Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/26/13


AREA FORECAST DISCUSSION
NWS EUREKA CA
353 AM PDT WED APR 24 2013 .SYNOPSIS...HIGH PRESSURE WILL MAINTAIN DRY WEATHER THROUGH THE WEEK. COASTAL STRATUS ALONG THE MENDOCINO COAST WILL MOVE NORTH IMPACTING THE REDWOOD COAST BY LATE THIS AFTERNOON AND EVENING. && .DISCUSSION...SAT IMAGERY SHOWS STRATUS EXPANDING SLOWLY N ALONG THE MENDO COAST JUST MOVG INTO SHELTER COVE ATTM. MAIN FCST CHALLENGE WILL BE TIMING STRATUS SURGE AROUND CAPE MENDO AND COASTAL TEMPS TODAY. MODELS CONTINUE TO INITIALIZE STRATUS AND SLY WINDS POORLY ALTHOUGH LATEST COUPLE OF RUNS OF HRRR BECMG MORE CONSISTENT WITH SAT IMAGERY. NLY GRADIENT CONTINUES WITH BUOY22 REPORTING 20G30KT WINDS. EXPECT STRATUS TO REMAIN S OF CAPE MENDO THROUGH THE MORNING. NLY GRADIENT WILL EASE THIS AFTERNOON ALLOWING STRATUS TO ROUND THE CAPE AND SURGE N ALONG THE REDWOOD COAST. COASTAL TEMPS WILL BE SLIGHTLY COOLER N OF CAPE MENDO AS OFFSHORE FLOW AND DOWNSLOPING EFFECTS WILL BE LESS. NIGHT/MORNING STRATUS WILL CONTINUE TO IMPACT COASTAL AREAS WHILE ABOVE NORMAL TEMPS CONTINUE ACROSS THE INTERIOR. MODELS CONTINUE TO SHOW ANOTHER WEAK SYSTEM IMPACTING THE PAC NW THIS WEEKEND...BUT LATEST RUNS KEEP PRECIP N OF THE OR BORDER WITH MAIN IMPACT BEING COOLER TEMPS ACROSS THE INTERIOR. && .AVIATION...FOG SATELLITE SHOWS STRATUS ALONG THE COAST, SURGING FROM THE SOUTH. AS IT HITS THE REDWOOD COAST DURING THE MORNING AND AFTERNOON IT WILL BRING REDUCED CONDITIONS TO THE COASTAL AIRSTRIPS. INLAND...VFR IS EXPECTED TO PREVAIL. && .MARINE...NORTHERLY WINDS WILL EASE TODAY AND WAVES WILL SUBSIDE AS THE PRESSURE GRADIENT WEAKENS. NEARSHORE NOAA BUOYS 22 AND 27 SHOW NORTHERLY WINDS AROUND 20 KT WHILE NOAA BUOY 14 HAS LIGHT WINDS FROM THE SOUTH,WHERE THE SOUTHERLY STRATUS SURGE HAS PASSED. THE 0630Z ASCAT PASS SHOWED WINDS OF ABOUT 30 KT ACROSS ZONE 470 AND 20-25 KT ACROSS ZONE 475. SINCE WAVES ARE STARTING TO TREND DOWNWARD IT IS BELIEVED THAT THE WINDS HAVE EASED SUBSTANTIALLY OFFSHORE, SO LET BOTH THE GALE AND HAZARDOUS SEAS WARNINGS EXPIRE. DID EXTEND THE SCA FOR ZONE 450 FOR A FEW HOURS SINCE WINDS AND WAVES STAYED UP A LITTLE BIT LONGER THAN EXPECTED. THE TREND FOR TODAY INTO THURSDAY WILL BE EASING WINDS, WITH WINDS TURNING TO THE SOUTH ALONG THE NEARSHORE. EXPECT LIGHT TO MODERATE WINDS AND LOW SEAS THURSDAY AND FRIDAY. WINDS AND WAVES SHOULD INCREASE THIS WEEKEND AS THE PRESSURE GRADIENT STRENGTHENS. && .EKA WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY UNTIL 9 AM PDT THIS MORNING FOR PZZ450-475. SMALL CRAFT ADVISORY UNTIL 8 PM PDT THIS EVENING FOR PZZ470. && $$ VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA FOLLOW US ON FACEBOOK AND TWITTER AT: HTTP://WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.EUREKA.GOV HTTP://WWW.TWITTER.COM/NWSEUREKA
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1035 AM MDT WED APR 24 2013 .UPDATE... && .SHORT TERM...CURRENT FORECASTS LOOK ON TRACK. WATER VAPOR LOOPS CURRENTLY SHOWING WEAK ELONGATED DISTURBANCE MOVING ACROSS MOUNTAINS. SATELLITE INDICATING CLOUDS HAVE INCREASED OVER THE MOUNTAINS AND NORTHWEST FLOW ALOFT PROVIDING SOME OROGRAPHICS. AS A RESULT...AREAS OF LIGHT SNOW OCCURRING ALONG HIGHER MOUNTAINS. FROM WEB CAMS...THE LIGHT SNOW LOOKS TO BE CONFINED TO THE WEST AND NORTHWEST FACING SLOPES OF THE CONTINENTAL DIVIDE...MAINLY OVER SUMMIT AND GRAND COUNTIES. DISTURBANCE EXPECTED TO MOVE ACROSS PLAINS DURING THE AFTERNOON WITH LATEST RUC SHOWING THE MOISTURE OVER MOUNTAINS DECREASING. WILL MAINTAIN THE SLIGHT CHANCE OF SNOW. NO WEATHER OR POPS FOR PLAINS THOUGH SOME VIRGA POSSIBLE ACROSS FAR NORTHEAST CORNER DURING THE AFTERNOON AS DISTURBANCE MOVES OVER AREA. AFTERNOON HIGHS WILL BE TRICKY WITH VARYING AMOUNTS OF SNOW COVER. WILL MAINTAIN EXPECTED HIGHS AT THIS TIME...AND ADJUST AS NEEDED. .AVIATION...WINDS ACROSS AREA AIRPORTS STILL MAINTAINING A SOUTHWEST DIRECTION. LATEST MODELS SHOWING WINDS SHIFTING TO THE NORTHWEST IN THE 18-19Z TIME FRAME...WILL MAINTAIN CURRENT TAF TRENDS. WINDS SHOULD BECOME A BIT MORE NORTHEAST BY 01Z AS WEAK ANTICYCLONE TRIES TO DEVELOP ACROSS WELD COUNTY. SOUTHERLY DRAINAGE FLOW TO DEVELOP DURING THE EVENING. SOME INCREASE IN MID LEVEL CLOUD DURING THE AFTERNOON...CEILINGS SHOULD REMAIN ABOVE 12000 FEET. VFR TO CONTINUE. && .PREV DISCUSSION... /ISSUED 250 AM MDT WED APR 24 2013/ SHORT TERM...A WEAK DISTURBANCE IN NW FLOW ALOFT WILL PASS OVER THE AREA TODAY HOWEVER CROSS-SECTIONS SHOW LIMITED MOISTURE WITH THIS FEATURE. THUS WILL ONLY MENTION A SLIGHT CHC OF -SHSN IN THE MTNS WITH DRY CONDITIONS ESLEWHERE ALTHOUGH THERE COULD BE SOME VIRGA OVER THE FAR NERN PLAINS BY LATE AFTN. AS FOR TEMPS THE BEST SNOW COVER WAS OVER ERN ELBERT...LINCOLN...WASHINGTON AND ERN PART OF ADAMS AND ARAPAHOE COUNTIES. WILL KEEP HIGHS IN THESE AREAS IN THE 45 TO 50 DEGREE RANGE. OTHERWISE THERE WAS LIMITED SNOW COVER ELSEWHERE SO WILL HAVE HIGHS IN THE LOWER TO MID 50S OVER THE REST OF NERN CO. LONG TERM...ZONAL FLOW IS TO DOMINATE ACROSS THE FORECAST AREA THURSDAY INTO THURSDAY EVENING. A WEAK UPPER TROUGH IS PROGGED ACROSS COLORADO THURSDAY NIGHT INTO FRIDAY WITH WEAK NORTHERLY FLOW ALOFT FOR THE CWA FRIDAY NIGHT. THERE IS WEAK UPWARD QG VERTICAL MOTION THURSDAY AND THURSDAY EVENING...THEN THE SYNOPTIC SCALE ENERGY IS BENIGN ON FRIDAY AND FRIDAY NIGHT. THE BOUNDARY LAYER FLOW LOOKS TO ADHERE TO NORMAL DUIRNAL PATTERNS FOR THURSDAY...THEN A WEAK COLD FRONT AND WEAK UPSLOPE IS PROGGED THURSDAY NIGHT AND FRIDAY. BY FRIDAY NIGHT...NORMAL PATTERNS ARE BACK. THE MODELS HAVE INCREASING UPPER AND MID LEVEL MOISTURE ON THURSDAY INTO THURSDAY NIGHT. THERE NEVER REALLY IS ANY LOW LEVEL MOISTURE TO SPEAK OF. THINGS DRY OUT BY FRIDAY MORNING. THERE IS A TAD OF MEASURABLE PRECIPITATION ON THE QPF FIELDS THURSDAY AFTERNOON AND FRIDAY NIGHT...BUT ONLY OVER THE SOUTHERN CWA. THERE IS LIMITED CAPE OVER THE MOUNTAINS...FOOTHILLS...AND PALMER RIDGE LATE DAY THURSDAY. THERE IS EVEN LESS FOR LATE DAY FRIDAY. FOR POPS...WILL KEEP PRETTY MUCH WHAT THE GOING GFE GRIDS SHOW..."20%" OVER THE SOUTHERN CWA THURSDAY AFTERNOON AND EVENING. FOR TEMPERATURES...THURSDAY`S HIGHS ARE 5-6 C WARMER THAN TODAY`S. FRIDAY`S HIGHS ARE CLOSE TO THURSDAY`S WITH THE WEAK FRONT THAT IS PROGGED THURSDAY NIGHT. FOR THE LATER DAYS...SATURDAY THROUGH TUESDAY...THE NORTHWESTERLY FLOW ALOFT BECOMES ZONAL BY SATURDAY NIGHT. THIS INCREASES ON SUNDAY...THEN MODELS HAVE A WEAK BROAD UPPER TROUGH...MAINLY NORTH OF COLORADO...FOR MONDAY AFTERNOON AND NIGHT. PRETTY STRONG NORTHWESTERLY FLOW ALOFT IS PROGGED TUESDAY. MOISTURE IS FAIR ON GFS...AND POOR ON THE ECMWF. NO POPS RIGHT NOW. AVIATION...VFR THRU TONIGHT ALTHOUGH THERE COULD BE A BRIEF CLOUD DECK DOWN TO 10000 FT AS SOME MID LEVEL MOVES ACROSS LATER THIS MORNING INTO THE MID AFTN HOURS. DRAINAGE WINDS EARLY THIS MORNING MAY BECOME LIGHT NNE BY 15Z. BY EARLY AFTN THEY SHOULD BECOME MORE NNW WITH AVERAGE SPEEDS AROUND 10 KTS. BY EARLY EVENING WINDS SHOULD GRADUALLY BECOME SLY AND CONTINUE THAT WAY OVERNIGHT. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...D-L LONG TERM....RJK AVIATION...D-L
AREA FORECAST DISCUSSION
NWS ALBANY NY
344 PM EDT WED APR 24 2013 .SYNOPSIS... A COLD FRONT WILL SWEEP ACROSS THE REGION TONIGHT...WITH SHOWERS...ISOLATED THUNDER AND POSSIBLE GUSTY WINDS. COOLER AIR WILL FOLLOW AS HIGH PRESSURE WILL BUILD OVER THE EASTERN THIRD OF THE NATION THURSDAY...THEN DRIFT SLOWLY EAST INTO THE NEW WEEK. WEAK DISTURBANCES WILL PASS THROUGH THE REGION THURSDAY NIGHT AND SATURDAY NIGHT...POSSIBLY PRODUCING SOME PATCHY CLOUDS AND SCATTERED SHOWERS...BUT FOR THE MOST PART OUR WEATHER WILL BE FAIR AND SEASONABLE WITH MODERATING TEMPERATURES THROUGH THE WEEKEND. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... AS OF 145 PM EDT...MAIN CHANGE FOR THIS ESTF UPDATE WAS TO DELAY ONSET OF POPS BY SEVERAL HOURS ASSOCIATED WITH EXPECTED BANDS OF SHOWERS WITH SOME EMBEDDED THUNDER UNTIL THIS EVENING. MID LEVEL CLOUDS HAVE ACTUALLY BEEN ERODING EARLY THIS AFTERNOON AHEAD OF THE THICKER BATCH OF CLOUDS ASSOCIATED WITH THE SURFACE COLD FRONT AND UPPER LEVEL TROUGH MOVING EAST FROM THE GREAT LAKES AND OHIO VALLEY. LOCAL HIRES WRF AND HRRR IN GOOD AGREEMENT WITH DEPICTING BANDS OF SHOWERS MOVING IN DURING THE EVENING HOURS. THE WIND FIELD WILL STRENGTHEN FOR A BRIEF PERIOD OF TIME THIS EVENING COINCIDENT WITH THE ARRIVAL OF COLD FRONT...SO ADDED MENTION OF GUSTY WINDS TO ACCOMPANY BANDS OF SHOWERS AND SOME THUNDER. EXPANDED THE MENTION OF ISOLATED THUNDER TO ENCOMPASS THE ENTIRE AREA...AS LATEST GUIDANCE SHOWING ELEVATED INSTABILITY NORTH TO THE CANADIAN BORDER. SURFACE BASED CAPE WILL BE LACKING...SO SEVERE WEATHER NOT EXPECTED ALTHOUGH SOME STRONGER WIND GUSTS POSSIBLY UP TO 50 MPH MAY ACCOMPANY THE SHOWERS/STORMS. THE H850 TEMPS INCREASE +9 TO +13C AHEAD OF THE FRONT. THE H850 FLOW INCREASES FORM THE S/SW TO 40-55 KTS BY NIGHTFALL. IT WILL BECOME BREEZY IN THE PM WITH SOUTHERLY WINDS OF 10 TO 20 MPH WITH SOME GUSTS 30-35 MPH. MAX TEMPS IN THE U60S TO L70S WILL BE COMMON IN THE VALLEYS...AND 60S WILL BE LIKELY OVER THE MTNS WITH SFC DEWPTS RISING INTO THE 40S. TONIGHT...THE BEST CHC FOR WIDESPREAD RAINFALL FROM THE FRONT LOOKS TO BE IN THE 6 PM TO MIDNIGHT TIME FRAME. THERE IS DECENT LOW-LEVEL CONVERGENCE ALONG AND IN THE WAKE OF THE COLD FRONT. THE BETTER JET STREAK ALOFT RACES INTO QUEBEC...AS THE UNFAVORABLE RIGHT FRONT QUAD OF A 125+ KT H250 JET STREAK MOVES OVER THE SRN HALF OF THE FCST AREA...WHICH WILL DAMPEN THE PCPN A BIT SOUTH AND EAST OF THE CAPITAL REGION. THE THREAT FOR ISOLATED THUNDERSTORMS WAS KEPT IN UNTIL AROUND MIDNIGHT. POPS WERE INCREASED TO LIKELY AND CATEGORICAL VALUES. THE STEEPENING MID LEVEL LAPSE RATES...AND STRENGTHENING LOW LEVEL JET ASSOCIATED WITH THE FRONT WARRANTED PUTTING SOME WIND GUSTS TO 30 TO 40 MPH...ESPECIALLY JUST IN THE WAKE OF THE FRONT. THE PWATS DO EXCEED AN INCH FOR A BRIEF PERIOD OF TIME /COUPLE STANDARD DEVIATIONS ABOVE NORMAL/...BUT DROP OFF WITH THE BLAST OF COLD ADVECTION THAT FOLLOWS THE FRONTAL PASSAGE. QPF WILL RANGE FROM A TENTH OF AN INCH OR SO...OVER THE SOUTHEAST CORNER OF THE FCST AREA...TO UP TO A HALF AN INCH OVER THE NW EXTREME. SOME OF THE RESIDUAL POST FRONTAL SHOWERS OVER THE SRN DACKS MAY TRANSITION TO SNOW SHOWERS WITH LIGHT COATINGS TO A FEW TENTHS OF AN INCH IN A FEW SPOTS. MIN TEMPS ARE TRICKY TIMING THE COLD ADVECTION. THERE ARE LARGE DIFFERENCE BTWN THE NAM AND GFSMOS. THE GFS IS MUCH COLDER BY ALMOST 10 DEGREES IN SOME LOCATIONS. LEANED CLOSER TO THE WARMER NAM MOS GUIDANCE DUE TO ITS TRACK RECORD LATELY...AND ACTUALLY WENT CLOSE TO THE ECM MOS GUIDANCE. LOWS EXPECTED IN THE L40S IN THE HUDSON RIVER VALLEY...BERKS...CT RIVER VALLEY AND NW CT...MID AND U30S ELSEWHERE...EXCEPT SOME U20S TO L30S OVER THE SRN DACKS. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/... GOOD AGREEMENT AMONG MODEL SUITE (GFS/NAM/GEM/ECMWF) FOR THIS PERIOD WITH SOME DIFFERENCES THU NT ON THE MAGNITUDE OF SCT -SHRA/SHSN. THU MRNG CDFNT IS OFF NEW ENGLAND...SFC HIGH PRESSURE BUILDING INTO THE MID ATLC AND NYS. AT 500HPA GENERAL TROFINESS REMAINS OVER NE..AND ANOTHER 500HPA SHORT WV LINGERS OVER LK MICHIGAN. THU MORNING WILL BRING STRONG CAA...BUT SFC WIND GRADIENT WILL WEAKEN QUICKLY BY MIDDAY. OTHER THAN A FEW MORNING CLOUDS RESULT WILL BE A MOSTLY SUNNY MOST AREAS...PARTLY SUNNY HIR TRRN...COOL SEASONABLE MID APRIL DAY WITH HIGHS 50S TO LOW 60S. THU NT AND EARLY FRI A 500HPA SHORT WV MOVES ACROSS RGN THROUGH 500HPA TROF. THERE ONLY APPEARS TO BE A COLD POOL ASSOC WITH THIS SHORT WV...NO CDFNT...HENCE MOST OF ITS IMPACTS ARE CONVECTIVELY DIURNALLY DRIVEN...DIMINISHING OVERNIGHT. WHILE THE OTHER MODELS GO WITH THIS THINKING...THEY PRODUCE A TAD MORE QPF THAN THE DRY NAM WITH ITS PASSAGE THU NT. IN ANY SCENARIO THE AMOUNTS ARE A FEW HUNDREDTHS AT BEST. SO WILL CARRY CHC POPS MOST AREAS WITH POSSIBLE SLIGHT CHC FAR N AND SE. THIS TROF DEPARTS THE COAST BY MIDDAY FRI AND HIGH PRESSURE COVERS THE EASTERN HALF OF USA TO LABRADOR. SOME CLOUDS MAY LINGER TILL 500 HPA SHORT WV AND ITS COLD POOL MOVES E OF FCA...AND RESULT IN PARTLY SUNNY BUT SEASONABLE DAY. BY SAT AND SAT NT AXIS OF SFC HIGH IS ALONG THE ATLC SEABOARD...AND SOME DEGREE OF RETURN FLOW IS SETTING UP...ALBEIT WEAK. MORE SIG WAA IS OCCURRING IN THE MID LEVELS AND ANOTHER WEAK 500HPA TROF IS MOVING ACROSS RGN...WITH ENOUGH CLOUDS TO RESULT IN PARTLY SUNNY. HWVR TEMPS WILL REBOUND INTO THE 60S WITH SOME 50S OVER HIR TRRN. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... SUNDAY SFC HIGH SHIFTS JUST OFFSHORE...AND 500HPA RIDGE GRADUALLY BUILDS OVER EASTERN USA THROUGH WED. THIS LOCKS THE SFC HIGH ALONG THE SEABOARD...WITH GENTLE RETURN FLOW OVER FCA THROUGH EFP. PERIOD FEATURES SIG WAA AND TEMPS TURNING ABV NORMAL. MAX TEMPS REACH MID 60S TO MID 70S...LOWS MID 30S TO MID 40S. WHILE LARGELY A DRY MILD PERIOD..THERE ARE A FEW SUBTLE FEATURES THAT COULD INCR CLOUDS FROM TIME TO TIME AND TRIGGER SOME WIDELY SCT -SHRA. MAINLY SURGES IN WAA PARTICULARLY TO THE NW PTNS OF FCA. ATTM ALL GUID TAKES EVOLVING TROF AND SYSTEMS OVER GRT PLAINS WELL WEST AND SOUTH OF RGN. WHAT APPEARS TO TO A TRUE SPRING LIKE PERIOD IS EXPECTED...AND WILL POPULATE WITH HPC DROPPING SLIGHT CHC POOPS AS ALL SURROUNDING OFFICES DID GIVEN THE ECMWF MASSIVE 579 DM 500 RIDGE OVER FCA. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... VFR CONDITIONS ARE IN PLACE AT ALL TAF SITES WITH JUST SCT-BKN HIGH LEVEL CLOUDS ACROSS THE REGION. ALTHOUGH WINDS ARE CURRENTLY RATHER LIGHT...A SOUTHERLY BREEZE WILL INCREASE TO AROUND 10 KTS AT ALL SITES THROUGH THE AFTERNOON HOURS. AN APPROACHING COLD FRONT WILL BRING A BAND OF RAIN SHOWERS ACROSS THE REGION BETWEEN 02Z-07Z TONIGHT. THE RAIN SHOULD ONLY LAST AT ANY ONE PARTICULAR LOCATION FOR A FEW HOURS. THERE IS A SLIGHT CHC FOR SOME RUMBLES OF THUNDER...ALTHOUGH DUE TO THE UNCERTAINTY AND LOW PROBABILITY OF THIS OCCURRING...IT WILL NOT BE INCLUDED IN THE TAFS AT THIS TIME. WITHIN ANY RAIN SHOWERS...VSBYS AND PERHAPS CIGS AS WELL MAY LOWER TO MVFR RANGE. IFR CONDITIONS ARE NOT ANTICIPATED AT THIS TIME...ALTHOUGH A BRIEF DROP TO IFR CONDITIONS CANNOT BE TOTALLY RULED OUT...ESP IF ANY THUNDERSTORM DO DEVELOP. WITHIN AND JUST BEHIND THE RAIN SHOWERS...THE WINDS WILL SWITCH TO W-SW DIRECTION AND BECOME RATHER GUSTY. SOME GUSTS OF AROUND 25 KTS ARE POSSIBLE...ESP FOR KALB/KPSF. CLOUDS SHOULD START TO SCT OUT AFTER ABOUT 06Z-07Z...WITH VFR CONDITIONS RETURNING...AND SKIES WILL BE CLEAR BY MID THURSDAY MORNING. IN ADDITION...WINDS WILL DECREASE ON THURSDAY MORNING TO AROUND 5-10 KTS AFTER SUNRISE AS HIGH PRESSURE BUILDS INTO THE REGION...ALTHOUGH THERE STILL MAY BE A FEW LINGERING HIGHER WIND GUSTS AT KPSF/KALB THROUGH ABOUT NOON OR SO. OUTLOOK... THU-MON...VFR...NO SIG WX. && .FIRE WEATHER... A COLD FRONT WILL SWEEP ACROSS THE REGION TONIGHT...WITH SHOWERS...ISOLATED THUNDER AND POSSIBLE GUSTY WINDS. COOLER AIR WILL FOLLOW AS HIGH PRESSURE WILL BUILD OVER THE EASTERN THIRD OF THE NATION THURSDAY...THEN DRIFT SLOWLY EAST INTO THE NEW WEEK. WEAK DISTURBANCES WILL PASS THROUGH THE REGION THURSDAY NIGHT AND SATURDAY NIGHT...POSSIBLY PRODUCING SOME PATCHY CLOUDS AND SCATTERED SHOWERS...BUT FOR THE MOST PART CONDITIONS WILL BE FAIR...DRY AND SEASONABLE WITH MODERATING TEMPERATURES THROUGH THE WEEKEND. RH VALUES RISE TO 75 TO 100 PERCENT TONIGHT. THE RH VALUES WILL DROP TO 20-30 PERCENT BY THURSDAY AFTERNOON...RISING TO 60-75 PERCENT THURSDAY NIGHT...FALLING TO 20 TO 35 PERCENT FRIDAY AFTERNOON. THE WINDS WILL SHIFT TO THE SOUTHWEST OR WEST AT 10 TO 20 MPH TONIGHT WITH SOME GUSTS IN THE 30 TO 40 MPH RANGE WITH THE FRONTAL PASSAGE. THE WINDS WILL BE FROM THE NORTHWEST AT 10 TO 15 MPH WITH A FEW LOCATIONS HAVING GUSTS TO 25 MPH ON THURSDAY DIMINISHING TO AROUND 10 MPH DURING THE AFTERNOON. A WETTING RAINFALL WILL OCCUR TONIGHT WITH A QUARTER TO HALF AN INCH OF RAIN EXPECTED FROM THE CAPITAL REGION...BERKSHIRES AND EASTERN CATSKILLS NORTHWARD...WITH LESS THAN A QUARTER OF AN INCH POSSIBLE FURTHER SOUTH. && .HYDROLOGY... NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED OVER THE NEXT 5 DAYS. A WIDESPREAD RAINFALL IS EXPECTED TONIGHT. QPF SHOULD BE A QUARTER TO A HALF AN INCH OF RAINFALL WITH THIS EVENT. DRY WEATHER WILL RETURN THURSDAY AND DOMINATE INTO THE NEW WEEK WITH HIGH PRESSURE IN CONTROL. ISOLATED TO SCATTERED LIGHT RAIN OR SNOW SHOWERS ARE POSSIBLE THURSDAY NIGHT. RIVERS AND STREAMS WILL CONTINUE TO RECEDE WITH DRY WEATHER EXPECTED THE NEXT SEVERAL DAYS BEYOND THURSDAY NIGHT. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...SNYDER NEAR TERM...JPV SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...FRUGIS FIRE WEATHER...SNYDER/WASULA HYDROLOGY...FRUGIS/SNYDER/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
336 PM EDT WED APR 24 2013 .SYNOPSIS... A COLD FRONT WILL SWEEP ACROSS THE REGION TONIGHT...WITH SHOWERS...ISOLATED THUNDER AND POSSIBLE GUSTY WINDS. COOLER AIR WILL FOLLOW AS HIGH PRESSURE WILL BUILD OVER THE EASTERN THIRD OF THE NATION THURSDAY...THEN DRIFT SLOWLY EAST INTO THE NEW WEEK. WEAK DISTURBANCES WILL PASS THROUGH THE REGION THURSDAY NIGHT AND SATURDAY NIGHT...POSSIBLY PRODUCING SOME PATCHY CLOUDS AND SCATTERED SHOWERS...BUT FOR THE MOST PART OUR WEATHER WILL BE FAIR AND SEASONABLE WITH MODERATING TEMPERATURES THROUGH THE WEEKEND. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... AS OF 145 PM EDT...MAIN CHANGE FOR THIS ESTF UPDATE WAS TO DELAY ONSET OF POPS BY SEVERAL HOURS ASSOCIATED WITH EXPECTED BANDS OF SHOWERS WITH SOME EMBEDDED THUNDER UNTIL THIS EVENING. MID LEVEL CLOUDS HAVE ACTUALLY BEEN ERODING EARLY THIS AFTERNOON AHEAD OF THE THICKER BATCH OF CLOUDS ASSOCIATED WITH THE SURFACE COLD FRONT AND UPPER LEVEL TROUGH MOVING EAST FROM THE GREAT LAKES AND OHIO VALLEY. LOCAL HIRES WRF AND HRRR IN GOOD AGREEMENT WITH DEPICTING BANDS OF SHOWERS MOVING IN DURING THE EVENING HOURS. THE WIND FIELD WILL STRENGTHEN FOR A BRIEF PERIOD OF TIME THIS EVENING COINCIDENT WITH THE ARRIVAL OF COLD FRONT...SO ADDED MENTION OF GUSTY WINDS TO ACCOMPANY BANDS OF SHOWERS AND SOME THUNDER. EXPANDED THE MENTION OF ISOLATED THUNDER TO ENCOMPASS THE ENTIRE AREA...AS LATEST GUIDANCE SHOWING ELEVATED INSTABILITY NORTH TO THE CANADIAN BORDER. SURFACE BASED CAPE WILL BE LACKING...SO SEVERE WEATHER NOT EXPECTED ALTHOUGH SOME STRONGER WIND GUSTS POSSIBLY UP TO 50 MPH MAY ACCOMPANY THE SHOWERS/STORMS. THE H850 TEMPS INCREASE +9 TO +13C AHEAD OF THE FRONT. THE H850 FLOW INCREASES FORM THE S/SW TO 40-55 KTS BY NIGHTFALL. IT WILL BECOME BREEZY IN THE PM WITH SOUTHERLY WINDS OF 10 TO 20 MPH WITH SOME GUSTS 30-35 MPH. MAX TEMPS IN THE U60S TO L70S WILL BE COMMON IN THE VALLEYS...AND 60S WILL BE LIKELY OVER THE MTNS WITH SFC DEWPTS RISING INTO THE 40S. TONIGHT...THE BEST CHC FOR WIDESPREAD RAINFALL FROM THE FRONT LOOKS TO BE IN THE 6 PM TO MIDNIGHT TIME FRAME. THERE IS DECENT LOW-LEVEL CONVERGENCE ALONG AND IN THE WAKE OF THE COLD FRONT. THE BETTER JET STREAK ALOFT RACES INTO QUEBEC...AS THE UNFAVORABLE RIGHT FRONT QUAD OF A 125+ KT H250 JET STREAK MOVES OVER THE SRN HALF OF THE FCST AREA...WHICH WILL DAMPEN THE PCPN A BIT SOUTH AND EAST OF THE CAPITAL REGION. THE THREAT FOR ISOLATED THUNDERSTORMS WAS KEPT IN UNTIL AROUND MIDNIGHT. POPS WERE INCREASED TO LIKELY AND CATEGORICAL VALUES. THE STEEPENING MID LEVEL LAPSE RATES...AND STRENGTHENING LOW LEVEL JET ASSOCIATED WITH THE FRONT WARRANTED PUTTING SOME WIND GUSTS TO 30 TO 40 MPH...ESPECIALLY JUST IN THE WAKE OF THE FRONT. THE PWATS DO EXCEED AN INCH FOR A BRIEF PERIOD OF TIME /COUPLE STANDARD DEVIATIONS ABOVE NORMAL/...BUT DROP OFF WITH THE BLAST OF COLD ADVECTION THAT FOLLOWS THE FRONTAL PASSAGE. QPF WILL RANGE FROM A TENTH OF AN INCH OR SO...OVER THE SOUTHEAST CORNER OF THE FCST AREA...TO UP TO A HALF AN INCH OVER THE NW EXTREME. SOME OF THE RESIDUAL POST FRONTAL SHOWERS OVER THE SRN DACKS MAY TRANSITION TO SNOW SHOWERS WITH LIGHT COATINGS TO A FEW TENTHS OF AN INCH IN A FEW SPOTS. MIN TEMPS ARE TRICKY TIMING THE COLD ADVECTION. THERE ARE LARGE DIFFERENCE BTWN THE NAM AND GFSMOS. THE GFS IS MUCH COLDER BY ALMOST 10 DEGREES IN SOME LOCATIONS. LEANED CLOSER TO THE WARMER NAM MOS GUIDANCE DUE TO ITS TRACK RECORD LATELY...AND ACTUALLY WENT CLOSE TO THE ECM MOS GUIDANCE. LOWS EXPECTED IN THE L40S IN THE HUDSON RIVER VALLEY...BERKS...CT RIVER VALLEY AND NW CT...MID AND U30S ELSEWHERE...EXCEPT SOME U20S TO L30S OVER THE SRN DACKS. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/... GOOD AGREEMENT AMONG MODEL SUITE (GFS/NAM/GEM/ECMWF) FOR THIS PERIOD WITH SOME DIFFERENCES THU NT ON THE MAGNITUDE OF SCT -SHRA/SHSN. THU MRNG CDFNT IS OFF NEW ENGLAND...SFC HIGH PRESSURE BUILDING INTO THE MID ATLC AND NYS. AT 500HPA GENERAL TROFINESS REMAINS OVER NE..AND ANOTHER 500HPA SHORT WV LINGERS OVER LK MICHIGAN. THU MORNING WILL BRING STRONG CAA...BUT SFC WIND GRADIENT WILL WEAKEN QUICKLY BY MIDDAY. OTHER THAN A FEW MORNING CLOUDS RESULT WILL BE A MOSTLY SUNNY MOST AREAS...PARTLY SUNNY HIR TRRN...COOL SEASONABLE MID APRIL DAY WITH HIGHS 50S TO LOW 60S. THU NT AND EARLY FRI A 500HPA SHORT WV MOVES ACROSS RGN THROUGH 500HPA TROF. THERE ONLY APPEARS TO BE A COLD POOL ASSOC WITH THIS SHORT WV...NO CDFNT...HENCE MOST OF ITS IMPACTS ARE CONVECTIVELY DIURNALLY DRIVEN...DIMINISHING OVERNIGHT. WHILE THE OTHER MODELS GO WITH THIS THINKING...THEY PRODUCE A TAD MORE QPF THAN THE DRY NAM WITH ITS PASSAGE THU NT. IN ANY SCENARIO THE AMOUNTS ARE A FEW HUNDREDTHS AT BEST. SO WILL CARRY CHC POPS MOST AREAS WITH POSSIBLE SLIGHT CHC FAR N AND SE. THIS TROF DEPARTS THE COAST BY MIDDAY FRI AND HIGH PRESSURE COVERS THE EASTERN HALF OF USA TO LABRADOR. SOME CLOUDS MAY LINGER TILL 500 HPA SHORT WV AND ITS COLD POOL MOVES E OF FCA...AND RESULT IN PARTLY SUNNY BUT SEASONABLE DAY. BY SAT AND SAT NT AXIS OF SFC HIGH IS ALONG THE ATLC SEABOARD...AND SOME DEGREE OF RETURN FLOW IS SETTING UP...ALBEIT WEAK. MORE SIG WAA IS OCCURRING IN THE MID LEVELS AND ANOTHER WEAK 500HPA TROF IS MOVING ACROSS RGN...WITH ENOUGH CLOUDS TO RESULT IN PARTLY SUNNY. HWVR TEMPS WILL REBOUND INTO THE 60S WITH SOME 50S OVER HIR TRRN. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... SUNDAY SFC HIGH SHIFTS JUST OFFSHORE...AND 500HPA RIDGE GRADUALLY BUILDS OVER EASTERN USA THROUGH WED. THIS LOCKS THE SFC HIGH ALONG THE SEABOARD...WITH GENTLE RETURN FLOW OVER FCA THROUGH EFP. PERIOD FEATURES SIG WAA AND TEMPS TURNING ABV NORMAL. MAX TEMPS REACH MID 60S TO MID 70S...LOWS MID 30S TO MID 40S. WHILE LARGELY A DRY MILD PERIOD..THERE ARE A FEW SUBTLE FEATURES THAT COULD INCR CLOUDS FROM TIME TO TIME AND TRIGGER SOME WIDELY SCT -SHRA. MAINLY SURGES IN WAA PARTICULARLY TO THE NW PTNS OF FCA. ATTM ALL GUID TAKES EVOLVING TROF AND SYSTEMS OVER GRT PLAINS WELL WEST AND SOUTH OF RGN. WHAT APPEARS TO TO A TRUE SPRING LIKE PERIOD IS EXPECTED...AND WILL POPULATE WITH HPC. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... VFR CONDITIONS ARE IN PLACE AT ALL TAF SITES WITH JUST SCT-BKN HIGH LEVEL CLOUDS ACROSS THE REGION. ALTHOUGH WINDS ARE CURRENTLY RATHER LIGHT...A SOUTHERLY BREEZE WILL INCREASE TO AROUND 10 KTS AT ALL SITES THROUGH THE AFTERNOON HOURS. AN APPROACHING COLD FRONT WILL BRING A BAND OF RAIN SHOWERS ACROSS THE REGION BETWEEN 02Z-07Z TONIGHT. THE RAIN SHOULD ONLY LAST AT ANY ONE PARTICULAR LOCATION FOR A FEW HOURS. THERE IS A SLIGHT CHC FOR SOME RUMBLES OF THUNDER...ALTHOUGH DUE TO THE UNCERTAINTY AND LOW PROBABILITY OF THIS OCCURRING...IT WILL NOT BE INCLUDED IN THE TAFS AT THIS TIME. WITHIN ANY RAIN SHOWERS...VSBYS AND PERHAPS CIGS AS WELL MAY LOWER TO MVFR RANGE. IFR CONDITIONS ARE NOT ANTICIPATED AT THIS TIME...ALTHOUGH A BRIEF DROP TO IFR CONDITIONS CANNOT BE TOTALLY RULED OUT...ESP IF ANY THUNDERSTORM DO DEVELOP. WITHIN AND JUST BEHIND THE RAIN SHOWERS...THE WINDS WILL SWITCH TO W-SW DIRECTION AND BECOME RATHER GUSTY. SOME GUSTS OF AROUND 25 KTS ARE POSSIBLE...ESP FOR KALB/KPSF. CLOUDS SHOULD START TO SCT OUT AFTER ABOUT 06Z-07Z...WITH VFR CONDITIONS RETURNING...AND SKIES WILL BE CLEAR BY MID THURSDAY MORNING. IN ADDITION...WINDS WILL DECREASE ON THURSDAY MORNING TO AROUND 5-10 KTS AFTER SUNRISE AS HIGH PRESSURE BUILDS INTO THE REGION...ALTHOUGH THERE STILL MAY BE A FEW LINGERING HIGHER WIND GUSTS AT KPSF/KALB THROUGH ABOUT NOON OR SO. OUTLOOK... THU-MON...VFR...NO SIG WX. && .FIRE WEATHER... A COLD FRONT WILL SWEEP ACROSS THE REGION TONIGHT...WITH SHOWERS...ISOLATED THUNDER AND POSSIBLE GUSTY WINDS. COOLER AIR WILL FOLLOW AS HIGH PRESSURE WILL BUILD OVER THE EASTERN THIRD OF THE NATION THURSDAY...THEN DRIFT SLOWLY EAST INTO THE NEW WEEK. WEAK DISTURBANCES WILL PASS THROUGH THE REGION THURSDAY NIGHT AND SATURDAY NIGHT...POSSIBLY PRODUCING SOME PATCHY CLOUDS AND SCATTERED SHOWERS...BUT FOR THE MOST PART CONDITIONS WILL BE FAIR...DRY AND SEASONABLE WITH MODERATING TEMPERATURES THROUGH THE WEEKEND. RH VALUES RISE TO 75 TO 100 PERCENT TONIGHT. THE RH VALUES WILL DROP TO 20-30 PERCENT BY THURSDAY AFTERNOON...RISING TO 60-75 PERCENT THURSDAY NIGHT...FALLING TO 20 TO 35 PERCENT FRIDAY AFTERNOON. THE WINDS WILL SHIFT TO THE SOUTHWEST OR WEST AT 10 TO 20 MPH TONIGHT WITH SOME GUSTS IN THE 30 TO 40 MPH RANGE WITH THE FRONTAL PASSAGE. THE WINDS WILL BE FROM THE NORTHWEST AT 10 TO 15 MPH WITH A FEW LOCATIONS HAVING GUSTS TO 25 MPH ON THURSDAY DIMINISHING TO AROUND 10 MPH DURING THE AFTERNOON. A WETTING RAINFALL WILL OCCUR TONIGHT WITH A QUARTER TO HALF AN INCH OF RAIN EXPECTED FROM THE CAPITAL REGION...BERKSHIRES AND EASTERN CATSKILLS NORTHWARD...WITH LESS THAN A QUARTER OF AN INCH POSSIBLE FURTHER SOUTH. && .HYDROLOGY... NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED OVER THE NEXT 5 DAYS. A WIDESPREAD RAINFALL IS EXPECTED TONIGHT. QPF SHOULD BE A QUARTER TO A HALF AN INCH OF RAINFALL WITH THIS EVENT. DRY WEATHER WILL RETURN THURSDAY AND DOMINATE INTO THE NEW WEEK WITH HIGH PRESSURE IN CONTROL. ISOLATED TO SCATTERED LIGHT RAIN OR SNOW SHOWERS ARE POSSIBLE THURSDAY NIGHT. RIVERS AND STREAMS WILL CONTINUE TO RECEDE WITH DRY WEATHER EXPECTED THE NEXT SEVERAL DAYS BEYOND THURSDAY NIGHT. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...SNYDER NEAR TERM...JPV SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...FRUGIS FIRE WEATHER...WASULA/SNYDER HYDROLOGY...FRUGIS/WASULA/SNYDER
AREA FORECAST DISCUSSION
NWS ALBANY NY
243 PM EDT WED APR 24 2013 .SYNOPSIS... A COLD FRONT WILL SWEEP ACROSS THE REGION TONIGHT...WITH SHOWERS...ISOLATED THUNDER AND POSSIBLE GUSTY WINDS. COOLER AIR WILL FOLLOW AS HIGH PRESSURE WILL BUILD OVER THE EASTERN THIRD OF THE NATION THURSDAY...THEN DRIFT SLOWLY EAST INTO THE NEW WEEK. WEAK DISTURBANCES WILL PASS THROUGH THE REGION THURSDAY NIGHT AND SATURDAY NIGHT...POSSIBLY PRODUCING SOME PATCHY CLOUDS AND SCATTERED SHOWERS...BUT FOR THE MOST PART OUR WEATHER WILL BE FAIR AND SEASONABLE WITH MODERATING TEMPERATURES THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 145 PM EDT...MAIN CHANGE FOR THIS ESTF UPDATE WAS TO DELAY ONSET OF POPS BY SEVERAL HOURS ASSOCIATED WITH EXPECTED BANDS OF SHOWERS WITH SOME EMBEDDED THUNDER UNTIL THIS EVENING. MID LEVEL CLOUDS HAVE ACTUALLY BEEN ERODING EARLY THIS AFTERNOON AHEAD OF THE THICKER BATCH OF CLOUDS ASSOCIATED WITH THE SURFACE COLD FRONT AND UPPER LEVEL TROUGH MOVING EAST FROM THE GREAT LAKES AND OHIO VALLEY. LOCAL HIRES WRF AND HRRR IN GOOD AGREEMENT WITH DEPICTING BANDS OF SHOWERS MOVING IN DURING THE EVENING HOURS. THE WIND FIELD WILL STRENGTHEN FOR A BRIEF PERIOD OF TIME THIS EVENING COINCIDENT WITH THE ARRIVAL OF COLD FRONT...SO ADDED MENTION OF GUSTY WINDS TO ACCOMPANY BANDS OF SHOWERS AND SOME THUNDER. EXPANDED THE MENTION OF ISOLATED THUNDER TO ENCOMPASS THE ENTIRE AREA...AS LATEST GUIDANCE SHOWING ELEVATED INSTABILITY NORTH TO THE CANADIAN BORDER. SURFACE BASED CAPE WILL BE LACKING...SO SEVERE WEATHER NOT EXPECTED ALTHOUGH SOME STRONGER WIND GUSTS POSSIBLY UP TO 50 MPH MAY ACCOMPANY THE SHOWERS/STORMS. THE H850 TEMPS INCREASE +9 TO +13C AHEAD OF THE FRONT. THE H850 FLOW INCREASES FORM THE S/SW TO 40-55 KTS BY NIGHTFALL. IT WILL BECOME BREEZY IN THE PM WITH SOUTHERLY WINDS OF 10 TO 20 MPH WITH SOME GUSTS 30-35 MPH. MAX TEMPS IN THE U60S TO L70S WILL BE COMMON IN THE VALLEYS...AND 60S WILL BE LIKELY OVER THE MTNS WITH SFC DEWPTS RISING INTO THE 40S. TONIGHT...THE BEST CHC FOR WIDESPREAD RAINFALL FROM THE FRONT LOOKS TO BE IN THE 6 PM TO MIDNIGHT TIME FRAME. THERE IS DECENT LOW-LEVEL CONVERGENCE ALONG AND IN THE WAKE OF THE COLD FRONT. THE BETTER JET STREAK ALOFT RACES INTO QUEBEC...AS THE UNFAVORABLE RIGHT FRONT QUAD OF A 125+ KT H250 JET STREAK MOVES OVER THE SRN HALF OF THE FCST AREA...WHICH WILL DAMPEN THE PCPN A BIT SOUTH AND EAST OF THE CAPITAL REGION. THE THREAT FOR ISOLATED THUNDERSTORMS WAS KEPT IN UNTIL AROUND MIDNIGHT. POPS WERE INCREASED TO LIKELY AND CATEGORICAL VALUES. THE STEEPENING MID LEVEL LAPSE RATES...AND STRENGTHENING LOW LEVEL JET ASSOCIATED WITH THE FRONT WARRANTED PUTTING SOME WIND GUSTS TO 30 TO 40 MPH...ESPECIALLY JUST IN THE WAKE OF THE FRONT. THE PWATS DO EXCEED AN INCH FOR A BRIEF PERIOD OF TIME /COUPLE STANDARD DEVIATIONS ABOVE NORMAL/...BUT DROP OFF WITH THE BLAST OF COLD ADVECTION THAT FOLLOWS THE FRONTAL PASSAGE. QPF WILL RANGE FROM A TENTH OF AN INCH OR SO...OVER THE SOUTHEAST CORNER OF THE FCST AREA...TO UP TO A HALF AN INCH OVER THE NW EXTREME. SOME OF THE RESIDUAL POST FRONTAL SHOWERS OVER THE SRN DACKS MAY TRANSITION TO SNOW SHOWERS WITH LIGHT COATINGS TO A FEW TENTHS OF AN INCH IN A FEW SPOTS. MIN TEMPS ARE TRICKY TIMING THE COLD ADVECTION. THERE ARE LARGE DIFFERENCE BTWN THE NAM AND GFSMOS. THE GFS IS MUCH COLDER BY ALMOST 10 DEGREES IN SOME LOCATIONS. LEANED CLOSER TO THE WARMER NAM MOS GUIDANCE DUE TO ITS TRACK RECORD LATELY...AND ACTUALLY WENT CLOSE TO THE ECM MOS GUIDANCE. LOWS EXPECTED IN THE L40S IN THE HUDSON RIVER VALLEY...BERKS...CT RIVER VALLEY AND NW CT...MID AND U30S ELSEWHERE...EXCEPT SOME U20S TO L30S OVER THE SRN DACKS. && .SHORT TERM /THURSDAY THROUGH SUNDAY/... GOOD AGREEMENT AMONG MODEL SUITE (GFS/NAM/GEM/ECMWF) FOR THIS PERIOD WITH SOME DIFFERENCES THU NT ON THE MAGNITUDE OF SCT -SHRA/SHSN. THU MRNG CDFNT IS OFF NEW ENGLAND...SFC HIGH PRESSURE BUILDING INTO THE MID ATLC AND NYS. AT 500HPA GENERAL TROFINESS REMAINS OVER NE..AND ANOTHER 500HPA SHORT WV LINGERS OVER LK MICHIGAN. THU MORNING WILL BRING STRONG CAA...BUT SFC WIND GRADIENT WILL WEAKEN QUICKLY BY MIDDAY. OTHER THAN A FEW MORNING CLOUDS RESULT WILL BE A MOSTLY SUNNY MOST AREAS...PARTLY SUNNY HIR TRRN...COOL SEASONABLE MID APRIL DAY WITH HIGHS 50S TO LOW 60S. THU NT AND EARLY FRI A 500HPA SHORT WV MOVES ACROSS RGN THROUGH 500HPA TROF. THERE ONLY APPEARS TO BE A COLD POOL ASSOC WITH THIS SHORT WV...NO CDFNT...HENCE MOST OF ITS IMPACTS ARE CONVECTIVELY DIURNALLY DRIVEN...DIMINISHING OVERNIGHT. WHILE THE OTHER MODELS GO WITH THIS THINKING...THEY PRODUCE A TAD MORE QPF THAN THE DRY NAM WITH ITS PASSAGE THU NT. IN ANY SCENARIO THE AMOUNTS ARE A FEW HUNDREDTHS AT BEST. SO WILL CARRY CHC POPS MOST AREAS WITH POSSIBLE SLIGHT CHC FAR N AND SE. THIS TROF DEPARTS THE COAST BY MIDDAY FRI AND HIGH PRESSURE COVERS THE EASTERN HALF OF USA TO LABRADOR. SOME CLOUDS MAY LINGER TILL 500 HPA SHORT WV AND ITS COLD POOL MOVES E OF FCA...AND RESULT IN PARTLY SUNNY BUT SEASONABLE DAY. BY SAT AXIS OF SFC HIGH IS ALONG THE ATLC SEABOARD...AND SOME DEGREE OF RETURN FLOW IS SETTING UP...ALBIET WEAK. MORE SIG WAA IS OCCURRING IN THE MID LEVELS AND ANOTHER WEAK 500HPA TROF IS MOVING ACROSS RGN...WITH ENOUGH CLOUDS TO RESULT IN PARTLY SUNNY. HWVR TEMPS WILL REBOUND INTO THE 60S WITH SOME 50S OVER HIR TRRN. SAT NT AND SUN SFC HIGH SHIFTS OFFSHORE...AND WEAK 500HPA RIDGE BUILDS INTO NY AND NEW ENG. WAA ACCELERATES IN RETURN FLOW...BUT AGAIN IT REMAINS WEAK. TEMPS MODERATE A NOTCH OR TWO MORE AS HIGHS REACH MID 60S TO LOW 70S. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... RATHER UNUSUAL TO BE FORECASTING AN ENTIRELY DRY LONG TERM PERIOD...HOWEVER THAT IS THE CASE WITH THIS LONG TERM FORECAST. HIGH PRESSURE WILL DOMINATE OUR WEATHER INITIALLY BUILDING AT THE SURFACE AND THEN ALOFT AS WELL BY MONDAY AND TUESDAY. THE STRENGTHENING HIGH PRESSURE SYSTEM WILL KEEP ANY MOISTURE WHICH TRIES TO LIFT NORTHWARD WELL SOUTH OF OUR REGION. OVERALL EXPECT TEMPS IN THE LONG TERM PERIOD TO AVERAGE SLIGHTLY ABOVE NORMAL WITH PRECIPITATION BELOW NORMAL. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... VFR CONDITIONS ARE IN PLACE AT ALL TAF SITES WITH JUST SCT-BKN HIGH LEVEL CLOUDS ACROSS THE REGION. ALTHOUGH WINDS ARE CURRENTLY RATHER LIGHT...A SOUTHERLY BREEZE WILL INCREASE TO AROUND 10 KTS AT ALL SITES THROUGH THE AFTERNOON HOURS. AN APPROACHING COLD FRONT WILL BRING A BAND OF RAIN SHOWERS ACROSS THE REGION BETWEEN 02Z-07Z TONIGHT. THE RAIN SHOULD ONLY LAST AT ANY ONE PARTICULAR LOCATION FOR A FEW HOURS. THERE IS A SLIGHT CHC FOR SOME RUMBLES OF THUNDER...ALTHOUGH DUE TO THE UNCERTAINTY AND LOW PROBABILITY OF THIS OCCURRING...IT WILL NOT BE INCLUDED IN THE TAFS AT THIS TIME. WITHIN ANY RAIN SHOWERS...VSBYS AND PERHAPS CIGS AS WELL MAY LOWER TO MVFR RANGE. IFR CONDITIONS ARE NOT ANTICIPATED AT THIS TIME...ALTHOUGH A BRIEF DROP TO IFR CONDITIONS CANNOT BE TOTALLY RULED OUT...ESP IF ANY THUNDERSTORM DO DEVELOP. WITHIN AND JUST BEHIND THE RAIN SHOWERS...THE WINDS WILL SWITCH TO W-SW DIRECTION AND BECOME RATHER GUSTY. SOME GUSTS OF AROUND 25 KTS ARE POSSIBLE...ESP FOR KALB/KPSF. CLOUDS SHOULD START TO SCT OUT AFTER ABOUT 06Z-07Z...WITH VFR CONDITIONS RETURNING...AND SKIES WILL BE CLEAR BY MID THURSDAY MORNING. IN ADDITION...WINDS WILL DECREASE ON THURSDAY MORNING TO AROUND 5-10 KTS AFTER SUNRISE AS HIGH PRESSURE BUILDS INTO THE REGION...ALTHOUGH THERE STILL MAY BE A FEW LINGERING HIGHER WIND GUSTS AT KPSF/KALB THROUGH ABOUT NOON OR SO. OUTLOOK... THU-MON...VFR...NO SIG WX. && .FIRE WEATHER... A COLD FRONT WILL BRING SHOWERS AND ISOLATED THUNDERSTORMS TO EASTERN NEW YORK AND WESTERN NEW ENGLAND LATE THIS AFTERNOON INTO THE OVERNIGHT PERIOD. HIGH PRESSURE WILL BRIEFLY BUILD IN ON THURSDAY WITH AN UPPER LEVEL DISTURBANCE PRODUCING SOME ISOLATED TO SCATTERED RAIN AND SNOW SHOWERS. RH VALUES WILL LOWER TO 30 TO 40 PERCENT LATE THIS AFTERNOON...AND THEN RISE TO 75 TO 100 PERCENT TONIGHT. THE RH VALUES WILL DROP TO 20-30 PERCENT BY THURSDAY AFTERNOON. THE WINDS WILL INCREASE FROM THE SOUTH AT 10 TO 20 MPH WITH SOME GUSTS TO 30 MPH TODAY. THE WINDS WILL SHIFT TO THE SOUTHWEST OR WEST AT 10 TO 20 MPH TONIGHT WITH SOME GUSTS IN THE 30 TO 40 MPH RANGE WITH THE FRONTAL PASSAGE. THE WINDS WILL BE FROM THE NORTHWEST AT 10 TO 15 MPH WITH A FEW LOCATIONS HAVING GUSTS TO 25 MPH ON THURSDAY. A WETTING RAINFALL WILL OCCUR LATE THIS AFTERNOON INTO TONIGHT WITH A QUARTER TO HALF AN INCH OF RAIN EXPECTED FROM THE CAPITAL REGION...BERKSHIRES AND EASTERN CATSKILLS NORTHWARD...WITH LESS THAN A QUARTER OF AN INCH POSSIBLE FURTHER SOUTH. && .HYDROLOGY... NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED OVER THE NEXT 5 DAYS. THE NEXT WIDESPREAD RAINFALL IS EXPECTED LATE THIS AFTERNOON INTO TONIGHT. THE HPC QPF HAS LOWERED A BIT WITH GENERALLY A QUARTER TO A HALF AN INCH OF RAINFALL FROM THE CAPITAL REGION...BERKSHIRES...AND THE EASTERN CATSKILLS NORTHWARD...WITH LESS THAN A QUARTER INCH FOR MOST LOCATIONS TO THE SOUTH. SNOWMELT WILL CONTINUE ACROSS THE ADIRONDACKS AND SOUTHERN GREENS ON WEDNESDAY...DUE TO MAX TEMPS REACHING INTO THE 60S AND DEWPOINTS GETTING INTO THE 40S. DESPITE THE SNOWMELT...WHICH IS MUCH MORE LIMITED DUE TO THE SMALLER AREAL COVERAGE...THE EXPECTED RAINFALL LOOKS LIGHT ENOUGH TO AVOID ANY ISOLATED HYDROLOGIC ISSUES IN THOSE AREAS. DRY WEATHER WILL RETURN FOR THURSDAY WITH HIGH PRESSURE IN CONTROL. ISOLATED TO SCATTERED LIGHT RAIN OR SNOW SHOWERS MAY RETURN FOR THURSDAY NIGHT FOR LOCATIONS NORTH OF THE MID HUDSON VALLEY AND NW CT. RIVERS AND STREAMS WILL CONTINUE TO RECEDE WITH DRY WEATHER EXPECTED THE NEXT SEVERAL DAYS BEYOND THURSDAY NIGHT. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...SNYDER NEAR TERM...JPV SHORT TERM...SNYDER LONG TERM...11 AVIATION...FRUGIS FIRE WEATHER...WASULA HYDROLOGY...FRUGIS/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
144 PM EDT WED APR 24 2013 .SYNOPSIS... A MILDER AIR MASS WILL YIELD ABOVE NORMAL TEMPERATURES THIS AFTERNOON BEFORE A COLD FRONT ARRIVES WITH SHOWERS...AND PERHAPS A FEW THUNDERSTORMS...IN THE EVENING. HIGH PRESSURE WILL BRIEFLY BUILD INTO THE REGION WITH SEASONABLE TEMPERATURES FOR THURSDAY. A STRONG UPPER LEVEL DISTURBANCE MAY BRING ISOLATED TO SCATTERED RAIN AND SNOW SHOWERS TO PARTS OF EASTERN NEW YORK AND WESTERN NEW ENGLAND THURSDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 145 PM EDT...MAIN CHANGE FOR THIS ESTF UPDATE WAS TO DELAY ONSET OF POPS BY SEVERAL HOURS ASSOCIATED WITH EXPECTED BANDS OF SHOWERS WITH SOME EMBEDDED THUNDER UNTIL THIS EVENING. MID LEVEL CLOUDS HAVE ACTUALLY BEEN ERODING EARLY THIS AFTERNOON AHEAD OF THE THICKER BATCH OF CLOUDS ASSOCIATED WITH THE SURFACE COLD FRONT AND UPPER LEVEL TROUGH MOVING EAST FROM THE GREAT LAKES AND OHIO VALLEY. LOCAL HIRES WRF AND HRRR IN GOOD AGREEMENT WITH DEPICTING BANDS OF SHOWERS MOVING IN DURING THE EVENING HOURS. THE WIND FIELD WILL STRENGTHEN FOR A BRIEF PERIOD OF TIME THIS EVENING COINCIDENT WITH THE ARRIVAL OF COLD FRONT...SO ADDED MENTION OF GUSTY WINDS TO ACCOMPANY BANDS OF SHOWERS AND SOME THUNDER. EXPANDED THE MENTION OF ISOLATED THUNDER TO ENCOMPASS THE ENTIRE AREA...AS LATEST GUIDANCE SHOWING ELEVATED INSTABILITY NORTH TO THE CANADIAN BORDER. SURFACE BASED CAPE WILL BE LACKING...SO SEVERE WEATHER NOT EXPECTED ALTHOUGH SOME STRONGER WIND GUSTS POSSIBLY UP TO 50 MPH MAY ACCOMPANY THE SHOWERS/STORMS. THE H850 TEMPS INCREASE +9 TO +13C AHEAD OF THE FRONT. THE H850 FLOW INCREASES FORM THE S/SW TO 40-55 KTS BY NIGHTFALL. IT WILL BECOME BREEZY IN THE PM WITH SOUTHERLY WINDS OF 10 TO 20 MPH WITH SOME GUSTS 30-35 MPH. MAX TEMPS IN THE U60S TO L70S WILL BE COMMON IN THE VALLEYS...AND 60S WILL BE LIKELY OVER THE MTNS WITH SFC DEWPTS RISING INTO THE 40S. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... TONIGHT...THE BEST CHC FOR WIDESPREAD RAINFALL FROM THE FRONT LOOKS TO BE IN THE 6 PM TO MIDNIGHT TIME FRAME. THERE IS DECENT LOW-LEVEL CONVERGENCE ALONG AND IN THE WAKE OF THE COLD FRONT. THE BETTER JET STREAK ALOFT RACES INTO QUEBEC...AS THE UNFAVORABLE RIGHT FRONT QUAD OF A 125+ KT H250 JET STREAK MOVES OVER THE SRN HALF OF THE FCST AREA...WHICH WILL DAMPEN THE PCPN A BIT SOUTH AND EAST OF THE CAPITAL REGION. THE THREAT FOR ISOLATED THUNDERSTORMS WAS KEPT IN UNTIL AROUND MIDNIGHT. POPS WERE INCREASED TO LIKELY AND CATEGORICAL VALUES. THE STEEPENING MID LEVEL LAPSE RATES...AND STRENGTHENING LOW LEVEL JET ASSOCIATED WITH THE FRONT WARRANTED PUTTING SOME WIND GUSTS TO 30 TO 40 MPH...ESPECIALLY JUST IN THE WAKE OF THE FRONT. THE PWATS DO EXCEED AN INCH FOR A BRIEF PERIOD OF TIME /COUPLE STANDARD DEVIATIONS ABOVE NORMAL/...BUT DROP OFF WITH THE BLAST OF COLD ADVECTION THAT FOLLOWS THE FRONTAL PASSAGE. QPF WILL RANGE FROM A TENTH OF AN INCH OR SO...OVER THE SOUTHEAST CORNER OF THE FCST AREA...TO UP TO A HALF AN INCH OVER THE NW EXTREME. SOME OF THE RESIDUAL POST FRONTAL SHOWERS OVER THE SRN DACKS MAY TRANSITION TO SNOW SHOWERS WITH LIGHT COATINGS TO A FEW TENTHS OF AN INCH IN A FEW SPOTS. MIN TEMPS ARE TRICKY TIMING THE COLD ADVECTION. THERE ARE LARGE DIFFERENCE BTWN THE NAM AND GFSMOS. THE GFS IS MUCH COLDER BY ALMOST 10 DEGREES IN SOME LOCATIONS. LEANED CLOSER TO THE WARMER NAM MOS GUIDANCE DUE TO ITS TRACK RECORD LATELY...AND ACTUALLY WENT CLOSE TO THE ECM MOS GUIDANCE. LOWS EXPECTED IN THE L40S IN THE HUDSON RIVER VALLEY...BERKS...CT RIVER VALLEY AND NW CT...MID AND U30S ELSEWHERE...EXCEPT SOME U20S TO L30S OVER THE SRN DACKS. THURSDAY...HIGH PRESSURE QUICKLY RIDGES IN FROM THE SOUTH AND WEST WITH A BRIEF PERIOD OF DRY WEATHER...AS A POTENT SHORT-WAVE TROUGH QUICKLY MOVES TOWARDS THE REGION FROM THE GREAT LAKES REGION. THIS DAY WILL BE SEASONABLY WARM AND DRY WITH H850 TEMPS IN THE 0C TO -4C RANGE OVER THE REGION. EXPECT U50S TO L60S IN THE VALLEYS...AND U40S TO M50S OVER THE HIGHER TERRAIN. THURSDAY NIGHT...TRICKY DYNAMIC SHORT-WAVE LACKING ROBUST LOW- LEVEL MOISTURE TO WORK WITH. THE NAM HAS THE TROUGH PASS THROUGH FAIRLY DRY. THE GFS/ECMWF CONTINUE TO PAINT LIGHT AMOUNTS OF QPF OF A FEW HUNDREDTHS TO A TENTH OF AN INCH FROM THE ERN CATSKILLS...CAPITAL REGION...NRN BERKS NORTHWARD. THE DIFFERENTIAL CYCLONIC VORTICITY WILL TRIGGER SOME ISOLD-SCT RAIN AND SNOW SHOWERS. THERE WILL LIKELY BE A QUICK SHOT OF RADIATIONAL COOLING AHEAD OF THIS POTENT SHORT-WAVE WITH TEMPS FALLING INTO THE M20S TO M30S ACROSS THE REGION. COATING TO HALF INCH SNOW AMOUNTS WILL BE POSSIBLE ESPECIALLY FOR ELEVATIONS 500 FT AND GREATER...A LITTLE WET SNOW MIGHT ALSO OCCUR AT THE VALLEY FLOOR LOCATIONS. FRIDAY...LOW AND MID LEVEL HEIGHTS QUICKLY RISE AS THE SHORT-WAVE TROUGH ZIPS BY NRN NEW ENGLAND BY THE PM. SFC HIGH PRESSURE BUILDS IN FROM THE OHIO VALLEY...AND THE GREAT LAKES REGION WITH FAIR AND DRY WX FOR THE AFTERNOON. EXPECT HIGHS IN THE L60S IN THE CAPITAL REGION...MID HUDSON VALLEY...CNTRL AND SRN TACONICS...AND NW CT. MID AND U50S WILL PREVAIL IN ALL OTHER LOCATIONS. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... RATHER UNUSUAL TO BE FORECASTING AN ENTIRELY DRY LONG TERM PERIOD...HOWEVER THAT IS THE CASE WITH THIS LONG TERM FORECAST. HIGH PRESSURE WILL DOMINATE OUR WEATHER INITIALLY BUILDING AT THE SURFACE AND THEN ALOFT AS WELL BY MONDAY AND TUESDAY. THE STRENGTHENING HIGH PRESSURE SYSTEM WILL KEEP ANY MOISTURE WHICH TRIES TO LIFT NORTHWARD WELL SOUTH OF OUR REGION. EXPECT HIGHS ON SATURDAY TO BE IN THE UPPER 50S TO MID 60S WITH HIGHS SUNDAY THROUGH TUESDAY MAINLY IN THE 60S TO AROUND 70. LOWS FRIDAY NIGHT ARE EXPECTED TO RANGE FROM THE MID 20S TO MID 30S WITH LOWS SATURDAY NIGHT IN THE 30S TO AROUND 40 AND LOWS SUNDAY NIGHT AND MONDAY NIGHT IN THE UPPER 30S TO MID 40S. OVERALL EXPECT TEMPS IN THE LONG TERM PERIOD TO AVERAGE SLIGHTLY ABOVE NORMAL WITH PRECIPITATION BELOW NORMAL. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... VFR CONDITIONS ARE IN PLACE AT ALL TAF SITES WITH JUST SCT-BKN HIGH LEVEL CLOUDS ACROSS THE REGION. ALTHOUGH WINDS ARE CURRENTLY RATHER LIGHT...A SOUTHERLY BREEZE WILL INCREASE TO AROUND 10 KTS AT ALL SITES THROUGH THE AFTERNOON HOURS. AN APPROACHING COLD FRONT WILL BRING A BAND OF RAIN SHOWERS ACROSS THE REGION BETWEEN 02Z-07Z TONIGHT. THE RAIN SHOULD ONLY LAST AT ANY ONE PARTICULAR LOCATION FOR A FEW HOURS. THERE IS A SLIGHT CHC FOR SOME RUMBLES OF THUNDER...ALTHOUGH DUE TO THE UNCERTAINTY AND LOW PROBABILITY OF THIS OCCURRING...IT WILL NOT BE INCLUDED IN THE TAFS AT THIS TIME. WITHIN ANY RAIN SHOWERS...VSBYS AND PERHAPS CIGS AS WELL MAY LOWER TO MVFR RANGE. IFR CONDITIONS ARE NOT ANTICIPATED AT THIS TIME...ALTHOUGH A BRIEF DROP TO IFR CONDITIONS CANNOT BE TOTALLY RULED OUT...ESP IF ANY THUNDERSTORM DO DEVELOP. WITHIN AND JUST BEHIND THE RAIN SHOWERS...THE WINDS WILL SWITCH TO W-SW DIRECTION AND BECOME RATHER GUSTY. SOME GUSTS OF AROUND 25 KTS ARE POSSIBLE...ESP FOR KALB/KPSF. CLOUDS SHOULD START TO SCT OUT AFTER ABOUT 06Z-07Z...WITH VFR CONDITIONS RETURNING...AND SKIES WILL BE CLEAR BY MID THURSDAY MORNING. IN ADDITION...WINDS WILL DECREASE ON THURSDAY MORNING TO AROUND 5-10 KTS AFTER SUNRISE AS HIGH PRESSURE BUILDS INTO THE REGION...ALTHOUGH THERE STILL MAY BE A FEW LINGERING HIGHER WIND GUSTS AT KPSF/KALB THROUGH ABOUT NOON OR SO. OUTLOOK... THU-MON...VFR...NO SIG WX. && .FIRE WEATHER... A COLD FRONT WILL BRING SHOWERS AND ISOLATED THUNDERSTORMS TO EASTERN NEW YORK AND WESTERN NEW ENGLAND LATE THIS AFTERNOON INTO THE OVERNIGHT PERIOD. HIGH PRESSURE WILL BRIEFLY BUILD IN ON THURSDAY WITH AN UPPER LEVEL DISTURBANCE PRODUCING SOME ISOLATED TO SCATTERED RAIN AND SNOW SHOWERS. RH VALUES WILL LOWER TO 30 TO 40 PERCENT LATE THIS AFTERNOON...AND THEN RISE TO 75 TO 100 PERCENT TONIGHT. THE RH VALUES WILL DROP TO 20-30 PERCENT BY THURSDAY AFTERNOON. THE WINDS WILL INCREASE FROM THE SOUTH AT 10 TO 20 MPH WITH SOME GUSTS TO 30 MPH TODAY. THE WINDS WILL SHIFT TO THE SOUTHWEST OR WEST AT 10 TO 20 MPH TONIGHT WITH SOME GUSTS IN THE 30 TO 40 MPH RANGE WITH THE FRONTAL PASSAGE. THE WINDS WILL BE FROM THE NORTHWEST AT 10 TO 15 MPH WITH A FEW LOCATIONS HAVING GUSTS TO 25 MPH ON THURSDAY. A WETTING RAINFALL WILL OCCUR LATE THIS AFTERNOON INTO TONIGHT WITH A QUARTER TO HALF AN INCH OF RAIN EXPECTED FROM THE CAPITAL REGION...BERKSHIRES AND EASTERN CATSKILLS NORTHWARD...WITH LESS THAN A QUARTER OF AN INCH POSSIBLE FURTHER SOUTH. && .HYDROLOGY... NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED OVER THE NEXT 5 DAYS. THE NEXT WIDESPREAD RAINFALL IS EXPECTED LATE THIS AFTERNOON INTO TONIGHT. THE HPC QPF HAS LOWERED A BIT WITH GENERALLY A QUARTER TO A HALF AN INCH OF RAINFALL FROM THE CAPITAL REGION...BERKSHIRES...AND THE EASTERN CATSKILLS NORTHWARD...WITH LESS THAN A QUARTER INCH FOR MOST LOCATIONS TO THE SOUTH. SNOWMELT WILL CONTINUE ACROSS THE ADIRONDACKS AND SOUTHERN GREENS ON WEDNESDAY...DUE TO MAX TEMPS REACHING INTO THE 60S AND DEWPOINTS GETTING INTO THE 40S. DESPITE THE SNOWMELT...WHICH IS MUCH MORE LIMITED DUE TO THE SMALLER AREAL COVERAGE...THE EXPECTED RAINFALL LOOKS LIGHT ENOUGH TO AVOID ANY ISOLATED HYDROLOGIC ISSUES IN THOSE AREAS. DRY WEATHER WILL RETURN FOR THURSDAY WITH HIGH PRESSURE IN CONTROL. ISOLATED TO SCATTERED LIGHT RAIN OR SNOW SHOWERS MAY RETURN FOR THURSDAY NIGHT FOR LOCATIONS NORTH OF THE MID HUDSON VALLEY AND NW CT. RIVERS AND STREAMS WILL CONTINUE TO RECEDE WITH DRY WEATHER EXPECTED THE NEXT SEVERAL DAYS BEYOND THURSDAY NIGHT. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...FRUGIS/WASULA NEAR TERM...FRUGIS/JPV/WASULA SHORT TERM...WASULA LONG TERM...11 AVIATION...FRUGIS FIRE WEATHER...WASULA HYDROLOGY...FRUGIS/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
124 PM EDT WED APR 24 2013 .SYNOPSIS... A MILDER AIR MASS WILL YIELD ABOVE NORMAL TEMPERATURES THIS AFTERNOON BEFORE A COLD FRONT ARRIVES WITH SHOWERS...AND PERHAPS A FEW THUNDERSTORMS...IN THE EVENING. HIGH PRESSURE WILL BRIEFLY BUILD INTO THE REGION WITH SEASONABLE TEMPERATURES FOR THURSDAY. A STRONG UPPER LEVEL DISTURBANCE MAY BRING ISOLATED TO SCATTERED RAIN AND SNOW SHOWERS TO PARTS OF EASTERN NEW YORK AND WESTERN NEW ENGLAND THURSDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1040 AM EDT...WHILE MUCH OF THE REGION CURRENTLY HAS A MOSTLY SUNNY SKY...HIGH CLOUDS ARE STARTING TO SPREAD ACROSS WESTERN PARTS OF THE AREA LATE THIS MORNING AS A FRONTAL SYSTEM BEGINS TO APPROACH FROM THE WEST. A FEW RAIN SHOWERS DEVELOPED OUT WELL AHEAD OF THE COLD FRONT ACROSS WESTERN AND CENTRAL NEW YORK...BUT OUR LOCAL HIRES WRF AND THE 3KM HRRR MODEL ALL SUGGESTED THESE WOULD START TO DIMINISH AS THEY APPROACHED OUR AREA. RADAR TRENDS OVER THE LAST 30 MINUTES HAVE SUGGESTED THIS LOOKS TO BE THE CASE...SO WE HAVEN/T MADE ANY MAJOR ADJUSTMENTS TO OUR POPS ACROSS WESTERN AREAS...WITH JUST SLIGHT CHC/LOW CHC POPS FOR THE LATE MORNING/EARLY AFTN FOR WESTERN AREAS. THE NAM/GFS/ECMWF/CANADIAN GUIDANCE ARE ALL IN PRETTY GOOD AGREEMENT REGARDING THE TIMING OF THE SHOWERS ASSOCIATED WITH THE FRONT UNTIL THE MID TO LATE PM FOR THE EXTREME NW ZONES...AND THEN GRADUALLY SPREADING THEM EASTWARD FOR THE EARLY EVENING. THE BEST CHC OF SHOWERS WILL BE WEST OF THE HUDSON RIVER VALLEY PRIOR TO 6 PM. A SLIGHT CHC OF THUNDERSTORMS WAS KEPT IN FROM THE MOHAWK VALLEY SOUTHWARD DUE TO POCKETS OF ELEVATED INSTABILITY...AS THE SHOWALTER INDICES LOWER TO 0 TO -1C. THE MID LEVEL LAPSE RATES START TO STEEPEN IN THE H700-H500 RANGE TO 6.5-7.5C/KM...BUT LACK OF APPRECIABLE INSTABILITY...DEEPER MOISTURE...AND FAVORABLE MID AND UPPER LEVEL JET DYNAMICS SHOULD LIMIT THE THUNDERSTORMS THAT DUE FORM TO NON- SEVERE LEVELS. MORE DISCUSSION ON THE CONVECTION IN THE SHORT TERM. THE H850 TEMPS INCREASE +9 TO +13C AHEAD OF THE FRONT. THE H850 FLOW INCREASES FORM THE S/SW TO 40-55 KTS BY NIGHTFALL. IT WILL BECOME BREEZY IN THE PM WITH SOUTHERLY WINDS OF 10 TO 20 MPH WITH SOME GUSTS 30-35 MPH. MAX TEMPS IN THE U60S TO L70S WILL BE COMMON IN THE VALLEYS...AND 60S WILL BE LIKELY OVER THE MTNS WITH SFC DEWPTS RISING INTO THE 40S. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... TONIGHT...THE BEST CHC FOR WIDESPREAD RAINFALL FROM THE FRONT LOOKS TO BE IN THE 6 PM TO MIDNIGHT TIME FRAME. THERE IS DECENT LOW-LEVEL CONVERGENCE ALONG AND IN THE WAKE OF THE COLD FRONT. THE BETTER JET STREAK ALOFT RACES INTO QUEBEC...AS THE UNFAVORABLE RIGHT FRONT QUAD OF A 125+ KT H250 JET STREAK MOVES OVER THE SRN HALF OF THE FCST AREA...WHICH WILL DAMPEN THE PCPN A BIT SOUTH AND EAST OF THE CAPITAL REGION. THE THREAT FOR ISOLATED THUNDERSTORMS WAS KEPT IN UNTIL MIDNIGHT FROM THE CAPITAL REGION...MOHAWK VALLEY...BERKSHIRES SOUTH. POPS WERE INCREASED TO LIKELY AND CATEGORICAL VALUES. THE STEEPENING MID LEVEL LAPSE RATES...AND STRENGTHENING LOW LEVEL JET ASSOCIATED WITH THE FRONT WARRANTED PUTTING SOME WIND GUSTS TO 30 TO 40 MPH...ESPECIALLY JUST IN THE WAKE OF THE FRONT. THE PWATS DO EXCEED AN INCH FOR A BRIEF PERIOD OF TIME /COUPLE STANDARD DEVIATIONS ABOVE NORMAL/...BUT DROP OFF WITH THE BLAST OF COLD ADVECTION THAT FOLLOWS THE FRONTAL PASSAGE. QPF WILL RANGE FROM A TENTH OF AN INCH OR SO...OVER THE SOUTHEAST CORNER OF THE FCST AREA...TO UP TO A HALF AN INCH OVER THE NW EXTREME. SOME OF THE RESIDUAL POST FRONTAL SHOWERS OVER THE SRN DACKS MAY TRANSITION TO SNOW SHOWERS WITH LIGHT COATINGS TO A FEW TENTHS OF AN INCH IN A FEW SPOTS. MIN TEMPS ARE TRICKY TIMING THE COLD ADVECTION. THERE ARE LARGE DIFFERENCE BTWN THE NAM AND GFSMOS. THE GFS IS MUCH COLDER BY ALMOST 10 DEGREES IN SOME LOCATIONS. LEANED CLOSER TO THE WARMER NAM MOS GUIDANCE DUE TO ITS TRACK RECORD LATELY...AND ACTUALLY WENT CLOSE TO THE ECM MOS GUIDANCE. LOWS EXPECTED IN THE L40S IN THE HUDSON RIVER VALLEY...BERKS...CT RIVER VALLEY AND NW CT...MID AND U30S ELSEWHERE...EXCEPT SOME U20S TO L30S OVER THE SRN DACKS. THURSDAY...HIGH PRESSURE QUICKLY RIDGES IN FROM THE SOUTH AND WEST WITH A BRIEF PERIOD OF DRY WEATHER...AS A POTENT SHORT-WAVE TROUGH QUICKLY MOVES TOWARDS THE REGION FROM THE GREAT LAKES REGION. THIS DAY WILL BE SEASONABLY WARM AND DRY WITH H850 TEMPS IN THE 0C TO -4C RANGE OVER THE REGION. EXPECT U50S TO L60S IN THE VALLEYS...AND U40S TO M50S OVER THE HIGHER TERRAIN. THURSDAY NIGHT...TRICKY DYNAMIC SHORT-WAVE LACKING ROBUST LOW- LEVEL MOISTURE TO WORK WITH. THE NAM HAS THE TROUGH PASS THROUGH FAIRLY DRY. THE GFS/ECMWF CONTINUE TO PAINT LIGHT AMOUNTS OF QPF OF A FEW HUNDREDTHS TO A TENTH OF AN INCH FROM THE ERN CATSKILLS...CAPITAL REGION...NRN BERKS NORTHWARD. THE DIFFERENTIAL CYCLONIC VORTICITY WILL TRIGGER SOME ISOLD-SCT RAIN AND SNOW SHOWERS. THERE WILL LIKELY BE A QUICK SHOT OF RADIATIONAL COOLING AHEAD OF THIS POTENT SHORT-WAVE WITH TEMPS FALLING INTO THE M20S TO M30S ACROSS THE REGION. COATING TO HALF INCH SNOW AMOUNTS WILL BE POSSIBLE ESPECIALLY FOR ELEVATIONS 500 FT AND GREATER...A LITTLE WET SNOW MIGHT ALSO OCCUR AT THE VALLEY FLOOR LOCATIONS. FRIDAY...LOW AND MID LEVEL HEIGHTS QUICKLY RISE AS THE SHORT-WAVE TROUGH ZIPS BY NRN NEW ENGLAND BY THE PM. SFC HIGH PRESSURE BUILDS IN FROM THE OHIO VALLEY...AND THE GREAT LAKES REGION WITH FAIR AND DRY WX FOR THE AFTERNOON. EXPECT HIGHS IN THE L60S IN THE CAPITAL REGION...MID HUDSON VALLEY...CNTRL AND SRN TACONICS...AND NW CT. MID AND U50S WILL PREVAIL IN ALL OTHER LOCATIONS. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... RATHER UNUSUAL TO BE FORECASTING AN ENTIRELY DRY LONG TERM PERIOD...HOWEVER THAT IS THE CASE WITH THIS LONG TERM FORECAST. HIGH PRESSURE WILL DOMINATE OUR WEATHER INITIALLY BUILDING AT THE SURFACE AND THEN ALOFT AS WELL BY MONDAY AND TUESDAY. THE STRENGTHENING HIGH PRESSURE SYSTEM WILL KEEP ANY MOISTURE WHICH TRIES TO LIFT NORTHWARD WELL SOUTH OF OUR REGION. EXPECT HIGHS ON SATURDAY TO BE IN THE UPPER 50S TO MID 60S WITH HIGHS SUNDAY THROUGH TUESDAY MAINLY IN THE 60S TO AROUND 70. LOWS FRIDAY NIGHT ARE EXPECTED TO RANGE FROM THE MID 20S TO MID 30S WITH LOWS SATURDAY NIGHT IN THE 30S TO AROUND 40 AND LOWS SUNDAY NIGHT AND MONDAY NIGHT IN THE UPPER 30S TO MID 40S. OVERALL EXPECT TEMPS IN THE LONG TERM PERIOD TO AVERAGE SLIGHTLY ABOVE NORMAL WITH PRECIPITATION BELOW NORMAL. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... VFR CONDITIONS ARE IN PLACE AT ALL TAF SITES WITH JUST SCT-BKN HIGH LEVEL CLOUDS ACROSS THE REGION. ALTHOUGH WINDS ARE CURRENTLY RATHER LIGHT...A SOUTHERLY BREEZE WILL INCREASE TO AROUND 10 KTS AT ALL SITES THROUGH THE AFTERNOON HOURS. AN APPROACHING COLD FRONT WILL BRING A BAND OF RAIN SHOWERS ACROSS THE REGION BETWEEN 02Z-07Z TONIGHT. THE RAIN SHOULD ONLY LAST AT ANY ONE PARTICULAR LOCATION FOR A FEW HOURS. THERE IS A SLIGHT CHC FOR SOME RUMBLES OF THUNDER...ALTHOUGH DUE TO THE UNCERTAINTY AND LOW PROBABILITY OF THIS OCCURRING...IT WILL NOT BE INCLUDED IN THE TAFS AT THIS TIME. WITHIN ANY RAIN SHOWERS...VSBYS AND PERHAPS CIGS AS WELL MAY LOWER TO MVFR RANGE. IFR CONDITIONS ARE NOT ANTICIPATED AT THIS TIME...ALTHOUGH A BRIEF DROP TO IFR CONDITIONS CANNOT BE TOTALLY RULED OUT...ESP IF ANY THUNDERSTORM DO DEVELOP. WITHIN AND JUST BEHIND THE RAIN SHOWERS...THE WINDS WILL SWITCH TO W-SW DIRECTION AND BECOME RATHER GUSTY. SOME GUSTS OF AROUND 25 KTS ARE POSSIBLE...ESP FOR KALB/KPSF. CLOUDS SHOULD START TO SCT OUT AFTER ABOUT 06Z-07Z...WITH VFR CONDITIONS RETURNING...AND SKIES WILL BE CLEAR BY MID THURSDAY MORNING. IN ADDITION...WINDS WILL DECREASE ON THURSDAY MORNING TO AROUND 5-10 KTS AFTER SUNRISE AS HIGH PRESSURE BUILDS INTO THE REGION...ALTHOUGH THERE STILL MAY BE A FEW LINGERING HIGHER WIND GUSTS AT KPSF/KALB THROUGH ABOUT NOON OR SO. OUTLOOK... THU-MON...VFR...NO SIG WX. && .FIRE WEATHER... A COLD FRONT WILL BRING SHOWERS AND ISOLATED THUNDERSTORMS TO EASTERN NEW YORK AND WESTERN NEW ENGLAND LATE THIS AFTERNOON INTO THE OVERNIGHT PERIOD. HIGH PRESSURE WILL BRIEFLY BUILD IN ON THURSDAY WITH AN UPPER LEVEL DISTURBANCE PRODUCING SOME ISOLATED TO SCATTERED RAIN AND SNOW SHOWERS. RH VALUES WILL LOWER TO 30 TO 40 PERCENT LATE THIS AFTERNOON...AND THEN RISE TO 75 TO 100 PERCENT TONIGHT. THE RH VALUES WILL DROP TO 20-30 PERCENT BY THURSDAY AFTERNOON. THE WINDS WILL INCREASE FROM THE SOUTH AT 10 TO 20 MPH WITH SOME GUSTS TO 30 MPH TODAY. THE WINDS WILL SHIFT TO THE SOUTHWEST OR WEST AT 10 TO 20 MPH TONIGHT WITH SOME GUSTS IN THE 30 TO 40 MPH RANGE WITH THE FRONTAL PASSAGE. THE WINDS WILL BE FROM THE NORTHWEST AT 10 TO 15 MPH WITH A FEW LOCATIONS HAVING GUSTS TO 25 MPH ON THURSDAY. A WETTING RAINFALL WILL OCCUR LATE THIS AFTERNOON INTO TONIGHT WITH A QUARTER TO HALF AN INCH OF RAIN EXPECTED FROM THE CAPITAL REGION...BERKSHIRES AND EASTERN CATSKILLS NORTHWARD...WITH LESS THAN A QUARTER OF AN INCH POSSIBLE FURTHER SOUTH. && .HYDROLOGY... NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED OVER THE NEXT 5 DAYS. THE NEXT WIDESPREAD RAINFALL IS EXPECTED LATE THIS AFTERNOON INTO TONIGHT. THE HPC QPF HAS LOWERED A BIT WITH GENERALLY A QUARTER TO A HALF AN INCH OF RAINFALL FROM THE CAPITAL REGION...BERKSHIRES...AND THE EASTERN CATSKILLS NORTHWARD...WITH LESS THAN A QUARTER INCH FOR MOST LOCATIONS TO THE SOUTH. SNOWMELT WILL CONTINUE ACROSS THE ADIRONDACKS AND SOUTHERN GREENS ON WEDNESDAY...DUE TO MAX TEMPS REACHING INTO THE 60S AND DEWPOINTS GETTING INTO THE 40S. DESPITE THE SNOWMELT...WHICH IS MUCH MORE LIMITED DUE TO THE SMALLER AREAL COVERAGE...THE EXPECTED RAINFALL LOOKS LIGHT ENOUGH TO AVOID ANY ISOLATED HYDROLOGIC ISSUES IN THOSE AREAS. DRY WEATHER WILL RETURN FOR THURSDAY WITH HIGH PRESSURE IN CONTROL. ISOLATED TO SCATTERED LIGHT RAIN OR SNOW SHOWERS MAY RETURN FOR THURSDAY NIGHT FOR LOCATIONS NORTH OF THE MID HUDSON VALLEY AND NW CT. RIVERS AND STREAMS WILL CONTINUE TO RECEDE WITH DRY WEATHER EXPECTED THE NEXT SEVERAL DAYS BEYOND THURSDAY NIGHT. