Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/24/12


AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
927 PM MDT WED MAY 23 2012 .UPDATE... ISSUED AT 926 PM MDT WED MAY 23 2012 THE COLD FRONT IS SWEEPING SOUTH ACROSS SE UTAH/SW COLORADO. AT 03Z THIS EVENING...THE COLD FRONT IS PASSING THE DURANGO AIRPORT. WHILE WINDS ARE EXPECTED TO SUBSIDE IN THE POST FRONTAL AIR MASS...WINDS STILL FAIRLY STRONG AND ELECTED TO EXTEND THE RED FLAG WARNING AND WIND ADVISORY THROUGH 11 PM. THE VAIL PASS WEB CAM SHOWED LIGHT SNOW ACCUMULATION ON THE GRASSY AND DIRT SURFACES. HIGH MOUNTAIN REMOTE SENSORS INDICATE THAT TEMPERATURES ARE AROUND 32F AND INDICATE THAT SNOW ACCUMULATIONS WILL BE FAIRLY COMMON ABOVE 10K FEET. THE BRUNT OF THE PRECIPITATION OCCURS BEFORE MIDNIGHT WITH THE HRRR SHOWING FAST DROP OFF IN QPF AMOUNTS AFTER 06Z. ELECTED TO ISSUE SPECIAL WEATHER STATEMENT TO ADDRESS THE IMPACT OF LATE SEASON SNOWFALL INSTEAD OF HOIST A WINTER WEATHER ADVISORY. WIDESPREAD SNOW ABOVE 10K FEET IS EXPECTED TO TAPER OFF WITHIN THE NEXT 2-3 HOURS (AND PAVEMENTS MAY STAY WET WITH SLUSHY AREAS). UPDATE ISSUED AT 723 PM MDT WED MAY 23 2012 AS THE NOSE OF JET PUNCHES INTO WRN COLORADO...PRECIPITATION HAS INCREASED ACROSS PARTS OF NORTHWEST AND WEST CENTRAL COLORADO. RAISED POPS TO ACCOUNT FOR THIS INCREASE...ALTHOUGH TRACE AMOUNTS MAY BE THE ONLY RAINFALL THE LOWER VALLEYS RECEIVE AS THE EVENING SOUNDING SHOWS A MOSTLY DRY SUB CLOUD LAYER. HOWERVER PRECIPITABLE WATER DID RISE TO ONE HALF INCH. THESE SHOWERS HAVE ENHANCED GUSTY WINDS IN THE CENTRAL VALLEY WITH LOCAL GUSTS TO 40 MPH. FARTHER SOUTH...GUSTY WINDS HAVE BEEN STRONGER WITH GUSTS OF 45 TO 50 MPH FAIRLY COMMON. NO UPDATES TO THE WIND ADVISORY THAT EXPIRES AT 9 PM MDT THIS EVENING. && .SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT) ISSUED AT 345 PM MDT WED MAY 23 2012 LARGE SCALE ASCENT IS INCREASING OVER NORTHERN UTAH INTO NORTHWEST COLORADO AHEAD OF THE MID LEVEL TROF AXIS DROPPING THROUGH THE GREAT BASIN. DARKENING IN THE WATER VAPOR IMAGERY SHOWING THIS LIFT BEING ENHANCED BY ARRIVING JET MAX AND ASSOCIATED PV LOBE WITH INCREASING INSTABILITY FROM DAYTIME HEATING AND COOLER AIR MOVING IN WITH THE TROF ALSO AIDING ASCENT. 88D MOSAIC IS RESPONDING BY SHOWING AN INCREASE IN COVERAGE MAINLY NORTH OF A MOAB TO MONTROSE TO GUNNISON LINE WHICH IS NEAR WHERE THE SURFACE FRONT HAS SETTLED AND MAY BE WAVERING. THIS LIFT SEEMS TO BE HELPING TO MIX OUT THE ATMOSPHERE NORTH OF FRONT AS WELL WITH WINDS PICKING UP AT GJT THE PAST HOUR OR SO. SOME GUIDANCE INDICATING VERY GUSTY WINDS THROUGH EARLY EVENING ACROSS THE GRAND VALLEY AND WILL CONTINUE TO MONITOR. FARTHER SOUTH IN ADVISORY REGION STRONG MIXING AHEAD OF THE FRONT HAS BEEN PUSHING WIND GUSTS NEAR 45 MPH AND EXPECT THE NEXT FEW HOURS THEY COULD CONTINUE TO STRENGTHEN SO WILL LEAVE ADVISORY AS IS. AS FOR PRECIPITATION THE BEST FOCUS CONTINUES TO POINT AT THE NORTHERN AND CENTRAL MOUNTAINS THROUGH THIS EVENING WHERE MID LEVEL LAPSE RATES WILL CONTINUE TO STEEPEN UNDER THE STRONGER DYNAMICS ALOFT. MOISTURE IS ALREADY IN PLACE NORTH OF THE FRONT SO SHOULD NOT TAKE MUCH TO GET PRECIPITATION TO THE SURFACE. ONE CAVEAT HOWEVER IS DRIER AIR IS ADVECTING IN A LOW LEVELS FROM WYOMING SO WILL KEEP THE HIGHEST POPS ON THE TERRAIN WHERE OROGRAPHICS WILL ALSO CONTINUE INTO THE THURSDAY MORNING AS THE UPPER SUPPORT LIFTS OUT OF OUR REGION. WOULD NOT BE SURPRISED TO SEE SOME LIGHT SNOW ABOVE THE 9000 FT LEVEL BUT SHOULD NOT ANTICIPATING A LARGE IMPACT ATTM WITH AN INCH OR LESS LIMITED TO THE VEGETATION. THE SURFACE FRONT WILL BE SAGGING THROUGH THE SOUTHERN CWA TONIGHT AS WELL AND THIS MAY HELP TRIGGER SOME ISOLATED CONVECTION IN THE SOUTHERN MOUNTAINS...BUT CONFIDENCE NOT HIGH SO POPS REFLECT THIS. TEMPERATURES WILL BE QUITE COOL COMPARED TO THE PAST FEW NIGHTS WITH SOME VALLEYS IN THE NORTH DROPPING TO NEAR THE FREEZING MARK. WITH THE FRONT NEAR THE SOUTHERN BORDER ON THURSDAY AND COOLER DAY LOOKS ON TRACK AND THERE SHOULD BE A FAIR AMOUNT OF SUNSHINE IN PLACE BEFORE AFTERNOON HEATING STARTS POPPING THE CUMULUS. THE EXCEPTION WILL BE OVER THE FAR NORTHERN MOUNTAINS EARLY DUE TO THE MOIST DENDRITIC FLOW AND COLD POOL ALOFT WHICH SHOULD PRODUCE SOME LIGHT PRECIPITATION. HIGHS ACTUALLY LOOK TO BE RUN NEAR OR BELOW NORMAL OUTSIDE THE 4 CORNERS REGION AND DID USE A BLEND OF GUIDANCE. A STRONGER WESTERN SYSTEM WILL BE PUSHING INTO THE EASTERN GREAT BASIN TOMORROW NIGHT. THIS WILL QUICKLY BACK AND INCREASE THE FLOW TO THE SOUTHWEST AND PUSH THE WARM FRONT STRUCTURE BACK NORTHWARD THROUGH THE CWA. ATTM THE MODELS ARE PUTTING OUT SOME LIGHT PRECIPITATION BUT MODEL SOUNDINGS WOULD INDICATE THIS IS MOSTLY IN THE FORM OF ACCAS MOVING OVERHEAD IN THE STRONG WAA PATTERN. FOR NOW JUST PUT IN SOME ISOLATED MENTION OVER THE HIGHEST TERRAIN IN THE NORTHEAST CWA. BETTER MIXING AND THE WAA SHOULD PUSH LOWS UP A FEW DEGREES OVER TONIGHT/S READINGS. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 345 PM MDT WED MAY 23 2012 MODELS REMAIN CONSISTENT ON DROPPING THE NEXT PACIFIC TROUGH INTO THE WESTERN GREAT BASIN FRIDAY AND THEN LIFTING IT OUT TO THE NORTHEAST THIS WEEKEND...DRAGGING A COLD FRONT ACROSS SAT OR SAT EVENING. NOT A LOT OF MOISTURE INDICATED WITH THIS FRONT...SO JUST SLIGHT CHANCE TO CHANCE POPS FOR MAINLY NE UT AND NW CO SHOULD SUFFICE FOR NOW. ABOVE NORMAL TEMPS FOR FRIDAY AS WARM ADVECTION RETURNS. WITH THE MAIN UPPER LOW LIFTING OUT WELL TO OUR NW...MAY SEE THE EASTWARD PROGRESSION OF THE COLD FRONT SLOW ON SATURDAY SO WILL KEEP MAX TEMPS ON THE WARM SIDE SAT OVER ALL BUT NE UT. THE BIGGEST IMPACT WILL LIKELY BE THE SOUTH TO SOUTHWEST WIND... WHICH IS EXPECTED TO STRENGTHEN SIGNIFICANTLY FRIDAY THROUGH SATURDAY. BOTH NAM AND GFS SHOW 40-45 KTS AT 700 MB...WITH SOME AREAS OF 50-55 KTS WINDS INDICATED FRI NIGHT. WIND ADVISORIES MAY BE NEEDED...AND A FIRE WEATHER WATCH HAS ALREADY BEEN ISSUED FOR FRI AND SAT. COOLER TEMPERATURES FOLLOW FOR SUNDAY BEHIND THE FRONT WITH A CHANCE OF SHOWERS PERSISTING FOR THE NORTHERN MTNS IN THE WEST TO NW FLOW. DRY WESTERLY FLOW EXPECTED MONDAY THROUGH WEDNESDAY WITH TEMPERATURES WARMING UP AGAIN. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 345 PM MDT WED MAY 23 2012 SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED TO INCREASE OVER THE NEXT FEW HOURS ACROSS THE NORTHERN AND CENTRAL MOUNTAINS OF COLORADO. CONFIDENCE NOT HIGH ENOUGH TO PLACE RESTRICTIONS IN PREVAILING FORECASTS OVER THE HIGH VALLEY TERMINALS SUCH AS EGE AND ASE...BUT PASSING SHOWERS CAN BE ANTICIPATED. COLD FRONTAL PASSAGE HAS LIMITED MIXING THE VALLEYS AS WELL AND UP VALLEY WINDS HAVE BEEN SLOW TO DEVELOP BUT THE SHOWERS MAY HELP ENHANCE THIS AND STILL EXPECT SOME GUSTY WINDS. WINDS WILL BE STRONG FROM THE GRAND VALLEY INTO SOUTHWEST COLORADO AFFECTING LIGHT AIRCRAFT OPERATIONS OVER THESE AIRPORTS...WHILE CREATING MECHANICAL TURBULENCE OVER MANY RIDGE TOPS. MOUNTAIN OBSCURATIONS CAN ALSO BE EXPECTED OVER THE NORTHERN AND CENTRAL MOUNTAINS THROUGH THURSDAY MORNING BEFORE DRIER AIR WORKS IN AND LIFT MOVES INTO THE PLAINS. VFR CONDITIONS CAN BE EXPECTED OVER THE LOWER VALLEY TERMINALS OVER THE NEXT 24 HOURS. && .FIRE WEATHER... ISSUED AT 345 PM MDT WED MAY 23 2012 RED FLAG WARNING CONTINUES FOR SOUTHWEST AND PORTIONS OF WEST-CENTRAL CO THROUGH THIS EVENING. THURSDAY LOOKS LIKE A BIT OF DOWN DAY WITH SLIGHTLY WEAKER WINDS ALOFT AND AT THE SURFACE...THOUGH LOCALIZED BORDERLINE CRITICAL CONDITIONS WILL BE POSSIBLE IN SOUTHWEST CO. WINDY AND DRY CONDITIONS LOOK IN STORE FOR FRIDAY AND SATURDAY AS THE NEXT STORM DROPS INTO THE GREAT BASIN. THE FIRE WEATHER WATCH CURRENTLY STARTING FRIDAY AFTERNOON HAS NOW BEEN EXTENDED UNTIL SATURDAY EVENING. AM CONCERNED THAT WINDS WILL PERSIST FRIDAY NIGHT AT LEAST ACROSS THE MID-SLOPES AND THERMAL BELTS WHERE HUMIDITY RECOVERY MAY BE THE POOREST. DO NOT DOUBT THAT THERE WILL BE A PERIOD OF NON-CRITICAL CONDITIONS LATER FRIDAY NIGHT ESPECIALLY FOR VALLEYS...BUT WITH ANY VALLEY INVERSIONS BEING SHALLOW AND EASILY MIXED OUT...CRITICAL FIRE WEATHER CONDITIONS COULD RETURN AS EARLY AS MID-MORNING SATURDAY. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...RED FLAG WARNING UNTIL 11 PM MDT THIS EVENING FOR COZ207. FIRE WEATHER WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY EVENING FOR COZ200>203-207-290-292-293. WIND ADVISORY UNTIL 11 PM MDT THIS EVENING FOR COZ018-019- 021>023. UT...WIND ADVISORY UNTIL 11 PM MDT THIS EVENING FOR UTZ022. && $$ UPDATE...PF SHORT TERM...15 LONG TERM...JAD AVIATION...15 FIRE WEATHER...JAD
AREA FORECAST DISCUSSION
NWS TAUNTON MA
122 PM EDT TUE MAY 22 2012 .SYNOPSIS... LOW PRESSURE WILL PASS EAST OF CAPE COD THIS AFTERNOON. SOUTHEASTERLY FLOW OVER SOUTHERN NEW ENGLAND LATE THIS WEEK MAY RESULT IN SHOWERS AND THUNDERSTORMS. CHANCE FOR STORMS INCREASES SATURDAY AS A COLD FRONT APPROACHES THE AREA. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 10 AM UPDATE...THREE BANDS OF SHOWERS ON THE RADAR. ONE IS ACROSS SOUTHERN NH AND WESTERN MASS...THE SECOND IS SOUTHEAST MASS AND RI AND EASTERN CT...THE THIRD IS MOVING INTO THE ISLANDS. THESE ARE SLIDING NORTH-NORTHWEST. THE UPDATE GOES WITH LIKELY TO CATEGORICAL POPS ROUGHLY DRAWN TO MIRROR THESE BANDS. POPS DIMINISH TO CHANCE DURING THE AFTERNOON AS THE OFFSHORE LOW MOVES PAST. WINDS HAVE BEEN BLENDED WITH THE LATEST HRRR GUIDANCE. BASIC IDEA OF THE FORECAST REMAINS INTACT. ORIGINAL DISCUSSION... MID LEVEL CIRCULATION EAST OF NJ COAST WITH TROWAL SIGNATURE IN PLACE TO THE NORTH ACROSS NEW ENG. BANDS OF MAINLY LIGHT SHOWERS ARE LIFTING NORTH ACROSS SNE EARLY THIS MORNING. SFC REFLECTION IN THE FORM OF A WEAK WAVE IS FORECAST TO TRACK NE AND PASS E OF CAPE COD TODAY. WEAK EASTERLY LOW LEVEL JET ALONG WITH SOME INSTABILITY JUST OFFSHORE MAY HELP TO ENHANCE SHOWERS OVER THE CAPE/ISLANDS THROUGH THE MORNING. OTHERWISE...WILL CONTINUE WITH CHC SHOWERS AS MID LEVEL SHORTWAVE LIFTS NWD ACROSS THE REGION. EXPECT LOW CLOUDS TO PERSIST TODAY GIVEN ABUNDANT LOW LEVEL MOISTURE BUT IMPROVING VSBYS DURING THE DAY. USED A BLEND OF TRADITIONAL MOS GUIDANCE AND BIAS CORRECTED GRIDS FOR MAX TEMPS. COOLEST TEMPS WILL BE ACROSS E COASTAL MA WITH MILDEST READINGS IN THE CT VALLEY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... TONIGHT... MID LEVEL SHORTWAVE AND WEAK SFC WAVE EXIT TO THE EAST WITH WEAK SFC RIDGING DEVELOPING SO EXPECT MOSTLY DRY CONDITIONS. STILL CANT RULE OUT A BRIEF SHOWER OR PATCHY DRIZZLE GIVEN THE MOISTURE IN PLACE SO HAVE SLIGHT CHC POPS...BUT MOST OF THE NIGHT SHOULD BE DRY. WEDNESDAY... NEXT MID LEVEL LOW WILL MOVE TO THE SE US AND SOUTHERN MID ATLC REGION WITH RIDGING DEVELOPING TO THE NORTH INTO NEW ENG. HOWEVER...MODELS INDICATE MARGINAL SFC INSTABILITY DEVELOPING AS DEEP LAYER MOISTURE DECREASES A BIT WHICH MAY ALLOW FOR SOME BREAKS OF SUNSHINE DEVELOPING...ESPECIALLY INTERIOR. FORECAST CAPES 500-1000 J/KG AND LI/S -2 TO -3C SO WILL HAVE CHC SHOWERS/TSTMS. SVR WEATHER NOT ANTICIPATED GIVEN WEAK WIND FIELD AND MARGINAL MID LEVEL LAPSE RATES...BUT THIS WILL LEAD TO LOCALIZED HEAVY RAINFALL BEING A THREAT AS PWATS NEAR 1.5". USED A BLEND OF MAV/MET GUIDANCE FOR MAX TEMPS...MAINLY 75 TO 80 DEGREES...BUT COOLER ALONG THE COAST WHERE SEABREEZES ARE EXPECTED. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... * UNSETTLED WEATHER CONTINUES THROUGH THE END OF THE WEEK * TEMPERATURES ON A GRADUAL WARMING TREND THROUGH EARLY NEXT WEEK OVERVIEW... AGREEMENT AMONGST THE 00Z MODELS IS PRETTY DISMAL IN REGARDS TO TIMING. THE GFS IS 12 TO 24 HOURS FASTER THAN THE ECMWF WITH MOST FEATURES THROUGH THE PERIOD. OVERALL...AN UPPER RIDGE MOVES OFFSHORE THURSDAY FOLLOWED BY AN UPPER TROUGH MOVING ACROSS SOUTHERN NEW ENGLAND. ALL THIS OCCURS WITH HIGH PRESSURE OVER MAINE AND NOVA SCOTIA...PROVIDING A MOIST SOUTHEASTERLY FLOW. LOW PRESSURE MOVING THROUGH QUEBEC OVER THE WEEKEND BRINGS A COLD FRONT THROUGH SOUTHERN NEW ENGLAND SATURDAY. THERE ARE A FEW MORE DISCREPANCIES IN THE MODELS SUNDAY AND MONDAY. A WARM FRONT WILL ADVANCE NORTHWARD THROUGH THE REGION SOMETIME DURING THIS PERIOD...RESULTING IN WARMER TEMPERATURES AND ANOTHER SHOT OF RAIN. DETAILS... WEDNESDAY NIGHT INTO THURSDAY...CLOUDY AND UNSETTLED WEATHER IS EXPECTED THROUGH THIS PERIOD WITH THE BEST SHOT OF SHOWERS AND/OR THUNDERSTORMS ON THURSDAY AFTERNOON. DECENT MID LEVEL LAPSE RATES AND CONVECTIVE PARAMETERS INDICATE AN UNSTABLE ATMOSPHERE SO WILL KEEP CHANCE OF THUNDER IN THE GRIDS FOR THURSDAY AFTERNOON AND EVENING. USED A BLEND OF MOS FOR TEMPERATURES YIELDING TEMPERATURES SLIGHTLY ABOVE NORMAL IN THE MID TO UPPER 70S. WITH DEWPOINTS WELL INTO THE 50S AND EVEN INTO THE LOW 60S AT TIMES OVERNIGHT AND MOIST GROUND...EXPECT FOG TO DEVELOP OVERNIGHT. FRIDAY...SOUTHWEST SURFACE FLOW AHEAD OF A COLD FRONT TRAILING A LOW PRESSURE IN QUEBEC WILL YIELD ANOTHER DAY OF ABOVE NORMAL TEMPERATURES. ADDITIONALLY...SOUTHWEST WINDS WILL BRING IN MOISTURE AND HIGHER DEWPOINTS. SHOWERS ARE LIKELY TO FORM DIURNALLY WITH MODELS HINTING AT A POTENTIAL FOR THUNDER. SOMEWHAT UNCERTAIN AT THIS POINT SO HAVE LEFT THUNDER OUT OF THE GRIDS FOR THE TIME BEING. FOG IS POSSIBLE AGAIN DURING THE OVERNIGHT PERIOD. SATURDAY...LOW PRESSURE MAKES ITS WAY ACROSS QUEBEC BRINGING A COLD FRONT ACROSS SOUTHERN NEW ENGLAND AT SOME POINT SATURDAY. THERE IS SOME DIFFERENCE BETWEEN THE MODELS ON TIMING FOR THIS. AHEAD OF THE FRONT...MID LEVEL LAPSE RATES INCREASE AND SOUTHWEST FLOW AT THE SURFACE WILL BRING IN HIGHER DEWPOINTS. THIS WILL LIKELY RESULT IN WIDESPREAD SHOWERS. AGAIN...THUNDER IS A POSSIBILITY WITH THESE SHOWERS...BUT THIS BEING DAY 5 AND THERE REMAINING SOME UNCERTAINTY HERE...WILL LEAVE OUT OF THE GRIDS. SUNDAY AND MONDAY...MOST MODEL DISCREPANCIES EXIST HERE. THERE IS SOME INDICATION OF GRADUALLY WARMING TEMPERATURES THROUGH THE HOLIDAY WEEKEND. ECMWF SHOWS A SLIGHT COOL OFF SUNDAY BUT REBOUNDING MONDAY WHILE THE GFS HAS TEMPS WARMING THROUGH THIS PERIOD. A WARM FRONT WILL MOVE THROUGH THE REGION DURING THIS TIME BRINGING WARM...MOIST AIR INTO THE AREA AND PRODUCING SHOWERS AND POSSIBLY THUNDERSTORMS. && .AVIATION /17Z TUESDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT MODERATE...30 PERCENT TO 60 PERCENT HIGH...GREATER THAN 60 PERCENT OVERVIEW... MODERATE CONFIDENCE IN TAFS. PERSISTENT N/NE FLOW WILL KEEP LOW CIGS LOCKED IN THROUGH WED MORNING AND AREAS OF FOG EXPECTED TO BECOME WIDESPREAD AGAIN THIS EVENING. CIGS WILL BE SLOW TO IMPROVE WED BUT AM CONFIDENT ON IMPROVEMENT TO VFR AROUND MIDDAY...EXCEPT ON OUTER CAPE COD AND KACK WHERE LOW CIGS WILL PROBABLY REMAIN ALL DAY. WEAK GRADIENT WILL BRING RETURN OF LOW CLOUDS/FOG WED NIGHT... ESPECIALLY NEAR COAST. KBOS TAF...MODERATE CONFIDENCE. TIMING OF LOWEST CONDITIONS TONIGHT MAY BE A FEW HOURS TOO FAST. HIGHER CONFIDENCE ON TIMING OF IMPROVEMENT WED. KBDL TAF...MODERATE CONFIDENCE. TIMING OF IFR CIGS MAY BE A FEW HOURS TOO FAST TONIGHT. HIGHER CONFIDENCE ON TIMING OF IMPROVEMENT WED. OUTLOOK...THURSDAY THOUGH SATURDAY... THURSDAY THROUGH SATURDAY...LOW TO MODERATE CONFIDENCE. DAYTIME GENERALLY VFR WITH PERIODS OF MVFR IN SHOWERS AND POSSIBLE TSRA. NIGHTTIME MVFR WITH PERIODS OF IFR IN FOG. && .MARINE... MODERATE TO HIGH CONFIDENCE THROUGH WEDNESDAY. WINDS WILL REMAIN WELL BELOW SCA THRESHOLDS...BUT INCREASING SE SWELL WILL RESULT IN SEAS BUILDING TO 5-7 FT OVER THE S COASTAL WATERS. WNAWAVE GUIDANCE HAS BEEN OVERDONE ON SEAS SO WE USED MORE CONSERVATIVE SWAN NAM. SCA FOR HAZARDOUS SEAS WILL CONTINUE. OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY... SEAS REMAIN BELOW 5 FEET THROUGH THE PERIOD WITH HIGH PRESSURE OVER MAINE AND THE MARITIMES. SIMILARLY WINDS WILL REMAIN GENERALLY OUT OF THE SOUTH AND BELOW 25 KTS. HIGH CONFIDENCE IN FOG REDUCING VISIBILITIES AT TIMES...MOSTLY DURING THE OVERNIGHT PERIODS. SHOWERS AND THUNDERSTORMS ARE A LOW PROBABILITY EACH AFTERNOON AND EVENING. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT WEDNESDAY FOR ANZ235-237-254>256. && $$ SYNOPSIS...KJC NEAR TERM...WTB/KJC SHORT TERM...KJC LONG TERM...RLG AVIATION...JWD MARINE...KJC/RLG
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1020 AM EDT TUE MAY 22 2012 .SYNOPSIS... LOW PRESSURE WILL PASS EAST OF CAPE COD THIS AFTERNOON. SOUTHEASTERLY FLOW OVER SOUTHERN NEW ENGLAND LATE THIS WEEK MAY RESULT IN SHOWERS AND THUNDERSTORMS. CHANCE FOR STORMS INCREASES SATURDAY AS A COLD FRONT APPROACHES THE AREA. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 10 AM UPDATE...THREE BANDS OF SHOWERS ON THE RADAR. ONE IS ACROSS SOUTHERN NH AND WESTERN MASS...THE SECOND IS SOUTHEAST MASS AND RI AND EASTERN CT...THE THIRD IS MOVING INTO THE ISLANDS. THESE ARE SLIDING NORTH-NORTHWEST. THE UPDATE GOES WITH LIKELY TO CATEGORICAL POPS ROUGHLY DRAWN TO MIRROR THESE BANDS. POPS DIMINISH TO CHANCE DURING THE AFTERNOON AS THE OFFSHORE LOW MOVES PAST. WINDS HAVE BEEN BLENDED WITH THE LATEST HRRR GUIDANCE. BASIC IDEA OF THE FORECAST REMAINS INTACT. ORIGINAL DISCUSSION... MID LEVEL CIRCULATION EAST OF NJ COAST WITH TROWAL SIGNATURE IN PLACE TO THE NORTH ACROSS NEW ENG. BANDS OF MAINLY LIGHT SHOWERS ARE LIFTING NORTH ACROSS SNE EARLY THIS MORNING. SFC REFLECTION IN THE FORM OF A WEAK WAVE IS FORECAST TO TRACK NE AND PASS E OF CAPE COD TODAY. WEAK EASTERLY LOW LEVEL JET ALONG WITH SOME INSTABILITY JUST OFFSHORE MAY HELP TO ENHANCE SHOWERS OVER THE CAPE/ISLANDS THROUGH THE MORNING. OTHERWISE...WILL CONTINUE WITH CHC SHOWERS AS MID LEVEL SHORTWAVE LIFTS NWD ACROSS THE REGION. EXPECT LOW CLOUDS TO PERSIST TODAY GIVEN ABUNDANT LOW LEVEL MOISTURE BUT IMPROVING VSBYS DURING THE DAY. USED A BLEND OF TRADITIONAL MOS GUIDANCE AND BIAS CORRECTED GRIDS FOR MAX TEMPS. COOLEST TEMPS WILL BE ACROSS E COASTAL MA WITH MILDEST READINGS IN THE CT VALLEY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... TONIGHT... MID LEVEL SHORTWAVE AND WEAK SFC WAVE EXIT TO THE EAST WITH WEAK SFC RIDGING DEVELOPING SO EXPECT MOSTLY DRY CONDITIONS. STILL CANT RULE OUT A BRIEF SHOWER OR PATCHY DRIZZLE GIVEN THE MOISTURE IN PLACE SO HAVE SLIGHT CHC POPS...BUT MOST OF THE NIGHT SHOULD BE DRY. WEDNESDAY... NEXT MID LEVEL LOW WILL MOVE TO THE SE US AND SOUTHERN MID ATLC REGION WITH RIDGING DEVELOPING TO THE NORTH INTO NEW ENG. HOWEVER...MODELS INDICATE MARGINAL SFC INSTABILITY DEVELOPING AS DEEP LAYER MOISTURE DECREASES A BIT WHICH MAY ALLOW FOR SOME BREAKS OF SUNSHINE DEVELOPING...ESPECIALLY INTERIOR. FORECAST CAPES 500-1000 J/KG AND LI/S -2 TO -3C SO WILL HAVE CHC SHOWERS/TSTMS. SVR WEATHER NOT ANTICIPATED GIVEN WEAK WIND FIELD AND MARGINAL MID LEVEL LAPSE RATES...BUT THIS WILL LEAD TO LOCALIZED HEAVY RAINFALL BEING A THREAT AS PWATS NEAR 1.5". USED A BLEND OF MAV/MET GUIDANCE FOR MAX TEMPS...MAINLY 75 TO 80 DEGREES...BUT COOLER ALONG THE COAST WHERE SEABREEZES ARE EXPECTED. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... * UNSETTLED WEATHER CONTINUES THROUGH THE END OF THE WEEK * TEMPERATURES ON A GRADUAL WARMING TREND THROUGH EARLY NEXT WEEK OVERVIEW... AGREEMENT AMONGST THE 00Z MODELS IS PRETTY DISMAL IN REGARDS TO TIMING. THE GFS IS 12 TO 24 HOURS FASTER THAN THE ECMWF WITH MOST FEATURES THROUGH THE PERIOD. OVERALL...AN UPPER RIDGE MOVES OFFSHORE THURSDAY FOLLOWED BY AN UPPER TROUGH MOVING ACROSS SOUTHERN NEW ENGLAND. ALL THIS OCCURS WITH HIGH PRESSURE OVER MAINE AND NOVA SCOTIA...PROVIDING A MOIST SOUTHEASTERLY FLOW. LOW PRESSURE MOVING THROUGH QUEBEC OVER THE WEEKEND BRINGS A COLD FRONT THROUGH SOUTHERN NEW ENGLAND SATURDAY. THERE ARE A FEW MORE DISCREPANCIES IN THE MODELS SUNDAY AND MONDAY. A WARM FRONT WILL ADVANCE NORTHWARD THROUGH THE REGION SOMETIME DURING THIS PERIOD...RESULTING IN WARMER TEMPERATURES AND ANOTHER SHOT OF RAIN. DETAILS... WEDNESDAY NIGHT INTO THURSDAY...CLOUDY AND UNSETTLED WEATHER IS EXPECTED THROUGH THIS PERIOD WITH THE BEST SHOT OF SHOWERS AND/OR THUNDERSTORMS ON THURSDAY AFTERNOON. DECENT MID LEVEL LAPSE RATES AND CONVECTIVE PARAMETERS INDICATE AN UNSTABLE ATMOSPHERE SO WILL KEEP CHANCE OF THUNDER IN THE GRIDS FOR THURSDAY AFTERNOON AND EVENING. USED A BLEND OF MOS FOR TEMPERATURES YIELDING TEMPERATURES SLIGHTLY ABOVE NORMAL IN THE MID TO UPPER 70S. WITH DEWPOINTS WELL INTO THE 50S AND EVEN INTO THE LOW 60S AT TIMES OVERNIGHT AND MOIST GROUND...EXPECT FOG TO DEVELOP OVERNIGHT. FRIDAY...SOUTHWEST SURFACE FLOW AHEAD OF A COLD FRONT TRAILING A LOW PRESSURE IN QUEBEC WILL YIELD ANOTHER DAY OF ABOVE NORMAL TEMPERATURES. ADDITIONALLY...SOUTHWEST WINDS WILL BRING IN MOISTURE AND HIGHER DEWPOINTS. SHOWERS ARE LIKELY TO FORM DIURNALLY WITH MODELS HINTING AT A POTENTIAL FOR THUNDER. SOMEWHAT UNCERTAIN AT THIS POINT SO HAVE LEFT THUNDER OUT OF THE GRIDS FOR THE TIME BEING. FOG IS POSSIBLE AGAIN DURING THE OVERNIGHT PERIOD. SATURDAY...LOW PRESSURE MAKES ITS WAY ACROSS QUEBEC BRINGING A COLD FRONT ACROSS SOUTHERN NEW ENGLAND AT SOME POINT SATURDAY. THERE IS SOME DIFFERENCE BETWEEN THE MODELS ON TIMING FOR THIS. AHEAD OF THE FRONT...MID LEVEL LAPSE RATES INCREASE AND SOUTHWEST FLOW AT THE SURFACE WILL BRING IN HIGHER DEWPOINTS. THIS WILL LIKELY RESULT IN WIDESPREAD SHOWERS. AGAIN...THUNDER IS A POSSIBILITY WITH THESE SHOWERS...BUT THIS BEING DAY 5 AND THERE REMAINING SOME UNCERTAINTY HERE...WILL LEAVE OUT OF THE GRIDS. SUNDAY AND MONDAY...MOST MODEL DISCREPANCIES EXIST HERE. THERE IS SOME INDICATION OF GRADUALLY WARMING TEMPERATURES THROUGH THE HOLIDAY WEEKEND. ECMWF SHOWS A SLIGHT COOL OFF SUNDAY BUT REBOUNDING MONDAY WHILE THE GFS HAS TEMPS WARMING THROUGH THIS PERIOD. A WARM FRONT WILL MOVE THROUGH THE REGION DURING THIS TIME BRINGING WARM...MOIST AIR INTO THE AREA AND PRODUCING SHOWERS AND POSSIBLY THUNDERSTORMS. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT MODERATE...30 PERCENT TO 60 PERCENT HIGH...GREATER THAN 60 PERCENT OVERVIEW... MODERATE CONFIDENCE IN TAFS. IFR/LIFR EXPECTED TO PREVAIL THROUGH AFTERNOON NEAR COAST...WHILE CONDITIONS LOWER TO IFR ACROSS INTERIOR. NOT MUCH HOPE FOR CIGS TO IMPROVE GIVEN CONTINUED ONSHORE FLOW. KBOS TAF...HIGH CONFIDENCE IN LIFR CONDITIONS THROUGH AFTERNOON. KBDL TAF...HIGH CONFIDENCE IN CONDITIONS LOWERING TO IFR THIS AFTERNOON. OUTLOOK...WEDNESDAY NIGHT THOUGH SATURDAY... WEDNESDAY NIGHT...LOW CONFIDENCE. MVFR WITH POCKETS OF IFR IN FOG ALONG SOUTH COAST. THURSDAY THROUGH SATURDAY...LOW TO MODERATE CONFIDENCE. DAYTIME GENERALLY VFR WITH PERIODS OF MVFR IN SHOWERS AND POSSIBLE TSRA. NIGHTTIME MVFR WITH PERIODS OF IFR IN FOG. && .MARINE... MODERATE TO HIGH CONFIDENCE THROUGH WEDNESDAY. WINDS WILL REMAIN WELL BELOW SCA THRESHOLDS...BUT INCREASING SE SWELL WILL RESULT IN SEAS BUILDING TO 5-7 FT OVER THE S COASTAL WATERS. WNAWAVE GUIDANCE HAS BEEN OVERDONE ON SEAS SO WE USED MORE CONSERVATIVE SWAN NAM. SCA FOR HAZARDOUS SEAS WILL CONTINUE. OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY... SEAS REMAIN BELOW 5 FEET THROUGH THE PERIOD WITH HIGH PRESSURE OVER MAINE AND THE MARITIMES. SIMILARLY WINDS WILL REMAIN GENERALLY OUT OF THE SOUTH AND BELOW 25 KTS. HIGH CONFIDENCE IN FOG REDUCING VISIBILITIES AT TIMES...MOSTLY DURING THE OVERNIGHT PERIODS. SHOWERS AND THUNDERSTORMS ARE A LOW PROBABILITY EACH AFTERNOON AND EVENING. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT WEDNESDAY FOR ANZ235-237-254>256. && $$ SYNOPSIS...KJC NEAR TERM...WTB/KJC SHORT TERM...KJC LONG TERM...RLG AVIATION...JWD MARINE...KJC/RLG
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1012 AM EDT TUE MAY 22 2012 .SYNOPSIS... LOW PRESSURE WILL PASS EAST OF CAPE COD THIS AFTERNOON. SOUTHEASTERLY FLOW OVER SOUTHERN NEW ENGLAND LATE THIS WEEK MAY RESULT IN SHOWERS AND THUNDERSTORMS. CHANCE FOR STORMS INCREASES SATURDAY AS A COLD FRONT APPROACHES THE AREA. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 10 AM UPDATE...THREE BANDS OF SHOWERS ON THE RADAR. ONE IS ACROSS SOUTHERN NH AND WESTERN MASS...THE SECOND IS SOUTHEAST MASS AND RI AND EASTERN CT...THE THIRD IS MOVING INTO THE ISLANDS. THESE ARE SLIDING NORTH-NORTHWEST. THE UPDATE GOES WITH LIKELY TO CATEGORICAL POPS ROUGHLY DRAWN TO MIRROR THESE BANDS. POPS DIMINISH TO CHANCE DURING THE AFTERNOON AS THE OFFSHORE LOW MOVES PAST. WINDS HAVE BEEN BLENDED WITH THE LATEST HRRR GUIDENCE. BASIC IDEA OF THE FORECAST REMAINS INTACT. ORIGINAL DISCUSSION... MID LEVEL CIRCULATION EAST OF NJ COAST WITH TROWAL SIGNATURE IN PLACE TO THE NORTH ACROSS NEW ENG. BANDS OF MAINLY LIGHT SHOWERS ARE LIFTING NORTH ACROSS SNE EARLY THIS MORNING. SFC REFLECTION IN THE FORM OF A WEAK WAVE IS FORECAST TO TRACK NE AND PASS E OF CAPE COD TODAY. WEAK EASTERLY LOW LEVEL JET ALONG WITH SOME INSTABILITY JUST OFFSHORE MAY HELP TO ENHANCE SHOWERS OVER THE CAPE/ISLANDS THROUGH THE MORNING. OTHERWISE...WILL CONTINUE WITH CHC SHOWERS AS MID LEVEL SHORTWAVE LIFTS NWD ACROSS THE REGION. EXPECT LOW CLOUDS TO PERSIST TODAY GIVEN ABUNDANT LOW LEVEL MOISTURE BUT IMPROVING VSBYS DURING THE DAY. USED A BLEND OF TRADITIONAL MOS GUIDANCE AND BIAS CORRECTED GRIDS FOR MAX TEMPS. COOLEST TEMPS WILL BE ACROSS E COASTAL MA WITH MILDEST READINGS IN THE CT VALLEY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... TONIGHT... MID LEVEL SHORTWAVE AND WEAK SFC WAVE EXIT TO THE EAST WITH WEAK SFC RIDGING DEVELOPING SO EXPECT MOSTLY DRY CONDITIONS. STILL CANT RULE OUT A BRIEF SHOWER OR PATCHY DRIZZLE GIVEN THE MOISTURE IN PLACE SO HAVE SLIGHT CHC POPS...BUT MOST OF THE NIGHT SHOULD BE DRY. WEDNESDAY... NEXT MID LEVEL LOW WILL MOVE TO THE SE US AND SOUTHERN MID ATLC REGION WITH RIDGING DEVELOPING TO THE NORTH INTO NEW ENG. HOWEVER...MODELS INDICATE MARGINAL SFC INSTABILITY DEVELOPING AS DEEP LAYER MOISTURE DECREASES A BIT WHICH MAY ALLOW FOR SOME BREAKS OF SUNSHINE DEVELOPING...ESPECIALLY INTERIOR. FORECAST CAPES 500-1000 J/KG AND LI/S -2 TO -3C SO WILL HAVE CHC SHOWERS/TSTMS. SVR WEATHER NOT ANTICIPATED GIVEN WEAK WIND FIELD AND MARGINAL MID LEVEL LAPSE RATES...BUT THIS WILL LEAD TO LOCALIZED HEAVY RAINFALL BEING A THREAT AS PWATS NEAR 1.5". USED A BLEND OF MAV/MET GUIDANCE FOR MAX TEMPS...MAINLY 75 TO 80 DEGREES...BUT COOLER ALONG THE COAST WHERE SEABREEZES ARE EXPECTED. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... * UNSETTLED WEATHER CONTINUES THROUGH THE END OF THE WEEK * TEMPERATURES ON A GRADUAL WARMING TREND THROUGH EARLY NEXT WEEK OVERVIEW... AGREEMENT AMONGST THE 00Z MODELS IS PRETTY DISMAL IN REGARDS TO TIMING. THE GFS IS 12 TO 24 HOURS FASTER THAN THE ECMWF WITH MOST FEATURES THROUGH THE PERIOD. OVERALL...AN UPPER RIDGE MOVES OFFSHORE THURSDAY FOLLOWED BY AN UPPER TROUGH MOVING ACROSS SOUTHERN NEW ENGLAND. ALL THIS OCCURS WITH HIGH PRESSURE OVER MAINE AND NOVA SCOTIA...PROVIDING A MOIST SOUTHEASTERLY FLOW. LOW PRESSURE MOVING THROUGH QUEBEC OVER THE WEEKEND BRINGS A COLD FRONT THROUGH SOUTHERN NEW ENGLAND SATURDAY. THERE ARE A FEW MORE DISCREPANCIES IN THE MODELS SUNDAY AND MONDAY. A WARM FRONT WILL ADVANCE NORTHWARD THROUGH THE REGION SOMETIME DURING THIS PERIOD...RESULTING IN WARMER TEMPERATURES AND ANOTHER SHOT OF RAIN. DETAILS... WEDNESDAY NIGHT INTO THURSDAY...CLOUDY AND UNSETTLED WEATHER IS EXPECTED THROUGH THIS PERIOD WITH THE BEST SHOT OF SHOWERS AND/OR THUNDERSTORMS ON THURSDAY AFTERNOON. DECENT MID LEVEL LAPSE RATES AND CONVECTIVE PARAMETERS INDICATE AN UNSTABLE ATMOSPHERE SO WILL KEEP CHANCE OF THUNDER IN THE GRIDS FOR THURSDAY AFTERNOON AND EVENING. USED A BLEND OF MOS FOR TEMPERATURES YIELDING TEMPERATURES SLIGHTLY ABOVE NORMAL IN THE MID TO UPPER 70S. WITH DEWPOINTS WELL INTO THE 50S AND EVEN INTO THE LOW 60S AT TIMES OVERNIGHT AND MOIST GROUND...EXPECT FOG TO DEVELOP OVERNIGHT. FRIDAY...SOUTHWEST SURFACE FLOW AHEAD OF A COLD FRONT TRAILING A LOW PRESSURE IN QUEBEC WILL YIELD ANOTHER DAY OF ABOVE NORMAL TEMPERATURES. ADDITIONALLY...SOUTHWEST WINDS WILL BRING IN MOISTURE AND HIGHER DEWPOINTS. SHOWERS ARE LIKELY TO FORM DIURNALLY WITH MODELS HINTING AT A POTENTIAL FOR THUNDER. SOMEWHAT UNCERTAIN AT THIS POINT SO HAVE LEFT THUNDER OUT OF THE GRIDS FOR THE TIME BEING. FOG IS POSSIBLE AGAIN DURING THE OVERNIGHT PERIOD. SATURDAY...LOW PRESSURE MAKES ITS WAY ACROSS QUEBEC BRINGING A COLD FRONT ACROSS SOUTHERN NEW ENGLAND AT SOME POINT SATURDAY. THERE IS SOME DIFFERENCE BETWEEN THE MODELS ON TIMING FOR THIS. AHEAD OF THE FRONT...MID LEVEL LAPSE RATES INCREASE AND SOUTHWEST FLOW AT THE SURFACE WILL BRING IN HIGHER DEWPOINTS. THIS WILL LIKELY RESULT IN WIDESPREAD SHOWERS. AGAIN...THUNDER IS A POSSIBILITY WITH THESE SHOWERS...BUT THIS BEING DAY 5 AND THERE REMAINING SOME UNCERTAINTY HERE...WILL LEAVE OUT OF THE GRIDS. SUNDAY AND MONDAY...MOST MODEL DISCREPANCIES EXIST HERE. THERE IS SOME INDICATION OF GRADUALLY WARMING TEMPERATURES THROUGH THE HOLIDAY WEEKEND. ECMWF SHOWS A SLIGHT COOL OFF SUNDAY BUT REBOUNDING MONDAY WHILE THE GFS HAS TEMPS WARMING THROUGH THIS PERIOD. A WARM FRONT WILL MOVE THROUGH THE REGION DURING THIS TIME BRINGING WARM...MOIST AIR INTO THE AREA AND PRODUCING SHOWERS AND POSSIBLY THUNDERSTORMS. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT MODERATE...30 PERCENT TO 60 PERCENT HIGH...GREATER THAN 60 PERCENT OVERVIEW... MODERATE CONFIDENCE IN TAFS. IFR/LIFR CONDITIONS WILL LIKELY PREVAIL FOR MUCH OF THE REGION THROUGH THE MORNING...POSSIBLY LIFTING TO MVFR IN THE INTERIOR DURING THE AFTERNOON. CONDITIONS DROPPING BACK TO IFR/LIFR TONIGHT BUT FOG MAY NOT BE AS DENSE AND WIDESPREAD AS LOW LEVEL WINDS TURN S/SW. GRADUAL IMPROVEMENT TO VFR/MVFR EXPECTED DURING WED WITH SCT SHOWERS/TSTMS POSSIBLE...BUT MVFR/IFR CIGS COULD LINGER ALONG THE S COAST ALL DAY WED. KBOS TAF...HIGH CONFIDENCE IN LIFR CONDITIONS THROUGH 14Z...THEN IMPROVING VSBYS EXPECTED DURING THE DAY BUT CIGS LIKELY REMAINING IFR THROUGH TONIGHT. KBDL TAF...MODERATE CONFIDENCE. AREAS OF MVFR. CIGS MAY DROP BACK TO IFR LATE TONIGHT. OUTLOOK...WEDNESDAY NIGHT THOUGH SATURDAY... WEDNESDAY NIGHT...LOW CONFIDENCE. MVFR WITH POCKETS OF IFR IN FOG ALONG SOUTH COAST. THURSDAY THROUGH SATURDAY...LOW TO MODERATE CONFIDENCE. DAYTIME GENERALLY VFR WITH PERIODS OF MVFR IN SHOWERS AND POSSIBLE TSRA. NIGHTTIME MVFR WITH PERIODS OF IFR IN FOG. && .MARINE... MODERATE TO HIGH CONFIDENCE THROUGH WEDNESDAY. WINDS WILL REMAIN WELL BELOW SCA THRESHOLDS...BUT INCREASING SE SWELL WILL RESULT IN SEAS BUILDING TO 5-7 FT OVER THE S COASTAL WATERS. WNAWAVE GUIDANCE HAS BEEN OVERDONE ON SEAS SO WE USED MORE CONSERVATIVE SWAN NAM. SCA FOR HAZARDOUS SEAS WILL CONTINUE. OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY... SEAS REMAIN BELOW 5 FEET THROUGH THE PERIOD WITH HIGH PRESSURE OVER MAINE AND THE MARITIMES. SIMILARLY WINDS WILL REMAIN GENERALLY OUT OF THE SOUTH AND BELOW 25 KTS. HIGH CONFIDENCE IN FOG REDUCING VISIBILITIES AT TIMES...MOSTLY DURING THE OVERNIGHT PERIODS. SHOWERS AND THUNDERSTORMS ARE A LOW PROBABILITY EACH AFTERNOON AND EVENING. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT WEDNESDAY FOR ANZ235-237-254>256. && $$ SYNOPSIS...KJC NEAR TERM...WTB/KJC SHORT TERM...KJC LONG TERM...RLG AVIATION...KJC/RLG MARINE...KJC/RLG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
611 PM EDT TUE MAY 22 2012 .SYNOPSIS... A LOW PRESSURE SYSTEM SOUTHEAST OF CAPE COD WILL DRIFT NORTHEAST TONIGHT AND WEDNESDAY. A HIGH PRESSURE SYSTEM WILL THEN BUILD IN BEHIND IT OVER THE CANADIAN MARITIMES ON THURSDAY AND SLOWLY SINK SOUTHWEST OVER THE MEMORIAL DAY WEEKEND AND BECOME ESTABLISHED OFF THE SOUTHEAST UNITED STATES COAST. A BACKDOOR COLD FRONT WILL TRY TO SAG SOUTH INTO THE AREA ABOUT SUNDAY BEFORE RETREATING NORTH ON MEMORIAL DAY. A FRONT DOOR COLD FRONT WILL APPROACH THE AREA FROM THE GREAT LAKES ON TUESDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... DESPITE BREAKS IN THE CLOUDS THIS AFTERNOON...THE SCATTERED SHOWER ACTIVITY HAS BEEN SLOW TO EVOLVE LATE THIS AFTERNOON. IN FACT...TOPS HAVE NOT GOTTEN TO MINUS 20 CELSIUS YET...AND THIS WOULD SEEM TO EXPLAIN THE LACK OF LIGHTNING DATA TO THIS POINT. THE LOSS OF DAYTIME HEATING SOON PROBABLY MEANS THE WINDOW OF OPPORTUNITY FOR THUNDER WITH THE SCATTERED SHOWERS DEVELOPING NOW IS CLOSING...AND COULD BE REMOVED FROM NORTHERN ZONES BEFORE 900 PM. THE LATEST HRRR RUN IS TRYING TO DEVELOP A BROKEN LINE OF THUNDERSTORMS IN THE BEST INSTABILITY. THIS LIES ACROSS WEST CENTRAL PENNSYLVANIA (WHERE THE SUNSHINE HAD A BETTER CHANCE TO DESTABILIZE THE AIRMASS. THE IN SITU BULK SHEAR PROFILE IS NOT THAT IMPRESSIVE...AND DOES NOT APPEAR TO GET ANY BETTER INTO THE LATER EVENING HOURS. WHILE THERE IS SOME ACTIVITY NOW IN THE AXIS OF BEST INSTABILITY...IT IS UNCLEAR JUST HOW MUCH OF THIS ACTIVITY SURVIVES TO THE LEHIGH VALLEY AFTER 800 PM. FOR NOW...WILL LEAVE THE MENTION OF THUNDER IN DEFERENCE TO THE ACTIVITY TO THE WEST. HOWEVER...IF IT DOES NOT GET BETTER ORGANIZED AS IT MOVES EAST...IT COULD BE REMOVED FROM THE FORECAST LATER TONIGHT. THE NEXT FORECAST PROBLEM FOR TONIGHT IS THE LOW CLOUDS AND FOG. THE LOW CLOUDS DID BREAK THIS AFTERNOON...AND PATCHES ARE TRYING TO REFORM EARLY THIS EVENING. NAM MODEL SOUNDINGS SHOW THAT THE REDEVELOPMENT OF STRATUS COULD TAKE SOME TIME...ESPECIALLY WEST OF THE DELAWARE RIVER. BASED ON THE CURRENT CLOUD COVER AND THE NAM MODEL SOUNDINGS...THE TIMING OF THE STRATUS REAPPEARANCE HAS BEEN PUSHED BACK A BIT. STATISTICAL GUIDANCE SUGGESTS THAT TONIGHT COULD END UP BEING A A BETTER SETUP FOR AREAS OF FOG (MOIST LOW LEVELS...HIGH PRESSURE TO THE NORTHEAST). HOWEVER...NAM MODEL SOUNDINGS SUGGEST THE THE LOW LEVEL HYDROLAPSE RATES DO NOT BECOME FAVORABLE FOR UNTIL LATER TONIGHT...AND FOR A SHORTER TIME THAT THE MOS GUIDANCE WOULD INDICATE. AREAS OF FOG WAS LEFT IN THE FORECAST...AND TRENDS WILL BE WATCHED TO LOOK FOR POTENTIAL FOR DENSE FOG LATER TONIGHT. FOR THE MOST PART...TEMPERATURES AND WINDS APPEAR TO BE ON TRACK FOR THE OVERNIGHT. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/... EXPECT PERIODS OF SHOWERS AND POSSIBLY THUNDERSTORMS DURG THE AFTN AND THEY MAY BE MORE WIDESPREAD THAN TODAY ESPECIALLY IF WE GET MORE BREAKS IN THE CLOUDS, BUT DON`T SEE ANY SIGNIFICANT FORCING MECHANISMS. GUID TEMPS LOOK REASONABLE ONCE AGAIN. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... THE WRF-NMMB INITIALIZATION WAS BETTER THAN THE GFS OFF OF THE 12Z SOUNDINGS AND THE FORMER WAS GIVEN MORE WEIGHT THAN AVERAGE TODAY. BTW TODAY IS THE FIRST DAY OF THE NEW GFS. IN THE BIG PICTURE, NO CHANGES TO OUR THINKING WITH MAINLY DIURNALLY DRIVEN LOCALIZED HEAVY RAIN CONVECTION INTO FRIDAY. THEN MODEL UNCERTAINTIES AS TO THE BACKDOOR ON THE WEEKEND WITH THE TREND TOWARD WARMER AND MORE HUMID WEATHER INCORPORATED. THERE SHOULD BE A DIURNAL DOWNTREND IN THE CONVECTION ON WEDNESDAY EVENING AS FORECAST CAPES AND LI(S) DECREASE. WE DID SHOW AN UPTICK IN POPS LATER AT NIGHT AS THE SHORT WAVE ASSOCIATED WITH THE CLOSING SERN CONUS LOW COMES CLOSE TO THE AREA. BOTH THE GFS AND WRF-NMMB DO SHOW SOME WEAK SFC BASED INSTABILITY AS THIS FEATURE SLIDES BY AND WE MENTION SOME THUNDER LATE. GIVEN THE CONTINUED UPTICK IN DEW POINTS, WE MAINTAINED THE MENTION OF PATCHY FOG LATE. A STAT GUIDANCE COMPROMISE WAS USED FOR MINS. ON THURSDAY, WE LEANED MORE TOWARD THE WRF-NMMB SOLUTION OF GIVING THE CANADIAN MARITIMES HIGH A BIT MORE OF A BITE AND SHELTERING OF OUR CWA FROM CONVECTION. IN REALITY GFS MOS SUPPORTS THE WRF-NMMB SFC FEATURES MORE SO THAN THE GFS ITSELF. BOTH WOULD FAVOR MORE ACTIVITY WEST VS EAST. CONCEIVABLY BEING RIGHT FOR THE WRONG REASON, THE GFS BRINGS IN DRY AIR ALOFT IN THE EAST DURING THE DAY ON THURSDAY WHICH WOULD MAKE IT HARDER FOR CONVECTION TO OCCUR. WITHOUT ANY ORGANIZED TRIGGER WITH THE AFOREMENTIONED SHORT WAVE MOVING FARTHER OFFSHORE IN THE MORNING, KEPT POPS AS CHANCE. GIVEN MORE OF AN ONSHORE INFLUENCE FROM THE SFC HIGH AND HOW LONG WILL IT TAKE TO CLEAR LOW CLOUDS, WE LEANED MAX TEMPS MUCH CLOSER TO THE LOWER NAM MOS THAN GFS MOS. WASH, RINSE, REPEAT ON THURSDAY NIGHT. BUT, WITHOUT A LATE SHORT WAVE, WE DROPPED POPS AS THE NIGHT PROGRESSES AND REMOVED THE MENTION OF THUNDER. THE WRF-NMMB SOLUTION SUPPORTS STRATUS AT THE LEAST AND A SUGGESTION OF DRIZZLE AT THE MOST AS THE .01 PCPN FIELD BOOMS LATE AT NIGHT. FOR NOW WE WENT THE PATCHY FOG ROUTE AND ACCEPTED THE STAT GUIDANCE MINS. ON FRIDAY, THE MODELS AGREE ON A SLIGHTLY MORE EAST PUSH IN THE INSTABILITY AXIS, MAYBE INTO THE DELAWARE VALLEY. OTHER THAN MESOSCALE FEATURES, I.E. DIFFERENTIAL HEATING, OROGRAPHIC LIFTING, MAYBE SEA OR BAY BREEZES, NOT MUCH ORGANIZATIONAL ACTIVITY EXPECTED AGAIN. POPS WERE AGAIN KEPT BELOW LIKELY. WE STILL PREFER MORE OF A MODIFIED MARINE INFLUENCE FROM OUR SURFACE HIGH TO THE EAST THAN THE GFS SHOWED AND WE THUS KEPT MAX TEMPS BLO MEX MOS. BOTH THE GFS AND WRF-NMMB DID SHOW AN AXIS OF HIGHER INSTABILITY WORKING ITS WAY INTO WESTERN PA DURING THE DAY ON FRIDAY. IF THE CONVECTION COULD MAINTAIN ITSELF, IT WOULD GET INTO OUR CWA BEFORE RUNNING OUT OF GAS ON FRIDAY NIGHT. WE DID UP POPS SLIGHTLY. THERE REMAINS SOME UNCERTAINTY AS TO HOW SOUTH WILL THE BACKDOOR FRONT GET OVER THE WEEKEND. RIGHT NOW IT APPEARS TO BE A DIFFERENCE BETWEEN WARM WEATHER AND SOME TYPICAL SUMMERTIME CONVECTION AROUND BECAUSE OF THE LINGERING FRONT, OR A COUPLE OF WARM SECTOR DAYS WITH HIGH TEMPERATURES REACHING THE 90S ON THE COASTAL PLAIN AWAY FROM THE OCEAN. THE MODELS CONTINUE TO GO BACK AND FORTH WITH THIS SCENARIO. MORE CONSENSUS ODDLY ABOUT HOT WEATHER ON MONDAY AND TUESDAY. WE NUDGED MAX TEMPS UPWARD WITH THIS PACKAGE AND MAINTAINED LOW POPS BECAUSE OF THE UNCERTAINTY OF THE FRONTAL POSITION. && .AVIATION /22Z TUESDAY THROUGH SUNDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. CONDS HAVE IMPROVED TO MVFR AND EVEN VFR IN SOME LOCATIONS AS LATEST SATELLITE IMAGERY SHOWED THE CLOUDS HAVE THINNED. EXPECT THESE TRENDS TO CONTINUE INTO THE EARLY EVENING BEFORE WE GET A REPEAT PERFORMANCE ONCE AGAIN. CLOUDS WILL LOWER AND THICKEN AND EVERYONE WILL BE MVFR/IFR AND EVEN LIFR DURG THE OVERNIGHT AND EARLY MORNING HOURS BEFORE SOME IMPROVEMENT AGAIN DURG WEDNESDAY. THE WIND SHOULD BE LIGHT AND GENLY FROM THE E AR SE. OUTLOOK... WEDNESDAY NIGHT THROUGH FRIDAY...IFR CONDS EACH NIGHT AND EARLY EACH DAY IN STRATUS AND/OR FOG BECOMING VFR IN THE AFTN. LOCAL IFR CONDS IN SHOWERS OR TSTMS. OUTLOOKING LESS COVERAGE AND DURATION OF IFR AND MVFR CONDITIONS ON FRIDAY THAN THURSDAY. SATURDAY AND SUNDAY...POSSIBLY SOME MVFR OR IFR STRATUS OR FOG EARLY OTHERWISE VFR. ISOLATED THUNDERSTORMS POSSIBLE MAINLY LATE EACH DAY WITH MVFR CONDITIONS. && .MARINE... THE PROLONGED ELY TO EVENTUALLY SELY WILL CONTINUE AND SEAS HAVE BEEN ABOVE SCA FOR MOST OF THE DAY. THIS WILL CONTINUE THROUGH THE NIGHT, BUT LTST GUIDANCE INDICATES THE SRN WATERS WILL RETREAT BELOW SCA VALUES ON WEDNESDAY. ACRS THE N, THINGS MAY LINGER LONGER. HOWEVER, FOR NOW, WILL LET THE PREV ISSUED SCA CONTINUE WITH NO CHANGES, BUT IT MAY NEED TO BE EXTENDED FOR A FEW HOURS, ESPECIALLY ACRS THE N. OUTLOOK... WE ARE NOT EXPECTING SMALL CRAFT ADVISORY CONDITIONS TO OCCUR THROUGHOUT THE OUTLOOK PERIOD AS THE ONSHORE FLOW FROM THE CANADIAN MARITIMES SHOULD NOT BE THAT STRONG AND EVEN IF WE GET A BACKDOOR FRONT, WINDS ARE NOT EXPECTED TO BE STRONG EITHER. THE GREATER MARINE CONCERNS WILL BE FOG AS DEW POINTS SHOULD RISE ABOVE THE WATER TEMPS. THIS MAY THE CASE EVERY MORNING INTO SUNDAY. ALSO THERE MAY BE STRONGER WINDS NEAR THUNDERSTORMS, ALTHOUGH THE GREATEST INSTABILITY IS EXPECTED TO BE WEST OF THE COASTAL WATERS. && .HYDROLOGY... THERE WILL PROBABLY BE NARROW SWATHS OF 72 HOUR TOTAL 1-3 INCH RFALL BETWEEN TONIGHT AND FRIDAY...MAINLY IN E PA AND POSSIBLY NNJ. PWATS THIS WEEK AROUND 1.4 INCHES INCREASE TO AT LEAST 1.75 INCHES THIS WEEKEND. && .RIP CURRENTS... THE SOUTHEAST SWELL SHOULD BE DROPPING TONIGHT INTO WEDNESDAY. WHILE THE PERIOD REMAINS FAIRLY LONG (NEAR 9 SECONDS)...THE SURF HEIGHT SHOULD COME DOWN AS WELL. BASED ON THE ABOVE...OUR LOCAL STUDY SHOWS THE NEW JERSEY COAST COMING IN AT MODERATE...AND THE DELAWARE COAST COMING IN WITH A LOW RISK OF RIP CURRENTS WEDNESDAY. THE ABOVE WILL BE REFLECTED IN THE EVENING SURF ZONE FORECAST FOR WEDNESDAY. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT WEDNESDAY FOR ANZ450>455. && $$ SYNOPSIS...GIGI NEAR TERM...HAYES/NIERENBERG SHORT TERM...NIERENBERG LONG TERM...GIGI/99 AVIATION...DRAG/GIGI/NIERENBERG MARINE...GIGI/NIERENBERG HYDROLOGY...DRAG RIP CURRENTS...HAYES
AREA FORECAST DISCUSSION
NWS MIAMI FL
951 PM EDT WED MAY 23 2012 .UPDATE...CHALLENGING FORECAST. LOCAL AREA HAS COME UNDER SUBSIDENCE TODAY AS EVIDENCED BY LITTLE CONVECTION. WE WERE IN THE SUBSIDENCE SIDE OF A DEPARTING JET. 500 MB TEMP HAS WARMED QUITE A BIT...NOW AT -6.9C ON THE EVENING MIAMI SOUNDING. SO NOT AS UNSTABLE. CONVECTION HAS REMAINED GENERALLY OFF THE SE FL COAST ALL DAY, THOUGH A FEW SHOWERS AND STORMS DID DEVELOP OVER THE INTERIOR AND GULF COAST. CONVECTION OVER THE ATLANTIC HAS NOW EVEN DIMINISHED. HOWEVER, THERE IS A SHORTWAVE OVER THE NORTH CENTRAL GULF HEADING ESE...AND MODELS INDICATE MORE FAVORABLE JET DYNAMICS LATE TONIGHT AND ESPECIALLY THURSDAY. HOWEVER, GFS/ECMWF CONSENSUS IS TO KEEP THE BEST CONVERGENCE/HEAVY RAIN JUST OFF TO OUR SOUTHEAST...AS A SURFACE/LOW LEVEL TROUGH AXIS LIES ALONG THE SE FL COAST. BUT SE FLOW IS STRENGTHENING SOME AND THIS COULD INCREASE COASTAL CONVERGENCE ALONG THE ATLANTIC COAST OVERNIGHT. THE LATEST HRRR SHOWS SHOWERS DEVELOPING AND MOVING NW ONSHORE THE ATLANTIC COAST LATER TONIGHT, ALTHOUGH IT`S OVERDOING ACTIVITY CURRENTLY. SO HERE`S THE BOTTOM LINE - THE MOST FAVORED AREA OVERNIGHT THROUGH THURSDAY FOR HEAVY RAIN LOOKS TO BE OFF OUR ATLANTIC COAST. HOWEVER, GIVEN HIGH MOISTURE AND POSSIBLE COASTAL CONVERGENCE, WILL MAINTAIN POPS AS IS. STILL LIKE THE FLOOD WATCH FOR MIAMI- DADE COUNTY THROUGH 8 PM THU...GIVEN THE EXTREME RAINFALL WHICH OCCURRED FROM THE SWEETWATER-DORAL AREAS ON TUESDAY WITH STANDING WATER REMAINING IN AREAS. IT WON`T TAKE MUCH RAIN TO CAUSE FLASH FLOODING ACROSS THESE HARD HIT LOCALES. /GREGORIA && .PREV DISCUSSION... /ISSUED 741 PM EDT WED MAY 23 2012/ AVIATION... SOUTH FLORIDA IS AT THE EDGE OF DEEP TROPICAL MOISTURE TO THE EAST AND ISOLATED CONVECTIVE ACTIVITY TO THE WEST. THE EAST COAST TERMINALS INCLUDE VCSH AFTER MIDNIGHT SINCE MOST GUIDANCE INSISTS IN INCREASING THE SHOWER ACTIVITY OVER NIGHT NEAR THE EAST COAST. HOWEVER, THIS IS A LOW CONFIDENCE FORECAST. FOR THURSDAY WE EXPECT SHOWERS AND THUNDERSTORMS TO BECOME MORE WIDESPREAD IN THE AFTERNOON AND EVENING. ALL TAF LOCATIONS INCLUDE THE CHANCE FOR VCTS FOR THURSDAY AFTERNOON. WINDS ARE EXPECTED TO BE FROM THE EAST SOUTHEAST BELOW 10 KNOTS. PREV DISCUSSION... /ISSUED 659 PM EDT WED MAY 23 2012/ UPDATE...CONVECTION TODAY HAS BEEN VERY MINIMAL DUE TO BROAD SCALE SUBSIDENCE. HOWEVER, AS A SHORTWAVE OVER THE NORTH CENTRAL GULF AS SEEN ON WATER VAPOR IMAGERY IS MOVING RATHER FAST TO THE EAST. THIS COULD INDUCE SOME OF THE HIGHER MOISTURE OVER THE ATLANTIC, AND ASSOCIATED RAINFALL, TO MOVE TOWARDS THE NW AND ONSHORE THE SE FLORIDA COAST OVERNIGHT. UNCERTAIN FORECAST TONIGHT AND THURSDAY AS WE ARE ON THE EDGE OF DEEP CARIBBEAN MOISTURE AND TROUGH AXIS. WILL MAINTAIN THE CHANCE POPS TONIGHT. FLOOD WATCH REMAINS IN EFFECT FOR MIAMI-DADE COUNTY THROUGH 8 PM THURSDAY FOR THE POTENTIAL FOR ADDITIONAL RAINS LEADING TO FLASH FLOODING. /GREGORIA PREV DISCUSSION... /ISSUED 348 PM EDT WED MAY 23 2012/ FLOOD WATCH EXTENDED UNTIL THURSDAY EVENING FOR MIAMI-DADE COUNTY... POSSIBLE STRONG TO EVEN SEVERE STORMS FOCUSED INTERIOR THIS AFTERNOON... DISCUSSION... EARLY THIS AFTERNOON...A MID TO UPPER LEVEL LOW WAS LOCATED OVER THE CAROLINAS WITH A TROUGH OF LOW PRESSURE EXTENDING SOUTHWEST THROUGH THE CWA AND INTO THE NORTHWEST CARIBBEAN SEA WHERE A WEAK SURFACE LOW PRESSURE SYSTEM WAS LOCATED. THE NATIONAL HURRICANE CENTER AT THIS TIME IS GIVING THE SURFACE LOW IN THE NORTHWEST CARIBBEAN SEAS A NEAR 0 PERCENT CHANCE OF DEVELOPMENT DURING THE NEXT 48 HOURS. THE MID TO UPPER LEVEL LOW WILL MOVE NORTHEAST KEEPING THE TROUGH OF LOW PRESSURE IN PLACE OVER THE CWA TONIGHT INTO THURSDAY...AS THE WEAK SURFACE LOW MOVES NORTHEAST AND THROUGH SOUTH FLORIDA OR JUST TO THE EAST OF SOUTH FLORIDA. THIS WILL KEEP THE STEERING FLOW IN PLACE ALONG WITH THE DEEP TROPICAL MOISTURE WORKING INTO THE SOUTHERN PORTION OF THE CWA FROM THE NORTHWEST CARIBBEAN SEA. THE LATEST PWAT`S FROM THE FORECAST MODELS ARE STILL SHOWING 2 TO 2.4 INCHES OVER THE SOUTHERN AREAS OF THE CWA LATE TONIGHT INTO THURSDAY WHICH IS CLOSE TO THE ALL TIME MAXIMUM PWAT FOR THIS TIME OF YEAR. THIS WILL ALLOW FOR SCATTERED SHOWERS AND THUNDERSTORMS TO CONTINUE OVER THE EAST COAST METRO AREAS TAPERING DOWN TO ISOLATED OVER THE INTERIOR AND WEST COAST METRO AREAS. ON THURSDAY...THE ACTIVITY COULD INCREASE TO SCATTERED COVERAGE OVER THE INTERIOR AREAS TO NUMEROUS COVERAGE OVER THE EAST COAST METRO AREAS. THEREFORE...A FLOOD WATCH FOR MIAMI-DADE COUNTY HAS BEEN EXTENDED THROUGH THURSDAY EVENING...DUE TO THE GROUND BEING VERY SATURATED FROM THE PREVIOUS RAINS OVER THE PAST COUPLE OF DAYS AND THE POTENTIAL OF MORE LOCALLY HEAVY RAINFALL TONIGHT INTO THURSDAY. THE WEAK LOW WILL THEN MOVE INTO WESTERN ATLANTIC WATERS PUSHING THE TROUGH OF LOW PRESSURE SOUTHWARD INTO THE FLORIDA KEYS. THIS WILL ALLOW FOR DRIER AIR TO WORK INTO THE CWA FROM THE NORTH FOR FRIDAY INTO THIS WEEKEND WHICH IN TURN WILL REDUCE THE COVERAGE OF THE SHOWERS AND THUNDERSTORMS OVER THE CWA. THE BEST CHANCE OF SHOWER AND THUNDERSTORM ACTIVITY WILL BE OVER THE INTERIOR AND WEST COAST METRO AREAS THIS WEEKEND...DUE TO THE NORTHEAST STEERING FLOW BEHIND THE TROUGH OF LOW PRESSURE. EXTENDED FORECAST... THE LATEST LONG RANGE MODELS ARE NOW SPLITTING ON THE RETURN MOISTURE TO THE AREA FOR EARLY TO MIDDLE OF NEXT WEEK. THE 23/00Z RUN OF THE ECMWF LONG RANGE MODEL TRIES TO BRING THE LOW BACK TO THE FLORIDA PENINSULA ALONG WITH THE DEEP MOISTURE...WHILE THE 23/12Z GFS MODEL PUSHES THE LOW EASTWARD TAKING THE DEEP TROPICAL MOISTURE WITH IT. SO AT THIS TIME WILL CONTINUE TO SHOW SCATTERED SHOWERS AND THUNDERSTORMS OVER THE CWA FOR EARLY TO MIDDLE OF NEXT WEEK...UNTIL THE MODELS BECOME MORE IN LINE WITH EACH OTHER FOR EARLY TO MIDDLE OF NEXT WEEK. MARINE... THE WINDS OVER THE CWA WATERS WILL REMAIN AT 15 KNOTS OR LESS TONIGHT INTO THIS WEEKEND WHILE SWINGING FROM A SOUTHERLY DIRECTION TONIGHT TO A NORTHERLY DIRECTION THIS WEEKEND. THE ONLY EXCEPTION TO THIS IS IN THE ATLANTIC WATERS WHERE THE WINDS WILL BE 15 TO 20 KNOTS TONIGHT. THE SEAS WILL ALSO REMAIN BELOW 6 FEET FOR BOTH THE ATLANTIC AND GULF WATERS OF SOUTH FLORIDA TONIGHT THROUGH THIS WEEKEND. SO WILL CONTINUE THE SCEC FOR THE ATLANTIC WATERS DUE TO THE WIND SPEEDS. FIRE WEATHER... THE RELATIVE HUMIDITIES WILL REMAIN ABOVE THE 35 PERCENT CRITICAL VALUE THROUGH THE WEEKEND. SO NO PROBLEMS WITH THE FIRE WEATHER PRODUCT. HYDROLOGY... FOR DETAILS ON THE RAINFALL AMOUNTS ACROSS SOUTH FLORIDA PLEASE SEE THE FLOOD WATCH AND THE HYDROLOGIC OUTLOOK STATEMENTS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 73 86 75 89 / 40 50 30 20 FORT LAUDERDALE 75 86 77 88 / 50 70 40 20 MIAMI 74 87 76 89 / 50 70 40 20 NAPLES 73 89 74 90 / 20 40 20 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...FLOOD WATCH THROUGH THURSDAY EVENING FOR COASTAL MIAMI DADE-FAR SOUTH MIAMI DADE-INLAND MIAMI DADE-METRO MIAMI DADE. AM...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1019 AM EDT Tue May 22 2012 .MESOSCALE UPDATE... The convective forecast for today was complicated by thunderstorms that that had moved southeast across Alabama overnight and then dissipated over the past 1-2 hours near the northwest corner of our forecast area. Basically no model handled this activity with any kind of skill; to illustrate that point, none of the models in a 25-member storm scale ensemble model from OU/CAPS had any storms in the area of TOI/DHN prior to 15z. The global models and other higher resolution models produced similar results. 11z HRRR model run finally initialized the small cluster of storms and related cold pool fairly well. It also correctly shows the new convection developing along a surface trough axis just offshore. Therefore, this was used as the basis for our forecast updates this morning. Initial development of storms today appears most likely 15-17z (in the next 3 hours) near the I-65 corridor, or just to the northwest of our forecast area. This is the scenario portrayed by the HRRR, low-level convergence is increasing in this area on the NW side of the residual cold pool / outflow, and an ACCAS field is in the process of developing. The HRRR then develops things east to ABY-MAI-DTS by 19z (3pm EDT). We will also need to keep an eye on the storm cluster offshore, as it would be on track to clip the Cape San Blas area around 16z if it holds together. Severe threat still looks to be mainly damaging winds. Deep inverted-V signature still showing up in the sub-cloud layer on most of the model forecast soundings. Maximum delta theta-e values are around 20-25C as well, on the lower cusp of favorable downburst parameter space. With deep mixing expected today, dewpoints are likely to fall back into the 50s. Modifying the 12z TAE sounding for surface conditions of about 88/56 yields SBCAPE around 1000 j/kg. The BMX sounding just upstream shows a mid-level temperature profile about 1-2C cooler as it was launched into the cold pocket of air aloft at the center of the digging shortwave. If mid-level temperatures in the NW part of our area cool to the BMX profile - it would add about 600 j/kg of CAPE to the sounding. With steepening mid-level lapse rates, some hail to around 1 inch in diameter couldn`t be ruled out either. Slight Risk by SPC still looks on target. We are expecting scattered thunderstorms. Most of the storms will produce some sort of gusty winds, and a few that can build taller cores or deeper/stronger cold pools could produce some wind gusts up to around 50kt. High temperatures were nudged up closer to observed values from yesterday as the low-level temperature profile has changed very little in the past 24 hours. Grid/product updates will be out shortly. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 90 64 91 65 93 / 50 30 20 10 10 Panama City 84 69 88 67 91 / 40 20 20 10 10 Dothan 90 65 93 66 94 / 60 30 20 10 10 Albany 90 64 91 65 93 / 50 30 20 10 10 Valdosta 92 63 91 64 92 / 50 40 20 10 10 Cross City 90 65 90 64 92 / 20 20 20 10 20 Apalachicola 85 67 86 68 84 / 30 10 20 10 10 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...None. GA...None. FL...Fire Weather Watch from Wednesday afternoon through Wednesday evening for Calhoun-Gadsden-Holmes-Inland Jefferson-Inland Walton-Jackson-Lafayette-Leon-Liberty-Madison-Washington. GM...None. && $$ 08-Lamers
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
432 AM EDT Tue May 22 2012 ...Strong to severe thunderstorms possible today... .SYNOPSIS... The 02 UTC regional surface analysis showed a typically weak late May pressure pattern, except behind a weak cold front that stretched from western TN to northern LA. There were also several outflow boundaries from either earlier or ongoing storm complexes. In fact, it`s difficult at times to distinguish the synoptic front from the outflow boundaries. Vapor imagery and upper air data showed a broad long wave trough over the Southeast U.S., with one vorticity max ejecting northeastward off the Mid Atlantic Coast as another was digging quickly southeastward over AL. Precip water values have recovered to near climatology over much of our forecast area. Strangely enough, isolated thunderstorms were developing sporadically across our forecast area at 4 am, which is unusual for this time of year. In fact, a loosely-organized complex of thunderstorms was just northwest of the Elba and Ozark area in Southeast AL. && .SHORT TERM... (Today through Thursday) A good portion of our forecast area is under a "Slight Risk" (15% chance of a severe storm within 25 miles of a point) of severe storms today, as the aforementioned upper trough temporarily closes off over north GA later today. The cold pool aloft will steepen our 700-500 mb lapse rates to the 6.5 to 7.5 deg C range, which is fairly substantial for our region. In addition, a 500 mb level jet max is forecast to develop across our area by this afternoon, increasing the 0-6 km vertical wind shear magnitude to about 30 KT. This could help produce at least some storm organization. Judging from the upstream reports over the past 12 to 24 hours with this system, we can expect reports of marginally severe hail (generally in the penny to quarter size range) and damaging wind gusts in the 45 to 60 MPH range. It is not clear how (or if) the loosely-organized thunderstorms just northwest of our area will impact our forecast for the evolution of today`s convection (either the amount or severity). None of the CAM models or HRRR initialized this feature, so we are are "winging it" a bit in the very near term. Our best guess is that is will weaken considerably as it moves into the northwest portions of our forecast area this morning. More storms will likely develop later, especially in the afternoon. The incoming day shift can re- evaluate this as needed. Much drier air will quickly advect from west to east this evening, bringing an end to the storms. GFS and NAM MOS have almost no PoP for our region Wednesday because of this very dry air aloft, but the Convection Allowing Models are managing to generate scattered convective cells. We introduced a 20 percent PoP for Wednesday afternoon in case a few updrafts survive the hostile upper level environment. The only PoP we show for Thursday is around Cross City and Perry, where there may be a bit more moisture as weak disturbance moves quickly northeastward across the FL Peninsula. We expect temperatures to be near average during the mornings, and a few degrees above average in the afternoons, with the warmest day being Thursday (with highs in the lower to mid 90s inland). The relative humidity will remain low enough during the afternoons to prevent the uncomfortable muggy conditions we would typically expect in a few weeks. .LONG TERM... (Thursday night through next Tuesday) Most of the extended period will be dominated by a strong upper ridge building over the eastern CONUS becoming centered across the Ohio Valley this weekend. The axis of the surface ridge will extend east to west from the western Atlantic through the Central Plains. As a result, the local region will be under deep layer easterly flow. Monday through Tuesday the upper ridge is forecast to break down as a shortwave tracks from the northern Plains to the Great Lakes region. Meanwhile, the surface ridge slides southward and weakens with low level flow veering to the southeast to south. The only relief from the anticipated above seasonal temperatures will be scattered convection over the weekend and early next week from the influx of moisture off the Atlantic. Max temperatures across inland areas will be in the lower to mid 90s. Min temps will generally be in the lower 70s. && .AVIATION... A brief period of MVFR vsby restriction at VLD is possible before sunrise. Otherwise, VFR conditions will prevail with just brief MVFR vsbys in afternoon and evening convection. Some of the storms may be strong to severe. Winds will be from the southwest around 10 knots outside of convection. && .MARINE... Winds and seas will remain at typically low May values through Friday, except for some higher winds and seas this afternoon and evening (and again on Wednesday) near the coast due to the sea breeze circulation enhancement. && .FIRE WEATHER... The minimum relative humidity should be above 35 percent today across north Florida today with scattered showers and thunderstorms by afternoon. A drier airmass filters back into the region on Wednesday and a Fire Weather Watch remain in place for interior portions of north Florida. These areas could see relative humidities less than 35 percent combined with dispersions greater than 75 and ERCs greater than 20. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 90 64 91 65 93 / 50 30 20 10 10 Panama City 84 69 88 67 91 / 40 20 20 10 10 Dothan 90 65 93 66 94 / 60 30 20 10 10 Albany 90 64 91 65 93 / 50 30 20 10 10 Valdosta 92 63 91 64 92 / 50 40 20 10 10 Cross City 90 65 90 64 92 / 20 20 20 10 20 Apalachicola 85 67 86 68 84 / 30 10 20 10 10 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...None. GA...None. FL...Fire Weather Watch from Wednesday afternoon through Wednesday evening for Calhoun-Gadsden-Holmes-Inland Jefferson-Inland Walton-Jackson-Lafayette-Leon-Liberty-Madison-Washington. GM...None. && $$ LONG TERM/AVIATION/FIRE WX...Barry Rest of Discussion...Fournier
AREA FORECAST DISCUSSION
NWS GOODLAND KS
540 PM MDT WED MAY 23 2012 .SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT) ISSUED AT 1245 PM MDT WED MAY 23 2012 EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW BROAD TROUGH ACROSS THE NORTHERN ROCKIES...WITH WEST/SOUTHWEST FLOW ACROSS THE INTER-MOUNTAIN WEST INTO THE CENTRAL HIGH PLAINS. AT THE SURFACE A COLD FRONT HAS STALLED OVER WESTERN KANSAS...CURRENTLY ACROSS THE EASTERN PART OF THE CWA. A SHORTWAVE TROUGH CURRENTLY OVER THE GREAT BASIN WILL MOVE EAST-NORTHEAST ACROSS NORTH CENTRAL COLORADO AND SOUTHWEST NEBRASKA TONIGHT. SHOWERS/THUNDERSTORMS HAVE ALREADY DEVELOPED AHEAD OF THIS FEATURE ALONG THE FRONT RANGE INTO SOUTHEASTERN WYOMING. THIS ACTIVITY WILL SPREAD SOUTH AND EAST OVER OUR CWA LATER THIS AFTERNOON...WITH COVERAGE INCREASING ACROSS THE NORTHERN PART OF OUR FORECAST AREA THROUGH 06Z. CONVERGENCE ZONE ALONG AND NORTH OF STALLED FRONT COULD ACT AS A FOCUS FOR EARLIER THUNDERSTORM INITIATION LATER THIS AFTERNOON AND EVENING...HOWEVER THIS IS REMOVED FROM LARGE SCALE ASCENT ASSOCIATED WITH SHORTWAVE SO COVERAGE SHOULD BE LIMITED ACROSS THE SOUTH. VERY STRONG SHEAR IS PRESENT ACROSS THE CWA...WITH INSTABILITY DECREASING THE FURTHER NORTH IN THE CWA WHERE TD VALUES IN THE 30-40F RANGE HAVE ADVECTED IN BEHIND THE FRONT. SEVERE CONVECTION SHOULD BE LIMITED TO THE I-70 CORRIDOR THROUGH EARLY EVENING WHERE THE BEST OVERLAP BETWEEN SHEAR/INSTABILITY IS EXPECTED. LATER TONIGHT ELEVATED INSTABILITY COULD COMBINE WITH STRONG UPPER LEVEL DYNAMICS ASSOCIATED WITH THE SHORTWAVE ACROSS SOUTHWEST NEBRASKA TO BRING ADDITIONAL SEVERE CHANCES. SUBSIDENCE QUICKLY BUILDS IN BEHIND DEPARTING SHORTWAVE TROUGH AFTER 06Z...WITH COVERAGE DECREASING FROM THE SOUTHWEST TO THE NORTHEAST THROUGH SUNRISE THURSDAY. .LONG TERM...(THURSDAY THROUGH WEDNESDAY) ISSUED AT 224 PM MDT WED MAY 23 2012 THURSDAY-THURSDAY NIGHT...PV ANOMALY WILL LIFT TO THE NORTH AND EAST OF THE AREA FAIRLY QUICKLY DURING THE MORNING HOURS...WITH MID LEVEL FRONTOGENESIS QUICKLY DIMINISHING AND DEEP LAYER DIV Q FIELDS INDICATE FAIRLY STRONG LARGE SCALE FORCING FOR SUBSIDENCE OVER THE AREA. STILL HAVE A FEW TIMING CONCERNS THOUGH...AND THINK HOLDING ONTO SOME SMALL POPS WARRANTED FOR AT LEAST THE FIRST FEW HOURS OF THE PERIOD. SOUNDINGS SUGGEST THAT WEAK INSTABILITY WILL LINGER ACROSS MUCH OF THE AREA THROUGH THE DAY...AS DIFFERENTIAL TEMP ADVECTION SHOULD LEAD TO THE DEVELOPMENT OF SHALLOW SFC BASED INSTABILITY WITH EQUILIBRIUM LEVELS LESS THAN H5 AT MANY LOCATIONS. ALTHOUGH SUBSIDENCE DIMINISHES IN THE AFTERNOON ACROSS SOUTHERN HALF OF CWA...THINKING ANY AFTERNOON SHOWERS WILL BE STRONGLY DIURNALLY DRIVEN AND THINK OVERALL COVERAGE WILL BE FAIRLY LOW THROUGH THE EARLY EVENING. LARGE SCALE ASCENT WILL ONCE AGAIN WITH STRONG LOW LEVEL WAA DEVELOPING IN RESPONSE TO H3 JET STREAK LIFTING NORTH INTO SOUTHERN SOUTH DAKOTA. SEEMS LIKE RECENT SUITE OF MODELS NOT ALL THAT OPTIMISTIC ABOUT BREAKING OUT PRECIPITATION OVERNIGHT...BUT GIVEN STRONG AND PERSISTENT WAA/ISENTROPIC FORCING STRONG MOISTURE TRANSPORT ABOVE THE SFC...AND SMALL CONDENSATION PRESSURE DEFICITS IN AREA OF NEGATIVE THETA E LAPSE RATES...THINK THE THREAT FOR SHOWERS AND STORMS WILL BE THERE DESPITE CURRENT MODEL QPF OUTPUT. FRIDAY-SATURDAY...WARM FRONT WILL SLOWLY LIFT TO THE NORTH THROUGH THE PERIOD AND WILL NOT ONLY PLAY A BIG ROLE ON POTENTIAL FOR THUNDERSTORMS...IT WILL ALSO HAVE A LARGE ROLE IN TEMPERATURE FORECAST AS POSSIBILITY EXISTS FOR A PRETTY SHARP GRADIENT WITH TEMPS ON FRIDAY. SREF PLUME DATA INDICATING NEARLY A 20 DEGREE SPREAD IN TEMPS FOR MOST LOCATIONS...WITH ABOUT EQUAL CLUSTERING ON EITHER SIDE...MAINLY ON FRIDAY. PLAN ON KEEPING NEAR MEAN VALUES FOR FRIDAY...ALTHOUGH THERE IS MUCH MORE AGREEMENT ON VERY WARM TEMPS ON SATURDAY AND HAVE WARMED TEMPS ACCORDINGLY. GIVEN EXPECTED PRESSURE FALL PATTERN AROUND AREA AND LARGE SCALE FORCING FOR ASCENT BECOMING MAXIMIZED WELL TO THE WEST OF THE AREA...DO NOT ANTICIPATE MUCH OF A NORTHERN MOVEMENT OF THE FRONT...WITH BULK OF CWA REMAINING CLOUDY AND COOL THROUGH THE DAY. THINK THUNDERSTORMS WILL LIKELY BE ONGOING THROUGH THE MORNING HOURS AS PREVIOUSLY MENTIONED WAA PATTERN REMAINS IN PLACE THROUGH THE MORNING HOURS...BEFORE LARGE SUBSIDENCE INVERSION STRENGTHENS DURING THE AFTERNOON SHARPLY INCREASING CINH PROFILES AND ADVECTING MUCH DRIER AIR INTO THE AREA. MODELS CONTINUE TO PRODUCE LIGHT PRECIPITATION AFTER THIS POINT...BUT SOUNDINGS LOOK LIKE ANY PRECIPITATION PROCESSES IN THE LATE AFTERNOON OR EVENING LOOK TO BE VERY SHALLOW/DRIZZLE TYPE PROCESSES AND DO NOT PLAN ON GOING ALONG WITH HIGHER GUIDANCE POPS AT THIS TIME. APPEARS TO BE LOTS OF INSTABILITY DURING THE LATE AFTERNOON AND EVENING ALONG/NORTH OF FRONT...BUT CINH LOOKS VERY STRONG AND GIVEN RIDGING ALOFT DO NOT THINK THIS WILL BE OVERCOME. ON SATURDAY...EXPECT WINDY TO VERY WINDY CONDITIONS TO DEVELOP ACROSS MUCH OF THE AREA DURING THE AFTERNOON WITH STRONGEST WINDS BEHIND DRYLINE IN EASTERN COLORADO...WHERE DEEP MIXED LAYER SHOULD TAP INTO STRONG FLOW ALOFT. WITH TEMPS IN THE 90S...WIND GUSTS APPROACHING 50 KTS AND MIXED TDS SUGGESTING A RAPID DROP OFF IN DEWPOINTS...POTENTIAL EXISTS FOR EXTREMELY CRITICAL FIRE WX CONDITIONS TO DEVELOP. IT IS A BIT TOO FAR IN THE FUTURE TO ISSUE ANY HIGHLIGHTS AT THIS POINT...BUT POTENTIAL FOR FIRE WEATHER AND SIGNIFICANT WINDS IS INCREASING. OTHERWISE...WARM FRONT WILL LIFT TO THE NORTH OUT OF THE AREA DURING THE MORNING HOURS WITH ANY POTENTIAL FOR AFTERNOON THUNDERSTORMS ALONG DRYLINE DURING THE LATE AFTERNOON. WITH DEEP MIXING AND BULK OF PRESSURE FALLS TO THE NORTH OF THE AREA...WOULD EXPECT DRYLINE TO MIX EASTWARD WITH BULK OF CWA IN DRY SECTOR. ENOUGH SPREAD EXISTS TO WARRANT A MORE BROAD BRUSHED APPROACH TO CHANCES ATTM THOUGH AND WITH STRONG FLOW ALOFT THERE WILL BE POTENTIAL FOR AT LEAST A FEW STRONG/SEVERE HIGH BASED STORMS IN THE AFTERNOON. IN THE EXTENDED (SAT NIGHT-WEDNESDAY)...ACTIVE WEATHER PATTERN EXPECTED THROUGH THE PERIOD AS MEDIUM RANGE MODELS SHOWING REASONABLE AGREEMENT IN DEVELOPMENT OF STRONG TROUGH/AMPLIFIED PATTERN ACROSS THE PLAINS THROUGH THE WEEKEND...FOLLOWED BY MORE ZONAL FLOW ALOFT DURING THE BEGINNING OF THE WEEK. WHILE 06Z GEFS DATA SHOWS A RELATIVELY CONSISTENT PATTERN WITH LARGE TROUGH IMPACTING THE AREA DURING THE WEEKEND...MODEL SPREAD/UNCERTAINTY INCREASES DURING THE LATER HALF AS THERE APPEARS TO BE A DECENT AMOUNT OF DISCREPANCY WITH SMALL SCALE FEATURES. BEST CHANCE FOR PRECIPITATION WILL LIKELY BE ON SUNDAY AFTERNOON AS COLD FRONT SLOWLY MOVES ACROSS THE AREA PROVIDING AMPLE FORCING TO FOCUS THUNDERSTORM DEVELOPMENT. WITH LIGHT EASTERLY/UPSLOPE FLOW AND SEVERAL FAST MOVING SHORT WAVE TROUGHS MOVING THROUGH ZONAL FLOW...PRECIP CHANCES WILL CONTINUE THROUGH THE MIDDLE OF THE WEEK. ASIDE FROM TIMING WITH FROPA ON SUNDAY BRINGING THE POTENTIAL FOR ONE MORE VERY WARM DAY...LOOKS LIKE COOLER CONDITIONS WILL PREVAIL THROUGH THE START OF THE WEEK AS LIGHT EASTERLY FLOW WILL PREVAIL BEHIND COLD FRONT. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 534 PM MDT WED MAY 23 2012 CURRENT RADAR DETECTING SHOWERS AND A FEW THUNDERSTORMS MOVING EAST FROM EASTERN COLORADO. THESE STORMS SHOULD IMPACT BOTH KGLD AND KMCK LATER THIS EVENING. SOME MVFR CONDITIONS ARE POSSIBLE NEAR THUNDERSTORMS. OTHERWISE MID LEVEL CLOUDS SHOULD CLEAR OUT BY MID MORNING AS SHORTWAVE EXITS THE REGION. WINDS WILL BECOME GUSTY BY LATE MORNING AND CONTINUE IN THE AFTERNOON. && .FIRE WEATHER... ISSUED AT 224 PM MDT WED MAY 23 2012 VERY WINDY CONDITIONS...WITH GUSTS IN EXCESS OF 50 MPH POSSIBLE...ARE EXPECTED ACROSS A LARGE PORTION OF THE AREA ON SATURDAY. AFTERNOON HUMIDITIES WILL FALL TO AROUND 10 PERCENT ACROSS PORTIONS OF EASTERN COLORADO AND ADJACENT AREAS DURING THE AFTERNOON AS THE WINDS INCREASE. THE COMBINATION OF VERY DRY AND VERY WINDY CONDITIONS WILL BRING THE POTENTIAL FOR EXTREMELY CRITICAL CONDITIONS ON SATURDAY. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...JRM AVIATION...FS FIRE WEATHER...JRM
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
620 PM CDT WED MAY 23 2012 ...UPDATED AVIATION SECTION... .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 142 PM CDT WED MAY 23 2012 NAM, RAP, AND HRRR WERE IN DECENT AGREEMENT WITH COLD FRONT EXTENDING FROM NORTH CENTRAL KANSAS INTO EXTREME SOUTHWEST KANSAS LATE THIS AFTERNOON AND EARLY THIS EVENING. THIS FRONT WILL BE LOCATED UNDER +14C TO +16C 700MB TEMPERATURES. IN ADDITION THE BETTER LOW LEVEL MOISTURE IS STILL FORECAST TO BE LOCATED ACROSS CENTRAL KANSAS AND FROM NORTHWEST KANSAS INTO SOUTH CENTRAL NEBRASKA. BASED ON MODEL SOUNDINGS THE WARM MID LEVEL TEMPERATURES LATE TODAY/EARLY TONIGHT APPEARS TO SERVE AS A CAP ACROSS MOST OF SOUTHWEST KANSAS. THE POSSIBLE EXCEPTION WILL BE NEAR AND NORTH OF INTERSTATE 70 IN NORTH CENTRAL KANSAS WERE BETTER LOW LEVEL FRONTOGENESIS AND MOISTURE WILL BE PRESENT. IN ADDITION THIS WILL BE NEAR THE NORTHERN EDGE OF THE WARM MID LEVEL TEMPERATURES. THE NAM EVEN SUGGESTS SOME COOLING OCCURRING IN THE MID LEVEL AFTER 21Z ALONG AND NORTH OF INTERSTATE 70. GIVEN THE COOLER MID LEVEL TEMPERATURES, BETTER LOW LEVEL MOISTURE/FRONTOGENESIS NEAR THE SURFACE BOUNDARY, AND CAPES EARLY TONIGHT GREATER THAN 1000 J/KG WILL GO AHEAD AND KEEP A MENTION OF THUNDERSTORMS NEAR THE SURFACE BOUNDARY. ALSO BASED ON 0-6KM SHEAR FORECAST TO BE AROUND 50 KNOTS ALONG WITH 1000-2000 J/KG THERE WILL BE A CHANCE FOR ANY STORM THAT DOES DEVELOP TO BECOME SEVERE. MAIN HAZARD STILL APPEARS TO BE HAIL UP TO HALF DOLLAR SIZE AND WINDS UP TO 60 MPH. FURTHER WEST...THE CONVECTION DEVELOPING ACROSS NORTHEAST COLORADO IS EXPECTED TO SPREAD EAST EARLY TONIGHT BUT STAY NORTH OF THE INTERSTATE 70 DURING THE OVERNIGHT HOURS. THE COLD POOL THAT IS FORECAST TO DEVELOP WITH THESE STORMS OVERNIGHT SHOULD PUSH THE COLD FRONT SOUTH ACROSS ALL OF SOUTHWEST KANSAS AFTER MIDNIGHT. BY EARLY THURSDAY MORNING THIS COLD FRONT IS EXPECTED TO BE LOCATED ACROSS CENTRAL KANSAS AND NORTHERN OKLAHOMA. BOUNDARY LAYER WINDS BEHIND THIS FRONT ARE FORECAST TO RANGE FROM 30 TO 35 KNOTS AND GIVEN THE TIGHT PRESSURE GRADIENT BEHIND THIS FRONT THE SURFACE WINDS MAY APPROACH ADVISORY CRITERIA FOR A FEW HOURS FOLLOWING THE FRONTAL PASSAGE LATE TONIGHT. AT THIS TIME HAVE DECIDED TO KEEP SUSTAINED WINDS JUST BELOW ADVISORY CRITERIA FOR A FEW HOURS BEHIND THIS FRONT. IN ADDITION TO THE WINDS SOME LOW LEVEL MOISTURE WILL RETURN TO NORTH CENTRAL AND SOUTHWEST KANSAS. THE WRF AND NMM EVEN SUGGESTS SOME LIGHT PRECIPITATION WILL BE POSSIBLE AS THE LOWER LEVELS SATURATES. AT THIS TIME GIVEN THE ISENTROPIC DOWNGLIDE PRESENT AND DEPTH OF THE MOIST LAYER LESS THAN 3000 FEET AM TRENDING AWAY FROM INSERTING PRECIPITATION CHANCES AFTER MIDNIGHT. ON THURSDAY THE GUSTY NORTHWEST WINDS WILL GRADUALLY SUBSIDE BY MID MORNING AS THE COLD FRONT CONTINUES TO MOVE SOUTHEAST ACROSS EASTERN KANSAS AND OKLAHOMA. IN SOUTHEAST COLORADO THIS FRONT IS EXPECTED TO BECOME NEARLY STATIONARY DURING THE DAY WITH SOME ISENTROPIC LIFT/WARM AIR ADVECTION DEVELOPING NORTH OF THIS BOUNDARY BY LATE DAY. THIS MAY BRING AN INCREASE IN MID LEVEL CLOUD COVER LATE DAY TO PORTIONS OF SOUTHWEST KANSAS BASED ON I310 AND I315 ISENTROPIC SURFACES AND 12Z BUFR SOUNDINGS. GIVEN SOME INCREASING CLOUDS LATE DAY AND 850MB TEMPERATURES AT 00Z FRIDAY WILL TREND TOWARDS THE COOLER GUIDANCE IN FAR SOUTHWEST KANSAS NEAR THE OKLAHOMA BORDER WHILE FURTHER NORTH HAVE KEPT HIGHS CLOSER TO THE WARMER 850MB MIX DOWN TEMPERATURES. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 234 PM CDT WED MAY 23 2012 THURSDAY NIGHT: NOT THAT IMPRESSED FOR PROSPECTS OF CONVECTION THURSDAY EVENING. SOME ISENTROPIC LIFT IS EXPECTED ALONG THE 700 HPA BAROCLINIC BOUNDARY ACROSS CENTRAL KANSAS. FORECAST SOUNDINGS FROM THE ECMWF/GFS SHOW THAT THERE MAY BE SOME MID LEVEL CLOUDS, HOWEVER, THE OVERALL PROFILE IS FAIRLY DRY AND CAPPED. WENT AHEAD AND THREW IN SOME SILENT POPS ACROSS MY NORTHERN COUNTIES BUT DISCOUNTED THE WETTER GFS SOLUTION WHICH CONTINUES TO SUFFER FROM OVERALL POOR SYNOPTIC PERFORMANCE. THE 4 KM NAM & ARW/NMM CORES AREN`T TOO CONVINCING EITHER. FRIDAY: THE WARM SECTOR WILL CONTINUE TO SPREAD NORTHWARD DOWNSTREAM OF A SLOWLY PROPAGATING 500 HPA TROUGH FURTHER WEST. TEMPERATURES WARM TO 33 DEG C @ 850 HPA AND 15 DEG C & 700 HPA WITH A WELL MIXED ATMOSPHERE. HAVE WARMED TEMPERATURES TO THE MID TO UPPER 90S DEG F ACROSS THE CENTRAL AND SOUTHERN ZONES AS A RESULT. THE ECMWF IS VERY WARM WITH 102 DEG F FOR DODGE CITY FRIDAY. WILL CONTINUE TO THE TREND UPWARD BUT NOT YET BITE ON THE EXTREME. THERE COULD BE SOME CONVECTION EAST OF THE DRYLINE FRIDAY EVENING BUT WITH SUCH WARM TEMPERATURES AT 700 HPA, WILL NOT GO HIGHER THAN SLIGHT GIVEN THE VERY STOUT EML. ECMWF SHOWS ABOUT 2500 J/KG OF SBCAPE AND 30 TO 40 KT OF SHEAR SO WILL HAVE TO WATCH OUT FOR SEVERE IN LATER FORECASTS. SATURDAY: AMPLIFICATION OF THE WESTERN TROUGH IS EXPECTED SATURDAY. THE 12Z ECMWF IS LESS AGGRESSIVE WITH CONVECTION FOR SATURDAY EVENING ACROSS THE WEST THAN COMPARED TO THE 00Z RUN. THIS IS PROBABLY DUE TO THE CONTINUED STRONG EML FORECAST BY THE MODEL. WILL NOT GO HIGHER THAN SLIGHT POPS IN THE MEANTIME. NOT MUCH UPPER LEVEL SUPPORT AS THE MAIN 250 HPA JET AXIS IS STILL PRETTY FAR WEST. WILL CONTINUE HOT TEMPERATURES IN THE GRIDS WITH MID TO UPPER 90S DEG F EXPECTED ACROSS MUCH OF THE REGION. SUNDAY AND BEYOND: CONVECTIVE PROSPECTS ARE BETTER SUNDAY AS THE RIGHT ENTRANCE REGION OF THE AFOREMENTIONED 250 HPA TRAVERSES ACROSS NW KANSAS. CAA ASSOCIATED WITH THE TROUGH AND LOW TO MID LEVEL COLD POOLS WILL ALLOW FOR A WEAKENING OF THE EML. THE BEST CHANCE FOR CONVECTION APPEARS TO BE ACROSS CENTRAL AND SOUTH CENTRAL KANSAS ALONG AND EASTWARD MIXING DRYLINE. THE THERMODYNAMIC AND KINEMATIC PROFILES ARE SUPPORTIVE OF SEVERE WEATHER. UL FLOW FLATTENS MONDAY AND TUESDAY AS THE ASSOCIATED TROUGH MOVES ACROSS THE CANADIAN PRAIRIES. THIS WILL ALLOW FOR MORE SEASONAL YET ABOVE NORMAL TEMPERATURES ACROSS SW KANSAS. WILL HAVE TO WATCH THE MIDWEEK PERIOD NEXT WEEK AS IT TRANSITIONS INTO MORE OF A MCS PATTERN. DEWPOINTS/MOISTURE COULD BE AN ISSUE THOUGH. HAVE GONE WITH A CLEANED UP VERSION OF ALLBLEND POPS. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 620 PM CDT WED MAY 23 2012 A FRONTAL BOUNDARY WILL CONTINUE TO MOVE SLOWLY THROUGH THE TAF SITES OVERNIGHT TONIGHT SHIFTING WINDS FROM A SOUTHERLY DIRECTION TO THE NORTH NORTHEAST. GUSTY CONDITIONS WILL CONTINUE AHEAD AND BEHIND THIS SYSTEM WITH VARIABLE WINDS ALONG THE COLD FRONT. VFR CONDITIONS WILL PREVAIL WITH HIGH CLOUDS AOA100-200. && .PRELIMINARY POINT TEMPS/POPS... DDC 55 83 62 97 / 0 0 10 10 GCK 53 82 60 96 / 10 0 10 10 EHA 56 85 59 96 / 0 0 10 10 LBL 54 85 62 100 / 0 0 10 10 HYS 55 80 59 86 / 30 10 10 20 P28 65 85 67 97 / 0 0 10 20 && .DDC WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR KSZ066-080-081-089- 090. && $$ SHORT TERM...BURGERT LONG TERM...SUGDEN AVIATION...HOVORKA 42
