Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/06/12


AREA FORECAST DISCUSSION
NWS PUEBLO CO
1129 AM MDT SAT AUG 4 2012 .AVIATION...SMALL PATCH OF MVFR STRATUS NEAR KCOS AS OF 17Z WILL DISSIPATE OVER THE NEXT HOUR AND WON`T INCLUDE IN THE NEW 18Z TAF. ISOLATED TO SCATTERED -TSRA WILL DEVELOP ACROSS THE MOUNTAINS THIS AFTERNOON...THOUGH STORMS SHOULD DISSIPATE AS THEY MOVE OFF THE MTNS AND WILL LIKELY NOT IMPACT KCOS AND KPUB...AS MOISTURE AND INSTABILITY ON THE PLAINS IS LIMITED. SLIGHTLY BETTER ODDS OF A STORM AT KALS...THOUGH CHANCE IS STILL TOO LOW TO MENTION IN THE TAF AT THIS POINT. TSRA AND CLOUD COVER SHOULD DECREASE QUICKLY AFTER SUNSET WITH VFR CONDITIONS AND LIGHT WINDS EXPECTED THROUGH THE NIGHT. && .PREV DISCUSSION... /ISSUED 408 AM MDT SAT AUG 4 2012/ SHORT TERM... (TODAY AND TONIGHT) COLD FRONT CURRENTLY RACING THROUGH SOUTHEAST CO AND SHOULD REACH THE SOUTHERN BORDER BY 12-13Z. WIND GUSTS BEHIND THE FRONT HAVE BEEN IN THE 40-45 KT RANGE SO FAR THIS MORNING ACROSS PORTIONS OF SOUTHERN EL PASO AND PUEBLO COUNTIES. HRRR AND LOCAL 4KM WRF SHOW POTENTIAL FOR SOME ISOLATED SHOWERS TO DEVELOP BEHIND THE FRONT ACROSS THE SOUTHEAST PLAINS EARLY THIS MORNING AS IT ENCOUNTERS HIGHER DEW POINTS ACROSS THE FAR SOUTHEAST PLAINS. WILL MAINTAIN SOME 20 POPS THROUGH 15Z FOR THE FAR SOUTHERN AND EASTERN PORTIONS OF THE AREA. OTHERWISE...REMAINDER OF THE AREA SHOULD REMAIN DRY THROUGH THE EARLY MORNING HOURS. NAM ALSO DEVELOPS SOME MVFR STRATUS EARLY THIS MORNING ALONG THE CREST OF THE PALMER DIVIDE. GUSTY NORTH WINDS WILL CONTINUE THROUGH THE MORNING BEFORE SWINGING AROUND FROM THE EAST TO SOUTHEAST DURING THE AFTERNOON ACROSS THE PLAINS. DEW POINTS BEHIND THE FRONT DROP INTO THE 40S BY AFTERNOON...AND MODEL SOUNDINGS SHOW A STOUT CAPPING INVERSION WHICH SHOULD HINDER AFTERNOON THUNDERSTORM DEVELOPMENT ACROSS THE PLAINS. MEANWHILE...MONSOON PLUME HAS BEEN SHUNTED EVEN FARTHER SOUTH TODAY...WITH PRECIP WATERS ABOVE 100% OF NORMAL NOW PUSHED TO ALONG THE SRN CO BORDER AND INTO NEW MEXICO. STILL ENOUGH MOISTURE PRESENT FOR ISOLATED TO SCATTERED THUNDERSTORMS ACROSS THE SOUTHERN MTS TODAY...THOUGH GREATEST COVERAGE SHOULD BE NEAR THE NM BORDER. HAVE DECREASED POPS FARTHER NORTH WHERE SOUNDINGS LOOK QUITE DRY. LATEST MODELS ARE TRENDING PRECIPITATION SOUTHWARD TO ALONG THE FRONTAL BOUNDARY ACROSS NORTHEAST NEW MEXICO...AND HAVE CUT BACK POPS TO ISOLATED ALONG THE NRN SLOPES OF THE RATON RIDGE. GUIDANCE TEMPERATURES TODAY STILL SHOW QUITE A DISCREPANCY...WITH MAV RUNNING AROUND 5 TO 10 DEGREES COOLER THAN MET ACROSS THE PLAINS. HAVE GENERALLY SPLIT THE DIFFERENCE FOR NOW. MTN AREAS SHOULD SEE TEMPS SIMILAR TO A DEGREE OR TWO COOLER THAN THOSE OF YESTERDAY. TONIGHT...CONVECTION SHOULD DIMINISH QUICKLY THIS EVENING WITH LOSS OF HEATING. WILL MAINTAIN SOME ISOLATED POPS ACROSS THE SRN MTS UNTIL 06Z...THEN REMOVE POPS THERE-AFTER. MIN TEMPS TONIGHT SHOULD BE COOLER ACROSS THE PLAINS AND HAVE CUT THEM BACK A COUPLE DEGREES. -KT LONG TERM... (SUNDAY THROUGH SATURDAY) THE EXTENDED FORECAST WILL BE DOMINATED BY HIGH PRESSURE OVER THE FOUR CORNERS REGION WITH VERY HOT CONDITIONS FOR THE LOWER ELEVATIONS AND MOUNTAIN THUNDERSTORMS. HIGH PRESSURE BEGINS TO BUILD NORTHWARD SUNDAY MORNING AS AN UPPER LEVEL TROUGH MOVES EAST ACROSS THE GREAT LAKES. A WEAK DISTURBANCE CAUGHT UNDER THE BUILDING HIGH WILL DRIFT NEAR THE COLORADO NEW MEXICO BORDER AND HELP GENERATE SHOWER AND THUNDERSTORM ACTIVITY...ESPECIALLY OVER THE SAN JUAN AND SOUTHERN SANGRE DE CRISTO RANGES. MODELS KEEP THIS ACTIVITY GOING THROUGH SUNDAY NIGHT INTO MONDAY MORNING. HIGH PRESSURE CONTINUES TO BUILD ACROSS THE REGION ON MONDAY WITH AFTERNOON THUNDERSTORMS DEVELOPING OVER THE MOUNTAINS. FLOW ALOFT WILL REMAIN NORTHWESTERLY AROUND THE STRENGTHENING HIGH WHICH WILL HELP PUSH CONVECTION INTO THE I-25 CORRIDOR. THIS ACTIVITY IS FORECAST TO DIMINISH THROUGH THE EVENING HOURS. TEMPERATURES ON SUNDAY WILL START TO WARM WITH UPPER 80S TO LOWER 90S FOR THE PLAINS. BY MONDAY...HIGHS WILL BE PUSHING INTO THE UPPER 90S TO LOWER 100S FOR THE PLAINS. TUESDAY THROUGH SATURDAY...HIGH PRESSURE WILL ANCHOR ITSELF OVER THE FOUR CORNERS AREA AND DOMINATE THE WEATHER. THIS WILL HELP KEEP TEMPERATURES WARM THROUGH THE EXTENDED WITH UPPER 90S TO LOWER 100S EXPECTED FOR THE PLAINS. WITH THE MONSOON MOISTURE TAP WELL TO THE WEST AND DRIER AIR ACROSS COLORADO...THUNDERSTORM COVERAGE IS FORECAST TO BE MINIMAL AND DIURNALLY DRIVEN. WITH WEAK FLOW ALOFT...ANY THUNDERSTORMS THAT DO DEVELOP WILL REMAIN ANCHORED TO THE MOUNTAINS. 88 AVIATION... MVFR STRATUS WILL DEVELOP ALONG THE CREST OF THE PALMER DIVIDE AND NORTH SIDE OF THE RATON RIDGE THIS MORNING. NORTH WINDS GUSTING TO 30-40 KTS WILL CONTINUE AT KPUB AND KCOS THROUGH 12-15Z BEFORE WINDS DECREASE AND SWING AROUND FROM THE EAST TO SOUTHEAST BY THE AFTERNOON. STRATUS SHOULD DISSIPATE BY LATE MORNING...AND STAY PREDOMINANTLY TO THE NORTH OF THE KCOS TERMINAL. ISOLATED TO SCATTERED -TSRA WILL DEVELOP ACROSS THE MOUNTAINS DURING THE AFTERNOON...THOUGH SHOULD DISSIPATE AS THEY MOVE OFF THE MTS AND SHOULD NOT IMPACT KCOS AND KPUB. KALS WILL HAVE A SLIGHTLY BETTER CHANCE OF SEEING A PASSING -TSRA IN THE AFTERNOON...THOUGH ODDS TOO LOW AT THIS POINT TO INCLUDE IN TAF AS LOW LEVEL MOISTURE SHOULD BE LESS TODAY. -TSRA AND CLOUD COVER SHOULD DECREASE QUICKLY AFTER SUNSET WITH VFR CONDITIONS AND LIGHT WINDS EXPECTED THROUGH THE NIGHT. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 10/27
AREA FORECAST DISCUSSION
NWS PUEBLO CO
408 AM MDT SAT AUG 4 2012 .SHORT TERM... (TODAY AND TONIGHT) COLD FRONT CURRENTLY RACING THROUGH SOUTHEAST CO AND SHOULD REACH THE SOUTHERN BORDER BY 12-13Z. WIND GUSTS BEHIND THE FRONT HAVE BEEN IN THE 40-45 KT RANGE SO FAR THIS MORNING ACROSS PORTIONS OF SOUTHERN EL PASO AND PUEBLO COUNTIES. HRRR AND LOCAL 4KM WRF SHOW POTENTIAL FOR SOME ISOLATED SHOWERS TO DEVELOP BEHIND THE FRONT ACROSS THE SOUTHEAST PLAINS EARLY THIS MORNING AS IT ENCOUNTERS HIGHER DEW POINTS ACROSS THE FAR SOUTHEAST PLAINS. WILL MAINTAIN SOME 20 POPS THROUGH 15Z FOR THE FAR SOUTHERN AND EASTERN PORTIONS OF THE AREA. OTHERWISE...REMAINDER OF THE AREA SHOULD REMAIN DRY THROUGH THE EARLY MORNING HOURS. NAM ALSO DEVELOPS SOME MVFR STRATUS EARLY THIS MORNING ALONG THE CREST OF THE PALMER DIVIDE. GUSTY NORTH WINDS WILL CONTINUE THROUGH THE MORNING BEFORE SWINGING AROUND FROM THE EAST TO SOUTHEAST DURING THE AFTERNOON ACROSS THE PLAINS. DEW POINTS BEHIND THE FRONT DROP INTO THE 40S BY AFTERNOON...AND MODEL SOUNDINGS SHOW A STOUT CAPPING INVERSION WHICH SHOULD HINDER AFTERNOON THUNDERSTORM DEVELOPMENT ACROSS THE PLAINS. MEANWHILE...MONSOON PLUME HAS BEEN SHUNTED EVEN FARTHER SOUTH TODAY...WITH PRECIP WATERS ABOVE 100% OF NORMAL NOW PUSHED TO ALONG THE SRN CO BORDER AND INTO NEW MEXICO. STILL ENOUGH MOISTURE PRESENT FOR ISOLATED TO SCATTERED THUNDERSTORMS ACROSS THE SOUTHERN MTS TODAY...THOUGH GREATEST COVERAGE SHOULD BE NEAR THE NM BORDER. HAVE DECREASED POPS FARTHER NORTH WHERE SOUNDINGS LOOK QUITE DRY. LATEST MODELS ARE TRENDING PRECIPITATION SOUTHWARD TO ALONG THE FRONTAL BOUNDARY ACROSS NORTHEAST NEW MEXICO...AND HAVE CUT BACK POPS TO ISOLATED ALONG THE NRN SLOPES OF THE RATON RIDGE. GUIDANCE TEMPERATURES TODAY STILL SHOW QUITE A DISCREPANCY...WITH MAV RUNNING AROUND 5 TO 10 DEGREES COOLER THAN MET ACROSS THE PLAINS. HAVE GENERALLY SPLIT THE DIFFERENCE FOR NOW. MTN AREAS SHOULD SEE TEMPS SIMILAR TO A DEGREE OR TWO COOLER THAN THOSE OF YESTERDAY. TONIGHT...CONVECTION SHOULD DIMINISH QUICKLY THIS EVENING WITH LOSS OF HEATING. WILL MAINTAIN SOME ISOLATED POPS ACROSS THE SRN MTS UNTIL 06Z...THEN REMOVE POPS THERE-AFTER. MIN TEMPS TONIGHT SHOULD BE COOLER ACROSS THE PLAINS AND HAVE CUT THEM BACK A COUPLE DEGREES. -KT .LONG TERM... (SUNDAY THROUGH SATURDAY) THE EXTENDED FORECAST WILL BE DOMINATED BY HIGH PRESSURE OVER THE FOUR CORNERS REGION WITH VERY HOT CONDITIONS FOR THE LOWER ELEVATIONS AND MOUNTAIN THUNDERSTORMS. HIGH PRESSURE BEGINS TO BUILD NORTHWARD SUNDAY MORNING AS AN UPPER LEVEL TROUGH MOVES EAST ACROSS THE GREAT LAKES. A WEAK DISTURBANCE CAUGHT UNDER THE BUILDING HIGH WILL DRIFT NEAR THE COLORADO NEW MEXICO BORDER AND HELP GENERATE SHOWER AND THUNDERSTORM ACTIVITY...ESPECIALLY OVER THE SAN JUAN AND SOUTHERN SANGRE DE CRISTO RANGES. MODELS KEEP THIS ACTIVITY GOING THROUGH SUNDAY NIGHT INTO MONDAY MORNING. HIGH PRESSURE CONTINUES TO BUILD ACROSS THE REGION ON MONDAY WITH AFTERNOON THUNDERSTORMS DEVELOPING OVER THE MOUNTAINS. FLOW ALOFT WILL REMAIN NORTHWESTERLY AROUND THE STRENGTHENING HIGH WHICH WILL HELP PUSH CONVECTION INTO THE I-25 CORRIDOR. THIS ACTIVITY IS FORECAST TO DIMINISH THROUGH THE EVENING HOURS. TEMPERATURES ON SUNDAY WILL START TO WARM WITH UPPER 80S TO LOWER 90S FOR THE PLAINS. BY MONDAY...HIGHS WILL BE PUSHING INTO THE UPPER 90S TO LOWER 100S FOR THE PLAINS. TUESDAY THROUGH SATURDAY...HIGH PRESSURE WILL ANCHOR ITSELF OVER THE FOUR CORNERS AREA AND DOMINATE THE WEATHER. THIS WILL HELP KEEP TEMPERATURES WARM THROUGH THE EXTENDED WITH UPPER 90S TO LOWER 100S EXPECTED FOR THE PLAINS. WITH THE MONSOON MOISTURE TAP WELL TO THE WEST AND DRIER AIR ACROSS COLORADO...THUNDERSTORM COVERAGE IS FORECAST TO BE MINIMAL AND DIURNALLY DRIVEN. WITH WEAK FLOW ALOFT...ANY THUNDERSTORMS THAT DO DEVELOP WILL REMAIN ANCHORED TO THE MOUNTAINS. MOZLEY && .AVIATION... MVFR STRATUS WILL DEVELOP ALONG THE CREST OF THE PALMER DIVIDE AND NORTH SIDE OF THE RATON RIDGE THIS MORNING. NORTH WINDS GUSTING TO 30-40 KTS WILL CONTINUE AT KPUB AND KCOS THROUGH 12-15Z BEFORE WINDS DECREASE AND SWING AROUND FROM THE EAST TO SOUTHEAST BY THE AFTERNOON. STRATUS SHOULD DISSIPATE BY LATE MORNING...AND STAY PREDOMINANTLY TO THE NORTH OF THE KCOS TERMINAL. ISOLATED TO SCATTERED -TSRA WILL DEVELOP ACROSS THE MOUNTAINS DURING THE AFTERNOON...THOUGH SHOULD DISSIPATE AS THEY MOVE OFF THE MTS AND SHOULD NOT IMPACT KCOS AND KPUB. KALS WILL HAVE A SLIGHTLY BETTER CHANCE OF SEEING A PASSING -TSRA IN THE AFTERNOON...THOUGH ODDS TOO LOW AT THIS POINT TO INCLUDE IN TAF AS LOW LEVEL MOISTURE SHOULD BE LESS TODAY. -TSRA AND CLOUD COVER SHOULD DECREASE QUICKLY AFTER SUNSET WITH VFR CONDITIONS AND LIGHT WINDS EXPECTED THROUGH THE NIGHT. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 31/88
AREA FORECAST DISCUSSION
NWS MIAMI FL
154 PM EDT SAT AUG 4 2012 .SHORT TERM...(TONIGHT-MONDAY NIGHT) THE LATEST SURFACE ANALYSIS SHOWED A TROUGH EXTENDING SOUTH OF A WEAK LOW PRESSURE AREA CENTERED ALONG IT NORTHWEST OF THE BAHAMAS OR EAST SOUTHEAST OF FT PIERCE. LIGHT WNW FLOW ACROSS THE LOCAL AREA TO ITS SOUTHWEST COMBINED WITH THE ATLANTIC SEA BREEZE HAS ALREADY LED TO A FEW SHOWERS DEVELOPING ALONG IT OVER PALM BEACH COUNTY NEAR THE COAST AND FARTHER SOUTH ALONG THE EAST COAST AREAS. LOCAL WRF AND HRRR MODEL REFLECTIVITIES SEEM TO BE INITIALIZING WELL WITH THIS PATTERN AND GENERALLY INDICATE THIS ACTIVITY INCREASING IN COVERAGE THROUGH THE COURSE OF THE AFTERNOON TODAY AS THE ATL SEA BREEZE CONTINUES TO MAKE ITS PUSH INLAND. THIS COMBINED WITH THE ACTIVITY FROM YESTERDAY COULD GENERATE MORE FLOODING CONCERNS DEPENDING ON WHERE THE HEAVIEST ACTIVITY BECOMES CONCENTRATED AS THE DAY PROGRESSES. THE MORNING UPPER AIR SOUNDING AT MIAMI ALONG WITH THE LATEST SATELLITE DERIVED 500 MB TEMPERATURES INDICATE A MORE STABLE ENVIRONMENT COMPARED TO YESTERDAY AND WITH THE BEST INSTABILITY OR COOLER MID /UPPER-LEVEL AIR NOW TO THE WEST OF THE FL PENINSULA CLOSER TO THE BROAD UPPER LOW CENTER OVER THE GULF OF MEXICO. THEREFORE...THE MAIN IMPACTS FROM ANY STRONG STORMS THAT DO DEVELOP SHOULD REMAIN SUB-SEVERE AND MAINLY ASSOCIATED WITH STRONG WIND GUSTS UP TO 50 MPH. THE LATEST NUMERICAL MODEL GUIDANCE HAS INITIALIZED WELL WITH THIS SURFACE TROUGH AND LOW JUST EAST OF THE LOCAL AREA AND GENERALLY INDICATES THIS FEATURE CONTINUING WESTWARD OVER SOUTH FLORIDA THROUGH TONIGHT...THEN WEST OF THE FL PENINSULA SUNDAY THROUGH MONDAY. IN ITS WAKE...MOIST SOUTHEAST FLOW WILL BE EXPECTED AS THE AFOREMENTIONED SURFACE TROUGH/UPPER LOW CONTINUES WEST AND AWAY FROM THE FL PENINSULA AND ERNESTO CONTINUES ITS WESTWARD TRACK ACROSS THE CARIBBEAN SEA AND PASSES THE LOCAL AREA TO THE SOUTH SUNDAY THROUGH MONDAY NIGHT. MODERATE EAST AND SOUTHEAST FLOW THROUGH THE LOW LEVELS DUE TO A SLIGHTLY ENHANCED GRADIENT BETWEEN ERNESTO TO THE SOUTH AND THE SUBTROPICAL RIDGE TO THE NORTH COMBINED WITH PRECIPITABLE WATER VALUES AROUND THE TWO INCH MARK WILL KEEP THE RAIN CHANCES IN THE FORECAST THROUGH THE PERIOD. .LONG TERM (TUESDAY-FRIDAY)... ATLANTIC HIGH PRESSURE WILL BUILD INTO SOUTH FL BEGINNING TUE AND LASTING THROUGH THE WORK WEEK WITH DRIER AIR MOVING IN FROM THE EAST. PWATS LOWER TO AROUND 1.5 INCHES WED-THU...WITH EVEN A LITTLE BIT OF HAZE FROM SAHARAN DUST POSSIBLY MOVING IN MID WEEK. WITH THE EASTERLY FLOW IN PLACE...SHOWERS/TSTMS THAT DEVELOP DURING THIS TIME SHOULD HAVE THE BEST CHANCE OF FORMING OVER THE INLAND AND WESTERN LOCATIONS EACH AFTERNOON. MOISTURE BEGINS TO INCREASE ACROSS THE AREA BY FRI. && .MARINE... A TROUGH EXTENDING SOUTH OF A WEAK LOW PRESSURE AREA CENTERED NORTH OF THE BAHAMAS OR EAST SOUTHEAST OF CAPE CANAVERAL IS FORECAST TO TRACK WEST AND NORTHWEST ACROSS THE FLORIDA PENINSULA THROUGH TONIGHT. SCATTERED SHOWER AND STORMS ASSOCIATED WITH THIS FEATURE WILL LEAD TO PERIODS WITH REDUCED VISIBILITIES ALONG WITH LOCALLY HIGHER WINDS AND SEAS...ESPECIALLY ACROSS THE ATLANTIC WATERS. SUNDAY THROUGH THE MID WEEK PERIOD...MODERATE EASTERLY WINDS AND SEAS WILL BE ANTICIPATED AS TROPICAL STORM ERNESTO PASSES SOUTH OF THE MARINE AREA ACROSS THE CARIBBEAN SEA. FOR THE LATEST INFORMATION REGARDING ERNESTO...REFER TO THE LATEST FORECASTS AND ADVISORIES ISSUED BY THE NATIONAL HURRICANE CENTER. && .FIRE WEATHER... NO CONCERNS THROUGH THE WEEKEND AND INTO THE UPCOMING WEEK AS PLENTY OF MOISTURE AND RAIN CHANCES REMAIN IN THE FORECAST.SOME DRIER AIR WITH MODERATE EASTERLY FLOW APPEARS POSSIBLE THROUGH THE MID-WEEK PERIOD. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 77 88 79 88 / 50 60 40 60 FORT LAUDERDALE 79 90 80 89 / 50 60 40 60 MIAMI 78 89 79 89 / 50 60 40 60 NAPLES 76 92 76 90 / 40 50 40 60 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...85/AG AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS MIAMI FL
147 PM EDT SAT AUG 4 2012 .AVIATION... SATELLITE AND RADAR SHOW AN AREA OF LOW PRESSURE OFF THE COAST OF CENTRAL FLORIDA AND MOVING TO THE NORTHWEST. SHOWERS AND THUNDERSTORMS REMAINED OVER THE LOCAL WATERS AND BAHAMAS. THE SEA BREEZE BOUNDARIES WERE BEGINNING TO MOVE INLAND...WITH ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPING ALONG IT. EXPECT ACTIVITY TO BECOME MORE NUMEROUS OVER THE NEXT COUPLE OF HOURS...BUT MOST OF THE ACTIVITY MAY BE JUST TO THE WEST OF THE EAST COAST TAF SITES. SO WILL KEEP VCTS AT THE TAF SITES. KEPT VCSH TONIGHT ACROSS THE REGION AS THE AREA OF LOW PRESSURE MOVES ACROSS FLORIDA TONIGHT THROUGH SUNDAY. AT THIS TIME DID NOT CARRY THUNDERSTORMS OVERNIGHT...BUT THIS WILL NEED TO BE MONITORED. EXPECT NUMEROUS SHOWERS AND THUNDERSTORMS TO REDEVELOP ACROSS THE REGION ON SUNDAY...PUSHING TOWARDS KAPF IN THE AFTERNOON. MOSTLY VFR CONDITIONS WILL CONTINUE...BUT MVFR CIG/VIS ARE POSSIBLE IN AND AROUND SHOWERS AND THUNDERSTORMS. EAST TO SOUTHEAST WINDS AROUND 10 KNOTS ARE EXPECTED AT THE EAST COAST TAF SITES THIS AFTERNOON...WITH A WEST TO NORTHWEST WIND AT NAPLES. LIGHT EASTERLY FLOW IS EXPECTED OVERNIGHT...WITH THE EAST COAST SEA BREEZE PUSHING BY MID/LATE MORNING. && .PREV DISCUSSION... /ISSUED 724 AM EDT SAT AUG 4 2012/ AVIATION... A TROPICAL WAVE BETWEEN THE BAHAMAS AND MAINLAND...WHICH EXTENDS SW OVER N CUBA...WILL SLOWLY MOVE W THROUGH THE PERIOD. THIS FEATURE WILL SLOWLY MOVE OVER THE SE FLA COAST THIS MORNING AND WILL MOVE ACROSS S FLA THROUGH THE DAY. SCATTERED SHRA WITH ISOLD TSRA AT THIS TIME WELL E IN THE ATLC BUT EXPECT SHRA TO DEVELOP BY LATE MORNING AND POSSIBLE TSRA AS EARLY AS 16Z ALONG THE E COAST. WILL HAVE VCSH IN E COAST TERMINALS INITIALLY BUT POSSIBLE TSRA BY 16Z. ANY TSRA THAT DEVELOP WILL MOVE SLOWLY SO HEAVY RA AND POSSIBLE MVFR CIG/VSBY WILL BE POSSIBLE. MODEL GUIDANCE AT THIS TIME DOES NOT INDICATE MVFR CIG/VSBY AND MODELS PROJECT THE BULK OF THE SHRA/TSRA TO THE E OF THE WAVE MOVING N ALONG THE FLA E COAST. HEATING OF THE DAY WILL BE THE MAIN INPUT TO PRECIPITATION. SFC WINDS ENE < 10 KNOTS BECOMING ESE 10 TO 15 KNOTS AS THE WAVE MOVES PAST ANY ONE TERMINAL LATER TODAY. PREV DISCUSSION... /ISSUED 358 AM EDT SAT AUG 4 2012/ .LOCALLY HEAVY RAINFALL POSSIBLE TODAY... .MODERATE RISK OF RIP CURRENTS ATLANTIC BEACHES... DISCUSSION...TROPICAL DISTURBANCE OVER THE BAHAMAS HAS A LOW PROBABILITY OF DEVELOPING PER NHC...AND OUR MAIN CONCERN IS THE POTENTIAL FOR LOCALLY HEAVY RAINFALL...BUT THEN PERHAPS NOT MUCH? A CHALLENGING FORECAST INDEED. MODEL CONSENSUS IS FOR THIS AREA OF DISTURBED WEATHER OVER THE BAHAMAS, ASSOCIATED WITH A BROAD TROUGH, TO MOVE NORTHWEST AND ACROSS SOUTH FLORIDA THROUGH TONIGHT...BUT MODELS SHOWS THE BULK OF THE HEAVIER RAINFALL CONCENTRATING OVER THE LOCAL ATLANTIC WATERS. HOWEVER, SHOWERS ARE NOW DEVELOPING OVER THE ATLANTIC, ESPECIALLY EAST OF THE UPPER KEYS. FORECAST SOUNDINGS SHOW A MOIST AND UNSTABLE PROFILE WITH NO CAPPING...AND WITH PLENTY OF MORNING SUNSHINE/HEATING AND DEVELOPING INSTABILITY, WILL MAINTAIN THE INHERITED 70% EAST TO 50% GULF COAST. INTERESTING THAT THE HRRR IS IN LINE WITH THE GFS/ECMWF SHOWING MAX QPF OFFSHORE. STILL BELIEVE MOST AREAS WILL SEE RAIN ACROSS THE EAST COAST METRO (SO MAINTAINED THE HIGH POPS), DURATION AND AMOUNT IS OF HIGH UNCERTAINTY. AS THIS TROUGH PASSES SOUTH FL TO THE NW TONIGHT, AN INCREASING MOIST SOUTHEASTERLY WIND FLOW WILL DEVELOP SUN-MON. THIS IS EXPECTED TO LEAD TO CONTINUED UNSETTLED WEATHER CONDITIONS WITH BOUTS OF NUMEROUS SHOWERS/TSTORMS FOCUSED IN THE AFTERNOON ALL AREAS (FAST EAST TO WEST MOVEMENT) AND ALONG THE ATLANTIC COAST AT NIGHT. THE MAIN CONCERN IS FOR POTENTIAL LOCALIZED HEAVY RAINFALL ESPECIALLY THIS AFTERNOON AS FCST SOUNDINGS SHOW LITTLE STORM MOTION...AND ANTECEDENT HEAVY RAINS FROM YESTERDAY. STORM MOTION INCREASES SUN-MON. AT THIS TIME, THE CONCERN IS FOR LOCALIZED HEAVIER RAIN AMOUNTS OF 3+" TODAY, WHICH COULD LEAD TO ISOLATED STREET FLOODING...SIMILAR TO WHAT OCCURRED YESTERDAY WHERE HERE AT THE OFFICE WE PICKED UP 4.03" OF RAIN...BRINGING OUR YEARLY TOTAL TO 60.49"! STREET FLOODING COULD OCCUR QUICKER THAN NORMAL IF HEAVY RAINS DEVELOP OVER AREAS WHICH RECEIVED HEAVY RAINFALL YESTERDAY. TS ERNESTO WILL PASS WELL SOUTH OF THE AREA OVER THE CARIB ON MONDAY. ATLANTIC HIGH PRESSURE WILL BUILD INTO SOUTH FL BEGINNING TUE AND LASTING THROUGH THE WORK WEEK WITH DRIER AIR MOVING IN FROM THE EAST. PWATS LOWER TO AROUND 1.5 INCHES WED-THU...WITH EVEN A LITTLE BIT OF HAZE FROM SAHARAN DUST POSSIBLY MOVING IN MID WEEK. SO THE FORECAST TREND IS WET THROUGH MONDAY THEN LOWERING RAIN CHANCES TUE AND BEYOND WITH TSTORMS FOCUSING OVER THE INTERIOR EACH AFTERNOON. MOISTURE BEGINS TO INCREASE BY FRI. MARINE...WINDS WILL BE ON THE INCREASE, ESPECIALLY SUN-MON WITH SEAS INCREASING INTO THE 3-5 FT RANGE. HOWEVER, NO HIGHLIGHTS ARE NEEDED AT THIS TIME. FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN TYPICALLY HIGH. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 88 78 89 79 / 70 50 60 50 FORT LAUDERDALE 88 80 89 79 / 70 50 60 50 MIAMI 89 78 89 79 / 70 50 60 50 NAPLES 91 76 92 77 / 50 30 50 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...85/AG AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS MIAMI FL
724 AM EDT SAT AUG 4 2012 .AVIATION... A TROPICAL WAVE BETWEEN THE BAHAMAS AND MAINLAND...WHICH EXTENDS SW OVER N CUBA...WILL SLOWLY MOVE W THROUGH THE PERIOD. THIS FEATURE WILL SLOWLY MOVE OVER THE SE FLA COAST THIS MORNING AND WILL MOVE ACROSS S FLA THROUGH THE DAY. SCATTERED SHRA WITH ISOLD TSRA AT THIS TIME WELL E IN THE ATLC BUT EXPECT SHRA TO DEVELOP BY LATE MORNING AND POSSIBLE TSRA AS EARLY AS 16Z ALONG THE E COAST. WILL HAVE VCSH IN E COAST TERMINALS INITIALLY BUT POSSIBLE TSRA BY 16Z. ANY TSRA THAT DEVELOP WILL MOVE SLOWLY SO HEAVY RA AND POSSIBLE MVFR CIG/VSBY WILL BE POSSIBLE. MODEL GUIDANCE AT THIS TIME DOES NOT INDICATE MVFR CIG/VSBY AND MODELS PROJECT THE BULK OF THE SHRA/TSRA TO THE E OF THE WAVE MOVING N ALONG THE FLA E COAST. HEATING OF THE DAY WILL BE THE MAIN INPUT TO PRECIPITATION. SFC WINDS ENE < 10 KNOTS BECOMING ESE 10 TO 15 KNOTS AS THE WAVE MOVES PAST ANY ONE TERMINAL LATER TODAY. && .PREV DISCUSSION... /ISSUED 358 AM EDT SAT AUG 4 2012/ ..LOCALLY HEAVY RAINFALL POSSIBLE TODAY... ..MODERATE RISK OF RIP CURRENTS ATLANTIC BEACHES... DISCUSSION...TROPICAL DISTURBANCE OVER THE BAHAMAS HAS A LOW PROBABILITY OF DEVELOPING PER NHC...AND OUR MAIN CONCERN IS THE POTENTIAL FOR LOCALLY HEAVY RAINFALL...BUT THEN PERHAPS NOT MUCH? A CHALLENGING FORECAST INDEED. MODEL CONSENSUS IS FOR THIS AREA OF DISTURBED WEATHER OVER THE BAHAMAS, ASSOCIATED WITH A BROAD TROUGH, TO MOVE NORTHWEST AND ACROSS SOUTH FLORIDA THROUGH TONIGHT...BUT MODELS SHOWS THE BULK OF THE HEAVIER RAINFALL CONCENTRATING OVER THE LOCAL ATLANTIC WATERS. HOWEVER, SHOWERS ARE NOW DEVELOPING OVER THE ATLANTIC, ESPECIALLY EAST OF THE UPPER KEYS. FORECAST SOUNDINGS SHOW A MOIST AND UNSTABLE PROFILE WITH NO CAPPING...AND WITH PLENTY OF MORNING SUNSHINE/HEATING AND DEVELOPING INSTABILITY, WILL MAINTAIN THE INHERITED 70% EAST TO 50% GULF COAST. INTERESTING THAT THE HRRR IS IN LINE WITH THE GFS/ECMWF SHOWING MAX QPF OFFSHORE. STILL BELIEVE MOST AREAS WILL SEE RAIN ACROSS THE EAST COAST METRO (SO MAINTAINED THE HIGH POPS), DURATION AND AMOUNT IS OF HIGH UNCERTAINTY. AS THIS TROUGH PASSES SOUTH FL TO THE NW TONIGHT, AN INCREASING MOIST SOUTHEASTERLY WIND FLOW WILL DEVELOP SUN-MON. THIS IS EXPECTED TO LEAD TO CONTINUED UNSETTLED WEATHER CONDITIONS WITH BOUTS OF NUMEROUS SHOWERS/TSTORMS FOCUSED IN THE AFTERNOON ALL AREAS (FAST EAST TO WEST MOVEMENT) AND ALONG THE ATLANTIC COAST AT NIGHT. THE MAIN CONCERN IS FOR POTENTIAL LOCALIZED HEAVY RAINFALL ESPECIALLY THIS AFTERNOON AS FCST SOUNDINGS SHOW LITTLE STORM MOTION...AND ANTECEDENT HEAVY RAINS FROM YESTERDAY. STORM MOTION INCREASES SUN-MON. AT THIS TIME, THE CONCERN IS FOR LOCALIZED HEAVIER RAIN AMOUNTS OF 3+" TODAY, WHICH COULD LEAD TO ISOLATED STREET FLOODING...SIMILAR TO WHAT OCCURRED YESTERDAY WHERE HERE AT THE OFFICE WE PICKED UP 4.03" OF RAIN...BRINGING OUR YEARLY TOTAL TO 60.49"! STREET FLOODING COULD OCCUR QUICKER THAN NORMAL IF HEAVY RAINS DEVELOP OVER AREAS WHICH RECEIVED HEAVY RAINFALL YESTERDAY. TS ERNESTO WILL PASS WELL SOUTH OF THE AREA OVER THE CARIB ON MONDAY. ATLANTIC HIGH PRESSURE WILL BUILD INTO SOUTH FL BEGINNING TUE AND LASTING THROUGH THE WORK WEEK WITH DRIER AIR MOVING IN FROM THE EAST. PWATS LOWER TO AROUND 1.5 INCHES WED-THU...WITH EVEN A LITTLE BIT OF HAZE FROM SAHARAN DUST POSSIBLY MOVING IN MID WEEK. SO THE FORECAST TREND IS WET THROUGH MONDAY THEN LOWERING RAIN CHANCES TUE AND BEYOND WITH TSTORMS FOCUSING OVER THE INTERIOR EACH AFTERNOON. MOISTURE BEGINS TO INCREASE BY FRI. MARINE...WINDS WILL BE ON THE INCREASE, ESPECIALLY SUN-MON WITH SEAS INCREASING INTO THE 3-5 FT RANGE. HOWEVER, NO HIGHLIGHTS ARE NEEDED AT THIS TIME. FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN TYPICALLY HIGH. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 88 78 89 79 / 70 50 60 50 FORT LAUDERDALE 88 80 89 79 / 70 50 60 50 MIAMI 89 78 89 79 / 70 50 60 50 NAPLES 91 76 92 77 / 50 30 50 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...85/AG AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS MIAMI FL
358 AM EDT SAT AUG 4 2012 ...LOCALLY HEAVY RAINFALL POSSIBLE TODAY... ...MODERATE RISK OF RIP CURRENTS ATLANTIC BEACHES... .DISCUSSION...TROPICAL DISTURBANCE OVER THE BAHAMAS HAS A LOW PROBABILITY OF DEVELOPING PER NHC...AND OUR MAIN CONCERN IS THE POTENTIAL FOR LOCALLY HEAVY RAINFALL...BUT THEN PERHAPS NOT MUCH? A CHALLENGING FORECAST INDEED. MODEL CONSENSUS IS FOR THIS AREA OF DISTURBED WEATHER OVER THE BAHAMAS, ASSOCIATED WITH A BROAD TROUGH, TO MOVE NORTHWEST AND ACROSS SOUTH FLORIDA THROUGH TONIGHT...BUT MODELS SHOWS THE BULK OF THE HEAVIER RAINFALL CONCENTRATING OVER THE LOCAL ATLANTIC WATERS. HOWEVER, SHOWERS ARE NOW DEVELOPING OVER THE ATLANTIC, ESPECIALLY EAST OF THE UPPER KEYS. FORECAST SOUNDINGS SHOW A MOIST AND UNSTABLE PROFILE WITH NO CAPPING...AND WITH PLENTY OF MORNING SUNSHINE/HEATING AND DEVELOPING INSTABILITY, WILL MAINTAIN THE INHERITED 70% EAST TO 50% GULF COAST. INTERESTING THAT THE HRRR IS IN LINE WITH THE GFS/ECMWF SHOWING MAX QPF OFFSHORE. STILL BELIEVE MOST AREAS WILL SEE RAIN ACROSS THE EAST COAST METRO (SO MAINTAINED THE HIGH POPS), DURATION AND AMOUNT IS OF HIGH UNCERTAINTY. AS THIS TROUGH PASSES SOUTH FL TO THE NW TONIGHT, AN INCREASING MOIST SOUTHEASTERLY WIND FLOW WILL DEVELOP SUN-MON. THIS IS EXPECTED TO LEAD TO CONTINUED UNSETTLED WEATHER CONDITIONS WITH BOUTS OF NUMEROUS SHOWERS/TSTORMS FOCUSED IN THE AFTERNOON ALL AREAS (FAST EAST TO WEST MOVEMENT) AND ALONG THE ATLANTIC COAST AT NIGHT. THE MAIN CONCERN IS FOR POTENTIAL LOCALIZED HEAVY RAINFALL ESPECIALLY THIS AFTERNOON AS FCST SOUNDINGS SHOW LITTLE STORM MOTION...AND ANTECEDENT HEAVY RAINS FROM YESTERDAY. STORM MOTION INCREASES SUN-MON. AT THIS TIME, THE CONCERN IS FOR LOCALIZED HEAVIER RAIN AMOUNTS OF 3+" TODAY, WHICH COULD LEAD TO ISOLATED STREET FLOODING...SIMILAR TO WHAT OCCURRED YESTERDAY WHERE HERE AT THE OFFICE WE PICKED UP 4.03" OF RAIN...BRINGING OUR YEARLY TOTAL TO 60.49"! STREET FLOODING COULD OCCUR QUICKER THAN NORMAL IF HEAVY RAINS DEVELOP OVER AREAS WHICH RECEIVED HEAVY RAINFALL YESTERDAY. TS ERNESTO WILL PASS WELL SOUTH OF THE AREA OVER THE CARIB ON MONDAY. ATLANTIC HIGH PRESSURE WILL BUILD INTO SOUTH FL BEGINNING TUE AND LASTING THROUGH THE WORK WEEK WITH DRIER AIR MOVING IN FROM THE EAST. PWATS LOWER TO AROUND 1.5 INCHES WED-THU...WITH EVEN A LITTLE BIT OF HAZE FROM SAHARAN DUST POSSIBLY MOVING IN MID WEEK. SO THE FORECAST TREND IS WET THROUGH MONDAY THEN LOWERING RAIN CHANCES TUE AND BEYOND WITH TSTORMS FOCUSING OVER THE INTERIOR EACH AFTERNOON. MOISTURE BEGINS TO INCREASE BY FRI. && .MARINE...WINDS WILL BE ON THE INCREASE, ESPECIALLY SUN-MON WITH SEAS INCREASING INTO THE 3-5 FT RANGE. HOWEVER, NO HIGHLIGHTS ARE NEEDED AT THIS TIME. && .FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN TYPICALLY HIGH. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 88 78 89 79 / 70 50 60 50 FORT LAUDERDALE 88 80 89 79 / 70 50 60 50 MIAMI 89 78 89 79 / 70 50 60 50 NAPLES 91 76 92 77 / 50 30 50 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...57/GREGORIA AVIATION/RADAR...15/JR
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
143 AM EDT SAT AUG 4 2012 .PREV DISCUSSION... /ISSUED 1013 PM EDT FRI AUG 3 2012/ UPDATE... SCATTERED TO ISOLATED THUNDERSTORM DEVELOPMENT HAS BEEN PERSISTENT OVER PORTIONS OF CENTRAL AND EASTERN GA WITH LITTLE TO NO ACTIVITY ACROSS THE NW PORTION. THE RECENT HRRR RUNS HAVE BEEN PICKING UP BETTER ON THE CONVECTION AND MAINTAINS THE DEVELOPMENT WELL INTO THE OVERNIGHT. HAVE ADJUSTED TO HAVE CHANCE POPS IN THESE AREAS THROUGH THE OVERNIGHT WHILE DECREASING THE NW AND SE PORTIONS TO SLIGHT CHANCES FROM 06-12Z. ALL ELSE SEEMS TO BE ON TRACK. PREVIOUS DISCUSSION FOLLOWS... 03 PREV DISCUSSION... /ISSUED 303 PM EDT FRI AUG 3 2012/ SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/... CURRENT RADAR LOOP SHOWS SHOWERS MOVING INTO THE AREA FROM THE NW. ISOLATED THUNDERSTORMS SHOULD START MOVING INTO THE AREA AS SOON AS THINGS DESTABILIZE A BIT MORE THIS AFTERNOON. THE BIGGEST THREAT STILL APPEARS TO BE ISOLATED AREAS OF FLOODING AS PW VALUES ARE IN THE 2 TO 2.20 INCH RANGE THROUGH 00Z SUN. CAPES ARE IN THE 1500 TO 2000 J/KG RANGE WITH LIS NEAR -3 TO -4 THIS AFTERNOON. THE INSTABILITIES DROP OFF VERY QUICKLY AFTER SUNSET BUT THE PWS CONTINUE TO STAY UP. THE SHORTWAVE MOVING SE OUT OF MIDDLE TN WILL PUSH INTO NW GA LATTER TONIGHT AND STALL ACROSS N AND W GA THROUGH 00Z SUN. IT WILL STAY THERE BEFORE BEGINNING TO MAKE ITS WAY BACK NORTHWARD AS THE BERMUDA LIKE RIDGE BEGINS TO BUILD IN FROM THE ATLANTIC SAT/SUN. WILL CONTINUE WITH LIKELY POPS THIS AFTERNOON AND TONIGHT WITH CHANCE POPS SAT/SAT NIGHT. TEMPS WILL STAY NEAR OR SLIGHTLY BELOW SEASONAL NORMS DUE TO THE PRECIP AND CLOUD COVER EXPECTED. 01 LONG TERM /SUNDAY THROUGH FRIDAY/... DESPITE SLIGHT TIMING DIFFERENCES...MODELS ARE STILL IN FAIRLY GOOD AGREEMENT WITH A COLD FRONT MOVING INTO NORTH GEORGIA ON MONDAY AND SINKING INTO CENTRAL GEORGIA ON TUESDAY. BASED ON CONSISTENCY OF MODELS WITH AFFECTS FROM FRONT EXPECTED ACROSS THE CWA MONDAY AND TUESDAY...HAVE INCREASED POPS CLOSER TO THE HIGHER END OF CHANCE. DIFFERENCES IN GFS AND ECMWF BECOME MORE APPARENT INTO MIDWEEK. 12Z GFS WANTS TO LINGER THE FRONT ACROSS THE CWA THROUGH THE LONG TERM WHILE THE 00Z ECMWF SLIDES THE BOUNDARY SOUTH OF THE AREA. WITH IT BEING SUMMER HAVE TRENDED TOWARD LOW END CHANCE POPS...CLOSER TO THE GFS SOLUTION. WITH LINGERING BOUNDARY SUGGESTED THOUGH BY THE GFS...POPS MAY BE A LITTLE ON THE LOW SIDE. 11 && .AVIATION... 06Z UPDATE... CONVECTION IN EASTERN ZONES WILL CONTINUE TO WEAKEN THROUGH THE EARLY MORNING. EXPECT THAT MOST SITES WILL SEE IFR CIGS...POSSIBLY LIFR...AROUND 12Z. CIGS WILL LIFT THROUGH MID-MORNING. EXPECT A SIMILAR CONVECTIVE PATTERN TO FRIDAY...WITH PEAK ACTIVITY AROUND 00Z. WINDS GENERALLY SOUTHEAST THROUGH THE PERIOD...LIGHT OVERNIGHT AND BETWEEN 5-10KT DURING THE DAY EXCEPT IN THUNDERSTORMS. //ATL CONFIDENCE...06Z UPDATE... MEDIUM ON MOST ELEMENTS...INCLUDING TIMING OF CONVECTION AND DEVELOPMENT OF IFR CIGS. LOW ON POTENTIAL LIFR CIG DEVELOPMENT. TDP && .PRELIMINARY POINT TEMPS/POPS... ATHENS 87 70 89 72 / 60 60 30 20 ATLANTA 89 72 91 74 / 60 60 30 20 BLAIRSVILLE 80 69 85 68 / 60 60 40 30 CARTERSVILLE 88 71 90 69 / 60 50 40 30 COLUMBUS 90 72 91 74 / 50 50 40 20 GAINESVILLE 85 71 87 72 / 60 60 30 30 MACON 93 72 91 73 / 40 40 40 20 ROME 88 71 90 71 / 50 50 40 30 PEACHTREE CITY 88 69 89 70 / 60 60 30 20 VIDALIA 93 74 92 75 / 30 30 40 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
341 PM CDT SAT AUG 4 2012 .DISCUSSION... ISSUED 341 PM CDT SAT AUG 4 2012 COLD FRONT HAS BEEN MOVING A BIT QUICKER TOWARD THE CWA...AND WAS LOCATED FROM NEAR THE QUAD CITIES SOUTHWEST TO NEAR KANSAS CITY. WELL-DEFINED MESOSCALE VORTEX FROM CONVECTION IN IOWA HELPED TO DEVELOPED AN MCS WHICH HAS BEEN ROLLING ACROSS THE NORTHERN THIRD OF ILLINOIS THIS AFTERNOON. SOME OF THE SOUTHERN FRINGES CONTINUE TO PUSH ACROSS AREAS FROM CANTON EAST TO EL PASO AT MID AFTERNOON. INSTABILITY OVER THE AREA PEAKED EARLY THIS AFTERNOON WITH CAPES AROUND 4000 J/KG...BUT SPC MESOANALYSIS HAS BEEN SHOWING SOME DECREASE IN CAPES AND INCREASE IN CAPPING ALOFT. HOWEVER...STILL QUITE A BIT OF INSTABILITY AVAILABLE FROM SOUTHERN MISSOURI NORTHEAST INTO EAST CENTRAL ILLINOIS. LATEST NAM AND HRRR SHOW DEVELOPMENT OCCURRING IN THESE AREAS OVER THE NEXT COUPLE HOURS. WILL MAINTAIN LIKELY POPS OVER A LARGE PART OF THE CWA THIS EVENING...THEN LIMIT THEM TO 40-50 PERCENT AFTER MIDNIGHT ACROSS THE EAST CENTRAL AND SOUTHEAST CWA. ANY LINGERING RAIN ACROSS THE FAR SOUTHEAST WILL LIKELY BE ENDING BEFORE SUNRISE. LITTLE CHANGE MADE TO THE REMAINDER OF THE FORECAST. BRIEF COOL DOWN WILL BE NOTED EARLY THIS WEEK AS HIGH PRESSURE DRIFTS EAST ACROSS THE AREA. A SLOW WARMING TREND WILL BRING TEMPERATURES BACK TO NEAR 90 MUCH OF THE REMAINDER OF THE WEEK...WITH HOTTER WEATHER KNOCKING ON THE DOOR AS WE REMAIN ON THE FRINGE OF THE UPPER RIDGING ACROSS THE WESTERN HALF OF THE NATION. MAIN FEATURE OF CONCERN IN THE LONG RANGE IS ON THURSDAY AND FRIDAY...WHEN A PIECE OF ENERGY DROPS SOUTHEAST OUT OF THE CANADIAN PRAIRIES. GFS AND ECMWF NOT TOO FAR APART WITH THE TRACK OF THIS SHORTWAVE OVER THE GREAT LAKES...BUT THE GFS IS MORE AGGRESSIVE WITH BRINGING RAIN CHANCES ALL THE WAY SOUTH ACROSS ILLINOIS. WILL KEEP SOME SLIGHT CHANCES IN THE GRIDS THURSDAY AND THURSDAY NIGHT...BUT WILL LEAN MORE TOWARD THE ECMWF WITH ITS ODDS OF DRY WEATHER. GEELHART && .AVIATION... ISSUED 1233 PM CDT SAT AUG 4 2012 TS ADVANCING ON THE ILLINOIS RIVER VALLEY THIS AFTERNOON RESULTING IN TS ADDED TO PIA TAF. MORE LIKELY CLOSER TO 1830Z...BUT TEMPO GROUP IN. ALSO HAVE ADDED GUSTS FOR THE AFTERNOON MOMENTUM TRANSFER THAT MAY BE SLIGHTLY DELAYED BY THE SLOW IN DIURNAL HEATING WITH THE EXPANSIVE ALTOSTRATUS AND AC OUT THERE NOW. SO FAR...CONVECTIVE DEVELOPMENT REMAINS QUESTIONABLE ELSEWHERE...AND AM KEEPING THE VCSH IN THE BEST TIME FRAME. WILL UPDATE AS BECOMES NECESSARY FOR TS. TOWARDS MORNING...CHANCE FOR BR AND REDUCED VSBYS INTO MVFR/IFR CAT REMAIN FOR TERMINALS WITH RAIN. SO FAR...PIA AND BMI ARE MOST LIKELY AT THIS POINT. AND HAVE PUT IN A BRIEF TEMPO FOR THE EARLY MORNING/DAWN HOURS. HJS && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1208 AM CDT SAT AUG 4 2012 .SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... FOCUS THROUGHOUT THE SHORT/MID RANGE WILL BE ON SYSTEM MOVING THROUGH THE REGION TONIGHT THROUGH SATURDAY NIGHT...AND ASSOCIATED COLD FRONT DROPPING THROUGH THE STATE. INITIALLY LINGERING ACTIVITY FROM EARLIER TODAY TO THE NORTHWEST HAS JUST DIMINISHED IN THE PAST FEW HOURS ACROSS NORTHWEST IOWA ASSOCIATED WITH SOME WEAK ENERGY ALOFT PUSHING OUT AHEAD OF THE MAIN WAVE. HRRR ADVERTISES SOME REDEVELOPMENT ACROSS THE NORTH CENTRAL CWA WITH THIS ENERGY...AND HAVE A FEW WEAK CELLS POPPING JUST TO THE NE OF THE CWA. ALSO HAVE DECENT CU FIELD EXTENDING BACK INTO THE CWA...WITH ANOTHER CU FIELD SITUATED ACROSS THE EXTREME SOUTHERN CWA NORTH OF ONGOING MCS THAT HAS BEEN IN PLACE ACROSS MO ALL DAY. THEREFORE HAVE SOME SLIGHT CHANCE POPS IN THE NORTH AND SOUTH THROUGH THE REMAINDER OF THE AFTERNOON HOURS WITH SPC MESODATA SUGGESTING SUFFICIENT INSTABILITY IN PLACE AND DECENT SHEAR ACROSS THE NORTH. THEREFORE AN ISOLATED SEVERE STORM CANNOT BE RULED EITHER ACROSS THE NORTH WITH ANY ACTIVITY THAT MAY DEVELOP. OTHERWISE GREATER CHANCE FOR PRECIPITATION/CONVECTION LATER TONIGHT AS STORMS CONTINUE TO DEVELOP IN VICINITY OF THE SFC FRONT SITUATED ACROSS CENTRAL SD INTO CENTRAL NE. AS THE MAIN UPPER WAVE PUSHES EAST ACROSS THE DAKOTAS AND INTO MINNESOTA SATURDAY...ASSOCIATED COLD FRONT WILL SWEEP ACROSS THE STATE...WITH SHOWERS AND THUNDERSTORMS EXPECTED TO BE ONGOING ACROSS THE NORTHWESTERN CWA SATURDAY MORNING AND CONTINUING TO TRACK EASTWARD SLOWLY DIMINISHING WITH TIME. FRONT WILL THEN PUSH INTO THE EASTERN CWA IN THE AFTERNOON HOURS...WITH REDEVELOPMENT EXPECTED BY LATE AFTERNOON ALONG THE FRONT...WITH THE FRONT EXITING THE CWA BY EARLY TO LATE EVENING AS THE UPPER SYSTEM TRACKS INTO THE GREAT LAKES REGION. THEREFORE HAVE GREATEST POPS FOR SATURDAY ACROSS THE CWA...WITH BEST CHANCE OF WIDER SPREAD PRECIPITATION AS THE AREA HAS SEEN IN A FEW WEEKS. MUCH COOLER AIR MOVING IN BEHIND THE FRONT...WITH H85 TEMPS DROPPING INTO THE LOWER TEENS TO MID TEENS CELSIUS ALOFT. THEREFORE MAX TEMPS TO BE COOLER IN AREAS BEHIND THE FRONT SATURDAY...WITH MANY SITES NOT MAKING IT OUT OF THE 70S ACROSS NORTHWESTERN IOWA AND MUCH COOLER CONDITIONS ACROSS THE ENTIRE STATE FOR SUNDAY. HIGHS SUNDAY EXPECTED TO TOP OUT IN THE 70S NORTH TO MID 80S SOUTH...WITH A QUICK CHANGE TO RETURN FLOW MONDAY AND MID 80S TO 90S WITH DRY CONDITIONS SUNDAY INTO MONDAY. ANOTHER WEAK SHORTWAVE DROPS DOWN THROUGH THE REGION MONDAY NIGHT IN NORTHWEST FLOW PATTERN ALOFT. THEREFORE COULD SEE A CHANCE FOR SOME NOCTURNAL THUNDERSTORMS MONDAY NIGHT ACROSS MUCH OF THE CWA. .LONG TERM /TUESDAY THROUGH FRIDAY/... BOTH GFS AND EURO NOW INDICATE BROAD NORTHWEST FLOW INTO NEXT WEEK AS UPPER RIDGING RETROGRADES INTO THE ROCKIES. THIS SHOULD DO A COUPLE OF THIS FOR IOWA...FIRST TEMPERATURES WILL LIKELY REMAIN COOLER DURING THE NEXT WEEK THAN WHAT PREVIOUS FORECASTS HAD GOING. READINGS ARE EXPECTED TO BE CLOSE TO NORMAL OR SLIGHTLY ABOVE BUT NOT THE 10 TO 15 DEGREE DEPARTURES WE SAW DURING MUCH OF JULY. SECOND...THE THREAT OF PRECIPITATION SHOULD BE GREATER AS WEAK SHORTWAVES IN THE FLOW DROP INTO THE MIDWEST. THE MAIN PROBLEM WITH THESE IS MORE OF A TIMING ISSUE AS IS OFTEN TYPICAL IN NORTHWEST FLOW. THESE CONDITIONS WILL CERTAINLY PROVIDE SOME RELIEF FROM THE INTENSIFYING DROUGHT WITH BOTH MODELS INDICATING THE NORTHWEST FLOW CONTINUING BEYOND THE FORECAST PERIOD. && .AVIATION...04/06Z CDFNT ENTERING NWRN IA WILL MOVE TO NEAR CENTRAL IA BY SHORTLY AFTER SUNRISE...AND PASS SOUTHEAST OF THE TAF SITES BY EARLY SAT AFTERNOON. LOW PRESSURE WAVE WILL TRAVEL NORTHEAST ALONG THE FRONT. SCATTERED TSRA WILL ACCOMPANY THE FRONT AND ALSO WILL DEVELOP NORTH OF THE FRONTAL BOUNDARY AS THE SURFACE WAVE LIFTS NEWD. HAVE CARRIED A FEW HOURS OF TSRA AROUND THE FRONT AND SHOWERS AFTER THE FRONT. THINKING IS THAT CONDITIONS WILL REMAIN VFR. CLEARING WILL SPREAD SOUTH ACROSS THE STATE LATE SAT AFTERNOON AND EVENING WITH LIGHT NWLY WINDS. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...MS AUG 12 LONG TERM...COGIL AVIATION...MS AUG 12
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
354 AM CDT SAT AUG 4 2012 ...LONG TERM SECTION UPDATED AT 355 AM... .SYNOPSIS... ISSUED AT 1035 PM CDT FRI AUG 3 2012 THE 04.00Z 250 HPA SYNOPTIC MAP SHOWED CYCLONIC FLOW ACROSS THE NORTHERN HIGH PLAINS AND ACROSS THE CANADIAN PRAIRIES. A JET STREAK OF 75 KT WAS OBSERVED AT KRIV (RIVERTON, WY). ANOTHER STRONGER JET STREAK OF 90 KT WAS OBSERVED ACROSS CENTRAL QUEBEC. AT 500 HPA, A 565 DM CYCLONE WAS LOCATED ACROSS NW NORTH DAKOTA AND EXTENDING NORTHWARD INTO SASKATCHEWAN. COLD AIR ADVECTION WAS OCCURRING UPSTREAM ACROSS MONTANA WEST OF THIS LOW WITH VALUES AROUND -18 DEG C. ANOTHER ITEM OF INTEREST AT 500 HPA WAS A LARGE 593 DM ANTICYCLONE LOCATED ACROSS THE STATE OF TEXAS. WARM MID LEVEL TEMPERATURES AROUND -3 DEG C WERE ASSOCIATED WITH THIS FEATURE. AT 700 HPA, TEMPERATURES ACROSS THE SOUTHERN AND CENTRAL PLAINS WERE STILL WARM WITH VALUES IN THE 14 TO 17 DEG C RANGE. THIS ATMOSPHERE WAS FAIRLY DRY AS WELL. FURTHER NORTH, COLD AIR AIR ADVECTION WAS OCCURRING IN THE WAKE OF THE AFOREMENTIONED MID LEVEL DISTURBANCE WITH 700 HPA TEMPERATURES AS LOW AS -2 DEG C ACROSS KGGW (GLASGOW, MT). AT 850 HPA, THERE WAS AN IMPRESSIVE TEMPERATURE GRADIENT ACROSS THE PLAINS WITH 9 DEG C AT KGGW (GLASGOW, MT) TO A VERY WARM VALUE OF 34 DEG C AT KAMA (AMARILLO, TX). AT THE SURFACE, A LOW PRESSURE SYSTEM WAS LOCATED ACROSS SOUTHEASTERN MANITOBA WITH A COLD FRONT EXTENDING SOUTHWARD TO NEBRASKA. TROPICAL STORM ERNESTO WAS LOCATED NEAR 13.9N 65.6W AT 04.03Z. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 245 AM CDT SAT AUG 4 2012 THIS MORNING: SHOWERS AND ISOLATED THUNDERSTORMS ACTIVITY LAST NIGHT WILL CONTINUE TO WEAKEN SIGNIFICANTLY OVERNIGHT. WILL GRADUALLY TAPER POPS THROUGH THIS MORNING BUT KEEP ISOLATED IN THE GRIDS AS A COLD FRONT SLOWLY APPROACHES FROM THE NW. TODAY: MUCH COOLER WEATHER IS EXPECTED TODAY AS A COLD FRONT MOVES ACROSS THE REGION. 850 HPA WINDS ARE FORECAST TO BE IN THE 20-30 KT RANGE SO DON`T THINK SURFACE WINDS WILL BE AT WIND ADVISORY CRITERIA FOR A LONG PERIOD OF TIME. THERE COULD BE SOME ISALLOBARIC FORCING IMMEDIATELY ALONG AND BEHIND THE FRONT SO WINDS MAY REACH CRITERIA JUST FOR A SHORT AMOUNT OF TIME. DID USE THE MIXED LAYER WIND TOOL AND WILL HIGHLIGHT SUB WIND ADVISORY CRITERIA IN THE HWO (MAINLY 20 TO 30 MPH). FORECAST SOUNDINGS SHOW QUITE A BIT OF MID TO UPPER LEVEL (500-300 HPA) MOISTURE SO WILL KEEP LINGERING CLOUD COVER IN THE GRIDS (PARTICULARLY FOR THE FIRST HALF OF TODAY). USED MOSGUIDANCEBC AFTER CHECKING BOISE VERIFICATION TO SEE THAT THIS OUTPUT IS PERFORMING BETTER THAN THE NAM. A LARGE TEMPERATURES GRADIENT IS EXPECTED ACROSS THE REGION WITH LOWER 80S DEG F ACROSS WEST CENTRAL KANSAS TO AROUND 100 DEG F ACROSS SOUTH CENTRAL KANSAS. WILL ALSO KEEP SLIGHT POPS GOING TODAY AS THE RIGHT ENTRANCE REGION OF A 250 HPA JET STREAK SAGS SOUTHWARD CLOSER TO SOUTHWEST KANSAS. THIS IN COMBINATION WITH WEAK ISENTROPIC LIFT COULD LEAD TO A FEW SHOWERS AND ISOLATED THUNDERSTORMS TODAY. NOT REALLY IMPRESSED WITH THE THERMODYNAMIC PROFILE IN THE SURFACE TO 700 HPA LAYER AS THIS STRATUM LOOKS FAIRLY DRY SO DON`T THINK WE WILL SEE ANY SIGNIFICANT PRECIPITATION AMOUNTS FOR THE REST OF TODAY. TONIGHT: THE WRF-ARW AND TO A LESSER EXTENT THE NAM ARE INDICATING THE POSSIBILITY OF LATE NIGHT CONVECTION ALONG THE FRONT AFTER 00Z TONIGHT. THE AFOREMENTIONED ENTRANCE REGION WILL BE EVEN CLOSER AND ALSO WITH A STRENGTHENING 850 HPA LOW LEVEL JET MAY PROVIDE ENOUGH DYNAMICS AND LIFT FOR MORE CONVECTION. WILL INCREASE POPS LATE TONIGHT ACROSS SOUTH CENTRAL KANSAS BUT WILL NOT GET CARRIED AWAY AS CONFIDENCE IS FAIRLY LOW AS THE NAM HAS THE FRONT FARTHER SOUTH INTO OKLAHOMA IN WHICH OUR REGION MAY NOT SEE ANY ADDITIONAL PRECIPITATION. LOWS HEADING INTO SUNDAY WILL BE PLEASANT WITH VALUES IN THE 50S AND 60S DEG F. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 353 AM CDT SAT AUG 4 2012 TROPICAL THUNDERSTORMS CONTINUE TO BE VERY ACTIVE NORTH OF THE EQUATOR FROM NEAR 120E TO 170E, AND A TROPICAL CYCLONE IS EVIDENT ON SATELLITE IMAGERY SOUTH OF JAPAN. THE INDIAN OCEAN HAS BEEN FAIRLY QUIET IN RECENT DAYS. IT DOES APPEAR THAT A COHERENT FEATURE IS PROPAGATING RAPIDLY EASTWARD INTO THE WESTERN HEMISPHERE AND WILL REACH THE WESTERN INDIAN OCEAN AGAIN BY MID AUGUST. ATMOSPHERIC RELATIVE ANGULAR MOMENTUM CONTINUES TO BE SLIGHTLY ABOVE CLIMATOLOGICAL VALUES, AND MOUNTAIN TORQUE HAS BECOME POSITIVE RECENTLY. ALTHOUGH THE SIGNAL IS VERY WEAK, THE ATMOSPHERE MAY BE HEADED TOWARD PHASE 5 OF THE WEICKMANN/BERRY GLOBAL WIND OSCILLATION PHASE SPACE DIAGRAM. IF THIS OCCURS, ANTICYCLONIC FLOW WILL BE FAVORED ON THE WESTERN UNITED STATES WITH A TENDENCY TOWARD TROUGHING IN THE EAST BY MID AUGUST. MOST OF THE NUMERICAL MODELS ARE SUGGESTING THIS TREND. THE ECMWF IS MORE AGGRESSIVE IN WEAKENING THE UPPER LEVEL RIDGING IN THE CENTRAL PART OF THE COUNTRY THAN THE GFS, AND MOST OF THE GEM ENSEMBLE MEMBERS MAINTAIN MORE RIDGING THAN THE ECMWF DETERMINISTIC SOLUTION. GIVEN THE HOT, DRY CONDITIONS IN THE CENTRAL AND SOUTHERN PLAINS AND IMPROBABILITY OF WIDESPREAD BENEFICIAL RAINFALL, THE GFS SOLUTION SEEMS MORE REASONABLE. THE UPPER LEVEL ANTICYCLONE CENTERED OVER SOUTHERN OKLAHOMA AND NORTHERN TEXAS WILL WEAKEN AND RETROGRADE TO NEAR 110W BY MONDAY, AND TROUGHING WILL AMPLIFY IN THE EASTERN UNITED STATES. THE PLUME OF SUBTROPICAL MOISTURE EXTENDING FROM WESTERN MEXICO TO THE CENTRAL PLAINS WILL DROP SOUTHWARD TO NEAR THE KANSAS/OKLAHOMA BORDER BY SUNDAY MORNING, AND A FEW HIGH BASED SHOWERS MAY BE IN PROGRESS UNDER THE TROPICAL PLUME SUNDAY MORNING. A WEAK UPPER LEVEL TROUGH EVIDENT ON SATELLITE IMAGERY IN NORTHERN ARIZONA WILL APPROACH THE CENTRAL PLAINS LATE SATURDAY NIGHT AND MAY ENHANCE SHOWER AND THUNDERSTORMS UNDER THE TROPICAL PLUME ALONG AND NORTH OF THE FRONTAL BOUNDARY IN THE SOUTHERN PLAINS. THE PLUME OF SUBTROPICAL MOISTURE WILL CONTINUE TO DROP SOUTHWARD AS FLOW OVER THE CENTRAL PLAINS BECOMES MORE NORTHWEST ON SUNDAY. THERE IS A MARGINAL CHANCE THAT THUNDERSTORMS IN SOUTHEASTERN COLORADO COULD CLIP THE SOUTHWEST CORNER OF KANSAS AS THEY PROPAGATE SOUTHEAST DURING THE EVENING HOURS SUNDAY, BUT CONFIDENCE IS NOT HIGH ENOUGH TO INTRODUCE POPS YET. TEMPERATURES SUNDAY SHOULD BE NEAR SEASONAL AVERAGES. VERY WARM AIR WILL SPREAD BACK INTO WESTERN KANSAS ON MONDAY AS ANOTHER UPPER LEVEL TROUGH DIGS TOWARD THE GREAT LAKES AND LOW LEVEL FLOW BECOMES MORE SOUTHWEST. TEMPERATURES MONDAY SHOULD RETURN TO NEAR 100 DEGREES ACROSS WESTERN KANSAS. A WEAK UPPER LEVEL TROUGH ROTATING AROUND THE WESTERN UNITED STATES ANTICYCLONE WILL APPROACH THE CENTRAL PLAINS BY TUESDAY MORNING. WEAK SYNOPTIC SCALE LIFTING MAY BE SUFFICIENT TO SUPPORT A FEW THUNDERSTORMS IN CENTRAL KANSAS LATE MONDAY NIGHT INTO EARLY TUESDAY, BUT CONFIDENCE IS NOT HIGH. ANOTHER UPPER LEVEL TROUGH ORIGINATING IN THE TROPICAL PACIFIC WILL MOVE OVER THE UPPER LEVEL RIDGE AND APPROACH KANSAS ON WEDNESDAY, AND THUNDERSTORM CHANCES WILL CONTINUE THROUGH THE DAY WEDNESDAY WITH THE BEST OPPORTUNITY IN CENTRAL AND EASTERN KANSAS. UPPER LEVEL HIGH PRESSURE WILL BUILD BACK INTO KANSAS THURSDAY THROUGH SATURDAY, AND MORE TEMPERATURES IN EXCESS OF 100 DEGREES CAN BE EXPECTED. THE NEXT POSSIBILITY OF RAINFALL WILL BE AROUND 12 AUGUST WHEN ANOTHER UPPER LEVEL TROUGH DIGS INTO THE UPPER MIDWEST AND SUPPORTS PROGRESSION OF A COLD FRONT INTO KANSAS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1200 AM CDT SAT AUG 4 2012 TWO FORECAST CONCERNS FOR THE 06Z TAFS. HRRR INDICATING MORE SHOWER DEVELOPMENT AHEAD OF COLD FRONT THROUGH THE OVERNIGHT HOURS. DON`T HAVE THE HIGHEST CONFIDENCE ON THIS BUT GIVEN CURRENT RADAR TRENDS, CANNOT COMPLETELY DISMISS IT EITHER. WILL KEEP -SHRA IN THE TAFS THROUGH 10Z. NEXT CONCERN IS WINDS. MESOHIGH WILL CONTINUE BREEZY S/SW WINDS THROUGH THE OVERNIGHT. A COLD FRONT WILL PASS THROUGH TOMORROW MORNING WITH A CONTINUATION OF WINDS EXCEPT FROM THE NW/N. MAGNITUDES 22-25 KT WITH GUSTS OF 30-35 KT. && .PRELIMINARY POINT TEMPS/POPS... DDC 86 62 93 64 / 20 10 0 0 GCK 83 62 92 65 / 20 10 0 0 EHA 84 65 88 68 / 20 10 10 10 LBL 87 65 90 66 / 20 10 10 10 HYS 85 58 93 63 / 20 10 0 0 P28 99 67 95 66 / 20 20 10 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SUGDEN SHORT TERM...SUGDEN LONG TERM...RUTHI AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
