTHERN APPALACHIANS ACROSS COASTAL TEXAS. 00Z MODEL RUNS ARE JUST COMING IN BUT SHORT TERM GUIDANCE IS TRENDING WETTER FOR THURSDAY. THE RAP IN PARTICULAR BRINGS IN SLIGHTLY HIGHER MOISTURE EARLY THURSDAY MORNING COURTESY OF A BROAD EASTERLY WAVE THAT EXTENDS FROM THE MS COAST TO THE MEXICAN COAST. 00Z SOUNDINGS CAME IN DRY AND GPS MET NETWORK SHOWS PW VALUES AROUND 1.6 INCHES WHICH IS ON THE DRY SIDE FOR EARLY SEPT. YET THE RAP AND TO A LESSER EXTENT THE HRRR...ARW AND TEXAS TECH WRF SHOW SHRA/TSRA DEVELOPING BY 13Z AND SPREADING INLAND. THE RAP ALSO BRINGS A WIND SHIFT TO THE COLLEGE STATION AREA AROUND 18Z. PRESSURE RISES BEHIND THE FRONT ARE NOT THAT IMPRESSIVE SO PREFER THE NAM 12 FOR FRONTAL TIMING. ADDED POPS FOR LATE TONIGHT ALONG THE COAST AND ADDED MORNING POPS FOR AREAS SOUTH OF I-10. NEW ZONES OUT BY 10 PM. 43 CLIMATE... CRUNCHING SOME NUMBERS TONIGHT ON RAINFALL DEFICITS ACROSS THE AREA. GALVESTON IS OVER 75 INCHES BELOW NORMAL SINCE JAN 1 2009. HOBBY AIRPORT IS NOT THAT FAR BEHIND AND IS 65 INCHES BELOW NORMAL SINCE 2009. HOPEFULLY RAIN THIS WEEKEND WILL PUT A DENT INTO SOME THESE NUMBERS. HURRICANE CARLA MADE LANDFALL ON SEPT 11 1961. IT`S THE LAST CAT 4 TO AFFECT THE UPPER TEXAS COAST. CARLA WAS BRIEFLY A CAT 5 OVER THE GULF. 43 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 77 97 75 90 71 / 10 20 30 60 60 HOUSTON (IAH) 77 96 77 91 74 / 10 20 30 60 60 GALVESTON (GLS) 83 91 82 90 79 / 20 20 30 60 60 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...43 AVIATION/MARINE...40
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FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND FRIDAY ISSUED AT 254 PM CDT THU SEP 11 2014 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A 1037MB CANADIAN HIGH PRESSURE SYSTEM BUILDING SOUTHEAST ACROSS THE NORTHERN PLAINS AND MISSISSIPPI VALLEY. THE COMBO OF NORTHERLY FLOW OFF LAKE SUPERIOR AND DIURNAL HEATING HAS MAINTAINED THE BROKEN TO OVERCAST CONDITIONS ACROSS THE REGION. CLOUDS ARE LOOKING MORE CELLULAR OVER N-C WISCONSIN INDICATING A DIURNAL COMPONENT TO THE CLOUD MASS. SCATTERED SHOWERS ARE OCCURRING OVER NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN...WITH HELP FROM A WEAK SHORTWAVE OVER THAT REGION. THIS WAVE IS LIFTING OFF TO THE NORTHEAST...SO DO NOT THINK THE SHOWER ACTIVITY WILL REACH INTO N-C WISCONSIN THIS AFTERNOON. THE NEXT SHORTWAVE IS DIVING SOUTHEAST OVER SOUTHERN MONTANA AND WILL MOVE EAST TOWARDS THE REGION TOMORROW. THE MAIN CONCERNS ARE FROST POTENTIAL TONIGHT AND LIGHT RAIN CHANCES TOMORROW. TONIGHT...CANADIAN HIGH PRESSURE WILL BUILD TOWARDS THE REGION AS A POTENT SHORTWAVE MOVES ACROSS THE NORTHERN PLAINS. AS SURFACE PRESSURE RISES...LOW LEVEL FLOW WILL BECOME BROADLY ANTICYCLONIC...WHICH WILL PROMOTE BREAKING UP OF THE LOW STRATUS. HOWEVER...EVEN THOUGH THE FLOW WILL BECOME LIGHT...TRAJECTORIES ARE ONSHORE OFF LAKE SUPERIOR WHERE DELTA T/S ARE SUFFICIENT FOR LAKE CLOUDS. ADDITIONALLY...THERE IS REALLY NO SOURCE OF DRY AIR TO BE FOUND ACROSS THE REGION. EVEN THOUGH CLOUDS OVER THE WESTERN PART OF THE STATE APPEAR TO HAVE A DIURNAL LOOK TO THEM...CLOUDS ORIGINATING OFF LAKE SUPERIOR COULD BECOME TRAPPED BENEATH THE NOCTURNAL INVERSION. FURTHERMORE...MID AND HIGH CLOUDS WILL BE INCREASING AFTER MIDNIGHT AHEAD OF THE SHORTWAVE OVER THE PLAINS. ALL OF THIS MAKES FOR A LOW CONFIDENCE CLOUD/TEMP/FROST FORECAST. BECAUSE WE ARE ALREADY OFF TO A COLD START...ANY AMOUNT OF CLEARING WILL CAUSE TEMPS TO FALL QUICKLY OVER N-C WISCONSIN. MET/MAV/MEX GUIDANCE ALL SHOW LOW TEMPS IN THE LOWER 30S OVER N-C WISCONSIN. WILL ERROR ON THE SIDE OF CAUTION BECAUSE OF THIS POTENTIAL AND ISSUE A FROST ADVISORY FOR N-C WISCONSIN. THE REST OF THE AREA SHOULD SEE TEMPS IN THE UPPER 30S TO MIDDLE 40S. FRIDAY...THE POTENT SHORTWAVE WILL MOVE ACROSS THE NORTHERN MISSISSIPPI VALLEY AND INTO WESTERN WISCONSIN. EVEN THOUGH QG FORCING AHEAD OF THE WAVE LOOKS RATHER IMPRESSIVE...MOISTURE WILL ONLY BE 60 TO 80 PCT OF NORMAL AND INSTABILITY IS RATHER POOR. CHANCES FOR PRECIP WILL IMPROVE DURING THE AFTERNOON AS THE WAVE APPROACHES AND UPPER DIVERGENCE INCREASES. MODELS ARE ALSO INDICATING MID-LEVEL CONVERGENCE OVER NORTHEAST AND EAST-CENTRAL WISCONSIN THAT COULD PROVIDE A FOCUS FOR A BAND OF LIGHT RAIN. WILL INCREASE PRECIP CHANCE IN THIS AREA FOR THE AFTERNOON. NORTH-CENTRAL WILL HAVE THE NEXT BEST CHANCE OF SEEING RAIN WHERE THE DEFORMATION ZONE APPROACHES DURING THE AFTERNOON. SHOULD BE ANOTHER CLOUDY AND COOL DAY WITH HIGHS IN THE LOW TO MID 50S. .LONG TERM...FRIDAY NIGHT THROUGH THURSDAY ISSUED AT 254 PM CDT THU SEP 11 2014 LIGHT RAIN SHOULD END IN EASTERN WISCONSIN FRIDAY EVENING AS THE UPPER SYSTEM EXITS. IF THERE IS SUFFICIENT CLEARING THERE COULD BE A FREEZE OR FROST IN NORTHCENTRAL WISCONSIN FRIDAY NIGHT. SUNNY AND COOL WEATHER SATURDAY AS A SURFACE HIGH MOVES BY. CLOUDS WILL INCREASE SUNDAY AS A WEAK FRONTAL SYSTEM APPROACHES FROM THE NORTHERN PLAINS. NOT MUCH MOISTURE AVAILABLE SO ONLY EXPECT SCATTERED SHOWERS SUNDAY NIGHT AND MONDAY WITH THE FRONTAL PASSAGE. THEN DRY AND SEASONABLE FOR MUCH OF THE REMINDER OF NEXT WEEK WITH NORTHWEST FLOW ALOFT. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1153 AM CDT THU SEP 11 2014 WIDESPREAD BROKEN MVFR CIGS WILL PREVAIL FOR MUCH OF THE AFTERNOON...THOUGH EXPECTING CIGS TO SLOWLY RISE...POSSIBLY TO VFR BY 22-00Z. DIFFICULT TO ESTIMATE WHEN BKN CIGS WILL SCATTER DUE TO NORTHERLY UNSTABLE FLOW OFF LAKE SUPERIOR CONTINUING THROUGH THE NIGHT. THE BEST GUESS IS SOMETIME THIS EVENING WHEN THIS FLOW OFF LAKE SUPERIOR LIGHTENS AND THE INVERSION WEAKENS. BUT IF THE NOCTURNAL INVERSION DUE TO COOLING TRAPS THE RESIDUAL MOISTURE IN THE BOUNDARY LAYER...THEN BKN CLOUDS COULD STICK AROUND FOR MUCH OF THE NIGHT. IF CLOUDS DO SCATTER...THEN BKN CIGS WILL LIKELY DEVELOP AGAIN BY MIDDAY TOMORROW AHEAD OF THE NEXT UPPER DISTURBANCE. && .GRB WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY FROM MIDNIGHT TONIGHT TO 8 AM CDT FRIDAY FOR WIZ005-010>012-018-019. && $$ SHORT TERM.....MPC LONG TERM......RDM AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1128 PM MDT FRI SEP 12 2014 .UPDATE... ISSUED AT 549 PM MDT FRI SEP 12 2014 LOOKING AT SAT PIX...AND HI RES RH FIELDS IN THE LOWER LVLS OF THE ATMOSPHERE AND PRGD SOUNDINGS...HAVE PLAYED UP MORE LOW CLOUDS FOR TONIGHT THAN WERE IN EARLIER FCST PRODUCTS. FCST ARE BEING UPDATED AS I WRITE. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 242 PM MDT FRI SEP 12 2014 WIDESPREAD LOW CLOUDS CONTINUE TO COVER THE SERN CO PLAINS THIS AFTERNOON...WITH TEMPS IN THE 40S. THE REST OF THE FORECAST AREA HAS HAD MOSTLY SUNNY SKIES...WITH SOME CONVECTIVE CLOUDS DEVELOPING OVER THE SRN MTNS AND SAN LUIS VALLEY. THERE CONTINUES TO BE SOME SPOTTY LIGHT DRIZZLE IN LOCATIONS NR THE ERN MTNS. THE NAM HAS WAY OVERDONE THE PCPN OVR THE SERN PLAINS FOR TODAY...WITH THE HRRR BEING MORE REASONABLE. FOR THIS EVENING AND OVERNIGHT THE NAM PRINTS OUT SOME ISOLD PCPN OVR THE SRN CO MTNS. THE HRRR IS DRY FOR THIS EVENING. IT IS POSSIBLE THAT A FEW SHOWERS COULD DEVELOP FOR THE EVENING HOURS...BUT FOR NOW WL LEAVE SILENT POPS IN THE FORECAST. THE NAM AND HRRR ARE STILL SHOWING A DECREASE IN LOW LEVEL CLOUD COVER LATER THIS AFTERNOON AND EARLY THIS EVENING...BUT NOT SEEING ANY EVIDENCE OF THIS IN THE SATELLITE IMAGES YET. BOTH MODELS THEN SHOW THE POTENTIAL FOR LOW CLOUD REFORMING OVR PORTIONS OF THE PLAINS BY LATE EVENING. OVERNIGHT LOW TEMPS ARE EXPECTED TO BE IN THE UPPER 30S TO LOWER 40S OVR THE SERN PLAINS...THE COLDEST AREAS LOOK TO BE NORTHERN PORTIONS OF PUEBLO COUNTY...EL PASO AND CROWLEY COUNTIES. LOWS IN THESE LOCATIONS LOOK LIKE THEY WL BE IN THE LOWER 30S. HAVE DECIDED TO ISSUE A FROST ADVISORY FOR THESE COUNTIES JUST IN CASE THERE ARE POCKETS OF FROST. MODELS ARE INDICATING THAT THE LOW CLOUDS SHOULD DISSIPATE BY LATE MORNING ON SATURDAY WITH A GOOD WARM UP IN STORE. HIGHS ON SAT OVR THE SERN PLAINS SHOULD BE IN THE 70S...WITH MID TO UPPER 70S IN THE SAN LUIS VALLEY. GENERALLY DRY WESTERLY FLOW ALOFT IS EXPECTED OVR THE FORECAST AREA. THE NAM AGAIN PRINTS OUT SOME LIGHT PCPN OVR THE SRN CO MTNS AND SAN LUIS VALLEY SAT AFTERNOON...SO WL LEAVE SOME ISOLD POPS IN THE FORECAST FOR THE SW MTNS AND THE SANGRES. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 242 PM MDT FRI SEP 12 2014 MODELS IN GOOD AGREEMENT THROUGH THE EXTENDED PERIOD WITH SMALL ENSEMBLE SPREADS AND HIGHER FORECAST CONFIDENCE. SATURDAY NIGHT THROUGH SUNDAY NIGHT...FLAT ZONAL WESTERLY FLOW WILL PERSIST ACROSS COLORADO THROUGH THIS PERIOD AS AN UPPER RIDGE BEGINS TO BUILD ALONG THE WEST COAST AND SHORTWAVE TROUGH DROPS SOUTH OUT OF CANADA INTO THE NORTHERN PLAINS. EXPECT ISOLATED SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS ON SATURDAY EVENING TO DISSIPATE AROUND SUNDOWN WITH LOSS OF DAYTIME INSTABILITY. OVERNIGHT LOWS WILL FALL INTO THE MID TO UPPER 40S FOR MUCH OF THE REGION. A WEAK DISTURBANCE EMBEDDED IN THE WESTERLY FLOW ALOFT WILL MOVE ACROSS THE STATE ON SUNDAY AFTERNOON. ANOTHER ROUND OF ISOLATED TO SCATTERED MOUNTAIN SHOWERS AND THUNDERSTORMS ARE EXPECTED...WHICH SHOULD DISSIPATE ON SUNDAY EVENING. HIGHS SUNDAY WILL REACH INTO THE 80S FOR THE LOWER ELEVATIONS. MONDAY AND MONDAY NIGHT...MODELS IN GOOD AGREEMENT WITH A STRONG COLD FRONT DROPPING SOUTH ACROSS THE EASTERN PLAINS ON MONDAY MORNING. THE NAM IS THE FASTEST SOLUTION...WITH IT CLEARING SOUTH INTO NEW MEXICO BY 12Z...WHILE THE ECMWF AND GFS ARE ABOUT 6 HOURS SLOWER. FEEL THAT A BIT FASTER SOLUTIONS WILL LIKELY PLAY OUT AND FOLLOWED THE NAM FRONTAL PROGRESSION. EXPECT LOW LEVEL FLOW TO TURN EASTERLY AND USHER IN MUCH COOLER AIR INTO THE PLAINS. UPGLIDE AND MOISTURE BEHIND THE FRONT WILL LIKELY LEAD TO LIGHT RAIN FOR THE PLAINS THROUGH MONDAY AFTERNOON. WARMER TEMPERATURES AND GREATER INSTABILITY WILL EXIST OVER THE MOUNTAIN AREAS MONDAY AFTERNOON AND SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED. MODELS IN AGREEMENT WITH THE LIGHT RAIN COMING TO AN END FOR THE PLAINS FROM NORTH TO SOUTH THROUGH THE AFTERNOON HOURS. EXPECT THUNDERSTORMS OVER THE MOUNTAINS TO DISSIPATE AFTER SUNSET. TEMPERATURES WILL BE MUCH COOLER BEHIND THE FRONT WITH THE PLAINS LIKELY ONLY SEEING 60S FOR HIGHS. TUESDAY THROUGH FRIDAY...THE UPPER PATTERN WILL BECOME AMPLIFIED ACROSS THE CONUS WITH HIGH PRESSURE BUILDING OVER THE WEST AND A TROUGH OVER THE EASTERN STATES. THIS WILL PUT SOUTHERN COLORADO UNDER BROAD NORTHWEST FLOW. EXPECT GENERALLY DRY CONDITIONS ACROSS THE REGION WITH DAILY AFTERNOON AND EVENING MOUNTAIN CONVECTION POSSIBLE. TEMPERATURES WILL BE QUICK TO WARM UP WITH 80S FOR THE LOWER ELEVATIONS THROUGH THE MIDDLE OF THE WEEK. BY FRIDAY MODELS ARE BRINGING A PIECE OF ENERGY FROM TROPICAL STORM ODILE WHICH IS FORECAST TO BE OFF THE NORTHERN BAJA COAST BY FRIDAY. IF THIS DISTURBANCE AND MOISTURE DOES MATERIALIZE...THERE WILL BE MUCH BETTER CHANCES FOR PRECIPITATION...ESPECIALLY ALONG THE CONTINENTAL DIVIDE...BY FRIDAY. THIS WILL NEED TO BE MONITORED. MOZLEY && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1125 PM MDT FRI SEP 12 2014 NOT MUCH CHANGE FOR PREVIOUS THINKING...KCOS AND KPUB WILL LIKELY REMAIN IN MVFR/IFR CONDITIONS THROUGH TOMOROW MORNING. KCOS SHOULD CLEAR OUT AOA 16-17Z WHILE KPUB AN HOUR OR SO LATER. OTHERWISE...VFR CONDITIONS ANTICIPATED. && .PUB WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY UNTIL 8 AM MDT SATURDAY FOR COZ084>086-089. && $$ UPDATE...HODANISH SHORT TERM...28 LONG TERM...MOZLEY AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS TAUNTON MA
356 AM EDT SAT SEP 13 2014 .SYNOPSIS... HIGH PRESSURE DOMINATES OVERNIGHT. A QUICK MOVING WEATHER SYSTEM WILL BRING SCATTERED SHOWERS TO THE AREA LATE SATURDAY AFTERNOON AND EARLY EVENING. HIGH PRESSURE BRINGS DRY WEATHER WITH SLIGHTLY BELOW NORMAL TEMPERATURES SUNDAY INTO MONDAY. THE NEXT COLD FRONT WILL LIKELY BRING A PERIOD OF SHOWERS LATE MONDAY NIGHT INTO TUESDAY. MAINLY DRY WEATHER EXPECTED NEXT WEDNESDAY THROUGH FRIDAY WITH SLIGHTLY BELOW NORMAL TEMPERATURES CONTINUING. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 130 AM UPDATE... ADJUSTED SKY COVER GRIDS BASED ON LATEST OBSERVATIONS AND SATELLITE PICTURES. RAP SEEMS TO HAVE BEST HANDLE ON PATCHES OF STRATOCUMULUS. ADJUSTED TEMPERATURES STILL A LITTLE COOLER IN SE ZONES BASED ON LATEST OBSERVED TRENDS. 1015 PM UPDATE... QUIET NIGHT WITH LITTLE CHANGE NEEDED IN FORECAST. DID LOWER HOURLY AND MIN TEMPS FOR PORTIONS OF SE MA AND MARTHAS VINEYARD TO ACCOUNT FOR CURRENT TRENDS AND CLIMATOLOGY. KEPT POP NEAR ZERO PERCENT THROUGH 8 AM AND JUST MADE A FEW TWEAKS WITH THE SKY COVER TO BE CONSISTENT WITH CURRENT TRENDS. 630 PM UPDATE... STRATO-CUMULUS CLOUDS HAVE DISSIPATED EARLY THIS EVENING ACROSS THE CAPE AND ISLANDS. OTHERWISE...MAINLY CLEAR SKIES WERE IN PLACE EARLY THIS EVENING OTHER THAN A TOUCH OF HIGH CLOUDINESS. IDEAL SEP WEATHER ACROSS THE REGION THROUGH THE EVENING WITH MAINLY CLEAR SKIES...COMFORTABLE TEMPS AND LIGHT WINDS. AFTER SUNSET...TEMPS WILL FALL FAIRLY QUICKLY GIVEN DRY ATMOSPHERE...CLEAR SKIES AND LIGHT WINDS. MANY LOCATIONS WILL DIP INTO THE MU40S TONIGHT INCLUDING PLACES SUCH AS MARTHAS VINEYARD... NORWOOD AND OTHER INTERIOR EASTERN MA LOCATIONS. ALSO WESTERN MA AND SOUTHWEST NH SHOULD FALL INTO THE MU40S. ELSEWHERE MINS WILL BE IN THE LOW TO MID 50S. TRICKY PART TO THE FORECAST WILL BE IF SOME LOW CLOUDS ARE ABLE TO DEVELOP NEAR THE COAST TOWARD DAYBREAK. THESE CLOUDS MAY REAPPEAR TOWARD SUNRISE GIVEN BLYR COOLING OVERNIGHT. THUS COULD SEE SKIES BECOME PARTLY TO MOSTLY CLOUDY TOWARD DAYBREAK OVER EASTERN MA AND POSSIBLY INTO RI...BUT CONFIDENCE IS LOW. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/... SATURDAY... DRY TO START THE DAY BUT QUICK MOVING NORTHERN STREAM SHORT WAVE TROUGH APPROACHES FROM THE WEST. TWO AREAS OF SHOWERS WILL TRACK ACROSS THE NORTHEAST. FIRST BATCH WILL BE OVER NY STATE AND NORTHERN NEW ENGLAND WITH PARENT LOW AND ACCOMPANYING LOW TO MID LEVEL JET. A SECOND AREA OF SHOWERS WILL TRACK SOUTH OF NEW ENGLAND AS LAST NIGHT/S FRONTAL BOUNDARY LIFTS NORTHWARD WITH SECONDARY LOW PRES DEVELOPING ON THE FRONT IN RESPONSE TO RRQ OF THE UPPER JET STREAK. THIS YIELDS LIKELY POPS ACROSS CAPE COD AND THE ISLANDS WITH CHANCE POPS ELSEWHERE FOR SCATTERED SHOWERS. GREATEST RISK OF SHOWERS IS SOMEWHERE BETWEEN 4-8 PM. COULD BE SOME HEAVIER SHOWERS ALONG SOUTH COAST AND OFFSHORE AS PWATS CLIMB TO 2 INCHES /+2 STD FROM CLIMO/. HOWEVER INSTABILITY ALOFT AND AT THE SURFACE IS LACKING SO HEAVIER SHOWERS AND THUNDER MAY BE WELL OFFSHORE. SYSTEM IS VERY PROGRESSIVE SO NOT EXPECTING A SOAKING RAIN. IN FACT SOME LOCATIONS MAY ONLY SEE A TRACE OF RAINFALL WITH OTHER LOCATIONS SUCH AS WELL INLAND AND ALONG THE SOUTH COAST PERHAPS A TENTH OR TWO. TEMPS A FEW DEGS COOLER THAN TODAY GIVEN THE COOLER START ALONG WITH INCREASING CLOUDS AND LIGHT ONSHORE WINDS. SATURDAY NIGHT... QUICK MOVING SYSTEM EXITS THE REGION BETWEEN 00Z WEST TO PERHAPS 03Z CAPE COD. EXPECT DECREASING CLOUDS AND DRIER AIR TO OVERSPREAD THE REGION. NORTHERLY WINDS WILL BECOME GUSTY LATE AT NIGHT AND TOWARD SUNRISE SUNDAY WITH A FEW GUSTS UP TO 25 MPH POSSIBLE. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... HIGHLIGHTS... * LOW RISK OF PATCHY FROST SUN NIGHT ACROSS DISTANT INTERIOR * A PERIOD OF SHOWERS LIKELY LATE MON NIGHT/TUE * DRY WEATHER/SLIGHTLY BELOW NORMAL TEMPS NEXT WED-FRI OVERVIEW... OVERALL MODEL GUIDANCE IS IN AGREEMENT WITH A BROAD TROUGH OVER THE EASTERN HALF OF THE CONTINENT AND A FULL-LATITUDE RIDGE OVER WESTERN NORTH AMERICA. IN FACT APPEARS THAT THE NORTHERN BRANCH OF THE JET STREAM REMAINS FAIRLY PROGRESSIVE ESP SINCE THE NAO TRENDING MORE POSITIVE FOR THE FIRST HALF OF THIS FORECAST. THE FLOW DOES BEGIN TO BECOME MORE AMPLIFIED TOWARDS THE END OF THE PERIOD AS A TROUGH DIGS OVER THE EASTERN PACIFIC LEADING TO A RIDGE IN THE CENTRAL CONUS....ABOUT WHEN THE NAO BECOMES MORE NEUTRAL. HOWEVER IT LOOKS LIKE THE EASTERN CONUS WILL STILL REMAIN IN A TROUGH PATTERN THROUGH THE WORK WEEK WITH A POSSIBLE CHANGE IN THE PATTERN BY NEXT WEEKEND. ONLY MAJOR WEATHER MAKE TO WATCH FOR AT THE MOMENT IS THE SHORTWAVE PASSING THROUGH MONDAY NIGHT/TUESDAY BRINGING SHOWERS TO THE REGION. LOW CONFIDENCE ON EXACT TIMING BUT CONFIDENCE IS INCREASING THAT PRECIP WILL OCCUR. OTHERWISE HIGH PRESSURE WILL PREVAIL WITH TEMPS AT OR BELOW AVERAGE FOR THIS TIME OF YEAR. IN FACT SUNDAY NIGHT AND MID TO LATE NEXT WEEK MAY NEED TO WATCH FOR FROST HEADLINES. DETAILS... MONDAY... A MODIFIED CANADIAN HIGH WILL BUILD INTO NEW ENGLAND DURING THIS PORTION OF THE FORECAST...CRESTING OVER THE REGION ON MONDAY. LOWS ON SUN NIGHT WILL BE QUITE CHILLY FOR SEPTEMBER. ALTHOUGH RECORD COLD IS NOT EXPECTED...WE MAY STILL SEE SOME MIDDLE TO UPPER 30S ACROSS PORTIONS OF SOUTHWEST NH/NORTHWEST MA...WHERE THIS IS A LOW RISK FOR SOME PATCHY FROST IN THE TYPICALLY COOLEST OUTLYING LOCATIONS. FOR MONDAY HIGHS...EVEN WITH FULL SUNSHINE TEMPS WILL ONLY REACH INTO THE MID 60S TO LOWER 70S...SINCE THE SUN ANGLE IS LOW. DRY WEATHER WILL PREVAIL. MONDAY NIGHT INTO TUESDAY... THE NEXT SHOT FOR ANY SHOWERS WILL BE LATE MONDAY NIGHT INTO TUESDAY AS ANOTHER SHORTWAVE MOVES THROUGH THE FLOW. OVERALL GUIDANCE HAS TRENDED TO BE ON THE WETTER SIDE SO CONFIDENCE IS INCREASING THAT PRECIP WILL OCCUR. RIGHT NOW LOOKS AS IF DROUGHT STRICKEN RI AND SE MASS HAVE THE BETTER SHOT FOR THE HIGHER QPF AMOUNTS. ALTHOUGH THE EC DOES HAVE A QPF BULLS-EYE FOR THE REGION...NOTICED THAT THE GFS HAS TICKED UP SO OVER 0.25 TO 0.5 INCHES IS NOT OUT OF THE QUESTION...ESPECIALLY SINCE PWAT VALUES DO NOSE IN AT ABOUT 1.5 INCHES. INSTABILITY LOOKS FAIRLY LIMITED...SO WILL NOT INCLUDE THUNDER IN THE FORECAST AT THIS TIME. HIGHS SHOULD BE IN THE 60S TO AROUND 70. END OF THE WORK WEEK... HIGH PRESSURE FROM CANADA WILL SET UP OVER THE NORTHEAST ON WED INTO FRIDAY. THE GFS BRING AN ARCTIC FRONT ACROSS THE REGION ON WED WHILE THE EC HOLDS IT UP UNTIL THURSDAY NIGHT. EITHER WAY GUIDANCE IS SHOWING 850 MB TEMPS DROPPING BELOW 0C. THIS WILL KEEP TEMPS WELL BELOW AVERAGE...IN THE 60S RESULTING IN CRISP FALL LIKE TEMPS. BECAUSE OF THE DIFFERENCE...WILL CONTINUE WITH A BLEND OF PREV FORECAST AS WELL AS THE ENSEMBLES FOR NOW. EITHER WHICH WAY WE MAY NEED TO BEGIN TO WATCH FOR THE RISK FOR SOME FROST IN SOUTHWEST NH/NORTHWEST MA...WHERE WINDS CAN DECOUPLE. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. OVERNIGHT... MODERATE CONFIDENCE. MAIN CHALLENGE ARE A FEW PATCHES OF STRATOCUMULUS CLOUDS IN 30-35 HUNDRED LAYER. RAP MODEL SEEMS TO HAVE BEST HANDLE SO FAR ON THIS. LIGHT NORTH TO NORTHEAST WINDS EXPECTED TO BECOME MORE FROM THE EAST TO NORTHEAST AFTER DAYBREAK. SATURDAY... MVFR CIGS EXPECTED TO DEVELOP FROM WEST TO EAST AND SOUTH TO NORTH DURING THE AFTERNOON. SCATTERED SHOWERS MOST LIKELY AFTER 20Z WITH SOME MOVING FROM WEST TO EAST AND A SECOND AREA SOUTHWEST TO NORTHEAST TOWARD THE CAPE AND ISLANDS. SAT NIGHT... MVFR CIGS IN SCATTERED SHOWERS WITH PATCHES OF IFR CIGS POSSIBLE SE COASTAL AREAS. CONDITIONS IMPROVING TO VFR BY 03Z WEST AND BY 06Z EAST. MODEST NNE WIND DEVELOPS 06Z- 12Z WITH GUSTS UP TO 20-25 KT POSSIBLE E COASTAL AREAS. KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. CIGS BKN030 POSSIBLE A FEW HOURS ON EITHER SIDE OF SUNRISE...THEN PROBABLY A PERIOD OF VFR MID TO LATE MORNING BEFORE CIGS LOWERING TO MVFR RANGE BY MID OR LATE AFTERNOON. SCATTERED SHOWERS MAY LOWER VSBYS TO MVFR THRESHOLDS FOR A TIME LATE AFTERNOON/EARLY EVENING. GREATEST RISK OF SHOWERS 20Z SAT THRU 03Z SUN. CONDITIONS IMPROVING AFTER 03Z SUN. KBDL TERMINAL...MODERATE TO HIGH CONFIDENCE. GREATEST RISK OF SHOWERS 18Z SAT THRU 00Z SUNDAY WITH A PERIOD OR TWO OF MVFR CIGS AND VSBYS POSSIBLE. OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...HIGH CONFIDENCE. MAINLY VFR CONDITIONS OVER THIS TIME...EXCEPT FOR A PERIOD OF MVFR- IFR CONDITIONS LATE MON NIGHT/TUE IN A ROUND OF SHOWERS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. FORECAST CONFIDENCE IS MODERATE TO HIGH THROUGH SUNDAY. OVERNIGHT...LIGHT EAST TO NORTHEAST WINDS...DRY WEATHER AND GOOD VSBY. SATURDAY...GENERALLY LIGHT EASTERLY WINDS. ONE AREA OF LOW PRES TRACKS NE INTO NY STATE AND ANOTHER WEAK LOW FORMS OFF THE NJ COAST. CHANCE OF SHOWERS LATE IN THE DAY WITH A LOW RISK OF THUNDER WELL SOUTH OF NEW ENGLAND. SAT NIGHT...WEAK LOW PRES MOVES NE ACROSS GEORGES BANK. A MODEST NORTH WIND DEVELOPS WITH A CHANCE OF GUSTS TO NEAR 25 KT LATE. SCATTERED SHOWERS DURING THE EVENING GIVES WAY TO DRY WEATHER AND GOOD VSBY. OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY.... MONDAY INTO TUE MORNING...MODERATE TO HIGH CONFIDENCE. HIGH PRESSURE NEARBY WILL RESULT IN A WEAK PRESSURE GRADIENT KEEPING WINDS/SEAS BELOW SCA THRESHOLDS. TUESDAY AFTERNOON INTO WEDNESDAY...MODERATE CONFIDENCE. MAY SEE SOME MARGINAL SCA WINDS/SEAS ACROSS THE OUTER-WATERS BEHIND A COLD FRONT/LOW PRESSURE SYSTEM IN THE COOL AIR ADVECTION PATTERN. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...NOCERA/DUNTEN NEAR TERM...FRANK/NOCERA/THOMPSON SHORT TERM...NOCERA LONG TERM...DUNTEN AVIATION...NOCERA/DUNTEN/THOMPSON MARINE...NOCERA/DUNTEN/THOMPSON
AREA FORECAST DISCUSSION
NWS TAUNTON MA
158 AM EDT SAT SEP 13 2014 .SYNOPSIS... HIGH PRESSURE DOMINATES OVERNIGHT. A QUICK MOVING WEATHER SYSTEM WILL BRING SCATTERED SHOWERS TO THE AREA LATE SATURDAY AFTERNOON AND EARLY EVENING. HIGH PRESSURE BRINGS DRY WEATHER WITH SLIGHTLY BELOW NORMAL TEMPERATURES SUNDAY INTO MONDAY. THE NEXT COLD FRONT WILL LIKELY BRING A PERIOD OF SHOWERS LATE MONDAY NIGHT INTO TUESDAY. MAINLY DRY WEATHER EXPECTED NEXT WEDNESDAY THROUGH FRIDAY WITH SLIGHTLY BELOW NORMAL TEMPERATURES CONTINUING. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 130 AM UPDATE... ADJUSTED SKY COVER GRIDS BASED ON LATEST OBSERVATIONS AND SATELLITE PICTURES. RAP SEEMS TO HAVE BEST HANDLE ON PATCHES OF STRATOCUMULUS. ADJUSTED TEMPERATURES STILL A LITTLE COOLER IN SE ZONES BASED ON LATEST OBSERVED TRENDS. 1015 PM UPDATE... QUIET NIGHT WITH LITTLE CHANGE NEEDED IN FORECAST. DID LOWER HOURLY AND MIN TEMPS FOR PORTIONS OF SE MA AND MARTHAS VINEYARD TO ACCOUNT FOR CURRENT TRENDS AND CLIMATOLOGY. KEPT POP NEAR ZERO PERCENT THROUGH 8 AM AND JUST MADE A FEW TWEAKS WITH THE SKY COVER TO BE CONSISTENT WITH CURRENT TRENDS. 630 PM UPDATE... STRATO-CUMULUS CLOUDS HAVE DISSIPATED EARLY THIS EVENING ACROSS THE CAPE AND ISLANDS. OTHERWISE...MAINLY CLEAR SKIES WERE IN PLACE EARLY THIS EVENING OTHER THAN A TOUCH OF HIGH CLOUDINESS. IDEAL SEP WEATHER ACROSS THE REGION THROUGH THE EVENING WITH MAINLY CLEAR SKIES...COMFORTABLE TEMPS AND LIGHT WINDS. AFTER SUNSET...TEMPS WILL FALL FAIRLY QUICKLY GIVEN DRY ATMOSPHERE...CLEAR SKIES AND LIGHT WINDS. MANY LOCATIONS WILL DIP INTO THE MU40S TONIGHT INCLUDING PLACES SUCH AS MARTHAS VINEYARD... NORWOOD AND OTHER INTERIOR EASTERN MA LOCATIONS. ALSO WESTERN MA AND SOUTHWEST NH SHOULD FALL INTO THE MU40S. ELSEWHERE MINS WILL BE IN THE LOW TO MID 50S. TRICKY PART TO THE FORECAST WILL BE IF SOME LOW CLOUDS ARE ABLE TO DEVELOP NEAR THE COAST TOWARD DAYBREAK. THESE CLOUDS MAY REAPPEAR TOWARD SUNRISE GIVEN BLYR COOLING OVERNIGHT. THUS COULD SEE SKIES BECOME PARTLY TO MOSTLY CLOUDY TOWARD DAYBREAK OVER EASTERN MA AND POSSIBLY INTO RI...BUT CONFIDENCE IS LOW. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/... SATURDAY... DRY TO START THE DAY BUT QUICK MOVING NORTHERN STREAM SHORT WAVE TROUGH APPROACHES FROM THE WEST. TWO AREAS OF SHOWERS WILL TRACK ACROSS THE NORTHEAST. FIRST BATCH WILL BE OVER NY STATE AND NORTHERN NEW ENGLAND WITH PARENT LOW AND ACCOMPANYING LOW TO MID LEVEL JET. A SECOND AREA OF SHOWERS WILL TRACK SOUTH OF NEW ENGLAND AS LAST NIGHT/S FRONTAL BOUNDARY LIFTS NORTHWARD WITH SECONDARY LOW PRES DEVELOPING ON THE FRONT IN RESPONSE TO RRQ OF THE UPPER JET STREAK. THIS YIELDS LIKELY POPS ACROSS CAPE COD AND THE ISLANDS WITH CHANCE POPS ELSEWHERE FOR SCATTERED SHOWERS. GREATEST RISK OF SHOWERS IS SOMEWHERE BETWEEN 4-8 PM. COULD BE SOME HEAVIER SHOWERS ALONG SOUTH COAST AND OFFSHORE AS PWATS CLIMB TO 2 INCHES /+2 STD FROM CLIMO/. HOWEVER INSTABILITY ALOFT AND AT THE SURFACE IS LACKING SO HEAVIER SHOWERS AND THUNDER MAY BE WELL OFFSHORE. SYSTEM IS VERY PROGRESSIVE SO NOT EXPECTING A SOAKING RAIN. IN FACT SOME LOCATIONS MAY ONLY SEE A TRACE OF RAINFALL WITH OTHER LOCATIONS SUCH AS WELL INLAND AND ALONG THE SOUTH COAST PERHAPS A TENTH OR TWO. TEMPS A FEW DEGS COOLER THAN TODAY GIVEN THE COOLER START ALONG WITH INCREASING CLOUDS AND LIGHT ONSHORE WINDS. SATURDAY NIGHT... QUICK MOVING SYSTEM EXITS THE REGION BETWEEN 00Z WEST TO PERHAPS 03Z CAPE COD. EXPECT DECREASING CLOUDS AND DRIER AIR TO OVERSPREAD THE REGION. NORTHERLY WINDS WILL BECOME GUSTY LATE AT NIGHT AND TOWARD SUNRISE SUNDAY WITH A FEW GUSTS UP TO 25 MPH POSSIBLE. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... HIGHLIGHTS... * DRY WITH SLIGHTLY BELOW NORMAL TEMPS SUN/MON * LOW RISK OF PATCHY FROST SUN NIGHT ACROSS DISTANT INTERIOR * A PERIOD OF SHOWERS LIKELY LATE MON NIGHT/TUE * DRY WEATHER/SLIGHTLY BELOW NORMAL TEMPS NEXT WED-FRI DETAILS... SUNDAY AND MONDAY... LARGE HIGH PRESSURE WILL BE ANCHORED OVER SOUTHERN NEW ENGLAND SUN AND MON. THIS WILL RESULT IN DRY WEATHER WITH SLIGHTLY BELOW NORMAL HIGH TEMPS. HIGHS SUN AND MON WILL BE IN THE 60S...TO LOWER 70S. LOWS SUN NIGHT WILL BE QUITE CHILLY FOR MID SEPTEMBER. MAY SEE SOME MIDDLE TO UPPER 30S ACROSS PORTIONS OF SOUTHWEST NH/NORTHWEST MA... WHERE THIS IS A LOW RISK FOR SOME PATCHY FROST IN THE TYPICALLY COOLEST OUTLYING LOCATIONS. MOST OTHER AREAS WILL SEE LOWS IN THE 40S. MONDAY NIGHT AND TUESDAY... A POTENT SHORTWAVE/COLD FRONT WILL BE APPROACHING SOUTHERN NEW ENGLAND LATE MON NIGHT INTO TUE. THIS SHOULD RESULT IN A PERIOD OF RAIN SHOWERS...BUT EXACT TIMING IS UNCERTAIN AT THIS POINT. ITS POSSIBLE WE COULD EVEN SEE A PERIOD OF HEAVY RAIN IF THE MORE AMPLIFIED ECMWF MODEL IS CORRECT...BUT GFS/GGEM ARE A TAMER WITH THE SHORTWAVE SO THAT IS UNCERTAIN. INSTABILITY LOOKS FAIRLY LIMITED...SO WILL NOT INCLUDE THUNDER IN THE FORECAST AT THIS TIME. HIGHS SHOULD BE IN THE 60S TO AROUND 70. WEDNESDAY THROUGH FRIDAY... HIGH PRESSURE BUILDS IN BEHIND THE COLD FRONT WED INTO FRI. THIS SHOULD RESULT IN MAINLY DRY WEATHER WITH SLIGHTLY BELOW NORMAL TEMPS FOR THE END OF THE WORK WEEK. WE MAY HAVE TO DEAL WITH THE RISK FOR SOME FROST IN SOUTHWEST NH/NORTHWEST MA...WHERE WINDS CAN DECOUPLE. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. OVERNIGHT... MODERATE CONFIDENCE. MAIN CHALLENGE ARE A FEW PATCHES OF STRATOCUMULUS CLOUDS IN 30-35 HUNDRED LAYER. RAP MODEL SEEMS TO HAVE BEST HANDLE SO FAR ON THIS. LIGHT NORTH TO NORTHEAST WINDS EXPECTED TO BECOME MORE FROM THE EAST TO NORTHEAST AFTER DAYBREAK. SATURDAY... MVFR CIGS EXPECTED TO DEVELOP FROM WEST TO EAST AND SOUTH TO NORTH DURING THE AFTERNOON. SCATTERED SHOWERS MOST LIKELY AFTER 20Z WITH SOME MOVING FROM WEST TO EAST AND A SECOND AREA SOUTHWEST TO NORTHEAST TOWARD THE CAPE AND ISLANDS. SAT NIGHT... MVFR CIGS IN SCATTERED SHOWERS WITH PATCHES OF IFR CIGS POSSIBLE SE COASTAL AREAS. CONDITIONS IMPROVING TO VFR BY 03Z WEST AND BY 06Z EAST. MODEST NNE WIND DEVELOPS 06Z- 12Z WITH GUSTS UP TO 20-25 KT POSSIBLE E COASTAL AREAS. KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. CIGS BKN030 POSSIBLE A FEW HOURS ON EITHER SIDE OF SUNRISE...THEN PROBABLY A PERIOD OF VFR MID TO LATE MORNING BEFORE CIGS LOWERING TO MVFR RANGE BY MID OR LATE AFTERNOON. SCATTERED SHOWERS MAY LOWER VSBYS TO MVFR THRESHOLDS FOR A TIME LATE AFTERNOON/EARLY EVENING. GREATEST RISK OF SHOWERS 20Z SAT THRU 03Z SUN. CONDITIONS IMPROVING AFTER 03Z SUN. KBDL TERMINAL...MODERATE TO HIGH CONFIDENCE. GREATEST RISK OF SHOWERS 18Z SAT THRU 00Z SUNDAY WITH A PERIOD OR TWO OF MVFR CIGS AND VSBYS POSSIBLE. OUTLOOK...SUNDAY THROUGH WEDNESDAY...MODERATE TO HIGH CONFIDENCE. MAINLY VFR CONDITIONS OVER THIS TIME...EXCEPT FOR A PERIOD OF MVFR-IFR CONDITIONS LATE MON NIGHT/TUE IN A ROUND OF SHOWERS AND PERHAPS SOME LOW CLOUDS/FOG PATCHES. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. FORECAST CONFIDENCE IS MODERATE TO HIGH THROUGH SUNDAY. OVERNIGHT...LIGHT EAST TO NORTHEAST WINDS...DRY WEATHER AND GOOD VSBY. SATURDAY...GENERALLY LIGHT EASTERLY WINDS. ONE AREA OF LOW PRES TRACKS NE INTO NY STATE AND ANOTHER WEAK LOW FORMS OFF THE NJ COAST. CHANCE OF SHOWERS LATE IN THE DAY WITH A LOW RISK OF THUNDER WELL SOUTH OF NEW ENGLAND. SAT NIGHT...WEAK LOW PRES MOVES NE ACROSS GEORGES BANK. A MODEST NORTH WIND DEVELOPS WITH A CHANCE OF GUSTS TO NEAR 25 KT LATE. SCATTERED SHOWERS DURING THE EVENING GIVES WAY TO DRY WEATHER AND GOOD VSBY. OUTLOOK...SUNDAY THROUGH WEDNESDAY.... SUNDAY...MODERATE TO HIGH CONFIDENCE. MAY HAVE SOME MARGINAL SCA NORTHERLY WIND GUSTS/SEAS ACROSS THE EASTERN WATERS SUN MORNING IN THE COOL ADVECTION PATTERN. WINDS/SEAS SHOULD DIMINISH SUN AFTERNOON AS PRESSURE GRADIENT WEAKENS. MONDAY INTO TUE MORNING...MODERATE TO HIGH CONFIDENCE. HIGH PRESSURE NEARBY WILL RESULT IN A WEAK PRESSURE GRADIENT KEEPING WINDS/SEAS BELOW SCA THRESHOLDS. TUESDAY AFTERNOON INTO WEDNESDAY...MODERATE CONFIDENCE. MAY SEE SOME MARGINAL SCA WINDS/SEAS ACROSS THE OUTER-WATERS BEHIND A COLD FRONT/LOW PRESSURE SYSTEM IN THE COOL AIR ADVECTION PATTERN. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...FRANK/NOCERA NEAR TERM...FRANK/NOCERA/THOMPSON SHORT TERM...NOCERA LONG TERM...FRANK AVIATION...FRANK/NOCERA/THOMPSON MARINE...FRANK/NOCERA/THOMPSON