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
234 PM CDT TUE MAY 22 2012 ...UPDATE TO LONG TERM DISCUSSION... .SYNOPSIS... ISSUED AT 1218 PM CDT TUE MAY 22 2012 A 500MB UPPER TROUGH WAS LOCATED NEAR THE SOUTHWEST COAST OF BRITISH COLUMBIA AND NORTHWEST WASHINGTON AT 12Z TUESDAY. A 120-140KT UPPER LEVEL JET WAS PLACE NEAR AND JUST SOUTHWEST OF THE BASE OF THIS UPPER TROUGH. 90-110 METER HEIGHT FALLS WERE OBSERVED ACROSS EASTERN IDAHO AND WESTERN MONTANA. A WESTERLY FLOW EXTENDED ACROSS THE ROCKIES INTO THE WESTERN HIGH PLAINS WITH +12 TO +13C 700MB TEMPERATURES STRETCHING FROM EASTERN WYOMING/WESTERN NEBRASKA INTO NORTHEAST NEW MEXICO. UNDER THESE WARM 700MB TEMPERATURES AT THE SURFACE THERE WAS A TROUGH OF LOW PRESSURE ACROSS WESTERN NEBRASKA AND EXTREME EASTERN COLORADO/FAR WESTERN KANSAS. && .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 128 PM CDT TUE MAY 22 2012 RAP, NAM AND HRRR PLACE THE SURFACE TROUGH OF LOW PRESSURE NEAR THE COLORADO BORDER THIS EVENING. MODEL SOUNDINGS AT 00Z WEDNESDAYS IN THIS AREA INDICATING LITTLE TO NO CIN WITH A TEMPERATURES DRY ADIABATIC UP TO AROUND THE 600MB LEVEL WHERE SOME MOISTURE IS PRESENT. ALSO OBSERVING SOME INSTABILITY PRESENT AS WELL SO AM UNABLE TO COMPLETELY RULE OUT A EARLY EVENING THUNDERSTORM DEVELOPING NEAR THE COLORADO BORDER EARLY THIS EVENING. RAP AND HRRR DO HINT AT A FEW STORMS DEVELOPING AFTER 22Z NEAR THE ELKHART WHERE THE BETTER INSTABILITY ARE FORECAST TO BE LOCATED. WITH THIS IN MIND THE PREVIOUS PRECIPITATION FORECAST FOR EXTREME SOUTHWEST KANSAS STILL APPEARS TO BE ON TRACK. ALSO BASED ON THE INVERTED V TYPE OF SOUNDINGS IT DOES APPEAR THAT STRONG WINDS UP TO 60 OR 70 MPH WILL BE THE MAIN HAZARD. ANY STORM THAT DOES DEVELOP EARLY THIS EVENING IS EXPECTED TO END BEFORE MIDNIGHT BUT MAY MOVE AS FAR EAST AS LIBERAL IF THESE A COLD POOL CAN BE DEVELOPED FROM STORMS. AFTER MIDNIGHT SOUTH WINDS OF 15 TO 25 MPH ARE EXPECTED TO CONTINUE AND BASED ON TEMPERATURES EARLIER THIS MORNING WILL FAVOR OVERNIGHT LOWS AROUND 5F WARMER THAN GUIDANCE. ON WEDNESDAY A SURFACE TROUGH/DRYLINE WILL SLIDE EAST INTO WESTERN KANSAS DURING THE DAY AS A COLD FRONT DROPS SOUTH INTO NORTHWEST KANSAS BY LATE MORNING. THE COLD FRONT IS EXPECTED TO BE LOCATED FROM WEST CENTRAL KANSAS AND NORTH CENTRAL KANSAS BY THE MID AFTERNOON AS WARM MID LEVEL TEMPERATURES SPREADS EAST ACROSS SOUTHWEST KANSAS. MODEL SOUNDINGS INDICATING ANOTHER DAY OF GOOD MIXING AND BASED ON MODEL SOUNDINGS AT 00Z THURSDAY IT CURRENTLY APPEARS HIGHS AROUND 100 DEGREES WILL STILL BE POSSIBLE WEST OF THE DRYLINE. EAST OF THE DRYLINE AND NEAR THE COLD FRONT THE HIGHS WILL BE SLIGHTLY COOLER AND RANGE FROM THE LOW TO MID 90S. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 234 PM CDT TUE MAY 22 2012 WEDNESDAY NIGHT: A FRONTAL BOUNDARY COULD BE THE IMPETUS FOR CONVECTION WEDNESDAY NIGHT MAINLY ACROSS THE INTERSTATE 70 CORRIDOR. MARGINAL SURFACE DEWPOINTS IN THE 50S DEG F AND VERY WARM MAXIMUM TEMPERATURES IN THE 90S DEG F ACROSS CENTRAL KANSAS WILL CONTRIBUTE TO 1500 TO 2500 J/KG OF SBCAPE. AN 850 HPA THETA-E AXIS WILL ALSO EXIST ACROSS WEST CENTRAL KANSAS WITH BROAD SOUTHWESTERLY FLOW ALOFT WHICH POINT TO FAVORABLE CONDITIONS FOR CONVECTION. SEVERE WEATHER CANNOT BE RULED OUT WITH 40 TO 50 KT OF BULK 0 TO 6 KM SHEAR. THURSDAY: A BROAD 500 HPA TROUGH IS EXPECTED FROM THE PACIFIC NORTHWEST TOWARDS THE NORTHERN PLAINS. ANOTHER VORTMAX MOVING DOWNSTREAM WILL USHER IN A COLD FRONT EXTENDING FROM THE UPPER MIDWEST TO SOMEWHERE IN KANSAS. I SAY SOMEWHERE BECAUSE THERE IS PRETTY LARGE SPATIAL DIFFERENCES BETWEEN THE ECMWF/GFS. THIS IS PARTICULARLY TRUE WHEN THE FRONT RETURNS AS A WARM FRONT LATE THURSDAY. DECIDED TO TAKE THE MORE AGGRESSIVE ECMWF APPROACH WITH THE NORTHWARD PROGRESSION OF THIS WARM FRONT. SOUTH OF THIS FRONT, LOW LEVEL TEMPS ARE EXPECTED TO BE VERY WARM (30 DEG C @ 850 HPA/15 DEG C @ 700 HPA), SO HAVE KEPT LOWER 90S DEG F TOWARDS THE OKLAHOMA BORDER AND "COOLER" 80S DEG F ACROSS WEST CENTRAL KANSAS. NOT EXPECTING ANY CONVECTION AS A RESULT OF THE EML ADVECTION ACROSS SW KANSAS. FRIDAY: A WAA PATTERN WILL STRENGTHEN FRIDAY WITH THE EML SPREADING FURTHER NORTH AND 850 HPA TEMPERATURES WARMING TO 33 DEC C. 700 HPA TEMPERATURES WILL ALSO BE VERY WARM AND NEAR 16 DEG C. THERE MIGHT BE AN ISOLATED STORM NEAR HAYS FRIDAY EVENING, BUT AM DUBIOUS OF THIS GFS SOLUTION SO HAVE KEPT POPS IN SLIGHT CATEGORY GIVEN THE STOUT EML. THERE IS ALSO NOT MUCH IN THE WAY OF UPPER LEVEL SUPPORT AS 500 HPA HEIGHT INCREASES ARE EXPECTED ACROSS THE REGION ASSOCIATED WITH MID LEVEL SHORTWAVE RIDGING. TEMPERATURES WILL BE HOT AND IN THE 90S DEG F. IF THE ECMWF SOLUTION IS CORRECT, THEN A 100 DEGREE DAY IS POSSIBLE FOR SOME LOCATIONS AND TEMPERATURES NEED TO BE INCREASED IN THE FUTURE. SATURDAY AND BEYOND: FOLLOWED THE ECMWF SOLUTION FOR THIS PERIOD. A VERY BROAD MID LEVEL TROUGH IS EXPECTED ACROSS THE GREAT BASIN. ANY JET LEVEL DYNAMICS LOOK TO REMAIN WELL NORTH OF KANSAS WITH GREATEST CHANCE OF HIGHER IMPACT SEVERE WEATHER NORTH OF THE REGION. THERE COULD BE SOME STORMS ACROSS SOUTHWEST KANSAS THROUGH THE WEEKEND, HOWEVER, THE ATMOSPHERE LOOKS PRETTY CAPPED. MADE A FEW TWEAKS TO THE ALLBLEND POPS (CLEANED UP) AND WARMED TEMPERATURES UP WITH A BIAS TOWARDS THE ECMWF. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1218 PM CDT TUE MAY 22 2012 A TIGHT PRESSURE GRADIENT COMBINED WITH 30-40KT WINDS IN THE 900-850MB LEVEL WILL RESULT SUSTAINED WINDS OF AROUND 25 KNOTS THROUGH THE REMAINDER OF THE DAY...ESPECIALLY AT DDC AND HYS. THESE GUSTY WINDS WILL SUBSIDE SOME AFTER SUNSET BUT BASED ON THE SURFACE PRESSURE GRADIENT SUSTAINED WIND SPEEDS OF 15 TO 20 KNOTS STILL APPEARS LIKELY. A LOW LEVEL JET IS FORECAST TO DEVELOP TOWARDS 06Z WITH WIND SPEEDS OF 50 TO 55 KNOTS BETWEEN 1500 AND 2000 FEET SO INSERTED A WIND SHEAR GROUP INTO THE TAFS OVERNIGHT. BUFR SOUNDINGS CONTINUE TO INDICATE VFR CONDITIONS OVER THE NEXT 24 HOURS. && .PRELIMINARY POINT TEMPS/POPS... DDC 65 97 63 86 / 0 10 10 10 GCK 64 98 58 85 / 0 10 10 10 EHA 63 99 58 91 / 20 0 10 10 LBL 65 102 61 89 / 20 0 10 10 HYS 67 93 61 83 / 0 20 20 10 P28 66 93 70 89 / 0 0 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BURGERT SHORT TERM...BURGERT LONG TERM...SUGDEN AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
131 PM CDT TUE MAY 22 2012 ...UPDATED SHORT TERM DISCUSSION... .SYNOPSIS... ISSUED AT 1218 PM CDT TUE MAY 22 2012 A 500MB UPPER TROUGH WAS LOCATED NEAR THE SOUTHWEST COAST OF BRITISH COLUMBIA AND NORTHWEST WASHINGTON AT 12Z TUESDAY. A 120-140KT UPPER LEVEL JET WAS PLACE NEAR AND JUST SOUTHWEST OF THE BASE OF THIS UPPER TROUGH. 90-110 METER HEIGHT FALLS WERE OBSERVED ACROSS EASTERN IDAHO AND WESTERN MONTANA. A WESTERLY FLOW EXTENDED ACROSS THE ROCKIES INTO THE WESTERN HIGH PLAINS WITH +12 TO +13C 700MB TEMPERATURES STRETCHING FROM EASTERN WYOMING/WESTERN NEBRASKA INTO NORTHEAST NEW MEXICO. UNDER THESE WARM 700MB TEMPERATURES AT THE SURFACE THERE WAS A TROUGH OF LOW PRESSURE ACROSS WESTERN NEBRASKA AND EXTREME EASTERN COLORADO/FAR WESTERN KANSAS. && .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 128 PM CDT TUE MAY 22 2012 RAP, NAM AND HRRR PLACE THE SURFACE TROUGH OF LOW PRESSURE NEAR THE COLORADO BORDER THIS EVENING. MODEL SOUNDINGS AT 00Z WEDNESDAYS IN THIS AREA INDICATING LITTLE TO NO CIN WITH A TEMPERATURES DRY ADIABATIC UP TO AROUND THE 600MB LEVEL WHERE SOME MOISTURE IS PRESENT. ALSO OBSERVING SOME INSTABILITY PRESENT AS WELL SO AM UNABLE TO COMPLETELY RULE OUT A EARLY EVENING THUNDERSTORM DEVELOPING NEAR THE COLORADO BORDER EARLY THIS EVENING. RAP AND HRRR DO HINT AT A FEW STORMS DEVELOPING AFTER 22Z NEAR THE ELKHART WHERE THE BETTER INSTABILITY ARE FORECAST TO BE LOCATED. WITH THIS IN MIND THE PREVIOUS PRECIPITATION FORECAST FOR EXTREME SOUTHWEST KANSAS STILL APPEARS TO BE ON TRACK. ALSO BASED ON THE INVERTED V TYPE OF SOUNDINGS IT DOES APPEAR THAT STRONG WINDS UP TO 60 OR 70 MPH WILL BE THE MAIN HAZARD. ANY STORM THAT DOES DEVELOP EARLY THIS EVENING IS EXPECTED TO END BEFORE MIDNIGHT BUT MAY MOVE AS FAR EAST AS LIBERAL IF THESE A COLD POOL CAN BE DEVELOPED FROM STORMS. AFTER MIDNIGHT SOUTH WINDS OF 15 TO 25 MPH ARE EXPECTED TO CONTINUE AND BASED ON TEMPERATURES EARLIER THIS MORNING WILL FAVOR OVERNIGHT LOWS AROUND 5F WARMER THAN GUIDANCE. ON WEDNESDAY A SURFACE TROUGH/DRYLINE WILL SLIDE EAST INTO WESTERN KANSAS DURING THE DAY AS A COLD FRONT DROPS SOUTH INTO NORTHWEST KANSAS BY LATE MORNING. THE COLD FRONT IS EXPECTED TO BE LOCATED FROM WEST CENTRAL KANSAS AND NORTH CENTRAL KANSAS BY THE MID AFTERNOON AS WARM MID LEVEL TEMPERATURES SPREADS EAST ACROSS SOUTHWEST KANSAS. MODEL SOUNDINGS INDICATING ANOTHER DAY OF GOOD MIXING AND BASED ON MODEL SOUNDINGS AT 00Z THURSDAY IT CURRENTLY APPEARS HIGHS AROUND 100 DEGREES WILL STILL BE POSSIBLE WEST OF THE DRYLINE. EAST OF THE DRYLINE AND NEAR THE COLD FRONT THE HIGHS WILL BE SLIGHTLY COOLER AND RANGE FROM THE LOW TO MID 90S. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 330 AM CDT TUE MAY 22 2012 MEDIUM RANGE MODELS SHOW AN UPPER LEVEL TROUGH OF LOW PRESSURE DROPPING SOUTHEAST ACROSS THE NORTHERN ROCKIES WEDNESDAY THEN TURNING EASTWARD ACROSS THE WESTERN HIGH PLAINS OF NORTHEASTERN COLORADO AND WESTERN NEBRASKA WEDNESDAY NIGHT BRINGING WIDESPREAD PRECIP CHANCES TO THE DAKOTAS SOUTHWARD INTO NEBRASKA AND POTENTIALLY NORTHERN KANSAS INTO THURSDAY. AN ATTENDANT COLD FRONT IS PROJECTED TO PUSH SOUTH INTO WESTERN KANSAS SOMETIME EARLY THURSDAY BEFORE STALLING OUT SOMEWHERE ACROSS SOUTHWEST KANSAS OR POSSIBLY EVEN NORTHERN OKLAHOMA AS ANOTHER SURFACE LOW DEVELOPS ACROSS NORTHEASTERN NEW MEXICO AND THE PANHANDLES REGION. HOWEVER, THE BEST DYNAMIC SUPPORT ALOFT WILL REMAIN JUST TO OUR NORTH ACROSS NEBRASKA AND POSSIBLY NORTHERN KANSAS WITH A STRONG +100KT UPPER LEVEL JET EXITING EASTWARD OUT OF THE ROCKIES. SHOWERS AND THUNDERSTORMS ARE LIKELY TO DEVELOP WEDNESDAY NIGHT INTO THURSDAY ALONG THE APPROACHING FRONTAL BOUNDARY FROM THE UPPER MIDWEST DOWN INTO NEBRASKA BUT ARE EXPECTED REMAIN JUST OFF TO OUR NORTH AND NORTHEAST WHERE THE BEST UPPER LEVEL SUPPORT WILL BE. FOR THE MOST PART, DRIER CONDITIONS ARE EXPECTED ACROSS SOUTHWEST AND SOUTH CENTRAL KANSAS THROUGH THE END OF THE WEEK. TEMPERATURES WILL REMAIN WELL ABOVE NORMAL WEDNESDAY AS A DEEPENING SURFACE LOW IN EXTREME EASTERN COLORADO CONTINUES TO INFLUENCE A SOUTH TO SOUTHWESTERLY LOW LEVEL FLOW INTO WESTERN KANSAS. THIS WILL ENHANCE WARM AIR ADVECTION INTO THE AREA WITH H85 TEMPERATURES IN THE MID TO UPPER 20S(C) ACROSS CENTRAL KANSAS TO JUST ABOVE 30C IN SOUTHWEST KANSAS. LOOK FOR WIDESPREAD 90S(F) WEDNESDAY AFTERNOON WITH NEAR 100F POSSIBLE IN EXTREME SOUTHWEST KANSAS. TEMPERATURES WILL DROP THURSDAY IN RESPONSE TO A COLD FRONT PUSHING ACROSS WESTERN KANSAS EARLY IN THE DAY. THIS WILL ALLOW COOLER AIR TO FILTER SOUTH INTO THE AREA WITH H85 TEMPERATURES IN THE LOW TO MID 20S(C) ACROSS CENTRAL AND SOUTHWEST KANSAS. HOWEVER, HIGHS COULD BE AN ISSUE CLOSER TO THE OKLAHOMA BORDER WHERE THE FRONTAL BOUNDARY IS EXPECTED TO STALL OUT. A WARMING TREND IS THEN LIKELY INTO THE WEEKEND AS UPPER LEVEL TROUGHING SETS UP ACROSS THE INTERMOUNTAIN WEST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1218 PM CDT TUE MAY 22 2012 A TIGHT PRESSURE GRADIENT COMBINED WITH 30-40KT WINDS IN THE 900-850MB LEVEL WILL RESULT SUSTAINED WINDS OF AROUND 25 KNOTS THROUGH THE REMAINDER OF THE DAY...ESPECIALLY AT DDC AND HYS. THESE GUSTY WINDS WILL SUBSIDE SOME AFTER SUNSET BUT BASED ON THE SURFACE PRESSURE GRADIENT SUSTAINED WIND SPEEDS OF 15 TO 20 KNOTS STILL APPEARS LIKELY. A LOW LEVEL JET IS FORECAST TO DEVELOP TOWARDS 06Z WITH WIND SPEEDS OF 50 TO 55 KNOTS BETWEEN 1500 AND 2000 FEET SO INSERTED A WIND SHEAR GROUP INTO THE TAFS OVERNIGHT. BUFR SOUNDINGS CONTINUE TO INDICATE VFR CONDITIONS OVER THE NEXT 24 HOURS. && .PRELIMINARY POINT TEMPS/POPS... DDC 65 96 62 88 / 0 10 10 10 GCK 64 98 60 85 / 10 10 10 10 EHA 62 99 60 87 / 20 10 10 10 LBL 65 102 62 88 / 10 10 10 10 HYS 65 92 63 84 / 0 10 10 10 P28 66 92 68 92 / 0 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BURGERT SHORT TERM...BURGERT LONG TERM...JJOHNSON AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1053 AM MDT TUE MAY 22 2012 .UPDATE... ISSUED AT 1049 AM MDT TUE MAY 22 2012 TEMPERATURES WARMING RAPIDLY ACROSS THE NW CWA...WITH POINTS ALREADY NEARING 90 DEGREES BEFORE 17Z. HRRR AND RUC CATCHING ONTO THIS RAPID WARMING PRETTY WELL AND TRENDED FORECAST IN THIS DIRECTION...WITH SOME VALUES NEAR 100 POSSIBLE IN THE NW PORTION OF THE COUNTY. STILL ASSESSING NEED FOR ANY FIRE HIGHLIGHTS AS LOWEST HUMIDITIES CURRENTLY IN AREA OF LIGHTEST WINDS...AND STILL SOMEWHAT UNCLEAR HOW FAR EAST DRYLINE WILL MIX. UPDATE ISSUED AT 813 AM MDT TUE MAY 22 2012 12Z RAOBS INDICATED DEEP LAYER OF NEARLY DRY ADIABATIC LAPSE RATES HAVE EXPANDED TO THE EAST FROM 24 HOURS AGO...WITH LBF OBSERVING VERY STEEP LAPSE RATES BETWEEN H8 AND H65...WITH HIGH LAPSE RATES EXTENDING UP TO H45. MIXING OUT MORNING INVERSION ONLY REQUIRES TEMPS IN THE MID 80S AND REDUCES CINH TO AROUND 50 J/KG. WITH TEMPS EXPECTED TO BE WARMER THAN THAT AND DEEPER MOISTURE EXPECTED TO THE EAST OF DRYLINE...THINK SMALL THREAT FOR THUNDERSTORMS EXISTS THIS AFTERNOON AND EVENING. NEAR SFC FORCING WILL BE STRONGEST ALONG DRYLINE...WHERE OVERALL MOISTURE PROFILES WILL BE MUCH SHALLOWER...WHICH MAY LIMIT CONVECTIVE INITIATIONS AS AVAILABLE MOISTURE FOR PARCELS IS DILUTED WITH DEEP MIXING. HAVE MODIFIED FORECAST TO ACCOUNT FOR SOME LATE AFTERNOON STORMS ALONG DRY LINE...BUT OVERALL COVERAGE WILL BE LOW. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 230 AM MDT TUE MAY 22 2012 TODAY...VERY WARM WITH RECORD OR NEAR RECORD HIGH TEMPERATURES POSSIBLE FOR MANY. FULL 850 MIXING WOULD SUPPORT HIGHS IN THE MID TO UPPER 90S. HOWEVER...MET/MAV GUIDANCE AND BIAS CORRECTED GRIDS A FEW DEGREES COOLER. THINKING THAT THE STRONG SOUTH WINDS (NOT TERRIBLY FAVORABLE FOR STRONG WARMING COMPARED TO A SOUTHWEST OR WEST DIRECTION) WHICH MAY FLIRT WITH ADVISORY CRITERIA GUSTS IN THE NORTON AND HILL CITY AREAS AND PLENTIFUL LOW LEVEL MOISTURE (DEWPOINTS IN THE 50S) MAY PUT A DENT IN THE FULL MIXING AND PRODUCE HIGHS CLOSER TO THE MET/MAV GUIDANCE. HAVE SPLIT THE TWO SCENARIOS AND GONE WITH HIGHS IN THE LOW TO MID 90S. WILL KEEP SILENT POPS GOING ALONG/NEAR THE CO/KS BORDER LATE THIS AFTERNOON WHERE LOW LEVEL FORCING AND MID LEVEL MOISTURE MAY CREATE SOME HIGH BASED CU/TCU. TONIGHT...COLD FRONT MOVES INTO THE NORTHWEST PORTION OF THE AREA BY SUNRISE. OTHERWISE...DRY WITH MILD OVERNIGHT LOWS IN THE MID 50S TO MID 60S. WEDNESDAY...STILL NO CLEAR SOLUTION AS TO WHERE THE COLD FRONT GETS HUNG UP WHICH WILL PLAY A CRUCIAL ROLE IN HIGH TEMPERATURES. RIGHT NOW IT APPEARS AREAS SOUTH OF THE INTERSTATE WILL CONTINUE ON THE HOT SIDE WITH HIGHS IN THE LOW TO MID 90S...MAYBE EVEN A BIT HOTTER. NORTH OF THE FRONT HIGHS GENERALLY IN THE 80S. POST FRONTAL MOISTURE INCREASES VERY LATE IN THE DAY AS AN UPPER TROUGH APPROACHES THE AREA. PRECIPITATION CHANCES WILL REMAIN NORTH OF THE INTERSTATE WITH THE BEST CHANCE ACROSS THE FAR NORTH/NORTHWEST PORTIONS OF THE AREA. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 230 AM MDT TUE MAY 22 2012 WEDNESDAY NIGHT-THURSDAY NIGHT...GOOD MOISTURE/JET ENERGY AND MID LEVEL FORCING SUPPORT HIGH CHANCE POPS ACROSS THE NORTHERN 1/4 OF THE AREA...SIMILAR TO PREVIOUS FORECASTS WEDNESDAY NIGHT. SHOULD HAVE A LULL THURSDAY MORNING BEFORE ANOTHER DISTURBANCE MOVES THROUGH THURSDAY AFTERNOON BRINGING ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS. SMALL CHANCES FOR PRECIPITATION CONTINUE THURSDAY NIGHT...AGAIN PRIMARILY ALONG AND NORTH OF THE INTERSTATE. HIGHS ON THURSDAY AROUND 70 IN THE FAR NORTHWEST...LOW 80S ACROSS THE FAR EAST-SOUTH. FRIDAY THROUGH MONDAY...A LONGWAVE TROUGH WILL BE IN PLACE OVER THE WESTERN CONUS THROUGH THE PERIOD...AND SEVERAL SHORTWAVE TROUGHS WILL MOVE EASTWARD AND OVER THE REGION DURING THIS TIME. UPPER LEVEL SUPPORT FROM THESE TROUGHS ALONG WITH LOW LEVEL SUPPORT FROM A COUPLE OF FRONTS WILL LEAD TO A POSSIBILITY FOR SHOWERS AND THUNDERSTORMS THROUGH MUCH OF THE PERIOD. A WARM FRONT WILL LIFT NORTHWARD ON FRIDAY NIGHT/SATURDAY MORNING...AND THE HIGHEST CHANCE FOR PRECIPITATION WILL BE IN THE NORTHERN PORTION OF THE AREA. CONDITIONS WILL BE WINDY DURING THE AFTERNOON ON SATURDAY DUE TO A SURFACE LOW DEEPENING OVER EASTERN COLORADO AND THE ASSOCIATED STRENGTHENING OF THE PRESSURE GRADIENT. A COLD FRONT IS EXPECTED TO MOVE INTO THE AREA FROM THE NORTHWEST ON SATURDAY NIGHT AND INTO SUNDAY MORNING...WITH THE ECMWF MOVING THE FRONT FURTHER EASTWARD THAN THE GFS. BOTH MODELS KEEP THE FRONT MOSTLY STATIONARY DURING THE DAYTIME ON SUNDAY...THEN MOVE IT EASTWARD ON MONDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 230 AM MDT TUE MAY 22 2012 VFR EXPECTED AT BOTH KGLD AND KMCK. SOUTH WINDS WILL INCREASE QUICKLY THIS MORNING WITH GUSTS UP TO 30 KTS OR SO AT KGLD AND 35 KTS AT KMCK AFTER 18Z. GUSTS WILL COME DOWN A BIT AFTER SUNSET ALTHOUGH SUSTAINED WINDS OF 15-20 KTS EXPECTED THROUGH EARLY WEDNESDAY MORNING BEFORE A COLD FRONT MOVES THROUGH KGLD CLOSE TO 12Z...SLIGHTLY LATER AT KMCK. && .CLIMATE... ISSUED AT 230 AM MDT TUE MAY 22 2012 RECORD HIGH TEMPERATURES FOR TODAY INCLUDE GOODLAND.....97 (1939) HILL CITY....96 (2004) MCCOOK.......97 (1964) BURLINGTON...95 (1939) YUMA.........95 TRIBUNE......100 COLBY........98 && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JRM SHORT TERM...007 LONG TERM...007/CJS AVIATION...007 CLIMATE...007
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1155 PM MDT MON MAY 21 2012 .UPDATE... ISSUED AT 1139 PM MDT MON MAY 21 2012 WINDS HAVE STEADILY INCREASED DURING THE LAST COUPLE OF HOURS ACROSS MOST OF THE AREA AS THE STRONG PRESSURE GRADIENT REMAINS IN PLACE AND THE LOW LEVEL JET DEVELOPS. WINDS WILL BE STRONGEST ALONG THE COLORADO BORDER WHERE THE WINDS FROM THE LOW LEVEL JET WILL BE ABLE TO BETTER MAKE IT TO THE SURFACE. THE WINDS SHOULD DECREASE SOME OVER THE WEST DURING THE OVERNIGHT HOURS AS THE LOW LEVEL JET MOVES SLIGHTLY TO THE EAST. OVER THE LAST FEW HOURS THE RUC HAS BACKED OFF ON FOG DEVELOPMENT OVERNIGHT...AND THE NAM HAS BECOME EVEN DRIER THAN THE PREVIOUS MODEL RUN. HOWEVER...WITH THE BREEZY SOUTH WINDS BRINGING HIGHER DEW POINTS IN DURING THE NIGHT...WILL LEAVE IN THE MENTION OF PATCHY FOG FOR ROUGHLY THE SOUTHERN HALF OF THE AREA. UPDATED SOME OF THE FORECAST FOR TOMORROW...MAINLY FOR THE WINDS OVER THE EASTERN PART OF THE AREA. INCREASED THE WINDS SOME BASED OFF THE LATEST MIXED LAYER WINDS FROM THE NAM/SREF. STILL LOOKS LIKE THE POTENTIAL IS THERE FOR CRITICAL FIRE WEATHER. HOWEVER THE QUESTION IS IF THE WINDS AND LOW RHS WILL BE COLOCATED LONG ENOUGH TO WARRANT A HIGHLIGHT. WILL LET THE MID SHIFT TAKE A LOOK AT THIS AND HOLD OFF ISSUING ANY THING AT THIS TIME. UPDATE ISSUED AT 822 PM MDT MON MAY 21 2012 INCREASED PRECIPITATION CHANCES OVER PART OF SOUTHWEST NEBRASKA AS A THUNDERSTORM APPROACHES THE AREA. STORM SHOULD EXIT THE SOUTHWEST NEBRASKA AND FAR NORTHWEST KANSAS AROUND MIDNIGHT ASSUMING IT WILL AT CONTINUE AT ITS CURRENT RATE OF SPEED AND DIRECTION. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 121 PM MDT MON MAY 21 2012 16Z WATER VAPOR IMAGERY/RUC ANALYSIS INDICATED BROAD RIDGING IN PLACE ACROSS THE CENTRAL ROCKIES AND ADJACENT HIGH PLAINS...WITH TROUGH APPROACHING THE PACIFIC NORTHWEST. AT THE SFC...TROUGH WAS IN PLACE ACROSS CENTRAL AND EASTERN COLORADO ...ROUGHLY BETWEEN KDNR AND KAKO. TO THE EAST OF THIS TROUGH...MOISTURE ADVECTION WAS INCREASING WITH AN AREA OF DEW POINTS AT OR ABOVE 50 F FROM KLIC SOUTHEAST INTO THE OKLAHOMA PANHANDLE. 12Z RAOBS AT DNR AND DDC INDICATED AREA OF STEEP MID LEVEL LAPSE RATES BETWEEN H7 AND H6...WITH A MUCH DEEPER LAYER NOTED AT DNR. MAIN CONCERN FOR THE SHORT TERM PERIODS WILL BE CONVECTIVE INITIATION CHANCES TODAY AND TEMPS/RH/FIRE WX TOMORROW. REST OF THE AFTERNOON-TONIGHT...WITH AFOREMENTIONED MOISTURE ADVECTION ALREADY ONGOING PER SFC OBS...AND NOSE OF STEEP MID LEVEL LAPSE RATES IN PLACE ALONG SFC TROUGH ACROSS EASTERN COLORADO CONFIDENCE INCREASING IN CONVECTIVE INITIATION ALONG SFC TROUGH THIS AFTERNOON...ESPECIALLY GIVEN THAT MIXED LAYER TDS ARE VERY SIMILAR TO FORECAST SFC VALUES INDICATING SOME DEPTH TO THE MOISTURE PROFILE. WHILE CONFIDENCE IN DEVELOPMENT OF THUNDERSTORMS IS HIGHER...HIGHER RES MODELS KEEPING COVERAGE FAIRLY SPARSE AND WITH LATEST HRRR JUMPING AROUND QUITE A BIT WITH TIMING AND LOCATION...DO NOT THINK POPS ABOVE THE 20-30 PERCENT RANGE WARRANTED JUST YET. WITH A LOT OF UNCERTAINTY IN THE DETAILS...HAVE GENERALLY WENT WITH BROADER COVERAGE OF POPS STARTING FIRST AROUND SFC TROUGH AROUND 20Z AND GRADUALLY SHIFTING EAST AND DIMINISHING. SOME ELEVATED INSTABILITY REMAINS THROUGH THE NIGHT WITH SOME WEAK ASCENT EXPECTED TO THE WEST OF H7 THERMAL RIDGE. PROBABILISTIC GUIDANCE NOT REALLY SUPPORTING MUCH OF A PRECIP THREAT AT THIS POINT...BUT CANNOT TOTALLY RULE OUT SOME ELEVATED OVERNIGHT STORMS AND WILL GENERALLY KEEP PREVIOUS FORECAST IN THIS REGARD. GIVEN ALREADY OBSERVED MOISTURE TRANSPORT...DO HAVE SOME CONCERNS ABOUT THE DEVELOPMENT OF FOG OVERNIGHT. WINDS SHOULD GENERALLY STAY UP WHICH WILL MINIMIZE THE THREAT SOME WHAT...BUT GIVEN EXPECTED MOISTURE PROFILE AND SREF INDICATING A SMALL THREAT FOR FOG THINK AT LEAST A PATCHY MENTION IS IN ORDER. TUESDAY...H5 RIDGE AXIS WILL SHIFT TO THE EAST THROUGH THE DAY...WITH CWA UNDER THE INFLUENCE OF LARGE SCALE FORCING FOR SUBSIDENCE THROUGH MUCH OF THE DAY. WHILE SYNOPTIC SCALE SUPPORT IS LACKING...FAIRLY STRONG AND PERSISTENT CONVERGENCE EXPECTED ALONG DRY LINE THAT WILL DEVELOP ACROSS AREA DURING THE AFTERNOON. COULD POTENTIALLY SEE A STORM OR TWO DEVELOP IN THIS AREA...BUT GIVEN LARGE SCALE PATTERN...POTENTIAL FOR A STRONG CAP AND VERY LOW PROBABILITIES FROM THE NORMALLY WET SREF DATABASE...CONFIDENCE NOT HIGH ENOUGH TO INCLUDE THUNDERSTORM THREAT AT THIS TIME. MIXED LAYER TEMPS STILL SUPPORT TEMPS IN THE 90S ACROSS MUCH OF THE AREA...ALTHOUGH THERE DOES APPEAR TO BE SOME DISCREPANCIES FOR HOW WARM THINGS WILL GET WITH SREF INDICATING A RANGE BETWEEN 97 AND AROUND 88 FOR GLD. GIVEN OVERALL PATTERN AND POTENTIAL TO BE ON MUCH DRIER SIDE OF THE DRY LINE THINK WARMER SOLUTIONS THE WAY TO AND MADE ONLY MINOR CHANGES TO GOING FORECAST. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 236 PM MDT MON MAY 21 2012 A COLD FRONT WILL DROP SOUTH TOWARDS OUR CWA TUESDAY NIGHT AS A SHORTWAVE TROUGH MOVES ACROSS THE NORTHERN PLAINS. WITH AIR MASS OVER CWA GENERALLY STABILIZING TUESDAY EVENING THUNDERSTORM CHANCES REMAIN MINIMAL AND WILL BE TIED MAINLY TO WHAT DEVELOPS DURING THE AFTERNOON. MODEL DIFFERENCES IN THE TIMING/POSITION OF THE FRONT WILL HAVE A LARGER IMPACT ON THE TEMPERATURE FORECAST WEDNESDAY WHEN IT WILL STALL OVER THE CWA AND THEN LIFT NORTH AS A WARM FRONT. ECMWF AND GFS TEND TO BE THE QUICKEST IN DEVELOPING A STRONG LEE TROUGH OVER EASTERN COLORADO...PUSHING THE FRONT NORTH BY MIDDAY. CURRENT HIGH TEMP FORECAST FOR WEDNESDAY REFLECTS A BLEND OF SOLUTIONS WITH UPPER 90S OVER SW PART OF THE CWA...AND UPPER 70S IN THE NORTHWEST. WERE THE FRONT TO LIFT QUICKER...MID-UPPER 90S COULD BE EXPECTED ACROSS A MUCH LARGER PART OF THE CWA. WITH THE SURFACE TROUGH EXPECTED TO BE OVER THE CWA BY MIDDAY...STRONGEST SURFACE GRADIENT SHOULD REMAIN EAST...SO WINDS SHOULD REMAIN BELOW RED FLAG CRITERIA. LARGE SCALE TROUGH DEVELOPS OVER THE GREAT BASIN/NORTHERN ROCKIES BY WEDNESDAY AFTERNOON...WITH A SERIES OF WEAK SHORTWAVE TROUGH MOVING JUST NORTH AND WEST OF THE CWA THROUGH NEXT WEEKEND. THE FIRST SHORTWAVE ARRIVES BY WEDNESDAY NIGHT...WITH THUNDERSTORMS POSSIBLY INITIATING OVER NORTHEAST COLORADO. BEST CHANCES WILL BE ACROSS THE NORTH AFTER MIDNIGHT WEDNESDAY NIGHT WHEN A COLD FRONT WILL MOVE INTO SOUTHWEST NEBRASKA AND STALL. I HAVE LESS CONFIDENCE FURTHER SOUTH AND EAST...HOWEVER WITH AT LEAST SOME GUIDANCE SHOWING DEVELOPMENT TOWARDS THE I-70 CORRIDOR...I FELT COMFORTABLE KEEPING SLIGHT CHANCE/CHANCE POPS IN PLACE. BY THURSDAY THIS INITIAL SHORTWAVE WILL MOVE TO THE EAST WITH SUBSIDENCE BUILDING IN OVER THE CWA IN IT WAKE. AT THE SAME TIME ANOTHER WEAK DISTURBANCE WILL BE MOVING IN FROM THE WEST BY THURSDAY AFTERNOON/NIGHT...WITH POPS INCREASING ONCE AGAIN FROM THE WEST...AND CHANCES LIMITED TO NORTH OF INTERSTATE 70. FRIDAY-MONDAY...LARGE SCALE TROUGH REMAINS IN PLACE ACROSS THE WESTERN CONUS...EVENTUALLY BREAKING DOWN AND TRANSITIONING TO A WESTERLY ZONAL PATTERN BY EARLY NEXT WEEK. RESULT WILL BE A FAIRLY ACTIVE PATTERN...WITH STORM TRACK FAVORING NORTHERN PORTIONS OF OUR CWA FOR SHOWER/THUNDERSTORM CHANCES. CONFIDENCE WAS TOO LOW TO RAISE POPS BEYOND 20/30 RANGE...CONSIDERING DIFFERENCE IN TIMING OF THESE FEATURES...AND DIFFERENCES IN POSITION OF SURFACE FEATURES AS HANDLED BY GUIDANCE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1139 PM MDT MON MAY 21 2012 VFR CONDITIONS ARE FORECAST FOR THE 6Z TAFS. WINDS WILL REMAIN BREEZY FOR KGLD OVERNIGHT AS A FAIRLY TIGHT PRESSURE GRADIENT REMAINS IN PLACE OVER THE AREA. MODELS HAVE BACKED OFF THE POTENTIAL FOR FOG...BUT WITH DEW POINTS SLOWLY CLIMBING THROUGH THE EVENING WILL CONTINUE TO KEEP THE LOW VFR VIS IN TOWARD THE EARLY MORNING HOURS FOR KGLD. ALSO KEPT IN THE MENTION OF LOW CLOUDS AT BOTH SITES AS SOUNDINGS AND CROSS SECTIONS BOTH SHOW THE POTENTIAL FOR CLOUDS TO DEVELOP IN THE IFR RANGE...ALTHOUGH NOT ENOUGH TO WARRANT AN IFR CEILING GROUP. WINDS WILL STRENGHTEN SOME DURING THE MORNING...POTENTIALLY INCREASING FURTHER DURING THE AFTERNOON AND INTO THE EVENING. && .FIRE WEATHER... ISSUED AT 121 PM MDT MON MAY 21 2012 VERY WARM AND DRY WEATHER IS EXPECTED ACROSS MUCH OF THE AREA ON TUESDAY...WITH AFTERNOON HUMIDITIES BELOW 15 PERCENT EXPECTED ALONG AND EAST OF THE COLORADO AND KANSAS STATE LINE. WESTERLY WINDS WILL GRADUALLY INCREASE IN THIS AREA TO AROUND 15 MPH IN THE AFTERNOON. WITH RECENT RAINFALL AND WINDS NOT EXPECTED TO INCREASE TO LATE IN THE AFTERNOON...OVERALL CONFIDENCE IN CRITICAL FIRE WEATHER CONDITIONS IS TOO LOW TO WARRANT A WATCH OR WARNING AT THIS POINT. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JTL SHORT TERM...JRM LONG TERM...DR AVIATION...JTL FIRE WEATHER...JRM
AREA FORECAST DISCUSSION
NWS GRAY ME
334 PM EDT TUE MAY 22 2012 .SYNOPSIS... LOW PRESSURE TO OUR SOUTH WILL PASS EAST OF THE AREA OVERNIGHT. A COLD FRONT WILL MOVE INTO NORTHERN NEW ENGLAND BY TOMORROW MORNING AND OFFSHORE LATE TOMORROW. WEAK HIGH PRESSURE WILL MOVE INTO THE AREA THURSDAY AND FRIDAY WITH A CHANCE OF SHOWERS MAINLY INLAND. A WARM AND DRY SATURDAY IS ON TAP AS HIGH PRESSURE CRESTS OVER NEW ENGLAND...THEN A COLD FRONT IS EXPECTED TO SAG FROM WEST TO EAST OVER NEW ENGLAND SUNDAY AND MONDAY. THE FRONT IS EXPECTED TO PUSH NORTHWARD THROUGH THE AREA ON TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... A LOW PRESSURE SYSTEM WAS CENTERED NEAR CAPE COD THIS AFTERNOON WITH A WARM FRONT ARCING INTO SOUTHERN NH AND MAINE. MOISTURE CONTINUED TO FLOW NORTH INTO THE AREA. AT THE SAME TIME A COLD FRONT WAS MOVING SLOWLY THROUGH SOUTHERN QUEBEC...NEW YORK...AND PENNSYLVANIA. AT THE MOMENT MOST OF THE HEAVIER SHOWERS WERE LOCATED OVER THE HIGHER TERRAIN OF NORTHERN COOS...FRANKLIN...OXFORD...AND SOMERSET. THE HRRR AND NAM12 INDICATE A BREAK OVER MUCH OF THE AREA TONIGHT EXCEPT FOR PERHAPS SOUTHERN NH AND SOUTHWEST MAINE WHERE MOISTURE CONVERGENCE IS BEST. STILL...EXPECT DRIZZLE AND WIDESPREAD FOG FOR MUCH OF THE REGION. AS THE COLD FRONT MOVES INTO THE NH MOUNTAINS AND WESTERN MAINE OVERNIGHT...SHOWERS WILL BECOME MORE WIDESPREAD. THERE IS SOME ELEVATED INSTABILITY BUT FELT THERE WAS NOT ENOUGH TO INCLUDE THUNDERSTORMS IN THE FORECAST. OVERNIGHT LOWS WILL BE IN THE MID 50S. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... LINE OF SHOWERS WILL WORK SLOWLY SOUTHEAST TOMORROW WITH THE COLD FRONT ALONG WITH ISOLATED THUNDERSTORMS. QPF AMOUNTS WILL GENERALLY BE LIGHT HOWEVER ANY CONVECTION WILL BOOST RAINFALL TOTALS. WE WILL SEE CLEARING AND EVENTUALLY PARTLY SUNNY SKIES WORK IN FROM THE NORTH BY THE AFTERNOON. THIS WILL CONTRIBUTE TO HIGH TEMPERATURES IN THE 70S. THE BOUNDARY ESSENTIALLY STALLS AND BY WASHES OUT BY EVENING AS THE LOW PRESSURE TO OUR EAST PULLS AWAY AND WE LOSE ANY UPPER LEVEL PUSH. THIS WILL ENSURE MOISTURE HANGS AROUND IN THE LOW LEVELS. ONCE THE RAIN ENDS FOG WILL DEVELOP AND BECOME DENSE AFTER DARK. WEDNESDAY NIGHT`S LOWS WILL BE IN THE LOWER 50S NORTH TO UPPER 50S SOUTH WITH NEGLIGIBLE TEMPERATURE ADVECTION. && .LONG TERM /THURSDAY THROUGH TUESDAY/...MEDIUM RANGE MODELS ARE IN FAIR AGREEMENT IN THE GENERAL PATTERN. WEAK SURFACE HIGH PRESSURE WILL REMAIN OVER THE AREA THURSDAY AND FRIDAY...BUT SHORTWAVES ALOFT MOVING THROUGH NEW ENGLAND WILL KEEP A CHANCE OF SHOWERS EACH DAY...MAINLY INLAND. ON SATURDAY THE RIDGE OVER THE SOUTHEASTERN UNITED STATES SURGES NORTHWARD INTO NEW ENGLAND FOR A VERY WARM DAY...WITH SOME LOCATIONS IN NEW HAMPSHIRE POSSIBLY TOUCHING 90 DEGREES. THEN A WEST-EAST-ORIENTED COLD FRONT WILL SAG SOUTHWARD ACROSS THE AREA SUNDAY THROUGH TUESDAY. POSITION AND STRENGTH OF THIS BOUNDARY ARE UNCERTAIN AT THIS TIME. CAN`T RULE OUT A CHANCE OF AFTERNOON THUNDERSTORMS AND SHOWERS EACH DAY. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... SHORT TERM...MOSTLY VFR CONDITIONS AT THE MOMENT WITH A BREAK IN PRECIPITATION FOR MOST TERMINALS UNTIL THE EVENING. THE EXCEPTION WILL BE PORTSMOUTH WHICH STAYS IN AN AREA OF CONVERGENCE. DRIZZLE AND FOG WILL RETURN AROUND 00Z CAUSING CEILINGS AND VISIBILITIES TO DROP AGAIN TO IFR/LIFR CATEGORIES. A COLD FRONT WILL MOVE IN FROM THE WEST TONIGHT WITH RAIN CHANCES INCREASING FROM NW TO SE THROUGH TOMORROW. LONG TERM...OCCASIONAL MVFR CONDITIONS IN SCATTERED SHOWERS THURSDAY AND FRIDAY. VFR SATURDAY THEN POSSIBLE MVFR IN ANY THUNDERSTORMS SUNDAY. && .MARINE... SHORT TERM...HAVE ISSUED A SCA FOR HIGH SEAS BEGINNING TONIGHT AND ENDING TOMORROW EVENING AS LOW PRESSURE PASSES TO THE EAST. LONG TERM...NO SIGNIFICANT FEATURES DURING THE PERIOD. && .FIRE WEATHER... SCATTERED SHOWERS AND HIGH RELATIVE HUMIDITIES WILL LAST THROUGH FRIDAY WITH A COLD FRONTAL PASSAGE AND MORE SUBSTANTIAL RAINS SATURDAY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 6 PM THIS EVENING TO 8 PM EDT WEDNESDAY FOR ANZ150-152-154. && $$ HANES/ST.JEAN
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
234 AM EDT TUE MAY 22 2012 .SYNOPSIS... LOW PRESSURE AND UNSETTLED CONDITIONS WILL PERSIST ACROSS THE AREA THROUGH MID WEEK. HIGH PRESSURE BUILDS INTO THE AREA LATE THIS WEEK INTO THE HOLIDAY WEEKEND. && .NEAR TERM /THROUGH TODAY/... UPDATE TO ADD 30 PERCENT CHC SHOWERS/ISOLATED THUNDER MOST AREAS WEST OF THE CHESAPEAKE. HRRR AND OTHER HIGH RES MODELS INDICATE CONVECTION OVERNIGHT IN AN AREA THAT HAS SLIGHTLY NEGATIVE LI/S. AS OF 03Z...SHOWERS WERE OVER BRUNSWICK COUNTY AND APPROACHING LUNENBURG AND MECKLENBURG COUNTY FROM THE WEST. LEFT SLGT CHC SHOWERS ERN PORTIONS WHERE THE ATMPOSPHERE IS RELATIVELY STABLE. PREVIOUS DISCUSSION... MOST PCPN HAS WEAKENED / DISSIPATED SINCE SUNSET WITH ONLY A FEW SHOWERS OVER I95 CORRIDOR NORTH OF RICHMOND. NOW WATCHING BAND OF SHOWERS / TSTRMS FROM LYH-DAN. TUFF CALL ON JUST HOW FAR EAST THEY GET NEXT FEW HOURS AS SHORT RANGE MODELS DIFFER A BIT ON HOW LONG THEY SURVIVE. THUS...HAVE ADDED ISLTD THUNDER TO EXTREME WESTERN COUNTIES NEXT FEW HOURS FOR ANY CELL THAT DOES MOVE EAST. OTW...ENUF MOISTURE IN PLACE FOR AT LESAT ISOLATED SHOWERS FOR THE REST OF THE NIGHT...ESPECIALLY ACROSS WESTERN HALF OF FA DUE TO LINGERING TROF. ADDED PATCHY FOG ALONG THE EASTERN SHORE. LATER UPDATES MAY HAVE TO EXPAND THE FOG THREAT TOWARD SUNRISE. WARM AND HUMID. LOWS 60-65. && .SHORT TERM /TONIGHT THROUGH THURSDAY/... UNSETTLED CONDS...NOT DUE TO TS ALBERTO...WILL CONTINUE THRU THE SHORT TERM PERIOD WITH THE AFOREMENTIONED UPR-LVL TROF STILL IN PLACE ALONG THE EASTERN SEABOARD. THIS WILL LEAD TO PERIODIC CHANCES FOR SHOWERS AND STORMS AS MOIST S/SW FLOW CONTINUES. FOR TUE...SFC TROF WILL BE SITUATED OVR WESTERN PORTIONS OF THE FA WHERE HIGHEST POPS (50%) WERE PLACED...30-40% ELSEWHERE. TEMPS CLIMB INTO THE UPR 70S TO LWR 80S UNDER A MSTLY CLDY SKY. RAIN MAY LINGER INTO TUE NGT...WITH THE BEST CHC AGAIN OVR WESTERN AREAS. UPR-LVL TROF CUTS OFF FROM THE MEAN FLOW TUE NGT INTO WED AS A POTENT S/W DIVES DOWN THE TROF BASE. THE CENTER OF THE RESULTING UPR-LVL LOW WILL CENTER ITSELF NEAR THE MID ATLANTIC WED INTO THU...WITH CHANCES FOR RAIN EACH DAY. BEST CHANCE FOR RAIN DURING THE PERIOD WILL BE WED (LIKELY POPS FOR NW QUADRANT OF FA) WITH A SFC TROF OVR THE MID ATLANTIC...DECENT FORCING ALOFT...AND A VERY MOIST ATM. SEASONABLE TEMPS CONTINUE WED AND THU...HIGHS STILL IN THE UPR 70S TO LWR 80S. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... THE LATEST NUMERICAL GUIDANCE IS SUGGESTING THAT THE PERSISTENT UPPER LOW MAY LINGER INTO FRIDAY. HOWEVER...AT THIS POINT NOTHING MORE THAT A SLIGHT CHANCE POP IS NECESSARY. AN UPPER HIGH THEN BUILDS OVER THE OHIO VALLEY FOR THE MEMORIAL DAY WEEKEND. GIVEN WHERE THE HIGH SETS UP IT IS POSSIBLE SOME CONVECTION COULD ROUND THE TOP OF THE RIDGE AND APPROACH THE LOCAL AREA IN MID-LEVEL NNW FLOW. THE LARGE MAJORITY OF THE TIME IS EXPECTED TO BE DRY AND THERE IS BASICALLY NO SKILL IN FORECASTING MCS ACTIVITY IN THE MEDIUM RANGE. TEMPERATURES SHOULD BE ABOVE SEASONAL AVERAGES WITH HIGHS IN THE MID 80S TO NEAR 90 (SLIGHTLY COOLER ALONG THE COASTS WITH LIGHT ONSHORE FLOW). LOW TEMPERATURES SHOULD GENERALLY BE IN THE 60S. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... VFR CONDITIONS AT MOST TERMINALS AS OF 06Z...WITH THE EXCEPTION OF SOME MVFR/TEMPO IFR CONDS AT KSBY/KECG. WEAK LOW PRESSURE PERSISTS OVER THE REGION WITH MOSTLY LIGHT WINDS FROM THE E-SE. BIGGEST CONCERN EARLY THIS MORNING IS W/THE CHANCE OF MORE WIDESPREAD IFR CONDITIONS DUE TO PLENTY OF LOW LEVEL MOISTURE. ACCORDINGLY HAVE GONE WITH LOWERING CIGS TO LOW MVFR/IFR RANGE AT RIC/ORF/PHF TOWARDS DAWN. HAVE ALSO ALLOWED FOR SOME PATCHY DENSE FOG AT ALL SITES AFTER 08Z THROUGH JUST AFTER SR. VFR CONDITIONS ARE EXPECTED BY MID TO LATE MORNING AS WINDS SHIFT TO THE S-SW DURING THE LATE NIGHT TUESDAY AND OVERNIGHT HOURS WED MORNING. MORE SHOWERS AND TSTMS POSSIBLE FOR TUE AFTN/EVENING AFTER 18-20Z THROUGH EARLY EVENING AS WEAK INSTABILITY CONTINUES OVER THE REGION, COURTESY OF APPROACHING UPPER TROUGH FROM THE WEST. OUTLOOK...SLOW MOVING UPPER SYSTEM WILL RESULT IN CONTINUED UNSETTLED WEATHER WED AND THU...WITH THE POTENTIAL FOR FLIGHT RESTRICTIONS IN PATCHY FOG EACH MORNING AND IN SCT CONVECTION EACH AFTN. CLEARING FINALLY BUILDS IN FROM THE WEST FOR FRIDAY AND INTO THE UPCOMING HOLIDAY WEEKEND. && .MARINE... THE LATEST SURFACE ANALYSIS SHOWS A RATHER NEBULOUS SURFACE PATTERN ACROSS THE LOCAL MARNIE AREA AND HENCE WEAK FLOW. THIS GENERAL FLOW PATTERN SHOULD CONTINUE THROUGH MUCH OF THE WEEK WITH S OR SE FLOW AOB 10KT. AN AREA OF LOW PRESSURE (NOT TS ALBERTO) PRESENTLY WELL EAST OF THE NC COAST WILL MOVE NNE ON A TRAJECTORY TOWARD NS THROUGH TUESDAY. WNA WAVE SHOWS SWELL ASSOCIATED WITH THIS LOW AFFECTING THE MARINE AREA TUESDAY INTO TUESDAY NIGHT WITH SEAS AOA 5FT GENERALLY OUT PAST 5-10NM. AN SCA FOR HAZARDOUS SEAS WILL BE RAISED FROM 6AM TUESDAY TO 6AM WEDNESDAY. OTHERWISE...SEAS SHOULD DROP BELOW SCA FOR THE REMAINDER OF THE WEEK. UNSETTLED CONDITIONS SHOULD PERSIST MUCH OF THE WEEK WITH A CHANCE FOR MAINLY AFTERNOON AND EVENING THUNDERSTORMS. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 6 AM THIS MORNING TO 6 AM EDT WEDNESDAY FOR ANZ650-652-654-656-658. && $$ SYNOPSIS...MAS NEAR TERM...MPR/LSA SHORT TERM...MAS LONG TERM...AJZ AVIATION...MAM MARINE...AJZ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
744 PM EDT WED MAY 23 2012 .SYNOPSIS... ISSUED AT 427 PM EDT WED MAY 23 2012 WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH OVER THE NW CONUS AND A RIDGE FROM THE CNTRL GREAT LAKES INTO NRN ONTARIO RESULTING IN SW FLOW FROM THE CNTRL PLAINS TO THE UPPER MS VALLEY AND LAKE SUPERIOR. AT THE SFC...SRLY WINDS WERE INCREASING ACROSS THE REGION AHEAD A COLD FRONT EXTENDING THROUGH THE ERN DAKOTAS FROM LOW PRESSURE OVER SRN MANITOBA. AN AREA OF TSRA WAS MOVING NE THROUGH N CNTRL MN SUPPORTED A SHRTWV NEAR THE NOSE OS STRONG 925-850 MB THETA-E ADVECTION. OVER UPPER MI...VIS LOOP AND SFC OBS SHOWED CONSIDERABLE HIGH CLOUDS IN THE BROAD WAA PATTERN AHEAD OF THE FRONT. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 427 PM EDT WED MAY 23 2012 TONIGHT...AS A SHRTWV OVER NW MN LIFTS TO THE NE AND THE NEXT SIGNIFICANT UPSTREAM SHRTWV OVER NEVADA ROTATES THROUGH THE WRN TROF...ANOTHER SFC LOW WILL DEVELOP IN THE PLAINS AND MOVE NNEWD ON COLD FNT ATTENDANT TO FIRST SFC LO DRIFTING THRU NW ONTARIO. EXPECT THAT THE GREATEST CHANCE FOR SHRA/TSRA WILL REMAIN CLOSER TO THE FRONT AND NEAR THE AXIS OF GREATER MOISTURE/INSTABILITY OVER MN AND FAVORABLE UPPER LEVEL DIV WITH THE RIGHT ENTRANCE OF THE JET OVER NW ONTARIO. SO...THE NAM/REGIONAL GEM/ECMWF WERE PREFERRED WITH THE SHRA/TSRA PLACEMENT COMPARED TO THE GFS WHICH SEEMED OVERLY AGGRESSIVE IN PUSHING THE PCPN TO THE EAST. THURSDAY...THE MAIN SHRTWV LIFTS OUT OF THE PLAINS TO THE UPPER MS VALLEY SUPPORTING A CONSOLIDATED SFC LOW TO NEAR KDLH BY 00Z/FRI. GIVEN THE STRENGTHENING DYNAMICS AGAIN TO THE WEST...CONTINUED TO DELAY THE EASTWARD PROGRESSION OF THE SHRA/TSRA INTO UPPER MI TIL MAINLY LATE IN THE DAY. MLCAPE VALUES TO AROUND 1K J/KG WITH AFTERNOON HEATING AND SFC DEWPOINTS NEAR 60 WILL SUPPORT TSRA CHANCES FROM IWD-CMX...MAINLY AFT 21Z. WITH INVERTED V LOOK TO THE SOUNDINGS AND VERY STRONG MAINLY UNIDIRECTIONAL WIND FIELD (700 MB WINDS TO NEAR 70KT)...EXPECT THAT DAMAGING WINDS WILL BE THE MAIN HAZARD WITH ANY TSRA. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 427 PM EDT WED MAY 23 2012 MAIN CONCERN FOR THE LONG TERM PERIOD IS THE SEVERE WEATHER POTENTIAL AT THE BEGINNING OF THE PERIOD. STATIONARY FRONT WILL BE SETUP OVER WRN LK SUPERIOR...WHILE A FAIRLY POTENT SHORTWAVE PUSHING NE ACROSS AT LEAST THE WRN HALF OF THE CWA THURS NIGHT. THIS WILL LEAD TO ONGOING CYCLOGENESIS OVER NW WI DURING THE LATE AFTERNOON AND THE LOW MOVING NNE ACROSS WRN LK SUPERIOR DURING THE EVENING. EXPECT THUNDERSTORMS TO BE ONGOING OVER NW WI AND FAR WRN LK SUPERIOR AT THE START OF THE PERIOD AND THEN MOVE E AND NE AS THE COLD FRONT PUSHES THROUGH THE CWA DURING THE NIGHT. WITH THE STRONG WINDS ALOFT AND THE CYCLOGENESIS...FEEL THAT THERE IS A DECENT CHANCE OF SEVERE WEATHER OVER THE WRN HALF OF THE CWA TOMORROW EVENING. THERE IS A VERY THIN CORRIDOR OF MLCAPE VALUES APPROACHING 500-1000 J/KG OVER THE WRN THIRD OF THE CWA AND INSTABILITY MAY BE THE MAIN LIMITING FACTOR AS STORMS MOVE INTO THE CWA. CAPE FAIRLY SKINNY...NCAPE VALUES AROUND 0.1...SO DON/T EXPECT MUCH MORE THAN MARGINALLY SEVERE HAIL. WIND APPEARS TO BE BIGGEST THREAT WITH THE STORMS. INVERTED V LOOK TO THE SOUNDINGS OVER THE WEST AND DCAPE VALUES OF 600-800 J/KG. STRONG WINDS ALOFT...APPROACHING 70-80KTS AT H700 AND 40-50KTS JUST A COUPLE HUNDRED FEET ABOVE THE SFC...WILL BE AIDED BY A POCKET OF DRY H700-500 AIR AND STEEPER LAPSE RATES. THIS...COMBINED WITH STORM MOTION TO THE NNE AT 65-70KTS ALL POINT TO THE POTENTIAL FOR DAMAGING WINDS WHERE THUNDERSTORMS...AND POTENTIALLY EVEN SHOWERS OCCUR. WITH THE LOW DEVELOPING ALONG THE FRONT POTENTIALLY AFFECTING THE LLVL WIND FIELD...COULD SEE SOME LLVL BACKING OF THE WINDS AND PRODUCE SOME ROTATING UPDRAFTS AND SUPERCELLS...ESPECIALLY OVER NW WI. BUT THE EXPECTED DRY LLVL AIR HELPING PRODUCE AN INVERTED V AND LCL HEIGHTS TOWARDS 3-3.5KFT SHOULD LIMIT TORNADO POTENTIAL THIS FAR N. CURRENT THOUGHT IS BEST CHANCES FOR SEVERE SHOULD BE FROM BARAGA/IRON COUNTIES AND WEST...BUT WITH THE STORM MOTIONS...COULD POTENTIALLY AFFECT MARQUETTE/DICKINSON/MENOMINEE COUNTIES BEFORE HEADING OVER LK SUPERIOR. ADDED DAMAGING WIND THREAT TO THE GRIDS AND MENTIONED IN THE HWO. THIS MATCHES UP WELL WHERE SPC HAS A SLIGHT RISK...WITH HATCHED AREA JUST TO THE SW OF THE CWA. AS THE LOW QUICKLY LIFTS NE...EXPECT BEST FORCING TO QUICKLY DEPART OVERNIGHT AND PULL FORCING WITH IT. IN ADDITION...AS THE COLD FRONT PUSHES EAST INTO THE CNTRL/ERN CWA...THE CAPPING BECOMES STRONGER. WITH THE COMBINATION OF LOOSING FORCING AND MORE UNFAVORABLE ENVIRONMENT...EXPECT THE SHOWERS/THUNDERSTORMS TO DIMINISH AS THEY MOVE INTO THE CNTRL/ERN CWA. 09Z SREF ALSO SHOWING THIS DIMINISHING TREND IN THE 3HR CALIBRATED THUNDERSTORM PROBS...AS THE SHOWERS/THUNDERSTORMS PUSH TO THE NE OVER LK SUPERIOR DURING THE OVERNIGHT HOURS. EXPECT GUSTY SE WINDS IN THE EVENING AHEAD OF THE LOW AND OVER THE KEWEENAW OVERNIGHT BEHIND THE LOW/FRONT. BUMPED UP WINDS SIGNIFICANTLY OVER THE KEWEENAW BEHIND THE LOW AND FRONT...WITH THE STRONG WINDS JUST ABOVE THE SFC /NAM SHOWING 60KTS AT 1.5KFT/. IN ADDITION...GOOD ISALLOBARIC COMPONENT TO THE WINDS OVER THE WEST OVERNIGHT WITH THE INTENSIFYING LOW PUSHING NE. ONLY CONCERN FOR GOING MORE THAN 30-35KTS AT THIS POINT IS AFFECT OF COOLER WATER TEMPS...BUT THAT MAY NOT HAVE MUCH EFFECT OVER THE HIGHER TERRAIN. FRI...GUSTY WRLY WINDS...30-35KTS...IN THE MORNING BEHIND THE LOW. DRIER AIR MOVING IN AND H700 CAP SHOULD LIMIT DEVELOPMENT EVEN WITH WEAK MID-LVL WAVE MOVING THROUGH. DEEP MOISTURE IS LIMITED AND ML/MU CAPE VALUES ARE BELOW 100 JKG WOULD LEAD TO LITTLE/NO PCPN CHANCES. LATEST NAM RUN HAS BACKED OFF ON PCPN AND WILL FOLLOW SUIT WITH REMOVING SLIGHT CHANCES. WILL KEEP SKIES PARTLY/MOSTLY CLOUDY DURING THE AFTN WITH EXPECTED DIURNAL CU DEVELOPMENT. MIXING TO H750 WOULD YIELD HIGHS IN THE 70S...WITH THE HIGHEST VALUES IN THE FAVORED DOWNSLOPE AREAS OF THE CNTRL. WITH THE GUSTY WINDS AND DEEPER MIXING INTO THE LIMITED MOISTURE ALOFT...EXPECT RH VALUES TO FALL TO 30 PERCENT. FIRE WX CONCERNS MAINLY OVER THE CNTRL...WHERE LESS RAIN IS EXPECTED ON THURS NIGHT. FRI NIGHT...WEAK HIGH PRESSURE RIDGE FROM HIGH JUST N OF MN. SFC LOW DEVELOPING IN THE CNTRL PLAINS IN RESPONSE TO DEEP UPPER TROUGH OVER THE WRN CONUS WILL BEGIN TO PUSH A WARM FRONT N TOWARDS THE UPPER GREAT LAKES LATE FRI NIGHT. COULD PRODUCE A FEW SHOWERS TOWARDS THE WI BORDER LATE. CWA WILL BE ON THE E SIDE OF THE UPPER RIDGE AXIS STRETCHING FROM THE OHIO VALLEY TO LK WINNIPEG UNTIL SUN NIGHT. STILL SEVERAL WEAK DISTURBANCES PUSHING THROUGH THE FLOW SAT AFTN THROUGH SUN NIGHT. THE WARM FRONT WILL CONTINUE TO SLOWLY PUSH NE ON SAT...AS IT BATTLES THE HIGH THAT WILL HAVE MOVED EAST OVER ONTARIO. PCPN CHANCES ON SAT WILL LARGELY DEPEND ON HOW FAR N THE FRONT WILL PUSH. BEST CHANCES LOOK TO BE ON SAT NIGHT INTO SUN...AS THE FRONT MOVES INTO NRN WI AND FINALLY INTO UPPER MI BY SUN AFTN. THIS WILL PUT THE BEST WAA FOCUS OVER THE CWA. THERE ARE DECENT MID LEVEL LAPSE RATES...BUT ELEVATED CAPES ARE NOT TOO IMPRESSIVE...SO HAVE CAPPED THUNDER TO CHANCES FOR SAT NIGHT INTO SUN. WITH THE CONVECTION LIKELY TO BE ELEVATED...THE MAIN THREAT WOULD BE SMALL HAIL AND HEAVY RAIN. CWA WILL BE UNDER THE WARM SECTOR LATE SUN AFTN AND INTO SUN NIGHT...WITH MODELS DIVERGING WITH THE HANDLING OF THE LOW HEADING INTO THE FIRST PART OF NEXT WEEK. 12Z GFS SHOWS THE LOW CONTINUING NNE INTO SRN CANADA ON SUN NIGHT AND MONDAY WHILE PUSHING COLD FRONT ACROSS UPPER MI ON MON. 00Z ECMWF ON THE OTHERHAND DISSIPATES THE LOW OVER THE CWA AND THEN SLOWLY SLIDES IT EAST THROUGH TUES. AFTER A MORE ACTIVE PERIOD...OVERALL TREND LOOKS TO BE TOWARDS A SLIGHTLY DRIER/QUIET WEATHER TOWARDS THE MIDDLE OF NEXT WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 743 PM EDT WED MAY 23 2012 STRONG WINDS AND LLWS WILL BE A CONCERN WHILE VFR CONDITIONS DOMINATE THROUGHOUT THE FORECAST PERIOD. EXPECT CONDITIONS TO DECOUPLE SOMEWHAT TONIGHT AS STRONG LOW-LEVEL WINDS DEVELOP. LLWS WILL BE STRONG BUT GENERALLY UNIDIRECTIONAL...WITH WIND SPEEDS 1-2KFT AGL POSSIBLY REACHING 55-60KTS AFTER MIDNIGHT. LOW-LEVEL WIND FIELDS STAY STRONG THROUGH THE DAY ON THURSDAY AHEAD OF AN APPROACHING COLD FRONT. ON THURSDAY...DECENT DAYTIME HEATING WILL ALLOW STRONG WINDS TO MIX TO THE SURFACE. CURRENTLY HAVE IWD AND SAW WITH GUSTS AROUND 30KTS...BUT WOULD NOT BE SURPRISED TO SEE SOME GUSTS UP TO 40KTS LATE IN THE AFTERNOON WITH 50-60KT WINDS AROUND 3KFT. THUNDERSTORMS BEGIN TO AFFECT IWD AND CMX BY 00Z FRIDAY. CURRENT EXPECTATION IS A STRONG TO SEVERE LINE OF THUNDERSTORMS AHEAD OF THE COLD FRONT...WITH DAMAGING WINDS POSSIBLE. CONFIDENCE OF STORMS OCCURRING IS HIGH...BUT CONFIDENCE IN TIMING IS LOW...SO JUST GAVE A GENERAL TIMING IN THE TAF. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 427 PM EDT WED MAY 23 2012 LOW PRESSURE OVER S MANITOBA WILL PUSH INTO ONTARIO TONIGHT AND THURSDAY...AS AN ADDITIONAL LOW MOVES FROM THE CENTRAL PLAINS TO W LS FRIDAY AFTERNOON. EXPECT THE LOW TO CONTINUE A NE TRACK ACROSS ONTARIO THROUGH FRIDAY...WITH A TROUGH LINGERING ACROSS LAKE SUPERIOR. STRENGTHENING S WINDS WILL PREVAIL AHEAD OF THIS SYSTEM TONIGHT THROUGH THURSDAY. WITH A STABLE TEMPERATURE PROFILE THE STRONGEST WINDS...EXPECT THE STRONGEST ACROSS THE TALLER OBSERVING PLATFORMS ACROSS CENTRAL LAKE SUPERIOR. HIGH PRESSURE OVER CENTRAL CANADA FRIDAY NIGHT WILL SLIDE ACROSS ONTARIO SATURDAY...BEFORE SETTLING ACROSS HUDSON BAY ON SUNDAY. AS A RESULT...A RIDGE WILL SLIDE ACROSS LS SATURDAY...WITH LIGHTER WINDS TAKING HOLD. A LOW ACROSS THE CENTRAL PLAINS WILL FILL ACROSS MN SUNDAY INTO SUNDAY NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...JLB SHORT TERM...JLB LONG TERM...SRF AVIATION...TK MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
433 PM EDT TUE MAY 22 2012 .SYNOPSIS... ISSUED AT 430 PM EDT TUE MAY 22 2012 WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM THE GULF OF ALASKA INTO THE NW CONUS AND A FLAT DOWNSTREAM RIDGE FROM THE SRN PLAINS TO THE UPPER MS VALLEY RESULTING IN WRLY FLOW THROUGH THE NRN GREAT LAKES. AT THE SFC...A RIDGE EXTENDED FROM JAMES BAY THROUGH ERN LAKE SUPERIOR AND LAKE MI INTO THE MID MS VALLEY. SRLY WINDS WERE INCREASING FROM THE PLAINS INTO MN AHEAD OF LOW PRES OVER THE WRN DAKOTAS. RADAR AND SFC OBS INDICATED AN AREA OF MAINLY VIRGA/-SHRA/SPRINKLES OVER WRN UPPER MI SUPPORTED BY 305K-310K ISENTROPIC LIFT. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 430 PM EDT TUE MAY 22 2012 TONIGHT...EXPECT THAT THE -SHRA/SPRINKLES WILL CONTINUE TO DIMINISH AS THEY MOVE TO THE EAST LATE THIS AFTERNOON AND EVENING. WITH THE INCREASED CLOUD COVER AND SOUTHERLY WINDS TONIGHT...TEMPS WILL ONLY DROP OFF INTO THE MID 40S INLAND AND LOWER TO MID 50S FOR DOWNSLOPE LOCATIONS OVER THE WEST HALF. WEDNESDAY...AS THE HIGH OVER THE LAKE AND THE PLAINS TROUGH SHIFTS TO THE EAST...THE GRADIENT WILL INCREASE ACROSS UPPER MICHIGAN. THE MODELS WERE IN GOOD AGREEMENT IN KEEPING THE MOISTURE/LIFT AHEAD OF THE MID LEVEL AND SFC TROUGH TO THE WEST...GRADUALLY SHIFTING INTO WRN LAKE SUPERIOR LATE. WITH THE WAA AND SUNSHINE...TEMPS SHOULD CLIMB INTO THE MID AND UPPER 70S INLAND WITH COOLER READINGS NEAR LAKE MICHIGAN. MIXING SHOULD ALSO ALSO A DECENT PORTION OF THE 25-30 KT SRLY 925 MB WINDS TO MIX TO THE SFC. INCREASED WILDFIRE DANGER IS EXPECTED WITH THE COMBINATION OF 15 TO 20 MPH SFC WINDS AND GUSTS TO 30 MPH ALONG WITH RH VALUES DROPPING TO AROUND 30 PERCENT. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 430 PM EDT TUE MAY 22 2012 THE PERIOD STARTS 00Z THU WITH A 500MB RIDGE OVER THE E COAST AND LOWER GREAT LAKES...AND A 500MB TROUGH OVER FROM HUDSON BAY TO SRN SASK TO THE CENTRAL ROCKIES. THIS PUTS THE CWA UNDER SW FLOW ALOFT. AT THE SFC...A 994MB LOW WILL BE OVER FAR WRN ONTARIO...WITH A TROUGH/COLD FRONT EXTENDING SW TO A 986MB LOW OVER ERN CO/WRN KS. SFC HIGH PRESSURE OVER THE ERN SEABOARD COMBINED WITH LOW PRESSURE TO OUR W WILL MAKE FOR GUSTY SLY WINDS...WITH 850MB WINDS OF 35-50KTS. MOST OF THE MOISTURE OVER THE CWA WILL EXIST OVER FAR WRN LAKE SUPERIOR AT 00Z THU...WITH 1000-500MB RH AROUND 30 PERCENT OVER CENTRAL UPPER MI. 850MB TEMPS AROUND 18C AT 00Z THU WILL MAKE FOR WARMER THAN NORMAL TEMPS. CONVECTION SHOULD BE ONGOING OVER WRN LAKE SUPERIOR AS LOW LEVEL WARM AIR/MOISTURE ADVECTION NOSES INTO THE VERY MOIST AIRMASS. BY 12Z THU...THE ONTARIO SFC LOW WILL HAVE MOVED TO JAMES BAY...WHILE THE CO/KS LOW WILL HAVE BECOME AN ELONGATED LOW FROM KS TO CENTRAL MN AS AN UPPER SHORTWAVE TROUGH MOVES TO CENTRAL NE. PRECIP WED NIGHT SHOULD CONTINUE OVER WRN LAKE SUPERIOR AS LOW LEVEL WARM AIR/MOISTURE ADVECTION CONTINUES TO BE FOCUSED OVER THIS AREA. WARM AIR ADVECTION DOES LOOK TO SPREAD ACROSS MOST OF THE CWA...BUT WITH VERY DRY AIR OVER ALL BUT FAR WRN UPPER MI...PRECIP WILL NOT FOLLOW IT E. THE 12Z/22 GFS CONTINUES TO MOVE THE MOISTURE /AND THEREFOR THE PRECIP/ A LITTLE FARTHER E /OVERSPREADING MUCH OF WRN UPPER MI/ WED NIGHT...BUT WILL GO WITH MOST OTHER MODELS IN KEEPING IT FARTHER W...WHICH MAKES SENSE GIVEN DRY CONDITIONS AND RIDGING IN PLACE TO THE E. WED NIGHT LOW LOOK QUITE WARM GIVEN 850MB TEMPS STAYING AROUND 17C AND BREEZY S/SSE SFC WINDS. LOW OVER WRN UPPER MI...WHERE IT WILL BE CLOUDIER...MAY NOT FALL BELOW 60...WITH LOWS AOA 50 ELSEWHERE. FOR THU...THE SHORTWAVE MOVES TO NEAR WRN UPPER MI LATE IN THE DAY...BRINGING 992MB SFC LOW TO FAR WRN LAKE SUPERIOR/MN ARROWHEAD BY 00Z FRI. PRECIP WILL REMAIN CONFINED TO FAR WRN UPPER MI/WRN LAKE SUPERIOR THROUGH 00Z FRI...WITH STRONG SLY LOW LEVEL FLOW CONTINUING TO BRING DRY AIR TO CENTRAL AND ERN UPPER MI. HIGH TEMPS THU LOOK TO BE WARMEST OVER THE WRN HALF OF THE U.P. /EXCEPT NEAR IWD DUE TO INCREASED CLOUD COVER/ IN THE MID TO UPPER 80S. OVER ERN UPPER MI...HIGHS WILL RANGE FROM THE UPPER 60S NEAR LAKE MI TO AROUND 80 NEAR LAKE SUPERIOR. SFC WIND GUSTS AOA 30MPH LOOK COMMON ON THU...WHICH WILL TURN ATTENTION TO FIRE WEATHER AS RH FALLS TO AROUND 30 PERCENT OVER ALL BUT FAR WRN UPPER MI AND NEAR LAKE SUPERIOR. MUCAPE AROUND 1000J/KG...0-1KM BULK SHEAR AROUND 40KTS...AND 0-6KM BULK SHEAR AOA 50KTS WILL BE SUPPORTIVE OF STRONG TO SEVERE THUNDERSTORMS OVER WESTERN UPPER MICHIGAN LATE THU AFTERNOON/EVENING...MAINLY ALONG AND JUST BEHIND THE COLD FRONT. MAIN SEVERE WX THREATS WOULD BE LARGE HAIL/DAMAGING WINDS. BY 06Z FRI...MODELS SHOW THE SHORTWAVE/SFC LOW NEAR NRN LAKE SUPERIOR...WITH THE COLD FRONT OVER CENTRAL OR WRN UPPER MI. THIS SHOULD BRING WIDESPREAD SHOWERS AND THUNDERSTORMS TO WRN UPPER MI...BUT COVERAGE WILL DIMINISH AS PRECIP HEADS E INTO THE DRIER AIR IN PLACE. COLD FRONT SHOULD BE EXITING ERN UPPER MI SHORTLY AFTER 12Z FRI...WITH THE GFS SHOWING QUICKER EASTWARD PROGRESS WITH THE FRONT THAN MOST OTHER MODELS...SO WILL NOT USE AS FAST A SOLUTION AS THE GFS. 500MB HIGH BUILDS INTO THE SRN MISSISSIPPI VALLEY BY 12Z SAT AS A 500MB LOW PUSHES INTO THE SW CONUS. A RIDGE FROM THE UPPER HIGH WILL EXTEND OVER THE DAKOTAS AND MONTANA AT 12Z SAT...BUT WILL MOVE TO THE WRN CWA BY 18Z SUN AS THE UPPER LOW MOVES TO MT. THIS BRINGS THE COLD FRONT BACK N AS A WARM FRONT LATE SAT INTO SUN AS A 998MB SFC LOW MOVES TO SD. PRECIP LOOKS TO MOVE S TO N ACROSS THE CWA SAT NIGHT THROUGH SUN. MODELS BEGIN TO QUICKLY DIVERGE ON A SOLUTION PAST SUN AS THE 00Z/22 ECMWF KEEPS THE UPPER LOW OVER MT/SRN SASK THROUGH MON NIGHT...ANS THE GFS MOVES IT TO JAMES BAY BY 12Z TUE. WILL USE CONSENSUS OF MODELS FOR SAT THROUGH NEXT TUE...WITH THE FORECAST BECOMING INCREASINGLY UNCERTAIN SUN NIGHT THROUGH TUE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 725 AM EDT TUE MAY 22 2012 ALTHOUGH THERE WL BE AN INCRS IN MID CLD AT MAINLY IWD/CMX...EXPECT VFR CONDITIONS TO PREVAIL WITH PLENTY OF LLVL DRY AIR. A TIGHTENING PRES GRADIENT OVER FAR WRN UPR MI WL CAUSE S WINDS TO TURN GUSTY WITH DAYTIME HEATING AT IWD TODAY. WITH NOCTURNAL COOLING/A MORE STABLE THERMAL PROFILE TNGT...EXPECT LLWS AT THAT SITE UNDER THE SHARPER PRES GRADIENT. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 430 PM EDT TUE MAY 22 2012 SRLY WINDS WILL INCREASE TONIGHT INTO WED AS HIGH PRES SHIFTS TO THE EAST. EXPECT S WINDS UP TO 25-30 KTS WED INTO THURSDAY NIGHT UNDER SHARPENING PRES GRADIENT BETWEEN THE DEPARTING HIGH AND A SLOWLY APPROACHING LO PRES TROF FROM THE W. THE STRONGEST WINDS ARE EXPECTED OVER CENTRAL LAKE SUP...WHERE TERRAIN INFLUENCE MAY ENHANCE THE S WIND. THE WIND AT HIGHER PLATFORMS SUCH AS STANNARD ROCKS MAY ALSO EXCEED 35 KTS...BUT THE HIGH STABILITY OVER THE RELATIVELY COOL LAKE WATERS WILL PREVENT THESE STRONGER WINDS FROM MIXING TO THE SURFACE. LOOK FOR LIGHTER WINDS UNDER 20 KTS ON FRI/SAT WITH A RELATIVELY WEAK PRES GRADIENT ASSOCIATED WITH HIGH BUILDING INTO THE REGION FOLLOWING A COLD FRONTAL PASSAGE ON FRI. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...JLB SHORT TERM...JLB LONG TERM...TITUS AVIATION...KC MARINE...JLB
AREA FORECAST DISCUSSION
NWS BILLINGS MT
924 PM MDT WED MAY 23 2012 .SHORT TERM...VALID FOR THU AND FRI... DIURNALLY-DRIVEN SHOWER ACTIVITY IS WINDING DOWN AS OF 03 UTC WITH THE ONSET OF COOLING IN THE BOUNDARY LAYER. LOW POPS REMAIN ACROSS THE PLAINS UNTIL 06 UTC THOUGH BECAUSE RESIDUAL CONVECTIVE SHOWERS COULD PERSIST FOR A WHILE AFTER SUNSET IN CYCLONIC FLOW ALOFT. THE 00 UTC HRRR SEEMS TOO AGGRESSIVE WITH ITS SHOWER COVERAGE AFTER 06 UTC THOUGH GIVEN RADAR TRENDS...SO WE STAYED THE COURSE WITH A DRY FORECAST FOR MOST OF THE PLAINS OVERNIGHT. NOTE...HOWEVER...THAT A MODEST AREA OF 500-300 HPA Q-VECTOR CONVERGENCE ACROSS SOUTHERN MT AND NORTHERN WY AS SHOWN BY THE 00 UTC NAM AND 18 UTC GFS IS CAUSE FOR LINGERING POPS ALL NIGHT IN THOSE AREAS. THAT FORCING COULD BE PART OF THE REASON FOR THE PRECIPITATION AROUND SHERIDAN ALREADY. OUR GOING FORECAST FOR TONIGHT HANDLES MOST OF THESE IDEAS WELL... SO ONLY MINOR CHANGES WERE REQUIRED. THE FOCUS DURING THE NEXT FEW DAYS WILL CERTAINLY BE ON THE POTENTIAL STORM...WHICH SHOULD BRING SIGNIFICANT PRECIPITATION TO THE AREA. THE 18 UTC GFS AND NAM FROM 00 UTC STILL BOTH SUPPORT THIS NOTION...AND THE WINTER STORM WATCH THAT STARTS THU EVENING FOR THE MOUNTAINS AND FOOTHILLS OVER SOUTH CENTRAL MT LOOKS ON TRACK. SCHULTZ .LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED... MADE A FEW CHANGES TO THE EXTENDED PERIOD TODAY...MAINLY WITH REGARD TO TEMPS. MODELS REMAIN IN SOMEWHAT POOR AGREEMENT ON SPECIFICS OF SYSTEM TRACKING THROUGH THE REGION AND WHAT FOLLOWS. HAVE GENERALLY MAINTAINED INHERITED POPS...WITH NOD TOWARD WARM AIR INTO THE EAST SATURDAY. SATURDAY MORNING STILL LOOKS RELATIVELY ACTIVE AS UPPER LOW PROCEEDS NORTH AND EASTWARD...BUT MODELS QUICKLY BEGIN TO DIVERGE. THE GFS MOVES THE LOW MUCH MORE QUICKLY EASTWARD INTO NORTHWESTERN ND BY SUNDAY NIGHT...MEANWHILE THE EC TAKES MORE NORTHERLY TACK TO START...MOVING INTO NORTH CENTRAL MONTANA IN THE SAME TIME FRAME. THE LOW DOES NOT REACH NORTHWESTERN ND UNTIL MONDAY AFTERNOON. DUE TO MORE WESTERLY LOCATION OF THE LOW...IT ALSO APPEARS THAT SOME WARMER AIR WILL BE DRAWN UP INTO EASTERN ZONES. EXACT EXTENT OF WARM AIR INTRUSION IS STILL UNCERTAIN...BUT HAVE RAISED HIGHS SLIGHTLY IN THE EAST. THIS AIR ALSO LOOKS A BIT DRIER...SO HAVE TAPERED POPS OFF A BIT IN THE EAST FOR SATURDAY. THE UPPER LOW TRANSITIONS OUT OF THE REGION THROUGH SUNDAY...TIMING AND TRACK ARE AGAIN ISSUES. AS LOW LIFTS OUT OF THE REGION WE SHOULD GET ANOTHER SHOT OF COLD AIR...AND SOME WRAP AROUND PRECIP...SO HAVE KEPT GOING POPS IN PLACE. EITHER WAY...THE LOCATION AND MOVEMENT...OR LACK THEREOF...OF THE UPPER LEVEL HIGH PRESSURE RIDGE OVER THE SOUTHEASTERN CONUS WILL DECIDE MOTION AND TIMING OF THE UPPER LEVEL LOW. MODELS HAVE COME BACK INTO SOME DEGREE OF AGREEMENT MONDAY...AS RIDGING REDEVELOPS... WITH DRY NORTHWEST FLOW OVER THE FORECAST AREA. HAVE KEPT SLIGHT POPS IN PLACE AT THIS TIME...BASED ON POTENTIAL AIRMASS TYPE SHOWERS...BUT SHOULD GENERALLY SEE DRYING CONDITIONS AND START TO WARMING TREND. NEXT SHORTWAVE TROF SWINGS ACROSS THE AREA TUESDAY...BRINGING SOME POTENTIAL FOR MORE SHOWER ACTIVITY. DUE TO TIMING OF THE WAVE...THIS WILL LIMIT WARMUP IN WESTERN ZONES...FROM KBIL WEST...BUT EASTERN AREAS SHOULD STILL SEE TEMPS APPROACHING 70. RIDGING QUICKLY BEGINS BUILDING BACK INTO THE REGION OVERNIGHT TUESDAY...RESULTING IN MUCH WARMER TEMPS. HAVE RAISED HIGHS SIGNIFICANTLY FOR WEDNESDAY. AAG && .AVIATION... WIDELY SCATTERED SHOWERS WILL OCCUR OVER THE REGION THROUGH 06Z... WITH SCATTERED SHOWERS OVER THE KSHR AREA. LOCALIZED MVFR CONDITIONS WILL BE POSSIBLE IN ANY HEAVIER SHOWERS. VFR CONDITIONS WILL PREVAIL AFTER 06Z. HOWEVER...SCATTERED SHOWERS WILL CONTINUE AROUND KSHR WITH POSSIBLE MVFR CONDITIONS. EXPECT AREAS OF MOUNTAIN OBSCURATION THROUGH THE NIGHT. CHANCES FOR SHOWERS WILL INCREASE OVER THE AREA ON THU. A FEW AFTERNOON THUNDERSTORMS WILL BE POSSIBLE AS WELL. LOCALIZED MVFR CONDITIONS WILL BE POSSIBLE WITH THE PRECIPITATION. MOUNTAIN OBSCURATION WILL INCREASE THROUGH THE DAY. ARTHUR && .PRELIMINARY POINT TEMP/POPS... THU FRI SAT SUN MON TUE WED ----------------------------------------------------------- BIL 042/058 038/049 039/050 037/052 037/063 044/062 044/069 24/T 36/W 87/R 65/W 22/T 22/W 32/W LVM 034/053 032/042 032/046 030/050 033/059 036/059 036/071 34/T 68/W 87/R 75/W 23/T 33/W 32/W HDN 041/060 037/054 044/061 037/054 037/065 044/063 044/072 24/T 36/W 75/R 64/W 32/T 22/W 32/W MLS 044/061 037/057 044/062 040/056 040/062 043/064 044/070 24/T 24/W 75/R 65/W 22/T 23/W 32/W 4BQ 042/060 037/057 046/067 039/061 040/064 043/068 044/069 23/T 24/W 65/R 53/W 22/T 22/W 32/W BHK 040/062 034/057 045/057 040/061 039/061 041/065 045/065 24/T 23/W 75/R 54/W 22/T 23/W 33/W SHR 038/056 035/049 039/064 036/058 035/062 039/067 040/069 43/T 36/T 65/R 64/W 22/T 22/W 32/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...WINTER STORM WATCH IN EFFECT FROM THURSDAY EVENING THROUGH LATE SATURDAY NIGHT FOR ZONES 56-66>68. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
338 AM MDT TUE MAY 22 2012 .SHORT TERM...VALID FOR TDY AND WED... 120KT H3 JET CURRENTLY NOSING THROUGH OR INTO SOUTHERN ID...WITH A LARGE AREA OF SHOWERS AFFECTING WESTERN INTO NORTH CENTRAL MONTANA TONIGHT. PV MAX APPROACHING WEST YELLOWSTONE IS ENHANCING THE SHOWERS IN OUR WEST EARLY THIS MORNING...AND PER THIS TREND AND LATEST RUC EXPECT A GOOD CHANCE OF SHOWERS ACROSS OUR WEST AND NORTHWEST PARTS THROUGH AROUND 13Z. SCATTERED SHOWERS SHOULD PUSH THRU THE BILLINGS AREA BETWEEN 10-13Z. HAVE MADE SOME ADJUSTMENTS TO THE 6-12Z POP GRID TO COVER THIS ACTIVITY...WHICH IS PUSHING A BIT MORE AGGRESSIVELY TO THE EAST SOONER THAN PREVIOUSLY THOUGHT. NEXT SHORTWAVE EMBEDDED IN THE QUICKENING PACIFIC FLOW IS STILL OFF THE COAST...AND WILL MOVE INLAND AND AFFECT OUR AREA LATER TODAY AND TONIGHT. FRONTOGENESIS WILL INCREASE BEHIND THE CURRENT ENERGY AND AHEAD OF THIS NEXT WAVE...IN AN AREA OF GOOD MOISTURE TRANSPORT. FURTHERMORE...THERE IS AN AREA OF WEAK PRESSURE FALLS IN IDAHO ASSOCIATED WITH THE JET STREAK...AND THIS MAY REDUCE/LAG THE DOWNSLOPING WINDS EXPECTED WITH THE COLD ADVECTION SET TO OCCUR TODAY. SO...EXPECT MORE SHOWERS TO DEVELOP TO OUR WEST THIS MORNING AND SPREAD INTO OUR AREA FROM LATE MORNING INTO THE EVENING...WITH A GRADUAL SAGGING TO THE SOUTH AS STRONGER FRONTOGENESIS AND JET DIVERGENCE DOES THE SAME. HAVE RAISED POPS A BIT MORE OVER OUR MOUNTAINS PER THE FAVORABLE OROGRAPHIC FLOW...MOISTURE AND INSTABILITY. 700MB TEMPS WILL FALL TO NEAR -4C TONIGHT...THUS EXPECT SOME SNOW ACCUMULATION OVER THE WEST SLOPES. CYCLONIC FLOW WITH UPPER LEVEL TROFFING AND RELATIVELY COLD TEMPS ALOFT...AND ADDITIONAL SHORTWAVE ENERGY EMBEDDED IN THE PACIFIC FLOW...WILL KEEP SHOWERY WEATHER GOING THROUGH WEDNESDAY AND WEDNESDAY NIGHT. LOW LEVEL DOWNSLOPE WINDS WILL LIMIT OUR PCPN COVERAGE TO SCATTERED ACROSS THE LOWER ELEVATIONS...GREATEST WITH DAYTIME HEATING ON WEDNESDAY...BUT OUR WEST SLOPES WILL CONTINUE TO FAVORED WITH A MIX OF RAIN AND SNOW SHOWERS. HAVE RAISED POPS OVER OUR WESTERN HIGH TERRAIN AND GIVEN ELEVATIONS ABOVE 7KFT A LITTLE SNOW ACCUMULATION EACH PERIOD. AT THE VERY LEAST...THE ONSET OF THIS MUCH COOLER PATTERN WILL STOP WHAT HAS BEEN AN EARLY HIGH ELEVATION SNOW MELT FOR A FEW DAYS. AS FOR TEMPERATURES...HIGHS TRICKY TODAY WITH MIXING/WARMING EARLY ON BECOMING OFFSET BY COLD ADVECTION WHICH WILL INCREASE BY LATE MORNING AND INTO THE AFTERNOON. EXPECT TEMPS TO DROP INTO THE 50S WITH THE SHOWER ACTIVITY. COOL POST FRONTAL AIRMASS WILL BE IN PLACE FOR WEDNESDAY. WITH WEST WINDS AND GOOD MIXING WE SHOULD STILL GET INTO THE UPPER 50S TO MID 60S ACROSS THE PLAINS...THE BEGINNING OF AN EXTENDED PERIOD OF BELOW NORMAL TEMPERATURE DAYS. JKL .LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON... EXTENDED FORECAST THROUGH THE HOLIDAY WEEKEND CONTINUES TO LOOK UNSEASONABLY COOL AND WET. MODEL AGREEMENT HAS TAKEN A HIT WITH THE LATEST RUNS AS THE GFS HAS TRENDED LESS AMPLIFIED DESPITE THE PRESENCE OF A VERY STRONG DOWNSTREAM RIDGE COMPARED TO OTHER MODELS WHICH REMAIN SIMILAR TO LAST NIGHTS AND MONDAY MORNINGS RUNS. THURSDAY...COLDER LOW LEVEL AIR BUILDS IN FROM CANADA WITH SOME SEMBLANCE OF UPSLOPE FLOW AND FRONTOGENESIS HELPING TO GENERATE SHOWERS ACROSS THE AREA. TEMPERATURES LOOK QUITE COOL WITH FORECAST HIGHS IN THE 50S...THOUGH THIS MAY BE TOO WARM GIVEN COLD ADVECTION AND PLENTY OF CLOUDS/PRECIPITATION. FLOW ALOFT BEGINS TO BACK TO THE SOUTHWEST LATE IN THE DAY WHICH WILL ENHANCE MID LEVEL OVER RUNNING KEEPING PRECIPITATION GOING INTO THE NIGHT WITH THE HEAVIEST ACCUMULATIONS LIKELY OVER SOUTHERN ZONES. FRIDAY THROUGH SUNDAY...TRACK AND TIMING OF UPPER LOW CONTINUE TO BE PROBLEMATIC WITH OPERATIONAL MODELS AND ENSEMBLE MEAN SOLUTIONS CHANGING RUN TO RUN. THE ECMWF LOOKS LIKE THE MOST STABLE SOLUTION AT THIS POINT AND ITS AMPLIFIED SOLUTION IS SUPPORTED BY STRONG RIDGING DOWNSTREAM OVER THE EASTERN US. 06Z NAM HAS TRENDED TOWARD THE 00Z ECMWF THIS MORNING AS WELL WITH ADDITIONAL SUPPORT FROM THE CANADIAN SOLUTIONS. THE GFS WENT MUCH LESS AMPLIFIED WITH THE UPPER LOW AND BLEEDS ENERGY OUT OF THE SYSTEM ACROSS WYOMING KEEPING HEAVIEST PRECIPITATION TO THE SOUTH OF THE AREA...THOUGH STILL SUPPORTING HIGH POPS JUST LESS QPF FOR FRIDAY AND SATURDAY. GENERALLY PREFER A MORE AMPLIFIED SOLUTION AS LONG AS THE DOWNSTREAM RIDGING REMAINS IN PLACE THUS DISCOUNTING THE GFS AT THIS TIME AND LEANING TOWARD AN ECMWF/ENSEMBLE MEAN SOLUTION. THIS SOLUTION PRODUCES A DEEP SOUTHERLY DIFFLUENT FLOW OVER THE AREA FRIDAY INTO SATURDAY AS THE UPPER LOW MOVES FROM CENTRAL CALIFORNIA INTO CENTRAL MONTANA. A SURFACE LOW DEVELOPS OVER NORTHEAST WYOMING ALLOWING STRONG ISENTROPIC LIFT IN THE LOWER LEVELS TO DEVELOP OVER MOST OF THE AREA SUPPORTING 1 TO 2 INCH TYPE PRECIPITATION AMOUNTS ACROSS THE AREA. EASTERLY SURFACE GRADIENT WILL ALSO SUPPORT UPSLOPE INTO AREA MOUNTAINS AND FOOTHILLS WHICH COMBINED WITH DIVERGENCE ALOFT WILL ENHANCE PRECIPITATION NEAR THE MOUNTAINS. AS A RESULT HAVE LIKELY OR BETTER POPS IN THE MOUNTAINS WITH HIGH CHANCE TO LIKELY POPS FOR THE LOWER ELEVATIONS. CURRENTLY HAVE TEMPERATURES FORECAST IN THE 50S ACROSS MOST OF THE AREA FRIDAY AND SATURDAY...BUT TEND TO THINK THIS WILL BE TOO WARM SHOULD THE ECMWF SOLUTION VERIFY ESPECIALLY SATURDAY. WITH UPPER LOW AND PLENTY OF PRECIPITATION ON SATURDAY HIGHS COULD STAY IN THE LOW TO MID 40S...WITH 30S IN THE FOOTHILLS. SNOW...FREEZING LEVELS WILL BE QUITE LOW FRIDAY MORNING SUPPORTING A MIX OF RAIN AND SNOW FOR WESTERN FOOTHILLS LOCATIONS. AS THE UPPER LOW MOVES INTO THE AREA FRIDAY NIGHT EXPECT ADDITIONAL LOWERING OF FREEZING LEVELS WITH THE POTENTIAL FOR HEAVY SNOW OVER AREA MOUNTAINS AS 700MB TEMPERATURES DROP TO AROUND -10C. THIS WOULD BRING THE CHANCE FOR ACCUMULATING SNOW IN THE RED LODGE...NYE AND POSSIBLY LIVINGSTON AREAS FRIDAY NIGHT/SATURDAY MORNING...ALONG WITH HEAVY SNOW ALONG THE BEARTOOTH PASS. WENT AHEAD AND BUMPED QPF AND SNOW ACCUMULATIONS UP FOR THESE PERIODS BUT AMOUNTS ARE DEPENDENT ON A FAVORABLE TRACK TO THE UPPER LOW AND COULD BE OVERDONE IF THE LOW TRACK IS FURTHER WEST OR SOUTH. ANYONE PLANNING TRAVEL TO THE HIGH COUNTRY...INCLUDING ALONG THE BEARTOOTH HIGHWAY...SHOULD REMAIN ALERT TO THE LATEST FORECASTS AND SHOULD PROBABLY PLAN ON WINTER DRIVING CONDITIONS. SUNDAY...MOST OF THE MODELS INDICATING DOWNSLOPE WINDS WILL SCOUR OUT PRECIPITATION SUNDAY AFTERNOON...THUS HAVE TRENDED POPS DOWN SUNDAY INTO MONDAY. HOWEVER THERE IS A CHANCE THAT A MORE AMPLIFIED SYSTEM WILL MOVE SLOWER LINGERING PRECIPITATION INTO MONDAY...SO HAVE NOT GONE DRY. NORTHWEST WINDS WILL BECOME GUSTY SUNDAY AFTERNOON INTO SUNDAY NIGHT WHICH WILL HELP HOLD TEMPERATURES WARMER THAN SATURDAY NIGHT. MONDAY THROUGH WEDNESDAY...ECMWF INDICATING ZONAL FLOW WHILE GFS DRIVES ANOTHER PACIFIC SYSTEM INTO THE AREA. KEEPING SOME LOW POPS IN THE FORECAST ALONG WITH WARMER TEMPERATURES FOR NOW. CHAMBERS && .AVIATION... UPPER LEVEL STORM SYSTEM IS MOVING INTO WESTERN AREAS THIS MORNING WITH SCATTERED RAIN SHOWERS. LOCAL MVFR CONDITIONS ARE EXPECTED FROM KBIL WEST TO KLVM THROUGH 18Z. THIS AFTERNOON MVFR OR LOWER CONDITIONS WILL BECOME PREDOMINANT WEST OF A ROUNDUP TO SHERIDAN WYOMING LINE...WITH SCATTERED SHOWERS AND THUNDERSTORMS TO THE EAST RESULTING IN LOCAL MVFR CONDITIONS FOR KMLS. OCCASIONAL MOUNTAIN OBSCURATION THIS MORNING WILL BECOME PREDOMINANT THIS AFTERNOON AND CONTINUE THROUGH TONIGHT. CHAMBERS && .PRELIMINARY POINT TEMP/POPS... TDY WED THU FRI SAT SUN MON ------------------------------------------------------- BIL 071 045/062 042/055 040/053 040/054 040/065 044/068 7/T 44/T 36/T 55/T 66/T 53/T 22/T LVM 062 037/055 034/052 033/049 034/052 032/061 038/066 7/T 45/T 36/T 56/T 66/T 73/T 22/T HDN 075 044/064 042/056 040/056 041/059 041/067 044/069 7/T 54/T 46/T 55/T 66/T 52/T 22/T MLS 077 047/067 044/057 042/056 043/059 043/066 045/069 6/T 42/W 34/T 34/T 55/T 53/T 22/T 4BQ 080 047/064 043/056 040/055 044/062 042/067 044/071 5/T 63/T 34/T 44/T 75/T 53/T 22/T BHK 081 045/064 041/060 040/053 044/057 043/064 044/069 5/T 42/W 24/T 34/T 55/T 53/T 22/T SHR 077 042/060 039/054 037/053 039/060 039/063 040/067 4/T 64/T 45/T 45/T 66/T 53/T 22/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS GLASGOW MT