245 AM CDT SAT AUG 4 2012 ...UPDATE TO SHORT TERM DISCUSSION... .SYNOPSIS... ISSUED AT 1035 PM CDT FRI AUG 3 2012 THE 04.00Z 250 HPA SYNOPTIC MAP SHOWED CYCLONIC FLOW ACROSS THE NORTHERN HIGH PLAINS AND ACROSS THE CANADIAN PRAIRIES. A JET STREAK OF 75 KT WAS OBSERVED AT KRIV (RIVERTON, WY). ANOTHER STRONGER JET STREAK OF 90 KT WAS OBSERVED ACROSS CENTRAL QUEBEC. AT 500 HPA, A 565 DM CYCLONE WAS LOCATED ACROSS NW NORTH DAKOTA AND EXTENDING NORTHWARD INTO SASKATCHEWAN. COLD AIR ADVECTION WAS OCCURRING UPSTREAM ACROSS MONTANA WEST OF THIS LOW WITH VALUES AROUND -18 DEG C. ANOTHER ITEM OF INTEREST AT 500 HPA WAS A LARGE 593 DM ANTICYCLONE LOCATED ACROSS THE STATE OF TEXAS. WARM MID LEVEL TEMPERATURES AROUND -3 DEG C WERE ASSOCIATED WITH THIS FEATURE. AT 700 HPA, TEMPERATURES ACROSS THE SOUTHERN AND CENTRAL PLAINS WERE STILL WARM WITH VALUES IN THE 14 TO 17 DEG C RANGE. THIS ATMOSPHERE WAS FAIRLY DRY AS WELL. FURTHER NORTH, COLD AIR AIR ADVECTION WAS OCCURRING IN THE WAKE OF THE AFOREMENTIONED MID LEVEL DISTURBANCE WITH 700 HPA TEMPERATURES AS LOW AS -2 DEG C ACROSS KGGW (GLASGOW, MT). AT 850 HPA, THERE WAS AN IMPRESSIVE TEMPERATURE GRADIENT ACROSS THE PLAINS WITH 9 DEG C AT KGGW (GLASGOW, MT) TO A VERY WARM VALUE OF 34 DEG C AT KAMA (AMARILLO, TX). AT THE SURFACE, A LOW PRESSURE SYSTEM WAS LOCATED ACROSS SOUTHEASTERN MANITOBA WITH A COLD FRONT EXTENDING SOUTHWARD TO NEBRASKA. TROPICAL STORM ERNESTO WAS LOCATED NEAR 13.9N 65.6W AT 04.03Z. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 245 AM CDT SAT AUG 4 2012 THIS MORNING: SHOWERS AND ISOLATED THUNDERSTORMS ACTIVITY LAST NIGHT WILL CONTINUE TO WEAKEN SIGNIFICANTLY OVERNIGHT. WILL GRADUALLY TAPER POPS THROUGH THIS MORNING BUT KEEP ISOLATED IN THE GRIDS AS A COLD FRONT SLOWLY APPROACHES FROM THE NW. TODAY: MUCH COOLER WEATHER IS EXPECTED TODAY AS A COLD FRONT MOVES ACROSS THE REGION. 850 HPA WINDS ARE FORECAST TO BE IN THE 20-30 KT RANGE SO DON`T THINK SURFACE WINDS WILL BE AT WIND ADVISORY CRITERIA FOR A LONG PERIOD OF TIME. THERE COULD BE SOME ISALLOBARIC FORCING IMMEDIATELY ALONG AND BEHIND THE FRONT SO WINDS MAY REACH CRITERIA JUST FOR A SHORT AMOUNT OF TIME. DID USE THE MIXED LAYER WIND TOOL AND WILL HIGHLIGHT SUB WIND ADVISORY CRITERIA IN THE HWO (MAINLY 20 TO 30 MPH). FORECAST SOUNDINGS SHOW QUITE A BIT OF MID TO UPPER LEVEL (500-300 HPA) MOISTURE SO WILL KEEP LINGERING CLOUD COVER IN THE GRIDS (PARTICULARLY FOR THE FIRST HALF OF TODAY). USED MOSGUIDANCEBC AFTER CHECKING BOISE VERIFICATION TO SEE THAT THIS OUTPUT IS PERFORMING BETTER THAN THE NAM. A LARGE TEMPERATURES GRADIENT IS EXPECTED ACROSS THE REGION WITH LOWER 80S DEG F ACROSS WEST CENTRAL KANSAS TO AROUND 100 DEG F ACROSS SOUTH CENTRAL KANSAS. WILL ALSO KEEP SLIGHT POPS GOING TODAY AS THE RIGHT ENTRANCE REGION OF A 250 HPA JET STREAK SAGS SOUTHWARD CLOSER TO SOUTHWEST KANSAS. THIS IN COMBINATION WITH WEAK ISENTROPIC LIFT COULD LEAD TO A FEW SHOWERS AND ISOLATED THUNDERSTORMS TODAY. NOT REALLY IMPRESSED WITH THE THERMODYNAMIC PROFILE IN THE SURFACE TO 700 HPA LAYER AS THIS STRATUM LOOKS FAIRLY DRY SO DON`T THINK WE WILL SEE ANY SIGNIFICANT PRECIPITATION AMOUNTS FOR THE REST OF TODAY. TONIGHT: THE WRF-ARW AND TO A LESSER EXTENT THE NAM ARE INDICATING THE POSSIBILITY OF LATE NIGHT CONVECTION ALONG THE FRONT AFTER 00Z TONIGHT. THE AFOREMENTIONED ENTRANCE REGION WILL BE EVEN CLOSER AND ALSO WITH A STRENGTHENING 850 HPA LOW LEVEL JET MAY PROVIDE ENOUGH DYNAMICS AND LIFT FOR MORE CONVECTION. WILL INCREASE POPS LATE TONIGHT ACROSS SOUTH CENTRAL KANSAS BUT WILL NOT GET CARRIED AWAY AS CONFIDENCE IS FAIRLY LOW AS THE NAM HAS THE FRONT FARTHER SOUTH INTO OKLAHOMA IN WHICH OUR REGION MAY NOT SEE ANY ADDITIONAL PRECIPITATION. LOWS HEADING INTO SUNDAY WILL BE PLEASANT WITH VALUES IN THE 50S AND 60S DEG F. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 227 PM CDT FRI AUG 3 2012 ON SATURDAY EVENING THE COLD FRONT IS FORECAST TO EXTEND FROM SOUTH CENTRAL KANSAS INTO THE PANHANDLE OF TEXAS. THIS FRONT WILL MOVE A LITTLE FURTHER SOUTH BEFORE BECOMING STATIONARY BY EARLY SUNDAY MORNING. A WEDGE OF HIGHER DEWPOINTS WILL BE LOCATED JUST NORTH OF THIS FRONT ALONG WITH IMPROVING 850-700MB FRONTOGENESIS. UPPER LEVEL JET DYNAMICS ALONG WITH THE TIMING OF THE 500MB TROUGH SUGGESTS THE BETTER UPPER FORCING WILL BE LOCATED NEAR SOUTH CENTRAL KANSAS. FURTHER WEST WEAKER LIFT WILL BE PRESENT, HOWEVER BETTER LOW LEVEL MOISTURE AND UPSLOPE FLOW IS EXPECTED LATE DAY. GIVEN THE BETTER LIFT AND INSTABILITY ACROSS SOUTH CENTRAL KANSAS EARLY SUNDAY EVENING WILL FOCUS THE HIGHER CHANCES OF PRECIPITATION HERE WHILE LOWER CHANCES FURTHER WEST AND NORTHWEST. ON SUNDAY AN UPPER LEVEL RIDGE WILL BUILD INTO THE ROCKIES AS AN AREA OF HIGH PRESSURE AT THE SURFACE MOVES SOUTHEAST ACROSS THE CENTRAL PLAINS. SKIES ARE EXPECTED TO BE MOSTLY SUNNY WITH 850MB TEMPERATURES AT 00Z MONDAY RANGING FROM THE LOW TO MID 20S. MIXDOWN TEMPERATURES FROM THE NAM, MEAN SREF, AND ECMWF CONTINUE TO SUGGEST HIGHS MAINLY IN THE LOW TO MID 90S SO THE PREVIOUS FORECAST STILL LOOKS ON TRACK. ON SUNDAY NIGHT THE SURFACE HIGH WILL MOVE EAST INTO THE MID MISSISSIPPI VALLEY AND 850MB WARM AIR ADVECTION ALONG WITH I310-I315 ISENTROPIC LIFT STARTS TO IMPROVE ACROSS SOUTHWEST KANSAS. MOISTURE MAY BE SOMEWHAT LIMITED, DEPENDING ON WHICH MODEL YOU PREFER. AT THIS TIME GIVEN IMPROVING LIFT WILL INCREASE CLOUD COVER BUT STILL AM LEANING TOWARD HOLDING OFF MENTIONING PRECIPITATION. INCREASING CLOUDS WILL HOWEVER AID IN KEEPING TEMPERATURES UP A FEW DEGREES COMPARED TO WHAT THE LATEST GUIDANCE SUGGESTS. ON MONDAY AND TUESDAY A TROUGH OF LOW PRESSURE WILL DEEPEN ALONG THE LEE OF THE ROCKIES AS 850-700MB TEMPERATURES BEGIN WARM. A 4-6C 24HOUR 850MB TEMPERATURE WARM UP IS FORECAST BY ALL THE MODELS BETWEEN 00Z MONDAY AND 00Z TUESDAY. TEMPERATURES THEN VARY FROM 1 TO 3C BETWEEN 00Z TUESDAY AND 00Z WEDNESDAY. GIVEN THIS TREND SEE LITTLE REASON TO DISAGREE WITH TEMPERATURES NOT REBOUNDING BACK INTO THE MID 90S TO AROUND 100 DEGREES BOTH DAYS. BY MID WEEK THE UPPER LEVEL RIDGE AXIS WILL EXTEND FROM THE FOUR CORNERS REGION INTO SOUTHWEST CANADA. UPPER LEVEL DISTURBANCES WILL ROTATE AROUND THIS UPPER RIDGE AND DOWN THE NORTHWEST FLOW. A WEAK SURFACE BOUNDARY IS FORECAST TO MOVE INTO WESTERN KANSAS TUESDAY NIGHT/WEDNESDAY AND MAY PROVIDE THE FOCUS FOR SOME LATE DAY/OVERNIGHT THUNDERSTORMS AS ANY ONE OF THESE UPPER WAVES MOVE ALONG THE NORTHWEST FLOW AND ACROSS KANSAS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1200 AM CDT SAT AUG 4 2012 TWO FORECAST CONCERNS FOR THE 06Z TAFS. HRRR INDICATING MORE SHOWER DEVELOPMENT AHEAD OF COLD FRONT THROUGH THE OVERNIGHT HOURS. DON`T HAVE THE HIGHEST CONFIDENCE ON THIS BUT GIVEN CURRENT RADAR TRENDS, CANNOT COMPLETELY DISMISS IT EITHER. WILL KEEP -SHRA IN THE TAFS THROUGH 10Z. NEXT CONCERN IS WINDS. MESOHIGH WILL CONTINUE BREEZY S/SW WINDS THROUGH THE OVERNIGHT. A COLD FRONT WILL PASS THROUGH TOMORROW MORNING WITH A CONTINUATION OF WINDS EXCEPT FROM THE NW/N. MAGNITUDES 22-25 KT WITH GUSTS OF 30-35 KT. && .PRELIMINARY POINT TEMPS/POPS... DDC 86 62 91 70 / 20 10 10 10 GCK 83 62 90 69 / 20 10 10 10 EHA 84 65 90 69 / 20 10 10 10 LBL 87 65 91 70 / 20 10 10 10 HYS 85 58 91 69 / 20 10 0 10 P28 99 67 94 71 / 20 20 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SUGDEN SHORT TERM...SUGDEN LONG TERM...BURGERT AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1200 AM CDT SAT AUG 4 2012 ...UPDATE TO AVIATION FOR 06Z TAFS... .SYNOPSIS... ISSUED AT 1035 PM CDT FRI AUG 3 2012 THE 04.00Z 250 HPA SYNOPTIC MAP SHOWED CYCLONIC FLOW ACROSS THE NORTHERN HIGH PLAINS AND ACROSS THE CANADIAN PRAIRIES. A JET STREAK OF 75 KT WAS OBSERVED AT KRIV (RIVERTON, WY). ANOTHER STRONGER JET STREAK OF 90 KT WAS OBSERVED ACROSS CENTRAL QUEBEC. AT 500 HPA, A 565 DM CYCLONE WAS LOCATED ACROSS NW NORTH DAKOTA AND EXTENDING NORTHWARD INTO SASKATCHEWAN. COLD AIR ADVECTION WAS OCCURRING UPSTREAM ACROSS MONTANA WEST OF THIS LOW WITH VALUES AROUND -18 DEG C. ANOTHER ITEM OF INTEREST AT 500 HPA WAS A LARGE 593 DM ANTICYCLONE LOCATED ACROSS THE STATE OF TEXAS. WARM MID LEVEL TEMPERATURES AROUND -3 DEG C WERE ASSOCIATED WITH THIS FEATURE. AT 700 HPA, TEMPERATURES ACROSS THE SOUTHERN AND CENTRAL PLAINS WERE STILL WARM WITH VALUES IN THE 14 TO 17 DEG C RANGE. THIS ATMOSPHERE WAS FAIRLY DRY AS WELL. FURTHER NORTH, COLD AIR AIR ADVECTION WAS OCCURRING IN THE WAKE OF THE AFOREMENTIONED MID LEVEL DISTURBANCE WITH 700 HPA TEMPERATURES AS LOW AS -2 DEG C ACROSS KGGW (GLASGOW, MT). AT 850 HPA, THERE WAS AN IMPRESSIVE TEMPERATURE GRADIENT ACROSS THE PLAINS WITH 9 DEG C AT KGGW (GLASGOW, MT) TO A VERY WARM VALUE OF 34 DEG C AT KAMA (AMARILLO, TX). AT THE SURFACE, A LOW PRESSURE SYSTEM WAS LOCATED ACROSS SOUTHEASTERN MANITOBA WITH A COLD FRONT EXTENDING SOUTHWARD TO NEBRASKA. TROPICAL STORM ERNESTO WAS LOCATED NEAR 13.9N 65.6W AT 04.03Z. && .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 352 PM CDT FRI AUG 3 2012 A NEARLY STATIONARY FRONT EXTENDED FROM SOUTHEAST KANSAS INTO THE TEXAS PANHANDLE THIS AFTERNOON. LOW LEVEL MOISTURE WAS "POOLING" NORTH OF THE FRONT OVER SOUTHWEST KANSAS WITH DEWPOINTS IN THE UPPER 50S TO LOWER 60S, LEADING TO SURFACE BASED CAPE FROM 1000-1500 J/KG. A SHORTWAVE TROUGH WAS PROGRESSING ACROSS THE NORTHERN ROCKIES TODAY AND WILL MOVE ACROSS THE NORTHERN PLAINS ON SUNDAY. THIS FEATURE WILL HELP DRAG A COLD FRONT THROUGH SOUTHWEST KANSAS SATURDAY MORNING. THE WARM FRONT WILL MOVE NORTHWARD TONIGHT INTO SOUTHWEST KANSAS. A FEW THUNDERSTORMS MAY DEVELOP NEAR AND NORTH OF THE WARM FRONT THIS AFTERNOON AND PROPAGATE NORTHWARD AND EASTWARD THIS EVENING INTO KANSAS. ALSO, SURFACE BASED CONVECTIVE INITIATION COULD OCCUR ACROSS SOUTHEAST COLORADO THIS EVENING AND THEN PROGRESS INTO SOUTHWEST KANSAS PER NAM/HRRR. GIVEN THE AFOREMENTIONED CAPE AND INCREASING HIGH LEVEL WINDS TO 40-45KTS, THESE STORMS ARE CAPABLE OF HAIL AS LARGE AS QUARTERS AND WINDS ARE HIGH AS 60 MPH. DECIDED TO CARRY THE HIGHEST POPS IN FAR SOUTHWEST KANSAS THIS EVENING. ADDITIONAL ELEVATED THUNDERSTORMS COULD DEVELOP LATER TONIGHT FURTHER NORTHEAST AND POSSIBLY INTO THE FIRST HALF OF THE DAY SATURDAY. THE PREVIOUS TEMPERATURE FORECAST WAS IN GOOD SHAPE FOR TONIGHT AND FRIDAY. SOME CLOUD COVER SHOULD KEEP TEMPERATURES FROM FALLING TOO MUCH TONIGHT, ALTHOUGH THE WINDS COULD GO LIGHT AROUND 12Z AHEAD OF THE FRONT WHICH WOULD PROMOTE RADIATIONAL COOLING. WINDS SHOULD BE JUST SHY OF ADVISORY CRITERIA FOR FRIDAY BEHIND THE COLD FRONT. TEMPERATURES WILL RISE INTO THE MID TO UPPER 80S FOR MOST OF SOUTHWEST KANSAS, EXCEPT FOR 95 TO 101 IN SOUTH CENTRAL KANSAS INCLUDING BARBER, PRATT AND COMANCHE COUNTIES WHERE THE FRONT WILL NOT ARRIVE UNTIL 2-3 PM. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 227 PM CDT FRI AUG 3 2012 ON SATURDAY EVENING THE COLD FRONT IS FORECAST TO EXTEND FROM SOUTH CENTRAL KANSAS INTO THE PANHANDLE OF TEXAS. THIS FRONT WILL MOVE A LITTLE FURTHER SOUTH BEFORE BECOMING STATIONARY BY EARLY SUNDAY MORNING. A WEDGE OF HIGHER DEWPOINTS WILL BE LOCATED JUST NORTH OF THIS FRONT ALONG WITH IMPROVING 850-700MB FRONTOGENESIS. UPPER LEVEL JET DYNAMICS ALONG WITH THE TIMING OF THE 500MB TROUGH SUGGESTS THE BETTER UPPER FORCING WILL BE LOCATED NEAR SOUTH CENTRAL KANSAS. FURTHER WEST WEAKER LIFT WILL BE PRESENT, HOWEVER BETTER LOW LEVEL MOISTURE AND UPSLOPE FLOW IS EXPECTED LATE DAY. GIVEN THE BETTER LIFT AND INSTABILITY ACROSS SOUTH CENTRAL KANSAS EARLY SUNDAY EVENING WILL FOCUS THE HIGHER CHANCES OF PRECIPITATION HERE WHILE LOWER CHANCES FURTHER WEST AND NORTHWEST. ON SUNDAY AN UPPER LEVEL RIDGE WILL BUILD INTO THE ROCKIES AS AN AREA OF HIGH PRESSURE AT THE SURFACE MOVES SOUTHEAST ACROSS THE CENTRAL PLAINS. SKIES ARE EXPECTED TO BE MOSTLY SUNNY WITH 850MB TEMPERATURES AT 00Z MONDAY RANGING FROM THE LOW TO MID 20S. MIXDOWN TEMPERATURES FROM THE NAM, MEAN SREF, AND ECMWF CONTINUE TO SUGGEST HIGHS MAINLY IN THE LOW TO MID 90S SO THE PREVIOUS FORECAST STILL LOOKS ON TRACK. ON SUNDAY NIGHT THE SURFACE HIGH WILL MOVE EAST INTO THE MID MISSISSIPPI VALLEY AND 850MB WARM AIR ADVECTION ALONG WITH I310-I315 ISENTROPIC LIFT STARTS TO IMPROVE ACROSS SOUTHWEST KANSAS. MOISTURE MAY BE SOMEWHAT LIMITED, DEPENDING ON WHICH MODEL YOU PREFER. AT THIS TIME GIVEN IMPROVING LIFT WILL INCREASE CLOUD COVER BUT STILL AM LEANING TOWARD HOLDING OFF MENTIONING PRECIPITATION. INCREASING CLOUDS WILL HOWEVER AID IN KEEPING TEMPERATURES UP A FEW DEGREES COMPARED TO WHAT THE LATEST GUIDANCE SUGGESTS. ON MONDAY AND TUESDAY A TROUGH OF LOW PRESSURE WILL DEEPEN ALONG THE LEE OF THE ROCKIES AS 850-700MB TEMPERATURES BEGIN WARM. A 4-6C 24HOUR 850MB TEMPERATURE WARM UP IS FORECAST BY ALL THE MODELS BETWEEN 00Z MONDAY AND 00Z TUESDAY. TEMPERATURES THEN VARY FROM 1 TO 3C BETWEEN 00Z TUESDAY AND 00Z WEDNESDAY. GIVEN THIS TREND SEE LITTLE REASON TO DISAGREE WITH TEMPERATURES NOT REBOUNDING BACK INTO THE MID 90S TO AROUND 100 DEGREES BOTH DAYS. BY MID WEEK THE UPPER LEVEL RIDGE AXIS WILL EXTEND FROM THE FOUR CORNERS REGION INTO SOUTHWEST CANADA. UPPER LEVEL DISTURBANCES WILL ROTATE AROUND THIS UPPER RIDGE AND DOWN THE NORTHWEST FLOW. A WEAK SURFACE BOUNDARY IS FORECAST TO MOVE INTO WESTERN KANSAS TUESDAY NIGHT/WEDNESDAY AND MAY PROVIDE THE FOCUS FOR SOME LATE DAY/OVERNIGHT THUNDERSTORMS AS ANY ONE OF THESE UPPER WAVES MOVE ALONG THE NORTHWEST FLOW AND ACROSS KANSAS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1200 AM CDT SAT AUG 4 2012 TWO FORECAST CONCERNS FOR THE 06Z TAFS. HRRR INDICATING MORE SHOWER DEVELOPMENT AHEAD OF COLD FRONT THROUGH THE OVERNIGHT HOURS. DON`T HAVE THE HIGHEST CONFIDENCE ON THIS BUT GIVEN CURRENT RADAR TRENDS, CANNOT COMPLETELY DISMISS IT EITHER. WILL KEEP -SHRA IN THE TAFS THROUGH 10Z. NEXT CONCERN IS WINDS. MESOHIGH WILL CONTINUE BREEZY S/SW WINDS THROUGH THE OVERNIGHT. A COLD FRONT WILL PASS THROUGH TOMORROW MORNING WITH A CONTINUATION OF WINDS EXCEPT FROM THE NW/N. MAGNITUDES 22-25 KT WITH GUSTS OF 30-35 KT. && .PRELIMINARY POINT TEMPS/POPS... DDC 69 87 61 91 / 80 20 10 10 GCK 71 86 59 90 / 60 20 10 10 EHA 70 86 61 90 / 80 20 20 10 LBL 71 88 62 91 / 80 20 20 10 HYS 71 86 58 91 / 20 20 0 0 P28 76 99 68 94 / 80 20 20 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SUGDEN SHORT TERM...FINCH LONG TERM...BURGERT AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
936 AM EDT SAT AUG 04 2012 .Mesoscale Discussion... Issued at 936 AM EDT Sat Aug 4 2012 With the exception of a slight uptick in intensity over the southern Blue Grass, storms in the rest of the LMK CWA are continuing to fall apart this morning. Once the Blue Grass convection heads east/weakens, we should see a relative lull in the precip before scattered storms are able to fire up in the warm unstable air this afternoon. In the grids we have decreased PoPs for the late morning hours before bringing them back up in the afternoon. Have been keeping an eye on the convection south of St Louis this morning. HRRR has had the best handle on this activity, and that model dives the thunderstorms to the SSE through western Kentucky, west Tennessee, and into Alabama. So far this is being borne out on regional radar loops. However, while that path would be to the west of the LMK CWA, model data are hinting at new convection possibly firing up on outflow heading east from the Mississippi Valley storms into central Kentucky and, to a lesser extent, southern Indiana. This further supports chance PoPs for the afternoon hours. We have cut high temps in the southeast where morning clouds and showers will linger the longest. Have left temperatures alone in the rest of the area where more sunshine is occurring or expected. May flirt with Heat Advisory criteria briefly this afternoon in the far west, thanks more to dew points in the lower and middle 70s than the air temperature, but with cirrus shield moving in from the west and the brevity of any indices AOA 105, will stick with the SPS for now. Issued at 810 AM EDT Sat Aug 4 2012 Storms have been on the decrease over the past couple of hours as the NLLJ weakens. However, some strong storms remain, especially INVOF Elizabethtown and Hodgenville. Torrential rainfall is occurring in these low centroid storms thanks to very high precipitation efficiency in a soupy air mass. Have upped PoPs to categorical where it is currently raining as well as downstream to the east. Have also introduced "heavy rain" wording -- the Elizabethtown KY Mesonet site reported 0.31 inches of rain in just 5 minutes. Have also greatly increased QPF numbers, to around an inch and a half INVOF the Hardin/LaRue storms, and 0.50-0.75" downstream into the Blue Grass. && .Short Term (Today through Sunday)... Issued at 325 AM EDT Sat Aug 4 2012 A lot to talk about in the short-term period. To start off with, a weak low-level jet is setting up early this morning across central Kentucky. This is aiding in moisture advection and lift. A few showers and thunderstorms have developed along the KY-TN border and continue to push northeast into central Kentucky. Additional development is possible, but overall areal coverage should be limited. These, mainly isolated, showers and thunderstorms will dissipate as the low-level jet relaxes shortly after sunrise. We should then be mainly dry until the afternoon hours, but an isolated shower/storm cannot be ruled out given the moist air mass. For the rest of today, there is a weak wave across portions of Missouri propagating eastward early this morning. It seems this will initiate convection across eastern Missouri a little later, which will push east into our area later this afternoon. This should act to increase our thunderstorm potential and coverage throughout the day, particularly with diurnal heating. Will have to see if this solution pans out, but either way, convection should fire this afternoon just due to heating, with highs topping out in the lower 90s. Heat indices will top out in mid and upper 90s across the east, with 100 to around 105 expected along and west of I-65. Still expecting convection to decrease as the sun sets this evening. Activity should ramp up again, mainly across southern Indiana and north-central Kentucky as a low-level jet increases ahead of our approaching cold front. Convection associated with this feature appears to dissipate a bit shortly after sunrise as well, with the loss of the low-level jet. However, convection will increase in coverage throughout the day Sunday, mainly across central Kentucky and points south/east, as the cold front pushes southeast through the forecast area during peak heating. Here is a caveat. The latest 4km NAM indicates convection along the cold front should initiate late this afternoon/early evening across portions of northern Illinois and central Missouri. This model generates a good cold pool, which drops the convection quickly southeast and into portions of southern Indiana shortly after midnight. This line appears to be in a weakening stage, but arrives faster than most models are predicting. This solution also continues pushing the outflow boundary southeast where additional storm development occurs across central and south-central Kentucky before sunrise Sunday. If this pans out, most convection will be overnight, with the Sunday afternoon storms having less coverage and being confined to the frontal boundary forcing. Given the uncertainty amongst models and this seeming to be an outlier, will not jump completely on this solution, but this will be key to watch as the day unfolds. This model has shown some positive results over the last few days. Otherwise, models continue to indicate total PWs of almost 2 inches for today, which increases to just over 2 inches for Sunday. High temperatures Sunday should reach the mid and upper 80s, with a few locations perhaps touching 90 degrees. This will yield CAPE values in the 2000-3000 J/kg range, especially across southern and eastern portions of the forecast area during Sunday afternoon. Shear appears to be maximized in the afternoon as well, with 0-6km bulk shear values in the 20-30 knot range. Damaging wind, very heavy rainfall, and some hail will be the main threats. Given the recent rainfall across the area and the increase in total moisture through Sunday, there could be localized flash flooding concerns. .Long Term (Sunday Night through Friday)... Issued at 304 AM EDT Sat Aug 4 2012 The first forecast challenge in the long term will be the timing of Sunday`s cold front pushing through the region Sun night/early Mon. Models vary in exactly when the front and unstable airmass will push south of our area. Because this weather system is on in the stronger side, will go with a more progressive soln closer to the 0Z GFS and GFS ensembles. This would push the front through early Mon morning and stall it out just to our south over TN during the day Mon. So, with this timing in mind, strong to severe storms with damaging winds, torrential rainfall, and cloud to ground lightning may linger east of I-65 early Sun night. After midnight, expect storms to decrease in strength and be more confined to the Lake Cumberland region. For Mon, will keep 20-30% chance POPs in the southeast CWA which may or may not pan out depending on the exact location of the front and left over showers/t-storms. Temps will be tricky to nail down Sun night and Mon depending on the exact front position and clearing of clouds from NW to SE. Will go with a decent gradient of highs/lows for the Sun night/Mon time period. Looks like lows Sun night should bottom out in the mid 60s north to lower 70s south. Highs on Monday should range from the upper 80s to around 90 north to lower 80s southeast. Sfc high pressure will settle in for Tues and most of Wed keeping conditions dry with low humidity. Seasonal temps will prevail in the upper 80s and lower 90s for highs both days. With mostly clear skies, low temps will bottom out in the 60s. By late Wed, the left over boundary from early in the week, will transition to more of an inverted trough forecast to move back north into our region by Thurs. Along with this weak boundary, an upper low will dive south into the Great Lakes region with an upper level shortwave around its periphery making its way into the Ohio Valley. Therefore, will continue 30% POPs for Thurs. For Fri and into the weekend, long range models diverge on how far south the upper low will travel and to what degree of strength it will have. At this point, at least some troughing and a cold front look possible toward Thurs night/Fri time frame. Thus will keep low POPs going with cooler temps (mid 80s) in store for the weekend. && .Aviation (12Z TAF Issuance)... Issued at 648 AM EDT Sat Aug 4 2012 Isolated to scattered showers/storms around BWG and LEX early this morning will continue to push northeast as a weak low-level jet remains overhead. Isolated cells are moving away from BWG, while thunderstorms will be in the vicinity of LEX for a little longer this morning. Could see cigs drop at LEX too if the storms move directly overhead. Storm coverage should decrease as the low-level jet relaxes. Winds will become south-southwesterly and increase between 10 and 15 mph, with gusts 20-25 mph by this afternoon. Diurnal Cu will develop once again, with storm chances increasing during peak heating. A weak wave across Missouri this morning is initiating convection across the mid Mississippi Valley. This activity should push east, which could mean slightly greater areal storm coverage later this afternoon. Will continue VCTS and a CB group in the TAFs for this. Overnight, another low-level jet will strengthen overhead, with borderline LLWS setting up across the area starting around 06Z. At the same time, storms could develop during the pre-dawn hours along the Ohio River. At this time, will not mention LLWS, but will include VCTS at SDF for the early morning storm chance. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...NONE. KY...NONE. $$ Mesoscale........13 Short Term.......MJP Long Term........AMS Aviation.........MJP
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1246 AM EDT SAT AUG 4 2012 .SYNOPSIS... A COLD FRONT WILL CROSS THE AREA THIS EVENING AND MOST OFF THE COAST OVERNIGHT. HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR SATURDAY INTO SUNDAY. && .NEAR TERM /THROUGH TODAY/... 1245 AM UPDATE...NO SIGNIFICANT CHANGES NEEDED FOR THIS UPDATE. ONLY MADE MINOR TWEAKS TO TREND TOWARD CURRENT CONDITIONS. PREV DISCUSSION... CHALLENGES WILL ARE CONVECTION THIS AFTERNOON INTO THE EVENING AND HOW STRONG AND HOW EXTENSIVE WILL THE FOG BE. TSTMS FIRING ACROSS NORTHERN AND CENTRAL AREAS ATTM AHEAD OF THE APCHG COLD FRONT. STILL EXPECTING CONVECTION TO FIRE UP ACROSS PORTIONS OF THE CENTRAL HIGHLANDS AND DOWNEAST REGIONS LATER THIS AFTERNOON AS BEST INSTABILITY SHIFTS SSE. SPC MESO-ANALYSIS INDICATES THIS ATTM. ALSO, THINKING HEAVY RAINFALL AND STRONG WIND GUSTS STILL POSSIBLE. SBCAPES UP AROUND 2000+ JOULES W/LIS DOWN TO AROUND -5. 0-6KM SHEAR FROM THE LATEST RUC WAS AROUND 25KTS WHICH WOULD FAVOR POSSIBLE DOWNBURST WINDS. EXPECTING CONVECTION TO WIND DOWN THIS EVENING AS INSTABILITY AXIS SHIFTS EAST INTO NEW BRUNSWICK. COLD FRONT WILL CLEAR THE COAST TONIGHT W /DRIER-COOLER AIR EXPECTED TO FILTER BEHIND THE FRONT. MIDNIGHT CREW/S OVERNIGHT MINS OF LOW/MID 50S ACROSS THE NORTH W /MID-UPPER 50S CENTRAL AND DOWNEAST LOOKED GOOD. THE OTHER CONCERN IS FOG RETURNING OVERNIGHT INTO SATURDAY MORNING. DECIDED ON AREAS OF FOG RIGHT ALONG THE IMMEDIATE COAST AND OVER THE WATERS. FURTHER INLAND, WENT W/PATCHY FOG FOR NOW GIVEN THE DRYING TREND. THERE COULD BE A BRIEF TIME WHEN VSBYS DROP LOWER AS DEWPOINT ALIGNS W/THE TEMPERATURE. THIS WILL BE ESPECIALLY TRUE IN AREAS FROM EARLIER RAINFALL. HIGH PRES BUILDING INTO THE REGION FROM CANADA ON SATURDAY WILL PROVIDE DRY AND PLEASANT CONDITIONS FOR EARLY AUGUST. MAX TEMPERATURES SHOULD HAVE NO PROBLEM REACHING WELL INTO THE 80S W/AMPLE SUNSHINE. LATEST MOS/NAM MAXES MATCHED CLOSE TO WHAT THE MIDNIGHT CREW HAS AND THEREFORE ONLY TWEAKING WAS DONE FOR THE COAST TO BRING MAXES UP DUE TO OFFSHORE WINDS. && .SHORT TERM /TONIGHT THROUGH MONDAY/... A WARM FRONT WILL LIFT NORTH THROUGH THE REGION SATURDAY NIGHT INTO SUNDAY USHERING IN VERY WARM AND HUMID CONDITIONS. EXPECT HIGHS SUNDAY GENERALLY IN THE MID 80S WITH DEW POINTS RISING INTO THE MID TO HIGH 60S. WINDS WILL BE GUSTY OUT OF THE SOUTH AND THIS WILL HELP TO KEEP TEMPERATURES COOLER ALONG THE COAST WHERE HIGHS WILL BE IN THE 70S. CLOUDS WILL INCREASE IN THE AFTERNOON AHEAD OF AN APPROACHING COLD FRONT BUT ANY SHOWER/THUNDERSTORM ACTIVITY LOOKS TO REMAIN WEST OF THE REGION THROUGH THE DAY. AS THE COLD FRONT CONTINUES TO ADVANCE SUNDAY NIGHT SHOWERS WITH POSSIBLE THUNDERSTORMS WILL ROLL THROUGH FROM WEST TO EAST AHEAD OF FRONT DURING THE LATE EVENING INTO THE OVERNIGHT. INSTABILITY LOOKS TO BE MARGINAL DUE TO THE TIMING OF THE FRONT BEING AT NIGHT AND AS A RESULT ANY CONVECTION THAT OCCURS DOES NOT LOOK TO BE SEVERE, ALTHOUGH SOME HEAVY DOWNPOURS WILL BE POSSIBLE. BY MONDAY MORNING THE FRONT LOOKS TO BE SITUATED CLOSE TO THE WESTERN EDGE OF THE STATE. SHOWERS AND STORMS WILL CLEAR THE AREA FROM WEST TO EAST THROUGH THE DAY AS THE FRONT ADVANCES EAST. THE BEST CHANCE FOR ANY STRONGER STORMS MONDAY WILL BE DOWNEAST AS THAT AREA WILL BE LAST TO CLEAR DURING THE AFTERNOON. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... ZONAL FLOW WILL DEVELOP BEHIND AN EXITING COLD FRONT MONDAY NIGHT. DRY WEATHER IS EXPECTED IN THE WAKE OF THIS FRONT THROUGH TUESDAY NIGHT. THE PERSISTENT SUMMER 2012 UPPER TROUGH RETURNS WEDNESDAY THROUGH FRIDAY. ANTICIPATE A CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS DAYS 5 THROUGH 7 WITH DISTURBANCES ROTATING AROUND THE BASE OF THE TROUGH. TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE LONG TERM PERIOD. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... NEAR TERM: VFR W/TEMPO MVFR THIS AFTERNOON INTO THE EVENING W/TSTMS FIRING. LEANED W/MVFR VSBY LATER TONIGHT INTO SATURDAY MORNING FOR THE NORTHERN TERMINALS WHILE KBGR AND KBHB ARE EXPECTED TO DROP TO IFR BY 09Z SATURDAY. AFTER 12Z SATURDAY, LOOKS LIKE VFR. SHORT TERM: LOOKS LIKE VFR SATURDAY NIGHT INTO SUNDAY FOR THE MOST PART. HOWEVER, MVFR AND IFR POSSIBLE ACROSS KBGR AND KBHB COULD BE SEEN EARLY SUNDAY MORNING AS WINDS BECOME SOUTHERLY AHEAD OF AN APPROACHING COLD FRONT. SUNDAY NIGHT INTO MONDAY COULD BE INTERESTING AS THAT STRONGER COLD FRONT MOVES ACROSS THE REGION W/POSSIBLE TSTMS AND WIND AND MVFR/IFR CONDITIONS. && .MARINE... NEAR TERM: NO HEADLINES. MAIN CHALLEGE WILL THE CONTINUING 4-5 FOOT SWELL WHICH IS OUT THERE ATTM. WINDS WILL INCREASE SOME OVERNIGHT W/THE COLD FROPA, BUT WINDS WILL RELAX ON SATURDAY AS HIGH PRES MOVES IN FROM CANADA. AREAS OF FOG WILL BE NUISANCE OVERNIGHT BUT VSBYS SHOULD IMPROVE LATER SATURDAY MORNING. USED THE NAM12 AND GFS FOR THE WINDS WHICH SUPPORT 10-15 KTS TONIGHT AND THEN SPEEDS FROP OFF FOR SATURDAY. BROUGHT THE SWELL DOWN TO 3 FT BY MIDDAY SATURDAY W/AN OFFSHORE FLOW. SHORT TERM: POSSIBLE SCA FOR SUNDAY NIGHT INTO MONDAY AS PRES GRADIENT TIGHTEN AHEAD AND W/THE FRONTAL PASSAGE. WINDS START COMING DOWN LATER MONDAY INTO TUESDAY. BACKED OFF A BIT ON THE WNAWAVE BY DROPPING THEM BACK 1-2 FEET. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HASTINGS/HEWITT SHORT TERM...FITZSIMMONS LONG TERM...OKULSKI AVIATION...HASTINGS/HEWITT MARINE...HASTINGS/HEWITT/FITZSIMMONS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
434 PM EDT SAT AUG 4 2012 .SHORT TERM...(TONIGHT) ISSUED AT 432 PM EDT SAT AUG 4 2012 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A VIGOROUS LOOKING SHORTWAVE TROF ACROSS THE ERN DAKOTAS/MN. AT THE SFC...ASSOCIATED COLD FRONT IS SLICING THRU WRN LAKE SUPERIOR/WRN UPPER MI AND NW WI. DESPITE VIGOROUS LOOK OF SHORTWAVE...CONVECTION HAS BEEN KEPT IN CHECK BY ABUNDANT CLOUD COVER THAT HAS PERSISTED THRU THE DAY ACROSS GOOD PORTIONS OF UPPER MI AND NRN WI. LATEST SPC MESOANALYSIS SHOWS MLCAPE OF MOSTLY UNDER 500J/KG ACROSS THE FCST AREA. HIGHEST VALUES...A LITTLE OVER 500J/KG...ARE OVER THE E WHERE THERE HAS BEEN MORE SUNSHINE WITH SFC DWPTS AROUND 70F. IF MORE INSTABILITY HAD DEVELOPED...A FAIRLY SIGNIFICANT SVR WEATHER OUTBREAK WOULD PROBABLY BE GETTING UNDERWAY ACROSS THE FCST AREA AS DEEP LAYER SHEAR IS STEADILY INCREASING TOWARD THE 40-50KT RANGE DUE TO MIDLEVEL SPEED MAX APPROACHING THE AREA. MAIN SHOW TONIGHT WILL BE S OF THE AREA WITH CONVECTIVELY ENHANCED SHORTWAVE TRACKING TOWARD SRN WI/NRN IL/LWR MI. THE ONGOING ASSOCIATED CLUSTER OF STRONG/SVR STORMS WILL PASS S OF THE AREA. THAT SAID...OVER THE NEXT FEW HRS...SHRA/TSRA SHOULD TEND TO EXPAND NE ACROSS ROUGHLY THE E HALF OF THE FCST AREA AS HEIGHT FALLS AND RIGHT ENTRANCE OF UPPER JET STREAK WORK TO INCREASE UPWARD MOTION. THERE IS STILL THE POTENTIAL OF ISOLD SVR STORMS...BUT WITH CLOUD COVER NOW INCREASING EVEN OVER THE ERN FCST AREA TO PREVENT INSTABILITY FROM BUILDING HIGHER...IT APPEARS RISK OF SVR STORMS IS DIMINISHING. WILL KEEP SLIGHT RISK OF SVR WORDING IN HAZARDOUS WX OUTLOOK FOR THE NEXT FEW HRS OR SO. AFTER ANY SHRA/TSRA WITH COLD FRONT DEPART...ATTENTION TURNS TO VORT MAX AND SECONDARY COLD FRONT THAT WILL SWING INTO THE AREA LATE TONIGHT. THERE HAS BEEN FAIRLY SOLID COVERAGE OF SHRA AND EVEN SCT TSRA ACROSS SE MANITOBA INTO ADJACENT NRN ONTARIO WITH TROF AXIS THOUGH PCPN HAS TAKEN ON MORE OF A DIURNAL SCT COVERAGE THIS AFTN. AS TROF AXIS/VORT MAX DROP INTO THE AREA...THERE SHOULD BE DECENT SHRA COVERAGE LATE TONIGHT INTO SUN MORNING...ESPECIALLY SINCE CAA DROPS 850MB TEMPS TO AROUND 6C BY 12Z SUN. WITH WATER TEMPS AROUND 20C ON LAKE SUPERIOR...THE OVERWATER INSTABILITY WILL BE MORE THAN SUFFICIENT FOR LAKE ENHANCEMENT UNDER CYCLONIC FLOW WITH ARRIVAL OF VORT MAX. THUS...EXPECT SCT/NMRS SHRA TO DEVELOP LATE TONIGHT OVER THE NW HALF OF UPPER MI. AS ALWAYS...UPSLOPE NW WINDS WILL LEAD TO MOST NMRS COVERAGE OVER THE HIGHER TERRAIN DOWNWIND OF THE LAKE. .LONG TERM...(SUNDAY THROUGH SATURDAY) ISSUED AT 432 PM EDT SAT AUG 4 2012 GOOD AGREEMENT FM THE GFS/ECMWF/GEM-NHEM WITH OVERALL UPPER AIR PATTERN THROUGH THIS WEEK. PATTERN STARTS OFF WITH DEEP TROUGH OVER THE UPPER GREAT LAKES AND BROAD WEST-TO-EAST RIDGE ACROSS THE SOUTHERN TIER OF THE CONUS. BY MIDWEEK...RIDGE BECOMES MORE AMPLIFIED OVER INTERMOUNTAIN WEST INTO WESTERN CANADA WHILE TROUGHING REMAINS IN PLACE OVER EASTERN CANADA AND THE GREAT LAKES AND NORTHEAST CONUS. WEATHER WILL STAY ON THE ACTIVE SIDE AS MULTIPLE SYSTEMS IMPACT THE UPPER GREAT LAKES. FIRST WILL BE RIGHT AT BEGINNING OF LONG TERM ON SUNDAY. ANOTHER WEAKER COLD FRONT COMES THROUGH AREA ON TUESDAY. MUCH STRONGER LOW PRESSURE SYSTEM FCST TO PUSH ACROSS GREAT LAKES LATER THURSDAY INTO FRIDAY. IT IS THIS SYSTEM THAT SHOWS THE MOST POTENTIAL TO PRODUCE NOTEABLE PRECIPITATION AMOUNTS IN THE LONG TERM. SINCE THE LARGE TROUGH IS CLOSE BY AND RIDING REMAINS WELL TO THE WEST...EXPECT TEMPERATURES TO GENERALLY BE WITHIN A FEW DEGREES OF NORMAL. ONLY WARM EXCEPTION WILL BE ON MONDAY AHEAD OF ANOTHER COLD FRONT. SOME COOL PERIODS ARE EXPECTED AS WELL. COOLEST OF THE BUNCH LIKELY WILL BE ON SUNDAY...BUT SIMILAR COOLER TEMPERATURES MAY OCCUR AGAIN ON FRIDAY ON IN WAKE OF LOW PRESSURE SYSTEM MOVING THROUGH THE GREAT LAKES. A VERY CHAGEABLE WEATHER DAY IS IN STORE FOR SUNDAY. COLD FRONT THROUGH UPR MICHIGAN BY DAYBREAK WHILE SFC LOW PUSHES ACROSS JAMES BAY. COOL AND MOIST CYCLONIC FLOW SFC THROUGH H7 AFFECTS MOST CWA THROUGH LATE MORNING THEN HEIGHTS RISE QUICKLY WHILE EDGE OF SFC HIGH BUILDS IN MID-LATE AFTN. MOIST CYCLONIC FLOW AND THERMAL TROUGH WITH H85 TEMPS AS LOW AS +5C IN ADDITION TO A SHARP SECONDARY WAVE DROPPING THROUGH MEAN TROUGH SHOULD COMBINE TO BRING A PERIOD OF SHOWERS TO PORTIONS OF CWA THROUGH THE MORNING. WARM LK SUPERIOR TEMPS NEAR +20C ALSO ALLOW LAKE EFFECT PROCESSES TO ENHANCE PCPN AS DELTA T/S ARE AROUND 14-15C/LAKE INDUCED CAPES UP TO 250 J/KG. INCREASED POPS OVER UPSLOPE AREAS FAVORED BY NW BLYR WINDS. HIGHEST POPS IN THE MORNING...THEN RAPIDLY DROPPING OFF IN THE AFTN AS AREA QUICKLY RESIDES IN SUBSIDENCE REGION OF THE STRONG SHORTWAVE. SKIES PROBABLY CLEAR QUICKLY IN THE AFTN DUE TO SUBSIDENCE AND DRY AIR. TEMPS KIND OF TRICKY...BUT FOLLOWED TREND CLOSER TO GEM-REGIONAL SHOWING TEMPS STUCK IN THE MID 50S-LOW 60S INTO EARLY AFTN...THEN RISING TOWARD 70 DEGREES LATER IN THE DAY WITH INCREASING SUNSHINE. GUSTY WINDS OTHER FACTOR ON SUNDAY AS DEEP MIXING EXPECTED THROUGH EARLY AFTN BEFORE H85 WARM ADVECTION INCREASES STABILITY. MIXED LAYER WINDS THROUGH 16Z 35-40KT AND EXPECT GOOD PORTION OF THESE TO MIX TO SFC. STRONGEST WINDS NEAR EXPOSED LK SUPERIOR SHORE OF CNTRL AND EAST. EXPECT WINDS TO DIMINISH BY LATE DAY. HIGH PRESSURE AXIS REMAINS JUST SOUTH OF AREA SUNDAY NIGHT BUT WINDS BECOME LIGHT ENOUGH/PWAT LOW ENOUGH TO SEE SOME RADIATIONAL COOLING TAKE PLACE. LOWEST MINS SEEM LIKELY IN THE INTERIOR CNTRL AND EAST WHERE COLD SPOTS MAY DROP INTO LOWER 40S. MUCH DIFFERENT DAY ON MONDAY COMPARED TO COOLER/WINDY DAY ON SUNDAY. HIGH PRESSURE SLIDES EAST AND A WEAK COLD FRONT IS FCST TO DROP INTO UPR LAKES MONDAY NIGHT. NOT A LOT OF CLOUD COVER AHEAD OF FRONT THOUGH OTHER THAN ON THE KEWEENAW IN THE LATER AFTN. WITH H85 TEMPS 15C-16C EXPECT HIGHS TO REACH WELL INTO THE 80S AWAY FM LK MICHIGAN SHORE. AS UPR JET SLIDES ACROSS ONTARIO MONDAY NIGHT AND MID-LEVEL FGEN INCREASES OVR LK SUPERIOR...EXPECT BAND OF SHRA/TSRA TO DEVELOP ALONG SFC FRONT. FRONT SLIDES THROUGH CWA ON MONDAY NIGHT...WITH BETTER CHANCES OF SHRA/TSRA TIED INTO THE MID-LEVEL FORCING. SOUNDINGS SHOW DRY AIR LINGERING BLO H85-H7 DUE TO LIMITED MOISTURE ADVECTION FM THE GULF INTO THIS SYSTEM. SO...COVERAGE OF PRECIP WILL BE SPOTTY WITH THE FRONT. HIGH PRESSURE BUILDS BACK IN FOR TUESDAY WITH TEMPS IN THE 70S NORTH AND NEARING 80 DEGREES OVR THE SOUTH AND NEAR LK MICHIGAN. EXTENDED...MAIN CHANCES FOR SHRA/TSRA COME IN LATER WEDNESDAY NIGHT INTO THURSDAY AS ANOTHER UPPER LOW AND SFC LOW MOVE ACROSS THE UPR LAKES. CYCLONIC FLOW LINGERING IN THE WAKE OF THE SFC LOW COULD KEEP SOME SHRA GOING OVR THE AREA INTO FRIDAY...KIND OF SIMILAR TO WHAT IS EXPECTED ON SUNDAY. WITH EXPECTED CLOUDS/PCPN...TRIMMED TEMPS THURSDAY AND FRIDAY CLOSER TO LK SUPERIOR WHERE ONSHORE NORTHEAST FLOW SHOULD RESULT IN COOLER CONDITIONS. INCREASED WINDS OVR LK SUPERIOR SOME COMPARED TO GUIDANCE CONSENSUS BUT MAY NEED TO INCREASE FURTHER WITH LATER FCSTS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 139 PM EDT SAT AUG 4 2012 COLD FRONT MOVING ACROSS THE AREA THIS AFTN/EVENING AND FOLLOWED BY SECONDARY COLD FRONT LATE TONIGHT/SUN MORNING WILL BE THE FEATURES OF INTEREST. CLOUD COVER PER SATELLITE IMAGERY SHOULD SUFFICIENTLY HOLD INSTABILITY DOWN TO KEEP TSRA POTENTIAL MINIMAL WITH FIRST COLD FROPA AT KIWD/KCMX. HAVE ONLY INCLUDED VCSH MENTION THRU THE MID TO LATE AFTN HRS AT THOSE SITES. KSAW IS MORE LIKELY TO SEE TSRA LATER THIS AFTN DUE TO BETTER POTENTIAL FOR INSTABILITY TO BUILD PRIOR TO FROPA. IF TSRA OCCUR...IFR/LIFR CONDITIONS POSSIBLE ALONG WITH GUSTY WINDS. A PERIOD OF VFR CONDITIONS EXPECTED AT ALL SITES AFTER FIRST FROPA. SECONDARY COLD FROPA LATER TONIGHT/SUN MORNING WILL BRING GUSTY NW WINDS TO ROUGHLY 25-30KT...STRONGEST AT KCMX DUE TO FAVORABLE WIND DIRECTION AND INCREASING OVERWATER INSTABILITY UNDER INCOMING BRIEF SHOT OF COOL AIR. WITH OVERWATER INSTABILITY BECOMING SUFFICIENT FOR LAKE ENHANCEMENT...CYCLONIC FLOW AND PASSING SHORTWAVE SHOULD RESULT IN A SEVERAL HR PERIOD OF IFR CONDITIONS IN SHRA/BR AT ALL SITES LATER TONIGHT/SUN MORNING. IMPROVEMENT TO VFR EXPECTED AT KIWD/KCMX LATE MORNING/EARLY AFTN AND AT KSAW JUST AFTER THIS FCST PERIOD AS STRONG SUBSIDENCE/DRYING ARRIVE UNDER PROGRESSIVE FLOW PATTERN. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 432 PM EDT SAT AUG 4 2012 COLD FRONT PASSES ACROSS LK SUPERIOR THIS EVENING. PERIOD OF STRONG WINDS AND HIGH WAVES /LIKELY OVR 10 FEET/ EXPECTED LATE TONIGHT THROUGH MUCH OF SUNDAY AFTERNOON. EXPECT 25-30 KT WINDS FM THE NORTHWEST DURING ON SUNDAY WITH FREQUENT GALE GUSTS 35-40 KTS. A GALE WATCH HAS BEEN POSTED FOR THE EAST HALF OF LK SUPERIOR MOST OF SUNDAY. WINDS DIMINISH SUNDAY NIGHT...BUT THEN INCREASE FM THE SOUTHWEST ON MONDAY AHEAD OF A COLD FRONT THAT SLIDES THROUGH ON MONDAY NIGHT. IN WAKE OF THE FRONT...EXPECT WINDS 20 KTS OR LESS TUESDAY INTO WEDNESDAY AS HIGH PRESSURE MOVES ACROSS THE REGION. WINDS MAY END UP STRONGER THAN FCST FOR LATE THIS WEEK AS DETAILS ARE SORTED OUT REGARDING ANOTHER LOW PRESSURE SYSTEM MOVING THROUGH THE UPPER GREAT LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING FOR LSZ251- 267. GALE WATCH FROM SUNDAY MORNING THROUGH SUNDAY AFTERNOON FOR LSZ249-250-266. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...ROLFSON MARINE...JLA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
154 PM CDT SAT AUG 4 2012 .UPDATE... 18Z AVIATION DISCUSSION ADDED BELOW. && .DISCUSSION... THE POWERFUL UPPER LEVEL SYSTEM WHICH SPARKED THE SQUALL LINE THAT MARCHED ACROSS THE REGION OVERNIGHT WILL BE RESPONSIBLE FOR A FEW MORE STORMS TODAY. IN THE WAKE OF THIS SYSTEM IS MUCH COOLER AND DRIER AIR...WHICH WILL SETTLE IN ACROSS THE UPPER MIDWEST FOR A MAJORITY OF THIS COMING WEEK. TODAY...EARLY MORNING WATER VAPOR IMAGERY WITH 500MB HEIGHTS AND WINDS SHOWED A BEAUTIFUL UPPER LEVEL WAVE SLIDING DOWN ACROSS THE DAKOTAS. THIS WAVE HAD ITS ORIGINS FROM ALBERTA CANADA...BUT THE DIFFERENCE BETWEEN THIS SYSTEM AND A TYPICAL ALBERTA CLIPPER IS THAT THIS STORM WAS ABLE TO TAP INTO THE MONSOONAL MOISTURE ASSOCIATED WITH THE SUBTROPICAL JET OFF THE SOUTHWEST US. THE COMBINATION OF THE STRONG DYNAMICAL FORCING WITH THE CANADIAN WAVE...AND THE FAVORABLE THERMODYNAMICS OF THE SUBTROPICAL AIRMASS LED TO SEVERAL AREAS OF SHOWERS AND THUNDERSTORMS FROM NORTHERN WISCONSIN THROUGH CENTRAL NEBRASKA. THE COMBINATION OF BOTH THE PHASING OF THE SUBTROPICAL AND NORTHERN STREAM JETS...ALONG WITH THE CONTINUED BANGING ON THE TROPOSPHERIC DRUM BY REPEATED ROUNDS OF CONVECTION WILL CAUSE A +110KT JET STREAK TO FORM OVER NORTHERN MINNESOTA BY LATER THIS AFTERNOON. THE AGEOSTROPHIC DIVERGENCE IN THE RIGHT ENTRANCE REGION OF THIS JET...THE DOWNSTREAM POSITIVE VORTICITY ADVECTION ASSOCIATED WITH THE UPPER LEVEL WAVE...AND THE LOW/MID LEVEL FRONTOGENESIS WITH THE APPROACHING COLD FRONT WILL SUPPLY PLENTY OF FORCING FOR CONTINUED PRECIP THROUGH THIS MORNING AND EARLY AFTERNOON ACROSS THE SOUTHERN AND EASTERN CWA. FORECAST SOUNDINGS SHOW DEEP LAYER SPEED SHEAR FAVORABLE FOR ORGANIZED CONVECTION...BUT THE COLD AIR ADVECTION SHOULD LIMIT THE INSTABILITY AND CONFINE SEVERE POTENTIAL TO CENTRAL AND EASTERN WISCONSIN...DESPITE THE STRONG DYNAMICS. NONE THE LESS...COULD SEE A FEW STRONGER STORMS EARLIER TODAY ACROSS FAR SOUTHERN AND EASTERN MINNESOTA...AND WESTERN WISCONSIN. IN THE WAKE OF THIS FRONT...NORTHWEST WINDS WILL INCREASE ACROSS THE ALEXANDRIA/ST CLOUD AREA WITH AFTERNOON MIXING AND COLD AIR ADVECTION. TONIGHT THROUGH FRIDAY...AN UPPER LEVEL RIDGE WILL SET UP ACROSS THE 4-CORNERS REGION AND NORTHWEST FLOW WILL PREVAIL OVER THE UPPER MIDWEST. FOR SUNDAY...COOLER AIR ON THE BACK SIDE OF THE AFOREMENTIONED UPPER LEVEL WAVE WILL WRAP IN AND LIKELY BRING AN END TO THE 80 DEGREE STREAK AT MINNEAPOLIS...WITH HIGHS ONLY EXPECTED TO BE IN THE 70S REGION WIDE. A WEAK WAVE EMBEDDED IN THIS FLOW REGIME WILL TRACK ACROSS THE REGION ON MONDAY...AND COULD SEE SOME PRECIP DEVELOP ACROSS THE SOUTH LATE MONDAY ALONG AN AREA OF H850 THETA_E ADVECTION. A SIMILAR FEATURE WILL TRACK ACROSS THE REGION ON WEDNESDAY...WITH A MORE POTENT WAVE DROPPING DOWN FROM CANADA OVER LAKE SUPERIOR ON THURSDAY. HAVE SOME 20-30 POPS IN THE GRIDS TO ACCOUNT FOR THESE TWO FEATURES. TEMPERATURES WILL BE NEAR THE SEASONAL AVERAGE FOR LATE SUMMER. && .AVIATION.../18Z TAF ISSUANCE/ PRIMARY FRONT HAS JUST CLEARED EAU...WITH A SECONDARY COLD FRONT ASSOCIATED WITH THE UPPER LOW SLIDING SE ACROSS NODAK AND NW MN. BAND OF MVFR CIGS IS WORKING ACROSS WRN WI BEHIND THE FRONT AND WILL LINGER IN EAU THROUGH NO LATER THAN 20Z. COLD AIR ALOFT ASSOCIATED WITH TROUGH LEADING TO THE DEVELOPMENT OF SCT SHOWERS NW OF THE MPX AREA...THOUGH AS THE UPPER WAVE MOVES IN...EXPECT SCT SHOWERS TO REACH DOWN INTO THE AXN/STC AREAS. FEEL HRRR IS A BIT TOO AGGRESSIVE IN BRINGING SCT SHOWERS CLEAR DOWN TO THE IA BORDER. TONIGHT...AS SECONDARY COLD FRONT SWINGS THROUGH...WINDS WILL TURN NW AND WILL LIKELY COME WITH A BOUT OF MVFR CIGS...ESPECIALLY ACROSS CENTRAL MN...THOUGH MSP/RNH/EAU MAY SEE SOME MVFR CONDITIONS AS THE COLD AIR TROUGH MOVES THROUGH. AFTER THAT...WEATHER LOOKS QUITE TRANQUIL FOR SUNDAY. KMSP...ONLY A COUPLE OF MINOR THINGS TO WATCH THIS PERIOD. FIRST...WITH SECONDARY FRONT TO DROP THROUGH THIS EVENING...MAY SEE ENOUGH BACKING IN WINDS TO RESULT IN AN OCCASIONAL 250/260 DIRECTIONAL THROUGH 00Z BEFORE A MORE UNIFORM NW WINDS SETS UP THIS EVENING. THERE WILL ALSO BE THE VERY SMALL THREAT OF AN ISOLATED SHOWER AT THE AIRPORT THIS AFTERNOON...BUT BEST CHANCES SHOULD BE CLOSER TO THE COLD AIR ALOFT NW OF THE FIELD. FINALLY...PER THE RAP/NAM...EXPECT A BAND OF MVFR CIGS TO SWING ACROSS NRN/CENTRAL MN THIS EVENING...WHICH MAY BRING THE THREAT FOR AN MVFR CIG BETWEEN 5 AND 10Z BEFORE SKIES GO SKC. /OUTLOOK/ .MONDAY...VFR. WINDS SW AT 10KT. .TUESDAY...VFR. WINDS NW AT 5KT. .WEDNESDAY...VFR. WINDS SOUTH 5 KNOTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ JRB/MPG
AREA FORECAST DISCUSSION
NWS DULUTH MN
1236 PM CDT SAT AUG 4 2012 .AVIATION...18Z TAFS MVFR CIGS WILL LINGER ACROSS FAR E MINNESOTA AND NW WISCONSIN THROUGH EARLY THIS AFTERNOON...INCLUDING AT KDLH/KHYR...DUE TO THE LOW STRATUS ASSOCIATED WITH A COLD FRONT THAT MOVED THROUGH THE REGION EARLIER THIS MORNING. THE VFR CONDITIONS THAT HAVE DEVELOPED ACROSS THE REST OF THE NE MINNESOTA SHOULD SPREAD INTO NW WISCONSIN THIS AFTERNOON. VFR CONDITIONS SHOULD PREDOMINATE FOR THE MID TO LATE AFTERNOON...BUT ANOTHER COLD FRONT BEGINNING TO MOVE INTO FAR NW MINNESOTA WILL BEGIN TO MOVE INTO NE MINNESOTA MID TO LATE AFTERNOON. THIS SECOND COLD FRONT WILL PROBABLY RESULT IN SCATTERED RAIN SHOWERS...AND MAYBE SOME WEAK THUNDERSHOWERS. AT THIS POINT...INCLUDED VCSH AND TEMPO OF -RA FOR KINL/KHIB/KBRD...BUT MAY NEED TO INCLUDE VCTS OR TEMPO OF -TSRA ONCE ANY STORMS MOVE INTO OR DEVELOP OVER NE MINNESOTA. ALSO...THE SHOWERS AND STORMS MAY RESULT IN BRIEF PERIODS OF MVFR CIGS AND VSBYS. WESTERLY WINDS OF 10 TO 15 KNOTS WITH GUSTS UP TO 25 KNOTS ARE GENERALLY EXPECTED THROUGH EARLY THIS EVENING AT ALL TERMINALS...WITH WINDS RELAXING AND BECOMING NORTHWESTERLY TONIGHT. MVFR CIGS WILL PROBABLY REAPPEAR THIS THIS EVENING IN THE WAKE OF THE COLD FRONT...BUT CLEAR SKIES SHOULD DEVELOP LATE TONIGHT. && .PREV DISCUSSION... /ISSUED 933 AM CDT SAT AUG 4 2012/ UPDATE... SPREAD SCATTERED SHOWERS FURTHER WEST AND DE-EMPHASIZED THUNDER ACROSS THE AREA THIS MORNING. DECREASED WINDS A LITTLE THIS MORNING. SHORT TERM... THE ACTUAL FRONT IS MOVING THROUGH THE DULUTH AREA MID-MORNING THIS MORNING. IT IS BECOMING A STRONG FRONT...WITH THE UPPER FLOW AND THERMAL WIND LINING UP MORE AND MORE PARALLEL TO IT. THIS SLOWS DOWN ITS FORWARD PROGRESS AND INCREASES MOISTURE AND CAUSES PRECIPITATION TO FILL IN BEHIND IT. BRIEF SURFACE RIDGING BEHIND THE FRONT IS FOLLOWED BY THE TROUGH THAT REFLECTS FALLING HEIGHTS ALOFT. WE LEFT IN SHOWERS AND DID NOT DE-EMPHASIZE THUNDERSTORMS THIS AFTERNOON INTO THE EVENING...THUNDERSTORMS WILL BE SHALLOW... BRIEF...AND SPOTTY IN DISTRIBUTION. SOUTHWEST WINDS WILL COME UP A LITTLE LATER...AS THE SECOND TROUGH APPROACHES...AND SLOWLY VEER. PREV DISCUSSION... /ISSUED 631 AM CDT SAT AUG 4 2012/ AVIATION...12Z TAFS. FIRST FRONTAL BOUNDARY IS MOVING THROUGH FA ATTM. A FEW SHOWERS WILL OCCUR IN THE VCNTY OF THE FRONT. LATER TODAY...THE SECOND FRONT WILL BEGIN TO CROSS THE AREA WITH ADDITIONAL SHOWERS AND POSSIBLY A THUNDERSTORM. A MIX OF MVFR/IFR CIGS WITH THE FIRST FRONT UNTIL AROUND 15Z THEN AN IMPROVEMENT TO VFR. WITH THE SECOND FRONT...CIGS WILL DROP BACK INTO THE MVFR WITH VCSH AT MOST SITES FROM 18Z TO 00Z. CIGS IMPROVE TO VFR WITH THE DEPARTURE OF THE FRONT AND DRIER AIR ARRIVING WITH HIGH PRESSURE AFTER 06Z. PREV DISCUSSION... /ISSUED 323 AM CDT SAT AUG 4 2012/ SHORT TERM...THROUGH SUNDAY. CONVECTIVE SYSTEM WILL EXIT THE CWA OVER THE CWA IN THE NEXT 2 TO 3 HOURS. GUSTY WINDS...30-45 MPH AND SOME HAIL WILL BE POSSIBLE IN SPOTS WITH THIS LINE. THE FRONTAL BOUNDARY WAS STILL WEST OF THE CWA...AND SHOULD REACH OUR EASTERN MN ZONES BY 12Z...AND EXIT THE EASTERN CWA BY MID AFTERNOON. THE 925MB BOUNDARY WILL TAKE A BIT LONGER TO EXIT...AND IS FORECAST TO BE THROUGH THE ARROWHEAD AND OUR EASTERN WI COUNTIES AT 18Z. ADDITIONAL SHOWERS AND STORMS WERE FIRING IN SOUTHERN MINNESOTA/SOUTHEAST SOUTH DAKOTA ALONG AND AHEAD OF THE FRONT. UPPER WAVE WAS ALSO MOVING THROUGH THE DAKOTAS...WHICH WILL AID IN ADDITIONAL LIFT. POPS ARE A BIT TRICKY THIS MORNING. WE HAVE THEM HIGHEST IN THE EAST...AND WENT DRY IN THE FAR WEST. WE`LL KEEP AN EYE ON THE ACTIVITY IN SOUTH DAKOTA AND MAY HAVE TO INCLUDE A POP IN PORTIONS OF THE WEST-SOUTHWEST THIS MORNING IF THAT ACTIVITY PERSISTS OR EXPANDS. HIGH RES WRF AND HRRR SHOW THIS FALLING APART AS IT MOVES EAST-NORTHEAST. THIS AFTERNOON SHOULD SEE THE HIGHER CHANCES FOR SHOWERS/STORMS IN THE NORTH CLOSER TO THE UPPER LOW AND COLDER TEMPS ALOFT. WE HAVE A CHANCE FOR SHOWERS AND STORMS ACROSS MOST ZONES...RANGING FROM SLIGHT TO LIKELY. SHOWERS WILL DIMINISH THROUGH THE EVENING...BUT WE KEPT A MENTION OF SHOWERS ALL NIGHT IN THE ARROWHEAD IN AREA OF HIGHEST MOISTURE/AND NEAREST THE UPPER LOW. IT SHOULD BE DRY SUNDAY WITH HIGH PRESSURE BUILDING IN. TEMPERATURES TODAY AND SUNDAY FOR MOST AREAS WILL BE IN THE SEVENTIES. EXPECT LOWS TONIGHT TO DROP INTO THE UPPER FORTIES IN THE TRADITIONALLY COLDER SPOTS...WITH 50 TO 55 ELSEWHERE. LONG TERM...SUNDAY NIGHT THROUGH FRIDAY. SFC RIDGING COVERS THE FA SUNDAY NIGHT. ON MONDAY...A WEAK COLD FRONT WILL CROSS INTO THE FA FROM CANADA. HAVE SMALL POPS IN THE AFTERNOON IN RESPONSE TO SHORT WAVE ENERGY INTERACTING WITH THE FRONT TO POSSIBLY GENERATE THUNDERSTORMS. THE FRONT WILL CROSS THE REST OF THE FA MONDAY NIGHT. MOISTURE IS LIMITED AND HAVE SMALL POPS IN NW WI FOR ANY STORMS. RIDGING RETURNS FOR TUESDAY AND TUESDAY NIGHT. BY WEDNESDAY...A WARM FRONT IS PROGGED TO LIFT NWD INTO THE FA FROM THE SW. MEANWHILE...AN UPPER LEVEL SHORT WAVE DROPS OUT OF CANADA. THESE FEATURES WARRANT A SMALL POP. MOISTURE IS LIMITED AHEAD OF THE FRONT AND THAT IS WHERE THESE STORMS ARE EXPECTED TO DEVELOP AND HAVE SMALL POPS. A STRONG CUT OFF LOW WILL MOVE ACROSS SOUTH CENTRAL CANADA WEDNESDAY NIGHT. THIS PUSHES A SFC LOW AND STRONG COLD FRONT THROUGH THE FA. GFS AND ECMWF DISAGREE ON TIMING AND OVERALL COVERAGE SO CHANCE POPS USED. THE UPPER LOW CONTINUES TO MOVE SEWD AND GENERATE ADDITIONAL PCPN AND MAINTAINED POPS IN THE PATH OF THE LOW. LINGERED POPS THURSDAY NIGHT IN THE FAR EASTERN WI FA FOR AN LINGERING STORMS AS THE UPPER LOW DEPARTS. RIDGING RETURNS FOR FRIDAY. AVIATION...06Z ISSUANCE WIDESPREAD SHOWERS AND THUNDERSTORMS CURRENTLY LOCATED OVER THE REGION WILL GRADUALLY EXIT TO THE EAST THROUGH 12Z. EXPECT VARIABLE WIND GUSTS TO 30 KT AND MVFR/IFR CONDITIONS IN ANY OF THESE STORMS. WEST TO NORTHWEST SURFACE WINDS AND VFR CONDITIONS WILL PREVAIL THROUGH MID-DAY SATURDAY...WITH SCATTERED RAIN SHOWERS AND CEILINGS AROUND 4-6 KFT MAINLY AFTER 20Z. && .POINT TEMPS/POPS... DLH 53 76 55 83 / 20 10 0 10 INL 45 77 54 80 / 40 10 0 20 BRD 53 77 53 85 / 10 10 0 10 HYR 54 76 50 84 / 10 10 0 10 ASX 55 77 54 82 / 20 10 0 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...EOM LONG TERM....GROCHOCINSKI AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