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...FRUGIS/WASULA NEAR TERM...FRUGIS/WASULA SHORT TERM...WASULA LONG TERM...11 AVIATION...FRUGIS FIRE WEATHER...WASULA HYDROLOGY...FRUGIS/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1040 AM EDT WED APR 24 2013 .SYNOPSIS... A MILDER AIR MASS WILL YIELD ABOVE NORMAL TEMPERATURES THIS AFTERNOON BEFORE A COLD FRONT ARRIVES WITH SHOWERS...AND PERHAPS A FEW THUNDERSTORMS...IN THE EVENING. HIGH PRESSURE WILL BRIEFLY BUILD INTO THE REGION WITH SEASONABLE TEMPERATURES FOR THURSDAY. A STRONG UPPER LEVEL DISTURBANCE MAY BRING ISOLATED TO SCATTERED RAIN AND SNOW SHOWERS TO PARTS OF EASTERN NEW YORK AND WESTERN NEW ENGLAND THURSDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1040 AM EDT...WHILE MUCH OF THE REGION CURRENTLY HAS A MOSTLY SUNNY SKY...HIGH CLOUDS ARE STARTING TO SPREAD ACROSS WESTERN PARTS OF THE AREA LATE THIS MORNING AS A FRONTAL SYSTEM BEGINS TO APPROACH FROM THE WEST. A FEW RAIN SHOWERS DEVELOPED OUT WELL AHEAD OF THE COLD FRONT ACROSS WESTERN AND CENTRAL NEW YORK...BUT OUR LOCAL HIRES WRF AND THE 3KM HRRR MODEL ALL SUGGESTED THESE WOULD START TO DIMINISH AS THEY APPROACHED OUR AREA. RADAR TRENDS OVER THE LAST 30 MINUTES HAVE SUGGESTED THIS LOOKS TO BE THE CASE...SO WE HAVEN/T MADE ANY MAJOR ADJUSTMENTS TO OUR POPS ACROSS WESTERN AREAS...WITH JUST SLIGHT CHC/LOW CHC POPS FOR THE LATE MORNING/EARLY AFTN FOR WESTERN AREAS. THE NAM/GFS/ECMWF/CANADIAN GUIDANCE ARE ALL IN PRETTY GOOD AGREEMENT REGARDING THE TIMING OF THE SHOWERS ASSOCIATED WITH THE FRONT UNTIL THE MID TO LATE PM FOR THE EXTREME NW ZONES...AND THEN GRADUALLY SPREADING THEM EASTWARD FOR THE EARLY EVENING. THE BEST CHC OF SHOWERS WILL BE WEST OF THE HUDSON RIVER VALLEY PRIOR TO 6 PM. A SLIGHT CHC OF THUNDERSTORMS WAS KEPT IN FROM THE MOHAWK VALLEY SOUTHWARD DUE TO POCKETS OF ELEVATED INSTABILITY...AS THE SHOWALTER INDICES LOWER TO 0 TO -1C. THE MID LEVEL LAPSE RATES START TO STEEPEN IN THE H700-H500 RANGE TO 6.5-7.5C/KM...BUT LACK OF APPRECIABLE INSTABILITY...DEEPER MOISTURE...AND FAVORABLE MID AND UPPER LEVEL JET DYNAMICS SHOULD LIMIT THE THUNDERSTORMS THAT DUE FORM TO NON- SEVERE LEVELS. MORE DISCUSSION ON THE CONVECTION IN THE SHORT TERM. THE H850 TEMPS INCREASE +9 TO +13C AHEAD OF THE FRONT. THE H850 FLOW INCREASES FORM THE S/SW TO 40-55 KTS BY NIGHTFALL. IT WILL BECOME BREEZY IN THE PM WITH SOUTHERLY WINDS OF 10 TO 20 MPH WITH SOME GUSTS 30-35 MPH. MAX TEMPS IN THE U60S TO L70S WILL BE COMMON IN THE VALLEYS...AND 60S WILL BE LIKELY OVER THE MTNS WITH SFC DEWPTS RISING INTO THE 40S. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... TONIGHT...THE BEST CHC FOR WIDESPREAD RAINFALL FROM THE FRONT LOOKS TO BE IN THE 6 PM TO MIDNIGHT TIME FRAME. THERE IS DECENT LOW-LEVEL CONVERGENCE ALONG AND IN THE WAKE OF THE COLD FRONT. THE BETTER JET STREAK ALOFT RACES INTO QUEBEC...AS THE UNFAVORABLE RIGHT FRONT QUAD OF A 125+ KT H250 JET STREAK MOVES OVER THE SRN HALF OF THE FCST AREA...WHICH WILL DAMPEN THE PCPN A BIT SOUTH AND EAST OF THE CAPITAL REGION. THE THREAT FOR ISOLATED THUNDERSTORMS WAS KEPT IN UNTIL MIDNIGHT FROM THE CAPITAL REGION...MOHAWK VALLEY...BERKSHIRES SOUTH. POPS WERE INCREASED TO LIKELY AND CATEGORICAL VALUES. THE STEEPENING MID LEVEL LAPSE RATES...AND STRENGTHENING LOW LEVEL JET ASSOCIATED WITH THE FRONT WARRANTED PUTTING SOME WIND GUSTS TO 30 TO 40 MPH...ESPECIALLY JUST IN THE WAKE OF THE FRONT. THE PWATS DO EXCEED AN INCH FOR A BRIEF PERIOD OF TIME /COUPLE STANDARD DEVIATIONS ABOVE NORMAL/...BUT DROP OFF WITH THE BLAST OF COLD ADVECTION THAT FOLLOWS THE FRONTAL PASSAGE. QPF WILL RANGE FROM A TENTH OF AN INCH OR SO...OVER THE SOUTHEAST CORNER OF THE FCST AREA...TO UP TO A HALF AN INCH OVER THE NW EXTREME. SOME OF THE RESIDUAL POST FRONTAL SHOWERS OVER THE SRN DACKS MAY TRANSITION TO SNOW SHOWERS WITH LIGHT COATINGS TO A FEW TENTHS OF AN INCH IN A FEW SPOTS. MIN TEMPS ARE TRICKY TIMING THE COLD ADVECTION. THERE ARE LARGE DIFFERENCE BTWN THE NAM AND GFSMOS. THE GFS IS MUCH COLDER BY ALMOST 10 DEGREES IN SOME LOCATIONS. LEANED CLOSER TO THE WARMER NAM MOS GUIDANCE DUE TO ITS TRACK RECORD LATELY...AND ACTUALLY WENT CLOSE TO THE ECM MOS GUIDANCE. LOWS EXPECTED IN THE L40S IN THE HUDSON RIVER VALLEY...BERKS...CT RIVER VALLEY AND NW CT...MID AND U30S ELSEWHERE...EXCEPT SOME U20S TO L30S OVER THE SRN DACKS. THURSDAY...HIGH PRESSURE QUICKLY RIDGES IN FROM THE SOUTH AND WEST WITH A BRIEF PERIOD OF DRY WEATHER...AS A POTENT SHORT-WAVE TROUGH QUICKLY MOVES TOWARDS THE REGION FROM THE GREAT LAKES REGION. THIS DAY WILL BE SEASONABLY WARM AND DRY WITH H850 TEMPS IN THE 0C TO -4C RANGE OVER THE REGION. EXPECT U50S TO L60S IN THE VALLEYS...AND U40S TO M50S OVER THE HIGHER TERRAIN. THURSDAY NIGHT...TRICKY DYNAMIC SHORT-WAVE LACKING ROBUST LOW- LEVEL MOISTURE TO WORK WITH. THE NAM HAS THE TROUGH PASS THROUGH FAIRLY DRY. THE GFS/ECMWF CONTINUE TO PAINT LIGHT AMOUNTS OF QPF OF A FEW HUNDREDTHS TO A TENTH OF AN INCH FROM THE ERN CATSKILLS...CAPITAL REGION...NRN BERKS NORTHWARD. THE DIFFERENTIAL CYCLONIC VORTICITY WILL TRIGGER SOME ISOLD-SCT RAIN AND SNOW SHOWERS. THERE WILL LIKELY BE A QUICK SHOT OF RADIATIONAL COOLING AHEAD OF THIS POTENT SHORT-WAVE WITH TEMPS FALLING INTO THE M20S TO M30S ACROSS THE REGION. COATING TO HALF INCH SNOW AMOUNTS WILL BE POSSIBLE ESPECIALLY FOR ELEVATIONS 500 FT AND GREATER...A LITTLE WET SNOW MIGHT ALSO OCCUR AT THE VALLEY FLOOR LOCATIONS. FRIDAY...LOW AND MID LEVEL HEIGHTS QUICKLY RISE AS THE SHORT-WAVE TROUGH ZIPS BY NRN NEW ENGLAND BY THE PM. SFC HIGH PRESSURE BUILDS IN FROM THE OHIO VALLEY...AND THE GREAT LAKES REGION WITH FAIR AND DRY WX FOR THE AFTERNOON. EXPECT HIGHS IN THE L60S IN THE CAPITAL REGION...MID HUDSON VALLEY...CNTRL AND SRN TACONICS...AND NW CT. MID AND U50S WILL PREVAIL IN ALL OTHER LOCATIONS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... RATHER UNUSUAL TO BE FORECASTING AN ENTIRELY DRY LONG TERM PERIOD...HOWEVER THAT IS THE CASE WITH THIS LONG TERM FORECAST. HIGH PRESSURE WILL DOMINATE OUR WEATHER INITIALLY BUILDING AT THE SURFACE AND THEN ALOFT AS WELL BY MONDAY AND TUESDAY. THE STRENGTHENING HIGH PRESSURE SYSTEM WILL KEEP ANY MOISTURE WHICH TRIES TO LIFT NORTHWARD WELL SOUTH OF OUR REGION. EXPECT HIGHS ON SATURDAY TO BE IN THE UPPER 50S TO MID 60S WITH HIGHS SUNDAY THROUGH TUESDAY MAINLY IN THE 60S TO AROUND 70. LOWS FRIDAY NIGHT ARE EXPECTED TO RANGE FROM THE MID 20S TO MID 30S WITH LOWS SATURDAY NIGHT IN THE 30S TO AROUND 40 AND LOWS SUNDAY NIGHT AND MONDAY NIGHT IN THE UPPER 30S TO MID 40S. OVERALL EXPECT TEMPS IN THE LONG TERM PERIOD TO AVERAGE SLIGHTLY ABOVE NORMAL WITH PRECIPITATION BELOW NORMAL. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... FOR THE TAF SITES EXPECT MAINLY VFR CONDITIONS AS COASTAL LOW PULLS AWAY FROM THE REGION EARLY THIS MORNING. THE EXCEPTION WILL BE AT KPSF WHERE LOW STRATUS WILL RESULT IN MVFR TO PERHAPS IFR CONDITIONS UNTIL AROUND 14Z. AHEAD OF THE COLD FRONT WHICH WILL BE MOVING THROUGH THE TAF SITES THIS EVENING...EXPECT ONLY MID AND HIGH CLOUDS THROUGH MUCH OF THIS AFTERNOON. SHOWERS ARE EXPECTED TO ARRIVE LATE THIS AFTERNOON OR EARLY THIS EVENING WITH VSBYS 3-6SM AND CIGS GENERALLY OVC035-050 EXCEPT MVFR CIGS PSBL AT KPSF. THE SHOWERS ARE EXPECTED TO END LATE TONIGHT WITH A RETURN TO VFR CONDITIONS AS CLOUDS BREAK UP WINDS WILL GENERALLY BE SOUTH INCREASING TO 10 KTS THIS MORNING WITH GUSTS 20-25 KTS THIS AFTERNOON. WINDS WILL SHIFT TO THE SOUTHWEST AND THEN WEST IN WAKE OF COLD FRONT THIS EVENING AND REMAIN FAIRLY STRONG AND GUSTY ESPECIALLY AT KALB. WINDS LATE TONIGHT WILL BE WEST TO NORTHWEST AT 8-12 KTS. OUTLOOK... THU-SUN...VFR...NO SIG WX. && .FIRE WEATHER... A COLD FRONT WILL BRING SHOWERS AND ISOLATED THUNDERSTORMS TO EASTERN NEW YORK AND WESTERN NEW ENGLAND LATE THIS AFTERNOON INTO THE OVERNIGHT PERIOD. HIGH PRESSURE WILL BRIEFLY BUILD IN ON THURSDAY WITH AN UPPER LEVEL DISTURBANCE PRODUCING SOME ISOLATED TO SCATTERED RAIN AND SNOW SHOWERS. RH VALUES WILL LOWER TO 30 TO 40 PERCENT LATE THIS AFTERNOON...AND THEN RISE TO 75 TO 100 PERCENT TONIGHT. THE RH VALUES WILL DROP TO 20-30 PERCENT BY THURSDAY AFTERNOON. THE WINDS WILL INCREASE FROM THE SOUTH AT 10 TO 20 MPH WITH SOME GUSTS TO 30 MPH TODAY. THE WINDS WILL SHIFT TO THE SOUTHWEST OR WEST AT 10 TO 20 MPH TONIGHT WITH SOME GUSTS IN THE 30 TO 40 MPH RANGE WITH THE FRONTAL PASSAGE. THE WINDS WILL BE FROM THE NORTHWEST AT 10 TO 15 MPH WITH A FEW LOCATIONS HAVING GUSTS TO 25 MPH ON THURSDAY. A WETTING RAINFALL WILL OCCUR LATE THIS AFTERNOON INTO TONIGHT WITH A QUARTER TO HALF AN INCH OF RAIN EXPECTED FROM THE CAPITAL REGION...BERKSHIRES AND EASTERN CATSKILLS NORTHWARD...WITH LESS THAN A QUARTER OF AN INCH POSSIBLE FURTHER SOUTH. && .HYDROLOGY... NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED OVER THE NEXT 5 DAYS. THE NEXT WIDESPREAD RAINFALL IS EXPECTED LATE THIS AFTERNOON INTO TONIGHT. THE HPC QPF HAS LOWERED A BIT WITH GENERALLY A QUARTER TO A HALF AN INCH OF RAINFALL FROM THE CAPITAL REGION...BERKSHIRES...AND THE EASTERN CATSKILLS NORTHWARD...WITH LESS THAN A QUARTER INCH FOR MOST LOCATIONS TO THE SOUTH. SNOWMELT WILL CONTINUE ACROSS THE ADIRONDACKS AND SOUTHERN GREENS ON WEDNESDAY...DUE TO MAX TEMPS REACHING INTO THE 60S AND DEWPOINTS GETTING INTO THE 40S. DESPITE THE SNOWMELT...WHICH IS MUCH MORE LIMITED DUE TO THE SMALLER AREAL COVERAGE...THE EXPECTED RAINFALL LOOKS LIGHT ENOUGH TO AVOID ANY ISOLATED HYDROLOGIC ISSUES IN THOSE AREAS. DRY WEATHER WILL RETURN FOR THURSDAY WITH HIGH PRESSURE IN CONTROL. ISOLATED TO SCATTERED LIGHT RAIN OR SNOW SHOWERS MAY RETURN FOR THURSDAY NIGHT FOR LOCATIONS NORTH OF THE MID HUDSON VALLEY AND NW CT. RIVERS AND STREAMS WILL CONTINUE TO RECEDE WITH DRY WEATHER EXPECTED THE NEXT SEVERAL DAYS BEYOND THURSDAY NIGHT. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...FRUGIS/WASULA NEAR TERM...FRUGIS/WASULA SHORT TERM...WASULA LONG TERM...11 AVIATION...11 FIRE WEATHER...WASULA HYDROLOGY...FRUGIS/WASULA
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1240 PM CDT WED APR 24 2013 .DISCUSSION... ISSUED 954 AM CDT WED APR 24 2013 SATELLITE IMAGERY SHOWING THE BACK EDGE OF THE CLOUDS STARTING TO APPROACH THE ILLINOIS RIVER. LATEST GUIDANCE FROM THE RAP SHOWS A BIT OF SLOWING DOWN OF THE CLEARING THROUGH MIDDAY...WITH THE EASTERN CWA STILL HAVING A FAIR AMOUNT OF CLOUDINESS INTO EARLY AFTERNOON. THE LINGERING RAIN AND SNOW SHOWERS IN THE EASTERN CWA STILL ON TRACK TO EXIT THE AREA OVER THE NEXT COUPLE HOURS. FORECAST IS GENERALLY ON TRACK. HAVE SENT SOME MINOR GRID UPDATES TO REFRESH THE CURRENT TRENDS...BUT WILL HOLD OFF A BIT LONGER ON UPDATING THE ZONE FORECASTS UNTIL THE PRECIP HAS EXITED THE AREA. GEELHART && .AVIATION... ISSUED 1239 PM CDT WED APR 24 2013 MVFR CONDITIONS HAVE NOW PUSHED EAST OF ALL CENTRAL ILLINOIS TAF SITES...BUT EXTENSIVE DIURNAL CUMULUS DEVELOPMENT WILL KEEP CEILINGS AROUND 4000 FEET THROUGH THE AFTERNOON. A FAST MOVING FRONTAL BOUNDARY WILL PASS TO THE NORTH OVERNIGHT. MAY SEE A FEW SHOWERS COME CLOSE TO KPIA/KBMI LATE TONIGHT...BUT CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE IN THE TAFS AT THIS POINT. BEHIND THE FRONT...MORE DIURNAL DEVELOPMENT IS EXPECTED THURSDAY MORNING... WITH SOUNDINGS CURRENTLY INDICATING CEILINGS STAYING JUST ABOVE THE MVFR RANGE. GEELHART && .PREV DISCUSSION... ISSUED 330 AM CDT WED APR 24 2013 00Z MODELS ARE IN FAIR AGREEMENT NEXT FEW DAYS AND WILL USE A BLEND. MET AND MAV GUIDANCE TEMPS SIMILAR THROUGH FRIDAY AND STAYED CLOSE TO. SHORT TERM...TODAY THROUGH SATURDAY WIDESPREAD BAND OF SHOWERS AND ISOLATED THUNDERSTORMS WAS SE OF A DANVILLE TO SHELBYVILLE LINE EARLY THIS MORNING WITH PERIODS OF MODERATE TO HEAVY RAIN SHOWERS AT TIMES. CUMBERLAND AND EFFINGHAM COUNTIES HAVE AN URBAN AND SMALL STREAM FLOOD ADVISORY UNTIL 10 AM. SHOWERS WILL GRADUALLY DIMINISH OVER SE IL DURING THIS MORNING AND COULD STILL SEE A FEW SNOWFLAKES INTO MID MORNING ON NW EDGE OF THIS PRECIPITATION. TEMPS CURRENTLY IN THE UPPER 30S OVER CENTRAL IL AND 40-45F IN SE IL WITH BLUSTERY NNW WINDS 10-20 MPH. 1007 MB LOW PRESSURE WAS DEEPENING OVER NW OHIO WITH ITS COLD FRONT INTO NW KY/TN. 1028 MB HIGH PRESSURE WAS OVER NORTH TEXAS AND WESTERN OK INTO SE CO. SLOWED DOWN THE CLEARING OF LOW CLOUDS TODAY AS A STRONG SHORT WAVE OVER THE CENTRAL PLAINS MOVES EAST INTO IL BY 18Z TODAY THEN EXITS QUICKLY NE OF IL DURING THE AFTERNOON WHEN LOW CLOUDS WILL DECREASE. HIGHS IN THE LOWER 50S WITH SOME UPPER 40S OVER EAST CENTRAL IL. WEAK LOW PRESSURE AROUND 1015 MB MOVES INTO THE NORTHERN GREAT LAKES BY DAWN THU AND BRINGS A WEAK COLD FRONT INTO CENTRAL IL WHILE ANOTHER FAIRLY STRONG SHORT WAVE/TROF DIGS INTO LAKE MI. THIS TO KEEP BRUNT OF MIXED LIGHT PRECIPITATION NORTH OF CENTRAL IL WITH JUST SLIGHT CHANCES BETWEEN 10 PM AND 4 AM NORTH OF PEORIA. LOWS IN THE MID TO UPPER 30S AGAIN TONIGHT. 1027 MB HIGH PRESSURE BUILDS INTO THE MID MS VALLEY BY SUNSET THU BRINGING MORE SUNSHINE AND HIGHS IN THE MID TO UPPER 50S. LOWS THU NIGHT IN THE UPPER 30S TO NEAR 40F WITH COOLEST READINGS IN EAST CENTRAL IL WHERE MID 30S POSSIBLE. WEATHER SYSTEM EJECTS EAST FROM THE SOUTHERN PLAINS INTO THE TN VALLEY FRI/SAT AND KEEPS THE BRUNT OF ITS SHOWERS SOUTH OF CENTRAL IL. GFS HAS TRENDED FURTHER SOUTH WITH THE QPF FIELDS AND MORE CONFIDENCE OF A DRY FORECAST ON FRIDAY WITH HIGHS IN THE LOWER 60S. HAVE 20-30% CHANCE OF SHOWERS FROM I-70 SOUTH FRIDAY NIGHT AND SAT WITH HIGHEST POPS IN SE IL WITH THUNDER CHANCES STAYING SOUTH OF I-64. HIGHS SAT IN THE MID 60S. LONG TERM...SATURDAY NIGHT THROUGH TUESDAY NIGHT GENERALLY DRY AND MILDER WEATHER EXPECTED SUNDAY AND MONDAY AS SYSTEM EXITS EAST OF IL SUNDAY...WITH HIGHS AROUND 70F SUNDAY AND MID 70S MONDAY. GFS BRINGS PATCHES OF LIGHT QPF INTO IL SUNDAY BUT THINK THIS WILL BE MORE TO OUR SE AS UPPER LEVEL RIDGE BUILDING INTO IL. AN UPPER LEVEL TROF DIGGING INTO THE NORTHERN PLAINS TUE TO PUSH A FRONTAL BOUNDARY SE INTO IA TUE WITH GFS QUICKER WITH COLD FRONT THAN ECMWF. WILL GO WITH ALLBLEND SLIGHT CHANCE POPS OF SHOWERS AND THUNDERSTORMS TUE AND TUE NIGHT. STILL IN THE 70S FOR HIGHS TUE WITH CENTRAL/SE IL AHEAD OF THE COLD FRONT. 07 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
957 AM CDT WED APR 24 2013 .DISCUSSION... ISSUED 954 AM CDT WED APR 24 2013 SATELLITE IMAGERY SHOWING THE BACK EDGE OF THE CLOUDS STARTING TO APPROACH THE ILLINOIS RIVER. LATEST GUIDANCE FROM THE RAP SHOWS A BIT OF SLOWING DOWN OF THE CLEARING THROUGH MIDDAY...WITH THE EASTERN CWA STILL HAVING A FAIR AMOUNT OF CLOUDINESS INTO EARLY AFTERNOON. THE LINGERING RAIN AND SNOW SHOWERS IN THE EASTERN CWA STILL ON TRACK TO EXIT THE AREA OVER THE NEXT COUPLE HOURS. FORECAST IS GENERALLY ON TRACK. HAVE SENT SOME MINOR GRID UPDATES TO REFRESH THE CURRENT TRENDS...BUT WILL HOLD OFF A BIT LONGER ON UPDATING THE ZONE FORECASTS UNTIL THE PRECIP HAS EXITED THE AREA. GEELHART && .AVIATION... ISSUED 649 AM CDT WED APR 24 2013...FOR THE 12Z TAFS POST FRONTAL PRECIP WILL GRADUALLY DIMINISH THIS MORNING AS DRY AIR ALOFT BEGINS TO ERODE THE LOW LEVEL MOIST LAYER. SPRINKLES OR DRIZZLE WILL CONTINUE FOR THE FIRST 2 TO 4 HOURS OF THIS TAF PERIOD. THERE MAY EVEN BE SNOW SNOW FLURRIES AS THE COLD AIR ALOFT CONTINUES TO COOL DOWN FARTHER BELOW FREEZING. NO SNOW ACCUM WILL OCCUR. IFR CLOUD HEIGHTS IN BMI SHOULD LIFT TO MVFR BY 14Z...WHILE THE OTHER SITES REMAIN AT MVFR UNTIL 18Z TO 21Z FROM WEST TO EAST. THE CLEARING LINE OF CLOUDS SHOULD PROGRESS EASTWARD AT A STEADY PACE TODAY AS THE UPPER FLOW BEGINS TO BECOME MORE PERPENDICULAR TO THE LOWER LEVEL FRONT. WINDS WILL REMAIN NORTHWEST TODAY IN THE 12-15KT RANGE...THEN BECOME LIGHT SOUTHWEST TONIGHT AS THE SURFACE RIDGE BUILDS INTO IL FROM THE WEST. SHIMON && .PREV DISCUSSION... ISSUED 330 AM CDT WED APR 24 2013 00Z MODELS ARE IN FAIR AGREEMENT NEXT FEW DAYS AND WILL USE A BLEND. MET AND MAV GUIDANCE TEMPS SIMILAR THROUGH FRIDAY AND STAYED CLOSE TO. SHORT TERM...TODAY THROUGH SATURDAY WIDESPREAD BAND OF SHOWERS AND ISOLATED THUNDERSTORMS WAS SE OF A DANVILLE TO SHELBYVILLE LINE EARLY THIS MORNING WITH PERIODS OF MODERATE TO HEAVY RAIN SHOWERS AT TIMES. CUMBERLAND AND EFFINGHAM COUNTIES HAVE AN URBAN AND SMALL STREAM FLOOD ADVISORY UNTIL 10 AM. SHOWERS WILL GRADUALLY DIMINISH OVER SE IL DURING THIS MORNING AND COULD STILL SEE A FEW SNOWFLAKES INTO MID MORNING ON NW EDGE OF THIS PRECIPITATION. TEMPS CURRENTLY IN THE UPPER 30S OVER CENTRAL IL AND 40-45F IN SE IL WITH BLUSTERY NNW WINDS 10-20 MPH. 1007 MB LOW PRESSURE WAS DEEPENING OVER NW OHIO WITH ITS COLD FRONT INTO NW KY/TN. 1028 MB HIGH PRESSURE WAS OVER NORTH TEXAS AND WESTERN OK INTO SE CO. SLOWED DOWN THE CLEARING OF LOW CLOUDS TODAY AS A STRONG SHORT WAVE OVER THE CENTRAL PLAINS MOVES EAST INTO IL BY 18Z TODAY THEN EXITS QUICKLY NE OF IL DURING THE AFTERNOON WHEN LOW CLOUDS WILL DECREASE. HIGHS IN THE LOWER 50S WITH SOME UPPER 40S OVER EAST CENTRAL IL. WEAK LOW PRESSURE AROUND 1015 MB MOVES INTO THE NORTHERN GREAT LAKES BY DAWN THU AND BRINGS A WEAK COLD FRONT INTO CENTRAL IL WHILE ANOTHER FAIRLY STRONG SHORT WAVE/TROF DIGS INTO LAKE MI. THIS TO KEEP BRUNT OF MIXED LIGHT PRECIPITATION NORTH OF CENTRAL IL WITH JUST SLIGHT CHANCES BETWEEN 10 PM AND 4 AM NORTH OF PEORIA. LOWS IN THE MID TO UPPER 30S AGAIN TONIGHT. 1027 MB HIGH PRESSURE BUILDS INTO THE MID MS VALLEY BY SUNSET THU BRINGING MORE SUNSHINE AND HIGHS IN THE MID TO UPPER 50S. LOWS THU NIGHT IN THE UPPER 30S TO NEAR 40F WITH COOLEST READINGS IN EAST CENTRAL IL WHERE MID 30S POSSIBLE. WEATHER SYSTEM EJECTS EAST FROM THE SOUTHERN PLAINS INTO THE TN VALLEY FRI/SAT AND KEEPS THE BRUNT OF ITS SHOWERS SOUTH OF CENTRAL IL. GFS HAS TRENDED FURTHER SOUTH WITH THE QPF FIELDS AND MORE CONFIDENCE OF A DRY FORECAST ON FRIDAY WITH HIGHS IN THE LOWER 60S. HAVE 20-30% CHANCE OF SHOWERS FROM I-70 SOUTH FRIDAY NIGHT AND SAT WITH HIGHEST POPS IN SE IL WITH THUNDER CHANCES STAYING SOUTH OF I-64. HIGHS SAT IN THE MID 60S. LONG TERM...SATURDAY NIGHT THROUGH TUESDAY NIGHT GENERALLY DRY AND MILDER WEATHER EXPECTED SUNDAY AND MONDAY AS SYSTEM EXITS EAST OF IL SUNDAY...WITH HIGHS AROUND 70F SUNDAY AND MID 70S MONDAY. GFS BRINGS PATCHES OF LIGHT QPF INTO IL SUNDAY BUT THINK THIS WILL BE MORE TO OUR SE AS UPPER LEVEL RIDGE BUILDING INTO IL. AN UPPER LEVEL TROF DIGGING INTO THE NORTHERN PLAINS TUE TO PUSH A FRONTAL BOUNDARY SE INTO IA TUE WITH GFS QUICKER WITH COLD FRONT THAN ECMWF. WILL GO WITH ALLBLEND SLIGHT CHANCE POPS OF SHOWERS AND THUNDERSTORMS TUE AND TUE NIGHT. STILL IN THE 70S FOR HIGHS TUE WITH CENTRAL/SE IL AHEAD OF THE COLD FRONT. 07 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
419 PM CDT WED APR 24 2013 .SHORT TERM.../TONIGHT /... ISSUED AT 419 PM CDT WED APR 24 2013 FORECAST CONCERN FOR LATE AFTERNOON AND TONIGHT WILL REVOLVE AROUND PRECIPITATION CHANCES. APPROACHING COLD FRONT WITH STRONG PV ANOMALY...CURRENTLY LEADING TO PRECIPITATION IN SOUTH DAKOTA...WILL SPREAD SE INTO IOWA THIS EVENING. SYSTEM WILL BE QUICK MOVING...AND ANTICIPATE BAND OF SHOWERS TO SWEEP QUICKLY ACROSS THE AREA...SIMILAR TO HRRR TIMING/TREND. WITH SKIES REMAINING CLEAR ACROSS CENTRAL IOWA...NO CU FIELD NOTED...AND HIGH DEW POINT DEPRESSIONS...DO NOT ANTICIPATE DEVELOPMENT AHEAD OF LINE. HOWEVER...SOME MU CAPE WILL LEAD TO ISOLATED THUNDER NEAR FRONT. PRECIPITATION ENDS QUICKLY BEHIND FROPA WITH SUBSIDENCE. HAVE KEPT TEMPERATURES COOLER ACROSS THE NORTH ESPECIALLY...DROPPING OFF QUICKLY BEHIND FROPA...MAY SEE SOME LIGHT RN/SN MIX ACROSS THE NORTH AFTER MIDNIGHT WITH ANY LINGERING PRECIPITATION. .LONG TERM.../THURSDAY THROUGH WEDNESDAY/... ISSUED AT 419 PM CDT WED APR 24 2013 A FAIRLY QUIET...AND MUCH...MUCH WARMER WEATHER PATTERN IS SETTING UP ACROSS THE MIDWEST FOR THE NEXT COUPLE OF DAYS. UNDER THE INFLUENCE OF HIGH PRESSURE...THURSDAY AFTERNOON LOOKS TO BE VERY SIMILAR TO WEDNESDAY...JUST A FEW DEGREES WARMER AND A FEW MORE CLOUDS. HEADING INTO FRIDAY...A NOTABLE THERMAL RIDGE WILL BEGIN TO BUILD ALL THE WAY UP OVER THE DAKOTAS AND INTO CANADA. 850MB TEMPERATURES LOOK TO MAKE IT UP TO AROUND 8C...SETTING UP THE POTENTIAL FOR SOME OF THE WARMEST TEMPERATURES THUS FAR OF 2013 TO BE ADVECTED INTO THE CWA...WHEN THE THERMAL RIDGE SHIFTS EASTWARD BEGINNING SATURDAY. STICKING TO FRIDAY...A WEAK SURFACE TROUGH WILL PUSH THROUGH THE MIDWEST. THE GFS AND NAM BOTH HINT AT CAPE VALUES MAKING IT TO AROUND 300 J/KG...BUT WINDS ALOFT ARE QUITE WEAK...AND THE BOUNDARY ITSELF IS FAIRLY WEAK...SO NOT MUCH PRESENT IN TERMS OF FOCUSING MECHANISMS TO GENERATE ANY CONFIDENCE IN THUNDERSTORM DEVELOPMENT. SATURDAY AND SUNDAY...BOTH DAYS SHOULD BE SIMILAR WEATHER WISE AS THE AFOREMENTIONED THERMAL RIDGE SHIFTS EASTWARD. 850 MB TEMPS WILL GO FROM AROUND 8C IN CENTRAL IOWA...TO AROUND 10C ON SATURDAY...TO AROUND 14C ON SUNDAY. LOTS OF DRY AIR ALOFT WILL SUPPORT MAINLY SUNNY SKIES ON BOTH SATURDAY AND SUNDAY. THE WEATHER PATTERN CHANGES AS WE HEAD INTO MONDAY AND TUESDAY. WE WILL BE WATCHING FOR THE POTENTIAL FOR AFTERNOON THUNDERSTORMS ON BOTH DAYS. AS OF NOW...TUESDAY LOOKS LIKE THE BETTER OF THE TWO DAYS FOR THUNDERSTORM DEVELOPMENT. AS A SIZABLE AREA OF LOW PRESSURE SETS UP TO MOVE THROUGH THE DAKOTAS...MONDAY FEATURES A WARM FRONT PASSING THROUGH IOWA TOWARDS WISCONSIN. THERE IS SOME INSTABILITY EXPECTED AS WE WILL CERTAINLY BE UNDER THE WAA ADVECTION OF THE THERMAL RIDGE...BUT AS OF NOW...IT APPEARS THE CAP WILL BE DIFFICULT TO BREAK. FOR TUESDAY INTO WEDNESDAY...A COLD FRONT IS PROGGED TO PASS THROUGH IOWA. THE GFS SEEMS TO BE A BIT FAST VERSUS THE REST OF THE MODELS...SO ARE TRENDING THE PASSING OF THE FROPA BACK INTO WEDNESDAY. && .AVIATION...24/18Z ISSUED AT 1145 AM CDT WED APR 24 2013 CEILINGS WILL REMAIN PRIMARILY VFR THROUGH PERIOD...THOUGH APPROACHING LOW PRESSURE TROUGH WILL BRING INCREASING CLOUDS. THROUGHOUT THE AFTERNOON WILL SEE GOOD MIXING AND STRONG AND GUSTY WINDS...WINDS WILL REMAIN STRONG THROUGH PERIOD. WILL SEE PRECIPITATION CHANCES ACROSS NORTHERN SITES...KFOD/KMCW/KALO WITH THROUGH. HAVE PUSHED BACK ONSET OF PRECIPITATION A BIT. IN ADDITION...COULD SEE MVFR CEILINGS OR LOWER AT TIMES WITH -RA. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...AWB LONG TERM...KOTENBERG AVIATION...AWB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
704 PM MDT THU APR 25 2013 .UPDATE... ISSUED AT 701 PM MDT THU APR 25 2013 HAVE ALLOWED THE RED FLAG WARNING TO EXPIRE DUE TO INCREASING RH AND DECREASING WINDS. INCREASED PRECIP. CHANCES OVERNIGHT FOR THE SOUTHEAST PARTS OF THE AREA. MODELS AGREE THE BEST MOISTURE AND LIFT WILL BE OVER THOSE LOCATIONS DURING THE OVERNIGHT HOURS. OTHERWISE CURRENT FORECAST LOOKS TO BE IN VERY GOOD SHAPE. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 230 PM MDT THU APR 25 2013 EARLY AFTERNOON WV IMAGERY AND RUC ANALYSIS SHOW CLOSED LOW H5/H7 LOW OVER ARIZONA...WITH ENERGY AHEAD OF THIS FEATURE SPREADING NORTH INTO WESTERN KS/EASTERN COLORADO. AT THE SURFACE A STRONG SURFACE GRADIENT AS DEVELOPED IN RESPONSE TO SURFACE LOW DEEPENING OVER SOUTH CENTRAL COLORADO. WINDS GUSTS HAVE BEEN REPORTED THIS AFTERNOON IN THE 45-50 MPH RANGE...AND RH VALUES HAVE DROPPED TO 15-17 PERCENT OVER EASTERN PARTS OF THE CWA. CLOUD COVER COULD EVENTUALLY LIMIT MIXING...HOWEVER WITH PEAK HEATING UNDERWAY I AM COMFORTABLE KEEPING WIND ADVISORY AND RED FLAG WARNING IN PLACE WITH AFTERNOON UPDATE. CLOSED LOW OVER DESERT SW WILL EJECT OVER WESTERN KS TONIGHT INTO EASTERN KS FRIDAY. WHILE H5 CENTER BECOMES MORE OF AN OPEN WAVE...GUIDANCE IS INDICATING H7 CENTER REMAINING CLOSED AS IT PASSES OVER KS. MODELS SHOW MID LEVEL FRONTOGENETICAL FORCING OVERSPREADING OUR CWA THIS EVENING WITH POSSIBLE BAND FORMATION LATE TONIGHT ON NW SIDE OF H7 LOW...POSSIBLY RESULTING IN BETTER RAIN COVERAGE AND HIGHER RAIN TOTALS. THERE IS MINIMAL MU CAPE GENERALLY LESS THAN 100 J/KG...HOWEVER GFS/NAM BOTH SHOW NEGATIVE THETA E LAPSE RATES IN H8-H7 LAYER ASSOCIATED WITH MAIN AREA OF SHOWERS SO I COULDNT RULE OUT A FEW WEAK THUNDERSTORMS WITH THIS ACTIVITY. HAVE KEPT 50 POPS IN THE SOUTHEAST WHERE BETTER FORCING IS ADVERTISED...WITH RAIN COMING TO AN END FOR MOSTLY LOCATIONS FRIDAY MORNING. I KEPT SLIGHT CHANCE POPS LINGERING IN THE EASTERN PART OF CWA TO ACCOUNT FOR POSSIBLE RAIN BAND LINGERING OVER NORTH CENTRAL KS. THERE WILL BE A WEAK COLD FRONT PASSING THROUGH THE CWA BY FRIDAY MORNING...HOWEVER WITH CLEARING SKIES AND WAA IN THE AFTERNOON I STILL EXPECT HIGHS FRIDAY TO REACH UPPER 60S/NEAR 70 IN THE WEST (BASED ON MIXING THE LAST FEW DAYS). WARMING COULD BE LIMITED IN THE EAST DUE TO CLOUDS/PRECIP POSSIBLY LINGERING. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 230 PM MDT THU APR 25 2013 FRIDAY NIGHT-SUNDAY...DRY WEATHER EXPECTED. WILL NEED TO WATCH THE FAR EASTERN PORTIONS OF THE AREA FOR THUNDERSTORMS SATURDAY AFTERNOON AS A SFC TROUGH MOVES THROUGH. THERE IS SOME WEAK CONVERGENCE AND INSTABILITY ALONG THE WIND SHIFT WITH THIS FEATURE...QUESTION RIGHT NOW IS HOW MUCH MOISTURE WILL BE AVAILABLE. ANY THREAT FOR PRECIP SATURDAY AFTERNOON QUICKLY DECREASES SATURDAY NIGHT AS THE SFC TROUGH MOVES EAST AND OUT OF THE AREA. FOR SUNDAY GENERALLY SUNNY...MAY SEE SOME CIRRUS MOVE DOWN FROM THE NORTH. LOWS FRIDAY NIGHT MID 30S TO LOW 40S WITH UPPER 30S TO MID 40S SATURDAY NIGHT. HIGHS SATURDAY IN THE 70S WITH MID 70S (WEST) TO MID 80S (EAST) SUNDAY. SUNDAY NIGHT-MONDAY...COLD FRONT BRIEFLY PUSHES SOUTHWEST ACROSS THE AREA SUNDAY NIGHT BEFORE RETREATING OUT OF THE AREA. NEAR OR SLIGHTLY COOLER READINGS COMPARED TO SUNDAY EXPECTED ACROSS THE NORTHEAST AND EAST WHERE PROXIMITY TO DEPARTING HIGH WILL BE FELT MOST. TO THE WEST SIMILAR TO SLIGHTLY WARMER READINGS COMPARED TO SUNDAY. LOWS MID 40S TO LOW 50S (WEST TO EAST) WITH HIGHS 75 TO 80 MONDAY. MONDAY NIGHT-TUESDAY NIGHT...SFC TROUGH ACROSS THE AREA MONDAY NIGHT WITH COLD FRONT MOVING THROUGH FROM THE NORTH TUESDAY. BREEZY NORTH TO NORTHEAST WINDS TUESDAY NIGHT BEHIND THE FRONT. LOWS MONDAY NIGHT MID 40S TO MID 50S (WEST TO EAST) WITH MID 30S TO MID 40S (WEST TO EAST) TUESDAY NIGHT. HIGHS TUESDAY LOW 70S TO AROUND 80 (NORTH TO SOUTH). SHOWERS AND A FEW THUNDERSTORMS POSSIBLE ACROSS THE EAST TUESDAY AFTERNOON AHEAD OF THE FRONT. POST FRONTAL STABLE AIR MOVES IN TUESDAY NIGHT. REMOVED MENTION OF THUNDERSTORMS BUT STILL HAVE A CHANCE OF LIGHT RAIN. WEDNESDAY-WEDNESDAY NIGHT...BREEZY NORTH WINDS TO CONTINUE ACROSS THE EASTERN HALF OF THE AREA THROUGH THE DAY. SFC HIGH REMAINS OVER THE AREA WEDNESDAY NIGHT ALLOWING FOR NEAR TO SLIGHTLY BELOW NORMAL LOW TEMPERATURES. HIGHS IN THE MID TO UPPER 50S WITH LOWS MID TO UPPER 30S. LOW CHANCES FOR SOME LIGHT RAIN OR RAIN SHOWERS DURING THE DAY DECREASING DURING THE NIGHT. THURSDAY...WARMER TEMPERATURES EXPECTED TO RETURN TO THE AREA AS UPPER RIDGING SLOWLY MOVES IN FROM THE WEST. HIGHS MID 50S TO LOW 60S. CONTINUED LOW CHANCE FOR SOME LIGHT RAIN ACROSS THE AREA. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 555 PM MDT THU APR 25 2013 VFR CONDITIONS ARE FORECAST FOR THE 0Z TAFS. THE ERRONEOUS MVFR CEILINGS APPEAR TO BE GOING AWAY AS WINDS DECLINE AND THE AMOUNT OF DUST IN THE AIR SUBSIDES. AM ANTICIPATING THE WINDS TO QUICKLY DECLINE OVER THE NEXT COUPLE OF HOURS AS TEMPERATURES COOL. DURING THE EVENING RAIN SHOWERS WILL MOVE INTO THE AREA FROM THE WEST. LATEST MODEL DATA CONTINUES TO SUGGEST KGLD WILL BE ON THE NORTHERN EDGE OF THE ACTIVITY...SO WILL CONTINUE WITH THE VCSH MENTION. WILL AMMEND THE TAF IF NEED BE...BUT DO NOT FORESEE ANY REDUCTIONS IN VIS/CEILING IF SHOWERS DO MOVE OVER KGLD. THERE MAY BE AN ISOLATED THUNDERSTORM OR TWO...BUT AM NOT CONFIDENT ENOUGH THEY WILL MOVE OVER KGLD TO PLACE A MENTION IN THE TAF. OVERNIGHT WINDS WILL BECOME LIGHT AND VARIABLE AHEAD OF A COLD FRONT THAT WILL MOVE INTO THE AREA DURING THE OVERNIGHT/EARLY MORNING HOURS. THE WIND SHIFT WILL NOT MOVE OVER THE TAF SITES UNTIL THE MID TO LATE MORNING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JTL SHORT TERM...DR LONG TERM...99 AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
605 PM MDT THU APR 25 2013 .UPDATE.. ISSUED AT 600 PM MDT THU APR 25 2013 HAVE ALLOWED THE WIND ADVISORY TO EXPIRE. CURRENT OBSERVATIONS INDICATE GUSTS AROUND 35 MPH CAN BE EXPECTED FOR THE NEXT HOUR OR SO. .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 230 PM MDT THU APR 25 2013 EARLY AFTERNOON WV IMAGERY AND RUC ANALYSIS SHOW CLOSED LOW H5/H7 LOW OVER ARIZONA...WITH ENERGY AHEAD OF THIS FEATURE SPREADING NORTH INTO WESTERN KS/EASTERN COLORADO. AT THE SURFACE A STRONG SURFACE GRADIENT AS DEVELOPED IN RESPONSE TO SURFACE LOW DEEPENING OVER SOUTH CENTRAL COLORADO. WINDS GUSTS HAVE BEEN REPORTED THIS AFTERNOON IN THE 45-50 MPH RANGE...AND RH VALUES HAVE DROPPED TO 15-17 PERCENT OVER EASTERN PARTS OF THE CWA. CLOUD COVER COULD EVENTUALLY LIMIT MIXING...HOWEVER WITH PEAK HEATING UNDERWAY I AM COMFORTABLE KEEPING WIND ADVISORY AND RED FLAG WARNING IN PLACE WITH AFTERNOON UPDATE. CLOSED LOW OVER DESERT SW WILL EJECT OVER WESTERN KS TONIGHT INTO EASTERN KS FRIDAY. WHILE H5 CENTER BECOMES MORE OF AN OPEN WAVE...GUIDANCE IS INDICATING H7 CENTER REMAINING CLOSED AS IT PASSES OVER KS. MODELS SHOW MID LEVEL FRONTOGENETICAL FORCING OVERSPREADING OUR CWA THIS EVENING WITH POSSIBLE BAND FORMATION LATE TONIGHT ON NW SIDE OF H7 LOW...POSSIBLY RESULTING IN BETTER RAIN COVERAGE AND HIGHER RAIN TOTALS. THERE IS MINIMAL MU CAPE GENERALLY LESS THAN 100 J/KG...HOWEVER GFS/NAM BOTH SHOW NEGATIVE THETA E LAPSE RATES IN H8-H7 LAYER ASSOCIATED WITH MAIN AREA OF SHOWERS SO I COULDNT RULE OUT A FEW WEAK THUNDERSTORMS WITH THIS ACTIVITY. HAVE KEPT 50 POPS IN THE SOUTHEAST WHERE BETTER FORCING IS ADVERTISED...WITH RAIN COMING TO AN END FOR MOSTLY LOCATIONS FRIDAY MORNING. I KEPT SLIGHT CHANCE POPS LINGERING IN THE EASTERN PART OF CWA TO ACCOUNT FOR POSSIBLE RAIN BAND LINGERING OVER NORTH CENTRAL KS. THERE WILL BE A WEAK COLD FRONT PASSING THROUGH THE CWA BY FRIDAY MORNING...HOWEVER WITH CLEARING SKIES AND WAA IN THE AFTERNOON I STILL EXPECT HIGHS FRIDAY TO REACH UPPER 60S/NEAR 70 IN THE WEST (BASED ON MIXING THE LAST FEW DAYS). WARMING COULD BE LIMITED IN THE EAST DUE TO CLOUDS/PRECIP POSSIBLY LINGERING. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 230 PM MDT THU APR 25 2013 FRIDAY NIGHT-SUNDAY...DRY WEATHER EXPECTED. WILL NEED TO WATCH THE FAR EASTERN PORTIONS OF THE AREA FOR THUNDERSTORMS SATURDAY AFTERNOON AS A SFC TROUGH MOVES THROUGH. THERE IS SOME WEAK CONVERGENCE AND INSTABILITY ALONG THE WIND SHIFT WITH THIS FEATURE...QUESTION RIGHT NOW IS HOW MUCH MOISTURE WILL BE AVAILABLE. ANY THREAT FOR PRECIP SATURDAY AFTERNOON QUICKLY DECREASES SATURDAY NIGHT AS THE SFC TROUGH MOVES EAST AND OUT OF THE AREA. FOR SUNDAY GENERALLY SUNNY...MAY SEE SOME CIRRUS MOVE DOWN FROM THE NORTH. LOWS FRIDAY NIGHT MID 30S TO LOW 40S WITH UPPER 30S TO MID 40S SATURDAY NIGHT. HIGHS SATURDAY IN THE 70S WITH MID 70S (WEST) TO MID 80S (EAST) SUNDAY. SUNDAY NIGHT-MONDAY...COLD FRONT BRIEFLY PUSHES SOUTHWEST ACROSS THE AREA SUNDAY NIGHT BEFORE RETREATING OUT OF THE AREA. NEAR OR SLIGHTLY COOLER READINGS COMPARED TO SUNDAY EXPECTED ACROSS THE NORTHEAST AND EAST WHERE PROXIMITY TO DEPARTING HIGH WILL BE FELT MOST. TO THE WEST SIMILAR TO SLIGHTLY WARMER READINGS COMPARED TO SUNDAY. LOWS MID 40S TO LOW 50S (WEST TO EAST) WITH HIGHS 75 TO 80 MONDAY. MONDAY NIGHT-TUESDAY NIGHT...SFC TROUGH ACROSS THE AREA MONDAY NIGHT WITH COLD FRONT MOVING THROUGH FROM THE NORTH TUESDAY. BREEZY NORTH TO NORTHEAST WINDS TUESDAY NIGHT BEHIND THE FRONT. LOWS MONDAY NIGHT MID 40S TO MID 50S (WEST TO EAST) WITH MID 30S TO MID 40S (WEST TO EAST) TUESDAY NIGHT. HIGHS TUESDAY LOW 70S TO AROUND 80 (NORTH TO SOUTH). SHOWERS AND A FEW THUNDERSTORMS POSSIBLE ACROSS THE EAST TUESDAY AFTERNOON AHEAD OF THE FRONT. POST FRONTAL STABLE AIR MOVES IN TUESDAY NIGHT. REMOVED MENTION OF THUNDERSTORMS BUT STILL HAVE A CHANCE OF LIGHT RAIN. WEDNESDAY-WEDNESDAY NIGHT...BREEZY NORTH WINDS TO CONTINUE ACROSS THE EASTERN HALF OF THE AREA THROUGH THE DAY. SFC HIGH REMAINS OVER THE AREA WEDNESDAY NIGHT ALLOWING FOR NEAR TO SLIGHTLY BELOW NORMAL LOW TEMPERATURES. HIGHS IN THE MID TO UPPER 50S WITH LOWS MID TO UPPER 30S. LOW CHANCES FOR SOME LIGHT RAIN OR RAIN SHOWERS DURING THE DAY DECREASING DURING THE NIGHT. THURSDAY...WARMER TEMPERATURES EXPECTED TO RETURN TO THE AREA AS UPPER RIDGING SLOWLY MOVES IN FROM THE WEST. HIGHS MID 50S TO LOW 60S. CONTINUED LOW CHANCE FOR SOME LIGHT RAIN ACROSS THE AREA. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 555 PM MDT THU APR 25 2013 VFR CONDITIONS ARE FORECAST FOR THE 0Z TAFS. THE ERRONEOUS MVFR CEILINGS APPEAR TO BE GOING AWAY AS WINDS DECLINE AND THE AMOUNT OF DUST IN THE AIR SUBSIDES. AM ANTICIPATING THE WINDS TO QUICKLY DECLINE OVER THE NEXT COUPLE OF HOURS AS TEMPERATURES COOL. DURING THE EVENING RAIN SHOWERS WILL MOVE INTO THE AREA FROM THE WEST. LATEST MODEL DATA CONTINUES TO SUGGEST KGLD WILL BE ON THE NORTHERN EDGE OF THE ACTIVITY...SO WILL CONTINUE WITH THE VCSH MENTION. WILL AMMEND THE TAF IF NEED BE...BUT DO NOT FORESEE ANY REDUCTIONS IN VIS/CEILING IF SHOWERS DO MOVE OVER KGLD. THERE MAY BE AN ISOLATED THUNDERSTORM OR TWO...BUT AM NOT CONFIDENT ENOUGH THEY WILL MOVE OVER KGLD TO PLACE A MENTION IN THE TAF. OVERNIGHT WINDS WILL BECOME LIGHT AND VARIABLE AHEAD OF A COLD FRONT THAT WILL MOVE INTO THE AREA DURING THE OVERNIGHT/EARLY MORNING HOURS. THE WIND SHIFT WILL NOT MOVE OVER THE TAF SITES UNTIL THE MID TO LATE MORNING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...RED FLAG WARNING UNTIL 7 PM MDT /8 PM CDT/ THIS EVENING FOR KSZ002>004-014>016-027>029-041-042. CO...NONE. NE...RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR NEZ080-081. && $$ SHORT TERM...DR LONG TERM...99 AVIATION...JTL UPDATE...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
347 PM MDT WED APR 24 2013 .UPDATE... ISSUED AT 340 PM MDT WED APR 24 2013 SURFACE OBSERVATIONS INDICATE A NARROW CORRIDOR OF LOWER DEW POINTS FROM AROUND IMPERIAL SOUTHEAST TO HILL CITY. WITH NORTHWEST WINDS GUSTING TO 30 MPH AS THE SURFACE TROUGH MOVES THROUGH AND RELATIVE HUMIDITIES FALLING TO AROUND 15 PERCENT...AM THINKING THERE WILL BE BRIEF PERIODS OF CRITICAL FIRE WEATHER CONDITIONS THIS AFTERNOON. BEHIND THE SURFACE TROUGH OVER SOUTHWEST NEBRASKA TEMPERATURES APPEAR TO BE COOLING SOME. THE INCREASING CLOUD COVER MAY ALSO HELP THE WIND GUSTS TO DECREASE BELOW 30 MPH. WITH ALL THIS IN MIND AND THAT CRITICAL FIRE WEATHER CONDITIONS ARE JUST BEING REALIZED AT MID AFTERNOON...AM NOT CONFIDENT ENOUGH TO ISSUE A FIRE WEATHER HIGHLITE FOR THE NORTHEAST PART OF THE AREA. HOWEVER...SINCE THIS AREA DID NOT RECEIVE MUCH SNOW FROM THE RECENT STORM...THE FUELS MAY BE DRY ENOUGH FOR CRITICAL FIRE WEATHER CONDITIONS SO HAVE ISSUED AN SPS MENTIONING THE BRIEF THREAT. && .SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY) ISSUED AT 101 PM MDT WED APR 24 2013 EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW BROAD TROUGH CENTERED OVER GREAT LAKES REGION WITH W/NW FLOW ACROSS THE NORTHERN AND CENTRAL PLAINS. A SHORTWAVE TROUGH IS CURRENTLY OVER EASTERN WYOMING EXTENDING ACROSS THE GREAT BASIN. THIS THIS FEATURE IS PROGGED TO SPLIT WITH THE MAIN ENERGY ALOFT REMAINING NORTH OF OUR CWA. VERY STEEP LOW LEVEL LAPSE RATES AND WEAK FORCING AHEAD OF THIS FEATURE HAVE PRODUCED HIGH BASED VIRGA/LIGHT SHOWERS OVER PARTS OF NORTH CENTRAL NEBRASKA WITH A CU FIELD EXTENDING SOUTH WHERE FURTHER DEVELOPMENT IS POSSIBLE. WHILE I COULDNT RULE OUT A FEW SPRINKLES OR VIRGA THIS AFTERNOON/EARLY EVENING CONFIDENCE IS LOW IN MEASURABLE. SUBSIDENCE SHOULD OVERSPREAD THE REGION OVERNIGHT...WITH CLEARING SKIES AND LIGHT AND VARIABLE WINDS. LEE TROUGH BUILDING OVER SE COLORADO AND WESTERLY FLOW ALOFT WILL SUPPORT MODERATING AIR MASS OVER OUR CWA BEGINNING TONIGHT. OVERNIGHT LOWS (WHILE BELOW NORMAL) SHOULD BE WARMER THAN THE LAST FEW NIGHTS WITH VALUES IN THE UPPER 20S/LOW 30S (COLDEST IN PROXIMITY TO LINGERING SNOW PACK). TEMPS ALOFT CONTINUE TO MODERATE THROUGH THE DAY THURSDAY. ITS HARD TO SAY IF WE WILL STILL HAVE ANY EFFECT FROM SNOW PACK OR NOT (WHAT IS LEFT AFTER MELTING THIS AFTERNOON). FOR NOW I STAYED IN LINE WITH PREVIOUS FORECASTS WITH HIGHS IN THE LOW 60S WHERE SNOW PACK IS AND UPPER 60S/LOW 70S ELSEWHERE. A SHORTWAVE TROUGH IS PROGGED TO MOVE INTO THE SOUTHERN ROCKIES THURSDAY AFTERNOON...WITH CLOUDS INCREASING FROM THE WEST/SOUTHWEST. A FEW HIGH BASED SHOWERS/ISOLATED THUNDERSTORMS MAY DEVELOP OVER THE HIGHER TERRAIN OF COLORADO...WHICH COULD SNEAK INTO WESTERN PORTIONS OF OUR CWA DURING THE LATE AFTERNOON HOURS. CONFIDENCE IS GENERALLY LOW ON MEASURABLE...HOWEVER WITH STEEP LAPSE RATES AND NAM/SREF SHOWING LIGHT QPF I ADDED SLIGHT CHANCE POPS TO WESTERN KIT CARSON/CHEYENNE COUNTIES IN COLORADO IN THE 21-00Z TIME FRAME. OTHER CONCERN FOR THURSDAY AFTERNOON WILL BE WINDY CONDITIONS WITH TIGHT UNIDIRECTIONAL GRADIENT OUT OF THE S/SW TO ABOUT H7. THERE IS SOME SUPPORT OF NEAR ADVISORY CRITERIA DURING THE AFTERNOON HOURS...HOWEVER DUE TO LOW CONFIDENCE IN DURATION...AND MARGINAL CONDITIONS I DECIDED AGAINST ISSUANCE. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 115 PM MDT WED APR 24 2013 THURSDAY NIGHT-SATURDAY...UPPER LOW FORECAST TO BE OVER NORTHEAST ARIZONA AROUND 00Z FRIDAY EXPECTED TO MOVE EAST/NORTHEAST INTO SOUTHEAST COLORADO BY 12Z FRIDAY THEN SOUTHEAST KANSAS BY 06Z SATURDAY AND EASTERN ILLINOIS AT 00Z SUNDAY. SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE AS THIS SYSTEM MOVES ACROSS OUR PART OF THE COUNTRY THURSDAY NIGHT...OTHERWISE DRY THROUGH THE PERIOD. SATURDAY NIGHT-MONDAY...DRY WITH LITTLE IN THE WAY OF CLOUDINESS. ABOVE NORMAL TEMPERATURES WITH LOWS IN THE 40S SATURDAY NIGHT WARMING INTO THE LOW 40S WEST TO LOW 50S EAST SUNDAY NIGHT. HIGHS SUNDAY MID 70S TO AROUND 80 WEST...LOW 80S EAST. A TAD COOLER MONDAY WITH MID 70S TO AROUND 80 ACROSS THE AREA...COOLEST WEST. PAST 5 DAYS OF 850 TEMPERATURES WOULD SUPPORT SLIGHTLY WARMER READINGS THEN CURRENTLY ADVERTISED. MONDAY NIGHT-WEDNESDAY...PRECIPITATION CHANCES INCREASE A BIT AS AN UPPER TROUGH AND COLD FRONT MOVE ACROSS THE AREA. HIGH TEMPERATURES TUESDAY UPPER 60S TO LOW 70S WITH 55-60 WEDNESDAY. LOWS MONDAY NIGHT MID 40S TO MID 50S (WEST TO EAST)...LOW TO MID 40S (WEST TO EAST) TUESDAY NIGHT. MAY SEE SOME BREEZY NORTH TO NORTHEAST WINDS TUESDAY NIGHT THROUGH WEDNESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1121 AM MDT WED APR 24 2013 VFR CONDITIONS EXPECTED THROUGH TAF PERIOD AT BOTH KGLD AND KMCK TERMINALS. NW WINDS GUSTING TO 25KT ARE EXPECTED AT BOTH TERMINALS THIS AFTERNOON AS A DISTURBANCE MOVES ACROSS CENTRAL NEBRASKA. THESE WINDS SHOULD DIMINISH AROUND SUNSET WITH LIGHT AND VARIABLE WINDS OVERNIGHT. A SURFACE TROUGH WILL DEEPEN OVER SE COLORADO THURSDAY WITH GRADIENT INCREASING OVER BOTH TERMINALS. RESULT SHOULD BE A SHIFT AND INCREASE IN WINDS TO THE SOUTH-SOUTHWEST AROUND SUNRISE...WITH GUSTS AROUND 25KT AT KGLD BY MID MORNING. STRONGER WINDS ARE LIKELY THURSDAY AFTERNOON AT BOTH TERMINALS...WHICH IS OUTSIDE THE CURRENT TAF PERIOD. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JTL SHORT TERM...DR LONG TERM...99 AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
120 PM MDT WED APR 24 2013 .SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY) ISSUED AT 101 PM MDT WED APR 24 2013 EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW BROAD TROUGH CENTERED OVER GREAT LAKES REGION WITH W/NW FLOW ACROSS THE NORTHERN AND CENTRAL PLAINS. A SHORTWAVE TROUGH IS CURRENTLY OVER EASTERN WYOMING EXTENDING ACROSS THE GREAT BASIN. THIS THIS FEATURE IS PROGGED TO SPLIT WITH THE MAIN ENERGY ALOFT REMAINING NORTH OF OUR CWA. VERY STEEP LOW LEVEL LAPSE RATES AND WEAK FORCING AHEAD OF THIS FEATURE HAVE PRODUCED HIGH BASED VIRGA/LIGHT SHOWERS OVER PARTS OF NORTH CENTRAL NEBRASKA WITH A CU FIELD EXTENDING SOUTH WHERE FURTHER DEVELOPMENT IS POSSIBLE. WHILE I COULDNT RULE OUT A FEW SPRINKLES OR VIRGA THIS AFTERNOON/EARLY EVENING CONFIDENCE IS LOW IN MEASURABLE. SUBSIDENCE SHOULD OVERSPREAD THE REGION OVERNIGHT...WITH CLEARING SKIES AND LIGHT AND VARIABLE WINDS. LEE TROUGH BUILDING OVER SE COLORADO AND WESTERLY FLOW ALOFT WILL SUPPORT MODERATING AIRMASS OVER OUR CWA BEGINNING TONIGHT. OVERNIGHT LOWS (WHILE BELOW NORMAL) SHOULD BE WARMER THAN THE LAST FEW NIGHTS WITH VALUES IN THE UPPER 20S/LOW 30S (COLDEST IN PROXIMITY TO LINGERING SNOW PACK). TEMPS ALOFT CONTINUE TO MODERATE THROUGH THE DAY THURSDAY. ITS HARD TO SAY IF WE WILL STILL HAVE ANY EFFECT FROM SNOW PACK OR NOT (WHAT IS LEFT AFTER MELTING THIS AFTERNOON). FOR NOW I STAYED IN LINE WITH PREVIOUS FORECASTS WITH HIGHS IN THE LOW 60S WHERE SNOW PACK IS AND UPPER 60S/LOW 70S ELSEWHERE. A SHORTWAVE TROUGH IS PROGGED TO MOVE INTO THE SOUTHERN ROCKIES THURSDAY AFTERNOON...WITH CLOUDS INCREASING FROM THE WEST/SOUTHWEST. A FEW HIGH BASED SHOWERS/ISOLATED THUNDERSTORMS MAY DEVELOP OVER THE HIGHER TERRAIN OF COLORADO...WHICH COULD SNEAK INTO WESTERN PORTIONS OF OUR CWA DURING THE LATE AFTERNOON HOURS. CONFIDENCE IS GENERALLY LOW ON MEASURABLE...HOWEVER WITH STEEP LAPSE RATES AND NAM/SREF SHOWING LIGHT QPF I ADDED SLIGHT CHANCE POPS TO WESTERN KIT CARSON/CHEYENNE COUNTIES IN COLORADO IN THE 21-00Z TIME FRAME. OTHER CONCERN FOR THURSDAY AFTERNOON WILL BE WINDY CONDITIONS WITH TIGHT UNIDIRECTIONAL GRADIENT OUT OF THE S/SW TO ABOUT H7. THERE IS SOME SUPPORT OF NEAR ADVISORY CRITERIA DURING THE AFTERNOON HOURS...HOWEVER DUE TO LOW CONFIDENCE IN DURATION...AND MARGINAL CONDITIONS I DECIDED AGAINST ISSUANCE. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 115 PM MDT WED APR 24 2013 THURSDAY NIGHT-SATURDAY...UPPER LOW FORECAST TO BE OVER NORTHEAST ARIZONA AROUND 00Z FRIDAY EXPECTED TO MOVE EAST/NORTHEAST INTO SOUTHEAST COLORADO BY 12Z FRIDAY THEN SOUTHEAST KANSAS BY 06Z SATURDAY AND EASTERN ILLINOIS AT 00Z SUNDAY. SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE AS THIS SYSTEM MOVES ACROSS OUR PART OF THE COUNTRY THURSDAY NIGHT...OTHERWISE DRY THROUGH THE PERIOD. SATURDAY NIGHT-MONDAY...DRY WITH LITTLE IN THE WAY OF CLOUDINESS. ABOVE NORMAL TEMPERATURES WITH LOWS IN THE 40S SATURDAY NIGHT WARMING INTO THE LOW 40S WEST TO LOW 50S EAST SUNDAY NIGHT. HIGHS SUNDAY MID 70S TO AROUND 80 WEST...LOW 80S EAST. A TAD COOLER MONDAY WITH MID 70S TO AROUND 80 ACROSS THE AREA...COOLEST WEST. PAST 5 DAYS OF 850 TEMPERATURES WOULD SUPPORT SLIGHTLY WARMER READINGS THEN CURRENTLY ADVERTISED. MONDAY NIGHT-WEDNESDAY...PRECIPITATION CHANCES INCREASE A BIT AS AN UPPER TROUGH AND COLD FRONT MOVE ACROSS THE AREA. HIGH TEMPERATURES TUESDAY UPPER 60S TO LOW 70S WITH 55-60 WEDNESDAY. LOWS MONDAY NIGHT MID 40S TO MID 50S (WEST TO EAST)...LOW TO MID 40S (WEST TO EAST) TUESDAY NIGHT. MAY SEE SOME BREEZY NORTH TO NORTHEAST WINDS TUESDAY NIGHT THROUGH WEDNESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1121 AM MDT WED APR 24 2013 VFR CONDITIONS EXPECTED THROUGH TAF PERIOD AT BOTH KGLD AND KMCK TERMINALS. NW WINDS GUSTING TO 25KT ARE EXPECTED AT BOTH TERMINALS THIS AFTERNOON AS A DISTURBANCE MOVES ACROSS CENTRAL NEBRASKA. THESE WINDS SHOULD DIMINISH AROUND SUNSET WITH LIGHT AND VARIABLE WINDS OVERNIGHT. A SURFACE TROUGH WILL DEEPEN OVER SE COLORADO THURSDAY WITH GRADIENT INCREASING OVER BOTH TERMINALS. RESULT SHOULD BE A SHIFT AND INCREASE IN WINDS TO THE SOUTH-SOUTHWEST AROUND SUNRISE...WITH GUSTS AROUND 25KT AT KGLD BY MID MORNING. STRONGER WINDS ARE LIKELY THURSDAY AFTERNOON AT BOTH TERMINALS...WHICH IS OUTSIDE THE CURRENT TAF PERIOD. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...99 AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
101 PM MDT WED APR 24 2013 .SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY) ISSUED AT 101 PM MDT WED APR 24 2013 EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW BROAD TROUGH CENTERED OVER GREAT LAKES REGION WITH W/NW FLOW ACROSS THE NORTHERN AND CENTRAL PLAINS. A SHORTWAVE TROUGH IS CURRENTLY OVER EASTERN WYOMING EXTENDING ACROSS THE GREAT BASIN. THIS THIS FEATURE IS PROGGED TO SPLIT WITH THE MAIN ENERGY ALOFT REMAINING NORTH OF OUR CWA. VERY STEEP LOW LEVEL LAPSE RATES AND WEAK FORCING AHEAD OF THIS FEATURE HAVE PRODUCED HIGH BASED VIRGA/LIGHT SHOWERS OVER PARTS OF NORTH CENTRAL NEBRASKA WITH A CU FIELD EXTENDING SOUTH WHERE FURTHER DEVELOPMENT IS POSSIBLE. WHILE I COULDNT RULE OUT A FEW SPRINKLES OR VIRGA THIS AFTERNOON/EARLY EVENING CONFIDENCE IS LOW IN MEASURABLE. SUBSIDENCE SHOULD OVERSPREAD THE REGION OVERNIGHT...WITH CLEARING SKIES AND LIGHT AND VARIABLE WINDS. LEE TROUGH BUILDING OVER SE COLORADO AND WESTERLY FLOW ALOFT WILL SUPPORT MODERATING AIRMASS OVER OUR CWA BEGINNING TONIGHT. OVERNIGHT LOWS (WHILE BELOW NORMAL) SHOULD BE WARMER THAN THE LAST FEW NIGHTS WITH VALUES IN THE UPPER 20S/LOW 30S (COLDEST IN PROXIMITY TO LINGERING SNOW PACK). TEMPS ALOFT CONTINUE TO MODERATE THROUGH THE DAY THURSDAY. ITS HARD TO SAY IF WE WILL STILL HAVE ANY EFFECT FROM SNOW PACK OR NOT (WHAT IS LEFT AFTER MELTING THIS AFTERNOON). FOR NOW I STAYED IN LINE WITH PREVIOUS FORECASTS WITH HIGHS IN THE LOW 60S WHERE SNOW PACK IS AND UPPER 60S/LOW 70S ELSEWHERE. A SHORTWAVE TROUGH IS PROGGED TO MOVE INTO THE SOUTHERN ROCKIES THURSDAY AFTERNOON...WITH CLOUDS INCREASING FROM THE WEST/SOUTHWEST. A FEW HIGH BASED SHOWERS/ISOLATED THUNDERSTORMS MAY DEVELOP OVER THE HIGHER TERRAIN OF COLORADO...WHICH COULD SNEAK INTO WESTERN PORTIONS OF OUR CWA DURING THE LATE AFTERNOON HOURS. CONFIDENCE IS GENERALLY LOW ON MEASURABLE...HOWEVER WITH STEEP LAPSE RATES AND NAM/SREF SHOWING LIGHT QPF I ADDED SLIGHT CHANCE POPS TO WESTERN KIT CARSON/CHEYENNE COUNTIES IN COLORADO IN THE 21-00Z TIME FRAME. OTHER CONCERN FOR THURSDAY AFTERNOON WILL BE WINDY CONDITIONS WITH TIGHT UNIDIRECTIONAL GRADIENT OUT OF THE S/SW TO ABOUT H7. THERE IS SOME SUPPORT OF NEAR ADVISORY CRITERIA DURING THE AFTERNOON HOURS...HOWEVER DUE TO LOW CONFIDENCE IN DURATION...AND MARGINAL CONDITIONS I DECIDED AGAINST ISSUANCE. .LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 235 AM MDT WED APR 24 2013 DRY CONDITIONS AND ABOVE NORMAL TEMPERATURES ARE EXPECTED THIS WEEKEND AS WEAK UPPER LEVEL RIDGING BUILDS INTO THE AREA. A TROUGH OVER THE PACIFIC NORTHWEST WILL PROGRESS EASTWARD BY THE FIRST OF THE WEEK BUT SIGNIFICANT DIFFERENCES EMERGE AMONG GFS ENSEMBLE MEMBERS AND ECMWF BY THEN. DEPENDING ON WHAT HAPPENS WITH THE AFOREMENTIONED TROUGH...ADJUSTMENT IN POP AND WEATHER GRIDS MAY BE NEEDED. GFS IS MORE PROGRESSIVE THAN ECMWF. FOR NOW...DECIDED TO CARRY SLIGHT CHANCE POPS MAINLY IN THE EASTERN HALF OF THE FORECAST AREA ON MONDAY AND TUESDAY WHERE BETTER LOW LEVEL MOISTURE WILL RESIDE. MADE ONLY MINOR ADJUSTMENTS TO CR INIT POP GRIDS TO SHARPEN THE GRADIENT SLIGHTLY FROM WEST TO EAST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1121 AM MDT WED APR 24 2013 VFR CONDITIONS EXPECTED THROUGH TAF PERIOD AT BOTH KGLD AND KMCK TERMINALS. NW WINDS GUSTING TO 25KT ARE EXPECTED AT BOTH TERMINALS THIS AFTERNOON AS A DISTURBANCE MOVES ACROSS CENTRAL NEBRASKA. THESE WINDS SHOULD DIMINISH AROUND SUNSET WITH LIGHT AND VARIABLE WINDS OVERNIGHT. A SURFACE TROUGH WILL DEEPEN OVER SE COLORADO THURSDAY WITH GRADIENT INCREASING OVER BOTH TERMINALS. RESULT SHOULD BE A SHIFT AND INCREASE IN WINDS TO THE SOUTH-SOUTHWEST AROUND SUNRISE...WITH GUSTS AROUND 25KT AT KGLD BY MID MORNING. STRONGER WINDS ARE LIKELY THURSDAY AFTERNOON AT BOTH TERMINALS...WHICH IS OUTSIDE THE CURRENT TAF PERIOD. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...BRB AVIATION...DR
AREA FORECAST DISCUSSION
NWS PADUCAH KY
653 AM CDT WED APR 24 2013 .UPDATE... ISSUED AT 652 AM CDT WED APR 24 2013 THE AVIATION SECTION HAS BEEN UPDATED FOR THE 12Z TAF ISSUANCE. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 336 AM CDT WED APR 24 2013 BOTH THE SURFACE COLD FRONT AND THE MAIN POST-FRONTAL BAND OF SHOWERS AND THUNDERSTORMS ARE TAKING THEIR SWEET TIME TONIGHT. AS OF 08Z...THE COLD FRONT WAS LOCATED FROM NEAR FT CAMPBELL TO NEAR GREENVILLE KENTUCKY...AND THE BAND OF CONVECTION WAS LOCATED ALONG AND NORTHWEST OF A LINE FROM DONIPHAN MISSOURI TO MARION AND MT CARMEL ILLINOIS. WATER VAPOR IMAGERY SHOWS THE MAIN MID/UPPER LEVEL IMPULSE PIVOTING EASTWARD OVER THE SOUTHERN/CENTRAL PLAINS. THIS SHOULD HELP TO GIVE THE MAIN BAND A GOOD PUSH...AND MAY CAUSE IT TO PIVOT TO MORE OF A SOUTH SOUTHWEST TO NORTH NORTHEAST ORIENTATION THROUGH SUNRISE. USED THE LATEST RAP AS A GUIDE FOR HOURLY POP GRIDS THROUGH THE END OF THE EVENT. SHOULD SEE THE MAIN BAND PUSH SOUTHWARD TOWARD THE OHIO RIVER THROUGH SUNRISE...AND THEN GRADUALLY COME TO AN END FROM WEST TO EAST THROUGH THE MORNING. SCATTERED SHOWERS AND POSSIBLY A FEW THUNDERSTORMS WILL CONTINUE IN THE VICINITY OF THE FRONT IN THE SOUTHERN PENNYRILE THROUGH DAYBREAK...BUT THE MAIN BAND MAY NOT QUITE GET DOWN THAT FAR SOUTHEAST BEFORE BEING FORCED EAST OF THE AREA. THE SURFACE HIGH WILL PUSH EASTWARD ACROSS THE AREA THROUGH THE DAY WHICH SHOULD LEAD TO A NICE CLEARING TREND AND DIMINISHING WINDS. WINDS WILL GO NEARLY CALM THIS EVENING AS THE SURFACE HIGH BRIEFLY SETTLES OVER THE REGION. BUT OVERNIGHT...A WEAK SURFACE TROUGH ASSOCIATED WITH A CLIPPER SYSTEM DIVING THROUGH THE GREAT LAKES WILL INDUCE SOUTHWEST WIND MAINLY OVER THE NORTHERN HALF OF THE AREA. FEEL THAT MOST PLACES WILL DROP TO THE MID 30S FOR LOWS TONIGHT...BUT THE WIND SHOULD KEEP FROST FROM BEING DEPOSITED LATE TONIGHT. THE MOST LIKELY PLACE TO SEE SOME FROST MAY VERY WELL BE OVER THE SOUTHERN HALF OF THE AREA. DO NOT HAVE ANY FROST IN THIS FORECAST...BUT MAY NEED TO ADD IT IN IF CONFIDENCE INCREASES TODAY. THE NAM GENERATES SOME RATHER GUSTY NORTHWEST WINDS BEHIND THE CLIPPER SYSTEM THURSDAY...ESPECIALLY OVER THE NORTHEAST. INCREASED WINDS SOME...BUT DID NOT GO UP TO NAM LEVELS AT THIS TIME. SURFACE HIGH PRESSURE WILL DOMINATE THE REGION AGAIN FOR MOST OF THURSDAY NIGHT. IT WILL GRADUALLY PUSH EAST OF THE AREA WHICH MAY ALLOW FOR A LIGHT SOUTHEAST WIND TO DEVELOP LATE IN THE WEST. THE MODELS ALSO SHOW SOME INCREASE IN CLOUD COVER IN THE WEST LATE THURSDAY NIGHT. THE BOTTOM LINE IS THE POTENTIAL FOR TEMPERATURES TO DROP INTO THE 30S AGAIN...ESPECIALLY EAST OF THE MISSISSIPPI RIVER. OF COURSE WILL HAVE TO WATCH FOR FROST POTENTIAL AS WELL. THE MODELS SEEM TO BE TRENDING SLOWER AND FARTHER SOUTH WITH THE QPF ASSOCIATED WITH THE RATHER WEAK MID-LEVEL TROUGH PUSHING OUT OF THE SOUTHERN/CENTRAL PLAINS FRIDAY. LOWERED POPS AND CONFINED GOOD CHANCE POPS TO SOUTHEAST MISSOURI IN THE AFTERNOON ONLY. LOOKS LIKE IT WILL BE MORE OF A STRATIFORM EVENT SO JUST MENTIONED RAIN. AS FOR TEMPERATURES...STAYED NEAR CONSENSUS OF GUIDANCE FOR HIGHS TODAY...BUT IN GENERAL FEEL THAT THE LOW END OF GUIDANCE IS THE PLACE TO BE FOR TONIGHT THROUGH FRIDAY. THE LONE EXCEPTION IS IN THE SOUTHWEST THURSDAY NIGHT...IF CLOUDS OR WINDS INCREASE. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 336 AM CDT WED APR 24 2013 WHILE STILL NOT COMPLETELY IN SYNC...LATEST MODEL OUTPUT HAS COME INTO BETTER ALIGNMENT WITH RESPECT TO THE SOUTHERN STREAM ENERGY FORECAST TO IMPACT THE REGION LATE IN THE WEEK. THERE IS CERTAINLY A TREND TO SHIFT THE MAIN FOCUS FOR PRECIPITATION TO THE SOUTH OF THE IMMEDIATE FORECAST AREA...MUCH AKIN TO WHAT THE ECMWF HAS BEEN INDICATING. THE SURFACE BOUNDARY IS NOW FORECAST BY ALL MODELS TO REMAIN SOUTH OF THE REGION...WHICH KEEPS SURFACE BASED INSTABILITY AT BAY. TO THAT EXTENT...ELEVATED INSTABILITY PARAMETERS ARE ALSO LACKING WITH THIS SYSTEM. THE END RESULT WAS TO ELIMINATE THE MENTION OF THUNDER FROM THE FRIDAY NIGHT/SATURDAY FORECAST. THE HIGHEST LIKELIHOOD FOR RAIN SHOWERS STILL APPEARS TO BE FRIDAY NIGHT INTO EARLY SATURDAY...WITH BETTER CHANCES SOUTH...SMALLER CHANCES NORTH. EXCEPT FOR THE GFS...MODELS ARE ALSO TRENDING DRIER LATE IN THE WEEKEND. KEPT SMALL CHANCES FOR SHOWERS OVER FAR EASTERN AREAS SATURDAY NIGHT AND SUNDAY AS THIS AREA WILL BE ON THE WESTERN PERIPHERY OF THE DEPARTING ENERGY. HIGH PRESSURE RIDGING IS FORECAST TO STRENGTHEN OVER THE EASTERN U.S. EARLY NEXT WEEK. CONSIDERING THE AMPLITUDE OF THIS RIDGE...THE GFS MAY BE TOO QUICK WITH THE APPROACH OF THE NEXT TROUGH AND ITS ASSOCIATED PRECIPITATION POTENTIAL. MAINTAINED SLIGHT CHANCE POPS IN THE TUESDAY FORECAST FOR NOW...BUT WOULD NOT BE SURPRISED TO SEE IT PUSHED TO LATER PERIODS PER THE 00Z ECMWF. A SLOW WARMING TREND IS EXPECTED THROUGH THE PERIOD. && .AVIATION... ISSUED AT 652 AM CDT WED APR 24 2013 THE BACK EDGE OF THE PRECIPITATION IS CLEARING KCGI NOW...AND IT SHOULD CONTINUE EASTWARD CLEARING ONE SITE AND HOUR THROUGH 15Z. PREVAILING MVFR AND TEMPO IFR CONDITIONS IN RAIN CAN BE EXPECTED AT ALL SITES. IFR CEILINGS MAY BE MORE PREVALENT AT KEVV AND KOWB...AND KOWB WILL LIKELY KEEP AN IFR CEILING THROUGH THE MORNING AFTER THE PRECIPITATION ENDS. WILL SEE GRADUAL IMPROVEMENT IN CEILINGS FROM WEST TO EAST THROUGH THE DAY. ALL TERMINALS SHOULD BE CLEAR BY AROUND 00Z. GUIDANCE SUGGESTS THAT GUSTY NORTHWEST WINDS WILL BE STRONGEST THIS MORNING AND THEN DIMINISH THROUGH THE AFTERNOON. WOULD EXPECT ALL TERMINALS TO QUICKLY BECOME CALM WITH/BY SUNSET. A LIGHT SOUTHWEST WIND IS LIKELY TO DEVELOP OVERNIGHT AT KEVV AND KOWB. NOT SURE IF A TANGIBLE SOUTHWEST WIND WILL DEVELOP FARTHER TO THE SOUTHWEST. GIVEN THE DRY ADVECTION EXPECTED THROUGH THE DAY...WILL NOT MENTION ANY FOG FORMATION LATE TONIGHT...DESPITE GOOD RADIATIONAL COOLING CONDITIONS FOR MUCH OF THE NIGHT FOLLOWING THIS MORNINGS RAINFALL. SOME FOG MAY NEED TO BE ADDED IN LATER FORECASTS. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ UPDATE...DRS SHORT TERM...DRS LONG TERM...RP AVIATION...DRS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
336 AM CDT WED APR 24 2013 .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 336 AM CDT WED APR 24 2013 BOTH THE SURFACE COLD FRONT AND THE MAIN POST-FRONTAL BAND OF SHOWERS AND THUNDERSTORMS ARE TAKING THEIR SWEET TIME TONIGHT. AS OF 08Z...THE COLD FRONT WAS LOCATED FROM NEAR FT CAMPBELL TO NEAR GREENVILLE KENTUCKY...AND THE BAND OF CONVECTION WAS LOCATED ALONG AND NORTHWEST OF A LINE FROM DONIPHAN MISSOURI TO MARION AND MT CARMEL ILLINOIS. WATER VAPOR IMAGERY SHOWS THE MAIN MID/UPPER LEVEL IMPULSE PIVOTING EASTWARD OVER THE SOUTHERN/CENTRAL PLAINS. THIS SHOULD HELP TO GIVE THE MAIN BAND A GOOD PUSH...AND MAY CAUSE IT TO PIVOT TO MORE OF A SOUTH SOUTHWEST TO NORTH NORTHEAST ORIENTATION THROUGH SUNRISE. USED THE LATEST RAP AS A GUIDE FOR HOURLY POP GRIDS THROUGH THE END OF THE EVENT. SHOULD SEE THE MAIN BAND PUSH SOUTHWARD TOWARD THE OHIO RIVER THROUGH SUNRISE...AND THEN GRADUALLY COME TO AN END FROM WEST TO EAST THROUGH THE MORNING. SCATTERED SHOWERS AND POSSIBLY A FEW THUNDERSTORMS WILL CONTINUE IN THE VICINITY OF THE FRONT IN THE SOUTHERN PENNYRILE THROUGH DAYBREAK...BUT THE MAIN BAND MAY NOT QUITE GET DOWN THAT FAR SOUTHEAST BEFORE BEING FORCED EAST OF THE AREA. THE SURFACE HIGH WILL PUSH EASTWARD ACROSS THE AREA THROUGH THE DAY WHICH SHOULD LEAD TO A NICE CLEARING TREND AND DIMINISHING WINDS. WINDS WILL GO NEARLY CALM THIS EVENING AS THE SURFACE HIGH BRIEFLY SETTLES OVER THE REGION. BUT OVERNIGHT...A WEAK SURFACE TROUGH ASSOCIATED WITH A CLIPPER SYSTEM DIVING THROUGH THE GREAT LAKES WILL INDUCE SOUTHWEST WIND MAINLY OVER THE NORTHERN HALF OF THE AREA. FEEL THAT MOST PLACES WILL DROP TO THE MID 30S FOR LOWS TONIGHT...BUT THE WIND SHOULD KEEP FROST FROM BEING DEPOSITED LATE TONIGHT. THE MOST LIKELY PLACE TO SEE SOME FROST MAY VERY WELL BE OVER THE SOUTHERN HALF OF THE AREA. DO NOT HAVE ANY FROST IN THIS FORECAST...BUT MAY NEED TO ADD IT IN IF CONFIDENCE INCREASES TODAY. THE NAM GENERATES SOME RATHER GUSTY NORTHWEST WINDS BEHIND THE CLIPPER SYSTEM THURSDAY...ESPECIALLY OVER THE NORTHEAST. INCREASED WINDS SOME...BUT DID NOT GO UP TO NAM LEVELS AT THIS TIME. SURFACE HIGH PRESSURE WILL DOMINATE THE REGION AGAIN FOR MOST OF THURSDAY NIGHT. IT WILL GRADUALLY PUSH EAST OF THE AREA WHICH MAY ALLOW FOR A LIGHT SOUTHEAST WIND TO DEVELOP LATE IN THE WEST. THE MODELS ALSO SHOW SOME INCREASE IN CLOUD COVER IN THE WEST LATE THURSDAY NIGHT. THE BOTTOM LINE IS THE POTENTIAL FOR TEMPERATURES TO DROP INTO THE 30S AGAIN...ESPECIALLY EAST OF THE MISSISSIPPI RIVER. OF COURSE WILL HAVE TO WATCH FOR FROST POTENTIAL AS WELL. THE MODELS SEEM TO BE TRENDING SLOWER AND FARTHER SOUTH WITH THE QPF ASSOCIATED WITH THE RATHER WEAK MID-LEVEL TROUGH PUSHING OUT OF THE SOUTHERN/CENTRAL PLAINS FRIDAY. LOWERED POPS AND CONFINED GOOD CHANCE POPS TO SOUTHEAST MISSOURI IN THE AFTERNOON ONLY. LOOKS LIKE IT WILL BE MORE OF A STRATIFORM EVENT SO JUST MENTIONED RAIN. AS FOR TEMPERATURES...STAYED NEAR CONSENSUS OF GUIDANCE FOR HIGHS TODAY...BUT IN GENERAL FEEL THAT THE LOW END OF GUIDANCE IS THE PLACE TO BE FOR TONIGHT THROUGH FRIDAY. THE LONE EXCEPTION IS IN THE SOUTHWEST THURSDAY NIGHT...IF CLOUDS OR WINDS INCREASE. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 336 AM CDT WED APR 24 2013 WHILE STILL NOT COMPLETELY IN SYNC...LATEST MODEL OUTPUT HAS COME INTO BETTER ALIGNMENT WITH RESPECT TO THE SOUTHERN STREAM ENERGY FORECAST TO IMPACT THE REGION LATE IN THE WEEK. THERE IS CERTAINLY A TREND TO SHIFT THE MAIN FOCUS FOR PRECIPITATION TO THE SOUTH OF THE IMMEDIATE FORECAST AREA...MUCH AKIN TO WHAT THE ECMWF HAS BEEN INDICATING. THE SURFACE BOUNDARY IS NOW FORECAST BY ALL MODELS TO REMAIN SOUTH OF THE REGION...WHICH KEEPS SURFACE BASED INSTABILITY AT BAY. TO THAT EXTENT...ELEVATED INSTABILITY PARAMETERS ARE ALSO LACKING WITH THIS SYSTEM. THE END RESULT WAS TO ELIMINATE THE MENTION OF THUNDER FROM THE FRIDAY NIGHT/SATURDAY FORECAST. THE HIGHEST LIKELIHOOD FOR RAIN SHOWERS STILL APPEARS TO BE FRIDAY NIGHT INTO EARLY SATURDAY...WITH BETTER CHANCES SOUTH...SMALLER CHANCES NORTH. EXCEPT FOR THE GFS...MODELS ARE ALSO TRENDING DRIER LATE IN THE WEEKEND. KEPT SMALL CHANCES FOR SHOWERS OVER FAR EASTERN AREAS SATURDAY NIGHT AND SUNDAY AS THIS AREA WILL BE ON THE WESTERN PERIPHERY OF THE DEPARTING ENERGY. HIGH PRESSURE RIDGING IS FORECAST TO STRENGTHEN OVER THE EASTERN U.S. EARLY NEXT WEEK. CONSIDERING THE AMPLITUDE OF THIS RIDGE...THE GFS MAY BE TOO QUICK WITH THE APPROACH OF THE NEXT TROUGH AND ITS ASSOCIATED PRECIPITATION POTENTIAL. MAINTAINED SLIGHT CHANCE POPS IN THE TUESDAY FORECAST FOR NOW...BUT WOULD NOT BE SURPRISED TO SEE IT PUSHED TO LATER PERIODS PER THE 00Z ECMWF. A SLOW WARMING TREND IS EXPECTED THROUGH THE PERIOD. && .AVIATION... ISSUED AT 1157 PM CDT TUE APR 23 2013 LOW MVFR CIGS WILL GRADUALLY LOWER TO LOW MVFR/IFR AS MORE WIDESPREAD SHRA DEVELOP AND SPREAD SOUTHEAST ACROSS TAF SITES BETWEEN 08Z AND 12Z. MVFR VSBYS EXPECTED WITH SHRA. ISOLATED TSRA POSSIBLE...BUT CHANCES ARE TOO LOW TO INCLUDE. WINDS WILL BE FROM THE NORTHWEST AT 8 TO 15 KTS WITH SOME HIGHER GUSTS. SHRA WILL TAPER OFF FROM NORTHWEST TO SOUTHEAST AFTER 14Z. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ SHORT TERM...DRS LONG TERM...RP AVIATION....RST