AREA FORECAST DISCUSSION
NWS MIAMI FL
431 AM EDT SAT SEP 13 2014 .SHORT TERM...(TODAY-MONDAY) RECENTLY ANIMATED WATER VAPOR LOOP SHOWED AN UPPER LOW CENTERED OVER SOUTH FLORIDA SLOWLY TRACKING WESTWARD AND A RIDGE AXIS ORIENTED FROM EAST TO WEST ACROSS THE NORTHERN GULF COAST STATES. PLENTY OF DEEP LAYER MOISTURE EAST OF THIS UPPER LOW COMBINED WITH UPPER-LEVEL DIVERGENCE WILL CONTINUE TO SUPPORT WIDESPREAD RAINFALL TODAY ...ESPECIALLY ALONG THE SOUTHEAST COAST AND ACROSS THE ATLANTIC WATERS THROUGH THE MORNING HOURS. THE LATEST HRRR MODEL RUN APPEARS TO HAVE INITIALIZED WELL WITH THE CURRENT RADAR TRENDS AND GENERALLY INDICATES THIS MORNING ACTIVITY CONTINUING ACROSS THE EASTERN AREAS INCLUDING PALM BEACH, BROWARD AND MIAMI-DADE BEFORE SHIFTING INLAND AND TOWARD THE GULF COAST THROUGH THE MID TO LATE AFTERNOON/EARLY EVENING PERIOD. THIS SOLUTION MAKES SENSE WITH THE UPPER LOW SHIFTING WESTWARD AND LIGHT TO MODERATE SOUTHEAST LOW- LEVEL FLOW CONTINUING. THIS PATTERN WILL KEEP THE POTENTIAL FOR LOCALIZED FLOODING UP THROUGH THIS EVENING...ESPECIALLY OVER THE AREAS THAT ARE ALREADY SATURATED FROM EARLIER RAINFALL (AREAS HAVE RECEIVED 2-4 INCHES WITH HIGHER AMOUNTS UP TO 7" JUST INLAND OF BOCA RATON OVER THE PAST 24-36 HRS). MODEL SOUNDINGS SUPPORT THE ACTIVITY TAPERING OFF OVER THE FAR SOUTHEASTERN AREAS OR TOWARD MIAMI THROUGH THE MORNING AND AFTERNOON HOURS WITH MAINLY SATURATED PROFILES ABOVE A SLIGHTLY DRIER LAYER FROM THE SURFACE TO 700MB. AS A RESULT...MAXIMUM TEMPERATURES HAVE BEEN SLIGHTLY UNDERCUT BY A FEW DEGREES COMPARED TO GUIDANCE...MAINLY DUE TO PLENTY OF CLOUD COVERAGE ANTICIPATED. IF THIS COVERAGE BEGINS TO BREAK THROUGH THE DAY...TEMPERATURES WILL NEED TO BE ADJUSTED ACCORDINGLY. THE MOIST TREND WITH SOUTHEAST FLOW WILL PERSIST THROUGH SUNDAY BEFORE SOME DRIER AIR MOVES IN FROM THE WEST AND THE RIDGE BUILDS BACK ACROSS THE REGION INTO THE UPCOMING WEEK. /85 .LONG TERM (TUESDAY-FRIDAY)... THE LATEST EXTENDED GUIDANCE REMAINS IN DECENT AGREEMENT ON THE LARGE SCALE AND GENERALLY INDICATES FALLING UPPER HEIGHTS IN RESPONSE TO A DEEPENING UPPER TROUGH ACROSS THE REGION. A FRONTAL BOUNDARY IS PROJECTED TO SHIFT SOUTHWARD AND STALL NORTH OF THE AREA THROUGH THE SECOND HALF OF THE WEEK. THE ECMWF SEEMS TO BE THE MORE BULLISH SOLUTION AND SHOWS THE MOISTURE AXIS ASSOCIATED WITH THIS BOUNDARY PROGRESSING FARTHER SOUTH THAN THE GFS/GFS ENSEMBLE MEAN WITH SSW LOW-LEVEL FLOW SETTING UP OVER THE AREA BY THURSDAY. THE COMBINATION OF THE FRONT AND FALLING UPPER HEIGHTS ALONG WITH SSW LOW-LEVEL FLOW WOULD FAVOR MUCH OF THE RAINFALL SETTING UP OVER THE EAST COAST/METRO AREAS BY THURSDAY. /85 && .AVIATION... A LARGE AREA OF SHOWERS AND THUNDERSTORMS OVER THE ATLANTIC WATERS WERE DEVELOPING ON THE NORTHEAST SIDE OF THE MID/UPPER LEVEL VORTICITY MOVING WEST ACROSS THE FLORIDA STRAITS. THESE SHOWERS/STORMS WERE MOVING QUICKLY TO THE NORTHWEST TOWARDS THE BROWARD AND MIAMI-DADE TAF SITES...AND THEY MAY MOVE OVER THE TAF SITES THROUGH THE EARLY MORNING HOURS. BRIEF MVFR/IFR CONDITIONS AND GUSTY WINDS UP TO 30 KNOTS ARE POSSIBLE. THE AREA OF LOW PRESSURE OVER THE SOUTHEAST GULF AND THE UPPER LEVEL LOW WILL CONTINUE TO MOVE WEST TODAY AND HAVE LESS OF AN INFLUENCE OVER THE REGION THROUGHOUT THE DAY. THIS COMBINED WITH THE OVERNIGHT CONVECTION MAY LIMIT SHOWER/STORM DEVELOPMENT FOR THE EAST COAST METRO AREAS DURING THE DAY. HOWEVER...DEEP MOISTURE IN THE SOUTHEAST LOW LEVEL FLOW WILL CONTINUE...SO KEPT VCTS IN FOR THE TAF SITES. AT KAPF...SHOWER AND STORM DEVELOPMENT IS FORECAST TO BECOME MORE LIKELY AS THE DAY PROGRESSES...AS THE INFLUENCE OF THE UPPER LOW INCREASES. LIGHT WINDS WILL CONTINUE THROUGH THE OVERNIGHT HOURS OUTSIDE OF SHOWERS AND STORMS...AND THEN BECOME SOUTHEAST AROUND 10 KNOTS DURING THE DAY. /84 && .MARINE... AN UPPER LOW WILL KEEP THE RAIN CHANCES IN THE FORECAST ACROSS THE MARINE AREAS THROUGH THE REMAINDER OF THE WEEKEND WITH LIGHT TO MODERATE SOUTHEAST WINDS CONTINUING. WINDS AND SEAS WILL BE LOCALLY HIGHER IN AND AROUND HEAVIER SHOWERS AND STORMS. HIGH PRESSURE WILL BUILD BACK ACROSS THE REGION THROUGH THE FIRST HALF OF THE UPCOMING WEEK WITH SOUTHEAST WINDS CONTINUING. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 87 76 87 76 / 40 30 50 30 FORT LAUDERDALE 84 77 87 79 / 50 40 60 20 MIAMI 85 77 87 78 / 50 40 60 20 NAPLES 87 75 89 76 / 70 30 60 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION...85/AG AVIATION....84/AK
AREA FORECAST DISCUSSION
NWS MIAMI FL
205 AM EDT SAT SEP 13 2014 .AVIATION... A LARGE AREA OF SHOWERS AND THUNDERSTORMS OVER THE ATLANTIC WATERS WERE DEVELOPING ON THE NORTHEAST SIDE OF THE MID/UPPER LEVEL VORTICITY MOVING WEST ACROSS THE FLORIDA STRAITS. THESE SHOWERS/STORMS WERE MOVING QUICKLY TO THE NORTHWEST TOWARDS THE BROWARD AND MIAMI-DADE TAF SITES...AND THEY MAY MOVE OVER THE TAF SITES THROUGH THE EARLY MORNING HOURS. BRIEF MVFR/IFR CONDITIONS AND GUSTY WINDS UP TO 30 KNOTS ARE POSSIBLE. THE AREA OF LOW PRESSURE OVER THE SOUTHEAST GULF AND THE UPPER LEVEL LOW WILL CONTINUE TO MOVE WEST TODAY AND HAVE LESS OF AN INFLUENCE OVER THE REGION THROUGHOUT THE DAY. THIS COMBINED WITH THE OVERNIGHT CONVECTION MAY LIMIT SHOWER/STORM DEVELOPMENT FOR THE EAST COAST METRO AREAS DURING THE DAY. HOWEVER...DEEP MOISTURE IN THE SOUTHEAST LOW LEVEL FLOW WILL CONTINUE...SO KEPT VCTS IN FOR THE TAF SITES. AT KAPF...SHOWER AND STORM DEVELOPMENT IS FORECAST TO BECOME MORE LIKELY AS THE DAY PROGRESSES...AS THE INFLUENCE OF THE UPPER LOW INCREASES. LIGHT WINDS WILL CONTINUE THROUGH THE OVERNIGHT HOURS OUTSIDE OF SHOWERS AND STORMS...AND THEN BECOME SOUTHEAST AROUND 10 KNOTS DURING THE DAY. && .PREV DISCUSSION... /ISSUED 944 PM EDT FRI SEP 12 2014/ UPDATE... ONLY MADE SOME MINOR ADJUSTMENTS TO THE POP GRIDS THIS EVENING. COULD HAVE LOWERED THEM EVEN MORE THAN I DID, BUT THESE TROPICAL TYPE SMALL LOW LEVEL CIRCULATIONS CAN BEGIN TO DEVELOP CONVECTION AT ANY TIME GIVEN THE SOUTHEASTERLY FLOW ON THE EAST SIDE WITH DEEP TROPICAL AIRMASS. SO EVEN THOUGH NOT MUCH GOING ON AT THE CURRENT TIME, WAS A LITTLE HESITANT IN MAKING TOO DRASTIC OF A CUT IN THE POPS. THE HRRR KEEPS THE ACTION QUIET SO LATER UPDATES MAY BE NEEDED TO LOWER CHANCES MORE IF TRENDS DICTATE. KOB PREV DISCUSSION... /ISSUED 739 PM EDT FRI SEP 12 2014/ AVIATION... LOW PRESSURE CENTERED JUST NORTH OF NAPLES THIS EVENING WILL CONTINUE DRIFTING WEST INTO THE GULF OF MEXICO...BUT WILL BE THE MAJOR INFLUENCE ON SOUTH FLORIDA WEATHER THROUGH THE TAF PERIOD. APPEARS TSRA THREAT OVERNIGHT IS MINIMAL...SO ELECTED TO HAVE VCSH IN FORECAST INTO SATURDAY MORNING. BY 15Z...SCATTERED/NUMEROUS SHOWERS/TSTMS EXPECTED...HANDLED NOW BY VCTS BUT TEMPO GROUPS MAY BE NEEDED ONCE TIMING/COVERAGE BECOME MORE CERTAIN. ESE WINDS WILL DIMINISH TO 5 KTS OR LESS TONIGHT...THEN INCREASE TO 10-15 KTS BY SAT AFTN. PREV DISCUSSION... /ISSUED 344 PM EDT FRI SEP 12 2014/ DISCUSSION... RECENT WATER VAPOR IMAGERY AND THE LATEST GUIDANCE INDICATES AN UPPER LEVEL LOW JUST TO THE NORTH OF THE NORTHERN BAHAMAS AND IS FORECAST TO RETROGRADE WESTWARD TONIGHT INTO SATURDAY. ELEVATED CHANCES OF SHOWERS AND THUNDERSTORMS ARE FORECAST ACROSS THE REGION TONIGHT INTO SATURDAY. AS THE SURFACE LOW CONTINUES TO TRACK WESTWARD TONIGHT...IT IS FORECAST TO ENTER THE GULF WATERS WITH LOW LEVEL SOUTHEASTERLY WINDS FORECAST TO CONTINUE BRINGING IN DEEP TROPICAL MOISTURE INTO THE REGION TONIGHT INTO SATURDAY. FOR TONIGHT...THE AFOREMENTIONED UPPER LEVEL LOW IS FORECAST TO DRIFT WESTWARD WITH 500 HPA VORTICITY FORECAST TO PASS ACROSS THE REGION TONIGHT INTO SATURDAY. THUS THE INGREDIENTS FOR ADDITIONAL SHOWERS AND THUNDERSTORMS WILL CONTINUE TONIGHT INTO SATURDAY WITH ELEVATED POP`S INDICATED IN THE FORECAST. FOR SATURDAY...WILE THE UPPER LEVEL LOW MAY BE LESS OF A FACTOR AS IT IS FORECAST TO CONTINUE MOVING WESTWARD...THE SURFACE LOW IS FORECAST TO BE IN THE EASTERN GULF WITH LOW LEVEL SOUTHEASTERLY WINDS CONTINUING TO ADVECT ADDITIONAL DEEP MOISTURE INTO THE REGION. NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS ARE FORECAST FOR SATURDAY AFTERNOON AND EARLY EVENING HOURS. BY SUNDAY TROPICAL MOISTURE IS FORECAST TO REMAIN ACROSS THE REGION WITH DAY TIME HEATING LIKELY TO DEVELOP AFTERNOON SHOWERS AND THUNDERSTORMS. THE EXTENDED GUIDANCE INDICATES SOME RELATIVELY DRIER AIR ENTERING THE REGION EARLY NEXT WEEK. MARINE... WINDS ARE FORECAST TO BE FROM 10 TO 15 KNOTS THROUGH SATURDAY THEN DECREASING INTO SUNDAY TO AROUND 10 KNOTS. SEAS 2 TO 3 FEET POSSIBLE TODAY INTO SATURDAY THEN DECREASING TO 2 FEET OR LESS BY SUNDAY. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 87 76 87 76 / 60 40 50 20 FORT LAUDERDALE 87 77 88 79 / 60 50 50 30 MIAMI 88 77 88 78 / 60 40 40 20 NAPLES 88 74 89 76 / 70 40 60 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...85/AG LONG TERM....85/AG AVIATION...84/AK
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1207 AM CDT SAT SEP 13 2014 .AVIATION... FOR THE 13/00Z TAFS...SCT SHWRS PERSIST GENERALLY ALONG AND S OF THE I-20 CORRIDOR BUT RADAR LOOPS OVER THE LAST HOUR INDICATE PRECIP IS BEGINNING TO DISSIPATE. HAVE INCLUDED SOME MENTION OF RAIN AT A FEW OF THE TAFS SITES FOR THE ONGOING ACTIVITY. CIGS ARE MVFR/IFR...GENERALLY AROUND OR BELOW 1000 KFT. ONLY A VERY SLIGHT IMPROVEMENT IS ANTICIPATED THROUGH THE REMAINDER OF THE TAF PERIOD AS CIGS LIFT SOMEWHAT BUT WILL LIKELY NOT LIFT ABOVE MVFR. POST- FRONTAL PRESSURE GRADIENT REMAINS TIGHT AND NLY WINDS WILL PERSIST AROUND 10 KTS WITH A FEW HIGHER GUSTS BUT SPEEDS SHOULD GRADUALLY DIMINISH AND EVENTUALLY DROP TO AROUND 5 KTS AFTER 14/00Z AS A SFC HIGH BUILDS INTO THE AREA. /09/ && .PREV DISCUSSION... /ISSUED 1015 PM CDT FRI SEP 12 2014/ DISCUSSION... COLD FRONT SOUTH OF INTERSTATE 20 AND NEARING THE SOUTHERN PARTS OF EAST AND NORTHEAST TEXAS ACROSS LOWER PARTS OF NORTHWEST AND NORTH CENTRAL LOUISIANA LATE THIS EVENING. RAIN AND EMBEDDED HEAVIER SHOWERS CONTINUED ALONG AND IN WAKE OF THE COLD FRONT AS MOISTURE LIFTS NEAR THE BOUNDARY AND COOLS IN THE COOLER AIR TO THE RADAR OF THE BOUNDARY. HAVE REMOVED THUNDERSTORMS FROM THE WORDING OF THE ZONES FOR THE REST OF TONIGHT AND INTO TOMORROW. SOME ISOLATED THUNDERSTORMS MAY OCCUR BUT MOST LOCATIONS WILL NOT HAVE THUNDERSTORMS. RAIN WILL TAPER OFF FROM NORTHWEST TO SOUTHEAST. ADJUSTED THE TEMPERATURES LOWER FOR PARTS OF EAST AND NORTHEAST TEXAS AND SOUTHEAST OKLAHOMA...WHERE COLD AIR WILL MORE PRONE TO ENTER THE REGION. /06/ PREV DISCUSSION... /ISSUED 348 PM CDT FRI SEP 12 2014/ DISCUSSION... OUR WEAK COLD FRONT REMAINS STATIONARY JUST S OF THE I-20 CORRIDOR OF E TX/N LA THIS AFTERNOON...WITH A LARGE SUCKER HOLE RECENTLY OPENING UP ACROSS NW LA. TEMPS IN THESE AREAS HAVE WARMED INTO THE LOWER/MID 80S THIS AFTERNOON...BUT TEMPS REMAIN MUCH COOLER UNDER THE LOW STRATUS FARTHER W AND N. AS EXPECTED...SCT CONVECTION HAS DEVELOPED ALONG THE FRONTAL ZONE OVER DEEP E TX...WITH THE WEAK SEABREEZE APPROACHING THIS AREA AS WELL AS WCNTRL LA FROM SE TX/SW LA. BELIEVE THAT THIS CONVECTION WILL CONTINUE THROUGH A PORTION OF THIS EVENING BEFORE DIMINISHING WITH THE LOSS OF HEATING/INSTABILITY...WITH THE FRONTAL BNDRY EXPECTED TO SLOWLY DRIFT BACK S ACROSS THIS AREA AND THE SRN SECTIONS OF NCNTRL LA THIS EVENING/OVERNIGHT. THE HRRR AND TO SOME EXTENT...THE 12Z WRF DOES INDICATE THE ONGOING CONVECTION POSSIBLY BUILDING BACK A LITTLE FARTHER NNE TO NEAR/JUST S OF THE I-20 CORRIDOR OF E TX/NW LA THIS EVENING...WITH ONLY ISOLATED -SHRA EXPECTED FARTHER N CLOSER TO THE WEAK 850MB TROUGH AS IT REMAINS JUST N OF THE REGION OVER SE OK/WRN AND CNTRL AR. DID MAINTAIN HIGH CHANCE POPS FOR AREAS NEAR/S OF THE FRONT THIS EVENING...LOWERING POPS A TAD LATE AS THE CONVECTION SHOULD WANE ONCE OVERALL FORCING WEAKENS. SHOULD SEE A WIDE RANGE IN MIN TEMPS OVERNIGHT GIVEN THE SHALLOW NATURE OF THE POST-FRONTAL AIR MASS...WITH TEMPS POSSIBLY FALLING INTO THE UPPER 50S OVER SE OK/SW AR. THE WEAK COLD FRONT IS EXPECTED TO NEAR THE COAST AROUND 12Z SATURDAY...WITH THE POST-FRONTAL STRATUS HOLDING TOUGH THROUGH THE DAY. GIVEN THE DEPTH OF THE MOISTURE IN PLACE...DID INSERT SLIGHT CHANCE POPS AREAWIDE SATURDAY AS ANY WEAK FORCING WILL EASILY RESULT IN -SHRA DEVELOPMENT...WITH DAYTIME TEMPS ONLY RISING 10 DEGREES OR SO FROM THE MORNING LOWS. THE LOW STRATUS SHOULD BEGIN TO SLOWLY LIFT SUNDAY...POSSIBLY SCATTERING OUT IN THE AFTERNOON OVER PORTIONS OF THE REGION. THIS SHOULD RESULT IN MODERATING TEMPS...ALTHOUGH SFC RIDGING IN PLACE WILL MAINTAIN ABNORMALLY LOW DEWPOINTS AND COMFORTABLE RH/S FOR THIS TIME OF YEAR. SHOULD BEGIN TO SEE A RETURN OF HIGHER RH/S BY TUESDAY AS THE BROAD UPPER LEVEL LOW/TROPICAL WAVE...NOW OVER SRN FL...BEGINS TO SHIFT W ACROSS THE GULF OF MX THIS WEEKEND AND POSSIBLY IMPACT THE TX COAST. ATTM...ENOUGH SHEAR ALOFT SHOULD KEEP THIS SYSTEM FROM INTENSIFYING THIS WEEKEND AND EARLY NEXT WEEK...ALTHOUGH IT WILL HELP ENHANCE THE SEABREEZE AS IT MOVES INLAND ACROSS SE AND DEEP E TX/SRN AND CNTRL LA TUESDAY. IN ADDITION...A SHORTWAVE IN THE NW FLOW ALOFT WILL DROP SE ACROSS THE REGION TUESDAY AS WELL...WHICH COULD FURTHER ENHANCE FORCING OVER THE SRN SECTIONS OF THE REGION. HAVE INCREASED POPS TO MID CHANCE S OF I-20 TUESDAY...WITH CONVECTION DIMINISHING TUESDAY NIGHT/WEDNESDAY AS DRIER AIR ALOFT MIXES SE IN WAKE OF THIS SHORTWAVE. A DRY NW FLOW LOOKS TO PERSIST THROUGHOUT THE REMAINDER OF THE WEEK AS UPPER LEVEL RIDGING BUILDS OVER THE DESERT SW AND THE ROCKIES. TEMPS SHOULD BE NEAR CLIMO THROUGH THE PERIOD AS WELL. PRELIMS TO FOLLOW BELOW... 15 && .PRELIMINARY POINT TEMPS/POPS... SHV 64 76 61 85 66 / 30 20 10 10 10 MLU 64 79 61 84 65 / 50 20 10 10 10 DEQ 58 71 57 79 62 / 20 10 10 10 10 TXK 60 73 58 81 63 / 20 20 10 10 10 ELD 61 74 57 81 62 / 30 20 10 10 10 TYR 62 75 61 85 68 / 30 20 10 10 10 GGG 64 76 61 85 66 / 40 20 10 10 10 LFK 67 80 64 88 68 / 60 30 10 10 10 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...NONE. LA...NONE. OK...NONE. TX...NONE. && $$ 09
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1127 PM CDT Fri Sep 12 2014 .UPDATE: Issued at 1027 PM CDT Fri Sep 12 2014 Issued at 620 PM CDT Fri Sep 12 2014 cloud cover continues to slowly recede southeastward across north- central Missouri. Light to moderate drizzle still continues over much of central Missouri into southwest and central Illinois. Light to moderate drizzle will continue over parts of central and much of east-central - southwest illinois through early Saturday morning. Cloud cover will slowly recede southward with time. But will still continue to linger beyond 0900 UTC. Surface winds will be dimishing to 5 kts after 0600 UTC. temperatures will drop intot he upper 30s over far northeast Missouri tonight under clear skies. Should be a fine day on Saturday with partly cloudy skies and mild tempatures over the region as surface high pressure builds over the area. Could reach record lows for far northeast Missouri and again on Sunday morning for northeast through central Missouri. Przybylinski && .SHORT TERM: (Through Tonight) Issued at 236 PM CDT Fri Sep 12 2014 Cloud cover continues to cover the area this afternoon as stratus is trapped under a low level inversion and mid-high level clouds are streaming in ahead of a mid level trough. There has been some light rain associated with the mid-level trough moving across northern Missouri early this afternoon, but it`s coverage has been limited. Latest runs of the RAP and HRRR still show some redevelopment of some light rain over western Missouri this afternoon and this evening ahead of the upper trough that will move across the CWA this evening. Then expect clearing of the clouds from north to south after 06Z as the upper trough moves to the east allowing subsidence to set in. Drier air will move into the low levels as the inversion weakens which should allow the low level clouds to move out. Temperatures should fall close to agreeable MOS guidance for lows once skies begin to clear with the light northeasterly winds. Britt .LONG TERM: (Saturday through Next Friday) Issued at 236 PM CDT Fri Sep 12 2014 (Saturday through Monday) Overall, mdls are in good agreement thru this period. Period begins with a large sfc ridge settling across the region. This ridge will keep temps around 15 degrees below seasonal average despite ample insolation. As the ridge retreats, the approaching trof and sfc fnt will bring another chance for precip to the region late in the period. Some minor differences in timing are apparent among the mdl guidance. Will keep PoPs lower except where mdls are in agreement. (Tuesday through Friday) Not much change from the prev forecast. Mdls remain in good agreement overall thru the period with respect to mass fields anyway. Sfc ridge builds into the region on Tues with precip coming to an end Mon night. Cool temps will prevail thru mid week, tho not as cool as this weekend. Mdls differ regarding precip chances for late Wed into Thurs. The ECMWF is more robust with nocturnal convection developing along a stationary fnt across the region. The GFS would suggest height rising with the sfc ridge still holding on into the area. Have kept PoPs low given the uncertainty forecasting mesoscale features on day 7. As for temps, have trended twd the warmer guidance thru the period given heights over the region. Tilly && .AVIATION: (For the 06z TAFs through 06z Saturday Night) Issued at 1119 PM CDT Fri Sep 12 2014 Subsidence and dry air advection at low levels are significantly eroding the MVFR stratus in place across the region. The clearing line has already moved through KUIN and KCOU and should reach St. Louis metro TAF sites during 06-09z. There could be some isolated spots of fog once clearing occurs, but the combination of drying low levels and sustained winds AOA 7kts should act to limit any fog formation to those sheltered areas with higher low-level moisture. Generally VFR conditions are expected thereafter. Kanofsky && .CLIMATE: Issued at 236 PM CDT Fri Sep 12 2014 Record Lows This Weekend: STL COU UIN 13 43(1975) 33(1902) 33(1902) 14 46(1996) 40(1892) 38(1996) && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1135 PM CDT FRI SEP 12 2014 .UPDATE... ISSUED AT 924 PM CDT FRI SEP 12 2014 OPTED TO EXPAND THE FROST ADVISORY FOR JUST A COUPLE OF COUNTIES WHERE TEMPS ARE FORECAST TO DROP TO NEAR 36. MAY ALSO SEE SOME PATCHY FOG OVERNIGHT. IT MAY BE VERY THIN GROUND FOG...AND MAYBE MORE STEAM FOG NEAR THE RIVERS AND LAKES. MAY HAVE TO ADD TO THE FORECAST IF IT BECOMES WIDESPREAD OR DENSE ENOUGH...AND WILL CONTINUE TO MONITOR THROUGH THE NIGHTTIME. FOG HAD ALREADY DEVELOPED AT CLARINDA IOWA AND MILLARD...AND LATEST RAP MODEL SUGGESTS IT COULD EXPAND ESPECIALLY ACROSS WESTERN IOWA WHERE WINDS WILL PROBABLY REMAIN CALM OVERNIGHT. && .SHORT TERM...(TONIGHT THROUGH MONDAY) ISSUED AT 319 PM CDT FRI SEP 12 2014 ...FIRST FROST OF THE SEASON EXPECTED FOR PARTS OF THE AREA... THE MAIN CONCERN CONCERN FOR THE SHORT TERM CONTS TO BE WITH THE COLD WEATHER TONIGHT. WE FEEL THAT MOST LOCATIONS WILL FALL SHORT OF THE RECORDS LOWS...BUT WITH SKIES CLEARING...WINDS DIMINISHING THIS EVENING...AND THE SFC HIGH CROSSING THE CWA OVERNIGHT WE ARE IN FOR THE COLDEST NIGHT YET OF THE EARLY FALL SEASON. GOING FORECAST LOWS WERE IN GOOD SHAPE AND VERY FEW CHANGES WERE MADE THERE...BUT WE DID GO AHEAD AND ISSUE A FROST ADVRY FOR PARTS OF THE AREA THAT WILL LIKELY SEE A COUPLE HOURS OF TEMPERATURES AT OR BELOW ABOUT 36 DEGREES. RETURN FLOW STARTS TO KICK ON ON SAT BUT TEMPERATURES WILL REMAIN BELOW NORMAL DESPITE THE MIXING TO 850 MB. LOWS TEMPERATURES WILL BE A BIT WARMER ON SAT NIGHT AHEAD OF A FRONT THAT WILL START TO WORK INTO THE MID MO RVR VALLEY ON SUN. ALL MODELS ARE IN PRETTY GOOD AGREEMENT ON THE EVOLUTION OF THE SENSIBLE WX ASSOCIATED WITH THE FRONT ON SUN/SUN NIGHT ALLOWING FOR INCREASED CONFIDENCE AND HIGHER POPS. MOISTURE RETURN WILL BE LIMITED BUT ISENTROPIC LIFT WILL INCREASE DURING THE DAY ON SUN LEADING TO INCREASING CLOUDS...AND AS LARGE-SCALE FORCING FOR ASCENT ALSO INCREASES LATE ON SUN AFTN...AS A SHORT-WAVE TROUGH WORKS THRU SD...WE SHOULD SEE AN INCREASE IN SHRA AND MAYBE AN ISO TSRA OR TWO. THIS CHANCE WILL CONT TO INCREASE ON SUN NIGHT AND WE WILL HAVE SOME LIKELY POPS IN THE CNTRL AND SRN CWA. THE FRONT WILL SHIFT SOUTH OF OUR AREA ON MON ALLOW FOR ANOTHER SHOT OF COOLER AIR TO MOV IN FOR MON AND MON NIGHT AND WE HAVE LOWERED HIGHS/LOWS DURING THIS TIME. .LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT 319 PM CDT FRI SEP 12 2014 SENSIBLE WEATHER WILL BE PRETTY QUIET IN THE EXTENDED PERIOD OF THE FORECAST. THE OVER-ALL PATTERN WILL TRANSITION FROM NORTHWEST FLOW AND COOL AT THE START OF THE PERIOD TO WESTERLY AND A BIT WARMER AT THE END. THE PERIOD WILL GENERALLY BE DRY BUT AS THE UPPER LEVEL FLOW TURNS MORE WEST WE WILL SEE AN INCREASE IN MOISTURE THAT MAY LEAD TO SOME CHC FOR PRECIP TOWARDS THE END OF THE PERIOD...ESPECIALLY IN THE NORTHERN CWA CLOSER TO A BOUNDARY. && .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1134 PM CDT FRI SEP 12 2014 VFR CONDITIONS THROUGH THE PERIOD...ALTHOUGH ALL TAF SITES MAY SEE SOME PATCHY MVFR FOG 09-13Z. LIGHT AND VARIABLE WINDS BECOME SOUTH AT 12-16 KNOTS BY 16Z...COULD SEE GUSTS UP TO ABOUT 20-22 KNOTS AT KLNK/KOFK THAT WOULD LINGER THROUGH ABOUT 00Z. THEN WINDS BECOME AT OR BELOW 10 KNOTS BY 00Z AND BEYOND. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...FROST ADVISORY FROM 3 AM TO 9 AM CDT SATURDAY FOR NEZ015>018- 030>034-042>045-050-051-065-066-078-088-089. IA...FROST ADVISORY FROM 3 AM TO 9 AM CDT SATURDAY FOR IAZ043-055-056- 069-079-080-090-091. && $$ UPDATE...DEWALD SHORT TERM...BOUSTEAD LONG TERM...BOUSTEAD AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