933 AM CDT SAT AUG 4 2012 .UPDATE... SPREAD SCATTERED SHOWERS FURTHER WEST AND DE-EMPHASIZED THUNDER ACROSS THE AREA THIS MORNING. DECREASED WINDS A LITTLE THIS MORNING. && .SHORT TERM... THE ACTUAL FRONT IS MOVING THROUGH THE DULUTH AREA MID-MORNING THIS MORNING. IT IS BECOMING A STRONG FRONT...WITH THE UPPER FLOW AND THERMAL WIND LINING UP MORE AND MORE PARALLEL TO IT. THIS SLOWS DOWN ITS FORWARD PROGRESS AND INCREASES MOISTURE AND CAUSES PRECIPITATION TO FILL IN BEHIND IT. BRIEF SURFACE RIDGING BEHIND THE FRONT IS FOLLOWED BY THE TROUGH THAT REFLECTS FALLING HEIGHTS ALOFT. WE LEFT IN SHOWERS AND DID NOT DE-EMPHASIZE THUNDERSTORMS THIS AFTERNOON INTO THE EVENING...THUNDERSTORMS WILL BE SHALLOW... BRIEF...AND SPOTTY IN DISTRIBUTION. SOUTHWEST WINDS WILL COME UP A LITTLE LATER...AS THE SECOND TROUGH APPROACHES...AND SLOWLY VEER. .PREV DISCUSSION... /ISSUED 631 AM CDT SAT AUG 4 2012/ AVIATION...12Z TAFS. FIRST FRONTAL BOUNDARY IS MOVING THROUGH FA ATTM. A FEW SHOWERS WILL OCCUR IN THE VCNTY OF THE FRONT. LATER TODAY...THE SECOND FRONT WILL BEGIN TO CROSS THE AREA WITH ADDITIONAL SHOWERS AND POSSIBLY A THUNDERSTORM. A MIX OF MVFR/IFR CIGS WITH THE FIRST FRONT UNTIL AROUND 15Z THEN AN IMPROVEMENT TO VFR. WITH THE SECOND FRONT...CIGS WILL DROP BACK INTO THE MVFR WITH VCSH AT MOST SITES FROM 18Z TO 00Z. CIGS IMPROVE TO VFR WITH THE DEPARTURE OF THE FRONT AND DRIER AIR ARRIVING WITH HIGH PRESSURE AFTER 06Z. PREV DISCUSSION... /ISSUED 323 AM CDT SAT AUG 4 2012/ SHORT TERM...THROUGH SUNDAY. CONVECTIVE SYSTEM WILL EXIT THE CWA OVER THE CWA IN THE NEXT 2 TO 3 HOURS. GUSTY WINDS...30-45 MPH AND SOME HAIL WILL BE POSSIBLE IN SPOTS WITH THIS LINE. THE FRONTAL BOUNDARY WAS STILL WEST OF THE CWA...AND SHOULD REACH OUR EASTERN MN ZONES BY 12Z...AND EXIT THE EASTERN CWA BY MID AFTERNOON. THE 925MB BOUNDARY WILL TAKE A BIT LONGER TO EXIT...AND IS FORECAST TO BE THROUGH THE ARROWHEAD AND OUR EASTERN WI COUNTIES AT 18Z. ADDITIONAL SHOWERS AND STORMS WERE FIRING IN SOUTHERN MINNESOTA/SOUTHEAST SOUTH DAKOTA ALONG AND AHEAD OF THE FRONT. UPPER WAVE WAS ALSO MOVING THROUGH THE DAKOTAS...WHICH WILL AID IN ADDITIONAL LIFT. POPS ARE A BIT TRICKY THIS MORNING. WE HAVE THEM HIGHEST IN THE EAST...AND WENT DRY IN THE FAR WEST. WE`LL KEEP AN EYE ON THE ACTIVITY IN SOUTH DAKOTA AND MAY HAVE TO INCLUDE A POP IN PORTIONS OF THE WEST-SOUTHWEST THIS MORNING IF THAT ACTIVITY PERSISTS OR EXPANDS. HIGH RES WRF AND HRRR SHOW THIS FALLING APART AS IT MOVES EAST-NORTHEAST. THIS AFTERNOON SHOULD SEE THE HIGHER CHANCES FOR SHOWERS/STORMS IN THE NORTH CLOSER TO THE UPPER LOW AND COLDER TEMPS ALOFT. WE HAVE A CHANCE FOR SHOWERS AND STORMS ACROSS MOST ZONES...RANGING FROM SLIGHT TO LIKELY. SHOWERS WILL DIMINISH THROUGH THE EVENING...BUT WE KEPT A MENTION OF SHOWERS ALL NIGHT IN THE ARROWHEAD IN AREA OF HIGHEST MOISTURE/AND NEAREST THE UPPER LOW. IT SHOULD BE DRY SUNDAY WITH HIGH PRESSURE BUILDING IN. TEMPERATURES TODAY AND SUNDAY FOR MOST AREAS WILL BE IN THE SEVENTIES. EXPECT LOWS TONIGHT TO DROP INTO THE UPPER FORTIES IN THE TRADITIONALLY COLDER SPOTS...WITH 50 TO 55 ELSEWHERE. LONG TERM...SUNDAY NIGHT THROUGH FRIDAY. SFC RIDGING COVERS THE FA SUNDAY NIGHT. ON MONDAY...A WEAK COLD FRONT WILL CROSS INTO THE FA FROM CANADA. HAVE SMALL POPS IN THE AFTERNOON IN RESPONSE TO SHORT WAVE ENERGY INTERACTING WITH THE FRONT TO POSSIBLY GENERATE THUNDERSTORMS. THE FRONT WILL CROSS THE REST OF THE FA MONDAY NIGHT. MOISTURE IS LIMITED AND HAVE SMALL POPS IN NW WI FOR ANY STORMS. RIDGING RETURNS FOR TUESDAY AND TUESDAY NIGHT. BY WEDNESDAY...A WARM FRONT IS PROGGED TO LIFT NWD INTO THE FA FROM THE SW. MEANWHILE...AN UPPER LEVEL SHORT WAVE DROPS OUT OF CANADA. THESE FEATURES WARRANT A SMALL POP. MOISTURE IS LIMITED AHEAD OF THE FRONT AND THAT IS WHERE THESE STORMS ARE EXPECTED TO DEVELOP AND HAVE SMALL POPS. A STRONG CUT OFF LOW WILL MOVE ACROSS SOUTH CENTRAL CANADA WEDNESDAY NIGHT. THIS PUSHES A SFC LOW AND STRONG COLD FRONT THROUGH THE FA. GFS AND ECMWF DISAGREE ON TIMING AND OVERALL COVERAGE SO CHANCE POPS USED. THE UPPER LOW CONTINUES TO MOVE SEWD AND GENERATE ADDITIONAL PCPN AND MAINTAINED POPS IN THE PATH OF THE LOW. LINGERED POPS THURSDAY NIGHT IN THE FAR EASTERN WI FA FOR AN LINGERING STORMS AS THE UPPER LOW DEPARTS. RIDGING RETURNS FOR FRIDAY. AVIATION...06Z ISSUANCE WIDESPREAD SHOWERS AND THUNDERSTORMS CURRENTLY LOCATED OVER THE REGION WILL GRADUALLY EXIT TO THE EAST THROUGH 12Z. EXPECT VARIABLE WIND GUSTS TO 30 KT AND MVFR/IFR CONDITIONS IN ANY OF THESE STORMS. WEST TO NORTHWEST SURFACE WINDS AND VFR CONDITIONS WILL PREVAIL THROUGH MID-DAY SATURDAY...WITH SCATTERED RAIN SHOWERS AND CEILINGS AROUND 4-6 KFT MAINLY AFTER 20Z. && .POINT TEMPS/POPS... DLH 77 55 75 55 / 40 20 10 0 INL 75 47 76 56 / 60 40 10 0 BRD 76 55 76 55 / 20 10 10 0 HYR 79 54 75 53 / 50 10 10 0 ASX 81 58 76 56 / 50 10 10 0 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...EOM LONG TERM....GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS DULUTH MN
631 AM CDT SAT AUG 4 2012 .AVIATION...12Z TAFS. FIRST FRONTAL BOUNDARY IS MOVING THROUGH FA ATTM. A FEW SHOWERS WILL OCCUR IN THE VCNTY OF THE FRONT. LATER TODAY...THE SECOND FRONT WILL BEGIN TO CROSS THE AREA WITH ADDITIONAL SHOWERS AND POSSIBLY A THUNDERSTORM. A MIX OF MVFR/IFR CIGS WITH THE FIRST FRONT UNTIL AROUND 15Z THEN AN IMPROVEMENT TO VFR. WITH THE SECOND FRONT...CIGS WILL DROP BACK INTO THE MVFR WITH VCSH AT MOST SITES FROM 18Z TO 00Z. CIGS IMPROVE TO VFR WITH THE DEPARTURE OF THE FRONT AND DRIER AIR ARRIVING WITH HIGH PRESSURE AFTER 06Z. && .PREV DISCUSSION... /ISSUED 323 AM CDT SAT AUG 4 2012/ SHORT TERM...THROUGH SUNDAY. CONVECTIVE SYSTEM WILL EXIT THE CWA OVER THE CWA IN THE NEXT 2 TO 3 HOURS. GUSTY WINDS...30-45 MPH AND SOME HAIL WILL BE POSSIBLE IN SPOTS WITH THIS LINE. THE FRONTAL BOUNDARY WAS STILL WEST OF THE CWA...AND SHOULD REACH OUR EASTERN MN ZONES BY 12Z...AND EXIT THE EASTERN CWA BY MID AFTERNOON. THE 925MB BOUNDARY WILL TAKE A BIT LONGER TO EXIT...AND IS FORECAST TO BE THROUGH THE ARROWHEAD AND OUR EASTERN WI COUNTIES AT 18Z. ADDITIONAL SHOWERS AND STORMS WERE FIRING IN SOUTHERN MINNESOTA/SOUTHEAST SOUTH DAKOTA ALONG AND AHEAD OF THE FRONT. UPPER WAVE WAS ALSO MOVING THROUGH THE DAKOTAS...WHICH WILL AID IN ADDITIONAL LIFT. POPS ARE A BIT TRICKY THIS MORNING. WE HAVE THEM HIGHEST IN THE EAST...AND WENT DRY IN THE FAR WEST. WE`LL KEEP AN EYE ON THE ACTIVITY IN SOUTH DAKOTA AND MAY HAVE TO INCLUDE A POP IN PORTIONS OF THE WEST-SOUTHWEST THIS MORNING IF THAT ACTIVITY PERSISTS OR EXPANDS. HIGH RES WRF AND HRRR SHOW THIS FALLING APART AS IT MOVES EAST-NORTHEAST. THIS AFTERNOON SHOULD SEE THE HIGHER CHANCES FOR SHOWERS/STORMS IN THE NORTH CLOSER TO THE UPPER LOW AND COLDER TEMPS ALOFT. WE HAVE A CHANCE FOR SHOWERS AND STORMS ACROSS MOST ZONES...RANGING FROM SLIGHT TO LIKELY. SHOWERS WILL DIMINISH THROUGH THE EVENING...BUT WE KEPT A MENTION OF SHOWERS ALL NIGHT IN THE ARROWHEAD IN AREA OF HIGHEST MOISTURE/AND NEAREST THE UPPER LOW. IT SHOULD BE DRY SUNDAY WITH HIGH PRESSURE BUILDING IN. TEMPERATURES TODAY AND SUNDAY FOR MOST AREAS WILL BE IN THE SEVENTIES. EXPECT LOWS TONIGHT TO DROP INTO THE UPPER FORTIES IN THE TRADITIONALLY COLDER SPOTS...WITH 50 TO 55 ELSEWHERE. LONG TERM...SUNDAY NIGHT THROUGH FRIDAY. SFC RIDGING COVERS THE FA SUNDAY NIGHT. ON MONDAY...A WEAK COLD FRONT WILL CROSS INTO THE FA FROM CANADA. HAVE SMALL POPS IN THE AFTERNOON IN RESPONSE TO SHORT WAVE ENERGY INTERACTING WITH THE FRONT TO POSSIBLY GENERATE THUNDERSTORMS. THE FRONT WILL CROSS THE REST OF THE FA MONDAY NIGHT. MOISTURE IS LIMITED AND HAVE SMALL POPS IN NW WI FOR ANY STORMS. RIDGING RETURNS FOR TUESDAY AND TUESDAY NIGHT. BY WEDNESDAY...A WARM FRONT IS PROGGED TO LIFT NWD INTO THE FA FROM THE SW. MEANWHILE...AN UPPER LEVEL SHORT WAVE DROPS OUT OF CANADA. THESE FEATURES WARRANT A SMALL POP. MOISTURE IS LIMITED AHEAD OF THE FRONT AND THAT IS WHERE THESE STORMS ARE EXPECTED TO DEVELOP AND HAVE SMALL POPS. A STRONG CUT OFF LOW WILL MOVE ACROSS SOUTH CENTRAL CANADA WEDNESDAY NIGHT. THIS PUSHES A SFC LOW AND STRONG COLD FRONT THROUGH THE FA. GFS AND ECMWF DISAGREE ON TIMING AND OVERALL COVERAGE SO CHANCE POPS USED. THE UPPER LOW CONTINUES TO MOVE SEWD AND GENERATE ADDITIONAL PCPN AND MAINTAINED POPS IN THE PATH OF THE LOW. LINGERED POPS THURSDAY NIGHT IN THE FAR EASTERN WI FA FOR AN LINGERING STORMS AS THE UPPER LOW DEPARTS. RIDGING RETURNS FOR FRIDAY. AVIATION...06Z ISSUANCE WIDESPREAD SHOWERS AND THUNDERSTORMS CURRENTLY LOCATED OVER THE REGION WILL GRADUALLY EXIT TO THE EAST THROUGH 12Z. EXPECT VARIABLE WIND GUSTS TO 30 KT AND MVFR/IFR CONDITIONS IN ANY OF THESE STORMS. WEST TO NORTHWEST SURFACE WINDS AND VFR CONDITIONS WILL PREVAIL THROUGH MID-DAY SATURDAY...WITH SCATTERED RAIN SHOWERS AND CEILINGS AROUND 4-6 KFT MAINLY AFTER 20Z. && .POINT TEMPS/POPS... DLH 77 55 75 55 / 20 20 10 0 INL 75 47 76 56 / 60 40 10 0 BRD 76 55 76 55 / 20 10 10 0 HYR 79 54 75 53 / 40 10 10 0 ASX 81 58 76 56 / 40 10 10 0 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ AVIATION...GSF
AREA FORECAST DISCUSSION
NWS DULUTH MN
323 AM CDT SAT AUG 4 2012 .SHORT TERM...THROUGH SUNDAY. CONVECTIVE SYSTEM WILL EXIT THE CWA OVER THE CWA IN THE NEXT 2 TO 3 HOURS. GUSTY WINDS...30-45 MPH AND SOME HAIL WILL BE POSSIBLE IN SPOTS WITH THIS LINE. THE FRONTAL BOUNDARY WAS STILL WEST OF THE CWA...AND SHOULD REACH OUR EASTERN MN ZONES BY 12Z...AND EXIT THE EASTERN CWA BY MID AFTERNOON. THE 925MB BOUNDARY WILL TAKE A BIT LONGER TO EXIT...AND IS FORECAST TO BE THROUGH THE ARROWHEAD AND OUR EASTERN WI COUNTIES AT 18Z. ADDITIONAL SHOWERS AND STORMS WERE FIRING IN SOUTHERN MINNESOTA/SOUTHEAST SOUTH DAKOTA ALONG AND AHEAD OF THE FRONT. UPPER WAVE WAS ALSO MOVING THROUGH THE DAKOTAS...WHICH WILL AID IN ADDITIONAL LIFT. POPS ARE A BIT TRICKY THIS MORNING. WE HAVE THEM HIGHEST IN THE EAST...AND WENT DRY IN THE FAR WEST. WE`LL KEEP AN EYE ON THE ACTIVITY IN SOUTH DAKOTA AND MAY HAVE TO INCLUDE A POP IN PORTIONS OF THE WEST-SOUTHWEST THIS MORNING IF THAT ACTIVITY PERSISTS OR EXPANDS. HIGH RES WRF AND HRRR SHOW THIS FALLING APART AS IT MOVES EAST-NORTHEAST. THIS AFTERNOON SHOULD SEE THE HIGHER CHANCES FOR SHOWERS/STORMS IN THE NORTH CLOSER TO THE UPPER LOW AND COLDER TEMPS ALOFT. WE HAVE A CHANCE FOR SHOWERS AND STORMS ACROSS MOST ZONES...RANGING FROM SLIGHT TO LIKELY. SHOWERS WILL DIMINISH THROUGH THE EVENING...BUT WE KEPT A MENTION OF SHOWERS ALL NIGHT IN THE ARROWHEAD IN AREA OF HIGHEST MOISTURE/AND NEAREST THE UPPER LOW. IT SHOULD BE DRY SUNDAY WITH HIGH PRESSURE BUILDING IN. TEMPERATURES TODAY AND SUNDAY FOR MOST AREAS WILL BE IN THE SEVENTIES. EXPECT LOWS TONIGHT TO DROP INTO THE UPPER FORTIES IN THE TRADITIONALLY COLDER SPOTS...WITH 50 TO 55 ELSEWHERE. .LONG TERM...SUNDAY NIGHT THROUGH FRIDAY. SFC RIDGING COVERS THE FA SUNDAY NIGHT. ON MONDAY...A WEAK COLD FRONT WILL CROSS INTO THE FA FROM CANADA. HAVE SMALL POPS IN THE AFTERNOON IN RESPONSE TO SHORT WAVE ENERGY INTERACTING WITH THE FRONT TO POSSIBLY GENERATE THUNDERSTORMS. THE FRONT WILL CROSS THE REST OF THE FA MONDAY NIGHT. MOISTURE IS LIMITED AND HAVE SMALL POPS IN NW WI FOR ANY STORMS. RIDGING RETURNS FOR TUESDAY AND TUESDAY NIGHT. BY WEDNESDAY...A WARM FRONT IS PROGGED TO LIFT NWD INTO THE FA FROM THE SW. MEANWHILE...AN UPPER LEVEL SHORT WAVE DROPS OUT OF CANADA. THESE FEATURES WARRANT A SMALL POP. MOISTURE IS LIMITED AHEAD OF THE FRONT AND THAT IS WHERE THESE STORMS ARE EXPECTED TO DEVELOP AND HAVE SMALL POPS. A STRONG CUT OFF LOW WILL MOVE ACROSS SOUTH CENTRAL CANADA WEDNESDAY NIGHT. THIS PUSHES A SFC LOW AND STRONG COLD FRONT THROUGH THE FA. GFS AND ECMWF DISAGREE ON TIMING AND OVERALL COVERAGE SO CHANCE POPS USED. THE UPPER LOW CONTINUES TO MOVE SEWD AND GENERATE ADDITIONAL PCPN AND MAINTAINED POPS IN THE PATH OF THE LOW. LINGERED POPS THURSDAY NIGHT IN THE FAR EASTERN WI FA FOR AN LINGERING STORMS AS THE UPPER LOW DEPARTS. RIDGING RETURNS FOR FRIDAY. && .AVIATION...06Z ISSUANCE WIDESPREAD SHOWERS AND THUNDERSTORMS CURRENTLY LOCATED OVER THE REGION WILL GRADUALLY EXIT TO THE EAST THROUGH 12Z. EXPECT VARIABLE WIND GUSTS TO 30 KT AND MVFR/IFR CONDITIONS IN ANY OF THESE STORMS. WEST TO NORTHWEST SURFACE WINDS AND VFR CONDITIONS WILL PREVAIL THROUGH MID-DAY SATURDAY...WITH SCATTERED RAIN SHOWERS AND CEILINGS AROUND 4-6 KFT MAINLY AFTER 20Z. && .POINT TEMPS/POPS... DLH 77 55 75 55 / 20 20 10 0 INL 75 47 76 56 / 60 40 10 0 BRD 76 55 76 55 / 20 10 10 0 HYR 79 54 75 53 / 40 10 10 0 ASX 81 58 76 56 / 40 10 10 0 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...MELDE LONG TERM....GSF AVIATION...GRANING
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
554 PM CDT Sat Aug 4 2012 ...UPDATED AVIATION DISCUSSION... .DISCUSSION... Well, looks like we have to wait for rain again. At least in many areas this seems to be the appropriate theme for today, as yet another shortwave/MCV race ahead of the surface front this morning effectively shoving stabilizing much of northern Missouri and allowing a weak surface trough to sneak southeast into Missouri and Kansas. Currently the primary surface trough stretches from Ottumwa, IA southwest through Kansas City and further south towards Wichita, KS. A continued stream of mid-level strato-cu has suppressed the warm surface temperatures in the extreme southern CWA with 88D radar composites indicating northward extent of surface warm front is just south of the Pleasant Hill office. For tonight, highest convective potential remains along our southern and southeastern tier of counties and again in areas near Kirksville as mid-level shortwave currently moving through central Kansas reaches the area after 4pm. HRRR and RAP suggest widely scattered convection forming along the differential heating axis in the southern CWA after 4pm with this convection slowly sinking southeast this evening. Instability and shear plots indicate multi-cell clusters would be the preferred storm type with downburst winds the main threat. Elsewhere in areas further north, scattered high based showers or sprinkles may the result of the weak shortwave and 850 trough passing through the area this evening. Dew points will remain elevated through the evening as true front is just arriving into the northwest corner of the CWA. Will linger chc pops across the southern CWA through the overnight hours, as 850 mb front stalls. Weak 850:700 mb frontogenesis tied with the right entrance region of the upr jet may be enough forcing for west to east ling of elevated convection through early Sunday morning in west central into central MO. Sunday-Monday: Surface high pressure will drift southeast into the region by Sunday morning. North to northeast winds will prevail through the daytime hours with temperatures struggling to reach the middle 80s in northern MO and barely hitting 90 towards east central Kansas and central MO. This surface ridge will quickly slide into the Ohio river valley by Monday allowing winds to take a more southerly track. The resultant bump in low-level temperatures will push daytime highs in the lower to middle 90s. Tuesday-Friday: The overall longwave pattern will feature a building ridge over the western CONUS and broad northwesterly flow over the central and eastern US. GFS/EC/GEM indicate a weak disturbance in the NW flow pattern moving through as we reach Tuesday night into Wednesday. Always hard to time these shortwaves and their impact especially considering the lack of boundary layer moisture. However one could justify at least a slight chance for precip. Temperatures will run near or slightly above normal through the end of the week. 31 && .AVIATION... VFR conditions expected for all terminals through the forecast period. Widely scattered showers continue to move across the area this evening but should push east of the TAF sites in a few hours. Otherwise, light north winds are expected to persist through tomorrow. Deroche && .EAX WATCHES/WARNINGS/ADVISORIES... MO...HEAT ADVISORY until 8 PM CDT this evening FOR MOZ040-043>046-053- 054. KS...HEAT ADVISORY until 8 PM CDT this evening FOR KSZ057-060. && $$ WFO EAX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
323 PM CDT Sat Aug 4 2012 .DISCUSSION... Well, looks like we have to wait for rain again. At least in many areas this seems to be the appropriate theme for today, as yet another shortwave/MCV race ahead of the surface front this morning effectively shoving stabilizing much of northern Missouri and allowing a weak surface trough to sneak southeast into Missouri and Kansas. Currently the primary surface trough stretches from Ottumwa, IA southwest through Kansas City and further south towards Wichita, KS. A continued stream of mid-level strato-cu has suppressed the warm surface temperatures in the extreme southern CWA with 88D radar composites indicating northward extent of surface warm front is just south of the Pleasant Hill office. For tonight, highest convective potential remains along our southern and southeastern tier of counties and again in areas near Kirksville as mid-level shortwave currently moving through central Kansas reaches the area after 4pm. HRRR and RAP suggest widely scattered convection forming along the differential heating axis in the southern CWA after 4pm with this convection slowly sinking southeast this evening. Instability and shear plots indicate multi-cell clusters would be the preferred storm type with downburst winds the main threat. Elsewhere in areas further north, scattered high based showers or sprinkles may the result of the weak shortwave and 850 trough passing through the area this evening. Dew points will remain elevated through the evening as true front is just arriving into the northwest corner of the CWA. Will linger chc pops across the southern CWA through the overnight hours, as 850 mb front stalls. Weak 850:700 mb frontogenesis tied with the right entrance region of the upr jet may be enough forcing for west to east ling of elevated convection through early Sunday morning in west central into central MO. Sunday-Monday: Surface high pressure will drift southeast into the region by Sunday morning. North to northeast winds will prevail through the daytime hours with temperatures struggling to reach the middle 80s in northern MO and barely hitting 90 towards east central Kansas and central MO. This surface ridge will quickly slide into the Ohio river valley by Monday allowing winds to take a more southerly track. The resultant bump in low-level temperatures will push daytime highs in the lower to middle 90s. Tuesday-Friday: The overall longwave pattern will feature a building ridge over the western CONUS and broad northwesterly flow over the central and eastern US. GFS/EC/GEM indicate a weak disturbance in the NW flow pattern moving through as we reach Tuesday night into Wednesday. Always hard to time these shortwaves and their impact especially considering the lack of boundary layer moisture. However one could justify at least a slight chance for precip. Temperatures will run near or slightly above normal through the end of the week. 31 && .AVIATION... For the 18Z TAFs...Quick progression of a cold front across Missouri has resulted in winds at the terminals turning to the northeast in the wake of some scattered convection this morning. Further thunderstorm development might occur across northern and central Missouri this afternoon, but at this time thoughts are this activity will be east of all the terminals. As a result, only issue to watch for looks to be the slightly gusty north winds this afternoon in the post-frontal environment. Winds should stay from the north overnight, with VFR skies prevailing. Cutter && .EAX WATCHES/WARNINGS/ADVISORIES... MO...HEAT ADVISORY until 8 PM CDT this evening FOR MOZ040-043>046-053- 054. KS...HEAT ADVISORY until 8 PM CDT this evening FOR KSZ057-060. && $$ WFO EAX
AREA FORECAST DISCUSSION...CORRECTED
NWS HASTINGS NE
406 PM CDT SAT AUG 4 2012 .SHORT TERM...THROUGH SUNDAY AFTERNOON. PRIMARY ISSUES THROUGH THE NEXT 24 HOURS INCLUDE TIMING THE THE LAST FEW HOURS OF LINGERING ISOLATED/SCATTERED LIGHT PRECIP THROUGH LATE AFTERNOON...FOLLOWED BY JUST HOW COOL WILL IT GET TONIGHT. 19Z OBJECTIVE SURFACE ANALYSIS CENTERS A 1022MB HIGH OVER MT/WY...WITH THE RIDGE AXIS EXTENDING DOWN INTO WESTERN NEB. THE MUCH-AWAITED STRONGEST COLD FRONT WE HAVE SEEN AWHILE HAS PUSHED WELL OFF TO THE SOUTH AND EAST...NOW ALIGNED ALONG FROM EASTERN IA TO THE TX PANHANDLE. ALTHOUGH MID AFTERNOON WINDS CONTINUE TO GUST OVER 20 MPH IN MANY AREAS FROM THE NORTH/NORTHWEST...THEY ARE STARTING A GRADUAL DECLINE AS THE STRONGEST PRESSURE RISES SLIDE SOUTHEAST WITH THE FRONT. RADAR IMAGERY AND VISIBLE SATELLITE AROUND 1930Z GENERALLY CONFIRM THE EARLIER EXPECTATIONS OF ISOLATED/SCATTERED MAINLY LIGHT HIGH BASED RAIN SHOWERS STARTING TO INCREASE IN COVERAGE A BIT ACROSS THE SOUTHERN 1/2 OF THE CWA...ALTHOUGH NO LIGHTNING STRIKES HAVE YET BEEN DETECTED. WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA REVEAL A SEASONABLY STRONG MID LEVEL VORT MAX TRACKING EAST NEAR FAR NORTHERN MN...WITH THE 500MB SHORTWAVE AXIS TRAILING SOUTHWEST TO THE LOCAL AREA...WHILE RIDGING DOMINATES THE SOUTH CENTRAL AND WEST CENTRAL CONUS. TEMP WISE THIS AFTERNOON...STILL ANTICIPATING SOME LATE DAY SUNSHINE TO BOOST AT LEAST MUCH OF THE NORTHWEST 1/2 OF THE CWA INTO THE LOW 80S...BUT THE JURY IS STILL OUT ON WHETHER PARTS OF THE SOUTHEAST...MAYBE EVEN HASTINGS...WILL EVEN MAKE IT TO 80 GIVEN THE EXTENSIVE MID CLOUDS LINGERING LONGER. SEASONABLY DRY AIR IN THE FORM OF MID 40S-LOW 50S DEWPOINTS CONTINUE TO INVADE MUCH OF THE CWA FROM THE NORTHWEST...ALTHOUGH SOME UPPER 50S ARE STILL HANGING ON IN THE SOUTHEAST. STARTING OFF WITH THE NEXT FEW HOURS THROUGH 00Z...JUST MADE A LAST MINUTE DECISION TO PULL THUNDER MENTION ALTOGETHER...AS LATEST HOURLY MESOANALYSIS AND RAP INSTABILITY PROGS INDICATE BARELY EVEN 100 J/KG MUCAPE REMAINING IN THE FAR SOUTHEAST COUNTIES...AND ONGOING LIGHT SHOWERS HAVE NOT EXHIBITED DETECTABLE LIGHTNING AT ALL OVER THE PAST FEW HOURS. THESE LINGERING SHOWERS OVER THE NEXT FEW HOURS WILL MAINLY AFFECT LIMITED AREAS SOUTHEAST OF A LINE FROM HEBRON-STOCKTON...AND WILL CARRY ISOLATED/SCATTERED SHOWER WORDING FOR JUST A FEW MORE HOURS TO COVER THEM. THIS LINGERING PRECIP IS CLEARLY TIED TO A QUICKLY DEPARTING MID LEVEL CONVERGENCE/FRONTOGENETIC ZONE EVIDENT AT 700MB. GETTING TO THE OFFICIAL NIGHT PERIOD 00Z-12Z...BY THE START OF THE EVENING ANTICIPATE CONSIDERABLE CLEAR SKIES NEARLY CWA-WIDE...AS THE BACK EDGE OF THE PRIMARY MID DECK AND ASSOCIATED SHOWERS/POSSIBLE WEAK STORMS SHOULD BE JUST OFF TO THE SOUTH/EAST OF THE CWA BY THEN. AS A RESULT...HAVE ESSENTIALLY ZERO POPS THROUGH THE NIGHT AREA- WIDE...AS THE TRAILING SOUTHWEST PORTION OF THE POTENT MID LEVEL WAVE CONTINUES EXITING STAGE RIGHT...REACHING AN AXIS FROM NORTHERN WI TO IL BY 12Z. IN ITS WAKE...A PLEASANT AND EVEN SEASONABLY COOL NIGHT WILL SETTLE INTO THE CENTRAL PLAINS. AT THE SURFACE...NORTH BREEZES WILL REALLY LIGHTEN BY SUNSET...AND BECOME NEARLY CALM THROUGH THE NIGHT IN SOME AREAS AS A 1023MB HIGH PRESSURE AXIS CENTERS ITSELF DIRECTLY OVER THE AREA. THE COMBINATION OF THE INVADING DRY AIR...CLEARING SKIES AND LIGHT BREEZES SHOULD SET THE STAGE FOR A RATHER COOL NIGHT BY EARLY AUG STANDARDS. LEANED TOWARD THE LOWER END OF 12Z MET/MAV GUIDANCE FOR LOWS...WHICH RESULTED IN LOWERING PREVIOUS FORECAST BY 2-4 DEGREES MAINLY IN THE FAR NORTHWEST AND SOUTHERN COUNTIES. THEREFORE...AM NOW ADVERTISING LOW-MID 50S ALL AREAS...WITH TYPICAL COOLER SPOTS SUCH AS ORD AND THE PLATTE VALLEY OF WESTERN DAWSON COUNTY VERY POSSIBLY TAGGING UPPER 40S. FOR THIS TIME OF YEAR...DEFINITELY LIGHT JACKET WEATHER FOR THOSE OUT AND ABOUT LATE TONIGHT/EARLY SUNDAY MORNING. FOR THE SUNDAY DAYTIME 12Z-00Z PERIOD...LITERALLY KEPT POPS ZEROED OUT CWA-WIDE...AS A BANNER DAY WITH VERY LITTLE...IF ANY CLOUDS IS FORECAST. IN THE MID-UPPER LEVELS...THE DEPARTING SHORTWAVE WILL REACH ALL THE WAY TO THE EASTERN GREAT LAKES BY LATE AFTERNOON...WHILE THE SOUTHERN CONUS 500MB RIDGE AXIS EXPANDS NORTH AND WEST IN COVERAGE A BIT...BECOMING CENTERED FROM CO/UT TO OK/NORTHERN TX. THIS WILL LEAVE THE CWA IN FAIRLY LIGHT AND VERY DRY WEST-NORTHWEST MID LEVEL FLOW. AT THE SURFACE...THE AFOREMENTIONED RIDGE AXIS WILL START OUT CENTERED OVER THE AREA...BUT GRADUALLY SLIDE EAST TO NEAR THE MO RIVER BY LATE AFTERNOON. AS THE HIGH EDGES EAST...LIGHT SOUTHERLY BREEZES WILL GRADUALLY OVERTAKE MUCH OF THE CWA FROM WEST TO EAST...EVENTUALLY REACHING INTO THE 10-15 MPH RANGE IN FAR WESTERN COUNTIES...BUT REMAINING VERY LIGHT/NEAR CALM ALL DAY IN THE FAR EAST NEAR HWY 81. ALTHOUGH THE LIGHT BREEZES/LACK OF MIXING WILL WORK AGAINST MUCH OF A WARMUP OVER TODAY...PLENTIFUL SUNSHINE AND RELATIVELY DRY AIR WILL WORK IN FAVOR OF IT. AS HAS BEEN THE CASE FOR SEVERAL WEEKS NOW...NUMERICAL GUIDANCE HAS PROVEN DIFFICULT TO EMPLOY...WITH THE MET AVERAGING TOO WARM AND THE MAV TOO COOL. OVERALL THOUGH...WILL LEAN TOWARD THE WARMER END OF GUIDANCE...AND ESSENTIALLY JUST BUMPED UP THE PREVIOUS FORECAST 1 DEGREE. THIS YIELDS NEAR NORMAL HIGHS OF 86-88 MOST AREAS...AND 90-92 IN KS ZONES AND FURNAS COUNTY AREA. LOWERED DEWPOINTS A BIT FROM PREVIOUS FORECAST AS WELL...WITH ONLY MID-UPPER 40S SOUTHWEST AND LOW-MID 50S SOUTHEAST. ALTHOUGH RELATIVE HUMIDITY VALUES COULD DROP CLOSE TO THE 20 PERCENT CRITICAL FIRE WEATHER THRESHOLD IN A FEW FAR SOUTHWEST COUNTIES...WINDS SPEEDS WILL FALL WELL SHORT OF FIRE WEATHER CRITERIA. .LONG TERM...SUNDAY NIGHT THROUGH SATURDAY. MODELS NOT IN TOO BAD OF AGREEMENT TO START OFF THE LONG TERM PERIOD...SHOWING SUNDAY EVENING REMAINING UNDER ZONAL/WEAK NORTHWESTERLY FLOW IN THE UPPER LEVELS...A RESULT OF A BROAD HIGH PRESSURE IN PLACE ACROSS THE SCENTRAL/SWRN CONUS AND A TROUGH SHIFTING TOWARD THE EAST COAST. DURING THE OVERNIGHT HOURS...THE FLOW DOES AMPLIFY SOME AS ANOTHER TROUGH IS MAKING ITS WAY TOWARD THE WEST COAST...BUT NO NOTABLE DISTURBANCES LOOK TO MOVE THROUGH AND DECIDED TO KEEP THE FORECAST DRY. HOWEVER...MODELS DO SHOW THE SFC/LOWER LEVEL WINDS REMAINING S/SWRLY OVERNIGHT...WITH INCREASING VALUES OF ELEVATED INSTABILITY SHIFTING NORTH INTO THE REGION AS A STRONGER /30-35KT OR SO/ LLJ DEVELOPS...MAINLY ACROSS THE HIGH PLAINS REGION. THE EDGE OF THIS LLJ/INSTABILITY AXIS DOES LIE OVER THE WRN PORTIONS OF THE CWA...AND MAY HAVE TO KEEP AN EYE ON THIS AREA FOR THE POTENTIAL FOR PERHAPS SOME LIGHT PRECIP /BUT FORECAST SOUNDINGS ARE PRETTY DRY IN THE LOWER LEVELS/...OR A LITTLE MORE IN THE WAY OF CLOUD COVER. INTO MONDAY/MONDAY NIGHT...THE MAIN STORY LIES WITH THE ARRIVAL OF A MID/UPPER LEVEL WAVE...ASSOCIATED WITH A LOW PRESSURE SYSTEM LOCATED UP NEAR THE HUDSON BAY. KEPT THE DAYTIME HOURS ON MONDAY DRY...THOUGH A LITTLE MORE UNCERTAINTY ARISES TOWARD THE LATE AFTERNOON HOURS...WITH THE ACCOMPANYING SURFACE FRONTAL BOUNDARY LOOKS TO BE KNOCKING ON THE DOOR OF THE FAR NW CORNER OF THE CWA. DID RAISE POPS A BIT DURING THE EVENING/OVERNIGHT HOURS ACROSS THE N/NWRN PORTIONS OF THE CWA...BUT DIDNT MAKE MUCH CHANGE FURTHER SOUTH. AHEAD OF THE FRONT ON MONDAY...EXPECTING INCREASED SOUTHERLY WINDS...LIKELY A BIT GUSTY DURING THE AFTERNOON...AND WARMER TEMPERATURES WITH HIGHS FORECAST TO REACH INTO THE MID/UPPER 90S FOR MUCH/IF NOT ALL OF THE CWA. CONDITIONS DURING THE AFTERNOON HOURS SHOULD REMAIN BELOW CRITICAL FIRE LEVELS...RHS COULD DROP INTO THE LOWER/MID 20S ACROSS THE SOUTH...BUT SUSTAINED WIND SPEEDS ARE EXPECTED TO REMAIN <20 MPH...THOUGH GUSTS COULD AT TIMES COME CLOSE TO 25 MPH. WILL BE SOMETHING TO KEEP AN EYE ON IF MODELS HAPPEN TO TREND UP WINDS/TREND DOWN DPS. KEPT SOME LINGERING POPS IN DURING THE DAY ON TUESDAY...MAINLY ACROSS THE SRN HALF OF THE CWA...IN CLOSER PROXIMITY TO WHERE THE SFC BOUNDARY IS EXPECTED TO BE /SOMEWHERE NEAR OR SOUTH OF THE NEB AND KS STATE LINE/. CONFIDENCE NOT THE HIGHEST...AS THE PLACEMENT OF THE FRONT WILL BE DEPENDENT ON HOW THINGS PAN OUT MONDAY NIGHT. WITH MOST OF THE CWA LOOKING TO BE ON THE NORTH SIDE OF THAT BOUNDARY...MORE EASTERLY WINDS EXPECTED TO BE IN PLACE...AND FORECAST HIGHS ARE A TOUCH COOLER THAN MONDAY...MORE IN THE LOWER/MID 90S. BY 00Z WEDNESDAY...THE UPPER LEVEL PATTERN ACROSS THE CONUS HAS BECOME MORE AMPLIFIED...WITH MORE SOLIDLY NORTHWESTERLY FLOW IN PLACE ACROSS THE REGION AS THE RIDGE AXIS EXTENDS FROM THE DESERT SW THROUGH THE ROCKIES AND INTO CANADA. THE NOSE OF AN UPPER LEVEL JET STREAK ROUNDING THE TOP OF THE RIDGE AXIS IS EXPECTED TO SHIFT INTO THE REGION FROM THE NW...BRINGING THE POTENTIAL FOR MORE PRECIPITATION TUESDAY EVENING/OVERNIGHT. SIMILAR TO MONDAY/MONDAY NIGHT...WHILE THERE IS INSTABILITY IN PLACE ACROSS THE REGION...OVERALL DEEP LAYER SHEAR IS CERTAINLY NOT OUTSTANDING...GENERALLY TOPPING OUT IN THE 25-30 KTS RANGE...SO WHILE SOME THUNDERSTORMS COULD BE ON THE STRONGER SIDE...NOT EXPECTING SEVERE WEATHER AT THIS POINT. INTO WEDNESDAY...MODELS CONTINUE TO SHOW THE NOSE OF THIS UPPER LEVEL JET IN THE AREA...AND DECIDED TO KEEP SOME LINGERING POPS IN THE AREA...BUT CONFIDENCE IN CHANCES STICKING AROUND LONGER THAN PERHAPS A FEW HOURS IN THE MORNING NOT EXACTLY HIGH. THAT LOWER CONFIDENCE CONTINUES RIGHT ON THROUGH THE REMAINDER OF THE LONG TERM PERIOD. THE UPPER LEVEL PATTERN REMAINS NORTHWESTERLY ACROSS THE REGION WITH THE RIDGE STAYING IN PLACE OVER THE CENTRAL ROCKIES...AND KEPT THE FORECAST DRY AT THIS POINT...WITH MODELS SHOWING SOME DIFFERENCES WITH DISTURBANCES PASSING TO THE EAST OF THE CWA...AND WHETHER WE SEE ANY PRECIP AS RESULT. WITH THE RIDGE/WARMEST AIR REMAINING OFF TO THE WEST OF THE CWA...AND THE POTENTIAL FOR AN ADDITIONAL FRONTAL PASSAGE...NOTABLY HIGHER TEMPERATURES ARE NOT EXPECTED...WITH FORECAST HIGHS RANGING FROM ROUGHLY THE MID 90S WED/THUR TO THE MID 80S TO LOWER 90S FRI/SAT. && .PREV DISCUSSION... /ISSUED 1155 AM CDT SAT AUG 4 2012/ AVIATION...18Z KGRI TAF. VFR CEILING/VISIBILITY ARE FORECAST THROUGH THE PERIOD. ESSENTIALLY CLEAR SKIES WILL DOMINATE THE AREA THROUGH THE MAJORITY OF THE PERIOD...BUT FOR AT LEAST THE INITIAL 3-5 HOURS QUITE A BIT OF MID LEVEL CLOUD COVER WILL STREAM OVER...ALONG WITH JUST A SLIGHT CHANCE OF BRIEF PASSING SHOWERS...WHICH HAVE BEEN SUGGESTED WITH A VICINITY SHOWER MENTION. SURFACE BREEZES WILL REMAIN NORTHERLY THROUGH TONIGHT IN THE WAKE OF A SEASONABLY STRONG COLD FRONT. THE STRONGEST SPEEDS WITH GUST POTENTIAL TO AROUND 20KT WILL OCCUR DURING THE FIRST FEW HOURS OF THE PERIOD...BEFORE A STEADY SLACKENING OF SPEEDS COMMENCES. FROM SUNSET THROUGH MID-DAY SUNDAY...SPEEDS SHOULD AVERAGE UNDER 6KT AND BECOME A BIT VARIABLE IN DIRECTION WITH TIME. && .CLIMATE...TODAY/TONIGHT WILL LIKELY END UP BEING THE COOLEST DAY/NIGHT AT GRAND ISLAND AND HASTINGS IN 6.5 WEEKS. BASED ON FORECAST PROJECTIONS OVER THE NEXT FEW HOURS...THE CALENDAR DAY HIGH TEMPERATURE AT BOTH GRAND ISLAND AND HASTINGS WILL END UP SOMEWHERE BETWEEN 78-82 DEGREES...BUT IS GUARANTEED TO BE AT LEAST 78 BECAUSE THIS VALUE WAS REACHED SHORTLY AFTER MIDNIGHT BEFORE THE COLD FRONT INVADED. FOR GRAND ISLAND...A HIGH OF 79-82 DEGREES WOULD RESULT IN THE COOLEST DAILY HIGH SINCE JUNE 20TH...WHEN IT TOPPED OUT AT 79. FOR HASTINGS...A HIGH OF 78-79 DEGREES WOULD ALSO RESULT IN THE COOLEST DAY SINCE JUNE 20TH...WHEN IT REACHED 78. TURNING TO LOW TEMPERATURES TONIGHT...THE CURRENT FORECAST FOR BOTH GRAND ISLAND AND HASTINGS CALLS FOR 55. THIS IS ONLY 3 DEGREES ABOVE HASTINGS AUGUST 5TH RECORD LOW OF 52...AND 4 DEGREES ABOVE THE GRAND ISLAND RECORD LOW OF 51...BOTH SET IN 1994. ASSUMING IT DIPS TO AT LEAST 57 DEGREES OVERNIGHT...THIS WILL BE THE COOLEST LOW TEMP IN BOTH CITIES SINCE JUNE 21ST...WHEN GRAND ISLAND BOTTOMED OUT AT 52 AND HASTINGS 51. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM/AVIATION...PFANNKUCH LONG TERM...ADO
AREA FORECAST DISCUSSION
NWS HASTINGS NE
400 PM CDT SAT AUG 4 2012 .SHORT TERM...THROUGH SUNDAY AFTERNOON. PRIMARY ISSUES THROUGH THE NEXT 24 HOURS INCLUDE TIMING THE THE LAST FEW HOURS OF LINGERING ISOLATED/SCATTERED LIGHT PRECIP THROUGH LATE AFTERNOON...FOLLOWED BY JUST HOW COOL WILL IT GET TONIGHT. 19Z OBJECTIVE SURFACE ANALYSIS CENTERS A 1022MB HIGH OVER MT/WY...WITH THE RIDGE AXIS EXTENDING DOWN INTO WESTERN NEB. THE MUCH-AWAITED STRONGEST COLD FRONT WE HAVE SEEN AWHILE HAS PUSHED WELL OFF TO THE SOUTH AND EAST...NOW ALIGNED ALONG FROM EASTERN IA TO THE TX PANHANDLE. ALTHOUGH MID AFTERNOON WINDS CONTINUE TO GUST OVER 20 MPH IN MANY AREAS FROM THE NORTH/NORTHWEST...THEY ARE STARTING A GRADUAL DECLINE AS THE STRONGEST PRESSURE RISES SLIDE SOUTHEAST WITH THE FRONT. RADAR IMAGERY AND VISIBLE SATELLITE AROUND 1930Z GENERALLY CONFIRM THE EARLIER EXPECTATIONS OF ISOLATED/SCATTERED MAINLY LIGHT HIGH BASED RAIN SHOWERS STARTING TO INCREASE IN COVERAGE A BIT ACROSS THE SOUTHERN 1/2 OF THE CWA...ALTHOUGH NO LIGHTNING STRIKES HAVE YET BEEN DETECTED. WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA REVEAL A SEASONABLY STRONG MID LEVEL VORT MAX TRACKING EAST NEAR FAR NORTHERN MN...WITH THE 500MB SHORTWAVE AXIS TRAILING SOUTHWEST TO THE LOCAL AREA...WHILE RIDGING DOMINATES THE SOUTH CENTRAL AND WEST CENTRAL CONUS. TEMP WISE THIS AFTERNOON...STILL ANTICIPATING SOME LATE DAY SUNSHINE TO BOOST AT LEAST MUCH OF THE NORTHWEST 1/2 OF THE CWA INTO THE LOW 80S...BUT THE JURY IS STILL OUT ON WHETHER PARTS OF THE SOUTHEAST...MAYBE EVEN HASTINGS...WILL EVEN MAKE IT TO 80 GIVEN THE EXTENSIVE MID CLOUDS LINGERING LONGER. SEASONABLY DRY AIR IN THE FORM OF MID 40S-LOW 50S DEWPOINTS CONTINUE TO INVADE MUCH OF THE CWA FROM THE NORTHWEST...ALTHOUGH SOME UPPER 50S ARE STILL HANGING ON IN THE SOUTHEAST. STARTING OFF WITH THE NEXT FEW HOURS THROUGH 00Z...JUST MADE A LAST MINUTE DECISION TO PULL THUNDER MENTION ALTOGETHER...AS LATEST HOURLY MESOANALYSIS AND RAP INSTABILITY PROGS INDICATE BARELY EVEN 100 J/KG MUCAPE REMAINING IN THE FAR SOUTHEAST COUNTIES...AND ONGOING LIGHT SHOWERS HAVE NOT EXHIBITED DETECTABLE LIGHTNING AT ALL OVER THE PAST FEW HOURS. THESE LINGERING SHOWERS OVER THE NEXT FEW HOURS WILL MAINLY AFFECT LIMITED AREAS SOUTHEAST OF A LINE FROM HEBRON-STOCKTON...AND WILL CARRY ISOLATED/SCATTERED SHOWER WORDING FOR JUST A FEW MORE HOURS TO COVER THEM. THIS LINGERING PRECIP IS CLEARLY TIED TO A QUICKLY DEPARTING MID LEVEL CONVERGENCE/FRONTOGENETIC ZONE EVIDENT AT 700MB. GETTING TO THE OFFICIAL NIGHT PERIOD 00Z-12Z...BY THE START OF THE EVENING ANTICIPATE CONSIDERABLE CLEAR SKIES NEARLY CWA-WIDE...AS THE BACK EDGE OF THE PRIMARY MID DECK AND ASSOCIATED SHOWERS/POSSIBLE WEAK STORMS SHOULD BE JUST OFF TO THE SOUTH/EAST OF THE CWA BY THEN. AS A RESULT...HAVE ESSENTIALLY ZERO POPS THROUGH THE NIGHT AREA- WIDE...AS THE TRAILING SOUTHWEST PORTION OF THE POTENT MID LEVEL WAVE CONTINUES EXITING STAGE RIGHT...REACHING AN AXIS FROM NORTHERN WI TO IL BY 12Z. IN ITS WAKE...A PLEASANT AND EVEN SEASONABLY COOL NIGHT WILL SETTLE INTO THE CENTRAL PLAINS. AT THE SURFACE...NORTH BREEZES WILL REALLY LIGHTEN BY SUNSET...AND BECOME NEARLY CALM THROUGH THE NIGHT IN SOME AREAS AS A 1023MB HIGH PRESSURE AXIS CENTERS ITSELF DIRECTLY OVER THE AREA. THE COMBINATION OF THE INVADING DRY AIR...CLEARING SKIES AND LIGHT BREEZES SHOULD SET THE STAGE FOR A RATHER COOL NIGHT BY EARLY AUG STANDARDS. LEANED TOWARD THE LOWER END OF 12Z MET/MAV GUIDANCE FOR LOWS...WHICH RESULTED IN LOWERING PREVIOUS FORECAST BY 2-4 DEGREES MAINLY IN THE FAR NORTHWEST AND SOUTHERN COUNTIES. THEREFORE...AM NOW ADVERTISING LOW-MID 50S ALL AREAS...WITH TYPICAL COOLER SPOTS SUCH AS ORD AND THE PLATTE VALLEY OF WESTERN DAWSON COUNTY VERY POSSIBLY TAGGING UPPER 40S. FOR THIS TIME OF YEAR...DEFINITELY LIGHT JACKET WEATHER FOR THOSE OUT AND ABOUT LATE TONIGHT/EARLY SUNDAY MORNING. FOR THE SUNDAY DAYTIME 12Z-00Z PERIOD...LITERALLY KEPT POPS ZEROED OUT CWA-WIDE...AS A BANNER DAY WITH VERY LITTLE...IF ANY CLOUDS IS FORECAST. IN THE MID-UPPER LEVELS...THE DEPARTING SHORTWAVE WILL REACH ALL THE WAY TO THE EASTERN GREAT LAKES BY LATE AFTERNOON...WHILE THE SOUTHERN CONUS 500MB RIDGE AXIS EXPANDS NORTH AND WEST IN COVERAGE A BIT...BECOMING CENTERED FROM CO/UT TO OK/NORTHERN TX. THIS WILL LEAVE THE CWA IN FAIRLY LIGHT AND VERY DRY WEST-NORTHWEST MID LEVEL FLOW. AT THE SURFACE...THE AFOREMENTIONED RIDGE AXIS WILL START OUT CENTERED OVER THE AREA...BUT GRADUALLY SLIDE EAST TO NEAR THE MO RIVER BY LATE AFTERNOON. AS THE HIGH EDGES EAST...LIGHT SOUTHERLY BREEZES WILL GRADUALLY OVERTAKE MUCH OF THE CWA FROM WEST TO EAST...EVENTUALLY REACHING INTO THE 10-15 MPH RANGE IN FAR WESTERN COUNTIES...BUT REMAINING VERY LIGHT/NEAR CALM ALL DAY IN THE FAR EAST NEAR HWY 81. ALTHOUGH THE LIGHT BREEZES/LACK OF MIXING WILL WORK AGAINST MUCH OF A WARMUP OVER TODAY...PLENTIFUL SUNSHINE AND RELATIVELY DRY AIR WILL WORK IN FAVOR OF IT. AS HAS BEEN THE CASE FOR SEVERAL WEEKS NOW...NUMERICAL GUIDANCE HAS PROVEN DIFFICULT TO EMPLOY...WITH THE MET AVERAGING TOO WARM AND THE MAV TOO COOL. OVERALL THOUGH...WILL LEAN TOWARD THE WARMER END OF GUIDANCE...AND ESSENTIALLY JUST BUMPED UP THE PREVIOUS FORECAST 1 DEGREE. THIS YIELDS NEAR NORMAL HIGHS OF 86-88 MOST AREAS...AND 90-92 IN KS ZONES AND FURNAS COUNTY AREA. LOWERED DEWPOINTS A BIT FROM PREVIOUS FORECAST AS WELL...WITH ONLY MID-UPPER 40S SOUTHWEST AND LOW-MID 50S SOUTHEAST. ALTHOUGH RELATIVE HUMIDITY VALUES COULD DROP CLOSE TO THE 20 PERCENT CRITICAL FIRE WEATHER THRESHOLD IN A FEW FAR SOUTHWEST COUNTIES...WINDS SPEEDS WILL FALL WELL SHORT OF FIRE WEATHER CRITERIA. .LONG TERM...SUNDAY NIGHT THROUGH SATURDAY. MODELS NOT IN TOO BAD OF AGREEMENT TO START OFF THE LONG TERM PERIOD...SHOWING SUNDAY EVENING REMAINING UNDER ZONAL/WEAK NORTHWESTERLY FLOW IN THE UPPER LEVELS...A RESULT OF A BROAD HIGH PRESSURE IN PLACE ACROSS THE SCENTRAL/SWRN CONUS AND A TROUGH SHIFTING TOWARD THE EAST COAST. DURING THE OVERNIGHT HOURS...THE FLOW DOES AMPLIFY SOME AS ANOTHER TROUGH IS MAKING ITS WAY TOWARD THE WEST COAST...BUT NO NOTABLE DISTURBANCES LOOK TO MOVE THROUGH AND DECIDED TO KEEP THE FORECAST DRY. HOWEVER...MODELS DO SHOW THE SFC/LOWER LEVEL WINDS REMAINING S/SWRLY OVERNIGHT...WITH INCREASING VALUES OF ELEVATED INSTABILITY SHIFTING NORTH INTO THE REGION AS A STRONGER /30-35KT OR SO/ LLJ DEVELOPS...MAINLY ACROSS THE HIGH PLAINS REGION. THE EDGE OF THIS LLJ/INSTABILITY AXIS DOES LIE OVER THE WRN PORTIONS OF THE CWA...AND MAY HAVE TO KEEP AN EYE ON THIS AREA FOR THE POTENTIAL FOR PERHAPS SOME LIGHT PRECIP /BUT FORECAST SOUNDINGS ARE PRETTY DRY IN THE LOWER LEVELS/...OR A LITTLE MORE IN THE WAY OF CLOUD COVER. INTO MONDAY/MONDAY NIGHT...THE MAIN STORY LIES WITH THE ARRIVAL OF A MID/UPPER LEVEL WAVE...ASSOCIATED WITH A LOW PRESSURE SYSTEM LOCATED UP NEAR THE HUDSON BAY. KEPT THE DAYTIME HOURS ON MONDAY DRY...THOUGH A LITTLE MORE UNCERTAINTY ARISES TOWARD THE LATE AFTERNOON HOURS...WITH THE ACCOMPANYING SURFACE FRONTAL BOUNDARY LOOKS TO BE KNOCKING ON THE DOOR OF THE FAR NW CORNER OF THE CWA. DID RAISE POPS A BIT DURING THE EVENING/OVERNIGHT HOURS ACROSS THE N/NWRN PORTIONS OF THE CWA...BUT DIDNT MAKE MUCH CHANGE FURTHER SOUTH. AHEAD OF THE FRONT ON MONDAY...EXPECTING INCREASED SOUTHERLY WINDS...LIKELY A BIT GUSTY DURING THE AFTERNOON...AND WARMER TEMPERATURES WITH HIGHS FORECAST TO REACH INTO THE MID/UPPER 90S FOR MUCH/IF NOT ALL OF THE CWA. CONDITIONS DURING THE AFTERNOON HOURS SHOULD REMAIN BELOW CRITICAL FIRE LEVELS...RHS COULD DROP INTO THE LOWER/MID 20S ACROSS THE SOUTH...BUT SUSTAINED WIND SPEEDS ARE EXPECTED TO REMAIN <20 MPH...THOUGH GUSTS COULD AT TIMES COME CLOSE TO 25 MPH. WILL BE SOMETHING TO KEEP AN EYE ON IF MODELS HAPPEN TO TREND UP WINDS/TREND DOWN DPS. KEPT SOME LINGERING POPS IN DURING THE DAY ON TUESDAY...MAINLY ACROSS THE SRN HALF OF THE CWA...IN CLOSER PROXIMITY TO WHERE THE SFC BOUNDARY IS EXPECTED TO BE /SOMEWHERE NEAR OR SOUTH OF THE NEB AND KS STATE LINE/. CONFIDENCE NOT THE HIGHEST...AS THE PLACEMENT OF THE FRONT WILL BE DEPENDENT ON HOW THINGS PAN OUT MONDAY NIGHT. WITH MOST OF THE CWA LOOKING TO BE ON THE NORTH SIDE OF THAT BOUNDARY...MORE EASTERLY WINDS EXPECTED TO BE IN PLACE...AND FORECAST HIGHS ARE A TOUCH COOLER THAN MONDAY...MORE IN THE LOWER/MID 90S. BY 00Z WEDNESDAY...THE UPPER LEVEL PATTERN ACROSS THE CONUS HAS BECOME MORE AMPLIFIED...WITH MORE SOLIDLY NORTHWESTERLY FLOW IN PLACE ACROSS THE REGION AS THE RIDGE AXIS EXTENDS FROM THE DESERT SW THROUGH THE ROCKIES AND INTO CANADA. THE NOSE OF AN UPPER LEVEL JET STREAK ROUNDING THE TOP OF THE RIDGE AXIS IS EXPECTED TO SHIFT INTO THE REGION FROM THE NW...BRINGING THE POTENTIAL FOR MORE PRECIPITATION TUESDAY EVENING/OVERNIGHT. SIMILAR TO MONDAY/MONDAY NIGHT...WHILE THERE IS INSTABILITY IN PLACE ACROSS THE REGION...OVERALL DEEP LAYER SHEAR IS CERTAINLY NOT OUTSTANDING...GENERALLY TOPPING OUT IN THE 25-30 KTS RANGE...SO WHILE SOME THUNDERSTORMS COULD BE ON THE STRONGER SIDE...NOT EXPECTING SEVERE WEATHER AT THIS POINT. INTO WEDNESDAY...MODELS CONTINUE TO SHOW THE NOSE OF THIS UPPER LEVEL JET IN THE AREA...AND DECIDED TO KEEP SOME LINGERING POPS IN THE AREA...BUT CONFIDENCE IN CHANCES STICKING AROUND LONGER THAN PERHAPS A FEW HOURS IN THE MORNING NOT EXACTLY HIGH. THAT LOWER CONFIDENCE CONTINUES RIGHT ON THROUGH THE REMAINDER OF THE LONG TERM PERIOD. THE UPPER LEVEL PATTERN REMAINS NORTHWESTERLY ACROSS THE REGION WITH THE RIDGE STAYING IN PLACE OVER THE CENTRAL ROCKIES...AND KEPT THE FORECAST DRY AT THIS POINT...WITH MODELS SHOWING SOME DIFFERENCES WITH DISTURBANCES PASSING TO THE EAST OF THE CWA...AND WHETHER WE SEE ANY PRECIP AS RESULT. WITH THE RIDGE/WARMEST AIR REMAINING OFF TO THE WEST OF THE CWA...AND THE POTENTIAL FOR AN ADDITIONAL FRONTAL PASSAGE...NOTABLY HIGHER TEMPERATURES ARE NOT EXPECTED...WITH FORECAST HIGHS RANGING FROM ROUGHLY THE MID 90S WED/THUR TO THE MID 80S TO LOWER 90S FRI/SAT. && .PREV DISCUSSION... /ISSUED 1155 AM CDT SAT AUG 4 2012/ UPDATE...THE PRIMARY CHALLENGE FOR THE REST OF TODAY INVOLVES WHETHER THERE IS MUCH RISK AT ALL FOR MEASURABLE RAIN...AND JUST HOW COOL HIGH TEMPS MAY END UP BEING UNDER THE AREAS THAT HOLD ONTO CLOUDS THE LONGEST. 1630Z RADAR IMAGERY AND VISIBLE SATELLITE REVEAL A SCATTERED STREAM OF LIGHT SHOWERS/SPRINKLES LIKELY BASED AROUND 700MB STREAMING INTO SOUTHWEST PORTIONS OF THE CWA FROM THE WEST. THIS HIGH BASED ACTIVITY SEEMS FAIRLY WELL TIED TO A MODEST CORRIDOR OF CONVERGENCE/FRONTOGENESIS EVIDENT AT 700MB AND ALSO ON THE 315K ISENTROPIC SURFACE. THIS FORCING IS ALIGNED ALONG THE SOUTHERN PERIPHERY OF THE MAIN MID LEVEL SHORTWAVE AXIS TRAILING SOUTHWEST FROM THE PARENT STOUT VORT MAX NEAR THE MN/QUEBEC BORDER. EXPECTATION BASED ON SHORT TERM TRENDS FROM THE LATEST HRRR/RAP IS FOR MAINLY LIGHT HIGH BASED SHOWERS TO CONTINUE SPREADING FROM WEST TO EAST TROUGH AT LEAST 21Z OR SO ACROSS AREAS PRIMARILY SOUTH OF INTERSTATE 80...LIKELY AMOUNTING TO LITTLE MORE THAN A BRIEF SPRINKLE MOST SPOTS. HOWEVER...LEFT AN ISOLATED THUNDER AND EVEN A SMALL HAIL MENTION INTACT...JUST IN CASE A FEW STRONGER STORMS ARE ABLE TO FLARE UP AND TAP INTO ELEVATED MUCAPE POSSIBLY AS HIGH AS THE 500-1000 J/KG RANGE...BUT LIKELY LESS THAN THIS. THE MOST FAVORABLE AREA FOR ONE OF THESE STRONGER STORMS...SHOULD THEY EVEN DEVELOP...WOULD BE ACROSS A HANDFUL OF FAR SOUTHEASTERN COUNTIES. OTHERWISE...CURRENT EXPECTATION IS THAT ANY PRECIPITATION RISK FOR THE NEXT FEW DAYS WILL BE OVER WITH BY...OR SHORTLY AFTER 21Z THIS AFTERNOON. TEMP WISE TODAY...HAVE ESSENTIALLY LEFT PREVIOUS HIGH TEMPERATURES UNCHANGED. ANTICIPATE THAT AT LEAST CENTRAL/NORTHWEST PORTIONS OF THE CWA SHOULD SEE A RAPID CLEARING TREND AS THE AFTERNOON WEARS ON...LIKELY ALLOWING TEMPS TO EVENTUALLY JUMP UP TO FORECAST VALUES AROUND 83. HOWEVER...SOUTHEAST PORTIONS OF THE CWA THAT WILL LIKELY REMAIN UNDER THE CLOUDS THE LONGEST COULD STRUGGLE TO REACH THE FORECAST VALUES OF 82-84...AND AGREE WITH OVERNIGHT FORECASTER THAT SOME SPOTS MAY NOT ESCAPE THE UPPER 70S. WILL HAVE A BETTER HANDLE ON THIS BY AFTERNOON FORECAST ISSUANCE TIME. OTHERWISE...INTRUSION OF DRIER AIR BEHIND THE COLD FRONT HAS BEEN FAIRLY IMPRESSIVE WITH ORD DOWN TO 49 DEWPOINT NOW. AS A RESULT...LOWERED AFTERNOON DEWPOINTS 6-8 DEGREES ACROSS MUCH OF THE CWA...WITH COMFORTABLE 40S/LOW 50S DEWS LIKELY INTO MOST COUNTIES BY MID-LATE AFTERNOON. NORTH BREEZES WILL CONTINUE GUSTING AT LEAST 20-25 MPH THROUGH MID AFTERNOON...BEFORE STEADILY DECLINING BEFORE SUNSET. AVIATION...18Z KGRI TAF. VFR CEILING/VISIBILITY ARE FORECAST THROUGH THE PERIOD. ESSENTIALLY CLEAR SKIES WILL DOMINATE THE AREA THROUGH THE MAJORITY OF THE PERIOD...BUT FOR AT LEAST THE INITIAL 3-5 HOURS QUITE A BIT OF MID LEVEL CLOUD COVER WILL STREAM OVER...ALONG WITH JUST A SLIGHT CHANCE OF BRIEF PASSING SHOWERS...WHICH HAVE BEEN SUGGESTED WITH A VICINITY SHOWER MENTION. SURFACE BREEZES WILL REMAIN NORTHERLY THROUGH TONIGHT IN THE WAKE OF A SEASONABLY STRONG COLD FRONT. THE STRONGEST SPEEDS WITH GUST POTENTIAL TO AROUND 20KT WILL OCCUR DURING THE FIRST FEW HOURS OF THE PERIOD...BEFORE A STEADY SLACKENING OF SPEEDS COMMENCES. FROM SUNSET THROUGH MID-DAY SUNDAY...SPEEDS SHOULD AVERAGE UNDER 6KT AND BECOME A BIT VARIABLE IN DIRECTION WITH TIME. && .CLIMATE...TODAY/TONIGHT WILL LIKELY END UP BEING THE COOLEST DAY/NIGHT AT GRAND ISLAND AND HASTINGS IN 6.5 WEEKS. BASED ON FORECAST PROJECTIONS OVER THE NEXT FEW HOURS...THE CALENDAR DAY HIGH TEMPERATURE AT BOTH GRAND ISLAND AND HASTINGS WILL END UP SOMEWHERE BETWEEN 78-82 DEGREES...BUT IS GUARANTEED TO BE AT LEAST 78 BECAUSE THIS VALUE WAS REACHED SHORTLY AFTER MIDNIGHT BEFORE THE COLD FRONT INVADED. FOR GRAND ISLAND...A HIGH OF 79-82 DEGREES WOULD RESULT IN THE COOLEST DAILY HIGH SINCE JUNE 20TH...WHEN IT TOPPED OUT AT 79. FOR HASTINGS...A HIGH OF 78-79 DEGREES WOULD ALSO RESULT IN THE COOLEST DAY SINCE JUNE 20TH...WHEN IT REACHED 78. TURNING TO LOW TEMPERATURES TONIGHT...THE CURRENT FORECAST FOR BOTH GRAND ISLAND AND HASTINGS CALLS FOR 55. THIS IS ONLY 3 DEGREES ABOVE HASTINGS AUGUST 5TH RECORD LOW OF 52...AND 4 DEGREES ABOVE THE GRAND ISLAND RECORD LOW OF 51...BOTH SET IN 1994. ASSUMING IT DIPS TO AT LEAST 57 DEGREES OVERNIGHT...THIS WILL BE THE COOLEST LOW TEMP IN BOTH CITIES SINCE JUNE 21ST...WHEN GRAND ISLAND BOTTOMED OUT AT 52 AND HASTINGS 51. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM/AVIATION...PFANNKUCH LONG TERM...ADO
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
419 AM EDT SAT AUG 4 2012 .SYNOPSIS... A WEAK COLD FRONT SITUATED ACROSS THE NORTH COUNTRY WILL CONTINUE TO DROP SOUTH OF OUR REGION OVERNIGHT. THIS FRONT WILL LIFT NORTH BACK ACROSS OUR FORECAST AREA AS A WARM FRONT ON SATURDAY. SUNDAY NIGHT ANOTHER COLD FRONT WILL CROSS THE REGION. HIGH PRESSURE WILL THEN BUILD OVER THE REGION UNTIL ANOTHER COLD FRONT CROSSES THE AREA WEDNESDAY NIGHT INTO THURSDAY MORNING. ABOVE NORMAL TEMPERATURE TREND WILL CONTINUE THROUGH MOST OF THE 8 DAY FORECAST. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... AS OF 1257 AM EDT SATURDAY...OVERALL FORECAST IN GOOD SHAPE WITH MINOR ADJUSTMENTS TO HOURLY TEMPERATURES AND DEWPOINTS. ALSO ADDED PATCHY FOR FOR FAVORED AREAS AS RELATIVE HUMIDITIES OVER 90 PERCENT IN SOME LOCATIONS AND CONTINUED CLEAR SKIES WITH LITTLE TO NO WIND WILL KEEP RADIATIONAL COOLING GOING FOR A FEW MORE HOURS BEFORE THE SUN STARTS TO RISE. PREVIOUS DISCUSSION FOLLOWS...ANOTHER ROUND OF MINOR ADJUSTMENTS PERFORMED...MAINLY TO TEMPERATURE TRENDS NEAR LAKE CHAMPLAIN. MODIFICATION OF AIR TEMPERATURES NEAR LAKE CHAMPLAIN CONTINUE TO KEEP LOCATIONS ADJACENT TO THE LAKE WARMER THAN PREVIOUSLY FORECASTED...HAVE INCREASED OVERALL TEMPERATURES AROUND AND OVER THE LAKE TO ACCOUNT FOR THESE DIFFERENCES KEEPING MINIMUMS IN THE UPPER 60S NEAR 70 OVERNIGHT. THERE HAVE BEEN SOME INDICATIONS IN THE HRRR 3KM MODEL THAT INSTABILITY ASSOCIATED WITH LAKE ONTARIO WILL KICK OFF SOME EARLY MORNING SURPRISE SHOWERS AND AN ISOLATED THUNDERSTORM AROUND 10Z TO 12Z. CONTINUE TO HOLD BACK ON POPS DUE TO THERE BEING ONLY ONE INDICATOR THAT THIS WILL HAPPEN. OTHERWISE...OTHER THAN SOME FOG/MIST FORMING WHERE PRECIPITATION OCCURRED FRIDAY AFTERNOON...BENIGN WEATHER CONTINUES TO BE ANTICIPATED FOR THE NOCTURNAL HOURS. TEMPERATURES OVERNIGHT WILL GENERALLY BE IN THE LOW 60S FOR THE VALLEYS AND MID 50S IN THE HIGHER TERRAIN WITH A FEW OF THE COLDER HOLLOWS DROPPING TO NEAR 50 DEGREES. && .SHORT TERM /8 AM THIS MORNING THROUGH MONDAY/... AS OF 500 PM EDT FRIDAY...COLD FRONT WHICH DROPPED SOUTH ACROSS THE AREA ON FRIDAY WILL LIFT BACK NORTH OF THE AREA AS A COLD FRONT ON SATURDAY. SATURDAY WILL BE HOT...A GOOD 10 DEGREES ABOVE NORMAL WITH SOME MAX TEMPS IN THE UPPER 80S TO LOWER 90S. SHOWERS AND THUNDERSTORMS WILL POP OFF ALONG THE FRONT AS CAPE VALUES SURGE INTO THE MID 2000 RANGE...LIFTED INDICES DROP TO AROUND -8 AND SHOWALTERS AROUND -5. SHEAR WILL BE LACKING WITH WEAK FLOW IN GENERAL...THEREFORE HEAVY RAIN IS POSSIBLE WITH THUNDERSTORMS. CONVECTION SHOULD BE SCATTERED WITH HIGHEST POPS DEPICTED OVER THE HIGHER TERRAIN. STORMS DIE DOWN FOLLOWING SUNSET WITH LOSS OF DAYTIME HEATING...THOUGH NOT MUCH RELIEF AS FAR AS TEMPS ARE CONCERNED WITH REGION IN WARM SECTOR BEHIND THE WARM FRONT. TEMPS WILL ONLY DROP INTO THE MID TO UPPER 60S OVERNIGHT. FOG CAN AGAIN BE EXPECTED IN AREAS THAT HAD RAINFALL SATURDAY AFTERNOON. DURING THE DAYTIME HOURS ON SUNDAY...CHANCE FOR SHOWERS AND THUNDERSTORMS AHEAD OF APPROACHING COLD FRONT WILL INCREASE WEST TO EAST ACROSS THE AREA. SUNDAY WILL ALSO BE WARM AND MUGGY WITH MAX TEMPS IN THE MID TO UPPER 80S AGAIN. SOUTHERLY FLOW WILL PROVIDE SOME INSTABILITY AHEAD OF APPROACHING FRONT...CAPE VALUES WILL REACH AROUND 1800 LATE IN THE AFTERNOON...LIFTED INDICES AROUND -5. AS FRONT APPROACHES THE NORTH COUNTRY...STORMS WILL REACH THE SAINT LAWRENCE VALLEY REGION AROUND 21Z...THEN TRACK EASTWARD OVERNIGHT...ADIRONDACKS AROUND 00Z...AND MOVING INTO VERMONT AFTER MIDNIGHT. SHEAR IS MORE DECENT SUNDAY NIGHT...THOUGH BEST SHEAR WILL MOVE NORTH OF OUR REGION. PWATS OVER 1.75" THEREFORE COULD HAVE HEAVY RAIN WITH ANY THUNDERSTORMS THAT DEVELOP. FRONT WILL MOVE THROUGH AT A PRETTY STEADY PACE...SO NO LARGE SCALE FLOOD ISSUES EXPECTED THOUGH ISOLATED FLOODING IS POSSIBLE. TEMPERATURES SUNDAY NIGHT WILL REMAIN MILD...ONLY DROPPING TO THE UPPER 60S TO AROUND 70. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 419 AM EDT SATURDAY...ECMWF AND GFS MODELS SHOW A WEAK RIDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION MONDAY NIGHT AND WILL REMAIN OVER THE REGION THROUGH EARLY WEDNESDAY...WITH FAIR AND DRY WEATHER EXPECTED. ON WEDNESDAY...ECMWF AND GFS MODELS SHOW SOME WEAK SHORTWAVES WILL MOVE THROUGH THE REGION ON WEDNESDAY AND EARLY WEDNESDAY NIGHT. GFS AND ECMWF MODELS BOTH SHOW SOME CONVECTION DEVELOPING ALONG THE INTERNATIONAL BORDER BY WEDNESDAY AFTERNOON AND EARLY WEDNESDAY NIGHT...SO HAVE GONE WITH SLIGHT CHANCE POPS FOR SHOWERS AND THUNDERSTORMS NEAR THE CANADIAN BORDER. ON THURSDAY... MODEL GUIDANCE AGAIN SHOWING SOME MORE WEAK SHORTWAVES MOVING THROUGH THE REGION...SO HAVE GONE WITH SLIGHT CHANCE POPS FOR SHOWERS AND THUNDERSTORMS ON THURSDAY. EXPECTING DRY CONDITIONS THURSDAY NIGHT. ON FRIDAY...ECMWF AND GFS MODELS IN GOOD AGREEMENT IN SHOWING A LOW AT THE SURFACE AND ALOFT MOVING EAST FROM THE WESTERN GREAT LAKES... WITH BOTH MODELS SHOWING SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS THE REGION ON FRIDAY. ECMWF AND GFS MODELS IN GOOD AGREEMENT THROUGH THE FORECAST PERIOD. THUS...FORECASTER CONFIDENCE IS HIGH. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... THROUGH 06Z SUNDAY...MAINLY VFR THROUGH THE PERIOD...EXCEPT FOR SOME MORNING VALLEY FOG ACROSS THE SHELTERED VALLEYS OF EASTERN AND NORTHEAST VERMONT...AS WELL AS THE VALLEYS OF THE ADIRONDACKS ...WITH SOME AREAS OF IFR/LIFR IN FOG UNTIL 13Z SATURDAY...ESPECIALLY AT KSLK AND KMPV. LATEST MODEL GUIDANCE INDICATING STEEP LOW LEVEL LAPSE RATES DEVELOPING ACROSS THE REGION TODAY...WITH CONDITIONS DESTABILIZING BY THIS AFTERNOON. MODEL GUIDANCE INDICATING THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS TODAY WILL BE ACROSS THE WESTERN SLOPES OF THE GREEN MOUNTAIN IN VERMONT...AND OVER THE ADIRONDACKS IN NORTHERN NEW YORK. HAVE INCLUDED A MENTION OF THUNDERSTORMS IN THE VICINITY AFTER 18Z SATURDAY IN THE TAFS AT KMPV...KRUT AND KSLK. EXPECTING ANY STORMS THAT DEVELOP TODAY WILL BEGIN TO DISSIPATE AROUND 00Z SUNDAY...WITH THE LOSS OF DAYTIME SURFACE HEATING. OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...MAINLY VFR THROUGH MIDDAY SUNDAY. MVFR/IFR IN BR/FG ALSO POSSIBLE AT MPV/SLK 06Z-12Z SUNDAY. APPROACH OF COLD FRONT WILL LEAD TO WIDESPREAD CONVECTION LATE SUNDAY THROUGH SUNDAY NIGHT. A FEW OF THE STRONGER STORMS SUNDAY AFTERNOON/EVENING HAVE THE POTENTIAL TO PRODUCE PERIODS OF IFR CONDITIONS. CHANCE OF GUSTY WINDS WITH THUNDERSTORMS AS WELL. COOLER AND DRIER AIR ARRIVES ON MONDAY WITH MAINLY VFR CONDITIONS ANTICIPATED MONDAY INTO WEDNESDAY AS A RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION. && .MARINE... LIGHT AND VARIABLE WINDS TONIGHT INTO EARLY SATURDAY MORNING WILL SHIFT OUT OF THE SOUTH AT 5 TO 15 KNOTS DURING THE DAY SATURDAY. HOWEVER...WINDS WILL INCREASE SATURDAY NIGHT AND ESPECIALLY ON SUNDAY WITH STRONG SOUTH WINDS FROM 20 TO 30 KNOTS ANTICIPATED. WAVES WILL BE 1 TO 2 FEET THROUGH SATURDAY...BUILDING TO 2 TO 4 FEET BY SUNDAY. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...NEILES NEAR TERM...KGM/BOYD SHORT TERM...NEILES LONG TERM...WGH AVIATION...WGH/RJS MARINE...KGM/MUCILLI
