Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/11/15


AREA FORECAST DISCUSSION
NWS ALBANY NY
151 PM EDT THU APR 9 2015 .SYNOPSIS... A WARM FRONT WILL BEGIN TO MOVE NORTH OF THE OHIO VALLEY AND THE MID ATLANTIC REGION TODAY INTO TONIGHT. THIS WILL KEEP THE CLOUDS ALONG WITH SOME LIGHT RAIN SHOWERS AND DRIZZLE TODAY WITH A STEADIER RAINFALL EXPECTED TONIGHT. A MILDER AIR MASS WILL BE ACROSS THE REGION BY FRIDAY AS THE WARM FRONT MOVES THROUGH...AND A COLD FRONT WILL BRING SHOWERS AND A SLIGHT CHANCE FOR THUNDERSTORMS LATE FRIDAY MORNING AND INTO THE AFTERNOON HOURS. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 130 PM EDT...THE PATCHY DRIZZLE AND FREEZING DRIZZLE HAS DIMINISHED ACROSS THE FCST AREA. IT IS STILL A VERY COOL AND DAMP AIR MASS WITH TEMPS RUNNING ABOUT 15 T0 20 DEGREES BELOW NORMAL. SOME PATCHY DRIZZLE WAS KEPT IN THE FCST AREA WRN NEW ENGLAND AND THE SRN DACKS IN THE MID TO LATE PM. THE SPS FOR SPOTTY FREEZING DRIZZLE ESPECIALLY OVER THE HIGHER TERRAIN WILL END AT 2 PM. A WARM FRONT WILL BEGIN LIFTING N/NE FROM OH AND THE MID ATLANTIC REGION LATE THIS AFTERNOON INTO TONIGHT. MAX TEMPS WILL GENERALLY BE IN THE 30S TO L40S FOR THE REST OF THE DAY...AND STEADY OF SLOWLY RISE INTO TONIGHT. THE LATEST HRRR HAS THE NEXT BATCH OF PCPN MOVING IN BETWEEN 00Z-03Z WITH THE SHORT-WAVE IN THE SW FLOW AND THE STRENGTHENING WARM ADVECTION. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... TONIGHT...THE WARM FRONT QUICKLY LIFTS N/NE FROM THE LOWER GREAT LAKES REGION AND PA ACROSS UPSTATE NY AND NEW ENGLAND AS THE CENTER OF LOW PRESSURE TRACKS FROM THE MID MISSISSIPPI RIVER VALLEY INTO THE CENTRAL GREAT LAKES REGION. THIS STORM WILL INTENSIFY OVERNIGHT AS THE UPPER TROUGH BECOMES NEUTRAL TO NEGATIVELY TILTED. EXPECT PERIODS OF RAIN AS MOIST LOW LEVEL JET INCREASES WITH DEEP ISENTROPIC LIFT. THERE MAY BE A RUMBLE OF THUNDER AROUND WEST AND SOUTH OF ALBANY AS THE SHOWALTER VALUES FALLING CLOSE TO 0C TO -1C. LOWS THU NIGHT WILL RANGE FROM THE U30S TO L40S ACROSS MOST THE REGION. SOME MELTING OF THE SNOW PACK...ESPECIALLY OVER THE HIGHER TERRAIN IS EXPECTED. TOTAL RAIN AMOUNTS LATE THU PM INTO FRI MORNING WILL BE IN THE QUARTER TO THREE QUARTERS INCH RANGE WITH THE HIGHER TALLIES OVER THE SRN DACKS. FRIDAY...COLD FRONT WILL MOVE ACROSS THE REGION THROUGH THE MORNING AND INTO THE MID AFTERNOON HOURS. SHOWALTER VALUES DROP ACROSS THE REMAINDER OF THE REGION TO VALUES AROUND 0C. THIS ALONG WITH COLLABORATION WITH SPC...WE WILL CONTINUE WITH THE MENTION OF THUNDER IN THE FORECAST/GRIDS. HIGHS IN THE LOWER AND M60S IN MOST OF THE VALLEY AREAS /A FEW U60S OVER THE MID HUDSON VALLEY/...AND M50S TO L60S OVER THE HILLS AND MTNS. FRIDAY NIGHT...COLD ADVECTION OCCURS IN THE WAKE OF THE FRONT WITH PRETTY GOOD SUBSIDENCE TO END MOST OF THE PCPN FOR THE FCST AREA...THOUGH A FEW UPSLOPE RAIN TO SNOW SHOWERS ARE POSSIBLE OVER THE WRN DACKS. LOWS WILL BE IN THE M30S TO L40S IN MOST LOCATIONS WITH A FEW U20S TO L30S OVER THE SRN DACKS. SATURDAY...THE MAIN UPPER TROUGH AXIS AND SECONDARY COLD FRONT WILL CROSS THE REGION. THE BEST MOISTURE PROFILES AND FAVORABLE UPSLOPE CONDITIONS WILL EXIST ACROSS THE DACKS WHERE THE POPS WILL BE HIGHER THAN THE REMAINDER OF THE TERRAIN LOCATIONS. A BRISK DAY IS EXPECTED TOO AS SURFACE GRADIENT WILL BE TIGHT AND MIXING LAYER HEIGHTS SUGGEST WE MAY TAP INTO THE MID-UPR 30KTS. AS THE H850 TEMPS FALL BACK BELOW 0C...THIS TOO WILL BE REFLECTIVE WITH FORECAST SURFACE TEMPERATURES WITH MAINLY 40S ACROSS THE TERRAIN AND LOWER HALF OF THE 50S FOR VALLEY LOCATIONS. THIS WOULD BE A COUPLE DEGREES BELOW NORMAL AS WE ARE FAST APPROACHING THE MIDDLE OF THE MONTH. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... MUCH OF THE LONG TERM PERIOD WILL FEATURE SLIGHTLY ABOVE NORMAL TEMPERATURES. PRECIPITATION IS MORE UNCERTAIN...BUT LATEST GUIDANCE SEEMS TO FAVOR NEAR TO BELOW NORMAL AMTS. STARTING WITH SUNDAY...RIDGING IS EXPECTED TO TRANSLATE ACROSS THE REGION FROM THE WEST. THIS SHOULD ALLOW FOR GENERALLY SUNNY SKIES...WITH MAX TEMPS REACHING THE UPPER 50S TO LOWER 60S IN MOST VALLEYS...WITH 40S TO LOWER 50S ACROSS HIGHER ELEVATIONS. WINDS MAY BE A BIT BRISK FROM THE WEST...ESP IN THE MORNING. A GENERALLY ZONAL FLOW IS THEN EXPECTED TO PREDOMINATE FOR MON-TUE WITH A FAST MOVING DISTURBANCE EXPECTED TO PASS NORTH OF THE REGION MON NT-EARLY TUE. THIS MAY BRING A PERIOD OF SHOWERS FOR MON AFTERNOON-NIGHT...ESP ACROSS NORTHERN AREAS. THIS SYSTEM APPEARS RATHER PROGRESSIVE...SO EXPECT GENERALLY FAIR WEATHER TO RETURN BY TUESDAY. FOR LATE TUE-THU...MODELS EXHIBIT A BIT MORE UNCERTAINTY REGARDING ADDITIONAL SHORTWAVE ENERGY APPROACHING FROM THE CENTRAL U.S...AND LINGERING TROUGHING ACROSS THE EASTERN CANADA. THE BULK OF THE 00Z/09 GUIDANCE SEEMS TO FAVOR ENOUGH RIDGING BETWEEN THESE FEATURES TO ALLOW FOR GENERALLY DRY CONDITIONS FROM LATE TUE INTO AT LEAST MUCH OF WED. HOWEVER...SOME 00Z/09 GEFS MEMBERS SEEM TO ALLOW FOR A WEAKER RIDGE AND MORE UPPER LEVEL ENERGY EJECTING EAST...INCREASING THE CHANCES FOR SHOWERS. AT THIS TIME...HAVE SIDED ON THE DRIER SIDE THROUGH WED WITH JUST SOME SLIGHT CHC POPS ACROSS SOUTHERN AREAS...TO ACCOUNT FOR THE POSSIBILITY THAT SOME ENERGY/MOISTURE APPROACHES A BIT FASTER FROM THE SOUTHWEST. AS FOR TEMPS...EXPECT DAYTIME MAXES TO REACH THE LOWER/MID 60S IN VALLEYS...AND 50S ACROSS HIGHER ELEVATIONS. THERE IS THE POSSIBILITY OF EVEN WARMER MAX TEMPS COULD OCCUR IN VALLEY AREAS ASSUMING DEEPER MIXING OCCURS. OVERNIGHT MIN TEMPS SHOULD FALL INTO THE 30S TO LOWER 40S. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... MVFR CEILINGS WILL PREVAIL AT THE TAF SITES THIS AFTERNOON...BEFORE A RETURN TO MVFR/IFR FLYING CONDITIONS ASSOCIATED WITH RAIN ALONG A WARM FRONT. THIS AFTERNOON...MVFR CEILINGS WILL CONTINUE AT THE TAF SITES WITH PLENTY OF LOW-LEVEL MOISTURE IN PLACE. AFTER 20Z...CEILINGS MAY BRIEFLY RISE TO VFR...BUT GIVEN STRONG LOW-LEVEL INVERSION IN PLACE TRAPPING MOISTURE AND LIMITING MIXING...HAVE SIDED WITH MVFR CEILINGS THROUGH 00Z. WINDS WILL BE OUT OF THE EAST/SOUTHEAST GENERALLY BETWEEN 5-10 KNOTS. TONIGHT INTO FRIDAY...CHANCES FOR RAIN WILL RAPIDLY INCREASE AFTER 00Z AS A WARM FRONT LIFTS NORTH ACROSS THE REGION AND AN AREA OF LOW PRESSURE APPROACHES FROM THE LOWER GREAT LAKES. EXPECT MVFR CEILINGS AND VISIBILITIES AT THE TAF SITES WITH OCCASIONAL DRIZZLE BETWEEN 00Z-03Z...WITH A TEMPO GROUP FOR POSSIBLE IFR CEILINGS AT KPSF. BY 03Z...EXPECT RAIN TO OVERSPREAD THE TAF SITES AND CONTINUE THROUGH 12Z...WITH PERIODS OF HEAVIER RAIN ASSOCIATED WITH STRONGER SHOWERS. THUNDER MAY BE POSSIBLE AT THE TAF SITES...BUT HAVE LEFT MENTION OUT OF THIS TAF ISSUANCE FOR NOW AS CONFIDENCE IS LOW AT THIS TIME. HAVE LOWERED CEILINGS AT THE TAF SITES TO IFR BEGINNING AT 03Z...WITH BORDERLINE MVFR/IFR VISIBILITIES EXPECTED. RAIN SHOULD BECOME MORE SHOWERY IN NATURE AFTER 12Z AND LINGER ACROSS THE REGION THROUGH THE REMAINDER OF THE TAF PERIOD WITH FLYING CONDITIONS IMPROVING SLIGHTLY TO MVFR...WITH IFR CEILINGS PERSISTING UNTIL 14Z AT KPSF. WINDS WILL SHIFT TO THE SOUTH/SOUTHEAST TONIGHT AND STRENGTHEN SLIGHTLY TO AROUND 10 KNOTS...WITH HIGHER GUSTS OF AROUND 20 KNOTS ASSOCIATED WITH ANY STRONG SHOWER ACTIVITY. HAVE INCLUDED LLWS AT KALB...KGFL AND KPOU FROM 06Z-12Z WITH AROUND 40 KNOTS OF WIND AROUND 2000 FT ABOVE A STRONG SURFACE-BASED INVERSION. HAVE LEFT LLWS OUT OF KPSF FOR NOW AS SLIGHTLY BETTER MIXING MAY OCCUR DUE TO THE TAF SITE BEING LOCATED NEAR THE TOP OF THE INVERSION. OUTLOOK... FRIDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY SLIGHT CHANCE OF SHRA. SATURDAY: MODERATE OPERATIONAL IMPACT. WINDY. NO SIG WX. SATURDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY NO SIG WX. SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. MONDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... NO FIRE WEATHER CONCERNS ANTICIPATED THROUGH THE REST OF THE WORK WEEK DUE TO EXPECTED WET AND UNSETTLED CONDITIONS AND MAINLY COOL WEATHER. DRIER WEATHER IS EXPECTED FROM LATER SATURDAY INTO SUNDAY. && .HYDROLOGY... UNSETTLED AND COOL WEATHER IS EXPECTED THROUGH MUCH OF THE REST OF THE WORK WEEK. A WARM FRONT IS EXPECTED TO LIFT BACK NORTH THURSDAY NIGHT INTO FRIDAY...RESULTING IN A WARMUP WITH A CONTINUED THREAT FOR RAIN AND EVEN A SLIGHT CHANCE OF THUNDERSTORMS ON FRIDAY. SNOW MELT COMBINING WITH PRECIPITATION THE PAST 24 HOURS RESULTED IN THE MOHAWK RIVER EXPERIENCING WITHIN BANK RISES OVERNIGHT. HOWEVER...A MORE SIGNIFICANT WARMUP IS EXPECTED ON FRIDAY...WHICH IS WHEN MORE RAPID SNOW MELT IS EXPECTED. LATEST MMEFS /ENSEMBLE GUIDANCE/ INDICATES RIVER LEVELS WILL RISE BY EARLY IN THE WEEKEND...WITH SEVERAL POINTS POTENTIALLY APPROACHING ACTION STAGE BUT NO FLOODING AT THIS TIME. ONLY THE SACANDAGA RIVER AT HOPE HAS A LOW PROBABILITY FORECAST TO REACH MINOR FLOOD STAGE. WE WILL CONTINUE TO WATCH THE POTENTIAL FOR RIVER RISES OVER THE NEXT SEVERAL DAYS. NONE THE NERFC FORECASTS HAVE ANY POINTS REACHING FLOOD STAGE THE NEXT FEW DAYS. TOTAL QPF THROUGH THURSDAY NIGHT MAY EXCEED A HALF AN INCH ESPECIALLY ACROSS NORTHERN AREAS /ADIRONDACK REGION/. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...BGM/WASULA NEAR TERM...JPV/WASULA SHORT TERM...BGM/WASULA LONG TERM...KL/JPV AVIATION...IRL FIRE WEATHER...BGM/WASULA HYDROLOGY...BGM/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
130 PM EDT THU APR 9 2015 .SYNOPSIS... A WARM FRONT WILL BEGIN TO MOVE NORTH OF THE OHIO VALLEY AND THE MID ATLANTIC REGION TODAY INTO TONIGHT. THIS WILL KEEP THE CLOUDS ALONG WITH SOME LIGHT RAIN SHOWERS AND DRIZZLE TODAY WITH A STEADIER RAINFALL EXPECTED TONIGHT. A MILDER AIR MASS WILL BE ACROSS THE REGION BY FRIDAY AS THE WARM FRONT MOVES THROUGH...AND A COLD FRONT WILL BRING SHOWERS AND A SLIGHT CHANCE FOR THUNDERSTORMS LATE FRIDAY MORNING AND INTO THE AFTERNOON HOURS. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 130 PM EDT...THE PATCHY DRIZZLE AND FREEZING DRIZZLE HAS DIMINISHED ACROSS THE FCST AREA. IT IS STILL A VERY COOL AND DAMP AIR MASS WITH TEMPS RUNNING ABOUT 15 T0 20 DEGREES BELOW NORMAL. SOME PATCHY DRIZZLE WAS KEPT IN THE FCST AREA WRN NEW ENGLAND AND THE SRN DACKS IN THE MID TO LATE PM. THE SPS FOR SPOTTY FREEZING DRIZZLE ESPECIALLY OVER THE HIGHER TERRAIN WILL END AT 2 PM. A WARM FRONT WILL BEGIN LIFTING N/NE FROM OH AND THE MID ATLANTIC REGION LATE THIS AFTERNOON INTO TONIGHT. MAX TEMPS WILL GENERALLY BE IN THE 30S TO L40S FOR THE REST OF THE DAY...AND STEADY OF SLOWLY RISE INTO TONIGHT. THE LATEST HRRR HAS THE NEXT BATCH OF PCPN MOVING IN BETWEEN 00Z-03Z WITH THE SHORT-WAVE IN THE SW FLOW AND THE STRENGTHENING WARM ADVECTION. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... TONIGHT...THE WARM FRONT QUICKLY LIFTS N/NE FROM THE LOWER GREAT LAKES REGION AND PA ACROSS UPSTATE NY AND NEW ENGLAND AS THE CENTER OF LOW PRESSURE TRACKS FROM THE MID MISSISSIPPI RIVER VALLEY INTO THE CENTRAL GREAT LAKES REGION. THIS STORM WILL INTENSIFY OVERNIGHT AS THE UPPER TROUGH BECOMES NEUTRAL TO NEGATIVELY TILTED. EXPECT PERIODS OF RAIN AS MOIST LOW LEVEL JET INCREASES WITH DEEP ISENTROPIC LIFT. THERE MAY BE A RUMBLE OF THUNDER AROUND WEST AND SOUTH OF ALBANY AS THE SHOWALTER VALUES FALLING CLOSE TO 0C TO -1C. LOWS THU NIGHT WILL RANGE FROM THE U30S TO L40S ACROSS MOST THE REGION. SOME MELTING OF THE SNOW PACK...ESPECIALLY OVER THE HIGHER TERRAIN IS EXPECTED. TOTAL RAIN AMOUNTS LATE THU PM INTO FRI MORNING WILL BE IN THE QUARTER TO THREE QUARTERS INCH RANGE WITH THE HIGHER TALLIES OVER THE SRN DACKS. FRIDAY...COLD FRONT WILL MOVE ACROSS THE REGION THROUGH THE MORNING AND INTO THE MID AFTERNOON HOURS. SHOWALTER VALUES DROP ACROSS THE REMAINDER OF THE REGION TO VALUES AROUND 0C. THIS ALONG WITH COLLABORATION WITH SPC...WE WILL CONTINUE WITH THE MENTION OF THUNDER IN THE FORECAST/GRIDS. HIGHS IN THE LOWER AND M60S IN MOST OF THE VALLEY AREAS /A FEW U60S OVER THE MID HUDSON VALLEY/...AND M50S TO L60S OVER THE HILLS AND MTNS. FRIDAY NIGHT...COLD ADVECTION OCCURS IN THE WAKE OF THE FRONT WITH PRETTY GOOD SUBSIDENCE TO END MOST OF THE PCPN FOR THE FCST AREA...THOUGH A FEW UPSLOPE RAIN TO SNOW SHOWERS ARE POSSIBLE OVER THE WRN DACKS. LOWS WILL BE IN THE M30S TO L40S IN MOST LOCATIONS WITH A FEW U20S TO L30S OVER THE SRN DACKS. SATURDAY...THE MAIN UPPER TROUGH AXIS AND SECONDARY COLD FRONT WILL CROSS THE REGION. THE BEST MOISTURE PROFILES AND FAVORABLE UPSLOPE CONDITIONS WILL EXIST ACROSS THE DACKS WHERE THE POPS WILL BE HIGHER THAN THE REMAINDER OF THE TERRAIN LOCATIONS. A BRISK DAY IS EXPECTED TOO AS SURFACE GRADIENT WILL BE TIGHT AND MIXING LAYER HEIGHTS SUGGEST WE MAY TAP INTO THE MID-UPR 30KTS. AS THE H850 TEMPS FALL BACK BELOW 0C...THIS TOO WILL BE REFLECTIVE WITH FORECAST SURFACE TEMPERATURES WITH MAINLY 40S ACROSS THE TERRAIN AND LOWER HALF OF THE 50S FOR VALLEY LOCATIONS. THIS WOULD BE A COUPLE DEGREES BELOW NORMAL AS WE ARE FAST APPROACHING THE MIDDLE OF THE MONTH. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... MUCH OF THE LONG TERM PERIOD WILL FEATURE SLIGHTLY ABOVE NORMAL TEMPERATURES. PRECIPITATION IS MORE UNCERTAIN...BUT LATEST GUIDANCE SEEMS TO FAVOR NEAR TO BELOW NORMAL AMTS. STARTING WITH SUNDAY...RIDGING IS EXPECTED TO TRANSLATE ACROSS THE REGION FROM THE WEST. THIS SHOULD ALLOW FOR GENERALLY SUNNY SKIES...WITH MAX TEMPS REACHING THE UPPER 50S TO LOWER 60S IN MOST VALLEYS...WITH 40S TO LOWER 50S ACROSS HIGHER ELEVATIONS. WINDS MAY BE A BIT BRISK FROM THE WEST...ESP IN THE MORNING. A GENERALLY ZONAL FLOW IS THEN EXPECTED TO PREDOMINATE FOR MON-TUE WITH A FAST MOVING DISTURBANCE EXPECTED TO PASS NORTH OF THE REGION MON NT-EARLY TUE. THIS MAY BRING A PERIOD OF SHOWERS FOR MON AFTERNOON-NIGHT...ESP ACROSS NORTHERN AREAS. THIS SYSTEM APPEARS RATHER PROGRESSIVE...SO EXPECT GENERALLY FAIR WEATHER TO RETURN BY TUESDAY. FOR LATE TUE-THU...MODELS EXHIBIT A BIT MORE UNCERTAINTY REGARDING ADDITIONAL SHORTWAVE ENERGY APPROACHING FROM THE CENTRAL U.S...AND LINGERING TROUGHING ACROSS THE EASTERN CANADA. THE BULK OF THE 00Z/09 GUIDANCE SEEMS TO FAVOR ENOUGH RIDGING BETWEEN THESE FEATURES TO ALLOW FOR GENERALLY DRY CONDITIONS FROM LATE TUE INTO AT LEAST MUCH OF WED. HOWEVER...SOME 00Z/09 GEFS MEMBERS SEEM TO ALLOW FOR A WEAKER RIDGE AND MORE UPPER LEVEL ENERGY EJECTING EAST...INCREASING THE CHANCES FOR SHOWERS. AT THIS TIME...HAVE SIDED ON THE DRIER SIDE THROUGH WED WITH JUST SOME SLIGHT CHC POPS ACROSS SOUTHERN AREAS...TO ACCOUNT FOR THE POSSIBILITY THAT SOME ENERGY/MOISTURE APPROACHES A BIT FASTER FROM THE SOUTHWEST. AS FOR TEMPS...EXPECT DAYTIME MAXES TO REACH THE LOWER/MID 60S IN VALLEYS...AND 50S ACROSS HIGHER ELEVATIONS. THERE IS THE POSSIBILITY OF EVEN WARMER MAX TEMPS COULD OCCUR IN VALLEY AREAS ASSUMING DEEPER MIXING OCCURS. OVERNIGHT MIN TEMPS SHOULD FALL INTO THE 30S TO LOWER 40S. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... A WARM FRONT WILL SLOWLY APPROACH FROM THE SOUTHWEST LATER TODAY AND TONIGHT. AHEAD OF THIS FRONT...A COOL AND MOIST AIRMASS WILL REMAIN IN PLACE...WITH SPOTTY AREAS OF DRIZZLE. SOME POCKETS OF FREEZING DRIZZLE WILL REMAIN POSSIBLE THROUGH 14Z/THU AT KPSF. FLIGHT CONDITIONS WILL BE MAINLY MVFR THROUGH MOST OF TODAY. HOWEVER...IFR CIGS/VSBYS WILL LIKELY LINGER AT KALB THROUGH AROUND 15Z-17Z/THU. OCCASIONAL IFR...ESP FOR CIGS...AT KPSF THROUGH AROUND 14Z/THU. ADDITIONAL...MORE WIDESPREAD IFR CONDITIONS WILL BECOME POSSIBLE LATER TONIGHT AS THE WARM FRONT APPROACHES. AS FOR PRECIPITATION CHANCES...IT APPEARS THAT LITTLE IF ANY SIGNIFICANT PRECIPITATION OTHER THAN DRIZZLE IS EXPECTED THROUGH MUCH OF TODAY. THEN...RAIN SHOWERS WILL BECOME POSSIBLE LATER THIS AFTERNOON...MAINLY AFTER 00Z/THU...WITH OCCASIONAL RAIN SHOWERS EXPECTED INTO MUCH OF TONIGHT. WINDS WILL THEN TREND INTO THE EAST TO SOUTHEAST TODAY AND INCREASE TO 8-12 KT AND SHOULD CONTINUE INTO TONIGHT. SOME SLIGHTLY STRONGER GUSTS OF UP TO 20-25 KT COULD OCCUR THIS AFTERNOON AND EVENING. OUTLOOK... FRIDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY SLIGHT CHANCE OF SHRA. SATURDAY: MODERATE OPERATIONAL IMPACT. WINDY. NO SIG WX. SATURDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY NO SIG WX. SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. MONDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... NO FIRE WEATHER CONCERNS ANTICIPATED THROUGH THE REST OF THE WORK WEEK DUE TO EXPECTED WET AND UNSETTLED CONDITIONS AND MAINLY COOL WEATHER. DRIER WEATHER IS EXPECTED FROM LATER SATURDAY INTO SUNDAY. && .HYDROLOGY... UNSETTLED AND COOL WEATHER IS EXPECTED THROUGH MUCH OF THE REST OF THE WORK WEEK. A WARM FRONT IS EXPECTED TO LIFT BACK NORTH THURSDAY NIGHT INTO FRIDAY...RESULTING IN A WARMUP WITH A CONTINUED THREAT FOR RAIN AND EVEN A SLIGHT CHANCE OF THUNDERSTORMS ON FRIDAY. SNOW MELT COMBINING WITH PRECIPITATION THE PAST 24 HOURS RESULTED IN THE MOHAWK RIVER EXPERIENCING WITHIN BANK RISES OVERNIGHT. HOWEVER...A MORE SIGNIFICANT WARMUP IS EXPECTED ON FRIDAY...WHICH IS WHEN MORE RAPID SNOW MELT IS EXPECTED. LATEST MMEFS /ENSEMBLE GUIDANCE/ INDICATES RIVER LEVELS WILL RISE BY EARLY IN THE WEEKEND...WITH SEVERAL POINTS POTENTIALLY APPROACHING ACTION STAGE BUT NO FLOODING AT THIS TIME. ONLY THE SACANDAGA RIVER AT HOPE HAS A LOW PROBABILITY FORECAST TO REACH MINOR FLOOD STAGE. WE WILL CONTINUE TO WATCH THE POTENTIAL FOR RIVER RISES OVER THE NEXT SEVERAL DAYS. NONE THE NERFC FORECASTS HAVE ANY POINTS REACHING FLOOD STAGE THE NEXT FEW DAYS. TOTAL QPF THROUGH THURSDAY NIGHT MAY EXCEED A HALF AN INCH ESPECIALLY ACROSS NORTHERN AREAS /ADIRONDACK REGION/. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...BGM/WASULA NEAR TERM...JPV/WASULA SHORT TERM...BGM/WASULA LONG TERM...KL/JPV AVIATION...KL/JPV FIRE WEATHER...BGM/WASULA HYDROLOGY...BGM/WASULA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
925 PM EDT FRI APR 10 2015 .SYNOPSIS... LOW PRESSURE MOVING THROUGH SOUTHERN QUEBEC WILL DRAG A COLD FRONT THROUGH OUR REGION TONIGHT. HIGH PRESSURE WILL BUILD IN OVER THE WEEKEND AND MOVE OFFSHORE ON MONDAY. A COLD FRONT WILL CROSS THE AREA ON TUESDAY. ANOTHER HIGH PRESSURE SYSTEM WILL BUILD IN DURING THE MIDDLE OF THE WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... A COLD FRONT EXTENDED FROM EASTERN NEW YORK, ACROSS EASTERN PENNSYLVANIA TO CENTRAL VIRGINIA AROUND 900 PM. THE BOUNDARY WILL MAKE ITS WAY EASTWARD THROUGH OUR REGION DURING THE BALANCE OF THE EVENING HOURS. IT IS NOT A CLEAN COLD FRONTAL PASSAGE. THE AIR THAT IS BEING DISPLACED IN MUCH OF OUR REGION IS COOLER THAN THE AIR BEHIND THE COLD FRONT. REGARDLESS, WE ARE EXPECTING CLEARING AND A SHIFT TO A WEST NORTHWEST WIND THROUGHOUT ALL OF EASTERN PENNSYLVANIA, NORTHEASTERN MARYLAND, DELAWARE AND NEW JERSEY BY MIDNIGHT. THE SHOWERS AND SCATTERED THUNDERSTORMS IN THE FAR SOUTHEASTERN PART OF OUR FORECAST AREA WILL CONTINUE TO DRIFT OUT TO SEA. WE WILL MENTION THEM IN THE FORECAST FOR THOSE AREAS UNTIL ABOUT MIDNIGHT BASED ON THE LATEST HRRR GUIDANCE. TEMPERATURES WERE MAINLY IN THE 50S IN OUR REGION AT 900 PM, WITH SOME READINGS IN THE 60S IN THE FAR SOUTHEAST. WE ANTICIPATE THAT TEMPERATURES WILL FALL INTO THE 40S AT MOST LOCATIONS OVERNIGHT. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/... ONLY IN THE SPRING IN THE NORTHEAST CAN ONE TYPE: NOW THAT THE COLD FRONT HAS PASSED, A WARMER DAY IS IN STORE. THIS WILL BE TRUE FOR THE NORTHWEST PART OF OUR CWA. THE SERN PART OF OUR CWA WILL HAVE A COOLER DAY. BUT ALL SHOULD EXPERIENCE A BRISK NORTHWEST FLOW AND SOME SUNSHINE. THERE WILL BE A SHORT WAVE TROF PASSING ACROSS OUR CWA. CUMULUS CLOUDS WILL FORM AND COVERAGE MIGHT GET ON THE CLOUDIER SIDE IN THE NORTHERN PART OF OUR CWA DURING THE AFTERNOON. PREDICTED MOISTURE AND HEIGHT SHOULD NOT BE ENOUGH TO GENERATE PCPN OR SPRINKLES. SOUNDING FULL SUNS ARE SUGGESTING MAX TEMPS BLO STAT GUIDANCE, BUT THIS HAS NOT WORKED WELL THIS SPRING IN NW FLOW REGIMES. WE REMAINED CLOSE TO CONTINUITY AND 12Z STAT GUIDANCE. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... OVERVIEW... MID-LEVEL SHORTWAVE TROUGH EXITS THE NORTHEAST CONUS AT THE BEGINNING OF THE LONG TERM PORTION OF THE FORECAST SUN NIGHT. THIS IS FOLLOWED BY A TRANSITORY RIDGE CRESTING OVER THE AREA ON MON. MODELS BEGIN TO DIVERGE THEREAFTER BEGINNING AROUND 00Z TUE WITH RESPECT TO /WRT/ TWO MAIN FEATURES...A S/WV TROUGH MOVING THRU THE NORTHEAST CONUS AROUND 00Z WED AND A DEEPER LONG WAVE TROUGH PROGGED INVOF THE MS VALLEY AROUND 00Z FRI. THE UNCERTAINTY WRT TO THE NORTHEAST CONUS TROUGH IS DUE TO A BLOCKY PATTERN DEVELOPING DOWNSTREAM OVER THE NORTH ATLANTIC OCEAN. THIS LEADS TO SPREAD IN THE LOCATION OF THE MID-LEVEL TROUGH AXIS...AND THUS SOME UNCERTAINTY REGARDING A COLD FROPA MON NIGHT INTO TUE. MOREOVER...THE GENERAL TREND HAS BEEN TO SLOW THE FROPA...WHICH MAKES SENSE GIVEN THE PATTERN. THUS A MORE PESSIMISTIC FORECAST IS IN THE CARDS FOR TUESDAY. THEREAFTER...ATTENTION TURNS TO A LONG WAVE TROUGH/CLOSED LOW DEVELOPING INVOF THE MS VALLEY BY 00Z FRI...WHILE A CUT-OFF LOW IS PROGGED TO DEVELOP SOUTH OF NEWFOUNDLAND. BOUNDING THESE FEATURES...A MID-LEVEL RIDGE IS EXPECTED TO BE INVOF THE EAST COAST. THE AMPLITUDE AND PLACEMENT OF THIS RIDGE... LARGELY DEPENDENT ON THE AFOREMENTIONED FEATURES...IMPACTS OUR SENSIBLE WEATHER IN THE THU AND FRI TIME FRAME. THERE IS A LOT OF UNCERTAINTY AT THIS POINT IN THE FORECAST. OVERALL...THE BEST CHANCE OF PRECIP WILL BE ON MON NIGHT AND TUE AND THEN AGAIN ON THU AND FRI. TEMPERATURES ARE EXPECTED TO BE AROUND SEASONABLE LEVELS THRU THE ENTIRE LONG TERM. DAILIES... HIGH PRESSURE WILL CREST OVER THE REGION SAT NIGHT AND SUNDAY. DRY AIR MASS IN PLACE WITH MOSTLY CLEAR SKIES AND LIGHT WINDS EXPECTED. PATCHY FOG POSSIBLE SUNDAY MORNING IN THE NORMALLY PRONE LOCATIONS. IF THE GRADIENT RELAXES ENOUGH SUNDAY AFTN... SEA- BREEZES MAY DEVELOP ALONG THE COAST...KEEPING TEMPS COOLER. SURFACE FLOW BECOMES S/SW MONDAY AS HIGH PRES MOVES OFFSHORE IN ADVANCE OF NEXT COOL FRONT IN THE OHIO VALLEY. EXPECT MID AND HIGH CLOUDS TO INCREASE A BIT IN WAA ADVECTION REGIME...BUT PRECIP SHOULD REMAIN WEST OF THE CWA. MODELS CONTINUE TO SHOW THIS TREND AS WELL. MIXING TO 900 HPA YIELDS S/SW WIND GUSTS TO AROUND 25 KNOTS PER MODEL SOUNDINGS. COOL FRONT APPROACHES MON NIGHT AND IS PROGGED TO MOVE THRU THE REGION ON TUE. THE FRONT WILL HAVE GULF MOISTURE TO WORK WITH. SHOWERS AND EVEN SOME HEAVIER DOWNPOURS ARE EXPECTED DURING THIS TIME FRAME...WITH THE GREATEST PRECIP COVERAGE EXPECTED ACROSS THE NORTHERN PART OF THE CWA...WHERE THE BEST LIFTING MECHANISMS COINCIDE. CONVECTIVE POTENTIAL IS LIMITED...ESP WITH CURRENT COOL FROPA TIMING EARLY IN THE DAY...BUT CANNOT RULE OUT A RUMBLE OF THUNDER. HIGH PRESSURE SETTLES OVER THE REGION TUE NIGHT AND WED WITH FAIR WEATHER EXPECTED. COMPLEX WEATHER PATTERN SHAPING UP FOR THU AND FRI. BOTH THE 12Z/10 EURO AND GFS FEATURE HIGH PRES CENTERED OVER THE NORTHEAST CONUS AT 00Z THU...BUT BOTH MODELS THEN DIVERGE... WITH THE GFS MUCH MORE PROGRESSIVE THAN THE EURO. FAVOR THE LESS PROGRESSIVE SOLUTION ATTM GIVEN THE BLOCKY UPSTREAM PATTERN. ATTM...IT APPEARS A STATIONARY BOUNDARY/INVERTED TROUGH MAY TRY TO ESTABLISH ITSELF INVOF THE MID ATL DURING THIS TIME FRAME...LEADING TO UNSETTLED WEATHER. && .AVIATION /01Z SATURDAY THROUGH WEDNESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. THE POTENTIAL FOR IFR AND MVFR CEILINGS WILL LINGER INTO THE 03Z TO 04Z TIME FRAME AT OUR TAF SITES AS A COLD FRONT WORKS ITS WAY FROM WEST TO EAST THROUGH OUR REGION. SHOWERS AND SCATTERED THUNDERSTORMS WILL REMAIN TO THE SOUTHEAST OF OUR TAF SITES. CLEARING IS ANTICIPATED OVERNIGHT AS THE COLD FRONT BEGINS TO MOVE OFF THE COAST. VFR CONDITIONS AND A MAINLY CLEAR SKY ARE EXPECTED FOR LATE TONIGHT INTO SATURDAY. A SOUTHWEST WIND AROUND 5 TO 10 KNOTS IS FORECAST UNTIL THE COLD FRONT PASSES. THE WIND DIRECTION WILL SHIFT TO THE WEST. A NORTHWEST WIND AROUND 10 TO 15 KNOTS WITH GUSTS TO 20 OR 25 KNOTS IS ANTICIPATED FOR SATURDAY. OUTLOOK... SAT NIGHT THRU MON...VFR CONDITIONS. PATCHY FOG MAY REDUCE CEILINGS/VSBYS SUN AND MON AM. MON NIGHT THRU TUE...MVFR POSSIBLE IN SHRA WITH THE PASSAGE OF A COLD FRONT. TUE NIGHT THRU WED...VFR CONDITIONS. && .MARINE... THE SMALL CRAFT ADVISORY FOR THE OCEAN REMAINS IN EFFECT THROUGH TONIGHT. WE ARE NOT AS CONFIDENT ABOUT WINDS REACHING CRITERIA AND MIXING NEITHER TONIGHT NOR ON SATURDAY WILL BE EFFICIENT AS AIR TEMPERATURES WILL GENERALLY BE HIGHER THAN THE WATER TEMPERATURES. SEAS REMAIN AT CRITERIA AND WITH A SOUTHERLY SWELL CONTINUING INTO TONIGHT, THEY SHOULD REMAIN AROUND OR ABOVE CRITERIA. WE MIGHT NEED A SMALL CRAFT ADVISORY EXTENSION FOR THE SEAS ON SATURDAY MORNING AND WE WILL REACCESS THE WIND MIXING POTENTIAL. PREDICTED GUSTS FOR SATURDAY ARE AROUND 20 KTS. OUTLOOK... SAT NIGHT THRU MON...SUB SCA CONDITIONS EXPECTED. MON NIGHT THRU TUE...WINDS AND SEAS MAY APPROACH SCA CRITERIA. WED...WINDS AND SEAS ARE EXPECTED TO BE BELOW SCA THRESHOLDS. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ450>455. && $$ SYNOPSIS...FRANCK NEAR TERM...IOVINO SHORT TERM...GIGI LONG TERM...FRANCK AVIATION...FRANCK/IOVINO MARINE...FRANCK/GIGI
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
858 AM EDT THU APR 9 2015 .SYNOPSIS... A WEAK RIDGE OF HIGH PRESSURE ACROSS THE AREA WILL MOVE OFF TO THE EAST BY TONIGHT. LOW PRESSURE WILL MOVE INTO THE UPPER GREAT LAKES REGION AND CAUSE A WARM FRONT TO CROSS OUR AREA FRIDAY. A COLD FRONT WILL FOLLOW FOR FRIDAY NIGHT. MORE HIGH PRESSURE WILL BUILD IN FOR THE WEEKEND AND REMAIN INTO MONDAY. ANOTHER LOW AND SERIES OF FRONTS WILL AFFECT THE WEATHER NEXT TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... NOT TOO MANY CHANGES WITH THIS UPDATE. WE ADDED SOME PATCHY MORNING DRIZZLE MAINLY IN NJ BASED ON OBS AND RADAR RETURNS. WE USED LATEST HRRR AND RAP TRENDS TO LOWER POPS THROUGH THE MID DAY FOR THE REMNANT PCPN SOUTH AND OTHER PCPN TRYING TO ARRIVE FROM THE WEST. AGREE WITH MID SHIFT TEMPS ARE GOING NOWHERE TODAY. A FRONTAL BOUNDARY WAS LOCATED FROM THE WESTERN SIDE OF THE CENTRAL APPALACHIANS BACK DOWN INTO THE CAROLINAS EARLY THIS MORNING. MEANWHILE, HIGH PRESSURE LOCATED OVER EASTERN CANADA CONTINUES TO RIDGE SOUTHWARD INTO THE NORTHEAST AND MID-ATLANTIC STATES. WITH THIS CAD PATTERN ON THE EASTERN SIDE OF THE APPALACHIANS HOLDING STRONG, EXPECT TODAY TO BE PRETTY MUCH A REPEAT OF YESTERDAY: CLOUDY AND COOL BUT SLIGHTLY LESS WET AND WINDY. THE ONE CONCERN EARLY THIS MORNING IS SPOTTY FREEZING DRIZZLE AND FREEZING FOG AT HIGHER ELEVATIONS IN THE POCONOS. BASED ON LATEST MESONET OBSERVATIONS, TEMPS ARE MARGINALLY FREEZING (31-32F) ABOVE 1500 FT. ISSUED AN SPS FOR THESE AREAS TO COVER THE POSSIBILITY OF LIGHT ICING ON ELEVATED SURFACES. EXPECT LITTLE IMPACTS THOUGH WITH PAVEMENT TEMPERATURES REMAINING ABOVE FREEZING. REMNANTS FROM A DECAYING MCS THAT IS CURRENTLY OVER VA WILL MOVE EASTWARD EARLY THIS MORNING. THIS WILL BRING A PERIOD OF SHOWERS TO THE DELMARVA AND POSSIBLY AS FAR SOUTHERN NJ BETWEEN 4-9 AM. OTHERWISE, COVERAGE OF RAIN EXPECTED TO BE MINIMAL FOR THE REST OF THE DAY WITH ORGANIZED LIFT AND INSTABILITY STILL WELL TO OUR WEST. BASED ON VERIFICATION OF TEMPS YESTERDAY AND LAST NIGHT, FELT IT WAS PRUDENT TO GO COLDER THAN STAT GUIDANCE FOR TEMPS TODAY. WE FAVORED THE RAW OUTPUT FROM THE NCEP WRF ARW/NMM, WHICH GIVES US HIGHS IN THE 40S (15-20F BELOW NORMAL). && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/... SOUTHWESTERLY FLOW WILL STRENGTHEN ALOFT AS LOW PRESSURE DEEPENS OVER THE GREAT LAKES. THIS WILL ADVECT WARMER AIR ALOFT INTO THE REGION BUT THE SHALLOW LAYER OF COLD AIR TRAPPED IN THE LOWEST 1000 FT OF THE ATMOSPHERE WILL PREVENT THE WARM FRONT FROM MAKING IT INTO OUR AREA. THEREFORE, CLOUDY, COOL AND DAMP CONDITIONS WILL PERSIST INTO TONIGHT. FORECAST SOUNDINGS APPEAR A BIT MORE FAVORABLE FOR DRIZZLE TONIGHT THAT IT DID LAST NIGHT WITH ISENTROPIC LIFT AND MOISTURE ADVECTION ABOVE THE CAD WEDGE. WE WILL NEED TO KEEP AN EYE OUT ON POTENTIAL MCS DEVELOPMENT UPSTREAM THIS AFTERNOON OVER THE MIDWEST. THE REMNANTS OF THIS SYSTEM COULD BRING A ROUND OR TWO OF SHOWERS TO OUR REGION TONIGHT. THE WARM NOSE AROUND 900 MB STRENGTHENS LATE AND THE 00Z NAM BUFKIT SOUNDINGS FORECASTS SEVERAL HUNDRED J/KG OF ELEVATED INSTABILITY TO DEVELOP OVER OUR AREA TOWARD EARLY MORNING. OPTED TO NOT PUT IN ANY MENTION OF THUNDER AS THERE IS A LITTLE BIT OF CIN FOR PARCELS TO OVERCOME, WHICH MAY INHIBIT CONVECTION GIVEN A LACK OF SIGNIFICANT LIFT. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... FRIDAY/FRI NIGHT...THE RECENT ONSHORE FLOW OF COLD AND MOIST AIR WILL DIMINISH AS A COLD FRONT APPROACHES FROM THE WEST. IF THE LOW CLOUDS DIMINISH FAST ENOUGH...IT COULD END UP BECOMING VERY WARM AND HUMID. SHOWERS/TSTMS ARE EXPECTED LATE AFTERNOON AND EARLY EARLY OVERNIGHT AS A COLD FRONT APPROACHES. THE SRN HALF OF OUR CWA IS IN A SLIGHT RISK FOR SVR WEATHER FRIDAY. SAT THRU MONDAY...MOSTLY FAIR WITH SEASONABLE TEMPERATURES. HIGH PRESSURE BUILDS IN SAT...CRESTS OVER THE AREA SUN AND THEN MOVES EAST MONDAY. HIGH TEMPS MOSTLY IN THE 60S SAT/SUN AND CLOSER TO 70 MON. TUE THRU WED...ANOTHER LOW PRESSURE SYSTEM FROM THE PLAINS HEADS TOWARD THE UPPER GREAT LAKES. ITS ASSOCIATED FRONTS APPROACH THE AREA. WE WENT ALONG WITH THE WPC POPS FOR THESE PERIODS WITH MOSTLY CHC POPS. TEMPERATURES WILL BE A LITTLE ABOVE NORMAL FOR MID APRIL. && .AVIATION /13Z THURSDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. THE REGION REMAINS SOCKED IN LOW CLOUDS AND BR EARLY THIS MORNING. FLIGHT RESTRICTIONS MOSTLY FROM CIGS THAT ARE IN IFR RANGE. SIMILAR TO YESTERDAY, EXPECT SOME IMPROVEMENT TO MVFR DURING THE DAY WITH CIGS BETWEEN 1 AND 2 KFT AGL. THIS GRADUAL IMPROVEMENT WILL LIKELY OCCUR AT THE TERMINALS FROM NE TO SW BETWEEN 14Z AND 18Z. ONSHORE FLOW WILL LIKELY KEEP ACY AND POSSIBLY MIV IN IFR ALL DAY. CIGS LOWER AGAIN TONIGHT, BECOMING IFR LATE THIS EVE AND POSSIBLY LIFR OVERNIGHT. PERIODS OF RA, DZ AND FOG WILL LIKELY CAUSE VSBY RESTRICTIONS. THERE IS STILL SOME UNCERTAINTY WITH THE TIMING OF THE EXPECTED CIG IMPROVEMENT TODAY AND DETERIORATION TONIGHT SO FUTURE TAF UPDATES WILL PROVIDE REFINEMENT. NORTHEAST WINDS AROUND 10 KT THIS MORNING WILL VEER OUT OF THE EAST MIDDAY AND EVENTUALLY SOUTHEAST BY LATE TONIGHT. OUTLOOK... FRIDAY/FRIDAY NIGHT...A TRANSITIONAL DAY WITH THE LOW CLOUDS DEPARTING AND THEN SCT SHOWERS AND TSTMS DEVELOPING. MVFR/IFR WITH THE LOW CLOUDS EARLY AND THEN AGAIN LATE IN ANY TSTM. SAT THRU MONDAY NIGHT...MOSTLY VFR. && .MARINE... SCA IN EFFECT FOR OUR ATLANTIC COASTAL WATERS TODAY AND TONIGHT. THERE ARE STILL A FEW GUSTS IN THE 25 KT RANGE ALONG THE NJ COAST EARLY THIS MORNING BUT OVERALL ONSHORE WINDS SHOULD GRADUALLY WEAKEN DURING THE DAY TODAY. THE MORE WIDESPREAD HAZARD ON THE WATERS WILL BE THE SEAS WITH WAVES BETWEEN 5 AND 8 FT THRU TONIGHT. OUTLOOK... FRI/FRI NIGHT...SCA CONDITIONS WITH SCT SHOWERS AND TSTMS. SAT...SCA CONDITIONS EARLY THEN SUB-SCA WINDS/SEAS. SAT NIGHT THRU SUN NIGHT...SUB-SCA CONDITIONS EXPECTED. MONDAY...SCA CONDITIONS POSSIBLE. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ450>455. && $$ SYNOPSIS...O`HARA NEAR TERM...GIGI/KLEIN SHORT TERM...KLEIN LONG TERM...O`HARA AVIATION...KLEIN/O`HARA MARINE...KLEIN/O`HARA
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
922 AM EDT THU APR 9 2015 .DISCUSSION...LTST WV IMAGERY ALONG WITH SOUNDING DATA FROM XMR CONFIRM AN UNFAVORABLE ENVIRONMENT EXISTS FOR DEVELOPMENT OF PCPN TODAY. E-SE WINDS FROM THE SFC THROUGH 10KFT...COUPLED WITH E- NE/INCREASINGLY ANTICYCLONIC MID LEVEL FLOW...WILL CONTINUE TO DRAW IN LOWER PWAT AIR. LTST HRRR GUID SHOWS A FEW ECHOES LIKELY ASCD WITH INLAND PROGRESSION OF MARINE CU LINES AND THE POSSIBILITY OF SOME LOW TOPPED SPRINKLES MOVING ASHORE MAINLY FROM THE TREASURE CST SWD. NO MEASURABLE RAINFALL IS ANTICIPATED FROM THIS ACTIVITY. THE CURRENT FORECAST IS IN GOOD SHAPE. && .AVIATION...VFR CONDS. SOME SCT BASES NR FL 040 REMAIN PSBL IN CU LINES ALONG THE CST AND SOMEWHAT INLAND THROUGH THE AFTN. && .MARINE...(PREVIOUS DISC) HIGH PRESSURE REMAINS IN FIRM CONTROL OF LCL WX. ESE-SE WINDS 10-15KT WITH SEAS 3FT NEAR SHORE AND 4FT AWAY FROM THE COAST. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ JP/FJ
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1003 PM CDT THU APR 9 2015 .SHORT TERM... 238 PM CDT THROUGH SATURDAY... VISIBLE IMAGERY EARLY THIS AFTERNOON INDICATED MOSTLY CLEAR SKIES OVER NORTHERN IL/NORTHWEST IN...HOWEVER WITH A ROBUST MID-LVL VORT MAX PIVOTING SOUTHEAST ACROSS THE UPPER MIDWEST TOWARDS CENTRAL WISC...COUPLED WITH STEEPENING LAPSE RATES...CUMULUS CLOUDS ARE BEGINNING TO DEVELOP. REGIONAL RADAR MOSAIC INDICATED RAIN SHOWERS OVER CENTRAL/WESTERN WISC...AND SLIDING SOUTHEAST. REFLECTIVITY HAS INCREASED AND ITS POSSIBLE SOME ISOLATED LIGHTNING WITH PEA SIZE HAIL...EXPECT THIS TO BE CONFINED TO NORTH OF A ROCKFORD TO WAUKEGAN LINE THROUGH EARLY THIS EVENING. PRESSURE GRADIENT REMAINS TIGHT WITH GOOD MIXING AHEAD OF THE SHORTWAVE...ALLOWING GUSTS TO FREQUENTLY BE TOUCHING 35 MPH. IT IS POSSIBLE A FEW GUSTS COULD TOUCH 45 MPH BEFORE SUNSET. WILL GO WITH A WIND ADVISORY THROUGH SUNSET FOR THE ENTIRE CWFA. TROUGH AXIS WILL STEADLY PIVOT EAST THIS EVENING...ALLOWING SFC RIDGE OVER THE CENTRAL PLAINS TO SLIDE EAST OVERNIGHT AND BRING WINDS DOWN. IN ADDITION THE DIURNAL CLOUDS WILL QUICKLY ERODE...ALLOWING SKIES TO BECOME MOSTLY CLEAR BY EARLY SAT MORNING. TEMPS OVERNIGHT WILL FALL INTO THE MID/UPR 30S. ANTI-CYCLONIC FLOW WILL REMAIN OVERHEAD SAT...ALLOWING MOSTLY SUNNY SKIES TO RULE MUCH OF SAT. WINDS WILL START OUT LIGHT AND VARIABLE...BUT WITH HIGH PRESSURE SLIDING EAST BY SAT AFTN/EVE...WINDS SHOULD START TO TURN WEST/SOUTHWEST. WITH THE LIGHT GRADIENT AND LAND WARMING UP...A LAKE BREEZE WILL BE ABLE TO DEVELOP. THE CHALLENGE WILL BE HOW FAR INLAND BEFORE WINDS SHIFT WEST/SOUTHWEST...WHICH COULD LIMIT THE INLAND PUSH OF A LAKE BREEZZE. TEMPS SAT WILL PUSH INTO THE LOW 60S...LIKELY HOLDING IN THE LOW/MID 50S CLOSER TO LAKE MICHIGAN. IF THE LAKE BREEZE CAN PUSH INLAND...TEMPS ALONG THE SHORELINE MAY DIP INTO THE MID 40S. BEACHLER && .LONG TERM... 238 PM CDT SUNDAY THROUGH FRIDAY... SFC RIDGING SHOULD LINGER SAT NGT/EARLY SUN...HOLDING THE DRY CONDS UNTIL JUST AFT DAYBREAK SUN. 500MB TROUGH ACROSS THE EASTERN PACIFIC WILL PUSH EAST TOWARDS THE ROCKIES...WHICH WILL ALLOW FLOW IN THE MID-LVLS TO TURN SOUTHWESTERLY. WITH THE SFC RIDGE BECOMING CENTERED ACROSS THE MID- ATLANTIC REGION SUN...LLVL MOISTURE ALONG THE WESTERN PERIPHERY OF THE RIDGE WILL INCREASE AND STREAM NORTH FROM THE WESTERN GULF EARLY SUN. IT IS POSSIBLE PRECIP MAY HOLD OFF UNTIL MID/LATE SUN MORNING...HOWEVER FEEL THAT WITH THE PROGRESSIVE FLOW IN THE MID- LVLS PRECID SHUD EASILY REACH THE FORECAST AREA SUN. A TROUGH AXIS WILL BE PIVOTING EAST ACROSS THE WESTERN GREAT LAKES...WHICH WILL AID IN BRINGING A SOME INSTABILITY/FORCING BACK TO THE REGION SUN. THE FRONTAL BOUNDARY WILL BE STEADILY PIVOTING EAST SUN NGT/MON...WITH YET ANOTHER SFC RIDGE PUSHING EAST AND ARRIVING OVER THE FORECAST AREA BY TUE AND BRINGING DRY AIR TO THE CWFA. THEN LATER IN THE WEEK ANOTHER TROUGH DIGS INTO THE CENTRAL PLAINS...WITH THE NEXT CHC FOR PRECIP ARRIVING LATE NEXT WEEK. TEMPS THROUGH THE FORECAST PERIOD WILL MAINLY BE IN THE 60S. BEACHLER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 03Z... * NONE. KJB //DISCUSSION...UPDATED 00Z... ANOTHER COLD FRONT IS CURRENTLY SHIFTING OVER THE EASTERN TERMINALS AND THIS IS RESULTING IN MORE OF A NORTHWESTERLY WIND...WITH A COUPLE OF SCATTERED SHOWERS. THESE STRONG WINDS ARE STILL EXPECTED TO QUICKLY ABATE THIS EVENING WITH SUNSET. SURFACE HIGH PRESSURE WILL TRACK EASTWARDS ACROSS CENTRAL ILLINOIS AND INTO THE OHIO VALLEY DURING THE DAY SATURDAY. THIS WILL RESULT IN A LIGHTER WEST TO SOUTHWESTERLY WIND DURING THE DAY. OVERALL...VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. KJB //ORD AND MDW CONFIDENCE...UPDATED 03Z... * HIGH FOR ALL ELEMENTS. KJB //OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z... SUNDAY...CHC SHRA IN THE AFTN...TSRA LIKELY OVERNIGHT. GUSTY SOUTH WINDS BCMG WEST OVERNIGHT. MONDAY...SCHC -SHRA EARLY. WEST WINDS BCMG NW. TUESDAY...VFR. NORTH WINDS BCMG SOUTHEAST. WEDNESDAY...VFR. CHANCE OF THUNDERSTORMS WED NIGHT. SOUTHEAST WINDS BCMG SOUTH. THURSDAY...CHC TSRA. SOUTH WINDS BCMG SOUTHWEST. KJB && .MARINE... 238 PM CDT STRONG AND GUSTY WEST GALES WILL CONTINUE FOR PORTIONS OF THE NEARSHORE...HOWEVER WITH THE STABILITY IN PLACE EXPECT THE FIRST MILE OR TWO OF THE NEARSHORE TO MAINLY SEE THE GALES THROUGH SUNSET. HIGH PRESSURE WILL PUSH IN TONIGHT...AND ALLOW WINDS TO STEADILY DIMINISH TONIGHT. WITH THE WEST TO NORTHWEST WINDS...HAZARDOUS WAVES WILL LIKELY PERSIST FOR THE INDIANA SHORELINE. FLOW WILL THEN TURN SOUTHWEST SUNDAY...BEFORE THE NEXT APPROACHING COLD FRONT MOVES ACROSS THE LAKE AND TURNS THINGS NORTHWEST AGAIN. THIS WEST TO NORTHWEST TO SOUTH PATTERN REPEATS ITSELF MONDAY THROUGH WEDNESDAY BEFORE THE NEXT COLD FRONT APPROACHES ON THURSDAY. OVERALL MOSTLY QUIET WEATHER IS EXPECTED THROUGH THE PERIOD...THOUGH THE FRONT ON SUNDAY NIGHT COULD SUPPORT SHOWERS AND THUNDERSTORMS. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WIND ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011- ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023- ILZ032-ILZ033-ILZ039...2 PM FRIDAY TO 7 PM FRIDAY. IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...2 PM FRIDAY TO 7 PM FRIDAY. LM...GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...2 PM FRIDAY TO 7 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 854 PM CDT Thu Apr 9 2015 .UPDATE... ISSUED AT 854 PM CDT THU APR 9 2015 Vigorous shortwave and jet streak are pushing a cold front rapidly across IL. They have triggered strong to severe storms with isolated tornadoes this afternoon/evening. Remaining storms seem to be evolving into more outflow dominated storms, but will continue to monitor for any localized rotations the next couple hours. Storms and cold front are projected to be east of our IL counties by 11 pm, with strong west-southwest winds in their wake. Sustained winds behind the front will increase to 20 mph and gust to 35 mph at times. A brief period of clearing skies may follow the front for an hour or so, but low clouds will return for 6-8 hours the rest of the night. Clear skies will return from west to east around sunrise tomorrow, with gusty winds continuing. Low temps will drop about 20 degrees colder than last night, with readings in the mid to upper 40s toward sunrise. Likewise, highs on Friday will be around 15-18F colder than today, but still in the low 60s. Updated the weather and PoP forecasts to match expected trends, with minor adjustments to clouds cover timing. Updated info will be available by 9 pm. && .SHORT TERM...(Tonight) ISSUED AT 307 PM CDT THU APR 9 2015 19z/2pm surface analysis shows 998mb low centered over southeast Iowa, with cold front trailing southward into western Missouri. Line of convection is rapidly developing along the front within the moderately unstable and uncapped airmass in the warm sector. 0-6km bulk shear values will be on the increase as the afternoon progresses as a mid-level short-wave approaches from the west, resulting in continued convective intensification. HRRR has had a good handle on the situation throughout the day, with its latest iteration agreeing closely with prior runs. Based on satellite timing tools and HRRR guidance, it appears the line of storms will cross the Mississippi River by 23z/6pm, then will track through the Illinois River Valley and to the I-55 corridor by about 02z/8pm. Damaging wind gusts will be the primary threat, but large hail and a few tornadoes will be possible as well. As the storms move further east, they will likely congeal into a solid line and the tornado threat will diminish accordingly. Once the front passes, windy and cooler weather will be on tap overnight with a slow west to east clearing trend by dawn. && .LONG TERM...(Friday through Thursday) ISSUED AT 307 PM CDT THU APR 9 2015 Morning upper air shows a potential severe event this afternoon and evening, as main upper level shortwave and vort max over southwest NE at 12z will be rotating to the east. Low level thermal ridge and moisture axis extends into MO/IL ahead of the approaching front. low level jet is particularly strong flowing into MO/western IL and so ample shear available in warm sector. HRRR model and NAM a little slower on the movement of the front through the region, going through this evening. Shear with strong upper jet and low level southern jet will make severe potential with severe storms possible on the cold front as it sweeps through. Deepening surface low to move northeast into eastern IA and then southern WI. High pressure in control until weak front moves in and brings showers on late Sunday and Sunday night. Another chance off showers Tuesday into Thursday. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) ISSUED AT 700 PM CDT THU APR 9 2015 Line of storms firing along a cold front will produce heavy rain, hail and possible tornadoes. Lower chances that any terminal site will get hit directly by any severe weather, but still possible. Target window should be 2 hours as the line moves through, so we continued with 2hr tempos for heavy rain and MVFR vis/cig. Upstream obs and satellite images show a break in the MVFR cigs should follow the line, before MVFR clouds return in wrap-around moisture behind the low pressure system. Will continue MVFR clouds until 10z at PIA, then advance clearing eastward into Friday morning. Strong winds will continue both ahead of the front and behind. Wind direction will remain SW ahead of the front, with gusts to 30kt, then become west later tonight. Gusts will increase to 25-30kt tomorrow as mid level jet winds continue to be strong. && .ILX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH until 1 AM CDT Friday FOR ILZ054>057-061>063- 066>068-071>073. && $$ UPDATE...Shimon SHORT TERM...Barnes LONG TERM...Goetsch AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
316 PM CDT THU APR 9 2015 .MESOSCALE DISCUSSION... 241 PM CDT THUNDERSTORM ACTIVITY CONTINUES ACROSS PORTIONS OF CENTRAL ILLINOIS THIS AFTERNOON THOUGH HAVE AT LEAST TEMPORARILY SHOWN SIGNS OF WEAKENING WITH DIMINISHED LIGHTNING ACTIVITY NOTED AND SUBTLE WARMING OF THE CLOUD TOPS. THESE STORMS HAVE MAINLY BEEN ALONG THE LEADING EDGE OF THE INSTABILITY GRADIENT WHICH IS ADVECTING NORTHEAST THIS AFTERNOON. OVER THE LAST FEW HOURS ALL OF NORTHERN ILLINOIS HAS UNDERGONE AT LEAST MODEST DESTABILIZATION WHILE THE GREATEST AMOUNT HAS OCCURRED OVER CENTRAL ILLINOIS. STORMS ARE MOVING INTO A BETTER LOW LEVEL SHEAR ENVIRONMENT AND WITH THE GIVEN DESTABILIZATION EXPECT THAT THE WEAKENING TREND WILL BE TEMPORARY. ALREADY HAVE SEEN NEW TOWERS BUILDING IN ADVANCE OF THE ORIGINAL THUNDERSTORM CLUSTER. FARTHER WEST THE COLD FRONT CONTINUES TO SHOW SIGNS OF INCREASING CONVECTION THOUGH COLD POOL IS NOT READILY EVIDENT AS OF YET. OUT AHEAD OF THE COLD FRONT...PARTIAL CLEARING HAS ALLOWED TEMPS TO WARM INTO THE MID/UPPER 70S WITH LOW/MID 60 DEWPOINTS RESULTING IN STRONG INSTABILITY ALONG WITH STRONG DCAPE. EXPECT CONVECTION TO CONTINUE TO INCREASE IN INTENSITY AND FOR COLD POOLS TO MERGE IN THE NEXT HOUR OR TWO WITH ACCELERATION OF THE LINE PER CORFIDI VECTORS OF 40-50 KTS. GIVEN THE STRONG LOW LEVEL SHEAR AND INCREASING DEEP LAYER SHEAR OUT AHEAD AND BOUNDARIES FROM THE FIRST CLUSTER OF CONVECTION...THERE REMAINS A TORNADO THREAT AS THIS LINE MOVE INTO NORTHERN ILLINOIS. DEUBELBEISS && .SHORT TERM... 400 AM CDT TODAY AND TONIGHT... DENSE FOG CONTINUES IN COOL/SATURATED AIR MASS WITH NORTHEAST WINDS OFF THE LAKE THIS MORNING...WILL MAINTAIN DENSE FOG ADVISORY ALONG THE LAKE AS ISSUED. CLUSTERS OF THUNDERSTORMS WERE OCCURRING EARLY THIS MORNING ACROSS THE MIDWEST...IN A REGION OF BROAD SOUTHWESTERLY WARM/MOIST ADVECTION ATOP NEARLY STATIONARY FRONTAL BOUNDARY WHICH STRETCHES FROM THE CENTRAL PLAINS INTO SOUTHERN IOWA...THEN EAST ACROSS CENTRAL ILLINOIS AND INDIANA. THESE CLUSTERS OF STORMS WERE GENERALLY TIED TO INDIVIDUAL MINOR-AMPLITUDE MID-LEVEL SHORT WAVE FEATURES...AND ASSOCIATED LOCALIZED ENHANCED MOISTURE TRANSPORT AND ASCENT. TO THE WEST...STRONG UPPER TROUGH WAS MOVING ONTO THE PLAINS EAST OF THE ROCKIES...AND IS PROGGED TO APPROACH THE MID- UPPER MISSISSIPPI VALLEY LATE THIS AFTERNOON AS A COMPACT AND SOMEWHAT NEGATIVELY-TILTED ENERGETIC DISTURBANCE. SURFACE LOW PRESSURE IN THE VICINITY OF SOUTHWEST KANSAS AT THIS HOUR WILL DEEPEN AND LIFT TO SOUTHWESTERN WISCONSIN/FAR NORTHWEST IL PER COMPLIMENTING GUIDANCE SOLUTIONS...WITH THE FRONT LIFTING NORTH AS A WARM FRONT ACROSS THE FORECAST AREA. THIS PATTERN HAS ALL THE EARMARKS OF BEING A WIDESPREAD SEVERE WEATHER PRODUCER ACROSS THE AREA THIS AFTERNOON AND EVENING. WITH THAT SAID...QUESTIONS REMAIN WITH RESPECT TO EVOLUTION OF STORMS LATER TODAY...MAINLY DUE TO THE EXPECTATION THAT SEVERAL CLUSTERS OF STORMS WILL CONTINUE TO DEVELOP/PROPAGATE ACROSS THE AREA THROUGH MUCH OF THE DAY DUE TO PERSISTENT WARM/MOIST ADVECTION AND ASCENT IN REGION OF STEEP MID-LEVEL LAPSE RATES AHEAD OF THE DEEPENING TROUGH AND SURFACE LOW. CONVECTION ALLOWING GUIDANCE (HRRR/NMM/ARW RUNS) DEPICT SEVERAL CLUSTERS DEVELOPING AND LIFTING ACROSS THE AREA THROUGH THE MORNING AND MIDDAY HOURS...AND REGIONAL RADAR MOSAIC SEEMS TO INDICATE THIS WILL BE THE TREND AT LEAST THROUGH THIS MORNING. THUS WHILE SYNOPTIC FEATURES WILL BE STRONG...MESOSCALE BOUNDARIES AND FORCING REMAIN UNCLEAR AT THIS TIME. STILL...STRONG FORCING IN ADVANCE OF COLD FRONT COUPLED WITH STRONG ASCENT ASSOCIATED WITH COMPACT WAVE SHOULD BE CAPABLE OF GENERATING ORGANIZED SEVERE STORMS LATER THIS AFTERNOON. 00Z NAM FORECAST SOUNDINGS INDICATE WARM SECTOR MLCAPES AROUND 1500-2000 J/KG...WITH AMPLE DEEP AND LOW LEVEL SHEAR. SPC NOTES SOME UNCERTAINTY WITH RESPECT TO STORM MODE...LINE SEGMENTS AS OPPOSED TO DISCRETE CELLS...THOUGH SUPERCELLULAR CHARACTERISTICS ARE LIKELY GIVEN THE ENVIRONMENT. DAMAGING WINDS FROM LINES/LINE SEGMENTS LOOKS TO BE THE MOST WIDESPREAD THREAT...THOUGH NORTHERN IL/SOUTHERN WI...WHERE WINDS WILL MOST LIKELY BE BACKED MORE STRONGLY AHEAD OF THE LOW...WILL STILL HAVE A REAL TORNADO POTENTIAL. STORMS WILL LIKELY EVOLVE UPSCALE INTO SQUALL-LINE AS COLD FRONT MOVES ACROSS THE AREA EARLY THIS EVENING...WITH THUNDERSTORM/SEVERE THREAT QUICKLY WINDING DOWN BEFORE MIDNIGHT AFTER FROPA. RATZER && .LONG TERM... 257 PM CDT FRIDAY THROUGH THURSDAY... FOLLOWING A PERIOD OF VERY ACTIVE WEATHER...FOLLOWING THE PASSAGE OF THE COLD FRONT LATE THURSDAY NIGHT...A PERIOD OF RELATIVE CALM WILL SET UP FOR FRIDAY INTO SUNDAY AS A COOL...DRY HIGH PRESSURE AREA BUILDS ACROSS THE AREA. TEMPERATURES WILL DROP BACK TO CLOSER TO SEASONAL HIGHS NORMAL LEVELS WITH HIGHS IN THE UPPER 50S TO AROUND 60F UNDER MOSTLY SUNNY SKIES. AS THE HIGH WILL BE RIGHT OVER THE AREA FRIDAY NIGHT INTO SATURDAY MORNING...LIGHT WINDS AND A DRY AIRMASS WILL ALLOW FOR SOME ENHANCED RADIATIVE COOLING OVERNIGHT FOR LOWS TO DROP BACK INTO THE MIDDLE TO UPPER 30S SATURDAY MORNING. WITH THE HIGH BEGINNING TO BUILD OFF TO THE EAST THROUGH SATURDAY NIGHT AND SUNDAY...A RETURN FLOW OF MOISTURE AND WARMER AIR WILL KEEP THE COOLING TREND VERY BRIEF WITH TEMPS REBOUNDING BACK TO AROUND 60F OVER MUCH OF THE CWA...WITH THE EXCEPTION OF THE IMMEDIATE LAKEFRONT...WHICH SHOULD REMAIN COOLER AS A WEAK PRESSURE GRADIENT AND DIFFERENTIAL HEATING BETWEEN THE COOL LAKE WATER AND WARMER LAKE SHOULD ALLOW A LAKE BREEZE TO DEVELOP. HIGHS ON SATURDAY ALONG THE LAKE FRONT TOPPING OUT IN THE MIDDLE 50S. INCREASING SOUTHERLY FLOW ON THE WESTERN PERIPHERY OF THE HIGH MOVING OFF TO THE EAST WILL LIKELY PREVENT A LAKE BREEZE FROM DEVELOPING. FOR SUNDAY...A NORTHERN STREAM SHORT WAVE MOVING OUT OF THE NRN ROCKIES SHOULD BEGIN TO PHASE WITH A SOUTHERN STREAM SHORTWAVE LIFTING INTO THE MIDDLE MISSISSIPPI VALLEY. THIS PHASING SHOULD RESULT IN AN AMPLIFYING LONG WAVE TROUGH OVER THE MIDDLE AND UPPER MISSISSIPPI VALLEY AND BRINGING THE NEXT CHANCE OF PCPN TO THE REGION. THE LONGER RANGE GUIDANCE...IN GENERAL...AGREE ON THE SCENARIO...BUT DIFFERENCES IN THE TIMING OF THE INDIVIDUAL SHORTWAVE AND THE DEGREE OF PHASING AND THE RESULTANT STRENGTH OF THE LONG WAVE TROUGH LEAD TO A RELATIVELY LOW CONFIDENCE FORECAST FOR THE LATTER PORTIONS OF THE EXTENDED FORECAST PERIOD. CURRENTLY FEEL THAT A COLD FRONT MOVING ACROSS THE AREA SUNDAY INTO SUNDAY NIGHT AND THEN SHUTTING OFF BY MONDAY MORNING AS ANOTHER HIGH PRESSURE SYSTEM MOVES ACROSS THE AREA. WHILE THERE IS MODERATE TO HIGH CONFIDENCE IN A PERIOD OF PCPN SUNDAY AND SUNDAY NIGHT...START AND END TIMES REMAIN UNCERTAIN AS WELL AS THE CHANCES FOR THUNDERSTORMS WITH THE PCPN AND WILL LIKELY BE HIGHLY DEPENDENT ON THE SPEED OF AN ASSOCIATED COLD FRONT MOVING THROUGH THE AREA. FOR THE LATTER PORTIONS OF THE FORECAST PERIOD...FROM TUESDAY THROUGH THURSDAY...THERE COULD BE ANOTHER PERIOD OF UNSETTLED WEATHER AS THE UPPER LEVEL FLOW PATTERN MAINTAINS A HIGH AMPLITUDE...QUICKLY PROGRESSIVE PATTERN. THE GFS/ECMWF ARE ACTUALLY SHOWING BETTER CONSISTENCY FOR THE END OF THE LONGER TERM FORECAST PERIOD THAN EARLIER...WITH ANOTHER LONG WAVE TROUGH DEVELOPING OVER THE CNTRL PLAINS. THE ECMWF IS TRENDING A BIT STRONGER AND DEVELOPING MORE OF A NEGATIVE TILT TO THE TROUGH AND A CLOSED UPPER LOW BY WEDNESDAY NIGHT...THE GFS IS REMARKABLY SIMILAR...BUT ABOUT 24 HOURS SLOWER IN DEVELOPING THE NEGATIVE TILT UPPER TROUGH AND CLOSED UPPER LOW. SHOULD THIS SCENARIO PAN OUT...THE MIDDLE OF NEXT WEAK COULD BE RIPE FOR ANOTHER PERIOD OF ACTIVE WEATHER. KREIN && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * SCATTERED STORMS EXPECTED THIS AFTN...WITH THE FINAL ROUND OF STORMS MOVING THROUGH ARND 2Z. SOME OF THESE STORMS COULD BE SEVERE. * GUSTY SSW WINDS WITH GUSTS ARND 25 KT. * IFR VSBY EXPECTED WITH TSRA. * GUSTY WINDS BCMG SW TO W ARND MIDNIGHT WITH MAX GUSTS 30-35 KT. JEE //DISCUSSION...UPDATED 18Z... STILL LOOKING AT A VERY MESSY FORECAST AS THE PIECES NECESSARY FOR WIDESPREAD STORMS ARE NOT COMPLETELY LINING UP. THE SFC LOW IS OVER IOWA WHILE ITS WARM FRONT STRETCHES FROM IOWA CITY IOWA THROUGH ORD AND ITS COLD FRONT IS OVER WESTERN MO. THE LINGERING CLOUD COVER IS INHIBITING DEVELOPMENT EARLY THIS AFTERNOON BUT THINKING STRONG LIFT FROM THE LOW PRESSURE SYSTEM WILL ALLOW STORMS TO DEVELOP. THINKING STORMS WILL GET STARTED OVER IOWA AND CENTRAL IL AND REACH THE EASTERN TERMINALS LATE THIS AFTERNOON INTO THE EARLY EVENING. FOR RFD...WILL LIKELY SEE STORMS A BIT EARLIER IN THE MID TO LATE AFTN. ONCE AGAIN SOME OF THESE STORMS MAY BE SVR WITH LARGE HAIL...DAMAGING WINDS...AND MAYBE AN ISOLATED TORNADO. THE COLD FRONT SWINGS THROUGH THIS EVENING WITH ANOTHER ROUND OF ORGANIZED STORMS EXPECTED ALONG IT. IFR VSBY AND MVFR CIGS ARE PSBL ONCE AGAIN. WINDS SHIFT TO THE SW AND W BEHIND THE FRONT WITH GUSTS UP TO 30 KT. GUSTY WEST WINDS WITH VFR CIGS AND VSBY ARE EXPECTED TOMORROW. JEE //ORD AND MDW CONFIDENCE...UPDATED 20Z... * HIGH CONFIDENCE IN SCATTERED STORMS THIS AFTN FOLLOWED BY A SEGMENT OR LINE OF STORMS THIS EVENING. MEDIUM CONFIDENCE IN COVERAGE THIS AFTERNOON AND TIMING. * MEDIUM CONFIDENCE IN WIND DIRECTION BEHIND THE SCATTERED STORMS. WINDS COULD BE CHAOTIC FOR A BRIEF PERIOD OF TIME. * HIGH CONFIDENCE IN REDUCED VSBY UNDER STORMS...MEDIUM-LOW CONFIDENCE IN CIG HEIGHTS. * MEDIUM CONFIDENCE IN WIND GUSTS OVERNIGHT AND TOMORROW...GUSTS COULD BE HIGHER. JEE //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... * FRIDAY NIGHT...SLIGHT CHANCE OF SHRA. MVFR POSSIBLE. NORTHWEST WINDS. * SATURDAY...DRY/VFR. SOUTHWEST WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...DRY/VFR. GUSTY SOUTH WINDS. * MONDAY...DRY/VFR. EAST WINDS. * TUESDAY...CHANCE OF SHRA/TSRA. MVFR POSSIBLE. SOUTH WINDS. * WEDNESDAY...CHANCE OF SHRA. SOUTH WINDS. && .MARINE... 315 PM CDT CONDITIONS OVER LAKE MICHIGAN ARE DETERIORATING RAPIDLY TODAY...FIRST WITH WAVES OF THUNDERSTORMS CROSSING THE SOUTHERN PORTIONS OF THE LAKE AS A WARM FRONT LIFTS NORTHWARD. AS OF 3PM CDT...THE FRONT HAD MOVED UP TO THE CENTER OF THE LAKE AND SHOULD CONTINUE TO LIFT NORTHWARD AS DEEPENING LOW PRESSURE OVER EASTERN IOWA CONTINUES TO DEEPEN AND TRACKS INTO SOUTHERN WISCONSIN BY EARLY THIS EVENING. BY THIS POINT...THE SOUTHERLY FLOW WILL REACH ALMOST TO THE NORTH END OF THE LAKE...BUT WITH STRONG PRESSURE FALLS AND A STRENGTHENING PRESSURE GRADIENT OVER THE LAKE AS THE SFC LOW APPROACHES...WINDS OVER THE SRN PORTIONS OF THE LAKE SHOULD INCREASE TO GALE FORCE FOR THE NEARSHORE WATERS AND THE SOUTH HALF OF THE LAKE. THUNDERSTORMS WILL ALSO CONTINUE TO BE A CONCERN INTO THE EVENING AS WELL. THE SFC LOW IS EXPECTED TO TRACK ACROSS THE CNTRL PORTIONS OF THE LAKE LATE THIS EVENING...WITH WINDS QUICKLY SHIFTING TO WLY-NWLY. A STRONG NORTHERLY GRADIENT BEHIND THE EXITING LOW...INCREASING COLD ADVECTION ASSOCIATED WITH A COOL HIGH PRESSURE SYSTEM DROPPING INTO THE NRN PLAINS AND STRONG PRESSURE RISES AS A RESULT OF THE COMBINATION OF THE EXITING LOW AND APPROACHING HIGH...SHOULD ALL COMBINE TO BRING SHORT PERIOD OF WEST TO NWLY GALES TO THE LAKE INTO FRIDAY AFTERNOON. THE APPROACHING HIGH SHOULD BEGIN TO OVERSPREAD THE WESTERN GREAT LAKES BY FRIDAY AFTERNOON...ALLOWING WINDS OVER THE LAKE TO DROP OFF RELATIVELY QUICKLY. FOR THE WEEKEND AND INTO EARLY NEXT WEEK...CONDITIONS OVER THE LAKE SHOULD BE RELATIVELY QUIET. ANOTHER COLD FRONT IS EXPECTED TO SWEEP ACROSS THE LAKE SUNDAY NIGHT OR MONDAY...BUT THIS SHOULD BE A LESS DYNAMIC SYSTEM...AND WINDS SHOULD NOT GET AS STRONG AS WITH THE SYSTEM APPROACHING THE LAKE AT THE CURRENT TIME. KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777- LMZ779...10 PM THURSDAY TO 1 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 308 PM CDT Thu Apr 9 2015 .SHORT TERM...(Tonight) ISSUED AT 307 PM CDT THU APR 9 2015 19z/2pm surface analysis shows 998mb low centered over southeast Iowa, with cold front trailing southward into western Missouri. Line of convection is rapidly developing along the front within the moderately unstable and uncapped airmass in the warm sector. 0-6km bulk shear values will be on the increase as the afternoon progresses as a mid-level short-wave approaches from the west, resulting in continued convective intensification. HRRR has had a good handle on the situation throughout the day, with its latest iteration agreeing closely with prior runs. Based on satellite timing tools and HRRR guidance, it appears the line of storms will cross the Mississippi River by 23z/6pm, then will track through the Illinois River Valley and to the I-55 corridor by about 02z/8pm. Damaging wind gusts will be the primary threat, but large hail and a few tornadoes will be possible as well. As the storms move further east, they will likely congeal into a solid line and the tornado threat will diminish accordingly. Once the front passes, windy and cooler weather will be on tap overnight with a slow west to east clearing trend by dawn. && .LONG TERM...(Friday through Thursday) ISSUED AT 307 PM CDT THU APR 9 2015 Morning upper air shows a pontential severe event this afternoon and evening, as main upper level shortwave and vort max over southwest NE at 12z will be rotating to the east. Low level thermal ridge and moisutre axis extends into MO/IL ahead of the approaching front. lowl level jet is particularly strong flowing into MO/western IL and so ample shear available in warm sector. HRR model and NAM a little slower on the movement of the front through the region, going through this evening. Shear with strong upper jet and low level southern jet will make severe potential with severe storms possible on the cold front as it sweeps through. Deepening surface low to move northeast into eastern IA and then southern WI. High pressure in control until weak front moves in and brings showers on late sunday and sunday night. Another chance off showers Tuesday into Thursday. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) ISSUED AT 1255 PM CDT THU APR 9 2015 Strong southwesterly winds will prevail this afternoon, with frequent gusts to between 25 and 35kt. Convection will initially be isolated, but will become more widespread by late afternoon into the early evening as a cold front moves in from the west. High-res models are in good agreement that a line of storms will develop along the advancing front near/west of the Mississippi River by mid to late afternoon, then push eastward into Illinois after that. Based on HRRR timing, have included a TEMPO group for thunder at KPIA between 23z and 01z, then further east to KCMI between 02z and 04z. Once storms pass, winds will veer to the west and increase and remain quite gusty through the night. In addition, MVFR ceilings currently across western Iowa into Kansas will spill eastward, with forecast soundings suggesting low clouds remaining in place until close to dawn Friday. After that, am expecting mostly clear skies with continued brisk westerly winds Friday morning. && .ILX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH until 1 AM CDT Friday FOR ILZ054>057-061>063- 066>068-071>073. && $$ SHORT TERM...Barnes LONG TERM...Goetsch AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
154 PM CDT THU APR 9 2015 .MESOSCALE DISCUSSION... 152 PM CDT A TORNADO WATCH HAS BEEN ISSUED FOR NORTHERN ILLINOIS AND NORTHWEST INDIANA. AS PREVIOUSLY MENTIONED...THERE ARE TWO AREAS OF CONCERN WHICH HAS RESULTED IN A LONGER DURATION TORNADO WATCH THAN NORMAL...IN EFFECT UNTIL 11 PM CDT THIS EVENING. THE FIRST AREA OF CONCERN IS AN MCV LIFTING INTO WEST CENTRAL ILLINOIS. THUNDERSTORMS ARE MOVING INTO THE LOT FORECAST AREA AS OF 2 PM CDT AND WILL CONTINUE TO LIFT NORTHEAST TOWARDS THE CHICAGO METRO OVER THE NEXT COUPLE HOURS. THE SECOND AREA IS ASSOCIATED WITH A SURFACE LOW OVER SOUTH CENTRAL IOWA...AND ITS ATTENDANT WARM/COLD FRONTS WHICH WILL IMPACT THE FORECAST AREA LATER THIS EVENING. DEUBELBEISS PREVIOUS DISCUSSION...125 PM CDT A FEW THUNDERSTORMS HAVE DEVELOPED JUST NORTHWEST/NORTH OF PEORIA THIS AFTERNOON AHEAD OF AN MCV LIFTING ACROSS THE MID MISSISSIPPI VALLEY. LATEST RAP SHOWS 35-40KT 0-6 KM SHEAR ACROSS THE REGION WITH MODERATELY STRONG INSTABILITY AROUND 1500 J/KG. SPECIAL 18Z SOUNDING FROM ILX SHOWS STRONG LAPSE RATES ATOP A MODERATELY CAPPED BOUNDARY LAYER...HOWEVER CAPPING WAS FAIRLY NON-EXISTENT ON THE 18Z DVN SOUNDING. NOT SURPRISING GIVEN THE DEEP LAYER SHEAR THAT RADAR IMAGERY SHOWS MODEST MIDLEVEL ROTATION WITHIN THE STORMS WHICH HAVE UNDERGONE GRADUAL INTENSIFICATION OVER THE LAST HOUR OR SO AND ALSO HAVE THREE BODY SCATTER SPIKES AT TIMES. EXPECT THESE STORMS TO CONTINUE TO LIFT NORTHEAST ALONG THE LEADING EDGE OF THE INSTABILITY GRADIENT AND WILL LIKELY PERSIST INTO THE LOT FORECAST AREA. WILL HAVE TO CLOSELY MONITOR THESE STORMS FOR AN ISOLATED SEVERE THREAT OVER THE NEXT COUPLE HOURS. FARTHER WEST...CONVECTION IS INCREASING ACROSS NORTHERN MISSOURI AND SOUTH CENTRAL IOWA ALONG THE COLD FRONT AND A TORNADO WATCH HAS BEEN ISSUED JUST TO OUR WEST. THIS LINE OF THUNDERSTORMS REMAINS A CONCERN FOR LATER THIS AFTERNOON INTO THE EVENING. DEUBELBEISS PREVIOUS DISCUSSION...1228 PM CDT CONTINUES TO BE A THREAT FOR SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING. BROAD ZONE OF WEAK ASCENT WITH WARM AIR ADVECTION CONTINUE TO SUPPORT SPORADIC DISORGANIZED THUNDERSTORM DEVELOP MIDDAY OVER NORTHERN ILLINOIS AND NORTHWEST INDIANA. WATER VAPOR IMAGERY DOES SHOW A WELL DEFINED SHORTWAVE MOVING INTO NORTHEAST MISSOURI WITH SHOWERS AND THUNDERSTORMS ALSO ASSOCIATED WITH THAT FEATURE. IT WOULD APPEAR THAT THIS SHORTWAVE AND WARM AIR ADVECTION IN ADVANCE OF IT WILL CONTINUE TO RESULT IN A PRETTY GOOD COVERAGE OF SHOWERS AND THUNDERSTORMS INTO THE AFTERNOON HOURS ACROSS THE CWA. MORNING SOUNDINGS FROM ACROSS THE REGION SHOWED A MOIST AND WEAKLY UNSTABLE AIR MASS IN PLACE WITH LITTLE/NO CAPPING INVERSION...SO IT IS LOOKING LIKE INSTABILITY WILL REMAIN FAIRLY MUTED ACROSS THE CWA TODAY AS ANY BREAKS IN CLOUDS END UP FILLING IN WITH CONVECTION. EFFECTIVE SHEAR IS SUFFICIENTLY STRONG TO SUPPORT A SEVERE THREAT AND SHEAR PROFILES WILL ONLY GROW MORE FAVORABLE WITH TIME TODAY FOR SEVERE THUNDERSTORMS AS CYCLONE INTENSIFIES. IT IS UNCLEAR WHAT ROLE THE MISSOURI LEAD SHORTWAVE WILL PLAY ON THE CONVECTIVE EVOLUTION. WHILE INSTABILITY WILL BE SOMEWHAT WEAKER THAN EARLIER ANTICIPATED THE STRENGTH OF THE APPROACHING CYCLONE AND WIND FIELDS STILL SUGGEST THERE AN APPRECIABLE SEVERE THREAT EXISTS GIVEN CONVECTIVE DEVELOPMENT. WITH SOMEWHAT LESS DEFINED FORCING IN THE WARM SECTOR...STORMS STAND A BETTER CHANCE OF BEING MORE DISCRETE WOULD RAISES THE CHANCES A BIT OF SUPERCELLS AND ATTENDANT WIND/HAIL AND POSSIBLE TORNADO THREAT...PARTICULARLY AS THE AFTERNOON WEARS ON AND SHEAR PROFILES FURTHER IMPROVE. THIS WILL PARTICULARLY BE THE CASE TOWARD 00Z AS 1KM AGL WINDS ARE PROGGED TO INCREASE TO OVER 40KT RESULTING IN A SUBSTANTIAL STRENGTHENING OF LOW LEVEL SHEAR. ASSUMING A MORE DISCRETE STORM MODE PERSISTS THROUGH THAT TIME THEN THE TORNADO THREAT WOULD BE HIGHER. IZZI && .SHORT TERM... 400 AM CDT TODAY AND TONIGHT... DENSE FOG CONTINUES IN COOL/SATURATED AIR MASS WITH NORTHEAST WINDS OFF THE LAKE THIS MORNING...WILL MAINTAIN DENSE FOG ADVISORY ALONG THE LAKE AS ISSUED. CLUSTERS OF THUNDERSTORMS WERE OCCURRING EARLY THIS MORNING ACROSS THE MIDWEST...IN A REGION OF BROAD SOUTHWESTERLY WARM/MOIST ADVECTION ATOP NEARLY STATIONARY FRONTAL BOUNDARY WHICH STRETCHES FROM THE CENTRAL PLAINS INTO SOUTHERN IOWA...THEN EAST ACROSS CENTRAL ILLINOIS AND INDIANA. THESE CLUSTERS OF STORMS WERE GENERALLY TIED TO INDIVIDUAL MINOR-AMPLITUDE MID-LEVEL SHORT WAVE FEATURES...AND ASSOCIATED LOCALIZED ENHANCED MOISTURE TRANSPORT AND ASCENT. TO THE WEST...STRONG UPPER TROUGH WAS MOVING ONTO THE PLAINS EAST OF THE ROCKIES...AND IS PROGGED TO APPROACH THE MID- UPPER MISSISSIPPI VALLEY LATE THIS AFTERNOON AS A COMPACT AND SOMEWHAT NEGATIVELY-TILTED ENERGETIC DISTURBANCE. SURFACE LOW PRESSURE IN THE VICINITY OF SOUTHWEST KANSAS AT THIS HOUR WILL DEEPEN AND LIFT TO SOUTHWESTERN WISCONSIN/FAR NORTHWEST IL PER COMPLIMENTING GUIDANCE SOLUTIONS...WITH THE FRONT LIFTING NORTH AS A WARM FRONT ACROSS THE FORECAST AREA. THIS PATTERN HAS ALL THE EARMARKS OF BEING A WIDESPREAD SEVERE WEATHER PRODUCER ACROSS THE AREA THIS AFTERNOON AND EVENING. WITH THAT SAID...QUESTIONS REMAIN WITH RESPECT TO EVOLUTION OF STORMS LATER TODAY...MAINLY DUE TO THE EXPECTATION THAT SEVERAL CLUSTERS OF STORMS WILL CONTINUE TO DEVELOP/PROPAGATE ACROSS THE AREA THROUGH MUCH OF THE DAY DUE TO PERSISTENT WARM/MOIST ADVECTION AND ASCENT IN REGION OF STEEP MID-LEVEL LAPSE RATES AHEAD OF THE DEEPENING TROUGH AND SURFACE LOW. CONVECTION ALLOWING GUIDANCE (HRRR/NMM/ARW RUNS) DEPICT SEVERAL CLUSTERS DEVELOPING AND LIFTING ACROSS THE AREA THROUGH THE MORNING AND MIDDAY HOURS...AND REGIONAL RADAR MOSAIC SEEMS TO INDICATE THIS WILL BE THE TREND AT LEAST THROUGH THIS MORNING. THUS WHILE SYNOPTIC FEATURES WILL BE STRONG...MESOSCALE BOUNDARIES AND FORCING REMAIN UNCLEAR AT THIS TIME. STILL...STRONG FORCING IN ADVANCE OF COLD FRONT COUPLED WITH STRONG ASCENT ASSOCIATED WITH COMPACT WAVE SHOULD BE CAPABLE OF GENERATING ORGANIZED SEVERE STORMS LATER THIS AFTERNOON. 00Z NAM FORECAST SOUNDINGS INDICATE WARM SECTOR MLCAPES AROUND 1500-2000 J/KG...WITH AMPLE DEEP AND LOW LEVEL SHEAR. SPC NOTES SOME UNCERTAINTY WITH RESPECT TO STORM MODE...LINE SEGMENTS AS OPPOSED TO DISCRETE CELLS...THOUGH SUPERCELLULAR CHARACTERISTICS ARE LIKELY GIVEN THE ENVIRONMENT. DAMAGING WINDS FROM LINES/LINE SEGMENTS LOOKS TO BE THE MOST WIDESPREAD THREAT...THOUGH NORTHERN IL/SOUTHERN WI...WHERE WINDS WILL MOST LIKELY BE BACKED MORE STRONGLY AHEAD OF THE LOW...WILL STILL HAVE A REAL TORNADO POTENTIAL. STORMS WILL LIKELY EVOLVE UPSCALE INTO SQUALL-LINE AS COLD FRONT MOVES ACROSS THE AREA EARLY THIS EVENING...WITH THUNDERSTORM/SEVERE THREAT QUICKLY WINDING DOWN BEFORE MIDNIGHT AFTER FROPA. RATZER && .LONG TERM... 416 AM CDT... FRIDAY THROUGH WEDNESDAY... DRIER AND MUCH COOLER AIR SPREADS IN BEHIND THE COLD FRONT TONIGHT... AS UPPER TROUGH LIFTS NORTHEAST ACROSS THE NORTHERN LAKES OVERNIGHT. A SECOND FAIRLY STRONG NORTHERN STREAM SHORT WAVE DROPS INTO THE BACK SIDE OF THE TROUGH FRIDAY...AND ROTATES SOUTHEASTWARD ACROSS SOUTHERN WI/NORTHERN IL AND LAKE MICHIGAN THROUGH FRIDAY EVENING. FORECAST SOUNDINGS INDICATE STEEP LOW LEVEL LAPSE RATES DEVELOPING BENEATH COOL MID LEVEL AIR ASSOCIATED WITH THE TROUGH... WHICH DESPITE RELATIVELY DRY LOW LEVEL AIR MAY BE ABLE TO PRODUCE A FEW SPRINKLES OR LIGHT SHOWERS NEAR THE IL/WI BORDER DURING THE AFTERNOON AND EARLY EVENING HOURS BEFORE DIURNAL STABILIZATION OCCURS. TEMPS RANGING FROM THE UPPER 50S NORTH TO LOWER 60S SOUTH MAY EVEN FALL A BIT IN THE AFTERNOON WITH THE PASSAGE OF A SECONDARY SURFACE TROUGH/COLD FRONT. HIGH PRESSURE THEN BUILDS IN LATER FRIDAY NIGHT AND SATURDAY...WITH DRY WEATHER AND TEMPS CLOSE TO NORMAL. LONGER RANGE GUIDANCE IN BETTER AGREEMENT IN MOVING HIGH OFF TO THE EAST ON SUNDAY AND DEVELOPING SOUTH-SOUTHEAST LOW LEVEL FLOW AHEAD OF AN APPROACHING COLD FRONT. THIS PRESENTS THE NEXT CHANCE OF PRECIP...MAINLY SUNDAY NIGHT BEFORE THE FRONT MOVES OFF TO THE EAST ON MONDAY AND HIGH PRESSURE SPREADS BACK IN. MODELS BECOME MORE DIVERGENT TUESDAY-WEDNESDAY WITH TIMING OF AN UPPER LOW LIFTING NORTHEAST ACROSS THE REGION. PRECIP CHANCES GENERALLY LOOK TO INCREASE BY MID-WEEK AS THIS SYSTEM APPROACHES...THOUGH GENERAL MODEL TREND HAS BEEN TO SLOW THINGS DOWN. IT DOES LOOK LIKE WE WARM UP NICELY IN ADVANCE OF THIS SYSTEM...WITH 70S IN THE FORECAST FOR TUE-WED. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * SCATTERED STORMS EXPECTED LATE THIS AFTN AROUND 23Z...WITH THE FINAL ROUND OF STORMS MOVING THROUGH ARND 2Z. SOME OF THESE STORMS COULD BE SEVERE. * GUSTY SSW WINDS WITH GUSTS ARND 25 KT. * IFR CIGS AND VSBY PSBL WITH TSRA. * GUSTY WINDS BCMG SW TO W ARND MIDNIGHT WITH MAX GUSTS 30-35 KT. JEE //DISCUSSION...UPDATED 18Z... STILL LOOKING AT A VERY MESSY FORECAST AS THE PIECES NECESSARY FOR WIDESPREAD STORMS ARE NOT COMPLETELY LINING UP. THE SFC LOW IS OVER IOWA WHILE ITS WARM FRONT STRETCHES FROM IOWA CITY IOWA THROUGH ORD AND ITS COLD FRONT IS OVER WESTERN MO. THE LINGERING CLOUD COVER IS INHIBITING DEVELOPMENT EARLY THIS AFTERNOON BUT THINKING STRONG LIFT FROM THE LOW PRESSURE SYSTEM WILL ALLOW STORMS TO DEVELOP. THINKING STORMS WILL GET STARTED OVER IOWA AND CENTRAL IL AND REACH THE EASTERN TERMINALS LATE THIS AFTERNOON INTO THE EARLY EVENING. FOR RFD...WILL LIKELY SEE STORMS A BIT EARLIER IN THE MID TO LATE AFTN. ONCE AGAIN SOME OF THESE STORMS MAY BE SVR WITH LARGE HAIL...DAMAGING WINDS...AND MAYBE AN ISOLATED TORNADO. THE COLD FRONT SWINGS THROUGH THIS EVENING WITH ANOTHER ROUND OF ORGANIZED STORMS EXPECTED ALONG IT. IFR VSBY AND MVFR CIGS ARE PSBL ONCE AGAIN. WINDS SHIFT TO THE SW AND W BEHIND THE FRONT WITH GUSTS UP TO 30 KT. GUSTY WEST WINDS WITH VFR CIGS AND VSBY ARE EXPECTED TOMORROW. JEE //ORD AND MDW CONFIDENCE...UPDATED 18Z... * HIGH CONFIDENCE IN SCATTERED STORMS THIS AFTN FOLLOWED BY A SEGMENT OR LINE OF STORMS THIS EVENING. MEDIUM CONFIDENCE IN COVERAGE THIS AFTERNOON AND TIMING. * MEDIUM CONFIDENCE IN WIND DIRECTION BEHIND THE SCATTERED STORMS. WINDS COULD BE CHAOTIC FOR A BRIEF PERIOD OF TIME. * HIGH CONFIDENCE IN REDUCED VSBY UNDER STORMS...MEDIUM-LOW CONFIDENCE IN CIG HEIGHTS. JEE //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... * FRIDAY NIGHT...SLIGHT CHANCE OF SHRA. MVFR POSSIBLE. NORTHWEST WINDS. * SATURDAY...DRY/VFR. SOUTHWEST WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...DRY/VFR. GUSTY SOUTH WINDS. * MONDAY...DRY/VFR. EAST WINDS. * TUESDAY...CHANCE OF SHRA/TSRA. MVFR POSSIBLE. SOUTH WINDS. * WEDNESDAY...CHANCE OF SHRA. SOUTH WINDS. && .MARINE... 416 AM...LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST TO NORTHERN LAKE MICHIGAN BY FRIDAY MORNING AS IT DEEPENS. A WARM FRONT WILL LIFT NORTH ACROSS THE CENTRAL PORTION OF THE LAKE AHEAD OF THIS LOW. EASTERLY WINDS WILL TURN SOUTHEAST THEN SOUTHERLY ACROSS THE SOUTHERN PART OF THE LAKE TODAY WITH SPEEDS STEADILY INCREASING. WITH THE LOW DEEPENING AS IT PASSES WEST OF THE LAKE...WIND SPEEDS ARE NOW EXPECTED TO REACH GALE FORCE THIS EVENING AND CONTINUE INTO FRIDAY FROM THE WEST. HOISTED A GALE WATCH THIS MORNING BUT IF TRENDS CONTINUE EXPECT A GALE WARNING TO BE NEEDED LATER TODAY. POSSIBLE GALES MAY EXTEND A BIT FURTHER NORTH THEN CURRENT WATCH...BUT WILL BE DEPENDENT ON THE TRACK OF THE LOW. WINDS DIMINISH SOME FRIDAY AND THEN DIMINISH TO 10-15KT FRIDAY NIGHT INTO SATURDAY AS THE GRADIENT RELAXES WITH HIGH PRESSURE MOVING ACROSS THE SOUTHERN LAKES AND OHIO VALLEY. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...DENSE FOG ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 3 PM THURSDAY. GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777- LMZ779...10 PM THURSDAY TO 1 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