503 AM EDT SAT SEP 13 2014 .SYNOPSIS... A FLOOD WATCH HAS BEEN ISSUED FOR SATURDAY AS A STALLED COLD FRONT CONTINUES UNSETTLED WEATHER ACROSS THE AREA. THIS FRONT WILL REMAIN IN THE VICINITY ON SUNDAY...BEFORE LIFTING BACK NORTH ON MONDAY...BUT UNSETTLED WEATHER WILL PERSIST. A STRONGER COLD FRONT WILL CROSS THE AREA ON TUESDAY...BRINGING COOLER AND DRIER WEATHER FOR THE LATTER HALF OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 415 AM SATURDAY...A FLOOD WATCH HAS BEEN POSTED FOR THE ENTIRE ILM CWA...IN EFFECT FROM 6 AM THIS MORNING THROUGH 6 AM SUNDAY MORNING. A STALLED FRONTAL BOUNDARY LYING EAST-WEST NEARLY ALONG THE NC-SC BORDER WILL LIKELY MEANDER BOTH NORTH AND SOUTH THROUGHOUT THE NEAR TERM PERIOD. INITIALLY...IT MAY TEMPORARILY PUSH NORTHWARD DUE TO A VIGOROUS UPPER S/W TROF PUSHING FROM THE GREAT LAKES TO THE NE STATES TODAY. THEN SETTLING BACK TO THE SOUTH TONIGHT...WITH MODELS HINTING THAT IT MAY DROP SOUTH OF THE ILM CWA EARLY SUNDAY. PLENTY OF MOISTURE ON EITHER SIDE OF THE FRONTAL BOUNDARY WITH PWS 2+ INCHES. TO AID PCPN DEVELOPMENT...FORCING... UVVS...WILL BE PROVIDED BY THE SFC FRONT ITSELF...AND UPPER DYNAMICS IN THE FORM OF A S/W TROF OR VORT...WILL PROVIDE THE ADDITIONAL LIFT. NORTH OF THE FRONT WILL OBSERVE OVERRUNNING TYPE PCPN...IE. STRATIFORM RAINS. HOWEVER...ELEVATED CONVECTION REMAINS A GOOD POSSIBILITY NORTH OF THE FRONT DUE TO THE AVAILABILITY OF ELEVATED CAPE...ENERGY. SOUTH OF THE FRONT...THE CHARACTER OF THE PCPN WILL BE MORE CONVECTIVE. THUS...DIRECTLY ON EITHER SIDE OF THE FRONT...THE FA WILL BE SUBJECT TO PCPN THAT WILL MOVE ACROSS ALREADY SATURATED GROUNDS...OVER AND OVER AGAIN...WITH THE END RESULT LIKELY FLOODING. THUS...A 24 HR FLOOD WATCH HAS BEEN ISSUED FOR THE ENTIRE ILM CWA...IN EFFECT FROM 6AM SAT-6AM SUN. VARIOUS MODEL MOS GUIDANCE INDICATES WIDESPREAD 80S FOR MAX TEMPS TODAY. DEPENDING ON WHICH SIDE OF THE FRONT ONE IS...THE RANGE WILL RUN FROM THE LOW 80S NORTHERN PORTIONS OF THE ILM CWA TO MID- UPPER 80S SOUTH OF THE FRONT. THE WIDESPREAD CLOUDS AND PCPN MAY FURTHER PREVENT TEMPS FROM CLIMBING...ESPECIALLY NORTH OF THE FRONT WHERE UPPER 70S IS NOT OUT OF THE QUESTION. THE COOLER AND DRIER AIR BEHIND THE FRONT REMAINS WELL UPSTREAM...FROM VIRGINIA AND NORTHWARD. THUS EVEN IF TEMPORARY FROPA DOES OCCUR...THIS AIRMASS WILL NOT BE ABLE TO INFILTRATE THE REGION DURING THIS NEAR TERM PERIOD. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 300 AM SATURDAY...AN EXPANDING TROUGH AND A PERSISTENT RIDGE WILL ENGAGE IN BATTLE OVERHEAD THROUGH EARLY NEXT WEEK FOR POSITION OVER THE CAROLINAS. ALMOST LIKE THE OLD CHILDHOOD GAME OF "RED ROVER"...EACH FEATURE WILL TRY TO BREAK THROUGH THE OTHER...BUT THE RIDGE WILL CALL THE TROUGH OVER ONE TOO MANY TIMES...EARNING THE TROUGH A VICTORY...DISPLACING THE RIDGE BY MONDAY NIGHT. THIS FORCES THE COLD FRONT BELOW TO BECOME NEARLY STATIONARY SUNDAY AND MONDAY...WAVERING BACK AND FORTH ACROSS THE AREA...CONTINUING THE UNSETTLED WEATHER PATTERN. SURFACE FRONT WILL BE ALONG THE SOUTHERN TIER...OR JUST SOUTH...OF THE CWA DURING SUNDAY BEFORE SLOWLY LIFTING NORTH AGAIN ON MONDAY. WHILE INSTABILITY WILL BE LIMITED DUE TO WIDESPREAD CLOUD COVER...AND UPPER SUPPORT WILL REMAIN MINIMAL...PERSISTENT MOIST FLOW ATOP THE FRONT COMBINED WITH SURFACE CONVERGENCE ALONG IT (AND RESIDUAL BOUNDARIES) IN A VERY MOIST COLUMN WILL PRODUCE PERIODS OF RAIN/TSTMS SUNDAY AND MONDAY. BEST PRECIP CHANCES MAY BE IN THE SOUTHERN AND WESTERN ZONES SUNDAY AND THIS IS WHERE THE HIGHEST QPF IS EXPECTED...BUT ALL AREAS WILL LIKELY SEE SHOWERS AND STORMS. A BRIEF RESPITE IN CONVECTIVE COVERAGE WILL OCCUR WITH LOSS OF HEATING SUNDAY NIGHT...BEFORE MORE SCATTERED CONVECTION DEVELOPS MONDAY AS THE FRONT LIFTS TO THE NORTH PRODUCING A BRIEF PERIOD OF WAA AND SUMMER-LIKE CONVECTION. THIS WILL BE SHORT LIVED HOWEVER...AS THIS FRONT WILL RETURN BACK TO THE SOUTHEAST AS A COLD FRONT BENEATH A STRONG VORTICITY IMPULSE MOVING TO THE NORTH EITHER VERY LATE MONDAY NIGHT...OR JUST BEYOND THIS PERIOD. ANOTHER ROUND OF HEAVIER PRECIP MAY ACCOMPANY THIS FRONT LATE MONDAY HOWEVER...AND CANNOT AT ANY TIME FORECAST POP BELOW CHC THROUGH THE PERIOD...WITH HIGHEST OCCURRING SUNDAY AND THEN AGAIN LATE MONDAY. HIGHS SUNDAY WILL BE SEVERAL DEGREES BELOW NORMAL THANKS TO CLOUDS...RAIN...AND COOL NORTHERLY SURFACE FLOW...WITH MAX TEMPS EXPECTED TO REACH ONLY THE MID 70S FAR NW...TO MID 80S NEAR THE SOUTH SANTEE RIVER. THE AFOREMENTIONED WAA WILL DRIVE HIGHS INTO THE LOW/MID 80S CWA-WIDE ON MONDAY. LOWS SUNDAY NIGHT WILL DROP TO NEAR-NORMAL LEVELS OF THE MID 60S...BUT WILL BE SEVERAL DEGREES WARMER MONDAY NIGHT AHEAD OF THE NEXT COLD FRONT. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 300 SATURDAY...STRONG COLD FRONT WILL PUSH ACROSS THE AREA ON TUESDAY...USHERING IN COOL CANADIAN AIR FOR MOST OF THE UPCOMING WEEK. STRONG VORTICITY IMPULSE SPAWNING A SURFACE LOW PRESSURE WILL BE RACING EAST WELL NORTH OF THE AREA...BUT A STRONG COLD FRONT BEHIND THIS WILL DRAG ACROSS THE CWA DURING TUESDAY. A PERIOD OF UNSETTLED WEATHER IS EXPECTED TUESDAY WITH SHOWERS AND THUNDERSTORMS...BUT THIS FRONT SHOULD PUSH OFFSHORE BY WEDNESDAY AS A DEEP UPPER TROUGH DIVES INTO THE EAST. THEREAFTER...GUIDANCE CONTINUES TO DIFFER ON HOW FAR OFFSHORE THIS FRONT WILL STALL...WITH THE GFS CONTINUING TO INDICATE THAT IT WILL BE JUST OFFSHORE AND CONTINUE UNSETTLED CONDITIONS LOCALLY. THE ECMWF...WHICH IS PREFERRED...PUSHES THIS FRONT WELL OFF THE COAST...WHICH SEEMS ACCURATE BASED OFF THE STRENGTH OF THE UPPER TROUGH AND SINCE WE HAVE HAD SEVERAL FROPAS ALREADY THIS YEAR. USING THE ECMWF AS A GUIDE...WED-FRI WILL FEATURE DRYING CONDITIONS AND TEMPS AROUND 5 DEGREES BELOW CLIMO THANKS TO THE CANADIAN ORIGIN OF THE SURFACE HIGH RIDGING DOWN THE COAST. IN ADDITION...IT APPEARS THE AREA WILL SEE SUNSHINE FOR THE FIRST TIME IN SEVERAL DAYS BY WEDNESDAY. HOWEVER...MUST NOTE THE PERSISTENCE OF THE GFS WHICH KEEPS THE FRONT JUST OFF THE COAST AND DEVELOPS A LOW PRESSURE SYSTEM ALONG THE TAIL END OF THE BOUNDARY. THIS WOULD KEEP UNSETTLED CONDITIONS ACROSS THE AREA...ESPECIALLY NEAR THE COAST...WITH MORE WET WEATHER POSSIBLE LATE IN THE WEEK. WILL KEEP INHERITED LOW-CHC/SCHC POP FOR POTENTIAL...BUT WITH A SLIGHT DECREASE IN SPECIFIC VALUES TO ACCOUNT FOR THE MUCH DRIER ECMWF. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... AS OF 06Z...STRATIFORM LIGHT RAIN NEAR KILM SHOULD DISSIPATE OVER THE NEXT SEVERAL HOURS...ALTHOUGH THE HRRR MODEL SUGGESTS ISOLATED CONVECTIVE SHOWERS WILL RE-DEVELOP EARLY THIS MORNING ACROSS THE AREA. EXPECT THICK MID/UPPER CLOUD COVER THROUGH THE TAF VALID PERIOD WITH COPIOUS AMOUNTS OF LOW LEVEL MOISTURE. IFR/LIFR CONDITIONS WILL DEVELOP THIS MORNING KLBT/KILM/FLO WITH HIGHEST CONFIDENCE AT KLBT/KILM WHICH IS NEAREST A STATIONARY FRONT. KCRE/KMYR ARE MORE LIKELY TO EXPERIENCE MVFR CONDITIONS THIS MORNING. ANY IFR IMPROVES TO MVFR FAIRLY QUICKLY AFTER SUNRISE WITH VFR DEVELOPING MID-LATE MORNING. CLOUD COVER SHOULD INITIALLY INHIBIT HEATING AND LIFT SO THINK WORSE CASE VCSH COASTAL TERMINALS IN THE MORNING HOURS. BY AFTERNOON THUNDERSTORM POTENTIAL SHOULD BE GREATEST AT KLBT. THIS POTENTIAL SHOULD SHIFT SE-E TO KFLO AND THE THE COASTAL TERMINALS IN THE LATE AFTERNOON/EARLY EVENING. EXTENDED OUTLOOK...A CHANCE OF SHOWERS WITH MAINLY AFTERNOON THUNDERSTORMS/TEMPO MVFR THROUGH TUESDAY. && .MARINE... NEAR TERM/THROUGH TONIGHT/... AS OF 415 AM SATURDAY...WINDS AND TO A LESSER DEGREE SIGNIFICANT SEAS...WILL BE GOVERNED BY THE MEANDERING FRONTAL BOUNDARY DURING THIS PERIOD. THIS MEANS...WATERS NORTH OF THE FRONT WILL OBSERVE NE-E WINDS...AND SOUTH OF THE FRONT THE WATERS WILL SEE SE-SSW WINDS. THE SFC PG REMAINS LOOSE FOR THE MOST PART RESULTING WITH WIND SPEEDS AROUND 10 KT. HOWEVER...DEPENDING ON YOUR LOCATION BEHIND THE FRONT...THE NE-E WINDS THAT OCCUR COULD PRODUCE A MINI-SURGE WITH SPEEDS UP TO 15 KT. SIGNIFICANT SEAS WILL REMAIN DOCILE...AROUND 2 FT. THE MINI NE-E SURGE BEHIND THE FRONT COULD PRODUCE SIG. SEAS UP TO 3 FT. AVERAGE PERIODS WILL RUN 4 TO 5 SECONDS. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 300 AM SATURDAY...COLD FRONT SOUTH OF THE WATERS TO START THE PERIOD WILL REMAIN NEARLY STATIONARY SUNDAY...BEFORE LIFTING BACK TO THE NORTH AS A WARM FRONT MONDAY. THIS DRIVES NE WINDS ALL SUNDAY AND INTO MONDAY...BEFORE VEERING TO BECOME S/SE LATE ON MONDAY. SPEEDS WILL BE 5-10 KTS REGARDLESS OF DIRECTION. A COLD FRONT WILL APPROACH AT THE VERY END OF THE SHORT TERM WITH WINDS BEGINNING TO VEER TO THE WEST LATE MONDAY NIGHT. SEAS WILL BE 1-3 FT THROUGH THE PERIOD...WITH A NE WIND WAVE PREDOMINANT ON SUNDAY...BECOMING SOUTHERLY DURING MONDAY. LONG TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 300 AM SATURDAY...THE BEGINNING OF AN EXTENDED PERIOD OF POOR MARINE CONDITIONS EXPECTED TUESDAY AS A COLD FRONT CROSSES THE WATERS. ALTHOUGH WINDS TUESDAY WILL BE PRETTY LIGHT...5-10 KTS WITH SEVERAL VEERING WIND DIRECTIONS...THE CONFUSED SPECTRUM WILL COMBINE WITH THE SLOWLY AMPLIFYING LONG PERIOD 13-14 SEC SE SWELL ASSOCIATED WITH TROPICAL STORM EDOUARD MOVING THROUGH THE CENTRAL ATLANTIC...TO DRIVE INCREASING WAVE HEIGHTS. ADDITIONALLY...A NE SURGE WILL BEGIN TUESDAY NIGHT BEHIND THIS BOUNDARY...WITH NE WINDS RISING TO AROUND 15 KTS ON WEDNESDAY. THE COMBINATION OF THE LONG-PERIOD SWELL AND INCREASING WINDS WILL DRIVE WAVE HEIGHTS FROM 2-4 FT TUESDAY TO 4-6 FT WEDNESDAY...AND A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED BEGINNING WEDNESDAY. ALTHOUGH IT IS BEYOND THIS PERIOD...IT APPEARS WEDNESDAY COULD BE THE FIRST OF SEVERAL CONSECUTIVE DAYS WITH HEADLINES NEEDED ACROSS THE COASTAL WATERS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...FLOOD WATCH THROUGH LATE TONIGHT FOR SCZ017-023-024-032-033- 039-053>056. NC...FLOOD WATCH THROUGH LATE TONIGHT FOR NCZ087-096-099-105>110. MARINE...NONE. && $$ SYNOPSIS...JDW NEAR TERM...DCH SHORT TERM...JDW LONG TERM...JDW AVIATION...DCH/MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
338 AM EDT SAT SEP 13 2014 .SYNOPSIS... A FLOOD WATCH HAS BEEN ISSUED FOR SATURDAY AS A STALLED COLD FRONT CONTINUES UNSETTLED WEATHER ACROSS THE AREA. THIS FRONT WILL REMAIN IN THE VICINITY ON SUNDAY...BEFORE LIFTING BACK NORTH ON MONDAY...BUT UNSETTLED WEATHER WILL PERSIST. A STRONGER COLD FRONT WILL CROSS THE AREA ON TUESDAY...BRINGING COOLER AND DRIER WEATHER FOR THE LATTER HALF OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 10:30 PM FRIDAY...ALTHOUGH MOST OF THE FORECAST AREA THIS EVENING SAW STRATIFORM RAIN OF GRADUALLY DIMINISHING EXTENT...THE CAPE FEAR REGION AND WILMINGTON IN PARTICULAR EXPERIENCED A HEAVY RAIN EVENT COMPLETE WITH LOCALIZED FLOODING. IT APPEARS THAT A SERIES OF UNFORTUNATELY PLACED BOUNDARY COLLISIONS AND A JUICY AIR-MASS WERE RESPONSIBLE. LIGHT TO MODERATE RAIN IS STILL BLANKETING NEW HANOVER COUNTY AND A FLOOD WARNING IS OUT FOR THAT AREA. GIVEN P/W VALUES IN EXCESS OF 2 INCHES SHOWER ACTIVITY AREA- WIDE CONTINUES TO BE A POSSIBILITY...ESPECIALLY GIVEN THE PROXIMITY OF THE COLD FRONT...WHICH SEEMS TO NOW EXTEND ACROSS THE NORTHERN HALF OF THE FORECAST AREA WITH A FRONTAL WAVE NOW PLACED OVER THE CAPE FEAR REGION. THIS ALSO NO DOUBT ENHANCED OUR RECENT BOUT OF HEAVY RAIN. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 300 AM SATURDAY...AN EXPANDING TROUGH AND A PERSISTENT RIDGE WILL ENGAGE IN BATTLE OVERHEAD THROUGH EARLY NEXT WEEK FOR POSITION OVER THE CAROLINAS. ALMOST LIKE THE OLD CHILDHOOD GAME OF "RED ROVER"...EACH FEATURE WILL TRY TO BREAK THROUGH THE OTHER...BUT THE RIDGE WILL CALL THE TROUGH OVER ONE TOO MANY TIMES...EARNING THE TROUGH A VICTORY...DISPLACING THE RIDGE BY MONDAY NIGHT. THIS FORCES THE COLD FRONT BELOW TO BECOME NEARLY STATIONARY SUNDAY AND MONDAY...WAVERING BACK AND FORTH ACROSS THE AREA...CONTINUING THE UNSETTLED WEATHER PATTERN. SURFACE FRONT WILL BE ALONG THE SOUTHERN TIER...OR JUST SOUTH...OF THE CWA DURING SUNDAY BEFORE SLOWLY LIFTING NORTH AGAIN ON MONDAY. WHILE INSTABILITY WILL BE LIMITED DUE TO WIDESPREAD CLOUD COVER...AND UPPER SUPPORT WILL REMAIN MINIMAL...PERSISTENT MOIST FLOW ATOP THE FRONT COMBINED WITH SURFACE CONVERGENCE ALONG IT (AND RESIDUAL BOUNDARIES) IN A VERY MOIST COLUMN WILL PRODUCE PERIODS OF RAIN/TSTMS SUNDAY AND MONDAY. BEST PRECIP CHANCES MAY BE IN THE SOUTHERN AND WESTERN ZONES SUNDAY AND THIS IS WHERE THE HIGHEST QPF IS EXPECTED...BUT ALL AREAS WILL LIKELY SEE SHOWERS AND STORMS. A BRIEF RESPITE IN CONVECTIVE COVERAGE WILL OCCUR WITH LOSS OF HEATING SUNDAY NIGHT...BEFORE MORE SCATTERED CONVECTION DEVELOPS MONDAY AS THE FRONT LIFTS TO THE NORTH PRODUCING A BRIEF PERIOD OF WAA AND SUMMER-LIKE CONVECTION. THIS WILL BE SHORT LIVED HOWEVER...AS THIS FRONT WILL RETURN BACK TO THE SOUTHEAST AS A COLD FRONT BENEATH A STRONG VORTICITY IMPULSE MOVING TO THE NORTH EITHER VERY LATE MONDAY NIGHT...OR JUST BEYOND THIS PERIOD. ANOTHER ROUND OF HEAVIER PRECIP MAY ACCOMPANY THIS FRONT LATE MONDAY HOWEVER...AND CANNOT AT ANY TIME FORECAST POP BELOW CHC THROUGH THE PERIOD...WITH HIGHEST OCCURRING SUNDAY AND THEN AGAIN LATE MONDAY. HIGHS SUNDAY WILL BE SEVERAL DEGREES BELOW NORMAL THANKS TO CLOUDS...RAIN...AND COOL NORTHERLY SURFACE FLOW...WITH MAX TEMPS EXPECTED TO REACH ONLY THE MID 70S FAR NW...TO MID 80S NEAR THE SOUTH SANTEE RIVER. THE AFOREMENTIONED WAA WILL DRIVE HIGHS INTO THE LOW/MID 80S CWA-WIDE ON MONDAY. LOWS SUNDAY NIGHT WILL DROP TO NEAR-NORMAL LEVELS OF THE MID 60S...BUT WILL BE SEVERAL DEGREES WARMER MONDAY NIGHT AHEAD OF THE NEXT COLD FRONT. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 300 SATURDAY...STRONG COLD FRONT WILL PUSH ACROSS THE AREA ON TUESDAY...USHERING IN COOL CANADIAN AIR FOR MOST OF THE UPCOMING WEEK. STRONG VORTICITY IMPULSE SPAWNING A SURFACE LOW PRESSURE WILL BE RACING EAST WELL NORTH OF THE AREA...BUT A STRONG COLD FRONT BEHIND THIS WILL DRAG ACROSS THE CWA DURING TUESDAY. A PERIOD OF UNSETTLED WEATHER IS EXPECTED TUESDAY WITH SHOWERS AND THUNDERSTORMS...BUT THIS FRONT SHOULD PUSH OFFSHORE BY WEDNESDAY AS A DEEP UPPER TROUGH DIVES INTO THE EAST. THEREAFTER...GUIDANCE CONTINUES TO DIFFER ON HOW FAR OFFSHORE THIS FRONT WILL STALL...WITH THE GFS CONTINUING TO INDICATE THAT IT WILL BE JUST OFFSHORE AND CONTINUE UNSETTLED CONDITIONS LOCALLY. THE ECMWF...WHICH IS PREFERRED...PUSHES THIS FRONT WELL OFF THE COAST...WHICH SEEMS ACCURATE BASED OFF THE STRENGTH OF THE UPPER TROUGH AND SINCE WE HAVE HAD SEVERAL FROPAS ALREADY THIS YEAR. USING THE ECMWF AS A GUIDE...WED-FRI WILL FEATURE DRYING CONDITIONS AND TEMPS AROUND 5 DEGREES BELOW CLIMO THANKS TO THE CANADIAN ORIGIN OF THE SURFACE HIGH RIDGING DOWN THE COAST. IN ADDITION...IT APPEARS THE AREA WILL SEE SUNSHINE FOR THE FIRST TIME IN SEVERAL DAYS BY WEDNESDAY. HOWEVER...MUST NOTE THE PERSISTENCE OF THE GFS WHICH KEEPS THE FRONT JUST OFF THE COAST AND DEVELOPS A LOW PRESSURE SYSTEM ALONG THE TAIL END OF THE BOUNDARY. THIS WOULD KEEP UNSETTLED CONDITIONS ACROSS THE AREA...ESPECIALLY NEAR THE COAST...WITH MORE WET WEATHER POSSIBLE LATE IN THE WEEK. WILL KEEP INHERITED LOW-CHC/SCHC POP FOR POTENTIAL...BUT WITH A SLIGHT DECREASE IN SPECIFIC VALUES TO ACCOUNT FOR THE MUCH DRIER ECMWF. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... AS OF 06Z...STRATIFORM LIGHT RAIN NEAR KILM SHOULD DISSIPATE OVER THE NEXT SEVERAL HOURS...ALTHOUGH THE HRRR MODEL SUGGESTS ISOLATED CONVECTIVE SHOWERS WILL RE-DEVELOP EARLY THIS MORNING ACROSS THE AREA. EXPECT THICK MID/UPPER CLOUD COVER THROUGH THE TAF VALID PERIOD WITH COPIOUS AMOUNTS OF LOW LEVEL MOISTURE. IFR/LIFR CONDITIONS WILL DEVELOP THIS MORNING KLBT/KILM/FLO WITH HIGHEST CONFIDENCE AT KLBT/KILM WHICH IS NEAREST A STATIONARY FRONT. KCRE/KMYR ARE MORE LIKELY TO EXPERIENCE MVFR CONDITIONS THIS MORNING. ANY IFR IMPROVES TO MVFR FAIRLY QUICKLY AFTER SUNRISE WITH VFR DEVELOPING MID-LATE MORNING. CLOUD COVER SHOULD INITIALLY INHIBIT HEATING AND LIFT SO THINK WORSE CASE VCSH COASTAL TERMINALS IN THE MORNING HOURS. BY AFTERNOON THUNDERSTORM POTENTIAL SHOULD BE GREATEST AT KLBT. THIS POTENTIAL SHOULD SHIFT SE-E TO KFLO AND THE THE COASTAL TERMINALS IN THE LATE AFTERNOON/EARLY EVENING. EXTENDED OUTLOOK...A CHANCE OF SHOWERS WITH MAINLY AFTERNOON THUNDERSTORMS/TEMPO MVFR THROUGH TUESDAY. && .MARINE... NEAR TERM/THROUGH TONIGHT/... AS OF 10:30 PM FRIDAY...LIGHT AND VARIABLE WINDS WITH 2 FT SEAS CONTINUE ACROSS THE WATERS THIS EVENING. FORECAST REMAINS UNCHANGED. PREVIOUS DISCUSSION FOLLOWS: OUTSIDE OF TSTMS NO REAL PROBLEMS EXPECTED ON THE WATERS WITH LIGHT WINDS OVERALL AND SEAS 2 FEET OR LESS...AS A WEAK FRONTAL BOUNDARY REMAINS IN VICINITY OF THE AREA. MOST STORMS SHOULD STAY OVER LAND BUT TONIGHT CELLS MAY BEGIN TO FAVOR THE 0-20 NM WATERS. SEAS AROUND 2 FEET IN A MIX OF SE WAVES 1-1.5 FT EVERY 8-9 SECONDS AND S WAVES 0.5-1 FT EVERY 3-4 SECONDS. WITHIN TSTMS WINDS AND SEAS WILL BE LOCALLY AND SIGNIFICANTLY HIGHER. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 300 AM SATURDAY...COLD FRONT SOUTH OF THE WATERS TO START THE PERIOD WILL REMAIN NEARLY STATIONARY SUNDAY...BEFORE LIFTING BACK TO THE NORTH AS A WARM FRONT MONDAY. THIS DRIVES NE WINDS ALL SUNDAY AND INTO MONDAY...BEFORE VEERING TO BECOME S/SE LATE ON MONDAY. SPEEDS WILL BE 5-10 KTS REGARDLESS OF DIRECTION. A COLD FRONT WILL APPROACH AT THE VERY END OF THE SHORT TERM WITH WINDS BEGINNING TO VEER TO THE WEST LATE MONDAY NIGHT. SEAS WILL BE 1-3 FT THROUGH THE PERIOD...WITH A NE WIND WAVE PREDOMINANT ON SUNDAY...BECOMING SOUTHERLY DURING MONDAY. LONG TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 300 AM SATURDAY...THE BEGINNING OF AN EXTENDED PERIOD OF POOR MARINE CONDITIONS EXPECTED TUESDAY AS A COLD FRONT CROSSES THE WATERS. ALTHOUGH WINDS TUESDAY WILL BE PRETTY LIGHT...5-10 KTS WITH SEVERAL VEERING WIND DIRECTIONS...THE CONFUSED SPECTRUM WILL COMBINE WITH THE SLOWLY AMPLIFYING LONG PERIOD 13-14 SEC SE SWELL ASSOCIATED WITH TROPICAL STORM EDOUARD MOVING THROUGH THE CENTRAL ATLANTIC...TO DRIVE INCREASING WAVE HEIGHTS. ADDITIONALLY...A NE SURGE WILL BEGIN TUESDAY NIGHT BEHIND THIS BOUNDARY...WITH NE WINDS RISING TO AROUND 15 KTS ON WEDNESDAY. THE COMBINATION OF THE LONG-PERIOD SWELL AND INCREASING WINDS WILL DRIVE WAVE HEIGHTS FROM 2-4 FT TUESDAY TO 4-6 FT WEDNESDAY...AND A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED BEGINNING WEDNESDAY. ALTHOUGH IT IS BEYOND THIS PERIOD...IT APPEARS WEDNESDAY COULD BE THE FIRST OF SEVERAL CONSECUTIVE DAYS WITH HEADLINES NEEDED ACROSS THE COASTAL WATERS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...FLOOD WATCH THROUGH LATE TONIGHT FOR SCZ017-023-024-032-033- 039-053>056. NC...FLOOD WATCH THROUGH LATE TONIGHT FOR NCZ087-096-099-105>110. MARINE...NONE. && $$ SYNOPSIS...JDW NEAR TERM...DCH/REK SHORT TERM...JDW LONG TERM...JDW AVIATION...DCH/MRR MARINE...DCH/REK/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
157 AM EDT SAT SEP 13 2014 .SYNOPSIS... A COLD FRONT WILL BRING UNSETTLED WEATHER THROUGH THE WEEKEND. THE FRONT WILL WEAKEN ON MONDAY BUT MOISTURE WILL LINGER FOR A SCATTERING OF SHOWERS ON MONDAY. ANOTHER COLD FRONT SHOULD AFFECT THE REGION ON WEDNESDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 10:30 PM FRIDAY...ALTHOUGH MOST OF THE FORECAST AREA THIS EVENING SAW STRATIFORM RAIN OF GRADUALLY DIMINISHING EXTENT...THE CAPE FEAR REGION AND WILMINGTON IN PARTICULAR EXPERIENCED A HEAVY RAIN EVENT COMPLETE WITH LOCALIZED FLOODING. IT APPEARS THAT A SERIES OF UNFORTUNATELY PLACED BOUNDARY COLLISIONS AND A JUICY AIR-MASS WERE RESPONSIBLE. LIGHT TO MODERATE RAIN IS STILL BLANKETING NEW HANOVER COUNTY AND A FLOOD WARNING IS OUT FOR THAT AREA. GIVEN P/W VALUES IN EXCESS OF 2 INCHES SHOWER ACTIVITY AREA- WIDE CONTINUES TO BE A POSSIBILITY...ESPECIALLY GIVEN THE PROXIMITY OF THE COLD FRONT...WHICH SEEMS TO NOW EXTEND ACROSS THE NORTHERN HALF OF THE FORECAST AREA WITH A FRONTAL WAVE NOW PLACED OVER THE CAPE FEAR REGION. THIS ALSO NO DOUBT ENHANCED OUR RECENT BOUT OF HEAVY RAIN. && .SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...ANOTHER FAIRLY UNSETTLED AFTERNOON IN STORE FOR THE REGION SATURDAY AS COLD FRONT ENTERS THE COASTAL PLAIN IN THE PRESENCE OF FAIRLY DEEP TROPICAL MOISTURE. THE MOST WIDESPREAD COVERAGE WILL BE OVER NWRN ZONES WHICH WILL BE MOST PROXIMAL TO THE BOUNDARY...PERHAPS RADAR COVERAGE NOT UNLIKE THAT OF THIS AFTERNOON. WITH A MORE CLOUDY START COMPARED TO TODAY AFTERNOON TEMPERATURES WILL NOT GROW AS HOT AND TEND TO BE QUITE SEASONABLE. PRECIPITABLE WATER REMAINS ABOVE 2 INCHES WHILE STORM MOTION REMAINS BELOW 5KT SO CHANCE FOR HEAVY DOWNPOURS REMAINS INTACT. RAIN CHANCES WILL HAVE A HARD TIME DIPPING MUCH LOWER THAN LOW END CHANCE RANGE SATURDAY NIGHT AS THE FRONT MOVES ATOP OF THE FORECAST AREA...ALTHOUGH THE LOSS OF DAYTIME HEATING SHOULD DIMINISH THEIR INTENSITY AND THE HEAVY RAIN THREAT. WE WIND UP ON THE OTHER SIDE OF THE FRONT ON SUNDAY AS IT REMAINS NEARLY STALLED TO OUR SOUTH AND EAST. RAIN CHANCES WILL BE SHIFTED SOUTH AND EAST ACCORDINGLY AND THE HEAVY RAIN THREAT WILL BE RELATIVELY MITIGATED. SUNDAY AFTERNOON MAY OFFER UP A RANGE OF HIGH TEMPERATURES FROM NORTH TO SOUTH FROM THE UPPER 70S TO THE MID 80S. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 3 PM FRIDAY...WEAKENING FRONT STALLED IN THE AREA AT THE START OF THE PERIOD AND DEEP TROPICAL MOISTURE ENSURE THE FIRST HALF OF NEXT WEEK REMAIN UNSETTLED. PRECIPITABLE WATER VALUES AROUND 2 INCHES MON AND TUE IN A MODERATELY UNSTABLE AIRMASS SHOULD LEAD TO SHOWER AND THUNDERSTORM DEVELOPMENT. PLAN TO CARRY CHC POP WITH A DIURNAL DISTRIBUTION. THE LACK OF FORCING ALOFT SHOULD LEAD TO A DECREASE IN COVERAGE/ACTIVITY OVERNIGHT BUT DO NOT THINK STORMS WILL COMPLETELY DISSIPATE. STORM MOTIONS WILL REMAIN 10 KT OR LESS WHICH WILL MAINTAIN FLOODING POTENTIAL. A STRONGER COLD FRONT WILL DROP IN FROM THE NORTHWEST MID WEEK. THIS FRONT HAS A MORE DEFINED TROUGH BEHIND IT WHICH WILL PUSH THE BOUNDARY SOUTH OF THE AREA BY THE END OF THE WEEK. HOWEVER THERE IS STILL SOME UNCERTAINTY AS TO HOW FAR SOUTH THIS FRONT MOVES BEFORE STALLING. ECMWF HAS THE FRONT FARTHER SOUTH...SO DOES WPC...WHILE THE GFS KEEPS THE FRONT CLOSER TO THE CAROLINAS. BOTH MEDIUM RANGE SOLUTIONS DEVELOP A WEAK LOW ON THE FRONT AND LIFT IT NORTH...THOUGH TIMING IS DIFFERENT. ECMWF SOLUTION WOULD PRODUCE SLIGHT CHC TO LOW CHC OF PRECIP THROUGH THU...MAINLY ALONG THE COAST...WITH DRYING FRI. GFS IS WETTER WITH HIGH CHC TO LIKELY POP THROUGH THE END OF THE PERIOD FOR MUCH OF THE FORECAST AREA. PREVIOUS FORECASTS HAVE BEEN IN LINE WITH THE DRIER ECMWF/WPC SOLUTION AND AT THIS POINT CAN SEE NO REASON TO MAKE A CHANGE. CONFIDENCE REMAINS LOW SO SIGNIFICANT CHANGES IN LATER FORECASTS IS STILL A POSSIBILITY. TEMPERATURE RANGES EARLY IN THE PERIOD WILL BE ON THE NARROW END WITH CLOUD COVER AND PRECIP KEEPING HIGHS NEAR TO SLIGHTLY BELOW CLIMO BUT HELPING HOLD LOWS SEVERAL DEGREES ABOVE CLIMO. PASSAGE OF FRONT MID WEEK WILL BRING BELOW CLIMO TEMPS FOR THE END OF THE WEEK. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... AS OF 06Z...STRATIFORM LIGHT RAIN NEAR KILM SHOULD DISSIPATE OVER THE NEXT SEVERAL HOURS...ALTHOUGH THE HRRR MODEL SUGGESTS ISOLATED CONVECTIVE SHOWERS WILL RE-DEVELOP EARLY THIS MORNING ACROSS THE AREA. EXPECT THICK MID/UPPER CLOUD COVER THROUGH THE TAF VALID PERIOD WITH COPIOUS AMOUNTS OF LOW LEVEL MOISTURE. IFR/LIFR CONDITIONS WILL DEVELOP THIS MORNING KLBT/KILM/FLO WITH HIGHEST CONFIDENCE AT KLBT/KILM WHICH IS NEAREST A STATIONARY FRONT. KCRE/KMYR ARE MORE LIKELY TO EXPERIENCE MVFR CONDITIONS THIS MORNING. ANY IFR IMPROVES TO MVFR FAIRLY QUICKLY AFTER SUNRISE WITH VFR DEVELOPING MID-LATE MORNING. CLOUD COVER SHOULD INITIALLY INHIBIT HEATING AND LIFT SO THINK WORSE CASE VCSH COASTAL TERMINALS IN THE MORNING HOURS. BY AFTERNOON THUNDERSTORM POTENTIAL SHOULD BE GREATEST AT KLBT. THIS POTENTIAL SHOULD SHIFT SE-E TO KFLO AND THE THE COASTAL TERMINALS IN THE LATE AFTERNOON/EARLY EVENING. EXTENDED OUTLOOK...A CHANCE OF SHOWERS WITH MAINLY AFTERNOON THUNDERSTORMS/TEMPO MVFR THROUGH TUESDAY. && .MARINE... NEAR TERM/THROUGH TONIGHT/... AS OF 10:30 PM FRIDAY...LIGHT AND VARIABLE WINDS WITH 2 FT SEAS CONTINUE ACROSS THE WATERS THIS EVENING. FORECAST REMAINS UNCHANGED. PREVIOUS DISCUSSION FOLLOWS: OUTSIDE OF TSTMS NO REAL PROBLEMS EXPECTED ON THE WATERS WITH LIGHT WINDS OVERALL AND SEAS 2 FEET OR LESS...AS A WEAK FRONTAL BOUNDARY REMAINS IN VICINITY OF THE AREA. MOST STORMS SHOULD STAY OVER LAND BUT TONIGHT CELLS MAY BEGIN TO FAVOR THE 0-20 NM WATERS. SEAS AROUND 2 FEET IN A MIX OF SE WAVES 1-1.5 FT EVERY 8-9 SECONDS AND S WAVES 0.5-1 FT EVERY 3-4 SECONDS. WITHIN TSTMS WINDS AND SEAS WILL BE LOCALLY AND SIGNIFICANTLY HIGHER. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...PREFRONTAL SOUTHWESTERLY FLOW ON SATURDAY SHOULD REMAIN AT 10 KT PREVENTING SEAS FROM ATTAINING HEIGHTS MORE THAN 2 FT. LATE SATURDAY NIGHT AS THE FRONT DRAWS NEAR THE COAST THERE MAY BE A GENTLE BACKING OF THE FLOW FOLLOWED BY A MORE PRECIPITOUS VEER ON SUNDAY ASSOCIATED WITH ACTUAL FROPA. THE FRONT WILL NOT MOVE VERY FAR TO OUR SOUTH BEFORE STALLING WHICH PRECLUDES MUCH OF A SURGE OF HIGH PRESSURE AND THUS ANY HIGHER WINDS. THUS THE VEER TO ENE FLOW APPEARS TO BE THE MAIN EFFECT OF THE FROPA AS WIND SPEEDS AND WAVE HEIGHTS REMAIN UNCHANGED...ALTHOUGH WAVE PERIODS MAY SHORTEN UP A BIT. LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 3 PM FRIDAY...DIMINISHING NORTHERLY SURGE AT THE START OF THE PERIOD WILL LEAVE LIGHT AND VARIABLE WINDS OVER THE WATERS FOR MUCH OF MON AND TUE GIVEN PROXIMITY TO THE STALLED FRONT. ANOTHER COLD FRONT WILL DROP IN FROM THE NORTHWEST DURING THE SECOND HALF OF THE PERIOD. THIS FRONT IS MORE DEFINED AND SHOULD BE ACCOMPANIED BY A STRONGER NORTHERLY SURGE LATER WED INTO WED NIGHT. WINDS WILL APPROACH A SOLID 15 KT WED NIGHT WITH GUSTS AROUND 20 KT POSSIBLE. SEAS 2 TO 3 FT FOR MUCH OF THE PERIOD WILL BUILD AS HIGH AS 5 FT AS THE PERIOD ENDS DUE TO THE PROLONGED AND STEADILY INCREASING NATURE OF THE NORTHERLY SURGE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...COASTAL FLOOD ADVISORY UNTIL 3 AM EDT EARLY THIS MORNING FOR NCZ107. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...MJC/REK SHORT TERM...MBB LONG TERM...III AVIATION...DCH/MRR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
339 AM CDT SAT SEP 13 2014 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 338 AM CDT SAT SEP 13 2014 NO CHANGE IN THE CURRENT FROST ADVISORY...ALTHOUGH A FEW LOCATIONS OVER THE FAR EASTERN CWFA ARE IN THE MID 20S AT 08Z. WITH CIRRUS INCREASING AND RETURN FLOW DEVELOPING DO NOT EXPECT TEMPERATURES TO FALL MORE THAN 1 OR 2 DEGREES IN THE KVWU...KBJI...KBDO AND KADC AREAS. TODAY WILL BE A TRANSITION DAY. AS THE UNSEASONALLY COLD HIGH MOVES SOUTH...LOW PRESSURE INTENSIFIES OVER SASKATCHEWAN SOUTH WINDS WILL INCREASE BY MID DAY. THE MODELS INITIALIZED WELL AND WILL FOLLOW THE HIGHER RESOLUTION HRRR AND NAM12 TODAY...BLENDING THE NAM/GFS FOR TONIGHT INTO SUNDAY MORNING. TIMING OF WARM ADVECTION PRECIPITATION AHEAD OF WELL DEFINED UPPER WAVE OVER FAR NORTH-CENTRAL MONTANA SIMILAR TO PREVIOUS FORECAST REACHING THE DEVILS LAKE BASIN AROUND 18Z AND SPREADING EAST. NAM/GFS HAVE SMALL AREA OF 0C SHOWALTERS AND SOME ML CAPE BUT WILL NOT MENTION TSRA ATTM. WITH WELL MIXED LAYER TO AROUND 800 MB...35 KTS AT 850 IN THE NAM AND NEAR 30 KTS IN THE GFS TRANSLATE TO GUSTS CLOSE TO 30 KTS POSSIBLE. MOS HAS 27 KTS AND WILL FOLLOW THAT FOR THE 18Z - 00Z PERIOD. SECOND STRONGER SHORTWAVE...DROPPING ALONG THE ALBERTA/SASKATCHEWAN BORDER IS FORECAST TO BE NEAR KDVL AT 06Z TONIGHT. SURFACE LOW SLOWS AND WRAP AROUND SHRA SPREADING OVER THE EAST HALF OF THE CWFA INTO SUNDAY MORNING. THE COLUMN COOLS AND DRIES MOST AREAS SUNDAY...WITH LINGERING SHRA OVER THE NORTHEAST PORTION OF THE CWFA...WITH STRONGER MID-UPPER CAA ALONG SHEAR AXIS AND ENTRANCE REGION OF UPPER JET. THIS QUICKLY MOVES OUT WITH PRECIPITATION ENDING BY 00Z MONDAY. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 338 AM CDT SAT SEP 13 2014 WINDS DIMINISH AND SKIES CLEAR AS HIGH PRESSURE MOVES ACROSS THE CWFA. LOWS WILL FALL BACK INTO THE LOW TO MID 30S...BUT EXPECT SUFFICIENT MIXING AT THIS TIME TO KEEP FROST/FREEZE RISK MINIMAL FOR MONDAY MORNING. LIGHT SOUTHWEST WINDS AND PLENTIFUL SUNSHINE WILL ALLOW MODEST WARM-UP MONDAY TO NEAR MID SEPTEMBER NORMALS. RISING HEIGHTS AND CONTINUED WESTERLY FLOW WILL MAKE FOR A MAINLY CLEAR AND MILD MONDAY NIGHT. TUESDAY TO FRIDAY...CONFLUENT NW FLOW ALOFT FOR MUCH OF THE WEEK WITH A QUICK TRANSITIONING PERIOD THURSDAY INTO FRIDAY. AS A RESULT DRY CONDITIONS EXPECTED WITH MODERATING TEMPS AS THICKNESSES INCREASE WITH RIDGING OVER THE FA BY THURSDAY. BY THURSDAY PM OR FRIDAY DEPENDING ON MODEL OF CHOICE...500MB SW FLOW AND 850MB LLJ BRING INSTABILITY INTO FA FROM WEST TO EAST. WENT WITH A MOSTLY SHRA AND ISO THUNDER FOR WX GRIDS AS SHOWALTERS DO BECOME NEGATIVE AHEAD OF THE SFC TROUGH EXPECTED TO IMPACT THE NORTHERN PLAINS TOWARDS THE END OF THE WEEK. TEMPERATURES ABOVE NORMAL THROUGH THE WEEK CAN BE EXPECTED WITH SOME HUMIDITY POSSIBLE BY WEEKS END. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1151 PM CDT FRI SEP 12 2014 A MOSTLY CLEAR SKY WAS ACROSS THE FORECAST AREA. SOME CIRRUS WAS SPILLING INTO THE NORTHWEST ZONES AND WILL SPREAD ACROSS THE AREA OVERNIGHT. FOG LOOP INDICATED PATCHY CLOUDS AROUND 6 THOUSAND FT OVER THE FAR EASTERN ZONES. ONLY BJI HAS COME IN WITH SOME RESTRICTION TO VISIBILITY DUE TO FOG. WILL ADD SOME FOG TO BJI TAF. EXPECT VFR CIGS LATE SAT AFTERNOON/EVENING FROM THE WEST AS NEXT SYSTEM APPROACHES. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...FROST ADVISORY UNTIL 8 AM CDT THIS MORNING FOR NDZ030-039-049- 052-053. MN...FROST ADVISORY UNTIL 8 AM CDT THIS MORNING FOR MNZ001>003-005- 006-008-009-013>017-022>024-027>032-040. && $$ SHORT TERM...EWENS LONG TERM...JK AVIATION...HOPPES