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
859 PM EDT THU APR 25 2013 .SYNOPSIS... AFTER A COOL NIGHT...HIGH PRESSURE WITH SUNSHINE WILL QUICKLY RETURN TEMPERATURES TO SEASONAL LEVELS FOR FRIDAY AND SATURDAY. && .NEAR TERM /THROUGH FRIDAY/... NO CHANGES NEEDED FOR THE LATE EVE UPDATE OTHER THAN TO TWEAK HOURLY TRENDS. AREA OF SCT SHOWERS UNDER A CROSSING SHORTWAVE...BEST EXHIBITED VIA UAA OR RAP MDL DEPICTION OF MID LVL THERMAL TROF...WL QUICKLY SHIFT EWD AS THE EVE PROGRESSES. DRY HIGH PRESSURE WL BUILD OVRNGT...CLEARING THE SKY AND CALMING THE WIND. CONDITIONS LK TO BE SUFFICIENTLY LONG FOR A CPL HOURS OF FREEZING TEMPS OR AREAS OF FROST. FROST ADVISORY THUS REMAINS IN EFFECT FOR AREAS WHERE SPRING HEADLINES HAVE STARTED AFTER CONSULTATIONS WITH LOCAL GROWERS...I.E. GENERALLY WEST OF THE RIDGES AND SOUTH OF THE PA TURNPIKE. WITH ABUNDANT INSOLATION...FRIDAY TEMPS ARE EXPECTED TO RECOVER TO NEAR THE SEASONAL AVERAGES. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... DRY AND SEASONABLE WEA WL CONT AS SURFACE RIDGE SHIFTS EAST THROUGH SATURDAY. FOR SATURDAY NIGHT AND SUNDAY...CLOUDS WILL BE INCREASING AS A SOUTHERN STREAM SHORTWAVE MOVES TOWARD THE UPPER OHIO VALLEY. POPS WERE LIMITED TO CHC NMBRS FOR SUNDAY AS BEST MOISTURE AND LIFT ARE PROJECTED TO STAY SOUTH OF REGION. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... A WK SHRTWV WL MOVE ACRS THE OH VLY SUN NGT INTO MONDAY CONTG THE CHC OF SHOWERS. HIGH PRESSURE IS THEN FORECAST TO BUILD WITH DRY WEA AND WARMER TEMPS INTO MIDWEEK. RAIN CHCS WL INCRS THEREAFTER AS TROFFING DVLPS OVR THE GREAT LAKES. && .AVIATION /01Z FRIDAY THROUGH TUESDAY/... FAST MOVING SHORTWAVE WILL CONTINUE TO CAUSE SCATTERED -SHRA ACROSS THE NORTHERN TERMINALS AND WILL END BEFORE MIDNIGHT. MVFR POSSIBLE AT TIMES OVER KDUJ AND KFKL...OTHERWISE VFR CONDITIONS WILL PERSIST AT THOSE LOCATIONS AND ELSEWHERE. BUILDING HIGH PRESSURE TONIGHT WILL YIELD TO VFR THROUGH THE TAF PERIOD. .OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/... GENL VFR CONDS ARE EXPECTED THRU SAT NGT. SHRA AND RESULTING RESTRICTIONS ARE PSBL SUN INTO MONDAY WITH A WK WAVE OF LOW PRES...BUT HIGH PRES IS FORECAST TO QUICKLY REBUILD AND RTN VFR FOR MON NGT INTO TUE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...FROST ADVISORY FROM 3 AM TO 9 AM EDT FRIDAY FOR OHZ039>041- 048>050-057>059-068-069. PA...FROST ADVISORY FROM 3 AM TO 9 AM EDT FRIDAY FOR PAZ020-021-029- 031-073-075. WV...FROST ADVISORY FROM 3 AM TO 9 AM EDT FRIDAY FOR WVZ001>004-012- 021-022. && $$ 15
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
106 PM EDT WED APR 24 2013 .AVIATION... //DISCUSSION... LOW MVFR/HIGH IFR CONDITIONS WILL CONTINUE TO ACCOMPANY WIDESPREAD RAIN AND SNOW SHOWERS FOR THE REMAINDER OF THE AFTERNOON, PARTICULARLY FOR KFNT AND POINTS SOUTH, AS A WAVE LIFTS INTO SOUTHEAST MICHIGAN. ALTHOUGH LITTLE TO NO ACCUMULATION IS FORECAST, VISIBILITY WITHIN REGIONS OF HEAVIER SNOWFALL WILL FALL TO AS LOW AS 1SM. RAIN WILL BECOME INCREASINGLY FAVORED OVER SNOW AS THE AFTERNOON WEARS ON GIVEN GRADUAL DIURNAL HEATING OF THE BOUNDARY LAYER ALONG WITH DECLINING PRECIPITATION INTENSITY. WITH THE EXIT OF DEEPER MOISTURE TO THE EAST BY THIS EVENING, PRECIPITATION WILL TRANSITION TO DRIZZLE AND EVENTUALLY COME TO AN END BY AROUND 21Z WITH GRADUAL IMPROVEMENT TO ALL MVFR WITH VFR CONDITIONS BUILDING IN FOR THE OVERNIGHT PERIOD. WESTERLY WINDS WILL PERSIST THROUGH LATE EVENING BEFORE A SURFACE RIDGE AXIS TRANSITS THE AREA AND FORCES WINDS TO TURN SOUTHERLY PRIOR TO DAYBREAK ON THURSDAY. CONDITIONS WILL ONCE AGAIN DETERIORATE TO MVFR AS ANOTHER ROUND OF SHOWERS APPROACHES FOR THURSDAY MORNING. //DTW THRESHOLD THREATS... * HIGH CONFIDENCE IN CEILINGS BELOW 5000 FEET THROUGH LATE AFTERNOON * HIGH CONFIDENCE IN MIXED RAIN AND SNOW PTYPE && .PREV DISCUSSION...ISSUED 350 AM EDT WED APR 24 2013 SHORT TERM...TODAY AND TONIGHT BY FORECAST ISSUANCE TIME...WEAK SFC LOW PRESSURE AND A COLD FRONT WILL BE PUSHING EAST OF METRO DETROIT AND PORT HURON. THERE HAS BEEN A FAIRLY WIDESPREAD AREA OF RAINFALL ACROSS SE MI ALONG AND BEHIND THE SFC FRONT LAST NIGHT WITHIN A REGION OF STRONG LOWER TROPOSPHERIC FRONTOGENESIS. THE HEAVIER AND MORE PERSISTENT RAINFALL HAS OCCURRED WITHIN THE 800-700MB LAYER OF THE FRONTAL SLOPE. THIS TARGETED THE TRI CITIES AND SAGINAW BAY REGION WHERE RADAR ESTIMATED RAINFALL IS ALREADY AROUND AN INCH. THE REGION OF HIGHER INTENSITY RAINFALL IS EXPECTED TO SHIFT INTO THE THUMB REGION DURING THE EARLY MORNING HOURS. GIVEN THE ESTIMATED RAINFALL AND WITH THE EXPECTATION FOR HIGHER INTENSITY RAINFALL TO PUSH INTO THE THUMB...THE FLOOD WATCH WILL BE CONTINUED THROUGH DAYBREAK. THERE HAVE BEEN A FEW AWOS SITES WHICH HAVE REPORTED SNOW OVERNIGHT... WHICH IS INCORRECT. ALL PRECIP THUS FAR HAS BEEN IN THE FORM OF RAIN. THE NAM AND GFS SOLUTIONS APPEAR TOO COOL IN THE BOUNDARY LAYER THIS MORNING IN COMPARISON TO OBSERVATIONS...WITH THE RAP SOUNDINGS APPEARING TO HAVE A BETTER HANDLE ON THE LOW LEVEL THERMAL PROFILES. THE RAP IS SUGGESTIVE OF PRECIP REMAINING MOSTLY RAIN THIS MORNING...EXPECT ACROSS THE TRI CITIES AND THUMB WHERE COLDER AIR CONTINUES TO FILTER IN FROM THE NW AND IS LIKELY TO CAUSE A MIX OR BRIEF CHANGE OVER TO SNOW. THE LOW TO MID LEVEL FGEN RESPONSE WILL WEAKEN TOWARD DAYBREAK THROUGH LATE MORNING DUE TO THE LOW LEVEL THERMAL GRADIENT RELAXING AS SFC LOW PRESSURE AND BETTER UPPER DYNAMICS SHIFT OFF TO THE NORTHEAST. THIS WILL LEAD TO A STEADY DECREASE IN COVERAGE AND INTENSITY OF THE RAINFALL. HOWEVER...THE UPPER LEVEL WAVE NOTED OVER KANSAS IS FORECAST TO RAPIDLY LIFT ACROSS THE NRN OH VALLEY AND ERN GREAT LAKES THIS AFTERNOON. MODEL SOLUTIONS HAVE TRENDED TOWARD A DEEPER UPPER WAVE/STRONGER UPPER LEVEL POTENTIAL VORTICITY ADVECTION WITH THIS FEATURE AND APPEAR WELL INITIALIZED. AS IT LIFTS NE THIS AFTERNOON...SOME WEAK MID LEVEL DEFORMATION WILL OVERSPREAD SE MI... ESPECIALLY THE EASTERN HALF OF THE FORECAST AREA. AN INTENSIFICATION OF AN UPPER JET STREAK WILL OCCUR ACROSS LOWER MI AND LAKE HURON AS WELL...WITH INCREASING DIVERGENCE OVERSPREADING OHIO...LAKE ERIE AND FAR EASTERN PORTIONS OF SE MI. THIS FORCING WILL INTERACT WITH THE BACK EDGE OF THE DEEPER MOISTURE PLUME OVER SE MI...SUGGESTING RAINFALL WILL INCREASE IN COVERAGE AGAIN DURING THE AFTERNOON. THE RATHER MARGINAL FORCING SUGGEST ADDITIONAL DAYTIME RAINFALL AMOUNTS WILL GENERALLY REMAIN BELOW A QUARTER INCH. THE EXPECTATION FOR ENOUGH DAYTIME WARMING IN THE BOUNDARY LAYER SUPPORTS PRECIP TYPE AS ALL RAIN TODAY. ALTHOUGH WITH 850MB TEMPS FORECAST TO DROP TO -5C...THERE WAS SOME SERIES CONTEMPLATION OVER ADDING A MENTION OF SOME SNOW NORTH OF METRO DETROIT. THE EXTENT OF CLOUDS AND RAIN TODAY...WITH DWPTS DROPPING INTO THE LOW 30S...WILL SUPPRESS TEMPS TO THE MID 30S TO LOWER 40S WELL INTO THE AFTERNOON. A PUSH OF DRIER AIR LATE IN THE AFTERNOON AND EVENING WILL END THE RAIN AND CAUSE SOME PARTIAL CLEARING WHICH SHOULD ALLOW A LATE DAY SPIKE IN TEMPS INTO THE MID-UPPER 40S. PARTIAL CLEARING TONIGHT AMIDST SHORT WAVE RIDGING WILL ALLOW ENOUGH OPPORTUNITY FOR NIGHTTIME COOLING TO DROP TEMPS WELL DOWN INTO THE 30S. LONG TERM...THURSDAY THROUGH TUESDAY STRONG UPPER WAVE OVER SASKATCHEWAN WILL DIVE DOWN INTO THE WESTERN GREAT LAKES BY THURSDAY MORNING...AS IT ROTATES WITHIN THE LONGWAVE TROUGH OVER THE CENTRAL U.S. AND CANADA. THIS WAVE WILL CLIP QUICKLY ACROSS LOWER MICHIGAN AND INTO ONTARIO THURSDAY...PUSHING A WEAK LOW PRESSURE SYSTEM ACROSS THE NORTHERN GREAT LAKES AND DRAGGING A COLD FRONT ACROSS THE AREA. FRONTAL TIMING CONTINUES TO VARY WITHIN THE MODELS...AND STRONG PREFERENCE GOES TO THE VERY CONSISTENT EURO MODEL. GOOD BURST OF LIFT WILL ACCOMPANY THE COLD FRONT...WITH FRONTAL DYNAMICS STACKED UNDERNEATH MID-LEVEL PVA AND LEFT EXIT REGION FORCING. COLD AIR ALOFT REMAINING IN PLACE BEHIND TODAY`S SYSTEM IN COMBINATION WITH H500 TEMPS DROPPING TO ABOUT -35C WITH THE UPPER WAVE...WHICH HAS ARCTIC ORIGINS...WILL CREATE VERY MODERATELY STEEP LOW AND MID-LEVEL LAPSE RATES (FROM SURFACE UP THROUGH 400MB). DEEP LAYER OF INSTABILITY WILL HELP MAXIMIZE RESPONSE FROM FORCING AND MAKE THE BEST OF ONLY MEAGER MOISTURE (SHALLOW LAYER OF MOISTURE POOLING AHEAD OF FRONT WITH SPECIFIC HUMIDITY 3 G/KG AND PW OVERALL ONLY AROUND 0.4 INCHES). PRECIPITATION ASSOCIATED WITH THE FRONT WILL AFFECT THE AREA DURING THE FIRST HALF OF THURSDAY...WITH ADDITIONAL SHOWERS POSSIBLY REDEVELOPING DURING THE LATE AFTERNOON AS LAPSE RATES FURTHER STEEPEN AND SOME MOISTURE LINGERS. PRECIPITATION TYPE IS STILL A LITTLE UNCERTAIN WITH GFS/NAM FORECAST SOUNDINGS STILL HINTING THAT SNOW MAY BE POSSIBLE...BUT GIVEN WARMER EURO PROFILES IN THE PAST TWO MODEL RUNS...WILL KEEP PRECIP TYPE AS RAIN. WOULD ALSO EXPECT TO SEE SOME GRAUPEL FALL AS SHOWERS WILL HAVE A CONVECTIVE ELEMENT TO THEM AND FREEZING LEVELS WILL BE VERY LOW. SURFACE HIGH PRESSURE WILL EXPAND INTO THE AREA FROM THE OHIO VALLEY THURSDAY NIGHT AND FRIDAY BRINGING DRY WEATHER BACK TO THE AREA. LOW PRESSURE TRACKING ACROSS HUDSON BAY WILL DRAW SOME WARMER AIR UP INTO THE REGION ON FRIDAY...ALLOWING TEMPERATURES TO CREEP BACK UP INTO THE UPPER 50S. WEEKEND WILL BE MARKED BY ZONAL FLOW...WITH UPPER RIDGING BUILDING INTO THE GREAT LAKES MONDAY AND TUESDAY IN RESPONSE TO TROUGHING DROPPING DOWN INTO THE NORTHERN ROCKIES. WILL SEE A WARMING TREND DURING THIS STRETCH...WITH MAX TEMPERATURES GRADUALLY WARMING TO AROUND 70. MODELS HAVE BEEN TRYING TO GENERATE CONVECTION JUST ABOUT EVERY AFTERNOON AS LAPSE RATES STEEPEN DURING THE DAY. GIVEN GENERAL LACK OF GOOD MOISTURE ADVECTION (HAVE A FEELING SURFACE TD`S ARE TOO HIGH AS WELL) AND EVENTUAL CAPPING FROM THE RIDGE...ELECTED TO KEEP THE FORECAST DRY AND THUNDERSTORM FREE FOR NOW. MARINE... NORTHWEST WINDS IN THE WAKE OF LAST NIGHTS COLD FRONTAL PASSAGE HAS USHERED IN COLDER AIR...LEADING TO UNSTABLE CONDITIONS OVER THE LAKES. SOME GUSTS UP TO 25 KNOTS ARE EXPECTED OVER THE OPEN WATERS OF LAKE HURON. THESE CONDITIONS SHOULD BE SHORT LIVED AS HIGH PRESSURE BUILDS IN FROM THE WEST LATE THIS AFTERNOON AND ALLOWS WINDS AND WAVES TO RELAX. A FAST MOVING LOW PRESSURE SYSTEM WILL THEN TRAVERSE THE REGION ON THURSDAY. THE GRADIENT WILL NOT BE TOO TERRIBLE STRONG...BUT COULD LEAD TO SOME GUSTS UP TO 25 KNOTS OVER LAKES ST CLAIR...ERIE AND THE SOUTHERN BASIN OF LAKE HURON. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON... SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT HURON...UNTIL 5 PM WEDNESDAY. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....JVC SHORT TERM...SC LONG TERM....HLO MARINE.......SC YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
701 AM EDT WED APR 24 2013 .AVIATION... //DISCUSSION... PRECIPITATION WILL CONTINUE TO TAPER OFF EARLY THIS MORNING. LIGHT RAIN IS EXPECTED TO REDEVELOP OVER SE MI IN THE 15Z TO 18Z TIME FRAME AS AN UPPER WAVE LIFTS TOWARD THE OHIO VALLEY. THIS RAINFALL WILL THEN END FROM WEST TO EAST LATER IN THE AFTERNOON AS MUCH DRIER AIR PUSHES IN FROM THE WEST. THE INITIAL IFR CEILINGS IN THE POST FRONTAL ENVIRONMENT THIS MORNING WILL SLOWLY LIFT OVER THE NEXT SEVERAL HOURS AS DRYER AIR BELOW 3000 FT CONTINUES TO ADVECT INTO THE REGION FROM THE NORTHWEST. FOR DTW...WHILE THERE IS SOME POTENTIAL FOR IFR CEILINGS TO PERSIST OFF AND ON INTO THE EARLY AFTERNOON...THE OVERALL TRENDS WILL BE TOWARD RISING CEILINGS DESPITE AN ADDITIONAL ROUND OF LIGHT RAIN DEVELOPING LATE THIS MORNING/EARLY THIS AFTERNOON. //DTW THRESHOLD THREATS... * HIGH CONFIDENCE IN CEILINGS BELOW 5000 FT THROUGH LATE AFTERNOON. && .PREV DISCUSSION...ISSUED 350 AM EDT WED APR 24 2013 SHORT TERM...TODAY AND TONIGHT BY FORECAST ISSUANCE TIME...WEAK SFC LOW PRESSURE AND A COLD FRONT WILL BE PUSHING EAST OF METRO DETROIT AND PORT HURON. THERE HAS BEEN A FAIRLY WIDESPREAD AREA OF RAINFALL ACROSS SE MI ALONG AND BEHIND THE SFC FRONT LAST NIGHT WITHIN A REGION OF STRONG LOWER TROPOSPHERIC FRONTOGENESIS. THE HEAVIER AND MORE PERSISTENT RAINFALL HAS OCCURRED WITHIN THE 800-700MB LAYER OF THE FRONTAL SLOPE. THIS TARGETED THE TRI CITIES AND SAGINAW BAY REGION WHERE RADAR ESTIMATED RAINFALL IS ALREADY AROUND AN INCH. THE REGION OF HIGHER INTENSITY RAINFALL IS EXPECTED TO SHIFT INTO THE THUMB REGION DURING THE EARLY MORNING HOURS. GIVEN THE ESTIMATED RAINFALL AND WITH THE EXPECTATION FOR HIGHER INTENSITY RAINFALL TO PUSH INTO THE THUMB...THE FLOOD WATCH WILL BE CONTINUED THROUGH DAYBREAK. THERE HAVE BEEN A FEW AWOS SITES WHICH HAVE REPORTED SNOW OVERNIGHT... WHICH IS INCORRECT. ALL PRECIP THUS FAR HAS BEEN IN THE FORM OF RAIN. THE NAM AND GFS SOLUTIONS APPEAR TOO COOL IN THE BOUNDARY LAYER THIS MORNING IN COMPARISON TO OBSERVATIONS...WITH THE RAP SOUNDINGS APPEARING TO HAVE A BETTER HANDLE ON THE LOW LEVEL THERMAL PROFILES. THE RAP IS SUGGESTIVE OF PRECIP REMAINING MOSTLY RAIN THIS MORNING...EXPECT ACROSS THE TRI CITIES AND THUMB WHERE COLDER AIR CONTINUES TO FILTER IN FROM THE NW AND IS LIKELY TO CAUSE A MIX OR BRIEF CHANGE OVER TO SNOW. THE LOW TO MID LEVEL FGEN RESPONSE WILL WEAKEN TOWARD DAYBREAK THROUGH LATE MORNING DUE TO THE LOW LEVEL THERMAL GRADIENT RELAXING AS SFC LOW PRESSURE AND BETTER UPPER DYNAMICS SHIFT OFF TO THE NORTHEAST. THIS WILL LEAD TO A STEADY DECREASE IN COVERAGE AND INTENSITY OF THE RAINFALL. HOWEVER...THE UPPER LEVEL WAVE NOTED OVER KANSAS IS FORECAST TO RAPIDLY LIFT ACROSS THE NRN OH VALLEY AND ERN GREAT LAKES THIS AFTERNOON. MODEL SOLUTIONS HAVE TRENDED TOWARD A DEEPER UPPER WAVE/STRONGER UPPER LEVEL POTENTIAL VORTICITY ADVECTION WITH THIS FEATURE AND APPEAR WELL INITIALIZED. AS IT LIFTS NE THIS AFTERNOON...SOME WEAK MID LEVEL DEFORMATION WILL OVERSPREAD SE MI... ESPECIALLY THE EASTERN HALF OF THE FORECAST AREA. AN INTENSIFICATION OF AN UPPER JET STREAK WILL OCCUR ACROSS LOWER MI AND LAKE HURON AS WELL...WITH INCREASING DIVERGENCE OVERSPREADING OHIO...LAKE ERIE AND FAR EASTERN PORTIONS OF SE MI. THIS FORCING WILL INTERACT WITH THE BACK EDGE OF THE DEEPER MOISTURE PLUME OVER SE MI...SUGGESTING RAINFALL WILL INCREASE IN COVERAGE AGAIN DURING THE AFTERNOON. THE RATHER MARGINAL FORCING SUGGEST ADDITIONAL DAYTIME RAINFALL AMOUNTS WILL GENERALLY REMAIN BELOW A QUARTER INCH. THE EXPECTATION FOR ENOUGH DAYTIME WARMING IN THE BOUNDARY LAYER SUPPORTS PRECIP TYPE AS ALL RAIN TODAY. ALTHOUGH WITH 850MB TEMPS FORECAST TO DROP TO -5C...THERE WAS SOME SERIES CONTEMPLATION OVER ADDING A MENTION OF SOME SNOW NORTH OF METRO DETROIT. THE EXTENT OF CLOUDS AND RAIN TODAY...WITH DWPTS DROPPING INTO THE LOW 30S...WILL SUPPRESS TEMPS TO THE MID 30S TO LOWER 40S WELL INTO THE AFTERNOON. A PUSH OF DRIER AIR LATE IN THE AFTERNOON AND EVENING WILL END THE RAIN AND CAUSE SOME PARTIAL CLEARING WHICH SHOULD ALLOW A LATE DAY SPIKE IN TEMPS INTO THE MID-UPPER 40S. PARTIAL CLEARING TONIGHT AMIDST SHORT WAVE RIDGING WILL ALLOW ENOUGH OPPORTUNITY FOR NIGHTTIME COOLING TO DROP TEMPS WELL DOWN INTO THE 30S. LONG TERM...THURSDAY THROUGH TUESDAY STRONG UPPER WAVE OVER SASKATCHEWAN WILL DIVE DOWN INTO THE WESTERN GREAT LAKES BY THURSDAY MORNING...AS IT ROTATES WITHIN THE LONGWAVE TROUGH OVER THE CENTRAL U.S. AND CANADA. THIS WAVE WILL CLIP QUICKLY ACROSS LOWER MICHIGAN AND INTO ONTARIO THURSDAY...PUSHING A WEAK LOW PRESSURE SYSTEM ACROSS THE NORTHERN GREAT LAKES AND DRAGGING A COLD FRONT ACROSS THE AREA. FRONTAL TIMING CONTINUES TO VARY WITHIN THE MODELS...AND STRONG PREFERENCE GOES TO THE VERY CONSISTENT EURO MODEL. GOOD BURST OF LIFT WILL ACCOMPANY THE COLD FRONT...WITH FRONTAL DYNAMICS STACKED UNDERNEATH MID-LEVEL PVA AND LEFT EXIT REGION FORCING. COLD AIR ALOFT REMAINING IN PLACE BEHIND TODAY`S SYSTEM IN COMBINATION WITH H500 TEMPS DROPPING TO ABOUT -35C WITH THE UPPER WAVE...WHICH HAS ARCTIC ORIGINS...WILL CREATE VERY MODERATELY STEEP LOW AND MID-LEVEL LAPSE RATES (FROM SURFACE UP THROUGH 400MB). DEEP LAYER OF INSTABILITY WILL HELP MAXIMIZE RESPONSE FROM FORCING AND MAKE THE BEST OF ONLY MEAGER MOISTURE (SHALLOW LAYER OF MOISTURE POOLING AHEAD OF FRONT WITH SPECIFIC HUMIDITY 3 G/KG AND PW OVERALL ONLY AROUND 0.4 INCHES). PRECIPITATION ASSOCIATED WITH THE FRONT WILL AFFECT THE AREA DURING THE FIRST HALF OF THURSDAY...WITH ADDITIONAL SHOWERS POSSIBLY REDEVELOPING DURING THE LATE AFTERNOON AS LAPSE RATES FURTHER STEEPEN AND SOME MOISTURE LINGERS. PRECIPITATION TYPE IS STILL A LITTLE UNCERTAIN WITH GFS/NAM FORECAST SOUNDINGS STILL HINTING THAT SNOW MAY BE POSSIBLE...BUT GIVEN WARMER EURO PROFILES IN THE PAST TWO MODEL RUNS...WILL KEEP PRECIP TYPE AS RAIN. WOULD ALSO EXPECT TO SEE SOME GRAUPEL FALL AS SHOWERS WILL HAVE A CONVECTIVE ELEMENT TO THEM AND FREEZING LEVELS WILL BE VERY LOW. SURFACE HIGH PRESSURE WILL EXPAND INTO THE AREA FROM THE OHIO VALLEY THURSDAY NIGHT AND FRIDAY BRINGING DRY WEATHER BACK TO THE AREA. LOW PRESSURE TRACKING ACROSS HUDSON BAY WILL DRAW SOME WARMER AIR UP INTO THE REGION ON FRIDAY...ALLOWING TEMPERATURES TO CREEP BACK UP INTO THE UPPER 50S. WEEKEND WILL BE MARKED BY ZONAL FLOW...WITH UPPER RIDGING BUILDING INTO THE GREAT LAKES MONDAY AND TUESDAY IN RESPONSE TO TROUGHING DROPPING DOWN INTO THE NORTHERN ROCKIES. WILL SEE A WARMING TREND DURING THIS STRETCH...WITH MAX TEMPERATURES GRADUALLY WARMING TO AROUND 70. MODELS HAVE BEEN TRYING TO GENERATE CONVECTION JUST ABOUT EVERY AFTERNOON AS LAPSE RATES STEEPEN DURING THE DAY. GIVEN GENERAL LACK OF GOOD MOISTURE ADVECTION (HAVE A FEELING SURFACE TD`S ARE TOO HIGH AS WELL) AND EVENTUAL CAPPING FROM THE RIDGE...ELECTED TO KEEP THE FORECAST DRY AND THUNDERSTORM FREE FOR NOW. MARINE... NORTHWEST WINDS IN THE WAKE OF LAST NIGHTS COLD FRONTAL PASSAGE HAS USHERED IN COLDER AIR...LEADING TO UNSTABLE CONDITIONS OVER THE LAKES. SOME GUSTS UP TO 25 KNOTS ARE EXPECTED OVER THE OPEN WATERS OF LAKE HURON. THESE CONDITIONS SHOULD BE SHORT LIVED AS HIGH PRESSURE BUILDS IN FROM THE WEST LATE THIS AFTERNOON AND ALLOWS WINDS AND WAVES TO RELAX. A FAST MOVING LOW PRESSURE SYSTEM WILL THEN TRAVERSE THE REGION ON THURSDAY. THE GRADIENT WILL NOT BE TOO TERRIBLE STRONG...BUT COULD LEAD TO SOME GUSTS UP TO 25 KNOTS OVER LAKES ST CLAIR...ERIE AND THE SOUTHERN BASIN OF LAKE HURON. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON... SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT HURON...UNTIL 5 PM WEDNESDAY. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....SC SHORT TERM...SC LONG TERM....HLO MARINE.......SC YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
350 AM EDT WED APR 24 2013 .SHORT TERM...TODAY AND TONIGHT BY FORECAST ISSUANCE TIME...WEAK SFC LOW PRESSURE AND A COLD FRONT WILL BE PUSHING EAST OF METRO DETROIT AND PORT HURON. THERE HAS BEEN A FAIRLY WIDESPREAD AREA OF RAINFALL ACROSS SE MI ALONG AND BEHIND THE SFC FRONT LAST NIGHT WITHIN A REGION OF STRONG LOWER TROPOSPHERIC FRONTOGENESIS. THE HEAVIER AND MORE PERSISTENT RAINFALL HAS OCCURRED WITHIN THE 800-700MB LAYER OF THE FRONTAL SLOPE. THIS TARGETED THE TRI CITIES AND SAGINAW BAY REGION WHERE RADAR ESTIMATED RAINFALL IS ALREADY AROUND AN INCH. THE REGION OF HIGHER INTENSITY RAINFALL IS EXPECTED TO SHIFT INTO THE THUMB REGION DURING THE EARLY MORNING HOURS. GIVEN THE ESTIMATED RAINFALL AND WITH THE EXPECTATION FOR HIGHER INTENSITY RAINFALL TO PUSH INTO THE THUMB...THE FLOOD WATCH WILL BE CONTINUED THROUGH DAYBREAK. THERE HAVE BEEN A FEW AWOS SITES WHICH HAVE REPORTED SNOW OVERNIGHT... WHICH IS INCORRECT. ALL PRECIP THUS FAR HAS BEEN IN THE FORM OF RAIN. THE NAM AND GFS SOLUTIONS APPEAR TOO COOL IN THE BOUNDARY LAYER THIS MORNING IN COMPARISON TO OBSERVATIONS...WITH THE RAP SOUNDINGS APPEARING TO HAVE A BETTER HANDLE ON THE LOW LEVEL THERMAL PROFILES. THE RAP IS SUGGESTIVE OF PRECIP REMAINING MOSTLY RAIN THIS MORNING...EXPECT ACROSS THE TRI CITIES AND THUMB WHERE COLDER AIR CONTINUES TO FILTER IN FROM THE NW AND IS LIKELY TO CAUSE A MIX OR BRIEF CHANGE OVER TO SNOW. THE LOW TO MID LEVEL FGEN RESPONSE WILL WEAKEN TOWARD DAYBREAK THROUGH LATE MORNING DUE TO THE LOW LEVEL THERMAL GRADIENT RELAXING AS SFC LOW PRESSURE AND BETTER UPPER DYNAMICS SHIFT OFF TO THE NORTHEAST. THIS WILL LEAD TO A STEADY DECREASE IN COVERAGE AND INTENSITY OF THE RAINFALL. HOWEVER...THE UPPER LEVEL WAVE NOTED OVER KANSAS IS FORECAST TO RAPIDLY LIFT ACROSS THE NRN OH VALLEY AND ERN GREAT LAKES THIS AFTERNOON. MODEL SOLUTIONS HAVE TRENDED TOWARD A DEEPER UPPER WAVE/STRONGER UPPER LEVEL POTENTIAL VORTICITY ADVECTION WITH THIS FEATURE AND APPEAR WELL INITIALIZED. AS IT LIFTS NE THIS AFTERNOON...SOME WEAK MID LEVEL DEFORMATION WILL OVERSPREAD SE MI... ESPECIALLY THE EASTERN HALF OF THE FORECAST AREA. AN INTENSIFICATION OF AN UPPER JET STREAK WILL OCCUR ACROSS LOWER MI AND LAKE HURON AS WELL...WITH INCREASING DIVERGENCE OVERSPREADING OHIO...LAKE ERIE AND FAR EASTERN PORTIONS OF SE MI. THIS FORCING WILL INTERACT WITH THE BACK EDGE OF THE DEEPER MOISTURE PLUME OVER SE MI...SUGGESTING RAINFALL WILL INCREASE IN COVERAGE AGAIN DURING THE AFTERNOON. THE RATHER MARGINAL FORCING SUGGEST ADDITIONAL DAYTIME RAINFALL AMOUNTS WILL GENERALLY REMAIN BELOW A QUARTER INCH. THE EXPECTATION FOR ENOUGH DAYTIME WARMING IN THE BOUNDARY LAYER SUPPORTS PRECIP TYPE AS ALL RAIN TODAY. ALTHOUGH WITH 850MB TEMPS FORECAST TO DROP TO -5C...THERE WAS SOME SERIES CONTEMPLATION OVER ADDING A MENTION OF SOME SNOW NORTH OF METRO DETROIT. THE EXTENT OF CLOUDS AND RAIN TODAY...WITH DWPTS DROPPING INTO THE LOW 30S...WILL SUPPRESS TEMPS TO THE MID 30S TO LOWER 40S WELL INTO THE AFTERNOON. A PUSH OF DRIER AIR LATE IN THE AFTERNOON AND EVENING WILL END THE RAIN AND CAUSE SOME PARTIAL CLEARING WHICH SHOULD ALLOW A LATE DAY SPIKE IN TEMPS INTO THE MID-UPPER 40S. PARTIAL CLEARING TONIGHT AMIDST SHORT WAVE RIDGING WILL ALLOW ENOUGH OPPORTUNITY FOR NIGHTTIME COOLING TO DROP TEMPS WELL DOWN INTO THE 30S. && .LONG TERM...THURSDAY THROUGH TUESDAY STRONG UPPER WAVE OVER SASKATCHEWAN WILL DIVE DOWN INTO THE WESTERN GREAT LAKES BY THURSDAY MORNING...AS IT ROTATES WITHIN THE LONGWAVE TROUGH OVER THE CENTRAL U.S. AND CANADA. THIS WAVE WILL CLIP QUICKLY ACROSS LOWER MICHIGAN AND INTO ONTARIO THURSDAY...PUSHING A WEAK LOW PRESSURE SYSTEM ACROSS THE NORTHERN GREAT LAKES AND DRAGGING A COLD FRONT ACROSS THE AREA. FRONTAL TIMING CONTINUES TO VARY WITHIN THE MODELS...AND STRONG PREFERENCE GOES TO THE VERY CONSISTENT EURO MODEL. GOOD BURST OF LIFT WILL ACCOMPANY THE COLD FRONT...WITH FRONTAL DYNAMICS STACKED UNDERNEATH MID-LEVEL PVA AND LEFT EXIT REGION FORCING. COLD AIR ALOFT REMAINING IN PLACE BEHIND TODAY`S SYSTEM IN COMBINATION WITH H500 TEMPS DROPPING TO ABOUT -35C WITH THE UPPER WAVE...WHICH HAS ARCTIC ORIGINS...WILL CREATE VERY MODERATELY STEEP LOW AND MID-LEVEL LAPSE RATES (FROM SURFACE UP THROUGH 400MB). DEEP LAYER OF INSTABILITY WILL HELP MAXIMIZE RESPONSE FROM FORCING AND MAKE THE BEST OF ONLY MEAGER MOISTURE (SHALLOW LAYER OF MOISTURE POOLING AHEAD OF FRONT WITH SPECIFIC HUMIDITY 3 G/KG AND PW OVERALL ONLY AROUND 0.4 INCHES). PRECIPITATION ASSOCIATED WITH THE FRONT WILL AFFECT THE AREA DURING THE FIRST HALF OF THURSDAY...WITH ADDITIONAL SHOWERS POSSIBLY REDEVELOPING DURING THE LATE AFTERNOON AS LAPSE RATES FURTHER STEEPEN AND SOME MOISTURE LINGERS. PRECIPITATION TYPE IS STILL A LITTLE UNCERTAIN WITH GFS/NAM FORECAST SOUNDINGS STILL HINTING THAT SNOW MAY BE POSSIBLE...BUT GIVEN WARMER EURO PROFILES IN THE PAST TWO MODEL RUNS...WILL KEEP PRECIP TYPE AS RAIN. WOULD ALSO EXPECT TO SEE SOME GRAUPEL FALL AS SHOWERS WILL HAVE A CONVECTIVE ELEMENT TO THEM AND FREEZING LEVELS WILL BE VERY LOW. SURFACE HIGH PRESSURE WILL EXPAND INTO THE AREA FROM THE OHIO VALLEY THURSDAY NIGHT AND FRIDAY BRINGING DRY WEATHER BACK TO THE AREA. LOW PRESSURE TRACKING ACROSS HUDSON BAY WILL DRAW SOME WARMER AIR UP INTO THE REGION ON FRIDAY...ALLOWING TEMPERATURES TO CREEP BACK UP INTO THE UPPER 50S. WEEKEND WILL BE MARKED BY ZONAL FLOW...WITH UPPER RIDGING BUILDING INTO THE GREAT LAKES MONDAY AND TUESDAY IN RESPONSE TO TROUGHING DROPPING DOWN INTO THE NORTHERN ROCKIES. WILL SEE A WARMING TREND DURING THIS STRETCH...WITH MAX TEMPERATURES GRADUALLY WARMING TO AROUND 70. MODELS HAVE BEEN TRYING TO GENERATE CONVECTION JUST ABOUT EVERY AFTERNOON AS LAPSE RATES STEEPEN DURING THE DAY. GIVEN GENERAL LACK OF GOOD MOISTURE ADVECTION (HAVE A FEELING SURFACE TD`S ARE TOO HIGH AS WELL) AND EVENTUAL CAPPING FROM THE RIDGE...ELECTED TO KEEP THE FORECAST DRY AND THUNDERSTORM FREE FOR NOW. && .MARINE... NORTHWEST WINDS IN THE WAKE OF LAST NIGHTS COLD FRONTAL PASSAGE HAS USHERED IN COLDER AIR...LEADING TO UNSTABLE CONDITIONS OVER THE LAKES. SOME GUSTS UP TO 25 KNOTS ARE EXPECTED OVER THE OPEN WATERS OF LAKE HURON. THESE CONDITIONS SHOULD BE SHORT LIVED AS HIGH PRESSURE BUILDS IN FROM THE WEST LATE THIS AFTERNOON AND ALLOWS WINDS AND WAVES TO RELAX. A FAST MOVING LOW PRESSURE SYSTEM WILL THEN TRAVERSE THE REGION ON THURSDAY. THE GRADIENT WILL NOT BE TOO TERRIBLE STRONG...BUT COULD LEAD TO SOME GUSTS UP TO 25 KNOTS OVER LAKES ST CLAIR...ERIE AND THE SOUTHERN BASIN OF LAKE HURON. && .AVIATION...ISSUED 1159 PM EDT TUE APR 23 2013 //DISCUSSION... A COLD FRONT WILL SHIFT THROUGH THE REMAINDER OF THE TERMINALS BETWEEN 06Z-08Z...BRINGING MVFR TO OCCASIONAL IFR CIGS OVERNIGHT. RAIN SHOWERS WILL CONTINUE AS A WAKE OF LOW PRESSURE LIFTS UP ALONG THIS FRONTAL BOUNDARY. AS COLDER AIR WORKS INTO THE AREA IN THE WAKE OF THIS FRONT...SOME SNOWFLAKES MAY MIX IN WITH THE SHOWERS AND WILL INCLUDE THIS MENTION AT KMBS...WHERE IT IS MOST LIKELY TO OCCUR. DRIER AIR WILL WORK INTO THE AREA AS NORTHWEST FLOW DEVELOPS...SO CIGS WILL IMPROVE TO LOWER VFR ON WEDNESDAY...EVEN AS A SECOND WAVE BRINGS ADDITIONAL SHOWERS TO PARTS OF THE AREA INTO MIDDAY. VFR CONDTIONS ARE THEN EXPECTED AS SKIES SCATTERED OUT LATE IN THE DAY. FOR DTW...WINDS WILL SHIFT TO THE NORTHWEST BY 08Z WITH THE PASSAGE OF A COLD FRONT. RAIN SHOWERS WILL PERSIST WITH CIGS LOWERING TO MVFR TO OCCASIONAL IFR ALONG/BEHIND THIS FRONTAL BOUNDARY. //DTW THRESHOLD THREATS... * HIGH CONFIDENCE IN CEILINGS BELOW 5000 FT THROUGH 20Z WEDNESDAY. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...FLOOD WATCH...MIZ047-MIZ048-MIZ049-MIZ053-MIZ054-MIZ055-MIZ060- MIZ061-MIZ062...UNTIL 8 AM WEDNESDAY. LAKE HURON... SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT HURON...UNTIL 5 PM WEDNESDAY. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ SHORT TERM...SC LONG TERM....HLO MARINE.......SC AVIATION.....DG YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
313 AM CDT WED APR 24 2013 .SHORT TERM...(THROUGH LATE THIS AFTERNOON) ISSUED AT 312 AM CDT WED APR 24 2013 (TODAY) STILL DEALING WITH SHOWERS AND ISOLATED THUNDERSTORMS IN THE FAR SOUTHEASTERN PORTIONS OF FORECAST AREA THIS MORNING. BUT THIS ACTIVITY TO CONTINUE TO TAPER OFF. IN THE MEANTIME...DEF ZONE BAND OF VERY LIGHT SNOW/RAIN CONTINUES TO TRACK TO THE EAST SOUTHEAST ACROSS NORTHERN PORTIONS OF FORECAST AREA EARLY THIS MORNING. EXPECT THE LIGHT SNOW/RAIN TO BE BRIEF AS IT SLIDES THROUGH REGION THIS MORNING...COMING TO AN END BY NOON AS SECONDARY SHORTWAVE LIFTS OUT. BECAUSE OF THE WARM GROUND AND LIGHT NATURE OF THE PCPN...DO NOT EXPECT ANY ACCUMULATION WITH THIS DEF ZONE PCPN. OTHERWISE... BACK EDGE OF CLOUDS WITH THIS SYSTEM ARE ALREADY MOVING INTO NORTHWESTERN MO...SO TO CONTINUE MAKING STEADY PROGRESS AS WELL WITH CLEARING CONDITIONS REACHING METRO AREA BY EARLY THIS AFTERNOON. HIGHS WILL BE ABOUT 15 DEGREES BELOW NORMAL...IN THE LOW TO MID 50S. WINDS TO PERSIST FROM THE NORTHWEST AROUND 10 MPH. BYRD TRUETT .LONG TERM...(TONIGHT THROUGH TUESDAY) ISSUED AT 312 AM CDT WED APR 24 2013 (TONIGHT-THURSDAY) 00Z RUNS CONTINE TO ADVERTISE A SECONDARY SHORTWAVE DIPPING INTO LONG WAVE TROF OVER THE CENTRAL U.S. TONIGHT. MAIN DYNAMICS WITH THIS SYSTEM WILL BE TO OUR N...OVER THE UPPER MISSISSIPPI VALLEY AND INTO THE UPPER GREAT LAKES...SO NOT FORESEEING MUCH IN THE WAY OF PRECIP IN OUR AREA. COLD FRONT ASSOCIATED WITH THIS FEATURE WILL PRODUCE A VERY BRIEF REINFORCING SHOT OF COLD AIR ACROSS NORTHERN PARTS OF THE FA LATE TONIGHT AND EARLY THURSDAY. EARLIER THERE WAS SOME CONCERN THAT FROST MAY BE A PROBLEM WITH THE EXPANSIVE SURFACE RIDGE SOUTH OF THE COLD FRONT...BUT IT NOW APPEARS THAT COLD FRONT WILL PENETRATE FAR ENOUGH SOUTH THAT THE MIXING ASSOCIATED WITH IT SHOULD PREVENT FROST IN ALL BUT PERHAPS THE MOST SHELTERED AREAS IN S SECTIONS OF THE CWA. WILL KEEP SOME MENTION OF FROST GOING IN OUR FAR SOUTH...BUT NO HEADLINE ATTM. UA PATTERN OVER THE REGION QUICKLY TRANSITIONS TO A ZONAL FLOW REGIME ON THURSAY IN THE WAKE OF THE UPPER GREAT LAKES SHORTWAVE. THIS SHOULD ALLOW FOR SOME MODERATION TEMPS DURING THE DAY...ALTHOUGH HIGHS WILL STILL REMAIN NEARLY 10 DEGREES BELOW NORMAL. (FRIDAY-SATURDAY) MEDIUM RANGE SOLUTIONS ARE STILL BRINGING REMNANTS OF SW CUTOFF LOW INTO THE AREA ON FRIDAY AND FRIDAY NIGHT. GFS IS THE ODD-MODEL OUT WITH A MORE NWD PLACEMENT OF FEATURES AND QPF...SO HAVE BASED FORECAST ON THE MORE SOUTHWARD CONSENSUS SOLUTIONS WHICH DOVETAILS NICELY WITH GOING FORECASTS. PRECIP MAY HAVE A TOUGH TIME REACHING N SECTIONS OF OUR CWA AND HAVE TRIMMED POPS BACK IN THE N A BIT ON FRIDAY...BUT BROAD AREA OF OVERRUNNING SHOULD MAKE FOR A RAINY AND COOL DAY OVER MUCH OF S MO. SOME OF THIS PRECIP SHOULD CERTAINLY CONTINUE INTO FRIDAY NIGHT...WITH A THREAT OF LIGHT RAIN LINGERING OVER S SECTIONS OF THE CWA INTO SATURDAY AS LINGERING REMNANTS OF SYSTEM BEGIN TO SAG SOUTH. (SUNDAY-WEDNESDAY) HEIGHTS ARE FORECAST TO BUILD OVER AREA AS UPPER TROF SLOWLY DEEPENS OVER THE NORTHERN ROCKIES. THIS SHOULD CERTAINLY LEAD TO A WARMUP DURING THE EARLY PART OF THE NEW WEEK WITH TEMPERATURES FINALLY REBOUNDING TO NEAR..AND PERHAPS ABOVE...AVERAGE LEVELS. DETAILS IN SYNOPTIC FEATURES GET FAIRLY MUDDLED BY MID WEEK AS THE OPERATIONAL GFS IS MUCH MORE PROGRESSIVE WITH THE UPPER TROF THAN THE ECMWF. DUE TO THE DISCREPENCY FOR NOW HAVE KEPT POPS BELOW CHANCE CATEGORY ON WEDNESDAY. TRUETT && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1132 PM CDT TUE APR 23 2013 RAIN SHOWERS CONTINUE TO PUSH SLOWLY OFF TO THE EAST LATE THIS EVENING WELL BEHIND COLD FRONT WHICH PASSED THROUGH THE AREA TODAY. SHOWERS SHOULD PUSH OUT OF KSUS AND KSTL BY 0600 UTC BUT STILL AFFECT KCPS THROUGH APPROXIMATELY 0900 UTC. FUTHER TO THE NORTHWEST...A NARROW BAND OF RAIN/SNOW MIX IS SWEEPING TO THE EAST-SOUTHEAST AND HAVE A TEMPO GROUP IN AT KCOU AND KUIN OVERNIGHT TO ACCOUNT FOR A 2-3 HOUR PERIOD OF LIGHT MIXED PRECIPITATION ACCOMPANIED BY MVFR CEILINGS. NOT SURE HOW WELL CURRENT BAND WILL HOLD TOGETHER NOR THE PYTPE ACROSS METRO TAF SITES IF IT DOES INDEED ARRIVE...SO FOR NOW LEFT OUT OF TAFS. CEILINGS HAVE ACTUALLY IMPROVED THE PAST SEVERAL HOURS AND ONLY REAL GUIDANCE WHICH HAS LATCHED ON IS RAP SO TRIED TO FOLLOW ITS TRENDS FAIRLY CLOSELY. KCOU AND KUIN HAVE ALREADY IMPROVED TO VFR AND BELIEVE THEY WILL STAY THAT WAY WITH THE EXCEPTION OF WITHIN THE AFOREMENTIONED BAND OF RAIN/SNOW. FOR THE METRO TAFS...MVFR CEILINGS WILL LIKELY PREVAIL OVERNIGHT BEFORE IMPROVING TO VFR EARLY TOMORROW MORNING THOUGH THIS MAY STILL YET BE TOO SLOW. WINDS WILL GRADUALLY BACK THROUGH THE VALID TAF PERIOD AS SFC HIGH PRESSURE SLIDES INTO THE CENTER OF THE COUNTRY. SPECIFICS FOR KSTL... RAIN SHOWERS CONTINUE TO PUSH SLOWLY OFF TO THE EAST LATE THIS EVENING WELL BEHIND COLD FRONT WHICH PASSED THROUGH THE AREA TODAY. SHOWERS SHOULD PUSH OUT OF KSTL BY 0600 UTC. FUTHER TO THE NORTHWEST...A NARROW BAND OF RAIN/SNOW MIX IS SWEEPING TO THE EAST-SOUTHEAST. NOT SURE HOW WELL CURRENT BAND WILL HOLD TOGETHER NOR THE PYTPE FOR LAMBERT IF IT DOES INDEED ARRIVE...SO FOR NOW LEFT OUT OF TAF DUE TO LOW CONFIDENCE. CEILINGS HAVE ACTUALLY IMPROVED THE PAST SEVERAL HOURS TO THE NORTH AND WEST AND ONLY REAL GUIDANCE WHICH HAS LATCHED ON IS RAP SO TRIED TO FOLLOW ITS TRENDS FAIRLY CLOSELY. THAT BEING SAID...MVFR CEILINGS WILL PROBABLY PREVAIL OVERNIGHT BEFORE IMPROVING TO VFR EARLY TOMORROW MORNING THOUGH THIS MAY STILL YET BE TOO SLOW. WINDS WILL GRADUALLY BACK THROUGH THE VALID TAF PERIOD AS SFC HIGH PRESSURE SLIDES INTO THE CENTER OF THE COUNTRY. GOSSELIN && .LSX WATCHES/WARNINGS/ADVISORIES... MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1143 PM CDT TUE APR 23 2013 .SHORT TERM...(THROUGH LATE TONIGHT) ISSUED AT 325 PM CDT TUE APR 23 2013 A STRONG CDFNT CONTINUES TO PUSH THROUGH THE CWA THIS AFTN ALTHOUGH ITS SEWD PROGRESS HAS BEEN TEMPORARILY STALLED BY AN AREA OF LOW PRESSURE IN SWRN MO WHICH IS RIDING UP THE BDRY TOWARDS IL. WINDS WILL ABRUPTLY BECOME NWLY TO NLY AFTER FROPA AND TEMPERATURES WILL QUICKLY FALL INTO THE 40S AND UPPER 30S. ON-AND-OFF SHRA WILL CONTINUE INTO THE EARLY EVENING HOURS FOLLOWED BY ANOTHER PD OF STEADIER PCPN ONCE A DEFORMATION ZONE REDEVELOPS ACROSS THE AREA. MODEL FCSTS OF H7-H6 FRONTOGENESIS SEEM WELL CORRELATED WITH THE LARGE DEFORMATION ZONE THAT DVLPD OVER KS AND NWRN MO EARLIER TODAY THEREFORE GENERALLY FOLLOWED THIS GUIDANCE IN PLACING HIGHEST PCPN CHCS FOR TONIGHT. THE AIR MASS BEHIND THE FRONT IS COLD ENOUGH THAT SOME LIGHT SNOW MAY MIX IN WITH THE RAIN LATER TONIGHT HOWEVER NO ACCUMULATIONS ARE EXPECTED DUE TO THE WARM GROUND. KANOFSKY .LONG TERM...(WEDNESDAY THROUGH NEXT TUESDAY) ISSUED AT 325 PM CDT TUE APR 23 2013 (WEDNESDAY - WEDNESDAY NIGHT) UPPER LEVEL LONGWAVE TROF OVER THE CNTRL-ERN CONUS WILL REMAIN IN PLACE DURING THIS PERIOD...A PATTERN THAT ALLUDES TO CONTINUED COOL. MODELS HAVE CERTAINLY COME MORE ON BOARD AND IN BETTER CONSENSUS DURING THE PAST 12-24HRS WITH REGARDS TO DEVELOPMENT OF A SECOND DEFORMATION ZONE WITH OUR CURRENT SYSTEM THEREFORE DELAYING THE FINAL EXIT OF THE PCPN INTO WEDNESDAY MORNING. A MORE CYCLONICLY CURVED H300 JET...A STRONG FINAL VORT MAX AT THE BASE OF THE TROF...WITH REASONABLY STRONG FRONTOGENESIS AND JUST ENOUGH MOISTURE LEFT THANKS TO A SLOWER PROGRESSING H850 FRONT ALOFT ARE THE REASONS FOR THIS SECONDARY AREA. WHILE ALL OF THIS IS EXPECTED TO BE IN PLACE AND WORTHY OF LIKELY POPS AT 12Z/WED...SUDDEN SURGE OF DRY AIR AND LOSS OF FORCING BY 18Z/WED WILL WRAP UP PCPN QUICKLY WED MRNG. PCPN TYPES STILL LOOK LIKE A RAIN-SNOW MIX ON THE NWRN EDGE...INCL THRU THE STL METRO AREA...BUT SFC TEMPS WILL BE ENOUGH ON THE FENCE TO FAVOR ALL RAIN SHORTLY AFTER 12Z. NO SNOW ACCUM IS EXPECTED. MOS TEMPS FOR MAXES LOOK GOOD ON WEDNESDAY...WHILE SFC RIDGE AXIS DROPPING INTO SRN MO AND FAR SRN IL FOR WEDNESDAY NIGHT WILL LEAD TO A PREFERENCE FOR THE WARMER MAV NUMBERS FOR MIN TEMPS OVER NRN MO AND CNTRL IL...TRENDING TOWARDS THE COLDER MET MOS IN SERN MO. MIN TEMPS IN SERN MO SHOULD BE CLOSE TO FREEZING...BUT NOT ENOUGH BELOW TO WARRANT FREEZE WARNING...BUT COULD VERY WELL SEE A FROST ADVISORY ACROSS A LARGE PART OF THE AREA S OF I-70...PERHAPS FURTHER N AS WELL...WITH CLEAR SKIES AND LIGHT WINDS EXPECTED. WILL MAINTAIN PATCHY FROST IN THESE AREAS FOR NOW. ELSEWHERE FURTHER N...TEMPS LOOK TOO MARGINAL AND SFC WNDS A BIT TOO STRONG FOR FROST. (THURSDAY - NEXT TUESDAY) UPPER LEVEL LONGWAVE TROF IS ANTICIPATED TO RETREAT NWD LATE THIS WEEK AND EVENTUALLY GET REPLACED EARLY NEXT WEEK BY A LONGWAVE RIDGE OVER ERN NOAM WITH A TROF IN THE W. THIS IS QUITE A PATTERN SHIFT TO WHAT WE HAD BEEN SEEING...AND THIS SHOULD GIVE US ABOVE AVERAGE TEMPS FROM LATE THIS WEEKEND THRU THE END OF THE FCST...BUT THE RIDGING SHOULD ALSO BE SUFFICIENTLY STRONG TO DEFLECT SYSTEMS TO OUR N KEEPING PCPN CHCS LO. MODELS CONTINUE TO FORM A CONSENSUS ON TIMING OF A SHORTWAVE THRU LATE IN THE WEEK OUT OF THE SWRN CONUS...A FORMER CUTOFF LO REJOINING THE MAIN FLOW...WITH THE ECMWF SPEEDING UP TO A TIMING CLOSER TO THE GFS FROM 24HRS AGO. DECENT RAIN CHCS WILL THUS MAKE A RETURN TO THE REGION DURING THE FRIDAY-FRIDAY NIGHT TIMEFRAME WITH PERHAPS SOMETHING LINGERING INTO SATURDAY. THUNDER IS LOOKING LIKE LESS AND LESS OF A POSSIBILITY WITH EACH RUN...KEEPING THE MAIN SYSTEM TO OUR S AND SEVERELY LIMITING THE BETTER SHOWALTER/MUCAPE VALUES TO THE FAR SRN FA. WITH THE LONGWAVE RIDGE BUILDING OVER THE ERN CONUS...SHOULD SEE ABOUT THE HIGHEST HEIGHT VALUES OF THE SEASON AND A PERIOD OF DRY WX. STILL SOME DISAGREEMENT ON WHETHER OR NOT A SFC CDFNT WILL COME DOWN ON TUESDAY...BUT WITH THAT KIND OF MID LEVEL FLOW AND THE GFS ALREADY BACKING OFF ON THE TIMING BY 12HRS...FEEL IT WILL PROBABLY NOT HAPPEN AS QUICKLY AS IT SAYS. TES && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1132 PM CDT TUE APR 23 2013 RAIN SHOWERS CONTINUE TO PUSH SLOWLY OFF TO THE EAST LATE THIS EVENING WELL BEHIND COLD FRONT WHICH PASSED THROUGH THE AREA TODAY. SHOWERS SHOULD PUSH OUT OF KSUS AND KSTL BY 0600 UTC BUT STILL AFFECT KCPS THROUGH APPROXIMATELY 0900 UTC. FUTHER TO THE NORTHWEST...A NARROW BAND OF RAIN/SNOW MIX IS SWEEPING TO THE EAST-SOUTHEAST AND HAVE A TEMPO GROUP IN AT KCOU AND KUIN OVERNIGHT TO ACCOUNT FOR A 2-3 HOUR PERIOD OF LIGHT MIXED PRECIPITATION ACCOMPANIED BY MVFR CEILINGS. NOT SURE HOW WELL CURRENT BAND WILL HOLD TOGETHER NOR THE PYTPE ACROSS METRO TAF SITES IF IT DOES INDEED ARRIVE...SO FOR NOW LEFT OUT OF TAFS. CEILINGS HAVE ACTUALLY IMPROVED THE PAST SEVERAL HOURS AND ONLY REAL GUIDANCE WHICH HAS LATCHED ON IS RAP SO TRIED TO FOLLOW ITS TRENDS FAIRLY CLOSELY. KCOU AND KUIN HAVE ALREADY IMPROVED TO VFR AND BELIEVE THEY WILL STAY THAT WAY WITH THE EXCEPTION OF WITHIN THE AFOREMENTIONED BAND OF RAIN/SNOW. FOR THE METRO TAFS...MVFR CEILINGS WILL LIKELY PREVAIL OVERNIGHT BEFORE IMPROVING TO VFR EARLY TOMORROW MORNING THOUGH THIS MAY STILL YET BE TOO SLOW. WINDS WILL GRADUALLY BACK THROUGH THE VALID TAF PERIOD AS SFC HIGH PRESSURE SLIDES INTO THE CENTER OF THE COUNTRY. SPECIFICS FOR KSTL... RAIN SHOWERS CONTINUE TO PUSH SLOWLY OFF TO THE EAST LATE THIS EVENING WELL BEHIND COLD FRONT WHICH PASSED THROUGH THE AREA TODAY. SHOWERS SHOULD PUSH OUT OF KSTL BY 0600 UTC. FUTHER TO THE NORTHWEST...A NARROW BAND OF RAIN/SNOW MIX IS SWEEPING TO THE EAST-SOUTHEAST. NOT SURE HOW WELL CURRENT BAND WILL HOLD TOGETHER NOR THE PYTPE FOR LAMBERT IF IT DOES INDEED ARRIVE...SO FOR NOW LEFT OUT OF TAF DUE TO LOW CONFIDENCE. CEILINGS HAVE ACTUALLY IMPROVED THE PAST SEVERAL HOURS TO THE NORTH AND WEST AND ONLY REAL GUIDANCE WHICH HAS LATCHED ON IS RAP SO TRIED TO FOLLOW ITS TRENDS FAIRLY CLOSELY. THAT BEING SAID...MVFR CEILINGS WILL PROBABLY PREVAIL OVERNIGHT BEFORE IMPROVING TO VFR EARLY TOMORROW MORNING THOUGH THIS MAY STILL YET BE TOO SLOW. WINDS WILL GRADUALLY BACK THROUGH THE VALID TAF PERIOD AS SFC HIGH PRESSURE SLIDES INTO THE CENTER OF THE COUNTRY. GOSSELIN && .LSX WATCHES/WARNINGS/ADVISORIES... MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
153 PM EDT WED APR 24 2013 .SYNOPSIS... SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL OCCUR LATE TODAY AND INTO THIS EVENING AS A STRONG COLD FRONT PASSES THROUGH THE AREA. BEHIND THIS FEATURE...DRY CONDITIONS ARE EXPECTED ON THURSDAY WITH THE NEXT ROUND OF SHOWERS POSSIBLE THURSDAY NIGHT AND EARLY FRIDAY AS ANOTHER WEAK WAVE WILL PASSES OVERHEAD. FAIR AND PLEASANT CONDITIONS ARE THEN EXPECTED FOR THE WEEKEND AS STRONG HIGH PRESSURE BUILDS INTO THE AREA. && .NEAR TERM /THROUGH TONIGHT/... 1115 AM UPDATE... A WEAK WARM FRONT MOVING THROUGH THE REGION THIS MORNING HAS PRODUCED A FAIR AMOUNT OF CLOUD COVER ALONG WITH SPRINKLES OVER CENTRAL NEW YORK AND THE NORTHERN TIER OF PA. IT HAS ALSO KEPT SFC TEMPS LOWER THAN EXPECTED WITH MAXES NOW RANGING FROM THE MID/UPPER 60S. COLD FRONT HAS JUST CROSSED CLEVELAND WITH WIDESPREAD SHOWERS JUST AHEAD AND MAINLY BEHIND BOUNDARY. LATEST MODEL GUIDANCE CONTINUES TO SHOW SEVERAL HUNDRED J/KG OF CAPE LATER THIS AFTERNOON PRIMARILY ACROSS THE SOUTHERN TIER OF NYS AND NE PA. WITH THE AMOUNT OF CLOUD COVER IT WILL BE INTERESTING TO SEE IF THIS MUCH CAPE IS REALIZED. MODEL SOUNDINGS DO SHOW PRETTY GOOD MID LEVEL LAPSE RATES SO IF ENOUGH FRONTAL LIFT IS GENERATED THIS INSTABILITY COULD BE TAPPED. IF ENOUGH INSTABILITY IS REALIZED THE CURRENT WIND FIELD AND SHEAR VALUES WOULD SUPPORT A FEW STRONGER CELLS WITH THE POTENTIAL FOR A FEW SEVERE THUNDERSTORMS. CURRENT FORECAST IN GOOD SHAPE WILL CONTINUE WITH CATEGORICAL POPS FOR SHOWERS DURING FROPA AND CHC POPS FOR THUNDERSTORMS. 630 AM UPDATE... QUICK UPDATE TO ACCOUNT FOR LATEST RADAR TRENDS TO OUR WEST. REGIONAL RADARS NOW SHOWING AN INITIAL BAND OF LGT RAIN SHWRS WORKING INTO WESTERN NY THIS HR...WHICH APPEARS TO BE THE RESULT OF WEAK ISENTROPIC ASCENT ALONG/NORTH OF DIFFUSE WARM FRONT. THAT SAID...HAVE UPDATED GRIDS TO BRING IN RAIN A FEW HRS EARLIER ACROSS THE WESTERN AND NORTHERN ZONES. NO OTHER CHANGES NEEDED AT THE PRESENT TIME. PREVIOUS NEAR TERM DISCUSSION... A CHALLENGING FCST TO SAY THE LEAST TODAY AS A STRONG COLD FRONT WILL PLOW THROUGH THE REGION DURING THE LATE AFTERNOON AND EARLY EVENING HRS. THE MAIN DIFFICULTIES ARE TWOFOLD WITH THE FIRST BEING THE DEGREE OF WARMING PROCEEDING THE FRONT...AND THE SECOND CONCERNING SEVERE WX POTENTIAL AS THE FRONT BARRELS THROUGH THE REGION. FIRST THINGS FIRST HOWEVER AND WE SHOULD PROBABLY START WITH A GENERAL SYNOPTIC OVERVIEW. EARLY MORNING WATER VAPOR CLEARLY SHOWING A DEEP TROUGH OF LOW PRESSURE DIGGING ACROSS THE SOUTHERN PLAINS THIS MORNING WITH BROAD CYCLONIC FLOW PREVAILING OVER THE NATION/S MIDSECTION. ACROSS OUR REGION...WEAK UPPER RIDGING THAT BROUGHT SUCH NICE WX TO OUR AREA YESTERDAY NOW DEPARTING TO OUR EAST AS UPPER TROUGH AND ASSOCIATED DEFORMATION AXIS WITH THE WESTERN ATLANTIC COASTAL LOW WORK OFF THE NEW ENGLAND COAST. WITH TIME TODAY...COLD FRONT ASSOCIATED WITH THE CENTRAL US TROUGH WILL ADVANCE EAST OVER OUR REGION BY THIS AFTERNOON BRINGING WITH IT A PERIOD OF SHWRS AND STORMS TO MUCH OF OUR AREA. AS FOR THE SEVERE WX POTENTIAL...MODELS REMAIN ALL OVER THE PLACE WITH RESPECT TO THE DEGREE OF DESTABILIZATION THAT WILL OCCUR PRIOR TO FROPA LATER TODAY. THE NAM REMAINS THE MOST UNSTABLE SOLUTION THIS MORNING WITH AWIPS PLAN VIEW MAPS SHOWING A NARROW CORRIDOR OF MLCAPE VALUES RANGING FROM 400-500 J/KG IMMEDIATELY PROCEEDING THE FRONT MAINLY WEST OF THE I-81 CORRIDOR. THIS IS PERPLEXING TO SOME DEGREE AS CORRESPONDING NAM BUFKIT SOUNDINGS FOR ELM AND OTHER WESTERN FCST POINT LOCATIONS ADVERTISE MUCH LOWER VALUES. THE GFS SEEMS TO AGREE WITH THE WEAKER NAM BUFKIT SOLUTIONS...AS DOES THE LATEST RUC AND LOCALLY RUN WRF MODELS. AS FOR THE KINEMATICS...WIND FIELDS ALOFT REMAIN IMPRESSIVELY STRONG WITH 0-6 KM BULK SHEAR VECTORS RANGING FROM 40 TO 50 KTS ACROSS THE REGION WHILE 0-3 KM BULK SHEAR VALUES ARE JUST AS HIGH. THIS SUGGESTS THAT IF SEVERE WX WERE TO DEVELOP...DAMAGING WIND GUSTS WOULD BE THE BIGGEST THREATS IF ANY DEVELOPING CONVECTION WERE TO MORPH INTO A WELL-DEFINED SQUALL LINE OR SHORT BOWING SEGMENTS. THIS AGREES WELL WITH LOCAL SEVERE WX CHECKLIST WHICH SUGGEST A SIGNIFICANT COOL SEASON WIND EVENT IS POSSIBLE HOWEVER ITS HARD TO GET BY LATEST MODEL TRENDS OF VERY MODEST DESTABILIZATION. CONSIDERING THE AMOUNT OF CLOUD COVER THAT WILL LIKELY BEGIN MOVING OVERHEAD THIS MORNING COUPLED WITH THE FACT THAT RETURN FLOW MOISTURE WILL BE MEAGER AT BEST (AFTERNOON DEWPOINT TEMPS ONLY CLIMBING INTO THE MIDDLE TO UPPER 40S)...WE/RE INCLINED TO BELIEVE THAT SEVERE WX POTENTIAL WILL BE FAIRLY LIMITED. THIS AGREES WELL WITH THE LATEST SPC DAY 1 OUTLOOK WHICH ONLY ADVERTISES GENERAL THUNDER MENTION ACROSS OUR REGION ("SEE TEXT" TO OUR SOUTHWEST). ALTHOUGH WE TOTALLY CANNOT RULE OUT SEVERE WX LATER TODAY...WE DO NOT THINK THAT THE FCST REGION WILL BE DEALING WITH A WIDESPREAD SEVERE WX EVENT AT THIS TIME. NOW TO THE NEXT ISSUE...THE HIGH TEMP FCST FOR TODAY. UPSTREAM OBS FROM THE UPPER OHIO VLY SHOW TEMPS IN THE LOWER 60S AS CLOSE AS CLEVELAND EARLY THIS MORNING. CONSIDERING THIS AIR WILL TRAVEL EAST OVER OUR REGION...WE/RE INCLINED TO BELIEVE TEMPS WILL WARM INTO THE UPPER 60S TO LOWER 70S AHEAD OF THE FRONT TODAY. ONLY ITEM OF CONCERN IS THE LATEST SATELLITE TRENDS WHICH SHOW ENHANCED CLOUD COVER APPROACHING FROM NORTHERN OHIO THIS MORNING. DESPITE THIS HOWEVER...DEGREE OF THERMAL ADVECTION WILL LIKELY BE ENOUGH TO OVERCOME LIMITED COOLING ASSOCIATED WITH INCREASING CLOUDS ALOFT. BY TONIGHT...COLD FRONT TO EXIT OFF TO THE EAST WITH TIME BETWEEN 00 AND 06Z. RAIN SHOULD GRADUALLY COME TO AN END WITH TIME WITH STRONG COLD AIR ADVECTION EXPECTED IN ITS WAKE. AS A RESULT...TEMPS WILL DROP INTO THE LOWER TO MIDDLE 30S ACROSS MUCH OF THE REGION WITH GUSTY WINDS EXPECTED THROUGH A GOOD PORTION OF THE OVERNIGHT HRS. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... COOLER TEMPS EXPECTED BOTH THU AND FRI AS COOL HIGH PRESSURE BUILDS IN FOLLOWING FROPA LATER TONIGHT. WITH H85 TEMPS QUICKLY FALLING TO NEAR ZERO CELSIUS...HIGH TEMPS ON THU ONLY LOOK TO WARM INTO THE LOWER TO MIDDLE 50S AT BEST. SLIGHTLY WARMER TEMPS EXPECTED ON FRI AS HIGH PRESSURE ADVANCES TO THE EAST WITH UPPER 50S TO LOWER 60S AGAIN POSSIBLE. WEAK UPPER WAVE WILL PASS ACROSS THE REGION THU NGT/EARLY FRI BRINGING THE NEXT ROUND OF SHWRS TO THE AREA. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... 200 PM UPDATE... NO BIG CHANGES TO THE EXTENDED. A LARGE AREA OF HIGH PRESSURE ANCHORED TO OUR SOUTHEAST WILL PROVIDE US WITH A WARM PERIOD WITH MAINLY DRY WEATHER. POTENTIAL FLY IN THE OINTMENT REMAINS A NORTH/SOUTH AXIS OF MOISTURE NEAR OR JUST WEST OF OUR AREA. THE GFS CONTINUES TO BE THE MOST AGGRESSIVE WITH THIS MOISTURE WHILE THE EURO HINTS AT IT BUT IS MUCH DRIER. WILL MAINTAIN CONSISTENCY AND LEAVE THE FORECAST DRY. BASED ON THE LOCATION OF THE HIGH IT DOES APPEAR MOISTURE IN THE RETURN FLOW AROUND THE HIGH WOULD STAY TO OUR SOUTHWEST. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... VFR CONDS NEXT FEW HOURS AHD OF A COLD FNT APRCHG THE AREA FROM WEST. FNT WILL BRING SHWRS AND ISLTD TRW STARTING ARND 21Z AND CONTG THRU ARND 01Z. MVFR CIGS AND VSBYS WITH THE SHWRS...ALONG WITH GUSTY WINDS. BHD THE FNT...CAA WILL BRING MVFR CIGS ALONG WITH SPOTTY MVFR VSBYS IN SHWRS ESPECIALLY NY TERMINALS. DRIER AIR WELL BHD THE FNT WILL RETURN SOME LOCATIONS TO VFR BEFORE THE END OF THE TAF PD AND THIS WILL ESPECIALLY TRUE ACROSS THE SOUTHERN TERMINALS BY 06Z BUT NOT UNTIL CLOSER TO 12Z UP NORTH. VFR ON THURSDAY. SOUTHWEST WINDS 10 KTS WITH GUSTS TO 25 THROUGH 0Z. WINDS VEERING INTO THE WEST AND NORTHWEST THIS EVENING. GUSTS TO 25 KTS STILL POSSIBLE THROUGH EARLY EVENING THEN NORTHWEST WINDS 5 TO 10 KTS THROUGH THURSDAY. OUTLOOK... THU THRU MON...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...CMG/RRM NEAR TERM...CMG/RRM SHORT TERM...CMG LONG TERM...HEDEN AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1139 AM EDT WED APR 24 2013 .SYNOPSIS... SHOWERS ALONG WITH A FEW THUNDERSTORMS WILL OCCUR LATE TODAY AND INTO THIS EVENING AS A STRONG COLD FRONT PASSES THROUGH THE AREA. BEHIND THIS FEATURE...DRY CONDITIONS ARE EXPECTED ON THURSDAY WITH THE NEXT ROUND OF SHOWERS POSSIBLE THURSDAY NIGHT AND EARLY FRIDAY AS ANOTHER WEAK WAVE WILL PASSES OVERHEAD. FAIR AND PLEASANT CONDITIONS ARE THEN EXPECTED FOR THE WEEKEND AS STRONG HIGH PRESSURE BUILDS INTO THE AREA. && .NEAR TERM /THROUGH TONIGHT/... 1115 AM UPDATE... A WEAK WARM FRONT MOVING THROUGH THE REGION THIS MORNING HAS PRODUCED A FAIR AMOUNT OF CLOUD COVER ALONG WITH SPRINKLES OVER CENTRAL NEW YORK AND THE NORTHERN TIER OF PA. IT HAS ALSO KEPT SFC TEMPS LOWER THAN EXPECTED WITH MAXES NOW RANGING FROM THE MID/UPPER 60S. COLD FRONT HAS JUST CROSSED CLEVELAND WITH WIDESPREAD SHOWERS JUST AHEAD AND MAINLY BEHIND BOUNDARY. LATEST MODEL GUIDANCE CONTINUES TO SHOW SEVERAL HUNDRED J/KG OF CAPE LATER THIS AFTERNOON PRIMARILY ACROSS THE SOUTHERN TIER OF NYS AND NE PA. WITH THE AMOUNT OF CLOUD COVER IT WILL BE INTERESTING TO SEE IF THIS MUCH CAPE IS REALIZED. MODEL SOUNDINGS DO SHOW PRETTY GOOD MID LEVEL LAPSE RATES SO IF ENOUGH FRONTAL LIFT IS GENERATED THIS INSTABILITY COULD BE TAPPED. IF ENOUGH INSTABILITY IS REALIZED THE CURRENT WIND FIELD AND SHEAR VALUES WOULD SUPPORT A FEW STRONGER CELLS WITH THE POTENTIAL FOR A FEW SEVERE THUNDERSTORMS. CURRENT FORECAST IN GOOD SHAPE WILL CONTINUE WITH CATEGORICAL POPS FOR SHOWERS DURING FROPA AND CHC POPS FOR THUNDERSTORMS. 630 AM UPDATE... QUICK UPDATE TO ACCOUNT FOR LATEST RADAR TRENDS TO OUR WEST. REGIONAL RADARS NOW SHOWING AN INITIAL BAND OF LGT RAIN SHWRS WORKING INTO WESTERN NY THIS HR...WHICH APPEARS TO BE THE RESULT OF WEAK ISENTROPIC ASCENT ALONG/NORTH OF DIFFUSE WARM FRONT. THAT SAID...HAVE UPDATED GRIDS TO BRING IN RAIN A FEW HRS EARLIER ACROSS THE WESTERN AND NORTHERN ZONES. NO OTHER CHANGES NEEDED AT THE PRESENT TIME. PREVIOUS NEAR TERM DISCUSSION... A CHALLENGING FCST TO SAY THE LEAST TODAY AS A STRONG COLD FRONT WILL PLOW THROUGH THE REGION DURING THE LATE AFTERNOON AND EARLY EVENING HRS. THE MAIN DIFFICULTIES ARE TWOFOLD WITH THE FIRST BEING THE DEGREE OF WARMING PROCEEDING THE FRONT...AND THE SECOND CONCERNING SEVERE WX POTENTIAL AS THE FRONT BARRELS THROUGH THE REGION. FIRST THINGS FIRST HOWEVER AND WE SHOULD PROBABLY START WITH A GENERAL SYNOPTIC OVERVIEW. EARLY MORNING WATER VAPOR CLEARLY SHOWING A DEEP TROUGH OF LOW PRESSURE DIGGING ACROSS THE SOUTHERN PLAINS THIS MORNING WITH BROAD CYCLONIC FLOW PREVAILING OVER THE NATION/S MIDSECTION. ACROSS OUR REGION...WEAK UPPER RIDGING THAT BROUGHT SUCH NICE WX TO OUR AREA YESTERDAY NOW DEPARTING TO OUR EAST AS UPPER TROUGH AND ASSOCIATED DEFORMATION AXIS WITH THE WESTERN ATLANTIC COASTAL LOW WORK OFF THE NEW ENGLAND COAST. WITH TIME TODAY...COLD FRONT ASSOCIATED WITH THE CENTRAL US TROUGH WILL ADVANCE EAST OVER OUR REGION BY THIS AFTERNOON BRINGING WITH IT A PERIOD OF SHWRS AND STORMS TO MUCH OF OUR AREA. AS FOR THE SEVERE WX POTENTIAL...MODELS REMAIN ALL OVER THE PLACE WITH RESPECT TO THE DEGREE OF DESTABILIZATION THAT WILL OCCUR PRIOR TO FROPA LATER TODAY. THE NAM REMAINS THE MOST UNSTABLE SOLUTION THIS MORNING WITH AWIPS PLAN VIEW MAPS SHOWING A NARROW CORRIDOR OF MLCAPE VALUES RANGING FROM 400-500 J/KG IMMEDIATELY PROCEEDING THE FRONT MAINLY WEST OF THE I-81 CORRIDOR. THIS IS PERPLEXING TO SOME DEGREE AS CORRESPONDING NAM BUFKIT SOUNDINGS FOR ELM AND OTHER WESTERN FCST POINT LOCATIONS ADVERTISE MUCH LOWER VALUES. THE GFS SEEMS TO AGREE WITH THE WEAKER NAM BUFKIT SOLUTIONS...AS DOES THE LATEST RUC AND LOCALLY RUN WRF MODELS. AS FOR THE KINEMATICS...WIND FIELDS ALOFT REMAIN IMPRESSIVELY STRONG WITH 0-6 KM BULK SHEAR VECTORS RANGING FROM 40 TO 50 KTS ACROSS THE REGION WHILE 0-3 KM BULK SHEAR VALUES ARE JUST AS HIGH. THIS SUGGESTS THAT IF SEVERE WX WERE TO DEVELOP...DAMAGING WIND GUSTS WOULD BE THE BIGGEST THREATS IF ANY DEVELOPING CONVECTION WERE TO MORPH INTO A WELL-DEFINED SQUALL LINE OR SHORT BOWING SEGMENTS. THIS AGREES WELL WITH LOCAL SEVERE WX CHECKLIST WHICH SUGGEST A SIGNIFICANT COOL SEASON WIND EVENT IS POSSIBLE HOWEVER ITS HARD TO GET BY LATEST MODEL TRENDS OF VERY MODEST DESTABILIZATION. CONSIDERING THE AMOUNT OF CLOUD COVER THAT WILL LIKELY BEGIN MOVING OVERHEAD THIS MORNING COUPLED WITH THE FACT THAT RETURN FLOW MOISTURE WILL BE MEAGER AT BEST (AFTERNOON DEWPOINT TEMPS ONLY CLIMBING INTO THE MIDDLE TO UPPER 40S)...WE/RE INCLINED TO BELIEVE THAT SEVERE WX POTENTIAL WILL BE FAIRLY LIMITED. THIS AGREES WELL WITH THE LATEST SPC DAY 1 OUTLOOK WHICH ONLY ADVERTISES GENERAL THUNDER MENTION ACROSS OUR REGION ("SEE TEXT" TO OUR SOUTHWEST). ALTHOUGH WE TOTALLY CANNOT RULE OUT SEVERE WX LATER TODAY...WE DO NOT THINK THAT THE FCST REGION WILL BE DEALING WITH A WIDESPREAD SEVERE WX EVENT AT THIS TIME. NOW TO THE NEXT ISSUE...THE HIGH TEMP FCST FOR TODAY. UPSTREAM OBS FROM THE UPPER OHIO VLY SHOW TEMPS IN THE LOWER 60S AS CLOSE AS CLEVELAND EARLY THIS MORNING. CONSIDERING THIS AIR WILL TRAVEL EAST OVER OUR REGION...WE/RE INCLINED TO BELIEVE TEMPS WILL WARM INTO THE UPPER 60S TO LOWER 70S AHEAD OF THE FRONT TODAY. ONLY ITEM OF CONCERN IS THE LATEST SATELLITE TRENDS WHICH SHOW ENHANCED CLOUD COVER APPROACHING FROM NORTHERN OHIO THIS MORNING. DESPITE THIS HOWEVER...DEGREE OF THERMAL ADVECTION WILL LIKELY BE ENOUGH TO OVERCOME LIMITED COOLING ASSOCIATED WITH INCREASING CLOUDS ALOFT. BY TONIGHT...COLD FRONT TO EXIT OFF TO THE EAST WITH TIME BETWEEN 00 AND 06Z. RAIN SHOULD GRADUALLY COME TO AN END WITH TIME WITH STRONG COLD AIR ADVECTION EXPECTED IN ITS WAKE. AS A RESULT...TEMPS WILL DROP INTO THE LOWER TO MIDDLE 30S ACROSS MUCH OF THE REGION WITH GUSTY WINDS EXPECTED THROUGH A GOOD PORTION OF THE OVERNIGHT HRS. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... COOLER TEMPS EXPECTED BOTH THU AND FRI AS COOL HIGH PRESSURE BUILDS IN FOLLOWING FROPA LATER TONIGHT. WITH H85 TEMPS QUICKLY FALLING TO NEAR ZERO CELSIUS...HIGH TEMPS ON THU ONLY LOOK TO WARM INTO THE LOWER TO MIDDLE 50S AT BEST. SLIGHTLY WARMER TEMPS EXPECTED ON FRI AS HIGH PRESSURE ADVANCES TO THE EAST WITH UPPER 50S TO LOWER 60S AGAIN POSSIBLE. WEAK UPPER WAVE WILL PASS ACROSS THE REGION THU NGT/EARLY FRI BRINGING THE NEXT ROUND OF SHWRS TO THE AREA. && .LONG TERM /SATURDAY THROUGH TUESDAY/... 300 PM UPDATE... SHAPING UP TO BE A BEAUTIFUL EXTENDED PERIOD WITH HIGH PRESSURE CENTERED OVER US TO START THE PERIOD THEN SHIFTING EAST BUT STILL IN CONTROL THROUGH EARLY NEXT WEEK. THE PATTERN IS RATHER STAGNANT SO WHILE WE WILL SEE TEMPS WARM INTO THE 60S DURING THIS TIME...THE TRUE STRONG WAA AND ASSOCIATED VERY WARM AIR WILL REMAIN WELL TO OUR WEST. SOME UNCERTAINTY DOES CREEP IN FROM SUNDAY NIGHT AND BEYOND AS BOTH THE EURO AND GFS SHOW AN AXIS OF MOISTURE JUST TO OUR WEST THROUGH THE OHIO VALLEY. THE GFS HINTS THAT WE MAY SEE SOME SHOWERS ESPECIALLY OVER THE FAR WESTERN FINGER LAKES DURING THIS TIME WHILE THE EURO IS MUCH DRIER. SOMETHING TO WATCH CAREFULLY BUT FOR NOW WILL KEEP MOST OF THE AREA DRY. && .AVIATION /16Z WEDNESDAY THROUGH SUNDAY/... VFR CONDS TODAY AHD OF A COLD FNT APRCHG THE AREA FROM WEST. FNT WILL BRING SHWRS AND ISLTD TRW STARTING ARND 21Z AND CONTG THRU ARND 00Z. MVFR CIGS AND VSBYS WITH THE SHWRS...ALONG WITH GUSTY WINDS. BHD THE FNT...CAA WILL BRING MVFR CIGS ALONG WITH SPOTTY MVFR VSBYS IN SHWRS. DRIER AIR WELL BHD THE FNT WILL RETURN SOME LOCATIONS TO VFR BEFORE THE END OF THE TAF PD. OUTLOOK... THU THRU SUN...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...CMG/RRM NEAR TERM...CMG/RRM SHORT TERM...CMG LONG TERM...HEDEN AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
