Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 06/11/12


AREA FORECAST DISCUSSION
NWS PUEBLO CO
1129 PM MDT FRI JUN 8 2012 .AVIATION... VFR CONDITIONS ARE EXPECTED FOR THE NEXT 24 HRS AT KALS...KCOS AND KPUB. S TO SW WINDS ARE EXPECTED TO PICK UP AT KALS BETWEEN ABOUT 15Z AND 17Z AND THEN CONTINUE TO BE WINDY THRU THE AFTERNOON AND INTO THE EARLY EVENING AT 20-30KTS. S TO SW WINDS ARE ALSO EXPECTED AT KCOS AND KPUB BY 17-19Z WITH AT 15-20KT WITH GUSTS OF 25-30 KTS. && .PREV DISCUSSION... /ISSUED 337 PM MDT FRI JUN 8 2012/ SHORT TERM... TONIGHT AND SATURDAY) ..SMALL PROBABILITY FOR SEVERE WEATHER LATE THIS AFTERNOON AND EVENING EAST OF THE I-25 CORRIDOR...THEN CRITICAL FIRE WEATHER CONDITIONS EXPECTED FOR SATURDAY... STILL SOME MODERATE FLOW ALOFT...THOUGH SEEM TO BE LACKING ANY DISTINCT SHORTWAVES TODAY TO HELP FIRE OFF CONVECTION. SFC PRESSURE FALLS EAST OF THE MOUNTAINS HAS ALLOWED DEW POINTS TO FALL OFF INTO THE 30S AND LOWER 40S ALONG THE I-25 CORRIDOR...WHILE DEW POINTS REMAIN IN THE MID TO UPPER 50S ACROSS THE FAR SE PLAINS. 16Z HRRR MIXES DRY LINE EASTWARD TO ALONG A LINE FROM ROUGHLY KIM TO LA JUNTA BY 00Z WITH CONVERGENCE ALONG THE DRY LINE...AND ELEVATED HEATING ALONG THE RIDGE OF OF THE RATON MESA TRIGGERING SOME ISOLATED THUNDERSTORMS DURING THE LATE AFTERNOON/EARLY EVENING HOURS. WITH THE POOLING DEW POINTS EAST OF THE DRY LINE...COULD SEE CAPES 1500-2000+ J/KG...WITH HIGHEST VALUES NEAR THE CO/KS BORDER. EACH SUCCESSIVE HRRR RUN SEEMS TO GENERATE THUNDERSTORMS ALONG THE NRN SLOPES OF THE RATON...EASTWARD ACROSS BACA...BENT...PROWERS...AND KIOWA COUNTIES AFTER 21Z. WITH SUCH HIGH CAPE VALUES...AND DEEP LAYER SHEARS STILL RUNNING AROUND 30-40 KTS...THERE IS STILL A CHANCE FOR AN ISOLATED SEVERE THUNDERSTORM EAST OF THE DRY LINE. SPC HAS A 5% PROB FOR SEVERE HAIL AND DAMAGING WINDS...THOUGH COVERAGE SHOULD BE FAIRLY ISOLATED GIVEN LACK OF STRONG FORCING ALOFT. HAVE INTRODUCED SOME POPS ACROSS THE FAR EASTERN COUNTIES THROUGH 03Z. AFTER SUNSET...CONVECTION SHOULD DIMINISH QUICKLY WITH LOSS OF HEATING. SATURDAY STILL LOOKS TO BE A DRY AND WINDY DAY ACROSS SOUTH CENTRAL AND SOUTHEAST COLORADO. A CALL AROUND TO FIRE DISTRICTS OUT WEST INDICATES THAT DRYING FUELS SHOULD REACH CRITICAL LEVELS ACROSS THE SAN LUIS VALLEY BY TOMORROW. WITH FLOW ALOFT INCREASING AHEAD OF THE UPPER TROF DIGGING THROUGH THE NRN GREAT BASIN AND INTO WRN MT SATURDAY...SHOULD SEE SOUTHWESTERLY WINDS SPREADING DOWN THE MOUNTAINS AND INTO THE VALLEYS DURING THE LATE MORNING...AND ACROSS MOST OF THE PLAINS BY EARLY AFTERNOON. HUMIDITY VALUES WILL FALL BELOW 15 PERCENT FOR ALL AREAS...WITH GUSTS IN THE 30 TO 40 MPH RANGE...WITH THE STRONGEST WINDS ACROSS THE MOUNTAINS. IN ADDITION TO THE SAN LUIS VALLEY...FUELS ARE CRITICAL ACROSS THE SOUTHEAST MOUNTAINS AND FREMONT COUNTY...AND WILL BE UPGRADING THE FIRE WEATHER WATCH TO A RED FLAG WARNING WITH THE AFTERNOON PACKAGE ISSUANCE. ITS IMPORTANT TO NOTE...THAT WEATHER CONDITIONS WILL ALSO BE CRITICAL ACROSS ALL OF SOUTH CENTRAL AND SOUTHEAST COLORADO. MANY AREAS ACROSS THE PLAINS HAD RAIN IN THE RECENT DAYS...BUT SOME MISSED OUT...AND FINER FUELS MAY BE CRITICALLY DRY IN THESE PATCHY AREAS. HOWEVER...FUELS ACROSS FIRE ZONES 232...233 (EASTERN LAS ANIMAS AND OTERO COUNTIES)...WHICH ALSO MISSED OUT ON MOST OF THE PRECIPITATION THE PAST FEW DAYS...HAVE SOLID REPORTS OF SUFFICIENT GREEN UP TO OFFSET ANY CURING FUELS...SO HAVE LEANED HEAVILY ON THESE REPORTS FOR OTHER AREAS SUCH AS PUEBLO COUNTY...AND PORTIONS OF CROWLEY COUNTY WHICH RECEIVED SIMILAR RAINFALL AMOUNTS. THUS RED FLAG WARNING WILL BE CONFINED TO THE MOUNTAINS AND VALLEYS. STILL SUFFICIENT GREEN UP FROM SNOW MELT ACROSS THE HIGHER ELEVATIONS OF THE SOUTHWEST AND CENTRAL MOUNTAINS AS WELL...SO THOSE WILL NOT BE INCLUDED. OTHERWISE...EXPECT A NICE SUMMER-LIKE DAY ON SATURDAY...WITH HIGHS WELL INTO THE 90S ACROSS THE PLAINS...80S FOR THE VALLEYS...AND 60S AND 70S FOR THE MOUNTAINS. -KT LONG TERM... (SATURDAY NIGHT THROUGH FRIDAY) SATURDAY NIGHT AND SUNDAY...AS A TROUGH MOVES ACROSS WYOMING AND MONTANA SATURDAY NIGHT AND INTO SUNDAY...A COLD FRONT WILL MOVE SOUTHWARD OVER THE PLAINS AND EASTERN MOUNTAINS. BEHIND THE COLD FRONT...LOWER LEVELS WILL BE DRY WITH DEW POINTS MOSTLY IN THE 30S. AS A RESULT...CHANCES FOR PRECIPITATION BEHIND THE FRONT ARE MINIMAL. ONLY HAVE ISOLATED POPS OVER THE INTERSTATE 25 CORRIDOR AND EASTERN MOUNTAINS WHERE MODELS SUGGEST VERY MODEST CAPE VALUES IN THE LATE AFTERNOON. IN THE EVENING...SECONDARY TROUGH WILL MOVE ACROSS THE REGION. THE TROUGH MAY BE STRONG ENOUGH TO FIRE SOME CONVECTION...AND MAINTAINED THE ISOLATED POPS OVER PORTIONS OF THE PLAINS. AIR ALOFT WILL BE DRY AND DECIDED NOT TO ADD ANY POPS TO THE MOUNTAINS. A QUICK LOOK AT THE 18Z NAM IS A LITTLE MORE FAVORABLE FOR PRECIPITATION OVER THE PLAINS SUNDAY NIGHT. MONDAY...UPSLOPE FLOW CONTINUES OVER THE PLAINS AND EASTERN MOUNTAINS. MODELS KEEP THE HIGHER DEW POINTS TO THE SOUTH OF THE CWA. ONLY HAVE ISOLATED POPS OVER THE EASTERN MOUNTAINS AND PORTIONS OF THE PLAINS WHERE SOME MODELS HAVE A FEW HUNDRED JOULES OF CAPE. AIR ALOFT REMAINS DRY AND DID NOT ADD ANY POPS TO THE REMAINING MOUNTAINS. TEMPERATURES ON THE PLAINS WILL BE NEAR TO SLIGHTLY BELOW NORMAL WITH COOLER AIR MASS OVER THE REGION. TUESDAY THROUGH FRIDAY...AS HIGH PRESSURE MOVES INTO THE HIGH PLAINS...RETURN FLOW MAY BRING MORE LOW LEVEL MOISTURE INTO THE REGION. BEST CHANCES FOR PRECIPITATION OVER THE EASTERN MOUNTAINS AND INTERSTATE 25 CORRIDOR APPEAR TO BE TUESDAY AFTERNOON AND EVENING. STARTING WEDNESDAY...TROUGH STARTS MOVING INTO THE PACIFIC NORTHWEST WITH THE FLOW ALOFT BECOMING SOUTHWESTERLY. A LEE TROUGH/DRY LINE COULD DEVELOP NEAR THE KANSAS BORDER...WITH BEST PRECIPITATION CHANCES ON THE EASTERN PLAINS. POTENTIAL FOR SEVERE WEATHER WILL DEPEND ON THE AMOUNT OF LOW LEVEL MOISTURE AND ANY EMBEDDED DISTURBANCES. TOUGH TO FORECAST THESE SUBTLE FEATURES IN DAYS 4 TO 7...AND WILL HAVE TO MONITOR FOR ANY SEVERE THREAT. --PGW-- AVIATION... VFR CONDITIONS EXPECTED AT TAF SITES WITH GUSTY SOUTH WIND IN THE 20-25 KT RANGE EXPECTED TO DIMINISH DURING THE EVENING. ISOLATED TCU POSSIBLE TO THE EAST OF KPUB...AND TO THE NORTH AND EAST OF KCOS THROUGH THIS EVENING...BUT WITH LOW LEVELS DRYING OUT...THESE ARE NOT EXPECTED TO DIRECTLY AFFECT THE TAF SITES. SKIES WILL REMAIN CLEAR OVERNIGHT...WITH SOUTHWEST WINDS SPREADING INTO KCOS AND KALS DURING THE LATE MORNING...AND BY 18-19Z AT KPUB. GUSTS IN THE 25-30 KT RANGE WILL BE POSSIBLE THROUGH THE AFTERNOON. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 10 AM TO 9 PM MDT SATURDAY FOR COZ221-222- 224-225. && $$
AREA FORECAST DISCUSSION
NWS ALBANY NY
635 AM EDT SAT JUN 9 2012 .SYNOPSIS... A FRONTAL BOUNDARY DRAPED ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND ISOLATED THUNDERSTORMS TODAY...ESPECIALLY FROM THE CAPITAL REGION ON SOUTH. BY SUNDAY...THIS FRONT WILL LIFT NORTH AS A WARM FRONT...ALLOWING FOR WARMER AND MORE HUMID AIR TO RETURN TO THE REGION. DRY AND WARM CONDITIONS WILL DOMINATE ON MONDAY...BEFORE THE THREAT FOR SHOWERS AND THUNDERSTORMS RETURNS FOR THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 635 AM EDT...LATEST REGIONAL MOSAIC RADAR AND SFC OBS SHOWS LIGHT RAIN SHOWERS ALREADY MOVING ACROSS CENTRAL NY...WITH ADDITIONAL ACTIVITY DEVELOPING ACROSS WESTERN NY/SOUTHERN ONTARIO. THIS ACTIVITY IS MOVING SOUTHEASTWARD WITHIN NW FLOW ALONG A WEAK SFC FRONTAL BOUNDARY THAT IS DRAPED ACROSS THE AREA. WE HAVE RAISED POPS TO LIKELY FOR WESTERN PARTS OF THE AREA FOR THE MORNING HOURS...AS THE ACTIVITY WILL SLIDE FROM THE WESTERN MOHAWK VALLEY...ACROSS THE CATSKILLS AND INTO PORTIONS OF THE MID HUDSON VALLEY BY THE MID MORNING HOURS. FURTHER NORTH...HAVE GONE WITH JUST CHC/SLIGHT CHC POPS FOR THE CAPITAL REGION INTO THE SRN ADIRONDACKS. THE LATEST 07 UTC HRRR SHOWS THIS INITIAL ACTIVITY MOVING THROUGH THE AREA FOR THE MORNING...WITH SOME ADDITIONAL SCT ACTIVITY FOR THE AFTN. WILL KEEP CHC POPS FOR THE AFTN HOURS...WITH THE BEST THREAT FOR WESTERN AND SOUTHERN PARTS OF THE REGION. SKIES LOOK MOSTLY CLOUDY FOR THE MAJORITY OF THE CWA FOR THE DAY. OUR REGION WILL REMAIN ON THE COOLER AND MORE STABLE SIDE OF THE BOUNDARY. THE 00 UTC GFS/ECMWF SHOWS THE BEST RIBBON OF INSTABILITY TODAY WILL EXTEND FROM WESTERN NY TOWARDS EAST-CENTRAL PA AND NJ. WITH PLENTY OF MID/HIGH LEVEL CLOUDINESS HEADED TOWARDS OUR AREA THIS MORNING...AND FORECASTED SHOWALTER VALUES TO ONLY DROP TO AS LOW AS +2 C...THIS SHOULD PREVENT MUCH THUNDER FROM OCCURRING ACROSS OUR AREA. HAVE KEPT A SLIGHT CHC OF THUNDER IN THE FORECAST FOR THE AFTN...BUT IT DOESN/T LOOK TOO WIDESPREAD...AND ANY STRONG TO LOCALLY SEVERE STORMS WILL REMAIN TO OUR SOUTH AND WEST TODAY. HAVE GONE WITH A MET/MAV BLEND FOR TEMPS TODAY...WITH 70S FOR MOST AREAS. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... WITH THE LOSS OF DAYTIME HEATING...SHOWERS AND ISOLD THUNDERSTORMS WILL WEAKEN THIS EVENING. WILL LOWER POPS TO JUST SLIGHT CHC FOR THE OVERNIGHT HOURS. THIS SHOULD ALLOW FOR BREAKS IN THE CLOUDS...ESP FOR NORTHERN AREAS. WITH LIGHT WINDS IN PLACE...GOOD RADIATIONAL COOLING WITH TAKE PLACE...AND A COOL NIGHT WILL OCCUR FOR THE SRN DACKS/LAKE GEORGE AREA. MIN TEMPS ACROSS THE AREA WILL RANGE FROM THE 40S IN NORTHERN AREAS...TO MID TO UPPER 50S IN CAPITAL REGION/MID HUDSON VALLEY. THE LINGERING FRONTAL BOUNDARY WILL START TO LIFT AS A WARM FRONT ON SUNDAY...AS WEAK FLOW FROM THE SURFACE-850 HPA FROM THE W-SW STARTS TO BUILD INTO THE AREA. SOME ISOLD SHOWERS/TSTMS MAY DEVELOP WITHIN THE DAYTIME HEATING ALONG THE FRONTAL BOUNDARY DURING THE LATE MORNING THROUGH EARLY EVENING HOURS. WITH 850 HPA TEMPS WARMING TO 12-16 DEGREES C...WARMER MAX TEMPS ARE EXPECTED FOR SUNDAY...WITH 80S ACROSS THE AREA. HUMIDITY WILL START TO CREEP UP...BUT IT WON/T BECOME TOO UNBEARABLE JUST YET...WITH TDS IN THE UPPER 50S TO LOW 60S F. A NARROW AREA OF STRONG RIDGING AT 500 HPA WILL BUILD INTO THE AREA FOR SUNDAY NIGHT INTO MONDAY. WITH THE WARMER TEMPS/HIGHER HEIGHTS ALOFT...THIS SHOULD PUT A CAP IN PLACE...AND PREVENT ANY CONVECTION FOR SUNDAY NIGHT THROUGH MONDAY. WITH THE S-SE SURFACE FLOW...WE WILL HAVE TO WATCH IF ENOUGH MOISTURE COMES OFF THE ATLANTIC TO ALLOW A MARINE LAYER TO SNEAK UP THE HUDSON VALLEY. THIS COULD ALLOW FOR SOMEWHAT COOLER TEMPS FOR THE MID HUDSON VALLEY FOR MONDAY. OTHERWISE...TEMPS ON MONDAY LOOK PRETTY WARM...ESP FOR THE CAPITAL REGION...WITH MID 80S EXPECTED. DEWPOINTS WILL REACH THE MID 60S IN SOME AREAS AS WELL...ALLOWING FOR A MORE UNCOMFORTABLE DAY. BY MONDAY NIGHT...IT STILL LOOKS DRY FOR MOST AREAS. HOWEVER...HAVE GONE WITH SLIGHT CHC POPS FOR WESTERN AREAS...IN CASE CONVECTION OVER WESTERN NY DRIFTS TOWARDS THE AREA...AS THE RIDGE AXIS STARTS TO SHIFT EASTWARD. MON NIGHT MIN TEMPS LOOK TO BE IN THE UPPER 50S ACROSS THE WHOLE AREA...WITH MUGGY TDS CONTINUING. && .LONG TERM /TUESDAY THROUGH FRIDAY/... THE UPPER JAMES BAY LOW AND SHORT WAVE ENERGY ACROSS THE NORTHERN PLAINS ARE FORECAST TO INTERACT AND MERGE OVER JAMES BAY REGION DURING THE WEEK. MEANWHILE...THE SHORT WAVE RIDGE AXIS OVER THE ATLANTIC SEABOARD WILL EXIT FURTHER OFFSHORE ALLOWING A TROPICAL MOISTURE CONNECTION TO ADVANCE NORTHWARD. THIS MOISTURE AND THE APPROACH OF THE FRONTAL BOUNDARY AS THAT AFOREMENTIONED SHORT WAVE MERGES OVER JAMES BAY WILL SET THE STAGE FOR A POTENTIALLY ACTIVE WEATHER DAY FOR THE CWFA TUESDAY. WE WILL RETAIN THE HIGH CHANCE POPS AND NEAR OR SLIGHTLY ABOVE SEASONABLE TEMPERATURES. QUESTION REMAINS JUST HOW FAR TO THE EAST THIS FRONT WILL PROGRESS AS THE GGEM/GFS REMAIN THE SLOWEST WITH A SURFACE WAVE DEVELOPING OVER THE DELMARVA REGION WHILE THE ECMWF IS THE MOST PROGRESSIVE. ENSEMBLE APPROACH FAVORS A BLENDED MODEL SOLUTIONS SO WE WILL RETAIN AN SLIGHT CHANCE POPS BEYOND TUESDAY INTO THURSDAY WITH MORE CLOUDS THAN SUN AND AWAIT FOR FUTURE TRENDS AND CONFIDENCE. THEREAFTER...WE WILL KEEP THE WEATHER DRY FOR NOW AND TEMPERATURES BEGINNING TO CLIMB ABOVE SEASONABLE LEVELS ALONG WITH HIGHER DEWPOINTS GIVEN THE LACK OF THERMALLY ADVECTIVE CHANGES SEEN IN THE ENSEMBLES THIS MORNING. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... REGIONAL RADAR MOSAIC REVEALS AN EXPANDING AREA OF SHOWERS ACROSS WESTERN AND CENTRAL NY. THIS AREA OF RAINFALL WILL MOVE ACROSS MOST OF THE TAF SITES THIS MORNING INTO EARLY AFTERNOON. SOME RESIDUAL IFR CONDITIONS THIS MORNING WITH LOW CIGS AND VIS DUE TO FOG...BUT THIS SHOULD QUICKLY IMPROVE TO VFR TODAY. THERE COULD BE A PERIOD OF MVFR WITH THE HEAVIER SHOWERS LATER THIS MORNING. TONIGHT...AS RAINFALL SLIDES SOUTHEAST OF THE REGION...WE ONCE AGAIN FOCUS OUR ATTENTION TO FOG FORMATION. FOR NOW...WE WILL PLACE `MIFG`. WINDS WILL REMAIN LIGHT AT SPEEDS LESS THAN 5KTS AND VARIABLE DIRECTION EARLY THIS MORNING...AND BECOME WEST-SOUTHWEST AT SPEEDS AROUND 10 KTS OR LESS. WINDS BECOME LIGHT AND VARIABLE ONCE AGAIN TONIGHT. OUTLOOK... SUN...VFR. CHC MVFR IN SCT -SHRA/TSRA. CHC EARLY AM MVFR/IFR WITH FOG/STRATUS POSSIBLE. MON...VFR...NO SIG WX. CHC LATE NT/EARLY AM MVFR/IFR WITH FOG/STRATUS POSSIBLE. TUE...VFR/MVFR...INCR CHC SHRA/TSRA. LATE NT/EARLY AM MVFR/IFR WITH FOG/STRATUS POSSIBLE. WED...VFR...CHC MVFR -SHRA. LATE NT/EARLY AM MVFR/IFR WITH FOG/STRATUS POSSIBLE. && .FIRE WEATHER... NO FIRE WEATHER CONCERNS ACROSS THE AREA OVER THE NEXT SEVERAL DAYS. RAIN SHOWERS WILL IMPACT THE REGION TODAY...ESP FROM THE CAPITAL REGION ON SOUTH. RH VALUES WILL BE NEAR 100 PERCENT EARLY THIS MORNING...AND WILL RETURN TO NEAR 100 PERCENT TONIGHT INTO EARLY SUNDAY MORNING AS WELL. WINDS WILL BE LIGHT AND VARIABLE TODAY AND TONIGHT. WINDS WILL BECOME SOUTHERLY ON SUNDAY AT 4-8 MPH. && .HYDROLOGY... NO SIGNFICANT HYDRO PROBLEMS ARE EXPECTED ACROSS THE REGION OVER THE NEXT FIVE DAYS. A FRONTAL BOUNDARY DRAPED ACROSS THE REGION WILL ALLOW FOR SOME SHOWERS AND ISOLATED THUNDERSTORMS TODAY. THE BEST FOCUS FOR SHOWERS WILL EXTEND FROM THE WESTERN MOHAWK VALLEY SOUTHEASTWARD ACROSS THE CATSKILLS AND TOWARDS THE MID HUDSON VALLEY. BASIN AVERAGE RAINFALL WILL ONLY BE UP TO A THIRD OF AN INCH...WHICH SHOULD HAVE LITTLE AFFECT ON AREA RIVERS AND STREAMS...ALTHOUGH A FEW SPOTS MAY LOCALLY RECEIVE SLIGHTLY HIGHER AMOUNTS OF RAINFALL. DRIER WEATHER WILL RETURN TO THE AREA FOR SUNDAY AND MONDAY...WHICH SHOULD ALLOW RIVERS TO HOLD STEADY OR SLOWLY RECEDE. 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 NEAR TERM...FRUGIS SHORT TERM...FRUGIS LONG TERM...BGM AVIATION...BGM FIRE WEATHER...FRUGIS HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
359 AM EDT SAT JUN 9 2012 .SYNOPSIS... A FRONTAL BOUNDARY DRAPED ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND ISOLATED THUNDERSTORMS TODAY...ESPECIALLY FROM THE CAPITAL REGION ON SOUTH. BY SUNDAY...THIS FRONT WILL LIFT NORTH AS A WARM FRONT...ALLOWING FOR WARMER AND MORE HUMID AIR TO RETURN TO THE REGION. DRY AND WARM CONDITIONS WILL DOMINATE ON MONDAY...BEFORE THE THREAT FOR SHOWERS AND THUNDERSTORMS RETURNS FOR THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 359 AM EDT...LATEST REGIONAL MOSAIC RADAR SHOWS A BATCH OF SHOWERS ACROSS WESTERN NY...WITH ADDITIONAL ACTIVITY UPSTREAM ACROSS NORTHERN MICHIGAN AND ONTARIO. THIS ACTIVITY...AIDED BY A WEAK AREA OF VORTICITY AT 500 HPA...WILL DIVE SOUTHEASTWARD THROUGHOUT THE MORNING ALONG A STALLED OUT SURFACE BOUNDARY. THE BEST FOCUS FOR SHOWERS WILL BE FROM THE WESTERN MOHAWK VALLEY...TOWARDS THE SCHOHARIE VALLEY...EASTERN CATSKILLS...MID HUDSON VALLEY...AND PERHAPS INTO NW CT. ALTHOUGH THE LATEST HRRR SHOWS PRECIP SPREADING ACROSS THE AREA BY SUNRISE...RADAR TRENDS WOULD SUGGEST BETTER TIMING FOR WIDESPREAD SHOWERS WOULD BE LATER IN THE MORNING AND INTO THE AFTN...WHICH THE GLOBAL MODEL GUIDANCE AGREES WITH AS WELL. HAVE GONE WITH CHC POPS STARTING IN THE MORNING...AND A SMALL AREA OF LIKELY POPS FOR WESTERN PORTIONS OF THE CWA FOR THE AFTN HOURS. FAR NORTHERN AREAS...SUCH AS THE DACKS...SHOULD REMAIN FAR ENOUGH AWAY FROM THE BOUNDARY FOR ONLY ISOLD SHOWERS TODAY. OUR REGION WILL REMAIN ON THE COOLER AND MORE STABLE SIDE OF THE BOUNDARY. THE 00 UTC GFS/ECMWF SHOWS THE BEST RIBBON OF INSTABILITY TODAY WILL EXTEND FROM WESTERN NY TOWARDS EAST-CENTRAL PA AND NJ. WITH PLENTY OF MID/HIGH LEVEL CLOUDINESS HEADED TOWARDS OUR AREA THIS MORNING...AND FORECASTED SHOWALTER VALUES TO ONLY DROP TO AS LOW AS +2 C...THIS SHOULD PREVENT MUCH THUNDER FROM OCCURRING ACROSS OUR AREA. HAVE KEPT A SLIGHT CHC OF THUNDER IN THE FORECAST...BUT IT DOESN/T LOOK TOO WIDESPREAD...AND ANY STRONG TO LOCALLY SEVERE STORMS WILL REMAIN TO OUR SOUTH AND WEST TODAY. HAVE GONE WITH A MET/MAV BLEND FOR TEMPS TODAY...WITH 70S FOR MOST AREAS. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... WITH THE LOSS OF DAYTIME HEATING...SHOWERS AND ISOLD THUNDERSTORMS WILL WEAKEN THIS EVENING. WILL LOWER POPS TO JUST SLIGHT CHC FOR THE OVERNIGHT HOURS. THIS SHOULD ALLOW FOR BREAKS IN THE CLOUDS...ESP FOR NORTHERN AREAS. WITH LIGHT WINDS IN PLACE...GOOD RADIATIONAL COOLING WITH TAKE PLACE...AND A COOL NIGHT WILL OCCUR FOR THE SRN DACKS/LAKE GEORGE AREA. MIN TEMPS ACROSS THE AREA WILL RANGE FROM THE 40S IN NORTHERN AREAS...TO MID TO UPPER 50S IN CAPITAL REGION/MID HUDSON VALLEY. THE LINGERING FRONTAL BOUNDARY WILL START TO LIFT AS A WARM FRONT ON SUNDAY...AS WEAK FLOW FROM THE SURFACE-850 HPA FROM THE W-SW STARTS TO BUILD INTO THE AREA. SOME ISOLD SHOWERS/TSTMS MAY DEVELOP WITHIN THE DAYTIME HEATING ALONG THE FRONTAL BOUNDARY DURING THE LATE MORNING THROUGH EARLY EVENING HOURS. WITH 850 HPA TEMPS WARMING TO 12-16 DEGREES C...WARMER MAX TEMPS ARE EXPECTED FOR SUNDAY...WITH 80S ACROSS THE AREA. HUMIDITY WILL START TO CREEP UP...BUT IT WON/T BECOME TOO UNBEARABLE JUST YET...WITH TDS IN THE UPPER 50S TO LOW 60S F. A NARROW AREA OF STRONG RIDGING AT 500 HPA WILL BUILD INTO THE AREA FOR SUNDAY NIGHT INTO MONDAY. WITH THE WARMER TEMPS/HIGHER HEIGHTS ALOFT...THIS SHOULD PUT A CAP IN PLACE...AND PREVENT ANY CONVECTION FOR SUNDAY NIGHT THROUGH MONDAY. WITH THE S-SE SURFACE FLOW...WE WILL HAVE TO WATCH IF ENOUGH MOISTURE COMES OFF THE ATLANTIC TO ALLOW A MARINE LAYER TO SNEAK UP THE HUDSON VALLEY. THIS COULD ALLOW FOR SOMEWHAT COOLER TEMPS FOR THE MID HUDSON VALLEY FOR MONDAY. OTHERWISE...TEMPS ON MONDAY LOOK PRETTY WARM...ESP FOR THE CAPITAL REGION...WITH MID 80S EXPECTED. DEWPOINTS WILL REACH THE MID 60S IN SOME AREAS AS WELL...ALLOWING FOR A MORE UNCOMFORTABLE DAY. BY MONDAY NIGHT...IT STILL LOOKS DRY FOR MOST AREAS. HOWEVER...HAVE GONE WITH SLIGHT CHC POPS FOR WESTERN AREAS...IN CASE CONVECTION OVER WESTERN NY DRIFTS TOWARDS THE AREA...AS THE RIDGE AXIS STARTS TO SHIFT EASTWARD. MON NIGHT MIN TEMPS LOOK TO BE IN THE UPPER 50S ACROSS THE WHOLE AREA...WITH MUGGY TDS CONTINUING. && .LONG TERM /TUESDAY THROUGH FRIDAY/... THE UPPER JAMES BAY LOW AND SHORT WAVE ENERGY ACROSS THE NORTHERN PLAINS ARE FORECAST TO INTERACT AND MERGE OVER JAMES BAY REGION DURING THE WEEK. MEANWHILE...THE SHORT WAVE RIDGE AXIS OVER THE ATLANTIC SEABOARD WILL EXIT FURTHER OFFSHORE ALLOWING A TROPICAL MOISTURE CONNECTION TO ADVANCE NORTHWARD. THIS MOISTURE AND THE APPROACH OF THE FRONTAL BOUNDARY AS THAT AFOREMENTIONED SHORT WAVE MERGES OVER JAMES BAY WILL SET THE STAGE FOR A POTENTIALLY ACTIVE WEATHER DAY FOR THE CWFA TUESDAY. WE WILL RETAIN THE HIGH CHANCE POPS AND NEAR OR SLIGHTLY ABOVE SEASONABLE TEMPERATURES. QUESTION REMAINS JUST HOW FAR TO THE EAST THIS FRONT WILL PROGRESS AS THE GGEM/GFS REMAIN THE SLOWEST WITH A SURFACE WAVE DEVELOPING OVER THE DELMARVA REGION WHILE THE ECMWF IS THE MOST PROGRESSIVE. ENSEMBLE APPROACH FAVORS A BLENDED MODEL SOLUTIONS SO WE WILL RETAIN AN SLIGHT CHANCE POPS BEYOND TUESDAY INTO THURSDAY WITH MORE CLOUDS THAN SUN AND AWAIT FOR FUTURE TRENDS AND CONFIDENCE. THEREAFTER...WE WILL KEEP THE WEATHER DRY FOR NOW AND TEMPERATURES BEGINNING TO CLIMB ABOVE SEASONABLE LEVELS ALONG WITH HIGHER DEWPOINTS GIVEN THE LACK OF THERMALLY ADVECTIVE CHANGES SEEN IN THE ENSEMBLES THIS MORNING. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... SCATTERED CONVECTION ASSOCIATED WITH WIND GUSTS AT OR ABOVE 30KTS HAVE DIMINISHED AND TRACKED SOUTHEAST OF THE REGION. HOWEVER...THIS WILL POSE A THREAT FOR FOG FORMATION WHERE THE RAIN HAS OCCURRED FOR KGFL/KALB/KPSF. SO HAVE INCLUDED A TEMPO GROUP AS WE WILL MONITOR TRENDS CLOSELY. OTHERWISE...A MIXTURE OF SCT-BKN MID LEVEL AC DECK ACROSS THE REGION AS QUASI-STATIONARY BOUNDARY REMAINS UPSTREAM OF THE REGION. MEANWHILE...ANOTHER ROUND OF CONVECTION WAS UNDERWAY ACROSS NORTHERN-LOWER MICHIGAN AND PORTIONS OF LOWER ONTARIO. LATEST NCEP MODEL SUITE AND HOURLY RAP SUGGEST THIS BATCH OF SHOWERS WILL IMPACT MAINLY KPOU WHERE WE WILL PLACE A DOMINANT SHRA SHORTLY AFTER SUNRISE. FOR THE OTHER TAF SITES...WE WILL PLACE A VCSH UNTIL TRENDS CAN BE SEEN. WINDS THE REMAINDER OF THE OVERNIGHT WILL REMAIN LIGHT AT SPEEDS LESS THAN 5KTS AND VARIABLE DIRECTION. THE DIRECTION BECOMES MORE WESTERLY ON SATURDAY. OUTLOOK... SAT NT...VFR...CHC MVFR WITH MIST/MIFG. SUN...VFR. CHC MVFR IN SCT -SHRA/TSRA. CHC EARLY AM MVFR/IFR WITH FOG/STRATUS POSSIBLE. MON...VFR...NO SIG WX. CHC LATE NT/EARLY AM MVFR/IFR WITH FOG/STRATUS POSSIBLE. TUE...VFR/MVFR...INCR CHC SHRA/TSRA. LATE NT/EARLY AM MVFR/IFR WITH FOG/STRATUS POSSIBLE. && .FIRE WEATHER... NO FIRE WEATHER CONCERNS ACROSS THE AREA OVER THE NEXT SEVERAL DAYS. RAIN SHOWERS WILL IMPACT THE REGION TODAY...ESP FROM THE CAPITAL REGION ON SOUTH. RH VALUES WILL BE NEAR 100 PERCENT EARLY THIS MORNING...AND WILL RETURN TO NEAR 100 PERCENT TONIGHT INTO EARLY SUNDAY MORNING AS WELL. WINDS WILL BE LIGHT AND VARIABLE TODAY AND TONIGHT. WINDS WILL BECOME SOUTHERLY ON SUNDAY AT 4-8 MPH. && .HYDROLOGY... NO SIGNFICANT HYDRO PROBLEMS ARE EXPECTED ACROSS THE REGION OVER THE NEXT FIVE DAYS. A FRONTAL BOUNDARY DRAPED ACROSS THE REGION WILL ALLOW FOR SOME SHOWERS AND ISOLATED THUNDERSTORMS TODAY. THE BEST FOCUS FOR SHOWERS WILL EXTEND FROM THE WESTERN MOHAWK VALLEY SOUTHEASTWARD ACROSS THE CATSKILLS AND TOWARDS THE MID HUDSON VALLEY. BASIN AVERAGE RAINFALL WILL ONLY BE UP TO A THIRD OF AN INCH...WHICH SHOULD HAVE LITTLE AFFECT ON AREA RIVERS AND STREAMS...ALTHOUGH A FEW SPOTS MAY LOCALLY RECEIVE SLIGHTLY HIGHER AMOUNTS OF RAINFALL. DRIER WEATHER WILL RETURN TO THE AREA FOR SUNDAY AND MONDAY...WHICH SHOULD ALLOW RIVERS TO HOLD STEADY OR SLOWLY RECEDE. 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 NEAR TERM...FRUGIS SHORT TERM...FRUGIS LONG TERM...BGM AVIATION...BGM FIRE WEATHER...FRUGIS HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
130 AM EDT SAT JUN 9 2012 .SYNOPSIS... A LOW PRESSURE SYSTEM OVER CANADA WILL DRAG A COLD FRONT THROUGH OUR REGION EARLY THIS MORNING. UNSETTLED WEATHER IS POSSIBLE LATER TODAY AS THE COLD FRONT RETURNS AS A WARM FRONT. FINALLY...A RIDGE OF HIGH PRESSURE WILL BUILD IN AND BRING DRY AND WARMER WEATHER STARTING SUNDAY. && .NEAR TERM /UNTIL 7 AM THIS MORNING/... AS OF 115 AM EDT...SHOWERS AND ISOLD TSTMS HAVE DIMINISHED OR PUSHED EAST OF MOST OF THE AREA. WILL KEEP THE THREAT FOR AN ISOLD SHOWER FOR THE BERKSHIRES/SOUTHERN VT/NORTHERN LITCHFIELD FOR THE NEXT HOUR OR SO...OTHERWISE...IT LOOKS DRY FOR THE REMAINDER OF THE OVERNIGHT HOURS. SKIES LOOK MOSTLY CLOUDY FOR MUCH OF THE AREA...WITH THE LINGERING CLOUDS FROM THE SHOWER ACTIVITY FOR EASTERN AREAS...AND MID/HIGH LEVEL CLOUDS BUILDING IN FROM THE WEST AHEAD OF THE NEXT APPROACHING IMPULSE. WILL KEEP MOSTLY CLOUDY CONDITIONS FOR THE MAJORITY OF THE REGION OVERNIGHT. HOWEVER...A FEW BREAKS ARE POSSIBLE...AND ALONG WITH YESTERDAY/S RAINFALL FOR NORTHERN AREAS...THIS WILL LEAD TO PATCHY FOG DEVELOPMENT...MAINLY TO THE NORTH OF THE MOHAWK RIVER. MIN TEMPS STILL APPEAR ON TRACK...WITH TEMPS RANGING FROM THE UPPER 40S IN THE SRN DACKS TO THE MID 50S IN THE HUDSON VALLEY. && .SHORT TERM /7 AM THIS MORNING THROUGH SUNDAY NIGHT/... THE FRONTAL BOUNDARY MOVING ACROSS THE REGION TONIGHT WILL SET UP TO THE SOUTHWEST OF THE REGION FOR SATURDAY AND SATURDAY NIGHT AS A WAVE RIPPLES ALONG THIS BOUNDARY. 12Z GFS SUGGESTS A MCS TYPE SYSTEM WILL FORM TONIGHT AND RIPPLE SOUTHEASTWARD ALONG THIS BOUNDARY SATURDAY MORNING BEFORE DYING OUT. THE 12Z NAM SHOWS MORE STRATIFORM LIKE PCPN OCCURRING ALONG AND NORTH OF THE BOUNDARY ON SATURDAY... MAINLY DURING THE AFTERNOON AND EVENING. FOR NOW HAVE FORECAST HIGH CHANCE POPS OVER THE SOUTHWEST PART OF THE FORECAST AREA... DECREASING TO SLIGHT CHANCE POPS OVER THE NORTHEAST...THEN DECREASING LATER SATURDAY NIGHT. THE UPPER LEVEL RIDGE WILL BUILD INTO THE REGION FOR SUNDAY AND SUNDAY NIGHT. MOISTURE WILL REMAIN RELATIVELY HIGH ON SUNDAY SO HAVE KEPT A SLIGHT CHANCE OF SHOWERS OR TSTMS. HIGHS SATURDAY WILL BE IN THE 70S. LOWS SATURDAY NIGHT 50 TO 60. HIGHS SUNDAY WILL BE IN THE UPPER 70S TO MID 80S. LOWS SUNDAY NIGHT IN THE 50S TO LOWER 60S. && .LONG TERM /MONDAY THROUGH FRIDAY/... MON-MON NT...UPPER LEVEL RIDGE CRESTS OVER THE REGION...WITH 500 MB HEIGHTS APPROACHING 588 DM. HOWEVER...IT IS A NARROW SPIKEY RIDGE AND SFC HIGH HIGH IS POSITIONED OFF NEW ENGLAND COAST...WITH A SOUTH/SOUTHEAST LOW LEVEL FLOW ACROSS THE REGION. SO...DESPITE WHAT OTHERWISE SHOULD BE A SUNNY AND VERY WARM DAY...THERE IS SOME POSSIBILITY OF A MARINE LAYER ADVECTING INTO REGION WITH LOW CLOUDS AND COOLER TEMPS. WE HAVE SIDED ON THE COOLER SIDE OF THINGS...WITH LOWER 80S EXPECTED IN VALLEYS FOR MAXES...AND 70S ACROSS HIGHER ELEVATIONS. HOWEVER...THERE IS SOME POSSIBILITY THAT MAXES MAY BE COOLER...ESP ACROSS PORTIONS OF THE MID HUDSON VALLEY. FOR MON NT MINS...EXPECT 50S TO LOWER 60S. ON TUESDAY A FRONT APPROACHES FROM THE WEST BRINGING MAINLY INCREASING CLOUDS. GFS HOLDS OFF PRECIPITATION UNTIL AFTER 00Z...BUT AN AFTERNOON SHOWER OR THUNDERSTORM IS POSSIBLE ESPECIALLY OVER THE HIGHER TERRAIN WEST OF THE HUDSON RIVER VALLEY. TUE NIGHT-THU...MODELS INDICATE A SLOW MOVING FRONTAL BOUNDARY. THIS SHOULD BRING SOME LOCALLY HEAVY SHOWERS TO THE REGION...MOST LIKELY TUE NT INTO WED...ALTHOUGH SOME SHOWERS COULD LINGER INTO THURSDAY. IT SHOULD BE RATHER HUMID DURING THIS PERIOD...BUT CLOUDS SHOULD LIMIT MAX TEMPS WED/THU...GENERALLY REACHING THE 70S...AFTER REACHING THE LOWER 80S ON TUE. EXPECT MILD OVERNIGHT MINS TUE NT/WED NT...GENERALLY IN THE 60S ACROSS VALLEY REGIONS...AND MID/UPPER 50S ACROSS HIGHER ELEVATIONS. THU/FRI...BOTH 12Z GFS AND 12Z EURO DEVELOP A WAVE ON THE FRONT JUST SOUTH OF NEW ENGLAND. THIS SLOWS THE FRONT DOWN AND KEEPS COOL CYCLONIC FLOW WITH CLOUDS AND LIGHT PRECIP AT LEAST INTO FRIDAY MORNING. FOR NOW SLIGHT CHANCE POPS AND SLIGHTLY WARMER AS SOME CLEARING EXPECTED LATER FRIDAY WITH COOL HIGH PRESSURE BUILDING IN FROM THE NORTH. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... SCATTERED CONVECTION ASSOCIATED WITH WIND GUSTS AT OR ABOVE 30KTS HAVE DIMINISHED AND TRACKED SOUTHEAST OF THE REGION. HOWEVER...THIS WILL POSE A THREAT FOR FOG FORMATION WHERE THE RAIN HAS OCCURRED FOR KGFL/KALB/KPSF. SO HAVE INCLUDED A TEMPO GROUP AS WE WILL MONITOR TRENDS CLOSELY. OTHERWISE...A MIXTURE OF SCT-BKN MID LEVEL AC DECK ACROSS THE REGION AS QUASI-STATIONARY BOUNDARY REMAINS UPSTREAM OF THE REGION. MEANWHILE...ANOTHER ROUND OF CONVECTION WAS UNDERWAY ACROSS NORTHERN-LOWER MICHIGAN AND PORTIONS OF LOWER ONTARIO. LATEST NCEP MODEL SUITE AND HOURLY RAP SUGGEST THIS BATCH OF SHOWERS WILL IMPACT MAINLY KPOU WHERE WE WILL PLACE A DOMINANT SHRA SHORTLY AFTER SUNRISE. FOR THE OTHER TAF SITES...WE WILL PLACE A VCSH UNTIL TRENDS CAN BE SEEN. WINDS THE REMAINDER OF THE OVERNIGHT WILL REMAIN LIGHT AT SPEEDS LESS THAN 5KTS AND VARIABLE DIRECTION. THE DIRECTION BECOMES MORE WESTERLY ON SATURDAY. OUTLOOK... SAT NT...VFR...CHC MVFR WITH MIST/MIFG. SUN...VFR. CHC MVFR IN SCT -SHRA/TSRA. CHC EARLY AM MVFR/IFR WITH FOG/STRATUS POSSIBLE. MON...VFR...NO SIG WX. CHC LATE NT/EARLY AM MVFR/IFR WITH FOG/STRATUS POSSIBLE. TUE...VFR/MVFR...INCR CHC SHRA/TSRA. LATE NT/EARLY AM MVFR/IFR WITH FOG/STRATUS POSSIBLE. && .FIRE WEATHER... A LOW PRESSURE SYSTEM WILL MOVE ACROSS SOUTHERN CANADA THIS EVENING...DRAGGING A COLD FRONT THROUGH OUR REGION TONIGHT. SCATTERED SHOWERS AND SOME THUNDERSTORMS ARE EXPECTED INTO THIS EVENING AHEAD OF THE FRONT. MORE UNSETTLED WEATHER IS EXPECTED ON SATURDAY AS A WARM FRONT CROSSES THE AREA FROM THE SOUTHWEST. FINALLY...A RIDGE OF HIGH PRESSURE WILL BUILD IN AND BRING DRY AND WARMER WEATHER STARTING SUNDAY. THERE WILL BE SCATTERED SHOWERS AND THUNDERSTORMS THIS EVENING AND AGAIN ON SATURDAY. && .HYDROLOGY... NO SIGNIFICANT HYDRO PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS OVER THE NEXT 5 DAYS. THERE WILL BE SCATTERED SHOWERS AND THUNDERSTORMS THIS EVENING AND AGAIN ON SATURDAY. WHILE BASIN AVERAGE PRECIPITATION THROUGH SATURDAY NIGHT IS EXPECTED TO BE UNDER HALF AN INCH. LOCALIZED RAINFALL AMOUNTS OF OVER AN INCH ARE POSSIBLE. DRIER WEATHER IS EXPECTED FROM SUNDAY INTO EARLY NEXT WEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...FRUGIS/GJM/JPV NEAR TERM...FRUGIS SHORT TERM...GJM LONG TERM...SND AVIATION...BGM FIRE WEATHER...GJM HYDROLOGY...GJM WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
642 AM EDT SAT JUN 9 2012 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OVER THE CAROLINAS TODAY. A VERY WEAK COOL FRONT WILL SAG SOUTH INTO NORTHERN SECTIONS OF NEW JERSEY AND PENNSYLVANIA LATER TONIGHT THEN EVENTUALLY BACK TO A WASHINGTON DC OCEAN CITY MARYLAND LINE SUNDAY EVENING. HIGH PRESSURE WILL BUILD DOWN TO THE EAST OF NEW ENGLAND EARLY NEXT WEEK. A STRONG COLD FRONT WILL APPROACH THE REGION LATER TUESDAY AND CROSS THE AREA WEDNESDAY INTO THURSDAY, FOLLOWED BY HIGH PRESSURE FOR THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MID DECK CLOUDINESS NOW OVERSPREADING MUCH OF PA AND N 3/4 OF NJ BY 15Z THEN MAY START THINNING MIDDAY. 07Z HRRR HAS SPRINKLES MODELED INTO FAR NNJ BETWEN 12Z-15Z. LIGHT WIND BECOMES W 10-15 KTS LATE THIS MORNING. NW FLOW WAA CONVECTIVE EVENT POSSIBLE LATER THIS AFTN OR EVENING. PLS SEE SWODAY1 AND ANY SWOMCD`S ETC AS WELL AS OUR DISCUSSIONS REGARDING SVR WX POTENTIAL IN OUR FCST AREA. BL MOISTURE LOOKS TO BE A LITTLE ON THE SHY SIDE WITH MODELED SFC TDS IN THE 50S AND THE ASSOCIATED ML CAPE IS GENERALLY LESS THAN 600J. NOT A GOOD SIGN FOR WIDESPREAD CONVECTION. MAX TEMPS IN SE PA ARE EXPECTED TO BE IN THE UPPER 80S... NEAR 90 IN FAR S NJ...MUCH OF DE AND MD WHERE MORE SUN. GUSTY W-WNW 15-20 KT SFC FLOW INITIALLY ACTS TO DRY AND PREVENT TSTMS BUT EVENTUALLY THERE MAY BE ENOUGH CAPE...UP TO 600J ML CAPE BY 22Z AHD OF A SWD SAGGING COOL FRONT WHICH MAY TRIGGER ISOLATED STRONG TSTMS LATE IN THE DAY. CIN COULD BE A HINDRANCE AND BOTH 12Z/8 AND OOZ/9 UK WERE DRY IN OUR FORECAST AREA. 00Z/9 GFS SVR RISK: SUFFICIENT 0-6KM BULK SHEAR OF 35 TO 40 KNOTS IS INDICATED AS WELL AS TT 48-50 WITH KI 32-36 WHICH COULD LEAD TO ISOLATED STRONG TSTMS ROLLING SEWD 25-30 KT SRN NYS THRU NE PA AND N NJ DURING THE LATE THIS AFTN OR EVENING. FAIR AMT OF 0-3KM SHEAR AS WELL NE PA AND NNJ. THE QUESTION IS...HOW MUCH CONVECTION. GFS HAS POTENTIAL FOR HEAVY CONVECTION DOWN PHL NRN SUBURBS TO ALMOST KACY THIS EVENING. MODEL GUIDANCE AND SREF HAVE POPS 20 PCT HIGHER THAN WHAT WE ARE FCST FOR PA AND NJ LATE TODAY BUT I TRIMMED TO 45 PCT MAX DUE TO MY CONCERNS ABOUT CONVECTIVE INITIATION AND RATHER DRY CANADIAN/UK MODELS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... A SECOND BATCH OF SHOWERS IS POSSIBLE TWD DAWN SUNDAY BUT PROBABLY RESTRICTED TO ONLY NNJ OR NE 1/2 NJ. OTHERWISE PARTIAL CLEARING. PATCHY FOG POSSIBLE LATE WHERE IT RAINS BUT THATS THE UNKNOWN ATTM. TEMPS/WINDS/DEWPOINTS WERE ALL 50 50 BLENDED 00Z/9 NCEP MOS GUIDANCE. SKY WAS 50 50 BLENDED GFS MOSGUIDE AND NAM RH...WHICH LOOKS PRETTY COMPARABLE TO THE 00Z/9 UK/ECMWF. CONFIDENCE IN TEMPS/SKY IS ABV AVG...BELOW AVG CONFIDENCE ON POPS. && .LONG TERM /SUNDAY THROUGH FRIDAY/... THE LONG TERM WILL BEGIN WITH AN UPPER RIDGE PROGRESSING ACROSS THE AREA. THIS WILL MEAN SUMMER-LIKE WARMTH ACROSS THE AREA...ALONG WITH THE POSSIBILITY FOR A FEW SCATTERED SHOWERS AND TSTMS. THERE IS A BETTER OPPORTUNITY FOR SHOWERS/TSTMS ON SUNDAY JUST AHEAD OF THE RIDGE WHEN SOME SHORT-WAVE ENERGY WILL BE USHERED IN ON NW UPPER FLOW ALOFT. WE HAVE KEPT MOSTLY CHC POPS ACROSS THE SRN POCONOS AND NRN NJ FOR NOW WITH SLGT CHC POPS SOUTH OF THIS ACROSS THE DELAWARE VALLEY AND ERN NJ. TEMPERATURES SUN AND MON WILL MOSTLY BE IN THE MID 80S TO LOW 90S WITH SUN LIKELY THE WARMER DAY. HIGHS ON MON ACROSS THE NORTH WILL BE ONLY IN THE LOW TO MID 80S. THE UPPER RIDGE WILL WEAKEN AND BE OFF THE COAST TUE. MOSTLY ZONAL FLOW WITH A SLIGHT TROUGH ACROSS THE EAST WILL ROUND OUT THE EXTENDED PERIOD. THIS WILL BRING WEATHER SIMILAR TO LAST WEEKS...WITH OPPORTUNITIES FOR SHOWERS/TSTMS DAILY (MOSTLY AFTERNOON AND EARLY EVENING). CHC POPS ARE IN THE GRIDS FOR MOST OF THE DAYS...THE BEST CHC ARE TIED TO WHEN THE BEST SHORT-WAVE ENERGY ARRIVES...AND MODELS DO POORLY RESOLVING THESE FEATURES THIS FAR OUT IN TIME. GENERALLY A CONTINUITY FCST WITH SOME ADJUSTMENTS TO HELP PRODUCE A CLEANER LOOKING MAP WHEN LOOKING AT NEIGHBORING OFFICES. HIGHS TUE-FRI WILL MOSTLY BE IN THE 80S WITH LOWS IN THE MID TO UPPER 60S (SOUTH) AND UPPER 50S T0 MID 60S (NORTH). && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. AFTER 12Z...VFR. CIGS AOA 8000 FT IN THE MORNING MAINLY PA AND N 3/4 NJ SHOULD THIN MIDDAY AND PERMIT SCT-BKN NEAR 6000-7000 FT IN THE AFTN. CHANCE FOR A BRIEF MVFR COND SHOWER OR TSTM IN KRDG/KABE REGION BETWEEN 21Z-23Z SPREADING SEWD TO KTTN/KPNE/KACY AREA 23Z- 02Z. IF TSTMS DEVELOP...MAY SEE ISOLATED NNW SFC GUST 30-35 KTS. TAF IS CONSERVATIVE FOR NOW. KPHL-KMIV LOOKS TO BE ON THE SRN FRINGE OF THE TSTM RISK. TONIGHT AFTER 03Z...VFR WITH PATCHY CIGS AOA 6000 FT. LOW PROB OF A SHOWER WITH TSTMS ON THE WANE AS DIURNAL HEATING DRIVER FADES. OUTLOOK... SUNDAY...MAINLY VFR CONDITIONS EXPECTED. SCATTERED SHOWERS/TSTMS DURING THE AFTERNOON AND EARLY EVENING MAY BRING LOWER CONDITIONS. MONDAY...MOSTLY VFR. TUESDAY THROUGH WEDNESDAY...MOSTLY VFR...BUT SCATTERED SHOWERS/TSTMS MOSTLY DURING THE AFTERNOON AND EARLY EVENING COULD BRING LOWER CONDITIONS. && .MARINE... CONDITIONS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA FOR OUR WATERS. WEST WINDS ARE FCST TODAY IN THE 10 TO 15 KNOT RANGE WITH GUSTS TO 20 KTS... MAINLY NEARSHORE. SEABREEZES POSSIBLE NNJ COAST LATE TODAY. SEAS OF 2 TO 3 FEET ARE EXPECTED. POSSIBLE ISOLATED TSTM LATE THIS AFTN OR EVE MAY PRODUCE REDUCED VISIBILITIES AND A NNW WIND GUST 30-35 KTS...MAINLY NNJ WATERS BUT TSTMS ARE POSSIBLE EVEN DOWN TO KACY THIS EVENING. OUTLOOK... MOSTLY SUB-SCA CONDITIONS EXPECTED. AN APPROACHING DISTURBANCE DURING THE MID-WEEK MAY BRING NEAR SCA CONDITIONS BY WED. LOW CONFID IN THIS ATTM. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...DRAG/O`HARA NEAR TERM...DRAG SHORT TERM...DRAG LONG TERM...O`HARA AVIATION...DRAG/O`HARA MARINE...DRAG/O`HARA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
641 AM EDT SAT JUN 9 2012 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OVER THE CAROLINAS TODAY. A VERY WEAK COOL FRONT WILL SAG SOUTH INTO NORTHERN SECTIONS OF NEW JERSEY AND PENNSYLVANIA LATER TONIGHT THEN EVENTUALLY BACK TO A WASHINGTON DC OCEAN CITY MARYLAND LINE SUNDAY EVENING. HIGH PRESSURE WILL BUILD DOWN TO THE EAST OF NEW ENGLAND EARLY NEXT WEEK. A STRONG COLD FRONT WILL APPROACH THE REGION LATER TUESDAY AND CROSS THE AREA WEDNESDAY INTO THURSDAY, FOLLOWED BY HIGH PRESSURE FOR THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MID DECK CLOUDINESS NOW OVERSPREADING MUCH OF PA AND N 3/4 OF NJ BY 15Z THEN MAY START THINNING MIDDAY. 07Z HRRR HAS SPRINKLES MODELED INTO FAR NNJ BETWEN 12Z-15Z. LIGHT WIND BECOMES W 10-15 KTS LATE THIS MORNING. NW FLOW WAA CONVECTIVE EVENT POSSIBLE LATER THIS AFTN OR EVENING. PLS SEE SWODAY1 AND ANY SWOMCD`S ETC AS WELL AS OUR DISCUSSIONS REGARDING SVR WX POTENTIAL IN OUR FCST AREA. BL MOISTURE LOOKS TO BE A LITTLE ON THE SHY SIDE WITH MODELED SFC TDS IN THE 50S AND THE ASSOCIATED ML CAPE IS GENERALLY LESS THAN 600J. NOT A GOOD SIGN FOR WIDESPREAD CONVECTION. MAX TEMPS IN SE PA ARE EXPECTED TO BE IN THE UPPER 80S... NEAR 90 IN FAR S NJ...MUCH OF DE AND MD WHERE MORE SUN. GUSTY W-WNW 15-20 KT SFC FLOW INITIALLY ACTS TO DRY AND PREVENT TSTMS BUT EVENTUALLY THERE MAY BE ENOUGH CAPE...UP TO 600J ML CAPE BY 22Z AHD OF A SWD SAGGING COOL FRONT WHICH MAY TRIGGER ISOLATED STRONG TSTMS LATE IN THE DAY. CIN COULD BE A HINDRANCE AND BOTH 12Z/8 AND OOZ/9 UK WERE DRY IN OUR FORECAST AREA. 00Z/9 GFS SVR RISK: SUFFICIENT 0-6KM BULK SHEAR OF 35 TO 40 KNOTS IS INDICATED AS WELL AS TT 48-50 WITH KI 32-36 WHICH COULD LEAD TO ISOLATED STRONG TSTMS ROLLING SEWD 25-30 KT SRN NYS THRU NE PA AND N NJ DURING THE LATE THIS AFTN OR EVENING. FAIR AMT OF 0-3KM SHEAR AS WELL NE PA AND NNJ. THE QUESTION IS...HOW MUCH CONVECTION. GFS HAS POTENTIAL FOR HEAVY CONVECTION DOWN PHL NRN SUBURBS TO ALMOST KACY THIS EVENING. MODEL GUIDANCE AND SREF HAVE POPS 20 PCT HIGHER THAN WHAT WE ARE FCST FOR PA AND NJ LATE TODAY BUT I TRIMMED TO 45 PCT MAX DUE TO MY CONCERNS ABOUT CONVECTIVE INITIATION AND RATHER DRY CANADIAN/UK MODELS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/... A SECOND BATCH OF SHOWERS IS POSSIBLE TWD DAWN SUNDAY BUT PROBABLY RESTRICTED TO ONLY NNJ OR NE 1/2 NJ. OTHERWISE PARTIAL CLEARING. PATCHY FOG POSSIBLE LATE WHERE IT RAINS BUT THATS THE UNKNOWN ATTM. TEMPS/WINDS/DEWPOINTS WERE ALL 50 50 BLENDED 00Z/9 NCEP MOS GUIDANCE. SKY WAS 50 50 BLENDED GFS MOSGUIDE AND NAM RH...WHICH LOOKS PRETTY COMPARABLE TO THE 00Z/9 UK/ECMWF. CONFIDENCE IN TEMPS/SKY IS ABV AVG...BELOW AVG CONFIDENCE ON POPS. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... THE LONG TERM WILL BEGIN WITH AN UPPER RIDGE PROGRESSING ACROSS THE AREA. THIS WILL MEAN SUMMER-LIKE WARMTH ACROSS THE AREA...ALONG WITH THE POSSIBILITY FOR A FEW SCATTERED SHOWERS AND TSTMS. THERE IS A BETTER OPPORTUNITY FOR SHOWERS/TSTMS ON SUNDAY JUST AHEAD OF THE RIDGE WHEN SOME SHORT-WAVE ENERGY WILL BE USHERED IN ON NW UPPER FLOW ALOFT. WE HAVE KEPT MOSTLY CHC POPS ACROSS THE SRN POCONOS AND NRN NJ FOR NOW WITH SLGT CHC POPS SOUTH OF THIS ACROSS THE DELAWARE VALLEY AND ERN NJ. TEMPERATURES SUN AND MON WILL MOSTLY BE IN THE MID 80S TO LOW 90S WITH SUN LIKELY THE WARMER DAY. HIGHS ON MON ACROSS THE NORTH WILL BE ONLY IN THE LOW TO MID 80S. THE UPPER RIDGE WILL WEAKEN AND BE OFF THE COAST TUE. MOSTLY ZONAL FLOW WITH A SLIGHT TROUGH ACROSS THE EAST WILL ROUND OUT THE EXTENDED PERIOD. THIS WILL BRING WEATHER SIMILAR TO LAST WEEKS...WITH OPPORTUNITIES FOR SHOWERS/TSTMS DAILY (MOSTLY AFTERNOON AND EARLY EVENING). CHC POPS ARE IN THE GRIDS FOR MOST OF THE DAYS...THE BEST CHC ARE TIED TO WHEN THE BEST SHORT-WAVE ENERGY ARRIVES...AND MODELS DO POORLY RESOLVING THESE FEATURES THIS FAR OUT IN TIME. GENERALLY A CONTINUITY FCST WITH SOME ADJUSTMENTS TO HELP PRODUCE A CLEANER LOOKING MAP WHEN LOOKING AT NEIGHBORING OFFICES. HIGHS TUE-FRI WILL MOSTLY BE IN THE 80S WITH LOWS IN THE MID TO UPPER 60S (SOUTH) AND UPPER 50S T0 MID 60S (NORTH). && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. AFTER 12Z...VFR. CIGS AOA 8000 FT IN THE MORNING MAINLY PA AND N 3/4 NJ SHOULD THIN MIDDAY AND PERMIT SCT-BKN NEAR 6000-7000 FT IN THE AFTN. CHANCE FOR A BRIEF MVFR COND SHOWER OR TSTM IN KRDG/KABE REGION BETWEEN 21Z-23Z SPREADING SEWD TO KTTN/KPNE/KACY AREA 23Z- 02Z. IF TSTMS DEVELOP...MAY SEE ISOLATED NNW SFC GUST 30-35 KTS. TAF IS CONSERVATIVE FOR NOW. KPHL-KMIV LOOKS TO BE ON THE SRN FRINGE OF THE TSTM RISK. TONIGHT AFTER 03Z...VFR WITH PATCHY CIGS AOA 6000 FT. LOW PROB OF A SHOWER WITH TSTMS ON THE WANE AS DIURNAL HEATING DRIVER FADES. OUTLOOK... SUNDAY...MAINLY VFR CONDITIONS EXPECTED. SCATTERED SHOWERS/TSTMS DURING THE AFTERNOON AND EARLY EVENING MAY BRING LOWER CONDITIONS. MONDAY...MOSTLY VFR. TUESDAY THROUGH WEDNESDAY...MOSTLY VFR...BUT SCATTERED SHOWERS/TSTMS MOSTLY DURING THE AFTERNOON AND EARLY EVENING COULD BRING LOWER CONDITIONS. && .MARINE... CONDITIONS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA FOR OUR WATERS. WEST WINDS ARE FCST TODAY IN THE 10 TO 15 KNOT RANGE WITH GUSTS TO 20 KTS... MAINLY NEARSHORE. SEABREEZES POSSIBLE NNJ COAST LATE TODAY. SEAS OF 2 TO 3 FEET ARE EXPECTED. POSSIBLE ISOLATED TSTM LATE THIS AFTN OR EVE MAY PRODUCE REDUCED VISIBILITIES AND A NNW WIND GUST 30-35 KTS...MAINLY NNJ WATERS BUT TSTMS ARE POSSIBLE EVEN DOWN TO KACY THIS EVENING. OUTLOOK... MOSTLY SUB-SCA CONDITIONS EXPECTED. AN APPROACHING DISTURBANCE DURING THE MID-WEEK MAY BRING NEAR SCA CONDITIONS BY WED. LOW CONFID IN THIS ATTM. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...DRAG/O`HARA NEAR TERM...DRAG SHORT TERM...DRAG LONG TERM...O`HARA AVIATION...DRAG/O`HARA MARINE...DRAG/O`HARA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
334 AM EDT SAT JUN 9 2012 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OVER THE CAROLINAS TODAY. A VERY WEAK COOL FRONT WILL SAG SOUTH INTO NORTHERN SECTIONS OF NEW JERSEY AND PENNSYLVANIA LATER TONIGHT THEN EVENTUALLY MOVE TO A WASHINGTON DC OCEAN CITY MARYLAND LINE SUNDAY EVENING. HIGH PRESSURE WILL BUILD IN FROM THE NORTH AND SLIDE TO OUR EAST ON TUESDAY. A STRONG COLD FRONT WILL APPROACH THE REGION LATER TUESDAY AND CROSS THE AREA WEDNESDAY INTO THURSDAY, FOLLOWED BY HIGH PRESSURE FOR THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FAIR WX OCNL CIRRUS EARLY THIS MORNING. THEN THE NAM MODELED MID DECK SLIDING SEWD THRU N PA WILL ARRIVE IN PTNS OF E PA BETWEEN 09Z-11Z. THE NAM AT 06Z WAS DOING A BETTER JOB WITH THIS MID DECK CLOUD THAN THE GFS. THE MID DECK OVERSPREADS MUCH OF PA AND N 3/4 OF NJ BY 15Z THEN MAY START THINNING MIDDAY. 03Z HRRR HAS SPRINKLES MODELED INTO FAR NNJ AROUND 12Z. LIGHT WIND BECOMES W 10-15 KTS LATE THIS MORNING. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... NW FLOW WAA CONVECTIVE EVENT POSSIBLE LATER THIS AFTN OR EVENING. PLS SEE SWODAY1 AND ANY SWOMCD`S ETC AS WELL AS OUR DISCUSSIONS REGARDING SVR WX POTENTIAL IN OUR FCST AREA. BL MOISTURE LOOKS TO BE A LITTLE ON THE SHY SIDE WITH MODELED SFC TDS IN THE 50S AND THE ASSOCIATED ML CAPE IS GENERALLY LESS THAN 600J. NOT A GOOD SIGN FOR WIDESPREAD CONVECTION. MAX TEMPS IN SE PA ARE EXPECTED TO BE IN THE UPPER 80S... NEAR 90 IN FAR S NJ...MUCH OF DE AND MD WHERE MORE SUN. GUSTY W-WNW 15-20 KT SFC FLOW INITIALLY ACTS TO DRY AND PREVENT TSTMS BUT EVENTUALLY THERE MAY BE ENOUGH CAPE...UP TO 600J ML CAPE BY 22Z AHD OF A SWD SAGGING COOL FRONT WHICH MAY TRIGGER ISOLATED STRONG TSTMS LATE IN THE DAY. CIN COULD BE A HINDRANCE AND BOTH 12Z/8 AND OOZ/9 UK WERE DRY IN OUR FORECAST AREA. 00Z/9 GFS SVR RISK: SUFFICIENT 0-6KM BULK SHEAR OF 35 TO 40 KNOTS IS INDICATED AS WELL AS TT 48-50 WITH KI 32-36 WHICH COULD LEAD TO ISOLATED STRONG TSTMS ROLLING SEWD 25-30 KT SRN NYS THRU NE PA AND N NJ DURING THE LATE THIS AFTN OR EVENING. FAIR AMT OF 0-3KM SHEAR AS WELL NE PA AND NNJ. THE QUESTION IS...HOW MUCH CONVECTION. GFS HAS POTENTIAL FOR HEAVY CONVECTION DOWN PHL NRN SUBURBS TO ALMOST KACY THIS EVENING. A SECOND BATCH OF SHOWERS IS POSSIBLE TWD DAWN SUNDAY BUT PROBABLY RESTRICTED TO ONLY NNJ OR NE 1/2 NJ. TEMPS/WINDS/DEWPOINTS WERE ALL 50 50 BLENDED 00Z/9 NCEP MOS GUIDANCE. SKY WAS 50 50 BLENDED GFS MOSGUIDE AND NAM RH...WHICH LOOKS PRETTY COMPARABLE TO THE 00Z/9 UK/ECMWF. CONFIDENCE IN TEMPS/SKY IS ABV AVG...BELOW AVG CONFIDENCE ON POPS. MODEL GUIDANCE AND SREF HAVE POPS 20 PCT HIGHER THAN WHAT WE ARE FCST FOR PA AND NJ LATE TODAY BUT I TRIMMED TO 45 PCT MAX DUE TO MY CONCERNS ABOUT CONVECTIVE INITIATION AND RATHER DRY CANADIAN/UK MODELS. && .LONG TERM /SUNDAY THROUGH FRIDAY/... THE LONG TERM WILL BEGIN WITH AN UPPER RIDGE PROGRESSING ACROSS THE AREA. THIS WILL MEAN SUMMER-LIKE WARMTH ACROSS THE AREA...ALONG WITH THE POSSIBILITY FOR A FEW SCATTERED SHOWERS AND TSTMS. THERE IS A BETTER OPPORTUNITY FOR SHOWERS/TSTMS ON SUNDAY JUST AHEAD OF THE RIDGE WHEN SOME SHORT-WAVE ENERGY WILL BE USHERED IN ON NW UPPER FLOW ALOFT. WE HAVE KEPT MOSTLY CHC POPS ACROSS THE SRN POCONOS AND NRN NJ FOR NOW WITH SLGT CHC POPS SOUTH OF THIS ACROSS THE DELAWARE VALLEY AND ERN NJ. TEMPERATURES SUN AND MON WILL MOSTLY BE IN THE MID 80S TO LOW 90S WITH SUN LIKELY THE WARMER DAY. HIGHS ON MON ACROSS THE NORTH WILL BE ONLY IN THE LOW TO MID 80S. THE UPPER RIDGE WILL WEAKEN AND BE OFF THE COAST TUE. MOSTLY ZONAL FLOW WITH A SLIGHT TROUGH ACROSS THE EAST WILL ROUND OUT THE EXTENDED PERIOD. THIS WILL BRING WEATHER SIMILAR TO LAST WEEKS...WITH OPPORTUNITIES FOR SHOWERS/TSTMS DAILY (MOSTLY AFTERNOON AND EARLY EVENING). CHC POPS ARE IN THE GRIDS FOR MOST OF THE DAYS...THE BEST CHC ARE TIED TO WHEN THE BEST SHORT-WAVE ENERGY ARRIVES...AND MODELS DO POORLY RESOLVING THESE FEATURES THIS FAR OUT IN TIME. GENERALLY A CONTINUITY FCST WITH SOME ADJUSTMENTS TO HELP PRODUCE A CLEANER LOOKING MAP WHEN LOOKING AT NEIGHBORING OFFICES. HIGHS TUE-FRI WILL MOSTLY BE IN THE 80S WITH LOWS IN THE MID TO UPPER 60S (SOUTH) AND UPPER 50S T0 MID 60S (NORTH). && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. THROUGH 12Z...VFR. CIRRUS. SCT-BKN DECK OF AC AOA 8000 FT WILL DEVELOP SEWD AND ARRIVE BETWEEN 09Z-11Z IN E PA. LIGHT WESTERLY WINDS WILL CONTINUE. AFTER 12Z...VFR. CIGS AOA 8000 FT IN THE MORNING SHOULD THIN MIDDAY AND PERMIT SCT-BKN NEAR 6000-7000 FT IN THE AFTN. CHANCE FOR A BRIEF MVFR COND SHOWER OR TSTM IN KRDG/KABE REGION BETWEEN 21Z-23Z SPREADING SEWD TO KTTN/KPNE/KACY AREA 23Z-02Z. IF TSTMS DEVELOP...MAY SEE ISOLATED NNW SFC GUST 30-35 KTS. KPHL-KMIV LOOKS TO BE ON THE SRN FRINGE OF THE TSTM RISK. SATURDAY NIGHT AFTER 03Z...VFR WITH PATCHY CIGS AOA 6000 FT. LOW PROB OF A SHOWER WITH TSTMS ON THE WANE AS DIURNAL HEATING DRIVER FADES. OUTLOOK... SUNDAY...MAINLY VFR CONDITIONS EXPECTED. SCATTERED SHOWERS/TSTMS DURING THE AFTERNOON AND EARLY EVENING MAY BRING LOWER CONDITIONS. MONDAY...MOSTLY VFR. TUESDAY THROUGH WEDNESDAY...MOSTLY VFR...BUT SCATTERED SHOWERS/TSTMS MOSTLY DURING THE AFTERNOON AND EARLY EVENING COULD BRING LOWER CONDITIONS. && .MARINE... CONDITIONS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA FOR OUR WATERS. WEST WINDS ARE FCST TODAY IN THE 10 TO 15 KNOT RANGE WITH GUSTS TO 20 KTS... MAINLY NEARSHORE. SEABREEZES POSSIBLE NNJ COAST LATE TODAY. SEAS OF 2 TO 3 FEET ARE EXPECTED. POSSIBLE ISOLATED TSTM LATE THIS AFTN OR EVE MAY PRODUCE REDUCED VISIBILITIES AND A NNW WIND GUST 30-35 KTS...MAINLY NNJ WATERS BUT TSTMS ARE POSSIBLE EVEN DOWN TO KACY THIS EVENING. OUTLOOK... MOSTLY SUB-SCA CONDITIONS EXPECTED. AN APPROACHING DISTURBANCE DURING THE MID-WEEK MAY BRING NEAR SCA CONDITIONS BY WED. LOW CONFID IN THIS ATTM. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...DRAG NEAR TERM...DRAG SHORT TERM...DRAG LONG TERM...O`HARA AVIATION...DRAG MARINE...DRAG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
253 AM EDT SAT JUN 9 2012 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OVER THE CAROLINAS TODAY. A VERY WEAK COOL FRONT WILL SAG SOUTH INTO NORTHERN SECTIONS OF NEW JERSEY AND PENNSYLVANIA LATER TONIGHT THEN EVENTUALLY MOVE TO A WASHINGTON DC OCEAN CITY MARYLAND LINE SUNDAY EVENING. HIGH PRESSURE WILL BUILD IN FROM THE NORTH AND SLIDE TO OUR EAST ON TUESDAY. A STRONG COLD FRONT WILL APPROACH THE REGION LATER TUESDAY AND CROSS THE AREA WEDNESDAY INTO THURSDAY, FOLLOWED BY HIGH PRESSURE FOR THE END OF THE WEEK. && .NEAR TERM /UNTIL 2 PM THIS AFTERNOON/... FAIR WX OCNL CIRRUS EARLY THIS MORNING. THEN THE NAM MODELED MID DECK SLIDING SEWD THRU N PA WILL ARRIVE IN PTNS OF E PA BETWEEN 09Z-11Z. THE NAM AT 06Z WAS DOING A BETTER JOB WITH THIS MID DECK CLOUD THAN THE GFS. THE MID DECK OVERSPREADS MUCH OF PA AND N 3/4 OF NJ BY 15Z THEN MAY START THINNING MIDDAY. 03Z HRRR HAS SPRINKLES MODELED INTO FAR NNJ AROUND 12Z. LIGHT WIND BECOMES W 10-15 KTS LATE THIS MORNING. && .SHORT TERM /2 PM THIS AFTERNOON THROUGH 6 AM SUNDAY/... NW FLOW WAA CONVECTIVE EVENT POSSIBLE LATER THIS AFTN OR EVENING. PLS SEE SWODAY1 AND ANY SWOMCD`S ETC AS WELL AS OUR DISCUSSIONS REGARDING SVR WX POTENTIAL IN OUR FCST AREA. BL MOISTURE LOOKS TO BE A LITTLE ON THE SHY SIDE WITH MODELED SFC TDS IN THE 50S AND THE ASSOCIATED ML CAPE IS GENERALLY LESS THAN 600J. NOT A GOOD SIGN FOR WIDESPREAD CONVECTION. MAX TEMPS IN SE PA ARE EXPECTED TO BE IN THE UPPER 80S... NEAR 90 IN FAR S NJ...MUCH OF DE AND MD WHERE MORE SUN. GUSTY W-WNW 15-20 KT SFC FLOW INITIALLY ACTS TO DRY AND PREVENT TSTMS BUT EVENTUALLY THERE MAY BE ENOUGH CAPE...UP TO 600J ML CAPE BY 22Z AHD OF A SWD SAGGING COOL FRONT WHICH MAY TRIGGER ISOLATED STRONG TSTMS LATE IN THE DAY. CIN COULD BE A HINDRANCE AND BOTH 12Z/8 AND OOZ/9 UK WERE DRY IN OUR FORECAST AREA. 00Z/9 GFS SVR RISK: SUFFICIENT 0-6KM BULK SHEAR OF 35 TO 40 KNOTS IS INDICATED AS WELL AS TT 48-50 WITH KI 32-36 WHICH COULD LEAD TO ISOLATED STRONG TSTMS ROLLING SEWD 25-30 KT SRN NYS THRU NE PA AND N NJ DURING THE LATE THIS AFTN OR EVENING. FAIR AMT OF 0-3KM SHEAR AS WELL NE PA AND NNJ. THE QUESTION IS...HOW MUCH CONVECTION. GFS HAS POTENTIAL FOR HEAVY CONVECTION DOWN PHL NRN SUBURBS TO ALMOST KACY THIS EVENING. A SECOND BATCH OF SHOWERS IS POSSIBLE TWD DAWN SUNDAY BUT PROBABLY RESTRICTED TO ONLY NNJ OR NE 1/2 NJ. TEMPS/WINDS/DEWPOINTS WERE ALL 50 50 BLENDED 00Z/9 NCEP MOS GUIDANCE. SKY WAS 50 50 BLENDED GFS MOSGUIDE AND NAM RH...WHICH LOOKS PRETTY COMPARABLE TO THE 00Z/9 UK/ECMWF. CONFIDENCE IN TEMPS/SKY IS ABV AVG...BELOW AVG CONFIDENCE ON POPS. MODEL GUIDANCE AND SREF HAVE POPS 20 PCT HIGHER THAN WHAT WE ARE FCST FOR PA AND NJ LATE TODAY BUT I TRIMMED TO 45 PCT MAX DUE TO MY CONCERNS ABOUT CONVECTIVE INITIATION AND RATHER DRY CANADIAN/UK MODELS. && .LONG TERM /SUNDAY THROUGH FRIDAY/... SEVERAL FEATURES WILL IMPACT THE WX DURG THE EXTENDD PD. A RIDGE BUILDS OVER THE REGION AT THE SFC AND ALOFT AND EXPECT A HOT AND GENLY DRY DAY FOR SUNDAY. HOWEVER, AS IS OFTEN THE CASE WITH THESE KIND OF DAYS IN THE SUMMER, SOME DIURNAL SHOWERS AND TSTMS ARE POSSIBLE, BUT ATTM THERE ARE NO SIG FEATURES MOVG ACRS TO ACT AS A FOCUS OF CONVECTION, SO OVERALL POPS SHOULD BE LOW. THE HIGH REMAINS IN PLACE SUNDAY NIGHT INTO MONDAY WITH MAINLY AFTN SHOWERS AND STORMS POSSIBLE AGAIN. BY MONDAY NIGHT INTO TUESDAY, A STRONG CDFNT EXTEND SWD ACRS THE MIDWEST FROM A LOW NR HUDSON BAY WILL BE MAKING ITS WAY EWD. THIS CDFNT WILL CAUSE AN INCREASE IN SLY FLOW AHEAD OF IT ON TUESDAY AND POPS WILL RISE THRU THE DAY AS WELL. TUESDAY NIGHT INTO WEDNESDAY LOOK TO BE THE WETTEST PD ATTM WITH THE FROPA AND PSBLY A LOW FORMING ALG THE FRONT. HAVE INCREASED POPS DURG THE TUE/WED TIME FRAME AND WILL LIKELY NEED TO FURTHER DO SO IN SUBSEQUENT FCSTS. THE FRONT CLEARS THE AREA ON THURSDAY AND CONDS SHOULD IMPROVE, BUT THERE IS STILL SOME LINGERING TROUGHINESS AND INSTABILITY ALOFT FOR SOME MAINLY DIURNAL SHOWERS/STORMS. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. THROUGH 12Z...VFR. CIRRUS. SCT-BKN DECK OF AC AOA 8000 FT WILL DEVELOP SEWD AND ARRIVE BETWEEN 09Z-11Z IN E PA. LIGHT WESTERLY WINDS WILL CONTINUE. AFTER 12Z...VFR. CIGS AOA 8000 FT IN THE MORNING SHOULD THIN MIDDAY AND PERMIT SCT-BKN NEAR 6000-7000 FT IN THE AFTN. CHANCE FOR A BRIEF MVFR COND SHOWER OR TSTM IN KRDG/KABE REGION BETWEEN 21Z-23Z SPREADING SEWD TO KTTN/KPNE/KACY AREA 23Z-02Z. IF TSTMS DEVELOP...MAY SEE ISOLATED NNW SFC GUST 30-35 KTS. KPHL-KMIV LOOKS TO BE ON THE SRN FRINGE OF THE TSTM RISK. SATURDAY NIGHT AFTER 03Z...VFR WITH PATCHY CIGS AOA 6000 FT. LOW PROB OF A SHOWER WITH TSTMS ON THE WANE AS DIURNAL HEATING DRIVER FADES. OUTLOOK... SUNDAY...MAINLY VFR CONDITIONS EXPECTED. SHOWERS AND THUNDERSTORM MAY DEVELOP ACROSS OUR AREA AS A COLD FRONT MOVES THRU. OVERALL POPS ARE LOW. MONDAY...VFR CONDITIONS ARE EXPECTED WITH A CHANCE FOR SOME MVFR CEILINGS TO OCCUR AS AN ONSHORE FLOW DEVELOPS. TUESDAY...VFR CONDITIONS EXPECTED EARLY WITH A CHANCE FOR SHOWERS AND THUNDERSTORMS, MAINLY WEST OF KPHL, IN THE AFTERNOON AND EVENING. LOWERING CIGS AND VSBYS DURG THE EVENING. TUESDAY NIGHT/WEDNESDAY...MVFR OR LOWER CIGS/VSBYS TUESDAY NIGHT AS PERIODS OF RAIN AND SOME THUNDERSTORMS OVERSPREAD THE REGION. SOME RAIN COULD BE HEAVY AT TIMES. && .MARINE... CONDITIONS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA FOR OUR WATERS. WEST WINDS ARE FCST TODAY IN THE 10 TO 15 KNOT RANGE WITH GUSTS TO 20 KTS... MAINLY NEARSHORE. SEABREEZES POSSIBLE NNJ COAST LATE TODAY. SEAS OF 2 TO 3 FEET ARE EXPECTED. POSSIBLE ISOLATED TSTM LATE THIS AFTN OR EVE MAY PRODUCE REDUCED VISIBILITIES AND A NNW WIND GUST 30-35 KTS...MAINLY NNJ WATERS BUT TSTMS ARE POSSIBLE EVEN DOWN TO KACY THIS EVENING. OUTLOOK... HIGH PRESSURE WILL BE OVER THE COASTAL WATERS AT THE START OF THE PD AND EXPECT SUB ADVISORY CONDS THRU ABOUT TUESDAY. THEN E TO SELY AND EVENTUALLY SLY FLOW WILL INCREASE ASA CDFNT APPROACHES FROM THE MIDWEST. BY LATER TUE OR WED SEAS WILL RESPOND AND AT SOME POINT DUR THIS TIME FRAME SCA FLAGS MAY BE NEEDED. THE FRONT WILL CLEAR THE AREA ON THURSDAY. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...NIERENBERG NEAR TERM...DRAG SHORT TERM...DRAG LONG TERM...NIERENBERG AVIATION...DRAG/NIERENBERG MARINE...DRAG/NIERENBERG
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
452 PM EDT Sat Jun 9 2012 .MESOSCALE UPDATE... We have issued a Flash Flood Watch for Walton, Holmes, Washington, and Bay Counties in the Florida Panhandle, valid until 19z Sunday. The last several runs of the RAP have consistently indicated that 850mb moisture transport vectors will be increasing in magnitude in the next few hours, and focusing into the aforementioned zones. Earlier today, thunderstorm activity was focused near the coast to the west of us (around PNS and MOB) - anchored in place near the nose of low-level moisture transport maximum and in the coastal convergence zone. Abundant moisture (analyzed and GOES-satellite observed PWATS around 2.1-2.2") and high freezing levels and WBZ heights should lead to highly efficient thunderstorms and rain bands. If things continue to progress as they have all day, we may start seeing heavier rain rates persist near or south of I-10 from Panama City west in the 21-03z timeframe (next 6 hrs). && .SYNOPSIS... Radar indicates sct shwrs and isold storms over land. It also shows a large area of rain with embedded storms over waters will onshore SW-NE later today into tonight. A few of these marine storms may generate a brief waterspout or a tornado. AT UPPER LEVELS... The large scale longwave pattern is highlighted in Nrn stream by trough over Wrn states, ridge over Cntrl and Ern states and trough across extreme Wrn Atlc. Srn stream highlighted by weak troughing West Coast and Desert SW, ridging Srn Plains, trough/low over Wrn Gulf and ridge over Ern states to extreme Wrn Atlc. Of particular local concern is upper low that continues to spin over the upper TX coast/Wrn Gulf of Mex. Ahead of this low, WAA/moisture transport will increase thru the period as a very moist S/SW flow continues to spread plume of deep layer Gulf moisture N/NE across the Gulf. The 12Z KTAE sounding showed the PW was 2.10 inches. Low is forecast to open up into a short wave trough towards LWR MS Valley beginning tonight while weak H5 impulse slowly meanders NEWD. Both begin phasing with energy moving Ewd across the Nrn Plains Sun night. System then inches slowly EWD into OH Valley and weakens some further phasing with energy moving ewd over Mid MS Valley and upper Midwest on Monday with trough axis from TN Valley to over our extreme WRN zones by afternoon with an enhancement of deep onshore flow downstream of system. On Tues, trough axis lifts NEWD with axis across extreme NE Gulf states with deeper moisture lifting accordingly before axis exits to adjacent Atlc before sundown. AT LOWER LEVELS... The local area remains between high centered off the Carolina coast with ridge swd along Ern seaboard down to Cuba and a trough of low pressure over the WRN Gulf. A quasi-stationary front extends W-E from low TX/LA coast ESE across N FL. These features are acting in concert to pull moisture rich tropical air northward into the region. The low level flow/WAA will continue to strengthen is association with above elongating upper low/trough and the short term promises to be a washout. The front is expected to lift WNW-ESE and N of FL/GA/AL line overnight with increasing CWA in warm sector. Abundant moisture and lift will continue to generate numerous showers and isolated thunderstorms, especially over the Panhandle and adjacent waters. Beyond tonight, the warm front will pivot progressively NNE of the area becoming increasingly absorbed by synoptic scale SLY flow. On Monday into Tuesday, frontal remnant lifts into S/Cntrl GA and weakens as it comes into contact with sagging SE High and POPs begin to slowly decrease from S-N. Still, CWA remains on E or wet side of upper trough axis with high PWATS. i.e. Panama City GFS model sounding shows above 2 inches of PWAT until Mon morning and over 1.75 inches thru Tues. New HI RES guidance keeps us socked in thru its total run of 36hrs. So high POPs and locally heavy rainfall a good bet thru period. Mid-Level lapse rates/shear will not be impressive during these periods. Nevertheless, with high CAPE values and moist low boundary layer and enhanced low level shear near warm front may support low level storm rotation. So we could see isolated strong to severe storms with damaging winds and perhaps a tornado or waterspout tonight into Sunday. && .SHORT TERM (This Evening through Tuesday)... NAM run not available so forecast focused on GFS model. Tonight...Very moist air aided by isentropic lift with PW well over 2 inches is forecast to push north across the region as the boundary gradually lifts north as a warm front. The deep layer trough to the west will drift slowly northeast and there will be some DPVA to enhance lift as well. 70-50% NW-SE POP gradient. Widespread 1 to 2 inch rainfall totals are forecast thru sunrise. Highest rainfall totals are expected to be south and west of Tallahassee. Because the large area of rain is likely to be ongoing along and north of the front, any supercells that develop will probably become quickly elevated as they move inland, greatly reducing the tornado threat inland. CWA will be monitored in case a flood watch is necessary. Lows around 70. Sunday...80-50% NW-SE POP gradient. We are still seeing a swell component in the buoy data and there have been a couple of fatalities in the surf this week. With the beach agencies continuing to report hazardous conditions, a high risk of rip currents remains possible. Highs mid-upper 80s. Monday...60-30% N-SE POP gradient daytime, 50-30% at night. Highs 85 coast to 90 S/Cntrl Ga. Lows around 70 inland to mid 70s coast. Tuesday...50-40% N-SE POP gradient. Highs upper 80s coast to 90 inland. && .LONG TERM (Tuesday night through next Saturday)... The extended range forecast is based heavily on the ECMWF. POPs will be a concern for the entirety of the long term as a frontal boundary approaches the forecast area and then stalls out. This will bring rainy conditions with a chance of thunderstorms each day. && .MARINE... The gradient is forecast to remain tight with local area in between ridging along east coast and low over wrn gulf. this low is forecast to build north and tighten local gradient. Winds and seas are expected to reach exercise caution levels west of Apalachicola into Sunday. A ridge of high pressure will build over the waters early next week allowing winds and seas to return to more seasonable levels. The onshore winds will veer to the west by Wednesday as a front approaches from the north. && .HYDROLOGY...Blend of GFS/EURO AND UKMET show widespread 1 to 2.5 inches with isold 4 inches thru 24 hrs. Expect total event rainfall totals to range from 2 to 4 inches areawide with locally higher amounts possible. A widespread flooding event is not anticipated, however urban areas may experience minor flooding over the next few days. Still there is a possibility that locations especially along the FL Panhandle could get multiple rounds of heavy rain where the best threat of flooding is expected and this area will be closely monitored. && .AVIATION... MVFR conditions are likely across the area as a warm front lifts northward and brings moist tropical conditions into the area. Rain with some embedded thunder is expected to affect all TAF sites at various points through the period. Brief reductions to IFR are expected with any thunderstorms. && .FIRE WEATHER... Red flag criteria will not be met over the next week as relative humidity values remain well above critical levels. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 71 88 73 90 72 / 70 70 40 50 40 Panama City 73 85 75 85 74 / 70 70 40 50 40 Dothan 71 85 72 86 71 / 70 80 50 60 40 Albany 71 86 71 87 71 / 70 70 60 60 50 Valdosta 70 88 71 90 71 / 60 60 50 50 30 Cross City 72 89 72 90 71 / 50 50 30 30 30 Apalachicola 73 85 76 85 75 / 70 70 30 40 30 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...None. GA...None. FL...Flash Flood Watch through Sunday afternoon for Central Walton- Coastal Bay-Holmes-Inland Bay-Inland Walton-South Walton- Washington. High Risk Rip Currents through Sunday afternoon for coastal Walton and coastal Bay Counties. GM...None. && $$ Mesoscale Update...Lamers Synopsis & Short Term...Block Long Term...Harrigan/LV Aviation...DVD Marine...Block Fire Weather...DVD
AREA FORECAST DISCUSSION
NWS MIAMI FL
130 PM EDT SAT JUN 9 2012 .AVIATION...HEAVY CLOUD COVER EARLIER THIS MORNING HELD BACK DIURNAL HEATING CYCLE AND TCU JUST BEGINNING TO DEVELOP ACROSS S FL AT 17Z. SHORT TERM MODELS HAVE ALSO BECOME LESS CONFIDENT OF CONVECTION INITIATION PRIOR TO AROUND 18-19Z SO DELAYED VCTS IN THE TAFS FOR THESE REASONS. ALSO TOOK OUT MENTION OF THEM FOR THE KTMB TERMINAL AS THE CELLS SHOULD BE WELL NORTH AS THE AFTERNOON PROGRESSES AND COULD EVEN BE NORTH OF THE KMIA AND KOPF TERMINALS. LIGHT FLOW HAS ALLOWED SEA BREEZES ALONG BOTH COASTS AND THIS WILL CONTINUE UNTIL AROUND 00-01Z THIS EVENING. KOB && .PREV DISCUSSION... /ISSUED 950 AM EDT SAT JUN 9 2012/ DISCUSSION... SHOWERS CONTINUE TO PUSH WELL OFFSHORE THE ATLANTIC COAST THIS MORNING LEAVING SOUTH FLORIDA UNDER PARTLY TO MOSTLY CLOUDY SKIES. LATEST HRRR SHOWS AFTERNOON CONVECTION FLARING UP AGAIN WITH THE ONSET OF THE EAST COAST SEA BREEZE AND IS IN GOOD AGREEMENT WITH THE ONGOING FORECAST. OTHER FORECAST PARAMETERS LOOK GOOD AS WELL SO NO UPDATES ARE PLANNED ATTM. PREV DISCUSSION... /ISSUED 732 AM EDT SAT JUN 9 2012/ AVIATION...SOME -RA PSBL E COAST TERMINALS THRU 14Z BUT VFR CONDS XPCTD. BUT BY 18Z...TSRA DVLPG IN THE INTERIOR OF S FLA WL MOV E AND AFFECT THE E COAST TERMINALS ESPECIALLY FM KFLL TO KPBI. ONLY VCTS IN ALL E COAST TAFS ATTM. CRRNT SFC WNDS CALM TO VRY LGT SE BCMG AFT 14Z SE 8-12 KTS ALL TERMINALS. AT KAPF...VFR THRU PD WITH ISOLD SHRA INVOF KAPF BUT VCSH NOT IN TAFS ATTM. ANY SHRA/TSRA THAT DVLP AFT 16Z SHUD BE E OF TERMINAL REMAINDER OF PD. CRRNT WND E < 10 KTS BCMG AFT 18Z SSW-W ARND 10 KTS AS W COAST SEA BREEZE DVLPS. PREV DISCUSSION... /ISSUED 432 AM EDT SAT JUN 9 2012/ AVIATION...SVR WX ON THE W COAST DELAYED THIS ISSUANCE. A LINE OF WEAKENING SHRA/TSRA MOVG E ACRS THE INTERIOR OF S FLA WL BRING SHRA TO THE E COAST TERMINALS THRU 14Z. SOME MVFR CIG/VSBY PSBL. AFT 14Z WDSPRD VFR CONDS XPCTD BUT BY 18Z...TSRA DVLPG IN THE INTERIOR OF S FLA WL MOV E AND AFFECT THE E COAST TERMINALS. ONLY VCTS IN TAFS ATTM. CRRNT SFC WNDS CALM TO VRY LGT SE BCMG AFT 14Z SE 8-12 KTS ALL TERMINALS. AT KAPF...VFR THRU PD WITH ISOLD SHRA INVOF KAPF THRU 12Z. ANY SHRA/TSRA THAT DVLP SHUD BE E OF TERMINAL REMAINDER OF PD. CRRNT WND SE ARND 10 KTS BCMG AFT 18Z SSW-W ARND 10 KTS AS W COAST SEA BREEZE DVLPS. PREV DISCUSSION... /ISSUED 408 AM EDT SAT JUN 9 2012/ SEVERE THUNDERSTORM WATCH IN EFFECT THROUGH 8 AM THIS MORNING... DISCUSSION... SHORTWAVE MOVING ACROSS CENTRAL FLORIDA EARLY THIS MORNING...BRINGING A LARGE SHIELD OF SHOWERS AND EMBEDDED THUNDERSTORMS WITH IT ACROSS THE REGION. A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT FOR ALL OF SOUTH FLORIDA THROUGH 8 AM...AND THE NEARSHORE WATERS OF THE GULF AND ATLANTIC...INCLUDING BISCAYNE BAY AND LAKE OKEECHOBEE. THE GLOBAL MODELS QUICKLY DISSIPATED THIS AREA OF STORMS...AND THEN TREND SEEMS TO BE DOWN OVER THE PAST HOUR OR SO. WATER VAPOR IMAGERY AND ANALYSIS THIS MORNING SHOWED A LARGE UPPER TROUGH DIGGING INTO THE PACIFIC NORTHWEST...AN UPPER RIDGE ACROSS THE MIDDLE OF THE COUNTRY...AND AN UPPER TROUGH OFF THE EAST COAST. A WEAK UPPER LOW WAS ACROSS THE NORTHWEST GULF AND A WEAK SHORTWAVE WAS MOVING ACROSS THE FLORIDA PENINSULA. ANOTHER UPPER HIGH WAS LOCATED ACROSS THE NORTHWEST CARIBBEAN AND FLORIDA STRAITS INTO THE WESTERN ATLANTIC. AS THE UPPER TROUGH DIGS FURTHER TO THE SOUTHEAST TODAY...THE UPPER LOW ACROSS THE NORTHWEST GULF WILL GET PUSHED TO THE NORTHEAST. AT THE SURFACE...HIGH PRESSURE ACROSS THE CAROLINAS AND WESTERN ATLANTIC WILL ALSO PUSH EASTWARD FURTHER INTO THE WESTERN ATLANTIC...WITH A LIGHT EAST TO SOUTHEAST FLOW EXPECTED ACROSS THE REGION THROUGH EARLY NEXT WEEK. A WEAK FRONTAL BOUNDARY REMAINED ACROSS NORTH CENTRAL FLORIDA...AND THIS FEATURE WILL SLOWLY DRIFT SOUTH AND WASH OUT TO THE NORTH OF THE LAKE TODAY. THE WEAK SHORTWAVE WILL MOVE ACROSS CENTRAL FLORIDA THIS MORNING AND INTO THE WESTERN ATLANTIC...WITH MID/UPPER HEIGHTS RISING IN ITS WAKE. THE SHOWER AND THUNDERSTORM ACTIVITY MAY VERY WELL STABILIZE THE REGION FOR MUCH OF TODAY. HOWEVER...PWATS AROUND 2 INCHES WILL REMAIN OVER THE REGION AND SEA BREEZE BOUNDARIES MAY FORCE CONVECTION ESPECIALLY AS TEMPERATURES RISE INTO THE LOW TO MID 90S. ANY THUNDERSTORMS THIS AFTERNOON WILL BE VERY SLOW MOVING...AND HEAVY RAIN WILL BE POSSIBLE WHERE THE STORMS SET UP. KEPT HIGHER POPS FOR THE EAST COAST THIS MORNING DUE TO THE SHOWERS MOVING EAST. OTHERWISE...HAVE LIKELY POPS ACROSS THE INTERIOR WHERE SEA BREEZE BOUNDARIES ARE LIKELY TO COLLIDED AND LOW END CHANCE FOR THE EAST AND WEST COASTS. THE UPPER RIDGE ACROSS THE CARIBBEAN AND FLORIDA STRAITS WILL BEGIN TO PUSH NORTHWARD...WITH RISING HEIGHTS EXPECTED THROUGH THE WEEKEND AND INTO THE BEGINNING OF NEXT WEEK ACROSS SOUTH FLORIDA. 500MB HEIGHTS ARE EXPECTED TO AVERAGE AROUND 591-592 DAM. THIS WILL IMPART A TRYING TREND ACROSS THE REGION BEGINNING SUNDAY AND ESPECIALLY MONDAY AND TUESDAY. SO TEMPERATURES WILL BE WARM...ESPECIALLY ACROSS THE INTERIOR AND GULF COAST...AND HEAT INDICES MAY REACH 105 TO 110F IN COLLIER COUNTY ON SUNDAY AND MONDAY. THE UPPER LOW THAT WAS ACROSS THE NORTHWEST GULF WILL SLIDE SLOWLY TO THE EAST AND OPEN UP INTO A WEAK TROUGH ACROSS THE NORTHERN GULF COAST. AS IT SLIDES TOWARDS FLORIDA ON TUESDAY...THE UPPER RIDGE WILL MOVE TO THE WEST. SO HIGH TEMPERATURES SHOULD COOL OFF A FEW DEGREES ACROSS THE INTERIOR AND WEST. THIS WEAK TROUGH WILL REMAIN ACROSS NORTHERN FLORIDA THROUGH THE END OF THE PERIOD. SO MORE TYPICAL AFTERNOON SHOWERS AND THUNDERSTORMS CAN BE EXPECTED WEDNESDAY AND THURSDAY. MARINE... EASTERLY WINDS WILL REMAIN BELOW 15 KNOTS THROUGH THIS WEEKEND OVER ALL THE LOCAL WATERS. THE SEAS WILL ALSO REMAIN AT 3 FEET OR LESS OVER BOTH THE ATLANTIC AND GULF WATERS THROUGH THIS WEEKEND. SO BOATING CONDITIONS SHOULD BE GOOD OUTSIDE OF ANY SHOWERS OR THUNDERSTORMS THIS WEEKEND. FIRE WEATHER... MINIMUM RELATIVE HUMIDITIES WILL REMAIN WELL ABOVE CRITICAL LEVELS THROUGH THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 75 88 76 87 / 30 30 10 10 FORT LAUDERDALE 77 89 77 88 / 30 30 10 10 MIAMI 78 90 77 89 / 30 30 10 10 NAPLES 77 91 76 92 / 20 30 20 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS MIAMI FL