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
335 AM EDT SAT SEP 13 2014 .SYNOPSIS... A SERIES OF SHORT WAVES WILL CARVE OUT PERSISTENT AND STRONG MID- TROPOSPHERIC TROUGH OVER THE EASTERN UNITED STATES. THE FIRST WAVE WILL PRODUCE SOME SHOWERS SATURDAY. SUBSEQUENT WAVES SHOULD KEEP DEEP MOISTURE WELL TO OUR SOUTH...SO IT WILL BE RELATIVELY DRY. SOME UNSEASONABLY COOL WEATHER IS LIKELY NEAR MID-WEEK BEFORE THE PATTERN BEGINS TO WEAKEN BY THE END OF THE COMING WEEK. && .NEAR TERM /UNTIL 9 AM THIS MORNING/... CLOUDS WILL SLOWLY INCREASE WEST TO EAST OVERNIGHT THEN RAPIDLY IN THE MORNING. A FAST MOVING SHORT-WAVE OVER MICHIGAN WILL BRING A CHANCE OF SHOWERS INTO WESTERN AREAS BEFORE 6 AM. AND SLOWLY SPREAD INTO THE WESTERN AREAS OF OUR COUNTY WARNING AREA. THE HIGHER RESOLUTION MODELS AND SREF FAVOR THE CHANCE OF RAINFALL MAINLY AFTER 7 AM. && .SHORT TERM /9 AM THIS MORNING THROUGH 6 PM SUNDAY/... THE FAST MOVING AND STRONG SHORT-WAVE SHOULD BRING RAIN AND SHOWERS TO CENTRAL AND WESTERN AREAS IN THE MORNING AND INTO MIDDAY BEFORE THE HIGHER PROBABILITIES SHIFT TO THE EAST. EASTERN AREAS SHOULD SEE THE RAIN BY LATE MORNING AND INTO THE AFTERNOON HOURS. THE SREF IMPLIES LITTLE OR NO RAIN AFTER ABOUT MIDDAY IN CENTRAL AND WESTERN AREAS AND BY ABOUT 3 PM IN THE EAST. POPS CRASH AFTER 18Z IN THE EAST. THE RAIN WILL RAPIDLY END WEST TO EAST AND THERE COULD BE PEAKS OF SUN IN THE WEST AND CENTRAL AREAS IN THE AFTERNOON. THIS FAST MOVING SYSTEM AND ITS REINFORCING COLD AIR WILL BE TO OUR EAST BY LATER AFTERNOON OR EARLY EVENING. MOST AREAS WILL SEE A 2-4 HOUR PERIOD OF RAINFALL. RAINFALL AMOUNTS SHOULD BE IN THE 0.10 TO 0.30 INCH RANGE IN MOST AREAS. THE RAP FAVORS HIGHER AMOUNTS IN NORTH CENTRAL AND THE SREF IS A SPLIT DECISION WITH SOME HIGHER AMOUNTS IN IN THE SOUTH AND FARTHER NORTH. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... BIG...1027MB HIGH PRESSURE SHOVES IN FROM THE WEST ON SATURDAY NIGHT. THIS STARTS WHAT SHOULD BE AN ALMOST UNBROKEN STRING OF COOL AND DRY WEATHER FOR THE ENTIRE LONG TERM PERIOD AND INTO DAYS 8-PLUS. THE ONLY INKLING OF PRECIP WILL BE ON MON NIGHT AND TUES MORNING. A WEAK FRONT MOVING DOWN FROM THE NW WILL TAP ONLY MEAGER MOISTURES SINCE IT WILL LIE IN BETWEEN THE EARLY- WEEK HIGH PRESSURE AND A SECOND EQUALLY DRY ANTICYCLONE MOVING IN FROM THE UPPER GREAT LAKES AND MIDWEST. AT THE SAME TIME...THERE IS A WAVE PROGGED TO BE SLIDING UP FROM THE GULF COAST STATES. HOWEVER...ALL THE MODELS TAKE IT TO OUR SOUTH...GENERALLY THROUGH THE MID- ATLANTIC STATES EARLY TUESDAY. THIS WOULD CREATE SOME RAIN/SHOWERS ON MONDAY NIGHT AND EARLY TUESDAY. THERE MIGHT BE A BACKDOOR COLD FRONT TRY TO MOVE DOWN AROUND THURSDAY...BUT NO MOISTURE IS TO BE FOUND IN ITS VICINITY. ONE POINT OF INTEREST WILL BE THE LOW TEMPERATURES SUNDAY MORNING AND MONDAY MORNING. THE NORTHERN TIER...ESPECIALLY THE ICE BOX OF KBFD...COULD GET INTO THE MID 30S BOTH MORNINGS - AND PERHAPS EVEN THE LOWER 30S ON MONDAY MORNING. WHAT MIGHT BE MORE REMARKABLE IS A POTENTIAL 30 TO 40F DIURNAL SWING ON MONDAY AS WINDS TURN TO THE S/SW FOR THE DAYTIME BEFORE THE FRONT ARRIVES AT NIGHT/EARLY TUES. BUT EVEN WITH THE GIANT SWING MONDAY SHOULD END UP JUST SLIGHTLY BELOW NORMAL FOR MAXES. WELCOME AUTUMN. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... TIMING ON THE INCOMING RAIN IS THE BIG AVIATION CONCERN OVER THE NEXT 12 HOURS. A SMALL BAND IS CURRENTLY MOVING ACROSS THE SOUTHWESTERN TAF SITES...WHERE JST AND AOO HAVE MVFR CEILINGS. BFD HAS GONE DOWN TO IFR AND SHOULD CONTINUE THROUGH THE MORNING. THE SHOWERS WILL SPREAD ACROSS THE AREA BETWEEN ABOUT 09-15Z SATURDAY MORNING ALONG WITH MVFR/IFR CONDITIONS DEVELOPING. THESE CONDITIONS SHOULD CONTINUE UNTIL AROUND 18Z...BEFORE LIFTING AS THE SYSTEM QUICKLY PASSES. WITH IMPROVING CONDITIONS SATURDAY AFTERNOON. OUTLOOK... SUN...PATCHY AM FOG...OTHERWISE VFR. MON...NO SIG WX. MON NIGHT - TUE...A COLD FRONT WILL BRING REDUCED CONDITIONS WITH SHOWERS. WED...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...GRUMM NEAR TERM...GRUMM SHORT TERM...GRUMM/LA CORTE LONG TERM...DANGELO AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
331 AM EDT SAT SEP 13 2014 .SYNOPSIS... AN AREA OF LOW PRESSURE AT THE SURFACE AND DISTURBANCE ALOFT WILL MOVE QUICKLY EAST ACROSS THE AREA SATURDAY. HIGH PRESSURE AND FAIR WEATHER WILL RETURN ON SUNDAY. THE OVERALL PATTERN FAVORS BELOW NORMAL TEMPERATURES FOR THE NEXT WEEK. && .NEAR TERM /UNTIL 9 AM THIS MORNING/... CLOUDS WILL SLOWLY INCREASE WEST TO EAST OVERNIGHT THEN RAPIDLY IN THE MORNING. A FAST MOVING SHORT-WAVE OVER MICHIGAN WILL BRING A CHANCE OF SHOWERS INTO WESTERN AREAS BEFORE 6 AM. AND SLOWLY SPREAD INTO THE WESTERN AREAS OF OUR COUNTY WARNING AREA. THE HIGHER RESOLUTION MODELS AND SREF FAVOR THE CHANCE OF RAINFALL MAINLY AFTER 7 AM. && .SHORT TERM /9 AM THIS MORNING THROUGH 6 PM SUNDAY/... THE FAST MOVING AND STRONG SHORT-WAVE SHOULD BRING RAIN AND SHOWERS TO CENTRAL AND WESTERN AREAS IN THE MORNING AND INTO MIDDAY BEFORE THE HIGHER PROBABILITIES SHIFT TO THE EAST. EASTERN AREAS SHOULD SEE THE RAIN BY LATE MORNING AND INTO THE AFTERNOON HOURS. THE SREF IMPLIES LITTLE OR NO RAIN AFTER ABOUT MIDDAY IN CENTRAL AND WESTERN AREAS AND BY ABOUT 3 PM IN THE EAST. POPS CRASH AFTER 18Z IN THE EAST. THE RAIN WILL RAPIDLY END WEST TO EAST AND THERE COULD BE PEAKS OF SUN IN THE WEST AND CENTRAL AREAS IN THE AFTERNOON. THIS FAST MOVING SYSTEM AND ITS REINFORCING COLD AIR WILL BE TO OUR EAST BY LATER AFTERNOON OR EARLY EVENING. MOST AREAS WILL SEE A 2-4 HOUR PERIOD OF RAINFALL. RAINFALL AMOUNTS SHOULD BE IN THE 0.10 TO 0.30 INCH RANGE IN MOST AREAS. THE RAP FAVORS HIGHER AMOUNTS IN NORTH CENTRAL AND THE SREF IS A SPLIT DECISION WITH SOME HIGHER AMOUNTS IN IN THE SOUTH AND FARTHER NORTH. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... BIG...1027MB HIGH PRESSURE SHOVES IN FROM THE WEST ON SATURDAY NIGHT. THIS STARTS WHAT SHOULD BE AN ALMOST UNBROKEN STRING OF COOL AND DRY WEATHER FOR THE ENTIRE LONG TERM PERIOD AND INTO DAYS 8-PLUS. THE ONLY INKLING OF PRECIP WILL BE ON MON NIGHT AND TUES MORNING. A WEAK FRONT MOVING DOWN FROM THE NW WILL TAP ONLY MEAGER MOISTURES SINCE IT WILL LIE IN BETWEEN THE EARLY- WEEK HIGH PRESSURE AND A SECOND EQUALLY DRY ANTICYCLONE MOVING IN FROM THE UPPER GREAT LAKES AND MIDWEST. AT THE SAME TIME...THERE IS A WAVE PROGGED TO BE SLIDING UP FROM THE GULF COAST STATES. HOWEVER...ALL THE MODELS TAKE IT TO OUR SOUTH...GENERALLY THROUGH THE MID- ATLANTIC STATES EARLY TUESDAY. THIS WOULD CREATE SOME RAIN/SHOWERS ON MONDAY NIGHT AND EARLY TUESDAY. THERE MIGHT BE A BACKDOOR COLD FRONT TRY TO MOVE DOWN AROUND THURSDAY...BUT NO MOISTURE IS TO BE FOUND IN ITS VICINITY. ONE POINT OF INTEREST WILL BE THE LOW TEMPERATURES SUNDAY MORNING AND MONDAY MORNING. THE NORTHERN TIER...ESPECIALLY THE ICE BOX OF KBFD...COULD GET INTO THE MID 30S BOTH MORNINGS - AND PERHAPS EVEN THE LOWER 30S ON MONDAY MORNING. WHAT MIGHT BE MORE REMARKABLE IS A POTENTIAL 30 TO 40F DIURNAL SWING ON MONDAY AS WINDS TURN TO THE S/SW FOR THE DAYTIME BEFORE THE FRONT ARRIVES AT NIGHT/EARLY TUES. BUT EVEN WITH THE GIANT SWING MONDAY SHOULD END UP JUST SLIGHTLY BELOW NORMAL FOR MAXES. WELCOME AUTUMN. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... TIMING ON THE INCOMING RAIN IS THE BIG AVIATION CONCERN OVER THE NEXT 12 HOURS. A SMALL BAND IS CURRENTLY MOVING ACROSS THE SOUTHWESTERN TAF SITES...WHERE JST AND AOO HAVE MVFR CEILINGS. BFD HAS GONE DOWN TO IFR AND SHOULD CONTINUE THROUGH THE MORNING. THE SHOWERS WILL SPREAD ACROSS THE AREA BETWEEN ABOUT 09-15Z SATURDAY MORNING ALONG WITH MVFR/IFR CONDITIONS DEVELOPING. THESE CONDITIONS SHOULD CONTINUE UNTIL AROUND 18Z...BEFORE LIFTING AS THE SYSTEM QUICKLY PASSES. WITH IMPROVING CONDITIONS SATURDAY AFTERNOON. OUTLOOK... SUN...PATCHY AM FOG...OTHERWISE VFR. MON...NO SIG WX. MON NIGHT - TUE...A COLD FRONT WILL BRING REDUCED CONDITIONS WITH SHOWERS. WED...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/LAMBERT NEAR TERM...GRUMM SHORT TERM...GRUMM/LA CORTE LONG TERM...DANGELO AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
146 AM EDT SAT SEP 13 2014 .SYNOPSIS... AN AREA OF LOW PRESSURE AT THE SURFACE AND DISTURBANCE ALOFT WILL MOVE QUICKLY EAST ACROSS THE AREA SATURDAY. HIGH PRESSURE AND FAIR WEATHER WILL RETURN ON SUNDAY. THE OVERALL PATTERN FAVORS BELOW NORMAL TEMPERATURES FOR THE NEXT WEEK. && .NEAR TERM /UNTIL 9 AM THIS MORNING/... CLOUDS WILL SLOWLY INCREASE WEST TO EAST OVERNIGHT THEN RAPIDLY IN THE MORNING. A FAST MOVING SHORT-WAVE OVER MICHIGAN WILL BRING A CHANCE OF SHOWERS INTO WESTERN AREAS BEFORE 6 AM. AND SLOWLY SPREAD INTO THE WESTERN AREAS OF OUR COUNTY WARNING AREA. THE HIGHER RESOLUTION MODELS AND SREF FAVOR THE CHANCE OF RAINFALL MAINLY AFTER 7 AM. && .SHORT TERM /9 AM THIS MORNING THROUGH 6 PM SUNDAY/... THE FAST MOVING AND STRONG SHORT-WAVE SHOULD BRING RAIN AND SHOWERS TO CENTRAL AND WESTERN AREAS IN THE MORNING AND INTO MIDDAY BEFORE THE HIGHER PROBABILITIES SHIFT TO THE EAST. EASTERN AREAS SHOULD SEE THE RAIN BY LATE MORNING AND INTO THE AFTERNOON HOURS. THE SREF IMPLIES LITTLE OR NO RAIN AFTER ABOUT MIDDAY IN CENTRAL AND WESTERN AREAS AND BY ABOUT 3 PM IN THE EAST. POPS CRASH AFTER 18Z IN THE EAST. THE RAIN WILL RAPIDLY END WEST TO EAST AND THERE COULD BE PEAKS OF SUN IN THE WEST AND CENTRAL AREAS IN THE AFTERNOON. THIS FAST MOVING SYSTEM AND ITS REINFORCING COLD AIR WILL BE TO OUR EAST BY LATER AFTERNOON OR EARLY EVENING. MOST AREAS WILL SEE A 2-4 HOUR PERIOD OF RAINFALL. RAINFALL AMOUNTS SHOULD BE IN THE 0.10 TO 0.30 INCH RANGE IN MOST AREAS. THE RAP FAVORS HIGHER AMOUNTS IN NORTH CENTRAL AND THE SREF IS A SPLIT DECISION WITH SOME HIGHER AMOUNTS IN IN THE SOUTH AND FARTHER NORTH. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... BIG...1027MB HIGH PRESSURE SHOVES IN FROM THE WEST ON SATURDAY NIGHT. THIS STARTS WHAT SHOULD BE AN ALMOST UNBROKEN STRING OF COOL AND DRY WEATHER FOR THE ENTIRE LONG TERM PERIOD AND INTO DAYS 8-PLUS. THE ONLY INKLING OF PRECIP WILL BE ON MON NIGHT AND TUES MORNING. A WEAK FRONT MOVING DOWN FROM THE NW WILL TAP ONLY MEAGER MOISTURES SINCE IT WILL LIE IN BETWEEN THE EARLY- WEEK HIGH PRESSURE AND A SECOND EQUALLY DRY ANTICYCLONE MOVING IN FROM THE UPPER GREAT LAKES AND MIDWEST. AT THE SAME TIME...THERE IS A WAVE PROGGED TO BE SLIDING UP FROM THE GULF COAST STATES. HOWEVER...ALL THE MODELS TAKE IT TO OUR SOUTH...GENERALLY THROUGH THE MID- ATLANTIC STATES EARLY TUESDAY. THIS WOULD CREATE SOME RAIN/SHOWERS ON MONDAY NIGHT AND EARLY TUESDAY. THERE MIGHT BE A BACKDOOR COLD FRONT TRY TO MOVE DOWN AROUND THURSDAY...BUT NO MOISTURE IS TO BE FOUND IN ITS VICINITY. ONE POINT OF INTEREST WILL BE THE LOW TEMPERATURES SUNDAY MORNING AND MONDAY MORNING. THE NORTHERN TIER...ESPECIALLY THE ICE BOX OF KBFD...COULD GET INTO THE MID 30S BOTH MORNINGS - AND PERHAPS EVEN THE LOWER 30S ON MONDAY MORNING. WHAT MIGHT BE MORE REMARKABLE IS A POTENTIAL 30 TO 40F DIURNAL SWING ON MONDAY AS WINDS TURN TO THE S/SW FOR THE DAYTIME BEFORE THE FRONT ARRIVES AT NIGHT/EARLY TUES. BUT EVEN WITH THE GIANT SWING MONDAY SHOULD END UP JUST SLIGHTLY BELOW NORMAL FOR MAXES. WELCOME AUTUMN. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... THE MVFR CEILINGS REMAIN OVER KBFD LATE THIS EVENING AND WILL LIKELY REMAIN SO OVERNIGHT. ELSEWHERE SCATTERED LOW CLOUDS WILL BE COVERED BY INCREASING MID AND HIGH CLOUDS THROUGH THE LATE EVENING HOURS AHEAD OF ANOTHER DISTURBANCE RACING OUT OF THE UPPER MIDWEST. EXPECT SHOWERS SPREADING ACROSS THE AREA BETWEEN ABOUT 09-15Z SATURDAY MORNING ALONG WITH MVFR/IFR CONDITIONS DEVELOPING. THE SYSTEM BEING A FAST MOVER WILL MOVE THROUGH WITH IMPROVING CONDITIONS SATURDAY AFTERNOON. OUTLOOK... SUN...PATCHY AM FOG...OTHERWISE VFR. MON...NO SIG WX. MON NIGHT - TUE...A COLD FRONT WILL BRING REDUCED CONDITIONS WITH SHOWERS. WED...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/LAMBERT NEAR TERM...GRUMM SHORT TERM...GRUMM/LA CORTE LONG TERM...DANGELO AVIATION...LA CORTE/GARTNER
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1151 PM CDT FRI SEP 12 2014 .AVIATION 06Z DISCUSSION... PVA WILL BE IN PLACE THROUGH 12Z OVERNIGHT AS A WEAK MID LEVEL IMPULSE WILL BE ON APPROACH. AS A RESULT...LOW CIGS WILL PERSIST THROUGH AT LEAST 12Z. THEREAFTER...THE LOW CLOUDINESS WILL STILL BE RATHER TOUGH TO DISLODGE. THE MID AND UPPER FLOW STILL CARRIES A WEAK SOUTHERLY COMPONENT. NEVERTHELESS...CIGS SHOULD BEGIN TO LIFT SOME TOWARD 18Z WITH PARTIAL CLEARING WEST BY 00Z. OTW...ISOLATED SHOWERS HERE AND THERE WILL BE POSSIBLE UNTIL 12Z. HOWEVER...THE EXPECTED COVERAGE DOES NOT WARRANT THE USAGE OF VCNTY...TEMPO OR PROB GROUPS. LOOK FOR CLOUDINESS TO BEGIN TO DECREASE FROM WEST TO EAST AFT 18Z. && .PREV DISCUSSION... /ISSUED 725 PM CDT FRI SEP 12 2014/ UPDATE... LATEST SURFACE OBS AND SATELLITE IMAGERY SHOWS LOW CLOUDS CONTINUE TO BLANKET THE MID STATE...AND ACTUALLY EXTEND NORTHWARD ALL THE WAY INTO CANADA SO THEY WONT BE GOING ANYWHERE ANYTIME SOON. WATER VAPOR IMAGERY THIS EVENING DEPICTS A STRONG TROUGH DIGGING SOUTHWARD INTO IOWA AND MISSOURI. AS THIS TROUGH SWINGS THROUGH THE OHIO AND TENNESSEE VALLEYS OVERNIGHT...EXPECT A FEW LIGHT SHOWERS AND SPRINKLES TO BREAK OUT ACROSS THE MID STATE SIMILAR TO THE MOST RECENT HRRR MODEL RUNS. ALSO ANTICIPATE SOME PATCHY FOG DEVELOPMENT IN THE HIGHER TERRAIN AREAS OF EASTERN ZONES AS DEWPOINT DEPRESSIONS LOWER OVERNIGHT. DESPITE EXTENSIVE CLOUD COVER...CAA WILL INCREASE OVERNIGHT WITH DRIER AIR ADVECTING IN FROM THE NORTH AT THE SURFACE...WHICH SHOULD ALLOW TEMPS TO FALL INTO THE UPPER 50S AND LOWER 60S FOR LOWS. CURRENT FORECAST FOR TONIGHT ALREADY HAS CLOUDS...POPS...AND TEMPS WELL HANDLED...AND ONLY MADE MINOR CHANGES FOR THE OVERNIGHT PERIOD. SHAMBURGER PREV DISCUSSION... /ISSUED 514 PM CDT FRI SEP 12 2014/ AVIATION 00Z DISCUSSION... PVA WILL BE IN PLACE THROUGH 12Z OVERNIGHT AS A WEAK MID LEVEL IMPULSE WILL BE ON APPROACH. AS A RESULT...LOW CIGS WILL PERSIST THROUGH AT LEAST 12Z. THEREAFTER...THE LOW CLOUDINESS WILL STILL BE RATHER TOUGH TO DISLODGE. THE MID AND UPPER FLOW STILL CARRIES A WEAK SOUTHERLY COMPONENT. NEVERTHELESS...CIGS SHOULD BEGIN TO LIFT SOME TOWARD 18Z WITH PARTIAL CLEARING WEST BY 00Z. OTW...ISOLATED SHOWERS HERE AND THERE WILL BE POSSIBLE UNTIL 12Z. HOWEVER...THE EXPECTED COVERAGE DOES NOT WARRANT THE USAGE OF VCNTY...TEMPO OR PROB GROUPS. PREV DISCUSSION... /ISSUED 256 PM CDT FRI SEP 12 2014/ DISCUSSION...IT WAS A CLOUDY DAY ACROSS MID TN WITH TEMPERATURES MAINLY IN THE 70S...WHICH IS 5 TO 10 DEGREES COOLER THAN NORMAL. A COLD FRONT HAD SETTLED WELL TO OUR SOUTHEAST. HIGH PRESSURE WAS LOCATED WELL TO OUR NORTHWEST...CENTERED OVER THE NORTHERN PLAINS. POST FRONTAL MOISTURE LINGERED OVER A WIDE AREA ...AND THIS MOISTURE AND CLOUDINESS WILL REMAIN FOR A WHILE. FOR TONIGHT...CLOUDY SKIES MAY EVENTUALLY PRODUCE A FEW LIGHT SHOWERS OR PATCHY DRIZZLE AS A TROUGH AXIS PASSES ACROSS THE REGION. THE CLOUDS WILL LOWER...AND SHOULD KEEP ANY FOG FORMATION FROM BEING VERY DENSE. LOWS WILL BE A FEW DEGREES COOLER THAN LAST NIGHT. ON SATURDAY...MODELS SHOW A SMALL CHANCE FOR MORNING SHOWERS PLATEAU...THEN DECREASING MOISTURE FROM NW TO SE. WE THINK CLOUDS COULD BE STUBBORN...SO EXPECT OVERCAST SKIES ALL ZONES THROUGH MIDDAY...THEN PARTIAL CLEARING GRADUALLY WORKING FROM NW TO SE ACROSS THE MID STATE THROUGH THE AFTERNOON. HIGH TEMPS WILL AGAIN BE QUITE PLEASANT...IN THE 70S. NORTH BREEZES WILL PICK UP A BIT TO HELP THE CLEARING TREND. WINDS WILL REACH 10-20 MPH IN THE EARLY AFTERNOON. DRY WX WILL CONTINUE THROUGH THE REST OF THE WEEKEND. SATURDAY NIGHT WILL BE A LITTLE CHILLY...WITH LOWS MAINLY LOWER 50S...BUT SOME 40S POSSIBLE AS WELL. SUNDAY WILL BE MAINLY SUNNY AND TEMPS WILL RECOVER TO THE UPPER 70S. LOOKING AHEAD...NEXT WEEK SHOULD BE QUIET IN THE WX DEPARTMENT. A COUPLE OF WAVES AND FRONTS WILL SWING DOWN IN THE NORTHWEST FLOW...BUT NO MAJOR RAINFALL OR TEMPERATURE ANOMALIES ARE EXPECTED. RIGHT NOW...IT LOOKS LIKE THE STRONGEST SYSTEM WILL MOVE THROUGH TUESDAY NIGHT...AND JUST INCLUDING 20 POPS AT THAT TIME. LOWS NEXT WEEK WILL BE MOSTLY IN THE UPPER 50S TO AROUND 60...WITH HIGHS IN THE MID 70S TO LOWER 80S. 13 PREV DISCUSSION... /ISSUED 1233 PM CDT FRI SEP 12 2014/ AVIATION... MVFR-IFR CIGS ARE EXPECTED TO IMPROVE SLIGHTLY THROUGH THIS AFTERNOON...BUT PERSISTENT VFR CIGS ARE NOT EXPECTED IN THE NEAR TERM. WINDS WILL BE STEADY FROM THE NORTH TO NORTHWEST THROUGH THE NIGHT SO VIS REDUCTIONS ARE NOT ANTICIPATED AT BNA OR CKV. FOR CSV EXPECT IFR-LIFR VIS AND CIGS AGAIN DURING THE OVERNIGHT...WITH CONDITIONS IMPROVING AT ALL THREE TAF SITES AFTER 14Z TOMORROW UNDER A STEADY NORTH TO NORTHEASTERLY FLOW. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
235 AM CDT SAT SEP 13 2014 .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 235 AM CDT SAT SEP 13 2014 WATER VAPOR IMAGERY/RAP 500MB ANALYSIS SHOWING DEEP MID-LEVEL TROUGH THAT GAVE THE AREA A CHILLY DAMP FRIDAY NOW OVER UPPER MI. RADAR MOSAIC SHOWING LINGERING RAIN FROM CENTRAL UPPER MI INTO OVER FAR EASTERN WI. IR SATELLITE SHOWED BULK OF LOW CLOUDS ASSOCIATED WITH THIS TROUGH NOW NORTHEAST OF I-94. SURFACE HIGH PRESSURE/CLEARING WAS WORKING INTO THE FORECAST AREA. ARX WEBCAM SHOWING EXTENSIVE MISSISSIPPI RIVER VALLEY FOG WITH THE CLEARING/LIGHT WINDS. FOG WAS HIT AND MISS ACROSS THE REST OF THE FORECAST AREA. OTHERWISE... TEMPERATURES AS OF 2 AM WERE IN THE MIDDLE 30S TO MIDDLE 40S. PLAN ON CONTINUING FROST ADVISORY THROUGH 8 AM THIS MORNING AS TEMPERATURES FALL INTO THE LOWER/MIDDLE 30S. OTHERWISE...PLAN ON A DRY/COOL SATURDAY AS A RIDGE OF HIGH PRESSURE PASSES OVERHEAD. LOOK FOR HIGHS IN THE 55-65 DEGREE RANGE WHICH IS SOME 10-15 DEGREES BELOW THE NORMAL...BUT MUCH BETTER THAN THE CHILLY CONDITIONS SEEN ON FRIDAY. LIGHT SOUTH WINDS/WARM AIR ADVECTION WILL THEN SET UP ACROSS THE AREA TONIGHT AS THE HIGH MOVES INTO THE GREAT LAKES REGION AND A MID- LEVEL/SURFACE TROUGH PUSHES FROM THE NORTHERN PLAINS INTO MN. SOME MID/HIGH CLOUD WILL ALSO BE SEEN MAINLY NORTH OF I-94 IN THE WARM AIR ADVECTION. LOOK FOR LOWS IN THE UPPER 30S TO THE LOWER 40S. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 235 AM CDT SAT SEP 13 2014 MID-LEVEL/SURFACE TROUGH PUSHES INTO THE AREA ON SUNDAY. MODELS SHOWING WEAK 850MB MOISTURE TRANSPORT AND BEST SURFACE CONVERGENCE NORTHEAST OF I-94 FOR A CHANCE OF SHOWERS IN THE AFTERNOON. THE REST OF THE AREA LOOKS TO REMAIN DRY. OTHERWISE...PLAN ON ANOTHER EARLY AUTUMN-LIKE DAY WITH HIGHS TOPPING OFF IN THE 60S. SHOWER CHANCES WILL SPREAD ACROSS THE REST OF THE AREA SUNDAY NIGHT AS THE TROUGH SLIPS SOUTHEAST. LOOK FOR LOWS IN THE 40S TO LOWER 50S. SHOWER CHANCES LOOK TO LINGER INTO MONDAY AS ANOTHER MID-LEVEL TROUGH DROPS INTO THE AREA FROM THE NORTHERN PLAINS. THIS TROUGH INTERACTS WITH THE BAROCLINIC ZONE ACROSS THE SOUTH WITH WEAK FRONTOGENESIS IS NOTED IN THE 850-500MB LAYER PER THE NAM. THE GFS IS A BIT STRONGER WITH THIS. WILL GO WITH A 20-50 POPS FOR NOW MAINLY ALONG/SOUTH OF I-90. PLAN ON HIGHS MONDAY GENERALLY IN THE 60- 65 DEGREE RANGE. FOR THE PERIOD TUESDAY THROUGH FRIDAY... COOL/DRY NORTHWEST FLOW ALOFT WILL PREVAIL TUESDAY INTO WEDNESDAY WITH HIGHS IN THE 60S AND LOWS IN THE UPPER 30S TO MIDDLE 40S. SOME WARMING LOOKS TO TAKE PLACE THURSDAY INTO FRIDAY AS HIGH PRESSURE MOVES OFF TO THE EAST AND A TROUGH MAKES ITS WAY OUT OF THE INTERMOUNTAIN WEST INTO THE PLAINS. INCREASING WARM AIR ADVECTION/MOISTURE TRANSPORT INTO THE REGION MAY PUSH A FEW SHOWERS INTO THE AREA LATER THURSDAY NIGHT INTO FRIDAY. LOOK FOR HIGHS THURSDAY IN THE 60S AND MID 60S TO THE LOWER 70S ON FRIDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1140 PM CDT FRI SEP 12 2014 WITH CLOUDS HOLDING T/TD SPREADS CLOSE THROUGH THE DAY...AND CLEARING SKIES JUST IN TIME FOR NIGHTTIME...ITS A FAVORABLE SETUP FOR DIURNAL COOLING INDUCED RIVER VALLEY FOG. NOT AS MUCH T/TD SPREAD TO MAKEUP - ONLY 3 DEGREES AT 04Z. SFC WINDS WILL BE LIGHT THROUGH THE NIGHT. HOWEVER...A SIGNIFICANT DRAWBACK WILL BE THE DEPTH OF THE LIGHT WIND LAYER. RAP BUFKIT SOUNDINGS CONTINUE TO BRING 10+ KTS OF WIND BY 300 FT FOR MOST OF THE NIGHT. THE NAM HAS A SLIGHTLY DEEPER LIGHT WIND FOR THE FIRST PART OF THE OVERNIGHT...DECREASING BEFORE 12Z. GENERALLY - THE SHALLOWER THE LIGHT WIND LAYER...THE LESS FAVORABLE FOR DENSE FOG. CLOUDS AREN/T COMPLETELY CLEAR EITHER...WITH SCATTERED PATCHES MOVING OVERHEAD. CERTAINLY...SOME VSBY RESTRICTIONS ARE LIKELY...AND COULD SEE THICKER FOG/STRATUS BANK SITTING ON THE MISSISSIPPI RIVER...BUT UNSURE IF IT WILL SPREAD ACROSS KLSE. THIS COULD BE A SCENARIO WHERE VSBYS DO DROP TO 1/4SM BRIEFLY...THEN BACK UP TO P6SM...THEN 2SM...AS FOG SLOSHES AROUND. CONFIDENCE LOW IN HOW THIS WILL PLAYOUT...SO WILL LIKELY HOLD WITH MVFR VSBYS AND BCFG FOR NOW. SOMETHING TO WATCH CLOSELY TONIGHT. HIGH PRESSURE BUILDS IN SATURDAY...AND WILL RESULT IN VFR CONDITIONS OUTSIDE OF THE EARLY MORNING FOG POTENTIAL. WINDS WILL GRADUALLY SWING FROM WEST TO SOUTHWEST. LATER SAT NIGHT...SOME CIGS NEAR 4KFT COULD RETURN AS LOW LEVEL WARM AIR ADVECTION AND WEAK MOISTURE TRANSPORT LEAD A SHORTWAVE MOVING EAST ACROSS THE NORTHERN PLAINS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...FROST ADVISORY FROM 3 AM TO 8 AM CDT SATURDAY FOR WIZ017-029-033- 034-042>044. MN...FROST ADVISORY FROM 3 AM TO 8 AM CDT SATURDAY FOR MNZ086-087-094- 095. IA...FROST ADVISORY FROM 3 AM TO 8 AM CDT SATURDAY FOR IAZ008>010-018- 019-029. && $$ SHORT TERM...DAS LONG TERM...DAS AVIATION...RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1140 PM CDT FRI SEP 12 2014 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 257 PM CDT FRI SEP 12 2014 MAIN FORECAST CONCERNS ARE FROST AND FOG POTENTIAL TONIGHT. LATEST WATER VAPOR SATELLITE IMAGERY SHOWING VIGOROUS SHORTWAVE TROUGH OVER THE NORTHERN PLAINS. MOSAIC RADAR INDICATING FRONTOGENETICAL BAND OF RAIN EXTENDING FROM NORTHEAST WISCONSIN INTO NORTHEAST IOWA PER 12.15Z RAP 700-600MB FN VECTOR CONVERGENCE. ALSO...MOSAIC RADAR SHOWING DIURNALLY DRIVEN SCATTERED SHOWERS OVER CENTRAL MINNESOTA UNDERNEATH MAIN SHORTWAVE TROUGH. TONIGHT...SHORTWAVE TROUGH AND ASSOCIATED LOW LEVEL MOISTURE/RAIN PROGGED TO PUSH QUICKLY EAST INTO MICHIGAN THIS EVENING PER THE LATEST 12.12Z GFS/NAM AND 12.15Z RAP RELATIVE HUMIDITY FIELDS. THIS IS EVIDENT PER LATEST VISIBLE SATELLITE IMAGERY SHOWING DIURNAL CUMULUS FIELD WEST OF A LINE FROM FAIRMONT MINNESOTA TO NEAR DULUTH MINNESOTA. THIS CUMULUS FIELD WILL QUICKLY EVAPORATE DUE TO LOSS OF DAYTIME HEATING THIS EVENING AND ALLOW SKIES TO CLEAR WEST TO EAST ACROSS THE FORECAST AREA. SURFACE RIDGE BUILDS INTO THE FORECAST AREA BY 06Z AND PRODUCE CALM WINDS AND DRIER AIRMASS TO ADVECT IN. TEMPERATURES WILL BE ABLE TO FALL RAPIDLY INTO THE 30S AND THE UPPER 20S IN THE COLD SPOTS OF CENTRAL WISCONSIN. FOR THIS...A FROST ADVISORY WILL BE IN EFFECT FOR PORTIONS OF SOUTHEAST MINNESOTA...NORTHEAST IOWA AND CENTRAL WISCONSIN TONIGHT. IN ADDITION...THE COMBINATION OF RAIN TODAY...CALM WINDS AND INVERSION DEVELOPING TONIGHT PER BUFKIT SOUNDINGS...AREAS OF FOG WILL DEVELOP IN RIVER VALLEYS AND PARTS OF CENTRAL WISCONSIN AFTER 06Z. DRY WEATHER CONDITIONS AND UNSEASONABLY COOL TEMPERATURES WILL PREVAIL ACROSS THE AREA SATURDAY...AS SURFACE RIDGE REMAINS IN CONTROL. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 257 PM CDT FRI SEP 12 2014 WARMER AIR ADVECTS INTO THE FORECAST AREA SUNDAY OUT AHEAD OF NEXT SHORTWAVE TROUGH TO AFFECT THE REGION. TEMPERATURES WILL BE A FEW DEGREES WARMER AND SLIGHTLY BELOW NORMAL. NEXT CONCERN IS SHORTWAVE TROUGH MOVING OVER THE GREAT LAKES REGION EMBEDDED IN THE WEST TO NORTHWEST FLOW SUNDAY NIGHT INTO MONDAY. BOTH THE 12.12Z GFS/NAM SHOW STRONG PV ADVECTION/QG FORCING AND FN CONVERGENCE FOCUSED OVER THE SOUTHERN HALF OF THE FORECAST AREA. SOME SLIGHT DIFFERENCES OCCUR WITH THE PLACEMENT AND TIMING OF SURFACE FEATURES BETWEEN THE 12.12Z GFS/NAM/ECMWF. WITH THE MODELS CONTINUE TO SHOW DECENT DYNAMIC FORCING/LIFT IN ASSOCIATED WITH SHORTWAVE TROUGH...WILL MAINTAIN PRECIPITATION CHANCES SUNDAY INTO MONDAY MAINLY FOR THE SOUTHERN HALF OF THE FORECAST AREA. MAIN FORECAST CONCERN ARE PRECIPITATION CHANCES FRIDAY...OTHERWISE TEMPERATURES TUESDAY THROUGH FRIDAY. THE 12.12Z GFS/GEM/ECMWF CONTINUE TO HAVE GOOD RUN TO RUN CONSISTENCY IN DIGGING UPPER LEVEL TROUGH OVER THE NORTHEAST UNITED STATES AND GREAT LAKES REGION AND SURFACE RIDGE DOMINATING THE UPPER MIDWEST TUESDAY THROUGH THURSDAY. WITH SUBSIDENCE OVER THE FORECAST AREA...DUE TO SURFACE RIDGE...DRY WEATHER CONDITIONS CAN BE EXPECTED ACROSS THE FORECAST AREA DURING THIS TIME FRAME. TEMPERATURES SHOULD BE NEAR OR SLIGHTLY BELOW NORMAL TUESDAY THROUGH THURSDAY...AS THE 12.00Z GFS/GEM/ECMWF INDICATE 850MB TEMPERATURES RANGING FROM PLUS 5 TO PLUS 10 DEGREES CELSIUS AND 12.12Z GEFS SHOW STANDARD ANOMALIES OF MINUS 0.5 TO MINUS 1 DEGREE CELSIUS. SIGNIFICANT DIFFERENCES SHOW UP BETWEEN THE 12.12Z GFS/ECMWF FRIDAY...AS THE 12.12Z GFS MORE AMPLIFIED WITH UPPER LEVEL RIDGE OVER THE UPPER MIDWEST THAN THE ECMWF AND THE 12.12Z ECMWF IS SLOWER IN PROGRESSING THE UPPER LEVEL RIDGE INTO THE UPPER MIDWEST AND GREAT LAKES REGION. THIS HAS IMPACTS ON HOW FAST WARMER AIR ADVECTS INTO THE REGION AND TIMING OF SURFACE WARM FRONT INTO THE FORECAST AREA. THIS SURFACE WARM FRONT WILL BE THE FOCUS OF PRECIPITATION CHANCES FRIDAY...WITH BOTH THE 12.12Z GFS/ECMWF INDICATE DECENT 850MB MOISTURE TRANSPORT AND CONVERGENCE IN ASSOCIATION WITH IMPULSE OVER THE NORTHERN PLAINS AND NORTHERN ROCKIES. CONFIDENCE IN FORECAST ON FRIDAY IS LOW DUE TO TIMING AND STRENGTH OF UPPER LEVEL RIDGE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1140 PM CDT FRI SEP 12 2014 WITH CLOUDS HOLDING T/TD SPREADS CLOSE THROUGH THE DAY...AND CLEARING SKIES JUST IN TIME FOR NIGHTTIME...ITS A FAVORABLE SETUP FOR DIURNAL COOLING INDUCED RIVER VALLEY FOG. NOT AS MUCH T/TD SPREAD TO MAKEUP - ONLY 3 DEGREES AT 04Z. SFC WINDS WILL BE LIGHT THROUGH THE NIGHT. HOWEVER...A SIGNIFICANT DRAWBACK WILL BE THE DEPTH OF THE LIGHT WIND LAYER. RAP BUFKIT SOUNDINGS CONTINUE TO BRING 10+ KTS OF WIND BY 300 FT FOR MOST OF THE NIGHT. THE NAM HAS A SLIGHTLY DEEPER LIGHT WIND FOR THE FIRST PART OF THE OVERNIGHT...DECREASING BEFORE 12Z. GENERALLY - THE SHALLOWER THE LIGHT WIND LAYER...THE LESS FAVORABLE FOR DENSE FOG. CLOUDS AREN/T COMPLETELY CLEAR EITHER...WITH SCATTERED PATCHES MOVING OVERHEAD. CERTAINLY...SOME VSBY RESTRICTIONS ARE LIKELY...AND COULD SEE THICKER FOG/STRATUS BANK SITTING ON THE MISSISSIPPI RIVER...BUT UNSURE IF IT WILL SPREAD ACROSS KLSE. THIS COULD BE A SCENARIO WHERE VSBYS DO DROP TO 1/4SM BRIEFLY...THEN BACK UP TO P6SM...THEN 2SM...AS FOG SLOSHES AROUND. CONFIDENCE LOW IN HOW THIS WILL PLAYOUT...SO WILL LIKELY HOLD WITH MVFR VSBYS AND BCFG FOR NOW. SOMETHING TO WATCH CLOSELY TONIGHT. HIGH PRESSURE BUILDS IN SATURDAY...AND WILL RESULT IN VFR CONDITIONS OUTSIDE OF THE EARLY MORNING FOG POTENTIAL. WINDS WILL GRADUALLY SWING FROM WEST TO SOUTHWEST. LATER SAT NIGHT...SOME CIGS NEAR 4KFT COULD RETURN AS LOW LEVEL WARM AIR ADVECTION AND WEAK MOISTURE TRANSPORT LEAD A SHORTWAVE MOVING EAST ACROSS THE NORTHERN PLAINS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...FROST ADVISORY FROM 3 AM TO 8 AM CDT SATURDAY FOR WIZ017-029-033- 034-042>044. MN...FROST ADVISORY FROM 3 AM TO 8 AM CDT SATURDAY FOR MNZ086-087-094- 095. IA...FROST ADVISORY FROM 3 AM TO 8 AM CDT SATURDAY FOR IAZ008>010-018- 019-029. && $$ SHORT TERM...DTJ LONG TERM...DTJ AVIATION...RIECK