125 PM CDT THU APR 9 2015 .MESOSCALE DISCUSSION... 125 PM CDT A FEW THUNDERSTORMS HAVE DEVELOPED JUST NORTHWEST/NORTH OF PEORIA THIS AFTERNOON AHEAD OF AN MCV LIFTING ACROSS THE MID MISSISSIPPI VALLEY. LATEST RAP SHOWS 35-40KT 0-6 KM SHEAR ACROSS THE REGION WITH MODERATELY STRONG INSTABILITY AROUND 1500 J/KG. SPECIAL 18Z SOUNDING FROM ILX SHOWS STRONG LAPSE RATES ATOP A MODERATELY CAPPED BOUNDARY LAYER...HOWEVER CAPPING WAS FAIRLY NON-EXISTENT ON THE 18Z DVN SOUNDING. NOT SURPRISING GIVEN THE DEEP LAYER SHEAR THAT RADAR IMAGERY SHOWS MODEST MIDLEVEL ROTATION WITHIN THE STORMS WHICH HAVE UNDERGONE GRADUAL INTENSIFICATION OVER THE LAST HOUR OR SO AND ALSO HAVE THREE BODY SCATTER SPIKES AT TIMES. EXPECT THESE STORMS TO CONTINUE TO LIFT NORTHEAST ALONG THE LEADING EDGE OF THE INSTABILITY GRADIENT AND WILL LIKELY PERSIST INTO THE LOT FORECAST AREA. WILL HAVE TO CLOSELY MONITOR THESE STORMS FOR AN ISOLATED SEVERE THREAT OVER THE NEXT COUPLE HOURS. FARTHER WEST...CONVECTION IS INCREASING ACROSS NORTHERN MISSOURI AND SOUTH CENTRAL IOWA ALONG THE COLD FRONT AND A TORNADO WATCH HAS BEEN ISSUED JUST TO OUR WEST. THIS LINE OF THUNDERSTORMS REMAINS A CONCERN FOR LATER THIS AFTERNOON INTO THE EVENING. PREVIOUS DISCUSSION... 1228 PM CDT CONTINUES TO BE A THREAT FOR SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING. BROAD ZONE OF WEAK ASCENT WITH WARM AIR ADVECTION CONTINUE TO SUPPORT SPORADIC DISORGANIZED THUNDERSTORM DEVELOP MIDDAY OVER NORTHERN ILLINOIS AND NORTHWEST INDIANA. WATER VAPOR IMAGERY DOES SHOW A WELL DEFINED SHORTWAVE MOVING INTO NORTHEAST MISSOURI WITH SHOWERS AND THUNDERSTORMS ALSO ASSOCIATED WITH THAT FEATURE. IT WOULD APPEAR THAT THIS SHORTWAVE AND WARM AIR ADVECTION IN ADVANCE OF IT WILL CONTINUE TO RESULT IN A PRETTY GOOD COVERAGE OF SHOWERS AND THUNDERSTORMS INTO THE AFTERNOON HOURS ACROSS THE CWA. MORNING SOUNDINGS FROM ACROSS THE REGION SHOWED A MOIST AND WEAKLY UNSTABLE AIR MASS IN PLACE WITH LITTLE/NO CAPPING INVERSION...SO IT IS LOOKING LIKE INSTABILITY WILL REMAIN FAIRLY MUTED ACROSS THE CWA TODAY AS ANY BREAKS IN CLOUDS END UP FILLING IN WITH CONVECTION. EFFECTIVE SHEAR IS SUFFICIENTLY STRONG TO SUPPORT A SEVERE THREAT AND SHEAR PROFILES WILL ONLY GROW MORE FAVORABLE WITH TIME TODAY FOR SEVERE THUNDERSTORMS AS CYCLONE INTENSIFIES. IT IS UNCLEAR WHAT ROLE THE MISSOURI LEAD SHORTWAVE WILL PLAY ON THE CONVECTIVE EVOLUTION. WHILE INSTABILITY WILL BE SOMEWHAT WEAKER THAN EARLIER ANTICIPATED THE STRENGTH OF THE APPROACHING CYCLONE AND WIND FIELDS STILL SUGGEST THERE AN APPRECIABLE SEVERE THREAT EXISTS GIVEN CONVECTIVE DEVELOPMENT. WITH SOMEWHAT LESS DEFINED FORCING IN THE WARM SECTOR...STORMS STAND A BETTER CHANCE OF BEING MORE DISCRETE WOULD RAISES THE CHANCES A BIT OF SUPERCELLS AND ATTENDANT WIND/HAIL AND POSSIBLE TORNADO THREAT...PARTICULARLY AS THE AFTERNOON WEARS ON AND SHEAR PROFILES FURTHER IMPROVE. THIS WILL PARTICULARLY BE THE CASE TOWARD 00Z AS 1KM AGL WINDS ARE PROGGED TO INCREASE TO OVER 40KT RESULTING IN A SUBSTANTIAL STRENGTHENING OF LOW LEVEL SHEAR. ASSUMING A MORE DISCRETE STORM MODE PERSISTS THROUGH THAT TIME THEN THE TORNADO THREAT WOULD BE HIGHER. IZZI && .SHORT TERM... 400 AM CDT TODAY AND TONIGHT... DENSE FOG CONTINUES IN COOL/SATURATED AIR MASS WITH NORTHEAST WINDS OFF THE LAKE THIS MORNING...WILL MAINTAIN DENSE FOG ADVISORY ALONG THE LAKE AS ISSUED. CLUSTERS OF THUNDERSTORMS WERE OCCURRING EARLY THIS MORNING ACROSS THE MIDWEST...IN A REGION OF BROAD SOUTHWESTERLY WARM/MOIST ADVECTION ATOP NEARLY STATIONARY FRONTAL BOUNDARY WHICH STRETCHES FROM THE CENTRAL PLAINS INTO SOUTHERN IOWA...THEN EAST ACROSS CENTRAL ILLINOIS AND INDIANA. THESE CLUSTERS OF STORMS WERE GENERALLY TIED TO INDIVIDUAL MINOR-AMPLITUDE MID-LEVEL SHORT WAVE FEATURES...AND ASSOCIATED LOCALIZED ENHANCED MOISTURE TRANSPORT AND ASCENT. TO THE WEST...STRONG UPPER TROUGH WAS MOVING ONTO THE PLAINS EAST OF THE ROCKIES...AND IS PROGGED TO APPROACH THE MID- UPPER MISSISSIPPI VALLEY LATE THIS AFTERNOON AS A COMPACT AND SOMEWHAT NEGATIVELY-TILTED ENERGETIC DISTURBANCE. SURFACE LOW PRESSURE IN THE VICINITY OF SOUTHWEST KANSAS AT THIS HOUR WILL DEEPEN AND LIFT TO SOUTHWESTERN WISCONSIN/FAR NORTHWEST IL PER COMPLIMENTING GUIDANCE SOLUTIONS...WITH THE FRONT LIFTING NORTH AS A WARM FRONT ACROSS THE FORECAST AREA. THIS PATTERN HAS ALL THE EARMARKS OF BEING A WIDESPREAD SEVERE WEATHER PRODUCER ACROSS THE AREA THIS AFTERNOON AND EVENING. WITH THAT SAID...QUESTIONS REMAIN WITH RESPECT TO EVOLUTION OF STORMS LATER TODAY...MAINLY DUE TO THE EXPECTATION THAT SEVERAL CLUSTERS OF STORMS WILL CONTINUE TO DEVELOP/PROPAGATE ACROSS THE AREA THROUGH MUCH OF THE DAY DUE TO PERSISTENT WARM/MOIST ADVECTION AND ASCENT IN REGION OF STEEP MID-LEVEL LAPSE RATES AHEAD OF THE DEEPENING TROUGH AND SURFACE LOW. CONVECTION ALLOWING GUIDANCE (HRRR/NMM/ARW RUNS) DEPICT SEVERAL CLUSTERS DEVELOPING AND LIFTING ACROSS THE AREA THROUGH THE MORNING AND MIDDAY HOURS...AND REGIONAL RADAR MOSAIC SEEMS TO INDICATE THIS WILL BE THE TREND AT LEAST THROUGH THIS MORNING. THUS WHILE SYNOPTIC FEATURES WILL BE STRONG...MESOSCALE BOUNDARIES AND FORCING REMAIN UNCLEAR AT THIS TIME. STILL...STRONG FORCING IN ADVANCE OF COLD FRONT COUPLED WITH STRONG ASCENT ASSOCIATED WITH COMPACT WAVE SHOULD BE CAPABLE OF GENERATING ORGANIZED SEVERE STORMS LATER THIS AFTERNOON. 00Z NAM FORECAST SOUNDINGS INDICATE WARM SECTOR MLCAPES AROUND 1500-2000 J/KG...WITH AMPLE DEEP AND LOW LEVEL SHEAR. SPC NOTES SOME UNCERTAINTY WITH RESPECT TO STORM MODE...LINE SEGMENTS AS OPPOSED TO DISCRETE CELLS...THOUGH SUPERCELLULAR CHARACTERISTICS ARE LIKELY GIVEN THE ENVIRONMENT. DAMAGING WINDS FROM LINES/LINE SEGMENTS LOOKS TO BE THE MOST WIDESPREAD THREAT...THOUGH NORTHERN IL/SOUTHERN WI...WHERE WINDS WILL MOST LIKELY BE BACKED MORE STRONGLY AHEAD OF THE LOW...WILL STILL HAVE A REAL TORNADO POTENTIAL. STORMS WILL LIKELY EVOLVE UPSCALE INTO SQUALL-LINE AS COLD FRONT MOVES ACROSS THE AREA EARLY THIS EVENING...WITH THUNDERSTORM/SEVERE THREAT QUICKLY WINDING DOWN BEFORE MIDNIGHT AFTER FROPA. RATZER && .LONG TERM... 416 AM CDT... FRIDAY THROUGH WEDNESDAY... DRIER AND MUCH COOLER AIR SPREADS IN BEHIND THE COLD FRONT TONIGHT... AS UPPER TROUGH LIFTS NORTHEAST ACROSS THE NORTHERN LAKES OVERNIGHT. A SECOND FAIRLY STRONG NORTHERN STREAM SHORT WAVE DROPS INTO THE BACK SIDE OF THE TROUGH FRIDAY...AND ROTATES SOUTHEASTWARD ACROSS SOUTHERN WI/NORTHERN IL AND LAKE MICHIGAN THROUGH FRIDAY EVENING. FORECAST SOUNDINGS INDICATE STEEP LOW LEVEL LAPSE RATES DEVELOPING BENEATH COOL MID LEVEL AIR ASSOCIATED WITH THE TROUGH... WHICH DESPITE RELATIVELY DRY LOW LEVEL AIR MAY BE ABLE TO PRODUCE A FEW SPRINKLES OR LIGHT SHOWERS NEAR THE IL/WI BORDER DURING THE AFTERNOON AND EARLY EVENING HOURS BEFORE DIURNAL STABILIZATION OCCURS. TEMPS RANGING FROM THE UPPER 50S NORTH TO LOWER 60S SOUTH MAY EVEN FALL A BIT IN THE AFTERNOON WITH THE PASSAGE OF A SECONDARY SURFACE TROUGH/COLD FRONT. HIGH PRESSURE THEN BUILDS IN LATER FRIDAY NIGHT AND SATURDAY...WITH DRY WEATHER AND TEMPS CLOSE TO NORMAL. LONGER RANGE GUIDANCE IN BETTER AGREEMENT IN MOVING HIGH OFF TO THE EAST ON SUNDAY AND DEVELOPING SOUTH-SOUTHEAST LOW LEVEL FLOW AHEAD OF AN APPROACHING COLD FRONT. THIS PRESENTS THE NEXT CHANCE OF PRECIP...MAINLY SUNDAY NIGHT BEFORE THE FRONT MOVES OFF TO THE EAST ON MONDAY AND HIGH PRESSURE SPREADS BACK IN. MODELS BECOME MORE DIVERGENT TUESDAY-WEDNESDAY WITH TIMING OF AN UPPER LOW LIFTING NORTHEAST ACROSS THE REGION. PRECIP CHANCES GENERALLY LOOK TO INCREASE BY MID-WEEK AS THIS SYSTEM APPROACHES...THOUGH GENERAL MODEL TREND HAS BEEN TO SLOW THINGS DOWN. IT DOES LOOK LIKE WE WARM UP NICELY IN ADVANCE OF THIS SYSTEM...WITH 70S IN THE FORECAST FOR TUE-WED. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * SCATTERED STORMS EXPECTED LATE THIS AFTN AROUND 23Z...WITH THE FINAL ROUND OF STORMS MOVING THROUGH ARND 2Z. SOME OF THESE STORMS COULD BE SEVERE. * GUSTY SSW WINDS WITH GUSTS ARND 25 KT. * IFR CIGS AND VSBY PSBL WITH TSRA. * GUSTY WINDS BCMG SW TO W ARND MIDNIGHT WITH MAX GUSTS 30-35 KT. JEE //DISCUSSION...UPDATED 18Z... STILL LOOKING AT A VERY MESSY FORECAST AS THE PIECES NECESSARY FOR WIDESPREAD STORMS ARE NOT COMPLETELY LINING UP. THE SFC LOW IS OVER IOWA WHILE ITS WARM FRONT STRETCHES FROM IOWA CITY IOWA THROUGH ORD AND ITS COLD FRONT IS OVER WESTERN MO. THE LINGERING CLOUD COVER IS INHIBITING DEVELOPMENT EARLY THIS AFTERNOON BUT THINKING STRONG LIFT FROM THE LOW PRESSURE SYSTEM WILL ALLOW STORMS TO DEVELOP. THINKING STORMS WILL GET STARTED OVER IOWA AND CENTRAL IL AND REACH THE EASTERN TERMINALS LATE THIS AFTERNOON INTO THE EARLY EVENING. FOR RFD...WILL LIKELY SEE STORMS A BIT EARLIER IN THE MID TO LATE AFTN. ONCE AGAIN SOME OF THESE STORMS MAY BE SVR WITH LARGE HAIL...DAMAGING WINDS...AND MAYBE AN ISOLATED TORNADO. THE COLD FRONT SWINGS THROUGH THIS EVENING WITH ANOTHER ROUND OF ORGANIZED STORMS EXPECTED ALONG IT. IFR VSBY AND MVFR CIGS ARE PSBL ONCE AGAIN. WINDS SHIFT TO THE SW AND W BEHIND THE FRONT WITH GUSTS UP TO 30 KT. GUSTY WEST WINDS WITH VFR CIGS AND VSBY ARE EXPECTED TOMORROW. JEE //ORD AND MDW CONFIDENCE...UPDATED 18Z... * HIGH CONFIDENCE IN SCATTERED STORMS THIS AFTN FOLLOWED BY A SEGMENT OR LINE OF STORMS THIS EVENING. MEDIUM CONFIDENCE IN COVERAGE THIS AFTERNOON AND TIMING. * MEDIUM CONFIDENCE IN WIND DIRECTION BEHIND THE SCATTERED STORMS. WINDS COULD BE CHAOTIC FOR A BRIEF PERIOD OF TIME. * HIGH CONFIDENCE IN REDUCED VSBY UNDER STORMS...MEDIUM-LOW CONFIDENCE IN CIG HEIGHTS. JEE //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... * FRIDAY NIGHT...SLIGHT CHANCE OF SHRA. MVFR POSSIBLE. NORTHWEST WINDS. * SATURDAY...DRY/VFR. SOUTHWEST WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...DRY/VFR. GUSTY SOUTH WINDS. * MONDAY...DRY/VFR. EAST WINDS. * TUESDAY...CHANCE OF SHRA/TSRA. MVFR POSSIBLE. SOUTH WINDS. * WEDNESDAY...CHANCE OF SHRA. SOUTH WINDS. && .MARINE... 416 AM...LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST TO NORTHERN LAKE MICHIGAN BY FRIDAY MORNING AS IT DEEPENS. A WARM FRONT WILL LIFT NORTH ACROSS THE CENTRAL PORTION OF THE LAKE AHEAD OF THIS LOW. EASTERLY WINDS WILL TURN SOUTHEAST THEN SOUTHERLY ACROSS THE SOUTHERN PART OF THE LAKE TODAY WITH SPEEDS STEADILY INCREASING. WITH THE LOW DEEPENING AS IT PASSES WEST OF THE LAKE...WIND SPEEDS ARE NOW EXPECTED TO REACH GALE FORCE THIS EVENING AND CONTINUE INTO FRIDAY FROM THE WEST. HOISTED A GALE WATCH THIS MORNING BUT IF TRENDS CONTINUE EXPECT A GALE WARNING TO BE NEEDED LATER TODAY. POSSIBLE GALES MAY EXTEND A BIT FURTHER NORTH THEN CURRENT WATCH...BUT WILL BE DEPENDENT ON THE TRACK OF THE LOW. WINDS DIMINISH SOME FRIDAY AND THEN DIMINISH TO 10-15KT FRIDAY NIGHT INTO SATURDAY AS THE GRADIENT RELAXES WITH HIGH PRESSURE MOVING ACROSS THE SOUTHERN LAKES AND OHIO VALLEY. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...DENSE FOG ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 3 PM THURSDAY. GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777- LMZ779...10 PM THURSDAY TO 1 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
103 PM CDT THU APR 9 2015 .MESOSCALE DISCUSSION... 1228 PM CDT CONTINUES TO BE A THREAT FOR SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING. BROAD ZONE OF WEAK ASCENT WITH WARM AIR ADVECTION CONTINUE TO SUPPORT SPORADIC DISORGANIZED THUNDERSTORM DEVELOP MIDDAY OVER NORTHERN ILLINOIS AND NORTHWEST INDIANA. WATER VAPOR IMAGERY DOES SHOW A WELL DEFINED SHORTWAVE MOVING INTO NORTHEAST MISSOURI WITH SHOWERS AND THUNDERSTORMS ALSO ASSOCIATED WITH THAT FEATURE. IT WOULD APPEAR THAT THIS SHORTWAVE AND WARM AIR ADVECTION IN ADVANCE OF IT WILL CONTINUE TO RESULT IN A PRETTY GOOD COVERAGE OF SHOWERS AND THUNDERSTORMS INTO THE AFTERNOON HOURS ACROSS THE CWA. MORNING SOUNDINGS FROM ACROSS THE REGION SHOWED A MOIST AND WEAKLY UNSTABLE AIR MASS IN PLACE WITH LITTLE/NO CAPPING INVERSION...SO IT IS LOOKING LIKE INSTABILITY WILL REMAIN FAIRLY MUTED ACROSS THE CWA TODAY AS ANY BREAKS IN CLOUDS END UP FILLING IN WITH CONVECTION. EFFECTIVE SHEAR IS SUFFICIENTLY STRONG TO SUPPORT A SEVERE THREAT AND SHEAR PROFILES WILL ONLY GROW MORE FAVORABLE WITH TIME TODAY FOR SEVERE THUNDERSTORMS AS CYCLONE INTENSIFIES. IT IS UNCLEAR WHAT ROLE THE MISSOURI LEAD SHORTWAVE WILL PLAY ON THE CONVECTIVE EVOLUTION. WHILE INSTABILITY WILL BE SOMEWHAT WEAKER THAN EARLIER ANTICIPATED THE STRENGTH OF THE APPROACHING CYCLONE AND WIND FIELDS STILL SUGGEST THERE AN APPRECIABLE SEVERE THREAT EXISTS GIVEN CONVECTIVE DEVELOPMENT. WITH SOMEWHAT LESS DEFINED FORCING IN THE WARM SECTOR...STORMS STAND A BETTER CHANCE OF BEING MORE DISCRETE WOULD RAISES THE CHANCES A BIT OF SUPERCELLS AND ATTENDANT WIND/HAIL AND POSSIBLE TORNADO THREAT...PARTICULARLY AS THE AFTERNOON WEARS ON AND SHEAR PROFILES FURTHER IMPROVE. THIS WILL PARTICULARLY BE THE CASE TOWARD 00Z AS 1KM AGL WINDS ARE PROGGED TO INCREASE TO OVER 40KT RESULTING IN A SUBSTANTIAL STRENGTHENING OF LOW LEVEL SHEAR. ASSUMING A MORE DISCRETE STORM MODE PERSISTS THROUGH THAT TIME THEN THE TORNADO THREAT WOULD BE HIGHER. IZZI && .SHORT TERM... 400 AM CDT TODAY AND TONIGHT... DENSE FOG CONTINUES IN COOL/SATURATED AIR MASS WITH NORTHEAST WINDS OFF THE LAKE THIS MORNING...WILL MAINTAIN DENSE FOG ADVISORY ALONG THE LAKE AS ISSUED. CLUSTERS OF THUNDERSTORMS WERE OCCURRING EARLY THIS MORNING ACROSS THE MIDWEST...IN A REGION OF BROAD SOUTHWESTERLY WARM/MOIST ADVECTION ATOP NEARLY STATIONARY FRONTAL BOUNDARY WHICH STRETCHES FROM THE CENTRAL PLAINS INTO SOUTHERN IOWA...THEN EAST ACROSS CENTRAL ILLINOIS AND INDIANA. THESE CLUSTERS OF STORMS WERE GENERALLY TIED TO INDIVIDUAL MINOR-AMPLITUDE MID-LEVEL SHORT WAVE FEATURES...AND ASSOCIATED LOCALIZED ENHANCED MOISTURE TRANSPORT AND ASCENT. TO THE WEST...STRONG UPPER TROUGH WAS MOVING ONTO THE PLAINS EAST OF THE ROCKIES...AND IS PROGGED TO APPROACH THE MID- UPPER MISSISSIPPI VALLEY LATE THIS AFTERNOON AS A COMPACT AND SOMEWHAT NEGATIVELY-TILTED ENERGETIC DISTURBANCE. SURFACE LOW PRESSURE IN THE VICINITY OF SOUTHWEST KANSAS AT THIS HOUR WILL DEEPEN AND LIFT TO SOUTHWESTERN WISCONSIN/FAR NORTHWEST IL PER COMPLIMENTING GUIDANCE SOLUTIONS...WITH THE FRONT LIFTING NORTH AS A WARM FRONT ACROSS THE FORECAST AREA. THIS PATTERN HAS ALL THE EARMARKS OF BEING A WIDESPREAD SEVERE WEATHER PRODUCER ACROSS THE AREA THIS AFTERNOON AND EVENING. WITH THAT SAID...QUESTIONS REMAIN WITH RESPECT TO EVOLUTION OF STORMS LATER TODAY...MAINLY DUE TO THE EXPECTATION THAT SEVERAL CLUSTERS OF STORMS WILL CONTINUE TO DEVELOP/PROPAGATE ACROSS THE AREA THROUGH MUCH OF THE DAY DUE TO PERSISTENT WARM/MOIST ADVECTION AND ASCENT IN REGION OF STEEP MID-LEVEL LAPSE RATES AHEAD OF THE DEEPENING TROUGH AND SURFACE LOW. CONVECTION ALLOWING GUIDANCE (HRRR/NMM/ARW RUNS) DEPICT SEVERAL CLUSTERS DEVELOPING AND LIFTING ACROSS THE AREA THROUGH THE MORNING AND MIDDAY HOURS...AND REGIONAL RADAR MOSAIC SEEMS TO INDICATE THIS WILL BE THE TREND AT LEAST THROUGH THIS MORNING. THUS WHILE SYNOPTIC FEATURES WILL BE STRONG...MESOSCALE BOUNDARIES AND FORCING REMAIN UNCLEAR AT THIS TIME. STILL...STRONG FORCING IN ADVANCE OF COLD FRONT COUPLED WITH STRONG ASCENT ASSOCIATED WITH COMPACT WAVE SHOULD BE CAPABLE OF GENERATING ORGANIZED SEVERE STORMS LATER THIS AFTERNOON. 00Z NAM FORECAST SOUNDINGS INDICATE WARM SECTOR MLCAPES AROUND 1500-2000 J/KG...WITH AMPLE DEEP AND LOW LEVEL SHEAR. SPC NOTES SOME UNCERTAINTY WITH RESPECT TO STORM MODE...LINE SEGMENTS AS OPPOSED TO DISCRETE CELLS...THOUGH SUPERCELLULAR CHARACTERISTICS ARE LIKELY GIVEN THE ENVIRONMENT. DAMAGING WINDS FROM LINES/LINE SEGMENTS LOOKS TO BE THE MOST WIDESPREAD THREAT...THOUGH NORTHERN IL/SOUTHERN WI...WHERE WINDS WILL MOST LIKELY BE BACKED MORE STRONGLY AHEAD OF THE LOW...WILL STILL HAVE A REAL TORNADO POTENTIAL. STORMS WILL LIKELY EVOLVE UPSCALE INTO SQUALL-LINE AS COLD FRONT MOVES ACROSS THE AREA EARLY THIS EVENING...WITH THUNDERSTORM/SEVERE THREAT QUICKLY WINDING DOWN BEFORE MIDNIGHT AFTER FROPA. RATZER && .LONG TERM... 416 AM CDT... FRIDAY THROUGH WEDNESDAY... DRIER AND MUCH COOLER AIR SPREADS IN BEHIND THE COLD FRONT TONIGHT... AS UPPER TROUGH LIFTS NORTHEAST ACROSS THE NORTHERN LAKES OVERNIGHT. A SECOND FAIRLY STRONG NORTHERN STREAM SHORT WAVE DROPS INTO THE BACK SIDE OF THE TROUGH FRIDAY...AND ROTATES SOUTHEASTWARD ACROSS SOUTHERN WI/NORTHERN IL AND LAKE MICHIGAN THROUGH FRIDAY EVENING. FORECAST SOUNDINGS INDICATE STEEP LOW LEVEL LAPSE RATES DEVELOPING BENEATH COOL MID LEVEL AIR ASSOCIATED WITH THE TROUGH... WHICH DESPITE RELATIVELY DRY LOW LEVEL AIR MAY BE ABLE TO PRODUCE A FEW SPRINKLES OR LIGHT SHOWERS NEAR THE IL/WI BORDER DURING THE AFTERNOON AND EARLY EVENING HOURS BEFORE DIURNAL STABILIZATION OCCURS. TEMPS RANGING FROM THE UPPER 50S NORTH TO LOWER 60S SOUTH MAY EVEN FALL A BIT IN THE AFTERNOON WITH THE PASSAGE OF A SECONDARY SURFACE TROUGH/COLD FRONT. HIGH PRESSURE THEN BUILDS IN LATER FRIDAY NIGHT AND SATURDAY...WITH DRY WEATHER AND TEMPS CLOSE TO NORMAL. LONGER RANGE GUIDANCE IN BETTER AGREEMENT IN MOVING HIGH OFF TO THE EAST ON SUNDAY AND DEVELOPING SOUTH-SOUTHEAST LOW LEVEL FLOW AHEAD OF AN APPROACHING COLD FRONT. THIS PRESENTS THE NEXT CHANCE OF PRECIP...MAINLY SUNDAY NIGHT BEFORE THE FRONT MOVES OFF TO THE EAST ON MONDAY AND HIGH PRESSURE SPREADS BACK IN. MODELS BECOME MORE DIVERGENT TUESDAY-WEDNESDAY WITH TIMING OF AN UPPER LOW LIFTING NORTHEAST ACROSS THE REGION. PRECIP CHANCES GENERALLY LOOK TO INCREASE BY MID-WEEK AS THIS SYSTEM APPROACHES...THOUGH GENERAL MODEL TREND HAS BEEN TO SLOW THINGS DOWN. IT DOES LOOK LIKE WE WARM UP NICELY IN ADVANCE OF THIS SYSTEM...WITH 70S IN THE FORECAST FOR TUE-WED. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * SCATTERED STORMS EXPECTED LATE THIS AFTN AROUND 23Z...WITH THE FINAL ROUND OF STORMS MOVING THROUGH ARND 2Z. SOME OF THESE STORMS COULD BE SEVERE. * GUSTY SSW WINDS WITH GUSTS ARND 25 KT. * IFR CIGS AND VSBY PSBL WITH TSRA. * GUSTY WINDS BCMG SW TO W ARND MIDNIGHT WITH MAX GUSTS 30-35 KT. JEE //DISCUSSION...UPDATED 18Z... STILL LOOKING AT A VERY MESSY FORECAST AS THE PIECES NECESSARY FOR WIDESPREAD STORMS ARE NOT COMPLETELY LINING UP. THE SFC LOW IS OVER IOWA WHILE ITS WARM FRONT STRETCHES FROM IOWA CITY IOWA THROUGH ORD AND ITS COLD FRONT IS OVER WESTERN MO. THE LINGERING CLOUD COVER IS INHIBITING DEVELOPMENT EARLY THIS AFTERNOON BUT THINKING STRONG LIFT FROM THE LOW PRESSURE SYSTEM WILL ALLOW STORMS TO DEVELOP. THINKING STORMS WILL GET STARTED OVER IOWA AND CENTRAL IL AND REACH THE EASTERN TERMINALS LATE THIS AFTERNOON INTO THE EARLY EVENING. FOR RFD...WILL LIKELY SEE STORMS A BIT EARLIER IN THE MID TO LATE AFTN. ONCE AGAIN SOME OF THESE STORMS MAY BE SVR WITH LARGE HAIL...DAMAGING WINDS...AND MAYBE AN ISOLATED TORNADO. THE COLD FRONT SWINGS THROUGH THIS EVENING WITH ANOTHER ROUND OF ORGANIZED STORMS EXPECTED ALONG IT. IFR VSBY AND MVFR CIGS ARE PSBL ONCE AGAIN. WINDS SHIFT TO THE SW AND W BEHIND THE FRONT WITH GUSTS UP TO 30 KT. GUSTY WEST WINDS WITH VFR CIGS AND VSBY ARE EXPECTED TOMORROW. JEE //ORD AND MDW CONFIDENCE...UPDATED 18Z... * HIGH CONFIDENCE IN SCATTERED STORMS THIS AFTN FOLLOWED BY A SEGMENT OR LINE OF STORMS THIS EVENING. MEDIUM CONFIDENCE IN COVERAGE THIS AFTERNOON AND TIMING. * MEDIUM CONFIDENCE IN WIND DIRECTION BEHIND THE SCATTERED STORMS. WINDS COULD BE CHAOTIC FOR A BRIEF PERIOD OF TIME. * HIGH CONFIDENCE IN REDUCED VSBY UNDER STORMS...MEDIUM-LOW CONFIDENCE IN CIG HEIGHTS. JEE //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... * FRIDAY NIGHT...SLIGHT CHANCE OF SHRA. MVFR POSSIBLE. NORTHWEST WINDS. * SATURDAY...DRY/VFR. SOUTHWEST WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...DRY/VFR. GUSTY SOUTH WINDS. * MONDAY...DRY/VFR. EAST WINDS. * TUESDAY...CHANCE OF SHRA/TSRA. MVFR POSSIBLE. SOUTH WINDS. * WEDNESDAY...CHANCE OF SHRA. SOUTH WINDS. && .MARINE... 416 AM...LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST TO NORTHERN LAKE MICHIGAN BY FRIDAY MORNING AS IT DEEPENS. A WARM FRONT WILL LIFT NORTH ACROSS THE CENTRAL PORTION OF THE LAKE AHEAD OF THIS LOW. EASTERLY WINDS WILL TURN SOUTHEAST THEN SOUTHERLY ACROSS THE SOUTHERN PART OF THE LAKE TODAY WITH SPEEDS STEADILY INCREASING. WITH THE LOW DEEPENING AS IT PASSES WEST OF THE LAKE...WIND SPEEDS ARE NOW EXPECTED TO REACH GALE FORCE THIS EVENING AND CONTINUE INTO FRIDAY FROM THE WEST. HOISTED A GALE WATCH THIS MORNING BUT IF TRENDS CONTINUE EXPECT A GALE WARNING TO BE NEEDED LATER TODAY. POSSIBLE GALES MAY EXTEND A BIT FURTHER NORTH THEN CURRENT WATCH...BUT WILL BE DEPENDENT ON THE TRACK OF THE LOW. WINDS DIMINISH SOME FRIDAY AND THEN DIMINISH TO 10-15KT FRIDAY NIGHT INTO SATURDAY AS THE GRADIENT RELAXES WITH HIGH PRESSURE MOVING ACROSS THE SOUTHERN LAKES AND OHIO VALLEY. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...DENSE FOG ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 3 PM THURSDAY. GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777- LMZ779...10 PM THURSDAY TO 1 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1255 PM CDT Thu Apr 9 2015 .UPDATE... ISSUED AT 1007 AM CDT THU APR 9 2015 15z/10am surface analysis shows 1000mb low centered just north of Kansas City, with warm front extending eastward into northern Illinois. Front has now lifted north of the KILX CWA, placing the entire area firmly in the warm sector. Widespread early morning convection is in the process of exiting into northern Indiana, leaving behind just scattered showers/storms for the time being. Further upstream, the next upper-level impulse is triggering a renewed round of convection across western Missouri. Based on timing tools and the latest HRRR guidance, this activity will move into the SW CWA between 17z and 18z. Once this wave departs, attention will turn to the approaching cold front which is still on target for a late afternoon/early evening arrival. Airmass ahead of the front will become moderately unstable and highly sheared, so threat for strong to severe thunderstorms is still present. Current indications suggest the primary time frame will be from 21z/4pm through 03z/10pm. Damaging wind gusts will be the main threat with the storms, although large hail and isolated tornadoes will also be possible as the cells first begin to develop. Made some changes to hourly PoPs to better reflect current and expected trends, but changes were minor and did not require a full zone update at this time. && .SHORT TERM...(Today) ISSUED AT 303 AM CDT THU APR 9 2015 Latest surface analysis shows the warm front has lifted to the I-74 corridor early this morning with a chaotic wind field across most of the forecast area. Not sure what the affect the current scattered convection will have on the position of the frontal boundary thru the morning hours, but most of the models suggest a continued slow push to the north as the main surface low tracks northeast to central Iowa by late this morning. Current thinking is that the cold front will be positioned just west of the Mississippi River by 21z with surface based convection developing ahead of the front at that time as well. Better low level helicity fields supportive of discrete supercells and possible tornadoes looks to be closer to the track of the surface low...which by late afternoon is expected to be in far southwest Wisconsin or northwest Illinois. That would put the threat for more persistent low level rotating storms just to our west and north. However, still plenty of shear ahead of the frontal boundary this afternoon and early this evening to promote damaging straight line winds as the storms transition into more of a linear system. Temperature-wise, with the warm front to our north this afternoon, will continue to go with the warmer guid values most areas. Latest model data now suggests the backedge of the precip pushes out of our far southeast counties by midnight, so will extend the Flash Flood Watch until that time this evening. && .LONG TERM...(Tonight through Wednesday) ISSUED AT 303 AM CDT THU APR 9 2015 Showers and thunderstorms, possibly severe, will be ongoing across at least the eastern half of the forecast area to start this evening. Despite the short forecast range, there is still some spread in the expected cold frontal timing. However, it appears reasonable that the front will lie somewhere between the Illinois River and the I-55 corridor by 00Z Friday. Sped up the decrease in shower/storm chances by mid evening, and I would not be surprised to see the precipitation chances taper off a few hours earlier, especially if the squall line gets a head of steam and trends further ahead of the front than current progs. Once the front clears the area tonight, quiet conditions, along with much cooler and less humid air will build across the region into Sunday. These conditions will be driven by a large area of high pressure of Canadian origin. While conditions will be notably cooler/less humid, they will still be at or above normal for early April. The next precipitation chances will arrive later Sunday into Sunday night as a cold front is dragged across the area. While this front is still expected to stall out at it begins to parallel the upper-level flow, model trends suggest the front will stall out further south than previously anticipated. If these trends persist, Monday and Monday night will end up dry. For now, have reduced but not eliminated PoPs Monday/Monday night until we see if this recent model trend sticks. A slow moving upper-level disturbance will push the front back into the area by Tuesday, bringing renewed shower/storm chances. The front and/or upper level disturbances will keep the rain chances going into the end of the work week. Temperatures should remain at or above normal through the period. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) ISSUED AT 1255 PM CDT THU APR 9 2015 Strong southwesterly winds will prevail this afternoon, with frequent gusts to between 25 and 35kt. Convection will initially be isolated, but will become more widespread by late afternoon into the early evening as a cold front moves in from the west. High-res models are in good agreement that a line of storms will develop along the advancing front near/west of the Mississippi River by mid to late afternoon, then push eastward into Illinois after that. Based on HRRR timing, have included a TEMPO group for thunder at KPIA between 23z and 01z, then further east to KCMI between 02z and 04z. Once storms pass, winds will veer to the west and increase and remain quite gusty through the night. In addition, MVFR ceilings currently across western Iowa into Kansas will spill eastward, with forecast soundings suggesting low clouds remaining in place until close to dawn Friday. After that, am expecting mostly clear skies with continued brisk westerly winds Friday morning. && .ILX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH through late tonight FOR ILZ054>057-061>063- 066>068-071>073. && $$ UPDATE...Barnes SHORT TERM...Smith LONG TERM...Bak AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1105 AM CDT THU APR 9 2015 .SHORT TERM... 400 AM CDT TODAY AND TONIGHT... DENSE FOG CONTINUES IN COOL/SATURATED AIR MASS WITH NORTHEAST WINDS OFF THE LAKE THIS MORNING...WILL MAINTAIN DENSE FOG ADVISORY ALONG THE LAKE AS ISSUED. CLUSTERS OF THUNDERSTORMS WERE OCCURRING EARLY THIS MORNING ACROSS THE MIDWEST...IN A REGION OF BROAD SOUTHWESTERLY WARM/MOIST ADVECTION ATOP NEARLY STATIONARY FRONTAL BOUNDARY WHICH STRETCHES FROM THE CENTRAL PLAINS INTO SOUTHERN IOWA...THEN EAST ACROSS CENTRAL ILLINOIS AND INDIANA. THESE CLUSTERS OF STORMS WERE GENERALLY TIED TO INDIVIDUAL MINOR-AMPLITUDE MID-LEVEL SHORT WAVE FEATURES...AND ASSOCIATED LOCALIZED ENHANCED MOISTURE TRANSPORT AND ASCENT. TO THE WEST...STRONG UPPER TROUGH WAS MOVING ONTO THE PLAINS EAST OF THE ROCKIES...AND IS PROGGED TO APPROACH THE MID- UPPER MISSISSIPPI VALLEY LATE THIS AFTERNOON AS A COMPACT AND SOMEWHAT NEGATIVELY-TILTED ENERGETIC DISTURBANCE. SURFACE LOW PRESSURE IN THE VICINITY OF SOUTHWEST KANSAS AT THIS HOUR WILL DEEPEN AND LIFT TO SOUTHWESTERN WISCONSIN/FAR NORTHWEST IL PER COMPLIMENTING GUIDANCE SOLUTIONS...WITH THE FRONT LIFTING NORTH AS A WARM FRONT ACROSS THE FORECAST AREA. THIS PATTERN HAS ALL THE EARMARKS OF BEING A WIDESPREAD SEVERE WEATHER PRODUCER ACROSS THE AREA THIS AFTERNOON AND EVENING. WITH THAT SAID...QUESTIONS REMAIN WITH RESPECT TO EVOLUTION OF STORMS LATER TODAY...MAINLY DUE TO THE EXPECTATION THAT SEVERAL CLUSTERS OF STORMS WILL CONTINUE TO DEVELOP/PROPAGATE ACROSS THE AREA THROUGH MUCH OF THE DAY DUE TO PERSISTENT WARM/MOIST ADVECTION AND ASCENT IN REGION OF STEEP MID-LEVEL LAPSE RATES AHEAD OF THE DEEPENING TROUGH AND SURFACE LOW. CONVECTION ALLOWING GUIDANCE (HRRR/NMM/ARW RUNS) DEPICT SEVERAL CLUSTERS DEVELOPING AND LIFTING ACROSS THE AREA THROUGH THE MORNING AND MIDDAY HOURS...AND REGIONAL RADAR MOSAIC SEEMS TO INDICATE THIS WILL BE THE TREND AT LEAST THROUGH THIS MORNING. THUS WHILE SYNOPTIC FEATURES WILL BE STRONG...MESOSCALE BOUNDARIES AND FORCING REMAIN UNCLEAR AT THIS TIME. STILL...STRONG FORCING IN ADVANCE OF COLD FRONT COUPLED WITH STRONG ASCENT ASSOCIATED WITH COMPACT WAVE SHOULD BE CAPABLE OF GENERATING ORGANIZED SEVERE STORMS LATER THIS AFTERNOON. 00Z NAM FORECAST SOUNDINGS INDICATE WARM SECTOR MLCAPES AROUND 1500-2000 J/KG...WITH AMPLE DEEP AND LOW LEVEL SHEAR. SPC NOTES SOME UNCERTAINTY WITH RESPECT TO STORM MODE...LINE SEGMENTS AS OPPOSED TO DISCRETE CELLS...THOUGH SUPERCELLULAR CHARACTERISTICS ARE LIKELY GIVEN THE ENVIRONMENT. DAMAGING WINDS FROM LINES/LINE SEGMENTS LOOKS TO BE THE MOST WIDESPREAD THREAT...THOUGH NORTHERN IL/SOUTHERN WI...WHERE WINDS WILL MOST LIKELY BE BACKED MORE STRONGLY AHEAD OF THE LOW...WILL STILL HAVE A REAL TORNADO POTENTIAL. STORMS WILL LIKELY EVOLVE UPSCALE INTO SQUALL-LINE AS COLD FRONT MOVES ACROSS THE AREA EARLY THIS EVENING...WITH THUNDERSTORM/SEVERE THREAT QUICKLY WINDING DOWN BEFORE MIDNIGHT AFTER FROPA. RATZER && .LONG TERM... 416 AM CDT... FRIDAY THROUGH WEDNESDAY... DRIER AND MUCH COOLER AIR SPREADS IN BEHIND THE COLD FRONT TONIGHT... AS UPPER TROUGH LIFTS NORTHEAST ACROSS THE NORTHERN LAKES OVERNIGHT. A SECOND FAIRLY STRONG NORTHERN STREAM SHORT WAVE DROPS INTO THE BACK SIDE OF THE TROUGH FRIDAY...AND ROTATES SOUTHEASTWARD ACROSS SOUTHERN WI/NORTHERN IL AND LAKE MICHIGAN THROUGH FRIDAY EVENING. FORECAST SOUNDINGS INDICATE STEEP LOW LEVEL LAPSE RATES DEVELOPING BENEATH COOL MID LEVEL AIR ASSOCIATED WITH THE TROUGH... WHICH DESPITE RELATIVELY DRY LOW LEVEL AIR MAY BE ABLE TO PRODUCE A FEW SPRINKLES OR LIGHT SHOWERS NEAR THE IL/WI BORDER DURING THE AFTERNOON AND EARLY EVENING HOURS BEFORE DIURNAL STABILIZATION OCCURS. TEMPS RANGING FROM THE UPPER 50S NORTH TO LOWER 60S SOUTH MAY EVEN FALL A BIT IN THE AFTERNOON WITH THE PASSAGE OF A SECONDARY SURFACE TROUGH/COLD FRONT. HIGH PRESSURE THEN BUILDS IN LATER FRIDAY NIGHT AND SATURDAY...WITH DRY WEATHER AND TEMPS CLOSE TO NORMAL. LONGER RANGE GUIDANCE IN BETTER AGREEMENT IN MOVING HIGH OFF TO THE EAST ON SUNDAY AND DEVELOPING SOUTH-SOUTHEAST LOW LEVEL FLOW AHEAD OF AN APPROACHING COLD FRONT. THIS PRESENTS THE NEXT CHANCE OF PRECIP...MAINLY SUNDAY NIGHT BEFORE THE FRONT MOVES OFF TO THE EAST ON MONDAY AND HIGH PRESSURE SPREADS BACK IN. MODELS BECOME MORE DIVERGENT TUESDAY-WEDNESDAY WITH TIMING OF AN UPPER LOW LIFTING NORTHEAST ACROSS THE REGION. PRECIP CHANCES GENERALLY LOOK TO INCREASE BY MID-WEEK AS THIS SYSTEM APPROACHES...THOUGH GENERAL MODEL TREND HAS BEEN TO SLOW THINGS DOWN. IT DOES LOOK LIKE WE WARM UP NICELY IN ADVANCE OF THIS SYSTEM...WITH 70S IN THE FORECAST FOR TUE-WED. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * ONE FINAL WAVE OF TS PUSHING EAST BY LATE MORNING. * IFR VSBY IMPROVING TO VFR LATER THIS MORNING. * SE WINDS BCMG SOUTH TO SW AND GUSTING TO ARND 25 KT. WINDS BCMG WEST OVERNIGHT WITH GUSTS UP TO 30 KT. * ANOTHER ROUND OR TWO OF THUNDERSTORMS THIS AFTERNOON AND EVENING. SEVERE STORMS ARE POSSIBLE. JEE //DISCUSSION...UPDATED 12Z... AREA OF THUNDERSTORMS WILL MOVE ACROSS THE TERMINALS OVER THE NEXT FEW HOURS. END TIME IN THE 14Z-15Z LOOKS ON TRACK WITH ADDITIONAL DEVELOPMENT NEAR VYS. POSSIBLE FOR ADDITIONAL ISOLATED ACTIVITY LATE THIS MORNING INTO THIS AFTERNOON BUT CONFIDENCE IS LOW AND WILL MAINTAIN DRY FORECAST UNTIL LATE THIS AFTERNOON...WHEN A LINE OF STRONG/SEVERE THUNDERSTORMS IS EXPECTED DEVELOP AHEAD OF A COLD FRONT AND MOVE ACROSS THE TERMINALS THRU EARLY THIS EVENING. EAST WINDS WILL TURN SOUTHEAST THIS MORNING AND SOUTHERLY BY LATE MORNING. SPEEDS/GUSTS WILL BEGIN TO INCREASE FROM THE SOUTH/ SOUTHWEST THIS AFTERNOON AND THEN BECOME STRONG THIS EVENING WITH SPEEDS 20-25KTS POSSIBLE WITH GUSTS 30-35KTS. DIRECTIONS WILL TURN MORE WESTERLY OVERNIGHT WITH SPEEDS DIMINISHING SOME OVERNIGHT. CIGS/VIS ON THE DECK ARE EXPECTED TO IMPROVE QUICKLY THIS MORNING BUT SPECIFIC HEIGHTS/TIMING IS LOW AND WILL LIKELY REQUIRE SOME UPDATES THIS MORNING. CIGS SHOULD BECOME MVFR OR BETTER BY LATE MORNING WITH IFR/LIFR POSSIBLE WITH THUNDERSTORMS THIS EVENING. CMS //ORD AND MDW CONFIDENCE...UPDATED 16Z... * HIGH CONFIDENCE IN ROUNDS OF THUNDERSTORMS THROUGH THIS EVENING. MEDIUM CONFIDENCE IN TIMING...COVERAGE...AND SEVERITY. * MEDIUM CONFIDENCE IN WINDS...WINDS THIS AFTN MAY BE MORE CHAOTIC WITH THUNDERSTORMS...AND WINDS MAY BE GUSTIER THIS EVENING AND OVERNIGHT. JEE //OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z... * FRIDAY NIGHT...SLIGHT CHANCE OF SHRA. MVFR POSSIBLE. NORTHWEST WINDS. * SATURDAY...DRY/VFR. SOUTHWEST WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...DRY/VFR. GUSTY SOUTH WINDS. * MONDAY...DRY/VFR. EAST WINDS. * TUESDAY...CHANCE OF SHRA/TSRA. MVFR POSSIBLE. SOUTH WINDS. * WEDNESDAY...CHANCE OF SHRA. SOUTH WINDS. && .MARINE... 416 AM...LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST TO NORTHERN LAKE MICHIGAN BY FRIDAY MORNING AS IT DEEPENS. A WARM FRONT WILL LIFT NORTH ACROSS THE CENTRAL PORTION OF THE LAKE AHEAD OF THIS LOW. EASTERLY WINDS WILL TURN SOUTHEAST THEN SOUTHERLY ACROSS THE SOUTHERN PART OF THE LAKE TODAY WITH SPEEDS STEADILY INCREASING. WITH THE LOW DEEPENING AS IT PASSES WEST OF THE LAKE...WIND SPEEDS ARE NOW EXPECTED TO REACH GALE FORCE THIS EVENING AND CONTINUE INTO FRIDAY FROM THE WEST. HOISTED A GALE WATCH THIS MORNING BUT IF TRENDS CONTINUE EXPECT A GALE WARNING TO BE NEEDED LATER TODAY. POSSIBLE GALES MAY EXTEND A BIT FURTHER NORTH THEN CURRENT WATCH...BUT WILL BE DEPENDENT ON THE TRACK OF THE LOW. WINDS DIMINISH SOME FRIDAY AND THEN DIMINISH TO 10-15KT FRIDAY NIGHT INTO SATURDAY AS THE GRADIENT RELAXES WITH HIGH PRESSURE MOVING ACROSS THE SOUTHERN LAKES AND OHIO VALLEY. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...DENSE FOG ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 3 PM THURSDAY. GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777- LMZ779...10 PM THURSDAY TO 1 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1007 AM CDT Thu Apr 9 2015 .UPDATE... ISSUED AT 1007 AM CDT THU APR 9 2015 15z/10am surface analysis shows 1000mb low centered just north of Kansas City, with warm front extending eastward into northern Illinois. Front has now lifted north of the KILX CWA, placing the entire area firmly in the warm sector. Widespread early morning convection is in the process of exiting into northern Indiana, leaving behind just scattered showers/storms for the time being. Further upstream, the next upper-level impulse is triggering a renewed round of convection across western Missouri. Based on timing tools and the latest HRRR guidance, this activity will move into the SW CWA between 17z and 18z. Once this wave departs, attention will turn to the approaching cold front which is still on target for a late afternoon/early evening arrival. Airmass ahead of the front will become moderately unstable and highly sheared, so threat for strong to severe thunderstorms is still present. Current indications suggest the primary time frame will be from 21z/4pm through 03z/10pm. Damaging wind gusts will be the main threat with the storms, although large hail and isolated tornadoes will also be possible as the cells first begin to develop. Made some changes to hourly PoPs to better reflect current and expected trends, but changes were minor and did not require a full zone update at this time. && .SHORT TERM...(Today) ISSUED AT 303 AM CDT THU APR 9 2015 Latest surface analysis shows the warm front has lifted to the I-74 corridor early this morning with a chaotic wind field across most of the forecast area. Not sure what the affect the current scattered convection will have on the position of the frontal boundary thru the morning hours, but most of the models suggest a continued slow push to the north as the main surface low tracks northeast to central Iowa by late this morning. Current thinking is that the cold front will be positioned just west of the Mississippi River by 21z with surface based convection developing ahead of the front at that time as well. Better low level helicity fields supportive of discrete supercells and possible tornadoes looks to be closer to the track of the surface low...which by late afternoon is expected to be in far southwest Wisconsin or northwest Illinois. That would put the threat for more persistent low level rotating storms just to our west and north. However, still plenty of shear ahead of the frontal boundary this afternoon and early this evening to promote damaging straight line winds as the storms transition into more of a linear system. Temperature-wise, with the warm front to our north this afternoon, will continue to go with the warmer guid values most areas. Latest model data now suggests the backedge of the precip pushes out of our far southeast counties by midnight, so will extend the Flash Flood Watch until that time this evening. && .LONG TERM...(Tonight through Wednesday) ISSUED AT 303 AM CDT THU APR 9 2015 Showers and thunderstorms, possibly severe, will be ongoing across at least the eastern half of the forecast area to start this evening. Despite the short forecast range, there is still some spread in the expected cold frontal timing. However, it appears reasonable that the front will lie somewhere between the Illinois River and the I-55 corridor by 00Z Friday. Sped up the decrease in shower/storm chances by mid evening, and I would not be surprised to see the precipitation chances taper off a few hours earlier, especially if the squall line gets a head of steam and trends further ahead of the front than current progs. Once the front clears the area tonight, quiet conditions, along with much cooler and less humid air will build across the region into Sunday. These conditions will be driven by a large area of high pressure of Canadian origin. While conditions will be notably cooler/less humid, they will still be at or above normal for early April. The next precipitation chances will arrive later Sunday into Sunday night as a cold front is dragged across the area. While this front is still expected to stall out at it begins to parallel the upper-level flow, model trends suggest the front will stall out further south than previously anticipated. If these trends persist, Monday and Monday night will end up dry. For now, have reduced but not eliminated PoPs Monday/Monday night until we see if this recent model trend sticks. A slow moving upper-level disturbance will push the front back into the area by Tuesday, bringing renewed shower/storm chances. The front and/or upper level disturbances will keep the rain chances going into the end of the work week. Temperatures should remain at or above normal through the period. && .AVIATION...(For the 12Z TAFS through 12Z Friday morning) ISSUED AT 640 AM CDT THU APR 9 2015 Active weather day across the region with scattered thunderstorms this morning, with storms expected to redevelop this afternoon and evening along a cold front. Some of those storms will be severe with damaging wind gusts and hail possible. VFR cigs expected outside any storms, however, with any strong storm, look for cigs and vsbys to briefly drop to IFR at times. Gradient winds are expected to be rather gusty today out of the south and southwest with prevailing speeds of 15 to 25 kts with gusts around 35 kts at times. Cold front timing looks to be around the PIA site by 23z and should be east of our TAF sites by 02z. It appears the strongest storms will be about an hour or two ahead of the actual cold front this afternoon and evening. Look for sfc winds to become southwest with FROPA and with the storm system expected to deepen, a rather tight pressure gradient will produce a period of strong and gusty winds out of the southwest just after the passage of the cold front late this afternoon into the evening. Some gusts may be around 35 kts at times just after the front shifts to the east of a TAF sites early this evening. Expect the strong gusts to slowly subside, but not until after 03z. && .ILX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH through late tonight FOR ILZ054>057-061>063- 066>068-071>073. && $$ UPDATE...Barnes SHORT TERM...Smith LONG TERM...Bak AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
401 AM CDT THU APR 9 2015 .SHORT TERM... 400 AM CDT TODAY AND TONIGHT... DENSE FOG CONTINUES IN COOL/SATURATED AIR MASS WITH NORTHEAST WINDS OFF THE LAKE THIS MORNING...WILL MAINTAIN DENSE FOG ADVISORY ALONG THE LAKE AS ISSUED. CLUSTERS OF THUNDERSTORMS WERE OCCURRING EARLY THIS MORNING ACROSS THE MIDWEST...IN A REGION OF BROAD SOUTHWESTERLY WARM/MOIST ADVECTION ATOP NEARLY STATIONARY FRONTAL BOUNDARY WHICH STRETCHES FROM THE CENTRAL PLAINS INTO SOUTHERN IOWA...THEN EAST ACROSS CENTRAL ILLINOIS AND INDIANA. THESE CLUSTERS OF STORMS WERE GENERALLY TIED TO INDIVIDUAL MINOR-AMPLITUDE MID-LEVEL SHORT WAVE FEATURES...AND ASSOCIATED LOCALIZED ENHANCED MOISTURE TRANSPORT AND ASCENT. TO THE WEST...STRONG UPPER TROUGH WAS MOVING ONTO THE PLAINS EAST OF THE ROCKIES...AND IS PROGGED TO APPROACH THE MID- UPPER MISSISSIPPI VALLEY LATE THIS AFTERNOON AS A COMPACT AND SOMEWHAT NEGATIVELY-TILTED ENERGETIC DISTURBANCE. SURFACE LOW PRESSURE IN THE VICINITY OF SOUTHWEST KANSAS AT THIS HOUR WILL DEEPEN AND LIFT TO SOUTHWESTERN WISCONSIN/FAR NORTHWEST IL PER COMPLIMENTING GUIDANCE SOLUTIONS...WITH THE FRONT LIFTING NORTH AS A WARM FRONT ACROSS THE FORECAST AREA. THIS PATTERN HAS ALL THE EARMARKS OF BEING A WIDESPREAD SEVERE WEATHER PRODUCER ACROSS THE AREA THIS AFTERNOON AND EVENING. WITH THAT SAID...QUESTIONS REMAIN WITH RESPECT TO EVOLUTION OF STORMS LATER TODAY...MAINLY DUE TO THE EXPECTATION THAT SEVERAL CLUSTERS OF STORMS WILL CONTINUE TO DEVELOP/PROPAGATE ACROSS THE AREA THROUGH MUCH OF THE DAY DUE TO PERSISTENT WARM/MOIST ADVECTION AND ASCENT IN REGION OF STEEP MID-LEVEL LAPSE RATES AHEAD OF THE DEEPENING TROUGH AND SURFACE LOW. CONVECTION ALLOWING GUIDANCE (HRRR/NMM/ARW RUNS) DEPICT SEVERAL CLUSTERS DEVELOPING AND LIFTING ACROSS THE AREA THROUGH THE MORNING AND MIDDAY HOURS...AND REGIONAL RADAR MOSAIC SEEMS TO INDICATE THIS WILL BE THE TREND AT LEAST THROUGH THIS MORNING. THUS WHILE SYNOPTIC FEATURES WILL BE STRONG...MESOSCALE BOUNDARIES AND FORCING REMAIN UNCLEAR AT THIS TIME. STILL...STRONG FORCING IN ADVANCE OF COLD FRONT COUPLED WITH STRONG ASCENT ASSOCIATED WITH COMPACT WAVE SHOULD BE CAPABLE OF GENERATING ORGANIZED SEVERE STORMS LATER THIS AFTERNOON. 00Z NAM FORECAST SOUNDINGS INDICATE WARM SECTOR MLCAPES AROUND 1500-2000 J/KG...WITH AMPLE DEEP AND LOW LEVEL SHEAR. SPC NOTES SOME UNCERTAINTY WITH RESPECT TO STORM MODE...LINE SEGMENTS AS OPPOSED TO DISCRETE CELLS...THOUGH SUPERCELLULAR CHARACTERISTICS ARE LIKELY GIVEN THE ENVIRONMENT. DAMAGING WINDS FROM LINES/LINE SEGMENTS LOOKS TO BE THE MOST WIDESPREAD THREAT...THOUGH NORTHERN IL/SOUTHERN WI...WHERE WINDS WILL MOST LIKELY BE BACKED MORE STRONGLY AHEAD OF THE LOW...WILL STILL HAVE A REAL TORNADO POTENTIAL. STORMS WILL LIKELY EVOLVE UPSCALE INTO SQUALL-LINE AS COLD FRONT MOVES ACROSS THE AREA EARLY THIS EVENING...WITH THUNDERSTORM/SEVERE THREAT QUICKLY WINDING DOWN BEFORE MIDNIGHT AFTER FROPA. RATZER && .LONG TERM... FRIDAY THROUGH SATURDAY... FORECAST CONFIDENCE HIGH. A POTENT SHORTWAVE WILL ROLL THROUGH SOUTHERN WI ON FRIDAY. THE CYCLONIC FLOW AND STEEP LOW LEVEL LAPSE RATES WILL LEAD TO PLENTY OF DIURNAL CUMULUS CLOUDS. A FEW SHOWERS ARE POSSIBLE TOWARD NORTHEAST IL CLOSER TO THE VORTICITY MAXIMUM. SURFACE HIGH PRESSURE WILL SPREAD INTO THE MIDWEST FRIDAY NIGHT THROUGH SATURDAY AND BRING QUIET WEATHER. CLEAR SKIES FRIDAY NIGHT WILL ALLOW TEMPS TO DROP INTO THE LOWER TO MID 30S... COLDEST NEAR THE WI BORDER. TEMPERATURES SHOULD REBOUND INTO THE LOWER 60S SATURDAY WITH WEAK WARM AIR ADVECTION OVER THE AREA. SUNDAY... FORECAST CONFIDENCE HIGH. SOUTHERLY WINDS WILL INCREASE AHEAD OF A MID LEVEL SHORTWAVE AND AN ASSOCIATED SURFACE LOW PRESSURE TROUGH SWINGING THROUGH THE UPPER MIDWEST AND GREAT LAKES REGION. LOW LEVELS ARE EXPECTED TO BE DRY... SO NO PRECIP IS ANTICIPATED ACROSS NORTHEAST IL DURING THE DAY. LIGHT SHOWERS WILL BE POSSIBLE SUNDAY NIGHT AS THE SURFACE TROUGH PASSES THROUGH THE AREA. MODELS SOUNDINGS SHOW MINIMAL INSTABILITY SO I LEFT OUT THUNDER. MONDAY THROUGH TUESDAY... FORECAST CONFIDENCE MEDIUM. MODELS ARE SLOWING DOWN THE SPEED OF THE WARM FRONTAL PRECIP INTO CENTRAL IL ON MONDAY. THUS... CHANCES FOR SHOWERS AND THUNDERSTORMS ARE DECREASING. BY MONDAY NIGHT... THE WARM FRONT WILL MAKE IT INTO EITHER NORTHERN IL OR SOUTHERN WI. THIS WILL ALLOW FOR A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA THROUGH TUESDAY NIGHT. THERE IS A POSSIBILITY FOR SEVERE WITH THIS SYSTEM AND IT WILL NEED TO BE WATCHED. MRC && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * SCATTERED THUNDERSTORMS THRU MID MORNING. * STRONG/SEVERE THUNDERSTORMS LATE AFTERNOON/EARLY EVENING. * IFR/LIFR THRU MID MORNING. * EAST WINDS BECOMING SOUTHEAST THIS MORNING...THEN STRONG/GUSTY SOUTHWEST THIS AFTERNOON. CMS //DISCUSSION...UPDATED 06Z... SHOWERS/THUNDERSTORMS ACROSS THE AREA CURRENTLY ARE EXPECTED TO LIFT NORTHEAST OVER THE NEXT FEW HOURS WITH THE FIRST WAVE. SOMEWHAT CONFIDNET OF AT LEAST A FEW HOUR BREAK BEFORE ADDITIONAL SHOWERS/THUNDERSTORMS REDEVELOP SOUTHWEST OF THE TERMINALS AND MOVE NORTHEAST TOWARD DAYBREAK INTO THE MID MORNING HOURS...BUT TIMING IS UNCERTAIN AND UPDATES/CHANGES TO CURRENT TIMING ARE POSSIBLE. ASSUMING THIS SECOND WAVE EXITS THE AREA BY LATE MORNING...EARLY/MID AFTERNOON COULD BE RELATIVELY QUIET WITH STRONG/SEVERE THUNDERSTORMS ALONG/AHEAD OF A COLD FRONT LATE AFTERNOON THRU MID EVENING WITH ONLY LOW/MEDIUM CONFIDENCE REGARDING TIMING. IFR/LIFR CIGS WILL LIKELY CONTINUE THRU DAYBREAK POSSIBLY INTO MID MORNING WHEN WINDS WILL BE SHIFTING SOUTHEAST THEN SOUTHERLY BY LATE MORNING. CIGS WILL LIFT TO AT LEAST MVFR AND MAY BECOME VFR FOR A TIME. IFR/LIFR POSSIBLE WITH THUNDERSTORMS LATER THIS AFTERNOON/EVENING. SOUTHERLY WINDS WILL BEGIN TO INCREASE DURING THE AFTERNOON AND BECOME QUITE STRONG/GUSTY BY LATE AFTERNOON THEN SHIFT MORE WEST/SOUTHWEST BEHIND THE THUNDERSTORMS THIS EVENING. CMS //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM FOR THUNDERSTORM TRENDS/TIMING THRU THE PERIOD. * MEDIUM FOR WINDS THRU THE PERIOD. * LOW/MEDIUM FOR CIGS THRU MID MORNING. CMS //OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z... * FRIDAY...DRY/VFR. GUSTY WEST WINDS. SHC SHRA FRI EVENING. * SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...SLIGHT CHANCE OF SHRA. SOUTH WINDS. * MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. * TUESDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. && .MARINE... 333 PM... AN INCREASING SURFACE PRESSURE GRADIENT IS LEADING TO NNE WINDS OF 15 TO 20 MPH WITH A FEW HIGHER GUSTS THIS AFTERNOON OVER SOUTHERN LAKE MICHIGAN. THERE IS ALSO A FAVORABLE FETCH FOR HIGH WAVES IN THE NEARSHORE ZONES. EXPECT THIS TO PERSIST THROUGH LATE TONIGHT. WESTERLY WINDS IN THE WAKE OF A STRONG LOW PRESSURE SYSTEM WILL BRING GUSTY WINDS TO ALL OF LAKE MICHIGAN THURSDAY NIGHT THROUGH FRIDAY. GALE FORCE GUSTS TO 35 KNOTS OVER THE OPEN WATERS OF SOUTHERN LAKE MICHIGAN ARE POSSIBLE. BREEZY SOUTH WINDS ARE EXPECTED ON SUNDAY AS HIGH PRESSURE SHIFTS EAST OF LAKE MICHIGAN. WIND GUSTS SHOULD REMAIN BELOW GALE FORCE... BUT SMALL CRAFT CONDITIONS MAY BE MET OVER THE NEARSHORE WATERS OF NORTHEAST IL. MRC && .LOT WATCHES/WARNINGS/ADVISORIES... IL...DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL 9 AM THURSDAY. IN...NONE. LM...DENSE FOG ADVISORY...NEARSHORE WATERS UNTIL 10 AM THURSDAY. GALE WATCH...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777- LMZ779...10 PM THURSDAY TO 1 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 303 AM CDT Thu Apr 9 2015 .SHORT TERM...(Today) ISSUED AT 303 AM CDT THU APR 9 2015 Latest surface analysis shows the warm front has lifted to the I-74 corridor early this morning with a chaotic wind field across most of the forecast area. Not sure what the affect the current scattered convection will have on the position of the frontal boundary thru the morning hours, but most of the models suggest a continued slow push to the north as the main surface low tracks northeast to central Iowa by late this morning. Current thinking is that the cold front will be positioned just west of the Mississippi River by 21z with surface based convection developing ahead of the front at that time as well. Better low level helicity fields supportive of discrete supercells and possible tornadoes looks to be closer to the track of the surface low...which by late afternoon is expected to be in far southwest Wisconsin or northwest Illinois. That would put the threat for more persistent low level rotating storms just to our west and north. However, still plenty of shear ahead of the frontal boundary this afternoon and early this evening to promote damaging straight line winds as the storms transition into more of a linear system. Temperature-wise, with the warm front to our north this afternoon, will continue to go with the warmer guid values most areas. Latest model data now suggests the backedge of the precip pushes out of our far southeast counties by midnight, so will extend the Flash Flood Watch until that time this evening. && .LONG TERM...(Tonight through Wednesday) ISSUED AT 303 AM CDT THU APR 9 2015 Showers and thunderstorms, possibly severe, will be ongoing across at least the eastern half of the forecast area to start this evening. Despite the short forecast range, there is still some spread in the expected cold frontal timing. However, it appears reasonable that the front will lie somewhere between the Illinois River and the I-55 corridor by 00Z Friday. Sped up the decrease in shower/storm chances by mid evening, and I would not be surprised to see the precipitation chances taper off a few hours earlier, especially if the squall line gets a head of steam and trends further ahead of the front than current progs. Once the front clears the area tonight, quiet conditions, along with much cooler and less humid air will build across the region into Sunday. These conditions will be driven by a large area of high pressure of Canadian origin. While conditions will be notably cooler/less humid, they will still be at or above normal for early April. The next precipitation chances will arrive later Sunday into Sunday night as a cold front is dragged across the area. While this front is still expected to stall out at it begins to parallel the upper-level flow, model trends suggest the front will stall out further south than previously anticipated. If these trends persist, Monday and Monday night will end up dry. For now, have reduced but not eliminated PoPs Monday/Monday night until we see if this recent model trend sticks. A slow moving upper-level disturbance will push the front back into the area by Tuesday, bringing renewed shower/storm chances. The front and/or upper level disturbances will keep the rain chances going into the end of the work week. Temperatures should remain at or above normal through the period. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) ISSUED AT 1123 PM CDT WED APR 8 2015 A broken line of showers and storms are progressing from SW to NE across our forecast area. Steady rains will clip CMI over the first hour of this TAF period, otherwise the other terminals could see a few hours of dry conditions before showers and storms re- develop directly over central IL. Elevated instability and moisture appear sufficient for a continued storm threat through the night. Localized IFR conditions could develop in any heavy rains, but mainly expect VFR conditions to drop to MVFR periodically overnight due to areas of low clouds as well as precip. The latest HRRR continues to indicate an expansion of coverage of showers and storms across our area tonight, which may linger past sunrise tomorrow before a break develops late morning through mid afternoon. Timing of any storms at the terminal sites is difficult, but will keep at least VCTS during the expected windows of opportunity. Wind patterns have been variable around storms, with prevailing direction from the SE. DEC gusted to 41 MPH at 04z/11pm due to storms. Ambient airflows have seen E-SE winds of 10-15kt, and that should continue the rest of the night based on the position of the frontal boundary. Once the storms depart to the east tomorrow morning, winds will shift to the southwest, and increase to 15-20kt sustained, with gusts to 30kt by afternoon. The next round of strong to severe storms is projected for Thursday afternoon and evening, with damaging winds, hail and even a few tornadoes possible across central IL. && .ILX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH through this evening FOR ILZ054>057-061>063- 066>068-071>073. && $$ SHORT TERM...Smith LONG TERM...Bak AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1252 AM CDT THU APR 9 2015 .UPDATE... IMPROVED NEAR THE LAKESHORE THIS EVENING I AM A BIT HESITANT TO DROP THE ONGOING FOG ADVISORY...AS CONDITIONS COULD FAVOR IT TO REDEVELOP OVERNIGHT. IT STILL APPEARS THAT AS THE WARM FRONT AND HIGH DEW POINT AIR BEGINS TO LIFT NORTHWARD INTO THE COLDER AIR MASS OVER NORTHERN ILLINOIS OVERNIGHT THAT FOG COULD REDEVELOP OVER THE AREA. FOR THIS REASON...I WILL LEAVE THE ADVISORY IN PLACE. IT STILL APPEARS MUCH OF THE AREA WILL BE IN LINE FOR THUNDERSTORM ACTIVITY OVERNIGHT. RADAR IMAGERY IS INDICATING WIDELY SCATTERED CELLS TRYING TO DEVELOP ACROSS EASTERN IOWA AND WESTERN ILLINOIS ASSOCIATED WITH INCREASING WARM ADVECTION. THE 00 UTC SOUNDINGS OUT OF KDVN AND KILX INDICATED THE PRESENCE OF VERY STEEP MID- LEVEL LAPSE RATES ASSOCIATED WITH AN EML. HOWEVER...MOISTURE WAS LACKING A ABOVE THE INVERSION...LIMITING THE ELEVATED CAPE. THIS SEEMS TO BE WHY THE ACTIVITY IS SLOW TO DEVELOP NORTH OF THE WARM FRONTAL BOUNDARY. HOWEVER...WITH A 40+ KT LOW LEVEL JET EXPECTED TO CONTINUE SETTING UP...MOISTURE TRANSPORT SHOULD RESULT IN A RAPID MOISTENING AROUND 850 MB BENEATH THESE STEEP MID LEVEL LAPSE RATES...LIKELY RESULTING IN AN UPTICK IN CONVECTIVE DEVELOPMENT OVER NORTHERN ILLINOIS OVERNIGHT. THE MAIN THREAT WITH THIS ACTIVITY WILL BE SOME HEAVY DOWN POURS AND HAIL. KJB && .SHORT TERM... 322 PM CDT THROUGH THURSDAY NIGHT... QUITE THE CHALLENGING SHORT TERM FORECAST WITH SEVERE WEATHER POSSIBILITIES THROUGHOUT THE TIME AND PROBABLE RAPIDLY SOARING TEMPERATURES FOR THE WHOLE AREA FIRST THING FRIDAY MORNING. THE MAIN TIME FOR POSSIBLE SURFACE-BASED SEVERE WEATHER...INCLUDING WIND AND POSSIBLE TORNADO CONCERNS...CONTINUES TO BE MID-AFTERNOON THROUGH EARLY EVENING ON THURSDAY. THE SURFACE WARM FRONT IS DRAPED ACROSS CENTRAL ILLINOIS AS OF 3 PM...INCLUDING INTO THE FAR SOUTHERN FORECAST AREA. A 1011MB SURFACE LOW REFLECTION IS SEEN IN THE WIND ALONG THIS NEAR DECATUR/CHAMPAIGN...WITH FESTERING NEAR OR SURFACE BASED STORMS JUST AHEAD OF THIS NEAR THE I-74 CORRIDOR OCCASIONALLY PULSING WITH HIGHER CORES. SATELLITE IMAGERY AND RAP ANALYSIS INDICATES THE LIKELY PRESENCE OF VERY SUBTLE MID-LEVEL IMPULSES ACROSS IA/IL/NORTHERN MO...ALL AHEAD OF AN INCREASING UPPER JET NOSING EASTWARD INTO THE OZARK REGION THIS AFTERNOON. IT IS ANTICIPATED THAT THESE PESKY MID-LEVEL FEATURES WILL CONTINUE TO TRAVERSE ACROSS THE AREA THROUGH TONIGHT AND THURSDAY MORNING WITH OVERALL UPPER SUPPORT FOR LIFT GRADUALLY IMPROVING. ONE PROBLEM FOR RAPIDLY INCREASING CONVECTIVE COVERAGE THIS EVENING IS THAT THE STRONGER LOW-LEVEL JET AND MOISTURE TRANSPORT LOOK TO NOT ARRIVE UNTIL LATER INTO THE EVENING AND OVERNIGHT...WHICH SEEMS NECESSARY TO TAP THE ELEVATED MIXED LAYER/VERY STEEP ELEVATED LAPSE RATES FOR MORE WIDESPREAD AND STRONGER CONVECTION. ALSO...STORMS ACROSS THE OZARKS INTO MO AND SW IL MAY LIMIT THE EFFECTIVENESS OF MOISTURE TRANSPORT INTO OUR AREA...AT LEAST AT FIRST THIS EVENING. A FURTHER HINDRANCE TO CONFIDENCE FOR TONIGHT IS THAT CONVECTIVE-ALLOWING MODELS HAVE REALLY STRUGGLED AND DIVERGED WITH HOW TONIGHT WILL PAN OUT FOR STORM COVERAGE. HAVE GONE WITH THE THOUGHT LATER THIS EVENING INTO OVERNIGHT/EARLY THURSDAY MORNING WITH HIGHER LIKELIHOOD FOR STORMS...BUT CERTAINLY CANNOT RULE OUT SCATTERED EVENING ACTIVITY WITHIN THE BROAD WARM ADVECTIVE ZONE. GIVEN THE AFOREMENTIONED LAPSE RATES AND HIGH LEVELS OF CAPE IN THE HAIL GROWTH ZONE...LARGE HAIL WILL CONTINUE TO BE THE MOST PROBABLE THREAT...WITH ANY WIND THREATS REALLY SOUTH OF I-80...IF NOT EVEN SOUTH OF U.S. HIGHWAY 24. AS THE MAIN UPPER TROUGH EJECTS INTO THE CENTRAL PLAINS OVERNIGHT...THE SURFACE RESPONSE SHOULD ALLOW THE WARM FRONT TO CREEP NORTHWARD...AND MAYBE AT A QUICK RATE IF NOT MUCH CONVECTION IS PRESENT. TEMPERATURES WILL THEN WARM AND QUITE QUICKLY WITH THE FRONT PASSAGE...ALLOWING FOR TEMPERATURES TO SOAR INTO THE 70S THURSDAY...EVEN WITH MORNING STORM ACTIVITY. AROUND 80 DEGREES IS POSSIBLE JUST GIVEN OBSERVATION TRENDS TO OUR SOUTH TODAY. THE WARM SECTOR IS LIKELY TO HAVE AT LEAST SOME ELEVATED STORMS THROUGH THE MORNING AND MAYBE EVEN INTO THE AFTERNOON GIVEN THE STEEP LAPSE RATES PRESENT. THIS WILL LIKELY HAVE SOME RESULT ON REGENERATION/RE-INTENSIFICATION OF STORMS...BUT ITS POSSIBLE ANY FESTERING ELEVATED STORMS ARE ABLE TO ROOT LOWER AS THE AFTERNOON PROGRESSES AND BUOYANCY IMPROVES. THE SYNOPTIC PATTERN OF A QUICKLY MOVING CLIMATOLOGICALLY COLD UPPER TROUGH ACROSS A WARM SECTOR CHARACTERIZED BY EARLY APRIL DEW POINTS IN THE 60S CERTAINLY FAVORS ORGANIZED STORM POTENTIAL...INCLUDING SUPERCELLS WITH SIGNIFICANT SEVERE POTENTIAL...AS FURTHER VERIFIED BY SEVERAL OF THE TOP MATCHING CIPS ANALOGS /SIMILAR SCENARIOS/. HOWEVER...SEVERAL ANALOGS SHOW VERY LIMITED SEVERE WEATHER...AS THE PRESENT INGREDIENTS JUST DID NOT LINE UP PERFECTLY AS CAN OFTEN BE THE CASE IN MODERATE/STRONG DYNAMIC SITUATIONS. SO CONFIDENCE REMAINS MINIMAL ON COVERAGE OF HIGHER INTENSITY STORMS...BUT AT THIS JUNCTURE WOULD BE SURPRISED TO NOT HAVE AT LEAST AN UPTICK IN LOWER ROOTED STORMS DURING THE MID-AFTERNOON THROUGH EARLY EVENING PERIOD MOVING FROM WEST TO EAST ACROSS THE AREA. WHILE THE NORTHERN CWA MAY HAVE MORE BACKED LOW-LEVEL FLOW...THE ENTIRE AREA WILL BE UNDER A STRONG SSW 50-55 KT LOW- LEVEL JET WHICH WOULD KEEP SOME THREATS OF SURFACE BASED CONVECTION THROUGH THE EVENING AHEAD OF THE FRONT. HAIL WILL REMAIN THE GREATEST CONCERN...ESPECIALLY WITH THE AFTERNOON ACTIVITY...BUT SOME ORGANIZED STRONG WINDS OR TORNADOES IN THE REGION ARE POSSIBLE DEPENDING ON STORM MODE/COVERAGE. STORMS SHOULD BE EAST OF THE AREA BY 9 PM-12 AM THURSDAY EVENING WITH COOLER AND DRIER AIR WRAPPING IN ON GUSTY WESTERLY WINDS. MTF && .LONG TERM... FRIDAY THROUGH SATURDAY... FORECAST CONFIDENCE HIGH. A POTENT SHORTWAVE WILL ROLL THROUGH SOUTHERN WI ON FRIDAY. THE CYCLONIC FLOW AND STEEP LOW LEVEL LAPSE RATES WILL LEAD TO PLENTY OF DIURNAL CUMULUS CLOUDS. A FEW SHOWERS ARE POSSIBLE TOWARD NORTHEAST IL CLOSER TO THE VORTICITY MAXIMUM. SURFACE HIGH PRESSURE WILL SPREAD INTO THE MIDWEST FRIDAY NIGHT THROUGH SATURDAY AND BRING QUIET WEATHER. CLEAR SKIES FRIDAY NIGHT WILL ALLOW TEMPS TO DROP INTO THE LOWER TO MID 30S... COLDEST NEAR THE WI BORDER. TEMPERATURES SHOULD REBOUND INTO THE LOWER 60S SATURDAY WITH WEAK WARM AIR ADVECTION OVER THE AREA. SUNDAY... FORECAST CONFIDENCE HIGH. SOUTHERLY WINDS WILL INCREASE AHEAD OF A MID LEVEL SHORTWAVE AND AN ASSOCIATED SURFACE LOW PRESSURE TROUGH SWINGING THROUGH THE UPPER MIDWEST AND GREAT LAKES REGION. LOW LEVELS ARE EXPECTED TO BE DRY... SO NO PRECIP IS ANTICIPATED ACROSS NORTHEAST IL DURING THE DAY. LIGHT SHOWERS WILL BE POSSIBLE SUNDAY NIGHT AS THE SURFACE TROUGH PASSES THROUGH THE AREA. MODELS SOUNDINGS SHOW MINIMAL INSTABILITY SO I LEFT OUT THUNDER. MONDAY THROUGH TUESDAY... FORECAST CONFIDENCE MEDIUM. MODELS ARE SLOWING DOWN THE SPEED OF THE WARM FRONTAL PRECIP INTO CENTRAL IL ON MONDAY. THUS... CHANCES FOR SHOWERS AND THUNDERSTORMS ARE DECREASING. BY MONDAY NIGHT... THE WARM FRONT WILL MAKE IT INTO EITHER NORTHERN IL OR SOUTHERN WI. THIS WILL ALLOW FOR A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA THROUGH TUESDAY NIGHT. THERE IS A POSSIBILITY FOR SEVERE WITH THIS SYSTEM AND IT WILL NEED TO BE WATCHED. MRC && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * SCATTERED THUNDERSTORMS THRU MID MORNING. * STRONG/SEVERE THUNDERSTORMS LATE AFTERNOON/EARLY EVENING. * IFR/LIFR THRU MID MORNING. * EAST WINDS BECOMING SOUTHEAST THIS MORNING...THEN STRONG/GUSTY SOUTHWEST THIS AFTERNOON. CMS //DISCUSSION...UPDATED 06Z... SHOWERS/THUNDERSTORMS ACROSS THE AREA CURRENTLY ARE EXPECTED TO LIFT NORTHEAST OVER THE NEXT FEW HOURS WITH THE FIRST WAVE. SOMEWHAT CONFIDNET OF AT LEAST A FEW HOUR BREAK BEFORE ADDITIONAL SHOWERS/THUNDERSTORMS REDEVELOP SOUTHWEST OF THE TERMINALS AND MOVE NORTHEAST TOWARD DAYBREAK INTO THE MID MORNING HOURS...BUT TIMING IS UNCERTAIN AND UPDATES/CHANGES TO CURRENT TIMING ARE POSSIBLE. ASSUMING THIS SECOND WAVE EXITS THE AREA BY LATE MORNING...EARLY/MID AFTERNOON COULD BE RELATIVELY QUIET WITH STRONG/SEVERE THUNDERSTORMS ALONG/AHEAD OF A COLD FRONT LATE AFTERNOON THRU MID EVENING WITH ONLY LOW/MEDIUM CONFIDENCE REGARDING TIMING. IFR/LIFR CIGS WILL LIKELY CONTINUE THRU DAYBREAK POSSIBLY INTO MID MORNING WHEN WINDS WILL BE SHIFTING SOUTHEAST THEN SOUTHERLY BY LATE MORNING. CIGS WILL LIFT TO AT LEAST MVFR AND MAY BECOME VFR FOR A TIME. IFR/LIFR POSSIBLE WITH THUNDERSTORMS LATER THIS AFTERNOON/EVENING. SOUTHERLY WINDS WILL BEGIN TO INCREASE DURING THE AFTERNOON AND BECOME QUITE STRONG/GUSTY BY LATE AFTERNOON THEN SHIFT MORE WEST/SOUTHWEST BEHIND THE THUNDERSTORMS THIS EVENING. CMS //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM FOR THUNDERSTORM TRENDS/TIMING THRU THE PERIOD. * MEDIUM FOR WINDS THRU THE PERIOD. * LOW/MEDIUM FOR CIGS THRU MID MORNING. CMS //OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z... * FRIDAY...DRY/VFR. GUSTY WEST WINDS. SHC SHRA FRI EVENING. * SATURDAY...DRY/VFR. SOUTH WINDS. LAKE BREEZE POSSIBLE. * SUNDAY...SLIGHT CHANCE OF SHRA. SOUTH WINDS. * MONDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. * TUESDAY...CHANCE OF SHRA/TSRA. SOUTHWEST WINDS. && .MARINE... 333 PM... AN INCREASING SURFACE PRESSURE GRADIENT IS LEADING TO NNE WINDS OF 15 TO 20 MPH WITH A FEW HIGHER GUSTS THIS AFTERNOON OVER SOUTHERN LAKE MICHIGAN. THERE IS ALSO A FAVORABLE FETCH FOR HIGH WAVES IN THE NEARSHORE ZONES. EXPECT THIS TO PERSIST THROUGH LATE TONIGHT. WESTERLY WINDS IN THE WAKE OF A STRONG LOW PRESSURE SYSTEM WILL BRING GUSTY WINDS TO ALL OF LAKE MICHIGAN THURSDAY NIGHT THROUGH FRIDAY. GALE FORCE GUSTS TO 35 KNOTS OVER THE OPEN WATERS OF SOUTHERN LAKE MICHIGAN ARE POSSIBLE. BREEZY SOUTH WINDS ARE EXPECTED ON SUNDAY AS HIGH PRESSURE SHIFTS EAST OF LAKE MICHIGAN. WIND GUSTS SHOULD REMAIN BELOW GALE FORCE... BUT SMALL CRAFT CONDITIONS MAY BE MET OVER THE NEARSHORE WATERS OF NORTHEAST IL. MRC && .LOT WATCHES/WARNINGS/ADVISORIES... IL...DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL 9 AM THURSDAY. IN...NONE. LM...DENSE FOG ADVISORY...NEARSHORE WATERS UNTIL 10 AM THURSDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