1027 PM MDT MON MAY 21 2012 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH WEDNESDAY... 10 PM UPDATE...AREAS OF SHOWERS CONTINUE TO MOVE INTO THE WESTERN AREAS AND WEAKEN AS THEY PUSH EAST. KEPT HIGH POPS FOR THE WEST AND SLIGHT OR ISOLATED POPS IN THE EAST. DROPPED THUNDER FOR THE NIGHTTIME HOURS. MODELS SHOW THAT THUNDER DEVELOPING MID DAY OVER THE FORECAST AREA AND SPREADING EAST DURING THE EARLY AFTERNOON...AND BECOMING SEVERE IN NORTH DAKOTA. ANY SLOWING UP OF THE FRONT COULD BRING A SHOT OF SEVERE THUNDER TO PLENTYWOOD- SIDNEY-WIBAUX AREAS IN THE AFTERNOON. BUFR NAM SOUNDINGS HAVE THE INVERTED V... PW/S NEARING 1.00... AND A GOOD TURN IN THE WIND FIELD FROM SFC TO 850 MB. WILL NOT UPDATE DAY TWO OF THE FORECAST...BUT COULD BE BRIEFLY A CONCERN IN THE EARLY AFTERNOON FOR THE FAR EASTERN ZONES. PROTON 8 PM UPDATE...AN ARC OF SHOWERS WITH A FLASH OR TWO OF THUNDER CONTINUE TO PUSH EAST ACROSS THE CMR AND GARFIELD COUNTY THIS EVENING. THE ARC OF SHOWERS/STORMS HAS PRODUCED 30 TO 50 MPH WIND GUSTS AS IT PASSES OVER OBSERVATION SITES. THE LATEST HRRR MODEL PUSHES THIS ARC THROUGH AND DIMINISHES IT THROUGH 10 PM. WILL HAVE TO WATCH THE AREA OF SHOWERS TO THE EAST OF GREAT FALLS... THE HRRR BRINGS THAT THROUGH THE WESTERN CMR AND UP FORT PECK LAKE THROUGH MIDNIGHT. MAY HAVE TO UPDATE AT 10 PM TO BETTER DEFINE OVERNIGHT POPS AND QPF. PROTON 6 PM UPDATE...AN AREA OF THUNDERSTORMS HELD TOGETHER OVER CENTRAL MONTANA AND IS MOVING INTO THE WESTERN ZONES. UPDATED THE FORECAST TO ADD GUSTY WINDS SINCE UPSTREAM OBSERVATIONS HAVE SOME GUSTS TO 30 MPH. INCREASED POP COVERAGE FOR THE CMR AND THE WEST SIDE OF FORT PECK LAKE WITH THE HRRR MODEL HITTING THIS AREA HARDER WITH RAINFALL THIS EVENING. PROTON UPPER TROF OFF THE PACIFIC NORTHWEST EXPECTED TO TRANSITION INTO MONTANA DURING THE SHORT TERM. SOUTHWEST FLOW ALOFT ALREADY PUSHING INCREASED MOISTURE INTO THE WESTERN PART OF THE STATE AND A FEW HIGH BASED THUNDERSTORMS ARE MOVING ACROSS CENTRAL MONTANA THIS AFTERNOON. AIRMASS OVER EASTERN MONTANA STILL QUITE DRY AND AFFECTED BY PROXIMITY OF RIDGE AXIS BUT JET STREAK PUSHING ACROSS CENTRAL MONTANA INTO SOUTHERN SASKATCHEWAN OVERNIGHT WILL HELP SPREAD THUNDERSTORMS OVER THE NORTHWEST ZONES. JET ALSO PUSHES COLD FRONT ACROSS THE STATE OVERNIGHT AND WITH COLD AIR ADVECTION ...TIGHTENING PRESSURE GRADIENT AND DOWNSLOPE FLOW WITH JET EXPECT WINDS TO INCREASE ACROSS THE REGION ON TUESDAY. SHOULD BE STRONG ENOUGH FOR LAKE WIND ADVISORY BY MIDDAY...EXTENDING INTO THE EVENING HOURS IF NOT THROUGH THE NIGHT. STRONG WESTERLIES AND CAA BEHIND THE FRONT WILL RESULT IN SOME INHIBITION OF SHOWERS FOR TUESDAY MORNING. ANOTHER JET STREAK PUSHES ACROSS NORTHERN WYOMING IN THE AFTERNOON...WHICH COULD HELP DEVELOP CONVECTION OFF THE HIGHER TERRAIN IN SOUTHWEST MONTANA AND PUSH IT INTO THE PLAINS. BY WEDNESDAY THE BETTER LIFT MOVES EAST AS THE UPPER TROF SLIDES INTO MONTANA. COLD AIR ALOFT COULD RESULT IN ENOUGH INSTABILITY FOR A FEW SHOWERS BUT OVERALL TREND WILL BE DRY AND COOL. LOW LEVELS MIX ENOUGH THAT ANOTHER LAKE WIND ADVISORY MAY BE NEEDED. EBERT .LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY... MADE SOME ADJUSTMENTS TO THE LONG TERM FORECAST PERIOD. A BROAD UPPER LEVEL TROUGH WILL DOMINATE THE WEATHER PATTERN OVER THE ROCKIES...INTER-MOUNTAIN WEST...AND NORTHERN HIGH PLAINS THROUGH MOST OF THE EXTENDED PERIOD. LOOKS LIKE IT UNFOLD IN TWO PHASES. FIRST...THE LONG AND BROAD UN-AMPLIFIED TROUGH WILL DROP THROUGH THE NORTHERN ROCKIES AND NORTHERN HIGH PLAINS FROM WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. FROM THURSDAY NIGHT ONWARD...AN UPSTREAM UPPER LEVEL LOW CENTER LOBE BECOMES THE STAR OF THE SHOW AS IT QUICKLY DEEPENS AND DIGS DOWN OVER THE CASCADE MOUNTAIN RANGE...BOTTOMING OUT OVER LAS VEGAS...THEN QUICKLY CHANGING COURSE AND HEADING NORTHEAST THROUGH SUNDAY...EVENTUALLY MOVING DIRECTLY OVER OUR CWA. MODELS ARE IN MODERATELY GOOD AGREEMENT WITH THIS GENERAL WEATHER PATTERN...BUT ANY MORE DETAILS GET KIND OF MUDDLED. ESPECIALLY WITH THE NORTHWARD PROGRESSION OF THIS LATE UPPER LOW THROUGH THE WEEKEND. THE GFS DIFFUSES AND OPENS UP THIS LOW CENTER QUITE QUICKLY...BUT THE EC HOLDS ONTO IT AND EVEN DEEPENS IT OVER OUR CWA WHICH WOULD RESULT IN MUCH COLDER TEMPERATURES THAN WE HAVE CURRENTLY FORECASTED. TRIED TO SHOW AN EXTENDED MODEL BLEND...BUT DID NOT GIVE EQUAL WEIGHT TO THE EXTREME EC OUTLIER AND WOULD ADVISE DOING SO UNTIL EXTENDED MODELS SHOW BETTER AGREEMENT. OVERALL...EXPECT ALTERNATING PERIODS OF RAIN SHOWERS AND DRY SLOTS WITH GENERALLY COOLER TEMPERATURES AS THIS LARGE UPPER TROUGH SYSTEM SPREADS ACROSS MOST OF THIS PORTION OF THE CONTINENT. BMICKELSON PREVIOUS LONG TERM DISCUSSION...MODELS TAKE ONE UPPER TROUGH TO THE EAST THURSDAY AND THURSDAY NIGHT WHILE DIGGING ANOTHER OVER THE PACIFIC NORTHWEST. WHILE THE BULK OF THE MOISTURE WITH THURSDAY`S TROUGH IS EXPECTED TO BE TO THE EAST...THERE WILL BE ENOUGH LINGERING MOISTURE AND INSTABILITY TO WARRANT A CHANCE OF SHOWERS. ON FRIDAY...THE FORECAST WILL BE BETWEEN SYSTEMS IN A SOUTHWEST FLOW ALOFT AS A CLOSED LOW DEVELOPS IN CALIFORNIA IN THE WEST COAST UPPER TROUGH. MODELS DIFFER BETWEEN A DRY SW FLOW (GFS) AND MOIST SW FLOW (ECMWF) ALOFT. WILL MAINTAIN EITHER A CHANCE OR SLIGHT CHANCE OF SHOWERS. MODELS GRADUALLY LIFT THIS LOW NORTH OVER THE WEEKEND AND BRING IT ACROSS MONTANA ON SUNDAY. IF THIS FORECAST HOLDS TRUE...IT COULD BE A VERY WET WEEKEND ACROSS THE REGION. WILL MAINTAIN A CHANCE OF SHOWERS FOR NOW UNTIL BETTER RUN TO RUN AGREEMENT IS MAINTAINED. THE LOW LIFTS NORTH NEXT MONDAY DIMINISHING THE CHANCE OF SHOWERS. FORRESTER && .AVIATION... AN APPROACHING PACIFIC LOW PRESSURE SYSTEM WILL BRING INCREASED CLOUDINESS AND RAIN SHOWERS TO NORTHEAST MONTANA TOWARD THE END OF THIS TAF PERIOD. VFR CONDITIONS ARE EXPECTED TO PREVAIL WITH ONE BRIEF EXCEPTION...KGGW MAY SEE MVFR CONDITIONS WITH A BRIEF RAIN SHOWER TONIGHT AND AGAIN BY MID DAY TUESDAY. A COLD FRONT WILL PUSH RAIN SHOWERS AND POSSIBLY A FEW THUNDERSTORMS THROUGH THE ENTIRE REGION. WINDS WILL SHIFT AROUND TO COME FROM THE NORTHWEST AND WEST DURING THE LATE MORNING HOURS ON TUESDAY...THEN INCREASE INTO THE 25G35KT RANGE BY MID DAY. OVERALL...EXPECT INCREASED CROSSWIND CONCERNS FOR NORTH TO SOUTH ORIENTED RUNWAYS DURING THE MID DAY AND AFTERNOON HOURS ON TUESDAY WITH BRIEF MODERATE RAIN SHOWERS. BMICKELSON && .GLASGOW WATCHES/WARNINGS/ADVISORIES... LAKE WIND ADVISORY FROM 10 AM TO 9 PM MDT TUESDAY FOR FORT PECK LAKE. && $$ WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1104 PM CDT WED MAY 23 2012 .UPDATE...KUEX INDICATES CONVECTION SPREADING IN AERIAL COVERAGE ACROSS THE NORTHWESTERN ONE-THIRD OF THE CWA. SHORT TERM GUIDANCE CONTINUES TO SUGGEST THIS A TREND WHICH WILL CONTINUE. DEEP LAYER MUCAPE VALUES NEAR 1000J/KG AND DEEP LAYER BULK SHEAR NEAR 50KTS WILL CONTINUE TO PROMOTE A THREAT OF LARGE HAIL. A NEW SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED WHICH COVERS THE ENTIRE CWA THROUGH 10Z. FORECAST HAS BEEN UPDATED TO INCLUDE THIS NEW SEVERE THUNDERSTORM WATCH. && .PREV DISCUSSION... /ISSUED 949 PM CDT WED MAY 23 2012/ UPDATE...EVENING UPPER AIR ANALYSIS INDICATES TROUGHING OVER THE WESTERN CONUS WITH A RIDGE OVER THE EAST. MID AND UPPER LEVEL JET ENERGY EXTENDS FROM THE WEST-CENTRAL CONUS...SOUTHEAST INTO THE MID ROCKY MOUNTAIN RANGE AND THEN NORTHEAST ACROSS THE CENTRAL PLAINS. A ~100KT UPPER LEVEL JET STREAK AND A ~70KT MID LEVEL JET STREAK IS NOTED ACROSS THE WEST-CENTRAL CONUS AND BEGINNING TO PUSH INTO THE CENTRAL PLAINS. WATER VAPOR IMAGERY SHOWS A MID LEVEL SHORT WAVE APPROACHING THE MID ROCKY MOUNTAIN RANGE. AT THE SURFACE A COLD FRONT EXTENDS FROM NEAR KOMA...TO NEAR KCNK...TO NEAR KDDC. LOW LEVEL FLOW IS FROM THE THE NORTHEAST ACROSS MUCH OF OUR CWA AS A RESULT...ALTHOUGH LOCATIONS FROM THAYER COUNTY TO MITCHELL COUNTY...STILL AHEAD OF THE LOW LEVEL BAROCLINIC ZONE...REMAIN FROM THE SOUTHEAST. KUEX SHOWS A THIN LINE OF CONVECTION...ALONG THE LOW LEVEL BAROCLINIC ZONE...EXTENDING FROM THAYER COUNTY TO MITCHELL COUNTY...BUT ADDITIONAL CONVECTION IS NOT FIRING FARTHER NORTHWEST ACROSS MUCH OF THE REST OF THE CWA. SHORT TERM GUIDANCE SUGGESTS SURFACE-BASED CONVECTION WILL REMAIN POSSIBLE ALONG THE LOW LEVEL BAROCLINIC ZONE THROUGH 04Z OR SO...HOWEVER THIS ACTIVITY SHOULD DIMINISH THEREAFTER AS DIABATIC HEATING IS COMPLETELY LOST AND REMNANT FORCING ALONG THE BAROCLINIC ZONE REMAINS FAIRLY WEAK. THE INDIRECT THERMAL CIRCULATION WITHIN THE LEFT-FRONT QUAD OF THE APPROACHING MID LEVEL JET STREAK...ALONG WITH CONTINUALLY INCREASING OMEGA AHEAD OF THE MID LEVEL SHORT WAVE...WILL CONTINUE TO PROMOTE PRECIPITATION ACROSS MUCH OF THE CWA THROUGH THE OVERNIGHT HOURS. AT THIS TIME IT APPEARS THE BULK OF THE FORCING OVERNIGHT WILL BE RELEGATED TO THE NORTHERN HALF OF THE CWA WHICH IS WHERE MOST OF THE PRECIPITATION WILL BE REALIZED. SPC MESO-ANALYSIS INDICATES DEEP LAYER MUCAPE VALUES OF AROUND 1000J/KG CURRENTLY IN EXISTENCE ACROSS MUCH OF THE CWA...WITH DEEP LAYER SHEAR OF AROUND 60KTS. THE COMBINATION OF MODERATE INSTABILITY AND VERY STRONG DEEP LAYER SHEAR WILL CONTINUE TO PROMOTE A THREAT OF LARGE HAIL ACROSS MUCH OF THE CWA THROUGH EARLY MORNING THURSDAY. WENT AHEAD AND UPDATED THE FORECAST WITH SLIGHT CHANGES MADE TO HOURLY GIRDS TO BETTER REFLECT CURRENT TRENDS...ESPECIALLY REGARDING CLOUD COVER. CURRENT POPS ACROSS NORTHERN PORTIONS OF THE CWA LOOK RIGHT ON FOR TONIGHT AND THUS RAIN CHANCES WERE LEFT AS IS. PREV DISCUSSION... /ISSUED 637 PM CDT WED MAY 23 2012/ AVIATION...00Z KGRI TAF. THUNDERSTORM DEVELOPMENT COULD OCCUR ALONG A SURFACE COLD FRONT CONTINUING TO MOVE TO THE SOUTHEAST. THIS SURFACE CONVECTION SHOULD REMAIN SOUTHEAST OF THE TERMINAL. LATER ON TOWARD LATE EVENING...A LOW-LEVEL JET WILL ENCOURAGE SEVERE THUNDERSTORMS TO DEVELOP AND LINGER INTO THE EARLY OVERNIGHT HOURS. WIND MAY BE A BIT GUSTY FOR THURSDAY...WITH SOME SMALL CHANCES OF THUNDERSTORMS. HOWEVER...CHANCES OF PRECIPITATION ON THURSDAY ARE SMALL ENOUGH TO LEAVE OUT OF THE FORECAST FOR NOW. PREV DISCUSSION... /ISSUED 419 PM CDT WED MAY 23 2012/ UPDATE...SENT AN UPDATE TO THE FORECAST TO INCLUDE SEVERE THUNDERSTORM WATCH 293 FOR PORTIONS OF THE FORECAST AREA THROUGH 11 PM CDT. THE GREATEST POTENTIAL FOR ANY SEVERE STORMS WILL REMAIN WITH AND ALONG EITHER SIDE OF A SLOWLY PROGRESSING COLD FRONT...WITH LARGE HAIL AND DAMAGING WIND GUSTS BEING THE PRIMARY CONCERNS WITH ANY STORMS THAT DO DEVELOP. PREV DISCUSSION... /ISSUED 400 PM CDT WED MAY 23 2012/ SHORT TERM...A FAIRLY ACTIVE START TO THE FORECAST IS EXPECTED THIS EVENING AS A COLD FRONT SLOWLY MAKES ITS WAY ACROSS SOUTH CENTRAL NEBRASKA AND NORTH CENTRAL KANSAS...WITH AN ASSOCIATED MID LEVEL LOW PRESSURE SYSTEM TO THE WEST EXPECTED TO HELP BRING SOME WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY ACROSS MUCH OF THE FORECAST AREA DURING THE OVERNIGHT HOURS TONIGHT. SHORT TERM MODELS ARE IN MODERATE DISAGREEMENT WITH INITIATION OF CONVECTION ALONG A PASSING COLD FRONT...CURRENTLY DRAPED FROM NEAR NORFOLK...ACROSS GRAND ISLAND...SOUTH WESTWARD TOWARDS HOLDREGE. THIS FRONT HAS BEEN VERY SLOW TO WORK ITS WAY ACROSS THE FORECAST AREA THIS AFTERNOON...AND SO FAR HAS YET TO PRODUCE ENOUGH FORCING TO BREAK LOW LEVEL CAP. 12Z NAM AND WRF BOTH DID TRY AND INITIATE CONVECTION...BUT 18Z NAM AND LATEST HRRR BOTH HOLD OFF ANY WIDESPREAD SHOWER OR THUNDERSTORM ACTIVITY TILL FORCING FROM MID LEVEL LOW TO OUR WEST APPROACHES CENTRAL NEBRASKA AROUND MIDNIGHT. THAT BEING SAID...INGREDIENTS ARE IN PLACE...AS LATEST MESO ANALYSIS SHOWS A FINGER OF 2000+ J/KG OF CAPE ACROSS THE LOCAL AREA NEAR THE SLOWLY PROGRESSING FRONT...AND LITTLE INHIBITION AS WELL AS DEVELOPING CU FIELD IN SATELLITE. PER CONSENSUS AMONG MODELS...DID BACK OFF ON INITIATION OF CONVECTION THIS AFTERNOON...BUT INSERTED MENTION OF SEVERE STORMS AFTER 00Z...AS COMBINATION OF SHEAR AND INSTABILITY SHOULD BE SUFFICIENT FOR SOME SUPERCELLS TO DEVELOP IF INITIATION CAN BE REALIZED NEAR THE FRONT. BEHIND THE FRONT...AS THE MID LEVEL SHORTWAVE APPROACHES THE REGION...BROADER SCALE FORCING SHOULD BE AMPLE ENOUGH TO DEVELOP WIDESPREAD CONVECTION ACROSS THE LOCAL AREA BY AROUND MIDNIGHT...CONTINUING INTO THE OVERNIGHT HOURS...SO THE POTENTIAL FOR SEVERE HAIL AND STRONG WINDS REMAIN A CONCERN. THEREAFTER...THE ATMOSPHERE SHOULD BEGIN TO STABILIZE BEHIND THE DEPARTING MID LEVEL WAVE...WITH A SMALL CHANCE FOR SHOWERS AND AN ISOLATED THUNDERSTORM CONTINUING INTO THE AFTERNOON HOURS WITH NEAR TO SLIGHTLY BELOW SEASONAL TEMPERATURES EXPECTED DURING THE AFTERNOON. LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY. MAIN FORECAST CONCERNS WILL BE CHANCES FOR THUNDERSTORMS THROUGH MOST OF THE PERIOD AND TEMPERATURES. ZONAL TO SOUTHWEST FLOW GIVES WAY TO NORTHWEST FLOW. THERE ARE SEVERAL WAVES THAT MOVE THROUGH THE AREA DURING THE PERIOD. THE FIRST WAVE MOVES INTO THE AREA THURSDAY NIGHT INTO FRIDAY. THERE WILL BE A CHANCE FOR SOME THUNDERSTORMS. ON FRIDAY A SURFACE LOW DEVELOPING IN KANSAS WILL LIFT A WARM FRONT NORTH INTO THE FORECAST AREA. WITH THE FRONT MOVING THROUGH AND THE ANOTHER UPPER WAVE MOVING INTO THE AREA THERE IS A BETTER CHANCE FOR THUNDERSTORMS. SOME OF THESE STORMS COULD BE STRONG TO SEVERE. SATURDAY AND SATURDAY NIGHT THERE ARE WEAK WAVES THAT MOVES THROUGH BUT LITTLE IN THE WAY TO GET THINGS STARTED SO ANY PRECIPITATION WILL BE SPOTTY. THE NEXT CHANCE FOR SOME THUNDERSTORMS WILL BE SUNDAY INTO SUNDAY NIGHT. ANOTHER STRONGER WAVE MOVES INTO THE AREA AND A COLD FRONT MOVES THROUGH THE AREA SUNDAY AFTERNOON AND EVENING. THUNDERSTORMS WILL DEVELOP ALONG THE FRONT AS IT MOVES THROUGH. SOME OF THESE COULD BE SEVERE. MONDAY AND MONDAY NIGHT THE UPPER WAVE MOVES TO THE EAST AND A SURFACE HIGH PRESSURE MOVES INTO THE AREA...KEEPING THINGS DRY. AGAIN TUESDAY INTO TUESDAY NIGHT THERE ARE A FEW WEAK UPPER LEVEL WAVES THAT MOVE INTO THE PLAINS. MODELS HAVE SOME FAIRLY SPOTTY PRECIPITATION AROUND THE AREA WITH THESE UPPER LEVEL WAVES. THE GFS HAS MORE PRECIPITATION AROUND THAN THE ECMWF DOES. TEMPERATURES WILL BE SOMEWHAT VARIABLE THROUGH THE WEEK. WITH CLOUDS AROUND ON FRIDAY THE TEMPERATURES WILL BE A BIT COOLER...WARMING AFTER THE WARM FRONT LIFTS TO THE NORTH FOR SATURDAY AND SUNDAY THEN COOLING AGAIN AS THE COOL FRONT MOVE THROUGH MONDAY AND TUESDAY AND COOLING MORE AFTER THE FRONT MOVES THROUGH TUESDAY. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ 1105 UPDATE/949 UPDATE...BRYANT AVIATION...HEINLEIN SHORT TERM/419 UPDATE...ROSSI LONG TERM...JCB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
949 PM CDT WED MAY 23 2012 .UPDATE...EVENING UPPER AIR ANALYSIS INDICATES TROUGHING OVER THE WESTERN CONUS WITH A RIDGE OVER THE EAST. MID AND UPPER LEVEL JET ENERGY EXTENDS FROM THE WEST-CENTRAL CONUS...SOUTHEAST INTO THE MID ROCKY MOUNTAIN RANGE AND THEN NORTHEAST ACROSS THE CENTRAL PLAINS. A ~100KT UPPER LEVEL JET STREAK AND A ~70KT MID LEVEL JET STREAK IS NOTED ACROSS THE WEST-CENTRAL CONUS AND BEGINNING TO PUSH INTO THE CENTRAL PLAINS. WATER VAPOR IMAGERY SHOWS A MID LEVEL SHORT WAVE APPROACHING THE MID ROCKY MOUNTAIN RANGE. AT THE SURFACE A COLD FRONT EXTENDS FROM NEAR KOMA...TO NEAR KCNK...TO NEAR KDDC. LOW LEVEL FLOW IS FROM THE THE NORTHEAST ACROSS MUCH OF OUR CWA AS A RESULT...ALTHOUGH LOCATIONS FROM THAYER COUNTY TO MITCHELL COUNTY...STILL AHEAD OF THE LOW LEVEL BAROCLINIC ZONE...REMAIN FROM THE SOUTHEAST. KUEX SHOWS A THIN LINE OF CONVECTION...ALONG THE LOW LEVEL BAROCLINIC ZONE...EXTENDING FROM THAYER COUNTY TO MITCHELL COUNTY...BUT ADDITIONAL CONVECTION IS NOT FIRING FARTHER NORTHWEST ACROSS MUCH OF THE REST OF THE CWA. SHORT TERM GUIDANCE SUGGESTS SURFACE-BASED CONVECTION WILL REMAIN POSSIBLE ALONG THE LOW LEVEL BAROCLINIC ZONE THROUGH 04Z OR SO...HOWEVER THIS ACTIVITY SHOULD DIMINISH THEREAFTER AS DIABATIC HEATING IS COMPLETELY LOST AND REMNANT FORCING ALONG THE BAROCLINIC ZONE REMAINS FAIRLY WEAK. THE INDIRECT THERMAL CIRCULATION WITHIN THE LEFT-FRONT QUAD OF THE APPROACHING MID LEVEL JET STREAK...ALONG WITH CONTINUALLY INCREASING OMEGA AHEAD OF THE MID LEVEL SHORT WAVE...WILL CONTINUE TO PROMOTE PRECIPITATION ACROSS MUCH OF THE CWA THROUGH THE OVERNIGHT HOURS. AT THIS TIME IT APPEARS THE BULK OF THE FORCING OVERNIGHT WILL BE RELEGATED TO THE NORTHERN HALF OF THE CWA WHICH IS WHERE MOST OF THE PRECIPITATION WILL BE REALIZED. SPC MESO-ANALYSIS INDICATES DEEP LAYER MUCAPE VALUES OF AROUND 1000J/KG CURRENTLY IN EXISTENCE ACROSS MUCH OF THE CWA...WITH DEEP LAYER SHEAR OF AROUND 60KTS. THE COMBINATION OF MODERATE INSTABILITY AND VERY STRONG DEEP LAYER SHEAR WILL CONTINUE TO PROMOTE A THREAT OF LARGE HAIL ACROSS MUCH OF THE CWA THROUGH EARLY MORNING THURSDAY. WENT AHEAD AND UPDATED THE FORECAST WITH SLIGHT CHANGES MADE TO HOURLY GIRDS TO BETTER REFLECT CURRENT TRENDS...ESPECIALLY REGARDING CLOUD COVER. CURRENT POPS ACROSS NORTHERN PORTIONS OF THE CWA LOOK RIGHT ON FOR TONIGHT AND THUS RAIN CHANCES WERE LEFT AS IS. && .PREV DISCUSSION... /ISSUED 637 PM CDT WED MAY 23 2012/ AVIATION...00Z KGRI TAF. THUNDERSTORM DEVELOPMENT COULD OCCUR ALONG A SURFACE COLD FRONT CONTINUING TO MOVE TO THE SOUTHEAST. THIS SURFACE CONVECTION SHOULD REMAIN SOUTHEAST OF THE TERMINAL. LATER ON TOWARD LATE EVENING...A LOW-LEVEL JET WILL ENCOURAGE SEVERE THUNDERSTORMS TO DEVELOP AND LINGER INTO THE EARLY OVERNIGHT HOURS. WIND MAY BE A BIT GUSTY FOR THURSDAY...WITH SOME SMALL CHANCES OF THUNDERSTORMS. HOWEVER...CHANCES OF PRECIPITATION ON THURSDAY ARE SMALL ENOUGH TO LEAVE OUT OF THE FORECAST FOR NOW. PREV DISCUSSION... /ISSUED 419 PM CDT WED MAY 23 2012/ UPDATE...SENT AN UPDATE TO THE FORECAST TO INCLUDE SEVERE THUNDERSTORM WATCH 293 FOR PORTIONS OF THE FORECAST AREA THROUGH 11 PM CDT. THE GREATEST POTENTIAL FOR ANY SEVERE STORMS WILL REMAIN WITH AND ALONG EITHER SIDE OF A SLOWLY PROGRESSING COLD FRONT...WITH LARGE HAIL AND DAMAGING WIND GUSTS BEING THE PRIMARY CONCERNS WITH ANY STORMS THAT DO DEVELOP. PREV DISCUSSION... /ISSUED 400 PM CDT WED MAY 23 2012/ SHORT TERM...A FAIRLY ACTIVE START TO THE FORECAST IS EXPECTED THIS EVENING AS A COLD FRONT SLOWLY MAKES ITS WAY ACROSS SOUTH CENTRAL NEBRASKA AND NORTH CENTRAL KANSAS...WITH AN ASSOCIATED MID LEVEL LOW PRESSURE SYSTEM TO THE WEST EXPECTED TO HELP BRING SOME WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY ACROSS MUCH OF THE FORECAST AREA DURING THE OVERNIGHT HOURS TONIGHT. SHORT TERM MODELS ARE IN MODERATE DISAGREEMENT WITH INITIATION OF CONVECTION ALONG A PASSING COLD FRONT...CURRENTLY DRAPED FROM NEAR NORFOLK...ACROSS GRAND ISLAND...SOUTH WESTWARD TOWARDS HOLDREGE. THIS FRONT HAS BEEN VERY SLOW TO WORK ITS WAY ACROSS THE FORECAST AREA THIS AFTERNOON...AND SO FAR HAS YET TO PRODUCE ENOUGH FORCING TO BREAK LOW LEVEL CAP. 12Z NAM AND WRF BOTH DID TRY AND INITIATE CONVECTION...BUT 18Z NAM AND LATEST HRRR BOTH HOLD OFF ANY WIDESPREAD SHOWER OR THUNDERSTORM ACTIVITY TILL FORCING FROM MID LEVEL LOW TO OUR WEST APPROACHES CENTRAL NEBRASKA AROUND MIDNIGHT. THAT BEING SAID...INGREDIENTS ARE IN PLACE...AS LATEST MESO ANALYSIS SHOWS A FINGER OF 2000+ J/KG OF CAPE ACROSS THE LOCAL AREA NEAR THE SLOWLY PROGRESSING FRONT...AND LITTLE INHIBITION AS WELL AS DEVELOPING CU FIELD IN SATELLITE. PER CONSENSUS AMONG MODELS...DID BACK OFF ON INITIATION OF CONVECTION THIS AFTERNOON...BUT INSERTED MENTION OF SEVERE STORMS AFTER 00Z...AS COMBINATION OF SHEAR AND INSTABILITY SHOULD BE SUFFICIENT FOR SOME SUPERCELLS TO DEVELOP IF INITIATION CAN BE REALIZED NEAR THE FRONT. BEHIND THE FRONT...AS THE MID LEVEL SHORTWAVE APPROACHES THE REGION...BROADER SCALE FORCING SHOULD BE AMPLE ENOUGH TO DEVELOP WIDESPREAD CONVECTION ACROSS THE LOCAL AREA BY AROUND MIDNIGHT...CONTINUING INTO THE OVERNIGHT HOURS...SO THE POTENTIAL FOR SEVERE HAIL AND STRONG WINDS REMAIN A CONCERN. THEREAFTER...THE ATMOSPHERE SHOULD BEGIN TO STABILIZE BEHIND THE DEPARTING MID LEVEL WAVE...WITH A SMALL CHANCE FOR SHOWERS AND AN ISOLATED THUNDERSTORM CONTINUING INTO THE AFTERNOON HOURS WITH NEAR TO SLIGHTLY BELOW SEASONAL TEMPERATURES EXPECTED DURING THE AFTERNOON. LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY. MAIN FORECAST CONCERNS WILL BE CHANCES FOR THUNDERSTORMS THROUGH MOST OF THE PERIOD AND TEMPERATURES. ZONAL TO SOUTHWEST FLOW GIVES WAY TO NORTHWEST FLOW. THERE ARE SEVERAL WAVES THAT MOVE THROUGH THE AREA DURING THE PERIOD. THE FIRST WAVE MOVES INTO THE AREA THURSDAY NIGHT INTO FRIDAY. THERE WILL BE A CHANCE FOR SOME THUNDERSTORMS. ON FRIDAY A SURFACE LOW DEVELOPING IN KANSAS WILL LIFT A WARM FRONT NORTH INTO THE FORECAST AREA. WITH THE FRONT MOVING THROUGH AND THE ANOTHER UPPER WAVE MOVING INTO THE AREA THERE IS A BETTER CHANCE FOR THUNDERSTORMS. SOME OF THESE STORMS COULD BE STRONG TO SEVERE. SATURDAY AND SATURDAY NIGHT THERE ARE WEAK WAVES THAT MOVES THROUGH BUT LITTLE IN THE WAY TO GET THINGS STARTED SO ANY PRECIPITATION WILL BE SPOTTY. THE NEXT CHANCE FOR SOME THUNDERSTORMS WILL BE SUNDAY INTO SUNDAY NIGHT. ANOTHER STRONGER WAVE MOVES INTO THE AREA AND A COLD FRONT MOVES THROUGH THE AREA SUNDAY AFTERNOON AND EVENING. THUNDERSTORMS WILL DEVELOP ALONG THE FRONT AS IT MOVES THROUGH. SOME OF THESE COULD BE SEVERE. MONDAY AND MONDAY NIGHT THE UPPER WAVE MOVES TO THE EAST AND A SURFACE HIGH PRESSURE MOVES INTO THE AREA...KEEPING THINGS DRY. AGAIN TUESDAY INTO TUESDAY NIGHT THERE ARE A FEW WEAK UPPER LEVEL WAVES THAT MOVE INTO THE PLAINS. MODELS HAVE SOME FAIRLY SPOTTY PRECIPITATION AROUND THE AREA WITH THESE UPPER LEVEL WAVES. THE GFS HAS MORE PRECIPITATION AROUND THAN THE ECMWF DOES. TEMPERATURES WILL BE SOMEWHAT VARIABLE THROUGH THE WEEK. WITH CLOUDS AROUND ON FRIDAY THE TEMPERATURES WILL BE A BIT COOLER...WARMING AFTER THE WARM FRONT LIFTS TO THE NORTH FOR SATURDAY AND SUNDAY THEN COOLING AGAIN AS THE COOL FRONT MOVE THROUGH MONDAY AND TUESDAY AND COOLING MORE AFTER THE FRONT MOVES THROUGH TUESDAY. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ 946 UPDATE...BRYANT AVIATION...HEINLEIN SHORT/419 UPDATE...ROSSI LONG TERM...JCB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
637 PM CDT WED MAY 23 2012 .AVIATION...00Z KGRI TAF. THUNDERSTORM DEVELOPMENT COULD OCCUR ALONG A SURFACE COLD FRONT CONTINUING TO MOVE TO THE SOUTHEAST. THIS SURFACE CONVECTION SHOULD REMAIN SOUTHEAST OF THE TERMINAL. LATER ON TOWARD LATE EVENING...A LOW-LEVEL JET WILL ENCOURAGE SEVERE THUNDERSTORMS TO DEVELOP AND LINGER INTO THE EARLY OVERNIGHT HOURS. WIND MAY BE A BIT GUSTY FOR THURSDAY...WITH SOME SMALL CHANCES OF THUNDERSTORMS. HOWEVER...CHANCES OF PRECIPITATION ON THURSDAY ARE SMALL ENOUGH TO LEAVE OUT OF THE FORECAST FOR NOW. && .PREV DISCUSSION... /ISSUED 419 PM CDT WED MAY 23 2012/ UPDATE...SENT AN UPDATE TO THE FORECAST TO INCLUDE SEVERE THUNDERSTORM WATCH 293 FOR PORTIONS OF THE FORECAST AREA THROUGH 11 PM CDT. THE GREATEST POTENTIAL FOR ANY SEVERE STORMS WILL REMAIN WITH AND ALONG EITHER SIDE OF A SLOWLY PROGRESSING COLD FRONT...WITH LARGE HAIL AND DAMAGING WIND GUSTS BEING THE PRIMARY CONCERNS WITH ANY STORMS THAT DO DEVELOP. PREV DISCUSSION... /ISSUED 400 PM CDT WED MAY 23 2012/ SHORT TERM...A FAIRLY ACTIVE START TO THE FORECAST IS EXPECTED THIS EVENING AS A COLD FRONT SLOWLY MAKES ITS WAY ACROSS SOUTH CENTRAL NEBRASKA AND NORTH CENTRAL KANSAS...WITH AN ASSOCIATED MID LEVEL LOW PRESSURE SYSTEM TO THE WEST EXPECTED TO HELP BRING SOME WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY ACROSS MUCH OF THE FORECAST AREA DURING THE OVERNIGHT HOURS TONIGHT. SHORT TERM MODELS ARE IN MODERATE DISAGREEMENT WITH INITIATION OF CONVECTION ALONG A PASSING COLD FRONT...CURRENTLY DRAPED FROM NEAR NORFOLK...ACROSS GRAND ISLAND...SOUTH WESTWARD TOWARDS HOLDREGE. THIS FRONT HAS BEEN VERY SLOW TO WORK ITS WAY ACROSS THE FORECAST AREA THIS AFTERNOON...AND SO FAR HAS YET TO PRODUCE ENOUGH FORCING TO BREAK LOW LEVEL CAP. 12Z NAM AND WRF BOTH DID TRY AND INITIATE CONVECTION...BUT 18Z NAM AND LATEST HRRR BOTH HOLD OFF ANY WIDESPREAD SHOWER OR THUNDERSTORM ACTIVITY TILL FORCING FROM MID LEVEL LOW TO OUR WEST APPROACHES CENTRAL NEBRASKA AROUND MIDNIGHT. THAT BEING SAID...INGREDIENTS ARE IN PLACE...AS LATEST MESO ANALYSIS SHOWS A FINGER OF 2000+ J/KG OF CAPE ACROSS THE LOCAL AREA NEAR THE SLOWLY PROGRESSING FRONT...AND LITTLE INHIBITION AS WELL AS DEVELOPING CU FIELD IN SATELLITE. PER CONSENSUS AMONG MODELS...DID BACK OFF ON INITIATION OF CONVECTION THIS AFTERNOON...BUT INSERTED MENTION OF SEVERE STORMS AFTER 00Z...AS COMBINATION OF SHEAR AND INSTABILITY SHOULD BE SUFFICIENT FOR SOME SUPERCELLS TO DEVELOP IF INITIATION CAN BE REALIZED NEAR THE FRONT. BEHIND THE FRONT...AS THE MID LEVEL SHORTWAVE APPROACHES THE REGION...BROADER SCALE FORCING SHOULD BE AMPLE ENOUGH TO DEVELOP WIDESPREAD CONVECTION ACROSS THE LOCAL AREA BY AROUND MIDNIGHT...CONTINUING INTO THE OVERNIGHT HOURS...SO THE POTENTIAL FOR SEVERE HAIL AND STRONG WINDS REMAIN A CONCERN. THEREAFTER...THE ATMOSPHERE SHOULD BEGIN TO STABILIZE BEHIND THE DEPARTING MID LEVEL WAVE...WITH A SMALL CHANCE FOR SHOWERS AND AN ISOLATED THUNDERSTORM CONTINUING INTO THE AFTERNOON HOURS WITH NEAR TO SLIGHTLY BELOW SEASONAL TEMPERATURES EXPECTED DURING THE AFTERNOON. LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY. MAIN FORECAST CONCERNS WILL BE CHANCES FOR THUNDERSTORMS THROUGH MOST OF THE PERIOD AND TEMPERATURES. ZONAL TO SOUTHWEST FLOW GIVES WAY TO NORTHWEST FLOW. THERE ARE SEVERAL WAVES THAT MOVE THROUGH THE AREA DURING THE PERIOD. THE FIRST WAVE MOVES INTO THE AREA THURSDAY NIGHT INTO FRIDAY. THERE WILL BE A CHANCE FOR SOME THUNDERSTORMS. ON FRIDAY A SURFACE LOW DEVELOPING IN KANSAS WILL LIFT A WARM FRONT NORTH INTO THE FORECAST AREA. WITH THE FRONT MOVING THROUGH AND THE ANOTHER UPPER WAVE MOVING INTO THE AREA THERE IS A BETTER CHANCE FOR THUNDERSTORMS. SOME OF THESE STORMS COULD BE STRONG TO SEVERE. SATURDAY AND SATURDAY NIGHT THERE ARE WEAK WAVES THAT MOVES THROUGH BUT LITTLE IN THE WAY TO GET THINGS STARTED SO ANY PRECIPITATION WILL BE SPOTTY. THE NEXT CHANCE FOR SOME THUNDERSTORMS WILL BE SUNDAY INTO SUNDAY NIGHT. ANOTHER STRONGER WAVE MOVES INTO THE AREA AND A COLD FRONT MOVES THROUGH THE AREA SUNDAY AFTERNOON AND EVENING. THUNDERSTORMS WILL DEVELOP ALONG THE FRONT AS IT MOVES THROUGH. SOME OF THESE COULD BE SEVERE. MONDAY AND MONDAY NIGHT THE UPPER WAVE MOVES TO THE EAST AND A SURFACE HIGH PRESSURE MOVES INTO THE AREA...KEEPING THINGS DRY. AGAIN TUESDAY INTO TUESDAY NIGHT THERE ARE A FEW WEAK UPPER LEVEL WAVES THAT MOVE INTO THE PLAINS. MODELS HAVE SOME FAIRLY SPOTTY PRECIPITATION AROUND THE AREA WITH THESE UPPER LEVEL WAVES. THE GFS HAS MORE PRECIPITATION AROUND THAN THE ECMWF DOES. TEMPERATURES WILL BE SOMEWHAT VARIABLE THROUGH THE WEEK. WITH CLOUDS AROUND ON FRIDAY THE TEMPERATURES WILL BE A BIT COOLER...WARMING AFTER THE WARM FRONT LIFTS TO THE NORTH FOR SATURDAY AND SUNDAY THEN COOLING AGAIN AS THE COOL FRONT MOVE THROUGH MONDAY AND TUESDAY AND COOLING MORE AFTER THE FRONT MOVES THROUGH TUESDAY. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ AVIATION...HEINLEIN SHORT TERM/UPDATE...ROSSI LONG TERM...JCB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1214 AM CDT TUE MAY 22 2012 .AVIATION...06Z KGRI TAF. VFR CEILING/VISIBILITY WILL HOLD FIRM THROUGH THE PERIOD...WITH NOTHING MORE THAN VARYING DEGREES OF PASSING MID AND HIGH LEVEL CLOUDS. HOWEVER...STRONG SOUTHERLY WIND WILL BE AN ISSUE DURING THE PERIOD. INITIALLY BEFORE SUNRISE...SUSTAINED SPEEDS WILL AVERAGE NEAR 14KT...BUT A STEADY RAMP-UP WILL TAKE PLACE DURING THE DAY...WITH SUSTAINED SPEEDS TOPPING OUT NEAR 23KT AND GUST POTENTIAL TO NEAR 32KT...WHICH IS A SLIGHT INCREASE OVER SPEEDS INDICATED IN THE PREVIOUS TAF ISSUANCE. EVEN AFTER NIGHTFALL TUESDAY EVENING...GUSTS TO TO AROUND 26KT WILL PERSIST. LOOKING ABOVE THE SURFACE...A STRENGTHENING LOW LEVEL JET WILL RESULT IN ENOUGH SPEED SHEAR IN THE LOWEST 1500 FT AGL TO JUSTIFY A MENTION OF LOW LEVEL WIND SHEAR THROUGH THE FIRST SEVERAL HOURS OF THE PERIOD. FINALLY...WILL INSERT A VICINITY SHOWER MENTION FOR THE FIRST SEVERAL HOURS OF THE PERIOD AS WELL TO ACCOUNT FOR THE POSSIBILITY OF A BRIEF SHOWER MOVING IN FROM THE NORTHWEST. && .PREV DISCUSSION... /ISSUED 1148 PM CDT MON MAY 21 2012/ UPDATE...EVENING UPPER AIR ANALYSIS INDICATES RIDGING OVER THE WESTERN CONUS WITH TROUGHING OVER THE EAST. MID AND UPPER LEVEL FLOW OVER THE CENTRAL PLAINS REMAIN FROM THE NORTHWEST AS A RESULT. THAT BEING SAID...THE PRIMARY AXIS OF MID AND UPPER LEVEL JET ENERGY IS RELEGATED TO THE NORTHWESTERN CONUS THUS LEAVING TROPOSPHERIC FLOW FAIRLY WEAK OVER OUR AREA...WITH THE ONLY EXCEPTION BEING CLOSER TO 850MB WHERE A 20-30KT LOW LEVEL JET STREAK IS NOTED EXTENDING FROM WESTERN KANSAS INTO WESTERN NEBRASKA. WATER VAPOR IMAGERY SHOWS INCREASED VALUES OF MID LEVEL MOISTURE FLOWING INTO THE WESTERN CONUS FROM THE PACIFIC...SOME OF WHICH IS BEGINNING TO SPILL OVER THE WESTERN CONUS RIDGE THUS RESULTING IN INCREASING MID TO HIGH LEVEL CLOUDS ACROSS THE NORTHERN AND CENTRAL PLAINS. WATER VAPOR IMAGERY ALSO SHOW A MID LEVEL LOW TO THE SOUTHEAST OF THE ALEUTIAN ISLANDS...WITH A MID LEVEL SHORT WAVE PIVOTING TO THE SOUTH OF THE LOW. AT THE SURFACE A RIDGE OF HIGH PRESSURE IS NOTED OVER THE MISSISSIPPI VALLEY WITH TROUGHING OVER THE FRONT RANGE...THUS HELPING PROMOTE SOUTH/SOUTHEASTERLY LOW LEVEL FLOW ACROSS THE CENTRAL PLAINS. KUEX CONTINUES TO INDICATE THE LEADING EDGE OF CONVECTIVE ACTIVITY EXTENDING FROM NEAR KODX TO NEAR BEAVER CITY AND MOVING SOUTHEAST. THIS ACTIVITY IS LIKELY BEING REINFORCED BY LOW LEVEL THERMAL ADVECTION ALONG THE AXIS OF THE LOW LEVEL JET CURRENTLY NEAR THE AREA. SHORT TERM GUIDANCE PER THE RAP AND NAM SUGGEST THIS LOW LEVEL JET WILL PUSH EAST AND BECOME MORE ORIENTED FROM THE SOUTHWEST TO NORTHEAST ACROSS OUR AREA THROUGH 12Z. GIVEN THIS...IT IS AT LEAST POSSIBLE ISOLATED TO PERHAPS SCATTERED PRECIPITATION WILL PERSIST OVER PORTIONS OF THE CWA THROUGH THE OVERNIGHT HOURS. SPC MESO-ANALYSIS SUGGESTS THE PRIMARY INSTABILITY AXIS EXISTS TO OUR WEST OVER THE HIGH PLAINS...BUT IT IS POSSIBLE THIS INSTABILITY AXIS...WITH PERHAPS AROUND 100J/KG DEEP LAYER MUCAPE...COULD SPREAD EAST MORE INTO OUR AREA AS MOISTURE ADVECTION ALONG THE LOW LEVEL JET AXIS ALSO PUSHES INTO OUR AREA. GIVEN ALL THIS...WENT AHEAD AND EXTENDED SLIGHT CHANCE POPS ACROSS ROUGHLY THE NORTHWESTERN HALF OF THE CWA THROUGH 12Z...WHICH MATCHES UP FAIRLY CLOSELY WITH THE ANTICIPATED POSITION OF THE LOW LEVEL JET AXIS THROUGH 12Z. ALTHOUGH INSTABILITY IS EXTREMELY LIMITED OVER OUR AREA AT THIS HOUR...GIVEN THE POSSIBILITY OF SOMEWHAT INCREASING INSTABILITY ACROSS OUR AREA...WENT AHEAD AND ALSO KEPT THE ISOLATED THUNDER MENTION IN THE FORECAST FOR TONIGHT. PREV DISCUSSION... /ISSUED 1021 PM CDT MON MAY 21 2012/ UPDATE...UPDATED THE FORECAST THIS EVENING FOR SOME POSSIBLE LIGHT PRECIPITATION IN OUR FAR WEST/NORTHWEST CWA AS THUNDERSTORMS TO THE WEST DWINDLE. LITTLE SHEAR AND INSTABILITY TO HELP SUPPORT THESE CELLS AND THEY SHOULD DIE OUT IN THE NEXT FEW HOURS. PREV DISCUSSION... /ISSUED 403 PM CDT MON MAY 21 2012/ SHORT TERM...TONIGHT AND TOMORROW. A QUICK UPPER LEVEL ANALYSIS INDICATES AN UPPER LEVEL CLOSED LOW PUSHING OFF THE EAST COAST WHILE THE TROUGH AXIS REMAINS ORIENTED ACROSS THE MISSISSIPPI VALLEY REGION. BUILDING IN ACROSS THE WESTERN HALF OF THE CONUS...AN UPPER LEVEL RIDGE HAS BEGUN TO DOMINATE MUCH OF THE ROCKY MOUNTAIN WEATHER. SEVERAL WEAK SHORT WAVE PERTURBATIONS REMAIN IN THE DOMINATE FLOW...INCLUDING ONE ACROSS THE FRONT RANGE. A SURGE OF MOISTURE IN THE MID LEVELS HAS POOLED UNDER AN AREA OF HIGH PRESSURE ACROSS THE TEXAS PANHANDLE...BUT SOME SCANT AMOUNTS HAVE SURGED AS FAR NORTH AS SOUTH DAKOTA ACROSS WESTERN NEBRASKA. AT THE SURFACE...A LARGE AREA OF HIGH PRESSURE HAS LAGGED ACROSS THE CENTRAL CONUS STRETCHING FROM CANADA TO TEXAS...WHILE WEAK LOW PRESSURE HAS BEGUN TO DEVELOP ACROSS THE FRONT RANGE. BEGINNING THE SHORT TERM...THE PLAINS REMAIN UNDER THE INFLUENCE OF THE INCOMING RIDGE AND ASSOCIATED SURFACE HIGH. THIS HIGH PRESSURE SYSTEM WILL BEGIN TO SHIFT EASTWARD AS THE MAIN FOCUS OF THE SHORT TERM SHIFTS TO THE INCOMING SURFACE LOW/TROUGH. A FEW CONCERNS DURING THE OVERNIGHT PERIOD WILL BE THE INCREASE IN THE LOW LEVEL JET OVERNIGHT. MODELS INCREASE 850 MB WINDS TO NEAR 40 KTS OVERNIGHT...WITH THE GFS AND THE ECMWF JET LOCATIONS ACROSS THE WESTERN HALF OF THE STATE AND THE NAM A BIT FURTHER EAST. BOTH THE NAM AND THE GFS SOLUTION GENERATE SOME POPS WITH THE LOW LEVEL JET...HOWEVER...THE NAM MODEL REMAINS FURTHER WEST...WHILE THE GFS GENERATES POPS ACROSS THE FORECAST AREA. THE 4 KM WRF MODEL DOES NOT PICK UP ON ANY SUGGESTION OF POTENTIAL POPS DURING THE OVERNIGHT PERIOD. DECIDED TO LEAVE THE OVERNIGHT PERIOD DRY...BUT THIS COULD BE A CONCERN GIVEN THE LOW LEVEL JET AXIS. LEADING TOWARDS THE DAYTIME HOURS ON TUESDAY...THE SURFACE TROUGH WILL CONTINUE TO PUSH EASTWARD...HELPING TIGHTEN THE PRESSURE GRADIENT ACROSS THE PLAINS. AS A RESULT...INCREASED SOUTH WINDS WILL BE PREVALENT DURING THE LATE MORNING AND AFTERNOON HOURS ON TUESDAY. MODELS TRENDS HAVE REMAINED FAIRLY CONSISTENT BETWEEN RUNS...ALTHOUGH MODEL GUIDANCE AS BEEN TRENDING DOWN SINCE PREVIOUS RUNS. GIVEN THAT MODELS AND GUIDANCE REMAIN ONLY MARGINAL WIND ADVISORY AT BEST IN ONLY A FEW LOCATIONS...DECIDED TO OPT OUT OF ISSUING A WIND ADVISORY AT THIS POINT. REGARDING TEMPERATURES ON TUESDAY...AS THE UPPER LEVEL RIDGE BUILDS ACROSS THE PLAINS AND BOUNDARY LAYER MIXING IS EXPECTED TO AT LEAST 850 MB IF NOT 800 MB...SEE NO REASON WHY WE CANNOT TAP INTO SOME WARM TEMPERATURES. THE NAM AND THE ECMWF REMAIN IN GOOD AGREEMENT WITH A TEMPERATURE GRADIENT FROM POSSIBLY THE LOW 90S OUT WEST TO LOW 80S IN THE EAST...THUS SUGGESTING A GRADIENT OF ABOUT 7 TO 10 DEGREES. THE GFS SOLUTION REMAINS THE OUTLIER WITH A MUCH COOLER GRADIENT WITH MID 80S OUT WEST AND MID 70S EAST. DECIDED TO LEAN MORE WITH THE NAM/EC SOLUTION ALTHOUGH PORTIONS FARTHER WEST COULD BE A BIT WARMER AND PORTIONS FARTHER EAST COULD BE A BIT COOLER THAN FORECAST. LONG TERM...00Z WED THROUGH MONDAY. OFF AND ON CHANCES FOR PRECIPITATION DURING THE EXTENDED WILL BE MAIN CONCERN AS PATTERN BECOMES MORE ACTIVE. WEAK MID LEVEL RIDGE SHOULD BEGIN TO SLIDE TO OUR EAST OVERNIGHT TUESDAY AND LOW AMPLITUDE TROUGH BEGINS TO PUSH INTO THE NW U.S. FIRST WAVE OF ENERGY WILL KICK OUT AND PUSH A COLD FRONT INTO THE CENTRAL PLAINS DURING THE DAYTIME ON WED. SHOULD BE ENTERING THE NW PART OF THE CWA BY SUNRISE WED AND PUSH THROUGH DURING THE DAY. NAM MORE PROGRESSIVE THAN THE GFS WITH THIS FRONT. ALL MODELS SHOWING DECENT CAP OVER THE SE HALF OF THE CWA DURING THE AFTERNOON AND BANKING ON THIS FEATURE TO KEEP THUNDERSTORMS AT BAY DURING THE DAY. CHANCES INCREASE ESPECIALLY IN THE NORTHERN PART OF THE CWA WED EVENING AND OVERNIGHT AS MID LEVEL WAVE ROTATES THROUGH HELPING COOL OFF MID LEVEL TEMPS ESPECIALLY IN THE NORTH. GFS AND OLD EC MODELS DO SHOW THE BETTER JET SUPPORT TO BE JUST A LITTLE NORTH OF US WITH RIGHT ENTRANCE AND LEFT EXIT REGIONS OF COUPLED JET FAVORING NW NEB. MODELS ALSO SHOWING BEST MID LEVEL FRONTOGENESIS IN THIS AREA. WILL WAIT TO GET A LOOK AT THE 12Z EC RUN BUT UNLESS IT SHOWS SOMETHING DIFFERENT WILL KEEP WITH PREVIOUS THINKING OF BEST CHANCES FOR THUNDERSTORMS IN THE NORTHWEST CWA AND DRY IN OUR FAR SOUTHEAST AS CAP EXPECTED TO HOLD AND EVEN STRENGTHEN IN THAT AREA OVERNIGHT. IN REGARDS TO SEVERE POTENTIAL...DEEP LAYER SHEAR AND MU CAPE WOULD SUPPORT SOME SEVERE IN THE AREA. THURSDAY/THUR NIGHT NOT REAL CLEAR CUT AS MODELS DIFFERING ON PRECIP CHANCES. INITIAL THOUGHT IS THAT WE WON`T SEE MUCH DURING THE DAY AND THEN CHANCES INCREASE SOME OVERNIGHT AS LOW LEVEL INCREASES. HOWEVER WILL LEAVE AT LEAST A SMALL CHANCE IN THE NORTH DURING THE DAYTIME. AS FIRST WAVE EJECTS TO OUR NORTH...ANOTHER DEEPER MID LEVEL LOW PRESSURE SYSTEM IS PROGGED TO DIG FROM THE PACIFIC NW ON THURSDAY INTO SOUTHERN NEVADA BY SATURDAY BEFORE LIFTING NORTH INTO SOUTHERN MANITOBA BY MONDAY NIGHT. THIS TRACK IS MAINLY BASED OFF THE EC AND IF IT HOLDS TRUE...WE SHOULD BE DRY DURING THE DAYTIME ON FRIDAY WITH SHORT WAVE RIDGING. STILL LINGERING CHANCES FOR RAIN FRIDAY NIGHT INTO SATURDAY NIGHT WITH WARM FRONT LIFTING NORTH AND CYCLONIC FLOW IN THE UPPER LEVELS. SUNDAY COULD BE INTERESTING AS COLD FRONT SWEEPS THROUGH DURING THE AFTERNOON. EARLY LOOK AT CAPE AND SHEAR WOULD POINT TO SEVERE WEATHER CHANCE BUT AS USUAL THAT WILL DEPEND ON TIMING OF A SYSTEM WHICH IS STILL SEVERAL DAYS AWAY. AS FAR AS HIGH TEMPERATURES GO...WE WILL SEE SOME VARIATION AS FRONTAL BOUNDARIES PUSH THROUGH...WITH THINGS A LITTLE COOLER ON WED IN THE NORTH CWA AND THEN OVER THE ENTIRE AREA THURS AND FRI BEFORE IT WARMS UP AGAIN ON SAT INTO SUNDAY AHEAD OF NEXT COLD FRONT. NEXT MONDAY SHOULD ONCE AGAIN BE A LITTLE COOLER BEHIND THE FRONT. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ AVIATION...PFANNKUCH 1148 PM UPDATE...BRYANT 1021 PM UPDATE...HEINLEIN SHORT TERM...SALTZMAN LONG TERM...EWALD
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1148 PM CDT MON MAY 21 2012 .UPDATE...EVENING UPPER AIR ANALYSIS INDICATES RIDGING OVER THE WESTERN CONUS WITH TROUGHING OVER THE EAST. MID AND UPPER LEVEL FLOW OVER THE CENTRAL PLAINS REMAIN FROM THE NORTHWEST AS A RESULT. THAT BEING SAID...THE PRIMARY AXIS OF MID AND UPPER LEVEL JET ENERGY IS RELEGATED TO THE NORTHWESTERN CONUS THUS LEAVING TROPOSPHERIC FLOW FAIRLY WEAK OVER OUR AREA...WITH THE ONLY EXCEPTION BEING CLOSER TO 850MB WHERE A 20-30KT LOW LEVEL JET STREAK IS NOTED EXTENDING FROM WESTERN KANSAS INTO WESTERN NEBRASKA. WATER VAPOR IMAGERY SHOWS INCREASED VALUES OF MID LEVEL MOISTURE FLOWING INTO THE WESTERN CONUS FROM THE PACIFIC...SOME OF WHICH IS BEGINNING TO SPILL OVER THE WESTERN CONUS RIDGE THUS RESULTING IN INCREASING MID TO HIGH LEVEL CLOUDS ACROSS THE NORTHERN AND CENTRAL PLAINS. WATER VAPOR IMAGERY ALSO SHOW A MID LEVEL LOW TO THE SOUTHEAST OF THE ALEUTIAN ISLANDS...WITH A MID LEVEL SHORT WAVE PIVOTING TO THE SOUTH OF THE LOW. AT THE SURFACE A RIDGE OF HIGH PRESSURE IS NOTED OVER THE MISSISSIPPI VALLEY WITH TROUGHING OVER THE FRONT RANGE...THUS HELPING PROMOTE SOUTH/SOUTHEASTERLY LOW LEVEL FLOW ACROSS THE CENTRAL PLAINS. KUEX CONTINUES TO INDICATE THE LEADING EDGE OF CONVECTIVE ACTIVITY EXTENDING FROM NEAR KODX TO NEAR BEAVER CITY AND MOVING SOUTHEAST. THIS ACTIVITY IS LIKELY BEING REINFORCED BY LOW LEVEL THERMAL ADVECTION ALONG THE AXIS OF THE LOW LEVEL JET CURRENTLY NEAR THE AREA. SHORT TERM GUIDANCE PER THE RAP AND NAM SUGGEST THIS LOW LEVEL JET WILL PUSH EAST AND BECOME MORE ORIENTED FROM THE SOUTHWEST TO NORTHEAST ACROSS OUR AREA THROUGH 12Z. GIVEN THIS...IT IS AT LEAST POSSIBLE ISOLATED TO PERHAPS SCATTERED PRECIPITATION WILL PERSIST OVER PORTIONS OF THE CWA THROUGH THE OVERNIGHT HOURS. SPC MESO-ANALYSIS SUGGESTS THE PRIMARY INSTABILITY AXIS EXISTS TO OUR WEST OVER THE HIGH PLAINS...BUT IT IS POSSIBLE THIS INSTABILITY AXIS...WITH PERHAPS AROUND 100J/KG DEEP LAYER MUCAPE...COULD SPREAD EAST MORE INTO OUR AREA AS MOISTURE ADVECTION ALONG THE LOW LEVEL JET AXIS ALSO PUSHES INTO OUR AREA. GIVEN ALL THIS...WENT AHEAD AND EXTENDED SLIGHT CHANCE POPS ACROSS ROUGHLY THE NORTHWESTERN HALF OF THE CWA THROUGH 12Z...WHICH MATCHES UP FAIRLY CLOSELY WITH THE ANTICIPATED POSITION OF THE LOW LEVEL JET AXIS THROUGH 12Z. ALTHOUGH INSTABILITY IS EXTREMELY LIMITED OVER OUR AREA AT THIS HOUR...GIVEN THE POSSIBILITY OF SOMEWHAT INCREASING INSTABILITY ACROSS OUR AREA...WENT AHEAD AND ALSO KEPT THE ISOLATED THUNDER MENTION IN THE FORECAST FOR TONIGHT. && .PREV DISCUSSION... /ISSUED 1021 PM CDT MON MAY 21 2012/ UPDATE...UPDATED THE FORECAST THIS EVENING FOR SOME POSSIBLE LIGHT PRECIPITATION IN OUR FAR WEST/NORTHWEST CWA AS THUNDERSTORMS TO THE WEST DWINDLE. LITTLE SHEAR AND INSTABILITY TO HELP SUPPORT THESE CELLS AND THEY SHOULD DIE OUT IN THE NEXT FEW HOURS. PREV DISCUSSION... /ISSUED 700 PM CDT MON MAY 21 2012/ AVIATION...00Z KGRI TAF. VFR CONDITIONS WITH WIND KICKING UP ON TUESDAY. ANY STORMS TO THE WEST SHOULD DIE OFF BEFORE REACHING THE TERMINAL TONIGHT. PREV DISCUSSION... /ISSUED 403 PM CDT MON MAY 21 2012/ SHORT TERM...TONIGHT AND TOMORROW. A QUICK UPPER LEVEL ANALYSIS INDICATES AN UPPER LEVEL CLOSED LOW PUSHING OFF THE EAST COAST WHILE THE TROUGH AXIS REMAINS ORIENTED ACROSS THE MISSISSIPPI VALLEY REGION. BUILDING IN ACROSS THE WESTERN HALF OF THE CONUS...AN UPPER LEVEL RIDGE HAS BEGUN TO DOMINATE MUCH OF THE ROCKY MOUNTAIN WEATHER. SEVERAL WEAK SHORT WAVE PERTURBATIONS REMAIN IN THE DOMINATE FLOW...INCLUDING ONE ACROSS THE FRONT RANGE. A SURGE OF MOISTURE IN THE MID LEVELS HAS POOLED UNDER AN AREA OF HIGH PRESSURE ACROSS THE TEXAS PANHANDLE...BUT SOME SCANT AMOUNTS HAVE SURGED AS FAR NORTH AS SOUTH DAKOTA ACROSS WESTERN NEBRASKA. AT THE SURFACE...A LARGE AREA OF HIGH PRESSURE HAS LAGGED ACROSS THE CENTRAL CONUS STRETCHING FROM CANADA TO TEXAS...WHILE WEAK LOW PRESSURE HAS BEGUN TO DEVELOP ACROSS THE FRONT RANGE. BEGINNING THE SHORT TERM...THE PLAINS REMAIN UNDER THE INFLUENCE OF THE INCOMING RIDGE AND ASSOCIATED SURFACE HIGH. THIS HIGH PRESSURE SYSTEM WILL BEGIN TO SHIFT EASTWARD AS THE MAIN FOCUS OF THE SHORT TERM SHIFTS TO THE INCOMING SURFACE LOW/TROUGH. A FEW CONCERNS DURING THE OVERNIGHT PERIOD WILL BE THE INCREASE IN THE LOW LEVEL JET OVERNIGHT. MODELS INCREASE 850 MB WINDS TO NEAR 40 KTS OVERNIGHT...WITH THE GFS AND THE ECMWF JET LOCATIONS ACROSS THE WESTERN HALF OF THE STATE AND THE NAM A BIT FURTHER EAST. BOTH THE NAM AND THE GFS SOLUTION GENERATE SOME POPS WITH THE LOW LEVEL JET...HOWEVER...THE NAM MODEL REMAINS FURTHER WEST...WHILE THE GFS GENERATES POPS ACROSS THE FORECAST AREA. THE 4 KM WRF MODEL DOES NOT PICK UP ON ANY SUGGESTION OF POTENTIAL POPS DURING THE OVERNIGHT PERIOD. DECIDED TO LEAVE THE OVERNIGHT PERIOD DRY...BUT THIS COULD BE A CONCERN GIVEN THE LOW LEVEL JET AXIS. LEADING TOWARDS THE DAYTIME HOURS ON TUESDAY...THE SURFACE TROUGH WILL CONTINUE TO PUSH EASTWARD...HELPING TIGHTEN THE PRESSURE GRADIENT ACROSS THE PLAINS. AS A RESULT...INCREASED SOUTH WINDS WILL BE PREVALENT DURING THE LATE MORNING AND AFTERNOON HOURS ON TUESDAY. MODELS TRENDS HAVE REMAINED FAIRLY CONSISTENT BETWEEN RUNS...ALTHOUGH MODEL GUIDANCE AS BEEN TRENDING DOWN SINCE PREVIOUS RUNS. GIVEN THAT MODELS AND GUIDANCE REMAIN ONLY MARGINAL WIND ADVISORY AT BEST IN ONLY A FEW LOCATIONS...DECIDED TO OPT OUT OF ISSUING A WIND ADVISORY AT THIS POINT. REGARDING TEMPERATURES ON TUESDAY...AS THE UPPER LEVEL RIDGE BUILDS ACROSS THE PLAINS AND BOUNDARY LAYER MIXING IS EXPECTED TO AT LEAST 850 MB IF NOT 800 MB...SEE NO REASON WHY WE CANNOT TAP INTO SOME WARM TEMPERATURES. THE NAM AND THE ECMWF REMAIN IN GOOD AGREEMENT WITH A TEMPERATURE GRADIENT FROM POSSIBLY THE LOW 90S OUT WEST TO LOW 80S IN THE EAST...THUS SUGGESTING A GRADIENT OF ABOUT 7 TO 10 DEGREES. THE GFS SOLUTION REMAINS THE OUTLIER WITH A MUCH COOLER GRADIENT WITH MID 80S OUT WEST AND MID 70S EAST. DECIDED TO LEAN MORE WITH THE NAM/EC SOLUTION ALTHOUGH PORTIONS FARTHER WEST COULD BE A BIT WARMER AND PORTIONS FARTHER EAST COULD BE A BIT COOLER THAN FORECAST. LONG TERM...00Z WED THROUGH MONDAY. OFF AND ON CHANCES FOR PRECIPITATION DURING THE EXTENDED WILL BE MAIN CONCERN AS PATTERN BECOMES MORE ACTIVE. WEAK MID LEVEL RIDGE SHOULD BEGIN TO SLIDE TO OUR EAST OVERNIGHT TUESDAY AND LOW AMPLITUDE TROUGH BEGINS TO PUSH INTO THE NW U.S. FIRST WAVE OF ENERGY WILL KICK OUT AND PUSH A COLD FRONT INTO THE CENTRAL PLAINS DURING THE DAYTIME ON WED. SHOULD BE ENTERING THE NW PART OF THE CWA BY SUNRISE WED AND PUSH THROUGH DURING THE DAY. NAM MORE PROGRESSIVE THAN THE GFS WITH THIS FRONT. ALL MODELS SHOWING DECENT CAP OVER THE SE HALF OF THE CWA DURING THE AFTERNOON AND BANKING ON THIS FEATURE TO KEEP THUNDERSTORMS AT BAY DURING THE DAY. CHANCES INCREASE ESPECIALLY IN THE NORTHERN PART OF THE CWA WED EVENING AND OVERNIGHT AS MID LEVEL WAVE ROTATES THROUGH HELPING COOL OFF MID LEVEL TEMPS ESPECIALLY IN THE NORTH. GFS AND OLD EC MODELS DO SHOW THE BETTER JET SUPPORT TO BE JUST A LITTLE NORTH OF US WITH RIGHT ENTRANCE AND LEFT EXIT REGIONS OF COUPLED JET FAVORING NW NEB. MODELS ALSO SHOWING BEST MID LEVEL FRONTOGENESIS IN THIS AREA. WILL WAIT TO GET A LOOK AT THE 12Z EC RUN BUT UNLESS IT SHOWS SOMETHING DIFFERENT WILL KEEP WITH PREVIOUS THINKING OF BEST CHANCES FOR THUNDERSTORMS IN THE NORTHWEST CWA AND DRY IN OUR FAR SOUTHEAST AS CAP EXPECTED TO HOLD AND EVEN STRENGTHEN IN THAT AREA OVERNIGHT. IN REGARDS TO SEVERE POTENTIAL...DEEP LAYER SHEAR AND MU CAPE WOULD SUPPORT SOME SEVERE IN THE AREA. THURSDAY/THUR NIGHT NOT REAL CLEAR CUT AS MODELS DIFFERING ON PRECIP CHANCES. INITIAL THOUGHT IS THAT WE WON`T SEE MUCH DURING THE DAY AND THEN CHANCES INCREASE SOME OVERNIGHT AS LOW LEVEL INCREASES. HOWEVER WILL LEAVE AT LEAST A SMALL CHANCE IN THE NORTH DURING THE DAYTIME. AS FIRST WAVE EJECTS TO OUR NORTH...ANOTHER DEEPER MID LEVEL LOW PRESSURE SYSTEM IS PROGGED TO DIG FROM THE PACIFIC NW ON THURSDAY INTO SOUTHERN NEVADA BY SATURDAY BEFORE LIFTING NORTH INTO SOUTHERN MANITOBA BY MONDAY NIGHT. THIS TRACK IS MAINLY BASED OFF THE EC AND IF IT HOLDS TRUE...WE SHOULD BE DRY DURING THE DAYTIME ON FRIDAY WITH SHORT WAVE RIDGING. STILL LINGERING CHANCES FOR RAIN FRIDAY NIGHT INTO SATURDAY NIGHT WITH WARM FRONT LIFTING NORTH AND CYCLONIC FLOW IN THE UPPER LEVELS. SUNDAY COULD BE INTERESTING AS COLD FRONT SWEEPS THROUGH DURING THE AFTERNOON. EARLY LOOK AT CAPE AND SHEAR WOULD POINT TO SEVERE WEATHER CHANCE BUT AS USUAL THAT WILL DEPEND ON TIMING OF A SYSTEM WHICH IS STILL SEVERAL DAYS AWAY. AS FAR AS HIGH TEMPERATURES GO...WE WILL SEE SOME VARIATION AS FRONTAL BOUNDARIES PUSH THROUGH...WITH THINGS A LITTLE COOLER ON WED IN THE NORTH CWA AND THEN OVER THE ENTIRE AREA THURS AND FRI BEFORE IT WARMS UP AGAIN ON SAT INTO SUNDAY AHEAD OF NEXT COLD FRONT. NEXT MONDAY SHOULD ONCE AGAIN BE A LITTLE COOLER BEHIND THE FRONT. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ 1148 UPDATE...BRYANT AVIATION/1021 UPDATE...HEINLEIN SHORT TERM...SALTZMAN LONG TERM...EWALD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
305 PM EDT TUE MAY 22 2012 .SYNOPSIS... AN UPPER DISTURBANCE WILL BRING SHOWERS AND THUNDERSTORMS TO THE AREA THROUGH THURSDAY. A WARMING AND DRYING TREND WILL FOLLOW FRIDAY THROUGH EARLY NEXT WEEK...AS AN UPPER RIDGE INTENSIFIES OVER THE CAROLINAS. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 1245 PM TUESDAY...RADAR SHOWS SHOWERS DEVELOPING ACROSS THE LOWER PEE DEE REGION WITH AN INCOMING VORTICITY LOBE...AND ALSO SOME ACTIVITY ACROSS NORTHERN SECTIONS OF PENDER AND BLADEN COUNTIES. VISIBLE SATELLITE (AND GLANCES OUT THE WINDOW) SHOW THE CUMULUS FIELD IN AND AROUND WILMINGTON IS PRIMED FOR ACTIVITY AS WELL. THIS REQUIRES ONLY SMALL CHANGES TO THE PREVIOUS FORECAST. DISCUSSION FROM 1030 AM FOLLOWS... TROPICAL DEPRESSION ALBERTO IS NO MORE. THE CONVECTION HAS BEEN SHEARED OFF AND AWAY FROM THE LOW-LEVEL CIRCULATION MEANING THERE IS NO LONGER A METHOD FOR ALBERTO TO EVACUATE AIR AND MAINTAIN LOWER PRESSURES IN THE CENTER OF THE CIRCULATION. ALBERTO`S REMNANT CIRCULATION IS CAUGHT UP IN THE SOUTHWEST FLOW AHEAD OF AN INCOMING NEGATIVELY TILTED UPPER LEVEL TROUGH THAT WILL MOVE FROM THE ALABAMA/GEORGIA BORDER THIS MORNING INTO SOUTH CAROLINA TONIGHT. THE NEGATIVE TILT SHOULD BECOME SO EXTREME TONIGHT THE SYSTEM ACTUALLY WILL CUT OFF INTO A CLOSED UPPER LOW WHICH SHOULD WOBBLE SLOWLY OVERHEAD WEDNESDAY. FALLING MID-LEVEL TEMPERATURES AND A JUICY SUBTROPICAL AIRMASS HERE AT THE SURFACE SPELL GROWING VERTICAL INSTABILITY...WITH CAPE VALUES RISING TO AROUND 1500 J/KG THIS AFTERNOON. WITH THE HELP OF MESOSCALE LIFT PROVIDED BY THE SEABREEZE FRONT...SHOWERS AND THUNDERSTORMS SHOULD DEVELOP EARLY THIS AFTERNOON JUST INLAND FROM THE COAST. THE ONLY AREAS THAT MIGHT BE COMPLETELY SPARED ARE THE SOUTH-FACING BEACHES WHERE COOLER ONSHORE WINDS BEHIND THE SEABREEZE WILL DEVELOP EARLY ENOUGH THIS AFTERNOON. THE LATEST HRRR SHOWS THIS CLASSIC WEATHER PATTERN WELL AND IS THE BASIS FOR OUR MORNING FORECAST UPDATE. BY MID TO LATE AFTERNOON CONTINUED HEATING INLAND AND THE APPROACH OF THE SURFACE COLD FRONT SHOULD PRODUCE SCATTERED SHOWERS AND STORMS INLAND AS WELL. SPC HAS CENTRAL SOUTH CAROLINA OUTLOOKED IN A "SLIGHT RISK" FOR SEVERE WEATHER WITH THE COLDER TEMPERATURES ALOFT AND BETTER SHEAR PROFILES CLOSER TO THE NEGATIVELY TILTED UPPER TROUGH. CONVECTIVE ACTIVITY MAY LINGER INTO THE EVENING...WITH PERHAPS A SECOND ROUND OF SHOWERS AND STORMS OVERNIGHT AS THE CORE OF THE COLDEST TEMPERATURES ALOFT ROTATE INTO EASTERN SOUTH CAROLINA. HIGHS TODAY SHOULD REACH THE MID 80S AWAY FROM THE OCEAN. LOWS TONIGHT SHOULD FALL TO 65-70...WARMEST AT THE BEACHES. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... AS OF 3 PM TUESDAY...BOTH WED AND THU WILL BE IMPACTED BY A COLD POOL ALOFT PASSING OVER THE FORECAST AREA...ALTHOUGH BY THURSDAY THIS FEATURE WILL BE EXITING TO THE NORTH AND TEMPS ALOFT WILL BEGIN WARMING...ESPECIALLY LATE IN THE DAY THURSDAY. POTENTIALLY SHARP LAPSE RATES WEDNESDAY AFTERNOON INTO EVENING WARRANTS MENTION OF HAIL AND GUSTY WINDS DESPITE ONLY "SEE TEXT" WORDING AT THIS TIME FROM SPC. 500MB TEMPS SHOULD DIP TO -15 TO -16 DEG CELSIUS OVERHEAD NEAR PEAK HEATING. MENTIONABLE POP VALUES EXTEND INTO THURSDAY BUT WARMING ALOFT MAY INHIBIT CONVECTION COMPARED TO WED. GREATER COVERAGE AND TSTM INTENSITY REMAINS FAVORED WED AFTERNOON AS THE CORE OF THE COOL POOL TRACK OVERHEAD. MAX TEMPS SIMILAR WED AND THU...MAINLY MIDDLE AND UPPER 80S ACROSS MOST INLAND LOCATIONS...AND LOWER 80S ALONG THE IMMEDIATE COAST. PRIMARILY MIDDLE 60S FOR LOWS EACH MORNING GIVEN ONSHORE FLOW AND PROJECTED DEWPOINTS. && .LONG TERM /THURSDAY THROUGH TUESDAY/... AS OF 3 PM TUESDAY...FEW CHANGES TO THE LONG TERM FORECAST THIS AFTERNOON WITH CONVECTION TAKING PRECEDENCE. MAIN THEME REMAINS HOT HOWEVER AS MEDIUM RANGE GUIDANCE CONTINUES TO BUILD THE 500MB RIDGE ACROSS THE SOUTHEAST FOR THE WEEKEND CONTINUING INTO MONDAY. THE PATTERN DOES SHOW INDICATIONS OF BREAKING DOWN TUESDAY AS CLOSED LOW IN THE WEST GETS KICKED OUT AND LOWERS HEIGHTS FROM NORTH TO SOUTH. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... AS OF 19Z...SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP THIS AFTERNOON AHEAD OF AN APPROACHING COLD FRONT AND UPPER IMPULSE. CONFIDENCE IN TIMING OF ACTIVITY INTO ANY TERMINAL IS ONLY LOW TO MODERATE. ONE IMPULSE MOVING THROUGH THE FLO TERMINALS ATTM SHOULD ENHANCE SEA BREEZE ACTIVITY FOR SEVERAL HOURS THIS AFTERNOON FROM MYR TO ILM. WILL INDICATE SHOWERS/WITH TEMPO MVFR AT ALL TERMINALS THIS AFTERNOON...WITH SHORT-TERM AMENDMENTS AS RADAR COVERAGE INDICATES. VCTS WILL BE MOST LIKELY AT THE COASTAL TERMINALS. SHORT PERIODS OF IFR ARE LIKELY WITH ANY THUNDERSTORMS BUT THE DURATION SHOULD BE TOO SHORT TO MENTION IN AT LEAST THE 18Z TAFS. THIS CONVECTION SHOULD END BY LATE AFTERNOON...WITH A SECOND ROUND OF CONVECTION DEVELOPING THIS EVENING PERSISTING UNTIL MIDNIGHT OR EVEN AFTER AS THE UPPER IMPULSE ROTATES THROUGH. THUNDERSTORM DEBRIS CLOUDINESS SHOULD SLOWLY THIS OUT AFTER THE PRECIPITATION ENDS AFTER MIDNIGHT...LEAVING THE WINDOW OPEN FOR BR DEVELOPMENT. ATTM WILL INDICATE ONLY MVFR CONDITIONS AT FLO/LBT DUE TO LIGHTER SURFACE WINDS AND LESS POTENTIAL CLOUD COVER. PATCHY DENSE FOG COULD OCCUR ESPECIALLY IN SHELTERED AREAS WHERE SKIES CLEAR OUT. ANY REDUCED FLIGHT CONDITIONS SHOULD IMPROVE RAPIDLY AROUND SUNRISE WITH SHOWERS AND THUNDERSTORMS AGAIN POSSIBLE BY MID MORNING. EXTENDED OUTLOOK...SCATTERED SHOWERS/MVFR...WITH ISOLATED THUNDERSTORMS/TEMPO IFR POSSIBLE THROUGH THE EXTENDED PERIOD. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1245 PM TUESDAY...CURRENT OBSERVATIONS MATCH THE PREVIOUS FORECAST CLOSELY...NO CHANGES ARE REQUIRED. PREVIOUS DISCUSSION FROM 1030 AM FOLLOWS... ALBERTO IS A DISSIPATING POST-TROPICAL DEPRESSION LOCATED ABOUT 250 MILES EAST-SOUTHEAST OF CAPE FEAR. WINDS ARE CURRENTLY SOUTH TO SOUTHWEST ACROSS OUR COASTAL WATERS INDICATING THERE HAS BEEN NO INFLUENCE FROM ALBERTO`S SMALL CIRCULATION. OUR WINDS ARE ACTUALLY INFLUENCED BY THE CYCLONIC FLOW AROUND AN AREA OF LOW PRESSURE AND COLD FRONT CURRENTLY ACROSS THE INLAND CAROLINAS. THIS SYSTEM IS NOT EXPECTED TO REACH THE COAST... INSTEAD STALLING TONIGHT AND DISSIPATING ON WEDNESDAY. UNTIL THEN... SOUTHWEST 10-15 KNOT WINDS ARE EXPECTED...STRONGEST ALONG THE COAST THIS AFTERNOON AND FARTHER AWAY FROM THE COAST TONIGHT. THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE SEABREEZE FRONT THIS AFTERNOON. SOME OF THESE COULD BE ON OR VERY NEAR THE BEACHES...SO MARINERS WILL WANT TO PAY CLOSE ATTENTION TO THE SKY EARLY THIS AFTERNOON. THERE SHOULD BE A LULL IN SHOWER/T-STORM ACTIVITY LATER THIS AFTERNOON INTO EARLY EVENING...BUT NEW SHOWERS AND STORMS MAY DEVELOP OFFSHORE LATE THIS EVENING AND OVERNIGHT. SEAS CONTINUE TO BE THE ONE AREA WE ARE RECEIVING AN INFLUENCE FROM FORMER TROPICAL STORM ALBERTO. 3-4 FT SEAS WILL CONTINUE INTO TONIGHT AS ALBERTO`S SWELL IS ADDED TO LOCALLY GENERATED WIND WAVES. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...THE BIGGEST THREAT WED AND THU WILL BE ISOLATED TO SCATTERED TSTMS THAT COULD TRACK ACROSS THE WATERS INTACT. THIS WILL INTRODUCE CLOUD TO WATER LIGHTNING STRIKES AND LOCALLY ROUGH CONDITIONS. OUTSIDE OF TSTMS...MAINLY SOUTHERLY WINDS 15 KNOTS OR LESS WED AND THU...WITH A FEW HIGHER AFTERNOON GUSTS ENHANCED BY THE SEA BREEZE CIRCULATION. 3-4 FOOT SEAS WED AND THU COMPRISED OF SE WAVES 2-3 FEET IN 8-10 SECOND INTERVALS AND S WAVES AROUND 2 FEET IN 5-6 SECOND WAVE INTERVALS. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 3 PM TUESDAY...NORTHEAST WINDS FOR THE FIRST COUPLE OF DAYS VEERING TO THE EAST FOR LATE IN THE WEEKEND AS HIGH PRESSURE RESIDES TO THE WEST AND LOW PRESSURE TO THE EAST. LOWER CONFIDENCE IN SPEEDS AS THE LOWS TO THE EAST ARE WILD CARDS. OVERALL EXPECT SPEEDS TO REMAIN BELOW FLAG CRITERIA HOWEVER. EXPECT SUMMER LIKE SEAS OF 2-4 FEET. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...MJC LONG TERM...SHK AVIATION...MRR/TRA
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1242 PM EDT TUE MAY 22 2012 .SYNOPSIS... A SOUTHWESTERLY FLOW OF LOW LEVEL MOISTURE WILL REMAIN IN PLACE OVER THE NEXT FEW DAYS WHILE AN UPPER LEVEL DISTURBANCE TRIGGERS THUNDERSTORMS THIS AFTERNOON THROUGH THURSDAY. AS THIS SYSTEM EXITS...A WARMUP IS EXPECTED LATE IN THE WEEK AND THROUGH THE HOLIDAY WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1245 PM TUESDAY...RADAR SHOWS SHOWERS DEVELOPING ACROSS THE LOWER PEE DEE REGION WITH AN INCOMING VORTICITY LOBE...AND ALSO SOME ACTIVITY ACROSS NORTHERN SECTIONS OF PENDER AND BLADEN COUNTIES. VISIBLE SATELLITE (AND GLANCES OUT THE WINDOW) SHOW THE CUMULUS FIELD IN AND AROUND WILMINGTON IS PRIMED FOR ACTIVITY AS WELL. THIS REQUIRES ONLY SMALL CHANGES TO THE PREVIOUS FORECAST. DISCUSSION FROM 1030 AM FOLLOWS... TROPICAL DEPRESSION ALBERTO IS NO MORE. THE CONVECTION HAS BEEN SHEARED OFF AND AWAY FROM THE LOW-LEVEL CIRCULATION MEANING THERE IS NO LONGER A METHOD FOR ALBERTO TO EVACUATE AIR AND MAINTAIN LOWER PRESSURES IN THE CENTER OF THE CIRCULATION. ALBERTO`S REMNANT CIRCULATION IS CAUGHT UP IN THE SOUTHWEST FLOW AHEAD OF AN INCOMING NEGATIVELY TILTED UPPER LEVEL TROUGH THAT WILL MOVE FROM THE ALABAMA/GEORGIA BORDER THIS MORNING INTO SOUTH CAROLINA TONIGHT. THE NEGATIVE TILT SHOULD BECOME SO EXTREME TONIGHT THE SYSTEM ACTUALLY WILL CUT OFF INTO A CLOSED UPPER LOW WHICH SHOULD WOBBLE SLOWLY OVERHEAD WEDNESDAY. FALLING MID-LEVEL TEMPERATURES AND A JUICY SUBTROPICAL AIRMASS HERE AT THE SURFACE SPELL GROWING VERTICAL INSTABILITY...WITH CAPE VALUES RISING TO AROUND 1500 J/KG THIS AFTERNOON. WITH THE HELP OF MESOSCALE LIFT PROVIDED BY THE SEABREEZE FRONT...SHOWERS AND THUNDERSTORMS SHOULD DEVELOP EARLY THIS AFTERNOON JUST INLAND FROM THE COAST. THE ONLY AREAS THAT MIGHT BE COMPLETELY SPARED ARE THE SOUTH-FACING BEACHES WHERE COOLER ONSHORE WINDS BEHIND THE SEABREEZE WILL DEVELOP EARLY ENOUGH THIS AFTERNOON. THE LATEST HRRR SHOWS THIS CLASSIC WEATHER PATTERN WELL AND IS THE BASIS FOR OUR MORNING FORECAST UPDATE. BY MID TO LATE AFTERNOON CONTINUED HEATING INLAND AND THE APPROACH OF THE SURFACE COLD FRONT SHOULD PRODUCE SCATTERED SHOWERS AND STORMS INLAND AS WELL. SPC HAS CENTRAL SOUTH CAROLINA OUTLOOKED IN A "SLIGHT RISK" FOR SEVERE WEATHER WITH THE COLDER TEMPERATURES ALOFT AND BETTER SHEAR PROFILES CLOSER TO THE NEGATIVELY TILTED UPPER TROUGH. CONVECTIVE ACTIVITY MAY LINGER INTO THE EVENING...WITH PERHAPS A SECOND ROUND OF SHOWERS AND STORMS OVERNIGHT AS THE CORE OF THE COLDEST TEMPERATURES ALOFT ROTATE INTO EASTERN SOUTH CAROLINA. HIGHS TODAY SHOULD REACH THE MID 80S AWAY FROM THE OCEAN. LOWS TONIGHT SHOULD FALL TO 65-70...WARMEST AT THE BEACHES. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 AM TUESDAY...COOL POCKET ALOFT ASSOCIATED WITH MID LEVEL TROUGH MOVES ACROSS WEDNESDAY MORNING. THEREAFTER COMES WEAK HEIGHT RISES AND WAA BUT A TRAILING VORT MAX SHOULD STILL MANAGE TO TOUCH OFF SCATTERED AFTERNOON THUNDERSTORMS. FORECAST INSTABILITY AMPLE ENOUGH TO DRAW ANOTHER SEE TEXT/5% FOR SEVERE FROM SPC...NOTING LACK OF SHEAR TO SUPPORT ANY LEVEL OF ORGANIZATION IN CONVECTION. TEMPERATURES WILL BE VERY CLOSE TO CLIMO. FORCING WILL BE ON THE WANE FOR THE REMAINDER OF THE PERIOD WITH THE EXIT OF THE UPPER TROUGH. YET ANOTHER VORT COMES THROUGH ON THE HEELS OF THE EXITING TROUGH THURSDAY AFTERNOON. ITS A MUCH WEAKER FEATURE SO ONLY LOW END CHANCE POPS APPEAR WARRANTED FOR WHAT SHOULD END UP BEING WIDELY SCATTERED OR ISOLATED CONVECTIVE COVERAGE. THURSDAY HIGHS AND LOWS WILL BE VERY CLOSE TO WEDNESDAYS AND THUS CLIMATOLOGY. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 3 AM TUESDAY...UPPER WAVE FROM THE SHORT TERM GOES ON TO INTERACT WITH AMPLE MOISTURE STREAMING OUT OF THE CARIBBEAN AND GUIDANCE SUGGESTS LOW PRESSURE GETS INDUCED IN THE BAHAMAS LATER IN THE PERIOD. WRF SOLUTION APPEARS RATHER CLIMATOLOGICALLY EXTREME AT THIS POINT BUT GIVEN THAT SSTS WERE WARM ENOUGH TO ALREADY SUPPORT ALBERTO TOUGH TO RULE OUT. FOR NOW THE SHALLOWER SYSTEM DEPICTED BY THE GFS SEEMS MORE APPEALING AND THERE WILL BE NO IMPACT LOCALLY ON FRIDAY AS UPPER RIDGE BUILDS OVER GULF STATES. JUST ISOLATED CONVECTION AS NORTHERLY FLOW LOCALLY WILL CONTAIN SOME WEAK SHORT WAVE IMPULSES AND A HEALTHY SEA BREEZE CIRCULATION WILL DEVELOP. NOT MUCH CHANGES INTO THE HOLIDAY WEEKEND AND WITH THE AFOREMENTIONED POSSIBLE LOW OUT OF THE PICTURE THE UPPER RIDGE WILL BE THE DOMINANT PLAYER. TEMPERATURES WILL RISE ABOVE CLIMATOLOGY. SURFACE FLOW WILL BE A BIT MORE EASTERLY THAN MOST LATE SPRING WARM UPS TEMPERING THE WARMTH SLIGHTLY AND PUSHING THE SEA BREEZE WELL INLAND. ISOLATED CONVECTION EACH AFTERNOON MAY BE SHUNTED ALL THE WAY TO WESTERN ZONES. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 18Z...SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP THIS AFTERNOON AHEAD OF AN APPROACHING COLD FRONT AND UPPER IMPULSE. CONFIDENCE IN TIMING OF ACTIVITY INTO ANY TERMINAL IS ONLY LOW TO MODERATE. ONE IMPULSE MOVING THROUGH THE FLO TERMINALS ATTM SHOULD ENHANCE SEA BREEZE ACTIVITY FOR SEVERAL HOURS THIS AFTERNOON FROM MYR TO ILM. WILL INDICATE SHOWERS/WITH TEMPO MVFR AT ALL TERMINALS THIS AFTERNOON...WITH SHORT-TERM AMENDMENTS AS RADAR COVERAGE INDICATES. VCTS WILL BE MOST LIKELY AT THE COASTAL TERMINALS. SHORT PERIODS OF IFR ARE LIKELY WITH ANY THUNDERSTORMS BUT THE DURATION SHOULD BE TOO SHORT TO MENTION IN AT LEAST THE 18Z TAFS. THIS CONVECTION SHOULD END BY LATE AFTERNOON...WITH A SECOND ROUND OF CONVECTION DEVELOPING THIS EVENING PERSISTING UNTIL MIDNIGHT OR EVEN AFTER AS THE UPPER IMPULSE ROTATES THROUGH. THUNDERSTORM DEBRIS CLOUDINESS SHOULD SLOWLY THIS OUT AFTER THE PRECIPITATION ENDS AFTER MIDNIGHT...LEAVING THE WINDOW OPEN FOR BR DEVELOPMENT. ATTM WILL INDICATE ONLY MVFR CONDITIONS AT FLO/LBT DUE TO LIGHTER SURFACE WINDS AND LESS POTENTIAL CLOUD COVER. PATCHY DENSE FOG COULD OCCUR ESPECIALLY IN SHELTERED AREAS WHERE SKIES CLEAR OUT. ANY REDUCED FLIGHT CONDITIONS SHOULD IMPROVE RAPIDLY AROUND SUNRISE WITH SHOWERS AND THUNDERSTORMS AGAIN POSSIBLE BY MID MORNING. EXTENDED OUTLOOK...SCATTERED SHOWERS/MVFR...WITH ISOLATED THUNDERSTORMS/TEMPO IFR POSSIBLE THROUGH THE EXTENDED PERIOD. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1245 PM TUESDAY...CURRENT OBSERVATIONS MATCH THE PREVIOUS FORECAST CLOSELY...NO CHANGES ARE REQUIRED. PREVIOUS DISCUSSION FROM 1030 AM FOLLOWS... ALBERTO IS A DISSIPATING POST-TROPICAL DEPRESSION LOCATED ABOUT 250 MILES EAST-SOUTHEAST OF CAPE FEAR. WINDS ARE CURRENTLY SOUTH TO SOUTHWEST ACROSS OUR COASTAL WATERS INDICATING THERE HAS BEEN NO INFLUENCE FROM ALBERTO`S SMALL CIRCULATION. OUR WINDS ARE ACTUALLY INFLUENCED BY THE CYCLONIC FLOW AROUND AN AREA OF LOW PRESSURE AND COLD FRONT CURRENTLY ACROSS THE INLAND CAROLINAS. THIS SYSTEM IS NOT EXPECTED TO REACH THE COAST... INSTEAD STALLING TONIGHT AND DISSIPATING ON WEDNESDAY. UNTIL THEN... SOUTHWEST 10-15 KNOT WINDS ARE EXPECTED...STRONGEST ALONG THE COAST THIS AFTERNOON AND FARTHER AWAY FROM THE COAST TONIGHT. THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE SEABREEZE FRONT THIS AFTERNOON. SOME OF THESE COULD BE ON OR VERY NEAR THE BEACHES...SO MARINERS WILL WANT TO PAY CLOSE ATTENTION TO THE SKY EARLY THIS AFTERNOON. THERE SHOULD BE A LULL IN SHOWER/T-STORM ACTIVITY LATER THIS AFTERNOON INTO EARLY EVENING...BUT NEW SHOWERS AND STORMS MAY DEVELOP OFFSHORE LATE THIS EVENING AND OVERNIGHT. SEAS CONTINUE TO BE THE ONE AREA WE ARE RECEIVING AN INFLUENCE FROM FORMER TROPICAL STORM ALBERTO. 3-4 FT SEAS WILL CONTINUE INTO TONIGHT AS ALBERTO`S SWELL IS ADDED TO LOCALLY GENERATED WIND WAVES. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 AM TUESDAY...BROAD AND WEAK HIGH PRESSURE ACROSS THE WESTERN ATLANTIC IN TANDEM WITH PIEDMONT TROUGHINESS TO BRING SSW FLOW ON WEDNESDAY. A DOMINANT 3 TO 4 FT SEA STATE WILL BE A COMBO OF SW WIND CHOP AND E SWELL...BOTH COMPONENTS BEING COMPARABLE IN RELATIVE STRENGTH. CONDITIONS WILL NOT CHANCE TOO MUCH INTO THURSDAY BUT THEIR IS SOME UNCERTAINTY. LOW PRESSURE WILL MOVE OUT OF THE CARIBBEAN AND INTO THE BAHAMAS LATE IN THE PERIOD. THERE IS QUITE A DIFFERENCE IN GUIDANCE WITH RESPECT TO THIS SYSTEMS EVENTUAL FATE. FOR THIS PERIOD ITS PRESENCE MAY CUT DOWN ON THE SWELL ENERGY BY INTERRUPTING THE LONG EASTERLY FETCH. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 3 AM TUESDAY...FOR THE MOST PART A LARGE AREA OF HIGH PRESSURE ACROSS THE WESTERN ATLANTIC WILL BE RESPONSIBLE FOR THE LOCAL SET OF WIND AND WAVES. THERE IS A COMPLICATING FACTOR THAT FRIDAY MAY SEE SOME KIND OF WEAK LOW OF TROPICAL ORIGINS MOVING PARALLEL TO THE COAST...AND LIKELY WELL OFFSHORE. THERE ARE SOME MODEL SOLUTIONS THAT HAVE IT CLOSER AND STRONGER AND THEREFORE MUCH OF A FACTOR IN THE FORECAST. FOR NOW FOLLOWING WEAKER SOLUTIONS THAT SHOW A WEAK LOW OR OPEN TROUGH IN THE OTHERWISE EASTERLY FLOW BORNE OF AFOREMENTIONED HIGH. SEAS IN THE 2 TO 4 FT RANGE AS ALTHOUGH WINDS WILL REMAIN LIGHT THE EASTERLY FETCH LENGTH COULD BE QUITE LONG AND ALLOW FOR A SIGNIFICANT SWELL COMPONENT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...MBB LONG TERM...MBB AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1047 AM EDT TUE MAY 22 2012 .SYNOPSIS... A SOUTHWESTERLY FLOW OF LOW LEVEL MOISTURE WILL REMAIN IN PLACE OVER THE NEXT FEW DAYS WHILE AN UPPER LEVEL DISTURBANCE TRIGGERS THUNDERSTORMS THIS AFTERNOON THROUGH THURSDAY. AS THIS SYSTEM EXITS...A WARMUP IS EXPECTED LATE IN THE WEEK AND THROUGH THE HOLIDAY WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM TUESDAY...TROPICAL DEPRESSION ALBERTO IS NO MORE. THE CONVECTION HAS BEEN SHEARED OFF AND AWAY FROM THE LOW-LEVEL CIRCULATION MEANING THERE IS NO LONGER A METHOD FOR ALBERTO TO EVACUATE AIR AND MAINTAIN LOWER PRESSURES IN THE CENTER OF THE CIRCULATION. ALBERTO`S REMNANT CIRCULATION IS CAUGHT UP IN THE SOUTHWEST FLOW AHEAD OF AN INCOMING NEGATIVELY TILTED UPPER LEVEL TROUGH THAT WILL MOVE FROM THE ALABAMA/GEORGIA BORDER THIS MORNING INTO SOUTH CAROLINA TONIGHT. THE NEGATIVE TILT SHOULD BECOME SO EXTREME TONIGHT THE SYSTEM ACTUALLY WILL CUT OFF INTO A CLOSED UPPER LOW WHICH SHOULD WOBBLE SLOWLY OVERHEAD WEDNESDAY. FALLING MID-LEVEL TEMPERATURES AND A JUICY SUBTROPICAL AIRMASS HERE AT THE SURFACE SPELL GROWING VERTICAL INSTABILITY...WITH CAPE VALUES RISING TO AROUND 1500 J/KG THIS AFTERNOON. WITH THE HELP OF MESOSCALE LIFT PROVIDED BY THE SEABREEZE FRONT...SHOWERS AND THUNDERSTORMS SHOULD DEVELOP EARLY THIS AFTERNOON JUST INLAND FROM THE COAST. THE ONLY AREAS THAT MIGHT BE COMPLETELY SPARED ARE THE SOUTH-FACING BEACHES WHERE COOLER ONSHORE WINDS BEHIND THE SEABREEZE WILL DEVELOP EARLY ENOUGH THIS AFTERNOON. THE LATEST HRRR SHOWS THIS CLASSIC WEATHER PATTERN WELL AND IS THE BASIS FOR OUR MORNING FORECAST UPDATE. BY MID TO LATE AFTERNOON CONTINUED HEATING INLAND AND THE APPROACH OF THE SURFACE COLD FRONT SHOULD PRODUCE SCATTERED SHOWERS AND STORMS INLAND AS WELL. SPC HAS CENTRAL SOUTH CAROLINA OUTLOOKED IN A "SLIGHT RISK" FOR SEVERE WEATHER WITH THE COLDER TEMPERATURES ALOFT AND BETTER SHEAR PROFILES CLOSER TO THE NEGATIVELY TILTED UPPER TROUGH. CONVECTIVE ACTIVITY MAY LINGER INTO THE EVENING...WITH PERHAPS A SECOND ROUND OF SHOWERS AND STORMS OVERNIGHT AS THE CORE OF THE COLDEST TEMPERATURES ALOFT ROTATE INTO EASTERN SOUTH CAROLINA. HIGHS TODAY SHOULD REACH THE MID 80S AWAY FROM THE OCEAN. LOWS TONIGHT SHOULD FALL TO 65-70...WARMEST AT THE BEACHES. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 AM TUESDAY...COOL POCKET ALOFT ASSOCIATED WITH MID LEVEL TROUGH MOVES ACROSS WEDNESDAY MORNING. THEREAFTER COMES WEAK HEIGHT RISES AND WAA BUT A TRAILING VORT MAX SHOULD STILL MANAGE TO TOUCH OFF SCATTERED AFTERNOON THUNDERSTORMS. FORECAST INSTABILITY AMPLE ENOUGH TO DRAW ANOTHER SEE TEXT/5% FOR SEVERE FROM SPC...NOTING LACK OF SHEAR TO SUPPORT ANY LEVEL OF ORGANIZATION IN CONVECTION. TEMPERATURES WILL BE VERY CLOSE TO CLIMO. FORCING WILL BE ON THE WANE FOR THE REMAINDER OF THE PERIOD WITH THE EXIT OF THE UPPER TROUGH. YET ANOTHER VORT COMES THROUGH ON THE HEELS OF THE EXITING TROUGH THURSDAY AFTERNOON. ITS A MUCH WEAKER FEATURE SO ONLY LOW END CHANCE POPS APPEAR WARRANTED FOR WHAT SHOULD END UP BEING WIDELY SCATTERED OR ISOLATED CONVECTIVE COVERAGE. THURSDAY HIGHS AND LOWS WILL BE VERY CLOSE TO WEDNESDAYS AND THUS CLIMATOLOGY. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 3 AM TUESDAY...UPPER WAVE FROM THE SHORT TERM GOES ON TO INTERACT WITH AMPLE MOISTURE STREAMING OUT OF THE CARIBBEAN AND GUIDANCE SUGGESTS LOW PRESSURE GETS INDUCED IN THE BAHAMAS LATER IN THE PERIOD. WRF SOLUTION APPEARS RATHER CLIMATOLOGICALLY EXTREME AT THIS POINT BUT GIVEN THAT SSTS WERE WARM ENOUGH TO ALREADY SUPPORT ALBERTO TOUGH TO RULE OUT. FOR NOW THE SHALLOWER SYSTEM DEPICTED BY THE GFS SEEMS MORE APPEALING AND THERE WILL BE NO IMPACT LOCALLY ON FRIDAY AS UPPER RIDGE BUILDS OVER GULF STATES. JUST ISOLATED CONVECTION AS NORTHERLY FLOW LOCALLY WILL CONTAIN SOME WEAK SHORT WAVE IMPULSES AND A HEALTHY SEA BREEZE CIRCULATION WILL DEVELOP. NOT MUCH CHANGES INTO THE HOLIDAY WEEKEND AND WITH THE AFOREMENTIONED POSSIBLE LOW OUT OF THE PICTURE THE UPPER RIDGE WILL BE THE DOMINANT PLAYER. TEMPERATURES WILL RISE ABOVE CLIMATOLOGY. SURFACE FLOW WILL BE A BIT MORE EASTERLY THAN MOST LATE SPRING WARM UPS TEMPERING THE WARMTH SLIGHTLY AND PUSHING THE SEA BREEZE WELL INLAND. ISOLATED CONVECTION EACH AFTERNOON MAY BE SHUNTED ALL THE WAY TO WESTERN ZONES. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... AS OF 12Z...CONFIDENCE IS HIGH THAT LIGHT FOG WILL IMPROVE QUICKLY AS INDICATED IN TAFS. VFR IS THEN EXPECTED THE REMAINDER OF THE MORNING EXCEPT FOR TEMPO MVFR CEILINGS AT THE COASTAL TERMINALS AS THE SEA BREEZE DEVELOPS...AND TEMPO CONDITIONS IN SHOWERS AT FLO/LBT BY LATE MORNING. A COLD FRONT WILL APPROACH FROM THE WEST TODAY BUT IT IS NOT EXPECTED TO MOVE THROUGH THE TERMINALS. AHEAD OF THE FRONT THERE IS MODERATE TO HIGH CONFIDENCE SHOWERS AND THUNDERSTORMS WILL DEVELOP. CONVECTION WILL AFFECT THE FLO/LBT TERMINALS AS EARLY AS 15-17Z AND THE COASTAL TERMINALS BY 17-19Z. ATTM WILL INDICATE SHOWERS WITH TEMPO MVFR AND VCTS...ALTHOUGH VCTS MAY BE MORE LIKELY AT THE COASTAL TERMINALS THAN AT FLO/LBT. SHORT PERIODS OF IFR ARE LIKELY WITH THE THUNDERSTORMS BUT THE DURATION SHOULD BE TOO SHORT TO MENTION IN TAFS. A SECOND ROUND OF ACTIVITY IS POSSIBLE LATE THIS AFTERNOON AT FLO/LBT AND THIS EVENING AT THE COASTAL TERMINALS AS THE UPPER IMPULSE ROTATES THROUGH. THUNDERSTORM DEBRIS CLOUDINESS SHOULD SLOWLY SCATTER OUT OVERNIGHT LEAVING THE WINDOW OPEN FOR BR DEVELOPMENT. ATTM WILL INDICATE ONLY MVFR CONDITIONS AT FLO/LBT DUE TO LIGHTER SURFACE WINDS AND LESS POTENTIAL CLOUD COVER. PATCHY DENSE FOG COULD OCCUR ESPECIALLY IN SHELTERED AREAS WHERE SKIES CLEAR OUT. EXTENDED OUTLOOK...SCATTERED SHOWERS/MVFR...WITH ISOLATED THUNDERSTORMS/TEMPO IFR POSSIBLE THROUGH THE EXTENDED PERIOD. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM TUESDAY...ALBERTO IS A DISSIPATING POST-TROPICAL DEPRESSION LOCATED ABOUT 250 MILES EAST-SOUTHEAST OF CAPE FEAR. WINDS ARE CURRENTLY SOUTH TO SOUTHWEST ACROSS OUR COASTAL WATERS INDICATING THERE HAS BEEN NO INFLUENCE FROM ALBERTO`S SMALL CIRCULATION. OUR WINDS ARE ACTUALLY INFLUENCED BY THE CYCLONIC FLOW AROUND AN AREA OF LOW PRESSURE AND COLD FRONT CURRENTLY ACROSS THE INLAND CAROLINAS. THIS SYSTEM IS NOT EXPECTED TO REACH THE COAST... INSTEAD STALLING TONIGHT AND DISSIPATING ON WEDNESDAY. UNTIL THEN... SOUTHWEST 10-15 KNOT WINDS ARE EXPECTED...STRONGEST ALONG THE COAST THIS AFTERNOON AND FARTHER AWAY FROM THE COAST TONIGHT. THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE SEABREEZE FRONT THIS AFTERNOON. SOME OF THESE COULD BE ON OR VERY NEAR THE BEACHES...SO MARINERS WILL WANT TO PAY CLOSE ATTENTION TO THE SKY EARLY THIS AFTERNOON. THERE SHOULD BE A LULL IN SHOWER/T-STORM ACTIVITY LATER THIS AFTERNOON INTO EARLY EVENING...BUT NEW SHOWERS AND STORMS MAY DEVELOP OFFSHORE LATE THIS EVENING AND OVERNIGHT. SEAS CONTINUE TO BE THE ONE AREA WE ARE RECEIVING AN INFLUENCE FROM FORMER TROPICAL STORM ALBERTO. 3-4 FT SEAS WILL CONTINUE INTO TONIGHT AS ALBERTO`S SWELL IS ADDED TO LOCALLY GENERATED WIND WAVES. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 AM TUESDAY...BROAD AND WEAK HIGH PRESSURE ACROSS THE WESTERN ATLANTIC IN TANDEM WITH PIEDMONT TROUGHINESS TO BRING SSW FLOW ON WEDNESDAY. A DOMINANT 3 TO 4 FT SEA STATE WILL BE A COMBO OF SW WIND CHOP AND E SWELL...BOTH COMPONENTS BEING COMPARABLE IN RELATIVE STRENGTH. CONDITIONS WILL NOT CHANCE TOO MUCH INTO THURSDAY BUT THEIR IS SOME UNCERTAINTY. LOW PRESSURE WILL MOVE OUT OF THE CARIBBEAN AND INTO THE BAHAMAS LATE IN THE PERIOD. THERE IS QUITE A DIFFERENCE IN GUIDANCE WITH RESPECT TO THIS SYSTEMS EVENTUAL FATE. FOR THIS PERIOD ITS PRESENCE MAY CUT DOWN ON THE SWELL ENERGY BY INTERRUPTING THE LONG EASTERLY FETCH. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 3 AM TUESDAY...FOR THE MOST PART A LARGE AREA OF HIGH PRESSURE ACROSS THE WESTERN ATLANTIC WILL BE RESPONSIBLE FOR THE LOCAL SET OF WIND AND WAVES. THERE IS A COMPLICATING FACTOR THAT FRIDAY MAY SEE SOME KIND OF WEAK LOW OF TROPICAL ORIGINS MOVING PARALLEL TO THE COAST...AND LIKELY WELL OFFSHORE. THERE ARE SOME MODEL SOLUTIONS THAT HAVE IT CLOSER AND STRONGER AND THEREFORE MUCH OF A FACTOR IN THE FORECAST. FOR NOW FOLLOWING WEAKER SOLUTIONS THAT SHOW A WEAK LOW OR OPEN TROUGH IN THE OTHERWISE EASTERLY FLOW BORNE OF AFOREMENTIONED HIGH. SEAS IN THE 2 TO 4 FT RANGE AS ALTHOUGH WINDS WILL REMAIN LIGHT THE EASTERLY FETCH LENGTH COULD BE QUITE LONG AND ALLOW FOR A SIGNIFICANT SWELL COMPONENT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...MBB LONG TERM...MBB AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