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
235 AM EDT SAT AUG 4 2012 .SYNOPSIS... A WEAK COLD FRONT SITUATED ACROSS THE NORTH COUNTRY WILL CONTINUE TO DROP SOUTH OF OUR REGION OVERNIGHT. THIS FRONT WILL LIFT NORTH BACK ACROSS OUR FORECAST AREA AS A WARM FRONT ON SATURDAY. SUNDAY NIGHT ANOTHER COLD FRONT WILL CROSS THE REGION. HIGH PRESSURE WILL THEN BUILD OVER THE REGION UNTIL ANOTHER COLD FRONT CROSSES THE AREA WEDNESDAY NIGHT INTO THURSDAY MORNING. ABOVE NORMAL TEMPERATURE TREND WILL CONTINUE THROUGH MOST OF THE 8 DAY FORECAST. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... AS OF 1257 AM EDT SATURDAY...OVERALL FORECAST IN GOOD SHAPE WITH MINOR ADJUSTMENTS TO HOURLY TEMPERATURES AND DEWPOINTS. ALSO ADDED PATCHY FOR FOR FAVORED AREAS AS RELATIVE HUMIDITIES OVER 90 PERCENT IN SOME LOCATIONS AND CONTINUED CLEAR SKIES WITH LITTLE TO NO WIND WILL KEEP RADIATIONAL COOLING GOING FOR A FEW MORE HOURS BEFORE THE SUN STARTS TO RISE. PREVIOUS DISCUSSION FOLLOWS...ANOTHER ROUND OF MINOR ADJUSTMENTS PERFORMED...MAINLY TO TEMPERATURE TRENDS NEAR LAKE CHAMPLAIN. MODIFICATION OF AIR TEMPERATURES NEAR LAKE CHAMPLAIN CONTINUE TO KEEP LOCATIONS ADJACENT TO THE LAKE WARMER THAN PREVIOUSLY FORECASTED...HAVE INCREASED OVERALL TEMPERATURES AROUND AND OVER THE LAKE TO ACCOUNT FOR THESE DIFFERENCES KEEPING MINIMUMS IN THE UPPER 60S NEAR 70 OVERNIGHT. THERE HAVE BEEN SOME INDICATIONS IN THE HRRR 3KM MODEL THAT INSTABILITY ASSOCIATED WITH LAKE ONTARIO WILL KICK OFF SOME EARLY MORNING SURPRISE SHOWERS AND AN ISOLATED THUNDERSTORM AROUND 10Z TO 12Z. CONTINUE TO HOLD BACK ON POPS DUE TO THERE BEING ONLY ONE INDICATOR THAT THIS WILL HAPPEN. OTHERWISE...OTHER THAN SOME FOG/MIST FORMING WHERE PRECIPITATION OCCURRED FRIDAY AFTERNOON...BENIGN WEATHER CONTINUES TO BE ANTICIPATED FOR THE NOCTURNAL HOURS. TEMPERATURES OVERNIGHT WILL GENERALLY BE IN THE LOW 60S FOR THE VALLEYS AND MID 50S IN THE HIGHER TERRAIN WITH A FEW OF THE COLDER HOLLOWS DROPPING TO NEAR 50 DEGREES. && .SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY NIGHT/... AS OF 500 PM EDT FRIDAY...COLD FRONT WHICH DROPPED SOUTH ACROSS THE AREA ON FRIDAY WILL LIFT BACK NORTH OF THE AREA AS A COLD FRONT ON SATURDAY. SATURDAY WILL BE HOT...A GOOD 10 DEGREES ABOVE NORMAL WITH SOME MAX TEMPS IN THE UPPER 80S TO LOWER 90S. SHOWERS AND THUNDERSTORMS WILL POP OFF ALONG THE FRONT AS CAPE VALUES SURGE INTO THE MID 2000 RANGE...LIFTED INDICES DROP TO AROUND -8 AND SHOWALTERS AROUND -5. SHEAR WILL BE LACKING WITH WEAK FLOW IN GENERAL...THEREFORE HEAVY RAIN IS POSSIBLE WITH THUNDERSTORMS. CONVECTION SHOULD BE SCATTERED WITH HIGHEST POPS DEPICTED OVER THE HIGHER TERRAIN. STORMS DIE DOWN FOLLOWING SUNSET WITH LOSS OF DAYTIME HEATING...THOUGH NOT MUCH RELIEF AS FAR AS TEMPS ARE CONCERNED WITH REGION IN WARM SECTOR BEHIND THE WARM FRONT. TEMPS WILL ONLY DROP INTO THE MID TO UPPER 60S OVERNIGHT. FOG CAN AGAIN BE EXPECTED IN AREAS THAT HAD RAINFALL SATURDAY AFTERNOON. DURING THE DAYTIME HOURS ON SUNDAY...CHANCE FOR SHOWERS AND THUNDERSTORMS AHEAD OF APPROACHING COLD FRONT WILL INCREASE WEST TO EAST ACROSS THE AREA. SUNDAY WILL ALSO BE WARM AND MUGGY WITH MAX TEMPS IN THE MID TO UPPER 80S AGAIN. SOUTHERLY FLOW WILL PROVIDE SOME INSTABILITY AHEAD OF APPROACHING FRONT...CAPE VALUES WILL REACH AROUND 1800 LATE IN THE AFTERNOON...LIFTED INDICES AROUND -5. AS FRONT APPROACHES THE NORTH COUNTRY...STORMS WILL REACH THE SAINT LAWRENCE VALLEY REGION AROUND 21Z...THEN TRACK EASTWARD OVERNIGHT...ADIRONDACKS AROUND 00Z...AND MOVING INTO VERMONT AFTER MIDNIGHT. SHEAR IS MORE DECENT SUNDAY NIGHT...THOUGH BEST SHEAR WILL MOVE NORTH OF OUR REGION. PWATS OVER 1.75" THEREFORE COULD HAVE HEAVY RAIN WITH ANY THUNDERSTORMS THAT DEVELOP. FRONT WILL MOVE THROUGH AT A PRETTY STEADY PACE...SO NO LARGE SCALE FLOOD ISSUES EXPECTED THOUGH ISOLATED FLOODING IS POSSIBLE. TEMPERATURES SUNDAY NIGHT WILL REMAIN MILD...ONLY DROPPING TO THE UPPER 60S TO AROUND 70. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 344 PM EDT FRIDAY...ECMWF AND GFS INDICATE A CHANCE OF SHOWERS EARLY MONDAY...MAINLY ACROSS VERMONT...AS COLD FRONT AND UPPER TROUGH PUSH EAST OF THE REGION. MID LEVEL DRY SLOT THEN BUILDS IN BY MIDDAY...SO EXPECT CLEARING SKIES ACROSS THE REGION BY MONDAY AFTERNOON. IT WILL TURN LESS HUMID AND BE A LITTLE COOLER...WITH HIGHS GENERALLY IN THE UPPER 70S AND LOWER 80S. ECMWF AND GFS REMAIN IN GOOD AGREEMENT IN SHOWING A WEAK RIDGE OF HIGH PRESSURE OVER THE NORTH COUNTRY FROM MONDAY NIGHT THROUGH EARLY WEDNESDAY...WITH FAIR AND DRY WEATHER EXPECTED. A SERIES OF WEAK UPPER SHORTWAVES WILL THEN MOVE ACROSS THE REGION WEDNESDAY AFTERNOON THROUGH THURSDAY...BRINGING A LOW CHANCE FOR SHOWERS AND STORMS TO THE REGION...ESPECIALLY TO THE HIGHER TERRAIN AND ACROSS THE NORTHERN ZONES. LATEST ECMWF INDICATING A MORE PRONOUNCED TROUGH MOVING INTO THE NORTHEAST FRIDAY...SO HAVE GONE WITH CHANCE POPS ACROSS THE ENTIRE AREA FRIDAY INTO FRIDAY NIGHT. TEMPERATURES WILL BE A BIT ABOVE NORMAL TUESDAY THROUGH THURSDAY...THEN LOWER TO SEASONAL LEVELS FRIDAY DUE MORE CLOUD COVER. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... THROUGH 06Z SUNDAY...MAINLY VFR THROUGH THE PERIOD...EXCEPT FOR SOME MORNING VALLEY FOG ACROSS THE SHELTERED VALLEYS OF EASTERN AND NORTHEAST VERMONT...AS WELL AS THE VALLEYS OF THE ADIRONDACKS ...WITH SOME AREAS OF IFR/LIFR IN FOG UNTIL 13Z SATURDAY...ESPECIALLY AT KSLK AND KMPV. LATEST MODEL GUIDANCE INDICATING STEEP LOW LEVEL LAPSE RATES DEVELOPING ACROSS THE REGION TODAY...WITH CONDITIONS DESTABILIZING BY THIS AFTERNOON. MODEL GUIDANCE INDICATING THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS TODAY WILL BE ACROSS THE WESTERN SLOPES OF THE GREEN MOUNTAIN IN VERMONT...AND OVER THE ADIRONDACKS IN NORTHERN NEW YORK. HAVE INCLUDED A MENTION OF THUNDERSTORMS IN THE VICINITY AFTER 18Z SATURDAY IN THE TAFS AT KMPV...KRUT AND KSLK. EXPECTING ANY STORMS THAT DEVELOP TODAY WILL BEGIN TO DISSIPATE AROUND 00Z SUNDAY...WITH THE LOSS OF DAYTIME SURFACE HEATING. OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...MAINLY VFR THROUGH MIDDAY SUNDAY. MVFR/IFR IN BR/FG ALSO POSSIBLE AT MPV/SLK 06Z-12Z SUNDAY. APPROACH OF COLD FRONT WILL LEAD TO WIDESPREAD CONVECTION LATE SUNDAY THROUGH SUNDAY NIGHT. A FEW OF THE STRONGER STORMS SUNDAY AFTERNOON/EVENING HAVE THE POTENTIAL TO PRODUCE PERIODS OF IFR CONDITIONS. CHANCE OF GUSTY WINDS WITH THUNDERSTORMS AS WELL. COOLER AND DRIER AIR ARRIVES ON MONDAY WITH MAINLY VFR CONDITIONS ANTICIPATED MONDAY INTO WEDNESDAY AS A RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION. && .MARINE... LIGHT AND VARIABLE WINDS TONIGHT INTO EARLY SATURDAY MORNING WILL SHIFT OUT OF THE SOUTH AT 5 TO 15 KNOTS DURING THE DAY SATURDAY. HOWEVER...WINDS WILL INCREASE SATURDAY NIGHT AND ESPECIALLY ON SUNDAY WITH STRONG SOUTH WINDS FROM 20 TO 30 KNOTS ANTICIPATED. WAVES WILL BE 1 TO 2 FEET THROUGH SATURDAY...BUILDING TO 2 TO 4 FEET BY SUNDAY. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...NEILES NEAR TERM...KGM/BOYD SHORT TERM...NEILES LONG TERM...RJS AVIATION...WGH/RJS MARINE...KGM/MUCCILLI
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
138 AM EDT SAT AUG 4 2012 .SYNOPSIS... A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE AREA THIS EVENING...ACCOMPANIED BY A SMALL CHANCE FOR THUNDERSTORMS THROUGH EARLY EVENING. MAINLY DRY HOT WEATHER WILL RETURN ON SATURDAY. A STRONGER COLD FRONT WILL BRING A BETTER CHANCE OF THUNDERSTORMS ON SUNDAY... FOLLOWED BY COOLER DRY WEATHER ON MONDAY. && .NEAR TERM /THROUGH TODAY/... 930 AM UPDATE...NO CHGS TO CRNT FCST WITH A QUIET OVRNGT PD XPCTD. PREV BLO... 730 PM UPDATE...WELL IT TOOK SOME OF THE HIGHEST TRRN IN THE CWA TO HELP TRIGGER AN ISOLD TSRA OVER CNTRL DELAWARE CNTY. STORM BCM ANCHORED NEAR MT PISGAH AND BACK-BUILT/TRAINED FOR NEARLY 2 HRS. RR AMTS UP 3-3.5 INCHES. THIS STORM HAS SINCE DSPTD AND SEE LTL POTNL FOR ADDNL DVLPMNT ACRS THE FCST AREA...SO WILL REMOVE POPS AND GO WITH MAINLY CLEAR TO SKC TNGT. FOG POTNL ALSO LIMITED AND DON`T XPCT IT TO BE DENSE ENUF TO INCLUDE IN THE WX GRIDS. PREV BLO... 4 PM UPDATE...MAINLY SKC ACRS THE BGM FCST AREA WITH XCPTN OF SOME MID/HI CLD ACRS THE FINGER LAKES AND FAR SE ZONES. WSR-88D SHOWS A WEAK E-W BNDRY BNDRY FROM SRN SCHUYLER/TOMPKINS ACRS NRN BROOME INTO SRN CHENANGO CNTY. HOWEVER...TD`S ARE LOWEST ACRS THE SRN TIER AND ANY LOW LVL CONVERGENCE WILL BE WEAK DUE TO THE LGT WINDS VCNTY OF THE BNDRY. LACK OF UPR DYNAMICS AND LOW LVL CIN CONTINUE TO IMPEDE DVLPMNT. GIVEN THESE TRENDS...WE LOWERED POPS TO SLGT CHC FOR LATE THIS AFTN/EVNG AND LOWERED SKY CVR. PREV BLO... 2 PM UPDATE...NOT MUCH GOING ON ATTM ON RADAR AND WITH A BIT OF A MID LEVEL CAP BETWEEN H8 AND H9 MB....A LOT OF US ARE NOT EVEN SEEING A CU FIELD FORM. THE EXCEPTION IS ACROSS WESTERN NY NEAR KROC SOUTHEAST THROUGH THE FINGER LAKES. THIS AREA IS RIGHT AHEAD OF A COLD FRONT THAT IS WASHING OUT OVER CNY. THIS CU FIELD MATCHES UP QUITE WELL WITH THE NAM 12 AND LATEST HRRR WHICH CONTINUES TO SHOW ISOLATED CONVECTION DEVELOPING THROUGH 21Z ACROSS THE FINGER LAKES...THROUGH THE SOUTHERN TIER INTO NORTHERN PA. CONTINUED TO PLAY SLIGHT CHANCE POPS OVERALL THROUGH EVENING...BUT HIGHLIGHT THE AREAS MENTIONED ABOVE FOR A CHANCE OF A FEW ISOLATED STORMS. SEVERE STORMS ARE NOT EXPECTED GIVEN WEAK MID LEVEL SHEAR (0-6 KM LESS THAN 20 KTS)...BUT BRIEF GUSTY WINDS (DOWN BURSTS) A POSSIBILITY GIVEN SBCAPES IN THE 1000-2000 J/KG RANGE AND AN INVERTED V SOUNDING. WHAT CONVECTION WE SEE THIS EVENING WILL DIMINISH QUICKLY THIS EVENING. WE WILL AGAIN BE IN A RICH ENVIRONMENT SATURDAY WITH MLCAPES IN THE 1000-2000 J/KG RANGE BUT WE WILL AGAIN BE LACKING A TRIGGER. THE FRONT WHICH WILL CAUSE SOME ACTION THIS EVENING...WILL BE WASHED OUT. ANY UPPER LEVEL SUPPORT LOOKS TO STAY NORTH OF OUR CWA AS THE UPPER LEVEL FLOW BECOMES MORE SOUTHWESTERLY. CONTINUED WITH THE MENTIONED OF ISOLATED CONVECTION AS WE MAY HAVE SOME LEFTOVER BOUNDARIES FROM TODAY BUT MOST WILL REMAIN DRY. THE BIGGEST STORY SATURDAY WILL AGAIN BE HOT TEMPS WITH HIGHS WELL INTO THE 90S. && .SHORT TERM /TONIGHT THROUGH MONDAY/... DEEP S-SWLY FLOW WILL BECOME ESTABLISHED OVER THE REGION ON SATURDAY NIGHT AS SIGNIFICANT UPPER TROF PLOWS THROUGH THE GTLKS REGION. OVERALL...WILL FOLLOW THE NAM AND ECMWF SOLUTIONS DURING THIS TIME AS GFS LOOKS A LITTLE AGGRESSIVE IN DEVELOPING CONVECTION WELL OUT AHEAD OF THE MAIN TROF WITHOUT MUCH FORCING. THAT SAID...WILL CARRY SOME SMALL CHANCES FOR TSRA ACROSS THE SOUTHERN PART OF FCST AREA AS BEGINNINGS OF HEIGHT FALLS AND POTENTIAL FOR AN EMBEDDED MINOR WAVE COMING OUT OF PENNSYLVANIA COULD SPAWN SOME LATE NIGHT ACTIVITY AND THE 12KM NAM IS SUGGESTING SOME ACTIVITY IN CNTRL PA WORKING NORTH FROM 03Z-09Z. ON SUNDAY...DESTABILIZATION OF THE LOWER TROPOSPHERE WILL CONTINUE...MAINLY DUE TO THE INFLUX OF LOW LEVEL MOISTURE AS OPPOSED TO A LOT OF PRISTINE SOLAR HEATING HOURS. CNY/NEPA REGION SHOULD START THE DAY OFF PRETTY JUNKED UP WITH LOW LVL CLOUDINESS AS A RESULT OF WARM AND MOIST ADVECTIONS SAT NIGHT. BREAKS IN CLOUDS ARE EXPECTED LATER ON WITH OVERALL MEAN LYR CAPE VALUES RANGING IN THE 1000-1500 J/KG RANGE. WITH SUCH A DYNAMIC UPPER SYSTEM APPROACHING...THIS IS MORE THAN ENOUGH ENERGY. 0-3 KM AND 0-1 KM BULK SHEAR VALUES ARE FCST IN THE 25-30 KT RANGE IN A VERTICALLY LAMINAR FASHION. THE MODEL TRENDS CONTINUE TO SLOW THE PASSAGE OF THE ACTUAL SFC FRONT DOWN TO LATE SUNDAY NIGHT...HOWEVER REGIME OF 500 MB HEIGHT FALLS AND BEST JET DIVERGENCE ARE EXPECTED TO COINCIDE OVER CNY/NEPA DURING THE LATE AFTERNOON AND EVENING HOURS. AT THIS TIME...THE PARAMETERS SUGGEST A LINEAR CONVECTIVE MODE OF MULTICELLS AND LINES WITH WIND DAMAGE THE HIGHEST CONCERN. HEADING INTO MONDAY...THE FRONT AND UPPER TROF AXIS CLEARS THE REGION SHORTLY BEFORE 12Z WITH COOLER AND DRIER HIGH PRESSURE TO FOLLOW. HAVE REDUCED POPS ON MONDAY TO JUST THE EARLIEST FEW HOURS AROUND 12Z...AND THAT STILL MAY BE A BIT TOO MUCH WITH MOST MODEL TRENDS SUGGESTING THAT DEEP MOISTURE AND FORCING WILL BE EAST OF THE REGION. CLOUDS MAY LIMIT TEMPS A BIT ON SUNDAY...BUT STILL EXPECT TO BE WELL INTO THE 80S AFTER A PRETTY MILD AND MUGGY START TO THE DAY. IT SHOULD FEEL RATHER OPPRESSIVE WITH FCST DWPTS REACHING THE LOWER 70S ON SUNDAY...BUT WITHOUT TEMPERATURES SURGING INTO THE 90S THE DANGER FROM EXCESSIVE HEAT IS NOT ANTICIPATED. COOLER...DRIER AND MORE SEASONABLE CONDITIONS ARE FORECAST MONDAY AND GENERALLY FOLLOWED BLENDED MOS GUIDANCE TRENDS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... HIGH PRESSURE LINGERS OVER THE REGION THROUGH TUESDAY...WHICH WILL THEN BE FOLLOWED BY ANOTHER WEAK COLD FRONT AND BROAD UPPER TROF DRIFTING INTO THE REGION FROM WEDNESDAY THROUGH FRIDAY. THESE FEATURES WILL LIKELY ACT AS THE FOCUS FOR SOME SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY DRIVEN BY DIURNAL INFLUENCES. THE LATEST GFS AND LAST NIGHT/S ECMWF DEFINITELY DIFFER ON SOLUTIONS FOR THIS PERIOD WITH THE ECMWF ILLUSTRATING A STRONGER TROF PASSAGE THROUGH THE EAST THURSDAY NIGHT INTO FRIDAY. HPC THINKS THIS HAS LITTLE SUPPORT WITHIN THE GENERAL ENSEMBLE FORECASTS AND WILL LEAN WITH THEIR GENTLER APPROACH. ENSEMBLE THERMAL FORECASTS AT 850 MB SHOW NO ANOMALOUS DEVIATIONS... THEREFORE WILL FOLLOW A BLEND OF HPC AND MOS GUIDANCE ON TEMPERATURES WHICH SHOULD TURN OUT TO BE FAIRLY NORMAL. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... IN GENERAL VFR CONDITIONS ARE EXPECTED THROUGH THIS TAF PERIOD. THERE MAY BE MVFR VSBY RESTRICTIONS DUE TO HZ/BR AT KELM/KAVP EARLY THIS MORNING BETWEEN 09Z-12Z. JUST SCATTERED CI THROUGH MID MORNING THEN SCT CU AROUND 5K FT TODAY. ISOLATED CONVECTION IS POSSIBLE THIS AFTERNOON IN THE HIGHER TERRAIN BUT NOT INCLUDED IN TAFS DUE TO VERY LIMITED AREAL COVERAGE. OVERNIGHT AS NEXT SYSTEM APPROACHES REGION SCT MID CLOUDS ARE LIKELY. WINDS WILL BE LIGHT AND VARIABLE INTO MID MORNING THEN SOUTHERLY AROUND 10 KNOTS BECOMING SOUTHEAST TONIGHT AROUND 5 KNOTS. OUTLOOK... SUN MORNING...VFR WITH POSSIBLE MVFR VSBYS RESTRICTIONS EARLY SUN AM DUE TO HAZE. SUNDAY AFTERNOON THROUGH SUNDAY EVENING...A COLD FRONT PASSING THROUGH THE REGION WILL PRODUCE WIDESPREAD SHOWERS AND THUNDERSTORMS WITH MVFR/IFR RESTRICTIONS IN STORMS. MON - WED...AT THIS EARLY VANTAGE PT...PRIMARILY VFR ANTICIPATED. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...JAB NEAR TERM...HEDEN SHORT TERM...JAB LONG TERM...JAB AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1257 AM EDT SAT AUG 4 2012 .SYNOPSIS... A WEAK COLD FRONT SITUATED ACROSS THE NORTH COUNTRY WILL CONTINUE TO DROP SOUTH OF OUR REGION OVERNIGHT. THIS FRONT WILL LIFT NORTH BACK ACROSS OUR FORECAST AREA AS A WARM FRONT ON SATURDAY. SUNDAY NIGHT ANOTHER COLD FRONT WILL CROSS THE REGION. HIGH PRESSURE WILL THEN BUILD OVER THE REGION UNTIL ANOTHER COLD FRONT CROSSES THE AREA WEDNESDAY NIGHT INTO THURSDAY MORNING. ABOVE NORMAL TEMPERATURE TREND WILL CONTINUE THROUGH MOST OF THE 8 DAY FORECAST. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... AS OF 1257 AM EDT SATURDAY...OVERALL FORECAST IN GOOD SHAPE WITH MINOR ADJUSTMENTS TO HOURLY TEMPERATURES AND DEWPOINTS. ALSO ADDED PATCHY FOR FOR FAVORED AREAS AS RELATIVE HUMIDITIES OVER 90 PERCENT IN SOME LOCATIONS AND CONTINUED CLEAR SKIES WITH LITTLE TO NO WIND WILL KEEP RADIATIONAL COOLING GOING FOR A FEW MORE HOURS BEFORE THE SUN STARTS TO RISE. PREVIOUS DISCUSSION FOLLOWS...ANOTHER ROUND OF MINOR ADJUSTMENTS PERFORMED...MAINLY TO TEMPERATURE TRENDS NEAR LAKE CHAMPLAIN. MODIFICATION OF AIR TEMPERATURES NEAR LAKE CHAMPLAIN CONTINUE TO KEEP LOCATIONS ADJACENT TO THE LAKE WARMER THAN PREVIOUSLY FORECASTED...HAVE INCREASED OVERALL TEMPERATURES AROUND AND OVER THE LAKE TO ACCOUNT FOR THESE DIFFERENCES KEEPING MINIMUMS IN THE UPPER 60S NEAR 70 OVERNIGHT. THERE HAVE BEEN SOME INDICATIONS IN THE HRRR 3KM MODEL THAT INSTABILITY ASSOCIATED WITH LAKE ONTARIO WILL KICK OFF SOME EARLY MORNING SURPRISE SHOWERS AND AN ISOLATED THUNDERSTORM AROUND 10Z TO 12Z. CONTINUE TO HOLD BACK ON POPS DUE TO THERE BEING ONLY ONE INDICATOR THAT THIS WILL HAPPEN. OTHERWISE...OTHER THAN SOME FOG/MIST FORMING WHERE PRECIPITATION OCCURRED FRIDAY AFTERNOON...BENIGN WEATHER CONTINUES TO BE ANTICIPATED FOR THE NOCTURNAL HOURS. TEMPERATURES OVERNIGHT WILL GENERALLY BE IN THE LOW 60S FOR THE VALLEYS AND MID 50S IN THE HIGHER TERRAIN WITH A FEW OF THE COLDER HOLLOWS DROPPING TO NEAR 50 DEGREES. && .SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY NIGHT/... AS OF 500 PM EDT FRIDAY...COLD FRONT WHICH DROPPED SOUTH ACROSS THE AREA ON FRIDAY WILL LIFT BACK NORTH OF THE AREA AS A COLD FRONT ON SATURDAY. SATURDAY WILL BE HOT...A GOOD 10 DEGREES ABOVE NORMAL WITH SOME MAX TEMPS IN THE UPPER 80S TO LOWER 90S. SHOWERS AND THUNDERSTORMS WILL POP OFF ALONG THE FRONT AS CAPE VALUES SURGE INTO THE MID 2000 RANGE...LIFTED INDICES DROP TO AROUND -8 AND SHOWALTERS AROUND -5. SHEAR WILL BE LACKING WITH WEAK FLOW IN GENERAL...THEREFORE HEAVY RAIN IS POSSIBLE WITH THUNDERSTORMS. CONVECTION SHOULD BE SCATTERED WITH HIGHEST POPS DEPICTED OVER THE HIGHER TERRAIN. STORMS DIE DOWN FOLLOWING SUNSET WITH LOSS OF DAYTIME HEATING...THOUGH NOT MUCH RELIEF AS FAR AS TEMPS ARE CONCERNED WITH REGION IN WARM SECTOR BEHIND THE WARM FRONT. TEMPS WILL ONLY DROP INTO THE MID TO UPPER 60S OVERNIGHT. FOG CAN AGAIN BE EXPECTED IN AREAS THAT HAD RAINFALL SATURDAY AFTERNOON. DURING THE DAYTIME HOURS ON SUNDAY...CHANCE FOR SHOWERS AND THUNDERSTORMS AHEAD OF APPROACHING COLD FRONT WILL INCREASE WEST TO EAST ACROSS THE AREA. SUNDAY WILL ALSO BE WARM AND MUGGY WITH MAX TEMPS IN THE MID TO UPPER 80S AGAIN. SOUTHERLY FLOW WILL PROVIDE SOME INSTABILITY AHEAD OF APPROACHING FRONT...CAPE VALUES WILL REACH AROUND 1800 LATE IN THE AFTERNOON...LIFTED INDICES AROUND -5. AS FRONT APPROACHES THE NORTH COUNTRY...STORMS WILL REACH THE SAINT LAWRENCE VALLEY REGION AROUND 21Z...THEN TRACK EASTWARD OVERNIGHT...ADIRONDACKS AROUND 00Z...AND MOVING INTO VERMONT AFTER MIDNIGHT. SHEAR IS MORE DECENT SUNDAY NIGHT...THOUGH BEST SHEAR WILL MOVE NORTH OF OUR REGION. PWATS OVER 1.75" THEREFORE COULD HAVE HEAVY RAIN WITH ANY THUNDERSTORMS THAT DEVELOP. FRONT WILL MOVE THROUGH AT A PRETTY STEADY PACE...SO NO LARGE SCALE FLOOD ISSUES EXPECTED THOUGH ISOLATED FLOODING IS POSSIBLE. TEMPERATURES SUNDAY NIGHT WILL REMAIN MILD...ONLY DROPPING TO THE UPPER 60S TO AROUND 70. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 344 PM EDT FRIDAY...ECMWF AND GFS INDICATE A CHANCE OF SHOWERS EARLY MONDAY...MAINLY ACROSS VERMONT...AS COLD FRONT AND UPPER TROUGH PUSH EAST OF THE REGION. MID LEVEL DRY SLOT THEN BUILDS IN BY MIDDAY...SO EXPECT CLEARING SKIES ACROSS THE REGION BY MONDAY AFTERNOON. IT WILL TURN LESS HUMID AND BE A LITTLE COOLER...WITH HIGHS GENERALLY IN THE UPPER 70S AND LOWER 80S. ECMWF AND GFS REMAIN IN GOOD AGREEMENT IN SHOWING A WEAK RIDGE OF HIGH PRESSURE OVER THE NORTH COUNTRY FROM MONDAY NIGHT THROUGH EARLY WEDNESDAY...WITH FAIR AND DRY WEATHER EXPECTED. A SERIES OF WEAK UPPER SHORTWAVES WILL THEN MOVE ACROSS THE REGION WEDNESDAY AFTERNOON THROUGH THURSDAY...BRINGING A LOW CHANCE FOR SHOWERS AND STORMS TO THE REGION...ESPECIALLY TO THE HIGHER TERRAIN AND ACROSS THE NORTHERN ZONES. LATEST ECMWF INDICATING A MORE PRONOUNCED TROUGH MOVING INTO THE NORTHEAST FRIDAY...SO HAVE GONE WITH CHANCE POPS ACROSS THE ENTIRE AREA FRIDAY INTO FRIDAY NIGHT. TEMPERATURES WILL BE A BIT ABOVE NORMAL TUESDAY THROUGH THURSDAY...THEN LOWER TO SEASONAL LEVELS FRIDAY DUE MORE CLOUD COVER. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... THROUGH 00Z SUNDAY...VFR CONDITIONS EXPECTED AT MOST LOCATIONS THROUGH THE PERIOD. THE ONLY EXCEPTION TO THIS WILL BE SOME VLIFR CONDITIONS AT KSLK AND KMPV BETWEEN 07Z AND 13Z DUE TO LOW CLOUDS AND FOG. SCATTERED CUMULUS CLOUDS SHOULD FORM SATURDAY AFTERNOON AND ISOLATED STORMS WILL DEVELOP AFTER 20Z. WINDS WILL GENERALLY BE LIGHT AND VARIABLE TONIGHT...THEN TREND TOWARD A MORE SOUTHERLY DIRECTION LATE SATURDAY MORNING INTO AFTERNOON. OUTLOOK 00Z SUNDAY THROUGH WEDNESDAY...MAINLY VFR THROUGH MIDDAY SUNDAY. THERE WILL BE WIDELY SCATTERED SHOWERS AND THUNDERSTORMS SATURDAY AFTERNOON/EVENING WITH BRIEF MVFR POSSIBLE. MVFR/IFR IN BR/FG ALSO POSSIBLE AT MPV/SLK 06Z-12Z SUNDAY. APPROACH OF COLD FRONT WILL LEAD TO WIDESPREAD CONVECTION LATE SUNDAY THROUGH SUNDAY NIGHT. A FEW OF THE STRONGER STORMS SUNDAY AFTERNOON/EVENING HAVE THE POTENTIAL TO PRODUCE PERIODS OF IFR CONDITIONS. CHANCE OF GUSTY WINDS WITH THUNDERSTORMS AS WELL. COOLER AND DRIER AIR ARRIVES ON MONDAY WITH MAINLY VFR CONDITIONS ANTICIPATED MONDAY INTO WEDNESDAY AS A RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION. && .MARINE... LIGHT AND VARIABLE WINDS TONIGHT INTO EARLY SATURDAY MORNING WILL SHIFT OUT OF THE SOUTH AT 5 TO 15 KNOTS DURING THE DAY SATURDAY. HOWEVER...WINDS WILL INCREASE SATURDAY NIGHT AND ESPECIALLY ON SUNDAY WITH STRONG SOUTH WINDS FROM 20 TO 30 KNOTS ANTICIPATED. WAVES WILL BE 1 TO 2 FEET THROUGH SATURDAY...BUILDING TO 2 TO 4 FEET BY SUNDAY. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...NEILES NEAR TERM...KGM/BOYD SHORT TERM...NEILES LONG TERM...RJS AVIATION...EVENSON/RJS MARINE...KGM/MUCCILLI
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
115 PM EDT SAT AUG 4 2012 .SYNOPSIS... BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AS OF 1030 AM SATURDAY...DEEP TROPICAL SOUTHEASTERLY FLOW DEVELOPING ACROSS THE REGION TODAY WHILE MID LEVEL LOW OVER THE REGION BOTH LIFTS OUT TO THE NORTH AND WEAKENS. THIS LEAVES THE COASTAL CAROLINAS WITH LITTLE IN THE WAY OF FORCING FOR PRECIP OTHER THAN FRICTIONAL CONVERGENCE ALONG THE COAST. 12Z WRF SHOWING JUST A FEW TROPICAL SHOWERS MATERIALIZING OVER NC COASTAL ZONES. HRRR RUNS GO BACK AND FORTH BETWEEN SHOWING MINIMAL COVERAGE AND NO COVERAGE AT ALL. AS OF 700 AM SATURDAY...LOOK FOR MORE OF A TROPICAL INFLUENCE ACROSS THE REGION THIS FORECAST PERIOD. THE WESTERN ATLANTIC HIGH TO FLEX ITS MUSCLES AND RIDGE ACROSS THE FA BOTH SFC AND ALOFT THRU THE PERIOD. AN INVERTED SFC TROF TO PASS OVER THE BAHAMAS TODAY...AND PROGGED TO TRACK NW TO AND ACROSS THE NORTHERN FLORIDA PENINSULA TONIGHT INTO SUNDAY. HOURLY NAMBUFR SOUNDINGS INDICATE A GENERAL INCREASE OF PWS TO AROUND 2 INCHES TONIGHT INTO SUNDAY. WINDS THRU THE ATM COLUMN TO BECOME BASICALLY ONSHORE INDICATIVE OF A TROPICAL INFLUENCE ACROSS THE FA. THE SEA BREEZE OR RESULTANT WIND TYPE CONVECTION WILL COMMENCE BY MID-LATE THIS MORNING...AND TRACK INLAND THROUGHOUT THE DAY AS ADVERTIZED BY THE LATEST HRRR MODEL RUNS. MODEL SOUNDING DATA INDICATE PWS OF 2 INCHES...AND A SLOW MOVEMENT OF THE CONVECTION...BASICALLY BETWEEN 5 AND 10 KT. AS A RESULT...THE MAIN THREAT FROM TODAYS CONVECTION WILL BE FROM HEAVY RAIN. FOR TONIGHT...ONSHORE MOVEMENT OF PCPN DURING THE PRE-DAWN HRS OF SUNDAY TO OCCUR AS A MUCH DEEPER ONSHORE FLOW EVOLVES THRU THE ATM COLUMN. WILL ILLUSTRATE LOW CHANCE POPS FOR THE COASTAL AREAS. COMPROMISED BETWEEN THE VARIOUS MODEL MOS GUIDANCE FOR MAX/MIN TEMPS THRUOUT THE NEAR TERM. && .SHORT TERM /SUNDAY MORNING THROUGH MONDAY NIGHT/...AS OF 3:00 AM SATURDAY...MID LEVEL RIDGING WILL CONTINUE TO BE THE MAIN WEATHER MAKER SUNDAY. MONDAY WILL FEATURE A SLIGHT CHANGE AS THE RIDGE RETREATS TO THE EAST AND A FRONT MOVES AT LEAST CLOSER TO THE AREA FROM THE NORTHWEST. THIS ALLOWS POPS TO INCREASE FROM ISOLATED/SLIGHT CHANCE SUNDAY TO CHANCE MONDAY PRIMARILY MONDAY AFTERNOON. THERMAL PROFILES ARE ALMOST IDENTICAL FOR BOTH AFTERNOONS AND MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON DAYTIME HIGHS ALMOST SPOT ON CLIMATOLOGY WITH OVERNIGHT LOWS JUST ABOVE. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 3:00 AM SATURDAY...MID LEVEL PATTERN WILL FEATURE SUBTLE EAST COAST TROUGHING WITH RIDGING CENTERED ACROSS THE ROCKIES AND ACROSS THE CENTRAL ATLANTIC. AT THE SURFACE A WEAK FRONT/PIEDMONT TROUGH WILL BE THE FEATURES OF NOTE. THE FRONT APPEARS TO STALL AS WOULD BE EXPECTED THIS TIME OF YEAR TO THE WEST/NORTHWEST. TOUGH TO ASCERTAIN WHICH DAY WILL FEATURE THE BEST CHANCE FOR RAIN AND BASICALLY MAINTAINED THE DIURNAL CYCLE AND CHANCE VALUES. IF ANYTHING...THURSDAY AND FRIDAY APPEAR SLIGHTLY MORE CONDUCIVE PER THE FAVORED ECMWF HIGH RESOLUTION FROM HPC. NO CHANGES TO TEMPERATURE FORECAST WHICH SHOULD HOVER AROUND CLIMATOLOGY. && .AVIATION /18Z SATURDAY THROUGH WEDNESDAY/... AS OF 18Z...TROPICAL ENVIRONMENT WITH SOUTHEAST FLOW THROUGH 500 MB. THIS REGIME WILL GIVE US SCATTERED CONVECTION ALONG THE RESULTANT THIS AFTERNOON. GIVEN THE UPPER FLOW...SEA BREEZE CONVECTION SHOULD GENERALLY REMAIN INLAND FROM THE COASTAL TERMINALS. MOST OF THE STUFF WILL BE FAIRLY LOW TOPPED...HOWEVER SCATTERED THUNDER IS EXPECTED. SOUTHEAST WINDS WILL CONTINUE INTO THE EVENING HOURS. SUNDAY...SYNOPTICALLY SIMILAR TO TODAY...WITH AFTERNOON THUNDER PERSISTING. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR/IFR VSBYS FROM BR/FG WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM SATURDAY...SEAS JUST 2.5 FT ALL THE WAY OUT AT BUOY 41013 WITH DOMINANT PERIOD 8-9 SECONDS INDICATIVE OF SWELL ENERGY. JUST A SUBLET CHANGE TO SEAS FORECAST FROM A STRAIGHT 3 FT TO THAT OF 2 TO 3 FT AS A THOUSAND MILE SOUTHEAST FETCH CONTINUES INTO THE CAROLINAS. AS OF 700 AM SATURDAY...THE WESTERN ATLANTIC HIGH...SFC AND ALOFT... WILL GOVERN THE ILM COASTAL WATERS. THE SFC RIDGE AXIS EXTENDING SW FROM THE CENTER OF THIS HIGH...WILL CROSS THE WATERS THRU THE PERIOD. THE ACTUAL POSITIONING OF THIS AXIS ACROSS THE LOCAL WATERS WILL DETERMINE WIND DIRECTIONS. LOOK FOR SE TO S WIND DIRECTIONS SOUTH OF THE AXIS AND S TO SSW NORTH OF THE AXIS. THE SFC PG WILL BE CONDUCIVE FOR 10-15 KT WIND SPEEDS. WILL HAVE TO MONITOR THE STRENGTH AND MOVEMENT OF AN INVERTED TROF OF LOW PRESSURE FROM THE BAHAMAS TO AND ACROSS THE NORTHERN FLORIDA PENINSULA ON SUNDAY. WIND SPEEDS MAY INCREASE TO A SOLID 15 KT SOUTH OF CAPE FEAR. SIGNIFICANT SEAS WILL BE RULED BY A 2 TO 3 FT ESE GROUND SWELL EXHIBITING 8-9 SECOND PERIODS. FOR TONIGHT...SIG SEAS TO BUILD TO 3 TO 4 FT DUE TO THE CLOSER PROXIMITY OF THE INVERTED SFC TROF. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 3:00 AM SATURDAY...BERMUDA HIGH PRESSURE AND SEA BREEZE WILL DOMINATE THE COASTAL WATERS THROUGH THE PERIOD WITH SLIGHTLY MORE INFLUENCE FROM A FRONT MOVING CLOSER LATE MONDAY. WIND SPEEDS MAY ADD A KNOT OR TWO AT THIS TIME. SEAS ARE RATHER UNEVENTFUL AS WELL WITH 2-3 FEET FOR THE MOST PART. A FEW FOUR FOOTERS CANNOT BE RULED OUT EARLY ACROSS THE OUTER WATERS. LONG TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 3:00 AM SATURDAY...SUMMERTIME PATTERN CONTINUES ACROSS THE COASTAL WATERS FOR THE MARINE COMMUNITY. SOUTHWEST WINDS OF 10-15 KNOTS WILL PREVAIL WITH A SLIGHT BACKING DURING THE DAY COURTESY OF THE SEA BREEZE. NO REAL SIGNAL FROM TROPICAL ACTIVITY VIA THE WAVEWATCH GUIDANCE AS SEAS REMAIN IN A 2-4 FOOT RANGE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...MBB SHORT TERM...SHK LONG TERM...SHK AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1030 AM EDT SAT AUG 4 2012 .SYNOPSIS... BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AS OF 1030 AM SATURDAY...DEEP TROPICAL SOUTHEASTERLY FLOW DEVELOPING ACROSS THE REGION TODAY WHILE MID LEVEL LOW OVER THE REGION BOTH LIFTS OUT TO THE NORTH AND WEAKENS. THIS LEAVES THE COASTAL CAROLINAS WITH LITTLE IN THE WAY OF FORCING FOR PRECIP OTHER THAN FRICTIONAL CONVERGENCE ALONG THE COAST. 12Z WRF SHOWING JUST A FEW TROPICAL SHOWERS MATERIALIZING OVER NC COASTAL ZONES. HRRR RUNS GO BACK AND FORTH BETWEEN SHOWING MINIMAL COVERAGE AND NO COVERAGE AT ALL. AS OF 700 AM SATURDAY...LOOK FOR MORE OF A TROPICAL INFLUENCE ACROSS THE REGION THIS FORECAST PERIOD. THE WESTERN ATLANTIC HIGH TO FLEX ITS MUSCLES AND RIDGE ACROSS THE FA BOTH SFC AND ALOFT THRU THE PERIOD. AN INVERTED SFC TROF TO PASS OVER THE BAHAMAS TODAY...AND PROGGED TO TRACK NW TO AND ACROSS THE NORTHERN FLORIDA PENINSULA TONIGHT INTO SUNDAY. HOURLY NAMBUFR SOUNDINGS INDICATE A GENERAL INCREASE OF PWS TO AROUND 2 INCHES TONIGHT INTO SUNDAY. WINDS THRU THE ATM COLUMN TO BECOME BASICALLY ONSHORE INDICATIVE OF A TROPICAL INFLUENCE ACROSS THE FA. THE SEA BREEZE OR RESULTANT WIND TYPE CONVECTION WILL COMMENCE BY MID-LATE THIS MORNING...AND TRACK INLAND THROUGHOUT THE DAY AS ADVERTIZED BY THE LATEST HRRR MODEL RUNS. MODEL SOUNDING DATA INDICATE PWS OF 2 INCHES...AND A SLOW MOVEMENT OF THE CONVECTION...BASICALLY BETWEEN 5 AND 10 KT. AS A RESULT...THE MAIN THREAT FROM TODAYS CONVECTION WILL BE FROM HEAVY RAIN. FOR TONIGHT...ONSHORE MOVEMENT OF PCPN DURING THE PRE-DAWN HRS OF SUNDAY TO OCCUR AS A MUCH DEEPER ONSHORE FLOW EVOLVES THRU THE ATM COLUMN. WILL ILLUSTRATE LOW CHANCE POPS FOR THE COASTAL AREAS. COMPROMISED BETWEEN THE VARIOUS MODEL MOS GUIDANCE FOR MAX/MIN TEMPS THRUOUT THE NEAR TERM. && .SHORT TERM /SUNDAY MORNING THROUGH MONDAY NIGHT/...AS OF 3:00 AM SATURDAY...MID LEVEL RIDGING WILL CONTINUE TO BE THE MAIN WEATHER MAKER SUNDAY. MONDAY WILL FEATURE A SLIGHT CHANGE AS THE RIDGE RETREATS TO THE EAST AND A FRONT MOVES AT LEAST CLOSER TO THE AREA FROM THE NORTHWEST. THIS ALLOWS POPS TO INCREASE FROM ISOLATED/SLIGHT CHANCE SUNDAY TO CHANCE MONDAY PRIMARILY MONDAY AFTERNOON. THERMAL PROFILES ARE ALMOST IDENTICAL FOR BOTH AFTERNOONS AND MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON DAYTIME HIGHS ALMOST SPOT ON CLIMATOLOGY WITH OVERNIGHT LOWS JUST ABOVE. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 3:00 AM SATURDAY...MID LEVEL PATTERN WILL FEATURE SUBTLE EAST COAST TROUGHING WITH RIDGING CENTERED ACROSS THE ROCKIES AND ACROSS THE CENTRAL ATLANTIC. AT THE SURFACE A WEAK FRONT/PIEDMONT TROUGH WILL BE THE FEATURES OF NOTE. THE FRONT APPEARS TO STALL AS WOULD BE EXPECTED THIS TIME OF YEAR TO THE WEST/NORTHWEST. TOUGH TO ASCERTAIN WHICH DAY WILL FEATURE THE BEST CHANCE FOR RAIN AND BASICALLY MAINTAINED THE DIURNAL CYCLE AND CHANCE VALUES. IF ANYTHING...THURSDAY AND FRIDAY APPEAR SLIGHTLY MORE CONDUCIVE PER THE FAVORED ECMWF HIGH RESOLUTION FROM HPC. NO CHANGES TO TEMPERATURE FORECAST WHICH SHOULD HOVER AROUND CLIMATOLOGY. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... AS OF 12Z...ANY LIGHT FOG AROUND WILL QUICKLY DISSIPATE BY 1230Z. FAIRLY TYPICAL SUMMER DAY WITH TCU`S ALREADY LURKING OFFSHORE. LOOK FOR ISOLATED/SCATTERED CONVECTION ALONG THE SEA BREEZE BOUNDARY...BEGINNING NEAR THE COAST AROUND 16Z. LFC`S ARE THE LOWEST IN PENDER COUNTY...SO THAT MAY BE THE INITIATION AREA FOR CONVECTION. SOUTHEAST FLOW THROUGH 500 MB WILL GIVE US A TROPICAL LIKE ENVIRONMENT WITH LOW BASED CU AND GREAT VISIBILITY. ANY ONGOING CONVECTION LATE THIS AFTERNOON WILL LIKELY DISSIPATE BY 22-23Z FOR DIURNAL REASONS. LIGHT WINDS OVERNIGHT WITH POSSIBLE LIGHT FOG A COUPLE OF HOURS BEFORE SUNRISE. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR/IFR VSBYS FROM BR/FG WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM SATURDAY...SEAS JUST 2.5 FT ALL THE WAY OUT AT BUOY 41013 WITH DOMINANT PERIOD 8-9 SECONDS INDICATIVE OF SWELL ENERGY. JUST A SUBLET CHANGE TO SEAS FORECAST FROM A STRAIGHT 3 FT TO THAT OF 2 TO 3 FT AS A THOUSAND MILE SOUTHEAST FETCH CONTINUES INTO THE CAROLINAS. AS OF 700 AM SATURDAY...THE WESTERN ATLANTIC HIGH...SFC AND ALOFT... WILL GOVERN THE ILM COASTAL WATERS. THE SFC RIDGE AXIS EXTENDING SW FROM THE CENTER OF THIS HIGH...WILL CROSS THE WATERS THRU THE PERIOD. THE ACTUAL POSITIONING OF THIS AXIS ACROSS THE LOCAL WATERS WILL DETERMINE WIND DIRECTIONS. LOOK FOR SE TO S WIND DIRECTIONS SOUTH OF THE AXIS AND S TO SSW NORTH OF THE AXIS. THE SFC PG WILL BE CONDUCIVE FOR 10-15 KT WIND SPEEDS. WILL HAVE TO MONITOR THE STRENGTH AND MOVEMENT OF AN INVERTED TROF OF LOW PRESSURE FROM THE BAHAMAS TO AND ACROSS THE NORTHERN FLORIDA PENINSULA ON SUNDAY. WIND SPEEDS MAY INCREASE TO A SOLID 15 KT SOUTH OF CAPE FEAR. SIGNIFICANT SEAS WILL BE RULED BY A 2 TO 3 FT ESE GROUND SWELL EXHIBITING 8-9 SECOND PERIODS. FOR TONIGHT...SIG SEAS TO BUILD TO 3 TO 4 FT DUE TO THE CLOSER PROXIMITY OF THE INVERTED SFC TROF. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 3:00 AM SATURDAY...BERMUDA HIGH PRESSURE AND SEA BREEZE WILL DOMINATE THE COASTAL WATERS THROUGH THE PERIOD WITH SLIGHTLY MORE INFLUENCE FROM A FRONT MOVING CLOSER LATE MONDAY. WIND SPEEDS MAY ADD A KNOT OR TWO AT THIS TIME. SEAS ARE RATHER UNEVENTFUL AS WELL WITH 2-3 FEET FOR THE MOST PART. A FEW FOUR FOOTERS CANNOT BE RULED OUT EARLY ACROSS THE OUTER WATERS. LONG TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 3:00 AM SATURDAY...SUMMERTIME PATTERN CONTINUES ACROSS THE COASTAL WATERS FOR THE MARINE COMMUNITY. SOUTHWEST WINDS OF 10-15 KNOTS WILL PREVAIL WITH A SLIGHT BACKING DURING THE DAY COURTESY OF THE SEA BREEZE. NO REAL SIGNAL FROM TROPICAL ACTIVITY VIA THE WAVEWATCH GUIDANCE AS SEAS REMAIN IN A 2-4 FOOT RANGE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...MBB SHORT TERM...SHK LONG TERM...SHK AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
716 AM EDT SAT AUG 4 2012 .SYNOPSIS... BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AS OF 700 AM SATURDAY...LOOK FOR MORE OF A TROPICAL INFLUENCE ACROSS THE REGION THIS FORECAST PERIOD. THE WESTERN ATLANTIC HIGH TO FLEX ITS MUSCLES AND RIDGE ACROSS THE FA BOTH SFC AND ALOFT THRU THE PERIOD. AN INVERTED SFC TROF TO PASS OVER THE BAHAMAS TODAY...AND PROGGED TO TRACK NW TO AND ACROSS THE NORTHERN FLORIDA PENINSULA TONIGHT INTO SUNDAY. HOURLY NAMBUFR SOUNDINGS INDICATE A GENERAL INCREASE OF PWS TO AROUND 2 INCHES TONIGHT INTO SUNDAY. WINDS THRU THE ATM COLUMN TO BECOME BASICALLY ONSHORE INDICATIVE OF A TROPICAL INFLUENCE ACROSS THE FA. THE SEA BREEZE OR RESULTANT WIND TYPE CONVECTION WILL COMMENCE BY MID-LATE THIS MORNING...AND TRACK INLAND THROUGHOUT THE DAY AS ADVERTIZED BY THE LATEST HRRR MODEL RUNS. MODEL SOUNDING DATA INDICATE PWS OF 2 INCHES...AND A SLOW MOVEMENT OF THE CONVECTION...BASICALLY BETWEEN 5 AND 10 KT. AS A RESULT...THE MAIN THREAT FROM TODAYS CONVECTION WILL BE FROM HEAVY RAIN. FOR TONIGHT...ONSHORE MOVEMENT OF PCPN DURING THE PRE-DAWN HRS OF SUNDAY TO OCCUR AS A MUCH DEEPER ONSHORE FLOW EVOLVES THRU THE ATM COLUMN. WILL ILLUSTRATE LOW CHANCE POPS FOR THE COASTAL AREAS. COMPROMISED BETWEEN THE VARIOUS MODEL MOS GUIDANCE FOR MAX/MIN TEMPS THRUOUT THE NEAR TERM. && .SHORT TERM /SUNDAY MORNING THROUGH MONDAY NIGHT/...AS OF 3:00 AM SATURDAY...MID LEVEL RIDGING WILL CONTINUE TO BE THE MAIN WEATHER MAKER SUNDAY. MONDAY WILL FEATURE A SLIGHT CHANGE AS THE RIDGE RETREATS TO THE EAST AND A FRONT MOVES AT LEAST CLOSER TO THE AREA FROM THE NORTHWEST. THIS ALLOWS POPS TO INCREASE FROM ISOLATED/SLIGHT CHANCE SUNDAY TO CHANCE MONDAY PRIMARILY MONDAY AFTERNOON. THERMAL PROFILES ARE ALMOST IDENTICAL FOR BOTH AFTERNOONS AND MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON DAYTIME HIGHS ALMOST SPOT ON CLIMATOLOGY WITH OVERNIGHT LOWS JUST ABOVE. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 3:00 AM SATURDAY...MID LEVEL PATTERN WILL FEATURE SUBTLE EAST COAST TROUGHING WITH RIDGING CENTERED ACROSS THE ROCKIES AND ACROSS THE CENTRAL ATLANTIC. AT THE SURFACE A WEAK FRONT/PIEDMONT TROUGH WILL BE THE FEATURES OF NOTE. THE FRONT APPEARS TO STALL AS WOULD BE EXPECTED THIS TIME OF YEAR TO THE WEST/NORTHWEST. TOUGH TO ASCERTAIN WHICH DAY WILL FEATURE THE BEST CHANCE FOR RAIN AND BASICALLY MAINTAINED THE DIURNAL CYCLE AND CHANCE VALUES. IF ANYTHING...THURSDAY AND FRIDAY APPEAR SLIGHTLY MORE CONDUCIVE PER THE FAVORED ECMWF HIGH RESOLUTION FROM HPC. NO CHANGES TO TEMPERATURE FORECAST WHICH SHOULD HOVER AROUND CLIMATOLOGY. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... AS OF 12Z...ANY LIGHT FOG AROUND WILL QUICKLY DISSIPATE BY 1230Z. FAIRLY TYPICAL SUMMER DAY WITH TCU`S ALREADY LURKING OFFSHORE. LOOK FOR ISOLATED/SCATTERED CONVECTION ALONG THE SEA BREEZE BOUNDARY...BEGINNING NEAR THE COAST AROUND 16Z. LFC`S ARE THE LOWEST IN PENDER COUNTY...SO THAT MAY BE THE INITIATION AREA FOR CONVECTION. SOUTHEAST FLOW THROUGH 500 MB WILL GIVE US A TROPICAL LIKE ENVIRONMENT WITH LOW BASED CU AND GREAT VISIBILITY. ANY ONGOING CONVECTION LATE THIS AFTERNOON WILL LIKELY DISSIPATE BY 22-23Z FOR DIURNAL REASONS. LIGHT WINDS OVERNIGHT WITH POSSIBLE LIGHT FOG A COUPLE OF HOURS BEFORE SUNRISE. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR/IFR VSBYS FROM BR/FG WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 700 AM SATURDAY...THE WESTERN ATLANTIC HIGH...SFC AND ALOFT... WILL GOVERN THE ILM COASTAL WATERS. THE SFC RIDGE AXIS EXTENDING SW FROM THE CENTER OF THIS HIGH...WILL CROSS THE WATERS THRU THE PERIOD. THE ACTUAL POSITIONING OF THIS AXIS ACROSS THE LOCAL WATERS WILL DETERMINE WIND DIRECTIONS. LOOK FOR SE TO S WIND DIRECTIONS SOUTH OF THE AXIS AND S TO SSW NORTH OF THE AXIS. THE SFC PG WILL BE CONDUCIVE FOR 10-15 KT WIND SPEEDS. WILL HAVE TO MONITOR THE STRENGTH AND MOVEMENT OF AN INVERTED TROF OF LOW PRESSURE FROM THE BAHAMAS TO AND ACROSS THE NORTHERN FLORIDA PENINSULA ON SUNDAY. WIND SPEEDS MAY INCREASE TO A SOLID 15 KT SOUTH OF CAPE FEAR. SIGNIFICANT SEAS WILL BE RULED BY A 2 TO 3 FT ESE GROUND SWELL EXHIBITING 8-9 SECOND PERIODS. FOR TONIGHT...SIG SEAS TO BUILD TO 3 TO 4 FT DUE TO THE CLOSER PROXIMITY OF THE INVERTED SFC TROF. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 3:00 AM SATURDAY...BERMUDA HIGH PRESSURE AND SEA BREEZE WILL DOMINATE THE COASTAL WATERS THROUGH THE PERIOD WITH SLIGHTLY MORE INFLUENCE FROM A FRONT MOVING CLOSER LATE MONDAY. WIND SPEEDS MAY ADD A KNOT OR TWO AT THIS TIME. SEAS ARE RATHER UNEVENTFUL AS WELL WITH 2-3 FEET FOR THE MOST PART. A FEW FOUR FOOTERS CANNOT BE RULED OUT EARLY ACROSS THE OUTER WATERS. LONG TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 3:00 AM SATURDAY...SUMMERTIME PATTERN CONTINUES ACROSS THE COASTAL WATERS FOR THE MARINE COMMUNITY. SOUTHWEST WINDS OF 10-15 KNOTS WILL PREVAIL WITH A SLIGHT BACKING DURING THE DAY COURTESY OF THE SEA BREEZE. NO REAL SIGNAL FROM TROPICAL ACTIVITY VIA THE WAVEWATCH GUIDANCE AS SEAS REMAIN IN A 2-4 FOOT RANGE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...DCH SHORT TERM...SHK LONG TERM...SHK AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
701 AM EDT SAT AUG 4 2012 .SYNOPSIS... BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AS OF 700 AM SATURDAY...LOOK FOR MORE OF A TROPICAL INFLUENCE ACROSS THE REGION THIS FORECAST PERIOD. THE WESTERN ATLANTIC HIGH TO FLEX ITS MUSCLES AND RIDGE ACROSS THE FA BOTH SFC AND ALOFT THRU THE PERIOD. AN INVERTED SFC TROF TO PASS OVER THE BAHAMAS TODAY...AND PROGGED TO TRACK NW TO AND ACROSS THE NORTHERN FLORIDA PENINSULA TONIGHT INTO SUNDAY. HOURLY NAMBUFR SOUNDINGS INDICATE A GENERAL INCREASE OF PWS TO AROUND 2 INCHES TONIGHT INTO SUNDAY. WINDS THRU THE ATM COLUMN TO BECOME BASICALLY ONSHORE INDICATIVE OF A TROPICAL INFLUENCE ACROSS THE FA. THE SEA BREEZE OR RESULTANT WIND TYPE CONVECTION WILL COMMENCE BY MID-LATE THIS MORNING...AND TRACK INLAND THROUGHOUT THE DAY AS ADVERTIZED BY THE LATEST HRRR MODEL RUNS. MODEL SOUNDING DATA INDICATE PWS OF 2 INCHES...AND A SLOW MOVEMENT OF THE CONVECTION...BASICALLY BETWEEN 5 AND 10 KT. AS A RESULT...THE MAIN THREAT FROM TODAYS CONVECTION WILL BE FROM HEAVY RAIN. FOR TONIGHT...ONSHORE MOVEMENT OF PCPN DURING THE PRE-DAWN HRS OF SUNDAY TO OCCUR AS A MUCH DEEPER ONSHORE FLOW EVOLVES THRU THE ATM COLUMN. WILL ILLUSTRATE LOW CHANCE POPS FOR THE COASTAL AREAS. COMPROMISED BETWEEN THE VARIOUS MODEL MOS GUIDANCE FOR MAX/MIN TEMPS THRUOUT THE NEAR TERM. && .SHORT TERM /SUNDAY MORNING THROUGH MONDAY NIGHT/...AS OF 3:00 AM SATURDAY...MID LEVEL RIDGING WILL CONTINUE TO BE THE MAIN WEATHER MAKER SUNDAY. MONDAY WILL FEATURE A SLIGHT CHANGE AS THE RIDGE RETREATS TO THE EAST AND A FRONT MOVES AT LEAST CLOSER TO THE AREA FROM THE NORTHWEST. THIS ALLOWS POPS TO INCREASE FROM ISOLATED/SLIGHT CHANCE SUNDAY TO CHANCE MONDAY PRIMARILY MONDAY AFTERNOON. THERMAL PROFILES ARE ALMOST IDENTICAL FOR BOTH AFTERNOONS AND MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON DAYTIME HIGHS ALMOST SPOT ON CLIMATOLOGY WITH OVERNIGHT LOWS JUST ABOVE. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 3:00 AM SATURDAY...MID LEVEL PATTERN WILL FEATURE SUBTLE EAST COAST TROUGHING WITH RIDGING CENTERED ACROSS THE ROCKIES AND ACROSS THE CENTRAL ATLANTIC. AT THE SURFACE A WEAK FRONT/PIEDMONT TROUGH WILL BE THE FEATURES OF NOTE. THE FRONT APPEARS TO STALL AS WOULD BE EXPECTED THIS TIME OF YEAR TO THE WEST/NORTHWEST. TOUGH TO ASCERTAIN WHICH DAY WILL FEATURE THE BEST CHANCE FOR RAIN AND BASICALLY MAINTAINED THE DIURNAL CYCLE AND CHANCE VALUES. IF ANYTHING...THURSDAY AND FRIDAY APPEAR SLIGHTLY MORE CONDUCIVE PER THE FAVORED ECMWF HIGH RESOLUTION FROM HPC. NO CHANGES TO TEMPERATURE FORECAST WHICH SHOULD HOVER AROUND CLIMATOLOGY. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... AS OF 06Z...EXPECT MVFR AND/OR IFR VSBYS FROM BR/FG DURING THE 08Z-13Z TIME FRAME. FLO AND/OR LBT TERMINALS WILL HAVE THE GREATER POTENTIAL TO OBSERVE PREVAILING BR/FG...WHEREAS THE COASTAL TERMINALS WILL INDICATE TEMPO MVFR VSBYS. COULD OBSERVE A SUB-1000 FT CLOUD DECK ALONG THE COASTAL TERMS WITHIN A 4 HR WINDOW SURROUNDING SUNRISE. BY MID-MORNING...ANY RESIDUAL BR SHOULD DISSIPATE...LEAVING VFR CONDITIONS FOR THE REMAINDER OF THE DAY. THE PROB OF THUNDERSTORMS REMAINS ON THE LOW SIDE...BUT ENOUGH CONFIDENCE TO MENTION VCTS AT ALL TERMINALS FROM MIDDAY THROUGH EARLY THIS EVENING. PREVAILING SE-S WINDS AT 5 TO 10 KT EXPECTED...UP TO 15 KT AT THE COASTAL TERMINALS. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR/IFR VSBYS FROM BR/FG WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 700 AM SATURDAY...THE WESTERN ATLANTIC HIGH...SFC AND ALOFT... WILL GOVERN THE ILM COASTAL WATERS. THE SFC RIDGE AXIS EXTENDING SW FROM THE CENTER OF THIS HIGH...WILL CROSS THE WATERS THRU THE PERIOD. THE ACTUAL POSITIONING OF THIS AXIS ACROSS THE LOCAL WATERS WILL DETERMINE WIND DIRECTIONS. LOOK FOR SE TO S WIND DIRECTIONS SOUTH OF THE AXIS AND S TO SSW NORTH OF THE AXIS. THE SFC PG WILL BE CONDUCIVE FOR 10-15 KT WIND SPEEDS. WILL HAVE TO MONITOR THE STRENGTH AND MOVEMENT OF AN INVERTED TROF OF LOW PRESSURE FROM THE BAHAMAS TO AND ACROSS THE NORTHERN FLORIDA PENINSULA ON SUNDAY. WIND SPEEDS MAY INCREASE TO A SOLID 15 KT SOUTH OF CAPE FEAR. SIGNIFICANT SEAS WILL BE RULED BY A 2 TO 3 FT ESE GROUND SWELL EXHIBITING 8-9 SECOND PERIODS. FOR TONIGHT...SIG SEAS TO BUILD TO 3 TO 4 FT DUE TO THE CLOSER PROXIMITY OF THE INVERTED SFC TROF. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 3:00 AM SATURDAY...BERMUDA HIGH PRESSURE AND SEA BREEZE WILL DOMINATE THE COASTAL WATERS THROUGH THE PERIOD WITH SLIGHTLY MORE INFLUENCE FROM A FRONT MOVING CLOSER LATE MONDAY. WIND SPEEDS MAY ADD A KNOT OR TWO AT THIS TIME. SEAS ARE RATHER UNEVENTFUL AS WELL WITH 2-3 FEET FOR THE MOST PART. A FEW FOUR FOOTERS CANNOT BE RULED OUT EARLY ACROSS THE OUTER WATERS. LONG TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 3:00 AM SATURDAY...SUMMERTIME PATTERN CONTINUES ACROSS THE COASTAL WATERS FOR THE MARINE COMMUNITY. SOUTHWEST WINDS OF 10-15 KNOTS WILL PREVAIL WITH A SLIGHT BACKING DURING THE DAY COURTESY OF THE SEA BREEZE. NO REAL SIGNAL FROM TROPICAL ACTIVITY VIA THE WAVEWATCH GUIDANCE AS SEAS REMAIN IN A 2-4 FOOT RANGE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...DCH SHORT TERM...SHK LONG TERM...SHK AVIATION...DCH/MRR
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
656 AM EDT SAT AUG 4 2012 .SYNOPSIS... HIGH PRESSURE WILL BUILD IN FROM THE EAST THROUGH THE WEEKEND. A COLD FRONT WILL APPROACH FROM THE WEST MONDAY AND TUESDAY BUT WILL STALL AND WEAKEN WEST OF THE AREA WEDNESDAY THROUGH LATE NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 650 AM SATURDAY...PER EARLIER RUNS OF THE RAP MODEL AND THE 06Z NAM...SCATTERED SHOWERS AND A FEW TSTMS HAVE DEVELOPED IN AN AREA OF SURFACE MOISTURE CONVERGENCE AND INSTABILITY NEAR THE COAST AND HAVE MOVED INLAND. HAVE RAISED POPS TO CHC OVER ROUGHLY THE EASTERN THIRD OR SO OF THE CWA. RAP INDICATES THESE SHOWERS WILL AROUND FOR ALOT OF MORNING...WITH ADDITIONAL ISOLATED SHOWERS AND TSTMS THIS AFTERNOON WITH THE SEA BREEZE. NO CHANGES TO FORECAST TEMPERATURES MAINLY IN THE UPPER 80S TO AROUND 90 TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... AS OF 3 AM SATURDAY...THE COMBINATION OF A MOIST ONSHORE FLOW AND SOME WEAK MID-LEVEL VORTICITY MAY LEAD TO A REPEAT OF THIS MORNING WITH A FEW SHOWERS ALONG THE COAST IN THE OVERNIGHT HOURS AND WILL HAVE A SLIGHT CHC POP. OTHERWISE...A PARTLY CLOUDY WARM AND MUGGY NIGHT WITH MIN TEMPS IN THE 73 TO 78 DEGREE RANGE. && .LONG TERM /SUNDAY THROUGH FRIDAY/... AS OF 330 AM SATURDAY...LONG TERM MODELS STILL IN GENERALLY GOOD AGREEMENT ON SYNOPTIC REGIME THROUGH THE COMING WEEK. BERMUDA HIGH WILL REMAIN SOUTH AND EAST OF THE REGION...WHILE BROAD TROUGH EXISTS ACROSS EASTERN HALF OF CONUS. FLOW WILL REMAIN SOUTHWESTERLY... SUPPLYING E NC WITH WARM AND HUMID CONDITIONS...WHILE WEAK SHORTWAVES AND STATIONARY FRONT ACROSS CENTRAL NC BRINGS CHANCES FOR CONVECTIVE ACTIVITY EACH DAY. BEST CHANCES FOR THUNDERSTORMS WILL BE IN THE AFTERNOON HOURS...THOUGH RAIN CHANCES MAY LINGER THROUGH THE EVENING HOURS. BEST CHANCES FOR WIDESPREAD RAIN AND STORMS WILL BE AROUND MID TO LATE WEEK TIME FRAME. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... /SHORT TERM TODAY AND TONIGHT/... AS OF 7 AM SAT...SOME MVFR FOG HAS DEVELOPED AT ALL OF THE TAF SITES AND VSBY HAS BEEN BOUNCING UP AND DOWN FOR THE PAST COUPLE OF HOURS. THIS FOG SHOULD DISSIPATE BY ABOUT 13Z WITH ANOTHER ROUND OF ISOLATED DIURNAL CONVECTION EXPECTED AGAIN IN THE AFTERNOON. SIMILAR PATTERN EXPECTED TONIGHT WITH A FEW SHOWERS DEVELOPING NEAR THE COAST...BUT OVERALL MVFR CONDITIONS EXPECTED WITH SOME PATCHY FOG TOWARD MORNING ON SUNDAY. /LONG TERM SUNDAY THROUGH WEDNESDAY/... AS OF 330 AM SATURDAY...MAINLY VFR CONDITIONS WILL PREVAIL...THOUGH AS IS THE CASE MOST EVENING...SOME REDUCTIONS TO MVFR/IFR POSSIBLE LATE AS RADIATION FOG/LOW STRATUS DEVELOPS...ESP IN AREAS THAT RECEIVE RAINFALL. SCT MAINLY AFTERNOON THUNDERSTORMS WILL BRING TEMPO REDUCTIONS IN VSBYS THROUGH THE COMING WEEK. && .MARINE... /SHORT TERM TODAY AND TONIGHT/... AS OF 7 AM SATURDAY...CURRENT BUOY OBSERVATIONS CONTINUE TO INDICATE S/SW WINDS OF 12 KNOTS OR LESS WITH SEAS 2 TO 3 FEET WITH A 7 TO 8 SECOND SWELL COMPONENT. A FEW SHOWERS MOVING ALONG THE COAST MAY BRIEFLY CAUSE SOME GUSTINESS TO ABOUT 18 KNOTS OR SO. S/SW WINDS WILL CONTINUE TO CIRCULATE AROUND HIGH PRESSURE TO THE EAST TODAY AND TONIGHT WITH FRONTAL BOUNDARY REMAINING WELL OFF TO THE WEST IN THE OHIO VALLEY. THIS WILL LEAD TO S/SW WINDS 10 TO 15 KNOTS WITH SEAS 2 TO 3 FEET THROUGH TONIGHT. /LONG TERM SUNDAY THROUGH WEDNESDAY/... AS OF 330 AM SATURDAY...SOUTHWEST FLOW WILL CONTINUE THROUGH THE LONG TERM...WITH WINDS GENERALLY 10 TO 15 KNOTS OVER THE WATERS... AND AROUND 10 KT OVER THE SOUNDS. SEAS WILL REMAIN IN THE 3 TO 4 FT RANGE ACROSS OUTER WATERS WITH 2 TO 3 FEET NEARSHORE. THERE WILL BE CHANCES FOR THUNDERSHOWERS THROUGH THE COMING WEEK AS A COOL FRONT AND TROUGH SAGS INTO CENTRAL AND EASTERN NC AND STALLS OUT NEARBY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...CTC NEAR TERM...CTC SHORT TERM...CTC LONG TERM...TL AVIATION...CTC/TL MARINE...CTC/TL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