AREA FORECAST DISCUSSION
NWS MIAMI FL
1105 AM EDT SAT SEP 13 2014 .UPDATE... WHILE SHOWER AND THUNDERSTORM ACTIVITY HAS SUBSIDED ACROSS THE REGION THIS MORNING...THE POTENTIAL FOR ACTIVE CONVECTION CONTINUES. RECENT VISIBLE SATELLITE IMAGERY INDICATES ACTIVE CONVECTION IN THE EASTERN GULF ASSOCIATED WITH THE AREA OF LOW PRESSURE OFF THE SOUTHWEST FLORIDA COAST AND ADDITIONAL CONVECTION IN THE CENTRAL BAHAMAS ISLANDS. THE 12Z SOUNDING INDICATED A PWAT AROUND 1.9 INCHES AND INDICATED A SIGNIFICANT COOLING TREND IN THE MID LEVELS AS WELL. GIVEN THE GENERAL CLEARING TREND OVER THE PENINSULA THIS MORNING...DAY TIME HEATING IS EXPECTED TO DRIVE CONVECTION THIS AFTERNOON AND EARLY EVENING WITH THE GREATEST COVERAGE OF SHOWERS AND THUNDERSTORMS STILL EXPECTED IN THE WESTERN INTERIOR AND WESTERN PORTIONS OF THE PENINSULA...INCLUDING THE NAPLES METRO AREAS. 60 && .PREV DISCUSSION... /ISSUED 830 AM EDT SAT SEP 13 2014/ AVIATION... RATHER DISORGANIZED UPPER LOW, WITH A FEW DISTURBANCES TRAILING TO THE EAST, WILL BE THE IMPETUS FOR STORMS TODAY. LARGE MASS OF MID LEVEL DRY AIR PER WATER VAPOR LOOP, MAY STAY NORTH OF THE REGION TODAY, UNLIKE YESTERDAY. PERHAPS SOME OF THIS DRY AIR WILL WRAP INTO THE CIRCULATION OF THE UPPER LOW, BUT THAT MAY NOT MEAN MUCH SINCE THE LOW IS ALREADY OFF THE SW FL COAST. LAMP GUIDANCE INDICATES THAT A SEA BREEZE WILL DEVELOP ALONG THE EAST COAST, PERHAPS KEEPING MOST CONVECTION INLAND AND WEST COAST. THIS IS UP AGAINST THE HRRR WHICH IS AGGRESSIVE PAINTING STORMS ALONG THE BEACHES AND MOST TERMINALS BY MID AFTERNOON. THE TAFS CAN BE FINE TUNED ONCE RAOB DATA ARRIVES, BUT WILL INSERT VCTS FOR NOW, AS PREVIOUS DISCUSSION MENTIONED VCTS FOR ALL TAFS, BUT TAFS ONLY CONTAINED VCSH. PERHAPS SOME OF THE SHOWERS OFFSHORE OF PBI ARRIVE LATER THIS MORNING. PERSISTENCE OF CLOUD COVER ALONG THE EAST COAST WILL ALSO GO A LONG WAY IN DETERMINING STORM EVOLUTION TODAY. CONFIDENCE IS BELOW AVERAGE. PREV DISCUSSION... /ISSUED 431 AM EDT SAT SEP 13 2014/ SHORT TERM...(TODAY-MONDAY) RECENTLY ANIMATED WATER VAPOR LOOP SHOWED AN UPPER LOW CENTERED OVER SOUTH FLORIDA SLOWLY TRACKING WESTWARD AND A RIDGE AXIS ORIENTED FROM EAST TO WEST ACROSS THE NORTHERN GULF COAST STATES. PLENTY OF DEEP LAYER MOISTURE EAST OF THIS UPPER LOW COMBINED WITH UPPER-LEVEL DIVERGENCE WILL CONTINUE TO SUPPORT WIDESPREAD RAINFALL TODAY .ESPECIALLY ALONG THE SOUTHEAST COAST AND ACROSS THE ATLANTIC WATERS THROUGH THE MORNING HOURS. THE LATEST HRRR MODEL RUN APPEARS TO HAVE INITIALIZED WELL WITH THE CURRENT RADAR TRENDS AND GENERALLY INDICATES THIS MORNING ACTIVITY CONTINUING ACROSS THE EASTERN AREAS INCLUDING PALM BEACH, BROWARD AND MIAMI-DADE BEFORE SHIFTING INLAND AND TOWARD THE GULF COAST THROUGH THE MID TO LATE AFTERNOON/EARLY EVENING PERIOD. THIS SOLUTION MAKES SENSE WITH THE UPPER LOW SHIFTING WESTWARD AND LIGHT TO MODERATE SOUTHEAST LOW- LEVEL FLOW CONTINUING. THIS PATTERN WILL KEEP THE POTENTIAL FOR LOCALIZED FLOODING UP THROUGH THIS EVENING...ESPECIALLY OVER THE AREAS THAT ARE ALREADY SATURATED FROM EARLIER RAINFALL (AREAS HAVE RECEIVED 2-4 INCHES WITH HIGHER AMOUNTS UP TO 7" JUST INLAND OF BOCA RATON OVER THE PAST 24-36 HRS). MODEL SOUNDINGS SUPPORT THE ACTIVITY TAPERING OFF OVER THE FAR SOUTHEASTERN AREAS OR TOWARD MIAMI THROUGH THE MORNING AND AFTERNOON HOURS WITH MAINLY SATURATED PROFILES ABOVE A SLIGHTLY DRIER LAYER FROM THE SURFACE TO 700MB. AS A RESULT...MAXIMUM TEMPERATURES HAVE BEEN SLIGHTLY UNDERCUT BY A FEW DEGREES COMPARED TO GUIDANCE...MAINLY DUE TO PLENTY OF CLOUD COVERAGE ANTICIPATED. IF THIS COVERAGE BEGINS TO BREAK THROUGH THE DAY...TEMPERATURES WILL NEED TO BE ADJUSTED ACCORDINGLY. THE MOIST TREND WITH SOUTHEAST FLOW WILL PERSIST THROUGH SUNDAY BEFORE SOME DRIER AIR MOVES IN FROM THE WEST AND THE RIDGE BUILDS BACK ACROSS THE REGION INTO THE UPCOMING WEEK. /85 LONG TERM (TUESDAY-FRIDAY)... THE LATEST EXTENDED GUIDANCE REMAINS IN DECENT AGREEMENT ON THE LARGE SCALE AND GENERALLY INDICATES FALLING UPPER HEIGHTS IN RESPONSE TO A DEEPENING UPPER TROUGH ACROSS THE REGION. A FRONTAL BOUNDARY IS PROJECTED TO SHIFT SOUTHWARD AND STALL NORTH OF THE AREA THROUGH THE SECOND HALF OF THE WEEK. THE ECMWF SEEMS TO BE THE MORE BULLISH SOLUTION AND SHOWS THE MOISTURE AXIS ASSOCIATED WITH THIS BOUNDARY PROGRESSING FARTHER SOUTH THAN THE GFS/GFS ENSEMBLE MEAN WITH SSW LOW-LEVEL FLOW SETTING UP OVER THE AREA BY THURSDAY. THE COMBINATION OF THE FRONT AND FALLING UPPER HEIGHTS ALONG WITH SSW LOW-LEVEL FLOW WOULD FAVOR MUCH OF THE RAINFALL SETTING UP OVER THE EAST COAST/METRO AREAS BY THURSDAY. /85 AVIATION... A LARGE AREA OF SHOWERS AND THUNDERSTORMS OVER THE ATLANTIC WATERS WERE DEVELOPING ON THE NORTHEAST SIDE OF THE MID/UPPER LEVEL VORTICITY MOVING WEST ACROSS THE FLORIDA STRAITS. THESE SHOWERS/STORMS WERE MOVING QUICKLY TO THE NORTHWEST TOWARDS THE BROWARD AND MIAMI-DADE TAF SITES...AND THEY MAY MOVE OVER THE TAF SITES THROUGH THE EARLY MORNING HOURS. BRIEF MVFR/IFR CONDITIONS AND GUSTY WINDS UP TO 30 KNOTS ARE POSSIBLE. THE AREA OF LOW PRESSURE OVER THE SOUTHEAST GULF AND THE UPPER LEVEL LOW WILL CONTINUE TO MOVE WEST TODAY AND HAVE LESS OF AN INFLUENCE OVER THE REGION THROUGHOUT THE DAY. THIS COMBINED WITH THE OVERNIGHT CONVECTION MAY LIMIT SHOWER/STORM DEVELOPMENT FOR THE EAST COAST METRO AREAS DURING THE DAY. HOWEVER...DEEP MOISTURE IN THE SOUTHEAST LOW LEVEL FLOW WILL CONTINUE...SO KEPT VCTS IN FOR THE TAF SITES. AT KAPF...SHOWER AND STORM DEVELOPMENT IS FORECAST TO BECOME MORE LIKELY AS THE DAY PROGRESSES...AS THE INFLUENCE OF THE UPPER LOW INCREASES. LIGHT WINDS WILL CONTINUE THROUGH THE OVERNIGHT HOURS OUTSIDE OF SHOWERS AND STORMS...AND THEN BECOME SOUTHEAST AROUND 10 KNOTS DURING THE DAY. /84 MARINE... AN UPPER LOW WILL KEEP THE RAIN CHANCES IN THE FORECAST ACROSS THE MARINE AREAS THROUGH THE REMAINDER OF THE WEEKEND WITH LIGHT TO MODERATE SOUTHEAST WINDS CONTINUING. WINDS AND SEAS WILL BE LOCALLY HIGHER IN AND AROUND HEAVIER SHOWERS AND STORMS. HIGH PRESSURE WILL BUILD BACK ACROSS THE REGION THROUGH THE FIRST HALF OF THE UPCOMING WEEK WITH SOUTHEAST WINDS CONTINUING. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 87 76 87 76 / 40 30 50 30 FORT LAUDERDALE 87 77 87 79 / 40 40 60 20 MIAMI 85 77 87 78 / 40 40 60 20 NAPLES 87 75 89 76 / 70 30 60 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...21/KM LONG TERM....60/BD
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1030 AM EDT Sat Sep 13 2014 .Near Term [Rest of Today]... The previous forecast remains largely on track, so only minor tweaks were made. The leading edge of an expansive stratus deck, roughly marking the location of a quasi-stationary front, extended from near Mobile to near Atlanta this morning. When combined with 14Z objective MSAS analysis of MSLP and observed winds, this places the front very close to the northwest corner of our forecast area. The environment along and immediately southeast of the front is characterized by mid-70s surface dewpoints and PWATs around 2" (per GOES sounder). Meanwhile, some drier air was encroaching on the southeast part of the forecast area based on the latest water vapor loops and objective RAP analysis. Tallahassee appeared to be on the cusp of the drier air, with a PWAT of 1.9" on the 12Z sounding. Therefore, the higher rain chances that were already included in the northwest half of the forecast area seem on track at this time. Convection-allowing models (CAM) almost unanimously show fairly widespread thunderstorm activity just ahead of the front in our SE Alabama and western Florida Panhandle zones after about 19-20Z. They also agree that the storms are likely to linger until a few hours after sunset again, particularly in the Florida Panhandle. PoPs were bumped up in the Florida Panhandle for the evening hours. With less convective coverage in the Florida Big Bend and south-central Georgia, those areas could see highs in the mid-90s again. To the north and west, highs should be from around 90 to the lower 90s. The 12Z Tallahassee sounding did indicate stronger E-NE flow than yesterday, likely due to the influence of the passing tropical wave to the south of the area. However, radar VWPs and RAP analysis place the axis of the deep mid-upper level ridge near the northwest corner of our forecast area with a notable weakness in the flow. This will likely lead to slow storm motions in the region with the highest PoPs. Slow storm motions, storm-scale interactions, and the moist environment will provide adequate ingredients for localized heavy rainfall. The heavy rain wording was maintained in the forecast. Some CAMs indicate rainfall rates as high as 4-5" in just under 2 hours, so isolated flash flooding will be possible. However, the threat is expected to be isolated enough to preclude the issuance of a Flash Flood Watch. && .Prev Discussion [642 AM EDT]... .Short Term [Tonight Through Monday]... Although weak upper level ridging will continue to dominate the northern Gulf Coast and SE U.S during the remainder of the weekend and into early next week (before it is eventually replaced by a trof towards mid week), plenty of deep layer tropical moisture will continue to flow into the region from the Gulf of Mexico and western Atlantic. This will keep PoPs above climo through the short term period with daytime rain chances generally in the 40-50% range, with decent PoPs continuing well into the evening hours, especially tonight over NW portions of the CWA. Temps are expected to remain above normal as well, with highs mainly in the lower to a few mid 90s away from the coast, with overnight lows in the lower to middle 70s. .Long Term [Monday Night Through Friday]... The main uncertainty for the extended forecast is to what extent the weak system moving westward into the Gulf will impact our area. The collaborated NHC/WPC forecast takes the system westward to a position south of Houston by mid-week and keeps it weak. Deep moisture will continue to increase across the area with a stalled frontal boundary also in the vicinity. These ingredients point to an unsettled period coming up with an above average chance of rain by mid-week. Some locally heavy rain is possible given the weak boundary and deep tropical moisture expected to be in place. This could be further enhanced by the Gulf system depending on its evolution, but that evolution is much more uncertain. Daytime highs are expected to be held down in the mid 80s from Tuesday through most of the week given the expected cloud cover and increased rain coverage. .Aviation... [through 12z Sunday] Other than brief patchy fog early, generally VFR conditions are expected. Scattered to numerous SHRA/TSRA will develop this afternoon & evening across southeast AL, the FL Panhandle, & southwest GA, affecting KDHN, KABY, & KECP with occasional gusty winds, low cigs, and poor vis. Elsewhere VFR conditions will continue. SHRA/TSRA should slowly diminish around midnight or shortly after. .Marine... Winds and seas will be slightly elevated this weekend as a weak tropical disturbance passes well to the south of the coastal waters. Thereafter, a very weak surface pressure pattern will return to the marine area, with typically low summertime winds and seas expected once again. .Fire Weather... Red Flag conditions are not expected through at least this weekend. .Hydrology... As mentioned above, some locally heavy rainfall (with up to 2" to 4" amounts) will be possible today in some of the slow moving storms to the north and west of Tallahassee, but any heavy amounts should be isolated in nature and not have much of a hydrological impact through early next week. By the middle of the week, however, an upper level trof will replace the current ridge which will be retreating westward, and before the cooler and drier air is allowed to seep into the region by late in the week or next weekend, more widespread heavy rainfall could fall over the CWA. Should this occur, some more significant rises along area rivers and streams could take place, so this situation will be worth monitoring. && .Preliminary Point Temps/PoPs... Tallahassee 96 73 93 72 92 / 20 30 40 20 50 Panama City 90 76 89 76 89 / 40 60 40 20 50 Dothan 91 72 92 72 92 / 70 60 50 30 50 Albany 92 72 92 73 92 / 50 50 50 30 50 Valdosta 95 71 94 71 93 / 20 30 40 30 50 Cross City 93 72 92 71 92 / 30 40 40 20 50 Apalachicola 90 77 89 76 88 / 20 20 40 20 40 && .TAE Watches/Warnings/Advisories... FL...None. GA...None. AL...None. GM...None. && $$ NEAR TERM...LAMERS SHORT TERM...GOULD LONG TERM...DVD AVIATION...FOURNIER MARINE...GOULD FIRE WEATHER...FOURNIER HYDROLOGY...GOULD
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1019 AM EDT SAT SEP 13 2014 .DISCUSSION... .UPDATE... MORNING SOUNDINGS FROM TAMPA AND THE CAPE INDICATE PRECIPITABLE WATER VALUES RANGING FROM 1.83 TO 1.96 INCHES AND WITH SOUTHERLY LOW LVL FLOW BACKING TO THE E/ENE ABOVE 700 MBS. AT THE SFC...SOUTHERLY FLOW THIS MORNING IS FORECAST TO BECOME SE THIS AFTERNOON WITH FLOW AROUND THE ATLC RIDGE. THE LOW LVL FLOW IS ALSO FORECAST TO BECOME SE BY THIS AFTERNOON WHICH WILL ALLOWS THE EAST COAST SEA BREEZE TO DEVELOP AND PUSH INTO THE INTERIOR DURING THE MID TO LATE AFTN HOURS TODAY. IN THE UPPER LEVELS...AN UPPER LEVEL LOW OFF THE SW FL COAST IS FORECAST TO MOVE SW WITH ANOTHER UPPER LVL LOW WELL NE FROM THE NRN BAHAMAS FORECAST TO ALSO GENERALLY MOVE SW THIS AFTN AND EVENING. THESE FEATURES MAY PROVIDE SOME ADDITIONAL LIFT ACROSS OUR FAR SRN ZONES WHERE THE DEEPEST MOISTURE WILL RESIDE TODAY. CURRENT FORECAST LOOKS ON TRACK WITH ONLY SOME SMALL TWEAKS TO POPS/TEMPS. LOWEST RAIN CHANCES EXPECTED ALONG THE VOLUSIA COUNTY COAST AND HIGHEST RAIN CHANCES AROUND 40 PCT FROM THE SRN INTERIOR INTO LAKE COUNTY. && .AVIATION...CURRENT TERMINALS HAVE VCTS IN FOR PORTIONS OF THE AFTERNOON ALONG SRN TERMINALS BY MID DAY AND INTERIOR TERMINALS THIS AFTERNOON. RECENT HRRR MODEL RUNS SUGGEST SCT SHRA/TSRA SHOULD DVLP OVER THE INTERIOR BY MID AFTN AND PUSH WESTWARD TWD LAKE COUNTY AND KLEE VCTY BY LATE AFTERNOON. WILL MONITOR TRENDS AND MAY ADD SHORT TEMPO GROUP FOR TSRA AT KLEE LATER THIS AFTN. OTHERWISE EXPECT MAINLY VFR CONDS OUTSIDE OF SCATTERED CONVECTION MOVING WESTWARD ACROSS THE INTERIOR IN THE MID-LATE AFTERNOON. && .MARINE...S WINDS AT 6-10 KNOTS AT BUOY 41009 THE LAST SEVERAL HOURS WITH SEAS AROUND 2.6 FT. WINDS WILL BECOME SE AROUND 10 KNOTS WITH SEAS MAINLY AROUND 2 FT...POSSIBLY UP TO 2-3 FT OFFSHORE ACROSS THE NRN OFFSHORE WATERS. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ VOLKMER/SEDLOCK
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1015 AM EDT SAT SEP 13 2014 .DISCUSSION... .UPDATE... MORNING SOUNDINGS FROM TAMPA AND THE CAPE INDICATE PRECIPITABLE WATER VALUES RANGING FROM 1.83 TO 1.96 INCHES AND WITH SOUTHERLY LOW LVL FLOW BACKING TO THE E/ENE ABOVE 700 MBS. AT THE SFC...SOUTHERLY FLOW THIS MORNING IS FORECAST TO BECOME SE THIS AFTERNOON WITH FLOW AROUND THE ATLC RIDGE. THE LOW LVL FLOW IS ALSO FORECAST TO BECOME SE BY THIS AFTERNOON WHICH WILL ALLOWS THE EAST COAST SEA BREEZE TO DEVELOP AND PUSH INTO THE INTERIOR DURING THE MID TO LATE AFTN HOURS TODAY. IN THE UPPER LEVELS...AN UPPER LEVEL LOW OFF THE SW FL COAST IS FORECAST TO MOVE SW WITH ANOTHER UPPER LVL LOW WELL NE FROM THE NRN BAHAMAS FORECAST TO ALSO GENERALLY MOVE SW THIS AFTN AND EVENING. THIS FEATURES MAY PROVIDE SOME ADDITIONAL LIFT ACROSS OUR FAR SRN ZONES WHERE THE DEEPEST MOISTURE WILL RESIDE TODAY. CURRENT FORECAST LOOKS ON TRACK WITH ONLY SOME SMALL TWEAKS TO POPS/TEMPS. LOWEST RAIN CHANCES EXPECTED ALONG THE VOLUSIA COUNTY COAST AND HIGHEST RAIN CHANCES AROUND 40 PCT FROM THE SRN INTERIOR INTO LAKE COUNTY. && .AVIATION...CURRENT TERMINALS HAVE VCTS IN FOR PORTIONS OF THE AFTERNOON ALONG SRN TERMINALS BY MID DAY AND INTERIOR TERMINALS THIS AFTERNOON. RECENT HRRR MODEL RUNS SUGGEST SCT SHRA/TSRA SHOULD DVLP OVER THE INTERIOR BY MID AFTN AND PUSH WESTWARD TWD LAKE COUNTY AND KLEE VCTY BY LATE AFTERNOON. WILL MONITOR TRENDS AND MAY ADD SHORT TEMPO GROUP FOR TSRA AT KLEE LATER THIS AFTN. OTHERWISE EXPECT MAINLY VFR CONDS OUTSIDE OF SCATTERED CONVECTION MOVING WESTWARD ACROSS THE INTERIOR IN THE MID-LATE AFTERNOON. && .MARINE...S WINDS AT 6-10 KNOTS AT BUOY 41009 THE LAST SEVERAL HOURS WITH SEAS AROUND 2.6 FT. WINDS WILL BECOME SE AROUND 10 KNOTS WITH SEAS MAINLY AROUND 2 FT...POSSIBLY UP TO 2-3 FT OFFSHORE ACROSS THE NRN OFFSHORE WATERS. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ VOLKMER/SEDLOCK
AREA FORECAST DISCUSSION
NWS MIAMI FL
830 AM EDT SAT SEP 13 2014 .AVIATION... RATHER DISORGANIZED UPPER LOW, WITH A FEW DISTURBANCES TRAILING TO THE EAST, WILL BE THE IMPETUS FOR STORMS TODAY. LARGE MASS OF MID LEVEL DRY AIR PER WATER VAPOR LOOP, MAY STAY NORTH OF THE REGION TODAY, UNLIKE YESTERDAY. PERHAPS SOME OF THIS DRY AIR WILL WRAP INTO THE CIRCULATION OF THE UPPER LOW, BUT THAT MAY NOT MEAN MUCH SINCE THE LOW IS ALREADY OFF THE SW FL COAST. LAMP GUIDANCE INDICATES THAT A SEA BREEZE WILL DEVELOP ALONG THE EAST COAST, PERHAPS KEEPING MOST CONVECTION INLAND AND WEST COAST. THIS IS UP AGAINST THE HRRR WHICH IS AGGRESSIVE PAINTING STORMS ALONG THE BEACHES AND MOST TERMINALS BY MID AFTERNOON. THE TAFS CAN BE FINE TUNED ONCE RAOB DATA ARRIVES, BUT WILL INSERT VCTS FOR NOW, AS PREVIOUS DISCUSSION MENTIONED VCTS FOR ALL TAFS, BUT TAFS ONLY CONTAINED VCSH. PERHAPS SOME OF THE SHOWERS OFFSHORE OF PBI ARRIVE LATER THIS MORNING. PERSISTENCE OF CLOUD COVER ALONG THE EAST COAST WILL ALSO GO A LONG WAY IN DETERMINING STORM EVOLUTION TODAY. CONFIDENCE IS BELOW AVERAGE. && .PREV DISCUSSION... /ISSUED 431 AM EDT SAT SEP 13 2014/ SHORT TERM...(TODAY-MONDAY) RECENTLY ANIMATED WATER VAPOR LOOP SHOWED AN UPPER LOW CENTERED OVER SOUTH FLORIDA SLOWLY TRACKING WESTWARD AND A RIDGE AXIS ORIENTED FROM EAST TO WEST ACROSS THE NORTHERN GULF COAST STATES. PLENTY OF DEEP LAYER MOISTURE EAST OF THIS UPPER LOW COMBINED WITH UPPER-LEVEL DIVERGENCE WILL CONTINUE TO SUPPORT WIDESPREAD RAINFALL TODAY ..ESPECIALLY ALONG THE SOUTHEAST COAST AND ACROSS THE ATLANTIC WATERS THROUGH THE MORNING HOURS. THE LATEST HRRR MODEL RUN APPEARS TO HAVE INITIALIZED WELL WITH THE CURRENT RADAR TRENDS AND GENERALLY INDICATES THIS MORNING ACTIVITY CONTINUING ACROSS THE EASTERN AREAS INCLUDING PALM BEACH, BROWARD AND MIAMI-DADE BEFORE SHIFTING INLAND AND TOWARD THE GULF COAST THROUGH THE MID TO LATE AFTERNOON/EARLY EVENING PERIOD. THIS SOLUTION MAKES SENSE WITH THE UPPER LOW SHIFTING WESTWARD AND LIGHT TO MODERATE SOUTHEAST LOW- LEVEL FLOW CONTINUING. THIS PATTERN WILL KEEP THE POTENTIAL FOR LOCALIZED FLOODING UP THROUGH THIS EVENING...ESPECIALLY OVER THE AREAS THAT ARE ALREADY SATURATED FROM EARLIER RAINFALL (AREAS HAVE RECEIVED 2-4 INCHES WITH HIGHER AMOUNTS UP TO 7" JUST INLAND OF BOCA RATON OVER THE PAST 24-36 HRS). MODEL SOUNDINGS SUPPORT THE ACTIVITY TAPERING OFF OVER THE FAR SOUTHEASTERN AREAS OR TOWARD MIAMI THROUGH THE MORNING AND AFTERNOON HOURS WITH MAINLY SATURATED PROFILES ABOVE A SLIGHTLY DRIER LAYER FROM THE SURFACE TO 700MB. AS A RESULT...MAXIMUM TEMPERATURES HAVE BEEN SLIGHTLY UNDERCUT BY A FEW DEGREES COMPARED TO GUIDANCE...MAINLY DUE TO PLENTY OF CLOUD COVERAGE ANTICIPATED. IF THIS COVERAGE BEGINS TO BREAK THROUGH THE DAY...TEMPERATURES WILL NEED TO BE ADJUSTED ACCORDINGLY. THE MOIST TREND WITH SOUTHEAST FLOW WILL PERSIST THROUGH SUNDAY BEFORE SOME DRIER AIR MOVES IN FROM THE WEST AND THE RIDGE BUILDS BACK ACROSS THE REGION INTO THE UPCOMING WEEK. /85 LONG TERM (TUESDAY-FRIDAY)... THE LATEST EXTENDED GUIDANCE REMAINS IN DECENT AGREEMENT ON THE LARGE SCALE AND GENERALLY INDICATES FALLING UPPER HEIGHTS IN RESPONSE TO A DEEPENING UPPER TROUGH ACROSS THE REGION. A FRONTAL BOUNDARY IS PROJECTED TO SHIFT SOUTHWARD AND STALL NORTH OF THE AREA THROUGH THE SECOND HALF OF THE WEEK. THE ECMWF SEEMS TO BE THE MORE BULLISH SOLUTION AND SHOWS THE MOISTURE AXIS ASSOCIATED WITH THIS BOUNDARY PROGRESSING FARTHER SOUTH THAN THE GFS/GFS ENSEMBLE MEAN WITH SSW LOW-LEVEL FLOW SETTING UP OVER THE AREA BY THURSDAY. THE COMBINATION OF THE FRONT AND FALLING UPPER HEIGHTS ALONG WITH SSW LOW-LEVEL FLOW WOULD FAVOR MUCH OF THE RAINFALL SETTING UP OVER THE EAST COAST/METRO AREAS BY THURSDAY. /85 AVIATION... A LARGE AREA OF SHOWERS AND THUNDERSTORMS OVER THE ATLANTIC WATERS WERE DEVELOPING ON THE NORTHEAST SIDE OF THE MID/UPPER LEVEL VORTICITY MOVING WEST ACROSS THE FLORIDA STRAITS. THESE SHOWERS/STORMS WERE MOVING QUICKLY TO THE NORTHWEST TOWARDS THE BROWARD AND MIAMI-DADE TAF SITES...AND THEY MAY MOVE OVER THE TAF SITES THROUGH THE EARLY MORNING HOURS. BRIEF MVFR/IFR CONDITIONS AND GUSTY WINDS UP TO 30 KNOTS ARE POSSIBLE. THE AREA OF LOW PRESSURE OVER THE SOUTHEAST GULF AND THE UPPER LEVEL LOW WILL CONTINUE TO MOVE WEST TODAY AND HAVE LESS OF AN INFLUENCE OVER THE REGION THROUGHOUT THE DAY. THIS COMBINED WITH THE OVERNIGHT CONVECTION MAY LIMIT SHOWER/STORM DEVELOPMENT FOR THE EAST COAST METRO AREAS DURING THE DAY. HOWEVER...DEEP MOISTURE IN THE SOUTHEAST LOW LEVEL FLOW WILL CONTINUE...SO KEPT VCTS IN FOR THE TAF SITES. AT KAPF...SHOWER AND STORM DEVELOPMENT IS FORECAST TO BECOME MORE LIKELY AS THE DAY PROGRESSES...AS THE INFLUENCE OF THE UPPER LOW INCREASES. LIGHT WINDS WILL CONTINUE THROUGH THE OVERNIGHT HOURS OUTSIDE OF SHOWERS AND STORMS...AND THEN BECOME SOUTHEAST AROUND 10 KNOTS DURING THE DAY. /84 MARINE... AN UPPER LOW WILL KEEP THE RAIN CHANCES IN THE FORECAST ACROSS THE MARINE AREAS THROUGH THE REMAINDER OF THE WEEKEND WITH LIGHT TO MODERATE SOUTHEAST WINDS CONTINUING. WINDS AND SEAS WILL BE LOCALLY HIGHER IN AND AROUND HEAVIER SHOWERS AND STORMS. HIGH PRESSURE WILL BUILD BACK ACROSS THE REGION THROUGH THE FIRST HALF OF THE UPCOMING WEEK WITH SOUTHEAST WINDS CONTINUING. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 87 76 87 76 / 40 30 50 30 FORT LAUDERDALE 84 77 87 79 / 50 40 60 20 MIAMI 85 77 87 78 / 50 40 60 20 NAPLES 87 75 89 76 / 70 30 60 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...85/AG LONG TERM....85/AG AVIATION...84/AK
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1039 AM CDT SAT SEP 13 2014 .UPDATE...DECREASED HOURLY TEMPERATURES AND OVERALL HIGHS FOR TODAY WITH EXPECTED CLOUD COVER AND LOW-LEVEL COLD AIR ADVECTION TO PERSIST. HAVE ALSO REMOVED THUNDER WORDING FOR SE AREAS WHERE FRONT HAS PASSED THROUGH ALREADY. .DISCUSSION...LOW STRATUS CLOUDS AND POCKETS OF LIGHT DRIZZLE BLANKET THE ENTIRE REGION AS LOW-LVL COLD AIR ADVECTION OCCURS IN LOWEST 150MB WITH NORTH SURFACE WINDS AT 10-15 MPH. THIS IS LEADING TO SOME OF THE COOLEST READINGS OF THE LATE SUMMER SEASON WITH TEMPERATURES STILL IN THE LOW 60S NORTH TO UPPER 60S CENTRAL AND LOW 70S SOUTH. WITH LOW STRATUS TRAPPED UNDERNEATH INVERSION PER OBSERVED AND BUFR SOUNDINGS, FEEL CLOUD COVER WILL PERSIST AT GOOD WHILE INTO THE EARLY TO MID AFTERNOON AND THUS KEEP TEMPERATURES AND INSTABILITY LOW. EVENTUAL MIXING SHOULD HELP SLOW EROSION OF CLOUDS IN SE BUT IT MAY BE TOO LITTLE TO LATE FOR INSTABILITY TO BUILD FOR ANY THUNDERSTORM POTENTIAL. SSEO AND LATEST RUC ANALYSIS DEPICT BETTER TSTORM ENVIRONMENT WILL BE DISPLACED FARTHER SOUTH AND EAST OF PINE BELT. CLOUDS WILL SLOWLY ERODE FROM THE NORTH AS WELL BUT I-20 CORRIDOR MAY BE IN CENTRAL POINT WHERE IT PERSISTS THE LONGEST. HAVE FOLLOWED CLOSE TO GFS LAMP TRENDS THROUGH THE DAY AS IT SEEMS TO BE CAPTURING THE CAA WELL. AN UPDATED AVIATION DISCUSSION CAN BE FOUND BELOW. /ALLEN/ && .AVIATION...MORNING IFR CIGS WL GRADUALLY RISE TO MVFR CIGS THIS AFTN AS AN ABUNDANCE OF COLD ADVECTION STRATUS WILL IMPACT TAF SITES TODAY AND PERHAPS INTO TONIGHT. LINGERING RAIN CHANCES WILL BE MOSTLY CONFINED IN THE HBG/PIB TO MEI AREA...BUT BY THIS EVENING EXPECT MOST OF THE AREA TO BE RAIN-FREE. LOW LEVEL MIXING SHOULD BE STRONG ENOUGH LATE TONIGHT AND EARLY SUNDAY MORNING TO LIMIT ANY FOG POTENTIAL. /EC/22/ && .PREV DISCUSSION... /ISSUED 426 AM CDT SAT SEP 13 2014/ DISCUSSION... TODAY THROUGH SUNDAY NIGHT... STRONG SURFACE HIGH PRESSURE (1031 MB) CENTERED OVER THE PLAINS AND MIDWEST IS RESPONSIBLE FOR TODAY`S SHALLOW COOL AIR INTRUSION BENEATH THE THE SUBTROPICAL RIDGE (591 DM). THE COLD ADVECTION IS LEADING TO A CONSIDERABLE AMOUNT OF STRATUS AND EXPECT THIS TO CONTINUE FOR MOST OF THE DAY RESULTING IN RATHER COOL AFTERNOON TEMPERATURES THAT WILL STRUGGLE TO REACH THE LOWER 70S IN THE UPPER DELTA REGION. THE EXCEPTION TO THIS WILL BE IN THE HATTIESBURG AREA WHERE WEAKER COLD ADVECTION AND LESS LOW CLOUD COVER SHOULD ALLOW TEMPERATURE TO REACH THE LOW TO MID 80S. AS WE GO FROM TONIGHT INTO SUNDAY...THE AIRMASS WILL BEGIN TO MODIFY AND ALLOW FOR SLIGHTLY WARMER TEMPERATURES. MODELS AGREE THAT DEEPER MOISTURE WILL BEGIN TO RETURN...ESPECIALLY BY SUNDAY AFTERNOON AND EVENING ALONG THE I-59 CORRIDOR FROM HBG TO MEI. /EC/ MONDAY THROUGH NEXT SATURDAY... PRETTY GOOD AGREEMENT REMAINS BETWEEN THE GFS AND ECMWF THIS MORNING IN REGARDS TO THE WEATHER ACROSS THE FORECAST AREA THROUGH MUCH OF THE LONG TERM PERIOD. DECENT RAIN CHANCES LOOK TO REMAIN IN THE FORECAST MONDAY THROUGH WEDNESDAY IN THE VICINITY OF A SLOW TO WASH OUT BOUNDARY MEANDERING ABOUT AND AFFECTING MAINLY THE SOUTHERN HALF OF THE ARKLAMISS. MOST OF THIS ACTIVITY LOOKS TO MAINLY BE CONFINED TO THE AFTERNOON AND EARLY EVENING HOURS...BUT SOME COULD LINGER INTO THE OVERNIGHT HOURS. BIGGEST CONCERN DURING THIS TIME WILL BE THE POTENTIAL FOR HEAVY RAINFALL...AGAIN PRIMARILY IN THE SOUTH...AS PRECIPITABLE H2O VALUES REMAIN AROUND THE 2.00 INCH RANGE. RAIN CHANCES LOOK TO DECREASE THURSDAY THROUGH SATURDAY AS A DECENT SURGE OF DRIER AIR FILTERS SOUTH AND DEEPER INTO THE CWA AS HIGH PRESSURE BUILDS INTO THE REGION FROM THE NORTH. IF THIS INDEED UNFOLDS...IT SHOULD BRING A NOTICEABLY DRIER FEEL TO THE AIR...ALONG WITH SOME SLIGHTLY COOLER DAYTIME AND OVERNIGHT TEMPERATURES THROUGH AT LEAST SATURDAY. UNTIL THEN...LOOK FOR A CONTINUATION OF HUMID CONDITIONS MONDAY THROUGH WEDNESDAY AS HIGHS CLIMB TO NEAR 90 AND LOWS GENERALLY RANGE FROM THE MID 60S TO AROUND 70. OBVIOUSLY MONDAY THROUGH WEDNESDAY...AFTERNOON CONVECTION AND ASSOCIATED CLOUD COVER WILL PLAY A LARGE ROLL IN HOW WARM MOST LOCATIONS GET... ESPECIALLY ALONG AND SOUTH OF THE INTERSTATE 20 CORRIDOR. /19/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 77 64 85 68 / 21 11 14 12 MERIDIAN 80 64 87 67 / 25 14 21 16 VICKSBURG 76 61 84 66 / 21 13 11 9 HATTIESBURG 86 68 91 71 / 37 14 27 21 NATCHEZ 76 63 85 68 / 29 14 18 13 GREENVILLE 72 58 82 63 / 20 11 9 9 GREENWOOD 73 58 83 62 / 20 10 10 10 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ ALLEN/22/EC/19