640 AM EDT WED APR 24 2013 .SYNOPSIS... SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TODAY AS A STRONG COLD FRONT PASSES ACROSS THE AREA. BEHIND THIS FEATURE...DRY CONDITIONS ARE EXPECTED ON THURSDAY WITH THE NEXT ROUND OF SHOWERS POSSIBLE THURSDAY NIGHT AND EARLY FRIDAY AS ANOTHER WEAK WAVE WILL PASSES OVERHEAD. FAIR AND PLEASANT CONDITIONS ARE THEN EXPECTED FOR THE WEEKEND AS STRONG HIGH PRESSURE BUILDS INTO THE AREA. && .NEAR TERM /THROUGH TONIGHT/... 630 AM UPDATE... QUICK UPDATE TO ACCOUNT FOR LATEST RADAR TRENDS TO OUR WEST. REGIONAL RADARS NOW SHOWING AN INITIAL BAND OF LGT RAIN SHWRS WORKING INTO WESTERN NY THIS HR...WHICH APPEARS TO BE THE RESULT OF WEAK ISENTROPIC ASCENT ALONG/NORTH OF DIFFUSE WARM FRONT. THAT SAID...HAVE UPDATED GRIDS TO BRING IN RAIN A FEW HRS EARLIER ACROSS THE WESTERN AND NORTHERN ZONES. NO OTHER CHANGES NEEDED AT THE PRESENT TIME. PREVIOUS NEAR TERM DISCUSSION... A CHALLENGING FCST TO SAY THE LEAST TODAY AS A STRONG COLD FRONT WILL PLOW THROUGH THE REGION DURING THE LATE AFTERNOON AND EARLY EVENING HRS. THE MAIN DIFFICULTIES ARE TWOFOLD WITH THE FIRST BEING THE DEGREE OF WARMING PROCEEDING THE FRONT...AND THE SECOND CONCERNING SEVERE WX POTENTIAL AS THE FRONT BARRELS THROUGH THE REGION. FIRST THINGS FIRST HOWEVER AND WE SHOULD PROBABLY START WITH A GENERAL SYNOPTIC OVERVIEW. EARLY MORNING WATER VAPOR CLEARLY SHOWING A DEEP TROUGH OF LOW PRESSURE DIGGING ACROSS THE SOUTHERN PLAINS THIS MORNING WITH BROAD CYCLONIC FLOW PREVAILING OVER THE NATION/S MIDSECTION. ACROSS OUR REGION...WEAK UPPER RIDGING THAT BROUGHT SUCH NICE WX TO OUR AREA YESTERDAY NOW DEPARTING TO OUR EAST AS UPPER TROUGH AND ASSOCIATED DEFORMATION AXIS WITH THE WESTERN ATLANTIC COASTAL LOW WORK OFF THE NEW ENGLAND COAST. WITH TIME TODAY...COLD FRONT ASSOCIATED WITH THE CENTRAL US TROUGH WILL ADVANCE EAST OVER OUR REGION BY THIS AFTERNOON BRINGING WITH IT A PERIOD OF SHWRS AND STORMS TO MUCH OF OUR AREA. AS FOR THE SEVERE WX POTENTIAL...MODELS REMAIN ALL OVER THE PLACE WITH RESPECT TO THE DEGREE OF DESTABILIZATION THAT WILL OCCUR PRIOR TO FROPA LATER TODAY. THE NAM REMAINS THE MOST UNSTABLE SOLUTION THIS MORNING WITH AWIPS PLAN VIEW MAPS SHOWING A NARROW CORRIDOR OF MLCAPE VALUES RANGING FROM 400-500 J/KG IMMEDIATELY PROCEEDING THE FRONT MAINLY WEST OF THE I-81 CORRIDOR. THIS IS PERPLEXING TO SOME DEGREE AS CORRESPONDING NAM BUFKIT SOUNDINGS FOR ELM AND OTHER WESTERN FCST POINT LOCATIONS ADVERTISE MUCH LOWER VALUES. THE GFS SEEMS TO AGREE WITH THE WEAKER NAM BUFKIT SOLUTIONS...AS DOES THE LATEST RUC AND LOCALLY RUN WRF MODELS. AS FOR THE KINEMATICS...WIND FIELDS ALOFT REMAIN IMPRESSIVELY STRONG WITH 0-6 KM BULK SHEAR VECTORS RANGING FROM 40 TO 50 KTS ACROSS THE REGION WHILE 0-3 KM BULK SHEAR VALUES ARE JUST AS HIGH. THIS SUGGESTS THAT IF SEVERE WX WERE TO DEVELOP...DAMAGING WIND GUSTS WOULD BE THE BIGGEST THREATS IF ANY DEVELOPING CONVECTION WERE TO MORPH INTO A WELL-DEFINED SQUALL LINE OR SHORT BOWING SEGMENTS. THIS AGREES WELL WITH LOCAL SEVERE WX CHECKLIST WHICH SUGGEST A SIGNIFICANT COOL SEASON WIND EVENT IS POSSIBLE HOWEVER ITS HARD TO GET BY LATEST MODEL TRENDS OF VERY MODEST DESTABILIZATION. CONSIDERING THE AMOUNT OF CLOUD COVER THAT WILL LIKELY BEGIN MOVING OVERHEAD THIS MORNING COUPLED WITH THE FACT THAT RETURN FLOW MOISTURE WILL BE MEAGER AT BEST (AFTERNOON DEWPOINT TEMPS ONLY CLIMBING INTO THE MIDDLE TO UPPER 40S)...WE/RE INCLINED TO BELIEVE THAT SEVERE WX POTENTIAL WILL BE FAIRLY LIMITED. THIS AGREES WELL WITH THE LATEST SPC DAY 1 OUTLOOK WHICH ONLY ADVERTISES GENERAL THUNDER MENTION ACROSS OUR REGION ("SEE TEXT" TO OUR SOUTHWEST). ALTHOUGH WE TOTALLY CANNOT RULE OUT SEVERE WX LATER TODAY...WE DO NOT THINK THAT THE FCST REGION WILL BE DEALING WITH A WIDESPREAD SEVERE WX EVENT AT THIS TIME. NOW TO THE NEXT ISSUE...THE HIGH TEMP FCST FOR TODAY. UPSTREAM OBS FROM THE UPPER OHIO VLY SHOW TEMPS IN THE LOWER 60S AS CLOSE AS CLEVELAND EARLY THIS MORNING. CONSIDERING THIS AIR WILL TRAVEL EAST OVER OUR REGION...WE/RE INCLINED TO BELIEVE TEMPS WILL WARM INTO THE UPPER 60S TO LOWER 70S AHEAD OF THE FRONT TODAY. ONLY ITEM OF CONCERN IS THE LATEST SATELLITE TRENDS WHICH SHOW ENHANCED CLOUD COVER APPROACHING FROM NORTHERN OHIO THIS MORNING. DESPITE THIS HOWEVER...DEGREE OF THERMAL ADVECTION WILL LIKELY BE ENOUGH TO OVERCOME LIMITED COOLING ASSOCIATED WITH INCREASING CLOUDS ALOFT. BY TONIGHT...COLD FRONT TO EXIT OFF TO THE EAST WITH TIME BETWEEN 00 AND 06Z. RAIN SHOULD GRADUALLY COME TO AN END WITH TIME WITH STRONG COLD AIR ADVECTION EXPECTED IN ITS WAKE. AS A RESULT...TEMPS WILL DROP INTO THE LOWER TO MIDDLE 30S ACROSS MUCH OF THE REGION WITH GUSTY WINDS EXPECTED THROUGH A GOOD PORTION OF THE OVERNIGHT HRS. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... COOLER TEMPS EXPECTED BOTH THU AND FRI AS COOL HIGH PRESSURE BUILDS IN FOLLOWING FROPA LATER TONIGHT. WITH H85 TEMPS QUICKLY FALLING TO NEAR ZERO CELSIUS...HIGH TEMPS ON THU ONLY LOOK TO WARM INTO THE LOWER TO MIDDLE 50S AT BEST. SLIGHTLY WARMER TEMPS EXPECTED ON FRI AS HIGH PRESSURE ADVANCES TO THE EAST WITH UPPER 50S TO LOWER 60S AGAIN POSSIBLE. WEAK UPPER WAVE WILL PASS ACROSS THE REGION THU NGT/EARLY FRI BRINGING THE NEXT ROUND OF SHWRS TO THE AREA. && .LONG TERM /SATURDAY THROUGH TUESDAY/... 300 PM UPDATE... SHAPING UP TO BE A BEAUTIFUL EXTENDED PERIOD WITH HIGH PRESSURE CENTERED OVER US TO START THE PERIOD THEN SHIFTING EAST BUT STILL IN CONTROL THROUGH EARLY NEXT WEEK. THE PATTERN IS RATHER STAGNANT SO WHILE WE WILL SEE TEMPS WARM INTO THE 60S DURING THIS TIME...THE TRUE STRONG WAA AND ASSOCIATED VERY WARM AIR WILL REMAIN WELL TO OUR WEST. SOME UNCERTAINTY DOES CREEP IN FROM SUNDAY NIGHT AND BEYOND AS BOTH THE EURO AND GFS SHOW AN AXIS OF MOISTURE JUST TO OUR WEST THROUGH THE OHIO VALLEY. THE GFS HINTS THAT WE MAY SEE SOME SHOWERS ESPECIALLY OVER THE FAR WESTERN FINGER LAKES DURING THIS TIME WHILE THE EURO IS MUCH DRIER. SOMETHING TO WATCH CAREFULLY BUT FOR NOW WILL KEEP MOST OF THE AREA DRY. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... VFR CONDS TODAY AHD OF A COLD FNT APRCHG THE AREA FROM WEST. FNT WILL BRING SHWRS AND ISLTD TRW STARTING ARND 21Z AND CONTG THRU ARND 00Z. MVFR CIGS AND VSBYS WITH THE SHWRS...ALONG WITH GUSTY WINDS. BHD THE FNT...CAA WILL BRING MVFR CIGS ALONG WITH SPOTTY MVFR VSBYS IN SHWRS. DRIER AIR WELL BHD THE FNT WILL RETURN SOME LOCATIONS TO VFR BEFORE THE END OF THE TAF PD. OUTLOOK... THU THRU SUN...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...CMG NEAR TERM...CMG SHORT TERM...CMG LONG TERM...HEDEN AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
635 AM EDT WED APR 24 2013 .SYNOPSIS... SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TODAY AS A STRONG COLD FRONT PASSES ACROSS THE AREA. BEHIND THIS FEATURE...DRY CONDITIONS ARE EXPECTED ON THURSDAY WITH THE NEXT ROUND OF SHOWERS POSSIBLE THURSDAY NIGHT AND EARLY FRIDAY AS ANOTHER WEAK WAVE WILL PASSES OVERHEAD. FAIR AND PLEASANT CONDITIONS ARE THEN EXPECTED FOR THE WEEKEND AS STRONG HIGH PRESSURE BUILDS INTO THE AREA. && .NEAR TERM /THROUGH TONIGHT/... 630 AM UPDATE... QUICK UPDATE TO ACCOUNT FOR LATEST RADAR TRENDS TO OUR WEST. REGIONAL RADARS NOW SHOWING AN INITIAL BAND OF LGT RAIN SHWRS WORKING INTO WESTERN NY THIS HR...WHICH APPEARS TO BE THE RESULT OF WEAK ISENTROPIC ASCENT ALONG/NORTH OF DIFFUSE WARM FRONT. THAT SAID...HAVE UPDATED GRIDS TO BRING IN RAIN A FEW HRS EARLIER ACROSS THE WESTERN AND NORTHERN ZONES. NO OTHER CHANGES NEEDED AT THE PRESENT TIME. PREVIOUS NEAR TERM DISCUSSION... A CHALLENGING FCST TO SAY THE LEAST TODAY AS A STRONG COLD FRONT WILL PLOW THROUGH THE REGION DURING THE LATE AFTERNOON AND EARLY EVENING HRS. THE MAIN DIFFICULTIES ARE TWOFOLD WITH THE FIRST BEING THE DEGREE OF WARMING PROCEEDING THE FRONT...AND THE SECOND CONCERNING SEVERE WX POTENTIAL AS THE FRONT BARRELS THROUGH THE REGION. FIRST THINGS FIRST HOWEVER AND WE SHOULD PROBABLY START WITH A GENERAL SYNOPTIC OVERVIEW. EARLY MORNING WATER VAPOR CLEARLY SHOWING A DEEP TROUGH OF LOW PRESSURE DIGGING ACROSS THE SOUTHERN PLAINS THIS MORNING WITH BROAD CYCLONIC FLOW PREVAILING OVER THE NATION/S MIDSECTION. ACROSS OUR REGION...WEAK UPPER RIDGING THAT BROUGHT SUCH NICE WX TO OUR AREA YESTERDAY NOW DEPARTING TO OUR EAST AS UPPER TROUGH AND ASSOCIATED DEFORMATION AXIS WITH THE WESTERN ATLANTIC COASTAL LOW WORK OFF THE NEW ENGLAND COAST. WITH TIME TODAY...COLD FRONT ASSOCIATED WITH THE CENTRAL US TROUGH WILL ADVANCE EAST OVER OUR REGION BY THIS AFTERNOON BRINGING WITH IT A PERIOD OF SHWRS AND STORMS TO MUCH OF OUR AREA. AS FOR THE SEVERE WX POTENTIAL...MODELS REMAIN ALL OVER THE PLACE WITH RESPECT TO THE DEGREE OF DESTABILIZATION THAT WILL OCCUR PRIOR TO FROPA LATER TODAY. THE NAM REMAINS THE MOST UNSTABLE SOLUTION THIS MORNING WITH AWIPS PLAN VIEW MAPS SHOWING A NARROW CORRIDOR OF MLCAPE VALUES RANGING FROM 400-500 J/KG IMMEDIATELY PROCEEDING THE FRONT MAINLY WEST OF THE I-81 CORRIDOR. THIS IS PERPLEXING TO SOME DEGREE AS CORRESPONDING NAM BUFKIT SOUNDINGS FOR ELM AND OTHER WESTERN FCST POINT LOCATIONS ADVERTISE MUCH LOWER VALUES. THE GFS SEEMS TO AGREE WITH THE WEAKER NAM BUFKIT SOLUTIONS...AS DOES THE LATEST RUC AND LOCALLY RUN WRF MODELS. AS FOR THE KINEMATICS...WIND FIELDS ALOFT REMAIN IMPRESSIVELY STRONG WITH 0-6 KM BULK SHEAR VECTORS RANGING FROM 40 TO 50 KTS ACROSS THE REGION WHILE 0-3 KM BULK SHEAR VALUES ARE JUST AS HIGH. THIS SUGGESTS THAT IF SEVERE WX WERE TO DEVELOP...DAMAGING WIND GUSTS WOULD BE THE BIGGEST THREATS IF ANY DEVELOPING CONVECTION WERE TO MORPH INTO A WELL-DEFINED SQUALL LINE OR SHORT BOWING SEGMENTS. THIS AGREES WELL WITH LOCAL SEVERE WX CHECKLIST WHICH SUGGEST A SIGNIFICANT COOL SEASON WIND EVENT IS POSSIBLE HOWEVER ITS HARD TO GET BY LATEST MODEL TRENDS OF VERY MODEST DESTABILIZATION. CONSIDERING THE AMOUNT OF CLOUD COVER THAT WILL LIKELY BEGIN MOVING OVERHEAD THIS MORNING COUPLED WITH THE FACT THAT RETURN FLOW MOISTURE WILL BE MEAGER AT BEST (AFTERNOON DEWPOINT TEMPS ONLY CLIMBING INTO THE MIDDLE TO UPPER 40S)...WE/RE INCLINED TO BELIEVE THAT SEVERE WX POTENTIAL WILL BE FAIRLY LIMITED. THIS AGREES WELL WITH THE LATEST SPC DAY 1 OUTLOOK WHICH ONLY ADVERTISES GENERAL THUNDER MENTION ACROSS OUR REGION ("SEE TEXT" TO OUR SOUTHWEST). ALTHOUGH WE TOTALLY CANNOT RULE OUT SEVERE WX LATER TODAY...WE DO NOT THINK THAT THE FCST REGION WILL BE DEALING WITH A WIDESPREAD SEVERE WX EVENT AT THIS TIME. NOW TO THE NEXT ISSUE...THE HIGH TEMP FCST FOR TODAY. UPSTREAM OBS FROM THE UPPER OHIO VLY SHOW TEMPS IN THE LOWER 60S AS CLOSE AS CLEVELAND EARLY THIS MORNING. CONSIDERING THIS AIR WILL TRAVEL EAST OVER OUR REGION...WE/RE INCLINED TO BELIEVE TEMPS WILL WARM INTO THE UPPER 60S TO LOWER 70S AHEAD OF THE FRONT TODAY. ONLY ITEM OF CONCERN IS THE LATEST SATELLITE TRENDS WHICH SHOW ENHANCED CLOUD COVER APPROACHING FROM NORTHERN OHIO THIS MORNING. DESPITE THIS HOWEVER...DEGREE OF THERMAL ADVECTION WILL LIKELY BE ENOUGH TO OVERCOME LIMITED COOLING ASSOCIATED WITH INCREASING CLOUDS ALOFT. BY TONIGHT...COLD FRONT TO EXIT OFF TO THE EAST WITH TIME BETWEEN 00 AND 06Z. RAIN SHOULD GRADUALLY COME TO AN END WITH TIME WITH STRONG COLD AIR ADVECTION EXPECTED IN ITS WAKE. AS A RESULT...TEMPS WILL DROP INTO THE LOWER TO MIDDLE 30S ACROSS MUCH OF THE REGION WITH GUSTY WINDS EXPECTED THROUGH A GOOD PORTION OF THE OVERNIGHT HRS. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... COOLER TEMPS EXPECTED BOTH THU AND FRI AS COOL HIGH PRESSURE BUILDS IN FOLLOWING FROPA LATER TONIGHT. WITH H85 TEMPS QUICKLY FALLING TO NEAR ZERO CELSIUS...HIGH TEMPS ON THU ONLY LOOK TO WARM INTO THE LOWER TO MIDDLE 50S AT BEST. SLIGHTLY WARMER TEMPS EXPECTED ON FRI AS HIGH PRESSURE ADVANCES TO THE EAST WITH UPPER 50S TO LOWER 60S AGAIN POSSIBLE. WEAK UPPER WAVE WILL PASS ACROSS THE REGION THU NGT/EARLY FRI BRINGING THE NEXT ROUND OF SHWRS TO THE AREA. && .LONG TERM /SATURDAY THROUGH TUESDAY/... 300 PM UPDATE... SHAPING UP TO BE A BEAUTIFUL EXTENDED PERIOD WITH HIGH PRESSURE CENTERED OVER US TO START THE PERIOD THEN SHIFTING EAST BUT STILL IN CONTROL THROUGH EARLY NEXT WEEK. THE PATTERN IS RATHER STAGNANT SO WHILE WE WILL SEE TEMPS WARM INTO THE 60S DURING THIS TIME...THE TRUE STRONG WAA AND ASSOCIATED VERY WARM AIR WILL REMAIN WELL TO OUR WEST. SOME UNCERTAINTY DOES CREEP IN FROM SUNDAY NIGHT AND BEYOND AS BOTH THE EURO AND GFS SHOW AN AXIS OF MOISTURE JUST TO OUR WEST THROUGH THE OHIO VALLEY. THE GFS HINTS THAT WE MAY SEE SOME SHOWERS ESPECIALLY OVER THE FAR WESTERN FINGER LAKES DURING THIS TIME WHILE THE EURO IS MUCH DRIER. SOMETHING TO WATCH CAREFULLY BUT FOR NOW WILL KEEP MOST OF THE AREA DRY. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... GNRL VFR CONDS WILL CONT TNGT AND MUCH OF WED. ONLY XCPTN IS THE MARINE LYR CLDS THAT MAY BRING AN OCNL MVFR CIG TO AVP OVRNGT. OTRW...STRONG FNT MVES INTO THE AREA BEGINNING ARND 21Z WITH A GOOD CHANCE OF CONV WITH MVFR CIGS AND VSBYS IN BRIEF HEAVY RAIN. WINDS SHD BE QUITE GUSTY INVOF OF THE FNT...WITH A SWITCH TO THE WEST AFTER PASSAGE. BHD THE FNT...CAA SC WILL KEEP CIGS IN THE MVFR RANGE THRU THE END OF THE PD. OUTLOOK... WED NGT...MVFR IN SHRA. THU THRU SUN...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...CMG NEAR TERM...CMG SHORT TERM...CMG LONG TERM...HEDEN AVIATION...DGM/DJN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
439 AM EDT WED APR 24 2013 .SYNOPSIS... SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TODAY AS A STRONG COLD FRONT PASSES ACROSS THE AREA. BEHIND THIS FEATURE...DRY CONDITIONS ARE EXPECTED ON THURSDAY WITH THE NEXT ROUND OF SHOWERS POSSIBLE THURSDAY NIGHT AND EARLY FRIDAY AS ANOTHER WEAK WAVE WILL PASSES OVERHEAD. FAIR AND PLEASANT CONDITIONS ARE THEN EXPECTED FOR THE WEEKEND AS STRONG HIGH PRESSURE BUILDS INTO THE AREA. && .NEAR TERM /THROUGH TONIGHT/... A CHALLENGING FCST TO SAY THE LEAST TODAY AS A STRONG COLD FRONT WILL PLOW THROUGH THE REGION DURING THE LATE AFTERNOON AND EARLY EVENING HRS. THE MAIN DIFFICULTIES ARE TWOFOLD WITH THE FIRST BEING THE DEGREE OF WARMING PROCEEDING THE FRONT...AND THE SECOND CONCERNING SEVERE WX POTENTIAL AS THE FRONT BARRELS THROUGH THE REGION. FIRST THINGS FIRST HOWEVER AND WE SHOULD PROBABLY START WITH A GENERAL SYNOPTIC OVERVIEW. EARLY MORNING WATER VAPOR CLEARLY SHOWING A DEEP TROUGH OF LOW PRESSURE DIGGING ACROSS THE SOUTHERN PLAINS THIS MORNING WITH BROAD CYCLONIC FLOW PREVAILING OVER THE NATION/S MIDSECTION. ACROSS OUR REGION...WEAK UPPER RIDGING THAT BROUGHT SUCH NICE WX TO OUR AREA YESTERDAY NOW DEPARTING TO OUR EAST AS UPPER TROUGH AND ASSOCIATED DEFORMATION AXIS WITH THE WESTERN ATLANTIC COASTAL LOW WORK OFF THE NEW ENGLAND COAST. WITH TIME TODAY...COLD FRONT ASSOCIATED WITH THE CENTRAL US TROUGH WILL ADVANCE EAST OVER OUR REGION BY THIS AFTERNOON BRINGING WITH IT A PERIOD OF SHWRS AND STORMS TO MUCH OF OUR AREA. AS FOR THE SEVERE WX POTENTIAL...MODELS REMAIN ALL OVER THE PLACE WITH RESPECT TO THE DEGREE OF DESTABILIZATION THAT WILL OCCUR PRIOR TO FROPA LATER TODAY. THE NAM REMAINS THE MOST UNSTABLE SOLUTION THIS MORNING WITH AWIPS PLAN VIEW MAPS SHOWING A NARROW CORRIDOR OF MLCAPE VALUES RANGING FROM 400-500 J/KG IMMEDIATELY PROCEEDING THE FRONT MAINLY WEST OF THE I-81 CORRIDOR. THIS IS PERPLEXING TO SOME DEGREE AS CORRESPONDING NAM BUFKIT SOUNDINGS FOR ELM AND OTHER WESTERN FCST POINT LOCATIONS ADVERTISE MUCH LOWER VALUES. THE GFS SEEMS TO AGREE WITH THE WEAKER NAM BUFKIT SOLUTIONS...AS DOES THE LATEST RUC AND LOCALLY RUN WRF MODELS. AS FOR THE KINEMATICS...WIND FIELDS ALOFT REMAIN IMPRESSIVELY STRONG WITH 0-6 KM BULK SHEAR VECTORS RANGING FROM 40 TO 50 KTS ACROSS THE REGION WHILE 0-3 KM BULK SHEAR VALUES ARE JUST AS HIGH. THIS SUGGESTS THAT IF SEVERE WX WERE TO DEVELOP...DAMAGING WIND GUSTS WOULD BE THE BIGGEST THREATS IF ANY DEVELOPING CONVECTION WERE TO MORPH INTO A WELL-DEFINED SQUALL LINE OR SHORT BOWING SEGMENTS. THIS AGREES WELL WITH LOCAL SEVERE WX CHECKLIST WHICH SUGGEST A SIGNIFICANT COOL SEASON WIND EVENT IS POSSIBLE HOWEVER ITS HARD TO GET BY LATEST MODEL TRENDS OF VERY MODEST DESTABILIZATION. CONSIDERING THE AMOUNT OF CLOUD COVER THAT WILL LIKELY BEGIN MOVING OVERHEAD THIS MORNING COUPLED WITH THE FACT THAT RETURN FLOW MOISTURE WILL BE MEAGER AT BEST (AFTERNOON DEWPOINT TEMPS ONLY CLIMBING INTO THE MIDDLE TO UPPER 40S)...WE/RE INCLINED TO BELIEVE THAT SEVERE WX POTENTIAL WILL BE FAIRLY LIMITED. THIS AGREES WELL WITH THE LATEST SPC DAY 1 OUTLOOK WHICH ONLY ADVERTISES GENERAL THUNDER MENTION ACROSS OUR REGION ("SEE TEXT" TO OUR SOUTHWEST). ALTHOUGH WE TOTALLY CANNOT RULE OUT SEVERE WX LATER TODAY...WE DO NOT THINK THAT THE FCST REGION WILL BE DEALING WITH A WIDESPREAD SEVERE WX EVENT AT THIS TIME. NOW TO THE NEXT ISSUE...THE HIGH TEMP FCST FOR TODAY. UPSTREAM OBS FROM THE UPPER OHIO VLY SHOW TEMPS IN THE LOWER 60S AS CLOSE AS CLEVELAND EARLY THIS MORNING. CONSIDERING THIS AIR WILL TRAVEL EAST OVER OUR REGION...WE/RE INCLINED TO BELIEVE TEMPS WILL WARM INTO THE UPPER 60S TO LOWER 70S AHEAD OF THE FRONT TODAY. ONLY ITEM OF CONCERN IS THE LATEST SATELLITE TRENDS WHICH SHOW ENHANCED CLOUD COVER APPROACHING FROM NORTHERN OHIO THIS MORNING. DESPITE THIS HOWEVER...DEGREE OF THERMAL ADVECTION WILL LIKELY BE ENOUGH TO OVERCOME LIMITED COOLING ASSOCIATED WITH INCREASING CLOUDS ALOFT. BY TONIGHT...COLD FRONT TO EXIT OFF TO THE EAST WITH TIME BETWEEN 00 AND 06Z. RAIN SHOULD GRADUALLY COME TO AN END WITH TIME WITH STRONG COLD AIR ADVECTION EXPECTED IN ITS WAKE. AS A RESULT...TEMPS WILL DROP INTO THE LOWER TO MIDDLE 30S ACROSS MUCH OF THE REGION WITH GUSTY WINDS EXPECTED THROUGH A GOOD PORTION OF THE OVERNIGHT HRS. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... COOLER TEMPS EXPECTED BOTH THU AND FRI AS COOL HIGH PRESSURE BUILDS IN FOLLOWING FROPA LATER TONIGHT. WITH H85 TEMPS QUICKLY FALLING TO NEAR ZERO CELSIUS...HIGH TEMPS ON THU ONLY LOOK TO WARM INTO THE LOWER TO MIDDLE 50S AT BEST. SLIGHTLY WARMER TEMPS EXPECTED ON FRI AS HIGH PRESSURE ADVANCES TO THE EAST WITH UPPER 50S TO LOWER 60S AGAIN POSSIBLE. WEAK UPPER WAVE WILL PASS ACROSS THE REGION THU NGT/EARLY FRI BRINGING THE NEXT ROUND OF SHWRS TO THE AREA. && .LONG TERM /SATURDAY THROUGH TUESDAY/... 300 PM UPDATE... SHAPING UP TO BE A BEAUTIFUL EXTENDED PERIOD WITH HIGH PRESSURE CENTERED OVER US TO START THE PERIOD THEN SHIFTING EAST BUT STILL IN CONTROL THROUGH EARLY NEXT WEEK. THE PATTERN IS RATHER STAGNANT SO WHILE WE WILL SEE TEMPS WARM INTO THE 60S DURING THIS TIME...THE TRUE STRONG WAA AND ASSOCIATED VERY WARM AIR WILL REMAIN WELL TO OUR WEST. SOME UNCERTAINTY DOES CREEP IN FROM SUNDAY NIGHT AND BEYOND AS BOTH THE EURO AND GFS SHOW AN AXIS OF MOISTURE JUST TO OUR WEST THROUGH THE OHIO VALLEY. THE GFS HINTS THAT WE MAY SEE SOME SHOWERS ESPECIALLY OVER THE FAR WESTERN FINGER LAKES DURING THIS TIME WHILE THE EURO IS MUCH DRIER. SOMETHING TO WATCH CAREFULLY BUT FOR NOW WILL KEEP MOST OF THE AREA DRY. && .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/... GNRL VFR CONDS WILL CONT TNGT AND MUCH OF WED. ONLY XCPTN IS THE MARINE LYR CLDS THAT MAY BRING AN OCNL MVFR CIG TO AVP OVRNGT. OTRW...STRONG FNT MVES INTO THE AREA BEGINNING ARND 21Z WITH A GOOD CHANCE OF CONV WITH MVFR CIGS AND VSBYS IN BRIEF HEAVY RAIN. WINDS SHD BE QUITE GUSTY INVOF OF THE FNT...WITH A SWITCH TO THE WEST AFTER PASSAGE. BHD THE FNT...CAA SC WILL KEEP CIGS IN THE MVFR RANGE THRU THE END OF THE PD. OUTLOOK... WED NGT...MVFR IN SHRA. THU THRU SUN...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...CMG NEAR TERM...CMG SHORT TERM...CMG LONG TERM...HEDEN AVIATION...DGM/DJN
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1147 PM CDT TUE APR 23 2013 .UPDATE... ISSUED AT 1147 PM CDT TUE APR 23 2013 CONTINUED TREND OF SLOWING DOWN POPS MOVING INTO THE FAR WESTERN CWA DURING THE EARLY MORNING HOURS AND THEN THROUGH THE REST OF THE CWA DURING THE DAY TOMORROW. THE MODELS STILL SHOWING A LOT OF VARIATION IN THE EXACT PLACEMENT OF QPF BUT SEEM TO BE A BIT BETTER ON THE GENERAL TREND OF THE BEST PRECIP IN THE EASTERN COUNTIES DURING THE AFTERNOON AS THE MAIN UPPER WAVE DIGS DOWN INTO THE AREA. WILL CONTINUE TO KEEP LIKELY POPS IN THAT AREA DURING THE AFTERNOON. ANY AMOUNTS SHOULD REMAIN AROUND AN INCH OR LESS ON GRASSY AREAS. UPDATE ISSUED AT 1013 PM CDT TUE APR 23 2013 MAIN CHANGE WAS TO SLOW DOWN THE PROGRESSION OF PRECIP INTO THE AREA TONIGHT AND TOMORROW...AS THE RAP AND NAM ARE BACKING OFF ON PRECIP AND ONLY A TINY AMOUNT IS FALLING IN THE WEST SO FAR. THINK THAT PRECIP WILL BE MOSTLY AFTER SUNRISE TOMORROW AND ANYTHING SHOULD BE PRETTY LIGHT. UPDATE ISSUED AT 701 PM CDT TUE APR 23 2013 LOWERED CLOUD COVER A BIT THIS EVENING AS IT SEEMS MOST OF THE BEST COVERAGE WILL HOLD OFF UNTIL AFTER MIDNIGHT AS THE SHORTWAVE IN CANADA APPROACHES. NO OTHER CHANGES. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 344 PM CDT TUE APR 23 2013 SEEMS LIKE THE MOST CUMULUS DEVELOPMENT TODAY WAS JUST TO THE EAST OF THE RED RIVER VALLEY. OTHERWISE THERE ARE SOME HIGH LEVEL CLOUDS STREAMING INTO THE WESTERN FA. GENERALLY EXPECT CLOUDS TO INCREASE TONIGHT BUT IT MAY TAKE LONGER FOR THEM TO REACH THE EAST AND SOUTHEAST FA. THE NEXT UPSTREAM WAVE IS CURRENTLY OVER NORTHEAST ALBERTA AND IS FORECAST TO DROP INTO THE FA LATE TONIGHT. WENT AHEAD AND INCREASED PCPN CHANCES INTO THE LIKELY RANGE IN THE NORTHWEST FA TOWARD WED MORNING. LOOKS LIKE THIS WILL BE A HIGH POP/LOW QPF EVENT OVERALL. THE SFC REFLECTION OF THE ABOVE MENTIONED WAVE WILL BE A COLD FRONT THAT DROPS INTO THE NORTHWEST FA BY WED MORNING. AS THIS FEATURE DROPS THRU THE FA DURING THE DAY EXPECT THE BEST CHANCES FOR PCPN TO BE ACROSS THE NORTH AND NORTHEAST. HOWEVER THERE SHOULD BE SOME LIGHT SNOW JUST ABOUT EVERYWHERE. AS IN THE PAST FEW EVENTS IT SHOULD MELT ON THE ROADS AND JUST STAY WET DURING THE DAYTIME HOURS WITH THE ONLY ACCUMULATION IN GRASSY/SNOW COVERED AREAS. WPC SNOWFALL GRAPHIC SHOWING THE POSSIBILITY FOR AN INCH OR SO OF SNOW ALONG AND NORTH OF THE HIGHWAY 2 CORRIDOR AND THAT SEEMS REASONABLE. SREF PCPN TYPE SEEMS PRETTY WELL PEGGED ON JUST SNOW AND WILL GO WITH THAT IDEA TOO. THINK SOME AFTERNOON TEMPS MAY GET INTO THE MID 30S BUT THAT WOULD BE ABOUT IT. BY WED NIGHT THE SYSTEM SHOULD BE PULLING OFF TO THE EAST. LEFT SOME VERY LOW CHANCES FOR LIGHT SNOW IN THE FAR EAST EARLY. LOWS WILL PROBABLY DEPEND ON HOW FAST OR IF THE CLOUDS CLEAR OUT. THERE IS SOME PRETTY STRONG WARM ADVECTION THAT KICKS IN ESPECIALLY ACROSS THE WEST WHICH MAY LEAD TO INCREASING CLOUDS. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 344 PM CDT TUE APR 23 2013 THU-FRI...SOUTH WINDS ON THU WITH THE GOOD WARM ADVECTION SHIFTING OVER THE FA. LOOKING LIKE 850MB TEMPS SHOULD RISE BACK ABOVE ZERO BY 00Z FRI. THE WARMER WEATHER CONTINUES TO LOOK ON TRACK INTO FRI AS WELL. DEGREE OF WARMING MAY DEPEND ON HOW MUCH SFC WIND OCCURS WITH MODELS SHOWING FAIRLY WEAK WINDS ON FRI. FRIDAY NIGHT-TUESDAY...ECMWF AND GFS ARE IN GOOD AGREEMENT DEPICTING ZONAL TO SOUTHWEST FLOW ALOFT INTO SUNDAY...BUT THEN BECOME OUT OF PHASE FOR MONDAY AND TUESDAY. FOR MONDAY INTO TUESDAY...THE ECMWF IS MORE AMPLIFIED WITH THE WEST COAST TROUGH/EAST COAST RIDGE COMPARED TO THE GFS. THE ECMWF SOLUTION WOULD KEEP A SURFACE BOUNDARY ACROSS THE FA ALONG WITH A MORE PROLONGED PERIOD OF SHOWER AND/OR THUNDERSTORM CHANCES. THE GFS SOLUTION WOULD LEAD TO ONLY A BRIEF PERIOD OF SHOWERS AND/OR THUNDERSTORMS (LIKELY ON MONDAY) WITH HIGH PRESSURE MOVING INTO THE REGION BY MID-WEEK. THESE ARE OBVIOUSLY BIG DIFFERENCES AND IMPORTANT GIVEN THE STATE OF RIVER FLOODING. GIVEN THE LOW CONFIDENCE IN ANY ONE PARTICULAR SOLUTION...WILL GO WITH LOW END RAIN CHANCES. TEMPERATURES WILL BE THE OTHER BIG CHALLENGE. A MUCH WARMER AIRMASS WILL HAVE BEEN ADVECTED INTO THE REGION AND EXPECT MORE NEAR NORMAL TEMPERATURES. SNOWPACK WILL DETERMINE HOW WARM...AND THINK MOST AREAS SHOULD HAVE ENOUGH SNOW MELTED TO REALIZE WARMER VALUES. THE EXCEPTION WILL BE THE DEVILS LAKE BASIN WHERE THE SNOW NORMALLY TAKES LONGER TO MELT...AND KEPT MAX TEMPS IN THE 40S. WILL NOT WORRY ABOUT FOG...BUT THAT COULD AFFECT TEMPERATURES AS WELL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1147 PM CDT TUE APR 23 2013 VFR CONDITIONS WILL CONTINUE AS ONLY A FEW STRAY CLOUDS IN THE 3500-6000 RANGE PASS OVER THE AREA THIS EVENING. CONDITIONS SHOULD GO DOWN TO MVFR IN THE WEST BY EARLY MORNING AND AT THE TAF SITES FURTHER EAST LATER IN THE DAY. BACKED OFF ON VIS A BIT AND KEPT REDUCTIONS AROUND THE 3-5SM RANGE. WEST TO NORTHWEST WINDS WILL PICK UP AND GUST TO AROUND 25 KTS AT TIMES DURING THE AFTERNOON. CONDTIONS SHOULD RETURN TO VFR AND WINDS DECREASE AT THE END OF THE PERIOD. && .HYDROLOGY... ISSUED AT 1254 PM CDT TUE APR 23 2013 RIVER FLOOD WARNINGS CONTINUE FOR THE RED RIVER AT WAHPETON/HICKSON/ FARGO...THE SOUTH BRANCH BUFFALO RIVER AT SABIN AND THE BUFFALO RIVER AT DILWORTH. OVERALL...THE RATE AT WHICH THESE RIVERS ARE EXPECTED TO RISE THROUGH FRIDAY WAS LOWERED DUE TO COLD TEMPERATURES LIMITING THE MELT AND THE FORECAST CREST AT WAHPETON WAS LOWERED HALF A FOOT TO 16.5 FT TO ACCOUNT FOR LESS AVAILABLE OBSERVED RUNOFF SOUTH OF HWY 210 ACROSS WEST CENTRAL MN. LOCALIZED SNOWMELT RUNOFF WILL RESULT IN GRADUAL RISES ALONG THE RED RIVER AT WAHPETON...HICKSON AND FARGO FOR MUCH OF THIS WEEK. ADDITIONAL RISES ARE ALSO EXPECTED ALONG THE SOUTH BRANCH BUFFALO RIVER AT SABIN AND THE BUFFALO RIVER AT DILWORTH. VERY COOL LATE APRIL TEMPERATURES WILL CONTINUE THROUGH THURSDAY WITH DAYTIME HIGHS IN THE 30S AND LOWER 40S AND NIGHTTIME LOWS IN THE UPPER TEENS AND 20S. THESE TEMPERATURES WILL LIMIT THE DEGREE OF SNOWMELT THROUGH MUCH OF THE WEEK. FRIDAY INTO THE WEEKEND...TEMPERATURES ARE EXPECTED TO RISE SIGNIFICANTLY...WITH HIGHS IN THE LOWER 60S POSSIBLE THIS WEEKEND. MORNING LOWS ARE ALSO EXPECTED TO RISE ABOVE FREEZING...RESULTING IN SIGNIFICANT SNOWMELT RUNOFF AND MORE RAPID RISES IN RIVER LEVELS. WITH NO SIGNIFICANT PRECIPITATION EXPECTED THE NEXT SEVERAL DAYS...RIVER RISES WILL DEPEND HEAVILY ON THE TEMPERATURE PATTERN AND RESULTANT SNOWMELT. IN ADDITION...A LATE PROLONGED SNOWMELT HAS ALLOWED SOME OF THE EARLIER MELT WATER TO INFILTRATE THE SOIL. EXACT AMOUNTS ARE UNCERTAIN AT THIS TIME AND THIS UNCERTAINTY IS REFLECTED IN A RANGE OF CRESTS FOR THE RED RIVER AT WAHPETON. THUS...FORECAST RIVER LEVELS FOR THIS WEEKEND ARE SUBJECT TO FURTHER REVISIONS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...JR SHORT TERM...GODON LONG TERM...TG AVIATION...JR HYDROLOGY...ROGERS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
407 PM EDT WED APR 24 2013 .SYNOPSIS... A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION TONIGHT. THE HIGH WILL MOVE EAST ON THURSDAY AS A WEAK COLD FRONT MOVES ACROSS THE AREA. THIS FRONT WILL BE FOLLOWED BY ANOTHER HIGH PRESSURE SYSTEM THURSDAY NIGHT INTO FRIDAY. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH THE PERIOD. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... MODELS WERE IN FAIRLY DECENT AGREEMENT. HAVE USED A BLEND OF THE GFS...NAM AND RAP FOR THE NEAR TERM FORECAST. COLD FRONT WAS EAST OF THE FORECAST AREA THIS AFTERNOON. CLOUDS CONTINUE TO LINGER AS WELL AS A FEW SHOWERS ACRS THE NRN ZONES. A RIDGE OF HIGH PRESSURE TO OUR WEST IS EXPECTED TO BUILD EAST INTO THE REGION TONIGHT. THIS WILL ALLOW SKIES TO CLEAR FROM WEST TO EAST AS WELL AS ALLOW WINDS TO DIMINISH. THERE IS CONCERN FOR FROST AND/OR FREEZING TEMPERATURES OVERNIGHT. CONCERNING FROST FORMATION...THE BEST CHANCES WILL BE IN THE EASTERN/SOUTHERN ZONES WHERE WINDS WILL BE THE LIGHTEST THE LONGEST AND SHOULD NOT BE AFFECTED BY A LATE INCREASE IN WIND FROM THE WEST AS A WEAK COLD FRONT APPROACHES. THE FAR NW HAS THE LEAST POTENTIAL FOR FROST DUE TO THE INCREASING PRESSURE GRADIENT LATE AS THE HIGH DEPARTS TO THE EAST AND AFOREMENTIONED WEAK COLD FRONT APPROACHES. HOWEVER... THERE COULD BE A SHORT WINDOW FOR FROST FORMATION...ESPECIALLY IN LOW LYING...SHELTERED LOCATIONS SO HAVE INCLUDED FROST HERE AS WELL. AS FOR FROST AND FREEZING TEMPERATURES...IT LOOKS LIKE A GOOD PORTION OF CENTRAL OHIO WILL HAVE THE HIGHEST THREAT OF REACHING FREEZING OR FALLING SLIGHTLY BELOW. IN SUMMARY...A FREEZING WARNING HAS BEEN POSTED FOR MUCH OF CENTRAL OHIO (INCLUDING HARDIN COUNTY) WHILE A FROST ADVISORY HAS BEEN ISSUED ELSEWHERE. GIVEN RECENT RAINFALL...THERE COULD BE SOME FOG DEVELOPMENT IN THE ERN/SRN LOCATIONS OVERNIGHT...BUT CONFIDENCE IN POTENTIAL PUBLIC IMPACT IS LOW AT THIS POINT AND HAVE LEFT OUT ATTM. OVERNIGHT LOWS WILL GENERALLY BE IN THE LOWER TO MID 30S WITH A FEW UPPER 20S POSSIBLE ACROSS PARTS OF CENTRAL OHIO. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... RIDGE OF HIGH PRESSURE WILL MOVE EAST ON THURSDAY AS WEAK LOW PRESSURE AND A COLD FRONT MOVE ACROSS THE GREAT LAKES AND OHIO VALLEY. DEEPEST MOISTURE AND BEST LIFT ARE EXPECTED OVER THE NRN ZONES AND HAVE CARRIED A CHANCE OF SHOWERS MAINLY ALONG AND NORTH OF I-70. ELSEWHERE...SKIES WILL BE PARTLY SUNNY. TEMPERATURES WILL BE TRICKY GIVEN SOME AFTERNOON CAA BEHIND THE FRONT AND CLOUD DEVELOPMENT. WILL RANGE HIGHS FROM THE LOWER 50S NORTHWEST TO THE LOWER 60S ALONG AND SOUTH OF THE OHIO RIVER. WEAK WEATHER SYSTEM WILL PUSH EAST BY THURSDAY NIGHT...ALLOWING ANOTHER AREA OF HIGH PRESSURE TO BUILD INTO THE REGION. SKIES WILL CLEAR AND WINDS WILL DIMINISH. IT LOOKS LIKE A FAVORABLE NIGHT FOR FROST FORMATION SO HAVE INCLUDED THIS WORDING IN THE FORECAST AND HAVE MADE A MENTION OF IT IN THE HWO PRODUCT. OVERNIGHT LOWS WILL BE IN THE LOWER TO MID 30S. FOR FRIDAY INTO FRIDAY NIGHT...HIGH PRESSURE WILL CONTINUE TO INFLUENCE THE REGION. RETURN SFC FLOW IS THE BEST ACROSS THE WEST AND WEAKEST ELSEWHERE. ALSO...DESPITE SUNSHINE...850 MB TEMPS APPEAR TO WARM UP MORE SLOWLY. AS A RESULT...HAVE GONE COOLER THAN MOS GUIDANCE AS IT APPEARS TO BE WARMING THINGS UP A LITTLE TOO MUCH. SOME CLOUDS WILL INCREASE LATER FRIDAY INTO FRIDAY NIGHT FROM A MID LVL TROUGH TO OUR WEST...OTHERWISE DRY CONDITIONS ARE EXPECTED. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... SURFACE HIGH PRESSURE WILL BE DEPARTING THE CWA AT THE START OF THE EXTENDED FORECAST PERIOD. MODEL AGREEMENT IS RELATIVELY POOR IN HANDLING THE EVOLUTION OF A SLOW-MOVING MID-LEVEL TROUGH OVER THE WEEKEND. EVEN AT 72HR ON THE 12Z GFSE...THERE IS SIGNIFICANT SPREAD BETWEEN THE ENSEMBLE MEMBERS ON THE STRENGTH AND PLACEMENT OF THE TROUGH. THE OPERATIONAL GFS SEEMS TO BE STRONGER WITH THE TROUGH THAN MOST OF ITS MEMBERS...WHILE THE OPERATIONAL 12Z ECMWF IS A BIT CLOSER TO THE GFSE MEAN. LEANING TOWARD THE SLIGHTLY WEAKER SOLUTION WOULD PROVIDE LESS IN THE WAY OF PRECIPITATION THAN THE OPERATIONAL GFS INDICATES. THUS...THE FORECAST WILL START DRY...AND POPS WILL GENERALLY BE HELD IN THE 20-40 CATEGORY AND NO HIGHER (THOUGH IT WILL BE WETTER FURTHER SOUTH IN THE TENNESSEE VALLEY). THE HIGHEST POPS WERE ROUGHLY TIMED TO THE DIURNAL CYCLE. BY MONDAY...THE AXIS OF THE TROUGH WILL BE MOVING EAST OF THE REGION...AS A BIG CHANGE TO THE WEATHER PATTERN BEGINS. THERE IS SOME DEGREE OF AGREEMENT REGARDING THE LARGE-SCALE EVOLUTION NEXT WEEK...WITH SIGNS OF HIGHLY-AMPLIFIED HIGH PRESSURE DEVELOPING FROM THE DEEP SOUTH THROUGH THE OHIO VALLEY AND INTO ONTARIO. IN FACT...BY THE VERY END OF THE EXTENDED FORECAST (AND INTO LATE WEEK) BOTH 12Z OPERATIONAL RUNS (GFS/ECMWF) AND THE 00Z ECMWF SHOW A FULL-OUT OMEGA BLOCK DEVELOPING (TROUGH IN THE CENTRAL PLAINS / RIDGE THROUGH THE EASTERN STATES / TROUGH OVER THE ATLANTIC). WITH THIS AGREEMENT...THE 12Z CMC (WHICH DEVELOPS A CLOSED LOW OVER THE DEEP SOUTH ON TUESDAY) WAS NOT USED FOR THE FORECAST. THROUGH THE FIRST PART OF THE WEEK...DIURNALLY-DRIVEN POPS WERE MAINTAINED (THOUGH GRADUALLY DECREASING EACH DAY AS THE RIDGE BUILDS). SIGNIFICANT PRECIPITATION APPEARS TO REMAIN WEST OF THE ILN CWA THROUGH AT LEAST WEDNESDAY. TEMPERATURES APPEAR TO SLOWLY RISE THROUGH THIS PERIOD AS WELL...WITH NO SIGNIFICANT DIFFERENCES OBSERVED IN THE RECENT MODEL RUNS (AND ONLY SMALL CHANGES MADE TO THE GOING FORECAST). WITH THE ILN CWA LOOKING TO BE ON THE WEST SIDE OF THE BUILDING RIDGE (AND ASSOCIATED SURFACE HIGH)...SUCH A PATTERN WILL FAVOR SOUTHERLY FLOW. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... CDFNT HAS PUSHED E OF THE TAFS...WITH MVFR AND IFR CONDITIONS AFFECTING THE TAFS AT THE BEGINNING OF THE PERIOD. POST FRONTAL PCPN SHOULD END FROM W TO E OVER THE NEXT FEW HOURS...WITH VSBYS IMPROVING...BUT CIGS ARE EXPECTED TO STAY MVFR THROUGH ABOUT 00Z...WHEN THE BACK EDGE OF THE CLOUDS ARE FORECAST TO REACH THE WRN TAFS. THE CLOUDS SHOULD THEN CLEAR FROM W TO E BETWEEN 00Z- 04Z. CLEAR SKIES AND WEAKENING WINDS SHOULD COMBINE TO ALLOW SOME MVFR FOG DEVELOPMENT TOWARDS SUNRISE 10-12Z THURSDAY. AFTER 12Z...CLOUDS AHEAD OF ANOTHER...BUT WEAKER CDFNT WILL SWING INTO THE REGION. RIGHT NOW THEY LOOK LIKE THEY WILL STAY VFR. SOME MODELS ARE TRYING TO DROP SOME LIGHT PCPN INTO THE NRN TAFS...BUT AT THIS TIME THINK THE CHC IS TOO LOW TO MENTION IN THE TAFS. OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...FROST ADVISORY FROM 2 AM TO 9 AM EDT THURSDAY FOR OHZ034-035- 042>044-051>053-060>063-070>073-077>082-088. FREEZE WARNING FROM 2 AM TO 9 AM EDT THURSDAY FOR OHZ026-045- 046-054>056-064-065-074. KY...FROST ADVISORY FROM 2 AM TO 9 AM EDT THURSDAY FOR KYZ089>100. IN...FROST ADVISORY FROM 2 AM TO 9 AM EDT THURSDAY FOR INZ050-058- 059-066-073>075-080. && $$ SYNOPSIS...HICKMAN NEAR TERM...HICKMAN SHORT TERM...HICKMAN LONG TERM...HATZOS AVIATION...SITES
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
758 AM EDT WED APR 24 2013 .SYNOPSIS... A COLD FRONT WILL MOVE ACROSS THE AREA THIS MORNING. A WEAK TROF WILL MOVE ACROSS THE REGION ON THURSDAY. HIGH PRESSURE WILL BUILD INTO THE AREA THURSDAY NIGHT AND MOVE EAST FRIDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE COLD FRONT IS MOVING SLOWER THAN EXPECTED. AT DAYBREAK IT WAS OVER THE TOLEDO AREA. BY MID MORNING IT SHOULD BE LOCATED NEAR A CLEVELAND TO MARION LINE AND THEN BY EARLY AFTERNOON IT WILL BE EAST OF ERIE AND YOUNGSTOWN. THE SHOWERS WILL BECOME NUMEROUS AGAIN BOTH AHEAD OF AND BEHIND THE FRONT. ANY THUNDER WILL BE ISOLATED AND MAINLY EAST OF MFD AND SOUTH OF CAK THIS MORNING JUST AHEAD OF THE FRONT. MADE SOME MINOR CHANGES TO INCLUDE THE SHOWERS A LITTLE LONGER THIS AFTERNOON OVER NORTHWEST OHIO WITH PLENTY OF OMEGA AND MOISTURE IT WILL HANG AROUND. THE MODELS INCLUDING THE HRRR AND THE 4KM WRF-NMM 00Z AGREE WITH THAT. WITH THE SLOWER MOVEMENT OF THE FRONT HAD TO ADJUST THE TEMPERATURES. NONE THE LESS THEY WILL BE FALLING. THE TEMPERATURES OVER NORTHWEST OHIO COULD RECOVER LATE IN THE AFTERNOON. QPF FOR THIS EVENT WILL BE UNDER AN INCH. NOT EXPECTING ANY FLOODING PROBLEMS...HOWEVER...RIVER AND CREEKS WILL RISE SOME...BUT MOST WILL REMAIN BELOW BANKFULL. IN MOST AREAS THE GROUND IS DRY AND WITH THE TREES BUDDING THIS WILL HELP KEEP THE GROUND FROM BECOMING TOO SATURATED. THE HPC QPF COULD BE A LITTLE HIGH...ADJUSTED IT DOWN SOME. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... SOME SHOWERS WILL LINGER IN THE EVENING OVER NE OHIO AND NW PA. THE CLOUDS WILL DECREASE BUT WITH THE LAKE AND 850 MB TEMPERATURE DIFFERENCE NEAR 11C LATE TONIGHT SOME LAKE EFFECT CLOUDS MAY OCCUR IN THE SNOW BELT AREAS...THE MODELS DON`T THINK THIS WILL HAPPEN. USED A BLEND OF GUIDANCE FOR THE LOWS. A WEAK TROF WILL MOVE THROUGH ON THURSDAY. KEPT THE POPS UNDER 50 PERCENT. THE QUESTION IS HOW MUCH MOISTURE WILL BE WITH THIS TROF. THE MODELS ARE NOT IN AGREEMENT...THE ECMWF IS MUCH DRIER THAN THE NAM AND GFS. NONE THE LESS THE QPF WILL BE LIGHT...GENERALLY UNDER A TENTH OF AN INCH. TENDED TOWARD A LITTLE MORE MOISTURE BUT KEPT THE WORDING CHANCE FOR THE TIME BEING. HIGH PRESSURE WILL BUILD IN THURSDAY NIGHT AND MOVE EAST FRIDAY NIGHT. SOME CLOUDS WILL OCCUR SATURDAY AS A WEATHER SYSTEM MOVES THROUGH THE OHIO VALLEY. && .LONG TERM /SUNDAY THROUGH TUESDAY/... SPLIT FLOW WILL BE IN PLACE ACROSS NORTH AMERICA OVER THE WEEKEND WITH MOISTURE SPREADING NORTH FROM THE GULF OF MEXICO AHEAD OF SHORTWAVE ENERGY APPROACHING FROM THE FOUR CORNERS REGION. THE MOISTURE WILL PUSH NORTH ON SUNDAY AND LINGER THROUGH MONDAY WITH A LOW CHANCE OF SHOWERS BOTH DAYS. THERE WILL BE SOME MARGINAL INSTABILITY BUT FORCING IS PRETTY WEAK AND WILL LEAVE THUNDERSTORMS OUT OF THE FORECAST FOR NOW. OTHERWISE TEMPERATURES WILL BE FAIRLY MILD WITH THE DIURNAL SPREAD DAMPENED BY THE MOISTURE AND CLOUDS. HIGHS GENERALLY IN THE LOW 60S AND LOWS NEAR 50. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... A COLD FRONT CONTINUES TO MAKE SLOW PROGRESS ACROSS THE AREA AND HAS ALREADY CLEARED TOL/FDY AS OF 12Z. SHOWERS WILL CONTINUE INTO THIS AFTERNOON WITH ISOLATED THUNDERSTORMS POSSIBLE. CONDITIONS AHEAD OF THE FRONT ARE GENERALLY VFR...DROPPING TO IFR WITH A WIND SHIFT TO THE NORTHWEST WITH THE FRONTAL PASSAGE. HAVE SLOWED DOWN THE TIMING OF THE FRONT...NOW EXPECTED TO REACH CLE/MFD AROUND 15Z AND YNG/CAK/ERI BETWEEN 17-18Z. A RIDGE WILL BUILD INTO THE AREA THIS EVENING AND MODELS ARE PRETTY AGRESSIVE AT CLEARING SKIES OUT. THERE IS SOME UNCERTAINTY ABOUT THE CLEARING TREND THOUGH AND WILL HAVE TO KEEP AN EYE ON UPSTREAM TRENDS TODAY. .OUTLOOK...NON- VFR POSSIBLE THURSDAY AND AGAIN SUNDAY. && .MARINE... A COLD FRONT WILL MOVE ACROSS LAKE ERIE THROUGH EARLY AFTERNOON WITH WINDS SHIFTING TO THE NORTHWEST AT 15 TO 20 KNOTS. WAVES WILL BUILD TO 2 TO 4 FEET IN THE NEARSHORE WATERS AS THE FLOW BECOMES ONSHORE AND MAY BRIEFLY APPROACH SMALL CRAFT ADVISORY CRITERIA IN THE PENNSYLVANIA WATERS FOR A FEW HOURS THIS EVENING. WILL ALLOW THE DAY SHIFT TO MONITOR WINDS AND ISSUE THE SMALL CRAFT FOR A BRIEF WINDOW IF NEEDED. A RIDGE WILL BUILD IN BEHIND THE FRONT OVERNIGHT WITH WINDS DECREASING BELOW 15 KNOTS. SOUTHERLY WINDS WILL RAMP UP AGAIN ON THURSDAY AHEAD OF ANOTHER COLD FRONT APPROACHING THE AREA FROM THE WEST. THE FRONT WILL CROSS THE LAKE THURSDAY AFTERNOON WITH WINDS SHIFTING TO WESTERLY. HIGH PRESSURE WILL BUILD OVER THE OHIO VALLEY ON FRIDAY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KIELTYKA NEAR TERM...KIELTYKA SHORT TERM...KIELTYKA LONG TERM...KEC AVIATION...KEC MARINE...KEC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
702 AM EDT WED APR 24 2013 .SYNOPSIS... A COLD FRONT WILL MOVE ACROSS THE AREA THIS MORNING. A WEAK TROF WILL MOVE ACROSS THE REGION ON THURSDAY. HIGH PRESSURE WILL BUILD INTO THE AREA THURSDAY NIGHT AND MOVE EAST FRIDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE COLD FRONT IS MOVING SLOWER THAN EXPECTED. AT DAYBREAK IT WAS OVER THE TOLEDO AREA. BY MID MORNING IT SHOULD BE LOCATED NEAR A CLEVELAND TO MARION LINE AND THEN BY EARLY AFTERNOON IT WILL BE EAST OF ERIE AND YOUNGSTOWN. THE SHOWERS WILL BECOME NUMEROUS AGAIN BOTH AHEAD OF AND BEHIND THE FRONT. ANY THUNDER WILL BE ISOLATED AND MAINLY EAST OF MFD AND SOUTH OF CAK THIS MORNING JUST AHEAD OF THE FRONT. MADE SOME MINOR CHANGES TO INCLUDE THE SHOWERS A LITTLE LONGER THIS AFTERNOON OVER NORTHWEST OHIO WITH PLENTY OF OMEGA AND MOISTURE IT WILL HANG AROUND. THE MODELS INCLUDING THE HRRR AND THE 4KM WRF-NMM 00Z AGREE WITH THAT. WITH THE SLOWER MOVEMENT OF THE FRONT HAD TO ADJUST THE TEMPERATURES. NONE THE LESS THEY WILL BE FALLING. THE TEMPERATURES OVER NORTHWEST OHIO COULD RECOVER LATE IN THE AFTERNOON. QPF FOR THIS EVENT WILL BE UNDER AN INCH. NOT EXPECTING ANY FLOODING PROBLEMS...HOWEVER...RIVER AND CREEKS WILL RISE SOME...BUT MOST WILL REMAIN BELOW BANKFULL. IN MOST AREAS THE GROUND IS DRY AND WITH THE TREES BUDDING THIS WILL HELP KEEP THE GROUND FROM BECOMING TOO SATURATED. THE HPC QPF COULD BE A LITTLE HIGH...ADJUSTED IT DOWN SOME. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... SOME SHOWERS WILL LINGER IN THE EVENING OVER NE OHIO AND NW PA. THE CLOUDS WILL DECREASE BUT WITH THE LAKE AND 850 MB TEMPERATURE DIFFERENCE NEAR 11C LATE TONIGHT SOME LAKE EFFECT CLOUDS MAY OCCUR IN THE SNOW BELT AREAS...THE MODELS DON`T THINK THIS WILL HAPPEN. USED A BLEND OF GUIDANCE FOR THE LOWS. A WEAK TROF WILL MOVE THROUGH ON THURSDAY. KEPT THE POPS UNDER 50 PERCENT. THE QUESTION IS HOW MUCH MOISTURE WILL BE WITH THIS TROF. THE MODELS ARE NOT IN AGREEMENT...THE ECMWF IS MUCH DRIER THAN THE NAM AND GFS. NONE THE LESS THE QPF WILL BE LIGHT...GENERALLY UNDER A TENTH OF AN INCH. TENDED TOWARD A LITTLE MORE MOISTURE BUT KEPT THE WORDING CHANCE FOR THE TIME BEING. HIGH PRESSURE WILL BUILD IN THURSDAY NIGHT AND MOVE EAST FRIDAY NIGHT. SOME CLOUDS WILL OCCUR SATURDAY AS A WEATHER SYSTEM MOVES THROUGH THE OHIO VALLEY. && .LONG TERM /SUNDAY THROUGH TUESDAY/... SPLIT FLOW WILL BE IN PLACE ACROSS NORTH AMERICA OVER THE WEEKEND WITH MOISTURE SPREADING NORTH FROM THE GULF OF MEXICO AHEAD OF SHORTWAVE ENERGY APPROACHING FROM THE FOUR CORNERS REGION. THE MOISTURE WILL PUSH NORTH ON SUNDAY AND LINGER THROUGH MONDAY WITH A LOW CHANCE OF SHOWERS BOTH DAYS. THERE WILL BE SOME MARGINAL INSTABILITY BUT FORCING IS PRETTY WEAK AND WILL LEAVE THUNDERSTORMS OUT OF THE FORECAST FOR NOW. OTHERWISE TEMPERATURES WILL BE FAIRLY MILD WITH THE DIURNAL SPREAD DAMPENED BY THE MOISTURE AND CLOUDS. HIGHS GENERALLY IN THE LOW 60S AND LOWS NEAR 50. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... AT 06Z A COLD FRONT EXTENDED FROM KFNT-KFWA. SHOWERS WERE SPREADING EAST AHEAD OF THE FRONT WITH MOST LOCATIONS STARTING OFF WITH VFR CEILINGS AND OCCASIONAL MVFR VISIBILITIES IN SOME OF THE HEAVIER SHOWERS. THE FRONT IS MAKING SLOW PROGRESS BUT WILL REACH TOL AROUND 09Z AND CLE AROUND 12Z. SOUTHERLY WINDS AHEAD OF THE FRONT WILL BECOME LIGHT...THEN SHIFT TO NORTHWEST AND BECOME BREEZY. CONDITIONS WILL DETERIORATE BEHIND THE FRONT TO IFR IN MOST AREAS WITH SOME POCKETS OF LOW IFR...AS REPORTED ON UPSTREAM OBSERVATIONS. SHOWERS WILL CONTINUE THROUGH AT LEAST 18Z...THEN ENDING FROM WEST TO EAST DURING THE AFTERNOON. HIGH PRESSURE QUICKLY BUILDS IN FROM THE SOUTHWEST ON WEDNESDAY EVENING WITH SKIES EXPECTED TO SCATTER OUT BETWEEN 00-06Z. .OUTLOOK...NON- VFR POSSIBLE THURSDAY AND AGAIN SUNDAY. && .MARINE... A COLD FRONT WILL MOVE ACROSS LAKE ERIE THROUGH EARLY AFTERNOON WITH WINDS SHIFTING TO THE NORTHWEST AT 15 TO 20 KNOTS. WAVES WILL BUILD TO 2 TO 4 FEET IN THE NEARSHORE WATERS AS THE FLOW BECOMES ONSHORE AND MAY BRIEFLY APPROACH SMALL CRAFT ADVISORY CRITERIA IN THE PENNSYLVANIA WATERS FOR A FEW HOURS THIS EVENING. WILL ALLOW THE DAY SHIFT TO MONITOR WINDS AND ISSUE THE SMALL CRAFT FOR A BRIEF WINDOW IF NEEDED. A RIDGE WILL BUILD IN BEHIND THE FRONT OVERNIGHT WITH WINDS DECREASING BELOW 15 KNOTS. SOUTHERLY WINDS WILL RAMP UP AGAIN ON THURSDAY AHEAD OF ANOTHER COLD FRONT APPROACHING THE AREA FROM THE WEST. THE FRONT WILL CROSS THE LAKE THURSDAY AFTERNOON WITH WINDS SHIFTING TO WESTERLY. HIGH PRESSURE WILL BUILD OVER THE OHIO VALLEY ON FRIDAY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KIELTYKA NEAR TERM...KIELTYKA SHORT TERM...KIELTYKA LONG TERM...KEC AVIATION...KEC MARINE...KEC
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1102 AM EDT WED APR 24 2013 .SYNOPSIS... A COLD FRONT OVER THE LOWER GREAT LAKES AND UPPER OHIO VALLEY THIS MORNING WILL PUSH EAST ACROSS CENTRAL PENNSYLVANIA THIS AFTERNOON AND EVENING. THE COLD FRONT WILL BE ACCOMPANIED BY A LINE OF SHOWERS AND SCATTERED THUNDERSTORMS. AN UPPER-LEVEL TROUGH WILL MOVE THROUGH THE GREAT LAKES ON THURSDAY WITH SCATTERED RAIN OR EVEN SNOW SHOWERS POSSIBLE OVER THE NORTHWEST MOUNTAINS. HIGH PRESSURE WILL PROVIDE FAIR WEATHER FRIDAY INTO THE WEEKEND. && .NEAR TERM /UNTIL 9 PM THIS EVENING/... THICK BAND OF MID LEVEL CLOUDS MOVING ACROSS C PA THIS MORNING KEEPING TEMPS A LITTLE COOLER THEN FORECAST AND ADJUSTED ACCORDINGLY. VIS SAT SHOWS A BRIEF BREAK IN THE CLOUDS BEFORE NEXT BAND ASSOCIATED WITH THE FRONT APPROACHES THIS AFTERNOON. SHORT RANGE MODELS ALL IN GOOD AGREEMENT WITH THE TIMING OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON. LATEST RAP DCAPE SHOWS WEDGE OF HIGHER CAPES IN ADVANCE OF PRECIP SHIELD SO EXPECT SOME POTENTIAL STRONG STORMS AND POSSIBLE BOW ECHO TYPE STORMS ESPECIALLY OVER SOUTHERN COUNTIES AFT 22Z. COOL SURFACE DP AND CLOUD COVER AHEAD OF PRECIP WILL LIMIT SURFACE INSTABILITY AND LIKELY PREVENT A MORE WIDESPREAD EVENT. AS PREVIOUS DISCUSSION NOTES THE INGREDIENTS SEEM TO BE IN PLACE FOR A LOW TOPPED SQUALL LINE/NCFRB TO IMPACT MAINLY THE SOUTHERN CWA LATE THIS AFTN/EVE WITH BRIEF HEAVY RAIN AND POTENTIAL FOR SEVERE TSTM WIND GUSTS. THE SPC DAY 1 OUTLOOK HIGHLIGHTS PORTIONS OF THE AREA FOR LOW PROBS FOR DMGG WINDS. WILL CONTINUE EMPHASIZE THE POTENTIAL DMGG WIND THREAT IN THE HWO. && .SHORT TERM /9 PM THIS EVENING THROUGH 6 AM THURSDAY/... GUSTY WESTERLY FLOW BEHIND THE FRONT WILL USHER COOLER AIR BACK INTO CENTRAL PA FOR TONIGHT...WITH LOWS NEAR THE FREEZING MARK IN THE NRN MTNS. ALSO CAN/T RULE OUT POST-FRONTAL RAIN/SNOW SHOWERS ACRS THE WRN ALLEGHENIES. && .LONG TERM /THURSDAY THROUGH TUESDAY/... BROAD UPPER TROFFING OVER THE EASTERN U.S. WILL TRANSITION TO FAST ZONAL FLOW BY THE START OF THE LONG TERM PERIOD...WITH UPPER RIDGING BUILDING OVER THE EAST COAST BY THE MIDDLE OF NEXT WEEK. AREAS SE OF THE ALLEGHENY FRONT WILL SEE THE CHILL MODIFIED BY THE DESCENDING NW TO NRLY FLOW. HIGH TEMPS WILL BE JUST A FEW TO SVRL DEG F BELOW NORMAL BOTH THURSDAY AND FRIDAY. HIGH PRESSURE WILL COVER THE ENTIRE THIRD OF THE CONUS THURSDAY AND FRIDAY BEFORE SLOWLY MOVING OFFSHORE BY SUNDAY. PLENTY OF SUNSHINE IS EXPECTED FOR THE CENTRAL AND SE VALLEYS...WHILE BKN- OVC SKIES RESIDE ACROSS THE NW MTNS. FRIDAY AND MUCH OF SATURDAY CONTINUES TO LOOK DRY. THE SECOND HALF OF THE WEEKEND IS IN DOUBT HOWEVER GIVEN CONTINUED WIDE SPREAD IN SOLUTIONS REGARDING THE IMPACT OF INCREASING EASTERLY FLOW OVER THE COASTAL MID ATLANTIC AND HOW MUCH LLVL MOISTURE MAY ADVECT TOWARDS THE MASON DIXON LINE AND POINTS NORTHWARD. LATEST ECMWF KEEPS CENTRAL AND EASTERN AREAS DRY...WITH A RETURN FLOW OF MOISTURE AND SLIGHTLY ANOMALOUS PW PRODUCING AT LEAST A SMALL CHANCE OF SHOWERS OVER EASTERN OHIO AND WESTERN PA SUNDAY AFTERNOON WHICH COULD LINGER ON MONDAY. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... 24/12Z... IFR-MVFR CIGS AND VISBYS HAVE DEVELOPED ACRS THE ERN TERMINALS AND SHOULD PERSIST THRU 14-15Z. THE MAIN AVIATION CONCERN WILL BE THE COLD FROPA EXPECTED TO IMPACT THE AIRSPACE FROM LATER THIS AFTN THRU THE EVE HOURS. A SW-NE ORIENTED BAND OF SHOWERS WITH EMBEDDED TSTMS SHOULD DEVELOP ALONG/NEAR THE EWD ADVANCING COLD FRONT OVER WRN PA...AND ORGANIZE INTO A STRONGLY FORCED LOW-TOPPED CONVECTIVE LINE - POSING AT LEAST SOME THREAT FOR STG WIND GUSTS - AS IT CROSSES CNTRL AND ERN SXNS. CONFIDENCE IN TSTM IMPACTS IS INCREASING...WITH THE HI-RES MDL DATA ALL IN GOOD AGREEMENT. EXPECT MVFR TO LCL IFR VIS IN MOD- HVY SHRA/ISOLD TSRA WITH LOW END VFR TO MVFR CIGS. GUSTY POST- FRONTAL/WESTERLY FLOW REGIME TONIGHT WILL LKLY FEATURE MVFR CIGS ACRS WRN TAFS WITH VFR CONDS PREVAILING E OF THE MTNS. .OUTLOOK... THU...SCT -SHRA/MVFR CIGS NW. VFR ELSEWHERE. FRI-SAT...NO SIG WX. SUN...VFR. ISOLD PM -SHRA PSBL WEST. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...ROSS/STEINBUGL NEAR TERM...ROSS/STEINBUGL SHORT TERM...ROSS/STEINBUGL LONG TERM...DEVOIR/GARTNER AVIATION...ROSS/STEINBUGL
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
141 PM EDT WED APR 24 2013 .SYNOPSIS... A COLD FRONT WILL SLOWLY CROSS THE WESTERN CAROLINAS AND NORTHEAST GEORGIA TONIGHT. MILD HIGH PRESSURE WILL THEN BUILD IN BEHIND THE FRONT FOR THURSDAY AND FRIDAY. A SLOW MOVING AREA OF LOW PRESSURE WILL DEVELOP OVER THE SOUTHERN PLAINS FRIDAY NIGHT AND DRIFT NORTHEASTWARD THROUGH THE WEEKEND. && .NEAR TERM /THROUGH THURSDAY/... AT 125 PM...MAIN ADJUSTMENT IS TO LOWER MAX TEMPS SEVERAL DEGREES DUE TO CLOUD COVER. POP TRENDS ARE STILL ON TARGET AS THE FRONTAL BAND OF PRECIP IS NOW OVER EASTERN TN AND WILL ENTER NC BORDER COUNTIES BY 19Z. THERE HAS BEEN A NOTICABLE DECREASE IN LIGHTNING ACTIVITY AND HAVE LOWERED PROB OF THUNDER TO JUST CHANCE IN THE MOUNTAINS. PREVIOUS DISCUSSION: AT 1040 EDT...STRATUS FIELD OVER THE UPSTATE AND SOUTHERN NC PIEDMONT SHRINKING AND ADVECTING TO THE N. IT SHOULD BE GONE BY MIDDAY. HOWEVER...CLOUDS IN ADVANCE OF THE COLD FRONT TO THE WEST OVER ERN TN ENCROACHING QUICKLY FROM THE W. CURRENT SKY GRID HANDLES THIS WELL. 12Z NAM SILL SUPPORTS BRINGING NUMEROUS SHOWERS/TSTORMS INTO THE TN BORDER COUNTIES BY MID AFTERNOON. HOWEVER...IT CONTINUES THE PREVIOUS FORECAST TRENDS THAT WEAKENS AND SCATTERS OUT THE CONVECTION AS IT MOVES OUT OF THE MOUNTAINS LATE THIS AFTERNOON INTO THIS EVENING. HAVE MAINTAINED THE CHANCE OF THUNDER OVER THE WESTERN HALF OF THE AREA INTO THIS EVENING...BUT THUNDER CHANCES QUICKLY DIMINISH AFTER 00Z. 1130 UTC UPDATE...ONLY CHANGES WERE A FEW TWEAKS TO THE AVIATION GRIDS FOR THE 12Z TAFS. SKY GRIDS LOOK TO BE ROUGHLY IN LINE WITH CURRENT SAT/OBS. AS OF 515 AM...THE SKY GRIDS WERE UPDATED TO REFLECT ENCROACHING LOW STRATUS FROM THE SOUTH. THE 08Z RAP SEEMS TO BE INITIALIZING THE CLOUDS FAIRLY WELL AND SO IT WAS USED TO REFLECT TRENDS IN THE CLOUDS THRU MID MORNING. BASICALLY...IT LOOKS LIKE THE CLOUDS WILL REACH ROUGHLY TO I-85 AROUND OR SHORTLY AFTER DAYBREAK...EXTENDING NE TOWARD THE TRIAD. FROM THERE IT SHUD DISSIPATE AS INSOLATION MIXES THE INVERSION/SHALLOW MOISTURE OUT BY MIDDAY. MEANWHILE...STRATUS DECK (AROUND 5000 FT) CONTINUES TO WORK INTO THE SW NC MTNS AND NE GA FROM THE WEST. OVERALL...STILL EXPECTING SOME SUNSHINE BEFORE THICKER CLOUDS FINALLY OVERTAKE THE SKIES BY MID/LATE AFTN AS A COLD FRONT WORKS INTO THE AREA. NO OTHER CHANGES WERE MADE. AS OF 300 AM...A COLD FRONT WAS ANALYZED CROSSING OHIO VALLEY...WITH CONVECTION INCREASING IN COVERAGE ALONG AND AHEAD OF THE BNDRY. MODELS ARE IN GOOD AGREEMENT ON UPR LVL FORCING LAGGING BEHIND THE FRONT TODAY...WITH THE FRONT LOSING ITS PUNCH AS IT ENTERS THE NC MTNS THIS AFTN. FCST SNDGS ACRS THE PIEDMONT SHOW A SUBSIDENCE INVERSION THAT IS SLOW TO ERODE THIS AFTN/EVE...RESULTING IN GENERALLY LESS THAN 500 J/KG OF CAPE. TAKING A BLEND OF THE GFS AND NAM FOR CAPE...I ONLY GET CHC THUNDER IN THE MTNS WITH NO MENTION ACRS THE PIEDMONT. OVERALL...A MODEL BLEND OF THE POPS RESULTS IN A CUT BACK FROM PREV FCST. ALL IN ALL...EXPECTING MAINLY GARDEN VARIETY SHWRS/TSTMS IN THE MTNS THIS AFTN AND GENERALLY WIDELY SCT SHWRS ACRS THE ENTIRE AREA THIS EVENING...TAPERING OFF OVERNIGHT FROM NW TO SE. WITH THE FRONT HAVING AN ANAFRONT STRUCTURE...UPGLIDE BEHIND THE SFC BNDRY MAY RESULT IN LINGERING SHWRS ALONG AND SOUTH OF I-85 RIGHT UP TILL DAYBREAK. TEMPS SHUD BE ABLE TO WARM TO ABOVE NORMAL READINGS EAST OF THE MTNS...AS THICKER CLOUDS AND MOISTURE DOESN/T ENTER THE AREA TILL AFTER PEAK HEATING. LOWS OVERNIGHT NEAR NORMAL. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/... AS OF 235 AM EDT WEDNESDAY...THE LATEST NAM AND GFS RUNS CLEAR OUT CLOUD COVER BY ABOUT MID-MORNING ON THURSDAY. AS I DON/T THINK WE WILL SEE THAT MUCH PCPN INTO THE PRE-FRONTAL AIRMASS OVER THE FOOTHILLS AND PIEDMONT...I SUSPECT THAT LOW CLOUDS WON/T BE IN ABUNDANCE IN THE FIRST PLACE. IT WILL BE A NICE AFTERNOON WITH CLEAR...BLUE SKIES AND MAX TEMPS A COUPLE CATEGORIES BELOW NORMAL. FROST STILL APPEARS LIKE A GOOD BET OVER THE NC MTNS AND POSSIBLY THE WRN FOOTHILLS THURSDAY NIGHT. I/VE INCREASED THE AREAL COVERAGE OF FROST IN THE WEATHER GRIDS TO ACCOUNT FOR THIS. SOME OF THE TYPICAL COLD SPOTS AND/OR SHELTERED VALLEYS WILL WILL PROBABLY FALL TO FREEZING. FRIDAY WILL ALSO BE A NICE DAY...THOUGH MID AND HIGH LEVEL CLOUD COVER WILL INCREASE DURING THE AFTERNOON HOURS AHEAD OF A SOUTHERN STREAM SHORT WAVE. DESPITE THE HIGH CLOUDS...TEMPERATURES SHOULD BE A FEW DEGREES WARMER THAN THURSDAY/S HIGHS. FRIDAY NIGHT CLOUDS WILL CONTINUE TO THICKEN AND LOWER AND THERE WILL BE A CHANCE OF RAIN LATER AT NIGHT...ESPECIALLY OVER THE MOUNTAINS. THE PCPN WILL BE FORCED AS THE WRN CAROLINAS AND NE GA WILL BE IN THE RT ENTRANCE REGION OF A 110 KT UPPER JET CENTERED OVER ERN NC. A SRN STREAM JET MOVING ACROSS THE DEEP SOUTH MAY ALSO CONTRIBUTE SOME LIFT TO THE SYSTEM. THE SFC COLD FRONT WILL BE WELL TO OUR SOUTH...DOWN ALONG THE GULF COAST. THEREFORE THE PCPN SHOULD BE HIGH BASED AND MORE STRATIFORM IN NATURE. ANY STRONG LLVL WARM ADVECTION STAYS WELL SOUTHWEST OF THE REGION...CLOSER TO THE SFC-H8 FRONT...SO PCPN SHOULD BE LIGHT. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 300 AM EDT WEDNESDAY...THE LATEST WPC EXTENDED DISCUSSION FAVORS THE 12 UTC ECMWF FOR THE SAT-TUE PERIOD. LOOKING AT THEIR EXTENDED RANGE GUIDANCE...THEY HAVE LIKELY POPS ON SATURDAY AND SOLID CHANCE POPS SUN-TUE. WHILE THE LATEST GFS IS WEAKER WITH THE FORCING...IT/S STILL IN PRETTY GOOD AGREEMENT WITH THE 12 UTC RUN OF THE EC IN BRINGING A SRN STREAM SHORT WAVE SLOWLY ACROSS THE REGION OVER THE WEEKEND. UPGLIDE WILL INCREASE OVER A LLVL FRONTAL BNDRY...BRINGING PCPN TO THE REGION. HOWEVER...THERE HAS BEEN A TREND IN THE MODELS TO DEVELOP THE PCPN FARTHER SOUTH. THIS MAKES A LOT OF SENSE TO ME AS A BELT OF STRONG MID-TROPOSPHERE FLOW WILL EXIST DOWN TOWARD THE GOM. THE SFC BNDRY WILL LIKELY HAVE A DIFFICULT TIME LIFTING NORTH OF THIS BAROCLINIC ZONE ALOFT...AND I CAN SEE QUITE A BIT OF CONVECTION AND PCPN DEVELOPING DOWN TOWARD THE GULF...ESPECIALLY AS WE GET INTO SUNDAY. MONDAY AND TUESDAY THE SRN STREAM IS EVEN STRONGER AND FURTHER SOUTH AS A MID-LATITUDE H5 RIDGE BEGINS TO DEVELOP OVER THE TN RIVER VALLEY. THIS BLOCKING RIDGE PROVIDES A BROAD SEPARATION BETWEEN THE NRN STREAM SHOOTING ACROSS THE NRN PLAINS AND THE SRN STREAM DOWN ACROSS THE NRN GOM. WHILE WE WOULD CERTAINLY SEE SOME PCPN FROM THIS PATTERN...I SUSPECT THAT MOST OF THE PCPN INTO MON AND TUE WILL REMAIN SOUTH OF THE FORECAST AREA. THAT IS IF THIS PARTICULAR PATTERN DOES EVOLVE. THIS IS NOT A HIGH CONFIDENCE FORECAST...AND I/M NOT GOING TO DO ANYTHING DRAMATIC TO THE POPS ON THIS SHIFT. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... AT KCLT...SCT CLOUDS IN THE 040-060 RANGE ARE IN STORE FOR EARLY THIS AFTERNOON WITH BKN-OVC040 DEVELOPING ABOUT 21Z AS A COLD FRONT APPROACHES FROM THE WEST. PRECIP ASSOCIATED WITH FRONT IS EXPECTED TO DISSIPATE AS IT MOVES EAST OF THE MOUNTAINS WITH ONLY SCT LIGHT SHOWERS AT BEST IN THE VICINITY OF THE AIRFIELD. EXPECT FRONTAL PASSAGE CIRCA 03Z WITH WINDS GOING FROM SW-NW. VCSH 00Z-03Z WITH ONLY MINOR RESTRICTIONS AT BEST WITH ANY SHOWERS. VFR CEILINGS WILL SCATTER OUT BY 12Z. ELSEWHERE...A COLD FRONT WILL MOVE ACROSS THE WESTERN CAROLINAS FROM LATE AFTERNOON INTO TONIGHT. NUMEROUS SHOWERS AND EMBEDDED THUNDERSTORMS WILL INTIALLY ENTER THE NC MOUNTAINS...BUT TEND TO DISSIPATE AS THEY MOVE EAST OF THE MOUNTAINS AFTER SUNSET. CARRIED A TEMPO AT KAVL FROM 22-24Z WITH MVFR RESTRICTIONS. OTHERWISE VCSH WITH ONLY MINOR RESTRICTIONS AT BEST OTHER AIRFIELDS. VFR CEILINGS WILL PREDOMINATE WITH CLOUDS SCATTERING OUT BY 12Z. OUTLOOK...VFR CONDITIONS ARE EXPECTED THROUGH FRIDAY. THE NEXT SYSTEM WILL BRING MOISTURE BACK INTO THE AREA FRIDAY NIGHT THRU THE WEEKEND ALONG WITH POSSIBLE RESTRICTIONS. CONFIDENCE TABLE... 17-23Z 23-05Z 05-11Z 11-17Z KCLT HIGH 100% HIGH 100% HIGH 89% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 98% HIGH 100% KAVL HIGH 100% HIGH 84% HIGH 87% MED 60% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 98% HIGH 100% KAND HIGH 100% HIGH 93% LOW 58% LOW 57% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...JOH NEAR TERM...LG SHORT TERM...MCAVOY LONG TERM...MCAVOY AVIATION...LG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1043 AM EDT WED APR 24 2013 .SYNOPSIS... A COLD FRONT WILL SLOWLY CROSS THE WESTERN CAROLINAS AND NORTHEAST GEORGIA TONIGHT. MILD HIGH PRESSURE WILL THEN BUILD IN BEHIND THE FRONT FOR THURSDAY AND FRIDAY. A SLOW MOVING AREA OF LOW PRESSURE WILL DEVELOP OVER THE SOUTHERN PLAINS FRIDAY NIGHT AND DRIFT NORTHEASTWARD THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AT 1040 EDT...STRATUS FIELD OVER THE UPSTATE AND SOUTHERN NC PIEDMONT SHRINKING AND ADVECTING TO THE N. IT SHOULD BE GONE BY MIDDAY. HOWEVER...CLOUDS IN ADVANCE OF THE COLD FRONT TO THE WEST OVER ERN TN ENCROACHING QUICKLY FROM THE W. CURRENT SKY GRID HANDLES THIS WELL. 12Z NAM SILL SUPPORTS BRINGING NUMEROUS SHOWERS/TSTORMS INTO THE TN BORDER COUNTIES BY MID AFTERNOON. HOWEVER...IT CONTINUES THE PREVIOUS FORECAST TREND THAT WEAKENS AND SCATTERS OUT THE CONVECTION AS IT MOVES OUT OF THE MOUNTAINS LATE THIS AFTERNOON INTO THIS EVENING. HAVE MAINTAINED THE CHANCE OF THUNDER OVER THE WESTERN HALF OF THE AREA INTO THIS EVENING...BUT THUNDER CHANCES QUICKLY DIMINISH AFTER 00Z. PREVIOUS DISCUSSION: 1130 UTC UPDATE...ONLY CHANGES WERE A FEW TWEAKS TO THE AVIATION GRIDS FOR THE 12Z TAFS. SKY GRIDS LOOK TO BE ROUGHLY IN LINE WITH CURRENT SAT/OBS. AS OF 515 AM...THE SKY GRIDS WERE UPDATED TO REFLECT ENCROACHING LOW STRATUS FROM THE SOUTH. THE 08Z RAP SEEMS TO BE INITIALIZING THE CLOUDS FAIRLY WELL AND SO IT WAS USED TO REFLECT TRENDS IN THE CLOUDS THRU MID MORNING. BASICALLY...IT LOOKS LIKE THE CLOUDS WILL REACH ROUGHLY TO I-85 AROUND OR SHORTLY AFTER DAYBREAK...EXTENDING NE TOWARD THE TRIAD. FROM THERE IT SHUD DISSIPATE AS INSOLATION MIXES THE INVERSION/SHALLOW MOISTURE OUT BY MIDDAY. MEANWHILE...STRATUS DECK (AROUND 5000 FT) CONTINUES TO WORK INTO THE SW NC MTNS AND NE GA FROM THE WEST. OVERALL...STILL EXPECTING SOME SUNSHINE BEFORE THICKER CLOUDS FINALLY OVERTAKE THE SKIES BY MID/LATE AFTN AS A COLD FRONT WORKS INTO THE AREA. NO OTHER CHANGES WERE MADE. AS OF 300 AM...A COLD FRONT WAS ANALYZED CROSSING OHIO VALLEY...WITH CONVECTION INCREASING IN COVERAGE ALONG AND AHEAD OF THE BNDRY. MODELS ARE IN GOOD AGREEMENT ON UPR LVL FORCING LAGGING BEHIND THE FRONT TODAY...WITH THE FRONT LOSING ITS PUNCH AS IT ENTERS THE NC MTNS THIS AFTN. FCST SNDGS ACRS THE PIEDMONT SHOW A SUBSIDENCE INVERSION THAT IS SLOW TO ERODE THIS AFTN/EVE...RESULTING IN GENERALLY LESS THAN 500 J/KG OF CAPE. TAKING A BLEND OF THE GFS AND NAM FOR CAPE...I ONLY GET CHC THUNDER IN THE MTNS WITH NO MENTION ACRS THE PIEDMONT. OVERALL...A MODEL BLEND OF THE POPS RESULTS IN A CUT BACK FROM PREV FCST. ALL IN ALL...EXPECTING MAINLY GARDEN VARIETY SHWRS/TSTMS IN THE MTNS THIS AFTN AND GENERALLY WIDELY SCT SHWRS ACRS THE ENTIRE AREA THIS EVENING...TAPERING OFF OVERNIGHT FROM NW TO SE. WITH THE FRONT HAVING AN ANAFRONT STRUCTURE...UPGLIDE BEHIND THE SFC BNDRY MAY RESULT IN LINGERING SHWRS ALONG AND SOUTH OF I-85 RIGHT UP TILL DAYBREAK. TEMPS SHUD BE ABLE TO WARM TO ABOVE NORMAL READINGS EAST OF THE MTNS...AS THICKER CLOUDS AND MOISTURE DOESN/T ENTER THE AREA TILL AFTER PEAK HEATING. LOWS OVERNIGHT NEAR NORMAL. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 235 AM EDT WEDNESDAY...THE LATEST NAM AND GFS RUNS CLEAR OUT CLOUD COVER BY ABOUT MID-MORNING ON THURSDAY. AS I DON/T THINK WE WILL SEE THAT MUCH PCPN INTO THE PRE-FRONTAL AIRMASS OVER THE FOOTHILLS AND PIEDMONT...I SUSPECT THAT LOW CLOUDS WON/T BE IN ABUNDANCE IN THE FIRST PLACE. IT WILL BE A NICE AFTERNOON WITH CLEAR...BLUE SKIES AND MAX TEMPS A COUPLE CATEGORIES BELOW NORMAL. FROST STILL APPEARS LIKE A GOOD BET OVER THE NC MTNS AND POSSIBLY THE WRN FOOTHILLS THURSDAY NIGHT. I/VE INCREASED THE AREAL COVERAGE OF FROST IN THE WEATHER GRIDS TO ACCOUNT FOR THIS. SOME OF THE TYPICAL COLD SPOTS AND/OR SHELTERED VALLEYS WILL WILL PROBABLY FALL TO FREEZING. FRIDAY WILL ALSO BE A NICE DAY...THOUGH MID AND HIGH LEVEL CLOUD COVER WILL INCREASE DURING THE AFTERNOON HOURS AHEAD OF A SOUTHERN STREAM SHORT WAVE. DESPITE THE HIGH CLOUDS...TEMPERATURES SHOULD BE A FEW DEGREES WARMER THAN THURSDAY/S HIGHS. FRIDAY NIGHT CLOUDS WILL CONTINUE TO THICKEN AND LOWER AND THERE WILL BE A CHANCE OF RAIN LATER AT NIGHT...ESPECIALLY OVER THE MOUNTAINS. THE PCPN WILL BE FORCED AS THE WRN CAROLINAS AND NE GA WILL BE IN THE RT ENTRANCE REGION OF A 110 KT UPPER JET CENTERED OVER ERN NC. A SRN STREAM JET MOVING ACROSS THE DEEP SOUTH MAY ALSO CONTRIBUTE SOME LIFT TO THE SYSTEM. THE SFC COLD FRONT WILL BE WELL TO OUR SOUTH...DOWN ALONG THE GULF COAST. THEREFORE THE PCPN SHOULD BE HIGH BASED AND MORE STRATIFORM IN NATURE. ANY STRONG LLVL WARM ADVECTION STAYS WELL SOUTHWEST OF THE REGION...CLOSER TO THE SFC-H8 FRONT...SO PCPN SHOULD BE LIGHT. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 300 AM EDT WEDNESDAY...THE LATEST WPC EXTENDED DISCUSSION FAVORS THE 12 UTC ECMWF FOR THE SAT-TUE PERIOD. LOOKING AT THEIR EXTENDED RANGE GUIDANCE...THEY HAVE LIKELY POPS ON SATURDAY AND SOLID CHANCE POPS SUN-TUE. WHILE THE LATEST GFS IS WEAKER WITH THE FORCING...IT/S STILL IN PRETTY GOOD AGREEMENT WITH THE 12 UTC RUN OF THE EC IN BRINGING A SRN STREAM SHORT WAVE SLOWLY ACROSS THE REGION OVER THE WEEKEND. UPGLIDE WILL INCREASE OVER A LLVL FRONTAL BNDRY...BRINGING PCPN TO THE REGION. HOWEVER...THERE HAS BEEN A TREND IN THE MODELS TO DEVELOP THE PCPN FARTHER SOUTH. THIS MAKES A LOT OF SENSE TO ME AS A BELT OF STRONG MID-TROPOSPHERE FLOW WILL EXIST DOWN TOWARD THE GOM. THE SFC BNDRY WILL LIKELY HAVE A DIFFICULT TIME LIFTING NORTH OF THIS BAROCLINIC ZONE ALOFT...AND I CAN SEE QUITE A BIT OF CONVECTION AND PCPN DEVELOPING DOWN TOWARD THE GULF...ESPECIALLY AS WE GET INTO SUNDAY. MONDAY AND TUESDAY THE SRN STREAM IS EVEN STRONGER AND FURTHER SOUTH AS A MID-LATITUDE H5 RIDGE BEGINS TO DEVELOP OVER THE TN RIVER VALLEY. THIS BLOCKING RIDGE PROVIDES A BROAD SEPARATION BETWEEN THE NRN STREAM SHOOTING ACROSS THE NRN PLAINS AND THE SRN STREAM DOWN ACROSS THE NRN GOM. WHILE WE WOULD CERTAINLY SEE SOME PCPN FROM THIS PATTERN...I SUSPECT THAT MOST OF THE PCPN INTO MON AND TUE WILL REMAIN SOUTH OF THE FORECAST AREA. THAT IS IF THIS PARTICULAR PATTERN DOES EVOLVE. THIS IS NOT A HIGH CONFIDENCE FORECAST...AND I/M NOT GOING TO DO ANYTHING DRAMATIC TO THE POPS ON THIS SHIFT. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... AT KCLT...IFR (EVEN A PERIOD OF LIFR) STRATUS AND FOG TO START THE 12Z TAF. THE CLOUDS SHUD START TO LIFT AND SCATTER OUT MID-LATE MORNING...SUCH THAT IT IS EXPECTED TO BE VFR BY NOON (16Z). AT THAT POINT...SWLY WINDS WILL INCREASE AND BECOME GUSTY THRU THE AFTN HOURS. STILL EXPECT AN AREA OF SCATTERED SHRA TO AFFECT THE REGION THIS EVENING AS A COLD FRONT PUSHES IN FROM THE NW. WILL HAVE A PROB30 FOR SHRA STARTING AT 00Z. INSTBY AND FORCING WILL BE LACKING FOR MUCH OF A TS CHC...SO WILL NOT HAVE MENTION WITH THESE TAFS. HOWEVER...IF GUIDANCE IS NOT HANDLING THE ENVIRONMENT WELL...THUNDER MAY BE ADDED IN WITH AN AMD OR THE 18Z TAF. SOME CLOUDS WILL PROBABLY LINGER BEHIND THE FRONT OVERNIGHT...WITH A SHIFT IN WINDS TO N/NE. GUIDANCE IS STILL MIXED ON WHETHER ANY RESTRICTIONS LOWER THAN VFR WILL OCCUR...SO STILL LEAVING IT VFR FOR TONIGHT. ELSEWHERE...IFR STRATUS HAS REACHED KGSP/KGMU AND WILL REACH KAND BY 12Z. THESE CLOUDS SHUD LIFT AND SCATTER OUT IN THE 14-16Z TIME FRAME TO VFR BY NOON. VFR CONDITIONS EXPECTED THIS AFTN WITH GUSTY S/SWLY WINDS AHEAD OF AN APPROACHING COLD FRONT. MOISTURE WITH THE FRONT IS PROGGED TO ENTER THE KAVL AREA BY MID AFTN AND ACRS THE REST OF THE TAF SITES LATE AFTN/EVENING. CONVECTION WITH THE FRONT LOOKS TO BE RATHER STARVED FOR FORCING/INSTBY...SO AM GOING WITH JUST PROB30S FOR SHRA AT ALL SITES. HIGHEST CHCS WILL BE AT KAVL...AS MOISTURE ENTERS THE MTNS FROM THE WEST...SO PREVAILING SHRA THERE WITH POTENTIAL RESTRICTIONS. LLVL MOISTURE/-RA MAY LINGER BEHIND THE FRONT LATE THIS EVENING...WHICH MAY RESULT IN SOME RESTRICTIONS. MODELS ARE STILL MIXED ON HOW MUCH CIG/VSBY RESTRICTIONS WILL EXIST...SO DECIDED TO KEEP IT VFR FOR NOW. OUTLOOK...IMPROVING CONDITIONS ARE EXPECTED BY MIDDAY THURSDAY AND VFR CONDITIONS EXPECTED THROUGH FRIDAY. THE NEXT SYSTEM WILL BRING MOISTURE BACK INTO THE AREA FRIDAY NIGHT THRU MOST OF THE WEEKEND. CONFIDENCE TABLE... 14-20Z 20-02Z 02-08Z 08-14Z KCLT HIGH 88% HIGH 100% HIGH 100% HIGH 80% KGSP HIGH 94% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 90% HIGH 89% MED 79% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 94% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 94% HIGH 92% HIGH 82% MED 72% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...MCAVOY NEAR TERM...ARK/LG SHORT TERM...MCAVOY LONG TERM...MCAVOY AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