950 AM EDT SAT JUN 9 2012 .DISCUSSION... SHOWERS CONTINUE TO PUSH WELL OFFSHORE THE ATLANTIC COAST THIS MORNING LEAVING SOUTH FLORIDA UNDER PARTLY TO MOSTLY CLOUDY SKIES. LATEST HRRR SHOWS AFTERNOON CONVECTION FLARING UP AGAIN WITH THE ONSET OF THE EAST COAST SEA BREEZE AND IS IN GOOD AGREEMENT WITH THE ONGOING FORECAST. OTHER FORECAST PARAMETERS LOOK GOOD AS WELL SO NO UPDATES ARE PLANNED ATTM. && .PREV DISCUSSION... /ISSUED 732 AM EDT SAT JUN 9 2012/ AVIATION...SOME -RA PSBL E COAST TERMINALS THRU 14Z BUT VFR CONDS XPCTD. BUT BY 18Z...TSRA DVLPG IN THE INTERIOR OF S FLA WL MOV E AND AFFECT THE E COAST TERMINALS ESPECIALLY FM KFLL TO KPBI. ONLY VCTS IN ALL E COAST TAFS ATTM. CRRNT SFC WNDS CALM TO VRY LGT SE BCMG AFT 14Z SE 8-12 KTS ALL TERMINALS. AT KAPF...VFR THRU PD WITH ISOLD SHRA INVOF KAPF BUT VCSH NOT IN TAFS ATTM. ANY SHRA/TSRA THAT DVLP AFT 16Z SHUD BE E OF TERMINAL REMAINDER OF PD. CRRNT WND E < 10 KTS BCMG AFT 18Z SSW-W ARND 10 KTS AS W COAST SEA BREEZE DVLPS. PREV DISCUSSION... /ISSUED 432 AM EDT SAT JUN 9 2012/ AVIATION...SVR WX ON THE W COAST DELAYED THIS ISSUANCE. A LINE OF WEAKENING SHRA/TSRA MOVG E ACRS THE INTERIOR OF S FLA WL BRING SHRA TO THE E COAST TERMINALS THRU 14Z. SOME MVFR CIG/VSBY PSBL. AFT 14Z WDSPRD VFR CONDS XPCTD BUT BY 18Z...TSRA DVLPG IN THE INTERIOR OF S FLA WL MOV E AND AFFECT THE E COAST TERMINALS. ONLY VCTS IN TAFS ATTM. CRRNT SFC WNDS CALM TO VRY LGT SE BCMG AFT 14Z SE 8-12 KTS ALL TERMINALS. AT KAPF...VFR THRU PD WITH ISOLD SHRA INVOF KAPF THRU 12Z. ANY SHRA/TSRA THAT DVLP SHUD BE E OF TERMINAL REMAINDER OF PD. CRRNT WND SE ARND 10 KTS BCMG AFT 18Z SSW-W ARND 10 KTS AS W COAST SEA BREEZE DVLPS. PREV DISCUSSION... /ISSUED 408 AM EDT SAT JUN 9 2012/ SEVERE THUNDERSTORM WATCH IN EFFECT THROUGH 8 AM THIS MORNING... DISCUSSION... SHORTWAVE MOVING ACROSS CENTRAL FLORIDA EARLY THIS MORNING...BRINGING A LARGE SHIELD OF SHOWERS AND EMBEDDED THUNDERSTORMS WITH IT ACROSS THE REGION. A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT FOR ALL OF SOUTH FLORIDA THROUGH 8 AM...AND THE NEARSHORE WATERS OF THE GULF AND ATLANTIC...INCLUDING BISCAYNE BAY AND LAKE OKEECHOBEE. THE GLOBAL MODELS QUICKLY DISSIPATED THIS AREA OF STORMS...AND THEN TREND SEEMS TO BE DOWN OVER THE PAST HOUR OR SO. WATER VAPOR IMAGERY AND ANALYSIS THIS MORNING SHOWED A LARGE UPPER TROUGH DIGGING INTO THE PACIFIC NORTHWEST...AN UPPER RIDGE ACROSS THE MIDDLE OF THE COUNTRY...AND AN UPPER TROUGH OFF THE EAST COAST. A WEAK UPPER LOW WAS ACROSS THE NORTHWEST GULF AND A WEAK SHORTWAVE WAS MOVING ACROSS THE FLORIDA PENINSULA. ANOTHER UPPER HIGH WAS LOCATED ACROSS THE NORTHWEST CARIBBEAN AND FLORIDA STRAITS INTO THE WESTERN ATLANTIC. AS THE UPPER TROUGH DIGS FURTHER TO THE SOUTHEAST TODAY...THE UPPER LOW ACROSS THE NORTHWEST GULF WILL GET PUSHED TO THE NORTHEAST. AT THE SURFACE...HIGH PRESSURE ACROSS THE CAROLINAS AND WESTERN ATLANTIC WILL ALSO PUSH EASTWARD FURTHER INTO THE WESTERN ATLANTIC...WITH A LIGHT EAST TO SOUTHEAST FLOW EXPECTED ACROSS THE REGION THROUGH EARLY NEXT WEEK. A WEAK FRONTAL BOUNDARY REMAINED ACROSS NORTH CENTRAL FLORIDA...AND THIS FEATURE WILL SLOWLY DRIFT SOUTH AND WASH OUT TO THE NORTH OF THE LAKE TODAY. THE WEAK SHORTWAVE WILL MOVE ACROSS CENTRAL FLORIDA THIS MORNING AND INTO THE WESTERN ATLANTIC...WITH MID/UPPER HEIGHTS RISING IN ITS WAKE. THE SHOWER AND THUNDERSTORM ACTIVITY MAY VERY WELL STABILIZE THE REGION FOR MUCH OF TODAY. HOWEVER...PWATS AROUND 2 INCHES WILL REMAIN OVER THE REGION AND SEA BREEZE BOUNDARIES MAY FORCE CONVECTION ESPECIALLY AS TEMPERATURES RISE INTO THE LOW TO MID 90S. ANY THUNDERSTORMS THIS AFTERNOON WILL BE VERY SLOW MOVING...AND HEAVY RAIN WILL BE POSSIBLE WHERE THE STORMS SET UP. KEPT HIGHER POPS FOR THE EAST COAST THIS MORNING DUE TO THE SHOWERS MOVING EAST. OTHERWISE...HAVE LIKELY POPS ACROSS THE INTERIOR WHERE SEA BREEZE BOUNDARIES ARE LIKELY TO COLLIDED AND LOW END CHANCE FOR THE EAST AND WEST COASTS. THE UPPER RIDGE ACROSS THE CARIBBEAN AND FLORIDA STRAITS WILL BEGIN TO PUSH NORTHWARD...WITH RISING HEIGHTS EXPECTED THROUGH THE WEEKEND AND INTO THE BEGINNING OF NEXT WEEK ACROSS SOUTH FLORIDA. 500MB HEIGHTS ARE EXPECTED TO AVERAGE AROUND 591-592 DAM. THIS WILL IMPART A TRYING TREND ACROSS THE REGION BEGINNING SUNDAY AND ESPECIALLY MONDAY AND TUESDAY. SO TEMPERATURES WILL BE WARM...ESPECIALLY ACROSS THE INTERIOR AND GULF COAST...AND HEAT INDICES MAY REACH 105 TO 110F IN COLLIER COUNTY ON SUNDAY AND MONDAY. THE UPPER LOW THAT WAS ACROSS THE NORTHWEST GULF WILL SLIDE SLOWLY TO THE EAST AND OPEN UP INTO A WEAK TROUGH ACROSS THE NORTHERN GULF COAST. AS IT SLIDES TOWARDS FLORIDA ON TUESDAY...THE UPPER RIDGE WILL MOVE TO THE WEST. SO HIGH TEMPERATURES SHOULD COOL OFF A FEW DEGREES ACROSS THE INTERIOR AND WEST. THIS WEAK TROUGH WILL REMAIN ACROSS NORTHERN FLORIDA THROUGH THE END OF THE PERIOD. SO MORE TYPICAL AFTERNOON SHOWERS AND THUNDERSTORMS CAN BE EXPECTED WEDNESDAY AND THURSDAY. MARINE... EASTERLY WINDS WILL REMAIN BELOW 15 KNOTS THROUGH THIS WEEKEND OVER ALL THE LOCAL WATERS. THE SEAS WILL ALSO REMAIN AT 3 FEET OR LESS OVER BOTH THE ATLANTIC AND GULF WATERS THROUGH THIS WEEKEND. SO BOATING CONDITIONS SHOULD BE GOOD OUTSIDE OF ANY SHOWERS OR THUNDERSTORMS THIS WEEKEND. FIRE WEATHER... MINIMUM RELATIVE HUMIDITIES WILL REMAIN WELL ABOVE CRITICAL LEVELS THROUGH THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 88 75 88 76 / 50 30 30 10 FORT LAUDERDALE 89 77 89 77 / 30 30 30 10 MIAMI 90 78 90 77 / 30 30 30 10 NAPLES 89 77 91 76 / 30 20 30 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...10/CD AVIATION/RADAR...30/KOB
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1000 PM CDT SUN JUN 10 2012 .DISCUSSION... 929 PM CDT SOME MINOR CHANGES MADE TO ARRIVAL TIMING OF POPS FOR MONDAY MORNING...OTHERWISE NO REAL CHANGES MADE TO GOING FORECAST FOR TONIGHT INTO MONDAY. EXPANSIVE UPPER LEVEL LOW AND ASSOCIATED HIGH PWAT AIR...AS SEEN ON WATER VAPOR...IS EXPANDING NORTHWARD. A WEAK UPPER LEVEL WAVE IN SOUTHWEST IL THIS EVE HAS HELPED TO SPREAD THIS NORTH CAUSING AN EXPANSION IN HIGH CLOUDS ACROSS THE AREA...WHICH SHOULD CONTINUE INTO OVERNIGHT. THESE CLOUDS ALONG WITH SOUTHERLY FLOW REMAINING AROUND 10 MPH TONIGHT SHOULD KEEP MINIMUM TEMPERATURES 3 TO 5 DEGREES WARMER THAN LAST NIGHT...WHICH IS RIGHT ON PAR WITH GOING FORECAST. LIGHT RETURNS ON THE KIND RADAR ARE INDICATIVE OF GRADUAL MID-LEVEL ASCENT AND SATURATION OCCURRING AHEAD OF THIS UPPER LOW. SATELLITE TRENDS AND GUIDANCE FORECASTS KEEP ALMOST ALL OF THIS ENTIRELY EAST OF THE AREA LATER TONIGHT INTO MONDAY MORNING. THE FEATURE WHICH WILL HAVE MORE INFLUENCE ON THE AREA IS A WELL- DEFINED UPPER LEVEL TROUGH ACROSS THE CANADIAN/U.S. HIGH PLAINS BORDER. IMPRESSIVE NORTH-TO-SOUTH LINE OF CONVECTION FROM NEAR INTERNATIONAL FALLS TO NORTHEAST KS HAS DEVELOPED JUST AHEAD OF THE SURFACE COOL FRONT WHERE CONVERGENCE WAS MAXIMIZED AND WITHIN A CORRIDOR OF HIGHER THETA-E RETURN. THE FRONT AND CONVECTION AHEAD OF IT WILL EVOLVE EAST INTO OVERNIGHT...LIKELY GRADUALLY TAPERING IN INTENSITY AND AT LEAST SOMEWHAT IN COVERAGE OVERNIGHT ACROSS IA AND NORTHERN MO. A PORTION OF THIS MAY MAKE IT INTO THE WESTERN FORECAST AREA IN THE EARLY MORNING...AND THE HRRR SOLUTION DEPICTS THIS...HOWEVER IT SEEMS TOO GENEROUS ON DEVELOPMENT OVERNIGHT IN THE ABSENCE OF MUCH OF A LOW-LEVEL JET/WAA. THE MID-LEVEL SHORT WAVE AXIS ACROSS EASTERN NE AND KS HELPING TO DRIVE SOME OF THE CONVECTION IS DEPICTED IN MOST GUIDANCE...AND TRACKS ACROSS THE FORECAST AREA DURING THE LATE MORNING AND AFTERNOON. COLLOCATED WITH THIS APPEARS TO BE A PRE-FRONTAL TROUGH...AT LEAST IN THE 925-700MB FLOW...WHICH HELPS IN FOCUSING SOME OF THE CONVERGENCE FIELDS. INSTABILITY VALUES ARE SIMILAR ON THE 11.00 NAM TO THOSE MENTIONED IN PRIOR DISCUSSION...SO SOME SCATTERED CONVECTION REGENERATING IN COVERAGE DURING THE MIDDAY TIME IS FAVORED AT THIS TIME. HAVE ADJUSTED MORNING POPS TO ACCOUNT FOR THIS TYPE OF TIMING/REASONING. AFTERNOON POPS STILL LOOK GOOD. MTF //PREV DISCUSSION... 317 PM CDT FOCUS OF FORECAST IS ON RAIN CHANCES MON AND MON EVE WITH A COLD FRONT MOVING ACROSS THE AREA...AND THEN ON THE VERY LOW...IF ANY...PROBABILITIES FOR RAIN THROUGH THE REST OF THE WORK WEEK AND WELL INTO NEXT WEEKEND. AN UPPER LOW OVER SOUTHERN SASKATCHEWAN AND NORTHEASTERN MT HAS CONTINUED TO BECOME SHEARED/ELONGATED TODAY...SLOWING ITS EASTWARD PROGRESS. AS A RESULT THE ASSOCIATED SURFACE LOW AND ATTENDANT COLD FRONT HAVE ALSO BEEN RELUCTANT TO MOVE EASTWARD WITH ANY VIGOR. MODELS SHOW THE UPPER LOW IS TO ACCELERATE NORTHEASTWARD LATER TODAY AND TONIGHT AS A SHORT WAVE AND JET MAX DIG SSE FROM THE YUKON-NW TERRITORIES BORDER TO SOUTHERN SASKATCHEWAN AND NE MT BY 12Z MON. THIS SHORT WAVE AND SPEED MAX ARE THEN PROGGED TO TURN SOUTHEASTERLY ACROSS THE DAKOTAS AND MN DURING THE DAY MON. WITH THE UPPER TROUGH BECOMING MORE PROGRESSIVE THE COLD FRONT...WHICH IS CURRENTLY LINGERING ACROSS NW AND W CENTRAL MN AND FAR SE SD AND NE NE... WILL ALSO START TO ACCELERATE EASTWARD...REACHING THE MID MS VALLEY BY EARLY MON AFTERNOON AND CONTINUING TO SE WI AND NE IL EARLY MON EVENING. CONVERGENCE ALONG THE COLD FRONT AS IT MOVES ACROSS THE LOCAL FORECAST AREA IS NOT VERY STRONG THOUGH TIMING OF THE FRONTAL PASSAGE DURING OR SOON AFTER PEAK HEATING LEADS TO IT OCCURRING WHEN INSTABILITY WILL BE MAXIMIZED WITH DEW POINTS SLOWLY CREEPING UP INTO THE 60S OVERNIGHT AND MON. HOWEVER...IF 10.12Z RUN OF GFS VERIFIES WITH THE LAYER FROM 2 TO 4K FT AGL SOME 3-4 DEG C WARMER THAN THE NAM SOLUTION DURING THE DAY MON THEN CONVECTIVE DEVELOPMENT AHEAD OF THE COLD FRONT WILL BE INHIBITED BY THE WARMTH ALOFT MAINTAINING A SIGNIFICANT AREA OF CIN AND CAPPING AT LEAST THROUGH 18Z MON. NAM HAS MINIMAL CIN AHEAD OF THE FRONT BUT THE QPF AND MOS POP VALUES ARE FLIPPED FROM WHAT ONE WOULD EXPECT GIVEN THE DIFFERENCES IN THE FORECAST SOUNDINGS. THAT IS...THE GFS IS MORE GENEROUS WITH THE QPF WHILE THE NAM GENERATES SOME SMALL RAINFALL AMOUNTS INTO N CENTRAL IL BOTH ONLY A FEW HUNDREDTHS AT MOST ACROSS THE REST OF THE FA...WITH MOS POPS IN LOWER END OF CHANCE CATEGORY AND GFS AT HIGH END. HAVE LOWERED POPS SLIGHTLY FOR MON THOUGH STILL LEFT AT VERY LOW END OF LIKELY WITH 55-60 PCT ACROSS THE FA. ZONAL FLOW SPREADS EASTWARD ACROSS THE ROCKIES AND GREAT PLAINS BY TUE...AND ACROSS THE MIDWEST AND GREAT LAKES BY WED BRINGING MILDER AND DRY AIR TO THE REGION. MODELS INDICATE A MINOR SHORT WAVE TO TRAVERSE THE DAKOTAS TUE NIGHT AND WED...AND THE UPPER MIDWEST WED NIGHT AND THU. THE SURFACE RIDGE THAT WILL BUILD IN BEHIND THE COLD FRONT IS PROGGED TO STILL HAVE ITS AXIS FROM QUEBEC SW BACK ACROSS THE GREAT LAKES AND TO THE MID MS VALLEY. THIS WOULD PLACE ANY THREAT OF RAIN WITH THIS DISTURBANCE TO THE N OF THE FA. UPPER RIDGING TO PUSH BACK NORTHEASTWARD ACROSS THE MIDWEST AND GREAT LAKES THU AND FRI AS AN UPPER TROUGH DEEPENS OVER FAR WESTERN NOAM. AFTER MAX TEMPS COOL TO THE 70S FOR A COUPLE DAYS AFTER THE COLD FRONTAL PASSAGE THEY CLIMB BACK INTO THE MID AND UPPER 80S FOR FRI AND NEXT WEEKEND WITH THE UPPER RIDGE BUILDING OVERHEAD. AREAS NEAR THE LAKE WILL BE COOLER FROM TUE INTO NEXT WEEKEND AS THE SURFACE HIGH BUILDING INTO THE REGION ALLOWS NNE FLOW TO TURN IN OFF OF THE LAKE TUE AND THEN WITH THE CENTER OF THE ANTICYCLONE MOVING OVER THE CENTRAL GREAT LAKES PROVIDES E TO SE LOW LEVEL FLOW OFF OF THE LAKE FROM WED ON. RIDGING SURFACE AND ALOFT TO KEEP AREA RAIN-FREE TUE THROUGH SAT...WITH ONLY SLIGHT CHANCES IN N CENTRAL IL ON SUN. WITH THE AREA NOT SEEING ANY LET ALONE SIGNIFICANT RAINFALL SINCE THE END OF MAY ANY AREAS THAT DO NOT GET ANY SIGNIFICANT RAIN WITH COLD FRONT WILL SEE MUCH GREATER MOISTURE DEFICITS AS NO ADDITIONAL THREAT OF SIGNIFICANT RAINS UNTIL AT LEAST LATE NEXT WEEKEND OR EARLY NEXT WORK WEEK. TRS && .FIRE WEATHER... 317 PM CDT WINDS AND RH VALUES APPROACHING BUT NOT EXPECTED TO REACH RED FLAG CRITERIA THE REST OF THE AFTERNOON OR EARLY THIS EVENING. TRS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 03Z... * GUSTY SOUTH WINDS DIMINISHING THIS EVENING. * SHRA/TSRA POTENTIAL MONDAY. RATZER //DISCUSSION...UPDATED 00Z... LOW PRESSURE WAS OVER SOUTHERN SASKATCHEWAN/MANITOBA AND NORTHERN MINNESOTA EARLY THIS EVENING...WITH A COLD FRONT EXTENDING SOUTH THROUGH THE OMAHA AREA AND INTO THE TEXAS PANHANDLE. SOUTH WINDS PERSISTED ACROSS MUCH OF THE MIDWEST...GUSTING ACROSS THE LOCAL FORECAST AREA INTO THE MID 20 KT RANGE. GUSTS WILL DIMINISH THROUGH SUNSET AS INVERSION DEVELOPS WITH DIURNAL COOLING...WITH SPEEDS DECREASING TO AROUND 1O KTS FOR THE OVERNIGHT HOURS. THE AFOREMENTIONED LOW WILL TRACK NORTHEAST ACROSS ONTARIO AND HUDSON BAY MONDAY...WITH THE TRAILING COLD FRONT MOVING ACROSS THE TERMINALS LATE MONDAY EVENING. GUIDANCE ARE ALL IN GOOD AGREEMENT IN DEPICTING A PRE-FRONTAL TROUGH HOWEVER...WHICH MOVES ACROSS THE FORECAST AREA DURING THE MIDDAY AND AFTERNOON HOURS. THIS TROUGH LOOKS TO HAVE THE BEST POTENTIAL TO FOCUS DEVELOPMENT OF SHRA/TSRA...ALSO COINCIDENT WITH A WEAK LEAD MID-LEVEL WAVE AND GREATEST NEAR-SURFACE BASED INSTABILITY AS DEPICTED BY VARIOUS MODELS. THE ACTUAL COLD FRONT AND MAIN UPPER LEVEL TROUGH WILL MOVE THROUGH LATE AND WILL MAINTAIN SOME THREAT OF CONVECTION THROUGH THE EVENING HOURS...THOUGH IT APPEARS DECREASING LOW LEVEL CONVERGENCE WITH WEST-SOUTHWEST LOW LEVEL WINDS BEHIND PRE- FRONTAL TROUGH WILL TEND TO LIMIT THE POTENTIAL FOR SHRA/TSRA BEYOND MID AFTERNOON. VFR CONDITIONS ARE EXPECTED TO PREVAIL EXCEPT DIRECTLY WITHIN IN SHRA/TSRA. ACTUAL COLD FRONT LOOKS TO PUSH INTO TERMINALS DURING MID TO LATE EVENING HOURS. RATZER //ORD AND MDW CONFIDENCE...UPDATED 03Z... * HIGH CONFIDENCE IN ALL ELEMENTS THROUGH THE NIGHT. * MEDIUM CONFIDENCE IN TIMING/COVERAGE OF TSRA/SHRA MONDAY. RATZER //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY THROUGH SATURDAY...VFR. RATZER && .MARINE... 202 PM...SOUTHERLY FLOW WILL CONTINUE THROUGH MONDAY AFTERNOON UNTIL A COLD FRONT MOVES ACROSS LAKE MICHIGAN MONDAY EVENING. A LARGE AREA OF LOW PRESSURE OVER SOUTHERN CANADA WILL EVENTUALLY CONSOLIDATE INTO ONE LOW AND SLOWLY LIFT NORTHEAST TO HUDSON BAY MONDAY. THE GRADIENT IS STILL EXPECTED TO TIGHTEN SOME... ESPECIALLY OVER THE NORTHERN PORTION OF THE LAKE WHERE 15-25KTS IS POSSIBLE. WINDS WILL SLOWLY DIMINISH AHEAD OF THE FRONT AND THEN SHIFT NORTHWEST BEHIND THE FRONT MONDAY EVENING INTO MONDAY NIGHT. HIGH PRESSURE BUILDS ACROSS THE PLAINS TUESDAY...MAINTAINING A NORTHWESTERLY FLOW ACROSS THE LAKE AND AS THE HIGH SPREADS EAST IN THE AFTERNOON...EXPECT THE GRADIENT TO WEAKEN ENOUGH FOR A LAKE BREEZE TO FORM ACROSS NORTHEAST IL AND NORTHWEST INDIANA. THE HIGH WILL MOVE ACROSS THE LAKES REGION TUESDAY NIGHT INTO WEDNESDAY WITH LIGHT WINDS BECOMING SOUTHERLY THURSDAY AS THE HIGH DEPARTS. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
930 PM CDT SUN JUN 10 2012 .DISCUSSION... 929 PM CDT SOME MINOR CHANGES MADE TO ARRIVAL TIMING OF POPS FOR MONDAY MORNING...OTHERWISE NO REAL CHANGES MADE TO GOING FORECAST FOR TONIGHT INTO MONDAY. EXPANSIVE UPPER LEVEL LOW AND ASSOCIATED HIGH PWAT AIR...AS SEEN ON WATER VAPOR...IS EXPANDING NORTHWARD. A WEAK UPPER LEVEL WAVE IN SOUTHWEST IL THIS EVE HAS HELPED TO SPREAD THIS NORTH CAUSING AN EXPANSION IN HIGH CLOUDS ACROSS THE AREA...WHICH SHOULD CONTINUE INTO OVERNIGHT. THESE CLOUDS ALONG WITH SOUTHERLY FLOW REMAINING AROUND 10 MPH TONIGHT SHOULD KEEP MINIMUM TEMPERATURES 3 TO 5 DEGREES WARMER THAN LAST NIGHT...WHICH IS RIGHT ON PAR WITH GOING FORECAST. LIGHT RETURNS ON THE KIND RADAR ARE INDICATIVE OF GRADUAL MID-LEVEL ASCENT AND SATURATION OCCURRING AHEAD OF THIS UPPER LOW. SATELLITE TRENDS AND GUIDANCE FORECASTS KEEP ALMOST ALL OF THIS ENTIRELY EAST OF THE AREA LATER TONIGHT INTO MONDAY MORNING. THE FEATURE WHICH WILL HAVE MORE INFLUENCE ON THE AREA IS A WELL- DEFINED UPPER LEVEL TROUGH ACROSS THE CANADIAN/U.S. HIGH PLAINS BORDER. IMPRESSIVE NORTH-TO-SOUTH LINE OF CONVECTION FROM NEAR INTERNATIONAL FALLS TO NORTHEAST KS HAS DEVELOPED JUST AHEAD OF THE SURFACE COOL FRONT WHERE CONVERGENCE WAS MAXIMIZED AND WITHIN A CORRIDOR OF HIGHER THETA-E RETURN. THE FRONT AND CONVECTION AHEAD OF IT WILL EVOLVE EAST INTO OVERNIGHT...LIKELY GRADUALLY TAPERING IN INTENSITY AND AT LEAST SOMEWHAT IN COVERAGE OVERNIGHT ACROSS IA AND NORTHERN MO. A PORTION OF THIS MAY MAKE IT INTO THE WESTERN FORECAST AREA IN THE EARLY MORNING...AND THE HRRR SOLUTION DEPICTS THIS...HOWEVER IT SEEMS TOO GENEROUS ON DEVELOPMENT OVERNIGHT IN THE ABSENCE OF MUCH OF A LOW-LEVEL JET/WAA. THE MID-LEVEL SHORT WAVE AXIS ACROSS EASTERN NE AND KS HELPING TO DRIVE SOME OF THE CONVECTION IS DEPICTED IN MOST GUIDANCE...AND TRACKS ACROSS THE FORECAST AREA DURING THE LATE MORNING AND AFTERNOON. COLLOCATED WITH THIS APPEARS TO BE A PRE-FRONTAL TROUGH...AT LEAST IN THE 925-700MB FLOW...WHICH HELPS IN FOCUSING SOME OF THE CONVERGENCE FIELDS. INSTABILITY VALUES ARE SIMILAR ON THE 11.00 NAM TO THOSE MENTIONED IN PRIOR DISCUSSION...SO SOME SCATTERED CONVECTION REGENERATING IN COVERAGE DURING THE MIDDAY TIME IS FAVORED AT THIS TIME. HAVE ADJUSTED MORNING POPS TO ACCOUNT FOR THIS TYPE OF TIMING/REASONING. AFTERNOON POPS STILL LOOK GOOD. MTF && .PREV DISCUSSION... 317 PM CDT FOCUS OF FORECAST IS ON RAIN CHANCES MON AND MON EVE WITH A COLD FRONT MOVING ACROSS THE AREA...AND THEN ON THE VERY LOW...IF ANY...PROBABILITIES FOR RAIN THROUGH THE REST OF THE WORK WEEK AND WELL INTO NEXT WEEKEND. AN UPPER LOW OVER SOUTHERN SASKATCHEWAN AND NORTHEASTERN MT HAS CONTINUED TO BECOME SHEARED/ELONGATED TODAY...SLOWING ITS EASTWARD PROGRESS. AS A RESULT THE ASSOCIATED SURFACE LOW AND ATTENDANT COLD FRONT HAVE ALSO BEEN RELUCTANT TO MOVE EASTWARD WITH ANY VIGOR. MODELS SHOW THE UPPER LOW IS TO ACCELERATE NORTHEASTWARD LATER TODAY AND TONIGHT AS A SHORT WAVE AND JET MAX DIG SSE FROM THE YUKON-NW TERRITORIES BORDER TO SOUTHERN SASKATCHEWAN AND NE MT BY 12Z MON. THIS SHORT WAVE AND SPEED MAX ARE THEN PROGGED TO TURN SOUTHEASTERLY ACROSS THE DAKOTAS AND MN DURING THE DAY MON. WITH THE UPPER TROUGH BECOMING MORE PROGRESSIVE THE COLD FRONT...WHICH IS CURRENTLY LINGERING ACROSS NW AND W CENTRAL MN AND FAR SE SD AND NE NE... WILL ALSO START TO ACCELERATE EASTWARD...REACHING THE MID MS VALLEY BY EARLY MON AFTERNOON AND CONTINUING TO SE WI AND NE IL EARLY MON EVENING. CONVERGENCE ALONG THE COLD FRONT AS IT MOVES ACROSS THE LOCAL FORECAST AREA IS NOT VERY STRONG THOUGH TIMING OF THE FRONTAL PASSAGE DURING OR SOON AFTER PEAK HEATING LEADS TO IT OCCURRING WHEN INSTABILITY WILL BE MAXIMIZED WITH DEW POINTS SLOWLY CREEPING UP INTO THE 60S OVERNIGHT AND MON. HOWEVER...IF 10.12Z RUN OF GFS VERIFIES WITH THE LAYER FROM 2 TO 4K FT AGL SOME 3-4 DEG C WARMER THAN THE NAM SOLUTION DURING THE DAY MON THEN CONVECTIVE DEVELOPMENT AHEAD OF THE COLD FRONT WILL BE INHIBITED BY THE WARMTH ALOFT MAINTAINING A SIGNIFICANT AREA OF CIN AND CAPPING AT LEAST THROUGH 18Z MON. NAM HAS MINIMAL CIN AHEAD OF THE FRONT BUT THE QPF AND MOS POP VALUES ARE FLIPPED FROM WHAT ONE WOULD EXPECT GIVEN THE DIFFERENCES IN THE FORECAST SOUNDINGS. THAT IS...THE GFS IS MORE GENEROUS WITH THE QPF WHILE THE NAM GENERATES SOME SMALL RAINFALL AMOUNTS INTO N CENTRAL IL BOTH ONLY A FEW HUNDREDTHS AT MOST ACROSS THE REST OF THE FA...WITH MOS POPS IN LOWER END OF CHANCE CATEGORY AND GFS AT HIGH END. HAVE LOWERED POPS SLIGHTLY FOR MON THOUGH STILL LEFT AT VERY LOW END OF LIKELY WITH 55-60 PCT ACROSS THE FA. ZONAL FLOW SPREADS EASTWARD ACROSS THE ROCKIES AND GREAT PLAINS BY TUE...AND ACROSS THE MIDWEST AND GREAT LAKES BY WED BRINGING MILDER AND DRY AIR TO THE REGION. MODELS INDICATE A MINOR SHORT WAVE TO TRAVERSE THE DAKOTAS TUE NIGHT AND WED...AND THE UPPER MIDWEST WED NIGHT AND THU. THE SURFACE RIDGE THAT WILL BUILD IN BEHIND THE COLD FRONT IS PROGGED TO STILL HAVE ITS AXIS FROM QUEBEC SW BACK ACROSS THE GREAT LAKES AND TO THE MID MS VALLEY. THIS WOULD PLACE ANY THREAT OF RAIN WITH THIS DISTURBANCE TO THE N OF THE FA. UPPER RIDGING TO PUSH BACK NORTHEASTWARD ACROSS THE MIDWEST AND GREAT LAKES THU AND FRI AS AN UPPER TROUGH DEEPENS OVER FAR WESTERN NOAM. AFTER MAX TEMPS COOL TO THE 70S FOR A COUPLE DAYS AFTER THE COLD FRONTAL PASSAGE THEY CLIMB BACK INTO THE MID AND UPPER 80S FOR FRI AND NEXT WEEKEND WITH THE UPPER RIDGE BUILDING OVERHEAD. AREAS NEAR THE LAKE WILL BE COOLER FROM TUE INTO NEXT WEEKEND AS THE SURFACE HIGH BUILDING INTO THE REGION ALLOWS NNE FLOW TO TURN IN OFF OF THE LAKE TUE AND THEN WITH THE CENTER OF THE ANTICYCLONE MOVING OVER THE CENTRAL GREAT LAKES PROVIDES E TO SE LOW LEVEL FLOW OFF OF THE LAKE FROM WED ON. RIDGING SURFACE AND ALOFT TO KEEP AREA RAIN-FREE TUE THROUGH SAT...WITH ONLY SLIGHT CHANCES IN N CENTRAL IL ON SUN. WITH THE AREA NOT SEEING ANY LET ALONE SIGNIFICANT RAINFALL SINCE THE END OF MAY ANY AREAS THAT DO NOT GET ANY SIGNIFICANT RAIN WITH COLD FRONT WILL SEE MUCH GREATER MOISTURE DEFICITS AS NO ADDITIONAL THREAT OF SIGNIFICANT RAINS UNTIL AT LEAST LATE NEXT WEEKEND OR EARLY NEXT WORK WEEK. TRS && .FIRE WEATHER... 317 PM CDT WINDS AND RH VALUES APPROACHING BUT NOT EXPECTED TO REACH RED FLAG CRITERIA THE REST OF THE AFTERNOON OR EARLY THIS EVENING. TRS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 00Z... * GUSTY SOUTH WINDS DIMINISHING THIS EVENING. * SHRA/TSRA POTENTIAL MONDAY. RATZER //DISCUSSION...UPDATED 00Z... LOW PRESSURE WAS OVER SOUTHERN SASKATCHEWAN/MANITOBA AND NORTHERN MINNESOTA EARLY THIS EVENING...WITH A COLD FRONT EXTENDING SOUTH THROUGH THE OMAHA AREA AND INTO THE TEXAS PANHANDLE. SOUTH WINDS PERSISTED ACROSS MUCH OF THE MIDWEST...GUSTING ACROSS THE LOCAL FORECAST AREA INTO THE MID 20 KT RANGE. GUSTS WILL DIMINISH THROUGH SUNSET AS INVERSION DEVELOPS WITH DIURNAL COOLING...WITH SPEEDS DECREASING TO AROUND 1O KTS FOR THE OVERNIGHT HOURS. THE AFOREMENTIONED LOW WILL TRACK NORTHEAST ACROSS ONTARIO AND HUDSON BAY MONDAY...WITH THE TRAILING COLD FRONT MOVING ACROSS THE TERMINALS LATE MONDAY EVENING. GUIDANCE ARE ALL IN GOOD AGREEMENT IN DEPICTING A PRE-FRONTAL TROUGH HOWEVER...WHICH MOVES ACROSS THE FORECAST AREA DURING THE MIDDAY AND AFTERNOON HOURS. THIS TROUGH LOOKS TO HAVE THE BEST POTENTIAL TO FOCUS DEVELOPMENT OF SHRA/TSRA...ALSO COINCIDENT WITH A WEAK LEAD MID-LEVEL WAVE AND GREATEST NEAR-SURFACE BASED INSTABILITY AS DEPICTED BY VARIOUS MODELS. THE ACTUAL COLD FRONT AND MAIN UPPER LEVEL TROUGH WILL MOVE THROUGH LATE AND WILL MAINTAIN SOME THREAT OF CONVECTION THROUGH THE EVENING HOURS...THOUGH IT APPEARS DECREASING LOW LEVEL CONVERGENCE WITH WEST-SOUTHWEST LOW LEVEL WINDS BEHIND PRE- FRONTAL TROUGH WILL TEND TO LIMIT THE POTENTIAL FOR SHRA/TSRA BEYOND MID AFTERNOON. VFR CONDITIONS ARE EXPECTED TO PREVAIL EXCEPT DIRECTLY WITHIN IN SHRA/TSRA. ACTUAL COLD FRONT LOOKS TO PUSH INTO TERMINALS DURING MID TO LATE EVENING HOURS. RATZER //ORD AND MDW CONFIDENCE...UPDATED 00Z... * HIGH CONFIDENCE IN ALL ELEMENTS THROUGH THE NIGHT. * MEDIUM CONFIDENCE IN TIMING/COVERAGE OF TSRA/SHRA MONDAY. RATZER //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY THROUGH SATURDAY...VFR. RATZER && .MARINE... 202 PM...SOUTHERLY FLOW WILL CONTINUE THROUGH MONDAY AFTERNOON UNTIL A COLD FRONT MOVES ACROSS LAKE MICHIGAN MONDAY EVENING. A LARGE AREA OF LOW PRESSURE OVER SOUTHERN CANADA WILL EVENTUALLY CONSOLIDATE INTO ONE LOW AND SLOWLY LIFT NORTHEAST TO HUDSON BAY MONDAY. THE GRADIENT IS STILL EXPECTED TO TIGHTEN SOME... ESPECIALLY OVER THE NORTHERN PORTION OF THE LAKE WHERE 15-25KTS IS POSSIBLE. WINDS WILL SLOWLY DIMINISH AHEAD OF THE FRONT AND THEN SHIFT NORTHWEST BEHIND THE FRONT MONDAY EVENING INTO MONDAY NIGHT. HIGH PRESSURE BUILDS ACROSS THE PLAINS TUESDAY...MAINTAINING A NORTHWESTERLY FLOW ACROSS THE LAKE AND AS THE HIGH SPREADS EAST IN THE AFTERNOON...EXPECT THE GRADIENT TO WEAKEN ENOUGH FOR A LAKE BREEZE TO FORM ACROSS NORTHEAST IL AND NORTHWEST INDIANA. THE HIGH WILL MOVE ACROSS THE LAKES REGION TUESDAY NIGHT INTO WEDNESDAY WITH LIGHT WINDS BECOMING SOUTHERLY THURSDAY AS THE HIGH DEPARTS. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
858 PM CDT SUN JUN 10 2012 .DISCUSSION... ISSUED 852 PM CDT SUN JUN 10 2012 LATEST SURFACE ANALYSIS INDICATES THE COLD FRONT WHICH WILL AFFECT OUR AREA ON MONDAY WAS LOCATED OVER EXTREME WESTERN IOWA EARLY THIS EVENING. CONVECTION HAS BEEN ORGANIZING ALONG AND JUST TO THE EAST OF THE FRONT OVER THE PAST SEVERAL HOURS AND SEEMS TO BE GETTING BETTER ORGANIZED...ESPECIALLY ACRS SOUTHWEST IOWA INTO SE NEBRASKA WHERE THE CONVERGENCE WAS MOST PRONOUNCED OVER THE PAST SEVERAL HOURS. SHORT TERM MODELS CONTINUE TO SUGGEST THE CONVECTION WILL PUSH EAST AND SOUTHEAST THRU IOWA AND INTO NORTHERN MISSOURI LATE THIS EVENING AND INTO THE EARLY MORNING HOURS WITH A GRADUAL WEAKENING TREND AS IT TRACKS TO EXTREME EASTERN IOWA AND NE MISSOURI TOWARDS 300 AM...AND POSSIBLY INTO PARTS OF WEST CENTRAL IL JUST BEFORE DAWN. THE 00Z ILX AND SGF SOUNDINGS SHOWING A FAIRLY STRONG CAP IN PLACE EARLY THIS EVENING WITH OUR AREAS IN BETWEEN THE BETTER MOISTURE SOURCES...WITH THE DEEP TROPICAL MOISTURE ASSOCIATED WITH THE SOUTHERN MISSISSIPPI VALLEY UPPER WAVE MAINLY ACRS THE EAST AND SE SECTIONS OF OUR FORECAST AREA...AND THE BETTER LOW LEVEL MOISTURE AHEAD OF THE FRONT LOCATED IN A NARROW SW-NE CORRIDOR JUST AHEAD OF THE COLD FRONT. THE BETTER INSTABILITY FROM THE SPC MESOANALYSIS WAS LOCATED ACROSS PARTS OF SOUTHWEST IOWA INTO EASTERN KS AND NW MO WHERE SURFACE BASE CAPES WERE IN THE 2500 TO 3000 J/JG OVER THE PAST HOUR WITH THE ELEVATED MIXED LAYER STARTING TO ERODE THANKS TO THE INCREASING SFC MOISTURE CONVERGENCE AND JET DYNAMICS. PROPAGATION VECTORS SUGGEST THE MORE ORGANIZED CONVECTION MAY START TO TURN SE INTO PARTS OF NW MO AND NE KS EARLY THIS EVENING AS THE NORTHERN PORTION OF THE CONVECTION WEAKENS SOME AS IT TRACKS FURTHER EAST. THIS TYPE OF SCENARIO DOES NOT BODE WELL WITH RESPECT TO SEEING SOME DECENT RAINFALL ACRS OUR AREA ON MONDAY. WHAT IS LEFT OF THE CONVECTION WILL PUSH ACRS WESTERN IL DURING THE MORNING AND POSSIBLY REDEVELOP ALONG OR EAST OF THE I-55 CORRIDOR DURING THE AFTERNOON AS THE COLD FRONT APPROACHES THE AREA. UPPER LEVEL SUPPORT AS WELL AS ANY LOW LEVEL CONVERGENCE DOES NOT LOOK THAT GREAT FOR ANY SIGNIFICANT ORGANIZATION TO THE CONVECTION TOMORROW AHEAD OF THE COLD FRONT...DESPITE THE MODERATE INSTABILITY SEEN ON MODELS...NEVER THE LESS...WE SHOULD SEE AT LEAST SOME SCATTERED SHOWERS AND THUNDERSTORMS ACRS THE AREA DURING THE DAY BUT THIS CERTAINLY DOESN`T LOOK LIKE IT WILL PRODUCE WIDESPREAD RAINFALL...WHICH WE DESPERATELY NEED. THE CURRENT ZONE FORECAST IS IN GOOD SHAPE THIS EVENING...SO OTHER THAN THE USUAL EARLY EVENING TWEAKS TO THE HOURLY TEMPERATURE GRIDS...NO OTHER ADJUSTMENTS WILL BE NEEDED...AS A RESULT NO ZONE UPDATE WILL BE NEEDED. SMITH && .AVIATION... ISSUED 605 PM CDT SUN JUN 10 2012 VFR CONDITIONS WILL CONTINUE THRU MOST OF THE NIGHT WITH THE MAIN CONCERN BEING THE CONVECTION OCCURRING OVER PARTS OF WESTERN IOWA ALONG A COLD FRONT. MOST MODELS MOVE THIS CONVECTION TO JUST WEST OF THE MISSISSIPPI RIVER BY 09Z IN A WEAKENING STATE. SOME OF THE SHOWERS MAY MAKE IT TO PIA AND SPI BY 12Z BUT THE AIRMASS THIS FAR EAST IS NOT VERY SUPPORTIVE OF THE LINE HOLDING MUCH PAST EAST CENTRAL IOWA...SO FOR NOW WILL CONTINUE WITH THE TIMING OF THE SHOWERS IN THE TAFS. FORECAST SOUNDINGS INDICATE THAT AT LEAST SOME SCATTERED CLOUDS AT AROUND 2000 FEET WILL DEVELOP AHEAD OF THE FRONT AFTR 09Z BUT THAT IS A LOW PROBABILITY OCCURRENCE AT THIS TIME SO WILL HOLD OFF INCLUDING ANY MVFR CIGS MONDAY MORNING. WITH RESPECT TO THE IOWA STORMS LATE TONIGHT/MON MORNING...WILL HOLD ON TO THE VCTS AND A CB GROUP FOR THE MID MORNING HOURS AND BEYOND AS THE COLD FRONT SHIFTS ACRS THE FORECAST AREA MONDAY AFTN WITH A CONTINUING THREAT FOR WDLY SCATTERED CONVECTION. THE THREAT FOR RAIN SHOULD END BY 02Z AT CMI AS THE FRONT SHIFTS OFF TO OUR EAST. SFC WINDS TONIGHT WILL BE OUT OF THE SE AT 10 KTS OR LESS...AND THEN WINDS ARE EXPECTED TO START TO VEER MORE INTO THE SOUTHWEST MONDAY MORNING AHEAD OF THE COLD FRONT...WITH SPEEDS OF 10 TO 15 KTS. SMITH && .PREV DISCUSSION... ISSUED 257 PM CDT SUN JUN 10 2012 SHORT TERM...TONIGHT THROUGH WEDNESDAY UPPER-LEVEL DISTURBANCE CURRENTLY OVER THE LOWER MISSISSIPPI RIVER VALLEY WILL CONTINUE TO SPREAD MOISTURE NORTHWARD INTO THE REGION TONIGHT. LATEST SATELLITE/RADAR LOOPS INDICATE THE DEEPER MOISTURE AND ASSOCIATED PRECIP ARE PRIMARILY LIMITED TO LOCATIONS ALONG AND TO THE RIGHT OF THIS FEATURE. AS A RESULT...THE BEST RAIN CHANCES WILL SPREAD INTO THE TENNESSEE AND OHIO RIVER VALLEYS TONIGHT...GENERALLY STAYING EAST OF ILLINOIS. HIGH-RES MODELS SUCH AS THE HRRR ARE KEEPING THE KILX CWA DRY...HOWEVER WITH DEEPER MOISTURE COMING SO CLOSE TO THE E/SE...HAVE OPTED TO MAINTAIN A SLIM CHANCE FOR SHOWERS ALONG/EAST OF I-57 TONIGHT. MEANWHILE...VIGOROUS UPPER WAVE OVER THE NORTHERN ROCKIES WILL TRACK ALONG THE CANADIAN BORDER TOWARD THE NORTHERN GREAT LAKES BY MONDAY EVENING. TRAILING COLD FRONT WILL CROSS THE MISSISSIPPI RIVER BY AROUND MIDDAY MONDAY AND BE LOCATED ALONG THE I-55 CORRIDOR BY EARLY MONDAY EVENING. AIRMASS AHEAD OF THE FRONT WILL BECOME MODERATELY UNSTABLE...CHARACTERIZED BY CAPE VALUES OF 1500 TO 2500J/KG. MITIGATING FACTOR FOR WIDESPREAD THUNDERSTORMS AND SEVERE POTENTIAL WILL BE LACK OF WIND SHEAR. FORECAST SOUNDINGS INDICATE WEAK WIND PROFILE THROUGHOUT THE ENTIRE DEPTH OF THE ATMOSPHERE AND VERY WEAK 0-6 KM BULK SHEAR VALUES OF 15 TO 25KT. DESPITE LACK OF SHEAR...ADEQUATE INSTABILITY AND GOOD CONVERGENCE ALONG THE ADVANCING FRONT WILL RESULT IN A BROKEN LINE OF STORMS...WITH A LOW PROBABILITY FOR SEVERE. PRIMARY TIME FRAME WILL BE DURING THE LATE MORNING/AFTERNOON WEST OF I-55...AND DURING THE EVENING FURTHER EAST. ANY CONVECTION WILL QUICKLY EXIT INTO INDIANA AFTER MIDNIGHT...WITH CLEARING SKIES NOTED FROM WEST TO EAST ACROSS THE AREA TOWARD DAWN. HIGH PRESSURE WILL BUILD INTO THE GREAT LAKES BEHIND THE DEPARTING COLD FRONT ON TUESDAY AND WEDNESDAY...BRINGING A COOLER/DRIER AIRMASS INTO THE REGION. WITH 850MB TEMPS PROGGED TO DROP INTO THE 12 TO 14C RANGE...HIGHS WILL FALL BACK TO NEAR NORMAL FOR THIS TIME OF YEAR IN THE UPPER 70S/LOWER 80S. LONG TERM...THURSDAY THROUGH SUNDAY MODELS CONTINUE TO ADVERTISE UPPER TROUGHING DEVELOPING ACROSS THE WESTERN CONUS BY THE END OF THE WEEK...RESULTING IN DOWNSTREAM RIDGING AND WARMER WEATHER FOR THE MIDWEST. EXACT EVOLUTION AND DEGREE OF AMPLIFICATION STILL REMAIN IN QUESTION...WITH A SLIGHTLY DIFFERENT SOLUTION FEATURED ON EACH SUCCESSIVE MODEL RUN. GIVEN UNCERTAINTIES...HAVE OPTED TO MAINTAIN A DRY FORECAST THROUGH NEXT WEEKEND EVEN THOUGH THE ECMWF SUGGESTS A FRONT MAY APPROACH FROM THE NORTHWEST BY SUNDAY. 12Z 10 JUN GFS IS MUCH STRONGER WITH THE EASTERN RIDGE AND DEVELOPS A REX BLOCK ACROSS THE GREAT LAKES/OHIO RIVER VALLEY. IF THIS SOLUTION PANS OUT...THE NEXT CHANCE FOR RAIN WOULD BE DELAYED PERHAPS UNTIL THE MIDDLE OF NEXT WEEK. WILL THEREFORE MAINTAIN WARM/DRY CONDITIONS THROUGH SUNDAY...UNTIL BETTER MODEL CONSISTENCY IS ACHIEVED. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
615 PM CDT SUN JUN 10 2012 .DISCUSSION... ISSUED 257 PM CDT SUN JUN 10 2012 SHORT TERM...TONIGHT THROUGH WEDNESDAY UPPER-LEVEL DISTURBANCE CURRENTLY OVER THE LOWER MISSISSIPPI RIVER VALLEY WILL CONTINUE TO SPREAD MOISTURE NORTHWARD INTO THE REGION TONIGHT. LATEST SATELLITE/RADAR LOOPS INDICATE THE DEEPER MOISTURE AND ASSOCIATED PRECIP ARE PRIMARILY LIMITED TO LOCATIONS ALONG AND TO THE RIGHT OF THIS FEATURE. AS A RESULT...THE BEST RAIN CHANCES WILL SPREAD INTO THE TENNESSEE AND OHIO RIVER VALLEYS TONIGHT...GENERALLY STAYING EAST OF ILLINOIS. HIGH-RES MODELS SUCH AS THE HRRR ARE KEEPING THE KILX CWA DRY...HOWEVER WITH DEEPER MOISTURE COMING SO CLOSE TO THE E/SE...HAVE OPTED TO MAINTAIN A SLIM CHANCE FOR SHOWERS ALONG/EAST OF I-57 TONIGHT. MEANWHILE...VIGOROUS UPPER WAVE OVER THE NORTHERN ROCKIES WILL TRACK ALONG THE CANADIAN BORDER TOWARD THE NORTHERN GREAT LAKES BY MONDAY EVENING. TRAILING COLD FRONT WILL CROSS THE MISSISSIPPI RIVER BY AROUND MIDDAY MONDAY AND BE LOCATED ALONG THE I-55 CORRIDOR BY EARLY MONDAY EVENING. AIRMASS AHEAD OF THE FRONT WILL BECOME MODERATELY UNSTABLE...CHARACTERIZED BY CAPE VALUES OF 1500 TO 2500J/KG. MITIGATING FACTOR FOR WIDESPREAD THUNDERSTORMS AND SEVERE POTENTIAL WILL BE LACK OF WIND SHEAR. FORECAST SOUNDINGS INDICATE WEAK WIND PROFILE THROUGHOUT THE ENTIRE DEPTH OF THE ATMOSPHERE AND VERY WEAK 0-6 KM BULK SHEAR VALUES OF 15 TO 25KT. DESPITE LACK OF SHEAR...ADEQUATE INSTABILITY AND GOOD CONVERGENCE ALONG THE ADVANCING FRONT WILL RESULT IN A BROKEN LINE OF STORMS...WITH A LOW PROBABILITY FOR SEVERE. PRIMARY TIME FRAME WILL BE DURING THE LATE MORNING/AFTERNOON WEST OF I-55...AND DURING THE EVENING FURTHER EAST. ANY CONVECTION WILL QUICKLY EXIT INTO INDIANA AFTER MIDNIGHT...WITH CLEARING SKIES NOTED FROM WEST TO EAST ACROSS THE AREA TOWARD DAWN. HIGH PRESSURE WILL BUILD INTO THE GREAT LAKES BEHIND THE DEPARTING COLD FRONT ON TUESDAY AND WEDNESDAY...BRINGING A COOLER/DRIER AIRMASS INTO THE REGION. WITH 850MB TEMPS PROGGED TO DROP INTO THE 12 TO 14C RANGE...HIGHS WILL FALL BACK TO NEAR NORMAL FOR THIS TIME OF YEAR IN THE UPPER 70S/LOWER 80S. LONG TERM...THURSDAY THROUGH SUNDAY MODELS CONTINUE TO ADVERTISE UPPER TROUGHING DEVELOPING ACROSS THE WESTERN CONUS BY THE END OF THE WEEK...RESULTING IN DOWNSTREAM RIDGING AND WARMER WEATHER FOR THE MIDWEST. EXACT EVOLUTION AND DEGREE OF AMPLIFICATION STILL REMAIN IN QUESTION...WITH A SLIGHTLY DIFFERENT SOLUTION FEATURED ON EACH SUCCESSIVE MODEL RUN. GIVEN UNCERTAINTIES...HAVE OPTED TO MAINTAIN A DRY FORECAST THROUGH NEXT WEEKEND EVEN THOUGH THE ECMWF SUGGESTS A FRONT MAY APPROACH FROM THE NORTHWEST BY SUNDAY. 12Z 10 JUN GFS IS MUCH STRONGER WITH THE EASTERN RIDGE AND DEVELOPS A REX BLOCK ACROSS THE GREAT LAKES/OHIO RIVER VALLEY. IF THIS SOLUTION PANS OUT...THE NEXT CHANCE FOR RAIN WOULD BE DELAYED PERHAPS UNTIL THE MIDDLE OF NEXT WEEK. WILL THEREFORE MAINTAIN WARM/DRY CONDITIONS THROUGH SUNDAY...UNTIL BETTER MODEL CONSISTENCY IS ACHIEVED. && .AVIATION... ISSUED 605 PM CDT SUN JUN 10 2012 VFR CONDITIONS WILL CONTINUE THRU MOST OF THE NIGHT WITH THE MAIN CONCERN BEING THE CONVECTION OCCURRING OVER PARTS OF WESTERN IOWA ALONG A COLD FRONT. MOST MODELS MOVE THIS CONVECTION TO JUST WEST OF THE MISSISSIPPI RIVER BY 09Z IN A WEAKENING STATE. SOME OF THE SHOWERS MAY MAKE IT TO PIA AND SPI BY 12Z BUT THE AIRMASS THIS FAR EAST IS NOT VERY SUPPORTIVE OF THE LINE HOLDING MUCH PAST EAST CENTRAL IOWA...SO FOR NOW WILL CONTINUE WITH THE TIMING OF THE SHOWERS IN THE TAFS. FORECAST SOUNDINGS INDICATE THAT AT LEAST SOME SCATTERED CLOUDS AT AROUND 2000 FEET WILL DEVELOP AHEAD OF THE FRONT AFTR 09Z BUT THAT IS A LOW PROBABILITY OCCURRENCE AT THIS TIME SO WILL HOLD OFF INCLUDING ANY MVFR CIGS MONDAY MORNING. WITH RESPECT TO THE IOWA STORMS LATE TONIGHT/MON MORNING...WILL HOLD ON TO THE VCTS AND A CB GROUP FOR THE MID MORNING HOURS AND BEYOND AS THE COLD FRONT SHIFTS ACRS THE FORECAST AREA MONDAY AFTN WITH A CONTINUING THREAT FOR WDLY SCATTERED CONVECTION. THE THREAT FOR RAIN SHOULD END BY 02Z AT CMI AS THE FRONT SHIFTS OFF TO OUR EAST. SFC WINDS TONIGHT WILL BE OUT OF THE SE AT 10 KTS OR LESS...AND THEN WINDS ARE EXPECTED TO START TO VEER MORE INTO THE SOUTHWEST MONDAY MORNING AHEAD OF THE COLD FRONT...WITH SPEEDS OF 10 TO 15 KTS. SMITH && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1017 PM EDT SUN JUN 10 2012 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 308 PM EDT SUN JUN 10 2012 AN UPPER SYSTEM WILL MOVE SOUTHEAST OF THE AREA ON MONDAY BRINGING SOME RAIN TO THE AREA...THEN A COLD FRONT WILL MOVE THROUGH ON MONDAY NIGHT BRINGING ADDITIONAL CHANCES FOR RAIN. HIGH PRESSURE WILL THEN BUILD IN AND DRY WEATHER INTO NEXT WEEKEND. && .NEAR TERM /OVERNIGHT/... ISSUED AT 940 PM EDT SUN JUN 10 2012 MID AND HIGH LEVEL CLOUDS ASSOCIATED WITH THE UPPER LEVEL DISTURBANCE OVER THE TENNESSEE VALLEY CONTINUING TO SPREAD INTO THE REGION THIS EVENING. HAVE SEEN A FEW SPRINKLES/VERY LIGHT RAIN SHOWERS MOVING NORTH THROUGH SOUTHERN FORECAST AREA. TEMPS WERE IN THE UPPER 70S AND LOWER 80S AT 01Z. NOT MUCH CHANGE TO CURRENT FORECAST FOR THE OVERNIGHT. ONLY EXCEPTION WILL BE TO MAKE SOME REFINEMENTS TO POPS BASED ON RADAR AND SATELLITE TRENDS AND SUPPORTED BY MOST RECENT SHORT RANGE MODEL GUIDANCE. GREATER COVERAGE TO RAINFALL ASSOCIATED WITH THE UPPER DISTURBANCE FROM MIDDLE TENNESSEE SOUTH INTO ALABAMA/GEORGIA CURRENTLY. RAP APPEARS TO CAPTURE THIS ACTIVITY WELL THIS EVENING...TRACKING IT N/NE OVERNIGHT AND INTO THE OHIO VALLEY TOWARDS DAYBREAK. WILL CONTINUE WITH LIKELY POPS OVER FAR SOUTHEAST COUNTIES WHERE CONFIDENCE IS HIGHEST IN MEASURABLE PRECIP LATE. DROPPED BACK TO LOW CHANCE POPS FURTHER NORTH AND WEST OVER MUCH OF THE REMAINDER OF THE FORECAST AREA. ALSO REMOVED ISOLATED THUNDER FROM ALL BUT FAR SOUTHEAST COUNTIES WITH ONLY WEAK ELEVATED CAPE VALUES PRESENT AND LITTLE IN THE WAY OF LIGHTNING STRIKES WITH PRECIP SHIELD TO OUR SOUTH. ZONE AND GRID UPDATES OUT SHORTLY. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... ISSUED AT 308 PM EDT SUN JUN 10 2012 FOCUS IS ON RAIN CHANCES EARLY IN THE PERIOD. NAM IS A LITTLE STRONGER THAN THE OTHER MODELS AND STANDS OUT...SO WENT CLOSER TO GFS/ECMWF. UPPER SYSTEM TO OUR EAST WILL STILL BE CLOSE ENOUGH FOR LOW END LIKELY POPS MONDAY MORNING ACROSS THE EAST AND CHANCE POPS ELSEWHERE. THEN FOR THE AFTERNOON THE FORECAST AREA WILL BE IN BETWEEN THE EASTERN SYSTEM AND A COLD FRONT APPROACHING FROM THE WEST. THUS WENT CHANCE POPS ALL AREAS DURING THE AFTERNOON. THE FRONT WILL MOVE IN MONDAY NIGHT...BUT BY THEN TIMING IS NOT FAVORABLE AS INSTABILITY WILL BE DIMINISHING. THUS AGAIN ONLY WENT CHANCE POPS DURING THE EVENING...DECREASING OVERNIGHT. ONLY KEPT SLIGHT CHANCE POPS IN THE FAR EAST ON TUESDAY TO ACCOUNT FOR ANY LINGERING SHOWERS BEHIND THE FRONT...BUT THIS WILL PROBABLY BE ABLE TO BE REMOVED IF CURRENT MODEL TRENDS CONTINUE. DRY CONDITIONS WILL THEN MOVE IN THROUGH WEDNESDAY AS HIGH PRESSURE MOVES IN. AS FAR AS TEMPERATURES ARE CONCERNED...WENT CLOSER TO THE WARMER MAV ON MONDAY AS NOTED ABOVE MOST OF THE AREA WILL BE IN BETWEEN SYSTEMS DURING THE DAY. STUCK CLOSE TO MODEL BLEND FOR MUCH OF THE REST OF THE PERIOD. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... ISSUED AT 308 PM EDT SUN JUN 10 2012 HIGH PRESSURE OVER THE GREAT LAKES WILL SLOWLY MAKES ITS WAY TOWARDS NEW ENGLAND KEEPING CONDITIONS DRY THROUGHOUT THE PERIOD. THE GFS AND CANADIAN DEPICT A WEAK WAVE AND ASSOCIATED VORT MAX POSSIBLY IMPACTING THE AREA ON SUNDAY. HOWEVER...MODELS CURRENTLY INDICATE PRECIPITATION CHANCES NOT EXPECTED TO IMPACT THE AREA UNTIL SUNDAY NIGHT AT THE EARLIEST. THEREFORE...REMOVED ALLBLEND SLIGHT CHANCE POPS AND CONTINUED WITH AN ENTIRELY DRY FORECAST FOR THE LONG TERM. TEMPERATURES WILL START OUT NEAR NORMAL VALUES AND GRADUALLY INCREASE THROUGHOUT THE PERIOD ALLOWING ABOVE NORMAL VALUES TO RETURN. && .AVIATION /DISCUSSION FOR THE 110300Z KIND TAF UPDATE/... ISSUED AT 1017 PM EDT SUN JUN 10 2012 NO SIGNIFICANT CHANGES MADE TO THE FORECAST AT THIS TIME. PREVIOUS DISCUSSION FOLLOWS. MID LEVEL DISTURBANCE CURRENTLY LOCATED OVER THE LOWER MISSISSIPPI VALLEY EXPECTED TO DRIFT TO THE NORTHEAST TONIGHT...AND BEGIN MOVING INTO THE LOCAL AREA AROUND SUNRISE MONDAY BASED ON SHORT TERM MODEL DATA. CEILINGS SHOULD GRADUALLY LOWER TONIGHT AS MOISTURE ADVECTS IN...PROBABLY FALLING BELOW 050 SOMETIME AFTER 110600Z. SCATTERED SHOWER ACTIVITY EXPECTED TO DEVELOP AFTER ABOUT 110900Z AS DISTURBANCE APPROACHES. LIFT APPEARS RATHER DISORGANIZED AND MAIN RIBBON OF 850MB FLOW LOOKS TO SET UP EAST OF THE TAF SITES...SO DON/T THINK ANY RAINFALL LATE TONIGHT WILL BE HEAVY ENOUGH TO RESULT IN IFR VISIBILITY RESTRICTIONS. MARGINAL ELEVATED INSTABILITY PROGGED TO MOVE INTO THE AREA LATE TONIGHT...BUT WITHOUT ANY SIGNIFICANT FORCING...THREAT OF ANY LIGHTNING ACTIVITY NEAR THE TAF SITES LOOKS RATHER LOW. LINGERING SURFACE WIND GUSTS EXPECTED TO DIMINISH OVER THE NEXT COUPLE OF HOURS AS MIXING ENDS WITH SUNSET. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...50 NEAR TERM...RYAN SHORT TERM...50 LONG TERM....HOMANN/50 AVIATION...JAS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
940 PM EDT SUN JUN 10 2012 .UPDATE... THE NEAR TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 308 PM EDT SUN JUN 10 2012 AN UPPER SYSTEM WILL MOVE SOUTHEAST OF THE AREA ON MONDAY BRINGING SOME RAIN TO THE AREA...THEN A COLD FRONT WILL MOVE THROUGH ON MONDAY NIGHT BRINGING ADDITIONAL CHANCES FOR RAIN. HIGH PRESSURE WILL THEN BUILD IN AND DRY WEATHER INTO NEXT WEEKEND. && .NEAR TERM /OVERNIGHT/... ISSUED AT 940 PM EDT SUN JUN 10 2012 MID AND HIGH LEVEL CLOUDS ASSOCIATED WITH THE UPPER LEVEL DISTURBANCE OVER THE TENNESSEE VALLEY CONTINUING TO SPREAD INTO THE REGION THIS EVENING. HAVE SEEN A FEW SPRINKLES/VERY LIGHT RAIN SHOWERS MOVING NORTH THROUGH SOUTHERN FORECAST AREA. TEMPS WERE IN THE UPPER 70S AND LOWER 80S AT 01Z. NOT MUCH CHANGE TO CURRENT FORECAST FOR THE OVERNIGHT. ONLY EXCEPTION WILL BE TO MAKE SOME REFINEMENTS TO POPS BASED ON RADAR AND SATELLITE TRENDS AND SUPPORTED BY MOST RECENT SHORT RANGE MODEL GUIDANCE. GREATER COVERAGE TO RAINFALL ASSOCIATED WITH THE UPPER DISTURBANCE FROM MIDDLE TENNESSEE SOUTH INTO ALABAMA/GEORGIA CURRENTLY. RAP APPEARS TO CAPTURE THIS ACTIVITY WELL THIS EVENING...TRACKING IT N/NE OVERNIGHT AND INTO THE OHIO VALLEY TOWARDS DAYBREAK. WILL CONTINUE WITH LIKELY POPS OVER FAR SOUTHEAST COUNTIES WHERE CONFIDENCE IS HIGHEST IN MEASURABLE PRECIP LATE. DROPPED BACK TO LOW CHANCE POPS FURTHER NORTH AND WEST OVER MUCH OF THE REMAINDER OF THE FORECAST AREA. ALSO REMOVED ISOLATED THUNDER FROM ALL BUT FAR SOUTHEAST COUNTIES WITH ONLY WEAK ELEVATED CAPE VALUES PRESENT AND LITTLE IN THE WAY OF LIGHTNING STRIKES WITH PRECIP SHIELD TO OUR SOUTH. ZONE AND GRID UPDATES OUT SHORTLY. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... ISSUED AT 308 PM EDT SUN JUN 10 2012 FOCUS IS ON RAIN CHANCES EARLY IN THE PERIOD. NAM IS A LITTLE STRONGER THAN THE OTHER MODELS AND STANDS OUT...SO WENT CLOSER TO GFS/ECMWF. UPPER SYSTEM TO OUR EAST WILL STILL BE CLOSE ENOUGH FOR LOW END LIKELY POPS MONDAY MORNING ACROSS THE EAST AND CHANCE POPS ELSEWHERE. THEN FOR THE AFTERNOON THE FORECAST AREA WILL BE IN BETWEEN THE EASTERN SYSTEM AND A COLD FRONT APPROACHING FROM THE WEST. THUS WENT CHANCE POPS ALL AREAS DURING THE AFTERNOON. THE FRONT WILL MOVE IN MONDAY NIGHT...BUT BY THEN TIMING IS NOT FAVORABLE AS INSTABILITY WILL BE DIMINISHING. THUS AGAIN ONLY WENT CHANCE POPS DURING THE EVENING...DECREASING OVERNIGHT. ONLY KEPT SLIGHT CHANCE POPS IN THE FAR EAST ON TUESDAY TO ACCOUNT FOR ANY LINGERING SHOWERS BEHIND THE FRONT...BUT THIS WILL PROBABLY BE ABLE TO BE REMOVED IF CURRENT MODEL TRENDS CONTINUE. DRY CONDITIONS WILL THEN MOVE IN THROUGH WEDNESDAY AS HIGH PRESSURE MOVES IN. AS FAR AS TEMPERATURES ARE CONCERNED...WENT CLOSER TO THE WARMER MAV ON MONDAY AS NOTED ABOVE MOST OF THE AREA WILL BE IN BETWEEN SYSTEMS DURING THE DAY. STUCK CLOSE TO MODEL BLEND FOR MUCH OF THE REST OF THE PERIOD. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... ISSUED AT 308 PM EDT SUN JUN 10 2012 HIGH PRESSURE OVER THE GREAT LAKES WILL SLOWLY MAKES ITS WAY TOWARDS NEW ENGLAND KEEPING CONDITIONS DRY THROUGHOUT THE PERIOD. THE GFS AND CANADIAN DEPICT A WEAK WAVE AND ASSOCIATED VORT MAX POSSIBLY IMPACTING THE AREA ON SUNDAY. HOWEVER...MODELS CURRENTLY INDICATE PRECIPITATION CHANCES NOT EXPECTED TO IMPACT THE AREA UNTIL SUNDAY NIGHT AT THE EARLIEST. THEREFORE...REMOVED ALLBLEND SLIGHT CHANCE POPS AND CONTINUED WITH AN ENTIRELY DRY FORECAST FOR THE LONG TERM. TEMPERATURES WILL START OUT NEAR NORMAL VALUES AND GRADUALLY INCREASE THROUGHOUT THE PERIOD ALLOWING ABOVE NORMAL VALUES TO RETURN. && .AVIATION /DISCUSSION FOR THE 110000Z TAFS/... ISSUED AT 630 PM EDT SUN JUN 10 2012 MID LEVEL DISTURBANCE CURRENTLY LOCATED OVER THE LOWER MISSISSIPPI VALLEY EXPECTED TO DRIFT TO THE NORTHEAST TONIGHT...AND BEGIN MOVING INTO THE LOCAL AREA AROUND SUNRISE MONDAY BASED ON SHORT TERM MODEL DATA. CEILINGS SHOULD GRADUALLY LOWER TONIGHT AS MOISTURE ADVECTS IN...PROBABLY FALLING BELOW 050 SOMETIME AFTER 110600Z. SCATTERED SHOWER ACTIVITY EXPECTED TO DEVELOP AFTER ABOUT 110900Z AS DISTURBANCE APPROACHES. LIFT APPEARS RATHER DISORGANIZED AND MAIN RIBBON OF 850MB FLOW LOOKS TO SET UP EAST OF THE TAF SITES...SO DON/T THINK ANY RAINFALL LATE TONIGHT WILL BE HEAVY ENOUGH TO RESULT IN IFR VISIBILITY RESTRICTIONS. MARGINAL ELEVATED INSTABILITY PROGGED TO MOVE INTO THE AREA LATE TONIGHT...BUT WITHOUT ANY SIGNIFICANT FORCING...THREAT OF ANY LIGHTNING ACTIVITY NEAR THE TAF SITES LOOKS RATHER LOW. LINGERING SURFACE WIND GUSTS EXPECTED TO DIMINISH OVER THE NEXT COUPLE OF HOURS AS MIXING ENDS WITH SUNSET. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...50 NEAR TERM...RYAN SHORT TERM...50 LONG TERM....HOMANN/50 AVIATION...JAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
1037 PM EDT SUN JUN 10 2012 .UPDATE... ISSUED AT 1036 PM EDT SUN JUN 10 2012 LATEST NAM AND RUC HAVE REALLY BACKED OFF ON PRECIPITATION ACROSS SOUTHEAST KENTUCKY THROUGH THE REMAINDER OF THE NIGHT. THIS MAY BE DUE TO THE CONTINUED DOWNSLOPING (DRYING) FLOW. IF THIS IS THE CASE...MUCH OF THE AREA MAY GET ROBBED OVERNIGHT. HOWEVER...AREAS ALONG AND NORTH OF THE MOUNTAIN PARKWAY MAY NOT FEEL THIS INFLUENCE AS MUCH WITH DEWPOINTS POOLING A BIT HIGHER ACROSS THE AREA. THUS...THE NAM DEPICTION OF A BAND OF PRECIPITATION FORMING ACROSS OUR NORTH SEEMS REASONABLE AND WILL DRIFT NORTH TOWARDS DAYBREAK INTO NORTHERN KENTUCKY. MEANWHILE...LOW LEVEL JET WILL LIKELY BLOSSOM AN AREA OF SHOWERS ACROSS CENTRAL TENNESSEE LATE TONIGHT AND THESE WILL LIKELY PUSH NORTH ALONG THE I-75 CORRIDOR THROUGH DAYBREAK AND BEYOND. AGAIN...NOT SURE HOW MUCH INFLUENCE COULD BE ATTRIBUTED TO THE DOWNSLOPING FLOW...BUT THE EVOLUTION OF THIS SYSTEM WILL NEED TO BE WATCHED AS IT TOO COULD FALL APART AND BECOME MORE SCATTERED SHOWERS OR SPRINKLES AT BEST. REGARDLESS...STILL A BIT OF A CHANCE WE COULD END UP STAYING DRY IN SEVERAL AREAS THROUGH DAYBREAK AND PERHAPS WELL INTO MONDAY AS WELL. UPDATE ISSUED AT 806 PM EDT SUN JUN 10 2012 LOOKING AT ALL AVENUES IN WHICH WE COULD ACHIEVE THUNDER TONIGHT CAME BACK NEGATIVE. LIFTING PARCELS FROM MANY DIFFERENT LEVELS COULD NOT GENERATE ENOUGH INSTABILITY TO WARRANT THUNDER LATE TONIGHT. THIS IS SUPPORTED BY THE LACK OF LIGHTNING UPSTREAM. ALTHOUGH WE ARE ANTICIPATING NEW DEVELOPMENT...IT WILL LIKELY TRANSITION INTO MORE RAIN SHOWERS. IT WOULD TAKE SOME PRETTY VIGOROUS UPDRAFTS TO GET MOISTURE ABOVE THE VERY HIGH FREEZING LEVEL...THUS...FEEL SAFE REMOVING THUNDER. STILL NOT CONFIDENT TO GO ANY HIGHER WITH POPS...BUT WE MAY NEED TO GO HIGHER WITH A LATER UPDATE IF THINGS BEGIN TO DEVELOP AS EXPECTED. HOWEVER...AT THIS TIME...PREFER TO WAIT AND SEE AND STICK WITH OUR 60 TO 70 POPS. IT STILL LOOKS LIKE SHOWERS SHOULD BEGIN TO DEVELOP NEAR THE TENNESSEE BORDER AROUND 1 OR 2 AM...THEN SPREAD NORTHWARD...REACHING THE I-64 CORRIDOR BY 4 OR 5 AM...AND INTO NORTHERN KENTUCKY AROUND DAYBREAK. AFTER THE INITIAL SURGE OF MOISTURE AND RAIN...IT APPEARS WE COULD DRY OUT BEHIND THIS FEATURE TOMORROW MORNING...LEADING TO A DRIER PERIOD DURING THE MID MORNING HOURS. THEN WE MAY HAVE TO WAIT FOR DAYTIME INSTABILITY TO REFIRE THINGS IN THE AFTERNOON IF WE DON`T HAVE TOO MANY CLOUDS AROUND TO PREVENT THE DEVELOPMENT OF INSTABILITY. REGARDLESS...STILL PLENTY OF QUESTIONS SWIRLING AROUND TOMORROW`S FORECAST. GOING TO HOLD OFF TO MAKE ANY CHANGES AS MUCH WILL BE DETERMINED IN THE NEXT 6 TO 12 HOURS. UPDATE ISSUED AT 524 PM EDT SUN JUN 10 2012 DECIDED TO INTRODUCE A FEW HOURS OF SPRINKLES FOR AREAS SOUTH OF THE HAL ROGERS PARKWAY FOR THIS EVENING. CEILINGS ARE AROUND 5KFT...SO I IMAGINE A FEW DROPS ARE MAKING IT TO THE SURFACE. STILL LOOKS LIKE THE BEST FORCING WITH THE MAIN PRECIPITATION WILL HOLD OFF UNTIL AROUND OR SHORTLY AFTER MIDNIGHT. THE TARGETED AREAS EARLY...WILL BE NEAR THE TENNESSEE BORDER WITH THE THREAT FOR RAIN PUSHING INTO NORTHERN KENTUCKY TOWARDS DAYBREAK. DOWNSLOPING MAY KEEP INITIAL PRECIPITATION TOTALS ON THE LIGHT SIDE AND PERHAPS NOT EVEN MEASURABLE ACROSS SOUTHEAST KENTUCKY...BUT EVENTUALLY THE FORCING SHOULD WIN OUT. LOWER CLOUD DECK HAS BROUGHT SOME EARLIER COOLING INTO OUR SOUTHERN COUNTIES...SO HAVE ADJUSTED THE HOURLY TEMPERATURE TRACE TO REFLECT THIS EARLIER COOLING. NO NEED TO UPDATE ZONES WITH ANY OF THESE CHANGES. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 259 PM EDT SUN JUN 10 2012 EASTERN KENTUCKY REMAINS SANDWICHED BETWEEN AN AREA OF SURFACE HIGH PRESSURE SITUATED OFF OF THE CAROLINA COAST...AND OCCLUDING LOW PRESSURE ACROSS SOUTH CENTRAL CANADA...LINKED TO A NEARLY STATIONARY FRONT ALIGNED NORTH TO SOUTH ALONG THE PLAINS. ALOFT...PLENTIFUL MOISTURE HAS BEEN FEEDING IN FROM THE SOUTHWEST OUT AHEAD OF A SLOW- MOVING SHORT WAVE TROUGH THAT HAS BEEN PLAGUING THE GULF COAST FOR THE PAST FEW DAYS. MEANWHILE...A MORE STOUT UPPER LEVEL TROUGH IS MOVING EAST ALONG THE U.S./CANADIAN BORDER. DOWNSLOPING SOUTHEASTERLY WINDS HAVE BEEN SCOURING OUT ANY PRECIPITATION THAT HAS TRIED TO MAKE IT IN FROM THE SOUTH TODAY...WITH ONLY A FEW SPRINKLES NOTED THUS FAR. THIS TREND LOOKS TO CONTINUE THROUGH THIS EVENING. THE MODELS ARE IN GOOD AGREEMENT WITH SLOWLY LIFTING THE GULF WAVE THROUGH THE TENNESSEE AND OHIO VALLEYS OVER THE NEXT 24 TO 36 HOURS AS IT GETS GRADUALLY INGESTED INTO THE MAIN WESTERLIES BY THE MORE DOMINATE NORTHERN STREAM WAVE. THIS WILL BRING ROUNDS OF SHOWERS AND ISOLATED TO SCATTERED THUNDER TO THE AREA BEGINNING LATER TONIGHT AND THROUGH THE DAY ON TUESDAY AS DEEP MOISTURE WILL BE IN PLACE...WITH PERIODS OF WEAK TO MODEST FORCING. DESPITE VERY HIGH PWATS FOR THIS TIME OF YEAR...AS HAS BEEN PREVIOUSLY NOTED...INSTABILITY CONTINUES TO BE IN QUESTION WITH SO MUCH CLOUD COVER...SO AM NOT CONFIDENT THAT THESE VALUES WILL BE REALIZED. STILL...WITH THIS KIND OF PATTERN IN PLACE...IT CERTAINLY CONTINUES TO BEAR WATCHING FOR LOCALLY HEAVY RAINERS. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 259 PM EDT SUN JUN 10 2012 LONG RANGE MODELS SHOW A RATHER BAGGY LONGWAVE PATTERN OVER THE SOUTHERN APPALACHIANS THROUGH THE REST OF THE WORK WEEK. BY THE WEEKEND...SOME AMPLIFICATION OCCURS AT 500 MB WITH RIDGING TAKING SHAPE OVER THE UPPER MIDWEST AND GREAT LAKES WHILE STUBBORN TROUGHINESS HANGS IN ALONG THE EASTERN SEABOARD. THE COLD FRONT AND UPPER LEVEL LOW WHICH WILL BRING THE EARLY WEEK RAINS WILL BE OFF TO OUR EAST BY TUESDAY NIGHT AND BROAD...WEAK HIGH PRESSURE WILL BUILD INTO THE APPALACHIANS FOR THE DURATION OF THE PERIOD. SENSIBLE WEATHER WILL FEATURE A FEW LINGERING SHOWERS TUESDAY NIGHT BEHIND OUR DEPARTING FRONTAL SYSTEM. THE REST OF THE PERIOD WILL LIKELY BE PRECIP FREE FOR MOST FOLKS AS A DRY NORTHEASTERLY FLOW DOMINATES. A FEW WEAK DISTURBANCES RETROGRADING TO THE SOUTHWEST UNDER THE BUILDING RIDGE OVER THE GREAT LAKES MAY KICK OFF AN ISOLATED SHOWER FRIDAY THROUGH SUNDAY. HOWEVER...SURFACE DEWPOINTS WILL BE FAIRLY LOW AND PWATS ONLY REBOUND TO AROUND AN INCH SO MODELS MAY BE OVERDOING THE QPF...AT LEAST ON THIS SIDE OF THE APPALACHIAN SPINE. AS SUCH...HAVE TRIMMED BACK ANY MENTION OF PRECIP TO JUST THE HIGHER TERRAIN AREAS ALONG THE TN AND VA BORDERS. TEMPERATURES ARE EXPECTED TO REMAIN PRETTY MUCH NEAR NORMAL THROUGH THE PERIOD...AND WITH COMFORTABLE DEWPOINTS. OVERNIGHT LOWS WILL LIKELY SNEAK INTO THE 50S MOST NIGHTS IN THE VALLEYS AS WELL. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 806 PM EDT SUN JUN 10 2012 CONDITIONS WILL START VFR OVERNIGHT AS LOW CLOUDS CONTINUE TO BE EATEN AWAY BY SOUTHEAST DOWNSLOPING WINDS OFF THE HIGHER TERRAIN. A BAND OF PRECIPITATION WILL DEVELOP AND SPREAD NORTHWARD LATE TONIGHT...BRINGING LOWERING CEILINGS AND EVENTUALLY THE THREAT OF SOME MVFR CIGS TO MUCH OF THE AREA TOWARDS DAYBREAK. AT THIS TIME...STILL PLENTY OF UNCERTAINTY ON HOW EXTENSIVE THE LOW CLOUDS WILL BE AS THE SOUTHEAST WINDS COULD PERSIST AND KEEP THEM OUT MUCH LONGER. HOWEVER...THESE LOWER CIGS COULD MAKE SOME HEAD WAY INTO THE I-75 CORRIDOR BY DAYBREAK...SO WILL BRING SOME MVFR CIGS INTO KSME AND KLOZ TOWARDS DAYBREAK AND HOLD OFF AT KJKL WITH JUST A LOW SCATTERED DECK. GOING TO COVER MUCH OF TOMORROW WITH VCTS...AS THE DEVELOPMENT AND PLACEMENT OF ANY CONVECTION REMAINS VERY UNCERTAIN AT THIS TIME. IT APPEARS THE GREATEST THREAT WILL BE AT KSME AS THEY WILL BE LEAST IMPACTING BY ANY DOWNSLOPING AND MAY BE UNDER THE THREAT OF SHOWERS AND STORMS FOR MUCH OF THE AFTERNOON HOURS...WHILE FURTHER EAST REMAINS MORE OF A QUESTION MARK AT THIS TIME. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KAS SHORT TERM...GEOGERIAN LONG TERM....ABE AVIATION...KAS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1240 AM EDT SAT JUN 9 2012 .SYNOPSIS... A COLD FRONT WILL CROSS THE REGION OVERNIGHT. SHOWERS WILL CONTINUE ACROSS EXTREME EASTERN PORTIONS OF THE REGION EARLY SATURDAY WITH HIGH PRESSURE CREATING FAIR WEATHER FOR THE REMAINDER OF THE REGION. && .NEAR TERM /THROUGH SATURDAY/... UPDATE...KEPT TSTMS IN THE FCST LAPS/RUC SOUNDINGS SUPPORT SOME ELEVATED INSTABILITY ACROSS THE NORTH AND EAST. LTG DETECTION SHOWING STRIKES IN THE AFOREMENTIONED AREAS. ADDED FOG EVERYWHERE THROUGH THE MORNING HRS. QPF WAS ADJUSTED USING THE LATEST BUCKETS AND BLENDING IN THE GEM AND GFS WHICH SUPPORTS 2 AREAS OF HEAVIER RAINFALL ACROSS THE NORTH AND EXTREME EASTERN AREAS. PREV DISC: CONVECTION DUE TO DAYTIME HEATING AND UNSTABLE ATMOSPHERE HAS ALREADY DEVELOPED ACROSS WESTERN MAINE AND SHOULD CONTINUE TO MOVE EAST THROUGH MAINLY NORTHERN AND CENTRAL SECTIONS THE REMAINDER OF THIS AFTERNOON. NEW RUC HAS CAPE VALUES APPROACHING 1000 J/KG BUT CAPE REMAINS SKINNY. SHEAR NOT VERY IMPRESSIVE SO STILL EXPECTING THE SEVERE THREAT TO REMAIN LOW BUT SOMETHING TO WATCH FOR THIS AFTERNOON. WITH FREEZING LEVEL ONLY AROUND 8K, SMALL HAIL IS POSSIBLE MAINLY THIS AFTERNOON ACROSS CENTRAL AND NORTHERN SECTIONS. HRRR AND RUC MODEL INDICATE THIS FIRST AREA OF CONVECTION WILL MOVE EAST OF THE REGION BUT IMPRESSIVE SHORTWAVE TROUGH JUST SOUTH OF JAMES BAY WILL CROSS THE STATE TONIGHT WITH ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS. PW OVER 1 INCH SO POTENTIAL FOR RAINFALL AMOUNTS EXCEEDING 1 INCH IN ANY STRONGER SHOWERS AND THUNDERSTORMS THROUGH TONIGHT. BASIN AVERAGES APPEARS TO BE AROUND .25 ACROSS DOWNEAST WITH OVER HALF OF AN INCH ACROSS THE NORTH BUT AGAIN HIGHER AMOUNTS IN ANY DOWNPOURS. COLD FRONT WILL EXIT THE STATE LATE TONIGHT WITH IMPROVING CONDITIONS FROM WEST TO EAST. SHOWERS MAY LINGER ACROSS EASTERN SECTIONS BORDERING NEW BRUNSWICK SATURDAY MORNING AND SLOWLY DIMINISH BY SATURDAY AFTERNOON. THE REMAINDER OF THE FORECAST AREA WILL SEE MOSTLY TO PARTLY SUNNY SKIES ON SATURDAY AS HIGH PRESSURE BUILDS IN FROM THE WEST.&& .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... THE UPPER LEVEL TROF WILL BE MOVING EAST SATURDAY NIGHT THROUGH SUNDAY. AN UPPER RIDGE WILL START TO BUILD ACROSS THE REGION SUNDAY THROUGH MONDAY. THIS WILL RESULT IN MAINLY SUNNY DAYS AND CLEAR MILD NIGHT NIGHTS SUNDAY NIGHT THROUGH TUESDAY. TEMPERATURES WILL CONTINUE TO MODERATE EACH DAY. HIGH ON SUNDAY WILL BE IN THE MID TO UPPER 70S AND THEN MODERATE INTO THE UPPER 70S TO AROUND 80 ON MONDAY. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... THE UPPER LEVEL RIDGE AXIS WILL CREST ACROSS THE REGION MONDAY NIGHT THROUGH TUESDAY. EXPECT MOSTLY SUNNY CONDITIONS ON TUESDAY. TEMPERATURES ON TUESDAY WILL CONTINUE TO WARM EVEN FURTHER WITH HIGHS IN THE LOW TO MID 80S NORTH AND UPPER 70S TO NEAR 80 DOWNEAST ON TUESDAY. A SHORT WAVE WILL APPROACH FROM THE WEST WEDNESDAY AND SLOWLY CROSS THE REGION THROUGH FRIDAY. THIS WILL BRING AN INCREASING CHANCE FOR SHOWERS LATER WEDNESDAY INTO THE LATER PORTION OF THE WORK WEEK. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... NEAR TERM: VFR CONDITIONS BUT LOWER IN SHOWERS AND THUNDERSTORMS THROUGH TONIGHT. AREAS OF FOG WILL REDUCE CONDITIONS ACROSS DOWNEAST BETWEEN 07-12Z SATURDAY MORNING. SHORT TERM: MAINLY VFR CONDITIONS SATURDAY NIGHT THROUGH WEDNESDAY. && .MARINE... NEAR TERM: WINDS AND SEAS BELOW SCA CRITERIA TONIGHT AND SATURDAY. HOWEVER, FOG WILL KEEP VSBY BELOW 1 NM TONIGHT WITH IMPROVING CONDITIONS AFTER FRONTAL PASSAGE LATE TONIGHT. SHORT TERM: WINDS/SEAS WILL BE BELOW SCA LEVELS THROUGH THE PERIOD. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT/KHW SHORT TERM...DUDA LONG TERM...DUDA AVIATION...HEWITT/KHW MARINE...HEWITT/KHW/DUDA
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
255 PM EDT SAT JUN 9 2012 .SYNOPSIS... HIGH PRESSURE, CENTERED OVER VIRGINIA, WILL PROVIDE THE UPPER OHIO VALLEY WITH WARM AND MAINLY DRY CONDITIONS THIS WEEKEND. A COLD FRONT, MOVING SLOWLY EAST FROM THE DAKOTAS, WILL BRING HIGHER HUMIDITY MONDAY, AND THUNDERSTORMS MONDAY NIGHT AND TUESDAY. && .NEAR TERM /THROUGH SUNDAY/... WILL CONTINUE TO ONLY MENTION A SLIGHT CHANCE OF THUNDERSTORMS FOR FOREST COUNTY AND NORTHERN JEFFERSON COUNTY PA THROUGH EARLY EVENING. RECENT SATELLITE DATA AND RAP MODEL OUTPUT CONTINUE TO SHOW A DEVELOPING BAND OF POTENTIALLY SCATTERED THUNDERSTORMS TO MOVE THROUGH NORTH CENTRAL PENNSYLVANIA. SREF MODEL OUTPUT CONTINUES TO SHOW HIGH PRESSURE, CENTERED OVER VIRGINIA, WILL PROVIDE SUFFICIENT SUBSIDENCE FOR NO MORE THAN SCATTERED CLOUD DEVELOPMENT THIS PERIOD. PER BLEND OF RECENT GFS AND NAM MOS AND SREF MODEL OUTPUT, LOWS TONIGHT WILL BE NEAR OR SLIGHTLY WARMER THAN NORMAL. EXPECT HIGHS 6 TO 8 DEGREES WARMER THAN NORMAL SUNDAY AFTERNOON. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... RECENT SREF MODEL OUTPUT CONTINUES TO SHOW COLD FRONTAL SYSTEM WILL MOVE SLOWLY EASTWARD FROM THE DAKOTAS. THIS WILL INDUCE SOUTHERLY LOW LEVEL WINDS WITH AN INFLUX OF GULF MOISTURE ACROSS THE EASTERN U.S. AND ADDITIONAL UPPER LEVEL RIDGE BUILDING. HENCE EXPECT MORE HUMID CONDITIONS MONDAY ACROSS THE UPPER OHIO VALLEY. LOW TEMPERATURES SUNDAY NIGHT CAN BE SLIGHTLY WARMER THAN NORMAL. HIGH TEMPERATURES MONDAY AFTERNOON MAY NOT BE AS WARM AS SUNDAY DUE TO INCREASED CUMULUS DEVELOPMENT. THE INCREASED LOW LEVEL HUMIDITY MAY ALSO PRODUCE ENOUGH INSTABILITY FOR LATE DAY THUNDERSTORM DEVELOPMENT. CONCUR WITH BLEND OF RECENT SREF AND NAEFS MODEL OUTPUT THAT PREFRONTAL THUNDERSTORMS WILL INCREASE IN COVERAGE ACROSS THE UPPER OHIO VALLEY MONDAY NIGHT AND TUESDAY. DUE TO INCREASED LOW LEVEL HUMIDITY AND DEEP LAYER WIND SHEAR, THE THUNDERSTORMS HAVE POTENTIAL TO DELIVER BOUTS OF HEAVY RAIN AND GUSTY WIND. HOWEVER, ITS POSSIBLE THE COLD FRONT WILL PAST EAST OF THE UPPER OHIO VALLEY DURING TUESDAY AFTERNOON, SO DO NOT HAVE ENOUGH CONFIDENCE TO MENTION AT THIS JUNCTURE. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... A COLD FRONT WILL DEFINITELY BE EAST OF THE UPPER OHIO VALLEY BY LATE TUESDAY NIGHT. SHOWERS AND THUNDERSTORMS WILL DECREASE TO SCATTERED COVERAGE TUESDAY NIGHT AND GRADUALLY END FROM WEST TO EAST ON WEDNESDAY. SURFACE HIGH PRESSURE IS PROGGED TO BUILD ACROSS THE GREAT LAKES REGION AND BRING A RETURN TO DRY WEATHER FOR THE LATTER HALF OF THE WEEK. TEMPERATURES ARE FORECAST TO BE A FEW DEGREES ABOVE NORMAL FOR THE EXTENDED PERIOD...CLOSE TO HPC GUIDANCE. && .AVIATION /19Z SATURDAY THROUGH THURSDAY/... EXPECT AREAS OF SHOWERS ASSOCIATED WITH WEAK SHORT WAVE IN NORTHWEST FLOW ALOFT TO REMAIN NORTH AND EAST OF OUR TERMINAL LOCATIONS THIS AFTERNOON. VFR CONDITIONS SHOULD PREVAIL THROUGH THE TAF PERIOD WITH SCATTERED CUMULUS DISSIPATING SHORTLY AFTER SUNSET AND REDEVELOPING BY MID MORNING SUNDAY. .OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY... GENERALLY VFR WEATHER SHOULD HOLD INTO EARLY MONDAY. SOUTHERLY RETURN FLOW WILL BRING LOW LEVEL MOISTURE NORTHWARD INTO THE UPPER OHIO VALLEY BY LATE MONDAY WHILE A COLD FRONT APPROACHES FROM THE MIDWEST. SCATTERED SHOWERS AND THUNDERSTORMS MONDAY AFTERNOON WILL BECOME MORE NUMEROUS BY MONDAY NIGHT INTO TUESDAY AS MOISTURE INCREASES AND THE FRONTAL BOUNDARY SLOWLY CROSSES THE REGION. RESTRICTIONS WILL BE LIKELY. SURFACE HIGH PRESSURE WILL BUILD ACROSS THE GREAT LAKES AND BRING A DRYING TREND AND GENERALLY VFR CONDITIONS LATE WEDNESDAY AND THURSDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1224 PM EDT SAT JUN 9 2012 .SYNOPSIS... HIGH PRESSURE, CENTERED OVER VIRGINIA, WILL PROVIDE THE UPPER OHIO VALLEY WITH WARM AND MAINLY DRY CONDITIONS THIS WEEKEND. A COLD FRONT, MOVING SLOWLY EAST FROM THE DAKOTAS, WILL BRING HIGHER HUMIDITY MONDAY, AND THUNDERSTORMS MONDAY NIGHT AND TUESDAY. && .NEAR TERM /THROUGH SUNDAY/... WILL CONTINUE TO ONLY MENTION A SLIGHT CHANCE OF THUNDERSTORMS FOR FOREST COUNTY AND NORTHERN JEFFERSON COUNTY PA LATE THIS AFTERNOON, BASED ON RECENT SATELLITE DATA AND RAP MODEL OUTPUT. RAP AND CONSENSUS OF SREF MODEL OUTPUT SHOW HIGH PRESSURE, CENTERED OVER VIRGINIA, WILL PROVIDE SUFFICIENT SUBSIDENCE FOR NO MORE THAN SCATTERED CLOUD DEVELOPMENT THIS PERIOD. SUBSEQUENT SURFACE WARMING WILL CAUSE HIGHS TO BE 4 TO 7 DEGREES WARMER THAN NORMAL THIS AFTERNOON, AND 6 TO 10 DEGREES WARMER THAN NORMAL SUNDAY AFTERNOON. LOWS TONIGHT WILL BE NEAR OR SLIGHTLY WARMER THAN NORMAL, PER BLEND OF RECENT GFS AND NAM MOS AND SREF MODEL OUTPUT. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY/... RECENT SREF MODEL OUTPUT CONTINUES TO SHOW COLD FRONTAL SYSTEM WILL MOVE SLOWLY EASTWARD FROM THE DAKOTAS. THIS WILL INDUCE SOUTHERLY LOW LEVEL WINDS ACROSS THE EASTERN U.S. AND ADDITIONAL UPPER LEVEL RIDGE BUILDING. HENCE EXPECT MONDAY ACROSS THE UPPER OHIO VALLEY TO BE WARMER AND MORE HUMID. AFTERNOON HIGHS MAY BRUSH 90 OVER LOWER ELEVATIONS SOUTH DEPENDING ON EXTENT OF AFTERNOON CUMULUS DEVELOPMENT AND COVERAGE OF LATE DAY THUNDERSTORMS. GENERALLY WENT WITH GFS AND NAM MOS VALUES THAT FORECASTED LOWS SUNDAY NIGHT UP TO 5 DEGREES WARMER THAN NORMAL AND HIGHS FOR MOST LOCALES NO WARMER THAN THE UPPER 80S. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... INCREASED COVERAGE OF STORMS CAN BE ANTICIPATED FOR MONDAY NIGHT AND TUESDAY WITH THE APPROACH AND PASSAGE OF THE AFOREMENTIONED UPPER TROF AND COLD FRONT. BUILDING HIGH PRESSURE IS FORECAST TO RETURN DRY WEATHER FOR THE LATTER HALF OF THE WEEK. OVERALL LONG TERM TEMPERATURES WERE FORECAST AT...OR ABOVE NORMAL USING TWEAKED HPC GUIDANCE. && .AVIATION /16Z SATURDAY THROUGH WEDNESDAY/... VFR CONDITIONS SHOULD CONTINUE DUE TO NEARBY HIGH PRESSURE. A SHORTWAVE TROUGH MOVING OVER THE GREAT LAKES COULD BRING A SHRA OR TSRA INTO NORTHWESTERN PA THIS AFTERNOON. AT THIS POINT WILL KEEP MENTION OUT OF NORTHERN TAF SITES AS CONFIDENCE ON RESTRICTIONS AT THOSE SITES IS RELATIVELY LOW. ELSEWHERE...CONDITIONS SHOULD REMAIN VFR THROUGH THE PERIOD. .OUTLOOK...TONIGHT THROUGH WEDNESDAY... SURFACE HIGH PRESSURE WILL SUPPORT GENERALLY VFR CONDITIONS FOR SUNDAY INTO EARLY MONDAY. RETURN FLOW WILL BRING LOW LEVEL MOISTURE NORTHWARD INTO THE UPPER OHIO VALLEY BY LATE MONDAY. A COLD FRONT WILL SLOWLY CROSS THE REGION TUESDAY THROUGH WEDNESDAY AND WILL GENERATE NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS. RESTRICTIONS WILL BE LIKELY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
857 AM EDT SAT JUN 9 2012 .SYNOPSIS... MOSTLY DRY AND WARM CONDITIONS CAN BE EXPECTED WITH HIGH PRESSURE BUILDING OVER THE REGION THIS WEEKEND. THE NEXT CHANCE FOR SIGNIFICANT RAIN WILL COME MONDAY AND TUESDAY AS A FRONTAL BOUNDARY MOVES ACROSS THE AREA. && .NEAR TERM /THROUGH TONIGHT/... PER RECENT RAP MODEL OUTPUT, THAT SHOWED TRACK OF ANY DEVELOPING BAND OF SCATTERED THUNDERSTORMS THIS AFTERNOON TO BE FURTHER NORTH AND EAST, HAVE LIMITED SLIGHT CHANCE OF LATE AFTERNOON THUNDERSTORMS TO FOREST COUNTY AREA. OTHERWISE HIGH PRESSURE OVER VIRGINIA WILL PROVIDE DRY AND WARM CONDITIONS FOR THE UPPER OHIO VALLEY THIS PERIOD. SPECIFIC TEMPERATURES WHERE FORECAST USING A BLEND OF SREF AND LATEST GFS MOS. && .SHORT TERM /SUNDAY THROUGH MONDAY/... AS WRN STATES TROF DIGS EASTWARD...EASTERN CONUS TROF WL BE AMPLIFYING FOR THE START OF THE NEW WEEK. FURTHER MODERATION OF TEMPERATURE MAY THUS BE ANTICIPATED ALONG WITH A GRADUAL INCREASE IN HUMIDITY THROUGH MONDAY AS MOISTURE ADVECTION INCREASES OVR THE UPR OH DUE TO THE EASTWARD DEVELOPMENT OF THE RIDGE AXIS. THE NEXT CHC FOR SHRA AND TSRA IS FORECAST FOR MONDAY AS THAT MOISTURE AND WARMTH IMPROVES THE INSTABILITY PROFILE AND INTERACTS WITH A GFS- NAM-PROGGED SHORTWAVE IN SW FLOW. THE SHORT TERM TEMPERATURE FORECAST WAS CONSTRUCTED USING TWEAKED...AND GENERALLY CONSISTENT GFS MOS NUMBERS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... INCREASED COVERAGE OF STORMS CAN BE ANTICIPATED FOR MONDAY NIGHT AND TUESDAY WITH THE APPROACH AND PASSAGE OF THE AFOREMENTIONED UPR TROF AND COLD FRONT. BUILDING HIGH PRESSURE IS FORECAST TO RETURN DRY WEATHER FOR THE LATTER HALF OF THE WEEK. OVERALL LONG TERM TEMPERATURES WERE FORECAST AT...OR ABOVE NORMAL USING TWEAKED HPC GUIDANCE. && .AVIATION /13Z SATURDAY THROUGH WEDNESDAY/... VFR CONDITIONS SHOULD CONTINUE THIS MORNING AS HIGH PRESSURE REMAINS OVERHEAD. A SHORTWAVE MOVING OVER THE GREAT LAKES COULD BRING A SHRA OR TSRA INTO NORTHWESTERN PA THIS AFTERNOON. AT THIS POINT WILL KEEP MENTION OUT OF NORTHERN TAF SITES AS CONFIDENCE ON RESTRICTIONS AT THOSE SITES IS RELATIVELY LOW. ELSEWHERE...CONDITIONS SHOULD REMAIN VFR THROUGH THE PERIOD. .OUTLOOK...TONIGHT THROUGH WEDNESDAY... SURFACE HIGH PRESSURE WILL SUPPORT GENERALLY VFR CONDITIONS FOR SUNDAY INTO EARLY MONDAY. RETURN FLOW WILL BRING LOW LEVEL MOISTURE NORTHWARD INTO THE UPPER OHIO VALLEY BY LATE MONDAY. A COLD FRONT WILL SLOWLY CROSS THE REGION TUESDAY THROUGH WEDNESDAY AND WILL GENERATE NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS. RESTRICTIONS WILL BE LIKELY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