708 PM EDT FRI APR 10 2015 .SYNOPSIS... ISSUED AT 1115 AM EDT FRI APR 10 2015 HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT RESULTING IN DIMINISHING WINDS. FAIR WEATHER WILL THEN CONTINUE SATURDAY AS THE HIGH MOVES ACROSS THE AREA. LOWS TONIGHT WILL BE IN THE MID 30S WITH HIGHS SATURDAY IN THE UPPER 50S AND LOWER 60S. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 357 PM EDT FRI APR 10 2015 987MB SURFACE LOW LIFTING INTO QUEBEC AT PRESS TIME WITH A SECONDARY VORT MAX AND SURFACE PRESSURE TROUGH CURRENTLY ROTATING THROUGH CHICAGO. BRIEF RELAXATION OF PRESSURE GRADIENT AHEAD OF THIS BOUNDARY HAS ALLOWED WIND SPEEDS TO SUBSIDE A BIT THIS AFTERNOON. HOWEVER...UPSTREAM SURFACE OBS SHOW NUMEROUS GUSTS OVER 40 KTS ALONG AND IMMEDIATELY BEHIND THE FRONT. RAP FORECAST SOUNDINGS INDICATE VERY DEEP MIXING HEIGHTS IN PLACE OVER OUR AREA LATE THIS AFTERNOON WITH 50 KT WINDS AT THE TOP OF THE BOUNDARY LAYER AND A GOOD PUSH OF ISENTROPIC DESCENT SEEN MOVING IN BEHIND THE SURFACE BOUNDARY. MSAS ANALYSIS ALSO SHOWS A DECENT PRESSURE RISE-FALL COUPLET ALONG THIS BOUNDARY THAT MAY BE HELPING PRODUCE THE HIGHER WIND GUSTS. WE DO START TO LOSE DIURNAL SURFACE HEATING/BETTER PBL MIXING BY THE TIME THIS TROUGH MAKES IT TO OUR AREA BUT AM CONCERNED WE COULD SEE A FEW GUSTS TO WIND ADVISORY CRITERIA...ESPECIALLY IN OUR SOUTHWEST ZONES...DURING THE EARLY EVENING AND AM HESITANT TO SOUND THE "ALL CLEAR" ON STRONG WIND GUSTS. HAVE THEREFORE DECIDED TO EXTEND AND EXPAND THE WIND ADVISORY CURRENTLY IN PLACE. THIS SECONDARY PV ANOMALY...EXTENDING DEEP INTO THE TROPOSPHERE...MAY ALSO GENERATE SOME SHOWERS AS IT ROTATES THROUGH THE REGION THIS EVENING. UPSTREAM RADAR/SURFACE OBS SHOW DECENT SHOWERS...AND EVEN A FEW THUNDERSTORMS...OCCURRING WITH THIS WAVE AND SUSPECT SIMILAR RESULTS IN OUR LOCAL AREA. MOST OF THE LATEST HI-RES/RAPID UPDATE MODELS GENERATE AT LEAST SOME QPF IN OUR NORTHERN CWA AND SEE NO REASON TO ARGUE BASED ON STRENGTH/DEPTH OF THE ANOMALY SEEN IN BOTH WV IMAGERY AND MODEL PLAN VIEWS. HAVE THEREFORE RAISED POPS FOR OUR NORTHERN ZONES IN THE 22-03Z TIMEFRAME. IT IS POSSIBLE THAT THESE SHOWERS COULD HELP MIX DOWN SOME STRONGER WIND GUSTS IN THE 40-50 MPH RANGE THIS EVENING....PROVIDING FURTHER SUPPORT FOR A SIMPLE EXTENSION OF THE CURRENT WIND ADVISORY. OVERNIGHT LOWS SHOULD EASILY DROP INTO THE MID 30S UNDER STRONG CAA. STAYED PRETTY CLOSE TO INHERITED FORECAST...WHICH WAS SIMILAR TO LATEST MOS GUIDANCE. WELCOME RETURN TO MORE TRANQUIL WEATHER BY TOMORROW AS MID/UPPER LEVEL RIDGING AND SURFACE ANTICYCLONE BUILD DIRECTLY OVERHEAD. SOME LATE DAY WAA AND FULL SUN SHOULD PUSH US TO AROUND 60F DESPITE COOL START. && .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 357 PM EDT FRI APR 10 2015 LONG TERM FORECAST STARTS OUT QUIET...WITH AN AMPLIFYING 500MB RIDGE ALOFT AND SFC HIGH PRESSURE CENTERED OVER THE OHIO VALLEY SATURDAY NIGHT. SKIES WILL START OUT CLEAR IN THE EVENING...THEN BECOME PARTLY CLOUDY WEST AND CENTRAL AS A LOW PRESSURE TROUGH APPROACHES FROM THE WEST. LOWS WILL BE ON THE COOL SIDE BUT NEAR NORMAL FOR THIS TIME OF YEAR...ESPECIALLY IN THE NORTHEAST GIVEN CLEAR SKIES AND LIGHT WINDS. KEPT GOING FORECAST OF TEMPS IN THE MID-UPPER 30S. CHANCES FOR PRECIPITATION AND FORECAST COMPLEXITY RETURN LATE WEEKEND AND CONTINUE THROUGH THE WORK WEEK...WITH A COMPLICATED PATTERN AND THE ASSOCIATED MODEL DISAGREEMENT. SUNDAY AFTERNOON-EVENING THE CWA SITS ON THE OUTER EDGE OF THE SFC HIGH PRESSURE SYSTEM...WHICH BY THIS TIME IS JUST OFF THE EASTERN US COAST. AT THE UPPER LEVELS...THE RIDGE OVER THE GREAT LAKES REGION BEGINS TO BREAK DOWN AS VARIOUS SHORTWAVES PROPAGATE THROUGH THE FLOW FROM THE DEEPENING TROUGH MOVING THROUGH THE NORTHERN PLAINS. A SURFACE LOW PRESSURE SYSTEM IS LOCATED OVER MANITOBA. BY LATE SUNDAY AFTERNOON/EVENING THE SURFACE LOW PRESSURE TROUGH/COLD FRONT EXTENDS FROM MN/WI SOUTHWESTWARD TO THE CENTRAL PLAINS. GENERAL DISAGREEMENT AMONG MODELS ON EXACT TIMING OF ANY PRECIPITATION...WITH THE GFS BEING MOST PROGRESSIVE AND DEVELOPING PRECIPITATION AHEAD OF THE COLD FRONT SUNDAY AFTERNOON IN OUR CWA...AND THE NAM/GEM ECMWF WAITING UNTIL SUNDAY NIGHT/MONDAY MORNING TO BRING IN PRECIPITATION. THE ECMWF CAMP IS ALSO A BIT SHARPER WITH THE UL TROUGH...WHEREAS THE GFS IS MORE BROAD. DECIDED TO GO WITH A GFS/ECMWF COMPROMISE FOR NOW WITH RESPECT TO TIMING OF POPS. THIS BRINGS THE FRONT THROUGH SUNDAY EVENING AND HAS IT EXITING THE EASTERN CWA BY MONDAY AFTERNOON...AND HAVE POPS/WINDS REFLECTING THIS. MOISTURE WILL BE AMPLE AHEAD OF THE FRONT...AS PWATS INCREASE TO AROUND 1.3 INCHES WITH RETURN FLOW AROUND THE SFC HIGH AND APPROACHING LOW PRESSURE TROUGH TO WEST...PULLING MOISTURE RIGHT FROM THE GULF OF MEXICO. FRONT MOVEMENT SHOULD BE PRETTY QUICK...AND INSTABILITY IS MINIMAL SO DONT REALLY HAVE ANY CONCERNS FOR STORMS WITH THIS. DID ADD A SLGHT CHANCE FOR THUNDER LATE SUN NIGHT WITH SOME MODELS GENERATING 100-200 J/KG OF MUCAPE...BUT NOT REALLY CONFIDENT IN THAT OCCURRING. SURFACE HIGH PRESSURE QUICKLY MOVES IN UNDERNEATH A BUILDING UPPER LEVEL RIDGE MONDAY NIGHT INTO TUESDAY AND TUESDAY NIGHT...WHICH MODELS APPEAR TO AGREE ON. AS A RESULT...KEPT THINGS DRY FOR THAT TIME. HOWEVER...BY MID TO LATE WEEK...PROBLEMS DEVELOP AS THEY ATTEMPT TO RESOLVE SPLIT FLOW ALOFT...WITH A TROUGH LIFTING FROM THE SOUTHWESTERN U.S. INTO THE CENTRAL PLAINS 00Z WED...AND ANOTHER TROUGH/POTENTIAL CLOSED LOW MOVING EASTWARD INTO THE CANADIAN PRAIRIE THROUGH THURSDAY. BOTH THE GFS/ECMWF DEVELOP A SURFACE/UPPER LEVEL TROUGH THAT EXTENDS FROM THE DAKOTAS SOUTHEASTWARD ACROSS OUR CWA...AND INTO KY/TN. THIS BRINGS US SLIGHT CHANCES FOR PRECIPITATION WEDNESDAY...AND HIGHER POPS INTO THURSDAY/FRIDAY AS THE PATTERN SOLIDIFIES INTO A CUT-OFF LOW OVER THE MIDWEST. THE LOW EVENTUALLY DRIFTS ACROSS THE GREAT LAKES REGION...BUT AS TO STRENGTH/TIMING/EXACTLY HOW FAR SOUTH THE LOW MOVES....ITS ALL UP IN THE AIR. KEPT CONSENSUS CHANCE POPS IN FOR THIS TIME PERIOD...WITH CHANCE THUNDER ONLY ON THURSDAY WHEN BOTH MODELS HAVE US IN THE WARM SECTOR OF THE OCCLUDED SFC LOW. CONFIDENCE IN THIS FORECAST IS LOWER...GIVEN MODEL DISCREPANCIES AND DIFFICULTIES HANDLING THE MERGING FEATURES. AS FAR AS TEMPERATURES GO...LOOKS TO STAY NEAR NORMAL FOR THE MOST PART...WITH HIGHS IN THE 60S/UPPER 50S NEAR THE LAKE/ AND LOWS IN THE UPPER 30S AND 40S. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 702 PM EDT FRI APR 10 2015 WINDS SHOULD GRDLY DIMINISH THIS EVE WITH LOSS OF HEATING/MIXING. SOME MVFR CIGS ASSOCIATED WITH SECONDARY CDFNT ACROSS SRN WI/MI BUT A LITTLE DRIER LOW LEVELS OVER NRN IL/IN SHOULD KEEP CIGS VFR IN OUR AREA OVERNIGHT. WITH COLD AIR ALOFT LINGERING OVER THE AREA SATURDAY EXPECT SCT-BKN VFR CU ONCE AGAIN BUT WINDS SHOULD BE CONSIDERABLY LIGHTER AS HIGH PRESSURE RIDGE BUILDS INTO THE AREA. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...WIND ADVISORY UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR INZ003>009-012>018-020-022>027-032>034. MI...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ077>081. OH...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ001-002-004-005- 015-016-024-025. LM...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LMZ043-046. && $$ SYNOPSIS...LOTHAMER SHORT TERM...AGD LONG TERM...MCD AVIATION...JT VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION...CORRECTED
NWS NORTHERN INDIANA
325 PM EDT THU APR 9 2015 .SYNOPSIS... ISSUED AT 1120 AM EDT THU APR 9 2015 A LOW PRESSURE CENTER IS CURRENTLY LOCATED OVER SOUTHERN IOWA AND NORTHERN MISSOURI. THIS LOW IS MOVING A WARM FRONT AND SOME SHOWERS AND THUNDERSTORMS THROUGH THE REGION TODAY AND WILL MOVE A COLD FRONT AND SOME MORE SHOWERS AND THUNDERSTORMS THROUGH TONIGHT. SOME OF THESE STORMS THIS AFTERNOON AND THIS EVENING COULD BECOME STRONG TO SEVERE. HIGH TEMPERATURES TODAY WILL RANGE FROM THE LOWER 70S IN SOUTHERN MICHIGAN TO THE MIDDLE 70S ALONG THE OHIO RIVER. LOW TEMPERATURES TONIGHT WILL RANGE FROM THE MIDDLE 40S IN SOUTHERN MICHIGAN TO AROUND 50 NEAR THE OHIO RIVER. && .SHORT TERM...(THIS EVENING AND TONIGHT) ISSUED AT 324 PM EDT THU APR 9 2015 MULTIPLE CONVECTIVELY-ENHANCED SHORTWAVES CONTINUE TO RIPPLE THROUGH THE REGION IN SOUTHWEST FLOW AHEAD OF MAIN TROUGH AXIS STILL WELL TO OUR WEST. THIS HAS LED TO A MUDDLED MESOSCALE ENVIRONMENT WITH MULTIPLE ROUNDS OF WEAK/ELEVATED CONVECTION SO FAR TODAY. DIURNAL DESTABILIZATION HAS BEEN SLOW GIVEN ABUNDANT RAIN AND STRATUS. STARTED TO SEE SOME BREAKS IN THE CLOUDS DURING THE LAST COUPLE HOURS BUT STILL A LOT OF CONVECTIVE DEBRIS TO INHIBIT SURFACE DIABATIC HEATING. LATEST RAP/SPC MESOANALYSIS SHOWS BETTER SURFACE BASED INSTABILITY JUST NOW STARTING TO NOSE INTO OUR SOUTHWESTERN CWA AS WARM FRONT IS PUSHED NORTHWARD BY STRENGTHENING LOW LEVEL GRADIENT AHEAD OF APPROACHING LOW BUT RAP SOUNDINGS STILL SHOW A SUBTLE 700-800MB INVERSION OVER MUCH OF OUR AREA THROUGH THE LATE AFTERNOON. TWO FEATURES TO WATCH FOR SEVERE WEATHER THREAT THIS EVENING...ONE IS A SUBTLE PREFRONTAL TROUGH CURRENTLY PUSHING THROUGH NORTH-CENTRAL ILLINOIS AND SECOND IS THE ACTUAL COLD FRONT ITSELF...STILL IN CENTRAL MISSOURI. FORCING IS WEAK WITH THE FIRST WAVE BUT APPEARS TO BE ENOUGH SURFACE HEATING TO GENERATE AROUND 1000 J/KG OF MLCAPE OVER ILLINOIS. THERE IS HOWEVER A LOCAL MINIMUM OF INSTABILITY SEEN ON RAP/SPC MESOANALYSIS OVER WESTERN INDIANA. RAP SUGGESTS INSTABILITY IN THIS AREA WILL FILL IN OVER THE NEXT FEW HOURS AND IF THE CLUSTER OF STORMS OVER CENTRAL ILLINOIS CAN LATCH ONTO THAT...IT WILL BE CAPABLE OF PRODUCING SEVERE WEATHER IN OUR AREA LATER THIS AFTERNOON. CONFIDENCE IN THIS HAPPENING IS LOW THOUGH...GIVEN NORTHWARD DISPLACEMENT OF STORMS CURRENTLY ON RADAR AND RELATIVELY DIFFUSE FORCING. STORMS MAY CLIP OUR NORTHWEST COUNTIES BUT DIFFICULT TO SAY HOW MUCH INSTABILITY WILL BE LEFT BY THAT POINT. SPC HAS ISSUED A TORNADO WATCH RIGHT UP TO OUR WESTERN BORDER. WILL CONTINUE TO MONITOR CLUSTER OF STORMS UPSTREAM DURING THE NEXT FEW HOURS TO SEE IF A LOCAL EXTENSION MAY BE NECESSARY BUT FOR NOW THREAT APPEARS LOW. POTENTIAL THREAT WITH THIS FEATURE WILL FALL IN THE 22-00Z TIMEFRAME WITH THE MAIN HAZARD BEING DAMAGING WINDS. SECOND FEATURE TO WATCH IS THE ACTUAL COLD FRONT. THIS FEATURE WILL NOT ARRIVE UNTIL 03-04Z TONIGHT AND BY THEN WE LOSE ANY SURFACE BASED INSTABILITY. MIDLEVEL LAPSE RATES ARE MODEST...AROUND 7 C/KM...BUT NOT QUITE HIGH ENOUGH TO SUPPORT A WIDESPREAD SEVERE WEATHER THREAT. SOME DAMAGING WINDS ARE CERTAINLY POSSIBLE GIVEN VERY STRONG LLJ WITH 850MB WINDS OVER 50 KTS BUT WILL BE CONTINGENT UPON GETTING A SUSTAINED UPDRAFT AND ADEQUATE PRECIP LOADING. THAT IS QUESTIONABLE AT THIS POINT. THREAT IS CERTAINLY THERE BUT IS CONDITIONAL ON HOW MUCH INSTABILITY IS LEFT BY THE TIME IT REACHES US. WILL CONTINUE TO MONITOR UPSTREAM TRENDS CLOSELY THROUGH THE LATE AFTERNOON AND EVENING TO UPDATE THE FORECAST AS NECESSARY. UPDATED GRIDS/ZFP WILL BE OUT SHORTLY. && .LONG TERM...(FRIDAY THROUGH THURSDAY) ISSUED AT 324 PM EDT THU APR 9 2015 PRIMARY FOCUS FOR THE LONG TERM WILL BE HIGH WINDS ON FRIDAY... THE SFC LOW PRESSURE SYSTEM RESPONSIBLE FOR THE ACTIVE WEATHER TODAY WILL HAVE MADE ITS WAY INTO EASTERN UPPER MICHIGAN BY FRIDAY MORNING. THIS PUTS THE CWA LARGELY IN THE DRY SLOT AND IN THE REGION OF CAA. ALOFT...A CLOSED 500MB LOW LIFTS FROM UPPER MICHIGAN FRIDAY MORNING TO JUST SOUTH OF JAMES BAY BY FRIDAY NIGHT. WITH A STRONG RIDGE ANCHORED OVER THE ATLANTIC/NEW ENGLAND STATES...A 100 KT 500MB JET DEVELOPS OVER THE CWA AND REMAINS THROUGH AT LEAST THE EARLY AFTERNOON. LOOKING AT MODEL SOUNDINGS...IT APPEARS WE WILL BE MIXING TO NEAR 900MB EARLIER IN THE DAY...THEN UP AS HIGH AS 700-750MB BY MID AFTERNOON. THINKING GUSTS WILL BE HIGHEST IN THE EARLY AFTERNOON THEN TAPER OFF WEST TO EAST AS THE UPPER LEVEL WIND MAXIMUM AND SFC PRESSURE RISE/FALL COUPLET MOVES NORTHEASTWARD. THINKING GUSTS TO 35-45 MPH ARE LIKELY GIVEN MIXING POTENTIAL TOMORROW...BUT WILL HOLD OFF ON ISSUING ANY WIND ADVISORIES FOR NOW...AS WE ARE RIGHT BELOW CRITERIA AND DO NOT WANT TO DETRACT PUBLIC ATTENTION AWAY FROM THE THREAT OF SEVERE WEATHER THIS EVENING/OVERNIGHT. KEPT THE GOING HEADLINE FOR THE GALE WARNING UNTIL 15Z...AS CONDITIONS ARE MORE STABLE OVER THE LAKE. OTHERWISE...SHORTWAVE/PV ANOMALY ROTATING AROUND THE EXITING LOW PRESSURE MAY BRING ADDITIONAL LL MOISTURE FORCING FOR RAIN SHOWERS FRIDAY AFTERNOON/EVENING...MAINLY IN THE NORTHERN PORTIONS OF OUR CWA. MODELS WERE IN GREAT DISAGREEMENT AS TO THE STRENGTH OF THE WAVE...SO FOR NOW KEPT JUST SLIGHT CHANCE POPS/RAIN SHOWERS FOR NOW. HIGHS WILL RANGE FROM THE MID-UPPER 50S TO LOW 60S. SATURDAY INTO SUNDAY AFTERNOON WILL BE RELATIVELY QUIET...WITH HIGH PRESSURE SETTLING IN OVERHEAD. HIGH TEMPERATURES WILL BE COOL...WITH HIGHS AGAIN STRUGGLING TO REACH ABOVE THE LOW 60S. FOR THE EXTENDED PERIOD...500MB FLOW IS SOMEWHAT SPLIT BY SUNDAY NIGHT...WITH A DEEPENING TROUGH MOVING ACROSS NORTHERN ONTARIO AND UPPER MI/NORTHERN LOWER MI THROUGH MONDAY NIGHT...THEN A DEVELOPING CLOSED LOW IN THE SOUTHWESTERN U.S. TAKES SHAPE MONDAY NIGHT INTO TUE AS A RIDGE BUILDS OVER OUR CWA AND THE SOUTHEASTERN STATES. THE LOW DEEPENS AND MOVES NORTHEASTWARD TUE NIGHT INTO THE NORTH-CENTRAL PLAINS BEFORE PHASING INTO THE NORTHERN BRANCH WED. FOR OUR CWA...MODELS ARE IN GENERAL AGREEMENT WITH RESPECT TO THE COLD FRONT ASSOCIATED WITH THE NORTHERN STREAM SYSTEM IN ONTARIO/UPPER MI. BOTH THE ECMWF/GFS BRING THE FRONT ACROSS OUR AREA SUNDAY NIGHT INTO MONDAY...THOUGH THEY DIFFER WITH RESPECT TO EXACT TIMING AND STRENGTH. AS USUAL...THE GFS IS FASTER AND SLIGHTLY DEEPER WITH THE UPPER LEVEL TROUGH MOVING THROUGH...AND THUS THE FRONT IS MORE ORGANIZED. THE ECMWF SHOWS A WEAKER UL TROUGH AND CORRESPONDING SFC SYSTEM/COLD FRONT. KEPT CONSENSUS POPS FOR NOW...WHICH DID A DECENT JOB SHOWING THE OVERALL TREND. TUESDAY LOOKS TO REMAIN LARGELY QUIET...WITH SMALL RIDGE BUILDING OVER THE AREA FOR THE FIRST PART OF THE DAY. SLIGHT CHANCE FOR RAIN SHOWERS BY LATE AFTERNOON WITH NEXT APPROACHING SYSTEM. OF COURSE...THE PHASING SYSTEMS/STREAMS ARE A COMPLETE MESS IN THE MODEL WORLD...WITH A WHOLE HOST OF SOLUTIONS THAT COULD PLAY OUT TUESDAY NIGHT INTO THURSDAY. JUST KEPT THE CONSENSUS POPS AND OUR FORECASTED THUNDER AS THERE IS TOO MUCH DISAGREEMENT TO MAKE ANY REAL IMPROVEMENTS. GOOD NEWS IS...TEMPS WARM INTO THE UPPER 60S AND LOW 70S FOR MUCH OF THIS TIME PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 134 PM EDT THU APR 9 2015 SEVERAL WAVES OF CONVECTION CONTINUE TO PUSH THROUGH THE AREA IN MOIST SOUTHWEST FLOW AHEAD OF THE MAIN TROUGH STILL WELL TO OUR WEST. ONE CLUSTER IS CURRENTLY EXITING THE KFWA AREA AND ANOTHER IS SET TO CLIP KSBN WITHIN THE HOUR. BRIEF REDUCTIONS TO MVFR CATEGORY ARE EXPECTED WITH THESE SHOWERS AND THUNDERSTORMS...ALONG WITH WIND GUSTS TO AROUND 30 KTS. SHOULD SEE A BRIEF LULL IN ACTIVITY DURING MID TO LATE AFTERNOON BEFORE ANOTHER ROUND OF CONVECTION ARRIVES AHEAD OF THE MAIN COLD FRONT. STILL SOME UNCERTAINTY AS TO EXACT TIMING OF THUNDER. ALL PRECIP SHOULD EXIT SHORTLY AFTER 06Z TONIGHT BUT STRONG CAA WILL SUPPORT SOME MVFR STRATUS THROUGH AT LEAST THE EARLY MORNING. STRONG WINDS WILL BE THE OTHER MAIN STORY WITH GUSTS TO 35 KTS POSSIBLE LATE TONIGHT INTO TOMORROW WITH DEEP MIXING AND A STRONG GRADIENT. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...GALE WARNING FROM 11 PM THIS EVENING TO 11 AM EDT FRIDAY FOR LMZ043-046. && $$ SYNOPSIS...LOTHAMER SHORT TERM...AGD LONG TERM...MCD AVIATION...AGD VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
152 AM EDT THU APR 9 2015 .SYNOPSIS... ISSUED AT 1003 AM EDT WED APR 8 2015 SEVERAL PERIODS OF RAIN WILL BE POSSIBLE DURING THE NEXT COUPLE OF DAYS. A STATIONARY FRONT OVER CENTRAL PORTIONS OF INDIANA AND OHIO IS EXPECTED TO LIFT SLOWLY NORTH INTO MICHIGAN TONIGHT. SCATTERED THUNDERSTORMS ARE POSSIBLE NEAR THE FRONT TODAY WITH SHOWERS AND THUNDERSTORMS LIKELY BECOMING NUMEROUS TONIGHT. A COLD FRONT WILL APPROACH THE AREA ON THURSDAY LIKELY CAUSING ANOTHER ROUND OF THUNDERSTORMS. HIGHS TODAY ARE EXPECTED TO RANGE FROM THE MID 50S NORTH OF THE FRONT IN SOUTHERN MICHIGAN TO THE LOW 70S SOUTH OF THE FRONT SOUTH OF US 30. LOWS TONIGHT WILL BE IN THE 50S. && .SHORT TERM...(THIS EVENING AND TONIGHT) ISSUED AT 400 PM EDT WED APR 8 2015 BRIEF LULL IN PRECIP AND INCREASED LOW LEVEL MIXING IS CURRENTLY IN PLACE ACROSS NORTHERN INDIANA THANKS TO MIDLEVEL SHORTWAVE RIDGING/AVA IN THE WAKE OF THIS MORNING`S CONVECTION. MCS THAT MOVED THROUGH CENTRAL INDIANA EARLIER TODAY SEEMS TO HAVE LEFT MOST OF OUR AREA FAIRLY STABLE/CAPPED PER LATEST SPC/RAP MESOANALYSIS. FORECAST SOUNDINGS SHOW A DECENT INVERSION AROUND 800MB...EVEN IN AREAS THAT HAVE MANAGED TO MIX OUT. NAM12 TRIES TO WEAKEN THIS CAPPING INVERSION IN OUR AREA LATER THIS AFTERNOON BUT RAP AND GFS KEEP IT IN PLACE FOR MUCH OF THE EVENING...AT LEAST OUTSIDE OF THE FAR SOUTH. BASED ON THE LATEST RADAR...SATELLITE...AND SURFACE OBSERVATIONAL TRENDS...PREFER TO LEAN TOWARD THE RAP IDEA OF KEEPING OUR CWA MAINLY CAPPED WITH CONVECTION TIED TO BETTER INSTABILITY JUST TO OUR SOUTH. SYNOPTIC FORCING IS PRETTY MUDDLED AT THIS POINT BUT THERE ARE SOME HINTS OF MODEST 300K ISENTROPIC ASCENT JUST TO OUR SOUTH AS WELL. SPC HAS ISSUED A SEVERE THUNDERSTORM WATCH UP TO OUR SOUTHWEST BORDER AND THIS SEEMS REASONABLE. CURRENTLY WATCHING A CLUSTER OF STORMS OVER EASTERN ILLINOIS THAT COULD SCRAPE OUR FAR SOUTHERN COUNTIES. IF THIS ACTIVITY DOES CLIP OUR AREA...IT COULD VERY WELL PRODUCE SEVERE WEATHER GIVEN DEEP LAYER SHEAR OVER 40 KTS AND MLCAPE VALUES OVER 2000 J/KG DUE TO MIDLEVEL LAPSE RATES AROUND 8 C/KM. BETTER CHANCES FOR MORE WIDESPREAD RAIN AND THUNDERSTORMS EXPECTED LATE OVERNIGHT. ANOTHER WEAK/EMBEDDED SHORTWAVE WILL EJECT NORTHEAST ALONG WITH NOCTURNAL STRENGTHENING OF THE LOW LEVEL JET. ANOTHER ROUND OF INCREASED MOISTURE FLUX CONVERGENCE AND ISENTROPIC ASCENT IN A REGION OF MODERATE ELEVATED INSTABILITY MAY SUPPORT EXPANDING CONVECTION LATE TONIGHT. EXACT TIMING AND LOCATION IS DIFFICULT TO PINPOINT AT THIS STAGE WITH A VARIETY OF SOLUTIONS BEING OFFERED BY LATEST HI-RES GUIDANCE. AM A LITTLE UNEASY WITH INHERITED CATEGORICAL POPS GIVEN DRY SOLUTIONS BEING OFFERED BY SOME HI-RES GUIDANCE SUCH AS THE 4KM SPC WRF-NMM. LOWERED POPS EARLIER IN THE PERIOD BUT DID KEEP SOME CATEGORICAL POPS IN THE 09-12Z PERIOD OUT OF RESPECT FOR THE INCREASING WARM/MOIST AIR ADVECTION AND MODEL DEPICTIONS OF WEAK CVA FORCING. OTHER ASPECT THAT DEMANDS SOME ATTENTION IS THE POTENTIAL FOR HEAVY RAIN/FLOODING WITH MULTIPLE ROUNDS OF CONVECTION THIS WEEK. PW VALUES DO SURGE TO AROUND 1.5 INCHES LATE TONIGHT (AND INTO TOMORROW) AND HEAVY RAIN WILL CERTAINLY BE POSSIBLE WHEN/WHERE CONVECTION DOES OCCUR. HOWEVER...POTENTIAL FOR TRAINING AND BACKBUILDING CONVECTION IS LOW IN OUR AREA WITH RELATIVELY HIGH MBE VELOCITIES AND THE FACT THAT STORM MOTION BECOMES A LITTLE MORE ORTHOGONAL TO THE FRONT BY TOMORROW. OUTSIDE OF OUR FAR SOUTHEAST COUNTIES...MOST OF THE CWA HAS ALSO NOT RECEIVED A LARGE AMOUNT OF RAIN RECENTLY. THE THREAT FOR HEAVY RAIN AND LOCALIZED FLOODING DOES EXIST BUT CONFIDENCE IS NOT HIGH ENOUGH FOR ANY TYPE OF WATCH HEADLINE AT THIS POINT. AGAIN THE HIGHEST THREAT WILL BE IN OUR FAR SOUTHEAST COUNTIES. && .LONG TERM...(THURSDAY THROUGH WEDNESDAY) ISSUED AT 400 PM EDT WED APR 8 2015 PRIMARY CONCERN WILL BE SEVERE WEATHER CHANCES TONIGHT INTO THURSDAY NIGHT. ALOFT...A DEEP 500MB TROUGH IN THE WESTERN CONUS WILL GRADUALLY SHIFT EASTWARD INTO THE MIDWEST...TAKING ON A NEGATIVE TILT OVER IA/IL AS IT ATTEMPTS TO BREAK DOWN THE RIDGE FIRMLY ANCHORED OVER THE EAST COAST THURSDAY NIGHT. MODELS CLOSE THE LOW THU EVE BEFORE LIFTING IT INTO SOUTHERN ONTARIO BY FRIDAY AFTERNOON. AHEAD OF THE DEEPENING TROUGH...SFC LOW PRESSURE WILL DEVELOP OVER THE CENTRAL PLAINS THIS EVENING AND TRAVEL NORTHEASTWARD INTO SOUTHWESTERN IOWA BY 12Z THU. AS THE UPPER TROUGH/LOW APPROACHES THE LLJ WILL STRENGTHEN...INTENSIFYING THE WARM AIR/MOISTURE ADVECTION OVER THE CWA OVERNIGHT AND THURSDAY. AS A RESULT...THE CWA WILL BE IN THE WARM SECTOR FROM LATE TONIGHT INTO THURSDAY NIGHT. THIS WILL BRING CHANCES FOR SEVERE WEATHER. MOISTURE IS PLENTIFUL...WITH PWATS INCREASING TO NEAR 1.4 INCHES EARLY THU AFTERNOON. INSTABILITY IS DECENT...WITH LI VALUES RANGING FROM -5 TO -2/SFC BASED CAPE AS HIGH AS 1500 J/KG BY LATE AFTERNOON. 0-6KM SHEAR IS SOMEWHAT PALTRY AT FIRST...AROUND 20-30 KNOTS...BUT PICKS UP TO AROUND 40-50 KNOTS TOWARDS THE LATE AFTERNOON AS THE UPPER LEVEL TROUGH APPROACHES. SHOWER/T-STORM ACTIVITY FROM THE OVERNIGHT PERIOD WILL LIKELY CONTINUE THROUGH THE MORNING HOURS...WITH MODELS SUPPORTING SHOWER/T-STORM DEVELOPMENT ALONG THE STATIONARY/WARM FRONT THAT LIFTS NORTHWARD WITH THE BOUNDARY THROUGH THE MORNING. SEVERE POTENTIAL EARLIER IN THE DAY WILL BE LIMITED...WITH MORE MARGINAL INSTABILITY AND WEAK MID LEVEL LAPSE RATES. WITH ABUNDANT MOISTURE...AND WITH ANY THUNDERSTORMS...HEAVY RAIN IS A THREAT. FLOODING IS POSSIBLE IN AREAS THAT SEE HEAVY RAINFALL FROM SEVERAL ROUNDS OF STORMS TONIGHT INTO FRIDAY. THE STRONGEST STORMS ARE FORECAST TO INTIATE WITH THE COLD FRONT OVER THE IL AREA BY THU AFTERNOON...WHERE FRONT TIMING IS MORE FAVORABLE FOR SEVERE WX...DURING PEAK DAYTIME HEATING. EXPECT THESE STORMS TO CROSS INTO OUR WESTERN CWA WITH THE FRONT BY THURSDAY EVENING AND CONTINUE GENERALLY EASTWARD OVERNIGHT. THINKING THE 00-05Z TIME PERIOD IN THE WEST AND CENTRAL WILL BE THE BEST SHOT FOR SEVERE WEATHER...WHEN ALL SVR T-STORM INGREDIENTS COME TOGETHER FOR A BRIEF TIME. PRIMARY THREAT WOULD BE LARGE HAIL AND DAMAGING WINDS...BUT CANNOT RULE OUT THE POSSIBILITY OF TORNADOES GIVEN 0-1 KM SHEAR GREATER THAN 30 KNOTS FROM 00-05Z. THINKING THAT THE BIGGEST LIMITATION WITH THIS OVERALL SCENARIO IS INSTABILITY...MODELS TEND TO OVERDO IT IN GENERAL. THIS IS ESPECIALLY TRUE GIVEN THE UNCERTAINTY WITH THE MORNING CONVECTION...AND THE LATE TIMING OF THE COLD FRONT/MAJOR FORCING. TOOK A LOOK AT THE SHERB PARAMETER WHICH HAS SHOWN SOME SKILL IN EVALUATING HSLC ENVIRONMENTS FOR SEVERE POTENTIAL...AND VALUES WERE OVER 1-WHICH SUGGESTS A MORE SIGNIFICANT EVENT IS POSSIBLE. AFTER 03Z HOWEVER...INSTABILITY REALLY BEGINS TO WANE...AND DRIER AIR BEHIND THE FRONT QUICKLY INFILTRATES THE AREA. WOULD EXPECT ALL MEASURABLE PRECIP TO EXIT THE CWA BY 15Z FRI AS HIGH PRESSURE STARTS TO BUILD INTO THE AREA. A SECONDARY SHORTWAVE ROTATING AROUND THE UPPER LOW OVER SOUTHERN ONTARIO WILL DIVE SOUTHWARD FROM WI. MODELS SUGGEST PRECIPITATION CHANCES ASSOCIATED WITH THIS ACROSS SOUTHWESTERN/SOUTHERN LOWER MI...BUT THESE WILL BE LIMITED AT BEST. WINDS SHOULD GET GUSTY FRIDAY THOUGH...WITH A DECENT PRESSURE RISE/FALL COUPLET CROSSING THE CWA FRIDAY INTO FRI NIGHT. ALL GOES QUIET AGAIN WITH HIGH PRESSURE OVERHEAD...UNTIL SUNDAY NIGHT. AN UPPER LEVEL TROUGH/ASSOCIATED SURFACE LOW WILL MOVE FROM NORTHERN ONTARIO/UPPER MI/NORTHERN WI SUNDAY NIGHT AND CONTINUE INTO HUDSON BAY BY MONDAY AFTERNOON. THIS WILL BRING A COLD FRONT AND ADDITIONAL CHANCES FOR SHOWERS/T-STORMS DURING THIS TIME FRAME. AROUND THE SAME TIME...ANOTHER LOW DEVELOPS OVER THE CENTRAL PLAINS AND BEGINS TO LIFT NORTHWARD...WEAKENING AS IT LIFTS TOWARDS THE OHIO VALLEY TUE AND WED. THIS WILL ALLOW PRECIPITATION TO CONTINUE THROUGH MUCH OF NEXT WEEK. TEMPS WILL BE NEAR NORMAL FOR THIS TIME FRAME...MAINLY IN THE 60S AND LOW 70S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 143 AM EDT THU APR 9 2015 STORMS HAVE BLOWN UP ACROSS NORTHERN ILLINOIS AND NORTHERN INDIANA AS MOISTURE ADVECTION CONTINUES OVER THE STATIONARY FRONT SETTLED ACROSS THE AREA. FIRST ROUND OF STORMS HAS LIFTED NORTH OF BOTH TERMINALS...BUT ANTICIPATE ADDITIONAL STORM DEVELOPMENT OVERNIGHT AS THE LOW LEVEL JET STRENGTHENS AND ELEVATED INSTABILITY CONTINUES TO ADVECT INTO THE AREA. SOUTHERLY WINDS WILL STRENGTHEN THROUGH THE DAY AS A LOW PRESSURE SYSTEM APPROACHES FROM THE WEST. ADDITIONAL STORMS EXPECTED AFTER 00Z TOMORROW...BUT WILL WAIT TO INCLUDE A MENTION UNTIL LATER TAF ISSUANCES WHEN FINER SCALE DETAILS BECOME MORE APPARENT. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...JT SHORT TERM...AGD LONG TERM...MCD AVIATION...BENTLEY VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1133 PM MDT WED APR 8 2015 .UPDATE... ISSUED AT 922 PM MDT WED APR 8 2015 ISSUED A LARGE UPDATE TO AMEND SKY...WEATHER AND POP GRIDS FOR THIS EVENING THROUGH TOMORROW EVENING. FOG/STRATUS HAS PUSHED FARTHER SOUTH THAN MOST GUIDANCE ONCE AGAIN. HRRR AND RUC HAVE LOCKED ONTO STRATUS WHILE OTHER GUIDANCE PERSISTS WITH A POOR FORECAST. ALSO...INCREASED POPS TO ACCOUNT FOR SHOWERS...STORMS AND DRIZZLE TONIGHT AND SHOWERS/DRIZZLE TOMORROW. THE FOG/DRIZZLE SETUP IS ESSENTIALLY IDENTICAL TO THE PREVIOUS TWO NIGHTS. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 153 PM MDT WED APR 8 2015 AN UPPER TROUGH WILL MOVE EAST OF THE ROCKIES AND INTO THE PLAINS TONIGHT AND THURSDAY MORNING. THE TROUGH WILL SHIFT EAST INTO THE MISSOURI VALLEY THURSDAY AFTERNOON. A SURFACE TROUGH WILL MOVE FROM EASTERN COLORADO INTO NORTHWEST KANSAS TONIGHT. A COLD FRONT WILL MOVE IN BEHIND THE TROUGH THURSDAY. PLAN TO KEEP CURRENT RED FLAG WARNING TO EXPIRATION AT 02Z THURSDAY. DO NOT SEE ANY NEED TO ADD ANY ZONES TO THE RED FLAG WARNING AT THIS TIME. MODELS SHOW STRONG SOUTHWEST WINDS SHOULD NOT GET INTO WALLACE OR GREELEY COUNTIES IN KANSAS AND IF THEY DO THE WINDOW WOULD BE BRIEF TOWARD EVENING WHEN RELATIVE HUMIDITY SHOULD START RECOVERING. DYNAMICS FROM THE UPPER TROUGH TONIGHT WILL BRING A CHANCE OF SHOWERS TO MAINLY YUMA COUNTY AND THE EXTREME SOUTHWEST NEBRASKA ZONES WHERE H8-7 LAYER MEAN RH IS THE BEST. SLIGHT CHANCE POPS WILL BE IN PLACE FOR ZONES JUST TO THE NORTH OF HIGHWAY 36 TO THE NEBRASKA BORDER WHERE MOISTURE IS LESS FAVORABLE. THERE IS ENOUGH CAPE (200-400 J/KG) TO SUPPORT ISOLATED THUNDERSTORMS SO WILL KEEP THOSE IN THE FORECAST. BOUNDARY LAYER RH WILL INCREASE ABOVE 90 PERCENT IN THE EASTERN FA LATER THIS EVENING AND SPREAD WEST ACROSS MOST OF THE FA OVERNIGHT. VISIBILITIES SHOULD BE HIGH ENOUGH SO THAT A HIGHLIGHT WILL NOT BE NEEDED. THE COLD FRONT THAT MOVES INTO THE FA EARLY THURSDAY MORNING SHOULD ERODE THE STRATUS AND FOG FROM WEST TO EAST. WIND SPEEDS SHOULD REMAIN BELOW HIGH WIND CRITERIA. MIN TEMPERATURES TONIGHT WILL BE HELD UP BY CLOUDS AND MIXING. EXPECT LOW TEMPERATURES IN THE THE UPPER 30S AND LOWER 40S. MAX TEMPERATURES THURSDAY BEHIND THE COLD FRONT SHOULD ONLY REACH INTO THE LOWER 50S TO MID 50S. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 107 PM MDT WED APR 8 2015 SUBSIDENCE AND SHORTWAVE RIDGING BEHIND DEPARTING SYSTEM WILL RESULT IN DRY CONDITIONS THURSDAY NIGHT THROUGH FRIDAY NIGHT. TEMPERATURES DURING THAT PERIOD WILL BE SLIGHTLY ABOVE NORMAL. SHORTWAVE TROUGH EMERGING FROM THE CENTRAL ROCKIES WILL BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS SATURDAY AND SATURDAY NIGHT. BEST MOISTURE WILL BE IN NORTHWEST KANSAS AND SOUTHWEST NEBRASKA SATURDAY AFTERNOON AND EVENING WHERE MODERATE INSTABILITY OF UP TO 2000 J/KG AND DEEP LAYER SHEAR OF 35-40KTS WILL RESIDE. THOSE PARAMETERS SHOULD BE SUFFICIENT FOR A FEW SEVERE STORMS WITH LARGE HAIL AND DAMAGING WINDS THE PRIMARY HAZARDS. FRONT DROPS DOWN BEHIND THAT SYSTEM SO THAT BY SUNDAY BEST MOISTURE AND INSTABILITY WILL BE SOUTH OF THE AREA. SO OTHER THAN A FEW LINGERING POPS IN THE MORNING FOR THE FAR EASTERN COUNTIES THINK IT WILL BE DRY DURING THE DAY SUNDAY WITH TEMPERATURES ABOVE NORMAL. CUT OFF SYSTEM IN THE DESERT SOUTHWEST WILL EMERGE ONTO THE SOUTHERN PLAINS SUNDAY NIGHT AND POSSIBLY IMPACT THE AREA WITH A CHANCES FOR PRECIPITATION SUNDAY NIGHT THROUGH TUESDAY AS IT EJECTS NORTHEASTWARD. SURFACE BASED INSTABILITY DURING THAT TIME NOT VERY IMPRESSIVE BUT PLENTY OF MUCAPE AVAILABLE SO WOULD EXPECT SCATTERED SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS. TEMPERATURES WILL COOL DOWN ESPECIALLY ON MONDAY. ANOTHER DEEP TROUGH IS FORECAST TO CUT OFF OVER THE NORTHERN ROCKIES MID WEEK AND SLOWLY MOVE ONTO THE CENTRAL PLAINS. IT MAY TAKE ITS TIME GETTING HERE AND IF THE TRACK IS TOO FAR NORTH WE MAY GET DRY SLOTTED ANYWAY. NONETHELESS WILL CARRY SOME SLIGHT CHANCE POPS ON WEDNESDAY IN NORTHEAST COLORADO AS IT SLOWLY MOVES INTO THE AREA WITH TEMPERATURES ABOVE TO MUCH ABOVE NORMAL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1133 PM MDT WED APR 8 2015 LOW CONFIDENCE FORECAST THIS RUN AS GUIDANCE CONTINUES STRUGGLE WITH FOG/DRIZZLE/STRATUS PLACEMENT. MOST ALL GUIDANCE KEEPS STRATUS TOO FAR NORTH BUT INITIAL FRONT HAS RETROGRADED FARTHER SOUTH THAN ANTICIPATED ONCE AGAIN. WENT WITH A PESSIMISTIC FORECAST SIMILAR TO ONGOING OBSERVATIONS AND WHAT OCCURRED PAST TWO NIGHTS. VARIABLE CIGS/VIS LIKELY LATER THIS MORNING AS A STRONGER COLD FRONT PASSES THROUGH...INCREASING ATMOSPHERIC MIXING. OVERALL...EXPECTING AN IMPROVING TREND FROM LATE MORNING INTO THE AFTERNOON. NORTH WINDS BACK NORTHEAST BY MORNING AND INCREASE SIGNIFICANTLY IN SPEED BEHIND THE STRONGER COLD FRONT. ANTICIPATE GUSTY WINDS THROUGHOUT THE LATE MORNING/AFTERNOON TODAY. WINDS RELAX UNDER VFR CIGS/VIS BEFORE SUNSET. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...RRH SHORT TERM...FS LONG TERM...024 AVIATION...RRH
AREA FORECAST DISCUSSION
NWS JACKSON KY
642 PM EDT THU APR 9 2015 .UPDATE... ISSUED AT 641 PM EDT THU APR 9 2015 JUST UPDATED THE GRIDS...ZONE FORECAST TEXT PRODUCT...AND HAZARDOUS WEATHER PRODUCT TO ALL REFLECT THE CANCELLATION OF SEVERE THUNDERSTORM WATCH 40. WITH ONLY A FEW MEAGER THUNDERSTORMS HAVING MOVED ACROSS THE AREA SO FAR THIS EVENING...AND WITH NO NEW STORMS EXPECTED TO AFFECT THE AREA ANY TIME SOON...THE WATCH WAS CANCELLED. THE FLASH FLOOD WATCH IS STILL IN EFFECT. THE GRIDS WERE ALSO FRESHENED UP A BIT USING THE LATEST OBS DATA ACROSS THE BOARD. WILL CONTINUE TO MONITOR CURRENT CONDITIONS TO DETERMINE WHEN TO ISSUE THE NEXT FORECAST UPDATE. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 351 PM EDT THU APR 9 2015 MODELS ARE IN GOOD AGREEMENT IN THE SHORT TERM WITH EASTERN KENTUCKY REMAINING UNDER BROAD SW FLOW TODAY BEFORE AN UL TROUGH SWINGS THROUGH THE AREA THIS EVENING. A WARM FRONT REMAINS TO OUR NORTH...HELPING TO FOCUS SOME OF THE MORE INTENSE CONVECTION SO FAR THIS AFTERNOON. HOWEVER...GIVEN THAT THE ATMOSPHERE IS VERY MOIST AND UNSTABLE...THERE IS STILL A CHANCE FOR SCATTERED CONVECTION ACROSS OUR CWA THIS AFTERNOON AND EVENING WITH BEST CHANCES ALONG THE NORTHERN COUNTIES WHERE A SPC SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED. AND AS THE UL TROUGH APPROACHES THE AREA ALLOWING FOR ADDITIONAL HEIGHT FALLS AND UL ENERGY...THE CHANCES FOR THUNDERSTORMS INCREASE. HIGH RES MODELS SUCH AS THE HRRR AND NAM12 BOTH INDICATE A LULL IN CONVECTION TONIGHT AFTER THE DIURNAL CONVECTION WANES AND BEFORE THE COLD FRONT REACHES OUR AREA. AS SUCH...HAVE INDICATED A DECREASE IN SHOWERS/CONVECTION DURING THAT TIME IN THE POP/SKY/WX GRIDS. BY THE TIME THE COLD FRONT REACHES KY AROUND 06Z...SHOWERS AND THUNDERSTORMS WILL BE NUMEROUS AND WIDESPREAD ACROSS THE MAJORITY OF THE STATE. PER LATEST MODEL OUTPUT AND SOUNDINGS...A CONVECTIVE LINE COULD DEVELOP ALONG AND AHEAD OF THE COLD FRONT OVERNIGHT TONIGHT...ALLOWING FOR A THREAT OF HIGH WINDS AND HEAVY RAIN. WILL HAVE TO SEE HOW THE CONVECTION FORMS WITH THE FRONTAL BOUNDARY LATER TONIGHT...BUT IT IS LIKELY THAT THERE WILL BE AT LEAST WIDESPREAD RAINFALL WITH SOME THUNDERSTORMS AS THE FRONT PASSES THROUGH THE REGION TONIGHT. THERE WONT BE THE ADDED BENEFIT OF DAYTIME HEATING BUT THERE WILL BE ENOUGH MID TO UPPER LEVEL SUPPORT FOR CONVECTION TO SUSTAIN ITSELF. THE COLD FRONT SHOULD THEN EXIT EASTERN KY BY 18Z...FOLLOWED QUICKLY BY COOLER...DRIER AIR AND N TO NW FLOW. THE COOLER AIR BEHIND THE FRONT WILL QUICKLY CUT OFF ANY REMAINING SHOWER ACTIVITY AND DRY THE AIR...DECREASING HUMIDITY LEVELS SUBSTANTIALLY. THIS WILL ALLOW FOR TEMPERATURES TO REMAIN NEAR NORMAL VALUES...IN THE MID 60S...ON SATURDAY AS A HIGH PRESSURE SITS OVERHEAD. THIS IS A BIG CHANGE FROM TODAY/S TEMPERATURES WHICH HAVE SURPASSED THE 80 DEGREE MARK FOR THE FIRST TIME THIS YEAR. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 501 PM EDT THU APR 9 2015 A LARGE AREA OF SURFACE HIGH PRESSURE OVER THE OHIO VALLEY ON SATURDAY WILL BRING DRY WEATHER WHICH SHOULD LAST INTO SUNDAY NIGHT. BY THEN THE HIGH WILL BE MOVING OFF THE EAST COAST...AND MODELS SHOW GULF MOISTURE TRYING TO MAKE A RETURN TO THE NORTH AS ANOTHER COLD FRONT PUSHES IN FROM THE NW. IT NOW LOOKS LIKE THIS FRONT WILL BRING A QUICK CHANCE AT SOME SHOWERS ON MONDAY INTO MONDAY NIGHT. MODELS HAVE NOT BEEN CONSISTENT IN THEIR SOLUTIONS FOR TUESDAY THROUGH THURSDAY. THE 12Z RUNS OF BOTH THE GFS AND ECMWF NOW SUGGEST MAINLY DRY WEATHER FOR TUESDAY INTO WEDNESDAY AS HIGH PRESSURE SLIDES BY TO OUR NORTH...AND THE AFOREMENTIONED COLD FRONT STALLS TO OUR SOUTH AND KEEPS MOISTURE AT BAY. HOWEVER...WITH THIS BEING A RECENT CHANGE...HAVE ONLY TRENDED THE POP LOWER INSTEAD OF REMOVING PRECIP FROM THE FORECAST. 12Z RUNS SHOW A RETURN OF GULF MOISTURE FROM WEDNESDAY INTO THURSDAY...BUT LITTLE IN THE WAY OF INSTABILITY AND HAVE CONTINUED CHANCE POPS FOR SHOWERS AT THAT TIME. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 641 PM EDT THU APR 9 2015 VFR CONDITIONS WILL PREVAIL AT THE TAF SITES THROUGH 9 OR 10Z TONIGHT. BASED ON THE LATEST MODEL AND OBS DATA...SHOWERS AND THUNDERSTORMS WILL NOT BE AFFECTING THE TAF SITES UNTIL AROUND DAWN ON FRIDAY. A COLD FRONT WILL BE MOVING TOWARD THE AREA OVERNIGHT...AND UNTIL IT ARRIVES...IT WILL BE DIFFICULT FOR SHOWERS AND STORMS TO FORM UNDER THE CURRENT ATMOSPHERIC CONDITIONS. ONCE THE STORMS DO ARRIVE...THE TAF SITES CAN EXPECTED TORRENTIAL RAIN...FREQUENT LIGHTNING...STRONG WINDS...AND MVFR TO POSSIBLY LIFR CONDITIONS. THE SHOWERS AND STORMS WILL MOVE STEADILY ACROSS EASTERN KENTUCKY DURING THE DAY ON FRIDAY...AND SHOULD BE OUT OF THE AREA BY NEAR THE END OF THE TAF PERIOD. && .JKL WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. && $$ UPDATE...AR SHORT TERM...JVM LONG TERM...HAL AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
502 PM EDT THU APR 9 2015 .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 351 PM EDT THU APR 9 2015 MODELS ARE IN GOOD AGREEMENT IN THE SHORT TERM WITH EASTERN KENTUCKY REMAINING UNDER BROAD SW FLOW TODAY BEFORE AN UL TROUGH SWINGS THROUGH THE AREA THIS EVENING. A WARM FRONT REMAINS TO OUR NORTH...HELPING TO FOCUS SOME OF THE MORE INTENSE CONVECTION SO FAR THIS AFTERNOON. HOWEVER...GIVEN THAT THE ATMOSPHERE IS VERY MOIST AND UNSTABLE...THERE IS STILL A CHANCE FOR SCATTERED CONVECTION ACROSS OUR CWA THIS AFTERNOON AND EVENING WITH BEST CHANCES ALONG THE NORTHERN COUNTIES WHERE A SPC SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED. AND AS THE UL TROUGH APPROACHES THE AREA ALLOWING FOR ADDITIONAL HEIGHT FALLS AND UL ENERGY...THE CHANCES FOR THUNDERSTORMS INCREASE. HIGH RES MODELS SUCH AS THE HRRR AND NAM12 BOTH INDICATE A LULL IN CONVECTION TONIGHT AFTER THE DIURNAL CONVECTION WANES AND BEFORE THE COLD FRONT REACHES OUR AREA. AS SUCH...HAVE INDICATED A DECREASE IN SHOWERS/CONVECTION DURING THAT TIME IN THE POP/SKY/WX GRIDS. BY THE TIME THE COLD FRONT REACHES KY AROUND 06Z...SHOWERS AND THUNDERSTORMS WILL BE NUMEROUS AND WIDESPREAD ACROSS THE MAJORITY OF THE STATE. PER LATEST MODEL OUTPUT AND SOUNDINGS...A CONVECTIVE LINE COULD DEVELOP ALONG AND AHEAD OF THE COLD FRONT OVERNIGHT TONIGHT...ALLOWING FOR A THREAT OF HIGH WINDS AND HEAVY RAIN. WILL HAVE TO SEE HOW THE CONVECTION FORMS WITH THE FRONTAL BOUNDARY LATER TONIGHT...BUT IT IS LIKELY THAT THERE WILL BE AT LEAST WIDESPREAD RAINFALL WITH SOME THUNDERSTORMS AS THE FRONT PASSES THROUGH THE REGION TONIGHT. THERE WONT BE THE ADDED BENEFIT OF DAYTIME HEATING BUT THERE WILL BE ENOUGH MID TO UPPER LEVEL SUPPORT FOR CONVECTION TO SUSTAIN ITSELF. THE COLD FRONT SHOULD THEN EXIT EASTERN KY BY 18Z...FOLLOWED QUICKLY BY COOLER...DRIER AIR AND N TO NW FLOW. THE COOLER AIR BEHIND THE FRONT WILL QUICKLY CUT OFF ANY REMAINING SHOWER ACTIVITY AND DRY THE AIR...DECREASING HUMIDITY LEVELS SUBSTANTIALLY. THIS WILL ALLOW FOR TEMPERATURES TO REMAIN NEAR NORMAL VALUES...IN THE MID 60S...ON SATURDAY AS A HIGH PRESSURE SITS OVERHEAD. THIS IS A BIG CHANGE FROM TODAY/S TEMPERATURES WHICH HAVE SURPASSED THE 80 DEGREE MARK FOR THE FIRST TIME THIS YEAR. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 501 PM EDT THU APR 9 2015 A LARGE AREA OF SURFACE HIGH PRESSURE OVER THE OHIO VALLEY ON SATURDAY WILL BRING DRY WEATHER WHICH SHOULD LAST INTO SUNDAY NIGHT. BY THEN THE HIGH WILL BE MOVING OFF THE EAST COAST...AND MODELS SHOW GULF MOISTURE TRYING TO MAKE A RETURN TO THE NORTH AS ANOTHER COLD FRONT PUSHES IN FROM THE NW. IT NOW LOOKS LIKE THIS FRONT WILL BRING A QUICK CHANCE AT SOME SHOWERS ON MONDAY INTO MONDAY NIGHT. MODELS HAVE NOT BEEN CONSISTENT IN THEIR SOLUTIONS FOR TUESDAY THROUGH THURSDAY. THE 12Z RUNS OF BOTH THE GFS AND ECMWF NOW SUGGEST MAINLY DRY WEATHER FOR TUESDAY INTO WEDNESDAY AS HIGH PRESSURE SLIDES BY TO OUR NORTH...AND THE AFOREMENTIONED COLD FRONT STALLS TO OUR SOUTH AND KEEPS MOISTURE AT BAY. HOWEVER...WITH THIS BEING A RECENT CHANGE...HAVE ONLY TRENDED THE POP LOWER INSTEAD OF REMOVING PRECIP FROM THE FORECAST. 12Z RUNS SHOW A RETURN OF GULF MOISTURE FROM WEDNESDAY INTO THURSDAY...BUT LITTLE IN THE WAY OF INSTABILITY AND HAVE CONTINUED CHANCE POPS FOR SHOWERS AT THAT TIME. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 351 PM EDT THU APR 9 2015 THE AVIATION DISCUSSION WILL BE ISSUED SHORTLY. && .JKL WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. && $$ SHORT TERM...JVM LONG TERM...HAL AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
351 PM EDT THU APR 9 2015 .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 351 PM EDT THU APR 9 2015 MODELS ARE IN GOOD AGREEMENT IN THE SHORT TERM WITH EASTERN KENTUCKY REMAINING UNDER BROAD SW FLOW TODAY BEFORE AN UL TROUGH SWINGS THROUGH THE AREA THIS EVENING. A WARM FRONT REMAINS TO OUR NORTH...HELPING TO FOCUS SOME OF THE MORE INTENSE CONVECTION SO FAR THIS AFTERNOON. HOWEVER...GIVEN THAT THE ATMOSPHERE IS VERY MOIST AND UNSTABLE...THERE IS STILL A CHANCE FOR SCATTERED CONVECTION ACROSS OUR CWA THIS AFTERNOON AND EVENING WITH BEST CHANCES ALONG THE NORTHERN COUNTIES WHERE A SPC SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED. AND AS THE UL TROUGH APPROACHES THE AREA ALLOWING FOR ADDITIONAL HEIGHT FALLS AND UL ENERGY...THE CHANCES FOR THUNDERSTORMS INCREASE. HIGH RES MODELS SUCH AS THE HRRR AND NAM12 BOTH INDICATE A LULL IN CONVECTION TONIGHT AFTER THE DIURNAL CONVECTION WANES AND BEFORE THE COLD FRONT REACHES OUR AREA. AS SUCH...HAVE INDICATED A DECREASE IN SHOWERS/CONVECTION DURING THAT TIME IN THE POP/SKY/WX GRIDS. BY THE TIME THE COLD FRONT REACHES KY AROUND 06Z...SHOWERS AND THUNDERSTORMS WILL BE NUMEROUS AND WIDESPREAD ACROSS THE MAJORITY OF THE STATE. PER LATEST MODEL OUTPUT AND SOUNDINGS...A CONVECTIVE LINE COULD DEVELOP ALONG AND AHEAD OF THE COLD FRONT OVERNIGHT TONIGHT...ALLOWING FOR A THREAT OF HIGH WINDS AND HEAVY RAIN. WILL HAVE TO SEE HOW THE CONVECTION FORMS WITH THE FRONTAL BOUNDARY LATER TONIGHT...BUT IT IS LIKELY THAT THERE WILL BE AT LEAST WIDESPREAD RAINFALL WITH SOME THUNDERSTORMS AS THE FRONT PASSES THROUGH THE REGION TONIGHT. THERE WONT BE THE ADDED BENEFIT OF DAYTIME HEATING BUT THERE WILL BE ENOUGH MID TO UPPER LEVEL SUPPORT FOR CONVECTION TO SUSTAIN ITSELF. THE COLD FRONT SHOULD THEN EXIT EASTERN KY BY 18Z...FOLLOWED QUICKLY BY COOLER...DRIER AIR AND N TO NW FLOW. THE COOLER AIR BEHIND THE FRONT WILL QUICKLY CUT OFF ANY REMAINING SHOWER ACTIVITY AND DRY THE AIR...DECREASING HUMIDITY LEVELS SUBSTANTIALLY. THIS WILL ALLOW FOR TEMPERATURES TO REMAIN NEAR NORMAL VALUES...IN THE MID 60S...ON SATURDAY AS A HIGH PRESSURE SITS OVERHEAD. THIS IS A BIG CHANGE FROM TODAY/S TEMPERATURES WHICH HAVE SURPASSED THE 80 DEGREE MARK FOR THE FIRST TIME THIS YEAR. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 351 PM EDT THU APR 9 2015 THE LONG TERM DISCUSSION WILL BE ISSUED SHORTLY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 351 PM EDT THU APR 9 2015 THE AVIATION DISCUSSION WILL BE ISSUED SHORTLY. && && .JKL WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. && $$ SHORT TERM...JVM LONG TERM...HAL AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
249 PM EDT THU APR 9 2015 .UPDATE... ISSUED AT 1255 PM EDT THU APR 9 2015 QUICK UPDATE TO ALIGN T AND TD GRIDS WITH MOST RECENT OBS. DID END UP BUMPING THE HIGH TEMP FOR THE DAY UP A DEGREE GIVEN THE FACT THAT WE HAVE ALREADY REACHED 80 DEGREES BY NOON. CLOUD COVER AND STORM COVERAGE INCREASING THIS AFTERNOON COULD HELP KEEP TEMPS IN THE LOW TO MID 80S. UPDATE ISSUED AT 945 AM EDT THU APR 9 2015 INCREASED POPS A BIT ACROSS OUR EXTREME NORTHERN COUNTIES THIS AFTERNOON AS THE LATEST HRRR RUN SHOWS SOME SCATTERED THUNDERSTORMS POPPING UP ACROSS THE NORTH. THE NAM12 IS A BIT MORE AGGRESSIVE WITH A LARGER AREA OF RAIN THIS AFTERNOON. THOUGH...STILL HAVE UNCERTAINTY AS TO WHERE THE STORMS WILL SET UP AND MOVE SO HAVE LEFT MOSTLY CHANCE POPS IN THE GRIDS. ALSO UPDATED T AND TD GRIDS TO ALIGN WITH MOST RECENT OBS. SENT UPDATED GRIDS TO WEB SERVERS AND NDFD. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 411 AM EDT THU APR 9 2015 EASTERN KY CURRENTLY FINDS ITSELF IN A LULL...WITH EVENING SHOWERS AND THUNDERSTORMS HAVING EXITED TO THE EAST AND NORTHEAST. THE NEXT ROUND OF SHOWERS...CURRENTLY OVER FAR WESTERN KY...WILL BE IN RESPONSE TO AN APPROACHING LOW PRESSURE SYSTEM AND COLD FRONTAL BOUNDARY. AS WE HEAD INTO THE DAYLIGHT HOURS...EXPECT SOME ISOLATED TO SCATTERED CONVECTION TO POP UP ACROSS EASTERN KY DUE TO MOST WARM UNSTABLE AIR BEING PULLED IN FROM THE GULF OF MEXICO. HOWEVER...EXPECT MOST OF THE CONVECTION TO REMAIN TO OUR WEST AND NORTH CLOSER TO THE BOUNDARY. GIVEN THE UNSTABLE NATURE OF THE ATMOSPHERE...A NEARBY SOURCE OF LIFT IN THE BOUNDARY...AND SO MUCH MOISTURE AT PLAY...IT IS HIGHLY POSSIBLE THAT ANY THUNDERSTORMS WHICH DO DEVELOP COULD PUT DOWN SOME LOCALLY HEAVY TO TORRENTIAL RAINFALL...AS WELL AS PRODUCE LARGE HAIL AND DAMAGING WINDS. FOR ONCE...WE WILL HAVE A SHOT OF DECENT CAPE VALUES IN ADDITION TO SFC-6KM SHEAR OF 40 AND HIGHER BY THIS AFTERNOON...WHERE AS PREVIOUS EVENTS OF LATE HAVE BEEN LACKING ONE OR THE OTHER. THE COLD FRONT WILL SHIFT EASTWARD AND REACH WESTERN KY BY 06Z FRIDAY...AT WHICH POINT A BROAD AREA OF SHOWERS AND THUNDERSTORMS WILL HAVE ENCOMPASSED MUCH OF KENTUCKY. EXPECT AN AREA OF MORE WIDESPREAD COVERAGE TO MOVE INTO THE JKL CWA BY AROUND 6Z AND CONTINUE THROUGH FRIDAY MORNING AS THE FRONT CONTINUES TO APPROACH. GIVEN THE LATEST NAM12 FORECAST SOUNDINGS...IT LOOKS LIKE A LINE OF STORMS COULD DEVELOP...WITH HEAVY TO TORRENTIAL RAINS...AND STRONG TO DAMAGING WIND GUSTS MIXING DOWN AS IT RACES EASTWARD AHEAD OF THE FRONT. LATEST GFS40 FORECAST HAS THE COLD FRONT ENTERING INTO THE WESTERN PORTION OF THE CWA BY 12Z FRIDAY...AND EXITING TO THE EAST OF THE STATE AROUND 18Z. JUST BEHIND THE FRONTAL PASSAGE..MUCH DRIER W TO NW FLOW WILL TAKE HOLD...BRINGING A QUICK END TO ANY SHOWERS AND THUNDERSTORMS ACROSS THE REGION. IT WILL ALSO WORK TO QUICKLY COOL OFF TEMPERATURES QUITE QUICKLY...WITH MUCH LESS HUMIDITY EXPECTED AS WE GO INTO THE WEEKEND. TODAY/S TEMPERATURES WILL LIKELY TO RISE WELL INTO THE 80S BY EARLY AFTERNOON...THANKS TO THE PREFRONTAL WARM AIR ADVECTION. HOWEVER FOR TOMORROW...ONGOING CLOUDS AND RAIN...AS WELL AS THE PULL OF COLDER AIR INTO THE REGION DURING NORMAL PEAK HEATING TIMES...WILL KEEP TEMPERATURES TOPPING OUT IN THE MID AND UPPER 60S. MUCH OF THE CWA HAS BEEN VERY WORKED OVER WITH RECENT HEAVY RAINS. IT WILL NOT TAKE MUCH TO CREATE AN EXCESS OF RUNOFF WITH ANY HEAVY RAIN SHOWER/THUNDERSTORM WE RECEIVE THROUGH FRIDAY AFTERNOON. MORE SO...THE FORECASTED PWATS AND POTENTIAL FOR HEAVY RAINFALL ARE HIGH...ESPECIALLY AS WE MOVE INTO FRIDAY. AS SUCH...WENT AHEAD AND EXPANDED THE WATCH ACROSS THE ENTIRE CWA...AS WELL AS EXTENDED IT UNTIL NOON FRIDAY WHEN THE HEAVIEST RAINFALL IS EXPECTED TO HAVE EXITED THE REGION AHEAD OF THE PASSING FRONTAL BOUNDARY. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 534 AM EDT THU APR 9 2015 THE MODELS ARE IN GOOD AGREEMENT WITH A FLATTER SPLIT FLOW PATTERN TO CONTROL ACROSS THE CONUS THROUGH EARLY NEXT WEEK...BEFORE BECOMING MORE AMPLIFIED TOWARDS THE END OF THE PERIOD. STUCK CLOSE TO A BLENDED SOLUTION...AS SMALLER SCALE DETAILS BECOME TOO DIFFICULT TO FORECAST WITH ANY CONFIDENCE. A COOLER AND LESS HUMID WEEKEND IS IN STORE FOR THE OHIO AND TENNESSEE VALLEYS. HIGHS WILL DROP BACK INTO THE 60S AND 70S FOR SATURDAY AND SUNDAY...WITH LOWS SUNDAY MORNING POSSIBLY DOWN INTO THE 30S FOR THE MORE SHELTERED VALLEYS. A NORTHERN STREAM SHORT WAVE TROUGH WILL MOVE FROM THE PLAINS TO THE GREAT LAKES SUNDAY INTO MONDAY...ALLOWING A COLD FRONT TO SHEAR OUT ACROSS THE OHIO VALLEY...RENEWING THE POP CHANCES. A SOUTHERN STREAM UPPER LEVEL LOW WILL ALSO BE MOVING NORTHEAST OUT OF THE DESERT SOUTHWEST...TRANSITIONING TO AN OPEN WAVE. THIS WILL USHER IN DEEPER MOISTURE BACK INTO EASTERN KENTUCKY...ALONG WITH PROVIDING SOME INTERACTION WITH THE LEFTOVER SURFACE FRONTAL BOUNDARY. DAILY CHANCES OF SHOWERS AND THUNDERSTORMS WILL CONTINUE WELL INTO NEXT WEEK. AGAIN...STUCK CLOSE TO A BLENDED SOLUTION...HOWEVER DID ALLOW FOR MORE OF A DIURNAL INFLUENCE ON THE POPS GIVEN THE UNCERTAINTY IN THE TIMING OF INDIVIDUAL FEATURES. HIGHS EACH DAY WILL AVERAGE IN THE LOW TO MID 70S...WITH LOWS IN THE LOW TO MID 50S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 248 PM EDT THU APR 9 2015 ISOLATED SHOWERS AND THUNDERSTORMS WERE DEVELOPING AND QUICKLY MOVING NE OVER THE REGION AT THE START OF THE PERIOD. A FEW OF THEM MAY CONTAIN IFR CONDITIONS...STRONG WINDS...AND HAIL THIS AFTERNOON. HOWEVER...THE GREATER THREAT MAY BE A BIT FURTHER NORTH. OUTSIDE OF PRECIP...VFR IS EXPECTED THIS AFTERNOON. WILL LOOK FOR MAINLY VFR AND A RELATIVE LULL IN PRECIP THIS EVENING...BEFORE A COLD FRONT MOVES IN FROM THE NW OVERNIGHT AND BRINGS SHOWERS AND THUNDERSTORMS FOR ALL LOCATIONS. THE BULK OF THE OVERNIGHT PRECIP IS EXPECTED TO ARRIVE FROM NW TO SE BETWEEN ABOUT 08Z AND 12Z. CONDITIONS SHOULD DETERIORATE TO MFR AND POSSIBLY IFR AT TIMES. PRECIP WILL THEN MOVE OUT OF THE REGION FROM NW TO SE BETWEEN ABOUT 13Z AND 17Z...BUT CEILINGS MOSTLY IN THE MVFR RANGE WILL LIKELY LINGER. WIND GUSTS AROUND 20 KT FROM THE SW WILL OCCUR AT TIMES THIS AFTERNOON...WITH GUSTINESS POSSIBLY PERSISTING INTO TONIGHT. WINDS WILL SHIFT TO THE WEST ON FRIDAY MORNING. && .JKL WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. && $$ UPDATE...JVM SHORT TERM...JMW LONG TERM...GEOGERIAN AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
1255 PM EDT THU APR 9 2015 .UPDATE... ISSUED AT 1255 PM EDT THU APR 9 2015 QUICK UPDATE TO ALIGN T AND TD GRIDS WITH MOST RECENT OBS. DID END UP BUMPING THE HIGH TEMP FOR THE DAY UP A DEGREE GIVEN THE FACT THAT WE HAVE ALREADY REACHED 80 DEGREES BY NOON. CLOUD COVER AND STORM COVERAGE INCREASING THIS AFTERNOON COULD HELP KEEP TEMPS IN THE LOW TO MID 80S. UPDATE ISSUED AT 945 AM EDT THU APR 9 2015 INCREASED POPS A BIT ACROSS OUR EXTREME NORTHERN COUNTIES THIS AFTERNOON AS THE LATEST HRRR RUN SHOWS SOME SCATTERED THUNDERSTORMS POPPING UP ACROSS THE NORTH. THE NAM12 IS A BIT MORE AGGRESSIVE WITH A LARGER AREA OF RAIN THIS AFTERNOON. THOUGH...STILL HAVE UNCERTAINTY AS TO WHERE THE STORMS WILL SET UP AND MOVE SO HAVE LEFT MOSTLY CHANCE POPS IN THE GRIDS. ALSO UPDATED T AND TD GRIDS TO ALIGN WITH MOST RECENT OBS. SENT UPDATED GRIDS TO WEB SERVERS AND NDFD. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 411 AM EDT THU APR 9 2015 EASTERN KY CURRENTLY FINDS ITSELF IN A LULL...WITH EVENING SHOWERS AND THUNDERSTORMS HAVING EXITED TO THE EAST AND NORTHEAST. THE NEXT ROUND OF SHOWERS...CURRENTLY OVER FAR WESTERN KY...WILL BE IN RESPONSE TO AN APPROACHING LOW PRESSURE SYSTEM AND COLD FRONTAL BOUNDARY. AS WE HEAD INTO THE DAYLIGHT HOURS...EXPECT SOME ISOLATED TO SCATTERED CONVECTION TO POP UP ACROSS EASTERN KY DUE TO MOST WARM UNSTABLE AIR BEING PULLED IN FROM THE GULF OF MEXICO. HOWEVER...EXPECT MOST OF THE CONVECTION TO REMAIN TO OUR WEST AND NORTH CLOSER TO THE BOUNDARY. GIVEN THE UNSTABLE NATURE OF THE ATMOSPHERE...A NEARBY SOURCE OF LIFT IN THE BOUNDARY...AND SO MUCH MOISTURE AT PLAY...IT IS HIGHLY POSSIBLE THAT ANY THUNDERSTORMS WHICH DO DEVELOP COULD PUT DOWN SOME LOCALLY HEAVY TO TORRENTIAL RAINFALL...AS WELL AS PRODUCE LARGE HAIL AND DAMAGING WINDS. FOR ONCE...WE WILL HAVE A SHOT OF DECENT CAPE VALUES IN ADDITION TO SFC-6KM SHEAR OF 40 AND HIGHER BY THIS AFTERNOON...WHERE AS PREVIOUS EVENTS OF LATE HAVE BEEN LACKING ONE OR THE OTHER. THE COLD FRONT WILL SHIFT EASTWARD AND REACH WESTERN KY BY 06Z FRIDAY...AT WHICH POINT A BROAD AREA OF SHOWERS AND THUNDERSTORMS WILL HAVE ENCOMPASSED MUCH OF KENTUCKY. EXPECT AN AREA OF MORE WIDESPREAD COVERAGE TO MOVE INTO THE JKL CWA BY AROUND 6Z AND CONTINUE THROUGH FRIDAY MORNING AS THE FRONT CONTINUES TO APPROACH. GIVEN THE LATEST NAM12 FORECAST SOUNDINGS...IT LOOKS LIKE A LINE OF STORMS COULD DEVELOP...WITH HEAVY TO TORRENTIAL RAINS...AND STRONG TO DAMAGING WIND GUSTS MIXING DOWN AS IT RACES EASTWARD AHEAD OF THE FRONT. LATEST GFS40 FORECAST HAS THE COLD FRONT ENTERING INTO THE WESTERN PORTION OF THE CWA BY 12Z FRIDAY...AND EXITING TO THE EAST OF THE STATE AROUND 18Z. JUST BEHIND THE FRONTAL PASSAGE..MUCH DRIER W TO NW FLOW WILL TAKE HOLD...BRINGING A QUICK END TO ANY SHOWERS AND THUNDERSTORMS ACROSS THE REGION. IT WILL ALSO WORK TO QUICKLY COOL OFF TEMPERATURES QUITE QUICKLY...WITH MUCH LESS HUMIDITY EXPECTED AS WE GO INTO THE WEEKEND. TODAY/S TEMPERATURES WILL LIKELY TO RISE WELL INTO THE 80S BY EARLY AFTERNOON...THANKS TO THE PREFRONTAL WARM AIR ADVECTION. HOWEVER FOR TOMORROW...ONGOING CLOUDS AND RAIN...AS WELL AS THE PULL OF COLDER AIR INTO THE REGION DURING NORMAL PEAK HEATING TIMES...WILL KEEP TEMPERATURES TOPPING OUT IN THE MID AND UPPER 60S. MUCH OF THE CWA HAS BEEN VERY WORKED OVER WITH RECENT HEAVY RAINS. IT WILL NOT TAKE MUCH TO CREATE AN EXCESS OF RUNOFF WITH ANY HEAVY RAIN SHOWER/THUNDERSTORM WE RECEIVE THROUGH FRIDAY AFTERNOON. MORE SO...THE FORECASTED PWATS AND POTENTIAL FOR HEAVY RAINFALL ARE HIGH...ESPECIALLY AS WE MOVE INTO FRIDAY. AS SUCH...WENT AHEAD AND EXPANDED THE WATCH ACROSS THE ENTIRE CWA...AS WELL AS EXTENDED IT UNTIL NOON FRIDAY WHEN THE HEAVIEST RAINFALL IS EXPECTED TO HAVE EXITED THE REGION AHEAD OF THE PASSING FRONTAL BOUNDARY. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 534 AM EDT THU APR 9 2015 THE MODELS ARE IN GOOD AGREEMENT WITH A FLATTER SPLIT FLOW PATTERN TO CONTROL ACROSS THE CONUS THROUGH EARLY NEXT WEEK...BEFORE BECOMING MORE AMPLIFIED TOWARDS THE END OF THE PERIOD. STUCK CLOSE TO A BLENDED SOLUTION...AS SMALLER SCALE DETAILS BECOME TOO DIFFICULT TO FORECAST WITH ANY CONFIDENCE. A COOLER AND LESS HUMID WEEKEND IS IN STORE FOR THE OHIO AND TENNESSEE VALLEYS. HIGHS WILL DROP BACK INTO THE 60S AND 70S FOR SATURDAY AND SUNDAY...WITH LOWS SUNDAY MORNING POSSIBLY DOWN INTO THE 30S FOR THE MORE SHELTERED VALLEYS. A NORTHERN STREAM SHORT WAVE TROUGH WILL MOVE FROM THE PLAINS TO THE GREAT LAKES SUNDAY INTO MONDAY...ALLOWING A COLD FRONT TO SHEAR OUT ACROSS THE OHIO VALLEY...RENEWING THE POP CHANCES. A SOUTHERN STREAM UPPER LEVEL LOW WILL ALSO BE MOVING NORTHEAST OUT OF THE DESERT SOUTHWEST...TRANSITIONING TO AN OPEN WAVE. THIS WILL USHER IN DEEPER MOISTURE BACK INTO EASTERN KENTUCKY...ALONG WITH PROVIDING SOME INTERACTION WITH THE LEFTOVER SURFACE FRONTAL BOUNDARY. DAILY CHANCES OF SHOWERS AND THUNDERSTORMS WILL CONTINUE WELL INTO NEXT WEEK. AGAIN...STUCK CLOSE TO A BLENDED SOLUTION...HOWEVER DID ALLOW FOR MORE OF A DIURNAL INFLUENCE ON THE POPS GIVEN THE UNCERTAINTY IN THE TIMING OF INDIVIDUAL FEATURES. HIGHS EACH DAY WILL AVERAGE IN THE LOW TO MID 70S...WITH LOWS IN THE LOW TO MID 50S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 656 AM EDT THU APR 9 2015 STRONG SRLY FLOW AND MOIST UNSTABLE AIR WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS TO THE REGION TODAY...ESPECIALLY DURING THE AFTERNOON AND EVENING. GIVEN THE UNCERTAINTY ON EXACTLY WHERE THESE STORMS WILL SET UP IN RELATION TO THE TAF SITE...KEPT WITH VCTS FROM PREVIOUS TAF. A FRONTAL BOUNDARY WILL BRING MORE WIDESPREAD CHANCES VERY LATE IN THE PERIOD...AFFECTING KSME...KLOZ...AND POSSIBLY KSME JUST BEFORE 6Z...THEN KJKL AND KSJS AROUND 6Z OR AFTER. ONCE AGAIN...UNTIL STORMS DEVELOP...EXACT IMPACTS ARE STILL UNCERTAIN...SO WENT WITH A GENERAL MVFR AT THIS TIME. WITH ANY OF THESE STORMS...ESPECIALLY IN THE AFTERNOON AND EVENING...STRONG TO DAMAGING WINDS...LARGE HAIL...AND HEAVY RAINS ARE A POSSIBILITY. && .JKL WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. && $$ UPDATE...JVM SHORT TERM...JMW LONG TERM...GEOGERIAN AVIATION...JMW
AREA FORECAST DISCUSSION
NWS JACKSON KY
945 AM EDT THU APR 9 2015 .UPDATE... ISSUED AT 945 AM EDT THU APR 9 2015 INCREASED POPS A BIT ACROSS OUR EXTREME NORTHERN COUNTIES THIS AFTERNOON AS THE LATEST HRRR RUN SHOWS SOME SCATTERED THUNDERSTORMS POPPING UP ACROSS THE NORTH. THE NAM12 IS A BIT MORE AGGRESSIVE WITH A LARGER AREA OF RAIN THIS AFTERNOON. THOUGH...STILL HAVE UNCERTAINTY AS TO WHERE THE STORMS WILL SET UP AND MOVE SO HAVE LEFT MOSTLY CHANCE POPS IN THE GRIDS. ALSO UPDATED T AND TD GRIDS TO ALIGN WITH MOST RECENT OBS. SENT UPDATED GRIDS TO WEB SERVERS AND NDFD. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 411 AM EDT THU APR 9 2015 EASTERN KY CURRENTLY FINDS ITSELF IN A LULL...WITH EVENING SHOWERS AND THUNDERSTORMS HAVING EXITED TO THE EAST AND NORTHEAST. THE NEXT ROUND OF SHOWERS...CURRENTLY OVER FAR WESTERN KY...WILL BE IN RESPONSE TO AN APPROACHING LOW PRESSURE SYSTEM AND COLD FRONTAL BOUNDARY. AS WE HEAD INTO THE DAYLIGHT HOURS...EXPECT SOME ISOLATED TO SCATTERED CONVECTION TO POP UP ACROSS EASTERN KY DUE TO MOST WARM UNSTABLE AIR BEING PULLED IN FROM THE GULF OF MEXICO. HOWEVER...EXPECT MOST OF THE CONVECTION TO REMAIN TO OUR WEST AND NORTH CLOSER TO THE BOUNDARY. GIVEN THE UNSTABLE NATURE OF THE ATMOSPHERE...A NEARBY SOURCE OF LIFT IN THE BOUNDARY...AND SO MUCH MOISTURE AT PLAY...IT IS HIGHLY POSSIBLE THAT ANY THUNDERSTORMS WHICH DO DEVELOP COULD PUT DOWN SOME LOCALLY HEAVY TO TORRENTIAL RAINFALL...AS WELL AS PRODUCE LARGE HAIL AND DAMAGING WINDS. FOR ONCE...WE WILL HAVE A SHOT OF DECENT CAPE VALUES IN ADDITION TO SFC-6KM SHEAR OF 40 AND HIGHER BY THIS AFTERNOON...WHERE AS PREVIOUS EVENTS OF LATE HAVE BEEN LACKING ONE OR THE OTHER. THE COLD FRONT WILL SHIFT EASTWARD AND REACH WESTERN KY BY 06Z FRIDAY...AT WHICH POINT A BROAD AREA OF SHOWERS AND THUNDERSTORMS WILL HAVE ENCOMPASSED MUCH OF KENTUCKY. EXPECT AN AREA OF MORE WIDESPREAD COVERAGE TO MOVE INTO THE JKL CWA BY AROUND 6Z AND CONTINUE THROUGH FRIDAY MORNING AS THE FRONT CONTINUES TO APPROACH. GIVEN THE LATEST NAM12 FORECAST SOUNDINGS...IT LOOKS LIKE A LINE OF STORMS COULD DEVELOP...WITH HEAVY TO TORRENTIAL RAINS...AND STRONG TO DAMAGING WIND GUSTS MIXING DOWN AS IT RACES EASTWARD AHEAD OF THE FRONT. LATEST GFS40 FORECAST HAS THE COLD FRONT ENTERING INTO THE WESTERN PORTION OF THE CWA BY 12Z FRIDAY...AND EXITING TO THE EAST OF THE STATE AROUND 18Z. JUST BEHIND THE FRONTAL PASSAGE..MUCH DRIER W TO NW FLOW WILL TAKE HOLD...BRINGING A QUICK END TO ANY SHOWERS AND THUNDERSTORMS ACROSS THE REGION. IT WILL ALSO WORK TO QUICKLY COOL OFF TEMPERATURES QUITE QUICKLY...WITH MUCH LESS HUMIDITY EXPECTED AS WE GO INTO THE WEEKEND. TODAY/S TEMPERATURES WILL LIKELY TO RISE WELL INTO THE 80S BY EARLY AFTERNOON...THANKS TO THE PREFRONTAL WARM AIR ADVECTION. HOWEVER FOR TOMORROW...ONGOING CLOUDS AND RAIN...AS WELL AS THE PULL OF COLDER AIR INTO THE REGION DURING NORMAL PEAK HEATING TIMES...WILL KEEP TEMPERATURES TOPPING OUT IN THE MID AND UPPER 60S. MUCH OF THE CWA HAS BEEN VERY WORKED OVER WITH RECENT HEAVY RAINS. IT WILL NOT TAKE MUCH TO CREATE AN EXCESS OF RUNOFF WITH ANY HEAVY RAIN SHOWER/THUNDERSTORM WE RECEIVE THROUGH FRIDAY AFTERNOON. MORE SO...THE FORECASTED PWATS AND POTENTIAL FOR HEAVY RAINFALL ARE HIGH...ESPECIALLY AS WE MOVE INTO FRIDAY. AS SUCH...WENT AHEAD AND EXPANDED THE WATCH ACROSS THE ENTIRE CWA...AS WELL AS EXTENDED IT UNTIL NOON FRIDAY WHEN THE HEAVIEST RAINFALL IS EXPECTED TO HAVE EXITED THE REGION AHEAD OF THE PASSING FRONTAL BOUNDARY. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 534 AM EDT THU APR 9 2015 THE MODELS ARE IN GOOD AGREEMENT WITH A FLATTER SPLIT FLOW PATTERN TO CONTROL ACROSS THE CONUS THROUGH EARLY NEXT WEEK...BEFORE BECOMING MORE AMPLIFIED TOWARDS THE END OF THE PERIOD. STUCK CLOSE TO A BLENDED SOLUTION...AS SMALLER SCALE DETAILS BECOME TOO DIFFICULT TO FORECAST WITH ANY CONFIDENCE. A COOLER AND LESS HUMID WEEKEND IS IN STORE FOR THE OHIO AND TENNESSEE VALLEYS. HIGHS WILL DROP BACK INTO THE 60S AND 70S FOR SATURDAY AND SUNDAY...WITH LOWS SUNDAY MORNING POSSIBLY DOWN INTO THE 30S FOR THE MORE SHELTERED VALLEYS. A NORTHERN STREAM SHORT WAVE TROUGH WILL MOVE FROM THE PLAINS TO THE GREAT LAKES SUNDAY INTO MONDAY...ALLOWING A COLD FRONT TO SHEAR OUT ACROSS THE OHIO VALLEY...RENEWING THE POP CHANCES. A SOUTHERN STREAM UPPER LEVEL LOW WILL ALSO BE MOVING NORTHEAST OUT OF THE DESERT SOUTHWEST...TRANSITIONING TO AN OPEN WAVE. THIS WILL USHER IN DEEPER MOISTURE BACK INTO EASTERN KENTUCKY...ALONG WITH PROVIDING SOME INTERACTION WITH THE LEFTOVER SURFACE FRONTAL BOUNDARY. DAILY CHANCES OF SHOWERS AND THUNDERSTORMS WILL CONTINUE WELL INTO NEXT WEEK. AGAIN...STUCK CLOSE TO A BLENDED SOLUTION...HOWEVER DID ALLOW FOR MORE OF A DIURNAL INFLUENCE ON THE POPS GIVEN THE UNCERTAINTY IN THE TIMING OF INDIVIDUAL FEATURES. HIGHS EACH DAY WILL AVERAGE IN THE LOW TO MID 70S...WITH LOWS IN THE LOW TO MID 50S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 656 AM EDT THU APR 9 2015 STRONG SRLY FLOW AND MOIST UNSTABLE AIR WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS TO THE REGION TODAY...ESPECIALLY DURING THE AFTERNOON AND EVENING. GIVEN THE UNCERTAINTY ON EXACTLY WHERE THESE STORMS WILL SET UP IN RELATION TO THE TAF SITE...KEPT WITH VCTS FROM PREVIOUS TAF. A FRONTAL BOUNDARY WILL BRING MORE WIDESPREAD CHANCES VERY LATE IN THE PERIOD...AFFECTING KSME...KLOZ...AND POSSIBLY KSME JUST BEFORE 6Z...THEN KJKL AND KSJS AROUND 6Z OR AFTER. ONCE AGAIN...UNTIL STORMS DEVELOP...EXACT IMPACTS ARE STILL UNCERTAIN...SO WENT WITH A GENERAL MVFR AT THIS TIME. WITH ANY OF THESE STORMS...ESPECIALLY IN THE AFTERNOON AND EVENING...STRONG TO DAMAGING WINDS...LARGE HAIL...AND HEAVY RAINS ARE A POSSIBILITY. && .JKL WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. && $$ UPDATE...JVM SHORT TERM...JMW LONG TERM...GEOGERIAN AVIATION...JMW
AREA FORECAST DISCUSSION
NWS JACKSON KY