139 AM EDT TUE MAY 22 2012 .SYNOPSIS... ALBERTO WILL ACCELERATE OUT TO THE NORTHEAST THROUGH TUESDAY... MOVING FARTHER AWAY FROM THE U.S. MAINLAND. A WEAK COLD FRONT WILL SNAKE TO THE EAST AND STALL NEAR OR WEST OF THE FORECAST AREA TUESDAY NIGHT AND SLOWLY DISSIPATE WEDNESDAY OR THURSDAY. HIGH PRESSURE WILL EVOLVE ACROSS THE WESTERN ATLANTIC LATE IN THE WEEK AND RIDGE ACROSS THE REGION THROUGH THE WEEKEND...BRINGING SUMMER LIKE CONDITIONS. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 1010 PM MONDAY...THE DIURNALLY DRIVEN ISOLATED CONVECTION THIS EVENING IS NEARLY OVERWITH...AND SHOULD BE A MEMORY BY LATE THIS EVENING AS THE SEA BREEZE BOUNDARY HAVING TRACKED WELL INLAND... LOSES ITS LIFTING CAPABILITIES. THIS WILL LEAVE A MOSTLY CLEAR SKY FOR THE OVERNIGHT...WITH SOME INCREASE OF MOISTURE WEST OF THE I-95 CORRIDOR TOWARDS TUESDAY DAYBREAK. HAVE KEPT POPS NULL AND VOID FROM LATE THIS EVENING UNTIL THE START OF THE SHORT TERM WHEN LIFT AHEAD OF THE COLD FRONT BECOMES APPARENT. AS FOR MIN TEMPS...SLIGHT ADJUSTMENTS MAY BE NEEDED UPWARD TO ACCOUNT FOR THE WIDESPREAD LOW TO MID 60S DEWPOINTS OVERNIGHT. PATCHY TO AREAS OF FOG WILL BE POSSIBLE GIVEN THE DECENT RAD CONDITIONS...DECOUPLING OF THE WINDS...AND AVAILABLE LOW LEVEL MOISTURE. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...UNSETTLED WEATHER THROUGH THE PERIOD AS AN UPPER TROUGH DROPS IN FROM THE NORTHWEST TUE THEN BECOMES SEMI-CUTOFF OVER THE AREA WED. LOOKS LIKE BOTH TUE AND WED WILL BE ACTIVE AS FAR AS CONVECTION IS CONCERNED. HIGH WILL BE SIMILAR BOTH DAYS...LOW TO MID 80S...WITH DEWPOINT IN THE LOW TO MID 60S. UPPER TROUGH/LOW AND ASSOCIATED COLD AIR ALOFT COMBINED WITH DIURNAL HEATING...60 DEGREE DEWPOINTS...CONVERGENCE ALONG THE SEABREEZE WILL PRODUCE CONVECTION EACH DAY. COVERAGE WISE WED HAD LOOKED A LITTLE MORE FAVORABLE BUT LATEST GUIDANCE HAS BACKED OFF A BIT ON THE DEEPER MOISTURE. NOW BOTH DAYS APPEAR SIMILAR WITH RESPECT TO BOTH PRECIP COVERAGE AND INTENSITY...CARRYING 40-50 POP BOTH DAYS. SBCAPE VALUES ARE IN THE 1000-1500 J/KG RANGE WITH VERTICAL PROFILES SUGGESTING A FEW STRONG TO POTENTIALLY SEVERE PULSE STORMS COULD DEVELOP. SPC MAINTAINS THE SEE TEXT FOR TUE AND WITH A SIMILAR ENVIRONMENT EXPECTED ON WED WOULD NOT BE SHOCKED IF A SEE TEXT WERE ISSUED FOR WED AT SOME POINT...ESPECIALLY WITH THE COLDEST CORE ALOFT DIRECTLY OVERHEAD...THOUGH IT WILL BE MODIFYING. PREVIOUS FORECAST CARRIED CHANCE POP FOR TUE NIGHT...AND GIVEN THE UPPER TROUGH/LOW OVERHEAD WOULD EXPECT CONVECTION TO CONTINUE INTO THE EARLY MORNING HOURS. WED NIGHT THINGS START TO DRY OUT AS THE UPPER LOW LIFTS NORTH AND DRIER AIR STARTS TO INFILTRATE FROM THE SOUTHWEST. OVERNIGHT LOWS WILL RUN IN THE LOW TO MID 60S. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 300 PM MONDAY...THE SOUTHERLY RETURN FLOW INITIALLY AROUND BERMUDA HIGH WILL BE REPLACED BY A NORTHEAST FLOW AS HIGH PRESSURE RIDGES DOWN FROM CANADA BY SAT. OVERALL THE SURFACE FLOW WILL BE DOMINATED MORE BY LAND/SEA BREEZE THROUGH MOST OF THE LONG TERM AS PRESSURE PATTERN REMAINS WEAK. EXPECT DEEP S-SW FLOW RETURN FLOW ON THURS AS MID TO UPPER TROUGH CONTINUES TO DIG DOWN TO OUR WEST AND BERMUDA HIGH RIDGES IN FROM THE ATLANTIC. THE H5 TROUGH AXIS SHOULD MOVE OFF SHORE THURS NIGHT WITH A DEEPER NE FLOW DEVELOPING AS UPPER RIDGE BUILDS INTO THE CAROLINAS FROM THE WEST THROUGH THE WEEKEND. ENERGY FROM THIS H5 SHORTWAVE MAY PROVIDE SOME ENHANCEMENT TO LOCALIZED CONVECTION THURS AFTERNOON BUT WE WILL ACTUALLY GET SOME DRIER AIR MOVING IN FROM THE SW IN THE MID LEVELS COMING AROUND THE BASE OF THE TROUGH ON THURS. THIS SHOULD HELP TO INHIBIT ANY STRONG CONVECTION BUT WILL KEEP ISOLATED SHWRS IN THE FORECAST MAINLY LATE DAY THURS INTO THURS NIGHT BEFORE SHORTWAVE LIFTS OFF TO THE NORTHEAST. EXPECT PLENTY OF SUBSIDENCE ON BACK END OF TROUGH AS RIDGE BUILDS IN LATE FRI THROUGH THE WEEKEND. HEIGHTS INCREASE CLOSE TO 590 DEM OVER THE WEEKEND AS RIDGE BUILDS TO OUR WEST. OVERALL EXPECT ONLY LOCALIZED CONVECTION POSSIBLE ALONG SEA BREEZE WITH A SUMMER-LIKE AIR MASS IN PLACE. DEWPOINTS WILL BE IN THE MID 60S THROUGH THE WEEKEND. A WAVE OF LOW PRESSURE MAY MOVE INTO THE CAROLINAS SUN NIGHT INTO MONDAY WHICH MAY PRODUCE A BETTER CHC OF PCP TOWARD THE END OF THE MEMORIAL DAY WEEKEND WITH A STRONGER ON SHORE FLOW. TEMPS SHOULD RUN ABOVE NORMAL THROUGH THE EXTENDED PERIOD AS RIDGE BUILDS AND HEIGHTS RISE. EXPECT LESS OF A DIURNAL TREND AS A MORE HUMID AIR MASS WILL REMAIN IN PLACE. OVERALL 80S DURING THE DAY AND 60S AT NIGHT. TEMPS SHOULD BE HIGHEST ON SUNDAY AS HEIGHTS PEAK OVER LOCAL AREA NEAR 590 DEM. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... AS OF 06Z...EXPECT VFR THROUGH THE EARLY OVERNIGHT HOURS...WITH PATCHY DENSE FOG CREATING MVFR/POTENTIAL IFR LATE OVERNIGHT INTO THE EARLY MORNING HOURS. VFR WILL PREVAIL BY MORNING...WITH POTENTIAL FOR BRIEF MVFR IN AFTERNOON VCSH. FEW/SCT MID TO HIGH LEVEL CLOUDS WILL LINGER THROUGH THE OVERNIGHT HOURS...WITH LIGHT AND VARIABLE WINDS. GIVEN AVAILABLE LOW LEVEL MOISTURE...LIGHT WINDS AND SOMEWHAT MODERATE RADIATIONAL COOLING CONDITIONS...EXPECT PATCHY DENSE FOG LATE OVERNIGHT INTO THE EARLY MORNING HOURS. FOR NOW HAVE KEPT RESTRICTIONS AT MVFR...BUT CANNOT RULE OUT VISIBILITIES BEING REDUCED EVEN MORE CREATING IFR CONDITIONS...ESPECIALLY ALONG THE COAST. AFTER DAYBREAK...ANY LINGERING FOG WILL QUICKLY BURN OFF AND POSSIBLY WILL SEE SCT LOWERED CLOUD HEIGHTS. VFR WILL PREVAIL WITH LIGHT WEST WINDS WHICH WILL GRADUALLY BACK TO THE SOUTH-SOUTHWEST. BY THE AFTERNOON HOURS...SUSTAINED WINDS WILL BE AOB 12 KTS. FOR LATE MORNING THROUGH THE END OF THE VALID PERIOD...WILL HAVE CHANCE FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. FOR NOW HAVE KEPT IN VCSH. CANNOT RULE OUT BRIEF MVFR IN HEAVIER DOWNPOURS. AFTER SUNSET...WINDS WILL BECOME LIGHT WITH BKN CLOUD COVER. EXTENDED OUTLOOK...SCATTERED SHOWERS CREATING MVFR...WITH ISOLATED THUNDERSTORMS CREATING TEMPO IFR POSSIBLE THROUGH THE EXTENDED PERIOD. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1010 PM MONDAY...ALBERTO IS ON THE MOVE...BUT FORTUNATELY TOWARD THE EAST NORTHEAST TAKING IT WELL OFFSHORE FROM THE SOUTHEAST U.S. COAST TONIGHT THROUGH TUESDAY. THE LATEST HRRR HAS FINALLY CAUGHT UP WITH THE GENERAL CONSENSUS OF PUSHING IT FURTHER AWAY FROM THE MAINLAND. LOOK FOR VEERING WIND DIRECTIONS OVERNIGHT FROM NE-E TO W-NW BY DAYBREAK TUESDAY. WIND SPEEDS...5 TO 10 KT. SIGNIFICANT SEAS WILL RUN AROUND 3 FT THIS EVENING. WAVEWATCH3 AND SWAN INDICATE AN ESE 4 TO 5 FT WAVE TRAIN WITH PERIODS 9-10 SECONDS WILL AFFECT THE ILM WATERS DURING THE PRE-DAWN HOURS OF TUESDAY AND THERE-AFTER. WILL INDICATE CURRENT SIGNIFICANT SEAS OF 2 TO 3 FT... BUILDING TO 3 TO 4 FT OVERNIGHT INTO TUESDAY. THE OUTER WATERS FROM CAPE FEAR NORTHWARD COULD OBSERVE 5 FOOTERS FROM THIS TRAIN. THE SHADOW CREATED BY FPS WITH AN EASTERLY SWELL...WILL KEEP SEAS CLOSER TO 2 FT ACROSS THE WATERS OFF BRUNSWICK COUNTY. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 2 PM MONDAY...SOUTH TO SOUTHWEST FLOW WILL DOMINATE THE PERIOD. SWELL FROM ALBERTO WILL AFFECT THE WATERS TUE INTO WED. WIND SPEEDS WILL BE 10 TO 15 KT FOR THE MAJORITY OF THE PERIOD... SLIGHTLY LESS AT NIGHT...WITH SOME NEAR SHORE ENHANCEMENT EACH DAY AS THE SEABREEZE DEVELOPS. SEAS WILL BE A COMBINATION OF SOUTHERLY WIND WAVE AND SOUTHEAST TO EAST ALBERTO SWELL...RUNNING 3 TO 4 FT BOTH TUE AND WED. LONG TERM /THURSDAY THROUGH SATURDAY/... AS OF 3 PM MONDAY...SOUTHERLY RETURN FLOW ON THURS AROUND BERMUDA HIGH WILL BE REPLACED BY A N-NE FLOW THROUGH LATE FRI AS HIGH PRESSURE BUILDS DOWN FROM CANADA. WINDS NEAR SHORE WILL BE DRIVEN BY LAND/SEA BREEZE AS OVERALL PRESSURE PATTERN REMAINS MORE ON THE WEAK SIDE. WINDS GENERALLY LESS THAN 15 KTS THURS AND FRI MAY INCREASE THROUGH THE LATTER HALF OF THE WEEKEND AS A WAVE OF LOW PRESSURE MOVES WESTWARD FROM THE OFF SHORE ATLANTIC WATERS TOWARD THE LOCAL WATERS. SEAS WILL BE REMAIN 2 TO 3 FT THROUGH MOST OF THE PERIOD BUT MAY INCREASE WITH A STRONG ON SHORE PUSH BY LATE IN THE WEEKEND AS WAVE OF LOW PRESSURE MIGRATES WESTWARD TOWARD LOCAL WATERS. SEAS WILL MIX WITH A DECREASING EASTERLY SWELL AROUND 9 SECONDS ON THURS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...DCH SHORT TERM...III LONG TERM...RGZ AVIATION...SGL/RJD
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1241 AM EDT TUE MAY 22 2012 .SYNOPSIS... A COLD FRONT WILL MOVE OUT OF THE AREA THIS EVENING. HIGH PRESSURE WILL GRADUALLY BUILD EAST OVER THE REGION BY WEDNESDAY MORNING. THE HIGH PRESSURE CENTER WILL MOVE TO THE EAST COAST BY WEDNESDAY NIGHT ALLOWING A WARM FRONT TO LIFT NORTH ACROSS THE AREA THURSDAY. A WEAK COLD FRONT WILL APPROACH THE AREA LATE FRIDAY. && .NEAR TERM /THROUGH TODAY/... EXCEPT FOR A CLUSTER OF CONVECTION CENTERED IN WAYNE CO...MUCH OF THE DAYTIME CONVECTION HAD DISSIPATED. A BAND OF SHRA IN THE COOLER AIR OVER THE WESTERN PART OF THE AREA ASSOCIATED WITH THE UPPER TROUGH IS TRYING TO GET GOING BUT WILL HAVE A HARD TIME DUE TO A MORE STABLE AIRMASS IN THAT AREA. WILL KEEP SMALL CHANCE GOING FOR MOST AREAS THROUGH MIDNIGHT THEN BEGIN TO SHIFT CHANCE INTO THE SOUTHEAST HALF OF THE AREA OVER THE COURSE OF THE REST OF THE NIGHT. RUC AND HRRR DISAGREE SO OVERALL CONFIDENCE LOW FOR THE REST OF THE NIGHT BUT DO FEEL ANY NEW ACTIVITY WILL BE LIGHT. REST OF FORECAST SEEMS TO BE ON TRACK SO LITTLE WILL BE CHANGED. && .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... THE FRONT WILL BE JUST TO THE EAST OF THE FORECAST AREA. WITH A FAIR AMOUNT OF MOISTURE...WILL CONTINUE WITH CHANCE POPS INTO THE AFTERNOON...MAINLY IN THE EAST...WITH DECREASING CLOUDS ELSEWHERE. OTHERWISE HIGH PRESSURE BUILDING IN TUESDAY NIGHT AND THE HIGH WILL WEAKEN WEDNESDAY NIGHT. A WARM FRONT WILL MOVE ACROSS THE AREA THURSDAY. ON THE EDGE ABOUT THE THREAT OF PRECIPITATION...ANY QPF WOULD BE VERY LIGHT. JUST WENT WITH 20 POPS AT THE MOMENT AND WILL MONITOR IT CLOSELY. && .LONG TERM /FRIDAY THROUGH MONDAY/... BEGINNING FRIDAY IN THE LONG TERM GFS AND ECMWF SHOWING COLD FRONT APPROACHING THE AREA BUT LOOKS LIKE TEMPS WILL BE QUITE ABOVE NORMAL WITH SHOWERS AND THUNDERSTORMS HOLDING OFF MOVING INTO WESTERN AREAS UNTIL LATE DAY/EVENING...WITH BETTER CHANCES ACROSS THE NORTHERN HALF OF THE AREA FRIDAY NIGHT. THE PATTERN LOOKS TO BE TRICKY GOING INTO THE WEEKEND HOWEVER WITH BOTH MODELS SHOWING THE FRONTAL BOUNDARY ORIENTING ITSELF MORE WEST TO EAST ACROSS THE AREA ON SATURDAY. WITH THE BOUNDARY ACROSS THE AREA THE CHANCES FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE. HOWEVER...GIVEN THIS FAR OUT IN THE EXTENDED MAINLY WENT WITH LOW CHC TO SLGT CHC POPS ON SATURDAY. THERE IS SOME DISCREPANCY WITH HOW STRONG HIGH PRESSURE TO THE NORTH MAY RIDGE INTO THE AREA ON SUNDAY PUSHING THE FRONT FURTHER SOUTH AWAY FROM THE AREA...BUT FOR NOW LEANED TOWARD DRIER CONDITIONS GIVEN LOW CONFIDENCE ON TIMING OF ANY PRECIP. GIVEN MODEL DIFFERENCES IN THE LONG TERM LEANED MORE TOWARD PREVIOUS FORECAST TEMPS OVER SAT AND SUN GIVEN MODEL DIFFERENCES. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... EXPECTING GRADUALLY IMPROVING CONDITIONS FROM WEST TO EAST DURING THE DAY AS COLD FRONT CONTINUES TO MOVE WELL EAST OF THE AREA. HIGH PRESSURE WILL BUILD EAST INTO THE REGION LATER TONIGHT INTO WEDNESDAY. EXPECTING VFR CONDITIONS THROUGH THE LATTER HALF OF THE TAF PERIOD. WINDS ARE EXPECTED TO CONTINUE OUT OF AROUND 350 DEGREES AT 10 TO 15 KNOTS THROUGH THE OVERNIGHT HOURS AND BEGIN TO DIMINISH AFTER SUNRISE. LIGHT WINDS ALREADY BEING REPORTED JUST TO THE WEST AND EXPECT THIS TO GET INTO OUR AREA TODAY. .OUTLOOK...NON-VFR POSSIBLE IN EARLY MORNING FOG/HAZE WEDNESDAY. && .MARINE... QUICK UPDATE NEEDED TO COVER GUSTY WINDS ON THE LAKE. BUOY 45005 WAS REPORTING 20 KNOT WINDS WITH 4 FOOT WAVES. DECIDED TO HOIST SMALL CRAFT ADVISORY FROM CONNEAUT ALL THE WAY TO THE ISLANDS TO COVER THE HIGHER WAVE AND WIND SITUATION. SMALL CRAFT ADVISORY UP UNTIL NOON. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR LEZ142>148. && $$ SYNOPSIS...KIELTYKA NEAR TERM...KIELTYKA SHORT TERM...KIELTYKA LONG TERM...ABE AVIATION...LOMBARDY MARINE...LOMBARDY
AREA FORECAST DISCUSSION...CORRECTED
NWS NORMAN OK
314 PM CDT TUE MAY 22 2012 .DISCUSSION... CONVECTION IS DEVELOPING AGAIN OVER THE HIGH PLAINS OF NEW MEXICO AND IS CURRENTLY MOVING INTO CIMARRON COUNTY OKLAHOMA. SOME RECENT RUNS OF THE LOCAL WRF AND THE HRRR HAVE SUGGESTED ENOUGH POSSIBILITY OF CONVECTION INCREASING AND PERSISTING EAST AND SOUTHEAST INTO WESTERN SECTIONS OF THE CWA THAT HAVE ADDED AN AREA OF ISOLATED STORMS IN THE FIRST PERIOD OUT WEST ALTHOUGH AM LEAVING THE POPS BELOW 20 PERCENT. THE EVENING SHIFT CAN CONTINUE TO MONITOR THE TRENDS AND MAKE UPDATES IF NECESSARY. OTHERWISE... HOT AND GENERALLY DRY WEATHER IS EXPECTED FOR A COUPLE OF DAYS AND A WINDY DAY IS EXPECTED TOMORROW. A WIND ADVISORY MAY BE NECESSARY FOR TOMORROW. SOMEWHAT COOLER TEMPERATURES ARE EXPECTED TOWARD THE WEEKEND ALTHOUGH STILL WARM BY MID-LATE MAY STANDARDS. MEDIUM RANGE MODELS ARE ALL SHOWING PRECIP DEVELOPING ON MONDAY ACROSS THE NORTH AND WEST AHEAD OF A COLD FRONT... SO HAVE INTRODUCED SOME POPS FOR MEMORIAL DAY. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 65 91 68 91 / 0 0 10 10 HOBART OK 65 96 66 93 / 10 10 10 10 WICHITA FALLS TX 66 96 69 96 / 10 10 10 10 GAGE OK 64 94 62 90 / 10 10 10 10 PONCA CITY OK 67 90 69 88 / 0 0 10 10 DURANT OK 66 91 67 86 / 0 0 10 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ CORRECTED PRELIMINARY TEMPS/POPS
AREA FORECAST DISCUSSION
NWS NORMAN OK
1218 PM CDT TUE MAY 22 2012 .AVIATION... ISOLATED CONVECTION PERSISTS THIS AFTERNOON... BUT IS EXPECTED TO REMAIN SOUTH AND SOUTHEAST OF THE TAF SITES... SO NO SIGNIFICANT AVIATION WEATHER CONCERNS ARE EXPECTED TODAY. SOUTH WINDS WILL INCREASE WEDNESDAY MORNING WITH GUSTS NEAR OR ABOVE 30 KNOTS AT MANY OF THE TAF LOCATIONS BY 18Z TOMORROW. && .PREV DISCUSSION... /ISSUED 1109 AM CDT TUE MAY 22 2012/ UPDATE... WILL GO AHEAD AND ADD ISOLATED SHWR/TSTM WORDING ACROSS PORTIONS OF SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS THIS AFTN. THIS ACTIVITY IS ASSOCIATED WITH MCV AND SOME DIFFERENTIAL HEATING BOUNDARIES THAT HAVE DEVELOPED FROM LAST EVENINGS CONVECTIONS ACROSS WEST TEXAS. OTHERWISE... FORECAST IS IN GOOD SHAPE WITH WARM AND BREEZY CONDITIONS EXPECTED THIS AFTN. PREV DISCUSSION... /ISSUED 730 AM CDT TUE MAY 22 2012/ AVIATION... AN ISOLATED SHOWER OR TWO WILL BE POSSIBLE THROUGH MID MORNING...OTHERWISE CLOUDS WILL SLOWLY DISSIPATE DURING THE MORNING. SOUTH TO SOUTHEAST WINDS WILL INCREASE BY MID TO LATE MORNING. PREV DISCUSSION... /ISSUED 418 AM CDT TUE MAY 22 2012/ DISCUSSION... MID-LEVEL NORTHWEST TO WEST FLOW WILL GRADUALLY TRANSITION TO A SOUTHWEST FLOW OVER THE NEXT 48 HOURS AS A BROAD TROUGH TAKES SHAPE OVER THE WESTERN HALF OF THE CONUS. MEANWHILE...CONVECTION ACROSS TEXAS PANHANDLE HAS WEAKENED OVERNIGHT WITH MCV-LIKE FEATURE IN WEAK ECHO RETURNS. TO THE EAST...ISOLATED SHOWERS HAVE BEEN FORMING ACROSS THE WESTERN THIRD OF OKLAHOMA FROM HARPER COUNTY TO KIOWA. NAM12 AND RECENT HRRR RUNS ARE MORE BULLISH WITH THE DEVELOPMENT OF MORE SHOWERS/STORMS BETWEEN 10-15Z ACROSS WESTERN HALF OF FA. WITH RECENT DEVELOPMENT WILL ADD 20-30 POPS ACROSS WESTERN 1/3 OF FA. PRECIP THAT DOES DEVELOP SHOULD GRADUALLY WEAKEN DURING THE MID TO LATE MORNING. AFTERNOON CONVECTION MAY DEVELOP WEST OF THE AREA BUT OVERALL COVERAGE MAY LIMIT CHANCES OF IMPACTING WESTERN OKLAHOMA..SO WILL KEEP POPS RATHER LOW. SOUTH WINDS WILL INCREASE SOME TODAY AND WILL BECOME RATHER GUSTY ON WEDNESDAY AS LOW PRESSURE DEEPENS OVER THE HIGHER TERRAIN. A SHORTWAVE WILL MOVE FROM THE CENTRAL ROCKIES INTO THE UPPER MIDWEST LATE WEDNESDAY INTO THURSDAY. THIS FEATURE WILL HELP PUSH A WEAK SURFACE BOUNDARY INTO NORTHWEST AND WEST CENTRAL OKLAHOMA WEDNESDAY NIGHT/EARLY THURSDAY. RATHER WARM 8H TEMPS AND BETTER FORCING NORTH...SHOULD LIMIT STORM CHANCES WITH THIS BOUNDARY. AN UPPER RIDGE WILL BUILD OVER THE SOUTHEAST GOING INTO THE HOLIDAY WEEKEND...WHILE ANOTHER STORM SYSTEM MOVES ACROSS THE WESTERN THIRD OF THE US. EC MODEL STRONGER WITH WESTERN SYSTEM AND MAY BRING A CHANCE OF STORMS TO WESTERN OKLAHOMA BY SUNDAY...AS IT LIFTS NORTH INTO THE NORTHERN ROCKIES AND PLAINS. OVERALL...THE HOLIDAY WEEKEND APPEARS MAINLY DRY AND VERY WARM/HOT WITH BETTER CHANCES FOR STORMS ACROSS WESTERN OK. MODELS SIGNAL A RETURN TO A NORTHWEST FLOW BY THE MIDDLE OF NEXT WEEK WHICH MAY BRING BETTER CHANCES FOR STORMS DURING THE LAST DAYS OF MAY. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 65 90 67 90 / 10 10 10 10 HOBART OK 64 95 68 93 / 10 10 10 10 WICHITA FALLS TX 66 97 68 95 / 10 10 10 10 GAGE OK 62 93 62 92 / 10 10 10 10 PONCA CITY OK 65 90 68 91 / 10 10 10 10 DURANT OK 65 93 65 87 / 10 0 10 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$
AREA FORECAST DISCUSSION
NWS NORMAN OK
1109 AM CDT TUE MAY 22 2012 .UPDATE... WILL GO AHEAD AND ADD ISOLATED SHWR/TSTM WORDING ACROSS PORTIONS OF SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS THIS AFTN. THIS ACTIVITY IS ASSOCIATED WITH MCV AND SOME DIFFERENTIAL HEATING BOUNDARIES THAT HAVE DEVELOPED FROM LAST EVENINGS CONVECTIONS ACROSS WEST TEXAS. OTHERWISE... FORECAST IS IN GOOD SHAPE WITH WARM AND BREEZY CONDITIONS EXPECTED THIS AFTN. && .PREV DISCUSSION... /ISSUED 730 AM CDT TUE MAY 22 2012/ AVIATION... AN ISOLATED SHOWER OR TWO WILL BE POSSIBLE THROUGH MID MORNING...OTHERWISE CLOUDS WILL SLOWLY DISSIPATE DURING THE MORNING. SOUTH TO SOUTHEAST WINDS WILL INCREASE BY MID TO LATE MORNING. PREV DISCUSSION... /ISSUED 418 AM CDT TUE MAY 22 2012/ DISCUSSION... MID-LEVEL NORTHWEST TO WEST FLOW WILL GRADUALLY TRANSITION TO A SOUTHWEST FLOW OVER THE NEXT 48 HOURS AS A BROAD TROUGH TAKES SHAPE OVER THE WESTERN HALF OF THE CONUS. MEANWHILE...CONVECTION ACROSS TEXAS PANHANDLE HAS WEAKENED OVERNIGHT WITH MCV-LIKE FEATURE IN WEAK ECHO RETURNS. TO THE EAST...ISOLATED SHOWERS HAVE BEEN FORMING ACROSS THE WESTERN THIRD OF OKLAHOMA FROM HARPER COUNTY TO KIOWA. NAM12 AND RECENT HRRR RUNS ARE MORE BULLISH WITH THE DEVELOPMENT OF MORE SHOWERS/STORMS BETWEEN 10-15Z ACROSS WESTERN HALF OF FA. WITH RECENT DEVELOPMENT WILL ADD 20-30 POPS ACROSS WESTERN 1/3 OF FA. PRECIP THAT DOES DEVELOP SHOULD GRADUALLY WEAKEN DURING THE MID TO LATE MORNING. AFTERNOON CONVECTION MAY DEVELOP WEST OF THE AREA BUT OVERALL COVERAGE MAY LIMIT CHANCES OF IMPACTING WESTERN OKLAHOMA..SO WILL KEEP POPS RATHER LOW. SOUTH WINDS WILL INCREASE SOME TODAY AND WILL BECOME RATHER GUSTY ON WEDNESDAY AS LOW PRESSURE DEEPENS OVER THE HIGHER TERRAIN. A SHORTWAVE WILL MOVE FROM THE CENTRAL ROCKIES INTO THE UPPER MIDWEST LATE WEDNESDAY INTO THURSDAY. THIS FEATURE WILL HELP PUSH A WEAK SURFACE BOUNDARY INTO NORTHWEST AND WEST CENTRAL OKLAHOMA WEDNESDAY NIGHT/EARLY THURSDAY. RATHER WARM 8H TEMPS AND BETTER FORCING NORTH...SHOULD LIMIT STORM CHANCES WITH THIS BOUNDARY. AN UPPER RIDGE WILL BUILD OVER THE SOUTHEAST GOING INTO THE HOLIDAY WEEKEND...WHILE ANOTHER STORM SYSTEM MOVES ACROSS THE WESTERN THIRD OF THE US. EC MODEL STRONGER WITH WESTERN SYSTEM AND MAY BRING A CHANCE OF STORMS TO WESTERN OKLAHOMA BY SUNDAY...AS IT LIFTS NORTH INTO THE NORTHERN ROCKIES AND PLAINS. OVERALL...THE HOLIDAY WEEKEND APPEARS MAINLY DRY AND VERY WARM/HOT WITH BETTER CHANCES FOR STORMS ACROSS WESTERN OK. MODELS SIGNAL A RETURN TO A NORTHWEST FLOW BY THE MIDDLE OF NEXT WEEK WHICH MAY BRING BETTER CHANCES FOR STORMS DURING THE LAST DAYS OF MAY. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 85 65 90 67 / 10 10 10 10 HOBART OK 89 64 95 68 / 10 10 10 10 WICHITA FALLS TX 92 66 97 68 / 10 10 10 10 GAGE OK 89 62 93 62 / 10 10 10 10 PONCA CITY OK 83 65 90 68 / 10 10 10 10 DURANT OK 88 65 93 65 / 10 10 0 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 26/30
AREA FORECAST DISCUSSION
NWS NORMAN OK
730 AM CDT TUE MAY 22 2012 .AVIATION... AN ISOLATED SHOWER OR TWO WILL BE POSSIBLE THROUGH MID MORNING...OTHERWISE CLOUDS WILL SLOWLY DISSIPATE DURING THE MORNING. SOUTH TO SOUTHEAST WINDS WILL INCREASE BY MID TO LATE MORNING. && .PREV DISCUSSION... /ISSUED 418 AM CDT TUE MAY 22 2012/ DISCUSSION... MID-LEVEL NORTHWEST TO WEST FLOW WILL GRADUALLY TRANSITION TO A SOUTHWEST FLOW OVER THE NEXT 48 HOURS AS A BROAD TROUGH TAKES SHAPE OVER THE WESTERN HALF OF THE CONUS. MEANWHILE...CONVECTION ACROSS TEXAS PANHANDLE HAS WEAKENED OVERNIGHT WITH MCV-LIKE FEATURE IN WEAK ECHO RETURNS. TO THE EAST...ISOLATED SHOWERS HAVE BEEN FORMING ACROSS THE WESTERN THIRD OF OKLAHOMA FROM HARPER COUNTY TO KIOWA. NAM12 AND RECENT HRRR RUNS ARE MORE BULLISH WITH THE DEVELOPMENT OF MORE SHOWERS/STORMS BETWEEN 10-15Z ACROSS WESTERN HALF OF FA. WITH RECENT DEVELOPMENT WILL ADD 20-30 POPS ACROSS WESTERN 1/3 OF FA. PRECIP THAT DOES DEVELOP SHOULD GRADUALLY WEAKEN DURING THE MID TO LATE MORNING. AFTERNOON CONVECTION MAY DEVELOP WEST OF THE AREA BUT OVERALL COVERAGE MAY LIMIT CHANCES OF IMPACTING WESTERN OKLAHOMA..SO WILL KEEP POPS RATHER LOW. SOUTH WINDS WILL INCREASE SOME TODAY AND WILL BECOME RATHER GUSTY ON WEDNESDAY AS LOW PRESSURE DEEPENS OVER THE HIGHER TERRAIN. A SHORTWAVE WILL MOVE FROM THE CENTRAL ROCKIES INTO THE UPPER MIDWEST LATE WEDNESDAY INTO THURSDAY. THIS FEATURE WILL HELP PUSH A WEAK SURFACE BOUNDARY INTO NORTHWEST AND WEST CENTRAL OKLAHOMA WEDNESDAY NIGHT/EARLY THURSDAY. RATHER WARM 8H TEMPS AND BETTER FORCING NORTH...SHOULD LIMIT STORM CHANCES WITH THIS BOUNDARY. AN UPPER RIDGE WILL BUILD OVER THE SOUTHEAST GOING INTO THE HOLIDAY WEEKEND...WHILE ANOTHER STORM SYSTEM MOVES ACROSS THE WESTERN THIRD OF THE US. EC MODEL STRONGER WITH WESTERN SYSTEM AND MAY BRING A CHANCE OF STORMS TO WESTERN OKLAHOMA BY SUNDAY...AS IT LIFTS NORTH INTO THE NORTHERN ROCKIES AND PLAINS. OVERALL...THE HOLIDAY WEEKEND APPEARS MAINLY DRY AND VERY WARM/HOT WITH BETTER CHANCES FOR STORMS ACROSS WESTERN OK. MODELS SIGNAL A RETURN TO A NORTHWEST FLOW BY THE MIDDLE OF NEXT WEEK WHICH MAY BRING BETTER CHANCES FOR STORMS DURING THE LAST DAYS OF MAY. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 85 65 90 67 / 10 10 10 10 HOBART OK 89 64 95 68 / 10 10 10 10 WICHITA FALLS TX 92 66 97 68 / 10 10 10 10 GAGE OK 89 62 93 62 / 10 10 10 10 PONCA CITY OK 83 65 90 68 / 10 10 10 10 DURANT OK 88 65 93 65 / 10 10 0 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 99/99/01
AREA FORECAST DISCUSSION
NWS NORMAN OK
418 AM CDT TUE MAY 22 2012 .DISCUSSION... MID-LEVEL NORTHWEST TO WEST FLOW WILL GRADUALLY TRANSITION TO A SOUTHWEST FLOW OVER THE NEXT 48 HOURS AS A BROAD TROUGH TAKES SHAPE OVER THE WESTERN HALF OF THE CONUS. MEANWHILE...CONVECTION ACROSS TEXAS PANHANDLE HAS WEAKENED OVERNIGHT WITH MCV-LIKE FEATURE IN WEAK ECHO RETURNS. TO THE EAST...ISOLATED SHOWERS HAVE BEEN FORMING ACROSS THE WESTERN THIRD OF OKLAHOMA FROM HARPER COUNTY TO KIOWA. NAM12 AND RECENT HRRR RUNS ARE MORE BULLISH WITH THE DEVELOPMENT OF MORE SHOWERS/STORMS BETWEEN 10-15Z ACROSS WESTERN HALF OF FA. WITH RECENT DEVELOPMENT WILL ADD 20-30 POPS ACROSS WESTERN 1/3 OF FA. PRECIP THAT DOES DEVELOP SHOULD GRADUALLY WEAKEN DURING THE MID TO LATE MORNING. AFTERNOON CONVECTION MAY DEVELOP WEST OF THE AREA BUT OVERALL COVERAGE MAY LIMIT CHANCES OF IMPACTING WESTERN OKLAHOMA..SO WILL KEEP POPS RATHER LOW. SOUTH WINDS WILL INCREASE SOME TODAY AND WILL BECOME RATHER GUSTY ON WEDNESDAY AS LOW PRESSURE DEEPENS OVER THE HIGHER TERRAIN. A SHORTWAVE WILL MOVE FROM THE CENTRAL ROCKIES INTO THE UPPER MIDWEST LATE WEDNESDAY INTO THURSDAY. THIS FEATURE WILL HELP PUSH A WEAK SURFACE BOUNDARY INTO NORTHWEST AND WEST CENTRAL OKLAHOMA WEDNESDAY NIGHT/EARLY THURSDAY. RATHER WARM 8H TEMPS AND BETTER FORCING NORTH...SHOULD LIMIT STORM CHANCES WITH THIS BOUNDARY. AN UPPER RIDGE WILL BUILD OVER THE SOUTHEAST GOING INTO THE HOLIDAY WEEKEND...WHILE ANOTHER STORM SYSTEM MOVES ACROSS THE WESTERN THIRD OF THE US. EC MODEL STRONGER WITH WESTERN SYSTEM AND MAY BRING A CHANCE OF STORMS TO WESTERN OKLAHOMA BY SUNDAY...AS IT LIFTS NORTH INTO THE NORTHERN ROCKIES AND PLAINS. OVERALL...THE HOLIDAY WEEKEND APPEARS MAINLY DRY AND VERY WARM/HOT WITH BETTER CHANCES FOR STORMS ACROSS WESTERN OK. MODELS SIGNAL A RETURN TO A NORTHWEST FLOW BY THE MIDDLE OF NEXT WEEK WHICH MAY BRING BETTER CHANCES FOR STORMS DURING THE LAST DAYS OF MAY. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 85 65 90 67 / 10 10 10 10 HOBART OK 89 64 95 68 / 30 10 10 10 WICHITA FALLS TX 92 66 97 68 / 30 10 10 10 GAGE OK 89 62 93 62 / 20 10 10 10 PONCA CITY OK 83 65 90 68 / 10 10 10 10 DURANT OK 88 65 93 65 / 10 10 0 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
803 AM EDT TUE MAY 22 2012 .SYNOPSIS... A LARGE SCALE TROUGH OF LOW PRESSURE WILL REMAIN IN PLACE ACROSS THE EASTERN U.S. THROUGH THURSDAY...BRINGING SEVERAL ROUNDS OF SHOWERS AND A FEW THUNDERSTORMS. A SOUTHWEST FLOW OF WARMER AND HUMID AIR WILL FOLLOW FOR FRIDAY...AND THE ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE UPCOMING WEEKEND. A WEAK COLD FRONT WILL ATTEMPT TO PUSH SOUTHEAST THROUGH THE REGION SATURDAY AFTERNOON AND EVENING...BUT COULD STALL OUT ACROSS OR JUST TO THE NORTH OF THE REGION. && .NEAR TERM /THROUGH TONIGHT/... MOST OF THE EARLIER MDT TO HVY SHRA HAVE DISSIPATED ACROSS THE CWA...WITH THE EXCEPTION OF THE NCENT MTNS WHERE A SMALL AREA OF SHOWERS WAS DRIFTING SLOWLY TO THE NORTH. NEARLY NORTH/SOUTH AXIS OF BOUNDARY LAYER THETA-E CONVERGENCE EXTENDED FROM NCENT PENN...TO THE SCENT MTNS AND LAUREL HIGHLANDS EARLY TODAY. 06Z RUC INDICATES THAT THIS AXIS WILL SHIFT A FEW LAYERS OF COUNTIES TO THE WEST BY THIS AFTERNOON...WHILE A NOTABLE AREA OF LLVL MOISTURE DIVERGENCE WILL DRIFT NE AND BECOME LOCATED ACROSS THE SUSQ VALLEY DURING THE MID AFTERNOON HOURS. THE MOST NUMEROUS SHOWERS AND THUNDERSTORMS WILL BE CONFINED TO THE WESTERN HALF OF THE CWA INTO THE LATE AFTERNOON. THE APPROACH OF A AN 850 MB TROUGH AND RIBBON OF SLIGHTLY STEEPER MID LEVEL LAPSE RATES LATE THIS AFTERNOON AND TONIGHT WILL HELP TO SHIFT THE AXIS OF MOST NUMEROUS SHOWERS AND SCTD TSRA TO THE SUSQ VALLEY POINTS EAST FOR VERY LATE TODAY...INTO EARLY WED MORNING. THE SLOW MOVEMENT OF THE SHOWERS AND STORMS TODAY /AND PERSISTENT FOCUS AREA/ COULD LEAD TO SOME MODERATELY HEAVY ADDITIONAL RAINFALL OF 0.5 TO 1.0 OF AN INCH. LESSER AMOUNTS OF RAIN ARE EXPECTED FOR THE FAR NW CORNER OF THE CWA...AND ALSO FROM THE SUSQ VALLEY...EAST. OVERCAST SKIES AND VERY LGT WINDS ALOFT SUGGEST THERE WILL BE VERY LITTLE THREAT OF SVR WX. && .SHORT TERM /WEDNESDAY/... THE MEAN LARGE-SCALE TROUGH AT THE SFC AND ALOFT WILL CONTINUE TO RESIDE RIGHT ALONG THE APPALACHIAN MTN CHAIN THROUGH AT LEAST WEDNESDAY NIGHT...AS THE DEVELOPING UPPER LOW ACROSS THE TENN VALLEY LIFTS SLOWLY NE ACROSS THE VIRGINIAS AND PENN. THE PRIMARY AXIS OF LLVL PWATS AND ASSOCIATED THETA-E CONVERGENCE SHOULD SHIFT SLIGHTLY TO THE EAST ON WEDNESDAY /BECOMING LOCATED FROM THE UPPER SUSQ VALLEY...TO THE SCENT MTNS AND LAURELS/...ALONG AND JUST TO THE EAST OF THE WEAKENING UPPER LOW TRACK. INSTABILITY RAMPS UP A FEW HUNDRED J/KG IN THE CAPE DEPT WEDNESDAY...WITH THE BEST CONVECTIVE POTENTIAL ALONG AND TO THE SE OF A LINE FROM KIPT TO KAOO. VERY WEAK WINDS IN THE LOWEST 15 KFT OF THE ATMOSPHERE WILL KEEP THE EHI/S ON THE VERY LOW SIDE...WITH THE MAIN CHARACTERISTIC OF THE CONVECTION BEING IT/S SLOW MOVEMENT AND LOCALIZED HEAVY RAIN POTENTIAL. PWATS ARE NOT TREMENDOUSLY HIGH - ONLY 1-2 STANDARD DEVIATIONS ABOVE NORMAL...AND WITH THE EXTENSIVE CLOUD COVER...HIGH CAPES OF 2000 J/KG OR MORE WILL BE DIFFICULT TO COME BY. STILL...THE 00Z GEFS AND 03Z SREF TARGET THE SCENT MTNS AND MID SUSQ VALLEY FOR ABOUT A 60 PERCENT CHC FOR SFC BASED CAPES TO EXCEED 1200 J/KG. BASIN AVG RAINFALL AMOUNTS FOR THE NEXT 36 HOURS WILL BE MAINLY IN THE 0.5 TO 1.0 RANGE. AREAS RECEIVING A FEW TSRA COULD SEE NEARLY 1.5 INCHES /AS INDICATED BY SEVERAL SREF AND GEFS PLUME MEMBERS/. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... A SLOWLY FILLING UPPER LOW WILL DRIFT NE FROM THE CENTRAL APPALACHIANS AND CROSS SERN PENN ON THURSDAY. WED EVENING CONVECTION WILL QUICKLY WANE BY 04Z WITH CLOUDY SKIES...LIGHT WIND AND AREAS OF FOG FOLLOWING FOR THE REST OF THE OVERNIGHT HOURS. ISOLATED TO SCATTERED...MAINLY AFTERNOON AND EARLY EVENING SHRA AND TSRA WILL OCCUR THURSDAY AND FRIDAY. GFS AND OTHERS ARE MORE IN LINE WITH KEEPING FRONT NORTH OF OUR AREA THIS COMING HOLIDAY WEEKEND...WHILE THE LATEST EC MAKES AN ATTEMPT TO PUSH THE SHALLOW FRONT TO THE SOUTHERN TIER OF PA SATURDAY NIGHT. A LARGE POOL OF VERY WARM AIR AT THE SFC AND ALOFT FORMS ACROSS THE LOWER-MID MISS VALLEY AND OHIO RIVER VALLEY OVER THE UPCOMING WEEKEND. THE SOUTHERN EDGE OF WNW FLOW ALOFT /FROM THE GREAT LAKES TO THE SOUTHERN NEW ENGLAND COAST/ WILL TRANSPORT SOME RIPPLES OF ENERGY ALOFT ALONG/ABOVE THE LLVL FRONTAL BOUNDARY...POSSIBLY SPARKING SOME SHOWERS AND TSRA. WE COULD EVEN SEE AN MCS OR TWO TRACK SE INTO THE WRN AND CENTRAL CWA FROM THE UPPER LAKES REGION SATURDAY MORNING /AND AGAIN SUNDAY/ WITHIN THE CHANNEL OF PWATS RANGING FROM 32-36MM. GFS BEST ILLUSTRATES THE POTENTIAL /VIA ITS 500 MB VORT PANELS/ FOR A FEW RING OF FIRE MCS/S TO SLIDE SE ACROSS MAINLY NRN AND WESTERN PART OF PENN. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... A LARGE SCALE TROUGH OF LOW PRESSURE WILL REMAIN IN PLACE THROUGH THURSDAY...BRINGING SEVERAL ROUNDS OF SHOWERS AND A FEW THUNDERSTORMS. WIDESPREAD IFR TO MVFR CIGS ACROSS CENTRAL PA THIS MORNING...WILL IMPROVE SLIGHTLY THROUGH LATE MORNING WITH MOST LOCATIONS BECOMING MVFR BY 15Z. SHOWERS AGAIN EXPECTED TO DEVELOP OVER MUCH OF THE REGION BY LATE MORNING...PERSISTING THROUGH THE AFTERNOON - AND EVEN A RUMBLE OF THUNDER POSS THIS AFTERNOON MAINLY SOUTH /BUT CHC TOO LOW TO MENTION IN TAFS ATTM/. CIGS SHOULD CONTINUE TO GRADUALLY IMPROVE THIS AFTERNOON WITH INCREASING AMOUNTS OF VFR CIGS SPREADING IN FROM THE WEST. WEAK FRONT PUSHES ACROSS CWA LATE TODAY AND TONIGHT...WITH VFR CONDITIONS DURING THE EVENING HOURS. BUT PLENTY OF LOW LEVEL MOISTURE WILL ALLOW FOG AND LOW CIGS TO DEVELOP AFTER MIDNIGHT...AGAIN RESTRICTING FLYING. OUTLOOK... WED...WIDESPREAD MVFR/IFR CIGS AND VSBYS LIKELY IN SHRA AND SCT TSRA. THU...PRIMARILY VFR. SCT SHRA/TSRA POSS MAINLY SE. FRI...PRIMARILY VFR. ISOLD SHRA/TSRA POSS MAINLY SE. SAT...VFR. A CHC OF A SHRA OR TSRA ACROSS THE NORTH. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT/MARTIN AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
455 AM EDT TUE MAY 22 2012 .SYNOPSIS... A LARGE SCALE TROUGH OF LOW PRESSURE WILL REMAIN IN PLACE ACROSS THE EASTERN U.S. THROUGH THURSDAY...BRINGING SEVERAL ROUNDS OF SHOWERS AND A FEW THUNDERSTORMS. A SOUTHWEST FLOW OF WARMER AND HUMID AIR WILL FOLLOW FOR FRIDAY...AND THE ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE UPCOMING WEEKEND. A WEAK COLD FRONT WILL ATTEMPT TO PUSH SOUTHEAST THROUGH THE REGION SATURDAY AFTERNOON AND EVENING...BUT COULD STALL OUT ACROSS OR JUST TO THE NORTH OF THE REGION. && .NEAR TERM /THROUGH TONIGHT/... MOST OF THE EARLIER MDT TO HVY SHRA HAVE DISSIPATED ACROSS THE CWA...WITH THE EXCEPTION OF THE NCENT MTNS WHERE A SMALL AREA OF SHOWERS WAS DRIFTING SLOWLY TO THE NORTH. NEARLY NORTH/SOUTH AXIS OF BOUNDARY LAYER THETA-E CONVERGENCE EXTENDED FROM NCENT PENN...TO THE SCENT MTNS AND LAUREL HIGHLANDS EARLY TODAY. 06Z RUC INDICATES THAT THIS AXIS WILL SHIFT A FEW LAYERS OF COUNTIES TO THE WEST BY THIS AFTERNOON...WHILE A NOTABLE AREA OF LLVL MOISTURE DIVERGENCE WILL DRIFT NE AND BECOME LOCATED ACROSS THE SUSQ VALLEY DURING THE MID AFTERNOON HOURS. THE MOST NUMEROUS SHOWERS AND THUNDERSTORMS WILL BE CONFINED TO THE WESTERN HALF OF THE CWA INTO THE LATE AFTERNOON. THE APPROACH OF A AN 850 MB TROUGH AND RIBBON OF SLIGHTLY STEEPER MID LEVEL LAPSE RATES LATE THIS AFTERNOON AND TONIGHT WILL HELP TO SHIFT THE AXIS OF MOST NUMEROUS SHOWERS AND SCTD TSRA TO THE SUSQ VALLEY POINTS EAST FOR VERY LATE TODAY...INTO EARLY WED MORNING. THE SLOW MOVEMENT OF THE SHOWERS AND STORMS TODAY /AND PERSISTENT FOCUS AREA/ COULD LEAD TO SOME MODERATELY HEAVY ADDITIONAL RAINFALL OF 0.5 TO 1.0 OF AN INCH. LESSER AMOUNTS OF RAIN ARE EXPECTED FOR THE FAR NW CORNER OF THE CWA...AND ALSO FROM THE SUSQ VALLEY...EAST. OVERCAST SKIES AND VERY LGT WINDS ALOFT SUGGEST THERE WILL BE VERY LITTLE THREAT OF SVR WX. && .SHORT TERM /WEDNESDAY/... THE MEAN LARGE-SCALE TROUGH AT THE SFC AND ALOFT WILL CONTINUE TO RESIDE RIGHT ALONG THE APPALACHIAN MTN CHAIN THROUGH AT LEAST WEDNESDAY NIGHT...AS THE DEVELOPING UPPER LOW ACROSS THE TENN VALLEY LIFTS SLOWLY NE ACROSS THE VIRGINIAS AND PENN. THE PRIMARY AXIS OF LLVL PWATS AND ASSOCIATED THETA-E CONVERGENCE SHOULD SHIFT SLIGHTLY TO THE EAST ON WEDNESDAY /BECOMING LOCATED FROM THE UPPER SUSQ VALLEY...TO THE SCENT MTNS AND LAURELS/...ALONG AND JUST TO THE EAST OF THE WEAKENING UPPER LOW TRACK. INSTABILITY RAMPS UP A FEW HUNDRED J/KG IN THE CAPE DEPT WEDNESDAY...WITH THE BEST CONVECTIVE POTENTIAL ALONG AND TO THE SE OF A LINE FROM KIPT TO KAOO. VERY WEAK WINDS IN THE LOWEST 15 KFT OF THE ATMOSPHERE WILL KEEP THE EHI/S ON THE VERY LOW SIDE...WITH THE MAIN CHARACTERISTIC OF THE CONVECTION BEING IT/S SLOW MOVEMENT AND LOCALIZED HEAVY RAIN POTENTIAL. PWATS ARE NOT TREMENDOUSLY HIGH - ONLY 1-2 STANDARD DEVIATIONS ABOVE NORMAL...AND WITH THE EXTENSIVE CLOUD COVER...HIGH CAPES OF 2000 J/KG OR MORE WILL BE DIFFICULT TO COME BY. STILL...THE 00Z GEFS AND 03Z SREF TARGET THE SCENT MTNS AND MID SUSQ VALLEY FOR ABOUT A 60 PERCENT CHC FOR SFC BASED CAPES TO EXCEED 1200 J/KG. BASIN AVG RAINFALL AMOUNTS FOR THE NEXT 36 HOURS WILL BE MAINLY IN THE 0.5 TO 1.0 RANGE. AREAS RECEIVING A FEW TSRA COULD SEE NEARLY 1.5 INCHES /AS INDICATED BY SEVERAL SREF AND GEFS PLUME MEMBERS/. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... A SLOWLY FILLING UPPER LOW WILL DRIFT NE FROM THE CENTRAL APPALACHIANS AND CROSS SERN PENN ON THURSDAY. WED EVENING CONVECTION WILL QUICKLY WANE BY 04Z WITH CLOUDY SKIES...LIGHT WIND AND AREAS OF FOG FOLLOWING FOR THE REST OF THE OVERNIGHT HOURS. ISOLATED TO SCATTERED...MAINLY AFTERNOON AND EARLY EVENING SHRA AND TSRA WILL OCCUR THURSDAY AND FRIDAY. GFS AND OTHERS ARE MORE IN LINE WITH KEEPING FRONT NORTH OF OUR AREA THIS COMING HOLIDAY WEEKEND...WHILE THE LATEST EC MAKES AN ATTEMPT TO PUSH THE SHALLOW FRONT TO THE SOUTHERN TIER OF PA SATURDAY NIGHT. A LARGE POOL OF VERY WARM AIR AT THE SFC AND ALOFT FORMS ACROSS THE LOWER-MID MISS VALLEY AND OHIO RIVER VALLEY OVER THE UPCOMING WEEKEND. THE SOUTHERN EDGE OF WNW FLOW ALOFT /FROM THE GREAT LAKES TO THE SOUTHERN NEW ENGLAND COAST/ WILL TRANSPORT SOME RIPPLES OF ENERGY ALOFT ALONG/ABOVE THE LLVL FRONTAL BOUNDARY...POSSIBLY SPARKING SOME SHOWERS AND TSRA. WE COULD EVEN SEE AN MCS OR TWO TRACK SE INTO THE WRN AND CENTRAL CWA FROM THE UPPER LAKES REGION SATURDAY MORNING /AND AGAIN SUNDAY/ WITHIN THE CHANNEL OF PWATS RANGING FROM 32-36MM. GFS BEST ILLUSTRATES THE POTENTIAL /VIA ITS 500 MB VORT PANELS/ FOR A FEW RING OF FIRE MCS/S TO SLIDE SE ACROSS MAINLY NRN AND WESTERN PART OF PENN. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... SEMI-PERSISTENT N-S AXIS OF RAIN SPLITTING CWA THIS MORNING...CONTINUES TO GRADUALLY WEAKEN. OUTSIDE OF THAT...ANY PRECIP WILL BE ISOLATED AND LIGHT THROUGH THE OVERNIGHT HOURS. MVFR TO IFR CONDITIONS HAVE SETTLED IN WITH LOWERING CIGS IN VERY MOIST AIRMASS. EXPECT THESE TO DROP EVEN FURTHER OVERNIGHT...WITH WIDESPREAD IFR-LIFR LINGERING INTO THE MID MORNING. SOME DIURNAL IMPROVEMENT IN CONDITIONS ON TUESDAY AS CIGS LIFT TO MVFR DURING THE MID/LATE MORNING...EVENTUALLY BECOMING VFR IN MANY PLACES DURING THE AFTERNOON AS UPPER FLOW BECOMES A BIT MORE SOUTHERLY IN ADVANCE OF NEWLY DEVELOPING TN VALLEY UPPER LEVEL LOW. WITH THE POTENTIAL INCREASE IN CIGS AND VSBYS WILL BE INCREASING CHANCES OF SHOWERS AND POSSIBLE TSRA...BRINGING LOCAL RESTRICTIONS. OUTLOOK... WED...WIDESPREAD MVFR/IFR CIGS AND VSBYS LIKELY IN SHRA AND SCT TSRA. THU...PRIMARILY VFR. SCT SHRA/TSRA POSS MAINLY SE. FRI...PRIMARILY VFR. ISOLD SHRA/TSRA POSS MAINLY SE. SAT...VFR. A CHC OF A SHRA OR TSRA ACROSS THE NORTH. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT/MARTIN AVIATION...JUNG/RXR
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
550 PM CDT TUE MAY 22 2012 .AVIATION... ISOLATED CHANCE FOR A THUNDERSTORM THROUGH 03Z. OTHERWISE...VFR EXPECTED. THERE IS AN OUTSIDE CHANCE THAT THE SEA BREEZE MAY BECOME ACTIVE WEDNESDAY AFTERNOON AFTER 21Z. FOR NOW THE CHANCES ARE 10 PERCENT AND WILL NOT MENTION IN THE FORECAST. 40 && .PREV DISCUSSION... /ISSUED 336 PM CDT TUE MAY 22 2012/ DISCUSSION... SHRA AND A FEW TSRA HAVE FORMED EARLIER TODAY THAN YESTERDAY IN MADISON...WALKER...SAN JACINTO AND LIBERTY COUNTIES AND SLIGHTLY MORE COVERAGE AS WELL. HAVE NUDGED POPS UP AROUND THOSE AREAS FOR THE REST OF THIS AFTERNOON AND INTO THE MID EVENING HOURS. CONVECTIVE TEMPERATURES WERE MET AND UPSTREAM DISTURBANCE HELPED THIS ALONG TODAY. STILL EXPECT TSRA TO BE MOSTLY DIURNAL AND SHOULD DIMINISH AFTER SUNSET. HRRR REFLECTIVITY FIELD FORECASTS AGREE WITH THIS ASSESSMENT AS WELL. GALVESTON HIT 90F AT 1252PM WHICH TIED THE RECORD HIGH FOR TODAY. COULD HAVE GONE A LITTLE HIGHER BUT WINDS SHIFTED ONSHORE WITH A SEA BREEZE JUST A FEW HOURS EARLIER THAN EXPECTED TODAY. AS SURFACE HIGH OVER NW GULF MOVES SLOWLY AWAY AND LEE TROUGH DEVELOPS TOMORROW ONSHORE WINDS WILL INCREASE. PWATS REMAIN AROUND NORMAL FOR MARCH-MAY VALUES. MEAN 1000-700MB SOUTHWESTERLY TO SOUTHWESTERLY WINDS SHOULD INCREASE THE CAPPING INVERSION LEADING TO A DRY SPELL FOR THE NEXT SEVERAL DAYS. GULF MOISTURE DOES NOT LOOK TO BE FULLY TAPPED UNTIL SATURDAY MORNING BUT REMAINS TRAPPED UNDERNEATH GIANT SUBSIDENCE INVERSION AS UPPER RIDGING TAKES HOLD OVER THE EAST HALF OF THE COUNTRY. COULD SEE A FEW VERY LOW TOPPED -SHRA AT TIMES IN THE EXTENDED PERIOD UNDER THE CAP BUT NOT COVERAGE WOULD BE ISOLATED AT BEST AND AMOUNTS VERY VERY LOW SO WILL LEAVE OUT MENTION OF PCPN IN THE EXTENDED. VERY LITTLE CHANGE IN MAX TEMPS THE NEXT FEW DAYS WITH ONLY SOME VERY TINY MODERATION AS LOW LEVEL HUMIDITY AND ONSHORE FLOW COMMENCES. MORNING LOWS TO CLIMB A TAD AS RH INCREASES. NOT BUYING GFS SOLUTION IN LONG RANGE OF LOOP-D-LOOPING SFC LOW RETURNING FROM THE ATLANTIC...PREFER ECMWF LIKE SOLUTION OF CONTINUING TROUGHING OUT THAT WAY. AS A WISE FCSTR ONCE SAID ABOUT THE LONG RANGE TROPICS...IF IT AINT IN THE ECMWF YET I AINT BELIEVING IT. GOOD WORDS GENERALLY. 04 AVIATION... TOOK OUT THE MENTION OF CB/PCPN FOR THIS AFTN WITH THE 18Z TAFS AS THERE WAS SOME UNCERTAINTY CONCERNING THE START TIME TO THE DEVEL- OPMENT. BUT IT LOOKS LIKE THINGS ARE GOING SOONER THAN EXPECTED SO WILL LIKELY BE ADDING VCTS/CB IN THE TAFS VIA AMENDMENTS AS STORMS APPROACH THE VARIOUS SITES. OTHERWISE STILL EXPECTING PCPN TO WANE WITH THE LOSS OF DAYTIME HEATING. MOSTLY VFR OVERNIGHT WITH PATCHY BR IN THE USUAL SPOTS (CXO/LBX). ONSHORE FLOW PATTERN EVOLVING THE NEXT FEW DAYS COULD MAKE FOR A SLIGHTLY MORE ACTIVE SEABREEZE. 41 MARINE... NOT A LOT OF CHANGES TO THE GOING FCST OF DEVELOPING ONSHORE WINDS THE NEXT FEW DAYS. WIND SPEEDS/WAVE HEIGHTS NOT EXPECTED TO BE AT/ NEAR CAUTION/ADVISORY LEVELS UNTIL LATE WEDS AS THE PRESSURE GRAD- IENT TIGHTENS IN RESPONSE TO THE NEXT SYSTEM DEEPENING ACROSS/OVER THE CENTRAL PLAINS. AS THIS PATTERN IS PROGGED TO PERSIST THE REST OF THE WEEK...WE COULD ALSO SEE WAVE HEIGHTS INCREASE STEADILY FOR THIS SAME TIME FRAME. 41 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 67 92 68 91 71 / 30 10 10 10 10 HOUSTON (IAH) 70 90 70 90 73 / 20 10 10 10 10 GALVESTON (GLS) 76 86 76 86 78 / 10 10 10 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...43 AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
336 PM CDT TUE MAY 22 2012 .DISCUSSION... SHRA AND A FEW TSRA HAVE FORMED EARLIER TODAY THAN YESTERDAY IN MADISON...WALKER...SAN JACINTO AND LIBERTY COUNTIES AND SLIGHTLY MORE COVERAGE AS WELL. HAVE NUDGED POPS UP AROUND THOSE AREAS FOR THE REST OF THIS AFTERNOON AND INTO THE MID EVENING HOURS. CONVECTIVE TEMPERATURES WERE MET AND UPSTREAM DISTURBANCE HELPED THIS ALONG TODAY. STILL EXPECT TSRA TO BE MOSTLY DIURNAL AND SHOULD DIMINISH AFTER SUNSET. HRRR REFLECTIVITY FIELD FORECASTS AGREE WITH THIS ASSESSMENT AS WELL. GALVESTON HIT 90F AT 1252PM WHICH TIED THE RECORD HIGH FOR TODAY. COULD HAVE GONE A LITTLE HIGHER BUT WINDS SHIFTED ONSHORE WITH A SEA BREEZE JUST A FEW HOURS EARLIER THAN EXPECTED TODAY. AS SURFACE HIGH OVER NW GULF MOVES SLOWLY AWAY AND LEE TROUGH DEVELOPS TOMORROW ONSHORE WINDS WILL INCREASE. PWATS REMAIN AROUND NORMAL FOR MARCH-MAY VALUES. MEAN 1000-700MB SOUTHWESTERLY TO SOUTHWESTERLY WINDS SHOULD INCREASE THE CAPPING INVERSION LEADING TO A DRY SPELL FOR THE NEXT SEVERAL DAYS. GULF MOISTURE DOES NOT LOOK TO BE FULLY TAPPED UNTIL SATURDAY MORNING BUT REMAINS TRAPPED UNDERNEATH GIANT SUBSIDENCE INVERSION AS UPPER RIDGING TAKES HOLD OVER THE EAST HALF OF THE COUNTRY. COULD SEE A FEW VERY LOW TOPPED -SHRA AT TIMES IN THE EXTENDED PERIOD UNDER THE CAP BUT NOT COVERAGE WOULD BE ISOLATED AT BEST AND AMOUNTS VERY VERY LOW SO WILL LEAVE OUT MENTION OF PCPN IN THE EXTENDED. VERY LITTLE CHANGE IN MAX TEMPS THE NEXT FEW DAYS WITH ONLY SOME VERY TINY MODERATION AS LOW LEVEL HUMIDITY AND ONSHORE FLOW COMMENCES. MORNING LOWS TO CLIMB A TAD AS RH INCREASES. NOT BUYING GFS SOLUTION IN LONG RANGE OF LOOP-D-LOOPING SFC LOW RETURNING FROM THE ATLANTIC...PREFER ECMWF LIKE SOLUTION OF CONTINUING TROUGHING OUT THAT WAY. AS A WISE FCSTR ONCE SAID ABOUT THE LONG RANGE TROPICS...IF IT AINT IN THE ECMWF YET I AINT BELIEVING IT. GOOD WORDS GENERALLY. 04 .AVIATION... TOOK OUT THE MENTION OF CB/PCPN FOR THIS AFTN WITH THE 18Z TAFS AS THERE WAS SOME UNCERTAINTY CONCERNING THE START TIME TO THE DEVEL- OPMENT. BUT IT LOOKS LIKE THINGS ARE GOING SOONER THAN EXPECTED SO WILL LIKELY BE ADDING VCTS/CB IN THE TAFS VIA AMENDMENTS AS STORMS APPROACH THE VARIOUS SITES. OTHERWISE STILL EXPECTING PCPN TO WANE WITH THE LOSS OF DAYTIME HEATING. MOSTLY VFR OVERNIGHT WITH PATCHY BR IN THE USUAL SPOTS (CXO/LBX). ONSHORE FLOW PATTERN EVOLVING THE NEXT FEW DAYS COULD MAKE FOR A SLIGHTLY MORE ACTIVE SEABREEZE. 41 && .MARINE... NOT A LOT OF CHANGES TO THE GOING FCST OF DEVELOPING ONSHORE WINDS THE NEXT FEW DAYS. WIND SPEEDS/WAVE HEIGHTS NOT EXPECTED TO BE AT/ NEAR CAUTION/ADVISORY LEVELS UNTIL LATE WEDS AS THE PRESSURE GRAD- IENT TIGHTENS IN RESPONSE TO THE NEXT SYSTEM DEEPENING ACROSS/OVER THE CENTRAL PLAINS. AS THIS PATTERN IS PROGGED TO PERSIST THE REST OF THE WEEK...WE COULD ALSO SEE WAVE HEIGHTS INCREASE STEADILY FOR THIS SAME TIME FRAME. 41 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 92 67 92 68 91 / 20 30 10 10 10 HOUSTON (IAH) 94 70 90 70 90 / 20 20 10 10 10 GALVESTON (GLS) 90 76 86 76 86 / 10 10 10 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...04
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
100 PM CDT TUE MAY 22 2012 .AVIATION... THE ONLY AVIATION WEATHER CONCERNS TODAY WILL ISOLATED SHOWERS THIS AFTERNOON ASSOCIATED WITH A WEAK MCV...CURRENTLY WEST OF THE TAF SITES. THE MCV WILL CONTINUE ON A SOUTHEAST TRACK AND A FEW SHOWERS ON THE PERIPHERY OF THE CIRCULATION MAY GRAZE THE METROPLEX TAF SITES WITH A SLIGHTLY BETTER CHANCE OF A BRIEF SHOWER AT WACO. SINCE IMPACTS WITH ANY OF THESE ELEVATED SHOWERS SHOULD BE MINIMAL...WILL NOT MENTION IN THIS TAF PACKAGE. ANY SHOWERS THAT DO MANAGE TO FORM SHOULD DISSIPATE WITH THE LOSS OF SURFACE HEATING. EXPECT VFR CONDITIONS TONIGHT AND WEDNESDAY. A SOUTH WIND WILL PREVAIL BETWEEN 5 AND 11 KNOTS THIS AFTERNOON AND TONIGHT. SOUTHERLY WINDS WILL INCREASE SIGNIFICANTLY WEDNESDAY AS SURFACE LOW PRESSURE DEEPENS ACROSS THE HIGH PLAINS. SUSTAINED WIND SPEEDS WILL RANGE FROM 15 TO 20 MPH WITH SOME HIGHER GUSTS. 79 && .UPDATE... THE WEAK SURFACE FRONT SITS NEAR A LINE FROM LEON TO STEPHENVILLE TO BRYSON. 925 MB FLOW SHOWS WEAK CONVERGENCE NEAR THE FRONT...WHICH BY THIS AFTERNOON SHOULD BE LOCATED NEAR A BOWIE TO FORT WORTH TO PALESTINE LINE. MORNING MODELS SUCH AS HRRR AND NAM AND GFS ARE A BIT MORE AGGRESSIVE DEVELOPING SOME CONVECTION ALONG THIS LINE SO HAVE ADDED ISOLD POPS FARTHER EAST THAN PREVIOUS. OTHERWISE...FEW CHANGES TO THE PACKAGE. 84 && .PREV DISCUSSION... /ISSUED 340 AM CDT TUE MAY 22 2012/ CIRRUS BLOWOFF FROM THE THUNDERSTORMS IN THE PANHANDLE AND SOUTH PLAINS OF WEST TEXAS CONTINUE TO SPREAD SOUTHEAST ACROSS NORTH TEXAS THIS MORNING. EXPECT THESE CLOUDS TO THIN LATER THIS MORNING...AND WE SHOULD SEE TEMPERATURES CLIMB INTO THE MID 80S NORTHEAST TO MID 90S SOUTH THIS AFTERNOON. AS A SHORTWAVE MOVES SOUTHEAST OUT OF THE PANHANDLE...A FEW THUNDERSTORMS MAY AFFECT THE WESTERN COUNTIES. THUS HAVE LEFT LOW POPS THERE. OTHERWISE... IT LOOKS LIKE A WARM AND DRY PERIOD WILL OCCUR THROUGH THE WEEKEND. AS A SURFACE TROUGH DEVELOPS ACROSS THE NORTHERN AND CENTRAL PLAINS...WE WILL SEE SOUTHERLY WINDS INCREASE WEDNESDAY AND THURSDAY. AN UPPER LEVEL RIDGE WILL DEVELOP ACROSS THE SOUTHEASTERN UNITED STATES FRIDAY INTO THE WEEKEND. AS LOW LEVEL MOISTURE INCREASES...CAN NOT RULE OUT SOME ISOLATED AFTERNOON/EARLY EVENING THUNDERSTORMS SUNDAY AND MONDAY...BUT RAIN CHANCES ARE NOT HIGH ENOUGH TO MENTION YET. 58 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 91 69 93 71 95 / 10 10 5 10 10 WACO, TX 93 67 95 71 95 / 20 10 5 10 10 PARIS, TX 85 62 89 67 88 / 5 5 5 10 10 DENTON, TX 91 68 93 71 95 / 10 10 5 10 10 MCKINNEY, TX 90 66 92 70 92 / 10 10 5 10 10 DALLAS, TX 92 70 93 71 94 / 10 10 5 10 10 TERRELL, TX 88 66 92 69 93 / 10 10 5 10 10 CORSICANA, TX 91 67 92 70 93 / 10 10 5 10 10 TEMPLE, TX 92 66 93 70 94 / 20 5 5 10 5 MINERAL WELLS, TX 91 65 94 68 97 / 20 10 5 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 79/84
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1042 AM CDT TUE MAY 22 2012 .UPDATE... THE WEAK SURFACE FRONT SITS NEAR A LINE FROM LEON TO STEPHENVILLE TO BRYSON. 925 MB FLOW SHOWS WEAK CONVERGENCE NEAR THE FRONT...WHICH BY THIS AFTERNOON SHOULD BE LOCATED NEAR A BOWIE TO FORT WORTH TO PALESTINE LINE. MORNING MODELS SUCH AS HRRR AND NAM AND GFS ARE A BIT MORE AGGRESSIVE DEVELOPING SOME CONVECTION ALONG THIS LINE SO HAVE ADDED ISOLD POPS FARTHER EAST THAN PREVIOUS. OTHERWISE...FEW CHANGES TO THE PACKAGE. 84 && .AVIATION... CONCERNS...NONE. VFR CONDITIONS ARE EXPECTED TO PREVAIL. LIGHT AND VARIABLE WINDS AT THE BEGINNING OF THE TAF PERIOD WILL BECOME SOUTH-SOUTHEASTERLY DURING THE MORNING HOURS. WIND SPEEDS TODAY WILL REMAIN AT OR BELOW 10 KTS. HOWEVER...WIND SPEEDS WILL INCREASE WEDNESDAY MORNING WITH SUSTAINED SPEEDS OF 15-20 KTS...GUSTING UP TO 30 KTS...FOR MUCH OF THE DAY TOMORROW. THERE IS ANOTHER SMALL CHANCE FOR SHOWERS AND THUNDERSTORMS TODAY BUT IF ANY STORMS DO DEVELOP THEY WOULD LIKELY REMAIN WEST OF THE TAF TERMINALS. 82/JLD && .PREV UPDATE... .UPDATE... A QUICK UPDATE WAS DONE TO ADJUST THE POPS IN THE WEST THIS MORNING A LITTLE TO ACCOUNT FOR THE SHOWERS ASSOCIATED WITH THE VORTEX NORTHWEST OF ABILENE. 58 && .PREV DISCUSSION... /ISSUED 340 AM CDT TUE MAY 22 2012/ CIRRUS BLOWOFF FROM THE THUNDERSTORMS IN THE PANHANDLE AND SOUTH PLAINS OF WEST TEXAS CONTINUE TO SPREAD SOUTHEAST ACROSS NORTH TEXAS THIS MORNING. EXPECT THESE CLOUDS TO THIN LATER THIS MORNING...AND WE SHOULD SEE TEMPERATURES CLIMB INTO THE MID 80S NORTHEAST TO MID 90S SOUTH THIS AFTERNOON. AS A SHORTWAVE MOVES SOUTHEAST OUT OF THE PANHANDLE...A FEW THUNDERSTORMS MAY AFFECT THE WESTERN COUNTIES. THUS HAVE LEFT LOW POPS THERE. OTHERWISE... IT LOOKS LIKE A WARM AND DRY PERIOD WILL OCCUR THROUGH THE WEEKEND. AS A SURFACE TROUGH DEVELOPS ACROSS THE NORTHERN AND CENTRAL PLAINS...WE WILL SEE SOUTHERLY WINDS INCREASE WEDNESDAY AND THURSDAY. AN UPPER LEVEL RIDGE WILL DEVELOP ACROSS THE SOUTHEASTERN UNITED STATES FRIDAY INTO THE WEEKEND. AS LOW LEVEL MOISTURE INCREASES...CAN NOT RULE OUT SOME ISOLATED AFTERNOON/EARLY EVENING THUNDERSTORMS SUNDAY AND MONDAY...BUT RAIN CHANCES ARE NOT HIGH ENOUGH TO MENTION YET. 58 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 91 69 93 71 95 / 10 10 5 10 10 WACO, TX 93 67 95 71 95 / 20 10 5 10 10 PARIS, TX 85 62 89 67 88 / 5 5 5 10 10 DENTON, TX 91 68 93 71 95 / 10 10 5 10 10 MCKINNEY, TX 90 66 92 70 92 / 10 10 5 10 10 DALLAS, TX 92 70 93 71 94 / 10 10 5 10 10 TERRELL, TX 88 66 92 69 93 / 10 10 5 10 10 CORSICANA, TX 91 67 92 70 93 / 10 10 5 10 10 TEMPLE, TX 92 66 93 70 94 / 20 5 5 10 5 MINERAL WELLS, TX 91 65 94 68 97 / 20 10 5 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ /
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1149 PM CDT MON MAY 21 2012 .DISCUSSION... /SEE BELOW FOR AVIATION DISCUSSION/ && .AVIATION... LARGE COMPLEX OF THUNDERSTORMS MOVING SOUTHEAST AT 20 KTS OUT OF THE PANHANDLE WILL LIKELY WEAKEN AND DISSIPATE AS IT APPROACHES WEST CENTRAL TEXAS LATE TONIGHT...ACCORDING TO THE RUC NAM AND GFS MODELS. HOWEVER IF THE COMPLEX DOES SURVIVE MOVING OFF THE CAPROCK ...IT WOULD STILL TAKE UNTIL AFTER 12Z TO AFFECT KSJT AND KABI. WILL CONTINUE VFR CONDITIONS IN THE TAFS. 04 && .PREV DISCUSSION... /ISSUED 948 PM CDT MON MAY 21 2012/ DISCUSSION... HAVE UPDATED THE FORECAST TO TAKE OUT THE EARLY MENTION OF THUNDERSTORMS...AND MAKE SLIGHT ADJUSTMENTS TO THE POPS/WX AFTER MIDNIGHT TONIGHT. LATEST MODEL GUIDANCE SUGGESTS THE MCS THAT HAS FORMED NORTHWEST OF LUBBOCK THIS EVENING COULD SURVIVE LONG ENOUGH TO MAKE IT INTO OUR NORTHWEST COUNTIES AFTER MIDNIGHT TONIGHT... AND POSSIBLY EVEN RESULT IN ISOLATED SHOWERS/THUNDERSTORMS MAKING IT TO NEAR THE ABILENE AREA TOWARDS SUNRISE. NO OTHER CHANGES WERE MADE TO THE FORECAST. UPDATED PRODUCTS WILL BE OUT SOON...GRIDS HAVE BEEN SENT AND PUBLISHED. 20 PREV DISCUSSION... /ISSUED 611 PM CDT MON MAY 21 2012/ DISCUSSION... /SEE BELOW FOR AVIATION DISCUSSION/ AVIATION... ISOLATED SHOWERS POSSIBLE NEAR BRADY AS AN OUTFLOW BOUNDARY MOVES THROUGH AROUND 1Z...BUT TOO REMOTE TO INCLUDE IN THE KBBD TAF. POTENTIAL EXISTS FOR A FEW PATCHES OF STRATUS POSSIBLE TOWARD DAYBREAK...MAINLY ALONG THE I-10 CORRIDOR. HOWEVER MOST AREAS WILL REMAIN VFR AND WILL KEEP TAFS VFR. 04 PREV DISCUSSION... /ISSUED 311 PM CDT MON MAY 21 2012/ SHORT TERM... STALLED COLD FRONT IS LOCATED ALONG A LINE FROM NEAR SWEETWATER...TO JUST NORTH OF ABILENE. TOWERING CUMULUS IS EVIDENT ON VISIBLE SATELLITE ALONG AND AHEAD OF THE BOUNDARY...OVER THE SOUTHERN BIG COUNTRY AND NORTHERN CONCHO VALLEY. SHOWERS ARE STRUGGLING TO DEVELOP THIS AFTERNOON...BUT AS CONTINUED HEATING HELPS TO DECREASE THE CAP LATER THIS AFTERNOON...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS MAY DEVELOP ACROSS PARTS OF THE BIG COUNTRY AND CONCHO VALLEY. EXPECT MOST OF THE ACTIVITY TO QUICKLY DISSIPATE SHORTLY AFTER SUNSET. THE NEXT MAIN ISSUE IS WHETHER AN MCS WILL DEVELOP OVER THE SOUTH PLAINS REGION...AND TRY TO MOVE INTO AT LEAST THE NORTHWEST PORTIONS OF WEST CENTRAL TEXAS EARLY TUESDAY MORNING. FOR NOW...HAVE SLIGHT CHANCE POPS ACROSS BIG COUNTRY AFTER 06Z...WITH MOST CONVECTION ENDING BY 12Z. ON TUESDAY...A SURFACE TROUGH WILL DEVELOP ALONG THE LEE SIDE OF THE ROCKIES...INCREASING THE SURFACE PRESSURE GRADIENT OVER WEST CENTRAL TEXAS SLIGHTLY. SOUTH WINDS WILL INCREASE TO 10 TO 15 MPH. 850MB TEMPERATURES LOOK SLIGHTLY WARMER THAN WHAT IS BEING EXPERIENCED THIS AFTERNOON...SO FORECAST REFLECTS SLIGHTLY WARMER TEMPERATURES. HIGHS AROUND THE AREA WILL GENERALLY BE IN THE LOWER 90S. LONG TERM... LONGER TERM PORTION OF THE FORECAST APPEARS FAIRLY QUIET OVERALL. AS A DEEP LONGWAVE TROUGH DEVELOPS OVER THE ROCKIES...THE NORTHWEST FLOW ALOFT WILL TRANSITION TO SOUTHWEST FLOW BY LATE WEDNESDAY. DRYLINE WILL DEVELOP AND SLOSH BACK AND FORTH ACROSS THE PERMIAN BASIN AND INTO THE WESTERN CONCHO VALLEY AND BIG COUNTRY...BUT CAP STRENGTH LOOKS AWFULLY STRONG THROUGH THE REST OF THE WEEK. WILL KEEP THE FORECAST DRY FOR NOW. TEMPERATURES AHEAD OF THE DRYLINE WILL BE AT OR A LITTLE ABOVE NORMAL...BUT STRONGER SOUTHWEST DOWNSLOPE FLOW BEHIND THE DRYLINE WILL DRIVE TEMPERATURES TO NEAR THE 100 DEGREE MARK ACROSS THE WESTERN CONCHO VALLEY AND BIG COUNTRY. BOTH THE GFS AND THE ECMWF INDICATE A STRONGER SHORTWAVE ROTATING INTO THE SOUTHERN PLAINS FOR SATURDAY AFTERNOON AND EVENING. GIVEN THIS ADDED BOOST...A FEW STORMS MAY BE POSSIBLE. STILL...HAVE SOME QUESTIONS ABOUT THE TIMING AND STRENGTH OF THE WAVE...SO WILL HOLD OFF FOR NOW AND CONTINUE TO MONITOR. && .PRELIMINARY POINT TEMPS/POPS... ABILENE 64 91 67 95 71 / 20 10 10 0 10 SAN ANGELO 63 92 65 96 70 / 10 10 0 0 10 JUNCTION 61 91 65 92 67 / 10 0 0 0 0 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 99/99/04
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
100 PM EDT TUE MAY 22 2012 .SYNOPSIS... A COLD FRONT SLOWLY PUSHES EAST ACROSS THE AREA THROUGH TONIGHT...AND THEN TO THE COAST BY LATE WEDNESDAY. SHOWERS AND THUNDERSTORMS...WITH SOME POTENTIALLY BRINGING HEAVY RAIN...WILL BE POSSIBLE THROUGH THURSDAY. HIGH PRESSURE AND DRIER WEATHER WILL ARRIVE LATE IN THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 945 AM EDT TUESDAY... WEAK FRONT EDGING INTO THE FAR WESTERN SECTIONS THIS MORNING LOOKS TO BE THE MAIN FOCUS FOR DEEPER AFTERNOON CONVECTION ESPCLY ACROSS THE MOUNTAINS NEAR THE EDGE OF THE CLOUD CANOPY TO THE WEST ATTM. LATEST MODIFIED MORNING RAOBS SHOW 1500-2K J/KG CAPES PROVIDED ENOUGH HEATING THIS AFTERNOON UNDER LIGHT STEERING PER A MEAN FLOW OF 6-10 KTS. THIS SHOULD AGAIN SPELL SLOW MOVING CLUSTERS OF STORMS ESPCLY MOUNTAINS WITH A FEW OF THESE PERHAPS GOING SEVERE WITH DOWNBURST POTENTIAL PER DECENT WINDEX VALUES...AND SOME HAIL GIVEN LOW WET BULB VALUES OFF MORNING SOUNDINGS. HOWEVER WITH SUCH A MID LEVEL CAP SEEN THIS MORNING MAY TAKE THINGS A LITTLE LONGER TO DEVELOP WITH BETTER FOCUS LATER ON WEST AS THE UPPER LOW STARTS TO LIFT NE ALONG THE SRN APPALACHIANS. THUS MAIN CHANGES WERE TO SLOW DOWN ONSET OF CONVECTION THIS MORNING AND THEN INCREASE POPS SOME WEST WHERE KEEPING HEAVY RAIN MENTION/WATCH IN PLACE. THIS SUPPORTED BY EXPANSIVE COVERAGE OFF BOTH THE LATEST HRRR AND LOCAL WRF MODELS AFTER MIDDAY INTO EARLY THIS EVENING. EXTENT OF TSRA COVERAGE A BIT MORE IFFY E/SE GIVEN LESS SUPPORT AND MORE OUTFLOW DRIVEN...BUT EXPECT HIGH CAPES AND EVENTUAL SPILLING OF WESTERN CONVECTION TO SUPPORT LIKELY POPS THERE. RAISED HIGH TEMPS SLIGHTLY ALONG THE BLUE RIDGE WHERE SHOULD SEE MORE SUN EARLY OTRW 70S WEST TO LOW 80S EAST APPEAR ON TRACK. AS OF 615 AM EDT TUESDAY... UPDATE TO DROP POPS SOME THIS MORNING GIVEN RADAR TRENDS. WILL SEE INCREASE IN COVERAGE AGAIN OVER THE MTNS BY LATE MORNING. DECREASED CLOUD COVERAGE EARLY AS WELL ESPECIALLY THE SRN CWA. PREVIOUS DISCUSSION AT 355 AM... ECHOES ON RADAR WEAKENING AS EXPECTED BUT NOT SURPRISED THAT SHOWERS HAVE LINGERED ALL NIGHT...PER HIGHER THETA-E AIR AND LINGERING BOUNDARIES AND UPPER SUPPORT. TODAY WILL BE ANOTHER STORMY ONE FOR THE AREA AND EXPECT MORE COVERAGE OF SHOWERS AND STORMS. GIVEN THE RAINFALL OVER THE MOUNTAINS THAT LAST FEW DAYS AND LOWER FFG VALUES COMBINED WITH A PATTERN CONDUCIVE TO SLOW MOVING STORMS AND HIGH PWATS...HAVE WENT AHEAD AN ISSUED A FLASH FLOOD WATCH FOR AREAS ALONG AND WEST OF THE BLUE RIDGE. THE FOCUS TODAY WILL BE ACROSS THE MOUNTAINS WHERE BEST UPPER DIFFLUENCE IS EXPECTED WITH UPPER TROUGH. AT THE SFC...COLD FRONT WILL BE EDGING EWD TO THE BLUE RIDGE BY EVENING WITH SEVERAL WEAK LOWS MOVING ALONG IT. WITH EXTENSIVE CLOUD COVER...NOT EXPECT A WIDESPREAD THREAT FOR SVR BUT WITH MOIST AIRMASS...AND COLDER AIR ALOFT WITH THE UPPER TROUGH...WOULD NOT BE SURPRISED THAT SOME STORMS BECOME STRONG TO SEVERE WITH ISOLATED LARGE HAIL/MICROBURST THREAT. WINDS ALOFT ARE WEAK...SO WOULD HAVE TO BE ENOUGH RAIN LOADING IN THE STORM TO BRING DAMAGING WINDS. WILL HAVE HIGHER POPS THIS AFTERNOON WITH CATEGORICAL ACROSS THE BLUE RIDGE AND WEST. WITH MOIST AIRMASS AND LESS SUN WILL SEE HIGHS IN BETWEEN THE COOLER MET/WARMER MAV...ALTHOUGH COOLER MET MAY HAVE A BETTER IDEA. THE LOCAL MOS IN BETWEEN THE TWO SEEMS TO BE A BETTER CHOICE...GIVEN SOME POTENTIAL FOR SUN. WITH THAT IN MIND...HIGHS WILL RANGE FROM THE LOWER 80S SOUTHEAST TO THE LOWER 70S IN THE SOUTHWEST WHERE STORMS ARRIVE/DEVELOP SOONER. TONIGHT...THE HEAVY RAIN THREAT SHOULD DIMINISH OVERNIGHT AS ONE AREA OF LIFT PUSHES OUT OF THE AREA. HOWEVER...MODELS SOLUTIONS ARE CONVERGING TOWARD ANOTHER ORGANIZED AREA OF SHOWERS/STORMS OVER SW VA AFTER MIDNIGHT...SO IF TRENDS CONTINUE TO SHOW THIS...MAY HAVE TO EXTEND THE FFA FURTHER IN TIME...AS IT RUNS TIL MIDNIGHT FOR NOW. LOWS TONIGHT WILL BE MILD AGAIN WITH LOWER TO MID 60 EAST TO MID 50S WEST. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 355 AM EDT TUESDAY... NOT TOO MUCH CHANGES THIS PERIOD...WITH UPPER TROUGH LINGER OVER THE AREA...AND SFC FRONT EAST OF THE FORECAST AREA. PATTERN STILL WILL REMAIN CONDUCIVE FOR SHOWER/STORM DEVELOPMENT ESPECIALLY IN THE AFTN. MODELS ARE CONVERGING AGAIN ON THE NORTHERN FORECAST AREA TO SEE MORE RAINFALL...AND KEPT POPS IN THE LIKELY RANGE ACROSS THIS AREA....WITH HIGH CHANCE SOUTH TO THE NC/VA COUNTIES. HIGHER PWATS WILL RESIDE OVER THE ERN CWA. AGAIN LOOKING AT MOSTLY CLOUD SKIES ALL DAY WHICH IS GOING TO LIMIT HEATING AND THE SVR THREAT SHOULD STAY ISOLATED...WITH HAIL POSSIBLE GIVEN UPPER COOL POOL OVER NC. EXPECT TO SEE POPS TAPER OFF THE LOW CHANCE TO LESS THAN 20 PERCENT WEST OF THE BLUE RIDGE AFTER MIDNIGHT WED NIGHT PER UPPER LOW SHIFTING EAST INTO THE VA PIEDMONT. THURSDAY LOOKS DRIER...BUT ANOTHER UPPER TROUGH SHIFTS FROM THE TENNESSEE VALLEY INTO GEORGIA AND UPPER FLOW AND DIVERGENCE...COMBINED WITH MODEST INSTABILITY SHOULD LEAD TO MORE OF A SCATTERING OF SHOWERS AND STORMS. SHOWERS AND STORMS SHOULD START TO WEAKEN THURSDAY NIGHT WITH LOSS OF HEATING. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 305 PM EDT MONDAY... THE MEDIUM RANGE MODELS AND ENSEMBLES ARE IN GOOD AGREEMENT BUILDING A STRONG UPPER RIDGE...FIRST OVER THE OHIO VALLEY...THEN ELONGATING INTO THE MID-ATLANTIC REGION SUNDAY INTO MONDAY. THIS WILL RESULT IN TEMPERATURES WELL ABOVE NORMAL AND LESS COVERAGE IN PRECIPITATION. ON FRIDAY...THE LINGERING UPPER LEVEL TROF FINALLY GETS PUSHED NORTHEAST BY A SHORTWAVE MOVING THROUGH THE GREAT LAKES. WITH A MOIST (GREATER THAN 1.5 PWATS) AND UNSTABLE AIR MASS IN PLACE AND WEAK LOW LEVEL CONVERGENCE AND THE SFC...WIDELY SCATTERED THUNDERSTORMS WILL AGAIN BE POSSIBLE. THE COVERAGE OF SHOWERS AND STORMS SHOULD DIMINISH THROUGH THE HOLIDAY WEEKEND AS THE UPPER RIDGE BUILDS. HOWEVER...WEAK...BUT FAIRLY DEEP EAST/SOUTHEAST UPSLOPE LOW LEVEL FLOW MAY BE ABOVE TO OVERCOME WARMING MID LEVEL TEMPS/RISING HEIGHTS TO INITIATE ISOLATED TO WIDELY SCT STORMS ALONG THE BLUE RIDGE. LEARNED TOWARD THE WARMER MEX GUIDANCE FOR TEMPS THROUGH THE LONG TERM PERIOD...WITH FORECAST HIGHS NEARING RECORDS FOR BLF. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 1245 PM EDT TUESDAY... MVFR CIGS ACROSS THE WEST FINALLY STARTING TO MIX OUT WITH HEATING...OTRW WILL CONTINUE VFR TRENDS OUTSIDE OF CONVECTION INTO LATE THIS AFTERNOON. CURRENT TSRA FORMING ON THE RIDGES...MAINLY OUTSIDE OF THE TAF SITES...BUT CLOSE ENOUGH PROXIMITY TO INCLUDE A VCTS AT KROA AND KLWB TO INIT. ELSW DELAYED COVERAGE A BIT BUT APPEARS AREAS ALONG/WEST OF THE BLUE RIDGE WILL START TO FILL IN WITH SHRA/TSRA GIVEN ADDED HEATING/OUTFLOW SO INCLUDING AT LEAST A VCSH OR VCTS MENTION MOST LOCATIONS FROM MID AFTERNOON INTO EARLY THIS EVENING. TSRA WILL AGAIN BE SLOW MOVING WITH POTENTIAL FOR ANY LOCATION TO QUICKLY LOWER TO IFR IN HEAVY RAINFALL AND LOWER CIGS. WINDS WILL REMAIN MOSTLY LIGHT AND VRBL BUT COULD GUSTS TO ABOVE 30-40 MPH NEAR ANY OF THE STORMS. WILL STILL SEE SOME COVERAGE OF CONVECTION HEADING INTO THE EVENING BUT SHOULD BE LESS...SO ONLY EXTENDED END TIME OUT AN HOUR OR TWO TO COVER POTENTIAL UNTIL SHORTLY AFTER SUNSET. AGAIN WILL BE A NIGHT SIMILAR TO LAST NIGHT WHERE CIGS/VSBYS COULD FLUCTUATE BETWEEN LIFR TO VFR AT TIMES...SO WENT TOWARD MIDDLE ROUTE OF IFR...MAINLY WITH FOG INSTEAD OF LOWER CIGS. ANY LOCATION THAT DOES SEE HEAVY RAIN COULD DROP INTO LIFR AFTER MIDNIGHT AND NOT SEE MUCH IMPROVEMENT UNTIL MID MORNING WEDNESDAY. WEDNESDAY WILL BE A REPEAT OF TODAY WITH MOST COVERAGE OF STORMS SHIFTING NORTH OF A LINE FROM BLF-LYH. MAINLY VFR AFTER MORNING FOG/LOWER CLOUDS EXCEPT IN HEAVIER TSRA. LOOKING AT THE PATTERN SHIFTING TOWARD THE END OF THE WEEK...AND UNTIL FRIDAY SHOULD SEE NIGHTTIME THREAT OF LOWER CIGS/FOG AND DAYTIME THUNDER. BY FRIDAY WILL SEE HIGH PRESSURE WORKING IN TO BRING VFR WX...AND TEMPERATURES HEAT UP. NIGHLTY FOG IN THE VALLEYS BCB/LWB A GOOD POSSIBILITY GIVEN THE GROUND SHOULD BE MOIST...WITH LITTLE WIND. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ007- 009>020-022>024. NC...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR NCZ001-002- 018. WV...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR WVZ042>045. && $$ SYNOPSIS...JH/PW/WP NEAR TERM...JH/WP SHORT TERM...PH/WP LONG TERM...PH AVIATION...JH/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1026 AM EDT TUE MAY 22 2012 .SYNOPSIS... A COLD FRONT SLOWLY PUSHES EAST ACROSS THE AREA THIS AFTERNOON...AND THEN TO THE COAST BY LATE WEDNESDAY. SHOWERS AND THUNDERSTORMS...WITH SOME POTENTIALLY BRINGING HEAVY RAIN...WILL BE POSSIBLE THROUGH THURSDAY. HIGH PRESSURE AND DRIER WEATHER WILL ARRIVE LATE IN THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 945 AM EDT TUESDAY... WEAK FRONT EDGING INTO THE FAR WESTERN SECTIONS THIS MORNING LOOKS TO BE THE MAIN FOCUS FOR DEEPER AFTERNOON CONVECTION ESPCLY ACROSS THE MOUNTAINS NEAR THE EDGE OF THE CLOUD CANOPY TO THE WEST ATTM. LATEST MODIFIED MORNING RAOBS SHOW 1500-2K J/KG CAPES PROVIDED ENOUGH HEATING THIS AFTERNOON UNDER LIGHT STEERING PER A MEAN FLOW OF 6-10 KTS. THIS SHOULD AGAIN SPELL SLOW MOVING CLUSTERS OF STORMS ESPCLY MOUNTAINS WITH A FEW OF THESE PERHAPS GOING SEVERE WITH DOWNBURST POTENTIAL PER DECENT WINDEX VALUES...AND SOME HAIL GIVEN LOW WET BULB VALUES OFF MORNING SOUNDINGS. HOWEVER WITH SUCH A MID LEVEL CAP SEEN THIS MORNING MAY TAKE THINGS A LITTLE LONGER TO DEVELOP WITH BETTER FOCUS LATER ON WEST AS THE UPPER LOW STARTS TO LIFT NE ALONG THE SRN APPALACHIANS. THUS MAIN CHANGES WERE TO SLOW DOWN ONSET OF CONVECTION THIS MORNING AND THEN INCREASE POPS SOME WEST WHERE KEEPING HEAVY RAIN MENTION/WATCH IN PLACE. THIS SUPPORTED BY EXPANSIVE COVERAGE OFF BOTH THE LATEST HRRR AND LOCAL WRF MODELS AFTER MIDDAY INTO EARLY THIS EVENING. EXTENT OF TSRA COVERAGE A BIT MORE IFFY E/SE GIVEN LESS SUPPORT AND MORE OUTFLOW DRIVEN...BUT EXPECT HIGH CAPES AND EVENTUAL SPILLING OF WESTERN CONVECTION TO SUPPORT LIKELY POPS THERE. RAISED HIGH TEMPS SLIGHTLY ALONG THE BLUE RIDGE WHERE SHOULD SEE MORE SUN EARLY OTRW 70S WEST TO LOW 80S EAST APPEAR ON TRACK. AS OF 615 AM EDT TUESDAY... UPDATE TO DROP POPS SOME THIS MORNING GIVEN RADAR TRENDS. WILL SEE INCREASE IN COVERAGE AGAIN OVER THE MTNS BY LATE MORNING. DECREASED CLOUD COVERAGE EARLY AS WELL ESPECIALLY THE SRN CWA. PREVIOUS DISCUSSION AT 355 AM... ECHOES ON RADAR WEAKENING AS EXPECTED BUT NOT SURPRISED THAT SHOWERS HAVE LINGERED ALL NIGHT...PER HIGHER THETA-E AIR AND LINGERING BOUNDARIES AND UPPER SUPPORT. TODAY WILL BE ANOTHER STORMY ONE FOR THE AREA AND EXPECT MORE COVERAGE OF SHOWERS AND STORMS. GIVEN THE RAINFALL OVER THE MOUNTAINS THAT LAST FEW DAYS AND LOWER FFG VALUES COMBINED WITH A PATTERN CONDUCIVE TO SLOW MOVING STORMS AND HIGH PWATS...HAVE WENT AHEAD AN ISSUED A FLASH FLOOD WATCH FOR AREAS ALONG AND WEST OF THE BLUE RIDGE. THE FOCUS TODAY WILL BE ACROSS THE MOUNTAINS WHERE BEST UPPER DIFFLUENCE IS EXPECTED WITH UPPER TROUGH. AT THE SFC...COLD FRONT WILL BE EDGING EWD TO THE BLUE RIDGE BY EVENING WITH SEVERAL WEAK LOWS MOVING ALONG IT. WITH EXTENSIVE CLOUD COVER...NOT EXPECT A WIDESPREAD THREAT FOR SVR BUT WITH MOIST AIRMASS...AND COLDER AIR ALOFT WITH THE UPPER TROUGH...WOULD NOT BE SURPRISED THAT SOME STORMS BECOME STRONG TO SEVERE WITH ISOLATED LARGE HAIL/MICROBURST THREAT. WINDS ALOFT ARE WEAK...SO WOULD HAVE TO BE ENOUGH RAIN LOADING IN THE STORM TO BRING DAMAGING WINDS. WILL HAVE HIGHER POPS THIS AFTERNOON WITH CATEGORICAL ACROSS THE BLUE RIDGE AND WEST. WITH MOIST AIRMASS AND LESS SUN WILL SEE HIGHS IN BETWEEN THE COOLER MET/WARMER MAV...ALTHOUGH COOLER MET MAY HAVE A BETTER IDEA. THE LOCAL MOS IN BETWEEN THE TWO SEEMS TO BE A BETTER CHOICE...GIVEN SOME POTENTIAL FOR SUN. WITH THAT IN MIND...HIGHS WILL RANGE FROM THE LOWER 80S SOUTHEAST TO THE LOWER 70S IN THE SOUTHWEST WHERE STORMS ARRIVE/DEVELOP SOONER. TONIGHT...THE HEAVY RAIN THREAT SHOULD DIMINISH OVERNIGHT AS ONE AREA OF LIFT PUSHES OUT OF THE AREA. HOWEVER...MODELS SOLUTIONS ARE CONVERGING TOWARD ANOTHER ORGANIZED AREA OF SHOWERS/STORMS OVER SW VA AFTER MIDNIGHT...SO IF TRENDS CONTINUE TO SHOW THIS...MAY HAVE TO EXTEND THE FFA FURTHER IN TIME...AS IT RUNS TIL MIDNIGHT FOR NOW. LOWS TONIGHT WILL BE MILD AGAIN WITH LOWER TO MID 60 EAST TO MID 50S WEST. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 355 AM EDT TUESDAY... NOT TOO MUCH CHANGES THIS PERIOD...WITH UPPER TROUGH LINGER OVER THE AREA...AND SFC FRONT EAST OF THE FORECAST AREA. PATTERN STILL WILL REMAIN CONDUCIVE FOR SHOWER/STORM DEVELOPMENT ESPECIALLY IN THE AFTN. MODELS ARE CONVERGING AGAIN ON THE NORTHERN FORECAST AREA TO SEE MORE RAINFALL...AND KEPT POPS IN THE LIKELY RANGE ACROSS THIS AREA....WITH HIGH CHANCE SOUTH TO THE NC/VA COUNTIES. HIGHER PWATS WILL RESIDE OVER THE ERN CWA. AGAIN LOOKING AT MOSTLY CLOUD SKIES ALL DAY WHICH IS GOING TO LIMIT HEATING AND THE SVR THREAT SHOULD STAY ISOLATED...WITH HAIL POSSIBLE GIVEN UPPER COOL POOL OVER NC. EXPECT TO SEE POPS TAPER OFF THE LOW CHANCE TO LESS THAN 20 PERCENT WEST OF THE BLUE RIDGE AFTER MIDNIGHT WED NIGHT PER UPPER LOW SHIFTING EAST INTO THE VA PIEDMONT. THURSDAY LOOKS DRIER...BUT ANOTHER UPPER TROUGH SHIFTS FROM THE TENNESSEE VALLEY INTO GEORGIA AND UPPER FLOW AND DIVERGENCE...COMBINED WITH MODEST INSTABILITY SHOULD LEAD TO MORE OF A SCATTERING OF SHOWERS AND STORMS. SHOWERS AND STORMS SHOULD START TO WEAKEN THURSDAY NIGHT WITH LOSS OF HEATING. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 305 PM EDT MONDAY... THE MEDIUM RANGE MODELS AND ENSEMBLES ARE IN GOOD AGREEMENT BUILDING A STRONG UPPER RIDGE...FIRST OVER THE OHIO VALLEY...THEN ELONGATING INTO THE MID-ATLANTIC REGION SUNDAY INTO MONDAY. THIS WILL RESULT IN TEMPERATURES WELL ABOVE NORMAL AND LESS COVERAGE IN PRECIPITATION. ON FRIDAY...THE LINGERING UPPER LEVEL TROF FINALLY GETS PUSHED NORTHEAST BY A SHORTWAVE MOVING THROUGH THE GREAT LAKES. WITH A MOIST (GREATER THAN 1.5 PWATS) AND UNSTABLE AIR MASS IN PLACE AND WEAK LOW LEVEL CONVERGENCE AND THE SFC...WIDELY SCATTERED THUNDERSTORMS WILL AGAIN BE POSSIBLE. THE COVERAGE OF SHOWERS AND STORMS SHOULD DIMINISH THROUGH THE HOLIDAY WEEKEND AS THE UPPER RIDGE BUILDS. HOWEVER...WEAK...BUT FAIRLY DEEP EAST/SOUTHEAST UPSLOPE LOW LEVEL FLOW MAY BE ABOVE TO OVERCOME WARMING MID LEVEL TEMPS/RISING HEIGHTS TO INITIATE ISOLATED TO WIDELY SCT STORMS ALONG THE BLUE RIDGE. LEARNED TOWARD THE WARMER MEX GUIDANCE FOR TEMPS THROUGH THE LONG TERM PERIOD...WITH FORECAST HIGHS NEARING RECORDS FOR BLF. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... AS OF 715 AM EDT TUESDAY... ANY FOG/LOWER CIGS WILL BE LIFTING SOON AND SHOULD SEE MAINLY VFR CONDITIONS TODAY OUTSIDE OF STORMS. THE STORMS SHOULD FORM AGAIN BY MIDDAY OVER THE MOUNTAINS WITH SLOW MOVEMENT...THEN STORMS WILL BE FORMING ALONG/EAST OF THE BLUE RIDGE TOWARD 18Z-21Z. THE BEST COVERAGE TODAY SHOULD BE ALONG/WEST OF THE BLUE RIDGE...AND WILL SEE HEAVY RAINS FROM THESE STORMS. GIVEN THE NATURE OF THIS PATTERN...KEPT TAFS LOW END VFR. WILL STILL SEE SOME COVERAGE OF CONVECTION HEADING INTO THE EVENING BUT SHOULD BE LESS...SO TOOK IT ALL OUT OF TAFS. AGAIN WILL BE A NIGHT SIMILAR TO THIS MORNING WHERE CIGS/VSBYS COULD FLUCTUATE BETWEEN LIFR TO VFR AT TIMES...SO WENT TOWARD MIDDLE ROUTE OF IFR...MAINLY WITH FOG INSTEAD OF LOWER CIGS. WEDNESDAY WILL BE A REPEAT OF TODAY WITH MOST COVERAGE OF STORMS SHIFTING NORTH OF A LINE FROM BLF-LYH. MAINLY VFR AFTER MORNING FOG/LOWER CLOUDS EXCEPT IN HEAVIER TSRA. LOOKING AT THE PATTERN SHIFTING TOWARD THE END OF THE WEEK...AND UNTIL FRIDAY SHOULD SEE NIGHTTIME THREAT OF LOWER CIGS/FOG AND DAYTIME THUNDER. BY FRIDAY WILL SEE HIGH PRESSURE WORKING IN TO BRING VFR WX...AND TEMPERATURES HEAT UP. NIGHLTY FOG IN THE VALLEYS BCB/LWB A GOOD POSSIBILITY GIVEN THE GROUND SHOULD BE MOIST...WITH LITTLE WIND. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR VAZ007-009>020- 022>024. NC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR NCZ001-002-018. WV...FLASH FLOOD WATCH THROUGH THIS EVENING FOR WVZ042>045. && $$ SYNOPSIS...PW/WP NEAR TERM...JH/WP SHORT TERM...PH/WP LONG TERM...PH AVIATION...WP
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
534 PM CDT TUE MAY 22 2012 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE .SHORT TERM...TONIGHT AND WEDNESDAY. THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE STRETCHING FROM THE SOUTHERN GREAT PLAINS AND ACROSS THE CENTRAL GREAT LAKES TO HUDSON BAY. A WARM FRONT HAS BEEN DEVELOPING TODAY OVER THE FAR NORTHERN PLAINS AND OVER WESTERN LAKE SUPERIOR TO THE UPPER PENINSULA. WARM/MOIST ADVECTION NORTH OF THE BOUNDARY IS CONTRIBUTING TO SCT LIGHT SHOWERS AND ISOLATED THUNDERSTORMS FROM NORTHERN MINNESOTA TO THE WESTERN UPPER PENINSULA. SOME RETURNS ARE GRAZING THE U.P. BORDER THIS AFTERNOON...BUT NO CONFIRMATION OF THESE RETURNS REACHING THE GROUND AT IRONWOOD OR LAND O LAKES. THE AIRMASS IS PRETTY DRY IN THIS AREA WITH DEWPOINTS AT LAND O LAKES IN THE LOWER 30S. AS LOW PRESSURE OVER WESTERN NORTH DAKOTA MOVES NORTHEAST...A COLD FRONT WILL MOVE TO THE UPPER MISSISSIPPI VALLEY TOMORROW. WITHOUT MUCH IMPACT YET...CLOUDS AND TEMPS WILL BE THE MAIN FORECAST CONCERNS. TONIGHT...HIGH PRESSURE OVER THE CENTRAL GREAT LAKES TO START THE EVENING WILL SHIFT TO THE EASTERN GREAT LAKES OVERNIGHT. LOW PRESSURE WILL MOVE NORTHEAST OVER THE PLAINS TONIGHT...BUT ITS WARM FRONT WILL REMAIN RELATIVELY STATIONARY OVER THE SOUTH SHORELINE OF LAKE SUPERIOR. WARM/MOIST ADVECTION THAT IS OCCURRING OVER THE ARROWHEAD OF MINNESOTA AND THE UPPER PENINSULA WILL BE LIFTING OFF TO THE NORTHEAST GRADUALLY AS HEIGHTS BUILD ALOFT...EVEN THOUGH CORFIDI VECTORS TRACK THE INDIVIDUAL SHOWERS OFF TO THE SOUTHEAST. THINK THERE IS POTENTIAL FOR THIS SHOWER ACTIVITY TO GRAZE THE U.P.-WISCONSIN BORDER THROUGH 00Z. HOWEVER...LOW LEVELS ARE VERY DRY...SO WILL LEAVE IT AS A CHANCE OF SPRINKLES. RECENT RADAR TRENDS ALREADY SHOW THE BACK EDGE OF THE PRECIP LIFTING NE OVER THE ARROWHEAD...SO AM COUNTING ON THIS TREND KEEPING THE BORDER DRY AFTER 00Z. MID AND UPPER CLOUDS WILL BE LIFTING OFF TO THE NE AS WELL SO SHOULD SEE DECREASING CLOUDS THROUGH THE NIGHT OVER THE NORTH. THE PRESSURE GRADIENT WILL BE TIGHTENING TONIGHT...WHICH WILL KEEP LOWS WARMER THAN LAST NIGHT. WILL GO WITH MID TO UPPER 40S FOR LOWS. WEDNESDAY...UPSTREAM COLD FRONT WILL MOVE INTO THE NORTHERN MISSISSIPPI VALLEY DURING THE AFTERNOON. WITH THE AREA FIRMLY IN THE WARM SECTOR...WILL HAVE MID AND UPPER CLOUDS NORTH AND WEST OF THE REGION...BUT SHOULD SEE MOSTLY CLEAR TO PARTLY CLOUDY SKIES FOR THE DAY. THE PRESSURE GRADIENT WILL TIGHTEN AHEAD OF THE FRONT...AND SOUTH WINDS WILL TURN GUSTY WITH DAYTIME HEATING AND MIXING. SOME GUSTS COULD REACH 30 OR MAYBE EVEN 35 MPH. HIGHS TOMORROW IN THE MID 70S TO LOW 80S. .LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY. ONE OF THE FORECAST CHALLENGES FOR THIS PERIOD IS TRYING TO LASSO IN THE LOCATIONS OF THE FRONT FOR THE MEMORIAL DAY WEEKEND. ANOTHER ISSUE IS TIMING AND STRENGTH OF A SHORT WAVE TROUGH FOR LATER THURSDAY AND ESPECIALLY THURSDAY NIGHT. LITTLE CHANGE FROM THE GOING FORECAST FROM 24 HOURS AGO FROM WEDNESDAY NIGHT INTO THURSDAY AS A SURFACE HIGH PRESSURE WITH UPPER RIDGE DRIFTING OVER THE AREA WILL CONTINUE TO PROVIDE QUIET WEATHER TO THE AREA. MODELS CONTINUE TO CONFINE CONVECTION OVER THE NORTHERN PLAINS WITH THE BROAD UPPER TROUGH. PWATS GRADUALLY INCREASE TO 1.75 ALONG THE FRONT OVER THE NORTHERN PLAINS. UNTIL THIS UPPER RIDGE IS NUDGED FAR ENOUGH EAST...WILL CONTINUE TO CONFINE ANY SMALL PCPN MENTION AND CLOUDS WEST OF A RHI TO AUW LINE. WILL THEN FOCUS ON HIGHER POPS FOR THE THURSDAY AFTERNOON INTO THURSDAY NIGHT PERIOD AS A SHORT WAVE SLIDES OVER THE STATE. A SURFACE LOW AND UPPER JET COUPLET PROGGED TO AFFECT THE NORTH HALF OF THE STATE DURING THIS PERIOD PROVIDES SOME POTENTIAL OF STRONG TO SEVERE STORMS. PROGS ARE A BIT MORE PROGRESSIVE WITH THE FRONTAL PASSAGE LATE THURSDAY NIGHT. USING THE H8 FRONT...THE FRONT IS DRIVEN SOUTH OF THE AREA FRIDAY INTO FRIDAY NIGHT FOR A DIMINISHED PERIOD OF CONVECTION. PROGS IN GOOD AGREEMENT WITH H8 WARM FRONT LIFTING BACK NORTH AGAIN ON SATURDAY SO INCREASED CONVECTION INCLUDING THUNDER FROM SOUTH TO NORTH DURING THE DAY. PROGS CONTINUE TO LIFT THE FRONT NORTH TO GRADUALLY DIMINISH CONVECTION OVER CENTRAL AND EAST CENTRAL WISCONSIN BUT WILL CONFINE BEST PCPN CHANCES ACROSS THE NORTH SUNDAY AND PERHAPS INTO MONDAY CLOSER TO THE WARM FRONT. AREAS TO THE SOUTH LIKELY TO BE CAPPED IN A VERY WARM HUMID AIR MASS AS UPPER HEIGHTS BUILD. ANOTHER FRONT IS PROGGED TO SLIDE OVER MONDAY INTO MONDAY NIGHT FOR ANOTHER SHOT OF CONVECTION. PWATS INCREASE TO 1.70 INCHES ALONG THE FRONT...HOWEVER AT THIS TIME IT APPEARS THE FRONTS ARE A LITTLE TOO PROGRESSIVE FOR HEAVY RAINS TO CONCENTRATE IN ANY ONE LOCATION WITH THE EXCEPTION OF THE FAR NORTH NEAR THE WARM FRONT. && .AVIATION...FOR 00Z TAF ISSUANCE. VFR CONDITIONS EXPECTED TNGT AND WED AS SFC RIDGE SLIDES AWAY TO THE SE AND FRONTAL SYSTEM STARTS TO ADVANCE E FM THE PLAINS. MAIN FCST ISSUE IS LLWS POTENTIAL TNGT. RAP CONSIDERABLY STRONGER WITH WINDS 1-2K FT IN C/N-C WI THAN THE NAM...AND THE NAM IS NORMALLY ON THE HIGH END OF THE GUID WITH LOW-LEVEL WINDS. CONSIDERABLE SPREAD AMONG SREF MEMBERS AS WELL. OVERALL...SREF SEEMS TO LEND ENOUGH SUPPORT TO INCLUDE LLWS IN THE WRN TAF SITES...BUT AS LEVELS BLO THOSE SHOWN ON RAP FCST SOUNDINGS. SKOWRONSKI && .MARINE...A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED LATE WEDNESDAY AFTERNOON INTO THURSDAY NIGHT. INCREASING SOUTH WINDS ARE EXPECTED ON WEDNESDAY...THEN STRONG SOUTH WINDS ARE EXPECTED ON THURSDAY. A FEW GUSTS COULD APPROACH GALE FORCE NEAR THE SHORELINE THURSDAY AFTERNOON. WINDS AND WAVES WILL GRADUALLY SUBSIDE THURSDAY NIGHT. FOR THE UPCOMING MEMORIAL DAY WEEKEND...IT WILL BE UNSETTLED AS THERE WILL BE CHANCES FOR THUNDERSTORMS EACH DAY. A WARM FRONT IS EXPECTED TO SLOWLY PUSH NORTHWARD INTO THE AREA OVER THE WEEKEND. THERE IS A LOT OF UNCERTAINTY ON HOW FAR NORTH THE WARM FRONT WILL MAKE IT INTO NORTHEAST WISCONSIN AND WHERE THE BEST CHANCES FOR THUNDERSTORMS WOULD OCCUR. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