319 PM EDT SAT JUN 9 2012 .SYNOPSIS... ISSUED AT 319 PM EDT SAT JUN 9 2012 VERY WARM AND INCREASINGLY HUMID CONDITIONS CAN BE EXPECTED FOR THE AREA AS WE CONTINUE THROUGH THE WEEKEND. THE AREA WILL REMAIN DRY AS AN AREA OF HIGH PRESSURE REMAINS OVER THE AREA. THE THREAT OF SHOWERS AND STORMS WILL INCREASE BEGINNING ON MONDAY WITH THE BEST CHANCE EXPECTED TO BE ON MONDAY NIGHT AS A FRONT COMES THROUGH THE AREA. SEVERE WEATHER IS NOT LIKELY...ALTHOUGH AN ISOLATED SEVERE STORM CAN NOT BE RULED OUT. RAIN CHANCES ARE THEN EXPECTED TO END EARLY ON TUESDAY AS THE COLD FRONT EXITS THE AREA TO THE SOUTHEAST. COOLER AIR WILL FILTER IN FOR MID WEEK. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 319 PM EDT SAT JUN 9 2012 MAIN CHALLENGES IN THE SHORT TERM ARE DETERMINING TIMING FOR SHOWERS AND STORMS TO MOVE IN ACROSS THE AREA...AND ALSO SEVERE POTENTIAL WITH THE FRONTAL PASSAGE MON NIGHT/TUE. MAIN CHANGES TO THE FCST ARE INCREASING THE CHC OF RAIN FOR MON A BIT AND LOWERING TEMPS SOME AS A RESULT. QUIET WEATHER ALONG WITH VERY WARM AND INCREASING HUMID CONDITIONS CONTINUES TO BE EXPECTED THROUGH THE REMAINDER OF THIS WEEKEND. UPPER RIDGE AXIS OVER THE UPPER MISSISSIPPI VALLEY THIS AFTERNOON WILL ONLY SLOWLY CRAWL TO THE EAST THROUGH LATE SUNDAY. THIS RIDGE ALONG WITH THE WARM TEMPERATURES ADVECTING IN THE LOW-MID LEVELS WILL HELP TO PREVENT ANY CLOUD COVER ACROSS THE AREA. DEW POINTS INCREASING TONIGHT ALONG WITH A SLIGHT BREEZE REMAINING UP WILL ALLOW FOR LOW TEMPS TO BE A COUPLE DEGREES WARMER TONIGHT. THIS HEAD START IN TEMPS ALONG WITH H850 TEMPS WARMING INTO THE UPPER TEENS C WILL HELP TEMPS INTO THE LOWER 90S ON SUN. SOME UNCERTAINTY HAS CREPT INTO THE FCST WITH REGARDS TO THE TIMING OF THE GULF COAST UPPER LOW LIFTING NORTH INTO THE AREA. IT HAS BEEN SHOWN TO MOVE IN DURING THE DAY ON MON...HOWEVER THE 00Z EURO NOW SHOWS THE WAVE MOVING IN BEGINNING LATE SUNDAY NIGHT AND BRINGING PCPN IN. ALL OF THE OTHER 12Z MODELS HAVE FOLLOWED CONTINUITY WITH THEIR PREVIOUS RUNS AND SHOW PCPN MOVING IN WITH THIS WAVE ON MON. IT APPEARS THAT A WEAK LEAD SHORT WAVE WILL APPROACH THE AREA AROUND 12Z MON WITH ALL OF THE MODELS...HOWEVER THE SUFFICIENT MOISTURE AND MAIN WAVE WILL BE DOWN ACROSS CENTRAL AND SRN INDIANA STILL AT 12Z. WE WILL HOLD ON TO A DRY FCST FOR NOW FOR SUN NIGHT WITH THIS IN MIND. THE THREAT OF SHOWERS AND STORMS WILL INCREASE THROUGH THE DAY ON MON FROM SOUTH TO NORTH...AND THEN EVEN MORE MON NIGHT FROM WEST TO EAST. WE WILL SEE THE MAIN ENERGY AND DEEPER MOISTURE WITH THE SRN LOW MOVE ACROSS THE AREA DURING THE DAY ON MON. IT WILL BE WEAKENING...AND WE ARE NOT SURE HOW MUCH COVERAGE WE WILL SEE ON MON. IT DOES APPEAR THOUGH THAT WE WILL SEE MORE CLOUD COVER AND CHC OF PCPN...SO WE HAVE LOWERED TEMPS A BIT AS A RESULT. DEEP LAYER SHEAR IS RATHER WEAK WITH A WEAK MID LEVEL FLOW...SO SEVERE WEATHER IS NOT LIKELY...EVEN WITH LI/S IN THE -4 TO -6C RANGE AND OVER 1000 J/KG OF CAPE. WE WILL THEN SEE THE FRONT MOVE IN ACROSS THE AREA LATE MON AND MORE SO MON NIGHT...INCREASING THE CHC OF SHOWERS AND STORMS FURTHER. IT APPEARS THAT THE BEST THREAT OF STORMS WITH THE FRONT WILL LIKELY HOLD OFF UNTIL AFTER PEAK HEATING ON MON. PLENTY OF ELEVATED INSTABILITY WILL REMAIN MON NIGHT AHEAD OF THE FRONT AND MOISTURE WILL REMAIN...TO KEEP SOME CONVECTION GOING. THE THREAT OF SEVERE DOES NOT LOOK TO BE WIDESPREAD MON NIGHT WITH THE LIMITED DIURNAL INSTABILITY LEFT. SHEAR PROFILES CONTINUE TO INDICATE THE SUFFICIENT SHEAR WILL LAG THE FRONT A LITTLE. .LONG TERM...(TUESDAY THROUGH SATURDAY) ISSUED AT 319 PM EDT SAT JUN 9 2012 THE MAIN STORY FOR THE EXTENDED FCST PERIOD WILL BE DRY AND PLEASANT WEATHER WITH NO RAINFALL FORESEEN BEYOND TUESDAY MORNING. FRONT WILL BE EXITING THE CWA TUESDAY MORNING AND TAKING THE LEFTOVER SHOWERS WITH IT. MODEL GUIDANCE INDICATES ONLY OUR FAR SE COUNTIES DESERVE MENTION OF LOW POPS DURING TUESDAY MORNING...OTHERWISE EVERYONE WILL LIKELY HAVE DRIED OUT BY THAT POINT. COOLER AIR ADVECTS IN FOR TUESDAY AND WEDNESDAY BUT 850 MB TEMPS ARE NOT EXPECTED TO DIP BELOW THE 9C-10C RANGE...SO WITH MOSTLY SUNNY SKIES THAT SHOULD STILL YIELD HIGHS IN THE MID TO UPPER 70S WITH SOME AREAS AROUND 80F BY THURSDAY. AFTER ZONAL FLOW ALOFT ON WEDNESDAY...EXPECTING SLOW BUILDING OF ANOTHER RIDGE ACROSS THE EASTERN CONUS BY THE END OF NEXT WEEK. THIS PATTERN TRANSITION IS WELL SUPPORTED BY A VARIETY OF MODELS. THE ECMWF ENSEMBLE MEAN 500 MB PLOT FROM 00Z REVEALS GOOD MEMBER SUPPORT OF THE DETERMINISTIC FORECAST...NAMELY HEIGHTS RISING BACK INTO THE 585 DM TO 590 DM RANGE FOR OUR REGION. THE 12Z GFS IS NOT QUITE AS BULLISH BUT STILL RAISES HEIGHTS INTO THE LOW 580S. IN FACT...THE GFS SHOWS A FAIRLY SIGNIFICANT JET CORE COMING INTO THE PACIFIC NW BY NEXT WEEKEND WHICH COULD DIG INTO THE DESERT SW. THIS MAY END UP REINFORCING THE RIDGE DOWNSTREAM. I WOULD EXPECT HIGHS NEXT WEEKEND TO RETURN INTO THE MID 80S AND PERHAPS WARMER. WITH WEAK FLOW AT THE SFC...EXPECT LAKE BREEZES TO DEVELOP WEDNESDAY THROUGH FRIDAY. THIS WILL HELP KEEP LAKESHORE AREAS COOLER. I DON`T SEE ANY FEATURES OF INTEREST THAT WOULD BRING A THREAT FOR SHOWERS/STORMS DURING THE WEDNESDAY THROUGH SATURDAY TIME FRAME. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 130 PM EDT SAT JUN 9 2012 PRIMARY CHANGE TO THE TAFS THIS AFTERNOON WAS TO BUMP UP WIND SPEEDS A BIT (MOST SITES GUSTING TO 20-25 KTS) AND ALSO TO ALTER THE WIND DIRECTION A BIT FOR AZO AND BTL. WE NOTICED A MESOSCALE RIDGE DEVELOPING ACROSS THE SW PORTION OF THE STATE GIVEN THE MORE WNW COMPONENT TO THE WINDS AT AZO AND BTL VS. SSW OVER THE LAKE (THIS IS ALSO SHOWN NICELY BY THE HRRR MODEL). THIS RIDGE WILL ACT TO KEEP WINDS DIVERGENT ALONG THE COAST AND THEREFORE A CHANGE WAS MADE TO THE DIRECTIONAL COMPONENTS TO THOSE TAFS (ADJUSTED UP BY 40-50 DEGREES). ASIDE FROM THE BREEZY CONDITIONS THIS AFTERNOON THERE IS LITTLE TO MENTION IN THE TAFS THROUGH 18Z SUNDAY. && .MARINE... ISSUED AT 319 PM EDT SAT JUN 9 2012 WINDS ARE APPROACHING SMALL CRAFT ADVISORY CRITERIA NORTH OF PENTWATER...HOWEVER WE BELIEVE THAT THE WINDS SHOULD NOT INCREASE ANYMORE THIS AFTERNOON/EVENING. THE WAVES AT THE BUOY OFFSHORE OF KLDM ARE HOLDING AROUND 3 FEET ALSO. WE WILL HOLD OFF ON A SMALL CRAFT ADVISORY FOR NOW...AND CONTINUE TO MONITOR THROUGH MONDAY. STABLE CONDITIONS OVER THE LAKE WILL CONTINUE TO LIMIT THE WINDS AND WAVES COMPARED TO LAND AREAS. WINDS SHOULD REMAIN UP AROUND 10 TO 20 KNOTS THROUGH THAT PERIOD...WITH THE HIGHEST WINDS EXPECTED NORTH. HAZE IS STILL VERY POSSIBLE BEGINNING ON SUNDAY...AND ESPECIALLY ON MONDAY WITH THE HIGHER DEW POINTS MOVING IN. && .HYDROLOGY... ISSUED AT 319 PM EDT SAT JUN 9 2012 THE MAIN PERIOD OF CONCERN FOR HYDROLOGY INTERESTS WILL BE THE LATE MONDAY THROUGH TUESDAY TIME PERIOD. PRECIPITABLE WATER WILL INCREASE TO AROUND 1.75 INCHES ACROSS THE AREA MONDAY AFTERNOON. THIS RICH MOISTURE WILL ALLOW FOR LOCALLY HEAVY DOWNPOURS TO BECOME LIKELY DURING THAT PERIOD. WIDESPREAD FLOODING IS NOT EXPECTED AS THE WAVE ON MONDAY AND THE FRONT MONDAY NIGHT ARE EACH EXPECTED TO BE PROGRESSIVE IN NATURE. BASIN QPF AVERAGES ACROSS THE AREA SHOULD BE GENERALLY UP TO 0.75 INCHES...WITH LOCALLY HIGHER AMOUNTS POSSIBLE. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ SYNOPSIS...NJJ SHORT TERM...NJJ LONG TERM...HOVING AVIATION...HOVING HYDROLOGY...NJJ MARINE...NJJ
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
134 PM EDT SAT JUN 9 2012 .SYNOPSIS... ISSUED AT 330 AM EDT SAT JUN 9 2012 IT WILL BY PARTLY CLOUDY AND VERY WARM TODAY WITH HIGH TEMPERATURES REACHING THE MID TO UPPER 80S EXCEPT A LITTLE COOLER RIGHT ALONG THE LAKE MICHIGAN SHORELINE. HOT AND HUMID CONDITIONS ARE EXPECTED SUNDAY AND MONDAY WITH HIGHS AROUND 90 EXPECTED. A THREAT OF SHOWERS AND STORMS WILL COME MONDAY THROUGH MONDAY NIGHT AS A COLD FRONT MOVES THROUGH THE AREA MONDAY NIGHT. && .SHORT TERM...(TODAY THROUGH MONDAY AFTERNOON) ISSUED AT 330 AM EDT SAT JUN 9 2012 PRIMARY SHORT TERM FCST CONCERNS INVOLVE DETERMINING JUST HOW WARM IT WILL BECOME PARTICULARLY SUNDAY/MONDAY AND ALSO TO ASSESS PROBABILITIES FOR SHOWERS/TSTORMS MONDAY. MAX TEMPS TODAY WILL ALREADY REACH WELL INTO THE 80S (EXCEPT A BIT COOLER RIGHT ALONG THE LAKE MI SHORELINE) WITH INCREASING SW FLOW WAA AND AS THE UPPER RIDGE BEGINS TO AMPLIFY OVER OUR REGION. SHOWERS/TSTORMS TIED TO THE WARM FRONT SHOULD STAY NORTH OF OUR AREA AS SUGGESTED BY 00Z 4KM WRF-NMM SIM Z GUIDANCE. IT IS NOT IMPOSSIBLE THAT A STRAY LIGHT SHOWER OR SPRINKLE MAY JUST CLIP AREAS NORTH OF A LINE FROM PENTWATER TO MOP THIS MORNING BUT POTENTIAL FOR THIS IS VERY LOW SO WE WENT WITH A DRY FCST. MAX TEMPS SUNDAY SHOULD REACH THE UPPER 80S TO LOWER 90S WITH MOSTLY SUNNY SKIES AS THE UPPER RIDGE CONTINUES TO AMPLIFY OVER THE EASTERN GREAT LAKES REGION. GFS/MAV GUIDANCE IS SHOWING A TYPICAL COOL BIAS AND WE ARE GOING SEVERAL DEGREES WARMER THAN THE MAV THROUGH THE WEEKEND. HUMIDITY WILL RAMP UP SUNDAY NIGHT AND ESPECIALLY MONDAY AS DEW PTS RISE INTO THE 60S. THE THREAT FOR SHOWERS AND STORMS STARTS TO RAMP UP MONDAY AFTERNOON WITH THE APPROACHING COLD FRONT AND INCREASING INSTABILITY AS SB CAPES POTENTIALLY REACH 1000-2000 J/KG BY MONDAY AFTN. CANNOT RULE OUT A FEW STRONG STORMS BY LATE MON AFTN ESPECIALLY OVER OUR NW FCST AREA WHEN INSTABILITY WILL PEAK ALONG WITH FORCING FROM THE APPROACHING FRONT AND 0-6KM BULK SHEAR RAMPING UP TO AROUND 35 KTS OVER OUR NW COUNTIES BY LATE AFTN. HOWEVER THE OVERALL SVR WX THREAT MON AFTN LOOKS LOW DUE TO LACK OF STRONGER INSTABILITY/SHEAR AND THE COLD LAKE WATERS WHICH THE CONVECTION WILL HAVE TO TRAVERSE. .LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT 330 AM EDT SAT JUN 9 2012 NO SIGNIFICANT CHANGES TO THE GOING FORECAST. MAIN FORECAST ISSUE IS THE TIMING OF THE RAIN ALONG THE COLD FRONT EARLY NEXT WEEK. FOR MONDAY NIGHT...STILL SOME TIMING DIFFERENCES IN THE 00Z MODEL GUIDANCE FOR SHOWERS AND THUNDERSTORMS ALONG THE COLD FRONT. THE NAM IS ABOUT 6 HOURS QUICKER THAN THE GFS 12 HOURS FASTER THAN THE EURO. KEPT THE CHANCE POPS GOING BUT THESE MAY NEED TO BE UPGRADED TO LIKELY IF THE GFS AND EURO MAINTAIN CONTINUITY. EXPECT THERE TO BE ENOUGH INSTABILITY AND SHEAR FOR SOME STRONGER STORMS...MOSTLY ACROSS THE NORTHWEST FORECAST AREA. SOME LINGERING SHOWERS EXPECTED ACROSS THE EASTERN FORECAST AREA TUESDAY MORNING...BUT THERE IS GOOD MODEL AGREEMENT THAT THE FRONT WILL BE CLEARING THE FORECAST AREA BY TUESDAY AFTERNOON SO DROPPED POPS FOR THE AFTERNOON. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 130 PM EDT SAT JUN 9 2012 PRIMARY CHANGE TO THE TAFS THIS AFTERNOON WAS TO BUMP UP WIND SPEEDS A BIT (MOST SITES GUSTING TO 20-25 KTS) AND ALSO TO ALTER THE WIND DIRECTION A BIT FOR AZO AND BTL. WE NOTICED A MESOSCALE RIDGE DEVELOPING ACROSS THE SW PORTION OF THE STATE GIVEN THE MORE WNW COMPONENT TO THE WINDS AT AZO AND BTL VS. SSW OVER THE LAKE (THIS IS ALSO SHOWN NICELY BY THE HRRR MODEL). THIS RIDGE WILL ACT TO KEEP WINDS DIVERGENT ALONG THE COAST AND THEREFORE A CHANGE WAS MADE TO THE DIRECTIONAL COMPONENTS TO THOSE TAFS (ADJUSTED UP BY 40-50 DEGREES). ASIDE FROM THE BREEZY CONDITIONS THIS AFTERNOON THERE IS LITTLE TO MENTION IN THE TAFS THROUGH 18Z SUNDAY. && .MARINE... ISSUED AT 330 AM EDT SAT JUN 9 2012 WE CONTINUE TO MONITOR THE POTENTIAL FOR A SMALL CRAFT ADVISORY TODAY THROUGH SUNDAY NIGHT. WSW WINDS SHOULD INCREASE TO AROUND 15 TO 20 KTS THIS AFTN BUT STAY JUST BELOW SCA CRITERIA. THIS WILL CAUSE HIGHEST WAVE HEIGHTS NORTH OF KMKG WHERE 2 TO 4 FOOTERS ARE ANTICIPATED TODAY WITH SLIGHTLY LOWER WAVES OF AROUND 1 TO 3 FEET SOUTH OF MKG. WARM AIR MOVING OVER COOL WATERS OF LAKE MICHIGAN SHOULD KEEP WAVES FROM GETTING ANY HIGHER. FOG/HAZE WILL BECOME POSSIBLE TONIGHT AND SUNDAY AS HIGHER MOISTURE MOVES IN. && .HYDROLOGY... ISSUED AT 330 AM EDT SAT JUN 9 2012 NO HYDROLOGY ISSUES THIS WEEKEND WITH DRY WX. THE NEXT GOOD CHC OF RAIN WILL NOT COME UNTIL MONDAY NIGHT WITH A COLD FRONT. THE SHOWERS AND STORMS MON NIGHT COULD PRODUCE HEAVY DOWNPOURS WITH PRECIPITABLE WATERS INCREASING TO AROUND 2 INCHES. HOWEVER GIVEN THE PROGRESSIVE NATURE OF THE FRONT NO WIDESPREAD FLOODING ISSUES ARE EXPECTED WITH DRY WX RETURNING MID TO LATE NEXT WEEK. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ SYNOPSIS...LAURENS SHORT TERM...LAURENS LONG TERM...OSTUNO AVIATION...HOVING HYDROLOGY...LAURENS MARINE...LAURENS
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1054 PM CDT SUN JUN 10 2012 .UPDATE... ISSUED AT 1037 PM CDT SUN JUN 10 2012 ISSUED AT 651 PM CDT SUN JUN 10 2012 MADE SOME MINOR CHANGES TO THE POPS FORECAST FOR EAST CENTRAL MISSOURI CONCERNING THE TIMING OF THE CHANCE FOR POPS. SLIGHTLY DELAYED TO POPS ARRIVAL OVER EAST CENTRAL MISSOOURI. STRONG CAP CONTINUES OVER CENTRAL THROUGH SOUTHEAST AND EAST CENTRAL KANSAS AT THIS TIME. STILL BELIEVE THAT THE LOCAL LSX WRF AND HRRR IN SOME FORM HAS THE BEST SOLUTIONS COMPARED TO THE NSSL-NCEP WRF MODEL. HRRR APPEARS TO BE TO SHOW VERY STRONG REFELCTVITY ORGANIZATION WHICH MIGHT BE SUSPECT GIVEN THE EVENING ENVIRONMENT. LIKE THE LOCAL WRF THE BEST. STILL BELIEVE MUCH OF THE PRECIPITATION WILL REMAIN GENERALLY ALONG AND NORTH OF I-70. AS CONVECTION GENERALLY MOVES ACROSS THE NORTHERN HALF OF MISSOURI IT WILL HAVE SOME PROBLEMS MAINTAIN LINE STRUCTURE DUE TO WEAK VERTICAL SHEAR. ALSO WOULD LIKE TO SEE HIGHER CAPE VALUES FOR THIS TIME OF THE YEAR FOR A DYNAMIC SYSTEM TO EVOLVE. COMPARING CURRENT CASE TO PREVIOUS LINE CASES THIS EVENING. LINE-TO WEAK BROAD BOWING REFLECTIVITY STRUCTURE WILL FURTHER WEAKEN AS CONVECTIVE SYSTEM MOVES INTO EXTREME NORTHEAST MISSOURI AND EAST CENTRAL SECTIONS OF THE STATE BY 11 TO 13 UTC. PRZYBYLINSKI .SHORT TERM... ISSUED AT 325 PM CDT SUN JUN 10 2012 (TONIGHT) ISO-SCT SHRA/TSRA MAY CLIP THE SERN CWA LATE THIS AFTN BUT THE BULK OF ANY PCPN SHOULD REMAIN CLOSER TO THE MID-LEVEL LOW OVER AR/LA/MS AS IT LIFTS INTO THE TN VALLEY. ADDITIONAL SCT TSRA ARE EXPECTED TO DEVELOP LATE TONIGHT ALONG A TRAILING COLD FRONT AS IT SINKS SEWD FROM THE PLAINS TOWARDS THE CWA. PCPN MAY NOT BE VERY WIDESPREAD GIVEN THE LIMITED DYNAMICS AND LACK OF UPPER LEVEL SUPPORT. KANOFSKY && .SHORT TERM... ISSUED AT 325 PM CDT SUN JUN 10 2012 (TONIGHT) ISO-SCT SHRA/TSRA MAY CLIP THE SERN CWA LATE THIS AFTN BUT THE BULK OF ANY PCPN SHOULD REMAIN CLOSER TO THE MID-LEVEL LOW OVER AR/LA/MS AS IT LIFTS INTO THE TN VALLEY. ADDITIONAL SCT TSRA ARE EXPECTED TO DEVELOP LATE TONIGHT ALONG A TRAILING COLD FRONT AS IT SINKS SEWD FROM THE PLAINS TOWARDS THE CWA. PCPN MAY NOT BE VERY WIDESPREAD GIVEN THE LIMITED DYNAMICS AND LACK OF UPPER LEVEL SUPPORT. KANOFSKY && .LONG TERM... ISSUED AT 325 PM CDT SUN JUN 10 2012 (MONDAY THROUGH NEXT SUNDAY) UPPER LEVEL RIDGE WILL GET SUPPRESSED BY MONDAY AS A STRONG SHORTWAVE PASSES TO OUR N...AND WILL RESULT IN ZONAL FLOW UNTIL THURSDAY. AT THE SFC...A CDFNT WILL PUSH THRU MAINLY ON MONDAY AFTERNOON AND EVENING WITH HI PRES THEN DOMINATING THE REGION TUESDAY THRU WEDNESDAY NIGHT. MONDAY STILL LOOKS OUR BEST CHC FOR PCPN OVER THE NEXT WEEK... AND EVEN THEN...IT ISN/T AS MUCH OF A SLAM DUNK AS ONE WOULD THINK. WHILE THE MOISTURE AHEAD OF THE FRONT SHOULD BE DECENTLY RICH WITH SFC DWPTS PUSHING 70F...H850 DWPTS BETWEEN 13-16C...AND PWATS AROUND 1.75" WHICH IS NEAR THE 99TH PERCENTILE FOR CLIMO AND THIS SHOULD RESULT IN A VERY UNSTABLE ATMOSPHERE...LIFTING MECHANISMS DO NOT LOOK AS GOOD AND SCENARIOS TO BRING THIS ABOUT DEPICTED BY MODELS DO NOT INSPIRE CONFIDENCE. FIRST...SYNOPTIC SETUP OF CD FROPA WILL FEATURE /LAND-BETWEEN-THE-LOWS/ WHICH WILL FEATURE WEAK LO LEVEL CONVERGENCE WITH A RAPID PUNCH OF RIDGING IMMEDIATELY BEHIND. UPPER LEVEL SUPPORT LOOKS WEAK IF MODEL SIGNALS ARE CORRECT...AND IF INCORRECT WOULD MEAN JUST MODEL NOISE. IN ADDITION...A COUPLE EXPICIT 4KM WRF MODELS (BOTH NMM AND ARW) ARE SHOWING CDFNT AND DRY LINE LIGHTING UP TONIGHT...WITH THE SRN PART REMAINING THE MOST ACTIVE AND DIVING THRU SWRN MO...PUSHING AN EFFECTIVE BOUNDARY THRU MUCH OF THE FA BEFORE THINGS FIRE UP AGAIN IN THE FAR ERN FA MONDAY AFTERNOON. WHILE IT IS HARD TO BUY FULLY INTO THE EXPLICIT MODELS...THE MESSAGE IS THAT OF NOT HI CONFIDENCE IN RAIN CHCS AS WELL AS KEEPING IN MIND THE ONGOING MILD-MODERATE DROUGHT IN THE AREA. HAVE ONCE AGAIN CAPPED POPS AT 50PCT AREAWIDE AND JUST DIFFERENTIATED IN ROUGH TIMING OF BEST CHCS. CONVECTIVE DEBRIS CLOUDS AND PCPN CHCS SHOULD KEEP TEMPS IN CHECK ON MONDAY...BUT OVERALL PREFERRED THE HIGHER MET MOS NUMBERS. SHOULD SEE DRY WX TUESDAY THRU WEDNESDAY NIGHT ALTHOUGH ORDINARILY ZONAL FLOW IN JUNE WOULD GIVE ONE CAUSE FOR PAUSE. LO PWATS AND HI PRES IN CONTROL SHOULD ENSURE THAT...ALTHOUGH THE VACATING SFC HI ON WEDNESDAY NIGHT MAY LET SOMETHING SLIP THRU WITH BRIEF WINDOW OF OPPORTUNITY BETWEEN THAT AND RETURN OF UPPER RIDGE...WILL KEEP A CLOSE EYE ON THAT. THE UPPER LEVEL RIDGE WILL THEN RETURN IN FORCE THURSDAY THRU NEXT SUNDAY BRINGING WITH IT A RETURN OF THE HEAT OF COURSE. HAVE MAX TEMPS AROUND 90F GOING EACH DAY FROM FRIDAY ON...BUT WOULD NOT BE SURPRISED TO SEE FRIDAY AND SATURDAY 3-4F WARMER. THERE ARE VERY WEAK SIGNALS FOR RAIN CHCS FOR MUCH OF THIS PERIOD BUT OVERALL SYNOPTIC PATTERN SHOULD KEEP ANY CONVECTION OF A PULSE NATURE FROM WEAK SHEAR ENVIRONMENT AND LIMITED TO AFTERNOON HOURS...AND GENERALLY ISOLATED IN COVERAGE. PROBABILITIES ARE LO ENOUGH TO LIMIT TO 20PCT OR LESS...AND THUS SILENT ON THE FCST. MODELS ATTEMPT TO BREAK RIDGE DOWN A BIT ON SUNDAY...BUT BY DIFFERENT MEANS...BUT RESULT MAY BE THE SAME. HAVE EDGED BACK 30PCT CHC FROM SATURDAY TO SUNDAY BUT THIS IS EVEN SCALED BACK FROM WHAT MODELS ARE SHOWING AS SOMETHING DOESN/T QUITE LOOK RIGHT ABOUT IT. TES && .AVIATION... ISSUED AT 649 PM CDT SUN JUN 10 2012 A COLD FRONT IS PUSHING THROUGH SOUTHEAST NEBRASKA THIS EVENING CAUSING THUNDERSTORMS TO FORM. THERE ARE SOME INDICATIONS IN MODEL GUIDANCE THAT SCATTERED TO NUMEROUS STORMS WILL MOVE INTO PARTS OF CENTRAL AND NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS BETWEEN 08-12Z MONDAY MORNING...THO AM UNSURE OF HOW ORGANIZED THEY WILL BE. ALSO...SOME OF THE MODEL GUIDANCE IS HINTING THAT A LOW MVFR DECK WILL DEVELOP LATE TONIGHT DUE TO CONTINUING MOIST SOUTHERLY FLOW. WHILE THIS IS POSSIBLE...I THINK THE MODELS ARE A LITTLE OVER ZEALOUS WITH THE DEVELOPMENT OF LOW CLOUDS AND THERE ARE AT LEAST AS MANY SOLUTIONS WHICH INDICATE VFR CONDITIONS ALL NIGHT AS THERE ARE SHOWING LOWER CIGS. THE FRONT WILL PROGRESS SLOWLY SOUTHEAST ON MONDAY. THINK WIDELY SCATTERED-SCATTERED STORMS WILL BE POSSIBLE FOR MUCH OF THE DAY...CLEARING FROM WEST TO EAST IN THE AFTERNOON. SPECIFICS FOR KSTL... VFR FLIGHT CONDITIONS ARE EXPECTED TO PREVAIL AT LAMBERT. THINK ANY THUNDERSTORMS THAT COULD AFFECT LAMBERT WON`T BE NEAR THE TERMINAL UNTIL AT LEAST 12Z. SOME OF THE MODEL GUIDANCE IS HINTING THAT A LOW MVFR DECK WILL DEVELOP LATE TONIGHT DUE TO CONTINUING MOIST SOUTHERLY FLOW. WHILE THIS IS POSSIBLE...I THINK THE MODELS ARE A LITTLE OVER ZEALOUS WITH THE DEVELOPMENT OF LOW CLOUDS AND THERE ARE AT LEAST AS MANY SOLUTIONS WHICH INDICATE VFR CONDITIONS ALL NIGHT AS THERE ARE SHOWING LOWER CIGS. THE COLD FRONT OVER SOUTHEAST NEBRASKA WILL PROGRESS SLOWLY SOUTHEAST ON MONDAY. THINK WIDELY SCATTERED-SCATTERED STORMS WILL BE POSSIBLE FOR MUCH OF THE DAY...CLEARING FROM WEST TO EAST IN THE AFTERNOON. CARNEY && .LSX WATCHES/WARNINGS/ADVISORIES... MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
706 PM CDT SUN JUN 10 2012 .UPDATE... ISSUED AT 651 PM CDT SUN JUN 10 2012 NOT MUCH CHANGE IN THE GOING FORECASTS. ISOLATED SHOWERS OVER FAR SOUTHERN PART OF CWA WEAKENED BETWEEN 2230 AND 2300 UTC. ADJUSTED TEMPERATURES A LITTLE BIT. OTHERWISE NOT MUCH IN THE WAY OF CHANGES TO THE GOING FORECAST. SOUNDING FROM TOP SHOWS VERY STRONG CAP OVER NORTHEAST KANSAS. WEAK ISOLATED CELLS TRYING TO DEVELOP BUT HAVING A HARD TIME. CAPE VALUES ARE RESPECTABLE BUT CAP REMAINS STRONG. WATER VAPOR IMAGERY IS SHOWING IMPLUSE RACING ACROSS THE NORTHERN PLAINS AT THIS TIME WITH THE GREATEST FORCING OVER THE UPPER MISSISSIPPI RIVER VALLEY REGION. NCEP AND NSSL WRF SHOWS MCS DEVELOPING OVER EAST CENTRAL KANSAS AND MOVES IT SOUTHEASTWARD. LOCAL LSX WRF MODEL SHOWS MAIN CONVECTIVE LINE OVER NORTHWEST MISSOURI AND WEAKENES IT WITH TIME AS IT MOVES ACROSS THE NORTHERN HALF OF MISSOURI. THE HRRR SHOWS THE SAME TREND BUT MAGNIFIES IT 2X TO 3X. LIKE THE LOCAL WRF MODEL AT THIS TIME. JUST A POINT OF INTEREST ON THE WATER VAPOR THE SUBTROPIC BRANCH IS BRING MOISTURE NORTHEASTWARD ACROSS BAJA. WILL BE INTERESTING TO WATCH THIS FEATURE DURING THE NEXT FEW DAYS. PRZYBYLINSKI .SHORT TERM... ISSUED AT 325 PM CDT SUN JUN 10 2012 (TONIGHT) ISO-SCT SHRA/TSRA MAY CLIP THE SERN CWA LATE THIS AFTN BUT THE BULK OF ANY PCPN SHOULD REMAIN CLOSER TO THE MID-LEVEL LOW OVER AR/LA/MS AS IT LIFTS INTO THE TN VALLEY. ADDITIONAL SCT TSRA ARE EXPECTED TO DEVELOP LATE TONIGHT ALONG A TRAILING COLD FRONT AS IT SINKS SEWD FROM THE PLAINS TOWARDS THE CWA. PCPN MAY NOT BE VERY WIDESPREAD GIVEN THE LIMITED DYNAMICS AND LACK OF UPPER LEVEL SUPPORT. KANOFSKY && .LONG TERM... ISSUED AT 325 PM CDT SUN JUN 10 2012 (MONDAY THROUGH NEXT SUNDAY) UPPER LEVEL RIDGE WILL GET SUPPRESSED BY MONDAY AS A STRONG SHORTWAVE PASSES TO OUR N...AND WILL RESULT IN ZONAL FLOW UNTIL THURSDAY. AT THE SFC...A CDFNT WILL PUSH THRU MAINLY ON MONDAY AFTERNOON AND EVENING WITH HI PRES THEN DOMINATING THE REGION TUESDAY THRU WEDNESDAY NIGHT. MONDAY STILL LOOKS OUR BEST CHC FOR PCPN OVER THE NEXT WEEK... AND EVEN THEN...IT ISN/T AS MUCH OF A SLAM DUNK AS ONE WOULD THINK. WHILE THE MOISTURE AHEAD OF THE FRONT SHOULD BE DECENTLY RICH WITH SFC DWPTS PUSHING 70F...H850 DWPTS BETWEEN 13-16C...AND PWATS AROUND 1.75" WHICH IS NEAR THE 99TH PERCENTILE FOR CLIMO AND THIS SHOULD RESULT IN A VERY UNSTABLE ATMOSPHERE...LIFTING MECHANISMS DO NOT LOOK AS GOOD AND SCENARIOS TO BRING THIS ABOUT DEPICTED BY MODELS DO NOT INSPIRE CONFIDENCE. FIRST...SYNOPTIC SETUP OF CD FROPA WILL FEATURE /LAND-BETWEEN-THE-LOWS/ WHICH WILL FEATURE WEAK LO LEVEL CONVERGENCE WITH A RAPID PUNCH OF RIDGING IMMEDIATELY BEHIND. UPPER LEVEL SUPPORT LOOKS WEAK IF MODEL SIGNALS ARE CORRECT...AND IF INCORRECT WOULD MEAN JUST MODEL NOISE. IN ADDITION...A COUPLE EXPICIT 4KM WRF MODELS (BOTH NMM AND ARW) ARE SHOWING CDFNT AND DRY LINE LIGHTING UP TONIGHT...WITH THE SRN PART REMAINING THE MOST ACTIVE AND DIVING THRU SWRN MO...PUSHING AN EFFECTIVE BOUNDARY THRU MUCH OF THE FA BEFORE THINGS FIRE UP AGAIN IN THE FAR ERN FA MONDAY AFTERNOON. WHILE IT IS HARD TO BUY FULLY INTO THE EXPLICIT MODELS...THE MESSAGE IS THAT OF NOT HI CONFIDENCE IN RAIN CHCS AS WELL AS KEEPING IN MIND THE ONGOING MILD-MODERATE DROUGHT IN THE AREA. HAVE ONCE AGAIN CAPPED POPS AT 50PCT AREAWIDE AND JUST DIFFERENTIATED IN ROUGH TIMING OF BEST CHCS. CONVECTIVE DEBRIS CLOUDS AND PCPN CHCS SHOULD KEEP TEMPS IN CHECK ON MONDAY...BUT OVERALL PREFERRED THE HIGHER MET MOS NUMBERS. SHOULD SEE DRY WX TUESDAY THRU WEDNESDAY NIGHT ALTHOUGH ORDINARILY ZONAL FLOW IN JUNE WOULD GIVE ONE CAUSE FOR PAUSE. LO PWATS AND HI PRES IN CONTROL SHOULD ENSURE THAT...ALTHOUGH THE VACATING SFC HI ON WEDNESDAY NIGHT MAY LET SOMETHING SLIP THRU WITH BRIEF WINDOW OF OPPORTUNITY BETWEEN THAT AND RETURN OF UPPER RIDGE...WILL KEEP A CLOSE EYE ON THAT. THE UPPER LEVEL RIDGE WILL THEN RETURN IN FORCE THURSDAY THRU NEXT SUNDAY BRINGING WITH IT A RETURN OF THE HEAT OF COURSE. HAVE MAX TEMPS AROUND 90F GOING EACH DAY FROM FRIDAY ON...BUT WOULD NOT BE SURPRISED TO SEE FRIDAY AND SATURDAY 3-4F WARMER. THERE ARE VERY WEAK SIGNALS FOR RAIN CHCS FOR MUCH OF THIS PERIOD BUT OVERALL SYNOPTIC PATTERN SHOULD KEEP ANY CONVECTION OF A PULSE NATURE FROM WEAK SHEAR ENVIRONMENT AND LIMITED TO AFTERNOON HOURS...AND GENERALLY ISOLATED IN COVERAGE. PROBABILITIES ARE LO ENOUGH TO LIMIT TO 20PCT OR LESS...AND THUS SILENT ON THE FCST. MODELS ATTEMPT TO BREAK RIDGE DOWN A BIT ON SUNDAY...BUT BY DIFFERENT MEANS...BUT RESULT MAY BE THE SAME. HAVE EDGED BACK 30PCT CHC FROM SATURDAY TO SUNDAY BUT THIS IS EVEN SCALED BACK FROM WHAT MODELS ARE SHOWING AS SOMETHING DOESN/T QUITE LOOK RIGHT ABOUT IT. TES && .AVIATION... ISSUED AT 649 PM CDT SUN JUN 10 2012 A COLD FRONT IS PUSHING THROUGH SOUTHEAST NEBRASKA THIS EVENING CAUSING THUNDERSTORMS TO FORM. THERE ARE SOME INDICATIONS IN MODEL GUIDANCE THAT SCATTERED TO NUMEROUS STORMS WILL MOVE INTO PARTS OF CENTRAL AND NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS BETWEEN 08-12Z MONDAY MORNING...THO AM UNSURE OF HOW ORGANIZED THEY WILL BE. ALSO...SOME OF THE MODEL GUIDANCE IS HINTING THAT A LOW MVFR DECK WILL DEVELOP LATE TONIGHT DUE TO CONTINUING MOIST SOUTHERLY FLOW. WHILE THIS IS POSSIBLE...I THINK THE MODELS ARE A LITTLE OVER ZEALOUS WITH THE DEVELOPMENT OF LOW CLOUDS AND THERE ARE AT LEAST AS MANY SOLUTIONS WHICH INDICATE VFR CONDITIONS ALL NIGHT AS THERE ARE SHOWING LOWER CIGS. THE FRONT WILL PROGRESS SLOWLY SOUTHEAST ON MONDAY. THINK WIDELY SCATTERED-SCATTERED STORMS WILL BE POSSIBLE FOR MUCH OF THE DAY...CLEARING FROM WEST TO EAST IN THE AFTERNOON. SPECIFICS FOR KSTL... VFR FLIGHT CONDITIONS ARE EXPECTED TO PREVAIL AT LAMBERT. THINK ANY THUNDERSTORMS THAT COULD AFFECT LAMBERT WON`T BE NEAR THE TERMINAL UNTIL AT LEAST 12Z. SOME OF THE MODEL GUIDANCE IS HINTING THAT A LOW MVFR DECK WILL DEVELOP LATE TONIGHT DUE TO CONTINUING MOIST SOUTHERLY FLOW. WHILE THIS IS POSSIBLE...I THINK THE MODELS ARE A LITTLE OVER ZEALOUS WITH THE DEVELOPMENT OF LOW CLOUDS AND THERE ARE AT LEAST AS MANY SOLUTIONS WHICH INDICATE VFR CONDITIONS ALL NIGHT AS THERE ARE SHOWING LOWER CIGS. THE COLD FRONT OVER SOUTHEAST NEBRASKA WILL PROGRESS SLOWLY SOUTHEAST ON MONDAY. THINK WIDELY SCATTERED-SCATTERED STORMS WILL BE POSSIBLE FOR MUCH OF THE DAY...CLEARING FROM WEST TO EAST IN THE AFTERNOON. CARNEY && .LSX WATCHES/WARNINGS/ADVISORIES... MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
703 PM CDT SUN JUN 10 2012 .UPDATE... ISSUED AT 651 PM CDT SUN JUN 10 2012 NOT MUCH CHANGE IN THE GOING FORECASTS. ISOLATED SHOWERS OVER FAR SOUTHERN PART OF CWA WEAKENED BETWEEN 2230 AND 2300 UTC. ADJUSTED TEMPERATURES A LITTLE BIT. OTHERWISE NOT MUCH IN THE WAY OF CHANGES TO THE GOING FORECAST. SOUNDING FROM TOP SHOWS VERY STRONG CAP OVER NORTHEAST KANSAS. WEAK ISOLATED CELLS TRYING TO DEVELOP BUT HAVING A HARD TIME. CAPE VALUES ARE RESPECTABLE BUT CAP REMAINS STRONG. WATER VAPOR IMAGERY IS SHOWING IMPLUSE RACING ACROSS THE NORTHERN PLAINS AT THIS TIME WITH THE GREATEST FORCING OVER THE UPPER MISSISSIPPI RIVER VALLEY REGION. NCEP AND NSSL WRF SHOWS MCS DEVELOPING OVER EAST CENTRAL KANSAS AND MOVES IT SOUTHEASTWARD. LOCAL LSX WRF MODEL SHOWS MAIN CONVECTIVE LINE OVER NORTHWEST MISSOURI AND WEAKENES IT WITH TIME AS IT MOVES ACROSS THE NORTHERN HALF OF MISSOURI. THE HRRR SHOWS THE SAME TREND BUT MAGNIFIES IT 2X TO 3X. LIKE THE LOCAL WRF MODEL AT THIS TIME. JUST A POINT OF INTEREST ON THE WATER VAPOR THE SUBTROPIC BRANCH IS BRING MOISTURE NORTHEASTWARD ACROSS BAJA. WILL BE INTERESTING TO WATCH THIS FEATURE DURING THE NEXT FEW DAYS. PRZYBYLINSKI && .SHORT TERM... ISSUED AT 325 PM CDT SUN JUN 10 2012 (TONIGHT) ISO-SCT SHRA/TSRA MAY CLIP THE SERN CWA LATE THIS AFTN BUT THE BULK OF ANY PCPN SHOULD REMAIN CLOSER TO THE MID-LEVEL LOW OVER AR/LA/MS AS IT LIFTS INTO THE TN VALLEY. ADDITIONAL SCT TSRA ARE EXPECTED TO DEVELOP LATE TONIGHT ALONG A TRAILING COLD FRONT AS IT SINKS SEWD FROM THE PLAINS TOWARDS THE CWA. PCPN MAY NOT BE VERY WIDESPREAD GIVEN THE LIMITED DYNAMICS AND LACK OF UPPER LEVEL SUPPORT. KANOFSKY && .LONG TERM... ISSUED AT 325 PM CDT SUN JUN 10 2012 (MONDAY THROUGH NEXT SUNDAY) UPPER LEVEL RIDGE WILL GET SUPPRESSED BY MONDAY AS A STRONG SHORTWAVE PASSES TO OUR N...AND WILL RESULT IN ZONAL FLOW UNTIL THURSDAY. AT THE SFC...A CDFNT WILL PUSH THRU MAINLY ON MONDAY AFTERNOON AND EVENING WITH HI PRES THEN DOMINATING THE REGION TUESDAY THRU WEDNESDAY NIGHT. MONDAY STILL LOOKS OUR BEST CHC FOR PCPN OVER THE NEXT WEEK... AND EVEN THEN...IT ISN/T AS MUCH OF A SLAM DUNK AS ONE WOULD THINK. WHILE THE MOISTURE AHEAD OF THE FRONT SHOULD BE DECENTLY RICH WITH SFC DWPTS PUSHING 70F...H850 DWPTS BETWEEN 13-16C...AND PWATS AROUND 1.75" WHICH IS NEAR THE 99TH PERCENTILE FOR CLIMO AND THIS SHOULD RESULT IN A VERY UNSTABLE ATMOSPHERE...LIFTING MECHANISMS DO NOT LOOK AS GOOD AND SCENARIOS TO BRING THIS ABOUT DEPICTED BY MODELS DO NOT INSPIRE CONFIDENCE. FIRST...SYNOPTIC SETUP OF CD FROPA WILL FEATURE /LAND-BETWEEN-THE-LOWS/ WHICH WILL FEATURE WEAK LO LEVEL CONVERGENCE WITH A RAPID PUNCH OF RIDGING IMMEDIATELY BEHIND. UPPER LEVEL SUPPORT LOOKS WEAK IF MODEL SIGNALS ARE CORRECT...AND IF INCORRECT WOULD MEAN JUST MODEL NOISE. IN ADDITION...A COUPLE EXPICIT 4KM WRF MODELS (BOTH NMM AND ARW) ARE SHOWING CDFNT AND DRY LINE LIGHTING UP TONIGHT...WITH THE SRN PART REMAINING THE MOST ACTIVE AND DIVING THRU SWRN MO...PUSHING AN EFFECTIVE BOUNDARY THRU MUCH OF THE FA BEFORE THINGS FIRE UP AGAIN IN THE FAR ERN FA MONDAY AFTERNOON. WHILE IT IS HARD TO BUY FULLY INTO THE EXPLICIT MODELS...THE MESSAGE IS THAT OF NOT HI CONFIDENCE IN RAIN CHCS AS WELL AS KEEPING IN MIND THE ONGOING MILD-MODERATE DROUGHT IN THE AREA. HAVE ONCE AGAIN CAPPED POPS AT 50PCT AREAWIDE AND JUST DIFFERENTIATED IN ROUGH TIMING OF BEST CHCS. CONVECTIVE DEBRIS CLOUDS AND PCPN CHCS SHOULD KEEP TEMPS IN CHECK ON MONDAY...BUT OVERALL PREFERRED THE HIGHER MET MOS NUMBERS. SHOULD SEE DRY WX TUESDAY THRU WEDNESDAY NIGHT ALTHOUGH ORDINARILY ZONAL FLOW IN JUNE WOULD GIVE ONE CAUSE FOR PAUSE. LO PWATS AND HI PRES IN CONTROL SHOULD ENSURE THAT...ALTHOUGH THE VACATING SFC HI ON WEDNESDAY NIGHT MAY LET SOMETHING SLIP THRU WITH BRIEF WINDOW OF OPPORTUNITY BETWEEN THAT AND RETURN OF UPPER RIDGE...WILL KEEP A CLOSE EYE ON THAT. THE UPPER LEVEL RIDGE WILL THEN RETURN IN FORCE THURSDAY THRU NEXT SUNDAY BRINGING WITH IT A RETURN OF THE HEAT OF COURSE. HAVE MAX TEMPS AROUND 90F GOING EACH DAY FROM FRIDAY ON...BUT WOULD NOT BE SURPRISED TO SEE FRIDAY AND SATURDAY 3-4F WARMER. THERE ARE VERY WEAK SIGNALS FOR RAIN CHCS FOR MUCH OF THIS PERIOD BUT OVERALL SYNOPTIC PATTERN SHOULD KEEP ANY CONVECTION OF A PULSE NATURE FROM WEAK SHEAR ENVIRONMENT AND LIMITED TO AFTERNOON HOURS...AND GENERALLY ISOLATED IN COVERAGE. PROBABILITIES ARE LO ENOUGH TO LIMIT TO 20PCT OR LESS...AND THUS SILENT ON THE FCST. MODELS ATTEMPT TO BREAK RIDGE DOWN A BIT ON SUNDAY...BUT BY DIFFERENT MEANS...BUT RESULT MAY BE THE SAME. HAVE EDGED BACK 30PCT CHC FROM SATURDAY TO SUNDAY BUT THIS IS EVEN SCALED BACK FROM WHAT MODELS ARE SHOWING AS SOMETHING DOESN/T QUITE LOOK RIGHT ABOUT IT. TES && .AVIATION... ISSUED AT 1222 PM CDT SUN JUN 10 2012 ANY ISO-SCT SHRA/TSRA THAT DEVELOP THIS AFTN SHOULD REMAIN SOUTH AND EAST OF THE TERMINALS. DIURNAL CU WILL DISSIPATE AFTER SUNSET. SCT TSRA ARE EXPECTED LATE TONIGHT AND TOMORROW AS A COLD FRONT MOVES THROUGH MO/IL. VCTS GROUPS IN THE 18Z TAFS HIGHLIGHT THE BEST WINDOW FOR TSRA AT THE TERMINALS HOWEVER FURTHER REFINEMENT WILL BE NEEDED AS OVERNIGHT CONVECTIVE TRENDS BECOME ESTABLISHED. SLY WINDS TURN WLY WITH FROPA THEN BECOME NWLY JUST BEYOND THE END OF THE 24 HR TAF PD. SPECIFICS FOR KSTL...ANY ISO-SCT SHRA/TSRA THAT DEVELOP THIS AFTN SHOULD REMAIN SOUTH AND EAST OF KSTL. DIURNAL CU WILL DISSIPATE AFTER SUNSET. SCT TSRA ARE EXPECTED LATE TONIGHT AND TOMORROW AS A COLD FRONT MOVES THROUGH MO/IL. VCTS GROUP IN THE 18Z TAF FOR KSTL HIGHLIGHTS THE BEST WINDOW FOR TSRA HOWEVER FURTHER REFINEMENT WILL BE NEEDED AS OVERNIGHT CONVECTIVE TRENDS BECOME ESTABLISHED. SLY WINDS TURN WLY WITH FROPA THEN BECOME NWLY BEYOND THE END OF THE 30 HR TAF PD. KANOFSKY && .LSX WATCHES/WARNINGS/ADVISORIES... MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS GLASGOW MT
919 PM MDT SUN JUN 10 2012 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH TUESDAY... EVENING UPDATE... CHANGES FOR THIS EVENING WERE TO ACCOUNT FOR A DRY SLOT WRAPPING AROUND A LOW CENTERED ON THE INTERNATIONAL BORDER NEAR DANIELS AND SHERIDAN COUNTY. THIS DRY COOL DRIER AIR IS EVIDENT ON VISIBLE IMAGERY AND AREAL METARS MAPS AND WILL BEGIN STREAMING INTO PHILLIPS AND VALLEY COUNTY THIS EVENING AND CONTINUE INTO THE YELLOWSTONE VALLEY OF THE GGW CWA THROUGH THE MORNING HOURS. A BIT OF INSTABILITY MAY BE PRODUCED FROM THE DRIER AIR ALONG THE EDGE OF THE DRY SLOT THROUGH PETROLEUM... SOUTHERN PHILLIPS... AND GARFIELD COUNTY DURING THE EVENING AND EARLY MORNING HOURS AND COULD GENERATE SLIGHTLY MORE CONVECTIVE AND NARROW BANDS OF PRECIP IN NORTHWEST FLOW. SKY COVER AND THEREFORE TEMPERATURES OVER THE NEXT 12 HOURS WERE ALSO ADJUSTED TO MEET THIS THINKING. WINDS WERE ALSO ADJUSTED ALONG THE GGW/BYZ CWA BORDER TO ACCOUNT FOR THE DECOUPLING OF THE SURFACE LAYER. USED HRRR AND HIRES-ARM BLEND WITH SURFACE OBS TO FORMULATE THE WIND FIELD OVER THE NEXT 12 HOURS. GAH PREVIOUS SHORT TERM DISCUSSION... UPPER LOW NOW OVER NEMONT WITH PLENTY OF MOISTURE WRAPPING AROUND THE BACKSIDE OF THIS FEATURE. THIS IS CREATING WIDESPREAD WETTING RAIN ACROSS CENTRAL MONTANA...AND THE WETTING RAIN IS MOVING INTO NEMONT. THE RAIN WILL CONTINUE OVER THE CWA FOR THE REST OF THIS AFTERNOON AND EVENING BUT WILL TAPPER OFF OVERNIGHT INTO MONDAY MORNING AS UPPER LOW MOVES TO THE NORTHEAST. SO KEPT POPS HIGH AROUND 90% FOR THIS AFTERNOON AND EVENING BUT DROPPED THEM AFTER MIDNIGHT. MEANWHILE...SURFACE GRADIENT BETWEEN SURFACE LOW IN MANITOBA AND HIGH PRESSURE IN WESTERN MONTANA WILL KEEP THE PRESSURE GRADIENT TIGHT THROUGH MONDAY AFTERNOON. SO WILL KEEP THE LAKE WIND ADVISORY GOING DURING THIS TIME FRAME. WINDS WILL START TO DECREASE LATE MONDAY AFTERNOON AS SURFACE GRADIENT BEGINS TO WEAKEN. FOR MONDAY SOMEWHAT UNSTABLE NORTHWEST FLOW ALOFT WILL CONTINUE ON MONDAY WHICH WILL ALLOW A FEW SCATTERED SHOWERS TO DEVELOP. WILL KEEP THE SLIGHT CHANCE POPS IN THE FORECAST. MONDAY NIGHT AND TUESDAY...SURFACE HIGH PRESSURE BUILDS INTO EASTERN MONTANA MONDAY NIGHT DIMINISHING THE WINDS AND ALLOWING FOR DRY WEATHER. FLOW ALOFT TURNS ZONAL DURING THE DAY ON TUESDAY AND THE MODELS DO SHOW A WEAK SHORTWAVE TROUGH APPROACHING THE AREA TUESDAY AFTERNOON. WE DO HAVE SOME INSTABILITY WITH ELEVATED CAPE READING BETWEEN 300 AND 700 J/KG AND LIFTED INDICES AROUND -3. HIGHS WILL BE LITTLE WARMER ON TUESDAY WITH READING IN THE MID 70S. SO A SHOWER OR THUNDERSTORM IN THE AFTERNOON IS NOT OUT OF THE QUESTION... WILL KEEP THE MENTION OF A SLIGHT CHANCE FOR TUESDAY AFTERNOON. RSMITH .LONG TERM...TUESDAY NIGHT THROUGH SUNDAY... THE EXTENDED FORECAST IS FULL OF OPPORTUNITY FOR MORE RAIN AND COOLER THAN NORMAL TEMPERATURES AS A GENERAL UPPER LEVEL TROUGH PATTERN SETS BACK UP OVER THE REGION. INITIALLY TUESDAY EVENING THE UPPER LEVEL PATTERN IS MORE ZONAL...BUT THERE IS GOOD AGREEMENT IN A WEAK SHORTWAVE PASSING INTO ND OVER A SURFACE WARM FRONT...SO THIS WILL REQUIRE LOW POPS IN THE EAST ZONES. NEXT SHORTWAVE PASSES OVERHEAD WED AFTN/EVENING AND LOOKS A LITTLE STRONGER. MOST MODELS TAKE BULK OF ENERGY JUST TO THE NORTH...SO WE MAY BE SPARED WORSE CONDITIONS...BUT KNOW DOUBT AT LEAST SCATTERED CONVECTION SHOULD FIRE IN THE AFTN...ESPECIALLY VICINITY OF SURFACE BOUNDARY STRETCHING NW-SE ACROSS NE MT. BY FRIDAY THE STRONGEST PART OF THE DEVELOPING LONGWAVE TROUGH SHOULD BE CROSSING OR DIGGING DOWN OVER THE NRN ROCKIES. OUR REGION WILL BE UNDER THE BUSY SOUTHWESTERLY FLOW PATTERN AHEAD OF THE TROUGH AXIS. THEREAFTER MODELS START TO DIVERGE AND THE CONFIDENCE IN ANY ONE SOLUTION REALLY PLUMMETS. NCEPS GLOBABL ENSEMBLE MEASURE OF PREDICTABILITY CHARTS ALSO SHOW VERY LOW CONFIDENCE IN THE PATTERN OVER MT DURING THE WEEKEND. HOWEVER...IT SEEMS REASONABLE BASED ON THE OVERALL PATTERN TO EXPECT A HIGHER THAN CLIMATOLOGICALLY NORMAL POP FOR THIS TIME OF YEAR. SO HAVE POPS BASICALLY IN THE 30 TO 40 PERCENT RANGE FRIDAY THROUGH SUNDAY. IT SEEMS LIKELY NO MATTER WHAT SOLUTION IS CORRECT WE WILL DEAL WITH AT LEAST ONE OR TWO MESOSCALE CONVECTIVE SYSTEMS IN THE NRN PLAINS...WHICH MAY INCLUDE PARTS OF NE MONTANA ESPECIALLY TOWARD THE ND BORDER. MOYER && .AVIATION... SHOWERS SHOULD GRADUALLY BEGIN TO DECREASE AFTER 4Z AS LARGE UPPER STORM SYSTEM MOVES INTO THE DAKOTAS. SOME HEAVIER SHOWERS HAVE CAUSED TEMPORARY MVFR TO IFR CONDITIONS FROM BOTH CEILINGS DOWN TO 1000 FT AND VISIBILITY BELOW 2 MILES...BUT PREVAILING CONDITIONS HAVE BEEN VFR WITH CEILINGS DOWN TO 4000 FT AGL. SOME INSTABILITY HAS LED TO A LITTLE CB ACTIVITY IN THE SYDNEY AND GLENDIVE AREA. FOR MONDAY...PRECIPITATION WILL HAVE ENDED...BUT STRONG NORTHWESTERLY WINDS UP TO 30KTS WILL HANG ON IN THE GLENDIVE AND SYDNEY AREAS UNTIL LATE AFTERNOON. MARTIN && .GLASGOW WATCHES/WARNINGS/ADVISORIES... LAKE WIND ADVISORY UNTIL 6 PM MDT MONDAY FOR FOR FORT PECK LAKEFORT PECK LAKE. && $$ WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...CORRECTED
NWS BILLINGS MT
908 PM MDT SUN JUN 10 2012 .SHORT TERM...VALID FOR MON AND TUE... THE AXIS OF A 500-HPA TROUGH IS SITUATED ALONG THE MT/ND BORDER AT 02 UTC...AND WILL SHIFT EASTWARD OVERNIGHT WITH NORTHWEST MID- AND UPPER-LEVEL FLOW ACROSS OUR AREA. TROWAL-LIKE PRECIPITATION IN THE WAKE OF THIS FEATURE HAS BEGUN DECREASING THIS EVENING AS VERTICAL MOTION ON ISENTROPIC SURFACES DIMINISHES. THE 00 UTC NAM CONTINUES SHOWING THAT TREND...WHICH LINES UP WITH THE LAST SEVERAL HRRR AND RAP SOLUTIONS IN ADVERTISING ONLY SMALL SHOWER COVERAGE BEYOND THE 06 UTC TIME FRAME. WE MAINTAINED 20 TO 30 POPS AFTER MIDNIGHT OVER THE LOWER ELEVATIONS THOUGH GIVEN CYCLONIC FLOW ALOFT. WE DID ALSO INCREASE FORECAST WINDS OVERNIGHT IN SOUTHEASTERN MT...WITH RECENT TRENDS ACTUALLY SHOWING AN UPTICK IN SPEEDS ON PAR WITH INCREASING 500 M AGL WINDS IN THAT AREA PER THE 00 UTC NAM. THOSE WIND FIELDS SHOW SPEEDS AROUND 35 KT IN THE BAKER AND EKALAKA AREAS UNTIL NEAR 09 UTC...WHICH SHOULD BE GOOD ENOUGH FOR SUSTAINED WINDS AROUND 30 MPH EVEN WITH WEAK BOUNDARY LAYER DECOUPLING. SINCE THE LOW LEVELS WILL REMAIN AT LEAST A BIT MIXED IN MOST AREAS...TEMPERATURES WILL NOT FALL TOO QUICKLY OVERNIGHT. SCHULTZ .LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN... PLENTY OF UNCERTAINTIES INTO THE EXTENDED WITH SOME BOUNCING AROUND IN THE MEDIUM RANGE GUIDANCE BUT AN OVERALL UNSETTLED WEATHER PATTERN LOOKS LIKELY AS A SERIES OF SYSTEMS MOVE OUT OF THE PACIFIC NORTHWEST AND ACROSS THE NORTHERN ROCKIES. SPEED AND AMPLIFICATION OF THE SYSTEMS WILL BE THE BIGGEST CHALLENGE. HAVE FOLLOWED THE GFS THE CLOSEST WITH THE TRENDS AS IT HANDLED THIS LAST SYSTEM BETTER THAN EC. SOUTHWEST FLOW WILL OFFER A LOWER CHANCE OF STORMS WEDNESDAY AND THURSDAY. OPER GFS ADVERTISES AN UPPER LOW THEN TO DIG TO OUR WEST AND SOUTH FOR FRIDAY INTO SATURDAY AND COULD OFFER UP ANOTHER COOL AND UNSETTLED WEEKEND. SOME AMPLITUDE OF TROUGHINESS IS ALSO SUPPORTED BY THE GFS ENSEMBLE MEMBERS. HAVE CONTINUED WITH THE HIGHER CHANCE PRECIP CHANCES FOR FRIDAY INTO SATURDAY. NOT ABLE TO COMPLETELY BUY THIS SOLUTION THOUGH AS EC ADVERTISING LESS AMPLIFICATION AND AFTER FRIDAYS CONVECTION...THIS MODEL DRY THINGS OUT FOR SATURDAY. TEMPERATURES TRENDS LOOKED GOOD OVERALL WITH ONLY MINOR CHANGES. WARMEST DAYS WILL BE IN SOUTHWEST FLOW WEDNESDAY AND THURSDAY. FRIEDERS && .AVIATION... VFR CONDITIONS WILL GENERALLY PREVAIL OVERNIGHT WITH MID LEVEL CLOUD DECKS AND AREAS OF SHOWERS SLOWLY MIGRATING EAST BEFORE DECREASING. HOWEVER...THERE MAY BE SOME AREAS OF MVFR EAST OF KBIL TO KMLS AND BHK INTO EARLY MONDAY. STRONG WEST WINDS WILL BE PERSISTENT THROUGH THIS EVENING WITH A FEW GUSTS AROUND 40KTS AND POSSIBLY STRONGER WITHIN HEAVIER SHOWERS. BT && .PRELIMINARY POINT TEMP/POPS... MON TUE WED THU FRI SAT SUN ----------------------------------------------------------- BIL 049/073 050/077 053/080 056/081 056/076 054/074 054/073 62/W 22/T 22/T 22/T 34/T 44/T 43/T LVM 043/069 040/072 045/076 046/075 046/072 045/069 046/068 52/W 22/T 22/T 33/T 35/T 54/T 43/T HDN 046/073 050/078 051/082 055/083 056/079 054/076 054/076 92/W 22/T 22/T 22/T 34/T 44/T 43/T MLS 050/073 050/078 055/082 057/084 058/079 056/077 056/076 92/W 12/T 22/T 22/T 34/T 44/T 43/T 4BQ 047/071 048/077 052/081 056/084 057/080 055/077 055/076 62/T 22/T 32/T 21/B 33/T 34/T 43/T BHK 047/067 045/075 051/078 057/082 058/079 057/076 057/075 73/W 12/T 32/T 21/B 34/T 44/T 43/T SHR 046/071 045/073 049/078 051/080 052/076 050/073 050/073 32/W 22/T 22/T 22/T 34/T 44/T 43/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
858 PM MDT SUN JUN 10 2012 .SHORT TERM...VALID FOR MON AND TUE... THE AXIS OF A 500-HPA TROUGH IS SITUATED ALONG THE MT/ND BORDER AT 02 UTC...AND WILL SHIFT EASTWARD OVERNIGHT WITH NORTHWEST MID- AND UPPER-LEVEL FLOW ACROSS OUR AREA. TROWAL-LIKE PRECIPITATION IN THE WAKE OF THIS FEATURE HAS BEGUN DECREASING THIS EVENING AS VERTICAL MOTION ON ISENTROPIC SURFACES DIMINISHES. THE 00 UTC NAM CONTINUES SHOWING THAT TREND...WHICH ALSO LINES UP THE LAST SEVERAL HRRR AND RAP SOLUTIONS IN ADVERTISING ONLY SMALL SHOWER COVERAGE BEYOND THE 06 UTC TIME FRAME. WE MAINTAINED 20 TO 30 POPS AFTER MIDNIGHT OVER THE LOWER ELEVATIONS THOUGH GIVEN CYCLONIC FLOW ALOFT. WE DID ALSO INCREASE FORECAST WINDS OVERNIGHT IN SOUTHEASTERN MT...WITH RECENT TRENDS ACTUALLY SHOWING AN UPTICK IN SPEEDS ON PAR WITH INCREASING 500 M AGL WINDS IN THAT AREA PER THE 00 UTC NAM. THOSE WIND FIELDS SHOW SPEEDS AROUND 35 KT IN THE BAKER AND EKALAKA AREAS UNTIL NEAR 09 UTC...WHICH SHOULD BE GOOD ENOUGH FOR SUSTAINED WINDS AROUND 30 MPH EVEN WITH WEAK BOUNDARY LAYER DECOUPLING. SINCE THE LOW LEVELS WILL REMAIN AT LEAST A BIT MIXED IN MOST AREAS...TEMPERATURES WILL NOT FALL TOO QUICKLY OVERNIGHT. SCHULTZ .LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN... PLENTY OF UNCERTAINTIES INTO THE EXTENDED WITH SOME BOUNCING AROUND IN THE MEDIUM RANGE GUIDANCE BUT AN OVERALL UNSETTLED WEATHER PATTERN LOOKS LIKELY AS A SERIES OF SYSTEMS MOVE OUT OF THE PACIFIC NORTHWEST AND ACROSS THE NORTHERN ROCKIES. SPEED AND AMPLIFICATION OF THE SYSTEMS WILL BE THE BIGGEST CHALLENGE. HAVE FOLLOWED THE GFS THE CLOSEST WITH THE TRENDS AS IT HANDLED THIS LAST SYSTEM BETTER THAN EC. SOUTHWEST FLOW WILL OFFER A LOWER CHANCE OF STORMS WEDNESDAY AND THURSDAY. OPER GFS ADVERTISES AN UPPER LOW THEN TO DIG TO OUR WEST AND SOUTH FOR FRIDAY INTO SATURDAY AND COULD OFFER UP ANOTHER COOL AND UNSETTLED WEEKEND. SOME AMPLITUDE OF TROUGHINESS IS ALSO SUPPORTED BY THE GFS ENSEMBLE MEMBERS. HAVE CONTINUED WITH THE HIGHER CHANCE PRECIP CHANCES FOR FRIDAY INTO SATURDAY. NOT ABLE TO COMPLETELY BUY THIS SOLUTION THOUGH AS EC ADVERTISING LESS AMPLIFICATION AND AFTER FRIDAYS CONVECTION...THIS MODEL DRY THINGS OUT FOR SATURDAY. TEMPERATURES TRENDS LOOKED GOOD OVERALL WITH ONLY MINOR CHANGES. WARMEST DAYS WILL BE IN SOUTHWEST FLOW WEDNESDAY AND THURSDAY. FRIEDERS && .AVIATION... VFR CONDITIONS WILL GENERALLY PREVAIL OVERNIGHT WITH MID LEVEL CLOUD DECKS AND AREAS OF SHOWERS SLOWLY MIGRATING EAST BEFORE DECREASING. HOWEVER...THERE MAY BE SOME AREAS OF MVFR EAST OF KBIL TO KMLS AND BHK INTO EARLY MONDAY. STRONG WEST WINDS WILL BE PERSISTENT THROUGH THIS EVENING WITH A FEW GUSTS AROUND 40KTS AND POSSIBLY STRONGER WITHIN HEAVIER SHOWERS. BT && .PRELIMINARY POINT TEMP/POPS... MON TUE WED THU FRI SAT SUN ----------------------------------------------------------- BIL 049/073 050/077 053/080 056/081 056/076 054/074 054/073 62/W 22/T 22/T 22/T 34/T 44/T 43/T LVM 043/069 040/072 045/076 046/075 046/072 045/069 046/068 52/W 22/T 22/T 33/T 35/T 54/T 43/T HDN 046/073 050/078 051/082 055/083 056/079 054/076 054/076 92/W 22/T 22/T 22/T 34/T 44/T 43/T MLS 050/073 050/078 055/082 057/084 058/079 056/077 056/076 92/W 12/T 22/T 22/T 34/T 44/T 43/T 4BQ 047/071 048/077 052/081 056/084 057/080 055/077 055/076 62/T 22/T 32/T 21/B 33/T 34/T 43/T BHK 047/067 045/075 051/078 057/082 058/079 057/076 057/075 73/W 12/T 32/T 21/B 34/T 44/T 43/T SHR 046/071 045/073 049/078 051/080 052/076 050/073 050/073 32/W 22/T 22/T 22/T 34/T 44/T 43/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS GLASGOW MT
1139 PM MDT FRI JUN 8 2012 ...UPDATED AVIATION DISCUSSION... .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SUNDAY... STARTING TO FINALLY SEE STORMS GAINING A LITTLE MORE MOMENTUM AND COVERAGE ALONG INVERTED SURFACE TROUGH AND UNDER INCREASING UPPER LEVEL DIVERGENCE AHEAD OF APPROACHING UPPER LEVEL JET. HAVE HAD THREE LOW-END SEVERE THUNDERSTORMS SO FAR AND EXPECT SEVERE THUNDERSTORM THREAT TO CONTINUE THROUGH MIDNIGHT...MAINLY OVER THE WESTERN HALF OF THE AREA...THEN BE MORE ISOLATED OVERNIGHT. SPC MESOANALYSIS PAGE SHOWS INSTABILITY AND SHEAR PARAMETERS MAXIMIZED NW-SE OVER NE MONTANA. 850 MB JET EXPECTED TO INCREASE OVER THE NEXT FEW HOURS AND HELP TRANSPORT MORE MOISTURE INTO THE REGION...AND IN A CONVERGENCE ZONE OVER SOUTHEAST PORTIONS OF THE AREA...EXPECT AN AREA OF THUNDERSTORMS TO DEVELOP BEFORE MIDNIGHT AND TRACK NORTHEAST. IT WILL CONTINUE TO BE A NOISY NIGHT FOR THE AREA...AND HEAVY RAINFALL WILL HAVE TO BE WATCHED CAREFULLY FOR THREAT OF FLASH FLOODING. HAVE ALREADY UPDATED FORECAST EARLIER THIS EVENING...AND WILL CONTINUE TO UPDATE AS NECESSARY. MOYER ...PREVIOUS DISCUSSION... GOES WATER VAPOR IMAGERY THIS MORNING REVEALS CLOSED UPPER LOW/STORM SYSTEM MOVING INTO THE PAC-NW...WITH A SOUTHWESTERLY FLOW INTO MONTANA. THE ASSOCIATED COLD FRONT IS EXPECTED TO MOVE OVER THE DIVIDE BY AFTERNOON...THEN REACHES OUR WESTERN COUNTIES BY LATE AFTERNOON OR EARLY EVENING...MEETING UP WITH AN INVERTED SURFACE TROUGH AND INCREASING INSTABILITY. THE 12Z NAM AND GFS... ALONG WITH THE LATEST RAP SUGGEST STORM INITIAL DEVELOPMENT IN OUR FAR WEST BY LATE AFTERNOON. THE BEST INSTABILITY WILL BE A LITTLE FARTHER TO THE EAST. SO EXPECT THE POSSIBILITY OF SEVERE MAINLY AFTER 00Z. THE STRONGEST SURFACE BASED CAPE OF AROUND 2600 J/KG REMAIN IN THE SOUTHEASTERN ZONES. IN ADDITION...LIFTED INDEX VALUES OF AROUND -7C ARE INDICATED IN THE SAME AREA. SOUTHEASTERLY SURFACE WINDS VEER AND INCREASE WITH HEIGHT TO THE SOUTHWEST ALOFT...DEVELOPING DEEP LAYER SHEAR OF 35-50KTS. INVERTED V-SOUNDINGS ON BUFKIT INDICATE THE POSSIBILITY OF STRONG WINDS WITH ANY STORM. INSTABILITY DROPS OFF TOWARD THE NORTH. WITH OUR AREA UNDER THE LIKELIHOOD OF SEVERE THUNDERSTORMS ELECTED WITH THE COORDINATION OF SPC TO TO A SPECIAL SOUNDING AROUND 20Z. SO WILL CONTINUE WITH SEVERE WORDING WITH LARGE HAIL UP TO 2 INCHES... DAMAGING WINDS IN EXCESS OF 60MPH AND HEAVY RAIN POSSIBLE. MODELS SUGGEST AROUND A HALF INCH OF MOISTURE...BUT 1 HOUR FF GUIDANCE HAS ROOM FOR AROUND AN INCH OR MORE. AFTER MIDNIGHT GROWTH OF STORMS COULD DEVELOP INTO AN MCS AS THEY TREND NORTHEAST INTO NORTH DAKOTA AND SOUTHERN SASKATCHEWAN...CONTINUING WITH THE HEAVY RAIN...HAIL AND WINDS. THE FRONT MAKES IT THROUGH THE CWA BY MORNING. THERE WILL BE A BREAK IN THE ACTION AS COOLER TEMPERATURES FILTER IN. THEN OVERRUNNING MOISTURE ALONG THE COLD FRONT WILL BRING ADDITIONAL RAIN SHOWERS MAINLY THROUGH OUR EASTERN ZONES SATURDAY NIGHT. BUT WILL CONTINUE TO BROAD-BRUSH POPS. NORTHWEST WINDS BEHIND THE FRONT SHOULD BE STRONG ENOUGH TO REACH 20MPH OVER FORT PECK LAKE SATURDAY MORNING. SO WILL GO WITH AN ADVISORY. THE UPPER LOW CENTER WILL WORK ITS WAY OVER THE CWA BY SUNDAY...DRAGGING BACK SIDE MOISTURE ACROSS THE AREA FOR ADDITIONAL RAIN SHOWERS. SUNDAY APPEARS TO BE THE COOLEST DAY WITH HIGHS A BIT BELOW AVERAGE. .LONG TERM...SUNDAY NIGHT THROUGH FRIDAY... LONG TERM FORECAST PERIOD BEGINS WITH THE NORTHERN ROCKIES STORM SYSTEM FINALLY EXITING THE REGION TO THE EAST WITH SOMEWHAT CALMER WEATHER CONDITIONS...AT LEAST INITIALLY. MONDAY THROUGH WEDNESDAY...THE WEAK UPPER LEVEL RIDGE OVER THE NORTHERN ROCKIES BECOMES EVEN WEAKER AND ALLOWS MULTIPLE EMBEDDED SMALL SCALE SHORTWAVE TROUGH TO KEEP SLIGHT CHANCES FOR SCATTERED SHOWERS ACROSS OUR CWA FOR QUITE A WHILE. BY WEDNESDAY NIGHT...SOUTHWEST FLOW ALOFT RETURNS TO OUR REGION...INCREASING THE CHANCE FOR MORE THUNDERSTORMS AS ANOTHER UPPER LEVEL LOW PRESSURE SYSTEM MOVES OVER THE PACIFIC NORTHWEST. INTERESTINGLY ENOUGH...THIS LATER LOW PRESSURE SYSTEM SLOWLY MOVE SOUTHWARD ALONG THE RIDGE OF THE CASCADE RANGE AND CUTS OFF AS A LARGE AND CLOSED UPPER LOW OFF THE SOUTHERN CALIFORNIA COAST BEYOND THE SCOPE OF THIS EXTENDED FORECAST PERIOD. BMICKELSON PREVIOUS LONG TERM DISCUSSION...SUNDAY NIGHT AND MONDAY...UPPER LOW MOVES EITHER EAST (GFS) OR NORTHEAST (ECMWF) OUT OF THE AREA. WRAP AROUND MOISTURE WILL LIKELY PERSIST INTO PART OF MONDAY. WILL KEEP GOOD CHANCE OF SHOWERS IN THE FORECAST. UPPER RIDGE BUILDS INTO MONTANA MONDAY NIGHT AND TUESDAY WITH DRIER WEATHER AND A WARMING TREND. THE REMAINDER OF THE PERIOD HAS MONTANA IN SOUTHWEST FLOW ALOFT WITH AN UPPER TROUGH DIGGING OVER THE PACIFIC COAST. THIS WILL BRING FREQUENT SHORTWAVES INTO EASTERN MONTANA WITH AT LEAST A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS EVERY DAY. FORRESTER && .AVIATION... COLD FRONT/SFC TROUGH JUST ABOUT TO KGGW WILL CONTINUE TO PRESS EAST OVERNIGHT AS LOW PRESSURE MOVES INTO WESTERN ND. THUNDERSTORMS ALONG AND AHEAD OF FRONT WILL BE MOST PREVALENT AT KGGW AND KOLF THROUGH 10Z. THIS ACTIVITY MAY ACTUALLY LIFT NORTHEAST...AND JUST SKIM KGDV AND KSDY TOWARD 08-10Z...BUT CONFIDENCE HAS DECREASED SO HAVE GONE MORE OPTIMISTIC IN THE TAFS THERE. WILL HAVE A FEW HOURS OF GUSTY NW WINDS BEHIND FRONT...WITH A POSSIBLE LULL IN THE EARLY MORNING AT WRN SITES BEFORE MIXING DURING THE DAY INCREASES WINDS AGAIN. SHOWERS MAY DEVELOP IN THE VICIINTY OF KGDV AND KSDY AFT 00Z SUN...BUT CONFIDENCE NOT HIGH ENOUGH TO MENTION AT THIS TIME. MOYER && .GLASGOW WATCHES/WARNINGS/ADVISORIES... LAKE WIND ADVISORY FROM 8 AM TO 7 PM MDT SATURDAY FOR FORT PECK LAKE. && $$ WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
113 PM CDT SAT JUN 9 2012 .AVIATION... GUSTY SOUTHERLY WINDS RANGING FROM 20 TO 30 KTS WILL PREVAIL INTO THE EVENING HOURS. SHOULD THEN SEE WINDS DIMINISH SLIGHTLY AS TEMPS DROP. THEN A STRONG COLD FRONT WILL PASS OVERNIGHT WITH A SHARP SWITCH TO NW WINDS...GUSTING TO AROUND 25 KTS. THE FRONT WILL ALSO HAVE A SLIM CHANCE FOR THUNDERSTORMS...BEST CHANCE IS OVER NW NEB. BY MORNING WITH THE FRONT THROUGH...COULD SEE SOME LOW STRATUS DEVELOP BEHIND THE FRONT. MODELS IN GOOD AGREEMENT HOLDING LOW LEVEL MOISTURE ACROSS THE AREA WITH HIGH RH VALUES NEAR THE SURFACE. THE PAST COUPLE OF MORNINGS...CIGS HAVE BEEN SMALL IN AREA...BUT HAVE BEEN ABLE TO DEVELOP. WITH FRONTAL PASSAGE...AND BREEZY NW WINDS...HAVE ONLY INCLUDED SCT025 CIGS WHICH MAY BE UNDER DONE. LATER FORECAST WILL MONITOR THIS CLOSELY...HOWEVER ANY LOWER CIG THAT DEVELOPS WILL QUICKLY LIFT BY LATE MORNING. && .PREV DISCUSSION... /ISSUED 922 AM CDT SAT JUN 9 2012/ UPDATE... GAVE 1ST PERIOD TEMPS A BUMP EVERYWHERE EXCEPT THE NORTHWEST WHERE IT APPEARS COOLER AIR WILL WORK IN FROM THE COLD FRONT WHICH JUST PASSED RAPID CITY AT AROUND 12Z. HRRR AND RAP DONT HAVE THE FRONT PUNCHING THROUGH KRAP. WITH H700 MB TEMPS AROUND 14C TO 15C THIS AFTN...UPPER 90S TO NEAR 100 SHOULD OPERATE ACROSS SWRN NEB. SLIGHTLY COOLER TEMPS ACROSS THE NCNTL WITH MID 90S. PREV DISCUSSION... /ISSUED 406 AM CDT SAT JUN 9 2012/ DISCUSSION... LARGE CLOSED LOW WILL MAKE IT/S WAY EAST ACROSS THE PACIFIC NORTHWEST INTO THE NORTHERN ROCKIES TODAY. AHEAD OF THIS SYSTEM...SFC LOW PRESSURE WILL DEEPEN ACROSS NORTHEAST COLORADO AND SOUTHWEST NEBRASKA. A DRY LINE WILL MIX EAST THROUGH WESTERN NEBRASKA THIS AFTERNOON...WHILE A COLD FRONT DROPS SOUTH INTO EXTREME NORTHERN NEBRASKA AND BECOMES STATIONARY. WINDS WILL BE QUITE GUSTY FROM THE SOUTH AHEAD OF THE DRY LINE ACROSS CENTRAL NEBRASKA...WITH LIGHTER WINDS NEAR THE DRY LINE AND SFC LOW ACROSS WESTERN NEBRASKA. ACROSS NORTH CENTRAL NEBRASKA...WINDS MAY BECOME EAST AS THE COLD FRONT SLIPS SOUTH AND BECOMES STATIONARY. THE HEAT WILL BE ON...ESPECIALLY ACROSS WESTERN AND SOUTHWEST NEBRASKA INVOF AND WEST OF THE DRY LINE...WHERE HIGHS IN THE UPPER 90S ARE EXPECTED. MOISTURE WILL ADVECT NORTHWARD AND INCREASE SOME THROUGH THE DAY TO THE EAST OF THE DRYLINE ACROSS CENTRAL NEBRASKA...AND HIGHS MAY BE HELD IN THE LOWER TO MID 90S DUE TO THE INCREASING MOISTURE. LOW RELATIVE HUMIDITY VALUES WILL DEVELOP ACROSS EXTREME SOUTHWEST NEBRASKA LATE THIS AFTERNOON TO THE WEST OF THE DRY LINE...BUT WINDS APPEAR THEY WILL BE LIGHT AND NO FIRE WEATHER HEADLINES ARE ANTICIPATED. CONVECTIVE CHANCES ARE THE NEXT CONCERN. LAST SEVERAL RUNS OF THE NAM MODEL HAVE BEEN CONSISTENT IN DEVELOPING T-STORM ACTIVITY EARLY THIS EVENING ACROSS NORTH CENTRAL NEBRASKA /LATEST GEM REGIONAL ALSO SUPPORTS THIS IDEA/ INVOF OF A STATIONARY FRONT THAT WILL BE DRAPED ACROSS SHERIDAN AND CHERRY COUNTIES. THIS AREA APPEARS QUITE PRIME FOR STORM DEVELOPMENT...WITH NOSE OF STEEP LOW LEVEL LAPSE RATES COINCIDING WITH BACKED EASTERLY SFC FLOW AND POOLING MOISTURE. THIS POOLING MOISTURE LEADS TO STRONG INSTABILITY...WITH SFC BASED CAPE VALUES ON THE ORDER 2500 TO 3500 J/KG. DEEP LAYER SHEAR ALSO INCREASES DURING THE EVENING...AS WELL AS STEEPENING MID LEVEL LAPSE RATES. DESPITE A STRONGLY CAPPED ATMOSPHERE FOR MOST OF THE DAY...IT APPEARS THE CAP MAY WEAKEN SUFFICIENTLY DURING THE EVENING FOR STORM INITIATION DUE TOO CONTINUED LOW LEVEL WARM AIR ADVECTION /TEMPERATURES IN THE 90S/ THROUGH THE AFTERNOON ALONG AND SOUTH OF THE FRONT. THE ABOVE FACTORS WARRANT AT LEAST A SLIGHT CHANCE FOR STORMS...AND WILL INCLUDE IN THE FORECAST. SOUTHWARD EXTENT OF CONVECTION INTO WESTERN NEBRASKA IS IN DOUBT...HOWEVER TEMPERATURES IN THE 90S TO AROUND 100 DEGREES AND NEAR DRY ADIABATIC LOW LEVEL LAPSE RATES...COULD LEAD TO AN ISOLATED STORM INVOF OF THE DRY LINE. THIS SEEMS MOST PROBABLE NEAR THE SFC LOW...WHICH SHOULD RESIDE ACROSS EXTREME SOUTHWEST NEBRASKA INTO THE FAR SOUTHEAST PART OF THE NEBRASKA PANHANDLE. HAVE ADDED A LATE AFTERNOON ISOLATED MENTION IN THESE AREAS. INTERESTING THAT THE LATEST RUN OF THE HIGH RESOLUTION NMM MODEL ACTUALLY SHOW STORMS ORGANIZING ACROSS SOUTHWEST NEBRASKA DURING THE EVENING. THIS SCENARIO SEEMS UNLIKELY WITH SUCH WARM MID LEVEL TEMPERATURES AND THE AREA BEING REMOVED FROM THE BETTER UPPER LEVEL SUPPORT RESIDING THE NORTH. NEVERTHELESS WILL BRING SOME ISOLATED THUNDER MENTION ABOUT AS FAR EAST AS HIGHWAY 83 DURING THE EVENING. THIS WILL ACCOUNT FOR ANY STORM FIRING ON THE DRY LINE HOLDING TOGETHER. AS UPPER LOW MOVES EAST INTO SOUTHERN CANADA...A COLD FRONT WILL SWEEP IN FROM THE NORTHWEST SATURDAY MORNING. COOLING MID LEVEL TEMPERATURES MAY ALLOW FOR A FEW SHOWERS/T-STORMS TO DEVELOP ACROSS EASTERN PORTIONS OF NORTH CENTRAL NEBRASKA SATURDAY MORNING AS THE FRONT PASSES. OTHERWISE VERY DRY AIR IS INDICATED TO SWEEP EAST OFF THE ROCKIES...WITH WARM AND DRY CONDITIONS EXPECTED THROUGH MONDAY NIGHT. ANOTHER TROUGH WILL BECOME ESTABLISHED ACROSS THE PACIFIC NORTHWEST BY MID TO LATE WEEK...AND HAVE SOME SLIGHT CHANCES FOR T-STORMS ACROSS THE AREA AS THIS TROUGH BECOMES ESTABLISHED. AM HESITANT TO GO MUCH OVER SLIGHT FOR RAIN CHANCES AT THIS TIME...AS MODELS HAVE SEEMED TO BE OVER DOING RAIN AMOUNTS IN THE OUTER PERIODS. OTHERWISE...WARM WEATHER TO CONTINUE. FIRE WEATHER... TEMPERATURES WELL ABOVE AVERAGE TODAY WILL BRING LOW LEVEL AND SURFACE RELATIVE HUMIDITY TO CRITICAL LEVELS BELOW 15 PERCENT IN THE EASTERN PANHANDLE (ZONE 204) AND THE FRENCHMAN BASIN (ZONE 210). CURRENT INDICATIONS ARE THAT WIND WILL BE AROUND 15 MPH IN THE FRENCHMAN BASIN WITH GUSTS OVER 20 MPH BUT LESS THAN 25 MPH. REPORTS AROUND THE AREA INDICATE THAT RECENT RAIN HAS REDUCED THE RISK OF EXTREME FIRE BEHAVIOR. THEREFORE... THOUGH THINGS IN WESTERN AND SOUTHWEST NEBRASKA WILL NEED TO BE MONITORED...WE WILL NOT ISSUE ANY FIRE HEADLINES AT THIS TIME. && .LBF WATCHES/WARNINGS/ADVISORIES...NONE. && $$ AVIATION...MASEK
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
922 AM CDT SAT JUN 9 2012 .UPDATE... GAVE 1ST PERIOD TEMPS A BUMP EVERYWHERE EXCEPT THE NORTHWEST WHERE IT APPEARS COOLER AIR WILL WORK IN FROM THE COLD FRONT WHICH JUST PASSED RAPID CITY AT AROUND 12Z. HRRR AND RAP DONT HAVE THE FRONT PUNCHING THROUGH KRAP. WITH H700 MB TEMPS AROUND 14C TO 15C THIS AFTN...UPPER 90S TO NEAR 100 SHOULD OPERATE ACROSS SWRN NEB. SLIGHTLY COOLER TEMPS ACROSS THE NCNTL WITH MID 90S. && .PREV DISCUSSION... /ISSUED 655 AM CDT SAT JUN 9 2012/ AVIATION... WIND WILL ALSO BE OF CONCERN TODAY. BY ABOUT 15Z...WE EXPECT THE WIND TO BE 170-190 AT 14-18G22-26KT ALONG AND EAST OF A VTN- TIF- IML LINE. LATE TONIGHT...AROUND 09Z...A FRONT WILL COME ACROSS A VTN-TIF-LBF LINE AND WIND WILL SWITCH TO THE NORTHWEST 300-320 AT 14-16G22-26KT. IT IS EXPECTED TO CROSS AN ONL-BBW LINE 12-15Z SUNDAY. IN SOUTHWEST NEBRASKA NEAR IML AND OGA...MARGINAL CEILINGS OF ABOUT 1500 FEET AGL ARE LIKELY...BUT THEY SHOULD SCATTER OUT FAIRLY QUICKLY AFTER 15Z. OTHERWISE...UNRESTRICTED CEILING AND VISIBILITY WILL CONTINUE TODAY...TONIGHT AND INTO EARLY SUNDAY. ISOLATED THUNDERSTORMS ARE EXPECTED AFTER 21Z ALONG AND WEST OF A MRR-MHN-IML LINE. VERY DRY AIR IN THE SFC-600MB LAYER WILL SERVE TO ENHANCE DOWNDRAFTS AND COULD PRODUCE MICROBURST WIND GUSTS EXCEEDING 45KT. HAIL IS ALSO POSSIBLE WITH THE STORMS. FOR THE AREA EAST OF THAT LINE...WARM AIR ALOFT WILL CAP UPDRAFTS AND RETARD THUNDERSTORM DEVELOPMENT. PREV DISCUSSION... /ISSUED 406 AM CDT SAT JUN 9 2012/ DISCUSSION... LARGE CLOSED LOW WILL MAKE IT/S WAY EAST ACROSS THE PACIFIC NORTHWEST INTO THE NORTHERN ROCKIES TODAY. AHEAD OF THIS SYSTEM...SFC LOW PRESSURE WILL DEEPEN ACROSS NORTHEAST COLORADO AND SOUTHWEST NEBRASKA. A DRY LINE WILL MIX EAST THROUGH WESTERN NEBRASKA THIS AFTERNOON...WHILE A COLD FRONT DROPS SOUTH INTO EXTREME NORTHERN NEBRASKA AND BECOMES STATIONARY. WINDS WILL BE QUITE GUSTY FROM THE SOUTH AHEAD OF THE DRY LINE ACROSS CENTRAL NEBRASKA...WITH LIGHTER WINDS NEAR THE DRY LINE AND SFC LOW ACROSS WESTERN NEBRASKA. ACROSS NORTH CENTRAL NEBRASKA...WINDS MAY BECOME EAST AS THE COLD FRONT SLIPS SOUTH AND BECOMES STATIONARY. THE HEAT WILL BE ON...ESPECIALLY ACROSS WESTERN AND SOUTHWEST NEBRASKA INVOF AND WEST OF THE DRY LINE...WHERE HIGHS IN THE UPPER 90S ARE EXPECTED. MOISTURE WILL ADVECT NORTHWARD AND INCREASE SOME THROUGH THE DAY TO THE EAST OF THE DRYLINE ACROSS CENTRAL NEBRASKA...AND HIGHS MAY BE HELD IN THE LOWER TO MID 90S DUE TO THE INCREASING MOISTURE. LOW RELATIVE HUMIDITY VALUES WILL DEVELOP ACROSS EXTREME SOUTHWEST NEBRASKA LATE THIS AFTERNOON TO THE WEST OF THE DRY LINE...BUT WINDS APPEAR THEY WILL BE LIGHT AND NO FIRE WEATHER HEADLINES ARE ANTICIPATED. CONVECTIVE CHANCES ARE THE NEXT CONCERN. LAST SEVERAL RUNS OF THE NAM MODEL HAVE BEEN CONSISTENT IN DEVELOPING T-STORM ACTIVITY EARLY THIS EVENING ACROSS NORTH CENTRAL NEBRASKA /LATEST GEM REGIONAL ALSO SUPPORTS THIS IDEA/ INVOF OF A STATIONARY FRONT THAT WILL BE DRAPED ACROSS SHERIDAN AND CHERRY COUNTIES. THIS AREA APPEARS QUITE PRIME FOR STORM DEVELOPMENT...WITH NOSE OF STEEP LOW LEVEL LAPSE RATES COINCIDING WITH BACKED EASTERLY SFC FLOW AND POOLING MOISTURE. THIS POOLING MOISTURE LEADS TO STRONG INSTABILITY...WITH SFC BASED CAPE VALUES ON THE ORDER 2500 TO 3500 J/KG. DEEP LAYER SHEAR ALSO INCREASES DURING THE EVENING...AS WELL AS STEEPENING MID LEVEL LAPSE RATES. DESPITE A STRONGLY CAPPED ATMOSPHERE FOR MOST OF THE DAY...IT APPEARS THE CAP MAY WEAKEN SUFFICIENTLY DURING THE EVENING FOR STORM INITIATION DUE TOO CONTINUED LOW LEVEL WARM AIR ADVECTION /TEMPERATURES IN THE 90S/ THROUGH THE AFTERNOON ALONG AND SOUTH OF THE FRONT. THE ABOVE FACTORS WARRANT AT LEAST A SLIGHT CHANCE FOR STORMS...AND WILL INCLUDE IN THE FORECAST. SOUTHWARD EXTENT OF CONVECTION INTO WESTERN NEBRASKA IS IN DOUBT...HOWEVER TEMPERATURES IN THE 90S TO AROUND 100 DEGREES AND NEAR DRY ADIABATIC LOW LEVEL LAPSE RATES...COULD LEAD TO AN ISOLATED STORM INVOF OF THE DRY LINE. THIS SEEMS MOST PROBABLE NEAR THE SFC LOW...WHICH SHOULD RESIDE ACROSS EXTREME SOUTHWEST NEBRASKA INTO THE FAR SOUTHEAST PART OF THE NEBRASKA PANHANDLE. HAVE ADDED A LATE AFTERNOON ISOLATED MENTION IN THESE AREAS. INTERESTING THAT THE LATEST RUN OF THE HIGH RESOLUTION NMM MODEL ACTUALLY SHOW STORMS ORGANIZING ACROSS SOUTHWEST NEBRASKA DURING THE EVENING. THIS SCENARIO SEEMS UNLIKELY WITH SUCH WARM MID LEVEL TEMPERATURES AND THE AREA BEING REMOVED FROM THE BETTER UPPER LEVEL SUPPORT RESIDING THE NORTH. NEVERTHELESS WILL BRING SOME ISOLATED THUNDER MENTION ABOUT AS FAR EAST AS HIGHWAY 83 DURING THE EVENING. THIS WILL ACCOUNT FOR ANY STORM FIRING ON THE DRY LINE HOLDING TOGETHER. AS UPPER LOW MOVES EAST INTO SOUTHERN CANADA...A COLD FRONT WILL SWEEP IN FROM THE NORTHWEST SATURDAY MORNING. COOLING MID LEVEL TEMPERATURES MAY ALLOW FOR A FEW SHOWERS/T-STORMS TO DEVELOP ACROSS EASTERN PORTIONS OF NORTH CENTRAL NEBRASKA SATURDAY MORNING AS THE FRONT PASSES. OTHERWISE VERY DRY AIR IS INDICATED TO SWEEP EAST OFF THE ROCKIES...WITH WARM AND DRY CONDITIONS EXPECTED THROUGH MONDAY NIGHT. ANOTHER TROUGH WILL BECOME ESTABLISHED ACROSS THE PACIFIC NORTHWEST BY MID TO LATE WEEK...AND HAVE SOME SLIGHT CHANCES FOR T-STORMS ACROSS THE AREA AS THIS TROUGH BECOMES ESTABLISHED. AM HESITANT TO GO MUCH OVER SLIGHT FOR RAIN CHANCES AT THIS TIME...AS MODELS HAVE SEEMED TO BE OVER DOING RAIN AMOUNTS IN THE OUTER PERIODS. OTHERWISE...WARM WEATHER TO CONTINUE. FIRE WEATHER... TEMPERATURES WELL ABOVE AVERAGE TODAY WILL BRING LOW LEVEL AND SURFACE RELATIVE HUMIDITY TO CRITICAL LEVELS BELOW 15 PERCENT IN THE EASTERN PANHANDLE (ZONE 204) AND THE FRENCHMAN BASIN (ZONE 210). CURRENT INDICATIONS ARE THAT WIND WILL BE AROUND 15 MPH IN THE FRENCHMAN BASIN WITH GUSTS OVER 20 MPH BUT LESS THAN 25 MPH. REPORTS AROUND THE AREA INDICATE THAT RECENT RAIN HAS REDUCED THE RISK OF EXTREME FIRE BEHAVIOR. THEREFORE... THOUGH THINGS IN WESTERN AND SOUTHWEST NEBRASKA WILL NEED TO BE MONITORED...WE WILL NOT ISSUE ANY FIRE HEADLINES AT THIS TIME. && .LBF WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM/EXTENDED...CDC AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
108 PM EDT SAT JUN 9 2012 .SYNOPSIS... A WARM FRONT STRETCHES FROM NEAR ROCHESTER SOUTHEAST THROUGH BINGHAMTON WITH COOLER TEMPERATURES TO THE NORTHEAST ACROSS SYRACUSE, ROME, ONEONTA, AND MONTECELLO. WARMER TEMPERATURES ARE TO THE SOUTHWEST ACROSS ELMIRA, TOWANDA, AND SCRANTON. SCATTERED SHOWERS HAVE BEEN MOVING SOUTHEAST ALONG THIS FRONT WHICH WILL REMAIN IN THE GENERAL VICINITY THROUGH SUNDAY. AFTERNOON THUNDER IS POSSIBLE WITH THE SHOWERS. MONDAY LOOKS WARMER AND MORE HUMID WITH MOSTLY RAIN-FREE WEATHER...OUTSIDE OF WIDELY SCATTERED AFTERNOON THUNDERSTORMS. && .NEAR TERM /THROUGH TONIGHT/... 11 AM UPDATE...TOUCHED UP POPS AND TEMPS FOR MORNING TRENDS. FRONT LIES FROM EAST OF ROC TO BGM TO MSV AND TEMPERATURES TO THE NE ARE RUNNING A LITTLE COOLER THAN FORECASTED HANGING IN THE UPPER 50S AND LOWER 60S...PARTLY BECAUSE OF THE SHOWERS ALONG AND NE OF THIS BOUNDARY. TO THE SE SHOWERS HAVE BEEN WIDELY SCATTERED AND THERE HAS BEEN MORE SUNSHINE ALLOWING TEMPERATURES TO CLIMB INTO THE 70S. HRRR SEEMS TO HAVE A GOOD HANDLE ON THE PRECIP TRENDS WHICH KEEPS SCATTERED SHOWERS MOVING ALONG THE FRONTAL ZONE FROM NW TO SE THROUGH THE CENTER OF OUR FORECAST AREA THROUGH THE AFTERNOON HOURS BUT WITH LESS COVERAGE THAN THIS MORNING. THE 06Z NAM GIVES US CAPE THIS AFTERNOON BETWEEN 750 AND 1000 BUT HAS TOO MUCH MOISTURE IN THE LOWEST LEVELS SO THE LOW END OF THAT SEEMS MORE REASONABLE. THE DEW POINTS THIS MORNING HAVE BEEN IN THE 50S WITH SOME INCREASE IN RESPONSE TO THE RAIN. ISOLD TSTMS ARE POSSIBLE AND MOST LIKELY IN THE WARMER SW ZONES THIS AFTN/EVE. CHANCE SHOWERS REMAINS OVERNIGHT WITH THE HIGHEST POP ALONG THE FRONTAL ZONE. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... MODELS SHOW THE OLD SFC BNDRY LINGERING OVER THE ERN ZONES INTO MON DESPITE THE RDGG ALOFT. THIS WILL HELP ENHANCE THE CHANCE OF CONV SHWRS AND ISLTD TRWS OVER THE HIER TERRAIN OF THE ERN ZONES. OTRW...RDG LINE SLOWLY SLIDES EAST THRU THE PD ALLOWING A SFC TROF AND SRN STREAM WV TO APRCH FOR TUE. MODELS CONT TO SHOW THE SYSTEM TO BE WELL SUPPLIED WITH MOISTURE AS IT LFTS NWRD OUT OF THE GULF. DVLPG UA JET BY TUES AHD OF THE SFC COLD FNT WILL HELP WRING OUT THE MOISTURE OVER THE AREA ON TUE. LUCKILY...SYSTEM SEEMS QUITE PROGRESSIVE...AT LEAST THRU THE SHRT TERM PD...WITH GFS FCSTD PWS OF BETTER THAN 1.50 INCHES. IT WILL BE QUITE WARM FOR THE PD...ESP SUN AND MON WITH TEMPS PUSHING 90F IN THE LWR ELEVATIONS OF THE SRN AND WRN ZONES. ATTM IT APPEARS WE WILL BE WELL BLO ANY HEAT FLAG THRESHOLDS. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... PD BEGINS AS A COLD FNT IS PUSHING THRU THE FCST AREA. INITIAL TIMING AMONG THE OPERATIONAL MODELS IS GOOD...THEN THE GFS DVLPS A WV ALONG THE FNT OVER THE MID ATLANTIC...DELAYING THE EWRD PROGRESS ON WED. THIS COULD CAUSE SOME SHWRS AND TRWS TO LINGER OVER THE ERN ZONES INTO THU. ECMWF INDICATES SOME TROFINESS OVER WRN NEW ENG AS WELL...SO BEST BET FCST IS TO CONT SOME CHANCE POPS THRU MUCH OF THE FCST PD...WITH THE HIGHEST CHANCE OVER THE EAST NEARER THE STALLED FNT OR SFC TROF. ALSO...BOTH MODELS SHOW ONLY WEAK RDGG SFC AND ALOFT THRU THE PD...SO SOME CONV PSBL AT ALMOST ANY TIME. DFRNCS IN THE SFC PTRN DID MAKE SOME DFRNC IN THE FCSTD TEMPS FOR THE PD. DECIDED TO START WITH HPC GUID FOR TEMPS...THEN BLENDED IN SOME OF THE GFS BASED GUID TO BETTER ACCOUNT FOR THE UNCERTAINTY ...AND TO BETTER COMPROMISE WITH SURROUNDING OFFICES. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... VFR IS EXPECTED TO PREVAIL FOR MOST OF THIS FORECAST PERIOD WITH A COUPLE TIMES OF EXCEPTION. AN UPPER LEVEL DISTURBANCE WILL RACE ACROSS THE UPPER GREAT LAKES EARLY THIS MORNING AND SLIDE ACROSS NY AND NORTHERN PA WITH WIDESPREAD SHOWERS AND CIGS LOWERING TO BETWEEN FL050-100. POCKETS OF ENHANCED SHOWER ACTIVITY COULD CREATE BRIEF MVFR CIGS AND VSBYS DURING THE 10Z-15Z PERIOD. WITH THE PASSAGE OF THE UPPER WAVE OVERCAST CIGS ARE FORECAST TO DISSIPATE TO SCT-BKN AFT 16Z. MODELS THEN SUGGEST INCREASING LOW LEVEL INSTABILITY DUE TO THE DAYTIME HEATING AND POOLING MOISTURE ALONG A STALLING FRONTAL BOUNDARY ACROSS THE SOUTHWEST PORTION OF NEW YORK AND NORTH CENTRAL PA. THIS WILL CREATE AN ENVIRONMENT FAVORABLE FOR A SCATTERED CONVECTIVE THREAT DURING MAINLY THE 18Z-00Z TIME FRAME...ALTHOUGH WITH A SECONDARY UPPER DISTURBANCE SUGGESTED BY OUR COMPUTER MODELS TO DROP INTO THE REGION THIS EVENING...SOME ISOLD ACTIVITY COULD CONTINUE AFTER DARK AND THROUGH 06Z...ESPECIALLY IN THE VCNTY OF KELM-KBGM-KAVP. NOT ENOUGH CONFIDENCE TO INCLUDE A PROB FORECAST AFT 00Z TONIGHT...BUT DO HAVE MENTION OF A RISK OF TSRA ACTIVITY AFFECTING TERMINAL OPS THIS AFTERNOON. OUTLOOK... SAT NGT...CHC MVFR IN ISOLD-SCT TSRA SUN/MON...MAINLY VFR...BUT VLY FOG PSBL EACH MRNG. TUE...VFR GIVING WAY TO MVFR IN SCT TSRA WED...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...BMW NEAR TERM...BMW SHORT TERM...DGM LONG TERM...DGM AVIATION...JAB
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1123 AM EDT SAT JUN 9 2012 .SYNOPSIS... A WARM FRONT STRETCHES FROM NEAR ROCHESTER SOUTHEAST THROUGH BINGHAMTON WITH COOLER TEMPERATURES TO THE NORTHEAST ACROSS SYRACUSE, ROME, ONEONTA, AND MONTECELLO. WARMER TEMPERATURES ARE TO THE SOUTHWEST ACROSS ELMIRA, TOWANDA, AND SCRANTON. SCATTERED SHOWERS HAVE BEEN MOVING SOUTHEAST ALONG THIS FRONT WHICH WILL REMAIN IN THE GENERAL VICINITY THROUGH SUNDAY. AFTERNOON THUNDER IS POSSIBLE WITH THE SHOWERS. MONDAY LOOKS WARMER AND MORE HUMID WITH MOSTLY RAIN-FREE WEATHER...OUTSIDE OF WIDELY SCATTERED AFTERNOON THUNDERSTORMS. && .NEAR TERM /THROUGH TONIGHT/... 11 AM UPDATE...TOUCHED UP POPS AND TEMPS FOR MORNING TRENDS. FRONT LIES FROM EAST OF ROC TO BGM TO MSV AND TEMPERATURES TO THE NE ARE RUNNING A LITTLE COOLER THAN FORECASTED HANGING IN THE UPPER 50S AND LOWER 60S...PARTLY BECAUSE OF THE SHOWERS ALONG AND NE OF THIS BOUNDARY. TO THE SE SHOWERS HAVE BEEN WIDELY SCATTERED AND THERE HAS BEEN MORE SUNSHINE ALLOWING TEMPERATURES TO CLIMB INTO THE 70S. HRRR SEEMS TO HAVE A GOOD HANDLE ON THE PRECIP TRENDS WHICH KEEPS SCATTERED SHOWERS MOVING ALONG THE FRONTAL ZONE FROM NW TO SE THROUGH THE CENTER OF OUR FORECAST AREA THROUGH THE AFTERNOON HOURS BUT WITH LESS COVERAGE THAN THIS MORNING. THE 06Z NAM GIVES US CAPE THIS AFTERNOON BETWEEN 750 AND 1000 BUT HAS TOO MUCH MOISTURE IN THE LOWEST LEVELS SO THE LOW END OF THAT SEEMS MORE REASONABLE. THE DEW POINTS THIS MORNING HAVE BEEN IN THE 50S WITH SOME INCREASE IN RESPONSE TO THE RAIN. ISOLD TSTMS ARE POSSIBLE AND MOST LIKELY IN THE WARMER SW ZONES THIS AFTN/EVE. CHANCE SHOWERS REMAINS OVERNIGHT WITH THE HIGHEST POP ALONG THE FRONTAL ZONE. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... 520 AM SAT UPDATE... UPR-LVL FORCING IS EXPECTED TO WANE ACRS THE RGN FROM TNT...RIGHT INTO MON...WITH BUILDING HGTS ALOFT ACRS MOST OF THE ERN CONUS THIS PD. THUS...OTHER THAN ISOLD-SCTD CONVECTION...FAVORED NEAR THE LINGERING SFC BNDRY SUN...AND DURG PEAK HTG ON MON...CONDS SHOULD BE LARGELY RAIN-FREE. TEMPS SHOULD BE WARMER ON SUN...AS COMPARED TO TDY (HIGHS MAINLY IN THE 80S)...WITH READINGS WARMER STILL ON MON (TEMPS MAKING A RUN AT 90 IN OUR NORMALLY WARMER URBANIZED VLYS (NEAR KSYR AND KAVP)). BY LATER MON NGT/EARLY TUE...THE PROSPECTS FOR SHRA/TSRA MAY BEGIN TO SLOWLY INCREASE FROM NW-SE...OWING TO HGT FALLS ALOFT AND THE GRADUAL APPRCH OF A COLD FRNT FROM THE UPPER MIDWEST. && .LONG TERM /TUESDAY THROUGH FRIDAY/... 4 AM SAT UPDATE... THE UPPER RIDGE OVER THE EAST DURING THE LATTER HALF OF THIS WEEKEND AND EARLY NEXT WEEK LOOKS TO BE BROKEN DOWN FROM LATER MONDAY INTO TUESDAY BY MOST OF THE MED RANGE SOLUTIONS. THIS SHOULD ALLOW A COLD FRONT APPROACHING FROM THE WEST TO PASS THROUGH OUR REGION...TAKING DEEP GULF MOISTURE AND MUGGY CONDITIONS WITH IT. SOLUTIONS SUGGEST THAT THERE IS A GOOD LIKELY HOOD FOR SHOWERS AND THUNDERSTORMS MONDAY NIGHT THROUGH TUESDAY...BUT IS STILL UNCERTAINTY ENOUGH AT THAT TIME RANGE TO HOLD BACK ON A DEFINITIVE CALL. LATER ON THROUGH THE WEEK...MODEL SOLUTIONS CONTINUE TO DIFFER IN ESTABLISHING A WESTERN ATLANTIC BLOCKING LOW...AND WHERE ANY DISTURBANCES ALONG THE STALLED OFFSHORE FRONT WILL FORM AND THEIR EFFECT BACK HERE. LATEST ECMWF MOVES THE FRONT FURTHEST EAST WITH HIGH PRESSURE AND MAINLY DRY WX WORKING IN AFTER WEDS. GFS AND GGEM SUGGEST HIGHER PROBABILITY FOR SHOWERS/TSTMS THROUGH WEDNESDAY INTO THURSDAY...ESPECIALLY OVER OUR EASTERN HALF. MY HUNCH IS THE FORECAST PROBABLY DOESN`T NEED AS MUCH MENTION OF SHOWERS/TSTMS AS WE HAVE ON WEDS-THURS...BUT WILL LEAVE THE SCHC-CHC POPS MENTIONED. TEMPERATURES ON TUESDAY COULD BE SIGNIFICANTLY WARM IF THERE WASN`T GOING TO BE CLOUD COVER. OTHERWISE SEASONAL CONDITIONS IN THE UPPER 70S-LOW 80S WILL PREVAIL POST FRONTAL WEDNESDAY...THURSDAY AND FRIDAY. STUCK CLOSE TO PREVIOUS FORECAST WITH A BLEND OF 00Z MOS GUIDANCE. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... VFR IS EXPECTED TO PREVAIL FOR MOST OF THIS FORECAST PERIOD WITH A COUPLE TIMES OF EXCEPTION. AN UPPER LEVEL DISTURBANCE WILL RACE ACROSS THE UPPER GREAT LAKES EARLY THIS MORNING AND SLIDE ACROSS NY AND NORTHERN PA WITH WIDESPREAD SHOWERS AND CIGS LOWERING TO BETWEEN FL050-100. POCKETS OF ENHANCED SHOWER ACTIVITY COULD CREATE BRIEF MVFR CIGS AND VSBYS DURING THE 10Z-15Z PERIOD. WITH THE PASSAGE OF THE UPPER WAVE OVERCAST CIGS ARE FORECAST TO DISSIPATE TO SCT-BKN AFT 16Z. MODELS THEN SUGGEST INCREASING LOW LEVEL INSTABILITY DUE TO THE DAYTIME HEATING AND POOLING MOISTURE ALONG A STALLING FRONTAL BOUNDARY ACROSS THE SOUTHWEST PORTION OF NEW YORK AND NORTH CENTRAL PA. THIS WILL CREATE AN ENVIRONMENT FAVORABLE FOR A SCATTERED CONVECTIVE THREAT DURING MAINLY THE 18Z-00Z TIME FRAME...ALTHOUGH WITH A SECONDARY UPPER DISTURBANCE SUGGESTED BY OUR COMPUTER MODELS TO DROP INTO THE REGION THIS EVENING...SOME ISOLD ACTIVITY COULD CONTINUE AFTER DARK AND THROUGH 06Z...ESPECIALLY IN THE VCNTY OF KELM-KBGM-KAVP. NOT ENOUGH CONFIDENCE TO INCLUDE A PROB FORECAST AFT 00Z TONIGHT...BUT DO HAVE MENTION OF A RISK OF TSRA ACTIVITY AFFECTING TERMINAL OPS THIS AFTERNOON. OUTLOOK... SAT NGT...CHC MVFR IN ISOLD-SCT TSRA SUN/MON...MAINLY VFR...BUT VLY FOG PSBL EACH MRNG. TUE...VFR GIVING WAY TO MVFR IN SCT TSRA WED...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...BMW NEAR TERM...BMW SHORT TERM...MLJ LONG TERM...DGM AVIATION...JAB
AREA FORECAST DISCUSSION
NWS BUFFALO NY