743 AM EDT WED APR 24 2013 .SYNOPSIS... A COLD FRONT WILL SLOWLY CROSS THE WESTERN CAROLINAS AND NORTHEAST GEORGIA TONIGHT. MILD HIGH PRESSURE WILL THEN BUILD IN BEHIND THE FRONT FOR THURSDAY AND FRIDAY. A SLOW MOVING AREA OF LOW PRESSURE WILL DEVELOP OVER THE SOUTHERN PLAINS FRIDAY NIGHT AND DRIFT NORTHEASTWARD THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... 1130 UTC UPDATE...ONLY CHANGES WERE A FEW TWEAKS TO THE AVIATION GRIDS FOR THE 12Z TAFS. SKY GRIDS LOOK TO BE ROUGHLY IN LINE WITH CURRENT SAT/OBS. AS OF 515 AM...THE SKY GRIDS WERE UPDATED TO REFLECT ENCROACHING LOW STRATUS FROM THE SOUTH. THE 08Z RAP SEEMS TO BE INITIALIZING THE CLOUDS FAIRLY WELL AND SO IT WAS USED TO REFLECT TRENDS IN THE CLOUDS THRU MID MORNING. BASICALLY...IT LOOKS LIKE THE CLOUDS WILL REACH ROUGHLY TO I-85 AROUND OR SHORTLY AFTER DAYBREAK...EXTENDING NE TOWARD THE TRIAD. FROM THERE IT SHUD DISSIPATE AS INSOLATION MIXES THE INVERSION/SHALLOW MOISTURE OUT BY MIDDAY. MEANWHILE...STRATUS DECK (AROUND 5000 FT) CONTINUES TO WORK INTO THE SW NC MTNS AND NE GA FROM THE WEST. OVERALL...STILL EXPECTING SOME SUNSHINE BEFORE THICKER CLOUDS FINALLY OVERTAKE THE SKIES BY MID/LATE AFTN AS A COLD FRONT WORKS INTO THE AREA. NO OTHER CHANGES WERE MADE. AS OF 300 AM...A COLD FRONT WAS ANALYZED CROSSING OHIO VALLEY...WITH CONVECTION INCREASING IN COVERAGE ALONG AND AHEAD OF THE BNDRY. MODELS ARE IN GOOD AGREEMENT ON UPR LVL FORCING LAGGING BEHIND THE FRONT TODAY...WITH THE FRONT LOSING ITS PUNCH AS IT ENTERS THE NC MTNS THIS AFTN. FCST SNDGS ACRS THE PIEDMONT SHOW A SUBSIDENCE INVERSION THAT IS SLOW TO ERODE THIS AFTN/EVE...RESULTING IN GENERALLY LESS THAN 500 J/KG OF CAPE. TAKING A BLEND OF THE GFS AND NAM FOR CAPE...I ONLY GET CHC THUNDER IN THE MTNS WITH NO MENTION ACRS THE PIEDMONT. OVERALL...A MODEL BLEND OF THE POPS RESULTS IN A CUT BACK FROM PREV FCST. ALL IN ALL...EXPECTING MAINLY GARDEN VARIETY SHWRS/TSTMS IN THE MTNS THIS AFTN AND GENERALLY WIDELY SCT SHWRS ACRS THE ENTIRE AREA THIS EVENING...TAPERING OFF OVERNIGHT FROM NW TO SE. WITH THE FRONT HAVING AN ANAFRONT STRUCTURE...UPGLIDE BEHIND THE SFC BNDRY MAY RESULT IN LINGERING SHWRS ALONG AND SOUTH OF I-85 RIGHT UP TILL DAYBREAK. TEMPS SHUD BE ABLE TO WARM TO ABOVE NORMAL READINGS EAST OF THE MTNS...AS THICKER CLOUDS AND MOISTURE DOESN/T ENTER THE AREA TILL AFTER PEAK HEATING. LOWS OVERNIGHT NEAR NORMAL. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 235 AM EDT WEDNESDAY...THE LATEST NAM AND GFS RUNS CLEAR OUT CLOUD COVER BY ABOUT MID-MORNING ON THURSDAY. AS I DON/T THINK WE WILL SEE THAT MUCH PCPN INTO THE PRE-FRONTAL AIRMASS OVER THE FOOTHILLS AND PIEDMONT...I SUSPECT THAT LOW CLOUDS WON/T BE IN ABUNDANCE IN THE FIRST PLACE. IT WILL BE A NICE AFTERNOON WITH CLEAR...BLUE SKIES AND MAX TEMPS A COUPLE CATEGORIES BELOW NORMAL. FROST STILL APPEARS LIKE A GOOD BET OVER THE NC MTNS AND POSSIBLY THE WRN FOOTHILLS THURSDAY NIGHT. I/VE INCREASED THE AREAL COVERAGE OF FROST IN THE WEATHER GRIDS TO ACCOUNT FOR THIS. SOME OF THE TYPICAL COLD SPOTS AND/OR SHELTERED VALLEYS WILL WILL PROBABLY FALL TO FREEZING. FRIDAY WILL ALSO BE A NICE DAY...THOUGH MID AND HIGH LEVEL CLOUD COVER WILL INCREASE DURING THE AFTERNOON HOURS AHEAD OF A SOUTHERN STREAM SHORT WAVE. DESPITE THE HIGH CLOUDS...TEMPERATURES SHOULD BE A FEW DEGREES WARMER THAN THURSDAY/S HIGHS. FRIDAY NIGHT CLOUDS WILL CONTINUE TO THICKEN AND LOWER AND THERE WILL BE A CHANCE OF RAIN LATER AT NIGHT...ESPECIALLY OVER THE MOUNTAINS. THE PCPN WILL BE FORCED AS THE WRN CAROLINAS AND NE GA WILL BE IN THE RT ENTRANCE REGION OF A 110 KT UPPER JET CENTERED OVER ERN NC. A SRN STREAM JET MOVING ACROSS THE DEEP SOUTH MAY ALSO CONTRIBUTE SOME LIFT TO THE SYSTEM. THE SFC COLD FRONT WILL BE WELL TO OUR SOUTH...DOWN ALONG THE GULF COAST. THEREFORE THE PCPN SHOULD BE HIGH BASED AND MORE STRATIFORM IN NATURE. ANY STRONG LLVL WARM ADVECTION STAYS WELL SOUTHWEST OF THE REGION...CLOSER TO THE SFC-H8 FRONT...SO PCPN SHOULD BE LIGHT. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 300 AM EDT WEDNESDAY...THE LATEST WPC EXTENDED DISCUSSION FAVORS THE 12 UTC ECMWF FOR THE SAT-TUE PERIOD. LOOKING AT THEIR EXTENDED RANGE GUIDANCE...THEY HAVE LIKELY POPS ON SATURDAY AND SOLID CHANCE POPS SUN-TUE. WHILE THE LATEST GFS IS WEAKER WITH THE FORCING...IT/S STILL IN PRETTY GOOD AGREEMENT WITH THE 12 UTC RUN OF THE EC IN BRINGING A SRN STREAM SHORT WAVE SLOWLY ACROSS THE REGION OVER THE WEEKEND. UPGLIDE WILL INCREASE OVER A LLVL FRONTAL BNDRY...BRINGING PCPN TO THE REGION. HOWEVER...THERE HAS BEEN A TREND IN THE MODELS TO DEVELOP THE PCPN FARTHER SOUTH. THIS MAKES A LOT OF SENSE TO ME AS A BELT OF STRONG MID-TROPOSPHERE FLOW WILL EXIST DOWN TOWARD THE GOM. THE SFC BNDRY WILL LIKELY HAVE A DIFFICULT TIME LIFTING NORTH OF THIS BAROCLINIC ZONE ALOFT...AND I CAN SEE QUITE A BIT OF CONVECTION AND PCPN DEVELOPING DOWN TOWARD THE GULF...ESPECIALLY AS WE GET INTO SUNDAY. MONDAY AND TUESDAY THE SRN STREAM IS EVEN STRONGER AND FURTHER SOUTH AS A MID-LATITUDE H5 RIDGE BEGINS TO DEVELOP OVER THE TN RIVER VALLEY. THIS BLOCKING RIDGE PROVIDES A BROAD SEPARATION BETWEEN THE NRN STREAM SHOOTING ACROSS THE NRN PLAINS AND THE SRN STREAM DOWN ACROSS THE NRN GOM. WHILE WE WOULD CERTAINLY SEE SOME PCPN FROM THIS PATTERN...I SUSPECT THAT MOST OF THE PCPN INTO MON AND TUE WILL REMAIN SOUTH OF THE FORECAST AREA. THAT IS IF THIS PARTICULAR PATTERN DOES EVOLVE. THIS IS NOT A HIGH CONFIDENCE FORECAST...AND I/M NOT GOING TO DO ANYTHING DRAMATIC TO THE POPS ON THIS SHIFT. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... AT KCLT...IFR (AND EVEN A PERIOD OF LIFR) STRATUS AND FOG TO START THE 12Z TAF. THE CLOUDS SHUD START TO LIFT AND SCATTER OUT MID-LATE MORNING...SUCH THAT IT IS EXPECTED TO BE VFR BY NOON (16Z). AT THAT POINT...SWLY WINDS WILL INCREASE AND BECOME GUSTY THRU THE AFTN HOURS. STILL EXPECT AN AREA OF SCATTERED SHRA TO AFFECT THE REGION THIS EVENING AS A COLD FRONT PUSHES IN FROM THE NW. WILL HAVE A PROB30 FOR SHRA STARTING AT 00Z. INSTBY AND FORCING WILL BE LACKING FOR MUCH OF A TS CHC...SO WILL NOT HAVE MENTION WITH THESE TAFS. HOWEVER...IF GUIDANCE IS NOT HANDLING THE ENVIRONMENT WELL...THUNDER MAY BE ADDED IN WITH AN AMD OR THE 18Z TAF. SOME CLOUDS WILL PROBABLY LINGER BEHIND THE FRONT OVERNIGHT...WITH A SHIFT IN WINDS TO N/NE. GUIDANCE IS STILL MIXED ON WHETHER ANY RESTRICTIONS LOWER THAN VFR WILL OCCUR...SO STILL LEAVING IT VFR FOR TONIGHT. ELSEWHERE...IFR STRATUS HAS REACHED KGSP/KGMU AND WILL REACH KAND BY 12Z. THESE CLOUDS SHUD LIFT AND SCATTER OUT IN THE 14-16Z TIME FRAME TO VFR BY NOON. VFR CONDITIONS EXPECTED THIS AFTN WITH GUSTY S/SWLY WINDS AHEAD OF AN APPROACHING COLD FRONT. MOISTURE WITH THE FRONT IS PROGGED TO ENTER THE KAVL AREA BY MID AFTN AND ACRS THE REST OF THE TAF SITES LATE AFTN/EVENING. CONVECTION WITH THE FRONT LOOKS TO BE RATHER STARVED FOR FORCING/INSTBY...SO AM GOING WITH JUST PROB30S FOR SHRA AT ALL SITES. HIGHEST CHCS WILL BE AT KAVL...AS MOISTURE ENTERS THE MTNS FROM THE WEST...SO PREVAILING SHRA THERE WITH POTENTIAL RESTRICTIONS. LLVL MOISTURE/-RA MAY LINGER BEHIND THE FRONT LATE THIS EVENING...WHICH MAY RESULT IN SOME RESTRICTIONS. MODELS ARE STILL MIXED ON HOW MUCH CIG/VSBY RESTRICTIONS WILL EXIST...SO DECIDED TO KEEP IT VFR FOR NOW. OUTLOOK...IMPROVING CONDITIONS ARE EXPECTED BY MIDDAY THURSDAY AND VFR CONDITIONS EXPECTED THROUGH FRIDAY. THE NEXT SYSTEM WILL BRING MOISTURE BACK INTO THE AREA FRIDAY NIGHT THRU MOST OF THE WEEKEND. CONFIDENCE TABLE... 11-17Z 17-23Z 23-05Z 05-11Z KCLT MED 69% HIGH 100% HIGH 100% HIGH 86% KGSP MED 74% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 87% HIGH 85% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 82% HIGH 100% HIGH 100% HIGH 100% KAND MED 74% HIGH 100% HIGH 92% MED 66% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...MCAVOY NEAR TERM...ARK SHORT TERM...MCAVOY LONG TERM...MCAVOY AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
532 AM EDT WED APR 24 2013 .SYNOPSIS... A COLD FRONT WILL SLOWLY CROSS THE WESTERN CAROLINAS AND NORTHEAST GEORGIA TONIGHT. MILD HIGH PRESSURE WILL THEN BUILD IN BEHIND THE FRONT FOR THURSDAY AND FRIDAY. A SLOW MOVING AREA OF LOW PRESSURE WILL DEVELOP OVER THE SOUTHERN PLAINS FRIDAY NIGHT AND DRIFT NORTHEASTWARD THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 515 AM...THE SKY GRIDS WERE UPDATED TO REFLECT ENCROACHING LOW STRATUS FROM THE SOUTH. THE 08Z RAP SEEMS TO BE INITIALIZING THE CLOUDS FAIRLY WELL AND SO IT WAS USED TO REFLECT TRENDS IN THE CLOUDS THRU MID MORNING. BASICALLY...IT LOOKS LIKE THE CLOUDS WILL REACH ROUGHLY TO I-85 AROUND OR SHORTLY AFTER DAYBREAK...EXTENDING NE TOWARD THE TRIAD. FROM THERE IT SHUD DISSIPATE AS INSOLATION MIXES THE INVERSION/SHALLOW MOISTURE OUT BY MIDDAY. MEANWHILE...STRATUS DECK (AROUND 5000 FT) CONTINUES TO WORK INTO THE SW NC MTNS AND NE GA FROM THE WEST. OVERALL...STILL EXPECTING SOME SUNSHINE BEFORE THICKER CLOUDS FINALLY OVERTAKE THE SKIES BY MID/LATE AFTN AS A COLD FRONT WORKS INTO THE AREA. NO OTHER CHANGES WERE MADE. AS OF 300 AM...A COLD FRONT WAS ANALYZED CROSSING OHIO VALLEY...WITH CONVECTION INCREASING IN COVERAGE ALONG AND AHEAD OF THE BNDRY. MODELS ARE IN GOOD AGREEMENT ON UPR LVL FORCING LAGGING BEHIND THE FRONT TODAY...WITH THE FRONT LOSING ITS PUNCH AS IT ENTERS THE NC MTNS THIS AFTN. FCST SNDGS ACRS THE PIEDMONT SHOW A SUBSIDENCE INVERSION THAT IS SLOW TO ERODE THIS AFTN/EVE...RESULTING IN GENERALLY LESS THAN 500 J/KG OF CAPE. TAKING A BLEND OF THE GFS AND NAM FOR CAPE...I ONLY GET CHC THUNDER IN THE MTNS WITH NO MENTION ACRS THE PIEDMONT. OVERALL...A MODEL BLEND OF THE POPS RESULTS IN A CUT BACK FROM PREV FCST. ALL IN ALL...EXPECTING MAINLY GARDEN VARIETY SHWRS/TSTMS IN THE MTNS THIS AFTN AND GENERALLY WIDELY SCT SHWRS ACRS THE ENTIRE AREA THIS EVENING...TAPERING OFF OVERNIGHT FROM NW TO SE. WITH THE FRONT HAVING AN ANAFRONT STRUCTURE...UPGLIDE BEHIND THE SFC BNDRY MAY RESULT IN LINGERING SHWRS ALONG AND SOUTH OF I-85 RIGHT UP TILL DAYBREAK. TEMPS SHUD BE ABLE TO WARM TO ABOVE NORMAL READINGS EAST OF THE MTNS...AS THICKER CLOUDS AND MOISTURE DOESN/T ENTER THE AREA TILL AFTER PEAK HEATING. LOWS OVERNIGHT NEAR NORMAL. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 235 AM EDT WEDNESDAY...THE LATEST NAM AND GFS RUNS CLEAR OUT CLOUD COVER BY ABOUT MID-MORNING ON THURSDAY. AS I DON/T THINK WE WILL SEE THAT MUCH PCPN INTO THE PRE-FRONTAL AIRMASS OVER THE FOOTHILLS AND PIEDMONT...I SUSPECT THAT LOW CLOUDS WON/T BE IN ABUNDANCE IN THE FIRST PLACE. IT WILL BE A NICE AFTERNOON WITH CLEAR...BLUE SKIES AND MAX TEMPS A COUPLE CATEGORIES BELOW NORMAL. FROST STILL APPEARS LIKE A GOOD BET OVER THE NC MTNS AND POSSIBLY THE WRN FOOTHILLS THURSDAY NIGHT. I/VE INCREASED THE AREAL COVERAGE OF FROST IN THE WEATHER GRIDS TO ACCOUNT FOR THIS. SOME OF THE TYPICAL COLD SPOTS AND/OR SHELTERED VALLEYS WILL WILL PROBABLY FALL TO FREEZING. FRIDAY WILL ALSO BE A NICE DAY...THOUGH MID AND HIGH LEVEL CLOUD COVER WILL INCREASE DURING THE AFTERNOON HOURS AHEAD OF A SOUTHERN STREAM SHORT WAVE. DESPITE THE HIGH CLOUDS...TEMPERATURES SHOULD BE A FEW DEGREES WARMER THAN THURSDAY/S HIGHS. FRIDAY NIGHT CLOUDS WILL CONTINUE TO THICKEN AND LOWER AND THERE WILL BE A CHANCE OF RAIN LATER AT NIGHT...ESPECIALLY OVER THE MOUNTAINS. THE PCPN WILL BE FORCED AS THE WRN CAROLINAS AND NE GA WILL BE IN THE RT ENTRANCE REGION OF A 110 KT UPPER JET CENTERED OVER ERN NC. A SRN STREAM JET MOVING ACROSS THE DEEP SOUTH MAY ALSO CONTRIBUTE SOME LIFT TO THE SYSTEM. THE SFC COLD FRONT WILL BE WELL TO OUR SOUTH...DOWN ALONG THE GULF COAST. THEREFORE THE PCPN SHOULD BE HIGH BASED AND MORE STRATIFORM IN NATURE. ANY STRONG LLVL WARM ADVECTION STAYS WELL SOUTHWEST OF THE REGION...CLOSER TO THE SFC-H8 FRONT...SO PCPN SHOULD BE LIGHT. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 300 AM EDT WEDNESDAY...THE LATEST WPC EXTENDED DISCUSSION FAVORS THE 12 UTC ECMWF FOR THE SAT-TUE PERIOD. LOOKING AT THEIR EXTENDED RANGE GUIDANCE...THEY HAVE LIKELY POPS ON SATURDAY AND SOLID CHANCE POPS SUN-TUE. WHILE THE LATEST GFS IS WEAKER WITH THE FORCING...IT/S STILL IN PRETTY GOOD AGREEMENT WITH THE 12 UTC RUN OF THE EC IN BRINGING A SRN STREAM SHORT WAVE SLOWLY ACROSS THE REGION OVER THE WEEKEND. UPGLIDE WILL INCREASE OVER A LLVL FRONTAL BNDRY...BRINGING PCPN TO THE REGION. HOWEVER...THERE HAS BEEN A TREND IN THE MODELS TO DEVELOP THE PCPN FARTHER SOUTH. THIS MAKES A LOT OF SENSE TO ME AS A BELT OF STRONG MID-TROPOSPHERE FLOW WILL EXIST DOWN TOWARD THE GOM. THE SFC BNDRY WILL LIKELY HAVE A DIFFICULT TIME LIFTING NORTH OF THIS BAROCLINIC ZONE ALOFT...AND I CAN SEE QUITE A BIT OF CONVECTION AND PCPN DEVELOPING DOWN TOWARD THE GULF...ESPECIALLY AS WE GET INTO SUNDAY. MONDAY AND TUESDAY THE SRN STREAM IS EVEN STRONGER AND FURTHER SOUTH AS A MID-LATITUDE H5 RIDGE BEGINS TO DEVELOP OVER THE TN RIVER VALLEY. THIS BLOCKING RIDGE PROVIDES A BROAD SEPARATION BETWEEN THE NRN STREAM SHOOTING ACROSS THE NRN PLAINS AND THE SRN STREAM DOWN ACROSS THE NRN GOM. WHILE WE WOULD CERTAINLY SEE SOME PCPN FROM THIS PATTERN...I SUSPECT THAT MOST OF THE PCPN INTO MON AND TUE WILL REMAIN SOUTH OF THE FORECAST AREA. THAT IS IF THIS PARTICULAR PATTERN DOES EVOLVE. THIS IS NOT A HIGH CONFIDENCE FORECAST...AND I/M NOT GOING TO DO ANYTHING DRAMATIC TO THE POPS ON THIS SHIFT. && .AVIATION /10Z WEDNESDAY THROUGH SUNDAY/... AT KCLT...THE LATEST GUIDANCE IS STARTING TO CATCH ON TO SOME IFR STRATUS DEVELOPING ACRS CENTRAL/SOUTHERN SC DURING THE WEE MORNING HOURS...WITH A LIGHT SLY FLOW TAKING THE MOISTURE TOWARD KCLT. STILL NONE OF THE MODELS ACTUALLY HAVE RESTRICTIONS AT KCLT...SO HAVE NOT ADDED ANY MENTION WITH THE 06Z TAF. WITH THAT SAID...WILL MONITOR OBS/SAT CLOSELY...AS STRATUS MAY MAKE A RUN FOR THE TERMINAL AROUND DAYBREAK. OTHERWISE...VFR WITH A S/SWLY WIND. THE WIND WILL INCREASE AND BECOME SOMEWHAT GUSTY BY MIDDAY THRU THE AFTN. A COLD FRONT WILL PUSH INTO THE AREA THIS EVENING...BUT OVERALL MOISTURE WILL BE LIMITED SUCH THAT TS CHCS TOO LOW TO MENTION IN THE TAF. ELSEWHERE...ALL GUIDANCE KEEPING VFR CONDITIONS AT ALL TAF SITES THRU DAYBREAK. HOWEVER...IFR STRATUS IS DEVELOPING TO THE SOUTH AND MAY APPROACH THE UPSTATE SITES AROUND DAYBREAK. CONFIDENCE TOO LOW TO ADD MENTION TO THE 06Z TAFS...BUT THE TRENDS WILL BE MONITORED CLOSELY FOR POSSIBLE AMD. OTHERWISE...EXPECTING VFR CONDITION DURING THE DAY TODAY WITH INCREASING S/SWLY WINDS AHEAD OF AN APPROACHING COLD FRONT. MOISTURE WITH THE FRONT IS PROGGED TO ENTER THE KAVL AREA BY MID AFTN AND ACRS THE REST OF THE TAF SITES LATE AFTN/EVENING. CONVECTION WITH THE FRONT LOOKS TO BE RATHER STARVED FOR FORCING/INSTBY...SO CONTINUING WITH JUST PROB30S FOR TS AT ALL SITES. HIGHEST CHCS WILL BE AT KAVL...AS MOISTURE ENTERS THE MTNS FROM THE WEST. LLVL MOISTURE/-RA WILL LINGERING BEHIND THE FRONT LATE THIS EVENING...WHICH MAY RESULT IN SOME RESTRICTIONS. MODELS ARE MIXED ON HOW MUCH CIG/VSBY RESTRICTIONS WILL EXIST...SO DECIDED TO KEEP IT VFR FOR NOW. OUTLOOK...A COLD FRONT WILL CONTINUE TO PUSH THROUGH THE REGION DURING THE OVERNIGHT HOURS TONIGHT...AND MAY PRODUCE OCCASIONAL CIG AND VSBY RESTRICTIONS. IMPROVING CONDITIONS ARE EXPECTED ON THURSDAY AND VFR CONDITIONS EXPECTED THROUGH FRIDAY. THE NEXT SYSTEM WILL BRING MOISTURE BACK INTO THE AREA FRIDAY NIGHT THRU MOST OF THE WEEKEND. CONFIDENCE TABLE... 09-15Z 15-21Z 21-03Z 03-09Z KCLT HIGH 93% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 89% HIGH 83% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 99% HIGH 100% HIGH 92% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...MCAVOY NEAR TERM...ARK SHORT TERM...MCAVOY LONG TERM...MCAVOY AVIATION...ARK
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
952 PM CDT THU APR 25 2013 .UPDATE... A SURFACE TROUGH IS ALONG THE LOWER TEXAS COAST WITH A WARM FRONT DEVELOPING ALONG THE COAST. THE WARM FRONT WILL MOVE NORTH DURING THE OVERNIGHT HOURS AS THE LEFT ENTRANCE REGION OF AN UPPER LEVEL JET AND A WEAK MID LEVEL SHORT-WAVE MOVE ACROSS SOUTHERN TEXAS. UPWARD FORCING FROM THESE FEATURES WILL CAUSE PATCHY LIGHT RAIN OR DRIZZLE TO DEVELOP ACROSS SOUTH CENTRAL TEXAS DURING THE OVERNIGHT HOURS AS MENTIONED IN ONGOING FORECAST. TEMPERATURES RUNNING A DEGREE OR SO WARMER THAN FORECAST AND HAVE BOOSTED THEM SIMILARLY FOR THE REMAINDER OF TONIGHT INTO FRIDAY MORNING. SOME AREAS MAY SEE THEIR NIGHTTIME LOW IN THE NEXT FEW HOURS AND THEN RISE TOWARD MORNING AS DEWPOINTS CONTINUE TO INCREASE. REMAINDER OF SOUTH CENTRAL TEXAS FORECAST IS ON TRACK. CHANCES OF RAIN TREND HIGHER FOR THIS WEEKEND AS A SURFACE BOUNDARY AND SERIES OF WEAK UPPER LEVEL SHORT-WAVES INTERACT WITH INCREASING MOISTURE LEVELS TO ABOVE SEASONAL AVERAGES TO GENERATE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. THERE IS A POTENTIAL FOR STRONG TO MARGINALLY SEVERE STORMS TO DEVELOP ALONG THE FRONT OVER CENTRAL TEXAS AND OVER THE SERRANIAS DEL BURRO MOUNTAINS OF MEXICO AND THEN MOVE ACROSS SOUTH CENTRAL TEXAS ESPECIALLY SATURDAY AND SUNDAY NIGHTS. && .PREV DISCUSSION... /ISSUED 618 PM CDT THU APR 25 2013/ AVIATION... A SERIES OF UPPER SHORT-WAVE DISTURBANCES WILL COME ACROSS SOUTH CENTRAL TEXAS TONIGHT AND FRIDAY AS MAIN UPPER TROUGH CROSSES THE FOUR CORNERS REGION TONIGHT AND OVER THE TEXAS PANHANDLE FRIDAY MORNING. SOUTHEAST LOW LEVEL FLOW CONTINUES TO DOMINATE WITH DEWPOINTS IN THE UPPER 40S LATE THIS AFTERNOON...BUT INCREASING TO THE 50S AND 60S OVERNIGHT ACCORDING TO HIRES SOLUTIONS AND LATEST RUC13 GUIDANCE. THEREFORE...EXPECT CIGS TO LOWER TO MVFR AROUND 03Z TONIGHT AND LOWERING TO IFR AROUND OR AFTER 07Z...WITH POSSIBLE DRIZZLE/LIGHT RAIN ACROSS THE I-35 TERMINALS THROUGH 16Z FRIDAY. MVFR CONDITIONS WILL RETURN AND PREVAIL FOR THE REMAINDER OF THE FORECAST CYCLE. ACROSS KDRT...MVFR CIGS ARE EXPECTED AROUND 04Z TONIGHT AND PREVAIL TO ABOUT 17Z WITH VFR CONDITIONS RETURNING AFTERWARDS. SOUTHEASTERLY WINDS 4 TO 9 KNOTS ARE ANTICIPATED TONIGHT AND FRIDAY MORNING INCREASING 10 TO 15 KNOTS FRIDAY AFTERNOON. PREV DISCUSSION... /ISSUED 313 PM CDT THU APR 25 2013/ SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)... BOUNDARY LAYER WINDS HAVE BEGUN TO SHIFT TO THE EAST AND WILL CONTINUE TO VEER TO THE SOUTHEAST TONIGHT. THE ONSHORE FLOW WILL ADVECT GULF MOISTURE INTO THE REGION...KEEPING OVERCAST SKIES AND MILD TEMPERATURES TONIGHT. THE WARM AIR ADVECTION AND REMAINING SUBTLE ISENTROPIC LIFT SUGGEST THE POTENTIAL FOR ANOTHER ROUND OF EARLY MORNING LIGHT RAIN SHOWERS. SOME BREAKS IN THE CLOUD DECK ARE EXPECTED FRIDAY AFTERNOON WITH HIGHS REBOUNDING TO THE MID 70S TO LOW 80S. AN UPPER LEVEL LOW CURRENTLY MOVING ACROSS THE DESERT SOUTHWEST WILL EJECT TOWARD THE PLAINS STATES AS AN OPEN WAVE ON FRIDAY. THIS FEATURE WILL PROVIDE FOCUS FOR CONVECTION WELL NORTH OF OUR AREA...BUT COULD SEE ISOLATED SHOWERS/THUNDERSTORMS FRIDAY AFTERNOON ACROSS OUR NERN AREAS. FRIDAY NIGHT WILL BE MILD AND HUMID...BUT CHANCES FOR RAIN WILL BE WELL TO OUR NORTHEAST. LONG TERM (SATURDAY THROUGH THURSDAY)... A COLD FRONTAL BOUNDARY IN ASSOCIATION WITH THE SHORT-WAVE TROUGH WILL SKIRT ACROSS THE RED RIVER VALLEY FRIDAY NIGHT AND WILL STALL ACROSS CENTRAL TEXAS ON SATURDAY. THE FRONT IS NOT EXPECTED TO PUSH INTO OUR AREA...BUT WILL PROVIDE A FOCUS FOR ADDITIONAL CONVECTIVE ACTIVITY SATURDAY AND SATURDAY NIGHT. THERE IS ALSO THE POTENTIAL FOR ELEVATED CONVECTION TO DEVELOP ACROSS THE SERRANIAS DEL BURRO IN NERN MEXICO...AND A FEW STORMS MAY DRIFT ACROSS THE RIO GRANDE SATURDAY NIGHT/SUNDAY MORNING. WEAK ZONAL FLOW PREVAILING ALOFT AND THE LINGERING WASHED-OUT FRONTAL BOUNDARY WILL KEEP CHANCES FOR SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE REGION ON SUNDAY. BY SUNDAY NIGHT THE MOISTURE AXIS SHIFTS TO THE RIO GRANDE WITH ANOTHER ROUND OF BURRO MOUNTAIN STORMS POSSIBLE. THESE STORMS ARE KNOWN FOR THEIR POTENTIAL TO REACH SEVERE LEVELS AND/OR DEVELOP INTO MESO-SCALE CONVECTIVE SYSTEMS. OTHERWISE...THE SLOPPY PATTERN ALOFT WILL GENERALLY KEEP CONVECTIVE ACTIVITY SUB-SEVERE...BUT COULD SEE A FEW STORMS STRENGTHENED BY DIURNAL HEATING AND OUTFLOW BOUNDARIES AND POTENTIALLY BECOME STRONG. THE FRONT WILL RETREAT NORTHWARD ON MONDAY...BUT A WEAK UPPER DISTURBANCE WILL MOVE ACROSS THE REGION...KEEPING MENTIONABLE POPS IN THE FORECAST MONDAY AND TUESDAY. MODELS CONTINUE TO SUGGEST A MORE ORGANIZED PATTERN DEVELOPING ALOFT DURING THE MIDDLE OF THE WEEK WITH A COLD FRONT SOMETIME LATE WEDS/EARLY THURSDAY. TEMPERATURES WILL BE SEASONABLE AHEAD OF THE FRONT WITH HIGHS GENERALLY IN THE LOW 80S (MID-UPPER 80S OUT WEST) AND LOWS IN THE 60S. DESPITE THE DIFFERENCE IN TIMING OF THE FRONT FROM RUN-TO- RUN...MODELS HAVE BEEN CONSISTENT WITH THE STRENGTH OF THE FRONT. TEMPERATURES IN THE WAKE OF THE FRONT COULD POTENTIALLY BE 10 TO 15 DEGREES COOLER THAN WHAT WE`LL HAVE DURING THE MIDDLE OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 60 81 65 81 63 / 20 20 10 20 40 AUSTIN BERGSTROM INTL AIRPORT 57 80 64 80 61 / 20 20 10 20 40 NEW BRAUNFELS MUNI AIRPORT 60 82 65 80 64 / 20 20 10 20 40 BURNET MUNI AIRPORT 58 78 63 79 62 / 20 20 10 20 40 DEL RIO INTL AIRPORT 61 81 66 85 65 / 20 - - 20 40 GEORGETOWN MUNI AIRPORT 58 79 64 79 62 / 20 20 10 20 40 HONDO MUNI AIRPORT 59 82 65 81 64 / 20 10 10 20 40 SAN MARCOS MUNI AIRPORT 59 80 64 79 63 / 20 20 10 20 40 LA GRANGE - FAYETTE REGIONAL 62 82 66 80 65 / 20 20 10 20 20 SAN ANTONIO INTL AIRPORT 60 81 64 79 64 / 20 20 10 20 40 STINSON MUNI AIRPORT 60 81 65 80 65 / 20 20 10 20 40 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...17 SYNOPTIC/GRIDS...04 PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
618 PM CDT THU APR 25 2013 .AVIATION... A SERIES OF UPPER SHORT-WAVE DISTURBANCES WILL COME ACROSS SOUTH CENTRAL TEXAS TONIGHT AND FRIDAY AS MAIN UPPER TROUGH CROSSES THE FOUR CORNERS REGION TONIGHT AND OVER THE TEXAS PANHANDLE FRIDAY MORNING. SOUTHEAST LOW LEVEL FLOW CONTINUES TO DOMINATE WITH DEWPOINTS IN THE UPPER 40S LATE THIS AFTERNOON...BUT INCREASING TO THE 50S AND 60S OVERNIGHT ACCORDING TO HIRES SOLUTIONS AND LATEST RUC13 GUIDANCE. THEREFORE...EXPECT CIGS TO LOWER TO MVFR AROUND 03Z TONIGHT AND LOWERING TO IFR AROUND OR AFTER 07Z...WITH POSSIBLE DRIZZLE/LIGHT RAIN ACROSS THE I-35 TERMINALS THROUGH 16Z FRIDAY. MVFR CONDITIONS WILL RETURN AND PREVAIL FOR THE REMAINDER OF THE FORECAST CYCLE. ACROSS KDRT...MVFR CIGS ARE EXPECTED AROUND 04Z TONIGHT AND PREVAIL TO ABOUT 17Z WITH VFR CONDITIONS RETURNING AFTERWARDS. SOUTHEASTERLY WINDS 4 TO 9 KNOTS ARE ANTICIPATED TONIGHT AND FRIDAY MORNING INCREASING 10 TO 15 KNOTS FRIDAY AFTERNOON. && .PREV DISCUSSION... /ISSUED 313 PM CDT THU APR 25 2013/ SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)... BOUNDARY LAYER WINDS HAVE BEGUN TO SHIFT TO THE EAST AND WILL CONTINUE TO VEER TO THE SOUTHEAST TONIGHT. THE ONSHORE FLOW WILL ADVECT GULF MOISTURE INTO THE REGION...KEEPING OVERCAST SKIES AND MILD TEMPERATURES TONIGHT. THE WARM AIR ADVECTION AND REMAINING SUBTLE ISENTROPIC LIFT SUGGEST THE POTENTIAL FOR ANOTHER ROUND OF EARLY MORNING LIGHT RAIN SHOWERS. SOME BREAKS IN THE CLOUD DECK ARE EXPECTED FRIDAY AFTERNOON WITH HIGHS REBOUNDING TO THE MID 70S TO LOW 80S. AN UPPER LEVEL LOW CURRENTLY MOVING ACROSS THE DESERT SOUTHWEST WILL EJECT TOWARD THE PLAINS STATES AS AN OPEN WAVE ON FRIDAY. THIS FEATURE WILL PROVIDE FOCUS FOR CONVECTION WELL NORTH OF OUR AREA...BUT COULD SEE ISOLATED SHOWERS/THUNDERSTORMS FRIDAY AFTERNOON ACROSS OUR NERN AREAS. FRIDAY NIGHT WILL BE MILD AND HUMID...BUT CHANCES FOR RAIN WILL BE WELL TO OUR NORTHEAST. LONG TERM (SATURDAY THROUGH THURSDAY)... A COLD FRONTAL BOUNDARY IN ASSOCIATION WITH THE SHORT-WAVE TROUGH WILL SKIRT ACROSS THE RED RIVER VALLEY FRIDAY NIGHT AND WILL STALL ACROSS CENTRAL TEXAS ON SATURDAY. THE FRONT IS NOT EXPECTED TO PUSH INTO OUR AREA...BUT WILL PROVIDE A FOCUS FOR ADDITIONAL CONVECTIVE ACTIVITY SATURDAY AND SATURDAY NIGHT. THERE IS ALSO THE POTENTIAL FOR ELEVATED CONVECTION TO DEVELOP ACROSS THE SERRANIAS DEL BURRO IN NERN MEXICO...AND A FEW STORMS MAY DRIFT ACROSS THE RIO GRANDE SATURDAY NIGHT/SUNDAY MORNING. WEAK ZONAL FLOW PREVAILING ALOFT AND THE LINGERING WASHED-OUT FRONTAL BOUNDARY WILL KEEP CHANCES FOR SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE REGION ON SUNDAY. BY SUNDAY NIGHT THE MOISTURE AXIS SHIFTS TO THE RIO GRANDE WITH ANOTHER ROUND OF BURRO MOUNTAIN STORMS POSSIBLE. THESE STORMS ARE KNOWN FOR THEIR POTENTIAL TO REACH SEVERE LEVELS AND/OR DEVELOP INTO MESO-SCALE CONVECTIVE SYSTEMS. OTHERWISE...THE SLOPPY PATTERN ALOFT WILL GENERALLY KEEP CONVECTIVE ACTIVITY SUB-SEVERE...BUT COULD SEE A FEW STORMS STRENGTHENED BY DIURNAL HEATING AND OUTFLOW BOUNDARIES AND POTENTIALLY BECOME STRONG. THE FRONT WILL RETREAT NORTHWARD ON MONDAY...BUT A WEAK UPPER DISTURBANCE WILL MOVE ACROSS THE REGION...KEEPING MENTIONABLE POPS IN THE FORECAST MONDAY AND TUESDAY. MODELS CONTINUE TO SUGGEST A MORE ORGANIZED PATTERN DEVELOPING ALOFT DURING THE MIDDLE OF THE WEEK WITH A COLD FRONT SOMETIME LATE WEDS/EARLY THURSDAY. TEMPERATURES WILL BE SEASONABLE AHEAD OF THE FRONT WITH HIGHS GENERALLY IN THE LOW 80S (MID-UPPER 80S OUT WEST) AND LOWS IN THE 60S. DESPITE THE DIFFERENCE IN TIMING OF THE FRONT FROM RUN-TO- RUN...MODELS HAVE BEEN CONSISTENT WITH THE STRENGTH OF THE FRONT. TEMPERATURES IN THE WAKE OF THE FRONT COULD POTENTIALLY BE 10 TO 15 DEGREES COOLER THAN WHAT WE`LL HAVE DURING THE MIDDLE OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 59 81 65 81 63 / 20 20 10 20 40 AUSTIN BERGSTROM INTL AIRPORT 56 80 64 80 61 / 20 20 10 20 40 NEW BRAUNFELS MUNI AIRPORT 59 82 65 80 64 / 20 20 10 20 40 BURNET MUNI AIRPORT 57 78 63 79 62 / 20 20 10 20 40 DEL RIO INTL AIRPORT 60 81 66 85 65 / 20 - - 20 40 GEORGETOWN MUNI AIRPORT 57 79 64 79 62 / 20 20 10 20 40 HONDO MUNI AIRPORT 58 82 65 81 64 / 20 10 10 20 40 SAN MARCOS MUNI AIRPORT 58 80 64 79 63 / 20 20 10 20 40 LA GRANGE - FAYETTE REGIONAL 61 82 66 80 65 / 20 20 10 20 20 SAN ANTONIO INTL AIRPORT 59 81 64 79 64 / 20 20 10 20 40 STINSON MUNI AIRPORT 59 81 65 80 65 / 20 20 10 20 40 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...17 SYNOPTIC/GRIDS...04 PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1023 AM EDT WED APR 24 2013 .SYNOPSIS... LOW PRESSURE WAS OVER THE GREAT LAKES WITH A COLD FRONT EXTENDING INTO SOUTHERN TEXAS. THIS FRONT WILL CROSS THE REGION TODAY WITH HIGH PRESSURE FOLLOWING FOR THURSDAY AND FRIDAY. LOW PRESSURE WILL MOVE FROM THE SOUTHERN PLAINS ACROSS THE TENNESSEE VALLEY AND CAROLINAS ON SATURDAY AND SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 940 AM EDT WEDNESDAY... PATCHY EARLY MORNING FOG HAS QUICKLY LIFTED AS MODEST SURFACE WINDS RESULTED IN SUFFICIENT MIXING. CLEAR SKIES THIS MORNING AND EARLY AFTERNOON WILL ALLOW TEMPERATURES TO WARM UP QUICKLY BEFORE CLOUDS ROLL INTO THE AREA AS THE FRONTAL PASSAGE APPROACHES. CLOUD COVER BEGINS TO INCREASE SUBTLY UNTIL NOON...THEN SHIFT TO MOSTLY OVERCAST BY THE MID AFTERNOON. THE FRONT WILL MOVE THROUGH THE CWA BETWEEN 6PM AND MIDNIGHT. GFS AND WRF AGREE ON THE TIMING OF THE FRONT. PRECIPITATION ASSOCIATED WITH THE FRONT VARY ACROSS THE CWA... RANGING FROM A QUARTER OF AN INCH TO THE WEST AND GENERALLY LIGHTER QPF IN THE EAST AROUND OR LESS THAN A TENTH OF AN INCH. THE SPC HAS THE CWA UNDER A SEE TEXT... STRONG CONVECTION IS POSSIBLE WITH THIS SYSTEM... WITH DAMAGING WIND BEING THE MAIN THREAT. CAPE WILL BE FAIRLY LIMITED WITH VALUES BELOW 500 J/KG AS DAYTIME HEATING WILL BE CUT SHORT BY THE IMPEDING CLOUD COVER... HOWEVER SOME STRONGER POCKETS OF ENERGY IN THE WESTERN MOST COUNTIES COULD SPRING UP SOME THUNDERSTORMS. THE FRONT WILL START TO BREAK DOWN AS IT CROSSES THE MOUNTAINS LEADING TO MORE LOCALIZED PRECIPITATION AFTER IT PASSES. COLD AIR WILL INFILTRATE IN THE WAKE AND KNOCK TEMPERATURES UNSEASONABLY COOL AS HIGH PRESSURE BEGINS TO MOVE IN FROM THE TENNESSEE VALLEY. MID-MORNING TEMPERATURES WERE ADJUSTED WARMER BY 5-7 DEGREES IN PREDOMINATELY WESTERN LOCATIONS. CLOUD COVER WAS DECREASED IN THE EARLY MORNING/AFTERNOON AND RAPIDLY INCREASES AHEAD OF THE FRONT. MORNING GRID UPDATES ARE COMPLETED. AS OF 430 AM EDT WEDNESDAY... STARTING OUT WITH LITTLE CLOUD COVER THIS MORNING. ONCE MIXING BEGINS WINDS WILL GUST OUT OF THE SOUTHWEST AND TEMPERATURES WILL WARM UP QUICKLY. BY THIS AFTERNOON CLOUD COVER MOVES IN SLOWING DOWN HEATING FOR THE REST OF THE DAY. SHORT RANGE MODELS...INCLUDING THE RUC AND WRF...HAVE SLOWED DOWN THE TIME OF THE FRONTAL PASSAGE BY A COUPLE OF HOURS. FORECAST HAS THE FRONT MOVING THROUGH THE COUNTY WARNING AREA BETWEEN 6PM AND MIDNIGHT. SHOWERS AND THUNDERSTORMS MAY COME THROUGH IN TWO BANDS. ONE ALONG THE FRONT...SIMILAR TO WHAT WAS DEVELOPING AROUND 5AM FROM KENTUCKY TO LOUISIANA...AND THE SECOND...BEHIND THE FRONT. CONVECTIVE AVAILABLE POTENTIAL ENERGY HAS THE POTENTIAL TO REACH AROUND 1500 J/KG THIS AFTERNOON BUT MODELS DROP OFF INSTABILITY QUICKLY AFTER SUNSET. QUESTIONABLE IF ANY OF THE PRECIPITATION BEHIND THE FRONT WILL HOLD TOGETHER EAST OF THE BLUE RIDGE. ONCE THE WIND SHIFT TO THE NORTHWEST...TENDENCY IS FOR DOWNSLOPING COMPONENT TO ERODE PRECIPITATION. HAVE KEPT PROBABILITY OF PRECIPITATION HIGHEST IN THE FAR WESTERN COUNTY WARNING AREA AND MUCH LOWER IN THE EAST. GOOD PRESSURE RISES AND COLD AIR ADVECTION BEHIND THE FRONT TONIGHT WILL RESULT IN GUSTY NORTHWEST WINDS. THE COOLER AIR MASS COMING IN WILL HOLD LOW TEMPERATURES BELOW NORMAL. && .SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/... AS OF 327 AM EDT WEDNESDAY... HIGH PRESSURE STRENGTHENS AND STRETCHES INTO THE MIDDLE ATLANTIC THURSDAY AND THURSDAY NIGHT. ONE FINAL SHRTWV WITH SCANT MOISTURE CUTTING THROUGH WEST VA WILL THROW SOME CLOUDS BRIEFLY INTO SE WEST VA LATE THURSDAY AFTERNOON BEFORE DEPARTING THURSDAY NIGHT. FRIDAY MORNING LOOKS LIKE A CHILLY ONE WITH SOME MINS NEAR FREEZING AT THE COLDEST SPOTS AND POTENTIALLY NEAR THE MIDDLE 30S ACROSS THE VIRGINIA PIEDMONT WHICH MAY LEAD TO SOME PATCHY FROST. AS THE HIGH DEPARTS LATER FRIDAY SOME HIGH CLOUDS ARRIVE BEFORE MOISTURE INCREASES AND WINDS BEGIN TO TAKE ON AN EASTERLY COMPONENT INTO THE WEEKEND. PINPOINTING POPS FOR THIS WEEKEND REALLY TOUGH RIGHT NOW WITH MODELS NOT SHOWING A LOT OF MEASURABLE PRECIP SAVE THE NC/VA BORDER. BUT...WOULD THINK SE TO ESE FLOW AND ABUNDANT MOISTURE WOULD BE ENOUGH FOR SOME LIGHT RAIN SATURDAY OR SATURDAY NIGHT...FURTHER NORTH THAN MOST MODELS DEPICT. THE 0Z ECMWF CONTINUES TO BE THE WETTEST SOLUTION BUT EVEN IT HAS NOW SHIFTED THE PRECIP FURTHER SOUTH. NONETHELESS...GUIDANCE FOR MAX T SATURDAY SEEMED SEVERAL DEGREES TOO WARM CONSIDERING ALL OF THE ABOVE...SO WENT BELOW THE MEX MOS NUMBERS...SUBSTANTIALLY SO IN THE TYPICAL WEDGE AREAS. && .LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 355 PM EDT THURSDAY... CONSIDERABLE DIFFERENCES REMAIN AMONG THE GFS AND ECMWF DURING THE EXTENDED PERIODS...BUT ANY WAY YOU LOOK AT IT...IT IS GOING TO BE WET AND UNSEASONABLY COOL. A VIGOROUS SOUTHERN STREAM DISTURBANCE IS STILL SLATED TO MOVE INTO THE REGION FROM THE WEST. IT IS THE SUBSEQUENT MOVEMENT/DEVELOPMENT OF THIS SYSTEM THROUGH THE WEEKEND INTO EARLY NEXT WEEK THAT BECOMES THE QUESTION. THE GFS HAS IN GENERAL SHOWN MORE CONSISTENCY WITH THE EVOLUTION OF THIS SYSTEM THAN THE ECMWF. EACH RUN OF THE ECMWF DEVELOPS A CUTOFF IN A DIFFERENT LOCATION...WHICH IS RESULTING IN LOWERING CONFIDENCE IN ANY ONE SOLUTION FROM THAT MODEL. HOWEVER...BOTH THE GFS AND ECMWF GIVE SOME HINT OF AT LEAST WEAK CUTOFF LOW PRESSURE DEVELOPING ACROSS THE SOUTHEAST STATES IN A WEAKNESS AREA. THEREFORE...HAVE KEPT LIKELY POPS SAT-SUN...THEN TAPER TO MOSTLY CHANCE POPS DURING THE LATER PERIODS. THE LATEST ECMWF HAS DEFINITELY TRENDED TOWARD A DRIER/WEAKER SOLUTION. INSTABILITY IS NIL THROUGH THE PERIOD AND WITH BOTH MODELS THERE IS A STRONG SIGNAL FOR A WEDGE REINFORCED...HENCE IN SITU AS WELL. HAVE FAVORED THE MUCH COOLER ECMWF GRIDS THROUGHOUT THE EXTENDED PERIODS. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... AS OF 145 AM EDT WEDNESDAY... ONCE MIXING BEGINS THIS MORNING THE WIND WILL INCREASE FROM THE SOUTHWEST AHEAD OF THE APPROACHING COLD FRONT. BUFKIT INDICATED JET WOULD BE IN THE 25 TO 35 KNOT RANGE. CLOUDS WILL INCREASE THROUGHOUT THE DAY...ALTHOUGH CEILINGS WILL REMAIN VFR. LOW PRESSURE MOVING ACROSS THE GREAT LAKES WILL BRING A COLD FRONT THROUGH THE REGION THIS EVENING. EXPECT FRONTAL PASSAGE AND WIND SHIFT TO THE NORTHWEST AROUND 23Z/7PM AT BLF AND LWB AND BETWEEN 00Z/8PM AND 03Z/11PM AT BCB/ROA/DAN/LYH. BRIEF WIND GUSTS TO 35 KNOTS ARE POSSIBLE WITH THE STRONGER SHOWERS AND THUNDERSTORMS ALONG THE FRONT. THE SHOWERS MAY NEVER REACH DAN AND LYH WITH NORTHWEST DOWNSLOPE WINDS AND THE PRECIPITATION MAINLY BEHIND THE BOUNDARY. WINDS WILL STILL GUST 20 TO 25 KNOTS FOR A FEW HOURS BEHIND THE FRONT DUE TO PRESSURE RISES AND COLD AIR ADVECTION. CEILINGS MAY DROP TO MVFR AT BLF AND LWB BEHIND THE FRONT.CONFIDENCE IS MODERATE THAT CEILINGS WILL STILL BE MVFR BY 12Z THURSDAY. HIGH PRESSURE WILL BUILD IN QUICKLY IN THE WAKE OF THE COLD FRONT FOR THURSDAY AND FRIDAY. ANY MVFR CEILINGS WILL BE WEST OF THE BLUE RIDGE...AND WILL IMPROVE TO VFR THURSDAY MORNING. THIS WEEKEND WILL BE UNSETTLED WITH PERIODS OF SHOWERS BEGINNING SATURDAY AFTERNOON. EXPECT PERIODS OF IFR/MVFR CONDITIONS SATURDAY AFTERNOON THROUGH THE REST OF THE WEEKEND. && .FIRE WEATHER... AS OF 515 AM EDT WEDNESDAY... BREEZY SOUTHWEST WINDS AHEAD OF AN APPROACHING COLD FRONT TODAY. SOUTHWEST WINDS OF 10 TO 15 MPH WITH GUSTS OF 20 TO 30 MPH ARE LIKELY BY THIS AFTERNOON. THE WIND WILL ABRUPTLY SHIFT TO THE NORTHWEST WITH THE PASSAGE OF THE FRONT THIS EVENING. THE FRONT IS EXPECTED TO CROSS THE MOUNTAINS BETWEEN 6-9PM...THEN MOVE EAST OF THE BLUE RIDGE AND ACROSS THE PIEDMONT BEFORE MIDNIGHT. THE CHANCE OF RAIN MOVES BACK INTO THE FORECAST AREA AGAIN ON SATURDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/KK/SW SHORT TERM...KM LONG TERM...RAB AVIATION...AMS FIRE WEATHER...AMS/PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
742 AM EDT WED APR 24 2013 .SYNOPSIS... LOW PRESSURE WAS OVER THE GREAT LAKES WITH A COLD FRONT EXTENDING INTO SOUTHERN TEXAS. THIS FRONT WILL CROSS THE REGION TODAY WITH HIGH PRESSURE FOLLOWING FOR THURSDAY AND FRIDAY. LOW PRESSURE WILL MOVE FROM THE SOUTHERN PLAINS ACROSS THE TENNESSEE VALLEY AND CAROLINAS ON SATURDAY AND SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 430 AM EDT WEDNESDAY... STARTING OUT WITH LITTLE CLOUD COVER THIS MORNING. ONCE MIXING BEGINS WINDS WILL GUST OUT OF THE SOUTHWEST AND TEMPERATURES WILL WARM UP QUICKLY. BY THIS AFTERNOON CLOUD COVER MOVES IN SLOWING DOWN HEATING FOR THE REST OF THE DAY. SHORT RANGE MODELS...INCLUDING THE RUC AND WRF...HAVE SLOWED DOWN THE TIME OF THE FRONTAL PASSAGE BY A COUPLE OF HOURS. FORECAST HAS THE FRONT MOVING THROUGH THE COUNTY WARNING AREA BETWEEN 6PM AND MIDNIGHT. SHOWERS AND THUNDERSTORMS MAY COME THROUGH IN TWO BANDS. ONE ALONG THE FRONT...SIMILAR TO WHAT WAS DEVELOPING AROUND 5AM FROM KENTUCKY TO LOUISIANA...AND THE SECOND...BEHIND THE FRONT. CONVECTIVE AVAILABLE POTENTIAL ENERGY HAS THE POTENTIAL TO REACH AROUND 1500 J/KG THIS AFTERNOON BUT MODELS DROP OFF INSTABILITY QUICKLY AFTER SUNSET. QUESTIONABLE IF ANY OF THE PRECIPITATION BEHIND THE FRONT WILL HOLD TOGETHER EAST OF THE BLUE RIDGE. ONCE THE WIND SHIFT TO THE NORTHWEST...TENDENCY IS FOR DOWNSLOPING COMPONENT TO ERODE PRECIPITATION. HAVE KEPT PROBABILITY OF PRECIPITATION HIGHEST IN THE FAR WESTERN COUNTY WARNING AREA AND MUCH LOWER IN THE EAST. GOOD PRESSURE RISES AND COLD AIR ADVECTION BEHIND THE FRONT TONIGHT WILL RESULT IN GUSTY NORTHWEST WINDS. THE COOLER AIR MASS COMING IN WILL HOLD LOW TEMPERATURES BELOW NORMAL. && .SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/... AS OF 327 AM EDT WEDNESDAY... HIGH PRESSURE STRENGTHENS AND STRETCHES INTO THE MIDDLE ATLANTIC THURSDAY AND THURSDAY NIGHT. ONE FINAL SHRTWV WITH SCANT MOISTURE CUTTING THROUGH WEST VA WILL THROW SOME CLOUDS BRIEFLY INTO SE WEST VA LATE THURSDAY AFTERNOON BEFORE DEPARTING THURSDAY NIGHT. FRIDAY MORNING LOOKS LIKE A CHILLY ONE WITH SOME MINS NEAR FREEZING AT THE COLDEST SPOTS AND POTENTIALLY NEAR THE MIDDLE 30S ACROSS THE VIRGINIA PIEDMONT WHICH MAY LEAD TO SOME PATCHY FROST. AS THE HIGH DEPARTS LATER FRIDAY SOME HIGH CLOUDS ARRIVE BEFORE MOISTURE INCREASES AND WINDS BEGIN TO TAKE ON AN EASTERLY COMPONENT INTO THE WEEKEND. PINPOINTING POPS FOR THIS WEEKEND REALLY TOUGH RIGHT NOW WITH MODELS NOT SHOWING A LOT OF MEASURABLE PRECIP SAVE THE NC/VA BORDER. BUT...WOULD THINK SE TO ESE FLOW AND ABUNDANT MOISTURE WOULD BE ENOUGH FOR SOME LIGHT RAIN SATURDAY OR SATURDAY NIGHT...FURTHER NORTH THAN MOST MODELS DEPICT. THE 0Z ECMWF CONTINUES TO BE THE WETTEST SOLUTION BUT EVEN IT HAS NOW SHIFTED THE PRECIP FURTHER SOUTH. NONETHELESS...GUIDANCE FOR MAX T SATURDAY SEEMED SEVERAL DEGREES TOO WARM CONSIDERING ALL OF THE ABOVE...SO WENT BELOW THE MEX MOS NUMBERS...SUBSTANTIALLY SO IN THE TYPICAL WEDGE AREAS. && .LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 355 PM EDT THURSDAY... CONSIDERABLE DIFFERENCES REMAIN AMONG THE GFS AND ECMWF DURING THE EXTENDED PERIODS...BUT ANY WAY YOU LOOK AT IT...IT IS GOING TO BE WET AND UNSEASONABLY COOL. A VIGOROUS SOUTHERN STREAM DISTURBANCE IS STILL SLATED TO MOVE INTO THE REGION FROM THE WEST. IT IS THE SUBSEQUENT MOVEMENT/DEVELOPMENT OF THIS SYSTEM THROUGH THE WEEKEND INTO EARLY NEXT WEEK THAT BECOMES THE QUESTION. THE GFS HAS IN GENERAL SHOWN MORE CONSISTENCY WITH THE EVOLUTION OF THIS SYSTEM THAN THE ECMWF. EACH RUN OF THE ECMWF DEVELOPS A CUTOFF IN A DIFFERENT LOCATION...WHICH IS RESULTING IN LOWERING CONFIDENCE IN ANY ONE SOLUTION FROM THAT MODEL. HOWEVER...BOTH THE GFS AND ECMWF GIVE SOME HINT OF AT LEAST WEAK CUTOFF LOW PRESSURE DEVELOPING ACROSS THE SOUTHEAST STATES IN A WEAKNESS AREA. THEREFORE...HAVE KEPT LIKELY POPS SAT-SUN...THEN TAPER TO MOSTLY CHANCE POPS DURING THE LATER PERIODS. THE LATEST ECMWF HAS DEFINITELY TRENDED TOWARD A DRIER/WEAKER SOLUTION. INSTABILITY IS NIL THROUGH THE PERIOD AND WITH BOTH MODELS THERE IS A STRONG SIGNAL FOR A WEDGE REINFORCED...HENCE IN SITU AS WELL. HAVE FAVORED THE MUCH COOLER ECMWF GRIDS THROUGHOUT THE EXTENDED PERIODS. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... AS OF 145 AM EDT WEDNESDAY... ONCE MIXING BEGINS THIS MORNING THE WIND WILL INCREASE FROM THE SOUTHWEST AHEAD OF THE APPROACHING COLD FRONT. BUFKIT INDICATED JET WOULD BE IN THE 25 TO 35 KNOT RANGE. CLOUDS WILL INCREASE THROUGHOUT THE DAY...ALTHOUGH CEILINGS WILL REMAIN VFR. LOW PRESSURE MOVING ACROSS THE GREAT LAKES WILL BRING A COLD FRONT THROUGH THE REGION THIS EVENING. EXPECT FRONTAL PASSAGE AND WIND SHIFT TO THE NORTHWEST AROUND 23Z/7PM AT BLF AND LWB AND BETWEEN 00Z/8PM AND 03Z/11PM AT BCB/ROA/DAN/LYH. BRIEF WIND GUSTS TO 35 KNOTS ARE POSSIBLE WITH THE STRONGER SHOWERS AND THUNDERSTORMS ALONG THE FRONT. THE SHOWERS MAY NEVER REACH DAN AND LYH WITH NORTHWEST DOWNSLOPE WINDS AND THE PRECIPITATION MAINLY BEHIND THE BOUNDARY. WINDS WILL STILL GUST 20 TO 25 KNOTS FOR A FEW HOURS BEHIND THE FRONT DUE TO PRESSURE RISES AND COLD AIR ADVECTION. CEILINGS MAY DROP TO MVFR AT BLF AND LWB BEHIND THE FRONT.CONFIDENCE IS MODERATE THAT CEILINGS WILL STILL BE MVFR BY 12Z THURSDAY. HIGH PRESSURE WILL BUILD IN QUICKLY IN THE WAKE OF THE COLD FRONT FOR THURSDAY AND FRIDAY. ANY MVFR CEILINGS WILL BE WEST OF THE BLUE RIDGE...AND WILL IMPROVE TO VFR THURSDAY MORNING. THIS WEEKEND WILL BE UNSETTLED WITH PERIODS OF SHOWERS BEGINNING SATURDAY AFTERNOON. EXPECT PERIODS OF IFR/MVFR CONDITIONS SATURDAY AFTERNOON THROUGH THE REST OF THE WEEKEND. && .FIRE WEATHER... AS OF 515 AM EDT WEDNESDAY... BREEZY SOUTHWEST WINDS AHEAD OF AN APPROACHING COLD FRONT TODAY. SOUTHWEST WINDS OF 10 TO 15 MPH WITH GUSTS OF 20 TO 30 MPH ARE LIKELY BY THIS AFTERNOON. THE WIND WILL ABRUPTLY SHIFT TO THE NORTHWEST WITH THE PASSAGE OF THE FRONT THIS EVENING. THE FRONT IS EXPECTED TO CROSS THE MOUNTAINS BETWEEN 6-9PM...THEN MOVE EAST OF THE BLUE RIDGE AND ACROSS THE PIEDMONT BEFORE MIDNIGHT. THE CHANCE OF RAIN MOVES BACK INTO THE FORECAST AREA AGAIN ON SATURDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/PM/WP SHORT TERM...KM LONG TERM...RAB AVIATION...AMS FIRE WEATHER...AMS/PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
517 AM EDT WED APR 24 2013 .SYNOPSIS... LOW PRESSURE WAS OVER THE GREAT LAKES WITH A COLD FRONT EXTENDING INTO SOUTHERN TEXAS. THIS FRONT WILL CROSS THE REGION TODAY WITH HIGH PRESSURE FOLLOWING FOR THURSDAY AND FRIDAY. LOW PRESSURE WILL MOVE FROM THE SOUTHERN PLAINS ACROSS THE TENNESSEE VALLEY AND CAROLINAS ON SATURDAY AND SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 430 AM EDT WEDNESDAY... STARTING OUT WITH LITTLE CLOUD COVER THIS MORNING. ONCE MIXING BEGINS WINDS WILL GUST OUT OF THE SOUTHWEST AND TEMPERATURES WILL WARM UP QUICKLY. BY THIS AFTERNOON CLOUD COVER MOVES IN SLOWING DOWN HEATING FOR THE REST OF THE DAY. SHORT RANGE MODELS...INCLUDING THE RUC AND WRF...HAVE SLOWED DOWN THE TIME OF THE FRONTAL PASSAGE BY A COUPLE OF HOURS. FORECAST HAS THE FRONT MOVING THROUGH THE COUNTY WARNING AREA BETWEEN 6PM AND MIDNIGHT. SHOWERS AND THUNDERSTORMS MAY COME THROUGH IN TWO BANDS. ONE ALONG THE FRONT...SIMILAR TO WHAT WAS DEVELOPING AROUND 5AM FROM KENTUCKY TO LOUISIANA...AND THE SECOND...BEHIND THE FRONT. CONVECTIVE AVAILABLE POTENTIAL ENERGY HAS THE POTENTIAL TO REACH AROUND 1500 J/KG THIS AFTERNOON BUT MODELS DROP OFF INSTABILITY QUICKLY AFTER SUNSET. QUESTIONABLE IF ANY OF THE PRECIPITATION BEHIND THE FRONT WILL HOLD TOGETHER EAST OF THE BLUE RIDGE. ONCE THE WIND SHIFT TO THE NORTHWEST...TENDENCY IS FOR DOWNSLOPING COMPONENT TO ERODE PRECIPITATION. HAVE KEPT PROBABILITY OF PRECIPITATION HIGHEST IN THE FAR WESTERN COUNTY WARNING AREA AND MUCH LOWER IN THE EAST. GOOD PRESSURE RISES AND COLD AIR ADVECTION BEHIND THE FRONT TONIGHT WILL RESULT IN GUSTY NORTHWEST WINDS. THE COOLER AIR MASS COMING IN WILL HOLD LOW TEMPERATURES BELOW NORMAL. && .SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/... AS OF 327 AM EDT WEDNESDAY... HIGH PRESSURE STRENGTHENS AND STRETCHES INTO THE MIDDLE ATLANTIC THURSDAY AND THURSDAY NIGHT. ONE FINAL SHRTWV WITH SCANT MOISTURE CUTTING THROUGH WEST VA WILL THROW SOME CLOUDS BRIEFLY INTO SE WEST VA LATE THURSDAY AFTERNOON BEFORE DEPARTING THURSDAY NIGHT. FRIDAY MORNING LOOKS LIKE A CHILLY ONE WITH SOME MINS NEAR FREEZING AT THE COLDEST SPOTS AND POTENTIALLY NEAR THE MIDDLE 30S ACROSS THE VIRGINIA PIEDMONT WHICH MAY LEAD TO SOME PATCHY FROST. AS THE HIGH DEPARTS LATER FRIDAY SOME HIGH CLOUDS ARRIVE BEFORE MOISTURE INCREASES AND WINDS BEGIN TO TAKE ON AN EASTERLY COMPONENT INTO THE WEEKEND. PINPOINTING POPS FOR THIS WEEKEND REALLY TOUGH RIGHT NOW WITH MODELS NOT SHOWING A LOT OF MEASURABLE PRECIP SAVE THE NC/VA BORDER. BUT...WOULD THINK SE TO ESE FLOW AND ABUNDANT MOISTURE WOULD BE ENOUGH FOR SOME LIGHT RAIN SATURDAY OR SATURDAY NIGHT...FURTHER NORTH THAN MOST MODELS DEPICT. THE 0Z ECMWF CONTINUES TO BE THE WETTEST SOLUTION BUT EVEN IT HAS NOW SHIFTED THE PRECIP FURTHER SOUTH. NONETHELESS...GUIDANCE FOR MAX T SATURDAY SEEMED SEVERAL DEGREES TOO WARM CONSIDERING ALL OF THE ABOVE...SO WENT BELOW THE MEX MOS NUMBERS...SUBSTANTIALLY SO IN THE TYPICAL WEDGE AREAS. && .LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 355 PM EDT THURSDAY... CONSIDERABLE DIFFERENCES REMAIN AMONG THE GFS AND ECMWF DURING THE EXTENDED PERIODS...BUT ANY WAY YOU LOOK AT IT...IT IS GOING TO BE WET AND UNSEASONABLY COOL. A VIGOROUS SOUTHERN STREAM DISTURBANCE IS STILL SLATED TO MOVE INTO THE REGION FROM THE WEST. IT IS THE SUBSEQUENT MOVEMENT/DEVELOPMENT OF THIS SYSTEM THROUGH THE WEEKEND INTO EARLY NEXT WEEK THAT BECOMES THE QUESTION. THE GFS HAS IN GENERAL SHOWN MORE CONSISTENCY WITH THE EVOLUTION OF THIS SYSTEM THAN THE ECMWF. EACH RUN OF THE ECMWF DEVELOPS A CUTOFF IN A DIFFERENT LOCATION...WHICH IS RESULTING IN LOWERING CONFIDENCE IN ANY ONE SOLUTION FROM THAT MODEL. HOWEVER...BOTH THE GFS AND ECMWF GIVE SOME HINT OF AT LEAST WEAK CUTOFF LOW PRESSURE DEVELOPING ACROSS THE SOUTHEAST STATES IN A WEAKNESS AREA. THEREFORE...HAVE KEPT LIKELY POPS SAT-SUN...THEN TAPER TO MOSTLY CHANCE POPS DURING THE LATER PERIODS. THE LATEST ECMWF HAS DEFINITELY TRENDED TOWARD A DRIER/WEAKER SOLUTION. INSTABILITY IS NIL THROUGH THE PERIOD AND WITH BOTH MODELS THERE IS A STRONG SIGNAL FOR A WEDGE REINFORCED...HENCE IN SITU AS WELL. HAVE FAVORED THE MUCH COOLER ECMWF GRIDS THROUGHOUT THE EXTENDED PERIODS. && .AVIATION /09Z WEDNESDAY THROUGH SUNDAY/... AS OF 145 AM EDT WEDNESDAY... HAVE ADDED LLWS TO ALL TAFS...BCB/BLF/LWB/ROA/LYH/DAN...FOR THE BEGINNING OF THE FORECAST PERIOD SINCE THE LOW LEVEL JET WILL BE INCREASING FROM THE SOUTHWEST AHEAD OF THE APPROACHING COLD FRONT. BUFKIT INDICATED JET WOULD BE IN THE 32 TO 37 KNOT RANGE FROM THE SOUTHWEST. CLOUDS WILL INCREASE THROUGHOUT THE DAY...ALTHOUGH CEILINGS WILL REMAIN VFR. ONCE INVERSION BREAKS THIS MORNING AND MIXING BEGINS...WINDS WILL GUST 20 TO 30 KNOTS FROM THE SOUTHWEST. LOW PRESSURE MOVING ACROSS THE GREAT LAKES WILL BRING A COLD FRONT THROUGH THE REGION THIS EVENING. EXPECT FRONTAL PASSAGE AND WIND SHIFT TO THE NORTHWEST AROUND 23Z/7PM AT BLF AND LWB AND BETWEEN 00Z/8PM AND 03Z/11PM AT BCB/ROA/DAN/LYH. LESS CERTAIN ABOUT HOW MUCH PRECIPITATION WILL BE AHEAD OF THE FRONT...OR HOW MUCH WILL FALL BEHIND THE FRONT. CEILINGS MAY DROP TO MVFR AT BLF AND LWB BEHIND THE FRONT. THE SHOWERS MAY NEVER REACH DAN AND LYH WITH NORTHWEST DOWNSLOPE WINDS AND THE PRECIPITATION MAINLY BEHIND THE BOUNDARY. HIGH PRESSURE WILL BUILD IN QUICKLY IN THE WAKE OF THE COLD FRONT FOR THURSDAY AND FRIDAY. ANY MVFR CEILINGS WILL BE WEST OF THE BLUE RIDGE...AND WILL IMPROVE TO VFR THURSDAY MORNING. THIS WEEKEND WILL BE UNSETTLED WITH PERIODS OF SHOWERS BEGINNING SATURDAY AFTERNOON. EXPECT PERIODS OF IFR/MVFR CONDITIONS SATURDAY AFTERNOON THROUGH THE REST OF THE WEEKEND. && .FIRE WEATHER... AS OF 515 AM EDT WEDNESDAY... BREEZY SOUTHWEST WINDS AHEAD OF AN APPROACHING COLD FRONT TODAY. SOUTHWEST WINDS OF 10 TO 15 MPH WITH GUSTS OF 20 TO 30 MPH ARE LIKELY BY THIS AFTERNOON. THE WIND WILL ABRUPTLY SHIFT TO THE NORTHWEST WITH THE PASSAGE OF THE FRONT THIS EVENING. THE FRONT IS EXPECTED TO CROSS THE MOUNTAINS BETWEEN 6-9PM...THEN MOVE EAST OF THE BLUE RIDGE AND ACROSS THE PIEDMONT BEFORE MIDNIGHT. THE CHANCE OF RAIN MOVES BACK INTO THE FORECAST AREA AGAIN ON SATURDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/PM/WP SHORT TERM...KM LONG TERM...RAB AVIATION...AMS FIRE WEATHER...AMS/PM
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1044 PM CDT THU APR 25 2013 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .SHORT TERM...TONIGHT AND FRIDAY ISSUED AT 231 PM CDT THU APR 25 2013 LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN AREA OF LOW PRESSURE MOVING INTO SE ONTARIO EARLY THIS AFTERNOON AND A SURFACE RIDGE AXIS SHIFTING EAST INTO WESTERN WISCONSIN. PLENTY OF CLOUD COVER LEFT OVER BEHIND THE SURFACE LOW OVER THE STATE...THANKS TO RESIDUAL MOISTURE AND STEEP LOW LEVEL LAPSE RATES. EVEN SCATTERED LIGHT RAIN SHOWERS OR SPRINKLES DEVELOPED OVER FAR NE WISCONSIN EARLY THIS AFTERNOON. CLEARING IS BEGINNING TO MOVE ACROSS THE MISSISSIPPI RIVER...AND SHOULD ACCELERATE NE THROUGH THE REST OF THE AFTERNOON. FURTHER WEST...THE NEXT SHORTWAVE IS ENTERING THE NORTHERN PLAINS...AND CLOUDS ARE PUSHING INTO THE DAKOTAS. PRECIP CHANCES WITH THIS SHORTWAVE ARE THE MAIN FORECAST CONCERNS LATE TONIGHT INTO TOMORROW MORNING. TONIGHT...RATHER BAGGY SURFACE RIDGE AXIS WILL WORK FROM WEST TO EAST ACROSS THE REGION LATE THIS AFTERNOON AND THIS EVENING. WITH LOSS OF CYCLONIC FLOW AND DIURNAL HEATING...THINK CLOUDS WILL DISSIPATE BY MID-EVENING WHICH WILL SETUP A FEW HOUR PERIOD OF MOSTLY CLEAR SKIES AND LIGHT WINDS. THESE CONDITIONS WILL BE CONDUCIVE FOR TEMPS TO TUMBLE FAIRLY QUICKLY THIS EVENING OVER N-C WISCONSIN WHERE THERE REMAINS SNOW PACK. MEANWHILE UPSTREAM...SHORTWAVE TROUGH OVER NE MONTANA WILL SWING SE TOWARDS THE WESTERN GREAT LAKES BY MORNING. RATHER BEEFY 40-50KT LLJ WILL DEVELOP AHEAD OF THE SHORTWAVE WITH ITS NOSE MOVING OVER NORTH-CENTRAL WISCONSIN LATE TONIGHT. WILL INCREASE POPS INTO THE LIKELY RANGE. TEMPS WILL BOTTOM OUT EARLY OVERNIGHT BEFORE WINDS ALOFT PICK UP WITH THE APPROACH OF THE LLJ. WILL GO WITH MID 20S NORTH TO MID 30S SOUTH. FRIDAY...THE NOSE OF THE LLJ WILL PASS OVER NE WISCONSIN IN THE 12-15Z TIME PERIOD AND WILL INCREASE POPS TO LIKELY. PRECIP SHOULD EXIT THE AREA BY MID MORNING AND WILL SEE A PARTIAL DECREASE IN CLOUDS AS LIFT ASSOCIATED WITH THE WARM ADVECTION DEPARTS. RATHER BAGGY 850-700MB THETAE AXIS WILL REMAIN OVERHEAD FROM CENTRAL TO NORTHEAST WISCONSIN FOR THE REST OF THE DAY. WITH AMPLE DAYTIME HEATING AND GOOD MIXING...SHOULD BE AMPLE TO TAP INTO THIS MOISTURE ALOFT FOR AT LEAST PARTLY CLOUDY/PARTLY SUNNY CONDITIONS IN THE AFTERNOON. SOME MODELS SPIT OUT PRECIP WITHIN THIS THETAE AXIS...BUT CONVERGENCE IS VERY WEAK AND CAPE IS AROUND 100 J/KG AT MOST. SEEMS LIKE A BETTER CHANCE FOR PRECIP TO OCCUR IS SOUTHWEST OF THE REGION IN AN AREA OF BETTER CONVERGENCE. RESULTING SHOWERS WILL THEN HAVE POTENTIAL TO ADVECT INTO CENTRAL OR EAST-CENTRAL WISCONSIN LATE IN THE AFTERNOON. WILL KEEP AN ISOLATED SHOWER MENTION BUT DROP POPS EVERYWHERE ELSE. 925MB TEMPS ARGUE FOR HIGHS NEAR 70F...SO WILL INCREASE HIGHS A DEGREE OR TWO. HIGHS MAINLY IN THE LOW TO MID 60S. .LONG TERM...FRIDAY NIGHT THROUGH THURSDAY ISSUED AT 231 PM CDT THU APR 25 2013 THE MAIN FCST CONCERNS INCLUDE MILDER TEMPERATURES FOR THE WEEKEND... THEN PCPN TRENDS FOR NEXT WEEK. A WEAKENING COLD FRONT WILL BE SAGGING SE ACROSS THE AREA ON FRIDAY NIGHT. WILL ONLY KEEP A SLIGHT CHC OF SHOWERS DURING THE EARLY EVENING FOR THE SE HALF OF THE FORECAST AREA...THEN DRY FOR THE REST OF THE NIGHT. DECREASING CLOUDS...LIGHT WINDS AND LINGERING SNOW COVER WILL SET THE STAGE FOR SOME FOG OVER NC/FAR NE WI LATE FRIDAY NIGHT. WENT WITH A MAINLY DRY FCST FROM SATURDAY THROUGH SUNDAY. ISOLD SHOWERS MAY DEVELOP IN THE VCNTY OF THE OLD FRONTAL BOUNDARY ON SATURDAY AFTERNOON...BUT CAPE IS ONLY EXPECTED TO BE AROUND 100 J/KG...SO WILL KEEP THE DRY FCST INTACT. THE NEXT FRONT IS EXPECTED TO APPROACH OUR FAR NW COUNTIES LATE SUNDAY AFTERNOON... A LITTLE FASTER THAN EXPECTED YESTERDAY...SO KEPT A SMALL POP THERE. OTHERWISE...PARTLY CLOUDY SKIES AND MIXING THROUGH 800-850 MB SHOULD SUPPORT HIGHS IN THE MID 60S ON SATURDAY...AND UPPER 60S TO LOWER 70S ON SUNDAY. THE EXCEPTION WILL BE NEAR LAKE MICHIGAN...WHERE SOUTH WINDS WILL KEEP HIGH TEMPS 10-15 DEGREES COOLER. THE AFOREMENTIONED FRONT IS EXPECTED TO MOVE THROUGH GRB CWA SUNDAY NIGHT INTO MONDAY...THEN EVENTUALLY LIFT BACK TO THE NORTH AS A WARM FRONT MONDAY NIGHT INTO TUESDAY. SCT SHRA/ISOLD TSRA CAN BE EXPECTED DURING THIS PERIOD. TUESDAY LOOKS LIKE THE WARMEST DAY OF THE WEEK...WITH TEMPS APPROACHING THE MIDDLE 70S IN CENTRAL WI. A THIRD STRONGER COLD FRONT IS EXPECTED TO ARRIVE LATE TUES INTO TUES NIGHT...THEN MOVE SLOWLY ACROSS THE AREA INTO WEDS OR WEDS NIGHT. THE MOVEMENT WILL BE SLOWED BY THE DEVELOPMENT OF A MORE AMPLIFIED SW FLOW...AS A DEEPENING UPPER TROF APPROACHES FROM THE PLAINS. THIS FRONT SHOULD HAVE BETTER MOISTURE TO WORK WITH...AS IT SHOULD EVENTUALLY TAP INTO THE GULF. MID-RANGE POPS SEEM REASONABLE FOR NOW...BUT HIGHER POPS MAY EVENTUALLY BE NEEDED. MAIN FOCUS FOR TSTMS WILL BE TUES NIGHT INTO WEDS...BUT NOT EXPECTING ANY SEVERE WEATHER AT THIS TIME. COOLER TEMPERATURES WILL ARRIVE WEDS INTO WEDS NGT...WITH A MIXTURE OF RAIN/SNOW SHOWERS POSSIBLE OVER NC WI LATE WED NGT. EXPECT MAX TEMPS TO DROP BACK BLO NORMAL AGAIN BY THURSDAY. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1043 PM CDT THU APR 25 2013 MIDDLE AND HIGH CLOUDS WILL INCREASE AHEAD OF A WEAKENING FRONTAL SYSTEM THAT WILL STALL OVER SOUTHERN WISCONSIN FRIDAY AFTERNOON. IT MAY PRODUCE SCATTERED SHOWERS LATE TONIGHT AND FRIDAY MORNING BUT CEILINGS MAY REMAIN VFR EVEN WITH THE SHOWER ACTIVITY. LOW LEVEL WIND SHEAR POSSIBLE IN NORTHERN WISCONSIN THIS MORNING AND IN EAST CENTRAL WISCONSIN FRIDAY EVENING. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......KIECKBUSCH AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