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
609 AM EDT SAT SEP 13 2014 .SYNOPSIS... A FLOOD WATCH HAS BEEN ISSUED FOR SATURDAY AS A STALLED COLD FRONT CONTINUES UNSETTLED WEATHER ACROSS THE AREA. THIS FRONT WILL REMAIN IN THE VICINITY ON SUNDAY...BEFORE LIFTING BACK NORTH ON MONDAY...BUT UNSETTLED WEATHER WILL PERSIST. A STRONGER COLD FRONT WILL CROSS THE AREA ON TUESDAY...BRINGING COOLER AND DRIER WEATHER FOR THE LATTER HALF OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 600 AM SATURDAY...A FLOOD WATCH HAS BEEN POSTED FOR THE ENTIRE ILM CWA...AND IS IN EFFECT FROM 6 AM THIS MORNING THROUGH 6 AM SUNDAY MORNING. A STALLED FRONTAL BOUNDARY LYING EAST-WEST NEARLY ALONG THE NC-SC BORDER WILL LIKELY MEANDER BOTH NORTH AND SOUTH THROUGHOUT THE NEAR TERM PERIOD. INITIALLY...IT MAY TEMPORARILY PUSH NORTHWARD DUE TO A VIGOROUS UPPER S/W TROF PUSHING FROM THE GREAT LAKES TO THE NE STATES TODAY. THEN SETTLING BACK TO THE SOUTH TONIGHT...WITH MODELS HINTING THAT IT MAY DROP SOUTH OF THE ILM CWA DURING SUNDAY. PLENTY OF MOISTURE ON EITHER SIDE OF THE FRONTAL BOUNDARY WITH PWS 2+ INCHES. TO AID PCPN DEVELOPMENT... FORCING IE. UVVS...WILL BE PROVIDED BY THE SFC FRONT ITSELF...AND UPPER DYNAMICS IN THE FORM OF A S/W TROF OR VORT...WHICH WILL FURTHER PROVIDE ADDITIONAL LIFT. NORTH OF THE FRONT WILL OBSERVE OVERRUNNING TYPE PCPN...IE. STRATIFORM RAINS. HOWEVER...ELEVATED CONVECTION REMAINS A GOOD POSSIBILITY DUE TO ELEVATED INSTABILITY...IE. ELEVATED CAPE. SOUTH OF THE FRONT...THE CHARACTER OF THE PCPN WILL BE MORE CONVECTIVE. WITH THE FA LOCATED DIRECTLY ON EITHER SIDE OF THIS FRONT...THE CWA WILL THEN BE SUBJECTED TO PCPN THAT WILL MOVE ACROSS ALREADY SATURATED GROUNDS...OVER AND OVER AGAIN IE. TRAINING...WITH THE END RESULT LIKELY FLOODING. THUS...A 24 HR FLOOD WATCH HAS BEEN ISSUED FOR THE ENTIRE ILM CWA...IN EFFECT FROM 6AM SAT THRU 6AM SUN. VARIOUS MODEL MOS GUIDANCE INDICATE WIDESPREAD 80S FOR MAX TEMPS TODAY. DEPENDING ON WHICH SIDE OF THE FRONT ONE IS...THE RANGE WILL RUN FROM THE LOW 80S NORTHERN PORTIONS OF THE ILM CWA TO MID- UPPER 80S SOUTHERN PORTIONS OR SOUTH OF THE FRONT. THE WIDESPREAD CLOUDS AND PCPN MAY FURTHER PREVENT TEMPS FROM CLIMBING...ESPECIALLY NORTH OF THE FRONT WHERE UPPER 70S IS NOT OUT OF THE QUESTION. THE COOLER AND DRIER AIR BEHIND THE FRONT REMAINS WELL UPSTREAM...FROM VIRGINIA AND NORTHWARD. THUS...EVEN IF TEMPORARY FROPA DOES OCCUR...THE COOLER AND DRIER AIRMASS WILL REMAIN WELL UPSTREAM AND UNABLE TO INFILTRATE THE REGION DURING THIS PERIOD. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 300 AM SATURDAY...AN EXPANDING TROUGH AND A PERSISTENT RIDGE WILL ENGAGE IN BATTLE OVERHEAD THROUGH EARLY NEXT WEEK FOR POSITION OVER THE CAROLINAS. ALMOST LIKE THE OLD CHILDHOOD GAME OF "RED ROVER"...EACH FEATURE WILL TRY TO BREAK THROUGH THE OTHER...BUT THE RIDGE WILL CALL THE TROUGH OVER ONE TOO MANY TIMES...EARNING THE TROUGH A VICTORY...DISPLACING THE RIDGE BY MONDAY NIGHT. THIS FORCES THE COLD FRONT BELOW TO BECOME NEARLY STATIONARY SUNDAY AND MONDAY...WAVERING BACK AND FORTH ACROSS THE AREA...CONTINUING THE UNSETTLED WEATHER PATTERN. SURFACE FRONT WILL BE ALONG THE SOUTHERN TIER...OR JUST SOUTH...OF THE CWA DURING SUNDAY BEFORE SLOWLY LIFTING NORTH AGAIN ON MONDAY. WHILE INSTABILITY WILL BE LIMITED DUE TO WIDESPREAD CLOUD COVER...AND UPPER SUPPORT WILL REMAIN MINIMAL...PERSISTENT MOIST FLOW ATOP THE FRONT COMBINED WITH SURFACE CONVERGENCE ALONG IT (AND RESIDUAL BOUNDARIES) IN A VERY MOIST COLUMN WILL PRODUCE PERIODS OF RAIN/TSTMS SUNDAY AND MONDAY. BEST PRECIP CHANCES MAY BE IN THE SOUTHERN AND WESTERN ZONES SUNDAY AND THIS IS WHERE THE HIGHEST QPF IS EXPECTED...BUT ALL AREAS WILL LIKELY SEE SHOWERS AND STORMS. A BRIEF RESPITE IN CONVECTIVE COVERAGE WILL OCCUR WITH LOSS OF HEATING SUNDAY NIGHT...BEFORE MORE SCATTERED CONVECTION DEVELOPS MONDAY AS THE FRONT LIFTS TO THE NORTH PRODUCING A BRIEF PERIOD OF WAA AND SUMMER-LIKE CONVECTION. THIS WILL BE SHORT LIVED HOWEVER...AS THIS FRONT WILL RETURN BACK TO THE SOUTHEAST AS A COLD FRONT BENEATH A STRONG VORTICITY IMPULSE MOVING TO THE NORTH EITHER VERY LATE MONDAY NIGHT...OR JUST BEYOND THIS PERIOD. ANOTHER ROUND OF HEAVIER PRECIP MAY ACCOMPANY THIS FRONT LATE MONDAY HOWEVER...AND CANNOT AT ANY TIME FORECAST POP BELOW CHC THROUGH THE PERIOD...WITH HIGHEST OCCURRING SUNDAY AND THEN AGAIN LATE MONDAY. HIGHS SUNDAY WILL BE SEVERAL DEGREES BELOW NORMAL THANKS TO CLOUDS...RAIN...AND COOL NORTHERLY SURFACE FLOW...WITH MAX TEMPS EXPECTED TO REACH ONLY THE MID 70S FAR NW...TO MID 80S NEAR THE SOUTH SANTEE RIVER. THE AFOREMENTIONED WAA WILL DRIVE HIGHS INTO THE LOW/MID 80S CWA-WIDE ON MONDAY. LOWS SUNDAY NIGHT WILL DROP TO NEAR-NORMAL LEVELS OF THE MID 60S...BUT WILL BE SEVERAL DEGREES WARMER MONDAY NIGHT AHEAD OF THE NEXT COLD FRONT. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 300 SATURDAY...STRONG COLD FRONT WILL PUSH ACROSS THE AREA ON TUESDAY...USHERING IN COOL CANADIAN AIR FOR MOST OF THE UPCOMING WEEK. STRONG VORTICITY IMPULSE SPAWNING A SURFACE LOW PRESSURE WILL BE RACING EAST WELL NORTH OF THE AREA...BUT A STRONG COLD FRONT BEHIND THIS WILL DRAG ACROSS THE CWA DURING TUESDAY. A PERIOD OF UNSETTLED WEATHER IS EXPECTED TUESDAY WITH SHOWERS AND THUNDERSTORMS...BUT THIS FRONT SHOULD PUSH OFFSHORE BY WEDNESDAY AS A DEEP UPPER TROUGH DIVES INTO THE EAST. THEREAFTER...GUIDANCE CONTINUES TO DIFFER ON HOW FAR OFFSHORE THIS FRONT WILL STALL...WITH THE GFS CONTINUING TO INDICATE THAT IT WILL BE JUST OFFSHORE AND CONTINUE UNSETTLED CONDITIONS LOCALLY. THE ECMWF...WHICH IS PREFERRED...PUSHES THIS FRONT WELL OFF THE COAST...WHICH SEEMS ACCURATE BASED OFF THE STRENGTH OF THE UPPER TROUGH AND SINCE WE HAVE HAD SEVERAL FROPAS ALREADY THIS YEAR. USING THE ECMWF AS A GUIDE...WED-FRI WILL FEATURE DRYING CONDITIONS AND TEMPS AROUND 5 DEGREES BELOW CLIMO THANKS TO THE CANADIAN ORIGIN OF THE SURFACE HIGH RIDGING DOWN THE COAST. IN ADDITION...IT APPEARS THE AREA WILL SEE SUNSHINE FOR THE FIRST TIME IN SEVERAL DAYS BY WEDNESDAY. HOWEVER...MUST NOTE THE PERSISTENCE OF THE GFS WHICH KEEPS THE FRONT JUST OFF THE COAST AND DEVELOPS A LOW PRESSURE SYSTEM ALONG THE TAIL END OF THE BOUNDARY. THIS WOULD KEEP UNSETTLED CONDITIONS ACROSS THE AREA...ESPECIALLY NEAR THE COAST...WITH MORE WET WEATHER POSSIBLE LATE IN THE WEEK. WILL KEEP INHERITED LOW-CHC/SCHC POP FOR POTENTIAL...BUT WITH A SLIGHT DECREASE IN SPECIFIC VALUES TO ACCOUNT FOR THE MUCH DRIER ECMWF. && .AVIATION /10Z SATURDAY THROUGH WEDNESDAY/... AS OF 06Z...STRATIFORM LIGHT RAIN NEAR KILM SHOULD DISSIPATE OVER THE NEXT SEVERAL HOURS...ALTHOUGH THE HRRR MODEL SUGGESTS ISOLATED CONVECTIVE SHOWERS WILL RE-DEVELOP EARLY THIS MORNING ACROSS THE AREA. EXPECT THICK MID/UPPER CLOUD COVER THROUGH THE TAF VALID PERIOD WITH COPIOUS AMOUNTS OF LOW LEVEL MOISTURE. IFR/LIFR CONDITIONS WILL DEVELOP THIS MORNING KLBT/KILM/FLO WITH HIGHEST CONFIDENCE AT KLBT/KILM WHICH IS NEAREST A STATIONARY FRONT. KCRE/KMYR ARE MORE LIKELY TO EXPERIENCE MVFR CONDITIONS THIS MORNING. ANY IFR IMPROVES TO MVFR FAIRLY QUICKLY AFTER SUNRISE WITH VFR DEVELOPING MID-LATE MORNING. CLOUD COVER SHOULD INITIALLY INHIBIT HEATING AND LIFT SO THINK WORSE CASE VCSH COASTAL TERMINALS IN THE MORNING HOURS. BY AFTERNOON THUNDERSTORM POTENTIAL SHOULD BE GREATEST AT KLBT. THIS POTENTIAL SHOULD SHIFT SE-E TO KFLO AND THE THE COASTAL TERMINALS IN THE LATE AFTERNOON/EARLY EVENING. EXTENDED OUTLOOK...A CHANCE OF SHOWERS WITH MAINLY AFTERNOON THUNDERSTORMS/TEMPO MVFR THROUGH TUESDAY. && .MARINE... NEAR TERM/THROUGH TONIGHT/... AS OF 600 AM SATURDAY...WINDS AND TO A LESSER DEGREE SIGNIFICANT SEAS...WILL BE GOVERNED BY THE MEANDERING FRONTAL BOUNDARY DURING THIS PERIOD. THIS MEANS...WATERS NORTH OF THE FRONT WILL OBSERVE NE-E WINDS...AND SOUTH OF THE FRONT WILL SEE SE-SSW WINDS. THE SFC PG REMAINS LOOSE FOR THE MOST PART RESULTING WITH WIND SPEEDS AROUND 10 KT. HOWEVER...DEPENDING ON YOUR LOCATION BEHIND THE FRONT...THE NE-E WINDS THAT OCCUR COULD PRODUCE SPEEDS UP TO 15 KT IF THE SFC PG TIGHTENS ENOUGH. SIGNIFICANT SEAS WILL REMAIN DOCILE...AROUND 2 FT. THE MINI NE-E INCREASED WINDS BEHIND THE FRONT COULD PRODUCE SIG. SEAS UP TO 3 FT. AVERAGE PERIODS WILL RUN 4 TO 5 SECONDS. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 300 AM SATURDAY...COLD FRONT SOUTH OF THE WATERS TO START THE PERIOD WILL REMAIN NEARLY STATIONARY SUNDAY...BEFORE LIFTING BACK TO THE NORTH AS A WARM FRONT MONDAY. THIS DRIVES NE WINDS ALL SUNDAY AND INTO MONDAY...BEFORE VEERING TO BECOME S/SE LATE ON MONDAY. SPEEDS WILL BE 5-10 KTS REGARDLESS OF DIRECTION. A COLD FRONT WILL APPROACH AT THE VERY END OF THE SHORT TERM WITH WINDS BEGINNING TO VEER TO THE WEST LATE MONDAY NIGHT. SEAS WILL BE 1-3 FT THROUGH THE PERIOD...WITH A NE WIND WAVE PREDOMINANT ON SUNDAY...BECOMING SOUTHERLY DURING MONDAY. LONG TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 300 AM SATURDAY...THE BEGINNING OF AN EXTENDED PERIOD OF POOR MARINE CONDITIONS EXPECTED TUESDAY AS A COLD FRONT CROSSES THE WATERS. ALTHOUGH WINDS TUESDAY WILL BE PRETTY LIGHT...5-10 KTS WITH SEVERAL VEERING WIND DIRECTIONS...THE CONFUSED SPECTRUM WILL COMBINE WITH THE SLOWLY AMPLIFYING LONG PERIOD 13-14 SEC SE SWELL ASSOCIATED WITH TROPICAL STORM EDOUARD MOVING THROUGH THE CENTRAL ATLANTIC...TO DRIVE INCREASING WAVE HEIGHTS. ADDITIONALLY...A NE SURGE WILL BEGIN TUESDAY NIGHT BEHIND THIS BOUNDARY...WITH NE WINDS RISING TO AROUND 15 KTS ON WEDNESDAY. THE COMBINATION OF THE LONG-PERIOD SWELL AND INCREASING WINDS WILL DRIVE WAVE HEIGHTS FROM 2-4 FT TUESDAY TO 4-6 FT WEDNESDAY...AND A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED BEGINNING WEDNESDAY. ALTHOUGH IT IS BEYOND THIS PERIOD...IT APPEARS WEDNESDAY COULD BE THE FIRST OF SEVERAL CONSECUTIVE DAYS WITH HEADLINES NEEDED ACROSS THE COASTAL WATERS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...FLOOD WATCH THROUGH LATE TONIGHT FOR SCZ017-023-024-032-033- 039-053>056. NC...FLOOD WATCH THROUGH LATE TONIGHT FOR NCZ087-096-099-105>110. MARINE...NONE. && $$ SYNOPSIS...JDW NEAR TERM...DCH SHORT TERM...JDW LONG TERM...JDW AVIATION...DCH/MRR MARINE...
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1021 AM CDT SAT SEP 13 2014 .UPDATE... ISSUED AT 1017 AM CDT SAT SEP 13 2014 FCST GOING AS PLANNED...HIGH AND MID LEVEL CLOUDS OVER THE FCST AREA IN AREA OF 850 MB WARM ADVECTION. 925 MB WINDS IN THE 25-30 KT RANGE 15-21Z WILL START TO GET TO THE SURFACE AS TEMPS WARM. MAIN SFC LOW WEST OF BRANDON MANITOBA...MOVING EAST. RAIN SHOWERS MOSTLY ASSOC WITH UPPER LOW JUST NORTH OF REGINA SK AND MODELS CONTINUE TO KEEP MOST OF THE PRECIP WITH THIS EVENT JUST NORTH OF THE BORDER TONIGHT THEN OVER LAKE OF THE WOODS REGION AND ONTARIO SUNDAY. WILL CONTINUE WITH LOWER POPS SOUTH OF LOW WITH HRRR SHOWING SOME SHOWERS LATER AFTN-EVE MOVING INTO NE ND/NRN RRV. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 338 AM CDT SAT SEP 13 2014 NO CHANGE IN THE CURRENT FROST ADVISORY...ALTHOUGH A FEW LOCATIONS OVER THE FAR EASTERN CWFA ARE IN THE MID 20S AT 08Z. WITH CIRRUS INCREASING AND RETURN FLOW DEVELOPING DO NOT EXPECT TEMPERATURES TO FALL MORE THAN 1 OR 2 DEGREES IN THE KVWU...KBJI...KBDO AND KADC AREAS. TODAY WILL BE A TRANSITION DAY. AS THE UNSEASONALLY COLD HIGH MOVES SOUTH...LOW PRESSURE INTENSIFIES OVER SASKATCHEWAN SOUTH WINDS WILL INCREASE BY MID DAY. THE MODELS INITIALIZED WELL AND WILL FOLLOW THE HIGHER RESOLUTION HRRR AND NAM12 TODAY...BLENDING THE NAM/GFS FOR TONIGHT INTO SUNDAY MORNING. TIMING OF WARM ADVECTION PRECIPITATION AHEAD OF WELL DEFINED UPPER WAVE OVER FAR NORTH-CENTRAL MONTANA SIMILAR TO PREVIOUS FORECAST REACHING THE DEVILS LAKE BASIN AROUND 18Z AND SPREADING EAST. NAM/GFS HAVE SMALL AREA OF 0C SHOWALTERS AND SOME ML CAPE BUT WILL NOT MENTION TSRA ATTM. WITH WELL MIXED LAYER TO AROUND 800 MB...35 KTS AT 850 IN THE NAM AND NEAR 30 KTS IN THE GFS TRANSLATE TO GUSTS CLOSE TO 30 KTS POSSIBLE. MOS HAS 27 KTS AND WILL FOLLOW THAT FOR THE 18Z - 00Z PERIOD. SECOND STRONGER SHORTWAVE...DROPPING ALONG THE ALBERTA/SASKATCHEWAN BORDER IS FORECAST TO BE NEAR KDVL AT 06Z TONIGHT. SURFACE LOW SLOWS AND WRAP AROUND SHRA SPREADING OVER THE EAST HALF OF THE CWFA INTO SUNDAY MORNING. THE COLUMN COOLS AND DRIES MOST AREAS SUNDAY...WITH LINGERING SHRA OVER THE NORTHEAST PORTION OF THE CWFA...WITH STRONGER MID-UPPER CAA ALONG SHEAR AXIS AND ENTRANCE REGION OF UPPER JET. THIS QUICKLY MOVES OUT WITH PRECIPITATION ENDING BY 00Z MONDAY. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 338 AM CDT SAT SEP 13 2014 WINDS DIMINISH AND SKIES CLEAR AS HIGH PRESSURE MOVES ACROSS THE CWFA. LOWS WILL FALL BACK INTO THE LOW TO MID 30S...BUT EXPECT SUFFICIENT MIXING AT THIS TIME TO KEEP FROST/FREEZE RISK MINIMAL FOR MONDAY MORNING. LIGHT SOUTHWEST WINDS AND PLENTIFUL SUNSHINE WILL ALLOW MODEST WARM-UP MONDAY TO NEAR MID SEPTEMBER NORMALS. RISING HEIGHTS AND CONTINUED WESTERLY FLOW WILL MAKE FOR A MAINLY CLEAR AND MILD MONDAY NIGHT. TUESDAY TO FRIDAY...CONFLUENT NW FLOW ALOFT FOR MUCH OF THE WEEK WITH A QUICK TRANSITIONING PERIOD THURSDAY INTO FRIDAY. AS A RESULT DRY CONDITIONS EXPECTED WITH MODERATING TEMPS AS THICKNESSES INCREASE WITH RIDGING OVER THE FA BY THURSDAY. BY THURSDAY PM OR FRIDAY DEPENDING ON MODEL OF CHOICE...500MB SW FLOW AND 850MB LLJ BRING INSTABILITY INTO FA FROM WEST TO EAST. WENT WITH A MOSTLY SHRA AND ISO THUNDER FOR WX GRIDS AS SHOWALTERS DO BECOME NEGATIVE AHEAD OF THE SFC TROUGH EXPECTED TO IMPACT THE NORTHERN PLAINS TOWARDS THE END OF THE WEEK. TEMPERATURES ABOVE NORMAL THROUGH THE WEEK CAN BE EXPECTED WITH SOME HUMIDITY POSSIBLE BY WEEKS END. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 1133 AM CDT SAT SEP 13 2014 VFR CIG/VSBY THROUGH THIS PERIOD...WITH INCRG SOUTH WINDS. BY 16Z EXPECT G25KTS MOST TAF SITES. WSHFT FCST AT KDVL ABT 22Z. WDLY SCT -SHRA PSBL AFT 18Z...BUT INSUFFICIENT CONFIDENCE TO PUT IN TAF ATTM. -SHRA MOST LIKELY KDVL...KGFK...KTVF LINE AFT 21Z. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...RIDDLE SHORT TERM...EWENS LONG TERM...JK/EWENS AVIATION...EWENS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
854 AM CDT SAT SEP 13 2014 .UPDATE... ISSUED AT 845 AM CDT SAT SEP 13 2014 CANCELLED THE FROST ADVISORY. REFINED THE CLOUD COVER BASED ON SATELLITE TRENDS AS HIGH CLOUDS ARE FADING A BIT CENTRAL. UPPED THE WINDS A BIT AFTER THE FRONTAL PASSAGE. UPDATE ISSUED AT 633 AM CDT SAT SEP 13 2014 LATEST SURFACE ANALYSIS SHOWS SURFACE CDFNT OVER WESTERN NORTH DAKOTA WITH STRATOCU DECK DROPPING SOUTH FROM ALBERTA AND WESTERN SASKATCHEWAN INTO NORTH CENTRAL MONTANA. LATEST 10 UTC RAP LOOKS TO BE A LITTLE TOO QUICK IN BRINGING HIGHER 850 MB MOISTURE INTO WESTERN NORTH DAKOTA...BUT BASED ON LATEST SATELLITE AND OBSERVATIONS HAVE BUMPED UP SKY COVER ACROSS THE WEST LATER THIS MORNING AND OVER THE NORTH AND CENTRAL THIS AFTERNOON. NO CHANGES TO POPS AT THIS TIME...KEEPING SLIGHT CHANCE MAINLY NORTH OF THE I94 CORRIDOR...WHICH IS IN AGREEMENT WITH LATEST RAP/HRRR ITERATIONS. CURRENT TEMPERATURES REMAIN IN THE MID 30S ACROSS MOST OF THE FROST ADVISORY AREA...THUS WILL KEEP IT GOING. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 308 AM CDT SAT SEP 13 2014 EARLY MORNING WATER VAPOR IMAGERY SHOWED AN UPPER WAVE MOVING SOUTHEAST ACROSS SOUTHERN SASKATCHEWAN WHICH WAS PUSHING A COLD FRONT TOWARDS THE STATE. THE UPPER WAVE IS EXPECTED TO MOVE QUICKLY ACROSS THE NORTHERN PLAINS TODAY ALONG WITH THE COLD FRONT. THE MAIN QUESTION WILL BE HOW FAR SOUTH TO BRING A CHANCE OF RAIN SHOWERS TODAY AS THE WAVE / COLD FRONT PASS. THERE ARE A WIDE VARIETY OF MODEL SOLUTIONS WITH DIFFERING PLACEMENT...BUT DUE TO THE STRENGTH OF THE WAVE OPTED TO FAVOR THE MODELS WHICH BRING THE RAIN CHANCES FARTHER SOUTH INTO NORTH DAKOTA. IN FACT...AM A BIT CONCERNED WE MAY NOT HAVE TAKEN THE POPS FAR ENOUGH SOUTH IF THE 4.0KM WRF NMM VERIFIES. A POTENTIAL LIMITING FACTOR COULD BE DRY AIR IN THE LOW LEVELS...SO KEPT THE RAIN CHANCES GENERALLY NORTH OF I-94. THE NEXT CONCERN SURROUNDS THE FROST ADVISORY WHICH IS IN PLACE ACROSS ROUGHLY THE SOUTHERN HALF OF THE FORECAST AREA THIS MORNING. PASSING HIGH CLOUDS AHEAD OF THE UPPER WAVE HAVE HELPED TEMPERATURES RISE A FEW DEGREES OVERNIGHT IN SOME LOCATIONS...BUT READINGS IN THE ADVISORY AREA REMAIN IN THE 30S TO LOWER 40S. THE HIGH CLOUDS ARE RATHER THIN ON THEIR SOUTHERN EDGE...AND WITH GFS LAMP GUIDANCE STILL SUPPORTING FALLING TEMPERATURES AT MOST LOCATIONS...WILL KEEP THE ADVISORY IN PLACE. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 308 AM CDT SAT SEP 13 2014 THE LONG TERM PERIOD BEGINNING SUNDAY LOOKS RATHER TRANQUIL THROUGH MID WEEK. PATCHY MORNING FROST CAN NOT BE RULED OUT EARLY SUNDAY AND MONDAY MORNINGS WITH SURFACE HIGH PRESSURE OVER THE AREA AND A NORTHWEST UPPER FLOW KEEPING SEASONABLY COOL AIR OVER THE NORTHERN PLAINS. OTHERWISE IT LOOKS DRY WITH A WARMING TREND THROUGH MIDWEEK. MORNING LOWS IN THE MID 30S TO LOWER 40S...AND DAYTIME HIGHS IN THE UPPER 50S AND 60S SUNDAY AND MONDAY...WILL WARM TO THE MID 40S TO MID 50S FOR LOWS...AND 70S FOR HIGHS BY MID TO LATE WEEK. A PROGRESSIVE UPPER LEVEL TROUGH MOVING ONTO THE WESTERN U.S. COAST ON THURSDAY WILL APPROACH THE NORTHERN PLAINS BY LATE FRIDAY. THERE ARE DIFFERENCES IN THE HANDLING OF THIS WAVE BETWEEN THE GFS AND ECMWF MODELS BUT BOTH BRING INCREASING MOISTURE AND A SMALL CHANCE OF SHOWERS AND ISOLATED THUNDER LATE THURSDAY INTO EARLY FRIDAY...WITH THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS FRIDAY AND FRIDAY NIGHT AND POSSIBLY LINGERING IN THE EAST EARLY SATURDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 845 AM CDT SAT SEP 13 2014 COLD FRONT WILL TRACK ACROSS THE STATE TODAY. WIDELY SCATTERED SHOWERS NORTH. VFR EXPECTED TO CONTINUE. CEILINGS AS LOW AS 35 HUNDRED AGL KDIK-KISN-KMOT...5 THOUSAND AGL OR GREATER BIS-KJMS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...WAA SHORT TERM...CK LONG TERM...TWH AVIATION...WAA
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
707 AM CDT SAT SEP 13 2014 .UPDATE... ISSUED AT 705 AM CDT SAT SEP 13 2014 MINIMAL CHANGES THIS UPDATE. TWEAKED WIND GUST TIMING SLIGHTLY BASED ON 88D VWP 925MB WINDS...HRRR AND NAM12 SFC WIND FCST. LATER SHIFTS WILL NEED TO REFINE TIMING OF -SHRA AND AREAL COVERAGE. OTRW FROST ADVISORY EXP 13Z. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 338 AM CDT SAT SEP 13 2014 NO CHANGE IN THE CURRENT FROST ADVISORY...ALTHOUGH A FEW LOCATIONS OVER THE FAR EASTERN CWFA ARE IN THE MID 20S AT 08Z. WITH CIRRUS INCREASING AND RETURN FLOW DEVELOPING DO NOT EXPECT TEMPERATURES TO FALL MORE THAN 1 OR 2 DEGREES IN THE KVWU...KBJI...KBDO AND KADC AREAS. TODAY WILL BE A TRANSITION DAY. AS THE UNSEASONALLY COLD HIGH MOVES SOUTH...LOW PRESSURE INTENSIFIES OVER SASKATCHEWAN SOUTH WINDS WILL INCREASE BY MID DAY. THE MODELS INITIALIZED WELL AND WILL FOLLOW THE HIGHER RESOLUTION HRRR AND NAM12 TODAY...BLENDING THE NAM/GFS FOR TONIGHT INTO SUNDAY MORNING. TIMING OF WARM ADVECTION PRECIPITATION AHEAD OF WELL DEFINED UPPER WAVE OVER FAR NORTH-CENTRAL MONTANA SIMILAR TO PREVIOUS FORECAST REACHING THE DEVILS LAKE BASIN AROUND 18Z AND SPREADING EAST. NAM/GFS HAVE SMALL AREA OF 0C SHOWALTERS AND SOME ML CAPE BUT WILL NOT MENTION TSRA ATTM. WITH WELL MIXED LAYER TO AROUND 800 MB...35 KTS AT 850 IN THE NAM AND NEAR 30 KTS IN THE GFS TRANSLATE TO GUSTS CLOSE TO 30 KTS POSSIBLE. MOS HAS 27 KTS AND WILL FOLLOW THAT FOR THE 18Z - 00Z PERIOD. SECOND STRONGER SHORTWAVE...DROPPING ALONG THE ALBERTA/SASKATCHEWAN BORDER IS FORECAST TO BE NEAR KDVL AT 06Z TONIGHT. SURFACE LOW SLOWS AND WRAP AROUND SHRA SPREADING OVER THE EAST HALF OF THE CWFA INTO SUNDAY MORNING. THE COLUMN COOLS AND DRIES MOST AREAS SUNDAY...WITH LINGERING SHRA OVER THE NORTHEAST PORTION OF THE CWFA...WITH STRONGER MID-UPPER CAA ALONG SHEAR AXIS AND ENTRANCE REGION OF UPPER JET. THIS QUICKLY MOVES OUT WITH PRECIPITATION ENDING BY 00Z MONDAY. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 338 AM CDT SAT SEP 13 2014 WINDS DIMINISH AND SKIES CLEAR AS HIGH PRESSURE MOVES ACROSS THE CWFA. LOWS WILL FALL BACK INTO THE LOW TO MID 30S...BUT EXPECT SUFFICIENT MIXING AT THIS TIME TO KEEP FROST/FREEZE RISK MINIMAL FOR MONDAY MORNING. LIGHT SOUTHWEST WINDS AND PLENTIFUL SUNSHINE WILL ALLOW MODEST WARM-UP MONDAY TO NEAR MID SEPTEMBER NORMALS. RISING HEIGHTS AND CONTINUED WESTERLY FLOW WILL MAKE FOR A MAINLY CLEAR AND MILD MONDAY NIGHT. TUESDAY TO FRIDAY...CONFLUENT NW FLOW ALOFT FOR MUCH OF THE WEEK WITH A QUICK TRANSITIONING PERIOD THURSDAY INTO FRIDAY. AS A RESULT DRY CONDITIONS EXPECTED WITH MODERATING TEMPS AS THICKNESSES INCREASE WITH RIDGING OVER THE FA BY THURSDAY. BY THURSDAY PM OR FRIDAY DEPENDING ON MODEL OF CHOICE...500MB SW FLOW AND 850MB LLJ BRING INSTABILITY INTO FA FROM WEST TO EAST. WENT WITH A MOSTLY SHRA AND ISO THUNDER FOR WX GRIDS AS SHOWALTERS DO BECOME NEGATIVE AHEAD OF THE SFC TROUGH EXPECTED TO IMPACT THE NORTHERN PLAINS TOWARDS THE END OF THE WEEK. TEMPERATURES ABOVE NORMAL THROUGH THE WEEK CAN BE EXPECTED WITH SOME HUMIDITY POSSIBLE BY WEEKS END. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 1133 AM CDT SAT SEP 13 2014 VFR CIG/VSBY THROUGH THIS PERIOD...WITH INCRG SOUTH WINDS. BY 16Z EXPECT G25KTS MOST TAF SITES. WSHFT FCST AT KDVL ABT 22Z. WDLY SCT -SHRA PSBL AFT 18Z...BUT INSUFFICIENT CONFIDENCE TO PUT IN TAF ATTM. -SHRA MOST LIKELY KDVL...KGFK...KTVF LINE AFT 21Z. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...FROST ADVISORY UNTIL 8 AM CDT THIS MORNING FOR NDZ030-039-049- 052-053. MN...FROST ADVISORY UNTIL 8 AM CDT THIS MORNING FOR MNZ001>003-005- 006-008-009-013>017-022>024-027>032-040. && $$ UPDATE...EWENS SHORT TERM...EWENS LONG TERM...JK/EWENS AVIATION...EWENS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
634 AM CDT SAT SEP 13 2014 .UPDATE... ISSUED AT 633 AM CDT SAT SEP 13 2014 LATEST SURFACE ANALYSIS SHOWS SURFACE CDFNT OVER WESTERN NORTH DAKOTA WITH STRATOCU DECK DROPPING SOUTH FROM ALBERTA AND WESTERN SASKATCHEWAN INTO NORTH CENTRAL MONTANA. LATEST 10 UTC RAP LOOKS TO BE A LITTLE TOO QUICK IN BRINGING HIGHER 850 MB MOISTURE INTO WESTERN NORTH DAKOTA...BUT BASED ON LATEST SATELLITE AND OBSERVATIONS HAVE BUMPED UP SKY COVER ACROSS THE WEST LATER THIS MORNING AND OVER THE NORTH AND CENTRAL THIS AFTERNOON. NO CHANGES TO POPS AT THIS TIME...KEEPING SLIGHT CHANCE MAINLY NORTH OF THE I94 CORRIDOR...WHICH IS IN AGREEMENT WITH LATEST RAP/HRRR ITERATIONS. CURRENT TEMPERATURES REMAIN IN THE MID 30S ACROSS MOST OF THE FROST ADVISORY AREA...THUS WILL KEEP IT GOING. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 308 AM CDT SAT SEP 13 2014 EARLY MORNING WATER VAPOR IMAGERY SHOWED AN UPPER WAVE MOVING SOUTHEAST ACROSS SOUTHERN SASKATCHEWAN WHICH WAS PUSHING A COLD FRONT TOWARDS THE STATE. THE UPPER WAVE IS EXPECTED TO MOVE QUICKLY ACROSS THE NORTHERN PLAINS TODAY ALONG WITH THE COLD FRONT. THE MAIN QUESTION WILL BE HOW FAR SOUTH TO BRING A CHANCE OF RAIN SHOWERS TODAY AS THE WAVE / COLD FRONT PASS. THERE ARE A WIDE VARIETY OF MODEL SOLUTIONS WITH DIFFERING PLACEMENT...BUT DUE TO THE STRENGTH OF THE WAVE OPTED TO FAVOR THE MODELS WHICH BRING THE RAIN CHANCES FARTHER SOUTH INTO NORTH DAKOTA. IN FACT...AM A BIT CONCERNED WE MAY NOT HAVE TAKEN THE POPS FAR ENOUGH SOUTH IF THE 4.0KM WRF NMM VERIFIES. A POTENTIAL LIMITING FACTOR COULD BE DRY AIR IN THE LOW LEVELS...SO KEPT THE RAIN CHANCES GENERALLY NORTH OF I-94. THE NEXT CONCERN SURROUNDS THE FROST ADVISORY WHICH IS IN PLACE ACROSS ROUGHLY THE SOUTHERN HALF OF THE FORECAST AREA THIS MORNING. PASSING HIGH CLOUDS AHEAD OF THE UPPER WAVE HAVE HELPED TEMPERATURES RISE A FEW DEGREES OVERNIGHT IN SOME LOCATIONS...BUT READINGS IN THE ADVISORY AREA REMAIN IN THE 30S TO LOWER 40S. THE HIGH CLOUDS ARE RATHER THIN ON THEIR SOUTHERN EDGE...AND WITH GFS LAMP GUIDANCE STILL SUPPORTING FALLING TEMPERATURES AT MOST LOCATIONS...WILL KEEP THE ADVISORY IN PLACE. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 308 AM CDT SAT SEP 13 2014 THE LONG TERM PERIOD BEGINNING SUNDAY LOOKS RATHER TRANQUIL THROUGH MID WEEK. PATCHY MORNING FROST CAN NOT BE RULED OUT EARLY SUNDAY AND MONDAY MORNINGS WITH SURFACE HIGH PRESSURE OVER THE AREA AND A NORTHWEST UPPER FLOW KEEPING SEASONABLY COOL AIR OVER THE NORTHERN PLAINS. OTHERWISE IT LOOKS DRY WITH A WARMING TREND THROUGH MIDWEEK. MORNING LOWS IN THE MID 30S TO LOWER 40S...AND DAYTIME HIGHS IN THE UPPER 50S AND 60S SUNDAY AND MONDAY...WILL WARM TO THE MID 40S TO MID 50S FOR LOWS...AND 70S FOR HIGHS BY MID TO LATE WEEK. A PROGRESSIVE UPPER LEVEL TROUGH MOVING ONTO THE WESTERN U.S. COAST ON THURSDAY WILL APPROACH THE NORTHERN PLAINS BY LATE FRIDAY. THERE ARE DIFFERENCES IN THE HANDLING OF THIS WAVE BETWEEN THE GFS AND ECMWF MODELS BUT BOTH BRING INCREASING MOISTURE AND A SMALL CHANCE OF SHOWERS AND ISOLATED THUNDER LATE THURSDAY INTO EARLY FRIDAY...WITH THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS FRIDAY AND FRIDAY NIGHT AND POSSIBLY LINGERING IN THE EAST EARLY SATURDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 633 AM CDT SAT SEP 13 2014 A COLD FRONT WILL MOVE ACROSS NORTH DAKOTA TODAY. THIS WILL BRING GUSTY WEST / NORTHWEST WINDS WITH INCREASING CLOUDS. HAVE KEPT CEILINGS VFR FOR NOW...BUT COULD SEE THE POTENTIAL FOR MVFR...ESPECIALLY AT KISN AND KMOT. WINDS DIMINISH SATURDAY EVENING AS SURFACE HIGH PRESSURE BUILDS INTO WESTERN NORTH DAKOTA. CLOUDS SHOULD DIMINISH SOUTH AND WEST...BUT THEY MAY LINGER ESPECIALLY TOWARDS KMOT. A FEW RAIN SHOWERS ARE ALSO EXPECTED TODAY...BUT DID NOT PUT THEM INTO THE TAF FOR NOW. && .BIS WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY UNTIL 9 AM CDT /8 AM MDT/ THIS MORNING FOR NDZ020- 025-033>037-040>048-050-051. && $$ UPDATE...TWH SHORT TERM...CK LONG TERM...TWH AVIATION...CK
AREA FORECAST DISCUSSION
NWS NORMAN OK