737 AM EDT SAT JUN 9 2012 .SYNOPSIS... A WARM FRONT WILL LIFT ACROSS THE REGION TODAY...BRINGING ANOTHER ROUND OF SHOWERS AND POSSIBLY A THUNDERSTORM. FOLLOWING THE FRONT WILL BE A FLOW OF INCREASINGLY WARMER AND MORE MOIST AIR WHICH WILL LAST INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... IN GENERAL TERMS...A WARM FRONT WILL VERY GRADUALLY LIFT ACROSS THE REGION TODAY AND TONIGHT. FOR NOW...THE BOUNDARY IS QUITE DIFFUSE AT THE SURFACE...AND IS EASIER IDENTIFIED LOOKING AT 850 MB TEMPERATURE GRADIENT RATHER THAN SURFACE FEATURES. AT 700 AM THIS BOUNDARY EXTENDED ACROSS THE GREAT LAKES FROM LAKE SUPERIOR TO LAKE ONTARIO. THIS BOUNDARY WILL BE THE FOCUS OF SHOWERS AND THUNDERSTORM ACTIVITY... WITH AN AREA OF SHOWERS AND A FEW THUNDERSTORMS CROSSING LAKE HURON DURING THE EARLY MORNING HOURS. A CONSENSUS OF 00Z MODEL RUNS OF THE GFS/RGEM/NAM ARE GENERALLY FASTER WITH THE ONSET OF SHOWERS THAN PREVIOUS RUNS...ALL GENERALLY KEYING ON THIS UPSTREAM CONVECTION. THE HRRR IS ALSO FAIRLY SIMILAR...WITH GENERALLY MORE SHOWERS LIKELY DURING THE MORNING HOURS. SURFACE BASED INSTABILITY IS MARGINAL...SLIGHTLY DURING THE AFTERNOON HOURS. THE HRRR...AND THE MAJORITY OF OTHER GUIDANCE SUGGEST FAIRLY SPARSE COVERAGE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON. GIVEN THE LACK OF A STRONG SHORTWAVE...AND LIMITED DAYTIME HEATING...SEE THE THREAT FOR SEVERE WEATHER AS MARGINAL...AND CONFINED TO THE AFTERNOON HOURS. THIS WAVE WILL LIKELY EXIT TO THE EAST OF THE CWA EITHER LATE MORNING OR EARLY AFTERNOON...WITH A PARTIAL CLEARING POSSIBLE SOUTH OF THE FRONT. THERE STILL MAY BE SOME DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS...ESPECIALLY IN THE VICINITY OF THE FRONT...WHICH SHOULD BE STALLED FROM TORONTO-ROCHESTER-BINGHAMTON. AWAY FROM THE BOUNDARY STANDS A DECENT CHANCE FOR FAIR WEATHER THIS AFTERNOON...OUTSIDE OF A STRAY SHOWER. TEMPERATURES WILL ALSO WARM TODAY...ESPECIALLY IN THE SOUTHERN TIER WHERE HIGHS WILL LIKELY APPROACH OR TOP 80. FOR TONIGHT...THE FRONT WILL CONTINUE ITS SLOW NORTHWARD PROGRESSION. THE FOCUS FOR SHOWERS WILL LIFT WITH IT...THOUGH SHOWERS ACTIVITY SHOULD DIMINISH WITH THE LOSS OF DAYTIME HEATING...EVENTUALLY TAPERING OFF TOWARD DAYBREAK SUNDAY MORNING. LOWS WILL BE ON THE WARM SIDE..ONLY DROPPING INTO THE UPPER 50S TO LOWER 60S. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... ON SUNDAY...STRONG RIDGING ALOFT WILL BUILD ACROSS THE REGION FOLLOWING THE DEPARTURE OF THE WARM FRONT...WHICH WILL MOVE FROM OUR FAR EASTERN ZONES INTO EASTERN NEW YORK AND NEW ENGLAND THROUGH THE DAY. STRONG SUBSIDENCE ASSOCIATED WITH THE BUILDING UPPER RIDGE WILL BY AND LARGE LEAD TO A MAINLY DRY DAY ALONG WITH A CONSIDERABLE AMOUNT OF SUNSHINE...THOUGH A FEW ISOLATED SHOWERS STILL CANNOT BE TOTALLY RULED OUT ALONG THE DEPARTING WARM FRONT IN THE MORNING... AND ACROSS THE HIGHER TERRAIN OF THE FAR INTERIOR SOUTHERN TIER AND FINGER LAKES IN THE AFTERNOON. 850 MB TEMPS WARMING TO +14C TO +16C WILL BE SUPPORTIVE OF WIDESPREAD HIGHS IN THE LOWER TO MID 80S... WHILE HUMIDITY LEVELS REMAIN AT MODEST LEVELS WITH DEWPOINTS LINGERING IN THE UPPER 50S TO LOWER 60S. DURING THE COURSE OF SUNDAY NIGHT AND MONDAY...THE AXIS OF THE STRONG UPPER RIDGE WILL EVER SO SLOWLY DRIFT EAST INTO NEW ENGLAND. CONTINUED LARGE-SCALE SUBSIDENCE ASSOCIATED WITH THIS FEATURE WILL MAINTAIN DRY WEATHER THROUGH SUNDAY NIGHT AND THE FIRST HALF OF MONDAY...WITH MIDSUMMERLIKE HEAT CONTINUING. WITH A SOUTHERLY RETURN FLOW DEVELOPING AT THE LOW LEVELS AND SURFACE DEWPOINTS ON A SLOW BUT STEADY RISE...EXPECT MOST LOCATIONS TO EXPERIENCE OVERNIGHT LOWS IN THE LOWER TO MID 60S SUNDAY NIGHT. MONDAY STILL LOOKS TO BE THE HOTTEST DAY OF THE UPCOMING WEEK...WHEN 850 MB TEMPS OF +16C TO +18C WILL SUPPORT WIDESPREAD MAX TEMPS IN THE MID TO UPPER 80S...WITH SOME OF OUR USUAL WARM SPOTS IN THE GENESEE VALLEY AND FINGER LAKES POTENTIALLY REACHING THE 90 DEGREE MARK. COUPLED WITH DEWPOINTS RISING INTO THE MID 60S...THESE TEMPERATURES WILL MAKE FOR FAIRLY UNCOMFORTABLE CONDITIONS BY MONDAY AFTERNOON. LATER MONDAY AND ESPECIALLY MONDAY NIGHT...A FAIRLY IMPRESSIVE UPPER-LEVEL TROUGH AND ASSOCIATED COLD FRONT WILL WORK EAST INTO THE GREAT LAKES FROM THE NORTHERN PLAINS STATES AND CENTRAL CANADA. AT THE SURFACE...A DEVELOPING SURFACE WAVE OVER THE TENNESSEE VALLEY WILL STRENGTHEN AS IT LIFTS NORTHWARD ALONG THE ADVANCING COLD FRONT...HELPING TO TRANSPORT INCREASING AMOUNTS OF LIFT AND MOISTURE NORTHWARD FROM THE WIDE-OPEN GULF OF MEXICO. THIS WILL LEAD TO AN INCREASING POTENTIAL FOR CONVECTION FROM LATER MONDAY THROUGH MONDAY NIGHT...WITH THE 00Z GUIDANCE SUITE CONTINUING TO SUPPORT A FASTER ARRIVAL OF THIS SYSTEM AND ITS ASSOCIATED CONVECTION...POSSIBLY AS EARLY AS LATE MONDAY AFTERNOON/EARLY MONDAY EVENING ACROSS FAR WESTERN NEW YORK PER A CONSENSUS OF THE NAM/GFS/GEM. WILL THEREFORE BEGIN CHANCE POPS ACROSS FAR WESTERN NEW YORK DURING THIS TIME FRAME...BEFORE SPREADING THESE EASTWARD ACROSS THE REMAINDER OF THE AREA MONDAY NIGHT. OTHERWISE...WARM AND MUGGY CONDITIONS WILL CONTINUE...WITH OVERNIGHT LOWS MONDAY NIGHT STRUGGLING TO DROP BELOW THE MID TO UPPER 60S. && .LONG TERM /TUESDAY THROUGH FRIDAY/... IN THE EXTENDED...THE 00Z MEDIUM GUIDANCE CONTINUES TO INDICATE A FASTER OVERALL PROGRESSION OF THE UPPER TROUGH AND ASSOCIATED COLD FRONT EARLY ON IN THE PERIOD...WITH THE MAIN FRONTAL PASSAGE NOW LOOKING TO OCCUR SOMETIME BETWEEN TUESDAY AND TUESDAY NIGHT. PLENTIFUL MOISTURE AND LIFT ASSOCIATED WITH THE FRONT WILL LEAD TO A CONTINUED LIKELIHOOD OF CONVECTION DURING THIS TIME FRAME...FOLLOWED BY A QUICKER WEST-TO-EAST RETURN TO DRIER WEATHER ON WEDNESDAY AS HIGH PRESSURE AND DRIER AIR BUILDS EAST FROM THE WESTERN AND CENTRAL GREAT LAKES. HAVE THEREFORE KEPT LIKELY POPS IN PLAY WITH THE FRONTAL PASSAGE USING A BLEND OF THE 00Z GFS/GEM/ECMWF FOR TIMING... FOLLOWED BY A FASTER AND MORE PRONOUNCED IMPROVING TREND LATER TUESDAY NIGHT AND WEDNESDAY. DURING THE REMAINDER OF THE PERIOD...THE AFOREMENTIONED AREA OF HIGH PRESSURE WILL BECOME ESTABLISHED ACROSS THE GREAT LAKES IN THE WAKE OF THE FRONT...WHICH MAY HAVE A TENDENCY TO SLOW DOWN AND POSSIBLY STALL AS IT REACHES THE MID ATLANTIC COAST AND NEW ENGLAND STATES. WHILE IT IS POSSIBLE THAT LINGERING MOISTURE AND WEAK LIFT IN THE VICINITY OF THIS BOUNDARY COULD BE ENOUGH TO POP SOME ISOLATED CONVECTION ACROSS OUR FAR EASTERN ZONES BOTH THURSDAY AND FRIDAY... FOR NOW WILL INDICATE A MAINLY DRY FORECAST WITH LOW-LEVEL RIDGING EXPECTED TO BE THE DOMINANT WEATHER FEATURE. OVERALL...EXPECT FAIR AND MORE COMFORTABLE CONDITIONS TO BE THE GENERAL RULE LATER IN THE WEEK...WITH 850 MB TEMPS OF +10C TO +14C SUPPORTING HIGHS IN THE MID 70S TO NEAR 80 BOTH THURSDAY AND FRIDAY. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... OUTSIDE OF SHOWERS...EXPECT VFR CONDITIONS TODAY AND TONIGHT. FORECAST SOUNDINGS CONTINUE TO SUGGEST FAIRLY DRY AIR BELOW 5000 FEET...WHICH SHOULD HELP KEEP CIGS UP IN VFR TERRITORY. THIS SAID..SHOWERS AND POSSIBLY THUNDERSTORMS MAY TEMPORALLY LOWER VSBY BELOW 5SM IN RAIN. A CONSENSUS OF MODEL GUIDANCE BRINGS A CLUSTER OF SHOWERS WITH EMBEDDED THUNDERSTORMS ACROSS WESTERN NEW YORK THROUGH 15Z...WITH THIS POTENTIALLY IMPACTING BUF/IAG/ROC. SHOWERS WITH ISOLATED TSTMS SHOULD THEN BECOME SCATTERED IN NATURE THIS AFTERNOON...GENERALLY FOCUSED ALONG A FRONTAL BOUNDARY WHICH SHOULD BE STALLED ACROSS CENTRAL NEW YORK NEAR ROC. ALL ACTIVITY SHOULD TAPER OFF THIS EVENING WITH THE LOSS OF DAYTIME HEATING. OUTLOOK... SUNDAY AND MONDAY...VFR. TUESDAY...MVFR SHOWERS/THUNDERSTORMS LIKELY. WEDNESDAY...MAINLY VFR. CHC SHOWERS. && .MARINE... WINDS SHOULD REMAIN ON THE LIGHT SIDE THROUGH EARLY NEXT WEEK. THE FAIRLY LIGHT FLOW WILL ALLOW LAKE BREEZE INFLUENCES TO TAKE OVER DURING THE AFTERNOON. A FRONT WILL CROSS THE WATERS ON TUESDAY...LIKELY BRINGING SHOWERS AND PERHAPS A THUNDERSTORM. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...APFFEL NEAR TERM...APFFEL SHORT TERM...JJR LONG TERM...JJR AVIATION...APFFEL MARINE...APFFEL
AREA FORECAST DISCUSSION
NWS BUFFALO NY
326 AM EDT SAT JUN 9 2012 .SYNOPSIS... A WARM FRONT WILL LIFT ACROSS THE REGION TODAY...BRINGING ANOTHER ROUND OF SHOWERS AND POSSIBLY A THUNDERSTORM. FOLLOWING THE FRONT WILL BE A FLOW OF INCREASINGLY WARMER AND MORE MOIST AIR WHICH WILL LAST INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... IN GENERAL TERMS...A WARM FRONT WILL VERY GRADUALLY LIFT ACROSS THE REGION TODAY AND TONIGHT. FOR NOW...THE BOUNDARY IS QUITE DIFFUSE AT THE SURFACE...AND IS EASIER IDENTIFIED LOOKING AT 850 MB TEMPERATURE GRADIENT RATHER THAN SURFACE FEATURES. AT 300 AM THIS BOUNDARY EXTENDED ACROSS THE GREAT LAKES FROM LAKE SUPERIOR TO LAKE ONTARIO. THIS BOUNDARY WILL BE THE FOCUS OF SHOWERS AND THUNDERSTORM ACTIVITY...WITH AN AREA OF SHOWERS AND A FEW THUNDERSTORMS CROSSING LAKE HURON DURING THE EARLY MORNING HOURS. A CONSENSUS OF BOTH 00Z MODEL RUNS OF THE GFS/RGEM/NAM ARE GENERALLY FASTER WITH THE ONSET OF SHOWERS...ALL GENERALLY KEYING ON THIS UPSTREAM CONVECTION. THIS GUIDANCE...WHICH IS CONSISTENT WITH RECENT HRRR RUNS WOULD BRING THIS ACROSS THE CWA BETWEEN 600 AM AND NOON. EXTRAPOLATING THIS YIELDS A SIMILAR TIMING...BUT IT WOULD BE FURTHER SOUTH THAN MODEL GUIDANCE. GIVEN THE POSITION AND GENERAL NORTHWARD PROGRESSION OF THE FRONT...FEEL THE MODEL GUIDANCE IS REASONABLE IN FORECASTING A NORTHWARD JOG IN THIS. A PERIOD OF SHOWERS IS LIKELY IN MOST LOCATIONS...WITH PERHAPS A THUNDERSTORM. FAR SOUTHERN (SOUTHERN TIER) AND NORTHERN (EAST OF LAKE ONTARIO) PORTIONS OF THE CWA HAVE THE BEST CHANCE TO DODGE THE SHOWERS THIS MORNING. THE SEVERE WEATHER THREAT APPEARS MINIMAL WITH THIS...GIVEN THE MORNING TIMING...AND LACK OF A STRONG SHORTWAVE. THIS WAVE WILL LIKELY EXIT TO THE EAST OF THE CWA EITHER LATE MORNING OR EARLY AFTERNOON...WITH A PARTIAL CLEARING POSSIBLE. THERE STILL MAY BE SOME DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS...ESPECIALLY IN THE VICINITY OF THE FRONT...WHICH SHOULD BE STALLED FROM TORONTO-ROCHESTER-BINGHAMTON. AWAY FROM THE BOUNDARY STANDS A DECENT CHANCE FOR FAIR WEATHER THIS AFTERNOON...OUTSIDE OF A STRAY SHOWER. TEMPERATURES WILL ALSO WARM TODAY...ESPECIALLY SOUTH OF THE BOUNDARY WHERE HIGHS WILL LIKELY APPROACH OR TOP 80. FOR TONIGHT...THE FRONT WILL CONTINUE ITS SLOW NORTHWARD PROGRESSION. THE FOCUS FOR SHOWERS WILL LIFT WITH IT...THOUGH SHOWERS ACTIVITY SHOULD DIMINISH WITH THE LOSS OF DAYTIME HEATING...EVENTUALLY TAPERING OFF TOWARD DAYBREAK SUNDAY MORNING. LOWS WILL BE ON THE WARM SIDE..ONLY DROPPING INTO THE UPPER 50S TO LOWER 60S. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... ON SUNDAY...STRONG RIDGING ALOFT WILL BUILD ACROSS THE REGION FOLLOWING THE DEPARTURE OF THE WARM FRONT...WHICH WILL MOVE FROM OUR FAR EASTERN ZONES INTO EASTERN NEW YORK AND NEW ENGLAND THROUGH THE DAY. STRONG SUBSIDENCE ASSOCIATED WITH THE BUILDING UPPER RIDGE WILL BY AND LARGE LEAD TO A MAINLY DRY DAY ALONG WITH A CONSIDERABLE AMOUNT OF SUNSHINE...THOUGH A FEW ISOLATED SHOWERS STILL CANNOT BE TOTALLY RULED OUT ALONG THE DEPARTING WARM FRONT IN THE MORNING... AND ACROSS THE HIGHER TERRAIN OF THE FAR INTERIOR SOUTHERN TIER AND FINGER LAKES IN THE AFTERNOON. 850 MB TEMPS WARMING TO +14C TO +16C WILL BE SUPPORTIVE OF WIDESPREAD HIGHS IN THE LOWER TO MID 80S... WHILE HUMIDITY LEVELS REMAIN AT MODEST LEVELS WITH DEWPOINTS LINGERING IN THE UPPER 50S TO LOWER 60S. DURING THE COURSE OF SUNDAY NIGHT AND MONDAY...THE AXIS OF THE STRONG UPPER RIDGE WILL EVER SO SLOWLY DRIFT EAST INTO NEW ENGLAND. CONTINUED LARGE-SCALE SUBSIDENCE ASSOCIATED WITH THIS FEATURE WILL MAINTAIN DRY WEATHER THROUGH SUNDAY NIGHT AND THE FIRST HALF OF MONDAY...WITH MIDSUMMERLIKE HEAT CONTINUING. WITH A SOUTHERLY RETURN FLOW DEVELOPING AT THE LOW LEVELS AND SURFACE DEWPOINTS ON A SLOW BUT STEADY RISE...EXPECT MOST LOCATIONS TO EXPERIENCE OVERNIGHT LOWS IN THE LOWER TO MID 60S SUNDAY NIGHT. MONDAY STILL LOOKS TO BE THE HOTTEST DAY OF THE UPCOMING WEEK...WHEN 850 MB TEMPS OF +16C TO +18C WILL SUPPORT WIDESPREAD MAX TEMPS IN THE MID TO UPPER 80S...WITH SOME OF OUR USUAL WARM SPOTS IN THE GENESEE VALLEY AND FINGER LAKES POTENTIALLY REACHING THE 90 DEGREE MARK. COUPLED WITH DEWPOINTS RISING INTO THE MID 60S...THESE TEMPERATURES WILL MAKE FOR FAIRLY UNCOMFORTABLE CONDITIONS BY MONDAY AFTERNOON. LATER MONDAY AND ESPECIALLY MONDAY NIGHT...A FAIRLY IMPRESSIVE UPPER-LEVEL TROUGH AND ASSOCIATED COLD FRONT WILL WORK EAST INTO THE GREAT LAKES FROM THE NORTHERN PLAINS STATES AND CENTRAL CANADA. AT THE SURFACE...A DEVELOPING SURFACE WAVE OVER THE TENNESEE VALLEY WILL STRENGTHEN AS IT LIFTS NORTHWARD ALONG THE ADVANCING COLD FRONT...HELPING TO TRANSPORT INCREASING AMOUNTS OF LIFT AND MOISTURE NORTHWARD FROM THE WIDE-OPEN GULF OF MEXICO. THIS WILL LEAD TO AN INCREASING POTENTIAL FOR CONVECTION FROM LATER MONDAY THROUGH MONDAY NIGHT...WITH THE 00Z GUIDANCE SUITE CONTINUING TO SUPPORT A FASTER ARRIVAL OF THIS SYSTEM AND ITS ASSOCIATED CONVECTION...POSSIBLY AS EARLY AS LATE MONDAY AFTERNOON/EARLY MONDAY EVENING ACROSS FAR WESTERN NEW YORK PER A CONSENUS OF THE NAM/GFS/GEM. WILL THEREFORE BEGIN CHANCE POPS ACROSS FAR WESTERN NEW YORK DURING THIS TIME FRAME...BEFORE SPREADING THESE EASTWARD ACROSS THE REMAINDER OF THE AREA MONDAY NIGHT. OTHERWISE...WARM AND MUGGY CONDITIONS WILL CONTINUE...WITH OVERNIGHT LOWS MONDAY NIGHT STRUGGLING TO DROP BELOW THE MID TO UPPER 60S. && .LONG TERM /TUESDAY THROUGH FRIDAY/... IN THE EXTENDED...THE 00Z MEDIUM GUIDANCE CONTINUES TO INDICATE A FASTER OVERALL PROGRESSION OF THE UPPER TROUGH AND ASSOCIATED COLD FRONT EARLY ON IN THE PERIOD...WITH THE MAIN FRONTAL PASSAGE NOW LOOKING TO OCCUR SOMETIME BETWEEN TUESDAY AND TUESDAY NIGHT. PLENTIFUL MOISTURE AND LIFT ASSOCIATED WITH THE FRONT WILL LEAD TO A CONTINUED LIKELIHOOD OF CONVECTION DURING THIS TIME FRAME...FOLLOWED BY A QUICKER WEST-TO-EAST RETURN TO DRIER WEATHER ON WEDNESDAY AS HIGH PRESSURE AND DRIER AIR BUILDS EAST FROM THE WESTERN AND CENTRAL GREAT LAKES. HAVE THEREFORE KEPT LIKELY POPS IN PLAY WITH THE FRONTAL PASSAGE USING A BLEND OF THE 00Z GFS/GEM/ECMWF FOR TIMING... FOLLOWED BY A FASTER AND MORE PRONOUNCED IMPROVING TREND LATER TUESDAY NIGHT AND WEDNESDAY. DURING THE REMAINDER OF THE PERIOD...THE AFOREMENTIONED AREA OF HIGH PRESSURE WILL BECOME ESTABLISHED ACROSS THE GREAT LAKES IN THE WAKE OF THE FRONT...WHICH MAY HAVE A TENDENCY TO SLOW DOWN AND POSSIBLY STALL AS IT REACHES THE MID ATLANTIC COAST AND NEW ENGLAND STATES. WHILE IT IS POSSIBLE THAT LINGERING MOISTURE AND WEAK LIFT IN THE VICINITY OF THIS BOUNDARY COULD BE ENOUGH TO POP SOME ISOLATED CONVECTION ACROSS OUR FAR EASTERN ZONES BOTH THURSDAY AND FRIDAY... FOR NOW WILL INDICATE A MAINLY DRY FORECAST WITH LOW-LEVEL RIDGING EXPECTED TO BE THE DOMINANT WEATHER FEATURE. OVERALL...EXPECT FAIR AND MORE COMFORTABLE CONDITIONS TO BE THE GENERAL RULE LATER IN THE WEEK...WITH 850 MB TEMPS OF +10C TO +14C SUPPORTING HIGHS IN THE MID 70S TO NEAR 80 BOTH THURSDAY AND FRIDAY. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... OUTSIDE OF SHOWERS...EXPECT VFR CONDITIONS THROUGH THIS EVENING. BOTH OBSERVED AND FORECAST SOUNDINGS SHOW FAIRLY DRY AIR BELOW 5000 FEET...WHICH SHOULD HELP KEEP CIGS UP IN VFR TERRITORY. THIS SAID..SHOWERS AND POSSIBLY THUNDERSTORMS MAY TEMPORALLY LOWER VSBY BELOW 5SM IN RAIN. A CONSENSUS OF MODEL GUIDANCE BRINGS A CLUSTER OF SHOWERS WITH EMBEDDED THUNDERSTORMS ACROSS WESTERN NEW YORK BETWEEN 09Z AND 15Z...WITH THIS POTENTIALLY IMPACTING BUF/IAG/ROC. SHOWERS WITH ISOLATED TSTMS SHOULD THEN BECOME SCATTERED IN NATURE THIS AFTERNOON...GENERALLY FOCUSED ALONG A FRONTAL BOUNDARY WHICH SHOULD BE STALLED ACROSS CENTRAL NEW YORK NEAR ROC. ALL ACTIVITY SHOULD TAPER OFF THIS EVENING WITH THE LOSS OF DAYTIME HEATING. OUTLOOK... SUNDAY AND MONDAY...VFR. TUESDAY...MVFR SHOWERS/THUNDERSTORMS LIKELY. WEDNESDAY...MAINLY VFR. CHC SHOWERS. && .MARINE... WINDS SHOULD REMAIN ON THE LIGHT SIDE THROUGH EARLY NEXT WEEK. THE FAIRLY LIGHT FLOW WILL ALLOW LAKE BREEZE INFLUENCES TO TAKE OVER DURING THE AFTERNOON. A FRONT WILL CROSS THE WATERS ON TUESDAY...LIKELY BRINGING SHOWERS AND PERHAPS A THUNDERSTORM. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...APFFEL NEAR TERM...APFFEL SHORT TERM...JJR LONG TERM...JJR AVIATION...APFFEL MARINE...APFFEL
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
151 AM EDT SAT JUN 9 2012 .SYNOPSIS... A WARM FRONT WILL MOVE INTO THE AREA ON SATURDAY WITH THE LIKELIHOOD OF SHOWERS AND THUNDERSTORMS. THIS WEAKENING BOUNDARY MAY HELP TRIGGER ISOLATED SHOWERS AND THUNDERSTORMS ON SUNDAY...BUT MOST OF THE AREA WILL SEE FAIR WEATHER AND WARM TEMPERATURES SUNDAY INTO MONDAY. A CHANCE FOR MORE SHOWERS AND THUNDERSTORMS WILL RETURN MONDAY NIGHT INTO TUESDAY. && .NEAR TERM /THROUGH TODAY/... 1000 PM UPDATE....SHOWERS FROM EARLY THIS EVENING HAVE DIED DOWN ASIDE FROM A LINGERING SPRINKLE OR TWO. AN AREA OF SHOWERS OVER LAKE HURON NOW IS FORECASTED BY ALL MODEL GUIDANCE TO DIVE SOUTHEAST OVERNIGHT. TIMING OF PRECIPITATION STILL LOOKS TO BE IN THE 08Z TO 12Z TIME FRAME FROM THE NORTHERN TIER OF PA NORTHWEST INTO CNY. THE NEW RUNS OF THE HRRR AND 0Z NAM 12 HAVE SHIFTED FARTHER NORTH A BIT WITH THE BETTER CHANCES FOR SHOWERS...WITH THE FOCUS ACROSS CNY VS THE SOUTHERN TIER OF NY. STILL THINKING THE MODELS MAY BE A BIT TOO FAR NORTH WITH THIS SYSTEM GIVEN THESE SYSTEMS TO DIVE FARTHER SOUTH TOWARD THE MORE UNSTABLE AIR. 630 PM UPDATE...MAIN ACTION CONTINUES TO BE NORTHEAST OF OUR AREA WITH A STRONG SHORT WAVE OVER SOUTHERN QUEBEC AND NNY BEING IN THE LEFT EXIT REGION OF THE UPPER LEVEL JET. CLOSER TO HOME SOME ISOLATED SHOWERS CONTINUE MAINLY EAST OF 81 NOW WITH JUST A FEW STRIKES OF LIGHTING. WITH THE MAIN UPPER LEVEL ENERGY STAYING TO OUR NORTHEAST...WILL MAINTAIN JUST ISOLATED T-STORMS FOR THIS EVENING THEN DRY PAST EARLY THIS EVENING. ISOLD CONVECTION MAINLY ACRS THE SRN TIER AND NE PA IS XPCTD TO DIE OFF THIS EVNG. LATER TNGT...MCS WILL LIKELY MAKE ITS WAY SEWD FROM ONTARIO. GFS CONSIDERABLY FASTER THAN OTHER MDLS...BUT GEM AND NAM SUGGEST PCPN WILL BE ON OUR DOORSTEP BY 10-12Z. RETAINED CHC/LIKELY POPS FOR TMRW WITH THIS SYSTEM. FCST BCMS VERY INTERESTING TMRW AFTN. BOTH NAM/GFS SHOW A NW-SE CORRIDOR ACRS THE BGM CWA WHICH WILL BE FVRBL FOR POTNL SVR DVLPMNT. AS EXPECTED...THE NAM VALUES ARE HIGHER AND ACTUALLY QUITE IMPRSV FOR THIS AREA IN TERMS OF EHI AND COMPOSITE SVR PARAMS. GFS VALUES ARE LOWER (NOT SUPRISING) AND PLACE AXIS OF GREATEST POTNL SLIGHTLY FURTHER W OF THE NAM. WE NOTE THAT MCS`S OFTEN DELAY THE ADVANCEMNT OF THE WMFNT SO THE GFS MAY BE ONTO SOMETHING. IN ANY EVENT...IF WRN ZONES BREAK OUT INTO SOME SUNSHINE SAT AFTN AIDING DESTABLIZATION...THERE WILL BE THE POTNL FOR STRONG/SVR TSRA ALONG/NEAR THE WMFNT MID TO LATE AFTN. BEST GUESS ATTM IS GREATEST POTNL WOULD BE ACRS AREAS GNRLY ALONG AND WEST OF I-81. LOTS OF UNCERTAINTY TMRW. FOR NOW WE HAVE ADDED SOME ENHANCMENT TO THE TSRA GRIDS ACRS WRN ZONES FOR TMRW AFTN..AND WILL MENTION POTNL IN THE HWO. MAX TEMPS VERY TRICKY TMRW WITH THE WMFNT...AND I COULD SEE A SCENARIO WHERE MAXES ACRS THE EAST (U60S/L70S) ARE TOO WARM WHILE MAXES WEST OF THE WMFNT (M/U70S) ARE TOO COOL. && .SHORT TERM /TONIGHT THROUGH MONDAY/... LINGERING CONVECTION XPCTD SAT NGT VCNTY OF THE WMFNT. THIS WEAKENING BOUNDARY...WITH SOME OROGRAPHIC HELP...COULD HELP TRIGGER SOME ISOLD CONVECTION ON SUNDAY...BUT MOST AREA SWILL JUST HAVE PARTLY/MOSTLY SUNNY DAY WITH WARM TEMPS. EVEN WARMER ON MONDAY AHEAD OF THE NXT SYSTEM WITH SOME AREAS APRCHNG 90. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... UPR RDG SLIDES TO THE EAST MON ALLOWING A LRG TROF TO SETTLE INTO THE NRN LAKES. GNRL LWRG OF HGTS AHD OF THE SFC FNT COMBINED WITH AN INFLUX OF GULF MOISTURE WILL TRIGGER SCT SHWRS AND TRWS ON TUE THEN CONTG THRU THE PD AS TROF SLOWLY MVES EAST. SOME IMPRVMT PSBL LATE IN THE PD...AS A WEAK HI MVES IN...BUT OVERALL PTRN STILL HAS THE AREA IN A BROAD TROF THRU THE WEEK. FOR THE PD...ONCE AGAIN FLWD HPC GUID WHICH WAS IN RSNBL AGREEMENT WITH MODEL MOS GUID. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... VFR IS EXPECTED TO PREVAIL FOR MOST OF THIS FORECAST PERIOD WITH A COUPLE TIMES OF EXCEPTION. AN UPPER LEVEL DISTURBANCE WILL RACE ACROSS THE UPPER GREAT LAKES EARLY THIS MORNING AND SLIDE ACROSS NY AND NORTHERN PA WITH WIDESPREAD SHOWERS AND CIGS LOWERING TO BETWEEN FL050-100. POCKETS OF ENHANCED SHOWER ACTIVITY COULD CREATE BRIEF MVFR CIGS AND VSBYS DURING THE 10Z-15Z PERIOD. WITH THE PASSAGE OF THE UPPER WAVE OVERCAST CIGS ARE FORECAST TO DISSIPATE TO SCT-BKN AFT 16Z. MODELS THEN SUGGEST INCREASING LOW LEVEL INSTABILITY DUE TO THE DAYTIME HEATING AND POOLING MOISTURE ALONG A STALLING FRONTAL BOUNDARY ACROSS THE SOUTHWEST PORTION OF NEW YORK AND NORTH CENTRAL PA. THIS WILL CREATE AN ENVIRONMENT FAVORABLE FOR A SCATTERED CONVECTIVE THREAT DURING MAINLY THE 18Z-00Z TIME FRAME...ALTHOUGH WITH A SECONDARY UPPER DISTURBANCE SUGGESTED BY OUR COMPUTER MODELS TO DROP INTO THE REGION THIS EVENING...SOME ISOLD ACTIVITY COULD CONTINUE AFTER DARK AND THROUGH 06Z...ESPECIALLY IN THE VCNTY OF KELM-KBGM-KAVP. NOT ENOUGH CONFIDENCE TO INCLUDE A PROB FORECAST AFT 00Z TONIGHT...BUT DO HAVE MENTION OF A RISK OF TSRA ACTIVITY AFFECTING TERMINAL OPS THIS AFTERNOON. OUTLOOK... SAT NGT...CHC MVFR IN ISOLD-SCT TSRA SUN/MON...MAINLY VFR...BUT VLY FOG PSBL EACH MRNG. TUE...VFR GIVING WAY TO MVFR IN SCT TSRA WED...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS... NEAR TERM...HEDEN SHORT TERM... LONG TERM...DGM AVIATION...JAB
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
950 AM CDT SAT JUN 9 2012 .DISCUSSION...FORECAST CHALLENGE FOR UPDATE WILL BE STORM CHANCES AND TEMPERATURES. CLUSTER OF STORMS CONTINUES OVER FAR NE ND INTO NW TIP OF MN. OVERALL GRADUAL WEAKENING EXPECTED TO CONTINUE HOWEVER DID EXPAND POPS EASTWARD REMAINDER OF MORNING INTO NW MN BASED ON CURRENT TRENDS. KEEP THINKING OF POTENTIAL FOR SOME REDEVELOPMENT LATE AFTERNOON VCNTY SURFACE LOW FROM RUC ACROSS NW FA HOWEVER CIN SHOULD BUILD/CONTINUE ACROSS REMAINDER OF FA IN WARM SECTOR AND WILL KEEP DRY. CLOUDS WILL HOLD IN A LITTLE LONGER ACROSS FAR NORTH WITH CURRENT STORM ACTIVITY AND AS A RESULT LOWERED MAXIMUM TEMPERATURES A FEW DEGREES AND INCREASED CLOUDS ALONG INTERNATIONAL BORDER AREA. && .AVIATION...VFR CONDITIONS ARE EXPECTED WITH INCREASING SOUTHERLY WINDS TODAY...GUSTING TO 30KT AT TIMES BY AFTERNOON. CURRENT STORM COVERAGE SHOULD REMAIN NORTHER OF FORECAST TAF SITES. SLIGHT CHANCE SOME DEVELOPMENT COULD TAKE PLACE VCNTY DVL LATE THIS AFTERNOON. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ VOELKER
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
302 PM MDT SAT JUN 9 2012 .DISCUSSION...CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER CENTRAL ND...WITH SLOW MOVING OR NEARLY STATIONARY COLD FRONT STRETCHING SOUTH-SOUTHWESTWARD INTO CENTRAL SD AND WESTERN NEB. UPPER LEVEL ANALYSIS SHOWS LOW OVER SOUTHWEST ALBERTA...WITH STRONG JET WRAPPING AROUND THE SYSTEM FROM THE OREGON COAST TO WESTERN WY AND EASTERN MT. REGIONAL RADARS SHOWING BAND OF SHOWERS AND SOME THUNDER...ASSOCIATED WITH UPPER JET...CROSSING NORTH CENTRAL WY INTO PARTS OF SOUTHEASTERN MT. STORMS ARE BEGINNING TO DEVELOP FURTHER WEST OVER THE ROCKIES. BRISK NORTH- NORTHWEST WINDS CONTINUE BEHIND THE FRONT ACROSS PORTIONS OF THE WESTERN SD PLAINS...WITH BREEZY SOUTHERLY WINDS AHEAD OF THE FRONT ACROSS FAR SOUTH CENTRAL SD. SKIES ARE MOSTLY SUNNY WITH TEMPS RANGING FROM THE 70S OVER NORTHEASTERN WY AND THE BLACK HILLS TO THE MID 90S OVER PORTIONS OF SOUTH CENTRAL SD. AS UPPER LOW MOVES EAST ALONG THE CANADIAN/MONTANA BORDER TONIGHT...STRONG UPPER LEVEL JET ENERGY WILL MOVE NORTHEAST ACROSS THE NORTHERN PLAINS TONIGHT. THIS WILL BRING A GOOD CHANCE OF SHOWERS AND STORMS TO MUCH OF THE AREA...ESPECIALLY NORTHEASTERN WY...THE BLACK HILLS...AND NORTHWESTERN SD. CHANCES FOR PCPN WILL DECREASE FURTHER TO THE SOUTH AND EAST...BUT THREAT FOR SEVERE STORMS WILL LIKELY BE HIGHER IN THIS AREA TONIGHT...ESPECIALLY TOWARD SOUTH CENTRAL SD. CAPE VALUES OF UP TO 3000 J/KG ARE PROGGED FOR SOUTH CENTRAL SD THIS EVENING WITH SHEAR INCREASING DUE TO STRENGTHENING LOW LEVEL JET. MAIN THREATS FROM ANY SEVERE STORMS WILL BE LARGE HAIL AND STRONG WIND GUSTS. A TIGHT PRESSURE GRADIENT WILL DEVELOP OVERNIGHT ACROSS WESTERN SD AS MAIN COLD FRONT FINALLY PUSHES EAST OF THE CWA AND SECONDARY SURGE OF COOLER AIR BEGINS TO MOVE IN. SHORT RANGE MODELS DISAGREE SOME ON POTENTIAL STRENGTH OF WINDS OVERNIGHT. NAM AND RUC ARE STRONGEST WITH THE WINDS...SHOWING POTENTIAL FOR A BRIEF PERIOD OF WARNING CRITERIA WINDS OVER THE RAP AREA AND ADJACENT PLAINS. HAVE DECIDED TO ISSUE A WIND ADVISORY FOR MUCH OF THE NORTHWESTERN AND WEST CENTRAL PLAINS. WINDS SHOULD BEGIN TO DIMINISH SOME LATE TONIGHT OR EARLY SUNDAY. BREEZY TO WINDY CONDITIONS WILL LINGER INTO SUNDAY ACROSS MUCH OF THE AREA...WITH COOLER AND DRIER AIR IN PLACE. WILL KEEP CHANCES FOR A FEW SHOWERS ACROSS NORTHERN PORTIONS OF THE AREA AS UPPER LOW PASSES TO THE NORTH. HIGHS WILL BE IN THE 60S TO MID 70S WITH PARTLY CLOUDY TO MOSTLY SUNNY SKIES. SUNDAY NIGHT WILL BE PLEASANTLY COOL...WITH LOWS IN THE 40S AND LOWER 50S. SEASONABLY MILD AND BREEZY WEATHER WILL CONTINUE ON MONDAY...WITH HIGHS IN THE UPPER 60S AND 70S FOR MOST AREAS. NORTHWESTERLY FLOW ALOFT WILL BRING SOME WEAK UPPER LEVEL ENERGY ACROSS NORTHERN AND WESTERN PORTIONS OF THE CWA...SO WILL KEEP SOME LOW CHANCE POPS FOR SHOWERS AND POSSIBLY A THUNDERSTORM OR TWO DURING THE DAY. EXTENDED...MAINLY ZONAL FLOW WITH A BUILDING THERMAL RIDGE WILL RESULT IN A DAILY CHANCE FOR TSTMS ALONG WITH WARMING TEMPS THROUGH MID WEEK. SW FLOW ALOFT WILL DEVELOP FOR THE END OF THE WEEK AS A DEEP UPPER TROF MOVES THROUGH THE WRN CONUS. THIS MAY LEAD TO INCREASED CHANCE FOR TSTMS...WITH TEMPS STAYING QUITE WARM. && .AVIATION...18Z TAFS UPDATE VFR CONDITIONS EXPECTED MOST OF THE AFTN. SHRA/TSTMS EXPECTED TO DEVELOP ACROSS NERN WY AND THE BLKHLS LATE THIS AFTN...WITH ACTIVITY SPREADING ONTO THE PLAINS OF NWRN SD THIS EVENING. MAINLY VFR CONDITIONS EXPECTED...WITH AREAS OF IFR IN HEAVIER ACTIVITY. A SECONDARY COLD FRONT WILL MOVE THROUGH THE REGION LATER THIS EVENING AND OVERNIGHT BRINGING A PERIOD OF STRONG NW WINDS. GUSTS OVER 40KTS POSSIBLE ACROSS NWRN SD...WITH THE STRONGEST WINDS ALONG THE ERN SLOPES OF THE BLKHLS INCLUDING THE KRAP TERMINAL. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...WIND ADVISORY FROM 9 PM THIS EVENING TO 6 AM MDT SUNDAY FOR BUTTE-CUSTER CO PLAINS-HERMOSA FOOT HILLS-NORTHERN MEADE CO PLAINS-PENNINGTON CO PLAINS-RAPID CITY-SOUTHERN MEADE CO PLAINS-STURGIS/PIEDMONT FOOT HILLS. WY...NONE. && $$ SHORT TERM...26 LONG TERM....JOHNSON AVIATION...JOHNSON
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
846 PM CDT SUN JUN 10 2012 .UPDATE... LATEST IR SAT AND RUC13 DATA SHOWS THE UPPER LEVEL LOW MOVING SLOWLY NE TOWARDS MIDDLE TN THIS EVENING FROM NEAR COLUMBUS MS. WITH THE LOSS OF HEATING SHOWERS AND THUNDERSTORMS ARE STARTING TO DECLINE IN COVERAGE ACROSS THE REGION. HAVE LOWERED POPS THROUGH 06Z WITH JUST ISOLATED TO SCTD SHWRS AND TSTORMS IN THE EASTERN PORTIONS OF THE FORECAST AREA OVERNIGHT INTO THE MORNING AT BEST. HIGH CONFIDENCE THAT ONLY A FEW SPOTS WILL EVEN SEE THIS ACTIVITY. TWEAKED TEMPS AND DEWPTS TO MATCH CURRENT READINGS WITH FORECAST LOWS LOOKING GOOD AT THIS POINT. --ABS && .PREV DISCUSSION... /ISSUED 614 PM CDT SUN JUN 10 2012/ UPDATE... UPDATED TO INCLUDE 00Z AVIATION DISCUSSION BELOW. JCL DISCUSSION... /ISSUED 251 PM CDT SUN JUN 10 2012/ INSTABILITY IS IN PLACE...HOWEVER WEAK LOW LEVEL CONVERGENCE HAS BEEN HINDERING CONVECTION...AND A FEW SHOWERS THAT HAVE DEVELOPED HAVE BEEN LIGHT...WITH THE EXCEPTION OF NORTHEAST MISSISSIPPI. NOT CONFIDENT WITH THE 12Z MODELS THAT A QUARTER TO A HALF INCH IN QPF AMOUNTS WILL OVERSPREAD THE MIDSOUTH THROUGH 11/00Z. THEY MAY RECEIVE THAT AMOUNT ACROSS PORTIONS OF NORTHEAST MISSISSIPPI BUT THAT`S ALL. THIS AREA WILL ALSO BE FAVORED FOR AN OCCASIONAL CLAP OF THUNDER...BUT STRONG STORMS SEEMS UNLIKELY. MOST MIDSOUTHERNERS HOWEVER WILL BE LUCKY TO SEE A FEW HUNDREDTHS OF AN INCH. BY SUNSET ANY LINGERING SHOWERS SHOULD BEGIN TO QUICKLY DISSIPATE...WITH DRY CONDITIONS EXPECTED FOR MOST OF THE AREA. ONLY THE FAR EASTERN COUNTIES MAY CONTINUE TO SEE SCATTERED SHOWER ACTIVITY. MOSTLY CLOUDY TO CLOUDY SKIES WILL BE THE RULE AREA WIDE...KEEPING LOW TEMPERATURES A DEGREE OR TWO WARMER THEN LAST NIGHT. MONDAY AND TUESDAY...THE LOW PRESSURE DISTURBANCE CURRENTLY OVER THE MIDSOUTH WILL SLOWLY TRACK EAST THROUGH THE VOLUNTEER STATE AS A MAJOR SHORTWAVE IN THE MAIN JET FLOW CROSSES THE NORTHERN PLAINS AND UPPER MIDWEST. THIS ENERGY WILL SEND A COLD FRONT SOUTHEAST THROUGH THE MID MISSISSIPPI VALLEY MONDAY AFTERNOON. PORTIONS OF THE MIDSOUTH WEST OF THE RIVER ARE ZONED FOR A SLIGHT RISK OF SEVERE WEATHER MONDAY EVENING AND OVERNIGHT AS THE TAIL END OF THE FRONT CROSSES THE OZARKS. LIFTED INDICES NEAR -10C ARE PROGGED FOR LATE TOMORROW AND NEARLY THAT ACROSS NORTH MISSISSIPPI BY MIDDAY TUESDAY AS THE FRONT PUSHES SOUTH. WILL LIKELY REMOVE ANY WORDING FOR A STRONG STORM FOR THIS AFTERNOON WITH THE DISTURBANCE...BUT KEEP MENTION OF SEVERE IN TOMORROW AND TUESDAY. FORECAST HIGHS A BIT TRICKY FOR MONDAY AS LOW LEVEL CLOUD COVER MAY BE ABUNDANT IN THE MORNING HOURS. HAVE LEANED TOWARD THE EURO AND NAM WITH SLIGHTLY COOLER HIGHS. SAME SITUATION ON TUESDAY AS CONVECTION WILL BE ONGOING OVER PORTIONS OF THE AREA. WEDNESDAY THROUGH THURSDAY...MODELS SHOW THE REGION ON THE SOUTH SIDE OF SURFACE HIGH PRESSURE WITH DRIER DEWPOINTS USHERING IN ON NORTHEAST BREEZES. TEMPERATURES WILL BE NEAR AVERAGE FOR MID JUNE...WITH ONLY A SLIGHT CHANCE OF AFTERNOON CONVECTION OVER THE EXTREME SOUTHERN COUNTIES...WHERE DEWPOINTS IN THE MID 60S WILL STILL BE FOUND. NEXT WEEKEND...SOUTHERLY WINDS WILL BRING HIGHER HUMIDITY BACK TO THE MIDSOUTH WITH ISOLATED SUMMERTIME AFTERNOON CONVECTION. HIGH TEMPERATURES WILL WARM SLIGHTLY. JAB AVIATION... 00Z TAF CYCLE (11/00Z-12/00Z) SCATTERED TO NUMEROUS SHOWERS WILL CONTINUE UNTIL ABOUT 02Z MAINLY FROM NORTHEAST MS INTO SOUTHWEST TN POSSIBLY AFFECTING KMKL AND KTUP. CONDITIONS MAY LOWER TO MVFR IN THE HEAVIER SHOWERS. OTHERWISE MOSTLY VFR CONDITIONS ARE EXPECTED THIS EVENING AT THE TAF SITES. AFTER 05Z...IFR CONDITIONS DEVELOPING AT KMKL AND KTUP WITH LOWERING CEILINGS AND FOG...MVFR CEILINGS DEVELOPING AT KMEM AND KJBR. CONDITIONS THEN GRADUALLY IMPROVING AFTER MID-MORNING MONDAY BECOMING VFR AFTER 18Z. CONFIDENCE IS TOO LOW TO MENTION TSRA IN THE TAFS FOR MONDAY AFTERNOON WITH UPPER LEVEL RIDGING TEMPORARILY SPREADING INTO THE AREA AS THE UPPER LEVEL TROUGH THAT HAS BEEN MOVING THROUGH THE LOWER MS RIVER VALLEY THE LAST COUPLE OF DAYS MOVES TO THE EAST. SE-S WINDS DECREASING TO 5 KTS OR LESS TONIGHT BECOMING SW 8-10 KTS MONDAY. JCL && .AVIATION... && .PRELIMINARY POINT TEMPS/POPS... MEM 72 89 73 87 / 20 30 50 40 MKL 68 87 69 86 / 30 40 50 40 JBR 70 89 69 86 / 20 30 50 20 TUP 70 87 72 87 / 30 40 50 50 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
621 PM CDT SUN JUN 10 2012 .UPDATE...ADDED AVIATION SECTION FOR 00Z TAF`S. && .AVIATION...BNA/CKV/CSV...UPPER TROUGH CONTINUES TO ROTATE SLOWLY ACROSS THE REGION THIS EVENING, WITH PRECIPITATION SLOW TO DEVELOP ACROSS MIDDLE TENNESSEE. BOTH THE WRF AND HRRR MODELS DO SHOW SIGNIFICANT DEVELOPMENT BY 01Z ACROSS PARTS OF THE MID STATE, BUT AM NOT EXPECTING WIDESPREAD HEAVY RAIN, AND ALSO BELIEVE ANY THUNDERSTORM ACTIVITY WILL BE ISOLATED. HAVE THEREFORE ONLY MENTIONED SHRA IN THE TAF`S. EXPECT CEILINGS TO DETERIORATE DURING THE EVENING AND OVERNIGHT AS THE BOUNDARY LAYER CONTINUES TO MOISTEN, WITH GRADUAL IMPROVEMENT DURING THE MORNING AS PRECIPITATION ENDS FROM WEST TO EAST. && .PREV DISCUSSION... /ISSUED 350 PM CDT SUN JUN 10 2012/ SHORT TERM (THRU TUE)... DEEP MOISTURE/CLOUDY SKIES WL REMAIN ACROSS MID-TN TNGT AS A SUB- TROPICAL LOW PRES SYSTEM STARTS TO LIFT NORTH. AREA RADARS AT MID AFTERNOON SHOW AN AREA OF RAIN MOVING NORTH ACROSS THE AL-TN LINE ATTM. EXPECT MOST OF THIS ACTIVITY TO HOLD TOGETHER WITH SCATTERED SHOWERS ALONG/SOUTH OF I-40 LATE AFTN-EARLY EVE. AS H5 TROF LIFTS NORTH LATER TNGT AND MORE SHOWERS ARE EXPECTED TO DEVELOP. LKLY POPS. MODELS SHOW DEEPER LIFT WITH MORE UNSTABLE AIR AT MID-LVLS. HOWEVER SFC LAYER REMAINS STABLE WITH A FEW THUNDERSTORMS POSSIBLE. ONE INCH RAINFALL EXPECTED IN THE SOUTH/SOUTHEAST. H5 TROF SHOULD BE EAST OF I-65 MONDAY MORNING WITH THE BULK OF PCPN SHIFTING EAST OF I-65...HEAVIER SHOWERS PATEAU. EXPECT TO SEE A BREAK IN PCPN MOST AREAS FROM MID MORNING ON...WITH AN AREA OF SHOWERS AND THUNDERSTORMS DEVELOPING FURTHER WEST ASSOCIATED WITH A COLD FRONT. THE COLD FRONT WL MOVE EAST AND DESTABILIZE THE ATMOSPHERE MON NIGHT. EXPECT OUR BEST CHANCE OF THUNDERSTORMS MON NIGHT AS COLD FRONT CUTS INTO THE REGION WITH MODEL SHOWALTERS TO -4. SHOWERS AND THUNDERSTORMS LKLY. MODELS PUSH THE COLD FRONT ACROSS MID TN TUE MORNING. DRIER AIR EXPECTED TO KEEP A SMALL CHANCE OF SHOWERS AND THUNDERSTORMS SOUTH AND PLATEAU. LONG TERM (WED-SAT)... DRY AND WARM PERIOD FOR THE MOST PART. SOME MOISTURE RETURNS FRI-SAT WITH A CHANCE OF DIURNAL SHOWERS AND THUNDERSTORMS. BETTER CHANCE APPEARS TO BE ON SATURDAY. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ ROSE
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1155 PM CDT FRI JUN 8 2012 .AVIATION.../06 TAFS/ FOR THE 06Z TAFS...STILL SOMEWHAT OF A LOW CONFIDENCE FORECAST. HAVE MODERATE CONFIDENCE THAT IFR CIGS WILL DEVELOP 0830-1430Z AT KAMA AND 08-1430Z AT KDHT. NOT OUT OF THE QUESTION THAT LIFR CIGS WILL OCCUR AT KAMA AND KDHT...BUT CONFIDENCE IS TOO LOW TO MENTION AT THIS TIME. IF LIFR CIGS OCCUR...MOST LIKELY TIME FRAME WILL BE 10-13Z. HAVE LOW TO MODERATE CONFIDENCE THAT MVFR CIGS WILL DEVELOP AT KGUY 09-13Z. HAVE HIGH CONFIDENCE THAT VFR CONDITIONS WILL PREVAIL AFTER 16Z SATURDAY. S/SSW WINDS WILL BE QUITE GUSTY 14-18Z...TEMPORARILY SUBSIDE 18-21Z...AND THEN INCREASE AGAIN 21-02Z. JACKSON && .PREV DISCUSSION... /ISSUED 800 PM CDT FRI JUN 8 2012/ UPDATE... UPDATE TO GRAPHICAL AND TEXT FORECASTS WILL BE COMING SHORTLY. WILL REMOVE SLIGHT CHANCE THUNDERSTORMS FROM NORTHWESTERN SECTIONS THIS EVENING. ATMOSPHERE EXPECTED TO REMAIN CAPPED...WITH DRYLINE REMAINING WEST OF FORECAST AREA...AND NO OPPORTUNE CONVERGENCE ZONE ANTICIPATED. REMAINING ELEMENTS OF FORECAST LOOK FINE. COCKRELL PREV DISCUSSION... /ISSUED 640 PM CDT FRI JUN 8 2012/ AVIATION.../00Z TAFS/ MVFR CIGS EXPECTED TO PERSIST AT KAMA THROUGH 02Z BEFORE BECOMING VFR THROUGH 09Z. HAVE MODERATE CONFIDENCE THAT IFR CIGS WILL DEVELOP 09Z-15Z. THERE IS A SMALL CHANCE OF LIFR CIGS 11Z-13Z. COULD SEE SOME BR DEVELOP...BUT THINK THE LOWEST FLIGHT CATEGORY WILL BE CAUSED BY CIGS. HAVE MODERATE CONFIDENCE THAT IFR CIGS WILL DEVELOP AT KDHT 0830Z- 1200Z. MAY SEE SOME BR...BUT SSW WINDS MAY PREVENT THIS FROM MATERIALIZING. HAVE LOW TO MODERATE CONFIDENCE THAT MVFR CIGS WILL DEVELOP AT KGUY 10Z-15Z. LIKE THE LAST COUPLE OF NIGHTS...DON/T BELIEVE ANY BR WILL DEVELOP. S/SSW WINDS WILL BECOME GUSTY AFTER 15Z SATURDAY AT ALL TAF SITES. JACKSON PREV DISCUSSION... /ISSUED 334 PM CDT FRI JUN 8 2012/ DISCUSSION... LOW CLOUDS HAVE MOSTLY DISSIPATED ACROSS THE PANHANDLES...EXCEPT IN ISOLATED LOCATIONS. SKIES SHOULD CONTINUE TO CLEAR FOR THE REMAINDER OF THE DAY. TONIGHT...CUMULUS HAS STARTED TO DEVELOP ALONG THE RATON MESA. IF THESE DEVELOP INTO SHOWERS AND STORMS...THEY COULD PROPAGATE INTO THE WESTERN OKLAHOMA PANHANDLE. AND IN FACT...THE RAP SHOWS THIS SCENARIO FOR A BRIEF WINDOW THIS EVENING. HIGH CIN VALUES AND RELATIVELY WEAK 0 TO 6 KM MEAN FLOW SHOULD LIMIT THE COVERAGE OF STORMS IN THE OK PANHANDLE THIS EVENING...BUT IT CAN NOT BE RULED OUT. THEREFORE...HAVE INCLUDED SLIGHT CHANCE OF THUNDERSTORMS IN THIS AREA. TOMORROW...THE DRYLINE SHOULD MOVE EAST INTO THE PANHANDLES TOMORROW. BUT A RELATIVELY WARM LAYER IN THE MID LEVELS SHOULD INHIBIT ANY CONVECTIVE INITIATION ALONG AND EAST OF THE DRYLINE. THE WARMING TREND WILL CONTINUE AS LOW LEVEL FLOW SHIFTS TO SOUTHWESTERLY. SUNDAY AND SUNDAY NIGHT...THE DRYLINE SHOULD CONTINUE ITS PROGRESS EAST...POSSIBLY MOVING EAST OF THE PANHANDLES ENTIRELY. BOTH THE NAM AND THE GFS CONTINUE TO SHOW THE COLD FRONT GETTING CLOSE TO...IF NOT ENTERING...THE PANHANDLES DURING THE DAY ON SUNDAY. HOWEVER...GIVEN THE STRONG SOUTHWESTERLY FLOW AHEAD OF THE FRONT...AND GIVEN THAT STRONG DAY TIME COLD FRONTS ARE ABNORMAL FOR MID JUNE...EXPECT THAT THE FRONT WILL SLOW IF NOT STALL NORTH OF THE REGION DURING THE DAY ON SUNDAY BEFORE PUSHING THROUGH THE REGION SUNDAY NIGHT. HAVE REMOVED THE SLIGHT CHANCE OF STORMS SUNDAY NIGHT...GIVEN THE DRY AIR ADVECTION EXPECTED AHEAD OF THE FRONT AS THE DRYLINE PROGRESSES EAST. MONDAY THROUGH THURSDAY...HAVE ALSO REMOVED MENTION OF THE SLIGHT CHANCE OF THUNDERSTORMS ON MONDAY AS THE BEST MOISTURE SHOULD STILL REMAIN NORTH AND EAST OF THE REGION. STARTING MONDAY NIGHT HOWEVER...GFS CONTINUES TO SHOW CHANCES FOR STORMS ASSOCIATED WITH A SERIES OF UPPER LEVEL SHORT WAVE TROUGHS EMBEDDED IN THE NORTHWEST FLOW THROUGH THURSDAY. THE ECMWF HOWEVER...IN A STARK DEPARTURE FROM BOTH THE GFS AND PREVIOUS RUNS OF THE ECMWF...NOW DOES NOT SHOW ANY SIGNIFICANT PRECIPITATION CHANCES UNTIL THURSDAY. THIS IS MAINLY DUE TO A SLOW MOISTURE RECOVERY BEHIND THE FRONT. AM HESITANT TO GO WITH THIS SOLUTION AT THIS TIME GIVEN THE POOR RUN TO RUN CONSISTENCY SO HAVE KEPT CLOSE TO THE PREVIOUS FORECAST AND THE GFS SOLUTION. JOHNSON FIRE WEATHER... THE DRYLINE WILL SHIFT INTO THE WESTERN...AND POSSIBLY CENTRAL PANHANDLES TOMORROW. WEST OF THE DRYLINE...MINIMUM RELATIVE HUMIDITY VALUES OF 5 TO 15 PERCENT AND SOUTHWESTERLY WINDS OF 15 TO 20 MPH ARE EXPECTED. HOWEVER...GIVEN RECENT RAINS AND GREEN FUELS...DO NOT EXPECT ELEVATED FIRE WEATHER CONDITIONS TOMORROW. EXPECT SIMILAR CONDITIONS ON SUNDAY...EXCEPT THE DRYLINE SHOULD SHIFT FURTHER EAST...POSSIBLY EAST OF THE PANHANDLES. STILL...GIVEN THE CONDITION OF THE FUELS DO NOT ANTICIPATE ELEVATED FIRE WEATHER CONDITIONS. A COLD FRONT...WITH AN ABRUPT SHIFT TO NORTHERLY WINDS...IS EXPECTED TO STAY JUST NORTH OF THE OKLAHOMA PANHANDLE ON SUNDAY...BUT PUSH THROUGH ALL OF THE PANHANDLES LATE SUNDAY NIGHT. COOLER WEATHER...AND THUS HIGHER RELATIVE HUMIDITY VALUES SHOULD PRECLUDE ANY ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS FROM MONDAY THROUGH FRIDAY. JOHNSON && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ JJ/JC
AREA FORECAST DISCUSSION
NWS SPOKANE WA
225 PM PDT Sat Jun 9 2012 .SYNOPSIS... The wet, cool and breezy weather for today will be replaced to drier and more seasonal weather for Sunday and into early next week. Under westerly flow aloft, a series of weak weather systems will bring a few afternoon and evening showers Tuesday and Wednesday. A stronger weather system is expected by the end of the week with a better chance of showers, meanwhile temperatures will stay near normal. && .DISCUSSION... Tonight and Sunday: The pesky cutoff low responsible for the cool and wet weather today, will slowly exit the region over the next 12-24 hours. Currently this feature is circulating over northwest Montana, while a wet northerly flow drops in from BC. This was depicted well in the 295k surface with strong isentropic lift through this afternoon and tapering off this evening. Under the west northwest flow, showers will linger in the Idaho panhandle as supported by the orographic flow overnight. Based the pops and weather mostly on the HRRR models in the near term and leaned to a NAM/GFS blend into Sunday. The low level westerly flow has mixed the surface with occasional gusty winds in the rain-free area of the lower Columbia basin, to the Palouse and LC valley. The cross Cascade surface pressure gradients have been increasing and this will enhance the wind speeds in the lee of the Cascades into the evening hours, especially in the Wenatchee area with gusts near the wind advisory criteria. The showers and winds will be tapering off overnight as low center creeps further east and the dry slot in the northwest flow moves over central Washington. A chance of showers will redevelop over northeast Washington and north Idaho by Sunday afternoon. Temperatures will moderate on Sunday, warming about 5-10 degrees over today, but still remain below normal for early June. /rfox. Sunday night through Tuesday...Through this portion of the forecast high pressure will track through the region followed by zonal flow as the next upstream weather disturbance begins to effect the region. The axis of the ridge of high pressure will be on the coast by Sunday evening, then track east across the Inland Northwest Sunday night, before flattening on Monday. The models are also very similar in showing a weak short wave disturbance moving through the ridge. There is little in the way of moisture associated with this wave and the likely results will be some alto-cumulus development. The aforementioned wave will increase winds slightly out of the southwest Monday with gusts around 10-15 mph. Temperatures will rise to near seasonal normals. Late Monday afternoon through Tuesday the ridge will flatten resulting in westerly zonal flow and increasing Pacific moisture. A few weak waves will pass through the region resulting in a few showers over the Cascades Monday night and increasing across the northern Washington mountains and Idaho Panhandle mountains Tuesday. These showers will need a little help with orographics and will be tied to the terrain. A slightly stronger wave is expected late Tuesday afternoon. In addition both the GFS and NAM are indicating surface based cape and negative LI`s stretching from just east of republic south to the Blue mountains. With the stronger wave acting as a kicker showers will be a little heavier and more widespread across the eastern half of the forecast area. The instability will be strong enough to support embedded thunderstorms and these were kept in the forecast and the area expanded slightly south. /Tobin Tuesday night through Saturday...Models are in good agreement concerning the long wave pattern in the extended with a progressive west to northwest flow with a series of weak systems passing across southern British Columbia, Northern Washington, and the Idaho Panhandle. The trajectory of these waves will keep a threat of showers in the forecast especially over the northern mountains where the best lift and instability will lie with each passing wave. GFS and ECMWF also show enough instability such that isolated thunderstorms may develop over the Northeast Washington Mountains and Idaho Panhandle. Models do show some timing/strength differences with each wave so confidence in the exact details is low. Given prevailing west- northwest flow there is higher confidence of dry conditions throughout the extended period in the Wenatchee and Moses Lake areas. Temperatures are expected to be near to slightly below normal through the period. /JW && .AVIATION... 18Z TAFS: A swath of precipitation has dropped south from BC and is bringing a steady cold rain east of a line from KOMK-KMWH. The KGEG-KCOE corridor can expect MVFR CIGS with rain through at least 02z with locally gusty southwest winds. Areas of MVFR CIGs will be near KPUW with some light rain. The mountains north and east of KGEG will experience even lower CIGS with mountains obscured and more moderate rain. Northwest winds will be on the increase in KEAT with dry conditions and gusts to 35kt. Locally gusty winds, VFR conditions with a slight chance of rain will be found in KMWH and KLWS. Rain will exit the region after 06z with gradual clearing from the northwest overnight into Sunday morning, while a chance of showers will linger in the Panhandle mountains. /rfox. && .PRELIMINARY POINT TEMPS/POPS... Spokane 43 66 46 72 52 73 / 50 10 0 0 10 40 Coeur d`Alene 44 63 46 71 50 72 / 30 10 10 10 10 40 Pullman 43 63 44 71 48 71 / 80 10 0 0 10 40 Lewiston 47 71 50 78 54 78 / 40 10 0 0 10 40 Colville 45 73 46 76 51 77 / 30 10 10 10 20 40 Sandpoint 44 61 43 70 46 69 / 50 30 10 10 20 50 Kellogg 41 56 44 68 48 69 / 80 50 10 10 20 50 Moses Lake 47 76 49 80 57 81 / 10 0 0 0 10 20 Wenatchee 49 75 52 79 59 79 / 10 0 0 0 10 10 Omak 44 77 46 79 53 80 / 10 10 0 10 10 20 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...Wind Advisory until 8 PM PDT this evening for Waterville Plateau- Wenatchee Area. && $$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1016 PM PDT Fri Jun 8 2012 .SYNOPSIS... A broad low pressure system spinning over the region will continue to fuel scattered showers and isolated thunderstorms through Saturday. Sunday will be a marginally drier day in Washington...with wet conditions persisting in the Idaho Panhandle. Temperatures will be well below normal Saturday. Temperatures will temporarily warm to seasonal levels for the beginning of the work week...but unsettled weather will likely return by the middle of next week. && .DISCUSSION... Update: mushy trough pattern in place, with several features migrating around the parent trough. The most notable is the low pressure center moving toward the southern Oregon coast, set to move inland overnight into Saturday. At the same time several minor vorticity lobes have been ejecting northeast across the Inland Northwest this evening. Trying to pick out each is difficult but the more distinct vorticity max tracked into the southeast CWA from Oregon this afternoon, with a second on its heels and tracking across north- northeast into the Basin and stretching across the I-90 corridor at this late hour. These helped trigger some scattered showers and the isolated embedded thunderstorm. These have been dissipating in coverage over the past couple hours and I adjusted PoPs to trim the risk back to slight/isolated over much of the region. The exception will remain across the Cascades through northern Washington mountains. Moisture wrapping around the broader trough and a secondary low developing around northeast Washington will help sustain and/or increase the threat of showers from the north through the night. Model guidance, including the latest run of the 3-KM HRRR model, shows the precipitation increasing across Okanogan and Ferry county overnight...especially after 09-10Z (or 2-3AM). As Saturday progresses trough axis pivots across the Pacific Northwest into the northern Rockies and the moisture and embedded disturbances pivoting around it are poised to expand the precipitation southeastward, between late morning and afternoon...before starting to shift out Saturday night. So away from the deeper Columbia Basin and lee of the Cascades, most locations have a good chance of seeing precipitation during the day Saturday. The combination of the precipitation, cloud cover and cool upper trough will lead much below normal afternoon highs. So record low maximum temperature are possible. /J. Cote` && .AVIATION... 06Z TAFS: A low pressure system will continue to migrate across the Pacific Northwest Friday night through Saturday. With instability waning for Friday night, mainly isolated shower are expected in the vicinity of TAF sites. However toward late morning to early afternoon Saturday moisture wrapping around the passing low will increase from the north, leading to increasing precipitation over most of the eastern TAF sites. Chances will also be found around KEAT/KMWH. The highest threat will be between 18Z and 03Z. During this period occnl MVFR/isolated IFR conditions can be expected around KGEG/KSFF/KCOE, while VFR/occnl MVFR near KPUW/KLWS. There is some disagreement over the precise timing of these deteriorating conditions; some guidance brings the threat in as early as 15Z. So the forecast will continue to be fine-tuned. After 03Z, most locations are expected to see improving conditions as the low begins to move out. KCOE/KPUW/KLWS may hold onto the lower conditions longer. /J. Cote` && .PRELIMINARY POINT TEMPS/POPS... Spokane 40 53 43 65 45 73 / 20 80 60 20 10 10 Coeur d`Alene 37 51 45 60 46 72 / 20 90 70 40 10 10 Pullman 37 53 43 61 44 71 / 20 80 60 20 10 10 Lewiston 42 60 48 69 49 77 / 20 70 50 20 0 0 Colville 40 56 46 72 45 77 / 50 80 60 20 10 10 Sandpoint 39 50 45 57 45 71 / 30 90 70 50 20 10 Kellogg 38 47 42 54 43 69 / 40 90 80 70 10 10 Moses Lake 42 67 47 75 49 79 / 20 40 10 10 0 0 Wenatchee 45 64 48 75 51 80 / 20 20 10 0 0 0 Omak 44 64 45 77 46 79 / 30 60 10 10 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
740 PM CDT SUN JUN 10 2012 .SHORT TERM...TONIGHT 740 PM CDT SUN JUN 10 2012 CONTINUE TO MONITOR CONVECTIVE TRENDS GOING INTO THIS EVENING AND OVERNIGHT AS A SWATH OF SHOWERS AND THUNDERSTORMS MOVE IN FROM THE WEST AHEAD AND JUST BEHIND A COLD FRONT THAT CURRENTLY STRETCHES FROM NORTH CENTRAL MINNESOTA DOWN TOWARD OMAHA. THE PEAK OF THESE STORMS OCCURRED LATE THIS AFTERNOON UNDER PEAK DIURNAL HEATING WHERE SBCAPE APPROACHED 3000 J/KG ACROSS CENTRAL MINNESOTA. THIS POCKET OF HIGHER INSTABILITY WAS MAINLY DUE TO MID LEVEL LAPSE RATES BEING A BIT STEEPER DUE TO THE MID LEVEL TROUGH SWINGING THROUGH. MANY OF THE STORMS SOUTH OF THIS HIGHER POCKET OF INSTABILITY...FROM SOUTH CENTRAL MINNESOTA THROUGH WESTERN IOWA...HAVE MAINLY BEEN SUB-SEVERE WITH A FEW SPORADIC GUSTS OF 50 MPH WHICH IS COINCIDENT WITH SBCAPE MORESO AROUND 1000-2000 J/KG. AS THE FRONT PROPAGATES EAST THIS EVENING...EXPECT THAT THE BAND OF SCATTERED CONVECTION WILL FOLLOW SUIT AS THE 10.21Z RAP AND HRRR SHOW A CORRIDOR OF AROUND 1000 J/KG MUCAPE PERSISTING AHEAD OF THE FRONT THROUGH THE OVERNIGHT HOURS. THESE SAME MESO MODELS SHOW SOME CONVECTION CONTINUING OVERNIGHT WITH MIXED LAYER CIN REMAINING RELATITVELY WEAK IN THIS NARROW PATH AHEAD OF THE FRONT. ALL OF THE SHEAR REMAINS IN THE LOWER 3KM AND STRONG ENOUGH AT ABOUT 20-30KTS TO PRODUCE SOME STRONG WIND GUSTS WITH THESE STORMS. THE 0-3KM SHEAR VECTOR IS POINTED TO THE NORTH- NORTHEAST...SO WOULD EXPECT THAT THESE STRONGER GUSTS WOULD COME WITH ANY NORTH-NORTHEASTWARD MOVING STORMS. OVERALL...STILL THINK THAT THERE IS A BRIEF WINDOW OF OPPORTUNITY TONIGHT FOR A STORM OR TWO TO PRODUCE SOME SEVERE WINDS...BUT THE MAJORITY OF THE CONVECTION SHOULD BE ON THE DOWNSWING THROUGH THE NIGHT. TIMING WISE...THE LEADING EDGE OF THE CONVECTION IN SOUTH CENTRAL MINNESOTA AND NORTH CENTRAL IOWA SHOULD GET INTO THE FORECAST AREA...DODGE COUNTY MN TO FLOYD COUNTY IA...AROUND 930 PM...TO ROCHESTER MN AROUND 10 PM...AND THE MISSISSIPPI RIVER SHORTLY AFTER MIDNIGHT. IF SOME PRECIPITATION DOES OCCUR...AND SKIES CLEAR OUT OVERNIGHT THERE COULD BE SOME SHALLOW GROUND FOG THAT FORMS WITH WINDS BEING LIGHT AND VARIABLE. THIS IS MORE LIKELY TO OCCUR ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA WHERE PRECIPITATION IS MORE LIKELY TO OCCUR ALONG WITH THE CLEARING SKIES...BUT CONFIDENCE IS NOT HIGH ENOUGH AT THIS POINT TO PUT INTO THE FORECAST. .LONG TERM...WEDNESDAY THROUGH SUNDAY 315 PM CDT SUN JUN 10 2012 NEARLY ZONAL FLOW WILL INITIALLY DEVELOP BEHIND THE SYSTEM FOR TUESDAY. THE 10.12Z ECMWF...GFS AND GEM ALL SHOW A SHORT WAVE TROUGH COMING ACROSS THE NORTHERN PLAINS WEDNESDAY. THE FORCING WITH THIS WAVE IS EXPECTED TO STAY TO THE NORTHWEST OF THE FORECAST AREA FOR NOW...SO HAVE MAINTAINED THE DRY FORECAST. AFTER THAT...RIDGING BUILDS OVER THE UPPER MIDWEST AND GREAT LAKES UNTIL NEXT WEEKEND. IT THEN LOOKS LIKE A SOUTHWEST FLOW WILL START TO DEVELOP AS THE RIDGE BEGINS TO MOVE OFF. SHORT WAVE TROUGHS IN THIS SOUTHWEST FLOW ARE EXPECTED TO BEGIN MOVING ACROSS THE REGION BRINGING SOME RAIN CHANCES STARTING SATURDAY AND CONTINUING THROUGH SUNDAY. HAVE STAYED WITH THE MODEL CONSENSUS GRIDS FOR NEXT WEEKEND BUT COULD EASILY SEE THESE BEING DELAYED WITH NOTED MODEL BIAS OF BEING TOO FAST WITH SOUTHWEST FLOW SYSTEMS. && .AVIATION...TONIGHT AND MONDAY 646 PM CDT SUN JUN 10 2012 A LINE OF THUNDERSTORMS HAVE DEVELOPED FROM NORTH CENTRAL MINNESOTA ALL THE WAY DOWN INTO SOUTHWEST IOWA RIGHT AHEAD OF A COLD FRONT. THESE STORMS WILL CONTINUE TO TRACK EASTWARD TONIGHT AHEAD OF THE FRONT WITH AN EXPECTED ARRIVAL TIME AT RST AROUND 3Z AND LSE AROUND 6Z. HOWEVER...THE TREND SHOULD BE FOR THESE STORMS TO BE WEAKENING AND DECREASING IN COVERAGE TONIGHT AS INSTABILITY RAPIDLY DECREASES AFTER SUNSET. STILL...THERE IS A HIGH PROBABILITY THAT THESE STORMS WILL MAKE IT INTO RST AND BRING SOME STRONG WIND GUSTS AND SUB-VFR CONDITIONS ALONG WITH IT. CHANCES FOR THUNDER AT LSE ARE NOT AS HIGH...BUT STILL POSSIBLE LATER TONIGHT. IF THE RAIN OCCURS AND SKIES CAN CLEAR OUT AT RST...THERE COULD BE SOME SHALLOW GROUND FOG THAT DEVELOPS BEFORE DAYBREAK. HAVE TRENDED DOWN TO 2SM IFR WITH THE TAFS...BUT COULD SEE SOME LOWER VISIBILITIES DOWN TO A 1/4SM. THE CLEARING AND LIGHT WINDS SHOULD COME IN LATE ENOUGH TOMORROW MORNING AROUND DAYBREAK THAT THE FOG DOES NOT LOOK AS LIKELY THERE. WINDS WILL THEN PICK UP OUT OF THE WEST-NORTHWEST AS A SECONDARY COLD FRONT COMES THROUGH LATE TOMORROW MORNING. && .ARX WATCHES/WARNINGS/ADVISORIES... 315 PM CDT SUN JUN 10 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...HALBACH LONG TERM...04 AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1214 PM CDT SAT JUN 9 2012 .SHORT TERM...TODAY THROUGH MONDAY NIGHT 310 AM CDT SAT JUN 9 2012 MAIN FORECAST CONCERN IS ON PRECIPITATION CHANCES SUNDAY NIGHT INTO MONDAY...AND ANY POTENTIAL SEVERE WEATHER WITH IT. CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED A DEEP UPPER TROUGH OVER THE NORTHWEST U.S. AND RIDGING OVER THE MID AND UPPER MISSISSIPPI RIVER VALLEYS. LOW LEVEL SOUTHWEST FLOW UNDER THE UPPER RIDGING HAS BEEN HELPING TO ADVECT DRIER AIR INTO THE AREA...AS SEEN IN GOES SOUNDER AND RAP PRECIPITABLE WATER ANALYSES. AN AREA OF VALUES AROUND 0.8 INCHES IN MISSOURI HAS BEEN STEADILY MOVING NORTHWARD INTO IOWA. THIS DRIER AIR MOVING IN HAS RESULTED IN MAINLY CLEAR SKIES OVERNIGHT. THE SOUTHWEST FLOW HAS ALSO BROUGHT WARMER AIR INTO THE REGION...WITH 850MB TEMPS FROM 00Z SOUNDINGS OF 19C AT MPX AND 16C AT GRB. NOTE THAT MPX MIXED UP TO 780MB YESTERDAY. THESE READINGS ARE HOLDING STEADY PER RAP ANALYSIS. WITH A SOUTHWEST BREEZE AND THE WARMER AIR...SURFACE TEMPERATURES HAVE ONLY DROPPED INTO THE MID 60S TO MID 70S. TO THE WEST OVER THE WESTERN PLAINS...LOW LEVEL FLOW IS A LITTLE MORE SOUTHERLY DOWNSTREAM OF THE NORTHWEST U.S. TROUGH. THE SOUTHERLY FLOW EXTENDS DOWN INTO TEXAS...HELPING TO PULL HIGHER PRECIPITABLE WATER VALUES OF 1-1.25 INCHES UP INTO THE DAKOTAS. SOME CONVECTION IS ALSO OCCURRING DOWNSTREAM OF THE TROUGH IN EASTERN MONTANA. TODAY THROUGH SUNDAY...MODELS ARE IN GOOD AGREEMENT LIFTING THE NORTHWEST U.S. TROUGH NORTHEASTWARD DURING THE WEEKEND...IN RESPONSE TO RIDGING THAT CONTINUES TO BUILT UP AHEAD OF IT. BY 00Z MONDAY... THE UPPER TROUGH SHOULD STRETCH FROM SASKATCHEWAN SOUTH INTO THE DAKOTAS. ALTHOUGH GOOD AGREEMENT EXISTS ON THE UPPER TROUGH...THERE REMAINS TIMING PROBLEMS WITH THE COLD FRONT PRECEDING THE TROUGH. THE 09.00Z NAM IS BY FAR THE FASTEST...HAVING IT REACH ROCHESTER BY 00Z MONDAY. THE 09.00Z GFS/UKMET/ECMWF/CANADIAN ARE ALL SLOWER... HAVING IT AT MOST IN EASTWARD PROGRESSION REACH ALBERT LEA BY 00Z MONDAY. PREFER TO STAY WITH THE CONSENSUS AND PAST MODEL RUNS WITH A SLOWER TIMING...WHICH WOULD MATCH THE UPPER FLOW IDEA WITH RIDGING BUILDING DOWNSTREAM OF THE UPPER TROUGH HELPING TO SLOW THINGS DOWN. THIS FRONT WILL BE THE MAIN FOCUS FOR PRECIPITATION...SINCE SOUTHERLY FLOW AHEAD OF IT LOOKS TO KEEP THE DRIER PRECIPITABLE WATER IN PLACE UNTIL LATE IN THE DAY SUNDAY. HOWEVER...THERE IS GREAT CONCERN THAT...DUE TO THE MIXING AND DRIER AIR AHEAD OF THE FRONT...ALL PRECIPITATION MAY END UP BEING POST-FRONTAL. THIS IS IN-LINE WITH THE 09.00Z CANADIAN/ECMWF. HAVE KEPT A LOW...20-30 PERCENT CHANCE OVER FAR WESTERN PORTIONS OF THE FORECAST AREA...JUST IN CASE MODELS SPEED UP. HOWEVER...LIKELY SUNDAY SHOULD BE DRY. ONLY OTHER CONCERN IS WINDS ON SUNDAY...DUE TO A TIGHTENING PRESSURE GRADIENT. SPEEDS COULD TRY TO GET UP CLOSE TO ADVISORY CRITERIA IN SOUTHEAST MINNESOTA. RIGHT NOW THINK THEY WILL STAY BELOW...BUT 25KT WINDS LOOK LIKELY AT DODGE CENTER AND ROCHESTER. REGARDING TEMPERATURES...WITH DRYING SOILS AND A LOT OF SUN...ALONG WITH THE BREEZE...DEEP MIXING LIKE WAS SEEN YESTERDAY SHOULD OCCUR BOTH TODAY AND SUNDAY. 850MB TEMPS OF 16-18C SUPPORTS HIGHS IN THE UPPER 80S TO LOWER 90S BOTH DAYS. DEWPOINTS LIKELY TO MIX OUT NICELY TOO. A BREEZY SATURDAY NIGHT AND WARMER DAY ON SATURDAY SHOULD RESULT IN LOWS A FEW DEGREES WARMER THAN TONIGHT. SUNDAY NIGHT INTO MONDAY...UPPER TROUGH WILL KEEP LIFTING NORTHEAST DURING THIS PERIOD...WITH A TRAILING SHORTWAVE PROGGED TO MOVE INTO THE FORECAST AREA ON MONDAY. AGAIN...THERE ARE SPEED ISSUES WITH BOTH THIS TRAILING SHORTWAVE AND PRECEDING COLD FRONT...WITH THE 09.00Z NAM THE FASTEST AND THE 09.00Z GFS NOT FAR BEHIND. STILL HAVE DECIDED TO LEAN A LITTLE SLOWER...CLOSER TO THE 09.00Z UKMET/CANADIAN/ECMWF GIVEN THE NAM BEING FASTEST FOR SUNDAY WITH THE FRONT. IN ANY EVENT...THE FRONT SHOULD PASS THROUGH MUCH IF NOT ALL OF THE AREA BY 18Z MONDAY. WITH THE FRONT NEARLY PARALLELING THE UPPER FLOW...THE BEST DYNAMICAL FORCING IS LIKELY TO STAY BEHIND THE FRONT. GIVEN A DRY AND CAPPED AIRMASS AHEAD OF THE FRONT...ANY CONVECTION/PRECIPITATION IS LIKELY TO EITHER BE TIED RIGHT ON THE FRONT OR BEHIND THE FRONT IN THE DYNAMICAL AND LOW TO MID-LEVEL FRONTOGENETICAL FORCING. THE WESTERN EXTENT OF THE PRECIPITATION IS GOING TO BE LIMITED BY A DRY SLOT ACCOMPANYING THE TRAILING SHORTWAVE. IN FACT...IT IS INTERESTING TO NOTE THAT PRECIPITABLE WATER VALUES JUMP UP TO 1.5-1.75 INCHES ALONG AND BEHIND THE FRONT...THEN ABOUT 70 MILES WEST OF THE FRONT AT 12Z MONDAY TANK TO 0.5 INCH OR LESS. THEREFORE...BEST TIMING FOR PRECIPITATION IS GOING TO BE SUNDAY NIGHT INTO MONDAY MORNING. IN FACT...NORTHWEST SECTIONS OF THE FORECAST AREA COULD END UP DRY IN THE MORNING. MOST PLACES SHOULD BE DRY IN THE AFTERNOON. WESTERN SECTIONS OF THE FORECAST AREA LOOK TO SEE THE MOST PRECIP OVERALL...SINCE MODEL PROGGED FRONTOGENESIS IS STRONGEST THERE AND SOME RIGHT ENTRANCE REGION OF AN UPPER JET LOOKS TO OCCUR. HAVE RAISED PRECIPITATION CHANCES TO 80-100 IN THIS AREA SUNDAY NIGHT. REGARDING SEVERE WEATHER...BEST CHANCE OF THIS IS IN THE EVENING OVER WESTERN SECTIONS OF THE AREA...WHEN MLCAPE IS IN THE 1000-1500 J/KG ON THE FRONT. BETTER 0-6KM SHEAR REMAINS WELL BEHIND THE FRONT...THOUGH 0-3KM SHEAR IS 30-35KT. DECENT TEMP/DEWPOINT SPREADS COMBINED WITH THE HIGHER 0-3KM SHEAR SUGGESTS WIND IS LIKELY TO BE THE MAIN HAZARD. TEMPERATURES SHOULD FALL INTO THE 60S SUNDAY NIGHT WITH THE RAIN AND FRONTAL PASSAGE. 850MB TEMPS ON MONDAY IN THE 13-16C RANGE AND INCREASING SUN SHOULD BRING HIGHS BACK UP INTO THE LOW TO PERHAPS EVEN MID 80S DEPENDING ON HOW MUCH SUN OCCURS. MONDAY NIGHT...UPPER FLOW IS FORECAST TO TURN ZONAL WITH THE UPPER TROUGH CONTINUING TO LIFT NORTHEAST INTO HUDSON BAY. SUBSIDENCE... COLD AND DRY AIR ADVECTION ALL LOOK TO OCCUR OVER THE FORECAST AREA THANKS TO THE SWITCH TO ZONAL FLOW...WITH CANADIAN HIGH PRESSURE BUILDING INTO THE NORTHERN PLAINS. 850MB TEMPS TANK TO 4-8C BY 12Z TUESDAY...PERHAPS EVEN COOLER PER THE 09.00Z NAM. AS SUCH...EXPECT A MUCH COOLER MONDAY NIGHT. GENERALLY FOLLOWED A BLEND OF GUIDANCE FOR LOWS. .LONG TERM...TUESDAY THROUGH FRIDAY 310 AM CDT SAT JUN 9 2012 09.00Z ECMWF/CANADIAN/GFS AND GFS ENSEMBLES IN DECENT AGREEMENT... ALONG WITH PREVIOUS RUNS...SHOWING THE ZONAL FLOW THAT DEVELOPS MONDAY NIGHT BEING TEMPORARY. BY THURSDAY...NEW TROUGHING IS SHOWN TO DROP INTO THE NORTHWEST U.S. AND SOUTHWEST CANADA...FORCING RIDGING TO BUILD DOWNSTREAM. MAIN FOCUS FOR PRECIPITATION CHANCES IS DURING THE TRANSITION BETWEEN THE ZONAL AND RIDGING BUILDING UP TOWARDS THE REGION. TUESDAY AND TUESDAY NIGHT LOOK DRY AND COOLER THAN OF LATE...DUE TO 850MB TEMPS 7-11C. THE WARM ADVECTION THEN COMMENCES. MODELS HAVE TRENDED WEDNESDAY TO BE DRY...SO HAVE FOLLOWED SUIT. WARM ADVECTION CONVECTION THEN LOOKS POSSIBLE WEDNESDAY NIGHT THROUGH THURSDAY NIGHT AS 850MB TEMPS SURGE UP TOWARDS 16-18C. FOLLOWED THE CONSENSUS CHANCES IN THE 20-30 RANGE SINCE IT IS POSSIBLE MOST OF THE WARM ADVECTION PRECIPITATION ENDS UP NORTHWEST OF THE AREA...CLOSER TO SHORTWAVES MOVING THROUGH THE MID-LEVEL FLOW. UPPER RIDGING AND SUBSIDENCE ARE FORECAST TO BE IN PLACE FOR FRIDAY...YIELDING A DRY DAY. 850MB TEMPS MAY EVEN CLIMB TOWARDS 20C FOR FRIDAY...SO DEFINITELY A WARM UP TO ABOVE NORMAL BY THE END OF THE WEEK. TEMPERATURES FOR BOTH THURSDAY AND FRIDAY MAY NEED A FURTHER BOOST UP OVER THE FORECAST...ESPECIALLY IF THE 09.00Z ECMWF VERIFIES. ABOVE NORMAL TEMPERATURES AND MAINLY DRY CONDITIONS LOOK TO PERSIST RIGHT INTO NEXT WEEKEND WITH 850MB TEMPS HOVERING AROUND 20C. && .AVIATION...THROUGH 18Z SUNDAY 1214 PM CDT SAT JUN 9 2012 VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD WITH WINDS THE ONLY CONCERN. TIGHT PRESSURE GRADIENT ALREADY IN PLACE BETWEEN HIGH PRESSURE OVER THE OHIO RIVER VALLEY AND AN AREA OF LOW PRESSURE OVER NORTH DAKOTA. THIS IS EXPECTED TO PRODUCE SUSTAINED WINDS GENERALLY IN THE 15 TO 20 KNOT RANGE WITH GUSTS OF 20 TO 25 KNOTS FOR THE REMAINDER OF THIS AFTERNOON. ENOUGH DECOULING OF THE WINDS WILL OCCUR THIS EVENING TO ALLOW THE WINDS TO SETTLE DOWN TO AROUND 10 KNOTS AND LOOSE THE GUSTS. THE WINDS ARE EXPECTED TO BE A LITTLE STRONGER SUNDAY AS THE SURFACE LOW MOVES OFF INTO CANADA...A SECOND LOW WILL FORM IN THE LEE OF THE ROCKIES AND MOVE INTO MINNESOTA. THIS WILL HELP TO BRING THE WINDS UP BY MID MORNING ONCE AGAIN INTO THE 15 TO 20 KNOT SUSTAINED CATEGORY WITH HIGHER GUSTS. THE HIGHEST WIND SPEED WILL OCCUR SUNDAY AFTERNOON WITH GUSTS IN EXCESS OF 30 KNOTS POSSIBLE AT KRST. && .CLIMATE... 310 AM CDT SAT JUN 9 2012 FIRST OFF...HIGHS BOTH TODAY AND SUNDAY COULD GET CLOSE TO RECORDS. RECORD HIGHS RANGE FROM 93-96 AT LA CROSSE AND ROCHESTER. SECONDLY...THERE ARE INCREASING INDICATIONS THAT THIS MONTH OF JUNE COULD BE PRETTY DRY ACROSS THE FORECAST AREA. SOME INDICATORS INCLUDE: 1. PER JUNE 5TH DROUGHT MONITOR...MUCH OF IOWA...KANSAS AND MISSOURI ARE DEVELOPING DROUGHT CONDITIONS. THIS IN TURN LIMITS EVAPOTRANSPORATION FROM CROPS AND OTHER VEGETATION. IN FACT...THERE ARE ALREADY REPORTS IN IOWA AND MISSOURI OF CURLING CORN LEAVES AND SOYBEAN EMERGENCE PROBLEMS. 2. WARM AND BREEZY DAYS THROUGH THIS WEEKEND HELPING TO FURTHER DRY OUT VEGETATION...WHICH ALSO IN TURN CAN MIX OUT MOISTURE IN THE AIR RETURNING NORTH FROM THE GULF OF MEXICO. 3. GOOD MODEL AGREEMENT SHOWING THE UPPER LEVEL PATTERN TRANSITIONING TO WESTERN TROUGHING AND STRONG EASTERN RIDGING... BLOCKING THE AREA FROM SEEING MUCH CONVECTION. 4. MANY CFS MODEL RUNS SHOWING THE REST OF THE MONTH OF JUNE TO AVERAGE WITH ABOVE NORMAL TEMPERATURES AND BELOW NORMAL PRECIPITATION. THEREFORE...HOPEFULLY THE FRONT ON SUNDAY NIGHT INTO MONDAY MORNING CAN GIVE OUR AREA A DECENT AMOUNT OF PRECIPITATION. OTHERWISE...IT APPEARS A DROUGHT MAY SET IN AS PRECIPITATION CHANCES AND COVERAGE IN THE EXTENDED ARE VERY UNCERTAIN. FOR REFERENCE...HERE ARE SOME LOWEST MONTHLY PRECIPITATION RECORDS. CERTAINLY PLENTY OF TIME TO GET MORE PRECIPITATION...BUT GIVEN THE DRY PATTERN...THESE MIGHT BE OF INTEREST. LA CROSSE...CURRENTLY STAND AT 0.06 INCHES. 1. 0.37 INCHES IN 1910 2. 0.98 INCHES IN 1887 3. 1.33 INCHES IN 1989 ROCHESTER...CURRENTLY STAND AT 0.08 INCHES. 1. TRACE IN 1910 2. 0.94 INCHES IN 1985 3. 1.08 INCHES IN 1964 && .ARX WATCHES/WARNINGS/ADVISORIES... 310 AM CDT SAT JUN 9 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...04 CLIMATE...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