156 AM EDT THU APR 9 2015 .UPDATE... ISSUED AT 1208 AM EDT THU APR 9 2015 A FEW AREAS ACROSS THE REGION HAVE CLEARED OUT WITH CLOUD COVER AND WHERE THIS HAS OCCURRED...DENSE FOG IS BEGINNING TO DEVELOP. FOR NOW HAVE PUT THE MENTION OF FOG INTO THE ZONES AND THE HWO. A FEW SHOWERS AND THUNDERSTORMS CONTINUE TO LINGER ACROSS THE FORECAST AREA...ESPECIALLY IN THE SOUTH...WHERE INSTABILITY IS RELATIVELY UNTOUCHED. THIS ACTIVITY MAY CONTINUE INTO THE MORNING HOURS. IN THE NORTH...DECIDED TO KEEP THE FLOOD WATCH GOING AS A FEW SHOWERS CONTINUE TO MOVE THE AREA AND ACTIVITY OUT WEST MAY MAKE IT INTO THE AREA LATER TONIGHT. HAVE UPDATED THE GRIDS AND SENT THEM TO THE NDFD SERVERS AND HAVE ISSUED SOME FRESH ZONES. UPDATE ISSUED AT 750 PM EDT WED APR 8 2015 CURRENT CONDITIONS ACROSS THE AREA FEATURE A CLUSTER OF SHOWERS AND THUNDERSTORMS MOVING THROUGH THE NORTHERN PORTION OF EASTERN KENTUCKY. THIS HAS A BEEN AN AREA THAT HAS SEEN SOME HEAVY RAINFALL EARLY IN THE DAY AND WITH DEW POINTS STILL IN THE MID 60S AND CONVECTION MOVING IN...HAVE CONTINUED THE FLASH FLOOD WATCH AND HAVE ISSUED A FLASH FLOOD WARNING OVER THE NORTH. WITH THIS...HAVE SENT OUT AN UPDATE TO THE ZONES TO INCREASE THE POPS OVER THE NORTH AND BETTER REFLECT THE CURRENT RAINFALL MOVING THROUGH. THOUGH...WITH THIS ACTIVITY...WILL LIKELY SEE THIS COME TO AN END IN THE NEXT FEW HOURS AND HAVE DROPPED OFF POPS AFTER 05Z TONIGHT. HI RESOLUTION SHORT TERM MODELS INDICATE THAT THE CURRENT MCS WILL BE THE FINAL COMPLEX FOR THIS EVENING. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 455 PM EDT WED APR 8 2015 THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL SHOW SOUTHWEST FLOW OVER KENTUCKY WITH POCKETS OF ENERGY PASSING THROUGH THE REGION EVERY FEW HOURS. SOME HEIGHT FALLS WILL GET INTO THE MIX ON THURSDAY AS A LARGER TROUGH SWEETS EAST AND INTO THE UPPER MIDWEST. THE KEY TO THIS UNSETTLED PATTERN WILL BE THE SMALLER FEATURES THAT THE HIGHER RES MODELS...SUCH AS THE HRRR/NAM12...HAVE A BETTER CHANCE OF CATCHING. THAT BEING SAID...THE CONFIDENCE IS SOMEWHAT LOW GIVEN THE SMALL SCALE FEATURES AT PLAY. IN TERMS OF SENSIBLE WEATHER IT HAS BEEN QUITE AN ACTIVE DAY ACROSS EASTERN KENTUCKY SO FAR... WITH THE LAST PORTION OF THE MORNING CONVECTION NOW PUSHING OUT OF FAR EASTERN KENTUCKY. BUT THE BIG QUESTION IS...IS HOW THE CONVECTION NOW FORMING IN CENTRAL KENTUCKY WILL SOLIDIFY INTO A COMPLEX AND MOVE EWD... OR IF ADDITIONAL CONVECTION WILL FORM IN EASTERN KENTUCKY AND TRAIN. THE LATEST HRRR INDICATES MULTIPLE AREAS OF CONVECTION FORMING AND MOVING THROUGH OUR FORECAST AREA INTO TOMORROW MORNING....WHEREAS THE NAM12 DOESNT SHOW MUCH OF ANYTHING OVERNIGHT TONIGHT. BUT GIVEN THE CURRENT INSTABILITY PARAMETERS...CURRENT CONVECTION OUT IN CENTRAL KY... AND THE FACT THAT THE HRRR DID A GOOD JOB AT CAPTURING THE DAYTIME CONVECTION... HAVE HEDGED TOWARDS THE HRRR SOLUTION AND INCREASED TO LIKELY POPS IN THE GRIDS THROUGH 03Z. HAVE ALSO ISSUED A FLASH FLOOD WATCH THROUGH 15Z THURSDAY FOR THE THREAT OF TRAINING CONVECTION OVER OUR NORTHERN COUNTIES. THE SET UP FOR ADDITIONAL CONVECTION TOMORROW AFTERNOON INTO FRIDAY MORNING LOOKS SIMILAR TO TODAY...IF NOT BETTER...AS THE TROUGH APPROACHES FROM THE WEST. SO HAVE CONTINUED THE FAIRLY HIGH CHANCES FOR SHOWERS AND STORMS INTO LATE THURSDAY NIGHT/FRIDAY MORNING. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 521 PM EDT WED APR 8 2015 A COLD FRONT WILL BE PASSING SOUTHEAST THROUGH THE REGION AS THE PERIOD STARTS. SHOWERS AND THUNDERSTORMS WILL BE ONGOING AHEAD OF THE FRONT...BUT SHOULD COME TO AN ABRUPT END AFTER FROPA DURING THE DAY. SURFACE HIGH PRESSURE BUILDING IN BEHIND THE FRONT WILL THEN PROVIDE COOLER AND DRIER WEATHER THROUGH AT LEAST SUNDAY. AS THE HIGH SLIPS TO THE EAST...WARM AIR ADVECTION AND A WEAK WARM FRONT TRYING TO DEVELOP WILL PRESENT A LOW PROBABILITY OF SHOWERS SUNDAY NIGHT AND MONDAY. A FEW THUNDERSTORMS COULD SHOW UP ON MONDAY AFTERNOON. A BETTER CHANCE OF RAIN WILL ARRIVE MONDAY NIGHT AND TUESDAY AS A MID/UPPER LEVEL TROUGH PUSHES IN FROM THE WEST ALONG WITH THE FLOW OFF THE GULF. ONCE THIS IMPULSE LIFTS OUT...WE WILL REMAIN IN THE WARM SECTOR. WEAKER DISTURBANCES ALOFT MAY AID SHOWER/THUNDERSTORM DEVELOPMENT AT TIMES TUESDAY NIGHT AND WEDNESDAY...BUT THE TIMING WILL BE NONSPECIFIC AT THIS LONG RANGE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 155 AM EDT THU APR 9 2015 AFTER A ROUND OF SHOWERS AND THUNDERSTORMS MOVED THROUGH PORTIONS OF EASTERN KY THIS EVENING...CLEARING IS FINALLY STARTING TO TAKE PLACE. THERE IS SOME CONCERN TONIGHT ABOUT FOG DEVELOPMENT. GUIDANCE IS SHOWING NO FOG POTENTIAL. HOWEVER...WITH CLEARING SKIES AND SUCH A MOIST ENVIRONMENT...THE POTENTIAL IS DEFINITELY THERE...ESPECIALLY IN THE VALLEYS. IT/S JUST A MATTER OF IF THIS FOG WILL SET IN AT THE TAF SITES...AND IF IT DOES...FOR HOW LONG AND TO WHAT RESTRICTION. KEPT WITH IFR VIS AFTER 9Z...BUT WILL CONTINUE TO MONITOR FOG DEVELOPMENT IN CASE CHANGES NEED TO BE MADE. BY TOMORROW...OUR NEXT ROUND OF INSTABILITY WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS TO THE REGION...ESPECIALLY DURING THE AFTERNOON AND EVENING. GIVEN THE UNCERTAINTY ON EXACTLY WHERE THESE STORMS WILL SET UP IN RELATION TO THE TAF SITE...KEPT WITH VCTS FROM PREVIOUS TAF. A FRONTAL BOUNDARY WILL BRING MORE WIDESRPEAD CHANCES VERY LATE IN THE PERIOD...AFFECTING KSME...KLOZ...AND POSSIBLY KSME JUST BEFORE 6Z. && .JKL WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 11 AM EDT THIS MORNING FOR KYZ044- 050>052-104. && $$ UPDATE...SHALLENBERGER SHORT TERM...JVM/GREIF LONG TERM...HAL AVIATION...JMW
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1247 AM EDT Thu Apr 9 2015 ...Updated Aviation Discussion... ...Mesoscale Forecast Update... Issued at 830 PM EDT Wed Apr 8 2015 Strong to marginally severe convection across southern Indiana and much of central Kentucky is now pushing into the Bluegrass region. One renegade supercell near Owensboro weakened rapidly as it pushed eastward within the last hour, suggesting that our environment has been worked over, and observed temperatures are now in the upper 60s across most of the area. Warmer temps in south central Kentucky, but the environment is capped and the dynamical forcing aloft is also lacking. Will cut back on POPs as these storms exit the Bluegrass over the next hour or so, and work on canceling the Tornado Watch. The Flash Flood Watch is in effect and will be left in place, even though the flood threat won`t ramp up again until we get the next round of convection in sometime Thursday. .SHORT TERM (Now through Thursday Night)... Issued at 308 PM EDT Wed Apr 8 2015 ...More Strong Storms Possible This Evening and Tomorrow... Multiple boundaries have set up across the region this afternoon. SPC mesoanalysis shows all the CIN from earlier in the day has eroded and we have become moderately unstable with 2500-3500 J/kg CAPE. A Severe Thunderstorm Watch has been issued for southern Indiana for this afternoon and early evening. However, given the multiple boundaries and possibility for strong storms elsewhere around the forecast area, extensions to the Watch are not out of the question this afternoon. Large hail and damaging winds will be the main threats this afternoon, though a tornado or two cannot be ruled out completely. The other concern for tonight will be the possibility of training thunderstorms, particularly across southern IN and north central KY. The latest runs of the HRRR have been suggesting this. Given that flash flood values are under an inch an hour and storms may train in this area, have gone ahead and issued a Flash Flood Watch starting late this afternoon and continuing through tomorrow night. There should be a relative lull in the storms for much of the overnight period as any storms that develop this afternoon will move out late this evening. Think another complex associated with a weak upper level wave will move in early tomorrow morning and continue through the morning hours. Some small hail and gusty winds will be possible with these storms. There should be at least a short break in storm coverage tomorrow afternoon ahead of the more significant chance for severe weather along and ahead of the cold front tomorrow night. Moisture will pool ahead of the front with strong southerly winds through the afternoon tomorrow. Forcing will come from the upper level trough moving in and an upper level jet. Shear will increase and hodographs exhibit favorable clockwise curving tomorrow night. A broken line of showers and thunderstorms looks to develop to our west congeal into a line as it moves into the forecast area tomorrow evening. Damaging winds will be the the main threat with the squall line, with a few embedded tornadoes possible. If any cells do develop ahead of the main line hail could be a threat as well. Due to the repeated areas of convection moving across the region, have kept the Flash Flood Watch in place through tomorrow night. Repeated rains will only exacerbate or renew flooding problems. .LONG TERM (Friday through Wednesday)... Issued at 241 PM EDT Wed Apr 8 2015 Not much has changed in the thinking for the long term period. Due to the ongoing storms an updated discussion will not be issued this afternoon. The previous discussion is below. Previous discussion ------------------- Cold front should pass through the area during the pre-dawn hours Friday in our west then sweep across the rest of central Kentucky during the early morning hours. Westerly flow will bring in a drier and quieter pattern Friday night. Plan on a pleasant, sunny and seasonable Saturday with high pressure over the lower Ohio Valley. Sunday will start off in similar fashion but as the high quickly moves to the east, southerly return flow will begin to push another slug of warm, moist air to the region. Shower chances return Sunday night through Monday as a trough digs across the central Plains. High-end chance to likely POPs look reasonable early next week with near normal temperatures. && .AVIATION (06Z TAF Update)... Updated at 1245 AM EDT Thu Apr 9 2015 Plan on VFR conditions the remainder of the overnight as air mass across central Kentucky has been worked over by earlier convection and is largely stable. A complex of showers/storms currently across Illinois may try to dip southeastward toward SDF/LEX by 11-13z. Confidence isn`t high as meso-models are showing this could end up staying to the north. Will keep mention in the TAFs for now. Increasing pressure gradient ahead of the next system will result in strong southerly winds later today at all sites. Plan on sustained winds 15-20 kts with gusts 25 to locally 30 kts. Timing the new few waves of convection is tricky but it looks like a pre-frontal system could spark a round of thunderstorms late this afternoon through early evening (22-03z) then a brief break before the main cold front passes 06-09z Friday. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...FLASH FLOOD WATCH through late tonight FOR KYZ023>025-028>043- 045>049-053>057-066-067. IN...FLASH FLOOD WATCH through late tonight FOR INZ076>079-083-084- 089>092. && $$ Mesoscale.........RAS Short Term........EER Long Term.........BJS Aviation..........ZT
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1015 PM CDT FRI APR 10 2015 .UPDATE... THINGS HAVE SETTLED DOWN THIS EVENING AFTER A RATHER EVENTFUL DAY AT LEAST AROUND SOUTH LAKE CHARLES. A FUNNEL CLOUD DEVELOPED EARLY THIS AFTN NEAR THE LC REGIONAL AIRPORT AND LASTED SEVERAL MINUTES BEFORE DISSIPATING...FOLLOWED ABOUT AN HOUR LATER BY TORRENTIAL RAINFALL THAT PRODUCED FLOODING ACRS SOUTH LAKE CHARLES. THESE STORMS PRODUCED OVER 3 INCHES OF RAIN IN ONE HOUR...AND JUST OVER 4 INCHES TOTAL WHICH SET A NEW RECORD FOR RAINFALL. AS FOR TONIGHT...THE COLD FRONT HAS SETTLED NEAR OR JUST OFF THE SW LA COAST...AND IS EXPECTED TO REMAIN THERE THROUGH SAT MORNING BEFORE LIFTING BACK NORTH DURING THE AFTN. WITH DIURNAL INSTABILITY DIMINISHING AND THE FIRST OF SEVERAL DISTURBANCES EXITING TO THE EAST...MUCH OF THE CONVECTION HAS DISSIPATED WITH JUST A FEW SHOWERS OVER THE COASTAL WATERS. ADJUSTED EVENING AND OVERNIGHT POPS DOWN SLIGHTLY TO REFLECT THE LATEST RADAR TRENDS AND HRRR GUIDANCE. ALSO TWEAKED HOURLY TEMPS...DEWPOINTS AND WINDS...BUT NOTHING TOO SIGNIFICANT. SHOWERS AND THUNDERSTORMS WILL INCREASE AGAIN DURING THE DAY SATURDAY AS THE FRONT LIFTS NORTH AND THE NEXT PIECE OF SHORTWAVE ENERGY CROSSES THE REGION. 24 && .PREV DISCUSSION... /ISSUED 614 PM CDT FRI APR 10 2015/ AVIATION...LIGHT RAIN AND A FEW THUNDERSTORMS WILL CONTINUE TO AFFECT THE I-10 CORRIDOR AND SOUTHWARD THROUGH THE NEXT FEW HOURS. ALONG WITH THE RAIN, MVFR AND IFR CEILINGS WILL BE COMMON THROUGH TONIGHT AND INTO SATURDAY MORNING. CEILINGS WILL GRADUALLY LIFT TOWARD LATE MORNING SAT, HOWEVER RAIN AND THUNDERSTORMS WILL REDEVELOP IN THE AFTERNOON. VRB WINDS EARLY THIS EVENING WILL BECOME NE TONIGHT AS A WEAK FRONT PUSHES INTO THE GULF. 05 PREV DISCUSSION... /ISSUED 427 PM CDT FRI APR 10 2015/ DISCUSSION... OBSERVATIONAL DATA SUGGEST THE CDFNT HAS NEARLY CLEARED THE INLAND FCST AREA...THOUGH A LARGE SWATH OF LIGHT TO MODERATE RAIN WITH EMBEDDED HEAVIER SHOWERS CONTINUES ACROSS MUCH OF SE TX/SW LA. THE BACK EDGE OF THIS PCPN SHIELD LOOKS TO BE GETTING CLOSE TO THE HOUSTON AREA. LATEST SHORT TERM PROGS SUGGEST THE RAINFALL ACTIVITY WILL LINGER INTO THE EVENING HOURS...ALBEIT WITH BOTH COVERAGE AND INTENSITY DECLINING WITH THE LOSS OF DIURNAL INSTABILITY AND THE EASTWARD DEPARTURE OF A SHORTWAVE TROF. THE FRONT IS EXPECTED TO CONTINUE INTO THE COASTAL WATERS THIS EVENING...WITH A BRIEF REPRIEVE IN RAINFALL EXPECTED OVERNIGHT AND INTO SATURDAY MORNING. RAIN CHANCES RETURN BY THE AFTERNOON...HOWEVER...WITH THE FRONT PROGGED TO RETREAT BACK TO THE NORTH AS ANOTHER WEAK SHORTWAVE TROF EJECTS OUT ACROSS CENTRAL/EASTERN TX. PWATS ARE AGAIN FCST TO REACH NEAR 1.7 INCHES...WHICH WILL YIELD CONVECTION CAPABLE OF HIGH RAINFALL RATES. ELEVATED RAIN CHANCES WILL CONTINUE SUNDAY AND ON INTO MONDAY AMID THIS VERY MOIST AIRMASS...AS ADDITIONAL SPOKES OF ENERGY LIFT OUT AHEAD OF AN UPPER LOW PROGGED TO SLOWLY ADVANCE THROUGH THE DESERT SW AND INTO CENTRAL TX...AND ANOTHER SFC FRONT PUSHES INTO THE REGION. HIGHEST RAIN CHANCES SHIFT MORE TWD THE EAST ON TUE ALONG AND AHEAD OF THE FRONT AND AMID SLIGHTLY DRIER AIR PUSHING IN FROM THE WEST. AT LEAST LOW POPS CONTINUE WED AND THU...HOWEVER...UNTIL A MORE POTENT FRONT SWEEPS THROUGH THU NIGHT INTO EARLY FRI. HIGH TEMPERATURES THROUGH THE PERIOD ARE GENERALLY EXPECTED TO BE NEAR OR ABOVE SEASONAL NORMALS...WITH LOWS WELL ABOVE NORMAL. 13 MARINE... A COLD FRONT WILL CONTINUE TO ADVANCE INTO THE NEAR COASTAL WATERS AND STALL THIS EVENING. THIS FRONT WILL BRING A CHANCE FOR A FEW SHOWERS AND THUNDERSTORMS. THIS ACTIVITY WILL CONTINUE INTO SATURDAY AS THE BOUNDARY LIFTS BACK NORTH AS WARM FRONT...WITH A SOUTHERLY FLOW RETURNING BY SATURDAY AFTERNOON. UPPER LEVEL DISTURBANCES MOVING ACROSS THE AREA WILL THEN KEEP A DAILY CHANCE FOR SHOWERS AND THUNDERSTORMS CONTINUING THROUGH MID-WEEK. 13 && .PRELIMINARY POINT TEMPS/POPS... AEX 55 79 64 76 / 10 30 40 80 LCH 62 79 67 78 / 30 60 60 60 LFT 64 80 67 80 / 40 60 50 70 BPT 64 78 68 78 / 20 60 60 70 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
645 PM EDT THU APR 9 2015 .SYNOPSIS... A WARM FRONT WILL SLOWLY LIFT NORTHWARD THROUGH VIRGINIA TONIGHT INTO FRIDAY MORNING. A STRONG COLD FRONT CROSSES THE AREA LATE FRIDAY...WITH HIGH PRESSURE BUILDING BACK INTO THE REGION OVER THE WEEKEND. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... LATEST SFC ANALYSIS REVEALS HIGH PRESSURE RIDGING DOWN THE MID ATLANTIC COAST WITH A STALLED FRONTAL BNDRY OVER INTERIOR NC. A STRONG SFC LOW IS CENTERED OVER THE MIDWEST STATES...WHILE A POTENT MID-LEVEL SHORTWAVE TROF IS OVER THE CENTRAL PLAINS. ONGOING CONVECTION REMAINS TO THE SOUTH OF THE STALLED BOUNDARY (WARM FRONT) EARLY THIS EVENING AND THUS WILL CARRY ONLY LIMITED POPS AREAWIDE THRU 10 PM OR SO. LATEST HRRR HINTS THAT CONVECTION OVER CENTRAL NC WILL MOVE NE INTO OUR FA LATE THIS EVENING AND OVERNIGHT AS THE WARM FRONT STARTS TO LIFT BACK NORTH...AND HAVE ADJUSTED POPS ACCORDINGLY TO SHOW HIGH CHC/LIKELY POPS THRU THE CENTER OF OUR FA. LOWEST POPS (~20%) WILL BE ACROSS SOUTHSIDE HAMPTON ROADS AND COASTAL NE NC. WILL CARRY SLIGHT CHC TSTMS AS WELL WITH LIMITED INSTABILITY. TEMPS WILL TEND TO HOLD STEADY THIS EVENING AND OVERNIGHT BEFORE RISING PRIOR TO SUNRISE FROM NORTH TO SOUTH WITH THE WARM FROPA. LOWS IN THE LOW 40S EASTERN SHORE TO NR 60 FAR SOUTH. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/... THE AFOREMENTIONED MID-LEVEL TROUGH AND ATTENDANT SURFACE LOW OVER THE GREAT LAKES WILL LIFT INTO ONTARIO ON FRIDAY...SHUNTING A SFC COLD FRONT IN OUR DIRECTION LATE FRIDAY INTO FRIDAY NIGHT. THE LOCAL AREA REMAINS IN A MOIST AIRMASS W/SURFACE DEWPOINTS IN THE 60S...PRECIPITABLE WATER VALUES ~+2SD...INCREASING LLVL STEERING FLOW AND MUCAPE IN THE 1000-1500 J/KG RANGE. THIS WILL LIKELY BE SUFFICIENT FOR CONVECTIVE DEVELOPMENT FRIDAY AFTERNOON AND EVENING ACROSS THE REGION. SPC CONTINUES TO OUTLOOK THE REGION IN A SLIGHT RISK OF SEVERE STORMS WITH LARGE HAIL/DMGG WINDS THE PRIMARY HAZARDS. THE TIMING OF THE SEVERE THREAT LOOKS TO BE LATE AFTERNOON THROUGH EVENING AS THE FRONT PUSHES ACROSS THE AREA. MAIN CHANGE TO PREVIOUS FORECAST WAS TO INCREASE POPS TO 70% AND DELAY TIMING OF PRECIP A COUPLE HRS AS MOST GUIDANCE HAS SLOWED DOWN THE SYSTM JUST A BIT...MAKING MUCH OF THE DAY THRU 18Z DRY FOR ALL OF THE FA EXCEPT FAR WRN AREAS. QUITE WARM AS WELL...WITH HIGHS IN THE LO TO MID 80S ALONG THE COASTAL PLAIN...UPR 70S TO LWR 80S OTHER AREAS. THE COLD FRONT SLIDES OFFSHORE BY SAT MORNG. HIGH PRESSURE BUILDING IN BEHIND THE FRONT WILL BRING A PLEASANT WEEKEND TO THE FA WITH HIGHS BOTH DAYS IN THE UPR 60S TO LWR 70S UNDER A MSTLY SUNNY SKY. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... THE LONG TERM PERIOD BEGINS WITH HIGH PRESSURE OVER THE REGION WITH DRY CONDITIONS AND SEASONABLE TEMPERATURES THROUGH MONDAY. THE MODELS AND IN GOOD AGREEMENT ON THE THE SURFACE HIGH SLOWLY SLIDING OFF THE COAST ON MONDAY WITH THE APPROACH OF A WEAK COLD FRONT MONDAY NIGHT INTO TUESDAY MORNING. THE 12 ECMWF HAS MORE MOISTURE WITH THAN THE PREVIOUS RUN AND LOOKS MORE LIKE THE GFS. THE 12Z GFS IS A TOUCH SLOWER WITH THE FRONT..BUT STILL SHOWS GOOD LIFT AND MOISTURE SO HAVE KEPT THE CHANCE POPS FOR LATE MONDAY NIGHT INTO THE DAY ON TUESDAY. STILL WOULD EXPECT QPF TO BE ON THE LOW SIDE AS THE BULK OF THE MOISTURE IS STILL OVER THE GULF COAST STATES IN ADVANCE OF THE NEXT SYSTEM. BY TUESDAY EVENING...SHOULD SEE THE FRONT PUSH INTO SC/GA WITH HIGH PRESSURE SAGGING DOWN THE EASTERN SEABOARD. THE GFS AND ECMWF SHOW A LOT LESS MOISTURE FOR WEDNESDAY INTO THURSDAY THAN PREVIOUS RUNS...SO HAVE STARTED TO LOWER POPS DOWN TO SLIGHT CHANCE LEVELS NOW FOR MOST OF THE AREA...BUT WOULD NOT BE SURPRISED TO SEE A DRY DAY ON WEDNESDAY. THE UNCERTAINTY COMES ON THURSDAY AS THE FLOW ALOFT BECOMES MORE SOUTHWEST AND WITH A DEVELOPING TROUGH OVER THE SOUTHERN PLAINS...SHOULD SEE GULF MOISTURE BEGINNING TO ADVECT BACK INTO THE REGION. HAVE MAINTAINED THE CHANCE POPS FOR NOW AS TIMING MAY BE A QUESTION...BUT EXPECT TO SEE A DECENT RAINFALL EVENT LATE NEXT WEEK AS WAVES OF ENERGY LIFT NE AROUND THE DEVELOPING TROUGH. FOR TEMPERATURES...HAVE GENERALLY RUN CLOSE TO THE SUPERBLEND GUIDANCE WITH HIGHS GENERALLY IN THE 70S MOST OF THE WEEK...ALTHOUGH DID LOWER VALUES A TOUCH ON WEDNESDAY BEHIND THE FRONT...SO WOULD NOT BE SURPRISED TO SEE HIGH MORE IN THE MID TO UPPER 60S ON WEDNESDAY AND POSSIBLY THURSDAY IF WEDGING SETS UP WITH OVERRUNING CLOUDS. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... AS OF 17Z...NE TO E WINDS WERE KEEPING A MOIST MARINE LAYER AT THE SURFACE WITH GENERALLY IFR CIGS. ORF AND ECG WILL BE INTERMITTENTLY MVFR AND POSSIBLY SBY (NOT IN THE TAF) AS WELL. FOLLOWED CONSISTENCY OF THE MOS AND BROUGHT CONDS DOWN TO LIFR/VLIFR OVERNIGHT. S/SW WINDS DEVELOP FRIDAY MORNING AHEAD OF THE NEXT FRONT WHICH WILL SLOWLY SCOUR OUT THE LOW LEVEL MOISTURE. SW WINDS MAY BE GUSTY (AROUND 25 KTS) AT TIMES AFT 15Z. SCT TSTMS...SOME STRONG...MAY IMPACT THE TAF SITES LATE FRIDAY AFTN/EVENING. VFR AND DRY WEATHER WILL PREVAIL SATURDAY THROUGH MONDAY WITH HIGH PRESSURE BUILDING INTO THE REGION. THERE WILL BE A CHANCE FOR SHOWERS ON TUESDAY. && .MARINE... STILL SEEING THE INFLUENCE OF THE HIGH PRESSURE SYSTEM OVER THE NERN US NOSING DOWN INTO THE COASTAL WATERS THIS AFTERNOON. WIND ARE GENERALLY 10 TO 15 KT OUT OF THE E TO NE. THIS IS SERVING TO KEEPING THE COAST WATERS STILL IN THE 5 TO 7 FT RANGE FOR THE NORTHERN 2 COASTAL ZONES...SO HAVE KEPT SCA ON GOING. THIS HIGH WILL PULL OUT OF THE AREA TONIGHT AND THE FLOW WILL TURN SOUTHERLY IN ADVANCE OF A COLD FRONT WHICH MOVES THROUGH ON FRIDAY. IN ADVANCE OF THE FRONT WILL SEE WINDS KICK UP TO AROUND 15 TO 20 KT. THE WINDS ALOFT WILL BE STRONGER...BUT THE COOLER WATER WILL SERVE TO KEEP THE HIGHER WINDS OFF THE WATER SURFACE. SOME THUNDERSTORMS ARE EXPECTED WITH THIS FRONT AND THESE STORMS COULD BRIEFLY BRING THE STRONGER WINDS DOWN TO THE SURFACE. ONCE THE WINDS TURN NW BEHIND THE FRONT SHOULD SLOWLY SEE THE WINDS DIMINISH LATER FRIDAY NIGHT BACK TO 10 TO 15 KT. SO FOR NOW HAVE EXTEND THE SCA THROUGH 1 AM FRIDAY FOR SEAS OF 5 TO 7 FT. HIGH PRESSURE BUILDS INTO THE REGION ON SATURDAY AND LINGERS THROUGH MONDAY. THIS SHOULD BRING A PERIOD OF QUIET WEATHER WITH THE WINDS DIMINISHING ON SUNDAY TO UNDER 10 KT. THE NEXT FRONT TO IMPACT THE WATERS ARRIVES ON MONDAY NIGHT AS A COLD FRONT SWINGS ACROSS THE AREA. EXPECT AN INCREASE IN SW WINDS ON MONDAY AHEAD OF THE FRONT...BUT SHOULD REMAIN BELOW SCA LEVELS AGAIN IN THE 15 TO 20 KT RANGE. HIGH PRESSURE RETURNS FOR THE WEDNESDAY AND THURSDAY TIME PERIOD WITH ANOTHER PERIOD OF QUIET WEATHER. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EDT SATURDAY FOR ANZ650-652. && $$ SYNOPSIS...JDM NEAR TERM...JDM SHORT TERM...MAS/MAM LONG TERM...ESS AVIATION...LSA MARINE...ESS
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
212 PM EDT THU APR 9 2015 .SYNOPSIS... A BACKDOOR COLD FRONT OVER NORTHEAST NORTH CAROLINA WILL CONTINUE TO WEAKEN TODAY...THEN LIFT BACK NORTH THROUGH VIRGINIA AS A WARM FRONT THIS AFTERNOON INTO TONIGHT. ANOTHER COLD FRONT CROSSES THE REGION LATE FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... LATEST WX ANALYSIS FEATURES COLD FRONT IN PLACE SOUTH OF THE LOCAL AREA THIS MORNING. CONTINUE TO NOTE SOME VERY LIGHT RAIN/DZ AND FOG ACROSS FAR NORTHERN ZONES, WITH MORE WIDESPREAD AREA OF SHOWERS AND EMBEDDED TSTMS CURRENTLY PUSHING SLOWLY TO THE E-SE FROM THE PIEDMONT INTO CENTRAL VA FOLLOWING WEAK STEERING FLOW JUST NORTH OF THE FRONTAL ZONE. HAVE CONTINUED TO NOTE ELEVATED INSTABILITY IN THIS AREA ATOP A STABLE/SATURATED BL. THE HRRR HAS HANDLED THIS (AND PREVIOUS) ROUND OF CONVECTION QUITE WELL AND HAVE HEDGED THE FORECAST IN ITS DIRECTION FOR THE FIRST PART OF THE NEAR TERM. WILL TAKE CURRENT SWATH OF CONVECTION ACROSS CENTRAL ZONES THROUGH 08-09Z...BEFORE IT TRANSITIONS ACROSS SE VA AND OFFSHORE BY 15Z. WITH PW VALUES WELL ABOVE CLIMO AVG (~2SD), SOME BRIEF HEAVY DOWNPOURS REMAIN POSSIBLE THIS MORNING. OTHERWISE, AS WITH YESTERDAY, GIVEN STABLE BL AND LITTLE IF ANY TANGIBLE IMMINENT FORCING MECHANISM UPSTREAM, WILL GO WITH A RELATIVE LULL IN PCPN AND A MAINLY DRY ALBEIT MAINLY OVERCAST AFTERNOON. GIVEN MOIST AIRMASS, WILL STICK WITH A SLIGHT CHC OF SHRAS FOR THE AFTN. LOOK FOR HIGHS IN THE MID TO UPPER 50S ACROSS THE NORTH, LOW TO MID 60S CENTRAL ZONES, AND U60S TO MID 70S ALONG AND SOUTH OF US 58 CORRIDOR OF SOUTHERN VA/INTERIOR NE NC. LOW PRESSURE OVER THE PLAINS WILL TRACK NE INTO THE UPPER MIDWEST LATE TODAY INTO EARLY FRIDAY. RESULTANT DEVELOPING WEAK RIDGING ALLOWS SW FLOW TO DEVELOP, WHICH WILL SHUNT WEAK FRONTAL ZONE BACK NORTH BY LATE IN THE DAY. WHILE MOST OF THE AREA WILL REMAIN IN THE STABLE/EASTERLY FLOW TODAY, EXPECT MILDER TEMPERATURES BY AFTN ACROSS SOUTHERN TIER OF THE CWA AS FRONT BEGINS TO LIFT BACK NORTH LATE TDA/TNGT. CONTINUED MILD ACROSS THE SOUTH TONIGHT, WITH LOWS IN THE U50S TO L60S SOUTH, LOW TO MID 50S NORTH. && .SHORT TERM /FRIDAY THROUGH SATURDAY/... THE AFOREMENTIONED UPPER TROUGH AND ATTENDANT SURFACE LOW OVER THE GREAT LAKES WILL LIFT INTO ONTARIO ON FRIDAY, SHUNTING SFC COLD FRONT IN OUR DIRECTION FRIDAY INTO FRIDAY NIGHT. LOCAL AREA REMAINS IN A MOIST AIRMASS W/SURFACE DEWPOINTS IN THE 60S...PRECIPITABLE WATER VALUES ~+2SD AND INCREASING LLVL STEERING FLOW AND MUCAPE IN THE 1000-1500 J/KG RANGE WILL LIKELY BE SUFFICIENT FOR CONVECTIVE DEVELOPMENT FRIDAY AFTERNOON AND EVENING ACROSS THE REGION. SHOULD BE NOTED THAT THE HIGHER END OF INSTABILITY PROFILES ABOVE 2K J/KG HAVE BEEN DISCOUNTED FOR NOW GIVEN PREFRONTAL CLOUDS AND UNCERTAINTY OF SHRA COVERAGE EARLY FRI MORNING. SPC CONTINUES TO OUTLOOK THE REGION IN A SLIGHT RISK OF SEVERE STORMS WITH LARGE HAIL/DMGG WINDS THE PRIMARY HAZARDS. THE PRIMARY TIMING OF THE SEVERE THREAT LOOKS TO BE LATE AFTERNOON THROUGH FRI EVENING AS THE FRONT PUSHES ACROSS THE AREA. PREVIOUS FORECAST DEPICTING CHC POPS RAMPING INTO LIKELY RANGE DURING THIS PERIOD HAS BEEN RETAINED, WITH RAIN CHCS DROPPING OFF QUICKLY FROM NORTHWEST TO SOUTHEAST FRIDAY NIGHT. QUITE WARM ON FRIDAY WITH A FULL DAY OF COMPRESSIONAL HEATING ON WARM SOUTHERLY FLOW. LOOK FOR HIGHS IN THE MID 80S ALONG THE COASTAL PLAIN, UPPER 70S TO AROUND 80 INLAND. COLD FRONT SLIDES OFFSHORE TO BEGIN THE DAY SAT. HIGH PRESSURE BUILDING IN BEHIND THE FRONT WILL BRING A PLEASANT START TO THE WEEKEND WITH HIGHS IN THE U60S NORTH TO LOW 70S SOUTH UNDER A MOSTLY SUNNY SKY. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... HIGH PRESSURE PROGGED TO LOCATE OVER THE REGION SUN...RESULTING IN DRY CONDITIONS AND MOSTLY SUNNY SKIES. LIGHT ONSHORE FLOW WILL RESULT IN TEMPS IN THE UPPER 60S INLAND TO LOW-MID 60S COASTAL AREAS. HIGH PRESSURE PUSHES OFFSHORE MON...RESULTING IN RETURN FLOW OVER MUCH OF THE SE AND MID-ATLANTIC REGIONS. HIGHS MODERATE MON...WARMING INTO THE LOW 70S INLAND AND LOW-MID 60S COASTAL AREAS. FLOW ALOFT ALSO PROGGED TO AMPLIFY MON AS SRN STREAM ENERGY LIFTS FROM THE SRN PLAINS INTO THE MIDWEST...AND HIGH PRESSURE ALOFT AMPLIFIES OVER THE SE STATES. ASSOCIATED SFC LOW LIFTS INTO THE MIDWEST MON AFTERNOON...WITH A STATIONARY BOUNDARY EXTENDING EWD INTO THE SE STATES. RAINFALL CHANCES RAMP UP OVER THE GULF STATES AND TN/KY VALLEYS MON NIGHT...INTO THE OH VALLEY TUES. MAINTAINED SLIGHT CHANCE-CHANCE POPS ACROSS THE REGION BEGINNING TUES MORNING TO ACCOUNT FOR INCREASING MOISTURE AND WEAK PERTURBATIONS IN THE SWLY FLOW. SFC LOW PROGGED TO LIFT INTO THE UPPER MIDWEST TUES...WITH HIGH PRESSURE REMAINING OVER THE WRN ATLANTIC. HAVE LOWERED POPS TUES AFTERNOON AS BEST CHANCES FOR MEASURABLE PRECIP FORECAST TO BE OVER THE OH VALLEY (CLOSET TO BEST DYNAMICS/MOISTURE)...BUT WILL KEEP LOW-END CHANCE POPS ACROSS THE REGION. HIGHS TUES IN THE LOW-MID 70S INLAND TO MID-UPPER 60S COASTAL AREAS. SWLY FLOW PERSISTS WEDS...RESULTING IN WARM/BUT PARTLY CLOUDY-MOSTLY CLOUDY SKIES. WILL CONTINUE WITH SLIGHT CHANCE TO CHANCE POPS WEDS. HIGHS WEDS FORECAST IN THE MID 70S INLAND TO MID-UPPER 60S COASTAL AREAS. MILD LOWS MON NIGHT-WEDS NIGHT DUE TO RETURN FLOW AND CLOUD COVER. LOWS GENERALLY IN THE MID 50S. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... AS OF 17Z...NE TO E WINDS WERE KEEPING A MOIST MARINE LAYER AT THE SURFACE WITH GENERALLY IFR CIGS. ORF AND ECG WILL BE INTERMITTENTLY MVFR AND POSSIBLY SBY (NOT IN THE TAF) AS WELL. FOLLOWED CONSISTENCY OF THE MOS AND BROUGHT CONDS DOWN TO LIFR/VLIFR OVERNIGHT. S/SW WINDS DEVELOP FRIDAY MORNING AHEAD OF THE NEXT FRONT WHICH WILL SLOWLY SCOUR OUT THE LOW LEVEL MOISTURE. SW WINDS MAY BE GUSTY (AROUND 25 KTS) AT TIMES AFT 15Z. SCT TSTMS...SOME STRONG...MAY IMPACT THE TAF SITES LATE FRIDAY AFTN/EVENING. VFR AND DRY WEATHER WILL PREVAIL SATURDAY THROUGH MONDAY WITH HIGH PRESSURE BUILDING INTO THE REGION. THERE WILL BE A CHANCE FOR SHOWERS ON TUESDAY. && .MARINE... THUNDERSTORMS WILL CROSS THE WATERS THIS MORNING AND THEN COME TO AN END ACROSS SRN COASTAL WATERS BY MID TO LATE MORNING. OTHERWISE...A FRONT THAT CROSSED THE WATERS ON WED WILL REMAIN STALLED ACROSS THE CAROLINAS TODAY. PERSISTENT N-NE WINDS AOB 15KT HAVE KEPT SEAS ELEVATED BTWN 4-7FT FROM FENWICK ISLAND TO THE VA/NC BORDER. SEAS WILL SLOWLY SUBSIDE BELOW 5FT FOR COASTAL WATERS SOUTH OF PARRAMORE ISLAND BY THIS AFTN...AND REMAIN AROUND 5FT CLOSER TO 20NM FOR NRN COASTAL WATERS TODAY THROUGH MOST OF FRIDAY BEFORE FALLING BELOW 5FT/SCA THRESHOLDS. THE STALLED FRONT LIFTS NWD AS A WARM FRONT TONIGHT INTO EARLY FRI MORNING. WINDS TONIGHT WILL BEGIN E-SE AOB 15KT AND THEN BECOME MORE SLY BEHIND THE WARM FRONT (15-20KT COASTAL WATERS...AOB 15KT BAY/RIVERS/SOUND). SPEEDS BEGIN TO INCREASE AROUND SUNRISE FRI MORNING AND WILL CONTINUE TO BE BREEZY DURING THE DAY AHEAD OF AN APPROACHING COLD FRONT. WINDS WILL AVERAGE 15-20KT WITH GUSTS OF 25- 30KT DURING THE AFTN. SEAS WILL AVERAGE 3-4FT TONIGHT INTO FRI MORNING AND THEN BUILD TWD 5FT FROM PARRAMORE ISLAND TO CAPE CHARLES LIGHT BY MID-LATE FRI MORNING. WAVES 2-3FT TONIGHT WILL THEN AVERAGE 3FT ON FRI. THE COLD FRONT CROSSES THE WATERS FRI NIGHT WITH STRONG THUNDERSTORMS EXPECTED. MAIN IMPACTS WILL BE GUSTY AND ERRATIC THUNDERSTORM WINDS WITH HEAVY RAINFALL. MARINERS SHOULD BE AWARE OF RAPIDLY CHANGING CONDITIONS AND PLAN FOR A QUICK ROUTE TO SAFE HARBOR WHEN NEEDED LATE FRI AFTN/EVENING. BEHIND THE COLD FRONT FRI NIGHT...A COOLER AIRMASS DOES NOT ARRIVE UNTIL DURING THE DAY ON SAT. A DAYTIME ARRIVAL OF THE COOLER AIR WILL DECREASE CHANCES FOR POST-FRONTAL SCA WINDS. EXPECT W-N WINDS ON SAT AOB 15KT...DECREASING TO AOB 10KT SAT NIGHT AS HIGH PRESSURE BUILDS INTO THE REGION FROM THE WEST AND SETTLES OVER THE WATERS ON SUN/SUN NIGHT. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ650-652. && $$ SYNOPSIS...MAM NEAR TERM...MAM SHORT TERM...MAS/MAM LONG TERM...SAM AVIATION...LSA MARINE...BMD
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
423 AM EDT THU APR 9 2015 .SYNOPSIS... A BACKDOOR COLD FRONT OVER NORTHEAST NORTH CAROLINA WILL CONTINUE TO WEAKEN TODAY...THEN LIFT BACK NORTH THROUGH VIRGINIA AS A WARM FRONT THIS AFTERNOON INTO TONIGHT. ANOTHER COLD FRONT CROSSES THE REGION LATE FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... LATEST WX ANALYSIS FEATURES COLD FRONT IN PLACE SOUTH OF THE LOCAL AREA THIS MORNING. CONTINUE TO NOTE SOME VERY LIGHT RAIN/DZ AND FOG ACROSS FAR NORTHERN ZONES, WITH MORE WIDESPREAD AREA OF SHOWERS AND EMBEDDED TSTMS CURRENTLY PUSHING SLOWLY TO THE E-SE FROM THE PIEDMONT INTO CENTRAL VA FOLLOWING WEAK STEERING FLOW JUST NORTH OF THE FRONTAL ZONE. HAVE CONTINUED TO NOTE ELEVATED INSTABILITY IN THIS AREA ATOP A STABLE/SATURATED BL. THE HRRR HAS HANDLED THIS (AND PREVIOUS) ROUND OF CONVECTION QUITE WELL AND HAVE HEDGED THE FORECAST IN ITS DIRECTION FOR THE FIRST PART OF THE NEAR TERM. WILL TAKE CURRENT SWATH OF CONVECTION ACROSS CENTRAL ZONES THROUGH 08-09Z...BEFORE IT TRANSITIONS ACROSS SE VA AND OFFSHORE BY 15Z. WITH PW VALUES WELL ABOVE CLIMO AVG (~2SD), SOME BRIEF HEAVY DOWNPOURS REMAIN POSSIBLE THIS MORNING. OTHERWISE, AS WITH YESTERDAY, GIVEN STABLE BL AND LITTLE IF ANY TANGIBLE IMMINENT FORCING MECHANISM UPSTREAM, WILL GO WITH A RELATIVE LULL IN PCPN AND A MAINLY DRY ALBEIT MAINLY OVERCAST AFTERNOON. GIVEN MOIST AIRMASS, WILL STICK WITH A SLIGHT CHC OF SHRAS FOR THE AFTN. LOOK FOR HIGHS IN THE MID TO UPPER 50S ACROSS THE NORTH, LOW TO MID 60S CENTRAL ZONES, AND U60S TO MID 70S ALONG AND SOUTH OF US 58 CORRIDOR OF SOUTHERN VA/INTERIOR NE NC. LOW PRESSURE OVER THE PLAINS WILL TRACK NE INTO THE UPPER MIDWEST LATE TODAY INTO EARLY FRIDAY. RESULTANT DEVELOPING WEAK RIDGING ALLOWS SW FLOW TO DEVELOP, WHICH WILL SHUNT WEAK FRONTAL ZONE BACK NORTH BY LATE IN THE DAY. WHILE MOST OF THE AREA WILL REMAIN IN THE STABLE/EASTERLY FLOW TODAY, EXPECT MILDER TEMPERATURES BY AFTN ACROSS SOUTHERN TIER OF THE CWA AS FRONT BEGINS TO LIFT BACK NORTH LATE TDA/TNGT. CONTINUED MILD ACROSS THE SOUTH TONIGHT, WITH LOWS IN THE U50S TO L60S SOUTH, LOW TO MID 50S NORTH. && .SHORT TERM /FRIDAY THROUGH SATURDAY/... THE AFOREMENTIONED UPPER TROUGH AND ATTENDANT SURFACE LOW OVER THE GREAT LAKES WILL LIFT INTO ONTARIO ON FRIDAY, SHUNTING SFC COLD FRONT IN OUR DIRECTION FRIDAY INTO FRIDAY NIGHT. LOCAL AREA REMAINS IN A MOIST AIRMASS W/SURFACE DEWPOINTS IN THE 60S...PRECIPITABLE WATER VALUES ~+2SD AND INCREASING LLVL STEERING FLOW AND MUCAPE IN THE 1000-1500 J/KG RANGE WILL LIKELY BE SUFFICIENT FOR CONVECTIVE DEVELOPMENT FRIDAY AFTERNOON AND EVENING ACROSS THE REGION. SHOULD BE NOTED THAT THE HIGHER END OF INSTABILITY PROFILES ABOVE 2K J/KG HAVE BEEN DISCOUNTED FOR NOW GIVEN PREFRONTAL CLOUDS AND UNCERTAINTY OF SHRA COVERAGE EARLY FRI MORNING. SPC CONTINUES TO OUTLOOK THE REGION IN A SLIGHT RISK OF SEVERE STORMS WITH LARGE HAIL/DMGG WINDS THE PRIMARY HAZARDS. THE PRIMARY TIMING OF THE SEVERE THREAT LOOKS TO BE LATE AFTERNOON THROUGH FRI EVENING AS THE FRONT PUSHES ACROSS THE AREA. PREVIOUS FORECAST DEPICTING CHC POPS RAMPING INTO LIKELY RANGE DURING THIS PERIOD HAS BEEN RETAINED, WITH RAIN CHCS DROPPING OFF QUICKLY FROM NORTHWEST TO SOUTHEAST FRIDAY NIGHT. QUITE WARM ON FRIDAY WITH A FULL DAY OF COMPRESSIONAL HEATING ON WARM SOUTHERLY FLOW. LOOK FOR HIGHS IN THE MID 80S ALONG THE COASTAL PLAIN, UPPER 70S TO AROUND 80 INLAND. COLD FRONT SLIDES OFFSHORE TO BEGIN THE DAY SAT. HIGH PRESSURE BUILDING IN BEHIND THE FRONT WILL BRING A PLEASANT START TO THE WEEKEND WITH HIGHS IN THE U60S NORTH TO LOW 70S SOUTH UNDER A MOSTLY SUNNY SKY. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... HIGH PRESSURE PROGGED TO LOCATE OVER THE REGION SUN...RESULTING IN DRY CONDITIONS AND MOSTLY SUNNY SKIES. LIGHT ONSHORE FLOW WILL RESULT IN TEMPS IN THE UPPER 60S INLAND TO LOW-MID 60S COASTAL AREAS. HIGH PRESSURE PUSHES OFFSHORE MON...RESULTING IN RETURN FLOW OVER MUCH OF THE SE AND MID-ATLANTIC REGIONS. HIGHS MODERATE MON...WARMING INTO THE LOW 70S INLAND AND LOW-MID 60S COASTAL AREAS. FLOW ALOFT ALSO PROGGED TO AMPLIFY MON AS SRN STREAM ENERGY LIFTS FROM THE SRN PLAINS INTO THE MIDWEST...AND HIGH PRESSURE ALOFT AMPLIFIES OVER THE SE STATES. ASSOCIATED SFC LOW LIFTS INTO THE MIDWEST MON AFTERNOON...WITH A STATIONARY BOUNDARY EXTENDING EWD INTO THE SE STATES. RAINFALL CHANCES RAMP UP OVER THE GULF STATES AND TN/KY VALLEYS MON NIGHT...INTO THE OH VALLEY TUES. MAINTAINED SLIGHT CHANCE-CHANCE POPS ACROSS THE REGION BEGINNING TUES MORNING TO ACCOUNT FOR INCREASING MOISTURE AND WEAK PERTURBATIONS IN THE SWLY FLOW. SFC LOW PROGGED TO LIFT INTO THE UPPER MIDWEST TUES...WITH HIGH PRESSURE REMAINING OVER THE WRN ATLANTIC. HAVE LOWERED POPS TUES AFTERNOON AS BEST CHANCES FOR MEASURABLE PRECIP FORECAST TO BE OVER THE OH VALLEY (CLOSET TO BEST DYNAMICS/MOISTURE)...BUT WILL KEEP LOW-END CHANCE POPS ACROSS THE REGION. HIGHS TUES IN THE LOW-MID 70S INLAND TO MID-UPPER 60S COASTAL AREAS. SWLY FLOW PERSISTS WEDS...RESULTING IN WARM/BUT PARTLY CLOUDY-MOSTLY CLOUDY SKIES. WILL CONTINUE WITH SLIGHT CHANCE TO CHANCE POPS WEDS. HIGHS WEDS FORECAST IN THE MID 70S INLAND TO MID-UPPER 60S COASTAL AREAS. MILD LOWS MON NIGHT-WEDS NIGHT DUE TO RETURN FLOW AND CLOUD COVER. LOWS GENERALLY IN THE MID 50S. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... FIRST ROUND OF THUNDERSTORMS ARE NOW WELL SOUTH OF THE AREA... ALONG WITH THE FRONT THAT DROPPED SOUTH ACROSS THE REGION WED EVENING. A SECOND WAVE OF DISSIPATING MCS ENERGY IS MOVING INTO THE REGION FROM THE WEST EARLY THIS MORNING...BRINGING ANOTHER ROUND OF THUNDERSTORMS THROUGH THE AREA THROUGH AT LEAST MID MORNING (09/1500Z) BEFORE COMING TO AN END. MAIN IMPACTS WILL BE ERRATIC WIND GUSTS AROUND 30KT...FREQUENT LIGHTNING...AND PERIODS OF MODERATE TO HEAVY RAINFALL. ALL TAF SITES WILL BE IMPACTED BY THE AFOREMENTIONED THUNDERSTORM CONDITIONS IN ADDITION TO LIFR CEILINGS AND BR/FG. ONCE PRECIP COMES TO AN END LATER THIS MORNING...CONDITIONS WILL BE SLOW TO IMPROVE THURSDAY AFTERNOON AS THE FRONT TO THE SOUTH LIFTS NORTH ACROSS THE REGION AS A WARM FRONT THURSDAY NIGHT. OVERNIGHT SHOWERS ARE POSSIBLE ONCE AGAIN AS PLENTY OF MOISTURE STREAMS INTO THE AREA FROM THE SOUTHWEST AND INTERACTS WITH THE WARM FRONT. BREEZY S-SW WINDS WITH GUSTS OF 20-30KT SHOULD ALSO BE ANTICIPATED LATE FRIDAY MORNING INTO THE AFTERNOON AHEAD OF AN APPROACHING COLD FRONT. THE FRONT CROSSES THE AREA FRIDAY AFTN/EVENING AND THE CHANCES FOR STRONG THUNDERSTORMS INCREASES. RAPIDLY DETERIORATING CONDITIONS DUE TO STRONG GUSTY THUNDERSTORM WINDS AND HEAVY RAINFALL WILL IMPACT ALL TAF SITES DURING THIS TIME. THE FRONT AND ALL PRECIPITATION MOVE OFF THE COAST BY SATURDAY MORNING...FOLLOWED BY HIGH PRESSURE DURING THE REMAINDER OF THE WEEKEND. && .MARINE... THUNDERSTORMS WILL CROSS THE WATERS THIS MORNING AND THEN COME TO AN END ACROSS SRN COASTAL WATERS BY MID TO LATE MORNING. OTHERWISE...A FRONT THAT CROSSED THE WATERS ON WED WILL REMAIN STALLED ACROSS THE CAROLINAS TODAY. PERSISTENT N-NE WINDS AOB 15KT HAVE KEPT SEAS ELEVATED BTWN 4-7FT FROM FENWICK ISLAND TO THE VA/NC BORDER. SEAS WILL SLOWLY SUBSIDE BELOW 5FT FOR COASTAL WATERS SOUTH OF PARRAMORE ISLAND BY THIS AFTN...AND REMAIN AROUND 5FT CLOSER TO 20NM FOR NRN COASTAL WATERS TODAY THROUGH MOST OF FRIDAY BEFORE FALLING BELOW 5FT/SCA THRESHOLDS. THE STALLED FRONT LIFTS NWD AS A WARM FRONT TONIGHT INTO EARLY FRI MORNING. WINDS TONIGHT WILL BEGIN E-SE AOB 15KT AND THEN BECOME MORE SLY BEHIND THE WARM FRONT (15-20KT COASTAL WATERS...AOB 15KT BAY/RIVERS/SOUND). SPEEDS BEGIN TO INCREASE AROUND SUNRISE FRI MORNING AND WILL CONTINUE TO BE BREEZY DURING THE DAY AHEAD OF AN APPROACHING COLD FRONT. WINDS WILL AVERAGE 15-20KT WITH GUSTS OF 25- 30KT DURING THE AFTN. SEAS WILL AVERAGE 3-4FT TONIGHT INTO FRI MORNING AND THEN BUILD TWD 5FT FROM PARRAMORE ISLAND TO CAPE CHARLES LIGHT BY MID-LATE FRI MORNING. WAVES 2-3FT TONIGHT WILL THEN AVERAGE 3FT ON FRI. THE COLD FRONT CROSSES THE WATERS FRI NIGHT WITH STRONG THUNDERSTORMS EXPECTED. MAIN IMPACTS WILL BE GUSTY AND ERRATIC THUNDERSTORM WINDS WITH HEAVY RAINFALL. MARINERS SHOULD BE AWARE OF RAPIDLY CHANGING CONDITIONS AND PLAN FOR A QUICK ROUTE TO SAFE HARBOR WHEN NEEDED LATE FRI AFTN/EVENING. BEHIND THE COLD FRONT FRI NIGHT...A COOLER AIRMASS DOES NOT ARRIVE UNTIL DURING THE DAY ON SAT. A DAYTIME ARRIVAL OF THE COOLER AIR WILL DECREASE CHANCES FOR POST-FRONTAL SCA WINDS. EXPECT W-N WINDS ON SAT AOB 15KT...DECREASING TO AOB 10KT SAT NIGHT AS HIGH PRESSURE BUILDS INTO THE REGION FROM THE WEST AND SETTLES OVER THE WATERS ON SUN/SUN NIGHT. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ654. SMALL CRAFT ADVISORY UNTIL 7 AM EDT THIS MORNING FOR ANZ656. SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ650-652. && $$ SYNOPSIS...MAM NEAR TERM...MAM SHORT TERM...MAS/MAM LONG TERM...SAM AVIATION...BMD MARINE...BMD
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
208 AM EDT THU APR 9 2015 .SYNOPSIS... A BACKDOOR COLD FRONT OVER NORTHEAST NORTH CAROLINA WILL CONTINUE TO WEAKEN OVERNIGHT...THEN LIFT BACK NORTH THROUGH VIRGINIA AS A WARM FRONT THURSDAY INTO THURSDAY NIGHT. ANOTHER COLD FRONT CROSSES THE REGION LATE FRIDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... WHAT`S LEFT OF A DECAYING OH VLY MCS WAS MOVING THROUGH NE NC AS OF 10 PM. THIS BATCH OF SHOWERS AND SUB-SEVERE THUNDERSTORMS WILL MOVE OUT OF THE AREA BETWEEN MIDNIGHT-1AM. OTW...A BACKDOOR COLD FRONT SITS JUST SOUTH OF THE FA AND SHOULD REMAIN STATIONARY OVERNIGHT. THIS WILL ALLOW LOW OVERCAST CONDITIONS TO CONTINUE OVERNIGHT WITH SFC HIGH PRESSURE RIDGING DOWN INTO THE LOCAL AREA FROM THE NORTHEAST. THE NEXT BATCH OF PCPN IS MAKING ITS WAY THROUGH THE OH VLY LATE THIS EVENING AND IS SHOWN BY THE LATEST HRRR TO MAKE A RUN AT THE FA BY AROUND 08-09Z...THEN MOVING SE THRU 15Z. THE HRRR DID A GOOD JOB HANDLING THE MCS THIS EVENING SO WILL LEAN TOWARD ITS SOLUTION OVERNIGHT AND HAVE ADJUSTED POPS ACCORDINGLY. LOWS TONIGHT FROM NR 40 MD EASTERN SHORE TO THE LOW/MID 50S SW. && .SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/... THE FRONT WILL WEAKEN...WITH DEVELOPING SW FLOW EVENTUALLY PUSHING IT BACK NWD AS A WARM FRONT BY LATE THU. HIGHS THU WILL RANGE FROM THE 50S ON THE LWR ERN SHORE TO THE U60S TO M70S WITH MORE TIME IN THE WARM SECTOR ACROSS SRN/WRN AREAS. POPS REMAIN IN THE CHANCE RANGE AS SEVERAL WEAK DISTURBANCES WILL RESULT IN PERIODS FOR SCT SHRAS...AND ISOLTD TSTMS ESPECIALLY OVER SRN/WRN AREAS. THE SFC LOW OVER THE PLAINS WILL TRACK NE INTO THE GREAT LAKES LATE THU/FRI WITH THE ASSOCIATED COLD FRONT CROSSING INTO OUR AREA FM THE WEST LATE IN THE DAY ON FRI/FRI NGT. CHANCES OF ADDITIONAL SHRAS/TSTMS INCREASE FM W TO E THRU THE DAY FRI...WITH THE BEST CHANCE (60% POPS) IN THE AFTN/EVE HRS. SOME TSTMS MAY HAVE STRONG GUSTY WINDS...HAIL AND HEAVY RAIN...AND HV MAINTAINED THIS MENTION IN THE HWO. MORE SUN/COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL ALLOW FOR MUCH WARMER TEMPS ON FRIDAY COMPARED TO PREVIOUS DAYS AS THE ENTIRE FA RETURNS INTO THE WARM SECTOR. LOOK FOR HIGHS IN THE MID 70S TO LOW 80S...WITH SOME MID 80S POSSIBLE ACROSS SE AREAS. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... HIGH PRESSURE PROGGED TO LOCATE OVER THE REGION SUN...RESULTING IN DRY CONDITIONS AND MOSTLY SUNNY SKIES. LIGHT ONSHORE FLOW WILL RESULT IN TEMPS IN THE UPPER 60S INLAND TO LOW-MID 60S COASTAL AREAS. HIGH PRESSURE PUSHES OFFSHORE MON...RESULTING IN RETURN FLOW OVER MUCH OF THE SE AND MID-ATLANTIC REGIONS. HIGHS MODERATE MON...WARMING INTO THE LOW 70S INLAND AND LOW-MID 60S COASTAL AREAS. FLOW ALOFT ALSO PROGGED TO AMPLIFY MON AS SRN STREAM ENERGY LIFTS FROM THE SRN PLAINS INTO THE MIDWEST...AND HIGH PRESSURE ALOFT AMPLIFIES OVER THE SE STATES. ASSOCIATED SFC LOW LIFTS INTO THE MIDWEST MON AFTERNOON...WITH A STATIONARY BOUNDARY EXTENDING EWD INTO THE SE STATES. RAINFALL CHANCES RAMP UP OVER THE GULF STATES AND TN/KY VALLEYS MON NIGHT...INTO THE OH VALLEY TUES. MAINTAINED SLIGHT CHANCE-CHANCE POPS ACROSS THE REGION BEGINNING TUES MORNING TO ACCOUNT FOR INCREASING MOISTURE AND WEAK PERTURBATIONS IN THE SWLY FLOW. SFC LOW PROGGED TO LIFT INTO THE UPPER MIDWEST TUES...WITH HIGH PRESSURE REMAINING OVER THE WRN ATLANTIC. HAVE LOWERED POPS TUES AFTERNOON AS BEST CHANCES FOR MEASURABLE PRECIP FORECAST TO BE OVER THE OH VALLEY (CLOSET TO BEST DYNAMICS/MOISTURE)...BUT WILL KEEP LOW-END CHANCE POPS ACROSS THE REGION. HIGHS TUES IN THE LOW-MID 70S INLAND TO MID-UPPER 60S COASTAL AREAS. SWLY FLOW PERSISTS WEDS...RESULTING IN WARM/BUT PARTLY CLOUDY-MOSTLY CLOUDY SKIES. WILL CONTINUE WITH SLIGHT CHANCE TO CHANCE POPS WEDS. HIGHS WEDS FORECAST IN THE MID 70S INLAND TO MID-UPPER 60S COASTAL AREAS. MILD LOWS MON NIGHT-WEDS NIGHT DUE TO RETURN FLOW AND CLOUD COVER. LOWS GENERALLY IN THE MID 50S. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... FIRST ROUND OF THUNDERSTORMS ARE NOW WELL SOUTH OF THE AREA... ALONG WITH THE FRONT THAT DROPPED SOUTH ACROSS THE REGION WED EVENING. A SECOND WAVE OF DISSIPATING MCS ENERGY IS MOVING INTO THE REGION FROM THE WEST EARLY THIS MORNING...BRINGING ANOTHER ROUND OF THUNDERSTORMS THROUGH THE AREA THROUGH AT LEAST MID MORNING (09/1500Z) BEFORE COMING TO AN END. MAIN IMPACTS WILL BE ERRATIC WIND GUSTS AROUND 30KT...FREQUENT LIGHTNING...AND PERIODS OF MODERATE TO HEAVY RAINFALL. ALL TAF SITES WILL BE IMPACTED BY THE AFOREMENTIONED THUNDERSTORM CONDITIONS IN ADDITION TO LIFR CEILINGS AND BR/FG. ONCE PRECIP COMES TO AN END LATER THIS MORNING...CONDITIONS WILL BE SLOW TO IMPROVE THURSDAY AFTERNOON AS THE FRONT TO THE SOUTH LIFTS NORTH ACROSS THE REGION AS A WARM FRONT THURSDAY NIGHT. OVERNIGHT SHOWERS ARE POSSIBLE ONCE AGAIN AS PLENTY OF MOISTURE STREAMS INTO THE AREA FROM THE SOUTHWEST AND INTERACTS WITH THE WARM FRONT. BREEZY S-SW WINDS WITH GUSTS OF 20-30KT SHOULD ALSO BE ANTICIPATED LATE FRIDAY MORNING INTO THE AFTERNOON AHEAD OF AN APPROACHING COLD FRONT. THE FRONT CROSSES THE AREA FRIDAY AFTN/EVENING AND THE CHANCES FOR STRONG THUNDERSTORMS INCREASES. RAPIDLY DETERIORATING CONDITIONS DUE TO STRONG GUSTY THUNDERSTORM WINDS AND HEAVY RAINFALL WILL IMPACT ALL TAF SITES DURING THIS TIME. THE FRONT AND ALL PRECIPITATION MOVE OFF THE COAST BY SATURDAY MORNING...FOLLOWED BY HIGH PRESSURE DURING THE REMAINDER OF THE WEEKEND. && .MARINE... UPDATE...COASTAL WATERS FROM CAPE CHARLES LIGHT TO THE VA/NC BORDER ADDED TO SCA FLAGS THROUGH 700 AM THIS MORNING DUE TO SEAS OF 4-5 FT. BACKDOOR COLD FRONT HAS LOCATED JUST SOUTH AND WEST OF THE WATER THIS AFTERNOON. THE RESULT IS N-NE FLOW...AVG 10-15 KT. STRONGER GRADIENT EXISTS OVER THE NRN COASTAL WATERS...WHERE A FEW GUSTS 25- 28 KT OBSERVED. SEAS HAVE BUILT TO 6-8 FT OVER THE NRN COASTAL ZONES...GENERALLY NORTH OF PARRAMORE ISLAND. FARTHER SOUTH...SEAS AVG 2-4 FT. SCA HEADLINES REMAIN IN EFFECT NORTH OF CAPE CHARLES LIGHT FOR SEAS. GRADIENT WINDS EXPECTED TO DIMINISH TONIGHT AOB 15 KT...BUT SEAS WILL REMAIN ELEVATED (4-7 FT) AS NE FLOW PERSISTS. BACKDOOR FRONT REMAINS JUST SOUTH AND WEST OF THE WATER THURS...SLOWLY LIFTING BACK NWD. FLOW BECOMES MORE ONSHORE...E-NE GENERALLY 10-15 KT. SEAS REMAIN 4-6 FT NORTH OF PARRAMORE ISLAND...DROPPING BELOW 5 FT SOUTH. BACKDOOR FRONT LIFTS NORTH OF THE WATER FINALLY THURS NIGHT-FRI MORNING AS A WARM FRONT. FLOW BECOMES SLY...INCREASING TO AROUND 15 KT RIVERS/BAY/SOUND AND 20 KT COASTAL WATERS. MARGINAL SCA CONDITIONS ARE POSSIBLE FRI AFTERNOON AS THE GRADIENT STRENGTHENS IN ADVANCE OF AN APPROACHING COLD FRONT. WILL HOLD OFF ON HEADLINES DUE TO 4TH PERIOD AND BEING MARGINAL ATTM. COLD FRONT CROSSES THE WATERS FRI NIGHT...WITH FLOW BECOMING NWLY POST FRONTAL. BEST CAA REMAINS NORTH OF THE LOCAL AREA...BUT A FEW GUSTS TO 20 KT POSSIBLE IN THE BAY AND 25 KT COASTAL WATERS BRIEFLY LATE FRI NIGHT-EARLY SAT MORNING. SEAS BUILD TO 4-6 FT FRI NIGHT. HIGH PRESSURE BUILDS OVER THE WATERS THIS WEEKEND...RESULTING IN SUB-SCA CONDITIONS. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ654. SMALL CRAFT ADVISORY UNTIL 7 AM EDT THIS MORNING FOR ANZ656. SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ650-652. && $$ SYNOPSIS...MAS NEAR TERM...JDM/MAS SHORT TERM...MAS/MAM LONG TERM...SAM AVIATION...BMD MARINE...BMD/SAM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
534 PM EDT THU APR 9 2015 LATEST UPDATE... HYDRO .SYNOPSIS... ISSUED AT 330 PM EDT THU APR 9 2015 STRENGTHENING LOW PRESSURE PASSING JUST WEST OF MICHIGAN WILL BRING THE POTENTIAL FOR SEVERE THUNDERSTORMS THIS EVENING FOLLOWED BY RATHER WINDY CONDITIONS ON FRIDAY. HIGH PRESSURE WILL PROVIDE A PLEASANT WEEKEND. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 330 PM EDT THU APR 9 2015 POTENTIAL FOR DAMAGING THUNDERSTORM WINDS AND PERHAPS EVEN A FEW TORNADOES WILL INCREASE LATER THIS AFTERNOON AND ESPECIALLY THIS EVENING... MAINLY ALONG/SOUTH OF I-96. THE THREAT WILL END SHORTLY AFTER MIDNIGHT. WARM UNSTABLE AIR MASS TO OUR SOUTHWEST IS EXPECTED TO SURGE INTO THE AREA AFTER 5 PM NOW THAT THE POTENT SHORTWAVE OVR KS/NE IS EJECTING NORTHEAST. THIS FEATURE TAKES ON A NEGATIVE TILT AS IT MOVES TOWARD WISCONSIN LATER THIS EVENING... LEADING TO A DEEPENING OF THE SFC LOW AS IT MOVES TOWARD THE MILWAUKEE AREA. THIS SYNOPTIC SET UP WITH A STRONG WARM FRONT/TRIPLE POINT EXTENDING EAST OF THE DEEPENING SFC LOW LEADS TO STRONG CONCERNS FOR ROTATING CELLS AND SPIN UPS NEAR THE WARM FRONT THIS EVENING AS IT MOVES INTO SWRN LWR MI... DUE TO HIGH LOW LEVEL SHEAR VALUES AND POTENTIALLY AVAILABLE UPDRAFT HELICITY. TORNADO WATCHES ARE ALREADY IN EFFECT JUST UPSTREAM OF SW LWR MI AND THE LATEST WATCH... 41... HAS A MEAN STORM MOTION VECTOR OF 240 DEGREES AT 40 KTS. IT SEEMS REASONABLE AT THIS POINT TO BELIEVE WE WILL SEE SFC BASED CAPES OF 1000-1500 J/KG ARRIVING FROM THE SOUTHWEST TOWARD 00Z BASED ON LATEST RUC GUIDANCE AND MESOANALYSIS TO OUR SW. THE OTHER CONCERN THIS EVENING IS FOR LINES/BOWS TO DEVELOP IN THE UPSTREAM TORNADO WATCH AREAS AND RACE RAPIDLY EAST/NORTHEAST ACROSS PARTS OF SW MI. THESE FEATURES COULD PRODUCE DAMAGING STRAIGHT LINE WIND GUSTS AHEAD OF THE COLD FRONT. ALTHOUGH ANY STRONG/SEVERE CONVECTION WILL END AFTER MIDNIGHT WITH THE PASSAGE OF THE SFC COLD FRONT... STRONG SYNOPTIC WIND GUSTS BEHIND THE FRONT DUE TO CONTINUED DEEPENING OF THE SFC LOW OVR NRN LWR MI WILL LEAD TO SOME GUSTS TO 50 MPH OVERNIGHT INTO FRIDAY. CONVECTIVE SHOWERS WITH HIGH CLOUD BASES UNDER THE UPPER LOW ON FRIDAY COULD HELP PROMOTE STRONG GUSTS AS WELL. WILL ISSUE A WIND ADVISORY FOR LATE TONIGHT AND FRIDAY. THINGS QUIET DOWN CONSIDERABLY FRIDAY NIGHT AS HIGH PRESSURE BUILDS IN. .LONG TERM...(SUNDAY THROUGH THURSDAY) ISSUED AT 330 PM EDT THU APR 9 2015 WARMER THAN NORMAL WEATHER FOR A CHANGE FROM SUNDAY AT LEAST INTO WEDNESDAY OF NEXT WEEK. STILL A CHANCE OF A WET STRETCH ON WEDNESDAY OR THURSDAY BUT TIMING IS REALLY UNCERTAIN. OVERALL PATTER IS SOMEWHAT PROGRESSIVE WITH GOOD NWP AGREEMENT ON WEST COAST TROF AND EAST COAST RIDGE DEVELOPING EARLY NEXT WEEK. SUCH A PATTERN WILL PROVIDE THE WARMTH WITH POSITIVE H85 TEMPS THROUGHOUT NEXT WEEK. AFTER MID 60S ON SUNDAY A COLD FRONT WILL PUSH THROUGH MONDAY MORNING. THINKING IT WILL LIKELY COOL MONDAY BY JUST A FEW DEGREES OVER SUNDAY AS THE UPSTREAM HIGH IS WEAK AND THERE IS JUST NOT MUCH OF A PUSH OF COLD AIR. THERE WILL BE SOME DECENT MOISTURE ADVECTION ALONG AND AHEAD OF THE FRONT SUNDAY EVENING SO STILL THINKING SCT SHOWERS ARE A GOOD BET WITH THE FRONTAL PASSAGE ITSELF. IN ANY CASE IT SHOULD BE A QUICK HITTER AND AT LEAST THE LATTER HALF OF MONDAY WILL BE DRY AND SEASONABLE. AFTER THAT THERE IS MUCH DISAGREEMENT ON HOW PROGRESSIVE WEST COAST TROF WILL BE AND HOW MUCH AND WHEN WILL A SOUTHERN STREAM SHORTWAVE EJECT NORTHEAST TOWARDS THE MISSISSIPPI VALLEY AND THEN GREAT LAKES. EACH OF THE PAST FEW DAYS THE GFS/ECM HAVE BEEN DELAYING THE SYSTEM BY A DAY...YESTERDAY THE SIGNAL WAS FOR A WEDNESDAY EVENT WHILE TODAY IT IS NOW LOOKING LIKE A THURSDAY EVENT. BASICALLY...THE POTENTIAL HIS SMEARED OUT IN THE FORECAST WITH CHANCE POPS FOR TUE NIGHT INTO THURSDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 156 PM EDT THU APR 9 2015 WIDESPREAD IFR/LIFR WILL IMPROVE TO MVFR/VFR BY EARLY EVENING AS WARM FRONT PUSHES NORTHWARD. STILL LOOKING AT SEVERAL HOURS OF SHOWER AND THUNDERSTORM ACTIVITY THROUGH MID EVENING...A FEW STORMS COULD PRODUCE DAMAGING WINDS AND HAIL BETWEEN 22Z-04Z THIS EVENING ALONG AND SOUTH OF ROUGHLY A KMKG-KGRR-KAMA LINE. EXPECTING SFC WIND GUSTS IN EXCESS OF 35 KTS FRIDAY MORNING WITH MODERATE CHOP BELOW 5KFT. WINDS WILL SLOWLY DIMINISH TOWARDS FRIDAY EVENING. THERE IS ALSO A CHANCE OF SOME LOW TOP CONVECTIVE SHOWERS WITH SMALL HAIL FRI AFTERNOON/EVENING BETWEEN 21Z - 03Z. && .MARINE... ISSUED AT 330 PM EDT THU APR 9 2015 WILL UPGRADE THE GALE WATCH TO A WARNING AS WINDS INCREASE DRAMATICALLY OUT OF THE WEST LATER TONIGHT BEHIND THE COLD FRONT. && .HYDROLOGY... ISSUED AT 534 PM EDT THU APR 9 2015 2 TO 3 INCHES OF RAIN HAS FALLEN IN THE PAST 15 HOURS IN PORTIONS OF OTTAWA... KENT... AND OCEANA COUNTIES. 1 TO 2 INCHES HAS FALLEN IN MANY LAKESHORE AND CENTRAL MICHIGAN COMMUNITIES... AND A QUARTER INCH TO 1 INCH IN SOUTHERN MICHIGAN. A FEW RIVERS HAVE BEGUN RISING. THE ROGUE BELOW ROCKFORD IS ALREADY ABOVE BANKFULL. SEVERAL OTHER RIVERS ARE FORECAST TO RISE ABOVE OR CLOSE TO BANKFULL. AS SUCH... RIVER FLOOD ADVISORIES HAVE BEEN ISSUED IN ADDITION TO THE AREAL FLOOD ADVISORY. RIVERS WILL BE CLOSELY MONITORED TONIGHT AS MORE RAINFALL IS EXPECTED. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...WIND ADVISORY FROM 2 AM TO 6 PM EDT FRIDAY FOR MIZ037>040- 043>046-050>052-056>059-064>067-071>074. LM...GALE WARNING FROM MIDNIGHT TONIGHT TO 2 PM EDT FRIDAY FOR LMZ844>849. && $$ SYNOPSIS...MEADE SHORT TERM...MEADE LONG TERM...COBB AVIATION...COBB HYDROLOGY...CAS MARINE...MEADE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
330 PM EDT THU APR 9 2015 LATEST UPDATE... SYNOPSIS/SHORT TERM/LONG TERM/MARINE .SYNOPSIS... ISSUED AT 330 PM EDT THU APR 9 2015 STRENGTHENING LOW PRESSURE PASSING JUST WEST OF MICHIGAN WILL BRING THE POTENTIAL FOR SEVERE THUNDERSTORMS THIS EVENING FOLLOWED BY RATHER WINDY CONDITIONS ON FRIDAY. HIGH PRESSURE WILL PROVIDE A PLEASANT WEEKEND. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 330 PM EDT THU APR 9 2015 POTENTIAL FOR DAMAGING THUNDERSTORM WINDS AND PERHAPS EVEN A FEW TORNADOES WILL INCREASE LATER THIS AFTERNOON AND ESPECIALLY THIS EVENING... MAINLY ALONG/SOUTH OF I-96. THE THREAT WILL END SHORTLY AFTER MIDNIGHT. WARM UNSTABLE AIR MASS TO OUR SOUTHWEST IS EXPECTED TO SURGE INTO THE AREA AFTER 5 PM NOW THAT THE POTENT SHORTWAVE OVR KS/NE IS EJECTING NORTHEAST. THIS FEATURE TAKES ON A NEGATIVE TILT AS IT MOVES TOWARD WISCONSIN LATER THIS EVENING... LEADING TO A DEEPENING OF THE SFC LOW AS IT MOVES TOWARD THE MILWAUKEE AREA. THIS SYNOPTIC SET UP WITH A STRONG WARM FRONT/TRIPLE POINT EXTENDING EAST OF THE DEEPENING SFC LOW LEADS TO STRONG CONCERNS FOR ROTATING CELLS AND SPIN UPS NEAR THE WARM FRONT THIS EVENING AS IT MOVES INTO SWRN LWR MI... DUE TO HIGH LOW LEVEL SHEAR VALUES AND POTENTIALLY AVAILABLE UPDRAFT HELICITY. TORNADO WATCHES ARE ALREADY IN EFFECT JUST UPSTREAM OF SW LWR MI AND THE LATEST WATCH... 41... HAS A MEAN STORM MOTION VECTOR OF 240 DEGREES AT 40 KTS. IT SEEMS REASONABLE AT THIS POINT TO BELIEVE WE WILL SEE SFC BASED CAPES OF 1000-1500 J/KG ARRIVING FROM THE SOUTHWEST TOWARD 00Z BASED ON LATEST RUC GUIDANCE AND MESOANALYSIS TO OUR SW. THE OTHER CONCERN THIS EVENING IS FOR LINES/BOWS TO DEVELOP IN THE UPSTREAM TORNADO WATCH AREAS AND RACE RAPIDLY EAST/NORTHEAST ACROSS PARTS OF SW MI. THESE FEATURES COULD PRODUCE DAMAGING STRAIGHT LINE WIND GUSTS AHEAD OF THE COLD FRONT. ALTHOUGH ANY STRONG/SEVERE CONVECTION WILL END AFTER MIDNIGHT WITH THE PASSAGE OF THE SFC COLD FRONT... STRONG SYNOPTIC WIND GUSTS BEHIND THE FRONT DUE TO CONTINUED DEEPENING OF THE SFC LOW OVR NRN LWR MI WILL LEAD TO SOME GUSTS TO 50 MPH OVERNIGHT INTO FRIDAY. CONVECTIVE SHOWERS WITH HIGH CLOUD BASES UNDER THE UPPER LOW ON FRIDAY COULD HELP PROMOTE STRONG GUSTS AS WELL. WILL ISSUE A WIND ADVISORY FOR LATE TONIGHT AND FRIDAY. THINGS QUIET DOWN CONSIDERABLY FRIDAY NIGHT AS HIGH PRESSURE BUILDS IN. .LONG TERM...(SUNDAY THROUGH THURSDAY) ISSUED AT 330 PM EDT THU APR 9 2015 WARMER THAN NORMAL WEATHER FOR A CHANGE FROM SUNDAY AT LEAST INTO WEDNESDAY OF NEXT WEEK. STILL A CHANCE OF A WET STRETCH ON WEDNESDAY OR THURSDAY BUT TIMING IS REALLY UNCERTAIN. OVERALL PATTER IS SOMEWHAT PROGRESSIVE WITH GOOD NWP AGREEMENT ON WEST COAST TROF AND EAST COAST RIDGE DEVELOPING EARLY NEXT WEEK. SUCH A PATTERN WILL PROVIDE THE WARMTH WITH POSITIVE H85 TEMPS THROUGHOUT NEXT WEEK. AFTER MID 60S ON SUNDAY A COLD FRONT WILL PUSH THROUGH MONDAY MORNING. THINKING IT WILL LIKELY COOL MONDAY BY JUST A FEW DEGREES OVER SUNDAY AS THE UPSTREAM HIGH IS WEAK AND THERE IS JUST NOT MUCH OF A PUSH OF COLD AIR. THERE WILL BE SOME DECENT MOISTURE ADVECTION ALONG AND AHEAD OF THE FRONT SUNDAY EVENING SO STILL THINKING SCT SHOWERS ARE A GOOD BET WITH THE FRONTAL PASSAGE ITSELF. IN ANY CASE IT SHOULD BE A QUICK HITTER AND AT LEAST THE LATTER HALF OF MONDAY WILL BE DRY AND SEASONABLE. AFTER THAT THERE IS MUCH DISAGREEMENT ON HOW PROGRESSIVE WEST COAST TROF WILL BE AND HOW MUCH AND WHEN WILL A SOUTHERN STREAM SHORTWAVE EJECT NORTHEAST TOWARDS THE MISSISSIPPI VALLEY AND THEN GREAT LAKES. EACH OF THE PAST FEW DAYS THE GFS/ECM HAVE BEEN DELAYING THE SYSTEM BY A DAY...YESTERDAY THE SIGNAL WAS FOR A WEDNESDAY EVENT WHILE TODAY IT IS NOW LOOKING LIKE A THURSDAY EVENT. BASICALLY...THE POTENTIAL HIS SMEARED OUT IN THE FORECAST WITH CHANCE POPS FOR TUE NIGHT INTO THURSDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 156 PM EDT THU APR 9 2015 WIDESPREAD IFR/LIFR WILL IMPROVE TO MVFR/VFR BY EARLY EVENING AS WARM FRONT PUSHES NORTHWARD. STILL LOOKING AT SEVERAL HOURS OF SHOWER AND THUNDERSTORM ACTIVITY THROUGH MID EVENING...A FEW STORMS COULD PRODUCE DAMAGING WINDS AND HAIL BETWEEN 22Z-04Z THIS EVENING ALONG AND SOUTH OF ROUGHLY A KMKG-KGRR-KAMA LINE. EXPECTING SFC WIND GUSTS IN EXCESS OF 35 KTS FRIDAY MORNING WITH MODERATE CHOP BELOW 5KFT. WINDS WILL SLOWLY DIMINISH TOWARDS FRIDAY EVENING. THERE IS ALSO A CHANCE OF SOME LOW TOP CONVECTIVE SHOWERS WITH SMALL HAIL FRI AFTERNOON/EVENING BETWEEN 21Z - 03Z. && .MARINE... ISSUED AT 330 PM EDT THU APR 9 2015 WILL UPGRADE THE GALE WATCH TO A WARNING AS WINDS INCREASE DRAMATICALLY OUT OF THE WEST LATER TONIGHT BEHIND THE COLD FRONT. && .HYDROLOGY... ISSUED AT 1245 PM EDT THU APR 9 2015 RIVER AND STREAM LEVELS ACROSS SOUTHWEST LOWER MICHIGAN ARE RUNNING NEAR TO A LITTLE BELOW NORMAL... AND ARE CURRENTLY STEADY OR SLOWLY RISING. MORE RISES ARE EXPECTED INTO NEXT WEEK. WIDESPREAD RAINFALL OF AN INCH OR TWO IS POSSIBLE OVER THE NEXT 7 DAYS. THERE IS ALSO A POTENTIAL FOR LOCALLY GREATER RAINFALL AMOUNTS... IF THUNDERSTORMS MOVE OVER THE SAME AREAS. URBAN AND SMALL STREAM FLOODING AND PONDING OF WATER ARE POSSIBLE THIS WEEK... THOUGH RIVERS SHOULD REMAIN MOSTLY WITHIN THEIR BANKS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...WIND ADVISORY FROM 2 AM TO 6 PM EDT FRIDAY FOR MIZ037>040- 043>046-050>052-056>059-064>067-071>074. LM...GALE WARNING FROM MIDNIGHT TONIGHT TO 2 PM EDT FRIDAY FOR LMZ844>849. && $$ SYNOPSIS...MEADE SHORT TERM...MEADE LONG TERM...COBB AVIATION...COBB HYDROLOGY...63 MARINE...MEADE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
203 PM EDT THU APR 9 2015 LATEST UPDATE...AVIATION .SYNOPSIS... ISSUED AT 330 AM EDT THU APR 9 2015 A WET AND INCREASINGLY MILD PERIOD IS EXPECTED THROUGH THE DAY TODAY AND INTO THE EVENING HOURS FOR THE AREA. THIS RESULTS FROM A FRONTAL SYSTEM CURRENTLY ACROSS CENTRAL INDIANA AND ILLINOIS THAT WILL MOVE TOWARD THE AREA TODAY. ROUNDS OF SHOWERS AND STORMS CAN BE EXPECTED. SOME OF THE STORMS COULD BECOME SEVERE LATER THIS AFTERNOON AND THIS EVENING...ESPECIALLY FURTHER SOUTH. A COLD FRONT WILL MOVE THROUGH OVERNIGHT AND BRING AN END TO THE RAIN. WINDS WILL BECOME GUSTY OVERNIGHT AND INTO THE DAY ON FRIDAY. COOLER AIR WILL SETTLE IN WITH A FEW LIGHT RAIN SHOWERS POSSIBLE. CONDITIONS WILL DRY OUT THEN FOR MOST OF THE WEEKEND. THE NEXT CHANCE OF RAIN WILL THEN COME SUNDAY NIGHT. && .UPDATE... ISSUED AT 1145 AM EDT THU APR 9 2015 THE STORY HAS NOT CHANGED MUCH FROM EARLIER. STILL WAITING TO SEE SOME SFC INSTABILITY DEVELOP/SPREAD NORTHEAST OVER THE AREA AND LATEST GUIDANCE STILL HOLDS OFF ON THAT OCCURRING UNTIL AFTER 3-4 PM AT THE EARLIEST. UNTIL THEN... NUMEROUS ELEVATED SHOWERS AND THUNDERSTORMS MOVING THROUGH WITH LOCALLY HEAVY RAIN POSSIBLE NORTH OF THE WARM FRONT. WHILE THE LATEST RUC SHOWS SFC BASED CAPES NEAR 1000 J/KG SPREADING IN BY EARLY EVENING WITH THE WMFNT REACHING NEAR I-96... THAT FAR NORTHWARD EXTENT IS QUESTIONABLE AND THE PROGGED INSTABILITY SOUTH OF MI IS HIGHER. THE LATE DAY/EVENING CONVECTION MAY TEND TO FAVOR THAT AREA OF HIGHER INSTABILITY... SO THE HIGHEST PROBABILITIES FOR SVR ARE FROM THE I-94 CORRIDOR SOUTHWARD. HIGH TEMPS REMAIN CHALLENGING ESPECIALLY SOUTH OF I-96 WHERE HRRR INDICATES 70+ SFC TEMPS DEVELOPING LATE IN THE DAY. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 330 AM EDT THU APR 9 2015 THE MAIN FOCUS OF THE FCST IS ON THE PERIOD FROM THE PRESENT TIME THROUGH THIS EVENING AND DEALING WITH A SEVERE THREAT. AFTER THE SEVERE THREAT...WE WILL NEED TO DEAL WITH SOME POSSIBLE STRONG WINDS FOR LATE TONIGHT AND ON FRI. WE AGREE WITH THE SPC WITH REGARDS TO THE SEVERE POTENTIAL DIMINISHING A BIT FOR TODAY FOR THE AREA IN GENERAL. INITIAL SURGE OF MOISTURE TRANSPORT IS ONGOING ACROSS THE AREA AT THE CURRENT TIME...LEADING TO A BAND OF SHOWERS AND STORMS ACROSS THE SW PORTION OF THE AREA. THIS CONVECTION PRODUCED SOME ISOLATED REPORTS OF MARGINALLY SEVERE HAIL ACROSS IL AND IN A LITTLE EARLIER. THE CONVECTION CONTINUES TO MARCH TO THE NE...HOWEVER IT HAS LOST ITS PUNCH A BIT AS IT IS MOVING INTO A MORE STABLE ATMOSPHERE. THIS FIRST LINE OF SHOWERS/STORMS WILL MARCH NE THROUGH THE CWFA...WITH MORE UPSTREAM ACROSS THE MISSISSIPPI RIVER THAT WILL MOVE INTO THE AREA LATER THIS MORNING/THIS AFTERNOON. OCCASIONAL SHOWERS AND STORMS WILL BE PRESENT THROUGHOUT THE DAY TODAY AS THE NOSE OF THE LLJ AND MOISTURE TRANSPORT REMAINS AIMED AT THE AREA UNTIL AFTER 00Z TONIGHT. EVERYTHING IS ELEVATED CURRENTLY WITH THE WARM FRONT STILL SITTING ACROSS CENTRAL IL AND IN AS OF 07Z THIS MORNING. WE WILL SEE THE TRUE WARM FRONT LIKELY MOVE UP INTO THE SRN/CENTRAL PORTION OF THE CWFA LATER THIS AFTERNOON AS THE UPPER WAVE COMING INTO THE CENTRAL PLAINS MOVES CLOSER TO THE AREA. WE WILL SEE SFC BASED INSTABILITY OF UP TO 1000 J/KG SNEAK INTO THE AREA AFTER 18Z AND MORE TOWARD 00Z. THE DEGREE OF SFC BASED INSTABILITY IS A FAIR AMOUNT LESS THAN THE AMOUNT THAT BUILDS SOUTH AND WEST OF THE CWFA DURING PEAK HEATING. LOW CLOUDS NORTH OF THE WARM FRONT AND THE ROUNDS OF CONVECTION WILL LIMIT THE NRN PROGRESS OF THE TRUE WARM SECTOR. EVEN WITH INSTABILITY LIMITED...THE STRONG FORCING AHEAD OF THE INCOMING WAVE AND FAIRLY DECENT DEEP LAYER SHEAR VALUES OF 35 TO 40 KNOTS KEEPS SEVERE WX IN PLAY ESPECIALLY DOWN SOUTH. WIND DAMAGE WILL BE THE MAIN THREAT WITH STRONG WINDS ONLY 2K FT OFF OF THE SFC AND A UNIDIRECTIONAL PROFILE. HAIL WILL BE POSSIBLE...HOWEVER LIMITED CAPE IN THE -10 TO -30C LAYER WILL KEEP HAIL FROM BECOMING TOO LARGE FOR THE AREA. A TORNADO REMAINS POSSIBLE WITH THE 0-1KM HELICITY VALUES OF 100-200 M2/S2 FCST NEAR THE WARM FRONT IN THE AREA. STRONG WINDS WILL PICK UP BEHIND THE FRONT TOWARD MIDNIGHT TONIGHT. THE CORE OF THE WINDS WILL THEN COME THROUGH DURING THE DAY ON FRI. THERE IS A GOOD POTENTIAL TO TAP 40+ KNOTS OF WIND FRI MORNING/AFTERNOON. A HIGH WIND WATCH WAS CONSIDERED...HOWEVER IT SEEMS LIKE IT WILL END UP AS A SOLID ADVISORY EVENT. SOME WRAP AROUND RAIN SHOWERS WILL BE POSSIBLE UP NORTH EARLY FRI...AND THEN DOWN SOUTH FRI AFTERNOON/EVENING AS THE LAST UPPER WAVE COMES THROUGH. THIS SHOULD NOT BE SIGNIFICANT. .LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 330 AM EDT THU APR 9 2015 IT WOULD SEEM MORE THAN ANYTHING NEXT WEEK WILL BE WARMER THAN NORMAL. THE PROSPECT FOR A SIGNIFICANT PRECIPITATION EVENT SEEMS TO BE DIMINISHING AS THE MODELS ARE TRENDING AWAY FROM PHASING THE NORTHERN AND SOUTHERN STREAM SYSTEMS. STILL THERE WOULD BE A THREAT FOR SHOWERS AND THUNDERSTORMS FROM TUESDAY NIGHT THROUGH WEDNESDAY AND ACTUALLY THE THREAT LOOKS BETTER THURSDAY. THERE SEEMS TO BE A QUASI-ZONAL FLOW ACROSS THE CENTRAL PACIFIC CURRENTLY BUT OVER THE NEXT 5 DAYS THAT BREAKS DOWN INTO A SERIES OF AMPLIFIED UPPER LEVEL WAVES. THAT TRANSITION SHOULD SLOW DOWN THE PROGRESS OF WEST TO EAST MOVING UPPER WAVES AND HENCE OUR SURFACE WEATHER. THE FIRST WAVE EJECTING OUT OF THE EASTERN PACIFIC STAYS NORTHERN STREAM AND MOST OF THAT ENERGY IS UP IN CANADA... STILL THAT SHOULD BRING A WEAK COLD FRONT THROUGH MONDAY MORNING. THE CANADIAN GEM IS SLOWER THAN THE OTHER MODELS WITH THIS BUT WITH CONSENSUS FAVORING THE FASTER ECMWF AND GFS... I TRENDED THE FORECAST FOR MONDAY DRY. SIGNIFICANT SHORTWAVE RIDGING WILL KEEP IT DRY TUESDAY. I WOULD EXCEPT OUR CURRENT POPS FOR TUESDAY TO DIMINISH SIGNIFICANTLY OVER THE NEXT FEW FORECAST CYCLES. OUR CURRENT POP TUESDAY IS MORE OF A TREND THING THAN ANYTHING ELSE. I DO NOT BELIEVE WE WILL SEE ANY RAIN TUESDAY. FINALLY THE ARE SIGNIFICANT MODEL ISSUES ON JUST HOW FAST THE NEXT UPSTREAM WAVE CAN CROSS THE ROCKIES INTO THE CENTRAL PLAINS. I AM THINKING SLOWER IS BETTER. WEDNESDAY MAY BE DRY TOO. WITH THE POLAR JET UP IN CANADA MOST OF NEXT WEEK TEMPERATURES SHOULD BE WARMER THAN NORMAL THROUGH THE WEEK. THE WARMEST WEATHER WILL BE LATER IN THE WEEK AS THE NEXT UPSTREAM SYSTEM SLOWLY MOVES EAST BRING INCREASED SOUTHERLY WINDS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 156 PM EDT THU APR 9 2015 WIDESPREAD IFR/LIFR WILL IMPROVE TO MVFR/VFR BY EARLY EVENING AS WARM FRONT PUSHES NORTHWARD. STILL LOOKING AT SEVERAL HOURS OF SHOWER AND THUNDERSTORM ACTIVITY THROUGH MID EVENING...A FEW STORMS COULD PRODUCE DAMAGING WINDS AND HAIL BETWEEN 22Z-04Z THIS EVENING ALONG AND SOUTH OF ROUGHLY A KMKG-KGRR-KAMA LINE. EXPECTING SFC WIND GUSTS IN EXCESS OF 35 KTS FRIDAY MORNING WITH MODERATE CHOP BELOW 5KFT. WINDS WILL SLOWLY DIMINISH TOWARDS FRIDAY EVENING. THERE IS ALSO A CHANCE OF SOME LOW TOP CONVECTIVE SHOWERS WITH SMALL HAIL FRI AFTERNOON/EVENING BETWEEN 21Z - 03Z. && .MARINE... ISSUED AT 330 AM EDT THU APR 9 2015 WE WILL BE ISSUING A GALE WATCH FOR THE ENTIRE NEARSHORE WATERS FOR OVERNIGHT TONIGHT AND THROUGH THE DAY ON FRIDAY. WINDS WILL RAMP UP SIGNIFICANTLY AND FROM THE WEST NORTHWEST THIS EVENING AND OVERNIGHT TONIGHT AS THE COLD FRONT MOVES THROUGH AND THE COLDER AIR MOVES IN. WE ARE LOOKING AT TAPPING 40+ KNOTS OF WIND LATER TONIGHT AND INTO FRIDAY AFTERNOON. WINDS SHOULD COME DOWN FRIDAY EVENING AS THE GRADIENT RELAXES. && .HYDROLOGY... ISSUED AT 1245 PM EDT THU APR 9 2015 RIVER AND STREAM LEVELS ACROSS SOUTHWEST LOWER MICHIGAN ARE RUNNING NEAR TO A LITTLE BELOW NORMAL... AND ARE CURRENTLY STEADY OR SLOWLY RISING. MORE RISES ARE EXPECTED INTO NEXT WEEK. WIDESPREAD RAINFALL OF AN INCH OR TWO IS POSSIBLE OVER THE NEXT 7 DAYS. THERE IS ALSO A POTENTIAL FOR LOCALLY GREATER RAINFALL AMOUNTS... IF THUNDERSTORMS MOVE OVER THE SAME AREAS. URBAN AND SMALL STREAM FLOODING AND PONDING OF WATER ARE POSSIBLE THIS WEEK... THOUGH RIVERS SHOULD REMAIN MOSTLY WITHIN THEIR BANKS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...GALE WATCH FROM 11 PM EDT THIS EVENING THROUGH FRIDAY EVENING FOR LMZ844>849. && $$ UPDATE...MEADE SYNOPSIS...NJJ SHORT TERM...NJJ LONG TERM...WDM AVIATION...COBB HYDROLOGY...63 MARINE...NJJ