624 PM CDT THU APR 25 2013 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE .SHORT TERM...TONIGHT AND FRIDAY ISSUED AT 231 PM CDT THU APR 25 2013 LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN AREA OF LOW PRESSURE MOVING INTO SE ONTARIO EARLY THIS AFTERNOON AND A SURFACE RIDGE AXIS SHIFTING EAST INTO WESTERN WISCONSIN. PLENTY OF CLOUD COVER LEFT OVER BEHIND THE SURFACE LOW OVER THE STATE...THANKS TO RESIDUAL MOISTURE AND STEEP LOW LEVEL LAPSE RATES. EVEN SCATTERED LIGHT RAIN SHOWERS OR SPRINKLES DEVELOPED OVER FAR NE WISCONSIN EARLY THIS AFTERNOON. CLEARING IS BEGINNING TO MOVE ACROSS THE MISSISSIPPI RIVER...AND SHOULD ACCELERATE NE THROUGH THE REST OF THE AFTERNOON. FURTHER WEST...THE NEXT SHORTWAVE IS ENTERING THE NORTHERN PLAINS...AND CLOUDS ARE PUSHING INTO THE DAKOTAS. PRECIP CHANCES WITH THIS SHORTWAVE ARE THE MAIN FORECAST CONCERNS LATE TONIGHT INTO TOMORROW MORNING. TONIGHT...RATHER BAGGY SURFACE RIDGE AXIS WILL WORK FROM WEST TO EAST ACROSS THE REGION LATE THIS AFTERNOON AND THIS EVENING. WITH LOSS OF CYCLONIC FLOW AND DIURNAL HEATING...THINK CLOUDS WILL DISSIPATE BY MID-EVENING WHICH WILL SETUP A FEW HOUR PERIOD OF MOSTLY CLEAR SKIES AND LIGHT WINDS. THESE CONDITIONS WILL BE CONDUCIVE FOR TEMPS TO TUMBLE FAIRLY QUICKLY THIS EVENING OVER N-C WISCONSIN WHERE THERE REMAINS SNOW PACK. MEANWHILE UPSTREAM...SHORTWAVE TROUGH OVER NE MONTANA WILL SWING SE TOWARDS THE WESTERN GREAT LAKES BY MORNING. RATHER BEEFY 40-50KT LLJ WILL DEVELOP AHEAD OF THE SHORTWAVE WITH ITS NOSE MOVING OVER NORTH-CENTRAL WISCONSIN LATE TONIGHT. WILL INCREASE POPS INTO THE LIKELY RANGE. TEMPS WILL BOTTOM OUT EARLY OVERNIGHT BEFORE WINDS ALOFT PICK UP WITH THE APPROACH OF THE LLJ. WILL GO WITH MID 20S NORTH TO MID 30S SOUTH. FRIDAY...THE NOSE OF THE LLJ WILL PASS OVER NE WISCONSIN IN THE 12-15Z TIME PERIOD AND WILL INCREASE POPS TO LIKELY. PRECIP SHOULD EXIT THE AREA BY MID MORNING AND WILL SEE A PARTIAL DECREASE IN CLOUDS AS LIFT ASSOCIATED WITH THE WARM ADVECTION DEPARTS. RATHER BAGGY 850-700MB THETAE AXIS WILL REMAIN OVERHEAD FROM CENTRAL TO NORTHEAST WISCONSIN FOR THE REST OF THE DAY. WITH AMPLE DAYTIME HEATING AND GOOD MIXING...SHOULD BE AMPLE TO TAP INTO THIS MOISTURE ALOFT FOR AT LEAST PARTLY CLOUDY/PARTLY SUNNY CONDITIONS IN THE AFTERNOON. SOME MODELS SPIT OUT PRECIP WITHIN THIS THETAE AXIS...BUT CONVERGENCE IS VERY WEAK AND CAPE IS AROUND 100 J/KG AT MOST. SEEMS LIKE A BETTER CHANCE FOR PRECIP TO OCCUR IS SOUTHWEST OF THE REGION IN AN AREA OF BETTER CONVERGENCE. RESULTING SHOWERS WILL THEN HAVE POTENTIAL TO ADVECT INTO CENTRAL OR EAST-CENTRAL WISCONSIN LATE IN THE AFTERNOON. WILL KEEP AN ISOLATED SHOWER MENTION BUT DROP POPS EVERYWHERE ELSE. 925MB TEMPS ARGUE FOR HIGHS NEAR 70F...SO WILL INCREASE HIGHS A DEGREE OR TWO. HIGHS MAINLY IN THE LOW TO MID 60S. .LONG TERM...FRIDAY NIGHT THROUGH THURSDAY ISSUED AT 231 PM CDT THU APR 25 2013 THE MAIN FCST CONCERNS INCLUDE MILDER TEMPERATURES FOR THE WEEKEND... THEN PCPN TRENDS FOR NEXT WEEK. A WEAKENING COLD FRONT WILL BE SAGGING SE ACROSS THE AREA ON FRIDAY NIGHT. WILL ONLY KEEP A SLIGHT CHC OF SHOWERS DURING THE EARLY EVENING FOR THE SE HALF OF THE FORECAST AREA...THEN DRY FOR THE REST OF THE NIGHT. DECREASING CLOUDS...LIGHT WINDS AND LINGERING SNOW COVER WILL SET THE STAGE FOR SOME FOG OVER NC/FAR NE WI LATE FRIDAY NIGHT. WENT WITH A MAINLY DRY FCST FROM SATURDAY THROUGH SUNDAY. ISOLD SHOWERS MAY DEVELOP IN THE VCNTY OF THE OLD FRONTAL BOUNDARY ON SATURDAY AFTERNOON...BUT CAPE IS ONLY EXPECTED TO BE AROUND 100 J/KG...SO WILL KEEP THE DRY FCST INTACT. THE NEXT FRONT IS EXPECTED TO APPROACH OUR FAR NW COUNTIES LATE SUNDAY AFTERNOON... A LITTLE FASTER THAN EXPECTED YESTERDAY...SO KEPT A SMALL POP THERE. OTHERWISE...PARTLY CLOUDY SKIES AND MIXING THROUGH 800-850 MB SHOULD SUPPORT HIGHS IN THE MID 60S ON SATURDAY...AND UPPER 60S TO LOWER 70S ON SUNDAY. THE EXCEPTION WILL BE NEAR LAKE MICHIGAN...WHERE SOUTH WINDS WILL KEEP HIGH TEMPS 10-15 DEGREES COOLER. THE AFOREMENTIONED FRONT IS EXPECTED TO MOVE THROUGH GRB CWA SUNDAY NIGHT INTO MONDAY...THEN EVENTUALLY LIFT BACK TO THE NORTH AS A WARM FRONT MONDAY NIGHT INTO TUESDAY. SCT SHRA/ISOLD TSRA CAN BE EXPECTED DURING THIS PERIOD. TUESDAY LOOKS LIKE THE WARMEST DAY OF THE WEEK...WITH TEMPS APPROACHING THE MIDDLE 70S IN CENTRAL WI. A THIRD STRONGER COLD FRONT IS EXPECTED TO ARRIVE LATE TUES INTO TUES NIGHT...THEN MOVE SLOWLY ACROSS THE AREA INTO WEDS OR WEDS NIGHT. THE MOVEMENT WILL BE SLOWED BY THE DEVELOPMENT OF A MORE AMPLIFIED SW FLOW...AS A DEEPENING UPPER TROF APPROACHES FROM THE PLAINS. THIS FRONT SHOULD HAVE BETTER MOISTURE TO WORK WITH...AS IT SHOULD EVENTUALLY TAP INTO THE GULF. MID-RANGE POPS SEEM REASONABLE FOR NOW...BUT HIGHER POPS MAY EVENTUALLY BE NEEDED. MAIN FOCUS FOR TSTMS WILL BE TUES NIGHT INTO WEDS...BUT NOT EXPECTING ANY SEVERE WEATHER AT THIS TIME. COOLER TEMPERATURES WILL ARRIVE WEDS INTO WEDS NGT...WITH A MIXTURE OF RAIN/SNOW SHOWERS POSSIBLE OVER NC WI LATE WED NGT. EXPECT MAX TEMPS TO DROP BACK BLO NORMAL AGAIN BY THURSDAY. && .AVIATION...FOR 00Z TAF ISSUANCE ISSUED AT 624 PM CDT THU APR 25 2013 MAINLY CLEAR SKIES WITH GOOD VISIBILITY THROUGH THE EARLY MORNING HOURS. THEN CLOUDS WILL ARRIVE AHEAD OF A FRONTAL SYSTEM WHICH WILL PRODUCE RAIN SHOWERS BUT MOSTLY VFR CEILINGS AND VISIBILITIES LATE TONIGHT AND FRIDAY MORNING. PARTIAL CLEARING EXPECTED FRIDAY AFTERNOON ESPECIALLY IN NORTHERN WISCONSIN. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......KIECKBUSCH AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
348 PM CDT WED APR 24 2013 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 347 PM CDT WED APR 24 2013 AT 3 PM...A COLD FRONT EXTEND FROM INTERNATIONAL FALLS TO SIOUX FALLS SOUTH DAKOTA. TEMPERATURES AHEAD OF THIS FRONT RANGED FROM THE MID 40S TO MID 50S. MEANWHILE TEMPERATURES IN THE WAKE OF THIS FRONT WERE IN THE 30S. THE 24.12Z AND 24.18Z MODELS ARE A BIT SLOWER AT MOVING THIS FRONT THROUGH THE REGION TONIGHT...THUS DELAYED THE PRECIPITATION ONSET AND ENDING BY ABOUT 3 HOURS. AHEAD OF THE STRONG PV ANOMALY...BUFKIT SOUNDINGS SHOW AN INVERTED V SOUNDING...AND THE STEEP AND UNSTABLE 950-400 MB LAPSE RATES. AS A RESULT...EXPECT THE WINDS TO RATHER GUSTY THIS EVENING. WIND GUSTS WILL RANGE FROM 30 TO 35 MPH. WITH CAPES UP TO 100 J/KG...THERE WILL BE THE POTENTIAL FOR A FEW ISOLATED THUNDERSTORMS. AS TEMPERATURES COOL IN THE WAKE OF THIS FRONT...THERE MAY BE A BRIEF PERIOD OF SNOW. LITTLE...IF ANY...SNOW ACCUMULATIONS ARE EXPECTED. LATE TONIGHT AND THURSDAY...A WEAK RIDGE OF HIGH PRESSURE WILL BUILD ACROSS THE AREA. THIS HIGH WILL PROVIDE WILL PROVIDE PARTLY TO MOSTLY SUNNY SKIES. WITH 850 MB TEMPERATURES DURING THE AFTERNOON FAIRLY SIMILAR TO THIS AFTERNOON...EXPECT VERY LITTLE TEMPERATURE CHANGE BETWEEN THE 2 AFTERNOONS. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 347 PM CDT WED APR 24 2013 ON THURSDAY NIGHT...A SHORT WAVE TROUGH WILL MOVE SOUTHEAST ACROSS NORTHERN MINNESOTA AND NORTHERN WISCONSIN. THIS FRONT WILL DRAG A WEAK COLD FRONT INTO THE REGION ON THURSDAY NIGHT...AND IT WILL LINGER ACROSS THE SOUTHERN AND EASTERN PORTIONS OF THE FORECAST AREA THROUGH FRIDAY EVENING. 925 MB AND 850 MB MOISTURE TRANSPORT INTO THIS FRONT IS FAIRLY WEAK. THE MODELS GENERATE SCATTERED SHOWERS ALONG THIS FRONT. THIS IS LIKELY DUE TO THE 0-3 KM MOST UNSTABLE CAPES UP TO 250 J/KG. AS A RESULT...JUST KEPT A 20 TO 30 PERCENT CHANCE OF SHOWERS IN THE FORECAST. FOR THE UPCOMING WEEKEND...AN UPPER LEVEL RIDGE WILL PROVIDE DRY WEATHER. SOUTHERLY WINDS WILL BRING WARM AIR INTO THE REGION. 850 MB TEMPERATURES WILL RANGE FROM 6 TO 10C ON SATURDAY...AND FROM 10 TO 14C ON SUNDAY. THIS WILL RESULT IN HIGH TEMPERATURES IN THE MID AND UPPER 60S ON SATURDAY...AND LOWER 70S ON SUNDAY. ON SUNDAY NIGHT...A CANADIAN COLD FRONT WILL MOVE SOUTHEAST THROUGH THE FORECAST AREA. THIS FRONT WILL THEN RETURN BACK TO THE NORTH ON MONDAY. THE COMBINATION OF WEAK TO MODERATE MOISTURE TRANSPORT INTO THIS FRONT AND 0-3 KM MOST UNSTABLE CAPES OF 500 TO 1000 J/KG WILL RESULT IN THE DEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS. IF THIS FRONT IS ABLE TO MOVE MUCH FASTER NORTH OF MONDAY...THERE WOULD BE THE POTENTIAL FOR SOME MID 70S TO OCCUR SOUTH OF THE INTERSTATE 90 CORRIDOR. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1225 PM CDT WED APR 24 2013 TWO AREAS OF CONCERN FOR THIS TAF CYCLE. FIRST IS GUST POTENTIAL LATE THIS AFTERNOON AND EVENING AND THE SECOND IS THE POTENTIAL FOR STRATUS LATER TONIGHT. SHORTWAVE TROUGH WILL PUSH COLD FRONT ACROSS THE SITES THIS EVENING. BAND OF SHOWERS EXPECTED AHEAD OF THIS FEATURE TO AFFECT THE KRST TAF SITES AROUND 00Z-01Z AND KLSE IN THE 02Z-03Z TIME FRAME. EXPECT CEILINGS TO LOWER LATE THIS AFTERNOON AND INTO THE EVENING...BUT WITH THE DRY LOW LEVELS WILL REMAIN IN THE VFR CATEGORY. RATHER STEEP LOW LEVEL LAPSE RATES WITH THE 24.15Z RAP SOUNDING SHOWING AN INVERTED V-SOUNDING FAVORABLE FOR MIXING HIGHER GUSTS TO THE SURFACE...WITH SOME ENHANCEMENT WITH THE STRONGER SHOWERS/ISOLATED THUNDERSTORMS. THE 24.15Z ARXLAPS AND 24.15Z HRRR BOTH SHOWING GUST POTENTIAL BETWEEN 25 AND 35 KNOTS IN THE SHOWERS...BUT THESE WOULD BE ISOLATED AT BEST AND WILL NOT INCLUDE THE HIGHER GUSTS IN THE TAFS. NEXT CONCERN IS POST FRONTAL STRATUS. NOT MUCH SHOWING UP RIGHT NOW OVER THE DAKOTAS AND LATEST GUIDANCE HAVE BACKED OFF ON THE LOWER CEILING POTENTIAL...ALTHOUGH 24.12Z NAM AND 24.15Z RAP SOUNDINGS SHOWING SOME MOISTURE AROUND 925 MPH. WILL KEEP MENTION OF JUST A SCATTERED DECK BETWEEN 015-025K FEET AT THIS TIME. OTHERWISE...SKIES SHOULD WILL BECOME CLEAR AFTER 12Z THURSDAY. && .HYDROLOGY...WARMING TEMPERATURES THIS WEEKEND ISSUED AT 347 PM CDT WED APR 24 2013 HIGHS IN THE 60S AND 70S AND LOWS IN THE 40S AND 50S FROM FRIDAY THROUGH MONDAY WILL RESULT IN A RAPID INCREASE IN THE SNOW MELT RATE AND RUNOFF ACROSS CENTRAL MINNESOTA AND NORTHERN WISCONSIN. THIS SNOW MELT WILL PROVIDE RISES ALONG THE CHIPPEWA...ST CROIX AND MISSISSIPPI RIVERS. THIS WILL EVENTUALLY FLOW DOWNSTREAM INTO THE OUR AREA BY EARLY MAY. RIVER FORECASTS AND STATEMENTS WILL ADDRESS THE MISSISSIPPI RIVER RISES AS DETAILS OF THE FINAL MELT AND INFLOWS TO THE TRIBUTARY RIVERS BECOME CLEARER THIS WEEKEND AND EARLY NEXT WEEK. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...RABERDING HYDROLOGY...BOYNE
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND THURSDAY ISSUED AT 245 PM CDT WED APR 24 2013 LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A HIGH PRESSURE RIDGE AXIS STRETCHING FROM THE SOUTHERN GREAT PLAINS ACROSS NE WISCONSIN TO JAMES BAY EARLY THIS AFTERNOON. QUIET WEATHER EXISTS ACROSS THE FORECAST AREA CURRENTLY...BUT MORE ACTIVE CONDITIONS EXIST UPSTREAM OVER NE MINNESOTA. A WEAK SHORTWAVE IS PUSHING AN AREA OF RAIN AND SNOW SOUTH OF DULUTH AND INTO NW WISCONSIN. BUT THE MAIN SHORTWAVE TROUGH IS STILL OUT OVER NORTH DAKOTA WHERE SCATTERED RAIN AND SNOW SHOWERS ARE FLYING. IN THE HEAVIER SNOW SHOWERS...VISIBILITIES ARE FALLING TO AROUND A HALF TO THREE QUARTERS OF A MILE. AS THESE SHORTWAVE TROUGHS PASS ACROSS THE FORECAST AREA TONIGHT...PRECIP CHANCES AND AMOUNTS ARE THE MAIN FORECAST CONCERNS. TONIGHT...THE MAIN SHORTWAVE TROUGH WILL SHARPEN AS IT DIGS ACROSS THE NORTHERN MISSISSIPPI THIS EVENING AND THE STATE OF WISCONSIN TONIGHT. A WEAK LITTLE WAVE OVER NORTHERN MINNESOTA WILL PUSH A LEAD AREA OF PRECIP ENE ACROSS NORTH-CENTRAL WISCONSIN EARLY THIS EVENING. DESPITE DEWPOINTS IN THE TEENS IN THIS REGION CURRENTLY...PRECIP RATES LOOK IMPRESSIVE ENOUGH ON RADAR TO THINK PRECIP WILL REACH THE GROUND EARLY THIS EVENING. THE PRECIP WILL BE ARRIVING JUST AFTER PEAK HEATING...SO THINK PRECIP WILL START OUT AS RAIN...THOUGH CANT RULE OUT SNOW FLAKES MIXING IN WITH THE RAIN DROPS WITHIN THE HEAVIER SHOWERS. THE MAIN SHORTWAVE WILL THEN MOVE ACROSS THE REGION LATE THIS EVENING THROUGH THE MIDDLE OF THE OVERNIGHT PERIOD. SATELLITE AND RADAR UPSTREAM LOOK RATHER SHOWERY...PARTLY CONTRIBUTED TO STEEP MID-LEVEL LAPSE RATES AROUND 8 C/KM. THINK PRECIP WILL REMAIN SHOWERY TONIGHT DESPITE LOSS OF DIURNAL HEATING. SURFACE WET BULB TEMPS STRUGGLE TO FALL BELOW FREEZING DURING THE PERIOD THE PRECIP IS EXPECTED TO FALL...SO PTYPE WILL REMAIN UNCERTAIN. THINK PRECIP WILL MAINLY BE RAIN OR A RAIN/SNOW MIX THIS EVENING...CHANGING OVER TO SNOW AFTER MIDNIGHT AS SLIGHTLY COLDER AIR MOVES IN BEHIND A SURFACE TROUGH. BUT THE ABOVE FREEZING WET BULB TEMPS SUGGEST ACCUMS WILL BE LIMITED...PERHAPS A HALF INCH TO AN INCH ON GRASSY SURFACES (HIGHER NORTH). PRECIP TO EXIT LATE TONIGHT AND SKIES MAY PARTIALLY CLEAR OVER CENTRAL AND EAST-CENTRAL WISCONSIN. LOWS IN THE UPPER 20S NORTH TO MID 30S SOUTH. THURSDAY...SOME CLOUDS TO LINGER THURSDAY MORNING AND WILL GO WITH A PARTLY TO MOSTLY CLOUDY START TO THE DAY AS RESIDUAL MOISTURE AND CYCLONIC FLOW REACTS WITH DIURNAL HEATING. HOWEVER...MIXING AND A WEAK 850MB RIDGE AXIS SHOULD LEAD TO DECREASING CLOUDS IN THE AFTERNOON. HIGHS A DEGREE OR TWO COOLER THAN TODAY. .LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY ISSUED AT 245 PM CDT WED APR 24 2013 MAIN FCST CONCERNS ARE PCPN TRENDS THU NGT INTO FRIDAY...AND DURING THE EARLY TO MID PART OF THE NEXT WORK WEEK...AND FINALLY SOME WARMER TEMPERATURES. COOL NORTHWEST FLOW WILL BE REPLACED BY A ZONAL WESTERLY FLOW BY THE WEEKEND...THEN BECOME MORE AMPLIFIED WITH SOUTHWEST FLOW AS A TROF DEEPENS OVER THE ROCKIES AND NORTHERN PLAINS DURING THE EARLY TO MID PART OF THE NEXT WORK WEEK. THE BIGGEST CHANGE WILL BE MUCH WARMER AND ABOVE NORMAL TEMPS...WITH HIGHS WARMING INTO THE 60S AND LOWER 70S FOR MOST OF THE PERIOD. THE WARMEST DAYS LOOK LIKE THEY WILL OCCUR ON MONDAY AND TUESDAY. FAIRLY STRONG WAA/ISENT LIFT WILL DEVELOP THURSDAY NIGHT...AND CONTINUE INTO FRIDAY MORNING. IN ADDITION...A S/W TROF WILL TRACK ACROSS THE REGION LATE THURSDAY NIGHT AND FRIDAY. RH/OMEGA TIMESECTIONS INDICATE THAT MOISTURE WILL BE SOMEWHAT LACKING... WITH PCPN NOT DEVELOPING UNTIL AFTER 09Z/FRI IN OUR WESTERN COUNTIES. LOW-LEVEL THICKNESSES AND TEMPS INDICATE THAT PCPN SHOULD BE MAINLY RAIN ACROSS CENTRAL WI...BUT A LIGHT MIX OF SNOW/SLEET/RAIN MAY BRIEFLY OCCUR IN NC WI. DO NOT PLAN TO CARRY A MIX INTO FRIDAY... AND WILL JUST HAVE A CHANCE OF SHOWERS ACROSS THE CWA. GENERALLY DRY CONDITIONS ARE EXPECTED FROM FRIDAY NIGHT THROUGH SUNDAY...MAKING FOR A VERY NICE AND MILD WEEKEND. A WEAKENING COLD FRONT AND RRQ OF AN UPPER LEVEL JET WILL BRING A CHANCE OF SHOWERS/ISOLD TSTMS TO OUR NW COUNTIES SUNDAY NIGHT. THE FRONT IS EXPECTED TO BECOME ORIENTED MORE WEST TO EAST ACROSS THE AREA ON MONDAY...THEN LIFT NORTH AS A WARM FRONT ON MONDAY NIGHT AS LOW PRESSURE ORGANIZES IN THE NORTHERN PLAINS. THE THREAT OF SHOWERS AND TSTMS WILL CONTINUE ALONG THIS BOUNDARY. A STRONGER... BUT SLOW MOVING COLD FRONT WILL EDGE TOWARD THE AREA TUESDAY INTO WEDNESDAY...WITH MAINLY POST-FRONTAL PCPN EXPECTED. PCPN ASSOCIATED WITH THIS FEATURE SHOULD ARRIVE IN OUR NW COUNTIES TUES NGT...AND ACROSS THE REST OF THE AREA ON WEDNESDAY. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1236 PM CDT WED APR 24 2013 VFR CONDITIONS FOR THIS AFTERNOON WITH INCREASING CLOUDS. PRETTY STRONG UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE AREA TONIGHT. AHEAD OF THE DISTURBANCE...RAIN AND SNOW SHOWERS EARLY THIS EVENING WILL SWITCH OVER TO ALL SNOW LATE IN THE EVENING OR OVERNIGHT. A FEW SNOW SHOWERS COULD BE RATHER INTENSE...DROPPING VISIBILITIES UNDER A MILE. NOT LOOKING FOR MUCH ACCUMULATION...AS TEMPERATURES WILL BE IN THE 32-36 DEGREE RANGE...BUT RATHER UP TO AN INCH ON THE GRASSY SURFACES. PRECIPITATION WILL PEEL OUT LATE TONIGHT AND A BKN MVFR CLOUD DECK WILL REMAIN OVERHEAD THROUGH MID TO LATE MORNING. CLEARING THEREAFTER WILL LEAD TO A RETURN OF VFR CONDITIONS. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......KIECKBUSCH AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1225 PM CDT WED APR 24 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 338 AM CDT WED APR 24 2013 MAIN FORECAST CONCERNS THIS PACKAGE...PRECIP/THUNDER CHANCES LATE THIS AFTERNOON/THIS EVENING...TEMPERATURES. DATA ANALYSIS AT 06Z HAD A WEAK RIDGE OF HIGH PRESSURE FROM LK SUPERIOR SOUTHWEST TO KS/NEB. WV IMAGERY SHOWED ONE MID LEVEL TROUGH AXIS MOVING EAST ACROSS THE UPPER MIDWEST...WITH CLOUDS OVER THE SOUTHEAST HALF OF THE REGION SLOWLY CLEARING TO THE EAST/SOUTH. WHERE SKIES WERE CLEAR ACROSS MN/IA/WI...TEMPERATURES WERE QUICKLY SLIPPING BELOW FREEZING...WITH SOME TEENS AGAIN OVER FAR NORTHERN WI/NORTHEAST MN. WHAT A DIFFERENCE A YEAR MAKES...WITH THE NORTHERN HALF OF THE REGION STILL SNOW-COVERED ON APRIL 24TH. 24.00Z MODELS INITIALIZED WELL AND OFFER REASONABLY SIMILAR SOLUTIONS FOR TODAY AND TONIGHT. MODELS SHOWING SOME SUBTLE DIFFERENCES AS THE VIGOROUS SHORTWAVE PASSES THIS EVENING...THE MAIN ONE OF THESE LOOKS TO BE THE NAM BIAS OF NOT WANTING TO RAIN FROM A MID CLOUD DECK THRU A DRY SFC-850MB LAYER. DPROG/DT OF 500MB HGTS AT 24.00Z SHOWED THE MODEL RUNS OF 22.00Z AND 23.00Z VERIFIED VERY WELL ACROSS NOAM/EASTERN PAC WITH BETTER RUN-TO-RUN CONSISTENCY TO GFS/ECMWF. MODELS OFFERING A TIGHTENING CONSENSUS TODAY/TONIGHT AS THE SASKAT SHORTWAVE DROPS SOUTHEAST ACROSS THE REGION. OVERALL TREND IS SLIGHTLY WEAKER WITH THE SHORTWAVE AS IT CROSSES MN/WI TONIGHT. CHECK OF OBS VS. MODEL DATA AT 06Z SHOWED ALL TO BE QUITE GOOD WITH THE SFC MASS FIELDS OVER CENTRAL NOAM. PER WV IMAGERY ALL LOOKED GOOD WITH THE SHORTWAVE DETAILS OVER NOAM. WITH NO CLEAR MODEL FAVORITE AND THE TIGHT CONSENSUS...FAVORED THE MODEL/ENSEMBLE CONSENSUS THIS CYCLE. SHORT-TERM FCST CONFIDENCE IS GOOD THIS CYCLE. TODAY WILL START OUT COOL AND SUNNY/MOSTLY SUNNY AS A WEAK SFC-500MB RIDGE AXIS MOVES ACROSS THE AREA. THIS WILL BE SHORT LIVED AS MID LEVEL MOISTURE/CLOUDS AHEAD OF THE SHORTWAVE SPREADS QUICKLY SOUTHEAST ACROSS THE AREA THIS AFTERNOON. TIGHT/CONSISTENT MODEL SIGNAL FOR THE VIGOROUS SHORTWAVE DROPPING ACROSS SASKAT TO BE NEAR THE MN/DAKOTAS BORDER BY 00Z THEN SWING EAST/SOUTHEAST ACROSS MN THIS EVENING AND WI OVERNIGHT. MAIN SHOT OF MDT/STRONG 500-300MB PV ADVECTION WITH SOME 850-700MB FN CONVERGENCE/MOISTURE TRANSPORT/ THETA-E CONVERGENCE MOVES QUICKLY ACROSS THE FCST AREA LATE THIS AFTERNOON/EVENING. LIMITING FACTOR STILL LOOKS TO BE THE AMOUNT OF MOISTURE THIS WAVE HAS TO WORK WITH AS MODEL CONSENSUS ONLY INDICATES 1/4 TO 1/2 INCH OF PW LATE THIS AFTERNOON/EVENING AS THE WAVE PASSES. MOST OF THIS ABOVE 850MB...WITH DRY...INVERTED V SOUNDINGS BELOW 850MB. GIVEN THE STRENGTH OF THE MID LEVEL FORCING LIFT AND THE PV ADVECTION ALOFT...WILL CONTINUE THE 70-90 PERCENT -RA/-SHRA CHANCES AS THE SHORTWAVE PASSES LATE THIS AFTERNOON AND THIS EVENING. WITH ITS QUICK PASSAGE AND THE DRIER LOW LEVEL AIR... PRECIP WILL BE ON THE LIGHT SIDE. MODEL SOUNDINGS CONTINUE TO SHOW SOME NEUTRAL OR VERY WEAK MID LEVEL INSTABILITY AHEAD OF THE 850- 500MB TROUGH AND THE SHORTWAVE SO WILL CONTINUE AN ISOLATED TSRA MENTION IN THE 21-03Z TIME-FRAME. GIVEN LOW FREEZING LEVELS AND THE DRIER LOW LEVEL AIR...GUSTY WINDS AND SMALL HAIL WILL BE POSSIBLE WITH ANY TSRA AND EVEN ANY STRONGER SHRA. COLUMN COOLS ENOUGH AS THE TROUGH PASSES FOR PRECIP TO MIX WITH/CHANGE TO SNOW AROUND MIDNIGHT OVER THE NORTH PARTS OF THE FCST AREA. AGAIN... ANY -SN AMOUNTS WOULD BE QUITE LIGHT. EVEN WITH SOME SUNSHINE...HIGHS TO REMAIN COOL TODAY. USED A BLEND OF THE NUMERICAL TEMP GUIDANCE FOR HIGHS/LOWS TODAY/TONIGHT. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 338 AM CDT WED APR 24 2013 THU THRU FRI NIGHT ENTERS INTO A GENERALLY DRY AND WARMING PERIOD AS THE TROUGH EXITS QUICKLY EAST...HGTS RISE AND THE FLOW BECOMES NEARLY ZONAL ACROSS SOUTHERN CAN. TIGHTER MODEL CONSENSUS DEVELOPING FOR THU INTO SAT...WITH BETTER RUN-TO-RUN CONSISTENCY BY ECMWF AND OTHER MODELS TRENDING TOWARD IT IN THIS TIME PERIOD. AS LONGWAVE HGTS RISE OVER CENTRAL/WESTERN NOAM THU THRU FRI NIGHT... ONE WEAK SHORTWAVE SLIDES THRU THE FLOW AND ACROSS THE REGION LATE THU NIGHT/ FRI. RATHER CONSISTENT MODEL SIGNAL FOR MDT TO STRONG 925- 700MB WARM ADVECTION AND MOISTURE TRANSPORT/THETA-E CONVERGENCE TO SPREAD ACROSS THE FCST AREA DURING THIS TIME PERIOD. PW VALUES INCREASE INTO THE 1/2 TO 3/4 INCH RANGE...WITH SOUNDINGS SHOWING DEEPEST COLUMN SATURATION IN THE THE COOLER AIRMASS OVER THE NORTH/ EAST END OF THE FCST AREA. GIVEN THE PERSISTENT MODEL SIGNAL FOR SOME LIGHT QPF PRODUCTION...ADDED A SMALL -RA/-SN CHANCE TO THE NORTH END OF THE FCST AREA LATE THU NIGHT AND TO MAINLY THE NORTH/EAST END OF THE FCST AREA FRI AS THE AXIS OF STRONGEST MOISTURE TRANSPORT SLIDES SOUTHEAST ACROSS THE FCST AREA. STRONG LOW LEVEL WARM ADVECTION THU NIGHT/FRI AND MDT SOUTH TO SOUTHWEST WIND FLOW FINALLY SENDS TEMPERATURES TO NEAR NORMAL FOR FRI/FRI NIGHT. MEDIUM RANGE MODEL RUNS OF 24.00Z IN GOOD AGREEMENT SAT/SUN FOR THE NEARLY ZONAL FLOW ACROSS ACROSS SOUTHERN CAN. FCST CONFIDENCE REMAINS GOOD THRU SAT/SUN. THE STORM TRACK SHIFTS ACROSS SOUTHERN CAN WITH LOWER LEVEL WARM ADVECTION AND SOUTH/ SOUTHWEST FLOW CONTINUING OVER THE NORTH-CENTRAL CONUS. WARMING CONTINUES OVER THE UPPER MIDWEST SAT/SUN WITH 925MB TEMPS IN THE +14 TO +18C RANGE BY SUN AFTERNOON. MODEL CONSENSUS HIGHS IN THE 60S SAT AND IN THE 70F TO 75F RANGE SUN LOOK WELL TRENDED AT THIS TIME. IMPROVING MODEL CONSENSUS SUN NIGHT/MON FOR A STRONGER SHORTWAVE AND LOW TO LIFT ACROSS SOUTH-CENTRAL CAN...WHICH DRAGS A WEAKENING COLD FRONT INTO THE UPPER MIDWEST LATER SUN NIGHT/MON. PW VALUES INCREASE AHEAD OF THIS FRONT WITH SOME WEAK TO MDT CAPE AHEAD OF THE FRONT AS WELL. WITH MEDIUM FCST CONFIDENCE...SMALL -SHRA/TSRA CHANCE SUN NIGHT/MON REASONABLE FOR NOW. WITH THE AREA LOOKING REMAIN AHEAD OF THE FRONT MON...CONSENSUS HIGHS IN THE 70-75F RANGE FOR MON LOOK GOOD. MODEL DIFFERENCES INCREASE FOR MON NIGHT/TUE AS LONGER WAVE TROUGHING MOVES EAST ACROSS THE NORTHERN CONUS. GFS FASTER...ECMWF SLOWER AND THESE DIFFERENCES HAVE ON HOW FAST THE NEXT STRONGER COLD FRONT PUSHES INTO THE UPPER MIDWEST. FCST CONFIDENCE BY TUE BELOW AVERAGE. SMALL SHRA/TSRA CHANCES MON NIGHT/TUE AND LOWS/HIGHS TRENDED TOWARD THE MODEL/ENSEMBLE CONSENSUS APPEAR WELL TRENDED UNTIL MODELS DEVELOP A TIGHTER CONSENSUS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1225 PM CDT WED APR 24 2013 TWO AREAS OF CONCERN FOR THIS TAF CYCLE. FIRST IS GUST POTENTIAL LATE THIS AFTERNOON AND EVENING AND THE SECOND IS THE POTENTIAL FOR STRATUS LATER TONIGHT. SHORTWAVE TROUGH WILL PUSH COLD FRONT ACROSS THE SITES THIS EVENING. BAND OF SHOWERS EXPECTED AHEAD OF THIS FEATURE TO AFFECT THE KRST TAF SITES AROUND 00Z-01Z AND KLSE IN THE 02Z-03Z TIME FRAME. EXPECT CEILINGS TO LOWER LATE THIS AFTERNOON AND INTO THE EVENING...BUT WITH THE DRY LOW LEVELS WILL REMAIN IN THE VFR CATEGORY. RATHER STEEP LOW LEVEL LAPSE RATES WITH THE 24.15Z RAP SOUNDING SHOWING AN INVERTED V-SOUNDING FAVORABLE FOR MIXING HIGHER GUSTS TO THE SURFACE...WITH SOME ENHANCEMENT WITH THE STRONGER SHOWERS/ISOLATED THUNDERSTORMS. THE 24.15Z ARXLAPS AND 24.15Z HRRR BOTH SHOWING GUST POTENTIAL BETWEEN 25 AND 35 KNOTS IN THE SHOWERS...BUT THESE WOULD BE ISOLATED AT BEST AND WILL NOT INCLUDE THE HIGHER GUSTS IN THE TAFS. NEXT CONCERN IS POST FRONTAL STRATUS. NOT MUCH SHOWING UP RIGHT NOW OVER THE DAKOTAS AND LATEST GUIDANCE HAVE BACKED OFF ON THE LOWER CEILING POTENTIAL...ALTHOUGH 24.12Z NAM AND 24.15Z RAP SOUNDINGS SHOWING SOME MOISTURE AROUND 925 MPH. WILL KEEP MENTION OF JUST A SCATTERED DECK BETWEEN 015-025K FEET AT THIS TIME. OTHERWISE...SKIES SHOULD WILL BECOME CLEAR AFTER 12Z THURSDAY. && .HYDROLOGY...WARMING TEMPERATURES THIS WEEKEND ISSUED AT 338 AM CDT WED APR 23 2013 HIGHS IN THE 60S AND 70S AND LOWS IN THE 40S FOR FRIDAY THROUGH MONDAY WILL RESULT IN A MUCH INCREASED SNOW MELT RATE AND RUNOFF ACROSS CENTRAL MN INTO NORTHERN WI...UPSTREAM OF THE FCST AREA. ALL OF THIS INCREASED WATER FLOW WILL CREATE DECENT RISES IN CHIPPEWA...ST CROIX AND MISSISSIPPI RIVER BASINS AND THIS WILL FLOW DOWN INTO THE LOCAL MISSISSIPPI RIVER AREA BY EARLY MAY. RIVER FORECASTS AND STATEMENTS WILL ADDRESS THE MISSISSIPPI RIVER RISES AS DETAILS OF THE FINAL MELT AND INFLOWS TO THE TRIBUTARY RIVERS BECOME CLEARER THIS WEEKEND AND EARLY NEXT WEEK. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...RRS LONG TERM....RRS AVIATION...RABERDING HYDROLOGY....ZT/RRS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1051 PM MDT THU APR 25 2013 .UPDATE... ISSUED AT 701 PM MDT THU APR 25 2013 HAVE ALLOWED THE RED FLAG WARNING TO EXPIRE DUE TO INCREASING RH AND DECREASING WINDS. INCREASED PRECIP. CHANCES OVERNIGHT FOR THE SOUTHEAST PARTS OF THE AREA. MODELS AGREE THE BEST MOISTURE AND LIFT WILL BE OVER THOSE LOCATIONS DURING THE OVERNIGHT HOURS. OTHERWISE CURRENT FORECAST LOOKS TO BE IN VERY GOOD SHAPE. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 230 PM MDT THU APR 25 2013 EARLY AFTERNOON WV IMAGERY AND RUC ANALYSIS SHOW CLOSED LOW H5/H7 LOW OVER ARIZONA...WITH ENERGY AHEAD OF THIS FEATURE SPREADING NORTH INTO WESTERN KS/EASTERN COLORADO. AT THE SURFACE A STRONG SURFACE GRADIENT AS DEVELOPED IN RESPONSE TO SURFACE LOW DEEPENING OVER SOUTH CENTRAL COLORADO. WINDS GUSTS HAVE BEEN REPORTED THIS AFTERNOON IN THE 45-50 MPH RANGE...AND RH VALUES HAVE DROPPED TO 15-17 PERCENT OVER EASTERN PARTS OF THE CWA. CLOUD COVER COULD EVENTUALLY LIMIT MIXING...HOWEVER WITH PEAK HEATING UNDERWAY I AM COMFORTABLE KEEPING WIND ADVISORY AND RED FLAG WARNING IN PLACE WITH AFTERNOON UPDATE. CLOSED LOW OVER DESERT SW WILL EJECT OVER WESTERN KS TONIGHT INTO EASTERN KS FRIDAY. WHILE H5 CENTER BECOMES MORE OF AN OPEN WAVE...GUIDANCE IS INDICATING H7 CENTER REMAINING CLOSED AS IT PASSES OVER KS. MODELS SHOW MID LEVEL FRONTOGENETICAL FORCING OVERSPREADING OUR CWA THIS EVENING WITH POSSIBLE BAND FORMATION LATE TONIGHT ON NW SIDE OF H7 LOW...POSSIBLY RESULTING IN BETTER RAIN COVERAGE AND HIGHER RAIN TOTALS. THERE IS MINIMAL MU CAPE GENERALLY LESS THAN 100 J/KG...HOWEVER GFS/NAM BOTH SHOW NEGATIVE THETA E LAPSE RATES IN H8-H7 LAYER ASSOCIATED WITH MAIN AREA OF SHOWERS SO I COULDNT RULE OUT A FEW WEAK THUNDERSTORMS WITH THIS ACTIVITY. HAVE KEPT 50 POPS IN THE SOUTHEAST WHERE BETTER FORCING IS ADVERTISED...WITH RAIN COMING TO AN END FOR MOSTLY LOCATIONS FRIDAY MORNING. I KEPT SLIGHT CHANCE POPS LINGERING IN THE EASTERN PART OF CWA TO ACCOUNT FOR POSSIBLE RAIN BAND LINGERING OVER NORTH CENTRAL KS. THERE WILL BE A WEAK COLD FRONT PASSING THROUGH THE CWA BY FRIDAY MORNING...HOWEVER WITH CLEARING SKIES AND WAA IN THE AFTERNOON I STILL EXPECT HIGHS FRIDAY TO REACH UPPER 60S/NEAR 70 IN THE WEST (BASED ON MIXING THE LAST FEW DAYS). WARMING COULD BE LIMITED IN THE EAST DUE TO CLOUDS/PRECIP POSSIBLY LINGERING. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 230 PM MDT THU APR 25 2013 FRIDAY NIGHT-SUNDAY...DRY WEATHER EXPECTED. WILL NEED TO WATCH THE FAR EASTERN PORTIONS OF THE AREA FOR THUNDERSTORMS SATURDAY AFTERNOON AS A SFC TROUGH MOVES THROUGH. THERE IS SOME WEAK CONVERGENCE AND INSTABILITY ALONG THE WIND SHIFT WITH THIS FEATURE...QUESTION RIGHT NOW IS HOW MUCH MOISTURE WILL BE AVAILABLE. ANY THREAT FOR PRECIP SATURDAY AFTERNOON QUICKLY DECREASES SATURDAY NIGHT AS THE SFC TROUGH MOVES EAST AND OUT OF THE AREA. FOR SUNDAY GENERALLY SUNNY...MAY SEE SOME CIRRUS MOVE DOWN FROM THE NORTH. LOWS FRIDAY NIGHT MID 30S TO LOW 40S WITH UPPER 30S TO MID 40S SATURDAY NIGHT. HIGHS SATURDAY IN THE 70S WITH MID 70S (WEST) TO MID 80S (EAST) SUNDAY. SUNDAY NIGHT-MONDAY...COLD FRONT BRIEFLY PUSHES SOUTHWEST ACROSS THE AREA SUNDAY NIGHT BEFORE RETREATING OUT OF THE AREA. NEAR OR SLIGHTLY COOLER READINGS COMPARED TO SUNDAY EXPECTED ACROSS THE NORTHEAST AND EAST WHERE PROXIMITY TO DEPARTING HIGH WILL BE FELT MOST. TO THE WEST SIMILAR TO SLIGHTLY WARMER READINGS COMPARED TO SUNDAY. LOWS MID 40S TO LOW 50S (WEST TO EAST) WITH HIGHS 75 TO 80 MONDAY. MONDAY NIGHT-TUESDAY NIGHT...SFC TROUGH ACROSS THE AREA MONDAY NIGHT WITH COLD FRONT MOVING THROUGH FROM THE NORTH TUESDAY. BREEZY NORTH TO NORTHEAST WINDS TUESDAY NIGHT BEHIND THE FRONT. LOWS MONDAY NIGHT MID 40S TO MID 50S (WEST TO EAST) WITH MID 30S TO MID 40S (WEST TO EAST) TUESDAY NIGHT. HIGHS TUESDAY LOW 70S TO AROUND 80 (NORTH TO SOUTH). SHOWERS AND A FEW THUNDERSTORMS POSSIBLE ACROSS THE EAST TUESDAY AFTERNOON AHEAD OF THE FRONT. POST FRONTAL STABLE AIR MOVES IN TUESDAY NIGHT. REMOVED MENTION OF THUNDERSTORMS BUT STILL HAVE A CHANCE OF LIGHT RAIN. WEDNESDAY-WEDNESDAY NIGHT...BREEZY NORTH WINDS TO CONTINUE ACROSS THE EASTERN HALF OF THE AREA THROUGH THE DAY. SFC HIGH REMAINS OVER THE AREA WEDNESDAY NIGHT ALLOWING FOR NEAR TO SLIGHTLY BELOW NORMAL LOW TEMPERATURES. HIGHS IN THE MID TO UPPER 50S WITH LOWS MID TO UPPER 30S. LOW CHANCES FOR SOME LIGHT RAIN OR RAIN SHOWERS DURING THE DAY DECREASING DURING THE NIGHT. THURSDAY...WARMER TEMPERATURES EXPECTED TO RETURN TO THE AREA AS UPPER RIDGING SLOWLY MOVES IN FROM THE WEST. HIGHS MID 50S TO LOW 60S. CONTINUED LOW CHANCE FOR SOME LIGHT RAIN ACROSS THE AREA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1043 PM MDT THU APR 25 2013 VFR CONDITIONS ARE FORECAST FOR THE 6Z TAFS. SHOWER ACTIVITY FOR THE NIGHT SHOULD REMAIN EAST OF KGLD AND WELL SOUTH OF KMCK. WINDS HAVE TURNED TO THE SOUTHEAST AT KGLD DUE TO OUTFLOW FROM THE SHOWERS. THE WINDS SHOULD TURN BACK TO THE SOUTH A COUPLE HOURS AFTER 6Z IF NOT SOONER AS THE SHOWERS MOVE FURTHER AWAY. OVERNIGHT WINDS WILL BECOME LIGHT AHEAD OF A WEAK COLD FRONT THAT MOVES INTO THE AREA LATE TONIGHT/EARLY FRIDAY MORNING. THE NORTH WINDS WILL BEGIN TO BECOME GUSTY BY LATE MORNING/EARLY AFTERNOON THEN CALM IN THE EARLY EVENING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JTL SHORT TERM...DR LONG TERM...99 AVIATION...JTL
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
415 AM CDT FRI APR 26 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 356 AM CDT FRI APR 26 2013 SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER EASTERN MN AND WEST CENTRAL WI EARLY THIS MORNING WILL PUSH EAST OF THE FA BY 15Z AS A MID LEVEL SHORT WAVE PASSES BY. A WARM FRONT ACROSS THE MN RIVER VALLEY WILL ALSO SLIDE NORTHEAST THIS MORNING WITH THE WARMEST DAY SO FAR THIS YEAR OCCURRING. KEPT HIGHS ABOVE GUIDANCE WITH A FAVORABLE LOW LEVEL THERMAL/WIND PATTERN. HIGHS ON THURSDAY TO OUR WEST WERE ABOUT 20 DEGREES ABOVE THE H85 TEMPERATURE. THIS TREND TODAY WOULD PUSH HIGHS INTO THE UPPER 60S FROM THE TWIN CITIES ON SOUTHWEST WITH LOWER TO MIDDLE 60S ON NORTH AND EAST. ONLY THE FAR NORTHWEST REACHES WILL LIKELY BE HELD IN THE UPPER 50S DUE THE SNOW COVER. THIS WILL BE THE FIRST 60 DEGREE READING FOR MSP THIS YEAR... COMING JUST THREE DAYS SHORT OF TYING THE LATEST 60 DEGREE READING... SET APRIL 29 1874. THE LATEST 60 DEGREE READING BEHIND 1874 IS APRIL 26 1904 AND AGAIN IN 1947. HIGHS IN THE 60S ARE ALSO FORECAST FOR KSTC AND KEAU. THE LATEST 60 DEGREE READING FOR THE KSTC AREA IS APRIL 26 1947 AND 1965. FOR KEAU... THE LATEST 60 DEGREE READING IS APRIL 26 1951. HENCE...THESE WILL TIE FOR THE LATEST 60 DEGREE READING. THERE WILL BE A TROUGH OF SURFACE LOW PRESSURE PROGRESS ACROSS THE CWA DURING THE AFTERNOON AND EVENING HOURS. THERE IS A SMALL CHANCE THAT A FEW SHOWERS COULD DEVELOP FROM LADYSMITH TO ALBERT LEA TOWARDS EVENING. THE CONSENSUS BETWEEN THE VARIOUS WRF MODELS WAS FOR SHOWERS TO BE EAST AND SOUTH OF THE CWA. ONLY THE MPXWRF AND HOPWRF MEMBER 1 HAD A FEW SHOWERS LATE THIS AFTERNOON IN THE AFOREMENTIONED AREA OF OUR CWA. THEREFORE... LEFT THE MENTION FOR SHOWERS OUT. IT ALSO APPEARED THAT THE MODELS WERE FORECASTING DEW POINT TOO HIGH THIS AFTERNOON. THEREFORE... STAYED ON THE CONSERVATIVE SIDE WITH UPPER 30S TO LOWER 40S INSTEAD OF MIDDLE TO UPPER 40S. THE LOWER DEW POINTS SEEM MORE REALISTIC WITH MIXING AND A DRY ADIABATIC LAPSE RATE FORECAST TO 800 MB THIS AFTERNOON. THIS RESULTS IN AFTERNOON MINIMUM HUMIDITY NEAR 35 PERCENT OUTSIDE OF SNOW COVERED AREAS. FINALLY... ADDED AREAS OF FOG TO CENTRAL MN AND WEST CENTRAL WI FOR LATE TONIGHT. WITH THE MELTING TODAY IN THESE AREAS ALONG WITH HIGH PRESSURE AND LIGHT WINDS SETTLING IN TONIGHT... BUFKIT NAM HYDROLAPSE RATES SHOW A NICE INCREASE DURING THE LATE NIGHT HOURS. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 356 AM CDT FRI APR 26 2013 DRY AND WARM CONDITIONS WILL PREVAIL ON SATURDAY AS SOUTHERLY FLOW INCREASES NOTICEABLY AHEAD OF FIRST WEAK COOL FRONT MARCHING THROUGH MUCH OF MONTANA. FRONTAL BOUNDARY WILL TREK THROUGH MUCH OF FA BY EARLY MONDAY MORNING...STALL FOR A SHORT PERIOD OF TIME ...AND THEN MIGRATE BACK NORTH INTO THE SOUTHERN MN AND WEST CENTRAL WI PRIOR TO TUE/03Z. RIGHT REAR QUAD OF 75KT JET CORE PUSHING INTO CENTRAL MN AND HEALTHY THETA E ADVECTION WILL BRING ISOLATED STRONG THUNDERSTORMS FROM SOUTH CENTRAL MN TO WEST CENTRAL WI ON SUNDAY EVENING...WITH BEST CHANCES AT THIS JUNCTURE OVER SOUTH CENTRAL MN. 993MB SURFACE CYCLONE ON GFS40 HAS MEANDERED FURTHER SOUTH OVER PAST 2 RUNS...BRINGING IT OVER NORTHERN AND CENTRAL MN BY LATE TUESDAY MORNING...WITH STRONG COLD FRONT STRETCHING SOUTH INTO SW MN AND NE SODAK. SECOND ROUND OF STRONG THUNDERSTORMS WILL MATERIALIZE TUE/12Z-18Z...AS MUCH MORE POTENT 110KT JET MAXIS BECOMES VISIBLE OVER NW MN AND EASTERN NODAK. LUCKILY SIGNIFICANT INCREASE OF LOW LEVEL JET DOES NOT OCCUR UNTIL LATE AFTN INTO THE EVEN...WHERE SOUTH TO SW 850MB WINDS SHOULD BE IN THE 25 TO 35KT CATEGORY. PASSAGE OF SECOND FRONTAL BOUNDARY THROUGH WESTERN WI WILL OCCUR BY TUE NIGHT. 50H TROF WILL DIG OVER CWA ON WEDNESDAY AND THURSDAY AS MID LEVEL CUT OFF LOW PRESSURE DEVELOPS OVER NORTHERN WI BY THU/18Z. 850MB TEMPS...WHICH WILL SPIKE INTO THE 10 TO 15 DEGREE VARIANCE BY SUNDAY AFTN...WILL COLLAPSE BACK INTO THE NEGATIVE 8 TO 12C RANGE BY THU MORNING. GFS40 HAS HANDLED TONIGHT`S CURRENT WEAK CONVECTIVE SCENARIO WELL. EUROPEAN...WHICH HAD BEEN AN OUTLIER CONCERNING THE DEVELOPMENT OF A MID LEVEL CUT OFF LOW THIS FAR NORTH...IS NOW MORE IN TUNE WITH THE GFS. UNFORTUNATELY...BOTH INDICATE THE PRESENCE OF THIS FEATURE OVER THE WESTERN GREAT LAKES AND INTO MN THROUGH NEXT SATURDAY. THIS WILL KEEP US IN FAIRLY ROBUST CAA AND WELL BELOW NORMAL TEMPS WED THROUGH AT LEAST NEXT SATURDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1135 PM CDT THU APR 25 2013 WARM FRONT SITTING FROM CENTRAL SODAK INTO CENTRAL IA THIS EVENING. STRONG WARM ADVECTION NORTH OF THE BOUNDARY HAS RESULTED IN RAPID EXPANSION OF MID LEVEL CLOUDS...WITH RADAR RETURNS INCREASING. HOWEVER...WITH VERY DRY LOW LEVELS IN PLACE...MOST OF THIS RAIN IS NOT REACHING THE GROUND WITH VFR CONDS EXPECTED TO PREDOMINATE AS A RESULT. HRRR ALONG WITH THE HOPWRF CONTINUE TO SHOW ENOUGH MOISTENING OCCURRING OVER WRN WI TO ALLOW FOR SOME LIGHT RAIN TO REACH THE SFC. ONLY CHANGE FROM 00Z TAFS WAS TO NARROW TEMPO SHRA WINDOW AT RNH/EAU. DURING THE DAY FRIDAY...A WEAK SFC TROUGH WILL WORK INTO THE AREA...WHICH WILL RESULT IN A DECREASE OF THE WINDS DURING THE DAY AS THEY VEER AROUND TO THE W-NW. KMSP...VFR CONDITIONS EXPECTED THROUGHOUT AS DRY LOW LEVELS KEEP RAIN FROM REACHING THE SFC. MINIMAL COLD ADVECTION EXPECTED BEHIND THE MORNING WIND SHIFT...WHICH WILL KEEP ANY LOW CLOUDS FROM FORMING IN ITS WAKE. AS LLJ MOVES OVERHEAD TONIGHT...MAY HAVE SOME WIND SHEAR...BUT WITH MINIMAL WIND SHIFT HAVE CONTINUED TO NOT MENTION IT. /OUTLOOK FOR KMSP/ SAT...VFR. SSW WINDS 10 KTS. SUN...VFR. SSW WINDS 15-20 KTS. MON...MVFR OR LOWER POSSIBLE WITH CHANE -SHRA/-TSRA. WIND SE 5-10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...RAH LONG TERM...AJZ AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1136 PM CDT THU APR 25 2013 .UPDATE... 06Z AVIATION DISCUSSION ADDED BELOW. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 344 PM CDT THU APR 25 2013 WE WILL TURN THE CORNER IN TERMS OF TEMPERATURES OVER THE NEXT 24 HOURS AND REMAIN WARM THROUGH EARLY NEXT WEEK. A WARM FRONT CURRENTLY IN THE DAKOTAS WILL MOVE ACROSS MN AND INTO WI LATE TONIGHT. THIS FRONT WILL PRIMARILY COME THROUGH DRY IN MN...BUT THERE IS A CHANCE FOR LIGHT RAIN IN WESTERN WI BETWEEN 1 AM AND 7 AM. THE ISENTROPIC LIFT ALREADY BEGINS TO INCREASE BETWEEN 03-06Z IN WESTERN MN...BUT SATURATION IN THE LOWEST LEVELS OF THE ATMOSPHERE ISN`T A SURE THING GIVEN DRIER IN PLACE BELOW 10000 FT. THE FORECAST SOUNDINGS LATE TONIGHT LOOK MORE SUPPORTIVE OF A 2-4 HOUR WINDOW OF LIGHT RAIN IN WESTERN WI. THIS IS ALSO EVIDENT ON THE ISENTROPIC SURFACES OF THE NAM AND TO SOME DEGREE GFS. THE CONDENSATION PRESSURE DEFICITS ON THE 290K SURFACE DOESNT SUGGEST SATURATION UNTIL YOU GET TO CENTRAL WI. THIS WOULD OVERLAP WITH THE 850-700 MB...THAT IS FAIRLY DRY. THE 295K DOES SATURATE IN FAR EASTERN MN AND WESTERN WI...WHICH IS CLOSER TO THE 700-600 MB LAYER. AT ANY RATE...DESPITE OF THE OVERLAP IN QPF OFF THE GFS/NAM/EC IT WAS HARD TO GO MUCH HIGHER IN THE POP FORECAST THAN 50-60%. OTHERWISE...THE ONLY OTHER CHALLENGE IN THE SHORT TERM WAS TO DETERMINE HOW WARM WE GET BEHIND THE WARM FRONT TOMORROW. THERE IS STILL A FEW AREAS WITH SNOW ON THE GROUND...SO TRIED TO ADJUST TEMPS DOWN A FEW DEGREES IN THESE AREAS. HOWEVER...GIVEN THE WARM AIR ADVECTION AND LATE APRIL SUN IT`S HARD TO IMAGINE MUCH OF THE AREA NOT GETTING WELL INTO THE 60S. 2M TEMPS OFF THE GFS AT 18Z EVEN MAKE IT INTO THE LOWER 60S...AND IF THE KNOWN COOL GFS IS FORECASTING THOSE TEMPS...THAN MID 60S ARE USUALLY A LOCK WITH SUNSHINE. IN SOUTHERN MN...THE 925-850MB TEMPS JUMP 10-12 DEGREES C OVER THE NEXT 18 HOURS WITH THE WARM FRONT. THE GROUND IS STILL MOIST...SO 70S MAY BE HARD TO COME BY TOMORROW BUT IT WILL NO DOUBT BE THE WARMEST DAY OF THE YEAR SO FAR BY ABOUT 10-15 DEGREES. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 344 PM CDT THU APR 25 2013 THE HIGHLY ADVERTISED WARM-UP IS STILL ON TRACK TO CONTINUE INTO THE WEEKEND. BY SATURDAY AFTERNOON...H85 TEMPS INCREASE TO BETWEEN +7C AND +10C...WITH ADDITIONAL MODERATION INTO THE LOWER TEENS ON SUNDAY PRIOR TO THE FRONTAL PASSAGE. EXPECT UPPER 60S TO LOWER 70S TO BE COMMON SATURDAY AS A FEW AREAS WORK TO GET RID OF THE REMAINING SNOWPACK. SUNDAY SHOULD BE THE WARMEST DAY OF THE WEEKEND AS THE THERMAL RIDGE NOSES INTO THE AREA AHEAD OF THE FRONT...AND DEEP MIXING YIELDS HIGHS IN THE LOW/MID 70S. COULD SEE A FEW SHOWERS AND THUNDERSTORMS DEVELOP ALONG THE FRONT ON SUNDAY AFTERNOON...ALTHOUGH HIGHER PROBABILITIES WILL ARRIVE ON SUNDAY EVENING/NIGHT AS MORE MOISTURE ADVECTS INTO THE AREA. THE FRONT STALLS JUST ALONG THE SOUTHEAST EDGE OF THE FORECAST AREA ON MONDAY...WITH THE ATTENDANT WEAKLY UNSTABLE AIRMASS WARRANTING INCLUSION OF 20-30 POPS FOR SHOWERS AND ISOLATED THUNDERSTORMS. MUCH HIGHER PRECIP CHANCES ARRIVE ON TUESDAY AND WEDNESDAY...AS A WARM FRONT LIFTS ACROSS THE AREA AND IS FOLLOWED BY THE PASSAGE OF A STRONG COLD FRONT. DECENT MOISTURE/WARM AIR ADVECTION ARE PROGGED BY THE MODELS...AS WELL AS STRONG 700-600MB FRONTOGENESIS WITH THE MID LEVEL TROUGH. HAVE RETAINED HIGH CHANCE POPS /ESPECIALLY FROM SOUTH CENTRAL MN INTO WEST CENTRAL WI/. WITH THE TROUGH OVERHEAD...COOLER TEMPS WILL RESULT. HIGHS ON WEDNESDAY AND THURSDAY WILL LIKELY TOP OUT IN THE 50S...WHILE LOWS RETURN TO THE 30S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1135 PM CDT THU APR 25 2013 WARM FRONT SITTING FROM CENTRAL SODAK INTO CENTRAL IA THIS EVENING. STRONG WARM ADVECTION NORTH OF THE BOUNDARY HAS RESULTED IN RAPID EXPANSION OF MID LEVEL CLOUDS...WITH RADAR RETURNS INCREASING. HOWEVER...WITH VERY DRY LOW LEVELS IN PLACE...MOST OF THIS RAIN IS NOT REACHING THE GROUND WITH VFR CONDS EXPECTED TO PREDOMINATE AS A RESULT. HRRR ALONG WITH THE HOPWRF CONTINUE TO SHOW ENOUGH MOISTENING OCCURRING OVER WRN WI TO ALLOW FOR SOME LIGHT RAIN TO REACH THE SFC. ONLY CHANGE FROM 00Z TAFS WAS TO NARROW TEMPO SHRA WINDOW AT RNH/EAU. DURING THE DAY FRIDAY...A WEAK SFC TROUGH WILL WORK INTO THE AREA...WHICH WILL RESULT IN A DECREASE OF THE WINDS DURING THE DAY AS THEY VEER AROUND TO THE W-NW. KMSP...VFR CONDITIONS EXPECTED THROUGHOUT AS DRY LOW LEVELS KEEP RAIN FROM REACHING THE SFC. MINIMAL COLD ADVECTION EXPECTED BEHIND THE MORNING WIND SHIFT...WHICH WILL KEEP ANY LOW CLOUDS FROM FORMING IN ITS WAKE. AS LLJ MOVES OVERHEAD TONIGHT...MAY HAVE SOME WIND SHEAR...BUT WITH MINIMAL WIND SHIFT HAVE CONTINUED TO NOT MENTION IT. /OUTLOOK FOR KMSP/ SAT...VFR. SSW WINDS 10 KTS. SUN...VFR. SSW WINDS 15-20 KTS. MON...MVFR OR LOWER POSSIBLE WITH CHANE -SHRA/-TSRA. WIND SE 5-10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...CLF LONG TERM...LS AVIATION...MPG
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
353 AM CDT FRI APR 26 2013 .SHORT TERM...(THROUGH LATE THIS AFTERNOON) ISSUED AT 353 AM CDT FRI APR 26 2013 THE PRIMARY FCST ISSUE FOR TODAY IS PCPN COVERAGE. EARLY MORNING WATER VAPOR IMAGERY AND RUC 1.5 PVU ANALYSES DEPICTED A COMPACT VORT MAX OVER MN AS WELL AS A SHORTWAVE NEAR THE FOUR CORNERS REGION. A BROAD AREA OF SHRA/TSRA HAS DEVELOPED ACROSS PARTS OF KS/OK/MO/AR IN RESPONSE TO A COMBINATION OF H9 FRONTOGENESIS AND H85-H7 MOISTURE CONVERGENCE FM THE LLJ AHEAD OF THE FOUR CORNERS SHORTWAVE. THIS 40-50KT SWLY LLJ /PER AREA VWP AND PROFILER OBS/ WAS TRANSPORTING MOISTURE INTO THE AREA AND LEADING TO AN INCREASE IN PCPN COVERAGE. ALTHOUGH MODELS GENERALLY SHOW A DECREASE IN THE LLJ THROUGH MID MORNING ACROSS MO/IL...THEY ALSO SHOW PERSISTENT AREAS OF ISENTROPIC ASCENT ALONG THE 295-305K SFCS /ESPECIALLY ACROSS THE SWRN CWA/ ALONG WITH AREAS OF INCREASED FRONTOGENESIS ALOFT. ALTHOUGH THE BEST FORCING FOR LARGE SCALE ASCENT WILL NOT ARRIVE UNTIL LATER TONIGHT AND THE LOW LEVEL AIR MASS WILL INITIALLY BE SOMEWHAT DRY...THE AFOREMENTIONED LIFTING MECHANISMS APPEAR SUFFICIENT TO CONTINUE POPS FOR SCT-INTERMITTENT SHRA TODAY. 42 .LONG TERM...(TONIGHT THROUGH THURSDAY) ISSUED AT 353 AM CDT FRI APR 26 2013 (TONIGHT - SATURDAY) A LARGELY NEUTRAL UPPER LEVEL FLOW WILL EXIST THRU SATURDAY...BUT THIS PERIOD WILL BE MOST MARKED BY A STRONG SHORTWAVE SLOWLY PASSING THRU. THE PROGRESSION OF THIS SYSTEM THRU THE BI-STATE WILL BE SLOW...WITH IT NOT EXPECTED TO PULL AWAY UNTIL LATE SATURDAY NIGHT. UNTIL SUNDAY...LOOK FOR CLOUDY SKIES WITH HI RAIN PROBS...EVEN THOUGH SOME AREAS MAY ONLY RECEIVE A FEW HUNDREDTHS WITH EXPECTED NATURE OF PCPN FOR MUCH OF THIS EVENT TO BE SHOWERY. MAIN AREAS TO KEY ON FOR RAIN TONIGHT WILL BE WHAT SHOULD BE A PERSISTENTLY STRONG REGION OF WAA AND H850-700 FRONTOGENESIS OVER SERN MO AND FAR SRN IL WHICH WILL REPRESENT THE BEST CHANCES FOR MEASURABLE...BUT A MORE BROADSCALE REGION OF MID LEVEL LIFT SHOULD ALSO WORK IN FOR THE REMAINDER OF THE AREA...ESPECIALLY W OF THE MS RIVER FOR ADDITIONAL LIGHT RAIN AMOUNTS. ON SATURDAY THE MEAT OF THE SYSTEM MOVES THRU WITH GENERALLY WEAK YET DEEP LIFT THRU A MOIST COLUMN...AND BUMPED POPS TO LIKELY FOR WIDESPREAD LIGHT RAINFALL AMOUNTS. THIS FINALLY BEGINS TO EXIT SATURDAY NIGHT WITH MOISTURE SLOWLY SCOURING OUT ALTHOUGH COULD SEE SHRA SIMPLY BE REPLACED BY DRIZZLE EARLY SUNDAY MORNING WITH LO CLOUDS BEING THE MOST STUBBORN OF ALL TO LEAVE. THE WARMER MAV MOS IS PREFERRED FOR MINS TONIGHT...WHILE WENT WITH THE COOLER MET MOS FOR MAXES SATURDAY TO PROMOTE A LO DIURNAL SWING WITH WHAT SHOULD BE THICK AND LO CLOUD COVER. AGAIN PREFERRED WARMER MAV MOS FOR SATURDAY NIGHT MINS. (SUNDAY - TUESDAY) UPPER LEVEL LONGWAVE RIDGE WILL BUILD OVER ERN NOAM WHILE A TROF DIGS IN THE W...RESULTING IN A WARM AND DRY PERIOD...WITH TEMPS PUSHING ABOVE AVERAGE FOR A COUPLE OF DAYS AT LEAST. WHILE DID UNDERCUT MOS MAX TEMPS ON SUNDAY DUE TO WHAT SHOULD BE STUBBORN LO CLOUD HANGING AROUND AND FINALLY LEAVING...MONDAY AND TUESDAY ARE EXPECTED TO FEATURE PLENTY OF SUNSHINE AND A DECENT S FLOW WITH RISING H500 HEIGHTS OVERHEAD. FCST H850/H900 TEMPS...IF THEY PAN OUT...WILL RESULT IN 75-80F FOR MONDAY AND AROUND 78-82F FOR TUESDAY. BUILDING RIDGE WILL EFFECTIVELY DEFLECT ANY SYSTEMS TO OUR N AND SHOULD KEEP OUR REGION DRY. (WEDNESDAY - THURSDAY) ALL OF THIS IS SHORT-LIVED...WITH THE UPPER LEVEL ERN NOAM RIDGE TO BREAKDOWN EITHER WEDNESDAY OR THURSDAY DEPENDING ON THE MODEL AND WILL BE ACCOMPANIED BY A STOUT CDFNT BACKED BY A STRONG CANADIAN AIRMASS. THE ECMWF PREFERS A SLOWER TIMING ON THURS WHILE THE GFS FAVORS WEDNESDAY. HAVE STRETCHED POPS FOR WED-THU TO COVER TIMING DIFFS WITH FRONT AND DID NOT HIT THE COLD AIR AS MUCH ON THURSDAY FOR THE SAME REASONS. TES && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1127 PM CDT THU APR 25 2013 HIGH-LEVEL CLOUD DECK HAS OVERSPREAD MID-MISSISSIPPI VALLEY AHEAD OF SYSTEM EJECTING OUT OF THE DESERT SOUTHWEST. AREA OF SHOWERS HAS DEVELOPED OVER CENTRAL KANSAS AND THIS AREA SHOULD SLOWLY PUSH EASTWARD OVERNIGHT WITHIN ZONAL FLOW. STILL THINKING THIS SHOULD TRANSLATE ACROSS THE INTERSTATE CORRIDOR IN MISSOURI THROUGH LATE MORNING TOMORROW. STILL SOME UNCERTAINTY ON HOW WELL THIS HOLDS TOGETHER WITH EASTWARD EXTENT AS LOW-LEVEL ENVIRONMENT WILL BE DRIER IN CLOSER PROXIMITY SURFACE RIDGE AXIS...ESPECIALLY GIVEN FARILY WEAK UPPER-AIR FORCING. NWP GUIDANCE DIVERGES FURTHER LATE FRIDAY AND FRIDAY NIGHT WITH NAM FURTHER NORTH WITH AREA OF PRECIPITATION THAN GFS. DIFFERENCES ARE DUE PRIMARILY TO PLACEMENT OF LOW-LEVEL JET/MOISTURE CONVERGENCE...NAM BEING FURTHER NORTH/COLLOCATED WITH UPPER-AIR FORCING AND GFS CLSOER TO MISSOURI/ARKANSAS BORDER. WITH STRONG UPPER-AIR FORCING FOR ASCENT MOVING IN...LEANED TOWARD FURTHER NORTH PLACEMENT OF QPF AXIS YIELDING -SHRA AT KCOU AND METRO TAF SITES ALONG WITH MVFR CEILINGS/VISIBILITIES. AS FOR WINDS...THEY WILL REMAIN OUT OF THE SOUTH/SOUTHEAST THROUGH THE PERIOD WITH THE STRONGEST WINDS DURING THE DAY TOMORROW AS PRESSURE GRADIENT INCREASES. SPECIFICS FOR KSTL...HIGH-LEVEL CLOUD DECK HAS OVERSPREAD MID- MISSISSIPPI VALLEY AHEAD OF SYSTEM EJECTING OUT OF THE DESERT SOUTHWEST. AREA OF SHOWERS HAS DEVELOPED OVER CENTRAL KANSAS AND THIS AREA SHOULD SLOWLY PUSH EASTWARD OVERNIGHT WITHIN ZONAL FLOW. STILL THINKING THIS SHOULD TRANSLATE ACROSS THE INTERSTATE CORRIDOR IN MISSOURI THROUGH LATE MORNING TOMORROW. STILL SOME UNCERTAINTY ON HOW WELL THIS HOLDS TOGETHER WITH EASTWARD EXTENT AS LOW-LEVEL ENVIRONMENT WILL BE DRIER IN CLOSER PROXIMITY SURFACE RIDGE AXIS...ESPECIALLY GIVEN FARILY WEAK UPPER-AIR FORCING. NWP GUIDANCE DIVERGES FURTHER LATE FRIDAY AND FRIDAY NIGHT WITH NAM FURTHER NORTH WITH AREA OF PRECIPITATION THAN GFS. DIFFERENCES ARE DUE PRIMARILY TO PLACEMENT OF LOW-LEVEL JET/MOISTURE CONVERGENCE...NAM BEING FURTHER NORTH/COLLOCATED WITH UPPER-AIR FORCING AND GFS CLSOER TO MISSOURI/ARKANSAS BORDER. WITH STRONG UPPER-AIR FORCING FOR ASCENT MOVING IN...LEANED TOWARD FURTHER NORTH PLACEMENT OF QPF AXIS YIELDING -SHRA AT KSTL ALONG WITH MVFR CEILINGS/VISIBILITIES. AS FOR WINDS...THEY WILL REMAIN OUT OF THE SOUTH/SOUTHEAST THROUGH THE PERIOD WITH THE STRONGEST WINDS DURING THE DAY TOMORROW AS PRESSURE GRADIENT INCREASES. GOSSELIN && .LSX WATCHES/WARNINGS/ADVISORIES... MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
339 AM CDT FRI APR 26 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 337 AM CDT FRI APR 26 2013 A WEAK PACIFIC COLD FRONT WILL DROP THROUGH THE FCST AREA THIS MORNING. THE H850 MB THERMAL RIDGE SHOULD REDEVELOP SOMEWHAT THIS AFTERNOON. DEW POINTS IN THE 20S AND NEARLY FULL SUN SUPPORT MIXING TO 700 MB AND HIGHS AROUND 70. WINDS SFC TO 700 MB REMAIN MOSTLY NORTH AND WEAK AT 25 KTS OR LESS THROUGH TONIGHT WITH NEARLY NEUTRAL THERMAL ADVECTION. GIVEN THE DRY AIR...LOWS IN THE 30S TO NEAR 40 ARE FCST TONIGHT. A WEAK LOW LEVEL JET DEVELOPS TONIGHT ACROSS THE WEST LIMITING RADIATIONAL COOLING. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 337 AM CDT FRI APR 26 2013 WARM WEATHER IS EXPECTED THROUGH THE WEEKEND...WITH A COUPLE OF WEAK PACIFIC COLD FRONTAL PASSAGES. THESE WILL HAVE LITTLE AFFECT ON TEMPERATURES...AND HIGHS IN THE 70S TO NEAR 80 DEGREES ARE FORECASTED BOTH SATURDAY AND SUNDAY. MONDAY WILL CONTINUE TO BE WARM...WITH SOUTHERLY WINDS DEVELOPING IN RESPONSE TO DEVELOPING SFC LOW PRESSURE ACROSS WESTERN SOUTH DAKOTA. BY TUESDAY...A LONG WAVE TROUGH WILL BEGIN TO DIG SOUTH FROM CANADA INTO THE NORTHERN ROCKIES. THE 26/00Z RUN OF THE ECMWF LOOKS THE BEST FOR US IN REGARDS TO PRECIPITATION. IT STALLS A FRONT/SFC BOUNDARY TUESDAY ALONG THE NE/KS BORDER...WITH EASTERLY SFC WINDS ADVECTING SOME LOW LEVEL MOISTURE WESTWARD INTO SOUTHWEST NEBRASKA TO THE NORTH OF THE FRONT. TUESDAY NIGHT A STRONG SOUTHERLY LOW LEVEL JET DEVELOPS ACROSS KS...WHILE A NORTHERN PLAINS JET STREAK CROSSES THE DAKOTAS PLACING OUR AREA IN THE FAVORABLE RIGHT REAR QUADRANT. THE COMBINATION OF A STRONG LOW LEVEL JET AND FAVORABLE UPPER LEVEL JET DYNAMICS SHOULD SUPPORT AT LEAST SOME RISK OF ELEVATED CONVECTION NORTH OF THE SFC BOUNDARY ACROSS MUCH OF NEBRASKA. THE 26/00Z GFS INDICATES A SIMILAR SCENARIO...BUT STALLS THE FRONT FARTHER SOUTH. THIS WOULD KEEP THE BETTER PRECIPITATION CHANCES TO THE SOUTH AND EAST OF THE AREA. WILL CONTINUE TO MONITOR THE MODEL TRENDS REGARDING THE FRONTAL PLACEMENT AND SUBSEQUENT PRECIPITATION CHANCES. FOR NOW WILL CAP POPS AT 40 PERCENT UNTIL MODELS COME INTO BETTER AGREEMENT. BY MID TO LATE WEEK...THE 26/00Z RUN OF THE ECMWF HAS FINALLY LET GO OF IT/S SOUTHWARD DEVELOPMENT OF THE LONG WAVE TROUGH INTO THE CENTRAL CONUS. IT/S NOW MORE IN LINE WITH THE 26/00Z GFS AND GFS ENSEMBLE MEAN...AND DIGS THE TROUGH INTO THE GREAT LAKES REGION WHERE A CLOSED UPPER LOW DEVELOPS DUE TO A BLOCKY DOWNSTREAM UPPER LEVEL RIDGE. CONFIDENCE HAS INCREASED SOMEWHAT IN THE FORECAST FOR MID TO LATE NEXT WEEK DUE TO THE BETTER MODEL AGREEMENT. IT APPEARS THAT MAINLY DRY AND COOL CONDITIONS WILL DEVELOP AFTER WEDNESDAY...BUT NOT AS COLD AS THE TEMPERATURES WE HAVE EXPERIENCED DURING THE PAST SEVERAL WEEKS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1230 AM CDT FRI APR 26 2013 WIND WILL CONTINUE TO DECREASE AND BECOME AT OR BELOW 10KT BEFORE SHIFTING AROUND TO THE NORTH TO NORTHEAST. IT WILL THEN SWING AROUND TO 020-040 BY 09Z BUT REMAIN LESS THAN 12KT. BY 15Z...THE WIND WILL INCREASE TO 10-12 IN NORTHERN NEBRASKA AND 12-14G21-23KT FROM 020-040 OVER CENTRAL AND SOUTHWEST NEBRASKA. && .FIRE WEATHER... ISSUED AT 337 AM CDT FRI APR 26 2013 VERY HIGH FIRE DANGER TODAY. 50 PERCENT OF THE RAP MODEL AND 50 PERCENT OF THE REST OF THE MODEL DATA PRODUCES RH AROUND 20 PERCENT BUT WINDS ARE LIGHT GUSTING TO JUST 20 MPH. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...TAYLOR AVIATION...SPRINGER FIRE WEATHER...CDC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
133 AM EDT FRI APR 26 2013 .SYNOPSIS... A DRYING TREND IS EXPECTED FRIDAY INTO SATURDAY AS HIGH PRESSURE REACHES DOWN FROM THE NORTH. AS THIS HIGH PRESSURE SHIFTS OFF SHORE AN AREA OF LOW PRESSURE WILL AFFECT THE SOUTHEAST PRODUCING AN EXTENDED PERIOD OF UNSETTLED WEATHER THROUGH THE LATTER HALF OF THE WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... AS OF 130 AM FRIDAY...BIGGEST CHANGE TO THE FORECAST IS TO INCLUDE THE EXPANSIVE AREA OF LOW STRATUS THAT HAS BEEN MOVING STEADILY WESTWARD ACROSS EASTERN SOUTH CAROLINA FOR THE PAST SEVERAL HOURS. CLOUD CEILINGS ARE AS LOW AS 500-700 FT AGL...AND THIS MOISTURE APPEARS TO BE ADVECTING WESTWARD ALONG THE LEADING EDGE OF AN OTHERWISE SLIGHT INCREASE IN WINDS AT THE TOP OF THE BOUNDARY LAYER. FORECAST SOUNDINGS FROM THE NAM AND RUC DO NOT SHOW ENOUGH WIND SHEAR IN THE LOWEST 1000 FT TO PREVENT FOG DEVELOPMENT GIVEN THE SMALL TEMPERATURE-DEWPOINT DEPRESSIONS NOTED VIRTUALLY ALL ACROSS THE EASTERN CAROLINAS...SO I HAVE ADDED AREAS OF FOG TO THE FORECAST FOR MAINLY INLAND AREAS. PREVIOUS DISCUSSION FROM 1030 PM FOLLOWS... UPDATED FORECASTS AND GRIDS TO REMOVE ALL POPS AND PCPN OVER LAND AREAS. THE BEST FORCING WILL PULL AWAY FROM THE FA...REMAINING OVER THE OFFSHORE ATL WATERS. THE WARMER SSTS OF THE GULF STREAM WILL AID PCPN DEVELOPMENT AND THE CONVECTION AS IT PUSHES FURTHER AWAY FROM THE MAINLAND. SATELLITE IMAGERY TRENDS AND LATEST MODEL GUIDANCE INDICATE CLOUDS TO DISSIPATE AND CLEAR SKIES TO OVERSPREAD THE FA FROM THE W THRU NW. COULD OBSERVE LEFTOVER LOW LEVEL CONVECTIVE DEBRIS CLOUDS ACROSS THE SOUTHERNMOST PORTIONS OF THE ILM CWA THROUGH MIDNIGHT...BUT THESE TOO SHOULD SCOUR OUT DURING THE PRE-DAWN FRIDAY HRS. HAVE SLIGHT MODIFIED/TWEAKED OVERNIGHT MINS AND ESPECIALLY HOURLY DEWPOINTS TO ACCOUNT FOR THE EARLIER CONVECTION. DO NOT ANTICIPATE FOG OVERNITE...SINCE THE NE-E DRY AIR SURGE WILL ALSO KEEP ACTIVE MIXING IN THE LOW LEVELS. LOCATIONS WELL INLAND...ALONG AND WEST OF THE I-95 CORRIDOR WILL HAVE THE BEST SHOT TO SEE PATCHY FOG...BUT STILL JUST NOT ENOUGH TO ADVERTISE IN THE CURRENT FORECASTS. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... AS OF 3 PM THURSDAY...HIGH PRESSURE EXTENDING DOWN FROM THE GREAT LAKES ON FRIDAY WILL SHIFT EAST THROUGH SATURDAY REACHING OFF THE MID ATLANTIC COAST BY EARLY SUN MORNING. IN THE UPPER LEVELS A RIDGE TRIES TO BUILD UP FROM THE GULF COAST BUT A SHORTWAVE WILL RIDE OVER THE TOP OF IT FROM THE CENTRAL STATES TO THE OHIO VALLEY BY SUNDAY MORNING. OVERALL EXPECT FRIDAY TO REMAIN DRY WITH A FEW HIGH CLOUDS MAKING IT INTO AREA BUT BY SATURDAY INCREASING MID TO HIGH CLOUDS WILL REACH THE AREA FROM WEATHER ASSOCIATED WITH SHORTWAVE AND ASSOCIATED SURFACE LOW TRACKING EAST NORTHEAST. CLOUDS WILL CONTINUE TO INCREASE THROUGH LATE SATURDAY INTO EARLY SUNDAY AS MID TO HIGH LEVEL FLOW INCREASES OUT OF THE WEST NORTHWEST ADVECTING CLOUDS AND MOISTURE INTO AREA. BEST LIFT AND MOISTURE WILL REMAIN TO THE WEST OF OUR LOCAL FORECAST AREA. CAN NOT RULE OUT SOME PCP BUT OVERALL WILL KEEP LOW END POPS LIMITED TO WESTERN ZONES LATE SAT AFTN AND INCREASING SLIGHTLY THROUGH SAT NIGHT AS BEST SHORTWAVE ENERGY PASSES THROUGH. A COOLER NORTHEAST TO EASTERLY FLOW WILL PERSIST THROUGH THE PERIOD AS WINDS VEER AROUND AS THE HIGH SHIFTS EAST REMAINING NORTH OF AREA. THE E-NE FLOW SHOULD HELP THE SEA BREEZE PENETRATE INLAND FARTHER...ESPECIALLY ON SATURDAY WHEN WINDS ARE MORE EASTERLY. TEMPS WILL WARM INTO THE 70S BUT MAY GET A COUPLE OF DEGREES SHAVING OFF AS SEA BREEZE BRINGS COOLER OCEAN AIR INLAND THROUGH THE AFTN AND CLOUDS INCREASE TO HELP FILTER OUT THE SUN. OVERNIGHT LOWS WILL DROP JUST BELOW 50 INLAND AND LOWER 50S ALONG THE COAST FRI NIGHT WITH FEWER CLOUDS AND LIGHTER WINDS EXPECTED. BY SAT NIGHT...CLOUDS AND PCP WILL KEEP TEMPS IN THE 50S MOST PLACES. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 3 PM THURSDAY...SPLIT FLOW ALOFT EARLY IN THE PERIOD WILL TRANSITION TO A BLOCKING PATTERN AS WEAK REX BLOCK SETS UP. HIGH PRESSURE NORTH OF THE AREA WILL MAINTAIN NORTHEAST FLOW FOR MUCH OF THE PERIOD KEEPING TEMPERATURES NEAR TO BELOW CLIMO. LOW LEVEL NORTHEAST TO EAST FLOW AND SOUTHERLY MID LEVEL FLOW WILL KEEP PLENTY OF MOISTURE IN THE REGION. ALTHOUGH THERE ARE NO STRONGLY FORCED FEATURES DIURNAL HEATING...DESPITE CONSIDERABLE CLOUD COVER...AND DEVELOPING COASTAL TROUGH NEXT WEEK WILL HELP MAINTAIN SOME RAIN CHANCES FOR MUCH OF THE PERIOD. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AS OF 06Z...EXPECT VFR TO PREVAIL THROUGH THE VALID PERIOD. SLIGHTLY DRIER AIR IS ADVECTING IN AS HIGH PRESSURE FROM THE NORTH BUILDS INTO OUR AREA. CLEAR SKIES EXIST ALONG THE COAST...BUT AN EXPANSIVE AREA OF LOW STRATUS (BASES 500-1000 FT AGL) EXTENDING ACROSS DARLINGTON...FLORENCE AND GEORGETOWN SC WILL PUSH SLOWLY WEST INTO THE SC MIDLANDS OVER THE NEXT SEVERAL HOURS. AFTER DAYBREAK AND THROUGH THE REMAINDER OF THE PERIOD...ANTICIPATE NEARLY CLEAR SKIES WITH LIGHT NE WINDS...BECOMING MORE DIRECTLY ONSHORE DURING THE AFTERNOON AT CRE/MYR WITH THE SEABREEZE. EXTENDED OUTLOOK...VFR THROUGH SATURDAY AFTERNOON. UNSETTLED WEATHER SATURDAY NIGHT THROUGH TUESDAY AS A STATIONARY COASTAL TROUGH GIVES US MOSTLY CLOUDY CONDITIONS THROUGH TUESDAY WITH PERIODS OF RAIN AND IFR CONDITIONS. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 130 AM FRIDAY...MINIMAL SCA CONDITIONS REMAIN POSSIBLE OVER THE NC WATERS LATER THIS MORNING. SEAS HAVE BUILT TO 5 FT AT THE FRYING PAN SHOALS BUOY AND 4 FT AT THE NEARSHORE WRIGHTSVILLE BEACH BUOY...AS THE NE WIND CONTINUES AT 15-20 KT. PREVIOUS DISCUSSION FROM 1030 PM FOLLOWS... BORDERLINE SCA HAS BEEN RAISED FOR THE ILM NC WATERS...WITH SCEC CONTINUING FOR THE ILM SC WATERS. HAVE ALSO EXTENDED THE EXPIRATION OF BOTH THE SCA AND SCEC TO 6 PM FRIDAY. THE CURRENT NE-ENE SURGE HAS BEEN SLIGHTLY STRONGER THAN WHAT EARLIER MODEL GUIDANCE HAD FORECAST/INDICATED. WITH A 1030+ SFC HIGH RIDGING ACROSS THE FA FROM THE EASTERN GREAT LAKES AND THE ASSOCIATED SFC PG SLIGHTLY TIGHTER THAN GUIDANCE PROGGED...HAVE INCREASED THE NE-E WIND SPEEDS TO 15 TO 25 KT FOR THE ILM NC WATERS...AND 15-20 KT WITH FEW GUSTS TO 25 KT FOR THE ILM SC WATERS. THE BUILDING WIND DRIVEN WAVES FROM THE NE-E WIND SURGE WILL INTERACT WITH THE 2 TO 3 FOOT EASTERLY SWELL AT 9 SECOND PERIODS...TO ULTIMATELY PRODUCE 3 TO 6 FOOT SIGNIFICANT SEAS. THE 6 FOOTERS WILL OCCUR MAINLY OVER THE OUTER WATERS FROM SURF CITY TO CAPE FEAR. THE EARLIER CONVECTION HAS MOVED EAST AND OFFSHORE THIS EVENING AND DO NOT EXPECT ANY ADDITIONAL PCPN ACTIVITY. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 3 PM THURSDAY...HIGH PRESSURE WILL RIDGE DOWN FROM THE NORTH THROUGH THE PERIOD PRODUCING A MODEST NORTHEAST FLOW ON FRIDAY VEERING AROUND TO THE EAST AND LIGHTENING THROUGH SATURDAY AS CAA AND GRADIENT WEAKENS. WINDS WILL START OUT 15 TO 20 KTS OUT OF THE NORTHEAST BUT WILL DIMINISH THROUGH SAT NIGH INTO SUNDAY DOWN TO 10 TO 15 KTS. SEAS WILL BE LOWEST JUST SOUTH OF CAPE FEAR THROUGH BRUNSWICK COUNTY HAVING BEST PROTECTION FROM NORTHEAST FLOW...RUNNING AROUND 1 TO 2 FT. SEAS IN THE OUTER WATERS WILL BE GREATEST...UP AROUND 5 FT THROUGH SAT MORNING INTO SAT AFTN AND MAY SEE SOME 6 FOOTERS HEADING OUT TOWARD FRYING PAN SHOALS...WITH NORTHEAST WINDS UP CLOSE TO 20 KTS. A DECENT NORTHEASTERLY FLOW WILL BE IN PLACE AT THE BEGINNING OF THE PERIOD ON THE ORDER OF 10-15 KNOTS WITH A FEW PLACES ACROSS THE OUTER WATERS SEEING JUST OVER 15. AS COLD AIR ADVECTION WANES SO WILL THE WINDS BUT HIGH PRESSURE TO THE NORTHEAST WILL KEEP THIS FLOW IN PLACE WITH A SLIGHT DIURNAL VEERING VIA THE SEA BREEZE. SWAN SEAS ARE JUST UNDER SMALL CRAFT CRITERIA EARLY FRIDAY...3-5 FEET DROPPING TO 2-4 FEET BY SATURDAY. LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 3 PM THURSDAY...NORTHEAST TO EAST FLOW ACROSS THE WATERS SUN WILL BECOME SOUTHEAST MON/TUE AS WEAK COASTAL TROUGH TAKES SHAPE. WIND SPEEDS WILL BE 10 TO 15 KT FOR A MAJORITY OF THE PERIOD. SEAS WILL RUN 2 TO 4 FT THROUGH THE PERIOD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR AMZ250-252. && $$ SYNOPSIS...RGZ NEAR TERM...DCH/TRA SHORT TERM...RGZ LONG TERM...III AVIATION...SGL/TRA