652 AM CDT SAT JUN 9 2012 .SHORT TERM...TODAY THROUGH MONDAY NIGHT 310 AM CDT SAT JUN 9 2012 MAIN FORECAST CONCERN IS ON PRECIPITATION CHANCES SUNDAY NIGHT INTO MONDAY...AND ANY POTENTIAL SEVERE WEATHER WITH IT. CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED A DEEP UPPER TROUGH OVER THE NORTHWEST U.S. AND RIDGING OVER THE MID AND UPPER MISSISSIPPI RIVER VALLEYS. LOW LEVEL SOUTHWEST FLOW UNDER THE UPPER RIDGING HAS BEEN HELPING TO ADVECT DRIER AIR INTO THE AREA...AS SEEN IN GOES SOUNDER AND RAP PRECIPITABLE WATER ANALYSES. AN AREA OF VALUES AROUND 0.8 INCHES IN MISSOURI HAS BEEN STEADILY MOVING NORTHWARD INTO IOWA. THIS DRIER AIR MOVING IN HAS RESULTED IN MAINLY CLEAR SKIES OVERNIGHT. THE SOUTHWEST FLOW HAS ALSO BROUGHT WARMER AIR INTO THE REGION...WITH 850MB TEMPS FROM 00Z SOUNDINGS OF 19C AT MPX AND 16C AT GRB. NOTE THAT MPX MIXED UP TO 780MB YESTERDAY. THESE READINGS ARE HOLDING STEADY PER RAP ANALYSIS. WITH A SOUTHWEST BREEZE AND THE WARMER AIR...SURFACE TEMPERATURES HAVE ONLY DROPPED INTO THE MID 60S TO MID 70S. TO THE WEST OVER THE WESTERN PLAINS...LOW LEVEL FLOW IS A LITTLE MORE SOUTHERLY DOWNSTREAM OF THE NORTHWEST U.S. TROUGH. THE SOUTHERLY FLOW EXTENDS DOWN INTO TEXAS...HELPING TO PULL HIGHER PRECIPITABLE WATER VALUES OF 1-1.25 INCHES UP INTO THE DAKOTAS. SOME CONVECTION IS ALSO OCCURRING DOWNSTREAM OF THE TROUGH IN EASTERN MONTANA. TODAY THROUGH SUNDAY...MODELS ARE IN GOOD AGREEMENT LIFTING THE NORTHWEST U.S. TROUGH NORTHEASTWARD DURING THE WEEKEND...IN RESPONSE TO RIDGING THAT CONTINUES TO BUILT UP AHEAD OF IT. BY 00Z MONDAY... THE UPPER TROUGH SHOULD STRETCH FROM SASKATCHEWAN SOUTH INTO THE DAKOTAS. ALTHOUGH GOOD AGREEMENT EXISTS ON THE UPPER TROUGH...THERE REMAINS TIMING PROBLEMS WITH THE COLD FRONT PRECEDING THE TROUGH. THE 09.00Z NAM IS BY FAR THE FASTEST...HAVING IT REACH ROCHESTER BY 00Z MONDAY. THE 09.00Z GFS/UKMET/ECMWF/CANADIAN ARE ALL SLOWER... HAVING IT AT MOST IN EASTWARD PROGRESSION REACH ALBERT LEA BY 00Z MONDAY. PREFER TO STAY WITH THE CONSENSUS AND PAST MODEL RUNS WITH A SLOWER TIMING...WHICH WOULD MATCH THE UPPER FLOW IDEA WITH RIDGING BUILDING DOWNSTREAM OF THE UPPER TROUGH HELPING TO SLOW THINGS DOWN. THIS FRONT WILL BE THE MAIN FOCUS FOR PRECIPITATION...SINCE SOUTHERLY FLOW AHEAD OF IT LOOKS TO KEEP THE DRIER PRECIPITABLE WATER IN PLACE UNTIL LATE IN THE DAY SUNDAY. HOWEVER...THERE IS GREAT CONCERN THAT...DUE TO THE MIXING AND DRIER AIR AHEAD OF THE FRONT...ALL PRECIPITATION MAY END UP BEING POST-FRONTAL. THIS IS IN-LINE WITH THE 09.00Z CANADIAN/ECMWF. HAVE KEPT A LOW...20-30 PERCENT CHANCE OVER FAR WESTERN PORTIONS OF THE FORECAST AREA...JUST IN CASE MODELS SPEED UP. HOWEVER...LIKELY SUNDAY SHOULD BE DRY. ONLY OTHER CONCERN IS WINDS ON SUNDAY...DUE TO A TIGHTENING PRESSURE GRADIENT. SPEEDS COULD TRY TO GET UP CLOSE TO ADVISORY CRITERIA IN SOUTHEAST MINNESOTA. RIGHT NOW THINK THEY WILL STAY BELOW...BUT 25KT WINDS LOOK LIKELY AT DODGE CENTER AND ROCHESTER. REGARDING TEMPERATURES...WITH DRYING SOILS AND A LOT OF SUN...ALONG WITH THE BREEZE...DEEP MIXING LIKE WAS SEEN YESTERDAY SHOULD OCCUR BOTH TODAY AND SUNDAY. 850MB TEMPS OF 16-18C SUPPORTS HIGHS IN THE UPPER 80S TO LOWER 90S BOTH DAYS. DEWPOINTS LIKELY TO MIX OUT NICELY TOO. A BREEZY SATURDAY NIGHT AND WARMER DAY ON SATURDAY SHOULD RESULT IN LOWS A FEW DEGREES WARMER THAN TONIGHT. SUNDAY NIGHT INTO MONDAY...UPPER TROUGH WILL KEEP LIFTING NORTHEAST DURING THIS PERIOD...WITH A TRAILING SHORTWAVE PROGGED TO MOVE INTO THE FORECAST AREA ON MONDAY. AGAIN...THERE ARE SPEED ISSUES WITH BOTH THIS TRAILING SHORTWAVE AND PRECEDING COLD FRONT...WITH THE 09.00Z NAM THE FASTEST AND THE 09.00Z GFS NOT FAR BEHIND. STILL HAVE DECIDED TO LEAN A LITTLE SLOWER...CLOSER TO THE 09.00Z UKMET/CANADIAN/ECMWF GIVEN THE NAM BEING FASTEST FOR SUNDAY WITH THE FRONT. IN ANY EVENT...THE FRONT SHOULD PASS THROUGH MUCH IF NOT ALL OF THE AREA BY 18Z MONDAY. WITH THE FRONT NEARLY PARALLELING THE UPPER FLOW...THE BEST DYNAMICAL FORCING IS LIKELY TO STAY BEHIND THE FRONT. GIVEN A DRY AND CAPPED AIRMASS AHEAD OF THE FRONT...ANY CONVECTION/PRECIPITATION IS LIKELY TO EITHER BE TIED RIGHT ON THE FRONT OR BEHIND THE FRONT IN THE DYNAMICAL AND LOW TO MID-LEVEL FRONTOGENETICAL FORCING. THE WESTERN EXTENT OF THE PRECIPITATION IS GOING TO BE LIMITED BY A DRY SLOT ACCOMPANYING THE TRAILING SHORTWAVE. IN FACT...IT IS INTERESTING TO NOTE THAT PRECIPITABLE WATER VALUES JUMP UP TO 1.5-1.75 INCHES ALONG AND BEHIND THE FRONT...THEN ABOUT 70 MILES WEST OF THE FRONT AT 12Z MONDAY TANK TO 0.5 INCH OR LESS. THEREFORE...BEST TIMING FOR PRECIPITATION IS GOING TO BE SUNDAY NIGHT INTO MONDAY MORNING. IN FACT...NORTHWEST SECTIONS OF THE FORECAST AREA COULD END UP DRY IN THE MORNING. MOST PLACES SHOULD BE DRY IN THE AFTERNOON. WESTERN SECTIONS OF THE FORECAST AREA LOOK TO SEE THE MOST PRECIP OVERALL...SINCE MODEL PROGGED FRONTOGENESIS IS STRONGEST THERE AND SOME RIGHT ENTRANCE REGION OF AN UPPER JET LOOKS TO OCCUR. HAVE RAISED PRECIPITATION CHANCES TO 80-100 IN THIS AREA SUNDAY NIGHT. REGARDING SEVERE WEATHER...BEST CHANCE OF THIS IS IN THE EVENING OVER WESTERN SECTIONS OF THE AREA...WHEN MLCAPE IS IN THE 1000-1500 J/KG ON THE FRONT. BETTER 0-6KM SHEAR REMAINS WELL BEHIND THE FRONT...THOUGH 0-3KM SHEAR IS 30-35KT. DECENT TEMP/DEWPOINT SPREADS COMBINED WITH THE HIGHER 0-3KM SHEAR SUGGESTS WIND IS LIKELY TO BE THE MAIN HAZARD. TEMPERATURES SHOULD FALL INTO THE 60S SUNDAY NIGHT WITH THE RAIN AND FRONTAL PASSAGE. 850MB TEMPS ON MONDAY IN THE 13-16C RANGE AND INCREASING SUN SHOULD BRING HIGHS BACK UP INTO THE LOW TO PERHAPS EVEN MID 80S DEPENDING ON HOW MUCH SUN OCCURS. MONDAY NIGHT...UPPER FLOW IS FORECAST TO TURN ZONAL WITH THE UPPER TROUGH CONTINUING TO LIFT NORTHEAST INTO HUDSON BAY. SUBSIDENCE... COLD AND DRY AIR ADVECTION ALL LOOK TO OCCUR OVER THE FORECAST AREA THANKS TO THE SWITCH TO ZONAL FLOW...WITH CANADIAN HIGH PRESSURE BUILDING INTO THE NORTHERN PLAINS. 850MB TEMPS TANK TO 4-8C BY 12Z TUESDAY...PERHAPS EVEN COOLER PER THE 09.00Z NAM. AS SUCH...EXPECT A MUCH COOLER MONDAY NIGHT. GENERALLY FOLLOWED A BLEND OF GUIDANCE FOR LOWS. .LONG TERM...TUESDAY THROUGH FRIDAY 310 AM CDT SAT JUN 9 2012 09.00Z ECMWF/CANADIAN/GFS AND GFS ENSEMBLES IN DECENT AGREEMENT... ALONG WITH PREVIOUS RUNS...SHOWING THE ZONAL FLOW THAT DEVELOPS MONDAY NIGHT BEING TEMPORARY. BY THURSDAY...NEW TROUGHING IS SHOWN TO DROP INTO THE NORTHWEST U.S. AND SOUTHWEST CANADA...FORCING RIDGING TO BUILD DOWNSTREAM. MAIN FOCUS FOR PRECIPITATION CHANCES IS DURING THE TRANSITION BETWEEN THE ZONAL AND RIDGING BUILDING UP TOWARDS THE REGION. TUESDAY AND TUESDAY NIGHT LOOK DRY AND COOLER THAN OF LATE...DUE TO 850MB TEMPS 7-11C. THE WARM ADVECTION THEN COMMENCES. MODELS HAVE TRENDED WEDNESDAY TO BE DRY...SO HAVE FOLLOWED SUIT. WARM ADVECTION CONVECTION THEN LOOKS POSSIBLE WEDNESDAY NIGHT THROUGH THURSDAY NIGHT AS 850MB TEMPS SURGE UP TOWARDS 16-18C. FOLLOWED THE CONSENSUS CHANCES IN THE 20-30 RANGE SINCE IT IS POSSIBLE MOST OF THE WARM ADVECTION PRECIPITATION ENDS UP NORTHWEST OF THE AREA...CLOSER TO SHORTWAVES MOVING THROUGH THE MID-LEVEL FLOW. UPPER RIDGING AND SUBSIDENCE ARE FORECAST TO BE IN PLACE FOR FRIDAY...YIELDING A DRY DAY. 850MB TEMPS MAY EVEN CLIMB TOWARDS 20C FOR FRIDAY...SO DEFINITELY A WARM UP TO ABOVE NORMAL BY THE END OF THE WEEK. TEMPERATURES FOR BOTH THURSDAY AND FRIDAY MAY NEED A FURTHER BOOST UP OVER THE FORECAST...ESPECIALLY IF THE 09.00Z ECMWF VERIFIES. ABOVE NORMAL TEMPERATURES AND MAINLY DRY CONDITIONS LOOK TO PERSIST RIGHT INTO NEXT WEEKEND WITH 850MB TEMPS HOVERING AROUND 20C. && .AVIATION...TODAY AND TONIGHT 651 AM CDT SAT JUN 9 2012 MAIN FOCUS THROUGH THE PERIOD WILL BE WINDS TODAY. PRESSURE GRADIENT WILL BE INCREASING THROUGH THE DAY BETWEEN HIGH PRESSURE OVER THE OHIO RIVER VALLEY REGION AND DEEPENING LOW PRESSURE OVER THE NORTHERN PLAINS. WITH DEEP MIXING OF THE BOUNDARY LAYER TODAY...PLAN ON GUSTY SOUTH/SOUTHWEST WINDS KICKING UP LATER THIS MORNING AND LASTING THROUGH THE AFTERNOON. GUSTS IN THE 25 TO 30 KT RANGE LOOKS LIKELY AT KRST WITH 20 TO 25KT EXPECTED AT KLSE. CLEAR SKIES WILL BE SEEN TONIGHT WITH GUSTY WINDS SUBSIDING AROUND SUNSET WITH LOSS OF DEEP MIXING. WAS CONTEMPLATING LOW LEVEL WIND SHEAR OVERNIGHT...BUT CRITERIA WILL TECHNICALLY NOT BE MET. COULD STILL BE A BUMPY TAKE OFF/FINAL APPROACH WITH WINDS AROUND 2KFT EXPECTED TO BE AROUND 35KT. OTHERWISE...PLAN ON VFR CONDITIONS. && .CLIMATE... 310 AM CDT SAT JUN 9 2012 FIRST OFF...HIGHS BOTH TODAY AND SUNDAY COULD GET CLOSE TO RECORDS. RECORD HIGHS RANGE FROM 93-96 AT LA CROSSE AND ROCHESTER. SECONDLY...THERE ARE INCREASING INDICATIONS THAT THIS MONTH OF JUNE COULD BE PRETTY DRY ACROSS THE FORECAST AREA. SOME INDICATORS INCLUDE: 1. PER JUNE 5TH DROUGHT MONITOR...MUCH OF IOWA...KANSAS AND MISSOURI ARE DEVELOPING DROUGHT CONDITIONS. THIS IN TURN LIMITS EVAPOTRANSPORATION FROM CROPS AND OTHER VEGETATION. IN FACT...THERE ARE ALREADY REPORTS IN IOWA AND MISSOURI OF CURLING CORN LEAVES AND SOYBEAN EMERGENCE PROBLEMS. 2. WARM AND BREEZY DAYS THROUGH THIS WEEKEND HELPING TO FURTHER DRY OUT VEGETATION...WHICH ALSO IN TURN CAN MIX OUT MOISTURE IN THE AIR RETURNING NORTH FROM THE GULF OF MEXICO. 3. GOOD MODEL AGREEMENT SHOWING THE UPPER LEVEL PATTERN TRANSITIONING TO WESTERN TROUGHING AND STRONG EASTERN RIDGING... BLOCKING THE AREA FROM SEEING MUCH CONVECTION. 4. MANY CFS MODEL RUNS SHOWING THE REST OF THE MONTH OF JUNE TO AVERAGE WITH ABOVE NORMAL TEMPERATURES AND BELOW NORMAL PRECIPITATION. THEREFORE...HOPEFULLY THE FRONT ON SUNDAY NIGHT INTO MONDAY MORNING CAN GIVE OUR AREA A DECENT AMOUNT OF PRECIPITATION. OTHERWISE...IT APPEARS A DROUGHT MAY SET IN AS PRECIPITATION CHANCES AND COVERAGE IN THE EXTENDED ARE VERY UNCERTAIN. FOR REFERENCE...HERE ARE SOME LOWEST MONTHLY PRECIPITATION RECORDS. CERTAINLY PLENTY OF TIME TO GET MORE PRECIPITATION...BUT GIVEN THE DRY PATTERN...THESE MIGHT BE OF INTEREST. LA CROSSE...CURRENTLY STAND AT 0.06 INCHES. 1. 0.37 INCHES IN 1910 2. 0.98 INCHES IN 1887 3. 1.33 INCHES IN 1989 ROCHESTER...CURRENTLY STAND AT 0.08 INCHES. 1. TRACE IN 1910 2. 0.94 INCHES IN 1985 3. 1.08 INCHES IN 1964 && .ARX WATCHES/WARNINGS/ADVISORIES... 310 AM CDT SAT JUN 9 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...DAS CLIMATE...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
310 AM CDT SAT JUN 9 2012 .SHORT TERM...TODAY THROUGH MONDAY NIGHT 310 AM CDT SAT JUN 9 2012 MAIN FORECAST CONCERN IS ON PRECIPITATION CHANCES SUNDAY NIGHT INTO MONDAY...AND ANY POTENTIAL SEVERE WEATHER WITH IT. CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED A DEEP UPPER TROUGH OVER THE NORTHWEST U.S. AND RIDGING OVER THE MID AND UPPER MISSISSIPPI RIVER VALLEYS. LOW LEVEL SOUTHWEST FLOW UNDER THE UPPER RIDGING HAS BEEN HELPING TO ADVECT DRIER AIR INTO THE AREA...AS SEEN IN GOES SOUNDER AND RAP PRECIPITABLE WATER ANALYSES. AN AREA OF VALUES AROUND 0.8 INCHES IN MISSOURI HAS BEEN STEADILY MOVING NORTHWARD INTO IOWA. THIS DRIER AIR MOVING IN HAS RESULTED IN MAINLY CLEAR SKIES OVERNIGHT. THE SOUTHWEST FLOW HAS ALSO BROUGHT WARMER AIR INTO THE REGION...WITH 850MB TEMPS FROM 00Z SOUNDINGS OF 19C AT MPX AND 16C AT GRB. NOTE THAT MPX MIXED UP TO 780MB YESTERDAY. THESE READINGS ARE HOLDING STEADY PER RAP ANALYSIS. WITH A SOUTHWEST BREEZE AND THE WARMER AIR...SURFACE TEMPERATURES HAVE ONLY DROPPED INTO THE MID 60S TO MID 70S. TO THE WEST OVER THE WESTERN PLAINS...LOW LEVEL FLOW IS A LITTLE MORE SOUTHERLY DOWNSTREAM OF THE NORTHWEST U.S. TROUGH. THE SOUTHERLY FLOW EXTENDS DOWN INTO TEXAS...HELPING TO PULL HIGHER PRECIPITABLE WATER VALUES OF 1-1.25 INCHES UP INTO THE DAKOTAS. SOME CONVECTION IS ALSO OCCURRING DOWNSTREAM OF THE TROUGH IN EASTERN MONTANA. TODAY THROUGH SUNDAY...MODELS ARE IN GOOD AGREEMENT LIFTING THE NORTHWEST U.S. TROUGH NORTHEASTWARD DURING THE WEEKEND...IN RESPONSE TO RIDGING THAT CONTINUES TO BUILT UP AHEAD OF IT. BY 00Z MONDAY... THE UPPER TROUGH SHOULD STRETCH FROM SASKATCHEWAN SOUTH INTO THE DAKOTAS. ALTHOUGH GOOD AGREEMENT EXISTS ON THE UPPER TROUGH...THERE REMAINS TIMING PROBLEMS WITH THE COLD FRONT PRECEDING THE TROUGH. THE 09.00Z NAM IS BY FAR THE FASTEST...HAVING IT REACH ROCHESTER BY 00Z MONDAY. THE 09.00Z GFS/UKMET/ECMWF/CANADIAN ARE ALL SLOWER... HAVING IT AT MOST IN EASTWARD PROGRESSION REACH ALBERT LEA BY 00Z MONDAY. PREFER TO STAY WITH THE CONSENSUS AND PAST MODEL RUNS WITH A SLOWER TIMING...WHICH WOULD MATCH THE UPPER FLOW IDEA WITH RIDGING BUILDING DOWNSTREAM OF THE UPPER TROUGH HELPING TO SLOW THINGS DOWN. THIS FRONT WILL BE THE MAIN FOCUS FOR PRECIPITATION...SINCE SOUTHERLY FLOW AHEAD OF IT LOOKS TO KEEP THE DRIER PRECIPITABLE WATER IN PLACE UNTIL LATE IN THE DAY SUNDAY. HOWEVER...THERE IS GREAT CONCERN THAT...DUE TO THE MIXING AND DRIER AIR AHEAD OF THE FRONT...ALL PRECIPITATION MAY END UP BEING POST-FRONTAL. THIS IS IN-LINE WITH THE 09.00Z CANADIAN/ECMWF. HAVE KEPT A LOW...20-30 PERCENT CHANCE OVER FAR WESTERN PORTIONS OF THE FORECAST AREA...JUST IN CASE MODELS SPEED UP. HOWEVER...LIKELY SUNDAY SHOULD BE DRY. ONLY OTHER CONCERN IS WINDS ON SUNDAY...DUE TO A TIGHTENING PRESSURE GRADIENT. SPEEDS COULD TRY TO GET UP CLOSE TO ADVISORY CRITERIA IN SOUTHEAST MINNESOTA. RIGHT NOW THINK THEY WILL STAY BELOW...BUT 25KT WINDS LOOK LIKELY AT DODGE CENTER AND ROCHESTER. REGARDING TEMPERATURES...WITH DRYING SOILS AND A LOT OF SUN...ALONG WITH THE BREEZE...DEEP MIXING LIKE WAS SEEN YESTERDAY SHOULD OCCUR BOTH TODAY AND SUNDAY. 850MB TEMPS OF 16-18C SUPPORTS HIGHS IN THE UPPER 80S TO LOWER 90S BOTH DAYS. DEWPOINTS LIKELY TO MIX OUT NICELY TOO. A BREEZY SATURDAY NIGHT AND WARMER DAY ON SATURDAY SHOULD RESULT IN LOWS A FEW DEGREES WARMER THAN TONIGHT. SUNDAY NIGHT INTO MONDAY...UPPER TROUGH WILL KEEP LIFTING NORTHEAST DURING THIS PERIOD...WITH A TRAILING SHORTWAVE PROGGED TO MOVE INTO THE FORECAST AREA ON MONDAY. AGAIN...THERE ARE SPEED ISSUES WITH BOTH THIS TRAILING SHORTWAVE AND PRECEDING COLD FRONT...WITH THE 09.00Z NAM THE FASTEST AND THE 09.00Z GFS NOT FAR BEHIND. STILL HAVE DECIDED TO LEAN A LITTLE SLOWER...CLOSER TO THE 09.00Z UKMET/CANADIAN/ECMWF GIVEN THE NAM BEING FASTEST FOR SUNDAY WITH THE FRONT. IN ANY EVENT...THE FRONT SHOULD PASS THROUGH MUCH IF NOT ALL OF THE AREA BY 18Z MONDAY. WITH THE FRONT NEARLY PARALLELING THE UPPER FLOW...THE BEST DYNAMICAL FORCING IS LIKELY TO STAY BEHIND THE FRONT. GIVEN A DRY AND CAPPED AIRMASS AHEAD OF THE FRONT...ANY CONVECTION/PRECIPITATION IS LIKELY TO EITHER BE TIED RIGHT ON THE FRONT OR BEHIND THE FRONT IN THE DYNAMICAL AND LOW TO MID-LEVEL FRONTOGENETICAL FORCING. THE WESTERN EXTENT OF THE PRECIPITATION IS GOING TO BE LIMITED BY A DRY SLOT ACCOMPANYING THE TRAILING SHORTWAVE. IN FACT...IT IS INTERESTING TO NOTE THAT PRECIPITABLE WATER VALUES JUMP UP TO 1.5-1.75 INCHES ALONG AND BEHIND THE FRONT...THEN ABOUT 70 MILES WEST OF THE FRONT AT 12Z MONDAY TANK TO 0.5 INCH OR LESS. THEREFORE...BEST TIMING FOR PRECIPITATION IS GOING TO BE SUNDAY NIGHT INTO MONDAY MORNING. IN FACT...NORTHWEST SECTIONS OF THE FORECAST AREA COULD END UP DRY IN THE MORNING. MOST PLACES SHOULD BE DRY IN THE AFTERNOON. WESTERN SECTIONS OF THE FORECAST AREA LOOK TO SEE THE MOST PRECIP OVERALL...SINCE MODEL PROGGED FRONTOGENESIS IS STRONGEST THERE AND SOME RIGHT ENTRANCE REGION OF AN UPPER JET LOOKS TO OCCUR. HAVE RAISED PRECIPITATION CHANCES TO 80-100 IN THIS AREA SUNDAY NIGHT. REGARDING SEVERE WEATHER...BEST CHANCE OF THIS IS IN THE EVENING OVER WESTERN SECTIONS OF THE AREA...WHEN MLCAPE IS IN THE 1000-1500 J/KG ON THE FRONT. BETTER 0-6KM SHEAR REMAINS WELL BEHIND THE FRONT...THOUGH 0-3KM SHEAR IS 30-35KT. DECENT TEMP/DEWPOINT SPREADS COMBINED WITH THE HIGHER 0-3KM SHEAR SUGGESTS WIND IS LIKELY TO BE THE MAIN HAZARD. TEMPERATURES SHOULD FALL INTO THE 60S SUNDAY NIGHT WITH THE RAIN AND FRONTAL PASSAGE. 850MB TEMPS ON MONDAY IN THE 13-16C RANGE AND INCREASING SUN SHOULD BRING HIGHS BACK UP INTO THE LOW TO PERHAPS EVEN MID 80S DEPENDING ON HOW MUCH SUN OCCURS. MONDAY NIGHT...UPPER FLOW IS FORECAST TO TURN ZONAL WITH THE UPPER TROUGH CONTINUING TO LIFT NORTHEAST INTO HUDSON BAY. SUBSIDENCE... COLD AND DRY AIR ADVECTION ALL LOOK TO OCCUR OVER THE FORECAST AREA THANKS TO THE SWITCH TO ZONAL FLOW...WITH CANADIAN HIGH PRESSURE BUILDING INTO THE NORTHERN PLAINS. 850MB TEMPS TANK TO 4-8C BY 12Z TUESDAY...PERHAPS EVEN COOLER PER THE 09.00Z NAM. AS SUCH...EXPECT A MUCH COOLER MONDAY NIGHT. GENERALLY FOLLOWED A BLEND OF GUIDANCE FOR LOWS. .LONG TERM...TUESDAY THROUGH FRIDAY 310 AM CDT SAT JUN 9 2012 09.00Z ECMWF/CANADIAN/GFS AND GFS ENSEMBLES IN DECENT AGREEMENT... ALONG WITH PREVIOUS RUNS...SHOWING THE ZONAL FLOW THAT DEVELOPS MONDAY NIGHT BEING TEMPORARY. BY THURSDAY...NEW TROUGHING IS SHOWN TO DROP INTO THE NORTHWEST U.S. AND SOUTHWEST CANADA...FORCING RIDGING TO BUILD DOWNSTREAM. MAIN FOCUS FOR PRECIPITATION CHANCES IS DURING THE TRANSITION BETWEEN THE ZONAL AND RIDGING BUILDING UP TOWARDS THE REGION. TUESDAY AND TUESDAY NIGHT LOOK DRY AND COOLER THAN OF LATE...DUE TO 850MB TEMPS 7-11C. THE WARM ADVECTION THEN COMMENCES. MODELS HAVE TRENDED WEDNESDAY TO BE DRY...SO HAVE FOLLOWED SUIT. WARM ADVECTION CONVECTION THEN LOOKS POSSIBLE WEDNESDAY NIGHT THROUGH THURSDAY NIGHT AS 850MB TEMPS SURGE UP TOWARDS 16-18C. FOLLOWED THE CONSENSUS CHANCES IN THE 20-30 RANGE SINCE IT IS POSSIBLE MOST OF THE WARM ADVECTION PRECIPITATION ENDS UP NORTHWEST OF THE AREA...CLOSER TO SHORTWAVES MOVING THROUGH THE MID-LEVEL FLOW. UPPER RIDGING AND SUBSIDENCE ARE FORECAST TO BE IN PLACE FOR FRIDAY...YIELDING A DRY DAY. 850MB TEMPS MAY EVEN CLIMB TOWARDS 20C FOR FRIDAY...SO DEFINITELY A WARM UP TO ABOVE NORMAL BY THE END OF THE WEEK. TEMPERATURES FOR BOTH THURSDAY AND FRIDAY MAY NEED A FURTHER BOOST UP OVER THE FORECAST...ESPECIALLY IF THE 09.00Z ECMWF VERIFIES. ABOVE NORMAL TEMPERATURES AND MAINLY DRY CONDITIONS LOOK TO PERSIST RIGHT INTO NEXT WEEKEND WITH 850MB TEMPS HOVERING AROUND 20C. && .AVIATION...THROUGH 06Z SUNDAY 1130 PM CDT FRI JUN 8 2012 THE MAIN FOCUS AT THE TAF SITES IS WITH THE WIND ON SATURDAY...PARTICULARLY WITH WHEN IT BEGINS AND HOW HIGH THE GUSTS WILL GET TOMORROW AFTERNOON. WITH THE TIGHT SURFACE PRESSURE GRADIENT ALREADY IN PLACE...IT APPEARS THAT WINDS WILL START GUSTING EARLY WITH THE PEAK GUSTS IN THE 20 TO 25KT RANGE IN THE AFTERNOON. THESE GUSTS SHOULD SUBSIDE BY AROUND 1Z TOMORROW EVENING AS THE ATMOSPHERE DECOUPLES. OTHERWISE...SKIES WILL BE MAINLY CLEAR OUTSIDE OF SOME SPORADIC CIRRUS CLOUDS. && .CLIMATE... 310 AM CDT SAT JUN 9 2012 FIRST OFF...HIGHS BOTH TODAY AND SUNDAY COULD GET CLOSE TO RECORDS. RECORD HIGHS RANGE FROM 93-96 AT LA CROSSE AND ROCHESTER. SECONDLY...THERE ARE INCREASING INDICATIONS THAT THIS MONTH OF JUNE COULD BE PRETTY DRY ACROSS THE FORECAST AREA. SOME INDICATORS INCLUDE: 1. PER JUNE 5TH DROUGHT MONITOR...MUCH OF IOWA...KANSAS AND MISSOURI ARE DEVELOPING DROUGHT CONDITIONS. THIS IN TURN LIMITS EVAPOTRANSPORATION FROM CROPS AND OTHER VEGETATION. IN FACT...THERE ARE ALREADY REPORTS IN IOWA AND MISSOURI OF CURLING CORN LEAVES AND SOYBEAN EMERGENCE PROBLEMS. 2. WARM AND BREEZY DAYS THROUGH THIS WEEKEND HELPING TO FURTHER DRY OUT VEGETATION...WHICH ALSO IN TURN CAN MIX OUT MOISTURE IN THE AIR RETURNING NORTH FROM THE GULF OF MEXICO. 3. GOOD MODEL AGREEMENT SHOWING THE UPPER LEVEL PATTERN TRANSITIONING TO WESTERN TROUGHING AND STRONG EASTERN RIDGING... BLOCKING THE AREA FROM SEEING MUCH CONVECTION. 4. MANY CFS MODEL RUNS SHOWING THE REST OF THE MONTH OF JUNE TO AVERAGE WITH ABOVE NORMAL TEMPERATURES AND BELOW NORMAL PRECIPITATION. THEREFORE...HOPEFULLY THE FRONT ON SUNDAY NIGHT INTO MONDAY MORNING CAN GIVE OUR AREA A DECENT AMOUNT OF PRECIPITATION. OTHERWISE...IT APPEARS A DROUGHT MAY SET IN AS PRECIPITATION CHANCES AND COVERAGE IN THE EXTENDED ARE VERY UNCERTAIN. FOR REFERENCE...HERE ARE SOME LOWEST MONTHLY PRECIPITATION RECORDS. CERTAINLY PLENTY OF TIME TO GET MORE PRECIPITATION...BUT GIVEN THE DRY PATTERN...THESE MIGHT BE OF INTEREST. LA CROSSE...CURRENTLY STAND AT 0.06 INCHES. 1. 0.37 INCHES IN 1910 2. 0.98 INCHES IN 1887 3. 1.33 INCHES IN 1989 ROCHESTER...CURRENTLY STAND AT 0.08 INCHES. 1. TRACE IN 1910 2. 0.94 INCHES IN 1985 3. 1.08 INCHES IN 1964 && .ARX WATCHES/WARNINGS/ADVISORIES... 310 AM CDT SAT JUN 9 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...HALBACH CLIMATE...AJ
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
301 AM CDT MON JUN 11 2012 .DISCUSSION... 929 PM CDT SOME MINOR CHANGES MADE TO ARRIVAL TIMING OF POPS FOR MONDAY MORNING...OTHERWISE NO REAL CHANGES MADE TO GOING FORECAST FOR TONIGHT INTO MONDAY. EXPANSIVE UPPER LEVEL LOW AND ASSOCIATED HIGH PWAT AIR...AS SEEN ON WATER VAPOR...IS EXPANDING NORTHWARD. A WEAK UPPER LEVEL WAVE IN SOUTHWEST IL THIS EVE HAS HELPED TO SPREAD THIS NORTH CAUSING AN EXPANSION IN HIGH CLOUDS ACROSS THE AREA...WHICH SHOULD CONTINUE INTO OVERNIGHT. THESE CLOUDS ALONG WITH SOUTHERLY FLOW REMAINING AROUND 10 MPH TONIGHT SHOULD KEEP MINIMUM TEMPERATURES 3 TO 5 DEGREES WARMER THAN LAST NIGHT...WHICH IS RIGHT ON PAR WITH GOING FORECAST. LIGHT RETURNS ON THE KIND RADAR ARE INDICATIVE OF GRADUAL MID-LEVEL ASCENT AND SATURATION OCCURRING AHEAD OF THIS UPPER LOW. SATELLITE TRENDS AND GUIDANCE FORECASTS KEEP ALMOST ALL OF THIS ENTIRELY EAST OF THE AREA LATER TONIGHT INTO MONDAY MORNING. THE FEATURE WHICH WILL HAVE MORE INFLUENCE ON THE AREA IS A WELL- DEFINED UPPER LEVEL TROUGH ACROSS THE CANADIAN/U.S. HIGH PLAINS BORDER. IMPRESSIVE NORTH-TO-SOUTH LINE OF CONVECTION FROM NEAR INTERNATIONAL FALLS TO NORTHEAST KS HAS DEVELOPED JUST AHEAD OF THE SURFACE COOL FRONT WHERE CONVERGENCE WAS MAXIMIZED AND WITHIN A CORRIDOR OF HIGHER THETA-E RETURN. THE FRONT AND CONVECTION AHEAD OF IT WILL EVOLVE EAST INTO OVERNIGHT...LIKELY GRADUALLY TAPERING IN INTENSITY AND AT LEAST SOMEWHAT IN COVERAGE OVERNIGHT ACROSS IA AND NORTHERN MO. A PORTION OF THIS MAY MAKE IT INTO THE WESTERN FORECAST AREA IN THE EARLY MORNING...AND THE HRRR SOLUTION DEPICTS THIS...HOWEVER IT SEEMS TOO GENEROUS ON DEVELOPMENT OVERNIGHT IN THE ABSENCE OF MUCH OF A LOW-LEVEL JET/WAA. THE MID-LEVEL SHORT WAVE AXIS ACROSS EASTERN NE AND KS HELPING TO DRIVE SOME OF THE CONVECTION IS DEPICTED IN MOST GUIDANCE...AND TRACKS ACROSS THE FORECAST AREA DURING THE LATE MORNING AND AFTERNOON. COLLOCATED WITH THIS APPEARS TO BE A PRE-FRONTAL TROUGH...AT LEAST IN THE 925-700MB FLOW...WHICH HELPS IN FOCUSING SOME OF THE CONVERGENCE FIELDS. INSTABILITY VALUES ARE SIMILAR ON THE 11.00 NAM TO THOSE MENTIONED IN PRIOR DISCUSSION...SO SOME SCATTERED CONVECTION REGENERATING IN COVERAGE DURING THE MIDDAY TIME IS FAVORED AT THIS TIME. HAVE ADJUSTED MORNING POPS TO ACCOUNT FOR THIS TYPE OF TIMING/REASONING. AFTERNOON POPS STILL LOOK GOOD. MTF //PREV DISCUSSION... 317 PM CDT FOCUS OF FORECAST IS ON RAIN CHANCES MON AND MON EVE WITH A COLD FRONT MOVING ACROSS THE AREA...AND THEN ON THE VERY LOW...IF ANY...PROBABILITIES FOR RAIN THROUGH THE REST OF THE WORK WEEK AND WELL INTO NEXT WEEKEND. AN UPPER LOW OVER SOUTHERN SASKATCHEWAN AND NORTHEASTERN MT HAS CONTINUED TO BECOME SHEARED/ELONGATED TODAY...SLOWING ITS EASTWARD PROGRESS. AS A RESULT THE ASSOCIATED SURFACE LOW AND ATTENDANT COLD FRONT HAVE ALSO BEEN RELUCTANT TO MOVE EASTWARD WITH ANY VIGOR. MODELS SHOW THE UPPER LOW IS TO ACCELERATE NORTHEASTWARD LATER TODAY AND TONIGHT AS A SHORT WAVE AND JET MAX DIG SSE FROM THE YUKON-NW TERRITORIES BORDER TO SOUTHERN SASKATCHEWAN AND NE MT BY 12Z MON. THIS SHORT WAVE AND SPEED MAX ARE THEN PROGGED TO TURN SOUTHEASTERLY ACROSS THE DAKOTAS AND MN DURING THE DAY MON. WITH THE UPPER TROUGH BECOMING MORE PROGRESSIVE THE COLD FRONT...WHICH IS CURRENTLY LINGERING ACROSS NW AND W CENTRAL MN AND FAR SE SD AND NE NE... WILL ALSO START TO ACCELERATE EASTWARD...REACHING THE MID MS VALLEY BY EARLY MON AFTERNOON AND CONTINUING TO SE WI AND NE IL EARLY MON EVENING. CONVERGENCE ALONG THE COLD FRONT AS IT MOVES ACROSS THE LOCAL FORECAST AREA IS NOT VERY STRONG THOUGH TIMING OF THE FRONTAL PASSAGE DURING OR SOON AFTER PEAK HEATING LEADS TO IT OCCURRING WHEN INSTABILITY WILL BE MAXIMIZED WITH DEW POINTS SLOWLY CREEPING UP INTO THE 60S OVERNIGHT AND MON. HOWEVER...IF 10.12Z RUN OF GFS VERIFIES WITH THE LAYER FROM 2 TO 4K FT AGL SOME 3-4 DEG C WARMER THAN THE NAM SOLUTION DURING THE DAY MON THEN CONVECTIVE DEVELOPMENT AHEAD OF THE COLD FRONT WILL BE INHIBITED BY THE WARMTH ALOFT MAINTAINING A SIGNIFICANT AREA OF CIN AND CAPPING AT LEAST THROUGH 18Z MON. NAM HAS MINIMAL CIN AHEAD OF THE FRONT BUT THE QPF AND MOS POP VALUES ARE FLIPPED FROM WHAT ONE WOULD EXPECT GIVEN THE DIFFERENCES IN THE FORECAST SOUNDINGS. THAT IS...THE GFS IS MORE GENEROUS WITH THE QPF WHILE THE NAM GENERATES SOME SMALL RAINFALL AMOUNTS INTO N CENTRAL IL BOTH ONLY A FEW HUNDREDTHS AT MOST ACROSS THE REST OF THE FA...WITH MOS POPS IN LOWER END OF CHANCE CATEGORY AND GFS AT HIGH END. HAVE LOWERED POPS SLIGHTLY FOR MON THOUGH STILL LEFT AT VERY LOW END OF LIKELY WITH 55-60 PCT ACROSS THE FA. ZONAL FLOW SPREADS EASTWARD ACROSS THE ROCKIES AND GREAT PLAINS BY TUE...AND ACROSS THE MIDWEST AND GREAT LAKES BY WED BRINGING MILDER AND DRY AIR TO THE REGION. MODELS INDICATE A MINOR SHORT WAVE TO TRAVERSE THE DAKOTAS TUE NIGHT AND WED...AND THE UPPER MIDWEST WED NIGHT AND THU. THE SURFACE RIDGE THAT WILL BUILD IN BEHIND THE COLD FRONT IS PROGGED TO STILL HAVE ITS AXIS FROM QUEBEC SW BACK ACROSS THE GREAT LAKES AND TO THE MID MS VALLEY. THIS WOULD PLACE ANY THREAT OF RAIN WITH THIS DISTURBANCE TO THE N OF THE FA. UPPER RIDGING TO PUSH BACK NORTHEASTWARD ACROSS THE MIDWEST AND GREAT LAKES THU AND FRI AS AN UPPER TROUGH DEEPENS OVER FAR WESTERN NOAM. AFTER MAX TEMPS COOL TO THE 70S FOR A COUPLE DAYS AFTER THE COLD FRONTAL PASSAGE THEY CLIMB BACK INTO THE MID AND UPPER 80S FOR FRI AND NEXT WEEKEND WITH THE UPPER RIDGE BUILDING OVERHEAD. AREAS NEAR THE LAKE WILL BE COOLER FROM TUE INTO NEXT WEEKEND AS THE SURFACE HIGH BUILDING INTO THE REGION ALLOWS NNE FLOW TO TURN IN OFF OF THE LAKE TUE AND THEN WITH THE CENTER OF THE ANTICYCLONE MOVING OVER THE CENTRAL GREAT LAKES PROVIDES E TO SE LOW LEVEL FLOW OFF OF THE LAKE FROM WED ON. RIDGING SURFACE AND ALOFT TO KEEP AREA RAIN-FREE TUE THROUGH SAT...WITH ONLY SLIGHT CHANCES IN N CENTRAL IL ON SUN. WITH THE AREA NOT SEEING ANY LET ALONE SIGNIFICANT RAINFALL SINCE THE END OF MAY ANY AREAS THAT DO NOT GET ANY SIGNIFICANT RAIN WITH COLD FRONT WILL SEE MUCH GREATER MOISTURE DEFICITS AS NO ADDITIONAL THREAT OF SIGNIFICANT RAINS UNTIL AT LEAST LATE NEXT WEEKEND OR EARLY NEXT WORK WEEK. TRS && .FIRE WEATHER... 317 PM CDT WINDS AND RH VALUES APPROACHING BUT NOT EXPECTED TO REACH RED FLAG CRITERIA THE REST OF THE AFTERNOON OR EARLY THIS EVENING. TRS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * NO IMPACTS THROUGH 12Z. * TSRA POTENTIAL IN THE AFTERNOON HOURS. BEACHLER //DISCUSSION...UPDATED 06Z... LOW LEVEL HIGH PRESSURE HAS PUSHED FURTHER EAST OF THE REGION...ALLOWING A CONTINUED FEED OF SOUTHERLY WINDS OVER NORTHERN IL/NORTHWEST IN AIRFIELDS. A COLD FRONTAL BOUNDARY REMAINS WEST OF THE REGION...HOWEVER WILL CONTINUE TO SLOWLY PUSH EAST THROUGHOUT THE DAY TODAY. FRONTAL PASSAGE IS EXPECTED TO OCCUR DURING THE LATE AFTN/EVE HOURS. THEN WINDS VEER WEST/NORTHWEST DURING THE EVENING AND OVERNIGHT HOURS INTO TUE. THE OTHER CONCERN IS IN REGARDS TO TSRA DEVELOPMENT. GUIDANCE HAS STRUGGLED WITH THE PRECISE TIMING/PLACEMENT/INTENSITY...AND MANY THINGS STILL NEED TO COME TOGETHER. AT THIS TIME THE BEST TIMING IS FOR SHRA/TSRA DEVELOPMENT TO OCCUR DURING THE AFTN/EVE HOURS...THEN PUSH EAST INTO NORTHERN IN. AT THIS TIME GIVEN THE LOW CONFIDENCE HAVE MAINTAINED THE PROB30 GROUP...AND WILL ALLOW FOR FURTHER ADJUSTMENTS AS WE APPROACH THE LATE MORNING HOURS. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE IN ALL ELEMENTS THROUGH 16Z. * MEDIUM CONFIDENCE ON TSRA DEVELOPMENT AFT 16Z. * LOW CONFIDENCE ON COVERAGE OF TSRA. * HIGH CONFIDENCE IN WIND DIR/SPEED FORECAST. BEACHLER //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY THROUGH SATURDAY...VFR. RATZER && .MARINE... 300 AM CDT SURFACE HIGH PRESSURE CENTERED OVER THE SOUTHEAST COASTAL UNITED STATES WILL CONTINUE TO PUSH EAST...WHILE AN UPPER LEVEL TROUGH OF LOW PRESSURE PUSHES EAST ACROSS THE UPPER MIDWEST. ASSOCIATED WITH THE UPPER LEVEL SYSTEM WAS A COUPLE OF SURFACE LOW PRESSURES OVER CENTRAL AND SOUTHWEST ONTARIO. THESE LOW PRESSURE SYSTEMS WILL CONSOLIDATE ALLOWING FOR A TIGHTENING GRADIENT ALONG THE NORTHERN PORTION OF LAKE MICHIGAN FOR THE FIRST HALF OF TODAY...THEN THE GRADIENT WILL BEGIN TO SLACKEN MARGINALLY. SOUTHERLY FLOW WILL DOMINATE THE LAKE FOR TODAY...THEN AS A FRONTAL BOUNDARY SLOWLY APPROACHES FROM THE WEST WINDS WILL BEGIN TO TURN SOUTHWESTERLY. FRONTAL PASSAGE WILL BRING WEST AND EVENTUALLY NORTHWEST WINDS ACROSS THE LAKE. THE LOW PRESSURE SYSTEM OVER SOUTHERN HUDSON BAY WILL THEN DEEPEN...ALLOWING FOR AN INCREASED GRADIENT TO OCCUR ACROSS THE NORTHERN LAKES AND MAY STRETCH SOUTH ACROSS LAKE MICHIGAN TUE. OVERALL EXPECT WINDS TUE FROM A NORTHWEST/NORTH WIND TO BE 15 TO 25 KT. BROAD HIGH PRESSURE THEN BUILDS INTO THE GREAT LAKES REGION AND WILL PROVIDE MUCH LIGHTER WINDS FOR THE TUE NGT THROUGH THUR PERIODS. WINDS WILL MAINLY BE NORTH/NORTHEAST DURING THESE PERIODS. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
101 AM CDT MON JUN 11 2012 .DISCUSSION... 929 PM CDT SOME MINOR CHANGES MADE TO ARRIVAL TIMING OF POPS FOR MONDAY MORNING...OTHERWISE NO REAL CHANGES MADE TO GOING FORECAST FOR TONIGHT INTO MONDAY. EXPANSIVE UPPER LEVEL LOW AND ASSOCIATED HIGH PWAT AIR...AS SEEN ON WATER VAPOR...IS EXPANDING NORTHWARD. A WEAK UPPER LEVEL WAVE IN SOUTHWEST IL THIS EVE HAS HELPED TO SPREAD THIS NORTH CAUSING AN EXPANSION IN HIGH CLOUDS ACROSS THE AREA...WHICH SHOULD CONTINUE INTO OVERNIGHT. THESE CLOUDS ALONG WITH SOUTHERLY FLOW REMAINING AROUND 10 MPH TONIGHT SHOULD KEEP MINIMUM TEMPERATURES 3 TO 5 DEGREES WARMER THAN LAST NIGHT...WHICH IS RIGHT ON PAR WITH GOING FORECAST. LIGHT RETURNS ON THE KIND RADAR ARE INDICATIVE OF GRADUAL MID-LEVEL ASCENT AND SATURATION OCCURRING AHEAD OF THIS UPPER LOW. SATELLITE TRENDS AND GUIDANCE FORECASTS KEEP ALMOST ALL OF THIS ENTIRELY EAST OF THE AREA LATER TONIGHT INTO MONDAY MORNING. THE FEATURE WHICH WILL HAVE MORE INFLUENCE ON THE AREA IS A WELL- DEFINED UPPER LEVEL TROUGH ACROSS THE CANADIAN/U.S. HIGH PLAINS BORDER. IMPRESSIVE NORTH-TO-SOUTH LINE OF CONVECTION FROM NEAR INTERNATIONAL FALLS TO NORTHEAST KS HAS DEVELOPED JUST AHEAD OF THE SURFACE COOL FRONT WHERE CONVERGENCE WAS MAXIMIZED AND WITHIN A CORRIDOR OF HIGHER THETA-E RETURN. THE FRONT AND CONVECTION AHEAD OF IT WILL EVOLVE EAST INTO OVERNIGHT...LIKELY GRADUALLY TAPERING IN INTENSITY AND AT LEAST SOMEWHAT IN COVERAGE OVERNIGHT ACROSS IA AND NORTHERN MO. A PORTION OF THIS MAY MAKE IT INTO THE WESTERN FORECAST AREA IN THE EARLY MORNING...AND THE HRRR SOLUTION DEPICTS THIS...HOWEVER IT SEEMS TOO GENEROUS ON DEVELOPMENT OVERNIGHT IN THE ABSENCE OF MUCH OF A LOW-LEVEL JET/WAA. THE MID-LEVEL SHORT WAVE AXIS ACROSS EASTERN NE AND KS HELPING TO DRIVE SOME OF THE CONVECTION IS DEPICTED IN MOST GUIDANCE...AND TRACKS ACROSS THE FORECAST AREA DURING THE LATE MORNING AND AFTERNOON. COLLOCATED WITH THIS APPEARS TO BE A PRE-FRONTAL TROUGH...AT LEAST IN THE 925-700MB FLOW...WHICH HELPS IN FOCUSING SOME OF THE CONVERGENCE FIELDS. INSTABILITY VALUES ARE SIMILAR ON THE 11.00 NAM TO THOSE MENTIONED IN PRIOR DISCUSSION...SO SOME SCATTERED CONVECTION REGENERATING IN COVERAGE DURING THE MIDDAY TIME IS FAVORED AT THIS TIME. HAVE ADJUSTED MORNING POPS TO ACCOUNT FOR THIS TYPE OF TIMING/REASONING. AFTERNOON POPS STILL LOOK GOOD. MTF //PREV DISCUSSION... 317 PM CDT FOCUS OF FORECAST IS ON RAIN CHANCES MON AND MON EVE WITH A COLD FRONT MOVING ACROSS THE AREA...AND THEN ON THE VERY LOW...IF ANY...PROBABILITIES FOR RAIN THROUGH THE REST OF THE WORK WEEK AND WELL INTO NEXT WEEKEND. AN UPPER LOW OVER SOUTHERN SASKATCHEWAN AND NORTHEASTERN MT HAS CONTINUED TO BECOME SHEARED/ELONGATED TODAY...SLOWING ITS EASTWARD PROGRESS. AS A RESULT THE ASSOCIATED SURFACE LOW AND ATTENDANT COLD FRONT HAVE ALSO BEEN RELUCTANT TO MOVE EASTWARD WITH ANY VIGOR. MODELS SHOW THE UPPER LOW IS TO ACCELERATE NORTHEASTWARD LATER TODAY AND TONIGHT AS A SHORT WAVE AND JET MAX DIG SSE FROM THE YUKON-NW TERRITORIES BORDER TO SOUTHERN SASKATCHEWAN AND NE MT BY 12Z MON. THIS SHORT WAVE AND SPEED MAX ARE THEN PROGGED TO TURN SOUTHEASTERLY ACROSS THE DAKOTAS AND MN DURING THE DAY MON. WITH THE UPPER TROUGH BECOMING MORE PROGRESSIVE THE COLD FRONT...WHICH IS CURRENTLY LINGERING ACROSS NW AND W CENTRAL MN AND FAR SE SD AND NE NE... WILL ALSO START TO ACCELERATE EASTWARD...REACHING THE MID MS VALLEY BY EARLY MON AFTERNOON AND CONTINUING TO SE WI AND NE IL EARLY MON EVENING. CONVERGENCE ALONG THE COLD FRONT AS IT MOVES ACROSS THE LOCAL FORECAST AREA IS NOT VERY STRONG THOUGH TIMING OF THE FRONTAL PASSAGE DURING OR SOON AFTER PEAK HEATING LEADS TO IT OCCURRING WHEN INSTABILITY WILL BE MAXIMIZED WITH DEW POINTS SLOWLY CREEPING UP INTO THE 60S OVERNIGHT AND MON. HOWEVER...IF 10.12Z RUN OF GFS VERIFIES WITH THE LAYER FROM 2 TO 4K FT AGL SOME 3-4 DEG C WARMER THAN THE NAM SOLUTION DURING THE DAY MON THEN CONVECTIVE DEVELOPMENT AHEAD OF THE COLD FRONT WILL BE INHIBITED BY THE WARMTH ALOFT MAINTAINING A SIGNIFICANT AREA OF CIN AND CAPPING AT LEAST THROUGH 18Z MON. NAM HAS MINIMAL CIN AHEAD OF THE FRONT BUT THE QPF AND MOS POP VALUES ARE FLIPPED FROM WHAT ONE WOULD EXPECT GIVEN THE DIFFERENCES IN THE FORECAST SOUNDINGS. THAT IS...THE GFS IS MORE GENEROUS WITH THE QPF WHILE THE NAM GENERATES SOME SMALL RAINFALL AMOUNTS INTO N CENTRAL IL BOTH ONLY A FEW HUNDREDTHS AT MOST ACROSS THE REST OF THE FA...WITH MOS POPS IN LOWER END OF CHANCE CATEGORY AND GFS AT HIGH END. HAVE LOWERED POPS SLIGHTLY FOR MON THOUGH STILL LEFT AT VERY LOW END OF LIKELY WITH 55-60 PCT ACROSS THE FA. ZONAL FLOW SPREADS EASTWARD ACROSS THE ROCKIES AND GREAT PLAINS BY TUE...AND ACROSS THE MIDWEST AND GREAT LAKES BY WED BRINGING MILDER AND DRY AIR TO THE REGION. MODELS INDICATE A MINOR SHORT WAVE TO TRAVERSE THE DAKOTAS TUE NIGHT AND WED...AND THE UPPER MIDWEST WED NIGHT AND THU. THE SURFACE RIDGE THAT WILL BUILD IN BEHIND THE COLD FRONT IS PROGGED TO STILL HAVE ITS AXIS FROM QUEBEC SW BACK ACROSS THE GREAT LAKES AND TO THE MID MS VALLEY. THIS WOULD PLACE ANY THREAT OF RAIN WITH THIS DISTURBANCE TO THE N OF THE FA. UPPER RIDGING TO PUSH BACK NORTHEASTWARD ACROSS THE MIDWEST AND GREAT LAKES THU AND FRI AS AN UPPER TROUGH DEEPENS OVER FAR WESTERN NOAM. AFTER MAX TEMPS COOL TO THE 70S FOR A COUPLE DAYS AFTER THE COLD FRONTAL PASSAGE THEY CLIMB BACK INTO THE MID AND UPPER 80S FOR FRI AND NEXT WEEKEND WITH THE UPPER RIDGE BUILDING OVERHEAD. AREAS NEAR THE LAKE WILL BE COOLER FROM TUE INTO NEXT WEEKEND AS THE SURFACE HIGH BUILDING INTO THE REGION ALLOWS NNE FLOW TO TURN IN OFF OF THE LAKE TUE AND THEN WITH THE CENTER OF THE ANTICYCLONE MOVING OVER THE CENTRAL GREAT LAKES PROVIDES E TO SE LOW LEVEL FLOW OFF OF THE LAKE FROM WED ON. RIDGING SURFACE AND ALOFT TO KEEP AREA RAIN-FREE TUE THROUGH SAT...WITH ONLY SLIGHT CHANCES IN N CENTRAL IL ON SUN. WITH THE AREA NOT SEEING ANY LET ALONE SIGNIFICANT RAINFALL SINCE THE END OF MAY ANY AREAS THAT DO NOT GET ANY SIGNIFICANT RAIN WITH COLD FRONT WILL SEE MUCH GREATER MOISTURE DEFICITS AS NO ADDITIONAL THREAT OF SIGNIFICANT RAINS UNTIL AT LEAST LATE NEXT WEEKEND OR EARLY NEXT WORK WEEK. TRS && .FIRE WEATHER... 317 PM CDT WINDS AND RH VALUES APPROACHING BUT NOT EXPECTED TO REACH RED FLAG CRITERIA THE REST OF THE AFTERNOON OR EARLY THIS EVENING. TRS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * NO IMPACTS THROUGH 12Z. * TSRA POTENTIAL IN THE AFTERNOON HOURS. BEACHLER //DISCUSSION...UPDATED 06Z... LOW LEVEL HIGH PRESSURE HAS PUSHED FURTHER EAST OF THE REGION...ALLOWING A CONTINUED FEED OF SOUTHERLY WINDS OVER NORTHERN IL/NORTHWEST IN AIRFIELDS. A COLD FRONTAL BOUNDARY REMAINS WEST OF THE REGION...HOWEVER WILL CONTINUE TO SLOWLY PUSH EAST THROUGHOUT THE DAY TODAY. FRONTAL PASSAGE IS EXPECTED TO OCCUR DURING THE LATE AFTN/EVE HOURS. THEN WINDS VEER WEST/NORTHWEST DURING THE EVENING AND OVERNIGHT HOURS INTO TUE. THE OTHER CONCERN IS IN REGARDS TO TSRA DEVELOPMENT. GUIDANCE HAS STRUGGLED WITH THE PRECISE TIMING/PLACEMENT/INTENSITY...AND MANY THINGS STILL NEED TO COME TOGETHER. AT THIS TIME THE BEST TIMING IS FOR SHRA/TSRA DEVELOPMENT TO OCCUR DURING THE AFTN/EVE HOURS...THEN PUSH EAST INTO NORTHERN IN. AT THIS TIME GIVEN THE LOW CONFIDENCE HAVE MAINTAINED THE PROB30 GROUP...AND WILL ALLOW FOR FURTHER ADJUSTMENTS AS WE APPROACH THE LATE MORNING HOURS. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE IN ALL ELEMENTS THROUGH 16Z. * MEDIUM CONFIDENCE ON TSRA DEVELOPMENT AFT 16Z. * LOW CONFIDENCE ON COVERAGE OF TSRA. * HIGH CONFIDENCE IN WIND DIR/SPEED FORECAST. BEACHLER //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY THROUGH SATURDAY...VFR. RATZER && .MARINE... 202 PM...SOUTHERLY FLOW WILL CONTINUE THROUGH MONDAY AFTERNOON UNTIL A COLD FRONT MOVES ACROSS LAKE MICHIGAN MONDAY EVENING. A LARGE AREA OF LOW PRESSURE OVER SOUTHERN CANADA WILL EVENTUALLY CONSOLIDATE INTO ONE LOW AND SLOWLY LIFT NORTHEAST TO HUDSON BAY MONDAY. THE GRADIENT IS STILL EXPECTED TO TIGHTEN SOME... ESPECIALLY OVER THE NORTHERN PORTION OF THE LAKE WHERE 15-25KTS IS POSSIBLE. WINDS WILL SLOWLY DIMINISH AHEAD OF THE FRONT AND THEN SHIFT NORTHWEST BEHIND THE FRONT MONDAY EVENING INTO MONDAY NIGHT. HIGH PRESSURE BUILDS ACROSS THE PLAINS TUESDAY...MAINTAINING A NORTHWESTERLY FLOW ACROSS THE LAKE AND AS THE HIGH SPREADS EAST IN THE AFTERNOON...EXPECT THE GRADIENT TO WEAKEN ENOUGH FOR A LAKE BREEZE TO FORM ACROSS NORTHEAST IL AND NORTHWEST INDIANA. THE HIGH WILL MOVE ACROSS THE LAKES REGION TUESDAY NIGHT INTO WEDNESDAY WITH LIGHT WINDS BECOMING SOUTHERLY THURSDAY AS THE HIGH DEPARTS. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1109 PM CDT SUN JUN 10 2012 .DISCUSSION... ISSUED 852 PM CDT SUN JUN 10 2012 LATEST SURFACE ANALYSIS INDICATES THE COLD FRONT WHICH WILL AFFECT OUR AREA ON MONDAY WAS LOCATED OVER EXTREME WESTERN IOWA EARLY THIS EVENING. CONVECTION HAS BEEN ORGANIZING ALONG AND JUST TO THE EAST OF THE FRONT OVER THE PAST SEVERAL HOURS AND SEEMS TO BE GETTING BETTER ORGANIZED...ESPECIALLY ACRS SOUTHWEST IOWA INTO SE NEBRASKA WHERE THE CONVERGENCE WAS MOST PRONOUNCED OVER THE PAST SEVERAL HOURS. SHORT TERM MODELS CONTINUE TO SUGGEST THE CONVECTION WILL PUSH EAST AND SOUTHEAST THRU IOWA AND INTO NORTHERN MISSOURI LATE THIS EVENING AND INTO THE EARLY MORNING HOURS WITH A GRADUAL WEAKENING TREND AS IT TRACKS TO EXTREME EASTERN IOWA AND NE MISSOURI TOWARDS 300 AM...AND POSSIBLY INTO PARTS OF WEST CENTRAL IL JUST BEFORE DAWN. THE 00Z ILX AND SGF SOUNDINGS SHOWING A FAIRLY STRONG CAP IN PLACE EARLY THIS EVENING WITH OUR AREAS IN BETWEEN THE BETTER MOISTURE SOURCES...WITH THE DEEP TROPICAL MOISTURE ASSOCIATED WITH THE SOUTHERN MISSISSIPPI VALLEY UPPER WAVE MAINLY ACRS THE EAST AND SE SECTIONS OF OUR FORECAST AREA...AND THE BETTER LOW LEVEL MOISTURE AHEAD OF THE FRONT LOCATED IN A NARROW SW-NE CORRIDOR JUST AHEAD OF THE COLD FRONT. THE BETTER INSTABILITY FROM THE SPC MESOANALYSIS WAS LOCATED ACROSS PARTS OF SOUTHWEST IOWA INTO EASTERN KS AND NW MO WHERE SURFACE BASE CAPES WERE IN THE 2500 TO 3000 J/JG OVER THE PAST HOUR WITH THE ELEVATED MIXED LAYER STARTING TO ERODE THANKS TO THE INCREASING SFC MOISTURE CONVERGENCE AND JET DYNAMICS. PROPAGATION VECTORS SUGGEST THE MORE ORGANIZED CONVECTION MAY START TO TURN SE INTO PARTS OF NW MO AND NE KS EARLY THIS EVENING AS THE NORTHERN PORTION OF THE CONVECTION WEAKENS SOME AS IT TRACKS FURTHER EAST. THIS TYPE OF SCENARIO DOES NOT BODE WELL WITH RESPECT TO SEEING SOME DECENT RAINFALL ACRS OUR AREA ON MONDAY. WHAT IS LEFT OF THE CONVECTION WILL PUSH ACRS WESTERN IL DURING THE MORNING AND POSSIBLY REDEVELOP ALONG OR EAST OF THE I-55 CORRIDOR DURING THE AFTERNOON AS THE COLD FRONT APPROACHES THE AREA. UPPER LEVEL SUPPORT AS WELL AS ANY LOW LEVEL CONVERGENCE DOES NOT LOOK THAT GREAT FOR ANY SIGNIFICANT ORGANIZATION TO THE CONVECTION TOMORROW AHEAD OF THE COLD FRONT...DESPITE THE MODERATE INSTABILITY SEEN ON MODELS...NEVER THE LESS...WE SHOULD SEE AT LEAST SOME SCATTERED SHOWERS AND THUNDERSTORMS ACRS THE AREA DURING THE DAY BUT THIS CERTAINLY DOESN`T LOOK LIKE IT WILL PRODUCE WIDESPREAD RAINFALL...WHICH WE DESPERATELY NEED. THE CURRENT ZONE FORECAST IS IN GOOD SHAPE THIS EVENING...SO OTHER THAN THE USUAL EARLY EVENING TWEAKS TO THE HOURLY TEMPERATURE GRIDS...NO OTHER ADJUSTMENTS WILL BE NEEDED...AS A RESULT NO ZONE UPDATE WILL BE NEEDED. && .AVIATION... ISSUED 1105 PM CDT SUN JUN 10 2012 LOOKING AT MAINLY VFR CONDITIONS THRU THIS FORECAST PERIOD. STILL SOME QUESTIONS WITH RESPECT TO TIMING OF CONVECTION...OR WHAT IS LEFT OF THE CONVECTION CURRENTLY GOING ACRS CENTRAL IOWA AND ANY AFFECT ON CIGS ACRS OUR AREA TOMORROW MORNING. TIMING OF PRECIP STILL LOOKS TO BE IN THE 10Z-14Z TIME FRAME ACRS THE WEST BEFORE DISSIPATING. MAY SEE SOME RE-DEVELOPMENT ALONG OR JUST EAST OF I-55 BETWEEN 18Z-22Z WITH COVERAGE STILL LIMITED ENOUGH TO CONTINUE WITH VCTS. ANY CONVECTION THAT DOES FORM LATE TOMORROW MORNING OR EARLY AFTN SHOULD PUSH EAST OF THE TAF SITES BY 00Z WITH THE ACTUAL COLD FRONT LAGGING SEVERAL HOURS BEHIND THE PRECIP. SURFACE WINDS WILL CONTINUE FROM A SE DIRECTION OVERNIGHT AT 5 TO 10 KTS...AND THEN WINDS WILL BEGIN TO VEER MORE INTO THE SOUTHWEST TOMORROW WITH SPEEDS RUNNING FROM 10 TO 15 KTS. THE WIND WILL SHIFT INTO THE WEST LATE TOMORROW AFTN AND EVENING AS THE FRONT EDGES ACRS THE FORECAST AREA. SMITH && .PREV DISCUSSION... ISSUED 257 PM CDT SUN JUN 10 2012 SHORT TERM...TONIGHT THROUGH WEDNESDAY UPPER-LEVEL DISTURBANCE CURRENTLY OVER THE LOWER MISSISSIPPI RIVER VALLEY WILL CONTINUE TO SPREAD MOISTURE NORTHWARD INTO THE REGION TONIGHT. LATEST SATELLITE/RADAR LOOPS INDICATE THE DEEPER MOISTURE AND ASSOCIATED PRECIP ARE PRIMARILY LIMITED TO LOCATIONS ALONG AND TO THE RIGHT OF THIS FEATURE. AS A RESULT...THE BEST RAIN CHANCES WILL SPREAD INTO THE TENNESSEE AND OHIO RIVER VALLEYS TONIGHT...GENERALLY STAYING EAST OF ILLINOIS. HIGH-RES MODELS SUCH AS THE HRRR ARE KEEPING THE KILX CWA DRY...HOWEVER WITH DEEPER MOISTURE COMING SO CLOSE TO THE E/SE...HAVE OPTED TO MAINTAIN A SLIM CHANCE FOR SHOWERS ALONG/EAST OF I-57 TONIGHT. MEANWHILE...VIGOROUS UPPER WAVE OVER THE NORTHERN ROCKIES WILL TRACK ALONG THE CANADIAN BORDER TOWARD THE NORTHERN GREAT LAKES BY MONDAY EVENING. TRAILING COLD FRONT WILL CROSS THE MISSISSIPPI RIVER BY AROUND MIDDAY MONDAY AND BE LOCATED ALONG THE I-55 CORRIDOR BY EARLY MONDAY EVENING. AIRMASS AHEAD OF THE FRONT WILL BECOME MODERATELY UNSTABLE...CHARACTERIZED BY CAPE VALUES OF 1500 TO 2500J/KG. MITIGATING FACTOR FOR WIDESPREAD THUNDERSTORMS AND SEVERE POTENTIAL WILL BE LACK OF WIND SHEAR. FORECAST SOUNDINGS INDICATE WEAK WIND PROFILE THROUGHOUT THE ENTIRE DEPTH OF THE ATMOSPHERE AND VERY WEAK 0-6 KM BULK SHEAR VALUES OF 15 TO 25KT. DESPITE LACK OF SHEAR...ADEQUATE INSTABILITY AND GOOD CONVERGENCE ALONG THE ADVANCING FRONT WILL RESULT IN A BROKEN LINE OF STORMS...WITH A LOW PROBABILITY FOR SEVERE. PRIMARY TIME FRAME WILL BE DURING THE LATE MORNING/AFTERNOON WEST OF I-55...AND DURING THE EVENING FURTHER EAST. ANY CONVECTION WILL QUICKLY EXIT INTO INDIANA AFTER MIDNIGHT...WITH CLEARING SKIES NOTED FROM WEST TO EAST ACROSS THE AREA TOWARD DAWN. HIGH PRESSURE WILL BUILD INTO THE GREAT LAKES BEHIND THE DEPARTING COLD FRONT ON TUESDAY AND WEDNESDAY...BRINGING A COOLER/DRIER AIRMASS INTO THE REGION. WITH 850MB TEMPS PROGGED TO DROP INTO THE 12 TO 14C RANGE...HIGHS WILL FALL BACK TO NEAR NORMAL FOR THIS TIME OF YEAR IN THE UPPER 70S/LOWER 80S. LONG TERM...THURSDAY THROUGH SUNDAY MODELS CONTINUE TO ADVERTISE UPPER TROUGHING DEVELOPING ACROSS THE WESTERN CONUS BY THE END OF THE WEEK...RESULTING IN DOWNSTREAM RIDGING AND WARMER WEATHER FOR THE MIDWEST. EXACT EVOLUTION AND DEGREE OF AMPLIFICATION STILL REMAIN IN QUESTION...WITH A SLIGHTLY DIFFERENT SOLUTION FEATURED ON EACH SUCCESSIVE MODEL RUN. GIVEN UNCERTAINTIES...HAVE OPTED TO MAINTAIN A DRY FORECAST THROUGH NEXT WEEKEND EVEN THOUGH THE ECMWF SUGGESTS A FRONT MAY APPROACH FROM THE NORTHWEST BY SUNDAY. 12Z 10 JUN GFS IS MUCH STRONGER WITH THE EASTERN RIDGE AND DEVELOPS A REX BLOCK ACROSS THE GREAT LAKES/OHIO RIVER VALLEY. IF THIS SOLUTION PANS OUT...THE NEXT CHANCE FOR RAIN WOULD BE DELAYED PERHAPS UNTIL THE MIDDLE OF NEXT WEEK. WILL THEREFORE MAINTAIN WARM/DRY CONDITIONS THROUGH SUNDAY...UNTIL BETTER MODEL CONSISTENCY IS ACHIEVED. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1230 AM EDT MON JUN 11 2012 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 308 PM EDT SUN JUN 10 2012 AN UPPER SYSTEM WILL MOVE SOUTHEAST OF THE AREA ON MONDAY BRINGING SOME RAIN TO THE AREA...THEN A COLD FRONT WILL MOVE THROUGH ON MONDAY NIGHT BRINGING ADDITIONAL CHANCES FOR RAIN. HIGH PRESSURE WILL THEN BUILD IN AND DRY WEATHER INTO NEXT WEEKEND. && .NEAR TERM /OVERNIGHT/... ISSUED AT 940 PM EDT SUN JUN 10 2012 MID AND HIGH LEVEL CLOUDS ASSOCIATED WITH THE UPPER LEVEL DISTURBANCE OVER THE TENNESSEE VALLEY CONTINUING TO SPREAD INTO THE REGION THIS EVENING. HAVE SEEN A FEW SPRINKLES/VERY LIGHT RAIN SHOWERS MOVING NORTH THROUGH SOUTHERN FORECAST AREA. TEMPS WERE IN THE UPPER 70S AND LOWER 80S AT 01Z. NOT MUCH CHANGE TO CURRENT FORECAST FOR THE OVERNIGHT. ONLY EXCEPTION WILL BE TO MAKE SOME REFINEMENTS TO POPS BASED ON RADAR AND SATELLITE TRENDS AND SUPPORTED BY MOST RECENT SHORT RANGE MODEL GUIDANCE. GREATER COVERAGE TO RAINFALL ASSOCIATED WITH THE UPPER DISTURBANCE FROM MIDDLE TENNESSEE SOUTH INTO ALABAMA/GEORGIA CURRENTLY. RAP APPEARS TO CAPTURE THIS ACTIVITY WELL THIS EVENING...TRACKING IT N/NE OVERNIGHT AND INTO THE OHIO VALLEY TOWARDS DAYBREAK. WILL CONTINUE WITH LIKELY POPS OVER FAR SOUTHEAST COUNTIES WHERE CONFIDENCE IS HIGHEST IN MEASURABLE PRECIP LATE. DROPPED BACK TO LOW CHANCE POPS FURTHER NORTH AND WEST OVER MUCH OF THE REMAINDER OF THE FORECAST AREA. ALSO REMOVED ISOLATED THUNDER FROM ALL BUT FAR SOUTHEAST COUNTIES WITH ONLY WEAK ELEVATED CAPE VALUES PRESENT AND LITTLE IN THE WAY OF LIGHTNING STRIKES WITH PRECIP SHIELD TO OUR SOUTH. ZONE AND GRID UPDATES OUT SHORTLY. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... ISSUED AT 308 PM EDT SUN JUN 10 2012 FOCUS IS ON RAIN CHANCES EARLY IN THE PERIOD. NAM IS A LITTLE STRONGER THAN THE OTHER MODELS AND STANDS OUT...SO WENT CLOSER TO GFS/ECMWF. UPPER SYSTEM TO OUR EAST WILL STILL BE CLOSE ENOUGH FOR LOW END LIKELY POPS MONDAY MORNING ACROSS THE EAST AND CHANCE POPS ELSEWHERE. THEN FOR THE AFTERNOON THE FORECAST AREA WILL BE IN BETWEEN THE EASTERN SYSTEM AND A COLD FRONT APPROACHING FROM THE WEST. THUS WENT CHANCE POPS ALL AREAS DURING THE AFTERNOON. THE FRONT WILL MOVE IN MONDAY NIGHT...BUT BY THEN TIMING IS NOT FAVORABLE AS INSTABILITY WILL BE DIMINISHING. THUS AGAIN ONLY WENT CHANCE POPS DURING THE EVENING...DECREASING OVERNIGHT. ONLY KEPT SLIGHT CHANCE POPS IN THE FAR EAST ON TUESDAY TO ACCOUNT FOR ANY LINGERING SHOWERS BEHIND THE FRONT...BUT THIS WILL PROBABLY BE ABLE TO BE REMOVED IF CURRENT MODEL TRENDS CONTINUE. DRY CONDITIONS WILL THEN MOVE IN THROUGH WEDNESDAY AS HIGH PRESSURE MOVES IN. AS FAR AS TEMPERATURES ARE CONCERNED...WENT CLOSER TO THE WARMER MAV ON MONDAY AS NOTED ABOVE MOST OF THE AREA WILL BE IN BETWEEN SYSTEMS DURING THE DAY. STUCK CLOSE TO MODEL BLEND FOR MUCH OF THE REST OF THE PERIOD. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... ISSUED AT 308 PM EDT SUN JUN 10 2012 HIGH PRESSURE OVER THE GREAT LAKES WILL SLOWLY MAKES ITS WAY TOWARDS NEW ENGLAND KEEPING CONDITIONS DRY THROUGHOUT THE PERIOD. THE GFS AND CANADIAN DEPICT A WEAK WAVE AND ASSOCIATED VORT MAX POSSIBLY IMPACTING THE AREA ON SUNDAY. HOWEVER...MODELS CURRENTLY INDICATE PRECIPITATION CHANCES NOT EXPECTED TO IMPACT THE AREA UNTIL SUNDAY NIGHT AT THE EARLIEST. THEREFORE...REMOVED ALLBLEND SLIGHT CHANCE POPS AND CONTINUED WITH AN ENTIRELY DRY FORECAST FOR THE LONG TERM. TEMPERATURES WILL START OUT NEAR NORMAL VALUES AND GRADUALLY INCREASE THROUGHOUT THE PERIOD ALLOWING ABOVE NORMAL VALUES TO RETURN. && .AVIATION /DISCUSSION FOR THE 110600Z TAFS/... ISSUED AT 1230 AM EDT MON JUN 11 2012 EXPECTING CEILINGS TO FALL INTO THE 040-050 RANGE DURING THE PRE DAWN HOURS AS DEEPER MOISTURE CONTINUES TO ADVECT INTO THE AREA. UPPER DISTURBANCE CURRENTLY OVER THE TENNESSEE VALLEY EXPECTED TO DRIFT NORTHEAST INTO THE LOCAL AREA AFTER SUNRISE ON MONDAY. LIFT LOOKS RATHER DISORGANIZED WITH THIS SYSTEM WITH 850MB WINDS GENERALLY WEAK. SOME SCATTERED SHOWER ACTIVITY POSSIBLE AFTER SUNRISE ON MONDAY...ESPECIALLY IN THE VICINITY OF KIND/KBMG...BUT WITH THE DISORGANIZED LIFT...ONLY MVFR VISIBILITY RESTRICTIONS EXPECTED IN ANY SHOWERS. HEATING OF THE MOIST BOUNDARY LAYER MAY RESULT IN SOME AREAS OF MVFR CEILINGS AFTER SUNRISE AS WELL. A BETTER THREAT FOR ORGANIZED CONVECTION MAY DEVELOP OVER THE TAF SITES AFTER ABOUT 112000Z WITH THE APPROACH OF A FRONTAL ZONE/UPPER TROUGH FROM THE WEST. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...50 NEAR TERM...RYAN SHORT TERM...50 LONG TERM....HOMANN/50 AVIATION...JAS/JP
AREA FORECAST DISCUSSION
NWS TOPEKA KS
326 AM CDT MON JUN 11 2012 .DISCUSSION... STRONG MOISTURE CONVERGENCE CONTINUES IN FAR NORTHEAST KANSAS BEHIND SURFACE FRONT...WHICH LIES FROM ROUGHLY FROM KDSM TO KTOP TO KWLD AT 08Z. GUSTY NORTHEAST WINDS WERE REPORTED AT KMHK AT 08Z WITH OUTFLOW BOUNDARY SHOWING NEAR THE KTWX RADAR. MUCH DRIER AIR NOT FAR BEHIND WITH SURFACE DEWPOINTS IN THE UPPER 40S IN NORTH CENTRAL KANSAS AND LOWER 30S IN NORTHWEST KANSAS. WEAK MID LEVEL RETURNS SHOWING UP ON WESTERN KANSAS RADARS BUT LITTLE NEARING THE SURFACE IN MID LEVEL FRONTOGENESIS. 0Z 850MB TEMPS WERE VERY CLOSE TO 20C THROUGHOUT THE SURROUNDING STATES...THOUGH TEMPS BELOW 10C WERE SAMPLED IN MONTANA. WILL GO ALONG WITH HRRR AND RUC WITH CONVECTION SLOWLY PUSHING SOUTHEAST OUT OF THE AREA THIS MORNING AS THE MODIFIED CONTINENTAL AIRMASS MOVES IN. WESTERN MID LEVEL RETURNS SHOULD ENCOUNTER THIS DRIER AIR AND STILL STRUGGLE TO REACH THE GROUND. COLD AIR ADVECTION TAKES ITS TIME GETTING HERE HOWEVER...WITH SOMEWHAT INCREASED LEVELS COMING LATE IN THE DAY. WITH SOME EARLY DAY HIGH CLOUD AS WELL...THIS MAY KEEP NORTHERN AREAS IN THE MID 80S...WITH SOME UPPER 80S ALONG I-70 WHERE EARLY DAY DEBRIS IS MORE REMOVED AND BETTER CALL WILL HOLD OFF LONGER. TONIGHT INTO TUESDAY PERIODS LOOK RATHER QUIET WITH SURFACE HIGH PASSING ACROSS NEBRASKA AND IOWA AND 700-850MB RIDGING OVER EASTERN KANSAS. MAY SEE SOME HIGH CLOUD MOVE OUT OF THE ROCKIES TUESDAY WITH HIGHS A LITTLE COOLER THAN TODAY. MODELS HAVE BEEN FAIRLY CONSISTENT WITH A WEAK UPPER WAVE MOVING THROUGH LATE TUESDAY NIGHT INTO WEDNESDAY EVENING. SOUTHERLY LOW/MID LEVEL FLOW WILL SLOWLY INCREASE RESULTING IN WEAK ISENTROPIC LIFT WHILE PRECIPITABLE WATER VALUES RISE TO AROUND 1.3 INCHES BY LATE WEDNESDAY. COMBINED FORCING AND DEEPER MOISTURE MAY BE ENOUGH FOR SOME CONVECTION...THOUGH COVERAGE IS MUCH IN QUESTION AT THIS POINT. WILL KEEP POPS ON THE LOW SIDE WEDNESDAY AND WEDNESDAY NIGHT...KEEPING TUESDAY NIGHT DRY AT THIS POINT. WEAK MID LEVEL LAPSE RATES SHOULD KEEP STRONG INSTABILITY IN CHECK. WARM AND HUMID CONDITIONS TO RULE MUCH OF THE EXTENDED PERIODS WITH LITTLE CHANGE IN AIRMASS FROM THE AFOREMENTIONED SITUATION. FAIRLY GOOD MODEL AGREEMENT WITH WEAK UPPER RIDGE FROM THE SOUTHERN PLAINS INTO THE GREAT LAKES THROUGH AT LEAST SATURDAY AND STRONG FORCING MECHANISM APPEAR LACKING...BUT ALSO LACKING IS STRONG CAPPING. SMALL PRECIPITATION CHANCES...NEAR CLIMATOLOGICAL VALUES FOR MID JUNE... WILL BE KEPT FOR THE BULK OF THESE PERIODS WITH TEMPS SOMEWHAT ABOVE NORMAL. 65 && .AVIATION... PRIMARY UPPER LEVEL FORCING SHOULD EXIT THE AREA BY 06Z TAKING THE MAJORITY OF THE CONVECTION WITH IT SO HAVE WENT WITH A DRY FCST AT ALL TAFS SITES. HOWEVER...OUTFLOW BOUNDARY MAY STILL SERVE TO DEVELOP SOME ISOLATED CONVECTION BEFORE 09Z...BUT CHANCES APPEAR TOO LOW TO INCLUDE IN THE TERMINAL FCSTS. FRONT AND OUTFLOW COMBINATION WILL KEEP NORTH/NORTH WINDS THROUGH 12Z AND THEN INCREASE SLIGHTLY. ONLY SCT-BKN STRATOCU THROUGH 12Z THEN A FEW AC BEYOND 12Z. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS JACKSON KY
140 AM EDT MON JUN 11 2012 .UPDATE... ISSUED AT 140 AM EDT MON JUN 11 2012 WELL...RADAR CONTINUES TO PAINT LIGHT RETURNS ACROSS OUR SWRN COUNTIES BUT IT STILL APPEARS THAT VERY LITTLE OF THIS IS REACHING THE GROUND. MODELS CONTINUE TO RUN AMUCK WITH PRECIP OVERNIGHT BUT GENERALLY APPEAR TO BE OVER DOING THINGS BASED ON CURRENT OBS/TRENDS. WILL GO AHEAD AND SCALE POPS BACK A BIT FOR THE NEXT FEW HOURS BUT WILL ALSO KEEP SOME CHANCES IN FOR AROUND DAYBREAK. UPDATE ISSUED AT 1036 PM EDT SUN JUN 10 2012 LATEST NAM AND RUC HAVE REALLY BACKED OFF ON PRECIPITATION ACROSS SOUTHEAST KENTUCKY THROUGH THE REMAINDER OF THE NIGHT. THIS MAY BE DUE TO THE CONTINUED DOWNSLOPING (DRYING) FLOW. IF THIS IS THE CASE...MUCH OF THE AREA MAY GET ROBBED OVERNIGHT. HOWEVER...AREAS ALONG AND NORTH OF THE MOUNTAIN PARKWAY MAY NOT FEEL THIS INFLUENCE AS MUCH WITH DEWPOINTS POOLING A BIT HIGHER ACROSS THE AREA. THUS...THE NAM DEPICTION OF A BAND OF PRECIPITATION FORMING ACROSS OUR NORTH SEEMS REASONABLE AND WILL DRIFT NORTH TOWARDS DAYBREAK INTO NORTHERN KENTUCKY. MEANWHILE...LOW LEVEL JET WILL LIKELY BLOSSOM AN AREA OF SHOWERS ACROSS CENTRAL TENNESSEE LATE TONIGHT AND THESE WILL LIKELY PUSH NORTH ALONG THE I-75 CORRIDOR THROUGH DAYBREAK AND BEYOND. AGAIN...NOT SURE HOW MUCH INFLUENCE COULD BE ATTRIBUTED TO THE DOWNSLOPING FLOW...BUT THE EVOLUTION OF THIS SYSTEM WILL NEED TO BE WATCHED AS IT TOO COULD FALL APART AND BECOME MORE SCATTERED SHOWERS OR SPRINKLES AT BEST. REGARDLESS...STILL A BIT OF A CHANCE WE COULD END UP STAYING DRY IN SEVERAL AREAS THROUGH DAYBREAK AND PERHAPS WELL INTO MONDAY AS WELL. UPDATE ISSUED AT 806 PM EDT SUN JUN 10 2012 LOOKING AT ALL AVENUES IN WHICH WE COULD ACHIEVE THUNDER TONIGHT CAME BACK NEGATIVE. LIFTING PARCELS FROM MANY DIFFERENT LEVELS COULD NOT GENERATE ENOUGH INSTABILITY TO WARRANT THUNDER LATE TONIGHT. THIS IS SUPPORTED BY THE LACK OF LIGHTNING UPSTREAM. ALTHOUGH WE ARE ANTICIPATING NEW DEVELOPMENT...IT WILL LIKELY TRANSITION INTO MORE RAIN SHOWERS. IT WOULD TAKE SOME PRETTY VIGOROUS UPDRAFTS TO GET MOISTURE ABOVE THE VERY HIGH FREEZING LEVEL...THUS...FEEL SAFE REMOVING THUNDER. STILL NOT CONFIDENT TO GO ANY HIGHER WITH POPS...BUT WE MAY NEED TO GO HIGHER WITH A LATER UPDATE IF THINGS BEGIN TO DEVELOP AS EXPECTED. HOWEVER...AT THIS TIME...PREFER TO WAIT AND SEE AND STICK WITH OUR 60 TO 70 POPS. IT STILL LOOKS LIKE SHOWERS SHOULD BEGIN TO DEVELOP NEAR THE TENNESSEE BORDER AROUND 1 OR 2 AM...THEN SPREAD NORTHWARD...REACHING THE I-64 CORRIDOR BY 4 OR 5 AM...AND INTO NORTHERN KENTUCKY AROUND DAYBREAK. AFTER THE INITIAL SURGE OF MOISTURE AND RAIN...IT APPEARS WE COULD DRY OUT BEHIND THIS FEATURE TOMORROW MORNING...LEADING TO A DRIER PERIOD DURING THE MID MORNING HOURS. THEN WE MAY HAVE TO WAIT FOR DAYTIME INSTABILITY TO REFIRE THINGS IN THE AFTERNOON IF WE DON`T HAVE TOO MANY CLOUDS AROUND TO PREVENT THE DEVELOPMENT OF INSTABILITY. REGARDLESS...STILL PLENTY OF QUESTIONS SWIRLING AROUND TOMORROW`S FORECAST. GOING TO HOLD OFF TO MAKE ANY CHANGES AS MUCH WILL BE DETERMINED IN THE NEXT 6 TO 12 HOURS. UPDATE ISSUED AT 524 PM EDT SUN JUN 10 2012 DECIDED TO INTRODUCE A FEW HOURS OF SPRINKLES FOR AREAS SOUTH OF THE HAL ROGERS PARKWAY FOR THIS EVENING. CEILINGS ARE AROUND 5KFT...SO I IMAGINE A FEW DROPS ARE MAKING IT TO THE SURFACE. STILL LOOKS LIKE THE BEST FORCING WITH THE MAIN PRECIPITATION WILL HOLD OFF UNTIL AROUND OR SHORTLY AFTER MIDNIGHT. THE TARGETED AREAS EARLY...WILL BE NEAR THE TENNESSEE BORDER WITH THE THREAT FOR RAIN PUSHING INTO NORTHERN KENTUCKY TOWARDS DAYBREAK. DOWNSLOPING MAY KEEP INITIAL PRECIPITATION TOTALS ON THE LIGHT SIDE AND PERHAPS NOT EVEN MEASURABLE ACROSS SOUTHEAST KENTUCKY...BUT EVENTUALLY THE FORCING SHOULD WIN OUT. LOWER CLOUD DECK HAS BROUGHT SOME EARLIER COOLING INTO OUR SOUTHERN COUNTIES...SO HAVE ADJUSTED THE HOURLY TEMPERATURE TRACE TO REFLECT THIS EARLIER COOLING. NO NEED TO UPDATE ZONES WITH ANY OF THESE CHANGES. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 259 PM EDT SUN JUN 10 2012 EASTERN KENTUCKY REMAINS SANDWICHED BETWEEN AN AREA OF SURFACE HIGH PRESSURE SITUATED OFF OF THE CAROLINA COAST...AND OCCLUDING LOW PRESSURE ACROSS SOUTH CENTRAL CANADA...LINKED TO A NEARLY STATIONARY FRONT ALIGNED NORTH TO SOUTH ALONG THE PLAINS. ALOFT...PLENTIFUL MOISTURE HAS BEEN FEEDING IN FROM THE SOUTHWEST OUT AHEAD OF A SLOW- MOVING SHORT WAVE TROUGH THAT HAS BEEN PLAGUING THE GULF COAST FOR THE PAST FEW DAYS. MEANWHILE...A MORE STOUT UPPER LEVEL TROUGH IS MOVING EAST ALONG THE U.S./CANADIAN BORDER. DOWNSLOPING SOUTHEASTERLY WINDS HAVE BEEN SCOURING OUT ANY PRECIPITATION THAT HAS TRIED TO MAKE IT IN FROM THE SOUTH TODAY...WITH ONLY A FEW SPRINKLES NOTED THUS FAR. THIS TREND LOOKS TO CONTINUE THROUGH THIS EVENING. THE MODELS ARE IN GOOD AGREEMENT WITH SLOWLY LIFTING THE GULF WAVE THROUGH THE TENNESSEE AND OHIO VALLEYS OVER THE NEXT 24 TO 36 HOURS AS IT GETS GRADUALLY INGESTED INTO THE MAIN WESTERLIES BY THE MORE DOMINATE NORTHERN STREAM WAVE. THIS WILL BRING ROUNDS OF SHOWERS AND ISOLATED TO SCATTERED THUNDER TO THE AREA BEGINNING LATER TONIGHT AND THROUGH THE DAY ON TUESDAY AS DEEP MOISTURE WILL BE IN PLACE...WITH PERIODS OF WEAK TO MODEST FORCING. DESPITE VERY HIGH PWATS FOR THIS TIME OF YEAR...AS HAS BEEN PREVIOUSLY NOTED...INSTABILITY CONTINUES TO BE IN QUESTION WITH SO MUCH CLOUD COVER...SO AM NOT CONFIDENT THAT THESE VALUES WILL BE REALIZED. STILL...WITH THIS KIND OF PATTERN IN PLACE...IT CERTAINLY CONTINUES TO BEAR WATCHING FOR LOCALLY HEAVY RAINERS. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 259 PM EDT SUN JUN 10 2012 LONG RANGE MODELS SHOW A RATHER BAGGY LONGWAVE PATTERN OVER THE SOUTHERN APPALACHIANS THROUGH THE REST OF THE WORK WEEK. BY THE WEEKEND...SOME AMPLIFICATION OCCURS AT 500 MB WITH RIDGING TAKING SHAPE OVER THE UPPER MIDWEST AND GREAT LAKES WHILE STUBBORN TROUGHINESS HANGS IN ALONG THE EASTERN SEABOARD. THE COLD FRONT AND UPPER LEVEL LOW WHICH WILL BRING THE EARLY WEEK RAINS WILL BE OFF TO OUR EAST BY TUESDAY NIGHT AND BROAD...WEAK HIGH PRESSURE WILL BUILD INTO THE APPALACHIANS FOR THE DURATION OF THE PERIOD. SENSIBLE WEATHER WILL FEATURE A FEW LINGERING SHOWERS TUESDAY NIGHT BEHIND OUR DEPARTING FRONTAL SYSTEM. THE REST OF THE PERIOD WILL LIKELY BE PRECIP FREE FOR MOST FOLKS AS A DRY NORTHEASTERLY FLOW DOMINATES. A FEW WEAK DISTURBANCES RETROGRADING TO THE SOUTHWEST UNDER THE BUILDING RIDGE OVER THE GREAT LAKES MAY KICK OFF AN ISOLATED SHOWER FRIDAY THROUGH SUNDAY. HOWEVER...SURFACE DEWPOINTS WILL BE FAIRLY LOW AND PWATS ONLY REBOUND TO AROUND AN INCH SO MODELS MAY BE OVERDOING THE QPF...AT LEAST ON THIS SIDE OF THE APPALACHIAN SPINE. AS SUCH...HAVE TRIMMED BACK ANY MENTION OF PRECIP TO JUST THE HIGHER TERRAIN AREAS ALONG THE TN AND VA BORDERS. TEMPERATURES ARE EXPECTED TO REMAIN PRETTY MUCH NEAR NORMAL THROUGH THE PERIOD...AND WITH COMFORTABLE DEWPOINTS. OVERNIGHT LOWS WILL LIKELY SNEAK INTO THE 50S MOST NIGHTS IN THE VALLEYS AS WELL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 140 AM EDT MON JUN 11 2012 VFR CONDITIONS WILL CONTINUE THROUGH THE OVERNIGHT HOURS BUT CIGS ARE EXPECTED TO BEGIN LOWERING WITH -RA POSSIBLE AT SME AND LOZ. STILL SOME UNCERTAINTY THOUGH AS TO HOW MUCH PRECIP WILL DEVELOP THROUGH 12Z AND WHAT THE END RESULT WILL BE ON FLIGHT CATS..BUT AM EXPECTING MVFR CONDITIONS TO MATERIALIZE AROUND DAYBREAK AND CONTINUE THROUGH THE DAY AS -SHRA BECOME MORE PREVALENT ACROSS ERN KY. STILL CANNOT RULE OUT SOME THUNDER DURING THE DAY AS WELL...BUT WITH UNCERTAINTY HERE AS WELL WILL CONTINUE TO ADVERTISE THIS WITH VCTS AT THE TAF SITES. A COLD FRONT CURRENTLY MOVING THROUGH THE MIDWEST IS EXPECTED TO BEGIN ENCROACHING ON THE AREA LATER TODAY/TONIGHT AND WILL KEEP UNSETTLED CONDITIONS WITH A CHANCE FOR MORE TSTMS THROUGH THE END OF THE PERIOD. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KAS/MB SHORT TERM...GEOGERIAN LONG TERM....ABE AVIATION...MB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
532 AM EDT MON JUN 11 2012 .SHORT TERM...(TODAY) ISSUED AT 518 AM EDT MON JUN 11 2012 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A FAIRLY DEEP TROF MOVING ACROSS THE NRN PLAINS. AS EXPECTED DUE TO WEAKENING INSTABILITY... SHRA/TSRA THAT DEVELOPED YESTERDAY AFTN AHEAD OF COLD FRONT IN MN DIMINISHED AS THEY APPROACHED UPPER MI EARLIER IN THE NIGHT. HOWEVER...A LINGERING RIBBON OF MUCAPE WHICH HAS RECENTLY INCREASED TO 500-1000J/KG PER LATEST SPC MESOANALYSIS IS SUPPORTING SCT SHRA/TSRA WHICH ARE SPREADING/DEVELOPING NE INTO THE WRN FCST AREA AS OF 09Z. MAIN CONCERN IN THE SHORT TERM REVOLVES AROUND REDEVELOPMENT OF CONVECTION TODAY AS COLD FRONT DRIFTS ACROSS THE AREA. SHRA/TSRA SPREADING INTO WRN UPPER MI WILL PROBABLY PERSIST FOR THE NEXT FEW HRS GIVEN AVBL INSTABILITY. COLD FRONT SHOULD THEN CLEAR THE W BEFORE REDEVELOPMENT CAN OCCUR TODAY. TO THE E...DEBRIS CLOUDS FROM SHRA/TSRA WILL PROBABLY THIN OUT SUFFICIENTLY TO ALLOW FOR DECENT HEATING AHEAD OF THE COLD FRONT AS IT MOVES ACROSS CNTRL UPPER MI THIS AFTN. UTILIZING MODIFIED NAM FCST SOUNDINGS FOR T/TD OF MID 80S/LWR 60S PRIOR TO MODEL GENERATED PCPN (GFS SOUNDING CONTAMINATED BY PCPN) YIELDS SBCAPE IN THE 1000-1500J/KG RANGE. WITH DEEP LAYER SHEAR OF 30-40KT...THERE WILL BE THE POTENTIAL FOR ORGANIZED STORMS AND SVR WX. HIGH RES MODELS GIVE CONFLICTING SIGNALS ABOUT WHETHER CONVECTION WILL REDVELOP AS SEVERAL INDICATE LITTLE OR NO REGENERATION TODAY. HOWEVER...GIVEN POTENTIAL INSTABILITY...SEEMS PRUDENT TO MENTION AT LEAST SCT SHRA/TSRA THIS AFTN. A QUICK CHECK OF THE 06Z LOCAL HIGH RES WRF AND 4KM NAM ARE VERY SUPPORTIVE OF THIS IDEA AS THEY SHOW CONVECTION DEVELOPING ACROSS CNTRL UPPER MI EARLY THIS AFTN AND THEN SPREADING E. APPEARS THE AREA FROM ROUGHLY CRYSTAL FALLS TO ISHPEMING EASTWARD WILL HAVE THE POTENTIAL FOR SVR STORMS THIS AFTN. SVR POTENTIAL SHOULD BE LOWER TOWARD LAKE MICHIGAN ACROSS SE DELTA/SRN SCHOOLCRAFT COUNTIES WITH SRLY FLOW/MARINE INFLUENCE OFF THE LAKE. OTHER ITEM OF NOTE TODAY IS THE DRIER AIR MOVING INTO WRN UPPER MI BEHIND FRONT. SEVERAL PIECES OF GUIDANCE SUGGEST DWPTS FALLING INTO THE UPPER 40S WHICH RESULTS IN RH FALLING TO AROUND 30PCT THIS AFTN. WITH WINDS GUSTING TO 20-25MPH THIS AFTN...THERE WILL BE AN INCREASED RISK OF WILDFIRES WHERE SIGNIFICANT RAINFALL HAS NOT OCCURRED RECENTLY. .LONG TERM...(TONIGHT THROUGH SUNDAY) ISSUED AT 518 AM EDT MON JUN 11 2012 FOR THE START OF THE PERIOD 00Z TUE...A MID LEVEL SHORTWAVE TROUGH AXIS WILL BE FROM WRN HUDSON BAY TO CENTRAL MN...WITH A SFC LOW OVER CENTRAL NRN ONTARIO. A COLD FRONT/SFC TROUGH WILL STRETCH S TO CENTRAL UPPER MI BY 00Z TUE. SOME SHOWERS AND THUNDERSTORMS WILL BE ONGOING ALONG AND AHEAD OF THE COLD FRONT...BUT THE DRY SLOT WILL BE MOVING IN AROUND THIS TIME DURING LOSS OF DAYTIME HEATING. THERE IS A POSSIBILITY OF SOME ELEVATED CONVECTION LATE IN THE EVENING OR EARLY OVERNIGHT...BUT I THINK THE DRY AIR WILL KEEP THAT FROM HAPPENING. WILL DEPICT PRECIP WITH CHANCE POPS MOVING OUT OF THE CWA BY 06Z TUE. BY 12Z TUE...THE 500MB TROUGH AXIS WILL BE FROM ERN HUDSON BAY TO WRN LAKE SUPERIOR...WITH THE SFC LOW NEAR JAMES BAY AND SFC HIGH PRESSURE MOVING INTO WRN MN. THE COLD FRONT WILL BE E OF THE CWA...WITH GOOD CAA IN THE WNW LOW LEVEL FLOW OVER THE AREA. 850MB TEMPS WILL BE AROUND 3C E AND -1C W. BY 18Z TUE...THE 500MB TROUGH AXIS WILL BE OVER THE CENTER OF THE CWA...WITH THE SFC HIGH BEGINNING TO MOVE INTO THE WRN CWA. 850MB TEMPS AT 18Z WILL RANGE FROM -2C N TO 2C S. BY 00Z WED...THE 500MB TROUGH AXIS WILL BE OVER FAR ERN UPPER MI...WHILE THE SFC HIGH WILL BE OVER MOST OF THE CWA. MODEL SOUNDING SUGGEST MIXING TO AROUND 825MB TUE...RESULTING IN HIGHS IN THE 50S N TO 60S S...AND LOW DEW PTS. THE SFC HIGH WILL BE CENTERED OVER THE CWA TUE NIGHT...WHICH WILL LEAD TO FROST POTENTIAL AS COOL TEMPS TUE DROP QUICKLY UNDER MOSTLY CLEAR SKIES. WENT WITH THE LOW SIDE OF TEMP GUIDANCE...WITH MANY LOCATIONS OVER THE INTERIOR DROPPING NEAR OR BELOW FREEZING. WILL KEEP MENTION OF FROST IN HWO. WED THROUGH FRI...THE SFC HIGH MOVES E WHILE SFC LOW PRESSURE DEVELOPS WELL TO OUR W IN RESPONSE TO A SERIES OF SHORTWAVES. THE RESULTING SLY FLOW IN THE LOW LEVELS BRINGS OFF AND ON CONVECTION FROM LATE WED THROUGH FRI...BUT MODELS INDICATE MOST OF THAT STAYING W OF THE CWA AND INTO WRN LAKE SUPERIOR. WILL KEEP FORECAST FOR UPPER MI DRY THROUGH THIS PERIOD AS A DRIER PATTERN HAS VERIFIED BETTER RECENTLY...AND MOST MODELS KEEP US DRY ANYWAYS. AN UPPER RIDGE WILL BUILD INTO THE AREA FROM THE S...BRINGING STEADILY INCREASING TEMPS WED THROUGH AT LEAST FRI. BY FRI...850MB TEMPS SHOULD BE UP TO 16C...THEN UP TO 18C ON SAT AND SUN. MODELS DIVERGE ON SOLUTIONS FOR THE WEEKEND...WITH THE 12Z/10 ECMWF BRINGING A TROUGH PUSHING IN FROM THE NW...WHILE THE 00Z/11 GFS KEEPS THE UPPER RIDGE IN PLACE. USED A CONSENSUS OF MODELS FOR THE WEEKEND GIVEN LOW CONFIDENCE IN ANY PARTICULAR MODEL SOLUTION. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 136 AM EDT MON JUN 11 2012 EXPECT MAINLY VFR CONDITIONS THROUGH THE FCST PERIOD. HOWEVER...THERE MAY BE PERIOD OF MVFR CIGS AT KIWD EARLY THIS MORNING ASSOCIATED WITH LOW LEVEL MOISTURE BEHIND A COLD FRONT MOVING INTO WRN UPPER MI. IN ADDITION...EXPECT LLWS OVERNIGHT WITH A LOW LEVEL JET AHEAD OF THE COLD FRONT. SCT -SHRA ARE POSSIBLE AS THE FRONT MOVES THROUGH BUT CONFIDENCE IS ONLY MARGINAL THAT ANY TSRA WILL OCCUR SO WERE NOT INCLUDED AT THIS TIME. BY MID TO LATE MORNING...CLOUDS CLEAR OUT AS DRY AIR MOVES IN. WEST WINDS COULD BECOMING GUSTY AND PICK UP SUBSTANTIALLY AT KCMX AND KIWD BY EVENING AS A SECONDARY COLD FRONT MOVES THROUGH. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 518 AM EDT MON JUN 11 2012 AHEAD OF A COLD FRONT...S WINDS WILL BE IN THE 15-25KT RANGE OVER ERN LAKE SUPERIOR TODAY...ESPECIALLY EARLY IN THE DAY. SOME OF THE HIGHER OBSERVING PLATFORMS WILL SEE WINDS TO AROUND 30KT. BEHIND THE COLD FRONT...A PUSH OF STRONGER WESTERLY WINDS TO 25-30KT WILL ARRIVE OVER WRN LAKE SUPERIOR MID/LATE AFTN. THESE STRONGER WINDS WILL THEN SPREAD ACROSS THE LAKE TONIGHT. LOOK FOR THE WINDS TO GRADUALLY DIMINISH FROM W TO E TUE WITH WINDS FALLING BLO 15KT TUE NIGHT AS HIGH PRES ARRIVES OVER THE UPPER LAKES. WINDS WED THRU FRI SHOULD BE UNDER 20KT AS PRES GRADIENT REMAINS RELATIVELY WEAK BTWN THE DEPARTING HIGH AND A LOW PRES TROF SETTING UP WELL TO THE W AND NW. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...JLB MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