340 AM EDT SAT AUG 4 2012 .SYNOPSIS... BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AS OF 330 AM SATURDAY...LOOK FOR MORE OF A TROPICAL INFLUENCE ACROSS REGION THIS FORECAST PERIOD. THE WESTERN ATLANTIC HIGH TO RIDGE ACROSS THE FA BOTH SFC AND ALOFT THRU THE PERIOD. AN INVERTED SFC TROF TO PASS OVER THE BAHAMAS TODAY...AND TRACK NW TO AND ACROSS THE NORTHERN FLORIDA PENINSULA TONIGHT INTO SUNDAY. HOURLY NAMBUFR SOUNDINGS INDICATE A GENERAL INCREASE OF PWS TO AROUND 2 INCHES TONIGHT INTO SUNDAY. WINDS THRU THE ATM COLUMN TO BECOME BASICALLY ONSHORE INDICATIVE OF A TROPICAL INFLUENCE ACROSS THE FA. THE SEA BREEZE OR RESULTANT WIND TYPE CONVECTION WILL COMMENCE BY MID-LATE THIS MORNING...AND TRACK INLAND THROUGHOUT THE DAY AS ADVERTIZED BY THE LATEST HRRR MODEL RUNS. MODEL SOUNDING DATA INDICATE PWS OF 2 INCHES...AND A SLOW MOVEMENT OF THE CONVECTION...BASICALLY BETWEEN 5 AND 10 KT. AS A RESULT...THE MAIN THREAT FROM TODAYS CONVECTION WILL BE FROM HEAVY RAIN. FOR TONIGHT...ONSHORE MOVEMENT OF PCPN DURING THE PRE-DAWN HRS OF SUNDAY TO OCCUR AS A MUCH DEEPER ONSHORE FLOW TO EVOLVE THRU THE ATM COLUMN. WILL ILLUSTRATE LOW CHANCE POPS FOR THE COASTAL AREAS. COMPROMISED BETWEEN THE VARIOUS MODEL MOS GUIDANCE FOR MAX/MIN TEMPS THRUOUT THE NEAR TERM. && .SHORT TERM /SUNDAY MORNING THROUGH MONDAY NIGHT/...AS OF 3:00 AM SATURDAY...MID LEVEL RIDGING WILL CONTINUE TO BE THE MAIN WEATHER MAKER SUNDAY. MONDAY WILL FEATURE A SLIGHT CHANGE AS THE RIDGE RETREATS TO THE EAST AND A FRONT MOVES AT LEAST CLOSER TO THE AREA FROM THE NORTHWEST. THIS ALLOWS POPS TO INCREASE FROM ISOLATED/SLIGHT CHANCE SUNDAY TO CHANCE MONDAY PRIMARILY MONDAY AFTERNOON. THERMAL PROFILES ARE ALMOST IDENTICAL FOR BOTH AFTERNOONS AND MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON DAYTIME HIGHS ALMOST SPOT ON CLIMATOLOGY WITH OVERNIGHT LOWS JUST ABOVE. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 3:00 AM SATURDAY...MID LEVEL PATTERN WILL FEATURE SUBTLE EAST COAST TROUGHING WITH RIDGING CENTERED ACROSS THE ROCKIES AND ACROSS THE CENTRAL ATLANTIC. AT THE SURFACE A WEAK FRONT/PIEDMONT TROUGH WILL BE THE FEATURES OF NOTE. THE FRONT APPEARS TO STALL AS WOULD BE EXPECTED THIS TIME OF YEAR TO THE WEST/NORTHWEST. TOUGH TO ASCERTAIN WHICH DAY WILL FEATURE THE BEST CHANCE FOR RAIN AND BASICALLY MAINTAINED THE DIURNAL CYCLE AND CHANCE VALUES. IF ANYTHING...THURSDAY AND FRIDAY APPEAR SLIGHTLY MORE CONDUCIVE PER THE FAVORED ECMWF HIGH RESOLUTION FROM HPC. NO CHANGES TO TEMPERATURE FORECAST WHICH SHOULD HOVER AROUND CLIMATOLOGY. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... AS OF 06Z...EXPECT MVFR AND/OR IFR VSBYS FROM BR/FG DURING THE 08Z-13Z TIME FRAME. FLO AND/OR LBT TERMINALS WILL HAVE THE GREATER POTENTIAL TO OBSERVE PREVAILING BR/FG...WHEREAS THE COASTAL TERMINALS WILL INDICATE TEMPO MVFR VSBYS. COULD OBSERVE A SUB-1000 FT CLOUD DECK ALONG THE COASTAL TERMS WITHIN A 4 HR WINDOW SURROUNDING SUNRISE. BY MID-MORNING...ANY RESIDUAL BR SHOULD DISSIPATE...LEAVING VFR CONDITIONS FOR THE REMAINDER OF THE DAY. THE PROB OF THUNDERSTORMS REMAINS ON THE LOW SIDE...BUT ENOUGH CONFIDENCE TO MENTION VCTS AT ALL TERMINALS FROM MIDDAY THROUGH EARLY THIS EVENING. PREVAILING SE-S WINDS AT 5 TO 10 KT EXPECTED...UP TO 15 KT AT THE COASTAL TERMINALS. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR/IFR VSBYS FROM BR/FG WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 330 AM SATURDAY...THE WESTERN ATLANTIC HIGH...SFC AND ALOFT... WILL GOVERN THE ILM COASTAL WATERS. THE SFC RIDGE AXIS EXTENDING SW FROM THE CENTER OF THIS HIGH...WILL CROSS THE WATERS THRU THE PERIOD. THE ACTUAL POSITIONING OF THIS AXIS ACROSS THE LOCAL WATERS WILL DETERMINE WIND DIRECTIONS. LOOK FOR SE TO S WIND DIRECTIONS SOUTH OF THE AXIS AND S TO SSW NORTH OF THE AXIS. THE SFC PG WILL BE CONDUCIVE FOR 10-15 KT WIND SPEEDS. WILL HAVE TO MONITOR THE STRENGTH AND MOVEMENT OF AN INVERTED TROF OF LOW PRESSURE FROM THE BAHAMAS TO AND ACROSS THE FLORIDA PENINSULA SUNDAY. WIND SPEEDS MAY INCREASE TO A SOLID 15 KT SOUTH OF CAPE FEAR. SIGNIFICANT SEAS WILL BE RULED BY A 2 TO 3 FT ESE GROUND SWELL EXHIBITING 8-9 SECOND PERIODS. FOR TONIGHT...SIG SEAS TO BUILD TO 3 TO 4 FT DUE TO THE CLOSER PROXIMITY OF THE EFFECTS FROM THE INVERTED SFC TROF. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 3:00 AM SATURDAY...BERMUDA HIGH PRESSURE AND SEA BREEZE WILL DOMINATE THE COASTAL WATERS THROUGH THE PERIOD WITH SLIGHTLY MORE INFLUENCE FROM A FRONT MOVING CLOSER LATE MONDAY. WIND SPEEDS MAY ADD A KNOT OR TWO AT THIS TIME. SEAS ARE RATHER UNEVENTFUL AS WELL WITH 2-3 FEET FOR THE MOST PART. A FEW FOUR FOOTERS CANNOT BE RULED OUT EARLY ACROSS THE OUTER WATERS. LONG TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 3:00 AM SATURDAY...SUMMERTIME PATTERN CONTINUES ACROSS THE COASTAL WATERS FOR THE MARINE COMMUNITY. SOUTHWEST WINDS OF 10-15 KNOTS WILL PREVAIL WITH A SLIGHT BACKING DURING THE DAY COURTESY OF THE SEA BREEZE. NO REAL SIGNAL FROM TROPICAL ACTIVITY VIA THE WAVEWATCH GUIDANCE AS SEAS REMAIN IN A 2-4 FOOT RANGE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...DCH SHORT TERM...SHK LONG TERM...SHK AVIATION...DCH/MRR
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
329 AM EDT SAT AUG 4 2012 .SYNOPSIS... HIGH PRESSURE WILL BUILD IN FROM THE EAST THROUGH THE WEEKEND. A COLD FRONT WILL APPROACH FROM THE WEST MONDAY AND TUESDAY BUT WILL STALL AND WEAKEN WEST OF THE AREA WEDNESDAY THROUGH LATE NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 3 AM SATURDAY...LATEST RAP MODEL ALONG THE NAM12/GFS SHOW A THREAT OF SOME SHOWERS AND POSSIBLE TSTMS WILL AFFECT THE COAST DURING THE EARLY MORNING HOURS AS STRONG MID-LEVEL VORT CENTER TRACKS UP THE CAROLINA COAST IN AN UPPER-LEVEL WEAKNESS. RADAR ALREADY SHOWING SOME SHOWERS DEVELOPING ABOUT 100 MILES DUE SOUTH OF THE CRYSTAL COAST...SO HAVE RAISED POPS TO LOW CHC ALONG THE COAST THROUGH MIDDAY. ADDITIONAL ISOLATED SHOWERS WITH A FEW TSTMS MAY OCCUR ALONG THE SEA BREEZE LATER THIS AFTERNOON AND WILL HAVE A SLIGHT CHC ALONG THE SEA BREEZE ZONE AT THAT TIME. MAX TEMPS SHOULD MAINLY BE IN THE UPPER 80S TO AROUND 90 UNDER PARTLY CLOUDY SKIES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... AS OF 3 AM SATURDAY...THE COMBINATION OF A MOIST ONSHORE FLOW AND SOME WEAK MID-LEVEL VORTICITY MAY LEAD TO A REPEAT OF THIS MORNING WITH A FEW SHOWERS ALONG THE COAST IN THE OVERNIGHT HOURS AND WILL HAVE A SLIGHT CHC POP. OTHERWISE...A PARTLY CLOUDY WARM AND MUGGY NIGHT WITH MIN TEMPS IN THE 73 TO 78 DEGREE RANGE. && .LONG TERM /SUNDAY THROUGH FRIDAY/... AS OF 330 AM SATURDAY...LONG TERM MODELS STILL IN GENERALLY GOOD AGREEMENT ON SYNOPTIC REGIME THROUGH THE COMING WEEK. BERMUDA HIGH WILL REMAIN SOUTH AND EAST OF THE REGION...WHILE BROAD TROUGH EXISTS ACROSS EASTERN HALF OF CONUS. FLOW WILL REMAIN SOUTHWESTERLY... SUPPLYING E NC WITH WARM AND HUMID CONDITIONS...WHILE WEAK SHORTWAVES AND STATIONARY FRONT ACROSS CENTRAL NC BRINGS CHANCES FOR CONVECTIVE ACTIVITY EACH DAY. BEST CHANCES FOR THUNDERSTORMS WILL BE IN THE AFTERNOON HOURS...THOUGH RAIN CHANCES MAY LINGER THROUGH THE EVENING HOURS. BEST CHANCES FOR WIDESPREAD RAIN AND STORMS WILL BE AROUND MID TO LATE WEEK TIME FRAME. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... /SHORT TERM TODAY AND TONIGHT/... AS OF 1 AM SAT...SOME MVFR FOG HAS DEVELOPED AT KEWN AND KISO AND GIVEN LIGHT SE FLOW AND MOIST BOUNDARY LAYER EXPECT SOME PATCHY FOG THROUGH THE EARLY MORNING HOURS. SAT WILL SEE CONTINUED S FLOW WITH ISOLATED DIURNAL CONVECTION EXPECTED AGAIN IN THE AFTERNOON. /LONG TERM SUNDAY THROUGH WEDNESDAY/... AS OF 330 AM SATURDAY...MAINLY VFR CONDITIONS WILL PREVAIL...THOUGH AS IS THE CASE MOST EVENING...SOME REDUCTIONS TO MVFR/IFR POSSIBLE LATE AS RADIATION FOG/LOW STRATUS DEVELOPS...ESP IN AREAS THAT RECEIVE RAINFALL. SCT MAINLY AFTERNOON THUNDERSTORMS WILL BRING TEMPO REDUCTIONS IN VSBYS THROUGH THE COMING WEEK. && .MARINE... /SHORT TERM TODAY AND TONIGHT/... AS OF 310 AM SATURDAY...WINDS HAVE DROPPED A BIT IN THE PAST COUPLE OF HOURS AND ARE GENERALLY 12 KNOTS OR LESS FROM THE S/SW WITH SEAS AT 1 TO 3 FEET WITH 7 TO 8 SECOND SWELLS. NOT PLANNING ANY MAJOR CHANGES TO MARINE FORECAST AS S/SW WINDS WILL CONTINUE TO CIRCULATE AROUND HIGH PRESSURE TO THE EAST WITH FRONTAL BOUNDARY REMAINING WELL OFF TO THE WEST IN THE OHIO VALLEY. THIS WILL LEAD TO S/SW WINDS 10 TO 15 KNOTS WITH SEAS 2 TO 3 FEET THROUGH TONIGHT. /LONG TERM SUNDAY THROUGH WEDNESDAY/... AS OF 330 AM SATURDAY...SOUTHWEST FLOW WILL CONTINUE THROUGH THE LONG TERM...WITH WINDS GENERALLY 10 TO 15 KNOTS OVER THE WATERS... AND AROUND 10 KT OVER THE SOUNDS. SEAS WILL REMAIN IN THE 3 TO 4 FT RANGE ACROSS OUTER WATERS WITH 2 TO 3 FEET NEARSHORE. THERE WILL BE CHANCES FOR THUNDERSHOWERS THROUGH THE COMING WEEK AS A COOL FRONT AND TROUGH SAGS INTO CENTRAL AND EASTERN NC AND STALLS OUT NEARBY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...CTC NEAR TERM...CTC SHORT TERM...CTC LONG TERM...TL AVIATION...CTC/TL MARINE...CTC/TL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
102 AM EDT SAT AUG 4 2012 .SYNOPSIS... WEAK UPPER LEVEL LOW PRESSURE WILL GRADUALLY LIFT OUT TONIGHT AS HIGH PRESSURE BUILDS WEST INTO THE AREA FROM OFFSHORE THROUGH THE WEEKEND. A COLD FRONT WILL APPROACH FROM THE NORTHWEST MONDAY AND STALL ACROSS THE PIEDMONT INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1255 AM SATURDAY...SIGNALS IN SEVERAL OF THE SHORT-TERM MODELS INDICATE A DECENT MID-LEVEL SHORTWAVE TO MOVE NORTH ACROSS EASTERN NORTH CAROLINA IN WEAKNESS BETWEEN AREAS OF HIGH PRESSURE WELL TO THE EAST AND OVER THE SOUTHERN PLAINS. THE RAP/GFS AND TO A LESSER EXTENT THE NAM ALL SHOW LIGHT QPF NEAR THE COAST FROM ABOUT 10Z THIS MORNING INTO EARLY AFTERNOON. HAVE FOLLOWED SUIT WITH CHANCE POPS NEAR THE COAST TAPERING TO NIL WEST OF HIGHWAY 17 THROUGH EARLY AFTERNOON. NO OTHER MAJOR CHANGES TO THE FORECAST AT THIS TIME. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/... AS OF 340 PM FRI...UPPER LEVEL RIDGE BEGINS TO MIGRATE WEST INTO EASTERN NC ON SAT ALTHOUGH LOW LEVEL THICKNESSES CHANGE LITTLE...RANGING 1415-1420 METERS WHICH WILL YIELD MAX TEMPS IN THE LOWER 90S INLAND TO UPPER 80S ALONG THE COAST. FORECAST SOUNDINGS INDICATE AN UNSTABLE AIRMASS WILL PERSIST SAT WITH PWATS OVER 1.75 INCHES...CAPE VALUES ABOVE 3000 J/KG AND LIFTED INDICES OF -7 TO -9 C. CONTINUED FORECAST FOR DIURNAL CONVECTION INLAND ASSOCIATED WITH SEA BREEZE BOUNDARY PROPAGATION FOR THE AFTERNOON HOURS. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... AS OF 155 PM FRI...MODELS IN GOOD AGREEMENT IN THE LONG TERM. WARM AND HUMID THROUGH THE PERIOD WITH THE BERMUDA HIGH RIDGING ACROSS THE SOUTHEAST MAINTAINING A SOUTHWEST FLOW. A COLD FRONT WILL APPROACH FROM THE NORTHWEST EARLY NEXT WEEK BUT WILL BECOME STATIONARY OVER THE CENTRAL PART OF THE STATE. THE FRONT WILL DISSIPATE BY MIDWEEK LEAVING A WEAK SURFACE THROUGH THROUGH FRIDAY. TYPICAL SUMMERTIME WEATHER WITH SCATTERED MAINLY DIURNAL SHOWERS AND THUNDERSTORMS. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... SHORT TERM /THROUGH 00Z SUNDAY/... AS OF 1 AM SAT...SOME MVFR FOG HAS DEVELOPED AT KEWN AND KISO AND GIVEN LIGHT SE FLOW AND MOIST BOUNDARY LAYER EXPECT SOME PATCHY FOG THROUGH THE EARLY MORNING HOURS. SAT WILL SEE CONTINUED S FLOW WITH ISOLATED DIURNAL CONVECTION EXPECTED AGAIN IN THE AFTERNOON. LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/ AS OF 150 PM FRI...SOUTHWEST SURFACE FLOW WILL PERSIST THROUGH THE PERIOD...GENERALLY 10-15 KNOTS BY DAY AND LESS THAN 10 KNOTS AT NIGHT. SCATTERED MAINLY AFTERNOON/EVENING THUNDERSTORMS WITH LOCALLY LOWER CEILINGS/VISIBILITIES. && .MARINE... SHORT TERM /THROUGH SATURDAY/... AS OF 1 AM SAT...WINDS ARE RUNNING JUST A BIT ABOVE FORECAST VALUES WITH OBSERVED VALUES NEAR 15 KNOTS AT OREGON INLET...DIAMOND BUOY AND CAPE LOOKOUT. HAVE UPPED THE WINDS BASED ON THE LATEST RAP MODEL. SEAS REMAIN IN THE 2 TO 3 FEET RANGE AND NO CHANGES NEEDED TO THE WAVEHEIGHT FORECAST. LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/ AS OF 150 PM FRI...LATEST RUNS OF THE ECMWF/GFS/NAM IN VERY CLOSE AGREEMENT THROUGH THE LONG TERM PERIOD SO USED AN OVERALL BLEND. THE BERMUDA HIGH WILL BE THE MAIN FEATURE IN THE WEATHER MAINTAINING A SOUTHWEST FLOW BUT SPEEDS AND SEAS WILL REMAIN BELOW SMALL CRAFT LEVELS. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...DAG NEAR TERM...CTC SHORT TERM...DAG LONG TERM...HSA AVIATION...CTC/HSA/JBM MARINE...CTC/HSA
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
355 PM EDT SAT AUG 4 2012 .SYNOPSIS... MUGGY AUGUST AIR THROUGH WEEKEND. WITH A LOCAL DOWNPOUR POSSIBLE. MORE WIDESPREAD AND ORGANIZED CONVECTION LIKELY SUNDAY...WELL AHEAD OF COLD FRONT. DRIER AIR TRIES TO CREEP SOUTH MONDAY. && .NEAR TERM /THROUGH SUNDAY/... CONVECTION CURRENTLY DEVELOPING IN ASSOCIATION WITH WEAK VORT MAX SHOWING UP ON RAP MOVING INTO CWA FROM THE WEST. DOWNPOURS WILL BE POSSIBLE WITH THESE STORMS...AND ISOLATED FLASH FLOODING MAY OCCUR. NOT EXPECTING FLASH FLOOD THREAT TO BE WIDESPREAD ENOUGH TO WARRANT A SHORT FLASH FLOOD WATCH THOUGH THIS EVENING. TOMORROW IS ANOTHER STORY...MOISTURE CONTINUES TO INCREASE OVERNIGHT...WITH PWAT VALUES CLIMBING TO OVER 2.25 INCHES BY 18Z SUNDAY ON THE NAM AND GFS. EXPECT WIDESPREAD PRECIPITATION...WITH VERY HEAVY RAINFALL SUNDAY AFTERNOON INTO SUNDAY NIGHT...AND OPTED TO ISSUE A FLASH FLOOD WATCH FOR LINE ROUGHLY HTS TO CKB AND SOUTH. ONE THING TO WATCH WILL BE STORM SPEEDS...WITH 20-30KTS MID LEVEL FLOW...STORMS WILL BE PROGRESSIVE...BUT WITH FLASH FLOOD GUIDANCE BETWEEN 1.5 AND 2 INCHES ACROSS A LOT OF THE WATCH AREA...EVEN STORMS THAT ARE MOVING COULD EASILY REACH THIS THRESHOLD. PLUS...IF ANY TRAINING CELLS OCCUR THREAT WILL INCREASE GREATLY. AS FOR SEVERE THREAT...MODELS HAVE BEEN BACKING OFF ON INSTABILITY A BIT. THINK THIS IS A GOOD TREND...DUE TO MORE CLOUDS LEADING TO LESS HEATING. STILL...1500-2000 J/KG CAPE SHOULD BE ENOUGH TO TAP INTO GOOD MID-LEVEL FLOW AND PRODUCE STRONG TO SEVERE WIND GUSTS IN THE TALLER STORMS. BLENDED IN MET GUIDANCE FOR TEMPS OVERNIGHT...AS IT HAS BEEN PERFORMING QUITE WELL LATELY...WHICH RESULTED IN MINIMAL CHANGES. WITH MORE CLOUDS AROUND...BLENDED IN THE MAV FOR HIGHS TOMORROW LIKING ITS DEPICTION OF COOLER TEMPS IN SE OHIO WHERE PRECIP WILL REACH FIRST. THIS RESULTED OVERALL IN A BIT COOLER DAY THAN PREVIOUS FORECAST. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... WE ARE HOPING THE PREFRONTAL CONVECTION DOES NOT ORIENT MORE EAST TO WEST...BUT THE FLASH FLOOD WATCH WAS POSTED EARLY...FOR THAT POSSIBILITY. AS WE HEAD INTO SUNDAY EVENING...OUR SOUTHERN COUNTIES SEEM TO BE MORE VULNERABLE TO SOME TRAINING...DESPITE THE 25 TO 30 KNOT CELL MOVEMENT THAT WE ARE EXPECTED. WILL BASE FORECAST ON SURFACE FRONT FROM NEAR EKN TO CRW TO SOUTH OF HTS AT 12Z MONDAY. SO HAD TO LEAVE SOME CHANCE POPS ALONG THAT FEATURE. PICTURING LOW CLOUDS ALONG THAT FRONT TOO. PROBABLY MOSTLY JUST LINGERING RAIN SHOWERS RATHER THAN THUNDER. PROBLEM THEN BECOMES...HOW LONG TO LINGER SOME 20/30 POPS IN OUR EXTREME SOUTH INTO TUESDAY. WE ARE TYPICALLY LEARY OF THE DRIER AIR IN THE LOW LEVELS MAKING IT THROUGH THE SOUTHERN MOUNTAINS. SO EVEN THOUGH THE MID LEVELS SHOULD DRY OUT...WILL NOW HOLD ONTO SOME 20/30 POPS IN SW VIRGINIA TO NEAR BECKLEY FOR TUESDAY. THERE COULD BE WIDESPREAD FOG MONDAY NIGHT FROM EKN TO CRW INTO THE COAL FIELDS. YET...BEING THE THIRD NIGHT INTO THE FUTURE...WILL HOLD OFF INCLUDING THOSE SPECIFICS FOR NOW. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... 12Z GFS AND 12Z ECMWF SOLUTIONS CONTINUE TO AGREE THAT THE MID LEVEL RIDGE...BAKING THE PLAINS THIS SUMMER...WILL SLIDE BACK WEST INTO THE GREAT BASIN...WITH A STRONG TROF SWINGING THROUGH OUR VICINITY ON DAY 7...WITH THE SURFACE FRONT LIKELY AHEAD OF IT...ON DAY 6/FRIDAY. PROBLEM FOR WEDNESDAY AND THURSDAY IS THE DEEP MOISTURE LINGERING TO OUR SOUTHEAST. WILL TRY TO HOLD WEDNESDAY DRY MAINLY FOR COUNTIES NORTH OF A HTS-CRW-EKN LINE...WITH SOME 20/30 POPS ALONG OUR SOUTHEASTERN COUNTIES WEDNESDAY. WENT ALONG WITH HPC MEDIUM RANGE CHANCE POPS FOR THURSDAY AND FRIDAY...WITH A COOL DOWN FOR SATURDAY. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... CONVECTION JUST BEGINNING TO FORM ACROSS THE EASTERN MOUNTAINS...AND ALSO IN EASTERN KY. EXPECT ADDITIONAL DEVELOPMENT THROUGH THE AFTERNOON...WITH SCATTERED SHOWERS AND THUNDERSTORMS LINGERING INTO THE EVENING. KEPT EVERYTHING VFR FOR TODAY...HOWEVER BRIEF MVFR IS POSSIBLE IN THE STRONGER CELLS. WITH MORE CLOUDS AND SOME WIND REMAINING OVERNIGHT...DO NOT EXPECT DENSE FOG TO FORM. WILL INCLUDED MVFR FOG TONIGHT IN MOST SHELTERED MOUNTAIN VALLEYS LIKE KEKN. TOWARDS THE END OF THE TAF PERIOD...EXPECT SHOWERS AND THUNDERSTORMS...WITH HEAVY RAIN POSSIBLE...TO BE ON THE INCREASE FROM WEST TO EAST AS COLD FRONT APPROACHES. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY... FORECAST CONFIDENCE: MEDIUM TO HIGH. ALTERNATE SCENARIOS: TIMING OF SHOWERS AND THUNDERSTORMS TODAY MAY VARY...WITH AMENDMENTS POSSIBLE. ADDITIONAL POCKETS OF FOG MAY FORM OVERNIGHT IF CLOUD BREAKS DEVELOP. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 EDT 1HRLY 16 17 18 19 20 21 22 23 00 01 02 03 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H M M H H H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 18Z SUNDAY... BRIEF IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS INTO SUNDAY NIGHT. IFR IN LOW STRATUS POSSIBLE NEAR SURFACE FRONT MONDAY MORNING. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR WVZ005-006-013>020-024>040-046-047. OH...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR OHZ087. KY...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR KYZ101>103-105. VA...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR VAZ003-004. && $$ SYNOPSIS...KTB/MZ NEAR TERM...MZ SHORT TERM...KTB/ARJ LONG TERM...KTB AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
225 PM EDT SAT AUG 4 2012 .SYNOPSIS... WARM AND HUMID...WITH SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED THIS AFTERNOON. A COLD FRONT BRINGS WIDESPREAD AND STRONGER STORMS...WITH HEAVY RAIN AND SEVERE WEATHER SUNDAY AND SUNDAY NIGHT. && .NEAR TERM /THROUGH SUNDAY/... CONVECTION CURRENTLY DEVELOPING IN ASSOCIATION WITH WEAK VORT MAX SHOWING UP ON RAP MOVING INTO CWA FROM THE WEST. DOWNPOURS WILL BE POSSIBLE WITH THESE STORMS...AND ISOLATED FLASH FLOODING MAY OCCUR. NOT EXPECTING FLASH FLOOD THREAT TO BE WIDESPREAD ENOUGH TO WARRANT A SHORT FLASH FLOOD WATCH THOUGH THIS EVENING. TOMORROW IS ANOTHER STORY...MOISTURE CONTINUES TO INCREASE OVERNIGHT...WITH PWAT VALUES CLIMBING TO OVER 2.25 INCHES BY 18Z SUNDAY ON THE NAM AND GFS. EXPECT WIDESPREAD PRECIPITATION...WITH VERY HEAVY RAINFALL SUNDAY AFTERNOON INTO SUNDAY NIGHT...AND OPTED TO ISSUE A FLASH FLOOD WATCH FOR LINE ROUGHLY HTS TO CKB AND SOUTH. ONE THING TO WATCH WILL BE STORM SPEEDS...WITH 20-30KTS MID LEVEL FLOW...STORMS WILL BE PROGRESSIVE...BUT WITH FLASH FLOOD GUIDANCE BETWEEN 1.5 AND 2 INCHES ACROSS A LOT OF THE WATCH AREA...EVEN STORMS THAT ARE MOVING COULD EASILY REACH THIS THRESHOLD. PLUS...IF ANY TRAINING CELLS OCCUR THREAT WILL INCREASE GREATLY. AS FOR SEVERE THREAT...MODELS HAVE BEEN BACKING OFF ON INSTABILITY A BIT. THINK THIS IS A GOOD TREND...DUE TO MORE CLOUDS LEADING TO LESS HEATING. STILL...1500-2000 J/KG CAPE SHOULD BE ENOUGH TO TAP INTO GOOD MID-LEVEL FLOW AND PRODUCE STRONG TO SEVERE WIND GUSTS IN THE TALLER STORMS. BLENDED IN MET GUIDANCE FOR TEMPS OVERNIGHT...AS IT HAS BEEN PERFORMING QUITE WELL LATELY...WHICH RESULTED IN MINIMAL CHANGES. WITH MORE CLOUDS AROUND...BLENDED IN THE MAV FOR HIGHS TOMORROW LIKING ITS DEPICTION OF COOLER TEMPS IN SE OHIO WHERE PRECIP WILL REACH FIRST. THIS RESULTED OVERALL IN A BIT COOLER DAY THAN PREVIOUS FORECAST. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/... A COLD FRONT APPROACHES TO SOUTHEAST OH SUNDAY. MODELS ARE IN GOOD AGREEMENT TIGHTENING THE PRESSURE GRADIENT AND FLOW AT H850 FROM THE SOUTHWEST...AND BRINGING MOISTURE ADVECTION TO THE AREA EARLY SUNDAY MORNING. THETA-E VALUES REACHING 340K SUGGEST VERY JUICY AIR CAPABLE TO PRODUCE HEAVY RAIN AND STRONG STORMS WILL SPREAD EAST ACROSS WV DURING THE PEAK OF DIURNAL HEATING. THIS MOISTURE IS ALSO NOTED IN PRECIPITABLE WATER VALUES EXCEEDING 2.2 INCHES. ALTHOUGH EQUILIBRIUM LEVEL EXCEEDING 40 KFT...A THIN CAPE SOUNDING AND LOW UNIDIRECTIONAL DEEP LAYERED SHEAR VALUES SUGGEST WATER LOADING EFFECTS WITH TALL STORMS. THESE CONDITIONS COULD REDUCE SEVERE UPDRAFTS...BUT WILL PROMOTE VERY HEAVY DOWNPOURS. STRONG H5 VORTICITY MAXIMUM REACHES SOUTHEAST OH BY MON 00Z...SUGGESTING GOOD DYNAMICS COULD ENHANCE STORMS DURING THE AFTERNOON HOURS. THEREFORE...EXPECT CONVECTION FIRING UP AHEAD OF THE FRONT BY MID DAY SUNDAY...AND SPREAD EAST NORTHEAST...WITH CONTINUING CONVECTION DEVELOPING ACROSS SOUTHEAST OH WITH THE STRONGER UPPER FORCING APPROACHING THROUGH THE EVENING. ALTHOUGH THERE IS A SLIGHT RISK FOR SEVERE STORMS ACROSS THE ENTIRE AREA...WILL ALSO WATCH FOR WATER PROBLEMS WITH THE AFOREMENTIONED SCENARIO. KEPT CAP POPS SUNDAY AFTERNOON ACROSS SOUTHEAST OH...SPREADING EAST THROUGH SUNDAY NIGHT. THE FRONT SEEMS TO SLOW DOWN AS IT ENTERS WV...AND LINGER ACROSS THE SOUTHERN COAL FIELDS AND CENTRAL MOUNTAINS THROUGH TUESDAY MORNING. A FLASH FLOOD WATCH MAY BE REQUIRED FOR SUNDAY. KEPT HIGH TEMPS IN THE 80S SUNDAY AND MONDAY PER ABUNDANT CLOUDS AND RAINFALL EXPECTED. KEPT LOWS IN THE LOWER 70S SUNDAY NIGHT PER ABUNDANT MOISTURE AND LACK OF EXTRA PUSH OF DRIER AIR TO DISPLACE HIGH DEWPOINTS...BUT IN THE MID 60S MONDAY NIGHT PER CLEARING SPREADING FROM THE WEST AND ASSOCIATED RADIATIONAL COOLING. AREAS OF DENSE FOG WILL BE POSSIBLE UNDER CLEAR SKIES AND AREAS THAT RECEIVE RAINFALL TUESDAY MORNING. && .LONG TERM /TUESDAY THROUGH SATURDAY/... GOING WITH HPC. NORTHWEST FLOW ALOFT STRENGTHENS...WITH THE HOT AND HUMID AIR BEING SHUNTED TO THE SOUTH. TRANQUIL PERIOD OF DRY AND NEAR SEASONABLE TEMPERATURES DOMINATE THIS PERIOD AS WEAK HIGH PRESSURE DOMINATES. GOOD MODEL AGREEMENT ON THIS SCENARIO. BY FRIDAY...NEXT SYSTEM APPROACHES AS THE UPPER FLOW BECOMES MORE WESTERLY AND ALLOWS THE HEAT AND MOISTURE TO RETURN. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... CONVECTION JUST BEGINNING TO FORM ACROSS THE EASTERN MOUNTAINS...AND ALSO IN EASTERN KY. EXPECT ADDITIONAL DEVELOPMENT THROUGH THE AFTERNOON...WITH SCATTERED SHOWERS AND THUNDERSTORMS LINGERING INTO THE EVENING. KEPT EVERYTHING VFR FOR TODAY...HOWEVER BRIEF MVFR IS POSSIBLE IN THE STRONGER CELLS. WITH MORE CLOUDS AND SOME WIND REMAINING OVERNIGHT...DO NOT EXPECT DENSE FOG TO FORM. WILL INCLUDED MVFR FOG TONIGHT IN MOST SHELTERED MOUNTAIN VALLEYS LIKE KEKN. TOWARDS THE END OF THE TAF PERIOD...EXPECT SHOWERS AND THUNDERSTORMS...WITH HEAVY RAIN POSSIBLE...TO BE ON THE INCREASE FROM WEST TO EAST AS COLD FRONT APPROACHES. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY... FORECAST CONFIDENCE: MEDIUM TO HIGH. ALTERNATE SCENARIOS: TIMING OF SHOWERS AND THUNDERSTORMS TODAY MAY VARY...WITH AMENDMENTS POSSIBLE. ADDITIONAL POCKETS OF FOG MAY FORM OVERNIGHT IF CLOUD BREAKS DEVELOP. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05 EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY M M H H H M M H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 18Z SUNDAY... BRIEF IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS INTO SUNDAY NIGHT. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR WVZ005-006-013>020-024>040-046-047. OH...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR OHZ087. KY...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR KYZ101>103-105. VA...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR VAZ003-004. && $$ SYNOPSIS...ARJ/MZ NEAR TERM...MZ SHORT TERM...ARJ LONG TERM...JMV AVIATION...MZ
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
637 AM EDT SAT AUG 4 2012 .SYNOPSIS... SCATTERED SHOWERS AND A POSSIBLE THUNDERSTORM WILL OCCUR TODAY AS LOW LEVEL MOISTURE INCREASES OVER THE AREA. MORE ACTIVE WEATHER WILL BEGIN WHEN A STRONG COLD FRONT WILL INTERACT WITH AN UPPER LEVEL DISTURBANCE TO BRING SHOWERS AND THUNDERSTORMS SATURDAY NIGHT INTO SUNDAY. THE FRONT WILL PUSH EAST OF THE AREA SUNDAY NIGHT INTO MONDAY...ALLOWING HIGH PRESSURE AND DRIER AIR TO BUILD INTO THE AREA. NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES CAN THEN BE EXPECTED DURING THE FIRST PART OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... INCREASING SHOWER ACTIVITY IN AMPLE LL MOISTURE AND INCREASING INSTABILITY THROUGH TODAY. HRRR SEEMS TO HAVE A HANDLE ON CURRENT ACTIVITY. COVERAGE NOT EXPECTED TO BE WIDESPREAD...SO HAVE OPTED FOR CHANCE SHRA WITH ISOLD THUNDER THIS MORNING...AND SCT TSTMS THIS AFTERNOON. WITH LACK OF ORGANIZED SURFACE OR UPPER AIR FEATURE...EXPECTATION IS STILL THAT OF UNORGANIZED CONVECTION. WITH LOW LEVEL CLOUDS...HAVE BROUGHT HIGH TEMPERATURES DOWN IN ESPECIALLY THE SOUTHERN HALF OF THE AREA. WITH EXPECTANT CLOUD COVER TODAY...NO HEAT ADVISORY CRITERIA MET WITH SLIGHTLY LOWERED TEMPERATURES. WILL STILL KEEP MENTION IN THE HWO AS VALUES DO APPROACH 100 DEGREES. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... SOME TIMING DIFFERENCES WITH THE MAIN EXPECTATION OF CONVECTION AND SUBSEQUENT FRONTAL PASSAGE...WITH THE GFS A LITTLE FASTER THAN BOTH THE NAM AND ECMWF. HAVE OPTED FOR THE TIMING OF THE LATTER TWO MODELS. EARLY PART OF SAT EVENING CONTINUES FAIRLY DISORGANIZED CONVECTION...WITH THE MORE ORGANIZED DYNAMICALLY DRIVEN ACTIVITY TO BEGIN AFTER 00-06Z TIMEFRAME IN THE ILN AREA. AS THE S/WV DIGS INTO THE UPR MS VALLEY AND APPROACHING WESTERN IN...SOUTHERLY LL FLOW CONTINUES TO PUMP VERY MOIST AIR INTO THE REGION. IN ADDITION TO CONCERN FOR SEVERE WITH THE PRE FRONTAL ACTIVITY...THERE STILL IS POTENTIAL FOR MCS AHEAD OF THIS WITH THE DEVELOPMENT OF A 40 KT+ LLJ (SLIGHTLY WEAKER IN THE ECMWF BUT STILL ENHANCED) AND SIGNIFICANT MOISTURE TRANSPORT. WHILE THERE ISNT STRONG EVIDENCE OF BACK BUILDING STORMS...WARM CLOUD DEPTHS OF NEAR 4500M AND PW VALUES BETWEEN 2.25-2.5 INCHES WILL MAKE FOR POTENTIAL OF VERY HIGH RAINFALL RATES. WITH ENHANCED LL JET AND INCREASING DYNAMICS IN ADDITION TO RESPECTIBLE ML CAPE...POTENTIAL FOR DAMAGING WINDS...WTH POSSIBILITY OF LARGE HAIL. FIRST SHOT OF CONVECTION/POTENTIAL MCS TO EXIT THE AREA BEFORE IN THE 15Z TIMEFRAME...AND THEN STILL SEVERE POTENTIAL AHEAD OF THE FRONT IN THE AFTERNOON DEPENDING ON HOW WORKED OVER THE AIRMASS IS AFTER PASSAGE OF MORNING CONVECTION. HAVE SLOWED DOWN THE TIMING OF THIS CONVECTION TO NOT EXIT THE AREA UNTIL AFTER 00Z...WTH PRECIP LINGERING LONGEST IN THE SE. WITH AMPLE CLOUDS HAVE CONTINUED TO KEEP TEMPS BELOW 90 FOR SUNDAY. FOR SUN NIGHT SKIES TO BEGIN CLEARING IN THE WEST WITH TEMPS DROPPING TO UPR 50S HERE RANGING TO UP 60S SOUTHAST. DRY CONDITIONS AND NEAR NORMAL TEMPERATURES FOR MONDAY AND TUE. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... THE COLD FRONT AND ALL ASSOCIATED PRECIPITATION WILL SHIFT OF TO OUR EAST MONDAY MORNING AS LOW LEVEL RIDGING BUILDS ACROSS THE REGION. SKIES WILL BE MOSTLY CLEAR DURING THE DAY WITH CONTINUED COLD ADVECTION KEEPING TEMPERATURES NEAR...TO JUST BELOW SEASONABLE VALUES DURING THE DAY. THE HIGH PRESSURE AREA WILL REMAIN IN CONTROL OF OUR WEATHER THROUGH TUESDAY NIGHT. THIS WILL KEEP US DRY WITH LIGHT WINDS AND ONLY A FEW PASSING CLOUDS. TEMPERATURES MONDAY NIGHT WILL BE THE COOLEST OF THE WEEK...WITH FORECAST LOWS RANGING FROM THE LOW 60S ACROSS THE SOUTH...TO THE MID 50S ACROSS THE NORTHEAST. BY WEDNESDAY...TEMPERATURES ALOFT BEGIN TO WARM AS A SHORTWAVE OVER THE PLAINS PUSHES PART THEIR VERY WARM AIRMASS TOWARD THE OHIO VALLEY. THIS WILL BRING A REBOUND OF TEMPERATURES BACK TO ABOVE SEASONABLE VALUES FOR THE MIDDLE OF THE WEEK. THE SHORTWAVE WILL THEN SLIDE EASTWARD...BRINGING INCREASING CHANCES FOR PRECIPITATION TOWARD THE END OF THE WEEK. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... SCATTERED CONVECTION WILL BE ONGOING TODAY WITH GENERALLY VFR CONDITIONS OUTSIDE OF THE PASSING SHOWERS. WINDS WILL PICK UP THIS AFTERNOON AND A COLD FRONT WILL CROSS THE REGION AROUND THIS TIME TOMORROW. EXPECT WIND SHIFT AT DAYBREAK TOMORROW WITH MORE PREVALENT THUNDERSTORMS ALONG AND AHEAD OF IT AS THE LOW LEVEL MOISTURE TRANSPORT KICKS IN OVERNIGHT. .OUTLOOK...SHOWERS AND THUNDERSTORMS WILL BECOME MORE LIKELY TONIGHT AND SUNDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...JDR NEAR TERM...JDR SHORT TERM...JDR LONG TERM...LATTO AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
452 AM EDT SAT AUG 4 2012 .SYNOPSIS... SCATTERED SHOWERS AND A POSSIBLE THUNDERSTORM WILL OCCUR TODAY AS LOW LEVEL MOISTURE INCREASES OVER THE AREA. MORE ACTIVE WEATHER WILL BEGIN WHEN A STRONG COLD FRONT WILL INTERACT WITH AN UPPER LEVEL DISTURBANCE TO BRING SHOWERS AND THUNDERSTORMS SATURDAY NIGHT INTO SUNDAY. THE FRONT WILL PUSH EAST OF THE AREA SUNDAY NIGHT INTO MONDAY...ALLOWING HIGH PRESSURE AND DRIER AIR TO BUILD INTO THE AREA. NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES CAN THEN BE EXPECTED DURING THE FIRST PART OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... INCREASING SHOWER ACTIVITY IN AMPLE LL MOISTURE AND INCREASING INSTABILITY THROUGH TODAY. HRRR SEEMS TO HAVE A HANDLE ON CURRENT ACTIVITY. COVERAGE NOT EXPECTED TO BE WIDESPREAD...SO HAVE OPTED FOR CHANCE SHRA WITH ISOLD THUNDER THIS MORNING...AND SCT TSTMS THIS AFTERNOON. WITH LACK OF ORGANIZED SURFACE OR UPPER AIR FEATURE...EXPECTATION IS STILL THAT OF UNORGANIZED CONVECTION. WITH LOW LEVEL CLOUDS...HAVE BROUGHT HIGH TEMPERATURES DOWN IN ESPECIALLY THE SOUTHERN HALF OF THE AREA. WITH EXPECTANT CLOUD COVER TODAY...NO HEAT ADVISORY CRITERIA MET WITH SLIGHTLY LOWERED TEMPERATURES. WILL STILL KEEP MENTION IN THE HWO AS VALUES DO APPROACH 100 DEGREES. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... SOME TIMING DIFFERENCES WITH THE MAIN EXPECTATION OF CONVECTION AND SUBSEQUENT FRONTAL PASSAGE...WITH THE GFS A LITTLE FASTER THAN BOTH THE NAM AND ECMWF. HAVE OPTED FOR THE TIMING OF THE LATTER TWO MODELS. EARLY PART OF SAT EVENING CONTINUES FAIRLY DISORGANIZED CONVECTION...WITH THE MORE ORGANIZED DYNAMICALLY DRIVEN ACTIVITY TO BEGIN AFTER 00-06Z TIMEFRAME IN THE ILN AREA. AS THE S/WV DIGS INTO THE UPR MS VALLEY AND APPROACHING WESTERN IN...SOUTHERLY LL FLOW CONTINUES TO PUMP VERY MOIST AIR INTO THE REGION. IN ADDITION TO CONCERN FOR SEVERE WITH THE PRE FRONTAL ACTIVITY...THERE STILL IS POTENTIAL FOR MCS AHEAD OF THIS WITH THE DEVELOPMENT OF A 40 KT+ LLJ (SLIGHTLY WEAKER IN THE ECMWF BUT STILL ENHANCED) AND SIGNIFICANT MOISTURE TRANSPORT. WHILE THERE ISNT STRONG EVIDENCE OF BACK BUILDING STORMS...WARM CLOUD DEPTHS OF NEAR 4500M AND PW VALUES BETWEEN 2.25-2.5 INCHES WILL MAKE FOR POTENTIAL OF VERY HIGH RAINFALL RATES. WITH ENHANCED LL JET AND INCREASING DYNAMICS IN ADDITION TO RESPECTIBLE ML CAPE...POTENTIAL FOR DAMAGING WINDS...WTH POSSIBILITY OF LARGE HAIL. FIRST SHOT OF CONVECTION/POTENTIAL MCS TO EXIT THE AREA BEFORE IN THE 15Z TIMEFRAME...AND THEN STILL SEVERE POTENTIAL AHEAD OF THE FRONT IN THE AFTERNOON DEPENDING ON HOW WORKED OVER THE AIRMASS IS AFTER PASSAGE OF MORNING CONVECTION. HAVE SLOWED DOWN THE TIMING OF THIS CONVECTION TO NOT EXIT THE AREA UNTIL AFTER 00Z...WTH PRECIP LINGERING LONGEST IN THE SE. WITH AMPLE CLOUDS HAVE CONTINUED TO KEEP TEMPS BELOW 90 FOR SUNDAY. FOR SUN NIGHT SKIES TO BEGIN CLEARING IN THE WEST WITH TEMPS DROPPING TO UPR 50S HERE RANGING TO UP 60S SOUTHAST. DRY CONDITIONS AND NEAR NORMAL TEMPERATURES FOR MONDAY AND TUE. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... THE COLD FRONT AND ALL ASSOCIATED PRECIPITATION WILL SHIFT OF TO OUR EAST MONDAY MORNING AS LOW LEVEL RIDGING BUILDS ACROSS THE REGION. SKIES WILL BE MOSTLY CLEAR DURING THE DAY WITH CONTINUED COLD ADVECTION KEEPING TEMPERATURES NEAR...TO JUST BELOW SEASONABLE VALUES DURING THE DAY. THE HIGH PRESSURE AREA WILL REMAIN IN CONTROL OF OUR WEATHER THROUGH TUESDAY NIGHT. THIS WILL KEEP US DRY WITH LIGHT WINDS AND ONLY A FEW PASSING CLOUDS. TEMPERATURES MONDAY NIGHT WILL BE THE COOLEST OF THE WEEK...WITH FORECAST LOWS RANGING FROM THE LOW 60S ACROSS THE SOUTH...TO THE MID 50S ACROSS THE NORTHEAST. BY WEDNESDAY...TEMPERATURES ALOFT BEGIN TO WARM AS A SHORTWAVE OVER THE PLAINS PUSHES PART THEIR VERY WARM AIRMASS TOWARD THE OHIO VALLEY. THIS WILL BRING A REBOUND OF TEMPERATURES BACK TO ABOVE SEASONABLE VALUES FOR THE MIDDLE OF THE WEEK. THE SHORTWAVE WILL THEN SLIDE EASTWARD...BRINGING INCREASING CHANCES FOR PRECIPITATION TOWARD THE END OF THE WEEK. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... VFR CONDITIONS MAY BE INTERRUPTED BY BR TONIGHT IN A HUMID AIRMASS. SCATTERED CONVECTION TRIGGERED BY WEAK DISTURBANCES IN AN UNSTABLE REGIME WILL AFFECT TAF SITES ON SATURDAY. WINDS WILL BE OUT OF THE SOUTH WITH GUSTS NEAR 20 KNOTS SATURDAY AFTERNOON. .OUTLOOK...SHOWERS AND THUNDERSTORMS ARE LIKELY SATURDAY NIGHT AND SUNDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...JDR NEAR TERM...JDR SHORT TERM...JDR LONG TERM...LATTO AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
420 PM EDT SAT AUG 4 2012 .SYNOPSIS... AN APPROACHING COLD FRONT WILL BRING AN INCREASE IN HUMIDITY AND THE CHANCE OF SHOWERS AND STORMS...SOME OF WHICH MAY BE STRONG TO SEVERE ON SUNDAY...BEFORE DRIER AIR BUILDS IN FOR EARLY NEXT WEEK. OVERALL THE PATTERN FOR EASTERN NORTH AMERICA IS IN TRANSITION WITH THE EXPECTED DEVELOPMENT OF A BROAD TROUGH OVER THE NEXT 4 TO 8 DAYS. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... SHOWERS AND STORMS WILL CONTINUE TO POP UP INTO THE EVENING IN THE MOIST SOUTHWESTERLY FLOW. MESO ANAL SHOWS CAPES TOPPING 4000J WITH INHIBITION DIMINISHING RAPIDLY. HAVE TRIED TO FASHION THE NEAR TERM POPS TO CURRENT RADAR TRENDS AND HRRR OUTPUT OVER THE NEXT SEVERAL HOURS. THESE KEEP SHOWERS AND STORMS INTO THE EVENING BEFORE QUIETING DOWN AFTER 03Z. AIRMASS IS VERY SOUPY WITH PWATS OVER 1.5" FOR MUCH OF THE FCST AREA. CAN EASILY SEE 1-2 INCH PER HOUR RAINFALL RATES IN SOME OF THE MORE ROBUST STORMS...ALONG WITH LOCALLY GUSTY POSSIBLY EVEN DAMAGING WINDS. ACTIVITY SHOULD DIMINISH TOWARD MIDNIGHT WITH PATCHY FOG AHEAD OF THE FRONT IS AGAIN A POSSIBILITY LATER AT NIGHT. IT WILL BE QUITE MUGGY WITH LOWS A FEW DEG EITHER SIDE OF 70 EVERYWHERE. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... FRONTAL SYSTEM TO OUR WEST AND THE RIDGE OVER THE ATLANTIC WILL SEND A DEEP PLUME OF MOISTURE WITH 2-3 SIGMA ABOVE NORMAL PW INTO OUR REGION. HIGH PW VALUES ARE LIKELY IN THE STRONG FLOW AHEAD OF THE COLD FRONT. WHILE THE STRONGEST FLOW WILL LIKELY LIFT NE OF OUR AREA...THE FLOW WILL BE RATHER STRONG FOR EARLY AUG. CAPE VALUES ARE GOOD FOR SEVERE WEATHER BUT NOT OVERLY IMPRESSIVE. BUT OVER 20KTS OF 1KM SHEAR WITH 1200 TO 1800JKG-1 IMPLIES DEEP UPDRAFTS AND GOOD SHEAR. THIS SHOULD FAVOR THE DEVELOPMENT...MAINLY FROM MID AFTERNOON INTO EVENING OF STRONG TO POTENTIAL SEVERE THUNDERSTORMS...FAVORING MORE LINEAR SYSTEMS WITH POTENTIAL BOW DEVELOPMENT. MOST GUIDANCE SHOWS STRONG LOW-LEVEL SHEAR WHICH WILL REQUIRE MONITORING. MULTI-CELLULAR DAY LIKELY WITH BOWING SEGMENTS HIGH PROBABILITY THINKING AT THIS TIME. MOISTURE FLUX...OFTEN ALIGNS WELL WITH OUR BETTER SEVERE EVENTS PEAKS 1800 UTC SUNDAY TO ABOUT 0000 UTC MONDAY. GOOD BET STRONG STORMS FROM ABOUT 2 PM SUNDAY UNTIL 10 PM IN EAST. && .LONG TERM /MONDAY THROUGH SATURDAY/... BY MONDAY MORNING...COLD FRONT WILL BE JUST SE OF CWA. WILL TAKE SOME TIME TO CLEAR OUT RESIDUAL MOISTURE IN SOUTHEAST. BUT WITH WESTERLY WINDS...DRIER AIR WILL EVENTUALLY WORK INTO THE BOUNDARY LAYER IN THE SE. PW FALLS BELOW NORMAL STATE WIDE MONDAY. CENTER OF SFC HIGH SETTLES OVER PA MON NIGHT/TUE KEEPING FORECAST DRY. WEAK WAVE OVER SE U.S. SLIDES UP THE COAST FOR WED/THU...NUDGING MOISTURE BACK INTO CWA. SO INTRODUCED SLIGHT CHANCE FOR A TSTM WED/THU AS HUMIDITY BEGINS TO INCREASE. MORE POTENT TROUGH APPROACHES IN NW FLOW FOR THU NIGHT-FRI NIGHT. MODELS HANDLING THIS FEATURE WELL...THOUGH GFS TRIES TO LIFT TROUGH NORTHWARD. EITHER WAY...CHANCE OF SHOWERS/TSTMS FITS THE BILL BEFORE A MAINLY DRY WEEKEND. TEMPERATURES WILL BE NEAR NORMAL TO START THE WEEK...THEN SLOWLY RISE BACK ABOVE NORMAL FOR MIDWEEK. AS HUMIDITY INCREASES LATE WEEK AHEAD OF APPROACHING TROUGH...TEMPS AGAIN GET A BIT MUGGY - EVEN THOUGH THEY REMAIN JUST A FEW DEGREES ABOVE NORMAL. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... LOCALIZED REDUCED CONDITIONS CAN BE EXPECTED INTO THE EVENING AS SHOWERS AND THUNDERSTORMS CONTINUE TO POP UP UNDER DAYTIME HEATING. STORM OVER MDT HAS CAUSED LIFR IN THE HEAVY RAIN...AND OTHER TERMINALS CAN EXPECT SIMILAR CONDITIONS WHERE DIRECT HITS FROM STORMS TAKE PLACE. OUTLOOK... .SUN...A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS...ESPECIALLY SUNDAY PM AS A COLD FRONT MOVES THROUGH. .MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR. .TUES-THU...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...RXR LONG TERM...RXR AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
159 PM EDT SAT AUG 4 2012 .SYNOPSIS... AN APPROACHING COLD FRONT WILL BRING AN INCREASE IN HUMIDITY AND THE CHANCE OF SHOWERS AND STORMS THROUGH SUNDAY...BEFORE DRIER AIR BUILDS IN FOR EARLY NEXT WEEK. OVERALL THE PATTERN FOR EASTERN NORTH AMERICA IS IN TRANSITION WITH THE EXPECTED DEVELOPMENT OF A BROAD TROUGH OVER THE NEXT 4 TO 8 DAYS. && .NEAR TERM /THROUGH TONIGHT/... SHOWERS AND STORMS WILL CONTINUE TO POP UP INTO THE EVENING IN THE MOIST SOUTHWESTERLY FLOW. MESO ANAL SHOWS CAPES TOPPING 4000J WITH INHIBITION DIMINISHING RAPIDLY. HAVE TRIED TO FASHION THE NEAR TERM POPS TO CURRENT RADAR TRENDS AND HRRR OUTPUT OVER THE NEXT SEVERAL HOURS. THESE KEEP SHOWERS AND STORMS INTO THE EVENING BEFORE QUIETING DOWN AFTER 03Z. AIRMASS IS VERY SOUPY WITH PWATS OVER 1.5" FOR MUCH OF THE FCST AREA. CAN EASILY SEE 1-2 INCH PER HOUR RAINFALL RATES IN SOME OF THE MORE ROBUST STORMS...ALONG WITH LOCALLY GUSTY POSSIBLY EVEN DAMAGING WINDS. ACTIVITY SHOULD DIMINISH TOWARD MIDNIGHT WITH PATCHY FOG AHEAD OF THE FRONT IS AGAIN A POSSIBILITY LATER AT NIGHT. IT WILL BE QUITE MUGGY WITH LOWS A FEW DEG EITHER SIDE OF 70 EVERYWHERE. && .SHORT TERM /SUNDAY/... SUNDAY THE FRONTAL SYSTEM TO OUR WEST AND THE RIDGE OVER THE ATLANTIC WILL SEND A DEEP PLUME OF MOISTURE WITH 2-3 SIGMA ABOVE NORMAL PW INTO OUR REGION. HIGH PW VALUES ARE LIKELY IN THE STRONG FLOW AHEAD OF THE COLD FRONT. WHILE THE STRONGEST FLOW WILL LIKELY LIFT NE OF OUR AREA...THE FLOW WILL BE RATHER STRONG FOR EARLY AUG. CAPE VALUES ARE GOOD FOR SEVERE WEATHER BUT NOT OVERLY IMPRESSIVE. BUT OVER 20KTS OF 1KM SHEAR WITH 1200 TO 1800JKG-1 IMPLIES DEEP UPDRAFTS AND GOOD SHEAR. THIS SHOULD FAVOR THE DEVELOPMENT...MAINLY IN THE AFTERNOON INTO EVENING OF STRONG TO POTENTIAL SEVERE THUNDERSTORMS. FAVORING MORE LINEAR SYSTEMS WITH POTENTIAL BOW DEVELOPMENT. MOST GUIDANCE SHOWS STRONG LOW-LEVEL SHEAR WHICH WILL REQUIRE MONITORING. MULTI-CELLULAR DAY LIKELY WITH BOWING SEGMENTS HIGH PROBABILITY THINKING AT THIS TIME. MOISTURE FLUX...OFTEN ALIGNS WELL WITH OUR BETTER SEVERE EVENTS PEAKS 1800 UTC SUNDAY TO ABOUT 0000 UTC MONDAY. GOOD BET STRONG STORMS FROM ABOUT 2 PM SUNDAY UNTIL 8 PM IN EAST. UPPED POPS IN AFTERNOON INTO 80S BUT KEPT CLOSE TO NEIGHBORS FOR COLLABORATION. PROBABLY NEED 90S IN THERE! && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... GEFS/SREF/GFS ALL SLOW TO CLEAR OUT THE RESIDUAL MOISTURE MONDAY MORNING IN SOUTHEAST. BUT WINDS ARE WESTERLY. MAY TAKE UNTIL MID- MORNING MONDAY TO GET THE DRY AIR INTO THE BOUNDARY LAYER. BUT PW FALLS BELOW NORMAL STATE WIDE MONDAY. KEPT POPS LOWER THAN GUIDANCE THROUGH WEDNESDAY AND GOT RID OF SHOWERS AS THE PW VALUES ARE NEAR TO SLIGHTLY BELOW NORMAL. PW IS NEAR NORMAL BY THURSDAY INTO SATURDAY SO KEPT CLOSE TO GUIDANCE. TEMPERATURE-WISE...850 HPA TEMPERATURES MAINLY NEAR NORMAL. SLIGHT SURGE OF CLOSE TO 1 SIGMA ABOVE NORMAL WEDNESDAY AHEAD OF WHAT MODELS IMPLY WOULD BE A SECONDARY COLD FRONT TAKING THE EDGE OF A BIT MORE THURSDAY INTO FRIDAY. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... LOCALIZED REDUCED CONDITIONS CAN BE EXPECTED INTO THE EVENING AS SHOWERS AND THUNDERSTORMS CONTINUE TO POP UP UNDER DAYTIME HEATING. STORM OVER MDT HAS CAUSED LIFR IN THE HEAVY RAIN...AND OTHER TERMINALS CAN EXPECT SIMILAR CONDITIONS WHERE DIRECT HITS FROM STORMS TAKE PLACE. OUTLOOK... .SUN...A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS...ESPECIALLY SUNDAY PM AS A COLD FRONT MOVES THROUGH. .MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR. .TUES-THU...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LAMBERT/MARTIN LONG TERM...GRUMM/MARTIN AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1053 AM EDT SAT AUG 4 2012 .SYNOPSIS... AN APPROACHING COLD FRONT WILL BRING AN INCREASE IN HUMIDITY AND THE CHANCE OF SHOWERS AND STORMS THROUGH SUNDAY...BEFORE DRIER AIR BUILDS IN FOR EARLY NEXT WEEK. OVERALL THE PATTERN FOR EASTERN NORTH AMERICA IS IN TRANSITION WITH THE EXPECTED DEVELOPMENT OF A BROAD TROUGH OVER THE NEXT 4 TO 8 DAYS. && .NEAR TERM /THROUGH TONIGHT/... MOIST SOUTHWESTERLY FLOW WILL CONTINUE TO INCREASE AHEAD OF A COLD FRONT ENTERING THE GR LAKES. THIS WILL PROVIDE INCREASING CHANCES FOR SHOWERS/STORMS...ESPECIALLY THIS AFTERNOON AND EVENING. MUCH OF THE MORNING AND POSSIBLY EVEN INTO THE EARLY AFTERNOON HOURS SHOULD STAY PARTLY TO MOSTLY SUNNY AND DRY BEFORE WE REACH CONVECTIVE TEMPS AND START TO COOK UP SCATTERED SHOWERS AND STORMS. SREF POPS FOR LATER THIS AFTERNOON AND EVENING RANGE FROM CHANCE OVER THE NORTH TO CATEGORICAL OVER THE SOUTH...PROBABLY TYPICALLY OVERDONE BY THE SREF. CURRENT HRRR SHOWING PRECIPITATION FORMING OVER THE LAUREL HIGHLANDS BY 18Z. THE SREF AND GEFS HAVE INCREASED PWAT ANOMALIES OVER THE AREA. COUPLE THIS WITH TEMPERATURES IN THE UPPER 80S AND LOWER 90S...AND DECENT SOUTHEASTERLY FLOW...EXPECT DIURNAL CONVECTION THIS AFTERNOON AND THROUGH THE FIRST HALF OF THE EVENING. MODELS SOW IT SPREADING ACROSS CENTRAL PA BEFORE MOVING EASTWARD. HAVE INCREASED POPS ACCORDINGLY. THESE SHOWERS AND STORMS SHOULD BE MORE DIURNALLY DRIVEN THAN LARGER SYNOPTIC FORCING...HOWEVER A 500MB SHORTWAVE COULD ALLOW FOR A STRONG ENOUGH PV ANOMALY TO CONTINUE SHOWERS WELL INTO THE EVENING OVER THE SOUTHEAST. ANY PRECIP SHOULD BE DONE BY 06-09Z TONIGHT. PATCHY FOG AHEAD OF THE FRONT IS AGAIN A POSSIBILITY OVERNIGHT. && .SHORT TERM /SUNDAY/... SUNDAY THE FRONTAL SYSTEM TO OUR WEST AND THE RIDGE OVER THE ATLANTIC WILL SEND A DEEP PLUME OF MOISTURE WITH 2-3 SIGMA ABOVE NORMAL PW INTO OUR REGION. HIGH PW VALUES ARE LIKELY IN THE STRONG FLOW AHEAD OF THE COLD FRONT. WHILE THE STRONGEST FLOW WILL LIKELY LIFT NE OF OUR AREA...THE FLOW WILL BE RATHER STRONG FOR EARLY AUG. CAPE VALUES ARE GOOD FOR SEVERE WEATHER BUT NOT OVERLY IMPRESSIVE. BUT OVER 20KTS OF 1KM SHEAR WITH 1200 TO 1800JKG-1 IMPLIES DEEP UPDRAFTS AND GOOD SHEAR. THIS SHOULD FAVOR THE DEVELOPMENT...MAINLY IN THE AFTERNOON INTO EVENING OF STRONG TO POTENTIAL SEVERE THUNDERSTORMS. FAVORING MORE LINEAR SYSTEMS WITH POTENTIAL BOW DEVELOPMENT. MOST GUIDANCE SHOWS STRONG LOW-LEVEL SHEAR WHICH WILL REQUIRE MONITORING. MULTI-CELLULAR DAY LIKELY WITH BOWING SEGMENTS HIGH PROBABILITY THINKING AT THIS TIME. MOISTURE FLUX...OFTEN ALIGNS WELL WITH OUR BETTER SEVERE EVENTS PEAKS 1800 UTC SUNDAY TO ABOUT 0000 UTC MONDAY. GOOD BET STRONG STORMS FROM ABOUT 2 PM SUNDAY UNTIL 8 PM IN EAST. UPPED POPS IN AFTERNOON INTO 80S BUT KEPT CLOSE TO NEIGHBORS FOR COLLABORATION. PROBABLY NEED 90S IN THERE! && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... GEFS/SREF/GFS ALL SLOW TO CLEAR OUT THE RESIDUAL MOISTURE MONDAY MORNING IN SOUTHEAST. BUT WINDS ARE WESTERLY. MAY TAKE UNTIL MID- MORNING MONDAY TO GET THE DRY AIR INTO THE BOUNDARY LAYER. BUT PW FALLS BELOW NORMAL STATE WIDE MONDAY. KEPT POPS LOWER THAN GUIDANCE THROUGH WEDNESDAY AND GOT RID OF SHOWERS AS THE PW VALUES ARE NEAR TO SLIGHTLY BELOW NORMAL. PW IS NEAR NORMAL BY THURSDAY INTO SATURDAY SO KEPT CLOSE TO GUIDANCE. TEMPERATURE-WISE...850 HPA TEMPERATURES MAINLY NEAR NORMAL. SLIGHT SURGE OF CLOSE TO 1 SIGMA ABOVE NORMAL WEDNESDAY AHEAD OF WHAT MODELS IMPLY WOULD BE A SECONDARY COLD FRONT TAKING THE EDGE OF A BIT MORE THURSDAY INTO FRIDAY. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... CONDITIONS HAVE IMPROVED TO HIGH MVFR/LOW VFR AS LAST OF THE HAZE CONTINUES TO THIN OUT. LOCALIZED REDUCED CONDITIONS CAN BE EXPECTED LATER TODAY IN AND AROUND AN THUNDERSTORMS THAT ARE EXPECTED TO DEVELOP THIS AFTERNOON AND EARLY EVENING...FROM ABOUT 22Z THROUGH 03Z TONIGHT. OUTLOOK... .SUN...A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS...ESPECIALLY SUNDAY PM AS A COLD FRONT MOVES THROUGH. .MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR. .TUES-WED...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/CERU/MARTIN NEAR TERM...LA CORTE/CERU/MARTIN SHORT TERM...LAMBERT/MARTIN LONG TERM...GRUMM/MARTIN AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
852 AM EDT SAT AUG 4 2012 .SYNOPSIS... AN APPROACHING COLD FRONT WILL BRING AN INCREASE IN HUMIDITY AND THE CHANCE OF SHOWERS AND STORMS THROUGH SUNDAY...BEFORE DRIER AIR BUILDS IN FOR EARLY NEXT WEEK. OVERALL THE PATTERN FOR EASTERN NORTH AMERICA IS IN TRANSITION WITH THE EXPECTED DEVELOPMENT OF A BROAD TROUGH OVER THE NEXT 4 TO 8 DAYS. && .NEAR TERM /THROUGH TONIGHT/... STILL SOME PATCHY LOW CLOUDS AND MAINLY THIN FOG THAT WILL BURN OFF SMARTLY NOW THAT THE SUN IS UP. MOIST SOUTHWESTERLY FLOW WILL CONTINUE TO INCREASE AHEAD OF A COLD FRONT ENTERING THE GR LAKES. THIS WILL PROVIDE INCREASING CHANCES FOR SHOWERS/STORMS...ESPECIALLY THIA AFTERNOON AND EVENING. MUCH OF THE MORNING AND POSSIBLY EVEN INTO THE EARLY AFTERNOON HOURS SHOULD STAY PARTLY TO MOSTLY SUNNY AND DRY BEFORE WE REACH CONVECTIVE TEMPS AND START TO COOK UP SCATTERED SHOWERS AND STORMS. SREF POPS FOR LATER THIS AFTERNOON AND EVENING RANGE FROM CHANCE OVER THE NORTH TO CATEGORICAL OVER THE SOUTH...PROBABLY TYPICALLY OVERDONE BY THE SREF. CURRENT HRRR SHOWING PRECIPITATION FORMING OVER THE LAUREL HIGHLANDS BY 18Z. THE SREF AND GEFS HAVE INCREASED PWAT ANOMALIES OVER THE AREA. COUPLE THIS WITH TEMPERATURES IN THE UPPER 80S AND LOWER 90S...AND DECENT SOUTHEASTERLY FLOW...EXPECT DIURNAL CONVECTION THIS AFTERNOON AND THROUGH THE FIRST HALF OF THE EVENING. MODELS SOW IT SPREADING ACROSS CENTRAL PA BEFORE MOVING EASTWARD. HAVE INCREASED POPS ACCORDINGLY. THESE SHOWERS AND STORMS SHOULD BE MORE DIURNALLY DRIVEN THAN LARGER SYNOPTIC FORCING...HOWEVER A 500MB SHORTWAVE COULD ALLOW FOR A STRONG ENOUGH PV ANOMALY TO CONTINUE SHOWERS WELL INTO THE EVENING OVER THE SOUTHEAST. ANY PRECIP SHOULD BE DONE BY 06-09Z TONIGHT. PATCHY FOG AHEAD OF THE FRONT IS AGAIN A POSSIBILITY OVERNIGHT. && .SHORT TERM /SUNDAY/... SUNDAY THE FRONTAL SYSTEM TO OUR WEST AND THE RIDGE OVER THE ATLANTIC WILL SEND A DEEP PLUME OF MOISTURE WITH 2-3 SIGMA ABOVE NORMAL PW INTO OUR REGION. HIGH PW VALUES ARE LIKELY IN THE STRONG FLOW AHEAD OF THE COLD FRONT. WHILE THE STRONGEST FLOW WILL LIKELY LIFT NE OF OUR AREA...THE FLOW WILL BE RATHER STRONG FOR EARLY AUG. CAPE VALUES ARE GOOD FOR SEVERE WEATHER BUT NOT OVERLY IMPRESSIVE. BUT OVER 20KTS OF 1KM SHEAR WITH 1200 TO 1800JKG-1 IMPLIES DEEP UPDRAFTS AND GOOD SHEAR. THIS SHOULD FAVOR THE DEVELOPMENT...MAINLY IN THE AFTERNOON INTO EVENING OF STRONG TO POTENTIAL SEVERE THUNDERSTORMS. FAVORING MORE LINEAR SYSTEMS WITH POTENTIAL BOW DEVELOPMENT. MOST GUIDANCE SHOWS STRONG LOW-LEVEL SHEAR WHICH WILL REQUIRE MONITORING. MULTI-CELLULAR DAY LIKELY WITH BOWING SEGMENTS HIGH PROBABILITY THINKING AT THIS TIME. MOISTURE FLUX...OFTEN ALIGNS WELL WITH OUR BETTER SEVERE EVENTS PEAKS 1800 UTC SUNDAY TO ABOUT 0000 UTC MONDAY. GOOD BET STRONG STORMS FROM ABOUT 2 PM SUNDAY UNTIL 8 PM IN EAST. UPPED POPS IN AFTERNOON INTO 80S BUT KEPT CLOSE TO NEIGHBORS FOR COLLABORATION. PROBABLY NEED 90S IN THERE! && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... GEFS/SREF/GFS ALL SLOW TO CLEAR OUT THE RESIDUAL MOISTURE MONDAY MORNING IN SOUTHEAST. BUT WINDS ARE WESTERLY. MAY TAKE UNTIL MID- MORNING MONDAY TO GET THE DRY AIR INTO THE BOUNDARY LAYER. BUT PW FALLS BELOW NORMAL STATE WIDE MONDAY. KEPT POPS LOWER THAN GUIDANCE THROUGH WEDNESDAY AND GOT RID OF SHOWERS AS THE PW VALUES ARE NEAR TO SLIGHTLY BELOW NORMAL. PW IS NEAR NORMAL BY THURSDAY INTO SATURDAY SO KEPT CLOSE TO GUIDANCE. TEMPERATURE-WISE...850 HPA TEMPERATURES MAINLY NEAR NORMAL. SLIGHT SURGE OF CLOSE TO 1 SIGMA ABOVE NORMAL WEDNESDAY AHEAD OF WHAT MODELS IMPLY WOULD BE A SECONDARY COLD FRONT TAKING THE EDGE OF A BIT MORE THURSDAY INTO FRIDAY. && .AVIATION /13Z SATURDAY THROUGH WEDNESDAY/... PATCHY IFR AND LOWER CIGS AND VSBYS WILL CONTINUE THROUGH 14Z THIS MORNING. LOW STRATO CU WILL SPREAD ACROSS THE LOWER SUSQ...AND OVER THE NW MTNS. THE CENTRAL PA REGION HAS SEEN THE DEVELOPMENT OF SOME MID LEVEL CLOUDS. LOW STRATOCU COULD STILL SPREAD OUT THROUGH 15Z...BEFORE IT AND THE PATCHY FOG DISSIPATES. IFR IS POSSIBLE IN AND AROUND TSRA THIS AFTERNOON AND EARLY EVENING DUE TO A STRONGER CHANCE FOR CONVECTION...ESPECIALLY JST...AOO AND ALONG THE LOWER SUSQ TAF SITES FROM 22Z THROUGH 03Z TONIGHT. OUTLOOK... .SAT-SUN...A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS... ESPECIALLY SUNDAY AS A COLD FRONT MOVES THROUGH. .MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR. .TUES...NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/CERU/MARTIN NEAR TERM...LA CORTE/CERU/MARTIN SHORT TERM...LAMBERT/MARTIN LONG TERM...GRUMM/MARTIN AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