303 PM CDT TUE MAY 22 2012 .SHORT TERM...TONIGHT THROUGH FRIDAY 303 PM CDT TUE MAY 22 2012 MAIN FORECAST CONCERNS ARE WHEN PRECIPITATION CHANCES MOVE INTO THE AREA AND SEVERE WEATHER POTENTIAL FOR THURSDAY. CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED TROUGHING OVER SOUTHWEST CANADA AND THE NORTHERN ROCKIES... WITH RIDGING BUILDING DOWNSTREAM OVER THE UPPER MISSISSIPPI RIVER VALLEY REGION. A SHORTWAVE EJECTING OUT OF THE TROUGHING AND DOWNSLOPING UPPER FLOW OFF THE ROCKIES HAS LED TO LOW PRESSURE DEVELOPMENT OVER THE DAKOTAS. INCREASING SOUTHERLY FLOW DOWNSTREAM OF THIS SURFACE LOW ON THE ORDER OF 20-40KT 850MB WINDS PER PROFILER DATA IS SPREADING WARMER AIR NORTHWARD. MODIFYING THROUGH ADVECTION AND DAYTIME HEATING PROCESSES FROM 12Z RAOBS...THE RAP SUGGESTS 850MB TEMPS HAVE RISEN TO 10-14C OVER THE FORECAST AREA. WITH PLENTY OF SUN AND THE INCREASING WINDS...SURFACE TEMPERATURES HAVE CLIMBED INTO THE 70S TO LOW 80S. FARTHER WEST...THE 850MB TEMPS INCREASE TO 18-25C OR HIGHER OVER MUCH OF THE PLAINS. MOISTURE IS ALSO RETURNING...MORE OVER THE PLAINS...WHERE SURFACE DEWPOINTS ARE MOSTLY IN THE 50S. TONIGHT AND WEDNESDAY...TROUGHING OVER THE NORTHERN ROCKIES IS FORECAST TO DEEPEN ACROSS THE WESTERN U.S....RESULTING IN STRENGTHENING RIDGING DOWNSTREAM INTO THE GREAT LAKES. A COUPLE OF SHORTWAVES EJECTING OUT OF THIS TROUGHING WILL HELP LIFT THE LOW IN THE DAKOTAS INTO FAR NORTHWEST ONTARIO...DRAGGING A COLD FRONT INTO WESTERN MINNESOTA BY 00Z. INCREASING SOUTH TO SOUTHWEST FLOW ALOFT AHEAD OF THE FRONT WILL HELP BRING WARMER AIR INTO THE FORECAST AREA WITH 850MB TEMPS CLIMBING TO AT LEAST 16-18C BY 18Z WEDNESDAY. WE SHOULD ALSO SEE AN INCREASE IN ALTOSTRATUS AND CIRROSTRATUS... ALREADY EVIDENT OVER EASTERN MONTANA AND WYOMING. THESE CLOUDS MAY TEMPER HIGHS SOMEWHAT...BUT READINGS SHOULD EASILY REACH INTO THE 80S GIVEN THE STRENGTH OF THE WARM ADVECTION/WINDS AND SUN. LOWS TONIGHT ALSO EXPECTED TO BE WARMER WITH THE INCREASING WINDS... ESPECIALLY ACROSS SOUTHEAST MINNESOTA. REGARDING PRECIPITATION CHANCES...ANY CONVECTION SHOULD BE STRONGLY TIED TO THE FRONT. AHEAD OF THE FRONT...MODELS SUGGEST QUITE A BIT OF CIN...EVEN WITH THEIR HIGHER SURFACE DEWPOINTS LIKE THE NAM SUGGESTS. THERE IS ALSO MIX DOWN POTENTIAL OF THE DEWPOINTS WITH PLENTIFUL DRY AIR BELOW 700MB. THEREFORE...THINKING THE ENTIRE FORECAST AREA SHOULD BE DRY THROUGH WEDNESDAY. LAST ITEM OF NOTE IS WINDS COULD GET CLOSE TO ADVISORY CRITERIA IN SOUTHEAST MN LATE IN THE MORNING INTO MID AFTERNOON... JUST BASED ON THE SPEEDS THEMSELVES. SOMETHING TO WATCH. WEDNESDAY NIGHT AND THURSDAY...AT THE BASE OF THE DEEPENING WESTERN TROUGH...A NEW SURFACE LOW SHOULD HAVE DEVELOPED OVER FAR SOUTHEAST COLORADO BY 00Z THURSDAY. THIS SURFACE LOW IS EXPECTED TO LIFT NORTHEAST...ALONG THE COLD FRONT THAT MOVED INTO WESTERN MINNESOTA LATE WEDNESDAY...DUE TO ANOTHER COLLECTION OF SHORTWAVES EJECTING OUT OF THE WESTERN TROUGH. THEREFORE...THE FRONT WEDNESDAY NIGHT IS LIKELY TO NOT MAKE MUCH IF ANY PROGRESS EASTWARD. IN FACT...WE NEED TO WAIT UNTIL THE LOW MOVES NORTH OF THE AREA TO DRIVE THE COLD FRONT EASTWARD. THIS DRIVE EASTWARD TOO WILL BE ENHANCED BY A FAIRLY POTENT SHORTWAVE COMING UP INTO MINNESOTA. FOR WEDNESDAY NIGHT... AGAIN CONVECTION SHOULD REMAIN TIED AROUND THE COLD FRONT IN MINNESOTA. VARIOUS THINGS GOING FOR CONVECTION INCLUDE A RIGHT ENTRANCE REGION OF A JET LIFTING OUT OF THE DAKOTAS...INCREASING LOW TO MID-LEVEL FRONTOGENESIS ON THE COLD FRONT...AND A PLUME OF 500-1000 J/KG OF MUCAPE BEING TRANSPORTED INTO THE FRONTOGENESIS ZONE BY A STRENGTHENING LOW LEVEL JET. AS IT STANDS RIGHT NOW...MOST MODELS SUGGEST THE FRONT AND BULK OF CONVECTION WILL END UP WEST OF THE FORECAST AREA. HAVE MAINTAINED SOME CHANCES OVER THE NORTHWEST ENDS...THOUGH...AS CONVECTIVE OUTFLOWS MAY TRY TO PUSH THE FRONT EASTWARD. THURSDAY IS DEFINITELY MORE CONCERNING AS THE POTENT SHORTWAVE APPROACHES IN THE AFTERNOON. SOME SLIGHT TIMING DIFFERENCES EXIST ON THE COLD FRONTAL PASSAGE AND APPROACH OF THE SHORTWAVE...BUT THERE IS GOOD AGREEMENT THAT THE DYNAMICAL AND THERMODYNAMICAL FORCING WILL LIKELY LEAD TO A SQUALL LINE ALONG THE FRONT EARLY TO MID AFTERNOON...ALONG WITH POST-FRONTAL PRECIPITATION. THIS PRECIPITATION THEN PUSHES EAST INTO THE EVENING. RAISED PRECIPITATION CHANCES TO 50-70 FOR THE AFTERNOON. PLENTIFUL 0-6 KM AND 0-3KM SHEAR AND MLCAPE OF 500-1000 J/KG SHOULD BE ENOUGH TO PRODUCE SOME SEVERE WEATHER...WITH DAMAGING WINDS MAIN HAZARD. TEMPERATURES LIKELY TO STAY WARM WEDNESDAY NIGHT AND THURSDAY DUE TO BREEZY WINDS...WITH A POSSIBLE FALL IN TEMPERATURES IN THE AFTERNOON AS THE FRONT/PRECIPITATION MOVE THROUGH. WINDS COULD GET CLOSE TO ADVISORY CRITERIA ON THURSDAY. THURSDAY NIGHT AND FRIDAY...AFTER THE SQUALL LINE AND COLD FRONT MOVE THROUGH IN THE EVENING...STRONG SUBSIDENCE IS INDICATED TO MOVE INTO THE FORECAST AREA. RAISED PRECIPITATION CHANCES EAST OF THE MISSISSIPPI RIVER TO 50-70 TO HANDLE THE SQUALL LINE. CONDITIONS SHOULD THEN DRY OUT AFTER MIDNIGHT THANKS TO THE SUBSIDENCE... PRODUCED MOSTLY BY THAT POTENT SHORTWAVE WHICH LIFTS INTO UPPER MICHIGAN. THE COLD FRONT LOOKS TO STALL OVER NORTHERN MISSOURI FRIDAY MORNING. NEW DEEPER TROUGHING THEN FORMS IN THE WESTERN U.S....CAUSING RIDGING TO RE-BUILD DOWNSTREAM INTO THE MID-MISSISSIPPI VALLEY. DEPENDING ON THIS TIMING OF THE RIDGING BUILDING UP...THE FRONT MAY START MOVING BACK NORTH IN THE AFTERNOON...AS INDICATED IN THE 22.12Z NAM/GEM. MOISTURE TRANSPORT OVER THIS FRONT COULD LEAD TO A FEW SHOWERS AND THUNDERSTORMS OVER NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN...THOUGH DEFINITELY BETTER CHANCES WOULD BE OVER SOUTHERN IOWA CLOSER TO THE FRONT. COOLER AIR ADVECTING IN BEHIND THE FRONT SHOULD HELP SEND TEMPERATURES BACK DOWN TO SEASONABLE LEVELS. .LONG TERM...FRIDAY NIGHT THROUGH TUESDAY 303 PM CDT TUE MAY 22 2012 MODELS AND GFS ENSEMBLES ARE INCREASINGLY BECOMING IN GOOD AGREEMENT FOR THE WEEKEND...INDICATING TROUGHING TO PERSIST OVER THE WESTERN U.S. WHILE STRONG SUBTROPICAL RIDGING BUILDS OVER THE EASTERN TWO THIRDS OF THE COUNTRY. WITH THIS BUILDING RIDGING...THE WARM FRONT ON FRIDAY SITUATED EITHER OVER SOUTHERN IOWA OR NORTHERN MISSOURI WILL GRADUALLY LIFT NORTH ACROSS THE FORECAST AREA. THE SPEED OF THIS MAY BE MODULATED BY PERIODS OF CONVECTION FORMING ON THE WARM FRONTAL BOUNDARY...IN RESPONSE TO FRONTOGENESIS AND ESPECIALLY INCREASING LOW LEVEL JET/MOISTURE TRANSPORT AT NIGHT. BEST TIME PERIOD FOR CONVECTION ACROSS THE AREA WOULD PROBABLY BE FRIDAY NIGHT INTO SATURDAY MORNING. SATURDAY NIGHT INTO SUNDAY MORNING COULD OCCUR TOO OVER FAR NORTHERN PORTIONS OF THE AREA...DEPENDING ON HOW FAR NORTH THE WARM FRONT REACHES. EITHER ROUND OF CONVECTION COULD BE SEVERE...GIVEN 1-6 KM SHEAR VALUES OF 40KT OR MORE AND LIKELY PLENTY OF INSTABILITY BEING ADVECTED OVER THE FRONTAL ZONE. ONCE THE WARM FRONT PASSES...850MB TEMPS JUMP TO 20C OR HIGHER. SUNDAY LOOKS TO BE THE WARM DAY WITH TEMPERATURES LIKELY WELL INTO THE 80S...PERHAPS EVEN 90S. THINGS GET A LITTLE MORE MURKY FOR EARLY NEXT WEEK...IN PARTICULAR WITH THE HANDLING OF THE WESTERN TROUGH. THE 22.00Z/22.12Z ECMWF/GEM AND SOME OF THE 22.12Z GFS ENSEMBLES SUGGEST THE WESTERN TROUGH WILL BE SLOWER TO EJECT NORTHEASTWARD THAN THE 22.12Z GFS AND THE REST OF ITS ENSEMBLES. THIS SEEMS REASONABLE GIVEN THE STRENGTH OF THE RIDGING AHEAD OF THE TROUGH. THEREFORE...LIKELY THE COLD FRONT ASSOCIATED WITH THE TROUGH WILL BE SLOWER TO MOVE THROUGH THE FORECAST AREA. THIS RESULTS IN A WARMER DAY ON MONDAY THAN WHAT THE GFS WOULD SUGGEST. TUESDAY WOULD BE COOLER AFTER THE FRONTAL PASSAGE. DID MAINTAIN THE CONSENSUS APPROACH FOR PRECIPITATION CHANCES MONDAY THROUGH TUESDAY...GIVEN THE DIFFERENCES. && .AVIATION...THROUGH 18Z WEDNESDAY 1233 PM CDT TUE MAY 22 2012 MAIN CONCERN THROUGH THE PERIOD WILL BE INCREASING SOUTH WINDS...ESPECIALLY DURING THE DAY WEDNESDAY AS A LOW AND COLD FRONT APPROACH FROM THE NORTHERN PLAINS. SCATTERED SHOWERS AND THUNDERSTORMS WILL BE SEEN ALONG AND AHEAD OF THIS APPROACHING FRONT...BUT ARE EXPECTED TO REMAIN WEST OF THE FORECAST AREA. PLAN ON SOME MID/HIGH LEVEL CLOUD DEBRIS FROM THIS SCATTERED CONVECTION TO DRIFT OVER THE KRST/KLSE TAF SITES...OTHERWISE VFR CONDITIONS WILL PREVAIL TONIGHT THROUGH MIDDAY WEDNESDAY. && .ARX WATCHES/WARNINGS/ADVISORIES... 303 PM CDT TUE MAY 22 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...DAS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
243 PM CDT TUE MAY 22 2012 .SHORT TERM...TONIGHT AND WEDNESDAY. THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE STRETCHING FROM THE SOUTHERN GREAT PLAINS AND ACROSS THE CENTRAL GREAT LAKES TO HUDSON BAY. A WARM FRONT HAS BEEN DEVELOPING TODAY OVER THE FAR NORTHERN PLAINS AND OVER WESTERN LAKE SUPERIOR TO THE UPPER PENINSULA. WARM/MOIST ADVECTION NORTH OF THE BOUNDARY IS CONTRIBUTING TO SCT LIGHT SHOWERS AND ISOLATED THUNDERSTORMS FROM NORTHERN MINNESOTA TO THE WESTERN UPPER PENINSULA. SOME RETURNS ARE GRAZING THE U.P. BORDER THIS AFTERNOON...BUT NO CONFIRMATION OF THESE RETURNS REACHING THE GROUND AT IRONWOOD OR LAND O LAKES. THE AIRMASS IS PRETTY DRY IN THIS AREA WITH DEWPOINTS AT LAND O LAKES IN THE LOWER 30S. AS LOW PRESSURE OVER WESTERN NORTH DAKOTA MOVES NORTHEAST...A COLD FRONT WILL MOVE TO THE UPPER MISSISSIPPI VALLEY TOMORROW. WITHOUT MUCH IMPACT YET...CLOUDS AND TEMPS WILL BE THE MAIN FORECAST CONCERNS. TONIGHT...HIGH PRESSURE OVER THE CENTRAL GREAT LAKES TO START THE EVENING WILL SHIFT TO THE EASTERN GREAT LAKES OVERNIGHT. LOW PRESSURE WILL MOVE NORTHEAST OVER THE PLAINS TONIGHT...BUT ITS WARM FRONT WILL REMAIN RELATIVELY STATIONARY OVER THE SOUTH SHORELINE OF LAKE SUPERIOR. WARM/MOIST ADVECTION THAT IS OCCURRING OVER THE ARROWHEAD OF MINNESOTA AND THE UPPER PENINSULA WILL BE LIFTING OFF TO THE NORTHEAST GRADUALLY AS HEIGHTS BUILD ALOFT...EVEN THOUGH CORFIDI VECTORS TRACK THE INDIVIDUAL SHOWERS OFF TO THE SOUTHEAST. THINK THERE IS POTENTIAL FOR THIS SHOWER ACTIVITY TO GRAZE THE U.P.-WISCONSIN BORDER THROUGH 00Z. HOWEVER...LOW LEVELS ARE VERY DRY...SO WILL LEAVE IT AS A CHANCE OF SPRINKLES. RECENT RADAR TRENDS ALREADY SHOW THE BACK EDGE OF THE PRECIP LIFTING NE OVER THE ARROWHEAD...SO AM COUNTING ON THIS TREND KEEPING THE BORDER DRY AFTER 00Z. MID AND UPPER CLOUDS WILL BE LIFTING OFF TO THE NE AS WELL SO SHOULD SEE DECREASING CLOUDS THROUGH THE NIGHT OVER THE NORTH. THE PRESSURE GRADIENT WILL BE TIGHTENING TONIGHT...WHICH WILL KEEP LOWS WARMER THAN LAST NIGHT. WILL GO WITH MID TO UPPER 40S FOR LOWS. WEDNESDAY...UPSTREAM COLD FRONT WILL MOVE INTO THE NORTHERN MISSISSIPPI VALLEY DURING THE AFTERNOON. WITH THE AREA FIRMLY IN THE WARM SECTOR...WILL HAVE MID AND UPPER CLOUDS NORTH AND WEST OF THE REGION...BUT SHOULD SEE MOSTLY CLEAR TO PARTLY CLOUDY SKIES FOR THE DAY. THE PRESSURE GRADIENT WILL TIGHTEN AHEAD OF THE FRONT...AND SOUTH WINDS WILL TURN GUSTY WITH DAYTIME HEATING AND MIXING. SOME GUSTS COULD REACH 30 OR MAYBE EVEN 35 MPH. HIGHS TOMORROW IN THE MID 70S TO LOW 80S. .LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY. ONE OF THE FORECAST CHALLENGES FOR THIS PERIOD IS TRYING TO LASSO IN THE LOCATIONS OF THE FRONT FOR THE MEMORIAL DAY WEEKEND. ANOTHER ISSUE IS TIMING AND STRENGTH OF A SHORT WAVE TROUGH FOR LATER THURSDAY AND ESPECIALLY THURSDAY NIGHT. LITTLE CHANGE FROM THE GOING FORECAST FROM 24 HOURS AGO FROM WEDNESDAY NIGHT INTO THURSDAY AS A SURFACE HIGH PRESSURE WITH UPPER RIDGE DRIFTING OVER THE AREA WILL CONTINUE TO PROVIDE QUIET WEATHER TO THE AREA. MODELS CONTINUE TO CONFINE CONVECTION OVER THE NORTHERN PLAINS WITH THE BROAD UPPER TROUGH. PWATS GRADUALLY INCREASE TO 1.75 ALONG THE FRONT OVER THE NORTHERN PLAINS. UNTIL THIS UPPER RIDGE IS NUDGED FAR ENOUGH EAST...WILL CONTINUE TO CONFINE ANY SMALL PCPN MENTION AND CLOUDS WEST OF A RHI TO AUW LINE. WILL THEN FOCUS ON HIGHER POPS FOR THE THURSDAY AFTERNOON INTO THURSDAY NIGHT PERIOD AS A SHORT WAVE SLIDES OVER THE STATE. A SURFACE LOW AND UPPER JET COUPLET PROGGED TO AFFECT THE NORTH HALF OF THE STATE DURING THIS PERIOD PROVIDES SOME POTENTIAL OF STRONG TO SEVERE STORMS. PROGS ARE A BIT MORE PROGRESSIVE WITH THE FRONTAL PASSAGE LATE THURSDAY NIGHT. USING THE H8 FRONT...THE FRONT IS DRIVEN SOUTH OF THE AREA FRIDAY INTO FRIDAY NIGHT FOR A DIMINISHED PERIOD OF CONVECTION. PROGS IN GOOD AGREEMENT WITH H8 WARM FRONT LIFTING BACK NORTH AGAIN ON SATURDAY SO INCREASED CONVECTION INCLUDING THUNDER FROM SOUTH TO NORTH DURING THE DAY. PROGS CONTINUE TO LIFT THE FRONT NORTH TO GRADUALLY DIMINISH CONVECTION OVER CENTRAL AND EAST CENTRAL WISCONSIN BUT WILL CONFINE BEST PCPN CHANCES ACROSS THE NORTH SUNDAY AND PERHAPS INTO MONDAY CLOSER TO THE WARM FRONT. AREAS TO THE SOUTH LIKELY TO BE CAPPED IN A VERY WARM HUMID AIR MASS AS UPPER HEIGHTS BUILD. ANOTHER FRONT IS PROGGED TO SLIDE OVER MONDAY INTO MONDAY NIGHT FOR ANOTHER SHOT OF CONVECTION. PWATS INCREASE TO 1.70 INCHES ALONG THE FRONT...HOWEVER AT THIS TIME IT APPEARS THE FRONTS ARE A LITTLE TOO PROGRESSIVE FOR HEAVY RAINS TO CONCENTRATE IN ANY ONE LOCATION WITH THE EXCEPTION OF THE FAR NORTH NEAR THE WARM FRONT. && .AVIATION...HIGH PRESSURE WILL MOVE TO THE EASTERN GREAT LAKES WHILE A COLD FRONT SHIFTS INTO THE NORTHERN MISSISSIPPI VALLEY BY LATE IN THE TAF PERIOD. MID AND HIGH CLOUDS WILL PASS OVER NORTHERN WISCONSIN THIS AFTERNOON...BUT AM NOT EXPECTING ANY PRECIP. VFR CONDITIONS THROUGH THE REST OF THE TAF PERIOD...BUT WILL HAVE WIND SHEAR DEVELOP OVER N-C WISCONSIN TONIGHT...AND SOUTH WINDS WILL TURN GUSTY BY LATE MORNING TOMORROW. MPC && .MARINE...A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED LATE WEDNESDAY AFTERNOON INTO THURSDAY NIGHT. INCREASING SOUTH WINDS ARE EXPECTED ON WEDNESDAY...THEN STRONG SOUTH WINDS ARE EXPECTED ON THURSDAY. A FEW GUSTS COULD APPROACH GALE FORCE NEAR THE SHORELINE THURSDAY AFTERNOON. WINDS AND WAVES WILL GRADUALLY SUBSIDE THURSDAY NIGHT. FOR THE UPCOMING MEMORIAL DAY WEEKEND...IT WILL BE UNSETTLED AS THERE WILL BE CHANCES FOR THUNDERSTORMS EACH DAY. A WARM FRONT IS EXPECTED TO SLOWLY PUSH NORTHWARD INTO THE AREA OVER THE WEEKEND. THERE IS A LOT OF UNCERTAINTY ON HOW FAR NORTH THE WARM FRONT WILL MAKE IT INTO NORTHEAST WISCONSIN AND WHERE THE BEST CHANCES FOR THUNDERSTORMS WOULD OCCUR. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MPC/TDH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1147 PM CDT MON MAY 21 2012 .SHORT TERM...TONIGHT THROUGH THURSDAY 325 PM CDT MON MAY 21 2012 MAIN FORECAST CONCERNS ARE FROST POTENTIAL TONIGHT AND PRECIPITATION CHANCES AS WELL AS TEMPERATURES WEDNESDAY INTO THURSDAY. CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED RIDGING FROM THE DESERT SOUTHWEST INTO ALBERTA AND WEAK TROUGHING OVER THE WESTERN GREAT LAKES REGION. HIGH PRESSURE DOMINATES AT THE SURFACE ON THE BACK SIDE OF THE WEAK TROUGHING... ENCOMPASSING THE ENTIRE FORECAST AREA. DRY AIR...SEEN ON THE 12Z MPX...GRB AND DVN SOUNDINGS HAS RESULTED IN A SUNNY DAY ACROSS THE FORECAST AREA. MIXING UP THROUGH 850MB WHERE TEMPS ARE AROUND 6C HAS YIELDED TEMPERATURES MAINLY IN THE 70S...AND DEWPOINTS MOSTLY DOWN INTO THE LOW TO MID 30S. TO THE WEST...AN AREA OF MID LEVEL CLOUDS HAVE BEEN EXPANDING ACROSS NORTH DAKOTA AND INTO WESTERN MINNESOTA. THESE CLOUDS ARE IN RESPONSE TO WARM ADVECTION AND MOISTURE RETURN ON THE BACK SIDE OF THE SURFACE HIGH AND AHEAD OF THE UPPER RIDGE AXIS. THERE WAS A LITTLE LIGHT SHOWER ACTIVITY ON THE WESTERN SIDE OF THE CLOUDS...ASSOCIATED WITH 305 K ISENTROPIC LIFT...BUT THIS HAS SINCE DISSIPATED. 12Z SOUNDINGS SHOWED MUCH WARMER AIR OVER THE DAKOTAS...WITH 850MB TEMPS OF 10-15C ON AVERAGE WITH RAPID CITY AT 19C. TONIGHT AND TUESDAY...UPPER RIDGING OVER THE NORTHERN ROCKIES WILL SHIFT EAST INTO THE FORECAST AREA ON TUESDAY...PUSHED ALONG BY TROUGHING CURRENTLY OFF THE PACIFIC NORTHWEST MOVING INLAND. IN RESPONSE...A SURFACE LOW DEEPENS ACROSS THE DAKOTAS...INCREASING THE WARM ADVECTION DOWNSTREAM INTO THE FORECAST AREA. WITH THIS WARM ADVECTION WE SHOULD SEE SOME OF THOSE MID CLOUDS OVER WESTERN MINNESOTA MOVE ACROSS. TRENDS IN MODEL RH FIELDS SUGGEST SOME DISSIPATION OF THE MID CLOUDS AS THEY PUSH EAST...ESPECIALLY DURING THE DAY TUESDAY. THIS MATCHES THE PREVIOUS FORECAST. IN ADDITION... IT APPEARS MOST OF THE MID CLOUDS WILL STAY WEST OF THE MISSISSIPPI RIVER TONIGHT. THIS IS CRITICAL BECAUSE THE SURFACE RIDGE SHOULD BE CENTERED OVER WISCONSIN MUCH OF TONIGHT...LEADING TO FAVORABLE RADIATIONAL COOLING CONDITIONS. SINCE BLACK RIVER FALLS AND SPARTA DROPPED INTO THE LOW TO MID 30S LAST NIGHT...SEE NO REASON WHY THAT WILL NOT HAPPEN AGAIN. THIS MEANS THAT OUR TYPICAL WISCONSIN COLD SPOTS COULD SEE SOME FROST. NOT ENOUGH OF AN EXPANSIVE AREA OF COLD TEMPS IS FORECAST TO WARRANT A FROST ADVISORY...THOUGH. WEST OF THE MISSISSIPPI RIVER...INCREASING WINDS SHOULD ALLOW TEMPERATURES TO STAY WARMER THERE. WITH INCREASING SUNSHINE AND SOUTHERLY WINDS ON TUESDAY...AS WELL AS 850MB TEMPS CLIMBING TO AROUND 10C BY 18Z...SHOULD ALLOW FOR HIGHS WELL INTO THE 70S. WARMEST TEMPS LIKELY WEST. TUESDAY NIGHT AND WEDNESDAY...THE UPPER TROUGHING OVER THE NORTHWEST U.S. IS PROGGED TO DEEPEN DURING THIS PERIOD. A FAIRLY POTENT SHORTWAVE EJECTING OUT OF THIS TROUGH THROUGH THE DAKOTAS WILL CAUSE THE LOW PRESSURE AREA THERE TO LIFT INTO NORTHWEST ONTARIO BY 00Z THURSDAY. ITS ASSOCIATED COLD FRONT APPEARS TO BE TRENDING SLOWER...NOW ONLY REACHING WESTERN MINNESOTA BY 00Z THURSDAY. THE ECMWF HAS BEEN SUGGESTING THIS FOR QUITE AWHILE. ONLY MODEL THAT HAS THE FRONT APPROACHING THE FORECAST AREA IS THE 21.12Z NAM...AND EVEN IT HAS TRENDED SLOWER FROM ITS PREVIOUS RUNS. THEREFORE...HAVE CONSIDERED THE NAM A FAST OUTLIER. ANY CONVECTION IS LIKELY TO BE HIGHLY TIED TO THE FRONT...GIVEN CAPPING PRESENT IN THE WARM SECTOR AHEAD OF IT. THEREFORE...HAVE DRIED OUT MUCH OF THE FORECAST EXCEPT FOR A SMALL AREA IN SOUTHEAST MINNESOTA WHICH IS CLOSEST TO THE FRONTAL BOUNDARY. THESE SMALL CHANCES MAY BE ABLE TO BE PULLED IN LATER FORECASTS. A BREEZY SOUTH WIND WILL HELP KEEP TEMPERATURES UP TUESDAY NIGHT INTO THE 50S IN MOST LOCATIONS. SOME OF SOUTHEAST MN MAY NOT DROP BELOW 60...MEANWHILE THE COLD SPOTS OF WISCONSIN COULD DECOUPLE AND DROP INTO THE UPPER 40S. MUCH WARMER 850MB TEMPS ARE PROGGED FOR WEDNESDAY...ON THE ORDER OF 16-18C. NORMALLY THIS COULD PRODUCE HIGHS OF 85 TO 90. HOWEVER...THERE IS INCREASING CIRRUS THROUGH THE DAY TO TEMPER HIGHS SOMEWHAT. WEDNESDAY NIGHT AND THURSDAY...ANOTHER SURFACE LOW IS PROGGED TO FORM OVER SOUTHEAST COLORADO LATE WEDNESDAY. A POTENT SHORTWAVE EJECTING OUT OF THE DEEPENING WESTERN TROUGH WILL LIFT THIS LOW NORTHEAST...RIDING UP THE COLD FRONT AND CROSSING CENTRAL MINNESOTA ON THURSDAY. THE 21.12Z GFS/UKMET BOTH DEPICT SOME QPF WEDNESDAY NIGHT OVER WISCONSIN...BUT THESE SEEM ODD GIVEN OUR FORECAST AREA IS UNDERNEATH THE MAIN MOISTURE TRANSPORT STREAM WITHOUT MOISTURE CONVERGENCE...AS WELL AS CAPPING ALOFT TO ELEVATED CONVECTION. THEREFORE...FOR WEDNESDAY NIGHT...KEPT ALL PRECIPITATION CHANCES OVER FAR NORTHWEST SECTIONS OF THE FORECAST AREA. THESE CHANCES ARE STILL LOW...20-30...BECAUSE THE FRONTOGENETICAL ZONE ASSOCIATED WITH THE COLD FRONT LOOKS TO STAY ACTIVE ALONG AND NORTHWEST OF IT...WHICH KEEPS THE BULK OF THE PRECIPITATION MORE FROM SOUTHWEST MINNESOTA INTO THE DULUTH AREA. BETTER SHOT EXISTS FOR THE COLD FRONT TO COME IN ON THURSDAY...IN THIS CASE ASSOCIATED WITH THE NEW LOW COMING UP. THE 21.12Z GFS REMAINS THE FASTEST MODEL TO DO SO...WITH THE ECMWF AND ESPECIALLY GEM SUGGESTING SLOWER. LEANED TOWARDS THE SLOWER PASSAGE...WHICH KEEPS ALL PRECIPITATION CHANCES OVER THE NORTHWEST HALF OF THE FORECAST AREA. TEMPERATURES BOTH WEDNESDAY NIGHT AND ESPECIALLY THURSDAY HAVE BEEN WARMED UP...DUE TO THE SLOWER FRONTAL PASSAGE AND MAINTAINING A LONGER PERIOD OF BREEZY SOUTH WINDS. THURSDAY COULD TOUCH 90...ESPECIALLY IN THE SOUTHEAST WHERE MORE SUN IS PRESENT TO COMBINE WITH 850MB TEMPS UP POSSIBLY NEAR 20C. .LONG TERM...THURSDAY NIGHT THROUGH MONDAY 325 PM CDT MON MAY 21 2012 MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES AND WHEN THE HEAT UP WILL COME. MODELS ARE BECOMING IN MUCH BETTER AGREEMENT ON THE LONG TERM FORECAST...SO CONFIDENCE IS INCREASING ON WHAT WILL HAPPEN. IN GENERAL...TROUGHING LOOKS TO REMAIN IN THE WESTERN U.S.... INTENSIFYING BY SATURDAY MORNING. WITH THE DEEPENING TROUGH OUT WEST...THE RESPONSE IS TO BUILD SOME PRETTY STRONG RIDGING TO THE EAST. THEREFORE...AFTER WHAT LOOKS TO BE A COLD FRONTAL PASSAGE THURSDAY NIGHT...THAT COLD FRONT WILL NOT BE ABLE TO DROP TOO FAR SOUTH. MAINTAINED SOME CHANCES OF SHOWERS AND THUNDERSTORMS FOR THURSDAY NIGHT...AND THESE MAY NEED TO BE INCREASED OVER WESTERN SECTIONS WITH A SHORTWAVE PROGGED TO COME OUT. IN FACT...IF THE 21.12Z ECMWF/GEM ARE CORRECT...SOME OF THE STORMS THURSDAY NIGHT COULD BE SEVERE. WESTERN SECTIONS OF THE AREA LOOK TO GET A BREAK FROM PRECIPITATION ON FRIDAY WITH THE FRONT PASSED...BUT STILL MAINTAINED A CHANCE ELSEWHERE SINCE THE FRONT IS STILL MOVING THROUGH. DEFINITELY COOLER ON FRIDAY BEHIND THE FRONT...BUT STILL SEASONABLE. FRONT SHOULD LAY UP IN SOUTHERN IOWA FRIDAY NIGHT AND THEN BEGIN TO RETREAT NORTH AS A WARM FRONT AS THE UPPER RIDGE STRENGTHENS. MOISTURE TRANSPORT NORTH OF THE FRONT COULD YIELD CONVECTION FRIDAY NIGHT THROUGH SATURDAY. CANNOT RULE OUT SOME OF THIS BEING SEVERE TOO. 850MB TEMPS CLIMB TO 20C OR HIGHER SOUTH OF THE FRONT...WHICH MEANS ON SATURDAY THERE IS POTENTIAL FOR A 20 DEGREE OR MORE SPREAD ACROSS THE FORECAST AREA. MODELS AGREE THAT THE WESTERN TROUGH BEGINS EJECTING OUT SATURDAY NIGHT...ALLOWING THE RIDGE AND WARM SECTOR TO BUILD OVER THE FORECAST AREA. THIS MEANS THE CONVECTION SHOULD SLOWLY SHIFT NORTH...ALLOWING FOR HEAT AND LIKELY SOME HUMIDITY TO MOVE IN. RAISED HIGHS ON SUNDAY TO THE MID 80S TO NEAR 90...BUT FURTHER INCREASES COULD BE NEEDED. SAME GOES FOR LOWS SATURDAY NIGHT AND SUNDAY NIGHT WHERE POTENTIAL EXISTS FOR TEMPERATURES TO NOT DIP BELOW 70. LAST ISSUE IS A COLD FRONT PROGGED TO COME AT THE AREA FOR SUNDAY NIGHT AND MONDAY...ASSOCIATED WITH THE EJECTING WESTERN TROUGH. THE GFS IS THE FASTEST ON THIS FRONT...WHEREAS THE 21.12Z ECMWF HAS SLOWED DOWN FROM ITS PREVIOUS RUN. FOR NOW HAVE FOLLOWED A CONSENSUS AND INCLUDED 20-40 PERCENT CHANCES FOR SUNDAY NIGHT AND MONDAY. HOWEVER...WOULD NOT BE SURPRISED IF THE SLOWER FRONTAL TIMING PANS OUT...RESULTING IN A WARMER AND DRIER FORECAST. IN SUMMARY...SOME POTENTIAL FOR SEVERE STORMS THURSDAY NIGHT AND FRIDAY NIGHT/SATURDAY...THEN HEATING UP FOR THE END OF MEMORIAL DAY WEEKEND. && .AVIATION...THROUGH 06Z WEDNESDAY 1145 PM CDT MON MAY 21 2012 HIGH PRESSURE WILL MOVE EAST INTO EASTERN WISCONSIN OVERNIGHT. AS THIS OCCURS...THE WINDS WILL SHIFT TO THE SOUTH AND THEN INCREASE ON TUESDAY MORNING AS THE PRESSURE GRADIENT TIGHTENS ON THE BACK SIDE OF THE HIGH PRESSURE. AS DIURNAL MIXING OCCURS...THE WIND GUSTS ACROSS SOUTHEAST MINNESOTA WILL CLIMB INTO THE 20 TO 30 KNOT RANGE...AND 15 TO 25 KNOTS ACROSS WESTERN WISCONSIN. WITH THE LOSS OF DIURNAL HEATING DURING THE EARLY EVENING...THE WIND GUSTS WILL QUICKLY SUBSIDE AT BOTH LOCATIONS. OTHER THAN OCCASIONALLY BOUTS OF SCATTERED 10-20K CLOUDS...SKIES WILL BE MOSTLY CLEAR. && .ARX WATCHES/WARNINGS/ADVISORIES... 325 PM CDT MON MAY 21 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1055 PM MDT WED MAY 23 2012 .UPDATE... ISSUED AT 1035 PM MDT WED MAY 23 2012 WINDS HAVE SUBSIDED TO BELOW ADVISORY CRITERIA OVER THE LAST 30 MINUTES SO CANCELLED THE ADVISORY. THE RED FLAG WARNING HAS ALSO BEEN CANCELLED AS MOST OBS SHOWING RH/S ABOVE 15 PERCENT WITH MOST AREAS SHOWING WINDS BELOW 25 MPH THOUGH OCCNL GUSTS ABOVE THAT THRESHOLD CONTINUE. THE COLD FRONT HAS JUST ABOUT REACHED NEW MEXICO THIS EVENING WITH SOME RESIDUAL MOISTURE STILL CAUSING SOME SHOWERS ALONG THE I-70 CORRIDOR AND EVEN SNOWFALL AROUND VAIL PASS. THESE SHOULD END IN THE NEXT FEW HOURS. CURRENT FORECAST CAPTURES ALL THIS QUITE WELL SO NO CHANGES EXPECTED AT THIS TIME. UPDATE ISSUED AT 926 PM MDT WED MAY 23 2012 THE COLD FRONT IS SWEEPING SOUTH ACROSS SE UTAH/SW COLORADO. AT 03Z THIS EVENING...THE COLD FRONT IS PASSING THE DURANGO AIRPORT. WHILE WINDS ARE EXPECTED TO SUBSIDE IN THE POST FRONTAL AIR MASS...WINDS STILL FAIRLY STRONG AND ELECTED TO EXTEND THE RED FLAG WARNING AND WIND ADVISORY THROUGH 11 PM. THE VAIL PASS WEB CAM SHOWED LIGHT SNOW ACCUMULATION ON THE GRASSY AND DIRT SURFACES. HIGH MOUNTAIN REMOTE SENSORS INDICATE THAT TEMPERATURES ARE AROUND 32F AND INDICATE THAT SNOW ACCUMULATIONS WILL BE FAIRLY COMMON ABOVE 10K FEET. THE BRUNT OF THE PRECIPITATION OCCURS BEFORE MIDNIGHT WITH THE HRRR SHOWING FAST DROP OFF IN QPF AMOUNTS AFTER 06Z. ELECTED TO ISSUE SPECIAL WEATHER STATEMENT TO ADDRESS THE IMPACT OF LATE SEASON SNOWFALL INSTEAD OF HOIST A WINTER WEATHER ADVISORY. WIDESPREAD SNOW ABOVE 10K FEET IS EXPECTED TO TAPER OFF WITHIN THE NEXT 2-3 HOURS (AND PAVEMENTS MAY STAY WET WITH SLUSHY AREAS). UPDATE ISSUED AT 723 PM MDT WED MAY 23 2012 AS THE NOSE OF JET PUNCHES INTO WRN COLORADO...PRECIPITATION HAS INCREASED ACROSS PARTS OF NORTHWEST AND WEST CENTRAL COLORADO. RAISED POPS TO ACCOUNT FOR THIS INCREASE...ALTHOUGH TRACE AMOUNTS MAY BE THE ONLY RAINFALL THE LOWER VALLEYS RECEIVE AS THE EVENING SOUNDING SHOWS A MOSTLY DRY SUB CLOUD LAYER. HOWEVER PRECIPITABLE WATER DID RISE TO ONE HALF INCH. THESE SHOWERS HAVE ENHANCED GUSTY WINDS IN THE CENTRAL VALLEY WITH LOCAL GUSTS TO 40 MPH. FARTHER SOUTH...GUSTY WINDS HAVE BEEN STRONGER WITH GUSTS OF 45 TO 50 MPH FAIRLY COMMON. NO UPDATES TO THE WIND ADVISORY THAT EXPIRES AT 9 PM MDT THIS EVENING. && .SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT) ISSUED AT 345 PM MDT WED MAY 23 2012 LARGE SCALE ASCENT IS INCREASING OVER NORTHERN UTAH INTO NORTHWEST COLORADO AHEAD OF THE MID LEVEL TROF AXIS DROPPING THROUGH THE GREAT BASIN. DARKENING IN THE WATER VAPOR IMAGERY SHOWING THIS LIFT BEING ENHANCED BY ARRIVING JET MAX AND ASSOCIATED PV LOBE WITH INCREASING INSTABILITY FROM DAYTIME HEATING AND COOLER AIR MOVING IN WITH THE TROF ALSO AIDING ASCENT. 88D MOSAIC IS RESPONDING BY SHOWING AN INCREASE IN COVERAGE MAINLY NORTH OF A MOAB TO MONTROSE TO GUNNISON LINE WHICH IS NEAR WHERE THE SURFACE FRONT HAS SETTLED AND MAY BE WAVERING. THIS LIFT SEEMS TO BE HELPING TO MIX OUT THE ATMOSPHERE NORTH OF FRONT AS WELL WITH WINDS PICKING UP AT GJT THE PAST HOUR OR SO. SOME GUIDANCE INDICATING VERY GUSTY WINDS THROUGH EARLY EVENING ACROSS THE GRAND VALLEY AND WILL CONTINUE TO MONITOR. FARTHER SOUTH IN ADVISORY REGION STRONG MIXING AHEAD OF THE FRONT HAS BEEN PUSHING WIND GUSTS NEAR 45 MPH AND EXPECT THE NEXT FEW HOURS THEY COULD CONTINUE TO STRENGTHEN SO WILL LEAVE ADVISORY AS IS. AS FOR PRECIPITATION THE BEST FOCUS CONTINUES TO POINT AT THE NORTHERN AND CENTRAL MOUNTAINS THROUGH THIS EVENING WHERE MID LEVEL LAPSE RATES WILL CONTINUE TO STEEPEN UNDER THE STRONGER DYNAMICS ALOFT. MOISTURE IS ALREADY IN PLACE NORTH OF THE FRONT SO SHOULD NOT TAKE MUCH TO GET PRECIPITATION TO THE SURFACE. ONE CAVEAT HOWEVER IS DRIER AIR IS ADVECTING IN A LOW LEVELS FROM WYOMING SO WILL KEEP THE HIGHEST POPS ON THE TERRAIN WHERE OROGRAPHICS WILL ALSO CONTINUE INTO THE THURSDAY MORNING AS THE UPPER SUPPORT LIFTS OUT OF OUR REGION. WOULD NOT BE SURPRISED TO SEE SOME LIGHT SNOW ABOVE THE 9000 FT LEVEL BUT SHOULD NOT ANTICIPATING A LARGE IMPACT ATTM WITH AN INCH OR LESS LIMITED TO THE VEGETATION. THE SURFACE FRONT WILL BE SAGGING THROUGH THE SOUTHERN CWA TONIGHT AS WELL AND THIS MAY HELP TRIGGER SOME ISOLATED CONVECTION IN THE SOUTHERN MOUNTAINS...BUT CONFIDENCE NOT HIGH SO POPS REFLECT THIS. TEMPERATURES WILL BE QUITE COOL COMPARED TO THE PAST FEW NIGHTS WITH SOME VALLEYS IN THE NORTH DROPPING TO NEAR THE FREEZING MARK. WITH THE FRONT NEAR THE SOUTHERN BORDER ON THURSDAY AND COOLER DAY LOOKS ON TRACK AND THERE SHOULD BE A FAIR AMOUNT OF SUNSHINE IN PLACE BEFORE AFTERNOON HEATING STARTS POPPING THE CUMULUS. THE EXCEPTION WILL BE OVER THE FAR NORTHERN MOUNTAINS EARLY DUE TO THE MOIST DENDRITIC FLOW AND COLD POOL ALOFT WHICH SHOULD PRODUCE SOME LIGHT PRECIPITATION. HIGHS ACTUALLY LOOK TO BE RUN NEAR OR BELOW NORMAL OUTSIDE THE 4 CORNERS REGION AND DID USE A BLEND OF GUIDANCE. A STRONGER WESTERN SYSTEM WILL BE PUSHING INTO THE EASTERN GREAT BASIN TOMORROW NIGHT. THIS WILL QUICKLY BACK AND INCREASE THE FLOW TO THE SOUTHWEST AND PUSH THE WARM FRONT STRUCTURE BACK NORTHWARD THROUGH THE CWA. ATTM THE MODELS ARE PUTTING OUT SOME LIGHT PRECIPITATION BUT MODEL SOUNDINGS WOULD INDICATE THIS IS MOSTLY IN THE FORM OF ACCAS MOVING OVERHEAD IN THE STRONG WAA PATTERN. FOR NOW JUST PUT IN SOME ISOLATED MENTION OVER THE HIGHEST TERRAIN IN THE NORTHEAST CWA. BETTER MIXING AND THE WAA SHOULD PUSH LOWS UP A FEW DEGREES OVER TONIGHT/S READINGS. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 345 PM MDT WED MAY 23 2012 MODELS REMAIN CONSISTENT ON DROPPING THE NEXT PACIFIC TROUGH INTO THE WESTERN GREAT BASIN FRIDAY AND THEN LIFTING IT OUT TO THE NORTHEAST THIS WEEKEND...DRAGGING A COLD FRONT ACROSS SAT OR SAT EVENING. NOT A LOT OF MOISTURE INDICATED WITH THIS FRONT...SO JUST SLIGHT CHANCE TO CHANCE POPS FOR MAINLY NE UT AND NW CO SHOULD SUFFICE FOR NOW. ABOVE NORMAL TEMPS FOR FRIDAY AS WARM ADVECTION RETURNS. WITH THE MAIN UPPER LOW LIFTING OUT WELL TO OUR NW...MAY SEE THE EASTWARD PROGRESSION OF THE COLD FRONT SLOW ON SATURDAY SO WILL KEEP MAX TEMPS ON THE WARM SIDE SAT OVER ALL BUT NE UT. THE BIGGEST IMPACT WILL LIKELY BE THE SOUTH TO SOUTHWEST WIND... WHICH IS EXPECTED TO STRENGTHEN SIGNIFICANTLY FRIDAY THROUGH SATURDAY. BOTH NAM AND GFS SHOW 40-45 KTS AT 700 MB...WITH SOME AREAS OF 50-55 KTS WINDS INDICATED FRI NIGHT. WIND ADVISORIES MAY BE NEEDED...AND A FIRE WEATHER WATCH HAS ALREADY BEEN ISSUED FOR FRI AND SAT. COOLER TEMPERATURES FOLLOW FOR SUNDAY BEHIND THE FRONT WITH A CHANCE OF SHOWERS PERSISTING FOR THE NORTHERN MTNS IN THE WEST TO NW FLOW. DRY WESTERLY FLOW EXPECTED MONDAY THROUGH WEDNESDAY WITH TEMPERATURES WARMING UP AGAIN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 345 PM MDT WED MAY 23 2012 SHOWERS SHOULD BE ENDING IN THE NEXT FEW HOURS ALONG WITH THE LOW TO MID CEILINGS THAT ARE OVER MUCH OF THE CWA. IFR CONDITIONS AT KASE THIS HOUR DUE TO SNOW SHOULD ALSO BECOME VFR OVER THE NEXT FEW HOURS AS SHOWERS END. FOR TOMORROW...VFR WILL BE FELT ACROSS ENTIRE CWA AS ZONAL FLOW SETS UP. && .FIRE WEATHER... ISSUED AT 345 PM MDT WED MAY 23 2012 RED FLAG WARNING CONTINUES FOR SOUTHWEST AND PORTIONS OF WEST-CENTRAL CO THROUGH THIS EVENING. THURSDAY LOOKS LIKE A BIT OF DOWN DAY WITH SLIGHTLY WEAKER WINDS ALOFT AND AT THE SURFACE...THOUGH LOCALIZED BORDERLINE CRITICAL CONDITIONS WILL BE POSSIBLE IN SOUTHWEST CO. WINDY AND DRY CONDITIONS LOOK IN STORE FOR FRIDAY AND SATURDAY AS THE NEXT STORM DROPS INTO THE GREAT BASIN. THE FIRE WEATHER WATCH CURRENTLY STARTING FRIDAY AFTERNOON HAS NOW BEEN EXTENDED UNTIL SATURDAY EVENING. AM CONCERNED THAT WINDS WILL PERSIST FRIDAY NIGHT AT LEAST ACROSS THE MID-SLOPES AND THERMAL BELTS WHERE HUMIDITY RECOVERY MAY BE THE POOREST. DO NOT DOUBT THAT THERE WILL BE A PERIOD OF NON-CRITICAL CONDITIONS LATER FRIDAY NIGHT ESPECIALLY FOR VALLEYS...BUT WITH ANY VALLEY INVERSIONS BEING SHALLOW AND EASILY MIXED OUT...CRITICAL FIRE WEATHER CONDITIONS COULD RETURN AS EARLY AS MID-MORNING SATURDAY. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...FIRE WEATHER WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY EVENING FOR COZ200>203-207-290-292-293. UT...NONE. && $$ UPDATE...TGR SHORT TERM...15 LONG TERM...JAD AVIATION...TGR FIRE WEATHER...JAD
AREA FORECAST DISCUSSION
NWS MIAMI FL
217 AM EDT THU MAY 24 2012 .AVIATION... ISOLATED TO SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TODAY...MAINLY OVER THE EAST COAST TERMINALS...AS MOST OF THE DEEP LAYER MOISTURE REMAINS EAST OF THE PENINSULA ACROSS THE BAHAMAS. WILL INCLUDE VCSH/VCTS IN THIS PACKAGE THROUGH THE AFTERNOON PERIOD AND UPDATE AS NEEDED. PERIODS WITH MVFR CIGS/VSBYS WILL BECOME POSSIBLE IN AND AROUND ANY MODERATE TO HEAVY SHOWER/TSTM THAT DEVELOP THROUGH THIS PERIOD. WITH THE TROUGH AXIS OVER THE AREA...MAINLY LIGHT WINDS WILL BE EXPECTED WITH AFTERNOON SEA BREEZES ANTICIPATED ALONG THE GULF AND ATLANTIC COASTS. 85/AG && .PREV DISCUSSION... /ISSUED 951 PM EDT WED MAY 23 2012/ UPDATE...CHALLENGING FORECAST. LOCAL AREA HAS COME UNDER SUBSIDENCE TODAY AS EVIDENCED BY LITTLE CONVECTION. WE WERE IN THE SUBSIDENCE SIDE OF A DEPARTING JET. 500 MB TEMP HAS WARMED QUITE A BIT...NOW AT -6.9C ON THE EVENING MIAMI SOUNDING. SO NOT AS UNSTABLE. CONVECTION HAS REMAINED GENERALLY OFF THE SE FL COAST ALL DAY, THOUGH A FEW SHOWERS AND STORMS DID DEVELOP OVER THE INTERIOR AND GULF COAST. CONVECTION OVER THE ATLANTIC HAS NOW EVEN DIMINISHED. HOWEVER, THERE IS A SHORTWAVE OVER THE NORTH CENTRAL GULF HEADING ESE...AND MODELS INDICATE MORE FAVORABLE JET DYNAMICS LATE TONIGHT AND ESPECIALLY THURSDAY. HOWEVER, GFS/ECMWF CONSENSUS IS TO KEEP THE BEST CONVERGENCE/HEAVY RAIN JUST OFF TO OUR SOUTHEAST...AS A SURFACE/LOW LEVEL TROUGH AXIS LIES ALONG THE SE FL COAST. BUT SE FLOW IS STRENGTHENING SOME AND THIS COULD INCREASE COASTAL CONVERGENCE ALONG THE ATLANTIC COAST OVERNIGHT. THE LATEST HRRR SHOWS SHOWERS DEVELOPING AND MOVING NW ONSHORE THE ATLANTIC COAST LATER TONIGHT, ALTHOUGH IT`S OVERDOING ACTIVITY CURRENTLY. SO HERE`S THE BOTTOM LINE - THE MOST FAVORED AREA OVERNIGHT THROUGH THURSDAY FOR HEAVY RAIN LOOKS TO BE OFF OUR ATLANTIC COAST. HOWEVER, GIVEN HIGH MOISTURE AND POSSIBLE COASTAL CONVERGENCE, WILL MAINTAIN POPS AS IS. STILL LIKE THE FLOOD WATCH FOR MIAMI- DADE COUNTY THROUGH 8 PM THU...GIVEN THE EXTREME RAINFALL WHICH OCCURRED FROM THE SWEETWATER-DORAL AREAS ON TUESDAY WITH STANDING WATER REMAINING IN AREAS. IT WON`T TAKE MUCH RAIN TO CAUSE FLASH FLOODING ACROSS THESE HARD HIT LOCALES. /GREGORIA PREV DISCUSSION... /ISSUED 741 PM EDT WED MAY 23 2012/ AVIATION... SOUTH FLORIDA IS AT THE EDGE OF DEEP TROPICAL MOISTURE TO THE EAST AND ISOLATED CONVECTIVE ACTIVITY TO THE WEST. THE EAST COAST TERMINALS INCLUDE VCSH AFTER MIDNIGHT SINCE MOST GUIDANCE INSISTS IN INCREASING THE SHOWER ACTIVITY OVER NIGHT NEAR THE EAST COAST. HOWEVER, THIS IS A LOW CONFIDENCE FORECAST. FOR THURSDAY WE EXPECT SHOWERS AND THUNDERSTORMS TO BECOME MORE WIDESPREAD IN THE AFTERNOON AND EVENING. ALL TAF LOCATIONS INCLUDE THE CHANCE FOR VCTS FOR THURSDAY AFTERNOON. WINDS ARE EXPECTED TO BE FROM THE EAST SOUTHEAST BELOW 10 KNOTS. PREV DISCUSSION... /ISSUED 659 PM EDT WED MAY 23 2012/ UPDATE...CONVECTION TODAY HAS BEEN VERY MINIMAL DUE TO BROAD SCALE SUBSIDENCE. HOWEVER, AS A SHORTWAVE OVER THE NORTH CENTRAL GULF AS SEEN ON WATER VAPOR IMAGERY IS MOVING RATHER FAST TO THE EAST. THIS COULD INDUCE SOME OF THE HIGHER MOISTURE OVER THE ATLANTIC, AND ASSOCIATED RAINFALL, TO MOVE TOWARDS THE NW AND ONSHORE THE SE FLORIDA COAST OVERNIGHT. UNCERTAIN FORECAST TONIGHT AND THURSDAY AS WE ARE ON THE EDGE OF DEEP CARIBBEAN MOISTURE AND TROUGH AXIS. WILL MAINTAIN THE CHANCE POPS TONIGHT. FLOOD WATCH REMAINS IN EFFECT FOR MIAMI-DADE COUNTY THROUGH 8 PM THURSDAY FOR THE POTENTIAL FOR ADDITIONAL RAINS LEADING TO FLASH FLOODING. /GREGORIA PREV DISCUSSION... /ISSUED 348 PM EDT WED MAY 23 2012/ FLOOD WATCH EXTENDED UNTIL THURSDAY EVENING FOR MIAMI-DADE COUNTY... POSSIBLE STRONG TO EVEN SEVERE STORMS FOCUSED INTERIOR THIS AFTERNOON... DISCUSSION... EARLY THIS AFTERNOON...A MID TO UPPER LEVEL LOW WAS LOCATED OVER THE CAROLINAS WITH A TROUGH OF LOW PRESSURE EXTENDING SOUTHWEST THROUGH THE CWA AND INTO THE NORTHWEST CARIBBEAN SEA WHERE A WEAK SURFACE LOW PRESSURE SYSTEM WAS LOCATED. THE NATIONAL HURRICANE CENTER AT THIS TIME IS GIVING THE SURFACE LOW IN THE NORTHWEST CARIBBEAN SEAS A NEAR 0 PERCENT CHANCE OF DEVELOPMENT DURING THE NEXT 48 HOURS. THE MID TO UPPER LEVEL LOW WILL MOVE NORTHEAST KEEPING THE TROUGH OF LOW PRESSURE IN PLACE OVER THE CWA TONIGHT INTO THURSDAY...AS THE WEAK SURFACE LOW MOVES NORTHEAST AND THROUGH SOUTH FLORIDA OR JUST TO THE EAST OF SOUTH FLORIDA. THIS WILL KEEP THE STEERING FLOW IN PLACE ALONG WITH THE DEEP TROPICAL MOISTURE WORKING INTO THE SOUTHERN PORTION OF THE CWA FROM THE NORTHWEST CARIBBEAN SEA. THE LATEST PWAT`S FROM THE FORECAST MODELS ARE STILL SHOWING 2 TO 2.4 INCHES OVER THE SOUTHERN AREAS OF THE CWA LATE TONIGHT INTO THURSDAY WHICH IS CLOSE TO THE ALL TIME MAXIMUM PWAT FOR THIS TIME OF YEAR. THIS WILL ALLOW FOR SCATTERED SHOWERS AND THUNDERSTORMS TO CONTINUE OVER THE EAST COAST METRO AREAS TAPERING DOWN TO ISOLATED OVER THE INTERIOR AND WEST COAST METRO AREAS. ON THURSDAY...THE ACTIVITY COULD INCREASE TO SCATTERED COVERAGE OVER THE INTERIOR AREAS TO NUMEROUS COVERAGE OVER THE EAST COAST METRO AREAS. THEREFORE...A FLOOD WATCH FOR MIAMI-DADE COUNTY HAS BEEN EXTENDED THROUGH THURSDAY EVENING...DUE TO THE GROUND BEING VERY SATURATED FROM THE PREVIOUS RAINS OVER THE PAST COUPLE OF DAYS AND THE POTENTIAL OF MORE LOCALLY HEAVY RAINFALL TONIGHT INTO THURSDAY. THE WEAK LOW WILL THEN MOVE INTO WESTERN ATLANTIC WATERS PUSHING THE TROUGH OF LOW PRESSURE SOUTHWARD INTO THE FLORIDA KEYS. THIS WILL ALLOW FOR DRIER AIR TO WORK INTO THE CWA FROM THE NORTH FOR FRIDAY INTO THIS WEEKEND WHICH IN TURN WILL REDUCE THE COVERAGE OF THE SHOWERS AND THUNDERSTORMS OVER THE CWA. THE BEST CHANCE OF SHOWER AND THUNDERSTORM ACTIVITY WILL BE OVER THE INTERIOR AND WEST COAST METRO AREAS THIS WEEKEND...DUE TO THE NORTHEAST STEERING FLOW BEHIND THE TROUGH OF LOW PRESSURE. EXTENDED FORECAST... THE LATEST LONG RANGE MODELS ARE NOW SPLITTING ON THE RETURN MOISTURE TO THE AREA FOR EARLY TO MIDDLE OF NEXT WEEK. THE 23/00Z RUN OF THE ECMWF LONG RANGE MODEL TRIES TO BRING THE LOW BACK TO THE FLORIDA PENINSULA ALONG WITH THE DEEP MOISTURE...WHILE THE 23/12Z GFS MODEL PUSHES THE LOW EASTWARD TAKING THE DEEP TROPICAL MOISTURE WITH IT. SO AT THIS TIME WILL CONTINUE TO SHOW SCATTERED SHOWERS AND THUNDERSTORMS OVER THE CWA FOR EARLY TO MIDDLE OF NEXT WEEK...UNTIL THE MODELS BECOME MORE IN LINE WITH EACH OTHER FOR EARLY TO MIDDLE OF NEXT WEEK. MARINE... THE WINDS OVER THE CWA WATERS WILL REMAIN AT 15 KNOTS OR LESS TONIGHT INTO THIS WEEKEND WHILE SWINGING FROM A SOUTHERLY DIRECTION TONIGHT TO A NORTHERLY DIRECTION THIS WEEKEND. THE ONLY EXCEPTION TO THIS IS IN THE ATLANTIC WATERS WHERE THE WINDS WILL BE 15 TO 20 KNOTS TONIGHT. THE SEAS WILL ALSO REMAIN BELOW 6 FEET FOR BOTH THE ATLANTIC AND GULF WATERS OF SOUTH FLORIDA TONIGHT THROUGH THIS WEEKEND. SO WILL CONTINUE THE SCEC FOR THE ATLANTIC WATERS DUE TO THE WIND SPEEDS. FIRE WEATHER... THE RELATIVE HUMIDITIES WILL REMAIN ABOVE THE 35 PERCENT CRITICAL VALUE THROUGH THE WEEKEND. SO NO PROBLEMS WITH THE FIRE WEATHER PRODUCT. HYDROLOGY... FOR DETAILS ON THE RAINFALL AMOUNTS ACROSS SOUTH FLORIDA PLEASE SEE THE FLOOD WATCH AND THE HYDROLOGIC OUTLOOK STATEMENTS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 86 75 89 77 / 50 30 20 20 FORT LAUDERDALE 86 77 88 78 / 70 40 20 20 MIAMI 87 76 89 77 / 70 40 20 20 NAPLES 89 74 90 74 / 40 20 30 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...FLOOD WATCH THROUGH THIS EVENING FOR COASTAL MIAMI DADE-FAR SOUTH MIAMI DADE-INLAND MIAMI DADE-METRO MIAMI DADE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...15/JR AVIATION/RADAR...85/AG
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
241 AM EDT THU MAY 24 2012 .SYNOPSIS... A WEAK SURFACE TROUGH WILL REMAIN OVER THE REGION TODAY. UPPER LEVEL HIGH PRESSURE WILL BEGIN TO BUILD INTO OUR REGION FRIDAY THROUGH SUNDAY...WHILE LOW PRESSURE DEVELOPS AND REMAINS OFFSHORE. THE UPPER HIGH WILL WEAKEN BY EARLY NEXT WEEK. THIS...ALONG WITH THE POSSIBILITY OF INCREASING ATMOSPHERIC MOISTURE...AND THE APPROACH OF A COLD FRONT...MAY RESULT IN INCREASED PRECIPITATION CHANCES EARLY TO MID NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... IT APPEARS A WEAK SURFACE TROUGH/DEWPOINT GRADIENT CONTINUES TO STRETCH GENERALLY ACROSS THE SE PART OF THE FORECAST AREA (FA). UPPER LOW JUST TO OUR NORTH...WITH A PAIR OF VORTS THAT THE MODELS GENERALLY KEEP TO OUR NORTH TODAY. DRY MID LEVEL AIR OVER THE FA APPARENT ON SATELLITE WATER VAPOR IMAGERY. MODEL GUIDANCE GENERALLY SUGGESTS A DRY ATMOSPHERE OVER MOST OF OUR FA...WITH SOME MID LEVEL CAPPING NOTED. MODELS INDICATE A WEAK SE LOW LEVEL SYNOPTIC FLOW THAT COULD BRING THE WEAK TROUGH NORTH A LITTLE...AS WELL AS AIDING A SEA BREEZE BOUNDARY MAKING IT INTO OUR FA. LOCAL MODEL AND OTHER GUIDANCE SUGGESTS A FEW SHOWERS...AND A POSSIBLE THUNDERSTORM...THAT COULD DEVELOP ALONG THE SURFACE TROUGH OR SEA BREEZE THIS AFTERNOON. WILL MAINTAIN SLIGHT CHANCE POPS FOR SHOWERS AND ISO TS...MAINLY SE TIER. && .SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/... BY TONIGHT AND FRIDAY...MODELS INDICATE UPPER LEVEL TROUGH TO SHIFT TO OUR EAST...WITH AN UPPER LOW CUTTING OFF...AND A SURFACE LOW DEVELOPING...OFFSHORE THE CAROLINAS. UPPER HIGH TO DEVELOP OVER THE LOWER MISSISSIPPI VALLEY. THIS WILL RESULT IN SOME UPPER HEIGHT RISES FOR OUR FA...GENERALLY KEEPING OUR FA DRY AND CAPPED. UPPER HIGH CENTER TO SHIFT NE SLIGHTLY SATURDAY AND SUNDAY...REMAINING TO OUR NW NEAR KY/TN...WHILE THE OFFSHORE UPPER AND SURFACE LOWS SLOWLY DRIFT TO THE SOUTHWEST IN A CLOCKWISE DIRECTION AROUND THE HIGH. MODELS APPEAR TO KEEP THE LOWS AND ASSOCIATED MOISTURE/IMPACTS WELL TO OUR SE...AND GENERALLY RESTRICT CONVECTION TO THE MOUNTAINS AND COAST SAT/SUN. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... GFS/ECMWF GENERALLY AGREE ON WEAKENING THE UPPER HIGH...AND DEVELOPING WEAK TROUGHINESS OVER THE EASTERN CONUS...MONDAY THROUGH WEDNESDAY. THEY ALSO SUGGEST A FRONTAL BOUNDARY TO APPROACH THE REGION LATE TUESDAY INTO WEDNESDAY. AN ITEM OF UNCERTAINTY INVOLVES WHAT HAPPENS TO THE UPPER/SURFACE LOWS OFFSHORE THE SE US COAST...AND WHETHER ANY TROPICAL DEVELOPMENT/TRANSITION IS POSSIBLE. ECMWF KEEPS THE LOW JUST OFFSHORE NE/EAST CENTRAL FLORIDA...BEFORE KICKING OUT TO THE ENE AS THE UPPER HIGH WEAKENS AND UPPER TROUGHINESS DEVELOPS AND APPROACHES FROM THE WEST. GFS SPLITS THE UPPER ENERGY INTO TWO SEGMENTS...ONE THAT MOVES WEST AND BRINGS THE SURFACE LOW WEST INTO NORTH FLORIDA/NE GOMEX AREA MON/TUE. THE GFS SOLUTION RESULTS IN SOME MOISTURE INCREASE FOR OUR FA LATE SUN INTO MON...WHILE THE ECMWF SOLUTION WOULD CONTINUE TO KEEP OUR POPS MINIMAL FOR THAT TIME PERIOD. GENERALLY ACCEPTED A BLEND OF ONGOING FORECAST AND LATEST GUIDANCE...PROVIDING SLIGHT CHANCE POPS SUN AFTN THROUGH MON NT...WITH CHANCE POPS TUE AFTN THROUGH WED WITH THE FRONT. && .AVIATION /07Z THURSDAY THROUGH MONDAY/... VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD EXCEPT POSSIBLE MVFR VSBYS AT AGS/OGB THROUGH 13Z. RAP AND NAM BUFKIT INDICATING LOW LEVEL MOISTURE COMBINED WITH A LOW LEVEL JET...WHICH COULD PRODUCE MVFR CIGS THROUGH 13Z. CONFIDENCE IS LOW SINCE OTHER GUIDANCE NOT SHOWING THIS. SCATTERED CUMULUS CLOUDS EXPECTED WITH DAYTIME HEATING TODAY. CANNOT RULE OUT ISOLATED CONVECTION NEAR OGB GIVEN MODERATE INSTABILITY AND SEA BREEZE FRONT. HOWEVER...COVERAGE IS TOO LIMITED TO INCLUDE IN TAF. WINDS WILL INCREASE FROM THE SOUTH SOUTHEAST 5 TO 10 MPH. EXTENDED AVIATION OUTLOOK...MVFR OR LOWER CONDITIONS POSSIBLE IN FOG/STRATUS LATE TONIGHT INTO EARLY FRIDAY MORNING. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
140 AM EDT THU MAY 24 2012 .SYNOPSIS... UPPER LEVEL TROUGH OVER THE REGION WILL SLOWLY MOVE EASTWARD AND EXIT THE REGION THURSDAY NIGHT. WEAK HIGH PRESSURE AND AN UPPER LEVEL RIDGE WILL BUILD IN FOR FRIDAY THROUGH THE WEEKEND. && .NEAR TERM /TONIGHT/... UPPER LEVEL TROUGH REMAINS OVER THE REGION. LATEST SATELLITE IMAGERY SHOWS THE CENTER OF THE UPPER CIRCULATION REMAINS IN NORTH CAROLINA. STILL AN ISOLATED SHOWER/STORM POSSIBLE ACROSS THE NORTHEASTERN PORTION OF THE CWA WHERE SEA-BREEZE AND OTHER OUTFLOW BOUNDARIES HAVE KEPT A FEW SHOWERS GOING. ACTIVITY SHOULD DIMINISH BY MIDNIGHT. ENTIRE AREA SHOULD BE DRY BY MIDNIGHT. LOW TEMPERATURES IN THE MIDDLE 60S STILL LOOK OK. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... UPPER TROUGH FINALLY BEGINS TO MOVE EAST AND SHOULD EXIT THE AREA THURSDAY NIGHT. WILL KEEP A 20 PERCENT CHANCE OF DIURNAL CONVECTIVE ACTIVITY FOR THURSDAY AFTERNOON AND EVENING. AN UPPER RIDGE WILL BUILD EAST OVER THE FORECAST AREA FRIDAY AND FRIDAY NIGHT. DRY WEATHER IS EXPECTED FRIDAY AND FRIDAY NIGHT. HIGH TEMPERATURES BOTH THURSDAY AND FRIDAY WILL BE IN THE UPPER 80S TO AROUND 90. OVERNIGHT LOWS WILL BE IN THE MIDDLE TO UPPER 60S. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... MEDIUM RANGE MODELS IN GOOD AGREEMENT INITIALLY FOR THE WEEKEND SATURDAY AND SUNDAY WITH UPPER RIDGE CONTROLLING THE WEATHER. DRY AND QUITE WARM CONDITIONS SATURDAY AND SUNDAY. HIGHS NEAR 90 TO THE LOWER 90S BOTH DAYS. LOWS SATURDAY NIGHT IN THE MIDDLE TO UPPER 60S. SOME MODEL DIFFERENCES BY MONDAY AS TO WHEN UPPER RIDGE SHOULD WEAKEN ALLOWING MORE MOISTURE INTO THE REGION. BOTH GFS AND ECMWF SHOW A WEAK LOW PRESSURE OR TROUGH NEAR THE SOUTHEAST COAST SPREADING SOME MOISTURE TO THE AREA. ECMWF HAS SURFACE LOW CLOSER TO SOUTHEAST COAST ON MONDAY AND THEREFORE PULLS MOISTURE IN SOONER THAN THE GFS. WILL INTRODUCE A SLIGHT CHANCE OF CONVECTIVE ACTIVITY BY MONDAY AFTERNOON. THEN LIKE AT LEAST A SLIGHT CHANCE TUESDAY AND WEDNESDAY WITH CONTINUED SOUTH TO SOUTHEAST LOW LEVEL WIND FLOW ADVECTING MOISTURE TO THE REGION. SUMMER-LIKE TEMPERATURES EXPECTED IN THE EXTENDED PERIOD WITH HIGHS IN THE UPPER 80S TO LOWER 90S. OVERNIGHT LOWS MAINLY IN THE UPPER 60S. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD EXCEPT POSSIBLE MVFR VSBYS AT AGS/OGB THROUGH 13Z. RAP AND NAM BUFKIT INDICATING LOW LEVEL MOISTURE COMBINED WITH A LOW LEVEL JET...WHICH COULD PRODUCE MVFR CIGS THROUGH 13Z. CONFIDENCE IS LOW SINCE OTHER GUIDANCE NOT SHOWING THIS. SCATTERED CUMULUS CLOUDS EXPECTED WITH DAYTIME HEATING TODAY. CANNOT RULE OUT ISOLATED CONVECTION NEAR OGB GIVEN MODERATE INSTABILITY AND SEA BREEZE FRONT. HOWEVER...COVERAGE IS TOO LIMITED TO INCLUDE IN TAF. WINDS WILL INCREASE FROM THE SOUTH SOUTHEAST 5 TO 10 MPH. EXTENDED AVIATION OUTLOOK...MVFR OR LOWER CONDITIONS POSSIBLE IN FOG/STRATUS LATE TONIGHT INTO EARLY FRIDAY MORNING. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
410 AM CDT THU MAY 24 2012 ...UPDATED AND RESENT THE SHORT TERM DISCUSSION... .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 408 AM CDT THU MAY 24 2012 THE SHORTER TERM MODELS OF THE NAM AND THE HRRR NOW SHOW THERE WILL NOT BE ANY PRECIP IN OUR FORECAST AREA TODAY. THE COLD FRONT IS THROUGH OUR CWA, WITH A LOW PRESSURE SYSTEM POSITIONED OVER SOUTHEAST COLORADO. AN UPPER LEVEL DISTURBANCE IS MOVING EAST-NORTHEAST BUT TRAVELING THROUGH AREAS NORTH OF OUR COUNTY WARNING AREA, NORTHERN KANSAS AND NEBRASKA AND POINTS NORTHEASTWARD. THERE IS SOME CIRRUS AROUND AND THINK THE GRIDS WILL PRODUCE MOSTLY SUNNY CONDITIONS. WHEN THE FRONT FIRST WENT THROUGH, THE WINDS BEHIND THE FRONT QUICKLY PICKED UP INTO ADVISORY LEVELS, AND THUS A SHORT TERM WIND ADVISORY WAS ISSUED FOR THAT AREA WEST OF A DIGHTON TO MONTEZUMA LINE, AND ALSO NORTH OF A JOHNSON CITY TO MONTEZUMA LINE. AT THE TIME OF WRITING THIS SHORT TERM DISCUSSION, WINDS HAD FALLEN BACK TO LESS THAN ADVISORY CRITERIA AT ALL SITES EXCEPT HUGOTON AND SCOTT CITY. THIS WIND ADVISORY WILL EXPIRE AT 09Z, AND SHOULD NOT SHOW UP IN THE NEXT ZONE ISSUANCE. TEMPERATURES TODAY WILL BE COOLER THAN YESTERDAY`S NEAR CENTURY MARKS, DUE TO THE COLD FRONTAL PASSAGE AND HIGH CLOUDS. HIGHS TODAY SHOULD RANGE FROM THE MID 80S ALONG THE OKLAHOMA PANHANDLE TO THE UPPER 70S NORTH OF THE I-70 CORRIDOR. THE COLD FRONT MENTIONED ABOVE WILL COME BACK NORTH TONIGHT AS A WARM FRONT. JUST HOW FAST NORTH IT WILL MOVES IS HANDLED DIFFERENTLY BY THE MODELS. THE NAM MODEL BRINGS THE FRONT NORTH THE FASTEST, WITH THE GFS AND ECMWF MODELS SLOWER. BY THE TIME THE FRONT REACHES OUR NORTHERN COUNTIES OF ELLIS, TREGO, RUSH, NESS, LANE AND SCOTT BY 09Z, THERE COULD BE A FEW THUNDERSTORMS FORM IN THE ELEVATED UNSTABLE LAYERS OF THE ATMOSPHERE. I ONLY PLACED 20 POPS IN, AS THE TIMING OF THE FRONT IS STILL IN QUESTION. CLOUDS WILL BLANKET MOST OF SOUTHWESTERN KANSAS THURSDAY NIGHT, AND WINDS NEAR THE OKLAHOMA BORDER WILL BE SOUTH AT 10 TO 20 MPH BEHIND THE FRONT AND EASTERLY AT 10 TO 20 MPH NORTH OF THE FRONT. TEMPERATURES THURSDAY NIGHT WILL BE SOMEWHAT ELEVATED, ONLY FALLING TO THE MID 60S IN THE MEDICINE LODGE AND PRATT AREAS, INTO THE LOWER 60S FROM LIBERAL TO DODGE CITY TO LARNED, AND INTO THE MIDDLE 50S FROM SYRACUSE TO SCOTT CITY TO WAKEENEY. .LONG TERM...(FRIDAY THROUGH THURSDAY) ISSUED AT 359 AM CDT THU MAY 24 2012 A CHALLENGING FORECAST LIES AHEAD FOR THE COMING SEVERAL DAYS, AS A FEW OPPORTUNITIES FOR CONVECTION APPEAR POSSIBLE. BY FRIDAY MORNING, A WARM FRONT WILL BE LIFTING NORTHWARD THROUGH SOUTHWEST KANSAS. THE MODELS DIFFER SIGNIFICANTLY WITH THIS FRONT. THE GFS PRODUCES QPF AS EARLY AS OVERNIGHT THURSDAY HEADING INTO FRIDAY MORNING, AND REALLY INCREASING THE QPF AROUND THE 12Z TIMEFRAME. BY CONTRAST THE NAM AND ECMWF ARE MORE IN LINE WITH A DRY SOLUTION. THE CONVECTION PRODUCED IN THESE CASES ARE MORE IN LINE WITH THE EDGE OF A CAPPING LATER IN THE MID LEVELS THAT IS LOCATED ACROSS NORTHERN KANSAS. IN EITHER CASE; STRONG LOW LEVEL THETA-E ADVECTION AND ISENTROPIC LIFT IN THE MORNING, OR BREAKING THE CAP LATE IN THE DAY FARTHER NORTH, QUARTER TO GOLFBALL SIZED HAIL WOULD BE LIKELY. HOWEVER, THE MOST LIKELY EVENT IS PROBABLY ALONG THE LINES OF THE ECMWF AND NAM GIVEN THE WARM TEMPERATURES IN THE MID LEVELS OF 13 TO 14 DEGREES C. IF THE WARM AIR ALOFT IS STRONG ENOUGH OF A CAP ON FRIDAY, THE POTENTIAL FOR SEVERE CONVECTION MIGHT BE RELEGATED EVEN FARTHER NORTH INTO NORTH CENTRAL KANSAS AND NEBRASKA. SURFACE TEMPERATURES WILL EXCEED 95 DEGREES IN THIS WARM BOUNDARY LAYER AIR AND LIKELY HIT 100 DEGREES OR MORE IN THE RED HILLS REGION. IT IS UNKNOWN AT THIS TIME IF THE SMOKE FROM THE NEW MEXICO FIRES WILL PLAY A ROLE IN INHIBITING INSOLATION WHICH IN TURN COULD PREVENT TEMPERATURES FROM REACHING THE AFOREMENTIONED VALUES. BUT IT IS SOMETHING TO CONSIDER IN THE NEXT 24 OR SO HOURS. HEADING INTO THE WEEKEND, A CONSENSUS OF THE MODELS WOULD SEEM TO SUPPORT AT LEAST SOME POTENTIAL FOR DRYLINE TRIGGERED CONVECTION ACROSS CENTRAL KANSAS ON SATURDAY. HOWEVER, IT IS NOT CLEAR AT ALL JUST WHERE THE DRYLINE MIGHT BE LOCATED AT THIS TIME. GENERALLY ISOLATED DISCREET CONVECTION WITHIN AMPLE SHEAR FOR AT LEAST THE POTENTIAL FOR SUPERCELLS PRODUCING UP TO GOLFBALL SIZED HAIL. A MORE ORGANIZED SEVERE CONVECTIVE POTENTIAL COULD OCCUR ON SUNDAY. THE FORCING MECHANISMS FOR THIS POTENTIAL WILL BE AN ADVANCING UPPER TROUGH WITH A LARGE COLD POOL (COOLING TEMPERATURES ALOFT) AND A LEAD UPPER JET`S RIGHT REAR QUADRANT. THE GFS AND ECMWF BOTH APPEAR TO SUPPORT A TORNADIC SUPERCELL ENVIRONMENT SUNDAY AFTERNOON ALONG THE WARM FRONT-SURFACE LOW INTERSECTION. BEYOND THIS PERIOD, THE FORECAST APPEARS TO CREATE MORE UNCERTAINTY. THE OVERALL CONSENSUS APPEARS TO BE A FLATTENING OF THE UPPER FLOW AS THE UPPER JET LIFTS INTO THE UPPER MIDWEST THROUGH TUESDAY. THIS SHOULD, WITH TIME ALLOW DRIER AIR TO SETTLE OVER WESTERN KANSAS REDUCING THE ODDS OF THUNDERSTORMS. BEFORE THE ECMWF AND GFS BOTH TREND RAPIDLY TOWARD STRONG MOISTURE RETURN AND CONVECTION ONCE AGAIN BY AROUND DAY 7. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 359 AM CDT THU MAY 24 2012 AS A FRONT MOVES ACROSS CENTRAL KANSAS, SOUTH WINDS WILL SHIFT TO THE NORTH OR NORTHEAST AND GUST BRIEFLY INTO THE 25 TO 30 KNOT RANGE. AFTER 09Z, EXPECT NORTHWEST WINDS IN THE 15 TO 20 KNOT RANGE. AS HIGH PRESSURE SETTLES SOUTH INTO THE TAF AREAS THURSDAY MORNING, WINDS WILL BECOME NORTHWEST AND WILL SUBSIDE TO AROUND 12 TO 13 KNOTS. THE ONLY CLOUDS EXPECTED ARE HIGH CIRRUS CLOUDS IN THE 150-200 THOUSAND FOOT RANGE, SO VFR CONDITIONS WILL PREVAIL THROUGH THE 24 HOUR TAF PERIOD. && .PRELIMINARY POINT TEMPS/POPS... DDC 83 62 97 70 / 0 10 10 10 GCK 82 60 96 68 / 0 10 10 10 EHA 85 59 96 66 / 0 10 10 10 LBL 85 62 100 68 / 0 10 10 10 HYS 80 59 86 69 / 10 10 20 20 P28 85 67 97 72 / 0 10 20 20 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BURKE LONG TERM...RUSSELL AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
359 AM CDT THU MAY 24 2012 ...UPDATED FOR THE SHORT TERM AND LONG TERM DISCUSSION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 359 AM CDT THU MAY 24 2012 THE SHORTER TERM MODELS OF THE NAM AND THE HRRR NOW SHOW THERE WILL NOT BE ANY PRECIP IN OUR FORECAST AREA TODAY. THE COLD FRONT IS THROUGH OUR CWA, WITH A LOW PRESSURE SYSTEM POSITIONED OVER SOUTHEAST COLORADO. AN UPPER LEVEL DISTURBANCE IS MOVING EAST-NORTHEAST BUT TRAVELING THROUGH AREAS NORTH OF OUR COUNTY WARNING AREA, NORTHERN KANSAS AND NEBRASKA AND POINTS NORTHEASTWARD. THERE IS SOME CIRRUS AROUND AND THINK THE GRIDS WILL PRODUCE MOSTLY SUNNY CONDITIONS. WHEN THE FRONT FIRST WENT THROUGH, THE WINDS BEHIND THE FRONT QUICKLY PICKED UP INTO ADVISORY LEVELS, AND THUS A SHORT TERM WIND ADVISORY WAS ISSUED FOR THAT AREA WEST OF A DIGHTON TO MONTEZUMA LINE, AND ALSO NORTH OF A JOHNSON CITY TO MONTEZUMA LINE. AT THE TIME OF WRITING THIS SHORT TERM DISCUSSION, WINDS HAD FALLEN BACK TO LESS THAN ADVISORY CRITERIA AT ALL SITES EXCEPT HUGOTON AND SCOTT CITY. THIS WIND ADVISORY WILL EXPIRE AT 09Z, AND SHOULD NOT SHOW UP IN THE NEXT ZONE ISSUANCE. TEMPERATURES TODAY WILL BE COOLER THAN YESTERDAY`S NEAR CENTURY MARKS, DUE TO THE COLD FRONTAL PASSAGE AND HIGH CLOUDS. HIGHS TODAY SHOULD RANGE FROM THE MID 80S ALONG THE OKLAHOMA PANHANDLE TO THE UPPER 70S NORTH OF THE I-70 CORRIDOR. THE COLD FRONT MENTIONED ABOVE WILL COME BACK NORTH TONIGHT AS A WARM FRONT. JUST HOW FAST NORTH IT WILL MOVES IS HANDLED DIFFERENTLY BY THE MODELS. THE NAM MODEL BRINGS THE FRONT NORTH THE FASTEST, WITH THE GFS AND ECMWF MODELS SLOWER. BY THE TIME THE FRONT REACHES OUR NORTHERN COUNTIES OF ELLIS, TREGO, RUSH, NESS, LANE AND SCOTT BY 09Z, THERE COULD BE A FEW THUNDERSTORMS FORM IN THE ELEVATED UNSTABLE LAYERS OF THE ATMOSPHERE. I ONLY PLACED 20 POPS IN, AS THE TIMING OF THE FRONT IS STILL IN QUESTION. CLOUDS WILL BLANKET MOST OF SOUTHWESTERN KANSAS THURSDAY NIGHT, AND WINDS NEAR THE OKLAHOMA BORDER WILL BE SOUTH AT 10 TO 20 MPH BEHIND THE FRONT AND EASTERLY AT 10 TO 20 MPH NORTH OF THE FRONT. TEMPERATURES THURSDAY NIGHT WILL BE SOMEWHAT ELEVATED, ONLY FALLING TO THE MID 60S IN THE MEDICINE LODGE AND PRATT AREAS, INTO THE LOWER 60S FROM LIBERAL TO DODGE CITY TO LARNED, AND INTO THE MIDDLE 50S FROM SYRACUSE TO SCOTT CITY TO WAKEENEY. .LONG TERM...(FRIDAY THROUGH THURSDAY) ISSUED AT 359 AM CDT THU MAY 24 2012 A CHALLENGING FORECAST LIES AHEAD FOR THE COMING SEVERAL DAYS, AS A FEW OPPORTUNITIES FOR CONVECTION APPEAR POSSIBLE. BY FRIDAY MORNING, A WARM FRONT WILL BE LIFTING NORTHWARD THROUGH SOUTHWEST KANSAS. THE MODELS DIFFER SIGNIFICANTLY WITH THIS FRONT. THE GFS PRODUCES QPF AS EARLY AS OVERNIGHT THURSDAY HEADING INTO FRIDAY MORNING, AND REALLY INCREASING THE QPF AROUND THE 12Z TIMEFRAME. BY CONTRAST THE NAM AND ECMWF ARE MORE IN LINE WITH A DRY SOLUTION. THE CONVECTION PRODUCED IN THESE CASES ARE MORE IN LINE WITH THE EDGE OF A CAPPING LATER IN THE MID LEVELS THAT IS LOCATED ACROSS NORTHERN KANSAS. IN EITHER CASE; STRONG LOW LEVEL THETA-E ADVECTION AND ISENTROPIC LIFT IN THE MORNING, OR BREAKING THE CAP LATE IN THE DAY FARTHER NORTH, QUARTER TO GOLFBALL SIZED HAIL WOULD BE LIKELY. HOWEVER, THE MOST LIKELY EVENT IS PROBABLY ALONG THE LINES OF THE ECMWF AND NAM GIVEN THE WARM TEMPERATURES IN THE MID LEVELS OF 13 TO 14 DEGREES C. IF THE WARM AIR ALOFT IS STRONG ENOUGH OF A CAP ON FRIDAY, THE POTENTIAL FOR SEVERE CONVECTION MIGHT BE RELEGATED EVEN FARTHER NORTH INTO NORTH CENTRAL KANSAS AND NEBRASKA. SURFACE TEMPERATURES WILL EXCEED 95 DEGREES IN THIS WARM BOUNDARY LAYER AIR AND LIKELY HIT 100 DEGREES OR MORE IN THE RED HILLS REGION. IT IS UNKNOWN AT THIS TIME IF THE SMOKE FROM THE NEW MEXICO FIRES WILL PLAY A ROLE IN INHIBITING INSOLATION WHICH IN TURN COULD PREVENT TEMPERATURES FROM REACHING THE AFOREMENTIONED VALUES. BUT IT IS SOMETHING TO CONSIDER IN THE NEXT 24 OR SO HOURS. HEADING INTO THE WEEKEND, A CONSENSUS OF THE MODELS WOULD SEEM TO SUPPORT AT LEAST SOME POTENTIAL FOR DRYLINE TRIGGERED CONVECTION ACROSS CENTRAL KANSAS ON SATURDAY. HOWEVER, IT IS NOT CLEAR AT ALL JUST WHERE THE DRYLINE MIGHT BE LOCATED AT THIS TIME. GENERALLY ISOLATED DISCREET CONVECTION WITHIN AMPLE SHEAR FOR AT LEAST THE POTENTIAL FOR SUPERCELLS PRODUCING UP TO GOLFBALL SIZED HAIL. A MORE ORGANIZED SEVERE CONVECTIVE POTENTIAL COULD OCCUR ON SUNDAY. THE FORCING MECHANISMS FOR THIS POTENTIAL WILL BE AN ADVANCING UPPER TROUGH WITH A LARGE COLD POOL (COOLING TEMPERATURES ALOFT) AND A LEAD UPPER JET`S RIGHT REAR QUADRANT. THE GFS AND ECMWF BOTH APPEAR TO SUPPORT A TORNADIC SUPERCELL ENVIRONMENT SUNDAY AFTERNOON ALONG THE WARM FRONT-SURFACE LOW INTERSECTION. BEYOND THIS PERIOD, THE FORECAST APPEARS TO CREATE MORE UNCERTAINTY. THE OVERALL CONSENSUS APPEARS TO BE A FLATTENING OF THE UPPER FLOW AS THE UPPER JET LIFTS INTO THE UPPER MIDWEST THROUGH TUESDAY. THIS SHOULD, WITH TIME ALLOW DRIER AIR TO SETTLE OVER WESTERN KANSAS REDUCING THE ODDS OF THUNDERSTORMS. BEFORE THE ECMWF AND GFS BOTH TREND RAPIDLY TOWARD STRONG MOISTURE RETURN AND CONVECTION ONCE AGAIN BY AROUND DAY 7. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 359 AM CDT THU MAY 24 2012 AS A FRONT MOVES ACROSS CENTRAL KANSAS, SOUTH WINDS WILL SHIFT TO THE NORTH OR NORTHEAST AND GUST BRIEFLY INTO THE 25 TO 30 KNOT RANGE. AFTER 09Z, EXPECT NORTHWEST WINDS IN THE 15 TO 20 KNOT RANGE. AS HIGH PRESSURE SETTLES SOUTH INTO THE TAF AREAS THURSDAY MORNING, WINDS WILL BECOME NORTHWEST AND WILL SUBSIDE TO AROUND 12 TO 13 KNOTS. THE ONLY CLOUDS EXPECTED ARE HIGH CIRRUS CLOUDS IN THE 150-200 THOUSAND FOOT RANGE, SO VFR CONDITIONS WILL PREVAIL THROUGH THE 24 HOUR TAF PERIOD. && .PRELIMINARY POINT TEMPS/POPS... DDC 62 97 70 97 / 10 10 10 20 GCK 60 96 68 95 / 10 10 10 20 EHA 59 96 66 95 / 10 10 10 20 LBL 62 100 68 96 / 10 10 10 20 HYS 59 86 69 97 / 10 20 20 10 P28 67 97 72 97 / 10 20 20 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE && $$ SHORT TERM...BURKE LONG TERM...RUSSELL AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1237 AM MDT THU MAY 24 2012 .UPDATE... ISSUED AT 1236 AM MDT THU MAY 24 2012 UPDATED GRIDS AND ZONES FOR THE CANCELLATION OF SEVERE THUNDERSTORM WATCH 294. OTHERWISE NO OTHER CHANGES. && .SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT) ISSUED AT 1245 PM MDT WED MAY 23 2012 EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW BROAD TROUGH ACROSS THE NORTHERN ROCKIES...WITH WEST/SOUTHWEST FLOW ACROSS THE INTER-MOUNTAIN WEST INTO THE CENTRAL HIGH PLAINS. AT THE SURFACE A COLD FRONT HAS STALLED OVER WESTERN KANSAS...CURRENTLY ACROSS THE EASTERN PART OF THE CWA. A SHORTWAVE TROUGH CURRENTLY OVER THE GREAT BASIN WILL MOVE EAST-NORTHEAST ACROSS NORTH CENTRAL COLORADO AND SOUTHWEST NEBRASKA TONIGHT. SHOWERS/THUNDERSTORMS HAVE ALREADY DEVELOPED AHEAD OF THIS FEATURE ALONG THE FRONT RANGE INTO SOUTHEASTERN WYOMING. THIS ACTIVITY WILL SPREAD SOUTH AND EAST OVER OUR CWA LATER THIS AFTERNOON...WITH COVERAGE INCREASING ACROSS THE NORTHERN PART OF OUR FORECAST AREA THROUGH 06Z. CONVERGENCE ZONE ALONG AND NORTH OF STALLED FRONT COULD ACT AS A FOCUS FOR EARLIER THUNDERSTORM INITIATION LATER THIS AFTERNOON AND EVENING...HOWEVER THIS IS REMOVED FROM LARGE SCALE ASCENT ASSOCIATED WITH SHORTWAVE SO COVERAGE SHOULD BE LIMITED ACROSS THE SOUTH. VERY STRONG SHEAR IS PRESENT ACROSS THE CWA...WITH INSTABILITY DECREASING THE FURTHER NORTH IN THE CWA WHERE TD VALUES IN THE 30-40F RANGE HAVE ADVECTED IN BEHIND THE FRONT. SEVERE CONVECTION SHOULD BE LIMITED TO THE I-70 CORRIDOR THROUGH EARLY EVENING WHERE THE BEST OVERLAP BETWEEN SHEAR/INSTABILITY IS EXPECTED. LATER TONIGHT ELEVATED INSTABILITY COULD COMBINE WITH STRONG UPPER LEVEL DYNAMICS ASSOCIATED WITH THE SHORTWAVE ACROSS SOUTHWEST NEBRASKA TO BRING ADDITIONAL SEVERE CHANCES. SUBSIDENCE QUICKLY BUILDS IN BEHIND DEPARTING SHORTWAVE TROUGH AFTER 06Z...WITH COVERAGE DECREASING FROM THE SOUTHWEST TO THE NORTHEAST THROUGH SUNRISE THURSDAY. .LONG TERM...(THURSDAY THROUGH WEDNESDAY) ISSUED AT 224 PM MDT WED MAY 23 2012 THURSDAY-THURSDAY NIGHT...PV ANOMALY WILL LIFT TO THE NORTH AND EAST OF THE AREA FAIRLY QUICKLY DURING THE MORNING HOURS...WITH MID LEVEL FRONTOGENESIS QUICKLY DIMINISHING AND DEEP LAYER DIV Q FIELDS INDICATE FAIRLY STRONG LARGE SCALE FORCING FOR SUBSIDENCE OVER THE AREA. STILL HAVE A FEW TIMING CONCERNS THOUGH...AND THINK HOLDING ONTO SOME SMALL POPS WARRANTED FOR AT LEAST THE FIRST FEW HOURS OF THE PERIOD. SOUNDINGS SUGGEST THAT WEAK INSTABILITY WILL LINGER ACROSS MUCH OF THE AREA THROUGH THE DAY...AS DIFFERENTIAL TEMP ADVECTION SHOULD LEAD TO THE DEVELOPMENT OF SHALLOW SFC BASED INSTABILITY WITH EQUILIBRIUM LEVELS LESS THAN H5 AT MANY LOCATIONS. ALTHOUGH SUBSIDENCE DIMINISHES IN THE AFTERNOON ACROSS SOUTHERN HALF OF CWA...THINKING ANY AFTERNOON SHOWERS WILL BE STRONGLY DIURNALLY DRIVEN AND THINK OVERALL COVERAGE WILL BE FAIRLY LOW THROUGH THE EARLY EVENING. LARGE SCALE ASCENT WILL ONCE AGAIN WITH STRONG LOW LEVEL WAA DEVELOPING IN RESPONSE TO H3 JET STREAK LIFTING NORTH INTO SOUTHERN SOUTH DAKOTA. SEEMS LIKE RECENT SUITE OF MODELS NOT ALL THAT OPTIMISTIC ABOUT BREAKING OUT PRECIPITATION OVERNIGHT...BUT GIVEN STRONG AND PERSISTENT WAA/ISENTROPIC FORCING STRONG MOISTURE TRANSPORT ABOVE THE SFC...AND SMALL CONDENSATION PRESSURE DEFICITS IN AREA OF NEGATIVE THETA E LAPSE RATES...THINK THE THREAT FOR SHOWERS AND STORMS WILL BE THERE DESPITE CURRENT MODEL QPF OUTPUT. FRIDAY-SATURDAY...WARM FRONT WILL SLOWLY LIFT TO THE NORTH THROUGH THE PERIOD AND WILL NOT ONLY PLAY A BIG ROLE ON POTENTIAL FOR THUNDERSTORMS...IT WILL ALSO HAVE A LARGE ROLE IN TEMPERATURE FORECAST AS POSSIBILITY EXISTS FOR A PRETTY SHARP GRADIENT WITH TEMPS ON FRIDAY. SREF PLUME DATA INDICATING NEARLY A 20 DEGREE SPREAD IN TEMPS FOR MOST LOCATIONS...WITH ABOUT EQUAL CLUSTERING ON EITHER SIDE...MAINLY ON FRIDAY. PLAN ON KEEPING NEAR MEAN VALUES FOR FRIDAY...ALTHOUGH THERE IS MUCH MORE AGREEMENT ON VERY WARM TEMPS ON SATURDAY AND HAVE WARMED TEMPS ACCORDINGLY. GIVEN EXPECTED PRESSURE FALL PATTERN AROUND AREA AND LARGE SCALE FORCING FOR ASCENT BECOMING MAXIMIZED WELL TO THE WEST OF THE AREA...DO NOT ANTICIPATE MUCH OF A NORTHERN MOVEMENT OF THE FRONT...WITH BULK OF CWA REMAINING CLOUDY AND COOL THROUGH THE DAY. THINK THUNDERSTORMS WILL LIKELY BE ONGOING THROUGH THE MORNING HOURS AS PREVIOUSLY MENTIONED WAA PATTERN REMAINS IN PLACE THROUGH THE MORNING HOURS...BEFORE LARGE SUBSIDENCE INVERSION STRENGTHENS DURING THE AFTERNOON SHARPLY INCREASING CINH PROFILES AND ADVECTING MUCH DRIER AIR INTO THE AREA. MODELS CONTINUE TO PRODUCE LIGHT PRECIPITATION AFTER THIS POINT...BUT SOUNDINGS LOOK LIKE ANY PRECIPITATION PROCESSES IN THE LATE AFTERNOON OR EVENING LOOK TO BE VERY SHALLOW/DRIZZLE TYPE PROCESSES AND DO NOT PLAN ON GOING ALONG WITH HIGHER GUIDANCE POPS AT THIS TIME. APPEARS TO BE LOTS OF INSTABILITY DURING THE LATE AFTERNOON AND EVENING ALONG/NORTH OF FRONT...BUT CINH LOOKS VERY STRONG AND GIVEN RIDGING ALOFT DO NOT THINK THIS WILL BE OVERCOME. ON SATURDAY...EXPECT WINDY TO VERY WINDY CONDITIONS TO DEVELOP ACROSS MUCH OF THE AREA DURING THE AFTERNOON WITH STRONGEST WINDS BEHIND DRYLINE IN EASTERN COLORADO...WHERE DEEP MIXED LAYER SHOULD TAP INTO STRONG FLOW ALOFT. WITH TEMPS IN THE 90S...WIND GUSTS APPROACHING 50 KTS AND MIXED TDS SUGGESTING A RAPID DROP OFF IN DEWPOINTS...POTENTIAL EXISTS FOR EXTREMELY CRITICAL FIRE WX CONDITIONS TO DEVELOP. IT IS A BIT TOO FAR IN THE FUTURE TO ISSUE ANY HIGHLIGHTS AT THIS POINT...BUT POTENTIAL FOR FIRE WEATHER AND SIGNIFICANT WINDS IS INCREASING. OTHERWISE...WARM FRONT WILL LIFT TO THE NORTH OUT OF THE AREA DURING THE MORNING HOURS WITH ANY POTENTIAL FOR AFTERNOON THUNDERSTORMS ALONG DRYLINE DURING THE LATE AFTERNOON. WITH DEEP MIXING AND BULK OF PRESSURE FALLS TO THE NORTH OF THE AREA...WOULD EXPECT DRYLINE TO MIX EASTWARD WITH BULK OF CWA IN DRY SECTOR. ENOUGH SPREAD EXISTS TO WARRANT A MORE BROAD BRUSHED APPROACH TO CHANCES ATTM THOUGH AND WITH STRONG FLOW ALOFT THERE WILL BE POTENTIAL FOR AT LEAST A FEW STRONG/SEVERE HIGH BASED STORMS IN THE AFTERNOON. IN THE EXTENDED (SAT NIGHT-WEDNESDAY)...ACTIVE WEATHER PATTERN EXPECTED THROUGH THE PERIOD AS MEDIUM RANGE MODELS SHOWING REASONABLE AGREEMENT IN DEVELOPMENT OF STRONG TROUGH/AMPLIFIED PATTERN ACROSS THE PLAINS THROUGH THE WEEKEND...FOLLOWED BY MORE ZONAL FLOW ALOFT DURING THE BEGINNING OF THE WEEK. WHILE 06Z GEFS DATA SHOWS A RELATIVELY CONSISTENT PATTERN WITH LARGE TROUGH IMPACTING THE AREA DURING THE WEEKEND...MODEL SPREAD/UNCERTAINTY INCREASES DURING THE LATER HALF AS THERE APPEARS TO BE A DECENT AMOUNT OF DISCREPANCY WITH SMALL SCALE FEATURES. BEST CHANCE FOR PRECIPITATION WILL LIKELY BE ON SUNDAY AFTERNOON AS COLD FRONT SLOWLY MOVES ACROSS THE AREA PROVIDING AMPLE FORCING TO FOCUS THUNDERSTORM DEVELOPMENT. WITH LIGHT EASTERLY/UPSLOPE FLOW AND SEVERAL FAST MOVING SHORT WAVE TROUGHS MOVING THROUGH ZONAL FLOW...PRECIP CHANCES WILL CONTINUE THROUGH THE MIDDLE OF THE WEEK. ASIDE FROM TIMING WITH FROPA ON SUNDAY BRINGING THE POTENTIAL FOR ONE MORE VERY WARM DAY...LOOKS LIKE COOLER CONDITIONS WILL PREVAIL THROUGH THE START OF THE WEEK AS LIGHT EASTERLY FLOW WILL PREVAIL BEHIND COLD FRONT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1117 PM MDT WED MAY 23 2012 SHOWERS AND THUNDERSTORMS WILL CONTINUE OVERNIGHT AT BOTH KGLD AND KMCK. DO NOT EXPECT CONDITIONS TO DETERIORATE BELOW VFR BUT CANNOT RULE OUT A BRIEF PERIOD OF MVFR NEAR A STRONG THUNDERSTORM. THE SHORTWAVE SHOULD EXIT BY SUNRISE. BROKEN TO SCATTERED MID LEVEL CLOUDS WILL PASS OVER THE REGION THURSDAY. CLOUDS WILL INCREASE AGAIN FRIDAY EVENING WITH A SLIGHT CHANCE OF SOME SHOWERS. && .FIRE WEATHER... ISSUED AT 224 PM MDT WED MAY 23 2012 VERY WINDY CONDITIONS...WITH GUSTS IN EXCESS OF 50 MPH POSSIBLE...ARE EXPECTED ACROSS A LARGE PORTION OF THE AREA ON SATURDAY. AFTERNOON HUMIDITIES WILL FALL TO AROUND 10 PERCENT ACROSS PORTIONS OF EASTERN COLORADO AND ADJACENT AREAS DURING THE AFTERNOON AS THE WINDS INCREASE. THE COMBINATION OF VERY DRY AND VERY WINDY CONDITIONS WILL BRING THE POTENTIAL FOR EXTREMELY CRITICAL CONDITIONS ON SATURDAY. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...FS SHORT TERM...DR LONG TERM...JRM AVIATION...FS FIRE WEATHER...JRM
AREA FORECAST DISCUSSION...CORRECTED
NWS DODGE CITY KS