411 AM CDT Mon Jun 11 2012 .DISCUSSION... Short Term (Tonight-Wednesday) Overnight, the focus was on two lines of convection: the leading line being the advancing gust front and the second line being focused along the cold front. The showers and thunderstorms along the gust front continued to weaken through the overnight hours, with the bit of remnant activity tracking southeast of the Missouri River by 09Z. The better area of convective activity was focused along the cold front that was stretching roughly along a line from North Kansas City to Cameron and Bethany around 09Z. The activity was remaining well below severe limits with 1000-1500 J/kg MUCAPE, weak shear, and poor lapse rates present. This line of thunderstorms had been fairly slow-moving, but has become a bit more progressive toward the southeast with the help of 20-25kt 850mb winds. This slow tracking was resulting in higher rainfall rates across extreme northeast Kansas and northwest Missouri, with some locations likely accumulating more than one inch of rain within an hour. HRRR shows the line of thunderstorms stretching along a Kansas City to Chillicothe line by around 10Z, progressing just south of the Missouri River by around 13Z. Short range models are in fairly good agreement that this thunderstorm activity will shift southeast of the forecast area late this morning, but cannot rule out a few lingering showers and thunderstorms across central Missouri early this afternoon. Winds will shift to the northwest behind the advancing cold front. However, cold air advection behind the cold front will be limited today so should see afternoon temperatures still warmer than normal -- into the middle 80s. High pressure will build in across the Northern and Central Plains later this afternoon and track toward the Great Lakes region by the middle of the week, keeping conditions dry. Temperatures look to be near to slightly above seasonal normals through Wednesday as winds shift from northeast to southeast with the eastward-moving surface high. As the upper level trough over the Northern Plains progresses toward the northern Great Lakes, a more zonal flow will set up across the western and central CONUS through mid-week. Models have shown the potential for a few disturbances to develop within the zonal flow primarily west of the forecast area across Kansas. Confidence is low in whether or not any of these impulses will spread enough eastward to clip eastern Kansas and extreme western Missouri Wednesday and Wednesday night, so have nothing more than slight chance pops in for that area. ACH Medium Range (Thursday through Sunday)... Prefer a wait and see approach as it relates to rain chances during the medium range period. The 00z ECMWF and GFS build mid level heights, with the ECMWF developing a closed high, across the mid MO River Valley while a western U.S. trough builds. While it`s certainly possible a weak vorticity lobe or two will meander across the Central Plains Thursday or Friday within a chaotic and weak westerly flow coming out of the Rockies, confidence is low on just how much convection, if any can make it into the CWA. Agree with the previous discussion in favoring the drier ECMWF over the relatively wet GFS. As such can only justify slight chance pops until the end late Sunday when falling heights across the Plains in response to the approaching upper trough offers some hope that increasing dynamics will generate some scattered convection. A gradual warm up on temperatures and dewpoints continues to look in order with readings in the upper 80s/90 by the weekend. MJ && .AVIATION... Convection percolating along and behind front will continue for the next few hours over the terminals as the front lays out more east west. Shear is weak and gust front getting out ahead will keep storms below severe levels but as new elevated storms develop the terminals will be in and out of MVFR until around daybreak. Adolphson && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ WFO EAX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1159 PM CDT SUN JUN 10 2012 .UPDATE... ISSUED AT 1037 PM CDT SUN JUN 10 2012 ISSUED AT 651 PM CDT SUN JUN 10 2012 MADE SOME MINOR CHANGES TO THE POPS FORECAST FOR EAST CENTRAL MISSOURI CONCERNING THE TIMING OF THE CHANCE FOR POPS. SLIGHTLY DELAYED TO POPS ARRIVAL OVER EAST CENTRAL MISSOOURI. STRONG CAP CONTINUES OVER CENTRAL THROUGH SOUTHEAST AND EAST CENTRAL KANSAS AT THIS TIME. STILL BELIEVE THAT THE LOCAL LSX WRF AND HRRR IN SOME FORM HAS THE BEST SOLUTIONS COMPARED TO THE NSSL-NCEP WRF MODEL. HRRR APPEARS TO BE TO SHOW VERY STRONG REFELCTVITY ORGANIZATION WHICH MIGHT BE SUSPECT GIVEN THE EVENING ENVIRONMENT. LIKE THE LOCAL WRF THE BEST. STILL BELIEVE MUCH OF THE PRECIPITATION WILL REMAIN GENERALLY ALONG AND NORTH OF I-70. AS CONVECTION GENERALLY MOVES ACROSS THE NORTHERN HALF OF MISSOURI IT WILL HAVE SOME PROBLEMS MAINTAIN LINE STRUCTURE DUE TO WEAK VERTICAL SHEAR. ALSO WOULD LIKE TO SEE HIGHER CAPE VALUES FOR THIS TIME OF THE YEAR FOR A DYNAMIC SYSTEM TO EVOLVE. COMPARING CURRENT CASE TO PREVIOUS LINE CASES THIS EVENING. LINE-TO WEAK BROAD BOWING REFLECTIVITY STRUCTURE WILL FURTHER WEAKEN AS CONVECTIVE SYSTEM MOVES INTO EXTREME NORTHEAST MISSOURI AND EAST CENTRAL SECTIONS OF THE STATE BY 11 TO 13 UTC. PRZYBYLINSKI .SHORT TERM... ISSUED AT 325 PM CDT SUN JUN 10 2012 (TONIGHT) ISO-SCT SHRA/TSRA MAY CLIP THE SERN CWA LATE THIS AFTN BUT THE BULK OF ANY PCPN SHOULD REMAIN CLOSER TO THE MID-LEVEL LOW OVER AR/LA/MS AS IT LIFTS INTO THE TN VALLEY. ADDITIONAL SCT TSRA ARE EXPECTED TO DEVELOP LATE TONIGHT ALONG A TRAILING COLD FRONT AS IT SINKS SEWD FROM THE PLAINS TOWARDS THE CWA. PCPN MAY NOT BE VERY WIDESPREAD GIVEN THE LIMITED DYNAMICS AND LACK OF UPPER LEVEL SUPPORT. KANOFSKY && .SHORT TERM... ISSUED AT 325 PM CDT SUN JUN 10 2012 (TONIGHT) ISO-SCT SHRA/TSRA MAY CLIP THE SERN CWA LATE THIS AFTN BUT THE BULK OF ANY PCPN SHOULD REMAIN CLOSER TO THE MID-LEVEL LOW OVER AR/LA/MS AS IT LIFTS INTO THE TN VALLEY. ADDITIONAL SCT TSRA ARE EXPECTED TO DEVELOP LATE TONIGHT ALONG A TRAILING COLD FRONT AS IT SINKS SEWD FROM THE PLAINS TOWARDS THE CWA. PCPN MAY NOT BE VERY WIDESPREAD GIVEN THE LIMITED DYNAMICS AND LACK OF UPPER LEVEL SUPPORT. KANOFSKY && .LONG TERM... ISSUED AT 325 PM CDT SUN JUN 10 2012 (MONDAY THROUGH NEXT SUNDAY) UPPER LEVEL RIDGE WILL GET SUPPRESSED BY MONDAY AS A STRONG SHORTWAVE PASSES TO OUR N...AND WILL RESULT IN ZONAL FLOW UNTIL THURSDAY. AT THE SFC...A CDFNT WILL PUSH THRU MAINLY ON MONDAY AFTERNOON AND EVENING WITH HI PRES THEN DOMINATING THE REGION TUESDAY THRU WEDNESDAY NIGHT. MONDAY STILL LOOKS OUR BEST CHC FOR PCPN OVER THE NEXT WEEK... AND EVEN THEN...IT ISN/T AS MUCH OF A SLAM DUNK AS ONE WOULD THINK. WHILE THE MOISTURE AHEAD OF THE FRONT SHOULD BE DECENTLY RICH WITH SFC DWPTS PUSHING 70F...H850 DWPTS BETWEEN 13-16C...AND PWATS AROUND 1.75" WHICH IS NEAR THE 99TH PERCENTILE FOR CLIMO AND THIS SHOULD RESULT IN A VERY UNSTABLE ATMOSPHERE...LIFTING MECHANISMS DO NOT LOOK AS GOOD AND SCENARIOS TO BRING THIS ABOUT DEPICTED BY MODELS DO NOT INSPIRE CONFIDENCE. FIRST...SYNOPTIC SETUP OF CD FROPA WILL FEATURE /LAND-BETWEEN-THE-LOWS/ WHICH WILL FEATURE WEAK LO LEVEL CONVERGENCE WITH A RAPID PUNCH OF RIDGING IMMEDIATELY BEHIND. UPPER LEVEL SUPPORT LOOKS WEAK IF MODEL SIGNALS ARE CORRECT...AND IF INCORRECT WOULD MEAN JUST MODEL NOISE. IN ADDITION...A COUPLE EXPICIT 4KM WRF MODELS (BOTH NMM AND ARW) ARE SHOWING CDFNT AND DRY LINE LIGHTING UP TONIGHT...WITH THE SRN PART REMAINING THE MOST ACTIVE AND DIVING THRU SWRN MO...PUSHING AN EFFECTIVE BOUNDARY THRU MUCH OF THE FA BEFORE THINGS FIRE UP AGAIN IN THE FAR ERN FA MONDAY AFTERNOON. WHILE IT IS HARD TO BUY FULLY INTO THE EXPLICIT MODELS...THE MESSAGE IS THAT OF NOT HI CONFIDENCE IN RAIN CHCS AS WELL AS KEEPING IN MIND THE ONGOING MILD-MODERATE DROUGHT IN THE AREA. HAVE ONCE AGAIN CAPPED POPS AT 50PCT AREAWIDE AND JUST DIFFERENTIATED IN ROUGH TIMING OF BEST CHCS. CONVECTIVE DEBRIS CLOUDS AND PCPN CHCS SHOULD KEEP TEMPS IN CHECK ON MONDAY...BUT OVERALL PREFERRED THE HIGHER MET MOS NUMBERS. SHOULD SEE DRY WX TUESDAY THRU WEDNESDAY NIGHT ALTHOUGH ORDINARILY ZONAL FLOW IN JUNE WOULD GIVE ONE CAUSE FOR PAUSE. LO PWATS AND HI PRES IN CONTROL SHOULD ENSURE THAT...ALTHOUGH THE VACATING SFC HI ON WEDNESDAY NIGHT MAY LET SOMETHING SLIP THRU WITH BRIEF WINDOW OF OPPORTUNITY BETWEEN THAT AND RETURN OF UPPER RIDGE...WILL KEEP A CLOSE EYE ON THAT. THE UPPER LEVEL RIDGE WILL THEN RETURN IN FORCE THURSDAY THRU NEXT SUNDAY BRINGING WITH IT A RETURN OF THE HEAT OF COURSE. HAVE MAX TEMPS AROUND 90F GOING EACH DAY FROM FRIDAY ON...BUT WOULD NOT BE SURPRISED TO SEE FRIDAY AND SATURDAY 3-4F WARMER. THERE ARE VERY WEAK SIGNALS FOR RAIN CHCS FOR MUCH OF THIS PERIOD BUT OVERALL SYNOPTIC PATTERN SHOULD KEEP ANY CONVECTION OF A PULSE NATURE FROM WEAK SHEAR ENVIRONMENT AND LIMITED TO AFTERNOON HOURS...AND GENERALLY ISOLATED IN COVERAGE. PROBABILITIES ARE LO ENOUGH TO LIMIT TO 20PCT OR LESS...AND THUS SILENT ON THE FCST. MODELS ATTEMPT TO BREAK RIDGE DOWN A BIT ON SUNDAY...BUT BY DIFFERENT MEANS...BUT RESULT MAY BE THE SAME. HAVE EDGED BACK 30PCT CHC FROM SATURDAY TO SUNDAY BUT THIS IS EVEN SCALED BACK FROM WHAT MODELS ARE SHOWING AS SOMETHING DOESN/T QUITE LOOK RIGHT ABOUT IT. TES && .AVIATION... ISSUED AT 1141 PM CDT SUN JUN 10 2012 THUNDERSTORMS OVER NORTHWEST MISSOURI WILL CONTINUE MOVING EAST AND SHOULD BE MOVING INTO CENTRAL AND NORTHEAST MISSOURI BETWEEN 09Z-10Z. UNCERTAIN HOW EXTENSIVE THE COVERAGE WILL BE AS IT MOVES THROUGH CENTRAL INTO EASTERN MISSOURI AFTER SUNRISE. CURRENT INDICATIONS ARE THAT IT WILL STILL BE WIDELY SCATTERED TO SCATTERED COVERAGE SINCE THE STORMS WILL BE MOVING AWAY FROM THE GREATEST INSTABILITY. THINK WIDELY SCATTERED STORMS WILL CONTINUE INTO MONDAY AFTERNOON UNTIL THE FRONT MOVES THROUGH THE AREA. ELSEWHERE AND OTHERWISE...AREAS OF CIGS BETWEEN 2000-3000FT ARE DEVELOPING OVER SOUTHEAST MISSOURI AND MAY CONTINUE TO SPREAD NORTH-NORTHEAST ACROSS SOUTHWEST ILLINOIS AND EASTERN SECTIONS OF THE STL METRO AREA. MVFR CIGS SHOULD LIFT QUICKLY AFTER SUNRISE AND VFR FLIGHT CONDITIONS WILL PREVAIL OUTSIDE OF THUNDERSTORMS. SPECIFICS FOR KSTL... LATEST SATELLITE PICTURES ARE SHOWING A MVFR DECK BETWEEN 2000-3000FT DEVELOPING AROUND KFAM. LOOKS LIKE THE DECK MAY PASS EAST OF THE TERMINAL...BUT I CAN`T RULE OUT SOME INTERMITTENT MVFR CIGS BEFORE SUNRISE. ANY MVFR CIGS THAT DO FORM SHOULD BREAK UP AND LIFT QUICKLY AFTER SUNRISE. STILL EXPECTING THUNDERSTORMS IN THE VICINITY AFTER 12Z...NOT SURE WHAT THE COVERAGE WILL BE SO WILL CONTINUE VCTS WORDING INSTEAD OF TEMPO. WIDELY SCATTERED SHOWERS AND STORMS WILL LIKELY CONTINUE INTO THE AFTERNOON...WITH THE THREAT FINALLY ENDING WITH THE COLD FRONT PASSAGE. CARNEY && .LSX WATCHES/WARNINGS/ADVISORIES... MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1254 AM CDT MON JUN 11 2012 .UPDATE... /ISSUED 846 PM CDT SUN JUN 10 2012/ LATEST IR SAT AND RUC13 DATA SHOWS THE UPPER LEVEL LOW MOVING SLOWLY NE TOWARDS MIDDLE TN THIS EVENING FROM NEAR COLUMBUS MS. WITH THE LOSS OF HEATING SHOWERS AND THUNDERSTORMS ARE STARTING TO DECLINE IN COVERAGE ACROSS THE REGION. HAVE LOWERED POPS THROUGH 06Z WITH JUST ISOLATED TO SCTD SHWRS AND TSTORMS IN THE EASTERN PORTIONS OF THE FORECAST AREA OVERNIGHT INTO THE MORNING AT BEST. HIGH CONFIDENCE THAT ONLY A FEW SPOTS WILL EVEN SEE THIS ACTIVITY. TWEAKED TEMPS AND DEWPTS TO MATCH CURRENT READINGS WITH FORECAST LOWS LOOKING GOOD AT THIS POINT. --ABS && .PREV DISCUSSION... /ISSUED 251 PM CDT SUN JUN 10 2012/ INSTABILITY IS IN PLACE...HOWEVER WEAK LOW LEVEL CONVERGENCE HAS BEEN HINDERING CONVECTION...AND A FEW SHOWERS THAT HAVE DEVELOPED HAVE BEEN LIGHT...WITH THE EXCEPTION OF NORTHEAST MISSISSIPPI. NOT CONFIDENT WITH THE 12Z MODELS THAT A QUARTER TO A HALF INCH IN QPF AMOUNTS WILL OVERSPREAD THE MIDSOUTH THROUGH 11/00Z. THEY MAY RECEIVE THAT AMOUNT ACROSS PORTIONS OF NORTHEAST MISSISSIPPI BUT THAT`S ALL. THIS AREA WILL ALSO BE FAVORED FOR AN OCCASIONAL CLAP OF THUNDER...BUT STRONG STORMS SEEMS UNLIKELY. MOST MIDSOUTHERNERS HOWEVER WILL BE LUCKY TO SEE A FEW HUNDREDTHS OF AN INCH. BY SUNSET ANY LINGERING SHOWERS SHOULD BEGIN TO QUICKLY DISSIPATE...WITH DRY CONDITIONS EXPECTED FOR MOST OF THE AREA. ONLY THE FAR EASTERN COUNTIES MAY CONTINUE TO SEE SCATTERED SHOWER ACTIVITY. MOSTLY CLOUDY TO CLOUDY SKIES WILL BE THE RULE AREA WIDE...KEEPING LOW TEMPERATURES A DEGREE OR TWO WARMER THEN LAST NIGHT. MONDAY AND TUESDAY...THE LOW PRESSURE DISTURBANCE CURRENTLY OVER THE MIDSOUTH WILL SLOWLY TRACK EAST THROUGH THE VOLUNTEER STATE AS A MAJOR SHORTWAVE IN THE MAIN JET FLOW CROSSES THE NORTHERN PLAINS AND UPPER MIDWEST. THIS ENERGY WILL SEND A COLD FRONT SOUTHEAST THROUGH THE MID MISSISSIPPI VALLEY MONDAY AFTERNOON. PORTIONS OF THE MIDSOUTH WEST OF THE RIVER ARE ZONED FOR A SLIGHT RISK OF SEVERE WEATHER MONDAY EVENING AND OVERNIGHT AS THE TAIL END OF THE FRONT CROSSES THE OZARKS. LIFTED INDICES NEAR -10C ARE PROGGED FOR LATE TOMORROW AND NEARLY THAT ACROSS NORTH MISSISSIPPI BY MIDDAY TUESDAY AS THE FRONT PUSHES SOUTH. WILL LIKELY REMOVE ANY WORDING FOR A STRONG STORM FOR THIS AFTERNOON WITH THE DISTURBANCE...BUT KEEP MENTION OF SEVERE IN TOMORROW AND TUESDAY. FORECAST HIGHS A BIT TRICKY FOR MONDAY AS LOW LEVEL CLOUD COVER MAY BE ABUNDANT IN THE MORNING HOURS. HAVE LEANED TOWARD THE EURO AND NAM WITH SLIGHTLY COOLER HIGHS. SAME SITUATION ON TUESDAY AS CONVECTION WILL BE ONGOING OVER PORTIONS OF THE AREA. WEDNESDAY THROUGH THURSDAY...MODELS SHOW THE REGION ON THE SOUTH SIDE OF SURFACE HIGH PRESSURE WITH DRIER DEWPOINTS USHERING IN ON NORTHEAST BREEZES. TEMPERATURES WILL BE NEAR AVERAGE FOR MID JUNE...WITH ONLY A SLIGHT CHANCE OF AFTERNOON CONVECTION OVER THE EXTREME SOUTHERN COUNTIES...WHERE DEWPOINTS IN THE MID 60S WILL STILL BE FOUND. NEXT WEEKEND...SOUTHERLY WINDS WILL BRING HIGHER HUMIDITY BACK TO THE MIDSOUTH WITH ISOLATED SUMMERTIME AFTERNOON CONVECTION. HIGH TEMPERATURES WILL WARM SLIGHTLY. JAB && .AVIATION... 06Z TAF CYCLE OVERNIGHT...STILL THINK IFR CONDITIONS WILL DEVELOP AT KMKL AND KTUP WITH LOWERING CEILINGS AND FOG...MVFR CEILINGS DEVELOPING AT KMEM AND KJBR. CONDITIONS THEN GRADUALLY IMPROVING AFTER MID-MORNING MONDAY BECOMING MOSTLY VFR AFTER 18Z. UPPER LEVEL RIDGING IS EXPECTED TO TEMPORARILY SPREADING INTO THE AREA AS THE UPPER LEVEL TROUGH THAT HAS BEEN MOVING THROUGH THE LOWER MS RIVER VALLEY THE LAST COUPLE OF DAYS MOVES TO THE EAST. THIS MAY SUPPRESS CONVECTION EARLY IN THE AFTERNOON...HOWEVER WITH LESS CLOUDS AND STRONG DAYTIME HEATING EXPECTED DECIDED TO ADD VCTS TO THE TAFS AFTER 20Z-21Z. CONTINUED THE MENTION OF VCTS AT KMEM...KMKL..AND KJBR MONDAY EVENING THROUGH 12/06Z AS A COLD FRONT APPROACHES FROM THE NORTHWEST. AT KTUP KEPT VCTS IN UNTIL 12/02Z THEN REMOVED IT WITH THE LOSS OF DAYTIME HEATING. SE-S WINDS 3-7 KTS TONIGHT BECOMING SW 8-12 KTS MONDAY...THEN AFTER 12/00Z GENERALLY SW 5 KTS. JCL/KRM && && .PRELIMINARY POINT TEMPS/POPS... MEM 73 87 66 86 / 50 40 10 10 MKL 69 86 61 85 / 50 40 10 0 JBR 69 86 62 86 / 50 20 10 0 TUP 72 87 64 88 / 50 50 20 10 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
330 AM CDT MON JUN 11 2012 .SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT 330 AM CDT MON JUN 11 2012 MAIN FORECAST CONCERN IS ON TEMPERATURES THROUGHOUT THE SHORT TERM. CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED RIDGING OVER BRITISH COLUMBIA AND THE EASTERN GREAT LAKES... WITH TROUGHING IN-BETWEEN FROM SOUTH CENTRAL CANADA INTO THE NORTHERN PLAINS. WITHIN THIS TROUGH...A FAIRLY POTENT SHORTWAVE STRETCHED FROM NORTHERN MN SOUTHWEST INTO SOUTHEAST SOUTH DAKOTA... WHICH IS EVIDENT BY A DEEP DRY SLOT ON WATER VAPOR AND CLEAR SKIES ON IR IMAGERY. 00Z ABR SOUNDING IN THE DRY SLOT WAS VERY DRY WITH A PRECIPITABLE WATER OF 0.51 INCHES. AHEAD OF THE SHORTWAVE...AN AREA OF CONVECTION STRETCHED FROM NORTHERN WI SOUTH INTO FAR NORTHEAST IA/SOUTHWEST WI AND TO THE KANSAS CITY AREA. THE STRONGEST CONVECTION HAS SHIFTED TO THE SOUTHERN END OF THIS LINE...DUE TO BETTER LOW LEVEL CONVERGENCE SEEN IN 925 AND 850MB PROFILER DATA. CONVECTION THAT WAS OVER MN LAST EVENING HAS WEAKENED...DUE TO THE BETTER LOW LEVEL CONVERGENCE AND MOISTURE TRANSPORT SHIFTING SOUTH...DECREASING INSTABILITY AHEAD OF THE CONVECTION...AS WELL AS RAP LOW TO MID LEVEL FRONTOGENESIS FIELDS INDICATING WEAKENING THROUGH THE NIGHT. THE ONE CAVEAT TO THIS IS AN MCV RIDING NORTHEAST...ENTERING THE LA CROSSE AREA AS OF 08Z. ON ITS SOUTHEAST SIDE...THE COMBINATION OF DCAPE AROUND 1000 J/KG PER RAP ANALYSIS AND STORMS LINED ORTHOGONAL TO THE 0-3KM SHEAR VECTOR HAS HELPED PRODUCE SOME STRONG TO POSSIBLY DAMAGING WIND GUSTS. AT THE SURFACE...A COLD FRONT WAS PRESENT JUST BEHIND THE CONVECTION... STRETCHING FROM NEAR THUNDER BAY ONTARIO TO LA CROSSE WI. A SECONDARY COLD FRONT WAS PRESENT IN NORTHWEST MN. IN THE WAKE OF THIS FRONT...SATELLITE IMAGERY AND OBSERVATION SHOWED LOW CLOUDS... ISOLATED LIGHT SHOWERS AND MUCH COOLER TEMPERATURES IN THE 50S. TODAY AND TONIGHT...UPPER TROUGHING OVER SOUTH CENTRAL CANADA AND THE NORTHERN PLAINS IS FORECAST TO CONTINUE AN EAST-NORTHEASTWARD MOVEMENT...BEING PROPELLED BY THE CURRENT POTENT SHORTWAVE IN MN AND A SECOND ONE DROPPING DOWN THE BACK SIDE OF THE TROUGH. ALTHOUGH THE BULK OF THE TROUGH LIFTS INTO MANITOBA...NORTHWEST ONTARIO AND LAKE SUPERIOR...SOME OF THE TROUGHING WILL EXTEND DOWN INTO THE FORECAST AREA BY TONIGHT. IN SUMMARY...EXPECT THE TROUGH TO BRING A COOL DOWN FROM WHAT HAS BEEN SEEN LATELY. FIRST ISSUE TO CONTEND WITH IS THE ONGOING SHOWERS AND EMBEDDED THUNDERSTORMS. LATEST HRRR/RAP GUIDANCE AS WELL AS 11.00Z NAM SUGGESTS THE PRECIPITATION MAY BE COMPLETELY EAST OF THE AREA BY 12Z. LOOKS LIKE THERE SHOULD BE A BREAK AS INSTABILITY TRIES TO BUILD AHEAD OF THE MAIN COLD FRONT. HOWEVER...THE MAIN COLD FRONT WILL BE EAST OF THE AREA BEFORE IT CONVECTS...LIKELY BETWEEN 18-21Z. ATTENTION THEN TURNS TO THE SECONDARY COLD FRONT. THIS COMES THROUGH IN THE AFTERNOON...WITH WINDS INCREASING OUT OF THE WEST BEHIND IT. NO PRECIPITATION ANTICIPATED...BUT SOME STRATOCUMULUS AS SEEN BACK IN THE DAKOTAS SHOULD FILTER IN. THESE CLOUDS WILL LIKELY BECOME CELLULAR RESULTING FROM THE STRONG JUNE SUN...THUS DISSIPATING WITH LOSS OF HEATING IN THE EVENING. 850MB TEMPS OF 12-16C AT 18Z PLUS PLENTY OF SUN AND DRY AIR AHEAD OF THE SECONDARY COLD FRONT SHOULD ALLOW TEMPERATURES TO CLIMB INTO THE UPPER 70S TO MID 80S. TEMPERATURES MAY FALL SLIGHTLY ONCE THE SECONDARY FRONT MOVES IN. BETTER TEMPERATURE FALL EXPECTED TONIGHT AIDED BY NOCTURNAL COOLING AND CONTINUED COLD ADVECTION ON BREEZY NORTHWEST WINDS. BY 12Z TUESDAY...850MB TEMPS ARE PROGGED TO DROP AT LEAST DOWN TO 4-7C...AND PERHAPS SLIGHTLY COOLER AS INDICATED BY THE NAM. WENT WITH A BLEND OF GUIDANCE FOR LOWS...RESULTING IN UPPER 40S TO MID 50S. TUESDAY AND TUESDAY NIGHT...UPPER FLOW IS PROGGED TO GRADUALLY TURN ZONAL DURING THIS PERIOD AS THE UPPER TROUGHING LIFTS AWAY FROM THE AREA. WITHIN THE ZONAL FLOW...A SHORTWAVE IS INDICATED TO REACH CENTRAL SOUTH DAKOTA BY 12Z WEDNESDAY. SOME MID/HIGH CLOUDS ASSOCIATED WITH ISENTROPIC LIFT AHEAD OF THIS SHORTWAVE COULD GET INTO SOUTHEAST MN AND NORTHEAST IA LATE IN THE NIGHT. OTHERWISE... PLENTY OF DRY AIR NOTED BY PRECIPITABLE WATER VALUES OF 0.5 INCH OR LESS SHOULD KEEP SKIES CLEAR. ALTHOUGH THE DRY AIR AND CLEAR SKIES ARE FAVORABLE FOR WARMING...TEMPERATURES ON TUESDAY MAY STRUGGLE GIVEN 850MB TEMPS PROGGED TO STILL BE AT 4-7C AT 18Z. IN FACT...TAYLOR COUNTY MAY ONLY BE AROUND 2C. THESE ARE 2 STANDARD DEVIATIONS BELOW NORMAL. AS A RESULT...ONLY FORECAST HIGHS IN THE MID 60S TO LOW 70S...20 DEGREES COLDER THAN YESTERDAY. DEWPOINTS ARE LIKELY TO TANK FROM MIXING OF THE DRY AIR. SHOULD BE BREEZY TOO IN THE MORNING ADDING AN EXTRA CHILL BEFORE SURFACE HIGH PRESSURE BUILDS OVERHEAD IN THE EVENING TO CALM WINDS. THIS SETS THE STAGE FOR GOOD RADIATIONAL COOLING TUESDAY NIGHT...ESPECIALLY IN WISCONSIN. WOULD NOT BE SURPRISED TO HAVE SOME UPPER 30S FOR LOWS IN THE TYPICAL COLD SPOTS. WARMER READINGS ARE EXPECTED WEST OF THE MISSISSIPPI RIVER WHERE RETURN FLOW AND CLOUDS COME IN. WEDNESDAY AND WEDNESDAY NIGHT...UPPER LEVEL FLOW LOOKS TO AMPLIFY AGAIN AS TROUGHING DROPS DOWN INTO SOUTHWEST CANADA AND THE PACIFIC NORTHWEST BY 12Z THURSDAY. THIS AMPLIFICATION SHOULD HELP TAKE THE SHORTWAVE THAT WAS COMING INTO SOUTH DAKOTA TUESDAY NIGHT AND LIFT IT WELL NORTHWEST OF THE AREA. BY 00Z THURSDAY...ALL MODELS HAVE IT CROSSING CENTRAL OR NORTHERN MN. GIVEN DRY LOW LEVEL AIRMASS IN PLACE BY THE SURFACE HIGH PRESSURE AREA...AS WELL AS THE TRACK OF THE SHORTWAVE...NOT ANTICIPATING ANY PRECIPITATION TO SPREAD INTO THE FORECAST AREA. HOWEVER...CLOUD COVER IS AN ISSUE. INCREASING 305-310 K ISENTROPIC LIFT EAST OF THE SHORTWAVE SHOULD SPREAD MID AND HIGH CLOUDS ACROSS MUCH OF THE AREA ON WEDNESDAY. THESE CLOUDS MAY LIMITING HEATING SOMEWHAT...DESPITE WARMER 850MB TEMPS IN THE 8-12C RANGE. KEPT HIGHS IN THE LOW TO MID 70S...WHICH ARE ABOUT 5 DEGREES COOLER THAN WHAT THEY COULD BE IF FULL SUN WAS OBSERVED. THE CLOUDS DO LOOK TO CLEAR OUT WEDNESDAY NIGHT AS THE SHORTWAVE HEADS INTO ONTARIO. FOLLOWED A BLEND OF GUIDANCE FOR LOWS GIVEN NO STRONG SIGNAL TO GO COLDER OR WARMER. .LONG TERM...THURSDAY THROUGH SUNDAY NIGHT 330 AM CDT MON JUN 11 2012 11.00Z ECMWF/CANADIAN/GFS AND GFS ENSEMBLES REMAIN IN PRETTY GOOD AGREEMENT ON THE UPPER LEVEL PATTERN...AND IN FACT ARE IN BETTER AGREEMENT NOW COMPARED TO YESTERDAY. CONSENSUS IS THAT TROUGHING WILL HOLD OVER THE NORTHWESTERN U.S. THROUGH MUCH OF THE LONG TERM PERIOD...RESULTING IN STRENGTHENING RIDGING DOWNSTREAM OVER THE WESTERN GREAT LAKES. IN FACT...BY SUNDAY NIGHT WHEN MODELS HAVE THE TROUGH DIGGING MORE INTO THE NORTHERN ROCKIES...THE RIDGE DOWNSTREAM REALLY STRENGTHENS. IT APPEARS THAT MOST OF THE SHORTWAVES EJECTING OUT OF THE TROUGH WILL END UP STAYING MOSTLY TO THE NORTHWEST OF THE AREA. THUS...OVERALL MUCH OF THIS LONG TERM FORECAST LOOKS DRY. HAVE MAINTAINED SOME 20-30 PERCENT CHANCES OVER NORTHWEST PORTIONS OF THE AREA ON SATURDAY...NORTH OF I-90 SATURDAY NIGHT AND ACROSS THE ENTIRE AREA SUNDAY INTO SUNDAY NIGHT. THESE MOSTLY STEM FROM BEING ON THE NOSE OF SOME MOISTURE TRANSPORT AND SHORTWAVES COMING CLOSE TO THE AREA. HOWEVER...IT IS POSSIBLE THESE CHANCES MAY BE ABLE TO BE REMOVED IN LATER FORECASTS WITH MODELS TRENDING DRIER. ONE OTHER PERIOD TO WATCH IS THURSDAY WITH THE 11.00Z ECMWF BEING REALLY AGGRESSIVE IN DEVELOPING PRECIPITATION OVER MN. THIS APPEARS TO BE RELATED TO A SURGE OF WARM...MOIST AIR OCCURRING WITH THE BUILDING RIDGING. GIVEN THAT THE MODEL DOES NOT BRING THE PRECIPITATION INTO THE AREA AND OTHER MODELS SUGGESTING DRIER...HAVE KEPT THURSDAY DRY. WHAT COULD BE MORE SIGNIFICANT FOR THE LONG TERM FORECAST IS TEMPERATURES. WITH THE AREA NOW STRONGLY FORECAST TO BE UNDER RIDGING...AND IN BROAD BREEZY SOUTHERLY FLOW...WE COULD BE DEALING WITH ANOTHER LONG STRETCH OF 80S AND PERHAPS 90S. NEW ECMWF REALLY CAME IN WARM...WITH 850MB TEMPS FRIDAY THROUGH MONDAY HOVERING AROUND 20C OR SO...RESULTING IN HIGHS OF 90-95. HAVE BOOSTED TEMPERATURES UP ABOVE THE CONSENSUS AND THESE MAY STILL BE TOO COOL. && .AVIATION...THROUGH 06Z TUESDAY 1110 PM CDT SUN JUN 10 2012 SHOWERS AND THUNDERSTORMS WILL MOVE EAST ALONG AND JUST BEHIND A COLD FRONT THAT CURRENTLY EXTENDS FROM THE TWIN CITIES DOWN TO MASON CITY. IT LOOKS LIKE IT WILL BE ABOUT A 3-4 HOUR PERIOD OF CONVECTION WITH SOME INTERMITTENT THUNDERSTORMS POSSIBLE. CONDITIONS WILL MAINLY BE VFR THOUGH CEILINGS MAY DROP DOWN TO BETWEEN 2-3KFT FOR A PERIOD AS THE SHOWERS AND STORMS MOVE THROUGH OVERNIGHT. WINDS WILL GO LIGHT AFTER THE FRONT AND CONVECTION PASSES THROUGH...BUT CLOUD COVER WILL LIKELY PERSIST THROUGH DAYBREAK. THUS...AM NOT EXPECTING ANY FOG TO FORM AT RST OR LSE THIS MORNING. WINDS WILL INCREASE INTO THE 20-25KT RANGE THIS AFTERNOON AS A SECONDARY COLD FRONT MOVES THROUGH THE REGION. && .ARX WATCHES/WARNINGS/ADVISORIES... 330 AM CDT MON JUN 11 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS ALBANY NY
1108 AM EDT MON JUN 11 2012 .SYNOPSIS... HIGH PRESSURE ALOFT WILL BUILD INTO THE REGION THROUGH TODAY...WITH WARM AND SOMEWHAT HUMID CONDITIONS THROUGH TONIGHT. WIDESPREAD SHOWERS AND THUNDERSTORMS WILL RETURN FOR TUESDAY INTO EARLY WEDNESDAY ASSOCIATED WITH A PERIOD OF MODERATE TO HEAVY RAINFALL AS A FRONTAL BOUNDARY SLOWLY CROSSES THE REGION. && .NEAR TERM /THROUGH TONIGHT/... AS OF 935 AM EDT...STRATUS CLOUDS CONTINUE TO EXPAND N AND W...ACROSS NW CT...THE MID HUDSON VALLEY REGION AND BERKSHIRES...AS WELL AS ACROSS THE SE CATSKILLS. AREAS OF LOW CLOUDS/FOG ACROSS THE WESTERN ADIRONDACKS...AND PORTIONS OF THE HELDERBERGS APPEARS TO BE DECREASING. HAVE MADE SOME CHANGES TO GRIDDED DATABASE BASED ON RECENT OBS...12Z UA SOUNDINGS...AND LATEST RAP/HRRR. FIRST WAS TO EXPAND THE SLIGHT CHC POPS A BIT FURTHER SOUTH INTO THE CENTRAL AND WESTERN MOHAWK VALLEY. THE LATEST RAP AND HRRR CONTINUE TO INDICATE POCKETS OF FAIRLY DECENT INSTABILITY DEVELOPING THIS AFTERNOON IN THIS REGION. IN ADDITION...THIS REGION WILL BE CLOSER TO A WEAK BOUNDARY...SEPARATING A SLIGHTLY COOLER MODIFIED MARINE AIR MASS TO THE E AND S...FROM A WARMER...MORE CONTINENTAL AIR MASS TO THE N AND W. ELSEWHERE...HAVE INCREASED CLOUDS COVERAGE AND LOWERED MAX TEMPS ACROSS WESTERN NEW ENGLAND...AND THE MID HUDSON VALLEY REGION. AS THE AFOREMENTIONED MODIFIED MARINE AIR CONTINUES TO WORK N AND W...MAX TEMPS MAY FAIL TO REACH 80 ACROSS THE BERKSHIRES/SOUTHERN GREENS...LITCHFIELD CO AND THE MID HUDSON VALLEY. ELSEWHERE...STILL EXPECT MAXES TO REACH 80-85 ACROSS THE UPPER HUDSON VALLEY FROM ALBANY NORTH...AND MID 80S ACROSS THE CENTRAL AND WESTERN MOHAWK VALLEY...WHERE EVEN SOME UPPER 80S ARE POSSIBLE. WILL NEED TO WATCH HOW FAR N AND W THE LOWER CLOUDS REACH...AS THIS MAY REQUIRE ADDITIONAL MODIFICATIONS TO MAX TEMPS/TOWARD LOWER VALUES/WITHIN THE CAPITAL REGION SHOULD MORE CLOUDS FORM. FOR TONIGHT...ANY CONVECTION SHOULD QUICKLY DISSIPATE THIS EVENING AS THE UPPER LEVEL RIDGE AXIS SLIDES FURTHER OFFSHORE. THIS WILL ALLOW THE UPSTREAM NORTHERN PLAINS TROUGH TO MIGRATE FURTHER EAST TOWARD THE CENTRAL GREAT LAKES REGION. ALONG WITH ITS APPROACH...MOISTURE ADVECTION FROM THE SOUTHEAST CONUS AND OHIO VALLEY WILL ADVANCE NORTHWARD. FORECAST SOUNDINGS SUPPORT AN ENTRAINMENT OF LOW LEVEL STRATUS FROM THE ATLANTIC YET RATHER DRY BETWEEN 850-500MB TO KEEP THE CHANCE OF PRECIP WEST OF THE REGION. EXPECTATIONS ARE FOR AN INCREASING CLOUD COVER AND A MILD OVERNIGHT WITH LOWS MAINLY INTO THE 60S. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... RAINFALL POTENTIAL INCREASES FROM WEST TO EAST AS THE LOW LEVEL JET INCREASES TO >40KTS TO ASSIST WITH RAPID MOISTURE TRANSPORT INTO THE CWFA. NCEP MODEL SUITE ARE IN EXCELLENT AGREEMENT WITH A PERIOD OF MODERATE RAINFALL TO MOVE ACROSS THE REGION ON TUESDAY. INSTABILITY PARAMETERS ARE NOT FAVORABLE FOR SEVERE WEATHER...HOWEVER...MID LEVEL VALUES PER THE SHOWALTERS STILL SUPPORT EMBEDDED DEEPER CONVECTION. PWATS ARE PROGGED TO CLIMB IN EXCESS OF 1.75" WITH UPSTREAM VALUES CLOSE TO 2.00". THESE VALUES ARE 2-3 STANDARD DEVIATIONS ABOVE NORMAL TO SUPPORT EMBEDDED PERIODS OF HEAVY RAINFALL. FAVORED UPSLOPE REGIONS OF THE CATSKILLS...NW CT INTO THE BERKS AND SOUTHERN VT MAY ENHANCE RAINFALL RATES. SEE THE HYDRO DISCUSSION FOR FURTHER DETAILS ON THE RAINFALL POTENTIAL IMPACTS. OTHERWISE...RATHER HIGH POPS EXPECTED DURING THE DAY WITH TEMPERATURES A BIT COOLER DUE TO THE MARINE INFLUENCE...CLOUDS AND PRECIP WITH HIGHS MAINLY IN THE MID 60S TO LOWER 70S. MODELS HAVE COME AROUND TO THE ECMWF OF THE PAST SEVERAL DAYS WITH A MORE PROGRESSIVE FROPA TUESDAY EVENING. SO WE WILL GRADUALLY LOWER POPS FROM WEST TO EAST ALONG WITH IMPROVEMENTS TO THE SKY COVER. HOWEVER...EAST OF THE HUDSON RIVER...THOSE CLOUDS WILL LIKELY LINGER LONGER UNTIL THE FRONT HAS CLEARED THE EASTERN SEABOARD. CONFIDENCE CONTINUES TO INCREASE THAT WEDNESDAY SHOULD TURN OUT TO BE A DRIER DAY. WHILE THE MID LEVELS OF THE ATMOSPHERE ARE EXPECTED TO REMAIN RATHER DRY...LOWER LEVELS WILL LIKELY REMAIN A BIT MORE MOIST DUE TO THE RAINFALL FROM TUESDAY EVENT AND LOW LEVEL NORTHEAST WIND TRAJECTORIES. SCT-BKN CLOUDS ARE EXPECTED FOR OUT ADJACENT WESTERN NEW ENGLAND COUNTIES WITH DOWNSLOPING COMPONENT INTO THE HUDSON RIVER VALLEY FOR AT LEAST A PTSUNNY DAY. AS FOR TEMPERATURES...A MODEL BLEND APPROACH WAS UTILIZED WHICH DOWNPLAYS THE COOLER VALUES WITHIN THE GFS MOS AND THE MUCH WARMER VALUES SEEN IN THE MET MOS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... THE MODELS HAVE STARTED TO COME INTO BETTER AGREEMENT REGARDING THE EXTENDED PERIOD...FOR THE PERIOD BEGINNING ON WEDNESDAY EVENING. AT THIS POINT...IT APPEARS THAT THE UPPER TROUGH RESPONSIBLE FOR BRINGING THE MID WEEK WET WEATHER WILL BE PROGRESSIVE AND CONTINUE TO MOVE EASTWARD ACROSS CANADA. ALTHOUGH THE SURFACE FRONTAL BOUNDARY WON/T MAKE A CLEAN SWEEP OUT TO SEA...IT LOOKS TO GENERALLY WASH OUT ACROSS NEW ENGLAND TO THE EAST OF OUR REGION. ALSO...WHILE IT STILL APPEARS THAT A SURFACE WAVE MAY DEVELOP ALONG THIS FRONT...THE LATEST 00 UTC ECMWF/GFS BOTH SHOW A WEAK LOW REMAINING OFF THE COAST...WITH HIGH PRESSURE BUILDING INTO OUR AREA FROM SOUTHERN CANADA. WHILE WE STILL MAY HAVE A LOW CHC/SLIGHT CHC FOR A RAIN SHOWER ACROSS THE REGION /ESP FOR EASTERN AREAS/ FOR WED NIGHT INTO THURSDAY DUE TO THE PROXIMITY OF THE SFC BOUNDARY...IT DOESN/T APPEAR TO BE A WASHOUT BY ANY STRETCH. SKIES LOOK TO RANGE FROM PARTLY CLOUDY IN WESTERN AREAS...TO MOSTLY CLOUDY FOR WESTERN NEW ENGLAND...DUE TO THE WEAK NE SURFACE FLOW IN PLACE. MIN TEMPS LOOK TO RANGE FROM THE MID 40S TO UPPER 50S FOR WED NIGHT...WITH MAX TEMPS GENERALLY IN THE 70S ON THURSDAY. STRONG UPPER RIDGING LOOKS TO BUILD INTO THE REGION FOR FRIDAY INTO THE WEEKEND AS A RIDGE OVER THE GREAT LAKES BENDS NORTHEASTWARD INTO OUR AREA. ALTHOUGH THE MODELS SHOW A CLOSED OFF 500 HPA LOW ACROSS THE WESTERN ATLANTIC...IT LOOKS TO STAY FAR ENOUGH EAST OF OUR AREA TO BE OF ANY CONCERN FOR US. WITH THE BUILDING RIDGE...AND WARMING TEMPS ALOFT...ENOUGH OF A CAP LOOKS TO BE IN PLACE TO PREVENT ANY CONVECTION FROM FIRING UP...SO HAVE GONE WITH A DRY FORECAST FOR FRIDAY ONWARD. VALLEY MAX TEMPS SHOULD BE GRADUALLY WARMER AND WARMER EACH DAY...WITH UPPER 70S TO NEAR 80 FOR FRIDAY...LOW 80S FOR SATURDAY...AND LOW TO MID 80S FOR SUNDAY. SKIES GENERALLY LOOK MOSTLY CLEAR TO PARTLY CLOUDY. AT THIS POINT...DEWPOINTS DON/T LOOK TOO MUGGY JUST YET...WITH TDS GENERALLY IN THE 50S F. && .AVIATION /15Z MONDAY THROUGH FRIDAY/... A BATCH OF STRATUS CLOUDS OF 3-5 KFT OVER PORTIONS OF THE REGION...ALONG WITH A LIGHT S-SW WIND...PREVENTED ANY IFR FOG FROM DEVELOPING THIS MORNING. SOME MVFR BR IS POSSIBLE FOR A BRIEF TIME AT KPOU...OTHERWISE...VFR CONDITIONS SHOULD CONTINUE AT ALL TAF SITES THIS MORNING. SCT DIURNAL CU WILL DEVELOP WITHIN DAYTIME HEATING BY THE LATE MORNING. SOME PASSING HIGH CIRRUS IS POSSIBLE AS WELL. WITHIN DAYTIME MIXING...SOUTHERLY WINDS WILL AVERAGE AROUND 10 KTS. AN APPROACHING FRONTAL SYSTEM WILL SPREAD MID AND HIGH LEVEL CLOUDS ACROSS THE REGION TONIGHT. IN ADDITION...LIGHT S-SE SFC WINDS WILL CONTINUE AS WELL. THESE TWO FACTORS SHOULD PREVENT ANY RADIATIONAL FOG FROM DEVELOPING...KEEPING FLYING CONDITIONS MAINLY VFR. HOWEVER...THE MOIST SOUTHERLY FLOW MAY ALLOW FOR SOME MVFR STRATUS TO MOVE INTO KPOU FOR THE SECOND HALF OF THE NIGHT. OUTLOOK... TUE-TUE NT...VFR TO MVFR. SHRA/TSRA LIKELY. WED...VFR/MVFR. SHRA POSSIBLE EARLY. THU/FRI...VFR. SLIGHT CHC -SHRA. CHC LATE NIGHT/EARLY MORNING MVFR/IFR IN FOG/STRATUS. && .FIRE WEATHER... NO FIRE WEATHER CONCERNS ARE EXPECTED OVER THE NEXT SEVERAL DAYS. A SOUTH TO SOUTHEAST WIND WILL INCREASE TO AROUND 10 MPH TODAY WITH DRY WEATHER EXPECTED. AFTERNOON RH VALUES WILL DROP INTO THE 35-50 PERCENT...HIGHEST TO THE WEST OF ALBANY. MINIMUM RH VALUES TONIGHT REBOUND TO GREATER THAN 80 PERCENT. A WETTING RAIN IS EXPECTED ON TUESDAY TO FURTHER REDUCE FIRE WEATHER CONCERNS. && .HYDROLOGY... A MODERATE RAINFALL EVENT IS EXPECTED ON TUESDAY ACROSS THE HYDRO SERVICE AREA. LATEST MODEL GUIDANCE SUPPORTS A ROBUST MOISTURE TRANSPORT THAT SHOULD GENERATE AT LEAST BROKEN COVERAGE OF MODERATE TO HEAVY EMBEDDED CONVECTIVE RAINFALL RATES. EXPECTING THE RAINFALL TO BE OROGRAPHICALLY ENHANCED ACROSS PORTIONS OF THE CATSKILLS....BERKSHIRES AND SOUTHERN GREENS. PWAT ANOMALIES OF 2 TO 3 STD DEV ABOVE NORMAL...A >40 KT SOUTHERLY LOW LEVEL JET HELPING TO ENHANCE ISENTROPIC LIFT AND OROGRAPHICS SHOULD HELP ENHANCE RAINFALL RATES...AND THUS EXPECTING SOME LOCALLY HEAVIER TOTALS FOR THE EVENT AT OR ABOVE 2 INCHES. THIS SHOULD PRODUCE RISES ON AREA RIVERS AND STREAMS...BUT NO FLOODING IS EXPECTED ON THE STREAMS AND RIVERS. LATEST RUN OF THE MMEFS GUIDANCE ALSO SUPPORT THIS IDEA WITH NO POINTS EXPECTED TO CLIMB ABOVE FLOOD STAGE. 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...KL/BGM NEAR TERM...KL/BGM SHORT TERM...BGM LONG TERM...FRUGIS AVIATION...KL/FRUGIS FIRE WEATHER...BGM HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
937 AM EDT MON JUN 11 2012 .SYNOPSIS... HIGH PRESSURE ALOFT WILL BUILD INTO THE REGION THROUGH TODAY...WITH WARM AND SOMEWHAT HUMID CONDITIONS THROUGH TONIGHT. WIDESPREAD SHOWERS AND THUNDERSTORMS WILL RETURN FOR TUESDAY INTO EARLY WEDNESDAY ASSOCIATED WITH A PERIOD OF MODERATE TO HEAVY RAINFALL AS A FRONTAL BOUNDARY SLOWLY CROSSES THE REGION. && .NEAR TERM /THROUGH TONIGHT/... AS OF 935 AM EDT...STRATUS CLOUDS CONTINUE TO EXPAND N AND W...ACROSS NW CT...THE MID HUDSON VALLEY REGION AND BERKSHIRES...AS WELL AS ACROSS THE SE CATSKILLS. AREAS OF LOW CLOUDS/FOG ACROSS THE WESTERN ADIRONDACKS...AND PORTIONS OF THE HELDERBERGS APPEARS TO BE DECREASING. HAVE MADE SOME CHANGES TO GRIDDED DATABASE BASED ON RECENT OBS...12Z UA SOUNDINGS...AND LATEST RAP/HRRR. FIRST WAS TO EXPAND THE SLIGHT CHC POPS A BIT FURTHER SOUTH INTO THE CENTRAL AND WESTERN MOHAWK VALLEY. THE LATEST RAP AND HRRR CONTINUE TO INDICATE POCKETS OF FAIRLY DECENT INSTABILITY DEVELOPING THIS AFTERNOON IN THIS REGION. IN ADDITION...THIS REGION WILL BE CLOSER TO A WEAK BOUNDARY...SEPARATING A SLIGHTLY COOLER MODIFIED MARINE AIR MASS TO THE E AND S...FROM A WARMER...MORE CONTINENTAL AIR MASS TO THE N AND W. ELSEWHERE...HAVE INCREASED CLOUDS COVERAGE AND LOWERED MAX TEMPS ACROSS WESTERN NEW ENGLAND...AND THE MID HUDSON VALLEY REGION. AS THE AFOREMENTIONED MODIFIED MARINE AIR CONTINUES TO WORK N AND W...MAX TEMPS MAY FAIL TO REACH 80 ACROSS THE BERKSHIRES/SOUTHERN GREENS...LITCHFIELD CO AND THE MID HUDSON VALLEY. ELSEWHERE...STILL EXPECT MAXES TO REACH 80-85 ACROSS THE UPPER HUDSON VALLEY FROM ALBANY NORTH...AND MID 80S ACROSS THE CENTRAL AND WESTERN MOHAWK VALLEY...WHERE EVEN SOME UPPER 80S ARE POSSIBLE. WILL WIL NEED TO WATCH HOW FAR N AND W THE LOWER CLOUDS REACH...AS THIS MAY REQUIRE ADDITIONAL MODIFICATIONS TO MAX TEMPS/TOWARD LOWER VALUES/WITHIN THE CAPITAL REGION SHOULD MORE CLOUDS FORM. FOR TONIGHT...ANY CONVECTION SHOULD QUICKLY DISSIPATE THIS EVENING AS THE UPPER LEVEL RIDGE AXIS SLIDES FURTHER OFFSHORE. THIS WILL ALLOW THE UPSTREAM NORTHERN PLAINS TROUGH TO MIGRATE FURTHER EAST TOWARD THE CENTRAL GREAT LAKES REGION. ALONG WITH ITS APPROACH...MOISTURE ADVECTION FROM THE SOUTHEAST CONUS AND OHIO VALLEY WILL ADVANCE NORTHWARD. FORECAST SOUNDINGS SUPPORT AN ENTRAINMENT OF LOW LEVEL STRATUS FROM THE ATLANTIC YET RATHER DRY BETWEEN 850-500MB TO KEEP THE CHANCE OF PRECIP WEST OF THE REGION. EXPECTATIONS ARE FOR AN INCREASING CLOUD COVER AND A MILD OVERNIGHT WITH LOWS MAINLY INTO THE 60S. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... RAINFALL POTENTIAL INCREASES FROM WEST TO EAST AS THE LOW LEVEL JET INCREASES TO >40KTS TO ASSIST WITH RAPID MOISTURE TRANSPORT INTO THE CWFA. NCEP MODEL SUITE ARE IN EXCELLENT AGREEMENT WITH A PERIOD OF MODERATE RAINFALL TO MOVE ACROSS THE REGION ON TUESDAY. INSTABILITY PARAMETERS ARE NOT FAVORABLE FOR SEVERE WEATHER...HOWEVER...MID LEVEL VALUES PER THE SHOWALTERS STILL SUPPORT EMBEDDED DEEPER CONVECTION. PWATS ARE PROGGED TO CLIMB IN EXCESS OF 1.75" WITH UPSTREAM VALUES CLOSE TO 2.00". THESE VALUES ARE 2-3 STANDARD DEVIATIONS ABOVE NORMAL TO SUPPORT EMBEDDED PERIODS OF HEAVY RAINFALL. FAVORED UPSLOPE REGIONS OF THE CATSKILLS...NW CT INTO THE BERKS AND SOUTHERN VT MAY ENHANCE RAINFALL RATES. SEE THE HYDRO DISCUSSION FOR FURTHER DETAILS ON THE RAINFALL POTENTIAL IMPACTS. OTHERWISE...RATHER HIGH POPS EXPECTED DURING THE DAY WITH TEMPERATURES A BIT COOLER DUE TO THE MARINE INFLUENCE...CLOUDS AND PRECIP WITH HIGHS MAINLY IN THE MID 60S TO LOWER 70S. MODELS HAVE COME AROUND TO THE ECMWF OF THE PAST SEVERAL DAYS WITH A MORE PROGRESSIVE FROPA TUESDAY EVENING. SO WE WILL GRADUALLY LOWER POPS FROM WEST TO EAST ALONG WITH IMPROVEMENTS TO THE SKY COVER. HOWEVER...EAST OF THE HUDSON RIVER...THOSE CLOUDS WILL LIKELY LINGER LONGER UNTIL THE FRONT HAS CLEARED THE EASTERN SEABOARD. CONFIDENCE CONTINUES TO INCREASE THAT WEDNESDAY SHOULD TURN OUT TO BE A DRIER DAY. WHILE THE MID LEVELS OF THE ATMOSPHERE ARE EXPECTED TO REMAIN RATHER DRY...LOWER LEVELS WILL LIKELY REMAIN A BIT MORE MOIST DUE TO THE RAINFALL FROM TUESDAY EVENT AND LOW LEVEL NORTHEAST WIND TRAJECTORIES. SCT-BKN CLOUDS ARE EXPECTED FOR OUT ADJACENT WESTERN NEW ENGLAND COUNTIES WITH DOWNSLOPING COMPONENT INTO THE HUDSON RIVER VALLEY FOR AT LEAST A PTSUNNY DAY. AS FOR TEMPERATURES...A MODEL BLEND APPROACH WAS UTILIZED WHICH DOWNPLAYS THE COOLER VALUES WITHIN THE GFS MOS AND THE MUCH WARMER VALUES SEEN IN THE MET MOS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... THE MODELS HAVE STARTED TO COME INTO BETTER AGREEMENT REGARDING THE EXTENDED PERIOD...FOR THE PERIOD BEGINNING ON WEDNESDAY EVENING. AT THIS POINT...IT APPEARS THAT THE UPPER TROUGH RESPONSIBLE FOR BRINGING THE MID WEEK WET WEATHER WILL BE PROGRESSIVE AND CONTINUE TO MOVE EASTWARD ACROSS CANADA. ALTHOUGH THE SURFACE FRONTAL BOUNDARY WON/T MAKE A CLEAN SWEEP OUT TO SEA...IT LOOKS TO GENERALLY WASH OUT ACROSS NEW ENGLAND TO THE EAST OF OUR REGION. ALSO...WHILE IT STILL APPEARS THAT A SURFACE WAVE MAY DEVELOP ALONG THIS FRONT...THE LATEST 00 UTC ECMWF/GFS BOTH SHOW A WEAK LOW REMAINING OFF THE COAST...WITH HIGH PRESSURE BUILDING INTO OUR AREA FROM SOUTHERN CANADA. WHILE WE STILL MAY HAVE A LOW CHC/SLIGHT CHC FOR A RAIN SHOWER ACROSS THE REGION /ESP FOR EASTERN AREAS/ FOR WED NIGHT INTO THURSDAY DUE TO THE PROXIMITY OF THE SFC BOUNDARY...IT DOESN/T APPEAR TO BE A WASHOUT BY ANY STRETCH. SKIES LOOK TO RANGE FROM PARTLY CLOUDY IN WESTERN AREAS...TO MOSTLY CLOUDY FOR WESTERN NEW ENGLAND...DUE TO THE WEAK NE SURFACE FLOW IN PLACE. MIN TEMPS LOOK TO RANGE FROM THE MID 40S TO UPPER 50S FOR WED NIGHT...WITH MAX TEMPS GENERALLY IN THE 70S ON THURSDAY. STRONG UPPER RIDGING LOOKS TO BUILD INTO THE REGION FOR FRIDAY INTO THE WEEKEND AS A RIDGE OVER THE GREAT LAKES BENDS NORTHEASTWARD INTO OUR AREA. ALTHOUGH THE MODELS SHOW A CLOSED OFF 500 HPA LOW ACROSS THE WESTERN ATLANTIC...IT LOOKS TO STAY FAR ENOUGH EAST OF OUR AREA TO BE OF ANY CONCERN FOR US. WITH THE BUILDING RIDGE...AND WARMING TEMPS ALOFT...ENOUGH OF A CAP LOOKS TO BE IN PLACE TO PREVENT ANY CONVECTION FROM FIRING UP...SO HAVE GONE WITH A DRY FORECAST FOR FRIDAY ONWARD. VALLEY MAX TEMPS SHOULD BE GRADUALLY WARMER AND WARMER EACH DAY...WITH UPPER 70S TO NEAR 80 FOR FRIDAY...LOW 80S FOR SATURDAY...AND LOW TO MID 80S FOR SUNDAY. SKIES GENERALLY LOOK MOSTLY CLEAR TO PARTLY CLOUDY. AT THIS POINT...DEWPOINTS DON/T LOOK TOO MUGGY JUST YET...WITH TDS GENERALLY IN THE 50S F. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... A BATCH OF STRATUS CLOUDS OF 3-5 KFT OVER PORTIONS OF THE REGION...ALONG WITH A LIGHT S-SW WIND...PREVENTED ANY IFR FOG FROM DEVELOPING THIS MORNING. SOME MVFR BR IS POSSIBLE FOR A BRIEF TIME AT KPOU...OTHERWISE...VFR CONDITIONS SHOULD CONTINUE AT ALL TAF SITES THIS MORNING. SCT DIURNAL CU WILL DEVELOP WITHIN DAYTIME HEATING BY THE LATE MORNING. SOME PASSING HIGH CIRRUS IS POSSIBLE AS WELL. WITHIN DAYTIME MIXING...SOUTHERLY WINDS WILL AVERAGE AROUND 10 KTS. AN APPROACHING FRONTAL SYSTEM WILL SPREAD MID AND HIGH LEVEL CLOUDS ACROSS THE REGION TONIGHT. IN ADDITION...LIGHT S-SE SFC WINDS WILL CONTINUE AS WELL. THESE TWO FACTORS SHOULD PREVENT ANY RADIATIONAL FOG FROM DEVELOPING...KEEPING FLYING CONDITIONS MAINLY VFR. HOWEVER...THE MOIST SOUTHERLY FLOW MAY ALLOW FOR SOME MVFR STRATUS TO MOVE INTO KPOU FOR THE SECOND HALF OF THE NIGHT. OUTLOOK... TUE-TUE NT...VFR TO MVFR. SHRA/TSRA LIKELY. WED...VFR/MVFR. SHRA POSSIBLE EARLY. THU/FRI...VFR. SLIGHT CHC -SHRA. CHC LATE NIGHT/EARLY MORNING MVFR/IFR IN FOG/STRATUS. && .FIRE WEATHER... NO FIRE WEATHER CONCERNS ARE EXPECTED OVER THE NEXT SEVERAL DAYS. A SOUTH TO SOUTHEAST WIND WILL INCREASE TO AROUND 10 MPH TODAY WITH DRY WEATHER EXPECTED. AFTERNOON RH VALUES WILL DROP INTO THE 35-50 PERCENT...HIGHEST TO THE WEST OF ALBANY. MINIMUM RH VALUES TONIGHT REBOUND TO GREATER THAN 80 PERCENT. A WETTING RAIN IS EXPECTED ON TUESDAY TO FURTHER REDUCE FIRE WEATHER CONCERNS. && .HYDROLOGY... A MODERATE RAINFALL EVENT IS EXPECTED ON TUESDAY ACROSS THE HYDRO SERVICE AREA. LATEST MODEL GUIDANCE SUPPORTS A ROBUST MOISTURE TRANSPORT THAT SHOULD GENERATE AT LEAST BROKEN COVERAGE OF MODERATE TO HEAVY EMBEDDED CONVECTIVE RAINFALL RATES. EXPECTING THE RAINFALL TO BE OROGRAPHICALLY ENHANCED ACROSS PORTIONS OF THE CATSKILLS....BERKSHIRES AND SOUTHERN GREENS. PWAT ANOMALIES OF 2 TO 3 STD DEV ABOVE NORMAL...A >40 KT SOUTHERLY LOW LEVEL JET HELPING TO ENHANCE ISENTROPIC LIFT AND OROGRAPHICS SHOULD HELP ENHANCE RAINFALL RATES...AND THUS EXPECTING SOME LOCALLY HEAVIER TOTALS FOR THE EVENT AT OR ABOVE 2 INCHES. THIS SHOULD PRODUCE RISES ON AREA RIVERS AND STREAMS...BUT NO FLOODING IS EXPECTED ON THE STREAMS AND RIVERS. LATEST RUN OF THE MMEFS GUIDANCE ALSO SUPPORT THIS IDEA WITH NO POINTS EXPECTED TO CLIMB ABOVE FLOOD STAGE. 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...KL/BGM NEAR TERM...KL/BGM SHORT TERM...BGM LONG TERM...FRUGIS AVIATION...KL/FRUGIS FIRE WEATHER...BGM HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS TOPEKA KS
642 AM CDT MON JUN 11 2012 ...UPDATE TO AVIATION... .DISCUSSION... STRONG MOISTURE CONVERGENCE CONTINUES IN FAR NORTHEAST KANSAS BEHIND SURFACE FRONT...WHICH LIES FROM ROUGHLY FROM KDSM TO KTOP TO KWLD AT 08Z. GUSTY NORTHEAST WINDS WERE REPORTED AT KMHK AT 08Z WITH OUTFLOW BOUNDARY SHOWING NEAR THE KTWX RADAR. MUCH DRIER AIR NOT FAR BEHIND WITH SURFACE DEWPOINTS IN THE UPPER 40S IN NORTH CENTRAL KANSAS AND LOWER 30S IN NORTHWEST KANSAS. WEAK MID LEVEL RETURNS SHOWING UP ON WESTERN KANSAS RADARS BUT LITTLE NEARING THE SURFACE IN MID LEVEL FRONTOGENESIS. 0Z 850MB TEMPS WERE VERY CLOSE TO 20C THROUGHOUT THE SURROUNDING STATES...THOUGH TEMPS BELOW 10C WERE SAMPLED IN MONTANA. WILL GO ALONG WITH HRRR AND RUC WITH CONVECTION SLOWLY PUSHING SOUTHEAST OUT OF THE AREA THIS MORNING AS THE MODIFIED CONTINENTAL AIRMASS MOVES IN. WESTERN MID LEVEL RETURNS SHOULD ENCOUNTER THIS DRIER AIR AND STILL STRUGGLE TO REACH THE GROUND. COLD AIR ADVECTION TAKES ITS TIME GETTING HERE HOWEVER...WITH SOMEWHAT INCREASED LEVELS COMING LATE IN THE DAY. WITH SOME EARLY DAY HIGH CLOUD AS WELL...THIS MAY KEEP NORTHERN AREAS IN THE MID 80S...WITH SOME UPPER 80S ALONG I-70 WHERE EARLY DAY DEBRIS IS MORE REMOVED AND BETTER CALL WILL HOLD OFF LONGER. TONIGHT INTO TUESDAY PERIODS LOOK RATHER QUIET WITH SURFACE HIGH PASSING ACROSS NEBRASKA AND IOWA AND 700-850MB RIDGING OVER EASTERN KANSAS. MAY SEE SOME HIGH CLOUD MOVE OUT OF THE ROCKIES TUESDAY WITH HIGHS A LITTLE COOLER THAN TODAY. MODELS HAVE BEEN FAIRLY CONSISTENT WITH A WEAK UPPER WAVE MOVING THROUGH LATE TUESDAY NIGHT INTO WEDNESDAY EVENING. SOUTHERLY LOW/MID LEVEL FLOW WILL SLOWLY INCREASE RESULTING IN WEAK ISENTROPIC LIFT WHILE PRECIPITABLE WATER VALUES RISE TO AROUND 1.3 INCHES BY LATE WEDNESDAY. COMBINED FORCING AND DEEPER MOISTURE MAY BE ENOUGH FOR SOME CONVECTION...THOUGH COVERAGE IS MUCH IN QUESTION AT THIS POINT. WILL KEEP POPS ON THE LOW SIDE WEDNESDAY AND WEDNESDAY NIGHT...KEEPING TUESDAY NIGHT DRY AT THIS POINT. WEAK MID LEVEL LAPSE RATES SHOULD KEEP STRONG INSTABILITY IN CHECK. WARM AND HUMID CONDITIONS TO RULE MUCH OF THE EXTENDED PERIODS WITH LITTLE CHANGE IN AIRMASS FROM THE AFOREMENTIONED SITUATION. FAIRLY GOOD MODEL AGREEMENT WITH WEAK UPPER RIDGE FROM THE SOUTHERN PLAINS INTO THE GREAT LAKES THROUGH AT LEAST SATURDAY AND STRONG FORCING MECHANISM APPEAR LACKING...BUT ALSO LACKING IS STRONG CAPPING. SMALL PRECIPITATION CHANCES...NEAR CLIMATOLOGICAL VALUES FOR MID JUNE... WILL BE KEPT FOR THE BULK OF THESE PERIODS WITH TEMPS SOMEWHAT ABOVE NORMAL. 65 && .AVIATION... CONVECTION HAS MOVED OFF TO THE SOUTHEAST OF THE TOP AND FOE TERMINALS. A MID CLOUD DECK QWITH SOME LOWER STRATUS WILL CLEAR OUT BY 15Z THIS MORNING. VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. NORTH TO NORTHWEST WIND NEAR 10 KTS EXPECTED THROUGH 12/01Z THEN BECOME NORTH NORTHEAST LESS THAN 5 KTS. 53 && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
739 AM EDT MON JUN 11 2012 .SHORT TERM...(TODAY) ISSUED AT 518 AM EDT MON JUN 11 2012 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A FAIRLY DEEP TROF MOVING ACROSS THE NRN PLAINS. AS EXPECTED DUE TO WEAKENING INSTABILITY... SHRA/TSRA THAT DEVELOPED YESTERDAY AFTN AHEAD OF COLD FRONT IN MN DIMINISHED AS THEY APPROACHED UPPER MI EARLIER IN THE NIGHT. HOWEVER...A LINGERING RIBBON OF MUCAPE WHICH HAS RECENTLY INCREASED TO 500-1000J/KG PER LATEST SPC MESOANALYSIS IS SUPPORTING SCT SHRA/TSRA WHICH ARE SPREADING/DEVELOPING NE INTO THE WRN FCST AREA AS OF 09Z. MAIN CONCERN IN THE SHORT TERM REVOLVES AROUND REDEVELOPMENT OF CONVECTION TODAY AS COLD FRONT DRIFTS ACROSS THE AREA. SHRA/TSRA SPREADING INTO WRN UPPER MI WILL PROBABLY PERSIST FOR THE NEXT FEW HRS GIVEN AVBL INSTABILITY. COLD FRONT SHOULD THEN CLEAR THE W BEFORE REDEVELOPMENT CAN OCCUR TODAY. TO THE E...DEBRIS CLOUDS FROM SHRA/TSRA WILL PROBABLY THIN OUT SUFFICIENTLY TO ALLOW FOR DECENT HEATING AHEAD OF THE COLD FRONT AS IT MOVES ACROSS CNTRL UPPER MI THIS AFTN. UTILIZING MODIFIED NAM FCST SOUNDINGS FOR T/TD OF MID 80S/LWR 60S PRIOR TO MODEL GENERATED PCPN (GFS SOUNDING CONTAMINATED BY PCPN) YIELDS SBCAPE IN THE 1000-1500J/KG RANGE. WITH DEEP LAYER SHEAR OF 30-40KT...THERE WILL BE THE POTENTIAL FOR ORGANIZED STORMS AND SVR WX. HIGH RES MODELS GIVE CONFLICTING SIGNALS ABOUT WHETHER CONVECTION WILL REDVELOP AS SEVERAL INDICATE LITTLE OR NO REGENERATION TODAY. HOWEVER...GIVEN POTENTIAL INSTABILITY...SEEMS PRUDENT TO MENTION AT LEAST SCT SHRA/TSRA THIS AFTN. A QUICK CHECK OF THE 06Z LOCAL HIGH RES WRF AND 4KM NAM ARE VERY SUPPORTIVE OF THIS IDEA AS THEY SHOW CONVECTION DEVELOPING ACROSS CNTRL UPPER MI EARLY THIS AFTN AND THEN SPREADING E. APPEARS THE AREA FROM ROUGHLY CRYSTAL FALLS TO ISHPEMING EASTWARD WILL HAVE THE POTENTIAL FOR SVR STORMS THIS AFTN. SVR POTENTIAL SHOULD BE LOWER TOWARD LAKE MICHIGAN ACROSS SE DELTA/SRN SCHOOLCRAFT COUNTIES WITH SRLY FLOW/MARINE INFLUENCE OFF THE LAKE. OTHER ITEM OF NOTE TODAY IS THE DRIER AIR MOVING INTO WRN UPPER MI BEHIND FRONT. SEVERAL PIECES OF GUIDANCE SUGGEST DWPTS FALLING INTO THE UPPER 40S WHICH RESULTS IN RH FALLING TO AROUND 30PCT THIS AFTN. WITH WINDS GUSTING TO 20-25MPH THIS AFTN...THERE WILL BE AN INCREASED RISK OF WILDFIRES WHERE SIGNIFICANT RAINFALL HAS NOT OCCURRED RECENTLY. .LONG TERM...(TONIGHT THROUGH SUNDAY) ISSUED AT 518 AM EDT MON JUN 11 2012 FOR THE START OF THE PERIOD 00Z TUE...A MID LEVEL SHORTWAVE TROUGH AXIS WILL BE FROM WRN HUDSON BAY TO CENTRAL MN...WITH A SFC LOW OVER CENTRAL NRN ONTARIO. A COLD FRONT/SFC TROUGH WILL STRETCH S TO CENTRAL UPPER MI BY 00Z TUE. SOME SHOWERS AND THUNDERSTORMS WILL BE ONGOING ALONG AND AHEAD OF THE COLD FRONT...BUT THE DRY SLOT WILL BE MOVING IN AROUND THIS TIME DURING LOSS OF DAYTIME HEATING. THERE IS A POSSIBILITY OF SOME ELEVATED CONVECTION LATE IN THE EVENING OR EARLY OVERNIGHT...BUT I THINK THE DRY AIR WILL KEEP THAT FROM HAPPENING. WILL DEPICT PRECIP WITH CHANCE POPS MOVING OUT OF THE CWA BY 06Z TUE. BY 12Z TUE...THE 500MB TROUGH AXIS WILL BE FROM ERN HUDSON BAY TO WRN LAKE SUPERIOR...WITH THE SFC LOW NEAR JAMES BAY AND SFC HIGH PRESSURE MOVING INTO WRN MN. THE COLD FRONT WILL BE E OF THE CWA...WITH GOOD CAA IN THE WNW LOW LEVEL FLOW OVER THE AREA. 850MB TEMPS WILL BE AROUND 3C E AND -1C W. BY 18Z TUE...THE 500MB TROUGH AXIS WILL BE OVER THE CENTER OF THE CWA...WITH THE SFC HIGH BEGINNING TO MOVE INTO THE WRN CWA. 850MB TEMPS AT 18Z WILL RANGE FROM -2C N TO 2C S. BY 00Z WED...THE 500MB TROUGH AXIS WILL BE OVER FAR ERN UPPER MI...WHILE THE SFC HIGH WILL BE OVER MOST OF THE CWA. MODEL SOUNDING SUGGEST MIXING TO AROUND 825MB TUE...RESULTING IN HIGHS IN THE 50S N TO 60S S...AND LOW DEW PTS. THE SFC HIGH WILL BE CENTERED OVER THE CWA TUE NIGHT...WHICH WILL LEAD TO FROST POTENTIAL AS COOL TEMPS TUE DROP QUICKLY UNDER MOSTLY CLEAR SKIES. WENT WITH THE LOW SIDE OF TEMP GUIDANCE...WITH MANY LOCATIONS OVER THE INTERIOR DROPPING NEAR OR BELOW FREEZING. WILL KEEP MENTION OF FROST IN HWO. WED THROUGH FRI...THE SFC HIGH MOVES E WHILE SFC LOW PRESSURE DEVELOPS WELL TO OUR W IN RESPONSE TO A SERIES OF SHORTWAVES. THE RESULTING SLY FLOW IN THE LOW LEVELS BRINGS OFF AND ON CONVECTION FROM LATE WED THROUGH FRI...BUT MODELS INDICATE MOST OF THAT STAYING W OF THE CWA AND INTO WRN LAKE SUPERIOR. WILL KEEP FORECAST FOR UPPER MI DRY THROUGH THIS PERIOD AS A DRIER PATTERN HAS VERIFIED BETTER RECENTLY...AND MOST MODELS KEEP US DRY ANYWAYS. AN UPPER RIDGE WILL BUILD INTO THE AREA FROM THE S...BRINGING STEADILY INCREASING TEMPS WED THROUGH AT LEAST FRI. BY FRI...850MB TEMPS SHOULD BE UP TO 16C...THEN UP TO 18C ON SAT AND SUN. MODELS DIVERGE ON SOLUTIONS FOR THE WEEKEND...WITH THE 12Z/10 ECMWF BRINGING A TROUGH PUSHING IN FROM THE NW...WHILE THE 00Z/11 GFS KEEPS THE UPPER RIDGE IN PLACE. USED A CONSENSUS OF MODELS FOR THE WEEKEND GIVEN LOW CONFIDENCE IN ANY PARTICULAR MODEL SOLUTION. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 739 AM EDT MON JUN 11 2012 VFR CONDITIONS SHOULD PREVAIL THRU THIS FCST PERIOD AT KIWD/KCMX/KSAW. NARROW BAND OF SCT -SHRA/-TSRA PER CURRENT KMQT RADAR IMAGERY WILL LIKELY AFFECT KSAW UNTIL AROUND 14Z. OTHERWISE...AS COLD FRONT SLOWLY MOVES ACROSS THE AREA TODAY... POTENTIAL IS THERE FOR SHRA/TSRA TO REDEVELOP OVER CNTRL UPPER MI THIS AFTN. WITH CONSIDERABLE UNCERTAINTY IN PLACEMENT/COVERAGE OF ANY AFTN CONVECTION...SHRA/TSRA WERE NOT MENTIONED AT KSAW. WEST WINDS COULD BECOME GUSTY AND PICK UP SUBSTANTIALLY AT KIWD AND ESPECIALLY KCMX AS A SECONDARY COLD FRONT PASSES THRU THE AREA LATE AFTN/EVENING. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 518 AM EDT MON JUN 11 2012 AHEAD OF A COLD FRONT...S WINDS WILL BE IN THE 15-25KT RANGE OVER ERN LAKE SUPERIOR TODAY...ESPECIALLY EARLY IN THE DAY. SOME OF THE HIGHER OBSERVING PLATFORMS WILL SEE WINDS TO AROUND 30KT. BEHIND THE COLD FRONT...A PUSH OF STRONGER WESTERLY WINDS TO 25-30KT WILL ARRIVE OVER WRN LAKE SUPERIOR MID/LATE AFTN. THESE STRONGER WINDS WILL THEN SPREAD ACROSS THE LAKE TONIGHT. LOOK FOR THE WINDS TO GRADUALLY DIMINISH FROM W TO E TUE WITH WINDS FALLING BLO 15KT TUE NIGHT AS HIGH PRES ARRIVES OVER THE UPPER LAKES. WINDS WED THRU FRI SHOULD BE UNDER 20KT AS PRES GRADIENT REMAINS RELATIVELY WEAK BTWN THE DEPARTING HIGH AND A LOW PRES TROF SETTING UP WELL TO THE W AND NW. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
659 AM CDT MON JUN 11 2012 .UPDATE... 12Z AVIATION DISCUSSION ADDED BELOW. && .DISCUSSION... SHORTWAVE TROUGH CENTERED OVER LAKE WINNIPEG CANADA WILL CONTINUE TO LIFT NORTHEAST OVER THE UPPER GREAT LAKES TODAY. COLD POOL ALOFT ASSOCIATED WITH THE UPPER LEVEL LOW PRESSURE SYSTEM ALONG WITH ANY DAYTIME HEATING COULD GENERATE ISOLATED SHOWERS OVER THE FAR NORTHERN SECTION OF OUR FORECAST AREA LATE MORNING THROUGH MID AFTERNOON. ELSEWHERE...DRIER AIR WILL CONTINUE TO FILTER IN THROUGH TUESDAY. HIGHS TODAY WILL BE MUCH COOLER THAN PREVIOUS COUPLE OF DAYS WITH READINGS MAINLY IN THE 70S. HIGH PRESSURE WILL BEGIN TO BUILD OVER THE NORTHERN PLAINS THIS AFTERNOON AND OVER THE WESTERN GREAT LAKES AREA LATER TONIGHT AND TUESDAY. OVERNIGHT LOWS TONIGHT WILL COOL DOWN INTO THE 40S TO LOWER 50S. HIGHS ON TUESDAY WILL WARM BACK INTO THE UPPER 60S AND LOWER 70S. MEDIUM RANGE MODELS HAVE BEEN CONSISTENT WITH NEXT SHORTWAVE TROUGH FORECAST TO MOVE INTO THE UPPER MIDWEST WEDNESDAY NIGHT AND THURSDAY AS THE UPPER AIRFLOW BECOMES MORE ZONAL ACROSS THE NORTHERN TIER OF CONUS. WL KEEP SOME POPS GOING THROUGH THE REST OF THE WORK WEEK. UPPER HIGH PRESSURE RIDGE OVER THE EASTERN CONUS WILL RETROGRESS BACK WEST OVER THE MIDWEST BY THE END OF THE WORK WEEK AND WEEKEND. THE LATEST LONG TERM MODELS INDICATE A SPLIT UPPER AIR FLOW OVER THE UPPER MIDWEST. ECMWF MODEL KEEPS MUCH OF THE PRECIPITATION OVER NORTHERN HALF OF THE STATE. UPPER RIDGE WILL BRING MUCH OF THE EASTERN FORECAST AREA DRY CONDITIONS ALONG WITH MAX TEMPERATURES MODERATING INTO THE UPPER 80S. && .AVIATION.../12Z TAF ISSUANCE/ A FEW LINGERING IFR/MVFR CONDITIONS OVER WRN WI WILL QUICKLY GET PUSHED OUT BY DRIER AIR FROM THE WEST...WITH VFR CONDITIONS DOMINATING THIS TAF PERIOD. A SECONDARY BOUNDARY IS WORKING INTO WRN MN RIGHT NOW AND WILL WORK ACROSS MN THIS MORNING AND THROUGH EAU BY THE EARLY AFTERNOON. WINDS WILL BE SW OUT AHEAD OF THIS BOUNDARY...AND SWITCH TO THE W BEHIND WHILE ALSO PICKING UP IN STRENGTH. STRONGEST WINDS WILL BE OVER NW MN...BUT A FEW GUSTS AOA 30 KTS WILL BE POSSIBLE AT MAINLY AXN THIS AFTERNOON. FOR SHOWERS...THE RAP SHOWS SOME INSTABILITY DEVELOPING AHEAD OF THE BOUNDARY BY THE AFTERNOON...WITH THE HRRR GENERATING A LINE OF SHRA AS A RESULT. THE HRRR HAS BEEN DEVELOPING THESE SHOWERS FURTHER EAST WITH EACH SUCCESSIVE RUN...AND WHAT WAS NEAR MSP WITH THE 04Z RUN IS NOW NOT GETTING GENERATED UNTIL EAST OF EAU...WHICH IS WERE HIGHEST RISK OF FOR A BRIEF SHRA WILL EXIST. OTHERWISE...BKN CU FIELD AROUND 5K FT IS EXPECTED BY THE AFTERNOON DOWN TO THE TWIN CITIES...WITH A BRIEF MVFR CIG POSSIBLE AT AXN BETWEEN 14 AND 16Z. KMSP...FAVORED TAF WIND DIRECTIONS TOWARD THAT OF THE HRRR...WITH WINDS EXPECTED TO VEER TO THE WEST BY THE AFTERNOON. DO NOT EXPECT WINDS TO BE CONSISTENTLY NORTH OF 240 UNTIL AFTER 15Z...SO THERE COULD BE A FEW ISSUES WITH HAVING THE AIRPORT ON THE 30S HERE IN THE FIRST COUPLE OF HOURS. AFTER THAT...DO EXPECT BKN CIGS...BUT CAPPING INVERSION LOOKS TO BE LOW ENOUGH THIS AFTERNOON TO LIMIT ANY SHOWER POTENTIAL. ALSO...BASED ON WINDS ACROSS THE DAKOTAS ALL NIGHT...LOOKS GOOD TO SEE ANOTHER DAY OF GUSTS UP TO AROUND 30 KTS...EXCEPT THIS TIME WITH A WEST WIND. WILL SEE LIGHTER WINDS TUESDAY AS HIGH PRESSURE MOVES THROUGH. OUTLOOK... .TUE...VFR/SKC. WINDS NW 5-10 KTS. .WED...VFR WITH BRIEF PERIODS OF MVFR WITH SCTD SHRA/TSRA. WINDS S 10-15 KTS. .THU...CHC SHRA/TSRA. VFR...EXCEPT MVFR WITH ANY SHRA/TSRA. WINDS S AROUND 10 KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ JVM/MPG
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
633 AM CDT Mon Jun 11 2012 ...UPDATED AVIATION DISCUSSION... .DISCUSSION... Short Term (Tonight-Wednesday) Overnight, the focus was on two lines of convection: the leading line being the advancing gust front and the second line being focused along the cold front. The showers and thunderstorms along the gust front continued to weaken through the overnight hours, with the bit of remnant activity tracking southeast of the Missouri River by 09Z. The better area of convective activity was focused along the cold front that was stretching roughly along a line from North Kansas City to Cameron and Bethany around 09Z. The activity was remaining well below severe limits with 1000-1500 J/kg MUCAPE, weak shear, and poor lapse rates present. This line of thunderstorms had been fairly slow-moving, but has become a bit more progressive toward the southeast with the help of 20-25kt 850mb winds. This slow tracking was resulting in higher rainfall rates across extreme northeast Kansas and northwest Missouri, with some locations likely accumulating more than one inch of rain within an hour. HRRR shows the line of thunderstorms stretching along a Kansas City to Chillicothe line by around 10Z, progressing just south of the Missouri River by around 13Z. Short range models are in fairly good agreement that this thunderstorm activity will shift southeast of the forecast area late this morning, but cannot rule out a few lingering showers and thunderstorms across central Missouri early this afternoon. Winds will shift to the northwest behind the advancing cold front. However, cold air advection behind the cold front will be limited today so should see afternoon temperatures still warmer than normal -- into the middle 80s. High pressure will build in across the Northern and Central Plains later this afternoon and track toward the Great Lakes region by the middle of the week, keeping conditions dry. Temperatures look to be near to slightly above seasonal normals through Wednesday as winds shift from northeast to southeast with the eastward-moving surface high. As the upper level trough over the Northern Plains progresses toward the northern Great Lakes, a more zonal flow will set up across the western and central CONUS through mid-week. Models have shown the potential for a few disturbances to develop within the zonal flow primarily west of the forecast area across Kansas. Confidence is low in whether or not any of these impulses will spread enough eastward to clip eastern Kansas and extreme western Missouri Wednesday and Wednesday night, so have nothing more than slight chance pops in for that area. ACH Medium Range (Thursday through Sunday)... Prefer a wait and see approach as it relates to rain chances during the medium range period. The 00z ECMWF and GFS build mid level heights, with the ECMWF developing a closed high, across the mid MO River Valley while a western U.S. trough builds. While it`s certainly possible a weak vorticity lobe or two will meander across the Central Plains Thursday or Friday within a chaotic and weak westerly flow coming out of the Rockies, confidence is low on just how much convection, if any can make it into the CWA. Agree with the previous discussion in favoring the drier ECMWF over the relatively wet GFS. As such can only justify slight chance pops until the end late Sunday when falling heights across the Plains in response to the approaching upper trough offers some hope that increasing dynamics will generate some scattered convection. A gradual warm up on temperatures and dewpoints continues to look in order with readings in the upper 80s/90 by the weekend. MJ && .AVIATION... For the 12Z TAFs, the showers and thunderstorms that have developed along the cold front will continue to track southeastward through central and into southern Missouri this morning. Winds will shift to the northwest behind this passing front with dry conditions expected for the remainder of the period as high pressure begins to settle into the Northern and Central Plains. Some scattered mid-level clouds are possible through the day before clearing out by later this afternoon. ACH && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ WFO EAX
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
838 AM CDT MON JUN 11 2012 .UPDATE... HRRR AND RAP INDICATE LOWER 80S ACROSS SWRN NEB THIS AFTN. THE HRRR AND RAP WERE DEAD ON SUNDAY ACROSS THIS AREA SO THE FCST HAS BEEN UPDATED FOR SLIGHTLY WARMER TEMPS. REST OF FCST OKAY FOR NOW. && .PREV DISCUSSION... /ISSUED 640 AM CDT MON JUN 11 2012/ AVIATION... NO FLIGHT RESTRICTIONS ARE FORECAST THROUGH TONIGHT AND INTO TUESDAY MORNING. SMOKE FROM AT LEAST FOUR FIRES IN COLORADO WILL BE VISIBLE THROUGH TODAY AND BEYOND. BASED ON THE UPPER LEVEL WINDS... THE BASE OF THE SMOKE LAYER COULD BE AS LOW AS 7000 FEET AGL. HOWEVER...IT IS UNLIKELY THAT THE SMOKE WILL PRODUCE A CEILING. NORTHWEST WIND 300-330 IS EXPECTED TO INCREASE TO 12-18G21-27KT BY 15Z. WIND WILL THEN CONTINUE THUS UNTIL AFTER 01Z WHEN IT BECOMES LIGHT AND VARIABLE. PREV DISCUSSION... /ISSUED 300 AM CDT MON JUN 11 2012/ DISCUSSION... PACIFIC HIGH PRESSURE WILL BUILD EAST INTO THE CNTRL/NRN PLAINS TODAY. BREEZY NORTHWEST WINDS STARTING THE DAY BEHIND A SECONDARY COLD FRONTAL PASSAGE...WILL DIMINISH THIS AFTERNOON AS THE HIGH PRESSURE BUILDS IN. AIRMASS ACROSS THE AREA IS VERY DRY...WITH A DOWNSLOPE WIND COMPONENT AIDING THE DRYNESS. DEW POINTS GENERALLY IN THE 30S TODAY...WILL CREATE AFTERNOON RELATIVE HUMIDITY VALUES IN THE 15 TO 25 PERCENT RANGE. FORTUNATELY WINDS WILL BE DIMINISHING DURING THE PERIOD OF LOWEST RELATIVE HUMIDITY...SO FIRE WEATHER HEADLINES ARE NOT EXPECTED TO BE NEEDED. SOME GULF MOISTURE BEGINS TO RETURN NORTH INTO THE AREA TUESDAY...BUT REALLY DOESN/T GET INTO FULL SWING UNTIL TUESDAY NIGHT...WHEN H85 DEW POINTS RISE TO NEAR 14C ON SOUTHERLY LLJ. MODELS CONTINUE TO INDICATE A DECENT MID LEVEL WAVE WILL INTERACT WITH THE RETURNING MOISTURE...AND SCATTERED TSTM DEVELOPMENT IS POSSIBLE DURING THE AFTERNOON IN UPSLOPE ENVIRONMENT ACROSS THE NEB PANHANDLE/EASTERN WY AND CO. A LITTLE CONCERNED ABOUT THE LACK OF BETTER MOISTURE AT FIRST...SO WILL KEEP CHANCES SLIGHT TUESDAY AFTERNOON...AND INCREASE TO LOW CHANCE TUESDAY NIGHT AS STORMS MOVE EAST INTO AN INCREASINGLY FAVORABLE MOIST/UNSTABLE ENVIRONMENT DUE TO SOUTHERLY 45 KT LLJ. MID LEVEL WAVE AND CONVECTION SHOULD PUSH EAST OF THE AREA WEDNESDAY. A LARGE CLOSED LOW IS EXPECTED TO DEVELOP ACROSS SOUTHWEST CANADA BY THURSDAY. GFS ENSEMBLE MEAN KEEPS THE LOW INVOF SOUTHWEST CANADA THROUGH THE UPCOMING WEEKEND. BUILDING HEAT IS EXPECTED THURSDAY RIGHT THROUGH THE WEEKEND...AS ANY COLD FRONT ASSOCIATED WITH THE LOW STAYS WELL NORTHWEST OF THE AREA. RAIN CHANCES WILL NOT BE NIL HOWEVER...AS THE AREA APPEARS TO BE IN A RATHER ACTIVE SOUTHWEST FLOW ALOFT. LEEWARD TROUGHING DEVELOPS DAILY...AND THIS COULD SERVE FOR CONVECTIVE DEVELOPMENT. MOISTURE IS IN PLACE...WITH A DECENT TRAJECTORY OFF THE GULF DURING THE PERIOD. THE CAVEAT HERE IS POTENTIAL MID LEVEL WARM AIR...WHICH WOULD TEND TO CAP THE ATMOSPHERE. THIS WAS THE CASE THIS PAST WEEK...AND WON/T BE OVER AMBITIOUS WITH RAIN CHANCES AT THIS TIME. && .LBF WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM/EXTENDED...CDC AVIATION...BROOKS
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
559 AM CDT MON JUN 11 2012 .DISCUSSION... /ISSUED 449 AM CDT MON JUN 11 2012/ PRIMARY SHORT TERM FORECAST CONCERN REMAINS RAIN CHANCES. EARLY THIS MORNING... SHORTWAVE RIDGING WAS SPREADING INTO THE MIDSOUTH... IN THE WAKE OF AN UPPER LEVEL SHEAR AXIS THAT BROUGHT SCATTERED SHOWERS TO THE REGION ON SUNDAY. UPSTREAM OF THE SHORTWAVE RIDGE AXIS... A ROBUST LINEAR MCS WAS DROPPING SOUTHEAST THROUGH NW MISSOURI. 850/500MB THICKNESS ANALYSIS SUGGESTS THIS FEATURE MAY BEGIN A MORE SOUTHERLY PROPAGATION. KSGF VAD WIND PROFILER SHOWED 25KTS OF INFLOW...THOUGH THIS INFLOW SHOULD WEAKEN CONSIDERABLY FOLLOWING SUNRISE. AFTER A WEAKENING OF THE MO STORM COMPLEX... NAM MODEL REDEVELOPS STORMS OVER THE OZARK PLATEAU TOWARD MIDDAY. THIS APPEARS A REASONABLE SCENARIO...IN RESPONSE TO SURFACE HEATING... FALLING HEIGHTS AND INCREASING UPPER LEVEL DIFFLUENCE AHEAD OF A LONG WAVE TROF. SURFACED BASED INSTABILITY SHOULD BE IN GOOD SUPPLY ACROSS THE MIDSOUTH THIS AFTERNOON... WITH PARTIAL SUN AND LOWER 70S DEWPOINTS. DESPITE WEAK SHORTWAVE RIDGING...THE HIGH DEWPOINTS SHOULD MAKE CONVECTIVE TEMPS ATTAINABLE THIS AFTERNOON...ENOUGH TO WARRANT CHANCE POPS. MORE ORGANIZED CONVECTIVE ACTIVITY WILL BE POSSIBLE LATE THIS AFTERNOON AND EVENING. THE RIGHT ENTRANCE REGION OF AN UPPER JET CORE WILL INCREASE UPPER LEVEL DIFFLUENCE OVER THE MIDSOUTH... A PATTERN WHICH WILL WILL REMAIN RELATIVELY STATIC OVERNIGHT. THIS SUGGESTS ELEVATED STORMS MAY CONTINUE INTO THE OVERNIGHT... THROUGH MESOSCALE PROPAGATION PROCESSES WILL PLAY A LARGE ROLE ON WHERE STORMS OCCUR. A SURFACE COLD FRONT ARRIVES TUESDAY MORNING...BRINGING DRIER MIDCONTINENTAL AIR TO AREAS NORTH OF I40 BY AFTERNOON. 06Z NAM SUGGESTS THE FRONT MAY HANG UP OVER NORTH MS TUESDAY AFTERNOON... PROVIDING FOCUS FOR ADDITIONAL THUNDERSTORMS. WEDNESDAY WILL SEE DRIER AIR OVER ALL THE MIDSOUTH. TEMPERATURES WILL RECOVER TO NEAR OR SLIGHTLY ABOVE NORMAL VALUES FOR THE LATTER HALF OF THE WEEK. BY FRIDAY... DEWPOINTS RECOVER TO THE 60S. DRY CONDITIONS WILL PREVAIL...THOUGH CANNOT RULE OUT AN ISOLATED AFTERNOON THUNDERSTORM OR TWO UNDER AN UPPER LEVEL SYNOPTIC SCALE RIDGE. PWB && .AVIATION... 12Z TAF SET COLD FRONT EXPECTED TO MOVE INTO THE CWA OVERNIGHT. HRRR MODEL HAS INITIALIZED THE BEST WITH ONGOING ACTIVITY UP ACROSS MISSOURI THUS HAVE LEANED TOWARD THIS SOLUTION WITH NEW TAF SET. EXPECT POSSIBLY TWO ROUNDS OF SHRA/TSRA ACTIVITY. FIRST...MODEL INDICATING A TSRA COMPLEX DEVELOPING OVER NW ARKANSAS/SW MISSOURI AROUND 17-18Z. MCS WILL PUSH EAST INTO KJBR AFTER 20Z AND POSSIBLY INTO KMEM AFTER 21Z. HAVE ADDED TEMPO GROUPS TO NEW TAF AS A RESULT. NAM ALSO SHOWS THIS FIRST ROUND OF ACTIVITY OCCURRING. THEREAFTER...CONFIDENCE WANES AS HOW FAR EAST AND SOUTH COMPLEX WILL PUSH. A SECOND ROUND OF ACTIVITY COULD OCCUR ALONG FRONT AS IT PUSHES INTO THE AREA. FOR NOW JUST LEFT VCTS WORDING AS CONFIDENCE IS LOW AS EARLIER TSRA COMPLEX (IF IT DOES DEVELOP) COULD STABILIZE THE ATMOSPHERE KILLING ANY ACTIVITY PUSHING INTO THE AREA ALONG THE FRONT. IF HAD TO PICK BEST TIMING AT KMEM FOR SECOND ROUND ACTIVITY TO OCCUR WOULD PICK SOMEWHERE BETWEEN 6Z- 10Z. OTHERWISE...IFR CIGS CURRENTLY OCCURRING SHOULD LIFT TO VFR BY 15-19Z DEPENDING ON LOCATION. SW WINDS BETWEEN 8-12 KTS EXPECTED TODAY...SPEEDS WILL DECREASE AFTER 01Z. KRM && && .PRELIMINARY POINT TEMPS/POPS... MEM 90 74 87 65 / 40 50 40 10 MKL 87 69 85 59 / 40 50 40 0 JBR 88 67 86 61 / 40 50 10 0 TUP 88 71 86 65 / 40 60 60 10 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
645 AM CDT MON JUN 11 2012 .SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT 330 AM CDT MON JUN 11 2012 MAIN FORECAST CONCERN IS ON TEMPERATURES THROUGHOUT THE SHORT TERM. CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED RIDGING OVER BRITISH COLUMBIA AND THE EASTERN GREAT LAKES... WITH TROUGHING IN-BETWEEN FROM SOUTH CENTRAL CANADA INTO THE NORTHERN PLAINS. WITHIN THIS TROUGH...A FAIRLY POTENT SHORTWAVE STRETCHED FROM NORTHERN MN SOUTHWEST INTO SOUTHEAST SOUTH DAKOTA... WHICH IS EVIDENT BY A DEEP DRY SLOT ON WATER VAPOR AND CLEAR SKIES ON IR IMAGERY. 00Z ABR SOUNDING IN THE DRY SLOT WAS VERY DRY WITH A PRECIPITABLE WATER OF 0.51 INCHES. AHEAD OF THE SHORTWAVE...AN AREA OF CONVECTION STRETCHED FROM NORTHERN WI SOUTH INTO FAR NORTHEAST IA/SOUTHWEST WI AND TO THE KANSAS CITY AREA. THE STRONGEST CONVECTION HAS SHIFTED TO THE SOUTHERN END OF THIS LINE...DUE TO BETTER LOW LEVEL CONVERGENCE SEEN IN 925 AND 850MB PROFILER DATA. CONVECTION THAT WAS OVER MN LAST EVENING HAS WEAKENED...DUE TO THE BETTER LOW LEVEL CONVERGENCE AND MOISTURE TRANSPORT SHIFTING SOUTH...DECREASING INSTABILITY AHEAD OF THE CONVECTION...AS WELL AS RAP LOW TO MID LEVEL FRONTOGENESIS FIELDS INDICATING WEAKENING THROUGH THE NIGHT. THE ONE CAVEAT TO THIS IS AN MCV RIDING NORTHEAST...ENTERING THE LA CROSSE AREA AS OF 08Z. ON ITS SOUTHEAST SIDE...THE COMBINATION OF DCAPE AROUND 1000 J/KG PER RAP ANALYSIS AND STORMS LINED ORTHOGONAL TO THE 0-3KM SHEAR VECTOR HAS HELPED PRODUCE SOME STRONG TO POSSIBLY DAMAGING WIND GUSTS. AT THE SURFACE...A COLD FRONT WAS PRESENT JUST BEHIND THE CONVECTION... STRETCHING FROM NEAR THUNDER BAY ONTARIO TO LA CROSSE WI. A SECONDARY COLD FRONT WAS PRESENT IN NORTHWEST MN. IN THE WAKE OF THIS FRONT...SATELLITE IMAGERY AND OBSERVATION SHOWED LOW CLOUDS... ISOLATED LIGHT SHOWERS AND MUCH COOLER TEMPERATURES IN THE 50S. TODAY AND TONIGHT...UPPER TROUGHING OVER SOUTH CENTRAL CANADA AND THE NORTHERN PLAINS IS FORECAST TO CONTINUE AN EAST-NORTHEASTWARD MOVEMENT...BEING PROPELLED BY THE CURRENT POTENT SHORTWAVE IN MN AND A SECOND ONE DROPPING DOWN THE BACK SIDE OF THE TROUGH. ALTHOUGH THE BULK OF THE TROUGH LIFTS INTO MANITOBA...NORTHWEST ONTARIO AND LAKE SUPERIOR...SOME OF THE TROUGHING WILL EXTEND DOWN INTO THE FORECAST AREA BY TONIGHT. IN SUMMARY...EXPECT THE TROUGH TO BRING A COOL DOWN FROM WHAT HAS BEEN SEEN LATELY. FIRST ISSUE TO CONTEND WITH IS THE ONGOING SHOWERS AND EMBEDDED THUNDERSTORMS. LATEST HRRR/RAP GUIDANCE AS WELL AS 11.00Z NAM SUGGESTS THE PRECIPITATION MAY BE COMPLETELY EAST OF THE AREA BY 12Z. LOOKS LIKE THERE SHOULD BE A BREAK AS INSTABILITY TRIES TO BUILD AHEAD OF THE MAIN COLD FRONT. HOWEVER...THE MAIN COLD FRONT WILL BE EAST OF THE AREA BEFORE IT CONVECTS...LIKELY BETWEEN 18-21Z. ATTENTION THEN TURNS TO THE SECONDARY COLD FRONT. THIS COMES THROUGH IN THE AFTERNOON...WITH WINDS INCREASING OUT OF THE WEST BEHIND IT. NO PRECIPITATION ANTICIPATED...BUT SOME STRATOCUMULUS AS SEEN BACK IN THE DAKOTAS SHOULD FILTER IN. THESE CLOUDS WILL LIKELY BECOME CELLULAR RESULTING FROM THE STRONG JUNE SUN...THUS DISSIPATING WITH LOSS OF HEATING IN THE EVENING. 850MB TEMPS OF 12-16C AT 18Z PLUS PLENTY OF SUN AND DRY AIR AHEAD OF THE SECONDARY COLD FRONT SHOULD ALLOW TEMPERATURES TO CLIMB INTO THE UPPER 70S TO MID 80S. TEMPERATURES MAY FALL SLIGHTLY ONCE THE SECONDARY FRONT MOVES IN. BETTER TEMPERATURE FALL EXPECTED TONIGHT AIDED BY NOCTURNAL COOLING AND CONTINUED COLD ADVECTION ON BREEZY NORTHWEST WINDS. BY 12Z TUESDAY...850MB TEMPS ARE PROGGED TO DROP AT LEAST DOWN TO 4-7C...AND PERHAPS SLIGHTLY COOLER AS INDICATED BY THE NAM. WENT WITH A BLEND OF GUIDANCE FOR LOWS...RESULTING IN UPPER 40S TO MID 50S. TUESDAY AND TUESDAY NIGHT...UPPER FLOW IS PROGGED TO GRADUALLY TURN ZONAL DURING THIS PERIOD AS THE UPPER TROUGHING LIFTS AWAY FROM THE AREA. WITHIN THE ZONAL FLOW...A SHORTWAVE IS INDICATED TO REACH CENTRAL SOUTH DAKOTA BY 12Z WEDNESDAY. SOME MID/HIGH CLOUDS ASSOCIATED WITH ISENTROPIC LIFT AHEAD OF THIS SHORTWAVE COULD GET INTO SOUTHEAST MN AND NORTHEAST IA LATE IN THE NIGHT. OTHERWISE... PLENTY OF DRY AIR NOTED BY PRECIPITABLE WATER VALUES OF 0.5 INCH OR LESS SHOULD KEEP SKIES CLEAR. ALTHOUGH THE DRY AIR AND CLEAR SKIES ARE FAVORABLE FOR WARMING...TEMPERATURES ON TUESDAY MAY STRUGGLE GIVEN 850MB TEMPS PROGGED TO STILL BE AT 4-7C AT 18Z. IN FACT...TAYLOR COUNTY MAY ONLY BE AROUND 2C. THESE ARE 2 STANDARD DEVIATIONS BELOW NORMAL. AS A RESULT...ONLY FORECAST HIGHS IN THE MID 60S TO LOW 70S...20 DEGREES COLDER THAN YESTERDAY. DEWPOINTS ARE LIKELY TO TANK FROM MIXING OF THE DRY AIR. SHOULD BE BREEZY TOO IN THE MORNING ADDING AN EXTRA CHILL BEFORE SURFACE HIGH PRESSURE BUILDS OVERHEAD IN THE EVENING TO CALM WINDS. THIS SETS THE STAGE FOR GOOD RADIATIONAL COOLING TUESDAY NIGHT...ESPECIALLY IN WISCONSIN. WOULD NOT BE SURPRISED TO HAVE SOME UPPER 30S FOR LOWS IN THE TYPICAL COLD SPOTS. WARMER READINGS ARE EXPECTED WEST OF THE MISSISSIPPI RIVER WHERE RETURN FLOW AND CLOUDS COME IN. WEDNESDAY AND WEDNESDAY NIGHT...UPPER LEVEL FLOW LOOKS TO AMPLIFY AGAIN AS TROUGHING DROPS DOWN INTO SOUTHWEST CANADA AND THE PACIFIC NORTHWEST BY 12Z THURSDAY. THIS AMPLIFICATION SHOULD HELP TAKE THE SHORTWAVE THAT WAS COMING INTO SOUTH DAKOTA TUESDAY NIGHT AND LIFT IT WELL NORTHWEST OF THE AREA. BY 00Z THURSDAY...ALL MODELS HAVE IT CROSSING CENTRAL OR NORTHERN MN. GIVEN DRY LOW LEVEL AIRMASS IN PLACE BY THE SURFACE HIGH PRESSURE AREA...AS WELL AS THE TRACK OF THE SHORTWAVE...NOT ANTICIPATING ANY PRECIPITATION TO SPREAD INTO THE FORECAST AREA. HOWEVER...CLOUD COVER IS AN ISSUE. INCREASING 305-310 K ISENTROPIC LIFT EAST OF THE SHORTWAVE SHOULD SPREAD MID AND HIGH CLOUDS ACROSS MUCH OF THE AREA ON WEDNESDAY. THESE CLOUDS MAY LIMITING HEATING SOMEWHAT...DESPITE WARMER 850MB TEMPS IN THE 8-12C RANGE. KEPT HIGHS IN THE LOW TO MID 70S...WHICH ARE ABOUT 5 DEGREES COOLER THAN WHAT THEY COULD BE IF FULL SUN WAS OBSERVED. THE CLOUDS DO LOOK TO CLEAR OUT WEDNESDAY NIGHT AS THE SHORTWAVE HEADS INTO ONTARIO. FOLLOWED A BLEND OF GUIDANCE FOR LOWS GIVEN NO STRONG SIGNAL TO GO COLDER OR WARMER. .LONG TERM...THURSDAY THROUGH SUNDAY NIGHT 330 AM CDT MON JUN 11 2012 11.00Z ECMWF/CANADIAN/GFS AND GFS ENSEMBLES REMAIN IN PRETTY GOOD AGREEMENT ON THE UPPER LEVEL PATTERN...AND IN FACT ARE IN BETTER AGREEMENT NOW COMPARED TO YESTERDAY. CONSENSUS IS THAT TROUGHING WILL HOLD OVER THE NORTHWESTERN U.S. THROUGH MUCH OF THE LONG TERM PERIOD...RESULTING IN STRENGTHENING RIDGING DOWNSTREAM OVER THE WESTERN GREAT LAKES. IN FACT...BY SUNDAY NIGHT WHEN MODELS HAVE THE TROUGH DIGGING MORE INTO THE NORTHERN ROCKIES...THE RIDGE DOWNSTREAM REALLY STRENGTHENS. IT APPEARS THAT MOST OF THE SHORTWAVES EJECTING OUT OF THE TROUGH WILL END UP STAYING MOSTLY TO THE NORTHWEST OF THE AREA. THUS...OVERALL MUCH OF THIS LONG TERM FORECAST LOOKS DRY. HAVE MAINTAINED SOME 20-30 PERCENT CHANCES OVER NORTHWEST PORTIONS OF THE AREA ON SATURDAY...NORTH OF I-90 SATURDAY NIGHT AND ACROSS THE ENTIRE AREA SUNDAY INTO SUNDAY NIGHT. THESE MOSTLY STEM FROM BEING ON THE NOSE OF SOME MOISTURE TRANSPORT AND SHORTWAVES COMING CLOSE TO THE AREA. HOWEVER...IT IS POSSIBLE THESE CHANCES MAY BE ABLE TO BE REMOVED IN LATER FORECASTS WITH MODELS TRENDING DRIER. ONE OTHER PERIOD TO WATCH IS THURSDAY WITH THE 11.00Z ECMWF BEING REALLY AGGRESSIVE IN DEVELOPING PRECIPITATION OVER MN. THIS APPEARS TO BE RELATED TO A SURGE OF WARM...MOIST AIR OCCURRING WITH THE BUILDING RIDGING. GIVEN THAT THE MODEL DOES NOT BRING THE PRECIPITATION INTO THE AREA AND OTHER MODELS SUGGESTING DRIER...HAVE KEPT THURSDAY DRY. WHAT COULD BE MORE SIGNIFICANT FOR THE LONG TERM FORECAST IS TEMPERATURES. WITH THE AREA NOW STRONGLY FORECAST TO BE UNDER RIDGING...AND IN BROAD BREEZY SOUTHERLY FLOW...WE COULD BE DEALING WITH ANOTHER LONG STRETCH OF 80S AND PERHAPS 90S. NEW ECMWF REALLY CAME IN WARM...WITH 850MB TEMPS FRIDAY THROUGH MONDAY HOVERING AROUND 20C OR SO...RESULTING IN HIGHS OF 90-95. HAVE BOOSTED TEMPERATURES UP ABOVE THE CONSENSUS AND THESE MAY STILL BE TOO COOL. && .AVIATION...TODAY AND TONIGHT 645 AM CDT MON JUN 11 2012 CONCERNS DEAL WITH A FEW LOW CLOUDS THIS MORNING...THEN WINDS THROUGH THE REST OF TODAY. CURRENTLY WATCHING A COLD FRONT MOVE EAST OF THE MISSISSIPPI INTO CENTRAL WISCONSIN...BRINGING LINE OF SHRA/TS WITH IT. LOOSE GRADIENT IMMEDIATELY BEHIND THE FRONT PRODUCING LIGHT WINDS AT KRST/KLSE TAF SITES EARLY THIS MORNING. LIGHTER WINDS AND RESIDUAL LOWER BOUNDARY LAYER MOISTURE FROM OVERNIGHT RAINFALL WAS ALLOWING POCKETS OF STRATUS TO DEVELOP. SO FAR...STRATUS WITH BASES AOB 600 FEET SCATTERED IN NATURE AND IS EXPECTED TO DISSIPATE 13-14Z AS WINDS START TO VEER TO THE WEST AND DRYING OF THE BOUNDARY LAYER TAKES PLACE. LOOK FOR THE PRESSURE GRADIENT AND RESULTANT WEST WINDS TO INCREASE BY 16Z WITH GUSTS IN THE 20-30KT RANGE PREVALENT BY AFTERNOON. SCATTERED CUMULUS WITH BASES 4-5KFT EXPECTED TO DEVELOP BY MIDDAY AS AN UPPER LEVEL TROUGH SWINGS ACROSS THE DAKOTAS INTO THE UPPER MISSISSIPPI RIVER VALLEY REGION. LOOK FOR THE WINDS TO SUBSIDE AND CUMULUS TO DISSIPATE TOWARD SUNSET. MOSTLY CLEAR/VFR CONDITIONS EXPECTED OVERNIGHT AS HIGH PRESSURE BUILDS IN FROM THE NORTHERN PLAINS. && .ARX WATCHES/WARNINGS/ADVISORIES... 330 AM CDT MON JUN 11 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...DAS