1037 AM CDT SAT SEP 13 2014 .DISCUSSION... PERSISTENT CLOUD COVER WILL MAINTAIN RELATIVELY COOL WEATHER INTO THE AFTERNOON OVER MOST OF OKLAHOMA AND NORTH TEXAS. CURRENT SATELLITE TRENDS APPEAR TO SUPPORT THE HRRR MODEL FORECAST OF CLOUD BREAKUP THIS AFTERNOON...EARLIER IN PARTS OF NORTHERN OKLAHOMA...WHERE THERE ARE ALREADY LARGE HOLES IN THE CLOUD COVER. THE FORECAST WAS UPDATED EARLIER THIS MORNING TO ACCOUNT FOR THE LATEST TRENDS AND EXPECTATIONS. && .PREV DISCUSSION... /ISSUED 638 AM CDT SAT SEP 13 2014/ AVIATION... 13/12Z TAFS...MVFR CIGS WILL BE SEEN AT MOST TERMINALS THROUGH ABOUT 15-17Z...WITH VFR EXPECTED THEREAFTER. NORTHERLY WINDS WILL BECOME SOUTHEAST LATE TODAY AND INCREASE IN SPEED AFTER THIS FORECAST PERIOD. LOW CLOUDS WILL BEGIN TO INCREASE TOWARD END OF FORECAST PERIOD BUT WILL LEAVE FCST VFR FOR NOW. PREV DISCUSSION... /ISSUED 410 AM CDT SAT SEP 13 2014/ DISCUSSION... CLEARING...AT LEAST PARTIALLY...EXPECTED THE REGION TODAY. THE GREATEST AMOUNT OF CLEARING EXPECTED OVER THE NORTH-CENTRAL PORTIONS OF OKLAHOMA. SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS MAY ACTUALLY SEE MORE CLOUDS THAN SUN TODAY. NO PRECIPITATION EXPECTED TODAY OR TONIGHT. RETURN TO SOUTHERLY FLOW TONIGHT AND SUNDAY WILL ALLOW MOISTURE TO WORK ITS WAY BACK OVER REGION AND ALLOW CLOUDS TO FILL BACK IN ON SUNDAY. RAIN CHANCES RETURN TO FORECAST SUNDAY NIGHT AS NEXT UPPER LEVEL TROUGH AND ASSOCIATED COLD FRONT MOVE OVER SOUTHERN PLAINS. MOST OF THE PRECIP EXPECTED NEAR THE FRONT AS IT PROGRESSES SLOWLY SOUTH OVER OKLAHOMA TO THE RED RIVER VALLEY MONDAY AFTERNOON AND MONDAY NIGHT. FRONT LIFTS BACK NORTH TUESDAY INTO WEDNESDAY...AND WITH DEVELOPMENT OF NWLY FLOW...WILL BE A FOCUS FOR SHOWERS AND STORMS WEDNESDAY INTO THURSDAY MAINLY OVER THE EASTERN HALF OF OKLAHOMA. CONFIDENCE NOT QUITE AS HIGH SO POPS WILL REMAIN ON THE LOW SIDE OF GUIDANCE. FAIR AMOUNT OF DISPARITY IN THE MEDIUM RANGE MODELS FOR FRIDAY AND NEXT WEEKEND...WITH ECM CURRENTLY SHOWING PROLONGED PERIOD OF RAIN AND GFS A MORE PROGRESSIVE AND DRY PATTERN. TRENDS WILL NEED TO BE MONITORED BEFORE POPS ARE INTRODUCED AT END OF FORECAST PERIOD. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 66 57 80 66 / 0 0 10 20 HOBART OK 70 55 80 65 / 0 0 10 20 WICHITA FALLS TX 67 59 81 68 / 10 0 10 10 GAGE OK 71 53 82 63 / 0 0 10 10 PONCA CITY OK 67 53 79 65 / 0 0 10 20 DURANT OK 68 60 78 66 / 10 0 10 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 23/17
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
350 PM MST SAT SEP 13 2014 .SYNOPSIS... AN INCREASE IN MOISTURE FROM THE EAST WILL MAINTAIN A SLIGHT CHANCE THUNDERSTORMS THROUGH MONDAY. DEEPER TROPICAL MOISTURE WILL BEGIN TO MOVE IN TUESDAY FOR A SIGNIFICANT INCREASE IN STORM CHANCES THE REST OF NEXT WEEK. && .DISCUSSION... REST OF TODAY THROUGH MONDAY... TIGHT SURFACE PRESSURE GRADIENT ACROSS ARIZONA AND NEW MEXICO WITH LOWER PRESSURE OVER THE MOHAVE DESERT AND HIGH PRESSURE OVER THE PLAINS. THIS IS DUE TO A BACK DOOR COLD FRONT SPILLING OVER THE SOUTHERN CONTINENTAL DIVIDE. BREEZY EASTERLY WINDS HAVE RESULTED AS HAVE HIGHER DEW POINTS AND COOLER TEMPERATURES...MOST NOTICEABLY OVER EASTERN PORTIONS OF OUR FORECAST AREA. THE INCREASED MOISTURE HOWEVER LOOKS TO BE OFFSET BY AN INCREASE IN CIN...AT LEAST OVER SOUTHERN ARIZONA. NCEP MODELS AS WELL AS HRRR AND LOCAL HI-RES MODELS ARE NOT VERY ENTHUSIASTIC ABOUT STORM ACTIVITY THE REST OF TODAY AND TONIGHT FOR OUR AREA. HOWEVER...WITH THE MOISTURE THERE IS A SLIGHT CHANCE OF OUTFLOW FROM DISTANT STORMS KICKING OFF A STORM...MAINLY EAST OF THE LOWER COLORADO RIVER VALLEY. FOR SUNDAY AND MONDAY...THE MODELS AGREE ON THE IDEA OF A SLOW WARMING OF THE BOUNDARY LAYER TO REDUCE THE CAP BUT NO INCREASE IN MOISTURE...EVEN DECREASING A BIT. SO SLIGHT CHANCES CONTINUE. ONE DIFFERENCE MIGHT BE FOR MONDAY AS AN ANTICYCLONE BECOMES CENTERED OVER SOUTHERN NEVADA LEADING TO NORTHEASTERLY STEERING FLOW...PER GFS...WHICH COULD AID THE ADVECTION OF MOGOLLON RIM STORMS INTO OUR HIGHER TERRAIN ZONE EAST OF PHOENIX. THE PRESSURE GRADIENT CONTINUES SUNDAY FOR MORE BREEZINESS BEFORE WEAKENING MONDAY. MEANWHILE...HURRICANE ODILE CURRENTLY SEVERAL HUNDRED MILES SOUTH-SOUTHEAST OF THE SOUTHERN TIP OF BAJA IS FORECAST TO MOVE NORTHWESTWARD WITH THE EYE GETTING FAIRLY CLOSE TO CABO SAN LUCAS LATE SUNDAY NIGHT/EARLY MONDAY MORNING. TUESDAY THROUGH SATURDAY... MODELS INDICATE SOMETHING OF A GULF SURGE...MOST LIKELY DRIVEN BY HURRICANE ODILE...MOVING INTO OUR FORECAST AREA BY TUESDAY. POPS GO UP A BIT DUE TO INCREASED MOISTURE AND GREATER LIKELIHOOD OF MOUNTAIN STORMS BUT THERE MAY BE SOME BOUNDARY LAYER COOLING WHICH HURTS INSTABILITY OVER THE LOWER ELEVATIONS. 12Z GFS AND ECMWF BEGIN DIVERGING MORE NOTICEABLY IN THEIR POSITIONING OF ODILE AS WELL AS THE ANTICYCLONE TO THE NORTH AND THE NORTHEAST PACIFIC TROUGH. THE ECMWF IS A BIT MORE AMPLIFIED WITH THE FLOW AND HAS THE MID LATITUDE ROSSBY WAVE A BIT FURTHER WEST WITH ODILE CLOSER TO THE BAJA COAST. IT BRINGS REMNANTS OF ODILE INLAND BY FRIDAY. THE 12Z GFS TRACKS ODILE FURTHER WEST. HOWEVER...THE GFS HAS A MORE DISTINCT SHORT WAVE MOVING NORTHWARD INTO ARIZONA WEDNESDAY NIGHT AND THURSDAY BECAUSE IT HAS THE ANTICYCLONE FURTHER EAST. THE NATIONAL HURRICANE CENTER FORECAST IS CLOSER TO THE ECWMF POSITION. A QUICK LOOK AT THE 18Z GFS SHOWS THAT IT NOW LOOKS A LOT MORE LIKE THE ECMWF. IN SHORT...THEY BOTH ARE INDICATING THAT THE BEST CHANCES FOR STORMS AND ASSOCIATED FLOODING POTENTIAL IS IN THE WEDNESDAY THROUGH FRIDAY TIME FRAME. IT SHOULD BE NOTED THAT NEITHER MODEL HAS ESPECIALLY IMPRESSIVE MODEL RUN TOTAL PRECIP ACCUMULATIONS CONSIDERING THE ABUNDANT PRECIPITABLE WATER THAT WILL BE AVAILABLE. LIKEWISE WITH THE WPC FORECASTS. FORECASTS REFLECT POPS THAT ARE SUBSTANTIALLY ABOVE CLIMO ALONG WITH COOLER TEMPS. FAR TOO EARLY FOR FLASH FLOOD WATCHES BUT WILL CONTINUE TO EVALUATE. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...KSDL...AND SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH... SCATTERED TO BROKEN CLOUD DECKS GENERALLY AOA 12KFT...AND WINDS WILL CONTINUE TO FAVOR EAST-SOUTHEASTERLY DIRECTIONS AT ALL TERMINALS THIS EVENING/OVERNIGHT INTO SUNDAY. EXPECT LOCAL GUSTS UP TO 20KT OR SO AT TIMES...MAINLY BETWEEN 15Z AND 20Z SUNDAY. STORM CHANCES ARE SLIGHT FOR THE DESERT ELEVATIONS...MORE FAVORED OVER MOUNTAINS OF NORTHERN/EASTERN AZ DURING THE PERIOD. STILL POSSIBLE TO HAVE OUTFLOW WINDS THIS EVENING - FROM 02Z TO 05Z - FROM ANY DISTANT STORM...BUT SIGNIFICANT WIND SHIFTS ARE NOT INDICATED IN THE TAF AT THIS TIME. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... TUESDAY THROUGH SATURDAY... MOISTURE WILL STEADILY INCREASE ACROSS THE AREA DURING THE WEEK WITH A NOTEWORTHY INCREASE IN HUMIDITIES TAKING PLACE ON WEDNESDAY. SHOWERS WILL INCREASE IN COVERAGE WEDNESDAY NIGHT THROUGH FRIDAY WITH SOME AREAS POTENTIALLY LOOKING AT PERIODS OF HEAVY RAINFALL. AS SUCH...AFTERNOON HUMIDITIES WILL REMAIN ELEVATED WITH GOOD TO EXCELLENT RECOVERIES EXPECTED. WINDS SHOULD BE LIGHT DURING THE WEEK OUTSIDE OF THUNDERSTORM INDUCED OUTFLOWS. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...AJ AVIATION...MEYERS FIRE WEATHER...MEYERS/LEINS
AREA FORECAST DISCUSSION
NWS MIAMI FL
348 PM EDT SAT SEP 13 2014 .DISCUSSION... THE LATEST CONSENSUS OF THE MODEL GUIDANCE...BOTH THE GLOBAL MODELS AND THE LATEST HRRR RUN...INDICATE THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS TO FORM ACROSS THE FLORIDA STRAITS THIS EVENING AND AFFECT THE SOUTHERN PORTIONS OF SOUTH FLORIDA AND ADJACENT WATERS LATER THIS EVENING AND POSSIBLY CONTINUING INTO THE EARLY MORNING HOURS ON SUNDAY. RECENT SATELLITE IMAGERY AND RADAR RETURNS INDICATE THIS PROCESS IS ALREADY UNDERWAY WITH BANDS OF SHOWERS AND THUNDERSTORMS OBSERVED ACROSS THE FLORIDA STRAITS. OVER NIGHT AND INTO SUNDAY...A BROAD AREA OF SURFACE LOW PRESSURE ACROSS THE EASTERN GULF WILL CONTINUE TO TRACK WESTWARD INTO THE CENTRAL GULF. THE MORE RECENT GUIDANCE HAS CONSISTENTLY BEEN INDICATING THAT DEEP TROPICAL MOISTURE WILL CONTINUE TO LINGER ACROSS SOUTH FLORIDA AND ADJACENT WATERS WITH LOW LEVEL MASS AND MOISTURE CONVERGENCE CONTINUING ACROSS THE REGION INTO SUNDAY MORNING. IN ADDITION THE UPPER LEVEL WINDS COULD BE FAVORABLE FOR SPEED DIVERGENCE DURING THE AFTERNOON HOURS. DAY TIME HEATING AND WITH THE LINGERING DEEP MOISTURE WILL ALLOW FOR AFTERNOON CONVECTION ON SUNDAY WITH THE GREATEST COVERAGE OF SHOWERS AND THUNDERSTORMS EXPECTED INLAND AND WEST. FOR MONDAY AND TUESDAY...SOME RELATIVELY DRIER AIR IS FORECAST TO ENTER THE REGION ALTHOUGH THE GUIDANCE CONSENSUS INDICATES THAT LINGERING MOISTURE COULD BE SUFFICIENT FOR AFTERNOON SHOWERS AND THUNDERSTORMS...MAINLY OVER THE THE PENINSULA. THE EXTENDED GUIDANCE CONTINUES TO SUGGEST THAT LATE NEXT WEEK DEEP MOISTURE COULD EXTEND FROM THE YUCATAN PENINSULA NORTHEASTWARD ACROSS SOUTH FLORIDA AND INTO THE WESTERN ATLANTIC WITH A LARGE AMPLITUDE UPPER LEVEL TROUGH DEEPENING INTO THE CENTRAL GULF. THIS PATTERN IS FORECAST TO LINGER INTO NEXT WEEKEND WITH THE POTENTIAL FOR WIDESPREAD LOCAL CONVECTION. && .MARINE... MAINLY EASTERLY WINDS ARE FORECAST TO BE IN THE 10 TO 15 KNOT RANGE ACROSS THE REGIONAL WATERS TONIGHT THROUGH SUNDAY THEN SLOWLY DECREASING INTO EARLY NEXT WEEK WHILE REMAINING EASTERLY. REGIONAL SEAS ARE FORECAST TO BE MAINLY AROUND 2 FEET OR LESS THE REMAINDER OF THE WEEKEND INTO EARLY NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 87 76 86 76 / 50 40 60 20 FORT LAUDERDALE 87 77 88 79 / 50 50 50 20 MIAMI 87 77 87 78 / 50 50 50 20 NAPLES 89 75 87 76 / 70 40 60 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...23/SK LONG TERM....60/BD
AREA FORECAST DISCUSSION
NWS MIAMI FL
128 PM EDT SAT SEP 13 2014 .AVIATION... SHOWERS WITH ISOLATED THUNDER ARE NOW DEVELOPING NEAR THE EAST COAST TERMINALS, WITH ADDITIONAL DEVELOPMENT THROUGH THE ATLANTIC WATERS. QUESTIONABLE IF EAST COAST TERMINALS WILL FALL BEHIND THE SEA BREEZE, WITH ONLY SHOWERS THE REST OF TODAY, OR WILL CONTINUE TO SEE ADDITIONAL DEVELOPMENT OF THUNDERSTORMS WITH A WEAK UPPER DISTURBANCE CURRENTLY JUST WEST OF THE BAHAMAS. ALTHOUGH VCTS IS IN THE TAFS, IT MAY BE REMOVED LATER IF STORMS DON`T FIRE. THEREFORE, DID NOT INCLUDE ANY TEMPO GROUPS ATTM. FEELING MORE CONFIDENT ABOUT DEVELOPMENT AT APF, AS SEA BREEZE/STORMS MOVE ACROSS THE PENINSULA. LIKE LAST NIGHT, ACTUALLY EXPECTING MORE COVERAGE OF SHOWERS AND STORMS OVERNIGHT AS EASTERLY FLOW CONTINUES. ANOTHER STRONGER VORT MAX NEAR NASSAU WILL ARRIVE JUST EAST OF BISCAYNE BAY TONIGHT. THE HRRR/NAM/GFS ALL PINPOINTING THIS DISTURBANCE FOR HEAVY RAINFALL/NUMEROUS STORMS FROM 0Z-6Z, WHICH COULD VERY WELL SURVIVE INTO KTMB/KMIA/KOPF TONIGHT. THEREFORE, LEFT VCTS IN THROUGH PART OF THE EVENING, WITH THE POTENTIAL FOR SOME MVFR/IFR IF GUIDANCE IS CORRECT. FARTHER NORTH ALONG THE EAST COAST, VCSH WAS USED BUT AGAIN POSSIBLE THAT NUMEROUS SHOWERS AND STORMS AFFECT THOSE TAF SITES TOO. && .PREV DISCUSSION... /ISSUED 1105 AM EDT SAT SEP 13 2014/ UPDATE... WHILE SHOWER AND THUNDERSTORM ACTIVITY HAS SUBSIDED ACROSS THE REGION THIS MORNING...THE POTENTIAL FOR ACTIVE CONVECTION CONTINUES. RECENT VISIBLE SATELLITE IMAGERY INDICATES ACTIVE CONVECTION IN THE EASTERN GULF ASSOCIATED WITH THE AREA OF LOW PRESSURE OFF THE SOUTHWEST FLORIDA COAST AND ADDITIONAL CONVECTION IN THE CENTRAL BAHAMAS ISLANDS. THE 12Z SOUNDING INDICATED A PWAT AROUND 1.9 INCHES AND INDICATED A SIGNIFICANT COOLING TREND IN THE MID LEVELS AS WELL. GIVEN THE GENERAL CLEARING TREND OVER THE PENINSULA THIS MORNING...DAY TIME HEATING IS EXPECTED TO DRIVE CONVECTION THIS AFTERNOON AND EARLY EVENING WITH THE GREATEST COVERAGE OF SHOWERS AND THUNDERSTORMS STILL EXPECTED IN THE WESTERN INTERIOR AND WESTERN PORTIONS OF THE PENINSULA...INCLUDING THE NAPLES METRO AREAS. 60 PREV DISCUSSION... /ISSUED 830 AM EDT SAT SEP 13 2014/ AVIATION... RATHER DISORGANIZED UPPER LOW, WITH A FEW DISTURBANCES TRAILING TO THE EAST, WILL BE THE IMPETUS FOR STORMS TODAY. LARGE MASS OF MID LEVEL DRY AIR PER WATER VAPOR LOOP, MAY STAY NORTH OF THE REGION TODAY, UNLIKE YESTERDAY. PERHAPS SOME OF THIS DRY AIR WILL WRAP INTO THE CIRCULATION OF THE UPPER LOW, BUT THAT MAY NOT MEAN MUCH SINCE THE LOW IS ALREADY OFF THE SW FL COAST. LAMP GUIDANCE INDICATES THAT A SEA BREEZE WILL DEVELOP ALONG THE EAST COAST, PERHAPS KEEPING MOST CONVECTION INLAND AND WEST COAST. THIS IS UP AGAINST THE HRRR WHICH IS AGGRESSIVE PAINTING STORMS ALONG THE BEACHES AND MOST TERMINALS BY MID AFTERNOON. THE TAFS CAN BE FINE TUNED ONCE RAOB DATA ARRIVES, BUT WILL INSERT VCTS FOR NOW, AS PREVIOUS DISCUSSION MENTIONED VCTS FOR ALL TAFS, BUT TAFS ONLY CONTAINED VCSH. PERHAPS SOME OF THE SHOWERS OFFSHORE OF PBI ARRIVE LATER THIS MORNING. PERSISTENCE OF CLOUD COVER ALONG THE EAST COAST WILL ALSO GO A LONG WAY IN DETERMINING STORM EVOLUTION TODAY. CONFIDENCE IS BELOW AVERAGE. PREV DISCUSSION... /ISSUED 431 AM EDT SAT SEP 13 2014/ SHORT TERM...(TODAY-MONDAY) RECENTLY ANIMATED WATER VAPOR LOOP SHOWED AN UPPER LOW CENTERED OVER SOUTH FLORIDA SLOWLY TRACKING WESTWARD AND A RIDGE AXIS ORIENTED FROM EAST TO WEST ACROSS THE NORTHERN GULF COAST STATES. PLENTY OF DEEP LAYER MOISTURE EAST OF THIS UPPER LOW COMBINED WITH UPPER-LEVEL DIVERGENCE WILL CONTINUE TO SUPPORT WIDESPREAD RAINFALL TODAY ESPECIALLY ALONG THE SOUTHEAST COAST AND ACROSS THE ATLANTIC WATERS THROUGH THE MORNING HOURS. THE LATEST HRRR MODEL RUN APPEARS TO HAVE INITIALIZED WELL WITH THE CURRENT RADAR TRENDS AND GENERALLY INDICATES THIS MORNING ACTIVITY CONTINUING ACROSS THE EASTERN AREAS INCLUDING PALM BEACH, BROWARD AND MIAMI-DADE BEFORE SHIFTING INLAND AND TOWARD THE GULF COAST THROUGH THE MID TO LATE AFTERNOON/EARLY EVENING PERIOD. THIS SOLUTION MAKES SENSE WITH THE UPPER LOW SHIFTING WESTWARD AND LIGHT TO MODERATE SOUTHEAST LOW- LEVEL FLOW CONTINUING. THIS PATTERN WILL KEEP THE POTENTIAL FOR LOCALIZED FLOODING UP THROUGH THIS EVENING...ESPECIALLY OVER THE AREAS THAT ARE ALREADY SATURATED FROM EARLIER RAINFALL (AREAS HAVE RECEIVED 2-4 INCHES WITH HIGHER AMOUNTS UP TO 7" JUST INLAND OF BOCA RATON OVER THE PAST 24-36 HRS). MODEL SOUNDINGS SUPPORT THE ACTIVITY TAPERING OFF OVER THE FAR SOUTHEASTERN AREAS OR TOWARD MIAMI THROUGH THE MORNING AND AFTERNOON HOURS WITH MAINLY SATURATED PROFILES ABOVE A SLIGHTLY DRIER LAYER FROM THE SURFACE TO 700MB. AS A RESULT...MAXIMUM TEMPERATURES HAVE BEEN SLIGHTLY UNDERCUT BY A FEW DEGREES COMPARED TO GUIDANCE...MAINLY DUE TO PLENTY OF CLOUD COVERAGE ANTICIPATED. IF THIS COVERAGE BEGINS TO BREAK THROUGH THE DAY...TEMPERATURES WILL NEED TO BE ADJUSTED ACCORDINGLY. THE MOIST TREND WITH SOUTHEAST FLOW WILL PERSIST THROUGH SUNDAY BEFORE SOME DRIER AIR MOVES IN FROM THE WEST AND THE RIDGE BUILDS BACK ACROSS THE REGION INTO THE UPCOMING WEEK. /85 LONG TERM (TUESDAY-FRIDAY)... THE LATEST EXTENDED GUIDANCE REMAINS IN DECENT AGREEMENT ON THE LARGE SCALE AND GENERALLY INDICATES FALLING UPPER HEIGHTS IN RESPONSE TO A DEEPENING UPPER TROUGH ACROSS THE REGION. A FRONTAL BOUNDARY IS PROJECTED TO SHIFT SOUTHWARD AND STALL NORTH OF THE AREA THROUGH THE SECOND HALF OF THE WEEK. THE ECMWF SEEMS TO BE THE MORE BULLISH SOLUTION AND SHOWS THE MOISTURE AXIS ASSOCIATED WITH THIS BOUNDARY PROGRESSING FARTHER SOUTH THAN THE GFS/GFS ENSEMBLE MEAN WITH SSW LOW-LEVEL FLOW SETTING UP OVER THE AREA BY THURSDAY. THE COMBINATION OF THE FRONT AND FALLING UPPER HEIGHTS ALONG WITH SSW LOW-LEVEL FLOW WOULD FAVOR MUCH OF THE RAINFALL SETTING UP OVER THE EAST COAST/METRO AREAS BY THURSDAY. /85 AVIATION... A LARGE AREA OF SHOWERS AND THUNDERSTORMS OVER THE ATLANTIC WATERS WERE DEVELOPING ON THE NORTHEAST SIDE OF THE MID/UPPER LEVEL VORTICITY MOVING WEST ACROSS THE FLORIDA STRAITS. THESE SHOWERS/STORMS WERE MOVING QUICKLY TO THE NORTHWEST TOWARDS THE BROWARD AND MIAMI-DADE TAF SITES...AND THEY MAY MOVE OVER THE TAF SITES THROUGH THE EARLY MORNING HOURS. BRIEF MVFR/IFR CONDITIONS AND GUSTY WINDS UP TO 30 KNOTS ARE POSSIBLE. THE AREA OF LOW PRESSURE OVER THE SOUTHEAST GULF AND THE UPPER LEVEL LOW WILL CONTINUE TO MOVE WEST TODAY AND HAVE LESS OF AN INFLUENCE OVER THE REGION THROUGHOUT THE DAY. THIS COMBINED WITH THE OVERNIGHT CONVECTION MAY LIMIT SHOWER/STORM DEVELOPMENT FOR THE EAST COAST METRO AREAS DURING THE DAY. HOWEVER...DEEP MOISTURE IN THE SOUTHEAST LOW LEVEL FLOW WILL CONTINUE...SO KEPT VCTS IN FOR THE TAF SITES. AT KAPF...SHOWER AND STORM DEVELOPMENT IS FORECAST TO BECOME MORE LIKELY AS THE DAY PROGRESSES...AS THE INFLUENCE OF THE UPPER LOW INCREASES. LIGHT WINDS WILL CONTINUE THROUGH THE OVERNIGHT HOURS OUTSIDE OF SHOWERS AND STORMS...AND THEN BECOME SOUTHEAST AROUND 10 KNOTS DURING THE DAY. /84 MARINE... AN UPPER LOW WILL KEEP THE RAIN CHANCES IN THE FORECAST ACROSS THE MARINE AREAS THROUGH THE REMAINDER OF THE WEEKEND WITH LIGHT TO MODERATE SOUTHEAST WINDS CONTINUING. WINDS AND SEAS WILL BE LOCALLY HIGHER IN AND AROUND HEAVIER SHOWERS AND STORMS. HIGH PRESSURE WILL BUILD BACK ACROSS THE REGION THROUGH THE FIRST HALF OF THE UPCOMING WEEK WITH SOUTHEAST WINDS CONTINUING. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 76 87 76 87 / 30 50 30 50 FORT LAUDERDALE 77 87 79 88 / 40 60 20 50 MIAMI 77 87 78 88 / 40 60 20 50 NAPLES 75 89 76 89 / 30 60 20 50 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...60/BD LONG TERM....85/AG AVIATION...21/KM
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
436 PM EDT SAT SEP 13 2014 .SYNOPSIS... A TROUGH OF LOW PRESSURE WILL MOVE OFF THE COAST THIS EVENING...BUT A FRONTAL BOUNDARY WILL THEN LAY OFF THE SOUTHEAST COAST TONIGHT THROUGH MONDAY. MEANWHILE...HIGH PRESSURE WILL BUILD FROM THE OHIO VALLEY EAST NORTHEAST AND OFF THE NEW ENGLAND COAST TONIGHT THROUGH MONDAY. ANOTHER TROUGH OF LOW PRESSURE WILL AFFECT THE AREA MONDAY EVENING INTO TUESDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AREA OF SCTD SHOWERS (ISLTD THUNDER SE) WILL MOVE THRU CNTRL/ERN CNTIES AND OFF THE CST THIS EVENG...AS A TROF OF LO PRES PUSHES THRU AND OFFSHR. THEN...BECMG MSTLY CLEAR N TO PRTLY/MSTLY CLOUDY S TNGT. LOWS RANGING FM THE MID 50S EXTRM N TO THE MID 60S SE. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... SUN THRU MON...A FRONTAL BOUNDARY WILL LAY OFF THE SE CST...WHILE HI PRES BLDS FM THE OH VLY ENE AND OFF THE NEW ENGLAND CST. THIS WILL RESULT IN MAINLY DRY WX ACRS THE REGION WITH ONLY SLGT CHCS FOR PCPN OVR THE EXTRM S. HI TEMPS ON SUN WILL BE IN THE LWR TO MID 70S...WITH SKY COVER RANGING FM MOSTLY SNY EXTRM N TO MOSTLY CLOUDY EXTRM S. ABT THE SAME SKY CONDITION SUN NGT WITH LOWS RANGING THRU THE 50S INTO THE LWR 60S. PARTLY SNY TO MOSTLY CLOUDY ON MON. WARMER AND BECMG A LITTLE MORE HUMID WITH HIGHS IN THE UPR 70S TO LWR 80S. WILL THEN HAVE CHC POPS (30-40%) FOR THE ENTIRE REGION MON EVENG INTO EARLY TUE MORNG...AS ANOTHER TROF OF LO PRES APPROACHES AND SWINGS THRU. THAT TROF WILL MOVE OUT TO SEA TUE AFTN...WITH HI PRES BLDNG TWD THE AREA FM THE OH VLY. LOWS MON NGT IN THE 60S. HIGHS ON TUE RANGING FM THE MID 70S TO NEAR 80. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... MODELS AGREE THAT THE COLD FRONT IS WELL OFFSHORE WITH HIGH PRESSURE BUILDING INTO THE AREA FROM THE NW TO START MEDIUM RANGE PERIOD. DRY AND COOLER THRU WED NIGHT. LOWS IN THE 50S XCPT 60-65 BEACHES. HIGH WED 70-75. PATTERN FOR THE REST OF THE PERIOD WILL FEATURE A LARGE AREA OF HIGH PRES OVER EASTERN CANADA THAT EXTENDS SOUTH ACROSS THE MID ATLNTC RGN WITH THE OLD FRONTAL BOUNDARY STALLED ACROSS FLA AND IVOF GULF STREAM. LOW PRESSURE PROGGED TO MOVE EAST ALONG THIS BNDRY THU AND FRI. WHAT THIS SCENARIO SUGGESTS IS FOR AN EXTENDED AND INCREASINGLY MOIST NE FLOW ACROSS THE RGN. TIGHTENING PRES GRAD WILL LEAD TO BREEZY TO WINDY CNDTNS AT TIMES ALONG THE COAST. TIMING OF PCPN RATHER PROBLEMATIC THIS FAR OUT BUT WILL CONFINE LOW CHC POPS TO SERN COASTAL AREAS FOR NOW. PT SUNNY NORTH & WEST TO MSTLY CLDY TO CLOUDY SKIES SOUTH & EAST. COOL WITH HIGHS U60S-M70S. LOWS IN THE 50S XCPT 60-65 CSTL AREAS. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... WEAK TROF WILL MOVE ACROSS THE AREA THIS AFTERNOON AND EVENING. THIS IS GENERATING A FEW SHOWERS AS IT MOVES THROUGH THE VERY MOIST AIR MASS OVER THE AREA. TIMING WHAT WE CAN SEE ON THE RADAR AND WITH THE HRRR AND RUC ALL SHOW ABOUT A 4 HOUR WINDOW OF SHOWERS. MAINLY FROM 18 TO 20Z WEST TO 20 TO 00Z EAST. CONDITIONS WILL BE MVFR DURING THE SHOWERS. AFTER THIS TROF MOVES BY STILL NOT A LOT OF FLOW ALOFT TO GET RID OF ALL THE MOISTURE. BUFKIT SOUNDINGS KEEP SOME MID LEVEL MOISTURE AROUND THRU THE NIGHT. SO WILL RAISE CIGS TO VFR TONIGHT. LOOKS LIKE CONTINUED DRYING ON SUNDAY AND KEPT VFR CONDITIONS. OUTLOOK...PCPN AND LOWER CONDITIONS MAY RETURN LATE MONDAY OR TUESDAY WITH A RETURN TO DRY WEATHER ON WEDNESDAY. STILL UNCERTAINTY ABOUT TIMING AND HOW FAR NORTH THE MOISTURE WILL GET IN OUR AREA. && .MARINE... WINDS WILL QUICKLY TURN TO THE NORTH BEHIND THE PASSAGE OF A TROF THIS EVENING. MODELS STILL DEPICTING A DECENT CAA SURGE LATE TONIGHT AND SUNDAY MORNING SO WILL KEEP CRNT SCA HEADLINES. ONLY CHANGE WAS TO BEGING THE SCA HEADLINES WITH THIS ISSUANCE FOR THE CHES BAY SINCE THE WINDS SHOULD INCREASE TO SCA LEVELS ARND MIDNIGHT. WILL LET THE STARTING TIME FOR SCA`S ALONE FOR LATE TONIGHT AS THERE ARE GNRLY FOR 5 FOOT SEAS (ALTHOUGH THERE CUD BE A FEW GUSTS TO 25 KTS LATE TONIGHT). SURGE QUICKLY DMNSHS BY SUNDAY AFTRN SO WILL LET THE SCA`S EXPIRE AT ADVERTISED TIMES. NE FLOW SETS UP SUN NIGHT TINTO MON MORN AT SPEEDS AOB 15 KTS. WINDS SHIFT INTO THE E-SE MONDAY AFTRN AND EVEN AHEAD OF NEXT BNDRY. NEXT COLD FRONTAL PASSAGE EXPECTED TUE MORNING WITH YET ANOTHER MANGINAL CAA SURGE EXPECTED BEHIND IT. MODELS CONTINUE TO INDICATE AN EXTENDED PERIOD OF NE (SCA) WINDS AND SEAS AOA 5 FT STARTING MID WEEK AND PSBLY LASTING INTO NEXT WEEKEND. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...MODERATE RIP CURRENT RISK THROUGH SUNDAY EVENING FOR MDZ025. NC...MODERATE RIP CURRENT RISK THROUGH SUNDAY EVENING FOR NCZ102. VA...MODERATE RIP CURRENT RISK THROUGH SUNDAY EVENING FOR VAZ098>100. MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR ANZ630>632-634- 638. SMALL CRAFT ADVISORY FROM 6 AM TO 1 PM EDT SUNDAY FOR ANZ633. SMALL CRAFT ADVISORY FROM 5 AM TO 11 AM EDT SUNDAY FOR ANZ652- 654-656. SMALL CRAFT ADVISORY FROM 2 AM TO 11 AM EDT SUNDAY FOR ANZ650. SMALL CRAFT ADVISORY FROM 5 AM TO 2 PM EDT SUNDAY FOR ANZ658. && $$ SYNOPSIS...TMG NEAR TERM...TMG SHORT TERM...TMG LONG TERM...MPR AVIATION...JAB MARINE...MPR
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
409 PM EDT SAT SEP 13 2014 .SYNOPSIS... A TROUGH OF LOW PRESSURE WILL MOVE OFF THE COAST THIS EVENING...BUT A FRONTAL BOUNDARY WILL THEN LAY OFF THE SOUTHEAST COAST TONIGHT THROUGH MONDAY. MEANWHILE...HIGH PRESSURE WILL BUILD FROM THE OHIO VALLEY EAST NORTHEAST AND OFF THE NEW ENGLAND COAST TONIGHT THROUGH MONDAY. ANOTHER TROUGH OF LOW PRESSURE WILL AFFECT THE AREA MONDAY EVENING INTO TUESDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AREA OF SCTD SHOWERS (ISLTD THUNDER SE) WILL MOVE THRU CNTRL/ERN CNTIES AND OFF THE CST THIS EVENG...AS A TROF OF LO PRES PUSHES THRU AND OFFSHR. THEN...BECMG MSTLY CLEAR N TO PRTLY/MSTLY CLOUDY S TNGT. LOWS RANGING FM THE MID 50S EXTRM N TO THE MID 60S SE. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... MAINLY DRY WEATHER IS EXPECTED SUNDAY THROUGH MONDAY WITH ONLY SLGT CHANCES FOR PCPN IN THE FAR SOUTH. HIGH TEMPERATURES HOLD IN THE 70S SUNDAY. DUE TO AN INCREASE OF SUNSHINE FROM EARLIER FORECASTS...HAVE INCREASED TEMPERATURES TO NEAR 80 OVER MOST INLAND SECTIONS ON MONDAY WITH READINGS HOLDING IN THE MID 70S ON THE LOWER EASTERN SHORE. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... MODELS AGREE THAT THE COLD FRONT IS WELL OFFSHORE WITH HIGH PRESSURE BUILDING INTO THE AREA FROM THE NW TO START MEDIUM RANGE PERIOD. DRY AND COOLER THRU WED NIGHT. LOWS IN THE 50S XCPT 60-65 BEACHES. HIGH WED 70-75. PATTERN FOR THE REST OF THE PERIOD WILL FEATURE A LARGE AREA OF HIGH PRES OVER EASTERN CANADA THAT EXTENDS SOUTH ACROSS THE MID ATLNTC RGN WITH THE OLD FRONTAL BOUNDARY STALLED ACROSS FLA AND IVOF GULF STREAM. LOW PRESSURE PROGGED TO MOVE EAST ALONG THIS BNDRY THU AND FRI. WHAT THIS SCENARIO SUGGESTS IS FOR AN EXTENDED AND INCREASINGLY MOIST NE FLOW ACROSS THE RGN. TIGHTENING PRES GRAD WILL LEAD TO BREEZY TO WINDY CNDTNS AT TIMES ALONG THE COAST. TIMING OF PCPN RATHER PROBLEMATIC THIS FAR OUT BUT WILL CONFINE LOW CHC POPS TO SERN COASTAL AREAS FOR NOW. PT SUNNY NORTH & WEST TO MSTLY CLDY TO CLOUDY SKIES SOUTH & EAST. COOL WITH HIGHS U60S-M70S. LOWS IN THE 50S XCPT 60-65 CSTL AREAS. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... WEAK TROF WILL MOVE ACROSS THE AREA THIS AFTERNOON AND EVENING. THIS IS GENERATING A FEW SHOWERS AS IT MOVES THROUGH THE VERY MOIST AIR MASS OVER THE AREA. TIMING WHAT WE CAN SEE ON THE RADAR AND WITH THE HRRR AND RUC ALL SHOW ABOUT A 4 HOUR WINDOW OF SHOWERS. MAINLY FROM 18 TO 20Z WEST TO 20 TO 00Z EAST. CONDITIONS WILL BE MVFR DURING THE SHOWERS. AFTER THIS TROF MOVES BY STILL NOT A LOT OF FLOW ALOFT TO GET RID OF ALL THE MOISTURE. BUFKIT SOUNDINGS KEEP SOME MID LEVEL MOISTURE AROUND THRU THE NIGHT. SO WILL RAISE CIGS TO VFR TONIGHT. LOOKS LIKE CONTINUED DRYING ON SUNDAY AND KEPT VFR CONDITIONS. OUTLOOK...PCPN AND LOWER CONDITIONS MAY RETURN LATE MONDAY OR TUESDAY WITH A RETURN TO DRY WEATHER ON WEDNESDAY. STILL UNCERTAINTY ABOUT TIMING AND HOW FAR NORTH THE MOISTURE WILL GET IN OUR AREA. && .MARINE... WINDS WILL QUICKLY TURN TO THE NORTH BEHIND THE PASSAGE OF A TROF THIS EVENING. MODELS STILL DEPICTING A DECENT CAA SURGE LATE TONIGHT AND SUNDAY MORNING SO WILL KEEP CRNT SCA HEADLINES. ONLY CHANGE WAS TO BEGING THE SCA HEADLINES WITH THIS ISSUANCE FOR THE CHES BAY SINCE THE WINDS SHOULD INCREASE TO SCA LEVELS ARND MIDNIGHT. WILL LET THE STARTING TIME FOR SCA`S ALONE FOR LATE TONIGHT AS THERE ARE GNRLY FOR 5 FOOT SEAS (ALTHOUGH THERE CUD BE A FEW GUSTS TO 25 KTS LATE TONIGHT). SURGE QUICKLY DMNSHS BY SUNDAY AFTRN SO WILL LET THE SCA`S EXPIRE AT ADVERTISED TIMES. NE FLOW SETS UP SUN NIGHT TINTO MON MORN AT SPEEDS AOB 15 KTS. WINDS SHIFT INTO THE E-SE MONDAY AFTRN AND EVEN AHEAD OF NEXT BNDRY. NEXT COLD FRONTAL PASSAGE EXPECTED TUE MORNING WITH YET ANOTHER MANGINAL CAA SURGE EXPECTED BEHIND IT. MODELS CONTINUE TO INDICATE AN EXTENDED PERIOD OF NE (SCA) WINDS AND SEAS AOA 5 FT STARTING MID WEEK AND PSBLY LASTING INTO NEXT WEEKEND. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...MODERATE RIP CURRENT RISK THROUGH SUNDAY EVENING FOR MDZ025. NC...MODERATE RIP CURRENT RISK THROUGH SUNDAY EVENING FOR NCZ102. VA...MODERATE RIP CURRENT RISK THROUGH SUNDAY EVENING FOR VAZ098>100. MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR ANZ630>632-634- 638. SMALL CRAFT ADVISORY FROM 6 AM TO 1 PM EDT SUNDAY FOR ANZ633. SMALL CRAFT ADVISORY FROM 5 AM TO 11 AM EDT SUNDAY FOR ANZ652- 654-656. SMALL CRAFT ADVISORY FROM 2 AM TO 11 AM EDT SUNDAY FOR ANZ650. SMALL CRAFT ADVISORY FROM 5 AM TO 2 PM EDT SUNDAY FOR ANZ658. && $$ SYNOPSIS...TMG NEAR TERM...TMG SHORT TERM...TMG LONG TERM...MPR AVIATION...JAB MARINE...MPR
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