1255 AM CDT THU MAY 24 2012 ...UPDATED FOR THE 06Z AVIATION TAFS AND DISCUSSION... .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 142 PM CDT WED MAY 23 2012 NAM, RAP, AND HRRR WERE IN DECENT AGREEMENT WITH COLD FRONT EXTENDING FROM NORTH CENTRAL KANSAS INTO EXTREME SOUTHWEST KANSAS LATE THIS AFTERNOON AND EARLY THIS EVENING. THIS FRONT WILL BE LOCATED UNDER +14C TO +16C 700MB TEMPERATURES. IN ADDITION THE BETTER LOW LEVEL MOISTURE IS STILL FORECAST TO BE LOCATED ACROSS CENTRAL KANSAS AND FROM NORTHWEST KANSAS INTO SOUTH CENTRAL NEBRASKA. BASED ON MODEL SOUNDINGS THE WARM MID LEVEL TEMPERATURES LATE TODAY/EARLY TONIGHT APPEARS TO SERVE AS A CAP ACROSS MOST OF SOUTHWEST KANSAS. THE POSSIBLE EXCEPTION WILL BE NEAR AND NORTH OF INTERSTATE 70 IN NORTH CENTRAL KANSAS WERE BETTER LOW LEVEL FRONTOGENESIS AND MOISTURE WILL BE PRESENT. IN ADDITION THIS WILL BE NEAR THE NORTHERN EDGE OF THE WARM MID LEVEL TEMPERATURES. THE NAM EVEN SUGGESTS SOME COOLING OCCURRING IN THE MID LEVEL AFTER 21Z ALONG AND NORTH OF INTERSTATE 70. GIVEN THE COOLER MID LEVEL TEMPERATURES, BETTER LOW LEVEL MOISTURE/FRONTOGENESIS NEAR THE SURFACE BOUNDARY, AND CAPES EARLY TONIGHT GREATER THAN 1000 J/KG WILL GO AHEAD AND KEEP A MENTION OF THUNDERSTORMS NEAR THE SURFACE BOUNDARY. ALSO BASED ON 0-6KM SHEAR FORECAST TO BE AROUND 50 KNOTS ALONG WITH 1000-2000 J/KG THERE WILL BE A CHANCE FOR ANY STORM THAT DOES DEVELOP TO BECOME SEVERE. MAIN HAZARD STILL APPEARS TO BE HAIL UP TO HALF DOLLAR SIZE AND WINDS UP TO 60 MPH. FURTHER WEST...THE CONVECTION DEVELOPING ACROSS NORTHEAST COLORADO IS EXPECTED TO SPREAD EAST EARLY TONIGHT BUT STAY NORTH OF THE INTERSTATE 70 DURING THE OVERNIGHT HOURS. THE COLD POOL THAT IS FORECAST TO DEVELOP WITH THESE STORMS OVERNIGHT SHOULD PUSH THE COLD FRONT SOUTH ACROSS ALL OF SOUTHWEST KANSAS AFTER MIDNIGHT. BY EARLY THURSDAY MORNING THIS COLD FRONT IS EXPECTED TO BE LOCATED ACROSS CENTRAL KANSAS AND NORTHERN OKLAHOMA. BOUNDARY LAYER WINDS BEHIND THIS FRONT ARE FORECAST TO RANGE FROM 30 TO 35 KNOTS AND GIVEN THE TIGHT PRESSURE GRADIENT BEHIND THIS FRONT THE SURFACE WINDS MAY APPROACH ADVISORY CRITERIA FOR A FEW HOURS FOLLOWING THE FRONTAL PASSAGE LATE TONIGHT. AT THIS TIME HAVE DECIDED TO KEEP SUSTAINED WINDS JUST BELOW ADVISORY CRITERIA FOR A FEW HOURS BEHIND THIS FRONT. IN ADDITION TO THE WINDS SOME LOW LEVEL MOISTURE WILL RETURN TO NORTH CENTRAL AND SOUTHWEST KANSAS. THE WRF AND NMM EVEN SUGGESTS SOME LIGHT PRECIPITATION WILL BE POSSIBLE AS THE LOWER LEVELS SATURATES. AT THIS TIME GIVEN THE ISENTROPIC DOWNGLIDE PRESENT AND DEPTH OF THE MOIST LAYER LESS THAN 3000 FEET AM TRENDING AWAY FROM INSERTING PRECIPITATION CHANCES AFTER MIDNIGHT. ON THURSDAY THE GUSTY NORTHWEST WINDS WILL GRADUALLY SUBSIDE BY MID MORNING AS THE COLD FRONT CONTINUES TO MOVE SOUTHEAST ACROSS EASTERN KANSAS AND OKLAHOMA. IN SOUTHEAST COLORADO THIS FRONT IS EXPECTED TO BECOME NEARLY STATIONARY DURING THE DAY WITH SOME ISENTROPIC LIFT/WARM AIR ADVECTION DEVELOPING NORTH OF THIS BOUNDARY BY LATE DAY. THIS MAY BRING AN INCREASE IN MID LEVEL CLOUD COVER LATE DAY TO PORTIONS OF SOUTHWEST KANSAS BASED ON I310 AND I315 ISENTROPIC SURFACES AND 12Z BUFR SOUNDINGS. GIVEN SOME INCREASING CLOUDS LATE DAY AND 850MB TEMPERATURES AT 00Z FRIDAY WILL TREND TOWARDS THE COOLER GUIDANCE IN FAR SOUTHWEST KANSAS NEAR THE OKLAHOMA BORDER WHILE FURTHER NORTH HAVE KEPT HIGHS CLOSER TO THE WARMER 850MB MIX DOWN TEMPERATURES. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 234 PM CDT WED MAY 23 2012 THURSDAY NIGHT: NOT THAT IMPRESSED FOR PROSPECTS OF CONVECTION THURSDAY EVENING. SOME ISENTROPIC LIFT IS EXPECTED ALONG THE 700 HPA BAROCLINIC BOUNDARY ACROSS CENTRAL KANSAS. FORECAST SOUNDINGS FROM THE ECMWF/GFS SHOW THAT THERE MAY BE SOME MID LEVEL CLOUDS, HOWEVER, THE OVERALL PROFILE IS FAIRLY DRY AND CAPPED. WENT AHEAD AND THREW IN SOME SILENT POPS ACROSS MY NORTHERN COUNTIES BUT DISCOUNTED THE WETTER GFS SOLUTION WHICH CONTINUES TO SUFFER FROM OVERALL POOR SYNOPTIC PERFORMANCE. THE 4 KM NAM & ARW/NMM CORES AREN`T TOO CONVINCING EITHER. FRIDAY: THE WARM SECTOR WILL CONTINUE TO SPREAD NORTHWARD DOWNSTREAM OF A SLOWLY PROPAGATING 500 HPA TROUGH FURTHER WEST. TEMPERATURES WARM TO 33 DEG C @ 850 HPA AND 15 DEG C & 700 HPA WITH A WELL MIXED ATMOSPHERE. HAVE WARMED TEMPERATURES TO THE MID TO UPPER 90S DEG F ACROSS THE CENTRAL AND SOUTHERN ZONES AS A RESULT. THE ECMWF IS VERY WARM WITH 102 DEG F FOR DODGE CITY FRIDAY. WILL CONTINUE TO THE TREND UPWARD BUT NOT YET BITE ON THE EXTREME. THERE COULD BE SOME CONVECTION EAST OF THE DRYLINE FRIDAY EVENING BUT WITH SUCH WARM TEMPERATURES AT 700 HPA, WILL NOT GO HIGHER THAN SLIGHT GIVEN THE VERY STOUT EML. ECMWF SHOWS ABOUT 2500 J/KG OF SBCAPE AND 30 TO 40 KT OF SHEAR SO WILL HAVE TO WATCH OUT FOR SEVERE IN LATER FORECASTS. SATURDAY: AMPLIFICATION OF THE WESTERN TROUGH IS EXPECTED SATURDAY. THE 12Z ECMWF IS LESS AGGRESSIVE WITH CONVECTION FOR SATURDAY EVENING ACROSS THE WEST THAN COMPARED TO THE 00Z RUN. THIS IS PROBABLY DUE TO THE CONTINUED STRONG EML FORECAST BY THE MODEL. WILL NOT GO HIGHER THAN SLIGHT POPS IN THE MEANTIME. NOT MUCH UPPER LEVEL SUPPORT AS THE MAIN 250 HPA JET AXIS IS STILL PRETTY FAR WEST. WILL CONTINUE HOT TEMPERATURES IN THE GRIDS WITH MID TO UPPER 90S DEG F EXPECTED ACROSS MUCH OF THE REGION. SUNDAY AND BEYOND: CONVECTIVE PROSPECTS ARE BETTER SUNDAY AS THE RIGHT ENTRANCE REGION OF THE AFOREMENTIONED 250 HPA TRAVERSES ACROSS NW KANSAS. CAA ASSOCIATED WITH THE TROUGH AND LOW TO MID LEVEL COLD POOLS WILL ALLOW FOR A WEAKENING OF THE EML. THE BEST CHANCE FOR CONVECTION APPEARS TO BE ACROSS CENTRAL AND SOUTH CENTRAL KANSAS ALONG AND EASTWARD MIXING DRYLINE. THE THERMODYNAMIC AND KINEMATIC PROFILES ARE SUPPORTIVE OF SEVERE WEATHER. UL FLOW FLATTENS MONDAY AND TUESDAY AS THE ASSOCIATED TROUGH MOVES ACROSS THE CANADIAN PRAIRIES. THIS WILL ALLOW FOR MORE SEASONAL YET ABOVE NORMAL TEMPERATURES ACROSS SW KANSAS. WILL HAVE TO WATCH THE MIDWEEK PERIOD NEXT WEEK AS IT TRANSITIONS INTO MORE OF A MCS PATTERN. DEWPOINTS/MOISTURE COULD BE AN ISSUE THOUGH. HAVE GONE WITH A CLEANED UP VERSION OF ALLBLEND POPS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1233 AM CDT THU MAY 24 2012 AS A FRONT MOVES ACROSS CENTRAL KANSAS, SOUTH WINDS WILL SHIFT TO THE NORTH OR NORTHEAST AND GUST BRIEFLY INTO THE 25 TO 30 KNOT RANGE. AFTER 09Z, EXPECT NORTHWEST WINDS IN THE 15 TO 20 KNOT RANGE. AS HIGH PRESSURE SETTLES SOUTH INTO THE TAF AREAS THURSDAY MORNING, WINDS WILL BECOME NORTHWEST AND WILL SUBSIDE TO AROUND 12 TO 13 KNOTS. THE ONLY CLOUDS EXPECTED ARE HIGH CIRRUS CLOUDS IN THE 150-200 THOUSAND FOOT RANGE, SO VFR CONDITIONS WILL PREVAIL THROUGH THE 24 HOUR TAF PERIOD. && .PRELIMINARY POINT TEMPS/POPS... DDC 62 97 70 97 / 10 10 10 20 GCK 60 96 68 95 / 10 10 10 20 EHA 59 96 66 95 / 10 10 10 20 LBL 62 100 68 96 / 10 10 10 20 HYS 59 86 69 97 / 10 20 20 10 P28 67 97 72 97 / 10 20 20 10 && .DDC WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 4 AM CDT /3 AM MDT/ EARLY THIS MORNING FOR KSZ043-044-061>063-074>077. && $$ SHORT TERM...BURGERT LONG TERM...SUGDEN AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1240 AM CDT THU MAY 24 2012 ...UPDATED FOR THE 06Z AVIATION TAFS AND DISCUSSION... .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 142 PM CDT WED MAY 23 2012 NAM, RAP, AND HRRR WERE IN DECENT AGREEMENT WITH COLD FRONT EXTENDING FROM NORTH CENTRAL KANSAS INTO EXTREME SOUTHWEST KANSAS LATE THIS AFTERNOON AND EARLY THIS EVENING. THIS FRONT WILL BE LOCATED UNDER +14C TO +16C 700MB TEMPERATURES. IN ADDITION THE BETTER LOW LEVEL MOISTURE IS STILL FORECAST TO BE LOCATED ACROSS CENTRAL KANSAS AND FROM NORTHWEST KANSAS INTO SOUTH CENTRAL NEBRASKA. BASED ON MODEL SOUNDINGS THE WARM MID LEVEL TEMPERATURES LATE TODAY/EARLY TONIGHT APPEARS TO SERVE AS A CAP ACROSS MOST OF SOUTHWEST KANSAS. THE POSSIBLE EXCEPTION WILL BE NEAR AND NORTH OF INTERSTATE 70 IN NORTH CENTRAL KANSAS WERE BETTER LOW LEVEL FRONTOGENESIS AND MOISTURE WILL BE PRESENT. IN ADDITION THIS WILL BE NEAR THE NORTHERN EDGE OF THE WARM MID LEVEL TEMPERATURES. THE NAM EVEN SUGGESTS SOME COOLING OCCURRING IN THE MID LEVEL AFTER 21Z ALONG AND NORTH OF INTERSTATE 70. GIVEN THE COOLER MID LEVEL TEMPERATURES, BETTER LOW LEVEL MOISTURE/FRONTOGENESIS NEAR THE SURFACE BOUNDARY, AND CAPES EARLY TONIGHT GREATER THAN 1000 J/KG WILL GO AHEAD AND KEEP A MENTION OF THUNDERSTORMS NEAR THE SURFACE BOUNDARY. ALSO BASED ON 0-6KM SHEAR FORECAST TO BE AROUND 50 KNOTS ALONG WITH 1000-2000 J/KG THERE WILL BE A CHANCE FOR ANY STORM THAT DOES DEVELOP TO BECOME SEVERE. MAIN HAZARD STILL APPEARS TO BE HAIL UP TO HALF DOLLAR SIZE AND WINDS UP TO 60 MPH. FURTHER WEST...THE CONVECTION DEVELOPING ACROSS NORTHEAST COLORADO IS EXPECTED TO SPREAD EAST EARLY TONIGHT BUT STAY NORTH OF THE INTERSTATE 70 DURING THE OVERNIGHT HOURS. THE COLD POOL THAT IS FORECAST TO DEVELOP WITH THESE STORMS OVERNIGHT SHOULD PUSH THE COLD FRONT SOUTH ACROSS ALL OF SOUTHWEST KANSAS AFTER MIDNIGHT. BY EARLY THURSDAY MORNING THIS COLD FRONT IS EXPECTED TO BE LOCATED ACROSS CENTRAL KANSAS AND NORTHERN OKLAHOMA. BOUNDARY LAYER WINDS BEHIND THIS FRONT ARE FORECAST TO RANGE FROM 30 TO 35 KNOTS AND GIVEN THE TIGHT PRESSURE GRADIENT BEHIND THIS FRONT THE SURFACE WINDS MAY APPROACH ADVISORY CRITERIA FOR A FEW HOURS FOLLOWING THE FRONTAL PASSAGE LATE TONIGHT. AT THIS TIME HAVE DECIDED TO KEEP SUSTAINED WINDS JUST BELOW ADVISORY CRITERIA FOR A FEW HOURS BEHIND THIS FRONT. IN ADDITION TO THE WINDS SOME LOW LEVEL MOISTURE WILL RETURN TO NORTH CENTRAL AND SOUTHWEST KANSAS. THE WRF AND NMM EVEN SUGGESTS SOME LIGHT PRECIPITATION WILL BE POSSIBLE AS THE LOWER LEVELS SATURATES. AT THIS TIME GIVEN THE ISENTROPIC DOWNGLIDE PRESENT AND DEPTH OF THE MOIST LAYER LESS THAN 3000 FEET AM TRENDING AWAY FROM INSERTING PRECIPITATION CHANCES AFTER MIDNIGHT. ON THURSDAY THE GUSTY NORTHWEST WINDS WILL GRADUALLY SUBSIDE BY MID MORNING AS THE COLD FRONT CONTINUES TO MOVE SOUTHEAST ACROSS EASTERN KANSAS AND OKLAHOMA. IN SOUTHEAST COLORADO THIS FRONT IS EXPECTED TO BECOME NEARLY STATIONARY DURING THE DAY WITH SOME ISENTROPIC LIFT/WARM AIR ADVECTION DEVELOPING NORTH OF THIS BOUNDARY BY LATE DAY. THIS MAY BRING AN INCREASE IN MID LEVEL CLOUD COVER LATE DAY TO PORTIONS OF SOUTHWEST KANSAS BASED ON I310 AND I315 ISENTROPIC SURFACES AND 12Z BUFR SOUNDINGS. GIVEN SOME INCREASING CLOUDS LATE DAY AND 850MB TEMPERATURES AT 00Z FRIDAY WILL TREND TOWARDS THE COOLER GUIDANCE IN FAR SOUTHWEST KANSAS NEAR THE OKLAHOMA BORDER WHILE FURTHER NORTH HAVE KEPT HIGHS CLOSER TO THE WARMER 850MB MIX DOWN TEMPERATURES. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 234 PM CDT WED MAY 23 2012 THURSDAY NIGHT: NOT THAT IMPRESSED FOR PROSPECTS OF CONVECTION THURSDAY EVENING. SOME ISENTROPIC LIFT IS EXPECTED ALONG THE 700 HPA BAROCLINIC BOUNDARY ACROSS CENTRAL KANSAS. FORECAST SOUNDINGS FROM THE ECMWF/GFS SHOW THAT THERE MAY BE SOME MID LEVEL CLOUDS, HOWEVER, THE OVERALL PROFILE IS FAIRLY DRY AND CAPPED. WENT AHEAD AND THREW IN SOME SILENT POPS ACROSS MY NORTHERN COUNTIES BUT DISCOUNTED THE WETTER GFS SOLUTION WHICH CONTINUES TO SUFFER FROM OVERALL POOR SYNOPTIC PERFORMANCE. THE 4 KM NAM & ARW/NMM CORES AREN`T TOO CONVINCING EITHER. FRIDAY: THE WARM SECTOR WILL CONTINUE TO SPREAD NORTHWARD DOWNSTREAM OF A SLOWLY PROPAGATING 500 HPA TROUGH FURTHER WEST. TEMPERATURES WARM TO 33 DEG C @ 850 HPA AND 15 DEG C & 700 HPA WITH A WELL MIXED ATMOSPHERE. HAVE WARMED TEMPERATURES TO THE MID TO UPPER 90S DEG F ACROSS THE CENTRAL AND SOUTHERN ZONES AS A RESULT. THE ECMWF IS VERY WARM WITH 102 DEG F FOR DODGE CITY FRIDAY. WILL CONTINUE TO THE TREND UPWARD BUT NOT YET BITE ON THE EXTREME. THERE COULD BE SOME CONVECTION EAST OF THE DRYLINE FRIDAY EVENING BUT WITH SUCH WARM TEMPERATURES AT 700 HPA, WILL NOT GO HIGHER THAN SLIGHT GIVEN THE VERY STOUT EML. ECMWF SHOWS ABOUT 2500 J/KG OF SBCAPE AND 30 TO 40 KT OF SHEAR SO WILL HAVE TO WATCH OUT FOR SEVERE IN LATER FORECASTS. SATURDAY: AMPLIFICATION OF THE WESTERN TROUGH IS EXPECTED SATURDAY. THE 12Z ECMWF IS LESS AGGRESSIVE WITH CONVECTION FOR SATURDAY EVENING ACROSS THE WEST THAN COMPARED TO THE 00Z RUN. THIS IS PROBABLY DUE TO THE CONTINUED STRONG EML FORECAST BY THE MODEL. WILL NOT GO HIGHER THAN SLIGHT POPS IN THE MEANTIME. NOT MUCH UPPER LEVEL SUPPORT AS THE MAIN 250 HPA JET AXIS IS STILL PRETTY FAR WEST. WILL CONTINUE HOT TEMPERATURES IN THE GRIDS WITH MID TO UPPER 90S DEG F EXPECTED ACROSS MUCH OF THE REGION. SUNDAY AND BEYOND: CONVECTIVE PROSPECTS ARE BETTER SUNDAY AS THE RIGHT ENTRANCE REGION OF THE AFOREMENTIONED 250 HPA TRAVERSES ACROSS NW KANSAS. CAA ASSOCIATED WITH THE TROUGH AND LOW TO MID LEVEL COLD POOLS WILL ALLOW FOR A WEAKENING OF THE EML. THE BEST CHANCE FOR CONVECTION APPEARS TO BE ACROSS CENTRAL AND SOUTH CENTRAL KANSAS ALONG AND EASTWARD MIXING DRYLINE. THE THERMODYNAMIC AND KINEMATIC PROFILES ARE SUPPORTIVE OF SEVERE WEATHER. UL FLOW FLATTENS MONDAY AND TUESDAY AS THE ASSOCIATED TROUGH MOVES ACROSS THE CANADIAN PRAIRIES. THIS WILL ALLOW FOR MORE SEASONAL YET ABOVE NORMAL TEMPERATURES ACROSS SW KANSAS. WILL HAVE TO WATCH THE MIDWEEK PERIOD NEXT WEEK AS IT TRANSITIONS INTO MORE OF A MCS PATTERN. DEWPOINTS/MOISTURE COULD BE AN ISSUE THOUGH. HAVE GONE WITH A CLEANED UP VERSION OF ALLBLEND POPS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1233 AM CDT THU MAY 24 2012 AS A FRONT MOVES ACROSS CENTRAL KANSAS, SOUTH WINDS WILL SHIFT TO THE NORTH OR NORTHEAST AND GUST BRIEFLY INTO THE 25 TO 30 KNOT RANGE. AFTER 09Z, EXPECT NORTHWEST WINDS IN THE 15 TO 20 KNOT RANGE. AS HIGH PRESSURE SETTLES SOUTH INTO THE TAF AREAS THURSDAY MORNING, WINDS WILL NORTHWEST WINDS WILL SUBSIDE TO AROUND 12 TO 3 KNOTS. THE ONLY CLOUDS EXPECTED ARE HIGH CIRRUS CLOUDS IN THE 150-200 THOUSAND FOOT RANGE, SO VFR CONDITIONS WILL PREVAIL THROUGH THE 24 HOUR TAF PERIOD. && .PRELIMINARY POINT TEMPS/POPS... DDC 62 97 70 97 / 10 10 10 20 GCK 60 96 68 95 / 10 10 10 20 EHA 59 96 66 95 / 10 10 10 20 LBL 62 100 68 96 / 10 10 10 20 HYS 59 86 69 97 / 10 20 20 10 P28 67 97 72 97 / 10 20 20 10 && .DDC WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 4 AM CDT /3 AM MDT/ EARLY THIS MORNING FOR KSZ043-044-061>063-074>077. && $$ SHORT TERM...BURGERT LONG TERM...SUGDEN AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1122 PM MDT WED MAY 23 2012 .SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT) ISSUED AT 1245 PM MDT WED MAY 23 2012 EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW BROAD TROUGH ACROSS THE NORTHERN ROCKIES...WITH WEST/SOUTHWEST FLOW ACROSS THE INTER-MOUNTAIN WEST INTO THE CENTRAL HIGH PLAINS. AT THE SURFACE A COLD FRONT HAS STALLED OVER WESTERN KANSAS...CURRENTLY ACROSS THE EASTERN PART OF THE CWA. A SHORTWAVE TROUGH CURRENTLY OVER THE GREAT BASIN WILL MOVE EAST-NORTHEAST ACROSS NORTH CENTRAL COLORADO AND SOUTHWEST NEBRASKA TONIGHT. SHOWERS/THUNDERSTORMS HAVE ALREADY DEVELOPED AHEAD OF THIS FEATURE ALONG THE FRONT RANGE INTO SOUTHEASTERN WYOMING. THIS ACTIVITY WILL SPREAD SOUTH AND EAST OVER OUR CWA LATER THIS AFTERNOON...WITH COVERAGE INCREASING ACROSS THE NORTHERN PART OF OUR FORECAST AREA THROUGH 06Z. CONVERGENCE ZONE ALONG AND NORTH OF STALLED FRONT COULD ACT AS A FOCUS FOR EARLIER THUNDERSTORM INITIATION LATER THIS AFTERNOON AND EVENING...HOWEVER THIS IS REMOVED FROM LARGE SCALE ASCENT ASSOCIATED WITH SHORTWAVE SO COVERAGE SHOULD BE LIMITED ACROSS THE SOUTH. VERY STRONG SHEAR IS PRESENT ACROSS THE CWA...WITH INSTABILITY DECREASING THE FURTHER NORTH IN THE CWA WHERE TD VALUES IN THE 30-40F RANGE HAVE ADVECTED IN BEHIND THE FRONT. SEVERE CONVECTION SHOULD BE LIMITED TO THE I-70 CORRIDOR THROUGH EARLY EVENING WHERE THE BEST OVERLAP BETWEEN SHEAR/INSTABILITY IS EXPECTED. LATER TONIGHT ELEVATED INSTABILITY COULD COMBINE WITH STRONG UPPER LEVEL DYNAMICS ASSOCIATED WITH THE SHORTWAVE ACROSS SOUTHWEST NEBRASKA TO BRING ADDITIONAL SEVERE CHANCES. SUBSIDENCE QUICKLY BUILDS IN BEHIND DEPARTING SHORTWAVE TROUGH AFTER 06Z...WITH COVERAGE DECREASING FROM THE SOUTHWEST TO THE NORTHEAST THROUGH SUNRISE THURSDAY. .LONG TERM...(THURSDAY THROUGH WEDNESDAY) ISSUED AT 224 PM MDT WED MAY 23 2012 THURSDAY-THURSDAY NIGHT...PV ANOMALY WILL LIFT TO THE NORTH AND EAST OF THE AREA FAIRLY QUICKLY DURING THE MORNING HOURS...WITH MID LEVEL FRONTOGENESIS QUICKLY DIMINISHING AND DEEP LAYER DIV Q FIELDS INDICATE FAIRLY STRONG LARGE SCALE FORCING FOR SUBSIDENCE OVER THE AREA. STILL HAVE A FEW TIMING CONCERNS THOUGH...AND THINK HOLDING ONTO SOME SMALL POPS WARRANTED FOR AT LEAST THE FIRST FEW HOURS OF THE PERIOD. SOUNDINGS SUGGEST THAT WEAK INSTABILITY WILL LINGER ACROSS MUCH OF THE AREA THROUGH THE DAY...AS DIFFERENTIAL TEMP ADVECTION SHOULD LEAD TO THE DEVELOPMENT OF SHALLOW SFC BASED INSTABILITY WITH EQUILIBRIUM LEVELS LESS THAN H5 AT MANY LOCATIONS. ALTHOUGH SUBSIDENCE DIMINISHES IN THE AFTERNOON ACROSS SOUTHERN HALF OF CWA...THINKING ANY AFTERNOON SHOWERS WILL BE STRONGLY DIURNALLY DRIVEN AND THINK OVERALL COVERAGE WILL BE FAIRLY LOW THROUGH THE EARLY EVENING. LARGE SCALE ASCENT WILL ONCE AGAIN WITH STRONG LOW LEVEL WAA DEVELOPING IN RESPONSE TO H3 JET STREAK LIFTING NORTH INTO SOUTHERN SOUTH DAKOTA. SEEMS LIKE RECENT SUITE OF MODELS NOT ALL THAT OPTIMISTIC ABOUT BREAKING OUT PRECIPITATION OVERNIGHT...BUT GIVEN STRONG AND PERSISTENT WAA/ISENTROPIC FORCING STRONG MOISTURE TRANSPORT ABOVE THE SFC...AND SMALL CONDENSATION PRESSURE DEFICITS IN AREA OF NEGATIVE THETA E LAPSE RATES...THINK THE THREAT FOR SHOWERS AND STORMS WILL BE THERE DESPITE CURRENT MODEL QPF OUTPUT. FRIDAY-SATURDAY...WARM FRONT WILL SLOWLY LIFT TO THE NORTH THROUGH THE PERIOD AND WILL NOT ONLY PLAY A BIG ROLE ON POTENTIAL FOR THUNDERSTORMS...IT WILL ALSO HAVE A LARGE ROLE IN TEMPERATURE FORECAST AS POSSIBILITY EXISTS FOR A PRETTY SHARP GRADIENT WITH TEMPS ON FRIDAY. SREF PLUME DATA INDICATING NEARLY A 20 DEGREE SPREAD IN TEMPS FOR MOST LOCATIONS...WITH ABOUT EQUAL CLUSTERING ON EITHER SIDE...MAINLY ON FRIDAY. PLAN ON KEEPING NEAR MEAN VALUES FOR FRIDAY...ALTHOUGH THERE IS MUCH MORE AGREEMENT ON VERY WARM TEMPS ON SATURDAY AND HAVE WARMED TEMPS ACCORDINGLY. GIVEN EXPECTED PRESSURE FALL PATTERN AROUND AREA AND LARGE SCALE FORCING FOR ASCENT BECOMING MAXIMIZED WELL TO THE WEST OF THE AREA...DO NOT ANTICIPATE MUCH OF A NORTHERN MOVEMENT OF THE FRONT...WITH BULK OF CWA REMAINING CLOUDY AND COOL THROUGH THE DAY. THINK THUNDERSTORMS WILL LIKELY BE ONGOING THROUGH THE MORNING HOURS AS PREVIOUSLY MENTIONED WAA PATTERN REMAINS IN PLACE THROUGH THE MORNING HOURS...BEFORE LARGE SUBSIDENCE INVERSION STRENGTHENS DURING THE AFTERNOON SHARPLY INCREASING CINH PROFILES AND ADVECTING MUCH DRIER AIR INTO THE AREA. MODELS CONTINUE TO PRODUCE LIGHT PRECIPITATION AFTER THIS POINT...BUT SOUNDINGS LOOK LIKE ANY PRECIPITATION PROCESSES IN THE LATE AFTERNOON OR EVENING LOOK TO BE VERY SHALLOW/DRIZZLE TYPE PROCESSES AND DO NOT PLAN ON GOING ALONG WITH HIGHER GUIDANCE POPS AT THIS TIME. APPEARS TO BE LOTS OF INSTABILITY DURING THE LATE AFTERNOON AND EVENING ALONG/NORTH OF FRONT...BUT CINH LOOKS VERY STRONG AND GIVEN RIDGING ALOFT DO NOT THINK THIS WILL BE OVERCOME. ON SATURDAY...EXPECT WINDY TO VERY WINDY CONDITIONS TO DEVELOP ACROSS MUCH OF THE AREA DURING THE AFTERNOON WITH STRONGEST WINDS BEHIND DRYLINE IN EASTERN COLORADO...WHERE DEEP MIXED LAYER SHOULD TAP INTO STRONG FLOW ALOFT. WITH TEMPS IN THE 90S...WIND GUSTS APPROACHING 50 KTS AND MIXED TDS SUGGESTING A RAPID DROP OFF IN DEWPOINTS...POTENTIAL EXISTS FOR EXTREMELY CRITICAL FIRE WX CONDITIONS TO DEVELOP. IT IS A BIT TOO FAR IN THE FUTURE TO ISSUE ANY HIGHLIGHTS AT THIS POINT...BUT POTENTIAL FOR FIRE WEATHER AND SIGNIFICANT WINDS IS INCREASING. OTHERWISE...WARM FRONT WILL LIFT TO THE NORTH OUT OF THE AREA DURING THE MORNING HOURS WITH ANY POTENTIAL FOR AFTERNOON THUNDERSTORMS ALONG DRYLINE DURING THE LATE AFTERNOON. WITH DEEP MIXING AND BULK OF PRESSURE FALLS TO THE NORTH OF THE AREA...WOULD EXPECT DRYLINE TO MIX EASTWARD WITH BULK OF CWA IN DRY SECTOR. ENOUGH SPREAD EXISTS TO WARRANT A MORE BROAD BRUSHED APPROACH TO CHANCES ATTM THOUGH AND WITH STRONG FLOW ALOFT THERE WILL BE POTENTIAL FOR AT LEAST A FEW STRONG/SEVERE HIGH BASED STORMS IN THE AFTERNOON. IN THE EXTENDED (SAT NIGHT-WEDNESDAY)...ACTIVE WEATHER PATTERN EXPECTED THROUGH THE PERIOD AS MEDIUM RANGE MODELS SHOWING REASONABLE AGREEMENT IN DEVELOPMENT OF STRONG TROUGH/AMPLIFIED PATTERN ACROSS THE PLAINS THROUGH THE WEEKEND...FOLLOWED BY MORE ZONAL FLOW ALOFT DURING THE BEGINNING OF THE WEEK. WHILE 06Z GEFS DATA SHOWS A RELATIVELY CONSISTENT PATTERN WITH LARGE TROUGH IMPACTING THE AREA DURING THE WEEKEND...MODEL SPREAD/UNCERTAINTY INCREASES DURING THE LATER HALF AS THERE APPEARS TO BE A DECENT AMOUNT OF DISCREPANCY WITH SMALL SCALE FEATURES. BEST CHANCE FOR PRECIPITATION WILL LIKELY BE ON SUNDAY AFTERNOON AS COLD FRONT SLOWLY MOVES ACROSS THE AREA PROVIDING AMPLE FORCING TO FOCUS THUNDERSTORM DEVELOPMENT. WITH LIGHT EASTERLY/UPSLOPE FLOW AND SEVERAL FAST MOVING SHORT WAVE TROUGHS MOVING THROUGH ZONAL FLOW...PRECIP CHANCES WILL CONTINUE THROUGH THE MIDDLE OF THE WEEK. ASIDE FROM TIMING WITH FROPA ON SUNDAY BRINGING THE POTENTIAL FOR ONE MORE VERY WARM DAY...LOOKS LIKE COOLER CONDITIONS WILL PREVAIL THROUGH THE START OF THE WEEK AS LIGHT EASTERLY FLOW WILL PREVAIL BEHIND COLD FRONT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1117 PM MDT WED MAY 23 2012 SHOWERS AND THUNDERSTORMS WILL CONTINUE OVERNIGHT AT BOTH KGLD AND KMCK. DO NOT EXPECT CONDITIONS TO DETERIORATE BELOW VFR BUT CANNOT RULE OUT A BRIEF PERIOD OF MVFR NEAR A STRONG THUNDERSTORM. THE SHORTWAVE SHOULD EXIT BY SUNRISE. BROKEN TO SCATTERED MID LEVEL CLOUDS WILL PASS OVER THE REGION THURSDAY. CLOUDS WILL INCREASE AGAIN FRIDAY EVENING WITH A SLIGHT CHANCE OF SOME SHOWERS. && .FIRE WEATHER... ISSUED AT 224 PM MDT WED MAY 23 2012 VERY WINDY CONDITIONS...WITH GUSTS IN EXCESS OF 50 MPH POSSIBLE...ARE EXPECTED ACROSS A LARGE PORTION OF THE AREA ON SATURDAY. AFTERNOON HUMIDITIES WILL FALL TO AROUND 10 PERCENT ACROSS PORTIONS OF EASTERN COLORADO AND ADJACENT AREAS DURING THE AFTERNOON AS THE WINDS INCREASE. THE COMBINATION OF VERY DRY AND VERY WINDY CONDITIONS WILL BRING THE POTENTIAL FOR EXTREMELY CRITICAL CONDITIONS ON SATURDAY. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...JRM AVIATION...FS FIRE WEATHER...JRM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
602 AM EDT THU MAY 24 2012 .SYNOPSIS... ISSUED AT 504 AM EDT THU MAY 24 2012 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW HI AMPLITUDE UPR RDG OVER THE NE CONUS/SE CANADA DOWNSTREAM OF DEEP UPR TROF IN THE ROCKIES. UNDER THE SW FLOW ALF BTWN THESE LARGER SCALE FEATURES...A SHRTWV/SFC LO LIFTING NEWD NEAR LK WINNIPEG WITH UPR DVGC IN RRQ OF SUPPORTING 100KT H3 JET MAX HAS CAUSED QUITE A BIT OF SHRA/TS IN MN MAINLY WITHIN AXIS OF DEEPER MSTR ON THE COLD SIDE OF SFC FNT OVER WRN LK SUP THAT IS ATTENDANT TO LK WINNIPEG LO. A FEW -SHRA/A LTG STRIKE OF TWO ARE JUST W OF IWD NEAR THE SFC COLD FNT LOCATION NOT FAR FM ASHLAND IN NW WI. TO THE E OVER MOST OF THE CWA...BONE DRY AIRMASS SHOWN ON THE 00Z GRB RAOB /PWAT 0.25 INCH WITH KINX -53/ IS BRINGING A TRANQUIL OVERNGT WITH JUST SOME SCT HI CLDS. THE APRCH OF ANOTHER STRONG SHRTWV ROTATING THRU THE WRN TROF IS CAUSING MORE SHRA/TS TO BREAK OUT IN NEBRASKA UNDER EXPANDING AREA OF COOLING CLD TOPS. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 504 AM EDT THU MAY 24 2012 MAIN FCST CONCERN DURING THIS TIME IS POTENTIAL FOR SVR WX LATE THIS EVNG ASSOCIATED WITH SHRTWV NOW ROUNDING THE BASE OF THE WRN TROF AND CAUSING EXPANDING AREA OF SHRA/TS AROUND NEBRASKA. TDAY...ALTHOUGH SOME OF THE SCT -SHRA NOW ALONG THE COLD FNT WL DRIFT INTO THE WRN ZNS EARLY THIS MRNG PER SLOWLY VEERING H85 FLOW TO SW AS SHOWN BY THE 00Z NAM...THE BULK OF THE RA NOW IN MN WL STAY W AND DIMINISH AS POCKET OF UPR DVGC IN RRQ OF JET MAX IN NW ONTARIO LIFTS TO THE NE. BUT WITH DRYNESS OF AIRMASS IN PLACE PER THE 00Z GRB RAOB AND HI AMPLITUDE RDG JUST TO THE E...THESE -SHRA SHOULD REMAIN OVER THE W AS THE SLOW MOVING COLD FNT STALLS WITH BACKING OF THE UPR FLOW ASSOCIATED WITH MOTION OF ROCKIES SHRTWV INTO THE PLAINS. THEN MOST OF THE DAY WILL FEATURE A GUSTY S WIND AS H85 WINDS INCRS TO 40-45KTS IN ADVANCE OF THE SHRTWV/DVLPG SFC LO IN THE PLAINS THAT IS FCST TO LIFT NEWD TO NOT FAR FM DLH BY 00Z. CONFINED CHC POPS TO THE W. DAYTIME HEATING/MIXING WL CAUSE WIND GUSTS TO AT LEAST APRCH ADVY CRITERIA WITH STEEP LLVL LAPSE RATES AS HI TEMPS SURGE INTO THE 80S AT SOME PLACES AWAY FM THE MODERATING INFLUENCE OF MAINLY LK MI. AFT COORDINATION WITH GRB...OPTED TO ISSUE WIND ADVY FOR MAINLY THE W HALF OF THE CWA AWAY FM THE MORE STABILIZED KEWEENAW PENINSULA TO ACCOUNT FOR DEEP MIXING...EXCEPTIONAL INTENSITY OF THE APRCHG DISTURBANCE/SFC LO PRES...AND GFS FCST H85/H925 S WINDS UP TO 60KTS/50KTS. GFS BUFKIT PROFILES INDICATE WINDS OF 35-40 KTS WL BE PRESENT IN MIXED LYR AT IWD. ALTHOUGH THE ARRIVAL OF HIER H95-9 SPECIFIC HUMIDITY IN THIS STRENGTHENING SLY FLOW WL KEEP MIN RH FM FALLING TO CRITICAL LVLS...THE GUSTY S WINDS WL STILL BE A CHALLENGE FOR THE PERSONNEL FIGHTING THE SENEY FIRE/OTHER WILDFIRES. MORE NMRS SHRA/TS ASSOCIATED WITH THE LO MOVING NEAR DLH MAY ARRIVE OVER THE FAR W IN THE 21Z-24Z TIME. TNGT...AS THE NEGATIVELY TILTED SHRTWV/SFC LO MOVE QUICKLY NE INTO ONTARIO...EXPECT A STRONG COLD FROPA ACRS THE CWA. VERY STRONG DYNAMICS THAT IMPACT MAINLY THE W HALF INCLUDE VIGOROUS DPVA/UPR DVGC IN THE LEFT EXIT OF SUPPORTING 130KT H3 JET MAX. ALTHOUGH FCST SDNGS DO NOT SHOW PARTICULARLY STEEP MID LVL LAPSE RATES...INVERTED V LOOK TO THE T/TD PROFILE IN THE SUB H8-85 LYR FOR IWD AT 00Z WITH EARLY EVNG FROPA THERE MAXIMIZING LLVL DESTABLIZATION AT PEAK HEATING TIME SUG THE POTENTIAL FOR DAMAGING WINDS WITH UNIDIRECTIONAL/SLOWLY VEERING POWERFUL FLOW THAT INCLUDES H7/H85 WINDS AS HI AS 60-70KTS/50-60KTS EVEN THOUGH THERE IS NOT A LOT OF MID LVL DRY AIR TO MAXIMIZE DCAPE. DESPITE THE STRONG WIND FIELDS...INVERTED V LLVL T/TD PROFILE AND LACK OF DIRECTIONAL SHEAR WOULD TEND TO MINIMIZE TORNADO THREAT. SINCE THE MID LVL LAPSE RATES ARE RELATIVELY WEAK AND LACK OF DRY MID LVL AIR RESULTS IN WBZ HGT IN THE 12.5-13.0K RANGE...THE LARGE HAIL THREAT DOES NOT APPEAR TOO HI. SINCE THE SHARPER DYNAMICS WL EXIT TO THE NE AND NOCTURNAL COOLING WL BEGIN TO HAVE AN IMPACT...EXPECT THE SHRA/TS CHCS AND SEVERE WX THREAT TO WANE AS THE FRONT MARCHES FARTHER E. VIGOROUS DRY SLOTTING/ARRIVAL OF LARGER SCALE QVECTOR DVGC IN THE WAKE OF THE FROPA WL CAUSE DIMINISHING POPS...BUT LINGERING LLVL MSTR MAY STILL CAUSE A FEW -SHRA IN THE UPSLOPE AREAS OF THE W THRU THE NGT. GIVEN STRENGTH OF THIS DISTURBANCE...CONCERNED W WINDS IN THE WAKE OF THE COLD FROPA WL REACH ADVY CRITERIA OVER MAINLY THE EXPOSED KEWEENAW PENINSULA AFT 06Z WITH W H925 WINDS INCRSG TO 40-50 KTS/VIGOROUS CAD THAT WL MAINTAIN STEEPER LLVL LAPSE RATES DESPITE SOME STABILIZATION OVER THE RELATIVELY COOL WATERS OF LK SUP/AND APRCH OF PRES RISE MAX OF 10-15MB/6HRS THAT WL ACCENTUATE ISALLOBARIC WIND COMPONENT NEARLY IN LINE WITH GRADIENT FLOW. FRI...WITH THE ARRIVAL OF DRIER AIR AND APRCH OF UPR RDG...EXPECT A DRY DAY. GUSTY WINDS WL PERSIST WITH DAYTIME HEATING/MIXING EVEN THOUGH THE PRES GRADIENT IS FCST TO SLOWLY SLACKEN. WITH H85 TEMPS TOPPING OUT IN THE 8-10C RANGE...MIXING TO H75 ON GFS/NAM FCST SDNGS YIELD HI TEMPS IN THE 75-80 RANGE WITH DOWNSLOPING FLOW AWAY FM LK MODERATION IN LLVL WNW FLOW. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 427 PM EDT WED MAY 23 2012 MAIN CONCERN FOR THE LONG TERM PERIOD IS THE SEVERE WEATHER POTENTIAL AT THE BEGINNING OF THE PERIOD. STATIONARY FRONT WILL BE SETUP OVER WRN LK SUPERIOR...WHILE A FAIRLY POTENT SHORTWAVE PUSHING NE ACROSS AT LEAST THE WRN HALF OF THE CWA THURS NIGHT. THIS WILL LEAD TO ONGOING CYCLOGENESIS OVER NW WI DURING THE LATE AFTERNOON AND THE LOW MOVING NNE ACROSS WRN LK SUPERIOR DURING THE EVENING. EXPECT THUNDERSTORMS TO BE ONGOING OVER NW WI AND FAR WRN LK SUPERIOR AT THE START OF THE PERIOD AND THEN MOVE E AND NE AS THE COLD FRONT PUSHES THROUGH THE CWA DURING THE NIGHT. WITH THE STRONG WINDS ALOFT AND THE CYCLOGENESIS...FEEL THAT THERE IS A DECENT CHANCE OF SEVERE WEATHER OVER THE WRN HALF OF THE CWA TOMORROW EVENING. THERE IS A VERY THIN CORRIDOR OF MLCAPE VALUES APPROACHING 500-1000 J/KG OVER THE WRN THIRD OF THE CWA AND INSTABILITY MAY BE THE MAIN LIMITING FACTOR AS STORMS MOVE INTO THE CWA. CAPE FAIRLY SKINNY...NCAPE VALUES AROUND 0.1...SO DON/T EXPECT MUCH MORE THAN MARGINALLY SEVERE HAIL. WIND APPEARS TO BE BIGGEST THREAT WITH THE STORMS. INVERTED V LOOK TO THE SOUNDINGS OVER THE WEST AND DCAPE VALUES OF 600-800 J/KG. STRONG WINDS ALOFT...APPROACHING 70-80KTS AT H700 AND 40-50KTS JUST A COUPLE HUNDRED FEET ABOVE THE SFC...WILL BE AIDED BY A POCKET OF DRY H700-500 AIR AND STEEPER LAPSE RATES. THIS...COMBINED WITH STORM MOTION TO THE NNE AT 65-70KTS ALL POINT TO THE POTENTIAL FOR DAMAGING WINDS WHERE THUNDERSTORMS...AND POTENTIALLY EVEN SHOWERS OCCUR. WITH THE LOW DEVELOPING ALONG THE FRONT POTENTIALLY AFFECTING THE LLVL WIND FIELD...COULD SEE SOME LLVL BACKING OF THE WINDS AND PRODUCE SOME ROTATING UPDRAFTS AND SUPERCELLS...ESPECIALLY OVER NW WI. BUT THE EXPECTED DRY LLVL AIR HELPING PRODUCE AN INVERTED V AND LCL HEIGHTS TOWARDS 3-3.5KFT SHOULD LIMIT TORNADO POTENTIAL THIS FAR N. CURRENT THOUGHT IS BEST CHANCES FOR SEVERE SHOULD BE FROM BARAGA/IRON COUNTIES AND WEST...BUT WITH THE STORM MOTIONS...COULD POTENTIALLY AFFECT MARQUETTE/DICKINSON/MENOMINEE COUNTIES BEFORE HEADING OVER LK SUPERIOR. ADDED DAMAGING WIND THREAT TO THE GRIDS AND MENTIONED IN THE HWO. THIS MATCHES UP WELL WHERE SPC HAS A SLIGHT RISK...WITH HATCHED AREA JUST TO THE SW OF THE CWA. AS THE LOW QUICKLY LIFTS NE...EXPECT BEST FORCING TO QUICKLY DEPART OVERNIGHT AND PULL FORCING WITH IT. IN ADDITION...AS THE COLD FRONT PUSHES EAST INTO THE CNTRL/ERN CWA...THE CAPPING BECOMES STRONGER. WITH THE COMBINATION OF LOOSING FORCING AND MORE UNFAVORABLE ENVIRONMENT...EXPECT THE SHOWERS/THUNDERSTORMS TO DIMINISH AS THEY MOVE INTO THE CNTRL/ERN CWA. 09Z SREF ALSO SHOWING THIS DIMINISHING TREND IN THE 3HR CALIBRATED THUNDERSTORM PROBS...AS THE SHOWERS/THUNDERSTORMS PUSH TO THE NE OVER LK SUPERIOR DURING THE OVERNIGHT HOURS. EXPECT GUSTY SE WINDS IN THE EVENING AHEAD OF THE LOW AND OVER THE KEWEENAW OVERNIGHT BEHIND THE LOW/FRONT. BUMPED UP WINDS SIGNIFICANTLY OVER THE KEWEENAW BEHIND THE LOW AND FRONT...WITH THE STRONG WINDS JUST ABOVE THE SFC /NAM SHOWING 60KTS AT 1.5KFT/. IN ADDITION...GOOD ISALLOBARIC COMPONENT TO THE WINDS OVER THE WEST OVERNIGHT WITH THE INTENSIFYING LOW PUSHING NE. ONLY CONCERN FOR GOING MORE THAN 30-35KTS AT THIS POINT IS AFFECT OF COOLER WATER TEMPS...BUT THAT MAY NOT HAVE MUCH EFFECT OVER THE HIGHER TERRAIN. FRI...GUSTY WRLY WINDS...30-35KTS...IN THE MORNING BEHIND THE LOW. DRIER AIR MOVING IN AND H700 CAP SHOULD LIMIT DEVELOPMENT EVEN WITH WEAK MID-LVL WAVE MOVING THROUGH. DEEP MOISTURE IS LIMITED AND ML/MU CAPE VALUES ARE BELOW 100 JKG WOULD LEAD TO LITTLE/NO PCPN CHANCES. LATEST NAM RUN HAS BACKED OFF ON PCPN AND WILL FOLLOW SUIT WITH REMOVING SLIGHT CHANCES. WILL KEEP SKIES PARTLY/MOSTLY CLOUDY DURING THE AFTN WITH EXPECTED DIURNAL CU DEVELOPMENT. MIXING TO H750 WOULD YIELD HIGHS IN THE 70S...WITH THE HIGHEST VALUES IN THE FAVORED DOWNSLOPE AREAS OF THE CNTRL. WITH THE GUSTY WINDS AND DEEPER MIXING INTO THE LIMITED MOISTURE ALOFT...EXPECT RH VALUES TO FALL TO 30 PERCENT. FIRE WX CONCERNS MAINLY OVER THE CNTRL...WHERE LESS RAIN IS EXPECTED ON THURS NIGHT. FRI NIGHT...WEAK HIGH PRESSURE RIDGE FROM HIGH JUST N OF MN. SFC LOW DEVELOPING IN THE CNTRL PLAINS IN RESPONSE TO DEEP UPPER TROUGH OVER THE WRN CONUS WILL BEGIN TO PUSH A WARM FRONT N TOWARDS THE UPPER GREAT LAKES LATE FRI NIGHT. COULD PRODUCE A FEW SHOWERS TOWARDS THE WI BORDER LATE. CWA WILL BE ON THE E SIDE OF THE UPPER RIDGE AXIS STRETCHING FROM THE OHIO VALLEY TO LK WINNIPEG UNTIL SUN NIGHT. STILL SEVERAL WEAK DISTURBANCES PUSHING THROUGH THE FLOW SAT AFTN THROUGH SUN NIGHT. THE WARM FRONT WILL CONTINUE TO SLOWLY PUSH NE ON SAT...AS IT BATTLES THE HIGH THAT WILL HAVE MOVED EAST OVER ONTARIO. PCPN CHANCES ON SAT WILL LARGELY DEPEND ON HOW FAR N THE FRONT WILL PUSH. BEST CHANCES LOOK TO BE ON SAT NIGHT INTO SUN...AS THE FRONT MOVES INTO NRN WI AND FINALLY INTO UPPER MI BY SUN AFTN. THIS WILL PUT THE BEST WAA FOCUS OVER THE CWA. THERE ARE DECENT MID LEVEL LAPSE RATES...BUT ELEVATED CAPES ARE NOT TOO IMPRESSIVE...SO HAVE CAPPED THUNDER TO CHANCES FOR SAT NIGHT INTO SUN. WITH THE CONVECTION LIKELY TO BE ELEVATED...THE MAIN THREAT WOULD BE SMALL HAIL AND HEAVY RAIN. CWA WILL BE UNDER THE WARM SECTOR LATE SUN AFTN AND INTO SUN NIGHT...WITH MODELS DIVERGING WITH THE HANDLING OF THE LOW HEADING INTO THE FIRST PART OF NEXT WEEK. 12Z GFS SHOWS THE LOW CONTINUING NNE INTO SRN CANADA ON SUN NIGHT AND MONDAY WHILE PUSHING COLD FRONT ACROSS UPPER MI ON MON. 00Z ECMWF ON THE OTHERHAND DISSIPATES THE LOW OVER THE CWA AND THEN SLOWLY SLIDES IT EAST THROUGH TUES. AFTER A MORE ACTIVE PERIOD...OVERALL TREND LOOKS TO BE TOWARDS A SLIGHTLY DRIER/QUIET WEATHER TOWARDS THE MIDDLE OF NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 557 AM EDT THU MAY 24 2012 STRONG WINDS AND LLWS REMAIN A CONCERN THROUGH 12Z FRIDAY. SSW WINDS OF 50-55KTS CONTINUE TO SHOW UP ON THE MARQUETTE 88D RADAR...WHICH SHOULD ONLY TEMPORARILY DIMINISH ABOUT 5KTS OR SO BEFORE PICKING UP AGAIN THIS AFTERNOON...WITH 60KTS JUST AHEAD OF THE NEARING COLD FRONT TO OUR WEST. SHOWERS AND THUNDERSTORMS NEAR IWD AND CMX EARLY THIS MORNING WILL SLOWLY TRACK TO SAW AROUND OR SHORTLY AFTER 00Z FRIDAY. STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE ALONG THE COLD FRONT DURING THE AFTERNOON AND EVENING WITH CONVECTION...BEFORE DIMINISHING LATE TONIGHT. STRONG WINDS WILL REMAIN ALOFT...IF NOT AT THE SURFACE. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 427 PM EDT WED MAY 23 2012 LOW PRESSURE OVER S MANITOBA WILL PUSH INTO ONTARIO TONIGHT AND THURSDAY...AS AN ADDITIONAL LOW MOVES FROM THE CENTRAL PLAINS TO W LS FRIDAY AFTERNOON. EXPECT THE LOW TO CONTINUE A NE TRACK ACROSS ONTARIO THROUGH FRIDAY...WITH A TROUGH LINGERING ACROSS LAKE SUPERIOR. STRENGTHENING S WINDS WILL PREVAIL AHEAD OF THIS SYSTEM TONIGHT THROUGH THURSDAY. WITH A STABLE TEMPERATURE PROFILE THE STRONGEST WINDS...EXPECT THE STRONGEST ACROSS THE TALLER OBSERVING PLATFORMS ACROSS CENTRAL LAKE SUPERIOR. HIGH PRESSURE OVER CENTRAL CANADA FRIDAY NIGHT WILL SLIDE ACROSS ONTARIO SATURDAY...BEFORE SETTLING ACROSS HUDSON BAY ON SUNDAY. AS A RESULT...A RIDGE WILL SLIDE ACROSS LS SATURDAY...WITH LIGHTER WINDS TAKING HOLD. A LOW ACROSS THE CENTRAL PLAINS WILL FILL ACROSS MN SUNDAY INTO SUNDAY NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WIND ADVISORY FROM 1 PM EDT /NOON CDT/ THIS AFTERNOON TO 8 PM EDT /7 PM CDT/ THIS EVENING FOR MIZ002-004-005-009>011-084. LAKE SUPERIOR... GALE WATCH FROM LATE TONIGHT THROUGH FRIDAY MORNING FOR LSZ263- 264-266. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...KC SHORT TERM...KC LONG TERM...SRF AVIATION...KF MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
505 AM EDT THU MAY 24 2012 .SYNOPSIS... ISSUED AT 504 AM EDT THU MAY 24 2012 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW HI AMPLITUDE UPR RDG OVER THE NE CONUS/SE CANADA DOWNSTREAM OF DEEP UPR TROF IN THE ROCKIES. UNDER THE SW FLOW ALF BTWN THESE LARGER SCALE FEATURES...A SHRTWV/SFC LO LIFTING NEWD NEAR LK WINNIPEG WITH UPR DVGC IN RRQ OF SUPPORTING 100KT H3 JET MAX HAS CAUSED QUITE A BIT OF SHRA/TS IN MN MAINLY WITHIN AXIS OF DEEPER MSTR ON THE COLD SIDE OF SFC FNT OVER WRN LK SUP THAT IS ATTENDANT TO LK WINNIPEG LO. A FEW -SHRA/A LTG STRIKE OF TWO ARE JUST W OF IWD NEAR THE SFC COLD FNT LOCATION NOT FAR FM ASHLAND IN NW WI. TO THE E OVER MOST OF THE CWA...BONE DRY AIRMASS SHOWN ON THE 00Z GRB RAOB /PWAT 0.25 INCH WITH KINX -53/ IS BRINGING A TRANQUIL OVERNGT WITH JUST SOME SCT HI CLDS. THE APRCH OF ANOTHER STRONG SHRTWV ROTATING THRU THE WRN TROF IS CAUSING MORE SHRA/TS TO BREAK OUT IN NEBRASKA UNDER EXPANDING AREA OF COOLING CLD TOPS. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 504 AM EDT THU MAY 24 2012 MAIN FCST CONCERN DURING THIS TIME IS POTENTIAL FOR SVR WX LATE THIS EVNG ASSOCIATED WITH SHRTWV NOW ROUNDING THE BASE OF THE WRN TROF AND CAUSING EXPANDING AREA OF SHRA/TS AROUND NEBRASKA. TDAY...ALTHOUGH SOME OF THE SCT -SHRA NOW ALONG THE COLD FNT WL DRIFT INTO THE WRN ZNS EARLY THIS MRNG PER SLOWLY VEERING H85 FLOW TO SW AS SHOWN BY THE 00Z NAM...THE BULK OF THE RA NOW IN MN WL STAY W AND DIMINISH AS POCKET OF UPR DVGC IN RRQ OF JET MAX IN NW ONTARIO LIFTS TO THE NE. BUT WITH DRYNESS OF AIRMASS IN PLACE PER THE 00Z GRB RAOB AND HI AMPLITUDE RDG JUST TO THE E...THESE -SHRA SHOULD REMAIN OVER THE W AS THE SLOW MOVING COLD FNT STALLS WITH BACKING OF THE UPR FLOW ASSOCIATED WITH MOTION OF ROCKIES SHRTWV INTO THE PLAINS. THEN MOST OF THE DAY WILL FEATURE A GUSTY S WIND AS H85 WINDS INCRS TO 40-45KTS IN ADVANCE OF THE SHRTWV/DVLPG SFC LO IN THE PLAINS THAT IS FCST TO LIFT NEWD TO NOT FAR FM DLH BY 00Z. CONFINED CHC POPS TO THE W. DAYTIME HEATING/MIXING WL CAUSE WIND GUSTS TO AT LEAST APRCH ADVY CRITERIA WITH STEEP LLVL LAPSE RATES AS HI TEMPS SURGE INTO THE 80S AT SOME PLACES AWAY FM THE MODERATING INFLUENCE OF MAINLY LK MI. AFT COORDINATION WITH GRB...OPTED TO ISSUE WIND ADVY FOR MAINLY THE W HALF OF THE CWA AWAY FM THE MORE STABILIZED KEWEENAW PENINSULA TO ACCOUNT FOR DEEP MIXING...EXCEPTIONAL INTENSITY OF THE APRCHG DISTURBANCE/SFC LO PRES...AND GFS FCST H85/H925 S WINDS UP TO 60KTS/50KTS. GFS BUFKIT PROFILES INDICATE WINDS OF 35-40 KTS WL BE PRESENT IN MIXED LYR AT IWD. ALTHOUGH THE ARRIVAL OF HIER H95-9 SPECIFIC HUMIDITY IN THIS STRENGTHENING SLY FLOW WL KEEP MIN RH FM FALLING TO CRITICAL LVLS...THE GUSTY S WINDS WL STILL BE A CHALLENGE FOR THE PERSONNEL FIGHTING THE SENEY FIRE/OTHER WILDFIRES. MORE NMRS SHRA/TS ASSOCIATED WITH THE LO MOVING NEAR DLH MAY ARRIVE OVER THE FAR W IN THE 21Z-24Z TIME. TNGT...AS THE NEGATIVELY TILTED SHRTWV/SFC LO MOVE QUICKLY NE INTO ONTARIO...EXPECT A STRONG COLD FROPA ACRS THE CWA. VERY STRONG DYNAMICS THAT IMPACT MAINLY THE W HALF INCLUDE VIGOROUS DPVA/UPR DVGC IN THE LEFT EXIT OF SUPPORTING 130KT H3 JET MAX. ALTHOUGH FCST SDNGS DO NOT SHOW PARTICULARLY STEEP MID LVL LAPSE RATES...INVERTED V LOOK TO THE T/TD PROFILE IN THE SUB H8-85 LYR FOR IWD AT 00Z WITH EARLY EVNG FROPA THERE MAXIMIZING LLVL DESTABLIZATION AT PEAK HEATING TIME SUG THE POTENTIAL FOR DAMAGING WINDS WITH UNIDIRECTIONAL/SLOWLY VEERING POWERFUL FLOW THAT INCLUDES H7/H85 WINDS AS HI AS 60-70KTS/50-60KTS EVEN THOUGH THERE IS NOT A LOT OF MID LVL DRY AIR TO MAXIMIZE DCAPE. DESPITE THE STRONG WIND FIELDS...INVERTED V LLVL T/TD PROFILE AND LACK OF DIRECTIONAL SHEAR WOULD TEND TO MINIMIZE TORNADO THREAT. SINCE THE MID LVL LAPSE RATES ARE RELATIVELY WEAK AND LACK OF DRY MID LVL AIR RESULTS IN WBZ HGT IN THE 12.5-13.0K RANGE...THE LARGE HAIL THREAT DOES NOT APPEAR TOO HI. SINCE THE SHARPER DYNAMICS WL EXIT TO THE NE AND NOCTURNAL COOLING WL BEGIN TO HAVE AN IMPACT...EXPECT THE SHRA/TS CHCS AND SEVERE WX THREAT TO WANE AS THE FRONT MARCHES FARTHER E. VIGOROUS DRY SLOTTING/ARRIVAL OF LARGER SCALE QVECTOR DVGC IN THE WAKE OF THE FROPA WL CAUSE DIMINISHING POPS...BUT LINGERING LLVL MSTR MAY STILL CAUSE A FEW -SHRA IN THE UPSLOPE AREAS OF THE W THRU THE NGT. GIVEN STRENGTH OF THIS DISTURBANCE...CONCERNED W WINDS IN THE WAKE OF THE COLD FROPA WL REACH ADVY CRITERIA OVER MAINLY THE EXPOSED KEWEENAW PENINSULA AFT 06Z WITH W H925 WINDS INCRSG TO 40-50 KTS/VIGOROUS CAD THAT WL MAINTAIN STEEPER LLVL LAPSE RATES DESPITE SOME STABILIZATION OVER THE RELATIVELY COOL WATERS OF LK SUP/AND APRCH OF PRES RISE MAX OF 10-15MB/6HRS THAT WL ACCENTUATE ISALLOBARIC WIND COMPONENT NEARLY IN LINE WITH GRADIENT FLOW. FRI...WITH THE ARRIVAL OF DRIER AIR AND APRCH OF UPR RDG...EXPECT A DRY DAY. GUSTY WINDS WL PERSIST WITH DAYTIME HEATING/MIXING EVEN THOUGH THE PRES GRADIENT IS FCST TO SLOWLY SLACKEN. WITH H85 TEMPS TOPPING OUT IN THE 8-10C RANGE...MIXING TO H75 ON GFS/NAM FCST SDNGS YIELD HI TEMPS IN THE 75-80 RANGE WITH DOWNSLOPING FLOW AWAY FM LK MODERATION IN LLVL WNW FLOW. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 427 PM EDT WED MAY 23 2012 MAIN CONCERN FOR THE LONG TERM PERIOD IS THE SEVERE WEATHER POTENTIAL AT THE BEGINNING OF THE PERIOD. STATIONARY FRONT WILL BE SETUP OVER WRN LK SUPERIOR...WHILE A FAIRLY POTENT SHORTWAVE PUSHING NE ACROSS AT LEAST THE WRN HALF OF THE CWA THURS NIGHT. THIS WILL LEAD TO ONGOING CYCLOGENESIS OVER NW WI DURING THE LATE AFTERNOON AND THE LOW MOVING NNE ACROSS WRN LK SUPERIOR DURING THE EVENING. EXPECT THUNDERSTORMS TO BE ONGOING OVER NW WI AND FAR WRN LK SUPERIOR AT THE START OF THE PERIOD AND THEN MOVE E AND NE AS THE COLD FRONT PUSHES THROUGH THE CWA DURING THE NIGHT. WITH THE STRONG WINDS ALOFT AND THE CYCLOGENESIS...FEEL THAT THERE IS A DECENT CHANCE OF SEVERE WEATHER OVER THE WRN HALF OF THE CWA TOMORROW EVENING. THERE IS A VERY THIN CORRIDOR OF MLCAPE VALUES APPROACHING 500-1000 J/KG OVER THE WRN THIRD OF THE CWA AND INSTABILITY MAY BE THE MAIN LIMITING FACTOR AS STORMS MOVE INTO THE CWA. CAPE FAIRLY SKINNY...NCAPE VALUES AROUND 0.1...SO DON/T EXPECT MUCH MORE THAN MARGINALLY SEVERE HAIL. WIND APPEARS TO BE BIGGEST THREAT WITH THE STORMS. INVERTED V LOOK TO THE SOUNDINGS OVER THE WEST AND DCAPE VALUES OF 600-800 J/KG. STRONG WINDS ALOFT...APPROACHING 70-80KTS AT H700 AND 40-50KTS JUST A COUPLE HUNDRED FEET ABOVE THE SFC...WILL BE AIDED BY A POCKET OF DRY H700-500 AIR AND STEEPER LAPSE RATES. THIS...COMBINED WITH STORM MOTION TO THE NNE AT 65-70KTS ALL POINT TO THE POTENTIAL FOR DAMAGING WINDS WHERE THUNDERSTORMS...AND POTENTIALLY EVEN SHOWERS OCCUR. WITH THE LOW DEVELOPING ALONG THE FRONT POTENTIALLY AFFECTING THE LLVL WIND FIELD...COULD SEE SOME LLVL BACKING OF THE WINDS AND PRODUCE SOME ROTATING UPDRAFTS AND SUPERCELLS...ESPECIALLY OVER NW WI. BUT THE EXPECTED DRY LLVL AIR HELPING PRODUCE AN INVERTED V AND LCL HEIGHTS TOWARDS 3-3.5KFT SHOULD LIMIT TORNADO POTENTIAL THIS FAR N. CURRENT THOUGHT IS BEST CHANCES FOR SEVERE SHOULD BE FROM BARAGA/IRON COUNTIES AND WEST...BUT WITH THE STORM MOTIONS...COULD POTENTIALLY AFFECT MARQUETTE/DICKINSON/MENOMINEE COUNTIES BEFORE HEADING OVER LK SUPERIOR. ADDED DAMAGING WIND THREAT TO THE GRIDS AND MENTIONED IN THE HWO. THIS MATCHES UP WELL WHERE SPC HAS A SLIGHT RISK...WITH HATCHED AREA JUST TO THE SW OF THE CWA. AS THE LOW QUICKLY LIFTS NE...EXPECT BEST FORCING TO QUICKLY DEPART OVERNIGHT AND PULL FORCING WITH IT. IN ADDITION...AS THE COLD FRONT PUSHES EAST INTO THE CNTRL/ERN CWA...THE CAPPING BECOMES STRONGER. WITH THE COMBINATION OF LOOSING FORCING AND MORE UNFAVORABLE ENVIRONMENT...EXPECT THE SHOWERS/THUNDERSTORMS TO DIMINISH AS THEY MOVE INTO THE CNTRL/ERN CWA. 09Z SREF ALSO SHOWING THIS DIMINISHING TREND IN THE 3HR CALIBRATED THUNDERSTORM PROBS...AS THE SHOWERS/THUNDERSTORMS PUSH TO THE NE OVER LK SUPERIOR DURING THE OVERNIGHT HOURS. EXPECT GUSTY SE WINDS IN THE EVENING AHEAD OF THE LOW AND OVER THE KEWEENAW OVERNIGHT BEHIND THE LOW/FRONT. BUMPED UP WINDS SIGNIFICANTLY OVER THE KEWEENAW BEHIND THE LOW AND FRONT...WITH THE STRONG WINDS JUST ABOVE THE SFC /NAM SHOWING 60KTS AT 1.5KFT/. IN ADDITION...GOOD ISALLOBARIC COMPONENT TO THE WINDS OVER THE WEST OVERNIGHT WITH THE INTENSIFYING LOW PUSHING NE. ONLY CONCERN FOR GOING MORE THAN 30-35KTS AT THIS POINT IS AFFECT OF COOLER WATER TEMPS...BUT THAT MAY NOT HAVE MUCH EFFECT OVER THE HIGHER TERRAIN. FRI...GUSTY WRLY WINDS...30-35KTS...IN THE MORNING BEHIND THE LOW. DRIER AIR MOVING IN AND H700 CAP SHOULD LIMIT DEVELOPMENT EVEN WITH WEAK MID-LVL WAVE MOVING THROUGH. DEEP MOISTURE IS LIMITED AND ML/MU CAPE VALUES ARE BELOW 100 JKG WOULD LEAD TO LITTLE/NO PCPN CHANCES. LATEST NAM RUN HAS BACKED OFF ON PCPN AND WILL FOLLOW SUIT WITH REMOVING SLIGHT CHANCES. WILL KEEP SKIES PARTLY/MOSTLY CLOUDY DURING THE AFTN WITH EXPECTED DIURNAL CU DEVELOPMENT. MIXING TO H750 WOULD YIELD HIGHS IN THE 70S...WITH THE HIGHEST VALUES IN THE FAVORED DOWNSLOPE AREAS OF THE CNTRL. WITH THE GUSTY WINDS AND DEEPER MIXING INTO THE LIMITED MOISTURE ALOFT...EXPECT RH VALUES TO FALL TO 30 PERCENT. FIRE WX CONCERNS MAINLY OVER THE CNTRL...WHERE LESS RAIN IS EXPECTED ON THURS NIGHT. FRI NIGHT...WEAK HIGH PRESSURE RIDGE FROM HIGH JUST N OF MN. SFC LOW DEVELOPING IN THE CNTRL PLAINS IN RESPONSE TO DEEP UPPER TROUGH OVER THE WRN CONUS WILL BEGIN TO PUSH A WARM FRONT N TOWARDS THE UPPER GREAT LAKES LATE FRI NIGHT. COULD PRODUCE A FEW SHOWERS TOWARDS THE WI BORDER LATE. CWA WILL BE ON THE E SIDE OF THE UPPER RIDGE AXIS STRETCHING FROM THE OHIO VALLEY TO LK WINNIPEG UNTIL SUN NIGHT. STILL SEVERAL WEAK DISTURBANCES PUSHING THROUGH THE FLOW SAT AFTN THROUGH SUN NIGHT. THE WARM FRONT WILL CONTINUE TO SLOWLY PUSH NE ON SAT...AS IT BATTLES THE HIGH THAT WILL HAVE MOVED EAST OVER ONTARIO. PCPN CHANCES ON SAT WILL LARGELY DEPEND ON HOW FAR N THE FRONT WILL PUSH. BEST CHANCES LOOK TO BE ON SAT NIGHT INTO SUN...AS THE FRONT MOVES INTO NRN WI AND FINALLY INTO UPPER MI BY SUN AFTN. THIS WILL PUT THE BEST WAA FOCUS OVER THE CWA. THERE ARE DECENT MID LEVEL LAPSE RATES...BUT ELEVATED CAPES ARE NOT TOO IMPRESSIVE...SO HAVE CAPPED THUNDER TO CHANCES FOR SAT NIGHT INTO SUN. WITH THE CONVECTION LIKELY TO BE ELEVATED...THE MAIN THREAT WOULD BE SMALL HAIL AND HEAVY RAIN. CWA WILL BE UNDER THE WARM SECTOR LATE SUN AFTN AND INTO SUN NIGHT...WITH MODELS DIVERGING WITH THE HANDLING OF THE LOW HEADING INTO THE FIRST PART OF NEXT WEEK. 12Z GFS SHOWS THE LOW CONTINUING NNE INTO SRN CANADA ON SUN NIGHT AND MONDAY WHILE PUSHING COLD FRONT ACROSS UPPER MI ON MON. 00Z ECMWF ON THE OTHERHAND DISSIPATES THE LOW OVER THE CWA AND THEN SLOWLY SLIDES IT EAST THROUGH TUES. AFTER A MORE ACTIVE PERIOD...OVERALL TREND LOOKS TO BE TOWARDS A SLIGHTLY DRIER/QUIET WEATHER TOWARDS THE MIDDLE OF NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 132 AM EDT THU MAY 24 2012 STRONG WINDS AND LLWS REMAIN A CONCERN THROUGHOUT THE FORECAST. LATEST VAD WIND PROFILE PRODUCT FROM THE MARQUETTE 88D SHOWS 50KT S WINDS AT 2-3K FEET EARLY THIS MORNING WHICH IS IN LINE WITH LATEST BUFKIT FORECASTS. UNIDIRECTIONAL FLOW AS STRONG AS 55 TO 60KTS ABOVE THE BOUNDARY LAYER WILL GRADUALLY DIMINISH THROUGH THE NIGHT AS IT SHIFTS SLIGHTLY TO THE SW BUT WILL REMAIN 40-48 KTS BY 12Z. DECENT MIXING WILL RESULT IN VERY GUSTY CONDITIONS AT ALL THREE TAF SITES AHEAD OF SLOWLY APPROACHING COLD FRONT. HAVE BUMPED WIND GUST SPEEDS UP A BIT FOR THE DAYTIME HOURS. WIDELY SCATTERED SHOWERS TO CONTINUE AT IWD THROUGHOUT THE NIGHT WITH A CHANCE OF THUNDERSTORMS THERE BY DAYBREAK. CONVECTIVE ACTIVITY TO INCREASE THROUGH THE DAYLIGHT HOURS AS IT SPREADS SLOWLY ACROSS THE REGION...REACHING CMX BY 18Z AND SAW AROUND 0Z FRIDAY. STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE ALONG THE COLD FRONT DURING THE AFTERNOON AND EVENING WITH CONVECTION LASTING THROUGH THE END OF THE TAF FORECAST PERIOD. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 427 PM EDT WED MAY 23 2012 LOW PRESSURE OVER S MANITOBA WILL PUSH INTO ONTARIO TONIGHT AND THURSDAY...AS AN ADDITIONAL LOW MOVES FROM THE CENTRAL PLAINS TO W LS FRIDAY AFTERNOON. EXPECT THE LOW TO CONTINUE A NE TRACK ACROSS ONTARIO THROUGH FRIDAY...WITH A TROUGH LINGERING ACROSS LAKE SUPERIOR. STRENGTHENING S WINDS WILL PREVAIL AHEAD OF THIS SYSTEM TONIGHT THROUGH THURSDAY. WITH A STABLE TEMPERATURE PROFILE THE STRONGEST WINDS...EXPECT THE STRONGEST ACROSS THE TALLER OBSERVING PLATFORMS ACROSS CENTRAL LAKE SUPERIOR. HIGH PRESSURE OVER CENTRAL CANADA FRIDAY NIGHT WILL SLIDE ACROSS ONTARIO SATURDAY...BEFORE SETTLING ACROSS HUDSON BAY ON SUNDAY. AS A RESULT...A RIDGE WILL SLIDE ACROSS LS SATURDAY...WITH LIGHTER WINDS TAKING HOLD. A LOW ACROSS THE CENTRAL PLAINS WILL FILL ACROSS MN SUNDAY INTO SUNDAY NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WIND ADVISORY FROM 1 PM EDT /NOON CDT/ THIS AFTERNOON TO 8 PM EDT /7 PM CDT/ THIS EVENING FOR MIZ002-004-005-009>011-084. LAKE SUPERIOR... GALE WATCH FROM LATE TONIGHT THROUGH FRIDAY MORNING FOR LSZ263- 264-266. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...KC SHORT TERM...KC LONG TERM...SRF AVIATION...RJT MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
133 AM EDT THU MAY 24 2012 .SYNOPSIS... ISSUED AT 427 PM EDT WED MAY 23 2012 WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH OVER THE NW CONUS AND A RIDGE FROM THE CNTRL GREAT LAKES INTO NRN ONTARIO RESULTING IN SW FLOW FROM THE CNTRL PLAINS TO THE UPPER MS VALLEY AND LAKE SUPERIOR. AT THE SFC...SRLY WINDS WERE INCREASING ACROSS THE REGION AHEAD A COLD FRONT EXTENDING THROUGH THE ERN DAKOTAS FROM LOW PRESSURE OVER SRN MANITOBA. AN AREA OF TSRA WAS MOVING NE THROUGH N CNTRL MN SUPPORTED A SHRTWV NEAR THE NOSE OS STRONG 925-850 MB THETA-E ADVECTION. OVER UPPER MI...VIS LOOP AND SFC OBS SHOWED CONSIDERABLE HIGH CLOUDS IN THE BROAD WAA PATTERN AHEAD OF THE FRONT. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 427 PM EDT WED MAY 23 2012 TONIGHT...AS A SHRTWV OVER NW MN LIFTS TO THE NE AND THE NEXT SIGNIFICANT UPSTREAM SHRTWV OVER NEVADA ROTATES THROUGH THE WRN TROF...ANOTHER SFC LOW WILL DEVELOP IN THE PLAINS AND MOVE NNEWD ON COLD FNT ATTENDANT TO FIRST SFC LO DRIFTING THRU NW ONTARIO. EXPECT THAT THE GREATEST CHANCE FOR SHRA/TSRA WILL REMAIN CLOSER TO THE FRONT AND NEAR THE AXIS OF GREATER MOISTURE/INSTABILITY OVER MN AND FAVORABLE UPPER LEVEL DIV WITH THE RIGHT ENTRANCE OF THE JET OVER NW ONTARIO. SO...THE NAM/REGIONAL GEM/ECMWF WERE PREFERRED WITH THE SHRA/TSRA PLACEMENT COMPARED TO THE GFS WHICH SEEMED OVERLY AGGRESSIVE IN PUSHING THE PCPN TO THE EAST. THURSDAY...THE MAIN SHRTWV LIFTS OUT OF THE PLAINS TO THE UPPER MS VALLEY SUPPORTING A CONSOLIDATED SFC LOW TO NEAR KDLH BY 00Z/FRI. GIVEN THE STRENGTHENING DYNAMICS AGAIN TO THE WEST...CONTINUED TO DELAY THE EASTWARD PROGRESSION OF THE SHRA/TSRA INTO UPPER MI TIL MAINLY LATE IN THE DAY. MLCAPE VALUES TO AROUND 1K J/KG WITH AFTERNOON HEATING AND SFC DEWPOINTS NEAR 60 WILL SUPPORT TSRA CHANCES FROM IWD-CMX...MAINLY AFT 21Z. WITH INVERTED V LOOK TO THE SOUNDINGS AND VERY STRONG MAINLY UNIDIRECTIONAL WIND FIELD (700 MB WINDS TO NEAR 70KT)...EXPECT THAT DAMAGING WINDS WILL BE THE MAIN HAZARD WITH ANY TSRA. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 427 PM EDT WED MAY 23 2012 MAIN CONCERN FOR THE LONG TERM PERIOD IS THE SEVERE WEATHER POTENTIAL AT THE BEGINNING OF THE PERIOD. STATIONARY FRONT WILL BE SETUP OVER WRN LK SUPERIOR...WHILE A FAIRLY POTENT SHORTWAVE PUSHING NE ACROSS AT LEAST THE WRN HALF OF THE CWA THURS NIGHT. THIS WILL LEAD TO ONGOING CYCLOGENESIS OVER NW WI DURING THE LATE AFTERNOON AND THE LOW MOVING NNE ACROSS WRN LK SUPERIOR DURING THE EVENING. EXPECT THUNDERSTORMS TO BE ONGOING OVER NW WI AND FAR WRN LK SUPERIOR AT THE START OF THE PERIOD AND THEN MOVE E AND NE AS THE COLD FRONT PUSHES THROUGH THE CWA DURING THE NIGHT. WITH THE STRONG WINDS ALOFT AND THE CYCLOGENESIS...FEEL THAT THERE IS A DECENT CHANCE OF SEVERE WEATHER OVER THE WRN HALF OF THE CWA TOMORROW EVENING. THERE IS A VERY THIN CORRIDOR OF MLCAPE VALUES APPROACHING 500-1000 J/KG OVER THE WRN THIRD OF THE CWA AND INSTABILITY MAY BE THE MAIN LIMITING FACTOR AS STORMS MOVE INTO THE CWA. CAPE FAIRLY SKINNY...NCAPE VALUES AROUND 0.1...SO DON/T EXPECT MUCH MORE THAN MARGINALLY SEVERE HAIL. WIND APPEARS TO BE BIGGEST THREAT WITH THE STORMS. INVERTED V LOOK TO THE SOUNDINGS OVER THE WEST AND DCAPE VALUES OF 600-800 J/KG. STRONG WINDS ALOFT...APPROACHING 70-80KTS AT H700 AND 40-50KTS JUST A COUPLE HUNDRED FEET ABOVE THE SFC...WILL BE AIDED BY A POCKET OF DRY H700-500 AIR AND STEEPER LAPSE RATES. THIS...COMBINED WITH STORM MOTION TO THE NNE AT 65-70KTS ALL POINT TO THE POTENTIAL FOR DAMAGING WINDS WHERE THUNDERSTORMS...AND POTENTIALLY EVEN SHOWERS OCCUR. WITH THE LOW DEVELOPING ALONG THE FRONT POTENTIALLY AFFECTING THE LLVL WIND FIELD...COULD SEE SOME LLVL BACKING OF THE WINDS AND PRODUCE SOME ROTATING UPDRAFTS AND SUPERCELLS...ESPECIALLY OVER NW WI. BUT THE EXPECTED DRY LLVL AIR HELPING PRODUCE AN INVERTED V AND LCL HEIGHTS TOWARDS 3-3.5KFT SHOULD LIMIT TORNADO POTENTIAL THIS FAR N. CURRENT THOUGHT IS BEST CHANCES FOR SEVERE SHOULD BE FROM BARAGA/IRON COUNTIES AND WEST...BUT WITH THE STORM MOTIONS...COULD POTENTIALLY AFFECT MARQUETTE/DICKINSON/MENOMINEE COUNTIES BEFORE HEADING OVER LK SUPERIOR. ADDED DAMAGING WIND THREAT TO THE GRIDS AND MENTIONED IN THE HWO. THIS MATCHES UP WELL WHERE SPC HAS A SLIGHT RISK...WITH HATCHED AREA JUST TO THE SW OF THE CWA. AS THE LOW QUICKLY LIFTS NE...EXPECT BEST FORCING TO QUICKLY DEPART OVERNIGHT AND PULL FORCING WITH IT. IN ADDITION...AS THE COLD FRONT PUSHES EAST INTO THE CNTRL/ERN CWA...THE CAPPING BECOMES STRONGER. WITH THE COMBINATION OF LOOSING FORCING AND MORE UNFAVORABLE ENVIRONMENT...EXPECT THE SHOWERS/THUNDERSTORMS TO DIMINISH AS THEY MOVE INTO THE CNTRL/ERN CWA. 09Z SREF ALSO SHOWING THIS DIMINISHING TREND IN THE 3HR CALIBRATED THUNDERSTORM PROBS...AS THE SHOWERS/THUNDERSTORMS PUSH TO THE NE OVER LK SUPERIOR DURING THE OVERNIGHT HOURS. EXPECT GUSTY SE WINDS IN THE EVENING AHEAD OF THE LOW AND OVER THE KEWEENAW OVERNIGHT BEHIND THE LOW/FRONT. BUMPED UP WINDS SIGNIFICANTLY OVER THE KEWEENAW BEHIND THE LOW AND FRONT...WITH THE STRONG WINDS JUST ABOVE THE SFC /NAM SHOWING 60KTS AT 1.5KFT/. IN ADDITION...GOOD ISALLOBARIC COMPONENT TO THE WINDS OVER THE WEST OVERNIGHT WITH THE INTENSIFYING LOW PUSHING NE. ONLY CONCERN FOR GOING MORE THAN 30-35KTS AT THIS POINT IS AFFECT OF COOLER WATER TEMPS...BUT THAT MAY NOT HAVE MUCH EFFECT OVER THE HIGHER TERRAIN. FRI...GUSTY WRLY WINDS...30-35KTS...IN THE MORNING BEHIND THE LOW. DRIER AIR MOVING IN AND H700 CAP SHOULD LIMIT DEVELOPMENT EVEN WITH WEAK MID-LVL WAVE MOVING THROUGH. DEEP MOISTURE IS LIMITED AND ML/MU CAPE VALUES ARE BELOW 100 JKG WOULD LEAD TO LITTLE/NO PCPN CHANCES. LATEST NAM RUN HAS BACKED OFF ON PCPN AND WILL FOLLOW SUIT WITH REMOVING SLIGHT CHANCES. WILL KEEP SKIES PARTLY/MOSTLY CLOUDY DURING THE AFTN WITH EXPECTED DIURNAL CU DEVELOPMENT. MIXING TO H750 WOULD YIELD HIGHS IN THE 70S...WITH THE HIGHEST VALUES IN THE FAVORED DOWNSLOPE AREAS OF THE CNTRL. WITH THE GUSTY WINDS AND DEEPER MIXING INTO THE LIMITED MOISTURE ALOFT...EXPECT RH VALUES TO FALL TO 30 PERCENT. FIRE WX CONCERNS MAINLY OVER THE CNTRL...WHERE LESS RAIN IS EXPECTED ON THURS NIGHT. FRI NIGHT...WEAK HIGH PRESSURE RIDGE FROM HIGH JUST N OF MN. SFC LOW DEVELOPING IN THE CNTRL PLAINS IN RESPONSE TO DEEP UPPER TROUGH OVER THE WRN CONUS WILL BEGIN TO PUSH A WARM FRONT N TOWARDS THE UPPER GREAT LAKES LATE FRI NIGHT. COULD PRODUCE A FEW SHOWERS TOWARDS THE WI BORDER LATE. CWA WILL BE ON THE E SIDE OF THE UPPER RIDGE AXIS STRETCHING FROM THE OHIO VALLEY TO LK WINNIPEG UNTIL SUN NIGHT. STILL SEVERAL WEAK DISTURBANCES PUSHING THROUGH THE FLOW SAT AFTN THROUGH SUN NIGHT. THE WARM FRONT WILL CONTINUE TO SLOWLY PUSH NE ON SAT...AS IT BATTLES THE HIGH THAT WILL HAVE MOVED EAST OVER ONTARIO. PCPN CHANCES ON SAT WILL LARGELY DEPEND ON HOW FAR N THE FRONT WILL PUSH. BEST CHANCES LOOK TO BE ON SAT NIGHT INTO SUN...AS THE FRONT MOVES INTO NRN WI AND FINALLY INTO UPPER MI BY SUN AFTN. THIS WILL PUT THE BEST WAA FOCUS OVER THE CWA. THERE ARE DECENT MID LEVEL LAPSE RATES...BUT ELEVATED CAPES ARE NOT TOO IMPRESSIVE...SO HAVE CAPPED THUNDER TO CHANCES FOR SAT NIGHT INTO SUN. WITH THE CONVECTION LIKELY TO BE ELEVATED...THE MAIN THREAT WOULD BE SMALL HAIL AND HEAVY RAIN. CWA WILL BE UNDER THE WARM SECTOR LATE SUN AFTN AND INTO SUN NIGHT...WITH MODELS DIVERGING WITH THE HANDLING OF THE LOW HEADING INTO THE FIRST PART OF NEXT WEEK. 12Z GFS SHOWS THE LOW CONTINUING NNE INTO SRN CANADA ON SUN NIGHT AND MONDAY WHILE PUSHING COLD FRONT ACROSS UPPER MI ON MON. 00Z ECMWF ON THE OTHERHAND DISSIPATES THE LOW OVER THE CWA AND THEN SLOWLY SLIDES IT EAST THROUGH TUES. AFTER A MORE ACTIVE PERIOD...OVERALL TREND LOOKS TO BE TOWARDS A SLIGHTLY DRIER/QUIET WEATHER TOWARDS THE MIDDLE OF NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 132 AM EDT THU MAY 24 2012 STRONG WINDS AND LLWS REMAIN A CONCERN THROUGHOUT THE FORECAST. LATEST VAD WIND PROFILE PRODUCT FROM THE MARQUETTE 88D SHOWS 50KT S WINDS AT 2-3K FEET EARLY THIS MORNING WHICH IS IN LINE WITH LATEST BUFKIT FORECASTS. UNIDIRECTIONAL FLOW AS STRONG AS 55 TO 60KTS ABOVE THE BOUNDARY LAYER WILL GRADUALLY DIMINISH THROUGH THE NIGHT AS IT SHIFTS SLIGHTLY TO THE SW BUT WILL REMAIN 40-48 KTS BY 12Z. DECENT MIXING WILL RESULT IN VERY GUSTY CONDITIONS AT ALL THREE TAF SITES AHEAD OF SLOWLY APPROACHING COLD FRONT. HAVE BUMPED WIND GUST SPEEDS UP A BIT FOR THE DAYTIME HOURS. WIDELY SCATTERED SHOWERS TO CONTINUE AT IWD THROUGHOUT THE NIGHT WITH A CHANCE OF THUNDERSTORMS THERE BY DAYBREAK. CONVECTIVE ACTIVITY TO INCREASE THROUGH THE DAYLIGHT HOURS AS IT SPREADS SLOWLY ACROSS THE REGION...REACHING CMX BY 18Z AND SAW AROUND 0Z FRIDAY. STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE ALONG THE COLD FRONT DURING THE AFTERNOON AND EVENING WITH CONVECTION LASTING THROUGH THE END OF THE TAF FORECAST PERIOD. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 427 PM EDT WED MAY 23 2012 LOW PRESSURE OVER S MANITOBA WILL PUSH INTO ONTARIO TONIGHT AND THURSDAY...AS AN ADDITIONAL LOW MOVES FROM THE CENTRAL PLAINS TO W LS FRIDAY AFTERNOON. EXPECT THE LOW TO CONTINUE A NE TRACK ACROSS ONTARIO THROUGH FRIDAY...WITH A TROUGH LINGERING ACROSS LAKE SUPERIOR. STRENGTHENING S WINDS WILL PREVAIL AHEAD OF THIS SYSTEM TONIGHT THROUGH THURSDAY. WITH A STABLE TEMPERATURE PROFILE THE STRONGEST WINDS...EXPECT THE STRONGEST ACROSS THE TALLER OBSERVING PLATFORMS ACROSS CENTRAL LAKE SUPERIOR. HIGH PRESSURE OVER CENTRAL CANADA FRIDAY NIGHT WILL SLIDE ACROSS ONTARIO SATURDAY...BEFORE SETTLING ACROSS HUDSON BAY ON SUNDAY. AS A RESULT...A RIDGE WILL SLIDE ACROSS LS SATURDAY...WITH LIGHTER WINDS TAKING HOLD. A LOW ACROSS THE CENTRAL PLAINS WILL FILL ACROSS MN SUNDAY INTO SUNDAY NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...JLB SHORT TERM...JLB LONG TERM...SRF AVIATION...RJT MARINE...JLB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1246 AM CDT THU MAY 24 2012 .AVIATION UPDATE...LINE OF CONVECTION TO THE WEST OF KGRI AS EXTENDED SOUTHEAST AND INTENSIFIED...WITH WIND GUSTS NEAR OR ABOVE 50KTS NOW POSSIBLE AT KGRI THROUGH THE NEXT HOUR. && .PREV DISCUSSION... /ISSUED 1226 AM CDT THU MAY 24 2012/ AVIATION...06Z KGRI TAF. PREVAILING VFR CONDITIONS TO CONTINUE...WITH TEMPORARY MVFR CONDITIONS POSSIBLE 07Z-11Z. CONVECTIVE ACTIVITY WEST OF KGRI MAY WORK IN LATER TONIGHT...BUT PROBABLY NOT UNTIL AFTER 07Z. SURFACE WINDS TO REMAIN FROM THE NORTH FOR THE MOST PART. MINIMAL VISIBILITY RESTRICTIONS WILL BE POSSIBLE IN PRECIPITATION...BUT WILL OTHERWISE REMAIN UNRESTRICTED DURING THE TAF PERIOD. PREV DISCUSSION... /ISSUED 1104 PM CDT WED MAY 23 2012/ UPDATE...KUEX INDICATES CONVECTION SPREADING IN AERIAL COVERAGE ACROSS THE NORTHWESTERN ONE-THIRD OF THE CWA. SHORT TERM GUIDANCE CONTINUES TO SUGGEST THIS A TREND WHICH WILL CONTINUE. DEEP LAYER MUCAPE VALUES NEAR 1000J/KG AND DEEP LAYER BULK SHEAR NEAR 50KTS WILL CONTINUE TO PROMOTE A THREAT OF LARGE HAIL. A NEW SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED WHICH COVERS THE ENTIRE CWA THROUGH 10Z. FORECAST HAS BEEN UPDATED TO INCLUDE THIS NEW SEVERE THUNDERSTORM WATCH. PREV DISCUSSION... /ISSUED 949 PM CDT WED MAY 23 2012/ UPDATE...EVENING UPPER AIR ANALYSIS INDICATES TROUGHING OVER THE WESTERN CONUS WITH A RIDGE OVER THE EAST. MID AND UPPER LEVEL JET ENERGY EXTENDS FROM THE WEST-CENTRAL CONUS...SOUTHEAST INTO THE MID ROCKY MOUNTAIN RANGE AND THEN NORTHEAST ACROSS THE CENTRAL PLAINS. A ~100KT UPPER LEVEL JET STREAK AND A ~70KT MID LEVEL JET STREAK IS NOTED ACROSS THE WEST-CENTRAL CONUS AND BEGINNING TO PUSH INTO THE CENTRAL PLAINS. WATER VAPOR IMAGERY SHOWS A MID LEVEL SHORT WAVE APPROACHING THE MID ROCKY MOUNTAIN RANGE. AT THE SURFACE A COLD FRONT EXTENDS FROM NEAR KOMA...TO NEAR KCNK...TO NEAR KDDC. LOW LEVEL FLOW IS FROM THE THE NORTHEAST ACROSS MUCH OF OUR CWA AS A RESULT...ALTHOUGH LOCATIONS FROM THAYER COUNTY TO MITCHELL COUNTY...STILL AHEAD OF THE LOW LEVEL BAROCLINIC ZONE...REMAIN FROM THE SOUTHEAST. KUEX SHOWS A THIN LINE OF CONVECTION...ALONG THE LOW LEVEL BAROCLINIC ZONE...EXTENDING FROM THAYER COUNTY TO MITCHELL COUNTY...BUT ADDITIONAL CONVECTION IS NOT FIRING FARTHER NORTHWEST ACROSS MUCH OF THE REST OF THE CWA. SHORT TERM GUIDANCE SUGGESTS SURFACE-BASED CONVECTION WILL REMAIN POSSIBLE ALONG THE LOW LEVEL BAROCLINIC ZONE THROUGH 04Z OR SO...HOWEVER THIS ACTIVITY SHOULD DIMINISH THEREAFTER AS DIABATIC HEATING IS COMPLETELY LOST AND REMNANT FORCING ALONG THE BAROCLINIC ZONE REMAINS FAIRLY WEAK. THE INDIRECT THERMAL CIRCULATION WITHIN THE LEFT-FRONT QUAD OF THE APPROACHING MID LEVEL JET STREAK...ALONG WITH CONTINUALLY INCREASING OMEGA AHEAD OF THE MID LEVEL SHORT WAVE...WILL CONTINUE TO PROMOTE PRECIPITATION ACROSS MUCH OF THE CWA THROUGH THE OVERNIGHT HOURS. AT THIS TIME IT APPEARS THE BULK OF THE FORCING OVERNIGHT WILL BE RELEGATED TO THE NORTHERN HALF OF THE CWA WHICH IS WHERE MOST OF THE PRECIPITATION WILL BE REALIZED. SPC MESO-ANALYSIS INDICATES DEEP LAYER MUCAPE VALUES OF AROUND 1000J/KG CURRENTLY IN EXISTENCE ACROSS MUCH OF THE CWA...WITH DEEP LAYER SHEAR OF AROUND 60KTS. THE COMBINATION OF MODERATE INSTABILITY AND VERY STRONG DEEP LAYER SHEAR WILL CONTINUE TO PROMOTE A THREAT OF LARGE HAIL ACROSS MUCH OF THE CWA THROUGH EARLY MORNING THURSDAY. WENT AHEAD AND UPDATED THE FORECAST WITH SLIGHT CHANGES MADE TO HOURLY GIRDS TO BETTER REFLECT CURRENT TRENDS...ESPECIALLY REGARDING CLOUD COVER. CURRENT POPS ACROSS NORTHERN PORTIONS OF THE CWA LOOK RIGHT ON FOR TONIGHT AND THUS RAIN CHANCES WERE LEFT AS IS. PREV DISCUSSION... /ISSUED 419 PM CDT WED MAY 23 2012/ UPDATE...SENT AN UPDATE TO THE FORECAST TO INCLUDE SEVERE THUNDERSTORM WATCH 293 FOR PORTIONS OF THE FORECAST AREA THROUGH 11 PM CDT. THE GREATEST POTENTIAL FOR ANY SEVERE STORMS WILL REMAIN WITH AND ALONG EITHER SIDE OF A SLOWLY PROGRESSING COLD FRONT...WITH LARGE HAIL AND DAMAGING WIND GUSTS BEING THE PRIMARY CONCERNS WITH ANY STORMS THAT DO DEVELOP. PREV DISCUSSION... /ISSUED 400 PM CDT WED MAY 23 2012/ SHORT TERM...A FAIRLY ACTIVE START TO THE FORECAST IS EXPECTED THIS EVENING AS A COLD FRONT SLOWLY MAKES ITS WAY ACROSS SOUTH CENTRAL NEBRASKA AND NORTH CENTRAL KANSAS...WITH AN ASSOCIATED MID LEVEL LOW PRESSURE SYSTEM TO THE WEST EXPECTED TO HELP BRING SOME WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY ACROSS MUCH OF THE FORECAST AREA DURING THE OVERNIGHT HOURS TONIGHT. SHORT TERM MODELS ARE IN MODERATE DISAGREEMENT WITH INITIATION OF CONVECTION ALONG A PASSING COLD FRONT...CURRENTLY DRAPED FROM NEAR NORFOLK...ACROSS GRAND ISLAND...SOUTH WESTWARD TOWARDS HOLDREGE. THIS FRONT HAS BEEN VERY SLOW TO WORK ITS WAY ACROSS THE FORECAST AREA THIS AFTERNOON...AND SO FAR HAS YET TO PRODUCE ENOUGH FORCING TO BREAK LOW LEVEL CAP. 12Z NAM AND WRF BOTH DID TRY AND INITIATE CONVECTION...BUT 18Z NAM AND LATEST HRRR BOTH HOLD OFF ANY WIDESPREAD SHOWER OR THUNDERSTORM ACTIVITY TILL FORCING FROM MID LEVEL LOW TO OUR WEST APPROACHES CENTRAL NEBRASKA AROUND MIDNIGHT. THAT BEING SAID...INGREDIENTS ARE IN PLACE...AS LATEST MESO ANALYSIS SHOWS A FINGER OF 2000+ J/KG OF CAPE ACROSS THE LOCAL AREA NEAR THE SLOWLY PROGRESSING FRONT...AND LITTLE INHIBITION AS WELL AS DEVELOPING CU FIELD IN SATELLITE. PER CONSENSUS AMONG MODELS...DID BACK OFF ON INITIATION OF CONVECTION THIS AFTERNOON...BUT INSERTED MENTION OF SEVERE STORMS AFTER 00Z...AS COMBINATION OF SHEAR AND INSTABILITY SHOULD BE SUFFICIENT FOR SOME SUPERCELLS TO DEVELOP IF INITIATION CAN BE REALIZED NEAR THE FRONT. BEHIND THE FRONT...AS THE MID LEVEL SHORTWAVE APPROACHES THE REGION...BROADER SCALE FORCING SHOULD BE AMPLE ENOUGH TO DEVELOP WIDESPREAD CONVECTION ACROSS THE LOCAL AREA BY AROUND MIDNIGHT...CONTINUING INTO THE OVERNIGHT HOURS...SO THE POTENTIAL FOR SEVERE HAIL AND STRONG WINDS REMAIN A CONCERN. THEREAFTER...THE ATMOSPHERE SHOULD BEGIN TO STABILIZE BEHIND THE DEPARTING MID LEVEL WAVE...WITH A SMALL CHANCE FOR SHOWERS AND AN ISOLATED THUNDERSTORM CONTINUING INTO THE AFTERNOON HOURS WITH NEAR TO SLIGHTLY BELOW SEASONAL TEMPERATURES EXPECTED DURING THE AFTERNOON. LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY. MAIN FORECAST CONCERNS WILL BE CHANCES FOR THUNDERSTORMS THROUGH MOST OF THE PERIOD AND TEMPERATURES. ZONAL TO SOUTHWEST FLOW GIVES WAY TO NORTHWEST FLOW. THERE ARE SEVERAL WAVES THAT MOVE THROUGH THE AREA DURING THE PERIOD. THE FIRST WAVE MOVES INTO THE AREA THURSDAY NIGHT INTO FRIDAY. THERE WILL BE A CHANCE FOR SOME THUNDERSTORMS. ON FRIDAY A SURFACE LOW DEVELOPING IN KANSAS WILL LIFT A WARM FRONT NORTH INTO THE FORECAST AREA. WITH THE FRONT MOVING THROUGH AND THE ANOTHER UPPER WAVE MOVING INTO THE AREA THERE IS A BETTER CHANCE FOR THUNDERSTORMS. SOME OF THESE STORMS COULD BE STRONG TO SEVERE. SATURDAY AND SATURDAY NIGHT THERE ARE WEAK WAVES THAT MOVES THROUGH BUT LITTLE IN THE WAY TO GET THINGS STARTED SO ANY PRECIPITATION WILL BE SPOTTY. THE NEXT CHANCE FOR SOME THUNDERSTORMS WILL BE SUNDAY INTO SUNDAY NIGHT. ANOTHER STRONGER WAVE MOVES INTO THE AREA AND A COLD FRONT MOVES THROUGH THE AREA SUNDAY AFTERNOON AND EVENING. THUNDERSTORMS WILL DEVELOP ALONG THE FRONT AS IT MOVES THROUGH. SOME OF THESE COULD BE SEVERE. MONDAY AND MONDAY NIGHT THE UPPER WAVE MOVES TO THE EAST AND A SURFACE HIGH PRESSURE MOVES INTO THE AREA...KEEPING THINGS DRY. AGAIN TUESDAY INTO TUESDAY NIGHT THERE ARE A FEW WEAK UPPER LEVEL WAVES THAT MOVE INTO THE PLAINS. MODELS HAVE SOME FAIRLY SPOTTY PRECIPITATION AROUND THE AREA WITH THESE UPPER LEVEL WAVES. THE GFS HAS MORE PRECIPITATION AROUND THAN THE ECMWF DOES. TEMPERATURES WILL BE SOMEWHAT VARIABLE THROUGH THE WEEK. WITH CLOUDS AROUND ON FRIDAY THE TEMPERATURES WILL BE A BIT COOLER...WARMING AFTER THE WARM FRONT LIFTS TO THE NORTH FOR SATURDAY AND SUNDAY THEN COOLING AGAIN AS THE COOL FRONT MOVE THROUGH MONDAY AND TUESDAY AND COOLING MORE AFTER THE FRONT MOVES THROUGH TUESDAY. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ AVIATION UPDATE/AVIATION/1105 UPDATE/949 UPDATE...BRYANT 419 UPDATE/SHORT TERM...ROSSI LONG TERM...JCB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1226 AM CDT THU MAY 24 2012 .AVIATION...06Z KGRI TAF. PREVAILING VFR CONDITIONS TO CONTINUE...WITH TEMPORARY MVFR CONDITIONS POSSIBLE 07Z-11Z. CONVECTIVE ACTIVITY WEST OF KGRI MAY WORK IN LATER TONIGHT...BUT PROBABLY NOT UNTIL AFTER 07Z. SURFACE WINDS TO REMAIN FROM THE NORTH FOR THE MOST PART. MINIMAL VISIBILITY RESTRICTIONS WILL BE POSSIBLE IN PRECIPITATION...BUT WILL OTHERWISE REMAIN UNRESTRICTED DURING THE TAF PERIOD. && .PREV DISCUSSION... /ISSUED 1104 PM CDT WED MAY 23 2012/ UPDATE...KUEX INDICATES CONVECTION SPREADING IN AERIAL COVERAGE ACROSS THE NORTHWESTERN ONE-THIRD OF THE CWA. SHORT TERM GUIDANCE CONTINUES TO SUGGEST THIS A TREND WHICH WILL CONTINUE. DEEP LAYER MUCAPE VALUES NEAR 1000J/KG AND DEEP LAYER BULK SHEAR NEAR 50KTS WILL CONTINUE TO PROMOTE A THREAT OF LARGE HAIL. A NEW SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED WHICH COVERS THE ENTIRE CWA THROUGH 10Z. FORECAST HAS BEEN UPDATED TO INCLUDE THIS NEW SEVERE THUNDERSTORM WATCH. PREV DISCUSSION... /ISSUED 949 PM CDT WED MAY 23 2012/ UPDATE...EVENING UPPER AIR ANALYSIS INDICATES TROUGHING OVER THE WESTERN CONUS WITH A RIDGE OVER THE EAST. MID AND UPPER LEVEL JET ENERGY EXTENDS FROM THE WEST-CENTRAL CONUS...SOUTHEAST INTO THE MID ROCKY MOUNTAIN RANGE AND THEN NORTHEAST ACROSS THE CENTRAL PLAINS. A ~100KT UPPER LEVEL JET STREAK AND A ~70KT MID LEVEL JET STREAK IS NOTED ACROSS THE WEST-CENTRAL CONUS AND BEGINNING TO PUSH INTO THE CENTRAL PLAINS. WATER VAPOR IMAGERY SHOWS A MID LEVEL SHORT WAVE APPROACHING THE MID ROCKY MOUNTAIN RANGE. AT THE SURFACE A COLD FRONT EXTENDS FROM NEAR KOMA...TO NEAR KCNK...TO NEAR KDDC. LOW LEVEL FLOW IS FROM THE THE NORTHEAST ACROSS MUCH OF OUR CWA AS A RESULT...ALTHOUGH LOCATIONS FROM THAYER COUNTY TO MITCHELL COUNTY...STILL AHEAD OF THE LOW LEVEL BAROCLINIC ZONE...REMAIN FROM THE SOUTHEAST. KUEX SHOWS A THIN LINE OF CONVECTION...ALONG THE LOW LEVEL BAROCLINIC ZONE...EXTENDING FROM THAYER COUNTY TO MITCHELL COUNTY...BUT ADDITIONAL CONVECTION IS NOT FIRING FARTHER NORTHWEST ACROSS MUCH OF THE REST OF THE CWA. SHORT TERM GUIDANCE SUGGESTS SURFACE-BASED CONVECTION WILL REMAIN POSSIBLE ALONG THE LOW LEVEL BAROCLINIC ZONE THROUGH 04Z OR SO...HOWEVER THIS ACTIVITY SHOULD DIMINISH THEREAFTER AS DIABATIC HEATING IS COMPLETELY LOST AND REMNANT FORCING ALONG THE BAROCLINIC ZONE REMAINS FAIRLY WEAK. THE INDIRECT THERMAL CIRCULATION WITHIN THE LEFT-FRONT QUAD OF THE APPROACHING MID LEVEL JET STREAK...ALONG WITH CONTINUALLY INCREASING OMEGA AHEAD OF THE MID LEVEL SHORT WAVE...WILL CONTINUE TO PROMOTE PRECIPITATION ACROSS MUCH OF THE CWA THROUGH THE OVERNIGHT HOURS. AT THIS TIME IT APPEARS THE BULK OF THE FORCING OVERNIGHT WILL BE RELEGATED TO THE NORTHERN HALF OF THE CWA WHICH IS WHERE MOST OF THE PRECIPITATION WILL BE REALIZED. SPC MESO-ANALYSIS INDICATES DEEP LAYER MUCAPE VALUES OF AROUND 1000J/KG CURRENTLY IN EXISTENCE ACROSS MUCH OF THE CWA...WITH DEEP LAYER SHEAR OF AROUND 60KTS. THE COMBINATION OF MODERATE INSTABILITY AND VERY STRONG DEEP LAYER SHEAR WILL CONTINUE TO PROMOTE A THREAT OF LARGE HAIL ACROSS MUCH OF THE CWA THROUGH EARLY MORNING THURSDAY. WENT AHEAD AND UPDATED THE FORECAST WITH SLIGHT CHANGES MADE TO HOURLY GIRDS TO BETTER REFLECT CURRENT TRENDS...ESPECIALLY REGARDING CLOUD COVER. CURRENT POPS ACROSS NORTHERN PORTIONS OF THE CWA LOOK RIGHT ON FOR TONIGHT AND THUS RAIN CHANCES WERE LEFT AS IS. PREV DISCUSSION... /ISSUED 419 PM CDT WED MAY 23 2012/ UPDATE...SENT AN UPDATE TO THE FORECAST TO INCLUDE SEVERE THUNDERSTORM WATCH 293 FOR PORTIONS OF THE FORECAST AREA THROUGH 11 PM CDT. THE GREATEST POTENTIAL FOR ANY SEVERE STORMS WILL REMAIN WITH AND ALONG EITHER SIDE OF A SLOWLY PROGRESSING COLD FRONT...WITH LARGE HAIL AND DAMAGING WIND GUSTS BEING THE PRIMARY CONCERNS WITH ANY STORMS THAT DO DEVELOP. PREV DISCUSSION... /ISSUED 400 PM CDT WED MAY 23 2012/ SHORT TERM...A FAIRLY ACTIVE START TO THE FORECAST IS EXPECTED THIS EVENING AS A COLD FRONT SLOWLY MAKES ITS WAY ACROSS SOUTH CENTRAL NEBRASKA AND NORTH CENTRAL KANSAS...WITH AN ASSOCIATED MID LEVEL LOW PRESSURE SYSTEM TO THE WEST EXPECTED TO HELP BRING SOME WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY ACROSS MUCH OF THE FORECAST AREA DURING THE OVERNIGHT HOURS TONIGHT. SHORT TERM MODELS ARE IN MODERATE DISAGREEMENT WITH INITIATION OF CONVECTION ALONG A PASSING COLD FRONT...CURRENTLY DRAPED FROM NEAR NORFOLK...ACROSS GRAND ISLAND...SOUTH WESTWARD TOWARDS HOLDREGE. THIS FRONT HAS BEEN VERY SLOW TO WORK ITS WAY ACROSS THE FORECAST AREA THIS AFTERNOON...AND SO FAR HAS YET TO PRODUCE ENOUGH FORCING TO BREAK LOW LEVEL CAP. 12Z NAM AND WRF BOTH DID TRY AND INITIATE CONVECTION...BUT 18Z NAM AND LATEST HRRR BOTH HOLD OFF ANY WIDESPREAD SHOWER OR THUNDERSTORM ACTIVITY TILL FORCING FROM MID LEVEL LOW TO OUR WEST APPROACHES CENTRAL NEBRASKA AROUND MIDNIGHT. THAT BEING SAID...INGREDIENTS ARE IN PLACE...AS LATEST MESO ANALYSIS SHOWS A FINGER OF 2000+ J/KG OF CAPE ACROSS THE LOCAL AREA NEAR THE SLOWLY PROGRESSING FRONT...AND LITTLE INHIBITION AS WELL AS DEVELOPING CU FIELD IN SATELLITE. PER CONSENSUS AMONG MODELS...DID BACK OFF ON INITIATION OF CONVECTION THIS AFTERNOON...BUT INSERTED MENTION OF SEVERE STORMS AFTER 00Z...AS COMBINATION OF SHEAR AND INSTABILITY SHOULD BE SUFFICIENT FOR SOME SUPERCELLS TO DEVELOP IF INITIATION CAN BE REALIZED NEAR THE FRONT. BEHIND THE FRONT...AS THE MID LEVEL SHORTWAVE APPROACHES THE REGION...BROADER SCALE FORCING SHOULD BE AMPLE ENOUGH TO DEVELOP WIDESPREAD CONVECTION ACROSS THE LOCAL AREA BY AROUND MIDNIGHT...CONTINUING INTO THE OVERNIGHT HOURS...SO THE POTENTIAL FOR SEVERE HAIL AND STRONG WINDS REMAIN A CONCERN. THEREAFTER...THE ATMOSPHERE SHOULD BEGIN TO STABILIZE BEHIND THE DEPARTING MID LEVEL WAVE...WITH A SMALL CHANCE FOR SHOWERS AND AN ISOLATED THUNDERSTORM CONTINUING INTO THE AFTERNOON HOURS WITH NEAR TO SLIGHTLY BELOW SEASONAL TEMPERATURES EXPECTED DURING THE AFTERNOON. LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY. MAIN FORECAST CONCERNS WILL BE CHANCES FOR THUNDERSTORMS THROUGH MOST OF THE PERIOD AND TEMPERATURES. ZONAL TO SOUTHWEST FLOW GIVES WAY TO NORTHWEST FLOW. THERE ARE SEVERAL WAVES THAT MOVE THROUGH THE AREA DURING THE PERIOD. THE FIRST WAVE MOVES INTO THE AREA THURSDAY NIGHT INTO FRIDAY. THERE WILL BE A CHANCE FOR SOME THUNDERSTORMS. ON FRIDAY A SURFACE LOW DEVELOPING IN KANSAS WILL LIFT A WARM FRONT NORTH INTO THE FORECAST AREA. WITH THE FRONT MOVING THROUGH AND THE ANOTHER UPPER WAVE MOVING INTO THE AREA THERE IS A BETTER CHANCE FOR THUNDERSTORMS. SOME OF THESE STORMS COULD BE STRONG TO SEVERE. SATURDAY AND SATURDAY NIGHT THERE ARE WEAK WAVES THAT MOVES THROUGH BUT LITTLE IN THE WAY TO GET THINGS STARTED SO ANY PRECIPITATION WILL BE SPOTTY. THE NEXT CHANCE FOR SOME THUNDERSTORMS WILL BE SUNDAY INTO SUNDAY NIGHT. ANOTHER STRONGER WAVE MOVES INTO THE AREA AND A COLD FRONT MOVES THROUGH THE AREA SUNDAY AFTERNOON AND EVENING. THUNDERSTORMS WILL DEVELOP ALONG THE FRONT AS IT MOVES THROUGH. SOME OF THESE COULD BE SEVERE. MONDAY AND MONDAY NIGHT THE UPPER WAVE MOVES TO THE EAST AND A SURFACE HIGH PRESSURE MOVES INTO THE AREA...KEEPING THINGS DRY. AGAIN TUESDAY INTO TUESDAY NIGHT THERE ARE A FEW WEAK UPPER LEVEL WAVES THAT MOVE INTO THE PLAINS. MODELS HAVE SOME FAIRLY SPOTTY PRECIPITATION AROUND THE AREA WITH THESE UPPER LEVEL WAVES. THE GFS HAS MORE PRECIPITATION AROUND THAN THE ECMWF DOES. TEMPERATURES WILL BE SOMEWHAT VARIABLE THROUGH THE WEEK. WITH CLOUDS AROUND ON FRIDAY THE TEMPERATURES WILL BE A BIT COOLER...WARMING AFTER THE WARM FRONT LIFTS TO THE NORTH FOR SATURDAY AND SUNDAY THEN COOLING AGAIN AS THE COOL FRONT MOVE THROUGH MONDAY AND TUESDAY AND COOLING MORE AFTER THE FRONT MOVES THROUGH TUESDAY. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ AVIATION/1105 UPDATE/949 UPDATE...BRYANT 419 UPDATE/SHORT TERM/419 UPDATE...ROSSI LONG TERM...JCB