AREA FORECAST DISCUSSION
NWS ALBANY NY
158 PM EDT MON JUN 11 2012 .SYNOPSIS... HIGH PRESSURE ALOFT WILL BUILD INTO THE REGION THROUGH TODAY...WITH WARM AND SOMEWHAT HUMID CONDITIONS THROUGH TONIGHT. AN ISOLATED AFTERNOON SHOWER OR THUNDERSTORM WILL BE POSSIBLE ACROSS PORTIONS OF THE WESTERN MOHAWK VALLEY AND ADIRONDACKS. WIDESPREAD SHOWERS AND THUNDERSTORMS WILL RETURN FOR TUESDAY INTO EARLY WEDNESDAY... ASSOCIATED WITH A PERIOD OF MODERATE TO HEAVY RAINFALL AS A FRONTAL BOUNDARY SLOWLY CROSSES THE REGION. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1230 PM...ISOLATED CONVECTION HAS DEVELOPED OVER THE ADIRONDACK ZONES SO WILL LEAVE THE SLIGHT CHANCE POPS IN THAT AREA AND THE MOHAWK VALLEY AS WELL. HAVE LEFT HIGH TEMP FORECAST FOR TODAY AS IS...OR RAISED BY A FEW DEGREES...ESPECIALLY ACROSS THE NORTHWEST PART OF THE FORECSAT AREA. ****PREVIOUS DISCUSSION**** AS OF 935 AM EDT...STRATUS CLOUDS CONTINUE TO EXPAND N AND W...ACROSS NW CT...THE MID HUDSON VALLEY REGION AND BERKSHIRES...AS WELL AS ACROSS THE SE CATSKILLS. AREAS OF LOW CLOUDS/FOG ACROSS THE WESTERN ADIRONDACKS...AND PORTIONS OF THE HELDERBERGS APPEARS TO BE DECREASING. HAVE MADE SOME CHANGES TO GRIDDED DATABASE BASED ON RECENT OBS...12Z UA SOUNDINGS...AND LATEST RAP/HRRR. FIRST WAS TO EXPAND THE SLIGHT CHC POPS A BIT FURTHER SOUTH INTO THE CENTRAL AND WESTERN MOHAWK VALLEY. THE LATEST RAP AND HRRR CONTINUE TO INDICATE POCKETS OF FAIRLY DECENT INSTABILITY DEVELOPING THIS AFTERNOON IN THIS REGION. IN ADDITION...THIS REGION WILL BE CLOSER TO A WEAK BOUNDARY...SEPARATING A SLIGHTLY COOLER MODIFIED MARINE AIR MASS TO THE E AND S...FROM A WARMER...MORE CONTINENTAL AIR MASS TO THE N AND W. ELSEWHERE...HAVE INCREASED CLOUDS COVERAGE AND LOWERED MAX TEMPS ACROSS WESTERN NEW ENGLAND...AND THE MID HUDSON VALLEY REGION. AS THE AFOREMENTIONED MODIFIED MARINE AIR CONTINUES TO WORK N AND W...MAX TEMPS MAY FAIL TO REACH 80 ACROSS THE BERKSHIRES/SOUTHERN GREENS...LITCHFIELD CO AND THE MID HUDSON VALLEY. ELSEWHERE...STILL EXPECT MAXES TO REACH 80-85 ACROSS THE UPPER HUDSON VALLEY FROM ALBANY NORTH...AND MID 80S ACROSS THE CENTRAL AND WESTERN MOHAWK VALLEY...WHERE EVEN SOME UPPER 80S ARE POSSIBLE. WILL NEED TO WATCH HOW FAR N AND W THE LOWER CLOUDS REACH...AS THIS MAY REQUIRE ADDITIONAL MODIFICATIONS TO MAX TEMPS/TOWARD LOWER VALUES/WITHIN THE CAPITAL REGION SHOULD MORE CLOUDS FORM. FOR TONIGHT...ANY CONVECTION SHOULD QUICKLY DISSIPATE THIS EVENING AS THE UPPER LEVEL RIDGE AXIS SLIDES FURTHER OFFSHORE. THIS WILL ALLOW THE UPSTREAM NORTHERN PLAINS TROUGH TO MIGRATE FURTHER EAST TOWARD THE CENTRAL GREAT LAKES REGION. ALONG WITH ITS APPROACH...MOISTURE ADVECTION FROM THE SOUTHEAST CONUS AND OHIO VALLEY WILL ADVANCE NORTHWARD. FORECAST SOUNDINGS SUPPORT AN ENTRAINMENT OF LOW LEVEL STRATUS FROM THE ATLANTIC YET RATHER DRY BETWEEN 850-500MB TO KEEP THE CHANCE OF PRECIP WEST OF THE REGION. EXPECTATIONS ARE FOR AN INCREASING CLOUD COVER AND A MILD OVERNIGHT WITH LOWS MAINLY INTO THE 60S. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... RAINFALL POTENTIAL INCREASES FROM WEST TO EAST AS THE LOW LEVEL JET INCREASES TO >40KTS TO ASSIST WITH RAPID MOISTURE TRANSPORT INTO THE CWFA. NCEP MODEL SUITE ARE IN EXCELLENT AGREEMENT WITH A PERIOD OF MODERATE RAINFALL TO MOVE ACROSS THE REGION ON TUESDAY. INSTABILITY PARAMETERS ARE NOT FAVORABLE FOR SEVERE WEATHER...HOWEVER...MID LEVEL VALUES PER THE SHOWALTERS STILL SUPPORT EMBEDDED DEEPER CONVECTION. PWATS ARE PROGGED TO CLIMB IN EXCESS OF 1.75" WITH UPSTREAM VALUES CLOSE TO 2.00". THESE VALUES ARE 2-3 STANDARD DEVIATIONS ABOVE NORMAL TO SUPPORT EMBEDDED PERIODS OF HEAVY RAINFALL. FAVORED UPSLOPE REGIONS OF THE CATSKILLS...NW CT INTO THE BERKS AND SOUTHERN VT MAY ENHANCE RAINFALL RATES. SEE THE HYDRO DISCUSSION FOR FURTHER DETAILS ON THE RAINFALL POTENTIAL IMPACTS. OTHERWISE...RATHER HIGH POPS EXPECTED DURING THE DAY WITH TEMPERATURES A BIT COOLER DUE TO THE MARINE INFLUENCE...CLOUDS AND PRECIP WITH HIGHS MAINLY IN THE MID 60S TO LOWER 70S. MODELS HAVE COME AROUND TO THE ECMWF OF THE PAST SEVERAL DAYS WITH A MORE PROGRESSIVE FROPA TUESDAY EVENING. SO WE WILL GRADUALLY LOWER POPS FROM WEST TO EAST ALONG WITH IMPROVEMENTS TO THE SKY COVER. HOWEVER...EAST OF THE HUDSON RIVER...THOSE CLOUDS WILL LIKELY LINGER LONGER UNTIL THE FRONT HAS CLEARED THE EASTERN SEABOARD. CONFIDENCE CONTINUES TO INCREASE THAT WEDNESDAY SHOULD TURN OUT TO BE A DRIER DAY. WHILE THE MID LEVELS OF THE ATMOSPHERE ARE EXPECTED TO REMAIN RATHER DRY...LOWER LEVELS WILL LIKELY REMAIN A BIT MORE MOIST DUE TO THE RAINFALL FROM TUESDAY EVENT AND LOW LEVEL NORTHEAST WIND TRAJECTORIES. SCT-BKN CLOUDS ARE EXPECTED FOR OUT ADJACENT WESTERN NEW ENGLAND COUNTIES WITH DOWNSLOPING COMPONENT INTO THE HUDSON RIVER VALLEY FOR AT LEAST A PTSUNNY DAY. AS FOR TEMPERATURES...A MODEL BLEND APPROACH WAS UTILIZED WHICH DOWNPLAYS THE COOLER VALUES WITHIN THE GFS MOS AND THE MUCH WARMER VALUES SEEN IN THE MET MOS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... THE MODELS HAVE STARTED TO COME INTO BETTER AGREEMENT REGARDING THE EXTENDED PERIOD...FOR THE PERIOD BEGINNING ON WEDNESDAY EVENING. AT THIS POINT...IT APPEARS THAT THE UPPER TROUGH RESPONSIBLE FOR BRINGING THE MID WEEK WET WEATHER WILL BE PROGRESSIVE AND CONTINUE TO MOVE EASTWARD ACROSS CANADA. ALTHOUGH THE SURFACE FRONTAL BOUNDARY WON/T MAKE A CLEAN SWEEP OUT TO SEA...IT LOOKS TO GENERALLY WASH OUT ACROSS NEW ENGLAND TO THE EAST OF OUR REGION. ALSO...WHILE IT STILL APPEARS THAT A SURFACE WAVE MAY DEVELOP ALONG THIS FRONT...THE LATEST 00 UTC ECMWF/GFS BOTH SHOW A WEAK LOW REMAINING OFF THE COAST...WITH HIGH PRESSURE BUILDING INTO OUR AREA FROM SOUTHERN CANADA. WHILE WE STILL MAY HAVE A LOW CHC/SLIGHT CHC FOR A RAIN SHOWER ACROSS THE REGION /ESP FOR EASTERN AREAS/ FOR WED NIGHT INTO THURSDAY DUE TO THE PROXIMITY OF THE SFC BOUNDARY...IT DOESN/T APPEAR TO BE A WASHOUT BY ANY STRETCH. SKIES LOOK TO RANGE FROM PARTLY CLOUDY IN WESTERN AREAS...TO MOSTLY CLOUDY FOR WESTERN NEW ENGLAND...DUE TO THE WEAK NE SURFACE FLOW IN PLACE. MIN TEMPS LOOK TO RANGE FROM THE MID 40S TO UPPER 50S FOR WED NIGHT...WITH MAX TEMPS GENERALLY IN THE 70S ON THURSDAY. STRONG UPPER RIDGING LOOKS TO BUILD INTO THE REGION FOR FRIDAY INTO THE WEEKEND AS A RIDGE OVER THE GREAT LAKES BENDS NORTHEASTWARD INTO OUR AREA. ALTHOUGH THE MODELS SHOW A CLOSED OFF 500 HPA LOW ACROSS THE WESTERN ATLANTIC...IT LOOKS TO STAY FAR ENOUGH EAST OF OUR AREA TO BE OF ANY CONCERN FOR US. WITH THE BUILDING RIDGE...AND WARMING TEMPS ALOFT...ENOUGH OF A CAP LOOKS TO BE IN PLACE TO PREVENT ANY CONVECTION FROM FIRING UP...SO HAVE GONE WITH A DRY FORECAST FOR FRIDAY ONWARD. VALLEY MAX TEMPS SHOULD BE GRADUALLY WARMER AND WARMER EACH DAY...WITH UPPER 70S TO NEAR 80 FOR FRIDAY...LOW 80S FOR SATURDAY...AND LOW TO MID 80S FOR SUNDAY. SKIES GENERALLY LOOK MOSTLY CLEAR TO PARTLY CLOUDY. AT THIS POINT...DEWPOINTS DON/T LOOK TOO MUGGY JUST YET...WITH TDS GENERALLY IN THE 50S F. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... HIGH PRESSURE WILL REMAIN ANCHORED OFF THE NEW ENGLAND COAST THROUGH TONIGHT. A WARM FRONT APPROACHING FROM THE SOUTHWEST WILL SPREAD CLOUDS...AND SHOWERS INTO THE REGION FOR TUESDAY AFTERNOON AND NIGHT. EXPECT VFR CONDITIONS THROUGH AT LEAST EARLY TONIGHT. THEN...AS A MOIST S/SE FLOW CONTINUES...SOME LOW CLOUDS ARE EXPECTED TO DEVELOP AND SPREAD NORTHWARD AFTER 06Z/TUE. THIS SHOULD LEAD TO MVFR CIGS DEVELOPING PRIOR TO 12Z/TUE...WITH A CHANCE FOR IFR CIGS AT KPSF...AND POSSIBLY KPOU. THERE IS A SLIGHT CHANCE THAT IFR CIGS MAY SPREAD EVEN FURTHER N...BUT AT THIS TIME...CONFIDENCE NOT QUITE HIGH ENOUGH TO INCLUDE AT KALB/KGFL. AREAS OF MVFR CIGS WILL LINGER THROUGH 14Z-15Z/TUE...WITH SOME POSSIBILITY OF IMPROVEMENT INTO THE LOW VFR RANGE THEREAFTER. HOWEVER...SHOWERS SHOULD DEVELOP ACROSS WESTERN AND CENTRAL NYS DURING THE MORNING...AND MAY IMPACT TAF SITES WEST OF THE HUDSON RIVER AFTER 16Z/TUE. SOUTH TO SOUTHEAST WINDS WILL REMAIN AT 8-12 KT THIS AFTERNOON...WITH SOME GUSTS OF 20-25 KT POSSIBLE...ESP AT KALB DUE TO FUNNELING EFFECTS UP THE HUDSON RIVER VALLEY. SOUTH TO SOUTHEAST WINDS WILL DIMINISH TO 5-10 KT TONIGHT...THEN INCREASE AGAIN TO 8-12 KT TUE MORNING...WITH SOME GUSTS OF 20-25 KT POSSIBLE. OUTLOOK... TUE-TUE NT...VFR/MVFR. CHC IFR. AFTERNOON SHRA/TSRA LIKELY. WED...VFR/MVFR. SHRA POSSIBLE EARLY. THU/SAT...VFR. SLIGHT CHC -SHRA. CHC LATE NIGHT/EARLY MORNING MVFR/IFR IN FOG/STRATUS. && .FIRE WEATHER... NO FIRE WEATHER CONCERNS ARE EXPECTED OVER THE NEXT SEVERAL DAYS. A SOUTH TO SOUTHEAST WIND WILL INCREASE TO AROUND 10 MPH TODAY WITH DRY WEATHER EXPECTED. AFTERNOON RH VALUES WILL DROP INTO THE 35-50 PERCENT...HIGHEST TO THE WEST OF ALBANY. MINIMUM RH VALUES TONIGHT REBOUND TO GREATER THAN 80 PERCENT. A WETTING RAIN IS EXPECTED ON TUESDAY TO FURTHER REDUCE FIRE WEATHER CONCERNS. && .HYDROLOGY... A MODERATE RAINFALL EVENT IS EXPECTED ON TUESDAY ACROSS THE HYDRO SERVICE AREA. LATEST MODEL GUIDANCE SUPPORTS A ROBUST MOISTURE TRANSPORT THAT SHOULD GENERATE AT LEAST BROKEN COVERAGE OF MODERATE TO HEAVY EMBEDDED CONVECTIVE RAINFALL RATES. EXPECTING THE RAINFALL TO BE OROGRAPHICALLY ENHANCED ACROSS PORTIONS OF THE CATSKILLS....BERKSHIRES AND SOUTHERN GREENS. PWAT ANOMALIES OF 2 TO 3 STD DEV ABOVE NORMAL...A >40 KT SOUTHERLY LOW LEVEL JET HELPING TO ENHANCE ISENTROPIC LIFT AND OROGRAPHICS SHOULD HELP ENHANCE RAINFALL RATES...AND THUS EXPECTING SOME LOCALLY HEAVIER TOTALS FOR THE EVENT AT OR ABOVE 2 INCHES. THIS SHOULD PRODUCE RISES ON AREA RIVERS AND STREAMS...BUT NO FLOODING IS EXPECTED ON THE STREAMS AND RIVERS. LATEST RUN OF THE MMEFS GUIDANCE ALSO SUPPORT THIS IDEA WITH NO POINTS EXPECTED TO CLIMB ABOVE FLOOD STAGE. 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...GJM/KL/BGM NEAR TERM...GJM/KL/BGM SHORT TERM...BGM LONG TERM...FRUGIS AVIATION...KL FIRE WEATHER...BGM HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
142 PM EDT MON JUN 11 2012 .SYNOPSIS... HIGH PRESSURE ALOFT WILL BUILD INTO THE REGION THROUGH TODAY...WITH WARM AND SOMEWHAT HUMID CONDITIONS THROUGH TONIGHT. WIDESPREAD SHOWERS AND THUNDERSTORMS WILL RETURN FOR TUESDAY INTO EARLY WEDNESDAY ASSOCIATED WITH A PERIOD OF MODERATE TO HEAVY RAINFALL AS A FRONTAL BOUNDARY SLOWLY CROSSES THE REGION. && .NEAR TERM /THROUGH TONIGHT/... AS OF 935 AM EDT...STRATUS CLOUDS CONTINUE TO EXPAND N AND W...ACROSS NW CT...THE MID HUDSON VALLEY REGION AND BERKSHIRES...AS WELL AS ACROSS THE SE CATSKILLS. AREAS OF LOW CLOUDS/FOG ACROSS THE WESTERN ADIRONDACKS...AND PORTIONS OF THE HELDERBERGS APPEARS TO BE DECREASING. HAVE MADE SOME CHANGES TO GRIDDED DATABASE BASED ON RECENT OBS...12Z UA SOUNDINGS...AND LATEST RAP/HRRR. FIRST WAS TO EXPAND THE SLIGHT CHC POPS A BIT FURTHER SOUTH INTO THE CENTRAL AND WESTERN MOHAWK VALLEY. THE LATEST RAP AND HRRR CONTINUE TO INDICATE POCKETS OF FAIRLY DECENT INSTABILITY DEVELOPING THIS AFTERNOON IN THIS REGION. IN ADDITION...THIS REGION WILL BE CLOSER TO A WEAK BOUNDARY...SEPARATING A SLIGHTLY COOLER MODIFIED MARINE AIR MASS TO THE E AND S...FROM A WARMER...MORE CONTINENTAL AIR MASS TO THE N AND W. ELSEWHERE...HAVE INCREASED CLOUDS COVERAGE AND LOWERED MAX TEMPS ACROSS WESTERN NEW ENGLAND...AND THE MID HUDSON VALLEY REGION. AS THE AFOREMENTIONED MODIFIED MARINE AIR CONTINUES TO WORK N AND W...MAX TEMPS MAY FAIL TO REACH 80 ACROSS THE BERKSHIRES/SOUTHERN GREENS...LITCHFIELD CO AND THE MID HUDSON VALLEY. ELSEWHERE...STILL EXPECT MAXES TO REACH 80-85 ACROSS THE UPPER HUDSON VALLEY FROM ALBANY NORTH...AND MID 80S ACROSS THE CENTRAL AND WESTERN MOHAWK VALLEY...WHERE EVEN SOME UPPER 80S ARE POSSIBLE. WILL NEED TO WATCH HOW FAR N AND W THE LOWER CLOUDS REACH...AS THIS MAY REQUIRE ADDITIONAL MODIFICATIONS TO MAX TEMPS/TOWARD LOWER VALUES/WITHIN THE CAPITAL REGION SHOULD MORE CLOUDS FORM. FOR TONIGHT...ANY CONVECTION SHOULD QUICKLY DISSIPATE THIS EVENING AS THE UPPER LEVEL RIDGE AXIS SLIDES FURTHER OFFSHORE. THIS WILL ALLOW THE UPSTREAM NORTHERN PLAINS TROUGH TO MIGRATE FURTHER EAST TOWARD THE CENTRAL GREAT LAKES REGION. ALONG WITH ITS APPROACH...MOISTURE ADVECTION FROM THE SOUTHEAST CONUS AND OHIO VALLEY WILL ADVANCE NORTHWARD. FORECAST SOUNDINGS SUPPORT AN ENTRAINMENT OF LOW LEVEL STRATUS FROM THE ATLANTIC YET RATHER DRY BETWEEN 850-500MB TO KEEP THE CHANCE OF PRECIP WEST OF THE REGION. EXPECTATIONS ARE FOR AN INCREASING CLOUD COVER AND A MILD OVERNIGHT WITH LOWS MAINLY INTO THE 60S. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... RAINFALL POTENTIAL INCREASES FROM WEST TO EAST AS THE LOW LEVEL JET INCREASES TO >40KTS TO ASSIST WITH RAPID MOISTURE TRANSPORT INTO THE CWFA. NCEP MODEL SUITE ARE IN EXCELLENT AGREEMENT WITH A PERIOD OF MODERATE RAINFALL TO MOVE ACROSS THE REGION ON TUESDAY. INSTABILITY PARAMETERS ARE NOT FAVORABLE FOR SEVERE WEATHER...HOWEVER...MID LEVEL VALUES PER THE SHOWALTERS STILL SUPPORT EMBEDDED DEEPER CONVECTION. PWATS ARE PROGGED TO CLIMB IN EXCESS OF 1.75" WITH UPSTREAM VALUES CLOSE TO 2.00". THESE VALUES ARE 2-3 STANDARD DEVIATIONS ABOVE NORMAL TO SUPPORT EMBEDDED PERIODS OF HEAVY RAINFALL. FAVORED UPSLOPE REGIONS OF THE CATSKILLS...NW CT INTO THE BERKS AND SOUTHERN VT MAY ENHANCE RAINFALL RATES. SEE THE HYDRO DISCUSSION FOR FURTHER DETAILS ON THE RAINFALL POTENTIAL IMPACTS. OTHERWISE...RATHER HIGH POPS EXPECTED DURING THE DAY WITH TEMPERATURES A BIT COOLER DUE TO THE MARINE INFLUENCE...CLOUDS AND PRECIP WITH HIGHS MAINLY IN THE MID 60S TO LOWER 70S. MODELS HAVE COME AROUND TO THE ECMWF OF THE PAST SEVERAL DAYS WITH A MORE PROGRESSIVE FROPA TUESDAY EVENING. SO WE WILL GRADUALLY LOWER POPS FROM WEST TO EAST ALONG WITH IMPROVEMENTS TO THE SKY COVER. HOWEVER...EAST OF THE HUDSON RIVER...THOSE CLOUDS WILL LIKELY LINGER LONGER UNTIL THE FRONT HAS CLEARED THE EASTERN SEABOARD. CONFIDENCE CONTINUES TO INCREASE THAT WEDNESDAY SHOULD TURN OUT TO BE A DRIER DAY. WHILE THE MID LEVELS OF THE ATMOSPHERE ARE EXPECTED TO REMAIN RATHER DRY...LOWER LEVELS WILL LIKELY REMAIN A BIT MORE MOIST DUE TO THE RAINFALL FROM TUESDAY EVENT AND LOW LEVEL NORTHEAST WIND TRAJECTORIES. SCT-BKN CLOUDS ARE EXPECTED FOR OUT ADJACENT WESTERN NEW ENGLAND COUNTIES WITH DOWNSLOPING COMPONENT INTO THE HUDSON RIVER VALLEY FOR AT LEAST A PTSUNNY DAY. AS FOR TEMPERATURES...A MODEL BLEND APPROACH WAS UTILIZED WHICH DOWNPLAYS THE COOLER VALUES WITHIN THE GFS MOS AND THE MUCH WARMER VALUES SEEN IN THE MET MOS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... THE MODELS HAVE STARTED TO COME INTO BETTER AGREEMENT REGARDING THE EXTENDED PERIOD...FOR THE PERIOD BEGINNING ON WEDNESDAY EVENING. AT THIS POINT...IT APPEARS THAT THE UPPER TROUGH RESPONSIBLE FOR BRINGING THE MID WEEK WET WEATHER WILL BE PROGRESSIVE AND CONTINUE TO MOVE EASTWARD ACROSS CANADA. ALTHOUGH THE SURFACE FRONTAL BOUNDARY WON/T MAKE A CLEAN SWEEP OUT TO SEA...IT LOOKS TO GENERALLY WASH OUT ACROSS NEW ENGLAND TO THE EAST OF OUR REGION. ALSO...WHILE IT STILL APPEARS THAT A SURFACE WAVE MAY DEVELOP ALONG THIS FRONT...THE LATEST 00 UTC ECMWF/GFS BOTH SHOW A WEAK LOW REMAINING OFF THE COAST...WITH HIGH PRESSURE BUILDING INTO OUR AREA FROM SOUTHERN CANADA. WHILE WE STILL MAY HAVE A LOW CHC/SLIGHT CHC FOR A RAIN SHOWER ACROSS THE REGION /ESP FOR EASTERN AREAS/ FOR WED NIGHT INTO THURSDAY DUE TO THE PROXIMITY OF THE SFC BOUNDARY...IT DOESN/T APPEAR TO BE A WASHOUT BY ANY STRETCH. SKIES LOOK TO RANGE FROM PARTLY CLOUDY IN WESTERN AREAS...TO MOSTLY CLOUDY FOR WESTERN NEW ENGLAND...DUE TO THE WEAK NE SURFACE FLOW IN PLACE. MIN TEMPS LOOK TO RANGE FROM THE MID 40S TO UPPER 50S FOR WED NIGHT...WITH MAX TEMPS GENERALLY IN THE 70S ON THURSDAY. STRONG UPPER RIDGING LOOKS TO BUILD INTO THE REGION FOR FRIDAY INTO THE WEEKEND AS A RIDGE OVER THE GREAT LAKES BENDS NORTHEASTWARD INTO OUR AREA. ALTHOUGH THE MODELS SHOW A CLOSED OFF 500 HPA LOW ACROSS THE WESTERN ATLANTIC...IT LOOKS TO STAY FAR ENOUGH EAST OF OUR AREA TO BE OF ANY CONCERN FOR US. WITH THE BUILDING RIDGE...AND WARMING TEMPS ALOFT...ENOUGH OF A CAP LOOKS TO BE IN PLACE TO PREVENT ANY CONVECTION FROM FIRING UP...SO HAVE GONE WITH A DRY FORECAST FOR FRIDAY ONWARD. VALLEY MAX TEMPS SHOULD BE GRADUALLY WARMER AND WARMER EACH DAY...WITH UPPER 70S TO NEAR 80 FOR FRIDAY...LOW 80S FOR SATURDAY...AND LOW TO MID 80S FOR SUNDAY. SKIES GENERALLY LOOK MOSTLY CLEAR TO PARTLY CLOUDY. AT THIS POINT...DEWPOINTS DON/T LOOK TOO MUGGY JUST YET...WITH TDS GENERALLY IN THE 50S F. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... HIGH PRESSURE WILL REMAIN ANCHORED OFF THE NEW ENGLAND COAST THROUGH TONIGHT. A WARM FRONT APPROACHING FROM THE SOUTHWEST WILL SPREAD CLOUDS...AND SHOWERS INTO THE REGION FOR TUESDAY AFTERNOON AND NIGHT. EXPECT VFR CONDITIONS THROUGH AT LEAST EARLY TONIGHT. THEN...AS A MOIST S/SE FLOW CONTINUES...SOME LOW CLOUDS ARE EXPECTED TO DEVELOP AND SPREAD NORTHWARD AFTER 06Z/TUE. THIS SHOULD LEAD TO MVFR CIGS DEVELOPING PRIOR TO 12Z/TUE...WITH A CHANCE FOR IFR CIGS AT KPSF...AND POSSIBLY KPOU. THERE IS A SLIGHT CHANCE THAT IFR CIGS MAY SPREAD EVEN FURTHER N...BUT AT THIS TIME...CONFIDENCE NOT QUITE HIGH ENOUGH TO INCLUDE AT KALB/KGFL. AREAS OF MVFR CIGS WILL LINGER THROUGH 14Z-15Z/TUE...WITH SOME POSSIBILITY OF IMPROVEMENT INTO THE LOW VFR RANGE THEREAFTER. HOWEVER...SHOWERS SHOULD DEVELOP ACROSS WESTERN AND CENTRAL NYS DURING THE MORNING...AND MAY IMPACT TAF SITES WEST OF THE HUDSON RIVER AFTER 16Z/TUE. SOUTH TO SOUTHEAST WINDS WILL REMAIN AT 8-12 KT THIS AFTERNOON...WITH SOME GUSTS OF 20-25 KT POSSIBLE...ESP AT KALB DUE TO FUNNELING EFFECTS UP THE HUDSON RIVER VALLEY. SOUTH TO SOUTHEAST WINDS WILL DIMINISH TO 5-10 KT TONIGHT...THEN INCREASE AGAIN TO 8-12 KT TUE MORNING...WITH SOME GUSTS OF 20-25 KT POSSIBLE. OUTLOOK... TUE-TUE NT...VFR/MVFR. CHC IFR. AFTERNOON SHRA/TSRA LIKELY. WED...VFR/MVFR. SHRA POSSIBLE EARLY. THU/SAT...VFR. SLIGHT CHC -SHRA. CHC LATE NIGHT/EARLY MORNING MVFR/IFR IN FOG/STRATUS. && .FIRE WEATHER... NO FIRE WEATHER CONCERNS ARE EXPECTED OVER THE NEXT SEVERAL DAYS. A SOUTH TO SOUTHEAST WIND WILL INCREASE TO AROUND 10 MPH TODAY WITH DRY WEATHER EXPECTED. AFTERNOON RH VALUES WILL DROP INTO THE 35-50 PERCENT...HIGHEST TO THE WEST OF ALBANY. MINIMUM RH VALUES TONIGHT REBOUND TO GREATER THAN 80 PERCENT. A WETTING RAIN IS EXPECTED ON TUESDAY TO FURTHER REDUCE FIRE WEATHER CONCERNS. && .HYDROLOGY... A MODERATE RAINFALL EVENT IS EXPECTED ON TUESDAY ACROSS THE HYDRO SERVICE AREA. LATEST MODEL GUIDANCE SUPPORTS A ROBUST MOISTURE TRANSPORT THAT SHOULD GENERATE AT LEAST BROKEN COVERAGE OF MODERATE TO HEAVY EMBEDDED CONVECTIVE RAINFALL RATES. EXPECTING THE RAINFALL TO BE OROGRAPHICALLY ENHANCED ACROSS PORTIONS OF THE CATSKILLS....BERKSHIRES AND SOUTHERN GREENS. PWAT ANOMALIES OF 2 TO 3 STD DEV ABOVE NORMAL...A >40 KT SOUTHERLY LOW LEVEL JET HELPING TO ENHANCE ISENTROPIC LIFT AND OROGRAPHICS SHOULD HELP ENHANCE RAINFALL RATES...AND THUS EXPECTING SOME LOCALLY HEAVIER TOTALS FOR THE EVENT AT OR ABOVE 2 INCHES. THIS SHOULD PRODUCE RISES ON AREA RIVERS AND STREAMS...BUT NO FLOODING IS EXPECTED ON THE STREAMS AND RIVERS. LATEST RUN OF THE MMEFS GUIDANCE ALSO SUPPORT THIS IDEA WITH NO POINTS EXPECTED TO CLIMB ABOVE FLOOD STAGE. 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...KL/BGM NEAR TERM...KL/BGM SHORT TERM...BGM LONG TERM...FRUGIS AVIATION...KL FIRE WEATHER...BGM HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
511 PM CDT MON JUN 11 2012 .DISCUSSION... 320 PM CDT THE FORECAST CONCERNS ARE VERY MINIMAL THROUGH THE REST OF THE WEEK WITH A CONTINUED DRY PATTERN. WILL BE MONITORING FOR A FEW STORMS LATE THIS AFTERNOON INTO EARLY EVENING...OTHERWISE THAT MAY WILL LIKELY BE ALL THAT IS ON THE SCOPE FOR QUITE A WHILE. ISOLATED SHOWERS WITH A FEW STORMS REDEVELOPING OVER COOK COUNTY AND SOUTH ALONG THE IL/IN STATE LINE...WHICH IS ALONG AND JUST AHEAD OF A WEAK CONVERGENT AXIS AND APPARENT SHORT WAVE SEEN ON SATELLITE. MID 80S TEMPERATURES AND UPPER 60S DEW POINTS ALONG AND AHEAD OF THIS CORRIDOR HAS BUILT SURFACE BASED CAPE TO AROUND OR SLIGHTLY OVER 2000 J/KG. THIS CONVECTION SHOULD LAST LONGER THAN THE PREVIOUS ACTIVITY NEAR NOON BEING CLOSER TO THE SHORT WAVE CENTER AND HAVING MORE INSTABILITY TO WORK WITH. UPPER LEVEL WIND SHEAR LOOKS TO BE AROUND A MEAGER 20 KT PER PROFILER ANALYSIS. THE BEHAVIOR OF THE STORM CORES IS LIKELY TO BE SOMEWHAT PULSY WITH INSTABILITY IN THE DRIVERS SEAT...AND WITH LIMITED ATTENDANT SHEAR IT LEAVES ONLY A VERY SMALL CHANCE FOR ANY TYPE OF SEVERE ACTIVITY. THE SYSTEM UPPER TROUGH CENTER IS LOCATED ALONG THE MN/WESTERN QUEBEC BORDER WITH PRIMARY HEIGHT FALLS...THE UPPER JET AXIS...AND ASSOCIATED DEEPER ASCENT MOVING EAST FROM THERE. THIS FORCING HAS AIDED SOME SHOWER DEVELOPMENT ALONG THE SURFACE COLD FRONT IN WESTERN WI. THE COOL FRONT EXTENDS SOUTH FROM THERE WHERE IT WILL MOVE INTO NW IL BY 4 PM AND EAST THROUGH THE FORECAST AREA THIS EVE. THE WIND SHIFT IS GRADUAL FROM WEST SOUTHWEST TO WEST NORTHWEST ALONG THE BOUNDARY...AND IT IS ACTUALLY AHEAD OF THE STRONGEST MOISTURE CONVERGENCE. SO OVERALL CONVERGENCE IS LIMITED AND FEEL THAT WILL BE THE CASE WITH ANY CONVECTION THAT WERE TO TRIGGER ALONG IT...WHICH IS NOW APPEARING DOUBTFUL IN OUR AREA. THE HRRR AND OTHER EXPLICIT CONVECTIVE MODELS AGREE IN THIS LIMITED COVERAGE. THE COOL FRONT WILL MOVE THROUGH THE AREA THIS EVENING AND IT LOOKS LIKE THE BOUNDARY LAYER WILL STAY MIXED AS IT DOES SUCH...WITH SOME GUSTS UP TO 20 MPH AS THE PRESSURE RISE AXIS MOVES THROUGH. SUNNY AND DRY WEATHER WILL THEN ONCE AGAIN BE THE STORY AS CANADIAN HIGH PRESSURE MOVES OVERHEAD TUESDAY NIGHT INTO WEDNESDAY. THE REALLY ONLY WEATHER OF INTEREST FROM DAY TO DAY WILL BE HOW LOW DEW POINTS WILL DROP DURING THE AFTERNOON MIXING...AND TO WHAT DEGREE OF COOLING WILL THERE BE FROM THE LAKE. NORTHWEST WINDS WILL BEGIN TO DECREASE TUESDAY AFTERNOON...POTENTIALLY ALLOWING FOR A SLIGHT LAKE BREEZE INTO IL...BUT LIKELY INTO IN. THIS MAY NOT DEVELOP UNTIL LATE AFTERNOON THOUGH...SO WIDESPREAD HIGHS IN THE MID TO UPPER 70S ARE EXPECTED. UPSTREAM DEW POINTS TODAY HAVE BEEN IN THE LOWER TO MID 40S ACROSS EASTERN SD. THIS AND POSSIBLY EVEN LOWER SHOULD BE REALIZED DURING TUESDAY AFTERNOON WITH PROJECTED MIXING TO 850 MB. THE AFTERNOON HUMIDITY WILL REMAIN LOW...UNDER 25 PERCENT...ON WEDNESDAY AFTERNOON WITH THE SYNOPTIC FLOW TURNING NORTHEAST AND THEN EAST. INFLUENCE FROM THE LAKE WILL LIKELY CONTINUE TO MOVE INTO CHICAGO DURING THE AFTERNOON ALL THE WAY THROUGH SATURDAY. THE UPPER LEVEL HEIGHTS AND LOW-LEVEL THERMAL RIDGE BUILD MORE INTO THE AREA THURSDAY NIGHT INTO SATURDAY. THE EC HAS SHOWN IN THE UPPER LEVEL SW FLOW THAT SHORT WAVE ENERGY IS POSSIBLE WITHIN THIS AND MAY DAMPEN THE RIDGE SLIGHTLY SATURDAY NIGHT INTO SUNDAY...AND HAVE A SMALL CHANCE FOR POPS DURING PART OF THAT TIME. OTHERWISE...HAVE COLLABORATED GOING DRIER THAN POPS AND DEW POINTS FROM GUIDANCE BLENDS IN THE EXTENDED PER PERSISTENCE AND AN OVERALL STAGNANT PATTERN. MTF && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 22Z... * DECREASING TSRA/SHRA THREAT. * GUSTY WSW WINDS SHIFTING TO NW WITH COLD FROPA AROUND 02-03Z. RATZER //DISCUSSION...UPDATED 22Z... ISOLATED SHRA/TSRA WHICH HAD FORMED SOUTHEAST OF ORD/MDW THIS AFTERNOON HAVE WEAKENED AND MOVED OUT OVER SOUTHERN LAKE MICHIGAN. PRE-FRONTAL TROUGH HAS MOVED THROUGH MOST OF TERMINAL AREA...WITH WINDS SHIFTING WEST-SOUTHWEST BEHIND IT. THIS IS EXPECTED TO LIMIT LOW LEVEL CONVERGENCE NECESSARY FOR ADDITIONAL TSRA/SHRA DEVELOPMENT AHEAD OF COLD FRONT AND UPPER TROUGH WHICH WILL MOVE ACROSS THE AREA LATER THIS EVENING. THUS WHILE ISOLATED SHRA/TSRA CANT COMPLETELY BE RULED OUT OF THE REALM OF POSSIBILITY FOR THE NEXT 3-4 HOURS...PROBABILITY OF THIS OCCURRING IS VERY LOW AND WILL NOT CARRY ANY MENTION IN TAFS. AS INDICATED...WINDS SHIFTING MORE WEST-SOUTHWEST WITH SOME GUSTS AROUND 20 KTS BETWEEN PRE- FRONTAL TROUGH AND APPROACHING COLD FRONT...THEN WILL SHIFT WEST- NORTHWEST AFTER COLD FROPA. TIMING OF FRONT IN THE 02-03Z TIME FRAME STILL LOOKS REASONABLE. LATEST GUIDANCE INDICATES LOW LEVEL MIXING MAY SUPPORT GUSTS FOR A FEW HOURS POST FROPA. RATZER PREVIOUS DISCUSSION FROM 18Z... A COLD FRONT LIES ACROSS NORTHWEST WISCONSIN SOUTH INTO CENTRAL IOWA THIS AFTERNOON. ONGOING THUNDERSTORMS CONTINUE ACROSS PORTIONS SOUTHERN MISSOURI INTO CENTRAL ILLINOIS PROVIDING A CANOPY OF CLOUD COVER ACROSS MUCH OF NORTHERN ILLINOIS THIS AFTERNOON. THERE IS SOME CLEARING ACROSS PORTIONS OF EAST CENTRAL ILLINOIS AND NORTHWEST INDIANA WHERE AN AXIS OF MODEST INSTABILITY HAS BEGUN TO DEVELOP. AN UPPER LEVEL DISTURBANCE MOVING ACROSS IOWA EARLY THIS AFTERNOON WILL PUSH EAST ACROSS NORTHERN ILLINOIS WITH THE POTENTIAL FOR ADDITIONAL THUNDERSTORM DEVELOPMENT ACROSS THIS INSTABILITY AXIS MID AFTERNOON. IT APPEARS THE THREAT SHOULD STAY SOUTHEAST/EAST OF ORD/MDW WITH SOME POTENTIAL FOR GYY TO BE IMPACTED OR AT LEAST TO SEE ACTIVITY IN THE VICINITY OF THE TERMINAL. MOVED UP VCTS AT GYY TO START OF TAF GIVEN ACTIVITY CURRENTLY IN THE AREA JUST NORTHWEST OF THE TERMINAL AT 18Z. LATE THIS EVENING...THE COLD FRONT IS EXPECTED TO MOVE ACROSS THE AREA WITH WINDS BECOMING NORTHWEST. THERE MAY BE ADDITIONAL THUNDERSTORMS THAT DEVELOP ALONG THE FRONT...BUT GIVEN THE WEAK CONVERGENCE ALONG THE FRONT AND LOSS OF DIURNAL HEATING...EXPECT COVERAGE TO BE ISOLATED TO WIDELY SCATTERED WITH LOW THREAT OF BEING ON STATION. ON TUESDAY...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE NORTHWEST. WILL HAVE TO MONITOR THE POSSIBILITY OF A LAKE BREEZE TURNING WINDS NORTHEAST IN THE CHICAGO AREA LATE IN THE AFTERNOON. BMD/RC //ORD AND MDW CONFIDENCE...UPDATED 22Z... * MEDIUM-HIGH CONFIDENCE IN WIND TRENDS THROUGH LATE EVENING. * MEDIUM-HIGH CONFIDENCE IN NO ADDITIONAL TSRA/SHRA PRIOR TO COLD FROPA THIS EVENING. RATZER //OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z... TUESDAY NIGHT THROUGH SATURDAY...VFR. SUNDAY...VFR. SLIGHT CHC SHRA/TSRA. BEACHLER && .MARINE... 231 PM CDT A LARGE LOW HAS MOVED INTO HUDSON BAY...WHILE HIGH PRESSURE SITS OFF THE NEW ENGLAND COAST. THE UPPER LEVEL PRESSURE GRADIENT HAS RELAXED...RESULTING IN SOUTH TO SOUTHWEST WINDS 15-25 KT ACROSS THE LAKE THIS AFTERNOON. STRONGEST WINDS AROUND 25 KT WILL CONTINUE TO BE OVER THE NORTHERN HALF OF THE LAKE WHICH IS CLOSER TO THE LOW AND ITS TIGHT PRESSURE GRADIENT. THE LOWS COLD FRONT WILL SWEEP ACROSS THE LAKE TONIGHT. WINDS WILL TURN OUT OF THE WEST AT 15 TO 25 KT ACROSS THE LAKE BEHIND THE FRONT. HIGH PRESSURE MOVES IN BEHIND THE FRONT TUESDAY NIGHT...WITH WINDS DIMINISHING AND BECOMING NORTHERLY FOR A ON TUESDAY. THE LIGHT WINDS WILL CONTINUE TO VEER TO EASTERLY AS THE HIGH MOVES OVER THE LAKE WEDNESDAY. WINDS TURN SOUTHEASTERLY AS THE HIGH MAKES ITS WAY OVER NORTHERN QUEBEC ON THURSDAY. ALTHOUGH THE CENTER OF THE HIGH MOVES OFF TO THE NORTHEAST...A LARGE RIDGE WILL REMAIN OVER THE EASTERN THIRD OF THE US THROUGH THE REMAINING PART OF THE FORECAST PERIOD. THIS PATTERN WILL RESULT IN LIGHT WINDS VARYING BETWEEN EAST AND SOUTH. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
320 PM CDT MON JUN 11 2012 .DISCUSSION... 320 PM CDT THE FORECAST CONCERNS ARE VERY MINIMAL THROUGH THE REST OF THE WEEK WITH A CONTINUED DRY PATTERN. WILL BE MONITORING FOR A FEW STORMS LATE THIS AFTERNOON INTO EARLY EVENING...OTHERWISE THAT MAY WILL LIKELY BE ALL THAT IS ON THE SCOPE FOR QUITE A WHILE. ISOLATED SHOWERS WITH A FEW STORMS REDEVELOPING OVER COOK COUNTY AND SOUTH ALONG THE IL/IN STATE LINE...WHICH IS ALONG AND JUST AHEAD OF A WEAK CONVERGENT AXIS AND APPARENT SHORT WAVE SEEN ON SATELLITE. MID 80S TEMPERATURES AND UPPER 60S DEW POINTS ALONG AND AHEAD OF THIS CORRIDOR HAS BUILT SURFACE BASED CAPE TO AROUND OR SLIGHTLY OVER 2000 J/KG. THIS CONVECTION SHOULD LAST LONGER THAN THE PREVIOUS ACTIVITY NEAR NOON BEING CLOSER TO THE SHORT WAVE CENTER AND HAVING MORE INSTABILITY TO WORK WITH. UPPER LEVEL WIND SHEAR LOOKS TO BE AROUND A MEAGER 20 KT PER PROFILER ANALYSIS. THE BEHAVIOR OF THE STORM CORES IS LIKELY TO BE SOMEWHAT PULSY WITH INSTABILITY IN THE DRIVERS SEAT...AND WITH LIMITED ATTENDANT SHEAR IT LEAVES ONLY A VERY SMALL CHANCE FOR ANY TYPE OF SEVERE ACTIVITY. THE SYSTEM UPPER TROUGH CENTER IS LOCATED ALONG THE MN/WESTERN QUEBEC BORDER WITH PRIMARY HEIGHT FALLS...THE UPPER JET AXIS...AND ASSOCIATED DEEPER ASCENT MOVING EAST FROM THERE. THIS FORCING HAS AIDED SOME SHOWER DEVELOPMENT ALONG THE SURFACE COLD FRONT IN WESTERN WI. THE COOL FRONT EXTENDS SOUTH FROM THERE WHERE IT WILL MOVE INTO NW IL BY 4 PM AND EAST THROUGH THE FORECAST AREA THIS EVE. THE WIND SHIFT IS GRADUAL FROM WEST SOUTHWEST TO WEST NORTHWEST ALONG THE BOUNDARY...AND IT IS ACTUALLY AHEAD OF THE STRONGEST MOISTURE CONVERGENCE. SO OVERALL CONVERGENCE IS LIMITED AND FEEL THAT WILL BE THE CASE WITH ANY CONVECTION THAT WERE TO TRIGGER ALONG IT...WHICH IS NOW APPEARING DOUBTFUL IN OUR AREA. THE HRRR AND OTHER EXPLICIT CONVECTIVE MODELS AGREE IN THIS LIMITED COVERAGE. THE COOL FRONT WILL MOVE THROUGH THE AREA THIS EVENING AND IT LOOKS LIKE THE BOUNDARY LAYER WILL STAY MIXED AS IT DOES SUCH...WITH SOME GUSTS UP TO 20 MPH AS THE PRESSURE RISE AXIS MOVES THROUGH. SUNNY AND DRY WEATHER WILL THEN ONCE AGAIN BE THE STORY AS CANADIAN HIGH PRESSURE MOVES OVERHEAD TUESDAY NIGHT INTO WEDNESDAY. THE REALLY ONLY WEATHER OF INTEREST FROM DAY TO DAY WILL BE HOW LOW DEW POINTS WILL DROP DURING THE AFTERNOON MIXING...AND TO WHAT DEGREE OF COOLING WILL THERE BE FROM THE LAKE. NORTHWEST WINDS WILL BEGIN TO DECREASE TUESDAY AFTERNOON...POTENTIALLY ALLOWING FOR A SLIGHT LAKE BREEZE INTO IL...BUT LIKELY INTO IN. THIS MAY NOT DEVELOP UNTIL LATE AFTERNOON THOUGH...SO WIDESPREAD HIGHS IN THE MID TO UPPER 70S ARE EXPECTED. UPSTREAM DEW POINTS TODAY HAVE BEEN IN THE LOWER TO MID 40S ACROSS EASTERN SD. THIS AND POSSIBLY EVEN LOWER SHOULD BE REALIZED DURING TUESDAY AFTERNOON WITH PROJECTED MIXING TO 850 MB. THE AFTERNOON HUMIDITY WILL REMAIN LOW...UNDER 25 PERCENT...ON WEDNESDAY AFTERNOON WITH THE SYNOPTIC FLOW TURNING NORTHEAST AND THEN EAST. INFLUENCE FROM THE LAKE WILL LIKELY CONTINUE TO MOVE INTO CHICAGO DURING THE AFTERNOON ALL THE WAY THROUGH SATURDAY. THE UPPER LEVEL HEIGHTS AND LOW-LEVEL THERMAL RIDGE BUILD MORE INTO THE AREA THURSDAY NIGHT INTO SATURDAY. THE EC HAS SHOWN IN THE UPPER LEVEL SW FLOW THAT SHORT WAVE ENERGY IS POSSIBLE WITHIN THIS AND MAY DAMPEN THE RIDGE SLIGHTLY SATURDAY NIGHT INTO SUNDAY...AND HAVE A SMALL CHANCE FOR POPS DURING PART OF THAT TIME. OTHERWISE...HAVE COLLABORATED GOING DRIER THAN POPS AND DEW POINTS FROM GUIDANCE BLENDS IN THE EXTENDED PER PERSISTENCE AND AN OVERALL STAGNANT PATTERN. MTF && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * WINDS SHIFTING FROM SW THIS AFTERNOON TO NW THIS EVENING...POTENTIAL FOR GUSTINESS TO CONTINUE OVERNIGHT. * COUPLE WINDOWS OF POTENTIAL FOR ADDITIONAL THUNDERSTORM DEVELOPMENT THIS AFTERNOON AND AGAIN THIS EVENING. RC //DISCUSSION...UPDATED 20Z... STILL DO NOT THINK TSRA WILL DIRECTLY IMPACT ORD/MDW THE NEXT FEW HOURS AND PROBABILITY OF REDEVELOPMENT AHEAD OF FRONT THIS EVENING IS LOW. VCTS NEAR GYY SHOULD REMAIN SOUTHEAST OF GYY. WILL MONITOR POTENTIAL FOR POP-UP DEVELOPMENT THE NEXT FEW HOURS. OTHER CHANGE IN 20Z AMD WAS TO MOVE UP TIMING OF WIND SHIFT TO NORTHWEST BY 1 HOUR EARLIER AT TAF SITES. THIS MAY NEED TO BE MOVED UP A BIT MORE. POTENTIAL FOR NW WIND GUSTS AFTER FRONTAL PASSAGE EXISTS...BUT NOT ENOUGH CONFIDENCE TO INCLUDE IN TAF. RC ...FROM 18Z... A COLD FRONT LIES ACROSS NORTHWEST WISCONSIN SOUTH INTO CENTRAL IOWA THIS AFTERNOON. ONGOING THUNDERSTORMS CONTINUE ACROSS PORTIONS SOUTHERN MISSOURI INTO CENTRAL ILLINOIS PROVIDING A CANOPY OF CLOUD COVER ACROSS MUCH OF NORTHERN ILLINOIS THIS AFTERNOON. THERE IS SOME CLEARING ACROSS PORTIONS OF EAST CENTRAL ILLINOIS AND NORTHWEST INDIANA WHERE AN AXIS OF MODEST INSTABILITY HAS BEGUN TO DEVELOP. AN UPPER LEVEL DISTURBANCE MOVING ACROSS IOWA EARLY THIS AFTERNOON WILL PUSH EAST ACROSS NORTHERN ILLINOIS WITH THE POTENTIAL FOR ADDITIONAL THUNDERSTORM DEVELOPMENT ACROSS THIS INSTABILITY AXIS MID AFTERNOON. IT APPEARS THE THREAT SHOULD STAY SOUTHEAST/EAST OF ORD/MDW WITH SOME POTENTIAL FOR GYY TO BE IMPACTED OR AT LEAST TO SEE ACTIVITY IN THE VICINITY OF THE TERMINAL. MOVED UP VCTS AT GYY TO START OF TAF GIVEN ACTIVITY CURRENTLY IN THE AREA JUST NORTHWEST OF THE TERMINAL AT 18Z. LATE THIS EVENING...THE COLD FRONT IS EXPECTED TO MOVE ACROSS THE AREA WITH WINDS BECOMING NORTHWEST. THERE MAY BE ADDITIONAL THUNDERSTORMS THAT DEVELOP ALONG THE FRONT...BUT GIVEN THE WEAK CONVERGENCE ALONG THE FRONT AND LOSS OF DIURNAL HEATING...EXPECT COVERAGE TO BE ISOLATED TO WIDELY SCATTERED WITH LOW THREAT OF BEING ON STATION. ON TUESDAY...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE NORTHWEST. WILL HAVE TO MONITOR THE POSSIBILITY OF A LAKE BREEZE TURNING WINDS NORTHEAST IN THE CHICAGO AREA LATE IN THE AFTERNOON. BMD/RC //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM TO HIGH CONFIDENCE IN WIND DIRECTION...LOW CONFIDENCE IN WIND GUST MAGNITUDE...PARTICULARLY THIS EVENING BEHIND THE FRONT. * MEDIUM CONFIDENCE IN TSRA SE OF THE TERMINALS THIS AFTERNOON...LOW CONFIDENCE IT WILL IMPACT ORD/MDW. * LOW CONFIDENCE IN TSRA ALONG THE FRONT THIS EVENING. RC //OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z... TUESDAY NIGHT THROUGH SATURDAY...VFR. SUNDAY...VFR. SLIGHT CHC SHRA/TSRA. BEACHLER && .MARINE... 231 PM CDT A LARGE LOW HAS MOVED INTO HUDSON BAY...WHILE HIGH PRESSURE SITS OFF THE NEW ENGLAND COAST. THE UPPER LEVEL PRESSURE GRADIENT HAS RELAXED...RESULTING IN SOUTH TO SOUTHWEST WINDS 15-25 KT ACROSS THE LAKE THIS AFTERNOON. STRONGEST WINDS AROUND 25 KT WILL CONTINUE TO BE OVER THE NORTHERN HALF OF THE LAKE WHICH IS CLOSER TO THE LOW AND ITS TIGHT PRESSURE GRADIENT. THE LOWS COLD FRONT WILL SWEEP ACROSS THE LAKE TONIGHT. WINDS WILL TURN OUT OF THE WEST AT 15 TO 25 KT ACROSS THE LAKE BEHIND THE FRONT. HIGH PRESSURE MOVES IN BEHIND THE FRONT TUESDAY NIGHT...WITH WINDS DIMINISHING AND BECOMING NORTHERLY FOR A ON TUESDAY. THE LIGHT WINDS WILL CONTINUE TO VEER TO EASTERLY AS THE HIGH MOVES OVER THE LAKE WEDNESDAY. WINDS TURN SOUTHEASTERLY AS THE HIGH MAKES ITS WAY OVER NORTHERN QUEBEC ON THURSDAY. ALTHOUGH THE CENTER OF THE HIGH MOVES OFF TO THE NORTHEAST...A LARGE RIDGE WILL REMAIN OVER THE EASTERN THIRD OF THE US THROUGH THE REMAINING PART OF THE FORECAST PERIOD. THIS PATTERN WILL RESULT IN LIGHT WINDS VARYING BETWEEN EAST AND SOUTH. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
258 PM CDT MON JUN 11 2012 .DISCUSSION... ISSUED 258 PM CDT MON JUN 11 2012 SHORT TERM...TONIGHT THROUGH THURSDAY MAIN QUESTION IN THE IMMEDIATE SHORT-TERM IS WHETHER OR NOT ANY CONVECTION WILL RE-DEVELOP ALONG AN ADVANCING COLD FRONT THIS EVENING. 2 PM SURFACE ANALYSIS SHOWS FRONT ACROSS EASTERN IOWA...HOWEVER AIRMASS AHEAD OF IT IS STILL QUITE STABLE DUE TO MORNING CONVECTION THAT DECAYED ACROSS WEST-CENTRAL ILLINOIS. LATEST MESO-ANALYSIS FROM SPC IS INDICATING SOME DESTABILIZATION ALONG THE BOUNDARY...WITH SURFACE-BASED CAPES BACK UP TO AROUND 1500 TO 2000J/KG. 19Z VISIBLE SATELLITE IMAGERY IS SHOWING A NARROW RIBBON OF CU DEVELOPING IN THE INSTABILITY AXIS...HOWEVER NO SHOWERS/STORMS HAVE FIRED YET. 12Z MODELS ARE LARGELY USELESS...AS NONE OF THEM ADEQUATELY PREDICTED THE STORMS THAT ROLLED ACROSS SOUTH-CENTRAL AND SOUTHEAST ILLINOIS THIS AFTERNOON ALONG THE LEADING EDGE OF AN OLD OUTFLOW BOUNDARY. EVEN SOME OF THE HIGHER-RES MODELS SUCH AS THE 4KM WRF FAILED TO CAPTURE THIS CONVECTION...SO THEIR SOLUTIONS FOR LATE THIS AFTERNOON AND EVENING ARE SUSPECT. THE 17Z HRRR SEEMS TO HAVE THE BEST HANDLE ON REALITY...SHOWING THE CURRENT CONVECTION ACROSS THE FAR E/SE KILX CWA EXITING THE AREA OVER THE NEXT 2 TO 3 HOURS...FOLLOWED BY LARGELY DRY CONDITIONS THIS EVENING. THE HRRR DOES TRY TO DEVELOP SOME ISOLATED CONVECTION ALONG THE COLD FRONT AS IT PUSHES INTO THE ILLINOIS RIVER VALLEY AROUND 00Z...BUT THIS RAPIDLY DISSIPATES AS DAYTIME INSTABILITY IS LOST AFTER SUNSET. SINCE THE FRONT IS STILL OFF TO THE WEST...THINK THIS SOLUTION SEEMS REASONABLE...SO WILL MENTION ISOLATED THUNDER ACROSS THE BOARD DURING THE EARLY EVENING. AFTER THAT...SKIES WILL CLEAR FROM WEST TO EAST ACROSS THE AREA AS THE FRONT PUSHES INTO INDIANA AFTER MIDNIGHT. HIGH PRESSURE WILL BUILD INTO THE GREAT LAKES FOR THE MIDDLE OF THE WEEK...PROVIDING COOLER AND LESS HUMID CONDITIONS FOR TUESDAY THROUGH THURSDAY. COOLEST MORNING WILL BE WEDNESDAY MORNING...WHEN TEMPS FALL INTO THE LOWER 50S. AFTERNOON HIGHS ON WEDNESDAY WILL BE NEAR OR SLIGHTLY BELOW NORMAL IN THE UPPER 70S/LOWER 80S. LONG TERM...FRIDAY THROUGH MONDAY WARMER AND MORE HUMID WEATHER WILL RETURN FOR THE EXTENDED...AS UPPER TROUGH DIGS ACROSS THE WESTERN CONUS AND RIDGING DEVELOPS ACROSS THE EAST. MODELS CONTINUE TO DISAGREE ON THE EXACT DEGREE OF AMPLIFICATION WITHIN THE FLOW...WITH THE 12Z 11 JUN GFS FEATURING A STRONG RIDGE AND RESULTING DRY CONDITIONS RIGHT THROUGH EARLY NEXT WEEK. MEANWHILE...THE LATEST ECMWF CONTINUES TO BE WEAKER WITH THE UPPER RIDGE AND BRINGS A FRONTAL BOUNDARY INTO THE AREA SUNDAY INTO MONDAY. GIVEN CURRENT MODEL DISCREPANCIES AND THE FACT THAT PARTS OF CENTRAL ILLINOIS ARE IN A MODERATE DROUGHT...WILL MAINTAIN HOT AND DRY CONDITIONS THROUGH MONDAY. BARNES && .AVIATION... ISSUED 1255 PM CDT MON JUN 11 2012 LINE OF STRONG THUNDERSTORMS ALONG I-57 ON LEADING EDGE OF MCS AT CMI JUST GOT A NW WIND GUST OF 35 KTS WITH HEAVY RAINS TO REDUCE VSBY TO 1/2-1 MILE DURING THE NEXT HOUR OR SO AS LINE MOVES STEADILY EASTWARD. MVFR CEILINGS LIKELY AS WELL AT CMI. NO REPORTS OF HAIL YET AND THINK BETTER HAIL THREAT WILL BE SOUTH OF CMI. HAVE TS WITH MVFR CEILINGS AND VSBY AT DEC NEXT HOUR WHILE CONVECTION APPEARS TO BE EAST OF I-55/REST OF CENTRAL IL TAF SITES THIS AFTERNOON. COULD STILL BE ISOLATED CONVECTION THIS AFTERNOON AS COLD FRONT IN SE IA INTO CENTRAL MO TRACKS SE INTO SE IL EARLY THIS EVENING. SKIES TO CLEAR LATER THIS EVENING AND CONTINUE THROUGH TUE AS 1026 MB HIGH PRESSURE OVER THE NORTHERN ROCKIES SETTLES INTO THE MIDWEST BY 18Z/TUE. SSW WINDS 10-15 KTS WITH POSSIBLE WIND GUSTS NEAR 20 KTS TO TURN NW BEHIND THE FRONT AND DIMINISH TO 5-10 KTS THEN BE NW 10-15 KTS TUESDAY WITH GUSTS TO 20 KTS BY MIDDAY TUE. HUETTL && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1214 PM CDT MON JUN 11 2012 ...UPDATE TO AVIATION... .DISCUSSION... STRONG MOISTURE CONVERGENCE CONTINUES IN FAR NORTHEAST KANSAS BEHIND SURFACE FRONT...WHICH LIES FROM ROUGHLY FROM KDSM TO KTOP TO KWLD AT 08Z. GUSTY NORTHEAST WINDS WERE REPORTED AT KMHK AT 08Z WITH OUTFLOW BOUNDARY SHOWING NEAR THE KTWX RADAR. MUCH DRIER AIR NOT FAR BEHIND WITH SURFACE DEWPOINTS IN THE UPPER 40S IN NORTH CENTRAL KANSAS AND LOWER 30S IN NORTHWEST KANSAS. WEAK MID LEVEL RETURNS SHOWING UP ON WESTERN KANSAS RADARS BUT LITTLE NEARING THE SURFACE IN MID LEVEL FRONTOGENESIS. 0Z 850MB TEMPS WERE VERY CLOSE TO 20C THROUGHOUT THE SURROUNDING STATES...THOUGH TEMPS BELOW 10C WERE SAMPLED IN MONTANA. WILL GO ALONG WITH HRRR AND RUC WITH CONVECTION SLOWLY PUSHING SOUTHEAST OUT OF THE AREA THIS MORNING AS THE MODIFIED CONTINENTAL AIRMASS MOVES IN. WESTERN MID LEVEL RETURNS SHOULD ENCOUNTER THIS DRIER AIR AND STILL STRUGGLE TO REACH THE GROUND. COLD AIR ADVECTION TAKES ITS TIME GETTING HERE HOWEVER...WITH SOMEWHAT INCREASED LEVELS COMING LATE IN THE DAY. WITH SOME EARLY DAY HIGH CLOUD AS WELL...THIS MAY KEEP NORTHERN AREAS IN THE MID 80S...WITH SOME UPPER 80S ALONG I-70 WHERE EARLY DAY DEBRIS IS MORE REMOVED AND BETTER CALL WILL HOLD OFF LONGER. TONIGHT INTO TUESDAY PERIODS LOOK RATHER QUIET WITH SURFACE HIGH PASSING ACROSS NEBRASKA AND IOWA AND 700-850MB RIDGING OVER EASTERN KANSAS. MAY SEE SOME HIGH CLOUD MOVE OUT OF THE ROCKIES TUESDAY WITH HIGHS A LITTLE COOLER THAN TODAY. MODELS HAVE BEEN FAIRLY CONSISTENT WITH A WEAK UPPER WAVE MOVING THROUGH LATE TUESDAY NIGHT INTO WEDNESDAY EVENING. SOUTHERLY LOW/MID LEVEL FLOW WILL SLOWLY INCREASE RESULTING IN WEAK ISENTROPIC LIFT WHILE PRECIPITABLE WATER VALUES RISE TO AROUND 1.3 INCHES BY LATE WEDNESDAY. COMBINED FORCING AND DEEPER MOISTURE MAY BE ENOUGH FOR SOME CONVECTION...THOUGH COVERAGE IS MUCH IN QUESTION AT THIS POINT. WILL KEEP POPS ON THE LOW SIDE WEDNESDAY AND WEDNESDAY NIGHT...KEEPING TUESDAY NIGHT DRY AT THIS POINT. WEAK MID LEVEL LAPSE RATES SHOULD KEEP STRONG INSTABILITY IN CHECK. WARM AND HUMID CONDITIONS TO RULE MUCH OF THE EXTENDED PERIODS WITH LITTLE CHANGE IN AIRMASS FROM THE AFOREMENTIONED SITUATION. FAIRLY GOOD MODEL AGREEMENT WITH WEAK UPPER RIDGE FROM THE SOUTHERN PLAINS INTO THE GREAT LAKES THROUGH AT LEAST SATURDAY AND STRONG FORCING MECHANISM APPEAR LACKING...BUT ALSO LACKING IS STRONG CAPPING. SMALL PRECIPITATION CHANCES...NEAR CLIMATOLOGICAL VALUES FOR MID JUNE... WILL BE KEPT FOR THE BULK OF THESE PERIODS WITH TEMPS SOMEWHAT ABOVE NORMAL. 65 && .AVIATION... VFR CONDITIONS ARE FORECAST THROUGH THE TAF PERIOD. NORTH WINDS WILL PERSIST WITH GUSTS APPROACHING 20 KTS TODAY...BUT WILL TAPER OFF TO LIGHT NNE OR NEAR CALM AFTER SUNSET THROUGH THE REMAINDER OF THE TAF. BARJENBRUCH && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
647 PM EDT MON JUN 11 2012 .SYNOPSIS... A COLD FRONT WILL BRING SHOWERS AND A CHANCE FOR THUNDERSTORMS TONIGHT INTO TUESDAY. HIGH PRESSURE IS THEN EXPECTED TO BRING DRY WEATHER THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TUESDAY/... RADAR LOOP SHOWS WIDELY SCATTERED SHOWERS DEVELOPING OVER RLX THE PAST FEW HOURS AND SLOWLY MOVING NORTHWARD. LATEST HRRR AND RAP MODELS SUGGEST MORE SCATTERED SHOWERS TO DEVELOP TONIGHT BEFORE TAPERING OFF IN THE MID MORNING HOURS. THUS HAVE INCREASED POPS SLIGHTLY TO INCLUDE MORE CATEGORICAL AREAS TONIGHT. KEPT ONLY SLIGHT CHANCE OF THUNDER TONIGHT AS INSTABILITY REMAINS MINIMAL AND CIN BEGINNING TO FORM OVER THE REGION. COLD FRONT WILL THEN PASS ACROSS THE REGION TUESDAY AFTERNOON. SPC HAS CONTINUED TO INCLUDE THE AREA AS A `SEE TEXT` MENTION IN THE DAY 2 CONVECTIVE OUTLOOK. APPEARS THAT MODERATE INSTABILITY WILL BE PRESENT...BUT ONLY LOW VALUES OF WIND SHEAR WILL BE PRESENT. AT THIS POINT...APPEARS AS IF THERE WILL ONLY BE A MINIMAL CHANCE FOR SEVERE WEATHER. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... A CHANCE OF STORMS REMAINS EAST OF I-79 TUESDAY NIGHT...BUT ONLY THE RIDGES SHOULD HAVE A CHANCE FOR PRECIPITATION AFTER MIDNIGHT. BY WEDNESDAY MORNING HIGH PRESSURE WILL BE CENTERED OVER LOWER MICHIGAN...AND THE HIGH WILL DRIFT INTO QUEBEC THROUGH THE REST OF THE PERIOD. WITH LAKE ERIE TEMPERATURES STILL IN THE 60S AND NORTHERLY WINDS WEDNESDAY AND WEDNESDAY NIGHT...TEMPERATURES WILL BE A FEW DEGREES BELOW NORMAL DURING THAT TIME. AS WINDS SHIFT TO THE EAST FOR THURSDAY...HIGHS WILL RISE BY A FEW DEGREES. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOW UPPER LEVEL RIDGE BUILDING ACROSS THE EASTERN U.S. THIS PERIOD, AS UPPER LEVEL TROUGHING IS PROJECTED ACROSS THE WESTERN U.S. HENCE EXPECT THE UPPER OHIO VALLEY TO BE DRY THROUGH THE WEEKEND WITH TEMPERATURES EACH DAY SLIGHTLY WARMER THAN THE PREVIOUS. BLEND OF GFS AND ECMWF MOS SHOW TEMPERATURES FRIDAY TO BE NEAR NORMAL, THEN GRADUALLY WARMING TO VALUES 5 TO 8 DEGREES WARMER THAN NORMAL SUNDAY AND MONDAY. BY EARLY NEXT WEEK, THE SURFACE HIGH CENTER COULD BE OFFSHORE, BECOMING WHAT IS TERMED A BERMUDA HIGH, WHICH WOULD ALLOW WEAK LOWLEVEL SOUTHERLY WINDS TO BRING INCREASING HUMIDITY TO THE UPPER OHIO VALLEY. THIS WOULD PROMOTE A SLIGHT CHANCE OF LATE DAY INSTABILITY THUNDERSTORMS STARTING MONDAY OR TUESDAY. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... BLEND OF RECENT RADAR AND SURFACE DATA, COUPLED WITH HRRR AND WRF-NMM MODEL OUTPUT, SHOW A PREFRONTAL SURGE OF MVFR SHOWERS TO MOVE NORTHWARD THROUGH THE UPPER OHIO VALLEY THROUGH EARLY EVENING. AS SURFACE TEMPERATURES WARM PAST 78, ISOLATED THUNDERSTORMS CAN DEVELOP. MVFR CONDITIONS WILL BE PREVALENT TONIGHT, AND MAY LOWER TO IFR LATE TONIGHT, DEPENDING ON THE EXTENT THAT EVAPORATING RAINFALL SATURATES A NOCTURNALLY-COOLING SURFACE LAYER. WITH THE MODELS SHOWING SHOWER COVERAGE DECREASING BY MIDDAY TUESDAY, CONDITIONS CAN LIFT TO VFR PRIOR TO THE COLD FRONTAL PASSAGE, ALTHOUGH A FRONTAL BAND OF SHOWERS AND POSSIBLE THUNDERSTORMS CAN CAUSE A BRIEF TEMPORARY DROP TO MVFR TUESDAY AFTERNOON. SURFACE WINDS WILL BE MAINLY FROM THE SOUTH AT ABOUT 10 KTS THROUGH TUESDAY MORNING, WITH GUSTS TO 20 KTS POSSIBLE THIS AFTERNOON. SURFACE WINDS WILL BE WESTERLY TUESDAY AFTERNOON WITH THE COLD FRONTAL PASSAGE. .OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY... EXCEPT FOR POSSIBLE RESTRICTIONS EARLY WEDNESDAY MORNING IF FOG DEVELOPS, POST FRONTAL DRYING AND ENSUING HIGH PRESSURE SUBSIDENCE WILL PROMOTE VFR INTO THE WEEKEND. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
330 PM EDT MON JUN 11 2012 .SYNOPSIS... A COLD FRONT WILL BRING SHOWERS AND A CHANCE FOR THUNDERSTORMS TONIGHT INTO TUESDAY. HIGH PRESSURE IS THEN EXPECTED TO BRING DRY WEATHER THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TUESDAY/... RADAR SHOWS THAT SHOWERS HAVE MADE PROGRESS ALL THE WAY TO INTERSTATE 80...ALTHOUGH EARLIER RETURNS THIS AFTERNOON HAVE BEEN VIRGA. SHOWERS HAVE BEEN QUITE SCATTERED IN COVERAGE...WITH NO THUNDERSTORMS IN THE REGION EITHER. HAVE CONTINUED TO BACK OFF POPS IN THE NEAR TERM...ALTHOUGH COVERAGE IS EXPECTED TO INCREASE OVER TIME. HAVE CONTINUED LIKELY/CATEGORICAL SHOWERS OVERNIGHT...ALTHOUGH AM CONCERNED THAT HIGH-RESOLUTION MODELS NEVER SHOW ANYTHING RESEMBLING STRATIFORM COVERAGE. WILL CONTINUE SLIGHT CHANCE FOR THUNDER OVERNIGHT AND INTO TUESDAY MORNING...ACCORDING TO SREF CALIBRATED PROBABILITIES. COLD FRONT WILL THEN PASS ACROSS THE REGION LATE TUESDAY MORNING INTO TUESDAY AFTERNOON. SPC HAS CONTINUED TO INCLUDE THE AREA AS A `SEE TEXT` MENTION IN THE DAY 2 CONVECTIVE OUTLOOK. APPEARS THAT MODERATE INSTABILITY WILL BE PRESENT...BUT ONLY LOW VALUES OF WIND SHEAR WILL BE PRESENT. AT THIS POINT...APPEARS AS IF THERE WILL ONLY BE A MINIMAL CHANCE FOR SEVERE WEATHER. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... A CHANCE OF STORMS REMAINS EAST OF I-79 TUESDAY NIGHT...BUT ONLY THE RIDGES SHOULD HAVE A CHANCE FOR PRECIPITATION AFTER MIDNIGHT. BY WEDNESDAY MORNING HIGH PRESSURE WILL BE CENTERED OVER LOWER MICHIGAN...AND THE HIGH WILL DRIFT INTO QUEBEC THROUGH THE REST OF THE PERIOD. WITH LAKE ERIE TEMPERATURES STILL IN THE 60S AND NORTHERLY WINDS WEDNESDAY AND WEDNESDAY NIGHT...TEMPERATURES WILL BE A FEW DEGREES BELOW NORMAL DURING THAT TIME. AS WINDS SHIFT TO THE EAST FOR THURSDAY...HIGHS WILL RISE BY A FEW DEGREES. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOW UPPER LEVEL RIDGE BUILDING ACROSS THE EASTERN U.S. THIS PERIOD, AS UPPER LEVEL TROUGHING IS PROJECTED ACROSS THE WESTERN U.S. HENCE EXPECT THE UPPER OHIO VALLEY TO BE DRY THROUGH THE WEEKEND WITH TEMPERATURES EACH DAY SLIGHTLY WARMER THAN THE PREVIOUS. BLEND OF GFS AND ECMWF MOS SHOW TEMPERATURES FRIDAY TO BE NEAR NORMAL, THEN GRADUALLY WARMING TO VALUES 5 TO 8 DEGREES WARMER THAN NORMAL SUNDAY AND MONDAY. BY EARLY NEXT WEEK, THE SURFACE HIGH CENTER COULD BE OFFSHORE, BECOMING WHAT IS TERMED A BERMUDA HIGH, WHICH WOULD ALLOW WEAK LOWLEVEL SOUTHERLY WINDS TO BRING INCREASING HUMIDITY TO THE UPPER OHIO VALLEY. THIS WOULD PROMOTE A SLIGHT CHANCE OF LATE DAY INSTABILITY THUNDERSTORMS STARTING MONDAY OR TUESDAY. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... BLEND OF RECENT RADAR AND SURFACE DATA, COUPLED WITH HRRR AND WRF-NMM MODEL OUTPUT, SHOW A PREFRONTAL SURGE OF MVFR SHOWERS TO MOVE NORTHWARD THROUGH THE UPPER OHIO VALLEY THROUGH EARLY EVENING. AS SURFACE TEMPERATURES WARM PAST 78, ISOLATED THUNDERSTORMS CAN DEVELOP. MVFR CONDITIONS WILL BE PREVALENT TONIGHT, AND MAY LOWER TO IFR LATE TONIGHT, DEPENDING ON THE EXTENT THAT EVAPORATING RAINFALL SATURATES A NOCTURNALLY-COOLING SURFACE LAYER. WITH THE MODELS SHOWING SHOWER COVERAGE DECREASING BY MIDDAY TUESDAY, CONDITIONS CAN LIFT TO VFR PRIOR TO THE COLD FRONTAL PASSAGE, ALTHOUGH A FRONTAL BAND OF SHOWERS AND POSSIBLE THUNDERSTORMS CAN CAUSE A BRIEF TEMPORARY DROP TO MVFR TUESDAY AFTERNOON. SURFACE WINDS WILL BE MAINLY FROM THE SOUTH AT ABOUT 10 KTS THROUGH TUESDAY MORNING, WITH GUSTS TO 20 KTS POSSIBLE THIS AFTERNOON. SURFACE WINDS WILL BE WESTERLY TUESDAY AFTERNOON WITH THE COLD FRONTAL PASSAGE. .OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY... EXCEPT FOR POSSIBLE RESTRICTIONS EARLY WEDNESDAY MORNING IF FOG DEVELOPS, POST FRONTAL DRYING AND ENSUING HIGH PRESSURE SUBSIDENCE WILL PROMOTE VFR INTO THE WEEKEND. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
209 PM EDT MON JUN 11 2012 .SYNOPSIS... A COLD FRONT WILL BRING SHOWERS AND STORMS THIS AFTERNOON THROUGH TUESDAY, FOLLOWED BY DRY AND SEASONABLE CONDITIONS WEDNESDAY INTO FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... WITH 115PM UPDATE...HAVE BACKED OFF PRECIPITATION BY A FEW MORE HOURS IN MOST LOCATIONS. LOW LEVEL MOISTURE IS TAKING ITS TIME MOVING INTO THE AREA...AND RADAR HAS BEEN SHOWING A LOT OF VIRGA. THE VIRGA SHOULD EVENTUALLY MOISTEN LOW LEVELS AND ALLOW RAIN AT THE SURFACE. ALSO TWEAKED AFTERNOON TEMPERATURES...BUMPING UP NORTHERN COUNTIES UP A DEGREE OR TWO AND DECREASING TEMPERATURES ACROSS EASTERN OHIO WHERE RAINFALL HAS ALREADY ARRIVED. PREVIOUS DISCUSSION FOLLOWS. BASED ON RECENT SATELLITE DATA AND NAM MODEL OUTPUT, EXPECT SKIES TO BECOME MOSTLY CLOUDY ACROSS THE WHOLE UPPER OHIO VALLEY BY MIDDAY, AS DEEP MOISTURE MOVES INTO THE REGION WITH UPPER LEVEL SHORTWAVE MOVING NORTH FROM THE TENNESSEE VALLEY. THIS WILL MERGE WITH A COLD FRONT AND A DEEPER TOUGH MOVING EAST FROM THE UPPER GREAT LAKES TO PRODUCE WIDESPREAD SHOWERS AND THUNDERSTORMS THIS AFTERNOON THROUGH TONIGHT. RAINFALL AMOUNTS OVER ONE HALF INCH WITH LOCALLY AN INCH EXPECTED. SEVERE THREAT WILL BE LIMITED BY A LACK OF LOW LEVEL INSTABILITY AT THE SURFACE AND BEST UPPER LEVEL DYNAMICS WELL WEST OF REGION. WITH MID AND UPPER LEVEL CLOUDS ALREADY ENTERING REGION LOWERED MAX TEMPS TOWARD MAV MOS. QUITE MILD AND HUMID TONIGHT AHEAD OF FRONT. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... SHOWERS AND THUNDERSTORMS WILL BE LIKELY TUESDAY UNTIL THE COLD FRONTAL PASSAGE AND LOW LEVEL DRYING TOWARD EVENING. ISOLATED SEVERE THREAT WITH AMOUNT OF AVAILABLE INSTABILITY IN DOUBT AS WELL AS WEAKENING UPPER LEVEL DYNAMICS. TRENDED TOWARD THE NAM AND ECMWF FOR SHOWERS TO DIMINISH WEST TO EAST TUESDAY EVENING AS DRY AIR WORKS ACROSS REGION. MODELS THEN IN GOOD OVERALL AGREEMENT FOR DRY HIGH PRESSURE TO MOVE EAST WITH MUCH LOWER DEW POINTS AND NEAR NORMAL TEMPERATURES WEDNESDAY AND THURSDAY. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOW UPPER LEVEL RIDGE BUILDING ACROSS THE EASTERN U.S. THIS PERIOD, AS UPPER LEVEL TROUGHING IS PROJECTED ACROSS THE WESTERN U.S. HENCE EXPECT THE UPPER OHIO VALLEY TO BE DRY THROUGH THE WEEKEND WITH TEMPERATURES EACH DAY SLIGHTLY WARMER THAN THE PREVIOUS. BLEND OF GFS AND ECMWF MOS SHOW TEMPERATURES FRIDAY TO BE NEAR NORMAL, THEN GRADUALLY WARMING TO VALUES 5 TO 8 DEGREES WARMER THAN NORMAL SUNDAY AND MONDAY. BY EARLY NEXT WEEK, THE SURFACE HIGH CENTER COULD BE OFFSHORE, BECOMING A WHAT IS TERMED A BERMUDA HIGH, WHICH WOULD ALLOW WEAK LOWLEVEL SOUTHERLY WINDS TO BRING INCREASING HUMIDITY TO THE UPPER OHIO VALLEY AND SO PROMOTE A SLIGHT CHANCE OF LATE DAY INSTABILITY THUNDERSTORMS STARTING MONDAY OR TUESDAY. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... BLEND OF RECENT RADAR AND SURFACE DATA, COUPLED WITH HRRR AND WRF-NMM MODEL OUTPUT, SHOW A PREFRONTAL SURGE OF MVFR SHOWERS TO MOVE NORTHWARD THROUGH THE UPPER OHIO VALLEY THROUGH EARLY EVENING. AS SURFACE TEMPERATURES WARM PAST 78, ISOLATED THUNDERSTORMS CAN DEVELOP. MVFR CONDITIONS WILL BE PREVALENT TONIGHT, AND MAY LOWER TO IFR LATE TONIGHT, DEPENDING ON THE EXTENT THAT EVAPORATING RAINFALL SATURATES A NOCTURNALLY-COOLING SURFACE LAYER. WITH THE MODELS SHOWING SHOWER COVERAGE DECREASING BY MIDDAY TUESDAY, CONDITIONS CAN LIFT TO VFR PRIOR TO THE COLD FRONTAL PASSAGE, ALTHOUGH A FRONTAL BAND OF SHOWERS AND POSSIBLE THUNDERSTORMS CAN CAUSE A BRIEF TEMPORARY DROP TO MVFR TUESDAY AFTERNOON. SURFACE WINDS WILL BE MAINLY FROM THE SOUTH AT ABOUT 10 KTS THROUGH TUESDAY MORNING, WITH GUSTS TO 20 KTS POSSIBLE THIS AFTERNOON. SURFACE WINDS WILL BE WESTERLY TUESDAY AFTERNOON WITH THE COLD FRONTAL PASSAGE. .OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY... EXCEPT FOR POSSIBLE RESTRICTIONS EARLY WEDNESDAY MORNING IF FOG DEVELOPS, POST FRONTAL DRYING AND ENSUING HIGH PRESSURE SUBSIDENCE WILL PROMOTE VFR INTO THE WEEKEND. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
419 PM EDT MON JUN 11 2012 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 419 PM EDT MON JUN 11 2012 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A FAIRLY DEEP TROF AND ASSOC STRONG SHORTWAVE MOVING FM ND INTO NW MN. THE EASTWARD MOVEMENT OF THIS SHORTWAVE IS HELPING TO SLOWLY PUSH A SFC COLD FRONT ACROSS WRN UPPER MI THIS AFTERNOON. LATEST 19Z SFC PLOT/ANALYSIS SHOWS THE FRONT IS ALONG A CRYSTAL FALLS-MICHIGAMME LINE. ALTHOUGH 12Z MODEL SNDGS INDICATE IN EXCESS OF 1000 J/KG MLCAPE WITH T/TD OF 82/63...VIS SATELLITE LOOP SHOWS LITTLE DVLPMT TO CU FIELD UPSTREAM OVER CENTRAL UPPER MI OR IMMEDIATELY UPSTREAM OVER NRN WI. SUSPECT THAT DRY ALOFT MOVING IN AHEAD OF THE SHORTWAVE AS NOTED ON VERY DRY 12Z KMPX SNDGS MAY BE INHIBITING CU DVLPMT OVER THE FCST AREA. TONIGHT...GIVEN LACK OF CU DVLPMT ON VIS SATELLITE MAY END UP EVENTUALLY HAVING TO BACK OFF ON POPS TO SLIGHT CHC OVER CENTRAL AND ERN COUNTIES FOR THIS EVENING AHEAD OF APPROACHING FRONT. IF SOME CONVECTION IS ABLE TO FIRE ALONG THE FRONT...THERE IS A CHANCE FOR AN ISOLATED STRONG TO SVR STORM GIVEN THE INSTABILITY AND DEEP LAYER SHEAR GREATER THAN 40 KTS OVER THE AREA. RELUCTANT TO PULL POPS OUT COMPLETELY SINCE FRONT IS STILL APPROACHING BUT CHC OF PCPN IS LOOKING MORE AND MORE DOUBTFUL THIS EVENING OVER CENTRAL AND ERN CWA. MODEL SNDGS INDICATE WEST WINDS ARE EXPECTED TO PICK UP BEHIND THE FRONT THIS EVENING ESPECIALLY OVER THE KEWEENAW PENINSULA WHERE PASSAGE OF SECONDARY COLD FRONT AND INCREASING MIXING/INSTABILITY WITH COLDER AIR COMING IN MAY PRODUCE GUSTS TO 40 MPH. LOOK FOR LOWS TO REACH INTO THE MID 40S WEST TO MID 50S SOUTH CENTRAL AND EAST. TUESDAY...THE 500MB TROUGH AXIS WILL MOVE ACROSS THE AREA MIDDAY ALONG WITH THE 8H THERMAL TROF AS 850 MB TEMPS LOWER TO AROUND 0C. WITH GOOD CAA IN THE WNW FLOW OVER THE AREA. WITH LIMITED MIXING ALONG THE LAKE SUPERIOR SHORE EXPECT HIGHS IN THE LOWER TO MID 50S WHILE DEEPER SOUTH CENTRAL WILL YIELD HIGHS IN THE LOWER TO MID 60S. INCREASINGLY ANTICYCLONIC SFC-850 MB FLOW AND RDGG BUILDING IN FROM THE WEST SHOULD SCOUR OUT LOW CLOUDS FROM WEST TO EAST IN THE AFTERNOON. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 419 PM EDT MON JUN 11 2012 THE SFC HIGH SHOULD BE DIRECTLY OVERHEAD FROM 00-06Z WEDNESDAY...BEFORE SHIFTING OFF TO QUEBEC WEDNESDAY AFTERNOON INTO THURSDAY. SIMILAR TO A FEW DAYS AGO...WE WILL MONITOR THE DEVELOPMENT OF AN ELONGATED SFC LOW STRETCHING FROM S CENTRAL CANADA THROUGH THE CO ROCKIES. FROST WILL REMAIN POSSIBLE TUESDAY NIGHT/WEDNESDAY MORNING...WITH TEMPS BOTTOMING OUT 31-36F INLAND FROM THE GREAT LAKES AS WINDS GO NEARLY CALM AND CLOUDS DISSIPATE. WEDNESDAY WILL LIKELY BE A BIT DRIER THAN ORIGINALLY THROUGH...WITH MIXED DEW POINTS IN THE MID 20S BY 18Z. THIS SCENARIO WOULD RESULT IN MIN RH VALUES NEAR 20 PERCENT OVER THE WEST HALF OF UPPER MI...AND 25-30 PERCENT EAST. EXPECT THE RETURN OF LIGHT/SOUTHERLY FLOW AS THE HIGH SHIFTS ACROSS LAKE HURON AND STRETCHES THROUGH QUEBEC...STILL BELOW 15MPH. DID PUSH THE FCST CLOSER TO THESE LOWEST VALUES. THE ELONGATED SFC LOW STRETCHING FROM SOUTHERN SASKATCHEWAN/MANITOBA THROUGH THE DAKOTAS AND E CO/NM THURSDAY MORNING WILL CONTINUE TO REMAIN NEARLY STEADY. ALTHOUGH THURSDAY SHOULD BE WARMER...WITH INCREASED SOUTHERLY WINDS /20-35KTS BETWEEN THE SFC AND 850MB/...MOISTURE SHOULD BE ON THE INCREASE AS WELL. MIN RH VALUES COULD STILL NEAR 30 PERCENT OVER PORTIONS OF INTERIOR W UPPER MI BY LATE MORNING/EARLY AFTERNOON. THE FCST FOR SUNDAY MONDAY REMAINS VERY UNCERTAIN...SO DID NOT GO TOO FAR IN DEPTH WITH ADJUSTMENTS FOR THAT PERIOD. THE WESTERN SFC LOW WILL BE LOCATED SOMEWHERE BETWEEN NWS ONTARIO AND MN BY 12Z MONDAY...WITH THE TRAILING COLD FRONT STILL REMAINING TO OUR W BY THE END OF THE DAY. THE RESULT SHOULD BE ANOTHER ROUND OF WARM/HOT WEATHER SATURDAY THROUGH MONDAY...AS S WINDS REMAIN STEADY AND 850MB TEMPS RISE AGAIN TO 16 TO 20C. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 155 PM EDT MON JUN 11 2012 VFR CONDITIONS SHOULD PREVAIL INTO THE EVENING HRS AT KIWD/KCMX/KSAW. SCT -SHRA/-TSRA COULD FORM BTWN 18-00Z IN VCNTY OF KSAW ALONG INCOMING COLD FRONT BUT GIVEN CONSIDERABLE UNCERTAINTY IN PLACEMENT/COVERAGE OF AFTN CONVECTION DUE TO CLOUD COVER...SHRA/TSRA WERE NOT MENTIONED AT KSAW. WEST WINDS COULD BECOME GUSTY AND PICK UP SUBSTANTIALLY AT KIWD AND ESPECIALLY KCMX AS A SECONDARY COLD FRONT PASSES THRU THE AREA LATE AFTN/EVENING. LOOKING UPSTREAM...MVFR CIGS COULD DEVELOP OVERNIGHT AT KIWD AND KCMX AND THEN LATE TUE MORNING AT KSAW WITH PASSAGE OF SECONDARY COLD FRONT. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 419 PM EDT MON JUN 11 2012 LOW PRESSURE ACROSS HUDSON BAY WILL KEEP A TROUGH ACROSS LS THIS EVENING...AHEAD OF HIGH NEARING FROM THE WEST. EXPECT THE HIGH OVER MINNESOTA TUESDAY MORNING TO PUSH ACROSS THE UPPER GREAT LAKES TUESDAY AFTERNOON THROUGH WEDNESDAY...BEFORE EXITING ACROSS QUEBEC WEDNESDAY NIGHT. W-NW GUSTS OF 30 TO POSSIBLY 30KTS WILL SLIDE IN OVERNIGHT AND LINGER THROUGH THE DAY TUESDAY. A RIDGE WILL REMAIN ACROSS LS THROUGH SATURDAY...AS AN ELONGATED AREA OF LOW PRESSURE ORGANIZES ACROSS THE CENTRAL AND NORTHERN PLAINS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...KF AVIATION...VOSS MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
157 PM EDT MON JUN 11 2012 .SHORT TERM...(TODAY) ISSUED AT 518 AM EDT MON JUN 11 2012 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A FAIRLY DEEP TROF MOVING ACROSS THE NRN PLAINS. AS EXPECTED DUE TO WEAKENING INSTABILITY... SHRA/TSRA THAT DEVELOPED YESTERDAY AFTN AHEAD OF COLD FRONT IN MN DIMINISHED AS THEY APPROACHED UPPER MI EARLIER IN THE NIGHT. HOWEVER...A LINGERING RIBBON OF MUCAPE WHICH HAS RECENTLY INCREASED TO 500-1000J/KG PER LATEST SPC MESOANALYSIS IS SUPPORTING SCT SHRA/TSRA WHICH ARE SPREADING/DEVELOPING NE INTO THE WRN FCST AREA AS OF 09Z. MAIN CONCERN IN THE SHORT TERM REVOLVES AROUND REDEVELOPMENT OF CONVECTION TODAY AS COLD FRONT DRIFTS ACROSS THE AREA. SHRA/TSRA SPREADING INTO WRN UPPER MI WILL PROBABLY PERSIST FOR THE NEXT FEW HRS GIVEN AVBL INSTABILITY. COLD FRONT SHOULD THEN CLEAR THE W BEFORE REDEVELOPMENT CAN OCCUR TODAY. TO THE E...DEBRIS CLOUDS FROM SHRA/TSRA WILL PROBABLY THIN OUT SUFFICIENTLY TO ALLOW FOR DECENT HEATING AHEAD OF THE COLD FRONT AS IT MOVES ACROSS CNTRL UPPER MI THIS AFTN. UTILIZING MODIFIED NAM FCST SOUNDINGS FOR T/TD OF MID 80S/LWR 60S PRIOR TO MODEL GENERATED PCPN (GFS SOUNDING CONTAMINATED BY PCPN) YIELDS SBCAPE IN THE 1000-1500J/KG RANGE. WITH DEEP LAYER SHEAR OF 30-40KT...THERE WILL BE THE POTENTIAL FOR ORGANIZED STORMS AND SVR WX. HIGH RES MODELS GIVE CONFLICTING SIGNALS ABOUT WHETHER CONVECTION WILL REDVELOP AS SEVERAL INDICATE LITTLE OR NO REGENERATION TODAY. HOWEVER...GIVEN POTENTIAL INSTABILITY...SEEMS PRUDENT TO MENTION AT LEAST SCT SHRA/TSRA THIS AFTN. A QUICK CHECK OF THE 06Z LOCAL HIGH RES WRF AND 4KM NAM ARE VERY SUPPORTIVE OF THIS IDEA AS THEY SHOW CONVECTION DEVELOPING ACROSS CNTRL UPPER MI EARLY THIS AFTN AND THEN SPREADING E. APPEARS THE AREA FROM ROUGHLY CRYSTAL FALLS TO ISHPEMING EASTWARD WILL HAVE THE POTENTIAL FOR SVR STORMS THIS AFTN. SVR POTENTIAL SHOULD BE LOWER TOWARD LAKE MICHIGAN ACROSS SE DELTA/SRN SCHOOLCRAFT COUNTIES WITH SRLY FLOW/MARINE INFLUENCE OFF THE LAKE. OTHER ITEM OF NOTE TODAY IS THE DRIER AIR MOVING INTO WRN UPPER MI BEHIND FRONT. SEVERAL PIECES OF GUIDANCE SUGGEST DWPTS FALLING INTO THE UPPER 40S WHICH RESULTS IN RH FALLING TO AROUND 30PCT THIS AFTN. WITH WINDS GUSTING TO 20-25MPH THIS AFTN...THERE WILL BE AN INCREASED RISK OF WILDFIRES WHERE SIGNIFICANT RAINFALL HAS NOT OCCURRED RECENTLY. .LONG TERM...(TONIGHT THROUGH SUNDAY) ISSUED AT 518 AM EDT MON JUN 11 2012 FOR THE START OF THE PERIOD 00Z TUE...A MID LEVEL SHORTWAVE TROUGH AXIS WILL BE FROM WRN HUDSON BAY TO CENTRAL MN...WITH A SFC LOW OVER CENTRAL NRN ONTARIO. A COLD FRONT/SFC TROUGH WILL STRETCH S TO CENTRAL UPPER MI BY 00Z TUE. SOME SHOWERS AND THUNDERSTORMS WILL BE ONGOING ALONG AND AHEAD OF THE COLD FRONT...BUT THE DRY SLOT WILL BE MOVING IN AROUND THIS TIME DURING LOSS OF DAYTIME HEATING. THERE IS A POSSIBILITY OF SOME ELEVATED CONVECTION LATE IN THE EVENING OR EARLY OVERNIGHT...BUT I THINK THE DRY AIR WILL KEEP THAT FROM HAPPENING. WILL DEPICT PRECIP WITH CHANCE POPS MOVING OUT OF THE CWA BY 06Z TUE. BY 12Z TUE...THE 500MB TROUGH AXIS WILL BE FROM ERN HUDSON BAY TO WRN LAKE SUPERIOR...WITH THE SFC LOW NEAR JAMES BAY AND SFC HIGH PRESSURE MOVING INTO WRN MN. THE COLD FRONT WILL BE E OF THE CWA...WITH GOOD CAA IN THE WNW LOW LEVEL FLOW OVER THE AREA. 850MB TEMPS WILL BE AROUND 3C E AND -1C W. BY 18Z TUE...THE 500MB TROUGH AXIS WILL BE OVER THE CENTER OF THE CWA...WITH THE SFC HIGH BEGINNING TO MOVE INTO THE WRN CWA. 850MB TEMPS AT 18Z WILL RANGE FROM -2C N TO 2C S. BY 00Z WED...THE 500MB TROUGH AXIS WILL BE OVER FAR ERN UPPER MI...WHILE THE SFC HIGH WILL BE OVER MOST OF THE CWA. MODEL SOUNDING SUGGEST MIXING TO AROUND 825MB TUE...RESULTING IN HIGHS IN THE 50S N TO 60S S...AND LOW DEW PTS. THE SFC HIGH WILL BE CENTERED OVER THE CWA TUE NIGHT...WHICH WILL LEAD TO FROST POTENTIAL AS COOL TEMPS TUE DROP QUICKLY UNDER MOSTLY CLEAR SKIES. WENT WITH THE LOW SIDE OF TEMP GUIDANCE...WITH MANY LOCATIONS OVER THE INTERIOR DROPPING NEAR OR BELOW FREEZING. WILL KEEP MENTION OF FROST IN HWO. WED THROUGH FRI...THE SFC HIGH MOVES E WHILE SFC LOW PRESSURE DEVELOPS WELL TO OUR W IN RESPONSE TO A SERIES OF SHORTWAVES. THE RESULTING SLY FLOW IN THE LOW LEVELS BRINGS OFF AND ON CONVECTION FROM LATE WED THROUGH FRI...BUT MODELS INDICATE MOST OF THAT STAYING W OF THE CWA AND INTO WRN LAKE SUPERIOR. WILL KEEP FORECAST FOR UPPER MI DRY THROUGH THIS PERIOD AS A DRIER PATTERN HAS VERIFIED BETTER RECENTLY...AND MOST MODELS KEEP US DRY ANYWAYS. AN UPPER RIDGE WILL BUILD INTO THE AREA FROM THE S...BRINGING STEADILY INCREASING TEMPS WED THROUGH AT LEAST FRI. BY FRI...850MB TEMPS SHOULD BE UP TO 16C...THEN UP TO 18C ON SAT AND SUN. MODELS DIVERGE ON SOLUTIONS FOR THE WEEKEND...WITH THE 12Z/10 ECMWF BRINGING A TROUGH PUSHING IN FROM THE NW...WHILE THE 00Z/11 GFS KEEPS THE UPPER RIDGE IN PLACE. USED A CONSENSUS OF MODELS FOR THE WEEKEND GIVEN LOW CONFIDENCE IN ANY PARTICULAR MODEL SOLUTION. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 155 PM EDT MON JUN 11 2012 VFR CONDITIONS SHOULD PREVAIL INTO THE EVENING HRS AT KIWD/KCMX/KSAW. SCT -SHRA/-TSRA COULD FORM BTWN 18-00Z IN VCNTY OF KSAW ALONG INCOMING COLD FRONT BUT GIVEN CONSIDERABLE UNCERTAINTY IN PLACEMENT/COVERAGE OF AFTN CONVECTION DUE TO CLOUD COVER...SHRA/TSRA WERE NOT MENTIONED AT KSAW. WEST WINDS COULD BECOME GUSTY AND PICK UP SUBSTANTIALLY AT KIWD AND ESPECIALLY KCMX AS A SECONDARY COLD FRONT PASSES THRU THE AREA LATE AFTN/EVENING. LOOKING UPSTREAM...MVFR CIGS COULD DEVELOP OVERNIGHT AT KIWD AND KCMX AND THEN LATE TUE MORNING AT KSAW WITH PASSAGE OF SECONDARY COLD FRONT. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 518 AM EDT MON JUN 11 2012 AHEAD OF A COLD FRONT...S WINDS WILL BE IN THE 15-25KT RANGE OVER ERN LAKE SUPERIOR TODAY...ESPECIALLY EARLY IN THE DAY. SOME OF THE HIGHER OBSERVING PLATFORMS WILL SEE WINDS TO AROUND 30KT. BEHIND THE COLD FRONT...A PUSH OF STRONGER WESTERLY WINDS TO 25-30KT WILL ARRIVE OVER WRN LAKE SUPERIOR MID/LATE AFTN. THESE STRONGER WINDS WILL THEN SPREAD ACROSS THE LAKE TONIGHT. LOOK FOR THE WINDS TO GRADUALLY DIMINISH FROM W TO E TUE WITH WINDS FALLING BLO 15KT TUE NIGHT AS HIGH PRES ARRIVES OVER THE UPPER LAKES. WINDS WED THRU FRI SHOULD BE UNDER 20KT AS PRES GRADIENT REMAINS RELATIVELY WEAK BTWN THE DEPARTING HIGH AND A LOW PRES TROF SETTING UP WELL TO THE W AND NW. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1220 PM CDT Mon Jun 11 2012 ...UPDATED AVIATION DISCUSSION... .DISCUSSION... Short Term (Tonight-Wednesday) Overnight, the focus was on two lines of convection: the leading line being the advancing gust front and the second line being focused along the cold front. The showers and thunderstorms along the gust front continued to weaken through the overnight hours, with the bit of remnant activity tracking southeast of the Missouri River by 09Z. The better area of convective activity was focused along the cold front that was stretching roughly along a line from North Kansas City to Cameron and Bethany around 09Z. The activity was remaining well below severe limits with 1000-1500 J/kg MUCAPE, weak shear, and poor lapse rates present. This line of thunderstorms had been fairly slow-moving, but has become a bit more progressive toward the southeast with the help of 20-25kt 850mb winds. This slow tracking was resulting in higher rainfall rates across extreme northeast Kansas and northwest Missouri, with some locations likely accumulating more than one inch of rain within an hour. HRRR shows the line of thunderstorms stretching along a Kansas City to Chillicothe line by around 10Z, progressing just south of the Missouri River by around 13Z. Short range models are in fairly good agreement that this thunderstorm activity will shift southeast of the forecast area late this morning, but cannot rule out a few lingering showers and thunderstorms across central Missouri early this afternoon. Winds will shift to the northwest behind the advancing cold front. However, cold air advection behind the cold front will be limited today so should see afternoon temperatures still warmer than normal -- into the middle 80s. High pressure will build in across the Northern and Central Plains later this afternoon and track toward the Great Lakes region by the middle of the week, keeping conditions dry. Temperatures look to be near to slightly above seasonal normals through Wednesday as winds shift from northeast to southeast with the eastward-moving surface high. As the upper level trough over the Northern Plains progresses toward the northern Great Lakes, a more zonal flow will set up across the western and central CONUS through mid-week. Models have shown the potential for a few disturbances to develop within the zonal flow primarily west of the forecast area across Kansas. Confidence is low in whether or not any of these impulses will spread enough eastward to clip eastern Kansas and extreme western Missouri Wednesday and Wednesday night, so have nothing more than slight chance pops in for that area. ACH Medium Range (Thursday through Sunday)... Prefer a wait and see approach as it relates to rain chances during the medium range period. The 00z ECMWF and GFS build mid level heights, with the ECMWF developing a closed high, across the mid MO River Valley while a western U.S. trough builds. While it`s certainly possible a weak vorticity lobe or two will meander across the Central Plains Thursday or Friday within a chaotic and weak westerly flow coming out of the Rockies, confidence is low on just how much convection, if any can make it into the CWA. Agree with the previous discussion in favoring the drier ECMWF over the relatively wet GFS. As such can only justify slight chance pops until the end late Sunday when falling heights across the Plains in response to the approaching upper trough offers some hope that increasing dynamics will generate some scattered convection. A gradual warm up on temperatures and dewpoints continues to look in order with readings in the upper 80s/90 by the weekend. MJ && .AVIATION... For the 18z TAFs: Secondary cold front beginning to push through the terminals early this afternoon will allow drier air to filter southward. Scattered strato-cu deck behind this front and ahead of 850 trough will persist into the afternoon hours. Skies will clear by this evening and remain VFR though the overnight period. Will need to monitor for the potential of fog development near daybreak at the terminals as winds turn light. Recent rainfall combined with these light winds may support development, but advection of drier air from the northwest will also inhibit development. Dux && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ WFO EAX