148 PM EDT SAT SEP 13 2014 .SYNOPSIS... A FRONTAL BOUNDARY WILL REMAIN OVER THE CAROLINAS THROUGH EARLY NEXT WEEK. A TROUGH OF LOW PRESSURE WILL MOVE FROM WEST TO EAST ACROSS THE MID ATLANTIC STATES THIS AFTERNOON AND EARLY TONIGHT. HIGH PRESSURE BUILDS INTO THE AREA FROM THE NORTHWEST SUNDAY AND MONDAY. ANOTHER LOW PRESSURE SYSTEM WILL AFFECT THE AREA MONDAY NIGHT AND TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... AREA OF SCTD SHOWERS WAS MOVING INTO WRN/CNTRL CNTIES LATE THIS MORNG...AND WILL SPREAD ACRS THE REGION FM W TO E THIS AFTN INTO TNGT...AS A TROF OF LO PRES PUSHING ACRS THE AREA AND OFF THE CST. WILL MAINTAIN LIKELY POPS (60-70%) EVERYWHERE THRU THIS AFTN...EVEN THO RAINFALL AMTS WILL GENERALLY BE .25 INCH OR LESS OVR MOST OF THE RGION. HIGHER AMTS POSSIBLE OVR NE NC LATER TODAY INTO TNGT. INSTABILITY WILL BE MARGINAL IN THE SE...SO HAVE JUST SLGT CHC OF TSTM. HI TEMPS RANGING FM THE LWR 70S EXTRM NW TO THE LWR 80S EXTRM SE. && .SHORT TERM /SUNDAY THROUGH MONDAY/... MAINLY DRY WEATHER IS EXPECTED SUNDAY THROUGH MONDAY WITH ONLY SLGT CHANCES FOR PCPN IN THE FAR SOUTH. HIGH TEMPERATURES HOLD IN THE 70S SUNDAY. DUE TO AN INCREASE OF SUNSHINE FROM EARLIER FORECASTS...HAVE INCREASED TEMPERATURES TO NEAR 80 OVER MOST INLAND SECTIONS ON MONDAY WITH READINGS HOLDING IN THE MID 70S ON THE LOWER EASTERN SHORE. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... CONTINUED TO FAVOR THE ECMWF SOLN DURING THIS PERIOD. LOW PRESSURE AND ASSCTD COLD FRONT MOVE ACROSS THE AREA MON NIGHT AND TUE. THIS RUN A BIT FASTER WITH FROPA (TUES MORNING) THEN SHIFTS OFFSHORE. SOME INSTAB NOTED AHEAD OF BNDRY SO WILL KEEP CHC POPS THRU THE PERIOD WITH THUNDER CHCS OVR SRN SCTNS. MILD AHEAD OF THE BNDRY WITH LOWS MON NITE IN THE 60S. HIGHS TUE 75-80. FRONTAL BNDRY STALLS ACROSS THE CAROLINAS AS CANADIAN HIGH PRESSURE BUILDS INTO THE AREA FOR THE MID WEEK PRD. MOST OF THE SGNFCNT MSTR GETS PUSHES JUST SOUTH OF THE FA...SO WILL INDCT A DRY PRD WED AND WED NIGHT. COOLER WITH LOWS IN THE 50S XCPT 60S BEACH AREAS. HIGHS WED 70-75. GIVEN HIGHS PRS TO THE NORTH AND STALLED FRNTL BNDRY TO THE SOUTH... XPCT THE PERSISTENT & INCREASINGLY MOIST NE FLOW TO KEEP CSTL AREAS RTHR CLDY WITH PERIODIC SHWR CHCS ACROSS SERN CSTL AREAS. OTW...HIGH PRS TO THE NORTH DOMINATES. HIGHS L-M70S. LOWS IN THE 50S XCPT 60S CSTL AREAS. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... WEAK TROF WILL MOVE ACROSS THE AREA THIS AFTERNOON AND EVENING. THIS IS GENERATING A FEW SHOWERS AS IT MOVES THROUGH THE VERY MOIST AIR MASS OVER THE AREA. TIMING WHAT WE CAN SEE ON THE RADAR AND WITH THE HRRR AND RUC ALL SHOW ABOUT A 4 HOUR WINDOW OF SHOWERS. MAINLY FROM 18 TO 20Z WEST TO 20 TO 00Z EAST. CONDITIONS WILL BE MVFR DURING THE SHOWERS. AFTER THIS TROF MOVES BY STILL NOT A LOT OF FLOW ALOFT TO GET RID OF ALL THE MOISTURE. BUFKIT SOUNDINGS KEEP SOME MID LEVEL MOISTURE AROUND THRU THE NIGHT. SO WILL RAISE CIGS TO VFR TONIGHT. LOOKS LIKE CONTINUED DRYING ON SUNDAY AND KEPT VFR CONDITIONS. OUTLOOK...PCPN AND LOWER CONDITIONS MAY RETURN LATE MONDAY OR TUESDAY WITH A RETURN TO DRY WEATHER ON WEDNESDAY. STILL UNCERTAINTY ABOUT TIMING AND HOW FAR NORTH THE MOISTURE WILL GET IN OUR AREA. && .MARINE... SFC HI PRES MOVES OFF TO THE NE OF THE WTRS THROUGH TDA. ONSHORE WNDS (LIGHTER THAN PAST 24 HRS) THROUGH THE MRNG...BECOME BRIEFLY SSW AHD OF APPROACHING LO PRES AND ASSOCIATED CDFNT FM THE W. SUB-SCA CONDS XPCD THROUGH THIS EVE. THAT CDFNT CROSSES THE WTRS MID EVE...A BIT OF A LULL IN SPEEDS AS WNDS BECOME NLY POST FROPA. AS SFC HI PRES FM THE OH VLY BUILDS E TNGT...SPEEDS TO INCRS TO 15-20 KT OVR MOST OF THE WTRS AFT MDNGT...AND RESULT IN INCRS IN WAVES (BAY)/SEAS (OCN) THROUGH SUN MRNG. WNDS TO BEGIN TO SUBSIDE MIDDAY/AFTN SUN AND WAVES/SEAS WILL BE SLO TO LWR AS WELL (LASTLY INVOF FAR SRN OCN WTRS). RAISING SCAS FOR BAY/OCN/SND...MNLY FM AFT MDNGT TNGT THROUGH MRNG/EARLY AFTN SUN. ANOTHOR LO PRES SYS AND ASSOCIATED CD CDFRNT PROGGED ACROSS THE AREA MON NGT AND TUE. EXPECT W-SW FLOW AHEAD OF THIS SYS SHIFTING BACK TO THE N AFT FROPA WITH YET ANOTHER CAA SURGE LIKELY. DATA INDICATES THAT AN EXTENDED PERIOD OF NE WINDS AND INCREASED SEAS APPEAR LIKELY LATE NEXT WEEK. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR MDZ025. NC...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR NCZ102. VA...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR VAZ098>100. MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 11 AM EDT SUNDAY FOR ANZ630>632-634-638. SMALL CRAFT ADVISORY FROM 6 AM TO 1 PM EDT SUNDAY FOR ANZ633. SMALL CRAFT ADVISORY FROM 5 AM TO 11 AM EDT SUNDAY FOR ANZ652- 654-656. SMALL CRAFT ADVISORY FROM 2 AM TO 11 AM EDT SUNDAY FOR ANZ650. SMALL CRAFT ADVISORY FROM 5 AM TO 2 PM EDT SUNDAY FOR ANZ658. && $$ SYNOPSIS...LSA NEAR TERM...TMG/LSA SHORT TERM...LSA/JAB LONG TERM...MPR AVIATION...LSA MARINE...ALB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
410 PM EDT SAT SEP 13 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 409 PM EDT SAT SEP 13 2014 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW THE VIGOROUS SHORTWAVE THAT PRODUCED PCPN OVER MUCH OF UPPER MI LAST NIGHT NOW MOVING THRU SRN ONTARIO INTO QUEBEC. UPSTREAM...A PAIR OF SHORTWAVES ARE NOTED...ONE OVER ND/SRN MANITOBA AND THE OTHER OVER SRN SASKATCHEWAN. THESE WAVES WILL BRING THE NEXT PCPN CHC TO UPPER MI ON SUNDAY. IN THE WAKE OF LAST NIGHTS SYSTEM...850MB TEMPS ARE CURRENTLY -1 TO -2C OVER LAKE SUPERIOR. TYPICALLY AT THIS TIME OF YEAR...THIS WOULD BE MORE THAN SUFFICIENT FOR LAKE EFFECT CLOUDS AND PCPN. HOWEVER...WITH A LARGE PORTION OF LAKE SUPERIOR HAVING SFC WATER TEMPS PROBABLY ONLY AROUND 7-9C...THERE WAS NOT MUCH IN THE WAY OF LAKE EFFECT CLOUDS EARLIER TODAY. IN FACT...THE LAKE HAS BEHAVED MOSTLY AS STABILIZING INFLUENCE. ONE BAND WITH A FEW SPRINKLES DID STREAM INTO ERN MARQUETTE COUNTY BRIEFLY THIS MORNING DUE TO LAND BREEZE CONVERGENCE AND WARMER WATER TO THE S AND E OF THE KEWEENAW. THIS AFTN...DAYTIME HEATING/LOW-LEVEL CONVERGENCE AND MOISTURE FROM THE LAKE RESULTED IN ADDITIONAL SPRINKLES DEVELOPING IN ERN MARQUETTE COUNTY. THESE SPRINKLES ARE DRIFTING SE THRU DELTA AND WRN ALGER COUNTIES. WHILE LAKE EFFECT CLOUDS WERE AT A MINIMUM EARLIER TODAY...850MB THERMAL TROF COMBINED WITH ADDED MOISTURE FROM THE LAKE RESULTED IN WIDESPREAD CU/STRATOCU DEVELOPING OVER THE LAND ONCE DAYTIME HEATING BEGAN. TONIGHT...MAIN FCST CONCERN IS FROST POTENTIAL. WHILE CU/STRATOCU IS STILL QUITE EXTENSIVE...THE DIURNAL NATURE OF THE CLOUD DEVELOPMENT SUGGESTS THE CLOUDS WILL DISSIPATE THIS EVENING WITH THE LOSS OF DAYTIME HEATING. MEANWHILE...LEAD SHORTWAVE TO THE W IS GENERATING A FAIR AMOUNT OF HIGH CLOUDINESS WHICH WILL STREAM OVER THE FCST AREA AS THE WAVE MOVES OVER THE UPPER LAKES. DISSIPATING STRATOCU THIS EVENING BEING REPLACED BY HIGH CLOUDS WILL BE ONE FACTOR HELPING TO KEEP TEMPS FROM CRASHING. OTHER FACTOR WILL BE DEPARTURE OF HIGH PRES RIDGE CURRENTLY OVER THE AREA. AS PRES GRADIENT TIGHTENS BTWN THE EXITING HIGH AND APPROACHING SFC TROF... THERE WILL BE SOME INCREASE IN MIXING. THAT SAID...THE INITIAL DRY AIR MASS (PRECIPITABLE WATER 45-55PCT OF NORMAL) AND LIGHT WINDS OVER THE AREA WILL STILL ALLOW TEMPS TO FALL INTO THE MID 30S AND TO EVEN THE LOWER 30S IN TRADITIONAL COLD SPOTS. SO...FCST WILL SHOW PATCHY FROST OVER MUCH OF THE INTERIOR. AT THIS POINT...NOT EXPECTING COVERAGE TO BE LARGE ENOUGH TO WARRANT A FROST ADVY. EVENING SHIFT WILL NEED TO MONITOR CLOUD TRENDS AND TEMPS TO RE-EXAMINE THE NEED FOR HEADLINE ISSUANCE BY LATE EVENING. ON SUN...SECOND SHORTWAVE WILL SWING ACROSS THE UPPER GREAT LAKES. AS IN PREVIOUS DAYS...MODELS CONTINUE TO INDICATE BEST MOISTURE/FORCING PASSING JUST N OF THE AREA...ALONG AND N OF PROJECTED VORT TRACK. SEE NO REASON TO DEVIATE MUCH FROM PREVIOUS FCST WITH MAINLY CHC POPS SPREADING INTO WRN UPPER MI IN THE MID TO LATE MORNING AND THEN REACHING THE E MID TO LATE AFTN. EXPECT HIGH TEMPS GENERALLY IN THE UPPER 50S TO LWR 60S. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 350 PM EDT SAT SEP 13 2014 SPLIT FLOW PATTERN ALOFT TO START THE LONG TERM PERIOD BUT NORTHERN BRANCH IS BY FAR STRONGER AND MORE INFLUENTIAL ON THE WEATHER OVER MUCH OF NORTH AMERICA. TROUGHING CENTERED OVER NUNAVUT CANADA TO THE NORTH OF HUDSON BAY WILL KEEP A TROUGH/BELOW NORMAL TEMPS OVER MOST OF CANADA AND INTO THE GREAT LAKES AND REST OF THE EASTERN CONUS THIS WEEK. RIDGING OVER THE WESTERN CONUS AND WESTERN CANADA SHOULD SLOWLY SLIDE EAST BY THE END OF THE WEEK AS DEEP TROUGH CURRENTLY OVER ALASKA RE-ORIENTS OVER THE GULF OF ALASKA WHILE SLIGHTLY OPENING UP. MAY SEE A WARM UP LATE THIS WEEK AND BEYOND AS RIDGING...OR AT LEAST LESS TROUGHING...AFFECTS THE PLAINS AND GREAT LAKES. PATTERN DOES NOT LOOK TO PROVIDE MUCH IN WAY OF RAIN THE NEXT WEEK. PRIMARY CHANCES WOULD BE WITH COLD FRONT MOVING THROUGH ON TUESDAY NIGHT AND AGAIN BY NEXT WEEKEND AS WARM AIR ADVECTION STARTS TO SPREAD IN FROM THE WEST. SUNDAY NIGHT INTO MONDAY...SHORTWAVE AND ASSOCIATED COLD FRONT MOVES OUT OF EASTERN CWA AFTER MIDNIGHT ON SUNDAY NIGHT. WILL LINGER SLIGHT CHANCE POPS OVER THE EAST AFTER MIDNIGHT. THERMAL TROUGH WITH LOWER H7 TEMPS AND A POCKET OF H85-H7 RH ALONG WITH DAYTIME HEATING MAY RESULT IN ISOLD SHRA VCNTY OF LAKE BREEZES OVER EASTERN CWA ON MONDAY AFTN. DRYING AND SUBSIDENCE IN WAKE OF THE SUNDAY NIGHT SHORTWAVE SHOULD LIMIT COVERAGE AND WILL ONLY KEEP SLIGHT CHANCES. LI/S ARE A BIT BLO 0C BUT THINK THAT WITH FROPA WITHIN PREVIOUS 12 HR...THERE WILL ONLY BE ENOUGH INSTABILITY FOR SHRA SO DID NOT MENTION ANY THUNDER. SFC RIDGE SETTLES FROM THE NORTHERN PLAINS TO THE OHIO VALLEY BY TUESDAY MORNING. COULD BE HIGH CLOUDS ON MONDAY NIGHT...BUT PWATS ARE BLO 50 PCT OF NORMAL SO IT COULD BE CHILLY NIGHT WITH SOME FROST POSSIBLE. WINDS LIGHT NEAR THE RIDGE AND THERE IS LIMITED ONSHORE COMPONENT ANYWHERE IN CWA...SEEMS THAT ALL INTERIOR WOULD BE AT RISK FOR THE COLD TEMPS/FROST. TUESDAY SHOULD BE DRY AS UPPER LAKES IS BTWN THE RIDGE AND AN APPROACHING COLD FRONT. WSW WINDS AHEAD OF FRONT AND H85 TEMPS UP TO 4-6C SHOULD RESULT IN TEMPS INTO THE 60S WHICH IS AT LEAST CLOSER TO NORMAL. FRONT DROPS NORTH TO SOUTH OVER THE AREA ON TUESDAY NIGHT OR WEDNESDAY MORNING. A BRIEF INTERLUDE OF INCREASING H8-H6 MOISTURE AND WEAK LIFT JUST IN WAKE OF THE FRONT MAY BE ENOUGH TO KICK OFF SOME SHOWERS TUESDAY NIGHT. COVERAGE OF ANY SHOWERS WILL BE HELD BACK AS STRONGER FORCING FOR LIFT REMAINS OVER NORTHERN ONTARIO CLOSER TO TRACK OF UPPER LEVEL JET DIGGING INTO THE PERSISTENT TROUGH. INTO WEDNESDAY...COULD BE A LOT OF LOW CLOUDS LINGERING BENEATH SUBSIDENCE ALOFT AS SUB H85 IT REMAINS COOL AND MOIST WITH EASTERLY FLOW. ADDITIONAL MID CLOUDS MAY STREAM ACROSS IN THE AFTN AS WELL. TEMPS WILL BE MUCH COOLER THAN THE DAY BEFORE AND IT WILL ESPECIALLY FEEL THAT WAY WITH THE CLOUDS AND EAST WIND. TEMPS IN THE LOW 50S NEAR LK SUPERIOR AND NEAR 60 OVER THE SCNTRL. AS TROUGH ALOFT OVER EASTERN CANADA AND THE NORTHEAST CONUS SLOWLY MOVES EAST AND RIDGE OVER WESTERN CONUS ALSO MOVES EAST...CONFLUENT FLOW RESULTS IN SFC RIDGE MOVING FROM CNTRL CANADA ACROSS THE GREAT LAKES AND EVENTUALLY TO THE EASTERN SEABOARD BY SATURDAY. DRY WEATHER SHOULD HOLD OVER UPPER LAKES THROUGH THU NIGHT...WITH CHANCES FOR RAIN INCREASING BY NEXT WEEKEND AS SHORTWAVE TROUGH MOVES TO THE CNTRL PLAINS AND SFC FRONT SLIDES EASTWARD. LATEST GFS WHICH HAD BEEN VERY AGRESSIVE IN PREVIOUS MODEL RUNS BRINGING QPF TO THE UPPER GREAT LAKES BY FRIDAY NOW LOOKS SIMILAR TO THE SLOWER 00Z ECMWF. ON THE FLIP SIDE...THE LATEST ECMWF IS MUCH MORE BULLISH BRINGING QPF ACROSS ALL OF UPR MICHIGAN BY FRIDAY AFTN AS WHERE IT HAD BEEN INSISTENT ON A RIDGE...IT HAS A STRONGER SHORTWAVE TROUGH. MODEL CONSISTENCY IS LACKING AND WILL GO WITH A CONSENSUS OF ALL THE MODELS WITH LOW CHANCES FOR SHRA/TSRA BEGINNING ON FRIDAY AND LASTING INTO NEXT WEEKEND. GENERALLY...TEMPS WILL RUN BELOW NORMAL THE UPCOMING WEEK...THOUGH IT DOES APPEAR THAT IN ADDITION TO THE WARMER TEMPS ON TUESDAY AHEAD OF A COLD FRONT...READINGS ON FRIDAY AND SATURDAY MAY TRY TO PUSH TO AROUND NORMAL. WILL ALL DEPEND ON EXTENT OF CLOUDS AND SHRA/TSRA. COUPLE OF CHILLY NIGHTS POSSIBLE WEDNESDAY NIGHT AND THURSDAY NIGHT AS THE HIGH IS IN THE VCNTY AND PWATS ARE WELL BLO 50 PCT OF NORMAL. IF SKIES ARE MAINLY CLEAR EITHER NIGHT...TEMPS COULD BE AROUND FREEZING AND THERE WOULD BE FROST. ATTM...BEST CHANCE FOR IDEAL RADIATIONAL COOLING CONDITIONS WOULD BE ON WEDNESDAY NIGHT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 137 PM EDT SAT SEP 13 2014 UNDER RELATIVELY DRY LOW LEVELS...VFR CONDITIONS WILL PREVAIL THRU THE FCST PERIOD AT KIWD/KCMX/KSAW. THERE ARE A COUPLE OF MINOR CONCERNS. A FEW -SHRA/SPRINKLES THAT HAVE POPPED UP IN THE KSAW VCNTY SHOULD LINGER FOR THE NEXT COUPLE OF HRS. ON SUN...AN APPROACHING LOW PRES TROF SHOULD BRING SCT -SHRA INTO NW UPPER MI BY AFTN. HAVE INCLUDED A VCSH MENTION AT KCMX...BUT DO NOT EXPECT CONDITION TO FALL BLO VFR. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 409 PM EDT SAT SEP 13 2014 APPROACHING LOW PRES TROF WILL RESULT IN INCREASING S TO SW WINDS TONIGHT INTO SUN. WHILE LOWER OBS PLATFORMS SHOULDN`T SEE WINDS GREATER THAN THE 10-20KT RANGE...HIGH OBS PLATFORMS WILL PROBABLY SEE GUSTS TO AROUND 25KT. WINDS SHOULD FALL BACK TO MOSTLY 10-20KT SUN NIGHT THRU MON. THERE MAY BE SOMEWHAT HIGHER WINDS AGAIN LATE MON NIGHT THRU EARLY WED AHEAD OF AND BEHIND A COLD FRONT THAT WILL DROP S ACROSS LAKE SUPERIOR TUE. LIGHTER WINDS WILL THEN BE THE RULE LATER WED THRU THU HAS HIGH PRES MOVE SE ACROSS NRN ONTARIO TOWARD THE LOWER LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS BISMARCK ND
338 PM CDT SAT SEP 13 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 329 PM CDT SAT SEP 13 2014 COLD FRONT MOVING THROUGH THE REGION WILL GENERATE WIDELY SCATTERED SHOWERS ACROSS NORTHERN NORTH DAKOTA THIS AFTERNOON AND EARLY THIS EVENING. GENERALLY FOLLOWED THE HRRR IN AREA AND TIMING OF THE SHOWERS. SHOWERS WILL END BEFORE MIDNIGHT. SKIES WILL CLEAR WITH OVERNIGHT LOWS IN THE LOWER TO MIDDLE 30S WEST. ISSUED A FROST ADVISORY ACROSS THE WEST...GENERALLY WEST OF THE MISSOURI RIVER AND WEST OF MINOT. SURFACE HIGH PRESSURE WILL COVER THE REGION SUNDAY AND ANOTHER ROUND OF PATCH FROST IS POSSIBLE SUNDAY NIGHT. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 329 PM CDT SAT SEP 13 2014 THE EXTENDED PERIOD WILL REMAIN LARGELY DRY THROUGH THURSDAY AS A LARGE UPPER LOW ACROSS EASTERN CANADA SLOWLY MOVES EAST. AS THIS HAPPENS BROAD RIDGING WILL DEVELOP OVER THE CENTRAL AND NORTHERN PLAINS. THIS WILL ALLOW A SLOW WARMING TREND THROUGH THE MIDDLE TO AND OF NEXT WEEK. BY NEXT WEEKEND A COLD FRONT WILL MOVE THROUGH BRINGING SCATTERED THUNDERSTORMS TO THE REGION THURSDAY NIGHT INTO FRIDAY NIGHT. FOR TEMPERATURES...SUNDAY NIGHT COULD SEE SOME SCATTERED FROST BEFORE THE WARMUP BEGINS. OTHER THAN THAT...MORNING LOWS WILL B IN THE 40S TO MIDDLE 50S WITH HIGHS IN THE 60S MONDAY AND THE 70S TO AROUND 80 TUESDAY THROUGH SATURDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 329 PM CDT SAT SEP 13 2014 COLD FRONT PROGRESSING THROUGH THE REGION. WHILE VFR CONDITIONS ARE FORECAST THROUGH THE PERIOD...CLOUDS AS LOW AS 3 THOUSAND AGL EXPECTED KDIK-KISN-KMOT AS THE COOLER AIR MOVES IN. SCATTERED SHOWERS EXPECTED ACROSS THE NORTH UNTIL 03Z.BUT TOO WIDELY SCATTERED TO INCLUDE IN THE TAF AT THIS TIME. && .BIS WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY FROM 3 AM CDT /2 AM MDT/ TO 9 AM CDT /8 AM MDT/ SUNDAY FOR NDZ001-002-009-010-017>021-031>034-040>045. && $$ SHORT TERM...WAA LONG TERM...WAA AVIATION...WAA
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
109 PM CDT SAT SEP 13 2014 .UPDATE... ISSUED AT 101 PM CDT SAT SEP 13 2014 NO CHANGES NEEDED. FRONT TO REACH DVL 21Z OR SO WITH PSBL SHOWER THEN A BIT BETTER CHC INTO THE NRN-CNTRL RRV 01-02Z. UPDATE ISSUED AT 1017 AM CDT SAT SEP 13 2014 FCST GOING AS PLANNED...HIGH AND MID LEVEL CLOUDS OVER THE FCST AREA IN AREA OF 850 MB WARM ADVECTION. 925 MB WINDS IN THE 25-30 KT RANGE 15-21Z WILL START TO GET TO THE SURFACE AS TEMPS WARM. MAIN SFC LOW WEST OF BRANDON MANITOBA...MOVING EAST. RAIN SHOWERS MOSTLY ASSOC WITH UPPER LOW JUST NORTH OF REGINA SK AND MODELS CONTINUE TO KEEP MOST OF THE PRECIP WITH THIS EVENT JUST NORTH OF THE BORDER TONIGHT THEN OVER LAKE OF THE WOODS REGION AND ONTARIO SUNDAY. WILL CONTINUE WITH LOWER POPS SOUTH OF LOW WITH HRRR SHOWING SOME SHOWERS LATER AFTN-EVE MOVING INTO NE ND/NRN RRV. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 338 AM CDT SAT SEP 13 2014 NO CHANGE IN THE CURRENT FROST ADVISORY...ALTHOUGH A FEW LOCATIONS OVER THE FAR EASTERN CWFA ARE IN THE MID 20S AT 08Z. WITH CIRRUS INCREASING AND RETURN FLOW DEVELOPING DO NOT EXPECT TEMPERATURES TO FALL MORE THAN 1 OR 2 DEGREES IN THE KVWU...KBJI...KBDO AND KADC AREAS. TODAY WILL BE A TRANSITION DAY. AS THE UNSEASONALLY COLD HIGH MOVES SOUTH...LOW PRESSURE INTENSIFIES OVER SASKATCHEWAN SOUTH WINDS WILL INCREASE BY MID DAY. THE MODELS INITIALIZED WELL AND WILL FOLLOW THE HIGHER RESOLUTION HRRR AND NAM12 TODAY...BLENDING THE NAM/GFS FOR TONIGHT INTO SUNDAY MORNING. TIMING OF WARM ADVECTION PRECIPITATION AHEAD OF WELL DEFINED UPPER WAVE OVER FAR NORTH-CENTRAL MONTANA SIMILAR TO PREVIOUS FORECAST REACHING THE DEVILS LAKE BASIN AROUND 18Z AND SPREADING EAST. NAM/GFS HAVE SMALL AREA OF 0C SHOWALTERS AND SOME ML CAPE BUT WILL NOT MENTION TSRA ATTM. WITH WELL MIXED LAYER TO AROUND 800 MB...35 KTS AT 850 IN THE NAM AND NEAR 30 KTS IN THE GFS TRANSLATE TO GUSTS CLOSE TO 30 KTS POSSIBLE. MOS HAS 27 KTS AND WILL FOLLOW THAT FOR THE 18Z - 00Z PERIOD. SECOND STRONGER SHORTWAVE...DROPPING ALONG THE ALBERTA/SASKATCHEWAN BORDER IS FORECAST TO BE NEAR KDVL AT 06Z TONIGHT. SURFACE LOW SLOWS AND WRAP AROUND SHRA SPREADING OVER THE EAST HALF OF THE CWFA INTO SUNDAY MORNING. THE COLUMN COOLS AND DRIES MOST AREAS SUNDAY...WITH LINGERING SHRA OVER THE NORTHEAST PORTION OF THE CWFA...WITH STRONGER MID-UPPER CAA ALONG SHEAR AXIS AND ENTRANCE REGION OF UPPER JET. THIS QUICKLY MOVES OUT WITH PRECIPITATION ENDING BY 00Z MONDAY. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 338 AM CDT SAT SEP 13 2014 WINDS DIMINISH AND SKIES CLEAR AS HIGH PRESSURE MOVES ACROSS THE CWFA. LOWS WILL FALL BACK INTO THE LOW TO MID 30S...BUT EXPECT SUFFICIENT MIXING AT THIS TIME TO KEEP FROST/FREEZE RISK MINIMAL FOR MONDAY MORNING. LIGHT SOUTHWEST WINDS AND PLENTIFUL SUNSHINE WILL ALLOW MODEST WARM-UP MONDAY TO NEAR MID SEPTEMBER NORMALS. RISING HEIGHTS AND CONTINUED WESTERLY FLOW WILL MAKE FOR A MAINLY CLEAR AND MILD MONDAY NIGHT. TUESDAY TO FRIDAY...CONFLUENT NW FLOW ALOFT FOR MUCH OF THE WEEK WITH A QUICK TRANSITIONING PERIOD THURSDAY INTO FRIDAY. AS A RESULT DRY CONDITIONS EXPECTED WITH MODERATING TEMPS AS THICKNESSES INCREASE WITH RIDGING OVER THE FA BY THURSDAY. BY THURSDAY PM OR FRIDAY DEPENDING ON MODEL OF CHOICE...500MB SW FLOW AND 850MB LLJ BRING INSTABILITY INTO FA FROM WEST TO EAST. WENT WITH A MOSTLY SHRA AND ISO THUNDER FOR WX GRIDS AS SHOWALTERS DO BECOME NEGATIVE AHEAD OF THE SFC TROUGH EXPECTED TO IMPACT THE NORTHERN PLAINS TOWARDS THE END OF THE WEEK. TEMPERATURES ABOVE NORMAL THROUGH THE WEEK CAN BE EXPECTED WITH SOME HUMIDITY POSSIBLE BY WEEKS END. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 101 PM CDT SAT SEP 13 2014 VFR CIGS WITH SOUTHERLY WINDS SWITCHING TO THE WEST THIS EVENING AS A FRONT MOVES ACROSS THE NORTHERN TIER OF THE CONUS. WILL SEE SOME SHRA MOVE ACROSS THE NORTHERN VALLEY AND INTO NW MN IN THE EARLY AFTN...AND WILL MENTION AT GFK AND TVF. NOT AS CONFIDENT AT BJI WHERE SHRA MAY PETER OUT BEFORE MAKING IT THAT FAR EAST...BUT WILL HOLD MID LEVEL CIGS IN THROUGH THE 18Z PD AS WRAP AROUND MOISTURE SHOULD IMPACT BJI THE LONGEST. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...RIDDLE SHORT TERM...EWENS LONG TERM...JK/EWENS AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1247 PM CDT SAT SEP 13 2014 .UPDATE... ISSUED AT 1235 PM CDT SAT SEP 13 2014 COLD FRONT PROGRESSING THROUGH THE REGION EARLY THIS AFTERNOON. SO FAR SHOWERS ARE ONLY VERY WIDELY SCATTERED ACROSS THE NORTH WITH MORE SHOWERS UPSTREAM IN SASK. WILL MAINTAIN SLIGHT CHANCE THROUGH THE AFTERNOON NORTH. ONLY UPDATE WILL BE FOR WINDS...RAISED A BIT WEST TO 20 TO 30 MPH. UPDATE ISSUED AT 845 AM CDT SAT SEP 13 2014 CANCELLED THE FROST ADVISORY. REFINED THE CLOUD COVER BASED ON SATELLITE TRENDS AS HIGH CLOUDS ARE FADING A BIT CENTRAL. UPPED THE WINDS A BIT AFTER THE FRONTAL PASSAGE. UPDATE ISSUED AT 633 AM CDT SAT SEP 13 2014 LATEST SURFACE ANALYSIS SHOWS SURFACE CDFNT OVER WESTERN NORTH DAKOTA WITH STRATOCU DECK DROPPING SOUTH FROM ALBERTA AND WESTERN SASKATCHEWAN INTO NORTH CENTRAL MONTANA. LATEST 10 UTC RAP LOOKS TO BE A LITTLE TOO QUICK IN BRINGING HIGHER 850 MB MOISTURE INTO WESTERN NORTH DAKOTA...BUT BASED ON LATEST SATELLITE AND OBSERVATIONS HAVE BUMPED UP SKY COVER ACROSS THE WEST LATER THIS MORNING AND OVER THE NORTH AND CENTRAL THIS AFTERNOON. NO CHANGES TO POPS AT THIS TIME...KEEPING SLIGHT CHANCE MAINLY NORTH OF THE I94 CORRIDOR...WHICH IS IN AGREEMENT WITH LATEST RAP/HRRR ITERATIONS. CURRENT TEMPERATURES REMAIN IN THE MID 30S ACROSS MOST OF THE FROST ADVISORY AREA...THUS WILL KEEP IT GOING. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 308 AM CDT SAT SEP 13 2014 EARLY MORNING WATER VAPOR IMAGERY SHOWED AN UPPER WAVE MOVING SOUTHEAST ACROSS SOUTHERN SASKATCHEWAN WHICH WAS PUSHING A COLD FRONT TOWARDS THE STATE. THE UPPER WAVE IS EXPECTED TO MOVE QUICKLY ACROSS THE NORTHERN PLAINS TODAY ALONG WITH THE COLD FRONT. THE MAIN QUESTION WILL BE HOW FAR SOUTH TO BRING A CHANCE OF RAIN SHOWERS TODAY AS THE WAVE / COLD FRONT PASS. THERE ARE A WIDE VARIETY OF MODEL SOLUTIONS WITH DIFFERING PLACEMENT...BUT DUE TO THE STRENGTH OF THE WAVE OPTED TO FAVOR THE MODELS WHICH BRING THE RAIN CHANCES FARTHER SOUTH INTO NORTH DAKOTA. IN FACT...AM A BIT CONCERNED WE MAY NOT HAVE TAKEN THE POPS FAR ENOUGH SOUTH IF THE 4.0KM WRF NMM VERIFIES. A POTENTIAL LIMITING FACTOR COULD BE DRY AIR IN THE LOW LEVELS...SO KEPT THE RAIN CHANCES GENERALLY NORTH OF I-94. THE NEXT CONCERN SURROUNDS THE FROST ADVISORY WHICH IS IN PLACE ACROSS ROUGHLY THE SOUTHERN HALF OF THE FORECAST AREA THIS MORNING. PASSING HIGH CLOUDS AHEAD OF THE UPPER WAVE HAVE HELPED TEMPERATURES RISE A FEW DEGREES OVERNIGHT IN SOME LOCATIONS...BUT READINGS IN THE ADVISORY AREA REMAIN IN THE 30S TO LOWER 40S. THE HIGH CLOUDS ARE RATHER THIN ON THEIR SOUTHERN EDGE...AND WITH GFS LAMP GUIDANCE STILL SUPPORTING FALLING TEMPERATURES AT MOST LOCATIONS...WILL KEEP THE ADVISORY IN PLACE. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 308 AM CDT SAT SEP 13 2014 THE LONG TERM PERIOD BEGINNING SUNDAY LOOKS RATHER TRANQUIL THROUGH MID WEEK. PATCHY MORNING FROST CAN NOT BE RULED OUT EARLY SUNDAY AND MONDAY MORNINGS WITH SURFACE HIGH PRESSURE OVER THE AREA AND A NORTHWEST UPPER FLOW KEEPING SEASONABLY COOL AIR OVER THE NORTHERN PLAINS. OTHERWISE IT LOOKS DRY WITH A WARMING TREND THROUGH MIDWEEK. MORNING LOWS IN THE MID 30S TO LOWER 40S...AND DAYTIME HIGHS IN THE UPPER 50S AND 60S SUNDAY AND MONDAY...WILL WARM TO THE MID 40S TO MID 50S FOR LOWS...AND 70S FOR HIGHS BY MID TO LATE WEEK. A PROGRESSIVE UPPER LEVEL TROUGH MOVING ONTO THE WESTERN U.S. COAST ON THURSDAY WILL APPROACH THE NORTHERN PLAINS BY LATE FRIDAY. THERE ARE DIFFERENCES IN THE HANDLING OF THIS WAVE BETWEEN THE GFS AND ECMWF MODELS BUT BOTH BRING INCREASING MOISTURE AND A SMALL CHANCE OF SHOWERS AND ISOLATED THUNDER LATE THURSDAY INTO EARLY FRIDAY...WITH THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS FRIDAY AND FRIDAY NIGHT AND POSSIBLY LINGERING IN THE EAST EARLY SATURDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1235 PM CDT SAT SEP 13 2014 COLD FRONT PROGRESSING THROUGH THE REGION. WHILE VFR CONDITIONS ARE FORECAST THROUGH THE PERIOD...CLOUDS WILL LOWER TO 3 TO 5 THOUSAND AGL AS THE COOLER AIR MOVES IN FROM. SCATTERED SHOWERS EXPECTED ACROSS THE NORTH UNTIL 00Z. TO WIDELY SCATTERED TO INCLUDE IN THE TAF AT THIS TIME. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...WAA SHORT TERM...CK LONG TERM...TWH AVIATION...WAA
AREA FORECAST DISCUSSION
NWS NORMAN OK
1237 PM CDT SAT SEP 13 2014 .DISCUSSION... AVIATION DISCUSSION FOR THE 18Z TAFS IS BELOW. && .AVIATION... GENERALLY HAVE MODERATE TO HIGH CONFIDENCE IN THE TAFS THROUGH 06Z...THEN DECREASING CONFIDENCE AFTERWARDS. THINK ALL SITES WILL BE VFR BY 20Z WITH KOKC...KOUN... AND KSPS AS THE LAST SITES TO HAVE MVFR CEILINGS. REDEVELOPMENT OF VFR/MVFR CEILINGS 1500-5000 FT AGL WILL LIKELY OCCUR AFTER 06Z...MAINLY SOUTHWEST OF KGAG- KOKC-KMLC. HEIGHT OF THESE CEILINGS REMAINS MOST UNCERTAIN. WINDS WILL GENERALLY SHIFT TO THE SOUTHEAST AT ALL SITES BY 01Z. MBS && .PREV DISCUSSION... /ISSUED 1037 AM CDT SAT SEP 13 2014/ DISCUSSION... PERSISTENT CLOUD COVER WILL MAINTAIN RELATIVELY COOL WEATHER INTO THE AFTERNOON OVER MOST OF OKLAHOMA AND NORTH TEXAS. CURRENT SATELLITE TRENDS APPEAR TO SUPPORT THE HRRR MODEL FORECAST OF CLOUD BREAKUP THIS AFTERNOON...EARLIER IN PARTS OF NORTHERN OKLAHOMA...WHERE THERE ARE ALREADY LARGE HOLES IN THE CLOUD COVER. THE FORECAST WAS UPDATED EARLIER THIS MORNING TO ACCOUNT FOR THE LATEST TRENDS AND EXPECTATIONS. PREV DISCUSSION... /ISSUED 638 AM CDT SAT SEP 13 2014/ AVIATION... 13/12Z TAFS...MVFR CIGS WILL BE SEEN AT MOST TERMINALS THROUGH ABOUT 15-17Z...WITH VFR EXPECTED THEREAFTER. NORTHERLY WINDS WILL BECOME SOUTHEAST LATE TODAY AND INCREASE IN SPEED AFTER THIS FORECAST PERIOD. LOW CLOUDS WILL BEGIN TO INCREASE TOWARD END OF FORECAST PERIOD BUT WILL LEAVE FCST VFR FOR NOW. PREV DISCUSSION... /ISSUED 410 AM CDT SAT SEP 13 2014/ DISCUSSION... CLEARING...AT LEAST PARTIALLY...EXPECTED THE REGION TODAY. THE GREATEST AMOUNT OF CLEARING EXPECTED OVER THE NORTH-CENTRAL PORTIONS OF OKLAHOMA. SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS MAY ACTUALLY SEE MORE CLOUDS THAN SUN TODAY. NO PRECIPITATION EXPECTED TODAY OR TONIGHT. RETURN TO SOUTHERLY FLOW TONIGHT AND SUNDAY WILL ALLOW MOISTURE TO WORK ITS WAY BACK OVER REGION AND ALLOW CLOUDS TO FILL BACK IN ON SUNDAY. RAIN CHANCES RETURN TO FORECAST SUNDAY NIGHT AS NEXT UPPER LEVEL TROUGH AND ASSOCIATED COLD FRONT MOVE OVER SOUTHERN PLAINS. MOST OF THE PRECIP EXPECTED NEAR THE FRONT AS IT PROGRESSES SLOWLY SOUTH OVER OKLAHOMA TO THE RED RIVER VALLEY MONDAY AFTERNOON AND MONDAY NIGHT. FRONT LIFTS BACK NORTH TUESDAY INTO WEDNESDAY...AND WITH DEVELOPMENT OF NWLY FLOW...WILL BE A FOCUS FOR SHOWERS AND STORMS WEDNESDAY INTO THURSDAY MAINLY OVER THE EASTERN HALF OF OKLAHOMA. CONFIDENCE NOT QUITE AS HIGH SO POPS WILL REMAIN ON THE LOW SIDE OF GUIDANCE. FAIR AMOUNT OF DISPARITY IN THE MEDIUM RANGE MODELS FOR FRIDAY AND NEXT WEEKEND...WITH ECM CURRENTLY SHOWING PROLONGED PERIOD OF RAIN AND GFS A MORE PROGRESSIVE AND DRY PATTERN. TRENDS WILL NEED TO BE MONITORED BEFORE POPS ARE INTRODUCED AT END OF FORECAST PERIOD. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 66 57 80 66 / 0 0 10 20 HOBART OK 70 55 80 65 / 0 0 10 20 WICHITA FALLS TX 67 59 81 68 / 10 0 10 10 GAGE OK 71 53 82 63 / 0 0 10 10 PONCA CITY OK 67 53 79 65 / 0 0 10 20 DURANT OK 68 60 78 66 / 10 0 10 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 23/17/17