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
322 AM EDT THU MAY 24 2012 .SYNOPSIS... A SOUTHERLY FLOW OF WARM AIR WILL CONTINUE INTO THE HOLIDAY WEEKEND BRINGING AFTERNOON TEMPERATURES INTO THE 80S. AN UPPER LEVEL AREA OF LOW PRESSURE MAY TRIGGER A FEW THUNDERSTORMS THIS AFTERNOON..ESPECIALLY OVER THE POCONOS AND CATSKILLS. A WEAK FRONT PASSING THROUGH THE AREA ON FRIDAY MAY TRIGGER MORE WIDESPREAD THUNDERSTORMS. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WEAKNESS IN THE UPR RDG TO THE EAST ALLOWS FOR SOME INCRSD INSTABILITY OVER THE SRN AND ERN ZONES THIS AFTN. WILL CONT WITH THE FCST OF A CHANCE OR SLGT CHANCE OF TRWS IN THOSE AREAS. NAM HAS THE MOST CAPE...WITH BETTER THAN A THSND J/KG AT AVP LATE IN THE DAY. RUC AND ARW SEEM A BIT MORE RSNBL WITH ARND HALF THAT OF THE NAM. IN ANY CASE...THUNDER SHD BE ISLTD AND CHANCE OF SVR IS QUITE SMALL WITH A VERY WEAK WIND FIELD ALOFT. DENSE FOG THIS MRNG SHD ERODE QUICKLY WITH MIXING. MODELS GUID FOR HIGH TEMPS IN GOOD AGREEMENT WITH AFTN MAXES FROM THE MID 70S TO LOW 80S. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... YET ANOTHER WEAK BNDRY BANGS INTO THE RDGG SFC AND ALOFT ON FRI. NAM SHOWS SOME TALL AN SKINNY CAPE...ESP OVER THE NORTH ON FRI AFTN. LACK OF LL MOISTURE SHD LIMIT CONV DVLPMT BUT WITH THE BNDRY AND SOME WEAK HGT FALLS ALOFT...CHANCE POPS SEEM RSNBL FOR THE AFTN...WITH THE BEST CHANCE OVER THE NY COUNTIES. RDG BOUNCES BACK ON SAT WITH INCRSD HGTS AND WRMG ALOFT. THIS SERVES TO STABILIZE THE SNDG LIMITING THE PSBLTY OF AFTN TRW. SFC TEMPS BEGIN TO REBOUND AS WELL WITH TEMPS IN THE 80S ALL STATIONS AND THE MAV GUID PUSHING AVP INTO THE UPR 80S. ATTM THERE LOOKS TO BE LTL CHANCE OF SVR...AND WILL BE WELL BLO AND HEAT ADVISORY THRESHOLD SO WILL REMOVE CAUTIONARY WRDG FROM THE HWO AND JUST GO WITH A NIL STATEMENT. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... ON THE LARGE-SCALE...NWP AGREEMENT IS FAIRLY DECENT THAT HEIGHTS WILL RISE SIGNIFICANTLY OVER THE NERN STATES LATER IN THE WEEKEND AND EARLY NEXT WEEK...LEADING TO A PD OF ABV NORMAL TEMPS FOR LATE MAY (HIGHS WELL INTO THE 80S...PSBLY APPCHG 90 DEGS ON SUN AND MON). THE MAIN UNCERTAINTIES INVOLVE THE TRACK OF UPR-LVL WAVES ARND THE PERIPHERY OF THE RIDGE AXIS...AND PSBL CONVECTIVE DEVELOPMENT NEAR A WARM FRNTL BNDRY...AS IT LIFTS ACRS NY/PA. TO ACCOUNT FOR THIS SITN...WE`VE CONTINUED TO INDICATE THE POTENTIAL FOR SHRA/TSRA JUST ABT ANYTIME...FROM SUNDAY INTO MON. CERTAINLY...THIS PD WILL NOT BE A WASHOUT...AND WILL VERY LIKELY HAVE LONG PDS OF RAIN-FREE WX. HOWEVER...TIMING OF CONVECTIVE SYSTEMS/PSBL MCV`S THIS FAR OUT IS NEARLY IMPOSSIBLE...SO WE`LL RETAIN SCHC-CHC POPS. BY TUE...AS HEIGHTS BEGIN TO FALL ALOFT FROM THE NW...SIGNALLING THE APPROACH OF A COLD FRNT...WE MAY WELL SEE A BETTER OPPORTUNITY FOR SHRA/TSRA. EARLY INDICATIONS ARE THAT DRIER AND COOLER CONDS WILL FOLLOW BY THE MIDDLE OF NEXT WEEK. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... A MOIST SOUTHEAST FLOW WILL RESULT IN MVFR/IFR RESTRICTIONS LATER THIS MORNING. AT KRME/KSYR, ONLY MVFR RESTRICTIONS ARE EXPECTED AND AT KSYR IT MAY BE BRIEF. REST OF TERMINALS WILL SEE STRATUS AND FOG WITH IFR CONDITIONS BETWEEN 09Z-12Z. CONDITIONS WILL GRADUALLY IMPROVE TO VFR BY MID TO LATE MORNING WITH VFR EXPECTED FOR DURATION OF TAF PERIOD. ISOLATED CONVECTION IS POSSIBLE THIS AFTERNOON BUT NOT MENTIONED IN TAFS DUE TO LIMITED AREAL COVERAGE. LATE TONIGHT AFTER 06Z MORE IFR/MVFR RESTRICTIONS ARE POSSIBLE. LIGHT WINDS BECOMING S/SE AT 7-10 KNOTS THEN LIGHT AGAIN TONIGHT. .OUTLOOK... FRIDAY...MVFR POSSIBLE IN SCATTERED MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS. FRIDAY NIGHT THRU SUN...GENERALLY VFR. MONDAY...MVFR POSSIBLE IN SCATTERED SHOWERS AND THUNDERSTORMS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...DGM NEAR TERM...DGM SHORT TERM...DGM LONG TERM...MLJ/RRM AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
242 AM EDT THU MAY 24 2012 .SYNOPSIS... A SOUTHERLY FLOW OF WARM AIR WILL CONTINUE INTO THE HOLIDAY WEEKEND BRINGING AFTERNOON TEMPERATURES INTO THE 80S. AN UPPER LEVEL AREA OF LOW PRESSURE MAY TRIGGER A FEW THUNDERSTORMS THIS AFTERNOON..ESPECIALLY OVER THE POCONOS AND CATSKILLS. A WEAK FRONT PASSING THROUGH THE AREA ON FRIDAY MAY TRIGGER MORE WIDESPREAD THUNDERSTORMS. && .NEAR TERM /THROUGH TODAY/... WEAKNESS IN THE UPR RDG TO THE EAST ALLOWS FOR SOME INCRSD INSTABILITY OVER THE SRN AND ERN ZONES THIS AFTN. WILL CONT WITH THE FCST OF A CHANCE OR SLGT CHANCE OF TRWS IN THOSE AREAS. NAM HAS THE MOST CAPE...WITH BETTER THAN A THSND J/KG AT AVP LATE IN THE DAY. RUC AND ARW SEEM A BIT MORE RSNBL WITH ARND HALF THAT OF THE NAM. IN ANY CASE...THUNDER SHD BE ISLTD AND CHANCE OF SVR IS QUITE SMALL WITH A VERY WEAK WIND FIELD ALOFT. DENSE FOG THIS MRNG SHD ERODE QUICKLY WITH MIXING. MODELS GUID FOR HIGH TEMPS IN GOOD AGREEMENT WITH AFTN MAXES FROM THE MID 70S TO LOW 80S. && .SHORT TERM /TONIGHT THROUGH SATURDAY/... YET ANOTHER WEAK BNDRY BANGS INTO THE RDGG SFC AND ALOFT ON FRI. NAM SHOWS SOME TALL AN SKINNY CAPE...ESP OVER THE NORTH ON FRI AFTN. LACK OF LL MOISTURE SHD LIMIT CONV DVLPMT BUT WITH THE BNDRY AND SOME WEAK HGT FALLS ALOFT...CHANCE POPS SEEM RSNBL FOR THE AFTN...WITH THE BEST CHANCE OVER THE NY COUNTIES. RDG BOUNCES BACK ON SAT WITH INCRSD HGTS AND WRMG ALOFT. THIS SERVES TO STABILIZE THE SNDG LIMITING THE PSBLTY OF AFTN TRW. SFC TEMPS BEGIN TO REBOUND AS WELL WITH TEMPS IN THE 80S ALL STATIONS AND THE MAV GUID PUSHING AVP INTO THE UPR 80S. ATTM THERE LOOKS TO BE LTL CHANCE OF SVR...AND WILL BE WELL BLO AND HEAT ADVISORY THRESHOLD SO WILL REMOVE CAUTIONARY WRDG FROM THE HWO AND JUST GO WITH A NIL STATEMENT. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... 3 PM WED UPDATE... ON THE LARGE-SCALE...NWP AGREEMENT IS FAIRLY DECENT THAT HEIGHTS WILL RISE SIGNIFICANTLY OVER THE NERN STATES LATER IN THE WEEKEND AND EARLY NEXT WEEK...LEADING TO A PD OF ABV NORMAL TEMPS FOR LATE MAY (HIGHS WELL INTO THE 80S...PSBLY APPCHG 90 DEGS ON SUN AND MON). THE MAIN UNCERTAINTIES INVOLVE THE TRACK OF UPR-LVL WAVES ARND THE PERIPHERY OF THE RIDGE AXIS...AND PSBL CONVECTIVE DEVELOPMENT NEAR A WARM FRNTL BNDRY...AS IT LIFTS ACRS NY/PA. TO ACCOUNT FOR THIS SITN...WE`VE CONTINUED TO INDICATE THE POTENTIAL FOR SHRA/TSRA JUST ABT ANYTIME...FROM LATER SAT NGT RIGHT INTO MON. CERTAINLY...THIS PD WILL NOT BE A WASHOUT...AND WILL VERY LIKELY HAVE LONG PDS OF RAIN-FREE WX. HOWEVER...TIMING OF CONVECTIVE SYSTEMS/PSBL MCV`S THIS FAR OUT IS NEARLY IMPOSSIBLE...SO WE`LL RETAIN SCHC-CHC POPS. BY TUE...AS HEIGHTS BEGIN TO FALL ALOFT FROM THE NW...SIGNALLING THE APPROACH OF A COLD FRNT...WE MAY WELL SEE A BETTER OPPORTUNITY FOR SHRA/TSRA. EARLY INDICATIONS ARE THAT DRIER AND COOLER CONDS WILL FOLLOW BY THE MIDDLE OF NEXT WEEK. && .AVIATION /07Z THURSDAY THROUGH MONDAY/... A MOIST SOUTHEAST FLOW WILL RESULT IN MVFR/IFR RESTRICTIONS LATER THIS MORNING. AT KRME/KSYR, ONLY MVFR RESTRICTIONS ARE EXPECTED AND AT KSYR IT MAY BE BRIEF. REST OF TERMINALS WILL SEE STRATUS AND FOG WITH IFR CONDITIONS BETWEEN 09Z-12Z. CONDITIONS WILL GRADUALLY IMPROVE TO VFR BY MID TO LATE MORNING WITH VFR EXPECTED FOR DURATION OF TAF PERIOD. ISOLATED CONVECTION IS POSSIBLE THIS AFTERNOON BUT NOT MENTIONED IN TAFS DUE TO LIMITED AREAL COVERAGE. LATE TONIGHT AFTER 06Z MORE IFR/MVFR RESTRICTIONS ARE POSSIBLE. LIGHT WINDS BECOMING S/SE AT 7-10 KNOTS THEN LIGHT AGAIN TONIGHT. .OUTLOOK... FRIDAY...MVFR POSSIBLE IN SCATTERED MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS. FRIDAY NIGHT THRU SUN...GENERALLY VFR. MONDAY...MVFR POSSIBLE IN SCATTERED SHOWERS AND THUNDERSTORMS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...DGM NEAR TERM...DGM SHORT TERM...DGM LONG TERM...MLJ AVIATION...RRM
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
642 AM CDT THU MAY 24 2012 ...UPDATED FOR AVIATION... .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 408 AM CDT THU MAY 24 2012 THE SHORTER TERM MODELS OF THE NAM AND THE HRRR NOW SHOW THERE WILL NOT BE ANY PRECIP IN OUR FORECAST AREA TODAY. THE COLD FRONT IS THROUGH OUR CWA, WITH A LOW PRESSURE SYSTEM POSITIONED OVER SOUTHEAST COLORADO. AN UPPER LEVEL DISTURBANCE IS MOVING EAST-NORTHEAST BUT TRAVELING THROUGH AREAS NORTH OF OUR COUNTY WARNING AREA, NORTHERN KANSAS AND NEBRASKA AND POINTS NORTHEASTWARD. THERE IS SOME CIRRUS AROUND AND THINK THE GRIDS WILL PRODUCE MOSTLY SUNNY CONDITIONS. WHEN THE FRONT FIRST WENT THROUGH, THE WINDS BEHIND THE FRONT QUICKLY PICKED UP INTO ADVISORY LEVELS, AND THUS A SHORT TERM WIND ADVISORY WAS ISSUED FOR THAT AREA WEST OF A DIGHTON TO MONTEZUMA LINE, AND ALSO NORTH OF A JOHNSON CITY TO MONTEZUMA LINE. AT THE TIME OF WRITING THIS SHORT TERM DISCUSSION, WINDS HAD FALLEN BACK TO LESS THAN ADVISORY CRITERIA AT ALL SITES EXCEPT HUGOTON AND SCOTT CITY. THIS WIND ADVISORY WILL EXPIRE AT 09Z, AND SHOULD NOT SHOW UP IN THE NEXT ZONE ISSUANCE. TEMPERATURES TODAY WILL BE COOLER THAN YESTERDAY`S NEAR CENTURY MARKS, DUE TO THE COLD FRONTAL PASSAGE AND HIGH CLOUDS. HIGHS TODAY SHOULD RANGE FROM THE MID 80S ALONG THE OKLAHOMA PANHANDLE TO THE UPPER 70S NORTH OF THE I-70 CORRIDOR. THE COLD FRONT MENTIONED ABOVE WILL COME BACK NORTH TONIGHT AS A WARM FRONT. JUST HOW FAST NORTH IT WILL MOVES IS HANDLED DIFFERENTLY BY THE MODELS. THE NAM MODEL BRINGS THE FRONT NORTH THE FASTEST, WITH THE GFS AND ECMWF MODELS SLOWER. BY THE TIME THE FRONT REACHES OUR NORTHERN COUNTIES OF ELLIS, TREGO, RUSH, NESS, LANE AND SCOTT BY 09Z, THERE COULD BE A FEW THUNDERSTORMS FORM IN THE ELEVATED UNSTABLE LAYERS OF THE ATMOSPHERE. I ONLY PLACED 20 POPS IN, AS THE TIMING OF THE FRONT IS STILL IN QUESTION. CLOUDS WILL BLANKET MOST OF SOUTHWESTERN KANSAS THURSDAY NIGHT, AND WINDS NEAR THE OKLAHOMA BORDER WILL BE SOUTH AT 10 TO 20 MPH BEHIND THE FRONT AND EASTERLY AT 10 TO 20 MPH NORTH OF THE FRONT. TEMPERATURES THURSDAY NIGHT WILL BE SOMEWHAT ELEVATED, ONLY FALLING TO THE MID 60S IN THE MEDICINE LODGE AND PRATT AREAS, INTO THE LOWER 60S FROM LIBERAL TO DODGE CITY TO LARNED, AND INTO THE MIDDLE 50S FROM SYRACUSE TO SCOTT CITY TO WAKEENEY. .LONG TERM...(FRIDAY THROUGH THURSDAY) ISSUED AT 359 AM CDT THU MAY 24 2012 A CHALLENGING FORECAST LIES AHEAD FOR THE COMING SEVERAL DAYS, AS A FEW OPPORTUNITIES FOR CONVECTION APPEAR POSSIBLE. BY FRIDAY MORNING, A WARM FRONT WILL BE LIFTING NORTHWARD THROUGH SOUTHWEST KANSAS. THE MODELS DIFFER SIGNIFICANTLY WITH THIS FRONT. THE GFS PRODUCES QPF AS EARLY AS OVERNIGHT THURSDAY HEADING INTO FRIDAY MORNING, AND REALLY INCREASING THE QPF AROUND THE 12Z TIMEFRAME. BY CONTRAST THE NAM AND ECMWF ARE MORE IN LINE WITH A DRY SOLUTION. THE CONVECTION PRODUCED IN THESE CASES ARE MORE IN LINE WITH THE EDGE OF A CAPPING LATER IN THE MID LEVELS THAT IS LOCATED ACROSS NORTHERN KANSAS. IN EITHER CASE; STRONG LOW LEVEL THETA-E ADVECTION AND ISENTROPIC LIFT IN THE MORNING, OR BREAKING THE CAP LATE IN THE DAY FARTHER NORTH, QUARTER TO GOLFBALL SIZED HAIL WOULD BE LIKELY. HOWEVER, THE MOST LIKELY EVENT IS PROBABLY ALONG THE LINES OF THE ECMWF AND NAM GIVEN THE WARM TEMPERATURES IN THE MID LEVELS OF 13 TO 14 DEGREES C. IF THE WARM AIR ALOFT IS STRONG ENOUGH OF A CAP ON FRIDAY, THE POTENTIAL FOR SEVERE CONVECTION MIGHT BE RELEGATED EVEN FARTHER NORTH INTO NORTH CENTRAL KANSAS AND NEBRASKA. SURFACE TEMPERATURES WILL EXCEED 95 DEGREES IN THIS WARM BOUNDARY LAYER AIR AND LIKELY HIT 100 DEGREES OR MORE IN THE RED HILLS REGION. IT IS UNKNOWN AT THIS TIME IF THE SMOKE FROM THE NEW MEXICO FIRES WILL PLAY A ROLE IN INHIBITING INSOLATION WHICH IN TURN COULD PREVENT TEMPERATURES FROM REACHING THE AFOREMENTIONED VALUES. BUT IT IS SOMETHING TO CONSIDER IN THE NEXT 24 OR SO HOURS. HEADING INTO THE WEEKEND, A CONSENSUS OF THE MODELS WOULD SEEM TO SUPPORT AT LEAST SOME POTENTIAL FOR DRYLINE TRIGGERED CONVECTION ACROSS CENTRAL KANSAS ON SATURDAY. HOWEVER, IT IS NOT CLEAR AT ALL JUST WHERE THE DRYLINE MIGHT BE LOCATED AT THIS TIME. GENERALLY ISOLATED DISCREET CONVECTION WITHIN AMPLE SHEAR FOR AT LEAST THE POTENTIAL FOR SUPERCELLS PRODUCING UP TO GOLFBALL SIZED HAIL. A MORE ORGANIZED SEVERE CONVECTIVE POTENTIAL COULD OCCUR ON SUNDAY. THE FORCING MECHANISMS FOR THIS POTENTIAL WILL BE AN ADVANCING UPPER TROUGH WITH A LARGE COLD POOL (COOLING TEMPERATURES ALOFT) AND A LEAD UPPER JET`S RIGHT REAR QUADRANT. THE GFS AND ECMWF BOTH APPEAR TO SUPPORT A TORNADIC SUPERCELL ENVIRONMENT SUNDAY AFTERNOON ALONG THE WARM FRONT-SURFACE LOW INTERSECTION. BEYOND THIS PERIOD, THE FORECAST APPEARS TO CREATE MORE UNCERTAINTY. THE OVERALL CONSENSUS APPEARS TO BE A FLATTENING OF THE UPPER FLOW AS THE UPPER JET LIFTS INTO THE UPPER MIDWEST THROUGH TUESDAY. THIS SHOULD, WITH TIME ALLOW DRIER AIR TO SETTLE OVER WESTERN KANSAS REDUCING THE ODDS OF THUNDERSTORMS. BEFORE THE ECMWF AND GFS BOTH TREND RAPIDLY TOWARD STRONG MOISTURE RETURN AND CONVECTION ONCE AGAIN BY AROUND DAY 7. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 640 AM CDT THU MAY 24 2012 A COLD FRONT IS MOVING SOUTHEASTWARD THROUGH SOUTH CENTRAL KANSAS THIS MORNING. AS OF 11 UTC MSAS ANALYSIS, THE FRONT WAS POSITIONED FRONT NEAR KMHK TO KP28. THE SURFACE PRESSURE GRADIENT BEHIND THE FRONT WILL SLOWLY WEAKEN OVER THE AREA AS THE FRONT MOVES INTO CENTRAL OKLAHOMA. AS A RESULT, NORTHWEST SURFACE WIND WILL DIMINISH TO UNDER 20 KNOTS AT ALL SITES BY THE LATE MORNING. && .PRELIMINARY POINT TEMPS/POPS... DDC 83 62 98 70 / 0 10 10 10 GCK 82 60 97 68 / 0 10 10 10 EHA 85 59 93 66 / 0 10 10 10 LBL 85 62 96 68 / 0 10 10 10 HYS 80 59 89 69 / 10 20 20 20 P28 85 67 96 72 / 0 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BURKE LONG TERM...RUSSELL AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1152 AM EDT THU MAY 24 2012 .UPDATE... ISSUED AT 1148 AM EDT THU MAY 24 2012 ISSUED A WIND ADVISORY FOR THE REST OF CENTRAL AND ERN CWA AS WINDS WERE ALREADY GREATER THAN PREVIOUS FORECAST...AND A CORE OF 40-50KT 925MB WINDS WILL MOVE INTO THE CENTRAL AND ERN CWA AROUND 18Z. EXPECT GUSTS TO AROUND 45KTS TO BE ABLE TO MIX DOWN TO THE SFC THIS AFTERNOON. STILL WATCHING SEVERE THUNDERSTORM POTENTIAL THIS AFTERNOON/EVENING OVER MAINLY THE WESTERN HALF OF UPPER MI. WILL BE EXAMINING POPS/WX MORE CLOSELY FOR UPDATES IN THE NEXT COUPLE OF HOURS. && .SYNOPSIS... ISSUED AT 504 AM EDT THU MAY 24 2012 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW HI AMPLITUDE UPR RDG OVER THE NE CONUS/SE CANADA DOWNSTREAM OF DEEP UPR TROF IN THE ROCKIES. UNDER THE SW FLOW ALF BTWN THESE LARGER SCALE FEATURES...A SHRTWV/SFC LO LIFTING NEWD NEAR LK WINNIPEG WITH UPR DVGC IN RRQ OF SUPPORTING 100KT H3 JET MAX HAS CAUSED QUITE A BIT OF SHRA/TS IN MN MAINLY WITHIN AXIS OF DEEPER MSTR ON THE COLD SIDE OF SFC FNT OVER WRN LK SUP THAT IS ATTENDANT TO LK WINNIPEG LO. A FEW -SHRA/A LTG STRIKE OF TWO ARE JUST W OF IWD NEAR THE SFC COLD FNT LOCATION NOT FAR FM ASHLAND IN NW WI. TO THE E OVER MOST OF THE CWA...BONE DRY AIRMASS SHOWN ON THE 00Z GRB RAOB /PWAT 0.25 INCH WITH KINX -53/ IS BRINGING A TRANQUIL OVERNGT WITH JUST SOME SCT HI CLDS. THE APRCH OF ANOTHER STRONG SHRTWV ROTATING THRU THE WRN TROF IS CAUSING MORE SHRA/TS TO BREAK OUT IN NEBRASKA UNDER EXPANDING AREA OF COOLING CLD TOPS. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 504 AM EDT THU MAY 24 2012 MAIN FCST CONCERN DURING THIS TIME IS POTENTIAL FOR SVR WX LATE THIS EVNG ASSOCIATED WITH SHRTWV NOW ROUNDING THE BASE OF THE WRN TROF AND CAUSING EXPANDING AREA OF SHRA/TS AROUND NEBRASKA. TDAY...ALTHOUGH SOME OF THE SCT -SHRA NOW ALONG THE COLD FNT WL DRIFT INTO THE WRN ZNS EARLY THIS MRNG PER SLOWLY VEERING H85 FLOW TO SW AS SHOWN BY THE 00Z NAM...THE BULK OF THE RA NOW IN MN WL STAY W AND DIMINISH AS POCKET OF UPR DVGC IN RRQ OF JET MAX IN NW ONTARIO LIFTS TO THE NE. BUT WITH DRYNESS OF AIRMASS IN PLACE PER THE 00Z GRB RAOB AND HI AMPLITUDE RDG JUST TO THE E...THESE -SHRA SHOULD REMAIN OVER THE W AS THE SLOW MOVING COLD FNT STALLS WITH BACKING OF THE UPR FLOW ASSOCIATED WITH MOTION OF ROCKIES SHRTWV INTO THE PLAINS. THEN MOST OF THE DAY WILL FEATURE A GUSTY S WIND AS H85 WINDS INCRS TO 40-45KTS IN ADVANCE OF THE SHRTWV/DVLPG SFC LO IN THE PLAINS THAT IS FCST TO LIFT NEWD TO NOT FAR FM DLH BY 00Z. CONFINED CHC POPS TO THE W. DAYTIME HEATING/MIXING WL CAUSE WIND GUSTS TO AT LEAST APRCH ADVY CRITERIA WITH STEEP LLVL LAPSE RATES AS HI TEMPS SURGE INTO THE 80S AT SOME PLACES AWAY FM THE MODERATING INFLUENCE OF MAINLY LK MI. AFT COORDINATION WITH GRB...OPTED TO ISSUE WIND ADVY FOR MAINLY THE W HALF OF THE CWA AWAY FM THE MORE STABILIZED KEWEENAW PENINSULA TO ACCOUNT FOR DEEP MIXING...EXCEPTIONAL INTENSITY OF THE APRCHG DISTURBANCE/SFC LO PRES...AND GFS FCST H85/H925 S WINDS UP TO 60KTS/50KTS. GFS BUFKIT PROFILES INDICATE WINDS OF 35-40 KTS WL BE PRESENT IN MIXED LYR AT IWD. ALTHOUGH THE ARRIVAL OF HIER H95-9 SPECIFIC HUMIDITY IN THIS STRENGTHENING SLY FLOW WL KEEP MIN RH FM FALLING TO CRITICAL LVLS...THE GUSTY S WINDS WL STILL BE A CHALLENGE FOR THE PERSONNEL FIGHTING THE SENEY FIRE/OTHER WILDFIRES. MORE NMRS SHRA/TS ASSOCIATED WITH THE LO MOVING NEAR DLH MAY ARRIVE OVER THE FAR W IN THE 21Z-24Z TIME. TNGT...AS THE NEGATIVELY TILTED SHRTWV/SFC LO MOVE QUICKLY NE INTO ONTARIO...EXPECT A STRONG COLD FROPA ACRS THE CWA. VERY STRONG DYNAMICS THAT IMPACT MAINLY THE W HALF INCLUDE VIGOROUS DPVA/UPR DVGC IN THE LEFT EXIT OF SUPPORTING 130KT H3 JET MAX. ALTHOUGH FCST SDNGS DO NOT SHOW PARTICULARLY STEEP MID LVL LAPSE RATES...INVERTED V LOOK TO THE T/TD PROFILE IN THE SUB H8-85 LYR FOR IWD AT 00Z WITH EARLY EVNG FROPA THERE MAXIMIZING LLVL DESTABLIZATION AT PEAK HEATING TIME SUG THE POTENTIAL FOR DAMAGING WINDS WITH UNIDIRECTIONAL/SLOWLY VEERING POWERFUL FLOW THAT INCLUDES H7/H85 WINDS AS HI AS 60-70KTS/50-60KTS EVEN THOUGH THERE IS NOT A LOT OF MID LVL DRY AIR TO MAXIMIZE DCAPE. DESPITE THE STRONG WIND FIELDS...INVERTED V LLVL T/TD PROFILE AND LACK OF DIRECTIONAL SHEAR WOULD TEND TO MINIMIZE TORNADO THREAT. SINCE THE MID LVL LAPSE RATES ARE RELATIVELY WEAK AND LACK OF DRY MID LVL AIR RESULTS IN WBZ HGT IN THE 12.5-13.0K RANGE...THE LARGE HAIL THREAT DOES NOT APPEAR TOO HI. SINCE THE SHARPER DYNAMICS WL EXIT TO THE NE AND NOCTURNAL COOLING WL BEGIN TO HAVE AN IMPACT...EXPECT THE SHRA/TS CHCS AND SEVERE WX THREAT TO WANE AS THE FRONT MARCHES FARTHER E. VIGOROUS DRY SLOTTING/ARRIVAL OF LARGER SCALE QVECTOR DVGC IN THE WAKE OF THE FROPA WL CAUSE DIMINISHING POPS...BUT LINGERING LLVL MSTR MAY STILL CAUSE A FEW -SHRA IN THE UPSLOPE AREAS OF THE W THRU THE NGT. GIVEN STRENGTH OF THIS DISTURBANCE...CONCERNED W WINDS IN THE WAKE OF THE COLD FROPA WL REACH ADVY CRITERIA OVER MAINLY THE EXPOSED KEWEENAW PENINSULA AFT 06Z WITH W H925 WINDS INCRSG TO 40-50 KTS/VIGOROUS CAD THAT WL MAINTAIN STEEPER LLVL LAPSE RATES DESPITE SOME STABILIZATION OVER THE RELATIVELY COOL WATERS OF LK SUP/AND APRCH OF PRES RISE MAX OF 10-15MB/6HRS THAT WL ACCENTUATE ISALLOBARIC WIND COMPONENT NEARLY IN LINE WITH GRADIENT FLOW. FRI...WITH THE ARRIVAL OF DRIER AIR AND APRCH OF UPR RDG...EXPECT A DRY DAY. GUSTY WINDS WL PERSIST WITH DAYTIME HEATING/MIXING EVEN THOUGH THE PRES GRADIENT IS FCST TO SLOWLY SLACKEN. WITH H85 TEMPS TOPPING OUT IN THE 8-10C RANGE...MIXING TO H75 ON GFS/NAM FCST SDNGS YIELD HI TEMPS IN THE 75-80 RANGE WITH DOWNSLOPING FLOW AWAY FM LK MODERATION IN LLVL WNW FLOW. .LONG TERM...(AFTER MIDNIGHT FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 621 AM EDT THU MAY 24 2012 EXPECT WINDS TO DIMINISH AND BECOME NEARLY CALM FRIDAY NIGHT...AS TEMPS FALL INTO THE 40S. WENT WITH THE DRIER NON-NAM SOLUTION FOR MUCH OF THIS PERIOD...AS THE 24/00Z NAM WAS VERY OPTIMISTIC WITH ITS PRINTOUT OF PRECIP. OTHER CHANGES INCLUDED A WARMING OF TEMPS UP A COUPLE OF DEGREES FOR SATURDAY /COOLEST N NEAR LAKE SUPERIOR/...WITH A GENERALLY SLOWER ONSET OF PRECIP. THUNDERSTORMS SHOULD STAY ALONG THE WI BORDER THROUGH THE AFTERNOON HOURS. THESE THUNDERSTORMS WILL PUSH NORTHWARD...THANKS TO THE WARM FRONT. TEMPS SUNDAY WILL POP BACK INTO THE 70S WEST SUNDAY. WHILE WE DO HAVE A FCST FOR HIGH CHANCE POPS THROUGH MUCH OF THE DAY...THE BEST CHANCE WILL MORE THAN LIKELY BE THROUGH 18Z...BEFORE MUCH OF THE PRECIPITATION MOVES N ACROSS LAKE SUPERIOR. THUNDERSTORMS WILL END W TO E MONDAY AS THE SFC LOW PUSHES ACROSS AND EXITS E OF THE AREA. WHILE THERE ARE SILL SOME SIGNIFICANT DIFFERENCES BETWEEN THE MODELS...THEY ARE IN BETTER AGREEMENT FOR THIS PERIOD THAN 24 HRS AGO. THE SFC TROUGH WILL LINGER ACROSS THE CWA THROUGH TUESDAY WITH LOW CHANCE/SLIGHT CHANCE POPS LINGERING THROUGH THE END OF THE FCST PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 557 AM EDT THU MAY 24 2012 STRONG WINDS AND LLWS REMAIN A CONCERN THROUGH 12Z FRIDAY. SSW WINDS OF 50-55KTS CONTINUE TO SHOW UP ON THE MARQUETTE 88D RADAR...WHICH SHOULD ONLY TEMPORARILY DIMINISH ABOUT 5KTS OR SO BEFORE PICKING UP AGAIN THIS AFTERNOON...WITH 60KTS JUST AHEAD OF THE NEARING COLD FRONT TO OUR WEST. SHOWERS AND THUNDERSTORMS NEAR IWD AND CMX EARLY THIS MORNING WILL SLOWLY TRACK TO SAW AROUND OR SHORTLY AFTER 00Z FRIDAY. STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE ALONG THE COLD FRONT DURING THE AFTERNOON AND EVENING WITH CONVECTION...BEFORE DIMINISHING LATE TONIGHT. STRONG WINDS WILL REMAIN ALOFT...IF NOT AT THE SURFACE. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 621 AM EDT THU MAY 24 2012 ALTHOUGH S WINDS AT SOME OF THE HIGHER PLATFORMS LIKE STANNARD ROCK WILL PUSH 30-35 KTS INTO TONIGHT IN ADVANCE OF A DEEP LO PRES/STRONG COLD FRONT MOVING THRU WESTERN LK SUP THIS EVENING...HIGHER OVER WATER STABILITY WILL LIMIT THE MIXING OF THE STRONGER WINDS TO NEAR THE SURFACE. ONCE THE FRONT PASSES BY TONIGHT AND THE WIND SHIFTS TO THE W...EXPECT THE STRONGER WINDS TO MIX CLOSER TO THE SURFACE WITH THE ARRIVAL OF COOLER AIR. ALTHOUGH THERE IS SOME UNCERTAINTY HOW MUCH OF THE STRONGER FLOW WILL MAKE IT TO THE SURFACE...OPTED TO ISSUE GALE WATCH LATE TONIGHT THRU FRI MORNING FOR THE AREA BETWEEN ISLE ROYALE AND THE KEWEENAW WHERE TERRAIN WILL ENHANCE THE EXPECTED WSW FLOW. WINDS WILL DIMINISH ON FRI AFTERNOON WITH WEAKENING PRES GRADIENT. HIGH PRESSURE ACROSS CENTRAL CANADA FRIDAY NIGHT WILL CROSS ONTARIO AND LAKE SUPERIOR SATURDAY...BEFORE SETTLING ACROSS HUDSON BAY ON SUNDAY. LOW PRESSURE OVER THE NORTHERN PLAINS SUNDAY WILL FILL ACROSS THE UPPER GREAT LAKES MONDAY INTO MONDAY NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WIND ADVISORY UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR MIZ002- 004>007-009>014-084-085. LAKE SUPERIOR... GALE WATCH FROM LATE TONIGHT THROUGH FRIDAY MORNING FOR LSZ263- 264-266. LAKE MICHIGAN... NONE. && $$ UPDATE...TITUS SYNOPSIS...KC SHORT TERM...KC LONG TERM...KF AVIATION...KF MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
621 AM EDT THU MAY 24 2012 .SYNOPSIS... ISSUED AT 504 AM EDT THU MAY 24 2012 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW HI AMPLITUDE UPR RDG OVER THE NE CONUS/SE CANADA DOWNSTREAM OF DEEP UPR TROF IN THE ROCKIES. UNDER THE SW FLOW ALF BTWN THESE LARGER SCALE FEATURES...A SHRTWV/SFC LO LIFTING NEWD NEAR LK WINNIPEG WITH UPR DVGC IN RRQ OF SUPPORTING 100KT H3 JET MAX HAS CAUSED QUITE A BIT OF SHRA/TS IN MN MAINLY WITHIN AXIS OF DEEPER MSTR ON THE COLD SIDE OF SFC FNT OVER WRN LK SUP THAT IS ATTENDANT TO LK WINNIPEG LO. A FEW -SHRA/A LTG STRIKE OF TWO ARE JUST W OF IWD NEAR THE SFC COLD FNT LOCATION NOT FAR FM ASHLAND IN NW WI. TO THE E OVER MOST OF THE CWA...BONE DRY AIRMASS SHOWN ON THE 00Z GRB RAOB /PWAT 0.25 INCH WITH KINX -53/ IS BRINGING A TRANQUIL OVERNGT WITH JUST SOME SCT HI CLDS. THE APRCH OF ANOTHER STRONG SHRTWV ROTATING THRU THE WRN TROF IS CAUSING MORE SHRA/TS TO BREAK OUT IN NEBRASKA UNDER EXPANDING AREA OF COOLING CLD TOPS. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 504 AM EDT THU MAY 24 2012 MAIN FCST CONCERN DURING THIS TIME IS POTENTIAL FOR SVR WX LATE THIS EVNG ASSOCIATED WITH SHRTWV NOW ROUNDING THE BASE OF THE WRN TROF AND CAUSING EXPANDING AREA OF SHRA/TS AROUND NEBRASKA. TDAY...ALTHOUGH SOME OF THE SCT -SHRA NOW ALONG THE COLD FNT WL DRIFT INTO THE WRN ZNS EARLY THIS MRNG PER SLOWLY VEERING H85 FLOW TO SW AS SHOWN BY THE 00Z NAM...THE BULK OF THE RA NOW IN MN WL STAY W AND DIMINISH AS POCKET OF UPR DVGC IN RRQ OF JET MAX IN NW ONTARIO LIFTS TO THE NE. BUT WITH DRYNESS OF AIRMASS IN PLACE PER THE 00Z GRB RAOB AND HI AMPLITUDE RDG JUST TO THE E...THESE -SHRA SHOULD REMAIN OVER THE W AS THE SLOW MOVING COLD FNT STALLS WITH BACKING OF THE UPR FLOW ASSOCIATED WITH MOTION OF ROCKIES SHRTWV INTO THE PLAINS. THEN MOST OF THE DAY WILL FEATURE A GUSTY S WIND AS H85 WINDS INCRS TO 40-45KTS IN ADVANCE OF THE SHRTWV/DVLPG SFC LO IN THE PLAINS THAT IS FCST TO LIFT NEWD TO NOT FAR FM DLH BY 00Z. CONFINED CHC POPS TO THE W. DAYTIME HEATING/MIXING WL CAUSE WIND GUSTS TO AT LEAST APRCH ADVY CRITERIA WITH STEEP LLVL LAPSE RATES AS HI TEMPS SURGE INTO THE 80S AT SOME PLACES AWAY FM THE MODERATING INFLUENCE OF MAINLY LK MI. AFT COORDINATION WITH GRB...OPTED TO ISSUE WIND ADVY FOR MAINLY THE W HALF OF THE CWA AWAY FM THE MORE STABILIZED KEWEENAW PENINSULA TO ACCOUNT FOR DEEP MIXING...EXCEPTIONAL INTENSITY OF THE APRCHG DISTURBANCE/SFC LO PRES...AND GFS FCST H85/H925 S WINDS UP TO 60KTS/50KTS. GFS BUFKIT PROFILES INDICATE WINDS OF 35-40 KTS WL BE PRESENT IN MIXED LYR AT IWD. ALTHOUGH THE ARRIVAL OF HIER H95-9 SPECIFIC HUMIDITY IN THIS STRENGTHENING SLY FLOW WL KEEP MIN RH FM FALLING TO CRITICAL LVLS...THE GUSTY S WINDS WL STILL BE A CHALLENGE FOR THE PERSONNEL FIGHTING THE SENEY FIRE/OTHER WILDFIRES. MORE NMRS SHRA/TS ASSOCIATED WITH THE LO MOVING NEAR DLH MAY ARRIVE OVER THE FAR W IN THE 21Z-24Z TIME. TNGT...AS THE NEGATIVELY TILTED SHRTWV/SFC LO MOVE QUICKLY NE INTO ONTARIO...EXPECT A STRONG COLD FROPA ACRS THE CWA. VERY STRONG DYNAMICS THAT IMPACT MAINLY THE W HALF INCLUDE VIGOROUS DPVA/UPR DVGC IN THE LEFT EXIT OF SUPPORTING 130KT H3 JET MAX. ALTHOUGH FCST SDNGS DO NOT SHOW PARTICULARLY STEEP MID LVL LAPSE RATES...INVERTED V LOOK TO THE T/TD PROFILE IN THE SUB H8-85 LYR FOR IWD AT 00Z WITH EARLY EVNG FROPA THERE MAXIMIZING LLVL DESTABLIZATION AT PEAK HEATING TIME SUG THE POTENTIAL FOR DAMAGING WINDS WITH UNIDIRECTIONAL/SLOWLY VEERING POWERFUL FLOW THAT INCLUDES H7/H85 WINDS AS HI AS 60-70KTS/50-60KTS EVEN THOUGH THERE IS NOT A LOT OF MID LVL DRY AIR TO MAXIMIZE DCAPE. DESPITE THE STRONG WIND FIELDS...INVERTED V LLVL T/TD PROFILE AND LACK OF DIRECTIONAL SHEAR WOULD TEND TO MINIMIZE TORNADO THREAT. SINCE THE MID LVL LAPSE RATES ARE RELATIVELY WEAK AND LACK OF DRY MID LVL AIR RESULTS IN WBZ HGT IN THE 12.5-13.0K RANGE...THE LARGE HAIL THREAT DOES NOT APPEAR TOO HI. SINCE THE SHARPER DYNAMICS WL EXIT TO THE NE AND NOCTURNAL COOLING WL BEGIN TO HAVE AN IMPACT...EXPECT THE SHRA/TS CHCS AND SEVERE WX THREAT TO WANE AS THE FRONT MARCHES FARTHER E. VIGOROUS DRY SLOTTING/ARRIVAL OF LARGER SCALE QVECTOR DVGC IN THE WAKE OF THE FROPA WL CAUSE DIMINISHING POPS...BUT LINGERING LLVL MSTR MAY STILL CAUSE A FEW -SHRA IN THE UPSLOPE AREAS OF THE W THRU THE NGT. GIVEN STRENGTH OF THIS DISTURBANCE...CONCERNED W WINDS IN THE WAKE OF THE COLD FROPA WL REACH ADVY CRITERIA OVER MAINLY THE EXPOSED KEWEENAW PENINSULA AFT 06Z WITH W H925 WINDS INCRSG TO 40-50 KTS/VIGOROUS CAD THAT WL MAINTAIN STEEPER LLVL LAPSE RATES DESPITE SOME STABILIZATION OVER THE RELATIVELY COOL WATERS OF LK SUP/AND APRCH OF PRES RISE MAX OF 10-15MB/6HRS THAT WL ACCENTUATE ISALLOBARIC WIND COMPONENT NEARLY IN LINE WITH GRADIENT FLOW. FRI...WITH THE ARRIVAL OF DRIER AIR AND APRCH OF UPR RDG...EXPECT A DRY DAY. GUSTY WINDS WL PERSIST WITH DAYTIME HEATING/MIXING EVEN THOUGH THE PRES GRADIENT IS FCST TO SLOWLY SLACKEN. WITH H85 TEMPS TOPPING OUT IN THE 8-10C RANGE...MIXING TO H75 ON GFS/NAM FCST SDNGS YIELD HI TEMPS IN THE 75-80 RANGE WITH DOWNSLOPING FLOW AWAY FM LK MODERATION IN LLVL WNW FLOW. .LONG TERM...(AFTER MIDNIGHT FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 621 AM EDT THU MAY 24 2012 EXPECT WINDS TO DIMINISH AND BECOME NEARLY CALM FRIDAY NIGHT...AS TEMPS FALL INTO THE 40S. WENT WITH THE DRIER NON-NAM SOLUTION FOR MUCH OF THIS PERIOD...AS THE 24/00Z NAM WAS VERY OPTIMISTIC WITH ITS PRINTOUT OF PRECIP. OTHER CHANGES INCLUDED A WARMING OF TEMPS UP A COUPLE OF DEGREES FOR SATURDAY /COOLEST N NEAR LAKE SUPERIOR/...WITH A GENERALLY SLOWER ONSET OF PRECIP. THUNDERSTORMS SHOULD STAY ALONG THE WI BORDER THROUGH THE AFTERNOON HOURS. THESE THUNDERSTORMS WILL PUSH NORTHWARD...THANKS TO THE WARM FRONT. TEMPS SUNDAY WILL POP BACK INTO THE 70S WEST SUNDAY. WHILE WE DO HAVE A FCST FOR HIGH CHANCE POPS THROUGH MUCH OF THE DAY...THE BEST CHANCE WILL MORE THAN LIKELY BE THROUGH 18Z...BEFORE MUCH OF THE PRECIPITATION MOVES N ACROSS LAKE SUPERIOR. THUNDERSTORMS WILL END W TO E MONDAY AS THE SFC LOW PUSHES ACROSS AND EXITS E OF THE AREA. WHILE THERE ARE SILL SOME SIGNIFICANT DIFFERENCES BETWEEN THE MODELS...THEY ARE IN BETTER AGREEMENT FOR THIS PERIOD THAN 24 HRS AGO. THE SFC TROUGH WILL LINGER ACROSS THE CWA THROUGH TUESDAY WITH LOW CHANCE/SLIGHT CHANCE POPS LINGERING THROUGH THE END OF THE FCST PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 557 AM EDT THU MAY 24 2012 STRONG WINDS AND LLWS REMAIN A CONCERN THROUGH 12Z FRIDAY. SSW WINDS OF 50-55KTS CONTINUE TO SHOW UP ON THE MARQUETTE 88D RADAR...WHICH SHOULD ONLY TEMPORARILY DIMINISH ABOUT 5KTS OR SO BEFORE PICKING UP AGAIN THIS AFTERNOON...WITH 60KTS JUST AHEAD OF THE NEARING COLD FRONT TO OUR WEST. SHOWERS AND THUNDERSTORMS NEAR IWD AND CMX EARLY THIS MORNING WILL SLOWLY TRACK TO SAW AROUND OR SHORTLY AFTER 00Z FRIDAY. STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE ALONG THE COLD FRONT DURING THE AFTERNOON AND EVENING WITH CONVECTION...BEFORE DIMINISHING LATE TONIGHT. STRONG WINDS WILL REMAIN ALOFT...IF NOT AT THE SURFACE. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 621 AM EDT THU MAY 24 2012 ALTHOUGH S WINDS AT SOME OF THE HIGHER PLATFORMS LIKE STANNARD ROCK WILL PUSH 30-35 KTS INTO TONIGHT IN ADVANCE OF A DEEP LO PRES/STRONG COLD FRONT MOVING THRU WESTERN LK SUP THIS EVENING...HIGHER OVER WATER STABILITY WILL LIMIT THE MIXING OF THE STRONGER WINDS TO NEAR THE SURFACE. ONCE THE FRONT PASSES BY TONIGHT AND THE WIND SHIFTS TO THE W...EXPECT THE STRONGER WINDS TO MIX CLOSER TO THE SURFACE WITH THE ARRIVAL OF COOLER AIR. ALTHOUGH THERE IS SOME UNCERTAINTY HOW MUCH OF THE STRONGER FLOW WILL MAKE IT TO THE SURFACE...OPTED TO ISSUE GALE WATCH LATE TONIGHT THRU FRI MORNING FOR THE AREA BETWEEN ISLE ROYALE AND THE KEWEENAW WHERE TERRAIN WILL ENHANCE THE EXPECTED WSW FLOW. WINDS WILL DIMINISH ON FRI AFTERNOON WITH WEAKENING PRES GRADIENT. HIGH PRESSURE ACROSS CENTRAL CANADA FRIDAY NIGHT WILL CROSS ONTARIO AND LAKE SUPERIOR SATURDAY...BEFORE SETTLING ACROSS HUDSON BAY ON SUNDAY. LOW PRESSURE OVER THE NORTHERN PLAINS SUNDAY WILL FILL ACROSS THE UPPER GREAT LAKES MONDAY INTO MONDAY NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WIND ADVISORY FROM 1 PM EDT /NOON CDT/ THIS AFTERNOON TO 8 PM EDT /7 PM CDT/ THIS EVENING FOR MIZ002-004-005-009>011-084. LAKE SUPERIOR... GALE WATCH FROM LATE TONIGHT THROUGH FRIDAY MORNING FOR LSZ263- 264-266. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...KC SHORT TERM...KC LONG TERM...KF AVIATION...KF MARINE...KF
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
646 AM CDT THU MAY 24 2012 ...UPDATED AVIATION DISCUSSION... .DISCUSSION... /412 AM CDT THU MAY 24 2012/ Short Range (Today through Saturday)... Several questions have cropped up over the past 12-24 hours which has introduced some uncertainty with respect to temperatures and rain chances today and rain chances on Friday. The overall synoptic pattern features a broad upper trough from the Northern/Central Rockies into the Upper MS Valley and an associated cold front stretching from eastern MN through the OK/TX Panhandles. An embedded shortwave will lift northeast out of CO today resulting in a deepening surface low tracking northeast along the front from KS into western IA. The models have been consistent in tracking the cold front through the CWA today and then stalling just south of the forecast area tonight before lifting back north as a warm front on Friday. Any convection today will be along and west of the cold front as inspection of progged soundings east of the front depict an impressive elevated mixed layer(EML) which will act as a brick wall and prevent any convection forming within the warm sector. In addition the models have been generating a large area of clouds around 6k ft across KS during the pre-dawn hours which is expected to expand east across the forecast area this morning. This cloud cover will likely suppress surface heating across eastern KS/western MO today. Initially one could argue highs not making it out of the 70s. However, by mid/late afternoon the back edge of these clouds will probably scatter out and allow temperatures to rebound, possibly into the lower 80s. The eastern CWA should still be able to heat up into the mid/upper 80s before these clouds reach them. Short term convective models and conceptual models suggest convection will have a tough time developing today despite favorable vertical shear profiles. Marginal instability, a shortwave passing north of the region and minimal low level convergence should only support isolated convection. The severe threat will also be muted with north central and northeast MO having the best chance. First part of tonight will likely be dry as high pressure briefly settles in drawing cooler/drier air across most of the CWA. Have had to lower overnight temperatures due to degree of cool air behind the front. Building heights aloft on Friday will force the front north. How strong the isentropic ascent is north of the warm front will likely determine how much convection forms. NAM/GFS/ECMWF have been advertising varying amounts of qpf north of the warm front for the past several runs and hard to argue against it occurring. There are some signs that a vorticity lobe at h7 will develop across KS early Friday morning and provide additional support to generate scattered convection mainly north of the MO River. Some concern for severe potential across northwest MO/northeast KS during the afternoon. Location of the warm front during the afternoon will be key as there will be more than enough instability and shear to support severe storms. Considerable cloud cover north of the warm front will keep temperatures from warming. Temperatures will be able to heat up well into the 80s as the warm front lifts north. The hot and increasingly humid air will finally arrive on Saturday as mid/upper level heights build into the region. The EML will strengthen and keep us dry. Will be flirting with record high temperatures. MJ Medium Range (Sunday through Wednesday)... Temperatures will remain well above average on Sunday, though a slight decrease in 850 hPa temps will allow surface temps to be a couple of degrees cooler than Saturday. Deep upper ridge over the Southeast will break down on Monday as a closed upper low moves into the far Upper Midwest. This will allow a weak surface front to drop into the region Monday afternoon and evening with scattered showers and thunderstorms remaining a good bet with frontal passage through late Monday night. Upper pattern will transition to quasi-zonal by Tuesday and Wednesday as the front lingers just south of the forecast area. Elevated baroclinic region will set up a bit further north which could favor additional showers or thunderstorms depending on timing of weak upper impulses. Better chances for this right now appear to be on Wednesday, especially if the GFS is correct with its deeper surface ridge over the Plains on Tuesday. Hawblitzel && .CLIMATE... With the potential for near record temperatures over the holiday weekend, here are the normals and records through Memorial Day: Kansas City: Avg High/Low Record High Records Max Low Saturday 5/26........78/57...........92 in 1985........68 in 1987 Sunday 5/27..........78/58...........94 in 2006........70 in 2006 Monday 5/28..........78/58...........93 in 2006........75 in 2006 St. Joseph Saturday 5/26.........79/57..........94 in 1967, 1926...64 in 2008 Sunday 5/27...........79/58..........93 in 2006, 1966...69 in 1991 Monday 5/28...........80/58..........94 in 1998.........75 in 2006 && .AVIATION... For the 12z TAFs, marginal low level wind shear conditions will continue through at least mid morning before the low level jet mixes out and/or weakens. Gusty southerly winds will veer to the southwest as a weakening cold front approaches from the west. While VFR conditions will continue, a large area of cigs around 4k ft agl will overspread the terminals at the start of the forecast period. Prefer latest RUC which is closer to the current cigs moving across KS. A very warm layer just above these clouds will act as a block on any convective development. Could see a few sprinkles but no measurable rain is expected. MJ && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ WFO EAX
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1009 AM EDT THU MAY 24 2012 .SYNOPSIS... DEPARTING HIGH PRESSURE WILL BRING SOUTHERLY FLOW AND A CHANCE FOR UPSLOPE RAIN SHOWERS...MAINLY OVER THE HIGH TERRAIN TODAY. A BETTER CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS WILL ARRIVE LATE FRIDAY INTO FRIDAY NIGHT ASSOCIATED WITH A SURFACE COLD FRONT. SLIGHTLY COOLER AND DRIER CONDITIONS WILL PREVAIL FOR THE UPCOMING HOLIDAY WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1010 AM EDT THURSDAY...FCST IN GREAT SHAPE THIS MORNING WITH ONLY MINOR CHANGES NEEDED. VIS SATL PIC SHOWS LOW CLOUDS SLOWLY DISSIPATING ACRS EASTERN/CENTRAL VT AND PARTS OF THE DACKS. EXPECT AS SFC HEATING CONTS THESE CLOUDS WL DEVELOP INTO A SCATTERED/BROKEN CUMULUS/TOWERING CUMULUS DECK. RAP AND LOCAL BTV 4KM SHOWS SOME INSTABILITY DEVELOPING THIS AFTN AS SFC TEMPS WARM INTO THE U70S TO M80S...WITH CAPE VALUES AROUND 1000 J/KG AND LI VALUES NEAR -3C. HOWEVER...WATER VAPOR SHOWS LARGE AREA OF SUBSIDENCE AND ASSOCIATED DEEP DRY LAYER WITH BUILDING MID/UPPER LVL RIDGE ACRS OUR REGION. THIS WL LIMIT AREAL COVERAGE OF CONVECTION THIS AFTN...THINKING JUST A SCHC DACKS/SLV AND CENTRAL/EASTERN VT ZNS...WITH LOW CHC POPS NEAR KILLINGTON. MOST OF CWA WL BE RAINFREE THIS AFTN...WITH TEMPS IN THE M80S SLV TO L80S CPV TO M/U 70S MTNS. PREVIOUS DISCUSSION FOLLOWS...FOG WILL DISSIPATE THIS MORNING WITH CLOUDS MOVING IN FROM THE SOUTH EAST AS DEPARTING HIGH PRESSURE BRINGS SOUTHERLY TO SOUTHEASTERLY FLOW OVER THE REGION. THIS WILL ALLOW MOISTURE FROM YESTERDAYS FRONT TO SURGE NORTHWARD. A WEAK UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE FORECAST AREA TODAY. THIS FEATURE COMBINED WITH SOUTHEASTERLY UPSLOPE FLOW WILL BE ENOUGH CONVERGENCE TO DEVELOP FEW TO SCATTERED SHOWERS AND SLIGHT CHANCE FOR THUNDERSTORMS OVER THE HIGHER TERRAIN. BEST CHC FOR SHOWERS/STORMS WILL BE ACROSS EASTERN/CENTRAL VT GREEN MTNS AND HIGHER TERRAIN OF THE ADIRONDACKS. NAM AND GFS INDICATE AREAS OF OVER 1000J/KG THIS AFTERNOON. LACK OF SHEAR WILL KEEP ANY CONVECTIVE ACTIVITY SUB-SEVERE. WINDS MAINLY OUT OF THE SOUTH WILL CHANNEL UP THE CHAMPLAIN VALLEY...WITH SPEEDS OF 15-25 KTS OVER LAKE CHAMPLAIN AND OVER THE MTNS DURING THE DAY. 850HPA TEMPERATURES WILL WARM INTO THE MID TEENS OVER SOUTHERN VT AND UPPER TEENS IN NORTHERN NY. INCREASING CLOUDS WILL KEEP SFC TEMPS FROM REACHING FULL HEATING POTENTIAL OVER MOST OF VT. MAX TEMPS IN THE UPPER 70S TO AROUND 80 IN THE VALLEYS AND MID 60S TO LOW 70S OVER THE HIGHER TERRAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... AS OF 455 AM EDT THURSDAY...AS THE SUN SETS...INSTABILITY AND THEREFORE SHOWERS WILL DISSIPATE THIS EVENING. CLOUDS WILL CONTINUE TO INCREASE AS MOISTURE CONTINUES TO FILTER IN FROM THE SOUTHERLY FLOW. OVERNIGHT MIN TEMPS WILL BE IN THE LOW 60S IN THE VALLEYS AND REACHING THE MID 40S IN THE HIGHER TERRAIN. A COLD FRONT WILL APPROACH FROM THE GREAT LAKES REGION ON FRIDAY. GFS SLIGHTLY FASTER SOLUTION WITH BEST DEFORMATION OVER WESTERN NY BY 18Z. NAM A FEW HOURS SLOWER...BUT BOTH MODELS SHOW DEFORMATION WASHING OUT OVER EASTERN NY/SOUTHERN VT FRIDAY EVENING INTO SATURDAY MORNING. THIS COLD FRONT WILL BE ACCOMPANIED BY A MID LEVEL JET ENTRANCE REGION AT 850MB AND 700MB IN SOUTHEASTERN ONTARIO STRETCHING NORTHEAST INTO QUEBEC. CAN EXPECT SHOWERS AND THUNDERSTORMS TO AHEAD AND ACCOMPANYING THE COLD FRONT AS SOUTHERLY FLOW AHEAD OF THE FRONT CONTINUES TO BRING WARM MOIST AIR INTO THE REGION...AS NOTED BY SFC DEWPOINTS IN THE 60S. AS AN UPPER LEVEL TROF APPROACHES THE NORTHEAST...WIND SHEAR WILL INCREASE WITH BEST VALUES BETWEEN 25-30 KNOTS OF 0-3KM SHEAR AND 30-35 KTS OF 0-6 KM SHEAR. THIS MODEST SHEAR COMBINED WITH CAPE VALUES BETWEEN 1000 AND 2000 J/KG SUPPORT SCATTERED CONVECTION ALONG THE BOUNDARY WITH A FEW STRONGER STORMS. NOT ANTICIPATING A WIDESPREAD SEVERE WEATHER EVENT...BUT A FEW STRONGER STORMS WITH GUSTY WINDS AND DIME SIZE HAIL WILL BE POSSIBLE. SHOWERS AND THUNDERSTORM WILL CONTINUE INTO FRIDAY EVENING BEFORE THE FRONT MOVES THROUGH THE EASTERN EDGE OF THE FORECAST AREA AFTER MIDNIGHT. SATURDAY WILL SEE DRIER CONDITIONS BEHIND THE FRONT AS HIGH PRESSURE BUILDS IN OVER EASTERN ONTARIO/WESTERN QUEBEC. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 521 AM EDT THURSDAY...A RIDGE OF HIGH PRESSURE WILL BE OVER THE REGION SATURDAY NIGHT THROUGH SUNDAY NIGHT...WITH FAIR AND DRY WEATHER EXPECTED. A FRONTAL SYSTEM JUST SOUTH OF THE REGION SUNDAY NIGHT WILL BEGIN TO MOVE SLOWLY NORTHEAST AS A WARM FRONT ON MONDAY. EXPECTING SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS THE REGION MONDAY AFTERNOON AND CONTINUING INTO MONDAY NIGHT AND TUESDAY. A COLD FRONT WILL THEN MOVE THROUGH THE REGION TUESDAY NIGHT WITH A CHANCE FOR SOME MORE SHOWERS AND THUNDERSTORMS. EXPECTING COOLER TEMPERATURES ALONG WITH CLOUD COVER LINGERING ACROSS THE REGION ON WEDNESDAY...SO HAVE KEPT IN SLIGHT CHANCE POPS FOR SHOWERS ON WEDNESDAY. TEMPERATURE FORECAST FOR MONDAY AND TUESDAY COULD BE A BIT TRICKY AND WILL DEPEND ON WHERE THIS SLOW MOVING WARM FRONT WILL BE ACROSS THE REGION ON THESE DAYS. HAVE LEANED TOWARD ENSEMBLE MOS MEANS FOR MAX AND MIN TEMPERATURES ON MONDAY AND TUESDAY. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... THROUGH 12Z FRIDAY...MAINLY VFR CONDITIONS EXPECTED THROUGH THE PERIOD...EXCEPT FOR SOME AREAS OF MVFR/IFR IN FOG AND MIST EARLY THIS MORNING. EXPECTING AND FOG OR MIST WILL BURN OFF BY 14Z THURSDAY. VISIBLE SATELLITE LOOP SHOWING LOW STRATUS CLOUDS ACROSS EASTERN VERMONT AS OF 1130Z THURSDAY. THESE LOWER CEILINGS MAY NOT LIFT UNTIL 16-17Z THURSDAY. GUIDANCE SHOWING SOME STEEP LOW LEVEL LAPSE RATES TO DEVELOP ACROSS THE REGION TODAY...SO THERE COULD BE SOME ISOLATED SHOWERS AND A POSSIBLE THUNDERSTORMS THIS AFTERNOON. HAVE NOT INCLUDED ANY MENTION IN THE TAFS AT THIS TIME...DUE TO LOCALIZED NATURE OF THIS. SURFACE PRESSURE GRADIENT TO TIGHTEN ACROSS THE REGION TODAY...WITH SURFACE WINDGUSTS OF AROUND 20 KNOTS OR GREATER POSSIBLE BETWEEN 14Z-17Z THURSDAY AND CONTINUING UNTIL 00Z FRIDAY. EXPECTING SURFACE WINDS TO DIMINISH TO LESS THAN 10 KNOTS AFTER 00Z FRIDAY. EXPECTING SOME MORE AREAS OF IFR/MVFR CEILINGS IN FOG AND MIST...MAINLY AFTER 04Z FRIDAY...ESPECIALLY ACROSS EASTERN VERMONT. OUTLOOK 06Z FRIDAY THROUGH MONDAY... 06Z FRIDAY THROUGH 18Z FRIDAY...GENERALLY VFR UNDER RIDGE OF HIGH PRESSURE...WITH MORNING FOG/BR POSSIBLE. 18Z FRIDAY THROUGH 18Z MONDAY...GENERALLY VFR. 18Z MONDAY THROUGH 00Z TUESDAY CHANCES FOR MVFR IN SCATTERED SHOWERS/TSTORMS AS A WARM FRONT LIFTS SLOWLY NORTHEAST ACROSS THE REGION. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...KGM/TABER NEAR TERM...KGM/TABER SHORT TERM...KGM LONG TERM...WGH AVIATION...WGH
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
652 AM EDT THU MAY 24 2012 .SYNOPSIS... A SOUTHERLY FLOW OF WARM AIR WILL CONTINUE INTO THE HOLIDAY WEEKEND BRINGING AFTERNOON TEMPERATURES INTO THE 80S. AN UPPER LEVEL AREA OF LOW PRESSURE MAY TRIGGER A FEW THUNDERSTORMS THIS AFTERNOON..ESPECIALLY OVER THE POCONOS AND CATSKILLS. A WEAK FRONT PASSING THROUGH THE AREA ON FRIDAY MAY TRIGGER MORE WIDESPREAD THUNDERSTORMS. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WEAKNESS IN THE UPR RDG TO THE EAST ALLOWS FOR SOME INCRSD INSTABILITY OVER THE SRN AND ERN ZONES THIS AFTN. WILL CONT WITH THE FCST OF A CHANCE OR SLGT CHANCE OF TRWS IN THOSE AREAS. NAM HAS THE MOST CAPE...WITH BETTER THAN A THSND J/KG AT AVP LATE IN THE DAY. RUC AND ARW SEEM A BIT MORE RSNBL WITH ARND HALF THAT OF THE NAM. IN ANY CASE...THUNDER SHD BE ISLTD AND CHANCE OF SVR IS QUITE SMALL WITH A VERY WEAK WIND FIELD ALOFT. DENSE FOG THIS MRNG SHD ERODE QUICKLY WITH MIXING. MODELS GUID FOR HIGH TEMPS IN GOOD AGREEMENT WITH AFTN MAXES FROM THE MID 70S TO LOW 80S. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... YET ANOTHER WEAK BNDRY BANGS INTO THE RDGG SFC AND ALOFT ON FRI. NAM SHOWS SOME TALL AN SKINNY CAPE...ESP OVER THE NORTH ON FRI AFTN. LACK OF LL MOISTURE SHD LIMIT CONV DVLPMT BUT WITH THE BNDRY AND SOME WEAK HGT FALLS ALOFT...CHANCE POPS SEEM RSNBL FOR THE AFTN...WITH THE BEST CHANCE OVER THE NY COUNTIES. RDG BOUNCES BACK ON SAT WITH INCRSD HGTS AND WRMG ALOFT. THIS SERVES TO STABILIZE THE SNDG LIMITING THE PSBLTY OF AFTN TRW. SFC TEMPS BEGIN TO REBOUND AS WELL WITH TEMPS IN THE 80S ALL STATIONS AND THE MAV GUID PUSHING AVP INTO THE UPR 80S. ATTM THERE LOOKS TO BE LTL CHANCE OF SVR...AND WILL BE WELL BLO AND HEAT ADVISORY THRESHOLD SO WILL REMOVE CAUTIONARY WRDG FROM THE HWO AND JUST GO WITH A NIL STATEMENT. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... ON THE LARGE-SCALE...NWP AGREEMENT IS FAIRLY DECENT THAT HEIGHTS WILL RISE SIGNIFICANTLY OVER THE NERN STATES LATER IN THE WEEKEND AND EARLY NEXT WEEK...LEADING TO A PD OF ABV NORMAL TEMPS FOR LATE MAY (HIGHS WELL INTO THE 80S...PSBLY APPCHG 90 DEGS ON SUN AND MON). THE MAIN UNCERTAINTIES INVOLVE THE TRACK OF UPR-LVL WAVES ARND THE PERIPHERY OF THE RIDGE AXIS...AND PSBL CONVECTIVE DEVELOPMENT NEAR A WARM FRNTL BNDRY...AS IT LIFTS ACRS NY/PA. TO ACCOUNT FOR THIS SITN...WE`VE CONTINUED TO INDICATE THE POTENTIAL FOR SHRA/TSRA JUST ABT ANYTIME...FROM SUNDAY INTO MON. CERTAINLY...THIS PD WILL NOT BE A WASHOUT...AND WILL VERY LIKELY HAVE LONG PDS OF RAIN-FREE WX. HOWEVER...TIMING OF CONVECTIVE SYSTEMS/PSBL MCV`S THIS FAR OUT IS NEARLY IMPOSSIBLE...SO WE`LL RETAIN SCHC-CHC POPS. BY TUE...AS HEIGHTS BEGIN TO FALL ALOFT FROM THE NW...SIGNALLING THE APPROACH OF A COLD FRNT...WE MAY WELL SEE A BETTER OPPORTUNITY FOR SHRA/TSRA. EARLY INDICATIONS ARE THAT DRIER AND COOLER CONDS WILL FOLLOW BY THE MIDDLE OF NEXT WEEK. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... CONDITIONS HAVE IMPROVED RAPIDLY EARLY THIS MORNING WITH ONLY LINGERING MVFR CONDITIONS POSSIBLE THROUGH 14Z. REMAINDER OF TODAY WILL FEATURE VFR CONDITIONS WITH SCT/BKN CLOUDS AT 4K FT. ISOLATED CONVECTION IS POSSIBLE THIS AFTERNOON BUT NOT MENTIONED IN TAFS DUE TO LIMITED AREAL COVERAGE. MOIST SOUTHEAST FLOW WILL BRING MORE RESTRICTIONS LATE TONIGHT ESPECIALLY ACROSS NE PA AND SOUTHERN TIER OF NEW YORK. FOR NOW WENT MVFR AFTER 06Z. S/SE AT 7-10 KNOTS. .OUTLOOK... FRIDAY...MVFR POSSIBLE IN SCATTERED MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS. FRIDAY NIGHT THRU SUN...GENERALLY VFR. MONDAY...MVFR POSSIBLE IN SCATTERED SHOWERS AND THUNDERSTORMS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...DGM NEAR TERM...DGM SHORT TERM...DGM LONG TERM...MLJ/RRM AVIATION...RRM
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1000 AM EDT THU MAY 24 2012 .SYNOPSIS... WEAK HIGH PRESSURE WILL REMAIN OVER THE EAST COAST INTO THE WEEKEND AS A WEAKENING COLD FRONT APPROACHES FROM THE WEST AND BECOMES STATIONARY ACROSS LAKE ERIE FRIDAY EVENING. THE FRONT WILL LINGER NEAR THE SOUTH SHORE OF LAKE ERIE SATURDAY AND DRIFT NORTH AS A WARM FRONT SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 12Z SOUNDINGS SUPPORT THE CURRENT FORECAST WITH MINOR CHANGES. THE STRONGER PRESSURE GRADIENT WITH SOUTHERLY FLOW WILL LIMIT THE LAKE BREEZE TO THE IMMEDIATE LAKESHORE. WILL LOWER MAX TEMPERATURE AT ERI A TAD. THE HRRR SHOWS WIDELY SCATTERED CONVECTION OVER NW PA AND THE EASTERN COUNTIES SO WILL KEEP THE 20 PERCENT POP GOING. WATER VAPOR SHOWS SMALL VORTICITES OVER THE WESTERN CAROLINAS AND DELMARVA ALL MOVING NORTHEAST. THESE FEATURES SHOULD NOT AFFECT THE AREA SO FORECING FOR CONVECTION IS DIFFICULT TO DISCERN. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... UNCERTAINTY CONTINUES WITH THE FORECAST FOR THE HOLIDAY WEEKEND. A WEAKENING COLD FRONT WILL MOVE ACROSS THE REGION ON FRIDAY WHICH WILL BRING THE CHANCE OF THUNDERSTORMS...MAINLY ACROSS THE EASTERN THIRD OF THE COUNTY WARNING AREA. WE WILL HAVE TO MONITOR THE STRENGTH OF STORMS THAT DEVELOP AHEAD OF THE FRONT ACROSS NW PA FRIDAY AFTERNOON/EVENING. BY FRIDAY NIGHT THE FRONTAL BOUNDARY WILL STALL OVER CENTRAL OHIO. THIS BOUNDARY WILL THEN LIFT BACK TO THE NORTH BY SATURDAY AFTERNOON. THIS IS WHEN THE UNCERTAINTY ARRIVES IN THE FORECAST. MODELS ARE DIFFERING ON HOW FAST TO MOVE THE WARM FRONT NORTH. THIS COULD END UP HAVING SIGNIFICANT IMPACTS ON WHERE THUNDERSTORMS OCCUR AND HOW WARM THE REGION CAN GET SATURDAY INTO SUNDAY. FOR NOW WE HAVE LEANED TOWARD THE ECMWF SOLUTION THAT LIFTS THE BOUNDARY NORTHWARD SLIGHTLY FASTER AND KEEPS THE CHANCES OF THUNDERSTORMS NORTH OF A KTOL TO MEADVILLE LINE SATURDAY NIGHT AND THEN NORTH OF THE LAKE ON SUNDAY. SINCE WE HAVE LEANED TOWARD THE ECMWF TRENDS WE EXPECT TO SEE HIGHS NEAR TO SLIGHTLY WARMER THAN THE CURRENT GUIDANCE. HIGHER DEWPOINTS WILL MAKE IT FEEL EVEN WARMER WITH HEAT INDEX VALUES INTO THE LOWER AND MIDDLE 90S ON SUNDAY. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... MODELS CONTINUE TO LOOK VERY WARM TO HOT ON MON. AN APPROACHING COLD FRONT COULD TRIGGER AN ISOLATED TSRA FOR MAINLY THE NW HALF. TIMING OF COLD FRONT LATE MON NIGHT INTO TUE SO WILL KEEP PLAN TO SPREAD CHANCE POPS SE THESE PERIODS...SHIFTING SMALL CHANCE INTO MAINLY THE SE FOR TUE NIGHT. TEMPS COOL SOME FOR TUE AND MORE SO FOR WED AS NW FLOW CONTINUES TO BRING COOLER AIR INTO THE AREA FROM CANADA. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... ANY PATCHY DAYBREAK FOG WILL DISSIPATE BY 13Z. WILL SEE SCT TO LOCALLY BKN CU DEVELOP DURING MIDDAY HOURS THEN DISSIPATE TOWARD SUNSET. AN ISOLATED SHRA OR TSRA COULD DEVELOP IN THE AFTERNOON OVER THE EAST BUT NOT ENOUGH COVERAGE TO MENTION IN TAF. CAK AND YNG WOULD BE MOST LIKELY SITES TO BE AFFECTED BY ANY ISOLATED CONVECTION THAT WOULD DEVELOP. SOUTH TO SE FLOW SETS UP TODAY AND COULD GUST AROUND 20 KNOTS THIS AFTERNOON AND TONIGHT NEAR THE LAKESHORE. .OUTLOOK...NON-VFR POSSIBLE IN ISOLD TO SCT TSRA FRI THRU MON AND PATCHY DAYBREAK BR AND HZ. && .MARINE... LIGHT SE FLOW WILL INCREASE SOME TODAY AND A LITTLE MORE TONIGHT AHEAD OF A WEAKENING COLD FRONT THAT WILL CROSS THE LAKE FRI MORNING. WARM TEMPS OVER THE COOLER LAKE SHOULD KEEP WIND SPEEDS 15 KNOTS OR LESS MOST OF THE TIME. FLOW BECOMES WSW AFTER FROPA FRI AFTERNOON BUT SHOULD QUICKLY DIMINISH INTO THE EVENING AS HIGH PRESSURE MOVES OVER THE LAKE. THE FLOW SHOULD VEER AROUND TO NE FOR SAT. FORECAST FOR LATER SAT NIGHT AND SUN MORE UNCERTAIN AS MODELS DIFFER ON HOW QUICKLY A WARM FRONT WILL LIFT NORTH THROUGH THE LAKE. THINK BY SUN NIGHT THE FRONT SHOULD HAVE MOVED NORTH OF THE LAKE AND WINDS SHOULD BE MAINLY SSW...AND CONTINUE ON MON. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...MULLEN NEAR TERM...REL SHORT TERM...MULLEN LONG TERM...ADAMS AVIATION...ADAMS MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
258 PM MDT THU MAY 24 2012 .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 256 PM MDT THU MAY 24 2012 EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW BROAD TROUGH EXTENDING FROM THE PACIFIC NORTHWEST ACROSS T HE NORTHERN PLAINS...WITH WEST/SOUTHWEST FLOW OVER THE CENTRAL ROCKIES AND CENTRAL HIGH PLAINS. A SERIES OF SHORTWAVE TROUGHS ARE CURRENTLY TRACKING WITHIN THE MEAN FLOW WITH SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THESE FEATURES OVER NORTHERN COLORADO AND NORTH CENTRAL NEBRASKA. A STATIONARY FRONT EXTENDS FROM EASTERN KANSAS SOUTH INTO NORTHCENTRAL TEXAS...AND THEN NORTH INTO SOUTH-CENTRAL COLORADO. TONIGHT...A CLOSED LOW CENTER WITHING THE LARGE SCALE TROUGH WILL MOVE EAST/NORTHEAST INTO THE NORTHERN PLAINS WITH LARGE SCALE ASCENT SPREADING SOUTH AND EAST TOWARDS SOUTHWEST NEBRASKA. THE STATIONARY FRONT TO THE SOUTH WILL BEGIN TO MOVE NORTH IN RESPONSE TO STRENGTHENING LEE TROUGH OVER EASTERN COLORADO. A STRONG LLJ IS ADVERTISED TO DEVELOP BY 06Z TONIGHT WHICH COULD ALSO ACT AS A FOCUS FOR SHOWER THUNDERSTORM DEVELOPMENT OVER OUR CWA. VERY STRONG SHEAR WILL DEVELOP OVERNIGHT ALONG WITH ELEVATED INSTABILITY NEAR THE NOSE OF THE LLJ. BEST FORCING LOOKS TO BE EITHER NORTH OR SOUTH OF THE CWA. IM ALSO NOT SURE ABOUT HOW MUCH TD WILL RECOVER NORTH OF THE FRONT. I KEPT POPS IN THE SLIGHT CHANCE/CHANCE CATEGORY...WITH BEST COVERAGE LATE TONIGHT WHEN LLJ IS EXPECTED TO DEVELOP. THERE CONTINUES TO BE INDICATION OF FOG DEVELOPMENT WITH EASTERLY FLOW AROUND SUNRISE TOMORROW...SO I KEPT PATCHY FOG MENTION. FRIDAY..SHOWER/THUNDERSTOM ACTIVITY SHOULD COME TO AN END FROM THE SOUTHWEST TO THE NORTHEAST THROUGH THE DAY...WITH ACTIVITY POSSIBLY LINGERING OVER NORTHERN PARTS OF THE FORECAST AREA INTO FRIDAY EVENING. THERE IS A LARGE SPREAD IN GUIDANCE ON TIMING OF WARM FRONT FRIDAY WITH NAM THE SLOW OUTLIER. NAM SOLUTION WOULD KEEP STRATUS/FOG IN PLACE ALONG WITH MUCH COOLER AIRMASS. GFS/ECMWF FAVOR THE CLEARING SOLUTION ALONG WITH MUCH WARMER TEMPERATURES ACROSS THE SOUTHWEST..WHICH IS WHERE I LEANED THIS FORECAST CYCLE. FRIDAY NIGHT...PRIMARY ADJUSTMENT TO THIS PERIOD WAS TO BUMP OVERNIGHT LOWS UP A NOTCH OR TWO WITH SOUTHERLY/SOUTHEASTERLY FLOW IN PLACE ACROSS THE FORECAST AREA. WILL SEE SLIGHT CHANCE/CHANCE POPS OVER THE FAR NORTHEAST PORTION OF THE FORECAST AREAS DURING THE OVERNIGHT HOURS BEFORE SHIFTING OUT OF THE AREA BY AROUND SUNRISE ON SATURDAY. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 256 PM MDT THU MAY 24 2012 ACTIVE WEATHER PATTERN SETTING UP FOR THE EXTENDED WITH A FEW PERIODS OF STRONG TO SEVERE CONVECTION APPEARING POSSIBLE. SATURDAY AND SATURDAY NIGHT...WARM FRONT LIFTS NORTH INTO NEBRASKA DURING THE DAY WITH A DRYLINE SETTING UP. H85 TEMPS WARM TO AROUND 30C OVER EASTERN COLORADO WITH MID TO UPPER 20S C ELSEWHERE. RESULT WILL BE AFTERNOON TEMPS APPROACHING THE CENTURY MARK IN A FEW LOCATIONS. EVERYONE SHOULD SEE AT LEAST THE LOW/MID 90S. SATURDAY LOOKS TO BE A VERY WINDY DAY ACROSS AT LEAST THE WESTERN TWO-THIRDS OF THE FORECAST AREA WITH LATEST GUIDANCE HINTING AT THE POTENTIAL FOR BORDERLINE HIGH WIND WARNING GUSTS. CONSIDERED HOISTING A HIGH WIND WATCH FOR WESTERN HALF BUT OPTED TO HOLD OFF AND ALLOW OVERNIGHT SHIFT TO HAVE ANOTHER RUN OF NWP GUIDANCE. AT THE LEAST...APPEARS AS THOUGH A WIND ADVISORY WILL BE NEEDED FOR MUCH OF THE AREA. DEW POINTS WILL TANK ACROSS THE WEST WHICH WILL RESULT IN RH VALUES FALLING TO AROUND 10 PERCENT. FUELS PAGE INDICATES SUFFICIENT GREEN-UP IS ONGOING WHICH MAY LIMIT FIRE WEATHER POTENTIAL BUT THIS IS ALSO SOMETHING THAT WILL NEED TO BE MONITORED OVER THE NEXT FEW FORECAST SHIFTS. DISCREPANCIES DO EXIST IN THE PLACEMENT OF THE DRYLINE BUT A SLIGHT CHANCE FOR CONVECTION OVER THE EASTERN HALF OF THE FORECAST AREA APPEARS JUSTIFIED. GIVEN INVERTED-V NATURE OF VERTICAL SOUNDING PROFILES...ANY STORM WHICH DEVELOPS WILL HAVE THE POTENTIAL TO PRODUCE STRONG WIND GUSTS. LARGE HAIL WILL ALSO BE POSSIBLE THOUGH SHEAR PROFILES DON`T BECOME STRONGLY FAVORABLE UNTIL AFTER 00Z. SUNDAY AND SUNDAY NIGHT...POTENT MID/UPPER TROUGH WILL BEGIN TO TRANSLATE ACROSS THE GREAT BASIN/ROCKIES ON SUNDAY WITH INCREASING FORCING FOR ASCENT AS THE DAY PROGRESSES. PRIMARY QUESTION WILL BE THE ULTIMATE LOCATION OF THE DRYLINE. EAST OF THE DRYLINE...DEW POINT WILL SURGE INTO THE UPPER 50S AND PERHAPS EVEN THE LOWER 60S. DEEP LAYER SHEAR OF 40 TO 50 KTS WILL AID IN UPDRAFT ORGANIZATION WHILE STRONG LOW LEVEL PARAMETERS WOULD ALSO SUPPORT A TORNADO THREAT. GREATEST THREAT IS CURRENTLY INDICATED TO BE GENERALLY ALONG AND EAST OF THE HIGHWAY 83 CORRIDOR. INTERESTED PARTIES WILL WANT TO CLOSELY MONITOR THE LATEST FORECAST INFORMATION. MONDAY THROUGH TUESDAY...PRIMARY MID/UPPER LOW SHIFTS EASTWARD ACROSS THE SOUTHERN PRAIRIE PROVINCES OF CANADA MONDAY INTO TUESDAY MORNING WITH WEAK RIDGING/QUASI-ZONAL FLOW ACROSS THE CENTRAL HIGH PLAINS. RESULT SHOULD BE SEASONABLE TEMPS WITH DRY CONDITIONS EXPECTED UNTIL AT LEAST TUESDAY AFTERNOON WHEN A SHORTWAVE TROUGH MOVES ACROSS THE AREA. WEDNESDAY THROUGH THURSDAY...MID/UPPER RIDGING BUILDS ACROSS THE WESTERN CONUS WITH A NEGATIVELY TILTED SHORTWAVE TROUGH AND AN ASSOCIATED SURFACE COLD FRONT DROPPING SOUTHEAST ACROSS THE DAKOTA AND NEBRASKA. BROAD SCALE FORCING FOR ASCENT INCREASES BY WEDNESDAY AFTERNOON WHICH WILL AID IN THE DEVELOPMENT OF CONVECTION OVER PRIMARILY SOUTHWEST NEBRASKA AND NORTHWEST KANSAS. WILL CARRY PRIMARILY CHANCE POPS DURING THIS TIME PERIOD WITH MUCH COOLER AIR FILTERING INTO THE REGION BEHIND THE FRONT ON THURSDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1145 AM MDT THU MAY 24 2012 VFR CONDITIONS ARE EXPECTED TO PREVAIL AT BOTH KGLD AND KMCK TERMINALS THROUGH LATE TONIGHT. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ACROSS THE AREA TONIGHT. BASED ON EXPECTED SCATTERED COVERAGE I INCLUDED VCTS AT BOTH TERMINALS AFTER 04-05Z. BRIEF MVFR CONDITIONS WILL BE POSSIBLE IF A STORM DIRECTLY IMPACTS ONE OF THE TERMINALS. MVFR CONDITIONS SHOULD PREVAIL AFTER 10-11Z AS GOOD BL MOISTURE ADVECTS NORTH AND EAST WITH EASTERLY FLOW DEVELOPING ACROSS THE AREA. THERE IS STILL A LOT OF SPREAD IN GUIDANCE ON FRONTAL TIMING FRIDAY...WITH NAM SLOWER AND HOLDING STRATUS/FOG ON LONGER. NAM/MET WOULD ALSO INDICATE SIGNIFICANTLY LOWER CIGS OVER BOTH TERMINALS. THIS IS THE OUTLIER...SO CONFIDENCE IS HIGHER THAT CONDITIONS SHOULD IMPROVE TO VFR BY MID MORNING OVER KGLD AND AROUND 18Z AT KMCK. && .CLIMATE... ISSUED AT 245 AM MDT THU MAY 24 2012 RECORD AND NEAR RECORD HIGH TEMPERATURES EXPECTED SATURDAY. GOODLAND.....97 IN 2006 HILL CITY....99 IN 1912 MCCOOK.......98 IN 1967 BURLINGTON...95 IN 1942 YUMA.........96 TRIBUNE......101 COLBY........98 && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR/FOLTZ LONG TERM...FOLTZ AVIATION...DR CLIMATE...007
AREA FORECAST DISCUSSION
NWS GOODLAND KS
127 PM MDT THU MAY 24 2012 .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 125 PM MDT THU MAY 24 2012 EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW BROAD TROUGH EXTENDING FROM THE PACIFIC NORTHWEST ACROSS T HE NORTHERN PLAINS...WITH WEST/SOUTHWEST FLOW OVER THE CENTRAL ROCKIES AND CENTRAL HIGH PLAINS. A SERIES OF SHORTWAVE TROUGHS ARE CURRENTLY TRACKING WITHIN THE MEAN FLOW WITH SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THESE FEATURES OVER NORTHERN COLORADO AND NORTH CENTRAL NEBRASKA. A STATIONARY FRONT EXTENDS FROM EASTERN KANSAS SOUTH INTO NORTHCENTRAL TEXAS...AND THEN NORTH INTO SOUTHCENTRAL COLORADO. A CLOSED LOW CENTER WITHING THE LARGE SCALE TROUGH WILL MOVE EAST/NORTHEAST INTO THE NORTHERN PLAINS WITH LARGE SCALE ASCENT SPREADING SOUTH AND EAST TOWARDS SOUTHWEST NEBRASKA. THE STATIONARY FRONT TO THE SOUTH WILL BEGIN TO MOVE NORTH IN RESPONSE TO STRENGTHENING LEE TROUGH OVER EASTERN COLORADO. A STRONG LLJ IS ADVERTISED TO DEVELOP BY 06Z TONIGHT WHICH COULD ALSO ACT AS A FOCUS FOR SHOWER THUNDERSTORM DEVELOPMENT OVER OUR CWA. VERY STRONG SHEAR WILL DEVELOP OVERNIGHT ALONG WITH ELEVATED INSTABILITY NEAR THE NOSE OF THE LLJ. BEST FORCING LOOKS TO BE EITHER NORTH OR SOUTH OF THE CWA. IM ALSO NOT SURE ABOUT HOW MUCH TD WILL RECOVER NORTH OF THE FRONT. I KEPT POPS IN THE SLIGHT CHANCE/CHANCE CATEGORY...WITH BEST COVERAGE LATE TONIGHT WHEN LLJ IS EXPECTED TO DEVELOP. THERE CONTINUES TO BE INDICATION OF FOG DEVELOPMENT WITH EASTERLY FLOW AROUND SUNRISE TOMORROW...SO I KEPT PATCHY FOG MENTION. FRIDAY..SHOWER/THUNDERSTOM ACTIVITY SHOULD COME TO AN END FROM THE SOUTHWEST TO THE NORTHEAST THROUGH THE DAY...WITH ACTIVITY POSSIBLY LINGERING OVER NORTHERN PARTS OF THE FORECAST AREA INTO FRIDAY EVENING. THERE IS A LARGE SPREAD IN GUIDANCE ON TIMING OF WARM FRONT FRIDAY WITH NAM THE SLOW OUTLIER. NAM SOLUTION WOULD KEEP STRATUS/FOG IN PLACE ALONG WITH MUCH COOLER AIRMASS. GFS/ECMWF FAVOR THE CLEARING SOLUTION ALONG WITH MUCH WARMER TEMPERATURES ACROSS THE SOUTHWEST..WHICH IS WHERE I LEANED THIS FORECAST CYCLE. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 245 AM MDT THU MAY 24 2012 FRIDAY NIGHT-SATURDAY NIGHT...WINDS BECOME SOUTH/SOUTHWEST AS WARM FRONT LIFTS NORTH OF THE AREA FRIDAY NIGHT. ON SATURDAY INCREASING PRESSURE GRADIENT BETWEEN LIFTING UPPER LOW INTO IDAHO AND UPPER HIGH ACROSS THE SOUTH WILL PRODUCE VERY WINDY CONDITIONS. JUST HOW WINDY IS THE QUESTION. SHOULD SEE SOLID ADVISORY CRITERIA WINDS ACROSS MUCH OF THE AREA...CANT COMPLETELY RULE OUT WARNING CRITERIA GUSTS JUST YET. HIGH TEMPERATURES WELL INTO THE 90S. MAY SEE A FEW STRONG TO SEVERE THUNDERSTORMS DURING THE AFTERNOON AND EVENING HOURS ALONG AND EAST OF THE DRYLINE WHICH RIGHT NOW IS EXPECTED EAST OF THE CO/KS BORDER. SUNDAY...UPPER LOW LIFTS INTO MONTANA WITH SOUTHWEST FLOW AHEAD OF IT. SLIGHTLY COOLER TEMPERATURES IN THE 80S GENERALLY EXPECTED AS SFC HIGH SLOWLY MOVES INTO THE AREA. WILL CONTINUE WITH SLIGHT CHANCE/LOW CHANCE POPS ACROSS THE EASTERN 1/3 OF THE AREA WHERE FRONT IS EXPECTED. MONDAY...DRY WITH HIGHS IN THE UPPER 70S TO LOW 80S. TUESDAY...SMALL CHANCES FOR PRECIPITATION AS A WEATHER SYSTEM MOVES ACROSS THE AREA. HIGHS IN THE LOW TO MID 80S. WEDNESDAY...SLIGHTLY COOLER TEMPERATURES WITH AN INCREASING CHANCE FOR PRECIPITATION AS ANOTHER WEATHER SYSTEM MOVES DOWN FROM THE NORTH AND NORTHWEST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1145 AM MDT THU MAY 24 2012 VFR CONDITIONS ARE EXPECTED TO PREVAIL AT BOTH KGLD AND KMCK TERMINALS THROUGH LATE TONIGHT. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ACROSS THE AREA TONIGHT. BASED ON EXPECTED SCATTERED COVERAGE I INCLUDED VCTS AT BOTH TERMINALS AFTER 04-05Z. BRIEF MVFR CONDITIONS WILL BE POSSIBLE IF A STORM DIRECTLY IMPACTS ONE OF THE TERMINALS. MVFR CONDITIONS SHOULD PREVAIL AFTER 10-11Z AS GOOD BL MOISTURE ADVECTS NORTH AND EAST WITH EASTERLY FLOW DEVELOPING ACROSS THE AREA. THERE IS STILL A LOT OF SPREAD IN GUIDANCE ON FRONTAL TIMING FRIDAY...WITH NAM SLOWER AND HOLDING STRATUS/FOG ON LONGER. NAM/MET WOULD ALSO INDICATE SIGNIFICANTLY LOWER CIGS OVER BOTH TERMINALS. THIS IS THE OUTLIER...SO CONFIDENCE IS HIGHER THAT CONDITIONS SHOULD IMPROVE TO VFR BY MID MORNING OVER KGLD AND AROUND 18Z AT KMCK. && .FIRE WEATHER... ISSUED AT 245 AM MDT THU MAY 24 2012 CRITICAL FIRE WEATHER CONDITIONS REMAIN POSSIBLE SATURDAY AS SFC WINDS GUSTS OVER 45 MPH AND RH VALUES DROP WELL BELOW 20 PERCENT. QUESTION BECOMES GREEN-UP CONDITIONS AND IMPACT OF LAST NIGHT/THIS MORNINGS RAINFALL ACROSS PARTS OF THE AREA AND ONE HOUR FUELS. NO HIGHLITES ISSUED AT THIS TIME. && .CLIMATE... ISSUED AT 245 AM MDT THU MAY 24 2012 RECORD AND NEAR RECORD HIGH TEMPERATURES EXPECTED SATURDAY. GOODLAND.....97 IN 2006 HILL CITY....99 IN 1912 MCCOOK.......98 IN 1967 BURLINGTON...95 IN 1942 YUMA.........96 TRIBUNE......101 COLBY........98 && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...007 AVIATION...DR FIRE WEATHER...007 CLIMATE...007
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1237 PM CDT THU MAY 24 2012 ...UPDATED SYNOPSIS AND AVIATION DISCUSSION... .SYNOPSIS... ISSUED AT 1234 PM CDT THU MAY 24 2012 A 500MB UPPER LEVEL RIDGE/HIGH WAS LOCATED ACROSS THE EASTERN UNITED STATES WHILE AN UPPER LEVEL TROUGH EXTENDED FROM WESTERN CANADA INTO THE NORTHWESTERN UNITED STATES. ONE UPPER LEVEL JET STREAK WAS PLACED ACROSS COLORADO AND UTAH WITH AN UPPER LEVEL DISTURBANCE LOCATED IN EASTERN WYOMING. ANOTHER UPPER LEVEL JET WAS LOCATED ON THE SOUTHWEST SIDE OF A COLD (-26 TO -27C) UPPER LOW THAT WAS NEAR THE COAST OF BRITISH COLUMBIA. 500MB INDICATED 90 METER HEIGHT FALLS FROM THE NORTH PLATTE SOUNDING AT 12Z. A 700MB BAROCLINIC ZONE STRETCHED FROM SOUTHEAST COLORADO INTO SOUTHEAST NEBRASKA WITH THE ELEVATED MIX LAYER LOCATED ACROSS OKLAHOMA AND EASTERN KANSAS. A SURFACE COLD FRONT AT 12Z EXTENDED FROM PANHANDLE OF TEXAS ACROSS SOUTHWEST OKLAHOMA INTO SOUTHEAST KANSAS. ALONG AND EAST OF THIS FRONT SURFACE DEWPOINTS WERE IN THE MID-UPPER 60S AND 850MB DEWPOINT RANGED FROM 13 TO 16C. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 408 AM CDT THU MAY 24 2012 THE SHORTER TERM MODELS OF THE NAM AND THE HRRR NOW SHOW THERE WILL NOT BE ANY PRECIP IN OUR FORECAST AREA TODAY. THE COLD FRONT IS THROUGH OUR CWA, WITH A LOW PRESSURE SYSTEM POSITIONED OVER SOUTHEAST COLORADO. AN UPPER LEVEL DISTURBANCE IS MOVING EAST-NORTHEAST BUT TRAVELING THROUGH AREAS NORTH OF OUR COUNTY WARNING AREA, NORTHERN KANSAS AND NEBRASKA AND POINTS NORTHEASTWARD. THERE IS SOME CIRRUS AROUND AND THINK THE GRIDS WILL PRODUCE MOSTLY SUNNY CONDITIONS. WHEN THE FRONT FIRST WENT THROUGH, THE WINDS BEHIND THE FRONT QUICKLY PICKED UP INTO ADVISORY LEVELS, AND THUS A SHORT TERM WIND ADVISORY WAS ISSUED FOR THAT AREA WEST OF A DIGHTON TO MONTEZUMA LINE, AND ALSO NORTH OF A JOHNSON CITY TO MONTEZUMA LINE. AT THE TIME OF WRITING THIS SHORT TERM DISCUSSION, WINDS HAD FALLEN BACK TO LESS THAN ADVISORY CRITERIA AT ALL SITES EXCEPT HUGOTON AND SCOTT CITY. THIS WIND ADVISORY WILL EXPIRE AT 09Z, AND SHOULD NOT SHOW UP IN THE NEXT ZONE ISSUANCE. TEMPERATURES TODAY WILL BE COOLER THAN YESTERDAY`S NEAR CENTURY MARKS, DUE TO THE COLD FRONTAL PASSAGE AND HIGH CLOUDS. HIGHS TODAY SHOULD RANGE FROM THE MID 80S ALONG THE OKLAHOMA PANHANDLE TO THE UPPER 70S NORTH OF THE I-70 CORRIDOR. THE COLD FRONT MENTIONED ABOVE WILL COME BACK NORTH TONIGHT AS A WARM FRONT. JUST HOW FAST NORTH IT WILL MOVES IS HANDLED DIFFERENTLY BY THE MODELS. THE NAM MODEL BRINGS THE FRONT NORTH THE FASTEST, WITH THE GFS AND ECMWF MODELS SLOWER. BY THE TIME THE FRONT REACHES OUR NORTHERN COUNTIES OF ELLIS, TREGO, RUSH, NESS, LANE AND SCOTT BY 09Z, THERE COULD BE A FEW THUNDERSTORMS FORM IN THE ELEVATED UNSTABLE LAYERS OF THE ATMOSPHERE. I ONLY PLACED 20 POPS IN, AS THE TIMING OF THE FRONT IS STILL IN QUESTION. CLOUDS WILL BLANKET MOST OF SOUTHWESTERN KANSAS THURSDAY NIGHT, AND WINDS NEAR THE OKLAHOMA BORDER WILL BE SOUTH AT 10 TO 20 MPH BEHIND THE FRONT AND EASTERLY AT 10 TO 20 MPH NORTH OF THE FRONT. TEMPERATURES THURSDAY NIGHT WILL BE SOMEWHAT ELEVATED, ONLY FALLING TO THE MID 60S IN THE MEDICINE LODGE AND PRATT AREAS, INTO THE LOWER 60S FROM LIBERAL TO DODGE CITY TO LARNED, AND INTO THE MIDDLE 50S FROM SYRACUSE TO SCOTT CITY TO WAKEENEY. .LONG TERM...(FRIDAY THROUGH THURSDAY) ISSUED AT 359 AM CDT THU MAY 24 2012 A CHALLENGING FORECAST LIES AHEAD FOR THE COMING SEVERAL DAYS, AS A FEW OPPORTUNITIES FOR CONVECTION APPEAR POSSIBLE. BY FRIDAY MORNING, A WARM FRONT WILL BE LIFTING NORTHWARD THROUGH SOUTHWEST KANSAS. THE MODELS DIFFER SIGNIFICANTLY WITH THIS FRONT. THE GFS PRODUCES QPF AS EARLY AS OVERNIGHT THURSDAY HEADING INTO FRIDAY MORNING, AND REALLY INCREASING THE QPF AROUND THE 12Z TIMEFRAME. BY CONTRAST THE NAM AND ECMWF ARE MORE IN LINE WITH A DRY SOLUTION. THE CONVECTION PRODUCED IN THESE CASES ARE MORE IN LINE WITH THE EDGE OF A CAPPING LATER IN THE MID LEVELS THAT IS LOCATED ACROSS NORTHERN KANSAS. IN EITHER CASE; STRONG LOW LEVEL THETA-E ADVECTION AND ISENTROPIC LIFT IN THE MORNING, OR BREAKING THE CAP LATE IN THE DAY FARTHER NORTH, QUARTER TO GOLFBALL SIZED HAIL WOULD BE LIKELY. HOWEVER, THE MOST LIKELY EVENT IS PROBABLY ALONG THE LINES OF THE ECMWF AND NAM GIVEN THE WARM TEMPERATURES IN THE MID LEVELS OF 13 TO 14 DEGREES C. IF THE WARM AIR ALOFT IS STRONG ENOUGH OF A CAP ON FRIDAY, THE POTENTIAL FOR SEVERE CONVECTION MIGHT BE RELEGATED EVEN FARTHER NORTH INTO NORTH CENTRAL KANSAS AND NEBRASKA. SURFACE TEMPERATURES WILL EXCEED 95 DEGREES IN THIS WARM BOUNDARY LAYER AIR AND LIKELY HIT 100 DEGREES OR MORE IN THE RED HILLS REGION. IT IS UNKNOWN AT THIS TIME IF THE SMOKE FROM THE NEW MEXICO FIRES WILL PLAY A ROLE IN INHIBITING INSOLATION WHICH IN TURN COULD PREVENT TEMPERATURES FROM REACHING THE AFOREMENTIONED VALUES. BUT IT IS SOMETHING TO CONSIDER IN THE NEXT 24 OR SO HOURS. HEADING INTO THE WEEKEND, A CONSENSUS OF THE MODELS WOULD SEEM TO SUPPORT AT LEAST SOME POTENTIAL FOR DRYLINE TRIGGERED CONVECTION ACROSS CENTRAL KANSAS ON SATURDAY. HOWEVER, IT IS NOT CLEAR AT ALL JUST WHERE THE DRYLINE MIGHT BE LOCATED AT THIS TIME. GENERALLY ISOLATED DISCREET CONVECTION WITHIN AMPLE SHEAR FOR AT LEAST THE POTENTIAL FOR SUPERCELLS PRODUCING UP TO GOLFBALL SIZED HAIL. A MORE ORGANIZED SEVERE CONVECTIVE POTENTIAL COULD OCCUR ON SUNDAY. THE FORCING MECHANISMS FOR THIS POTENTIAL WILL BE AN ADVANCING UPPER TROUGH WITH A LARGE COLD POOL (COOLING TEMPERATURES ALOFT) AND A LEAD UPPER JET`S RIGHT REAR QUADRANT. THE GFS AND ECMWF BOTH APPEAR TO SUPPORT A TORNADIC SUPERCELL ENVIRONMENT SUNDAY AFTERNOON ALONG THE WARM FRONT-SURFACE LOW INTERSECTION. BEYOND THIS PERIOD, THE FORECAST APPEARS TO CREATE MORE UNCERTAINTY. THE OVERALL CONSENSUS APPEARS TO BE A FLATTENING OF THE UPPER FLOW AS THE UPPER JET LIFTS INTO THE UPPER MIDWEST THROUGH TUESDAY. THIS SHOULD, WITH TIME ALLOW DRIER AIR TO SETTLE OVER WESTERN KANSAS REDUCING THE ODDS OF THUNDERSTORMS. BEFORE THE ECMWF AND GFS BOTH TREND RAPIDLY TOWARD STRONG MOISTURE RETURN AND CONVECTION ONCE AGAIN BY AROUND DAY 7. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1234 PM CDT THU MAY 24 2012 WINDS THIS AFTERNOON WILL CONTINUE TO SUBSIDE AS A RIDGE OF HIGH PRESSURE AT THE SURFACE BUILDS ACROSS WESTERN KANSAS. TOWARDS EVENING AN EASTERLY WIND WILL DEVELOP AS SURFACE PRESSURES BEGIN TO FALL ALONG EASTERN COLORADO/NORTHEAST NEW MEXICO. ISENTROPIC LIFT AND MOISTURE WILL THEN BEGIN TO IMPROVE ACROSS WESTERN KANSAS EARLY TONIGHT AND BASED ON BUFR SOUNDINGS THE LOWER LEVELS WILL BEGIN TO SATURATE AFTER MIDNIGHT WITH MVFR CIGS DEVELOPING AFTER 09Z AT DDC AND GCK. CLOUD BASES APPEAR TO BE SLIGHTLY HIGHER AT HYS. BASED ON THE DEPTH OF THIS MOIST LAYER FROM THE NAM THESE LOW CLOUDS ARE EXPECTED TO ERODE TOWARDS LATE MORNING AS A SOUTHEAST/EAST WIND CONTINUES AT NEAR 15 KNOTS. && .PRELIMINARY POINT TEMPS/POPS... DDC 83 62 98 70 / 0 10 10 10 GCK 82 60 97 68 / 0 10 10 10 EHA 85 59 93 66 / 0 10 10 10 LBL 85 62 96 68 / 0 10 10 10 HYS 80 59 89 69 / 10 20 20 20 P28 85 67 96 72 / 0 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BURGERT SHORT TERM...BURKE LONG TERM...RUSSELL AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