AREA FORECAST DISCUSSION
NWS GLASGOW MT
257 PM MDT MON JUN 11 2012 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH WEDNESDAY... A WEAK UPPER RIDGE OVER THE PACIFIC NORTHWEST INTO ALBERTA WILL MOVE OVER THE NORTHERN ROCKIES TONIGHT INTO TOMORROW. A WEAK SHORTWAVE WILL UNDERCUT THE UPPER RIDGE ON TUESDAY. ANOTHER SLIGHTLY STRONGER SHORTWAVE TROUGH WILL ROTATE AROUND THE UPPER LOW OVER THE GULF OF ALASKA AND MOVE OVER THE NORTHERN ROCKIES TUESDAY NIGHT INTO WEDNESDAY. THIS AFTERNOON AND EVENING THE WINDS WILL CONTINUE TO DROP OFF AS THE PRESSURE GRADIENT RELAXES AS A SURFACE HIGH MOVES IN FROM THE SOUTHWEST. SO WILL CANCEL THE LAKE WIND ADVISORY WITH THE AFTERNOON PACKAGE...A FEW HOURS EARLIER THEN EXPECTED. COULD BE SOME SCATTERED SHOWERS AROUND WITH SOME ISOLATED THUNDERSTORMS MOVING ACROSS THE REGION THIS EVENING WHICH WAS INDICATED ON THE LATEST HRRR RUN. THIS ACTIVITY WILL END BEFORE MIDNIGHT SO DROPPED POPS DOWN TO NOTHING AFTER THAT. TUESDAY...ADDED SOME SLIGHT CHANCE POPS OVER MY SW ZONES AS THE WEAK WAVE MOVES ACROSS SOUTHERN MONTANA. MODELS SOUNDING DO SHOW A SMALL AMOUNT OF ELEVATED CAPE ACROSS THE REGION SO A FEW ISOLATED STORMS ARE POSSIBLE SO WENT WITH A SLIGHT CHANCE OF THUNDER FOR TUESDAY AFTERNOON AND EVENING. TUESDAY NIGHT THROUGH WEDNESDAY...THE SLIGHTLY STRONGER SHORTWAVE WILL MOVE INTO WESTERN MONTANA WHICH WILL HELP GENERATE SOUTHWEST FLOW OVER EASTERN MONTANA. THIS WILL HELP TO DESTABILIZE THE MID LEVELS AHEAD OF THE SHORTWAVE. CAPE VALUES ARE ONCE AGAIN WEAK AND ELEVATED OTHER THUNDERSTORM PARAMETERS ARE WEAK AS WELL. THE THINKING AT THIS TIME IS JUST GENERAL THUNDER POSSIBLE FOR WEDNESDAY AFTERNOON AND EVENING. RSMITH .LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY... THE EXTENDED PERIOD BEGINS WITH AN UPPER LEVEL SHORTWAVE TROUGH MOVING OVER MONTANA THURSDAY NIGHT. THE ASSOCIATED COLD FRONT SWINGS ACROSS THE AREA...MEETING MODERATE INSTABILITY...GENERATING THUNDERSTORMS IN THE EVENING. TIMING IS NOT CERTAIN WITH THIS WAVE DUE TO DIFFERENCES BETWEEN THE 12Z GFS AND THE 00Z ECMWF. THESE DIFFERENCES CONTINUE THROUGH THE ENTIRE PERIOD. ALTHOUGH NOT CERTAIN...THERE APPEARS TO BE A BREAK IN THE ACTION ON THURSDAY AND FRIDAY WITH A SHORT PERIOD UPPER RIDGE. THIS RIDGE GETS OVERTAKEN BY THE NEXT UPPER TROUGH LATE FRIDAY. FROM THIS POINT ON THE MODELS AGREE WITH AN UPPER TROUGH ONLY IN GENERAL...BUT DIFFER TOTALLY WITH THE EMBEDDED FEATURES. LATE IN THE SHIFT THE 12Z EC CONTINUES THE DISAGREEMENT WITH THE GFS. AGREE THE BEST BET IS TO MAINTAIN CHANCE POPS AND COOLER TEMPERATURES THROUGH THE ENTIRE PERIOD UNTIL BETTER AGREEMENT IS OBTAINED. SCT PREVIOUS DISCUSSION... SHORTWAVE TROUGH EXITS THE AREA WEDNESDAY NIGHT WITH LINGERING SHOWERS AND THUNDERSTORMS POSSIBLE ESPECIALLY IN THE NORTHEAST. HIGH PRESSURE SYSTEM AND SHORTWAVE RIDGE WILL BE OVER THE AREA ON THURSDAY WITH MAINLY DRY WEATHER. THE WESTERN ZONES COULD SEE A SHOWER OR THUNDERSTORM IN THE AFTERNOON AHEAD OF THE NEXT SYSTEM. AN UPPER TROUGH WILL BE OVER MONTANA AND NEARBY AREAS OVER THE WEEKEND AND EARLY NEXT WEEK. THERE ARE DIFFERENCES BETWEEN THE MODELS ON HOW THE TROUGH WILL BE CONFIGURED...TIMING OF SHORTWAVES WITHIN THE TROUGH AND WHEN AND WHERE INDIVIDUAL STORMS WILL OCCUR. NORTHEAST MONTANA WILL SEE RAIN WITH SHOWERS AND THUNDERSTORMS AT TIMES OVER THE PERIOD BUT MODEL CONFIDENCE IS TOO LOW TO TIME WHEN RAIN WILL OCCUR AT THIS POINT. PREVIOUS FORECAST IDEA OF A 30 TO 40 POP BROAD-BRUSH LOOKS REASONABLE FOR NOW. FORRESTER && .AVIATION... VFR. AN UPPER LEVEL RIDGE WILL MOVE ACROSS NORTHEAST MONTANA TONIGHT WHICH SHOULD END THE THREAT OF SHOWERS AND REDUCE SKY COVER. IN ADDITION A WEAK SURFACE PRESSURE DIFFERENCE WILL REDUCE WINDS TO LIGHT AND VARIABLE TONIGHT. ON TUESDAY A WEAK SHORTWAVE TROUGH NUDGES INTO THE NORTHERN ROCKIES LEADING TO THUNDERSTORMS. ALTHOUGH NORTHEAST MONTANA WILL DEVELOP MODERATE INSTABILITY...THE LACK OF LOCAL DISTURBANCES WILL DIMINISH THE THREAT OF THUNDERSTORMS. WITH A BROAD LEE SURFACE TROUGH...EXPECT WESTERLY WINDS TO REMAIN LESS THAN 15KTS. SCT && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && $$ WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1226 PM CDT MON JUN 11 2012 .AVIATION... /FOR THE 11.18Z TAF ISSUANCE/ MINIMAL AVIATION CONCERNS THROUGH MID-DAY TUESDAY. FAIR WEATHER CUMULUS WILL OCCUR OVER NORTHERN NEBRASKA THIS AFTERNOON...BUT CEILINGS WILL REMAIN VFR. HIGH PRESSURE WILL BUILD INTO THE UPPER MIDWEST TONIGHT AND TUESDAY WHICH WILL CAUSE WINDS TO DECREASE AND SHIFT THE NORTH WINDS AROUND TO THE SOUTH BY TUESDAY MORNING. THE BOUNDARY LAYER IS EXPECTED TO BECOME WELL MIXED AGAIN ON TUESDAY SO WILL SEE GUSTY CONDITIONS IN THE LATE MORNING AND AFTERNOON. FORECAST SOUNDINGS SHOWING AN INCREASE IN MOISTURE AT THE MID- LEVELS SO SHOULD SEE INCREASED CLOUD COVER TUESDAY...HOWEVER WILL REMAIN VFR. && .PREV DISCUSSION... /ISSUED 838 AM CDT MON JUN 11 2012/ UPDATE... HRRR AND RAP INDICATE LOWER 80S ACROSS SWRN NEB THIS AFTN. THE HRRR AND RAP WERE DEAD ON SUNDAY ACROSS THIS AREA SO THE FCST HAS BEEN UPDATED FOR SLIGHTLY WARMER TEMPS. REST OF FCST OKAY FOR NOW. PREV DISCUSSION... /ISSUED 300 AM CDT MON JUN 11 2012/ DISCUSSION... PACIFIC HIGH PRESSURE WILL BUILD EAST INTO THE CNTRL/NRN PLAINS TODAY. BREEZY NORTHWEST WINDS STARTING THE DAY BEHIND A SECONDARY COLD FRONTAL PASSAGE...WILL DIMINISH THIS AFTERNOON AS THE HIGH PRESSURE BUILDS IN. AIRMASS ACROSS THE AREA IS VERY DRY...WITH A DOWNSLOPE WIND COMPONENT AIDING THE DRYNESS. DEW POINTS GENERALLY IN THE 30S TODAY...WILL CREATE AFTERNOON RELATIVE HUMIDITY VALUES IN THE 15 TO 25 PERCENT RANGE. FORTUNATELY WINDS WILL BE DIMINISHING DURING THE PERIOD OF LOWEST RELATIVE HUMIDITY...SO FIRE WEATHER HEADLINES ARE NOT EXPECTED TO BE NEEDED. SOME GULF MOISTURE BEGINS TO RETURN NORTH INTO THE AREA TUESDAY...BUT REALLY DOESN/T GET INTO FULL SWING UNTIL TUESDAY NIGHT...WHEN H85 DEW POINTS RISE TO NEAR 14C ON SOUTHERLY LLJ. MODELS CONTINUE TO INDICATE A DECENT MID LEVEL WAVE WILL INTERACT WITH THE RETURNING MOISTURE...AND SCATTERED TSTM DEVELOPMENT IS POSSIBLE DURING THE AFTERNOON IN UPSLOPE ENVIRONMENT ACROSS THE NEB PANHANDLE/EASTERN WY AND CO. A LITTLE CONCERNED ABOUT THE LACK OF BETTER MOISTURE AT FIRST...SO WILL KEEP CHANCES SLIGHT TUESDAY AFTERNOON...AND INCREASE TO LOW CHANCE TUESDAY NIGHT AS STORMS MOVE EAST INTO AN INCREASINGLY FAVORABLE MOIST/UNSTABLE ENVIRONMENT DUE TO SOUTHERLY 45 KT LLJ. MID LEVEL WAVE AND CONVECTION SHOULD PUSH EAST OF THE AREA WEDNESDAY. A LARGE CLOSED LOW IS EXPECTED TO DEVELOP ACROSS SOUTHWEST CANADA BY THURSDAY. GFS ENSEMBLE MEAN KEEPS THE LOW INVOF SOUTHWEST CANADA THROUGH THE UPCOMING WEEKEND. BUILDING HEAT IS EXPECTED THURSDAY RIGHT THROUGH THE WEEKEND...AS ANY COLD FRONT ASSOCIATED WITH THE LOW STAYS WELL NORTHWEST OF THE AREA. RAIN CHANCES WILL NOT BE NIL HOWEVER...AS THE AREA APPEARS TO BE IN A RATHER ACTIVE SOUTHWEST FLOW ALOFT. LEEWARD TROUGHING DEVELOPS DAILY...AND THIS COULD SERVE FOR CONVECTIVE DEVELOPMENT. MOISTURE IS IN PLACE...WITH A DECENT TRAJECTORY OFF THE GULF DURING THE PERIOD. THE CAVEAT HERE IS POTENTIAL MID LEVEL WARM AIR...WHICH WOULD TEND TO CAP THE ATMOSPHERE. THIS WAS THE CASE THIS PAST WEEK...AND WON/T BE OVER AMBITIOUS WITH RAIN CHANCES AT THIS TIME. && .LBF WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DISCUSSION...TAYLOR UPDATE...CDC AVIATION...BROOKS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
302 PM EDT MON JUN 11 2012 .SYNOPSIS... A TROPICAL AIRMASS WILL CONTINUE TO BRING OCCASIONAL SHOWERS AND THUNDERSTORMS TO THE EASTERN CAROLINAS TONIGHT INTO TUESDAY. LOCALLY HEAVY RAINFALL IS EXPECTED. A WEAK FRONT WILL SLIDE EAST TO THE COAST WEDNESDAY...WITH DRIER AIR BEHIND THE FRONT LEADING TO REDUCED CHANCES OF SHOWERS AND STORMS LATER IN THE WEEK. NORTHEAST WINDS AROUND HIGH PRESSURE TO OUR NORTH WILL BRING SURPRISINGLY MILD TEMPERATURES THIS WEEKEND. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 300 PM WEDNESDAY...SOMEWHAT COMPLICATED SETUP IN PLACE DUE TO THE JUXTAPOSITION OF LATE-SUMMERLIKE TROPICAL MOISTURE AND UPPER PIECES OF ENERGY USUALLY ONLY SEEN ON FRINGES OF SUMMER. MAIN VORT MAX CURRENTLY CLEARLY EVIDENT ON BOTH SAT AND RADAR NR CLT WITH BAND OF HEAVY SHOWERS/EMBEDDED THUNDERSTORMS ALONG ITS LEADING EDGE. THIS HEAVY RAIN WILL SWEEP THROUGH WESTERN COUNTIES OVER THE NEXT COUPLE OF HOURS. THEREAFTER COME A FEW POINTS OF FCST UNCERTAINTY. FOR ONE...SUBSIDENCE BEHIND THE MAIN VORT SHOULD SUPPRESS CONVECTION OVER WRN ZONES FOR NEXT SEVERAL HOURS AS THE VORT MOVES NE AND WEAKENS. SECOND...IT`LL BE INTERESTING TO SEE HOW THE TRAILING/TRAINING BAND OF SHOWERS PERSISTS AND HOW FAR EAST THEY PUSH. MODEL GUIDANCE NOT PERFORMING VERY WELL IN THE 1ST PLACE...BUT SUGGESTS THAT THE MAIN FORCING SHIFTS SOUTH OF THE REGION ASSOC WITH WEAK JETLET TRAILING THE VORT AS THE MAIN PIECE WEAKENS NEAR THE CAPE FEAR REGION. FOR WHAT ITS WORTH THE SRF IS RELUCTANT TO BRING SIGNIFICANT RAIN ASSOC WITH THIS FEATURE ALL THE WAY EAST TO COASTAL NC COUNTIES DUE TO THE UPPER FEATURE WEAKENING. GRANTED...THIS IS ALL JUST REALLY TRYING TO FINE-TUNE POPS...WITH THE LCL SO LOW/500-750M/AREA-WIDE AND THE COLUMN SATURATED THROUGH SUCH A DEEP LAYER VIRTUALLY EVERY LITTLE RIPPLE WILL BE ABLE TO GENERATE SHOWERS THAT WILL PUT DOWN APPRECIABLE RAINFALL. FORECAST THUS STILL BRINGS LIKELY POPS TO NC COAST THIS EVE. A RELATIVE LULL MAY OCCUR LATE EVENING INTO THE FIRST PART OF TONIGHT AS ALL OF THESE SHORTWAVES WEAKEN AND/OR MOVE EAST OUT OF THE AREA. FOCUS WILL THEN SHIFT TO THE IMMEDIATE COASTAL AREAS WHERE ANOTHER CHAIN OF SHEAR VORTS DEVELOP IN THE FLOW AND LEAD TO ASCENT. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...A WET PATTERN WILL CONTINUE INTO TUESDAY WITH PRECIPITABLE WATER AT OR ABOVE 2.00 INCHES AND THE 500 MB TROUGH JUST TO OUR WEST. THE BULK OF THE RAINFALL TUESDAY MORNING SHOULD BE OFFSHORE PERHAPS AFFECTING THE BEACHES...BUT ACTIVITY WILL SHIFT BACK ONSHORE BY MID TO LATE MORNING WITH SLOW-MOVING HEAVY SHOWERS AND ISOLATED TSTMS EXPECTED TO SPREAD ALL THE WAY BACK INTO CENTRAL NC/SC BY EARLY AFTERNOON. PLENTY OF CLOUDS...A NEARLY SATURATED TROPOSPHERE...AND LITTLE VERTICAL WIND SHEAR SHOULD REDUCE OUR SEVERE WEATHER POTENTIAL AND LEAVE LOCALIZED RAINFALL- INDUCED FLOODING AS THE PRIMARY ADVERSE WEATHER POTENTIAL. ANTECEDENT CONDITIONS ARE NOT TREMENDOUSLY WET OVER THE EASTERN CAROLINAS: TS BERYL BROUGHT OUR LAST SIGNIFICANT RAINFALL EVENT OVER 10 DAYS AGO AND ONE-WEEK RAINFALL (NOT COUNTING TODAY) IS ONLY 5-25% OF NORMAL. FLOODING POTENTIAL IS NOT QUITE HIGH ENOUGH FOR A FLOOD WATCH AT THIS TIME...BUT WE WILL CONTINUE THE MENTION OF LOCALIZED FLOODING IN THE HAZARDOUS WEATHER OUTLOOK. THE 500 MB TROUGH SHOULD EASE ITS WAY TO THE COAST WEDNESDAY AFTERNOON WITH DRIER MID-LEVEL AIR (1.50 INCH PW) ADVECTING IN ON LIGHT NW/N WINDS ALOFT DURING THE DAY. THIS IS NEARLY THE SAME TIMING OF THE SURFACE COLD FRONT AS WELL. THIS SHOULD LEAD TO GRADUALLY DIMINISHING POPS WITH THE HIGHEST CHANCES OF SHOWERS AND STORMS WEDNESDAY ALONG THE COAST. THE GFS IS MUCH MORE BULLISH DEVELOPING SYNOPTIC LOW PRESSURE ALONG THE FRONT WEDNESDAY NIGHT WHICH WOULD BRING A SOMEWHAT STRONGER NE SURGE DOWN THE COAST WITH DRIER AND COOLER AIR PENETRATING FARTHER SOUTH INTO SOUTH CAROLINA. DIURNAL TEMPERATURE RANGES WILL BE RESTRICTED TUESDAY DUE TO CLOUDS AND RATHER WIDESPREAD SHOWER ACTIVITY. HIGH TEMPERATURES SHOULD BRIEFLY REACH 84-85 DEGREES ALTHOUGH THIS MIGHT BE FOR ONLY A FEW MINUTES IN BREAKS BETWEEN SHOWERS. AFTER A HUMID TUESDAY NIGHT WITH LOWS 69-73...SOMEWHAT DRIER CONDITIONS WEDNESDAY WILL ALLOW HIGHS INLAND TO REACH THE UPPER 80S. LOWS WEDNESDAY NIGHT SHOULD FALL TO 67-71...ALTHOUGH STRONGER COLD ADVECTION BEHIND OFFSHORE LOW PRESSURE AS ADVERTISED BY THE 12Z GFS COULD BRING SLIGHTLY COOLER READINGS. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 300 PM MONDAY...MEDIUM RANGE GUIDANCE CONTINUES TO ADVERTISE THE MID LEVEL PATTERN DEVELOPING INTO A OMEGA CONFIGURATION FOR THE WEEKEND. AT THE SURFACE...HIGH PRESSURE WILL BE THE FEATURE OF FOCUS FOR OUR AREA WITH THE RIDGE AXIS ALIGNED ALONG THE APPALACHIANS AS LOW PRESSURE REMAINS WELL OFFSHORE. THURSDAY AND FRIDAY SHOULD BE DRY. IT APPEARS ENOUGH MOISTURE POOLING OCCURS SATURDAY THROUGH MONDAY TO WARRANT NORTHEAST RESULTANT SEA BREEZE POPS. OPERATIONAL GFS/MEX NUMBERS ARE QUITE COOL AND OPTED FOR SLIGHTLY MODIFIED/WARMER HIGHS AND OVERNIGHT LOWS. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 18Z...AIRMASS VERY JUICY WITH PRECIPITABLE WATER VALUES AROUND TWO INCHES. THIS CREATES MODERATE UNCERTAINTY WITH RESPECT TO TIMING OF CONVECTION. THE HRRR MODEL DID NOT INITIALIZE WELL WITH THE PRECIP OVER SOUTHEASTERN NORTH CAROLINA...SO IT MAY NOT HOLD WEIGHT FOR ACTIVITY THIS AFTERNOON. NEVERTHELESS...IT SHOWS AN AREA OF ACTIVE CONVECTION MOVING THROUGH THE CWA FROM WEST TO EAST THIS AFTERNOON...WEAKENING FOR DIURNAL REASONS AS IT NEARS THE COAST. VISIBILITIES COULD BRIEFLY GO DOWN TO IFR IN THE BRIEF HEAVY RAIN. OVERNIGHT...EXPECT CONVECTION TO WANE...BUT COULD NOT RULE OUT A SHOWER AT NEARLY ANY TIME. CEILINGS WILL REMAIN MVFR FOR THE MOST PART BUT COULD GO IFR INLAND TOWARD MORNING. TUESDAY...A FRONTAL BOUNDARY APPROACHES FROM THE WEST AS WELL AS A PRE FRONTAL TROUGH. CONVECTION IS EXPECTED...MAINLY FROM LATE MORNING ON. EXTENDED OUTLOOK...CHANCE FOR THUNDERSTORMS/IFR TUESDAY AFTERNOON THROUGH WEDNESDAY MORNING. OTHERWISE EXPECT VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM MONDAY...HIGH PRESSURE MAINTAINS ITS PRESENCE OFF THE SOUTHEAST COAST THROUGH THE PERIOD ALTHOUGH IT IS A FAIRLY WEAK HIGH...ITS MAIN CENTER OFF THE COAST OF NEW ENGLAND AND NOVA SCOTIA. A PIEDMONT TROUGH WILL GRADUALLY DEVELOP DURING THE NEAR TERM HOWEVER AND ADD A FEW KNOTS OF WIND SPEED TO THE FCST. THIS BUMP IN WINDS PAIRED WITH THE SLIGHT INC IN SE SWELL ENERGY WILL YIELD A FORECAST OF 2 OR 3 TO 4 FT FORECAST FOR ALL ZONES. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 PM MONDAY...MODERATE SOUTH-SOUTHWEST WINDS ARE EXPECTED TUESDAY IN ADVANCE OF A COLD FRONT THAT WILL MAKE ITS WAY TO THE BEACHES DURING THE DAY WEDNESDAY. SLOW-MOVING HEAVY SHOWERS AND ISOLATED TSTMS WILL BE THE MAIN WEATHER STORY AHEAD OF THIS FRONT. ALTHOUGH IT IS ALWAYS DIFFICULT TO PREDICT WHERE BATCHES OF CONVECTION WILL BE MORE THAN A FEW HOURS IN THE FUTURE...MODEL TRENDS HINT AT THE BEST CHANCES ACROSS THE COASTAL WATERS TUESDAY MORNING...WITH PERHAPS A SECOND MAXIMUM IN COVERAGE LATE TUESDAY NIGHT. ONCE THE FRONT PUSHES OFFSHORE WEDNESDAY AFTERNOON WINDS WILL TURN NORTHEASTERLY...WITH CONSIDERABLE MODEL DISAGREEMENT CONCERNING WHETHER A NORTHEAST SURGE DEVELOPS WITH LOW PRESSURE DEVELOPING ALONG THE FRONT OFFSHORE. FOR NOW WE HAVE ONLY INCREASED FORECAST WIND SPEEDS INTO THE 10-15 KT RANGE...BUT THE 12Z GFS WOULD IMPLY SPEEDS IN THE 15-20 KT RANGE WEDNESDAY NIGHT...BUT STRONGER THAN THE 12Z NAM MODEL. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 300 PM MONDAY...NORTHEASTERLY FLOW WILL PREVAIL THROUGH THE PERIOD AS SURFACE HIGH PRESSURE AXIS IS SITUATED ALONG THE APPALACHIANS. WIND SPEEDS WILL HOVER IN A RANGE OF 10-15 KNOTS PROBABLY CLOSER TO THE LOWER RANGE MOST OF THE TIME. CAVEAT TO THE FORECAST WITH THIS TYPE OF SYNOPTIC SCENARIO IS THE EMBEDDED NUMEROUS SURGES WHICH ARE ALL BUT IMPOSSIBLE TO RECONCILE THIS FAR OUT IN TIME. SEAS WILL HOVER IN A RANGE OF 2-4 FEET THURSDAY AND FRIDAY INCREASING TO 3-5 FEET AND POSSIBLY HIGHER INTO FLAG CRITERIA SATURDAY AS THE FETCH PERSISTS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...TRA NEAR TERM...MBB SHORT TERM...TRA LONG TERM...SHK AVIATION...MBB/DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
140 PM EDT MON JUN 11 2012 .SYNOPSIS... SHOWERS AND THUNDERSTORMS WITH TORRENTIAL DOWNPOURS WILL BE ON THE INCREASE INTO WEDNESDAY AS TROPICAL MOISTURE FEEDS NORTH AHEAD OF A SLOW-MOVING COLD FRONT. THIS FRONT WILL MOVE ACROSS THE AREA ON WEDNESDAY. HIGH PRESSURE WILL BUILD DOWN FROM THE GREAT LAKES THURSDAY AND PERSIST THROUGH THE WEEKEND AS LOW PRESSURE DEVELOPS OFF THE COAST OF CAPE HATTERAS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM WEDNESDAY...NOT MUCH TO CHANGE AT THIS POINT...JUST TRYING TO PIN DOWN BEST LOCATION AND TIMING OF PRECIP CHANCES. AGREE WITH PREV FCST THAT MAIN AREA OF RAINFALL WILL MOVE IN FROM THE WEST...THE BAND OF SHOWERS CURRENTLY CROSSING THE SAVANNAH RIVER. A FEW SMALLER SCALE BANDS OF SHALLOW CONVECTION HAVE BROKEN OUT ALONG APPARENT DIFFERENTIAL HEATING BOUNDARIES...AND THERE IS NO REASON TO THINK THAT THEY WILL NOT CONTINUE. SUCH FEATURES WILL BE TOUGH TO TIME BUT ALSO NOT LEAD TO VERY APPRECIABLE PRECIP AMOUNTS. PREVIOUS DISCUSSION... AS OF 6 AM MONDAY...A TROPICAL MOISTURE FEED EXTENDING FROM NEAR THE BAY OF CAMPECHE AND UP THROUGH THE SOUTHEASTERN STATES WILL INCREASE THE PROBABILITY OF SHOWERS AND THUNDERSTORMS AND HEAVY DOWNPOURS THIS PERIOD AS A MID-LEVEL RIDGE SLOWLY EXITS THE EASTERN CAROLINAS AND A SLOW MOVING TROUGH TO OUR W CONTINUES TO APPROACH. PRECIPITABLE WATER VALUES WILL TOP 2 INCHES AS SSW TO SW LOW LEVEL JET INCREASES TO 25 TO 30 KT...HIGHEST INLAND FROM THE COAST. MODEST ISENTROPIC UPGLIDE WILL REMAIN THROUGH THE PERIOD. A WEAK MID-LEVEL SHORTWAVE TROUGH WILL ADD LIFT AS IT APPROACHES FROM THE SW LATE TONIGHT. HARD TO RULE OUT PRECIPITATION AT ANY POINT THIS PERIOD. WILL TREND POPS HIGHER THROUGH THE DAY AND ESPECIALLY TONIGHT AS LOW LEVEL JETTING AND LIFT INCREASES. THE POTENTIAL FOR SIGNIFICANT RAINFALL IS THERE GIVEN THE DEEP... NEARLY SATURATED LAYER THAT DEVELOPS FROM NEAR THE SURFACE THROUGH 20 KFT...MOST PRONOUNCED INLAND. THIS WILL BE ESPECIALLY TRUE LATE IN THE PERIOD SHOULD CELLS BEGIN TO TRAIN OVER THE SAME GENERAL AREA. AT THIS TIME...HIGHEST QPF VALUES THIS PERIOD ARE EXPECTED NEAR THE I-95 CORRIDOR WHERE AMOUNTS COULD REACH 1 TO 2 INCHES. AS YOU NEAR THE COAST...AMOUNTS SHOULD GENERALLY BE LOWER...ESPECIALLY ACROSS THE CAPE FEAR REGION WHERE RIDGING WILL ACQUIESCE LAST AND AS A RESULT POPS WILL BE LOWEST. DIURNAL RANGE SHOULD BE LIMITED DUE TO DEEP MOISTURE AND ABUNDANCE OF CLOUD COVER. HIGHS WILL BE ABOUT TO SLIGHTLY BELOW NORMAL. LOWS WILL BE ABOVE NORMAL...LOWER TO MID 70S. IT WILL FEEL RATHER HUMID THROUGH THE PERIOD WITH DEWPOINTS AS HIGH AS THE LOWER 70S. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 AM MONDAY... DEEP MOIST SOUTHERLY FLOW WILL BE IN PLACE ON TUESDAY AHEAD OF AN APPROACHING COLD FRONT. MEANWHILE SHORTWAVE TROUGH TRACKING UP FROM THE GULF COAST WILL MOVE EAST ACROSS THE CAROLINAS TUES INTO WED AS A NORTHERN STREAM TROUGH PUSHES THIS COLD FRONT EAST INTO AND THROUGH THE COASTAL CAROLINAS WED. THE H5 TROUGH WILL PROVIDE ENHANCED SUPPORT FOR SHWR/TSTM ACTIVITY IN A MOIST AND UNSTABLE ENVIRONMENT. GFS/NAM SHOWING BEST LIFT AND MOISTURE TUES AFTN THROUGH TUES NIGHT AND SHIFTING OFF THE COAST BY WED AFTN. PCP WATER VALUES INCREASE UP TO 2.25 INCHES AHEAD AND ALONG COLD FRONT TUES AFTN THROUGH TUES NIGHT. GFS SHOWS MORE OF A CLEAN PASSAGE OF FRONT EARLY WED BUT NAM SHOWS SEA BREEZE KICKING IN ON WED WITH MOISTURE LINGERING ALONG THE COAST AND HOLDING OFF FROPA UNTIL LATER IN THE DAY. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 3 AM MONDAY...MODELS CONTINUE TO SHOW DEVELOPING LOW PRESSURE OFF THE HATTERAS COAST ON THURS. THIS MAY HELP TO THROW AROUND SOME MOISTURE ON BACK END...BUT OVERALL EXPECT DRIER HIGH PRESSURE TO BUILD DOWN FROM THE GREAT LAKES INTO THE CAROLINAS THURS THROUGH THE WEEKEND. IN THE MID TO UPPER LEVELS...H5 RIDGE BUILDS UP THROUGH THE GREAT LAKES HEADING INTO THE WEEKEND WHILE MID TO UPPER TROUGH MAY DIG SOUTHWESTWARD FROM THE ATLANTIC WATERS PRODUCING SOME UNCERTAINTY OVER THE WEEKEND. FOR NOW WILL SHOW DRIER AIR BUILDING IN FOR THURS BUT WILL ADD SOME LOW END POPS BACK IN FORECAST MAINLY OVER COASTAL WATERS AND JUST ALONG THE COAST FRI THROUGH THE WEEKEND DUE TO UNCERTAINTY WITH THIS LOW. TEMPS WILL RUN INTO THE 80S DURING THE DAY AND IN THE 60S AT NIGHT. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 18Z...AIRMASS VERY JUICY WITH PRECIPITABLE WATER VALUES AROUND TWO INCHES. THIS CREATES MODERATE UNCERTAINTY WITH RESPECT TO TIMING OF CONVECTION. THE HRRR MODEL DID NOT INITIALIZE WELL WITH THE PRECIP OVER SOUTHEASTERN NORTH CAROLINA...SO IT MAY NOT HOLD WEIGHT FOR ACTIVITY THIS AFTERNOON. NEVERTHELESS...IT SHOWS AN AREA OF ACTIVE CONVECTION MOVING THROUGH THE CWA FROM WEST TO EAST THIS AFTERNOON...WEAKENING FOR DIURNAL REASONS AS IT NEARS THE COAST. VISIBILITIES COULD BRIEFLY GO DOWN TO IFR IN THE BRIEF HEAVY RAIN. OVERNIGHT...EXPECT CONVECTION TO WANE...BUT COULD NOT RULE OUT A SHOWER AT NEARLY ANY TIME. CEILINGS WILL REMAIN MVFR FOR THE MOST PART BUT COULD GO IFR INLAND TOWARD MORNING. TUESDAY...A FRONTAL BOUNDARY APPROACHES FROM THE WEST AS WELL AS A PRE FRONTAL TROUGH. CONVECTION IS EXPECTED...MAINLY FROM LATE MORNING ON. EXTENDED OUTLOOK...CHANCE FOR THUNDERSTORMS/IFR TUESDAY AFTERNOON THROUGH WEDNESDAY MORNING. OTHERWISE EXPECT VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM MONDAY...FAIRLY STEAD SET OF CONDITIONS THROUGH THE DAY TO BRING QUIET WEATHER FOR THE MOST PART. SOME LOW LEVEL JETTING WILL DEVELOP OVER THE LANDMASS...THE COASTAL WATERS WILL BE ON THE EASTERN PERIPHERY OF THIS JET LEADING TO A FEW KTS INCREASE IN SSWRLY FLOW. SEAS 2.5 TO 3 FT AT THE BUOYS WITH PEAK PD AT 5 SEC. A SMALL 10 SEC SWELL SHOWING UP AS WELL. BOTH WAVE COMPONENTS WILL CONTINUE AS-IS THROUGH THE PERIOD. PREVIOUS DISCUSSION... AS OF 6 AM MONDAY...A SOUTH TO SSW FLOW WILL REMAIN ACROSS THE WATERS AHEAD OF A SLOW MOVING TROUGH APPROACHING FROM THE W. LOW LEVEL JETTING THIS PERIOD WILL BE STRONGEST LATE TONIGHT WHEN WINDS COULD REACH 15 TO 20 KT. SEAS WILL HOLD IN THE 2 TO 4 FT RANGE THROUGH THE DAY WITH PERHAPS SOME 5 FOOTERS CREEPING INTO THE OUTERMOST WATERS LATE TONIGHT AS WINDS BEGIN TO INCREASE. A 9 TO 10 SECOND SE SWELL WILL PERSIST THROUGH THE PERIOD. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 AM MONDAY...GRADIENT TIGHTENS AS COLD FRONT MOVES THROUGH THE CAROLINAS TUES INTO WED. SOUTHERLY WINDS WILL REACH UP TO 20 KTS AHEAD OF THE FRONT. THIS WILL PUSH SEAS UP TO 3 TO 5 FT LATE TUES. THE COLD FRONT SHOULD CLEAR THE COASTAL WATERS ON WED WITH NORTHERLY FLOW DEVELOPING BEHIND IT. THE DIMINISHING OFF SHORE FLOW WILL ALLOW SEAS TO RELAX DOWN TO 3 FT OR LESS BY WED NIGHT. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 3 AM MONDAY...LIGHT NORTHERLY FLOW AROUND 10 TO 15 KTS ON THURSDAY MAY INCREASE UP TO 15 TO 20 KTS ON FRIDAY AS GRADIENT TIGHTENS BETWEEN HIGH PRESSURE BUILDING DOWN FROM THE GREAT LAKES AND LOW PRESSURE DEVELOPING OFF THE HATTERAS COAST. SEAS MAY INCREASE UP TO 4 TO 5 FT IN THE OUTER WATERS FRI INTO TE WEEKEND AND POSSIBLY HIGHER IF LOW PRESSURE DEEPENS OFF THE COAST. THERE IS SOME UNCERTAINTY AS TO THE STRENGTH AND LOCATION OF THIS DEVELOPING LOW PRESSURE OFF THE CAROLINA COAST HEADING INTO THE WEEKEND AND THEREFORE WILL REMAIN MORE CONSERVATIVE WITH SEA HEIGHTS FOR NOW. WNA MODEL SHOWS SEAS SHOOTING UP ON FRI TO NEAR SCA THRESHOLDS IN OUTER WATERS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...MBB SHORT TERM...RGZ LONG TERM...RGZ AVIATION...43
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
342 PM EDT MON JUN 11 2012 .SYNOPSIS... A COLD FRONT WILL MOVE ACROSS THE FORECAST AREA LATE TONIGHT AND TUESDAY MORNING. HIGH PRESSURE WILL BUILD IN OVER THE GREAT LAKES WEDNESDAY AND THEN MOVE SLOWLY EAST THROUGH THE REST OF THE WORK WEEK. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... A VERY TOUGH FORECAST MAINLY TO DO WITH THE COVERAGE. SOME LIGHT SHOWERS WILL EXIT THE NORTHEAST PORTION OF THE FORECAST AREA THIS EVENING. SOME OF THE MODELS TRY TO INDICATE MORE SHOWERS AND THUNDERSTORMS DEVELOPING OVER THE EXTREME EASTERN PORTION OF THE FORECAST AREA LATE THIS EVENING. WENT ALONG WITH THAT BUT VERY MUCH ON THE EDGE. FOR NORTHWEST OHIO...SOME SHOWERS AND THUNDERSTORMS DEVELOPING OVER SOUTHWEST OHIO THAT WILL MOVE NORTHEAST THIS EVENING. THE MCS OVER MISSOURI AND ILLINOIS DOESN`T SEEM LIKE IT WILL BE A PROBLEM FOR THE AREA. THE HRRR TRIES TO DEVELOP THIS...WHICH MAY BE OK WITH A SHORT WAVE MOVING ACROSS THE REGION TONIGHT WITH THE COLD FRONT. ON THE EDGE ABOUT HOW MUCH THUNDER ACTIVITY WILL OCCUR WITH THE AIRMASS NOT THAT UNSTABLE. QPF AMOUNTS SHOULD NOT BE THAT HIGH...WILL HAVE TO WATCH ANY SLOW MOVING CONVECTION. WENT TOWARD THE WARMER GUIDANCE FOR LOWS BECAUSE OF CLOUDS AND NOT WIDESPREAD PRECIPITATION. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/... ON THE EDGE HOW MUCH ACTIVITY WILL OCCUR TUESDAY WITH THE FRONT MOVING THROUGH BY EARLY AFTERNOON. FOLLOWED PREVIOUS FORECAST WHICH SEEMED REASONABLE. CLOUDS SHOULD DECREASE FROM THE WEST. OTHERWISE HIGH PRESSURE BUILDING IN FOR THE REMAINDER OF THE PERIOD. THE LAKE AND 850 MB TEMPERATURE DIFFERENCE SHOULD NOT BE THAT EXTREME TO CAUSE LAKE EFFECT OR LAKE INDUCED CLOUDS... EXCEPT MAY BE AROUND DAYBREAK WEDNESDAY WHEN THE DIFFERENCE WILL BE NEAR 10 C. USED A BLEND OF GUIDANCE FOR THE LOWS AND HIGHS. TENDED TOWARD COOLER ESPECIALLY FOR NIGHT TIME READINGS. && .LONG TERM /FRIDAY THROUGH MONDAY/... FOR THOSE WANTING RAIN...THIS IS NOT A GOOD LONG TERM FORECAST. RIDGE REMAINS NEARLY STATIONARY OVER THE REGION. MUCH OF THE HEAT WILL BE TO OUR WEST THROUGH THE WEEKEND SO OUR TEMPERATURES SHOULD BE IN THE 80S. POSSIBLY A LITTLE WARMER EARLY NEXT WEEK IF THE RIDGE SHIFTS A LITTLE MORE EAST. HAVE GONE A FEW DEGREES ABOVE GUIDANCE SINCE LATELY WE HAVE BEEN WARMING BETTER THAN THE CLIMO WEIGHTED GUIDANCE IS SUGGESTING. WE ARE GETTING DRIER AND WE HAVE A LONG JUNE DAY TO WARM. AFTERNOON POP-UP SHOWER/TS CHANCES DO NOT EVEN LOOK THAT GOOD. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... LIGHT SHOWERS SLOW TO MOVE INTO CENTRAL AND EASTERN PORTIONS OF THE AREA...BUT THEY WILL. MVFR CEILINGS ASSOCIATED WITH THESE SHOWERS. CU HAVE GOTTEN A LITTLE BUBBLY OVER INDIANA AND TOL/FDY MAY SEE AN ISOLATED TS AROUND THIS AFTERNOON. A LOT OF QUESTION AS TO WHAT WILL DEVELOP THIS EVENING/OVERNIGHT. WILL STILL HAVE A CHANCE OF SOME EMBEDDED TS AND SCATTERED SHOWERS WITH THE COLD FRONT MAKING ITS WAY ACROSS THE AREA TOWARD SUNRISE/EARLY MORNING. SOME GUIDANCE IS WANTING TO GO AS LOW AS IFR WITH VSBY AND/OR CIGS OVERNIGHT. NOT SURE SO HAVE GONE WITH A MORE CONSERVATIVE MVFR OVERNIGHT. CLEARING TUESDAY MORNING/EARLY AFTERNOON. SOUTH FLOW THROUGH TONIGHT...WEST-NORTHWEST TUESDAY AFTER THE FRONT. .OUTLOOK...NON VFR...NONE. && .MARINE... LAKE LOOKS LIKE IT WILL GET MIXED UP OVER THE NEXT FEW DAYS AS COLD AIR ADVECTION NORTHERLY FLOW DEVELOPS. LOOKING AT POSSIBLE SMALL CRAFT ADVISORIES BY TUESDAY NIGHT. THE EVENT WILL BE SHORT LIVED AS WINDS BEGIN TO DIMINISH ON WEDNESDAY. HIGH PRESSURE FINALLY BECOMES STATIONARY OVER THE EAST COAST AND SETS UP A LIGHT SOUTHERLY COMPONENT TO THE WIND. GENERALLY LIGHT FLOW IS EXPECTED THROUGH THE REST OF THE PERIOD. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KIELTYKA NEAR TERM...KIELTYKA SHORT TERM...KIELTYKA LONG TERM...OUDEMAN AVIATION...OUDEMAN MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS NORMAN OK
428 PM CDT MON JUN 11 2012 .DISCUSSION... THE BIGGEST CHALLENGES ARE SEVERE THUNDERSTORM AND RAIN CHANCES THROUGH WEDNESDAY. THROUGH 10 PM CDT TONIGHT...BELIEVE THE BEST CHANCES FOR SEVERE STORMS WILL OVER WESTERN NORTH TEXAS AND POSSIBLY FAR SOUTHERN OKLAHOMA NEAR A SURFACE BOUNDARY...WHERE KEPT 20/30 PERCENT CHANCES. STORMS WERE DEVELOPING NEAR ABILENE TEXAS WHERE THE CAP HAS BEEN BROKEN AND WILL MOVE EAST AND POSSIBLY NORTHEAST. WITH THE AIR BEING UNSTABLE WITH SOME SHEAR...THINK LARGE HAIL...POSSIBLY AS LARGE AS BASEBALLS...AND DAMAGING WIND OF 65 MPH OR GREATER WILL BE THE MAIN HAZARDS. MOST OF THESE STORMS WILL STAY SOUTH OF THE FORECAST AREA. NOTICED THE LATEST HRRR RUNS INDICATED ISOLATED DEVELOPMENT EAST OF I-35...SO KEPT 20 PERCENT IN THESE AREAS...THOUGH CONFIDENCE OF DEVELOPMENT REMAINS QUITE LOW DUE TO STRONG CAPPING. AFTER 10 PM CDT TONIGHT...KEPT RAIN CHANCES SOUTH OF A CLINTON TO OKLAHOMA CITY TO SWEETWATER LINE. ADDITIONAL STORMS MAY DEVELOP NEAR THE LINE MENTIONED ABOVE BETWEEN 10 PM AND 4 AM AS LATEST MODELS INDICATED THE MID LEVEL CAP WEAKENING WITH 700 MB TEMPERATURES COOLING TO +9/10C. WITH ABUNDANT INSTABILITY AND A GOOD AMOUNT OF SHEAR...A FEW STORMS MAY BE SEVERE WITH LARGE HAIL...POSSIBLY VERY LARGE...AND DAMAGING WIND. THE FOCUS FOR LIFT APPEARS TO BE WEAK...SO WIDESPREAD SEVERE SEEMS UNLIKELY. LOCALLY HEAVY RAINFALL MAY BE POSSIBLE AS WELL. TUESDAY...KEPT RAIN CHANCES ACROSS MUCH OF THE AREA WITH THE HIGHEST CHANCES OVER SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS WHERE BEST MOISTURE AND INSTABILITY ARE FORECAST. SOME STORMS MAY BE SEVERE WITH LARGE HAIL AND DAMAGING WIND...MAINLY DURING THE LATE AFTERNOON AND EVENING HOURS...THOUGH LARGE HAIL THREAT MAY BE LOWER COMPARED TO TONIGHT. WEDNESDAY INTO THURSDAY...KEPT LOWER CHANCES FOR SHOWERS AND STORMS OVER THE AREA. CANNOT RULE OUT A FEW SEVERE STORMS BOTH DAYS. FRIDAY THROUGH NEXT MONDAY...HOTTER AND DRIER WEATHER IS EXPECTED. A FEW STORMS MAY BE POSSIBLE DURING THIS TIME FRAME...BUT DID NOT MENTION DUE TO LOW CONFIDENCE. MBS && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 68 85 66 86 / 20 20 40 30 HOBART OK 64 87 67 89 / 20 40 40 30 WICHITA FALLS TX 69 88 71 91 / 40 30 50 30 GAGE OK 55 84 62 88 / 0 20 40 30 PONCA CITY OK 60 86 61 86 / 0 0 20 30 DURANT OK 71 87 70 88 / 50 30 40 30 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 02/17
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
401 PM EDT MON JUN 11 2012 .SYNOPSIS... A FRONTAL SYSTEM WILL APPROACH FROM THE WEST AND GENERATE WIDESPREAD SHOWERS AND THUNDERSTORMS FOR LATE TONIGHT AND TUESDAY. THE COLD FRONT WILL PASS THROUGH TUESDAY NIGHT. THIS FRONT MAY STALL OUT NEAR THE MID ATLANTIC COAST FOR THE MIDDLE AND LATTER PART OF THIS WEEK DELAYING THE EXIT OF CLOUDS AND SHOWERS OUT OF THE EASTERN HALF OF PENNSYLVANIA. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... MSTR ALOFT IS THICKENING UP AND DIURNAL CU IS FORMING/FILLING IN. THE LOW CRUD IN THE EAST IS GONE. THICKER LINE OF CU FORMING FROM YORK TO STATE COLLEGE COULD MAKE ISOLD SHRA BEFORE SUNSET. THE MESO MDLS LIKE THE HRRR AND RUC DO GENERATE SOME RAINFALL THROUGH THE CONVECTIVE PARAM. SHOWERS ALSO MOVING THRU FAR WRN PA HAVE A DISTINCT LACK OF LTG DESPITE LOW STABILITY. EXPECT THESE SHOWERS TO SLIDE TO THE WEST AND AFFECT THE FAR WRN ZONES THIS EVENING. RAIN WILL NOT BE HEAVY AT ALL...WITH JUST A TENTH OR SO BEFORE MIDNIGHT. WILL STILL MENTION SLIGHT CHC T FOR THE REGION WITH STABILITY LOW. MOST OF THE PRECIP WILL WAIT UNTIL AFTER MIDNIGHT WHEN THE HEIGHTS START TO DROP FASTER. PWATS CLIMB MORE THAN AN INCH THRU SUNRISE AND THE MDL SOUNDINGS DECIDEDLY MOIST-ADIABATIC FOR LATER TONIGHT...SO HEAVY RAIN FROM ANY CONVECTION IS POSSIBLE. SKY COVER WILL BECOME 100PCT THIS EVENING AND EARLY TONIGHT. THUS...TEMPS SHOULD NOT FALL FAR BELOW THE MID 60S. FFG AND FFH NUMBERS ARE PRETTY LOFTY - ON THE ORDER OF 2.5 TO 3.5 INCHES IN 3 HRS...SO IT WOULD NEED TO BE MUCH HEAVIER RAIN THAN EXPECTED TO CREATE FLOODING PROBLEMS. THE DURATION OF THE EVENT AND PROGRESSIVE NATURE OF THE TROUGH AND FRONT ARGUE AGAINST ANY FLOOD WATCHES. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... CATEGORICAL POPS ARE STILL IN ORDER THROUGH ALL OF TUESDAY AND INTO TUESDAY EVENING. STABLE PRECIP SHOULD DOMINATE OVER CONVECTIVE FORCING. LLJET IS NOT STRONG AT ALL. SHEAR ALSO ONLY WEAK TO MODERATE. HOWEVER...SPC DOES MENTION THE AREA IN THE DAY2 OUTLOOK. WILL KEEP THE MENTION OF THUNDER IN BUT FOREGO MENTIONS OF GUSTY WINDS OR HAIL. I THINK IT WILL BE HARD TO GET THE CLOUDS OUT OF THE WAY LONG ENOUGH AND MATCH UP THE TIMING OF UPPER FORCING OR THE COLD FRONT WITH THAT POSSIBLE WINDOW OF STRONGER SFC HEATING AND DESTABILIZATION. THE HIGH PRECIP WATER WILL NOT BE TAPPED VERY EFFECTIVELY WITHOUT WIDESPREAD UPRIGHT CONVECTION TO TAP INTO IT. OVERALL...A GENERAL 1 INCH OF PRECIP IS LOOKING LIKE THE STORM TOTAL. EXPECT SLIGHTLY LOWER AMOUNTS TO THE WEST AND HIGHER AMOUNTS IN THE EAST. AGAIN...THOSE AMOUNTS SHOULD NOT RAISE EYEBROWS WITH VEGETATION FULLY GROWN AND STREAM FLOWS AROUND NORMAL. TIMING OF THE FROPA LOOKS LIKE IT WILL BE A BIT QUICKER THAN PREV FCSTS...WITH WINDS SHIFTING TO THE WEST LATE TUES AFTN IN THE WEST AND IN THE EAST BY MIDNIGHT. THUS...WILL KEEP POPS HIGH FOR THE DAYLIGHT HRS...BUT TAPER THEM OFF COMPLETELY FROM WEST TO EAST BEFORE SUNRISE WED. THE FRONT ITSELF WILL HANG BACK BEHIND THE MAIN SHIELD OF PRECIP AND GENERATE SOME LOW-TOPPED SHOWERS AS IT MOVES THROUGH. MAXES WILL BE IN THE 70S OVERALL WITHOUT SIG BREAKS IN THE SKY COVER. DRY AIR FINALLY WORKS IN TO THE WEST TUES NIGHT AS THE STRONGEST SHORT WAVE PUSHES THROUGH. CLEARING - IN THE WEST AT LEAST - MAY ALLOW FOG TO FORM AS TEMPS DIP CLOSE TO 50 IN THE WRN MTS AND MID 50S TO NEAR 60 IN THE CENTRAL AND EAST. BUT WIND AND DRYING AIRMASS MAY NEGATE THAT AS WELL. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... THE CFRONTAL BOUNDARY WILL HAVE PUSHED THE DEEP MOISTURE EAST OF THE AREA TO BEGIN THE PERIOD. HOWEVER...AN UPPER LOW FCST TO CUT- OFF OVER THE NORTH ATLANTIC /FOLLOWED BY A DEVELOPING REX BLOCK/ MAY HOLD THE BOUNDARY/TROFFINESS ALONG THE MID ATLANTIC SEABOARD FOR SEVERAL DAYS MORE. THIS WILL KEEP AT LEAST A LOW POTENTIAL FOR SOME SHOWERS AND COOLER TEMPERATURES ACROSS THE EASTERN PARTS OF CENTRAL PA...AS A SLIGHTLY ANOMALOUS LLVL EASTERLY FLOW DEVELOPS THURSDAY INTO FRIDAY WITH THE CENTER OF HIGH PRESSURE SLIDING BY ACROSS SRN ONTARIO. LATEST LONG TERM GUIDANCE HAS FLOPPED BACK TO A DRIER SOLUTION THAT WHAT WAS SHOWN YESTERDAY WITH REGARD CLOUDS/SHOWERS BEING SLOW TO CLEAR OVER EASTERN PA. HOWEVER...SOLUTIONS ARE NOT COMPLETELY DRY...THUS THIS APPEARS TO THE MAIN FORECAST PROBLEM IN THE LONG TERM PERIOD. UPPER RIDGING IS STILL FORECAST TO BUILD INTO THE MIDWEST/OHIO VALLEY LATE IN THE WEEK /LED SEVERAL HUNDRED KM BY A 1024 MB SFC HIGH/...LIKELY BRINGING ANOTHER SUMMER-LIKE PERIOD LATER IN THE EXTENDED. HOWEVER...WITH THE CENTER OF THE RIDGE SITUATED FROM THE MID MISS VALLEY TO LAKE MICHIGAN...AND SLOW RETROGRADE OF THE NORTH ATLC UPPER LOW...THERE IS STILL SOME UNCERTAINTY WITH RESPECT TO TEMPS...THE DISTRIBUTION OF CLOUD COVER...THE CHANCE FOR DIURNAL CONVECTION ACROSS THE EASTERN HALF OF PENN LATE IN THE WEEK AND INTO THE UPCOMING WEEKEND. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... CLOUDS WILL CONTINUE TO THICKEN AND LOWER INTO THIS EVENING...IN ADVANCE OF COLD FRONT APPROACHING FROM THE MIDWEST. AN UPPER LEVEL DISTURBANCE LIFTING NWD ALONG THE APPALACHIANS AND COULD TRIGGER ISOLD-SCT SHOWER OR TSTM OVER S/W PA THROUGH THIS EVE. THE MAIN UPPER TROUGH SWINGS ACROSS THE GREAT LAKES LATER TONIGHT INTO TUES...PUSHING THE COLD FRONT THROUGH CENTRAL PA. EXPECT SHRA TO INCREASE IN CVRG/INTENSITY AND SPREAD EASTWARD OVERNIGHT INTO TUES...BEFORE TAPERING OFF FROM WEST TO EAST TUES NGT. MOIST S-SE LOW LEVEL FLOW WILL SUPPORT LOW MVFR TO IFR CIGS...WITH VIS FLUCTUATIONS IN MOD TO OCNLY HVY SHRA/TSRA. ONCE THE FRONT PULLS EAST OF THE REGION...THE REMAINDER OF THE WEEK /WED-SAT/ LOOKS RELATIVELY QUIET AS HIGH PRESSURE BUILDS INTO THE NE UNITED STATES. OUTLOOK... WED-FRI...GENERALLY VFR. ISOLD SHRA/TSRA POSSIBLE EACH AFTN. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO/LAMBERT NEAR TERM...DANGELO SHORT TERM...DANGELO LONG TERM...LAMBERT/GARTNER AVIATION...EVANEGO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
241 PM EDT MON JUN 11 2012 .SYNOPSIS... A FRONTAL SYSTEM WILL APPROACH FROM THE WEST AND GENERATE WIDESPREAD SHOWERS AND THUNDERSTORMS FOR LATE TONIGHT AND TUESDAY. THE COLD FRONT WILL PASS THROUGH TUESDAY NIGHT. THIS FRONT MAY STALL OUT NEAR THE MID ATLANTIC COAST FOR THE MIDDLE AND LATTER PART OF THIS WEEK DELAYING THE EXIT OF CLOUDS AND SHOWERS OUT OF THE EASTERN HALF OF PENNSYLVANIA. && .NEAR TERM /THROUGH TONIGHT/... MSTR ALOFT IS THICKENING UP AND DIURNAL CU IS FORMING/FILLING IN. THE LOW CRUD IN THE EAST IS GONE. THICKER LINE OF CU FORMING FROM YORK TO STATE COLLEGE COULD MAKE ISOLD SHRA BEFORE SUNSET. THE MESO MDLS LIKE THE HRRR AND RUC DO GENERATE SOME RAINFALL THROUGH THE CONVECTIVE PARAM. SHOWERS ALSO MOVING THRU FAR WRN PA HAVE A DISTINCT LACK OF LTG DESPITE LOW STABILITY. EXPECT THESE SHOWERS TO SLIDE TO THE WEST AND AFFECT THE FAR WRN ZONES THIS EVENING. RAIN WILL NOT BE HEAVY AT ALL...WITH JUST A TENTH OR SO BEFORE MIDNIGHT. WILL STILL MENTION SLIGHT CHC T FOR THE REGION WITH STABILITY LOW. MOST OF THE PRECIP WILL WAIT UNTIL AFTER MIDNIGHT WHEN THE HEIGHTS START TO DROP FASTER. PWATS CLIMB MORE THAN AN INCH THRU SUNRISE AND THE MDL SOUNDINGS DECIDEDLY MOIST-ADIABATIC FOR LATER TONIGHT...SO HEAVY RAIN FROM ANY CONVECTION IS POSSIBLE. SKY COVER WILL BECOME 100PCT THIS EVENING AND EARLY TONIGHT. THUS...TEMPS SHOULD NOT FALL FAR BELOW THE MID 60S. FFG AND FFH NUMBERS ARE PRETTY LOFTY - ON THE ORDER OF 2.5 TO 3.5 INCHES IN 3 HRS...SO IT WOULD NEED TO BE MUCH HEAVIER RAIN THAN EXPECTED TO CREATE FLOODING PROBLEMS. THE DURATION OF THE EVENT AND PROGRESSIVE NATURE OF THE TROUGH AND FRONT ARGUE AGAINST ANY FLOOD WATCHES. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... CATEGORICAL POPS ARE STILL IN ORDER THROUGH ALL OF TUESDAY AND INTO TUESDAY EVENING. STABLE PRECIP SHOULD DOMINATE OVER CONVECTIVE FORCING. LLJET IS NOT STRONG AT ALL. SHEAR ALSO ONLY WEAK TO MODERATE. HOWEVER...SPC DOES MENTION THE AREA IN THE DAY2 OUTLOOK. WILL KEEP THE MENTION OF THUNDER IN BUT FOREGO MENTIONS OF GUSTY WINDS OR HAIL. I THINK IT WILL BE HARD TO GET THE CLOUDS OUT OF THE WAY LONG ENOUGH AND MATCH UP THE TIMING OF UPPER FORCING OR THE COLD FRONT WITH THAT POSSIBLE WINDOW OF STRONGER SFC HEATING AND DESTABILIZATION. THE HIGH PRECIP WATER WILL NOT BE TAPPED VERY EFFECTIVELY WITHOUT WIDESPREAD UPRIGHT CONVECTION TO TAP INTO IT. OVERALL...A GENERAL 1 INCH OF PRECIP IS LOOKING LIKE THE STORM TOTAL. EXPECT SLIGHTLY LOWER AMOUNTS TO THE WEST AND HIGHER AMOUNTS IN THE EAST. AGAIN...THOSE AMOUNTS SHOULD NOT RAISE EYEBROWS WITH VEGETATION FULLY GROWN AND STREAM FLOWS AROUND NORMAL. TIMING OF THE FROPA LOOKS LIKE IT WILL BE A BIT QUICKER THAN PREV FCSTS...WITH WINDS SHIFTING TO THE WEST LATE TUES AFTN IN THE WEST AND IN THE EAST BY MIDNIGHT. THUS...WILL KEEP POPS HIGH FOR THE DAYLIGHT HRS...BUT TAPER THEM OFF COMPLETELY FROM WEST TO EAST BEFORE SUNRISE WED. THE FRONT ITSELF WILL HANG BACK BEHIND THE MAIN SHIELD OF PRECIP AND GENERATE SOME LOW-TOPPED SHOWERS AS IT MOVES THROUGH. MAXES WILL BE IN THE 70S OVERALL WITHOUT SIG BREAKS IN THE SKY COVER. DRY AIR FINALLY WORKS IN TO THE WEST TUES NIGHT AS THE STRONGEST SHORT WAVE PUSHES THROUGH. CLEARING - IN THE WEST AT LEAST - MAY ALLOW FOG TO FORM AS TEMPS DIP CLOSE TO 50 IN THE WRN MTS AND MID 50S TO NEAR 60 IN THE CENTRAL AND EAST. BUT WIND AND DRYING AIRMASS MAY NEGATE THAT AS WELL. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... THE CFRONTAL BOUNDARY WILL HAVE PUSHED THE DEEP MOISTURE EAST OF THE AREA TO BEGIN THE PERIOD. HOWEVER...AN UPPER LOW FCST TO CUT-OFF OVER THE NORTH ATLANTIC /FOLLOWED BY A DEVELOPING REX BLOCK/ MAY HOLD THE BOUNDARY/TROFFINESS ALONG THE MID ATLANTIC SEABOARD FOR SEVERAL DAYS MORE. THIS WILL KEEP AT LEAST A LOW POTENTIAL FOR SOME SHOWERS AND COOLER TEMPERATURES ACROSS THE EASTERN PARTS OF CENTRAL PA...AS A SLIGHTLY ANOMALOUS LLVL EASTERLY FLOW DEVELOPS THURSDAY INTO FRIDAY WITH THE CENTER OF HIGH PRESSURE SLIDING BY ACROSS SRN ONTARIO. UPPER RIDGING IS STILL FORECAST TO BUILD INTO THE MIDWEST/OHIO VALLEY LATE IN THE WEEK /LED SEVERAL HUNDRED KM BY A 1024 MB SFC HIGH/...LIKELY BRINGING ANOTHER SUMMER-LIKE PERIOD LATER IN THE EXTENDED. HOWEVER...WITH THE CENTER OF THE RIDGE SITUATED FROM THE MID MISS VALLEY TO LAKE MICHIGAN...AND SLOW RETROGRADE OF THE NORTH ATLC UPPER LOW...THERE IS STILL SOME UNCERTAINTY WITH RESPECT TO TEMPS...THE DISTRIBUTION OF CLOUD COVER...THE THE CHC FOR DIURNAL CONVECTION ACROSS THE EASTERN HALF OF PENN LATE IN THE WEEK AND INTO THE UPCOMING WEEKEND. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... CLOUDS WILL CONTINUE TO THICKEN AND LOWER INTO THIS EVENING...IN ADVANCE OF COLD FRONT APPROACHING FROM THE MIDWEST. AN UPPER LEVEL DISTURBANCE LIFTING NWD ALONG THE APPALACHIANS AND COULD TRIGGER ISOLD-SCT SHOWER OR TSTM OVER S/W PA THROUGH THIS EVE. THE MAIN UPPER TROUGH SWINGS ACROSS THE GREAT LAKES LATER TONIGHT INTO TUES...PUSHING THE COLD FRONT THROUGH CENTRAL PA. EXPECT SHRA TO INCREASE IN CVRG/INTENSITY AND SPREAD EASTWARD OVERNIGHT INTO TUES...BEFORE TAPERING OFF FROM WEST TO EAST TUES NGT. MOIST S-SE LOW LEVEL FLOW WILL SUPPORT LOW MVFR TO IFR CIGS...WITH VIS FLUCTUATIONS IN MOD TO OCNLY HVY SHRA/TSRA. ONCE THE FRONT PULLS EAST OF THE REGION...THE REMAINDER OF THE WEEK /WED-SAT/ LOOKS RELATIVELY QUIET AS HIGH PRESSURE BUILDS INTO THE NE UNITED STATES. OUTLOOK... WED-FRI...GENERALLY VFR. ISOLD SHRA/TSRA POSSIBLE EACH AFTN. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO/LAMBERT NEAR TERM...DANGELO SHORT TERM...DANGELO LONG TERM...LAMBERT/GARTNER AVIATION...EVANEGO
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1255 PM CDT MON JUN 11 2012 .DISCUSSION... UPDATED FOR 18Z AVIATION DISCUSSION && .PREV DISCUSSION... /ISSUED 1115 AM CDT MON JUN 11 2012/ UPDATE... UPDATED FOR ANTICIPATED CONVECTION AND SEVERE THREAT. DISCUSSION... A FORWARD PROPAGATING MCS CONTINUES TO PROGRESS EAST-SOUTHEASTWARD ACROSS SOUTHERN MISSOURI. THIS MCS IS PROGRESSING ALONG THE NORTHEASTERN PERIPHERY OF STRONG ELEVATED MIXED LAYER (EML/CAP) OVER MUCH OF ARKANSAS. THIS CAPPING INVERSION WAS ALSO EVIDENT FROM THE 12Z KLZK SOUNDING. THE CAP WEAKENS WITH EASTWARD EXTENT AND THE LATEST STEERING FLOW SUGGESTS THAT THE MCS SHOULD MAKE A TURN MORE TOWARDS THE SOUTH AND INTO THE HEART OF THE MID SOUTH. THE ATMOSPHERE WILL BECOME STRONGLY UNSTABLE IN THE PRE-CONVECTIVE AIRMASS AHEAD OF THE MCS. MLCAPES SHOULD APPROACH OR EVEN EXCEED 4000 J/KG AS TEMPERATURES RISE TO NEAR 90 DEGREES WITH DEWPOINTS REMAINING IN THE LOWER TO MIDDLE 70S. IN ADDITION...STEEPENING MID LEVEL LAPSE RATES ON EDGE OF THE EML AROUND 7.0 C/KM AND LI/S BETWEEN -8C AND -12C SHOULD BE MORE THAN ENOUGH TO SUSTAIN CONVECTION AND ALLOW FOR THE POTENTIAL OF DAMAGING WINDS AND LARGE HAIL. CONVECTION SHOULD REMAIN ORGANIZED ALONG THE ADVANCING COLD POOL. ADDITIONAL CONVECTION MAY DEVELOP IN ADVANCE OF THE MCS AND WITH STRONG INSTABILITY AND WEAK CAPPING MAY ALSO POSE A SEVERE THREAT. PLAN TO EXPAND THE SLIGHT RISK AREAWIDE AND ADD MENTION OF SEVERE IN THE ZONES. ALSO POPS HAVE BEEN ADJUSTED TO REFLECT THE ANTICIPATED SITUATION. UPDATED ZONES AND GRIDS HAVE BEEN SENT AND THE HWO WILL BE UPDATED SHORTLY. JLH DISCUSSION... /ISSUED 449 AM CDT MON JUN 11 2012/ PRIMARY SHORT TERM FORECAST CONCERN REMAINS RAIN CHANCES. EARLY THIS MORNING... SHORTWAVE RIDGING WAS SPREADING INTO THE MIDSOUTH... IN THE WAKE OF AN UPPER LEVEL SHEAR AXIS THAT BROUGHT SCATTERED SHOWERS TO THE REGION ON SUNDAY. UPSTREAM OF THE SHORTWAVE RIDGE AXIS... A ROBUST LINEAR MCS WAS DROPPING SOUTHEAST THROUGH NW MISSOURI. 850/500MB THICKNESS ANALYSIS SUGGESTS THIS FEATURE MAY BEGIN A MORE SOUTHERLY PROPAGATION. KSGF VAD WIND PROFILER SHOWED 25KTS OF INFLOW...THOUGH THIS INFLOW SHOULD WEAKEN CONSIDERABLY FOLLOWING SUNRISE. AFTER A WEAKENING OF THE MO STORM COMPLEX... NAM MODEL REDEVELOPS STORMS OVER THE OZARK PLATEAU TOWARD MIDDAY. THIS APPEARS A REASONABLE SCENARIO...IN RESPONSE TO SURFACE HEATING... FALLING HEIGHTS AND INCREASING UPPER LEVEL DIFFLUENCE AHEAD OF A LONG WAVE TROF. SURFACED BASED INSTABILITY SHOULD BE IN GOOD SUPPLY ACROSS THE MIDSOUTH THIS AFTERNOON... WITH PARTIAL SUN AND LOWER 70S DEWPOINTS. DESPITE WEAK SHORTWAVE RIDGING...THE HIGH DEWPOINTS SHOULD MAKE CONVECTIVE TEMPS ATTAINABLE THIS AFTERNOON...ENOUGH TO WARRANT CHANCE POPS. MORE ORGANIZED CONVECTIVE ACTIVITY WILL BE POSSIBLE LATE THIS AFTERNOON AND EVENING. THE RIGHT ENTRANCE REGION OF AN UPPER JET CORE WILL INCREASE UPPER LEVEL DIFFLUENCE OVER THE MIDSOUTH... A PATTERN WHICH WILL WILL REMAIN RELATIVELY STATIC OVERNIGHT. THIS SUGGESTS ELEVATED STORMS MAY CONTINUE INTO THE OVERNIGHT... THROUGH MESOSCALE PROPAGATION PROCESSES WILL PLAY A LARGE ROLE ON WHERE STORMS OCCUR. A SURFACE COLD FRONT ARRIVES TUESDAY MORNING...BRINGING DRIER MIDCONTINENTAL AIR TO AREAS NORTH OF I40 BY AFTERNOON. 06Z NAM SUGGESTS THE FRONT MAY HANG UP OVER NORTH MS TUESDAY AFTERNOON... PROVIDING FOCUS FOR ADDITIONAL THUNDERSTORMS. WEDNESDAY WILL SEE DRIER AIR OVER ALL THE MIDSOUTH. TEMPERATURES WILL RECOVER TO NEAR OR SLIGHTLY ABOVE NORMAL VALUES FOR THE LATTER HALF OF THE WEEK. BY FRIDAY... DEWPOINTS RECOVER TO THE 60S. DRY CONDITIONS WILL PREVAIL...THOUGH CANNOT RULE OUT AN ISOLATED AFTERNOON THUNDERSTORM OR TWO UNDER AN UPPER LEVEL SYNOPTIC SCALE RIDGE. PWB && .AVIATION... 18Z TAF SET CONVECTIVE COMPLEX IS SET TO SWEEP THROUGH THE MIDSOUTH THIS AFTERNOON AND EARLY THIS EVENING. THIS IS CORROBORATED WELL BY THE LATEST HRRR RUN. HAVE TIMED TEMPO GROUPS AT ALL SITES. EXPECT A FEW QUIET HOURS AFTER THE PASSAGE OF THE FIRST ROUND OF TSRAS. EXPECT REDEVELOPMENT TO OCCUR OVERNIGHT AS THE FRONT MOVES INTO THE REGION. KEPT A VCTS GOING FOR NOW SINCE IT IS DIFFICULT TO TIME THIS MESOSCALE ACTIVITY BEYOND A FEW HOURS. EXPECT SSW WINDS AT 8-10 KTS THIS AFTERNOON. AS THE COMPLEX MOVES THROUGH WINDS SHOULD SHARPLY SHIFT TO THE NORTH AND GUST. ADDED A WIND GROUP TO KJBR IN ANTICIPATION OF THIS. NOT CONFIDENT ENOUGH AT THE OTHER 3 SITES TO ADD THIS YET. EXPECT WINDS TO BACK AFTER THE COMPLEX MOVES THROUGH AND THEN EVENTUALLY RETURN TO LIGHT SOUTHERLY OVERNIGHT. THE FRONT WILL PASS THROUGH EARLY TUESDAY AND WINDS WILL SHIFT TO THE NORTH AT 8-10 KTS. SJM && .PRELIMINARY POINT TEMPS/POPS... MEM 90 74 87 65 / 60 50 40 10 MKL 88 69 85 59 / 60 50 40 0 JBR 87 67 86 61 / 80 50 10 0 TUP 89 71 86 65 / 50 60 60 10 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1115 AM CDT MON JUN 11 2012 .UPDATE... UPDATED FOR ANTICIPATED CONVECTION AND SEVERE THREAT. && .DISCUSSION... A FORWARD PROPAGATING MCS CONTINUES TO PROGRESS EAST-SOUTHEASTWARD ACROSS SOUTHERN MISSOURI. THIS MCS IS PROGRESSING ALONG THE NORTHEASTERN PERIPHERY OF STRONG ELEVATED MIXED LAYER (EML/CAP) OVER MUCH OF ARKANSAS. THIS CAPPING INVERSION WAS ALSO EVIDENT FROM THE 12Z KLZK SOUNDING. THE CAP WEAKENS WITH EASTWARD EXTENT AND THE LATEST STEERING FLOW SUGGESTS THAT THE MCS SHOULD MAKE A TURN MORE TOWARDS THE SOUTH AND INTO THE HEART OF THE MID SOUTH. THE ATMOSPERE WILL BECOME STRONGLY UNSTABLE IN THE PRE-CONVECTIVE AIRMASS AHEAD OF THE MCS. MLCAPES SHOULD APPROACH OR EVEN EXCEED 4000 J/KG AS TEMPERATURES RISE TO NEAR 90 DEGREES WITH DEWPOINTS REMAINING IN THE LOWER TO MIDDLE 70S. IN ADDITION...STEEPENING MID LEVEL LAPSE RATES ON EDGE OF THE EML AROUND 7.0 C/KM AND LI/S BETWEEN -8C AND -12C SHOULD BE MORE THAN ENOUGH TO SUSTAIN CONVECTION AND ALLOW FOR THE POTENTIAL OF DAMAGING WINDS AND LARGE HAIL. CONVECTION SHOULD REMAIN ORGANIZED ALONG THE ADVANCING COLD POOL. ADDITIONAL CONVECTION MAY DEVELOP IN ADVANCE OF THE MCS AND WITH STRONG INSTABILITY AND WEAK CAPPING MAY ALSO POSE A SEVERE THREAT. PLAN TO EXPAND THE SLIGHT RISK AREAWIDE AND ADD MENTION OF SEVERE IN THE ZONES. ALSO POPS HAVE BEEN ADJUSTED TO REFLECT THE ANTICIPATED SITUATION. UPDATED ZONES AND GRIDS HAVE BEEN SENT AND THE HWO WILL BE UPDATED SHORTLY. JLH && .PREV DISCUSSION... /ISSUED 559 AM CDT MON JUN 11 2012/ DISCUSSION... /ISSUED 449 AM CDT MON JUN 11 2012/ PRIMARY SHORT TERM FORECAST CONCERN REMAINS RAIN CHANCES. EARLY THIS MORNING... SHORTWAVE RIDGING WAS SPREADING INTO THE MIDSOUTH... IN THE WAKE OF AN UPPER LEVEL SHEAR AXIS THAT BROUGHT SCATTERED SHOWERS TO THE REGION ON SUNDAY. UPSTREAM OF THE SHORTWAVE RIDGE AXIS... A ROBUST LINEAR MCS WAS DROPPING SOUTHEAST THROUGH NW MISSOURI. 850/500MB THICKNESS ANALYSIS SUGGESTS THIS FEATURE MAY BEGIN A MORE SOUTHERLY PROPAGATION. KSGF VAD WIND PROFILER SHOWED 25KTS OF INFLOW...THOUGH THIS INFLOW SHOULD WEAKEN CONSIDERABLY FOLLOWING SUNRISE. AFTER A WEAKENING OF THE MO STORM COMPLEX... NAM MODEL REDEVELOPS STORMS OVER THE OZARK PLATEAU TOWARD MIDDAY. THIS APPEARS A REASONABLE SCENARIO...IN RESPONSE TO SURFACE HEATING... FALLING HEIGHTS AND INCREASING UPPER LEVEL DIFFLUENCE AHEAD OF A LONG WAVE TROF. SURFACED BASED INSTABILITY SHOULD BE IN GOOD SUPPLY ACROSS THE MIDSOUTH THIS AFTERNOON... WITH PARTIAL SUN AND LOWER 70S DEWPOINTS. DESPITE WEAK SHORTWAVE RIDGING...THE HIGH DEWPOINTS SHOULD MAKE CONVECTIVE TEMPS ATTAINABLE THIS AFTERNOON...ENOUGH TO WARRANT CHANCE POPS. MORE ORGANIZED CONVECTIVE ACTIVITY WILL BE POSSIBLE LATE THIS AFTERNOON AND EVENING. THE RIGHT ENTRANCE REGION OF AN UPPER JET CORE WILL INCREASE UPPER LEVEL DIFFLUENCE OVER THE MIDSOUTH... A PATTERN WHICH WILL WILL REMAIN RELATIVELY STATIC OVERNIGHT. THIS SUGGESTS ELEVATED STORMS MAY CONTINUE INTO THE OVERNIGHT... THROUGH MESOSCALE PROPAGATION PROCESSES WILL PLAY A LARGE ROLE ON WHERE STORMS OCCUR. A SURFACE COLD FRONT ARRIVES TUESDAY MORNING...BRINGING DRIER MIDCONTINENTAL AIR TO AREAS NORTH OF I40 BY AFTERNOON. 06Z NAM SUGGESTS THE FRONT MAY HANG UP OVER NORTH MS TUESDAY AFTERNOON... PROVIDING FOCUS FOR ADDITIONAL THUNDERSTORMS. WEDNESDAY WILL SEE DRIER AIR OVER ALL THE MIDSOUTH. TEMPERATURES WILL RECOVER TO NEAR OR SLIGHTLY ABOVE NORMAL VALUES FOR THE LATTER HALF OF THE WEEK. BY FRIDAY... DEWPOINTS RECOVER TO THE 60S. DRY CONDITIONS WILL PREVAIL...THOUGH CANNOT RULE OUT AN ISOLATED AFTERNOON THUNDERSTORM OR TWO UNDER AN UPPER LEVEL SYNOPTIC SCALE RIDGE. PWB && .AVIATION... 12Z TAF SET COLD FRONT EXPECTED TO MOVE INTO THE CWA OVERNIGHT. HRRR MODEL HAS INITIALIZED THE BEST WITH ONGOING ACTIVITY UP ACROSS MISSOURI THUS HAVE LEANED TOWARD THIS SOLUTION WITH NEW TAF SET. EXPECT POSSIBLY TWO ROUNDS OF SHRA/TSRA ACTIVITY. FIRST...MODEL INDICATING A TSRA COMPLEX DEVELOPING OVER NW ARKANSAS/SW MISSOURI AROUND 17-18Z. MCS WILL PUSH EAST INTO KJBR AFTER 20Z AND POSSIBLY INTO KMEM AFTER 21Z. HAVE ADDED TEMPO GROUPS TO NEW TAF AS A RESULT. NAM ALSO SHOWS THIS FIRST ROUND OF ACTIVITY OCCURRING. THEREAFTER...CONFIDENCE WANES AS HOW FAR EAST AND SOUTH COMPLEX WILL PUSH. A SECOND ROUND OF ACTIVITY COULD OCCUR ALONG FRONT AS IT PUSHES INTO THE AREA. FOR NOW JUST LEFT VCTS WORDING AS CONFIDENCE IS LOW AS EARLIER TSRA COMPLEX (IF IT DOES DEVELOP) COULD STABILIZE THE ATMOSPHERE KILLING ANY ACTIVITY PUSHING INTO THE AREA ALONG THE FRONT. IF HAD TO PICK BEST TIMING AT KMEM FOR SECOND ROUND ACTIVITY TO OCCUR WOULD PICK SOMEWHERE BETWEEN 6Z- 10Z. OTHERWISE...IFR CIGS CURRENTLY OCCURRING SHOULD LIFT TO VFR BY 15-19Z DEPENDING ON LOCATION. SW WINDS BETWEEN 8-12 KTS EXPECTED TODAY...SPEEDS WILL DECREASE AFTER 01Z. KRM && .PRELIMINARY POINT TEMPS/POPS... MEM 90 74 87 65 / 60 50 40 10 MKL 88 69 85 59 / 60 50 40 0 JBR 87 67 86 61 / 80 50 10 0 TUP 89 71 86 65 / 50 60 60 10 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
549 PM CDT MON JUN 11 2012 .SHORT TERM...THROUGH WEDNESDAY NIGHT 253 PM CDT MON JUN 11 2012 MAIN FORECAST CONCERN IS WITH THE TEMPERATURES THROUGH TUESDAY AND RAIN CHANCES FOR WEDNESDAY NIGHT. SURFACE ANALYSIS THIS AFTERNOON SHOWS A WIND SHIFT/DRY LINE EXTENDING FROM NORTH CENTRAL WISCONSIN THROUGH THE FORECAST AREA INTO NORTHWEST MISSOURI. LOCAL RADAR SHOWS A FEW SHOWERS DEVELOPING ALONG THIS BOUNDARY. THE HRRR HAS BEEN CONSISTENTLY SHOWING THE SHOWERS FORMING OVER THE AREA THIS AFTERNOON. THE 11.15Z RUN CONTINUES THIS TREND SHOWING THEM MOVING TO THE EAST THROUGH THE REMAINDER OF THE AFTERNOON WITH THE BOUNDARY. THE SHOWERS AND BOUNDARY ARE EXPECTED TO BE EAST OF THE FORECAST AREA BY 00Z...SO NO PLANS TO CARRY ANY EVENING RAIN CHANCES. AFTER THAT...IT IS A QUESTION OF HOW MUCH COOL AIR SETTLES IN OVER THE AREA AS HIGH PRESSURE BUILDS IN. BOTH THE 11.12Z NAM AND GFS INDICATE 925 MB TEMPERATURES SHOULD DIP DOWN TO 5-7C TONIGHT BEFORE STARTING TO REBOUND TO AROUND 10C TUESDAY NIGHT. SURFACE TEMPERATURES WILL GENERALLY FALL TO AROUND 50 TONIGHT AS A NORTHWEST BREEZE IS EXPECTED TO CREATE JUST ENOUGH MIXING TO KEEP THEM FROM GOING ANY LOWER. HIGHS TUESDAY WILL BE MUCH COOLER TOPPING OUT IN THE UPPER 60S TO LOWER 70S. THE COOLEST NIGHT WILL BE TUESDAY NIGHT DESPITE THE SLIGHTLY WARMER 925 MB TEMPERATURES. THE SURFACE HIGH WILL BE RIGHT OVER THE AREA ALLOWING THE WINDS TO DECOUPLE AND EXCELLENT RADIATIONAL COOLING TO OCCUR. EXPECTING LOWS TO BE IN THE 40S WITH THE FAVORED COOLER SPOTS DIPPING INTO THE UPPER 30S. AS THE SURFACE HIGH THEN MOVES OFF TO THE EAST...THE CONCERN BECOMES WHETHER THERE WILL BE ANY SHOWERS THAT DEVELOP IN THE RETURN FLOW. THE MODELS SUGGEST THERE WILL BE A SHORT WAVE TROUGH MOVING ACROSS THE DAKOTAS WEDNESDAY NIGHT WITH THE BEST PV ADVECTION IN THE 500-300MB LAYER STAYING NORTHWEST OF THE AREA. THE BEST LOW LEVEL MOISTURE TRANSPORT WILL BE INTO THIS WAVE...BUT THERE WILL ALSO BE A WEAKER BRANCH SPLITTING OFF TO THE NORTHEAST AHEAD OF ANOTHER SHORT WAVE TROUGH. THIS PLACES THE WESTERN SECTIONS OF THE FORECAST UNDER UNDER THE EASTERN CONVERGENT SIDE OF THE MOISTURE TRANSPORT AXIS. THIS IS EXPECTED TO COINCIDE WITH 1-2 UBAR/S OF UP GLIDE ON THE 310K ISENTROPIC SURFACE AND WHILE THE FORCING IS NOT THAT STRONG FELT THERE WAS ENOUGH TO JUSTIFY A 20 PERCENT RAIN CHANCES LATE TUESDAY NIGHT OVER THE NORTHWEST SECTIONS OF THE AREA. .LONG TERM...THURSDAY THROUGH MONDAY 253 PM CDT MON JUN 11 2012 CONSIDERABLE UNCERTAINTY IN THE EXTENDED PART OF THE FORECAST. THE UPPER LEVEL RIDGE IS EXPECTED TO BUILD FROM THE SOUTHERN PLAINS INTO SOUTHEAST CANADA. MODELS HAVE BEEN SHOWING RUN TO RUN DIFFERENCES ON HOW FAR WEST THE RIDGE WILL EXTEND AND WHETHER THIS WILL ALLOW ANY SHORT WAVE TROUGHS IN THE SOUTHWEST FLOW TO IMPACT THE AREA. THE 11.12Z ECMWF HAS COME IN WITH AN EVEN FLATTER AND FARTHER EAST RIDGE AXIS WHICH ALLOWS A SYSTEM TO MOVE ACROSS THE UPPER MIDWEST FOR THE WEEKEND. THE GFS AND 11.12Z GEM ARE MORE ROBUST WITH THE RIDGE AXIS WHICH DEFLECTS THIS SYSTEM OFF TO THE NORTHWEST. MODELS ARE KNOWN TO STRUGGLE MIGHTILY WITH SOUTHWEST FLOW SO HAVE OPTED TO LEAVE IN THE SMALL RAIN CHANCES AS CONFIDENCE TO PULL THEM OUT IS JUST NOT THERE. && .AVIATION...TONIGHT AND TUESDAY 549 PM CDT MON JUN 11 2012 VFR CONDITIONS WILL OCCUR THROUGH TOMORROW AS COOLER AIR MOVES INTO THE REGION BEHIND A COLD FRONT. WINDS WILL BE THE TRICKIEST PART OF THE FORECAST WITH SOME FORECAST GUIDANCE...THE 11.21Z RAP MODEL...SHOWING THAT SOME LOW LEVEL MIXING WILL CONTINUE OVERNIGHT AND KEEP SOME GUSTS AROUND. AS SURFACE TEMPERATURES DROP THIS EVENING...THINK THAT WE SHOULD BE ABLE TO DECOUPLE AND END THE GUSTS BETWEEN 1-2Z. THE PRESSURE GRADIENT WILL REMAIN TIGHT OVERNIGHT...SO HAVE KEPT THE SUSTAINED WINDS UP BETWEEN 12-16KTS. OTHERWISE...SKIES WILL CLEAR OUT WITH VFR FAIR WEATHER CU REFORMING TOMORROW MORNING. && .ARX WATCHES/WARNINGS/ADVISORIES... 253 PM CDT MON JUN 11 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
254 PM CDT MON JUN 11 2012 .SHORT TERM...THROUGH WEDNESDAY NIGHT 253 PM CDT MON JUN 11 2012 MAIN FORECAST CONCERN IS WITH THE TEMPERATURES THROUGH TUESDAY AND RAIN CHANCES FOR WEDNESDAY NIGHT. SURFACE ANALYSIS THIS AFTERNOON SHOWS A WIND SHIFT/DRY LINE EXTENDING FROM NORTH CENTRAL WISCONSIN THROUGH THE FORECAST AREA INTO NORTHWEST MISSOURI. LOCAL RADAR SHOWS A FEW SHOWERS DEVELOPING ALONG THIS BOUNDARY. THE HRRR HAS BEEN CONSISTENTLY SHOWING THE SHOWERS FORMING OVER THE AREA THIS AFTERNOON. THE 11.15Z RUN CONTINUES THIS TREND SHOWING THEM MOVING TO THE EAST THROUGH THE REMAINDER OF THE AFTERNOON WITH THE BOUNDARY. THE SHOWERS AND BOUNDARY ARE EXPECTED TO BE EAST OF THE FORECAST AREA BY 00Z...SO NO PLANS TO CARRY ANY EVENING RAIN CHANCES. AFTER THAT...IT IS A QUESTION OF HOW MUCH COOL AIR SETTLES IN OVER THE AREA AS HIGH PRESSURE BUILDS IN. BOTH THE 11.12Z NAM AND GFS INDICATE 925 MB TEMPERATURES SHOULD DIP DOWN TO 5-7C TONIGHT BEFORE STARTING TO REBOUND TO AROUND 10C TUESDAY NIGHT. SURFACE TEMPERATURES WILL GENERALLY FALL TO AROUND 50 TONIGHT AS A NORTHWEST BREEZE IS EXPECTED TO CREATE JUST ENOUGH MIXING TO KEEP THEM FROM GOING ANY LOWER. HIGHS TUESDAY WILL BE MUCH COOLER TOPPING OUT IN THE UPPER 60S TO LOWER 70S. THE COOLEST NIGHT WILL BE TUESDAY NIGHT DESPITE THE SLIGHTLY WARMER 925 MB TEMPERATURES. THE SURFACE HIGH WILL BE RIGHT OVER THE AREA ALLOWING THE WINDS TO DECOUPLE AND EXCELLENT RADIATIONAL COOLING TO OCCUR. EXPECTING LOWS TO BE IN THE 40S WITH THE FAVORED COOLER SPOTS DIPPING INTO THE UPPER 30S. AS THE SURFACE HIGH THEN MOVES OFF TO THE EAST...THE CONCERN BECOMES WHETHER THERE WILL BE ANY SHOWERS THAT DEVELOP IN THE RETURN FLOW. THE MODELS SUGGEST THERE WILL BE A SHORT WAVE TROUGH MOVING ACROSS THE DAKOTAS WEDNESDAY NIGHT WITH THE BEST PV ADVECTION IN THE 500-300MB LAYER STAYING NORTHWEST OF THE AREA. THE BEST LOW LEVEL MOISTURE TRANSPORT WILL BE INTO THIS WAVE...BUT THERE WILL ALSO BE A WEAKER BRANCH SPLITTING OFF TO THE NORTHEAST AHEAD OF ANOTHER SHORT WAVE TROUGH. THIS PLACES THE WESTERN SECTIONS OF THE FORECAST UNDER UNDER THE EASTERN CONVERGENT SIDE OF THE MOISTURE TRANSPORT AXIS. THIS IS EXPECTED TO COINCIDE WITH 1-2 UBAR/S OF UP GLIDE ON THE 310K ISENTROPIC SURFACE AND WHILE THE FORCING IS NOT THAT STRONG FELT THERE WAS ENOUGH TO JUSTIFY A 20 PERCENT RAIN CHANCES LATE TUESDAY NIGHT OVER THE NORTHWEST SECTIONS OF THE AREA. .LONG TERM...THURSDAY THROUGH MONDAY 253 PM CDT MON JUN 11 2012 CONSIDERABLE UNCERTAINTY IN THE EXTENDED PART OF THE FORECAST. THE UPPER LEVEL RIDGE IS EXPECTED TO BUILD FROM THE SOUTHERN PLAINS INTO SOUTHEAST CANADA. MODELS HAVE BEEN SHOWING RUN TO RUN DIFFERENCES ON HOW FAR WEST THE RIDGE WILL EXTEND AND WHETHER THIS WILL ALLOW ANY SHORT WAVE TROUGHS IN THE SOUTHWEST FLOW TO IMPACT THE AREA. THE 11.12Z ECMWF HAS COME IN WITH AN EVEN FLATTER AND FARTHER EAST RIDGE AXIS WHICH ALLOWS A SYSTEM TO MOVE ACROSS THE UPPER MIDWEST FOR THE WEEKEND. THE GFS AND 11.12Z GEM ARE MORE ROBUST WITH THE RIDGE AXIS WHICH DEFLECTS THIS SYSTEM OFF TO THE NORTHWEST. MODELS ARE KNOWN TO STRUGGLE MIGHTILY WITH SOUTHWEST FLOW SO HAVE OPTED TO LEAVE IN THE SMALL RAIN CHANCES AS CONFIDENCE TO PULL THEM OUT IS JUST NOT THERE. && .AVIATION...THIS AFTERNOON THROUGH TUESDAY 1220 PM CDT MON JUN 11 2012 QUIET...GOOD VFR PERIOD FOR THIS AFTERNOON THRU TUESDAY AS DRIER CANADIAN HIGH PRESSURE BUILDS INTO THE REGION. WITH COOLER TEMPS ALOFT AND STEEP LOW LEVEL LAPSE RATES...SCT 4K-5K FT DIURNAL CUMULUS WILL DEVELOP FOR THE LATE MORNING AND AFTERNOON HOURS. THE STEEP LAPSE RATES AND DEEPER MIXING WILL ALLOW FOR SOME BRISK/GUSTY WEST TO NORTHWEST WINDS THIS AFTERNOON...DIMINISHING THIS EVENING AS TEMPS COOL AND THE MIXING DEPTH DECREASES. DIURNAL WARMING WITH STEEP LAPSE RATES TO 900-850MB ON TUE WILL RESULT IN NORTHWEST WINDS 10-15KT G20KTS FOR TUE AFTERNOON. WITH LIGHT WINDS...CLEAR SKIES AND CHILLY LOWS EXPECTED TUE NIGHT...WILL HAVE TO WATCH FOR VALLEY FOG FORMATION IN THE 09Z-13Z WED MORNING PERIOD AT SITES LIKE KONA/KLSE/ KPDC/KOVS/KLNR. && .ARX WATCHES/WARNINGS/ADVISORIES... 253 PM CDT MON JUN 11 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1220 PM CDT MON JUN 11 2012 .SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT 330 AM CDT MON JUN 11 2012 MAIN FORECAST CONCERN IS ON TEMPERATURES THROUGHOUT THE SHORT TERM. CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED RIDGING OVER BRITISH COLUMBIA AND THE EASTERN GREAT LAKES... WITH TROUGHING IN-BETWEEN FROM SOUTH CENTRAL CANADA INTO THE NORTHERN PLAINS. WITHIN THIS TROUGH...A FAIRLY POTENT SHORTWAVE STRETCHED FROM NORTHERN MN SOUTHWEST INTO SOUTHEAST SOUTH DAKOTA... WHICH IS EVIDENT BY A DEEP DRY SLOT ON WATER VAPOR AND CLEAR SKIES ON IR IMAGERY. 00Z ABR SOUNDING IN THE DRY SLOT WAS VERY DRY WITH A PRECIPITABLE WATER OF 0.51 INCHES. AHEAD OF THE SHORTWAVE...AN AREA OF CONVECTION STRETCHED FROM NORTHERN WI SOUTH INTO FAR NORTHEAST IA/SOUTHWEST WI AND TO THE KANSAS CITY AREA. THE STRONGEST CONVECTION HAS SHIFTED TO THE SOUTHERN END OF THIS LINE...DUE TO BETTER LOW LEVEL CONVERGENCE SEEN IN 925 AND 850MB PROFILER DATA. CONVECTION THAT WAS OVER MN LAST EVENING HAS WEAKENED...DUE TO THE BETTER LOW LEVEL CONVERGENCE AND MOISTURE TRANSPORT SHIFTING SOUTH...DECREASING INSTABILITY AHEAD OF THE CONVECTION...AS WELL AS RAP LOW TO MID LEVEL FRONTOGENESIS FIELDS INDICATING WEAKENING THROUGH THE NIGHT. THE ONE CAVEAT TO THIS IS AN MCV RIDING NORTHEAST...ENTERING THE LA CROSSE AREA AS OF 08Z. ON ITS SOUTHEAST SIDE...THE COMBINATION OF DCAPE AROUND 1000 J/KG PER RAP ANALYSIS AND STORMS LINED ORTHOGONAL TO THE 0-3KM SHEAR VECTOR HAS HELPED PRODUCE SOME STRONG TO POSSIBLY DAMAGING WIND GUSTS. AT THE SURFACE...A COLD FRONT WAS PRESENT JUST BEHIND THE CONVECTION... STRETCHING FROM NEAR THUNDER BAY ONTARIO TO LA CROSSE WI. A SECONDARY COLD FRONT WAS PRESENT IN NORTHWEST MN. IN THE WAKE OF THIS FRONT...SATELLITE IMAGERY AND OBSERVATION SHOWED LOW CLOUDS... ISOLATED LIGHT SHOWERS AND MUCH COOLER TEMPERATURES IN THE 50S. TODAY AND TONIGHT...UPPER TROUGHING OVER SOUTH CENTRAL CANADA AND THE NORTHERN PLAINS IS FORECAST TO CONTINUE AN EAST-NORTHEASTWARD MOVEMENT...BEING PROPELLED BY THE CURRENT POTENT SHORTWAVE IN MN AND A SECOND ONE DROPPING DOWN THE BACK SIDE OF THE TROUGH. ALTHOUGH THE BULK OF THE TROUGH LIFTS INTO MANITOBA...NORTHWEST ONTARIO AND LAKE SUPERIOR...SOME OF THE TROUGHING WILL EXTEND DOWN INTO THE FORECAST AREA BY TONIGHT. IN SUMMARY...EXPECT THE TROUGH TO BRING A COOL DOWN FROM WHAT HAS BEEN SEEN LATELY. FIRST ISSUE TO CONTEND WITH IS THE ONGOING SHOWERS AND EMBEDDED THUNDERSTORMS. LATEST HRRR/RAP GUIDANCE AS WELL AS 11.00Z NAM SUGGESTS THE PRECIPITATION MAY BE COMPLETELY EAST OF THE AREA BY 12Z. LOOKS LIKE THERE SHOULD BE A BREAK AS INSTABILITY TRIES TO BUILD AHEAD OF THE MAIN COLD FRONT. HOWEVER...THE MAIN COLD FRONT WILL BE EAST OF THE AREA BEFORE IT CONVECTS...LIKELY BETWEEN 18-21Z. ATTENTION THEN TURNS TO THE SECONDARY COLD FRONT. THIS COMES THROUGH IN THE AFTERNOON...WITH WINDS INCREASING OUT OF THE WEST BEHIND IT. NO PRECIPITATION ANTICIPATED...BUT SOME STRATOCUMULUS AS SEEN BACK IN THE DAKOTAS SHOULD FILTER IN. THESE CLOUDS WILL LIKELY BECOME CELLULAR RESULTING FROM THE STRONG JUNE SUN...THUS DISSIPATING WITH LOSS OF HEATING IN THE EVENING. 850MB TEMPS OF 12-16C AT 18Z PLUS PLENTY OF SUN AND DRY AIR AHEAD OF THE SECONDARY COLD FRONT SHOULD ALLOW TEMPERATURES TO CLIMB INTO THE UPPER 70S TO MID 80S. TEMPERATURES MAY FALL SLIGHTLY ONCE THE SECONDARY FRONT MOVES IN. BETTER TEMPERATURE FALL EXPECTED TONIGHT AIDED BY NOCTURNAL COOLING AND CONTINUED COLD ADVECTION ON BREEZY NORTHWEST WINDS. BY 12Z TUESDAY...850MB TEMPS ARE PROGGED TO DROP AT LEAST DOWN TO 4-7C...AND PERHAPS SLIGHTLY COOLER AS INDICATED BY THE NAM. WENT WITH A BLEND OF GUIDANCE FOR LOWS...RESULTING IN UPPER 40S TO MID 50S. TUESDAY AND TUESDAY NIGHT...UPPER FLOW IS PROGGED TO GRADUALLY TURN ZONAL DURING THIS PERIOD AS THE UPPER TROUGHING LIFTS AWAY FROM THE AREA. WITHIN THE ZONAL FLOW...A SHORTWAVE IS INDICATED TO REACH CENTRAL SOUTH DAKOTA BY 12Z WEDNESDAY. SOME MID/HIGH CLOUDS ASSOCIATED WITH ISENTROPIC LIFT AHEAD OF THIS SHORTWAVE COULD GET INTO SOUTHEAST MN AND NORTHEAST IA LATE IN THE NIGHT. OTHERWISE... PLENTY OF DRY AIR NOTED BY PRECIPITABLE WATER VALUES OF 0.5 INCH OR LESS SHOULD KEEP SKIES CLEAR. ALTHOUGH THE DRY AIR AND CLEAR SKIES ARE FAVORABLE FOR WARMING...TEMPERATURES ON TUESDAY MAY STRUGGLE GIVEN 850MB TEMPS PROGGED TO STILL BE AT 4-7C AT 18Z. IN FACT...TAYLOR COUNTY MAY ONLY BE AROUND 2C. THESE ARE 2 STANDARD DEVIATIONS BELOW NORMAL. AS A RESULT...ONLY FORECAST HIGHS IN THE MID 60S TO LOW 70S...20 DEGREES COLDER THAN YESTERDAY. DEWPOINTS ARE LIKELY TO TANK FROM MIXING OF THE DRY AIR. SHOULD BE BREEZY TOO IN THE MORNING ADDING AN EXTRA CHILL BEFORE SURFACE HIGH PRESSURE BUILDS OVERHEAD IN THE EVENING TO CALM WINDS. THIS SETS THE STAGE FOR GOOD RADIATIONAL COOLING TUESDAY NIGHT...ESPECIALLY IN WISCONSIN. WOULD NOT BE SURPRISED TO HAVE SOME UPPER 30S FOR LOWS IN THE TYPICAL COLD SPOTS. WARMER READINGS ARE EXPECTED WEST OF THE MISSISSIPPI RIVER WHERE RETURN FLOW AND CLOUDS COME IN. WEDNESDAY AND WEDNESDAY NIGHT...UPPER LEVEL FLOW LOOKS TO AMPLIFY AGAIN AS TROUGHING DROPS DOWN INTO SOUTHWEST CANADA AND THE PACIFIC NORTHWEST BY 12Z THURSDAY. THIS AMPLIFICATION SHOULD HELP TAKE THE SHORTWAVE THAT WAS COMING INTO SOUTH DAKOTA TUESDAY NIGHT AND LIFT IT WELL NORTHWEST OF THE AREA. BY 00Z THURSDAY...ALL MODELS HAVE IT CROSSING CENTRAL OR NORTHERN MN. GIVEN DRY LOW LEVEL AIRMASS IN PLACE BY THE SURFACE HIGH PRESSURE AREA...AS WELL AS THE TRACK OF THE SHORTWAVE...NOT ANTICIPATING ANY PRECIPITATION TO SPREAD INTO THE FORECAST AREA. HOWEVER...CLOUD COVER IS AN ISSUE. INCREASING 305-310 K ISENTROPIC LIFT EAST OF THE SHORTWAVE SHOULD SPREAD MID AND HIGH CLOUDS ACROSS MUCH OF THE AREA ON WEDNESDAY. THESE CLOUDS MAY LIMITING HEATING SOMEWHAT...DESPITE WARMER 850MB TEMPS IN THE 8-12C RANGE. KEPT HIGHS IN THE LOW TO MID 70S...WHICH ARE ABOUT 5 DEGREES COOLER THAN WHAT THEY COULD BE IF FULL SUN WAS OBSERVED. THE CLOUDS DO LOOK TO CLEAR OUT WEDNESDAY NIGHT AS THE SHORTWAVE HEADS INTO ONTARIO. FOLLOWED A BLEND OF GUIDANCE FOR LOWS GIVEN NO STRONG SIGNAL TO GO COLDER OR WARMER. .LONG TERM...THURSDAY THROUGH SUNDAY NIGHT 330 AM CDT MON JUN 11 2012 11.00Z ECMWF/CANADIAN/GFS AND GFS ENSEMBLES REMAIN IN PRETTY GOOD AGREEMENT ON THE UPPER LEVEL PATTERN...AND IN FACT ARE IN BETTER AGREEMENT NOW COMPARED TO YESTERDAY. CONSENSUS IS THAT TROUGHING WILL HOLD OVER THE NORTHWESTERN U.S. THROUGH MUCH OF THE LONG TERM PERIOD...RESULTING IN STRENGTHENING RIDGING DOWNSTREAM OVER THE WESTERN GREAT LAKES. IN FACT...BY SUNDAY NIGHT WHEN MODELS HAVE THE TROUGH DIGGING MORE INTO THE NORTHERN ROCKIES...THE RIDGE DOWNSTREAM REALLY STRENGTHENS. IT APPEARS THAT MOST OF THE SHORTWAVES EJECTING OUT OF THE TROUGH WILL END UP STAYING MOSTLY TO THE NORTHWEST OF THE AREA. THUS...OVERALL MUCH OF THIS LONG TERM FORECAST LOOKS DRY. HAVE MAINTAINED SOME 20-30 PERCENT CHANCES OVER NORTHWEST PORTIONS OF THE AREA ON SATURDAY...NORTH OF I-90 SATURDAY NIGHT AND ACROSS THE ENTIRE AREA SUNDAY INTO SUNDAY NIGHT. THESE MOSTLY STEM FROM BEING ON THE NOSE OF SOME MOISTURE TRANSPORT AND SHORTWAVES COMING CLOSE TO THE AREA. HOWEVER...IT IS POSSIBLE THESE CHANCES MAY BE ABLE TO BE REMOVED IN LATER FORECASTS WITH MODELS TRENDING DRIER. ONE OTHER PERIOD TO WATCH IS THURSDAY WITH THE 11.00Z ECMWF BEING REALLY AGGRESSIVE IN DEVELOPING PRECIPITATION OVER MN. THIS APPEARS TO BE RELATED TO A SURGE OF WARM...MOIST AIR OCCURRING WITH THE BUILDING RIDGING. GIVEN THAT THE MODEL DOES NOT BRING THE PRECIPITATION INTO THE AREA AND OTHER MODELS SUGGESTING DRIER...HAVE KEPT THURSDAY DRY. WHAT COULD BE MORE SIGNIFICANT FOR THE LONG TERM FORECAST IS TEMPERATURES. WITH THE AREA NOW STRONGLY FORECAST TO BE UNDER RIDGING...AND IN BROAD BREEZY SOUTHERLY FLOW...WE COULD BE DEALING WITH ANOTHER LONG STRETCH OF 80S AND PERHAPS 90S. NEW ECMWF REALLY CAME IN WARM...WITH 850MB TEMPS FRIDAY THROUGH MONDAY HOVERING AROUND 20C OR SO...RESULTING IN HIGHS OF 90-95. HAVE BOOSTED TEMPERATURES UP ABOVE THE CONSENSUS AND THESE MAY STILL BE TOO COOL. && .AVIATION...THIS AFTERNOON THROUGH TUESDAY 1220 PM CDT MON JUN 11 2012 QUIET...GOOD VFR PERIOD FOR THIS AFTERNOON THRU TUESDAY AS DRIER CANADIAN HIGH PRESSURE BUILDS INTO THE REGION. WITH COOLER TEMPS ALOFT AND STEEP LOW LEVEL LAPSE RATES...SCT 4K-5K FT DIURNAL CUMULUS WILL DEVELOP FOR THE LATE MORNING AND AFTERNOON HOURS. THE STEEP LAPSE RATES AND DEEPER MIXING WILL ALLOW FOR SOME BRISK/GUSTY WEST TO NORTHWEST WINDS THIS AFTERNOON...DIMINISHING THIS EVENING AS TEMPS COOL AND THE MIXING DEPTH DECREASES. DIURNAL WARMING WITH STEEP LAPSE RATES TO 900-850MB ON TUE WILL RESULT IN NORTHWEST WINDS 10-15KT G20KTS FOR TUE AFTERNOON. WITH LIGHT WINDS...CLEAR SKIES AND CHILLY LOWS EXPECTED TUE NIGHT...WILL HAVE TO WATCH FOR VALLEY FOG FORMATION IN THE 09Z-13Z WED MORNING PERIOD AT SITES LIKE KONA/KLSE/ KPDC/KOVS/KLNR. && .ARX WATCHES/WARNINGS/ADVISORIES... 330 AM CDT MON JUN 11 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...DAS