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
438 AM EDT FRI APR 26 2013 .SYNOPSIS... A DRY RIDGE OF HIGH PRESSURE WILL GIVE WAY TO A WEDGE OF MOIST AND COOL AIR OVER THE WEEKEND. WEAK LOW PRESSURE WILL MOVE ACROSS THE TENNESSEE VALLEY ALONG A STALLED COLD FRONT OVER THE WEEKEND. THE FRONT WILL SLOWLY DISSIPATE AND THE COOL AIR WEDGE WILL GRADUALLY WEAKEN INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... 415 AM UPDATE...RE-EVALUATED FROST/FREEZE POTENTIAL FOR THIS MORNING. ASOS/AWOS NETWORK SUGGESTS LITTLE RISK OF FREEZE EXCEPT IN THE LITTLE TENN RIVER VALLEY PER LAST FEW FRANKLIN OBS. MESONET SITES HOWEVER REVEAL MANY SITES IN THE FREEZE WARNING AREA SITTING AT 34-35F AND THINK THERE IS STILL A DECENT CHANCE THEY WILL AT LEAST BRIEFLY FREEZE...WITH A COUPLE MORE HOURS OF CALM NIGHTTIME CONDITIONS TO GO. AS FOR FROST ADVY AREA IT IS LOOKING LIKE THE FROST WILL REMAIN PATCHY WITH MANY SITES STILL REPORTING 40S. HOWEVER RADIATION AND CALM CONDITIONS COULD MEAN SURFACES DIP WELL BELOW AIR TEMPS AND I WOULD PREFER TO ERR ON THE SIDE OF CAUTION AND MAINTAIN THE ADVY THIS LATE IN THE GAME. DID REVISE TEMP/DEWPT TRENDS THRU DAYBREAK USING LATEST OBS. AS OF 3 AM FRI...UPPER S/W TROUGH WILL CONTINUE TO ADVECT TOWARD THE ATLANTIC THIS MORNING WITH A FLAT RIDGE FILLING IN BEHIND IT. THIS WILL ALLOW SFC HIGH PRESENTLY OVER THE OHIO VALLEY TO SHIFT OVERHEAD LEADING TO A CALM AND PLEASANT DAY. WEAK DISTURBANCES IN THE UPPER FLOW ARE COLLOCATED WITH ENOUGH HIGH ALTITUDE MOISTURE TO EXPECT INCREASING AMOUNTS OF CIRRUS THROUGH THE DAY. WINDS WILL DIMINISH GOING INTO THE AFTERNOON ALONG WITH THE WEAKENING PRESSURE GRADIENT. DESPITE WHAT DIFFUSION MIGHT OCCUR THROUGH THE CIRRUS HIGH TEMPS SHOULD BE NEAR NORMAL. AS NEXT SHORTWAVE DIGS IN BEHIND THE UPPER RIDGE OVER THE SOUTHEAST...DEVELOPING A SFC LOW OVER THE LOWER MISS VALLEY...WARM ADVECTION BEGINS ALOFT BY THE END OF THE DAY FRIDAY ON SOUTHERLY WINDS. WINDS THROUGHOUT THE LOW TO MID LEVELS REMAIN WEAK BUT DO IMPROVE TOWARD DAWN SATURDAY. DEEP LAYER MOISTURE IMPROVES PER STEADILY INCREASING 1000-500MB RH OVERNIGHT. NONETHELESS ISENTROPIC FIELDS SUGGEST FORCING FROM THE WARM ADVECTION WILL BE WEAK ON ACCOUNT OF THE WEAK WINDS...WITH THE LLVL MOISTURE ARRIVING LATE IN THE PERIOD. BEST FRONTOGENETIC FORCING COMES AROUND 600MB WITH POCKET OF CHANNELED VORTICITY WHICH ARRIVES BY ABOUT 09Z SAT PER NAM...AND THIS IS WHAT WARRANTS MENTIONABLE POPS. THERE IS DECENT AGREEMENT AMONG NCEP MODELS AS WELL AS CMC GEM THAT A BAND OF PRECIP WILL DEVELOP OVER OUR SW ZONES. THIS IS WHERE THE WARM ADVECTION IS STRONGEST BUT PERHAPS UPSLOPING WILL AID PRECIP GENERATION AS WELL. DESPITE THE MODEL CONSENSUS THE FORCING STILL REMAINS SOMEWHAT QUESTIONABLE...SO I CHOSE TO KEEP CHC POPS AT BEST...AND MODEST QPF. SFC HIGH MOVES INTO FAVORABLE POSITION FOR CAD DEVELOPMENT THOUGH WITH THE PRECIP EXPECTED TO GET UNDERWAY LATE...HAVE KEPT LOW TEMPS NEAR MOS CONSENSUS. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 250 AM FRIDAY...THE FRONTAL ZONE OVER THE TENN AND OHIO VALLEY WILL REMAIN QUASI-STATIONARY AND UNDERGO GRADUAL FRONTOLYSIS THROUGH THE SHORT TERM...AS AN UPPER LOW SLOWLY DRIFTS EAST AND FILLS. A FETCH OF DEEP GULF MOISTURE WILL REMAIN OVER THE AREA THROUGH THE PERIOD. THE MAIN SOURCE OF FORCING WILL GENERALLY BE TIED TO MECHANICAL LIFT IN THE VICINITY OF THE HIGH TERRAIN...OWING TO MODERATELY STRONG SOUTHERLY FLOW. HOWEVER...PERIODS OF WIDESPREAD RAIN SHOULD ACCOMPANY THE APPROACH OF UPPER LEVEL SPEED MAXIMA. THIS APPEARS MOST LIKELY LATE SATURDAY NIGHT AND EARLY SUNDAY...AND WE HAVE FOCUSED THE HIGHEST POPS/QPF DURING THIS TIME. THE PATTERN SUPERFICIALLY RESEMBLES A HEAVY/POSSIBLY EXCESSIVE RAINFALL EVENT ACROSS OUR AREA...PARTICULARLY FOR THE SOUTHERN BLUE RIDGE AREAS... IN LIGHT OF THE DURATION OF DEEP MOISTURE AND SOUTHERLY FLOW. HOWEVER...THERE ARE SEVERAL LIMITING FACTORS...PROGGED PWAT ANOMALIES ARE VERY MODEST...ONLY SLIGHTLY ABOVE CLIMO. WITH A COOL AIR WEDGE EXPECTED TO BE IN PLACE UNTIL AT LEAST SUNDAY AFTERNOON... THERE IS NOT MUCH IN THE WAY OF INSTABILITY EXPECTED DURING THIS EVENT...AND IT CERTAINLY DOES NOT APPEAR THAT THE BEST PERIOD OF FORCING WILL OVERLAP WITH SIGNIFICANT BUOYANCY. THERE IS ALSO SOME DEGREE OF UNCERTAINTY REGARDING THE STRENGTH OF THE SOUTHERLY FLOW. THEREFORE...WHILE THE SOUTHERN ESCARPMENT AREAS SHOULD CERTAINLY SEE A NICE SOAK OVER THE TWO DAY PERIOD...EXCESSIVE RAINFALL POSSIBILITIES ARE STILL VERY UNCERTAIN (BUT NOT OUT OF THE QUESTION). CONFIDENCE IN THE TEMPERATURE FORECAST IS LOWER THAN USUAL...OWING TO THE LIKELIHOOD OF IN SITU CAD...BUT ALSO DUE TO UNCERTAINTY AS TO EXACTLY WHEN IT WILL BECOME ESTABLISHED. WITH THE SURFACE HIGH MOVING INTO AN INCREASINGLY UNFAVORABLE POSITION SUNDAY...IT ALSO APPEARS THAT SOME AREAS WILL LIKELY SEE EROSION OF THE COLD POOL BY THE END OF THE DAY...CREATING FURTHER COMPLICATIONS. REGARDLESS... WITH WIDESPREAD CLOUD COVER EXPECTED THROUGH THE PERIOD...MAXES ARE EXPECTED TO BE WELL BELOW NORMAL...WITH MINS AROUND TO SLIGHTLY ABOVE CLIMO THROUGH THE PERIOD. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 320 AM FRIDAY...WITH THE FRONTAL ZONE WASHING OUT TO OUR WEST...AND A WEAKNESS IN THE UPPER LEVEL HEIGHT FIELD PERSISTING... THE AREA SHOULD REMAIN UNDER A FAIRLY MOIST AND INCREASINGLY UNSTABLE AIR MASS THROUGH THE MEDIUM RANGE. THIS WILL SUPPORT ISOLATED/SCT SHOWERS AND THUNDERSTORMS THROUGH THE PERIOD...MAINLY OF THE DIURNAL VARIETY. THERE COULD BE A BRIEF REPRIEVE BY THE END OF THE PERIOD...AS THE GLOBAL MODELS HINT AT SURFACE LOW DEVELOPMENT OFF THE SOUTHEAST COAST...WHICH COULD WRAP DRIER AIR INTO THE AREA. HOWEVER...THIS IS QUITE UNCERTAIN AT THIS POINT...AND WITH THE LIKELY APPROACH OF A FRONTAL BOUNDARY FROM THE WEST BY THE END OF THE WEEK...WE DO NOT FEEL COMFORTABLE WITH A POP-LESS FORECAST AT THIS POINT...SO SLIGHT/LOW CHANCE POPS WILL CARRY THROUGH TO THURSDAY. TEMPS ARE EXPECTED TO HOVER AROUND CLIMO THROUGH THE PERIOD. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/... 09Z KCLT UPDATE...AS HRRR AND RAP DEPICTED EARLIER THIS MORNING COASTAL STRATUS ARE STRUGGLING TO PUSH FURTHER INLAND...SO STILL CONFIDENT WITH VFR FCST IN THE NEAR TERM. FCST FOR THE DAYTIME TODAY LOOKS GOOD AND AGREES WITH PUBLIC PACKAGE JUST RELEASED. PRECIP CHANCES WILL INCREASE AROUND THE REGION LATE TONIGHT...THOUGH ANY EFFECTS AT KCLT LOOK TO BE AFTER 06Z. LOWERING CLOUDS PRIOR TO THEN THOUGH GUIDANCE AGREES THESE WILL REMAIN WELL INTO THE VFR RANGE. PREV DISCUSSION...AT KCLT AND ELSEWHERE...IFR STRATUS PRESENT OVER CAROLINA COASTAL PLAIN ATTM MAKING SOME WESTWARD PROGRESS. HRRR AND RAP MESO MODELS SHOW THESE CLOUDS BUT DISSIPATE THEM WELL SOUTH AND EAST OF THE NEAREST AFFECTED SITE /KCLT/. GIVEN LARGE DEWPOINT DEPRESSIONS OVER THE FORECAST AREA AND SUBSIDENCE FROM BUILDING HIGH PRESSURE...GOOD CONFIDENCE IN VFR THROUGH DAYBREAK AND THROUGH THE TAF PERIOD AT THAT. NLY WINDS TONIGHT VEER THRU THE DAY TO ENE BY AFTERNOON /SLY AT KAVL/...WITH WINDS RELAXING THRU THE DAY AS HIGH BECOMES CENTERED OVERHEAD. CIRRUS WILL INCREASE BY AFTN AND ESPECIALLY AFTER 00Z AS BETTER UPPER MOISTURE AND WEAK DISTURBANCES PASS OVERHEAD. OUTLOOK...THE NEXT SYSTEM WILL BRING MOISTURE BACK INTO THE AREA FRIDAY NIGHT THRU THE WEEKEND. RESTRICTIONS IN CLOUDS/PRECIP WILL LIKELY RETURN DURING THIS PERIOD...PERHAPS AS SOON AS 12Z SAT NEAR THE BLUE RIDGE. CONFIDENCE TABLE... 08-14Z 14-20Z 20-02Z 02-08Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR GAZ010. NC...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR NCZ033-048>053- 058-059-062>064-501-503-505. FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR NCZ065-502-504- 506>510. SC...NONE. && $$ SYNOPSIS...JDL NEAR TERM...WIMBERLEY SHORT TERM...JDL LONG TERM...JDL AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
336 AM EDT FRI APR 26 2013 .SYNOPSIS... A DRY RIDGE OF HIGH PRESSURE WILL GIVE WAY TO A WEDGE OF MOIST AND COOL AIR OVER THE WEEKEND. WEAK LOW PRESSURE WILL MOVE ACROSS THE TENNESSEE VALLEY ALONG A STALLED COLD FRONT OVER THE WEEKEND. THE FRONT WILL SLOWLY DISSIPATE AND THE COOL AIR WEDGE WILL GRADUALLY WEAKEN INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3 AM FRI...UPPER S/W TROUGH WILL CONTINUE TO ADVECT TOWARD THE ATLANTIC THIS MORNING WITH A FLAT RIDGE FILLING IN BEHIND IT. THIS WILL ALLOW SFC HIGH PRESENTLY OVER THE OHIO VALLEY TO SHIFT OVERHEAD LEADING TO A CALM AND PLEASANT DAY. WEAK DISTURBANCES IN THE UPPER FLOW ARE COLLOCATED WITH ENOUGH HIGH ALTITUDE MOISTURE TO EXPECT INCREASING AMOUNTS OF CIRRUS THROUGH THE DAY. WINDS WILL DIMINISH GOING INTO THE AFTERNOON ALONG WITH THE WEAKENING PRESSURE GRADIENT. DESPITE WHAT DIFFUSION MIGHT OCCUR THROUGH THE CIRRUS HIGH TEMPS SHOULD BE NEAR NORMAL. AS NEXT SHORTWAVE DIGS IN BEHIND THE UPPER RIDGE OVER THE SOUTHEAST...DEVELOPING A SFC LOW OVER THE LOWER MISS VALLEY...WARM ADVECTION BEGINS ALOFT BY THE END OF THE DAY FRIDAY ON SOUTHERLY WINDS. WINDS THROUGHOUT THE LOW TO MID LEVELS REMAIN WEAK BUT DO IMPROVE TOWARD DAWN SATURDAY. DEEP LAYER MOISTURE IMPROVES PER STEADILY INCREASING 1000-500MB RH OVERNIGHT. NONETHELESS ISENTROPIC FIELDS SUGGEST FORCING FROM THE WARM ADVECTION WILL BE WEAK ON ACCOUNT OF THE WEAK WINDS...WITH THE LLVL MOISTURE ARRIVING LATE IN THE PERIOD. BEST FRONTOGENETIC FORCING COMES AROUND 600MB WITH POCKET OF CHANNELED VORTICITY WHICH ARRIVES BY ABOUT 09Z SAT PER NAM...AND THIS IS WHAT WARRANTS MENTIONABLE POPS. THERE IS DECENT AGREEMENT AMONG NCEP MODELS AS WELL AS CMC GEM THAT A BAND OF PRECIP WILL DEVELOP OVER OUR SW ZONES. THIS IS WHERE THE WARM ADVECTION IS STRONGEST BUT PERHAPS UPSLOPING WILL AID PRECIP GENERATION AS WELL. DESPITE THE MODEL CONSENSUS THE FORCING STILL REMAINS SOMEWHAT QUESTIONABLE...SO I CHOSE TO KEEP CHC POPS AT BEST...AND MODEST QPF. SFC HIGH MOVES INTO FAVORABLE POSITION FOR CAD DEVELOPMENT THOUGH WITH THE PRECIP EXPECTED TO GET UNDERWAY LATE...HAVE KEPT LOW TEMPS NEAR MOS CONSENSUS. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 250 AM FRIDAY...THE FRONTAL ZONE OVER THE TENN AND OHIO VALLEY WILL REMAIN QUASI-STATIONARY AND UNDERGO GRADUAL FRONTOLYSIS THROUGH THE SHORT TERM...AS AN UPPER LOW SLOWLY DRIFTS EAST AND FILLS. A FETCH OF DEEP GULF MOISTURE WILL REMAIN OVER THE AREA THROUGH THE PERIOD. THE MAIN SOURCE OF FORCING WILL GENERALLY BE TIED TO MECHANICAL LIFT IN THE VICINITY OF THE HIGH TERRAIN...OWING TO MODERATELY STRONG SOUTHERLY FLOW. HOWEVER...PERIODS OF WIDESPREAD RAIN SHOULD ACCOMPANY THE APPROACH OF UPPER LEVEL SPEED MAXIMA. THIS APPEARS MOST LIKELY LATE SATURDAY NIGHT AND EARLY SUNDAY...AND WE HAVE FOCUSED THE HIGHEST POPS/QPF DURING THIS TIME. THE PATTERN SUPERFICIALLY RESEMBLES A HEAVY/POSSIBLY EXCESSIVE RAINFALL EVENT ACROSS OUR AREA...PARTICULARLY FOR THE SOUTHERN BLUE RIDGE AREAS... IN LIGHT OF THE DURATION OF DEEP MOISTURE AND SOUTHERLY FLOW. HOWEVER...THERE ARE SEVERAL LIMITING FACTORS...PROGGED PWAT ANOMALIES ARE VERY MODEST...ONLY SLIGHTLY ABOVE CLIMO. WITH A COOL AIR WEDGE EXPECTED TO BE IN PLACE UNTIL AT LEAST SUNDAY AFTERNOON... THERE IS NOT MUCH IN THE WAY OF INSTABILITY EXPECTED DURING THIS EVENT...AND IT CERTAINLY DOES NOT APPEAR THAT THE BEST PERIOD OF FORCING WILL OVERLAP WITH SIGNIFICANT BUOYANCY. THERE IS ALSO SOME DEGREE OF UNCERTAINTY REGARDING THE STRENGTH OF THE SOUTHERLY FLOW. THEREFORE...WHILE THE SOUTHERN ESCARPMENT AREAS SHOULD CERTAINLY SEE A NICE SOAK OVER THE TWO DAY PERIOD...EXCESSIVE RAINFALL POSSIBILITIES ARE STILL VERY UNCERTAIN (BUT NOT OUT OF THE QUESTION). CONFIDENCE IN THE TEMPERATURE FORECAST IS LOWER THAN USUAL...OWING TO THE LIKELIHOOD OF IN SITU CAD...BUT ALSO DUE TO UNCERTAINTY AS TO EXACTLY WHEN IT WILL BECOME ESTABLISHED. WITH THE SURFACE HIGH MOVING INTO AN INCREASINGLY UNFAVORABLE POSITION SUNDAY...IT ALSO APPEARS THAT SOME AREAS WILL LIKELY SEE EROSION OF THE COLD POOL BY THE END OF THE DAY...CREATING FURTHER COMPLICATIONS. REGARDLESS... WITH WIDESPREAD CLOUD COVER EXPECTED THROUGH THE PERIOD...MAXES ARE EXPECTED TO BE WELL BELOW NORMAL...WITH MINS AROUND TO SLIGHTLY ABOVE CLIMO THROUGH THE PERIOD. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 320 AM FRIDAY...WITH THE FRONTAL ZONE WASHING OUT TO OUR WEST...AND A WEAKNESS IN THE UPPER LEVEL HEIGHT FIELD PERSISTING... THE AREA SHOULD REMAIN UNDER A FAIRLY MOIST AND INCREASINGLY UNSTABLE AIR MASS THROUGH THE MEDIUM RANGE. THIS WILL SUPPORT ISOLATED/SCT SHOWERS AND THUNDERSTORMS THROUGH THE PERIOD...MAINLY OF THE DIURNAL VARIETY. THERE COULD BE A BRIEF REPRIEVE BY THE END OF THE PERIOD...AS THE GLOBAL MODELS HINT AT SURFACE LOW DEVELOPMENT OFF THE SOUTHEAST COAST...WHICH COULD WRAP DRIER AIR INTO THE AREA. HOWEVER...THIS IS QUITE UNCERTAIN AT THIS POINT...AND WITH THE LIKELY APPROACH OF A FRONTAL BOUNDARY FROM THE WEST BY THE END OF THE WEEK...WE DO NOT FEEL COMFORTABLE WITH A POP-LESS FORECAST AT THIS POINT...SO SLIGHT/LOW CHANCE POPS WILL CARRY THROUGH TO THURSDAY. TEMPS ARE EXPECTED TO HOVER AROUND CLIMO THROUGH THE PERIOD. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... AT KCLT AND ELSEWHERE...IFR STRATUS PRESENT OVER CAROLINA COASTAL PLAIN ATTM MAKING SOME WESTWARD PROGRESS. HRRR AND RAP MESO MODELS SHOW THESE CLOUDS BUT DISSIPATE THEM WELL SOUTH AND EAST OF THE NEAREST AFFECTED SITE /KCLT/. GIVEN LARGE DEWPOINT DEPRESSIONS OVER THE FORECAST AREA AND SUBSIDENCE FROM BUILDING HIGH PRESSURE...GOOD CONFIDENCE IN VFR THROUGH DAYBREAK AND THROUGH THE TAF PERIOD AT THAT. NLY WINDS TONIGHT VEER THRU THE DAY TO ENE BY AFTERNOON /SLY AT KAVL/...WITH WINDS RELAXING THRU THE DAY AS HIGH BECOMES CENTERED OVERHEAD. CIRRUS WILL INCREASE BY AFTN AND ESPECIALLY AFTER 00Z AS BETTER UPPER MOISTURE AND WEAK DISTURBANCES PASS OVERHEAD. OUTLOOK...THE NEXT SYSTEM WILL BRING MOISTURE BACK INTO THE AREA FRIDAY NIGHT THRU THE WEEKEND. RESTRICTIONS IN CLOUDS/PRECIP WILL LIKELY RETURN DURING THIS PERIOD...PERHAPS AS SOON AS 12Z SAT NEAR THE BLUE RIDGE. CONFIDENCE TABLE... 07-13Z 13-19Z 19-01Z 01-07Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR GAZ010. NC...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR NCZ033-048>053- 058-059-062>064-501-503-505. FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR NCZ065-502-504- 506>510. SC...NONE. && $$ SYNOPSIS...JDL NEAR TERM...WIMBERLEY SHORT TERM...JDL LONG TERM...JDL AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
145 AM EDT FRI APR 26 2013 .SYNOPSIS... MILD HIGH PRESSURE WILL REMAIN ACROSS THE SOUTHEAST THROUGH TODAY. A LOW IN THE SOUTHERN PLAINS WILL APPROACH THE AREA LATE TONIGHT AND DRIFT NORTHEASTWARD THROUGH THE WEEKEND. HIGH PRESSURE WILL BUILD BACK IN FOR THE FIRST PART OF THE WEEK. && .NEAR TERM /THROUGH TODAY/... 115 AM UPDATE...FCST TEMPS FROM PREV SHIFT ARE WELL BELOW ALL NEW GUIDANCE...THE LATTER GENERALLY NOT SUPPORTING FROST/FREEZE HEADLINES. SOME MOUNTAIN VALLEYS ARE ALREADY IN THE MID 30S AND WITH SFC HIGH BUILDING TO OUR WEST...AND MOVING OUR WAY BEHIND DEPARTING SHORTWAVE TROUGH...RADIATIONAL COOLING SHOULD CONTINUE TO IMPROVE AND MAKE THE BEST OF THE DRY DEWPOINTS /GENERALLY 28-32F/ IN THE MTNS/FOOTHILLS. REVISED TRENDS SLIGHTLY WARMER BUT STILL EXPECT THE FROST/FREEZE TO BE POSSIBLE...AND WILL MAINTAIN CURRENT HEADLINES. AS OF 230 PM...LATEST SATELLITE IMAGES INDICATED CLEAR CONDITIONS ACROSS THE FORECAST AREA AND UPSTREAM. HIGH PRESSURE WILL BUILD OVER THE REGION THIS EVENING AND OVERNIGHT. AS HIGH PRESSURE APPROACHES...A DRY COLD FRONT IS EXPECTED TO PUSH OVER THE SOUTHERN APPALACHIANS. THE WINDS IN THE WAKE OF THE FRONT MAY REMAIN STEADY FROM THE NNW...BUT SHOULD BECOME LIGHT DURING THE PRE DAWN HOURS. THE COMBINATION OF CLEAR SKY...LIGHT TO CALM WINDS...AND WIDE EVENING DEWPOINT DEPRESSIONS SHOULD SUPPORT STEADY COOLING OVERNIGHT. MIN TEMPERATURES ARE FORECAST TO RANGE IN THE UPPER 20S TO LOW 30S ACROSS MOST OF THE NC MTNS. FOOTHILL AREAS MAY SUPPORT AREAS TO WIDESPREAD FROST...AREAS EAST WILL REMAIN TOO WARM FOR FROST BY 6 TO 8 DEGREES BELOW NORMAL. THE CURRENT FREEZE WARNING AND FROST ADVISORY IS WELL PLACED AND TIMED...NO CHANGES PLANNED FOR THIS FORECAST PACKAGE. FRIDAY...THE WEATHER WILL REMAIN FAIR UNDER RIDGE OF HIGH PRESSURE. I WILL FORECAST HIGH CLOUDS INCREASING FROM THE EAST...OTHERWISE...CONDITIONS SHOULD FAVOR MOSTLY TO PARTLY SUNNY. HIGH TEMPERATURES ARE FORECAST TO PEAK WITHIN 2 TO 4 DEGREES OF NORMAL. && .SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/... AS OF 230 PM EDT THU...A POSITIVE TILT SRN STREAM WAVE WILL MOVE ACROSS THE SRN TIER OF THE CONUS FRI NIGHT...WITH THE MAIN H5 LOW CENTER LIFTING UP THE OH VALLEY OVER THE WEEKEND. MOISTURE WILL DEEPEN ACROSS THE REGION FRI NIGHT THROUGH SAT...ALONG WITH IMPROVING UPPER LEVEL DIVERGENCE AS A JETLET MOVES E OFF THE DELMARVA COAST. LOWER LEVELS SHOULD BE A BIT SLOWER TO MOISTEN UP THROUGH SAT...BUT WITH LIKELY POPS W TO CHC E STILL EXPECTED IN GRADUALLY IMPROVING SRLY FLOW LATE DAY SAT. THE INCREASING CLOUDS SHOULD KEEP TEMPS NEARLY 10 DEGREES BELOW NORMAL MOST AREAS. A DEEPER SRLY FETCH OF MOISTURE WILL ARRIVE SAT NIGHT THROUGH SUNDAY...AS A BETTER BAROCLINIC ZONE SETS UP ACROSS THE REGION TO IMPROVE UPGLIDE. POPS HAVE BEEN PUSHED INTO THE HIGH LIKELY/LOW CATEGORICAL RANGE BY MIDDAY SUNDAY. MAX TEMPERATURES WILL BE EVEN COOLER ON SUNDAY AS UPGLIDE CREATES MORE PRECIPITATION INTO A WEAK HYBRID CAD SFC LAYER ACROSS THE REGION. INSTABILITY SHOULD REMAIN SHUNTED SW OF THE DEVELOPING SFC CAD FRONT...WITH LOW END THUNDER CHANCES ONLY ALONG THE SW FRINGE SUNDAY. PRECIPITATION RATES SHOULD BE TOO LOW FOR ANY HYDRO PROBLEMS TO DEVELOP...WITH BETTER RATES S AND SW OF THE FORECAST AREA IN THE MORE UNSTABLE AIR. A WEAK COLD FRONT WILL THEN ARRIVE FROM THE WEST SUNDAY NIGHT...ACCOMPANIED BY MID LEVEL DRYING TO TAPER POPS QUICKLY DOWN INTO THE CHC RANGE. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 240 PM EDT THU...HEIGHTS WILL RISE SLIGHTLY ALONG THE ERN SEABOARD ON MONDAY AS A DAMPENING UPPER WAVE MOVES OFF THE MID ATLANTIC COAST...WITH ADDITIONAL MID LEVEL DRYING OCCURRING. HOWEVER...A WEAKNESS WILL REMAIN OVER THE LOWER MS RIVER VALLEY ON MON AND DRIFT SLOWLY EWD ACROSS THE DEEP SOUTH THROUGH AT LEAST MID WEEK. IN ADDITION...PERSISTENT EASTERLY FLOW AROUND THE OFFSHORE RIDGE WILL PUMP ATLANTIC MOISTURE BACK INTO THE REGION. THIS WILL SURELY CONTRIBUTE TO AN EXTENDED MOSTLY CLOUDY PERIOD THROUGH AT LEAST MID WEEK. WILL FEATURE A SLIGHT DIURNAL PATTERN TO DAILY ISOLD TO SCT SHOWER COVERAGE ACROSS THE AREA. A PERSISTENT PATTERN OF WARM OVERNIGHT MINS AND WELL BELOW NORMAL AFTN MAXES WILL CONTINUE THROUGH THE PERIOD. A COLD FRONT MAY APPROACH FROM THE WEST ON THURSDAY...BUT WITH CONSIDERABLE MODEL SPREAD ON TIMING. IN ADDITION...THE RIDGE OVER THE NE U.S. MAY BECOME STRONG ENOUGH TO WRAP SOME DRIER AIR IN ON NE FLOW. THIS MAKES THE LATER WEEK FORECAST MUCH MORE UNCERTAIN. WILL FEATURE PERSISTENCE FOR NOW. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AT KCLT AND ELSEWHERE...IFR STRATUS PRESENT OVER CAROLINA COASTAL PLAIN ATTM MAKING SOME WESTWARD PROGRESS. HRRR AND RAP MESO MODELS SHOW THESE CLOUDS BUT DISSIPATE THEM WELL SOUTH AND EAST OF THE NEAREST AFFECTED SITE /KCLT/. GIVEN LARGE DEWPOINT DEPRESSIONS OVER THE FORECAST AREA AND SUBSIDENCE FROM BUILDING HIGH PRESSURE...GOOD CONFIDENCE IN VFR THROUGH DAYBREAK AND THROUGH THE TAF PERIOD AT THAT. NLY WINDS TONIGHT VEER THRU THE DAY TO ENE BY AFTERNOON /SLY AT KAVL/...WITH WINDS RELAXING THRU THE DAY AS HIGH BECOMES CENTERED OVERHEAD. CIRRUS WILL INCREASE BY AFTN AND ESPECIALLY AFTER 00Z AS BETTER UPPER MOISTURE AND WEAK DISTURBANCES PASS OVERHEAD. OUTLOOK...THE NEXT SYSTEM WILL BRING MOISTURE BACK INTO THE AREA FRIDAY NIGHT THRU THE WEEKEND. RESTRICTIONS IN CLOUDS/PRECIP WILL LIKELY RETURN DURING THIS PERIOD...PERHAPS AS SOON AS 12Z SAT NEAR THE BLUE RIDGE. CONFIDENCE TABLE... 05-11Z 11-17Z 17-23Z 23-05Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR GAZ010. NC...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR NCZ033-048>053- 058-059-062>064-501-503-505. FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR NCZ065-502-504- 506>510. SC...NONE. && $$ SYNOPSIS...PAT NEAR TERM...NED/WIMBERLEY SHORT TERM...HG LONG TERM...HG AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1155 PM CDT THU APR 25 2013 .AVIATION... A SURFACE TROUGH ALONG THE LOWER TEXAS COAST LATE THIS EVENING TO CONTINUE MOVING NORTHWARD DURING THE OVERNIGHT HOURS AS AN UPPER LEVEL DISTURBANCE CROSSES SOUTH CENTRAL TEXAS. WITH SURFACE DEWPOINTS IN THE MID 40S ACROSS MUCH OF OUR AREA AND MID 50S ACROSS THE COASTAL PLAINS AS OF 04Z...WITH MORE MOISTURE POOLING EXPECTED OVERNIGHT AND EARLY FRIDAY...MVFR/IFR CONDITIONS ARE EXPECTED ACROSS AREA TERMINALS THROUGH MIDDAY FRIDAY. ALSO...LIGHT RAIN OR DRIZZLE IS EXPECTED FOR THE OVERNIGHT/FRIDAY MORNING PERIOD. THERE MAY BE A TIME WHERE CIGS AND VSBYS COULD DROP TO LIFR CATEGORY AROUND 12Z/14Z ALONG I-35 SITES. MVFR/VFR CONDITIONS ARE EXPECTED TO RETURN AFTER 17Z FRIDAY. SOUTHEASTERLY FLOW WILL PREVAIL FOR MUCH OF THE FORECAST PERIOD WITH WIND SPEEDS OF 4 TO 9 KNOTS OVERNIGHT INCREASING TO 10 TO 15 KNOTS WITH HIGHER GUSTS FRIDAY AFTERNOON. && .PREV DISCUSSION... /ISSUED 952 PM CDT THU APR 25 2013/ UPDATE... A SURFACE TROUGH IS ALONG THE LOWER TEXAS COAST WITH A WARM FRONT DEVELOPING ALONG THE COAST. THE WARM FRONT WILL MOVE NORTH DURING THE OVERNIGHT HOURS AS THE LEFT ENTRANCE REGION OF AN UPPER LEVEL JET AND A WEAK MID LEVEL SHORT-WAVE MOVE ACROSS SOUTHERN TEXAS. UPWARD FORCING FROM THESE FEATURES WILL CAUSE PATCHY LIGHT RAIN OR DRIZZLE TO DEVELOP ACROSS SOUTH CENTRAL TEXAS DURING THE OVERNIGHT HOURS AS MENTIONED IN ONGOING FORECAST. TEMPERATURES RUNNING A DEGREE OR SO WARMER THAN FORECAST AND HAVE BOOSTED THEM SIMILARLY FOR THE REMAINDER OF TONIGHT INTO FRIDAY MORNING. SOME AREAS MAY SEE THEIR NIGHTTIME LOW IN THE NEXT FEW HOURS AND THEN RISE TOWARD MORNING AS DEWPOINTS CONTINUE TO INCREASE. REMAINDER OF SOUTH CENTRAL TEXAS FORECAST IS ON TRACK. CHANCES OF RAIN TREND HIGHER FOR THIS WEEKEND AS A SURFACE BOUNDARY AND SERIES OF WEAK UPPER LEVEL SHORT-WAVES INTERACT WITH INCREASING MOISTURE LEVELS TO ABOVE SEASONAL AVERAGES TO GENERATE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. THERE IS A POTENTIAL FOR STRONG TO MARGINALLY SEVERE STORMS TO DEVELOP ALONG THE FRONT OVER CENTRAL TEXAS AND OVER THE SERRANIAS DEL BURRO MOUNTAINS OF MEXICO AND THEN MOVE ACROSS SOUTH CENTRAL TEXAS ESPECIALLY SATURDAY AND SUNDAY NIGHTS. PREV DISCUSSION... /ISSUED 618 PM CDT THU APR 25 2013/ AVIATION... A SERIES OF UPPER SHORT-WAVE DISTURBANCES WILL COME ACROSS SOUTH CENTRAL TEXAS TONIGHT AND FRIDAY AS MAIN UPPER TROUGH CROSSES THE FOUR CORNERS REGION TONIGHT AND OVER THE TEXAS PANHANDLE FRIDAY MORNING. SOUTHEAST LOW LEVEL FLOW CONTINUES TO DOMINATE WITH DEWPOINTS IN THE UPPER 40S LATE THIS AFTERNOON...BUT INCREASING TO THE 50S AND 60S OVERNIGHT ACCORDING TO HIRES SOLUTIONS AND LATEST RUC13 GUIDANCE. THEREFORE...EXPECT CIGS TO LOWER TO MVFR AROUND 03Z TONIGHT AND LOWERING TO IFR AROUND OR AFTER 07Z...WITH POSSIBLE DRIZZLE/LIGHT RAIN ACROSS THE I-35 TERMINALS THROUGH 16Z FRIDAY. MVFR CONDITIONS WILL RETURN AND PREVAIL FOR THE REMAINDER OF THE FORECAST CYCLE. ACROSS KDRT...MVFR CIGS ARE EXPECTED AROUND 04Z TONIGHT AND PREVAIL TO ABOUT 17Z WITH VFR CONDITIONS RETURNING AFTERWARDS. SOUTHEASTERLY WINDS 4 TO 9 KNOTS ARE ANTICIPATED TONIGHT AND FRIDAY MORNING INCREASING 10 TO 15 KNOTS FRIDAY AFTERNOON. PREV DISCUSSION... /ISSUED 313 PM CDT THU APR 25 2013/ SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)... BOUNDARY LAYER WINDS HAVE BEGUN TO SHIFT TO THE EAST AND WILL CONTINUE TO VEER TO THE SOUTHEAST TONIGHT. THE ONSHORE FLOW WILL ADVECT GULF MOISTURE INTO THE REGION...KEEPING OVERCAST SKIES AND MILD TEMPERATURES TONIGHT. THE WARM AIR ADVECTION AND REMAINING SUBTLE ISENTROPIC LIFT SUGGEST THE POTENTIAL FOR ANOTHER ROUND OF EARLY MORNING LIGHT RAIN SHOWERS. SOME BREAKS IN THE CLOUD DECK ARE EXPECTED FRIDAY AFTERNOON WITH HIGHS REBOUNDING TO THE MID 70S TO LOW 80S. AN UPPER LEVEL LOW CURRENTLY MOVING ACROSS THE DESERT SOUTHWEST WILL EJECT TOWARD THE PLAINS STATES AS AN OPEN WAVE ON FRIDAY. THIS FEATURE WILL PROVIDE FOCUS FOR CONVECTION WELL NORTH OF OUR AREA...BUT COULD SEE ISOLATED SHOWERS/THUNDERSTORMS FRIDAY AFTERNOON ACROSS OUR NERN AREAS. FRIDAY NIGHT WILL BE MILD AND HUMID...BUT CHANCES FOR RAIN WILL BE WELL TO OUR NORTHEAST. LONG TERM (SATURDAY THROUGH THURSDAY)... A COLD FRONTAL BOUNDARY IN ASSOCIATION WITH THE SHORT-WAVE TROUGH WILL SKIRT ACROSS THE RED RIVER VALLEY FRIDAY NIGHT AND WILL STALL ACROSS CENTRAL TEXAS ON SATURDAY. THE FRONT IS NOT EXPECTED TO PUSH INTO OUR AREA...BUT WILL PROVIDE A FOCUS FOR ADDITIONAL CONVECTIVE ACTIVITY SATURDAY AND SATURDAY NIGHT. THERE IS ALSO THE POTENTIAL FOR ELEVATED CONVECTION TO DEVELOP ACROSS THE SERRANIAS DEL BURRO IN NERN MEXICO...AND A FEW STORMS MAY DRIFT ACROSS THE RIO GRANDE SATURDAY NIGHT/SUNDAY MORNING. WEAK ZONAL FLOW PREVAILING ALOFT AND THE LINGERING WASHED-OUT FRONTAL BOUNDARY WILL KEEP CHANCES FOR SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE REGION ON SUNDAY. BY SUNDAY NIGHT THE MOISTURE AXIS SHIFTS TO THE RIO GRANDE WITH ANOTHER ROUND OF BURRO MOUNTAIN STORMS POSSIBLE. THESE STORMS ARE KNOWN FOR THEIR POTENTIAL TO REACH SEVERE LEVELS AND/OR DEVELOP INTO MESO-SCALE CONVECTIVE SYSTEMS. OTHERWISE...THE SLOPPY PATTERN ALOFT WILL GENERALLY KEEP CONVECTIVE ACTIVITY SUB-SEVERE...BUT COULD SEE A FEW STORMS STRENGTHENED BY DIURNAL HEATING AND OUTFLOW BOUNDARIES AND POTENTIALLY BECOME STRONG. THE FRONT WILL RETREAT NORTHWARD ON MONDAY...BUT A WEAK UPPER DISTURBANCE WILL MOVE ACROSS THE REGION...KEEPING MENTIONABLE POPS IN THE FORECAST MONDAY AND TUESDAY. MODELS CONTINUE TO SUGGEST A MORE ORGANIZED PATTERN DEVELOPING ALOFT DURING THE MIDDLE OF THE WEEK WITH A COLD FRONT SOMETIME LATE WEDS/EARLY THURSDAY. TEMPERATURES WILL BE SEASONABLE AHEAD OF THE FRONT WITH HIGHS GENERALLY IN THE LOW 80S (MID-UPPER 80S OUT WEST) AND LOWS IN THE 60S. DESPITE THE DIFFERENCE IN TIMING OF THE FRONT FROM RUN-TO- RUN...MODELS HAVE BEEN CONSISTENT WITH THE STRENGTH OF THE FRONT. TEMPERATURES IN THE WAKE OF THE FRONT COULD POTENTIALLY BE 10 TO 15 DEGREES COOLER THAN WHAT WE`LL HAVE DURING THE MIDDLE OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 60 81 65 81 63 / 20 20 10 20 40 AUSTIN BERGSTROM INTL AIRPORT 57 80 64 80 61 / 20 20 10 20 40 NEW BRAUNFELS MUNI AIRPORT 60 82 65 80 64 / 20 20 10 20 40 BURNET MUNI AIRPORT 58 78 63 79 62 / 20 20 10 20 40 DEL RIO INTL AIRPORT 61 81 66 85 65 / 20 - - 20 40 GEORGETOWN MUNI AIRPORT 58 79 64 79 62 / 20 20 10 20 40 HONDO MUNI AIRPORT 59 82 65 81 64 / 20 10 10 20 40 SAN MARCOS MUNI AIRPORT 59 80 64 79 63 / 20 20 10 20 40 LA GRANGE - FAYETTE REGIONAL 62 82 66 80 65 / 20 20 10 20 20 SAN ANTONIO INTL AIRPORT 60 81 64 79 64 / 20 20 10 20 40 STINSON MUNI AIRPORT 60 81 65 80 65 / 20 20 10 20 40 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...17 SYNOPTIC/GRIDS...04
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
338 AM CDT FRI APR 26 2013 .SHORT TERM... TODAY AND TONIGHT. FORECAST CONFIDENCE MEDIUM. GFS STILL SHOWING HIGHER QPF AMOUNTS AND WIDER COVERAGE THAN OTHER MODELS WITH WARM AIR ADVECTION/SHORT WAVE-INDUCED PCPN EARLY THIS MORNING. NOT MUCH CURRENTLY GOING ON OUT WEST...BUT IR SATELLITE IMAGERY SHOWING AN ENHANCED BAND OF COLDER CLOUD TOPS DEVELOPING IN REGION OF STRENGTHENING FRONTOGENETIC RESPONSE AS EASTERN DAKOTA SHORT WAVE INTERACTS WITH AXIS OF 50-55 KT LOW-LEVEL JET AND ASSOCIATED ISENTROPIC ADIABATIC OMEGA. REGIONAL RADARS SHOW BLOSSOMING RETURNS WHICH ARE MAINLY VIRGA/SPRINKLES NEAR OUR FORECAST AREA WITH SHOWERS AND ISOLATED THUNDER FARTHER NORTH ON NOSE OF LLJ. LACK OF MEASURING GROUND TRUTH REFLECTING THE DRY AIR BELOW 6-7K FT ON THE 00Z MSP RAOB AND CURRENT RAP FORECAST SOUNDINGS FOR THE REGION. NORTHERN CWA WILL BE BRUSHED BY LOWER CONDENSATION PRESSURE DEFICITS...BUT THESE ARE ABOVE 700 MB ON 295K SURFACE WHILE STRONGER ISENTROPIC UPGLIDE IS LOWER IN REGION OF 100-200 MB PRESSURE DEFICITS...EVEN ON THE WETTER GFS. WILL LIMIT TO SPRINKLES ACROSS THE FAR NORTHERN CWA AFTER 09Z. SURFACE TROUGH LAYS OUT JUST TO THE NORTHWEST OF FORECAST AREA THIS AFTERNOON. RAP SOUNDINGS SHOW CAPE RISING AS HIGH AS 100-200 J/KG WITH LITTLE CIN THIS AFTERNOON...THOUGH PREDICATED ON DEW POINTS IN THE MID 50S. CAPE NON-EXISTENT WITH MORE REASONABLE AND DRIER SURFACE DEW POINTS ON NAM AND GFS SOUNDINGS...BUT PERSISTENT LOW-LEVEL FRONTOGENESIS AND SURFACE MOISTURE CONVERGENCE ALONG TROUGH AXIS REQUIRES A SLIGHT CHANCE IN THE NW CWA THIS AFTERNOON...ENDING AS SURFACE RIDGE NOSES IN FROM THE SOUTHEAST WIPING OUT WEAK TROUGH. HIGHS RISE INTO THE MID TO UPPER 60S INLAND...THOUGH LATE IN THE DAY AROUND 60 FAR EAST ALONG THE LAKE WITH GUSTY SOUTHWEST WINDS FINALLY ENDING COOLING ONSHORE COMPONENT OF SOUTH WINDS EARLY IN THE DAY. QUIET TONIGHT AS SURFACE RIDGE SETTLES OVER REGION...WITH LOWS IN THE 40S...EVEN ALONG THE LAKE AS SW WINDS CONTINUE OVERNIGHT THOUGH WEAKENING WINDS TOWARD MORNING MAY TURN WINDS ASHORE BEFORE DAYBREAK. SATURDAY THROUGH SUNDAY...FORECAST CONFIDENCE HIGH. A WEAK UPPER LOW WILL TRACK ACROSS MISSOURI AND ILLINOIS OVER THE WEEKEND. A HIGH PRESSURE RIDGE WILL SETTLE INTO SOUTHERN WI...AND WARMER AIR WILL SLOWLY BUT SURELY STREAM INTO THE AREA UNDER MOSTLY CLEAR SKIES. IT LOOKS LIKE A PLEASANT WEEKEND IS IN STORE WITH HIGHS REACHING AROUND 70 INLAND FROM THE LAKE BY SUNDAY. THE WEAK PRESSURE GRADIENT WILL ALLOW A LAKE BREEZE TO DEVELOP EACH DAY...KEEPING LAKESHORE AREAS IN THE UPPER 50S/LOWER 60S. .LONG TERM... SUNDAY NIGHT THROUGH MONDAY NIGHT...FORECAST CONFIDENCE MEDIUM. A SURFACE AND UPPER LEVEL TROUGH WILL SWING ACROSS THE UPPER MIDWEST SUNDAY NIGHT AND WEAKEN/STALL OVER CENTRAL/SOUTHERN WI THROUGH MONDAY. THERE IS DEBATE BETWEEN MODELS ABOUT WHETHER THAT FRONT WILL MOVE ALL THE WAY THROUGH SOUTHEAST WI OR REMAIN OVER CENTRAL WI. THERE IS A CHANCE THAT ANOTHER SHORTWAVE WILL MOVE INTO SOUTHERN WI ALONG A STALLED 850MB BAROCLINIC ZONE AND COMBINE WITH ISENTROPIC LIFT TO PRODUCE SHOWERS OVER SOUTHERN WI LATE SUN NIGHT THROUGH MON NIGHT. MODEL SOUNDINGS SHOW SURFACE BASED CAPE OF ALMOST 500 J/KG...SO KEPT MENTION OF THUNDER CHANCES. TEMPERATURES WILL BE ON THE RISE FOR MONDAY AHEAD OF THAT UPPER TROUGH...BUT AND SHOWERS/THUNDERSTORMS THAT DEVELOP COULD HINDER THE WARMEST TEMPS. GOOD CHANCE FOR 70 IN MOST PLACES INLAND FROM THE LAKE. TUESDAY THROUGH THURSDAY...FORECAST CONFIDENCE LOW TO MEDIUM. TEMPERATURES ARE EXPECTED TO RISE INTO AT LEAST THE MID 70S ON TUESDAY AHEAD OF AN APPROACHING COLD FRONT. EVENTUALLY A COLD FRONT WILL MOVE ACROSS SOUTHEAST WI WITH THE PASSAGE OF A DEEP UPPER TROUGH. TIMING OF THIS FRONT IS VERY UNCERTAIN. THE GFS BRINGS IT THROUGH MIDDAY WEDNESDAY...THE CANADIAN MODEL WEDNESDAY AFTERNOON...AND THE ECMWF NOT UNTIL THURSDAY MORNING. THERE WILL BE A CHANCE FOR SHOWERS AND THUNDERSTORMS AHEAD OF AND ALONG THE FRONT...AND A CHANCE FOR RAIN SHOWERS AND MAYBE A FEW SNOW SHOWERS JUST BEHIND THE FRONT. FRIDAY AND BEYOND...FORECAST CONFIDENCE MEDIUM. MODELS ALL CLOSE OFF THE 500MB TROUGH AND STALL IT OVER THE WESTERN GREAT LAKES REGION...KEEPING CHANCES FOR RAIN SHOWERS OR MAYBE EVEN SNOW SHOWERS OVER SOUTHERN WI INTO NEXT WEEKEND. && .AVIATION/12Z TAFS/... VFR CONDITIONS EXPECTED THROUGH THE PERIOD AS ANY LIGHT PRECIPITATION WITH SHORT WAVE CROSSING REGION AND STALLING SURFACE TROUGH EXPECTED TO REMAIN NORTH OF TAF SITES. GUSTY SW WINDS INTO THIS EVENING. LOW LEVEL MOISTURE THAT COULD BRING MVFR CLOUDS IN TONIGHT APPEARS TO BE PREDICATED ON OVERLY HIGH DEW POINTS. STILL A LATE NIGHT TURN OF THE SW WINDS TO SOUTH OR SOUTH-SOUTHEAST NEAR THE LAKE COULD BRING FOG TO EASTERN TAF SITES. && .MARINE...SOUTH WINDS WILL CONTINUE TO PICK UP THROUGH THE EARLY MORNING HOURS AHEAD OF LOW PRESSURE CROSSING SRN CANADA...THEN SHIFT SOUTHWEST THIS AFTERNOON AS SURFACE TROUGH STALLS ACROSS STATE...DIMINISHING TONIGHT AS RIDGE OF SURFACE HIGH PRESSURE NOSES OVER THE SOUTHERN PORTION OF THE LAKE. WILL KEEP CURRENT ADVISORY AS IS FOR SOUTHERN THREE ZONES...BUT EXTEND NORTHERN ZONE UNTIL 03Z TO ALLOW HIGHER WAVES THERE TO SUBSIDE. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 7 PM CDT THIS EVENING FOR LMZ644>646. SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 10 PM CDT THIS EVENING FOR LMZ643. && $$ TODAY/TONIGHT AND AVIATION/MARINE...REM SATURDAY THROUGH THURSDAY...MRC
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1011 AM EDT FRI APR 26 2013 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW && .SYNOPSIS... ISSUED AT 319 AM EDT FRI APR 26 2013 AN UPPER TROUGH AND A SURFACE LOW WILL MOVE THROUGH THE AREA THIS WEEKEND BRINGING SOME RAIN TO CENTRAL INDIANA. GENERALLY DRY CONDITIONS WILL THEN PREVAIL UNTIL A COLD FRONT ARRIVES MID WEEK NEXT WEEK AND BRINGS MORE CHANCES FOR RAIN. TEMPERATURES WILL GRADUALLY WARM TO ABOVE AVERAGE BY NEXT WEEK...BUT THEN FALL BEHIND THE COLD FRONT LATE IN THE WEEK. && .NEAR TERM /REST OF TODAY/... ISSUED AT 1003 AM EDT FRI APR 26 2013 A SUNNY START THIS MORNING ACROSS CENTRAL INDIANA ALTHOUGH HIGH CLOUDS ARE ALREADY RAPIDLY EXPANDING INTO THE WABASH VALLEY FROM THE WEST. WITH LIGHT SOUTHEAST FLOW AND WARM ADVECTION ONGOING... TEMPS HAVE RISEN QUICKLY SINCE DAYBREAK WITH MOST AREAS AS OF 14Z IN THE UPPER 40S AND LOWER 50S. HIGH PRESSURE CENTERED OVER SOUTHERN OHIO THIS MORNING CONTINUING TO INFLUENCE THE WEATHER ACROSS THE FORECAST AREA. THE HIGH WILL DRIFT EAST SLOWLY THROUGH THE AFTERNOON AS A WARM FRONT APPROACHES FROM THE SOUTHWEST. LARGE AREA OF PRECIP ASSOCIATED WITH THE WARM FRONT CURRENTLY ACROSS THE SOUTHERN HALF OF MISSOURI WILL GRADUALLY SHIFT NORTHEAST THROUGH THE REST OF THE DAY. WHILE CLOUDS WILL STEADILY INCREASE INTO THE AFTERNOON...CONTINUED SOUTHEAST FLOW WILL KEEP DRY CONDITIONS THROUGH THE BOUNDARY LAYER WITH RAINFALL LIKELY TO DIMINISH AS IT ENCOUNTERS INCREASINGLY DRIER AIR OVER THE REGION. RAP INDICATING INITIAL SURGE OF ISENTROPIC LIFT MAY MAKE IT INTO THE LOWER WABASH VALLEY FOR THE SECOND HALF OF THE AFTERNOON. WILL CONTINUE WITH LOW CHANCE POPS FOR LIGHT SHOWERS THERE AND MAINTAIN DRY FORECAST ELSEWHERE. CONSIDERING THE QUICK RISE THIS MORNING IN TEMPS...FORECAST HIGHS IN THE LOWER 60S LOOK REASONABLE EVEN WITH THE INCREASING CLOUD COVER. ZONE AND GRID UPDATES OUT. && .SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/... ISSUED AT 319 AM EDT FRI APR 26 2013 FOCUS IS ON CHANCES FOR RAIN THROUGH THE PERIOD. MODELS ARE CLOSE ENOUGH THAT A BLEND CAN BE USED FOR MOST ITEMS. ALTHOUGH ISENTROPIC LIFT WILL INCREASE GRADUALLY TONIGHT...MOST OF THE FORCING REMAINS SOUTH OF CENTRAL INDIANA. WILL GRADUALLY INCREASE POPS DURING THE TONIGHT PERIOD...BUT BY THE END OF THE PERIOD WILL ONLY HAVE LOW POPS ACROSS THE SOUTHWEST HALF OF THE AREA. ON SATURDAY AS THE UPPER TROUGH ENTERS THE AREA BY LATE IN THE DAY...POPS WILL CONTINUE THEIR GRADUAL INCREASE AS FORCING GRADUALLY INCREASES. BY THE END OF THE DAY THE SOUTHWEST THIRD OF THE AREA SHOULD SEE ENOUGH FORCING TO HAVE LIKELY POPS WITH LOW POPS NORTHEAST WHERE PRECIPITATION WILL BATTLE DRIER AIR. AS THE UPPER TROUGH MOVES ACROSS THE AREA AND LIFT INCREASES SATURDAY NIGHT...WENT LIKELY POPS MOST AREAS. WENT HIGHEST POPS SOUTHEAST WHERE IMPACTS OF STRONGER 850MB WINDS WILL BE FELT. ON SUNDAY AS SYSTEM SLOWLY MOVES EAST...CONTINUED LIKELY POPS EAST WITH CHANCE POPS WEST...WITH SOME DECREASE IN THE POPS IN THE AFTERNOON. ALTHOUGH THE LATEST MODEL RUNS HINT AT SOME LINGERING PRECIPITATION SUNDAY NIGHT...FOR NOW HAVE KEPT THE FORECAST DRY UNTIL THERE IS MORE AGREEMENT. FOR TEMPERATURES THROUGH THE PERIOD...TRENDED TOWARD THE COOLER OF THE MOS SATURDAY AND SUNDAY AND WARMER OF THE MOS SATURDAY NIGHT DUE TO THE CLOUDS AND PRECIPITATION. OTHERWISE WENT WITH A BLEND. && .LONG TERM /MONDAY THROUGH THURSDAY/... ISSUED AT 336 AM EDT FRI APR 26 2013 MAIN FOCUS ON THE EXTENDED WILL INVOLVE TIMING OF AN UPPER LOW THAT WILL MOVE TO THE UPPER MIDWEST BY THURSDAY. THE 00Z DETERMINISTIC GFS CONTINUES TO BE THE FASTEST MODEL MOVING THE UPPER LOW TO NORTHEASTERN WISCONSIN BY THAT TIME...WHILE THE 00Z ECMWF HAS IT FURTHER NORTHWEST AND NOT AS STRONG ACROSS WESTERN ONTARIO. THE 00Z GEFS FAVORED THE WEAKER ECMWF REGARDING STRENGTH AND WAS IN BETWEEN THE POSITIONING OF THE LOW ACROSS WESTERN LAKE SUPERIOR. SO...PREFER ENSEMBLE GUIDANCE...BUT WITH CONFIDENCE LOW DUE TO THE LARGE MODEL DIFFERENCES...PREFER TO STICK MOSTLY WITH THE INITIALIZATION REGARDING POPS AND TEMPERATURES. THE INITIALIZATION DID SPIT OUT SOME LOW POPS EARLY IN THE WEEK...BUT PREFERED TO REMAIN DRY THROUGH TUESDAY NIGHT WITH ONLY WEAK FORCING. THEN...CHANCE POPS INCREASING TOWARDS THURSDAY LOOK GOOD BASED ON THE ENSEMBLES AND WEAK FRONTAL SYSTEM THAT IS EXPECTED TO MOVE THROUGH WEDNESDAY NIGHT OR THURSDAY AHEAD OF THE UPPER SYSTEM. TEMPERATURES SHOULD ALSO CLIMB ABOVE NORMAL IN THE 70S MONDAY THROUGH AT LEAST WEDNESDAY WITH LIGHT SOUTHERLY FLOW AHEAD OF A WEAK FRONTAL SYSTEM. WITH TEMPERATURES IN THE 70S AND SOUTHERLY FLOW WILL ALSO LEAVE THUNDER IN. && .AVIATION /DISCUSSION FOR THE 26/15Z TAF UPDATE/... ISSUED AT 1009 AM EDT FRI APR 26 2013 UPDATE... NO CHANGES. PREVIOUS DISCUSSION... VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. WOULD NOT RULE OUT AN ISOLATED SHOWER OVERNIGHT AFTER 04Z AT HUF AND BMG...BUT COVERAGE TOO LOW AND TOO FAR OUT FOR A MENTION IN THE TAFS. OTHERWISE...HIGH AND MID CLOUDS WILL BE THICKENING TODAY WITH AN INCREASE IN DECK AROUND 5K FEET FROM SOUTHWEST TO NORTHEAST TOWARD 12Z SATURDAY. WINDS WILL INCREASE TO NEAR 10 KNOTS FROM THE SOUTH AFTER 13Z BEFORE BECOMING SOUTHEAST LESS THAN 5 KNOTS AFTER 00Z. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...50 NEAR TERM...RYAN SHORT TERM...50 LONG TERM....MK AVIATION...TDUD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1003 AM EDT FRI APR 26 2013 .UPDATE... THE NEAR TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 319 AM EDT FRI APR 26 2013 AN UPPER TROUGH AND A SURFACE LOW WILL MOVE THROUGH THE AREA THIS WEEKEND BRINGING SOME RAIN TO CENTRAL INDIANA. GENERALLY DRY CONDITIONS WILL THEN PREVAIL UNTIL A COLD FRONT ARRIVES MID WEEK NEXT WEEK AND BRINGS MORE CHANCES FOR RAIN. TEMPERATURES WILL GRADUALLY WARM TO ABOVE AVERAGE BY NEXT WEEK...BUT THEN FALL BEHIND THE COLD FRONT LATE IN THE WEEK. && .NEAR TERM /REST OF TODAY/... ISSUED AT 1003 AM EDT FRI APR 26 2013 A SUNNY START THIS MORNING ACROSS CENTRAL INDIANA ALTHOUGH HIGH CLOUDS ARE ALREADY RAPIDLY EXPANDING INTO THE WABASH VALLEY FROM THE WEST. WITH LIGHT SOUTHEAST FLOW AND WARM ADVECTION ONGOING... TEMPS HAVE RISEN QUICKLY SINCE DAYBREAK WITH MOST AREAS AS OF 14Z IN THE UPPER 40S AND LOWER 50S. HIGH PRESSURE CENTERED OVER SOUTHERN OHIO THIS MORNING CONTINUING TO INFLUENCE THE WEATHER ACROSS THE FORECAST AREA. THE HIGH WILL DRIFT EAST SLOWLY THROUGH THE AFTERNOON AS A WARM FRONT APPROACHES FROM THE SOUTHWEST. LARGE AREA OF PRECIP ASSOCIATED WITH THE WARM FRONT CURRENTLY ACROSS THE SOUTHERN HALF OF MISSOURI WILL GRADUALLY SHIFT NORTHEAST THROUGH THE REST OF THE DAY. WHILE CLOUDS WILL STEADILY INCREASE INTO THE AFTERNOON...CONTINUED SOUTHEAST FLOW WILL KEEP DRY CONDITIONS THROUGH THE BOUNDARY LAYER WITH RAINFALL LIKELY TO DIMINISH AS IT ENCOUNTERS INCREASINGLY DRIER AIR OVER THE REGION. RAP INDICATING INITIAL SURGE OF ISENTROPIC LIFT MAY MAKE IT INTO THE LOWER WABASH VALLEY FOR THE SECOND HALF OF THE AFTERNOON. WILL CONTINUE WITH LOW CHANCE POPS FOR LIGHT SHOWERS THERE AND MAINTAIN DRY FORECAST ELSEWHERE. CONSIDERING THE QUICK RISE THIS MORNING IN TEMPS...FORECAST HIGHS IN THE LOWER 60S LOOK REASONABLE EVEN WITH THE INCREASING CLOUD COVER. ZONE AND GRID UPDATES OUT. && .SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/... ISSUED AT 319 AM EDT FRI APR 26 2013 FOCUS IS ON CHANCES FOR RAIN THROUGH THE PERIOD. MODELS ARE CLOSE ENOUGH THAT A BLEND CAN BE USED FOR MOST ITEMS. ALTHOUGH ISENTROPIC LIFT WILL INCREASE GRADUALLY TONIGHT...MOST OF THE FORCING REMAINS SOUTH OF CENTRAL INDIANA. WILL GRADUALLY INCREASE POPS DURING THE TONIGHT PERIOD...BUT BY THE END OF THE PERIOD WILL ONLY HAVE LOW POPS ACROSS THE SOUTHWEST HALF OF THE AREA. ON SATURDAY AS THE UPPER TROUGH ENTERS THE AREA BY LATE IN THE DAY...POPS WILL CONTINUE THEIR GRADUAL INCREASE AS FORCING GRADUALLY INCREASES. BY THE END OF THE DAY THE SOUTHWEST THIRD OF THE AREA SHOULD SEE ENOUGH FORCING TO HAVE LIKELY POPS WITH LOW POPS NORTHEAST WHERE PRECIPITATION WILL BATTLE DRIER AIR. AS THE UPPER TROUGH MOVES ACROSS THE AREA AND LIFT INCREASES SATURDAY NIGHT...WENT LIKELY POPS MOST AREAS. WENT HIGHEST POPS SOUTHEAST WHERE IMPACTS OF STRONGER 850MB WINDS WILL BE FELT. ON SUNDAY AS SYSTEM SLOWLY MOVES EAST...CONTINUED LIKELY POPS EAST WITH CHANCE POPS WEST...WITH SOME DECREASE IN THE POPS IN THE AFTERNOON. ALTHOUGH THE LATEST MODEL RUNS HINT AT SOME LINGERING PRECIPITATION SUNDAY NIGHT...FOR NOW HAVE KEPT THE FORECAST DRY UNTIL THERE IS MORE AGREEMENT. FOR TEMPERATURES THROUGH THE PERIOD...TRENDED TOWARD THE COOLER OF THE MOS SATURDAY AND SUNDAY AND WARMER OF THE MOS SATURDAY NIGHT DUE TO THE CLOUDS AND PRECIPITATION. OTHERWISE WENT WITH A BLEND. && .LONG TERM /MONDAY THROUGH THURSDAY/... ISSUED AT 336 AM EDT FRI APR 26 2013 MAIN FOCUS ON THE EXTENDED WILL INVOLVE TIMING OF AN UPPER LOW THAT WILL MOVE TO THE UPPER MIDWEST BY THURSDAY. THE 00Z DETERMINISTIC GFS CONTINUES TO BE THE FASTEST MODEL MOVING THE UPPER LOW TO NORTHEASTERN WISCONSIN BY THAT TIME...WHILE THE 00Z ECMWF HAS IT FURTHER NORTHWEST AND NOT AS STRONG ACROSS WESTERN ONTARIO. THE 00Z GEFS FAVORED THE WEAKER ECMWF REGARDING STRENGTH AND WAS IN BETWEEN THE POSITIONING OF THE LOW ACROSS WESTERN LAKE SUPERIOR. SO...PREFER ENSEMBLE GUIDANCE...BUT WITH CONFIDENCE LOW DUE TO THE LARGE MODEL DIFFERENCES...PREFER TO STICK MOSTLY WITH THE INITIALIZATION REGARDING POPS AND TEMPERATURES. THE INITIALIZATION DID SPIT OUT SOME LOW POPS EARLY IN THE WEEK...BUT PREFERED TO REMAIN DRY THROUGH TUESDAY NIGHT WITH ONLY WEAK FORCING. THEN...CHANCE POPS INCREASING TOWARDS THURSDAY LOOK GOOD BASED ON THE ENSEMBLES AND WEAK FRONTAL SYSTEM THAT IS EXPECTED TO MOVE THROUGH WEDNESDAY NIGHT OR THURSDAY AHEAD OF THE UPPER SYSTEM. TEMPERATURES SHOULD ALSO CLIMB ABOVE NORMAL IN THE 70S MONDAY THROUGH AT LEAST WEDNESDAY WITH LIGHT SOUTHERLY FLOW AHEAD OF A WEAK FRONTAL SYSTEM. WITH TEMPERATURES IN THE 70S AND SOUTHERLY FLOW WILL ALSO LEAVE THUNDER IN. && .AVIATION /DISCUSSION FOR THE 26/12Z TAF ISSUANCE/... ISSUED AT 530 AM EDT FRI APR 26 2013 VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. WOULD NOT RULE OUT AN ISOLATED SHOWER OVERNIGHT AFTER 04Z AT HUF AND BMG...BUT COVERAGE TOO LOW AND TOO FAR OUT FOR A MENTION IN THE TAFS. OTHERWISE...HIGH AND MID CLOUDS WILL BE THICKENING TODAY WITH AN INCREASE IN DECK AROUND 5K FEET FROM SOUTHWEST TO NORTHEAST TOWARD 12Z SATURDAY. WINDS WILL INCREASE TO NEAR 10 KNOTS FROM THE SOUTH AFTER 13Z BEFORE BECOMING SOUTHEAST LESS THAN 5 KNOTS AFTER 00Z. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...50 NEAR TERM...RYAN SHORT TERM...50 LONG TERM....MK AVIATION...MK
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
913 AM CDT FRI APR 26 2013 .UPDATE... ISSUED AT 908 AM CDT FRI APR 26 2013 INCREASED POPS TODAY AS FIRST WAVE OF RAIN SHOWERS STEADILY MARCH NORTHEAST INTO THE FORECAST AREA. DRY LOW LEVELS ARE FIGHTING A LOSING BATTLE AND MEASURABLE PRECIPITATION HAS BEEN OBSERVED AS FAR EAST AS FARMINGTON ALREADY. COULD SEE A BREAK ALONG THE I-70 CORRIDOR THIS AFTERNOON BEFORE ROUND NUMBER TWO OVERSPREADS THE AREA IN ASSOCIATION WITH THE MAIN SHORTWAVE CURRENTLY LOCATED OVER COLORADO. CVKING && .SHORT TERM...(THROUGH LATE THIS AFTERNOON) ISSUED AT 353 AM CDT FRI APR 26 2013 THE PRIMARY FCST ISSUE FOR TODAY IS PCPN COVERAGE. EARLY MORNING WATER VAPOR IMAGERY AND RUC 1.5 PVU ANALYSES DEPICTED A COMPACT VORT MAX OVER MN AS WELL AS A SHORTWAVE NEAR THE FOUR CORNERS REGION. A BROAD AREA OF SHRA/TSRA HAS DEVELOPED ACROSS PARTS OF KS/OK/MO/AR IN RESPONSE TO A COMBINATION OF H9 FRONTOGENESIS AND H85-H7 MOISTURE CONVERGENCE FM THE LLJ AHEAD OF THE FOUR CORNERS SHORTWAVE. THIS 40-50KT SWLY LLJ /PER AREA VWP AND PROFILER OBS/ WAS TRANSPORTING MOISTURE INTO THE AREA AND LEADING TO AN INCREASE IN PCPN COVERAGE. ALTHOUGH MODELS GENERALLY SHOW A DECREASE IN THE LLJ THROUGH MID MORNING ACROSS MO/IL...THEY ALSO SHOW PERSISTENT AREAS OF ISENTROPIC ASCENT ALONG THE 295-305K SFCS /ESPECIALLY ACROSS THE SWRN CWA/ ALONG WITH AREAS OF INCREASED FRONTOGENESIS ALOFT. ALTHOUGH THE BEST FORCING FOR LARGE SCALE ASCENT WILL NOT ARRIVE UNTIL LATER TONIGHT AND THE LOW LEVEL AIR MASS WILL INITIALLY BE SOMEWHAT DRY...THE AFOREMENTIONED LIFTING MECHANISMS APPEAR SUFFICIENT TO CONTINUE POPS FOR SCT-INTERMITTENT SHRA TODAY. 42 .LONG TERM...(TONIGHT THROUGH THURSDAY) ISSUED AT 353 AM CDT FRI APR 26 2013 (TONIGHT - SATURDAY) A LARGELY NEUTRAL UPPER LEVEL FLOW WILL EXIST THRU SATURDAY...BUT THIS PERIOD WILL BE MOST MARKED BY A STRONG SHORTWAVE SLOWLY PASSING THRU. THE PROGRESSION OF THIS SYSTEM THRU THE BI-STATE WILL BE SLOW...WITH IT NOT EXPECTED TO PULL AWAY UNTIL LATE SATURDAY NIGHT. UNTIL SUNDAY...LOOK FOR CLOUDY SKIES WITH HI RAIN PROBS...EVEN THOUGH SOME AREAS MAY ONLY RECEIVE A FEW HUNDREDTHS WITH EXPECTED NATURE OF PCPN FOR MUCH OF THIS EVENT TO BE SHOWERY. MAIN AREAS TO KEY ON FOR RAIN TONIGHT WILL BE WHAT SHOULD BE A PERSISTENTLY STRONG REGION OF WAA AND H850-700 FRONTOGENESIS OVER SERN MO AND FAR SRN IL WHICH WILL REPRESENT THE BEST CHANCES FOR MEASURABLE...BUT A MORE BROADSCALE REGION OF MID LEVEL LIFT SHOULD ALSO WORK IN FOR THE REMAINDER OF THE AREA...ESPECIALLY W OF THE MS RIVER FOR ADDITIONAL LIGHT RAIN AMOUNTS. ON SATURDAY THE MEAT OF THE SYSTEM MOVES THRU WITH GENERALLY WEAK YET DEEP LIFT THRU A MOIST COLUMN...AND BUMPED POPS TO LIKELY FOR WIDESPREAD LIGHT RAINFALL AMOUNTS. THIS FINALLY BEGINS TO EXIT SATURDAY NIGHT WITH MOISTURE SLOWLY SCOURING OUT ALTHOUGH COULD SEE SHRA SIMPLY BE REPLACED BY DRIZZLE EARLY SUNDAY MORNING WITH LO CLOUDS BEING THE MOST STUBBORN OF ALL TO LEAVE. THE WARMER MAV MOS IS PREFERRED FOR MINS TONIGHT...WHILE WENT WITH THE COOLER MET MOS FOR MAXES SATURDAY TO PROMOTE A LO DIURNAL SWING WITH WHAT SHOULD BE THICK AND LO CLOUD COVER. AGAIN PREFERRED WARMER MAV MOS FOR SATURDAY NIGHT MINS. (SUNDAY - TUESDAY) UPPER LEVEL LONGWAVE RIDGE WILL BUILD OVER ERN NOAM WHILE A TROF DIGS IN THE W...RESULTING IN A WARM AND DRY PERIOD...WITH TEMPS PUSHING ABOVE AVERAGE FOR A COUPLE OF DAYS AT LEAST. WHILE DID UNDERCUT MOS MAX TEMPS ON SUNDAY DUE TO WHAT SHOULD BE STUBBORN LO CLOUD HANGING AROUND AND FINALLY LEAVING...MONDAY AND TUESDAY ARE EXPECTED TO FEATURE PLENTY OF SUNSHINE AND A DECENT S FLOW WITH RISING H500 HEIGHTS OVERHEAD. FCST H850/H900 TEMPS...IF THEY PAN OUT...WILL RESULT IN 75-80F FOR MONDAY AND AROUND 78-82F FOR TUESDAY. BUILDING RIDGE WILL EFFECTIVELY DEFLECT ANY SYSTEMS TO OUR N AND SHOULD KEEP OUR REGION DRY. (WEDNESDAY - THURSDAY) ALL OF THIS IS SHORT-LIVED...WITH THE UPPER LEVEL ERN NOAM RIDGE TO BREAKDOWN EITHER WEDNESDAY OR THURSDAY DEPENDING ON THE MODEL AND WILL BE ACCOMPANIED BY A STOUT CDFNT BACKED BY A STRONG CANADIAN AIRMASS. THE ECMWF PREFERS A SLOWER TIMING ON THURS WHILE THE GFS FAVORS WEDNESDAY. HAVE STRETCHED POPS FOR WED-THU TO COVER TIMING DIFFS WITH FRONT AND DID NOT HIT THE COLD AIR AS MUCH ON THURSDAY FOR THE SAME REASONS. TES && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 605 AM CDT FRI APR 26 2013 AN AREA OF SHOWERS WITH EMBEDDED THUNDERSTORMS HAS DEVELOPED ACROSS THE REGION THIS MORNING AHEAD OF AN UPPER LEVEL DISTURBANCE. SHOWERS ARE EXPECTED TO SPREAD EWD WITH TIME TODAY HOWEVER THE INITIALLY DRY AIR AT LOW LEVELS WILL DELAY THE ONSET OF PCPN AT THE GROUND. IT LOOKS LIKE THERE WILL BE A BREAK IN THE RAIN FOR A FEW HOURS DURING THE AFTN OR EVENING BEFORE THE NEXT WAVE OF PCPN DVLPS AND REACHES THE TERMINALS. UPSTREAM OBS SHOW THAT IT HAS BEEN DIFFICULT FOR CONDITIONS TO FALL BELOW VFR DUE TO THE DRY AIR AND HIGH CLOUD BASES. AFTER A DAY OF GRADUAL TOP-DOWN SATURATION...CONDITIONS ARE EXPECTED TO DETERIORATE TO MVFR AND POSSIBLY IFR WITH THE NEXT WAVE OF PCPN WHEN IT OCCURS LATER TONIGHT. INITIALLY SLY WINDS WILL BACK AND BECOME NEARLY ELY BY THE END OF THE TAF PD. SPECIFICS FOR KSTL...AN AREA OF SHOWERS WITH EMBEDDED THUNDERSTORMS HAS DEVELOPED AHEAD OF AN UPPER LEVEL DISTURBANCE. PCPN IS EXPECTED TO REACH KSTL WITHIN THE NEXT SEVERAL HOURS HOWEVER UPSTREAM OBS SHOW THAT IT HAS BEEN DIFFICULT FOR CONDITIONS TO FALL BELOW VFR DUE TO THE DRY AIR AND HIGH CLOUD BASES. ANOTHER WAVE OF PCPN IS EXPECTED TO DVLP LATER TONIGHT AS THE UPPER LEVEL DISTURBANCE APPROACHES KSTL. CONDITIONS WILL PROBABLY DETERIORATE TO MVFR AND POSSIBLY IFR IN THE SECOND WAVE DEPENDING ON HOW MUCH SATURATION OCCURS DURING THE DAY TODAY. INITIALLY SLY WINDS WILL BACK AND BECOME NEARLY ELY BY THE END OF THE TAF PD. KANOFSKY && .LSX WATCHES/WARNINGS/ADVISORIES... MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
629 AM CDT FRI APR 26 2013 .SHORT TERM...(THROUGH LATE THIS AFTERNOON) ISSUED AT 353 AM CDT FRI APR 26 2013 THE PRIMARY FCST ISSUE FOR TODAY IS PCPN COVERAGE. EARLY MORNING WATER VAPOR IMAGERY AND RUC 1.5 PVU ANALYSES DEPICTED A COMPACT VORT MAX OVER MN AS WELL AS A SHORTWAVE NEAR THE FOUR CORNERS REGION. A BROAD AREA OF SHRA/TSRA HAS DEVELOPED ACROSS PARTS OF KS/OK/MO/AR IN RESPONSE TO A COMBINATION OF H9 FRONTOGENESIS AND H85-H7 MOISTURE CONVERGENCE FM THE LLJ AHEAD OF THE FOUR CORNERS SHORTWAVE. THIS 40-50KT SWLY LLJ /PER AREA VWP AND PROFILER OBS/ WAS TRANSPORTING MOISTURE INTO THE AREA AND LEADING TO AN INCREASE IN PCPN COVERAGE. ALTHOUGH MODELS GENERALLY SHOW A DECREASE IN THE LLJ THROUGH MID MORNING ACROSS MO/IL...THEY ALSO SHOW PERSISTENT AREAS OF ISENTROPIC ASCENT ALONG THE 295-305K SFCS /ESPECIALLY ACROSS THE SWRN CWA/ ALONG WITH AREAS OF INCREASED FRONTOGENESIS ALOFT. ALTHOUGH THE BEST FORCING FOR LARGE SCALE ASCENT WILL NOT ARRIVE UNTIL LATER TONIGHT AND THE LOW LEVEL AIR MASS WILL INITIALLY BE SOMEWHAT DRY...THE AFOREMENTIONED LIFTING MECHANISMS APPEAR SUFFICIENT TO CONTINUE POPS FOR SCT-INTERMITTENT SHRA TODAY. 42 .LONG TERM...(TONIGHT THROUGH THURSDAY) ISSUED AT 353 AM CDT FRI APR 26 2013 (TONIGHT - SATURDAY) A LARGELY NEUTRAL UPPER LEVEL FLOW WILL EXIST THRU SATURDAY...BUT THIS PERIOD WILL BE MOST MARKED BY A STRONG SHORTWAVE SLOWLY PASSING THRU. THE PROGRESSION OF THIS SYSTEM THRU THE BI-STATE WILL BE SLOW...WITH IT NOT EXPECTED TO PULL AWAY UNTIL LATE SATURDAY NIGHT. UNTIL SUNDAY...LOOK FOR CLOUDY SKIES WITH HI RAIN PROBS...EVEN THOUGH SOME AREAS MAY ONLY RECEIVE A FEW HUNDREDTHS WITH EXPECTED NATURE OF PCPN FOR MUCH OF THIS EVENT TO BE SHOWERY. MAIN AREAS TO KEY ON FOR RAIN TONIGHT WILL BE WHAT SHOULD BE A PERSISTENTLY STRONG REGION OF WAA AND H850-700 FRONTOGENESIS OVER SERN MO AND FAR SRN IL WHICH WILL REPRESENT THE BEST CHANCES FOR MEASURABLE...BUT A MORE BROADSCALE REGION OF MID LEVEL LIFT SHOULD ALSO WORK IN FOR THE REMAINDER OF THE AREA...ESPECIALLY W OF THE MS RIVER FOR ADDITIONAL LIGHT RAIN AMOUNTS. ON SATURDAY THE MEAT OF THE SYSTEM MOVES THRU WITH GENERALLY WEAK YET DEEP LIFT THRU A MOIST COLUMN...AND BUMPED POPS TO LIKELY FOR WIDESPREAD LIGHT RAINFALL AMOUNTS. THIS FINALLY BEGINS TO EXIT SATURDAY NIGHT WITH MOISTURE SLOWLY SCOURING OUT ALTHOUGH COULD SEE SHRA SIMPLY BE REPLACED BY DRIZZLE EARLY SUNDAY MORNING WITH LO CLOUDS BEING THE MOST STUBBORN OF ALL TO LEAVE. THE WARMER MAV MOS IS PREFERRED FOR MINS TONIGHT...WHILE WENT WITH THE COOLER MET MOS FOR MAXES SATURDAY TO PROMOTE A LO DIURNAL SWING WITH WHAT SHOULD BE THICK AND LO CLOUD COVER. AGAIN PREFERRED WARMER MAV MOS FOR SATURDAY NIGHT MINS. (SUNDAY - TUESDAY) UPPER LEVEL LONGWAVE RIDGE WILL BUILD OVER ERN NOAM WHILE A TROF DIGS IN THE W...RESULTING IN A WARM AND DRY PERIOD...WITH TEMPS PUSHING ABOVE AVERAGE FOR A COUPLE OF DAYS AT LEAST. WHILE DID UNDERCUT MOS MAX TEMPS ON SUNDAY DUE TO WHAT SHOULD BE STUBBORN LO CLOUD HANGING AROUND AND FINALLY LEAVING...MONDAY AND TUESDAY ARE EXPECTED TO FEATURE PLENTY OF SUNSHINE AND A DECENT S FLOW WITH RISING H500 HEIGHTS OVERHEAD. FCST H850/H900 TEMPS...IF THEY PAN OUT...WILL RESULT IN 75-80F FOR MONDAY AND AROUND 78-82F FOR TUESDAY. BUILDING RIDGE WILL EFFECTIVELY DEFLECT ANY SYSTEMS TO OUR N AND SHOULD KEEP OUR REGION DRY. (WEDNESDAY - THURSDAY) ALL OF THIS IS SHORT-LIVED...WITH THE UPPER LEVEL ERN NOAM RIDGE TO BREAKDOWN EITHER WEDNESDAY OR THURSDAY DEPENDING ON THE MODEL AND WILL BE ACCOMPANIED BY A STOUT CDFNT BACKED BY A STRONG CANADIAN AIRMASS. THE ECMWF PREFERS A SLOWER TIMING ON THURS WHILE THE GFS FAVORS WEDNESDAY. HAVE STRETCHED POPS FOR WED-THU TO COVER TIMING DIFFS WITH FRONT AND DID NOT HIT THE COLD AIR AS MUCH ON THURSDAY FOR THE SAME REASONS. TES && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 605 AM CDT FRI APR 26 2013 AN AREA OF SHOWERS WITH EMBEDDED THUNDERSTORMS HAS DEVELOPED ACROSS THE REGION THIS MORNING AHEAD OF AN UPPER LEVEL DISTURBANCE. SHOWERS ARE EXPECTED TO SPREAD EWD WITH TIME TODAY HOWEVER THE INITIALLY DRY AIR AT LOW LEVELS WILL DELAY THE ONSET OF PCPN AT THE GROUND. IT LOOKS LIKE THERE WILL BE A BREAK IN THE RAIN FOR A FEW HOURS DURING THE AFTN OR EVENING BEFORE THE NEXT WAVE OF PCPN DVLPS AND REACHES THE TERMINALS. UPSTREAM OBS SHOW THAT IT HAS BEEN DIFFICULT FOR CONDITIONS TO FALL BELOW VFR DUE TO THE DRY AIR AND HIGH CLOUD BASES. AFTER A DAY OF GRADUAL TOP-DOWN SATURATION...CONDITIONS ARE EXPECTED TO DETERIORATE TO MVFR AND POSSIBLY IFR WITH THE NEXT WAVE OF PCPN WHEN IT OCCURS LATER TONIGHT. INITIALLY SLY WINDS WILL BACK AND BECOME NEARLY ELY BY THE END OF THE TAF PD. SPECIFICS FOR KSTL...AN AREA OF SHOWERS WITH EMBEDDED THUNDERSTORMS HAS DEVELOPED AHEAD OF AN UPPER LEVEL DISTURBANCE. PCPN IS EXPECTED TO REACH KSTL WITHIN THE NEXT SEVERAL HOURS HOWEVER UPSTREAM OBS SHOW THAT IT HAS BEEN DIFFICULT FOR CONDITIONS TO FALL BELOW VFR DUE TO THE DRY AIR AND HIGH CLOUD BASES. ANOTHER WAVE OF PCPN IS EXPECTED TO DVLP LATER TONIGHT AS THE UPPER LEVEL DISTURBANCE APPROACHES KSTL. CONDITIONS WILL PROBABLY DETERIORATE TO MVFR AND POSSIBLY IFR IN THE SECOND WAVE DEPENDING ON HOW MUCH SATURATION OCCURS DURING THE DAY TODAY. INITIALLY SLY WINDS WILL BACK AND BECOME NEARLY ELY BY THE END OF THE TAF PD. KANOFSKY && .LSX WATCHES/WARNINGS/ADVISORIES... MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