142 PM EDT THU MAY 24 2012 .UPDATE... ISSUED AT 1148 AM EDT THU MAY 24 2012 ISSUED A WIND ADVISORY FOR THE REST OF CENTRAL AND ERN CWA AS WINDS WERE ALREADY GREATER THAN PREVIOUS FORECAST...AND A CORE OF 40-50KT 925MB WINDS WILL MOVE INTO THE CENTRAL AND ERN CWA AROUND 18Z. EXPECT GUSTS TO AROUND 45KTS TO BE ABLE TO MIX DOWN TO THE SFC THIS AFTERNOON. STILL WATCHING SEVERE THUNDERSTORM POTENTIAL THIS AFTERNOON/EVENING OVER MAINLY THE WESTERN HALF OF UPPER MI. WILL BE EXAMINING POPS/WX MORE CLOSELY FOR UPDATES IN THE NEXT COUPLE OF HOURS. && .SYNOPSIS... ISSUED AT 504 AM EDT THU MAY 24 2012 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW HI AMPLITUDE UPR RDG OVER THE NE CONUS/SE CANADA DOWNSTREAM OF DEEP UPR TROF IN THE ROCKIES. UNDER THE SW FLOW ALF BTWN THESE LARGER SCALE FEATURES...A SHRTWV/SFC LO LIFTING NEWD NEAR LK WINNIPEG WITH UPR DVGC IN RRQ OF SUPPORTING 100KT H3 JET MAX HAS CAUSED QUITE A BIT OF SHRA/TS IN MN MAINLY WITHIN AXIS OF DEEPER MSTR ON THE COLD SIDE OF SFC FNT OVER WRN LK SUP THAT IS ATTENDANT TO LK WINNIPEG LO. A FEW -SHRA/A LTG STRIKE OF TWO ARE JUST W OF IWD NEAR THE SFC COLD FNT LOCATION NOT FAR FM ASHLAND IN NW WI. TO THE E OVER MOST OF THE CWA...BONE DRY AIRMASS SHOWN ON THE 00Z GRB RAOB /PWAT 0.25 INCH WITH KINX -53/ IS BRINGING A TRANQUIL OVERNGT WITH JUST SOME SCT HI CLDS. THE APRCH OF ANOTHER STRONG SHRTWV ROTATING THRU THE WRN TROF IS CAUSING MORE SHRA/TS TO BREAK OUT IN NEBRASKA UNDER EXPANDING AREA OF COOLING CLD TOPS. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 504 AM EDT THU MAY 24 2012 MAIN FCST CONCERN DURING THIS TIME IS POTENTIAL FOR SVR WX LATE THIS EVNG ASSOCIATED WITH SHRTWV NOW ROUNDING THE BASE OF THE WRN TROF AND CAUSING EXPANDING AREA OF SHRA/TS AROUND NEBRASKA. TDAY...ALTHOUGH SOME OF THE SCT -SHRA NOW ALONG THE COLD FNT WL DRIFT INTO THE WRN ZNS EARLY THIS MRNG PER SLOWLY VEERING H85 FLOW TO SW AS SHOWN BY THE 00Z NAM...THE BULK OF THE RA NOW IN MN WL STAY W AND DIMINISH AS POCKET OF UPR DVGC IN RRQ OF JET MAX IN NW ONTARIO LIFTS TO THE NE. BUT WITH DRYNESS OF AIRMASS IN PLACE PER THE 00Z GRB RAOB AND HI AMPLITUDE RDG JUST TO THE E...THESE -SHRA SHOULD REMAIN OVER THE W AS THE SLOW MOVING COLD FNT STALLS WITH BACKING OF THE UPR FLOW ASSOCIATED WITH MOTION OF ROCKIES SHRTWV INTO THE PLAINS. THEN MOST OF THE DAY WILL FEATURE A GUSTY S WIND AS H85 WINDS INCRS TO 40-45KTS IN ADVANCE OF THE SHRTWV/DVLPG SFC LO IN THE PLAINS THAT IS FCST TO LIFT NEWD TO NOT FAR FM DLH BY 00Z. CONFINED CHC POPS TO THE W. DAYTIME HEATING/MIXING WL CAUSE WIND GUSTS TO AT LEAST APRCH ADVY CRITERIA WITH STEEP LLVL LAPSE RATES AS HI TEMPS SURGE INTO THE 80S AT SOME PLACES AWAY FM THE MODERATING INFLUENCE OF MAINLY LK MI. AFT COORDINATION WITH GRB...OPTED TO ISSUE WIND ADVY FOR MAINLY THE W HALF OF THE CWA AWAY FM THE MORE STABILIZED KEWEENAW PENINSULA TO ACCOUNT FOR DEEP MIXING...EXCEPTIONAL INTENSITY OF THE APRCHG DISTURBANCE/SFC LO PRES...AND GFS FCST H85/H925 S WINDS UP TO 60KTS/50KTS. GFS BUFKIT PROFILES INDICATE WINDS OF 35-40 KTS WL BE PRESENT IN MIXED LYR AT IWD. ALTHOUGH THE ARRIVAL OF HIER H95-9 SPECIFIC HUMIDITY IN THIS STRENGTHENING SLY FLOW WL KEEP MIN RH FM FALLING TO CRITICAL LVLS...THE GUSTY S WINDS WL STILL BE A CHALLENGE FOR THE PERSONNEL FIGHTING THE SENEY FIRE/OTHER WILDFIRES. MORE NMRS SHRA/TS ASSOCIATED WITH THE LO MOVING NEAR DLH MAY ARRIVE OVER THE FAR W IN THE 21Z-24Z TIME. TNGT...AS THE NEGATIVELY TILTED SHRTWV/SFC LO MOVE QUICKLY NE INTO ONTARIO...EXPECT A STRONG COLD FROPA ACRS THE CWA. VERY STRONG DYNAMICS THAT IMPACT MAINLY THE W HALF INCLUDE VIGOROUS DPVA/UPR DVGC IN THE LEFT EXIT OF SUPPORTING 130KT H3 JET MAX. ALTHOUGH FCST SDNGS DO NOT SHOW PARTICULARLY STEEP MID LVL LAPSE RATES...INVERTED V LOOK TO THE T/TD PROFILE IN THE SUB H8-85 LYR FOR IWD AT 00Z WITH EARLY EVNG FROPA THERE MAXIMIZING LLVL DESTABLIZATION AT PEAK HEATING TIME SUG THE POTENTIAL FOR DAMAGING WINDS WITH UNIDIRECTIONAL/SLOWLY VEERING POWERFUL FLOW THAT INCLUDES H7/H85 WINDS AS HI AS 60-70KTS/50-60KTS EVEN THOUGH THERE IS NOT A LOT OF MID LVL DRY AIR TO MAXIMIZE DCAPE. DESPITE THE STRONG WIND FIELDS...INVERTED V LLVL T/TD PROFILE AND LACK OF DIRECTIONAL SHEAR WOULD TEND TO MINIMIZE TORNADO THREAT. SINCE THE MID LVL LAPSE RATES ARE RELATIVELY WEAK AND LACK OF DRY MID LVL AIR RESULTS IN WBZ HGT IN THE 12.5-13.0K RANGE...THE LARGE HAIL THREAT DOES NOT APPEAR TOO HI. SINCE THE SHARPER DYNAMICS WL EXIT TO THE NE AND NOCTURNAL COOLING WL BEGIN TO HAVE AN IMPACT...EXPECT THE SHRA/TS CHCS AND SEVERE WX THREAT TO WANE AS THE FRONT MARCHES FARTHER E. VIGOROUS DRY SLOTTING/ARRIVAL OF LARGER SCALE QVECTOR DVGC IN THE WAKE OF THE FROPA WL CAUSE DIMINISHING POPS...BUT LINGERING LLVL MSTR MAY STILL CAUSE A FEW -SHRA IN THE UPSLOPE AREAS OF THE W THRU THE NGT. GIVEN STRENGTH OF THIS DISTURBANCE...CONCERNED W WINDS IN THE WAKE OF THE COLD FROPA WL REACH ADVY CRITERIA OVER MAINLY THE EXPOSED KEWEENAW PENINSULA AFT 06Z WITH W H925 WINDS INCRSG TO 40-50 KTS/VIGOROUS CAD THAT WL MAINTAIN STEEPER LLVL LAPSE RATES DESPITE SOME STABILIZATION OVER THE RELATIVELY COOL WATERS OF LK SUP/AND APRCH OF PRES RISE MAX OF 10-15MB/6HRS THAT WL ACCENTUATE ISALLOBARIC WIND COMPONENT NEARLY IN LINE WITH GRADIENT FLOW. FRI...WITH THE ARRIVAL OF DRIER AIR AND APRCH OF UPR RDG...EXPECT A DRY DAY. GUSTY WINDS WL PERSIST WITH DAYTIME HEATING/MIXING EVEN THOUGH THE PRES GRADIENT IS FCST TO SLOWLY SLACKEN. WITH H85 TEMPS TOPPING OUT IN THE 8-10C RANGE...MIXING TO H75 ON GFS/NAM FCST SDNGS YIELD HI TEMPS IN THE 75-80 RANGE WITH DOWNSLOPING FLOW AWAY FM LK MODERATION IN LLVL WNW FLOW. .LONG TERM...(AFTER MIDNIGHT FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 621 AM EDT THU MAY 24 2012 EXPECT WINDS TO DIMINISH AND BECOME NEARLY CALM FRIDAY NIGHT...AS TEMPS FALL INTO THE 40S. WENT WITH THE DRIER NON-NAM SOLUTION FOR MUCH OF THIS PERIOD...AS THE 24/00Z NAM WAS VERY OPTIMISTIC WITH ITS PRINTOUT OF PRECIP. OTHER CHANGES INCLUDED A WARMING OF TEMPS UP A COUPLE OF DEGREES FOR SATURDAY /COOLEST N NEAR LAKE SUPERIOR/...WITH A GENERALLY SLOWER ONSET OF PRECIP. THUNDERSTORMS SHOULD STAY ALONG THE WI BORDER THROUGH THE AFTERNOON HOURS. THESE THUNDERSTORMS WILL PUSH NORTHWARD...THANKS TO THE WARM FRONT. TEMPS SUNDAY WILL POP BACK INTO THE 70S WEST SUNDAY. WHILE WE DO HAVE A FCST FOR HIGH CHANCE POPS THROUGH MUCH OF THE DAY...THE BEST CHANCE WILL MORE THAN LIKELY BE THROUGH 18Z...BEFORE MUCH OF THE PRECIPITATION MOVES N ACROSS LAKE SUPERIOR. THUNDERSTORMS WILL END W TO E MONDAY AS THE SFC LOW PUSHES ACROSS AND EXITS E OF THE AREA. WHILE THERE ARE SILL SOME SIGNIFICANT DIFFERENCES BETWEEN THE MODELS...THEY ARE IN BETTER AGREEMENT FOR THIS PERIOD THAN 24 HRS AGO. THE SFC TROUGH WILL LINGER ACROSS THE CWA THROUGH TUESDAY WITH LOW CHANCE/SLIGHT CHANCE POPS LINGERING THROUGH THE END OF THE FCST PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 141 PM EDT THU MAY 24 2012 CHALLENGING FORECAST THIS AFTERNOON WITH THUNDERSTORMS AND GUSTY WINDS ACROSS UPPER MICHIGAN. RADAR SHOWS SHOWERS AND THUNDERSTORMS TIED TO A FRONTAL BOUNDARY EXTENDING ACROSS WESTERN LAKE SUPERIOR. THIS BOUNDARY IS ASSOCIATED WITH A LOW PRESSURE SYSTEM CENTERED OVER CENTRAL IOWA AND SOUTHERN MN. AS THIS SYSTEM MOVES NORTHWARD SHOWERS AND THUNDERSTORMS WILL SPREAD EASTWARD INTO KIWD AND KCMX LATE THIS AFTERNOON...AND EVENTUALLY INTO KSAW OVERNIGHT. AS THE PRESSURE GRADIENT GRADUALLY TIGHTENS WITH THE APPROACH OF THE SYSTEM WINDS WILL GUST TO AS MUCH AS 35 KNOTS THROUGHOUT THE AFTERNOON TODAY AND EVEN OVERNIGHT. SHOWERS AND THUNDERSTORMS THAT WILL DEVELOP HAVE THE POTENTIAL TO BRING EVEN HIGHER GUSTS...POSSIBLY SEVERE...TO THE SURFACE. ONCE THE SYSTEM PASSES TO THE NORTHEAST OF LAKE SUPERIOR OVERNIGHT WINDS WILL BECOME MORE WESTERLY. GUSTS ACROSS THE KEWEENAW/AT KCMX/ FRIDAY MORNING COULD REACH AS HIGH AS 40 KNOTS...AND SHOULD WEAKEN THROUGH LATE AFTERNOON. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 621 AM EDT THU MAY 24 2012 ALTHOUGH S WINDS AT SOME OF THE HIGHER PLATFORMS LIKE STANNARD ROCK WILL PUSH 30-35 KTS INTO TONIGHT IN ADVANCE OF A DEEP LO PRES/STRONG COLD FRONT MOVING THRU WESTERN LK SUP THIS EVENING...HIGHER OVER WATER STABILITY WILL LIMIT THE MIXING OF THE STRONGER WINDS TO NEAR THE SURFACE. ONCE THE FRONT PASSES BY TONIGHT AND THE WIND SHIFTS TO THE W...EXPECT THE STRONGER WINDS TO MIX CLOSER TO THE SURFACE WITH THE ARRIVAL OF COOLER AIR. ALTHOUGH THERE IS SOME UNCERTAINTY HOW MUCH OF THE STRONGER FLOW WILL MAKE IT TO THE SURFACE...OPTED TO ISSUE GALE WATCH LATE TONIGHT THRU FRI MORNING FOR THE AREA BETWEEN ISLE ROYALE AND THE KEWEENAW WHERE TERRAIN WILL ENHANCE THE EXPECTED WSW FLOW. WINDS WILL DIMINISH ON FRI AFTERNOON WITH WEAKENING PRES GRADIENT. HIGH PRESSURE ACROSS CENTRAL CANADA FRIDAY NIGHT WILL CROSS ONTARIO AND LAKE SUPERIOR SATURDAY...BEFORE SETTLING ACROSS HUDSON BAY ON SUNDAY. LOW PRESSURE OVER THE NORTHERN PLAINS SUNDAY WILL FILL ACROSS THE UPPER GREAT LAKES MONDAY INTO MONDAY NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WIND ADVISORY UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR MIZ002- 004>007-009>014-084-085. LAKE SUPERIOR... GALE WATCH FROM LATE TONIGHT THROUGH FRIDAY MORNING FOR LSZ263- 264-266. LAKE MICHIGAN... NONE. && $$ UPDATE...TITUS SYNOPSIS...KC SHORT TERM...KC LONG TERM...KF AVIATION...MCB MARINE...KF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
403 PM EDT THU MAY 24 2012 .SYNOPSIS... THE COMBINATION OF BUILDING RIDGE ALOFT AND WEAK SURFACE HIGH PRESSURE WILL RESULT IN PARTLY CLOUDY SKIES TONIGHT WITH SOME AREAS OF PATCHY FOG. ON FRIDAY...SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS THE SAINT LAWRENCE VALLEY IN THE LATE AFTERNOON HOURS AND SPREAD EAST INTO VERMONT DURING THE EVENING. SOME STORMS COULD BE STRONG WITH GUSTY WINDS...SMALL HAIL...AND BRIEF HEAVY DOWNPOURS....ESPECIALLY ACROSS NORTHERN NEW YORK. SLIGHTLY COOLER AND DRIER AIR ARRIVES FOR SATURDAY INTO SUNDAY. && .NEAR TERM /THROUGH FRIDAY/... AS OF 400 PM EDT THURSDAY...FCST FOCUS WL BE AREAL COVERAGE OF CLOUDS/FOG AGAIN TONIGHT...FOLLOWED BY CHCS FOR CONVECTION LATE FRIDAY. WATER VAPOR SHOWS LARGE AREA OF SUBSIDENCE ACRS OUR CWA THIS AFTN ASSOCIATED WITH BUILDING MID/UPPER LVL RIDGE. MEANWHILE...MID/UPPER LVL TROF AND S/W ENERGY IS COMBINING WITH A SFC COLD FRNT TO PRODUCE AREAS OF CONVECTION UPSTREAM ACRS THE NORTHERN PLAINS/WESTERN GREAT LAKES. THIS ENERGY/MOISTURE AND SFC BOUNDARY WL BE APPROACHING OUR WESTERN FA BTWN 18Z-21Z FRIDAY...WITH INCREASING CHCS FOR STORMS. RAP AND LOCAL 4KM SOUNDINGS ONCE AGAIN SHOW PLENTY OF SFC TO 850MB RH DEVELOPING LATE THIS EVENING ACRS CENTRAL/EASTERN VT ASSOCIATED WITH MOIST SE FLW. THIS WL CREATE AREAS OF LOW CLOUDS AND MIST...NOT THINKING AS MUCH FOG TONIGHT...DUE TO BL WINDS OF 8 TO 12 KNTS. ALSO...AREAS ACRS CENTRAL/EASTERN VT AND NORTHERN DACKS THAT RECEIVE ISOLATED RAIN THIS AFTN...WL HAVE A BETTER CHC FOR FOG TONIGHT. OTHERWISE...BL STAYS MIXED OVERNIGHT ACRS THE CPV/SLV AND SFC DWPTS IN THE U50S/L60S WL RESULT IN LOWS BTWN 60 AND 65F...WITH MAINLY 50S IN THE COOLER MTN VALLEYS. ON FRIDAY...POTENT S/W ENERGY AND SFC COLD FRNT WL APPROACH OUR WESTERN CWA BTWN 18Z-21Z. LEFTOVER MORNING CLOUDS SHOULD DISSIPATE BY 15Z...WITH SFC TEMPS WARMING INTO THE U70S TO M80S AHEAD OF BOUNDARY. THIS WL CREATE AN AXIS OF INSTABILITY WITH CAPE VALUES NEAR 1400 J/KG...LIS AROUND -3C...AND TT`S NEAR 50. IN ADDITION...0 TO 3KM AND 0 TO 6KM SHEAR INCREASES ACRS OUR WESTERN CWA ON FRIDAY AFTN...AS JET ENERGY FROM MID/UPPER LVL TROF APPROACHES. BOTH THE NAM/GFS SHOW 0 TO 3KM VALUES AROUND 30 KNTS AND 0 TO 6KM SHEAR VALUES NEAR 40 KNOTS. HOWEVER...RIBBON OF DEEP LAYER MOISTURE WL BE WEAKENING ACRS OUR CWA...AS SYSTEM ENCOUNTERS STRONG MID/UPPER LVL RIDGE AND BEST ULVL DYNAMICS WL BE SHIFTING TWD HUDSON BAY...INSTEAD OF DIGGING SE ACRS THE EASTERN GREAT LAKES. THESE FACTORS WL LIMIT AREAL COVERAGE/INTENSITY OF CONVECTION...ALONG WITH TIMING OF SFC BOUNDARY AFT 00Z FOR CPV/VT...WITH INSTABILITY PARAMETERS WEAKENING. THE BEST CHC FOR A STRONG STORM OR TWO WL BE NORTHERN NEW YORK WITH DIME SIZE HAIL AND WIND GUST TO 50 MPH POSSIBLE BTWN 18Z-22Z. OTHERWISE...BROKEN LINE OF SHOWERS WITH EMBEDDED STORMS WL ENTER THE CPV BY 00Z AND BE THRU VT BY 06Z SATURDAY. PROGGED 85H TEMPS NEAR 14C AND 925MB TEMPS AROUND 18C SUPPORT HIGHS BACK INTO THE M70S MTNS/NEK TO L/M 80S WARMER VALLEYS. FINALLY...SOUNDINGS SHOW GUSTY SOUTH TO SOUTHWEST WINDS BTWN 15 AND 25 MPH WITH GUSTS TO 30 MPH. && .SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/... AS OF 400 PM EDT THURSDAY...SFC COLD FRNT SWEEPS ACRS OUR CWA ON FRIDAY NIGHT...WHILE HIGH PRES BUILDS INTO OUR FA BY SATURDAY. LLVL CAA WL DEVELOP BEHIND SFC BOUNDARY FRIDAY NIGHT INTO SATURDAY WITH BEST RH PROFILES MOVING EAST OF OUR CWA BY 12Z SAT. THE COMBINATION OF BL WINDS AND CAA WL LIMIT AREAL COVERAGE OF FOG/BR ON SATURDAY MORNING...BUT FEEL A FEW OF THE SHELTERED VALLEYS WL SEE SOME FOG. TEMPS WL COOL INTO THE 40S MTN VALLEYS TO M/U50S CPV/SLV ON SAT MORNING. HIGH PRES AND SUBSIDENCE ALOFT WL RESULT IN PLENTY OF SUN ON SATURDAY WITH SOME FAIR WX CUMULUS POSSIBLE ACRS THE MTNS AS CONVECTIVE TEMPS ARE REACHED. PROGGED 85H TEMPS COOL BTWN 6-8C ON SATURDAY...SUPPORTING HIGHS ONLY IN THE 60S MTNS TO L/M70S VALLEYS. SATURDAY NIGHT...AREAS OF FOG WL BE POSSIBLE...ALONG WITH SOME HIGH LVL DEBRIS CLOUDS ACRS NORTHERN NY FROM UPSTREAM CONVECTION. WL KEEP FCST DRY WITH TEMPS COOLING BACK INTO THE 40S MTNS TO M/U50S CPV/SLV. NORTHERLY WINDS SHOULD BECOME LIGHT AND VARIABLE OVERNIGHT. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 350 PM EDT THURSDAY...GUIDANCE POINTS TO A RATHER ACTIVE PERIOD OF WEATHER FOR LATE MEMORIAL DAY WEEKEND INTO TUESDAY. THE POTENTIAL EXISTS FOR ONE OR SEVERAL ROUNDS OF SHOWERS OR THUNDERSTORMS DURING THIS PERIOD...ACCOMPANIED BY ABOVE-AVERAGE TEMPERATURES AND RATHER HUMID WEATHER. CONVECTIVE SCENARIO WILL DEPEND ON THUNDERSTORMS FROM PREVIOUS DAYS...SO IT IS DIFFICULT TO PINPOINT SPECIFICS AT THIS TIME. IT APPEARS THAT MONDAY AND/OR TUESDAY OFFER THE BEST POTENTIAL FOR THUNDER AS SHOWALTER INDICES DROP BELOW ZERO (ESPECIALLY ON MONDAY) WITH RATHER STRONG UPPER- LEVEL FLOW ALOFT. REGARDING TEMPERATURES...850MB TEMPERATURES STEADILY RISE FROM 12-13 C ON SUNDAY TO AROUND 14-16 C ON TUESDAY...LEADING TO HIGHS RISING FROM THE UPPER 70S TO THE LOWER/MID 80S WITH LOWS IN THE UPPER 50S TO THE LOWER/MID 60S. TEMPERATURES ON MONDAY APPEAR PARTICULARLY TRICKY EAST OF THE GREENS GIVEN FORECAST COOLER THICKNESSES THERE...SO HAVE KEPT HIGHS IN THE MID 70S IN THE NORTHEAST KINGDOM ON MONDAY. COLD FRONT LOOKS TO SWEEP ACROSS THE NORTH COUNTRY LATER TUESDAY...BRINGING WITH IT NOTICEABLY COOLER AND DRIER WEATHER TO THE REGION FOR WEDNESDAY INTO THE REMAINDER OF THE EXTENDED. && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... THROUGH 18Z FRIDAY...MOIST SOUTHEAST FLOW ALONG AND EAST OF THE GREENS BROUGHT SOME LOWER MVFR CEILINGS AT MPV THIS MORNING...THOUGH THESE HAVE BEGUN TO LIFT BY EARLY AFTERNOON. CURRENT SKIES RANGE FROM BKN/OVC VFR ACROSS MPV TO FEW/SCT VFR FOR THE REMAINDER OF THE TERMINALS. AFTERNOON MIXING IN THE PARTLY CLOUDY SKIES HAS RESULTED IN SOUTHERLY GUSTS TO AROUND 20KTS THIS AFTERNOON...AND THESE WILL CONTINUE THROUGH 23Z/00Z BEFORE BOUNDARY LAYER STABILIZES. THERE COULD BE A STRAY SHOWER OR PERHAPS A THUNDERSHOWER AT RUT THIS AFTERNOON WITH SOME INSTABILITY IN PLACE BUT NOT MUCH OF A TRIGGER...SO LEFT OUT FOR NOW. EXPECTING MAINLY VFR FOR TONIGHT THOUGH SOME 3SM BR WITH ASSOCIATED MVFR/IFR CEILINGS AT MPV AND SLK. DESPITE FAIRLY LIGHT WINDS TONIGHT THINK THAT THERE WILL BE ENOUGH TURBULENT MIXING TO LIMIT FOG FORMATION...THOUGH MIST LOOKS POSSIBLE. ANY LINGERING LOWER CEILINGS LIFT BY 12-14Z FRIDAY BRINGING VFR CEILINGS AND AFTERNOON SOUTHERLY GUSTS TO AROUND 20KTS. SURFACE TROUGH WILL APPROACH FROM THE WEST LATE IN THE TAF PERIOD...WHICH MAY TRIGGER SOME SHOWERS OR THUNDERSTORMS. THIS WILL BE MONITORED...THOUGH FEEL AT THIS TIME THAT ANY SHOWERS/STORMS WILL HOLD OFF UNTIL AFTER 18Z FRIDAY. OUTLOOK 18Z FRIDAY THROUGH MONDAY... 18Z FRIDAY - 06Z SATURDAY...VFR WITH PERIODS MVFR/IFR IN SCATTERED SHOWERS/STORMS AS COLD FRONT TRAVERSES THE REGION. 06Z SATURDAY - 12Z SUNDAY...VFR UNDER HIGH PRESSURE. POSSIBLE EVENING FOG/MIST AT MPV/SLK WITH IFR CEILINGS/VISIBILITIES. 12Z SUNDAY - 12Z MONDAY...VFR DEGRADING TO MVFR IN SHOWERS/POSSIBLE THUNDER LATER SUNDAY/SUNDAY NIGHT AS WARM FRONT MOVES NORTHWARD. 12Z MONDAY - 00Z TUESDAY...MAINLY VFR THOUGH CAN`T RULE OUT A SHOWER OR THUNDERSTORM MONDAY AFTERNOON. && .MARINE... A LAKE WIND ADVISORY IS NOW IN EFFECT THIS AFTERNOON INTO TONIGHT FOR LAKE CHAMPLAIN. SOUTH WINDS AT COLCHESTER REEF LATE THIS MORNING HAVE INCREASED TO NEAR 20 KNOTS...AND LOCAL BTV WRF MODELS SHOW SOUTHERLY FLOW INCREASING TO AROUND 25 KNOTS THIS AFTERNOON. EXPECT SOUTH WINDS TO BE IN THE 15 TO 25 KNOT RANGE WITH 2 FOOT WAVES ACROSS THE BROAD LAKE. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...TABER NEAR TERM...TABER SHORT TERM...TABER LONG TERM...LOCONTO AVIATION...LOCONTO MARINE...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
350 PM EDT THU MAY 24 2012 .SYNOPSIS... DEPARTING HIGH PRESSURE WILL BRING SOUTHERLY FLOW AND A CHANCE FOR UPSLOPE RAIN SHOWERS...MAINLY OVER THE HIGH TERRAIN TODAY. A BETTER CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS WILL ARRIVE LATE FRIDAY INTO FRIDAY NIGHT ASSOCIATED WITH A SURFACE COLD FRONT. SLIGHTLY COOLER AND DRIER CONDITIONS WILL PREVAIL FOR THE UPCOMING HOLIDAY WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 114 PM EDT THURSDAY...NO SIGNIFICANT CHANGES TO CRNT FCST WITH TEMPS WARMING INTO THE M70S SOUTHERN VT TO M80S IN THE SLV. THIS SFC HEATING HAS CREATED CAPE VALUES BTWN 1200 AND 1600 J/KG...BUT WATER VAPOR SHOWS BUILDING RIDGE AND STRONG AREA OF SUBSIDENCE ACRS OUR CWA. THIS WL RESULT IN LIMITED AREAL COVERAGE OF CONVECTION THIS AFTN...WITH BEST CHC ALONG THE SPINE OF THE GREEN MTNS AND ACRS PARTS OF NORTHERN NY. WL CONT TO MENTION SCHC TO CHC POPS ACRS THESE REGIONS. FCST IN GREAT SHAPE THIS MORNING WITH ONLY MINOR CHANGES NEEDED. VIS SATL PIC SHOWS LOW CLOUDS SLOWLY DISSIPATING ACRS EASTERN/CENTRAL VT AND PARTS OF THE DACKS. EXPECT AS SFC HEATING CONTS THESE CLOUDS WL DEVELOP INTO A SCATTERED/BROKEN CUMULUS/TOWERING CUMULUS DECK. RAP AND LOCAL BTV 4KM SHOWS SOME INSTABILITY DEVELOPING THIS AFTN AS SFC TEMPS WARM INTO THE U70S TO M80S...WITH CAPE VALUES AROUND 1000 J/KG AND LI VALUES NEAR -3C. HOWEVER...WATER VAPOR SHOWS LARGE AREA OF SUBSIDENCE AND ASSOCIATED DEEP DRY LAYER WITH BUILDING MID/UPPER LVL RIDGE ACRS OUR REGION. THIS WL LIMIT AREAL COVERAGE OF CONVECTION THIS AFTN...THINKING JUST A SCHC DACKS/SLV AND CENTRAL/EASTERN VT ZNS...WITH LOW CHC POPS NEAR KILLINGTON. MOST OF CWA WL BE RAINFREE THIS AFTN...WITH TEMPS IN THE M80S SLV TO L80S CPV TO M/U 70S MTNS. PREVIOUS DISCUSSION FOLLOWS...FOG WILL DISSIPATE THIS MORNING WITH CLOUDS MOVING IN FROM THE SOUTH EAST AS DEPARTING HIGH PRESSURE BRINGS SOUTHERLY TO SOUTHEASTERLY FLOW OVER THE REGION. THIS WILL ALLOW MOISTURE FROM YESTERDAYS FRONT TO SURGE NORTHWARD. A WEAK UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE FORECAST AREA TODAY. THIS FEATURE COMBINED WITH SOUTHEASTERLY UPSLOPE FLOW WILL BE ENOUGH CONVERGENCE TO DEVELOP FEW TO SCATTERED SHOWERS AND SLIGHT CHANCE FOR THUNDERSTORMS OVER THE HIGHER TERRAIN. BEST CHC FOR SHOWERS/STORMS WILL BE ACROSS EASTERN/CENTRAL VT GREEN MTNS AND HIGHER TERRAIN OF THE ADIRONDACKS. NAM AND GFS INDICATE AREAS OF OVER 1000J/KG THIS AFTERNOON. LACK OF SHEAR WILL KEEP ANY CONVECTIVE ACTIVITY SUB-SEVERE. WINDS MAINLY OUT OF THE SOUTH WILL CHANNEL UP THE CHAMPLAIN VALLEY...WITH SPEEDS OF 15-25 KTS OVER LAKE CHAMPLAIN AND OVER THE MTNS DURING THE DAY. 850HPA TEMPERATURES WILL WARM INTO THE MID TEENS OVER SOUTHERN VT AND UPPER TEENS IN NORTHERN NY. INCREASING CLOUDS WILL KEEP SFC TEMPS FROM REACHING FULL HEATING POTENTIAL OVER MOST OF VT. MAX TEMPS IN THE UPPER 70S TO AROUND 80 IN THE VALLEYS AND MID 60S TO LOW 70S OVER THE HIGHER TERRAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... AS OF 455 AM EDT THURSDAY...AS THE SUN SETS...INSTABILITY AND THEREFORE SHOWERS WILL DISSIPATE THIS EVENING. CLOUDS WILL CONTINUE TO INCREASE AS MOISTURE CONTINUES TO FILTER IN FROM THE SOUTHERLY FLOW. OVERNIGHT MIN TEMPS WILL BE IN THE LOW 60S IN THE VALLEYS AND REACHING THE MID 40S IN THE HIGHER TERRAIN. A COLD FRONT WILL APPROACH FROM THE GREAT LAKES REGION ON FRIDAY. GFS SLIGHTLY FASTER SOLUTION WITH BEST DEFORMATION OVER WESTERN NY BY 18Z. NAM A FEW HOURS SLOWER...BUT BOTH MODELS SHOW DEFORMATION WASHING OUT OVER EASTERN NY/SOUTHERN VT FRIDAY EVENING INTO SATURDAY MORNING. THIS COLD FRONT WILL BE ACCOMPANIED BY A MID LEVEL JET ENTRANCE REGION AT 850MB AND 700MB IN SOUTHEASTERN ONTARIO STRETCHING NORTHEAST INTO QUEBEC. CAN EXPECT SHOWERS AND THUNDERSTORMS TO AHEAD AND ACCOMPANYING THE COLD FRONT AS SOUTHERLY FLOW AHEAD OF THE FRONT CONTINUES TO BRING WARM MOIST AIR INTO THE REGION...AS NOTED BY SFC DEWPOINTS IN THE 60S. AS AN UPPER LEVEL TROF APPROACHES THE NORTHEAST...WIND SHEAR WILL INCREASE WITH BEST VALUES BETWEEN 25-30 KNOTS OF 0-3KM SHEAR AND 30-35 KTS OF 0-6 KM SHEAR. THIS MODEST SHEAR COMBINED WITH CAPE VALUES BETWEEN 1000 AND 2000 J/KG SUPPORT SCATTERED CONVECTION ALONG THE BOUNDARY WITH A FEW STRONGER STORMS. NOT ANTICIPATING A WIDESPREAD SEVERE WEATHER EVENT...BUT A FEW STRONGER STORMS WITH GUSTY WINDS AND DIME SIZE HAIL WILL BE POSSIBLE. SHOWERS AND THUNDERSTORM WILL CONTINUE INTO FRIDAY EVENING BEFORE THE FRONT MOVES THROUGH THE EASTERN EDGE OF THE FORECAST AREA AFTER MIDNIGHT. SATURDAY WILL SEE DRIER CONDITIONS BEHIND THE FRONT AS HIGH PRESSURE BUILDS IN OVER EASTERN ONTARIO/WESTERN QUEBEC. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 350 PM EDT THURSDAY...GUIDANCE POINTS TO A RATHER ACTIVE PERIOD OF WEATHER FOR LATE MEMORIAL DAY WEEKEND INTO TUESDAY. THE POTENTIAL EXISTS FOR ONE OR SEVERAL ROUNDS OF SHOWERS OR THUNDERSTORMS DURING THIS PERIOD...ACCOMPANIED BY ABOVE-AVERAGE TEMPERATURES AND RATHER HUMID WEATHER. CONVECTIVE SCENARIO WILL DEPEND ON THUNDERSTORMS FROM PREVIOUS DAYS...SO IT IS DIFFICULT TO PINPOINT SPECIFICS AT THIS TIME. IT APPEARS THAT MONDAY AND/OR TUESDAY OFFER THE BEST POTENTIAL FOR THUNDER AS SHOWALTER INDICES DROP BELOW ZERO (ESPECIALLY ON MONDAY) WITH RATHER STRONG UPPER- LEVEL FLOW ALOFT. REGARDING TEMPERATURES...850MB TEMPERATURES STEADILY RISE FROM 12-13 C ON SUNDAY TO AROUND 14-16 C ON TUESDAY...LEADING TO HIGHS RISING FROM THE UPPER 70S TO THE LOWER/MID 80S WITH LOWS IN THE UPPER 50S TO THE LOWER/MID 60S. TEMPERATURES ON MONDAY APPEAR PARTICULARLY TRICKY EAST OF THE GREENS GIVEN FORECAST COOLER THICKNESSES THERE...SO HAVE KEPT HIGHS IN THE MID 70S IN THE NORTHEAST KINGDOM ON MONDAY. COLD FRONT LOOKS TO SWEEP ACROSS THE NORTH COUNTRY LATER TUESDAY...BRINGING WITH IT NOTICEABLY COOLER AND DRIER WEATHER TO THE REGION FOR WEDNESDAY INTO THE REMAINDER OF THE EXTENDED. && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... THROUGH 18Z FRIDAY...MOIST SOUTHEAST FLOW ALONG AND EAST OF THE GREENS BROUGHT SOME LOWER MVFR CEILINGS AT MPV THIS MORNING...THOUGH THESE HAVE BEGUN TO LIFT BY EARLY AFTERNOON. CURRENT SKIES RANGE FROM BKN/OVC VFR ACROSS MPV TO FEW/SCT VFR FOR THE REMAINDER OF THE TERMINALS. AFTERNOON MIXING IN THE PARTLY CLOUDY SKIES HAS RESULTED IN SOUTHERLY GUSTS TO AROUND 20KTS THIS AFTERNOON...AND THESE WILL CONTINUE THROUGH 23Z/00Z BEFORE BOUNDARY LAYER STABILIZES. THERE COULD BE A STRAY SHOWER OR PERHAPS A THUNDERSHOWER AT RUT THIS AFTERNOON WITH SOME INSTABILITY IN PLACE BUT NOT MUCH OF A TRIGGER...SO LEFT OUT FOR NOW. EXPECTING MAINLY VFR FOR TONIGHT THOUGH SOME 3SM BR WITH ASSOCIATED MVFR/IFR CEILINGS AT MPV AND SLK. DESPITE FAIRLY LIGHT WINDS TONIGHT THINK THAT THERE WILL BE ENOUGH TURBULENT MIXING TO LIMIT FOG FORMATION...THOUGH MIST LOOKS POSSIBLE. ANY LINGERING LOWER CEILINGS LIFT BY 12-14Z FRIDAY BRINGING VFR CEILINGS AND AFTERNOON SOUTHERLY GUSTS TO AROUND 20KTS. SURFACE TROUGH WILL APPROACH FROM THE WEST LATE IN THE TAF PERIOD...WHICH MAY TRIGGER SOME SHOWERS OR THUNDERSTORMS. THIS WILL BE MONITORED...THOUGH FEEL AT THIS TIME THAT ANY SHOWERS/STORMS WILL HOLD OFF UNTIL AFTER 18Z FRIDAY. OUTLOOK 18Z FRIDAY THROUGH MONDAY... 18Z FRIDAY - 06Z SATURDAY...VFR WITH PERIODS MVFR/IFR IN SCATTERED SHOWERS/STORMS AS COLD FRONT TRAVERSES THE REGION. 06Z SATURDAY - 12Z SUNDAY...VFR UNDER HIGH PRESSURE. POSSIBLE EVENING FOG/MIST AT MPV/SLK WITH IFR CEILINGS/VISIBILITIES. 12Z SUNDAY - 12Z MONDAY...VFR DEGRADING TO MVFR IN SHOWERS/POSSIBLE THUNDER LATER SUNDAY/SUNDAY NIGHT AS WARM FRONT MOVES NORTHWARD. 12Z MONDAY - 00Z TUESDAY...MAINLY VFR THOUGH CAN`T RULE OUT A SHOWER OR THUNDERSTORM MONDAY AFTERNOON. && .MARINE... A LAKE WIND ADVISORY IS NOW IN EFFECT THIS AFTERNOON INTO TONIGHT FOR LAKE CHAMPLAIN. SOUTH WINDS AT COLCHESTER REEF LATE THIS MORNING HAVE INCREASED TO NEAR 20 KNOTS...AND LOCAL BTV WRF MODELS SHOW SOUTHERLY FLOW INCREASING TO AROUND 25 KNOTS THIS AFTERNOON. EXPECT SOUTH WINDS TO BE IN THE 15 TO 25 KNOT RANGE WITH 2 FOOT WAVES ACROSS THE BROAD LAKE. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...KGM/TABER NEAR TERM...KGM/TABER SHORT TERM...KGM LONG TERM...LOCONTO AVIATION...LOCONTO MARINE...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
348 PM EDT THU MAY 24 2012 .SYNOPSIS... DEPARTING HIGH PRESSURE WILL BRING SOUTHERLY FLOW AND A CHANCE FOR UPSLOPE RAIN SHOWERS...MAINLY OVER THE HIGH TERRAIN TODAY. A BETTER CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS WILL ARRIVE LATE FRIDAY INTO FRIDAY NIGHT ASSOCIATED WITH A SURFACE COLD FRONT. SLIGHTLY COOLER AND DRIER CONDITIONS WILL PREVAIL FOR THE UPCOMING HOLIDAY WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 114 PM EDT THURSDAY...NO SIGNIFICANT CHANGES TO CRNT FCST WITH TEMPS WARMING INTO THE M70S SOUTHERN VT TO M80S IN THE SLV. THIS SFC HEATING HAS CREATED CAPE VALUES BTWN 1200 AND 1600 J/KG...BUT WATER VAPOR SHOWS BUILDING RIDGE AND STRONG AREA OF SUBSIDENCE ACRS OUR CWA. THIS WL RESULT IN LIMITED AREAL COVERAGE OF CONVECTION THIS AFTN...WITH BEST CHC ALONG THE SPINE OF THE GREEN MTNS AND ACRS PARTS OF NORTHERN NY. WL CONT TO MENTION SCHC TO CHC POPS ACRS THESE REGIONS. FCST IN GREAT SHAPE THIS MORNING WITH ONLY MINOR CHANGES NEEDED. VIS SATL PIC SHOWS LOW CLOUDS SLOWLY DISSIPATING ACRS EASTERN/CENTRAL VT AND PARTS OF THE DACKS. EXPECT AS SFC HEATING CONTS THESE CLOUDS WL DEVELOP INTO A SCATTERED/BROKEN CUMULUS/TOWERING CUMULUS DECK. RAP AND LOCAL BTV 4KM SHOWS SOME INSTABILITY DEVELOPING THIS AFTN AS SFC TEMPS WARM INTO THE U70S TO M80S...WITH CAPE VALUES AROUND 1000 J/KG AND LI VALUES NEAR -3C. HOWEVER...WATER VAPOR SHOWS LARGE AREA OF SUBSIDENCE AND ASSOCIATED DEEP DRY LAYER WITH BUILDING MID/UPPER LVL RIDGE ACRS OUR REGION. THIS WL LIMIT AREAL COVERAGE OF CONVECTION THIS AFTN...THINKING JUST A SCHC DACKS/SLV AND CENTRAL/EASTERN VT ZNS...WITH LOW CHC POPS NEAR KILLINGTON. MOST OF CWA WL BE RAINFREE THIS AFTN...WITH TEMPS IN THE M80S SLV TO L80S CPV TO M/U 70S MTNS. PREVIOUS DISCUSSION FOLLOWS...FOG WILL DISSIPATE THIS MORNING WITH CLOUDS MOVING IN FROM THE SOUTH EAST AS DEPARTING HIGH PRESSURE BRINGS SOUTHERLY TO SOUTHEASTERLY FLOW OVER THE REGION. THIS WILL ALLOW MOISTURE FROM YESTERDAYS FRONT TO SURGE NORTHWARD. A WEAK UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE FORECAST AREA TODAY. THIS FEATURE COMBINED WITH SOUTHEASTERLY UPSLOPE FLOW WILL BE ENOUGH CONVERGENCE TO DEVELOP FEW TO SCATTERED SHOWERS AND SLIGHT CHANCE FOR THUNDERSTORMS OVER THE HIGHER TERRAIN. BEST CHC FOR SHOWERS/STORMS WILL BE ACROSS EASTERN/CENTRAL VT GREEN MTNS AND HIGHER TERRAIN OF THE ADIRONDACKS. NAM AND GFS INDICATE AREAS OF OVER 1000J/KG THIS AFTERNOON. LACK OF SHEAR WILL KEEP ANY CONVECTIVE ACTIVITY SUB-SEVERE. WINDS MAINLY OUT OF THE SOUTH WILL CHANNEL UP THE CHAMPLAIN VALLEY...WITH SPEEDS OF 15-25 KTS OVER LAKE CHAMPLAIN AND OVER THE MTNS DURING THE DAY. 850HPA TEMPERATURES WILL WARM INTO THE MID TEENS OVER SOUTHERN VT AND UPPER TEENS IN NORTHERN NY. INCREASING CLOUDS WILL KEEP SFC TEMPS FROM REACHING FULL HEATING POTENTIAL OVER MOST OF VT. MAX TEMPS IN THE UPPER 70S TO AROUND 80 IN THE VALLEYS AND MID 60S TO LOW 70S OVER THE HIGHER TERRAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... AS OF 455 AM EDT THURSDAY...AS THE SUN SETS...INSTABILITY AND THEREFORE SHOWERS WILL DISSIPATE THIS EVENING. CLOUDS WILL CONTINUE TO INCREASE AS MOISTURE CONTINUES TO FILTER IN FROM THE SOUTHERLY FLOW. OVERNIGHT MIN TEMPS WILL BE IN THE LOW 60S IN THE VALLEYS AND REACHING THE MID 40S IN THE HIGHER TERRAIN. A COLD FRONT WILL APPROACH FROM THE GREAT LAKES REGION ON FRIDAY. GFS SLIGHTLY FASTER SOLUTION WITH BEST DEFORMATION OVER WESTERN NY BY 18Z. NAM A FEW HOURS SLOWER...BUT BOTH MODELS SHOW DEFORMATION WASHING OUT OVER EASTERN NY/SOUTHERN VT FRIDAY EVENING INTO SATURDAY MORNING. THIS COLD FRONT WILL BE ACCOMPANIED BY A MID LEVEL JET ENTRANCE REGION AT 850MB AND 700MB IN SOUTHEASTERN ONTARIO STRETCHING NORTHEAST INTO QUEBEC. CAN EXPECT SHOWERS AND THUNDERSTORMS TO AHEAD AND ACCOMPANYING THE COLD FRONT AS SOUTHERLY FLOW AHEAD OF THE FRONT CONTINUES TO BRING WARM MOIST AIR INTO THE REGION...AS NOTED BY SFC DEWPOINTS IN THE 60S. AS AN UPPER LEVEL TROF APPROACHES THE NORTHEAST...WIND SHEAR WILL INCREASE WITH BEST VALUES BETWEEN 25-30 KNOTS OF 0-3KM SHEAR AND 30-35 KTS OF 0-6 KM SHEAR. THIS MODEST SHEAR COMBINED WITH CAPE VALUES BETWEEN 1000 AND 2000 J/KG SUPPORT SCATTERED CONVECTION ALONG THE BOUNDARY WITH A FEW STRONGER STORMS. NOT ANTICIPATING A WIDESPREAD SEVERE WEATHER EVENT...BUT A FEW STRONGER STORMS WITH GUSTY WINDS AND DIME SIZE HAIL WILL BE POSSIBLE. SHOWERS AND THUNDERSTORM WILL CONTINUE INTO FRIDAY EVENING BEFORE THE FRONT MOVES THROUGH THE EASTERN EDGE OF THE FORECAST AREA AFTER MIDNIGHT. SATURDAY WILL SEE DRIER CONDITIONS BEHIND THE FRONT AS HIGH PRESSURE BUILDS IN OVER EASTERN ONTARIO/WESTERN QUEBEC. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... AS OF 348 PM EDT THURSDAY...GUIDANCE POINTS TO A RATHER ACTIVE PERIOD OF WEATHER FOR LATE MEMORIAL DAY WEEKEND INTO TUESDAY. THE POTENTIAL EXISTS FOR ONE OR SEVERAL ROUNDS OF SHOWERS OR THUNDERSTORMS DURING THIS PERIOD...ACCOMPANIED BY ABOVE-AVERAGE TEMPERATURES AND RATHER HUMID WEATHER. CONVECTIVE SCENARIO WILL DEPEND ON THUNDERSTORMS FROM PREVIOUS DAYS...SO IT IS DIFFICULT TO PINPOINT SPECIFICS AT THIS TIME. IT APPEARS THAT MONDAY AND/OR TUESDAY OFFER THE BEST POTENTIAL FOR THUNDER AS SHOWALTER INDICES DROP BELOW ZERO (ESPECIALLY ON MONDAY) WITH RATHER STRONG UPPER- LEVEL FLOW ALOFT. REGARDING TEMPERATURES...850MB TEMPERATURES STEADILY RISE FROM 12-13 C ON SUNDAY TO AROUND 14-16 C ON TUESDAY...LEADING TO HIGHS RISING FROM THE UPPER 70S TO THE LOWER/MID 80S WITH LOWS IN THE UPPER 50S TO THE LOWER/MID 60S. TEMPERATURES ON MONDAY APPEAR PARTICULARLY TRICKY EAST OF THE GREENS GIVEN FORECAST COOLER THICKNESSES THERE...SO HAVE KEPT HIGHS IN THE MID 70S IN THE NORTHEAST KINGDOM ON MONDAY. COLD FRONT LOOKS TO SWEEP ACROSS THE NORTH COUNTRY LATER TUESDAY...BRINGING WITH IT NOTICEABLY COOLER AND DRIER WEATHER TO THE REGION FOR WEDNESDAY INTO THE REMAINDER OF THE EXTENDED. && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... THROUGH 18Z FRIDAY...MOIST SOUTHEAST FLOW ALONG AND EAST OF THE GREENS BROUGHT SOME LOWER MVFR CEILINGS AT MPV THIS MORNING...THOUGH THESE HAVE BEGUN TO LIFT BY EARLY AFTERNOON. CURRENT SKIES RANGE FROM BKN/OVC VFR ACROSS MPV TO FEW/SCT VFR FOR THE REMAINDER OF THE TERMINALS. AFTERNOON MIXING IN THE PARTLY CLOUDY SKIES HAS RESULTED IN SOUTHERLY GUSTS TO AROUND 20KTS THIS AFTERNOON...AND THESE WILL CONTINUE THROUGH 23Z/00Z BEFORE BOUNDARY LAYER STABILIZES. THERE COULD BE A STRAY SHOWER OR PERHAPS A THUNDERSHOWER AT RUT THIS AFTERNOON WITH SOME INSTABILITY IN PLACE BUT NOT MUCH OF A TRIGGER...SO LEFT OUT FOR NOW. EXPECTING MAINLY VFR FOR TONIGHT THOUGH SOME 3SM BR WITH ASSOCIATED MVFR/IFR CEILINGS AT MPV AND SLK. DESPITE FAIRLY LIGHT WINDS TONIGHT THINK THAT THERE WILL BE ENOUGH TURBULENT MIXING TO LIMIT FOG FORMATION...THOUGH MIST LOOKS POSSIBLE. ANY LINGERING LOWER CEILINGS LIFT BY 12-14Z FRIDAY BRINGING VFR CEILINGS AND AFTERNOON SOUTHERLY GUSTS TO AROUND 20KTS. SURFACE TROUGH WILL APPROACH FROM THE WEST LATE IN THE TAF PERIOD...WHICH MAY TRIGGER SOME SHOWERS OR THUNDERSTORMS. THIS WILL BE MONITORED...THOUGH FEEL AT THIS TIME THAT ANY SHOWERS/STORMS WILL HOLD OFF UNTIL AFTER 18Z FRIDAY. OUTLOOK 18Z FRIDAY THROUGH MONDAY... 18Z FRIDAY - 06Z SATURDAY...VFR WITH PERIODS MVFR/IFR IN SCATTERED SHOWERS/STORMS AS COLD FRONT TRAVERSES THE REGION. 06Z SATURDAY - 12Z SUNDAY...VFR UNDER HIGH PRESSURE. POSSIBLE EVENING FOG/MIST AT MPV/SLK WITH IFR CEILINGS/VISIBILITIES. 12Z SUNDAY - 12Z MONDAY...VFR DEGRADING TO MVFR IN SHOWERS/POSSIBLE THUNDER LATER SUNDAY/SUNDAY NIGHT AS WARM FRONT MOVES NORTHWARD. 12Z MONDAY - 00Z TUESDAY...MAINLY VFR THOUGH CAN`T RULE OUT A SHOWER OR THUNDERSTORM MONDAY AFTERNOON. && .MARINE... A LAKE WIND ADVISORY IS NOW IN EFFECT THIS AFTERNOON INTO TONIGHT FOR LAKE CHAMPLAIN. SOUTH WINDS AT COLCHESTER REEF LATE THIS MORNING HAVE INCREASED TO NEAR 20 KNOTS...AND LOCAL BTV WRF MODELS SHOW SOUTHERLY FLOW INCREASING TO AROUND 25 KNOTS THIS AFTERNOON. EXPECT SOUTH WINDS TO BE IN THE 15 TO 25 KNOT RANGE WITH 2 FOOT WAVES ACROSS THE BROAD LAKE. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...KGM/TABER NEAR TERM...KGM/TABER SHORT TERM...KGM LONG TERM...LOCONTO AVIATION...LOCONTO MARINE...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
141 PM EDT THU MAY 24 2012 .SYNOPSIS... A SOUTHERLY FLOW OF WARM AIR WILL CONTINUE INTO THE HOLIDAY WEEKEND BRINGING AFTERNOON TEMPERATURES INTO THE 80S. AN UPPER LEVEL AREA OF LOW PRESSURE MAY TRIGGER A FEW THUNDERSTORMS THIS AFTERNOON..ESPECIALLY OVER THE POCONOS AND CATSKILLS. A WEAK FRONT PASSING THROUGH THE AREA ON FRIDAY MAY TRIGGER MORE WIDESPREAD THUNDERSTORMS. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WEAKNESS IN THE UPR RDG TO THE EAST ALLOWS FOR SOME INCRSD INSTABILITY OVER THE SRN AND ERN ZONES THIS AFTN. WILL CONT WITH THE FCST OF A CHANCE OR SLGT CHANCE OF TRWS IN THOSE AREAS. NAM HAS THE MOST CAPE...WITH BETTER THAN A THSND J/KG AT AVP LATE IN THE DAY. RUC AND ARW SEEM A BIT MORE RSNBL WITH ARND HALF THAT OF THE NAM. IN ANY CASE...THUNDER SHD BE ISLTD AND CHANCE OF SVR IS QUITE SMALL WITH A VERY WEAK WIND FIELD ALOFT. DENSE FOG THIS MRNG SHD ERODE QUICKLY WITH MIXING. MODELS GUID FOR HIGH TEMPS IN GOOD AGREEMENT WITH AFTN MAXES FROM THE MID 70S TO LOW 80S. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... YET ANOTHER WEAK BNDRY BANGS INTO THE RDGG SFC AND ALOFT ON FRI. NAM SHOWS SOME TALL AN SKINNY CAPE...ESP OVER THE NORTH ON FRI AFTN. LACK OF LL MOISTURE SHD LIMIT CONV DVLPMT BUT WITH THE BNDRY AND SOME WEAK HGT FALLS ALOFT...CHANCE POPS SEEM RSNBL FOR THE AFTN...WITH THE BEST CHANCE OVER THE NY COUNTIES. RDG BOUNCES BACK ON SAT WITH INCRSD HGTS AND WRMG ALOFT. THIS SERVES TO STABILIZE THE SNDG LIMITING THE PSBLTY OF AFTN TRW. SFC TEMPS BEGIN TO REBOUND AS WELL WITH TEMPS IN THE 80S ALL STATIONS AND THE MAV GUID PUSHING AVP INTO THE UPR 80S. ATTM THERE LOOKS TO BE LTL CHANCE OF SVR...AND WILL BE WELL BLO AND HEAT ADVISORY THRESHOLD SO WILL REMOVE CAUTIONARY WRDG FROM THE HWO AND JUST GO WITH A NIL STATEMENT. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... UPDATED AS OF 130 PM... NO BIG CHANGES TO THE LONG TERM FORECAST. BOTH THE EURO AND GFS SHOW A FRONTAL BOUNDARY DRAPED OVER THE AREA SUNDAY NIGHT THROUGH MONDAY NIGHT...WHICH WILL KEEP THE THREAT FOR SHOWERS AND STORMS AROUND. JUST AS THE FORECASTER POINTED OUT YESTERDAY THOUGH...WE ARE NOT EXPECTING A WASHOUT BUT WITH THE FRONT AROUND AND INCREASING WARMTH AND HUMIDITY...STORMS CAN`T BE RULED OUT. TEMPS WILL BE WELL INTO THE 80S MONDAY AND MAY APPROACH 90 ACROSS THE FINGER LAKES WITH THE 850 TEMPS ON THE EURO (18C TO 20C) ARE CORRECT. WITH TEMPS WELL INTO THE 80S TO NEAR 90...AND DEWPOINTS APPROACHING THE LOWER 70S...HEAT INDICES MONDAY MAY BE IN THE LOWER TO MIDDLE 90S. THE BOUNDARY MENTIONED ABOVE WILL LIFT NORTH MONDAY NIGHT INTO EARLY TUESDAY AND THIS WILL BRING US OUR BEST SHOT AT A LULL IN ACTIVITY. EVENTUALLY HOWEVER TOWARD TUESDAY AFTERNOON A COLD FRONT WILL APPROACH AND AGAIN SHOWERS AND STORMS WILL BE POSSIBLE. COOLER AND DRIER AIR WILL BUILD IN FOR MID-WEEK. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... GENERALLY VFR IS EXPECTED THROUGH 0Z TONIGHT. ISOLATED TO SCATTERED SHOWERS AND EVEN SOME RUMBLES OF THUNDER WILL IMPACT THE SOUTHERN TERMINALS. WHILE THUNDERSTORMS ARE POSSIBLE...EVEN THOUGH WE ARE SO CLOSE TO THE EVENT THE COVERAGE IS EXPECTED TO BE TOO ISOLATED TO MENTION IN THE TAFS. MOIST SOUTHEAST FLOW WILL BRING MORE RESTRICTIONS LATE TONIGHT ESPECIALLY ACROSS NE PA AND SOUTHERN TIER OF NEW YORK. FOR NOW WENT MVFR AFTER 06Z EVERYWHERE EXCEPT KSYR WHERE CONFIDENCE IS LOWER. ON FRIDAY MVFR CIGS WILL IMPROVE TO VFR BETWEEN 15Z AND 18Z. WINDS SOUTHEAST 10 TO 20 TODAY...BECOMING LIGHT SOUTHEAST TONIGHT. SOUTHEAST WINDS FRIDAY BECOMING SOUTHWEST 10 TO 20 WITH GUSTS TO 25 MPH. .OUTLOOK... FRIDAY AFTERNOON...MVFR POSSIBLE IN SCATTERED MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS. FRIDAY NIGHT THRU SUN...GENERALLY VFR. MONDAY/TUESDAY...MVFR POSSIBLE IN SCATTERED SHOWERS AND THUNDERSTORMS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...DGM NEAR TERM...DGM SHORT TERM...DGM LONG TERM...HEDEN AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
121 PM EDT THU MAY 24 2012 .SYNOPSIS... DEPARTING HIGH PRESSURE WILL BRING SOUTHERLY FLOW AND A CHANCE FOR UPSLOPE RAIN SHOWERS...MAINLY OVER THE HIGH TERRAIN TODAY. A BETTER CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS WILL ARRIVE LATE FRIDAY INTO FRIDAY NIGHT ASSOCIATED WITH A SURFACE COLD FRONT. SLIGHTLY COOLER AND DRIER CONDITIONS WILL PREVAIL FOR THE UPCOMING HOLIDAY WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 114 PM EDT THURSDAY...NO SIGNIFICANT CHANGES TO CRNT FCST WITH TEMPS WARMING INTO THE M70S SOUTHERN VT TO M80S IN THE SLV. THIS SFC HEATING HAS CREATED CAPE VALUES BTWN 1200 AND 1600 J/KG...BUT WATER VAPOR SHOWS BUILDING RIDGE AND STRONG AREA OF SUBSIDENCE ACRS OUR CWA. THIS WL RESULT IN LIMITED AREAL COVERAGE OF CONVECTION THIS AFTN...WITH BEST CHC ALONG THE SPINE OF THE GREEN MTNS AND ACRS PARTS OF NORTHERN NY. WL CONT TO MENTION SCHC TO CHC POPS ACRS THESE REGIONS. FCST IN GREAT SHAPE THIS MORNING WITH ONLY MINOR CHANGES NEEDED. VIS SATL PIC SHOWS LOW CLOUDS SLOWLY DISSIPATING ACRS EASTERN/CENTRAL VT AND PARTS OF THE DACKS. EXPECT AS SFC HEATING CONTS THESE CLOUDS WL DEVELOP INTO A SCATTERED/BROKEN CUMULUS/TOWERING CUMULUS DECK. RAP AND LOCAL BTV 4KM SHOWS SOME INSTABILITY DEVELOPING THIS AFTN AS SFC TEMPS WARM INTO THE U70S TO M80S...WITH CAPE VALUES AROUND 1000 J/KG AND LI VALUES NEAR -3C. HOWEVER...WATER VAPOR SHOWS LARGE AREA OF SUBSIDENCE AND ASSOCIATED DEEP DRY LAYER WITH BUILDING MID/UPPER LVL RIDGE ACRS OUR REGION. THIS WL LIMIT AREAL COVERAGE OF CONVECTION THIS AFTN...THINKING JUST A SCHC DACKS/SLV AND CENTRAL/EASTERN VT ZNS...WITH LOW CHC POPS NEAR KILLINGTON. MOST OF CWA WL BE RAINFREE THIS AFTN...WITH TEMPS IN THE M80S SLV TO L80S CPV TO M/U 70S MTNS. PREVIOUS DISCUSSION FOLLOWS...FOG WILL DISSIPATE THIS MORNING WITH CLOUDS MOVING IN FROM THE SOUTH EAST AS DEPARTING HIGH PRESSURE BRINGS SOUTHERLY TO SOUTHEASTERLY FLOW OVER THE REGION. THIS WILL ALLOW MOISTURE FROM YESTERDAYS FRONT TO SURGE NORTHWARD. A WEAK UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE FORECAST AREA TODAY. THIS FEATURE COMBINED WITH SOUTHEASTERLY UPSLOPE FLOW WILL BE ENOUGH CONVERGENCE TO DEVELOP FEW TO SCATTERED SHOWERS AND SLIGHT CHANCE FOR THUNDERSTORMS OVER THE HIGHER TERRAIN. BEST CHC FOR SHOWERS/STORMS WILL BE ACROSS EASTERN/CENTRAL VT GREEN MTNS AND HIGHER TERRAIN OF THE ADIRONDACKS. NAM AND GFS INDICATE AREAS OF OVER 1000J/KG THIS AFTERNOON. LACK OF SHEAR WILL KEEP ANY CONVECTIVE ACTIVITY SUB-SEVERE. WINDS MAINLY OUT OF THE SOUTH WILL CHANNEL UP THE CHAMPLAIN VALLEY...WITH SPEEDS OF 15-25 KTS OVER LAKE CHAMPLAIN AND OVER THE MTNS DURING THE DAY. 850HPA TEMPERATURES WILL WARM INTO THE MID TEENS OVER SOUTHERN VT AND UPPER TEENS IN NORTHERN NY. INCREASING CLOUDS WILL KEEP SFC TEMPS FROM REACHING FULL HEATING POTENTIAL OVER MOST OF VT. MAX TEMPS IN THE UPPER 70S TO AROUND 80 IN THE VALLEYS AND MID 60S TO LOW 70S OVER THE HIGHER TERRAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... AS OF 455 AM EDT THURSDAY...AS THE SUN SETS...INSTABILITY AND THEREFORE SHOWERS WILL DISSIPATE THIS EVENING. CLOUDS WILL CONTINUE TO INCREASE AS MOISTURE CONTINUES TO FILTER IN FROM THE SOUTHERLY FLOW. OVERNIGHT MIN TEMPS WILL BE IN THE LOW 60S IN THE VALLEYS AND REACHING THE MID 40S IN THE HIGHER TERRAIN. A COLD FRONT WILL APPROACH FROM THE GREAT LAKES REGION ON FRIDAY. GFS SLIGHTLY FASTER SOLUTION WITH BEST DEFORMATION OVER WESTERN NY BY 18Z. NAM A FEW HOURS SLOWER...BUT BOTH MODELS SHOW DEFORMATION WASHING OUT OVER EASTERN NY/SOUTHERN VT FRIDAY EVENING INTO SATURDAY MORNING. THIS COLD FRONT WILL BE ACCOMPANIED BY A MID LEVEL JET ENTRANCE REGION AT 850MB AND 700MB IN SOUTHEASTERN ONTARIO STRETCHING NORTHEAST INTO QUEBEC. CAN EXPECT SHOWERS AND THUNDERSTORMS TO AHEAD AND ACCOMPANYING THE COLD FRONT AS SOUTHERLY FLOW AHEAD OF THE FRONT CONTINUES TO BRING WARM MOIST AIR INTO THE REGION...AS NOTED BY SFC DEWPOINTS IN THE 60S. AS AN UPPER LEVEL TROF APPROACHES THE NORTHEAST...WIND SHEAR WILL INCREASE WITH BEST VALUES BETWEEN 25-30 KNOTS OF 0-3KM SHEAR AND 30-35 KTS OF 0-6 KM SHEAR. THIS MODEST SHEAR COMBINED WITH CAPE VALUES BETWEEN 1000 AND 2000 J/KG SUPPORT SCATTERED CONVECTION ALONG THE BOUNDARY WITH A FEW STRONGER STORMS. NOT ANTICIPATING A WIDESPREAD SEVERE WEATHER EVENT...BUT A FEW STRONGER STORMS WITH GUSTY WINDS AND DIME SIZE HAIL WILL BE POSSIBLE. SHOWERS AND THUNDERSTORM WILL CONTINUE INTO FRIDAY EVENING BEFORE THE FRONT MOVES THROUGH THE EASTERN EDGE OF THE FORECAST AREA AFTER MIDNIGHT. SATURDAY WILL SEE DRIER CONDITIONS BEHIND THE FRONT AS HIGH PRESSURE BUILDS IN OVER EASTERN ONTARIO/WESTERN QUEBEC. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 521 AM EDT THURSDAY...A RIDGE OF HIGH PRESSURE WILL BE OVER THE REGION SATURDAY NIGHT THROUGH SUNDAY NIGHT...WITH FAIR AND DRY WEATHER EXPECTED. A FRONTAL SYSTEM JUST SOUTH OF THE REGION SUNDAY NIGHT WILL BEGIN TO MOVE SLOWLY NORTHEAST AS A WARM FRONT ON MONDAY. EXPECTING SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS THE REGION MONDAY AFTERNOON AND CONTINUING INTO MONDAY NIGHT AND TUESDAY. A COLD FRONT WILL THEN MOVE THROUGH THE REGION TUESDAY NIGHT WITH A CHANCE FOR SOME MORE SHOWERS AND THUNDERSTORMS. EXPECTING COOLER TEMPERATURES ALONG WITH CLOUD COVER LINGERING ACROSS THE REGION ON WEDNESDAY...SO HAVE KEPT IN SLIGHT CHANCE POPS FOR SHOWERS ON WEDNESDAY. TEMPERATURE FORECAST FOR MONDAY AND TUESDAY COULD BE A BIT TRICKY AND WILL DEPEND ON WHERE THIS SLOW MOVING WARM FRONT WILL BE ACROSS THE REGION ON THESE DAYS. HAVE LEANED TOWARD ENSEMBLE MOS MEANS FOR MAX AND MIN TEMPERATURES ON MONDAY AND TUESDAY. && .AVIATION /17Z THURSDAY THROUGH MONDAY/... THROUGH 18Z FRIDAY...MOIST SOUTHEAST FLOW ALONG AND EAST OF THE GREENS BROUGHT SOME LOWER MVFR CEILINGS AT MPV THIS MORNING...THOUGH THESE HAVE BEGUN TO LIFT BY EARLY AFTERNOON. CURRENT SKIES RANGE FROM BKN/OVC VFR ACROSS MPV TO FEW/SCT VFR FOR THE REMAINDER OF THE TERMINALS. AFTERNOON MIXING IN THE PARTLY CLOUDY SKIES HAS RESULTED IN SOUTHERLY GUSTS TO AROUND 20KTS THIS AFTERNOON...AND THESE WILL CONTINUE THROUGH 23Z/00Z BEFORE BOUNDARY LAYER STABILIZES. THERE COULD BE A STRAY SHOWER OR PERHAPS A THUNDERSHOWER AT RUT THIS AFTERNOON WITH SOME INSTABILITY IN PLACE BUT NOT MUCH OF A TRIGGER...SO LEFT OUT FOR NOW. EXPECTING MAINLY VFR FOR TONIGHT THOUGH SOME 3SM BR WITH ASSOCIATED MVFR/IFR CEILINGS AT MPV AND SLK. DESPITE FAIRLY LIGHT WINDS TONIGHT THINK THAT THERE WILL BE ENOUGH TURBULENT MIXING TO LIMIT FOG FORMATION...THOUGH MIST LOOKS POSSIBLE. ANY LINGERING LOWER CEILINGS LIFT BY 12-14Z FRIDAY BRINGING VFR CEILINGS AND AFTERNOON SOUTHERLY GUSTS TO AROUND 20KTS. SURFACE TROUGH WILL APPROACH FROM THE WEST LATE IN THE TAF PERIOD...WHICH MAY TRIGGER SOME SHOWERS OR THUNDERSTORMS. THIS WILL BE MONITORED...THOUGH FEEL AT THIS TIME THAT ANY SHOWERS/STORMS WILL HOLD OFF UNTIL AFTER 18Z FRIDAY. OUTLOOK 18Z FRIDAY THROUGH MONDAY... 18Z FRIDAY - 06Z SATURDAY...VFR WITH PERIODS MVFR/IFR IN SCATTERED SHOWERS/STORMS AS COLD FRONT TRAVERSES THE REGION. 06Z SATURDAY - 12Z SUNDAY...VFR UNDER HIGH PRESSURE. POSSIBLE EVENING FOG/MIST AT MPV/SLK WITH IFR CEILINGS/VISIBILITIES. 12Z SUNDAY - 12Z MONDAY...VFR DEGRADING TO MVFR IN SHOWERS/POSSIBLE THUNDER LATER SUNDAY/SUNDAY NIGHT AS WARM FRONT MOVES NORTHWARD. 12Z MONDAY - 00Z TUESDAY...MAINLY VFR THOUGH CAN`T RULE OUT A SHOWER OR THUNDERSTORM MONDAY AFTERNOON. && .MARINE... A LAKE WIND ADVISORY IS NOW IN EFFECT THIS AFTERNOON INTO TONIGHT FOR LAKE CHAMPLAIN. SOUTH WINDS AT COLCHESTER REEF LATE THIS MORNING HAVE INCREASED TO NEAR 20 KNOTS...AND LOCAL BTV WRF MODELS SHOW SOUTHERLY FLOW INCREASING TO AROUND 25 KNOTS THIS AFTERNOON. EXPECT SOUTH WINDS TO BE IN THE 15 TO 25 KNOT RANGE WITH 2 FOOT WAVES ACROSS THE BROAD LAKE. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...KGM/TABER NEAR TERM...KGM/TABER SHORT TERM...KGM LONG TERM...WGH AVIATION...LOCONTO MARINE...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
111 PM EDT THU MAY 24 2012 .SYNOPSIS... DEPARTING HIGH PRESSURE WILL BRING SOUTHERLY FLOW AND A CHANCE FOR UPSLOPE RAIN SHOWERS...MAINLY OVER THE HIGH TERRAIN TODAY. A BETTER CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS WILL ARRIVE LATE FRIDAY INTO FRIDAY NIGHT ASSOCIATED WITH A SURFACE COLD FRONT. SLIGHTLY COOLER AND DRIER CONDITIONS WILL PREVAIL FOR THE UPCOMING HOLIDAY WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1010 AM EDT THURSDAY...FCST IN GREAT SHAPE THIS MORNING WITH ONLY MINOR CHANGES NEEDED. VIS SATL PIC SHOWS LOW CLOUDS SLOWLY DISSIPATING ACRS EASTERN/CENTRAL VT AND PARTS OF THE DACKS. EXPECT AS SFC HEATING CONTS THESE CLOUDS WL DEVELOP INTO A SCATTERED/BROKEN CUMULUS/TOWERING CUMULUS DECK. RAP AND LOCAL BTV 4KM SHOWS SOME INSTABILITY DEVELOPING THIS AFTN AS SFC TEMPS WARM INTO THE U70S TO M80S...WITH CAPE VALUES AROUND 1000 J/KG AND LI VALUES NEAR -3C. HOWEVER...WATER VAPOR SHOWS LARGE AREA OF SUBSIDENCE AND ASSOCIATED DEEP DRY LAYER WITH BUILDING MID/UPPER LVL RIDGE ACRS OUR REGION. THIS WL LIMIT AREAL COVERAGE OF CONVECTION THIS AFTN...THINKING JUST A SCHC DACKS/SLV AND CENTRAL/EASTERN VT ZNS...WITH LOW CHC POPS NEAR KILLINGTON. MOST OF CWA WL BE RAINFREE THIS AFTN...WITH TEMPS IN THE M80S SLV TO L80S CPV TO M/U 70S MTNS. PREVIOUS DISCUSSION FOLLOWS...FOG WILL DISSIPATE THIS MORNING WITH CLOUDS MOVING IN FROM THE SOUTH EAST AS DEPARTING HIGH PRESSURE BRINGS SOUTHERLY TO SOUTHEASTERLY FLOW OVER THE REGION. THIS WILL ALLOW MOISTURE FROM YESTERDAYS FRONT TO SURGE NORTHWARD. A WEAK UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE FORECAST AREA TODAY. THIS FEATURE COMBINED WITH SOUTHEASTERLY UPSLOPE FLOW WILL BE ENOUGH CONVERGENCE TO DEVELOP FEW TO SCATTERED SHOWERS AND SLIGHT CHANCE FOR THUNDERSTORMS OVER THE HIGHER TERRAIN. BEST CHC FOR SHOWERS/STORMS WILL BE ACROSS EASTERN/CENTRAL VT GREEN MTNS AND HIGHER TERRAIN OF THE ADIRONDACKS. NAM AND GFS INDICATE AREAS OF OVER 1000J/KG THIS AFTERNOON. LACK OF SHEAR WILL KEEP ANY CONVECTIVE ACTIVITY SUB-SEVERE. WINDS MAINLY OUT OF THE SOUTH WILL CHANNEL UP THE CHAMPLAIN VALLEY...WITH SPEEDS OF 15-25 KTS OVER LAKE CHAMPLAIN AND OVER THE MTNS DURING THE DAY. 850HPA TEMPERATURES WILL WARM INTO THE MID TEENS OVER SOUTHERN VT AND UPPER TEENS IN NORTHERN NY. INCREASING CLOUDS WILL KEEP SFC TEMPS FROM REACHING FULL HEATING POTENTIAL OVER MOST OF VT. MAX TEMPS IN THE UPPER 70S TO AROUND 80 IN THE VALLEYS AND MID 60S TO LOW 70S OVER THE HIGHER TERRAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... AS OF 455 AM EDT THURSDAY...AS THE SUN SETS...INSTABILITY AND THEREFORE SHOWERS WILL DISSIPATE THIS EVENING. CLOUDS WILL CONTINUE TO INCREASE AS MOISTURE CONTINUES TO FILTER IN FROM THE SOUTHERLY FLOW. OVERNIGHT MIN TEMPS WILL BE IN THE LOW 60S IN THE VALLEYS AND REACHING THE MID 40S IN THE HIGHER TERRAIN. A COLD FRONT WILL APPROACH FROM THE GREAT LAKES REGION ON FRIDAY. GFS SLIGHTLY FASTER SOLUTION WITH BEST DEFORMATION OVER WESTERN NY BY 18Z. NAM A FEW HOURS SLOWER...BUT BOTH MODELS SHOW DEFORMATION WASHING OUT OVER EASTERN NY/SOUTHERN VT FRIDAY EVENING INTO SATURDAY MORNING. THIS COLD FRONT WILL BE ACCOMPANIED BY A MID LEVEL JET ENTRANCE REGION AT 850MB AND 700MB IN SOUTHEASTERN ONTARIO STRETCHING NORTHEAST INTO QUEBEC. CAN EXPECT SHOWERS AND THUNDERSTORMS TO AHEAD AND ACCOMPANYING THE COLD FRONT AS SOUTHERLY FLOW AHEAD OF THE FRONT CONTINUES TO BRING WARM MOIST AIR INTO THE REGION...AS NOTED BY SFC DEWPOINTS IN THE 60S. AS AN UPPER LEVEL TROF APPROACHES THE NORTHEAST...WIND SHEAR WILL INCREASE WITH BEST VALUES BETWEEN 25-30 KNOTS OF 0-3KM SHEAR AND 30-35 KTS OF 0-6 KM SHEAR. THIS MODEST SHEAR COMBINED WITH CAPE VALUES BETWEEN 1000 AND 2000 J/KG SUPPORT SCATTERED CONVECTION ALONG THE BOUNDARY WITH A FEW STRONGER STORMS. NOT ANTICIPATING A WIDESPREAD SEVERE WEATHER EVENT...BUT A FEW STRONGER STORMS WITH GUSTY WINDS AND DIME SIZE HAIL WILL BE POSSIBLE. SHOWERS AND THUNDERSTORM WILL CONTINUE INTO FRIDAY EVENING BEFORE THE FRONT MOVES THROUGH THE EASTERN EDGE OF THE FORECAST AREA AFTER MIDNIGHT. SATURDAY WILL SEE DRIER CONDITIONS BEHIND THE FRONT AS HIGH PRESSURE BUILDS IN OVER EASTERN ONTARIO/WESTERN QUEBEC. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 521 AM EDT THURSDAY...A RIDGE OF HIGH PRESSURE WILL BE OVER THE REGION SATURDAY NIGHT THROUGH SUNDAY NIGHT...WITH FAIR AND DRY WEATHER EXPECTED. A FRONTAL SYSTEM JUST SOUTH OF THE REGION SUNDAY NIGHT WILL BEGIN TO MOVE SLOWLY NORTHEAST AS A WARM FRONT ON MONDAY. EXPECTING SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS THE REGION MONDAY AFTERNOON AND CONTINUING INTO MONDAY NIGHT AND TUESDAY. A COLD FRONT WILL THEN MOVE THROUGH THE REGION TUESDAY NIGHT WITH A CHANCE FOR SOME MORE SHOWERS AND THUNDERSTORMS. EXPECTING COOLER TEMPERATURES ALONG WITH CLOUD COVER LINGERING ACROSS THE REGION ON WEDNESDAY...SO HAVE KEPT IN SLIGHT CHANCE POPS FOR SHOWERS ON WEDNESDAY. TEMPERATURE FORECAST FOR MONDAY AND TUESDAY COULD BE A BIT TRICKY AND WILL DEPEND ON WHERE THIS SLOW MOVING WARM FRONT WILL BE ACROSS THE REGION ON THESE DAYS. HAVE LEANED TOWARD ENSEMBLE MOS MEANS FOR MAX AND MIN TEMPERATURES ON MONDAY AND TUESDAY. && .AVIATION /17Z THURSDAY THROUGH MONDAY/... THROUGH 18Z FRIDAY...MOIST SOUTHEAST FLOW ALONG AND EAST OF THE GREENS BROUGHT SOME LOWER MVFR CEILINGS AT MPV THIS MORNING...THOUGH THESE HAVE BEGUN TO LIFT BY EARLY AFTERNOON. CURRENT SKIES RANGE FROM BKN/OVC VFR ACROSS MPV TO FEW/SCT VFR FOR THE REMAINDER OF THE TERMINALS. AFTERNOON MIXING IN THE PARTLY CLOUDY SKIES HAS RESULTED IN SOUTHERLY GUSTS TO AROUND 20KTS THIS AFTERNOON...AND THESE WILL CONTINUE THROUGH 23Z/00Z BEFORE BOUNDARY LAYER STABILIZES. THERE COULD BE A STRAY SHOWER OR PERHAPS A THUNDERSHOWER AT RUT THIS AFTERNOON WITH SOME INSTABILITY IN PLACE BUT NOT MUCH OF A TRIGGER...SO LEFT OUT FOR NOW. EXPECTING MAINLY VFR FOR TONIGHT THOUGH SOME 3SM BR WITH ASSOCIATED MVFR/IFR CEILINGS AT MPV AND SLK. DESPITE FAIRLY LIGHT WINDS TONIGHT THINK THAT THERE WILL BE ENOUGH TURBULENT MIXING TO LIMIT FOG FORMATION...THOUGH MIST LOOKS POSSIBLE. ANY LINGERING LOWER CEILINGS LIFT BY 12-14Z FRIDAY BRINGING VFR CEILINGS AND AFTERNOON SOUTHERLY GUSTS TO AROUND 20KTS. SURFACE TROUGH WILL APPROACH FROM THE WEST LATE IN THE TAF PERIOD...WHICH MAY TRIGGER SOME SHOWERS OR THUNDERSTORMS. THIS WILL BE MONITORED...THOUGH FEEL AT THIS TIME THAT ANY SHOWERS/STORMS WILL HOLD OFF UNTIL AFTER 18Z FRIDAY. OUTLOOK 18Z FRIDAY THROUGH MONDAY... 18Z FRIDAY - 06Z SATURDAY...VFR WITH PERIODS MVFR/IFR IN SCATTERED SHOWERS/STORMS AS COLD FRONT TRAVERSES THE REGION. 06Z SATURDAY - 12Z SUNDAY...VFR UNDER HIGH PRESSURE. POSSIBLE EVENING FOG/MIST AT MPV/SLK WITH IFR CEILINGS/VISIBILITIES. 12Z SUNDAY - 12Z MONDAY...VFR DEGRADING TO MVFR IN SHOWERS/POSSIBLE THUNDER LATER SUNDAY/SUNDAY NIGHT AS WARM FRONT MOVES NORTHWARD. 12Z MONDAY - 00Z TUESDAY...MAINLY VFR THOUGH CAN`T RULE OUT A SHOWER OR THUNDERSTORM MONDAY AFTERNOON. && .MARINE... A LAKE WIND ADVISORY IS NOW IN EFFECT THIS AFTERNOON INTO TONIGHT FOR LAKE CHAMPLAIN. SOUTH WINDS AT COLCHESTER REEF LATE THIS MORNING HAVE INCREASED TO NEAR 20 KNOTS...AND LOCAL BTV WRF MODELS SHOW SOUTHERLY FLOW INCREASING TO AROUND 25 KNOTS THIS AFTERNOON. EXPECT SOUTH WINDS TO BE IN THE 15 TO 25 KNOT RANGE WITH 2 FOOT WAVES ACROSS THE BROAD LAKE. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...KGM/TABER NEAR TERM...KGM/TABER SHORT TERM...KGM LONG TERM...WGH AVIATION...LOCONTO MARINE...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
110 PM EDT THU MAY 24 2012 .SYNOPSIS... DEPARTING HIGH PRESSURE WILL BRING SOUTHERLY FLOW AND A CHANCE FOR UPSLOPE RAIN SHOWERS...MAINLY OVER THE HIGH TERRAIN TODAY. A BETTER CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS WILL ARRIVE LATE FRIDAY INTO FRIDAY NIGHT ASSOCIATED WITH A SURFACE COLD FRONT. SLIGHTLY COOLER AND DRIER CONDITIONS WILL PREVAIL FOR THE UPCOMING HOLIDAY WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1010 AM EDT THURSDAY...FCST IN GREAT SHAPE THIS MORNING WITH ONLY MINOR CHANGES NEEDED. VIS SATL PIC SHOWS LOW CLOUDS SLOWLY DISSIPATING ACRS EASTERN/CENTRAL VT AND PARTS OF THE DACKS. EXPECT AS SFC HEATING CONTS THESE CLOUDS WL DEVELOP INTO A SCATTERED/BROKEN CUMULUS/TOWERING CUMULUS DECK. RAP AND LOCAL BTV 4KM SHOWS SOME INSTABILITY DEVELOPING THIS AFTN AS SFC TEMPS WARM INTO THE U70S TO M80S...WITH CAPE VALUES AROUND 1000 J/KG AND LI VALUES NEAR -3C. HOWEVER...WATER VAPOR SHOWS LARGE AREA OF SUBSIDENCE AND ASSOCIATED DEEP DRY LAYER WITH BUILDING MID/UPPER LVL RIDGE ACRS OUR REGION. THIS WL LIMIT AREAL COVERAGE OF CONVECTION THIS AFTN...THINKING JUST A SCHC DACKS/SLV AND CENTRAL/EASTERN VT ZNS...WITH LOW CHC POPS NEAR KILLINGTON. MOST OF CWA WL BE RAINFREE THIS AFTN...WITH TEMPS IN THE M80S SLV TO L80S CPV TO M/U 70S MTNS. PREVIOUS DISCUSSION FOLLOWS...FOG WILL DISSIPATE THIS MORNING WITH CLOUDS MOVING IN FROM THE SOUTH EAST AS DEPARTING HIGH PRESSURE BRINGS SOUTHERLY TO SOUTHEASTERLY FLOW OVER THE REGION. THIS WILL ALLOW MOISTURE FROM YESTERDAYS FRONT TO SURGE NORTHWARD. A WEAK UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE FORECAST AREA TODAY. THIS FEATURE COMBINED WITH SOUTHEASTERLY UPSLOPE FLOW WILL BE ENOUGH CONVERGENCE TO DEVELOP FEW TO SCATTERED SHOWERS AND SLIGHT CHANCE FOR THUNDERSTORMS OVER THE HIGHER TERRAIN. BEST CHC FOR SHOWERS/STORMS WILL BE ACROSS EASTERN/CENTRAL VT GREEN MTNS AND HIGHER TERRAIN OF THE ADIRONDACKS. NAM AND GFS INDICATE AREAS OF OVER 1000J/KG THIS AFTERNOON. LACK OF SHEAR WILL KEEP ANY CONVECTIVE ACTIVITY SUB-SEVERE. WINDS MAINLY OUT OF THE SOUTH WILL CHANNEL UP THE CHAMPLAIN VALLEY...WITH SPEEDS OF 15-25 KTS OVER LAKE CHAMPLAIN AND OVER THE MTNS DURING THE DAY. 850HPA TEMPERATURES WILL WARM INTO THE MID TEENS OVER SOUTHERN VT AND UPPER TEENS IN NORTHERN NY. INCREASING CLOUDS WILL KEEP SFC TEMPS FROM REACHING FULL HEATING POTENTIAL OVER MOST OF VT. MAX TEMPS IN THE UPPER 70S TO AROUND 80 IN THE VALLEYS AND MID 60S TO LOW 70S OVER THE HIGHER TERRAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... AS OF 455 AM EDT THURSDAY...AS THE SUN SETS...INSTABILITY AND THEREFORE SHOWERS WILL DISSIPATE THIS EVENING. CLOUDS WILL CONTINUE TO INCREASE AS MOISTURE CONTINUES TO FILTER IN FROM THE SOUTHERLY FLOW. OVERNIGHT MIN TEMPS WILL BE IN THE LOW 60S IN THE VALLEYS AND REACHING THE MID 40S IN THE HIGHER TERRAIN. A COLD FRONT WILL APPROACH FROM THE GREAT LAKES REGION ON FRIDAY. GFS SLIGHTLY FASTER SOLUTION WITH BEST DEFORMATION OVER WESTERN NY BY 18Z. NAM A FEW HOURS SLOWER...BUT BOTH MODELS SHOW DEFORMATION WASHING OUT OVER EASTERN NY/SOUTHERN VT FRIDAY EVENING INTO SATURDAY MORNING. THIS COLD FRONT WILL BE ACCOMPANIED BY A MID LEVEL JET ENTRANCE REGION AT 850MB AND 700MB IN SOUTHEASTERN ONTARIO STRETCHING NORTHEAST INTO QUEBEC. CAN EXPECT SHOWERS AND THUNDERSTORMS TO AHEAD AND ACCOMPANYING THE COLD FRONT AS SOUTHERLY FLOW AHEAD OF THE FRONT CONTINUES TO BRING WARM MOIST AIR INTO THE REGION...AS NOTED BY SFC DEWPOINTS IN THE 60S. AS AN UPPER LEVEL TROF APPROACHES THE NORTHEAST...WIND SHEAR WILL INCREASE WITH BEST VALUES BETWEEN 25-30 KNOTS OF 0-3KM SHEAR AND 30-35 KTS OF 0-6 KM SHEAR. THIS MODEST SHEAR COMBINED WITH CAPE VALUES BETWEEN 1000 AND 2000 J/KG SUPPORT SCATTERED CONVECTION ALONG THE BOUNDARY WITH A FEW STRONGER STORMS. NOT ANTICIPATING A WIDESPREAD SEVERE WEATHER EVENT...BUT A FEW STRONGER STORMS WITH GUSTY WINDS AND DIME SIZE HAIL WILL BE POSSIBLE. SHOWERS AND THUNDERSTORM WILL CONTINUE INTO FRIDAY EVENING BEFORE THE FRONT MOVES THROUGH THE EASTERN EDGE OF THE FORECAST AREA AFTER MIDNIGHT. SATURDAY WILL SEE DRIER CONDITIONS BEHIND THE FRONT AS HIGH PRESSURE BUILDS IN OVER EASTERN ONTARIO/WESTERN QUEBEC. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 521 AM EDT THURSDAY...A RIDGE OF HIGH PRESSURE WILL BE OVER THE REGION SATURDAY NIGHT THROUGH SUNDAY NIGHT...WITH FAIR AND DRY WEATHER EXPECTED. A FRONTAL SYSTEM JUST SOUTH OF THE REGION SUNDAY NIGHT WILL BEGIN TO MOVE SLOWLY NORTHEAST AS A WARM FRONT ON MONDAY. EXPECTING SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS THE REGION MONDAY AFTERNOON AND CONTINUING INTO MONDAY NIGHT AND TUESDAY. A COLD FRONT WILL THEN MOVE THROUGH THE REGION TUESDAY NIGHT WITH A CHANCE FOR SOME MORE SHOWERS AND THUNDERSTORMS. EXPECTING COOLER TEMPERATURES ALONG WITH CLOUD COVER LINGERING ACROSS THE REGION ON WEDNESDAY...SO HAVE KEPT IN SLIGHT CHANCE POPS FOR SHOWERS ON WEDNESDAY. TEMPERATURE FORECAST FOR MONDAY AND TUESDAY COULD BE A BIT TRICKY AND WILL DEPEND ON WHERE THIS SLOW MOVING WARM FRONT WILL BE ACROSS THE REGION ON THESE DAYS. HAVE LEANED TOWARD ENSEMBLE MOS MEANS FOR MAX AND MIN TEMPERATURES ON MONDAY AND TUESDAY. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... THROUGH 12Z FRIDAY...MOIST SOUTHEAST FLOW ALONG AND EAST OF THE GREENS BROUGHT SOME LOWER MVFR CEILINGS AT MPV THIS MORNING...THOUGH THESE HAVE BEGUN TO LIFT BY EARLY AFTERNOON. CURRENT SKIES RANGE FROM BKN/OVC VFR ACROSS MPV TO FEW/SCT VFR FOR THE REMAINDER OF THE TERMINALS. AFTERNOON MIXING IN THE PARTLY CLOUDY SKIES HAS RESULTED IN SOUTHERLY GUSTS TO AROUND 20KTS THIS AFTERNOON...AND THESE WILL CONTINUE THROUGH 23Z/00Z BEFORE BOUNDARY LAYER STABILIZES. THERE COULD BE A STRAY SHOWER OR PERHAPS A THUNDERSHOWER AT RUT THIS AFTERNOON WITH SOME INSTABILITY IN PLACE BUT NOT MUCH OF A TRIGGER...SO LEFT OUT FOR NOW. EXPECTING MAINLY VFR FOR TONIGHT THOUGH SOME 3SM BR WITH ASSOCIATED MVFR/IFR CEILINGS AT MPV AND SLK. DESPITE FAIRLY LIGHT WINDS TONIGHT THINK THAT THERE WILL BE ENOUGH TURBULENT MIXING TO LIMIT FOG FORMATION...THOUGH MIST LOOKS POSSIBLE. ANY LINGERING LOWER CEILINGS LIFT BY 12-14Z FRIDAY BRINGING VFR CEILINGS AND AFTERNOON SOUTHERLY GUSTS TO AROUND 20KTS. SURFACE TROUGH WILL APPROACH FROM THE WEST LATE IN THE TAF PERIOD...WHICH MAY TRIGGER SOME SHOWERS OR THUNDERSTORMS. THIS WILL BE MONITORED...THOUGH FEEL AT THIS TIME THAT ANY SHOWERS/STORMS WILL HOLD OFF UNTIL AFTER 18Z FRIDAY. OUTLOOK 18Z FRIDAY THROUGH MONDAY... 18Z FRIDAY - 06Z SATURDAY...VFR WITH PERIODS MVFR/IFR IN SCATTERED SHOWERS/STORMS AS COLD FRONT TRAVERSES THE REGION. 06Z SATURDAY - 12Z SUNDAY...VFR UNDER HIGH PRESSURE. POSSIBLE EVENING FOG/MIST AT MPV/SLK WITH IFR CEILINGS/VISIBILITIES. 12Z SUNDAY - 12Z MONDAY...VFR DEGRADING TO MVFR IN SHOWERS/POSSIBLE THUNDER LATER SUNDAY/SUNDAY NIGHT AS WARM FRONT MOVES NORTHWARD. 12Z MONDAY - 00Z TUESDAY...MAINLY VFR THOUGH CAN`T RULE OUT A SHOWER OR THUNDERSTORM MONDAY AFTERNOON. && .MARINE... A LAKE WIND ADVISORY IS NOW IN EFFECT THIS AFTERNOON INTO TONIGHT FOR LAKE CHAMPLAIN. SOUTH WINDS AT COLCHESTER REEF LATE THIS MORNING HAVE INCREASED TO NEAR 20 KNOTS...AND LOCAL BTV WRF MODELS SHOW SOUTHERLY FLOW INCREASING TO AROUND 25 KNOTS THIS AFTERNOON. EXPECT SOUTH WINDS TO BE IN THE 15 TO 25 KNOT RANGE WITH 2 FOOT WAVES ACROSS THE BROAD LAKE. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...KGM/TABER NEAR TERM...KGM/TABER SHORT TERM...KGM LONG TERM...WGH AVIATION...LOCONTO MARINE...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1209 PM EDT THU MAY 24 2012 .SYNOPSIS... DEPARTING HIGH PRESSURE WILL BRING SOUTHERLY FLOW AND A CHANCE FOR UPSLOPE RAIN SHOWERS...MAINLY OVER THE HIGH TERRAIN TODAY. A BETTER CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS WILL ARRIVE LATE FRIDAY INTO FRIDAY NIGHT ASSOCIATED WITH A SURFACE COLD FRONT. SLIGHTLY COOLER AND DRIER CONDITIONS WILL PREVAIL FOR THE UPCOMING HOLIDAY WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1010 AM EDT THURSDAY...FCST IN GREAT SHAPE THIS MORNING WITH ONLY MINOR CHANGES NEEDED. VIS SATL PIC SHOWS LOW CLOUDS SLOWLY DISSIPATING ACRS EASTERN/CENTRAL VT AND PARTS OF THE DACKS. EXPECT AS SFC HEATING CONTS THESE CLOUDS WL DEVELOP INTO A SCATTERED/BROKEN CUMULUS/TOWERING CUMULUS DECK. RAP AND LOCAL BTV 4KM SHOWS SOME INSTABILITY DEVELOPING THIS AFTN AS SFC TEMPS WARM INTO THE U70S TO M80S...WITH CAPE VALUES AROUND 1000 J/KG AND LI VALUES NEAR -3C. HOWEVER...WATER VAPOR SHOWS LARGE AREA OF SUBSIDENCE AND ASSOCIATED DEEP DRY LAYER WITH BUILDING MID/UPPER LVL RIDGE ACRS OUR REGION. THIS WL LIMIT AREAL COVERAGE OF CONVECTION THIS AFTN...THINKING JUST A SCHC DACKS/SLV AND CENTRAL/EASTERN VT ZNS...WITH LOW CHC POPS NEAR KILLINGTON. MOST OF CWA WL BE RAINFREE THIS AFTN...WITH TEMPS IN THE M80S SLV TO L80S CPV TO M/U 70S MTNS. PREVIOUS DISCUSSION FOLLOWS...FOG WILL DISSIPATE THIS MORNING WITH CLOUDS MOVING IN FROM THE SOUTH EAST AS DEPARTING HIGH PRESSURE BRINGS SOUTHERLY TO SOUTHEASTERLY FLOW OVER THE REGION. THIS WILL ALLOW MOISTURE FROM YESTERDAYS FRONT TO SURGE NORTHWARD. A WEAK UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE FORECAST AREA TODAY. THIS FEATURE COMBINED WITH SOUTHEASTERLY UPSLOPE FLOW WILL BE ENOUGH CONVERGENCE TO DEVELOP FEW TO SCATTERED SHOWERS AND SLIGHT CHANCE FOR THUNDERSTORMS OVER THE HIGHER TERRAIN. BEST CHC FOR SHOWERS/STORMS WILL BE ACROSS EASTERN/CENTRAL VT GREEN MTNS AND HIGHER TERRAIN OF THE ADIRONDACKS. NAM AND GFS INDICATE AREAS OF OVER 1000J/KG THIS AFTERNOON. LACK OF SHEAR WILL KEEP ANY CONVECTIVE ACTIVITY SUB-SEVERE. WINDS MAINLY OUT OF THE SOUTH WILL CHANNEL UP THE CHAMPLAIN VALLEY...WITH SPEEDS OF 15-25 KTS OVER LAKE CHAMPLAIN AND OVER THE MTNS DURING THE DAY. 850HPA TEMPERATURES WILL WARM INTO THE MID TEENS OVER SOUTHERN VT AND UPPER TEENS IN NORTHERN NY. INCREASING CLOUDS WILL KEEP SFC TEMPS FROM REACHING FULL HEATING POTENTIAL OVER MOST OF VT. MAX TEMPS IN THE UPPER 70S TO AROUND 80 IN THE VALLEYS AND MID 60S TO LOW 70S OVER THE HIGHER TERRAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... AS OF 455 AM EDT THURSDAY...AS THE SUN SETS...INSTABILITY AND THEREFORE SHOWERS WILL DISSIPATE THIS EVENING. CLOUDS WILL CONTINUE TO INCREASE AS MOISTURE CONTINUES TO FILTER IN FROM THE SOUTHERLY FLOW. OVERNIGHT MIN TEMPS WILL BE IN THE LOW 60S IN THE VALLEYS AND REACHING THE MID 40S IN THE HIGHER TERRAIN. A COLD FRONT WILL APPROACH FROM THE GREAT LAKES REGION ON FRIDAY. GFS SLIGHTLY FASTER SOLUTION WITH BEST DEFORMATION OVER WESTERN NY BY 18Z. NAM A FEW HOURS SLOWER...BUT BOTH MODELS SHOW DEFORMATION WASHING OUT OVER EASTERN NY/SOUTHERN VT FRIDAY EVENING INTO SATURDAY MORNING. THIS COLD FRONT WILL BE ACCOMPANIED BY A MID LEVEL JET ENTRANCE REGION AT 850MB AND 700MB IN SOUTHEASTERN ONTARIO STRETCHING NORTHEAST INTO QUEBEC. CAN EXPECT SHOWERS AND THUNDERSTORMS TO AHEAD AND ACCOMPANYING THE COLD FRONT AS SOUTHERLY FLOW AHEAD OF THE FRONT CONTINUES TO BRING WARM MOIST AIR INTO THE REGION...AS NOTED BY SFC DEWPOINTS IN THE 60S. AS AN UPPER LEVEL TROF APPROACHES THE NORTHEAST...WIND SHEAR WILL INCREASE WITH BEST VALUES BETWEEN 25-30 KNOTS OF 0-3KM SHEAR AND 30-35 KTS OF 0-6 KM SHEAR. THIS MODEST SHEAR COMBINED WITH CAPE VALUES BETWEEN 1000 AND 2000 J/KG SUPPORT SCATTERED CONVECTION ALONG THE BOUNDARY WITH A FEW STRONGER STORMS. NOT ANTICIPATING A WIDESPREAD SEVERE WEATHER EVENT...BUT A FEW STRONGER STORMS WITH GUSTY WINDS AND DIME SIZE HAIL WILL BE POSSIBLE. SHOWERS AND THUNDERSTORM WILL CONTINUE INTO FRIDAY EVENING BEFORE THE FRONT MOVES THROUGH THE EASTERN EDGE OF THE FORECAST AREA AFTER MIDNIGHT. SATURDAY WILL SEE DRIER CONDITIONS BEHIND THE FRONT AS HIGH PRESSURE BUILDS IN OVER EASTERN ONTARIO/WESTERN QUEBEC. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 521 AM EDT THURSDAY...A RIDGE OF HIGH PRESSURE WILL BE OVER THE REGION SATURDAY NIGHT THROUGH SUNDAY NIGHT...WITH FAIR AND DRY WEATHER EXPECTED. A FRONTAL SYSTEM JUST SOUTH OF THE REGION SUNDAY NIGHT WILL BEGIN TO MOVE SLOWLY NORTHEAST AS A WARM FRONT ON MONDAY. EXPECTING SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS THE REGION MONDAY AFTERNOON AND CONTINUING INTO MONDAY NIGHT AND TUESDAY. A COLD FRONT WILL THEN MOVE THROUGH THE REGION TUESDAY NIGHT WITH A CHANCE FOR SOME MORE SHOWERS AND THUNDERSTORMS. EXPECTING COOLER TEMPERATURES ALONG WITH CLOUD COVER LINGERING ACROSS THE REGION ON WEDNESDAY...SO HAVE KEPT IN SLIGHT CHANCE POPS FOR SHOWERS ON WEDNESDAY. TEMPERATURE FORECAST FOR MONDAY AND TUESDAY COULD BE A BIT TRICKY AND WILL DEPEND ON WHERE THIS SLOW MOVING WARM FRONT WILL BE ACROSS THE REGION ON THESE DAYS. HAVE LEANED TOWARD ENSEMBLE MOS MEANS FOR MAX AND MIN TEMPERATURES ON MONDAY AND TUESDAY. && .AVIATION /16Z THURSDAY THROUGH MONDAY/... THROUGH 12Z FRIDAY...MAINLY VFR CONDITIONS EXPECTED THROUGH THE PERIOD...EXCEPT FOR SOME AREAS OF MVFR/IFR IN FOG AND MIST EARLY THIS MORNING. EXPECTING AND FOG OR MIST WILL BURN OFF BY 14Z THURSDAY. VISIBLE SATELLITE LOOP SHOWING LOW STRATUS CLOUDS ACROSS EASTERN VERMONT AS OF 1130Z THURSDAY. THESE LOWER CEILINGS MAY NOT LIFT UNTIL 16-17Z THURSDAY. GUIDANCE SHOWING SOME STEEP LOW LEVEL LAPSE RATES TO DEVELOP ACROSS THE REGION TODAY...SO THERE COULD BE SOME ISOLATED SHOWERS AND A POSSIBLE THUNDERSTORMS THIS AFTERNOON. HAVE NOT INCLUDED ANY MENTION IN THE TAFS AT THIS TIME...DUE TO LOCALIZED NATURE OF THIS. SURFACE PRESSURE GRADIENT TO TIGHTEN ACROSS THE REGION TODAY...WITH SURFACE WINDGUSTS OF AROUND 20 KNOTS OR GREATER POSSIBLE BETWEEN 14Z-17Z THURSDAY AND CONTINUING UNTIL 00Z FRIDAY. EXPECTING SURFACE WINDS TO DIMINISH TO LESS THAN 10 KNOTS AFTER 00Z FRIDAY. EXPECTING SOME MORE AREAS OF IFR/MVFR CEILINGS IN FOG AND MIST...MAINLY AFTER 04Z FRIDAY...ESPECIALLY ACROSS EASTERN VERMONT. OUTLOOK 06Z FRIDAY THROUGH MONDAY... 06Z FRIDAY THROUGH 18Z FRIDAY...GENERALLY VFR UNDER RIDGE OF HIGH PRESSURE...WITH MORNING FOG/BR POSSIBLE. 18Z FRIDAY THROUGH 18Z MONDAY...GENERALLY VFR. 18Z MONDAY THROUGH 00Z TUESDAY CHANCES FOR MVFR IN SCATTERED SHOWERS/TSTORMS AS A WARM FRONT LIFTS SLOWLY NORTHEAST ACROSS THE REGION. && .MARINE... A LAKE WIND ADVISORY IS NOW IN EFFECT THIS AFTERNOON INTO TONIGHT FOR LAKE CHAMPLAIN. SOUTH WINDS AT COLCHESTER REEF LATE THIS MORNING HAVE INCREASED TO NEAR 20 KNOTS...AND LOCAL BTV WRF MODELS SHOW SOUTHERLY FLOW INCREASING TO AROUND 25 KNOTS THIS AFTERNOON. EXPECT SOUTH WINDS TO BE IN THE 15 TO 25 KNOT RANGE WITH 2 FOOT WAVES ACROSS THE BROAD LAKE. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...KGM/TABER NEAR TERM...KGM/TABER SHORT TERM...KGM LONG TERM...WGH AVIATION...WGH MARINE...LOCONTO