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1246 PM EDT THU APR 9 2015 LATEST UPDATE... HYDRO .SYNOPSIS... ISSUED AT 330 AM EDT THU APR 9 2015 A WET AND INCREASINGLY MILD PERIOD IS EXPECTED THROUGH THE DAY TODAY AND INTO THE EVENING HOURS FOR THE AREA. THIS RESULTS FROM A FRONTAL SYSTEM CURRENTLY ACROSS CENTRAL INDIANA AND ILLINOIS THAT WILL MOVE TOWARD THE AREA TODAY. ROUNDS OF SHOWERS AND STORMS CAN BE EXPECTED. SOME OF THE STORMS COULD BECOME SEVERE LATER THIS AFTERNOON AND THIS EVENING...ESPECIALLY FURTHER SOUTH. A COLD FRONT WILL MOVE THROUGH OVERNIGHT AND BRING AN END TO THE RAIN. WINDS WILL BECOME GUSTY OVERNIGHT AND INTO THE DAY ON FRIDAY. COOLER AIR WILL SETTLE IN WITH A FEW LIGHT RAIN SHOWERS POSSIBLE. CONDITIONS WILL DRY OUT THEN FOR MOST OF THE WEEKEND. THE NEXT CHANCE OF RAIN WILL THEN COME SUNDAY NIGHT. && .UPDATE... ISSUED AT 1145 AM EDT THU APR 9 2015 THE STORY HAS NOT CHANGED MUCH FROM EARLIER. STILL WAITING TO SEE SOME SFC INSTABILITY DEVELOP/SPREAD NORTHEAST OVER THE AREA AND LATEST GUIDANCE STILL HOLDS OFF ON THAT OCCURRING UNTIL AFTER 3-4 PM AT THE EARLIEST. UNTIL THEN... NUMEROUS ELEVATED SHOWERS AND THUNDERSTORMS MOVING THROUGH WITH LOCALLY HEAVY RAIN POSSIBLE NORTH OF THE WARM FRONT. WHILE THE LATEST RUC SHOWS SFC BASED CAPES NEAR 1000 J/KG SPREADING IN BY EARLY EVENING WITH THE WMFNT REACHING NEAR I-96... THAT FAR NORTHWARD EXTENT IS QUESTIONABLE AND THE PROGGED INSTABILITY SOUTH OF MI IS HIGHER. THE LATE DAY/EVENING CONVECTION MAY TEND TO FAVOR THAT AREA OF HIGHER INSTABILITY... SO THE HIGHEST PROBABILITIES FOR SVR ARE FROM THE I-94 CORRIDOR SOUTHWARD. HIGH TEMPS REMAIN CHALLENGING ESPECIALLY SOUTH OF I-96 WHERE HRRR INDICATES 70+ SFC TEMPS DEVELOPING LATE IN THE DAY. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 330 AM EDT THU APR 9 2015 THE MAIN FOCUS OF THE FCST IS ON THE PERIOD FROM THE PRESENT TIME THROUGH THIS EVENING AND DEALING WITH A SEVERE THREAT. AFTER THE SEVERE THREAT...WE WILL NEED TO DEAL WITH SOME POSSIBLE STRONG WINDS FOR LATE TONIGHT AND ON FRI. WE AGREE WITH THE SPC WITH REGARDS TO THE SEVERE POTENTIAL DIMINISHING A BIT FOR TODAY FOR THE AREA IN GENERAL. INITIAL SURGE OF MOISTURE TRANSPORT IS ONGOING ACROSS THE AREA AT THE CURRENT TIME...LEADING TO A BAND OF SHOWERS AND STORMS ACROSS THE SW PORTION OF THE AREA. THIS CONVECTION PRODUCED SOME ISOLATED REPORTS OF MARGINALLY SEVERE HAIL ACROSS IL AND IN A LITTLE EARLIER. THE CONVECTION CONTINUES TO MARCH TO THE NE...HOWEVER IT HAS LOST ITS PUNCH A BIT AS IT IS MOVING INTO A MORE STABLE ATMOSPHERE. THIS FIRST LINE OF SHOWERS/STORMS WILL MARCH NE THROUGH THE CWFA...WITH MORE UPSTREAM ACROSS THE MISSISSIPPI RIVER THAT WILL MOVE INTO THE AREA LATER THIS MORNING/THIS AFTERNOON. OCCASIONAL SHOWERS AND STORMS WILL BE PRESENT THROUGHOUT THE DAY TODAY AS THE NOSE OF THE LLJ AND MOISTURE TRANSPORT REMAINS AIMED AT THE AREA UNTIL AFTER 00Z TONIGHT. EVERYTHING IS ELEVATED CURRENTLY WITH THE WARM FRONT STILL SITTING ACROSS CENTRAL IL AND IN AS OF 07Z THIS MORNING. WE WILL SEE THE TRUE WARM FRONT LIKELY MOVE UP INTO THE SRN/CENTRAL PORTION OF THE CWFA LATER THIS AFTERNOON AS THE UPPER WAVE COMING INTO THE CENTRAL PLAINS MOVES CLOSER TO THE AREA. WE WILL SEE SFC BASED INSTABILITY OF UP TO 1000 J/KG SNEAK INTO THE AREA AFTER 18Z AND MORE TOWARD 00Z. THE DEGREE OF SFC BASED INSTABILITY IS A FAIR AMOUNT LESS THAN THE AMOUNT THAT BUILDS SOUTH AND WEST OF THE CWFA DURING PEAK HEATING. LOW CLOUDS NORTH OF THE WARM FRONT AND THE ROUNDS OF CONVECTION WILL LIMIT THE NRN PROGRESS OF THE TRUE WARM SECTOR. EVEN WITH INSTABILITY LIMITED...THE STRONG FORCING AHEAD OF THE INCOMING WAVE AND FAIRLY DECENT DEEP LAYER SHEAR VALUES OF 35 TO 40 KNOTS KEEPS SEVERE WX IN PLAY ESPECIALLY DOWN SOUTH. WIND DAMAGE WILL BE THE MAIN THREAT WITH STRONG WINDS ONLY 2K FT OFF OF THE SFC AND A UNIDIRECTIONAL PROFILE. HAIL WILL BE POSSIBLE...HOWEVER LIMITED CAPE IN THE -10 TO -30C LAYER WILL KEEP HAIL FROM BECOMING TOO LARGE FOR THE AREA. A TORNADO REMAINS POSSIBLE WITH THE 0-1KM HELICITY VALUES OF 100-200 M2/S2 FCST NEAR THE WARM FRONT IN THE AREA. STRONG WINDS WILL PICK UP BEHIND THE FRONT TOWARD MIDNIGHT TONIGHT. THE CORE OF THE WINDS WILL THEN COME THROUGH DURING THE DAY ON FRI. THERE IS A GOOD POTENTIAL TO TAP 40+ KNOTS OF WIND FRI MORNING/AFTERNOON. A HIGH WIND WATCH WAS CONSIDERED...HOWEVER IT SEEMS LIKE IT WILL END UP AS A SOLID ADVISORY EVENT. SOME WRAP AROUND RAIN SHOWERS WILL BE POSSIBLE UP NORTH EARLY FRI...AND THEN DOWN SOUTH FRI AFTERNOON/EVENING AS THE LAST UPPER WAVE COMES THROUGH. THIS SHOULD NOT BE SIGNIFICANT. .LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 330 AM EDT THU APR 9 2015 IT WOULD SEEM MORE THAN ANYTHING NEXT WEEK WILL BE WARMER THAN NORMAL. THE PROSPECT FOR A SIGNIFICANT PRECIPITATION EVENT SEEMS TO BE DIMINISHING AS THE MODELS ARE TRENDING AWAY FROM PHASING THE NORTHERN AND SOUTHERN STREAM SYSTEMS. STILL THERE WOULD BE A THREAT FOR SHOWERS AND THUNDERSTORMS FROM TUESDAY NIGHT THROUGH WEDNESDAY AND ACTUALLY THE THREAT LOOKS BETTER THURSDAY. THERE SEEMS TO BE A QUASI-ZONAL FLOW ACROSS THE CENTRAL PACIFIC CURRENTLY BUT OVER THE NEXT 5 DAYS THAT BREAKS DOWN INTO A SERIES OF AMPLIFIED UPPER LEVEL WAVES. THAT TRANSITION SHOULD SLOW DOWN THE PROGRESS OF WEST TO EAST MOVING UPPER WAVES AND HENCE OUR SURFACE WEATHER. THE FIRST WAVE EJECTING OUT OF THE EASTERN PACIFIC STAYS NORTHERN STREAM AND MOST OF THAT ENERGY IS UP IN CANADA... STILL THAT SHOULD BRING A WEAK COLD FRONT THROUGH MONDAY MORNING. THE CANADIAN GEM IS SLOWER THAN THE OTHER MODELS WITH THIS BUT WITH CONSENSUS FAVORING THE FASTER ECMWF AND GFS... I TRENDED THE FORECAST FOR MONDAY DRY. SIGNIFICANT SHORTWAVE RIDGING WILL KEEP IT DRY TUESDAY. I WOULD EXCEPT OUR CURRENT POPS FOR TUESDAY TO DIMINISH SIGNIFICANTLY OVER THE NEXT FEW FORECAST CYCLES. OUR CURRENT POP TUESDAY IS MORE OF A TREND THING THAN ANYTHING ELSE. I DO NOT BELIEVE WE WILL SEE ANY RAIN TUESDAY. FINALLY THE ARE SIGNIFICANT MODEL ISSUES ON JUST HOW FAST THE NEXT UPSTREAM WAVE CAN CROSS THE ROCKIES INTO THE CENTRAL PLAINS. I AM THINKING SLOWER IS BETTER. WEDNESDAY MAY BE DRY TOO. WITH THE POLAR JET UP IN CANADA MOST OF NEXT WEEK TEMPERATURES SHOULD BE WARMER THAN NORMAL THROUGH THE WEEK. THE WARMEST WEATHER WILL BE LATER IN THE WEEK AS THE NEXT UPSTREAM SYSTEM SLOWLY MOVES EAST BRING INCREASED SOUTHERLY WINDS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 753 AM EDT THU APR 9 2015 FOR THE MOST PART EXPECT PERIODS OF THUNDERSTORMS INTO THIS EVENING. LOW CLOUDS WITH IFR / MVFR CIGS WILL ALSO PREVAIL MOST OF THE DAY. THE WARM FRONT WILL STRUGGLE TO REACH I-94 BY LATE AFTERNOON. IF THE WARM FRONT DOES IN FACT REACH I-94 CEILINGS MAY BECOME VFR FOR A FEW HOURS. THE STRONGEST STORMS SHOULD BE THIS EVENING JUST AHEAD OF THE COLD FRONT. ONCE THE COLD FRONT COMES THROUGH WINDS WILL TURN TO THE SOUTHWEST AND INCREASE TO 20 TO 30 KNOTS. CIGS WILL REMAIN MVFR THROUGH SUNRISE FRIDAY. SHOWERS ARE POSSIBLE IN THE COLD UNSTABLE AIR BEHIND THE COLD FRONT. && .MARINE... ISSUED AT 330 AM EDT THU APR 9 2015 WE WILL BE ISSUING A GALE WATCH FOR THE ENTIRE NEARSHORE WATERS FOR OVERNIGHT TONIGHT AND THROUGH THE DAY ON FRIDAY. WINDS WILL RAMP UP SIGNIFICANTLY AND FROM THE WEST NORTHWEST THIS EVENING AND OVERNIGHT TONIGHT AS THE COLD FRONT MOVES THROUGH AND THE COLDER AIR MOVES IN. WE ARE LOOKING AT TAPPING 40+ KNOTS OF WIND LATER TONIGHT AND INTO FRIDAY AFTERNOON. WINDS SHOULD COME DOWN FRIDAY EVENING AS THE GRADIENT RELAXES. && .HYDROLOGY... ISSUED AT 1245 PM EDT THU APR 9 2015 RIVER AND STREAM LEVELS ACROSS SOUTHWEST LOWER MICHIGAN ARE RUNNING NEAR TO A LITTLE BELOW NORMAL... AND ARE CURRENTLY STEADY OR SLOWLY RISING. MORE RISES ARE EXPECTED INTO NEXT WEEK. WIDESPREAD RAINFALL OF AN INCH OR TWO IS POSSIBLE OVER THE NEXT 7 DAYS. THERE IS ALSO A POTENTIAL FOR LOCALLY GREATER RAINFALL AMOUNTS... IF THUNDERSTORMS MOVE OVER THE SAME AREAS. URBAN AND SMALL STREAM FLOODING AND PONDING OF WATER ARE POSSIBLE THIS WEEK... THOUGH RIVERS SHOULD REMAIN MOSTLY WITHIN THEIR BANKS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...GALE WATCH FROM 11 PM EDT THIS EVENING THROUGH FRIDAY EVENING FOR LMZ844>849. && $$ UPDATE...MEADE SYNOPSIS...NJJ SHORT TERM...NJJ LONG TERM...WDM AVIATION...WDM HYDROLOGY...63 MARINE...NJJ
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1147 AM EDT THU APR 9 2015 LATEST UPDATE... UPDATE .SYNOPSIS... ISSUED AT 330 AM EDT THU APR 9 2015 A WET AND INCREASINGLY MILD PERIOD IS EXPECTED THROUGH THE DAY TODAY AND INTO THE EVENING HOURS FOR THE AREA. THIS RESULTS FROM A FRONTAL SYSTEM CURRENTLY ACROSS CENTRAL INDIANA AND ILLINOIS THAT WILL MOVE TOWARD THE AREA TODAY. ROUNDS OF SHOWERS AND STORMS CAN BE EXPECTED. SOME OF THE STORMS COULD BECOME SEVERE LATER THIS AFTERNOON AND THIS EVENING...ESPECIALLY FURTHER SOUTH. A COLD FRONT WILL MOVE THROUGH OVERNIGHT AND BRING AN END TO THE RAIN. WINDS WILL BECOME GUSTY OVERNIGHT AND INTO THE DAY ON FRIDAY. COOLER AIR WILL SETTLE IN WITH A FEW LIGHT RAIN SHOWERS POSSIBLE. CONDITIONS WILL DRY OUT THEN FOR MOST OF THE WEEKEND. THE NEXT CHANCE OF RAIN WILL THEN COME SUNDAY NIGHT. && .UPDATE... ISSUED AT 1145 AM EDT THU APR 9 2015 THE STORY HAS NOT CHANGED MUCH FROM EARLIER. STILL WAITING TO SEE SOME SFC INSTABILITY DEVELOP/SPREAD NORTHEAST OVER THE AREA AND LATEST GUIDANCE STILL HOLDS OFF ON THAT OCCURRING UNTIL AFTER 3-4 PM AT THE EARLIEST. UNTIL THEN... NUMEROUS ELEVATED SHOWERS AND THUNDERSTORMS MOVING THROUGH WITH LOCALLY HEAVY RAIN POSSIBLE NORTH OF THE WARM FRONT. WHILE THE LATEST RUC SHOWS SFC BASED CAPES NEAR 1000 J/KG SPREADING IN BY EARLY EVENING WITH THE WMFNT REACHING NEAR I-96... THAT FAR NORTHWARD EXTENT IS QUESTIONABLE AND THE PROGGED INSTABILITY SOUTH OF MI IS HIGHER. THE LATE DAY/EVENING CONVECTION MAY TEND TO FAVOR THAT AREA OF HIGHER INSTABILITY... SO THE HIGHEST PROBABILITIES FOR SVR ARE FROM THE I-94 CORRIDOR SOUTHWARD. HIGH TEMPS REMAIN CHALLENGING ESPECIALLY SOUTH OF I-96 WHERE HRRR INDICATES 70+ SFC TEMPS DEVELOPING LATE IN THE DAY. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 330 AM EDT THU APR 9 2015 THE MAIN FOCUS OF THE FCST IS ON THE PERIOD FROM THE PRESENT TIME THROUGH THIS EVENING AND DEALING WITH A SEVERE THREAT. AFTER THE SEVERE THREAT...WE WILL NEED TO DEAL WITH SOME POSSIBLE STRONG WINDS FOR LATE TONIGHT AND ON FRI. WE AGREE WITH THE SPC WITH REGARDS TO THE SEVERE POTENTIAL DIMINISHING A BIT FOR TODAY FOR THE AREA IN GENERAL. INITIAL SURGE OF MOISTURE TRANSPORT IS ONGOING ACROSS THE AREA AT THE CURRENT TIME...LEADING TO A BAND OF SHOWERS AND STORMS ACROSS THE SW PORTION OF THE AREA. THIS CONVECTION PRODUCED SOME ISOLATED REPORTS OF MARGINALLY SEVERE HAIL ACROSS IL AND IN A LITTLE EARLIER. THE CONVECTION CONTINUES TO MARCH TO THE NE...HOWEVER IT HAS LOST ITS PUNCH A BIT AS IT IS MOVING INTO A MORE STABLE ATMOSPHERE. THIS FIRST LINE OF SHOWERS/STORMS WILL MARCH NE THROUGH THE CWFA...WITH MORE UPSTREAM ACROSS THE MISSISSIPPI RIVER THAT WILL MOVE INTO THE AREA LATER THIS MORNING/THIS AFTERNOON. OCCASIONAL SHOWERS AND STORMS WILL BE PRESENT THROUGHOUT THE DAY TODAY AS THE NOSE OF THE LLJ AND MOISTURE TRANSPORT REMAINS AIMED AT THE AREA UNTIL AFTER 00Z TONIGHT. EVERYTHING IS ELEVATED CURRENTLY WITH THE WARM FRONT STILL SITTING ACROSS CENTRAL IL AND IN AS OF 07Z THIS MORNING. WE WILL SEE THE TRUE WARM FRONT LIKELY MOVE UP INTO THE SRN/CENTRAL PORTION OF THE CWFA LATER THIS AFTERNOON AS THE UPPER WAVE COMING INTO THE CENTRAL PLAINS MOVES CLOSER TO THE AREA. WE WILL SEE SFC BASED INSTABILITY OF UP TO 1000 J/KG SNEAK INTO THE AREA AFTER 18Z AND MORE TOWARD 00Z. THE DEGREE OF SFC BASED INSTABILITY IS A FAIR AMOUNT LESS THAN THE AMOUNT THAT BUILDS SOUTH AND WEST OF THE CWFA DURING PEAK HEATING. LOW CLOUDS NORTH OF THE WARM FRONT AND THE ROUNDS OF CONVECTION WILL LIMIT THE NRN PROGRESS OF THE TRUE WARM SECTOR. EVEN WITH INSTABILITY LIMITED...THE STRONG FORCING AHEAD OF THE INCOMING WAVE AND FAIRLY DECENT DEEP LAYER SHEAR VALUES OF 35 TO 40 KNOTS KEEPS SEVERE WX IN PLAY ESPECIALLY DOWN SOUTH. WIND DAMAGE WILL BE THE MAIN THREAT WITH STRONG WINDS ONLY 2K FT OFF OF THE SFC AND A UNIDIRECTIONAL PROFILE. HAIL WILL BE POSSIBLE...HOWEVER LIMITED CAPE IN THE -10 TO -30C LAYER WILL KEEP HAIL FROM BECOMING TOO LARGE FOR THE AREA. A TORNADO REMAINS POSSIBLE WITH THE 0-1KM HELICITY VALUES OF 100-200 M2/S2 FCST NEAR THE WARM FRONT IN THE AREA. STRONG WINDS WILL PICK UP BEHIND THE FRONT TOWARD MIDNIGHT TONIGHT. THE CORE OF THE WINDS WILL THEN COME THROUGH DURING THE DAY ON FRI. THERE IS A GOOD POTENTIAL TO TAP 40+ KNOTS OF WIND FRI MORNING/AFTERNOON. A HIGH WIND WATCH WAS CONSIDERED...HOWEVER IT SEEMS LIKE IT WILL END UP AS A SOLID ADVISORY EVENT. SOME WRAP AROUND RAIN SHOWERS WILL BE POSSIBLE UP NORTH EARLY FRI...AND THEN DOWN SOUTH FRI AFTERNOON/EVENING AS THE LAST UPPER WAVE COMES THROUGH. THIS SHOULD NOT BE SIGNIFICANT. .LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 330 AM EDT THU APR 9 2015 IT WOULD SEEM MORE THAN ANYTHING NEXT WEEK WILL BE WARMER THAN NORMAL. THE PROSPECT FOR A SIGNIFICANT PRECIPITATION EVENT SEEMS TO BE DIMINISHING AS THE MODELS ARE TRENDING AWAY FROM PHASING THE NORTHERN AND SOUTHERN STREAM SYSTEMS. STILL THERE WOULD BE A THREAT FOR SHOWERS AND THUNDERSTORMS FROM TUESDAY NIGHT THROUGH WEDNESDAY AND ACTUALLY THE THREAT LOOKS BETTER THURSDAY. THERE SEEMS TO BE A QUASI-ZONAL FLOW ACROSS THE CENTRAL PACIFIC CURRENTLY BUT OVER THE NEXT 5 DAYS THAT BREAKS DOWN INTO A SERIES OF AMPLIFIED UPPER LEVEL WAVES. THAT TRANSITION SHOULD SLOW DOWN THE PROGRESS OF WEST TO EAST MOVING UPPER WAVES AND HENCE OUR SURFACE WEATHER. THE FIRST WAVE EJECTING OUT OF THE EASTERN PACIFIC STAYS NORTHERN STREAM AND MOST OF THAT ENERGY IS UP IN CANADA... STILL THAT SHOULD BRING A WEAK COLD FRONT THROUGH MONDAY MORNING. THE CANADIAN GEM IS SLOWER THAN THE OTHER MODELS WITH THIS BUT WITH CONSENSUS FAVORING THE FASTER ECMWF AND GFS... I TRENDED THE FORECAST FOR MONDAY DRY. SIGNIFICANT SHORTWAVE RIDGING WILL KEEP IT DRY TUESDAY. I WOULD EXCEPT OUR CURRENT POPS FOR TUESDAY TO DIMINISH SIGNIFICANTLY OVER THE NEXT FEW FORECAST CYCLES. OUR CURRENT POP TUESDAY IS MORE OF A TREND THING THAN ANYTHING ELSE. I DO NOT BELIEVE WE WILL SEE ANY RAIN TUESDAY. FINALLY THE ARE SIGNIFICANT MODEL ISSUES ON JUST HOW FAST THE NEXT UPSTREAM WAVE CAN CROSS THE ROCKIES INTO THE CENTRAL PLAINS. I AM THINKING SLOWER IS BETTER. WEDNESDAY MAY BE DRY TOO. WITH THE POLAR JET UP IN CANADA MOST OF NEXT WEEK TEMPERATURES SHOULD BE WARMER THAN NORMAL THROUGH THE WEEK. THE WARMEST WEATHER WILL BE LATER IN THE WEEK AS THE NEXT UPSTREAM SYSTEM SLOWLY MOVES EAST BRING INCREASED SOUTHERLY WINDS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 753 AM EDT THU APR 9 2015 FOR THE MOST PART EXPECT PERIODS OF THUNDERSTORMS INTO THIS EVENING. LOW CLOUDS WITH IFR / MVFR CIGS WILL ALSO PREVAIL MOST OF THE DAY. THE WARM FRONT WILL STRUGGLE TO REACH I-94 BY LATE AFTERNOON. IF THE WARM FRONT DOES IN FACT REACH I-94 CEILINGS MAY BECOME VFR FOR A FEW HOURS. THE STRONGEST STORMS SHOULD BE THIS EVENING JUST AHEAD OF THE COLD FRONT. ONCE THE COLD FRONT COMES THROUGH WINDS WILL TURN TO THE SOUTHWEST AND INCREASE TO 20 TO 30 KNOTS. CIGS WILL REMAIN MVFR THROUGH SUNRISE FRIDAY. SHOWERS ARE POSSIBLE IN THE COLD UNSTABLE AIR BEHIND THE COLD FRONT. && .MARINE... ISSUED AT 330 AM EDT THU APR 9 2015 WE WILL BE ISSUING A GALE WATCH FOR THE ENTIRE NEARSHORE WATERS FOR OVERNIGHT TONIGHT AND THROUGH THE DAY ON FRIDAY. WINDS WILL RAMP UP SIGNIFICANTLY AND FROM THE WEST NORTHWEST THIS EVENING AND OVERNIGHT TONIGHT AS THE COLD FRONT MOVES THROUGH AND THE COLDER AIR MOVES IN. WE ARE LOOKING AT TAPPING 40+ KNOTS OF WIND LATER TONIGHT AND INTO FRIDAY AFTERNOON. WINDS SHOULD COME DOWN FRIDAY EVENING AS THE GRADIENT RELAXES. && .HYDROLOGY... ISSUED AT 111 PM EDT WED APR 8 2015 RIVER AND STREAM LEVELS ACROSS SOUTHWEST LOWER MICHIGAN ARE RUNNING NEAR TO A LITTLE BELOW NORMAL. RIVER LEVELS ARE CURRENTLY STEADY OR SLOWLY RISING. MORE RISES ARE EXPECTED INTO NEXT WEEK. WIDESPREAD RAINFALL OF AN INCH OR TWO IS POSSIBLE OVER THE NEXT 7 DAYS. THERE IS ALSO A POTENTIAL FOR LOCALLY GREATER RAINFALL AMOUNTS... IF THUNDERSTORMS MOVE OVER THE SAME AREAS. IN GENERAL...SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED TONIGHT INTO FRIDAY. URBAN AND SMALL STREAM FLOODING AND PONDING OF WATER ARE POSSIBLE... THOUGH RIVERS SHOULD REMAIN MOSTLY WITHIN THEIR BANKS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...GALE WATCH FROM 11 PM EDT THIS EVENING THROUGH FRIDAY EVENING FOR LMZ844>849. && $$ UPDATE...MEADE SYNOPSIS...NJJ SHORT TERM...NJJ LONG TERM...WDM AVIATION...WDM HYDROLOGY...63 MARINE...NJJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
413 AM EDT THU APR 9 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 456 PM EDT WED APR 8 2015 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW PAIR OF SHORTWAVES RESPONSIBLE FOR THE LIGHT WINTRY MIX OF PCPN EARLIER TODAY NOW N AND E OF THE FCST AREA. ANOTHER SHORTWAVE MOVING FROM MANITOBA INTO NRN ONTARIO WON`T BE A FACTOR IN THE SHORT TERM WEATHER. FARTHER TO THE NW AND ALSO TO THE SW ARE 2 SHORTWAVES THAT WILL PLAY A ROLE IN WHAT WILL BECOME A QUICK HITTING SIGNIFICANT SPRING SNOWSTORM FOR PORTIONS OF UPPER MI THU NIGHT. ONE WAVE IS DROPPING INTO NRN MANITOBA AND THE SECOND WAVE IS OVER NV/UT. DETAILS ON THE HVY/WET SNOW CAN BE FOUND IN THE LONG TERM PORTION OF THE DISCUSSION BELOW. IN THE WAKE OF THE PCPN EARLIER TODAY...ABUNDANT CLOUD COVER DOMINATES THE UPPER GREAT LAKES...THOUGH NOT ALL OF THE LOW-LEVEL DRY AIR HAS BEEN ERODED...AND THERE IS STILL A FEED OF DRIER AIR AT THE LOW LEVELS FROM THE E. THIS HAS RESULTED IN SOME BREAKS DEVELOPING IN THE CLOUD COVER OVER UPPER MI IN THE LAST FEW HRS. WHERE SOME SUN HAS APPEARED...TEMPS HAVE RISEN INTO THE MID AND UPPER 40S. SHORTWAVE OVER NV/UT WILL SHIFT E AND RESULT IN SFC LOW PRES DEVELOPING OVER KS TONIGHT. FARTHER DOWNSTREAM...WATER VAPOR IMAGERY SUGGESTS MORE SUBTLE SHORTWAVE ENERGY LIFTING OUT OVER THE PLAINS. INCREASING WAA/ISENTROPIC ASCENT REGIME DOWNSTREAM OF THE MAIN SHORTWAVE TROF AND ENHANCED BY THE SUBTLE LEAD ENERGY WILL LEAD TO A AN AREA OF RAIN DEVELOPING AND SPREADING/EXPANDING NE INTO UPPER MI LATE TONIGHT INTO THU MORNING. BASED ON NRN EDGE OF THE POOL OF MUCAPE THAT LIFTS N INTO WI...NOT OUT OF THE QUESTION THAT THERE COULD BE FEW RUMBLES OF THUNDER. WHETHER TEMPS WILL BE BLO FREEZING WHEN PCPN BEGINS IS UNCERTAIN. USING MODEL CONSENSUS DIURNAL TEMP CURVE SUGGESTS THERE WILL BE AREAS WHERE TEMPS MAY BE JUST BLO FREEZING LATE TONIGHT/EARLY THU MORNING. HOWEVER...IF TEMPS DON`T FALL MUCH THIS EVENING...-FZRA POTENTIAL WILL BE DIMINISHED. AT THIS TIME...NOT EXPECTING SUFFICIENT ICE PROBLEMS ON ROADWAYS TO WARRANT ADVY ISSUANCE...BUT WILL CONTINUE TO HIGHLIGHT POTENTIAL OF SOME ICY CONDITIONS ON UNTREATED SURFACES LATE TONIGHT THRU MID MORNING THU. AFTER THE INITIAL SURGE OF WAA/ISENTROPIC ASCENT PCPN THAT SWEEPS NE LATE TONIGHT/THU MORNING...WILL PROBABLY SEE -RA DIMINISH OR BECOME MORE SCATTERED FOR A TIME LATE MORNING THRU MID AFTN OR SO AS WE AWAIT THE MAIN SHORTWAVE/STRONG DYNAMICS THAT WILL LIFT INTO THE UPPER LAKES THU NIGHT. PCPN IS LESS LIKELY TO DIMINISH OVER THE W WHERE 850MB TROF WILL EXTEND NE FROM THE APPROACHING LOW ACROSS WRN UPPER MI/WRN LAKE SUPERIOR. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 409 AM EDT THU APR 9 2015 MAIN FCST CONCERNS IN THE LONG TERM FOCUS ON IMPACT OF EXITING LO PRES ON FRI/TRAILING SHRTWV AND NEXT CHC FOR RA SUN INTO MON. WHILE FRI WL STILL BE CHILLY IN THE STRONG NW FLOW LEFT IN THE WAKE OF THE DEPARTING LO... EXPECT TEMPS TO RISE ABOVE NORMAL AS A MORE ZONAL PACIFIC FLOW DOMINATES STARTING ON SAT. FRI...AS MAIN NEGATIVELY TILTED SRN BRANCH SHRTWV WITH ACCOMPANYING 990MB OR SO SFC LO JUST E OF THE SAULT AT 12Z FRI LIFT TO THE NE... LARGER SCALE DEEP LYR QVECTOR CNVGC WL EXIT AS WELL IN THE MRNG. THE 00Z GFS IS A BIT SLOWER WITH THIS PROCESS DUE TO A FARTHER W TRACK OF THE SHRTWV/SFC LO...MAINTAINING MORE SGNFT PCPN AND DEEP LYR QVECTOR CNGVC A BIT LONGER. SINCE THE MODELS DO NOT SHOW A QUICK PHASING OF THIS SRN BRANCH SHRTWV AND A NRN BRANCH DISTURBANCE MOVING INTO NRN MN ON FRI MNRG...TENDED AWAY FM THIS SLOWER... DEEPER SCENARIO. LATEST NCEP DISCUSSION SUPPORTS THE DECISION TO RELY MORE HEAVILY ON THE 00Z NAM. BUT THE NAM HAS SLOWED DOWN THE EXIT OF THE SHARPER DYNAMIC FORCING...SO COORDINATED WITH SHORT TERM FCSTR TO EXTEND WINTER WX HEADLINES THRU FRI MRNG FOR THE N HALF OF THE HEADLINE AREA. WHILE THE DEPARTURE OF THE SRN BRANCH DYNAMIC FORCING WL BRING A DIMINISHING TREND TO THE ACCOMPANYING PCPN BY LATE MRNG...MODELS ARE IN GOOD AGREEMENT SHOWING THE NRN BRANCH SHRTWV ACCOMPANIED BY SOME FAIRLY SHARP DPVA/DEEP LYR QVECTOR CNVGC DIGGING INTO THE UPR LKS AND MAINTAINING A SHARP CYC NW FLOW. H925 ARE WINDS FCST AS HI AS 35-45KTS UNDER THE H85 THERMAL TROF TRAILING THE DEPARTING LO. WHILE THE PASSAGE OF THE NRN BRANCH DISTURBANCE LATER IN THE DAY AND ARRIVAL OF LARGER SCALE DNVA/DEEP LYR QVECTOR DVGC WL RESULT IN A WEAKENING OF THE CYC FLOW OVER THE W DURING THE AFTN...SUSPECT SN WL BE RATHER PERSISTENT OVER THE E HALF OF THE CWA. IN FACT...THE 00Z NAM SHOWS ARND 0.35 INCH OF PCPN FALLING AS SN AT ERY...AND MANY OF THE HIER RES MODELS SHOW SIMILAR QPF. SO BUMPED UP POPS OVER ESPECIALLY THE NE HALF OF THE CWA. EVEN THOUGH THE PRES RISE CENTER BEHIND THE DEPARTING LO WL PASS TO THE S OF UPR MI AND ELIMINATE AN ISALLOBARIC WIND COMPONENT...FRI WL BE QUITE WINDY ESPECIALLY OVER THE E...WHERE WIND GUSTS NEAR LK SUP MAY AT LEAST APRCH ADVY CRITERIA. WITH THE NW FLOW OFF MORE EXTENSIVE ICE COVER ACROSS THE E HALF OF THE LK AND MORE PERSISTENT PCPN THERE...LOWERED FCST HI TEMPS OVER THE ERN CWA. FRI NGT...AFTER THE NRN BRANCH SHRTWV DIGS INTO THE CENTRAL GREAT LKS ON FRI EVNG...VIGOROUS DNVA/DEEP LYR QVECTOR DVGC WL OVERSPREAD THE ERN CWA...ENDING LINGERING PCPN THERE. STEADY H5 HGT RISES THAT ARE FCST TO APRCH 100M BTWN 00Z-12Z SAT IN ADVANCE OF TRAILING SHRTWV/SFC RDG AXIS WL BRING CLRG SKIES AS THE LLVL FLOW BECOMES MORE ACYC. RATHER STEADY NW BACKING W FLOW TO THE NE OF HI CENTER MOVING FAIRLY FAR TO THE SW AND INTO THE MID MS RIVER VALLEY WL TEND TO LIMIT THE DIURNAL TEMP DROP...BUT TEMPS SHOULD STILL FALL INTO THE TEENS OVER SOME SN ACROSS THE INTERIOR W HALF...WHICH WL BE CLOSER TO THE WEAKER PRES GRADIENT AND SEE THE EARLIER INFLUX OF PWAT AOB 0.25 INCH. SAT...AS SFC RDG AXIS EXTENDING N OF SFC HI CENTER CROSSING THE LOWER LKS/OH RIVER VALLEY PASSES OVER THE UPR LKS...EXPECT A MOSUNNY DAY. AS LARGER SCALE SUBSIDENCE/WAA IN THE SW FLOW ON THE BACK SIDE OF THE RDG LIFT H85 TEMPS UP TO 4C OVER THE W BY 00Z SUN...EXPECT TEMPS TO REBOUND INTO THE 50S AWAY FM LK MODERATION THAT WL IMPACT MAINLY THE ERN CWA. READINGS MAY EVEN APRCH 60 IN THE DOWNSLOPE AREAS OVER THE W. SAT NGT...AS THE SFC HI PRES SHIFTS TO THE E...WAA/ISENTROPIC ASCENT WL BRING INCRSG MID CLDS. SOME OF THE MODELS EVEN GENERATE SOME LGT RA SHOWERS AT THE NOSE OF H85 SW LLJ UP TO 45-50 KTS UNDER TIGHTENING PRES GRADIENT WITH THE APRCH OF SHRTWV DOWNSTREAM OF A DEEPENING TROF FARTHER W IN THE NRN PLAINS. INITIAL MSTR RETURN DOES NOT APPEAR TO BE THAT SGFNT...SO WL GO WITH JUST LO CHC POPS FOR NOW OVER THE NW HALF OF THE CWA. COMBINATION OF STEADY SW WIND AND INCRSG CLDS WL LIMIT THE DIURNAL TEMP FALL...ESPECIALLY IN THE DOWNSLOPE AREAS OVER THE W. SUN/SUN NGT...AS FAIRLY VIGOROUS DEEP LYR QVECTOR CNVGC/HGT FALLS IN ADVANCE OF UPR TROF MOVING E FM THE NRN PLAINS OVERSPREAD UPR MI AND THE STRONG SW FLOW TAPS MORE COPIOUS MSTR THAT LIFT PWAT CLOSE TO 1 INCH BY 00Z MON...EXPECT MORE NMRS SHOWERS TO OVERSPREAD UPR MI ON SUN AFTN. BUT THIS PCPN WL THEN END W-E SUN NGT AS ACCOMPANYING PACIFIC TYPE COLD FNT CROSSES THE UPR LKS AND BRINGS AN INFLUX OF DRIER AIR IN ADVANCE OF SFC HI PRES. SUSPECT THE RUNOFF FM THE RA AS WELL AS THE RATHER QUICK SN MELT ACCOMPANYING THE FAIRLY DRAMATIC WARMUP MAY CAUSE AREA RIVERS TO RISE FAIRLY QUICKLY. EXTENDED...INCOMING HI PRES/DRY AIRMASS WL BRING A MOSUNNY DAY FOR MON. SINCE THE AIRMASS WL A MARITIME POLAR PACIFIC ONE...MAX TEMPS SHOULD RISE INTO THE 50S AWAY FM LK MODERATION. THEN AN APRCHG WARM FNT ASSOCIATED WITH A DISTURBANCE LIFTING NE INTO THE PLAINS WL BRING A RETURN FOR RA CHANCES NEXT TUE/WED. TEMPS WL BE ABOVE NORMAL WITH PACIFIC AIRMASS IN PLACE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 126 AM EDT THU APR 9 2015 DETERIORATING CONDITIONS WILL CONTINUE OVERNIGHT AT ALL SITES AS MOISTURE AND PCPN SPREAD N LATE TONIGHT/EARLY THU. EXPECT CONDITIONS TO FALL TO IFR AT ALL TERMINALS. PCPN MAY BEGIN AS -FZRA FOR 2-3HRS AT KCMX/KSAW...BUT WILL CHANGE TO -RA AS TEMPS RISE DURING THE MORNING. KSAW IS LIKELY TO FALL TO LIFR BY MID MORNING. BY EVENING...VLIFR/LIFR CONDITIONS WILL BE AT ALL SITES WITH RAIN CHANGING OVER TO SNOW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 409 AM EDT THU APR 9 2015 AS A DEEPENING LO PRES MOVES FROM THE PLAINS THRU THE CENTRAL GREAT LAKES TONIGHT AND INTO SE CANADA ON FRI...EXPECT ENE WINDS UP TO 20 KTS TO BACK TO THE NNW...AND INCREASE UP 35-45 KT GALES OVER MUCH OF THE E HALF OF THE LAKE BY LATE TONIGHT. OPTED TO ISSUE GALE WARNINGS FOR THE E HALF. THESE GALE FORCE NNW WINDS WILL THEN DIMINISH ON FRI AFTERNOON INTO EARLY EVENING AS THE LO PRES EXITS FARTHER TO THE NE AND THE PRES GRADIENT WEAKENS IN ADVANCE OF AN APPROACHING HI PRES RIDGE. LIGHTER WINDS ON SAT WILL THEN BACK TO THE SW FOLLOWING THE PASSAGE OF THE RIDGE AXIS TO THE E. AS A COLD FRONT APPROACHES ON SUN...EXPECT SSW WINDS TO INCREASE UP TO 20-25 KTS. AFTER THE FRONT PASSES ON SUN NIGHT...WINDS WILL SHIFT TO THE W AND DIMINISH QUICKLY WITH THE APPROACH OF ANOTHER HI PRES ON MON. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER STORM WATCH FROM THIS EVENING THROUGH FRIDAY MORNING FOR MIZ002-009-010. WINTER STORM WARNING FROM 10 PM THIS EVENING TO NOON EDT FRIDAY FOR MIZ001-003-004-084. WINTER STORM WATCH FROM LATE TONIGHT THROUGH FRIDAY MORNING FOR MIZ005. LAKE SUPERIOR... GALE WARNING FROM 8 AM TO 8 PM EDT FRIDAY FOR LSZ251-267. GALE WARNING FROM 5 AM TO 5 PM EDT FRIDAY FOR LSZ249-250-266. GALE WARNING FROM 5 AM TO 2 PM EDT FRIDAY FOR LSZ244-245-248-264- 265. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KC AVIATION...07 MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
126 AM EDT THU APR 9 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 456 PM EDT WED APR 8 2015 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW PAIR OF SHORTWAVES RESPONSIBLE FOR THE LIGHT WINTRY MIX OF PCPN EARLIER TODAY NOW N AND E OF THE FCST AREA. ANOTHER SHORTWAVE MOVING FROM MANITOBA INTO NRN ONTARIO WON`T BE A FACTOR IN THE SHORT TERM WEATHER. FARTHER TO THE NW AND ALSO TO THE SW ARE 2 SHORTWAVES THAT WILL PLAY A ROLE IN WHAT WILL BECOME A QUICK HITTING SIGNIFICANT SPRING SNOWSTORM FOR PORTIONS OF UPPER MI THU NIGHT. ONE WAVE IS DROPPING INTO NRN MANITOBA AND THE SECOND WAVE IS OVER NV/UT. DETAILS ON THE HVY/WET SNOW CAN BE FOUND IN THE LONG TERM PORTION OF THE DISCUSSION BELOW. IN THE WAKE OF THE PCPN EARLIER TODAY...ABUNDANT CLOUD COVER DOMINATES THE UPPER GREAT LAKES...THOUGH NOT ALL OF THE LOW-LEVEL DRY AIR HAS BEEN ERODED...AND THERE IS STILL A FEED OF DRIER AIR AT THE LOW LEVELS FROM THE E. THIS HAS RESULTED IN SOME BREAKS DEVELOPING IN THE CLOUD COVER OVER UPPER MI IN THE LAST FEW HRS. WHERE SOME SUN HAS APPEARED...TEMPS HAVE RISEN INTO THE MID AND UPPER 40S. SHORTWAVE OVER NV/UT WILL SHIFT E AND RESULT IN SFC LOW PRES DEVELOPING OVER KS TONIGHT. FARTHER DOWNSTREAM...WATER VAPOR IMAGERY SUGGESTS MORE SUBTLE SHORTWAVE ENERGY LIFTING OUT OVER THE PLAINS. INCREASING WAA/ISENTROPIC ASCENT REGIME DOWNSTREAM OF THE MAIN SHORTWAVE TROF AND ENHANCED BY THE SUBTLE LEAD ENERGY WILL LEAD TO A AN AREA OF RAIN DEVELOPING AND SPREADING/EXPANDING NE INTO UPPER MI LATE TONIGHT INTO THU MORNING. BASED ON NRN EDGE OF THE POOL OF MUCAPE THAT LIFTS N INTO WI...NOT OUT OF THE QUESTION THAT THERE COULD BE FEW RUMBLES OF THUNDER. WHETHER TEMPS WILL BE BLO FREEZING WHEN PCPN BEGINS IS UNCERTAIN. USING MODEL CONSENSUS DIURNAL TEMP CURVE SUGGESTS THERE WILL BE AREAS WHERE TEMPS MAY BE JUST BLO FREEZING LATE TONIGHT/EARLY THU MORNING. HOWEVER...IF TEMPS DON`T FALL MUCH THIS EVENING...-FZRA POTENTIAL WILL BE DIMINISHED. AT THIS TIME...NOT EXPECTING SUFFICIENT ICE PROBLEMS ON ROADWAYS TO WARRANT ADVY ISSUANCE...BUT WILL CONTINUE TO HIGHLIGHT POTENTIAL OF SOME ICY CONDITIONS ON UNTREATED SURFACES LATE TONIGHT THRU MID MORNING THU. AFTER THE INITIAL SURGE OF WAA/ISENTROPIC ASCENT PCPN THAT SWEEPS NE LATE TONIGHT/THU MORNING...WILL PROBABLY SEE -RA DIMINISH OR BECOME MORE SCATTERED FOR A TIME LATE MORNING THRU MID AFTN OR SO AS WE AWAIT THE MAIN SHORTWAVE/STRONG DYNAMICS THAT WILL LIFT INTO THE UPPER LAKES THU NIGHT. PCPN IS LESS LIKELY TO DIMINISH OVER THE W WHERE 850MB TROF WILL EXTEND NE FROM THE APPROACHING LOW ACROSS WRN UPPER MI/WRN LAKE SUPERIOR. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 456 PM EDT WED APR 8 2015 COMPLEX FORECAST FRONT LOADED IN FIRST PERIOD OF LONG TERM. HIGH IMPACT WEATHER EXPECTED IN FORM OF RAIN CHANGING TO HEAVY SNOW. MAIN FACTORS COMING INTO FOCUS FOR THURSDAY NIGHT WEATHER. FIRST ALOFT...UPPER TROUGH OVER THE INTERIOR WESTERN CONUS THIS MORNING MOVES TO UPPER MISSISSIPPI RIVER VALLEY BY THURSDAY EVENING WHILE SHORTWAVE TROUGH DIGGING OVER NORTHERN SASKATCHEWAN THIS AFTN MOVES TO AXIS FM NORTHERN ONTARIO TO SOUTHERN MANITOBA. MAIN JET STREAK LIFTS OVER NORTHERN ONTARIO INTO QUEBEC ON THURSDAY EVENING WHILE ANOTHER JET WILL BE IN PROCESS OF EXITING TOWARD GREAT LAKES. AS THE PLAINS JET ARRIVES OVER THE GREAT LAKES THURSDAY EVENING...LEAD SHORTWAVE TROUGH IS FORECAST TO BECOME MORE NEGATIVELY TILTED AS IT LIFTS OVER THE UPPER GREAT LAKES. FOR MOST PART...LEAD WAVE DRIVES STRENGTH AND TRACK OF H85-H7 TROUGH AND PRIMARY SFC LOW...WHICH TRACKS FM IOWA AT 00Z FRIDAY TO NORTHERN LK MICHIGAN/NORTHERN LOWER MICHIGAN BY 06Z FRIDAY AND TO EAST OF SAULT STE MARIE BY 12Z FRIDAY. MODELS CONTINUE TO DIFFER ON WESTWARD EXTENT OF SFC LOW WHICH AFFECTS WHERE SWATH OF HEAVY QPF WELL OVER 1 INCH OCCURS ROUGHLY 00Z- 09Z ON FRIDAY. GIVEN VERY STRONG LIFT FM COUPLED JET STRUCTURE AND ENHANCED DIVERGENCE ALOFT AND PERSISTENT STRONG MID-LEVEL FGEN ALONG WITH COPIOUS DEEP MOISTURE THAT SHOULD BE ABLE TO TRANSLATE INTO THE DEEPENING SYSTEM AS MAIN INFLOW FOR TSRA SHOULD STAY FAR ENOUGH SOUTHEAST OF UPR MICHIGAN...TEND TO BELIEVE WETTER IDEAS OFFERED UP BY NAM/GFS SHOWING WELL OVER 1 INCH OF QPF. THOUGH ECMWF REMAINS DRIER...IT HAS SHOWN NOTEABLE TREND TOWARD STRONGER SYSTEM THE LAST DAY...SO THAT IS ENCOURAGING AT LEAST FROM THE FORECAST STANDPOINT. RUNNING WITH THE STRONGER/WETTER IDEA...MAIN STICKING POINT IS HOW QUICK THE RAIN CHANGES TO SNOW ON THURSDAY NIGHT. THE EARLIER THAT SWITCHOVER OCCURS...THE MORE THAT HEAVY QPF WILL GO TOWARD WET HEAVY SNOW ACCUMULATION. NAM SOUNDINGS SHOW WARM LAYER BTWN 900MB-800MB VCNTY OF L`ANSE TO WATERSMEET AT 00Z...THEN TO CRYSTAL FALLS AND MARQUETTE/HARVEY BY 03Z...BEFORE PUSHING THIS ON THE MUNISING AND ESCANABA BY 06Z. GFS AND GEM-REGIONAL ARE FARTHER WEST WITH WARM LAYER ALOFT...THOUGH THEY BOTH TRENDED A BIT EAST WITH TRACK OF SFC LOW ON THE 12Z RUNS. EXPECT HEAVY WET SNOW TO IMPACT PARTS OF WESTERN HALF OF UPR MICHIGAN. RETREATING WARM LAYER TO START COULD ALSO RESULT IN SLEET OF FZRA BEFORE CHANGE TO SNOW OCCURS. DECIDED TO ISSUE A WINTER STORM WATCH FOR WESTERN UPR MICHIGAN AS THERE SHOULD BE A NARROW STRIPE OF POSSIBLE VERY HEAVY WET SNOW THURSDAY NIGHT. GIVEN THE FORCING AND MOISTURE...LOCALIZED AMOUNTS OVER 8 INCHES SEEM POSSIBLE. MAIN QUANDARY WAS HOW FAR WEST AND EAST TO PUSH THE WATCH. LEANED A BIT TOWARD THE FARTHER EAST WARM LAYER IDEA WHICH RESULTED IN BRINGING THE WATCH AS FAR EAST AS MARQUETTE COUNTY. GIVEN DECENT CHANCE THAT PRECIP STAYS MAINLY RAIN WELL INTO THE EVENING FOR DICKINSON COUNTY LEFT THEM OUT FOR NOW...THOUGH COULD SEE NEED FOR ADVY FOR EVENTUALLY SLOPPY INCH OR TWO OF SNOW. CORRIDER OF HEAVY SNOW LIKELY WILL NOT MAKE IT AS FAR WEST AS IWD THOUGH LATEST HPC/WWD GRAPHICS STILL HIT FAR WEST FOR DECENT AMOUNT OF SNOW...BUT SINCE EASTERN PORTIONS OF GOGEBIC COUNTY INTO ONTONAGON COUNTY WOULD BE IMPACTED BY THE HEAVY SNOW WITH LATEST THINKING...INCLUDED GOGEBIC AS WELL. ESSENTIALLY SINCE THIS EVENT COULD BE VERY HIGH IMPACT DECIDED TO GO THIS ROUTE INSTEAD OF HAVING AN SPS OUT ONLY. WILL TRY TO CONVEY THE UNCERTAINTY DUE TO BOTH LOCATION OF HEAVIER SNOW AND PTYPE IN THE WSW STATEMENT. COORD WITH DLH AND GRB ON SNOW AMOUNTS/HEADLINE TIMING. LOW PRESSURE EXITS OVER EASTERN CANADA FRIDAY INTO FRIDAY NIGHT. LINGERING LOW-LEVEL MOISTURE/THERMAL TROUGHING AND ADDITIONAL FORCING FM THE NORTHERN STREAM WAVE DROPPING OVER THE AREA SUPPORTS CHANCE POPS FOR SNOW ON FRIDAY THOUGH MOST OF THE BIGGER SNOW WILL BE DONE BY DAYBREAK FRIDAY. KEPT WITH TEMPS MAINLY IN THE 30S ON FRIDAY. BREEZY CONDITIONS TOO...ESPECIALLY NEAR LK SUPERIOR IN THE MORNING HOURS. SFC RIDGE CROSSES FRIDAY NIGHT AND TEMPS COULD DIP INTO THE TEENS. EXPECT THIS TO BE THE LAST NIGHT THROUGH THE LONG TERM WHERE TEMPS DROP BLO FREEZING. TEMPS THIS WEEKEND LOOKS WARMER...MUCH WARMER. HIGH CLOUDS INCREASE LATE SATURDAY AND SATURDAY NIGHT AHEAD OF LOW PRESSURE TROUGH THAT MOVES FM SCNTRL CANADA TO NORTHERN PLAINS ON SUNDAY. MIXING HEIGHTS UP TO H85 WITH SW WINDS SUPPORT READINGS WELL INTO THE 50S. COOLEST TEMPS OVER EAST CWA WITH FLOW COMING OFF LK MICHIGAN. SOME LGT RAIN MAY DEVELOP AHEAD OF THE TROUGH ON SUNDAY AS GFS/ECMWF HAVE BEEN SHOWING FOR A WHILE NOW. EVEN SO...WARMER TEMPS ALOFT AND WARMER MIN TEMPS ON SATURDAY NIGHT ALLOW MANY AREAS TO REACH 60 DEGREES. SO ANY SNOW THAT DOES OCCUR THURSDAY NIGHT INTO FRIDAY SHOULD QUICKLY MELT THIS WEEKEND. FURTHER...ONCE THE TEMPS RISE ABOVE FREEZING ON SATURDAY THEY SHOULD REMAIN ABOVE FREEZING THROUGH MUCH OF NEXT WEEK SO WE SHOULD ALSO BEGIN TO MELT GOOD PORTION OF THE SNOWPACK THAT REMAINS OVER MAINLY NORTHERN UPPER MICHIGAN. SHOULD SEE AREA RIVERS AND STREAMS BEGIN TO RESPOND WITH THE SNOWMELT AND RUNOFF. ADDITIONAL RAINFALL POSSIBLE TUESDAY INTO WEDNESDAY AS A LOW PRESSURE SYSTEM AND WARM FRONT MOVE TOWARD THE NORTHERN PLAINS AND UPPER GREAT LAKES. ANY RAINFALL FM THIS SYSTEM WOULD ONLY ADD TO THE RUNOFF. SEEMS THAT AFTER THIS WINTRY SYSTEM WE MIGHT JUST SHIFT INTO THE MAIN SNOWMELT HYDROLOGY PERIOD OF THE SPRING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 126 AM EDT THU APR 9 2015 DETERIORATING CONDITIONS WILL CONTINUE OVERNIGHT AT ALL SITES AS MOISTURE AND PCPN SPREAD N LATE TONIGHT/EARLY THU. EXPECT CONDITIONS TO FALL TO IFR AT ALL TERMINALS. PCPN MAY BEGIN AS -FZRA FOR 2-3HRS AT KCMX/KSAW...BUT WILL CHANGE TO -RA AS TEMPS RISE DURING THE MORNING. KSAW IS LIKELY TO FALL TO LIFR BY MID MORNING. BY EVENING...VLIFR/LIFR CONDITIONS WILL BE AT ALL SITES WITH RAIN CHANGING OVER TO SNOW. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 456 PM EDT WED APR 8 2015 HIGH PRES MOVING E ACROSS QUEBEC AND LOW PRES DEVELOPING OVER THE CNTRL/SRN PLAINS WILL KEEP LAKE SUPERIOR UNDER GENERAL E TO NE WINDS OF 10-20KT THRU EARLY THU AFTN. AS THE LOW PRES TRACKS NE ACROSS NORTHERN LAKE MI THU EVENING AND INTO ONTARIO FRI MORNING...WINDS WILL BACK TO THE NW. OVER THE CNTRL PART OF LAKE SUPERIOR...THE WIND WILL ALSO INCREASE TO 20-30KT...AND OVER ERN LAKE SUPERIOR N TO NW GALES WILL DEVELOP BY FRI MORNING. WINDS WILL THEN DIMINISH W TO E FRI AFTN THRU FRI NIGHT AS HIGH PRES BUILDS ACROSS THE MISSISSIPPI VALLEY. LIGHT WINDS UNDER 20KT ARE EXPECTED SAT AS THE HIGH PRES RIDGE PASSES ACROSS THE WRN GREAT LAKES. AS THE RIDGE SHIFTS E AND A LOW PRES TROF MOVES E ACROSS THE NRN PLAINS...WINDS WILL THEN INCREASE SAT NIGHT/SUN...PROBABLY REACHING 15-25KT OR MORE OVER AT LEAST THE E HALF OF LAKE SUPERIOR ON SUN. THE TROF WILL CROSS THE UPPER GREAT LAKES SUN NIGHT...BRINGING A WIND SHIFT TO THE W. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER STORM WATCH FROM THIS EVENING THROUGH FRIDAY MORNING FOR MIZ001>005-009-010-084. LAKE SUPERIOR... GALE WATCH FROM FRIDAY MORNING THROUGH FRIDAY AFTERNOON FOR LSZ266-267. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...07 MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DULUTH MN
105 PM CDT THU APR 9 2015 .UPDATE... ISSUED AT 105 PM CDT THU APR 9 2015 UPDATED FOR AVIATION DISCUSSION BELOW UPDATE ISSUED AT 627 AM CDT THU APR 9 2015 && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 328 AM CDT THU APR 9 2015 A POSITIVELY TILTED UPPER LEVEL LONG WAVE TROF WAS MOVING TOWARD THE WESTERN GREAT LAKES AT 08Z. MEANWHILE...AN INVERTED SFC TROF WAS SETTING UP OVER THE FORECAST AREA. SEVERAL PIECES OF EMBEDDED ENERGY WILL MOVE OUT FROM THE BASE OF THE TROF AND AFFECT THE FORECAST AREA THROUGH THE DAY...EAST OF THE SFC TROF. ONE WAS MOVING THROUGH WI ATTM AND GENERATING SHOWERS OVER A PORTION OF NW WI INTO NORTH CENTRAL WI WITH ISOLD THUNDERSTORMS STAYING JUST TO THE SOUTH OF THE AREA. THIS WAS OCCURRING IN AN AREA OF WAA HELPING TO KEEP THE PCPN ALL LIQUID. THE LONG WAVE TROF WILL CONTINUE ON ITS PATH TOWARD THE FORECAST AREA TODAY. MEANWHILE...A SFC LOW CENTER WILL MOVE FROM SW IA TO SW WI. THIS WILL KEEP MAINLY THE SOUTHERN TWO THIRDS OF THE REGION ON THE NORTHERN FRINGE OF THE LOW AND IN THE BEST POSITION TO HAVE SOME PCPN OCCUR. AS THE AFOREMENTIONED PIECE OF ENERGY EXITS...THE NEXT ONE IS ALREADY MOVING INTO WESTERN IA AT 08Z. IT IS THIS PIECE OF ENERGY THAT WILL BRING PCPN TO MUCH OF THE AREA. LATEST FORECAST SOUNDINGS FROM THE RAP AND LOCAL WRF POINT TO PRIMARILY RAIN. HOWEVER...WITH SFC TEMPS HOVERING NEAR FREEZING...THERE IS A POSSIBILITY OF SNOW...MAINLY OVER THE ARROWHEAD. SINCE THIS SYSTEM IS FAIRLY WARM...SNOW AMOUNTS TODAY WILL BE FAIRLY LIGHT. NO FREEZING RAIN IS EXPECTED TODAY AS REFLECTED BY FORECAST SOUNDINGS AND HAVE REMOVED. TONIGHT...THE PCPN WILL BE FOCUSED ON THE EASTERN THIRD OF THE AREA...FROM THE PERIPHERY OF LAKE SUPERIOR THROUGH ALL OF NW WI. THE PCPN WILL BE ALL LIQUID EARLY THIS EVENING BEFORE MIXING WITH AND THEN QUICKLY CHANGING TO SNOW OVER NW WI. MODELS DISAGREE ON THE AMOUNT OF QPF...BUT HAVE LOWERED TO COME INTO LINE WITH THE LATEST TRENDS. MODELS ALSO DISAGREE ON THE AMOUNT OF FRONTOTGENETICAL FORCING THAT WILL MOVE OVER NW WI. NONETHELESS...HAVE HIGHEST POPS/QPF/SNOW AMOUNTS EAST OF U.S. HIGHWAY 63. COLDER AIR DOES NOT ARRIVE UNTIL AFTER 06Z FRIDAY...BUT SHOULD BE AN EFFICIENT SNOW PRODUCER. 1 TO 3 INCH AMOUNTS ARE LIKELY...BUT THERE COULD BE SOME ISOLD HIGHER AMOUNTS. NO FREEZING RAIN IS EXPECTED AND HAVE REMOVED. ON FRIDAY...THE SFC LOW MOVES INTO EASTERN CANADA WITH ONE MORE UPPER TROF CROSSING THE REGION. BEST FORCING WILL OCCUR IN THE MORNING...DIMINISHING IN THE AFTERNOON. HAVE ALIGNED THE POPS TO REFLECT THIS TREND. THE PTYPE WILL BE LIGHT SNOW IN THE EARLY MORNING CHANGING TO RAIN BY MID MORNING AS THE BOUNDARY LAYER WARMS WITH DIURNAL HEATING. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 328 AM CDT THU APR 9 2015 A RIDGE OF HIGH PRESSURE WILL BUILD OVER THE UPPER MIDWEST LATE THIS WEEK AND EARLY INTO THE WEEKEND WITH WARMING TEMPERATURES AND INITIALLY QUIET WEATHER CONDITIONS. AS THE SFC HIGH AND UPPER RIDGE TRANSLATE EWD ON SATURDAY A STRONG RETURN FLOW FROM THE SW WILL DEVELOP AND USHER IN A WARM AND MOIST AIR MASS...WHICH WILL EVENTUALLY INTERACT WITH AN INCOMING S/W FROM THE FRONT RANGE OF THE NRN ROCKIES LATE SATURDAY AND SUNDAY TO PRODUCE RAIN SHOWERS AND POSSIBLY A FEW WEAK THUNDERSTORMS AS WELL. STRONG WAA AHEAD OF THE FRONT SAT NIGHT/SUN MORNING WILL AID IN THE DESTABILIZATION OF THE BOUNDARY LAYER ENOUGH TO TRIGGER CONVECTIVE DEVELOPMENT ACROSS THE NORTHLAND. A SLIGHTLY COOLER AIR MASS WILL SETTLE IN OVER THE REGION BEHIND THE FRONT LATE SUN AND EARLY MONDAY BEFORE ANOTHER WARM RIDGE BUILDS IN ACROSS THE MIDWEST INTO TUESDAY AND THE NEXT SYSTEM USHERS IN ADDITIONAL CHANCES FOR SHOWERS THROUGH THE MIDDLE TO LATTER HALF OF THE WEEK. ISOLATED STORMS WILL ALSO BE POSSIBLE. RELATIVELY WARM TEMPERATURES ARE EXPECTED THIS WEEKEND AND EARLY NEXT WEEK WITH HIGHS IN THE 50S AND 60S...AND OVERNIGHT LOWS IN THE 30S AND 40S. ANOTHER PERIOD OF PERSISTENT NE WINDS OFF LAKE SUPERIOR IS EXPECTED TO DEVELOP TUE THROUGH MOST OF NEXT WEEK...WHICH WILL KEEP TEMPERATURES AROUND THE PERIPHERY OF LAKE SUPERIOR ON THE COOL SIDE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 105 PM CDT THU APR 9 2015 EXPECT LOW END MVFR AND IFR CONDITIONS TO CONTINUE THROUGHOUT THE DAY AS LOW CLOUDS AND LIGHT PRECIP MOVE INTO THE NORTHLAND AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM. THE EXCEPTION WILL BE THE KINL SITE... WHICH HAS ALREADY ESCAPED THE CLOUD DECK AND WILL REMAIN IN VFR TODAY. CIGS/VIS SHOULD IMPROVE TO VFR THIS EVENING... BEFORE A COLD FRONT FROM CANADA MOVES SOUTHEAST ACROSS THE NORTHLAND IN THE EARLY MORNING HOURS AND LOWERS CIGS/VIS AGAIN. EXPECT GENERALLY MVFR CONDITIONS TOMORROW MORNING BEFORE IMPROVEMENT IN THE AFTERNOON. THE FRONT WILL BRING A CHANCE OF LIGHT SNOW BEFORE 12Z... WHICH WILL CHANGE OVER TO LIGHT RAIN OR DRIZZLE AFTER SUNRISE. WINDS WILL SHIFT TO THE NORTH AND BECOME GUSTY IN THE WAKE OF THE COLD FRONT PASSAGE. && .PRELIMINARY POINT TEMPS/POPS... DLH 41 32 48 30 / 70 20 20 10 INL 50 30 48 28 / 10 40 10 0 BRD 49 31 51 29 / 60 20 20 10 HYR 42 31 47 27 / 90 80 30 10 ASX 38 31 45 29 / 100 70 30 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...GSF LONG TERM...BJT AVIATION...MCLOVIN
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
627 AM CDT THU APR 9 2015 .UPDATE... ISSUED AT 627 AM CDT THU APR 9 2015 UPDATED FOR AVIATION DISCUSSION. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 328 AM CDT THU APR 9 2015 A POSITIVELY TILTED UPPER LEVEL LONG WAVE TROF WAS MOVING TOWARD THE WESTERN GREAT LAKES AT 08Z. MEANWHILE...AN INVERTED SFC TROF WAS SETTING UP OVER THE FORECAST AREA. SEVERAL PIECES OF EMBEDDED ENERGY WILL MOVE OUT FROM THE BASE OF THE TROF AND AFFECT THE FORECAST AREA THROUGH THE DAY...EAST OF THE SFC TROF. ONE WAS MOVING THROUGH WI ATTM AND GENERATING SHOWERS OVER A PORTION OF NW WI INTO NORTH CENTRAL WI WITH ISOLD THUNDERSTORMS STAYING JUST TO THE SOUTH OF THE AREA. THIS WAS OCCURRING IN AN AREA OF WAA HELPING TO KEEP THE PCPN ALL LIQUID. THE LONG WAVE TROF WILL CONTINUE ON ITS PATH TOWARD THE FORECAST AREA TODAY. MEANWHILE...A SFC LOW CENTER WILL MOVE FROM SW IA TO SW WI. THIS WILL KEEP MAINLY THE SOUTHERN TWO THIRDS OF THE REGION ON THE NORTHERN FRINGE OF THE LOW AND IN THE BEST POSITION TO HAVE SOME PCPN OCCUR. AS THE AFOREMENTIONED PIECE OF ENERGY EXITS...THE NEXT ONE IS ALREADY MOVING INTO WESTERN IA AT 08Z. IT IS THIS PIECE OF ENERGY THAT WILL BRING PCPN TO MUCH OF THE AREA. LATEST FORECAST SOUNDINGS FROM THE RAP AND LOCAL WRF POINT TO PRIMARILY RAIN. HOWEVER...WITH SFC TEMPS HOVERING NEAR FREEZING...THERE IS A POSSIBILITY OF SNOW...MAINLY OVER THE ARROWHEAD. SINCE THIS SYSTEM IS FAIRLY WARM...SNOW AMOUNTS TODAY WILL BE FAIRLY LIGHT. NO FREEZING RAIN IS EXPECTED TODAY AS REFLECTED BY FORECAST SOUNDINGS AND HAVE REMOVED. TONIGHT...THE PCPN WILL BE FOCUSED ON THE EASTERN THIRD OF THE AREA...FROM THE PERIPHERY OF LAKE SUPERIOR THROUGH ALL OF NW WI. THE PCPN WILL BE ALL LIQUID EARLY THIS EVENING BEFORE MIXING WITH AND THEN QUICKLY CHANGING TO SNOW OVER NW WI. MODELS DISAGREE ON THE AMOUNT OF QPF...BUT HAVE LOWERED TO COME INTO LINE WITH THE LATEST TRENDS. MODELS ALSO DISAGREE ON THE AMOUNT OF FRONTOTGENETICAL FORCING THAT WILL MOVE OVER NW WI. NONETHELESS...HAVE HIGHEST POPS/QPF/SNOW AMOUNTS EAST OF U.S. HIGHWAY 63. COLDER AIR DOES NOT ARRIVE UNTIL AFTER 06Z FRIDAY...BUT SHOULD BE AN EFFICIENT SNOW PRODUCER. 1 TO 3 INCH AMOUNTS ARE LIKELY...BUT THERE COULD BE SOME ISOLD HIGHER AMOUNTS. NO FREEZING RAIN IS EXPECTED AND HAVE REMOVED. ON FRIDAY...THE SFC LOW MOVES INTO EASTERN CANADA WITH ONE MORE UPPER TROF CROSSING THE REGION. BEST FORCING WILL OCCUR IN THE MORNING...DIMINISHING IN THE AFTERNOON. HAVE ALIGNED THE POPS TO REFLECT THIS TREND. THE PTYPE WILL BE LIGHT SNOW IN THE EARLY MORNING CHANGING TO RAIN BY MID MORNING AS THE BOUNDARY LAYER WARMS WITH DIURNAL HEATING. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 328 AM CDT THU APR 9 2015 A RIDGE OF HIGH PRESSURE WILL BUILD OVER THE UPPER MIDWEST LATE THIS WEEK AND EARLY INTO THE WEEKEND WITH WARMING TEMPERATURES AND INITIALLY QUIET WEATHER CONDITIONS. AS THE SFC HIGH AND UPPER RIDGE TRANSLATE EWD ON SATURDAY A STRONG RETURN FLOW FROM THE SW WILL DEVELOP AND USHER IN A WARM AND MOIST AIR MASS...WHICH WILL EVENTUALLY INTERACT WITH AN INCOMING S/W FROM THE FRONT RANGE OF THE NRN ROCKIES LATE SATURDAY AND SUNDAY TO PRODUCE RAIN SHOWERS AND POSSIBLY A FEW WEAK THUNDERSTORMS AS WELL. STRONG WAA AHEAD OF THE FRONT SAT NIGHT/SUN MORNING WILL AID IN THE DESTABILIZATION OF THE BOUNDARY LAYER ENOUGH TO TRIGGER CONVECTIVE DEVELOPMENT ACROSS THE NORTHLAND. A SLIGHTLY COOLER AIR MASS WILL SETTLE IN OVER THE REGION BEHIND THE FRONT LATE SUN AND EARLY MONDAY BEFORE ANOTHER WARM RIDGE BUILDS IN ACROSS THE MIDWEST INTO TUESDAY AND THE NEXT SYSTEM USHERS IN ADDITIONAL CHANCES FOR SHOWERS THROUGH THE MIDDLE TO LATTER HALF OF THE WEEK. ISOLATED STORMS WILL ALSO BE POSSIBLE. RELATIVELY WARM TEMPERATURES ARE EXPECTED THIS WEEKEND AND EARLY NEXT WEEK WITH HIGHS IN THE 50S AND 60S...AND OVERNIGHT LOWS IN THE 30S AND 40S. ANOTHER PERIOD OF PERSISTENT NE WINDS OFF LAKE SUPERIOR IS EXPECTED TO DEVELOP TUE THROUGH MOST OF NEXT WEEK...WHICH WILL KEEP TEMPERATURES AROUND THE PERIPHERY OF LAKE SUPERIOR ON THE COOL SIDE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 627 AM CDT THU APR 9 2015 LOW END MVFR AND IFR CEILINGS WILL PERSIST THROUGH TODAY...WITH SCATTERED LIFR CIGS ACROSS THE NRN TERMINALS THIS MORNING. RAIN SHOWERS...WITH EMBEDDED FZDZ/IP/SN WILL MOVE IN FROM THE SOUTH THIS MORNING AND SPREAD TO THE ENE THROUGH THE AFTERNOON. THE HYR TERMINAL WILL SEE THE MOST PRECIPITATION TODAY AND TONIGHT WITH MAINLY RAIN THROUGH THE DAY AND A CHANGE OVER TO ALL SNOW THIS EVENING AND TONIGHT. CONDITIONS WILL IMPROVE TO VFR FROM THE NW TONIGHT...WITH A BRIEF PERIOD OF IFR/MVFR VSBYS IN LIGHT FOG BEHIND THE FRONT. NE WINDS WILL CONTINUE MOST OF TODAY WITH A SHIFT TO THE NW TONIGHT. && .PRELIMINARY POINT TEMPS/POPS... DLH 41 32 48 30 / 70 20 20 10 INL 50 30 48 28 / 10 40 10 0 BRD 49 31 51 29 / 60 20 20 10 HYR 42 31 47 27 / 90 80 30 10 ASX 38 31 45 29 / 100 70 30 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...GSF LONG TERM...BJT AVIATION...BJT
AREA FORECAST DISCUSSION
NWS DULUTH MN
328 AM CDT THU APR 9 2015 .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 328 AM CDT THU APR 9 2015 A POSITIVELY TILTED UPPER LEVEL LONG WAVE TROF WAS MOVING TOWARD THE WESTERN GREAT LAKES AT 08Z. MEANWHILE...AN INVERTED SFC TROF WAS SETTING UP OVER THE FORECAST AREA. SEVERAL PIECES OF EMBEDDED ENERGY WILL MOVE OUT FROM THE BASE OF THE TROF AND AFFECT THE FORECAST AREA THROUGH THE DAY...EAST OF THE SFC TROF. ONE WAS MOVING THROUGH WI ATTM AND GENERATING SHOWERS OVER A PORTION OF NW WI INTO NORTH CENTRAL WI WITH ISOLD THUNDERSTORMS STAYING JUST TO THE SOUTH OF THE AREA. THIS WAS OCCURRING IN AN AREA OF WAA HELPING TO KEEP THE PCPN ALL LIQUID. THE LONG WAVE TROF WILL CONTINUE ON ITS PATH TOWARD THE FORECAST AREA TODAY. MEANWHILE...A SFC LOW CENTER WILL MOVE FROM SW IA TO SW WI. THIS WILL KEEP MAINLY THE SOUTHERN TWO THIRDS OF THE REGION ON THE NORTHERN FRINGE OF THE LOW AND IN THE BEST POSITION TO HAVE SOME PCPN OCCUR. AS THE AFOREMENTIONED PIECE OF ENERGY EXITS...THE NEXT ONE IS ALREADY MOVING INTO WESTERN IA AT 08Z. IT IS THIS PIECE OF ENERGY THAT WILL BRING PCPN TO MUCH OF THE AREA. LATEST FORECAST SOUNDINGS FROM THE RAP AND LOCAL WRF POINT TO PRIMARILY RAIN. HOWEVER...WITH SFC TEMPS HOVERING NEAR FREEZING...THERE IS A POSSIBILITY OF SNOW...MAINLY OVER THE ARROWHEAD. SINCE THIS SYSTEM IS FAIRLY WARM...SNOW AMOUNTS TODAY WILL BE FAIRLY LIGHT. NO FREEZING RAIN IS EXPECTED TODAY AS REFLECTED BY FORECAST SOUNDINGS AND HAVE REMOVED. TONIGHT...THE PCPN WILL BE FOCUSED ON THE EASTERN THIRD OF THE AREA...FROM THE PERIPHERY OF LAKE SUPERIOR THROUGH ALL OF NW WI. THE PCPN WILL BE ALL LIQUID EARLY THIS EVENING BEFORE MIXING WITH AND THEN QUICKLY CHANGING TO SNOW OVER NW WI. MODELS DISAGREE ON THE AMOUNT OF QPF...BUT HAVE LOWERED TO COME INTO LINE WITH THE LATEST TRENDS. MODELS ALSO DISAGREE ON THE AMOUNT OF FRONTOTGENETICAL FORCING THAT WILL MOVE OVER NW WI. NONETHELESS...HAVE HIGHEST POPS/QPF/SNOW AMOUNTS EAST OF U.S. HIGHWAY 63. COLDER AIR DOES NOT ARRIVE UNTIL AFTER 06Z FRIDAY...BUT SHOULD BE AN EFFICIENT SNOW PRODUCER. 1 TO 3 INCH AMOUNTS ARE LIKELY...BUT THERE COULD BE SOME ISOLD HIGHER AMOUNTS. NO FREEZING RAIN IS EXPECTED AND HAVE REMOVED. ON FRIDAY...THE SFC LOW MOVES INTO EASTERN CANADA WITH ONE MORE UPPER TROF CROSSING THE REGION. BEST FORCING WILL OCCUR IN THE MORNING...DIMINISHING IN THE AFTERNOON. HAVE ALIGNED THE POPS TO REFLECT THIS TREND. THE PTYPE WILL BE LIGHT SNOW IN THE EARLY MORNING CHANGING TO RAIN BY MID MORNING AS THE BOUNDARY LAYER WARMS WITH DIURNAL HEATING. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 328 AM CDT THU APR 9 2015 A RIDGE OF HIGH PRESSURE WILL BUILD OVER THE UPPER MIDWEST LATE THIS WEEK AND EARLY INTO THE WEEKEND WITH WARMING TEMPERATURES AND INITIALLY QUIET WEATHER CONDITIONS. AS THE SFC HIGH AND UPPER RIDGE TRANSLATE EWD ON SATURDAY A STRONG RETURN FLOW FROM THE SW WILL DEVELOP AND USHER IN A WARM AND MOIST AIR MASS...WHICH WILL EVENTUALLY INTERACT WITH AN INCOMING S/W FROM THE FRONT RANGE OF THE NRN ROCKIES LATE SATURDAY AND SUNDAY TO PRODUCE RAIN SHOWERS AND POSSIBLY A FEW WEAK THUNDERSTORMS AS WELL. STRONG WAA AHEAD OF THE FRONT SAT NIGHT/SUN MORNING WILL AID IN THE DESTABILIZATION OF THE BOUNDARY LAYER ENOUGH TO TRIGGER CONVECTIVE DEVELOPMENT ACROSS THE NORTHLAND. A SLIGHTLY COOLER AIR MASS WILL SETTLE IN OVER THE REGION BEHIND THE FRONT LATE SUN AND EARLY MONDAY BEFORE ANOTHER WARM RIDGE BUILDS IN ACROSS THE MIDWEST INTO TUESDAY AND THE NEXT SYSTEM USHERS IN ADDITIONAL CHANCES FOR SHOWERS THROUGH THE MIDDLE TO LATTER HALF OF THE WEEK. ISOLATED STORMS WILL ALSO BE POSSIBLE. RELATIVELY WARM TEMPERATURES ARE EXPECTED THIS WEEKEND AND EARLY NEXT WEEK WITH HIGHS IN THE 50S AND 60S...AND OVERNIGHT LOWS IN THE 30S AND 40S. ANOTHER PERIOD OF PERSISTENT NE WINDS OFF LAKE SUPERIOR IS EXPECTED TO DEVELOP TUE THROUGH MOST OF NEXT WEEK...WHICH WILL KEEP TEMPERATURES AROUND THE PERIPHERY OF LAKE SUPERIOR ON THE COOL SIDE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1223 AM CDT THU APR 9 2015 A SURFACE LOW WAS LOCATED IN THE WESTERN KS/EASTERN CO REGION LATE THIS EVENING AND IS FORECAST TO LIFT INTO IOWA THURSDAY MORNING. WAA AHEAD OF THIS LOW WILL AID IN DEVELOPING PRECIP ACROSS THE NORTHLAND TONIGHT THROUGH THURSDAY NIGHT. SHOWERS WERE ALREADY MOVING ACROSS NORTHERN WISCONSIN AND WE EXPECT COVERAGE TO INCREASE OVERNIGHT. A WINTRY MIX WILL OCCUR OVER FAR NORTHERN WISCONSIN INTO PORTIONS OF NORTHEAST MINNESOTA...WITH MAINLY RAIN AT KHYR UNTIL LATE THURSDAY AFTERNOON. MVFR/IFR CONDITIONS WILL PREVAIL THROUGH THURSDAY MORNING...THEN SOME CLEARING WILL OCCUR OVER WESTERN TAF SITES...AND GRADUALLY MOVE EAST TO KHIB/KDLH. ANOTHER POTENT SHORTWAVE WILL MOVE SOUTH THURSDAY NIGHT AND BRING SOME SNOW SHOWERS WITH IT. WE ADDED A VCSH AT KINL LATE IN THE PERIOD. FOG WILL BE POSSIBLE AROUND LAKE SUPERIOR...ESPECIALLY AT KDLH. WE EXPECTED LOWER VSBYS TO OCCUR BY NOW BUT HAVE YET TO SEE THAT. WE WILL DELAY THE LOWER VSBYS UNTIL LATE TONIGHT. && .PRELIMINARY POINT TEMPS/POPS... DLH 41 32 48 30 / 70 20 20 10 INL 50 30 48 28 / 10 40 10 0 BRD 49 31 51 29 / 60 20 20 10 HYR 42 31 47 27 / 90 80 30 10 ASX 38 31 45 29 / 100 70 30 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...GSF LONG TERM...BJT AVIATION...MELDE
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
916 AM MDT THU APR 9 2015 .UPDATE... MADE SOME MINOR TWEAKS FOR THE WEAK ECHOS ACROSS GLASGOW/S AREA...BUT KEPT POPS NO HIGHER THAN 14 GIVEN THAT THE HRRR DOES NOT HANG ON TO PRECIP VERY LONG. REIMER && .SHORT TERM...VALID FOR TDY AND FRI... WEAK NORTHERLY FLOW ALOFT WILL TAKE OVER TODAY AS THE SYSTEM THAT IMPACTED THE SOUTHEAST MOVES AWAY. LIGHT WINDS THIS MORNING COULD ALLOW FOR FOG FORMATION...SO WILL LET THAT PART OF THE FORECAST RIDE FOR THE EARLY PART OF THE DAY. WEAK CIRCULATION OVER NORTHERN IDAHO WILL SWING ACROSS THE SOUTHWEST MOUNTAINS THIS AFTERNOON AND EVENING. ENOUGH LINGERING MOISTURE AND WEAK INSTABILITY FOR A FEW SHOWERS OVER THE HIGHER TERRAIN DURING THE PERIOD. THE MAIN PART OF THE TROUGH HOUSING THE WEAK ENERGY OF TODAY IS PROGGED TO PUSH ACROSS THE AREA FRIDAY. ENOUGH WEAK INSTABILITY TO MENTION SHOWER CHANCES OVER THE WEST. LOW LEVEL DOWNSLOPE FLOW WILL ALLOW FOR WARMER TEMPERATURES FRIDAY AFTERNOON. TWH .LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED... GENERALLY FEW CHANGES TO THE EXTENDED FORECAST PERIOD...WITH GREATEST CONCERN THROUGH THE PERIOD CONTINUING TO BE IMPRESSIVE UPPER LEVEL LOW PRESSURE SYSTEM PROGGED TO MOVE ACROSS THE REGION THROUGH THE LATTER HALF OF NEXT WEEK...AT LEAST. UNTIL THEN...THE PATTERN REMAINS SOMEWHAT UNSETTLED AND PROGRESSIVE. THE PERIOD BEGINS WITH A SHORTWAVE AND ASSOCIATED COLD FRONT CROSSING THE REGION SATURDAY EVENING/NIGHT. SATURDAY CONTINUES TO LOOK LIKE THE WARMEST DAY OF THE PERIOD...IN PREFRONTAL ENVIRONMENT...WITH TEMPS AROUND 70. EXPECT TO SEE SCATTERED SHOWERS ALONG THE FRONT...BUT NOTHING INDICATING WIDESPREAD PRECIP. DRY WITH GUSTY NORTHWEST WINDS WILL FOLLOW BEHIND THE SYSTEM FOR SUNDAY. WILL NEED TO KEEP A CLOSE EYE ON THESE DAYS FOR ANY FIRE WEATHER CONCERNS. WINDS WILL BE STRONG AND GUSTY AT TIMES AND RH VALUES LOOK LIKE WILL BE BACK IN TEENS. DRY CONDITIONS PERSIST THROUGH MONDAY AND INTO TUESDAY...AS SOUTHWEST FLOW SETS UP AHEAD OF APPROACHING TROF...DEVELOPING ALONG THE WEST COAST. THERE ARE A FEW DIFFERENCES IN THE MODELS...WITH ECMWF BRINGING A WAVE INTO THE REGION ON TUESDAY AHEAD OF THE MAIN TROF...WHILE GFS REMAINS DRY. HAVE KEPT SLIGHT POPS IN PLACE THROUGH THIS PERIOD...ALTHOUGH MAY MAINLY SERVE TO RECHARGE ATMOSPHERE AFTER FEW DAYS OF DRYING OUT. MODEL COME BACK TOGETHER A BIT BETTER BY TUESDAY NIGHT...WITH LARGE UPPER LEVEL LOW PRESSURE SYSTEM MOVING INTO THE REGION. TRACK...SPEED...PRECIP AMOUNTS ARE STILL UNCERTAIN...BUT MODELS HAVE BEEN VERY CONSISTENT WITH THIS SYSTEM TRACKING ACROSS THE REGION THROUGH THE END OF THE WORK WEEK...SO HAVE KEPT HIGH POPS IN PLACE THROUGH THE PERIOD. TEMPS ARE ALSO UNCERTAIN DUE TO POTENTIAL CHANGES IN TRACK OF THE SYSTEM...SO WILL HAVE TO BE MONITORED CLOSELY. AAG && .AVIATION... VFR CONDITIONS SHOULD PREVAIL TODAY AT ALL TERMINALS. THE THREAT OF FOG OVER THE EASTERN TERMINALS HAS DIMINISHED. LATER TODAY THERE IS A SLIGHT CHANCE OF A MOUNTAIN SNOW SHOWER...SO MOUNTAIN OBSCURATION RULES MAY APPLY. SINGER && .PRELIMINARY POINT TEMP/POPS... TDY FRI SAT SUN MON TUE WED ------------------------------------------------------- BIL 057 036/065 040/069 040/061 033/064 039/060 038/052 0/B 01/B 02/W 31/N 11/B 33/W 45/W LVM 055 033/061 037/063 034/056 030/059 035/058 034/049 1/B 13/W 03/W 31/N 12/W 33/W 55/W HDN 059 031/067 035/071 038/062 031/066 036/065 034/053 0/B 01/B 02/W 31/N 11/B 33/W 45/W MLS 057 032/065 037/070 039/061 032/065 038/065 038/053 1/B 00/U 02/W 31/N 11/B 22/W 45/W 4BQ 053 029/064 035/070 038/060 031/066 037/067 036/054 0/B 00/B 01/U 31/B 11/B 32/W 45/W BHK 053 028/062 033/068 037/059 030/064 036/067 035/056 1/B 00/U 01/U 21/N 11/B 22/W 45/W SHR 052 027/061 033/066 036/058 031/064 035/064 034/051 0/B 00/B 01/B 31/B 11/B 33/W 45/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
957 PM CDT FRI APR 10 2015 .UPDATE... ISSUED AT 958 PM CDT FRI APR 10 2015 JUST PUBLISHED A RATHER "COSMETIC" UPDATE FOR THE REMAINDER OF THE OVERNIGHT HOURS (THROUGH 12Z/7AM)...WITH VERY LITTLE NOTICEABLE CHANGE FROM THE PREVIOUS FORECAST. FOR THE MOST PART...THE OVERNIGHT HOURS SHOULD FEATURE NO WORSE THAN MOSTLY CLEAR-PARTLY CLOUDY SKIES UNDER PRIMARILY PASSING THIN HIGH CLOUDS. BREEZES WILL AVERAGE 5-10 MPH FROM THE SOUTH...AS OVERNIGHT LOWS ARE EXPECTED TO DROP NO LOWER THAN THE 39-44 RANGE FOR THE MAJORITY OF THE CWA. REALLY THE ONLY POSSIBLE "CAVEAT" THROUGH SUNRISE INVOLVES WHETHER OR NOT SOME SPRINKLES OR LIGHT RAIN SHOWERS COULD POSSIBLY BRUSH INTO THE FAR SOUTHWEST EDGES OF THE CWA (NAMELY THE ROOKS COUNTY KS AREA) SOMETIME AFTER 4 AM OR SO. WHILE THIS IS NOT OUT OF THE QUESTION...DID NOT FEEL THERE WAS ENOUGH EVIDENCE IN THE LATEST MODEL DATA (INCLUDING RAP 13/HRRR) TO "RUIN" THE CURRENTLY-DRY OVERNIGHT FORECAST...AS CERTAINLY THE BETTER CHANCES FOR SPOTTY RAIN LATE SHOULD FOCUS AT LEAST SLIGHTLY WEST AND/OR SOUTHWEST OF THE CWA. MADE NO CHANGES TO THE POST-SUNRISE FORECAST AT THIS TIME...BUT IT STILL APPEARS THE MAJORITY OF THE CWA SHOULD GET THROUGH THE DAYLIGHT HOURS DRY...WITH ANY LIMITED SHOWER/THUNDERSTORM POTENTIAL PRIMARILY FOCUSED WITHIN SOUTHERN AND/OR WESTERN PORTIONS OF THE LOCAL AREA. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 333 PM CDT FRI APR 10 2015 SATELLITE AND OBSERVATIONS SHOW MOSTLY SUNNY SKIES ACROSS THE AREA WITH A FEW CIRRUS IN THE SOUTHERN PART OF THE FORECAST AREA. SURFACE ANALYSIS SHOWS A WEAK HIGH PRESSURE SYSTEM ACROSS THE AREA. THE SURFACE HIGH ACROSS THE AREA WILL CONTINUE TO MOVE TO THE EAST THIS AFTERNOON AND EVENING. WINDS ARE EXPECTED TO TURN TO THE SOUTH DURING THE NIGHT. AN UPPER LEVEL WAVE APPROACHES THE AREA LATE TONIGHT. EXPECT MOSTLY CLEAR SKIES TO CONTINUE THROUGH THE NIGHT. ON SATURDAY...THE UPPER LEVEL WAVE WILL CONTINUE TO MOVE THROUGH THE AREA. WITH THE SOUTH WINDS THROUGH THE NIGHT...THE LOW LEVEL MOISTURE WILL INCREASE. WITH THE INCREASE IN MOISTURE THERE WILL BE AN INCREASE IN INSTABILITY. MUCAPE INCREASES TO NEARLY 1500 J/KG IN THE SOUTHWEST PART OF THE AREA. HAVE BACKED OFF A LITTLE BRINGING THE PRECIPITATION INTO THE AREA ON SATURDAY. HAVE KEPT A LITTLE IN THE FAR SOUTH IN THE MORNING...BUT EXPECT THAT MOST OF THE PRECIPITATION WILL BE DURING THE AFTERNOON. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 333 PM CDT FRI APR 10 2015 UNSETTLED WEATHER THROUGH THE PERIOD WITH PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS. NO WIDESPREAD RAINS ON THE HORIZON...BUT SCATTERED SHOWERS AND STORMS POSSIBLE SUNDAY AND AGAIN WEDNESDAY AND THURSDAY. POTENTIAL FIRE WEATHER CONCERNS TUESDAY AFTERNOON OVER THE WEST DUE TO LOW HUMIDITIES AND STRONG WINDS. TEMPERATURES WILL BE SEASONABLE...EVEN ABOUT 10 DEGREES ABOVE NORMAL FOR MOST DAYS IN THE PERIOD. THE NORMAL IS 60 TO 65 FOR HIGH TEMPS AND AROUND FREEZING FOR LOW TEMPS. PATTERN-WISE...A ZONAL FLOW RETURNS WITH PERIODIC WAVES MOVING THROUGH. THE NORMAL RESULTING WEATHER WITH THIS TYPE PATTERN IS ABOVE NORMAL TEMPS AND GENERALLY DRY WEATHER...ALTHOUGH PERIODIC WAVES BRING FRONTS THROUGH THAT ACT AS A FOCUS FOR SHOWERS AND THUS A FEW PLACES MAY GET SOME RAIN ON AND OFF. MODELS...THE EUROPEAN AND GFS ARE IN PHASE THE FIRST FEW DAYS...BUT AFTER WEDNESDAY THE GFS DEVELOPS SYSTEMS FASTER. PREFER THE TIMING OF THE SLOWER EUROPEAN BASED ON EXPERIENCE AND PATTERN RECOGNITION. && .AVIATION...(FOR THE 00Z KGRI/KEAR TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 627 PM CDT FRI APR 10 2015 VFR CONDITIONS TO CONTINUE THROUGH THE NEXT 24 HOURS. A SUBTLE INCREASE IN CLOUD COVER MAY BE NOTED DURING THE TAF PERIOD...BUT NOTHING BELOW 15000FT AGL IS CURRENTLY EXPECTED. THE SURFACE WIND WILL REMAIN FROM THE SOUTH FOR THE MOST PART DURING THE NEXT 24 HOURS...SUSTAINED AT AROUND 08KTS TONIGHT...BUT INCREASING TO AROUND 16KTS AND GUSTING TO AROUND 25KTS DURING THE DAY SATURDAY. VISIBILITY RESTRICTION IS NOT EXPECTED THROUGH THE NEXT 24 HOURS. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...PFANNKUCH SHORT TERM...JCB LONG TERM...EDDY AVIATION...BRYANT
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
100 PM CDT THU APR 9 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 343 AM CDT THU APR 9 2015 TODAY AND TONIGHT...THE RAP MODEL AND HRRR SEEM TO HAVE A GOOD HANDLE ON THE RAIN SNOW LINE ADVANCING SOUTH AND EAST THROUGH THE PANHANDLE THIS MORNING. SNOW IS UNDERWAY FROM HEMINGFORD TO SCOTTSBLUFF TO HARRISBURG IN BANNER COUNTY. THE RAP AND SFC OBSERVATIONS SHOW THE RAIN TO SNOW CHANGING OVER WHEN H700MB TEMPERATURES REACH -6C OR COLDER AND THE MODEL FORECAST IS FOR -8C ACROSS ALL OF THE FCST AREA. THIS SUGGESTS A RAIN SNOW MIX WILL DEVELOP ACROSS MOST OF THE FCST AREA AND ALL SNOW ALONG AND NORTH OF NEBRASKA HIGHWAY 2. THE RAP ALSO SHOWS AROUND 0.25 INCHES OF RAINFALL THIS MORNING WHICH COULD PRODUCE AROUND 2 INCHES OF SNOW IN THE SANDHILLS. THE SATELLITE WATER VAPOR AND RAP40 ANALYZE A DEFORMATION ZONE UNDERWAY ACROSS THE PANHANDLE THIS MORNING AND THIS FEATURE SHOULD MOVE DUE EAST AND BE LOCATED EAST OF HIGHWAY 83 BY 18Z LENDING CLARITY TO THE PRECIPITATION FORECAST. THE RAIN AND SNOW SHOULD EXIT THE FCST AREA AROUND 21Z WITH CLEARING SKIES MOVING IN FROM THE NORTHWEST AT THE SAME TIME. THE RAP SUGGESTS HIGHS IN THE LOWER 40S WHICH WAS MARKED UP TO UPPER 40S TO NEAR 50 IN SOME AREAS. THE WRN SANDHILLS WILL LIKELY EXPERIENCE HIGHS IN THE LOWER 40S AS PROGGED BY THE RAP. H850MB WINDS INCREASE TO 40 KTS FOR NORTH WINDS 25 TO 30 MPH. HIGH PRESSURE WILL MOVE OVERHEAD TONIGHT WITH GENERALLY CLEAR SKIES FOR LOWS IN THE UPPER 20S TO LOWER 30S. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 343 AM CDT THU APR 9 2015 RETURN FLOW AIDED BY THE DEVELOPMENT OF A LEE SIDE TROUGH ON FRIDAY WILL ADVECT MOISTURE FROM THE GULF COAST NORTHWARD ONTO THE HIGH PLAINS. AS THE MOISTURE INCREASES...THERE ARE INDICATIONS OF A WEAK ATMOSPHERIC DISTURBANCE PASSING THROUGH THE HIGH PLAINS LATE FRIDAY EVENING AND SATURDAY MORNING. WEAK CONVERGENCE IN THE THETA-E GRADIENT WILL LIFT MOIST AIR INTO AN ELEVATED UNSTABLE LAYER...RESULTING IN ISOLATED CONVECTION OVERNIGHT FRIDAY AND EARLY SATURDAY. THE MEDIUM RANGE MODELS CONTINUE TO PEG NORTH CENTRAL NEBRASKA AND THE CENTRAL SANDHILLS AS THE MOST LIKELY LOCATION FOR ISOLATED STORMS...HOWEVER A DRY LAYER ROOTED IN THE LOWER LEVELS WILL LIMIT THE COVERAGE AND INTENSITY OF ANY POTENTIAL STORMS. WILL CONTINUE A SLIGHT CHANCE MENTION OF THUNDER SATURDAY INTO EARLY SUNDAY AS RETURN FLOW CONTINUES TO ADVECT MOIST AIR NORTH ATOP THE CENTRAL PLAINS. TIMING OF THE ARRIVAL OF STORMS/MOISTURE DIFFER...BUT THE MODELS ALL GENERALLY AGREE IN SUGGESTING WEAK FORCING FROM A PASSING DISTURBANCE WITH AN INCREASING LLJ. WILL GENERALLY FAVOR THE EASTERN THIRD OF THE CWA FOR SLIGHT CHANCE POPS WHERE THE RICHER MOISTURE IS ANTICIPATED. MARGINAL INSTABILITY WILL BE IN PLACE...BUT 40KTS OF BULK SHEAR WOULD WORK WITH UP TO 1000J OF MUCAPE TO PROMOTE THE POSSIBILITY OF NEAR SEVERE STORMS. A FRONT CLEARS THE THE CWA EARLY ON SUNDAY...TEMPERATURES WILL COOL SLIGHTLY AND RAIN CHANCES WILL BE SOUTH AND EAST OF THE FORECAST AREA. BEYOND MONDAY ATTENTION TURNS TO A CLOSED SOUTHERN PLAINS MID LEVEL LOW WHICH IS SHOWN TO EVENTUALLY BE DRAWN NORTH IN ADVANCE OF THE NEXT SIGNIFICANT WEST COAST TROUGH. THE MODELS ARE STRUGGLING WITH THE HANDLING OF THIS CYCLONE AND THE EVENTUAL INTERACTION WITH THE TROUGH. SO DID NOT MAKE ANY SIGNIFICANT CHANGES TO THE INIT AT THIS TIME DUE TO THE INCONSISTENCIES OF THE LONG RANGE MODELS. BECAUSE OF THIS...WE/RE LEFT WITH CONTINUOUS POPS EACH PERIOD SOMEWHERE WITHIN THE CWA BEGINNING TUESDAY MORNING. AT THIS TIME THE GREATEST CHANCES OF WIDESPREAD POPS APPEAR TO OCCUR WEDNESDAY NIGHT INTO THURSDAY AS THE MAIN UPPER TROUGH AND ASSOCIATED COLD FRONT SPREAD EAST ONTO THE PLAINS. TEMPERATURES THROUGH THE EXTENDED LARGELY LOOK TO RETURN NEAR OR ABOVE AVERAGE...HOWEVER A POTENTIAL COLD FRONT LATE NEXT WEEK COULD COOL TEMPERATURES BACK BELOW NORMAL. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1259 PM CDT THU APR 9 2015 SNOW CONTINUES TO PUSH EAST OF THE AREA. SNOW HAS ALREADY ENDED AT KVTN HOWEVER A LINGERING BRIEF LOW MVFR CIG IS POSSIBLE. ANOTHER HOUR OR TWO WITH LIGHT SNOW AT KLBF. ALL SNOW SHOULD EXIT N CENTRAL BY LATE AFTERNOON. MEANWHILE CLEARING SKIES WILL SPREAD IN FROM THE WEST. THIS AFTERNOON NW WINDS WILL BE ON THE INCREASE...GUSTING TO 20 TO 30 KTS...HOWEVER DECOUPLING WILL RESULT IN LIGHT WINDS OVERNIGHT. LIGHT WINDS CONTINUE THROUGH 18Z TOMORROW. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...JACOBS AVIATION...MASEK
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