840 PM CDT SUN AUG 5 2012 .UPDATE... CONVECTION ACROSS OUR NW COUNTIES JUST AHEAD OF A SOUTHWARD MOVING SHORTWAVE. FRONTAL BOUNDARY STILL WELL TO THE NORTH ALONG THE OHIO RIVER. HRRR AND OTHER MODELS CONTINUE TO SHY AWAY FROM DEVELOPMENT BEHIND THE CURRENT CONVECTION. FURTHERMORE...NUMERICAL POPS BETWEEN 06Z AND 12Z ARE NOT ALL THAT IMPRESSIVE. THUS...FOR THE FCST...WILL BE LOWERING POPS ACROSS THE PLATEAU AND FAR WESTERN AREAS AS WELL(BEFORE 06Z). OTW...POPS IN THE SLT CHANCE TO CHANCE CATEGORY WILL RESUME AFT 06Z AS THE BOUNDARY WITH THE DRIER AIR WILL REMAIN NORTH OF THE MID STATE. AS FOR THE FOG POTENTIAL ACROSS THE WEST...DEWPOINT DEPRESSIONS ARE RATHER LOW AND NUMERICAL GUIDANCE STILL CARRYING LOW VSBY LEVELS AT CKV. WILL THEREFORE KEEP THE FOG GOING. UPDATE OUT SHORTLY. && .PREV DISCUSSION... /ISSUED 753 PM CDT SUN AUG 5 2012/ UPDATE...FOR 00Z TAFS. AVIATION... ANOTHER TOUGH FORECAST WITH QUESTION OF HOW FAR SOUTH COLD FRONT JUST NORTHWEST WILL SINK. AIRMASS REMAINS PLENTY MOIST AND UNSTABLE AND UPSTREAM CONVECTION SHOULD HOLD TOGETHER AND POSSIBLY AFFECT CKV/BNA THIS EVENING. STORMS ALSO EXPECTED TO AFFECT CSV OVERNIGHT. VSBYS ALSO LIKELY REDUCED BY FOG LATER TONIGHT. VFR CONDITIONS MOSTLY MONDAY AS DEEP MOISTURE MOVES SOUTH BUT CSV EXPECTED TO HAVE BRIEF DECREASE IN CEILING/VSBY FROM PASSING STORMS. PREV DISCUSSION... /ISSUED 627 PM CDT SUN AUG 5 2012/ UPDATE... FRONTAL BOUNDARY STILL A GOOD DISTANCE TO OUR NORTHWEST AND CURRENTLY EXTENDS ROUGHLY ALONG THE OHIO RIVER. 3HR PRESSURE CHANGE SHOWS AN INCREASE IN NEGATIVE VALUES ACROSS THE MID STATE COMPARED TO POINTS NW. THUS...THE FRONT IS SAGGING OUR WAY BUT WILL MOST LIKELY REACH NO FURTHER SOUTH THAN OUR NW COUNTIES LATE TONIGHT. OTW...EXAMINATION OF THE LATEST HRRR DATA SUGGESTS THAT THE ONGOING SCT CONVECTION SHOULD BEGIN TO FILL IN A BIT. SEEING SOME GOOD INFLOW ENERGY AT THE 10 KFT LEVEL BUT SO FAR...STORM INTENSITIES ARE NOT MUCH TO SPEAK OF. SHORTWAVE AND FRONTAL BOUNDARY SHOULD BE APPROACHING OUR NORTHWESTERN AREAS BY 12Z. THUS... SEE NO REASON TO UPDATE AT THIS POINT AND LOWER POPS AS THE LATEST RADAR TRENDS ARE SHOWING AN INCREASE IN COVERAGE ACROSS OUR NORTHWEST. THUS...WILL KEEP FORECAST GOING...AS IS...FOR NOW. PREV DISCUSSION... /ISSUED 259 PM CDT SUN AUG 5 2012/ DISCUSSION...CURRENTLY ACROSS THE MID STATE...A NE-SW BAND OF THUNDERSTORMS WAS MOVING SLOWLY EASTWARD ONTO THE CUMBERLAND PLATEAU. THIS BAND OF STORMS HAS DUMPED SOME HEAVY RAINFALL...ESPECIALLY NE OF BNA FROM GALLATIN TO HARTSVILLE AND GAINESBORO. TEMPERATURES VARIED CONSIDERABLY ACROSS THE AREA. LOCATIONS THAT EXPERIENCED STORMS WERE WELL BELOW EXPECTED HIGHS...WITH LATEST READINGS IN THE UPPER 70S TO LOWER 80S. THE DRIER LOCATIONS OVER THE FAR SOUTHEAST AND NORTHWEST HAD REACHED EXPECTED HIGHS...INCLUDING LOWER 90S AROUND CLARKSVILLE. WE HAVE LOW CONFIDENCE WITH SOME DETAILS DURING THE FIRST PERIOD OF THIS FORECAST. SHORT RANGE MODELS NEVER PICKED UP WELL ON THE BAND OF THUNDERSTORMS OVER THE AREA TODAY. ALSO...SHORT RANGE MODELS SHOWED CONSIDERABLE DEVELOPMENT AHEAD OF THE COLD FRONT...STILL LOCATED NW OF OUR AREA. SO FAR THERE HAS BEEN VERY LITTLE DEVELOPMENT AHEAD OF THE FRONT. OUR EARLIER THINKING WAS THAT STORMS WOULD INCREASE AHEAD OF THE FRONT WITH WIDESPREAD AND HEAVY THUNDERSTORMS CROSSING MID TN THIS EVENING. NOW IT APPEARS WE WILL HAVE TO BACK OFF. WE DO STILL EXPECT SOME ACTIVITY WITH THE FRONT...SINCE IT WILL BE RUNNING INTO MOIST AND UNSTABLE AIR WITH NEAR 2000 J/KG CAPE OVER OUR NW COUNTIES. BUT THE ACTIVITY WILL PROBABLY BE SCATTERED (AROUND 50 PERCENT POP)...RATHER THAN WIDESPREAD (80 PERCENT) AS WE HAD THOUGHT. ANY STORMS LATE TODAY INTO THIS EVENING COULD PRODUCE VERY HEAVY DOWNPOURS. PRECIPITABLE WATER VALUES REMAIN OVER 2 INCHES AND STORM MOTION WILL BE ONLY AROUND 10KT. THERE CONTINUES TO A SMALL THREAT FOR SEVERE STORMS WITH DAMAGING WIND GUSTS. IT APPEARS OUR NW COUNTIES WILL HAVE THE GREATEST POTENTIAL...BUT ANY SEVERE WOULD BE RATHER ISOLATED. LATER TONIGHT INTO MONDAY...THE FRONT WILL SLOW DOWN...THEN STALL JUST SE OF OUR AREA. MODELS SHOW A LINGERING INVERTED TROUGH OVER MID TN WITH A GRADIENT OF MOISTURE FROM SE TO NW. WE WILL KEEP A CHANCE FOR SHOWERS OR STORMS IN THE FORECAST FOR MONDAY...WITH THE HIGHER POPS IN THE SE AND VERY LOW POPS IN OUR NW COUNTIES. FOR TUESDAY THROUGH THURSDAY...OUR WEATHER WILL BE WARM AND HUMID. LOW WILL BE GENERALLY IN THE UPPER 60S TO AROUND 70 WITH HIGHS ABOUT 90. ISOLATED TO SCATTERED STORMS WILL REMAIN IN THE FORECAST...MAINLY PLATEAU WHERE PERSISTENT WEAK TROUGHING AND MOISTURE CONVERGENCE IS INDICATED. BY FRIDAY...A STRONG TROUGH WILL BE LOCATED OVER THE UPPER MIDWEST. THIS WAVE WILL DIG SE HELPING PULL A COLD FRONT THROUGH THE AREA. SCATTERED THUNDERSTORMS WILL DEVELOP AHEAD OF THE FRONT LATE THURSDAY INTO FRIDAY. DRY WX WITH NEAR NORMAL TEMPS WILL FOLLOW THE FRONT...WITH LOWS IN THE 60S...HIGHS IN THE MID 80S AND MORE PLEASANT HUMIDITY LEVELS. 13 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
753 PM CDT SUN AUG 5 2012 .UPDATE...FOR 00Z TAFS. && .AVIATION... ANOTHER TOUGH FORECAST WITH QUESTION OF HOW FAR SOUTH COLD FRONT JUST NORTHWEST WILL SINK. AIRMASS REMAINS PLENTY MOIST AND UNSTABLE AND UPSTREAM CONVECTION SHOULD HOLD TOGETHER AND POSSIBLY AFFECT CKV/BNA THIS EVENING. STORMS ALSO EXPECTED TO AFFECT CSV OVERNIGHT. VSBYS ALSO LIKELY REDUCED BY FOG LATER TONIGHT. VFR CONDITIONS MOSTLY MONDAY AS DEEP MOISTURE MOVES SOUTH BUT CSV EXPECTED TO HAVE BRIEF DECREASE IN CEILING/VSBY FROM PASSING STORMS. && .PREV DISCUSSION... /ISSUED 627 PM CDT SUN AUG 5 2012/ UPDATE... FRONTAL BOUNDARY STILL A GOOD DISTANCE TO OUR NORTHWEST AND CURRENTLY EXTENDS ROUGHLY ALONG THE OHIO RIVER. 3HR PRESSURE CHANGE SHOWS AN INCREASE IN NEGATIVE VALUES ACROSS THE MID STATE COMPARED TO POINTS NW. THUS...THE FRONT IS SAGGING OUR WAY BUT WILL MOST LIKELY REACH NO FURTHER SOUTH THAN OUR NW COUNTIES LATE TONIGHT. OTW...EXAMINATION OF THE LATEST HRRR DATA SUGGESTS THAT THE ONGOING SCT CONVECTION SHOULD BEGIN TO FILL IN A BIT. SEEING SOME GOOD INFLOW ENERGY AT THE 10 KFT LEVEL BUT SO FAR...STORM INTENSITIES ARE NOT MUCH TO SPEAK OF. SHORTWAVE AND FRONTAL BOUNDARY SHOULD BE APPROACHING OUR NORTHWESTERN AREAS BY 12Z. THUS... SEE NO REASON TO UPDATE AT THIS POINT AND LOWER POPS AS THE LATEST RADAR TRENDS ARE SHOWING AN INCREASE IN COVERAGE ACROSS OUR NORTHWEST. THUS...WILL KEEP FORECAST GOING...AS IS...FOR NOW. PREV DISCUSSION... /ISSUED 259 PM CDT SUN AUG 5 2012/ DISCUSSION...CURRENTLY ACROSS THE MID STATE...A NE-SW BAND OF THUNDERSTORMS WAS MOVING SLOWLY EASTWARD ONTO THE CUMBERLAND PLATEAU. THIS BAND OF STORMS HAS DUMPED SOME HEAVY RAINFALL...ESPECIALLY NE OF BNA FROM GALLATIN TO HARTSVILLE AND GAINESBORO. TEMPERATURES VARIED CONSIDERABLY ACROSS THE AREA. LOCATIONS THAT EXPERIENCED STORMS WERE WELL BELOW EXPECTED HIGHS...WITH LATEST READINGS IN THE UPPER 70S TO LOWER 80S. THE DRIER LOCATIONS OVER THE FAR SOUTHEAST AND NORTHWEST HAD REACHED EXPECTED HIGHS...INCLUDING LOWER 90S AROUND CLARKSVILLE. WE HAVE LOW CONFIDENCE WITH SOME DETAILS DURING THE FIRST PERIOD OF THIS FORECAST. SHORT RANGE MODELS NEVER PICKED UP WELL ON THE BAND OF THUNDERSTORMS OVER THE AREA TODAY. ALSO...SHORT RANGE MODELS SHOWED CONSIDERABLE DEVELOPMENT AHEAD OF THE COLD FRONT...STILL LOCATED NW OF OUR AREA. SO FAR THERE HAS BEEN VERY LITTLE DEVELOPMENT AHEAD OF THE FRONT. OUR EARLIER THINKING WAS THAT STORMS WOULD INCREASE AHEAD OF THE FRONT WITH WIDESPREAD AND HEAVY THUNDERSTORMS CROSSING MID TN THIS EVENING. NOW IT APPEARS WE WILL HAVE TO BACK OFF. WE DO STILL EXPECT SOME ACTIVITY WITH THE FRONT...SINCE IT WILL BE RUNNING INTO MOIST AND UNSTABLE AIR WITH NEAR 2000 J/KG CAPE OVER OUR NW COUNTIES. BUT THE ACTIVITY WILL PROBABLY BE SCATTERED (AROUND 50 PERCENT POP)...RATHER THAN WIDESPREAD (80 PERCENT) AS WE HAD THOUGHT. ANY STORMS LATE TODAY INTO THIS EVENING COULD PRODUCE VERY HEAVY DOWNPOURS. PRECIPITABLE WATER VALUES REMAIN OVER 2 INCHES AND STORM MOTION WILL BE ONLY AROUND 10KT. THERE CONTINUES TO A SMALL THREAT FOR SEVERE STORMS WITH DAMAGING WIND GUSTS. IT APPEARS OUR NW COUNTIES WILL HAVE THE GREATEST POTENTIAL...BUT ANY SEVERE WOULD BE RATHER ISOLATED. LATER TONIGHT INTO MONDAY...THE FRONT WILL SLOW DOWN...THEN STALL JUST SE OF OUR AREA. MODELS SHOW A LINGERING INVERTED TROUGH OVER MID TN WITH A GRADIENT OF MOISTURE FROM SE TO NW. WE WILL KEEP A CHANCE FOR SHOWERS OR STORMS IN THE FORECAST FOR MONDAY...WITH THE HIGHER POPS IN THE SE AND VERY LOW POPS IN OUR NW COUNTIES. FOR TUESDAY THROUGH THURSDAY...OUR WEATHER WILL BE WARM AND HUMID. LOW WILL BE GENERALLY IN THE UPPER 60S TO AROUND 70 WITH HIGHS ABOUT 90. ISOLATED TO SCATTERED STORMS WILL REMAIN IN THE FORECAST...MAINLY PLATEAU WHERE PERSISTENT WEAK TROUGHING AND MOISTURE CONVERGENCE IS INDICATED. BY FRIDAY...A STRONG TROUGH WILL BE LOCATED OVER THE UPPER MIDWEST. THIS WAVE WILL DIG SE HELPING PULL A COLD FRONT THROUGH THE AREA. SCATTERED THUNDERSTORMS WILL DEVELOP AHEAD OF THE FRONT LATE THURSDAY INTO FRIDAY. DRY WX WITH NEAR NORMAL TEMPS WILL FOLLOW THE FRONT...WITH LOWS IN THE 60S...HIGHS IN THE MID 80S AND MORE PLEASANT HUMIDITY LEVELS. 13 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 07
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
627 PM CDT SUN AUG 5 2012 .UPDATE... FRONTAL BOUNDARY STILL A GOOD DISTANCE TO OUR NORTHWEST AND CURRENTLY EXTENDS ROUGHLY ALONG THE OHIO RIVER. 3HR PRESSURE CHANGE SHOWS AN INCREASE IN NEGATIVE VALUES ACROSS THE MID STATE COMPARED TO POINTS NW. THUS...THE FRONT IS SAGGING OUR WAY BUT WILL MOST LIKELY REACH NO FURTHER SOUTH THAN OUR NW COUNTIES LATE TONIGHT. OTW...EXAMINATION OF THE LATEST HRRR DATA SUGGESTS THAT THE ONGOING SCT CONVECTION SHOULD BEGIN TO FILL IN A BIT. SEEING SOME GOOD INFLOW ENERGY AT THE 10 KFT LEVEL BUT SO FAR...STORM INTENSITIES ARE NOT MUCH TO SPEAK OF. SHORTWAVE AND FRONTAL BOUNDARY SHOULD BE APPROACHING OUR NORTHWESTERN AREAS BY 12Z. THUS... SEE NO REASON TO UPDATE AT THIS POINT AND LOWER POPS AS THE LATEST RADAR TRENDS ARE SHOWING AN INCREASE IN COVERAGE ACROSS OUR NORTHWEST. THUS...WILL KEEP FORECAST GOING...AS IS...FOR NOW. && .PREV DISCUSSION... /ISSUED 259 PM CDT SUN AUG 5 2012/ DISCUSSION...CURRENTLY ACROSS THE MID STATE...A NE-SW BAND OF THUNDERSTORMS WAS MOVING SLOWLY EASTWARD ONTO THE CUMBERLAND PLATEAU. THIS BAND OF STORMS HAS DUMPED SOME HEAVY RAINFALL...ESPECIALLY NE OF BNA FROM GALLATIN TO HARTSVILLE AND GAINESBORO. TEMPERATURES VARIED CONSIDERABLY ACROSS THE AREA. LOCATIONS THAT EXPERIENCED STORMS WERE WELL BELOW EXPECTED HIGHS...WITH LATEST READINGS IN THE UPPER 70S TO LOWER 80S. THE DRIER LOCATIONS OVER THE FAR SOUTHEAST AND NORTHWEST HAD REACHED EXPECTED HIGHS...INCLUDING LOWER 90S AROUND CLARKSVILLE. WE HAVE LOW CONFIDENCE WITH SOME DETAILS DURING THE FIRST PERIOD OF THIS FORECAST. SHORT RANGE MODELS NEVER PICKED UP WELL ON THE BAND OF THUNDERSTORMS OVER THE AREA TODAY. ALSO...SHORT RANGE MODELS SHOWED CONSIDERABLE DEVELOPMENT AHEAD OF THE COLD FRONT...STILL LOCATED NW OF OUR AREA. SO FAR THERE HAS BEEN VERY LITTLE DEVELOPMENT AHEAD OF THE FRONT. OUR EARLIER THINKING WAS THAT STORMS WOULD INCREASE AHEAD OF THE FRONT WITH WIDESPREAD AND HEAVY THUNDERSTORMS CROSSING MID TN THIS EVENING. NOW IT APPEARS WE WILL HAVE TO BACK OFF. WE DO STILL EXPECT SOME ACTIVITY WITH THE FRONT...SINCE IT WILL BE RUNNING INTO MOIST AND UNSTABLE AIR WITH NEAR 2000 J/KG CAPE OVER OUR NW COUNTIES. BUT THE ACTIVITY WILL PROBABLY BE SCATTERED (AROUND 50 PERCENT POP)...RATHER THAN WIDESPREAD (80 PERCENT) AS WE HAD THOUGHT. ANY STORMS LATE TODAY INTO THIS EVENING COULD PRODUCE VERY HEAVY DOWNPOURS. PRECIPITABLE WATER VALUES REMAIN OVER 2 INCHES AND STORM MOTION WILL BE ONLY AROUND 10KT. THERE CONTINUES TO A SMALL THREAT FOR SEVERE STORMS WITH DAMAGING WIND GUSTS. IT APPEARS OUR NW COUNTIES WILL HAVE THE GREATEST POTENTIAL...BUT ANY SEVERE WOULD BE RATHER ISOLATED. LATER TONIGHT INTO MONDAY...THE FRONT WILL SLOW DOWN...THEN STALL JUST SE OF OUR AREA. MODELS SHOW A LINGERING INVERTED TROUGH OVER MID TN WITH A GRADIENT OF MOISTURE FROM SE TO NW. WE WILL KEEP A CHANCE FOR SHOWERS OR STORMS IN THE FORECAST FOR MONDAY...WITH THE HIGHER POPS IN THE SE AND VERY LOW POPS IN OUR NW COUNTIES. FOR TUESDAY THROUGH THURSDAY...OUR WEATHER WILL BE WARM AND HUMID. LOW WILL BE GENERALLY IN THE UPPER 60S TO AROUND 70 WITH HIGHS ABOUT 90. ISOLATED TO SCATTERED STORMS WILL REMAIN IN THE FORECAST...MAINLY PLATEAU WHERE PERSISTENT WEAK TROUGHING AND MOISTURE CONVERGENCE IS INDICATED. BY FRIDAY...A STRONG TROUGH WILL BE LOCATED OVER THE UPPER MIDWEST. THIS WAVE WILL DIG SE HELPING PULL A COLD FRONT THROUGH THE AREA. SCATTERED THUNDERSTORMS WILL DEVELOP AHEAD OF THE FRONT LATE THURSDAY INTO FRIDAY. DRY WX WITH NEAR NORMAL TEMPS WILL FOLLOW THE FRONT...WITH LOWS IN THE 60S...HIGHS IN THE MID 80S AND MORE PLEASANT HUMIDITY LEVELS. 13 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
412 PM EDT SAT AUG 4 2012 .SYNOPSIS... A WEAK COLD FRONT WILL APPROACH THE APPALACHIANS LATE ON SUNDAY AND SLOWLY MOVE THROUGH THE REGION ON MONDAY. THIS FRONT WILL PROVIDE THE TRIGGER FOR MORE WIDESPREAD SHOWERS AND THUNDERSTORMS... SOME WITH VERY HEAVY RAINFALL. THE FRONT WILL DRIFT INTO THE CAROLINAS BY TUESDAY AND DISSIPATE...BUT LINGERING MOISTURE BEHIND IT WILL ALLOW SOME SCATTERED SHOWERS AND THUNDERSTORMS TO CONTINUE THROUGH MUCH OF NEXT WEEK. && .NEAR TERM /TONIGHT THROUGH SUNDAY/... AS 0F 205 PM EDT SATURDAY... SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPED IN THE MOIST AND UNSTABLE AIR ACROSS OUR REGION THIS AFTERNOON. VORT LOBE WILL MOVE ACROSS THE APPALACHIANS ENHANCING SHOWERS AND THUNDERSTORMS. THE WRFARW-RNK...HRRR...NAM...RUC AND GFS KEEP SCATTERED STORMS THIS EVENING INTO TONIGHT. ANY SLOW MOVING THUNDERSTORM MAY PRODUCE HEAVY RAIN. FLASH FLOOD GUIDANCE IS RUNNING ABOUT 2 INCHES AN HOUR IN THE MTNS AND 3 INCHES AN HOUR IN THE PIEDMONT. LOCAL FLOODING PROBLEMS MAY BE A PROBLEM WITH TRAINING OF THUNDERSTORMS. WITH THE LOW LEVEL FLOW FROM THE SOUTH...EXPECT THE GREATEST CONVERGENCE ALONG THE BLUE RIDGE MOUNTAINS . SECONDARY AREA OF LOW LEVEL CONVERGENCE LIKELY TO DEVELOP THIS AFTERNOON INTO THIS EVENING OVER THE PIEDMONT. BOTH THE RUC AND NAM SHOWED SOME DEVELOPMENT OVER THE EAST THIS EVENING. LEANED TOWARDS THE NAM FOR TONIGHT POPS WITH ACTIVITY LINGER WELL INTO THE OVERNIGHT AIDED BY CONTINUED MOIST LOW LEVEL MOISTURE TRANSPORT INTO THE AREA UNDERNEATH NEARLY STATIONARY DISTURBANCE ALOFT. WENT WITH LOWS CLOSE TO THE ADJMETBC WITH READINGS FROM THE MID 60S IN THE MOUNTAINS TO THE LOWER 70S IN THE SOUTHEAST UNDER A BLANKET OF CLOUDS AND ELEVATED DEWPOINTS. UNSETTLED WEATHER WILL CONTINUE ON SUNDAY AHEAD OF APPROACHING FRONTAL BOUNDARY COMING OUT OF OHIO VALLEY. SOME INCREASE IN SHEAR AND SLIGHTLY STEEPER LAPSE RATES SUGGEST A BETTER SEVERE POTENTIAL AS WELL...WITH MORE ORGANIZED CLUSTERS COMING OUT OF OF WV AHEAD OF FRONT. WITH PWATS INCREASES THERE IS THE POTENTIAL FOR HEAVY RAINS. MAIN THREAT DURING THE DAY WOULD MAINLY BE IN THE WEST. PLAYED HIGH TEMPERATURES NEAR COOLER GUIDANCE WITH HIGHS FROM THE UPPER 70S IN THE MOUNTAINS TO AROUND 90 IN THE SOUTHEAST. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... AS OF 345 PM EDT SATURDAY... COLD FRONT NOT TO ARRIVE UNTIL SUNDAY NIGHT...AND IT MAY BE THAT BEST CHANCE FOR ORGANIZED CONVECTION...INCLUDING SLIGHT CHC OF SEVERE AND HEAVIEST RAINFALL RATES...DO NOT ARRIVE UNTIL THE EVENING. WITH SLOWER TIMING THE SEVERE POTENTIAL MAY BE LIMITED TO EXTREME WESTERN PORTIONS OF AREA IF IT COMES IN LATE ENOUGH IN EVENING...BUT HEAVY RAIN IS LOOKING LIKE A BIGGER CONCERN NOW UP UNTIL AT LEAST MIDNIGHT. CONTEMPLATED FLASH FLOOD WATCH FOR THIS PERIOD BUT WOULD NOT BE FOR MORE THAN ABOUT 6 HRS AS ANY HIGH RAINFALL RATES DISSIPATE THROUGHOUT THE EVENING...AND PROBABLY LIMITED TO FAR WESTERN PORTIONS...WV COUNTIES AND TAZEWELL MAINLY. SOME OF THESE LOCATIONS HAVE HAD SIGNIFICANT RAINFALL RECENTLY BUT IT`S BEEN HIT AND MISS. SO FOR NOW DECIDED TO HOLD OFF TO SEE IF FURTHER GUIDANCE SUGGESTS EITHER AN EARLIER START OR LONGER THREAT TIME INTO THE OVERNIGHT. INCREASES POPS SUNDAY NIGHT TO LIKELY AND CATEGORICAL IN WEST. MILDER OVERNIGHT LOWS MONDAY MORNING WITH EXTENSIVE CLOUD COVER AND LINGERING PRECIP...AND ALSO COOLER HIGHS MONDAY UNDER SIMILAR CONDITIONS AS FRONT SLOWLY MOVES ACROSS AREA. WENT SLIGHTLY COOLER THAN LOWEST GUIDANCE NUMBERS. NOT SURE HOW MUCH INSTABILITY WILL BE REALIZED FOR CONVECTION...SO MAINLY SHOWERS WITH ONLY SLIGHT CHC FIRST HALF OF DAY...AND WITH LIKELY POPS ACROSS THE SOUTH BY LATE IN THE DAY...STILL DOWNPLAYED THUNDER WITH ONLY A CHANCE. BETTER TSTORM COVERAGE MAY BE WELL SOUTH OF OUR AREA. BY TUESDAY SOME DIFFERENCES BETWEEN NAM AND GFS ARE EVIDENT...WITH NAM TAKEING FRONTAL BOUNDARY FARTHER SOUTH...AND GFS WASHING IT OUT ALLOWING BETTER SOUTHERLY FLOW TO RETURN. NAM HAS MID LEVEL DRY AIR AND SUBSIDENCE ACROSS THE NORTHERN HALF OF FCST AREA...SUPRESSING MOST CONVECTIVE THREATS DESPITE MODEST INSTABILITY...WHEREAS GFS REMAINS MOIST AND HINTS AT WEAK UPPER WAVE RIDING FROM SW TO NE HELPING TO SPREAD PRECIP BACK TO THE NORTH AGAIN. COMPROMISED BETWEEN THE TWO BUT WITH A LEAN TOWARD GFS...WITH SLIGHT CHC POPS ACROSS FAR NORTH BUT LIKELY ACROSS THE SOUTH. INCREASED CLOUD COVER AND LOWERED HIGHS A BUT AS WELL GIVEN FAVORED GFS SOLUTION...AGAIN GOING SLIGHTLY COOLER THAN LOWEST GUIDANCE. THIS HAS SOME BUST POTENTIAL IF NAM IS CORRECT AND PRECIP STAYS WELL SOUTH AND SOME CLEARING TAKES PLACE FARTHER NORTH. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 1245 PM EDT SATURDAY... DURING THE MID TO LATE PORTION OF THE WEEK...THE FRONTAL BOUNDARY IS EXPECTED TO STALL ALONG THE SOUTHERN PERIPHERY OF THE FORECAST AREA...IN RESPONSE TO A SLOWLY DIGGING UPPER LEVEL TROUGH OVER THE SOUTHERN GREAT LAKES REGION. THE CONSENSUS OF GUIDANCE IS NOT INDICATING THIS BOUNDARY WILL REMAIN CLOSE ENOUGH TO THE REGION TO CONTINUE TO PROVIDE A FOCUSING MECHANISM FOR DAILY CONVECTION...AIDED BY SOME WEAK UPPER LEVEL WAVES MOVING FROM SOUTHWEST TO NORTHEAST. GENERALLY DURING THE WED/THURS TIME FRAME THE PRECIP CHANCES WILL BE A LITTLE GREATER ACROSS THE SOUTHEAST CLOSER TO THE WEAKENING FRONTAL BOUNDARY...BUT AM CONTINUING WITH LOW TO MID CHANCE POPS FOR ALL LOCATIONS...EXCEPT FOR DIURNAL DROP TO SLIGHT CHC OVERNIGHT. THEN...AS THE UPPER TROUGH DEEPENS TOWARD THE END OF THE WEEK...A SECOND WEAK FRONTAL BOUNDARY WILL APPROACH FROM THE NORTH LATE FRIDAY OR EARLY SATURDAY...INCREASING THE CHANCES AGAIN FROM THE WEST. SOME MODELS ARE DEEPER WITH THIS TROUGH THAN OTHERS...AND SUGGEST A BETTER POSSIBILITY THAT THE FRONT WILL PUSH FARTHER THROUGH THE REGION BY LATE NEXT SATURDAY WITH POTENTIAL FOR SOME DRYING AND SLIGHTLY COOLER TEMPS. ONLY HEDGING SLIGHTLY TOWARD THIS IDEA SINCE THE CONSENSUS IN ENSEMBLES IS FOR A WEAKER TROUGH AND LIFTING NORTHEAST BY NEXT WEEKEND...SO STILL SOME UNCERTAINTY AS TO WHETHER THIS FRONT WILL REALLY PUSH THROUGH ANY FARTHER THAN THE ONE FOR EARLIER IN THE WEEK. WITH FRONTAL BOUNDARY LINGERING THROUGH MID WEEK JUST TO OUR SOUTH...LOOKS LIKE INSTABILITY MAY BE LIMITED WITH PLENTY OF CLOUD COVER EXPECTED...SO SEVERE POTENTIAL NOT ESPECIALLY HIGH...BUT RELATIVELY HIGH MOISTURE CONTENT WITH WEAK CONVERGENCE ALONG OLD BOUNDARY SUGGESTS A BIT MORE OF A FLASH FLOOD POTENTIAL ALTHOUGH THIS STILL MUCH DEPENDENT ON GETTING HIGHER RAINFALL RATES. INCREASED THE CLOUD COVER AND LOWERED HIGH TEMPS SOMEWHAT FROM PREVIOUS FORECAST FOR WED AND THURS...BUT STILL GOING CLOSE TO GFS-BASED GUIDANCE. SLIGHT WARMING BY FRIDAY AHEAD OF NEXT FRONTAL BOUNDARY BUT STILL BORDERLINE IF THERE WILL BE ANY 90S ACROSS THE PIEDMONT. TROPICAL ACTIVITY TO MONITOR WITH ERNESTO MOVING TOWARD YUCATAN AND INTO GULF BY MID WEEK BUT CURRENTLY EXPECTED TO REMAIN WELL SOUTH AND NOT INFLUENCE THE MID ATLANTIC REGION. A TROPICAL WAVE CURRENTLY OVER FLORIDA MAY EVENTUALLY EJECT SOME MOISTURE INTO OLD FRONTAL BOUNDARY TO OUR SOUTH...AND COULD HELP ENHANCE SOME OF THE PRECIP POTENTIAL BY MID WEEK. TROPICAL STORM FLORENCE WELL OUT IN THE ATLANTIC LIKELY TO REMAIN WELL AWAY FROM MAINLAND BEFORE WEAKENING. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... AS OF 1215 PM EDT SATURDAY... LOW CLOUDS AND CONVECTION WILL HINDER AVIATION OPERATIONS THIS AFTERNOON INTO TONIGHT. ATMOSPHERE REMAINS VERY MOIST...WITH UPPER VORT REMAINING ALONG THE APPALACHIANS THIS AFTERNOON. SCATTERED MVFR SHOWERS AND THUNDERSTORMS EXPECTED THIS AFTERNOON INTO TONIGHT...KEPT VCTS AT TAF SITES UNTIL SUNSET. BELIEVE THAT BCB AND DAN TAF SITES HAS THE BEST CHANCE OF A THUNDERSTORM. DAN IS LOCATED BY THE RICHEST MOISTURE COMBINED WITH BEST INSTABILITY CREATED BY SOLAR HEATING. ANY THUNDERSTORMS THIS AFTERNOON WILL BE SLOW MOVING AND COULD CONTAIN HEAVY DOWNPOURS. EXPECT AREAS OF FOG TO DEVELOP OVERNIGHT ESPECIALLY WHERE THUNDERSTORMS OCCUR THIS AFTERNOON INTO THIS EVENING. DEEPER MOISTURE REMAINS INTO EARLY NEXT WEEK WITH GREATER COVERAGE OF SHOWERS AND STORMS...ESPCLY DURING THE AFTERNOON AND EVENING EACH DAY THROUGH MONDAY. LOCAL MVFR/IFR CONDITIONS WILL BE ASSOCIATED WITH THE MORE ORGANIZED STORMS. OUTSIDE OF THIS MAINLY DIURNALLY DRIVEN CONVECTION...THE ONLY OTHER FLIGHT WEATHER HAZARDS WOULD BE FROM OVERNIGHT VALLEY FOG. A COLD FRONT IS EXPECTED TO DROP SOUTHEAST OUT OF THE OHIO VALLEY MONDAY...CROSSING THE MID ATLANTIC REGION. WITH THE PASSAGE OF THIS FRONT...WINDS SHOULD BECOME NORTHERLY...WITH A DAY OR TWO OF DRY WEATHER AND VFR CONDITIONS FOLLOWING THE FRONTAL PASSAGE FOR MID WEEK. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...SK NEAR TERM...KK SHORT TERM...SK LONG TERM...SK AVIATION...KK/PM
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
258 PM CDT SAT AUG 4 2012 .SHORT TERM...TODAY THROUGH SUNDAY. STORMS FIRED ALONG BOUNDARY IN MANITOWOC AND WAUPACA COUNTIES THIS AFTN...AS THE MORNING RUNS OF THE HRRR MODEL INDICATED. CORRIDOR OF HIGH INSTABILITY FROM S WI INTO THE FAR E PART OF THE STATE AND CONVERGENCE ALONG BOUNDARIES ENOUGH TO INITIATE DEEP CONVECTION. MAIN LINE OF SHOWERS AND STORMS...HOWEVER...MOVING INTO THE WEST PART OF FORECAST AREA. THIS WILL MOVE ACROSS THE AREA LATE THIS AFTERNOON AND EARLY EVENING PER LATEST RUN OF HRRR. BEST CHANCE OF SEVERE WILL BE SOUTH OF FORECAST AREA...BUT STILL A THREAT IN THE EAST-CENTRAL IN UNSTABLE AIRMASS AND INTERACTION OF LOW-LEVEL BOUNDARIES. UPPER TROF WILL QUICKLY SWING THROUGH TONIGHT. SMALL CHANCE FOR LINGERING SHOWERS BEHIND MAIN LINE LATER THIS EVENING. OTHERWISE...CLEARING SKIES ACROSS MUCH OF AREA. EXCEPTION IS IN THE FAR NORTH CLOSER TO THE UPPER LOW AND RESIDUAL MOISTURE. TEMPS TONIGHT AND SUNDAY ARE A BLEND OF MODELS...CLOSE TO PREVIOUS FORECAST. .LONG TERM...SUNDAY NIGHT THROUGH NEXT FRIDAY. MEAN LONGWAVE PATTERN FOR THE EXTENDED FORECAST PERIOD GENERALLY CHARACTERIZED BY A TROUGH OVER THE OHIO VALLEY AND RIDGE OVER THE INTERMOUNTAIN WEST. WESTERN GREAT LAKES REGION WILL RESIDE IN NORTHWESTERLY FLOW REGIME WITH AN OCCASIONAL EMBEDDED SHORTWAVE DISTURBANCES TRAVERSING THE AREA. TIMING AND INTENSITY OF EMBEDDED SHORTWAVE DISTURBANCES WITHIN THIS FLOW REGIME ARE TYPICALLY PROBLEMATIC...THUS FORECAST CONFIDENCE IN THIS REGARD IS LOW TO MEDIUM. EARLY IN THE WORK WEEK... DAYTIME TEMPERATURES WILL START OUT ABOVE NORMAL...THEN SLOWLY FALL BACK TO NEAR...OR PERHAPS SLIGHTLY BELOW NORMAL FOR EARLY AUGUST. SURFACE HIGH PRESSURE WILL CONTINUE TO BUILD EASTWARD ACROSS THE FORECAST AREA SUNDAY NIGHT INTO MONDAY. WENT ON THE COOLER SIDE SIDE OF AVAILABLE GUIDANCE WITH RESPECT TO MIN TEMPERATURES SUNDAY NIGHT GIVEN CLEAR SKIES...LIGHT WINDS AND RATHER DRY DRY AIRMASS. MONDAY LOOKS LIKE A PLEASANT DAY WITH SUNNY SKIES...RELATIVELY LIGHT WINDS WITH DAYTIME HIGHS A FEW DEGREES ABOVE NORMAL. SHORTWAVE DISTURBANCE THEN FORECAST TO HEAD SOUTHEAST ACROSS SOUTHERN HUDSON BAY MONDAY NIGHT INTO EARLY TUESDAY. ASSOCIATED COLD FRONT WILL GET SHOVED SOUTHEAST TOWARD NORTHWEST WISCONSIN BY AROUND 06Z TUESDAY. APPEARS TO BE A PLUME OF HIGHER MID-LEVEL LAPSE RATES AND MODEST 850 WAA OUT AHEAD OF THIS SYSTEM. HOWEVER AVAILABLE MOISTURE IS SOMEWHAT LIMITED. THUS...HAVE MAINLY SMALL CHANCE POPS OVER NORTHWEST COUNTIES OVERNIGHT...THEN CARRY THESE SMALL POPS SOUTHEAST ACROSS THE AREA TUESDAY MORNING. MAJORITY OF GUIDANCE SUGGEST THAT FRONT WILL PASS SOUTHEAST OF THE FORECAST AREA BY ABOUT 18Z TUESDAY WITH CAA TO ENSUE DURING THE AFTERNOON. WEAK HIGH PRESSURE RETURNS TO THE AREA TUESDAY NIGHT INTO EARLY WEDNESDAY...WITH NEXT DISTURBANCE ALREADY APPROACHING THE NORTHERN MISSISSIPPI VALLEY BY WEDNESDAY MORNING. MODEL CONSENSUS SUGGESTS THIS SYSTEM WILL BE A BIT MORE POTENT AS IT TRAVERSES SOUTHEAST ACROSS THE FORECAST AREA THURSDAY. OPERATIONAL GFS AND ECMWF ARE A BIT FURTHER SOUTH WITH STRENGTHENING SURFACE LOW WHILE GEM A BIT FURTHER NORTH. BOTTOM LINE IS THAT IT LOOKS LIKE THERE WILL BE A PRETTY DECENT CHANCE FOR SHOWERS AND THUNDERSTORMS DURING THE DAY ON THURSDAY. BUMPED UP POPS FROM PREVIOUS FORECAST. SOME MODEL DIFFERENCES ON EVOLUTION OF UPPER TROUGH AND ASSOCIATED SURFACE LOW THURSDAY NIGHT INTO FRIDAY. SYSTEM DOES APPEARS TO SLOW DOWN SOMEWHAT AS IT DEEPENS JUST TO THE EAST OF THE FORECAST AREA...THUS PRECIPITATION COULD VERY WELL LINGER INTO FRIDAY ESPECIALLY OVER THE EASTERN HALF OF THE FORECAST AREA. CLOUDS...SCATTERED PRECIPITATION AND NORTHEASTERLY BOUNDARY LAYER FLOW ON FRIDAY WILL LIKELY HOLD TEMPERATURES MAINLY IN THE 70S. && .AVIATION...LINE OF STORMS FORECAST TO ENTER WESTERN PART OF FORECAST AREA BY 18Z...THEN MOVE EAST THROUGH AREA BY 00Z. IFR CONDITIONS CAN BE EXPECTED WITH STRONGER STORMS. WIND GUSTS OVER 40 KTS POSSIBLE WITH STORMS AT AIRPORTS IN CENTRAL AND EAST- CENTRAL WI. BEST CHANCE FOR SEVERE WILL BE OVER SOUTHERN PART OF STATE. JKL && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ JKL/ESB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1225 PM CDT SAT AUG 4 2012 .SHORT TERM...THROUGH MONDAY 246 AM CDT SAT AUG 4 2012 MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TODAY. SURFACE ANALYSIS THIS MORNING SHOWS AN AREA OF LOW PRESSURE OVER SOUTHEAST SASKATCHEWAN WITH A COLD FRONT EXTENDING SOUTH INTO EASTERN NEBRASKA. LOCAL AND REGIONAL RADARS SHOWING A LINE OF CONVECTION OUT AHEAD OF THE FRONT FROM NORTHWEST WISCONSIN INTO NORTHERN IOWA. ONGOING CONVECTION WAS FUELED BY A SHORT WAVE TROUGH THAT EJECTED OUT AHEAD OF THE MAIN LONG WAVE TROUGH AND BY LOW LEVEL WARM AIR ADVECTION AHEAD OF THE WAVE. ACTIVITY HAS BEEN SLOWLY WEAKENING AS IT MOVES EAST AS VWP WIND PROFILES SHOWS JUST A WEAK MOISTURE TRANSPORT SIGNAL OUT AHEAD OF THE LINE ALONG WITH LESS INSTABILITY TO THE EAST. THE 03.12Z AND 04.00Z HI-RES ARW HANDLED THIS SYSTEM EXTREMELY WELL AND SUGGESTS IT WILL CONTINUE TO DIMINISH BUT HOLD TOGETHER AS IT MOVES ACROSS THE FORECAST AREA...EXITING TO THE EAST BEFORE 12Z. ANOTHER AREA OF CONVECTION OVER SOUTHWEST MINNESOTA INTO NEBRASKA IS IN A MORE FAVORABLE POSITION TO MAINTAIN ITSELF THROUGH THE NIGHT. THERE IS A BETTER LOW LEVEL JET FEEDING INTO THIS AIDING THE ISENTROPIC UP GLIDE. AGAIN...THE HI- RES ARW HAS A GOOD HANDLE ON THIS AS DOES THE 04.08Z HRRR WHICH BRINGS THIS ACTIVITY INTO THE FORECAST AREA BEFORE IT DISSIPATES BY MID MORNING AS THE LOW LEVEL JET DECREASES AFTER SUNRISE. HAVE ACCOUNTED FOR THIS TREND WITH A BAND OF 60 PERCENT CHANCES FROM SOUTHWEST TO NORTHEAST THROUGH 15Z AND THEN BACKED DOWN TO A 30 TO 40 PERCENT CHANCE FOR THE REMAINDER OF THE MORNING. ATTENTION FOR THE AFTERNOON THEN TURNS TO THE LONG WAVE TROUGH TO THE WEST. THIS IS EXPECTED TO CONTINUE LIFTING NORTHEAST THROUGH THE DAY WITH THE UPPER LEVEL LOW GOING INTO WESTERN ONTARIO BY LATE AFTERNOON. THE LATEST SET OF MODELS NOW SUGGEST THE TROUGH AXIS WILL REMAIN POSITIVELY TILTED THROUGH THE DAY AND NOT TAKE ON MORE OF A NEUTRAL TILT UNTIL TONIGHT ONCE IT IS EAST OF THE AREA. THIS IS EXPECTED TO RESULT IN ABOUT 8 PVU/S OF VORTICITY ADVECTION IN THE 500-300 MB LAYER COMING ACROSS THIS AFTERNOON WITH AN INCREASE TONIGHT ONCE IT IS TO THE EAST OF THE AREA. IN THE LOW LEVELS...THE FRONT SHOULD COME THROUGH WITH WEAK TO MODERATE FRONTOGENESIS IN THE 1000-700 MB LAYER ALONG WITH UP TO 2 UBAR/S OF UP GLIDE ON THE 310K ISENTROPIC SURFACE. THIS FORCING WILL ALSO BE AIDED BY PRETTY GOOD DIVERGENCE ALOFT AS THE AREA WILL BE UNDER THE RIGHT ENTRANCE REGION OF THE 100+ JET CORE AT 300 MB. THIS FORCING IS EXPECTED TO BE ENOUGH TO GENERATE ANOTHER LINE OF CONVECTION ALONG THE FRONT THIS AFTERNOON WITH THE BEST CHANCES FOR REDEVELOPMENT OVER THE EASTERN PORTIONS OF THE FORECAST AREA. WITH THE TIMING OF THE FRONT...THERE JUST MAY NOT BE ENOUGH TIME FOR RECOVERY TO OCCUR OVER THE WEST FOR MUCH TO DEVELOP. SEVERAL OF THE MODELS SUGGEST THE POTENTIAL FOR A NARROW CORRIDOR OF UPPER 60S TO AROUND 70 DEW POINTS ALONG THE FRONT WHICH COULD LEAD TO ML CAPES OF 2500 J/KG. THE BEST 0-6KM SHEAR DOES NOT LOOK LIKE IT WILL CATCH UP WITH THE INSTABILITY BECAUSE OF THE POSITIVE TILT OF THE LONG WAVE TROUGH...BUT UP TO 30 KNOTS OF 0-3KM SHEAR SHOULD RESIDE OVER THE INSTABILITY AXIS. THIS WILL PROVIDE ENOUGH SHEAR TO HELP ORGANIZE THE EXPECTED DEVELOPMENT ALONG THE FRONT ALONG WITH POSSIBLY SUPPORTING SOME SEVERE STORMS. THE 04.00Z NAM SUGGEST THERE WILL BE BETWEEN 1250-1500 J/KG OF DCAPE AVAILABLE ALONG WITH FAVORABLE TEMPS ALOFT FOR SOME HAIL PRODUCTION AS HEIGHTS LOWER WITH THE APPROACHING LONG WAVE TROUGH. SO IF THE STORMS DO BECOME SEVERE...DAMAGING WINDS AND LARGE HAIL WILL BE THE MAIN THREATS. HAVE LEFT THE RAIN CHANCES AT 60 PERCENT FOR THE AFTERNOON AS SOME CONCERN ON HOW FAST THE CLOUDS FOR THIS MORNING/S CONVECTION WILL CLEAR OUT. IF THESE HOLD ON LONGER THAN EXPECTED...THE INSTABILITY WILL NOT BUILD SETTING UP THE POTENTIAL FOR LESS CONVECTION TO OCCUR. ONCE THIS SYSTEM GOES THROUGH...A NORTHWEST FLOW ALOFT WILL BE IN PLACE OVER THE UPPER MIDWEST. THE NAM AND 03.12Z ECMWF ARE SUGGESTING A SHORT WAVE TROUGH IN THIS FLOW WILL COME ACROSS MONDAY NIGHT PUSHING A WEAK COLD FRONT THROUGH THE AREA. THIS FRONT LOOKS TO HAVE PRETTY DECENT FRONTOGENESIS WITH IT AND WILL CARRY A SMALL RAIN CHANCE ACROSS MUCH OF THE AREA. .LONG TERM...MONDAY NIGHT THROUGH FRIDAY 246 AM CDT SAT AUG 4 2012 THE NORTHWEST FLOW ALOFT WILL CONTINUE THROUGH THE PERIOD WITH THE NEXT SHORT WAVE TROUGH EXPECTED TO PASS OVER WEDNESDAY NIGHT AND THURSDAY. THIS SHOULD PUSH ANOTHER WEAK COLD FRONT THROUGH FOR A SMALL CHANCE OF RAIN. THE 04.00Z ECMWF SUGGESTS THIS SHORT WAVE TROUGH WILL THEN BE FOLLOWED BY AN UPPER LEVEL LOW DROPPING DOWN FROM THE HUDSONS BAY AREA. AS THIS MOVES ACROSS THE GREAT LAKES REGION SOME RAIN CHANCES WILL LINGER INTO THURSDAY NIGHT AND FRIDAY. && .AVIATION...THIS AFTERNOON THROUGH SUNDAY 1225 PM CDT SAT AUG 4 2012 LINE OF MVFR/IFR SHRA/TSRA WILL BE EXITING EAST OF KLSE BY 19Z WITH ONLY LINGERING -SHRA THRU 20Z. SMALL AREA OF POST-FRONTAL STRATO-CU IN THE 2500 TO 3500 FT RANGE WILL ROTATE ACROSS THE TAF SITES THRU ABOUT 21Z...BUT BE PROGRESSIVE WITH DECREASING CLOUDS/CLEARING SKIES FOR THE LATE AFTERNOON/EVENING HOURS AS A DRIER/COOLER AIRMASS AND SUBSIDENCE SPREAD ACROSS THE AREA. OF CONCERN IS THE MVFR CLOUD SHIELD OVER MUCH OF ND/NORTHERN MN...WRAPPED AROUND/BEHIND THE SFC-850BM LOW. INCREASING NORTHWEST FLOW BEHIND THE DEPARTING LOW/COLD FRONT WILL ADVECT THIS MOISTURE/CLOUDS SOUTHEAST TONIGHT. ADDED A PERIOD OF 2500-3000FT CLOUDS/CIGS TO BOTH KRST/LSE FOR THE LATE EVENING/OVERNIGHT HOURS AS THIS MOISTURE ROTATES ACROSS THE AREA. DRIER HIGH PRESSURE/ANTI-CYCLONIC FLOW BUILDS INTO THE AREA FOR SUN. WITH DIURNAL WARMING/MIXING GOOD VFR EXPECTED SUNDAY WITH ONLY SCT VFR CUMULUS..AND CLOUD BASES RISING THRU THE DAY. && .ARX WATCHES/WARNINGS/ADVISORIES... 246 AM CDT SAT AUG 4 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM....04 AVIATION.....RRS
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
1055 AM CDT SAT AUG 4 2012 UPDATED NEAR-TERM AND AVIATION PORTION FOR 18Z TAF ISSUANCE .SHORT TERM...TODAY THROUGH SUNDAY. NEAR-TERM... HAD TO ADJUST TIMING OF CONVECTION INTO AREA PER EXTRAPOLATION OF IA CONVECTION AND 04/12Z RUN OF HRRR AND RAP. BEGAN PRECIP EARLIER THIS AFTERNOON AND ENDING EARLIER IN THE EVENING AS FRONT IS MOVING A BIT FASTER THAN EARLIER ANTICIPATED. BEST SEVERE PARAMETERS POINT TO THE SOUTH OF THE FORECAST AREA...BUT SHORT- TERM MODELS INDICATE SCATTERED CONVECTION AHEAD OF MAIN LINE BEGINNING BY 19Z IN EAST-CENTRAL WI IN CORRIDOR OF INSTABILITY AND DIFFERENTIAL HEATING. OTHERWISE...MAIN LINE /HEAVIEST RAIN/ EXPECTED TO MOVE THROUGH THE FORECAST AREA BY ABOUT 00Z. JKL PREVIOUS SHORT TERM DISCUSSION... REGARDLESS OF THE SEVERITY OF THE THUNDERSTORMS WE SHOULD GET A LINE OF STORMS WITH HEAVY RAIN. PRECIPITABLE WATER VALUES OVER 2 INCHES ARE FORECAST DURING THE LATE AFTERNOON AND EARLY EVENING. THE FRONT SHOULD BE MOVING QUICK ENOUGH TO PREVENT WIDESPREAD FLOODING BUT WOULD NOT BE SURPRISED IF THERE ARE SOME 1 TO 2 INCH PER HOUR RAINFALL RATES AND LOCAL URBAN OR SMALL STREAM FLOODING. AREA SOUTH OF HIGHWAY 29 IS SO DRY THAT THE RAINFALL IS MUCH NEEDED. THE FRONT WILL EXIT TONIGHT AND THE RAIN WILL END BY MIDNIGHT IN MOST PLACES. COOLER AND DRIER AIR WILL ARRIVE OVERNIGHT AND END THE NEED FOR AIR CONDITIONING FOR AWHILE. "REAL WISCONSIN" SUMMER WEATHER SHOULD RETURN SUNDAY WITH HIGHS IN THE 70S...LOW HUMIDITIES AND A NICE BREEZE. IT WILL PROBABLY BE THE NICEST DAY SINCE JUNE 25TH OVER MUCH OF THE AREA. .LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY. THE LATEST MEDIUM RANGE MODELS PLACE THE WESTERN GREAT LAKES REGION WITHIN NW FLOW ALOFT FOR MUCH OF THE NEXT WEEK. SEVERAL SHORTWAVES WITHIN THIS NW FLOW COULD IMPACT THE REGION...BUT OUTSIDE OF THE FIRST WAVE ARRIVING MONDAY NIGHT...MODELS DO NOT HAVE A GOOD HANDLE OF THESE IMPULSES. COULD SEE ANOTHER WAVE DROP INTO THE AREA WEDNESDAY INTO WEDNESDAY NIGHT AND ANOTHER LATER IN THE WEEK...BUT MOISTURE WILL BE LACKING WITH EACH SYSTEM. WILL HAVE TO TAKE A GENERAL BLEND MID-WEEK ONWARD. SUNDAY NIGHT INTO MONDAY NIGHT...HIGH PRESSURE WILL MOVE FROM THE CENTRAL GREAT PLAINS TO THE SOUTHERN GREAT LAKES SUNDAY NIGHT. WINDS LOOK LIGHT ENOUGH FOR DECOUPLING AND WILL SEE MOSTLY CLEAR CONDITIONS...SO WILL SIDE ON THE COLD SIDE OF GUIDANCE FOR LOW TEMPS. ON MONDAY...AN AMPLIFYING NORTHERN STREAM SHORTWAVE WILL DROP A COOL FRONT INTO LAKE SUPERIOR IN THE AFTERNOON. BUT HIGH PRESSURE WILL STICK AROUND OUR AREA TO GIVE A MOSTLY SUNNY AND WARM DAY WITH HIGHS IN THE LOW TO MID 80S. THIS FRONT WILL THEN DROP ACROSS NORTHERN WISCONSIN AND INTO CENTRAL WISCONSIN MONDAY NIGHT. HARD TO SAY IF THERE WILL BE ENOUGH MOISTURE FOR PRECIP...BUT POTENTIAL WILL EXIST SO WILL KEEP A SPOTTY MENTION IN THE FORECAST FOR NORTHERN WISCONSIN. REST OF THE FORECAST...THE FRONT WILL FINISH CROSSING CENTRAL AND NORTHEAST WISCONSIN TUESDAY MORNING BEFORE DEPARTING BY THE AFTERNOON. NOT TO THRILLED WITH PRECIP CHANCES IN THE MORNING...AS MID-LEVEL MOISTURE WILL HAVE ALREADY PULLED OUT BY THIS POINT. WILL REMOVE POPS. TEMPS WILL COOL SLIGHTLY BEHIND THE FRONT TO THE UPPER 70S AND LOWER 80S. HIGH PRESSURE WILL DRIFT ACROSS THE REGION TUESDAY NIGHT BUT THEN WILL BE ANTICIPATING THE NEXT WAVE SWINGING ACROSS THE REGION WEDNESDAY INTO WEDNESDAY NIGHT. WILL HAVE SOME SMALL PRECIP CHANCES OVER THIS PERIOD. MAY HAVE ANOTHER WAVE ARRIVE FRIDAY INTO SATURDAY...THOUGH AGAIN PRECIP CHANCES LOOK SMALL. WILL TRY TO REMOVE CHANCES WHERE POSSIBLE UNTIL MODELS GET A BETTER HANDLE ON THE DETAILS. && .AVIATION...LINE OF STORMS FORECAST TO ENTER WESTERN PART OF FORECAST AREA BY 18Z...THEN MOVE EAST THROUGH AREA BY 00Z. IFR CONDITIONS CAN BE EXPECTED WITH STRONGER STORMS. WIND GUSTS OVER 40 KTS POSSIBLE WITH STORMS AT AIRPORTS IN CENTRAL AND EAST- CENTRAL WI. BEST CHANCE FOR SEVERE WILL BE OVER SOUTHERN PART OF STATE. JKL && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1003 AM CDT SAT AUG 4 2012 .UPDATE...MAKING CHANGES ON TIMING AS IOWA CONVECTION LOOKS TO BE OUR SHOW THIS AFTERNOON. HAVE UPPED POPS TO CATEGORICAL AND HAVE ADDED SEVERE TO THE GRIDS AS WELL. AXIS OF 1000 DCAPE INTO SOUTHERN WI...WITH WATER VAPOR/RUC COMBO SHOWING SHORTWAVE NE KS VICINITY SHIFTING NORTHEAST. MID LEVEL LAPSE RATES OF AROUND 7 WITH BUILDING CAPES INTO SRN WI. ONLY THIN CIRRUS TO CONTEND SO PLENTY OF HEATING. 0-8 KM SHEAR AROUND 50 KNOTS...AND SEEING SOME 40 KNOTS 0-6 KM. 0-1 SHEAR MORE SO- SO...TORNADO THREAT MINIMAL BUT NON-ZERO. MAIN CONCERN WILL BE FOR DAMAGING WINDS. PC && .AVIATION/18Z TAFS/...HAVE ADJUSTED TIMING OF CONVECTION BASED ON TRENDS ACROSS IOWA. LOOKS LIKE AROUND 19Z IN KMSN AND AROUND 21Z TOWARDS KMKE. PC && .PREV DISCUSSION... /ISSUED 330 AM CDT SAT AUG 4 2012/ TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM BIG CONCERN IS IMPACT OF CURRENT LINE OF CONVECTION ON THE EVOLUTION AND TIMING OF THUNDERSTORMS ACROSS FORECAST AREA LATER TODAY. SUB-SEVERE WIND REPORTS SINCE 12 MIDNIGHT HAVE INDICATED A WEAKENING TREND TO THE LINE...SUPPORTED BY REDUCED LIGHTNING ACTIVITY AND A SLIGHT WARMING OF CLOUD TOPS. LINE WILL REACH NW CWA BETWEEN 245 AM AND 3AM ON CURRENT PACE. HRRR AND RAP SUGGEST A RAPID WEAKENING OF CURRENT LINE AS IT MOVES AWAY FROM MAIN LOW-LEVEL JET AXIS AND INSTABILITY...THEN ALL MODELS SHOW A RE-FIRING OF CONVECTION ALONG SURFACE FRONT MID-LATE MORNING FROM WEST CENTRAL WI INTO FAR NE IOWA AS FRONTOGENETIC RESPONSE INCREASES AHEAD OF TROUGH. STILL FEEL BEST OPPORTUNITY FOR STRONG/SEVERE IN CWA DURING THE LATE AFTERNOON INTO THIS EVENING WITH ENHANCED FORCING AND 0 TO 6KM SHEAR INCREASING TO 30 TO 40 KTS AHEAD OF COLD FRONT AND POSITIVE-TILT 500 MB TROUGH AS IT SWINGS TO A MORE NEUTRAL POSITION WHILE CROSSING THE WESTERN GREAT LAKES TONIGHT. FORCING FOR ASCENT WILL BE AIDED BY UPPER LEVEL DIVERGENCE OF RRQ OF 100-110KT 250 MB JET MAX LIFTING ACROSS WRN GREAT LAKES REGION DURING THE LATE AFTERNOON AND EVENING. IF CLOUD DEBRIS DOESN/T OVERLY INHIBIT DAYTIME HEATING...SURFACE BASED CAPE OVER CWA RISES TO AROUND 1600 J/KG...COMPUTED LIFTED INDICES OF -5 TO -7...PRECIPITABLE WATER VALUES OF 1.8 TO 2 INCHES. FEEL CLOUDS WILL THIN ENOUGH AND WARM ADVECTION AHEAD OF FRONT WILL BRING HIGH TEMPERATURES IN THE LOW 90S INLAND...WITH SOUTHERLY WINDS TURNING INSHORE ENOUGH TO KEEP LAKESHORE AREAS IN THE MID-UPPER 80S. BUFKIT SOUNDINGS SHOW WELL MIXED BOUNDARY LAYER BY LATE AFTERNOON...WITH DRY SUB-CLOUD LAYER ENHANCING POTENTIAL FOR DAMAGING WINDS REFLECTED IN FORECAST DOWNDRAFT CAPE OF 1500 TO 2000 J/KG. PRECIPITATION ENDS IN THE EAST WITH TROUGH PASSAGE AROUND 06Z WITH DRIER AIR POURING IN ON NORTHWEST WINDS AS HIGH BUILDS IN FROM THE WEST. SUNDAY AND MONDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH HIGH PRESSURE TO MOVE IN BEHIND THE COLD FRONT FOR SUNDAY AND MONDAY...BRINGING PLEASANT WEATHER TO SOUTHERN WISCONSIN. MAY SEE A FEW LINGERING CLOUDS NORTH SUNDAY AS THE UPPER TROUGH AXIS SWINGS THROUGH...WITH SUNNY SKIES ACROSS THE FORECAST AREA MONDAY. COOLER AIR BEHIND THE DEPARTING SYSTEM WILL RETURN TEMPERATURES TO NEAR NORMAL SUNDAY...WARMING BACK UP JUST A BIT MONDAY. TUESDAY AND WEDNESDAY....FORECAST CONFIDENCE...MEDIUM MAY SEE A WEAK WAVE OR TWO SLIDE THROUGH TUESDAY AND WEDNESDAY...BUT OVERALL PRECIP CHANCES TOO LOW FOR POPS AT THIS TIME. WARM ADVECTION IS EXPECTED INTO THE AREA WITH UPPER RIDGE TO THE WEST...SO SHOULD SEE TEMPS RUN A FEW DEGREES ABOVE NORMAL. THURSDAY AND FRIDAY...FORECAST CONFIDENCE...MEDIUM MODELS ADVERTISING A STRONGER WAVE FOR THURSDAY...SO WENT WITH CHANCE POPS MOST PLACES. LOOKS QUIETER FOR FRIDAY BEHIND THE SYSTEM. NO BIG CHANGE EXPECTED IN TEMPS THROUGH THE END OF THE WORK WEEK...WITH 80S CONTINUING. AVIATION/12Z TAFS/... WILL ADJUST TAFS FOR MVFR/IFR FOG IN THE NEAR TERM...THEN VFR UNTIL EXPECTED THUNDERSTORMS BRING MVFR CONDITIONS AND GUSTY WINDS. 000Z AND RAPID REFRESH MODELS SUPPORT KEEPING LATE AFTERNOON/EARLY EVENING TIMING FOR THUNDERSTORMS THAT IS IN CURRENT FORECAST. NORTHWEST WINDS KEEP BOUNDARY LAYER MIXED...WITH DRY AIR MOVING IN BEHIND COLD FRONT KEEPING OUT ANY CHANCE OF POST-FRONTAL LOW CLOUDS/FOG AT THIS TIME. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...REM SUNDAY THROUGH FRIDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
640 AM CDT SAT AUG 4 2012 .SHORT TERM...THROUGH MONDAY 246 AM CDT SAT AUG 4 2012 MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TODAY. SURFACE ANALYSIS THIS MORNING SHOWS AN AREA OF LOW PRESSURE OVER SOUTHEAST SASKATCHEWAN WITH A COLD FRONT EXTENDING SOUTH INTO EASTERN NEBRASKA. LOCAL AND REGIONAL RADARS SHOWING A LINE OF CONVECTION OUT AHEAD OF THE FRONT FROM NORTHWEST WISCONSIN INTO NORTHERN IOWA. ONGOING CONVECTION WAS FUELED BY A SHORT WAVE TROUGH THAT EJECTED OUT AHEAD OF THE MAIN LONG WAVE TROUGH AND BY LOW LEVEL WARM AIR ADVECTION AHEAD OF THE WAVE. ACTIVITY HAS BEEN SLOWLY WEAKENING AS IT MOVES EAST AS VWP WIND PROFILES SHOWS JUST A WEAK MOISTURE TRANSPORT SIGNAL OUT AHEAD OF THE LINE ALONG WITH LESS INSTABILITY TO THE EAST. THE 03.12Z AND 04.00Z HI-RES ARW HANDLED THIS SYSTEM EXTREMELY WELL AND SUGGESTS IT WILL CONTINUE TO DIMINISH BUT HOLD TOGETHER AS IT MOVES ACROSS THE FORECAST AREA...EXITING TO THE EAST BEFORE 12Z. ANOTHER AREA OF CONVECTION OVER SOUTHWEST MINNESOTA INTO NEBRASKA IS IN A MORE FAVORABLE POSITION TO MAINTAIN ITSELF THROUGH THE NIGHT. THERE IS A BETTER LOW LEVEL JET FEEDING INTO THIS AIDING THE ISENTROPIC UP GLIDE. AGAIN...THE HI- RES ARW HAS A GOOD HANDLE ON THIS AS DOES THE 04.08Z HRRR WHICH BRINGS THIS ACTIVITY INTO THE FORECAST AREA BEFORE IT DISSIPATES BY MID MORNING AS THE LOW LEVEL JET DECREASES AFTER SUNRISE. HAVE ACCOUNTED FOR THIS TREND WITH A BAND OF 60 PERCENT CHANCES FROM SOUTHWEST TO NORTHEAST THROUGH 15Z AND THEN BACKED DOWN TO A 30 TO 40 PERCENT CHANCE FOR THE REMAINDER OF THE MORNING. ATTENTION FOR THE AFTERNOON THEN TURNS TO THE LONG WAVE TROUGH TO THE WEST. THIS IS EXPECTED TO CONTINUE LIFTING NORTHEAST THROUGH THE DAY WITH THE UPPER LEVEL LOW GOING INTO WESTERN ONTARIO BY LATE AFTERNOON. THE LATEST SET OF MODELS NOW SUGGEST THE TROUGH AXIS WILL REMAIN POSITIVELY TILTED THROUGH THE DAY AND NOT TAKE ON MORE OF A NEUTRAL TILT UNTIL TONIGHT ONCE IT IS EAST OF THE AREA. THIS IS EXPECTED TO RESULT IN ABOUT 8 PVU/S OF VORTICITY ADVECTION IN THE 500-300 MB LAYER COMING ACROSS THIS AFTERNOON WITH AN INCREASE TONIGHT ONCE IT IS TO THE EAST OF THE AREA. IN THE LOW LEVELS...THE FRONT SHOULD COME THROUGH WITH WEAK TO MODERATE FRONTOGENESIS IN THE 1000-700 MB LAYER ALONG WITH UP TO 2 UBAR/S OF UP GLIDE ON THE 310K ISENTROPIC SURFACE. THIS FORCING WILL ALSO BE AIDED BY PRETTY GOOD DIVERGENCE ALOFT AS THE AREA WILL BE UNDER THE RIGHT ENTRANCE REGION OF THE 100+ JET CORE AT 300 MB. THIS FORCING IS EXPECTED TO BE ENOUGH TO GENERATE ANOTHER LINE OF CONVECTION ALONG THE FRONT THIS AFTERNOON WITH THE BEST CHANCES FOR REDEVELOPMENT OVER THE EASTERN PORTIONS OF THE FORECAST AREA. WITH THE TIMING OF THE FRONT...THERE JUST MAY NOT BE ENOUGH TIME FOR RECOVERY TO OCCUR OVER THE WEST FOR MUCH TO DEVELOP. SEVERAL OF THE MODELS SUGGEST THE POTENTIAL FOR A NARROW CORRIDOR OF UPPER 60S TO AROUND 70 DEW POINTS ALONG THE FRONT WHICH COULD LEAD TO ML CAPES OF 2500 J/KG. THE BEST 0-6KM SHEAR DOES NOT LOOK LIKE IT WILL CATCH UP WITH THE INSTABILITY BECAUSE OF THE POSITIVE TILT OF THE LONG WAVE TROUGH...BUT UP TO 30 KNOTS OF 0-3KM SHEAR SHOULD RESIDE OVER THE INSTABILITY AXIS. THIS WILL PROVIDE ENOUGH SHEAR TO HELP ORGANIZE THE EXPECTED DEVELOPMENT ALONG THE FRONT ALONG WITH POSSIBLY SUPPORTING SOME SEVERE STORMS. THE 04.00Z NAM SUGGEST THERE WILL BE BETWEEN 1250-1500 J/KG OF DCAPE AVAILABLE ALONG WITH FAVORABLE TEMPS ALOFT FOR SOME HAIL PRODUCTION AS HEIGHTS LOWER WITH THE APPROACHING LONG WAVE TROUGH. SO IF THE STORMS DO BECOME SEVERE...DAMAGING WINDS AND LARGE HAIL WILL BE THE MAIN THREATS. HAVE LEFT THE RAIN CHANCES AT 60 PERCENT FOR THE AFTERNOON AS SOME CONCERN ON HOW FAST THE CLOUDS FOR THIS MORNING/S CONVECTION WILL CLEAR OUT. IF THESE HOLD ON LONGER THAN EXPECTED...THE INSTABILITY WILL NOT BUILD SETTING UP THE POTENTIAL FOR LESS CONVECTION TO OCCUR. ONCE THIS SYSTEM GOES THROUGH...A NORTHWEST FLOW ALOFT WILL BE IN PLACE OVER THE UPPER MIDWEST. THE NAM AND 03.12Z ECMWF ARE SUGGESTING A SHORT WAVE TROUGH IN THIS FLOW WILL COME ACROSS MONDAY NIGHT PUSHING A WEAK COLD FRONT THROUGH THE AREA. THIS FRONT LOOKS TO HAVE PRETTY DECENT FRONTOGENESIS WITH IT AND WILL CARRY A SMALL RAIN CHANCE ACROSS MUCH OF THE AREA. .LONG TERM...MONDAY NIGHT THROUGH FRIDAY 246 AM CDT SAT AUG 4 2012 THE NORTHWEST FLOW ALOFT WILL CONTINUE THROUGH THE PERIOD WITH THE NEXT SHORT WAVE TROUGH EXPECTED TO PASS OVER WEDNESDAY NIGHT AND THURSDAY. THIS SHOULD PUSH ANOTHER WEAK COLD FRONT THROUGH FOR A SMALL CHANCE OF RAIN. THE 04.00Z ECMWF SUGGESTS THIS SHORT WAVE TROUGH WILL THEN BE FOLLOWED BY AN UPPER LEVEL LOW DROPPING DOWN FROM THE HUDSONS BAY AREA. AS THIS MOVES ACROSS THE GREAT LAKES REGION SOME RAIN CHANCES WILL LINGER INTO THURSDAY NIGHT AND FRIDAY. && .AVIATION... 640 AM CDT SAT AUG 4 2012 WAVES OF CONVECTION PASSING THROUGH REGION AHEAD OF APPROACHING UPPER LOW HAVE BEEN A BIT PROBLEMATIC EARLY THIS MORNING. GENERALLY VFR CONDITIONS PREVAIL EXCEPT IN AREAS OF STRONGER CONVECTION SO TRIED TO TIME BETTER THUNDERSTORM WINDOWS IN SHORT TERM. OFF AND ON ACTIVITY LIKELY TO CONTINUE THROUGH MOST OF THE MORNING THOUGH AND AS UPPER LOW GETS EVEN CLOSER...ASSOCIATED COLD FRONT WILL BEGIN LIMITING STORM CHANCES...PUSHING THREAT EAST. MESOSCALE MODELS STILL HINT AT STRONGER STORMS REFORMING THIS AFTERNOON MAINLY SOUTH AND SOUTHEAST OF TAF SITES SO EXPECT GENERALLY DRYING TREND BY EVENING AS NORTHWEST WINDS TAKE OVER. SHOULD ALSO SEE CLEARING TONIGHT AS HIGH PRESSURE BUILDS IN BUT NORTHWEST WINDS BEHIND SYSTEM SHOULD KEEP THINGS MIXED AND PREVENT ANY FOG. && .ARX WATCHES/WARNINGS/ADVISORIES... 246 AM CDT SAT AUG 4 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM....04 AVIATION.....SHEA
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