618 AM CDT FRI APR 26 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 337 AM CDT FRI APR 26 2013 A WEAK PACIFIC COLD FRONT WILL DROP THROUGH THE FCST AREA THIS MORNING. THE H850 MB THERMAL RIDGE SHOULD REDEVELOP SOMEWHAT THIS AFTERNOON. DEW POINTS IN THE 20S AND NEARLY FULL SUN SUPPORT MIXING TO 700 MB AND HIGHS AROUND 70. WINDS SFC TO 700 MB REMAIN MOSTLY NORTH AND WEAK AT 25 KTS OR LESS THROUGH TONIGHT WITH NEARLY NEUTRAL THERMAL ADVECTION. GIVEN THE DRY AIR...LOWS IN THE 30S TO NEAR 40 ARE FCST TONIGHT. A WEAK LOW LEVEL JET DEVELOPS TONIGHT ACROSS THE WEST LIMITING RADIATIONAL COOLING. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 337 AM CDT FRI APR 26 2013 WARM WEATHER IS EXPECTED THROUGH THE WEEKEND...WITH A COUPLE OF WEAK PACIFIC COLD FRONTAL PASSAGES. THESE WILL HAVE LITTLE AFFECT ON TEMPERATURES...AND HIGHS IN THE 70S TO NEAR 80 DEGREES ARE FORECASTED BOTH SATURDAY AND SUNDAY. MONDAY WILL CONTINUE TO BE WARM...WITH SOUTHERLY WINDS DEVELOPING IN RESPONSE TO DEVELOPING SFC LOW PRESSURE ACROSS WESTERN SOUTH DAKOTA. BY TUESDAY...A LONG WAVE TROUGH WILL BEGIN TO DIG SOUTH FROM CANADA INTO THE NORTHERN ROCKIES. THE 26/00Z RUN OF THE ECMWF LOOKS THE BEST FOR US IN REGARDS TO PRECIPITATION. IT STALLS A FRONT/SFC BOUNDARY TUESDAY ALONG THE NE/KS BORDER...WITH EASTERLY SFC WINDS ADVECTING SOME LOW LEVEL MOISTURE WESTWARD INTO SOUTHWEST NEBRASKA TO THE NORTH OF THE FRONT. TUESDAY NIGHT A STRONG SOUTHERLY LOW LEVEL JET DEVELOPS ACROSS KS...WHILE A NORTHERN PLAINS JET STREAK CROSSES THE DAKOTAS PLACING OUR AREA IN THE FAVORABLE RIGHT REAR QUADRANT. THE COMBINATION OF A STRONG LOW LEVEL JET AND FAVORABLE UPPER LEVEL JET DYNAMICS SHOULD SUPPORT AT LEAST SOME RISK OF ELEVATED CONVECTION NORTH OF THE SFC BOUNDARY ACROSS MUCH OF NEBRASKA. THE 26/00Z GFS INDICATES A SIMILAR SCENARIO...BUT STALLS THE FRONT FARTHER SOUTH. THIS WOULD KEEP THE BETTER PRECIPITATION CHANCES TO THE SOUTH AND EAST OF THE AREA. WILL CONTINUE TO MONITOR THE MODEL TRENDS REGARDING THE FRONTAL PLACEMENT AND SUBSEQUENT PRECIPITATION CHANCES. FOR NOW WILL CAP POPS AT 40 PERCENT UNTIL MODELS COME INTO BETTER AGREEMENT. BY MID TO LATE WEEK...THE 26/00Z RUN OF THE ECMWF HAS FINALLY LET GO OF IT/S SOUTHWARD DEVELOPMENT OF THE LONG WAVE TROUGH INTO THE CENTRAL CONUS. IT/S NOW MORE IN LINE WITH THE 26/00Z GFS AND GFS ENSEMBLE MEAN...AND DIGS THE TROUGH INTO THE GREAT LAKES REGION WHERE A CLOSED UPPER LOW DEVELOPS DUE TO A BLOCKY DOWNSTREAM UPPER LEVEL RIDGE. CONFIDENCE HAS INCREASED SOMEWHAT IN THE FORECAST FOR MID TO LATE NEXT WEEK DUE TO THE BETTER MODEL AGREEMENT. IT APPEARS THAT MAINLY DRY AND COOL CONDITIONS WILL DEVELOP AFTER WEDNESDAY...BUT NOT AS COLD AS THE TEMPERATURES WE HAVE EXPERIENCED DURING THE PAST SEVERAL WEEKS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 614 AM CDT FRI APR 26 2013 VFR IS EXPECTED ALL AREAS TODAY AND TONIGHT. SCATTERED HIGH AND MID LEVEL CLOUDINESS WILL CONTINUE. && .FIRE WEATHER... ISSUED AT 337 AM CDT FRI APR 26 2013 VERY HIGH FIRE DANGER TODAY. 50 PERCENT OF THE RAP MODEL AND 50 PERCENT OF THE REST OF THE MODEL DATA PRODUCES RH AROUND 20 PERCENT BUT WINDS ARE LIGHT GUSTING TO JUST 20 MPH. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...TAYLOR AVIATION...CDC FIRE WEATHER...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1057 AM CDT FRI APR 26 2013 .UPDATE...CURRENT FCST FOR THE TODAY PERIOD IS GENERALLY ON TRACK...WITH ONLY MINOR CHANGES MADE TO THE TODAY PERIOD. RADAR MOSAIC SHOWS SCATTERED SHOWERS LEFT OVER FROM THIS MORNING IN CENTRAL AND NORTHEAST WISCONSIN ASSOCIATED WITH A WARM FRONT PUSHING THROUGH. ELSEWHERE...SFC CHART SHOWS THAT TEMPERATURES HAVE ALREADY CLIMBED INTO THE MID AND UPPER 50S...WITH LNR AT 59...MSN AT 57...AND MKE AT 56 AS OF 10 AM. TEMPERATURE TREND WAS RUNNING A BIT COOL. AS SUCH...ADJUSTED TEMPS TO UPDATE TREND. FCST HIGHS THOUGH SHOULD BE FINE THOUGH. 925 TEMPS RANGE FROM 12-13 C GENERALLY THAT CORRESPONDS TO 65 TO 67 F...WHICH SEEM REASONABLE GIVEN THE ADEQUATE INSOLATION...DAYTIME MIXING...AND WINDS EXPECTED TODAY. SKIES SHOULD BE PARTLY TO MOSTLY SUNNY WITH SCT DIURNAL CU DEVELOPING. ET && .AVIATION/18Z TAFS/...VFR CONDITIONS EXPECTED THROUGH THIS EVENING ACROSS TAF SITES. GUSTY SOUTHWEST WINDS WILL LINGER THROUGH THE AFTERNOON...WITH GUSTS TO 27 KNOTS EXPECTED. WINDS WILL WEAKEN THIS EVENING AND LATER TONIGHT...BECOMING LIGHT AND VARIABLE BETWEEN 09Z AND 14Z SATURDAY. MILWAUKEE WILL STILL HAVE SOUTHWEST WINDS ABOVE 5 KNOTS. MVFR FOG IS EXPECTED AT MADISON...WAUKESHA AND KENOSHA BETWEEN 09Z AND 14Z SATURDAY. VFR CONDITIONS WILL RETURN AFTER 14Z SATURDAY...WITH LIGHT SOUTH WINDS BECOMING SOUTHEAST AT THE EASTERN SITES BY AFTERNOON. LIGHT SOUTH WINDS WILL LINGER AT MADISON. WOOD && .MARINE...SMALL CRAFT ADVISORY IN EFFECT UNTIL 7 PM SOUTH OF PORT WASHINGTON...AND UNTIL 10 PM NORTH OF THERE. TIGHT PRESSURE GRADIENT ALLOWING FOR GUSTY SOUTH WINDS...WHICH WILL PERSIST THROUGH THE DAY ACROSS THE NEARSHORE WATERS. FREQUENT GUSTS TO 25 KNOTS AND WAVES OF 2 TO 4 FEET ARE EXPECTED SOUTH OF PORT WASHINGTON. GUSTS TO 30 KNOTS AND WAVES OF 3 TO 5 FEET ARE EXPECTED NORTH OF THERE...LINGERING INTO THE EARLY EVENING HOURS. WINDS AND WAVES WILL SUBSIDE BY MIDDLE EVENING ACROSS THE AREA. WOOD && .PREV DISCUSSION... /ISSUED 338 AM CDT FRI APR 26 2013/ SHORT TERM... TODAY AND TONIGHT. FORECAST CONFIDENCE MEDIUM. GFS STILL SHOWING HIGHER QPF AMOUNTS AND WIDER COVERAGE THAN OTHER MODELS WITH WARM AIR ADVECTION/SHORT WAVE-INDUCED PCPN EARLY THIS MORNING. NOT MUCH CURRENTLY GOING ON OUT WEST...BUT IR SATELLITE IMAGERY SHOWING AN ENHANCED BAND OF COLDER CLOUD TOPS DEVELOPING IN REGION OF STRENGTHENING FRONTOGENETIC RESPONSE AS EASTERN DAKOTA SHORT WAVE INTERACTS WITH AXIS OF 50-55 KT LOW-LEVEL JET AND ASSOCIATED ISENTROPIC ADIABATIC OMEGA. REGIONAL RADARS SHOW BLOSSOMING RETURNS WHICH ARE MAINLY VIRGA/SPRINKLES NEAR OUR FORECAST AREA WITH SHOWERS AND ISOLATED THUNDER FARTHER NORTH ON NOSE OF LLJ. LACK OF MEASURING GROUND TRUTH REFLECTING THE DRY AIR BELOW 6-7K FT ON THE 00Z MSP RAOB AND CURRENT RAP FORECAST SOUNDINGS FOR THE REGION. NORTHERN CWA WILL BE BRUSHED BY LOWER CONDENSATION PRESSURE DEFICITS...BUT THESE ARE ABOVE 700 MB ON 295K SURFACE WHILE STRONGER ISENTROPIC UPGLIDE IS LOWER IN REGION OF 100-200 MB PRESSURE DEFICITS...EVEN ON THE WETTER GFS. WILL LIMIT TO SPRINKLES ACROSS THE FAR NORTHERN CWA AFTER 09Z. SURFACE TROUGH LAYS OUT JUST TO THE NORTHWEST OF FORECAST AREA THIS AFTERNOON. RAP SOUNDINGS SHOW CAPE RISING AS HIGH AS 100-200 J/KG WITH LITTLE CIN THIS AFTERNOON...THOUGH PREDICATED ON DEW POINTS IN THE MID 50S. CAPE NON-EXISTENT WITH MORE REASONABLE AND DRIER SURFACE DEW POINTS ON NAM AND GFS SOUNDINGS...BUT PERSISTENT LOW-LEVEL FRONTOGENESIS AND SURFACE MOISTURE CONVERGENCE ALONG TROUGH AXIS REQUIRES A SLIGHT CHANCE IN THE NW CWA THIS AFTERNOON...ENDING AS SURFACE RIDGE NOSES IN FROM THE SOUTHEAST WIPING OUT WEAK TROUGH. HIGHS RISE INTO THE MID TO UPPER 60S INLAND...THOUGH LATE IN THE DAY AROUND 60 FAR EAST ALONG THE LAKE WITH GUSTY SOUTHWEST WINDS FINALLY ENDING COOLING ONSHORE COMPONENT OF SOUTH WINDS EARLY IN THE DAY. QUIET TONIGHT AS SURFACE RIDGE SETTLES OVER REGION...WITH LOWS IN THE 40S...EVEN ALONG THE LAKE AS SW WINDS CONTINUE OVERNIGHT THOUGH WEAKENING WINDS TOWARD MORNING MAY TURN WINDS ASHORE BEFORE DAYBREAK. SATURDAY THROUGH SUNDAY...FORECAST CONFIDENCE HIGH. A WEAK UPPER LOW WILL TRACK ACROSS MISSOURI AND ILLINOIS OVER THE WEEKEND. A HIGH PRESSURE RIDGE WILL SETTLE INTO SOUTHERN WI...AND WARMER AIR WILL SLOWLY BUT SURELY STREAM INTO THE AREA UNDER MOSTLY CLEAR SKIES. IT LOOKS LIKE A PLEASANT WEEKEND IS IN STORE WITH HIGHS REACHING AROUND 70 INLAND FROM THE LAKE BY SUNDAY. THE WEAK PRESSURE GRADIENT WILL ALLOW A LAKE BREEZE TO DEVELOP EACH DAY...KEEPING LAKESHORE AREAS IN THE UPPER 50S/LOWER 60S. LONG TERM... SUNDAY NIGHT THROUGH MONDAY NIGHT...FORECAST CONFIDENCE MEDIUM. A SURFACE AND UPPER LEVEL TROUGH WILL SWING ACROSS THE UPPER MIDWEST SUNDAY NIGHT AND WEAKEN/STALL OVER CENTRAL/SOUTHERN WI THROUGH MONDAY. THERE IS DEBATE BETWEEN MODELS ABOUT WHETHER THAT FRONT WILL MOVE ALL THE WAY THROUGH SOUTHEAST WI OR REMAIN OVER CENTRAL WI. THERE IS A CHANCE THAT ANOTHER SHORTWAVE WILL MOVE INTO SOUTHERN WI ALONG A STALLED 850MB BAROCLINIC ZONE AND COMBINE WITH ISENTROPIC LIFT TO PRODUCE SHOWERS OVER SOUTHERN WI LATE SUN NIGHT THROUGH MON NIGHT. MODEL SOUNDINGS SHOW SURFACE BASED CAPE OF ALMOST 500 J/KG...SO KEPT MENTION OF THUNDER CHANCES. TEMPERATURES WILL BE ON THE RISE FOR MONDAY AHEAD OF THAT UPPER TROUGH...BUT AND SHOWERS/THUNDERSTORMS THAT DEVELOP COULD HINDER THE WARMEST TEMPS. GOOD CHANCE FOR 70 IN MOST PLACES INLAND FROM THE LAKE. TUESDAY THROUGH THURSDAY...FORECAST CONFIDENCE LOW TO MEDIUM. TEMPERATURES ARE EXPECTED TO RISE INTO AT LEAST THE MID 70S ON TUESDAY AHEAD OF AN APPROACHING COLD FRONT. EVENTUALLY A COLD FRONT WILL MOVE ACROSS SOUTHEAST WI WITH THE PASSAGE OF A DEEP UPPER TROUGH. TIMING OF THIS FRONT IS VERY UNCERTAIN. THE GFS BRINGS IT THROUGH MIDDAY WEDNESDAY...THE CANADIAN MODEL WEDNESDAY AFTERNOON...AND THE ECMWF NOT UNTIL THURSDAY MORNING. THERE WILL BE A CHANCE FOR SHOWERS AND THUNDERSTORMS AHEAD OF AND ALONG THE FRONT...AND A CHANCE FOR RAIN SHOWERS AND MAYBE A FEW SNOW SHOWERS JUST BEHIND THE FRONT. FRIDAY AND BEYOND...FORECAST CONFIDENCE MEDIUM. MODELS ALL CLOSE OFF THE 500MB TROUGH AND STALL IT OVER THE WESTERN GREAT LAKES REGION...KEEPING CHANCES FOR RAIN SHOWERS OR MAYBE EVEN SNOW SHOWERS OVER SOUTHERN WI INTO NEXT WEEKEND. AVIATION/12Z TAFS/... VFR CONDITIONS EXPECTED THROUGH THE PERIOD AS ANY LIGHT PRECIPITATION WITH SHORT WAVE CROSSING REGION AND STALLING SURFACE TROUGH EXPECTED TO REMAIN NORTH OF TAF SITES. GUSTY SW WINDS INTO THIS EVENING. LOW LEVEL MOISTURE THAT COULD BRING MVFR CLOUDS IN TONIGHT APPEARS TO BE PREDICATED ON OVERLY HIGH DEW POINTS. STILL A LATE NIGHT TURN OF THE SW WINDS TO SOUTH OR SOUTH-SOUTHEAST NEAR THE LAKE COULD BRING FOG TO EASTERN TAF SITES. MARINE...SOUTH WINDS WILL CONTINUE TO PICK UP THROUGH THE EARLY MORNING HOURS AHEAD OF LOW PRESSURE CROSSING SRN CANADA...THEN SHIFT SOUTHWEST THIS AFTERNOON AS SURFACE TROUGH STALLS ACROSS STATE...DIMINISHING TONIGHT AS RIDGE OF SURFACE HIGH PRESSURE NOSES OVER THE SOUTHERN PORTION OF THE LAKE. WILL KEEP CURRENT ADVISORY AS IS FOR SOUTHERN THREE ZONES...BUT EXTEND NORTHERN ZONE UNTIL 03Z TO ALLOW HIGHER WAVES THERE TO SUBSIDE. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LMZ644>646. SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LMZ643. && $$ UPDATE...ET/WOOD TODAY/TONIGHT AND AVIATION/MARINE...REM SATURDAY THROUGH THURSDAY...MRC
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
134 PM EDT FRI APR 26 2013 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW && .SYNOPSIS... ISSUED AT 319 AM EDT FRI APR 26 2013 AN UPPER TROUGH AND A SURFACE LOW WILL MOVE THROUGH THE AREA THIS WEEKEND BRINGING SOME RAIN TO CENTRAL INDIANA. GENERALLY DRY CONDITIONS WILL THEN PREVAIL UNTIL A COLD FRONT ARRIVES MID WEEK NEXT WEEK AND BRINGS MORE CHANCES FOR RAIN. TEMPERATURES WILL GRADUALLY WARM TO ABOVE AVERAGE BY NEXT WEEK...BUT THEN FALL BEHIND THE COLD FRONT LATE IN THE WEEK. && .NEAR TERM /REST OF TODAY/... ISSUED AT 1003 AM EDT FRI APR 26 2013 A SUNNY START THIS MORNING ACROSS CENTRAL INDIANA ALTHOUGH HIGH CLOUDS ARE ALREADY RAPIDLY EXPANDING INTO THE WABASH VALLEY FROM THE WEST. WITH LIGHT SOUTHEAST FLOW AND WARM ADVECTION ONGOING... TEMPS HAVE RISEN QUICKLY SINCE DAYBREAK WITH MOST AREAS AS OF 14Z IN THE UPPER 40S AND LOWER 50S. HIGH PRESSURE CENTERED OVER SOUTHERN OHIO THIS MORNING CONTINUING TO INFLUENCE THE WEATHER ACROSS THE FORECAST AREA. THE HIGH WILL DRIFT EAST SLOWLY THROUGH THE AFTERNOON AS A WARM FRONT APPROACHES FROM THE SOUTHWEST. LARGE AREA OF PRECIP ASSOCIATED WITH THE WARM FRONT CURRENTLY ACROSS THE SOUTHERN HALF OF MISSOURI WILL GRADUALLY SHIFT NORTHEAST THROUGH THE REST OF THE DAY. WHILE CLOUDS WILL STEADILY INCREASE INTO THE AFTERNOON...CONTINUED SOUTHEAST FLOW WILL KEEP DRY CONDITIONS THROUGH THE BOUNDARY LAYER WITH RAINFALL LIKELY TO DIMINISH AS IT ENCOUNTERS INCREASINGLY DRIER AIR OVER THE REGION. RAP INDICATING INITIAL SURGE OF ISENTROPIC LIFT MAY MAKE IT INTO THE LOWER WABASH VALLEY FOR THE SECOND HALF OF THE AFTERNOON. WILL CONTINUE WITH LOW CHANCE POPS FOR LIGHT SHOWERS THERE AND MAINTAIN DRY FORECAST ELSEWHERE. CONSIDERING THE QUICK RISE THIS MORNING IN TEMPS...FORECAST HIGHS IN THE LOWER 60S LOOK REASONABLE EVEN WITH THE INCREASING CLOUD COVER. ZONE AND GRID UPDATES OUT. && .SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/... ISSUED AT 319 AM EDT FRI APR 26 2013 FOCUS IS ON CHANCES FOR RAIN THROUGH THE PERIOD. MODELS ARE CLOSE ENOUGH THAT A BLEND CAN BE USED FOR MOST ITEMS. ALTHOUGH ISENTROPIC LIFT WILL INCREASE GRADUALLY TONIGHT...MOST OF THE FORCING REMAINS SOUTH OF CENTRAL INDIANA. WILL GRADUALLY INCREASE POPS DURING THE TONIGHT PERIOD...BUT BY THE END OF THE PERIOD WILL ONLY HAVE LOW POPS ACROSS THE SOUTHWEST HALF OF THE AREA. ON SATURDAY AS THE UPPER TROUGH ENTERS THE AREA BY LATE IN THE DAY...POPS WILL CONTINUE THEIR GRADUAL INCREASE AS FORCING GRADUALLY INCREASES. BY THE END OF THE DAY THE SOUTHWEST THIRD OF THE AREA SHOULD SEE ENOUGH FORCING TO HAVE LIKELY POPS WITH LOW POPS NORTHEAST WHERE PRECIPITATION WILL BATTLE DRIER AIR. AS THE UPPER TROUGH MOVES ACROSS THE AREA AND LIFT INCREASES SATURDAY NIGHT...WENT LIKELY POPS MOST AREAS. WENT HIGHEST POPS SOUTHEAST WHERE IMPACTS OF STRONGER 850MB WINDS WILL BE FELT. ON SUNDAY AS SYSTEM SLOWLY MOVES EAST...CONTINUED LIKELY POPS EAST WITH CHANCE POPS WEST...WITH SOME DECREASE IN THE POPS IN THE AFTERNOON. ALTHOUGH THE LATEST MODEL RUNS HINT AT SOME LINGERING PRECIPITATION SUNDAY NIGHT...FOR NOW HAVE KEPT THE FORECAST DRY UNTIL THERE IS MORE AGREEMENT. FOR TEMPERATURES THROUGH THE PERIOD...TRENDED TOWARD THE COOLER OF THE MOS SATURDAY AND SUNDAY AND WARMER OF THE MOS SATURDAY NIGHT DUE TO THE CLOUDS AND PRECIPITATION. OTHERWISE WENT WITH A BLEND. && .LONG TERM /MONDAY THROUGH THURSDAY/... ISSUED AT 336 AM EDT FRI APR 26 2013 MAIN FOCUS ON THE EXTENDED WILL INVOLVE TIMING OF AN UPPER LOW THAT WILL MOVE TO THE UPPER MIDWEST BY THURSDAY. THE 00Z DETERMINISTIC GFS CONTINUES TO BE THE FASTEST MODEL MOVING THE UPPER LOW TO NORTHEASTERN WISCONSIN BY THAT TIME...WHILE THE 00Z ECMWF HAS IT FURTHER NORTHWEST AND NOT AS STRONG ACROSS WESTERN ONTARIO. THE 00Z GEFS FAVORED THE WEAKER ECMWF REGARDING STRENGTH AND WAS IN BETWEEN THE POSITIONING OF THE LOW ACROSS WESTERN LAKE SUPERIOR. SO...PREFER ENSEMBLE GUIDANCE...BUT WITH CONFIDENCE LOW DUE TO THE LARGE MODEL DIFFERENCES...PREFER TO STICK MOSTLY WITH THE INITIALIZATION REGARDING POPS AND TEMPERATURES. THE INITIALIZATION DID SPIT OUT SOME LOW POPS EARLY IN THE WEEK...BUT PREFERED TO REMAIN DRY THROUGH TUESDAY NIGHT WITH ONLY WEAK FORCING. THEN...CHANCE POPS INCREASING TOWARDS THURSDAY LOOK GOOD BASED ON THE ENSEMBLES AND WEAK FRONTAL SYSTEM THAT IS EXPECTED TO MOVE THROUGH WEDNESDAY NIGHT OR THURSDAY AHEAD OF THE UPPER SYSTEM. TEMPERATURES SHOULD ALSO CLIMB ABOVE NORMAL IN THE 70S MONDAY THROUGH AT LEAST WEDNESDAY WITH LIGHT SOUTHERLY FLOW AHEAD OF A WEAK FRONTAL SYSTEM. WITH TEMPERATURES IN THE 70S AND SOUTHERLY FLOW WILL ALSO LEAVE THUNDER IN. && .AVIATION /DISCUSSION FOR THE 26/18Z TAF ISSUANCE/... ISSUED AT 129 PM EDT FRI APR 26 2013 VFR CONDITIONS EXPECTED FOR DURATION OF TAF PERIOD DESPITE INCREASING MID AND HIGH CLOUDS THROUGH THIS EVENING. CONFIDENCE WAS HIGH ENOUGH TO INSERT MENTION OF VCSH IN THIS TAF ISSUANCE FOR TOMORROW MORNING AT KIND/KHUF/KBMG. WINDS WILL BE SOUTHERLY AT 5 TO 10 KTS. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...50 NEAR TERM...RYAN SHORT TERM...50 LONG TERM....MK AVIATION...TDUD
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1205 PM CDT FRI APR 26 2013 .UPDATE... ISSUED AT 908 AM CDT FRI APR 26 2013 INCREASED POPS TODAY AS FIRST WAVE OF RAIN SHOWERS STEADILY MARCH NORTHEAST INTO THE FORECAST AREA. DRY LOW LEVELS ARE FIGHTING A LOSING BATTLE AND MEASURABLE PRECIPITATION HAS BEEN OBSERVED AS FAR EAST AS FARMINGTON ALREADY. COULD SEE A BREAK ALONG THE I-70 CORRIDOR THIS AFTERNOON BEFORE ROUND NUMBER TWO OVERSPREADS THE AREA IN ASSOCIATION WITH THE MAIN SHORTWAVE CURRENTLY LOCATED OVER COLORADO. CVKING && .SHORT TERM...(THROUGH LATE THIS AFTERNOON) ISSUED AT 353 AM CDT FRI APR 26 2013 THE PRIMARY FCST ISSUE FOR TODAY IS PCPN COVERAGE. EARLY MORNING WATER VAPOR IMAGERY AND RUC 1.5 PVU ANALYSES DEPICTED A COMPACT VORT MAX OVER MN AS WELL AS A SHORTWAVE NEAR THE FOUR CORNERS REGION. A BROAD AREA OF SHRA/TSRA HAS DEVELOPED ACROSS PARTS OF KS/OK/MO/AR IN RESPONSE TO A COMBINATION OF H9 FRONTOGENESIS AND H85-H7 MOISTURE CONVERGENCE FM THE LLJ AHEAD OF THE FOUR CORNERS SHORTWAVE. THIS 40-50KT SWLY LLJ /PER AREA VWP AND PROFILER OBS/ WAS TRANSPORTING MOISTURE INTO THE AREA AND LEADING TO AN INCREASE IN PCPN COVERAGE. ALTHOUGH MODELS GENERALLY SHOW A DECREASE IN THE LLJ THROUGH MID MORNING ACROSS MO/IL...THEY ALSO SHOW PERSISTENT AREAS OF ISENTROPIC ASCENT ALONG THE 295-305K SFCS /ESPECIALLY ACROSS THE SWRN CWA/ ALONG WITH AREAS OF INCREASED FRONTOGENESIS ALOFT. ALTHOUGH THE BEST FORCING FOR LARGE SCALE ASCENT WILL NOT ARRIVE UNTIL LATER TONIGHT AND THE LOW LEVEL AIR MASS WILL INITIALLY BE SOMEWHAT DRY...THE AFOREMENTIONED LIFTING MECHANISMS APPEAR SUFFICIENT TO CONTINUE POPS FOR SCT-INTERMITTENT SHRA TODAY. 42 .LONG TERM...(TONIGHT THROUGH THURSDAY) ISSUED AT 353 AM CDT FRI APR 26 2013 (TONIGHT - SATURDAY) A LARGELY NEUTRAL UPPER LEVEL FLOW WILL EXIST THRU SATURDAY...BUT THIS PERIOD WILL BE MOST MARKED BY A STRONG SHORTWAVE SLOWLY PASSING THRU. THE PROGRESSION OF THIS SYSTEM THRU THE BI-STATE WILL BE SLOW...WITH IT NOT EXPECTED TO PULL AWAY UNTIL LATE SATURDAY NIGHT. UNTIL SUNDAY...LOOK FOR CLOUDY SKIES WITH HI RAIN PROBS...EVEN THOUGH SOME AREAS MAY ONLY RECEIVE A FEW HUNDREDTHS WITH EXPECTED NATURE OF PCPN FOR MUCH OF THIS EVENT TO BE SHOWERY. MAIN AREAS TO KEY ON FOR RAIN TONIGHT WILL BE WHAT SHOULD BE A PERSISTENTLY STRONG REGION OF WAA AND H850-700 FRONTOGENESIS OVER SERN MO AND FAR SRN IL WHICH WILL REPRESENT THE BEST CHANCES FOR MEASURABLE...BUT A MORE BROADSCALE REGION OF MID LEVEL LIFT SHOULD ALSO WORK IN FOR THE REMAINDER OF THE AREA...ESPECIALLY W OF THE MS RIVER FOR ADDITIONAL LIGHT RAIN AMOUNTS. ON SATURDAY THE MEAT OF THE SYSTEM MOVES THRU WITH GENERALLY WEAK YET DEEP LIFT THRU A MOIST COLUMN...AND BUMPED POPS TO LIKELY FOR WIDESPREAD LIGHT RAINFALL AMOUNTS. THIS FINALLY BEGINS TO EXIT SATURDAY NIGHT WITH MOISTURE SLOWLY SCOURING OUT ALTHOUGH COULD SEE SHRA SIMPLY BE REPLACED BY DRIZZLE EARLY SUNDAY MORNING WITH LO CLOUDS BEING THE MOST STUBBORN OF ALL TO LEAVE. THE WARMER MAV MOS IS PREFERRED FOR MINS TONIGHT...WHILE WENT WITH THE COOLER MET MOS FOR MAXES SATURDAY TO PROMOTE A LO DIURNAL SWING WITH WHAT SHOULD BE THICK AND LO CLOUD COVER. AGAIN PREFERRED WARMER MAV MOS FOR SATURDAY NIGHT MINS. (SUNDAY - TUESDAY) UPPER LEVEL LONGWAVE RIDGE WILL BUILD OVER ERN NOAM WHILE A TROF DIGS IN THE W...RESULTING IN A WARM AND DRY PERIOD...WITH TEMPS PUSHING ABOVE AVERAGE FOR A COUPLE OF DAYS AT LEAST. WHILE DID UNDERCUT MOS MAX TEMPS ON SUNDAY DUE TO WHAT SHOULD BE STUBBORN LO CLOUD HANGING AROUND AND FINALLY LEAVING...MONDAY AND TUESDAY ARE EXPECTED TO FEATURE PLENTY OF SUNSHINE AND A DECENT S FLOW WITH RISING H500 HEIGHTS OVERHEAD. FCST H850/H900 TEMPS...IF THEY PAN OUT...WILL RESULT IN 75-80F FOR MONDAY AND AROUND 78-82F FOR TUESDAY. BUILDING RIDGE WILL EFFECTIVELY DEFLECT ANY SYSTEMS TO OUR N AND SHOULD KEEP OUR REGION DRY. (WEDNESDAY - THURSDAY) ALL OF THIS IS SHORT-LIVED...WITH THE UPPER LEVEL ERN NOAM RIDGE TO BREAKDOWN EITHER WEDNESDAY OR THURSDAY DEPENDING ON THE MODEL AND WILL BE ACCOMPANIED BY A STOUT CDFNT BACKED BY A STRONG CANADIAN AIRMASS. THE ECMWF PREFERS A SLOWER TIMING ON THURS WHILE THE GFS FAVORS WEDNESDAY. HAVE STRETCHED POPS FOR WED-THU TO COVER TIMING DIFFS WITH FRONT AND DID NOT HIT THE COLD AIR AS MUCH ON THURSDAY FOR THE SAME REASONS. TES && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1156 AM CDT FRI APR 26 2013 LIGHT RAIN SHOWERS CONTINUE TO DEVELOP ACROSS THE FORECAST AREA EARLY THIS AFTERNOON. CONDITIONS SHOULD REMAIN VFR THROUGH THE AFTERNOON OUTSIDE OF HEAVIER RAIN WHICH IS LOCATED ACROSS THE FAR SOUTHERN PART OF THE CWA. GENERALLY BELIEVE THAT THE MAIN THRUST OF RAIN SHOULD COME THIS EVENING AND INTO THE OVERNIGHT AS MAIN UPPER LEVEL ENERGY PUSH INTO THE REGION. HAVE BROUGHT CEILING DOWN TO MVFR CATEGORY BUT AM NOT SOLD ON IFR CONDITIONS YET...WOULD RATHER TAKE A WAIT AND SEE APPROACH. OTHERWISE...WITH UPPER LEVEL SYSTEM MOVING OVERHEAD ON SATURDAY...COULD SEE SHOWERS AND LOWER CEILINGS LINGER THROUGH THE DAY. SOUTH WIND WILL BECOME EAST. SPECIFICS FOR KSTL... ISOLATED TO SCATTERED LIGHT RAIN SHOWERS WILL CONTINUE THIS AFTERNOON WITH A RAMPING UP OF COVERAGE AND INTENSITY THIS EVENING AS UPPER LEVEL SYSTEM APPROACHES. COULD BE A PERIOD OF IFR CONDITIONS IN HEAVIER RAIN...BUT WILL HAVE TO NOWCAST THIS BASED ON RADAR AS WE GET CLOSER. OTHERWISE...CEILING TO LOWER TO MVFR AND SHOWERS TO CONTINUE INTO SATURDAY WITH UPPER LOW TRACKING OVERHEAD. CVKING && .LSX WATCHES/WARNINGS/ADVISORIES... MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
320 PM CDT FRI APR 26 2013 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 320 PM CDT FRI APR 26 2013 MAIN FOCUS IN THE SHORT TERM WILL CENTER AROUND SLIGHT CHANCES FOR THUNDERSTORMS AND HIGH TEMPERATURES SATURDAY. A QUICK SYNOPTIC ANALYSIS REVEALS MOSTLY ZONAL FLOW ACROSS THE CONUS WITH THE EXCEPTION OF AN OPEN WAVE TROUGH ACROSS THE ROCKIES. AT THE SURFACE...HIGH PRESSURE REMAINED SITUATED ACROSS BOTH COASTS WITH A WEAK LOW PRESSURE SYSTEM ACROSS THE TEXAS PANHANDLE. THE OPEN WAVE BEGAN TO SHIFT JUST SOUTH OF THE PLAINS THIS MORNING...WHICH BROUGHT SHOWERS AND THUNDERSTORMS TO PORTIONS OF KANSAS. SATELLITE IMAGERY REVEALS A THICK CLOUD COVER OVER MUCH OF SOUTHEAST KANSAS AND MISSOURI WITH THINNING CIRRUS DECK ACROSS SOUTHERN NEBRASKA AND IOWA. A SURFACE TROUGH ASSOCIATED WITH THE LOW IN THE PANHANDLE ALSO BEGAN SHIFTING ACROSS THE PLAINS THIS AFTERNOON AS WELL. A STRONG 850 MB JET STREAK ON THE BACKSIDE OF THIS TROUGH ALSO SHIFTED ACROSS NEBRASKA THIS AFTERNOON. COMBINED WITH STRONG MIXING...THIS JET STREAK LED TO A BRIEF PERIOD OF STRONGER WIND GUSTS NEAR 30 MPH AND LOW RH VALUES NEAR 20 PERCENT. THESE CONDITIONS WERE SEEN OVER A FAIRLY SMALL LOCALIZED AREA STRETCHING FROM MCCOOK TO ORD WESTWARD. FOR THE REST OF THE AFTERNOON...SHORT TERM MODELS INDICATE THE WEAKENING OF THE 850 JET STREAK WHICH SHOULD RELAX WINDS AND HELP STEADY RH VALUES. CURRENT THINKING IS WINDS WILL REMAIN MARGINAL AROUND 20 TO 25 MPH FOR THE NEXT FEW HOURS OR SO ESPECIALLY WEST OF A LINE FROM MCCOOK TO KEARNEY TO ORD BEFORE DECREASING BY LATE THIS AFTERNOON AND EARLY EVENING. AS THE SURFACE TROUGH CONTINUES TO SHIFT EASTWARD...MODELS ALSO HINT AT THE POSSIBILITY FOR SOME ADDITIONAL SHOWER DEVELOPMENT NEAR THE BOUNDARY...MAINLY SOUTH OF LINE FROM CAMBRIDGE TO FULLERTON. WITH INSTABILITY PARAMETERS NEAR 300 TO 500 J/KG KEPT MENTION OF THUNDER IN THE FORECAST FROM 0Z TO 3Z WITH DIMINISHING INSTABILITY THEREAFTER LIKELY DECREASING THUNDER THREAT. AT THIS POINT...REALLY THINKING ISOLATED LIGHT SHOWERS WITH MAYBE A RUMBLE OF THUNDER OR TWO. HRRR AND 4 KM WRF MODEL ALSO IN AGREEMENT WITH THIS THINKING. HEADING INTO SATURDAY...THE UPPER LEVEL RIDGE SLOWLY BEGINS TO BUILD EASTWARD INTO THE PLAINS BEHIND THE TROUGH AXIS. WARMER 850 MB TEMPERATURES WILL ALSO SLIDE INTO THE REGION. SHOULD BE A FAIRLY NICE AND BRIGHT DAY WITH SURFACE HIGH PRESSURE OVER THE FORECAST AREA...LIGHT NORTH WINDS AND TEMPERATURES RANGING IN THE 70S. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 320 PM CDT FRI APR 26 2013 GUIDANCE SUGGESTS AN OVERALL LACK IN KINEMATIC FORCING SHOULD PROVIDE DRY CONDITIONS TO OUR AREA SUNDAY INTO SUNDAY EVENING. DURING THE EARLY MORNING HOURS ON MONDAY HOWEVER...THERE ARE INDICATIONS OF A WEAK MID LEVEL PERTURBATION MOVING OVER THE REGION WITH PERHAPS ENOUGH OMEGA FOR PRECIPITATION PRODUCTION. THAT BEING SAID FORECAST PROXIMITY SOUNDINGS FROM ACROSS OUR AREA...PER THE NAM AND OPERATIONAL GFS...SUGGEST THE LOWER TROPOSPHERE WILL REMAIN FAIRLY DRY AND AS A RESULT...IT IS CURRENTLY BELIEVED NOTHING MORE THAN A FEW SPRINKLES WILL BE REALIZED ACROSS THE AREA EARLY MONDAY MORNING. GIVEN ALL THIS...WENT AHEAD WITH A SPRINKLE MENTION IN THE FORECAST...PRIMARILY FOR LOCATIONS ACROSS OUR NORTH/NORTHWEST WHERE OMEGA IS EXPECTED TO BE STRONGEST. DRY CONDITIONS ARE THEN FORECAST INTO THE DAY MONDAY AND MONDAY NIGHT AS A LACK IN KINEMATIC FORCING OVERTAKES THE AREA ONCE AGAIN. ANOTHER CHANCE AT PRECIPITATION IS THEN FORECAST TUESDAY THROUGH WEDNESDAY NIGHT AS A MID LEVEL SHORT WAVE IS EXPECTED TO MOVE OVER PORTIONS OF THE NORTHERN AND CENTRAL PLAINS. AN ASSOCIATED SURFACE LOW IS ALSO EXPECTED TO MOVE ACROSS PORTIONS OF THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY WITH A LOW LEVEL BAROCLINIC ZONE FORECAST TO MOVE ACROSS OUR CWA AT SOME POINT DURING THE DAY TUESDAY. TIMING THE PASSAGE OF THE LOW LEVEL BAROCLINIC ZONE IS DIFFICULT GIVEN THIS SYSTEM IS STILL 4 DAYS OUT...BUT AT THIS TIME IT APPEARS LOCATIONS AHEAD OF THE BAROCLINIC ZONE WILL OBSERVE A SURFACE DEWPOINT IN THE MID TO UPPER 50S. THIS LOW LEVEL MOISTURE...WORKING IN CONCERT WITH INCREASING MID LEVEL LAPSE RATES WITH THE APPROACH OF THE MID LEVEL SHORT WAVE...COULD POTENTIALLY PROMOTE 0-1KM MLCAPE VALUES ANYWHERE BETWEEN 500J/KG AND 1500J/KG. INCREASING MID TO UPPER LEVEL FLOW IS ALSO EXPECTED TO INCREASE DEEP LAYER BULK SHEAR TO BETWEEN 30KTS AND 40KTS. GIVEN ALL THIS...IT CERTAINLY APPEARS SEVERE WEATHER COULD BE REALIZED AT LOCATIONS STILL OUT AHEAD OF THE LOW LEVEL BAROCLINIC ZONE TUESDAY AFTERNOON AND EVENING. AT THIS TIME IT ALSO APPEARS THE SOUTHEASTERN ONE-THIRD OF OUR CWA STANDS THE BEST CHANCE AT OBSERVING SEVERE WEATHER AND AS A RESULT...WILL CONTINUE SUCH WORDING IN THE HWO. ANY SEVERE WEATHER THAT IS REALIZED ACROSS THE AREA TUESDAY AFTERNOON AND EVENING SHOULD QUICKLY DEPART TO THE EAST/SOUTHEAST TUESDAY NIGHT AS THE LOW LEVEL BAROCLINIC ZONE DOES THE SAME. DECREASING LOW LEVEL MOISTURE SHOULD ALLOW FOR DECREASING POTENTIAL INSTABILITY BUT WITH INCREASING OMEGA DUE TO THE APPROACHING MID LEVEL SHORT WAVE...CHANCES FOR PRECIPITATION CONTINUE IN THE FORECAST FOR MOST ALL OF OUR CWA TUESDAY NIGHT INTO WEDNESDAY...AND LINGERING ACROSS OUR EAST/SOUTHEAST WEDNESDAY NIGHT. DRY CONDITIONS ARE THEN FORECAST THURSDAY ONWARD. A VERY WARM LOW LEVEL AIRMASS WILL CONTINUE TO PROMOTE AN AFTERNOON HIGH TEMPERATURE IN THE 70S TO LOW 80S SUNDAY THROUGH TUESDAY. THE PASSAGE OF THE LOW LEVEL BAROCLINIC ZONE ON TUESDAY HOWEVER WILL THEN BRING AN END TO THE WARM WEATHER...WITH A COOLER LOW LEVEL AIRMASS LIKELY PROMOTING AN AFTERNOON HIGH TEMPERATURE IN THE 50S AND 60S TO FINISH OUT THE FORECAST PERIOD. AN OVERNIGHT LOW TEMPERATURE IN THE 40S AND 50S IS EXPECTED SUNDAY NIGHT THROUGH TUESDAY NIGHT...WITH LOWS RANGING FROM THE MID 30S TO THE LOW 40S WEDNESDAY NIGHT ONWARD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1240 PM CDT FRI APR 26 2013 THE MAIN CONCERN FOR THIS TAF PERIOD WILL FOCUS ON WINDS AND SLIGHT CHANCES FOR SHOWERS AND POSSIBLY A RUMBLE OF THUNDER OR TWO LATE THIS AFTERNOON. NOTED OBSERVATIONS AND MODELS SUGGEST A SMALL 850 MB JET STREAK SHIFTING EASTWARD ACROSS THE PLAINS. THUS LOCATIONS ROUGHLY FROM NORTH PLATTE TO LEXINGTON HAVE SEEN WIND GUSTS NEAR 20 TO 25 KTS THIS AFTERNOON. ALTHOUGH...THIS AXIS APPEARS TO BE SHIFTING EASTWARD MODELS SUGGEST THAT IT SHOULD WEAKEN THROUGHOUT THE AFTERNOON. AS A RESULT...KEPT ANY MENTION OF WIND GUST OUT OF TAF...BUT THE POSSIBILITY FOR A FEW GUSTS TO NEAR OR AROUND 15 KT STILL LINGERS. MODELS ALSO CONTINUE TO HINT AT THE POSSIBILITY FOR SCATTERED SCATTERED AT OR AROUND THE TERMINAL LATER THIS AFTERNOON AND EVENING...MAINLY AFTER 0Z. INSTABILITY PARAMETERS SUGGEST THAT A RUMBLE OF THUNDER OR TWO COULD BE POSSIBLE. HOWEVER...WIDESPREAD SHOWERS ARE CERTAINLY NOT EXPECTED AND CONFIDENCE IS LOW ENOUGH TO KEEP MENTION OUT OF TAF FOR NOW. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...SALTZMAN LONG TERM...BRYANT AVIATION...SALTZMAN
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
441 PM EDT FRI APR 26 2013 .SYNOPSIS... AN INCREASINGLY MOIST WEDGE OF COOLER AIR WILL OVERSPREAD THE REGION THIS WEEKEND AS WEAK LOW PRESSURE MOVES ACROSS THE TENNESSEE VALLEY ALONG A STALLED COLD FRONT. THE FRONT WILL SLOWLY DISSIPATE AND THE COOL AIR WEDGE WILL GRADUALLY WEAKEN INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... 430 PM UPDATE...FCST IS IN GOOD SHAPE. MADE MINOR TWEAKS TO TEMPS AND TD/S. CLOUD COVER WAS ADJ INCORPORATING THE LATEST VIS INDICATING BKN/OVC ACU/CI OVER THE WRN NC MTNS. WINDS WERE BUMPED UP A LITTLE OVER THE MTNS AND BLENDED WITH THE 20Z RAP GUIDANCE. AS OF 230 PM...LATEST SATELLITE IMAGES AND VIEW OUT OF THE WINDOW INDICATE THAT THIN CIRRUS HAS STARTED TO SWEEP ACROSS THE FORECAST AREA...ARRIVING FROM THE WEST. WITH THE ARRIVAL OF THE HIGH CLOUDS...TEMPERATURES ACROSS THE REGION WILL LIKELY PEAK OVER THE NEXT HOUR...ESPECIALLY ACROSS THE FOOTHILL AREAS. OVERNIGHT...1030MB HIGH WILL BECOME CENTERED OVER NEW ENGLAND...RIDGING SW ACROSS THE CWA. TO THE WEST...LOW PRESSURE IS EXPECTED TO TRACK NE...REACHING THE ARKLATX BY 12Z SAT. THE ASSOCIATED WARM FRONT WILL LIKELY RUN ACROSS TN INTO WESTERN NC BY DAYBREAK SAT. SHORT RANGE MODELS INDICATE THAT A MID LEVEL S/W WILL RIPPLE ACROSS THE MID MISSISSIPPI RIVER VALLEY THIS EVENING...REACHING KY/TN LATE TONIGHT. THE COMBINATION OF THE MID LEVEL FORCING...WARM FRONT...AND INCREASING MOISTURE SHOULD SUPPORT AN EXPANDING AREA OF RAIN WEST OF THE SOUTHERN APPALACHIANS OVERNIGHT. A BAND OF SHRA IS EXPECTED TO DEVELOP NORTH OF THE SFC WARM FRONT LATE TONIGHT...SLIDING ACROSS THE WESTERN AND CENTRAL MOUNTAINS AND NRN SC UPSTATE DURING AROUND SUNRISE. I WILL INCREASE POPS TO CHC TO LIKELY ACROSS THE NC MTNS AND ADJACENT FOOTHILLS BY 12Z SAT. ON SATURDAY...THE CENTER OF THE LOW PRESSURE IS FORECAST TO TRACK ACROSS THE MID MISSISSIPPI RIVER VALLEY BY 0Z SUN. AS THE LOW TRACKS NE...THE ASSOCIATED WARM FRONT WILL LIFT NORTH...PIVOTING ACROSS THE WESTERN NC MTNS DURING THE DAY. I WILL FAVOR THE MTNS AND FOOTHILLS FOR CATE AND LIKELY POPS. COVERAGE SHOULD PUSH EAST DURING THE MID AND LATE AFTERNOON ACROSS THE I-77 CORRIDOR. QPF RANGES FROM NEAR THREE-QUARTERS OF AN INCH ACROSS THE WESTERN NC MTNS TO LESS THAN A TENTH OF AN INCH EAST OF I-77. BASED ON THE TIMING OF THE PRECIP...I WILL KEEP HIGH TEMPS LIMITED ACROSS THE MTNS TO THE 50S...POSSIBLY REACHING THE U60S ACROSS THE EASTERN PIEDMONT. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... AS OF 230 PM FRI...THE UPSTREAM H5 LOW CENTER WILL SLOWLY OPEN UP AND LIFT NE ACROSS IL/IN SAT NIGHT THROUGH SUNDAY. MODEL TIME HEIGHTS AHEAD OF THIS FEATURE SHOW DEEP MOISTURE ARRIVING OVER THE AREA...WITH UPPER DIVERGENCE DEVELOPING S OF A JETLET THROUGH THE MID ATLANTIC AREA...AS WELL AS IMPROVING SRLY UPSLOPE FLOW INTO THE MTNS AND UPGLIDE OVER AN IN SITU SFC CAD LAYER. THE CAD WILL ONLY GRADUALLY SHALLOW OUT THROUGH SUNDAY GIVEN THE DEEP LAYER SRLY FLOW. ANY INSTABILITY SUNDAY AFTN SHOULD BE CONFINED TO MAINLY THE SRN PIEDMONT. THE BEST LOW LEVEL UPGLIDE WILL BE CENTERED OVER THE FORECAST AREA MIDDAY SUNDAY...WITH A SECONDARY SURGE OF MOISTURE/FORCING SUNDAY NIGHT AS A COLD FRONT APPROACHES FROM THE W. QPF WILL BE THE MAIN FORECAST ISSUE DURING THIS PERIOD...WITH THE SRLY UPSLOPE FLOW LIKELY PRODUCING A LOCAL MAXIMA ALONG S/SE UPSLOPE PRONE AREAS OF THE SRN APPALACHIANS. THE GFS QPF IS A HIGH END OUTLIER WITH STORM TOTALS OF 4 TO 5 INCHES IN THE SRN NC MTNS...DUE MAINLY TO A WAVE RIDING UP THE SRN APPALACHIANS SUNDAY NIGHT. THE OTHER MODELS/ENSEMBLES FEATURE A CONSENSUS MORE IN THE 3.0 TO 3.5 RANGE IN SRLY UPSLOPE AREAS...IN GOOD AGREEMENT WITH WPC. PRECIPITABLE WATER ANOMALIES ARE FORECAST TO BE 1 TO 2 STANDARD DEVIATIONS ABOVE NORMAL...AND ANTECEDENT CONDITIONS ARE FAIRLY DRY. ALL THINGS CONSIDERED...WILL FEATURE AN HWO MENTION OF ISOLATED HYDRO PROBLEMS LATE THIS WEEKEND. DEEPER MOISTURE WILL GRADUALLY DIMINISH FROM THE WEST ON MONDAY AS THE UPPER SUPPORT LIFTS AWAY NORTH OF THE AREA...BUT THERE WILL BE PLENTY OF LINGERING SFC TO 850 MB MOISTURE AS THE FRONT WASHES OUT AND THE LOW LEVEL FLOW VEERS MORE SOUTHWESTERLY. TEMPS WILL REMAIN COOL OVER THE NW NC PIEDMONT MONDAY...BUT WITH GREATER INSTABILITY DEVELOPING BACK TO THE SW. WILL FEATURE SHOTGUN CHANCE POPS ON MAINLY A DIURNAL SCHEDULE FOR SHOWERS AND THUNDERSTORMS MONDAY...WANING TO SCHC MONDAY NIGHT. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 110 PM FRIDAY...WILL CONTINUE TO GIVE PROPS TO THE 26/00 UTC OP ECMWF WHICH LINGERS UPPER LEVEL WEAKNESS ATOP THE CWFA THROUGH TUESDAY. BASED ON THIS...INHERITED SHOTGUN CHANCE POP WILL REMAIN WITH MAX TEMPS CLOSE TO THE LATE APRIL CLIMO. THE LATEST MEDIUM RANGE MODEL MASS FIELDS AND ASSOCIATED RESPONSE ARE NOT TOO TERRIBLY DIFFERENT FOR WEDNESDAY...PROGGING AN INCREASE IN ATLANTIC FETCH AROUND NEW ENGLAND HIPRES...LEADING TO ONGOING DECENT PCPN CHANCES. AN INCREASINGLY TRICKY FCST LOOKS TO BE SHAPING UP FOR LATE WEEK AS DIGGING MID-CONUS L/WV TROUGH SHOULD NUDGE POTENTIALLY WAVY BAROCLINIC ZONE INTO THE SOUTHERN APPALACHIANS WHILE SOUTHERN STREAM ENERGY IS PROGGED TO SPIN UP GULF LOW PRESSURE. ON THE 26/00 UTC ECMWF...THE CWFA IS POSITIONED BETWEEN THE MAIN RESPONSE AREAS OF THESE TWO FEATURES...WHILE THE NEW 26/12 UTC OP GFS HAS US WELL WITHIN THE DEEP FORCING AND MOISTURE. AT THIS POINT...THE BEST COURSE OF ACTION IS TO STICK CLOSE TO THE WPC FCST OF A SOLID MID CHANCE POP AND SLIGHTLY BELOW NORMAL MAX TEMPERATURES. GIVEN THE MODEL DIFFERENCES WITH RESPECT TO JUST HOW THE DYNAMIC PATTERN WILL EVOLVE BY NEXT FRIDAY...FCST CONFIDENCE IS BELOW NORMAL AND PLAN ON SIMPLY GOING WITH THE WPC FCST OF SOLID MID-CHANCE POP AND COOLER THAN PERSISTENCE. && .AVIATION /21Z FRIDAY THROUGH WEDNESDAY/... AT KCLT...HIGH CONFIDENCE VFR FORECAST THROUGH THE TAF PERIOD. CONDITIONS WILL BEGIN CLEAR...WITH CIRRUS ARRIVING FROM THE WEST BY LATE AFTERNOON. HIGH PRESSURE CENTERED OVER NEW ENGLAND WILL RIDGE SW ACROSS THE WESTERN CAROLINAS OVERNIGHT. NEAR TERM MODEL INDICATED THAT A WARM FRONT WILL DEVELOP ACROSS TN/W NC BY 12Z SAT. THE FRONT WILL PRESS NORTHWARD THROUGH THE DAY...BUT REMAINING SOUTH OF THE TERMINAL BEFORE 18Z. FORECAST SOUNDINGS INDICATE THAT MOISTURE SHOULD INCREASE FROM THE TOP DOWN...WITH BKN060 EXPECTED DURING THE FINAL HOURS OF THE TAF. WINDS SHOULD BECOME LIGHT FROM THE SSW TONIGHT AND SAT. ELSEWHERE...WESTERN CAROLINA TERMINALS WILL REMAIN VFR THROUGH THIS EVENING. SKC EARLY THIS AFTERNOON WILL BECOME FEW TO SCT WITH CIRRUS BY LATE THIS AFTERNOON. FORECAST SOUNDINGS INDICATE THAT MOISTURE WILL INCREASE FROM THE TOP DOWN AS A WARM FRONT APPROACHES LATE TONIGHT. KAVL SHOULD SEE CLOUD BASES LOWER TO MVFR AROUND SUNRISE...REMAINING MVFR THROUGH THE REMAINDER OF THE TAF PERIOD. BEGINNING AROUND 12Z SAT...A WARM FRONT WILL REACH TN/W NC AS A MID LEVEL DISTURBANCE RIPPLES EASTWARD OVER H5 RIDGING. THE COMBINATION OF LOW AND MID FORCING SHOULD SUPPORT AN EXPANDING AREA OF SHRA ACROSS THE REGION SAT MORNING. KAVL WILL SEE THE GREATEST CHC...WITH LIKELY POPS AFTER 15Z SAT. WINDS SHOULD BECOME LIGHT FROM THE SSW TONIGHT AND SAT. OUTLOOK...A WEDGE OF COLD AIR THAT WILL AFFECT THE REGION SUNDAY AND MONDAY...ALONG WITH THE POSSIBILITY OF PERIODIC RESTRICTIONS. CONFIDENCE TABLE... 20-02Z 02-08Z 08-14Z 14-20Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 92% MED 74% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...CSH NEAR TERM...NED/SBK SHORT TERM...HG LONG TERM...CSH AVIATION...NED
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
606 PM CDT FRI APR 26 2013 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 259 PM CDT FRI APR 26 2013 VERY LITTLE OF SIGNIFICANCE TONIGHT AND SATURDAY ACROSS THE AREA AS SYSTEMS DIVERT AROUND THE REGION. FRONTAL BOUNDARY HAS COMPLETELY CLEARED THE FAR SOUTHEAST CWA AT MID AFTERNOON...WITH VERY MIXY LOWER ATMOSPHERE DRIVING A DECENT NORTHWEST TO NORTHEAST WIND ACROSS THE AREA. WINDS WILL DECOUPLE FAIRLY QUICKLY AS SUNSET...WITH WEAK SURFACE RIDGE CENTERED OVER THE AREA OVERNIGHT. VERY DRY AIRMASS OVER THE WESTERN HALF...SO EXPECT THAT WILL BE FAIRLY EFFICIENT IN COOLING THIS EVENING AND IN THE OVERNIGHT WITH THE WEAK FLOW. NOT EXPECTING ANY SIGNIFICANT FOG POTENTIAL...BUT MAY GET SOME 4-6SM DEVELOPMENT IN SHALLOW AREAS THROUGH THE MID CWA. FRONTAL BOUNDARY WILL WASH OUT TO THE SOUTH...WITH SOUTHERLY FLOW GRADUALLY BECOMING ESTABLISHED...STRONGEST ACROSS THE WEST. MODELS HAVE REPEATEDLY BEEN ABOUT 2C TOO COOL ON 925 HPA TEMPS FOR THE NEXT DAY...AND RAP HAS PROVIDED A MUCH BETTER FORECAST ONCE IT HAS FALLEN INTO THE RANGE. THEREFORE...ACTUALLY RAISED TEMPERATURES SOMEWHAT HIGHER THAN GUIDANCE...BUT ONLY A COUPLE DEGREES AS WILL BE A MORE STABLE WARM ADVECTIVE PROFILE INSTEAD OF THE WEAK COLD ADVECTION TODAY. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 259 PM CDT FRI APR 26 2013 SATURDAY NIGHT WILL SEE A DECENT SOUTHERLY GRADIENT THROUGH THE NIGHT WHICH WILL KEEP MILD TEMPERATURES IN PLACE. THIS WILL KEEP LOWS ABOVE NORMAL AND MAINLY IN THE UPPER 40S TO AROUND 50. COULD ACTUALLY SEE THEM A LITTLE WARMER OF THE GRADIENT REMAINS STRONG ENOUGH. A COLD FRONT WILL SWING INTO THE AREA ON SUNDAY WHICH MAY SPARK A FEW SHOWERS AND THUNDERSTORMS OVER THE EASTERN CWA DURING THE DAY AND INTO THE EVENING. UPPER LEVEL SUPPORT WILL ALSO BRING A CHANCE FOR SHOWERS INTO THE WESTERN AND SOUTHERN CWA DURING THE NIGHT. AHEAD OF THIS FRONT TEMPERATURES WILL CLIMB WELL ABOVE NORMAL AND MUCH OF THE AREA WILL CLIMB INTO THE UPPER 70S TO LOWER 80S. SUNDAY NIGHT INTO MONDAY WILL BE A MILD PERIOD WITH THE FRONT SETTLING IN AND COOLER TEMPERATURES. THE BETTER CHANCE FOR SHOWERS WILL BE IN THE SOUTHERN CWA. INSTABILITY MARGINAL SO ONLY A MINOR THREAT FOR THUNDERSTORMS...THE BETTER CHANCE WILL BE SUNDAY AFTERNOON OVER THE EASTERN CWA. WHILE MONDAY WILL BE COOLER STILL ANTICIPATING UPPER 60S TO LOWER 70S. SOME UNFORTUNATE BIG CHANGES COMING IN THE EXTENDED AS A LARGE TROUGH OF LOW PRESSURE GRADUALLY DIGS ACROSS THE NORTHERN AND CENTRAL PLAINS. THIS WILL BRING AN END TO THE WARM STRETCH WITH BELOW NORMAL TEMPERATURES AGAIN BLANKETING THE REGION FOR THE REMAINDER OF THE WEEK. THE GFS COMES IN QUITE A BIT DEEPER WITH THE CUT OFF LOW THAT DEVELOPS...DROPPING IT SOUTH INTO KENTUCKY BY THE WEEKEND WHILE THE ECMWF CUTS THIS LOW OFF IN NORTHERN WISCONSIN...ALTHOUGH THE NEW 12Z ECMWF NOW CUTS THIS LOW OFF IN NEBRASKA. SO...THE MAIN STORY HERE IS A VERY UNPREDICTABLE CUT OFF LOW BUT COLDER TEMPERATURES. THERE DOES APPEAR TO BE SOME DECENT UPPER LEVEL SUPPORT THAT DROPS SOUTH MID WEEK AND WILL HAVE SOME POPS IN TO COVER THIS OTHERWISE AT THIS TIME NOT LOOKING LIKE ANY MAJOR SYSTEMS. CONFIDENCE AFTER WEDNESDAY LOW. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 605 PM CDT FRI APR 26 2013 VFR THROUGH 00Z SUNDAY. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM...CHAPMAN LONG TERM...08 AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
314 PM CDT FRI APR 26 2013 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 259 PM CDT FRI APR 26 2013 VERY LITTLE OF SIGNIFICANCE TONIGHT AND SATURDAY ACROSS THE AREA AS SYSTEMS DIVERT AROUND THE REGION. FRONTAL BOUNDARY HAS COMPLETELY CLEARED THE FAR SOUTHEAST CWA AT MID AFTERNOON...WITH VERY MIXY LOWER ATMOSPHERE DRIVING A DECENT NORTHWEST TO NORTHEAST WIND ACROSS THE AREA. WINDS WILL DECOUPLE FAIRLY QUICKLY AS SUNSET...WITH WEAK SURFACE RIDGE CENTERED OVER THE AREA OVERNIGHT. VERY DRY AIRMASS OVER THE WESTERN HALF...SO EXPECT THAT WILL BE FAIRLY EFFICIENT IN COOLING THIS EVENING AND IN THE OVERNIGHT WITH THE WEAK FLOW. NOT EXPECTING ANY SIGNIFICANT FOG POTENTIAL...BUT MAY GET SOME 4-6SM DEVELOPMENT IN SHALLOW AREAS THROUGH THE MID CWA. FRONTAL BOUNDARY WILL WASH OUT TO THE SOUTH...WITH SOUTHERLY FLOW GRADUALLY BECOMING ESTABLISHED...STRONGEST ACROSS THE WEST. MODELS HAVE REPEATEDLY BEEN ABOUT 2C TOO COOL ON 925 HPA TEMPS FOR THE NEXT DAY...AND RAP HAS PROVIDED A MUCH BETTER FORECAST ONCE IT HAS FALLEN INTO THE RANGE. THEREFORE...ACTUALLY RAISED TEMPERATURES SOMEWHAT HIGHER THAN GUIDANCE...BUT ONLY A COUPLE DEGREES AS WILL BE A MORE STABLE WARM ADVECTIVE PROFILE INSTEAD OF THE WEAK COLD ADVECTION TODAY. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 259 PM CDT FRI APR 26 2013 SATURDAY NIGHT WILL SEE A DECENT SOUTHERLY GRADIENT THROUGH THE NIGHT WHICH WILL KEEP MILD TEMPERATURES IN PLACE. THIS WILL KEEP LOWS ABOVE NORMAL AND MAINLY IN THE UPPER 40S TO AROUND 50. COULD ACTUALLY SEE THEM A LITTLE WARMER OF THE GRADIENT REMAINS STRONG ENOUGH. A COLD FRONT WILL SWING INTO THE AREA ON SUNDAY WHICH MAY SPARK A FEW SHOWERS AND THUNDERSTORMS OVER THE EASTERN CWA DURING THE DAY AND INTO THE EVENING. UPPER LEVEL SUPPORT WILL ALSO BRING A CHANCE FOR SHOWERS INTO THE WESTERN AND SOUTHERN CWA DURING THE NIGHT. AHEAD OF THIS FRONT TEMPERATURES WILL CLIMB WELL ABOVE NORMAL AND MUCH OF THE AREA WILL CLIMB INTO THE UPPER 70S TO LOWER 80S. SUNDAY NIGHT INTO MONDAY WILL BE A MILD PERIOD WITH THE FRONT SETTLING IN AND COOLER TEMPERATURES. THE BETTER CHANCE FOR SHOWERS WILL BE IN THE SOUTHERN CWA. INSTABILITY MARGINAL SO ONLY A MINOR THREAT FOR THUNDERSTORMS...THE BETTER CHANCE WILL BE SUNDAY AFTERNOON OVER THE EASTERN CWA. WHILE MONDAY WILL BE COOLER STILL ANTICIPATING UPPER 60S TO LOWER 70S. SOME UNFORTUNATE BIG CHANGES COMING IN THE EXTENDED AS A LARGE TROUGH OF LOW PRESSURE GRADUALLY DIGS ACROSS THE NORTHERN AND CENTRAL PLAINS. THIS WILL BRING AN END TO THE WARM STRETCH WITH BELOW NORMAL TEMPERATURES AGAIN BLANKETING THE REGION FOR THE REMAINDER OF THE WEEK. THE GFS COMES IN QUITE A BIT DEEPER WITH THE CUT OFF LOW THAT DEVELOPS...DROPPING IT SOUTH INTO KENTUCKY BY THE WEEKEND WHILE THE ECMWF CUTS THIS LOW OFF IN NORTHERN WISCONSIN...ALTHOUGH THE NEW 12Z ECMWF NOW CUTS THIS LOW OFF IN NEBRASKA. SO...THE MAIN STORY HERE IS A VERY UNPREDICTABLE CUT OFF LOW BUT COLDER TEMPERATURES. THERE DOES APPEAR TO BE SOME DECENT UPPER LEVEL SUPPORT THAT DROPS SOUTH MID WEEK AND WILL HAVE SOME POPS IN TO COVER THIS OTHERWISE AT THIS TIME NOT LOOKING LIKE ANY MAJOR SYSTEMS. CONFIDENCE AFTER WEDNESDAY LOW. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1230 PM CDT FRI APR 26 2013 VFR CONDITIONS WILL PREVAIL THROUGH 18Z SAT. SOME MVFR CONDITIONS WILL BE POSSIBLE IN FOG FOR KHON AND KFSD LATE NIGHT/EARLY MORNING WITH LIGHT FLOW. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM...CHAPMAN LONG TERM...08 AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
545 PM CDT FRI APR 26 2013 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 345 PM CDT FRI APR 26 2013 AT 3 PM...A WEAK COLD FRONT WAS LOCATED JUST NORTH OF THE FORECAST AREA FROM DULUTH SOUTHEAST THROUGH THE TWIN CITIES TO SIOUX CITY IOWA. OTHER THAN A FEW CLOUDS AND A WIND SHIFT THERE WAS NO SENSIBLE WEATHER ASSOCIATED WITH THIS FRONT. MEANWHILE FURTHER SOUTH ACROSS NORTHEAST IOWA...AND SOUTHWEST AND CENTRAL WISCONSIN... THERE WAS A 850 TO 700 MB THERMAL TROUGH. THE COMBINATION OF ML CAPES RUNNING AROUND 200 J/KG AND VERY STEEP 900 TO 800 MB LAPSE RATES HAVE RESULTED IN SOME INSTABILITY CLOUDS DEVELOPING ACROSS THIS AREA. THE NMM AND SPC WRF GENERATE A LINE OF SHOWERS IN THIS REGION FROM LATE THIS AFTERNOON INTO TONIGHT. THESE MODELS ARE ABOUT 10F TOO HIGH ON THEIR SURFACE DEW POINTS. MEANWHILE THE ARW WHICH HAS A BETTER HANDLE OF THE SURFACE DEW POINTS SHOWS NO PRECIPITATION AT ALL. WITH THE LATEST RAP SOUNDINGS CONTINUING TO SHOW A VERY SHALLOW MOISTURE LAYER AROUND 800 MB...TRENDED THE FORECAST TOWARD THE ARW FOR TONIGHT. ON SATURDAY...THE 26.12Z AND 26.18Z MODELS ARE IN VERY GOOD AGREEMENT THAT THE COLD FRONT WILL MOVE NORTH AS A WARM FRONT INITIALLY DURING THE MORNING...AND THEN QUICKLY WASHES IT OUT BY THE AFTERNOON. THE NAM/WRF GENERATES 100 TO 200 J/KG OF ML CAPE DURING THE AFTERNOON ALONG AND NORTH OF THE INTERSTATE 90 CORRIDOR. MEANWHILE THE GFS SHOWS VERY LITTLE INSTABILITY AT ALL. THE NAM/WRF LOOKS TOO HIGH ON ITS SURFACE DEW POINTS...SO PREFER THE MORE STABLE GFS. IN ADDITION...THERE IS NO SURFACE TO 850 MB MOISTURE TRANSPORT ANYWHERE IN THE FORECAST AREA. DUE TO THIS...KEPT THE FORECAST DRY. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 345 PM CDT FRI APR 26 2013 ON SUNDAY AFTERNOON...THE 26.12Z GFS SLOWED UP ITS MOVEMENT OF THE PRECIPITATION INTO SOUTHEAST MINNESOTA...AND IN WEST CENTRAL AND NORTH CENTRAL WISCONSIN. THIS IS MORE IN AGREEMENT WITH THE GEM AND ECMWF....THEREFORE...REMOVED THE PRECIPITATION CHANCES FOR THIS TIME PERIOD. FROM SUNDAY NIGHT INTO MONDAY...THE MODELS CONTINUE TO STRUGGLE WITH A COLD FRONT MOVING INTO THE REGION AND THEN MOVING BACK NORTH AS A WARM FRONT. DUE TO THESE UNCERTAINTIES...JUST WENT WITH THE CONSALL PRECIPITATION CHANCES. WITH BOTH THE 0-3 KM AND 0-6 KM SHEAR LESS THAN 30 KNOTS...NOT OVERLY CONCERNED ABOUT ANY SEVERE WEATHER AT THIS TIME. FROM TUESDAY INTO TUESDAY NIGHT...THE MODELS CONTINUE TO STRUGGLE WITH THE SPEED OF A STRONG COLD FRONT MOVING THROUGH THE REGION. ML CAPES AHEAD OF THIS CLIMB INTO THE 250 TO 750 J/KG RANGE. BOTH THE 0-3 KM AND 0-6 KM SHEAR IS FAVORABLE FOR SEVERE WEATHER. HOWEVER THERE IS A WARM LAYER BETWEEN 800 AND 700 MB WHICH MAY CAP OFF ANY PRECIPITATION PRIOR TO THE FRONTAL PASSAGE. IN THE WAKE OF THIS FRONT...TEMPERATURES WILL BE MUCH COLDER FROM WEDNESDAY THROUGH FRIDAY. THE LATEST ECMWF SUGGEST HIGHS ONLY IN THE 30S AND 40S. THE GFS IS A SLIGHTLY A BIT HIGHER. SINCE THE MODELS HAVE BEEN SO INCONSISTENT WITH THIS SYSTEM OVER THE PAST COUPLE OF DAYS...JUST STAYED WITH THE ALL BLEND FOR NOW. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 545 PM CDT FRI APR 26 2013 VFR CONDITIONS WITH LIGHTER WINDS ARE EXPECTED FOR THE NEXT 24 HOURS AS A TROUGH OF LOW PRESSURE CURRENTLY JUST WEST OF KRST WEAKENS. THERE IS A STREAM OF MOISTURE AHEAD OF THIS TROUGH...RESULTING IN VFR CUMULUS FOR THIS EVENING AND SATURDAY AFTERNOON. LOSS OF DIURNAL HEATING AND WEAKENING PRESSURE GRADIENT OVER THE TAF SITES WILL HELP WINDS DIMINISH BY 02Z WITH SPEEDS LESS THAN 10 KT EXPECTED THROUGH SATURDAY. ONE CONCERN FROM VARIOUS MODELS IS SOME MVFR OR EVEN IFR BR DEVELOPMENT BETWEEN 09-13Z...DUE TO THE DIMINISHING WIND. IN ADDITION...DEWPOINTS ARE INCREASING NOW WITH LOSS OF HEATING...WHICH IS A POSITIVE FOR FOG FORMATION. HOWEVER...HAVE CONTINUED TO KEEP THE BR MENTION OUT OF THE TAFS FOR NOW GIVEN THAT SOME WIND LOOKS TO PERSIST. && .HYDROLOGY... ISSUED AT 345 PM CDT FRI APR 26 2013 TRIBUTARY STREAMS CONTINUE TO FALL FOR THE MOST PART. HIGH WATER CONTINUES ALONG THE BLACK AND TREMPEALEAU RIVERS...WITH THE BLACK STILL SEEING SOME IMPACTS FROM MELTING SNOW UP IN THE HEADWATER AREAS OF CLARK/TAYLOR COUNTIES. EXPECT TO SEE SOME ADDITIONAL RISES ALONG THE BLACK IN THE COMING DAYS DUE TO THE WARMING TEMPERATURES. FOR THE MISSISSIPPI RIVER...IT LOOKS TO CONTINUE RISING SLOWLY ALL THE WAY INTO THE SECOND WEEK OF MAY. HOW HIGH IT GETS WILL DEPEND GREATLY ON HOW MUCH RUNOFF MOVES DOWNSTREAM FROM THE SNOW COVERED AREAS OF CENTRAL/NORTHERN MN...AND NORTHWEST WI. THE LATEST FORECASTS ATTEMPT TO TAKE THIS SNOWMELT RUNOFF INTO ACCOUNT...BUT MODIFICATIONS TO THE FORECAST ARE LIKELY. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...AJ HYDROLOGY...WELVAERT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
346 PM CDT FRI APR 26 2013 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 345 PM CDT FRI APR 26 2013 AT 3 PM...A WEAK COLD FRONT WAS LOCATED JUST NORTH OF THE FORECAST AREA FROM DULUTH SOUTHEAST THROUGH THE TWIN CITIES TO SIOUX CITY IOWA. OTHER THAN A FEW CLOUDS AND A WIND SHIFT THERE WAS NO SENSIBLE WEATHER ASSOCIATED WITH THIS FRONT. MEANWHILE FURTHER SOUTH ACROSS NORTHEAST IOWA...AND SOUTHWEST AND CENTRAL WISCONSIN... THERE WAS A 850 TO 700 MB THERMAL TROUGH. THE COMBINATION OF ML CAPES RUNNING AROUND 200 J/KG AND VERY STEEP 900 TO 800 MB LAPSE RATES HAVE RESULTED IN SOME INSTABILITY CLOUDS DEVELOPING ACROSS THIS AREA. THE NMM AND SPC WRF GENERATE A LINE OF SHOWERS IN THIS REGION FROM LATE THIS AFTERNOON INTO TONIGHT. THESE MODELS ARE ABOUT 10F TOO HIGH ON THEIR SURFACE DEW POINTS. MEANWHILE THE ARW WHICH HAS A BETTER HANDLE OF THE SURFACE DEW POINTS SHOWS NO PRECIPITATION AT ALL. WITH THE LATEST RAP SOUNDINGS CONTINUING TO SHOW A VERY SHALLOW MOISTURE LAYER AROUND 800 MB...TRENDED THE FORECAST TOWARD THE ARW FOR TONIGHT. ON SATURDAY...THE 26.12Z AND 26.18Z MODELS ARE IN VERY GOOD AGREEMENT THAT THE COLD FRONT WILL MOVE NORTH AS A WARM FRONT INITIALLY DURING THE MORNING...AND THEN QUICKLY WASHES IT OUT BY THE AFTERNOON. THE NAM/WRF GENERATES 100 TO 200 J/KG OF ML CAPE DURING THE AFTERNOON ALONG AND NORTH OF THE INTERSTATE 90 CORRIDOR. MEANWHILE THE GFS SHOWS VERY LITTLE INSTABILITY AT ALL. THE NAM/WRF LOOKS TOO HIGH ON ITS SURFACE DEW POINTS...SO PREFER THE MORE STABLE GFS. IN ADDITION...THERE IS NO SURFACE TO 850 MB MOISTURE TRANSPORT ANYWHERE IN THE FORECAST AREA. DUE TO THIS...KEPT THE FORECAST DRY. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 345 PM CDT FRI APR 26 2013 ON SUNDAY AFTERNOON...THE 26.12Z GFS SLOWED UP ITS MOVEMENT OF THE PRECIPITATION INTO SOUTHEAST MINNESOTA...AND IN WEST CENTRAL AND NORTH CENTRAL WISCONSIN. THIS IS MORE IN AGREEMENT WITH THE GEM AND ECMWF....THEREFORE...REMOVED THE PRECIPITATION CHANCES FOR THIS TIME PERIOD. FROM SUNDAY NIGHT INTO MONDAY...THE MODELS CONTINUE TO STRUGGLE WITH A COLD FRONT MOVING INTO THE REGION AND THEN MOVING BACK NORTH AS A WARM FRONT. DUE TO THESE UNCERTAINTIES...JUST WENT WITH THE CONSALL PRECIPITATION CHANCES. WITH BOTH THE 0-3 KM AND 0-6 KM SHEAR LESS THAN 30 KNOTS...NOT OVERLY CONCERNED ABOUT ANY SEVERE WEATHER AT THIS TIME. FROM TUESDAY INTO TUESDAY NIGHT...THE MODELS CONTINUE TO STRUGGLE WITH THE SPEED OF A STRONG COLD FRONT MOVING THROUGH THE REGION. ML CAPES AHEAD OF THIS CLIMB INTO THE 250 TO 750 J/KG RANGE. BOTH THE 0-3 KM AND 0-6 KM SHEAR IS FAVORABLE FOR SEVERE WEATHER. HOWEVER THERE IS A WARM LAYER BETWEEN 800 AND 700 MB WHICH MAY CAP OFF ANY PRECIPITATION PRIOR TO THE FRONTAL PASSAGE. IN THE WAKE OF THIS FRONT...TEMPERATURES WILL BE MUCH COLDER FROM WEDNESDAY THROUGH FRIDAY. THE LATEST ECMWF SUGGEST HIGHS ONLY IN THE 30S AND 40S. THE GFS IS A SLIGHTLY A BIT HIGHER. SINCE THE MODELS HAVE BEEN SO INCONSISTENT WITH THIS SYSTEM OVER THE PAST COUPLE OF DAYS...JUST STAYED WITH THE ALL BLEND FOR NOW. && .AVIATION...THROUGH 18Z SATURDAY 1230 PM CDT FRI APR 26 2013 MAIN AVIATION CONCERNS THROUGH PERIOD ARE WINDS THIS AFTERNOON...THEN WEAK COLD FRONT MOVES ACROSS THE REGION THIS EVENING. LATEST 17Z SURFACE ANALYSIS INDICATES COLD FRONT EXTENDING FROM NORTHWEST WISCONSIN TO SOUTHWEST MINNESOTA. TIGHT PRESSURE GRADIENT OUT AHEAD OF COLD FRONT IS PRODUCING SUSTAINED WIND SPEEDS OF 15 TO 20 KNOTS AND GUST UP TO 29 KNOTS PER 17Z METARS. WIND SPEEDS SHOULD REMAIN AT THESE SPEEDS THROUGH 21Z TO 22Z AT RST AND LSE TAF SITES. AS THE COLD FRONT TRACKS ACROSS THE AREA THIS EVENING...PRESSURE GRADIENT SLACKENS AND WINDS SPEEDS WILL BE LESS THAN 10 KNOTS THROUGH THE REST OF THE TAF PERIOD. DUE TO DAYTIME HEATING THIS AFTERNOON OUT AHEAD OF THE COLD FRONT... A SCATTERED DECK OF CUMULUS CLOUDS AT 4000 TO 5000 FEET WILL DEVELOP BY 21Z AT BOTH TAF SITES. THIS DECK OF CLOUDS MAY BECOME BROKEN AFTER 22Z FRIDAY TO 02Z SATURDAY AT LSE...WHERE BETTER MOISTURE EXIST. HOWEVER...THE CUMULUS DECK SHOULD REMAIN IN THE VFR RANGE. AFTER 02Z SATURDAY...VFR CONDITIONS WILL PREVAIL. && .HYDROLOGY... ISSUED AT 345 PM CDT FRI APR 26 2013 TRIBUTARY STREAMS CONTINUE TO FALL FOR THE MOST PART. HIGH WATER CONTINUES ALONG THE BLACK AND TREMPEALEAU RIVERS...WITH THE BLACK STILL SEEING SOME IMPACTS FROM MELTING SNOW UP IN THE HEADWATER AREAS OF CLARK/TAYLOR COUNTIES. EXPECT TO SEE SOME ADDITIONAL RISES ALONG THE BLACK IN THE COMING DAYS DUE TO THE WARMING TEMPERATURES. FOR THE MISSISSIPPI RIVER...IT LOOKS TO CONTINUE RISING SLOWLY ALL THE WAY INTO THE SECOND WEEK OF MAY. HOW HIGH IT GETS WILL DEPEND GREATLY ON HOW MUCH RUNOFF MOVES DOWNSTREAM FROM THE SNOW COVERED AREAS OF CENTRAL/NORTHERN MN...AND NORTHWEST WI. THE LATEST FORECASTS ATTEMPT TO TAKE THIS SNOWMELT RUNOFF INTO ACCOUNT...BUT MODIFICATIONS TO THE FORECAST ARE LIKELY. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...DTJ HYDROLOGY...WELVAERT
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND SATURDAY ISSUED AT 210 PM CDT FRI APR 26 2013 LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW THE WARM ADVECTION PRECIP FROM EARLIER TODAY RACING OFF INTO SOUTHEAST ONTARIO WHILE A WEAK FRONT IS NOW SLIDING INTO NORTHERN IOWA AND WESTERN WISCONSIN. THE FRONT IS RELATIVELY INACTIVE EARLY THIS AFTERNOON EXCEPT FOR A DEVELOPING CU FIELD OVER NORTHEAST IOWA. MEANWHILE...A TRAILING LINE OF MID-CLOUDS IS LINGERING ACROSS NE WISCONSIN ALONG THE TAIL END OF A SHORTWAVE MOVING ACROSS ONTARIO...WHICH IS KEEPING SKIES PARTLY TO MOSTLY CLOUDY IN SPOTS. TEMPERATURES HAVE WARMED INTO THE MID 50S NORTH TO MID 60S SOUTH AS WARMER AIR INVADES THE REGION. AS THE FRONT SAGS INTO CENTRAL AND NE WISCONSIN LATER TODAY...PRECIP CHANCES ARE THE MAIN FORECAST CONCERN. TONIGHT...A WEAK FRONT WILL SAG ACROSS THE STATE FROM LA CROSSE TO MARINETTE WHERE IT WILL STALL FOR MOST OF THE NIGHT. RATHER BAGGY LOW LEVEL THETAE AXIS WILL RESIDE ABOVE THE FRONTAL BOUNDARY...BUT PROGGED SOUNDINGS DO NOT SHOW MUCH SATURATION AND DEWPOINTS MIXED OUT TOO MUCH TODAY FOR INSTABILITY TO DEVELOP. IN ADDITION...DO NOT THINK WEAK FORCING ALONG THE FRONT WILL BE ENOUGH TO OVERCOME LOSS OF HEATING AND INCREASING SUBSIDENCE ALOFT. MANY OF THE HI RES MODELS SHOW PRECIP EXPANDING OVER NORTHEAST WISCONSIN THIS EVENING...BUT THINK THIS WILL BE TOUGH DUE TO THE REASONS MENTIONED ABOVE. NORTH OF THE FRONT...WINDS WILL TURN CALM...WHICH COMBINED WITH SNOW MELT AND CLEAR SKIES...WILL PROMOTE FOG FORMATION LATE TONIGHT. HAVE EXPANDED AREAS OF FOG INTO CENTRAL WISCONSIN. LOWS FALLING INTO THE MID 30S NORTH OF THE FRONT...AND INTO THE MID OR UPPER 40S SOUTH OF THE FRONT. SATURDAY...THE FRONT WILL STILL BE AROUND AT THE START OF THE MORNING BUT WILL EVENTUALLY WASH OUT BY MIDDAY OR SO. MOISTURE WILL LINGER HOWEVER...AND SHOULD LEAD TO A DIURNAL CU FIELD. SOME MODELS SPIT OUT LIGHT QPF TOMORROW AFTERNOON...BUT THAT IS LIKELY DUE TO DEWPOINTS REACHING INTO THE UPPER 40S. JUDGING BY CONDITIONS UPSTREAM...UPPER 30S TO LOW 40S DEWPOINTS ARE MORE REASONABLE...WHICH WILL NOT BE ENOUGH TO GENERATE MUCH CAPE. SO THINK MODELS ARE TOO PESSIMISTIC ONCE AGAIN AND WILL GO WITH A DRY FORECAST. 925MB TEMPS ARGUE FOR HIGHS NEAR 70...AND WILL BUMP UP TEMPS INTO THE UPPER 60S EXCEPT NEAR LAKE MICHIGAN. .LONG TERM...SATURDAY NIGHT THROUGH FRIDAY ISSUED AT 210 PM CDT FRI APR 26 2013 THE MAIN FCST CONCERNS INCLUDE PCPN TRENDS STARTING SUNDAY NIGHT... THEN ABOVE NORMAL TEMPS TRENDING TOWARD BELOW NORMAL CONDITIONS AGAIN BY THE LATTER HALF OF THE NEXT WORK WEEK. DRY AND MILD CONDITIONS ARE EXPECTED AHEAD OF THE NEXT APPROACHING COLD FRONT ON SATURDAY NIGHT AND SUNDAY. PARTLY CLOUDY SKIES AND MIXING THROUGH 850-800 MB SHOULD YIELD MAX TEMPS IN THE UPPER 60S AND LOWER 70S...EXCEPT NEAR LK MICH...WHERE READINGS WILL BE IN THE 50S AND LOWER 60S. A COLD FRONT WILL PUSH INTO THE FORECAST AREA SUNDAY NIGHT AND MONDAY...THEN LIFT BACK TO THE NORTH AS A WARM FRONT AS SOUTH FLOW INCREASES ON MONDAY NIGHT. SCT SHRA/ISOLD TSRA ARE ANTICIPATED THROUGH THIS PERIOD. THE WARMEST DAY OF THE WEEK IS EXPECTED ON TUESDAY...WITH HIGHS IN THE 70 TO 75 RANGE OVER MOST INLAND AREAS. A COLD FRONT WILL MOVE INTO THE WSTRN PART OF THE FA LATE TUESDAY...THEN THROUGH THE REST OF THE CWA TUESDAY NIGHT. THIS FRONT SHOULD PROVIDE OUR BEST BET FOR ORGANIZED THUNDERSTORM ACTIVITY DURING THE NEXT WEEK. SIGNIFICANT DIFFERENCES DEVELOP BY WEDNESDAY AND WEDNESDAY NIGHT... AS THE GFS TAKES MOST OF THE PCPN EAST OF THE REGION WHILE THE ECMWF DEVELOPS A BAND OF SIGNIFICANT POST-FRONTAL PCPN IN ASSOCIATION WITH A STG RRQ OF AN UPPER JET AND INCOMING UPPER TROF. WILL JUST CARRY MID-RANGE POPS FOR NOW...AND SEE HOW THIS EVOLVES. MUCH COLDER AIR WILL PUSH INTO THE AREA WEDNESDAY NIGHT...AND LINGER INTO FRIDAY. IN ADDITION...THE DEEP UPPER TROF IS EXPECTED TO DEVELOP INTO A CUT-OFF LOW OVER THE GREAT LAKES BY THE END OF THE WORK WEEK. DESPITE THE CALENDAR READING EARLY MAY...CAN`T IGNORE THE POSSIBILITY OF SOME LIGHT SNOW SHOWERS...ESPECIALLY OVER NC WI LATE WEDS NGT/ EARLY THU...AND OVER MOST OF THE FA LATE THU NGT INTO EARLY FRIDAY. TEMPERATURES WILL RETURN TO MUCH BELOW NORMAL LEVELS. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1234 PM CDT FRI APR 26 2013 A WEAK FRONT WILL STALL ACROSS CENTRAL AND NORTHEAST WISCONSIN THIS AFTERNOON AND WILL HANG AROUND THROUGH SATURDAY. ISOLATED SHOWERS ARE POSSIBLE ALONG THE FRONT LATE THIS AFTERNOON INTO EARLY THIS EVENING...BUT ODDS ARE TOO SMALL TO INCLUDE IN THE TAFS AT THIS TIME. HOWEVER...WITH THE FRONT DRAPED ACROSS THE REGION...ONGOING SNOW MELT...AND WINDS TURNING CALM...FOG LOOKS LIKE A GOOD BET ACROSS CENTRAL AND NORTH-CENTRAL WISCONSIN LATE TONIGHT. THE FOG COULD BECOME DENSE AT TIMES OVER NORTH-CENTRAL WISCONSIN. THE FOG WILL BURN OFF BY MID-MORNING TOMORROW WHICH WILL LEAD TO BUILDING CLOUDS BY MIDDAY. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......KIECKBUSCH AVIATION.......MPC