619 AM CDT THU APR 9 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 343 AM CDT THU APR 9 2015 TODAY AND TONIGHT...THE RAP MODEL AND HRRR SEEM TO HAVE A GOOD HANDLE ON THE RAIN SNOW LINE ADVANCING SOUTH AND EAST THROUGH THE PANHANDLE THIS MORNING. SNOW IS UNDERWAY FROM HEMINGFORD TO SCOTTSBLUFF TO HARRISBURG IN BANNER COUNTY. THE RAP AND SFC OBSERVATIONS SHOW THE RAIN TO SNOW CHANGING OVER WHEN H700MB TEMPERATURES REACH -6C OR COLDER AND THE MODEL FORECAST IS FOR -8C ACROSS ALL OF THE FCST AREA. THIS SUGGESTS A RAIN SNOW MIX WILL DEVELOP ACROSS MOST OF THE FCST AREA AND ALL SNOW ALONG AND NORTH OF NEBRASKA HIGHWAY 2. THE RAP ALSO SHOWS AROUND 0.25 INCHES OF RAINFALL THIS MORNING WHICH COULD PRODUCE AROUND 2 INCHES OF SNOW IN THE SANDHILLS. THE SATELLITE WATER VAPOR AND RAP40 ANALYZE A DEFORMATION ZONE UNDERWAY ACROSS THE PANHANDLE THIS MORNING AND THIS FEATURE SHOULD MOVE DUE EAST AND BE LOCATED EAST OF HIGHWAY 83 BY 18Z LENDING CLARITY TO THE PRECIPITATION FORECAST. THE RAIN AND SNOW SHOULD EXIT THE FCST AREA AROUND 21Z WITH CLEARING SKIES MOVING IN FROM THE NORTHWEST AT THE SAME TIME. THE RAP SUGGESTS HIGHS IN THE LOWER 40S WHICH WAS MARKED UP TO UPPER 40S TO NEAR 50 IN SOME AREAS. THE WRN SANDHILLS WILL LIKELY EXPERIENCE HIGHS IN THE LOWER 40S AS PROGGED BY THE RAP. H850MB WINDS INCREASE TO 40 KTS FOR NORTH WINDS 25 TO 30 MPH. HIGH PRESSURE WILL MOVE OVERHEAD TONIGHT WITH GENERALLY CLEAR SKIES FOR LOWS IN THE UPPER 20S TO LOWER 30S. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 343 AM CDT THU APR 9 2015 RETURN FLOW AIDED BY THE DEVELOPMENT OF A LEE SIDE TROUGH ON FRIDAY WILL ADVECT MOISTURE FROM THE GULF COAST NORTHWARD ONTO THE HIGH PLAINS. AS THE MOISTURE INCREASES...THERE ARE INDICATIONS OF A WEAK ATMOSPHERIC DISTURBANCE PASSING THROUGH THE HIGH PLAINS LATE FRIDAY EVENING AND SATURDAY MORNING. WEAK CONVERGENCE IN THE THETA-E GRADIENT WILL LIFT MOIST AIR INTO AN ELEVATED UNSTABLE LAYER...RESULTING IN ISOLATED CONVECTION OVERNIGHT FRIDAY AND EARLY SATURDAY. THE MEDIUM RANGE MODELS CONTINUE TO PEG NORTH CENTRAL NEBRASKA AND THE CENTRAL SANDHILLS AS THE MOST LIKELY LOCATION FOR ISOLATED STORMS...HOWEVER A DRY LAYER ROOTED IN THE LOWER LEVELS WILL LIMIT THE COVERAGE AND INTENSITY OF ANY POTENTIAL STORMS. WILL CONTINUE A SLIGHT CHANCE MENTION OF THUNDER SATURDAY INTO EARLY SUNDAY AS RETURN FLOW CONTINUES TO ADVECT MOIST AIR NORTH ATOP THE CENTRAL PLAINS. TIMING OF THE ARRIVAL OF STORMS/MOISTURE DIFFER...BUT THE MODELS ALL GENERALLY AGREE IN SUGGESTING WEAK FORCING FROM A PASSING DISTURBANCE WITH AN INCREASING LLJ. WILL GENERALLY FAVOR THE EASTERN THIRD OF THE CWA FOR SLIGHT CHANCE POPS WHERE THE RICHER MOISTURE IS ANTICIPATED. MARGINAL INSTABILITY WILL BE IN PLACE...BUT 40KTS OF BULK SHEAR WOULD WORK WITH UP TO 1000J OF MUCAPE TO PROMOTE THE POSSIBILITY OF NEAR SEVERE STORMS. A FRONT CLEARS THE THE CWA EARLY ON SUNDAY...TEMPERATURES WILL COOL SLIGHTLY AND RAIN CHANCES WILL BE SOUTH AND EAST OF THE FORECAST AREA. BEYOND MONDAY ATTENTION TURNS TO A CLOSED SOUTHERN PLAINS MID LEVEL LOW WHICH IS SHOWN TO EVENTUALLY BE DRAWN NORTH IN ADVANCE OF THE NEXT SIGNIFICANT WEST COAST TROUGH. THE MODELS ARE STRUGGLING WITH THE HANDLING OF THIS CYCLONE AND THE EVENTUAL INTERACTION WITH THE TROUGH. SO DID NOT MAKE ANY SIGNIFICANT CHANGES TO THE INIT AT THIS TIME DUE TO THE INCONSISTENCIES OF THE LONG RANGE MODELS. BECAUSE OF THIS...WE/RE LEFT WITH CONTINUOUS POPS EACH PERIOD SOMEWHERE WITHIN THE CWA BEGINNING TUESDAY MORNING. AT THIS TIME THE GREATEST CHANCES OF WIDESPREAD POPS APPEAR TO OCCUR WEDNESDAY NIGHT INTO THURSDAY AS THE MAIN UPPER TROUGH AND ASSOCIATED COLD FRONT SPREAD EAST ONTO THE PLAINS. TEMPERATURES THROUGH THE EXTENDED LARGELY LOOK TO RETURN NEAR OR ABOVE AVERAGE...HOWEVER A POTENTIAL COLD FRONT LATE NEXT WEEK COULD COOL TEMPERATURES BACK BELOW NORMAL. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 618 AM CDT THU APR 9 2015 IFR CIGS AND VSBY IN RASN COVERING WRN AND NCNTL NEB ARE EXPECTED TO IMPROVE MARKEDLY AS EARLY AS 18Z WITH VFR/MVFR CIGS SPREADING EAST THROUGH THE FCST AREA THIS AFTN. VFR IS EXPECTED ALL AREAS FROM 00Z ONWARD THIS EVENING. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...JACOBS AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
343 AM CDT THU APR 9 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 343 AM CDT THU APR 9 2015 TODAY AND TONIGHT...THE RAP MODEL AND HRRR SEEM TO HAVE A GOOD HANDLE ON THE RAIN SNOW LINE ADVANCING SOUTH AND EAST THROUGH THE PANHANDLE THIS MORNING. SNOW IS UNDERWAY FROM HEMINGFORD TO SCOTTSBLUFF TO HARRISBURG IN BANNER COUNTY. THE RAP AND SFC OBSERVATIONS SHOW THE RAIN TO SNOW CHANGING OVER WHEN H700MB TEMPERATURES REACH -6C OR COLDER AND THE MODEL FORECAST IS FOR -8C ACROSS ALL OF THE FCST AREA. THIS SUGGESTS A RAIN SNOW MIX WILL DEVELOP ACROSS MOST OF THE FCST AREA AND ALL SNOW ALONG AND NORTH OF NEBRASKA HIGHWAY 2. THE RAP ALSO SHOWS AROUND 0.25 INCHES OF RAINFALL THIS MORNING WHICH COULD PRODUCE AROUND 2 INCHES OF SNOW IN THE SANDHILLS. THE SATELLITE WATER VAPOR AND RAP40 ANALYZE A DEFORMATION ZONE UNDERWAY ACROSS THE PANHANDLE THIS MORNING AND THIS FEATURE SHOULD MOVE DUE EAST AND BE LOCATED EAST OF HIGHWAY 83 BY 18Z LENDING CLARITY TO THE PRECIPITATION FORECAST. THE RAIN AND SNOW SHOULD EXIT THE FCST AREA AROUND 21Z WITH CLEARING SKIES MOVING IN FROM THE NORTHWEST AT THE SAME TIME. THE RAP SUGGESTS HIGHS IN THE LOWER 40S WHICH WAS MARKED UP TO UPPER 40S TO NEAR 50 IN SOME AREAS. THE WRN SANDHILLS WILL LIKELY EXPERIENCE HIGHS IN THE LOWER 40S AS PROGGED BY THE RAP. H850MB WINDS INCREASE TO 40 KTS FOR NORTH WINDS 25 TO 30 MPH. HIGH PRESSURE WILL MOVE OVERHEAD TONIGHT WITH GENERALLY CLEAR SKIES FOR LOWS IN THE UPPER 20S TO LOWER 30S. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 343 AM CDT THU APR 9 2015 RETURN FLOW AIDED BY THE DEVELOPMENT OF A LEE SIDE TROUGH ON FRIDAY WILL ADVECT MOISTURE FROM THE GULF COAST NORTHWARD ONTO THE HIGH PLAINS. AS THE MOISTURE INCREASES...THERE ARE INDICATIONS OF A WEAK ATMOSPHERIC DISTURBANCE PASSING THROUGH THE HIGH PLAINS LATE FRIDAY EVENING AND SATURDAY MORNING. WEAK CONVERGENCE IN THE THETA-E GRADIENT WILL LIFT MOIST AIR INTO AN ELEVATED UNSTABLE LAYER...RESULTING IN ISOLATED CONVECTION OVERNIGHT FRIDAY AND EARLY SATURDAY. THE MEDIUM RANGE MODELS CONTINUE TO PEG NORTH CENTRAL NEBRASKA AND THE CENTRAL SANDHILLS AS THE MOST LIKELY LOCATION FOR ISOLATED STORMS...HOWEVER A DRY LAYER ROOTED IN THE LOWER LEVELS WILL LIMIT THE COVERAGE AND INTENSITY OF ANY POTENTIAL STORMS. WILL CONTINUE A SLIGHT CHANCE MENTION OF THUNDER SATURDAY INTO EARLY SUNDAY AS RETURN FLOW CONTINUES TO ADVECT MOIST AIR NORTH ATOP THE CENTRAL PLAINS. TIMING OF THE ARRIVAL OF STORMS/MOISTURE DIFFER...BUT THE MODELS ALL GENERALLY AGREE IN SUGGESTING WEAK FORCING FROM A PASSING DISTURBANCE WITH AN INCREASING LLJ. WILL GENERALLY FAVOR THE EASTERN THIRD OF THE CWA FOR SLIGHT CHANCE POPS WHERE THE RICHER MOISTURE IS ANTICIPATED. MARGINAL INSTABILITY WILL BE IN PLACE...BUT 40KTS OF BULK SHEAR WOULD WORK WITH UP TO 1000J OF MUCAPE TO PROMOTE THE POSSIBILITY OF NEAR SEVERE STORMS. A FRONT CLEARS THE THE CWA EARLY ON SUNDAY...TEMPERATURES WILL COOL SLIGHTLY AND RAIN CHANCES WILL BE SOUTH AND EAST OF THE FORECAST AREA. BEYOND MONDAY ATTENTION TURNS TO A CLOSED SOUTHERN PLAINS MID LEVEL LOW WHICH IS SHOWN TO EVENTUALLY BE DRAWN NORTH IN ADVANCE OF THE NEXT SIGNIFICANT WEST COAST TROUGH. THE MODELS ARE STRUGGLING WITH THE HANDLING OF THIS CYCLONE AND THE EVENTUAL INTERACTION WITH THE TROUGH. SO DID NOT MAKE ANY SIGNIFICANT CHANGES TO THE INIT AT THIS TIME DUE TO THE INCONSISTENCIES OF THE LONG RANGE MODELS. BECAUSE OF THIS...WE/RE LEFT WITH CONTINUOUS POPS EACH PERIOD SOMEWHERE WITHIN THE CWA BEGINNING TUESDAY MORNING. AT THIS TIME THE GREATEST CHANCES OF WIDESPREAD POPS APPEAR TO OCCUR WEDNESDAY NIGHT INTO THURSDAY AS THE MAIN UPPER TROUGH AND ASSOCIATED COLD FRONT SPREAD EAST ONTO THE PLAINS. TEMPERATURES THROUGH THE EXTENDED LARGELY LOOK TO RETURN NEAR OR ABOVE AVERAGE...HOWEVER A POTENTIAL COLD FRONT LATE NEXT WEEK COULD COOL TEMPERATURES BACK BELOW NORMAL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1153 PM CDT WED APR 8 2015 IFR CEILINGS ARE FORECAST UNTIL 16Z AT KLBF AND KVTN. A STORM SYSTEM WILL TRACK EAST ACROSS WESTERN NEBRASKA OVERNIGHT AND THURSDAY BRINGING RA TO KLBF. COLDER AIR MOVING IN TO BRING A MIX OF RASN OR A POSSIBLE CHANGEOVER TO SN TO KVTN FROM 10Z-15Z. WINDS 34015G25KT WILL OCCUR AFTER 12Z WITH CEILINGS IMPROVING TO MVFR BY 16Z AND THEN VFR BY 20Z FOR BOTH TERMINALS. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...JACOBS AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1133 PM CDT WED APR 8 2015 .SHORT TERM...(TONIGHT THROUGH SATURDAY) ISSUED AT 315 PM CDT WED APR 8 2015 PRIMARY FORECAST CONCERNS ARE IN REGARDS TO CONVECTION TONIGHT AND ALSO SHOWERS ON THURSDAY. SOME STORMS DID OCCUR WITH SMALL HAIL FROM NORTH OF LINCOLN TOWARD OMAHA EARLY THIS MORNING. STORMS REALLY DID NOT GET GOING STRONG TO SEVERE UNTIL THEY WERE IN THE DMX FORECAST AREA. 500 MB CHART FROM 12Z SHOWED MAIN TROUGH STILL WELL OFF TO THE WEST. HEIGHT FALLS UP TO AROUND 100 METERS WERE BACK OVER UTAH AT 12Z...BUT AS OF EARLY AFTERNOON HAD PUSHED INTO PARTS OF WYOMING AND COLORADO. GENERALLY EXPECT PCPN TO INCREASE IN COVERAGE TONIGHT...WITH HEAVIEST PCPN AFTER ABOUT 11 PM. RECENT HRRR MODEL RUNS SUGGEST SOME STRONG STORMS MAY FORM EARLY EVENING NEAR THE MISSOURI BORDER AREA. OTHERWISE...MODELS TRENDS SHOWED LOW LEVEL JET SHOULD INCREASE WITH UP TO 50 KNOTS AT 850 MB BY LATE EVENING. THIS SHOULD HELP BRING AN INCREASE IN TSTMS OVER EASTERN NEBRASKA BY MIDNIGHT OR SO. 12Z NAM FORECAST SOUNDINGS SHOWED UP TO AROUND 2000 J/KG OR MORE OF ELEVATED CAPE AVAILABLE WITH 0-6 KM BULK SHEAR ADEQUATE FOR ROTATING ELEVATED STORMS. THESE SHOULD BRING A RISK OF HAIL MAINLY FROM 05Z TO 10Z...AND A FEW STORMS MAY BE SEVERE. THERE COULD ALSO BE SOME LOCALLY HEAVY RAIN. SHORTWAVE TO THE WEST WILL MOVE THROUGH THE AREA THURSDAY...WITH HEAVIEST RAIN AMOUNTS ACROSS THE NORTHERN PARTS OF THE FORECAST AREA NEAR DEFORMATION ZONE. WINDS WILL ALSO INCREASE AS SURFACE LOW TRACKS EAST/NORTHEAST ACROSS IOWA DURING THE DAY AND THE PRESSURE GRADIENT IN OUR AREA INCREASES. SPEEDS OF 20 TO 30 MPH WITH GUSTS AROUND 40 MPH OR MORE SHOULD BE COMMON. DROPPED FORECAST HIGHS JUST A BIT...WITH MOSTLY 50S EXPECTED THURSDAY. PCPN WILL END BY THURSDAY EVENING WITH CLOUDS DECREASING THURSDAY NIGHT. HIGH PRESSURE AT THE SURFACE BUILDS IN FOR THURSDAY NIGHT AND FRIDAY. SOUTHERLY FLOW IS FORECAST TO INCREASE FRIDAY NIGHT... MOSTLY TO OUR WEST...SO NO PCPN IS EXPECTED LOCALLY FRIDAY NIGHT. WILL INCLUDE A SLIGHT CHANCE TSTMS FOR MAINLY OUR WESTERN ZONES SATURDAY. .LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 315 PM CDT WED APR 8 2015 WILL NEED TO INCLUDE A CHANCE OF SHOWERS AND TSTMS FOR MUCH OF THE EXTENDED FORECAST PERIOD. HIGHEST CHANCES AND HEAVIEST AMOUNTS LIKELY AS SHORTWAVE MOVES OUT ACROSS THE CENTRAL PLAINS MONDAY NIGHT INTO TUESDAY. HIGHS SHOULD BE MOSTLY IN THE 70S THIS PERIOD...BUT SOME UPPER 60S POSSIBLE ON MONDAY. LOWS GENERALLY 40S TO LOWER 50S. && .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1129 PM CDT WED APR 8 2015 IFR TO LIFR CONDITIONS WILL CONTINUE AS A VERY MOIST LOW LEVEL LAYER REMAINS OVER THE REGION. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE TO SPREAD OVER THE TAF SITES THROUGH THE MORNING HOURS. DID NOT INCLUDE A MENTION OF THUNDER...BUT WILL CONTINUE TO MONITOR TRENDS AND AMEND AS NECESSARY. WINDS WILL TURN TO THE NORTHWEST AS A COLD FRONT DROPS ACROSS THE AREA ON THURSDAY. GUSTS UP TO 35KTS ARE POSSIBLE LATE THURSDAY MORNING INTO THURSDAY AFTERNOON. SKIES AND VISIBILITIES MAY BEGIN TO SCATTER OUT QUICKLY AROUND SUNSET...PERHAPS BECOMING CLEAR BY THE END OF THE TAF CYCLE. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...MILLER LONG TERM...MILLER AVIATION...KERN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1038 PM EDT FRI APR 10 2015 .SYNOPSIS... A COLD FRONT WITH SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE AREA OVERNIGHT...WITH SHOWERS LINGERING INTO EARLY SATURDAY MORNING. DRY HIGH PRESSURE WILL FOLLOW AND BUILD INTO THE CAROLINAS THROUGH THE EARLY NEXT WEEK. A SECOND COLD FRONT WILL MOVE ACROSS THE REGION TUESDAY WITH ANOTHER HIGH PRESSURE FOLLOWING INTO THE MIDWEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... AS OF 1030 PM FRIDAY...SEVERE POTENTIAL CONTINUES TO DIMINISH THIS EVENING AS CONVECTION MOVES INTO A RELATIVELY STABLE AND DRY ATMOSPHERE. HAVE FURTHER RATCHETED BACK ON TIMING...COVERAGE AND STRENGTH OF OVERNIGHT ACTIVITY. ALTHOUGH THE ODD THUNDERSTORM CANNOT BE RULED OUT...WE ARE NOW EXPECTING MORE IN THE WAY OF LIGHT RAIN AND SHOWER ACTIVITY IN THE EARLY MORNING HOURS. PREVIOUS DISCUSSIONS FOLLOW: BASED ON LATEST TRENDS HAVE FURTHER DELAYED TIMING OF SHOWER/THUNDERSTORM PROGRESSION ACROSS THE FORECAST AREA. ISOLATED LIGHT ACTIVITY IS ONLY NOW MAKING ITS WAY INTO OUR FAR NORTHWESTERN COUNTIES AND DO NOT THINK WE WILL SEE ANYTHING MAKE IT TO THE COAST BEFORE ABOUT MIDNIGHT. DEWPOINTS ARE ON THE LOW SIDE AND MUCH OF THE CWA IS NOW WITHIN THE MORE STABLE SECTOR OF THE SEA BREEZE CIRCULATION SO CONFIDENCE IN THE SEVERE THREAT IS LOWER THAN EARLIER THIS AFTERNOON.LATEST HRRR KEEPS BULK OF ACTIVITY WELL INLAND. HAVE MADE APPROPRIATE CHANGES TO THE FORECAST WITH ALL THIS IN MIND. PREVIOUS DISCUSSION FOLLOWS: BETWEEN THE STABILIZING EFFECTS OF THE SEA BREEZE AN THE SLOWER THAN EXPECTED ARRIVAL OF THE COLD FRONT FORCED CONVECTION THE SEVERE WEATHER THREAT HAS DIMINISHED. SAT IMAGERY SHOWS MINIMAL DEVELOPMENT IN CU FIELDS DESPITE THE WARM AND HUMID AFTERNOON. SIMILARLY THE ISOLATED ACTIVITY TO OUR WEST MAY HAVE TROUBLE SURVIVING INTO OUR REGION DUE TO THE DRYNESS INDICATED IN THE LCL- LFC LAYER. BUT JUST IN CASE HAVE BEEN CARRYING LOW POPS OVER WESTERN ZONES BEGINNING AROUND 21Z. THIS IS A BIT QUICKER THAN THE WRF BUT SLOWER THAN THE NOW OUTLYING GFS. THE MOST UNCERTAINTY HAS COME THIS AFTERNOON FROM THE HIGH RES MODELS SUCH AS THE RUC AND THE HRRR. SUCH GUIDANCE HAS CONSISTENTLY SHOWN ANY AND ALL PREFRONTAL PRECIPITATION DETERIORATE COMPLETE. TAKE THE HRRR FOR EXAMPLE...NOT A DROP OF RAIN UNTIL SOME FAIRLY BENIGN LOOKING SHALLOW CONVECTION ENTERS OUR AREA...AT 04Z! CURRENT FORECAST IS NOT SO BOLDLY DRY BUT JUST RECENTLY NOTICED THAT THE PREFRONTAL TROUGH DEPICTED ON THE WRF IS MUCH TOO STRONG COMPARED TO REALITY. SO THE TREND STARTED THIS MORNING OF SLOWING DOWN TIMING MAY VERY WELL CONTINUE THIS EVENING WITH JUST A SLOW RAMPING UP OF POPS FROM NW TO SE...BUT THE BULK OF THE RAIN COMING LATE OVERNIGHT AND GENERALLY SHALLOW CONVECTION WITH JUST ISOLATED THUNDER. THE REMAINING SEVERE THREAT IS OVER FAR INLAND ZONES WITH ANY PREFRONTAL ACTIVITY THAT MANAGES TO DEVELOP OR ADVECT IN FROM THE WEST...REPRESENTING A LOW END DAMAGING WIND THREAT. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... AS OF 330 PM FRIDAY...THE COLD FRONT IS EXPECTED TO BE JUST OFF THE COAST BY 12 UTC WITH LINGERING EARLY MORNING SHOWERS. AFTER THE PRECIPITATION CLEARS SATURDAY MORNING...DRIER HIGH PRESSURE WILL FILTER INTO THE AREA THROUGH THE REMAINDER OF THE OF THE WEEKEND. HIGH TEMPERATURES BOTH DAYS WILL BE IN THE 74 TO 78 DEGREE RANGE WITH RELATIVE HUMIDITY VALUES DROPPING INTO THE LOWER TO MIDDLE 30% RANGE LATE IN THE DAY. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 330 PM FRIDAY...WETTISH EXTENDED PERIOD AS UPSTREAM UPPER TROUGHING ALLOWS GULF MOISTURE TAPS TO EJECT NE INTO THE EASTERN CAROLINAS TUESDAY THROUGH FRIDAY. FIRST IMPULSE GUIDED FROM THE MISSISSIPPI DELTA STREAMS NE IN AN ELEVATED PRECIPITABLE WATER PLUME AS HIGH PRESSURE ANCHORS FROM THE NORTH TO INSTIGATE AN EARLY SPRING OVER-RUNNING WEDGE PATTERN INTO WEDNESDAY. HIGHLY AMPLIFIED UPPER TROUGH EDGES EAST OVER THE VALLEY OVERSPREADING GULF VAPOR CONTENT THURSDAY AS THE WEDGE ERODES IN WET AND ISENTROPIC OMEGA. EXTENDED PERIOD CULMINATES INTO A RAINY FRIDAY AS THE AMPED UPPER TROUGH FORCES A COLD FRONT ACROSS FORECAST AREA DAY 7. WPC QPF DEPICTIONS FOR DAYS 4-5 AND 6-7 YIELD BASIN AVERAGE COLLECTIVE RAIN TOTALS OF 1-2.5 INCHES. PLENTIFUL CLOUDS IN BALMY SW FLOW ALOFT AND WEDGE PATTERN THIS PERIOD RESULTS IN MAXIMUMS PRIMARILY 70S...MINIMUMS UPPER 50S TO LOWER 60S. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... AS OF 00Z...SO FAR...IT LOOKS LIKE A BIG DISAPPOINTMENT WITH REGARD TO CONVECTION. THE CONVECTION IS FAIRLY STRONG IN COLUMBIA`S CWA...BUT THAT WAS WHERE THE MAX CAPE RESIDED. WE STILL HAVE SOME WARM AIR ALOFT THAT IS TAMPERING THINGS. NEVERTHELESS WILL KEEP SOME CONVECTION IN THE AREA TONIGHT...BUT WILL SLOW THINGS DOWN AND WILL TAKE OUT THE HEAVY GUSTS. LBT AND FLO STAND THE BEST CHANCE FOR THUNDER...BUT THINK IT WILL BE FLEETING. SATURDAY MORNING...SOME IFR CEILINGS ARE POSSIBLE AS THE FRONT DROPS IN...WITH A CONTINUED CHANCE FOR SHOWERS. THE WINDS SHIFT TO THE NORTHEAST...POST FRONTAL BY MID TO LATE MORNING...WITH IMPROVING CONDITIONS IN THE AFTERNOON. EXTENDED OUTLOOK...EXPECT VFR WITH INCREASING RAIN CHANCES INTO NEXT WEEK. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 PM...NO CHANGES TO THE FORECAST WITH THE LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS: SOUTHWESTERLY FLOW EXPECTED THROUGH THE PERIOD IN A PRE-FRONTAL FLOW REGIME. THE APPROACH OF THE BOUNDARY LATE TONIGHT WILL TIGHTEN THE GRADIENT SOMEWHAT LEADING TO A SMALL INCREASE IN WINDS AND SEAS. WHILE THIS MAY INTRODUCE 5 FT SEAS ALONG THE OUTER PORTIONS OF SOME OF THE FORECAST ZONES THE LARGE COAST- PARALLEL COMPONENT SHOULD SPONSOR ENOUGH OF A GRADIENT IN NEARSHORE VS OFFSHORE WAVES TO PRECLUDE A SCEC. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 330 PM FRIDAY...WINDS OVER THE WATERS WILL BE SHIFTING TO THE NORTHWEST WITH THE FRONTAL PASSAGE AND THEN NORTHEAST TO EAST LATE SATURDAY INTO SUNDAY. WINDS SPEEDS WILL BE 15 TO 20 KNOTS EARLY IN THE MORNING BEFORE DROPPING DOWN TO 15 KNOTS BY THE EVENING. ON SUNDAY THE PRESSURE GRADIENT TIGHTENS AND WINDS ARE EXPECT TO PEAK AGAIN AT 15 TO 20 KNOTS SUNDAY MORNING BEFORE DROPPING BACK TO 10 TO 15 KNOTS OVERNIGHT SUNDAY. SEAS WILL BE RUNNING AROUND 3 TO 5 FEET SATURDAY MORNING WITH A FALL TO 2 TO 4 FEET SATURDAY AFTERNOON WITH THE OFFSHORE FLOW. WITH THE NORTHEAST FLOW INCREASING THE SEAS WILL INCREASE BACK TO 3 TO 4 FEET ON SUNDAY. LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 330 PM FRIDAY...A BUMPY MARINE ENVIRONMENT MON-WED AS A MODERATE ONSHORE WIND FLOW KEEPS SEAS SLIGHTLY ELEVATED...AND OVERALL 3-5 FEET. UNSETTLED CONDITIONS MAY PLAGUE THE WATERS WITH RAIN AND OCCASIONAL REDUCED VISIBILITY AND ISOLATED TSTMS AS GULF MOISTURE AND DISTURBANCES SPREAD NE OVER THE 0-20 NM WATERS. SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE WEDNESDAY FOR 6 FOOT SEAS OFFSHORE...AS HIGH PRESSURE BUILDS SOUTH AND INTERACTS WITH AN OFFSHORE COASTAL TROUGH. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...DRH NEAR TERM...REK/MBB SHORT TERM...DRH LONG TERM...MJC AVIATION...DL MARINE...MJC/REK/DRH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
738 PM EDT FRI APR 10 2015 .SYNOPSIS... A COLD FRONT WITH SHOWERS AND THUNDERSTORMS WILL APPROACH THE AREA OVERNIGHT WITH SHOWERS LINGERING INTO EARLY SATURDAY MORNING. DRY HIGH PRESSURE WILL FOLLOW AND BUILD INTO THE CAROLINAS THROUGH THE EARLY NEXT WEEK. A SECOND COLD FRONT WILL MOVE ACROSS THE REGION TUESDAY WITH ANOTHER HIGH PRESSURE FOLLOWING INTO THE MIDWEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... AS OF 730 PM FRIDAY...BASED ON LATEST TRENDS HAVE FURTHER DELAYED TIMING OF SHOWER/THUNDERSTORM PROGRESSION ACROSS THE FORECAST AREA. ISOLATED LIGHT ACTIVITY IS ONLY NOW MAKING ITS WAY INTO OUR FAR NORTHWESTERN COUNTIES AND DO NOT THINK WE WILL SEE ANYTHING MAKE IT TO THE COAST BEFORE ABOUT MIDNIGHT. DEWPOINTS ARE ON THE LOW SIDE AND MUCH OF THE CWA IS NOW WITHIN THE MORE STABLE SECTOR OF THE SEA BREEZE CIRCULATION SO CONFIDENCE IN THE SEVERE THREAT IS LOWER THAN EARLIER THIS AFTERNOON.LATEST HRRR KEEPS BULK OF ACTIVITY WELL INLAND. HAVE MADE APPROPRIATE CHANGES TO THE FORECAST WITH ALL THIS IN MIND. PREVIOUS DISCUSSION FOLLOWS: BETWEEN THE STABILIZING EFFECTS OF THE SEA BREEZE AN THE SLOWER THAN EXPECTED ARRIVAL OF THE COLD FRONT FORCED CONVECTION THE SEVERE WEATHER THREAT HAS DIMINISHED. SAT IMAGERY SHOWS MINIMAL DEVELOPMENT IN CU FIELDS DESPITE THE WARM AND HUMID AFTERNOON. SIMILARLY THE ISOLATED ACTIVITY TO OUR WEST MAY HAVE TROUBLE SURVIVING INTO OUR REGION DUE TO THE DRYNESS INDICATED IN THE LCL- LFC LAYER. BUT JUST IN CASE HAVE BEEN CARRYING LOW POPS OVER WESTERN ZONES BEGINNING AROUND 21Z. THIS IS A BIT QUICKER THAN THE WRF BUT SLOWER THAN THE NOW OUTLYING GFS. THE MOST UNCERTAINTY HAS COME THIS AFTERNOON FROM THE HIGH RES MODELS SUCH AS THE RUC AND THE HRRR. SUCH GUIDANCE HAS CONSISTENTLY SHOWN ANY AND ALL PREFRONTAL PRECIPITATION DETERIORATE COMPLETE. TAKE THE HRRR FOR EXAMPLE...NOT A DROP OF RAIN UNTIL SOME FAIRLY BENIGN LOOKING SHALLOW CONVECTION ENTERS OUR AREA...AT 04Z! CURRENT FORECAST IS NOT SO BOLDLY DRY BUT JUST RECENTLY NOTICED THAT THE PREFRONTAL TROUGH DEPICTED ON THE WRF IS MUCH TOO STRONG COMPARED TO REALITY. SO THE TREND STARTED THIS MORNING OF SLOWING DOWN TIMING MAY VERY WELL CONTINUE THIS EVENING WITH JUST A SLOW RAMPING UP OF POPS FROM NW TO SE...BUT THE BULK OF THE RAIN COMING LATE OVERNIGHT AND GENERALLY SHALLOW CONVECTION WITH JUST ISOLATED THUNDER. THE REMAINING SEVERE THREAT IS OVER FAR INLAND ZONES WITH ANY PREFRONTAL ACTIVITY THAT MANAGES TO DEVELOP OR ADVECT IN FROM THE WEST...REPRESENTING A LOW END DAMAGING WIND THREAT. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... AS OF 330 PM FRIDAY...THE COLD FRONT IS EXPECTED TO BE JUST OFF THE COAST BY 12 UTC WITH LINGERING EARLY MORNING SHOWERS. AFTER THE PRECIPITATION CLEARS SATURDAY MORNING...DRIER HIGH PRESSURE WILL FILTER INTO THE AREA THROUGH THE REMAINDER OF THE OF THE WEEKEND. HIGH TEMPERATURES BOTH DAYS WILL BE IN THE 74 TO 78 DEGREE RANGE WITH RELATIVE HUMIDITY VALUES DROPPING INTO THE LOWER TO MIDDLE 30% RANGE LATE IN THE DAY. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 330 PM FRIDAY...WETTISH EXTENDED PERIOD AS UPSTREAM UPPER TROUGHING ALLOWS GULF MOISTURE TAPS TO EJECT NE INTO THE EASTERN CAROLINAS TUESDAY THROUGH FRIDAY. FIRST IMPULSE GUIDED FROM THE MISSISSIPPI DELTA STREAMS NE IN AN ELEVATED PRECIPITABLE WATER PLUME AS HIGH PRESSURE ANCHORS FROM THE NORTH TO INSTIGATE AN EARLY SPRING OVER-RUNNING WEDGE PATTERN INTO WEDNESDAY. HIGHLY AMPLIFIED UPPER TROUGH EDGES EAST OVER THE VALLEY OVERSPREADING GULF VAPOR CONTENT THURSDAY AS THE WEDGE ERODES IN WET AND ISENTROPIC OMEGA. EXTENDED PERIOD CULMINATES INTO A RAINY FRIDAY AS THE AMPED UPPER TROUGH FORCES A COLD FRONT ACROSS FORECAST AREA DAY 7. WPC QPF DEPICTIONS FOR DAYS 4-5 AND 6-7 YIELD BASIN AVERAGE COLLECTIVE RAIN TOTALS OF 1-2.5 INCHES. PLENTIFUL CLOUDS IN BALMY SW FLOW ALOFT AND WEDGE PATTERN THIS PERIOD RESULTS IN MAXIMUMS PRIMARILY 70S...MINIMUMS UPPER 50S TO LOWER 60S. && .AVIATION /23Z FRIDAY THROUGH WEDNESDAY/... AS OF 00Z...SO FAR...IT LOOKS LIKE A BIG DISAPPOINTMENT WITH REGARD TO CONVECTION. THE CONVECTION IS FAIRLY STRONG IN COLUMBIA`S CWA...BUT THAT WAS WHERE THE MAX CAPE RESIDED. WE STILL HAVE SOME WARM AIR ALOFT THAT IS TAMPERING THINGS. NEVERTHELESS WILL KEEP SOME CONVECTION IN THE AREA TONIGHT...BUT WILL SLOW THINGS DOWN AND WILL TAKE OUT THE HEAVY GUSTS. LBT AND FLO STAND THE BEST CHANCE FOR THUNDER...BUT THINK IT WILL BE FLEETING. SATURDAY MORNING...SOME IFR CEILINGS ARE POSSIBLE AS THE FRONT DROPS IN...WITH A CONTINUED CHANCE FOR SHOWERS. THE WINDS SHIFT TO THE NORTHEAST...POST FRONTAL BY MID TO LATE MORNING...WITH IMPROVING CONDITIONS IN THE AFTERNOON. EXTENDED OUTLOOK...EXPECT VFR WITH INCREASING RAIN CHANCES INTO NEXT WEEK. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 730 PM...NO CHANGES TO THE FORECAST WITH THE LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS: SOUTHWESTERLY FLOW EXPECTED THROUGH THE PERIOD IN A PRE-FRONTAL FLOW REGIME. THE APPROACH OF THE BOUNDARY LATE TONIGHT WILL TIGHTEN THE GRADIENT SOMEWHAT LEADING TO A SMALL INCREASE IN WINDS AND SEAS. WHILE THIS MAY INTRODUCE 5 FT SEAS ALONG THE OUTER PORTIONS OF SOME OF THE FORECAST ZONES THE LARGE COAST- PARALLEL COMPONENT SHOULD SPONSOR ENOUGH OF A GRADIENT IN NEARSHORE VS OFFSHORE WAVES TO PRECLUDE A SCEC. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 330 PM FRIDAY...WINDS OVER THE WATERS WILL BE SHIFTING TO THE NORTHWEST WITH THE FRONTAL PASSAGE AND THEN NORTHEAST TO EAST LATE SATURDAY INTO SUNDAY. WINDS SPEEDS WILL BE 15 TO 20 KNOTS EARLY IN THE MORNING BEFORE DROPPING DOWN TO 15 KNOTS BY THE EVENING. ON SUNDAY THE PRESSURE GRADIENT TIGHTENS AND WINDS ARE EXPECT TO PEAK AGAIN AT 15 TO 20 KNOTS SUNDAY MORNING BEFORE DROPPING BACK TO 10 TO 15 KNOTS OVERNIGHT SUNDAY. SEAS WILL BE RUNNING AROUND 3 TO 5 FEET SATURDAY MORNING WITH A FALL TO 2 TO 4 FEET SATURDAY AFTERNOON WITH THE OFFSHORE FLOW. WITH THE NORTHEAST FLOW INCREASING THE SEAS WILL INCREASE BACK TO 3 TO 4 FEET ON SUNDAY. LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 330 PM FRIDAY...A BUMPY MARINE ENVIRONMENT MON-WED AS A MODERATE ONSHORE WIND FLOW KEEPS SEAS SLIGHTLY ELEVATED...AND OVERALL 3-5 FEET. UNSETTLED CONDITIONS MAY PLAGUE THE WATERS WITH RAIN AND OCCASIONAL REDUCED VISIBILITY AND ISOLATED TSTMS AS GULF MOISTURE AND DISTURBANCES SPREAD NE OVER THE 0-20 NM WATERS. SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE WEDNESDAY FOR 6 FOOT SEAS OFFSHORE...AS HIGH PRESSURE BUILDS SOUTH AND INTERACTS WITH AN OFFSHORE COASTAL TROUGH. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...DRH NEAR TERM...REK/MBB SHORT TERM...DRH LONG TERM...MJC AVIATION...DL MARINE...MJC/REK/DRH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
703 PM EDT THU APR 9 2015 .SYNOPSIS... WARM AND HUMID WEATHER WILL PRECEDE A STRONG COLD FRONT...WHICH WILL CROSS THE AREA LATE FRIDAY NIGHT. A FEW THUNDERSTORMS COULD BE STRONG FRIDAY NIGHT...WITH SHOWERS LINGERING INTO SATURDAY MORNING. DRY AND SEASONABLE CONDITIONS WILL MOVE INTO THE AREA THROUGH THE REMAINDER OF THE WEEKEND. A WARMING TREND WILL UNFOLD EARLY NEXT WEEK...WITH A CHANCE OF SHOWERS TUESDAY INTO WEDNESDAY AS GULF MOISTURE MOVES INTO THE REGION. && .NEAR TERM /THROUGH TONIGHT/... AS OF 236 PM THURSDAY...INITIAL ROUND OF SHOWERS AND THUNDERSTORMS HAVE DISSIPATED AS AN AREA OF SUBSIDENCE IN THE WAKE OF A PASSING IMPULSE ALOFT TEMPORARILY TAKES HOLD. DIURNAL CUMULUS HAS DEVELOPED UPSTREAM AND WITH GOOD INSOLATION ACROSS THE PEE DEE AND LUMBERTON AREAS THE AREA OF SUBSIDENCE WILL WEAKEN. OUTFLOW FROM CONVECTION ACROSS COASTAL SOUTHEAST NC HAS DROPPED INTO HORRY COUNTY... AS NOTED BY EARLIER VISIBLE SATELLITE IMAGERY. THE BOUNDARY COUPLED WITH THE SEA BREEZE SHOULD PROVIDE A SPARK FOR SCATTERED SHOWERS AND THUNDERSTORMS ACROSS NORTHEAST SC THIS AFTERNOON. WIDELY SCATTERED STORMS ARE ALSO POSSIBLE IN THE BETTER INSTABILITY EXPECTED ACROSS THE PEE DEE REGION. THE EARLIER RAINFALL WILL HAVE AN IMPACT ON TODAY/S MAX TEMPERATURES IN THE WILMINGTON AND VICINITY LOCATIONS. AS A RESULT...LOWERED FORECAST MAX TEMPS THERE...WHILE RETAINED HIGHS IN THE 80S FOR LBT...FLO...AND INLAND COASTAL SC LOCATIONS. WARM SOUTHWEST FLOW TONIGHT WILL KEEP MIN TEMPERATURES ABOVE NORMAL. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 236 PM THURSDAY...CHIEF HEADLINES ARE A CHANGE OF AIR-MASS INTO SATURDAY FROM WARM TO MUGGY TO DRY AND MILD...AND A SHOT AT STRONG STORMS LATE FRIDAY AS A COLD FRONT MOVES THROUGH. SEVERE THREAT IS NOT SUPPORTED IN DIURNAL TIMING AS IT ARRIVES BEYOND PEAK SURFACE HEATING FRIDAY NIGHT...BUT COOLING ALOFT MAY SUPPORT SOME HAIL. TIME-HEIGHT ANALYSIS IS NOT OVERLY IMPRESSIVE WITH WINDS NO GREATER THAN 35 KNOTS IN THE LOWEST 8KFT...AND H8 25-30 KT BARBS. PEAK PRECIPITABLE WATER VALUES FRIDAY NIGHT AROUND 1.75 INCHES AND SOME JET SUPPORT ALOFT SHOULD OFFER A GOOD SHOT AT RAIN FRIDAY NIGHT INTO SATURDAY MORNING FROM WEST TO EAST...AND CLEARING THE COAST AROUND MIDDAY SATURDAY. UPPER 80 MAXIMUMS FRIDAY INLAND...LOW 80S COASTAL INTERIOR...AND UPPER 60S TO MIDDLE 70S BEACHES...WILL COOL TO 70S SATURDAY TO NEAR 80 WELL INLAND...UPPER 60S TO 70 BEACHES. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 236 PM THURSDAY...EXTENDED PERIOD LOOKS RATHER QUIET AS A MODEST SOUTHWEST FLOW ALOFT PERSISTS THROUGH THE PERIOD. HIGH PRESSURE WILL SETTLE OVER THE AREA SUNDAY AND MONDAY AND WITH PRECIPITABLE WATER VALUES ARE BELOW ONE HALF INCH SUNDAY WITH A SLOW INCREASE MONDAY. HAVE KEPT THESE DAYS DRY FOR THE MOST PART. SIGNIFICANT MOISTURE INCREASE FOR TUESDAY AND WEDNESDAY AS PWS SURGE TO IN EXCESS OF 1.5 INCHES. HOWEVER SYNOPTIC CONDITIONS SHOW LITTLE IN THE WAY OF FORCING AND POPS WILL REMAIN IN THE SLIGHT CHANCE CATEGORY. SIMILAR CONDITIONS FOR WEDNESDAY. FOR THURSDAY...MEDIUM RANGE GUIDANCE IS COMING INTO BETTER AGREEMENT WITH A BACKDOOR FRONT MOVING ACROSS AS A BROAD AREA OF MID LEVEL CONFLUENCE DEVELOPS ACROSS THE MIDWEST AND GREAT LAKES. I MAINTAINED THE POPS FOR THURSDAY AS MOISTURE REMAINS AND THE BOUNDARY IN THE AREA. NO CHANGES TO TEMPERATURE FORECAST FROM THE PREVIOUS FORECAST AS READINGS WILL BE JUST A LITTLE ABOVE NORMAL. && .AVIATION /00Z FRIDAY THROUGH WEDNESDAY/... AS OF 00Z...MOST OF THE CONVECTION HAS DIMINISHED...HOWEVER THERE IS ONE MORE IMPULSE THAT WILL MOVE INTO THE WESTERN CWA IN AN HOUR OR SO. THE HRRR MODEL HAS FAIRLY SPIRITED CONVECTION OVER THE WESTERN CWA FOR THE NEXT SEVERAL HOURS...BUT THINK THIS MAY BE OVERDONE. WILL KEEP ANY MENTION OF THUNDER OUT OF THE TAFS AT LBT AND FLO AT THIS TIME. OVERNIGHT...MID AND HIGH CLOUD CONVECTIVE DEBRIS IS EXPECTED WITH POSSIBLE MVFR FOG. FRIDAY...AN INCREASING SOUTHWEST GRADIENT AHEAD OF A COLD FRONT WILL GIVE US WIND GUSTS APPROACHING 25 KTS BY EARLY AFTERNOON. THERE SHOULD BE A FAIRLY VIGOROUS LINE OF CONVECTION THAT WILL MARCH ACROSS THE CWA FROM LATE AFTERNOON INTO THE EVENING HOURS. POSSIBLE DAMAGING WINDS AND HAIL CAN BE EXPECTED WITH THIS LINE OF STORMS. EXTENDED OUTLOOK...CHANCE OF SHOWERS AND THUNDERSTORMS FRIDAY NIGHT THROUGH MID MORNING SATURDAY. OTHERWISE EXPECT VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 236 PM THURSDAY...CONVECTION HAS RESULTED IN A VARIABLE WIND FIELD ACROSS THE NC COASTAL WATERS EARLY THIS AFTERNOON. THE LARGER SCALE SYNOPTIC FLOW WILL ONCE AGAIN TAKE HOLD LATER THIS AFTERNOON WITH THE RETURN OF SOUTHERLY FLOW. SPEEDS WILL GENERALLY RANGE FROM 10 TO 15 KNOTS DURING THE OVERNIGHT. OUTSIDE ANY CONVECTION...SEAS ARE EXPECTED TO BE IN THE 2-4 FT RANGE THROUGH THE NEAR TERM. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 236 PM THURSDAY...DESPITE A COLD FRONTAL PASSAGE VERY EARLY SATURDAY JUST PRIOR TO...OR AROUND DAYBREAK THAT MAY BRING A FEW STRONG THUNDERSTORMS...NO SMALL CRAFT ADVISORIES ARE PLANNED...AS WINDS AHEAD OF AND BEHIND THE FRONT REMAIN MOSTLY BELOW 20 KT. GUSTS TO 20 KT FRIDAY AFTERNOON SEEMS LIKELY WITH SEA BREEZE ASSISTANCE...BUT SUSTAINED WINDS ARE NOT OVERLY STRONG WITH THIS SYSTEM OUTSIDE OF TSTMS. A FEW MARINE WARNINGS ARE POSSIBLE LATE FRIDAY NIGHT INTO EARLY SATURDAY. SEAS OF 2-3 FEET WILL BUILD TO 3-4 FEET FRIDAY NIGHT...POSSIBLY 5 FT VERY OUTER PORTION. PATCHY SEA FOG POSSIBLE FRIDAY BUT WATERS HAVE WARMED AND CONFIDENCE IS LOW ON ITS FORMATION. LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 236 PM THURSDAY...SURFACE HIGH PRESSURE WILL MOVE FROM THE APPALACHIANS TO WELL OFFSHORE DURING THE PERIOD. WINDS WILL RESPOND BY VEERING FROM NORTHEAST SUNDAY TO SOUTHEAST BY MIDDAY MONDAY. THEY WILL MAINTAIN THIS DIRECTION THROUGH THE REMAINDER OF THE PERIOD. SPEEDS WILL BE ON THE HIGHER END OF A 10-15 KNOT RANGE SUNDAY THEN SETTLE INTO THE ENTIRE RANGE MONDAY AND TUESDAY. SIGNIFICANT SEAS WILL BE 2-4 FEET SUNDAY DROPPING TO 1-3 FEET LATER MONDAY AND TUESDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MJC NEAR TERM...SRP SHORT TERM...MJC LONG TERM...SHK AVIATION...43
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
958 AM EDT THU APR 9 2015 .SYNOPSIS... A STALLED FRONT WILL BE OVER SOUTHERN SECTIONS THIS MORNING AND RETURN NORTH AS A WARM FRONT THIS AFTERNOON AND TONIGHT. A COLD FRONT WILL APPROACH FROM THE WEST LATE FRIDAY AND MOVE OFFSHORE SATURDAY MORNING. HIGH PRESSURE WILL EXTEND OVER THE AREA FROM THE NORTH SATURDAY NIGHT AND SUNDAY. A WARM FRONT WILL LIFT NORTH OF THE AREA TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1000 AM THURSDAY...THE BACK DOOR FRONT IS LOCATED VICINITY OF THE CRYSTAL COAST/SOUTHERN COASTAL PLAIN WILL DRIFT SLOWLY NORTH THIS AFTERNOON AND EVENING. WILL HOLD TO LIKELY POPS THROUGH NOON ACRS SE SECTIONS. NONE OF THE MODELS IS REALLY HANDLING THIS PRECIPITATION WELL BUT IT STILL LOOKS LIKE A LULL IN THE EARLY AFTERNOON HOURS THEN LATE THIS AFTERNOON INTO EARLY EVENING THE HIGH RESOLUTION NSSL WRF MODEL INDICATES STRONG CONVECTION REDEVELOPING WITH HEATING. THIS IS SUPPORTED SOMEWHAT BY THE LARGER SCALE MODELS SO WILL INCREASE POPS AGAIN DURING THIS TIME. SOME STORMS COULD BE ON THE STRONG SIDE LATE AFTN/EVE. WIDESPREAD STRATUS/PATCHY FOG WILL BE SLOW TO DISSIPATE AND WILL LIKELY LINGER FOR MUCH OF THE MORNING. THERE SHOULD BE ENOUGH AFTERNOON HEATING TO REALIZE HIGHS INLAND IN THE LOWER 80S AND LOWER 70S SOUTHERN COAST BEACHES. ONSHORE FLOW ALONG THE OUTER BANKS OFF THE STILL CHILLY SHELF WATERS WILL PRODUCE HIGHS IN THE LOWER 60S NORTHERN SECTIONS AND MID TO UPPER 60S SOUTH. MADE SOME ADJUSTMENTS TO INIT T/TD. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/... AS OF 415 AM THURSDAY...THE WARM FRONT WILL MOVE NORTH OF THE AREA THIS EVENING. BEST CHANCE OF RAIN SHOULD BE IN THE EVENING THEN GUIDANCE INDICATES MID LEVEL DRYING THUS WILL FORECAST DRY CONDITIONS AFTER 06Z. THE PRESSURE GRADIENT TIGHTENS IN THE WARM SECTOR AND THERE SHOULD BE ENOUGH MIXING TO PRECLUDE ANY FOG DEVELOPMENT ALTHOUGH A SHALLOW NEAR SURFACE LAYER IS FORECAST TO BECOME SATURATED AND COULD SUPPORT THE DEVELOPMENT OF LOW CLOUDS. THE SOUTHERLY FLOW WILL LEAD TO VERY MILD LOW TEMPERATURES IN THE 60S. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... AS OF 400 AM THURSDAY...ONLY SIGNIFICANT CHANGE DURING PERIOD WAS TO LIMIT POPS ERN SECTIONS TO EARLY SAT MORNING...INDICATING DRY FCST OVER LAND AREAS AFTER 15Z. LATEST MODELS IN GOOD AGREEMENT WITH PREVIOUS FCST REST OF PERIOD. MAIN FEATURE DURING PERIOD WILL BE STRONG COLD FRONT THAT WILL MOVE INTO AREA FRI NIGHT AND OFFSHORE SAT MORNING. VERY WARM AND UNSTABLE ATMOS FRI AFTN SUPPORTIVE OF PSBL SVR TSTMS BUT MAIN FORCING WITH FRONT WILL REMAIN UPSTREAM UNTIL EVENING. ISOLATED TO SCT CONVECTIVE ACTIVITY PSBL INLAND OF SEA BREEZE DURING AFTN...BUT BEST COVERAGE OF SHOWERS/TSTMS AND SVR POTENTIAL EXPECTED FRI NIGHT...MAINLY FOR WRN AND NRN SECTIONS DURING EVENING HOURS...AND OVERNIGHT ALONG COAST. SATURDAY THROUGH MONDAY...THE FRONT WILL MOVE OFF THE NC COAST BY MIDDAY SATURDAY AND CONTINUED TO INDICATE A DRIER TREND FOR SATURDAY AFTERNOON/EVENING. MAX TEMPS ABOUT 10 DEGS COOLER THAN FRIDAY WITH MID 70S INLAND TO LOWER 60S NORTHERN OBX. STRONG HIGH PRESSURE WILL EXTEND OVER THE AREA FROM THE MID-ATLANTIC STATES SAT NIGHT INTO SUNDAY AND GRADUALLY SHIFT OFF THE MID-ATLANTIC COAST SUN NIGHT. DRY CONDITIONS EXPECTED WITH TEMPS NEAR NORMAL SATURDAY NIGHT THROUGH SUNDAY NIGHT. MONDAY THROUGH WEDNESDAY...LATEST GFS AND ECMWF CONTINUE TO INDICATE DRY CONDITIONS CONTINUING MONDAY INTO TUESDAY WITH SFC RIDGE EXTENDING OVER AREA FROM OFFSHORE. MSTR RETURNS TUE NIGHT INTO WED WITH SFC FLOW BECOMING SE-S AND DEEPER MSTR INCREASING ALOFT FROM SW. KEPT PREVIOUS FCST WITH SLIGHT CHC POPS DEVELOPING TUE NIGHT AND CONTINUING WED. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... SHORT TERM /THROUGH TONIGHT/... AS OF 10 AM THURSDAY...MAIN CHANGE WAS TO REMOVE IFR CIGS FROM OAJ AND HAVE TSRA IN FCST UNTIL ABT 16Z. WIDESPREAD LIFR/IFR CONDITIONS WILL PREVAIL THROUGH MOST IF NOT ALL OF THE MORNING HOURS ACCORDING TO THE NARRE AND HRRR AVIATION GUIDANCE ALONG WITH LAMP MOS. IFR CONDITIONS WILL IMPROVE TO VFR THIS AFTERNOON BUT RETREATING WARM FRONT AND HEATING WILL QUICKLY DESTABILIZE THE ATMOSPHERE AND WILL RESULT IN THE DEVELOPMENT OF SCATTERED STRONG THUNDERSTORMS WITH BRIEF IFR CONDITIONS IN THE AFTERNOON/EARLY EVENING. THE FORECAST SOUNDINGS ARE AGAIN FORECASTING A SATURATED BOUNDARY LAYER TONIGHT WITH IFR CEILINGS BUT CONFIDENCE IN THIS BELOW NORMAL AT THIS TIME. LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 400 AM THURSDAY...VFR EXPECTED FRIDAY THEN HIGHER THREAT OF SUB-VFR CONDITIONS FRI NIGHT INTO EARLY SAT WITH GOOD COVERAGE OF SHOWERS AND TSTMS EXPECTED AS STRONG FRONT MOVES ACROSS EASTERN NC TAF SITES. GUSTY SW WINDS 15-25 MPH LIKELY FRIDAY AFTERNOON AND EVENING AHEAD OF FRONT. HIGH PRESSURE BUILDING SOUTH OVER THE REGION WILL ALLOW AVIATION CONDITIONS TO IMPROVE TO VFR SATURDAY EVENING THROUGH MONDAY. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 1000 AM THURSDAY...MAIN CHANGE TO INCREASE SEAS TO 5 FT ACRS THE NRN AND CNTRL CSTL WATERS THROUGH EARLY AFTN. DENSE FOG ADVISORY CONTS FOR THE WATERS THIS MORNING. THE FOG SHOULD DISSIPATE WITH SUSTAINED HEATING LATE THIS MORNING. BACK DOOR COLD FRONT HAS MOVED THROUGH THE NORTHERN AND CENTRAL WATERS INCLUDING THE SOUNDS AND IS STALLING AS FORECAST OVER THE SOUTHERN WATERS EARLY THIS MORNING. WINDS TO SHIFT EASTERLY TO 15 KT BEHIND THE FRONT. LATER TODAY WINDS GRADUALLY RETURN TO THE S-SW AS FRONT RETREATS BACK NORTH. TONIGHT SW WINDS WILL INCREASE TO 15 TO 20 KT LATE. SEAS 2 TO 4 FT TODAY WILL BUILD TO 3 TO 5 FT LATE TONIGHT. LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 400 AM THURSDAY...NO SIGNIFICANT CHANGES TO PREVIOUS FCST. TIGHTENING PRES GRADIENT AHEAD OF STRONG COLD FRONT WILL PRODUCE SW WINDS 15-25 KT FRIDAY INTO FRI NIGHT. SCA CONDITIONS LIKELY FOR OUTER WATERS AND PAMLICO SOUND. INITIAL SURGE OF NRLY WINDS WITH CAA IN WAKE OF FRONT WILL BE AROUND 15 KT AND LIMITED TO SAT MORNING. SLIGHTLY STRONGER SECONDARY SURGE OF NE WINDS 15-20 KT EXPECTED LATE SAT NIGHT INTO SUN AFTN. WINDS THEN DIMINISHING AND GRADUALLY VEERING TO SE SUN NIGHT AND MONDAY. BLEND OF PREVIOUS FCST...NWPS AND WW3 USED FOR SEAS. HEIGHTS BUILDING TO 6-7 FT FRI AFTN INTO FRI NIGHT....LOWERING SAT AND THEN BUILDING AGAIN SUNDAY WITH SECONDARY NE SURGE. LIGHTER WINDS WILL THEN ALLOW SEAS TO DROP TO AROUND 2 FT MONDAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...DENSE FOG ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ130-131- 135>137-150-152-154-156-158. && $$ SYNOPSIS...JME NEAR TERM...JAC/JME SHORT TERM...JME LONG TERM...JBM AVIATION...JAC/JME/JBM MARINE...JAC/JME/JBM
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
700 AM EDT THU APR 9 2015 .SYNOPSIS... A STALLED FRONT WILL BE OVER SOUTHERN SECTIONS THIS MORNING AND RETURN NORTH AS A WARM FRONT THIS AFTERNOON AND TONIGHT. A COLD FRONT WILL APPROACH FROM THE WEST LATE FRIDAY AND MOVE OFFSHORE SATURDAY MORNING. HIGH PRESSURE WILL EXTEND OVER THE AREA FROM THE NORTH SATURDAY NIGHT AND SUNDAY. A WARM FRONT WILL LIFT NORTH OF THE AREA TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 700 AM THURSDAY...THE BACK DOOR FRONT IS LOCATED VICINITY OF THE CRYSTAL COAST/SOUTHERN COASTAL PLAIN AND APPEARS TO HAVE STALLED AS FORECAST. THE FRONT WILL THEN DRIFT SLOWLY NORTH THIS AFTERNOON AND EVENING. CONVECTION CURRENTLY OVER THE COASTAL PLAIN IS INCREASING IN COVERAGE AND INTENSITY AND WILL NEED TO INCREASE POPS TO LIKELY FOR THE EARLY MORNING HOURS. NONE OF THE MODELS IS REALLY HANDLING THIS PRECIPITATION WELL BUT IT STILL LOOKS LIKE A LULL IN THE EARLY AFTERNOON HOURS THEN LATE THIS AFTERNOON INTO EARLY EVENING THE HIGH RESOLUTION NSSL WRF MODEL INDICATES STRONG CONVECTION REDEVELOPING WITH HEATING. THIS IS SUPPORTED SOMEWHAT BY THE LARGER SCALE MODELS SO WILL INCREASE POPS AGAIN DURING THIS TIME. ALTHOUGH WE ARE NOT OUTLOOKED BY THE SPC FOR SEVERE STORMS IT WILL BECOME MODERATELY UNSTABLE AND GIVEN THE THERMAL AND KINEMATIC PROFILES COMMON THIS TIME OF YEAR, STORMS COULD BRIEFLY BECOME SEVERE WITH DAMAGING WIND GUSTS AND LARGE HAIL POSSIBLE. WIDESPREAD STRATUS/PATCHY FOG WILL BE SLOW TO DISSIPATE TODAY AND COULD LINGER FOR MUCH OF THE MORNING. THERE SHOULD BE ENOUGH AFTERNOON HEATING TO REALIZE HIGHS INLAND IN THE LOWER 80S AND LOWER 70S SOUTHERN COAST BEACHES. ONSHORE FLOW ALONG THE OUTER BANKS OFF THE STILL CHILLY SHELF WATERS WILL PRODUCE HIGHS IN THE LOWER 60S NORTHERN SECTIONS AND MID TO UPPER 60S SOUTH. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/... AS OF 415 AM THURSDAY...THE WARM FRONT WILL MOVE NORTH OF THE AREA THIS EVENING. BEST CHANCE OF RAIN SHOULD BE IN THE EVENING THEN GUIDANCE INDICATES MID LEVEL DRYING THUS WILL FORECAST DRY CONDITIONS AFTER 06Z. THE PRESSURE GRADIENT TIGHTENS IN THE WARM SECTOR AND THERE SHOULD BE ENOUGH MIXING TO PRECLUDE ANY FOG DEVELOPMENT ALTHOUGH A SHALLOW NEAR SURFACE LAYER IS FORECAST TO BECOME SATURATED AND COULD SUPPORT THE DEVELOPMENT OF LOW CLOUDS. THE SOUTHERLY FLOW WILL LEAD TO VERY MILD LOW TEMPERATURES IN THE 60S. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... AS OF 400 AM THURSDAY...ONLY SIGNIFICANT CHANGE DURING PERIOD WAS TO LIMIT POPS ERN SECTIONS TO EARLY SAT MORNING...INDICATING DRY FCST OVER LAND AREAS AFTER 15Z. LATEST MODELS IN GOOD AGREEMENT WITH PREVIOUS FCST REST OF PERIOD. MAIN FEATURE DURING PERIOD WILL BE STRONG COLD FRONT THAT WILL MOVE INTO AREA FRI NIGHT AND OFFSHORE SAT MORNING. VERY WARM AND UNSTABLE ATMOS FRI AFTN SUPPORTIVE OF PSBL SVR TSTMS BUT MAIN FORCING WITH FRONT WILL REMAIN UPSTREAM UNTIL EVENING. ISOLATED TO SCT CONVECTIVE ACTIVITY PSBL INLAND OF SEA BREEZE DURING AFTN...BUT BEST COVERAGE OF SHOWERS/TSTMS AND SVR POTENTIAL EXPECTED FRI NIGHT...MAINLY FOR WRN AND NRN SECTIONS DURING EVENING HOURS...AND OVERNIGHT ALONG COAST. SATURDAY THROUGH MONDAY...THE FRONT WILL MOVE OFF THE NC COAST BY MIDDAY SATURDAY AND CONTINUED TO INDICATE A DRIER TREND FOR SATURDAY AFTERNOON/EVENING. MAX TEMPS ABOUT 10 DEGS COOLER THAN FRIDAY WITH MID 70S INLAND TO LOWER 60S NORTHERN OBX. STRONG HIGH PRESSURE WILL EXTEND OVER THE AREA FROM THE MID-ATLANTIC STATES SAT NIGHT INTO SUNDAY AND GRADUALLY SHIFT OFF THE MID-ATLANTIC COAST SUN NIGHT. DRY CONDITIONS EXPECTED WITH TEMPS NEAR NORMAL SATURDAY NIGHT THROUGH SUNDAY NIGHT. MONDAY THROUGH WEDNESDAY...LATEST GFS AND ECMWF CONTINUE TO INDICATE DRY CONDITIONS CONTINUING MONDAY INTO TUESDAY WITH SFC RIDGE EXTENDING OVER AREA FROM OFFSHORE. MSTR RETURNS TUE NIGHT INTO WED WITH SFC FLOW BECOMING SE-S AND DEEPER MSTR INCREASING ALOFT FROM SW. KEPT PREVIOUS FCST WITH SLIGHT CHC POPS DEVELOPING TUE NIGHT AND CONTINUING WED. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... SHORT TERM /THROUGH TONIGHT/... AS OF 700 AM THURSDAY...WIDESPREAD LIFR/IFR CONDITIONS WILL PREVAIL THROUGH MOST IF NOT ALL OF THE MORNING HOURS ACCORDING TO THE NARRE AND HRRR AVIATION GUIDANCE ALONG WITH LAMP MOS. IN ADDITION TO THE FOG AND STRATUS NUMEROUS SHOWERS AND THUNDERSTORMS WILL AFFECTING THE TAF SITES THROUGH ABOUT 14Z WITH DOWNPOURS AND GUSTY WINDS. CONDITIONS WILL IMPROVE TO VFR THIS AFTERNOON BUT RETREATING WARM FRONT AND HEATING WILL QUICKLY DESTABILIZE THE ATMOSPHERE AND WILL RESULT IN THE DEVELOPMENT OF SCATTERED STRONG THUNDERSTORMS WITH BRIEF IFR CONDITIONS IN THE AFTERNOON/EARLY EVENING. THE FORECAST SOUNDINGS ARE AGAIN FORECASTING A SATURATED BOUNDARY LAYER TONIGHT WITH IFR CEILINGS BUT CONFIDENCE IN THIS BELOW NORMAL AT THIS TIME. LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 400 AM THURSDAY...VFR EXPECTED FRIDAY THEN HIGHER THREAT OF SUB-VFR CONDITIONS FRI NIGHT INTO EARLY SAT WITH GOOD COVERAGE OF SHOWERS AND TSTMS EXPECTED AS STRONG FRONT MOVES ACROSS EASTERN NC TAF SITES. GUSTY SW WINDS 15-25 MPH LIKELY FRIDAY AFTERNOON AND EVENING AHEAD OF FRONT. HIGH PRESSURE BUILDING SOUTH OVER THE REGION WILL ALLOW AVIATION CONDITIONS TO IMPROVE TO VFR SATURDAY EVENING THROUGH MONDAY. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 700 AM THURSDAY...DENSE FOG INDICATED IN MARINE OBSERVATIONS HAS PROMPTED THE ISSUANCE OF DENSE FOG ADVISORY FOR ALL OF THE WATERS THIS MORNING. THE FOG SHOULD DISSIPATE WITH SUSTAINED HEATING LATE THIS MORNING. BACK DOOR COLD FRONT HAS MOVED THROUGH THE NORTHERN AND CENTRAL WATERS INCLUDING THE SOUNDS AND IS STALLING AS FORECAST OVER THE SOUTHERN WATERS EARLY THIS MORNING. WINDS TO SHIFT EASTERLY TO 15 KT BEHIND THE FRONT. LATER TODAY WINDS GRADUALLY RETURN TO THE S-SW AS FRONT RETREATS BACK NORTH. TONIGHT SW WINDS WILL INCREASE TO 15 TO 20 KT LATE. SEAS 2 TO 4 FT TODAY WILL BUILD TO 3 TO 5 FT LATE TONIGHT. LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 400 AM THURSDAY...NO SIGNIFICANT CHANGES TO PREVIOUS FCST. TIGHTENING PRES GRADIENT AHEAD OF STRONG COLD FRONT WILL PRODUCE SW WINDS 15-25 KT FRIDAY INTO FRI NIGHT. SCA CONDITIONS LIKELY FOR OUTER WATERS AND PAMLICO SOUND. INITIAL SURGE OF NRLY WINDS WITH CAA IN WAKE OF FRONT WILL BE AROUND 15 KT AND LIMITED TO SAT MORNING. SLIGHTLY STRONGER SECONDARY SURGE OF NE WINDS 15-20 KT EXPECTED LATE SAT NIGHT INTO SUN AFTN. WINDS THEN DIMINISHING AND GRADUALLY VEERING TO SE SUN NIGHT AND MONDAY. BLEND OF PREVIUOS FCST...NWPS AND WW3 USED FOR SEAS. HEIGHTS BUILDING TO 6-7 FT FRI AFTN INTO FRI NIGHT....LOWERING SAT AND THEN BUILDING AGAIN SUNDAY WITH SECONDARY NE SURGE. LIGHTER WINDS WILL THEN ALLOW SEAS TO DROP TO AROUND 2 FT MONDAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...DENSE FOG ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ130-131- 135>137-150-152-154-156-158. && $$ SYNOPSIS...JME NEAR TERM...JME SHORT TERM...JME LONG TERM...JBM AVIATION...JME/JBM MARINE...JME/JBM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
650 AM EDT THU APR 9 2015 .SYNOPSIS...A BACKDOOR COLD FRONT WILL SETTLE ACROSS NORTH CAROLINA TODAY... AND THEN RETREAT BACK NORTHWARD BY EARLY TONIGHT. BREEZY AND GUSTY SOUTHWEST WINDS FRIDAY WILL BRING INCREASED CHANCES FOR SHOWERS AND STORMS... AHEAD OF A COLD FRONT THAT WILL SWEEP THROUGH THE AREA LATE FRIDAY THROUGH FRIDAY NIGHT. HIGH PRESSURE WILL BUILD IN FOR THE WEEKEND. && .NEAR TERM /TODAY THROUGH TONIGHT/... AS OF 255 AM THURSDAY... SCATTERED SHOWERS AND STORMS CONTINUE TO FORM EARLY THIS MORNING OVER THE WRN AND SRN CWA... ALONG AND SOUTHWEST OF THE BACKDOOR FRONT/MERGED OUTFLOW (FROM LAST EVENING`S SUPERCELL) CURRENTLY SPRAWLED NW TO SE THROUGH CENTRAL NC. THIS CONVECTION IS TRAVELING WITH THE (WEAK) MEAN FLOW TOWARD THE ENE INTO THE MORE STABLE SURFACE-BASED AIR... WHICH SHOULD LIMIT ITS ABILITY TO INTENSIFY OVERNIGHT. BUT ELEVATED INSTABILITY PERSISTS WITH 500-1000 J/KG MUCAPE AND OBSERVED MID LEVEL LAPSE RATES OVER 7 C/KM... AND EFFECTIVE SHEAR HOLDS AT 30-40 KTS ALONG THE CAPE GRADIENT WITH OBSERVED HIGH MOISTURE TRANSPORT IN THE LOW LEVELS AND PW OVER 150% OF NORMAL. THESE FACTORS WILL CONTINUE TO SUPPORT SCATTERED PULSING SHOWERS/STORMS ESPECIALLY ACROSS THE WRN AND SRN CWA... ALONG AND SW OF THE FRONT/OUTFLOW... WITH LESSER COVERAGE TO THE NORTH AND EAST WHERE INSTABILITY IS MORE ELEVATED. HOWEVER... WE WILL NEED TO WATCH THE CONVECTIVE COMPLEX NOW OVER WRN VA TO ENSURE THAT ITS COLD POOL AND MID LEVEL MCV DOES NOT PROPAGATE TOO FAR SE TOWARD OUR NE CWA OVER THE NEXT SEVERAL HOURS... AS WAS INDICATED BY EARLIER HRRR RUNS AND HINTED AT BY THE LATEST NAM. AFTER THIS MCV SHIFTS EASTWARD OFF THE VA COAST AS IT IS EXPECTED TO DO BY MID MORNING... LARGE SCALE FALLING HEIGHTS OVER THE NRN PLAINS INTO THE UPPER MIDWEST THIS MORNING SHOULD FORCE GRADUAL RISES IN HEIGHTS DOWNSTREAM OVER THE MIDATLANTIC AND SOUTHEAST BY LATER TODAY... LEADING TO A SLIGHT DECREASE IN DEEP LAYER SHEAR. BUT WE SHOULD MAINTAIN AT LEAST MODERATE INSTABILITY ALONG AND SOUTHWEST OF THE FRONTAL ZONE... WHICH IS EXPECTED TO MOVE OR JUMP BACK NORTHEAST LATE TODAY OR THIS EVENING... WITH MID LEVEL LAPSE RATES EXPECTED TO HOLD AT 6.5-7.0 C/KM... MUCAPE UP TO 1500-2500 J/KG (ACCORDING TO THE NAM)... AND WHAT SHOULD STILL BE SUFFICIENT EFFECTIVE DEEP LAYER SHEAR TO SUPPORT CONVECTION. THE NAM CONCENTRATES THE BETTER CONVECTION COVERAGE ALONG AND JUST SW OF THE FRONT FROM THE TRIAD REGION ACROSS CENTRAL NC THROUGH THE CENTRAL COASTAL PLAIN TODAY... AND THIS LOOKS VERY REASONABLE. WILL HAVE A 40-60% POP MAINLY FROM LATE MORNING THROUGH THE AFTERNOON WITH THE HIGHER-END POPS ORIENTED IN A BAND NW TO SE FROM AROUND INT TO GSB. A STRONG TO POSSIBLY SEVERE STORM OR TWO REMAINS POSSIBLE TODAY GIVEN THE ANTICIPATED CONVECTIVE PARAMETERS. WHILE WE DON`T EXPECT A WIDESPREAD SEVERE THREAT TODAY WITH THE RISE IN MID LEVEL HEIGHTS... MODELS DO INDICATE AN UPPER DIVERGENCE MAX LATER TODAY OVER CENTRAL NC... AND THIS PLUS HIGH PW VALUES SUGGEST POTENTIAL FOR A FEW STRONG CELLS AND SLOW-MOVING HEAVY RAINERS. BY TONIGHT... WE SHOULD SEE THE HIGHER COVERAGE TRANSITION INTO THE NW CWA... AS THIS IS WHERE THE SHEAR WILL STRENGTHEN AND BECOME MORE SUPPORTIVE OF CONVECTION... WHEREAS SOUTHEAST SECTIONS WILL BE MORE UNDER THE INFLUENCE OF THE BUILDING RIDGE ALONG THE SOUTHEAST COAST WITH WEAKER SHEAR. THE SLIGHTLY DRIER AIR NOW NOTED IN BLENDED TPW IMAGERY NORTH AND NE OF THE BAHAMAS WILL BE DRAWN NORTHWARD INTO ERN NC AS WELL... LIKELY LEADING TO LOWER COVERAGE OF SHOWERS AND ISOLATED STORMS SE OF THE TRIANGLE AS WE HEAD INTO TONIGHT. EXPECT HIGHS OF 80-85 OVER THE SW HALF WITH COOLER MID-UPPER 70S NE OF THE FRONT WHERE LOW CLOUDS WILL LINGER THE LONGEST BEFORE STARTING TO THIN AND MIX OUT. WARM LOWS TONIGHT MAINLY IN THE MID 60S AS WE`LL BE FULLY IN THE PREFRONTAL WARM SECTOR. -GIH && .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... AS OF 325 AM THURSDAY... MID LEVEL MULTI-STREAM ENERGY WILL PHASE INTO AN INTENSIFYING MID LEVEL LOW OVER THE NRN GREAT LAKES FRI AND PUSH A COLD FRONT ESE... REACHING THE SPINE OF THE APPALACHIANS BY EARLY FRI AFTERNOON. THIS FRONT WILL THEN PUSH SE THROUGH CENTRAL NC FROM EARLY EVENING THROUGH FRI NIGHT... PROPELLED BY THE PASSAGE OF THE MID LEVEL LOW OVER SRN QUEBEC AND BY COOL HIGH PRESSURE BUILDING IN FROM THE MID MISS VALLEY. LOW LEVEL SW WINDS WILL INCREASE AHEAD OF THE FRONT WITH SUSTAINED WINDS INTO THE TEENS AND POTENTIAL GUSTS UP TO 25-30 KTS AS INDICATED BY LOW LEVEL MOMENTUM TRANSPORT NOTED ON FORECAST BUFR SOUNDINGS. EXPECT A RELATIVE LULL IN PRECIP FRI MORNING... A FUNCTION OF RISING HEIGHTS ALOFT OVER THE ERN CAROLINAS AND BRIEF WEAK SUBSIDENCE DOWNSTREAM OF INCREASING PREFRONTAL CONVECTION TO OUR WEST FROM OH THROUGH KY/TN TO MS/LA. BUT WILL HAVE POPS RISING TO LIKELY IN THE NW FRI AFTERNOON AS THE FRONT APPROACHES... AND INTO THE EASTERN CWA FRI EVENING BEFORE TRENDING DRY FROM NW TO SE LATE. BASED ON EXPECTED VERY HIGH PW (OVER 200% OF NORMAL)... STRONG LOW LEVEL MOISTURE TRANSPORT... AND A RESUMPTION OF STRONG UPPER DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A 110+ KT JET STREAK... POPS MAY NEED TO BE BUMPED UP TO CATEGORICAL LATER TODAY. THICKNESSES AND STATISTICAL GUIDANCE INDICATE HIGHS FROM 80-85 (WARMEST SE). LOWS FROM THE LOW 50S NW TO THE LOW 60S SE WHERE THE FRONT MAY NOT CLEAR UNTIL LATE. -GIH && .LONG TERM /SATURDAY THROUGH THURSDAY/... AS OF 350 AM THURSDAY... SATURDAY THROUGH SUNDAY NIGHT: THE COLD FRONT SHOULD BE THROUGH CENTRAL NC AND ALONG THE NC COAST BY 12Z SATURDAY. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT...LINGERING OVER THE AREA THROUGH THE WEEKEND AND RESULTING IN FAIR WEATHER AND NEAR NORMAL TEMPERATURES. HIGHS IN THE LOW TO MID 70S AND LOWS IN THE MID TO UPPER 40S SATURDAY NIGHT...INCREASING TO THE UPPER 40S TO MID 50S SUNDAY NIGHT. MONDAY THROUGH THURSDAY: A WEAK RIDGE WILL LINGER OVER THE AREA ON MONDAY AND MONDAY NIGHT AS THE HIGH MOVES OFFSHORE AND ANOTHER COLD FRONT APPROACHES. THE FRONT WILL BECOME MORE WEST-EAST ORIENTED ON TUESDAY AND IS EXPECTED TO SLIDE SOUTHWARD INTO CENTRAL NC LATE TUESDAY/TUESDAY NIGHT. MONDAY AND MONDAY NIGHT SHOULD REMAIN DRY... WITH HIGHS IN THE MID 70S AND LOWS IN THE UPPER 50S TO LOW 60S. THERE IS STILL SOME UNCERTAINTY THROUGH THE REMAINDER OF THE PERIOD WITH RESPECT TO THE TIMING AND COVERAGE OF PRECIPITATION MOVING INTO AND LINGERING OVER THE AREA. IF THE RIDGE HOLDS THE BACKDOOR FRONT AT BAY LONGER THAN THE MODELS ARE PREDICTING THEN MUCH OF TUESDAY COULD REMAIN DRY...HOWEVER GIVEN THE UNCERTAINTY WILL KEEP A SLIGHT CHANCE OF SHOWERS IN FOR TUESDAY AND TUESDAY NIGHT. ALTHOUGH THE MODELS WANT TO KEEP LINGERING RAIN IN THROUGH WEDNESDAY AFTERNOON... WILL KEEP THAT PART OF THE FORECAST DRY UNTIL THERE IS BETTER AGREEMENT AND HIGHER CONFIDENCE. HIGHS WILL GENERALLY BE IN THE MID TO UPPER 70S AND LOWS WEDNESDAY NIGHT IN TEH MID 50S. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... AS OF 650 AM THURSDAY... PRIMARY AVIATION CONCERN NEXT 24 HRS: IFR/LIFR CIGS THROUGH THE MORNING AT RWI/RDU/GSO/INT WITH LESSER CHANCES AT FAY. A SMALL BUT POTENT STORM COMPLEX THAT MOVED SE OVER NRN AND ERN PORTIONS OF CENTRAL NC LAST EVENING HELPED DRAW A BACKDOOR COLD FRONT SOUTHWESTWARD WELL INTO CENTRAL NC... WITH LOW CLOUDS BASED UNDER 1000 FT AGL AND NORTHEASTERLY WINDS HAVING SPREAD INTO NRN/ERN NC FROM VA OVERNIGHT. SCATTERED STORMS AFFECTED MOST CENTRAL NC TAF SITES OVERNIGHT WITH SHORT-LIVED MVFR VSBYS AND HEAVY DOWNPOURS. THE CURRENT IFR/LIFR CIGS SHOULD RISE TO MVFR BY LATE MORNING TO EARLY AFTERNOON... THEN TO VFR BY MID AFTERNOON... WITH ANOTHER BATCH OF SCATTERED SHOWERS AND STORMS ORIENTED NW TO SE OVER CENTRAL NC DEVELOPING BY MID TO LATE AFTERNOON. UNCERTAINTY REGARDING PRECISELY WHERE THESE STORMS MIGHT FORM AND WHEN... AS WELL AS THE POTENTIAL FOR LOWER-THAN-EXPECTED COVERAGE... PRECLUDES MENTIONING THEM IN THE TAFS AT THIS TIME. BUT AVIATORS SHOULD BE AWARE OF THE POSSIBILITY OF STORMS... AND THE VARIABLE GUSTY WINDS AND SUB-VFR DOWNPOURS THAT OFTEN ACCOMPANY THEM... BOTH IN THE PREDAWN HOURS AND THIS AFTERNOON/EARLY EVENING. PATCHY FOG AND AREAS OF IFR/LIFR STRATUS ARE LIKELY DURING THE LAST 6 HOURS OF THE TAF VALID PERIOD... PARTICULARLY IN THOSE LOCATIONS THAT SEE PRECIPITATION TODAY. LOOKING BEYOND 12Z EARLY FRI MORNING: SUB-VFR STRATUS AND PATCHY FOG SHOULD MIX UP TO VFR BY MID MORNING. A BREEZE FROM THE SW AT 10-20 KT RAMPING UP TOWARD MIDDAY FRI MAY GUST UP TO AROUND 25 KTS FRI AFTERNOON. THIS WILL OCCUR AHEAD OF A COLD FRONT THAT IS EXPECTED TO PUSH SE THROUGH CENTRAL NC BETWEEN 00Z AND 09Z SAT. WIDESPREAD SHOWERS AND STORMS WITH SUB-VFR CONDITIONS IS LIKELY AHEAD OF THE FRONT FROM MID AFTERNOON FRI THROUGH FRI NIGHT. VFR CONDITIONS ARE LIKELY FROM SAT MORNING THROUGH MON... AS HIGH PRESSURE BUILDS OVER THE MIDATLANTIC REGION OVER THE WEEKEND THEN SHIFTS OFFSHORE BY MON. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...HARTFIELD LONG TERM...RAH AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
351 AM EDT THU APR 9 2015 .SYNOPSIS...A BACKDOOR COLD FRONT WILL SETTLE ACROSS NORTH CAROLINA TODAY... AND THEN RETREAT BACK NORTHWARD BY EARLY TONIGHT. BREEZY AND GUSTY SOUTHWEST WINDS FRIDAY WILL BRING INCREASED CHANCES FOR SHOWERS AND STORMS... AHEAD OF A COLD FRONT THAT WILL SWEEP THROUGH THE AREA LATE FRIDAY THROUGH FRIDAY NIGHT. HIGH PRESSURE WILL BUILD IN FOR THE WEEKEND. && .NEAR TERM /TODAY THROUGH TONIGHT/... AS OF 255 AM THURSDAY... SCATTERED SHOWERS AND STORMS CONTINUE TO FORM EARLY THIS MORNING OVER THE WRN AND SRN CWA... ALONG AND SOUTHWEST OF THE BACKDOOR FRONT/MERGED OUTFLOW (FROM LAST EVENING`S SUPERCELL) CURRENTLY SPRAWLED NW TO SE THROUGH CENTRAL NC. THIS CONVECTION IS TRAVELING WITH THE (WEAK) MEAN FLOW TOWARD THE ENE INTO THE MORE STABLE SURFACE-BASED AIR... WHICH SHOULD LIMIT ITS ABILITY TO INTENSIFY OVERNIGHT. BUT ELEVATED INSTABILITY PERSISTS WITH 500-1000 J/KG MUCAPE AND OBSERVED MID LEVEL LAPSE RATES OVER 7 C/KM... AND EFFECTIVE SHEAR HOLDS AT 30-40 KTS ALONG THE CAPE GRADIENT WITH OBSERVED HIGH MOISTURE TRANSPORT IN THE LOW LEVELS AND PW OVER 150% OF NORMAL. THESE FACTORS WILL CONTINUE TO SUPPORT SCATTERED PULSING SHOWERS/STORMS ESPECIALLY ACROSS THE WRN AND SRN CWA... ALONG AND SW OF THE FRONT/OUTFLOW... WITH LESSER COVERAGE TO THE NORTH AND EAST WHERE INSTABILITY IS MORE ELEVATED. HOWEVER... WE WILL NEED TO WATCH THE CONVECTIVE COMPLEX NOW OVER WRN VA TO ENSURE THAT ITS COLD POOL AND MID LEVEL MCV DOES NOT PROPAGATE TOO FAR SE TOWARD OUR NE CWA OVER THE NEXT SEVERAL HOURS... AS WAS INDICATED BY EARLIER HRRR RUNS AND HINTED AT BY THE LATEST NAM. AFTER THIS MCV SHIFTS EASTWARD OFF THE VA COAST AS IT IS EXPECTED TO DO BY MID MORNING... LARGE SCALE FALLING HEIGHTS OVER THE NRN PLAINS INTO THE UPPER MIDWEST THIS MORNING SHOULD FORCE GRADUAL RISES IN HEIGHTS DOWNSTREAM OVER THE MIDATLANTIC AND SOUTHEAST BY LATER TODAY... LEADING TO A SLIGHT DECREASE IN DEEP LAYER SHEAR. BUT WE SHOULD MAINTAIN AT LEAST MODERATE INSTABILITY ALONG AND SOUTHWEST OF THE FRONTAL ZONE... WHICH IS EXPECTED TO MOVE OR JUMP BACK NORTHEAST LATE TODAY OR THIS EVENING... WITH MID LEVEL LAPSE RATES EXPECTED TO HOLD AT 6.5-7.0 C/KM... MUCAPE UP TO 1500-2500 J/KG (ACCORDING TO THE NAM)... AND WHAT SHOULD STILL BE SUFFICIENT EFFECTIVE DEEP LAYER SHEAR TO SUPPORT CONVECTION. THE NAM CONCENTRATES THE BETTER CONVECTION COVERAGE ALONG AND JUST SW OF THE FRONT FROM THE TRIAD REGION ACROSS CENTRAL NC THROUGH THE CENTRAL COASTAL PLAIN TODAY... AND THIS LOOKS VERY REASONABLE. WILL HAVE A 40-60% POP MAINLY FROM LATE MORNING THROUGH THE AFTERNOON WITH THE HIGHER-END POPS ORIENTED IN A BAND NW TO SE FROM AROUND INT TO GSB. A STRONG TO POSSIBLY SEVERE STORM OR TWO REMAINS POSSIBLE TODAY GIVEN THE ANTICIPATED CONVECTIVE PARAMETERS. WHILE WE DON`T EXPECT A WIDESPREAD SEVERE THREAT TODAY WITH THE RISE IN MID LEVEL HEIGHTS... MODELS DO INDICATE AN UPPER DIVERGENCE MAX LATER TODAY OVER CENTRAL NC... AND THIS PLUS HIGH PW VALUES SUGGEST POTENTIAL FOR A FEW STRONG CELLS AND SLOW-MOVING HEAVY RAINERS. BY TONIGHT... WE SHOULD SEE THE HIGHER COVERAGE TRANSITION INTO THE NW CWA... AS THIS IS WHERE THE SHEAR WILL STRENGTHEN AND BECOME MORE SUPPORTIVE OF CONVECTION... WHEREAS SOUTHEAST SECTIONS WILL BE MORE UNDER THE INFLUENCE OF THE BUILDING RIDGE ALONG THE SOUTHEAST COAST WITH WEAKER SHEAR. THE SLIGHTLY DRIER AIR NOW NOTED IN BLENDED TPW IMAGERY NORTH AND NE OF THE BAHAMAS WILL BE DRAWN NORTHWARD INTO ERN NC AS WELL... LIKELY LEADING TO LOWER COVERAGE OF SHOWERS AND ISOLATED STORMS SE OF THE TRIANGLE AS WE HEAD INTO TONIGHT. EXPECT HIGHS OF 80-85 OVER THE SW HALF WITH COOLER MID-UPPER 70S NE OF THE FRONT WHERE LOW CLOUDS WILL LINGER THE LONGEST BEFORE STARTING TO THIN AND MIX OUT. WARM LOWS TONIGHT MAINLY IN THE MID 60S AS WE`LL BE FULLY IN THE PREFRONTAL WARM SECTOR. -GIH && .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... AS OF 325 AM THURSDAY... MID LEVEL MULTI-STREAM ENERGY WILL PHASE INTO AN INTENSIFYING MID LEVEL LOW OVER THE NRN GREAT LAKES FRI AND PUSH A COLD FRONT ESE... REACHING THE SPINE OF THE APPALACHIANS BY EARLY FRI AFTERNOON. THIS FRONT WILL THEN PUSH SE THROUGH CENTRAL NC FROM EARLY EVENING THROUGH FRI NIGHT... PROPELLED BY THE PASSAGE OF THE MID LEVEL LOW OVER SRN QUEBEC AND BY COOL HIGH PRESSURE BUILDING IN FROM THE MID MISS VALLEY. LOW LEVEL SW WINDS WILL INCREASE AHEAD OF THE FRONT WITH SUSTAINED WINDS INTO THE TEENS AND POTENTIAL GUSTS UP TO 25-30 KTS AS INDICATED BY LOW LEVEL MOMENTUM TRANSPORT NOTED ON FORECAST BUFR SOUNDINGS. EXPECT A RELATIVE LULL IN PRECIP FRI MORNING... A FUNCTION OF RISING HEIGHTS ALOFT OVER THE ERN CAROLINAS AND BRIEF WEAK SUBSIDENCE DOWNSTREAM OF INCREASING PREFRONTAL CONVECTION TO OUR WEST FROM OH THROUGH KY/TN TO MS/LA. BUT WILL HAVE POPS RISING TO LIKELY IN THE NW FRI AFTERNOON AS THE FRONT APPROACHES... AND INTO THE EASTERN CWA FRI EVENING BEFORE TRENDING DRY FROM NW TO SE LATE. BASED ON EXPECTED VERY HIGH PW (OVER 200% OF NORMAL)... STRONG LOW LEVEL MOISTURE TRANSPORT... AND A RESUMPTION OF STRONG UPPER DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A 110+ KT JET STREAK... POPS MAY NEED TO BE BUMPED UP TO CATEGORICAL LATER TODAY. THICKNESSES AND STATISTICAL GUIDANCE INDICATE HIGHS FROM 80-85 (WARMEST SE). LOWS FROM THE LOW 50S NW TO THE LOW 60S SE WHERE THE FRONT MAY NOT CLEAR UNTIL LATE. -GIH && .LONG TERM /SATURDAY THROUGH THURSDAY/... AS OF 350 AM THURSDAY... SATURDAY THROUGH SUNDAY NIGHT: THE COLD FRONT SHOULD BE THROUGH CENTRAL NC AND ALONG THE NC COAST BY 12Z SATURDAY. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT...LINGERING OVER THE AREA THROUGH THE WEEKEND AND RESULTING IN FAIR WEATHER AND NEAR NORMAL TEMPERATURES. HIGHS IN THE LOW TO MID 70S AND LOWS IN THE MID TO UPPER 40S SATURDAY NIGHT...INCREASING TO THE UPPER 40S TO MID 50S SUNDAY NIGHT. MONDAY THROUGH THURSDAY: A WEAK RIDGE WILL LINGER OVER THE AREA ON MONDAY AND MONDAY NIGHT AS THE HIGH MOVES OFFSHORE AND ANOTHER COLD FRONT APPROACHES. THE FRONT WILL BECOME MORE WEST-EAST ORIENTED ON TUESDAY AND IS EXPECTED TO SLIDE SOUTHWARD INTO CENTRAL NC LATE TUESDAY/TUESDAY NIGHT. MONDAY AND MONDAY NIGHT SHOULD REMAIN DRY... WITH HIGHS IN THE MID 70S AND LOWS IN THE UPPER 50S TO LOW 60S. THERE IS STILL SOME UNCERTAINTY THROUGH THE REMAINDER OF THE PERIOD WITH RESPECT TO THE TIMING AND COVERAGE OF PRECIPITATION MOVING INTO AND LINGERING OVER THE AREA. IF THE RIDGE HOLDS THE BACKDOOR FRONT AT BAY LONGER THAN THE MODELS ARE PREDICTING THEN MUCH OF TUESDAY COULD REMAIN DRY...HOWEVER GIVEN THE UNCERTAINTY WILL KEEP A SLIGHT CHANCE OF SHOWERS IN FOR TUESDAY AND TUESDAY NIGHT. ALTHOUGH THE MODELS WANT TO KEEP LINGERING RAIN IN THROUGH WEDNESDAY AFTERNOON... WILL KEEP THAT PART OF THE FORECAST DRY UNTIL THERE IS BETTER AGREEMENT AND HIGHER CONFIDENCE. HIGHS WILL GENERALLY BE IN THE MID TO UPPER 70S AND LOWS WEDNESDAY NIGHT IN TEH MID 50S. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 1230 AM THURSDAY... PRIMARY AVIATION CONCERN NEXT 24 HRS: POTENTIAL FOR IFR/LIFR CIGS THROUGH LATE MORNING AT RWI/RDU WITH LESSER CHANCES AT GSO/INT/FAY. A SMALL BUT POTENT STORM COMPLEX THAT MOVED SE OVER NRN AND ERN PORTIONS OF CENTRAL NC THIS PAST EVENING HELPED DRAW A BACKDOOR COLD FRONT SOUTHWESTWARD WELL INTO CENTRAL NC. WINDS BEHIND THE FRONT ARE SHIFTING TO BE FROM THE EAST AND NE... AND LOW CLOUDS BASED UNDER 1000 FT AGL ARE EXPECTED TO SPREAD FROM SOUTH CENTRAL AND SE VA TOWARD THE SOUTH AND SW OVERNIGHT. HIGHEST CONFIDENCE IN IFR/LIFR CIGS IS AT RWI FOLLOWED BY RDU THEN GSO/INT/FAY. A FEW ADDITIONAL SHOWERS AND STORMS ARE POSSIBLE THROUGH DAYBREAK MAINLY OVER THE FAR NORTH AND EAST... FROM GSO TO RDU/RWI/FAY... BUT MOST PLACES WILL REMAIN DRY OVERNIGHT. VSBYS ARE EXPECTED TO DROP TO MVFR BUT AT THIS TIME DON`T LOOK LIKELY TO DROP DOWN TO IFR. CIGS SHOULD RISE TO MVFR BY LATE MORNING THEN TO VFR BY EARLY AFTERNOON... WITH ANOTHER BATCH OF SCATTERED SHOWERS AND STORMS ORIENTED NW TO SE OVER CENTRAL NC DEVELOPING BY MID TO LATE AFTERNOON. UNCERTAINTY REGARDING PRECISELY WHERE THESE STORMS MIGHT FORM AND WHEN... AS WELL AS THE POTENTIAL FOR LOWER-THAN-EXPECTED COVERAGE... PRECLUDES MENTIONING THEM IN THE TAFS AT THIS TIME. BUT AVIATORS SHOULD BE AWARE OF THE POSSIBILITY OF STORMS... AND THE VARIABLE GUSTY WINDS AND SUB-VFR DOWNPOURS THAT OFTEN ACCOMPANY THEM... BOTH IN THE PREDAWN HOURS AND THIS AFTERNOON/EARLY EVENING. PATCHY FOG AND AREAS OF IFR/LIFR STRATUS ARE LIKELY TOWARD THE END OF THE TAF VALID PERIOD PARTICULARLY IN THOSE LOCATIONS THAT SEE PRECIPITATION TODAY. LOOKING BEYOND 06Z EARLY FRI MORNING: SUB-VFR STRATUS AND PATCHY FOG SHOULD PERSIST THROUGH DAYBREAK FRI... BEFORE MIXING UP TO VFR BY MID MORNING. A BREEZE FROM THE SW AT 10-20 KT RAMPING UP TOWARD MIDDAY FRI MAY GUST UP TO AROUND 25 KTS FRI AFTERNOON. THIS WILL OCCUR AHEAD OF A COLD FRONT THAT IS EXPECTED TO PUSH SE THROUGH CENTRAL NC BETWEEN 00Z AND 09Z SAT. WIDESPREAD SHOWERS AND STORMS WITH SUB-VFR CONDITIONS IS LIKELY AHEAD OF THE FRONT FROM MID AFTERNOON FRI THROUGH FRI NIGHT. VFR CONDITIONS ARE LIKELY FROM SAT MORNING THROUGH MON... AS HIGH PRESSURE BUILDS OVER THE MIDATLANTIC REGION OVER THE WEEKEND THEN SHIFTS OFFSHORE BY MON. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...HARTFIELD LONG TERM...RAH AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