330 AM CDT SAT AUG 4 2012 .TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM BIG CONCERN IS IMPACT OF CURRENT LINE OF CONVECTION ON THE EVOLUTION AND TIMING OF THUNDERSTORMS ACROSS FORECAST AREA LATER TODAY. SUB-SEVERE WIND REPORTS SINCE 12 MIDNIGHT HAVE INDICATED A WEAKENING TREND TO THE LINE...SUPPORTED BY REDUCED LIGHTNING ACTIVITY AND A SLIGHT WARMING OF CLOUD TOPS. LINE WILL REACH NW CWA BETWEEN 245 AM AND 3AM ON CURRENT PACE. HRRR AND RAP SUGGEST A RAPID WEAKENING OF CURRENT LINE AS IT MOVES AWAY FROM MAIN LOW-LEVEL JET AXIS AND INSTABILITY...THEN ALL MODELS SHOW A RE-FIRING OF CONVECTION ALONG SURFACE FRONT MID-LATE MORNING FROM WEST CENTRAL WI INTO FAR NE IOWA AS FRONTOGENETIC RESPONSE INCREASES AHEAD OF TROUGH. STILL FEEL BEST OPPORTUNITY FOR STRONG/SEVERE IN CWA DURING THE LATE AFTERNOON INTO THIS EVENING WITH ENHANCED FORCING AND 0 TO 6KM SHEAR INCREASING TO 30 TO 40 KTS AHEAD OF COLD FRONT AND POSITIVE-TILT 500 MB TROUGH AS IT SWINGS TO A MORE NEUTRAL POSITION WHILE CROSSING THE WESTERN GREAT LAKES TONIGHT. FORCING FOR ASCENT WILL BE AIDED BY UPPER LEVEL DIVERGENCE OF RRQ OF 100-110KT 250 MB JET MAX LIFTING ACROSS WRN GREAT LAKES REGION DURING THE LATE AFTERNOON AND EVENING. IF CLOUD DEBRIS DOESN/T OVERLY INHIBIT DAYTIME HEATING...SURFACE BASED CAPE OVER CWA RISES TO AROUND 1600 J/KG...COMPUTED LIFTED INDICES OF -5 TO -7...PRECIPITABLE WATER VALUES OF 1.8 TO 2 INCHES. FEEL CLOUDS WILL THIN ENOUGH AND WARM ADVECTION AHEAD OF FRONT WILL BRING HIGH TEMPERATURES IN THE LOW 90S INLAND...WITH SOUTHERLY WINDS TURNING INSHORE ENOUGH TO KEEP LAKESHORE AREAS IN THE MID-UPPER 80S. BUFKIT SOUNDINGS SHOW WELL MIXED BOUNDARY LAYER BY LATE AFTERNOON...WITH DRY SUB-CLOUD LAYER ENHANCING POTENTIAL FOR DAMAGING WINDS REFLECTED IN FORECAST DOWNDRAFT CAPE OF 1500 TO 2000 J/KG. PRECIPITATION ENDS IN THE EAST WITH TROUGH PASSAGE AROUND 06Z WITH DRIER AIR POURING IN ON NORTHWEST WINDS AS HIGH BUILDS IN FROM THE WEST. .SUNDAY AND MONDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH HIGH PRESSURE TO MOVE IN BEHIND THE COLD FRONT FOR SUNDAY AND MONDAY...BRINGING PLEASANT WEATHER TO SOUTHERN WISCONSIN. MAY SEE A FEW LINGERING CLOUDS NORTH SUNDAY AS THE UPPER TROUGH AXIS SWINGS THROUGH...WITH SUNNY SKIES ACROSS THE FORECAST AREA MONDAY. COOLER AIR BEHIND THE DEPARTING SYSTEM WILL RETURN TEMPERATURES TO NEAR NORMAL SUNDAY...WARMING BACK UP JUST A BIT MONDAY. .TUESDAY AND WEDNESDAY....FORECAST CONFIDENCE...MEDIUM MAY SEE A WEAK WAVE OR TWO SLIDE THROUGH TUESDAY AND WEDNESDAY...BUT OVERALL PRECIP CHANCES TOO LOW FOR POPS AT THIS TIME. WARM ADVECTION IS EXPECTED INTO THE AREA WITH UPPER RIDGE TO THE WEST...SO SHOULD SEE TEMPS RUN A FEW DEGREES ABOVE NORMAL. .THURSDAY AND FRIDAY...FORECAST CONFIDENCE...MEDIUM MODELS ADVERTISING A STRONGER WAVE FOR THURSDAY...SO WENT WITH CHANCE POPS MOST PLACES. LOOKS QUIETER FOR FRIDAY BEHIND THE SYSTEM. NO BIG CHANGE EXPECTED IN TEMPS THROUGH THE END OF THE WORK WEEK...WITH 80S CONTINUING. && .AVIATION/12Z TAFS/... WILL ADJUST TAFS FOR MVFR/IFR FOG IN THE NEAR TERM...THEN VFR UNTIL EXPECTED THUNDERSTORMS BRING MVFR CONDITIONS AND GUSTY WINDS. 000Z AND RAPID REFRESH MODELS SUPPORT KEEPING LATE AFTERNOON/EARLY EVENING TIMING FOR THUNDERSTORMS THAT IS IN CURRENT FORECAST. NORTHWEST WINDS KEEP BOUNDARY LAYER MIXED...WITH DRY AIR MOVING IN BEHIND COLD FRONT KEEPING OUT ANY CHANCE OF POST-FRONTAL LOW CLOUDS/FOG AT THIS TIME. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...REM SUNDAY THROUGH FRIDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
246 AM CDT SAT AUG 4 2012 .SHORT TERM...THROUGH MONDAY 246 AM CDT SAT AUG 4 2012 MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TODAY. SURFACE ANALYSIS THIS MORNING SHOWS AN AREA OF LOW PRESSURE OVER SOUTHEAST SASKATCHEWAN WITH A COLD FRONT EXTENDING SOUTH INTO EASTERN NEBRASKA. LOCAL AND REGIONAL RADARS SHOWING A LINE OF CONVECTION OUT AHEAD OF THE FRONT FROM NORTHWEST WISCONSIN INTO NORTHERN IOWA. ONGOING CONVECTION WAS FUELED BY A SHORT WAVE TROUGH THAT EJECTED OUT AHEAD OF THE MAIN LONG WAVE TROUGH AND BY LOW LEVEL WARM AIR ADVECTION AHEAD OF THE WAVE. ACTIVITY HAS BEEN SLOWLY WEAKENING AS IT MOVES EAST AS VWP WIND PROFILES SHOWS JUST A WEAK MOISTURE TRANSPORT SIGNAL OUT AHEAD OF THE LINE ALONG WITH LESS INSTABILITY TO THE EAST. THE 03.12Z AND 04.00Z HI-RES ARW HANDLED THIS SYSTEM EXTREMELY WELL AND SUGGESTS IT WILL CONTINUE TO DIMINISH BUT HOLD TOGETHER AS IT MOVES ACROSS THE FORECAST AREA...EXITING TO THE EAST BEFORE 12Z. ANOTHER AREA OF CONVECTION OVER SOUTHWEST MINNESOTA INTO NEBRASKA IS IN A MORE FAVORABLE POSITION TO MAINTAIN ITSELF THROUGH THE NIGHT. THERE IS A BETTER LOW LEVEL JET FEEDING INTO THIS AIDING THE ISENTROPIC UP GLIDE. AGAIN...THE HI- RES ARW HAS A GOOD HANDLE ON THIS AS DOES THE 04.08Z HRRR WHICH BRINGS THIS ACTIVITY INTO THE FORECAST AREA BEFORE IT DISSIPATES BY MID MORNING AS THE LOW LEVEL JET DECREASES AFTER SUNRISE. HAVE ACCOUNTED FOR THIS TREND WITH A BAND OF 60 PERCENT CHANCES FROM SOUTHWEST TO NORTHEAST THROUGH 15Z AND THEN BACKED DOWN TO A 30 TO 40 PERCENT CHANCE FOR THE REMAINDER OF THE MORNING. ATTENTION FOR THE AFTERNOON THEN TURNS TO THE LONG WAVE TROUGH TO THE WEST. THIS IS EXPECTED TO CONTINUE LIFTING NORTHEAST THROUGH THE DAY WITH THE UPPER LEVEL LOW GOING INTO WESTERN ONTARIO BY LATE AFTERNOON. THE LATEST SET OF MODELS NOW SUGGEST THE TROUGH AXIS WILL REMAIN POSITIVELY TILTED THROUGH THE DAY AND NOT TAKE ON MORE OF A NEUTRAL TILT UNTIL TONIGHT ONCE IT IS EAST OF THE AREA. THIS IS EXPECTED TO RESULT IN ABOUT 8 PVU/S OF VORTICITY ADVECTION IN THE 500-300 MB LAYER COMING ACROSS THIS AFTERNOON WITH AN INCREASE TONIGHT ONCE IT IS TO THE EAST OF THE AREA. IN THE LOW LEVELS...THE FRONT SHOULD COME THROUGH WITH WEAK TO MODERATE FRONTOGENESIS IN THE 1000-700 MB LAYER ALONG WITH UP TO 2 UBAR/S OF UP GLIDE ON THE 310K ISENTROPIC SURFACE. THIS FORCING WILL ALSO BE AIDED BY PRETTY GOOD DIVERGENCE ALOFT AS THE AREA WILL BE UNDER THE RIGHT ENTRANCE REGION OF THE 100+ JET CORE AT 300 MB. THIS FORCING IS EXPECTED TO BE ENOUGH TO GENERATE ANOTHER LINE OF CONVECTION ALONG THE FRONT THIS AFTERNOON WITH THE BEST CHANCES FOR REDEVELOPMENT OVER THE EASTERN PORTIONS OF THE FORECAST AREA. WITH THE TIMING OF THE FRONT...THERE JUST MAY NOT BE ENOUGH TIME FOR RECOVERY TO OCCUR OVER THE WEST FOR MUCH TO DEVELOP. SEVERAL OF THE MODELS SUGGEST THE POTENTIAL FOR A NARROW CORRIDOR OF UPPER 60S TO AROUND 70 DEW POINTS ALONG THE FRONT WHICH COULD LEAD TO ML CAPES OF 2500 J/KG. THE BEST 0-6KM SHEAR DOES NOT LOOK LIKE IT WILL CATCH UP WITH THE INSTABILITY BECAUSE OF THE POSITIVE TILT OF THE LONG WAVE TROUGH...BUT UP TO 30 KNOTS OF 0-3KM SHEAR SHOULD RESIDE OVER THE INSTABILITY AXIS. THIS WILL PROVIDE ENOUGH SHEAR TO HELP ORGANIZE THE EXPECTED DEVELOPMENT ALONG THE FRONT ALONG WITH POSSIBLY SUPPORTING SOME SEVERE STORMS. THE 04.00Z NAM SUGGEST THERE WILL BE BETWEEN 1250-1500 J/KG OF DCAPE AVAILABLE ALONG WITH FAVORABLE TEMPS ALOFT FOR SOME HAIL PRODUCTION AS HEIGHTS LOWER WITH THE APPROACHING LONG WAVE TROUGH. SO IF THE STORMS DO BECOME SEVERE...DAMAGING WINDS AND LARGE HAIL WILL BE THE MAIN THREATS. HAVE LEFT THE RAIN CHANCES AT 60 PERCENT FOR THE AFTERNOON AS SOME CONCERN ON HOW FAST THE CLOUDS FOR THIS MORNING/S CONVECTION WILL CLEAR OUT. IF THESE HOLD ON LONGER THAN EXPECTED...THE INSTABILITY WILL NOT BUILD SETTING UP THE POTENTIAL FOR LESS CONVECTION TO OCCUR. ONCE THIS SYSTEM GOES THROUGH...A NORTHWEST FLOW ALOFT WILL BE IN PLACE OVER THE UPPER MIDWEST. THE NAM AND 03.12Z ECMWF ARE SUGGESTING A SHORT WAVE TROUGH IN THIS FLOW WILL COME ACROSS MONDAY NIGHT PUSHING A WEAK COLD FRONT THROUGH THE AREA. THIS FRONT LOOKS TO HAVE PRETTY DECENT FRONTOGENESIS WITH IT AND WILL CARRY A SMALL RAIN CHANCE ACROSS MUCH OF THE AREA. .LONG TERM...MONDAY NIGHT THROUGH FRIDAY 246 AM CDT SAT AUG 4 2012 THE NORTHWEST FLOW ALOFT WILL CONTINUE THROUGH THE PERIOD WITH THE NEXT SHORT WAVE TROUGH EXPECTED TO PASS OVER WEDNESDAY NIGHT AND THURSDAY. THIS SHOULD PUSH ANOTHER WEAK COLD FRONT THROUGH FOR A SMALL CHANCE OF RAIN. THE 04.00Z ECMWF SUGGESTS THIS SHORT WAVE TROUGH WILL THEN BE FOLLOWED BY AN UPPER LEVEL LOW DROPPING DOWN FROM THE HUDSONS BAY AREA. AS THIS MOVES ACROSS THE GREAT LAKES REGION SOME RAIN CHANCES WILL LINGER INTO THURSDAY NIGHT AND FRIDAY. && .AVIATION... 1120 PM CDT FRI AUG 3 2012 LINE OF CONVECTION CONTINUES TO TRACK EAST ACROSS MN LATE THIS EVENING...AND THIS WILL IMPACT KRST AND KLSE. AT ITS CURRENT PACE IT WILL REACH KRST BY 0530Z AND KLSE NEAR 07Z. THE STORMS ARE PACKING QUITE A BIT OF WIND...EXPECT NORTHWEST GUSTS UPWARDS OF 40 TO 50 KTS AT KRST...CLOSER TO 40 KTS AT KLSE. THE LINE SHOULD SWEEP EAST OF KRST BY 09Z AND KLSE BY 11Z. MORE SHRA/TS WILL MOVE IN LATER SAT MORNING...CONTINUING INTO THE AFTERNOON...AS A COLD FRONT DRIVES EAST ACROSS THE REGION. NAM12 BRINGS IT ACROSS KRST AROUND 16Z AND KLSE NEAR 18Z. SOME OF THESE STORMS COULD ALSO BECOME STRONG TO SEVERE...WITH WIND AND HAIL THE THREATS. THE GREATER THREAT WILL LIKELY BE AT KLSE WHERE TIMING WILL FAVOR MORE INSTABILITY...AND THUS THE POTENTIAL FOR STRONGER STORMS. EXPECT MOST OF THE ACTIVITY TO EXIT EAST BETWEEN 21-00Z...WITH A CLEARING TREND IN THE EVENING AS HIGH PRESSURE OVER THE PLAINS STARTS TO INFLUENCE THE LOCAL AREA. PRESSURE GRADIENT STAYS RELATIVELY TIGHT THOUGH...SO THERE MIGHT NOT BE A LOT OF DROP OFF IN WINDS SAT NIGHT. && .ARX WATCHES/WARNINGS/ADVISORIES... 246 AM CDT SAT AUG 4 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
551 AM EDT MON AUG 6 2012 .SYNOPSIS... A FRONTAL BOUNDARY WILL SLIDE SLOWLY SOUTHEASTWARD EARLY TODAY. HIGH PRESSURE WILL THEN BUILD INTO THE AREA FROM THE MIDWEST AND PROVIDE A DRY START TO THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... A QUICK EARLY MORNING UPDATE HAS BEEN ISSUED TO SPEED UP CLEARING THIS MORNING AS DRIER DEW POINTS ADVECT INTO WESTERN PA FROM OHIO. IN ADDITION, POP GRIDS HAVE BEEN REDUCED TO SCHC ACROSS THE WV/MD RIDGES FOR THIS MORNING INTO THE EARLY AFTERNOON. THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A WEAK VORT MAX ADVECTING SLOWLY SOUTHEASTWARD FROM EASTERN OHIO INTO NORTH-CENTRAL WV. AT THE SURFACE, A FRONTAL BOUNDARY, MOST EVIDENT BY THE DEW POINT GRADIENT, EXTENDS FROM ZANESVILLE TO BUTLER TO DU BOIS. WITH TDS STILL IN THE UPPER 60S AND ABUNDANT LOW-LEVEL MOISTURE FROM RECENT RAINFALL, PATCHY FOG HAS DEVELOPED SOUTH AND EAST OF THE PITTSBURGH METRO. THE BACK EDGE OF THE CLOUD DECK IS REACHING WESTERN PA WITH CLEARING IN OHIO. TODAY AND TONIGHT...THE FRONTAL BOUNDARY WILL SLOWLY SEEP SOUTHEASTWARD AS A DEEP LAYER OF DRY AIR ADVECTS INTO THE AREA WITH THE HIGH SHIFTING EASTWARD INTO THE OHIO VALLEY. THIS WILL ALLOW FOR ANY LINGERING CONVECTION TO PUSH SOUTHEAST OF THE WV/MD RIDGES. SOME CLEARING WILL OCCUR FROM THE WEST INITIALLY, FOLLOWED BY SCATTERED CUMULUS DEVELOPING DURING THE LATE MORNING. THE MOST CLOUD COVERAGE IS ANTICIPATED EARLY FOR AREAS SOUTH OF THE BOUNDARY. A GENERAL CLEARING TREND IS EXPECTED LATER THIS AFTERNOON INTO THE EVENING. HIGHS TODAY SIDE WITH THE COOLER MAV EVERYWHERE EXCEPT ACROSS NORTH-CENTRAL WV WHERE THE BOUNDARY WILL BE SLOWER TO CLEAR. WITH CLEAR SKIES AND NEAR CALM WINDS OVERNIGHT, THIS WILL ALLOW FOR RADIATIONAL COOLING TONIGHT. LOWS ARE CLOSER TO THE COOLER MAV GUIDANCE, RANGING FROM NEAR 50 ACROSS THE I-80 CORRIDOR TO THE UPPER 50S ACROSS NORTH-CENTRAL WV. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... THERE IS NAM/GFS AGREEMENT THAT THE DEEP LAYER OF DRY AIR WILL REMAIN ACROSS THE AREA AS THE SURFACE HIGH SHIFTS EAST OF THE AREA ON TUESDAY. WITH THIS IN MIND, ABUNDANT SUNSHINE IS ANTICIPATED. 850MB TEMPS WARMING TO AROUND 16C ON TUESDAY ALONG WITH SUNSHINE WILL ALLOW FOR HIGHS TO BE AROUND 5 DEGREES ABOVE SEASONAL NORMALS. FORECAST UNCERTAINTY BEGINS WEDNESDAY AS THE NEXT FRONTAL BOUNDARY APPROACHES FROM THE NORTHWEST AND SOUTHWESTERLY WINDS INCREASE LOW-LEVEL MOISTURE ACROSS THE AREA LATE IN THE DAY. WITH LITTLE FORCING, INSTABILITY, AND SHEAR, FORECAST IS CLOSEST TO THE COOLER GFS AND CONSISTS OF SCHC POPS. TEMPS WILL CONTINUE TO BE AROUND 5 DEGREES ABOVE NORMAL FOR HIGHS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... NO MAJOR CHANGES TO EXTENDED FORECAST CONSIDERING FOCUS WAS ON POSSIBLE SEVERE WEATHER FOR TODAY. MODELS STILL NOT SHOWING MUCH AGREEMENT ON FRONTAL PASSAGE FOR END OF THE WORK WEEK. 12Z GFS BRINGS FRONT THROUGH ON THURSDAY...00Z ECMWF BRINGS FRONT THROUGH ON THURSDAY/FRIDAY...AND 00Z GEFS BRINGS FRONT THROUGH ON FRIDAY. AT THIS POINT...HAVE STUCK CLOSE TO PREVIOUS FORECAST...WHICH BRINGS FRONT THROUGH ON FRIDAY. TEMPERATURES WILL TURN COOLER FOR THE WEEKEND...WITH HIGHS DROPPING INTO THE 70S. AN ISOLATED SHOWER CANNOT BE RULED OUT OVER THE WEEKEND WITH RELATIVELY COOLER 850MB AIR (10-12C) PASSING OVER A WARM LAKE ERIE (23-25C). && .AVIATION /10Z MONDAY THROUGH FRIDAY/... STRATUS...AND FOG WHEREVER A BREAK IN THE STRATUS OCCURS...WILL PLAGUE MOST OF THE TERMINALS THROUGH THE NIGHT. LOW LEVEL DRYING HAS BEEN SLOW TO WORK INTO THE AREA BEHIND THE FRONT AS OVERNIGHT INVERSIONS AND A LACK OF MIXING HAS REALLY STARTED TO CONTROL THE LOW LEVELS. AS SUCH...DEWPOINTS REMAIN IN THE 66-72F DEGREE RANGE AT ALL TERMINALS...WHILE JUST A BIT TO THE NW FROM KDAY TO KCAK...THEY ARE RUNNING IN THE UPPER 50S. WITH A WEAK ISALLOBARIC FLOW LIKELY OVERNIGHT...ONLY KFKL AND KZZV HAVE A DECENT SHOT AT BREAKING OUT...OTHERWISE ALL SITES SHOULD REMAIN IN THE IFR OR LOWER FOG/STRATUS THROUGH MORNING. AFTER SUNRISE...LOW LEVEL DRYING WILL TAKE PLACE RAPIDLY FROM N TO S...WITH JUST A FEW CUMULUS LIKELY BY THE AFTERNOON. FRIES OUTLOOK...MONDAY NIGHT THROUGH FRIDAY... VFR CONDITIONS WILL MOSTLY PREVAIL THROUGH WEDNESDAY AS HIGH PRESSURE CROSSES THE OHIO VALLEY. LOW PRESSURE MOVING INTO THE GREAT LAKES WILL RETURN THE CHANCE OF THUNDERSTORMS AND RESTRICTIONS BY THE END OF THE WEEK. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
417 AM EDT MON AUG 6 2012 .SYNOPSIS... A FRONTAL BOUNDARY WILL SLIDE SLOWLY SOUTHWARD EARLY TODAY. HIGH PRESSURE WILL THEN BUILD INTO THE AREA FROM THE MIDWEST AND PROVIDE A DRY START TO THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A WEAK VORT MAX ADVECTING SLOWLY SOUTHEASTWARD FROM EASTERN OHIO INTO NORTH-CENTRAL WV. AT THE SURFACE, A FRONTAL BOUNDARY, MOST EVIDENT BY THE DEW POINT GRADIENT, EXTENDS FROM ALONG A LINE JUST NORTH OF NEW PHILADELPHIA TO NEW CASTLE TO DU BOIS. SHOWERS THAT HAVE BEEN CONFINED TO LOCATIONS SOUTH OF THE BOUNDARY ARE QUICKLY COMING TO AN END THIS MORNING. WITH TDS STILL IN THE LOWER 70S AND ABUNDANT LOW-LEVEL MOISTURE FROM RECENT RAINFALL, PATCHY FOG HAS DEVELOPED ACROSS THE AREA. IN ADDITION, FURTHER UPSTREAM SKIES ARE CLEAR, AS A SURFACE HIGH IS CENTERED ACROSS THE MIDWEST. TODAY AND TONIGHT...THE FRONTAL BOUNDARY WILL SLOWLY SEEP SOUTHWARD AS A DEEP LAYER OF DRY AIR ADVECTS INTO THE AREA WITH THE HIGH SHIFTING EASTWARD INTO THE OHIO VALLEY. THIS WILL ALLOW FOR ANY LINGERING SHOWERS AND THUNDERSTORMS TO PUSH SOUTHEAST OF THE WV/MD RIDGES. SOME CLEARING WILL OCCUR FROM THE WEST INITIALLY, FOLLOWED BY SCATTERED CUMULUS DEVELOPING DURING THE LATE MORNING. THE MOST CLOUD COVERAGE IS ANTICIPATED EARLY FOR AREAS SOUTH OF THE BOUNDARY. A GENERALLY CLEARING TREND IS EXPECTED LATER THIS AFTERNOON INTO THE EVENING. HIGHS TODAY SIDE WITH THE COOLER MAV EVERYWHERE EXCEPT ACROSS NORTH-CENTRAL WV, WHERE THE BOUNDARY WILL BE SLOW TO CLEAR. THE SKIES WILL CLEAR LATER TODAY AND TONIGHT AS THE HIGH BECOMES CENTERED OVER THE UPPER OHIO VALLEY. WITH CLEAR SKIES AND NEAR CALM WINDS, THIS WILL ALLOW FOR RADIATIONAL COOLING TONIGHT. LOWS ARE CLOSER TO THE COOLER MAV GUIDANCE, RANGING FROM THE LOWER 50S ACROSS THE I-80 CORRIDOR TO THE UPPER 50S ACROSS NORTH-CENTRAL WV. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... THERE IS NAM/GFS AGREEMENT THAT THE DEEP LAYER OF DRY AIR WILL REMAIN ACROSS THE AREA AS THE SURFACE HIGH SHIFTS EAST OF THE AREA ON TUESDAY. WITH THIS IN MIND, ABUNDANT SUNSHINE IS ANTICIPATED. 850MB TEMPS WARMING TO AROUND 16C ON TUESDAY ALONG WITH SUNSHINE WILL ALLOW FOR HIGHS TO BE AROUND 5 DEGREES ABOVE SEASONAL NORMALS. FORECAST UNCERTAINTY BEGINS WEDNESDAY AS THE NEXT FRONTAL BOUNDARY APPROACHES FROM THE NORTHWEST AND SOUTHWESTERLY WINDS INCREASE LOW-LEVEL MOISTURE ACROSS THE AREA LATE IN THE DAY. WITH LITTLE FORCING, INSTABILITY, AND SHEAR, FORECAST IS CLOSEST TO THE COOLER GFS AND CONSISTS OF SCHC POPS. TEMPS WILL CONTINUE TO BE AROUND 5 DEGREES ABOVE NORMAL FOR HIGHS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... NO MAJOR CHANGES TO EXTENDED FORECAST CONSIDERING FOCUS WAS ON POSSIBLE SEVERE WEATHER FOR TODAY. MODELS STILL NOT SHOWING MUCH AGREEMENT ON FRONTAL PASSAGE FOR END OF THE WORK WEEK. 12Z GFS BRINGS FRONT THROUGH ON THURSDAY...00Z ECMWF BRINGS FRONT THROUGH ON THURSDAY/FRIDAY...AND 00Z GEFS BRINGS FRONT THROUGH ON FRIDAY. AT THIS POINT...HAVE STUCK CLOSE TO PREVIOUS FORECAST...WHICH BRINGS FRONT THROUGH ON FRIDAY. TEMPERATURES WILL TURN COOLER FOR THE WEEKEND...WITH HIGHS DROPPING INTO THE 70S. AN ISOLATED SHOWER CANNOT BE RULED OUT OVER THE WEEKEND WITH RELATIVELY COOLER 850MB AIR (10-12C) PASSING OVER A WARM LAKE ERIE (23-25C). && .AVIATION /08Z MONDAY THROUGH FRIDAY/... STRATUS...AND FOG WHEREVER A BREAK IN THE STRATUS OCCURS...WILL PLAGUE MOST OF THE TERMINALS THROUGH THE NIGHT. LOW LEVEL DRYING HAS BEEN SLOW TO WORK INTO THE AREA BEHIND THE FRONT AS OVERNIGHT INVERSIONS AND A LACK OF MIXING HAS REALLY STARTED TO CONTROL THE LOW LEVELS. AS SUCH...DEWPOINTS REMAIN IN THE 66-72F DEGREE RANGE AT ALL TERMINALS...WHILE JUST A BIT TO THE NW FROM KDAY TO KCAK...THEY ARE RUNNING IN THE UPPER 50S. WITH A WEAK ISALLOBARIC FLOW LIKELY OVERNIGHT...ONLY KFKL AND KZZV HAVE A DECENT SHOT AT BREAKING OUT...OTHERWISE ALL SITES SHOULD REMAIN IN THE IFR OR LOWER FOG/STRATUS THROUGH MORNING. AFTER SUNRISE...LOW LEVEL DRYING WILL TAKE PLACE RAPIDLY FROM N TO S...WITH JUST A FEW CUMULUS LIKELY BY THE AFTERNOON. FRIES OUTLOOK...MONDAY NIGHT THROUGH FRIDAY... VFR CONDITIONS WILL MOSTLY PREVAIL THROUGH WEDNESDAY AS HIGH PRESSURE CROSSES THE OHIO VALLEY. LOW PRESSURE MOVING INTO THE GREAT LAKES WILL RETURN THE CHANCE OF THUNDERSTORMS AND RESTRICTIONS BY THE END OF THE WEEK. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
221 AM EDT MON AUG 6 2012 .SYNOPSIS... A FRONTAL BOUNDARY WILL SLIDE SLOWLY SOUTHWARD EARLY TODAY, WITH SHOWERS COMING TO AN END THIS MORNING. HIGH PRESSURE WILL THEN BUILD INTO THE AREA FROM THE MIDWEST AND PROVIDE A DRY START TO THE WEEK. && .NEAR TERM /THROUGH TODAY/... THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A WEAK VORT MAX ADVECTING SLOWLY SOUTHEASTWARD FROM SW PA INTO NORTH-CENTRAL WV AND WESTERN MD. AT THE SURFACE, A FRONTAL BOUNDARY, MOST EVIDENT BY THE DEW POINT GRADIENT, EXTENDS FROM ALONG A LINE JUST NORTH OF NEW PHILADELPHIA TO NEW CASTLE TO DUBOIS. REMAINING SHOWERS SOUTH OF THE BOUNDARY ARE CONFINED MOSTLY TO NORTH-CENTRAL WV. WITH TDS STILL IN THE LOWER 70S AND ABUNDANT LOW- LEVEL MOISTURE FROM RECENT RAINFALL, PATCHY FOG HAS BEGUN TO DEVELOP ACROSS THE AREA. IN ADDITION, FURTHER UPSTREAM SKIES ARE CLEAR, AS A SURFACE HIGH IS CENTERED ACROSS THE MIDWEST. TODAY AND TONIGHT...THE FRONTAL BOUNDARY WILL SLOWLY SEEP SOUTHWARD AS A DEEP LAYER OF DRY AIR ADVECTS INTO THE AREA WITH THE HIGH SHIFTING EASTWARD INTO THE OHIO VALLEY. THIS ALLOW FOR SHOWERS AND THUNDERSTORMS ACROSS TO PUSH SOUTHEAST OF THE WV/MD RIDGES. CUMULUS WILL DEVELOP TODAY, WITH THE MOST CLOUD COVERAGE EARLY FOR AREAS SOUTH OF THE BOUNDARY. HIGHS TODAY SIDE WITH THE COOLER MAV EVERYWHERE EXCEPT ACROSS NORTH-CENTRAL WV, WHERE THE BOUNDARY WILL BE SLOW TO CLEAR. THE SKIES WILL CLEAR LATER TODAY AND TONIGHT AS THE HIGH BECOMES CENTERED OVER THE UPPER OHIO VALLEY. WITH CLEAR SKIES AND NEAR CALM WINDS, THIS WILL ALLOW FOR RADIATIONAL COOLING TONIGHT. LOWS ARE CLOSER TO THE COOLER MAV GUIDANCE, RANGING FROM THE LOWER 50S ACROSS THE I-80 CORRIDOR TO THE UPPER 50S ACROSS NORTH-CENTRAL WV. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY/... HIGH PRESSURE WILL REMAIN THE MAIN STORY THROUGH MOST OF WEDNESDAY. WITH STRONG SUBSIDENCE AND RADIATIVE COOLING...TEMPERATURES OVERNIGHT MONDAY AND TUESDAY COULD BE BELOW NORMAL AND INTO THE 50`S. THIS IS CLOSEST TO MAV GUIDANCE THROUGH THE PERIOD. MODELS ARE IN DISAGREEMENT ON THE APPROACH OF THE NEXT SYSTEM WITH THE NAM BRINGING A FRONTAL BOUNDARY/SHORTWAVE ACROSS THE REGION LATE WEDNESDAY. THIS IS QUICKER THAN THE GFS. AT THIS POINT...WILL JUST HEDGE WITH SLIGHT CHANCE POPS WITH THE TIMING INCONSISTENCIES. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... NO MAJOR CHANGES TO EXTENDED FORECAST CONSIDERING FOCUS WAS ON POSSIBLE SEVERE WEATHER FOR TODAY. MODELS STILL NOT SHOWING MUCH AGREEMENT ON FRONTAL PASSAGE FOR END OF THE WORK WEEK. 12Z GFS BRINGS FRONT THROUGH ON THURSDAY...00Z ECMWF BRINGS FRONT THROUGH ON THURSDAY/FRIDAY...AND 00Z GEFS BRINGS FRONT THROUGH ON FRIDAY. AT THIS POINT...HAVE STUCK CLOSE TO PREVIOUS FORECAST...WHICH BRINGS FRONT THROUGH ON FRIDAY. TEMPERATURES WILL TURN COOLER FOR THE WEEKEND...WITH HIGHS DROPPING INTO THE 70S. AN ISOLATED SHOWER CANNOT BE RULED OUT OVER THE WEEKEND WITH RELATIVELY COOLER 850MB AIR (10-12C) PASSING OVER A WARM LAKE ERIE (23-25C). && .AVIATION /06Z MONDAY THROUGH FRIDAY/... STRATUS...AND FOG WHEREVER A BREAK IN THE STRATUS OCCURS...WILL PLAGUE MOST OF THE TERMINALS THROUGH THE NIGHT. LOW LEVEL DRYING HAS BEEN SLOW TO WORK INTO THE AREA BEHIND THE FRONT AS OVERNIGHT INVERSIONS AND A LACK OF MIXING HAS REALLY STARTED TO CONTROL THE LOW LEVELS. AS SUCH...DEWPOINTS REMAIN IN THE 66-72F DEGREE RANGE AT ALL TERMINALS...WHILE JUST A BIT TO THE NW FROM KDAY TO KCAK...THEY ARE RUNNING IN THE UPPER 50S. WITH A WEAK ISALLOBARIC FLOW LIKELY OVERNIGHT...ONLY KFKL AND KZZV HAVE A DECENT SHOT AT BREAKING OUT...OTHERWISE ALL SITES SHOULD REMAIN IN THE IFR OR LOWER FOG/STRATUS THROUGH MORNING. AFTER SUNRISE...LOW LEVEL DRYING WILL TAKE PLACE RAPIDLY FROM N TO S...WITH JUST A FEW CUMULUS LIKELY BY THE AFTERNOON. FRIES OUTLOOK...MONDAY NIGHT THROUGH FRIDAY... VFR CONDITIONS WILL MOSTLY PREVAIL THROUGH WEDNESDAY AS HIGH PRESSURE CROSSES THE OHIO VALLEY. LOW PRESSURE MOVING INTO THE GREAT LAKES WILL RETURN THE CHANCE OF THUNDERSTORMS AND RESTRICTIONS BY THE END OF THE WEEK. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1200 AM MDT MON AUG 6 2012 .AVIATION... 06Z TAF CYCLE SOME LINGERING SHOWERS AND THUNDERSTORMS MAINLY NEAR AND N OF INTERSTATE 40 FOR A FEW HOURS PAST MIDNIGHT BEFORE MOST OF THEM DIMINISH. MOST OF THE ACTIVITY WILL NOT BE STRONG ENOUGH TO CREATE MAJOR AVIATION HAZARDS...THOUGH SOME BRIEF MVFR CONDITIONS POSSIBLE WITH THE STRONGEST ACTIVITY IN MAINLY CENTRAL AND PERHAPS NE NM. ALSO A FEW POCKETS OF MVFR OR VERY LOCALLY IFR CIGS AND FOG IN WETTER NORTHERN MT VALLEYS AND IMMEDIATE E SLOPES OF SANGRE DE CRISTOS...ESPECIALLY AFTER 09Z UNTIL MID MORN MON. WHILE SOME SHRA AND TSRA LIKELY TO DEVELOP IN ISOLATED TO SCT FASHION MAINLY ACROSS N AND W CENTRAL MT REGIONS AFTER 19Z...COVERAGE AND INTENSITY SHOULD OVERALL BE A LITTLE LESS THAN TODAY. VERY LOCALIZED AND BRIEF MVFR CIGS STILL POSS WITH STRONGEST STORMS...BUT LESS THAN ON SUN. 43 && .PREV DISCUSSION...1024 PM MDT SUN AUG 5 2012... FIRST ORDER OF BUSINESS WAS TO EXPIRE THE FLASH FLOOD WATCH AT 10 PM. ABX RADAR INDICATED HANDS DOWN OUR BEST STORM CORE PRECIP TOTALS ACROSS THE WEST TODAY. A FEW AREAS MAY HAVE PICKED UP 4 TO 6 INCHES OF RAIN. ONE SUCH AREA WAS THOREAU WHERE SIGNIFICANT FLASH FLOODING HAS BEEN REPORTED TODAY. NOW THE FOCUS IS WHERE ADJUST HIGHEST POPS. CURRENTLY THE RADAR AND SATELLITE TRENDS FOCUS THE BEST COVERAGE OVER THE NORTHERN MTS AND STILL SOMEWHAT ALONG THE CONT DVD. THE 01Z HRRR AND 03Z RUC HANDLE THE CURRENT PRECIP WELL SO HAVE GONE IN THIS DIRECTION ONCE AGAIN TONIGHT. THEREFORE EXPECTING CURRENT NMRS COVERAGE ACROSS THE NORTH TO MOVE SLOWLY ESE INTO THE JEMEZ AND SOUTHERN SANGRES AND THE NE HIGHLANDS. PLACED SCATTERED COVERAGE THERE WITH ISOLD AT BEST FOR THE REMAINDER OF THE AREA. GUYER .PREV DISCUSSION...610 PM MDT SUN AUG 5 2012... .AVIATION... 00Z TAF CYCLE ANOTHER FAIRLY ACTIVE CONVECTIVE DAY WAS REALIZED TODAY...BUT MAINLY JUST ACROSS THE NW THIRD OR SO OF THE STATE. THROUGH THIS EVE EXPECT SCT TO LOCALLY NUMEROUS SHRA AND TSRA AGAIN MOSTLY WEST AND NORTH NM. STRONGEST STORMS WILL LIKELY ALSO REMAIN MAINLY N AND W WITH LOCALIZED AND RELATIVELY SHORT LIVED MVFR CIGS AS WELL AS ISOLATED INSTANCES OF SMALL HAIL ASSOCIATED WITH STRONGER TSRA. TSRA MENTIONED ONLY IN SAF...LVS AND FMN TO ACCOUNT FOR BEST CHANCE LOCALES FOR TSRA. OTHERWISE IN AREAS ALREADY WORKED OVER IN WEST OR OTHERWISE TOO UNLIKELY TO PICK UP A TSRA IN CENTRAL AND E NM EITHER VCSH MENTIONED OR NOTHING AT ALL.. MOST IF NOT ALL TSRA SHOULD DISSIPATE BY OR WITHIN A COUPLE HOURS OF MIDNIGHT. WHILE SOME SHRA AND TSRA LIKELY TO DEVELOP MON MAINLY AFTER 19Z...COVERAGE AND INTENSITY SHOULD OVERALL BE A LITTLE LESS THAN TODAY. 43 .PREV DISCUSSION...315 PM MDT SUN AUG 5 2012... AS EXPECTED...SOMEWHAT OF A SLOW START TO THE SHOWER AND THUNDERSTORM DEVELOPMENT THIS AFTERNOON. PRECIPITABLE WATER VALUES IN THE FLASH FLOOD WATCH AREA REMAIN ABOUT 120-150 PERCENT OF NORMAL SO NO CHANGES TO THE ONGOING WATCH. LOW LEVEL GULF MOISTURE COMBINING WITH MID LEVEL MONSOON MOISTURE PLUME TO GET PWAT VALUES UP THIS HIGH. STORMS FIRING OVER THE WEST-CENTRAL MTNS ARE MOVING NORTH AROUND 15 KTS BUT TRAINING OF SHOWERS AND STORMS OVER THE SAME AREA/DRAINAGE REMAINS THE MAIN CONCERN. DOPPLER RADAR ESTIMATING OVER 2 INCHES OF RAIN HAVE FALLEN FROM ONE CELL OR CELLS TRAINING OVER THOREAU IN THE PAST HOUR AND A HALF. ELSEWHERE...STORMS ARE DEVELOPING OVER THE NORTHERN MOUNTAINS AND SUSPECT THAT STORMS WILL BEGIN FIRING OVER OTHER MOUNTAIN LOCATIONS SHORTLY...AS MORE SURFACE HEATING ALLOWS UPDRAFTS TO PUNCH THROUGH THE SUBSIDENCE INVERSION AROUND 14K FEET AGL. MODELS ARE IN VERY GOOD TO EXCELLENT AGREEMENT FOR MONDAY...SLIDING THE CENTER OF THE UPPER LEVEL HIGH OVER NORTHWEST NM. STEERING LEVEL FLOW GRADUALLY BECOMES NORTH/NORTHWESTERLY OVER THE NORTH AND NORTHEAST TO EASTERLY OVER THE SOUTHWEST MOUNTAINS. RESIDUAL MOISTURE WILL COMBINE WITH THE ELEVATED HEAT SOURCES/MOUNTAINS TO GET SCATTERED SHOWERS AND THUNDERSTORMS GOING MONDAY AFTERNOON. HIGH RESOLUTION MODELS INDICATING THAT STORMS MOVING SOUTH FROM THE JEMEZ MOUNTAINS COULD BRING A ROUND OF THUNDERSTORMS TO BERNALILLO AND THE ALBUQUERQUE METRO AREA EARLY MONDAY EVENING. AND WITH STORM MOTION BECOMING NORTHWESTERLY MONDAY LATE AFTERNOON AND EVENING...SHOWERS AND STORMS WILL MOVE OFF THE SANGRE DE CRISTOS OUT ONTO THE NORTHEAST HIGHLANDS AND PLAINS. TUESDAY LOOKS VERY SIMILAR TO MONDAY WITH ONE EXCEPTION. AS THE UPPER HIGH CENTER SHIFTS FAR ENOUGH WESTWARD...NELY FLOW AT ALL LEVELS DEVELOPS AND BRINGS GULF MOISTURE TO THE NERN PLAINS AND CENTRAL HIGHLANDS TUESDAY AFTERNOON AND EVENING. THE MOIST NELY FLOW COMBINES WITH A WEAK WAVE TRANSLATING AROUND THE UPPER HIGH TO BRING HIGHER STORM CHANCES FROM THE CENTRAL MOUNTAINS EWD TUESDAY AFTERNOON AND EVENING. SIMILAR UPPER LEVEL AND SURFACE PATTERN CONTINUES INTO WEDNESDAY. DRIER MID AND UPPER LEVEL AIR BEGINS TO FILTER INTO CENTRAL AND SRN NM THURSDAY...WITH THE BEST THUNDERSTORM CHANCES OVER THE NRN MOUNTAINS. FRIDAY LOOKS...AT THIS POINT...LIKE THE DOWN DAY FOR THUNDERSTORMS THIS WEEK...OUTSIDE OF THE NRN AND WRN MOUNTAINS BUT WITH A NELY STEERING LEVEL FLOW IN PLACE...CANNOT RULE OUT SLIGHT CHANCES/ISOLATED STORMS FOR THE CENTRAL VALLEYS AS STORMS MOVE SOUTHWESTWARD. EXCELLENT AGREEMENT IN THE MEDIUM RANGE OPERATIONAL MODELS EXISTS FOR NEXT WEEKEND. UPPER HIGH REMAINS FAR ENOUGH NORTHWEST OF THE STATE FOR OCCASIONAL SHORT-WAVES/DISTURBANCES TO ROTATE AROUND THE HIGH CENTER AND INITIATE A NORTHEAST TO ELY SURFACE FLOW OVER THE REGION...RECHARGING SFC MOISTURE. THIS NW FLOW ALOFT IS QUITE THE FAVORABLE PATTERN FOR THE NORTHEAST AND EAST CENTRAL PLAINS. LONG RANGE FORECASTS GET QUITE INTERESTING. LATEST ECMWF FORECASTS A MAJOR BLOCKING PATTERN (OMEGA BLOCK) OVER THE GULF OF ALASKA...FORCING A LARGE AND UNSEASONABLY DEEP CLOSED UPPER LEVEL LOW OVER THE PACNW. THIS PATTERN WOULD FORCE THE UPPER HIGH BACK OVER THE SRN PLAINS STATES AND POSSIBLY OPEN THE DOOR FOR A DEEP SOUTHERLY FETCH OF SUBTROPICAL/TROPICAL MOISTURE INTO THE STATE. WE SHALL SEE. 33 .FIRE WEATHER... SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE QUITE NUMEROUS GOING INTO THE EVENING...ESPECIALLY ACROSS WESTERN AND NORTHERN PARTS OF NEW MEXICO. THIS BOOST IN STORM COVERAGE AND THE RELATIVELY LARGE FOOTPRINT OF WETTING RAINS RECEIVED YESTERDAY SHOULD PRECLUDE ANY FIRE WEATHER CONCERNS THROUGH THE NEAR TERM. BACK DOOR FRONT ADVANCED TOWARD ARIZONA...AND SHOULD CONTINUE TO PROVIDE SOME UPSLOPE TO AID IN THUNDERSTORM DEVELOPMENT ALONG AND NEAR THE CONTINENTAL DIVIDE. TEMPERATURES HAVE ALSO FALLEN BACK TO MORE REASONABLE VALUES AND CLOSER TO SEASONAL AVERAGES...ESPECIALLY IN THE EASTERN PLAINS. THIS ALONG WITH INCREASED CLOUD COVER AND ANTECEDENT RAIN CONDITIONS HAS KEPT RELATIVE HUMIDITY AT OR ABOVE 30 PERCENT IN THE FORECAST AREA...AND ANY GAP/CANYON WINDS HAVE DIMINISHED. GOOD TO EXCELLENT RH RECOVERY CAN BE EXPECTED TONIGHT AND INTO EARLY MONDAY MORNING. AS HIGH PRESSURE ALOFT REGAINS SOME SYMMETRY OVER THE FOUR CORNERS...IT WILL STEER FEWER STORMS INTO THE NORTHERN AND WESTERN MOUNTAINS OF NEW MEXICO ON MONDAY. ONCE THE HIGH NUDGES NORTHWESTWARD INTO TUESDAY...ANOTHER BACK DOOR FRONT WILL SLIDE INTO THE NORTHEASTERN PLAINS OF NEW MEXICO. AT THIS POINT...THE DIRECTIONAL SHIFT IN THE WINDS APPEARS TO BE A PRIMARY IMPACT AS NO MAJOR INCREASE IN DEWPOINTS IS ANTICIPATED. ANY UPTICK IN STORM COVERAGE IN THE NORTHEAST ON TUESDAY WOULD BE FAIRLY SUBTLE. FROM MID WEEK AND THROUGH THE EXTENDED FORECAST PERIOD VERY LITTLE MOVEMENT OF THE UPPER LEVEL HIGH IS FORESEEN. THIS WILL LIKELY DRIVE STORMS MOSTLY TO THE NORTHERN AND WESTERN MOUNTAINS OF NEW MEXICO WITH LESS THAN AVERAGE COVERAGE. && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1024 PM MDT SUN AUG 5 2012 .UPDATE... FIRST ORDER OF BUSINESS WAS TO EXPIRE THE FLASH FLOOD WATCH AT 10 PM. ABX RADAR INDICATED HANDS DOWN OUR BEST STORM CORE PRECIP TOTALS ACROSS THE WEST TODAY. A FEW AREAS MAY HAVE PICKED UP 4 TO 6 INCHES OF RAIN. ONE SUCH AREA WAS THOREAU WHERE SIGNIFICANT FLASH FLOODING HAS BEEN REPORTED TODAY. NOW THE FOCUS IS WHERE ADJUST HIGHEST POPS. CURRENTLY THE RADAR AND SATELLITE TRENDS FOCUS THE BEST COVERAGE OVER THE NORTHERN MTS AND STILL SOMEWHAT ALONG THE CONT DVD. THE 01Z HRRR AND 03Z RUC HANDLE THE CURRENT PRECIP WELL SO HAVE GONE IN THIS DIRECTION ONCE AGAIN TONIGHT. THEREFORE EXPECTING CURRENT NMRS COVERAGE ACROSS THE NORTH TO MOVE SLOWLY ESE INTO THE JEMEZ AND SOUTHERN SANGRES AND THE NE HIGHLANDS. PLACED SCATTERED COVERAGE THERE WITH ISOLD AT BEST FOR THE REMAINDER OF THE AREA. GUYER && .PREV DISCUSSION...610 PM MDT SUN AUG 5 2012... .AVIATION... 00Z TAF CYCLE ANOTHER FAIRLY ACTIVE CONVECTIVE DAY WAS REALIZED TODAY...BUT MAINLY JUST ACROSS THE NW THIRD OR SO OF THE STATE. THROUGH THIS EVE EXPECT SCT TO LOCALLY NUMEROUS SHRA AND TSRA AGAIN MOSTLY WEST AND NORTH NM. STRONGEST STORMS WILL LIKELY ALSO REMAIN MAINLY N AND W WITH LOCALIZED AND RELATIVELY SHORT LIVED MVFR CIGS AS WELL AS ISOLATED INSTANCES OF SMALL HAIL ASSOCIATED WITH STRONGER TSRA. TSRA MENTIONED ONLY IN SAF...LVS AND FMN TO ACCOUNT FOR BEST CHANCE LOCALES FOR TSRA. OTHERWISE IN AREAS ALREADY WORKED OVER IN WEST OR OTHERWISE TOO UNLIKELY TO PICK UP A TSRA IN CENTRAL AND E NM EITHER VCSH MENTIONED OR NOTHING AT ALL.. MOST IF NOT ALL TSRA SHOULD DISSIPATE BY OR WITHIN A COUPLE HOURS OF MIDNIGHT. WHILE SOME SHRA AND TSRA LIKELY TO DEVELOP MON MAINLY AFTER 19Z...COVERAGE AND INTENSITY SHOULD OVERALL BE A LITTLE LESS THAN TODAY. 43 .PREV DISCUSSION...315 PM MDT SUN AUG 5 2012... AS EXPECTED...SOMEWHAT OF A SLOW START TO THE SHOWER AND THUNDERSTORM DEVELOPMENT THIS AFTERNOON. PRECIPITABLE WATER VALUES IN THE FLASH FLOOD WATCH AREA REMAIN ABOUT 120-150 PERCENT OF NORMAL SO NO CHANGES TO THE ONGOING WATCH. LOW LEVEL GULF MOISTURE COMBINING WITH MID LEVEL MONSOON MOISTURE PLUME TO GET PWAT VALUES UP THIS HIGH. STORMS FIRING OVER THE WEST-CENTRAL MTNS ARE MOVING NORTH AROUND 15 KTS BUT TRAINING OF SHOWERS AND STORMS OVER THE SAME AREA/DRAINAGE REMAINS THE MAIN CONCERN. DOPPLER RADAR ESTIMATING OVER 2 INCHES OF RAIN HAVE FALLEN FROM ONE CELL OR CELLS TRAINING OVER THOREAU IN THE PAST HOUR AND A HALF. ELSEWHERE...STORMS ARE DEVELOPING OVER THE NORTHERN MOUNTAINS AND SUSPECT THAT STORMS WILL BEGIN FIRING OVER OTHER MOUNTAIN LOCATIONS SHORTLY...AS MORE SURFACE HEATING ALLOWS UPDRAFTS TO PUNCH THROUGH THE SUBSIDENCE INVERSION AROUND 14K FEET AGL. MODELS ARE IN VERY GOOD TO EXCELLENT AGREEMENT FOR MONDAY...SLIDING THE CENTER OF THE UPPER LEVEL HIGH OVER NORTHWEST NM. STEERING LEVEL FLOW GRADUALLY BECOMES NORTH/NORTHWESTERLY OVER THE NORTH AND NORTHEAST TO EASTERLY OVER THE SOUTHWEST MOUNTAINS. RESIDUAL MOISTURE WILL COMBINE WITH THE ELEVATED HEAT SOURCES/MOUNTAINS TO GET SCATTERED SHOWERS AND THUNDERSTORMS GOING MONDAY AFTERNOON. HIGH RESOLUTION MODELS INDICATING THAT STORMS MOVING SOUTH FROM THE JEMEZ MOUNTAINS COULD BRING A ROUND OF THUNDERSTORMS TO BERNALILLO AND THE ALBUQUERQUE METRO AREA EARLY MONDAY EVENING. AND WITH STORM MOTION BECOMING NORTHWESTERLY MONDAY LATE AFTERNOON AND EVENING...SHOWERS AND STORMS WILL MOVE OFF THE SANGRE DE CRISTOS OUT ONTO THE NORTHEAST HIGHLANDS AND PLAINS. TUESDAY LOOKS VERY SIMILAR TO MONDAY WITH ONE EXCEPTION. AS THE UPPER HIGH CENTER SHIFTS FAR ENOUGH WESTWARD...NELY FLOW AT ALL LEVELS DEVELOPS AND BRINGS GULF MOISTURE TO THE NERN PLAINS AND CENTRAL HIGHLANDS TUESDAY AFTERNOON AND EVENING. THE MOIST NELY FLOW COMBINES WITH A WEAK WAVE TRANSLATING AROUND THE UPPER HIGH TO BRING HIGHER STORM CHANCES FROM THE CENTRAL MOUNTAINS EWD TUESDAY AFTERNOON AND EVENING. SIMILAR UPPER LEVEL AND SURFACE PATTERN CONTINUES INTO WEDNESDAY. DRIER MID AND UPPER LEVEL AIR BEGINS TO FILTER INTO CENTRAL AND SRN NM THURSDAY...WITH THE BEST THUNDERSTORM CHANCES OVER THE NRN MOUNTAINS. FRIDAY LOOKS...AT THIS POINT...LIKE THE DOWN DAY FOR THUNDERSTORMS THIS WEEK...OUTSIDE OF THE NRN AND WRN MOUNTAINS BUT WITH A NELY STEERING LEVEL FLOW IN PLACE...CANNOT RULE OUT SLIGHT CHANCES/ISOLATED STORMS FOR THE CENTRAL VALLEYS AS STORMS MOVE SOUTHWESTWARD. EXCELLENT AGREEMENT IN THE MEDIUM RANGE OPERATIONAL MODELS EXISTS FOR NEXT WEEKEND. UPPER HIGH REMAINS FAR ENOUGH NORTHWEST OF THE STATE FOR OCCASIONAL SHORT-WAVES/DISTURBANCES TO ROTATE AROUND THE HIGH CENTER AND INITIATE A NORTHEAST TO ELY SURFACE FLOW OVER THE REGION...RECHARGING SFC MOISTURE. THIS NW FLOW ALOFT IS QUITE THE FAVORABLE PATTERN FOR THE NORTHEAST AND EAST CENTRAL PLAINS. LONG RANGE FORECASTS GET QUITE INTERESTING. LATEST ECMWF FORECASTS A MAJOR BLOCKING PATTERN (OMEGA BLOCK) OVER THE GULF OF ALASKA...FORCING A LARGE AND UNSEASONABLY DEEP CLOSED UPPER LEVEL LOW OVER THE PACNW. THIS PATTERN WOULD FORCE THE UPPER HIGH BACK OVER THE SRN PLAINS STATES AND POSSIBLY OPEN THE DOOR FOR A DEEP SOUTHERLY FETCH OF SUBTROPICAL/TROPICAL MOISTURE INTO THE STATE. WE SHALL SEE. 33 .FIRE WEATHER... SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE QUITE NUMEROUS GOING INTO THE EVENING...ESPECIALLY ACROSS WESTERN AND NORTHERN PARTS OF NEW MEXICO. THIS BOOST IN STORM COVERAGE AND THE RELATIVELY LARGE FOOTPRINT OF WETTING RAINS RECEIVED YESTERDAY SHOULD PRECLUDE ANY FIRE WEATHER CONCERNS THROUGH THE NEAR TERM. BACK DOOR FRONT ADVANCED TOWARD ARIZONA...AND SHOULD CONTINUE TO PROVIDE SOME UPSLOPE TO AID IN THUNDERSTORM DEVELOPMENT ALONG AND NEAR THE CONTINENTAL DIVIDE. TEMPERATURES HAVE ALSO FALLEN BACK TO MORE REASONABLE VALUES AND CLOSER TO SEASONAL AVERAGES...ESPECIALLY IN THE EASTERN PLAINS. THIS ALONG WITH INCREASED CLOUD COVER AND ANTECEDENT RAIN CONDITIONS HAS KEPT RELATIVE HUMIDITY AT OR ABOVE 30 PERCENT IN THE FORECAST AREA...AND ANY GAP/CANYON WINDS HAVE DIMINISHED. GOOD TO EXCELLENT RH RECOVERY CAN BE EXPECTED TONIGHT AND INTO EARLY MONDAY MORNING. AS HIGH PRESSURE ALOFT REGAINS SOME SYMMETRY OVER THE FOUR CORNERS...IT WILL STEER FEWER STORMS INTO THE NORTHERN AND WESTERN MOUNTAINS OF NEW MEXICO ON MONDAY. ONCE THE HIGH NUDGES NORTHWESTWARD INTO TUESDAY...ANOTHER BACK DOOR FRONT WILL SLIDE INTO THE NORTHEASTERN PLAINS OF NEW MEXICO. AT THIS POINT...THE DIRECTIONAL SHIFT IN THE WINDS APPEARS TO BE A PRIMARY IMPACT AS NO MAJOR INCREASE IN DEWPOINTS IS ANTICIPATED. ANY UPTICK IN STORM COVERAGE IN THE NORTHEAST ON TUESDAY WOULD BE FAIRLY SUBTLE. FROM MID WEEK AND THROUGH THE EXTENDED FORECAST PERIOD VERY LITTLE MOVEMENT OF THE UPPER LEVEL HIGH IS FORESEEN. THIS WILL LIKELY DRIVE STORMS MOSTLY TO THE NORTHERN AND WESTERN MOUNTAINS OF NEW MEXICO WITH LESS THAN AVERAGE COVERAGE. && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ GUYER
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1040 AM EDT Mon Aug 6 2012 .NEAR TERM [Through Tonight]... Updated at: 1035am The main updates this morning were based on a forecast of a rainy and cloudy day over much of the area. PoPs were bumped up to categorical in the morning hours where a large area of rain is located (centered roughly near Lake Seminole). Hourly temperatures were trended towards the RAP which seemed to initialize quite well the location of the area of rain as well as the low and mid-level circulations associated with the lingering tropical wave. This resulted in high temperatures that were cooler than the previous forecast - in the mid 80s in many areas - and that may even be a stretch in areas like Marianna and Bainbridge which could very well see rain and dense cloud cover for much of the daytime hours. Therefore, the trends in temperature will be closely monitored in the event another update is warranted. The only other change was to add heavy rain wording into the areas with highest PoPs. Our 12z TAE sounding showed very high PWATs around 2.33", which is close to 130% of normal. Combined with light flow, moist adiabatic lapse rates, and very deep warm cloud depth over 14,000 feet - the ingredients are all there for any showers or storms to be efficient rainfall producers. Bias flags already inidicate that some of the area radars are underestimating the rain rates in this tropical environment, so areas that receive persistent heavy rainfall will need to be closely monitored for localized flooding potential. Given 3-hr BiasHPE rain estimates already close to FFG in some areas, and 1-hr values up to 60% of FFG in the areas of heavier rain, it is certainly within the realm of possibility that additional rain today will lead to a few spots of flooding. This threat will be added to the HWO. We could very well see a repeat of yesterday to the east of the circulation center of the tropical wave, just displaced slightly further west to account for the westward drift of the wave. Yesterday there was a substantial amount of deep convection and thunderstorms that formed near the I-75 corridor in Florida near a low-level convergence zone. It appears that a similar band of deep convection is beginning to form from near K40J to the south into offshore areas. This could affect the eastern portions of our forecast area today, from CTY/40J north to near VLD, TMA, FZG. && .SHORT TERM [Tuesday Through Wednesday]... On Tuesday we will still be dealing with the passing trough mentioned above, and will likely have another waiting in the wings across eastern Florida. In addition to the surface features, the upper level trough will expand into the Southeast, providing a bit more synoptic scale forcing for ascent. These combined will keep rain chances well above average on Tuesday, and high temperatures near or just below average. By Wednesday, the surface subtropical ridge will begin to nose back in from the east and start to shunt the pesky tropical waves out of the local area. However, it won`t be until late in the day that the ridge will take hold, and the upper level trough will remain in place, so we will probably still have plenty of shower and thunderstorm activity across our western forecast area. Thus, rain chances will remain above average in those locations on Wednesday. && .LONG TERM [Wednesday Night through Sunday]... Not much change from the previous extended package, as our very atypical summer governed by an unusually steep Upper Level Trof down the eastern seaboard will continue through the bulk of the period. This "disturbed pattern" combined with onshore SW flow at lower levels, and plenty of deep layer Tropical Moisture will keep rain chances elevated and daytime high temperatures near or slightly below climo. By the very end of the period (Sunday and Monday), we could see some slight improvements to the current fcst as the Trof tries to exit off to the E, but the deep layer moisture might very well remain entrenched over the region due to very weak forcing, so PoPs could still remain elevated. Therefore, will likely need to see a few more model cycles before confidence is high enough to make a final determination. && .AVIATION [Beginning 12Z Monday]... With plenty of deep layer moisture combined with a weak low-mid level circulation moving slowly westward through the CWA today, low clouds, showers, and thunderstorms will be sct to widespread at the terminals. With the weakly defined "center" of this circulation over central portions of the CWA as of early this morning, the best chances for rain will be at TLH, ABY, DHN, and ECP, with rainfall already ongoing at TLH and and ABY. VLD has temporarily cleared out, which should hold off the convection until later this morning or early this afternoon, but this clearing may also allow for a 1-2 hr period of Low Cigs and Vis between 12 and 14 UTC. Overall, expect prevailing MVFR to IFR conditions at most of the Taf sites with the with periods of VFR conditions possible outside of the convection. && .MARINE... Showers and thunderstorms will be possible over the next couple of days as a series of weak tropical waves traverse our waters from southeast to northwest. Winds and seas will remain below headline criteria through the period. However, winds will briefly rise to near cautionary levels as the subtropical ridge noses back in over our coastal waters Tuesday through Wednesday. Additionally, swells from Tropical Storm Ernesto will enhance seas beginning on Wednesday, especially over our western waters. && .FIRE WEATHER... A generally wet and disturbed pattern will continue across the Tri-State area for much if not all of the upcoming week. This will keep afternoon relative humidities well above critical thresholds through the period. && .TAE WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AL...None. GM...None. && $$ NEAR TERM...Lamers SHORT TERM...Harrigan LONG TERM...Gould AVIATION...Gould MARINE...Harrigan FIRE WEATHER...Gould
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1028 AM EDT Mon Aug 6 2012 .NEAR TERM [Through Tonight]... Updated at: 1025am The main updates this morning were based on a forecast of a rainy and cloudy day over much of the area. PoPs were bumped up to categorical in the morning hours where a large area of rain is located (centered roughly near Lake Seminole). Hourly temperatures were trended towards the RAP which seemed to initialize quite well the location of the area of rain as well as the low and mid-level circulations associated with the lingering tropical wave. This resulted in high temperatures that were cooler than the previous forecast - in the mid 80s in many areas - and that may even be a stretch in areas like Marianna and Bainbridge which could very well see rain and dense cloud cover for much of the daytime hours. Therefore, the trends in temperature will be closely monitored in the event another update is warranted. The only other change was to add heavy rain wording into the areas with highest PoPs. Our 12z TAE sounding showed very high PWATs around 2.33", which is close to 130% of normal. Combined with light flow, moist adiabatic lapse rates, and very deep warm cloud depth over 14,000 feet - the ingredients are all there for any showers or storms to be efficient rainfall producers. Bias flags already inidicate that some of the area radars are underestimating the rain rates in this tropical environment, so areas that receive persistent heavy rainfall will need to be closely monitored for localized flooding potential. Given 3-hr BiasHPE rain estimates already close to FFG in some areas, and 1-hr values up to 60% of FFG in the areas of heavier rain, it is certainly within the realm of possibility that additional rain today will lead to a few spots of flooding. This threat will be added to the HWO. && .SHORT TERM [Tuesday Through Wednesday]... On Tuesday we will still be dealing with the passing trough mentioned above, and will likely have another waiting in the wings across eastern Florida. In addition to the surface features, the upper level trough will expand into the Southeast, providing a bit more synoptic scale forcing for ascent. These combined will keep rain chances well above average on Tuesday, and high temperatures near or just below average. By Wednesday, the surface subtropical ridge will begin to nose back in from the east and start to shunt the pesky tropical waves out of the local area. However, it won`t be until late in the day that the ridge will take hold, and the upper level trough will remain in place, so we will probably still have plenty of shower and thunderstorm activity across our western forecast area. Thus, rain chances will remain above average in those locations on Wednesday. && .LONG TERM [Wednesday Night through Sunday]... Not much change from the previous extended package, as our very atypical summer governed by an unusually steep Upper Level Trof down the eastern seaboard will continue through the bulk of the period. This "disturbed pattern" combined with onshore SW flow at lower levels, and plenty of deep layer Tropical Moisture will keep rain chances elevated and daytime high temperatures near or slightly below climo. By the very end of the period (Sunday and Monday), we could see some slight improvements to the current fcst as the Trof tries to exit off to the E, but the deep layer moisture might very well remain entrenched over the region due to very weak forcing, so PoPs could still remain elevated. Therefore, will likely need to see a few more model cycles before confidence is high enough to make a final determination. && .AVIATION [Beginning 12Z Monday]... With plenty of deep layer moisture combined with a weak low-mid level circulation moving slowly westward through the CWA today, low clouds, showers, and thunderstorms will be sct to widespread at the terminals. With the weakly defined "center" of this circulation over central portions of the CWA as of early this morning, the best chances for rain will be at TLH, ABY, DHN, and ECP, with rainfall already ongoing at TLH and and ABY. VLD has temporarily cleared out, which should hold off the convection until later this morning or early this afternoon, but this clearing may also allow for a 1-2 hr period of Low Cigs and Vis between 12 and 14 UTC. Overall, expect prevailing MVFR to IFR conditions at most of the Taf sites with the with periods of VFR conditions possible outside of the convection. && .MARINE... Showers and thunderstorms will be possible over the next couple of days as a series of weak tropical waves traverse our waters from southeast to northwest. Winds and seas will remain below headline criteria through the period. However, winds will briefly rise to near cautionary levels as the subtropical ridge noses back in over our coastal waters Tuesday through Wednesday. Additionally, swells from Tropical Storm Ernesto will enhance seas beginning on Wednesday, especially over our western waters. && .FIRE WEATHER... A generally wet and disturbed pattern will continue across the Tri-State area for much if not all of the upcoming week. This will keep afternoon relative humidities well above critical thresholds through the period. && .TAE WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AL...None. GM...None. && $$ NEAR TERM...Lamers SHORT TERM...Harrigan LONG TERM...Gould AVIATION...Gould MARINE...Harrigan FIRE WEATHER...Gould
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
1024 AM CDT MON AUG 6 2012 .UPDATE... REDUCED/REMOVED RAIN CHANCES WEST OF AN ENID TO OKLAHOMA CITY TO ATOKA LINE THROUGH 1 PM CDT. ALSO...NUDGED HIGHS UPWARD OVER NORTHERN OKLAHOMA AND TWEAKED SKY COVER AND WINDS THIS AFTERNOON. && .DISCUSSION... HOT CONDITIONS WILL AGAIN PREVAIL THIS AFTERNOON WITH LOW CHANCES FOR SHOWERS AND STORMS MAINLY SOUTHWEST OF AN ALVA TO CHICKASHA TO ADA LINE. THROUGH 1 PM CDT...MAINLY HOT AND DRY CONDITIONS ARE EXPECTED. CONFINED 20 PERCENT RAIN CHANCES TO FAR WESTERN OKLAHOMA AND PARTS OF WESTERN NORTH TEXAS SOUTH OF A KNOX CITY TO WICHITA FALLS LINE WHERE LATEST SATELLITE IMAGERY DEPICTED SOME MID LEVEL CLOUDINESS. LATEST HRRR RUNS SUGGESTED ISOLATED DEVELOPMENT NEAR I-35...WHICH SEEMS TO BE VERY POORLY HANDLED AS THERE ARE NO CUMULUS CLOUDS AND WEAK LAPSE RATES IN THESE AREAS. THIS AFTERNOON AND EVENING...LATEST NAM12 AND HRRR RUNS INDICATED ISOLATED TO PERHAPS SCATTERED SHOWERS AND STORMS WILL DEVELOP OVER MAINLY WESTERN AND SOUTHERN OKLAHOMA AS WELL AS WESTERN NORTH TEXAS. FIRST DEVELOPMENT MAY OCCUR IN THE 1 TO 3 PM TIME FRAME NEAR A GAGE TO WICHITA FALLS TO DURANT LINE ONCE CONVECTIVE TEMPERATURES IN THE 95 TO 100 DEGREE RANGE ARE MET. GUSTY WINDS...POSSIBLY SEVERE OF 60 MPH OR GREATER DUE TO STEEP LOW LEVEL LAPSE RATES AND DCAPE VALUES AROUND 1500 J/KG...AND LIGHTNING STRIKES WHICH CAN IGNITE FIRES WILL BE THE MAIN HAZARDS. RAINFALL AMOUNTS WILL GENERALLY BE LIGHT...THOUGH ONE OR TWO LOCATIONS MAY RECEIVE 0.50 INCH OR MORE. DUE TO FAIRLY WEAK SHEAR...STORMS SHOULD REMAIN UNORGANIZED AND MOVE SOUTHEAST 15 TO 20 MPH. STORMS WILL WEAKEN AROUND SUNSET WITH THE LOSS OF DAYTIME HEATING. HIGHS TODAY SHOULD REACH THE CENTURY MARK OR HIGHER IN MOST LOCATIONS. WILL BE CLOSE TO HEAT ADVISORY CRITERIA WITH HEAT INDICES NEAR 105 DEGREES ACROSS WESTERN NORTH TEXAS AND SOUTHERN OKLAHOMA...BUT HELD OFF WITH ISSUANCE DUE TO LOW CONFIDENCE. PRODUCTS HAVE BEEN UPDATED. MBS && .PREV DISCUSSION... /ISSUED 640 AM CDT MON AUG 6 2012/ AVIATION... 06/12Z TAFS...VFR CONDITIONS ARE EXPECTED TO PREVAIL. ISOLATED OR SCATTERED STORMS POSSIBLE TODAY INTO THIS EVENING BUT PROBABILITY TOO LOW TO MENTION IN THIS ISSUANCE. UPDATE... ISOLATED STORM NEAR WATONGA DEVELOPING EARLIER AND A BIT FARTHER NORTH THAN PREVIOUSLY EXPECTED SO WILL UPDATE TO SPREAD LOW POPS FARTHER NORTH AND EAST INTO OKC METRO. LATEST HRRR OUTPUT FAIRLY AGGRESSIVE WITH STORMS ACROSS CENTRAL INTO SOUTH-CENTRAL OKLAHOMA DURING THE MORNING. THIS IS LIKELY OVERDONE AND WILL NOT GET TOO CARRIED AWAY WITH PROBABILITIES AND WILL LEAVE HIGHER POPS ACROSS SOUTHERN OKLAHOMA INTO WRN N TEXAS LATE TODAY. PREV DISCUSSION... /ISSUED 426 AM CDT MON AUG 6 2012/ DISCUSSION... OVERALL LITTLE CHANGE TO GOING FORECAST OTHER THAN INCLUDING LOW PROBABILITIES FOR THUNDERSTORMS LATER TODAY NEAR STALLED FRONTAL BOUNDARY NEAR RED RIVER VALLEY. TEMPERATURES FORECAST TO WARM NEXT COUPLE OF DAYS AND ALL MODEL GUIDANCE STILL COOLS US DOWN A BIT WEDNESDAY AND THURSDAY WITH WEAK FRONTAL BOUNDARY AND INCREASE IN CLOUD COVER. SCATTERED STORMS STILL APPEAR POSSIBLE LATE TUESDAY THROUGH WEDNESDAY WITH WEAK S/WV PROGRESSING AROUND UPPER RIDGE...BUT WRF/GFS MODELS LIKELY TOO AGGRESSIVE WITH WIDESPREAD RAIN DUE TO FORECASTING TOO MUCH BOUNDARY LAYER MOISTURE. WILL KEEP POPS SIMILAR TO PREVIOUS FORECAST THROUGH LATE WEDNESDAY BEFORE ANOTHER FEW DAYS OF WARMING TEMPS. MODELS TRYING TO COME INTO BETTER AGREEMENT WITH A STRONGER FRONT IN THE FRIDAY-SATURDAY TIME FRAME. WILL NOT MENTION POPS THIS FAR OUT BUT WILL CONTINUE SLIGHT COOLING TREND INTO NEXT WEEKEND. ALTHOUGH WINDS FOR MOST OF THE WEEK WILL BE ON THE LIGHT SIDE... LOW AFTERNOON HUMIDITIES AND HOT TEMPS WILL KEEP WILDFIRE CONCERNS ELEVATED. ALSO...DESPITE MAX HEAT INDEX AND LOW TEMP FORECASTS NEAR OR MEETING CRITERIA...WE HELD OFF ON ISSUING HEAT ADVISORY FOR SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS DUE TO UNCERTAINTY OF MID-WEEK TEMPS. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 102 77 103 78 / 10 10 10 20 HOBART OK 102 74 103 75 / 30 20 20 30 WICHITA FALLS TX 106 79 107 79 / 30 20 20 30 GAGE OK 99 71 102 71 / 30 10 30 30 PONCA CITY OK 102 72 103 74 / 0 10 10 20 DURANT OK 102 76 103 78 / 20 20 10 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 17/03
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
640 AM CDT MON AUG 6 2012 .AVIATION... 06/12Z TAFS...VFR CONDITIONS ARE EXPECTED TO PREVAIL. ISOLATED OR SCATTERED STORMS POSSIBLE TODAY INTO THIS EVENING BUT PROBABILITY TOO LOW TO MENTION IN THIS ISSUANCE. && .UPDATE... ISOLATED STORM NEAR WATONGA DEVELOPING EARLIER AND A BIT FARTHER NORTH THAN PREVIOUSLY EXPECTED SO WILL UPDATE TO SPREAD LOW POPS FARTHER NORTH AND EAST INTO OKC METRO. LATEST HRRR OUTPUT FAIRLY AGGRESSIVE WITH STORMS ACROSS CENTRAL INTO SOUTH-CENTRAL OKLAHOMA DURING THE MORNING. THIS IS LIKELY OVERDONE AND WILL NOT GET TOO CARRIED AWAY WITH PROBABILITIES AND WILL LEAVE HIGHER POPS ACROSS SOUTHERN OKLAHOMA INTO WRN N TEXAS LATE TODAY. && .PREV DISCUSSION... /ISSUED 426 AM CDT MON AUG 6 2012/ DISCUSSION... OVERALL LITTLE CHANGE TO GOING FORECAST OTHER THAN INCLUDING LOW PROBABILITIES FOR THUNDERSTORMS LATER TODAY NEAR STALLED FRONTAL BOUNDARY NEAR RED RIVER VALLEY. TEMPERATURES FORECAST TO WARM NEXT COUPLE OF DAYS AND ALL MODEL GUIDANCE STILL COOLS US DOWN A BIT WEDNESDAY AND THURSDAY WITH WEAK FRONTAL BOUNDARY AND INCREASE IN CLOUD COVER. SCATTERED STORMS STILL APPEAR POSSIBLE LATE TUESDAY THROUGH WEDNESDAY WITH WEAK S/WV PROGRESSING AROUND UPPER RIDGE...BUT WRF/GFS MODELS LIKELY TOO AGGRESSIVE WITH WIDESPREAD RAIN DUE TO FORECASTING TOO MUCH BOUNDARY LAYER MOISTURE. WILL KEEP POPS SIMILAR TO PREVIOUS FORECAST THROUGH LATE WEDNESDAY BEFORE ANOTHER FEW DAYS OF WARMING TEMPS. MODELS TRYING TO COME INTO BETTER AGREEMENT WITH A STRONGER FRONT IN THE FRIDAY-SATURDAY TIME FRAME. WILL NOT MENTION POPS THIS FAR OUT BUT WILL CONTINUE SLIGHT COOLING TREND INTO NEXT WEEKEND. ALTHOUGH WINDS FOR MOST OF THE WEEK WILL BE ON THE LIGHT SIDE... LOW AFTERNOON HUMIDITIES AND HOT TEMPS WILL KEEP WILDFIRE CONCERNS ELEVATED. ALSO...DESPITE MAX HEAT INDEX AND LOW TEMP FORECASTS NEAR OR MEETING CRITERIA...WE HELD OFF ON ISSUING HEAT ADVISORY FOR SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS DUE TO UNCERTAINTY OF MID-WEEK TEMPS. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 102 77 103 78 / 20 10 10 20 HOBART OK 102 74 103 75 / 30 20 20 30 WICHITA FALLS TX 106 79 107 79 / 30 20 20 30 GAGE OK 99 71 102 71 / 20 10 30 30 PONCA CITY OK 98 72 103 74 / 0 10 10 20 DURANT OK 102 76 103 78 / 20 20 10 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 26/11
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
551 AM CDT MON AUG 6 2012 .UPDATE... ISOLATED STORM NEAR WATONGA DEVELOPING EARLIER AND A BIT FARTHER NORTH THAN PREVIOUSLY EXPECTED SO WILL UPDATE TO SPREAD LOW POPS FARTHER NORTH AND EAST INTO OKC METRO. LATEST HRRR OUTPUT FAIRLY AGGRESSIVE WITH STORMS ACROSS CENTRAL INTO SOUTH-CENTRAL OKLAHOMA DURING THE MORNING. THIS IS LIKELY OVERDONE AND WILL NOT GET TOO CARRIED AWAY WITH PROBABILITIES AND WILL LEAVE HIGHER POPS ACROSS SOUTHERN OKLAHOMA INTO WRN N TEXAS LATE TODAY. && .PREV DISCUSSION... /ISSUED 426 AM CDT MON AUG 6 2012/ DISCUSSION... OVERALL LITTLE CHANGE TO GOING FORECAST OTHER THAN INCLUDING LOW PROBABILITIES FOR THUNDERSTORMS LATER TODAY NEAR STALLED FRONTAL BOUNDARY NEAR RED RIVER VALLEY. TEMPERATURES FORECAST TO WARM NEXT COUPLE OF DAYS AND ALL MODEL GUIDANCE STILL COOLS US DOWN A BIT WEDNESDAY AND THURSDAY WITH WEAK FRONTAL BOUNDARY AND INCREASE IN CLOUD COVER. SCATTERED STORMS STILL APPEAR POSSIBLE LATE TUESDAY THROUGH WEDNESDAY WITH WEAK S/WV PROGRESSING AROUND UPPER RIDGE...BUT WRF/GFS MODELS LIKELY TOO AGGRESSIVE WITH WIDESPREAD RAIN DUE TO FORECASTING TOO MUCH BOUNDARY LAYER MOISTURE. WILL KEEP POPS SIMILAR TO PREVIOUS FORECAST THROUGH LATE WEDNESDAY BEFORE ANOTHER FEW DAYS OF WARMING TEMPS. MODELS TRYING TO COME INTO BETTER AGREEMENT WITH A STRONGER FRONT IN THE FRIDAY-SATURDAY TIME FRAME. WILL NOT MENTION POPS THIS FAR OUT BUT WILL CONTINUE SLIGHT COOLING TREND INTO NEXT WEEKEND. ALTHOUGH WINDS FOR MOST OF THE WEEK WILL BE ON THE LIGHT SIDE... LOW AFTERNOON HUMIDITIES AND HOT TEMPS WILL KEEP WILDFIRE CONCERNS ELEVATED. ALSO...DESPITE MAX HEAT INDEX AND LOW TEMP FORECASTS NEAR OR MEETING CRITERIA...WE HELD OFF ON ISSUING HEAT ADVISORY FOR SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS DUE TO UNCERTAINTY OF MID-WEEK TEMPS. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 102 77 103 78 / 20 10 10 20 HOBART OK 102 74 103 75 / 30 20 20 30 WICHITA FALLS TX 106 79 107 79 / 30 20 20 30 GAGE OK 99 71 102 71 / 20 10 30 30 PONCA CITY OK 98 72 103 74 / 0 10 10 20 DURANT OK 102 76 103 78 / 20 20 10 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 26/11
AREA FORECAST DISCUSSION
NWS GOODLAND KS
418 PM MDT MON AUG 6 2012 .UPDATE... ISSUED AT 415 PM MDT MON AUG 6 2012 UPDATED TO INCLUDE THUNDERSTORM CHANCES IN THE WEST. CONVECTION HAS INITIATED ALONG A SURFACE TROUGH IN NORTHEAST COLORADO. STORM MOTIONS ARE ALMOST DUE SOUTH SO NOT SURE HOW FAR EAST THESE WILL BE ABLE TO MOVE THIS EVENING. FURTHERMORE...DEW POINTS ARE QUITE LOW. FOR THOSE REASONS...LIMITED POPS TO 30 IN THE FAR NORTHWEST AND 20 ELSEWHERE. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 236 PM MDT MON AUG 6 2012 THROUGH TONIGHT...SHORTWAVE TROUGH WILL TRANSLATE SOUTHEASTWARD THE NORTHERN PLAINS. STRONGEST FORCING FOR ASCENT WILL REMAIN NORTHEAST OF THE FORECAST AREA. HOWEVER...WITH A SURFACE LOW DEVELOPING ACROSS NORTHEAST COLORADO...DO EXPECT ISOLATED TO SCATTERED THUNDERSTORMS TO DEVELOP ACROSS NORTHERN/NORTHEASTERN PORTIONS OF THE FORECAST AREA AFTER 06Z. WILL ALSO NEED TO MONITOR A WEAK AREA OF SURFACE CONVERGENCE JUST TO THE WEST OF THE FORECAST AREA WHERE A SHALLOW CU FIELD CONTINUES TO DEVELOP. LATEST RUNS OF THE HRRR DEVELOP CONVECTION IN THIS AREA WITH A GENERAL EASTWARD/SOUTHEASTWARD MOVEMENT. NOT COMPLETELY SOLD ON THIS SOLUTION SO OPTING TO KEEP POPS OUT OF THE FORECAST FOR NOW. WILL NEED TO MONITOR AND REEVALUATE AS THE AFTERNOON GOES ON. TUESDAY...SLIGHTLY STRONGER SHORTWAVE TROUGH WILL BEGIN TO IMPACT THE REGION DURING THE DAY TUESDAY. WILL LIKELY SEE A LULL IN PRECIP DURING THE MORNING HOURS IN THE WAKE OF THE DEPARTING OVERNIGHT SYSTEM WITH PRECIP CHANCES INCREASING DURING THE AFTERNOON HOURS. DEEP LAYER SHEAR WILL INCREASE TO AROUND 30-35 KTS DURING THE AFTERNOON HOURS WHICH WILL HELP ORGANIZE THUNDERSTORM UPDRAFTS. ONE LIMITING FACTOR WILL BE MINIMAL AVAILABLE INSTABILITY WITH SBCAPE VALUES OF 500-1000 J/KG. POINT SOUNDINGS DO INDICATE AN INVERTED-V STRUCTURE SO WOULD ANTICIPATE GUSTY OUTFLOW WINDS BEING THE PRIMARY THREAT TOMORROW AFTERNOON/EVENING. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 236 PM MDT MON AUG 6 2012 TUESDAY NIGHT-THURSDAY...LARGE SCALE H5 RIDGE WILL AMPLIFY OVER THE NORTHERN ROCKIES THROUGH THE PERIOD...WITH MAIN CONCERN BEING THE CHANCE FOR LINGERING PRECIPITATION OVER PORTIONS OF THE CWA TUESDAY NIGHT WITH PRECIPITATION CHANCES LOOKING TO BE VERY SMALL AFTER THAT LARGE SCALE SUBSIDENCE OVERSPREADS THE AREA WITH DEEP LAYER FLOW ALOFT OUT OF THE NORTH-NORTHWEST KEEPING ANY DEEP MOISTURE RETURN TO THE AREA LIMITED. FOR TUESDAY NIGHT HOWEVER...DIV Q FIELDS SUGGEST LARGE SCALE SUBSIDENCE WILL OVERSPREAD THE CWA AFTER 03Z...WHICH SHOULD BEGIN TO DIMINISH PRECIPITATION POTENTIAL PRETTY QUICKLY OVERNIGHT. WHILE THERE WILL BE LARGE SCALE SUBSIDENCE...THINK THERE WILL BE AT LEAST A SHORT WINDOW FOR PRECIPITATION DURING THE EVENING HOURS...MAINLY ALONG AND SFC TROUGH EXPECTED TO STRETCH FROM FIRSTVIEW TO MCCOOK. WITH MIXED LAYER CINH VALUES FAIRLY HIGH AND AFOREMENTIONED SUBSIDENCE CONFIDENCE IN PRECIPITATION FAIRLY LOW. ALTHOUGH SREF AND GEFS HAVE FAIRLY HIGH PROBABILITIES (>75%) IN EASTERN CWA...DO NOT THINK CONFIDENCE IS HIGH ENOUGH TO GO MORE THAN 20-40 PERCENT CHANCES THROUGH THE EVENING HOURS. AS H5 RIDGE AMPLIFIES AND MUCH DRIER AIR WORKS INTO THE CWA...THINK PRECIP CHANCES WILL REMAIN VERY LOW TO PRACTICALLY NOTHING THROUGH THE REST OF THE PERIOD. SEEMS TO BE A FAIRLY LARGE SPREAD BETWEEN MODELS WITH RESPECT TO HOW WARM THINGS WILL GET ACROSS THE AREA. WHILE GFS IS MUCH COOLER THAN OTHER MODELS AND GIVEN THE OVERALL FLOW PATTERN WOULD NOT BE UNHEARD OF FOR A COOLER AIR MASS TO BACK INTO CWA. THAT BEING SAID...GFS HAS A FAIRLY WELL DOCUMENTED COLD BIAS THIS SUMMER AND THINK OVERALL BIAS CORRECTED VALUES IN THE MID/UPPER 90S LOOK REASONABLE. MUCH DRIER AIR IS EXPECTED TO MOVE INTO THE AREA WEDNESDAY AFTERNOON ALLOWING RH`S TO APPROACH CRITICAL VALUES. OVERALL DO NOT THINK CONDITIONS WILL BE LONG LASTING AND DO NOT PLAN ON ISSUING ANY WATCHES AT THIS POINT AND THINK THE BIGGEST IMPACT OF DRIER AIR MASS WILL BE TO ALLOW TEMPS TO BE RATHER COOL GIVEN LIGHT WINDS/CLEAR SKIES AND DRY AIR. IN THE EXTENDED (FRIDAY-NIGHT-MONDAY)...WHILE MEDIUM RANGE MODELS START THE PERIOD IN REASONABLE AGREEMENT...DIFFERENCES EMERGE FAIRLY QUICKLY IN THE PERIOD WITH RESPECT TO HANDLING OF SHORT WAVE TROUGH MOVES AROUND TOP OF THE AMPLIFIED H5 RIDGE AND WHAT IMPACT...IF ANY THIS TROUGH HAS ON LARGE SCALE RIDGE PATTERN. THESE DIFFERENCES DO NOT LEAD TO A LOT OF CONFIDENCE IN FORECAST FROM SATURDAY ON...AND PLAN ON KEEPING FORECAST NEAR CONSENSUS DATA FOR THE TIME BEING UNTIL A BETTER FAVORED SOLUTION APPEARS...ALTHOUGH THINK WEIGHTING BLENDS A BIT MORE TOWARDS THE ECWMF IS IN ORDER BASED ON THE GEFS DATA. LATEST ECMWF HAS COME IN A BIT COOLER THAN PREVIOUS RUNS AND GIVEN EASTERLY SFC FLOW AND STRONG HIGH AROUND BASE OF SFC HIGH THINK A GENERAL COOLING TREND IS IN ORDER. WITH MOST NIGHTS NOT REALLY BRINGING A CLEAR SIGNAL FOR WARM TEMPS (DENSE CLOUD COVER...STRONG WINDS...ETC) HAVE WORKED THE 3-5 DEGREE COOLER BIAS CORRECTED SOLUTIONS INTO OVERNIGHT LOW FORECASTS WHERE I COULD...TO PICK UP OUR NORMALLY COLDEST SPOTS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1152 AM MDT MON AUG 6 2012 EXPECT PRIMARILY VFR CONDITIONS AT KGLD AND KMCK THROUGH THE EFFECTIVE PERIOD. PRIMARY QUESTION MARK WILL CENTER ON WHAT...IF ANY...IMPACT CONVECTION WILL HAVE DURING THE OVERNIGHT HOURS. GUIDANCE CONTINUES TO SUPPORT HIGHER CHANCES FOR CONVECTION AT KMCK SO WILL CONTINUE VCTS MENTION. HAVE ADJUSTED THE TIMING TO BETTER COINCIDE WITH THE HIGHEST LIKELIHOOD OF PRECIP. LEFT MENTION OF PRECIP OUT OF THE KGLD TAF GIVEN THE LOWER PROBABILITY OF A DIRECT IMPACT. WINDS WILL BECOME LIGHT AND VARIABLE LATE TONIGHT THROUGH THE END OF THE EFFECTIVE PERIOD AS A SURFACE TROUGH RESIDES OVER THE AREA. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...024 SHORT TERM...FOLTZ LONG TERM...JRM AVIATION...FOLTZ
AREA FORECAST DISCUSSION
NWS GOODLAND KS
237 PM MDT MON AUG 6 2012 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 236 PM MDT MON AUG 6 2012 THROUGH TONIGHT...SHORTWAVE TROUGH WILL TRANSLATE SOUTHEASTWARD THE NORTHERN PLAINS. STRONGEST FORCING FOR ASCENT WILL REMAIN NORTHEAST OF THE FORECAST AREA. HOWEVER...WITH A SURFACE LOW DEVELOPING ACROSS NORTHEAST COLORADO...DO EXPECT ISOLATED TO SCATTERED THUNDERSTORMS TO DEVELOP ACROSS NORTHERN/NORTHEASTERN PORTIONS OF THE FORECAST AREA AFTER 06Z. WILL ALSO NEED TO MONITOR A WEAK AREA OF SURFACE CONVERGENCE JUST TO THE WEST OF THE FORECAST AREA WHERE A SHALLOW CU FIELD CONTINUES TO DEVELOP. LATEST RUNS OF THE HRRR DEVELOP CONVECTION IN THIS AREA WITH A GENERAL EASTWARD/SOUTHEASTWARD MOVEMENT. NOT COMPLETELY SOLD ON THIS SOLUTION SO OPTING TO KEEP POPS OUT OF THE FORECAST FOR NOW. WILL NEED TO MONITOR AND REEVALUATE AS THE AFTERNOON GOES ON. TUESDAY...SLIGHTLY STRONGER SHORTWAVE TROUGH WILL BEGIN TO IMPACT THE REGION DURING THE DAY TUESDAY. WILL LIKELY SEE A LULL IN PRECIP DURING THE MORNING HOURS IN THE WAKE OF THE DEPARTING OVERNIGHT SYSTEM WITH PRECIP CHANCES INCREASING DURING THE AFTERNOON HOURS. DEEP LAYER SHEAR WILL INCREASE TO AROUND 30-35 KTS DURING THE AFTERNOON HOURS WHICH WILL HELP ORGANIZE THUNDERSTORM UPDRAFTS. ONE LIMITING FACTOR WILL BE MINIMAL AVAILABLE INSTABILITY WITH SBCAPE VALUES OF 500-1000 J/KG. POINT SOUNDINGS DO INDICATE AN INVERTED-V STRUCTURE SO WOULD ANTICIPATE GUSTY OUTFLOW WINDS BEING THE PRIMARY THREAT TOMORROW AFTERNOON/EVENING. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 236 PM MDT MON AUG 6 2012 TUESDAY NIGHT-THURSDAY...LARGE SCALE H5 RIDGE WILL AMPLIFY OVER THE NORTHERN ROCKIES THROUGH THE PERIOD...WITH MAIN CONCERN BEING THE CHANCE FOR LINGERING PRECIPITATION OVER PORTIONS OF THE CWA TUESDAY NIGHT WITH PRECIPITATION CHANCES LOOKING TO BE VERY SMALL AFTER THAT LARGE SCALE SUBSIDENCE OVERSPREADS THE AREA WITH DEEP LAYER FLOW ALOFT OUT OF THE NORTH-NORTHWEST KEEPING ANY DEEP MOISTURE RETURN TO THE AREA LIMITED. FOR TUESDAY NIGHT HOWEVER...DIV Q FIELDS SUGGEST LARGE SCALE SUBSIDENCE WILL OVERSPREAD THE CWA AFTER 03Z...WHICH SHOULD BEGIN TO DIMINISH PRECIPITATION POTENTIAL PRETTY QUICKLY OVERNIGHT. WHILE THERE WILL BE LARGE SCALE SUBSIDENCE...THINK THERE WILL BE AT LEAST A SHORT WINDOW FOR PRECIPITATION DURING THE EVENING HOURS...MAINLY ALONG AND SFC TROUGH EXPECTED TO STRETCH FROM FIRSTVIEW TO MCCOOK. WITH MIXED LAYER CINH VALUES FAIRLY HIGH AND AFOREMENTIONED SUBSIDENCE CONFIDENCE IN PRECIPITATION FAIRLY LOW. ALTHOUGH SREF AND GEFS HAVE FAIRLY HIGH PROBABILITIES (>75%) IN EASTERN CWA...DO NOT THINK CONFIDENCE IS HIGH ENOUGH TO GO MORE THAN 20-40 PERCENT CHANCES THROUGH THE EVENING HOURS. AS H5 RIDGE AMPLIFIES AND MUCH DRIER AIR WORKS INTO THE CWA...THINK PRECIP CHANCES WILL REMAIN VERY LOW TO PRACTICALLY NOTHING THROUGH THE REST OF THE PERIOD. SEEMS TO BE A FAIRLY LARGE SPREAD BETWEEN MODELS WITH RESPECT TO HOW WARM THINGS WILL GET ACROSS THE AREA. WHILE GFS IS MUCH COOLER THAN OTHER MODELS AND GIVEN THE OVERALL FLOW PATTERN WOULD NOT BE UNHEARD OF FOR A COOLER AIR MASS TO BACK INTO CWA. THAT BEING SAID...GFS HAS A FAIRLY WELL DOCUMENTED COLD BIAS THIS SUMMER AND THINK OVERALL BIAS CORRECTED VALUES IN THE MID/UPPER 90S LOOK REASONABLE. MUCH DRIER AIR IS EXPECTED TO MOVE INTO THE AREA WEDNESDAY AFTERNOON ALLOWING RH`S TO APPROACH CRITICAL VALUES. OVERALL DO NOT THINK CONDITIONS WILL BE LONG LASTING AND DO NOT PLAN ON ISSUING ANY WATCHES AT THIS POINT AND THINK THE BIGGEST IMPACT OF DRIER AIR MASS WILL BE TO ALLOW TEMPS TO BE RATHER COOL GIVEN LIGHT WINDS/CLEAR SKIES AND DRY AIR. IN THE EXTENDED (FRIDAY-NIGHT-MONDAY)...WHILE MEDIUM RANGE MODELS START THE PERIOD IN REASONABLE AGREEMENT...DIFFERENCES EMERGE FAIRLY QUICKLY IN THE PERIOD WITH RESPECT TO HANDLING OF SHORT WAVE TROUGH MOVES AROUND TOP OF THE AMPLIFIED H5 RIDGE AND WHAT IMPACT...IF ANY THIS TROUGH HAS ON LARGE SCALE RIDGE PATTERN. THESE DIFFERENCES DO NOT LEAD TO A LOT OF CONFIDENCE IN FORECAST FROM SATURDAY ON...AND PLAN ON KEEPING FORECAST NEAR CONSENSUS DATA FOR THE TIME BEING UNTIL A BETTER FAVORED SOLUTION APPEARS...ALTHOUGH THINK WEIGHTING BLENDS A BIT MORE TOWARDS THE ECWMF IS IN ORDER BASED ON THE GEFS DATA. LATEST ECMWF HAS COME IN A BIT COOLER THAN PREVIOUS RUNS AND GIVEN EASTERLY SFC FLOW AND STRONG HIGH AROUND BASE OF SFC HIGH THINK A GENERAL COOLING TREND IS IN ORDER. WITH MOST NIGHTS NOT REALLY BRINGING A CLEAR SIGNAL FOR WARM TEMPS (DENSE CLOUD COVER...STRONG WINDS...ETC) HAVE WORKED THE 3-5 DEGREE COOLER BIAS CORRECTED SOLUTIONS INTO OVERNIGHT LOW FORECASTS WHERE I COULD...TO PICK UP OUR NORMALLY COLDEST SPOTS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1152 AM MDT MON AUG 6 2012 EXPECT PRIMARILY VFR CONDITIONS AT KGLD AND KMCK THROUGH THE EFFECTIVE PERIOD. PRIMARY QUESTION MARK WILL CENTER ON WHAT...IF ANY...IMPACT CONVECTION WILL HAVE DURING THE OVERNIGHT HOURS. GUIDANCE CONTINUES TO SUPPORT HIGHER CHANCES FOR CONVECTION AT KMCK SO WILL CONTINUE VCTS MENTION. HAVE ADJUSTED THE TIMING TO BETTER COINCIDE WITH THE HIGHEST LIKELIHOOD OF PRECIP. LEFT MENTION OF PRECIP OUT OF THE KGLD TAF GIVEN THE LOWER PROBABILITY OF A DIRECT IMPACT. WINDS WILL BECOME LIGHT AND VARIABLE LATE TONIGHT THROUGH THE END OF THE EFFECTIVE PERIOD AS A SURFACE TROUGH RESIDES OVER THE AREA. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...FOLTZ LONG TERM...JRM AVIATION...FOLTZ
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
414 PM CDT MON AUG 6 2012 .DISCUSSION... OVERVIEW...ABOVE NORMAL TEMPS EXPECTED TOMORROW BEFORE SHOWERS AND STORMS ON WEDNESDAY KICK START A COOLING TREND THAT WILL LAST THROUGH THE WEEKEND. RAIN CHANCES ON THURSDAY AND FRIDAY ARE BASED ON TWO INDEPENDENT FEATURES. INCREASED POPS DURING THIS TIME FRAME. CERTAINLY A NON ZERO CHANCE OF PRECIP TONIGHT IN WESTERN WI AND IN FAR SOUTHERN MN. A COUPLE RUNS OF THE HRRR AND THE RAP BOTH HIGHLIGHT THESE AREAS WITH SHOWERS LATE THIS EVENING. SEEING THE EFFECTS OF THE COLD FRONT STRETCHED OUT ACROSS NORTHERN MM. GETTING NEAR SURFACE CONVERGENCE SHOWING UP IN THE MESO ANALYSIS BUT ALSO PRETTY OBVIOUS JUST BASED ON THE LOW LEVEL FLOW. NICE BAND OF CUMULUS AND EVENED EMBEDDED SHOWERS VISIBLE THIS AFTERNOON. SECONDLY...SUBTLE SHORTWAVE ENERGY IN THE EASTERN DAKOTAS ALSO DROPPING SOUTH THIS AFTERNOON. NOT MUCH BEING REFLECTED IN THE SHORT TERM HEIGHT/VORTICITY FIELDS...BUT DEFINITELY SOMETHING APPARENT ON THE WATER VAPOR. IN GENERALLY...TRIMMED THE POPS BACK TONIGHT. POP VALUES WERE ALREADY LOW...IN THE 20-30%...BY LIMITED THE AREAL EXTEND OF THE POPS COMPARED TO THE PREVIOUS FORECAST. THINK A VAST MAJORITY OF THE FORECAST AREA REMAINS DRY EVEN WITH THE WEAK FRONTAL PASSAGE. WONDERING IF THE HIGH DEWPOINT BIAS OFF THE RAP IS PLAYING INTO THE EXTRA PRECIP TONIGHT. REALLY CAN NOT SEE HOW MUCH DIFFERENT TOMORROW WILL BE COMPARED TO TODAY IN TERMS OF TEMPERATURES. IT MIGHT BE A DEGREE OR TWO COOLER THAN TODAY...BUT 70-80% OF THE GUIDANCE HAS FORECAST 2M TEMPS AND 850MB TEMPS VERY SIMILAR TO WHAT WAS SEEN TODAY. STILL LOOKS GOOD FOR AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS ON WEDNESDAY WITH SHORTWAVE ROTATING AROUND THE RIDGE OVER THE NEXT 36-48HRS. SHEAR IS MARGINAL WITH RELATIVELY WEAK MID LEVEL FLOW...BUT FORCING AND INSTABILITY SHOULD NOT BE A PROBLEM...SO LIKELY POPS ARE NOT A STRETCH AT THIS POINT. WE BLEED THE POPS INTO THURSDAY DUE TO THE UPPER LOW DROPPING SOUTH OUT OF THE INTERIOR OF CANADA...NOW IN NORTH CENTRAL CANADA BETWEEN 70-75 NORTH. THIS SYSTEM HAS PROBABLY TRENDED A LITTLE BIT SLOWER AND STRONGER WITH TIME OVER THE LAST COUPLE DAYS. THERE IS NOT MUCH RECOVERY IN TERMS OF INSTABILITY...BUT COOL TEMPS ALOFT SUGGESTS SHOWERY ACTIVITY WITH EMBEDDED THUNDER. COOLED TEMPS ON THURSDAY...MIGHT BE HARD TO GET MUCH ABOVE 75 IN SOME LOCATIONS IN CENTRAL MN AND WI WITH CLOUD COVER AND SHOWERS. && .AVIATION.../18Z TAF ISSUANCE/ ONLY ITEM OF INTEREST THIS TAF PERIOD IS THE PASSAGE OF A COLD FRONT THIS EVENING...THAT SHOULD COME THROUGH WITHOUT MUCH MORE THAN A WIND SHIFT. MAIN SHORTWAVE DRIVING THIS FRONT IS GOING ACROSS LAKE SUPERIOR NOW...WHICH MEANS THERE IS LITTLE UPPER SUPPORT FOR PRECIP THIS FAR SOUTH. THIS COMBINED WITH THE STILL DRY ATMO AFTER FRIDAY NIGHTS FROPA AND WEAK CONVERGENCE ALONG THE FRONT SHOULD MAKE IT TOUGH TO GET MUCH ACTIVITY GOING. CAN NOT RULE IT OUT...BUT CONFIDENCE/COVERAGE IN PRECIP NOT HIGH ENOUGH TO INCLUDE A VC MENTION. FOR THE WIND SHIFT OVER TO THE NORTH...FOLLOWED LAV TIMING...WHICH HAS GOOD AGREEMENT WITH THE HRRR/RAP/SREF. KMSP...FRONT WILL SLIP THROUGH THE MSP AREA BETWEEN 6Z AND 8Z...WITH WINDS VEERING OVER TOWARD THE NORTH BEHIND IT. BEST SHOT FOR SEEING STORMS WOULD BE BETWEEN 5Z AND 9Z...BUT NOT EXPECTING MUCH COVERAGE IF ANYTHING DOES DEVELOPED...SO REMOVED THE VCSH. OUTSIDE OF THAT...WILL BE ANOTHER QUIET PERIOD. /OUTLOOK/ .WEDNESDAY...VFR WITH MVFR/TSRA POSSIBLE. WINDS SE AT 5-10 KTS. .THURSDAY...MVFR CLOUDS AND SHRA DURING THE DAY...BECOMING VFR OVERNIGHT. WINDS N AT 10G15 KTS. .FRIDAY...VFR. WINDS E 5-10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ CLF/MPG
AREA FORECAST DISCUSSION
NWS RALEIGH NC
320 PM EDT MON AUG 6 2012 .SYNOPSIS... AN UPPER LEVEL TROUGH APPROACHING FROM THE NORTHWEST THIS EVENING....WILL DRIFT EAST ACROSS THE CAROLINAS AND SOUTHERN VIRGINIA TONIGHT THROUGH WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 320 PM MONDAY... A WEAK COLD FRONT WEST OF THE MOUNTAINS WILL STALL FROM EASTERN TN TO NORTHERN VA THIS EVENING...WHILE THE ASSOCIATED UPPER SHEAR AXIS SLIPS EAST INTO CENTRAL NC. CONVECTION HAS DEVELOPED ALONG A DIFFERENTIAL HEATING NEAR THE NC/VA BORDER FROM WIDESPREAD CLOUD COVER THAT HAS BEEN DRIFTING ALONG AND EAST OF THE FRONTAL ZONE...AND ALSO OVER SOUTHEAST NC AND COASTAL SC. THE COVERAGE OF SHOWERS AND STORMS WILL INCREASE FROM THE WESTERN PIEDMONT TO THE NORTHERN COASTAL PLAIN BY 21Z...AND THEN SLOWLY PUSH EAST ACROSS THE PIEDMONT THIS EVENING AS THE SHEAR AXIS MOVES OVER THE AREA. MLCAPE HAS BEEN LIMITED TO LESS THAN 1000 J/KG OVER MOST OF CENTRAL NC THUS FAR...AND WEAK MID LEVEL FLOW HAS THE 0-6KM EFFECTIVE SHEAR WELL BELOW 20KT. WITH VERY LITTLE DOWNDRAFT CAPE AND SOUNDINGS BECOMING INCREASINGLY MOIST ADIABATIC DUE TO PW VALUES OF OVER 2 INCHES...THE SEVERE THREAT IS LOW THIS EVENING OUTSIDE OF A MORE INTENSE STORM WILL A PRECIP LOADED DOWNBURST. SOME MINOR FLASH FLOODING IS POSSIBLE...MAINLY IN URBAN AREAS THIS EVENING AS FLASH FLOOD GUIDANCE IS RELATIVELY HIGH AREAWIDE. TONIGHT... AS THE RIBBON OF VORTICITY ASSOCIATED WITH THE SHEAR AXIS SETTLES INTO CENTRAL NC TONIGHT...SOME OF THE CAMS ALONG WITH THE HRRR SHOW THE FOCUS FOR PRECIP SETTING UP ALONG OR JUST WEST OF US HWY 1. WEAK LAPSE RATES ALOFT AND LIMITED INSTABILITY...COVERAGE SHOULD DECREASE AFTER MIDNIGHT...BUT SCATTERED SHOWERS AND A FEW ISOLATED STORMS WILL BE POSSIBLE OVERNIGHT. LOWS IN THE LOWER 70S. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 320 PM MONDAY... THE UPPER LEVEL SHEAR AXIS AND AXIS OF HIGHER PW WILL SHIFT SLIGHTLY EAST ON TUESDAY...AND WITH IT THE FOCUS FOR GREAT COVERAGE OF SHOWERS AND STORMS. CONDITIONS WILL BE VERY SIMILAR TO TODAY WITH WEAK INSTABILITY AND SHEAR...BUT HIGH PW AND RELATIVELY SLOW MOVEMENT OF CELLS...WHICH WILL LEAD TO MAINLY AN ISOLATED FLASH FLOODING THREAT. ONE FEATURE TO NOTE IS AN AREA OF CONVECTION OVER THE FL PANHANDLE AND ITS ASSOCIATED VORT MAX...WHICH MODELS SHOW BEING DRAWN NORTH ACROSS GA AND SC ON TUESDAY. THE GFS HAS THE MOST AGGRESSIVE NORTHWARD TRACK AND BRINGS IT ACROSS THE NC COASTAL PLAIN LATE TUESDAY NIGHT INTO WEDNESDAY. HOWEVER...THERE IS TOO MUCH MODEL SPREAD TO PUT MUCH FAITH IN HOW IT MIGHT IMPACT CONVECTION TUESDAY NIGHT. FOR NOW...WE WILL CONTINUE TO SHOW 70-80 POPS ACROSS THE EAST TUESDAY AFTERNOON...TRENDING DOWNWARD TUESDAY NIGHT BUT WITH AT LEAST CHANCE POPS OVERNIGHT. UNDER MORE WIDESPREAD CLOUD COVER...HIGHS SHOULD BE A FEW DEGREES COOLER THAN TODAY...AND MOST GUIDANCE GIVES LOW TO MID 80S. LOWS TUESDAY NIGHT IN THE UPPER 60S TO LOWER 70S. WEDNESDAY THROUGH THURSDAY NIGHT: THE MID/LOW LEVEL TROUGH WEAKENS AND STALLS OVER THE EAST COAST ON WEDNESDAY...BRINGING THE BEST CHANCES FOR PRECIP FROM THE COASTAL PLAIN EASTWARD. THE REMNANTS OF THE SURFACE TROUGH WILL MOVE OFFSHORE WEDNESDAY NIGHT AND THURSDAY AHEAD OF OUR NEXT LOW PRESSURE/FRONTAL SYSTEM. THIS SHOULD YIELD A BREAK IN THE PRECIPITATION WEDNESDAY NIGHT AND INTO THURSDAY...WITH MORE SHOWERS AND THUNDERSTORMS POSSIBLE THURSDAY AFTERNOON AND INTO THURSDAY NIGHT. HAVE TRENDED MORE TOWARD THE MAV FOR TEMPS...HIGHS WEDNESDAY IN THE MID 80S WITH LOWS OVERNIGHT IN THE UPPER 60S TO LOW 70S. HIGHS THURSDAY SLIGHTLY WARMER...MID TO UPPER 80S WITH OVERNIGHT LOWS IN THE LOW 70S && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 320 PM MONDAY... A COLD FRONT ASSOCIATED WITH AN ANOMALOUSLY STRONG LOW PRESSURE SYSTEM WILL IMPACT CENTRAL NC AT THE END OF THE WEEK. THE UPPER LEVEL LOW IS EXPECTED TO DEVELOP OVER CANADA ON WEDNESDAY AND TRACK SOUTH AND EAST THROUGH MICHIGAN EARLY FRIDAY AND DEEPEN AS IT MOVES OVER THE GREAT LAKES INTO THE WEEKEND. HAVE MAINLY GONE WITH A BLEND OF THE ECMWF AND THE 12Z GFS AS THEY ARE IN FAIRLY GOOD AGREEMENT AND SEEM TO HANDLE THE LOW PRESSURE SYSTEM THE BEST. THE COLD FRONT ASSOCIATED WITH THIS SYSTEM SHOULD MOVE INTO THE AREA AROUND MID DAY FRIDAY...BRINGING WITH IT THE POTENTIAL FOR STRONG TO SEVERE STORMS TO DEVELOP. THE 12Z GFS GENERATES 1500-2000 J/KG OF SURFACE BASED CAPE OVER CENTRAL NC FRIDAY AFTERNOON...0-6 KM BULK SHEAR VALUES OF 30-40 KTS...MID LEVEL LAPSE RATES OF 6-7 DEGREES C/KM...AND PRECIPITABLE WATER VALUES OVER 2 INCHES. BOTH MODELS SHOW THE MAIN PRECIP AXIS MOVING THROUGH CENTRAL NC FROM THE NW THROUGH APPROX 12Z SATURDAY. THE FRONT COULD THEN LINGER OVER THE COAST THROUGH THE END OF THE WEEKEND...LEADING TO A CONTINUED CHANCE FOR SHOWERS AND STORMS OVER THE COASTAL PLAIN DURING THAT TIME. EXPECT HIGHS IN THE MID TO UPPER 80S THROUGH SUNDAY...WITH SLIGHTLY COOLER TEMPS FOR MONDAY...LOW TO MID 80S. OVERNIGHT LOWS RANGING FROM THE UPPER 60S TO LOW 70S THROUGH THE END OF THE PERIOD. && .AVIATION /18Z MONDAY THROUGH FRIDAY/... AS OF 140 PM MONDAY... MOSTLY 3-4K FT CEILINGS ARE CURRENTLY OBSERVED ACROSS CENTRAL NC WITH A FEW AREAS OF SHOWERS AND ISOLATED THUNDERSTORMS NEAR KGSO/KINT AND NORTH OF KRDU. A COLD FRONT WILL PUSH INTO WESTERN NC THIS EVENING BUT CONTINUE TO WEAKEN AND WASH OUT OVER CENTRAL NC BY TUESDAY. SHOWERS AND STORMS ARE EXPECTED TO BECOME MORE NUMEROUS ALONG THE WEAK FRONT. WHERE SHOWERS ARE HEAVIEST...STRONG GUSTY WINDS AND IFR...OR LOWER.... CEILINGS/VSBYS WILL BE POSSIBLE. THE TIMING OF THESE SHOWERS AND STORMS IS DIFFICULT TO PIN DOWN...BUT THE BEST TIME FRAME APPEARS AFTER 20Z TODAY AND INTO THE OVERNIGHT HOURS...POSSIBLY DIMINISHING FROM WEST TO EAST AFTER MIDNIGHT. IFR CEILINGS MAY THEN DEVELOP BY 09Z...WITH MODELS SHOWING THE GREATEST PROBABILITY AT KGSO AND KINT. SHOWERS AND STORMS ARE EXPECTED TO DEVELOP ALONG THE REMNANTS OF THE FRONT ON TUESDAY...WITH THE GREATEST COVERAGE OVER EASTERN NC. ANY MORNING STRATUS SHOULD LIFT BUT MAY HOLD AT OR JUST BELOW 3K FT GIVEN THE MOIST AIRMASS IN PLACE. OUTLOOK... THE THREAT FOR SCATTERED...MAINLY AFTERNOON AND EVENING SHOWERS AND T-STORMS...WILL RETURN THURSDAY AND FRIDAY. IN ADDITION THERE WILL BE THE LIKELIHOOD OF SUB-VFR FOG AND CEILINGS DURING THE PRE-DAWN THROUGH EARLY MORNING HOURS EACH DAY. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...WSS NEAR TERM..SMITH SHORT TERM...SMITH/KMC LONG TERM...SMITH AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
305 PM EDT MON AUG 6 2012 .SYNOPSIS... A FRONT WILL REMAIN STATIONARY TO THE NORTHWEST OF THE REGION...AND THIS WILL ALLOW FOR A MOIST AND UNSTABLE AIR MASS TO REMAIN IN PLACE THROUGH THE END OF THE WEEK. A SECOND FRONT WILL APPROACH THE AREA AND BECOME STATIONARY ALONG THE COAST THIS WEEKEND. THERE IS A CHANCE OF THUNDERSTORMS AND SHOWERS EACH DAY WITH THE BEST CHANCES ARE TUESDAY AND THIS WEEKEND. && .NEAR TERM /THROUGH 6 AM TUESDAY/... AS OF 300 PM MONDAY...THE FORECAST SETUP IS QUITE SIMILAR TO YESTERDAY. SURGE OF TROPICAL MOISTURE HAS LEAD TO A BAND OF SHOWERS ALONG THE COAST...MAINLY INITIATED BY LL CONVG. THIS AREA OF RAIN IS BEING ADVECTED FURTHER INLAND WHILE CELL MOTION IS TO THE NORTHEAST. THE ACTUAL SEABREEZE HAS HAD VERY WEAK RADAR SIGNATURE TODAY AND IS BETTER DEMARCATED IN VIS SAT IMAGERY...TO THE EAST OF WHICH CLOUD COVER IS VERY MUCH DECREASED. SIMILAR TO YESTERDAY THE VERY NEAR TERM FORECAST WILL SHOW THE WET WEATHER CONTINUE TO DRIFT WESTWARD AND START TO DIMINISH WITH THE DIURNAL CYCLE. THE HRRR PERFORMED QUITE WELL YESTERDAY AND HAS THIS LINE BECOME MUCH MORE BROKEN BY 22Z AND EVEN MORESO TOWARDS SUNSET. SOME QUESTION AS TO WHETHER OR NOT PRECIP DEVELOPS OVER WATER DURING THE OVERNIGHT HOURS. MODEL GUIDANCE NOT TOO EXCITED ABOUT THE PROSPECT BUT THE SLIGHT CHANCE POPS FROM THE PREVIOUS FORECAST SEEMS PLAUSIBLE ENOUGH. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...WITH STATIONARY FRONT BACK TO THE WEST AND DEEP MOISTURE IS IN PLACE OVER THE AREA...CONDITIONS CONTINUE TO FAVOR A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS OVER THE REGION TUESDAY AND WEDNESDAY. THE MODELS ARE INDICATING A SHORT WAVE TO CROSS THE REGION ON TUESDAY AND WITH THIS LIFT SHOULD ENTICE THE DEVELOPMENT OF RAIN FOR THE ENTIRE COUNTY WARNING AREA. THE MEAN STORM MOTION IS FROM THE SOUTHWEST JUST BELOW 10 KNOTS AND WITH SOME HEAVY DOWNPOURS EXPECT THE FLOW MAYBE QUICK ENOUGH TO HOLD OFF THE CHANCES FOR ANY TYPE OF FLOODING ON TUESDAY. THE SOUTHWEST WINDS ALOFT PATTERN HOLDS UP INTO WEDNESDAY SO EXPECT CHANCES OF RAIN TO CONTINUE. TEMPERATURES ARE EXPECTED REMAIN IN THE MID TO UPPER 80S AND LOWS IN THE MIDDLE 70S. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 3 PM MONDAY...PATTERN ALOFT WILL REMAIN AMPLIFIED THROUGH THE PERIOD WITH RIDGING OVER THE WEST AND TROUGHING OVER THE EAST. EARLY IN THE PERIOD TROUGHING IS ON THE WEAK SIDE...BUT IMPRESSIVE SHORTWAVE DROPPING DOWN THE EAST SIDE OF THE WESTERN RIDGE WILL DRIVE A COLD FRONT INTO THE SOUTHEAST AND HELP AMPLIFY THE 5H TROUGH OVER THE WEEKEND. WITH 5H TROUGH AXIS REMAINING OVER THE OH AND TN VALLEYS GULF MOISTURE WILL CONTINUE TO STREAM INTO THE REGION. COLD FRONT STALLS ACROSS THE AREA SUN THEN STARTS TO WASH OUT MON. DEEP MOISTURE...DIVERGENCE ALOFT...DIURNAL HEATING...AND CONVERGENCE ALONG THE SEA BREEZE AND PIEDMONT TROUGH/COLD FRONT WILL KEEP A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE PERIOD. HIGHEST POP DURING THE PERIOD WILL LIKELY BE SAT...THOUGH WEAK SHORTWAVES THU AND/OR FRI COULD PRODUCE SIGNIFICANT COVERAGE. TEMPERATURES WILL BE WITHIN A DEGREE OR TWO OF CLIMO THROUGH THE PERIOD. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 18Z...CONVECTION FIRING ALONG THE RESULTANT THAT WILL PUSH WESTWARD WITH TIME...SLOWER THAN YESTERDAY DUE TO THE SOUTHWEST FLOW ALOFT. LOOK FOR THE SHOWERS AND ISOLATED THUNDERSTORMS TO END AROUND 22Z...WITH MAINLY VFR CONDITIONS EXPECTED THROUGH THE OVERNIGHT HOURS. TIME HEIGHT INDICATES MID AND HIGH CLOUDS WILL BE ON THE INCREASE AS A FRONTAL BOUNDARY THAT HAS BEEN JUST WEST OF THE REGION FOR SEVERAL DAYS FINALLY MOVES IN. TUESDAY...AGAIN A MID OR HIGH CLOUD CEILING WITH SCATTERED CONVECTION AROUND. MAINLY SOUTHWEST FLOW THROUGH THE PERIOD...MORE SOUTHERLY ALONG THE COAST. EXTENDED OUTLOOK...MVFR/IFR VSBYS AND LOW CEILINGS FROM BR/FG POSSIBLE EACH MORNING WITH DAILY THREAT FOR DIURNALLY DRIVEN CONVECTION EACH DAY. && .MARINE... AS OF 1030 AM MONDAY/THROUGH TONIGHT/...THE PRESSURE GRADIENT OVER THE LANDMASS WILL BE QUITE LIGHT THROUGH THE PERIOD. HIGH PRESSURE ACROSS THE WEST AND CENTRAL ATLANTIC WILL STILL BE THE DOMINANT WIND AND WAVE MAKER THEN. A SOUTH TO SOUTHWESTERLY WIND WILL BE CAPPED AT JUST 10KT. WIND WAVES IN THE 2 TO 3 FT RANGE WILL BE COMPRISED OF BOTH THE LIGHT WIND WAVE AND SOME 9 SEC SWELL ENERGY. SHORT TERM /6 AM TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...SOUTH TO SOUTHWEST WINDS OF 10 TO 15 KNOTS WILL CONTINUE OVER THE WATERS THROUGH THE PERIOD AS A STATIONARY FRONT REMAINS INLAND THROUGH THE PERIOD. SEAS WILL REMAINS AROUND 3 FEET WITH AN INCREASE TO 4 TO 5 FEET AT 20 MILES OFF THE COAST LATE WEDNESDAY EVENING. THIS WILL BE RELATED TO AN INCREASE IN THE SOUTHERLY WINDS. LONG TERM /THURSDAY THROUGH SATURDAY/... AS OF 3 PM MONDAY...SOUTHWEST FLOW CONTINUES THROUGH THE PERIOD...THOUGH WITH SPEEDS INCREASING AS A COLD FRONT APPROACHES THE REGION FROM THE NORTHWEST. WINDS 10 TO 15 KT THU INTO THU NIGHT INCREASE TO 15 TO 20 FRI AND FRI NIGHT AS GRADIENT TIGHTENS UP AND LOW LEVEL JET DEVELOPS. FRONT MOVES INTO THE REGION SAT RELAXING PRESSURE GRADIENT AND SHIFTING STRONGEST LOW LEVEL JETTING NORTH AND EAST. THIS WILL ALLOW WINDS TO DROP BACK CLOSER TO 15 KT. SEAS 2 TO 4 FT THU WILL BUILD WITH INCREASING WINDS FRI AND FRI NIGHT. ISOLATED 6 FT MAY DEVELOP WELL AWAY FROM THE COAST. HEADLINES ARE POSSIBLE FOR BOTH FRI AND FRI NIGHT...BUT LOW CONFIDENCE WHETHER IT WILL BE SCA OR SCEC. REDUCTION IN WINDS SAT/SAT NIGHT ALLOWS SEAS TO DROP BACK INTO THE 2 TO 4 FT RANGE WITH SOME ISOLATED 5 FT POSSIBLE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...REK/MBB SHORT TERM...HAWKINS LONG TERM...III AVIATION...DL
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
305 PM CDT MON AUG 6 2012 .SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)...CONVECTION THIS AFTERNOON HAS DIMINISH AS THE SEA-BREEZE MOVES INLAND. MAIN THINKING IS THAT THE BEST DYNAMICS REMAIN TO THE SOUTH WHERE A STRONGER VORTICITY MAX SHOWS UP IN THE RUC ANALYSIS...AND BIT STRONGER CAP IS HOLDING ON ACROSS OUR REGION. WITH THE LOSS OF HEATING LATE THIS EVENING...PRECIPITATION WILL REMAIN LOW AND HAVE KEPT MENTION OUT OF THE FORECAST. DECENT MOISTURE IN PLACE EXPECTED TO STAY AROUND FOR TOMORROW TO KEEP SLIGHT CHANCE OF PRECIPITATION...BEGINNING OVER THE COASTAL WATERS TUESDAY MORNING THEN AFTERNOON CONVECTION AGAIN FOR THE AFTERNOON HOURS. COULD SEE A BIT OF LOWER VISIBILITIES WILL BE POSSIBLE JUST BEFORE SUNRISE GIVEN THE LIGHT WINDS...HIGH DEW POINT VALUES AND GENERALLY CLEAR SKIES. HOWEVER...CONFIDENCE REMAINS LOW ON FOG DEVELOPMENT OVERNIGHT. AFTERNOON TEMPERATURES WILL ONCE AGAIN RUN ABOVE GUIDANCE/SEASONAL AVERAGES. OVERALL...A PERSISTENT FORECAST FROM WHAT WE HAVE SEE THE PAST FEW DAYS...JUST A BIT LESS IN THE WAY OF CONVECTION WITH LACK OF MID/UPPER LEVEL SUPPORT. && .LONG TERM (WEDNESDAY THROUGH MONDAY)...CONCUR WITH THE DETERMINISTIC GFS/ECMWF AND GFS ENSEMBLE MEAN THAT THE UPPER RIDGE WILL CONTINUE TO MOVE TOWARD THE NW BEFORE BECOMING QUASI- STATIONARY. SUFFICIENT MOISTURE/INSTABILITY WILL CONTRIBUTE TO ISOLD CONVECTION PRIMARILY OVER THE NERN SECTIONS/ADJACENT MSA WEDNESDAY/THURSDAY. THE FOREGOING MODELS PROG AN UPPER DISTURBANCE TO MOVE ACRS THE CNTRL/NRN PLAINS WEDNESDAY/THURSDAY WHICH WILL CONTRIBUTE TO A WEAK FRONTAL BOUNDARY WHICH MAY ENTER CNTRL/SRN TX FRIDAY/SATURDAY (ALONG WITH ASSOCIATED HIGH PW VALUES OWING TO MSTR CONVERGENCE.) FURTHER...BASED ON THE CURRENT ERNESTO FCST TRACK... THE NRN EDGE OF COPIOUS MSTR FROM ERNESTO EXPECTED TO ENTER THE CWA/MSA COMMENCING LATE THURSDAY. THUS WILL MAINTAIN AT LEAST ISOLD CONVECTION FRIDAY/SATURDAY. NOT CONFIDENCE ENOUGH TO FCST PCPN SUNDAY/MONDAY. NO SIGNIFICANT CHANGE TO TEMPS DRG THE PERIOD EXCEPT FOR SLIGHT DECREASE IN RESPONSE TO ERNESTO MSTR. ANTICIPATE MAX HEAT INDEX VALUES AROUND 105F DRG THE PERIOD. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 75 96 77 95 75 / 10 20 10 10 10 VICTORIA 73 95 75 95 74 / 10 20 10 20 10 LAREDO 78 102 79 102 79 / 10 10 10 10 10 ALICE 74 100 74 99 74 / 10 20 10 10 10 ROCKPORT 79 91 79 89 78 / 20 20 10 20 10 COTULLA 74 101 75 101 75 / 10 10 10 10 10 KINGSVILLE 74 98 76 97 75 / 10 20 10 10 10 NAVY CORPUS 79 90 80 88 80 / 10 20 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ RG/82...SHORT TERM WC/87...LONG TERM
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1221 PM CDT MON AUG 6 2012 .AVIATION... CONCERNS THROUGH SUNSET WILL BE ISOLATED STORM DEVELOPMENT AND BACKING OF WINDS FROM WSW TO SELY BY 00Z TUESDAY. WEAK SHORTWAVE CONTINUES TO DROP SWD ACROSS E TX WITH A WEAKENING MORNING STORMS OCCURRING BETWEEN KSLR AND KPSN. ALL TERMINALS ARE JUST OUTSIDE OF THE HIGH CLOUD CANOPY WILL LIKELY SEE DIFFERENTIAL HEATING AND AGEOSTROPHIC LIFTING PROCESSES AS THE AFTERNOON PROGRESSES. THERE ARE INDICATIONS FROM THE RAP AND NORMAN WRF MODELS THAT ISOLATED STORMS WILL BECOME MORE EVIDENT BY MAX HEATING OR MID AFTERNOON. WITH A VERY MOIST AND TROPICAL AIRMASS IN PLACE...PRECIP LOADING COULD RESULT IN GUSTY DOWNBURSTS IN EXCESS OF 40 KTS POSSIBLE. ONLY DIFFERENCE IS WACO WILL LIKELY SEE THEIR BEST POTENTIAL LATER IN DAY...BETWEEN 21Z-01Z. OTHERWISE...VFR FORECAST CONTINUES WITH LIGHT SWLY FLOW BECOMING SELY BY SUNSET...THEN SWLY BY DAYBREAK TUESDAY. 05/ && .UPDATE... A WEAK BOUNDARY REMAINS ACROSS THE NORTHEASTERN ZONES AT MIDDAY. THE MAIN CHANGE TO THE FORECAST WAS TO ADD ISOLATED THUNDERSTORMS TO THE WEST WHERE THE HIGH RESOLUTION RAPID REFRESH IS SHOWING SOME THUNDERSTORM DEVELOPMENT LATER THIS AFTERNOON. HAVE ALSO ADJUSTED THE HOURLY TEMPERATURES IN THE NORTHEAST WHERE CLOUD COVER AND EARLIER PRECIPITATION HAVE SLOWED THE WARM UP. 58 && .PREV DISCUSSION... /ISSUED 413 AM CDT MON AUG 6 2012/ NORTH TO NORTHWEST FLOW ALOFT WILL REMAIN OVER NORTH TEXAS THROUGH THE WEEK AS UPPER LEVEL HIGH PRESSURE REMAINS CENTERED NEAR THE FOUR CORNERS REGION. THIS PATTERN WILL RESULT IN SEASONALLY HOT TEMPERATURES AND SOME LOW RAIN/THUNDERSTORM CHANCES THROUGH MUCH OF THE WEEK. A WEAK COLD FRONT THAT HAD MOVED INTO NORTH TEXAS ON SUNDAY WAS LOCATED NEAR A SHERMAN TO SULPHUR SPRINGS LINE EARLY THIS MORNING. THIS FRONT IS PROGGED TO SLOWLY BACKDOOR THE EASTERN COUNTIES OF NORTH TEXAS THROUGH TUESDAY. THE FRONT WILL CONTINUE TO ACT AS A FOCUSING MECHANISM FOR SCATTERED SHOWERS AND THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON AND EVENING HOURS. THERE IS ALSO A SMALL CHANCE THAT SOME SHOWERS AND THUNDERSTORMS COULD MOVE ACROSS THE WESTERN AND NORTHERN PORTIONS OF NORTH TEXAS DURING THE OVERNIGHT/MORNING HOURS TONIGHT THROUGH THURSDAY MORNING...AS AFTERNOON CONVECTION ACROSS THE CENTRAL PLAINS MOVES SOUTH/SOUTHEAST DURING THE OVERNIGHT HOURS. FOR NOW WE WILL KEEP ALL POPS LOW WITH ONLY WEAK FORCING EXPECTED AND A VERY DRY SOLUTION FROM THE ECMWF. UPPER LEVEL HIGH PRESSURE WILL BUILD BACK TO THE EAST BY THE WEEKEND WHICH SHOULD DECREASE RAIN CHANCES DUE TO INCREASED LARGE SCALE SUBSIDENCE. HIGH TEMPERATURES THROUGH THE WEEK WILL RANGE FROM THE MIDDLE 90S TO AROUND 101 WITH OVERNIGHT LOWS FROM THE MIDDLE 70S TO NEAR 80. THE ONLY LOCATIONS THAT WILL SEE AFTERNOON HEAT INDEX VALUES UP TO 106 WILL BE THE EASTERN ZONES DUE TO SLIGHTLY BETTER MOISTURE. THEREFORE...WILL KEEP THE HEAT ADVISORY THROUGH TUESDAY JUST FOR THE EXTREME EASTERN COUNTIES OF NORTH TEXAS. HOWEVER...OVERNIGHT LOWS MAY BE SLIGHTLY SHY OF REACHING CRITERIA IN SOME SPOTS. 79 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 102 80 101 79 101 / 20 20 10 20 20 WACO, TX 100 77 102 80 100 / 20 20 10 10 20 PARIS, TX 98 76 99 75 98 / 20 20 10 10 20 DENTON, TX 102 77 102 76 101 / 20 10 10 20 20 MCKINNEY, TX 99 76 99 76 99 / 20 20 10 20 20 DALLAS, TX 101 82 101 80 100 / 20 20 10 20 20 TERRELL, TX 100 76 100 76 98 / 20 20 20 20 20 CORSICANA, TX 100 76 100 76 99 / 20 20 20 10 20 TEMPLE, TX 101 76 100 76 99 / 20 10 10 20 20 MINERAL WELLS, TX 101 78 101 78 102 / 10 20 20 20 20 && .FWD WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR TXZ107-122-123-135- 146>148-160>162-174-175. && $$ 05/58
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 PM CDT MON AUG 6 2012 .SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT 305 PM CDT MON AUG 6 2012 MAIN FORECAST CHALLENGES ARE ON RAIN CHANCES TONIGHT AND EARLY TUESDAY AND AGAIN WEDNESDAY THROUGH THURSDAY. 18Z SURFACE ANALYSIS SHOWS HIGH PRESSURE STRETCHING FROM NORTHERN ILLINOIS INTO SOUTHERN LOWER MICHIGAN. VISIBLE SATELLITE IMAGERY SHOWING CLEAR SKIES ACROSS THE ENTIRE UPPER MIDWEST AND GREAT LAKES REGION. 06.12Z MODELS OFFER SIMILAR SOLUTIONS THROUGH THE PERIOD. IN THE NEAR TERM...SHORTWAVE TROUGH WILL ROTATE ACROSS LAKE SUPERIOR TONIGHT...PUSHING A WEAK SURFACE TROUGH THROUGH THE FORECAST AREA. MODELS SHOWING LOW LEVELS TO REMAIN RELATIVELY DRY WITH MOISTURE AT OR ABOVE 800MB. MID LEVEL INSTABILITIES IN THE ORDER OF 400 J/KG TO 800 J/KG ARE PROGGED OVER THE AREA AS THE TROUGH DROPS SOUTHWARD OVERNIGHT. 06.12Z NAM GOING DRY TONIGHT...WHILE GFS SHOWS SOME LIGHT QPF. VARIOUS MESO MODELS ALSO DIFFERING...WITH THE 06.14Z HRRR DEVELOPING CONVECTION IN THE HIGHER CAPE AREA OVER CENTRAL SOUTHERN MINNESOTA AND THE 06.12 NMM EAST KEEPING THINGS DRY UNTIL AFTER 09Z. WITH THESE DIFFERENCES WILL CONTINUE THE LOWER END PROBABILITIES FOR TONIGHT AND JUST ACROSS THE SOUTH ON TUESDAY. HIGH PRESSURE THEN BUILDS ACROSS THE AREA TUESDAY NIGHT...BUT THIS WILL BE QUITE TRANSITORY AS NEXT SHORTWAVE IN THE NORTHWEST FLOW DROPS QUICKLY THROUGH THE DAKOTAS AND THIS WILL SPREAD SOME MID AND HIGH LEVEL CLOUDS INTO THE AREA AFTER MIDNIGHT...BUT THE AREA WILL REMAIN DRY. MODELS HAVE BEEN PRETTY CONSISTENT IN THE WEDNESDAY THROUGH THURSDAY TIME FRAME. MID LEVEL TROUGH DIGS ACROSS THE UPPER MISSISSIPPI RIVER VALLEY REGION...WITH AN INCREASE IN MOISTURE TRANSPORT INTO THE AREA. ISENTROPIC LIFT INCREASES LATE WEDNESDAY...WITH THE MAIN RAIN CHANCES WEDNESDAY NIGHT. GFS INDICATING BETTER INSTABILITIES TO REMAIN TO THE SOUTH OF THE AREA. LIFT CONTINUES FOR MUCH OF THURSDAY AS TROUGH AXIS REMAINS JUST WEST OF THE AREA. SYSTEM THEN BEGINS TO PULL AWAY THURSDAY NIGHT AS HIGH PRESSURE BEGINS TO BUILD SOUTHWARD. .LONG TERM...FRIDAY THROUGH MONDAY 305 PM CDT MON AUG 6 2012 NORTH TO NORTHWEST FLOW WILL CONTINUE ACROSS THE AREA THROUGH THE PERIOD. EXITING TROUGH WILL CONTINUE TO DEEPEN OVER THE GREAT LAKES AND MOVE EASTWARD FRIDAY INTO SATURDAY...WHILE HIGH PRESSURE DOMINATES THE WEATHER FOR THE LOCAL AREA. THE HIGH WILL SLIDE OFF TO THE EAST SATURDAY NIGHT...ALLOWING FOR MOISTURE RETURN ON ITS BACKSIDE AHEAD OF THE NEXT SHORTWAVE/SURFACE TROUGH. GFS MUCH DEEPER WITH THIS FEATURE...WHILE 06.12Z ECMWF IS MUCH WEAKER AND EVEN DRY IN ITS QPF FIELDS. SYSTEM THEM DROPS SOUTH WITH QUIET WEATHER EXPECTED INTO MONDAY. WITH THE NORTHWEST FLOW...TEMPERATURES WILL BE RATHER PLEASANT AVERAGING AT OR BELOW NORMAL. && .AVIATION... 600 PM CDT MON AUG 6 2012 THERE APPEARS TO BE TWO FOCUSES FOR AN ISOLATED SHRA/TS TONIGHT. FIRST IS NORTH WITH A SFC FRONT/TROUGH MOVING SOUTHWARD ACROSS THE REGION. SOME FRONTOGENETIC FORCING AND WEAK MLCAPE AROUND THE BOUNDARY. DECENT PUSH OF 850 MB MOISTURE VIA THE RAP. THE HRRR AND NAM12 POP SOME CONVECTION ALONG THE BOUNDARY...BUT ITS MOSTLY CONFINED ACROSS NORTHERN WI TONIGHT. THE OTHER FOCUS IS ANOTHER SFC BOUNDARY WITH ACCOMPANYING LOW AROUND THE IA/MN BORDER. SOME 900-700 MB FRONTOGENETIC FORCING INDICATED IN THE RAP...ALONG WITH MLCAPES UPWARDS OF 3000 J/KG THIS EVENING. THE HRRR AND NAM12 ALSO DEVELOP SOME ISOLATED SHRA/TS DUE TO THIS FORCING...AND THIS ACTIVITY WOULD HAVE THE BETTER CHANCE OF IMPACTING KRST/KLSE. IT SHOULD BE NOTED THAT MOST OF THE SATURATION INDICATED FOR THE FORCING TO WORK ON IS MOSTLY MID TO UPPER LEVEL. BASES ON ANY SHRA/TS COULD BE 8-10 KFT. RELATIVELY DRY NEAR SFC LAYER COULD ENHANCE ANY GUSTINESS AROUND A STORM...OTHERWISE IMPACTS VIA CIGS/VSBY LOOK MINIMAL AT THIS TIME. CONFIDENCE NOT HIGH...BUT ENOUGH SUPPORT FROM THE VARIOUS MESO MODELS TO CONTINUE THE VCSH MENTION AT KRST/KLSE FOR A PERIOD TONIGHT. FRONT TO THE NORTH WILL SLIDE THROUGH TUE MORNING...SWITCHING THE WINDS TO THE NORTHWEST. HIGH PRESSURE WILL FOLLOW IN ITS WAKE...WITH QUIET VFR CONDITIONS THEN INTO TUE NIGHT. && .ARX WATCHES/WARNINGS/ADVISORIES... 305 PM CDT MON AUG 6 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...JLR LONG TERM....JLR AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
321 PM CDT MON AUG 6 2012 .SHORT TERM... TONIGHT...FORECAST CONFIDENCE MEDIUM INFLUENCE OF SURFACE HIGH WANES WITH SURFACE TROUGH APPROACHING FROM NRN MN. CLEAR FOR MUCH OF THE NIGHT. 4 KM WRF MODEL NUDGES PRECIP FROM SE MN INTO EXTREME SW WI LATE TONIGHT AS DOES GFS...THOUGH FOCUSING BOUNDARY STILL BACK TO THE NORTHWEST. LOSS OF HEATING WILL BE A FACTOR IN SUSTAINING ANYTHING INTO OUR AREA. HOWEVER UPPER FLOW UPPER FLOW IS SWIFT AND CYCLONIC FROM THE NORTHWEST WITH RUC SHOWING A 15 UNIT VORT MAX/JET STREAK IN CENTRAL MN. BUT AGAIN AIRMASS IS SO VERY DRY AND ONLY SLIGHTLY UNSTABLE ALOFT...SO WILL GO WITH A DRY FORECAST FOR NOW. TUESDAY...FORECAST CONFIDENCE MEDIUM NW UPPER FLOW CONTINUES WITH ONLY WEAK LOBES NOTED. WEAK FRONTOGENETICAL FORCING NOTED WITHIN THE LAYER WHERE LIMITED MOISTURE AND BASE OF ELEVATED CAPE RESIDE. REALLY CANNOT COMPLETELY RULE OUT ISOLATED DEVELOPMENT...SO VERY SMALL CHANCES SEEM OK. 925 TEMPS 24-26C SO TOASTY TOMORROW WITH AMPLE SUNSHINE. TUESDAY NIGHT THROUGH THURSDAY NIGHT...FORECAST CONFIDENCE MEDIUM A WEAK HIGH PRESSURE RIDGE WILL BUILD INTO SRN WI FROM THE NORTH FOR TUE NT AND WED. HOWEVER CLOUDS WILL INCREASE WED AFTERNOON AS A SHORTWAVE TROUGH WITHIN NW FLOW ALOFT MOVES TO NRN IA BY 00Z THU WITH A DEVELOPING WARM FRONT ALONG THE MN/IA BORDER. THE SHORTWAVE TROUGH WILL THEN PASS INTO IL WED NT WITH A WAVE OF LOW PRESSURE TO MOVE FROM MN TO ERN IA IN RESPONSE TO A MUCH STRONGER UPPER TROUGH DIGGING SWD FROM CANADA. THE WAVE OF LOW PRESSURE WILL THEN LIKELY TRACK ACROSS IL ON THU WITH THE UPPER LOW MOVING SEWD ACROSS WI. WITH THE ORGANIZED LOW PRESSURE AREA THERE WILL BE DECENT SFC-850 MB FRONTOGENESIS WITH PWS INCREASING TO 1.3-1.5 INCHES. MODELS DO DIFFER ON TIMING...STRENGTH AND PLACEMENT OF THE AFOREMENTIONED FEATURES BUT STILL ENOUGH CONFIDENCE FOR HIGH CHANCE TO LIKELY POPS FOR WED NT AND THU WITH LINGERING POPS THU NT. .LONG TERM... FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM THE UPPER LOW WILL MOVE AWAY FOR FRIDAY WITH NLY WINDS WEAKENING. A WEAK NW FLOW ALOFT WILL THEN PREVAIL THROUGH THE PERIOD WITH SFC HIGH PRESSURE AND DRY CONDITIONS OVER THE REGION. TEMPS WILL BE NEAR NORMAL. && .AVIATION/00Z TAFS/...VFR THROUGH THE FORECAST PERIOD. SOME MID CLOUDS LATE TONIGHT/TUESDAY MORNING AS SURFACE TROUGH APPROACHES. WILL LEAVE MENTION OR SHRA/TSRA DUE TO LOW CONFIDENCE OF OCCURRENCE AND LIKELY ISOLATED AREAL COVERAGE. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TONIGHT/TUESDAY AND AVIATION/MARINE...COLLAR TUESDAY NIGHT THROUGH MONDAY...GEHRING