325 AM EDT THU APR 9 2015 .SYNOPSIS...A BACKDOOR COLD FRONT WILL SETTLE ACROSS NORTH CAROLINA TODAY... AND THEN RETREAT BACK NORTHWARD BY EARLY TONIGHT. BREEZY AND GUSTY SOUTHWEST WINDS FRIDAY WILL BRING INCREASED CHANCES FOR SHOWERS AND STORMS... AHEAD OF A COLD FRONT THAT WILL SWEEP THROUGH THE AREA LATE FRIDAY THROUGH FRIDAY NIGHT. HIGH PRESSURE WILL BUILD IN FOR THE WEEKEND. && .NEAR TERM /TODAY THROUGH TONIGHT/... AS OF 255 AM THURSDAY... SCATTERED SHOWERS AND STORMS CONTINUE TO FORM EARLY THIS MORNING OVER THE WRN AND SRN CWA... ALONG AND SOUTHWEST OF THE BACKDOOR FRONT/MERGED OUTFLOW (FROM LAST EVENING`S SUPERCELL) CURRENTLY SPRAWLED NW TO SE THROUGH CENTRAL NC. THIS CONVECTION IS TRAVELING WITH THE (WEAK) MEAN FLOW TOWARD THE ENE INTO THE MORE STABLE SURFACE-BASED AIR... WHICH SHOULD LIMIT ITS ABILITY TO INTENSIFY OVERNIGHT. BUT ELEVATED INSTABILITY PERSISTS WITH 500-1000 J/KG MUCAPE AND OBSERVED MID LEVEL LAPSE RATES OVER 7 C/KM... AND EFFECTIVE SHEAR HOLDS AT 30-40 KTS ALONG THE CAPE GRADIENT WITH OBSERVED HIGH MOISTURE TRANSPORT IN THE LOW LEVELS AND PW OVER 150% OF NORMAL. THESE FACTORS WILL CONTINUE TO SUPPORT SCATTERED PULSING SHOWERS/STORMS ESPECIALLY ACROSS THE WRN AND SRN CWA... ALONG AND SW OF THE FRONT/OUTFLOW... WITH LESSER COVERAGE TO THE NORTH AND EAST WHERE INSTABILITY IS MORE ELEVATED. HOWEVER... WE WILL NEED TO WATCH THE CONVECTIVE COMPLEX NOW OVER WRN VA TO ENSURE THAT ITS COLD POOL AND MID LEVEL MCV DOES NOT PROPAGATE TOO FAR SE TOWARD OUR NE CWA OVER THE NEXT SEVERAL HOURS... AS WAS INDICATED BY EARLIER HRRR RUNS AND HINTED AT BY THE LATEST NAM. AFTER THIS MCV SHIFTS EASTWARD OFF THE VA COAST AS IT IS EXPECTED TO DO BY MID MORNING... LARGE SCALE FALLING HEIGHTS OVER THE NRN PLAINS INTO THE UPPER MIDWEST THIS MORNING SHOULD FORCE GRADUAL RISES IN HEIGHTS DOWNSTREAM OVER THE MIDATLANTIC AND SOUTHEAST BY LATER TODAY... LEADING TO A SLIGHT DECREASE IN DEEP LAYER SHEAR. BUT WE SHOULD MAINTAIN AT LEAST MODERATE INSTABILITY ALONG AND SOUTHWEST OF THE FRONTAL ZONE... WHICH IS EXPECTED TO MOVE OR JUMP BACK NORTHEAST LATE TODAY OR THIS EVENING... WITH MID LEVEL LAPSE RATES EXPECTED TO HOLD AT 6.5-7.0 C/KM... MUCAPE UP TO 1500-2500 J/KG (ACCORDING TO THE NAM)... AND WHAT SHOULD STILL BE SUFFICIENT EFFECTIVE DEEP LAYER SHEAR TO SUPPORT CONVECTION. THE NAM CONCENTRATES THE BETTER CONVECTION COVERAGE ALONG AND JUST SW OF THE FRONT FROM THE TRIAD REGION ACROSS CENTRAL NC THROUGH THE CENTRAL COASTAL PLAIN TODAY... AND THIS LOOKS VERY REASONABLE. WILL HAVE A 40-60% POP MAINLY FROM LATE MORNING THROUGH THE AFTERNOON WITH THE HIGHER-END POPS ORIENTED IN A BAND NW TO SE FROM AROUND INT TO GSB. A STRONG TO POSSIBLY SEVERE STORM OR TWO REMAINS POSSIBLE TODAY GIVEN THE ANTICIPATED CONVECTIVE PARAMETERS. WHILE WE DON`T EXPECT A WIDESPREAD SEVERE THREAT TODAY WITH THE RISE IN MID LEVEL HEIGHTS... MODELS DO INDICATE AN UPPER DIVERGENCE MAX LATER TODAY OVER CENTRAL NC... AND THIS PLUS HIGH PW VALUES SUGGEST POTENTIAL FOR A FEW STRONG CELLS AND SLOW-MOVING HEAVY RAINERS. BY TONIGHT... WE SHOULD SEE THE HIGHER COVERAGE TRANSITION INTO THE NW CWA... AS THIS IS WHERE THE SHEAR WILL STRENGTHEN AND BECOME MORE SUPPORTIVE OF CONVECTION... WHEREAS SOUTHEAST SECTIONS WILL BE MORE UNDER THE INFLUENCE OF THE BUILDING RIDGE ALONG THE SOUTHEAST COAST WITH WEAKER SHEAR. THE SLIGHTLY DRIER AIR NOW NOTED IN BLENDED TPW IMAGERY NORTH AND NE OF THE BAHAMAS WILL BE DRAWN NORTHWARD INTO ERN NC AS WELL... LIKELY LEADING TO LOWER COVERAGE OF SHOWERS AND ISOLATED STORMS SE OF THE TRIANGLE AS WE HEAD INTO TONIGHT. EXPECT HIGHS OF 80-85 OVER THE SW HALF WITH COOLER MID-UPPER 70S NE OF THE FRONT WHERE LOW CLOUDS WILL LINGER THE LONGEST BEFORE STARTING TO THIN AND MIX OUT. WARM LOWS TONIGHT MAINLY IN THE MID 60S AS WE`LL BE FULLY IN THE PREFRONTAL WARM SECTOR. -GIH && .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... AS OF 325 AM THURSDAY... MID LEVEL MULTI-STREAM ENERGY WILL PHASE INTO AN INTENSIFYING MID LEVEL LOW OVER THE NRN GREAT LAKES FRI AND PUSH A COLD FRONT ESE... REACHING THE SPINE OF THE APPALACHIANS BY EARLY FRI AFTERNOON. THIS FRONT WILL THEN PUSH SE THROUGH CENTRAL NC FROM EARLY EVENING THROUGH FRI NIGHT... PROPELLED BY THE PASSAGE OF THE MID LEVEL LOW OVER SRN QUEBEC AND BY COOL HIGH PRESSURE BUILDING IN FROM THE MID MISS VALLEY. LOW LEVEL SW WINDS WILL INCREASE AHEAD OF THE FRONT WITH SUSTAINED WINDS INTO THE TEENS AND POTENTIAL GUSTS UP TO 25-30 KTS AS INDICATED BY LOW LEVEL MOMENTUM TRANSPORT NOTED ON FORECAST BUFR SOUNDINGS. EXPECT A RELATIVE LULL IN PRECIP FRI MORNING... A FUNCTION OF RISING HEIGHTS ALOFT OVER THE ERN CAROLINAS AND BRIEF WEAK SUBSIDENCE DOWNSTREAM OF INCREASING PREFRONTAL CONVECTION TO OUR WEST FROM OH THROUGH KY/TN TO MS/LA. BUT WILL HAVE POPS RISING TO LIKELY IN THE NW FRI AFTERNOON AS THE FRONT APPROACHES... AND INTO THE EASTERN CWA FRI EVENING BEFORE TRENDING DRY FROM NW TO SE LATE. BASED ON EXPECTED VERY HIGH PW (OVER 200% OF NORMAL)... STRONG LOW LEVEL MOISTURE TRANSPORT... AND A RESUMPTION OF STRONG UPPER DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A 110+ KT JET STREAK... POPS MAY NEED TO BE BUMPED UP TO CATEGORICAL LATER TODAY. THICKNESSES AND STATISTICAL GUIDANCE INDICATE HIGHS FROM 80-85 (WARMEST SE). LOWS FROM THE LOW 50S NW TO THE LOW 60S SE WHERE THE FRONT MAY NOT CLEAR UNTIL LATE. -GIH && LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 320 PM WEDNESDAY... MERGING SHORTWAVES OVER THE NORTHERN PLAINS WILL SEND A SURFACE LOW ACROSS THE GREAT LAKES ON FRIDAY AND COLD FRONT TOWARD THE APPALACHIANS EARLY FRIDAY. AHEAD OF THE FRONT...FORECAST SOUNDINGS SUGGEST SOUTHWESTERLY WIND GUSTS TO 25-30MPH FRIDAY AFTERNOON...WITH GOOD AGREEMENT AMONG STATISTICAL GUIDANCE FOR HIGHS IN THE UPPER 70S NW TO MID 80S SE. UNLESS DEWPOINTS MIX OUT MORE THAN SOUNDINGS SHOW...MLCAPE IS EXPECTED TO VARY FROM AROUND 500 J/KG WEST TO AS MUCH AS 1000-1500 J/KG EAST. HOWEVER... WITH UNIFORM SOUTHWESTERLY FLOW THERE`S NOT MUCH TO TRIGGER/ENHANCE CONVECTION UNTIL LATER IN THE AFTERNOON IN THE WEST WHEN A PREFRONTAL TROUGH BEGINS TO SHARPEN AHEAD OF THE FRONT. SEVERE POTENTIAL DEPENDS SOMEWHAT ON THE TIMING BUT CURRENTLY LOOKS BEST LATE AFTERNOON IN THE WEST AND EVENING IN THE WEST AS BULK SHEAR INCREASES TO 40-45KT ...THOUGH THE TREND MAY BE TO WEAKEN TO THE EAST OVERNIGHT WITH LOSS OF HEATING. THE FRONT AND ASSOCIATED CONVECTION SHOULD PUSH THROUGH PRETTY QUICKLY FRIDAY NIGHT AND BE EAST OF THE AREA SHORTLY AFTER MIDNIGHT. LOWS IN THE MID 50S TO LOWER 60S. TRANQUIL WEATHER EXPECTED FOR THE WEEKEND AS HIGH PRESSURE SPRAWLS ACROSS THE OH VALLEY AND MID-ATLANTIC STATES. THE ECMWF SHOWS MORE IN THE WAY OF HIGH CLOUDS STREAMING ACROSS THE SOUTHERN US...BUT SKIES HERE SHOULD BE MOSTLY CLEAR. THE GFS IS A TOUCH COOLER THAN THE ECMWF FOR LOWS SUNDAY MORNING AND IS PREFERRED GIVEN 1000-850MB THICKNESSES DROPPING WELL BE 1350M AND PRETTY GOOD RADIATIONAL COOLING CONDITIONS DESPITE THE HIGH STAYING TO OUR NORTH. WILL GO WITH LOWS IN THE MID 40S. THE PATTERN FROM SUNDAY THROUGH THE MIDDLE OF NEXT WEEK LOOKS SOMEWHAT SIMILAR TO THE PATTERN THIS WEEK...WITH AN UPPER LOW OVER THE INNER MOUNTAIN WEST AND A BROAD RIDGE OVER THE EASTERN US. THE MAIN DIFFERENCE MAY BE A LESSER DEGREE OF HEATING AND DIURNAL INSTABILITY THE ECMWF...WHICH HAD BEEN MUCH MORE CONVECTIVELY ACTIVE THAN THE GFS...WAS OVERALL DRIER ON THE 12Z RUN...WHICH IS IN BETTER AGREEMENT WITH THE GFS/CANADIAN AND SEEMS TO FIT THE PATTERN A LITTLE BETTER. WILL ADJUST POPS TO SHOW SLIGHTLY BETTER CHANCES IN THE WEST VERSUS THE EAST....THOUGH KEEPING POPS AT SLIGHT CHANCE MONDAY AND LOW END CHANCE TUESDAY/WEDNESDAY THICKNESSES ARE PROGGED TO BE SLIGHTLY ABOVE NORMAL...20M OR SO...WHICH SUGGESTS AFTERNOON HIGHS IN THE MID 70S TO AROUND 80...A LITTLE WARMER EACH DAY. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 1230 AM THURSDAY... PRIMARY AVIATION CONCERN NEXT 24 HRS: POTENTIAL FOR IFR/LIFR CIGS THROUGH LATE MORNING AT RWI/RDU WITH LESSER CHANCES AT GSO/INT/FAY. A SMALL BUT POTENT STORM COMPLEX THAT MOVED SE OVER NRN AND ERN PORTIONS OF CENTRAL NC THIS PAST EVENING HELPED DRAW A BACKDOOR COLD FRONT SOUTHWESTWARD WELL INTO CENTRAL NC. WINDS BEHIND THE FRONT ARE SHIFTING TO BE FROM THE EAST AND NE... AND LOW CLOUDS BASED UNDER 1000 FT AGL ARE EXPECTED TO SPREAD FROM SOUTH CENTRAL AND SE VA TOWARD THE SOUTH AND SW OVERNIGHT. HIGHEST CONFIDENCE IN IFR/LIFR CIGS IS AT RWI FOLLOWED BY RDU THEN GSO/INT/FAY. A FEW ADDITIONAL SHOWERS AND STORMS ARE POSSIBLE THROUGH DAYBREAK MAINLY OVER THE FAR NORTH AND EAST... FROM GSO TO RDU/RWI/FAY... BUT MOST PLACES WILL REMAIN DRY OVERNIGHT. VSBYS ARE EXPECTED TO DROP TO MVFR BUT AT THIS TIME DON`T LOOK LIKELY TO DROP DOWN TO IFR. CIGS SHOULD RISE TO MVFR BY LATE MORNING THEN TO VFR BY EARLY AFTERNOON... WITH ANOTHER BATCH OF SCATTERED SHOWERS AND STORMS ORIENTED NW TO SE OVER CENTRAL NC DEVELOPING BY MID TO LATE AFTERNOON. UNCERTAINTY REGARDING PRECISELY WHERE THESE STORMS MIGHT FORM AND WHEN... AS WELL AS THE POTENTIAL FOR LOWER-THAN-EXPECTED COVERAGE... PRECLUDES MENTIONING THEM IN THE TAFS AT THIS TIME. BUT AVIATORS SHOULD BE AWARE OF THE POSSIBILITY OF STORMS... AND THE VARIABLE GUSTY WINDS AND SUB-VFR DOWNPOURS THAT OFTEN ACCOMPANY THEM... BOTH IN THE PREDAWN HOURS AND THIS AFTERNOON/EARLY EVENING. PATCHY FOG AND AREAS OF IFR/LIFR STRATUS ARE LIKELY TOWARD THE END OF THE TAF VALID PERIOD PARTICULARLY IN THOSE LOCATIONS THAT SEE PRECIPITATION TODAY. LOOKING BEYOND 06Z EARLY FRI MORNING: SUB-VFR STRATUS AND PATCHY FOG SHOULD PERSIST THROUGH DAYBREAK FRI... BEFORE MIXING UP TO VFR BY MID MORNING. A BREEZE FROM THE SW AT 10-20 KT RAMPING UP TOWARD MIDDAY FRI MAY GUST UP TO AROUND 25 KTS FRI AFTERNOON. THIS WILL OCCUR AHEAD OF A COLD FRONT THAT IS EXPECTED TO PUSH SE THROUGH CENTRAL NC BETWEEN 00Z AND 09Z SAT. WIDESPREAD SHOWERS AND STORMS WITH SUB-VFR CONDITIONS IS LIKELY AHEAD OF THE FRONT FROM MID AFTERNOON FRI THROUGH FRI NIGHT. VFR CONDITIONS ARE LIKELY FROM SAT MORNING THROUGH MON... AS HIGH PRESSURE BUILDS OVER THE MIDATLANTIC REGION OVER THE WEEKEND THEN SHIFTS OFFSHORE BY MON. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...HARTFIELD LONG TERM...22 AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
255 AM EDT THU APR 9 2015 .SYNOPSIS...A BACKDOOR COLD FRONT WILL SETTLE ACROSS NORTH CAROLINA TODAY... AND THEN RETREAT BACK NORTHWARD BY EARLY TONIGHT. BREEZY AND GUSTY SOUTHWEST WINDS FRIDAY WILL BRING INCREASED CHANCES FOR SHOWERS AND STORMS... AHEAD OF A COLD FRONT THAT WILL SWEEP THROUGH THE AREA LATE FRIDAY THROUGH FRIDAY NIGHT. HIGH PRESSURE WILL BUILD IN FOR THE WEEKEND. && .NEAR TERM /TODAY THROUGH TONIGHT/... AS OF 255 AM THURSDAY... SCATTERED SHOWERS AND STORMS CONTINUE TO FORM EARLY THIS MORNING OVER THE WRN AND SRN CWA... ALONG AND SOUTHWEST OF THE BACKDOOR FRONT/MERGED OUTFLOW (FROM LAST EVENING`S SUPERCELL) CURRENTLY SPRAWLED NW TO SE THROUGH CENTRAL NC. THIS CONVECTION IS TRAVELING WITH THE (WEAK) MEAN FLOW TOWARD THE ENE INTO THE MORE STABLE SURFACE-BASED AIR... WHICH SHOULD LIMIT ITS ABILITY TO INTENSIFY OVERNIGHT. BUT ELEVATED INSTABILITY PERSISTS WITH 500-1000 J/KG MUCAPE AND OBSERVED MID LEVEL LAPSE RATES OVER 7 C/KM... AND EFFECTIVE SHEAR HOLDS AT 30-40 KTS ALONG THE CAPE GRADIENT WITH OBSERVED HIGH MOISTURE TRANSPORT IN THE LOW LEVELS AND PW OVER 150% OF NORMAL. THESE FACTORS WILL CONTINUE TO SUPPORT SCATTERED PULSING SHOWERS/STORMS ESPECIALLY ACROSS THE WRN AND SRN CWA... ALONG AND SW OF THE FRONT/OUTFLOW... WITH LESSER COVERAGE TO THE NORTH AND EAST WHERE INSTABILITY IS MORE ELEVATED. HOWEVER... WE WILL NEED TO WATCH THE CONVECTIVE COMPLEX NOW OVER WRN VA TO ENSURE THAT ITS COLD POOL AND MID LEVEL MCV DOES NOT PROPAGATE TOO FAR SE TOWARD OUR NE CWA OVER THE NEXT SEVERAL HOURS... AS WAS INDICATED BY EARLIER HRRR RUNS AND HINTED AT BY THE LATEST NAM. AFTER THIS MCV SHIFTS EASTWARD OFF THE VA COAST AS IT IS EXPECTED TO DO BY MID MORNING... LARGE SCALE FALLING HEIGHTS OVER THE NRN PLAINS INTO THE UPPER MIDWEST THIS MORNING SHOULD FORCE GRADUAL RISES IN HEIGHTS DOWNSTREAM OVER THE MIDATLANTIC AND SOUTHEAST BY LATER TODAY... LEADING TO A SLIGHT DECREASE IN DEEP LAYER SHEAR. BUT WE SHOULD MAINTAIN AT LEAST MODERATE INSTABILITY ALONG AND SOUTHWEST OF THE FRONTAL ZONE... WHICH IS EXPECTED TO MOVE OR JUMP BACK NORTHEAST LATE TODAY OR THIS EVENING... WITH MID LEVEL LAPSE RATES EXPECTED TO HOLD AT 6.5-7.0 C/KM... MUCAPE UP TO 1500-2500 J/KG (ACCORDING TO THE NAM)... AND WHAT SHOULD STILL BE SUFFICIENT EFFECTIVE DEEP LAYER SHEAR TO SUPPORT CONVECTION. THE NAM CONCENTRATES THE BETTER CONVECTION COVERAGE ALONG AND JUST SW OF THE FRONT FROM THE TRIAD REGION ACROSS CENTRAL NC THROUGH THE CENTRAL COASTAL PLAIN TODAY... AND THIS LOOKS VERY REASONABLE. WILL HAVE A 40-60% POP MAINLY FROM LATE MORNING THROUGH THE AFTERNOON WITH THE HIGHER-END POPS ORIENTED IN A BAND NW TO SE FROM AROUND INT TO GSB. A STRONG TO POSSIBLY SEVERE STORM OR TWO REMAINS POSSIBLE TODAY GIVEN THE ANTICIPATED CONVECTIVE PARAMETERS. WHILE WE DON`T EXPECT A WIDESPREAD SEVERE THREAT TODAY WITH THE RISE IN MID LEVEL HEIGHTS... MODELS DO INDICATE AN UPPER DIVERGENCE MAX LATER TODAY OVER CENTRAL NC... AND THIS PLUS HIGH PW VALUES SUGGEST POTENTIAL FOR A FEW STRONG CELLS AND SLOW-MOVING HEAVY RAINERS. BY TONIGHT... WE SHOULD SEE THE HIGHER COVERAGE TRANSITION INTO THE NW CWA... AS THIS IS WHERE THE SHEAR WILL STRENGTHEN AND BECOME MORE SUPPORTIVE OF CONVECTION... WHEREAS SOUTHEAST SECTIONS WILL BE MORE UNDER THE INFLUENCE OF THE BUILDING RIDGE ALONG THE SOUTHEAST COAST WITH WEAKER SHEAR. THE SLIGHTLY DRIER AIR NOW NOTED IN BLENDED TPW IMAGERY NORTH AND NE OF THE BAHAMAS WILL BE DRAWN NORTHWARD INTO ERN NC AS WELL... LIKELY LEADING TO LOWER COVERAGE OF SHOWERS AND ISOLATED STORMS SE OF THE TRIANGLE AS WE HEAD INTO TONIGHT. EXPECT HIGHS OF 80-85 OVER THE SW HALF WITH COOLER MID-UPPER 70S NE OF THE FRONT WHERE LOW CLOUDS WILL LINGER THE LONGEST BEFORE STARTING TO THIN AND MIX OUT. WARM LOWS TONIGHT MAINLY IN THE MID 60S AS WE`LL BE FULLY IN THE PREFRONTAL WARM SECTOR. -GIH && .SHORT TERM /THURSDAY AND THURSDAY NIGHT/... AS OF 300 PM WEDNESDAY... TO BE UPDATED SHORTLY. && LONG TERM /FRIDAY THROUGH WEDNESDAY/... AS OF 320 PM WEDNESDAY... MERGING SHORTWAVES OVER THE NORTHERN PLAINS WILL SEND A SURFACE LOW ACROSS THE GREAT LAKES ON FRIDAY AND COLD FRONT TOWARD THE APPALACHIANS EARLY FRIDAY. AHEAD OF THE FRONT...FORECAST SOUNDINGS SUGGEST SOUTHWESTERLY WIND GUSTS TO 25-30MPH FRIDAY AFTERNOON...WITH GOOD AGREEMENT AMONG STATISTICAL GUIDANCE FOR HIGHS IN THE UPPER 70S NW TO MID 80S SE. UNLESS DEWPOINTS MIX OUT MORE THAN SOUNDINGS SHOW...MLCAPE IS EXPECTED TO VARY FROM AROUND 500 J/KG WEST TO AS MUCH AS 1000-1500 J/KG EAST. HOWEVER... WITH UNIFORM SOUTHWESTERLY FLOW THERE`S NOT MUCH TO TRIGGER/ENHANCE CONVECTION UNTIL LATER IN THE AFTERNOON IN THE WEST WHEN A PREFRONTAL TROUGH BEGINS TO SHARPEN AHEAD OF THE FRONT. SEVERE POTENTIAL DEPENDS SOMEWHAT ON THE TIMING BUT CURRENTLY LOOKS BEST LATE AFTERNOON IN THE WEST AND EVENING IN THE WEST AS BULK SHEAR INCREASES TO 40-45KT ...THOUGH THE TREND MAY BE TO WEAKEN TO THE EAST OVERNIGHT WITH LOSS OF HEATING. THE FRONT AND ASSOCIATED CONVECTION SHOULD PUSH THROUGH PRETTY QUICKLY FRIDAY NIGHT AND BE EAST OF THE AREA SHORTLY AFTER MIDNIGHT. LOWS IN THE MID 50S TO LOWER 60S. TRANQUIL WEATHER EXPECTED FOR THE WEEKEND AS HIGH PRESSURE SPRAWLS ACROSS THE OH VALLEY AND MID-ATLANTIC STATES. THE ECMWF SHOWS MORE IN THE WAY OF HIGH CLOUDS STREAMING ACROSS THE SOUTHERN US...BUT SKIES HERE SHOULD BE MOSTLY CLEAR. THE GFS IS A TOUCH COOLER THAN THE ECMWF FOR LOWS SUNDAY MORNING AND IS PREFERRED GIVEN 1000-850MB THICKNESSES DROPPING WELL BE 1350M AND PRETTY GOOD RADIATIONAL COOLING CONDITIONS DESPITE THE HIGH STAYING TO OUR NORTH. WILL GO WITH LOWS IN THE MID 40S. THE PATTERN FROM SUNDAY THROUGH THE MIDDLE OF NEXT WEEK LOOKS SOMEWHAT SIMILAR TO THE PATTERN THIS WEEK...WITH AN UPPER LOW OVER THE INNER MOUNTAIN WEST AND A BROAD RIDGE OVER THE EASTERN US. THE MAIN DIFFERENCE MAY BE A LESSER DEGREE OF HEATING AND DIURNAL INSTABILITY THE ECMWF...WHICH HAD BEEN MUCH MORE CONVECTIVELY ACTIVE THAN THE GFS...WAS OVERALL DRIER ON THE 12Z RUN...WHICH IS IN BETTER AGREEMENT WITH THE GFS/CANADIAN AND SEEMS TO FIT THE PATTERN A LITTLE BETTER. WILL ADJUST POPS TO SHOW SLIGHTLY BETTER CHANCES IN THE WEST VERSUS THE EAST....THOUGH KEEPING POPS AT SLIGHT CHANCE MONDAY AND LOW END CHANCE TUESDAY/WEDNESDAY THICKNESSES ARE PROGGED TO BE SLIGHTLY ABOVE NORMAL...20M OR SO...WHICH SUGGESTS AFTERNOON HIGHS IN THE MID 70S TO AROUND 80...A LITTLE WARMER EACH DAY. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 1230 AM THURSDAY... PRIMARY AVIATION CONCERN NEXT 24 HRS: POTENTIAL FOR IFR/LIFR CIGS THROUGH LATE MORNING AT RWI/RDU WITH LESSER CHANCES AT GSO/INT/FAY. A SMALL BUT POTENT STORM COMPLEX THAT MOVED SE OVER NRN AND ERN PORTIONS OF CENTRAL NC THIS PAST EVENING HELPED DRAW A BACKDOOR COLD FRONT SOUTHWESTWARD WELL INTO CENTRAL NC. WINDS BEHIND THE FRONT ARE SHIFTING TO BE FROM THE EAST AND NE... AND LOW CLOUDS BASED UNDER 1000 FT AGL ARE EXPECTED TO SPREAD FROM SOUTH CENTRAL AND SE VA TOWARD THE SOUTH AND SW OVERNIGHT. HIGHEST CONFIDENCE IN IFR/LIFR CIGS IS AT RWI FOLLOWED BY RDU THEN GSO/INT/FAY. A FEW ADDITIONAL SHOWERS AND STORMS ARE POSSIBLE THROUGH DAYBREAK MAINLY OVER THE FAR NORTH AND EAST... FROM GSO TO RDU/RWI/FAY... BUT MOST PLACES WILL REMAIN DRY OVERNIGHT. VSBYS ARE EXPECTED TO DROP TO MVFR BUT AT THIS TIME DON`T LOOK LIKELY TO DROP DOWN TO IFR. CIGS SHOULD RISE TO MVFR BY LATE MORNING THEN TO VFR BY EARLY AFTERNOON... WITH ANOTHER BATCH OF SCATTERED SHOWERS AND STORMS ORIENTED NW TO SE OVER CENTRAL NC DEVELOPING BY MID TO LATE AFTERNOON. UNCERTAINTY REGARDING PRECISELY WHERE THESE STORMS MIGHT FORM AND WHEN... AS WELL AS THE POTENTIAL FOR LOWER-THAN-EXPECTED COVERAGE... PRECLUDES MENTIONING THEM IN THE TAFS AT THIS TIME. BUT AVIATORS SHOULD BE AWARE OF THE POSSIBILITY OF STORMS... AND THE VARIABLE GUSTY WINDS AND SUB-VFR DOWNPOURS THAT OFTEN ACCOMPANY THEM... BOTH IN THE PREDAWN HOURS AND THIS AFTERNOON/EARLY EVENING. PATCHY FOG AND AREAS OF IFR/LIFR STRATUS ARE LIKELY TOWARD THE END OF THE TAF VALID PERIOD PARTICULARLY IN THOSE LOCATIONS THAT SEE PRECIPITATION TODAY. LOOKING BEYOND 06Z EARLY FRI MORNING: SUB-VFR STRATUS AND PATCHY FOG SHOULD PERSIST THROUGH DAYBREAK FRI... BEFORE MIXING UP TO VFR BY MID MORNING. A BREEZE FROM THE SW AT 10-20 KT RAMPING UP TOWARD MIDDAY FRI MAY GUST UP TO AROUND 25 KTS FRI AFTERNOON. THIS WILL OCCUR AHEAD OF A COLD FRONT THAT IS EXPECTED TO PUSH SE THROUGH CENTRAL NC BETWEEN 00Z AND 09Z SAT. WIDESPREAD SHOWERS AND STORMS WITH SUB-VFR CONDITIONS IS LIKELY AHEAD OF THE FRONT FROM MID AFTERNOON FRI THROUGH FRI NIGHT. VFR CONDITIONS ARE LIKELY FROM SAT MORNING THROUGH MON... AS HIGH PRESSURE BUILDS OVER THE MIDATLANTIC REGION OVER THE WEEKEND THEN SHIFTS OFFSHORE BY MON. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM... LONG TERM...22 AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
323 PM CDT THU APR 9 2015 .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 323 PM CDT THU APR 9 2015 FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE ISOLATED SHOWERS AND GUSTY WINDS THROUGH EARLY THIS EVENING. OTHERWISE A QUIET TONIGHT AND FRIDAY. CURRENTLY...NORTHERLY FLOW ALOFT WITH A WEAK RIDGE ACROSS THE NORTHERN ROCKIES AND A STRONG S/WV MOVING SOUTH TOWARDS NORTHERN MINNESOTA. LARGE CU FIELD DEVELOPING AS EXPECTED THIS AFTERNOON AHEAD OF AN INVERTED SFC TROUGH/FRONTAL BOUNDARY NOW PUSHING SOUTH ACROSS NORTHERN NORTH DAKOTA. A FEW SHOWERS POPPING UP WITHIN THE CU AS THE HRRR AND 4KM WRF ADVERTISED. DOUBTFUL MUCH WILL REACH THE GROUND BUT WILL MAINTAIN SHOWERS IN THE FORECAST NOW THROUGH 03Z. WINDS GUSTING TO AROUND 30KTS AS WE MIX TO AROUND 700MB AND SHOULD CONTINUE UNTIL AROUND SUNDOWN...THEN DISSIPATE QUICKLY. WINDS WILL BE ENHANCED BY THE SHOWER ACTIVITY...AIDED WITH EVAPORATIONAL COOLING BENEATH THE CLOUD BASES AS PRECIPITATION FALLS. SURFACE HIGH PRESSURE BUILDS INTO THE NORTHERN PLAINS TONIGHT CLEARING THE SKY. HIGH PRESSURE CONTINUES SOUTH AND EAST FRIDAY ALLOWING FOR RETURN FLOW/WAA INTO THE REGION. DECENT DAY FRIDAY WITH HIGHS IN THE 50S AND A RELATIVELY LIGHT WIND AND MOSTLY SUNNY SKY. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 323 PM CDT THU APR 9 2015 THE MAIN FORECAST ISSUES IN THE LONG TERM INCLUDE STRONG AND GUSTY NORTHWEST WINDS SUNDAY - WITH POTENTIAL FIRE WEATHER ISSUES - AND AN UPPER LEVEL LOW/TROUGH SETTING UP FOR NEXT WEDNESDAY/THURSDAY. FRIDAY NIGHT AND SATURDAY: HIGH PRESSURE EXITS THE AREA TO THE EAST AS LOW PRESSURE DEVELOPS IN THE LEE OF THE ROCKIES AND APPROACHES NORTH DAKOTA. BY SATURDAY AFTERNOON AN UPPER LEVEL TROUGH EXPANDS EASTWARD AND SOUTHWEST FLOW ALOFT IS ESTABLISHED OVER THE NORTHERN PLAINS. MEANWHILE A SURFACE WARM FRONT IS EXPECTED TO ENTER WESTERN NORTH DAKOTA...WITH HIGHS REACHING THE UPPER 60S AND LOWER 70S. SATURDAY NIGHT: UPPER LEVEL ENERGY REACHES NORTH DAKOTA AHEAD OF AND ALONG AN ASSOCIATED COLD FRONT. CHANCE OF SHOWERS...MAINLY NORTH AND WEST. SUNDAY: THE COLD FRONT PUSHES SOUTHEAST ACROSS THE STATE EARLY SUNDAY MORNING...WITH STRONG NORTHWEST WINDS OF 20 TO 35 MPH WITH GUSTS TO 40 MPH POSSIBLE. SEE THE FIRE WEATHER DISCUSSION BELOW FOR FIRE WEATHER CONCERNS. MONDAY AND TUESDAY SHOULD BE DRY WITH HIGHS IN THE 60S MONDAY...AND 65 TO 75 TUESDAY. THE NEXT UPPER LEVEL TROUGH MOVES ACROSS THE ROCKIES AND EMERGES IN THE WESTERN PLAINS TUESDAY NIGHT...CROSSING THE PLAINS WEDNESDAY AND THURSDAY. CHANCES OF RAIN SHOWERS INCREASE DURING THIS TIME...WITH HIGHS 50 TO 60 WEDNESDAY...AND UPPER 40S TO LOWER 50S THURSDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 323 PM CDT THU APR 9 2015 VFR CONDITIONS ALL TERMINALS THROUGH THE 18Z TAF PERIOD. LARGE BUT SHALLOW CUMULUS CANOPY ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON ALONG WITH ISOLATED LIGHT RAIN SHOWER ACTIVITY. GUSTY NORTHWEST WINDS SUSTAINED NEAR 20KTS AND GUSTS TO 30 KTS WILL BE COMMON THIS AFTERNOON THROUGH EARLY EVENING. WINDS WILL DIMINISH AROUND AND AFTER SUNSET...WITH THE CUMULUS DISSIPATING AS WELL WITH SKC TO FOLLOW TONIGHT. WILL INCLUDE A VCSH FOR KDIK-KBIS-KJMS WHERE IT APPEARS THE CU FIELD LINGER THE LONGEST THIS AFTERNOON. && .FIRE WEATHER... ISSUED AT 323 PM CDT THU APR 9 2015 SUNDAY: STRONG NORTHWEST WINDS OF 20 TO 35 MPH WITH GUSTS TO 40 MPH POSSIBLE. HIGHS OF 55 TO 60 EXPECTED...WITH MINIMUM RELATIVE HUMIDITY VALUES AROUND 20 PERCENT SOUTHWEST TO AROUND 25 PERCENT NORTHWEST AND CENTRAL. WILL CONTINUE TO MONITOR FOR POSSIBLE FIRE WEATHER WATCH. RECENT RAIN AND SNOWFALL OVER THE REGION IS NOTED...AND WEATHER DORMANT GRASSES WILL HAVE TIME TO DRY OUT IS THE MAIN QUESTION. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...JV LONG TERM...NH AVIATION...NH FIRE WEATHER...JV
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1226 PM CDT THU APR 9 2015 .UPDATE... ISSUED AT 1226 PM CDT THU APR 9 2015 FORECAST ON TRACK...NO CHANGES FROM PREVIOUS FORECAST ISSUANCE. CU FIELD DEVELOPMENT UNDERWAY...AND SHOULD CONTINUE OVER THE NEXT FEW HOURS. UPDATE ISSUED AT 1022 AM CDT THU APR 9 2015 LAST FEW RUNS OF THE HRRR ALONG WITH THE 4KM WRF ALL INDICATE ISOLATED SHOWERS DEVELOPING THIS AFTERNOON SO HAVE ADDED THIS INTO THE FORECAST. KEPT QPF AT ZERO AS ONLY EXPECTED TRACE AMOUNTS OF MOISTURE. OTHERWISE THE INHERITED FORECAST IN GOOD SHAPE. CU FIELD SHOULD DEVELOP BY EARLY TO MID AFTERNOON ALONG TO AHEAD OF A SFC COLD FRONT MOVING SOUTH THROUGH NORTH DAKOTA TODAY. WINDS STILL LOOK BREEZY...ESPECIALLY MID TO LATE DAY WHEN WE ARE PROJECTED TO MIX OUT TO AROUND 700MB. ANY SHOWER ACTIVITY WILL AID IN GUSTY WINDS WITH EVAPORATIONAL COOLING BENEATH THE CLOUD BASES. UPDATE ISSUED AT 630 AM CDT THU APR 9 2015 PRECIPITATION IS MOVING OUT OF THE FAR SOUTHEAST CWA. HAVE A SLIGHT CHANCE FOR A COUPLE MORE HOUR OVER MAINLY DICKEY COUNTY. OTHERWISE DRY ELSEWHERE FOR THIS MORNING. COULD BE A FEW SHOWERS THIS AFTERNOON...SEE DISCUSSION BELOW...BUT FOR NOW WILL KEEP IT DRY. MADE SOME MINOR UPDATES TO SKY COVER BASED ON LATEST SATELLITE IMAGERY. OTHERWISE NO SIGNIFICANT CHANGES THIS MORNING. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 355 AM CDT THU APR 9 2015 HIGHLIGHTS IN THE SHORT TERM IS A TRANSITION FROM SOUTHWEST FLOW ALOFT EARLY THIS MORNING TO A MORE NORTHERLY FLOW LATER TODAY THROUGH THURSDAY NIGHT. A FEW POPCORN TYPE SHOWERS COULD DEVELOP AHEAD OF AN ADVANCING SHORTWAVE TROUGH AND SURFACE COLD FRONT THIS AFTERNOON ACROSS PORTIONS OF WESTERN AND NORTH CENTRAL NORTH DAKOTA. THE LATEST HRRR CEILING FORECAST SHOWS A FAIRLY LARGE CUMULUS FIELD DEVELOPING AFTER 18Z THROUGH 00Z. HOWEVER THE DEPTH OF THE CUMULUS FIELD PER BUFKIT SOUNDINGS LOOKS SHALLOW TO SUPPORT MUCH PRECIPITATION ACTIVITY. THE NET EFFECT MAY ACTUALLY INCREASE WIND GUSTS BRIEFLY WITH ANY EVAPORATIONAL COOLING BENEATH THE CLOUD BASE. BUFKIT SOUNDINGS SHOW A WELL ESTABLISHED MIXED LAYER TODAY...WHEREAS THE PREVIOUS SHIFTS HAD THIS WELL COVERED. THUS EXPECT BREEZY/WINDY CONDITIONS WITH WINDS 20 TO 30 MPH THIS AFTERNOON. IN TERMS OF POPS TODAY...FOR NOW HAVE INCREASED THEM TO 14 FOR THE WEST AND NORTH CENTRAL AND WILL LET THE DAY SHIFT RE-EVALUATE THE MORNING DATA AS TO WHETHER OR NOT TO ADD A FEW POPCORN SHOWERS THIS AFTERNOON. FOR THE NEAR TERM...THROUGH 12Z-15Z THURSDAY...PRECIPITATION CONTINUES TO WANE OVER THE SOUTHEAST AS THE UPPER LOW ACROSS SOUTHEAST WYOMING IS SHIFTING THE BEST LIFT FARTHER EAST. CURRENT FOG/STRATUS LOOP CONTINUES TO SHOW PATCHY FOG/LOW CLOUDS ACROSS THE SOUTHWEST AND SOUTH CENTRAL. THIS WILL SLOWLY SHIFT EAST THROUGH THE EARLY MORNING. THE LATEST WATER VAPOR IMAGERY LOOP SHOWS THE SOUTHERN BRANCH UPPER FLOW INTO CENTRAL NORTH DAKOTA IS SLOWLY WEAKENING...AS A NORTHERN STREAM SHORTWAVE IS PUSHING THROUGH NORTHWEST NORTH DAKOTA EARLY THIS MORNING. THIS WILL PUSH THE INFLUX OF MOISTURE FARTHER EAST WITH THE EROSION OF STRATUS ACROSS THE SOUTH THROUGH MID MORNING. ANOTHER SHORTWAVE SEEN NEAR THE NORTHEAST BORDER OF SASKATCHEWAN/MANITOBA...WILL SHIFT INTO LAKE MANITOBA BY 18Z THURSDAY AND THEN DIVE SOUTH INTO FAR EASTERN NORTH DAKOTA BY 12Z FRIDAY. A SURFACE COLD FRONT IS ASSOCIATED WITH THIS SHORTWAVE. EXPECT LOW LEVEL WARMING TODAY AHEAD OF IT WITH H85 TEMPS RISING TO BETWEEN +2C AND +4C ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE COLD FRONT WILL MAKE IT INTO NORTH CENTRAL NORTH DAKOTA BETWEEN 18Z AND 21Z. AFTERNOON HIGH TEMPERATURES WILL REACH INTO THE 50S ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE NAM/ECMWF AGREE WITH SOME POTENTIAL OF A SHOWER OR TWO IN NORTH CENTRAL NORTH DAKOTA THIS AFTERNOON. THE HI RESOLUTION ARW WEST AND NMM WEST ALSO SHOW A FEW LIGHT MEASURABLE QPF STRIATIONS DEVELOPING ACROSS THE WEST AND SOUTHWEST. UNCERTAINTY REMAINS WITH ANY DEVELOPMENT AND LOCATION AT THIS TIME...THUS WILL KEEP THINGS DRY AND MONITOR THE DATA LATER THIS MORNING INTO THE AFTERNOON. THE COLD FRONT WILL SLIDE FROM NORTH TO SOUTH THROUGH THURSDAY EVENING FOLLOWED BY A CLEARING SKY AROUND SUNSET...AS ANY CUMULUS WILL COLLAPSE AND DISSIPATE QUICKLY. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 355 AM CDT THU APR 9 2015 THE MAIN FORECAST ISSUES IN THE LONG TERM PERIOD ARE LATE IN THE PERIOD ASSOCIATED WITH AN UPPER LEVEL LOW TRACKING FROM THE WESTERN U.S. INTO THE PLAINS. BEFORE THAT...RATHER QUIET BUT WITH A FEW POSSIBLE FIRE WEATHER ISSUES. DETERMINISTIC MODELS ARE IN A LITTLE BETTER AGREEMENT WITH THE LATE PERIOD SYSTEM. IN GENERAL ECMWF HAS COME INTO BETTER AGREEMENT WITH THE GFS. ENSEMBLE SPREAD HAS ALSO NARROWED SOME...BUT GFSENSEMBLE IS STILL GIVING A RATHER LARGE ENVELOPE OF SOLUTIONS WITH THE PLACEMENT OF THE MID-UPPER LEVEL LOW AT 12 UTC THURSDAY. THUS WILL STICK CLOSE TO THE MODEL BLEND SOLUTION. FRIDAY SHOULD BE A NICE DAY...BUT DID DROP TEMPERATURES JUST A BIT FROM THE PREVIOUS FORECAST. A WAVE DROPPING DOWN THE BUILDING UPPER RIDGE DROPS ALMOST DUE SOUTH ACROSS MINNESOTA DRAGGING SOME COOLER AIR SOUTH INTO THE FORECAST AREA. HIGHS STILL MAINLY IN THE 50S. WE WARM NICELY ON SATURDAY AS SURFACE HIGH PRESSURE AND UPPER LEVEL RIDGING MOVE EAST AND SOUTHERLY RETURN FLOW KICKS IN. WE DO SEE RELATIVE HUMIDITIES DROP INTO THE LOW TO MID 20S SOUTH AND WEST OF LAKE SAKAKAWEA AND THE MISSOURI RIVER. HOWEVER...WINDS AT THE TOP OF THE MIXING LAYER ARE GENERALLY 15 TO 20 KNOTS. SOMETHING TO KEEP AN EYE ON...BUT FIRE WEATHER HAZARDS ARE NOT ANTICIPATED AT THIS TIME. A COLD FRONT MOVE THROUGH THE AREA SATURDAY NIGHT. MOISTURE IS LIMITED AHEAD OF THE FRONT AND ONLY INCREASES IN THE MID AND UPPER LEVELS BEHIND THE FRONT. DO EXPECT SOME GUSTY WINDS WITH THE FRONTAL PASSAGE...WITH POSSIBLY SOME ISOLATED SHOWERS REACHING THE GROUND BEHIND THE SURFACE COLD FRONT LATE SATURDAY NIGHT INTO EARLY SUNDAY MORNING ASSOCIATED WITH THE PASSAGE OF THE MID LEVEL SHORTWAVE TROUGH. IT WILL REMAIN WINDY THROUGHOUT THE DAY SUNDAY WITH TEMPERATURES AROUND 10 DEGREES COLDER THAN SATURDAY. WE STILL SEE SOME LOWER 20 PERCENT RELATIVE HUMIDITIES SUNDAY AFTERNOON OVER THE SOUTHWEST. THESE HUMIDITIES...COMBINED WITH THE STRONG WINDS WILL RESULT IN HIGHER FIRE WEATHER CONCERNS. THE COOLER TEMPERATURES SUNDAY AND RECENT MOISTURE WILL BE LIMITING FACTORS...BUT WITH STRONG WINDS AND NEAR 20 PERCENT HUMIDITIES...WILL CERTAINLY NEED TO MONITOR. LOOKS LIKE A COUPLE OF DRY DAYS MONDAY AND TUESDAY AHEAD OF THE APPROACHING UPPER LEVEL TROUGH. THE ECMWF DOES SHOW SOME LIGHT SHOWERS OVER THE AREA TUESDAY...BUT HAS BACKED OFF SIGNIFICANTLY ON THE COLD WET TUESDAY SOLUTION OF 24 HOURS AGO...AND IS MORE IN LINE WITH THE WARMER AND DRIER GFS. HOWEVER...BEYOND TUESDAY THERE REMAINS MUCH UNCERTAINTY IN THE EVOLUTION OF THE UPPER LEVEL SYSTEM AS IT TRANSLATES THROUGH THE ROCKIES AND ONTO THE PLAINS. THUS WILL UTILIZE THE MODEL BLEND SOLUTION FOR POPS. IT LOOKS TO BE MILD MONDAY AND TUESDAY AHEAD OF THE SYSTEM WITH HIGHS IN THE 60S TO 70S. TEMPERATURES WILL THEN COOL BACK TO NEAR NORMAL WEDNESDAY. THURSDAY AND THURSDAY NIGHT ARE LOOKING TO BE COOL AND WET...BUT HOW COOL AND HOW WET ARE YET TO BE DETERMINED. DEFINITELY AN UNSETTLED PATTERN IN STORE MID TO LATE WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1226 PM CDT THU APR 9 2015 ALL TERMINALS WILL REMAIN VFR TODAY AND TONIGHT. A FAIRLY LARGE BUT SHALLOW CUMULUS CANOPY WILL FORM ACROSS WESTERN AND CENTRAL NORTH DAKOTA BETWEEN 18Z THURSDAY THROUGH 00Z FRIDAY. GUSTY NORTHWEST WINDS OF 15KT TO 25 KT WILL ALSO BE COMMON THIS AFTERNOON. WINDS WILL DIMINISH TOWARD SUNSET...WITH THE CUMULUS DISSIPATING AS WELL WITH SKC TO FOLLOW THURSDAY NIGHT. WILL INCLUDE A VCSH FOR SOME TERMINALS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...NH SHORT TERM...KS LONG TERM...TWH AVIATION...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1022 AM CDT THU APR 9 2015 .UPDATE... ISSUED AT 1022 AM CDT THU APR 9 2015 LAST FEW RUNS OF THE HRRR ALONG WITH THE 4KM WRF ALL INDICATE ISOLATED SHOWERS DEVELOPING THIS AFTERNOON SO HAVE ADDED THIS INTO THE FORECAST. KEPT QPF AT ZERO AS ONLY EXPECTED TRACE AMOUNTS OF MOISTURE. OTHERWISE THE INHERITED FORECAST IN GOOD SHAPE. CU FIELD SHOULD DEVELOP BY EARLY TO MID AFTERNOON ALONG TO AHEAD OF A SFC COLD FRONT MOVING SOUTH THROUGH NORTH DAKOTA TODAY. WINDS STILL LOOK BREEZY...ESPECIALLY MID TO LATE DAY WHEN WE ARE PROJECTED TO MIX OUT TO AROUND 700MB. ANY SHOWER ACTIVITY WILL AID IN GUSTY WINDS WITH EVAPORATIONAL COOLING BENEATH THE CLOUD BASES. UPDATE ISSUED AT 630 AM CDT THU APR 9 2015 PRECIPITATION IS MOVING OUT OF THE FAR SOUTHEAST CWA. HAVE A SLIGHT CHANCE FOR A COUPLE MORE HOUR OVER MAINLY DICKEY COUNTY. OTHERWISE DRY ELSEWHERE FOR THIS MORNING. COULD BE A FEW SHOWERS THIS AFTERNOON...SEE DISCUSSION BELOW...BUT FOR NOW WILL KEEP IT DRY. MADE SOME MINOR UPDATES TO SKY COVER BASED ON LATEST SATELLITE IMAGERY. OTHERWISE NO SIGNIFICANT CHANGES THIS MORNING. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 355 AM CDT THU APR 9 2015 HIGHLIGHTS IN THE SHORT TERM IS A TRANSITION FROM SOUTHWEST FLOW ALOFT EARLY THIS MORNING TO A MORE NORTHERLY FLOW LATER TODAY THROUGH THURSDAY NIGHT. A FEW POPCORN TYPE SHOWERS COULD DEVELOP AHEAD OF AN ADVANCING SHORTWAVE TROUGH AND SURFACE COLD FRONT THIS AFTERNOON ACROSS PORTIONS OF WESTERN AND NORTH CENTRAL NORTH DAKOTA. THE LATEST HRRR CEILING FORECAST SHOWS A FAIRLY LARGE CUMULUS FIELD DEVELOPING AFTER 18Z THROUGH 00Z. HOWEVER THE DEPTH OF THE CUMULUS FIELD PER BUFKIT SOUNDINGS LOOKS SHALLOW TO SUPPORT MUCH PRECIPITATION ACTIVITY. THE NET EFFECT MAY ACTUALLY INCREASE WIND GUSTS BRIEFLY WITH ANY EVAPORATIONAL COOLING BENEATH THE CLOUD BASE. BUFKIT SOUNDINGS SHOW A WELL ESTABLISHED MIXED LAYER TODAY...WHEREAS THE PREVIOUS SHIFTS HAD THIS WELL COVERED. THUS EXPECT BREEZY/WINDY CONDITIONS WITH WINDS 20 TO 30 MPH THIS AFTERNOON. IN TERMS OF POPS TODAY...FOR NOW HAVE INCREASED THEM TO 14 FOR THE WEST AND NORTH CENTRAL AND WILL LET THE DAY SHIFT RE-EVALUATE THE MORNING DATA AS TO WHETHER OR NOT TO ADD A FEW POPCORN SHOWERS THIS AFTERNOON. FOR THE NEAR TERM...THROUGH 12Z-15Z THURSDAY...PRECIPITATION CONTINUES TO WANE OVER THE SOUTHEAST AS THE UPPER LOW ACROSS SOUTHEAST WYOMING IS SHIFTING THE BEST LIFT FARTHER EAST. CURRENT FOG/STRATUS LOOP CONTINUES TO SHOW PATCHY FOG/LOW CLOUDS ACROSS THE SOUTHWEST AND SOUTH CENTRAL. THIS WILL SLOWLY SHIFT EAST THROUGH THE EARLY MORNING. THE LATEST WATER VAPOR IMAGERY LOOP SHOWS THE SOUTHERN BRANCH UPPER FLOW INTO CENTRAL NORTH DAKOTA IS SLOWLY WEAKENING...AS A NORTHERN STREAM SHORTWAVE IS PUSHING THROUGH NORTHWEST NORTH DAKOTA EARLY THIS MORNING. THIS WILL PUSH THE INFLUX OF MOISTURE FARTHER EAST WITH THE EROSION OF STRATUS ACROSS THE SOUTH THROUGH MID MORNING. ANOTHER SHORTWAVE SEEN NEAR THE NORTHEAST BORDER OF SASKATCHEWAN/MANITOBA...WILL SHIFT INTO LAKE MANITOBA BY 18Z THURSDAY AND THEN DIVE SOUTH INTO FAR EASTERN NORTH DAKOTA BY 12Z FRIDAY. A SURFACE COLD FRONT IS ASSOCIATED WITH THIS SHORTWAVE. EXPECT LOW LEVEL WARMING TODAY AHEAD OF IT WITH H85 TEMPS RISING TO BETWEEN +2C AND +4C ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE COLD FRONT WILL MAKE IT INTO NORTH CENTRAL NORTH DAKOTA BETWEEN 18Z AND 21Z. AFTERNOON HIGH TEMPERATURES WILL REACH INTO THE 50S ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE NAM/ECMWF AGREE WITH SOME POTENTIAL OF A SHOWER OR TWO IN NORTH CENTRAL NORTH DAKOTA THIS AFTERNOON. THE HI RESOLUTION ARW WEST AND NMM WEST ALSO SHOW A FEW LIGHT MEASURABLE QPF STRIATIONS DEVELOPING ACROSS THE WEST AND SOUTHWEST. UNCERTAINTY REMAINS WITH ANY DEVELOPMENT AND LOCATION AT THIS TIME...THUS WILL KEEP THINGS DRY AND MONITOR THE DATA LATER THIS MORNING INTO THE AFTERNOON. THE COLD FRONT WILL SLIDE FROM NORTH TO SOUTH THROUGH THURSDAY EVENING FOLLOWED BY A CLEARING SKY AROUND SUNSET...AS ANY CUMULUS WILL COLLAPSE AND DISSIPATE QUICKLY. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 355 AM CDT THU APR 9 2015 THE MAIN FORECAST ISSUES IN THE LONG TERM PERIOD ARE LATE IN THE PERIOD ASSOCIATED WITH AN UPPER LEVEL LOW TRACKING FROM THE WESTERN U.S. INTO THE PLAINS. BEFORE THAT...RATHER QUIET BUT WITH A FEW POSSIBLE FIRE WEATHER ISSUES. DETERMINISTIC MODELS ARE IN A LITTLE BETTER AGREEMENT WITH THE LATE PERIOD SYSTEM. IN GENERAL ECMWF HAS COME INTO BETTER AGREEMENT WITH THE GFS. ENSEMBLE SPREAD HAS ALSO NARROWED SOME...BUT GFSENSEMBLE IS STILL GIVING A RATHER LARGE ENVELOPE OF SOLUTIONS WITH THE PLACEMENT OF THE MID-UPPER LEVEL LOW AT 12 UTC THURSDAY. THUS WILL STICK CLOSE TO THE MODEL BLEND SOLUTION. FRIDAY SHOULD BE A NICE DAY...BUT DID DROP TEMPERATURES JUST A BIT FROM THE PREVIOUS FORECAST. A WAVE DROPPING DOWN THE BUILDING UPPER RIDGE DROPS ALMOST DUE SOUTH ACROSS MINNESOTA DRAGGING SOME COOLER AIR SOUTH INTO THE FORECAST AREA. HIGHS STILL MAINLY IN THE 50S. WE WARM NICELY ON SATURDAY AS SURFACE HIGH PRESSURE AND UPPER LEVEL RIDGING MOVE EAST AND SOUTHERLY RETURN FLOW KICKS IN. WE DO SEE RELATIVE HUMIDITIES DROP INTO THE LOW TO MID 20S SOUTH AND WEST OF LAKE SAKAKAWEA AND THE MISSOURI RIVER. HOWEVER...WINDS AT THE TOP OF THE MIXING LAYER ARE GENERALLY 15 TO 20 KNOTS. SOMETHING TO KEEP AN EYE ON...BUT FIRE WEATHER HAZARDS ARE NOT ANTICIPATED AT THIS TIME. A COLD FRONT MOVE THROUGH THE AREA SATURDAY NIGHT. MOISTURE IS LIMITED AHEAD OF THE FRONT AND ONLY INCREASES IN THE MID AND UPPER LEVELS BEHIND THE FRONT. DO EXPECT SOME GUSTY WINDS WITH THE FRONTAL PASSAGE...WITH POSSIBLY SOME ISOLATED SHOWERS REACHING THE GROUND BEHIND THE SURFACE COLD FRONT LATE SATURDAY NIGHT INTO EARLY SUNDAY MORNING ASSOCIATED WITH THE PASSAGE OF THE MID LEVEL SHORTWAVE TROUGH. IT WILL REMAIN WINDY THROUGHOUT THE DAY SUNDAY WITH TEMPERATURES AROUND 10 DEGREES COLDER THAN SATURDAY. WE STILL SEE SOME LOWER 20 PERCENT RELATIVE HUMIDITIES SUNDAY AFTERNOON OVER THE SOUTHWEST. THESE HUMIDITIES...COMBINED WITH THE STRONG WINDS WILL RESULT IN HIGHER FIRE WEATHER CONCERNS. THE COOLER TEMPERATURES SUNDAY AND RECENT MOISTURE WILL BE LIMITING FACTORS...BUT WITH STRONG WINDS AND NEAR 20 PERCENT HUMIDITIES...WILL CERTAINLY NEED TO MONITOR. LOOKS LIKE A COUPLE OF DRY DAYS MONDAY AND TUESDAY AHEAD OF THE APPROACHING UPPER LEVEL TROUGH. THE ECMWF DOES SHOW SOME LIGHT SHOWERS OVER THE AREA TUESDAY...BUT HAS BACKED OFF SIGNIFICANTLY ON THE COLD WET TUESDAY SOLUTION OF 24 HOURS AGO...AND IS MORE IN LINE WITH THE WARMER AND DRIER GFS. HOWEVER...BEYOND TUESDAY THERE REMAINS MUCH UNCERTAINTY IN THE EVOLUTION OF THE UPPER LEVEL SYSTEM AS IT TRANSLATES THROUGH THE ROCKIES AND ONTO THE PLAINS. THUS WILL UTILIZE THE MODEL BLEND SOLUTION FOR POPS. IT LOOKS TO BE MILD MONDAY AND TUESDAY AHEAD OF THE SYSTEM WITH HIGHS IN THE 60S TO 70S. TEMPERATURES WILL THEN COOL BACK TO NEAR NORMAL WEDNESDAY. THURSDAY AND THURSDAY NIGHT ARE LOOKING TO BE COOL AND WET...BUT HOW COOL AND HOW WET ARE YET TO BE DETERMINED. DEFINITELY AN UNSETTLED PATTERN IN STORE MID TO LATE WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 1022 AM CDT THU APR 9 2015 ALL TERMINALS WILL REMAIN VFR TODAY AND TONIGHT. A FAIRLY LARGE BUT SHALLOW CUMULUS CANOPY WILL FORM ACROSS WESTERN AND CENTRAL NORTH DAKOTA BETWEEN 18Z THURSDAY THROUGH 00Z FRIDAY. GUSTY NORTHWEST WINDS OF 15KT TO 25 KT WILL ALSO BE COMMON THIS AFTERNOON. WINDS WILL DIMINISH TOWARD SUNSET...WITH THE CUMULUS DISSIPATING AS WELL WITH SKC TO FOLLOW THURSDAY NIGHT. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...NH SHORT TERM...KS LONG TERM...TWH AVIATION...TWH/NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
631 AM CDT THU APR 9 2015 .UPDATE... ISSUED AT 630 AM CDT THU APR 9 2015 PRECIPITATION IS MOVING OUT OF THE FAR SOUTHEAST CWA. HAVE A SLIGHT CHANCE FOR A COUPLE MORE HOUR OVER MAINLY DICKEY COUNTY. OTHERWISE DRY ELSEWHERE FOR THIS MORNING. COULD BE A FEW SHOWERS THIS AFTERNOON...SEE DISCUSSION BELOW...BUT FOR NOW WILL KEEP IT DRY. MADE SOME MINOR UPDATES TO SKY COVER BASED ON LATEST SATELLITE IMAGERY. OTHERWISE NO SIGNIFICANT CHANGES THIS MORNING. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 355 AM CDT THU APR 9 2015 HIGHLIGHTS IN THE SHORT TERM IS A TRANSITION FROM SOUTHWEST FLOW ALOFT EARLY THIS MORNING TO A MORE NORTHERLY FLOW LATER TODAY THROUGH THURSDAY NIGHT. A FEW POPCORN TYPE SHOWERS COULD DEVELOP AHEAD OF AN ADVANCING SHORTWAVE TROUGH AND SURFACE COLD FRONT THIS AFTERNOON ACROSS PORTIONS OF WESTERN AND NORTH CENTRAL NORTH DAKOTA. THE LATEST HRRR CEILING FORECAST SHOWS A FAIRLY LARGE CUMULUS FIELD DEVELOPING AFTER 18Z THROUGH 00Z. HOWEVER THE DEPTH OF THE CUMULUS FIELD PER BUFKIT SOUNDINGS LOOKS SHALLOW TO SUPPORT MUCH PRECIPITATION ACTIVITY. THE NET EFFECT MAY ACTUALLY INCREASE WIND GUSTS BRIEFLY WITH ANY EVAPORATIONAL COOLING BENEATH THE CLOUD BASE. BUFKIT SOUNDINGS SHOW A WELL ESTABLISHED MIXED LAYER TODAY...WHEREAS THE PREVIOUS SHIFTS HAD THIS WELL COVERED. THUS EXPECT BREEZY/WINDY CONDITIONS WITH WINDS 20 TO 30 MPH THIS AFTERNOON. IN TERMS OF POPS TODAY...FOR NOW HAVE INCREASED THEM TO 14 FOR THE WEST AND NORTH CENTRAL AND WILL LET THE DAY SHIFT RE-EVALUATE THE MORNING DATA AS TO WHETHER OR NOT TO ADD A FEW POPCORN SHOWERS THIS AFTERNOON. FOR THE NEAR TERM...THROUGH 12Z-15Z THURSDAY...PRECIPITATION CONTINUES TO WANE OVER THE SOUTHEAST AS THE UPPER LOW ACROSS SOUTHEAST WYOMING IS SHIFTING THE BEST LIFT FARTHER EAST. CURRENT FOG/STRATUS LOOP CONTINUES TO SHOW PATCHY FOG/LOW CLOUDS ACROSS THE SOUTHWEST AND SOUTH CENTRAL. THIS WILL SLOWLY SHIFT EAST THROUGH THE EARLY MORNING. THE LATEST WATER VAPOR IMAGERY LOOP SHOWS THE SOUTHERN BRANCH UPPER FLOW INTO CENTRAL NORTH DAKOTA IS SLOWLY WEAKENING...AS A NORTHERN STREAM SHORTWAVE IS PUSHING THROUGH NORTHWEST NORTH DAKOTA EARLY THIS MORNING. THIS WILL PUSH THE INFLUX OF MOISTURE FARTHER EAST WITH THE EROSION OF STRATUS ACROSS THE SOUTH THROUGH MID MORNING. ANOTHER SHORTWAVE SEEN NEAR THE NORTHEAST BORDER OF SASKATCHEWAN/MANITOBA...WILL SHIFT INTO LAKE MANITOBA BY 18Z THURSDAY AND THEN DIVE SOUTH INTO FAR EASTERN NORTH DAKOTA BY 12Z FRIDAY. A SURFACE COLD FRONT IS ASSOCIATED WITH THIS SHORTWAVE. EXPECT LOW LEVEL WARMING TODAY AHEAD OF IT WITH H85 TEMPS RISING TO BETWEEN +2C AND +4C ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE COLD FRONT WILL MAKE IT INTO NORTH CENTRAL NORTH DAKOTA BETWEEN 18Z AND 21Z. AFTERNOON HIGH TEMPERATURES WILL REACH INTO THE 50S ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE NAM/ECMWF AGREE WITH SOME POTENTIAL OF A SHOWER OR TWO IN NORTH CENTRAL NORTH DAKOTA THIS AFTERNOON. THE HI RESOLUTION ARW WEST AND NMM WEST ALSO SHOW A FEW LIGHT MEASURABLE QPF STRIATIONS DEVELOPING ACROSS THE WEST AND SOUTHWEST. UNCERTAINTY REMAINS WITH ANY DEVELOPMENT AND LOCATION AT THIS TIME...THUS WILL KEEP THINGS DRY AND MONITOR THE DATA LATER THIS MORNING INTO THE AFTERNOON. THE COLD FRONT WILL SLIDE FROM NORTH TO SOUTH THROUGH THURSDAY EVENING FOLLOWED BY A CLEARING SKY AROUND SUNSET...AS ANY CUMULUS WILL COLLAPSE AND DISSIPATE QUICKLY. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 355 AM CDT THU APR 9 2015 THE MAIN FORECAST ISSUES IN THE LONG TERM PERIOD ARE LATE IN THE PERIOD ASSOCIATED WITH AN UPPER LEVEL LOW TRACKING FROM THE WESTERN U.S. INTO THE PLAINS. BEFORE THAT...RATHER QUIET BUT WITH A FEW POSSIBLE FIRE WEATHER ISSUES. DETERMINISTIC MODELS ARE IN A LITTLE BETTER AGREEMENT WITH THE LATE PERIOD SYSTEM. IN GENERAL ECMWF HAS COME INTO BETTER AGREEMENT WITH THE GFS. ENSEMBLE SPREAD HAS ALSO NARROWED SOME...BUT GFSENSEMBLE IS STILL GIVING A RATHER LARGE ENVELOPE OF SOLUTIONS WITH THE PLACEMENT OF THE MID-UPPER LEVEL LOW AT 12 UTC THURSDAY. THUS WILL STICK CLOSE TO THE MODEL BLEND SOLUTION. FRIDAY SHOULD BE A NICE DAY...BUT DID DROP TEMPERATURES JUST A BIT FROM THE PREVIOUS FORECAST. A WAVE DROPPING DOWN THE BUILDING UPPER RIDGE DROPS ALMOST DUE SOUTH ACROSS MINNESOTA DRAGGING SOME COOLER AIR SOUTH INTO THE FORECAST AREA. HIGHS STILL MAINLY IN THE 50S. WE WARM NICELY ON SATURDAY AS SURFACE HIGH PRESSURE AND UPPER LEVEL RIDGING MOVE EAST AND SOUTHERLY RETURN FLOW KICKS IN. WE DO SEE RELATIVE HUMIDITIES DROP INTO THE LOW TO MID 20S SOUTH AND WEST OF LAKE SAKAKAWEA AND THE MISSOURI RIVER. HOWEVER...WINDS AT THE TOP OF THE MIXING LAYER ARE GENERALLY 15 TO 20 KNOTS. SOMETHING TO KEEP AN EYE ON...BUT FIRE WEATHER HAZARDS ARE NOT ANTICIPATED AT THIS TIME. A COLD FRONT MOVE THROUGH THE AREA SATURDAY NIGHT. MOISTURE IS LIMITED AHEAD OF THE FRONT AND ONLY INCREASES IN THE MID AND UPPER LEVELS BEHIND THE FRONT. DO EXPECT SOME GUSTY WINDS WITH THE FRONTAL PASSAGE...WITH POSSIBLY SOME ISOLATED SHOWERS REACHING THE GROUND BEHIND THE SURFACE COLD FRONT LATE SATURDAY NIGHT INTO EARLY SUNDAY MORNING ASSOCIATED WITH THE PASSAGE OF THE MID LEVEL SHORTWAVE TROUGH. IT WILL REMAIN WINDY THROUGHOUT THE DAY SUNDAY WITH TEMPERATURES AROUND 10 DEGREES COLDER THAN SATURDAY. WE STILL SEE SOME LOWER 20 PERCENT RELATIVE HUMIDITIES SUNDAY AFTERNOON OVER THE SOUTHWEST. THESE HUMIDITIES...COMBINED WITH THE STRONG WINDS WILL RESULT IN HIGHER FIRE WEATHER CONCERNS. THE COOLER TEMPERATURES SUNDAY AND RECENT MOISTURE WILL BE LIMITING FACTORS...BUT WITH STRONG WINDS AND NEAR 20 PERCENT HUMIDITIES...WILL CERTAINLY NEED TO MONITOR. LOOKS LIKE A COUPLE OF DRY DAYS MONDAY AND TUESDAY AHEAD OF THE APPROACHING UPPER LEVEL TROUGH. THE ECMWF DOES SHOW SOME LIGHT SHOWERS OVER THE AREA TUESDAY...BUT HAS BACKED OFF SIGNIFICANTLY ON THE COLD WET TUESDAY SOLUTION OF 24 HOURS AGO...AND IS MORE IN LINE WITH THE WARMER AND DRIER GFS. HOWEVER...BEYOND TUESDAY THERE REMAINS MUCH UNCERTAINTY IN THE EVOLUTION OF THE UPPER LEVEL SYSTEM AS IT TRANSLATES THROUGH THE ROCKIES AND ONTO THE PLAINS. THUS WILL UTILIZE THE MODEL BLEND SOLUTION FOR POPS. IT LOOKS TO BE MILD MONDAY AND TUESDAY AHEAD OF THE SYSTEM WITH HIGHS IN THE 60S TO 70S. TEMPERATURES WILL THEN COOL BACK TO NEAR NORMAL WEDNESDAY. THURSDAY AND THURSDAY NIGHT ARE LOOKING TO BE COOL AND WET...BUT HOW COOL AND HOW WET ARE YET TO BE DETERMINED. DEFINITELY AN UNSETTLED PATTERN IN STORE MID TO LATE WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 630 AM CDT THU APR 9 2015 VFR CIGS WILL RETURN TO KDIK BETWEEN 12Z AND 13Z THURSDAY...AND MAY BE IN AND OUT THROUGH 15Z WITH SOME SCATTERED IFR CEILING IN THE NEIGHBORHOOD. THE REST OF THE TERMINALS WILL REMAIN VFR. A FAIRLY LARGE BUT SHALLOW CUMULUS CANOPY WILL FORM ACROSS WESTERN AND CENTRAL NORTH DAKOTA BETWEEN 18Z THURSDAY THROUGH 00Z FRIDAY. GUSTY NORTHWEST WINDS OF 15KT TO 25 KT WILL ALSO BE COMMON THIS AFTERNOON. WINDS WILL DIMINISH TOWARD SUNSET...WITH THE CUMULUS DISSIPATING AS WELL WITH SKC TO FOLLOW THURSDAY NIGHT. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH SHORT TERM...KS LONG TERM...TWH AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
355 AM CDT THU APR 9 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 355 AM CDT THU APR 9 2015 HIGHLIGHTS IN THE SHORT TERM IS A TRANSITION FROM SOUTHWEST FLOW ALOFT EARLY THIS MORNING TO A MORE NORTHERLY FLOW LATER TODAY THROUGH THURSDAY NIGHT. A FEW POPCORN TYPE SHOWERS COULD DEVELOP AHEAD OF AN ADVANCING SHORTWAVE TROUGH AND SURFACE COLD FRONT THIS AFTERNOON ACROSS PORTIONS OF WESTERN AND NORTH CENTRAL NORTH DAKOTA. THE LATEST HRRR CEILING FORECAST SHOWS A FAIRLY LARGE CUMULUS FIELD DEVELOPING AFTER 18Z THROUGH 00Z. HOWEVER THE DEPTH OF THE CUMULUS FIELD PER BUFKIT SOUNDINGS LOOKS SHALLOW TO SUPPORT MUCH PRECIPITATION ACTIVITY. THE NET EFFECT MAY ACTUALLY INCREASE WIND GUSTS BRIEFLY WITH ANY EVAPORATIONAL COOLING BENEATH THE CLOUD BASE. BUFKIT SOUNDINGS SHOW A WELL ESTABLISHED MIXED LAYER TODAY...WHEREAS THE PREVIOUS SHIFTS HAD THIS WELL COVERED. THUS EXPECT BREEZY/WINDY CONDITIONS WITH WINDS 20 TO 30 MPH THIS AFTERNOON. IN TERMS OF POPS TODAY...FOR NOW HAVE INCREASED THEM TO 14 FOR THE WEST AND NORTH CENTRAL AND WILL LET THE DAY SHIFT RE-EVALUATE THE MORNING DATA AS TO WHETHER OR NOT TO ADD A FEW POPCORN SHOWERS THIS AFTERNOON. FOR THE NEAR TERM...THROUGH 12Z-15Z THURSDAY...PRECIPITATION CONTINUES TO WANE OVER THE SOUTHEAST AS THE UPPER LOW ACROSS SOUTHEAST WYOMING IS SHIFTING THE BEST LIFT FARTHER EAST. CURRENT FOG/STRATUS LOOP CONTINUES TO SHOW PATCHY FOG/LOW CLOUDS ACROSS THE SOUTHWEST AND SOUTH CENTRAL. THIS WILL SLOWLY SHIFT EAST THROUGH THE EARLY MORNING. THE LATEST WATER VAPOR IMAGERY LOOP SHOWS THE SOUTHERN BRANCH UPPER FLOW INTO CENTRAL NORTH DAKOTA IS SLOWLY WEAKENING...AS A NORTHERN STREAM SHORTWAVE IS PUSHING THROUGH NORTHWEST NORTH DAKOTA EARLY THIS MORNING. THIS WILL PUSH THE INFLUX OF MOISTURE FARTHER EAST WITH THE EROSION OF STRATUS ACROSS THE SOUTH THROUGH MID MORNING. ANOTHER SHORTWAVE SEEN NEAR THE NORTHEAST BORDER OF SASKATCHEWAN/MANITOBA...WILL SHIFT INTO LAKE MANITOBA BY 18Z THURSDAY AND THEN DIVE SOUTH INTO FAR EASTERN NORTH DAKOTA BY 12Z FRIDAY. A SURFACE COLD FRONT IS ASSOCIATED WITH THIS SHORTWAVE. EXPECT LOW LEVEL WARMING TODAY AHEAD OF IT WITH H85 TEMPS RISING TO BETWEEN +2C AND +4C ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE COLD FRONT WILL MAKE IT INTO NORTH CENTRAL NORTH DAKOTA BETWEEN 18Z AND 21Z. AFTERNOON HIGH TEMPERATURES WILL REACH INTO THE 50S ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE NAM/ECMWF AGREE WITH SOME POTENTIAL OF A SHOWER OR TWO IN NORTH CENTRAL NORTH DAKOTA THIS AFTERNOON. THE HI RESOLUTION ARW WEST AND NMM WEST ALSO SHOW A FEW LIGHT MEASURABLE QPF STRIATIONS DEVELOPING ACROSS THE WEST AND SOUTHWEST. UNCERTAINTY REMAINS WITH ANY DEVELOPMENT AND LOCATION AT THIS TIME...THUS WILL KEEP THINGS DRY AND MONITOR THE DATA LATER THIS MORNING INTO THE AFTERNOON. THE COLD FRONT WILL SLIDE FROM NORTH TO SOUTH THROUGH THURSDAY EVENING FOLLOWED BY A CLEARING SKY AROUND SUNSET...AS ANY CUMULUS WILL COLLAPSE AND DISSIPATE QUICKLY. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 355 AM CDT THU APR 9 2015 THE MAIN FORECAST ISSUES IN THE LONG TERM PERIOD ARE LATE IN THE PERIOD ASSOCIATED WITH AN UPPER LEVEL LOW TRACKING FROM THE WESTERN U.S. INTO THE PLAINS. BEFORE THAT...RATHER QUIET BUT WITH A FEW POSSIBLE FIRE WEATHER ISSUES. DETERMINISTIC MODELS ARE IN A LITTLE BETTER AGREEMENT WITH THE LATE PERIOD SYSTEM. IN GENERAL ECMWF HAS COME INTO BETTER AGREEMENT WITH THE GFS. ENSEMBLE SPREAD HAS ALSO NARROWED SOME...BUT GFSENSEMBLE IS STILL GIVING A RATHER LARGE ENVELOPE OF SOLUTIONS WITH THE PLACEMENT OF THE MID-UPPER LEVEL LOW AT 12 UTC THURSDAY. THUS WILL STICK CLOSE TO THE MODEL BLEND SOLUTION. FRIDAY SHOULD BE A NICE DAY...BUT DID DROP TEMPERATURES JUST A BIT FROM THE PREVIOUS FORECAST. A WAVE DROPPING DOWN THE BUILDING UPPER RIDGE DROPS ALMOST DUE SOUTH ACROSS MINNESOTA DRAGGING SOME COOLER AIR SOUTH INTO THE FORECAST AREA. HIGHS STILL MAINLY IN THE 50S. WE WARM NICELY ON SATURDAY AS SURFACE HIGH PRESSURE AND UPPER LEVEL RIDGING MOVE EAST AND SOUTHERLY RETURN FLOW KICKS IN. WE DO SEE RELATIVE HUMIDITIES DROP INTO THE LOW TO MID 20S SOUTH AND WEST OF LAKE SAKAKAWEA AND THE MISSOURI RIVER. HOWEVER...WINDS AT THE TOP OF THE MIXING LAYER ARE GENERALLY 15 TO 20 KNOTS. SOMETHING TO KEEP AN EYE ON...BUT FIRE WEATHER HAZARDS ARE NOT ANTICIPATED AT THIS TIME. A COLD FRONT MOVE THROUGH THE AREA SATURDAY NIGHT. MOISTURE IS LIMITED AHEAD OF THE FRONT AND ONLY INCREASES IN THE MID AND UPPER LEVELS BEHIND THE FRONT. DO EXPECT SOME GUSTY WINDS WITH THE FRONTAL PASSAGE...WITH POSSIBLY SOME ISOLATED SHOWERS REACHING THE GROUND BEHIND THE SURFACE COLD FRONT LATE SATURDAY NIGHT INTO EARLY SUNDAY MORNING ASSOCIATED WITH THE PASSAGE OF THE MID LEVEL SHORTWAVE TROUGH. IT WILL REMAIN WINDY THROUGHOUT THE DAY SUNDAY WITH TEMPERATURES AROUND 10 DEGREES COLDER THAN SATURDAY. WE STILL SEE SOME LOWER 20 PERCENT RELATIVE HUMIDITIES SUNDAY AFTERNOON OVER THE SOUTHWEST. THESE HUMIDITIES...COMBINED WITH THE STRONG WINDS WILL RESULT IN HIGHER FIRE WEATHER CONCERNS. THE COOLER TEMPERATURES SUNDAY AND RECENT MOISTURE WILL BE LIMITING FACTORS...BUT WITH STRONG WINDS AND NEAR 20 PERCENT HUMIDITIES...WILL CERTAINLY NEED TO MONITOR. LOOKS LIKE A COUPLE OF DRY DAYS MONDAY AND TUESDAY AHEAD OF THE APPROACHING UPPER LEVEL TROUGH. THE ECMWF DOES SHOW SOME LIGHT SHOWERS OVER THE AREA TUESDAY...BUT HAS BACKED OFF SIGNIFICANTLY ON THE COLD WET TUESDAY SOLUTION OF 24 HOURS AGO...AND IS MORE IN LINE WITH THE WARMER AND DRIER GFS. HOWEVER...BEYOND TUESDAY THERE REMAINS MUCH UNCERTAINTY IN THE EVOLUTION OF THE UPPER LEVEL SYSTEM AS IT TRANSLATES THROUGH THE ROCKIES AND ONTO THE PLAINS. THUS WILL UTILIZE THE MODEL BLEND SOLUTION FOR POPS. IT LOOKS TO BE MILD MONDAY AND TUESDAY AHEAD OF THE SYSTEM WITH HIGHS IN THE 60S TO 70S. TEMPERATURES WILL THEN COOL BACK TO NEAR NORMAL WEDNESDAY. THURSDAY AND THURSDAY NIGHT ARE LOOKING TO BE COOL AND WET...BUT HOW COOL AND HOW WET ARE YET TO BE DETERMINED. DEFINITELY AN UNSETTLED PATTERN IN STORE MID TO LATE WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 355 AM CDT THU APR 9 2015 LIFR CIGS/VSBYS WILL CONTINUE AT KDIK THROUGH 14Z BEFORE IMPROVING BACK TO VFR BY 16Z-17Z. ELSEWHERE...MVFR CIGS AND VSBYS POSSIBLE AT KBIS/KJMS THROUGH 14Z. MVFR VSBYS ALSO POSSIBLE AT KISN/KMOT AS SURROUNDING SITES SUCH AS WATFORD CITY AND TIOGA REPORTING VISIBILITIES BETWEEN 2SM AND 6SM. ALL TERMINALS ARE EXPECTED TO RETURN TOWARD VFR STATUS BY 15Z-17Z TODAY. EXPECT A FAIRLY LARGE BUT SHALLOW CUMULUS FORMATION ACROSS WESTERN AND CENTRAL NORTH DAKOTA 18Z THURSDAY THROUGH 00Z FRIDAY. THE CUMULUS WILL DISSIPATE QUICKLY AROUND SUNSET WITH A CLEAR SKY TO FOLLOW THROUGH 12Z FRIDAY. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KS LONG TERM...TWH AVIATION...KS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
625 PM EDT THU APR 9 2015 .SYNOPSIS... LOW PRESSURE WILL MOVE THROUGH THE CENTRAL GREAT LAKES TONIGHT AND DRAG A COLD FRONT THROUGH THE AREA. A SECONDARY COLD FRONT WILL DROP ACROSS THE AREA FRIDAY EVENING. HIGH PRESSURE WILL BUILD IN FOR SATURDAY AND SUNDAY && .NEAR TERM /THROUGH FRIDAY NIGHT/... UPDATED FORECAST TO ALLOW FOR A LITTLE SUNSHINE IN NW OHIO. THE LOCAL AREA IS CURRENTLY PRETTY QUIET. WILL HAVE TO WAIT AND SEE IF CONVECTION NEAR CINCINNATI HOLDS TOGETHER. OTHER STORMS COULD ALSO DEVELOP THIS EVENING IN THE WEST BUT EXPECTED THE BRUNT OF THE PRECIP TONIGHT TO OCCUR AFTER MIDNIGHT AS COLD FRONT APPROACHES. PREVIOUS...USED A MIX OF THE HRRR AND SREF FOR TRENDS THROUGH THE EVENING AND OVERNIGHT. RAIN ACROSS NORTHERN OHIO SHIFTING NORTHEAST QUICKLY AND IS NOW MAINLY IN NERN OHIO AND NWRN PA. ANOTHER AREA OF SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE SOUTHERN AND EASTERN COUNTIES THROUGH THE EVENING AS WELL. NOT A LOT OCCURRING IN THE WESTERN HALF OF THE AREA ALTHOUGH DO EXPECT SCATTERED CONVECTION WILL DEVELOP/MOVE IN. THROUGH THE EARLY EVENING WILL SHIFT HIGH POPS NORTH OF THE AREA FOR A SHORT WHILE DROPPING MOST TO CHANCE. AFTER MIDNIGHT COLD FRONT MOVES IN FROM THE WEST. EXPECT SHOWERS AND THUNDERSTORMS ALONG AND AHEAD OF THE BOUNDARY. WILL HAVE CAT POPS COMING BACK FOR THE OVERNIGHT AND THEN WILL ATTEMPT TO MOVE THIS EAST DURING THE EARLY MORNING HOURS WHILE ALSO MOVING DRYING IN FROM THE WEST. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... FRIDAY MORNING 12Z THE COLD FRONT SHOULD BE JUST EAST OF KCLE WITH DRYING MOVING IN FROM THE WEST. WILL HANG ONTO A CHANCE OF THUNDER EAST THROUGH THE FIRST HALF OF THE MORNING BUT EXPECT PRECIP TO END BY LATE MORNING. WILL ALLOW FOR SS TO BREAK THROUGH DURING THE DAY BUT AM STILL A BIT SKEPTICAL GIVEN LOW LEVEL RH REMAINING ACROSS THE AREA. ANOTHER BIG CONCERN FOR FRIDAY WILL BE WINDS. 850MB FLOW INCREASES TO 50 KNOTS ACROSS THE AREA LATE TONIGHT WITH 40-45 KNOTS AT 925MB. THIS CONTINUES POST COLD FRONT. AT THIS TIME IT DOESNT LOOK LIKE WARNING LEVELS WILL BE REACHED BUT COULD REQUIRE A WIND ADVISORY. IF THIS CONTINUES WILL LIKELY ISSUE ON THE EVENING OR OVERNIGHT FORECAST PACKAGE. BOTH THE NAM AND GFS CONTINUE TO SHOW A SECONDARY COLD FRONT/UPPER SHORT WAVE MOVING THROUGH DURING THE EVENING AND EARLY OVERNIGHT FRIDAY NIGHT. WILL BRING CLOUDS BACK AS WELL AS A SMALL CHANCE POPS. DRY AIR AND HIGH PRESSURE BUILD IN FOR SATURDAY AND SUNDAY. && .LONG TERM /MONDAY THROUGH THURSDAY/... MODELS GENERALLY AGREE WITH WEAK COLD FRONT PUSHING SE ACROSS THE AREA MON SO WILL MAINTAIN DECENT THREAT FOR SHRA. THE FRONT IS SHOWN TO MOVE FAR ENOUGH SOUTH OF THE AREA TO PROBABLY ALLOW FOR DRY CONDITIONS ON TUE WITH WEAK HIGH PRESSURE OVER THE AREA. WED THRU FRI...A SLOW MOVING UPPER LOW OVER THE PLAINS WILL DRIFT NE CAUSING A LOW TO LIFT NE TOWARD LAKE MICHIGAN BY LATE FRI. THE STALLED FRONT WILL SLOWLY LIFT NORTH INTO THE REGION AS A WARM FRONT PROVIDING A FOCUS FOR SHRA AND TSRA TO START SPREADING NE OVER THE AREA WED INTO WED NIGHT AND CONTINUE ON THU...AND PROBABLY FOR SEVERAL MOVE DAYS AFTER THAT. TEMPS UNCERTAIN AS THE NORTHERN PART OF THE CWA MAY SEE NE WINDS AHEAD OF THE FRONT THUS PRODUCING A COOL FLOW OFF OF LAKE ERIE WHILE THE SOUTHERN COUNTIES HAVE A GOOD CHANCE OF SEEING TEMPS WELL INTO THE 60S ANY MAYBE SOME 70S. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... ROUNDS OF SHRA/TSRA WILL CONTINUE TO AFFECT THE AREA INTO FRI MORNING UNTIL A COLD FRONT SWEEPS ACROSS THE AREA TO END THE THREAT. WIDESPREAD VFR SHOULD BE THE PREDOMINATE CONDITIONS OUTSIDE OF THE CONVECTION WITH AREAS OF MVFR/LOCAL IFR IN THE HEAVIER TSRA. SOUTH TO SSW WINDS WILL INCREASE THIS AFTERNOON AND TONIGHT TO BE GUSTING 25 TO 35 KNOTS TONIGHT WITH GUSTS AROUND 40 KNOTS ON FRI. THE STRONGER TSRA CAN EASILY PRODUCE GUSTS TO 50 KNOTS WITH SOME LARGE HAIL POSSIBLE. .OUTLOOK..SOME NON VFR POSSIBLE ACROSS NRN OH/NW PA LATE FRIDAY AND FRI NIGHT THEN JUST NW PA FOR EARLY SATURDAY MORNING. NON VFR POSSIBLE AGAIN FOR MONDAY. && .MARINE... A STRONG COLD FRONT SWEEPING ACROSS LAKE ERIE LATE TONIGHT AND FRIDAY MORNING AND THE FOLLOWING COLD ADVECTION SHOULD BE ABLE TO PRODUCE GALE FORCE WINDS FOR A WHILE. WILL GO WITH LOW END GALES FOR A WHILE ON FRI. THE PRESSURE GRADIENT STARTS TO WEAKEN LATER FRI INTO FRI NIGHT SO WINDS SHOULD SLOWLY START DIMINISHING THEN BECOME LIGHT BY SAT EVE AS HIGH PRESSURE MOVES ACROSS OHIO INTO PA. A RETURN SOUTHERLY FLOW SHOULD SET UP IN THE WAKE OF THE HIGH FOR SUN INCREASING TO ABOUT 10 TO 20 KNOTS FOR SUN NIGHT AHEAD OF A WEAK COLD FRONT THAT CROSSES THE LAKE MON. WEAK HIGH PRESSURE QUICKLY BUILDS IN BY MON NIGHT SO WINDS WILL DIMINISH AND SHOULD STAY FAIRLY LIGHT THRU TUE. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR OHZ029>032- 036>038-047. PA...NONE. MARINE...GALE WARNING FROM 6 AM TO 4 PM EDT FRIDAY FOR LEZ061-142>149- 162>169. && $$ SYNOPSIS...TK NEAR TERM...TK/KUBINA SHORT TERM...TK LONG TERM...ADAMS AVIATION...ADAMS MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
340 PM EDT THU APR 9 2015 .SYNOPSIS... LOW PRESSURE WILL MOVE THROUGH THE CENTRAL GREAT LAKES TONIGHT AND DRAG A COLD FRONT THROUGH THE AREA. A SECONDARY COLD FRONT WILL DROP ACROSS THE AREA FRIDAY EVENING. HIGH PRESSURE WILL BUILD IN FOR SATURDAY AND SUNDAY && .NEAR TERM /THROUGH TONIGHT/... USED A MIX OF THE HRRR AND SREF FOR TRENDS THROUGH THE EVENING AND OVERNIGHT. RAIN ACROSS NORTHERN OHIO SHIFTING NORTHEAST QUICKLY AND IS NOW MAINLY IN NERN OHIO AND NWRN PA. ANOTHER AREA OF SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE SOUTHERN AND EASTERN COUNTIES THROUGH THE EVENING AS WELL. NOT A LOT OCCURRING IN THE WESTERN HALF OF THE AREA ALTHOUGH DO EXPECT SCATTERED CONVECTION WILL DEVELOP/MOVE IN. THROUGH THE EARLY EVENING WILL SHIFT HIGH POPS NORTH OF THE AREA FOR A SHORT WHILE DROPPING MOST TO CHANCE. AFTER MIDNIGHT COLD FRONT MOVES IN FROM THE WEST. EXPECT SHOWERS AND THUNDERSTORMS ALONG AND AHEAD OF THE BOUNDARY. WILL HAVE CAT POPS COMING BACK FOR THE OVERNIGHT AND THEN WILL ATTEMPT TO MOVE THIS EAST DURING THE EARLY MORNING HOURS WHILE ALSO MOVING DRYING IN FROM THE WEST. && .SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/... FRIDAY MORNING 12Z THE COLD FRONT SHOULD BE JUST EAST OF KCLE WITH DRYING MOVING IN FROM THE WEST. WILL HANG ONTO A CHANCE OF THUNDER EAST THROUGH THE FIRST HALF OF THE MORNING BUT EXPECT PRECIP TO END BY LATE MORNING. WILL ALLOW FOR SS TO BREAK THROUGH DURING THE DAY BUT AM STILL A BIT SKEPTICAL GIVEN LOW LEVEL RH REMAINING ACROSS THE AREA. ANOTHER BIG CONCERN FOR FRIDAY WILL BE WINDS. 850MB FLOW INCREASES TO 50 KNOTS ACROSS THE AREA LATE TONIGHT WITH 40-45 KNOTS AT 925MB. THIS CONTINUES POST COLD FRONT. AT THIS TIME IT DOESNT LOOK LIKE WARNING LEVELS WILL BE REACHED BUT COULD REQUIRE A WIND ADVISORY. IF THIS CONTINUES WILL LIKELY ISSUE ON THE EVENING OR OVERNIGHT FORECAST PACKAGE. BOTH THE NAM AND GFS CONTINUE TO SHOW A SECONDARY COLD FRONT/UPPER SHORT WAVE MOVING THROUGH DURING THE EVENING AND EARLY OVERNIGHT FRIDAY NIGHT. WILL BRING CLOUDS BACK AS WELL AS A SMALL CHANCE POPS. DRY AIR AND HIGH PRESSURE BUILD IN FOR SATURDAY AND SUNDAY. && .LONG TERM /MONDAY THROUGH THURSDAY/... MODELS GENERALLY AGREE WITH WEAK COLD FRONT PUSHING SE ACROSS THE AREA MON SO WILL MAINTAIN DECENT THREAT FOR SHRA. THE FRONT IS SHOWN TO MOVE FAR ENOUGH SOUTH OF THE AREA TO PROBABLY ALLOW FOR DRY CONDITIONS ON TUE WITH WEAK HIGH PRESSURE OVER THE AREA. WED THRU FRI...A SLOW MOVING UPPER LOW OVER THE PLAINS WILL DRIFT NE CAUSING A LOW TO LIFT NE TOWARD LAKE MICHIGAN BY LATE FRI. THE STALLED FRONT WILL SLOWLY LIFT NORTH INTO THE REGION AS A WARM FRONT PROVIDING A FOCUS FOR SHRA AND TSRA TO START SPREADING NE OVER THE AREA WED INTO WED NIGHT AND CONTINUE ON THU...AND PROBABLY FOR SEVERAL MOVE DAYS AFTER THAT. TEMPS UNCERTAIN AS THE NORTHERN PART OF THE CWA MAY SEE NE WINDS AHEAD OF THE FRONT THUS PRODUCING A COOL FLOW OFF OF LAKE ERIE WHILE THE SOUTHERN COUNTIES HAVE A GOOD CHANCE OF SEEING TEMPS WELL INTO THE 60S ANY MAYBE SOME 70S. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... ROUNDS OF SHRA/TSRA WILL CONTINUE TO AFFECT THE AREA INTO FRI MORNING UNTIL A COLD FRONT SWEEPS ACROSS THE AREA TO END THE THREAT. WIDESPREAD VFR SHOULD BE THE PREDOMINATE CONDITIONS OUTSIDE OF THE CONVECTION WITH AREAS OF MVFR/LOCAL IFR IN THE HEAVIER TSRA. SOUTH TO SSW WINDS WILL INCREASE THIS AFTERNOON AND TONIGHT TO BE GUSTING 25 TO 35 KNOTS TONIGHT WITH GUSTS AROUND 40 KNOTS ON FRI. THE STRONGER TSRA CAN EASILY PRODUCE GUSTS TO 50 KNOTS WITH SOME LARGE HAIL POSSIBLE. .OUTLOOK..SOME NON VFR POSSIBLE ACROSS NRN OH/NW PA LATE FRIDAY AND FRI NIGHT THEN JUST NW PA FOR EARLY SATURDAY MORNING. NON VFR POSSIBLE AGAIN FOR MONDAY. && .MARINE... A STRONG COLD FRONT SWEEPING ACROSS LAKE ERIE LATE TONIGHT AND FRIDAY MORNING AND THE FOLLOWING COLD ADVECTION SHOULD BE ABLE TO PRODUCE GALE FORCE WINDS FOR A WHILE. WILL GO WITH LOW END GALES FOR A WHILE ON FRI. THE PRESSURE GRADIENT STARTS TO WEAKEN LATER FRI INTO FRI NIGHT SO WINDS SHOULD SLOWLY START DIMINISHING THEN BECOME LIGHT BY SAT EVE AS HIGH PRESSURE MOVES ACROSS OHIO INTO PA. A RETURN SOUTHERLY FLOW SHOULD SET UP IN THE WAKE OF THE HIGH FOR SUN INCREASING TO ABOUT 10 TO 20 KNOTS FOR SUN NIGHT AHEAD OF A WEAK COLD FRONT THAT CROSSES THE LAKE MON. WEAK HIGH PRESSURE QUICKLY BUILDS IN BY MON NIGHT SO WINDS WILL DIMINISH AND SHOULD STAY FAIRLY LIGHT THRU TUE. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR OHZ029>032- 036>038-047. PA...NONE. MARINE...GALE WARNING FROM 6 AM TO 4 PM EDT FRIDAY FOR LEZ061-142>149- 162>169. && $$ SYNOPSIS...TK NEAR TERM...TK SHORT TERM...TK LONG TERM...ADAMS AVIATION...ADAMS MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
253 PM EDT THU APR 9 2015 .SYNOPSIS... ROUNDS OF SHOWERS AND THUNDERSTORMS THROUGH FRIDAY. COLD FRONT CROSSES FRIDAY. HIGH PRESSURE FOR THE WEEKEND. COLD FRONT APPROACHES AND THEN STALLS FOR UNSETTLED WEATHER NEXT WEEK. && .NEAR TERM /THROUGH FRIDAY/... YET ANOTHER CONVECTIVE COMPLEX DEVELOPING TO OUR WEST...HOWEVER THE MEAN FLOW TODAY LOOKS TO KEEP THE STRONGEST STORMS TO OUR WEST...OR JUST CLIPPING THE WESTERN CWA. THE HIGHEST ML CAPE REMAINS WEST OF CWA...AND WOULD EXPECT STRONGEST STORMS TO STICK CLOSER TO THIS. WE ARE STILL FIRMLY WITHIN THE WARM SECTOR HOWEVER WITH CONVECTION POPPING UP ACROSS WV SOUTHWEST INTO SOUTHERN KENTUCKY...SO WILL STILL HAVE SHOWERS AND THUNDERSTORMS DRIFTING NE ACROSS FORECAST AREA THIS AFTERNOON...INTO THIS EVENING ACROSS THE NORTH. THINK THE BEST CHANCE OF WIDESPREAD SEVERE THUNDERSTORMS WILL REMAIN MOSTLY WEST OF FORECAST AREA. IN CWA BEST CHANCE LOOKS TO BE IN THE WESTERN THIRD OF CWA...ALONG THE OHIO RIVER AND WEST THIS AFTERNOON INTO EVENING. USED THE HRRR TO TIME THE BEST POPS...ALTHOUGH ISOLATED TO SCATTERED CONVECTION IS TOUGH TO GET EXACT. LOW TO MID LEVEL FLOW IS GENERALLY OUT OF THE SOUTHWEST...20-30KTS AROUND 925 MB...UP TO 50-60KTS AT 500MB. THIS WILL KEEP THINGS MOVING WHICH SHOULD HELP WITH WATER CONCERNS. MAIN CONCERN WATER-WISE WILL BE TRAINING CELLS...ESPECIALLY ALONG ANY OUTFLOW BOUNDARIES THAT LINGER PARALLEL TO THE FLOW. NO REASON TO MAKE ANY CHANGES TO THE FLASH FLOOD WATCH. IN THE WETTER AREAS...THAT WERE HIT LAST NIGHT BY HEAVY RAIN...IT WOULD LIKELY ONLY TAKE 1-1.5 INCHES IN 3 HOURS OR LESS TO START CAUSING PROBLEMS AGAIN...WHILE AREAS THAT HAVE NOT RECEIVED AS MUCH RAIN OVER THE LAST DAY OR TWO IT WOULD TAKE 1.5-2 IN 3 HOURS. TRIED TO SHOW A BREAK LATE THIS EVENING INTO TONIGHT...AS CONVECTION FROM THIS AFTERNOON EXITS TO THE NE...AND A COLD FRONT FINALLY APPROACHES FROM THE WNW. STILL HAVE ISOLATED SHOWERS/STORMS MENTIONED THROUGH THE NIGHT...AS WE REMAIN IN THE WARM SECTOR. COLD FRONT ARRIVES TO WESTERN ZONES FRIDAY MORNING. GFS/ECMWF ARE FAIRLY SIMILAR IN TIMING WITH THE FRONT...WHILE NAM LAGS BEHIND A BIT. DID NOT CHANGE PREVIOUS FORECAST TIMING A WHOLE LOT...BUT DID INCREASE POPS. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/... CURRENT FORECAST OF A DRY AND MILD WEEKEND CONTINUES ONT RACK...AS MODELS VERY CONSISTENT WITH HIGH PRESSURE DOMINATING THE OHIO VALLEY. LOOK FOR NEAR SEASONAL DAYTIME TEMPERATURES BUT CHILLY NIGHTS WITH A LARGE DIURNAL RANGE IN TEMPERATURES. && .LONG TERM /MONDAY THROUGH THURSDAY/... MODELS DEPICT ANOTHER FRONTAL SYSTEM MEANDERING BACK AND FORTH ACROSS OUR REGION FOR MUCH OF NEXT WEEK. WHILE SPECIFIC DETAILS MAY BE DIFFERENT FOR EACH SYSTEM THAT RUNS ALONG THIS FRONT...THE GENERAL SCENARIO IS FOR WARM...MOIST AND RELATIVELY UNSTABLE AIR IN PLACE TO PRESENT A CHANCE OF SHOWERS AND THUNDERSTORMS ANYTIME FOR MUCH OF THE WEEK. && .AVIATION /19Z THURSDAY THROUGH TUESDAY/... ISOLATED TO SCATTERED SHOWERS AND STORMS EXPECTED TODAY INTO TONIGHT. HARD TO TIME THESE INDIVIDUAL CELLS WITH NO REAL SURFACE FEATURE TO FOCUS ON...SO WENT WITH VCTS AND ANTICIPATE AMENDMENTS WILL BE NEEDED IF CELLS APPROACH INDIVIDUAL TAF SITES. MVFR TO IFR WOULD BE POSSIBLE. BETTER CONFIDENCE ON TIMING OF SHOWERS AND STORMS FRIDAY MORNING AS A COLD FRONT PASSES THROUGH. WINDS WILL GENERALLY BE OUT OF THE S/SW THROUGH TONIGHT...ALTHOUGH VARIABLE AND GUSTY IN AND AROUND CONVECTION. WINDS WILL BECOME WESTERLY BEHIND THE FRONT. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z FRIDAY... FORECAST CONFIDENCE: LOW. ALTERNATE SCENARIOS: TIMING AND RESTRICTIONS IN SHOWERS/STORMS COULD VARY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05 EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 CRW CONSISTENCY H H H M H H H H H H H H HTS CONSISTENCY H M M M H H H H H H H H BKW CONSISTENCY H H H H H H H H H M M M EKN CONSISTENCY H H H H H M M H H M M M PKB CONSISTENCY H H H M M M H H H H H H CKB CONSISTENCY H H H H H H M H H H H H AFTER 18Z FRIDAY... IFR IN SHOWERS/STORMS COULD STILL BE LINGERING ACROSS EAST FRIDAY AFTERNOON. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR WVZ005>011-013- 014-017-019-020. FLASH FLOOD WATCH THROUGH FRIDAY AFTERNOON FOR WVZ015-016-018- 024>032-037>040-046-047. OH...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR OHZ066-067-075- 076-083>087. KY...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ101>103-105. VA...NONE. && $$ SYNOPSIS...JMV/MZ NEAR TERM...MZ SHORT TERM...JMV LONG TERM...JMV AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1016 AM EDT THU APR 9 2015 .SYNOPSIS... ROUNDS OF SHOWERS AND THUNDERSTORMS THROUGH FRIDAY. COLD FRONT CROSSES FRIDAY. HIGH PRESSURE FOR THE WEEKEND. COLD FRONT APPROACHES AND THEN STALLS FOR UNSETTLED WEATHER EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... 1015 AM UPDATE...AS WITH THE PAST SEVERAL DAYS...THE HRRR IS BEGINNING TO LATCH ON TO YET ANOTHER CONVECTIVE COMPLEX FOR THIS AFTERNOON. HRRR DID FAIRLY WELL THE LAST COUPLE DAYS...SO USED THAT TO UPDATE POPS THROUGH THIS EVENING. EXPECTING A COMPLEX TO MOVE NE ACROSS CWA...WITH THE MAIN ACTIVITY ALONG AND WEST OF THE OHIO RIVER...AND MORE SCATTERED CONVECTION ACROSS EASTERN HALF OF CWA. PREVIOUS DISCUSSION...MODELS SHOWING SHOWERS AND THUNDERSTORMS CONTINUING OVER NORTHERN WEST VIRGINIA EARLY THIS MORNING. WITH MUCH OF THE AREA ALREADY SATURATED...FEEL THAT A FLASH FLOOD WATCH IS PRUDENT FOR THE REMAINDER OF THE NORTHERN WV COUNTIES IN OUR FORECAST AREA. WITH THUNDERSTORMS POSSIBLE AGAIN THIS AFTERNOON AND EVENING AND IN ADVANCE OF THE COLD FRONT ON FRIDAY...WILL GO AHEAD AND EXTEND THE ENTIRE FLASH FLOOD WATCH INTO FRIDAY. BASED ON MESO MODELS SHOWING PRE-FRONTAL PRECIPITATION WITH THE FRONTAL BOUNDARY LATE THURSDAY NIGHT...WILL SPEED UP AND INCREASE POPS SOME. && .SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/... PREFRONTAL BAND WILL BE RACING THRU AREA EARLY FRIDAY MORNING...FOLLOWED BY ACTUAL SURFACE FRONT. HOPEFULLY THIS PREFRONTAL BAND WILL BE ON A WEAKENING TREND AS IT COMES THRU GIVEN TIME OF DAY AND SEPARATION FROM BETTER DYNAMICS. STILL...A STOUT LLJ IS WORRISOME FOR DAMAGING WIND THREAT. THERE MAY BE SOME REJUVENATION ALONG THE ACTUAL COLD FRONT BY THE TIME IT GETS INTO THE MOUNTAINS BY LATE MORNING OR MIDDAY. MAY SEEM SOME SUN FRIDAY AFTERNOON AMID SOME BREEZY CONDITIONS IN THE DRY SLOT ALOFT. TRUE CAA HOLDS OFF UNTIL SATURDAY AS THE UPPER TROF SWINGS THRU. NOT EXPECTING ANY PRECIP JUST AN EXPANSIVE STRATOCU FIELD...MOST NOTICEABLE ACROSS N ZONES. HIGH PRESSURE BUILDS IN SATURDAY NIGHT AND WITH A CLEAR SKY...THINK THERE COULD BE SOME FROST CONCERNS IN THE LOWLANDS. WE HAVE NOT STARTED THE GROWING SEASON JUST YET...BUT SOMETHING TO KEEP IN MIND FOR THOSE EAGER GREEN THUMBS. THE HIGH SLIDES OFF TO THE E ON SUNDAY BUT STILL A NICE DAY WITH MILD TEMPS. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... NO SIGNIFICANT CHANGES WERE MADE TO THE EXTENDED PERIOD. WEEKEND STARTS OUT WARM AND DRY...AND HIGH PRESSURE...SURFACE AND ALOFT BUILDS IN. AN ACTIVE AND STORMY WEEK THEN TAKES HOLD NEXT WEEK...AS ANOTHER FRONTAL BOUNDARY...STALLS OUT ACROSS THE AREA BRIEFLY...BEFORE LIFTING BACK NORTH AS A WARM FRONT BY TUESDAY...WITH LOW PRESSURE MOVING NORTHEAST OUT OF THE SOUTHERN PLAINS TOWARDS THE OHIO VALLEY. THIS WILL PROVIDE THE SET UP FOR WARM...AND HUMID WEATHER ACROSS THE AREA...ALONG WITH CHANCES FOR THUNDERSTORMS IN THE INCREASINGLY MOIST AND UNSTABLE ATMOSPHERE. FOR NOW...BROAD BRUSHED POPS IN THE EXTENDED...WITH A DIURNAL TREND TO CONVECTION/HIGHER POPS. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... SCATTERED SHOWERS AND THUNDERSTORMS WILL REMAIN A POSSIBILITY THROUGH THE PERIOD...WITH STRONGER STORMS PROVIDING IFR RESTRICTIONS. SOME MVFR FOG/STRATUS IS POSSIBLE EARLY THIS MORNING IN AREAS RECENTLY RECEIVING RAINFALL. OUTSIDE OF THE PRECIPITATION...MOSTLY VFR CLOUDS CAN BE EXPECTED. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY... FORECAST CONFIDENCE: LOW. ALTERNATE SCENARIOS: TIMING AND RESTRICTIONS IN SHOWERS/STORMS COULD VARY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 12Z FRIDAY... BRIEF IFR POSSIBLE IN SHOWERS AND/OR THUNDERSTORMS FRIDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR WVZ005>011-013- 014-017-019-020. FLASH FLOOD WATCH THROUGH FRIDAY AFTERNOON FOR WVZ015-016-018- 024>032-037>040-046-047. OH...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR OHZ066-067-075- 076-083>087. KY...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR KYZ101>103-105. VA...NONE. && $$ SYNOPSIS...RPY/SL/30 NEAR TERM...RPY/MZ SHORT TERM...30 LONG TERM...SL AVIATION...RPY
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
139 AM EDT THU APR 9 2015 .SYNOPSIS... ROUNDS OF SHOWERS AND THUNDERSTORMS TONIGHT INTO THURSDAY NIGHT. COLD FRONT CROSSES FRIDAY. HIGH PRESSURE FOR THE WEEKEND. COLD FRONT APPROACHES AND THEN STALLS FOR UNSETTLED WEATHER EARLY NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... 830 PM UPDATE... EXPANDED FFA FARTHER N TO ACCOUNT FOR WHERE COMPLEX IS COMING IN FROM THE W...AND WENT ACROSS THE NRN TIER TO ACCOUNT FOR CONVECTION ALONG THE 300K ISENTROPIC SFC GRADIENT H8-H85 THERE. 745 PM UPDATE... UPDATED POPS FOR FASTER TIMING OF COMPLEX ENTERING AREA FROM THE W...AND TO REFLECT BAND OF CONVECTION ALONG 300K ISENTROPIC SFC GRADIENT H8-H85 ACROSS THE NRN TIER. 630 PM UPDATE... UPDATED POPS TO REFLECT NEXT COMPLEX COMING INTO OUR SRN AND CENTRAL ZONES AND THEN MOVING NEWD OVERNIGHT. ALSO WW33 IS GONE. PREV DISCN... BUSY DAY WITH LINE OF STRONG TO SEVERE STORMS CURRENTLY MOVING THROUGH CWA. THIS IS ASSOCIATED WITH MCV PASSING JUST TO OUR NORTH AND GOOD INFLOW INTO THE SOUTH. RELIED HEAVILY ON THE HRRR FOR TIMING OF THE LINE...WHICH IS MOVING ESE AROUND 40KTS. THINGS BECOME A BIT MORE UNCERTAIN TONIGHT...AS CONVECTION WILL BE LINGERING AROUND A WEAK BOUNDARY THAT SHOULD BE NEAR OUR SOUTHERN CWA BORDER. HRRR SHOWING TWO SEPARATE COMPLEXES MOVING ALONG THIS BOUNDARY THIS EVENING INTO TONIGHT. GENERALLY HAVE GOTTEN AROUND A HALF AN INCH IN TODAYS LINE OF CONVECTION...AND COULD GET ANOTHER HALF TO ONE INCH OVERNIGHT. BELIEVE IT WOULD TAKE AROUND 1.5 INCHES IN 3 HOURS TO START CREATING LOCAL PROBLEMS. THIS BOUNDARY WILL SLOWLY LIFT NORTH AS A WARM FRONT THURSDAY MORNING WITH SHOWERS AND T-STORMS. IN THE UNSTABLE WARM SECTOR...COULD AGAIN SEE STRONG TO SEVERE STORMS APPROACH FROM THE WEST THURSDAY AFTERNOON. ONLY MINIMAL CHANGES MADE TO TEMPERATURE FORECAST THROUGH THE PERIOD...AS EXISTING FORECAST LOOKED DECENT. && .SHORT TERM /TONIGHT THROUGH SATURDAY/... MODELS ARE IN GOOD AGREEMENT WITH THE STRONG COLD FRONT THAT MOVES ACROSS LATE THURSDAY NIGHT AND FRIDAY MORNING. LOTS OF JUICE AND GOOD DYNAMICS WILL BRING A BAND OF SHOWERS AND STRONG THUNDERSTORMS ALONG AND AHEAD OF THE FRONT. SHOWERS AND STORMS END FROM WEST TO EAST DURING FRIDAY...WITH THE FRONT EXITING THE MOUNTAINS BY LATER IN THE AFTERNOON. HIGH PRESSURE BUILDS IN FROM THE WEST FOR A DRY BUT COOLER START TO THE WEEKEND. ABOVE NORMAL TEMPERATURES FRIDAY AHEAD OF THE FRONT WILL LOWER TO NEAR OR SLIGHTLY BELOW NORMAL LEVELS BEHIND THE FRONT. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... NO SIGNIFICANT CHANGES WERE MADE TO THE EXTENDED PERIOD. WEEKEND STARTS OUT WARM AND DRY...AND HIGH PRESSURE...SURFACE AND ALOFT BUILDS IN. AN ACTIVE AND STORMY WEEK THEN TAKES HOLD NEXT WEEK...AS ANOTHER FRONTAL BOUNDARY...STALLS OUT ACROSS THE AREA BRIEFLY...BEFORE LIFTING BACK NORTH AS A WARM FRONT BY TUESDAY...WITH LOW PRESSURE MOVING NORTHEAST OUT OF THE SOUTHERN PLAINS TOWARDS THE OHIO VALLEY. THIS WILL PROVIDE THE SET UP FOR WARM...AND HUMID WEATHER ACROSS THE AREA...ALONG WITH CHANCES FOR THUNDERSTORMS IN THE INCREASINGLY MOIST AND UNSTABLE ATMOSPHERE. FOR NOW...BROAD BRUSHED POPS IN THE EXTENDED...WITH A DIURNAL TREND TO CONVECTION/HIGHER POPS. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... SCATTERED SHOWERS AND THUNDERSTORMS WILL REMAIN A POSSIBILITY THROUGH THE PERIOD...WITH STRONGER STORMS PROVIDING IFR RESTRICTIONS. SOME MVFR FOG IS POSSIBLE EARLY THIS MORNING IN AREAS RECENTLY RECEIVING RAINFALL. OUTSIDE OF THE PRECIPITATION...MOSTLY VFR CLOUDS CAN BE EXPECTED. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY... FORECAST CONFIDENCE: LOW. ALTERNATE SCENARIOS: TIMING AND RESTRICTIONS IN SHOWERS/STORMS COULD VARY. UNCERTAIN ON POST-RAIN FOG FORMATION EARLY THIS MORNING. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE THU 04/09/15 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY M M H H H H H M H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 06Z FRIDAY... BRIEF IFR POSSIBLE IN SHOWERS AND/OR THUNDERSTORMS LATE THURSDAY NIGHT AND INTO FRIDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FLASH FLOOD WATCH UNTIL 11 AM EDT THIS MORNING FOR WVZ005>011- 013>017-019-020-024>026-031. OH...FLASH FLOOD WATCH UNTIL 11 AM EDT THIS MORNING FOR OHZ066-067- 075-076-083>087. KY...FLASH FLOOD WATCH UNTIL 11 AM EDT THIS MORNING FOR KYZ101>103- 105. VA...NONE. && $$ SYNOPSIS...TRM/JMV/MZ/SL NEAR TERM...TRM/MZ SHORT TERM...JMV LONG TERM...SL AVIATION...RPY
AREA FORECAST DISCUSSION
NWS PORTLAND
846 AM PDT THU APR 9 2015 .SYNOPSIS...HIGH PRESSURE OVER THE REGION WILL LEAD TO MAINLY DRY CONDITIONS TODAY WITH PERHAPS A SPOTTY SHOWER DEVELOPING OVER THE HIGHER CASCADE TERRAIN IN THE AFTERNOON. FRIDAY WILL LIKELY REMAIN DRY DURING THE DAY FOR MOST OF THE REGION...BUT CLOUDS AND RAIN WILL SPREAD INTO THE REGION DURING THE LATE AFTERNOON AND EVENING HOURS. A COOL SHOWERY PATTERN WILL FOLLOW ON SATURDAY WITH MOST OF THE AREA LOOKING DRY ON SUNDAY AND EARLY MONDAY. ANOTHER COOL AND WET STORM SYSTEM LOOKS TO ARRIVE EARLY NEXT WEEK BEFORE HIGH PRESSURE BRINGS DRIER AND WARMER WEATHER BEGINNING THE MIDDLE OF NEXT WEEK. && .UPDATE...FOG CONTINUES ALONG THE COAST AND IN THE VALLEYS THIS MORNING AND ALTHOUGH PATCHES OF DENSE FOG REMAIN...IMPROVEMENT IN VISIBILITY IS ALREADY BEING SEEN AT SOME AREA OBSERVATION SITES. EXPECT VISIBILITIES TO IMPROVE ACROSS THE BOARD BY LATE MORNING. NO MAJOR UPDATES NEEDED THIS MORNING AS THE FORECAST APPEARS TO BE ON TRACK. TWEAKED NEAR-TERM SKY GRIDS A BIT TO ACCOUNT FOR FOG AND THEN AFTERNOON CLEARING. THE 12Z GFS IS HINTING AT A SLIGHT CHANCE OF SHOWERS IN THE LOWER COLUMBIA AREA THIS AFTERNOON...BUT BOTH HRRR AND RUC KEEP ANY POPS IN THE CASCADES AND MAYBE FOOTHILLS SO WILL KEEP POP/WX FORECAST AS IS THROUGH THIS EVENING. BOWEN .SHORT TERM (PREVIOUS DISCUSSION)...TODAY THROUGH SUNDAY...SATELLITE IMAGERY AND SURFACE OBSERVATIONS INDICATE A FEW PATCHES OF CLOUDS SCATTERED ABOUT THE REGION...WITH MOST HUGGING THE CASCADE FOOTHILLS. SOME PATCHY FOG IS BEGINNING TO DEVELOP IN THE SOUTHERN WILLAMETTE VALLEY...AND EXPECT ADDITIONAL FOG DEVELOPMENT THIS MORNING AS THE LOWER ATMOSPHERE STABILIZES AND SATURATES...PARTICULARLY AROUND EUGENE...CORVALLIS...MCMINNVILLE AND HILLSBORO. A VORT MAX AND WEAK UPPER LEVEL SHORTWAVE TROUGH WILL HANG OVER THE COLUMBIA RIVER BASIN TODAY. THE SOUTH WASHINGTON CASCADES AND NORTH OREGON CASCADES WILL REMAIN CLOSE ENOUGH TO THIS INSTABILITY THAT A SPOTTY LIGHT SHOWER MAY DEVELOP LATER THIS AFTERNOON...BUT THESE SHOULD REMAIN RATHER ISOLATED AND MORE NUISANCE IN NATURE. OTHERWISE...MOST LOCATIONS SHOULD EXPECT MOSTLY SUNNY SKIES AND TEMPERATURES RISING SEVERAL DEGREES ABOVE NORMAL ONCE THE FOG BURNS OFF MID TO LATE MORNING. FRIDAY LOOKS LARGELY DRY ACROSS THE AREA BEFORE A COLD FRONT PUSHES RAIN INTO OUR NORTHWEST COAST DURING THE LATE AFTERNOON HOURS. RAIN WILL LIKELY PUSH INLAND DURING THE LATE EVENING AND OVERNIGHT HOURS. THE MAIN UPPER LEVEL SUPPORT AND DEEPER INSTABILITY WITH THIS FRONT WILL JUST CLIP OUR NORTHERN ZONES LATE FRIDAY NIGHT INTO SATURDAY MORNING SO THERE IS SOME CONCERN THE CURRENT QPF FORECAST MAY BE A BIT TOO HIGH ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. SUFFICIENT INSTABILITY ON SATURDAY SHOULD LEAD TO ADDITIONAL SHOWERS DEVELOPING OVER THE INTERIOR DURING THE AFTERNOON AND EARLY EVENING HOURS BEFORE THE ATMOSPHERE STABILIZES AND PRECIPITATIONS CHANCES RAPIDLY DECREASE SATURDAY NIGHT. IT APPEARS THE INSTABILITY WILL BE SHALLOW ENOUGH THAT THUNDERSTORMS DO NOT APPEAR LIKELY ON SATURDAY EVEN ACROSS THE FAR NORTH. MODELS CONTINUE TO TREND TOWARDS THE IDEA THAT SUNDAY WILL END UP LARGELY DRY ACROSS MOST OF THE FORECAST AREA SO POPS WERE NUDGED DOWNWARD DURING THIS PERIOD...ESPECIALLY ACROSS OUR SOUTHERN ZONES. A WEAK LOW LEVEL TROUGH MAY PUSH INTO WESTERN WASHINGTON DURING THIS PERIOD AND BRING A FEW LIGHT RAIN SHOWERS TO EXTREME NORTHWEST OREGON AND SOUTHWEST WASHINGTON COASTAL AND COAST RANGE ZONES SO CHANCE POPS WERE MAINTAINED ACROSS THESE ZONES DURING THIS PERIOD. /NEUMAN .LONG TERM...SUNDAY NIGHT THROUGH WEDNESDAY...MODELS SEEM TO BE CONVERGING ON THE IDEA THAT A LARGE SHORTWAVE TROUGH WILL SWING EASTWARD OUT OF THE GULF OF ALASKA AND IMPACT THE PACIFIC NORTHWEST EARLY NEXT WEEK. MAINTAINED CHANCE POPS ON MONDAY DUE TO UNCERTAINTY IN TIMING...BUT MODELS SEEM TO BE TRENDING TOWARDS RAIN ARRIVING LATE MONDAY. DEEP POST FRONTAL INSTABILITY...STRONG ONSHORE FLOW AND SNOW LEVELS LOWERING INTO THE 3KFT RANGE MAY LEAD TO HIGHLIGHT WORTHY SNOW IN THE CASCADES WITH THIS EVENT. LEFT THUNDER OUT OF THE FORECAST FOR TUESDAY FOR NOW DUE TO THE UNCERTAINTY IN THE SYNOPTIC SCALE PATTERN...BUT IF CONFIDENCE GROWS THE AFOREMENTIONED PATTERN WILL COME TO FRUITION...IT WILL ALMOST CERTAINLY NEED TO BE ADDED IN COMING SHIFTS. MODELS SEEM TO BE TRENDING TOWARDS DECENT SHORTWAVE RIDGING BUILDING INTO THE PACIFIC NORTHWEST WEDNESDAY AND BEYOND SO TEMPERATURES WERE NUDGED UPWARDS AND POPS AND SKY COVER WERE TRENDED DOWN. /NEUMAN && .AVIATION...HIGH PRESSURE OVER THE AREA HAS ALLOWED FOG TO DEVELOP IN THE WILLAMETTE VALLEY AND ALONG THE COAST. FOG SHOULD LIFT TO LOW STRATUS IMPROVING VIS BY AROUND 16-17Z. CONDITIONS SHOULD IMPROVE TO VFR BY 18-20Z. WINDS HAVE TURNED OFFSHORE ALONG THE COAST...WHICH WILL HELP CLEAR THESE SITES TO VFR BY 18Z AS WELL. VFR CONDITIONS TO PERSIST THIS AFTERNOON. WE MAY SEE SOME VALLEY FOG DEVELOP TONIGHT INLAND...BUT THIS SHOULD CLEAR OUT EARLY TOMORROW MORNING AS WINDS START TO INCREASE OUT OF THE SOUTH AHEAD OF OUR NEXT FRONT WHICH MOVES THROUGH TOMORROW EVENING. KPDX AND APPROACHES...IFR/LIFR CONDITIONS THIS MORNING SHOULD START TO IMPROVE AS FOG LIFTS TO LOW STRATUS BY 16Z. STRATUS SHOULD BURN OFF RAPIDLY...FURTHER IMPROVING CONDITIONS TO VFR BY 18Z. -MCCOY && .MARINE...HIGH PRESSURE OVER THE REGION IS KEEPING SEAS DOWN AROUND 3 FT WITH WIND BELOW 10 KTS TODAY. FRONTAL SYSTEM APPROACHING THE WATERS WILL BACK WINDS TO THE SOUTHWEST BY FRIDAY MORNING AND START TO RAMP UP WINDS AND BUILD SEAS THROUGH THE DAY FRIDAY. A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED FOR WINDS AND SEAS ON FRIDAY AFTERNOON...AS WINDS ARE EXPECTED TO PEAK AHEAD OF THE FRONT IN THE AFTERNOON/EVENING HOURS AROUND 20 TO 25 KTS WITH GUSTS TO 30 KTS. WINDS STAY UP AROUND 15 TO 25 KTS BEHIND THE FRONT...FINALLY STARTING TO DECREASE SATURDAY EVENING. SEAS WITH THIS SYSTEM BUILD TO AROUND 10 TO 12 FT FRIDAY AFTERNOON/EVENING AS WELL...AND FALL TO AROUND 8 TO 10 FT BY SATURDAY MORNING. THE TIME PERIOD WITH SEAS BELOW 10 FT WILL LIKELY ONLY LAST UNTIL SATURDAY EVENING...AND SEAS IN THE OUTER WATERS MAY NEVER DROP BELOW 10 FT. A 10 TO 11 FT SWELL TRAIN MOVES INTO THE WATERS SATURDAY EVENING...BRINGING SEAS UP ABOVE 10 FT THROUGH AT LEAST MONDAY MORNING. ANOTHER FRONT IS EXPECTED TO MOVE THROUGH SOMETIME EARLY NEXT WEEK. -MCCOY && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...NONE. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
412 PM EDT THU APR 9 2015 .SYNOPSIS... STRONG HIGH PRESSURE RIDGING SOUTHWEST INTO THE STATE FROM THE CANADIAN MARITIMES WILL CONTINUE TO KEEP MOIST AND COOL CONDITIONS OVER THE REGION THROUGH TONIGHT. LOW PRESSURE WILL MOVE THROUGH THE GREAT LAKES LATE TONIGHT AND FRIDAY...DRAGGING A COLD FRONT ACROSS PENNSYLVANIA FRIDAY. MUCH COOLER CONDITIONS WILL FOLLOW FOR SATURDAY. TEMPERATURES WILL MODERATE BACK TO MILDER VALUES NEXT WEEK. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... MOST OF CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME BETWEEN STRONG-COLD HIGH PRESSURE OVER THE CANADIAN MARITIMES AND A NEARLY STATIONARY FRONTAL SYSTEM TO OUR WEST AND SOUTH. WIDESPREAD LOW CLOUDS WILL PERSIST INTO THE OVERNIGHT...WITH THE EXCEPTION BEING THE FAR WESTERN STRIPE OF ZONES WHERE SOME MIXING HAS ALLOWED FOR PARTIAL SUNSHINE TO DEVELOP. THIS WILL BE REPLACED BY UPSTREAM CLOUDINESS BEFORE TOO LONG AS SHOWERS CONTINUE TO MOVE OUT OF THE OHIO VALLEY. LIFTED INDEX PROGS INDICATE THAT ALL OF CENTRAL PA WILL REMAIN STRONGLY DAMMED. HOWEVER...SHOWERS AND THUNDERSTORMS ARE CURRENTLY MOVING THROUGH EASTERN OHIO AND THE HRRR TIMES THEM INTO MY WESTERN ZONES BETWEEN ABOUT 5 AND 8 PM. WHETHER WIDESPREAD THUNDER MANAGES TO SURVIVE THE TREK INTO THE STABLE AIRMASS REMAINS TO BE SEEN BUT I HAVE USED THE HRRR TO BRING A PERIOD OF RAIN ACROSS MOST OF MY FCST AREA THIS EVENING THROUGH AROUND MIDNIGHT...WITH STILL A GOOD CHANCE OF ADDITIONAL SHOWERS THROUGH MORNING AHEAD OF THE APPROACHING FRONT. OVERNIGHT LOWS FROM NEAR 40 EAST TO AROUND 50 IN THE WEST WILL BE ANYWHERE FROM ABOUT 5 TO AS MUCH AS 20 DEGREES ABOVE NORMAL. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... OPERATIONAL MODELS ARE IN GOOD AGREEMENT WITH HAVING THE COLD FRONT PRETTY MUCH BISECTING THE FCST AREA BY EARLY AFTERNOON. THE GEFS DEVELOPS SLIGHTLY MORE INSTABILITY THAN DOES THE SREF...BUT IF EITHER MODEL FAVORS AN AREA FOR SEVERE STORMS TOMORROW IT WOULD BE OVER SERN PA DURING THE AFTERNOON AS THE FRONT PROGRESSES EAST. AS IS OFTEN THE CASE IN PA...THE AMOUNT OF CLOUDCOVER WILL HAVE MUCH TO SAY ABOUT THE SEVERE POTENTIAL. SPC DOES HAVE MY FAR SERN ZONES OUTLOOKED FOR A SLIGHT RISK WHICH AT THIS RANGE LOOKS REASONABLE. TEMPS FRIDAY WILL REBOUND NICELY...REACHING THE LOW-MID 60S ACROSS THE NRN AND WRN MTNS...AND LOW-MID 70S IN THE SE. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... COLD FRONT EXITING TO THE SOUTHEAST BY FRI NIGHT...WILL BE FOLLOWED BY A RATHER STRONG SMALL UPPER LEVEL TROUGH FRIDAY NIGHT INTO SAT. DYNAMICS LOOK STRONG ENOUGH TO MAINTAIN CHANCE FOR SHOWERS...TAPERING BACK TO SPRINKLES ON SAT AS THEY MOVE AWAY. ANY SHOWERS WILL BE ON THE LIGHT SIDE. BREEZY WITH A QUICK SHOT OF COOLER AIR ON SAT...THEN WARMER AIR RETURNS ON SUNDAY INTO MONDAY AS RIDGE BUILDS IN. MENTION OF POPS RETURNS LATE MONDAY INTO TUE AS ANOTHER FRONT TRACKS ACROSS THE REGION. AGAIN...PRECIP AMOUNTS LOOK TO REMAIN ON THE LIGHT SIDE. SHARP RIDGE BUILDS IN FOR MID/LATE WEEK AS SOUTHERLY WINDS BRING A PERIOD OF MILD WEATHER. WEAKENING SYSTEM OVER THE UPPER MIDWEST MAY BRING SHOWERY WEATHER BACK INTO PA FOR THU/FRI. && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... PLENTIFUL LOW LEVEL MOISTURE WILL KEEP WIDESPREAD IFR-MVFR CONDITIONS ACROSS MOST OF THE THE REGION INTO THE OVERNIGHT. SOME IMPROVEMENT HAS MANAGED TO CREEP INTO MY FAR WESTERN TERMINALS...BUT THIS WILL LIKELY NOT BE LONG LIVED AS SHOWERS AND THUNDERSTORMS ENTERING WESTERN PA PROGRESS EASTWARD THROUGH THE LATE AFTERNOON AND EVENING. LLWS IS POSSIBLE THIS EVENING AS SFC WINDS REMAIN OUT OF THE SOUTHEAST...AND WINDS JUST ABOVE THE SURFACE INCREASE OUT OF THE SOUTHWEST AT 30-50KT. A COLD FRONT WILL SWEEP ACROSS THE REGION FRIDAY...CLEARING THE LOWER SUSQ VALLEY BY 21-00Z. WINDS SHIFTING TO THE WEST WILL FINALLY SCOUR OUT THE STUBBORN LOW CLOUDS WITH WIDESPREAD VFR CONDITIONS DEVELOPING DURING THE AFTERNOON INTO THE EVENING. ISOLATED STRONG THUNDERSTORMS WILL BE POSSIBLE OVER THE LOWER SUSQ VALLEY WITH THE COLD FRONT FRIDAY AFTERNOON. OUTLOOK... SAT-SUN...VFR. MON...COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS ALONG WITH LOCALLY REDUCED CONDITIONS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...RXR AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
241 PM EDT THU APR 9 2015 .SYNOPSIS... STRONG HIGH PRESSURE RIDGING SOUTHWEST INTO THE STATE FROM THE CANADIAN MARITIMES WILL CONTINUE TO KEEP MOIST AND COOL CONDITIONS OVER THE REGION THROUGH TONIGHT. LOW PRESSURE WILL MOVE THROUGH THE GREAT LAKES LATE TONIGHT AND FRIDAY...DRAGGING A COLD FRONT ACROSS PENNSYLVANIA FRIDAY. MUCH COOLER CONDITIONS WILL FOLLOW FOR SATURDAY. TEMPERATURES WILL MODERATE BACK TO MILDER VALUES NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... MOST OF CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME BETWEEN STRONG-COLD HIGH PRESSURE OVER THE CANADIAN MARITIMES AND A NEARLY STATIONARY FRONTAL SYSTEM TO OUR WEST AND SOUTH. WIDESPREAD LOW CLOUDS WILL PERSIST INTO THE OVERNIGHT...WITH THE EXCEPTION BEING THE FAR WESTERN STRIPE OF ZONES WHERE SOME MIXING HAS ALLOWED FOR PARTIAL SUNSHINE TO DEVELOP. THIS WILL BE REPLACED BY UPSTREAM CLOUDINESS BEFORE TOO LONG AS SHOWERS CONTINUE TO MOVE OUT OF THE OHIO VALLEY. LIFTED INDEX PROGS INDICATE THAT ALL OF CENTRAL PA WILL REMAIN STRONGLY DAMMED. HOWEVER...SHOWERS AND THUNDERSTORMS ARE CURRENTLY MOVING THROUGH EASTERN OHIO AND THE HRRR TIMES THEM INTO MY WESTERN ZONES BETWEEN ABOUT 5 AND 8 PM. WHETHER WIDESPREAD THUNDER MANAGES TO SURVIVE THE TREK INTO THE STABLE AIRMASS REMAINS TO BE SEEN BUT I HAVE USED THE HRRR TO BRING A PERIOD OF RAIN ACROSS MOST OF MY FCST AREA THIS EVENING THROUGH AROUND MIDNIGHT...WITH STILL A GOOD CHANCE OF ADDITIONAL SHOWERS THROUGH MORNING AHEAD OF THE APPROACHING FRONT. OVERNIGHT LOWS FROM NEAR 40 EAST TO AROUND 50 IN THE WEST WILL BE ANYWHERE FROM ABOUT 5 TO AS MUCH AS 20 DEGREES ABOVE NORMAL. && .SHORT TERM /FRIDAY/... OPERATIONAL MODELS ARE IN GOOD AGREEMENT WITH HAVING THE COLD FRONT PRETTY MUCH BISECTING THE FCST AREA BY EARLY AFTERNOON. THE GEFS DEVELOPS SLIGHTLY MORE INSTABILITY THAN DOES THE SREF...BUT IF EITHER MODEL FAVORS AN AREA FOR SEVERE STORMS TOMORROW IT WOULD BE OVER SERN PA DURING THE AFTERNOON AS THE FRONT PROGRESSES EAST. AS IS OFTEN THE CASE IN PA...THE AMOUNT OF CLOUDCOVER WILL HAVE MUCH TO SAY ABOUT THE SEVERE POTENTIAL. SPC DOES HAVE MY FAR SERN ZONES OUTLOOKED FOR A SLIGHT RISK WHICH AT THIS RANGE LOOKS REASONABLE. TEMPS FRIDAY WILL REBOUND NICELY...REACHING THE LOW-MID 60S ACROSS THE NRN AND WRN MTNS...AND LOW-MID 70S IN THE SE. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... A RATHER STRONG SMALL UPPER LEVEL TROUGH MOVES ACROSS THE AREA FOR LATE FRIDAY INTO SAT. MAIN THING WAS TO PUT BACK IN A CHC OF SHOWERS FOR LATE FRIDAY NIGHT INTO SATURDAY ACROSS THE FAR NORTH...GIVEN STRONG DYNAMICS WITH A STRONG UPPER LEVEL LOW. PAST EXPERIENCE WITH THIS SITUATION USUALLY LEADS TO SOME SHOWERS. OVERALL...THE WEEKEND LOOKS SIMILAR TO LAST WEEKEND. BREEZY AND COOL ON SAT. WARMER ON SUNDAY. DID UP POPS TO 30 PERCENT FROM LATE MONDAY INTO WED MORNING TO FIT IN WITH OTHERS BETTER. STILL SOME SPREAD ON THE DETAILS. LOOKS LIKE MODELS AND HPC HAVE COLD FRONT MOVING INTO THE AREA ON TUE. FRONT MAY NOT CLEAR TO WED. DID UP TEMPERATURES SOME TOO. && .AVIATION /17Z THURSDAY THROUGH MONDAY/... PLENTIFUL LOW LEVEL MOISTURE WILL KEEP WIDESPREAD IFR-MVFR CONDITIONS ACROSS MOST OF THE THE REGION INTO THE OVERNIGHT. SOME IMPROVEMENT HAS MANAGED TO CREEP INTO MY FAR WESTERN TERMINALS...BUT THIS WILL LIKELY NOT BE LONG LIVED AS SHOWERS AND THUNDERSTORMS ENTERING WESTERN PA PROGRESS EASTWARD THROUGH THE LATE AFTERNOON AND EVENING. LLWS IS POSSIBLE THIS EVENING AS SFC WINDS REMAIN OUT OF THE SOUTHEAST...AND WINDS JUST ABOVE THE SURFACE INCREASE OUT OF THE SOUTHWEST AT 30-50KT. A COLD FRONT WILL SWEEP ACROSS THE REGION FRIDAY...CLEARING THE LOWER SUSQ VALLEY BY 21-00Z. WINDS SHIFTING TO THE WEST WILL FINALLY SCOUR OUT THE STUBBORN LOW CLOUDS WITH WIDESPREAD VFR CONDITIONS DEVELOPING DURING THE AFTERNOON INTO THE EVENING. ISOLATED STRONG THUNDERSTORMS WILL BE POSSIBLE OVER THE LOWER SUSQ VALLEY WITH THE COLD FRONT FRIDAY AFTERNOON. OUTLOOK... SAT-SUN...VFR. MON...COLD FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS ALONG WITH LOCALLY REDUCED CONDITIONS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LAMBERT/MARTIN AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1033 AM EDT THU APR 9 2015 .SYNOPSIS... STRONG HIGH PRESSURE RIDGING SOUTHWEST INTO THE STATE FROM THE CANADIAN MARITIMES WILL CONTINUE TO KEEP MOIST AND COOL CONDITIONS OVER THE REGION TODAY. LOW PRESSURE WILL MOVE THROUGH THE GREAT LAKES LATE TONIGHT AND FRIDAY...DRAGGING A COLD FRONT ACROSS PENNSYLVANIA FRIDAY. MUCH COOLER CONDITIONS WILL FOLLOW FOR SATURDAY. TEMPERATURES WILL MODERATE BACK TO MILDER VALUES NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME BETWEEN STRONG-COLD HIGH PRESSURE OVER THE CANADIAN MARITIMES AND A NEARLY STATIONARY FRONTAL SYSTEM TO OUR WEST AND SOUTH. WIDESPREAD LOW CLOUDS AND RIDGE SHROUDING FOG WILL PERSIST THIS MORNING...BEFORE SLOWLY LIFTING AS SFC TEMPS MODERATE A BIT THIS AFTERNOON. SHOWERS OVER WESTERN PA MAY SNEAK INTO OUR FAR WESTERN LAYER OF COUNTIES BEFORE DIMINISHING IN THE INCREASINGLY STABLE AIRMASS. LIFTED INDEX PROGS INDICATE THAT ALL OF CENTRAL PA WILL REMAIN STRONGLY DAMMED. HOWEVER...SHOWERS FORMING IN THE UNSTABLE AIRMASS OVER THE OHIO VALLEY ARE MADE TO SURVIVE THE TREK INTO CENTRAL PA LATER THIS AFTERNOON AND THIS EVENING AS THE HRRR SHOWS AN EROSION OF THE WESTERN EDGE OF THE STABLE COOL-AIR-DAMMING. CAN`T RULE OUT LATE DAY-EARLY EVENING SEVERE THREAT OVER WESTERN PORTIONS OF THE SOMERSET/WARREN COUNTIES ON THE EDGE OF THE INSTABILITY NEAR OUR STATIONARY BOUNDARY. HIGHS TODAY SHOULD BE MOSTLY IN THE 40S. HOWEVER...AREAS ALONG AND WEST OF THE RT 219 CORRIDOR WILL LIKELY GET INTO THE 50S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... CLUSTERS/BKN LINE OF STRONG TO POTENTIALLY SEVERE TSRA ACROSS THE OHIO VALLEY THIS AFTERNOON/EVENING WILL HEAD INTO INCREASINGLY STABLE LLVL CONDITIONS ACROSS CENTRAL AND ERN PENN AND GRADUALLY WEAKEN TONIGHT. STILL...A LARGE AREA AND NEARLY OFF THE CHART/ANOMALOUSLY STRONG /PLUS 5-6 SIGMA/ 850 MB MOISTURE FLUX /SHOWN ON THE 00Z GEFS AND 03Z SREF/ WILL SLIDE NORTHEAST ACROSS MUCH OF CENTRAL AND NWRN PENN. THIS WILL LEAD TO AREAS OF MODERATE...TO BRIEFLY HEAVY SHRA /THOUGH MAINLY LIMITED TO THE NW HALF OF PENN/. 12 TO 24 HOUR RAINFALL TONIGHT THROUGH FRIDAY /AS DEPICTED BY OPERATIONAL MODELS AND ENSEMBLES/ OF JUST 0.25-0.50 OF AN INCH ACROSS MAINLY THE NW HALF OF PENN WILL BE SURPRISINGLY LIGHT GIVEN SUCH STRONG LLVL MOISTURE FLUX. HOWEVER...THE KEY TO THE LIGHTER THAN EXPECTED QPF APPEARS TO BE LINKED TO THE LACK OF FAVORABLE JET DYNAMICS/LIFT AS THE RIGHT EXIT REGION OF A 100 KT UPPER JET SLIDES NE ACROSS LAKE ERIE AND NW PENN LATE TONIGHT AND FRIDAY MORNING. SPC GREATLY TRIMMED BACK THEIR DAY 1 CONVECTIVE OUTLOOK AREA PREVIOUS ERN EXTENT OF THE SLIGHT RISK AND ENHANCED THREAT AREAS OVER WESTERN PENN HAVE BEEN PULLED BACK WELL INTO CENTRAL AND WESTERN OHIO. ERN EDGE OF THE MARGINAL THREAT AREA NIPS OUR FAR WESTERN ZONES FOR THIS EVENING AND TONIGHT. APPROX 990 MB SFC LOW OVER THE UPPER GLAKES AT 12 FRIDAY WILL PUSH ITS SWD TRAILING COLD FRONT THROUGH CENTRAL PENN DURING THE LATE MORNING AND AFTERNOON HOURS FRIDAY. THE TIMING OF THIS CFROPA FAVORS ANY CHC OF STRONG TO POTENTIALLY ISOLATED SVR TSRA BEING LIMITED TO PRIMARILY THE MIDDLE AND LOWER SUSQ VALLEY AFTER 18Z FRIDAY. SPC MARGINAL AND SLIGHT RISK AREAS FOR DAY 2 COVER THE SE THIRD OF THE CWA. TEMPS FRIDAY WILL REBOUND NICELY...REACHING THE LOW-MID 60S ACROSS THE NRN AND WRN MTNS...AND LOW-MID 70S IN THE SE /WHERE THE 03Z SREF SHOWS ABOUT A 30-40 PERCENT PROBABILITY OF CAPE EXCEEDING 1000 J/KG/. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... A RATHER STRONG SMALL UPPER LEVEL TROUGH MOVES ACROSS THE AREA FOR LATE FRIDAY INTO SAT. MAIN THING WAS TO PUT BACK IN A CHC OF SHOWERS FOR LATE FRIDAY NIGHT INTO SATURDAY ACROSS THE FAR NORTH...GIVEN STRONG DYNAMICS WITH A STRONG UPPER LEVEL LOW. PAST EXPERIENCE WITH THIS SITUATION USUALLY LEADS TO SOME SHOWERS. OVERALL...THE WEEKEND LOOKS SIMILAR TO LAST WEEKEND. BREEZY AND COOL ON SAT. WARMER ON SUNDAY. DID UP POPS TO 30 PERCENT FROM LATE MONDAY INTO WED MORNING TO FIT IN WITH OTHERS BETTER. STILL SOME SPREAD ON THE DETAILS. LOOKS LIKE MODELS AND HPC HAVE COLD FRONT MOVING INTO THE AREA ON TUE. FRONT MAY NOT CLEAR TO WED. DID UP TEMPERATURES SOME TOO. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... PLENTIFUL LOW LEVEL MOISTURE WILL KEEP WIDESPREAD IFR CONDITIONS ACROSS THE REGION THIS MORNING. THERE COULD BE SOME SLOW IMPROVEMENT THIS AFTERNOON...BUT ALL TERMINALS WILL MAINTAIN CEILINGS IN THE 500-1500` RANGE AT BEST. JOHNSTOWN MAY STAND THE BEST CHANCE OF BRIEFLY GOING VFR BEING CLOSE TO THE WARM FRONT STACKED UP OVER THE ALLEGHENIES...BUT CONFIDENCE IN SIG IMPROVEMENT IS NOT HIGH. WIDESPREAD IFR/MVFR WILL CONTINUE OVERNIGHT UNTIL THE COLD FRONT PASSES DURING THE DAY FRIDAY. LLWS IS POSSIBLE BEHIND THE LINE WITH WITH SFC WINDS REMAINING OUT OF THE SOUTHEAST...AND WINDS BETWEEN 1500 TO 2KFT AT 40KTS POSSIBLE TONIGHT BEGINNING IN THE WEST AROUND 07Z TO 11Z AT LNS. OUTLOOK... FRI...A COLD FRONT WILL BRING MORE REDUCTIONS WITH RAIN SHOWERS AND POSSIBLE THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON. SAT-MON...VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/LAMBERT NEAR TERM...LA CORTE/LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT/MARTIN AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
258 AM EDT THU APR 9 2015 .SYNOPSIS... A NEARLY STATIONARY FRONT JUST SOUTH OF PENNSYLVANIA AND STRONG HIGH PRESSURE OVER QUEBEC WILL COMBINE TO KEEP MOIST AND COOL CONDITIONS OVER THE REGION THROUGH TODAY. DEEPENING LOW PRESSURE WILL MOVE NORTHEAST FROM THE CENTRAL PLAINS AND CROSS THE UPPER GREAT LAKES LATE TONIGHT AND FRIDAY...PUSHING ITS SOUTHWARD TRAILING COLD FRONT ACROSS PENNSYLVANIA FRIDAY. AFTER A WARM DAY ON FRIDAY...MUCH COOLER CONDITIONS WILL FOLLOW FOR SATURDAY. TEMPERATURES WILL MODERATE BACK TO MILDER VALUES NEXT WEEK. THERE COULD BE A SHOWER FROM TIME TO TIME NEXT WEEK. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME BETWEEN STRONG-COLD HIGH PRESSURE /RIDGING SWWD FROM THE CANADIAN MARITIMES/ AND LOW PRESSURE OVER CENTRAL KANSAS. REGIONAL RADAR LOOP AT 05Z SHOWS A SMALL MCS/WEAKENING CLUSTER OF SHRA/TSRA SLIDING ACROSS SOUTHERN PORTIONS OF THE LAUREL HIGHLANDS. THIS CONVECTIVE FEATURE WILL CONTINUE TO STEADILY WEAKEN AS IT RIDES EAST AND INTO THE DEEPER LLVL COOL AIR DAMMING REGIME OVER...AND TO THE EAST OF THE ALLEGHENIES. BASED ON RADAR TRENDS AND LATEST HRRR OUTPUT...WILL CARRY LIKELY TO CATEGORICAL POPS THROUGH 08Z ACROSS THE REGION NEAR AND TO THE SOUTH OF THE PA TURNPIKE IN SCENT PENN...WITH A VERY SHARP GRADIENT TOWARD LITTLE OR NO RAINFALL NORTH OF THE TURNPIKE. RAINFALL AMOUNTS COULD TOTAL A FEW TENTHS OF AN INCH ACROSS SOUTHERN SOMERSET COUNTY WITH DECREASING AMTS NORTH AND EAST...WHERE OVERCAST SKIES...RIDGE SHROUDING FOG...AND PATCHY LIGHT DRIZZLE WILL PREVAIL THROUGH THE MID MORNING HOURS. SWRN SECTIONS OF THE CWA WILL REMAIN SUSCEPTIBLE TO ADDITIONAL SHOWERS TOWARD DAWN ASSOC WITH INCREASING ISENTROPIC LIFT IN ADVANCE OF DEVELOPING STORM SYSTEM/SOUTHERLY LL JET OVR THE MIDWEST. BLEND OF LATEST GUIDANCE KEEPS TEMPS NEARLY STEADY OVERNIGHT WITH LOWS IN THE UPPER 30S TO LOW 40S. && .SHORT TERM /8 AM THIS MORNING THROUGH 6 PM FRIDAY/... MORE OVERCAST AND COOL CONDITIONS ARE ON TAP FOR TODAY...AS CENTRAL PA REMAINS IN CAD REGIME. THERE WILL BE AN INCREASING CHC OF SHOWERS...ESP OVR THE NW MTNS BY AFTN...AS SWRLY LL JET ASSOC WITH DEVELOPING LOW OVR THE MIDWEST APPROACHES. GEFS 8H MFLUX VALUES SKYROCKET TO 5SD ABV NORMAL ACROSS NW PA BY 00Z THU. BASED ON LATEST ENSEMBLE OUTPUT...WILL MAINTAIN CATEGORICAL POPS ACROSS THE NW MTNS...WITH A GRADUAL DECREASE TO CHC POPS ACROSS THE LOWER SUSQ VALLEY. LIFTED INDEX PROGS INDICATE THAT ALL OF CENTRAL PA WILL REMAIN STRONGLY DAMMED. HOWEVER...CAN/T RULE OUT LATE DAY SVR WX THREAT OVR WESTERN PORTIONS OF THE SOMERSET/WARREN COUNTIES...IN CLOSE PROXIMITY TO STATIONARY FRONT AND EASTERN EDGE OF MODERATELY HIGH SFC BASED CAPE. AREAS WEST OF THIS BOUNDARY SHOULD BE PRIMED FOR SVR WX WITH MODERATE CAPE AND STRONG SHEAR IN THE 0-6KM AND 0-1KM LAYERS. HIGHS TODAY SHOULD BE MOSTLY IN THE 40S. HOWEVER...AREAS ALONG AND WEST OF THE RT 219 CORRIDOR WILL LIKELY GET INTO THE 50S. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... NOT A LOT OF CHANGE TO PACKAGE FROM RECENT DAYS. MAIN CHANGE WAS TO UP TEMPERATURES THU NIGHT...GIVEN THAT 850 MB FRONT IS WELL NORTH OF THE AREA...AND VERY STRONG LOW LEVEL FLOW IS EXPECTED ACROSS THE AREA. ALSO DID UP TEMPERATURES ON FRIDAY...GIVEN NEW GUIDANCE AND THAT 850 MB FRONT IS NORTH OF THE AREA. HAVE INCREASING CONCERN FOR AT LEAST A FEW STRONG STORMS ACROSS THE AREA. EARLY ON...FAR WEST MAY SEE ONE...GIVEN STRONGER WIND FIELDS TO THE WEST. LATER ON...TEMPERATURES IN THE 70 TO 75 DEGREE RANGE...WITH DEWPTS IN THE 50S...MAY LEAD SOME STORMS LATER IN THE AFT...EVEN WITH NOT THE BEST HEIGHT FALLS. ONE ONLY HAS TO LOOK OVER COLD LAKE ERIE. CONVECTION FORMED ALONG THE LAKE SHORE...WITH JUST SOME MINOR AMTS OF HEATING THIS AFT. ANYWAY...DID LOWER TEMPS FOR FRIDAY NIGHT INTO SAT. A RATHER STRONG SMALL UPPER LEVEL TROUGH MOVES ACROSS THE AREA FOR LATE FRIDAY INTO SAT. MAIN THING WAS TO PUT BACK IN A CHC OF SHOWERS FOR LATE FRIDAY NIGHT INTO SATURDAY ACROSS THE FAR NORTH...GIVEN STRONG DYNAMICS WITH A STRONG UPPER LEVEL LOW. PAST EXPERIENCE WITH THIS SITUATION USUALLY LEADS TO SOME SHOWERS. OVERALL...THE WEEKEND LOOKS SIMILAR TO LAST WEEKEND. BREEZY AND COOL ON SAT. WARMER ON SUNDAY. DID UP POPS TO 30 PERCENT FROM LATE MONDAY INTO WED MORNING TO FIT IN WITH OTHERS BETTER. STILL SOME SPREAD ON THE DETAILS. LOOKS LIKE MODELS AND HPC HAVE COLD FRONT MOVING INTO THE AREA ON TUE. FRONT MAY NOT CLEAR TO WED. DID UP TEMPERATURES SOME TOO. && .AVIATION /07Z THURSDAY THROUGH MONDAY/... WIDESPREAD IFR/MVFR WILL CONTINUE NORTH OF THE FRONTAL SYSTEM THAT IS STALLED SOUTH OF PA. THIS STATIONARY FRONTAL BOUNDARY WILL KEEP LOW LEVEL MOISTURE LOCKED IN PLACE TONIGHT AND THURSDAY. LOW CIGS...AREAS OF FOG AND DRIZZLE ALONG WITH ISOLATED SHOWERS WILL BE THE RULE. THERE HAVE BEEN SLIGHT BREAKS IN SOME OF THE MVFR TO IFR CIGS AND VSBYS...THOUGH THESE WILL BE THE EXCEPTION AND NOT THE RULE. WINDS WILL REMAIN FROM THE EAST OR SOUTHEAST AT 5-10 MPH WITH MAY TAF SITES GOING CALM OVERNIGHT. AS THURSDAY CONTINUES THE LOW STRATOCU WILL SLOWLY BREAK UP...WITH IFR CIGS INCREASING TO MVFR TO PERHAPS A BRIEF PERIOD OF VFR...BEFORE DROPPING DOWN THURSDAY EVENING. OUTLOOK... FRI...A COLD FRONT WILL BRING MORE REDUCTIONS WITH RAIN SHOWERS AND POSSIBLE THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON. SAT-MON...VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...FITZGERALD/LAMBERT SHORT TERM...FITZGERALD/LA CORTE/LAMBERT LONG TERM...MARTIN AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
136 AM EDT THU APR 9 2015 .SYNOPSIS... A NEARLY STATIONARY FRONT JUST SOUTH OF PENNSYLVANIA AND STRONG HIGH PRESSURE OVER QUEBEC WILL COMBINE TO KEEP MOIST AND COOL CONDITIONS OVER THE REGION THROUGH TODAY. DEEPENING LOW PRESSURE WILL MOVE NORTHEAST FROM THE CENTRAL PLAINS AND CROSS THE UPPER GREAT LAKES LATE TONIGHT AND FRIDAY...PUSHING ITS SOUTHWARD TRAILING COLD FRONT ACROSS PENNSYLVANIA FRIDAY. AFTER A WARM DAY ON FRIDAY...MUCH COOLER CONDITIONS WILL FOLLOW FOR SATURDAY. TEMPERATURES WILL MODERATE BACK TO MILDER VALUES NEXT WEEK. THERE COULD BE A SHOWER FROM TIME TO TIME NEXT WEEK. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... CENTRAL PA REMAINS FIRMLY ENTRENCHED IN A COOL AIR DAMMING REGIME BETWEEN STRONG-COLD HIGH PRESSURE /RIDGING SWWD FROM THE CANADIAN MARITIMES/ AND LOW PRESSURE OVER CENTRAL KANSAS. REGIONAL RADAR LOOP AT 05Z SHOWS A SMALL MCS/WEAKENING CLUSTER OF SHRA/TSRA SLIDING ACROSS SOUTHERN PORTIONS OF THE LAUREL HIGHLANDS. THIS CONVECTIVE FEATURE WILL CONTINUE TO STEADILY WEAKEN AS IT RIDES EAST AND INTO THE DEEPER LLVL COOL AIR DAMMING REGIME OVER...AND TO THE EAST OF THE ALLEGHENIES. BASED ON RADAR TRENDS AND LATEST HRRR OUTPUT...WILL CARRY LIKELY TO CATEGORICAL POPS THROUGH 08Z ACROSS THE REGION NEAR AND TO THE SOUTH OF THE PA TURNPIKE IN SCENT PENN...WITH A VERY SHARP GRADIENT TOWARD LITTLE OR NO RAINFALL NORTH OF THE TURNPIKE. RAINFALL AMOUNTS COULD TOTAL A FEW TENTHS OF AN INCH ACROSS SOUTHERN SOMERSET COUNTY WITH DECREASING AMTS NORTH AND EAST...WHERE OVERCAST SKIES...RIDGE SHROUDING FOG...AND PATCHY LIGHT DRIZZLE WILL PREVAIL THROUGH THE MID MORNING HOURS. SWRN SECTIONS OF THE CWA WILL REMAIN SUSCEPTIBLE TO ADDITIONAL SHOWERS TOWARD DAWN ASSOC WITH INCREASING ISENTROPIC LIFT IN ADVANCE OF DEVELOPING STORM SYSTEM/SOUTHERLY LL JET OVR THE MIDWEST. BLEND OF LATEST GUIDANCE KEEPS TEMPS NEARLY STEADY OVERNIGHT WITH LOWS IN THE UPPER 30S TO LOW 40S. && .SHORT TERM /8 AM THIS MORNING THROUGH 6 PM FRIDAY/... MORE OVERCAST AND COOL CONDITIONS ARE ON TAP FOR TODAY...AS CENTRAL PA REMAINS IN CAD REGIME. THERE WILL BE AN INCREASING CHC OF SHOWERS...ESP OVR THE NW MTNS BY AFTN...AS SWRLY LL JET ASSOC WITH DEVELOPING LOW OVR THE MIDWEST APPROACHES. GEFS 8H MFLUX VALUES SKYROCKET TO 5SD ABV NORMAL ACROSS NW PA BY 00Z THU. BASED ON LATEST ENSEMBLE OUTPUT...WILL MAINTAIN CATEGORICAL POPS ACROSS THE NW MTNS...WITH A GRADUAL DECREASE TO CHC POPS ACROSS THE LOWER SUSQ VALLEY. LIFTED INDEX PROGS INDICATE THAT ALL OF CENTRAL PA WILL REMAIN STRONGLY DAMMED. HOWEVER...CAN/T RULE OUT LATE DAY SVR WX THREAT OVR WESTERN PORTIONS OF THE SOMERSET/WARREN COUNTIES...IN CLOSE PROXIMITY TO STATIONARY FRONT AND EASTERN EDGE OF MODERATELY HIGH SFC BASED CAPE. AREAS WEST OF THIS BOUNDARY SHOULD BE PRIMED FOR SVR WX WITH MODERATE CAPE AND STRONG SHEAR IN THE 0-6KM AND 0-1KM LAYERS. HIGHS TODAY SHOULD BE MOSTLY IN THE 40S. HOWEVER...AREAS ALONG AND WEST OF THE RT 219 CORRIDOR WILL LIKELY GET INTO THE 50S. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... NOT A LOT OF CHANGE TO PACKAGE FROM RECENT DAYS. MAIN CHANGE WAS TO UP TEMPERATURES THU NIGHT...GIVEN THAT 850 MB FRONT IS WELL NORTH OF THE AREA...AND VERY STRONG LOW LEVEL FLOW IS EXPECTED ACROSS THE AREA. ALSO DID UP TEMPERATURES ON FRIDAY...GIVEN NEW GUIDANCE AND THAT 850 MB FRONT IS NORTH OF THE AREA. HAVE INCREASING CONCERN FOR AT LEAST A FEW STRONG STORMS ACROSS THE AREA. EARLY ON...FAR WEST MAY SEE ONE...GIVEN STRONGER WIND FIELDS TO THE WEST. LATER ON...TEMPERATURES IN THE 70 TO 75 DEGREE RANGE...WITH DEWPTS IN THE 50S...MAY LEAD SOME STORMS LATER IN THE AFT...EVEN WITH NOT THE BEST HEIGHT FALLS. ONE ONLY HAS TO LOOK OVER COLD LAKE ERIE. CONVECTION FORMED ALONG THE LAKE SHORE...WITH JUST SOME MINOR AMTS OF HEATING THIS AFT. ANYWAY...DID LOWER TEMPS FOR FRIDAY NIGHT INTO SAT. A RATHER STRONG SMALL UPPER LEVEL TROUGH MOVES ACROSS THE AREA FOR LATE FRIDAY INTO SAT. MAIN THING WAS TO PUT BACK IN A CHC OF SHOWERS FOR LATE FRIDAY NIGHT INTO SATURDAY ACROSS THE FAR NORTH...GIVEN STRONG DYNAMICS WITH A STRONG UPPER LEVEL LOW. PAST EXPERIENCE WITH THIS SITUATION USUALLY LEADS TO SOME SHOWERS. OVERALL...THE WEEKEND LOOKS SIMILAR TO LAST WEEKEND. BREEZY AND COOL ON SAT. WARMER ON SUNDAY. DID UP POPS TO 30 PERCENT FROM LATE MONDAY INTO WED MORNING TO FIT IN WITH OTHERS BETTER. STILL SOME SPREAD ON THE DETAILS. LOOKS LIKE MODELS AND HPC HAVE COLD FRONT MOVING INTO THE AREA ON TUE. FRONT MAY NOT CLEAR TO WED. DID UP TEMPERATURES SOME TOO. && .AVIATION /05Z THURSDAY THROUGH MONDAY/... WIDESPREAD IFR/MVFR WILL CONTINUE NORTH OF THE FRONTAL SYSTEM THAT IS STALLED SOUTH OF PA. THIS STATIONARY FRONTAL BOUNDARY WILL KEEP LOW LEVEL MOISTURE LOCKED IN PLACE TONIGHT AND THURSDAY. LOW CIGS...AREAS OF FOG AND DRIZZLE ALONG WITH ISOLATED SHOWERS WILL BE THE RULE WITH LITTLE IF ANY IMPROVEMENT EXPECTED. WINDS WILL REMAIN FROM THE EAST OR SOUTHEAST AT 5-10 MPH THROUGH THE PERIOD. OUTLOOK... FRI...A COLD FRONT WILL BRING MORE REDUCTIONS WITH RAIN SHOWERS AND POSSIBLE THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON. SAT-MON...VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT/FITZGERALD LONG TERM...MARTIN AVIATION...GARTNER
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
112 AM EDT THU APR 9 2015 .SYNOPSIS... M AND HUMID SOUTHWESTERLY FLOW WILL PERSIST OVER THE REGION THROUGH THE WORK WEEK...KEEPING CONDITIONS UNSETTLED WITH CHANCES FOR SHOWERS AND THUNDERSTORMS EACH DAY. A COLD FRONT IS FORECAST TO CROSS THE REGION BY THE END OF FRIDAY...LIKELY SUPPORTING A BAND OF SHOWER AND THUNDERSTORMS. DRIER WEATHER IS EXPECTED TO RETURN TO THE REGION THIS WEEKEND. && .NEAR TERM /THROUGH TODAY/... 0515 UTC UPDATE...SKY COVER WAS ADJUSTED PER SATELLITE IMAGERY. POPS WERE ADJUSTED PER RADAR TRENDS. WINDS WERE UPDATED FROM THE LATEST MODEL DATA. TEMPERATURES WERE ADJUSTED UP A BIT TODAY AND DOWN A BIT TONIGHT PER THE LATEST MODEL DATA. AS OF 1000 PM...THE LATEST SPC MESOANALYSIS PAGE STILL SHOWS 1000-2000 J/KG OF MUCAPE. A COUPLE OF ISOLD TSTMS HAVE POPPED UP IN THE MIDLANDS...AND THE LAST COUPLE OF HRRR RUNS DO SHOW A FEW MORE CELLS DEVELOPING OVER THE NEXT FEW HOURS SOUTH OF I-85. SO WILL ADD A SLGT CHC BACK IN ACRS THE SOUTHEASTERN ZONES. CANNOT RULE OUT A SEVERE PULSE STORM GIVEN THE CAPE AND 25-30 KTS OF EFFECTIVE SHEAR. OTHERWISE...THE REST OF THE FCST LOOKS ON TRACK. AS OF 730 PM EDT...STILL A CLEAR RADAR ON KGSP...WITH CONVECTIVE ACTIVITY REMAINING WELL TO THE NORTH AND EAST OF THE AREA. HAVE CUT BACK POPS SIGNIFICANTLY WITH THIS UPDATE...LEAVING A SLGT CHC IN FOR THE NRN TIER...IN CASE SOMETHING FIRES TO OUR NORTH AND MOVES IN. TEMPS/SKY/WINDS ARE ON TRACK. AS OF 500 PM EDT...THE ATMOS CONTINUES TO BE RATHER SUPPRESSED ACRS THE CWFA...AS AS UPPER RIDGING DOMINATES. HAVE CUT BACK POP HEADING INTO THE EVENING HOURS...IN LINE WITH THE LAST FEW HRRR RUNS OF SIMULATED REFLECTIVITY. MCS ACTIVITY LOOKS TO REMAIN NORTH OF THE AREA. HOWEVER...ONE CLUSTER OF STORMS OVER CENTRAL KY MAY DROP SE IN TO THE NC MTNS LATE THIS EVENING (PER THE CONVECTION ALLOWING MODELS). SO WILL LEAVE THE CHC POP ACRS THE NRN TIER FOR LATE EVENING INTO OVERNIGHT. THE UPSTATE AND NE GA MAY NOT SEE ANY PRECIP...IF THE LATEST TRENDS HOLD. AS OF 230 PM EDT...WEAK UPPER RIDGING CONTINUES TO STRENGTHEN DOWN THE EASTERN SEABOARD IN RESPONSE TO A DIGGING UPPER TROUGH ACROSS THE ROCKIES. STRONG SHORTWAVE CROSSING THE FLOW ACROSS THE CENTRAL APPALACHIANS IS RESULTING IN A FAIRLY SIGNIFICANT CONVECTIVE COMPLEX MOVING INTO WEST VIRGINIA AT AFD TIME. HI-RES REFLECTIVITY GUIDANCE WANTS TO CONTINUE TO DRAG THIS COMPLEX SOUTHEAST ALONG THE NORTHWEST FLOW ALOFT...CLIPPING THE NORTHERN PORTION OF OUR FORECAST AREA. SBCAPE VALUES EAST OF THE RIDGES CONTINUE TO INCREASE AND ARE UP TO BETWEEN 1000-1500 J/KG AT AFD TIME AND LOOK TO SUPPORT THE SUSTAINING OF THIS COMPLEX. ADDITIONALLY...WITH THE INCREASING SBCAPE VALUES...CANNOT RULE OUT AT LEAST ISOLATED CONVECTION ELSEWHERE ACROSS THE AREA THIS AFTERNOON AND EVENING AS THE LOW LEVEL CAP ERODES. BUFR SOUNDINGS MAX OUT BETWEEN 1500-2000 J/KG AT VARIOUS LOCATIONS ACROSS THE FORECAST AREA AND WITH SLIGHTLY STEEPER LAPSE RATES THAN YESTERDAY...CERTAINLY CANNOT RULE OUT ISOLATED SEVERE THOUGH BEST CHANCES REMAIN ACROSS EXTREME NORTHERN ZONES CLOSER TO THE UPPER SHORTWAVE. THREATS SIMILAR TO YESTERDAY WITH LARGE HAIL AND DAMAGING WINDS. UPPER RIDGING WILL CONTINUE TO INCREASE OVERNIGHT BUT COULD STILL SEE ANOTHER ROUND OF LOW CLOUDS AND LIGHT FOG THURSDAY MORNING. THE ROCKIES UPPER WAVE WILL PUSH INTO THE PLAINS DURING THE DAY ON THURSDAY...DRAGGING A FRONT THROUGH THE MID MISSISSIPPI VALLEY. WE REMAIN SOLIDLY IN THE WARM SECTOR ACROSS THE SOUTHEAST WITH BOTH GFS AND NAM INCREASING CAPES ACROSS ESPECIALLY THE PIEDMONT TO BETWEEN 1500-2000 J/KG AGAIN. NO REAL DEEP LAYER BULK SHEAR TO SPEAK OF...TOO FAR AHEAD OF THE UPPER SYSTEM...BUT THERE IS ENOUGH TURNING IN THE WIND PROFILE WITH THE SOUTHERLY WINDS AT THE SURFACE AND WEST TO SOUTHWESTERLY WINDS ALOFT TO RESULT IN SOME DECENT HELICITY VALUES THAT MAY HELP TO ORGANIZE CONVECTION THURSDAY AFTERNOON INTO EVENING. CURRENT SPC DAY2 OUTLOOK ONLY HAS OUR AREA IN GENERAL THUNDER BUT WOULD NOT BE SURPRISED TO AGAIN SEE ISOLATED SEVERE POTENTIAL. POPS THROUGH THE NEAR TERM CONTINUE TO FOLLOW A GENERAL DIURNAL TREND BUT HIGHER POPS ARE EMPHASIZED ACROSS NORTHERN ZONES CLOSER TO ANY SHORTWAVE ACTIVITY. TEMPERATURES REMAIN WARM UNDER THE INCREASING THICKNESSES ALOFT... WITH LOWS TONIGHT A GOOD 10-15 DEGREES ABOVE NORMAL AND HIGHS THURSDAY 10 OR SO DEGREES ABOVE SEASONAL NORMALS. GUIDANCE OVERALL IN FAIRLY GOOD AGREEMENT. && .SHORT TERM /TONIGHT THROUGH SATURDAY/... AS OF 215 PM WEDNESDAY...THE MAIN FOCUS FOR THE SHORT TERM CONTINUES TO BE THE POTENTIAL FOR SEVERE THUNDERSTORMS AHEAD/ALONG A COLD FRONT MAINLY IN THE AFTERNOON. BUT BEFORE WE GET THERE...WE WILL STILL HAVE TO DEAL WITH A CHANCE OF THUNDERSTORMS...PERHAPS A FEW STRONG TO SEVERE...ON THURSDAY EVENING. THE WHOLE FCST AREA WARRANTS A CHANCE POP INTO THURSDAY EVENING...BUT LOSS OF DAYTIME HEATING SHOULD REDUCE THE CHANCES BACK TO WHERE SOME MECHANICAL FORCING REMAINS IN THE VICINITY OF THE BLUE RIDGE BY LATE EVENING. THE PRECIP CHANCES THEN START RAMPING UP ON THE TN BORDER AFTER MIDNIGHT AS CONVECTION ALONG A PRE-FRONTAL TROF MAY REACH THE NC MTNS BEFORE DAYBREAK. EXPECT AREAS E OF THE MTNS TO GET A BREAK IN THE ACTION AROUND SUNRISE FRIDAY...WHICH RESULTS IN A SHORT PERIOD WITH A LARGE POP GRADIENT FROM W TO E. TEMPS SHOULD BE SEASONALLY MILD OVERNIGHT. WHICH BRINGS US TO FRIDAY. THE MODELS SHOW EXCELLENT FORCING ALONG THE FRONT TO THE WEST DURING THE EARLY MORNING HOURS...BUT THIS WEAKENS AS IT CROSSES THE WESTERN CAROLINAS. THE RECENT MODEL TREND SHOWING POORER CONVERGENCE ACROSS THE FRONT ALSO CONTINUES ON THE NEW RUNS. THE CORE OF THE LOW LEVEL JET PULLS NWD BY AFTERNOON AND 850 MB WINDS WEAKEN AND VEER. THE RESULT IS SOMEWHAT WEAKER SHEAR AND A MORE UNIDIRECTIONAL HODOGRAPH. ON THE OTHER HAND...A SLIGHT DELAY IN THE TIMING ALLOWS SURFACE BASED CAPE IN THE MODELS TO CLIMB A BIT HIGHER...CLOSER TO 1000 J/KG ON THE GFS AND ABOVE 1500 J/KG ON THE OPERATIONAL NAM. SO...THE TREND ON THE SIGNALS IS MIXED. STILL THINK WE HAVE A DECENT CHANCE FOR ORGANIZED SEVERE CONVECTION... ESPECIALLY E OF THE MTNS...SO WE WILL CONTINUE TO MENTION IT IN THE HWO. THE PRECIP PROBABILITY GOES UP TO CATEGORICAL ON THE TN BORDER...BUT HAVE KEPT ONLY A LIKELY E OF THE MTNS BECAUSE IT IS POSSIBLE THAT A CONVECTIVE LINE COULD BREAK UP A BIT OVER THE MTNS AND THEN FILL BACK IN AS IT IS LEAVING THE EASTERN PART OF THE FCST AREA LATE IN THE DAY. THE CONVECTION SHOULD PUSH E OF THE REGION IN THE EARLY EVENING EVEN IF THE FRONT GETS HELD UP ON THE MTNS. PRECIP CHANCES RAMP DOWN FROM THE WEST WITH FRONTAL PASSAGE. ON SATURDAY...A NRN STREAM TROF PASSING TO THE WEST WILL RESULT IN A NEARLY ZONAL FLOW ACROSS THE SOUTHEAST. HIGH PRESSURE SHOULD BUILD IN TO DRY US OUT AND GIVE US A NORMAL SPRING DAY. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 215 PM WED...GUIDANCE IN GENERAL AGREEMENT WITH SHORT WAVE RIDGING SETTING UP FOR SUNDAY AND MONDAY AS A SRN STREAM UPPER LOW DEVELOPS AND MOVES INTO THE SRN PLAINS. AHEAD OF THIS SYSTEM...A DAMPENING SHORT WAVE TOPS THE RIDGE AND CROSSES THE AREA TUE AS THE UPPER LOW WEAKENS AND MOVES INTO THE GREAT LAKES. RIDGING BEGINS TO REBUILD ON WED...BUT SWLY FLOW ALOFT REMAINS OVER OUR AREA WITH WEAK SHORT WAVES MOVING THRU THE FLOW. AT THE SFC...DRY AND MILD HIGH PRESSURE MOVES IN ON SUN...WITH POTENTIALLY ENUF LINGERING MOISTURE FOR ISOLATES SHOWERS ACROSS THE MTNS. TEMPS WILL BE UP TO 5 DEGREES ABOVE NORMAL. THE HIGH MOVES EAST MON WITH SLY RETURN FLOW DEVELOPING. WITHOUT ANY STRONG FORCING DEVELOPING...EXPECT SCT SHRA ACROSS THE MTNS AND ISOLATED SHRA ELSEWHERE. TEMPS 5 TO 10 DEGREES ABOVE NORMAL. THE SLY RETURN FLOW REMAINS IN PLACE TUE AND WED WITH WEAK SFC RIDGING OVER THE AREA AND ANY FRONTAL SYSTEMS WELL TO OUR NORTH. THIS WILL CREATE SCT MAINLY DIURNAL CONVECTION BOTH DAYS. LOWS WILL BE UP TO 15 DEGREES ABOVE NORMAL WITH HIGHS AROUND 10 DEGREES ABOVE NORMAL. && .AVIATION /05Z THURSDAY THROUGH MONDAY/... AT KCLT...MODEL TIME HEIGHTS SUGGEST LOW VFR CLOUDS WILL BE PRESENT FOR MUCH OF THE FORECAST PERIOD...WITH THE CURRENT CIG ERODING AFTER DAYBREAK. A LOW VFR CIG WOULD RETURN TONIGHT AHEAD OF AN ADVANCING COLD FRONT. GUIDANCE HAS BACKED OFF ON A DAYBREAK VSBY RESTRICTIONS...AND WITH A LACK OF RAINFALL YESTERDAY THIS SCENARIO HAS BEEN ACCEPTED. INSTABILITY WILL BE PRESENT AGAIN TODAY...SUPPORTING THUNDERSTORMS THAT MAY LINGER INTO THE EVENING AHEAD OF THE APPROACHING COLD FRONT. ANY RESTRICTIONS WOULD BE ASSOCIATED WITH PRECIPITATION. WINDS WILL FAVOR THE S AND SW. ELSEWHERE...VSBY RESTRICTIONS ARE NOT SUPPORTED AT TAF SITES BY A MODEL CONSENSUS...AND WITH NO RAIN YESTERDAY...THIS OUTCOME HAS BEEN ACCEPTED. MODEL TIME HEIGHTS SHOW LOW VFR CLOUDS PERSISTING... ALTHOUGH SATELLITE IMAGERY SHOWS SOME AREAS WHERE HIGH CIRRUS IS THE PREVAILING CLOUD. LOW VFR CIGS ARE NOT EXPECTED UNTIL THIS AFTERNOON AHEAD OF AN APPROACHING COLD FRONT. INSTABILITY WILL SUPPORT THUNDERSTORMS TODAY AND TONIGHT AS THE FRONT ADVANCES...WITH ASSOCIATED RESTRICTIONS POSSIBLE. WINDS WILL FAVOR THE S AND SW. OUTLOOK...A COLD FRONT WILL PUSH THROUGH FRIDAY...BRINGING WITH IT THE POTENTIAL FOR CONVECTION. CONDITIONS IMPROVE FOR THE WEEKEND AFTER THE FRONT CLEARS THE AREA. MOISTURE RETURNS LATE MONDAY. CONFIDENCE TABLE... 05-11Z 11-17Z 17-23Z 23-00Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...NED NEAR TERM...ARK/JAT/TDP SHORT TERM...PM LONG TERM...RWH AVIATION...JAT
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1233 PM CDT THU APR 9 2015 .AVIATION... CONCERNS..TIMING OF FROPA AND CONVECTION. AT MIDDAY...A COLD FRONT EXTENDED FROM SOUTHEAST KANSAS TO EAST OF WICHITA FALLS TO SOUTH OF LUBBOCK. THE FRONT IS EXPECTED TO ARRIVE AT KAFW NEAR 23Z...KDFW 2330Z...KDAL AROUND 00Z AND KACT BY 03Z. SOME CONVECTION...MOSTLY SHRA...COULD AFFECT THE TERMINALS EARLY AFTERNOON...THEN EXPECT SOME TSRA MIXED IN. STRONG TO SEVERE TSRA ARE EXPECTED TO FORM ALONG THE FRONT MID/LATE AFTERNOON FROM NORTHWEST ARKANSAS AND SOUTHEAST OKLAHOMA AND BUILD DOWN INTO NORTHEAST/NORTH TEXAS. WILL CARRY VCTS 20-02Z WITH THE BEST TIME PERIOD FOR AFFECTING THE METROPLEX TERMINALS BEING 22-00Z...AND KACT 02-05Z. SOUTHERLY WINDS 10 TO 16 KNOTS WILL VEER WESTERLY AS A PRE-FRONTAL SURFACE TROUGH ARRIVES AROUND 20Z...THEN GO NORTH 14-20 KNOTS AND GUSTY THIS EVENING AFTER FROPA. WINDS WILL BECOME NORTHEASTERLY NEAR 10 KNOTS MID MORNING TOMORROW. CIGS...KACT WILL REMAIN MVFR THROUGH MID AFTERNOON THEN LIFTING TO AROUND 4000 FEET THIS EVENING AND BKN040-050 OVERNIGHT THROUGH TOMORROW MORNING. SCATTERED MVFR CIGS ACROSS THE METROPLEX SHOULD LIFT WEST TO EAST DURING THE AFTERNOON WITH SCT-BKN035-040 UNTIL 02Z THEN BECOMING VFR AFTERWARD. 75 && .UPDATE... A QUICK UPDATE HAS BEEN DONE TO INCREASE THE POPS FOR THIS MORNING ACROSS CENTRAL TEXAS. MORE SHOWERS AND A FEW EMBEDDED THUNDERSTORMS DEVELOPED BETWEEN COLEMAN...GRANBURY AND LAMPASAS. THIS ACTIVITY WILL CONTINUE TO MOVE EAST ACROSS THE AREA SOUTH OF THE I-20 CORRIDOR THIS MORNING. 58 && .PREV DISCUSSION... /ISSUED 400 AM CDT THU APR 9 2015/ A BAND OF ELEVATED SHOWERS AND THUNDERSTORMS EXTENDED ALONG A GAINESVILLE TO BROWNWOOD LINE AT 3 AM...THIS ACTIVITY WILL CONTINUE TO MOVE EAST ACROSS THE FORECAST AREA THROUGH SUNRISE. AS NOTED IN YESTERDAY EVENINGS /927 PM WED/ AREA FORECAST DISCUSSION...THE 00Z SOUNDING INDICATED A PROFILE THAT IS FAVORABLE FOR HEAT BURSTS. ALTHOUGH WE HAVE NOT SEE ANY OF THOSE OVERNIGHT...SOME WIND GUSTS OF 35 TO 40 MPH ARE EXPECTED WITH SOME OF THIS ACTIVITY THROUGH DAYBREAK. THE CAP SHOULD HOLD OFF ANY SURFACE BASED STORMS UNTIL THIS AFTERNOON...WHEN A COLD FRONT MOVES INTO THE REGION. MOST OF THE HIGH RESOLUTION MODELS INDICATE THAT THE FRONT WILL MOVE TO NEAR OR JUST SOUTH OF A BONHAM TO DFW TO COMANCHE LINE BY 00Z. WITH THE ARW...NMM AND HRRR BRINGING THE FRONT TO NEAR THE LINE AROUND 21Z...WHILE THE NAM HOLDS THE FRONT OFF UNTIL AFTER 00Z. STRONG TO SEVERE STORMS AREA EXPECTED TO DEVELOP MID TO LATE AFTERNOON ALONG THE FRONT. WITH MU CAPES IN THE 1500 TO 2000 J/KG RANGE LATE THIS AFTERNOON...ALONG WITH 0-6 KM BULK SHEAR VALUES IN THE 35-45 KT RANGE...SOME SUPERCELLS STORMS ARE POSSIBLE WHICH WILL HAVE THE POTENTIAL TO PRODUCE SOME VERY LARGE HAIL AND DAMAGING DOWNBURST WINDS. THERE IS ALSO A POTENTIAL FOR A FEW TORNADOES LATE THIS AFTERNOON AND EARLY THIS EVENING WITH 0-3KM HELICITY VALUES APPROACHING 200 M2/S2. EXPECT THE FRONT TO CONTINUE TO MOVE SOUTHEAST TONIGHT...AND SHOULD MOVE TO THE SOUTH OF THE ENTIRE FORECAST AREA WELL BEFORE DAYBREAK FRIDAY. THE RISK OF SEVERE WEATHER WILL CONTINUE PAST MIDNIGHT AHEAD OF THE FRONT. BY DAYBREAK FRIDAY WITH THE FRONT HAVING MOVED INTO SOUTH TEXAS...THE BEST CHANCES OF RAIN WILL BE TO OUR SOUTH BUT WILL KEEP A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS MAINLY SOUTH OF THE I-20 CORRIDOR WITH 30-40 PERCENT POPS SOUTH OF A KILLEEN TO PALESTINE LINE. THE FRONT WILL START TO LIFT BACK TO THE NORTH BY SATURDAY MORNING IN ADVANCE OF THE NEXT SHORT WAVE. THIS WILL RESULT IN INCREASING CHANCES OF SHOWERS AND THUNDERSTORMS AREA WIDE OVERNIGHT FRIDAY NIGHT AND SATURDAY. WE WILL REMAIN IN SOUTHWESTERLY FLOW ALOFT THROUGH AT LEAST TUESDAY NIGHT WHEN AN UPPER LEVEL LOW THAT WILL MOVE INTO BAJA CALIFORNIA SUNDAY...WILL MOVE ACROSS THE PLAINS. 58 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 83 55 73 55 74 / 40 40 10 30 40 WACO, TX 84 58 73 58 76 / 40 60 20 30 40 PARIS, TX 79 51 73 52 73 / 40 70 10 30 40 DENTON, TX 83 53 73 54 73 / 30 30 10 30 40 MCKINNEY, TX 81 53 73 55 73 / 40 50 10 30 40 DALLAS, TX 82 55 73 55 74 / 40 50 10 30 40 TERRELL, TX 80 55 73 55 74 / 40 80 10 30 40 CORSICANA, TX 82 57 73 58 75 / 40 80 20 30 40 TEMPLE, TX 84 60 73 59 76 / 40 50 20 40 40 MINERAL WELLS, TX 86 53 73 54 74 / 20 20 10 30 40 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 75/
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
645 AM CDT THU APR 9 2015 .AVIATION... ACTIVE WEATHER CONTINUES ACROSS THE CENTRAL PART OF THE CONUS IN ASSOCIATION WITH AN UPPER LEVEL TROUGH CURRENTLY TRAVERSING THE CENTRAL PLAINS. NORTH TEXAS RESIDES ON THE SOUTHERN EXTENT OF THE LIFT ASSOCIATED WITH THE SYSTEM...WHICH WHEN COMBINED WITH THE STRONG LOW LEVEL JET IN PLACE...HAS RESULTED IN ELEVATED CONVECTION ACROSS PARTS OF THE AREA. THE EAST-WEST AXIS OF STORMS HAS SHIFTED TO BETWEEN THE DALLAS-FORT WORTH METROPLEX AND KACT...AND WILL LIKELY PERSIST IN THIS REGION UNTIL THE LOW LEVEL JET MIXES OUT MID MORNING. ADDITIONAL THUNDERSTORMS WILL BECOME LIKELY THIS AFTERNOON AS A COLD FRONT SURGES SOUTH INTO NORTH TEXAS. THE FRONT WILL BE REACHING THE METROPLEX DURING PEAK HEATING HOURS LATE THIS AFTERNOON...WITH SCATTERED THUNDERSTORMS DEVELOPING IN THE VICINITY OF THE BOUNDARY. STORMS SHOULD INITIALLY BE SCATTERED IN NATURE IN AND AROUND THE METROPLEX BEFORE EVOLVING INTO A SQUALL LINE AS THE FRONT PUSHES FARTHER SOUTH AND EAST ACROSS THE WACO AREA THIS EVENING. THE LATEST MODEL GUIDANCE SUGGESTS FROPA IN THE METROPLEX AROUND 00-02Z THEN IN THE WACO AREA 04-06Z. FOR NOW...WE WILL MAINTAIN VCTS IN AREA TAFS BUT LATER FORECASTS MAY REQUIRE THE ADDITION OF A TEMPO GROUP FOR THUNDER DEPENDING ON FUTURE TRENDS. ACTIVITY SHOULD SHIFT SOUTH AND EAST OF ALL TAF LOCATIONS AROUND 10/O6Z ALONG WITH THE FRONT. 30 && .UPDATE... A QUICK UPDATE HAS BEEN DONE TO INCREASE THE POPS FOR THIS MORNING ACROSS CENTRAL TEXAS. MORE SHOWERS AND A FEW EMBEDDED THUNDERSTORMS DEVELOPED BETWEEN COLEMAN...GRABURY AND LAMPASAS. THIS ACTIVITY WILL CONTINUE TO MOVE EAST ACROSS THE AREA SOUTH OF THE I-20 CORRIDOR THIS MORNING. 58 && .PREV DISCUSSION... /ISSUED 400 AM CDT THU APR 9 2015/ A BAND OF ELEVATED SHOWERS AND THUNDERSTORMS EXTENDED ALONG A GAINESVILLE TO BROWNWOOD LINE AT 3 AM...THIS ACTIVITY WILL CONTINUE TO MOVE EAST ACROSS THE FORECAST AREA THROUGH SUNRISE. AS NOTED IN YESTERDAY EVENINGS /927 PM WED/ AREA FORECAST DISCUSSION...THE 00Z SOUNDING INDICATED A PROFILE THAT IS FAVORABLE FOR HEAT BURSTS. ALTHOUGH WE HAVE NOT SEE ANY OF THOSE OVERNIGHT...SOME WIND GUSTS OF 35 TO 40 MPH ARE EXPECTED WITH SOME OF THIS ACTIVITY THROUGH DAYBREAK. THE CAP SHOULD HOLD OFF ANY SURFACE BASED STORMS UNTIL THIS AFTERNOON...WHEN A COLD FRONT MOVES INTO THE REGION. MOST OF THE HIGH RESOLUTION MODELS INDICATE THAT THE FRONT WILL MOVE TO NEAR OR JUST SOUTH OF A BONHAM TO DFW TO COMANCHE LINE BY 00Z. WITH THE ARW...NMM AND HRRR BRINGING THE FRONT TO NEAR THE LINE AROUND 21Z...WHILE THE NAM HOLDS THE FRONT OFF UNTIL AFTER 00Z. STRONG TO SEVERE STORMS AREA EXPECTED TO DEVELOP MID TO LATE AFTERNOON ALONG THE FRONT. WITH MU CAPES IN THE 1500 TO 2000 J/KG RANGE LATE THIS AFTERNOON...ALONG WITH 0-6 KM BULK SHEAR VALUES IN THE 35-45 KT RANGE...SOME SUPERCELLS STORMS ARE POSSIBLE WHICH WILL HAVE THE POTENTIAL TO PRODUCE SOME VERY LARGE HAIL AND DAMAGING DOWNBURST WINDS. THERE IS ALSO A POTENTIAL FOR A FEW TORNADOES LATE THIS AFTERNOON AND EARLY THIS EVENING WITH 0-3KM HELICITY VALUES APPROACHING 200 M2/S2. EXPECT THE FRONT TO CONTINUE TO MOVE SOUTHEAST TONIGHT...AND SHOULD MOVE TO THE SOUTH OF THE ENTIRE FORECAST AREA WELL BEFORE DAYBREAK FRIDAY. THE RISK OF SEVERE WEATHER WILL CONTINUE PAST MIDNIGHT AHEAD OF THE FRONT. BY DAYBREAK FRIDAY WITH THE FRONT HAVING MOVED INTO SOUTH TEXAS...THE BEST CHANCES OF RAIN WILL BE TO OUR SOUTH BUT WILL KEEP A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS MAINLY SOUTH OF THE I-20 CORRIDOR WITH 30-40 PERCENT POPS SOUTH OF A KILLEEN TO PALESTINE LINE. THE FRONT WILL START TO LIFT BACK TO THE NORTH BY SATURDAY MORNING IN ADVANCE OF THE NEXT SHORT WAVE. THIS WILL RESULT IN INCREASING CHANCES OF SHOWERS AND THUNDERSTORMS AREA WIDE OVERNIGHT FRIDAY NIGHT AND SATURDAY. WE WILL REMAIN IN SOUTHWESTERLY FLOW ALOFT THROUGH AT LEAST TUESDAY NIGHT WHEN AN UPPER LEVEL LOW THAT WILL MOVE INTO BAJA CALIFORNIA SUNDAY...WILL MOVE ACROSS THE PLAINS. 58 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 83 55 73 55 74 / 40 40 10 30 40 WACO, TX 84 58 73 58 76 / 40 60 20 30 40 PARIS, TX 79 51 73 52 73 / 40 70 10 30 40 DENTON, TX 83 53 73 54 73 / 30 30 10 30 40 MCKINNEY, TX 81 53 73 55 73 / 40 50 10 30 40 DALLAS, TX 82 55 73 55 74 / 40 50 10 30 40 TERRELL, TX 80 55 73 55 74 / 40 80 10 30 40 CORSICANA, TX 82 57 73 58 75 / 40 80 20 30 40 TEMPLE, TX 84 60 73 59 76 / 40 50 20 40 40 MINERAL WELLS, TX 86 53 73 54 74 / 20 20 10 30 40 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 30/58
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
601 AM CDT THU APR 9 2015 .UPDATE... A QUICK UPDATE HAS BEEN DONE TO INCREASE THE POPS FOR THIS MORNING ACROSS CENTRAL TEXAS. MORE SHOWERS AND A FEW EMBEDDED THUNDERSTORMS DEVELOPED BETWEEN COLEMAN...GRABURY AND LAMPASAS. THIS ACTIVITY WILL CONTINUE TO MOVE EAST ACROSS THE AREA SOUTH OF THE I-20 CORRIDOR THIS MORNING. 58 && .AVIATION... A QUICK UPDATE HAS BEEN DONE TO INCREASE THE POPS THIS MORNING ACROSS CENTRAL TEXAS. MORE SHOWERS AND A FEW EMBEDDED THUNDERSTORMS DEVELOPED BETWEEN COLEMAN...GRABURY AND LAMPASAS. THIS ACTIVITY WILL CONTINUE TO MOVE EAST ACROSS THE AREA SOUTH OF THE I-20 CORRIDOR. /ISSUED 1149 PM CDT WED APR 8 2015/ /06Z TAFS/ SOME MVFR CIGS ARE ALREADY LOCATED AROUND THE AREA BUT MVFR CIGS ARE EXPECTED TO SPREAD OVER ALL THE TAF SITES BY 09-10Z. GUSTY WINDS ARE OCCURRING DUE TO DISSIPATING RAIN AND STORMS IN THE AREA AND THE WINDS OVERNIGHT ARE EXPECTED TO PREVAIL 15-20 KTS WITH GUSTS UP TO 30 KTS. SOME ADDITIONAL THUNDERSTORMS ARE STILL POSSIBLE OVERNIGHT AND WILL MAINTAIN A VCTS MENTION IN THE METROPLEX BETWEEN 09-12Z. CIGS WILL IMPROVE ABOVE 2 KFT BY MIDDAY THURSDAY AND THEN INTO VFR CATEGORY BY MID-LATE AFTERNOON. ANOTHER ROUND OF THUNDERSTORMS IS EXPECTED AS A COLD FRONT MOVES ACROSS THE AREA. THUNDERSTORMS WILL BE POSSIBLE IN THE METROPLEX AHEAD OF THE FRONT FROM 09/21-10/02Z AND AT KACT BETWEEN 10/03-07Z. THESE STORMS COULD BE STRONG OR SEVERE WITH A LARGE HAIL AND/OR DAMAGING WIND THREAT. THE WINDS WILL SHIFT TO THE NORTH THURSDAY EVENING AS THE FRONT MOVES THROUGH. JLDUNN && .PREV DISCUSSION... /ISSUED 400 AM CDT THU APR 9 2015/ A BAND OF ELEVATED SHOWERS AND THUNDERSTORMS EXTENDED ALONG A GAINESVILLE TO BROWNWOOD LINE AT 3 AM...THIS ACTIVITY WILL CONTINUE TO MOVE EAST ACROSS THE FORECAST AREA THROUGH SUNRISE. AS NOTED IN YESTERDAY EVENINGS /927 PM WED/ AREA FORECAST DISCUSSION...THE 00Z SOUNDING INDICATED A PROFILE THAT IS FAVORABLE FOR HEAT BURSTS. ALTHOUGH WE HAVE NOT SEE ANY OF THOSE OVERNIGHT...SOME WIND GUSTS OF 35 TO 40 MPH ARE EXPECTED WITH SOME OF THIS ACTIVITY THROUGH DAYBREAK. THE CAP SHOULD HOLD OFF ANY SURFACE BASED STORMS UNTIL THIS AFTERNOON...WHEN A COLD FRONT MOVES INTO THE REGION. MOST OF THE HIGH RESOLUTION MODELS INDICATE THAT THE FRONT WILL MOVE TO NEAR OR JUST SOUTH OF A BONHAM TO DFW TO COMANCHE LINE BY 00Z. WITH THE ARW...NMM AND HRRR BRINGING THE FRONT TO NEAR THE LINE AROUND 21Z...WHILE THE NAM HOLDS THE FRONT OFF UNTIL AFTER 00Z. STRONG TO SEVERE STORMS AREA EXPECTED TO DEVELOP MID TO LATE AFTERNOON ALONG THE FRONT. WITH MU CAPES IN THE 1500 TO 2000 J/KG RANGE LATE THIS AFTERNOON...ALONG WITH 0-6 KM BULK SHEAR VALUES IN THE 35-45 KT RANGE...SOME SUPERCELLS STORMS ARE POSSIBLE WHICH WILL HAVE THE POTENTIAL TO PRODUCE SOME VERY LARGE HAIL AND DAMAGING DOWNBURST WINDS. THERE IS ALSO A POTENTIAL FOR A FEW TORNADOES LATE THIS AFTERNOON AND EARLY THIS EVENING WITH 0-3KM HELICITY VALUES APPROACHING 200 M2/S2. EXPECT THE FRONT TO CONTINUE TO MOVE SOUTHEAST TONIGHT...AND SHOULD MOVE TO THE SOUTH OF THE ENTIRE FORECAST AREA WELL BEFORE DAYBREAK FRIDAY. THE RISK OF SEVERE WEATHER WILL CONTINUE PAST MIDNIGHT AHEAD OF THE FRONT. BY DAYBREAK FRIDAY WITH THE FRONT HAVING MOVED INTO SOUTH TEXAS...THE BEST CHANCES OF RAIN WILL BE TO OUR SOUTH BUT WILL KEEP A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS MAINLY SOUTH OF THE I-20 CORRIDOR WITH 30-40 PERCENT POPS SOUTH OF A KILLEEN TO PALESTINE LINE. THE FRONT WILL START TO LIFT BACK TO THE NORTH BY SATURDAY MORNING IN ADVANCE OF THE NEXT SHORT WAVE. THIS WILL RESULT IN INCREASING CHANCES OF SHOWERS AND THUNDERSTORMS AREA WIDE OVERNIGHT FRIDAY NIGHT AND SATURDAY. WE WILL REMAIN IN SOUTHWESTERLY FLOW ALOFT THROUGH AT LEAST TUESDAY NIGHT WHEN AN UPPER LEVEL LOW THAT WILL MOVE INTO BAJA CALIFORNIA SUNDAY...WILL MOVE ACROSS THE PLAINS. 58 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 83 55 73 55 74 / 40 40 10 30 40 WACO, TX 84 58 73 58 76 / 40 60 20 30 40 PARIS, TX 79 51 73 52 73 / 40 70 10 30 40 DENTON, TX 83 53 73 54 73 / 30 30 10 30 40 MCKINNEY, TX 81 53 73 55 73 / 40 50 10 30 40 DALLAS, TX 82 55 73 55 74 / 40 50 10 30 40 TERRELL, TX 80 55 73 55 74 / 40 80 10 30 40 CORSICANA, TX 82 57 73 58 75 / 40 80 20 30 40 TEMPLE, TX 84 60 73 59 76 / 40 50 20 40 40 MINERAL WELLS, TX 86 53 73 54 74 / 20 20 10 30 40 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 30/58
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
400 AM CDT THU APR 9 2015 .DISCUSSION... A BAND OF ELEVATED SHOWERS AND THUNDERSTORMS EXTENDED ALONG A GAINESVILLE TO BROWNWOOD LINE AT 3 AM...THIS ACTIVITY WILL CONTINUE TO MOVE EAST ACROSS THE FORECAST AREA THROUGH SUNRISE. AS NOTED IN YESTERDAY EVENINGS /927 PM WED/ AREA FORECAST DISCUSSION...THE 00Z SOUNDING INDICATED A PROFILE THAT IS FAVORABLE FOR HEAT BURSTS. ALTHOUGH WE HAVE NOT SEE ANY OF THOSE OVERNIGHT...SOME WIND GUSTS OF 35 TO 40 MPH ARE EXPECTED WITH SOME OF THIS ACTIVITY THROUGH DAYBREAK. THE CAP SHOULD HOLD OFF ANY SURFACE BASED STORMS UNTIL THIS AFTERNOON...WHEN A COLD FRONT MOVES INTO THE REGION. MOST OF THE HIGH RESOLUTION MODELS INDICATE THAT THE FRONT WILL MOVE TO NEAR OR JUST SOUTH OF A BONHAM TO DFW TO COMANCHE LINE BY 00Z. WITH THE ARW...NMM AND HRRR BRINGING THE FRONT TO NEAR THE LINE AROUND 21Z...WHILE THE NAM HOLDS THE FRONT OFF UNTIL AFTER 00Z. STRONG TO SEVERE STORMS AREA EXPECTED TO DEVELOP MID TO LATE AFTERNOON ALONG THE FRONT. WITH MU CAPES IN THE 1500 TO 2000 J/KG RANGE LATE THIS AFTERNOON...ALONG WITH 0-6 KM BULK SHEAR VALUES IN THE 35-45 KT RANGE...SOME SUPERCELLS STORMS ARE POSSIBLE WHICH WILL HAVE THE POTENTIAL TO PRODUCE SOME VERY LARGE HAIL AND DAMAGING DOWNBURST WINDS. THERE IS ALSO A POTENTIAL FOR A FEW TORNADOES LATE THIS AFTERNOON AND EARLY THIS EVENING WITH 0-3KM HELICITY VALUES APPROACHING 200 M2/S2. EXPECT THE FRONT TO CONTINUE TO MOVE SOUTHEAST TONIGHT...AND SHOULD MOVE TO THE SOUTH OF THE ENTIRE FORECAST AREA WELL BEFORE DAYBREAK FRIDAY. THE RISK OF SEVERE WEATHER WILL CONTINUE PAST MIDNIGHT AHEAD OF THE FRONT. BY DAYBREAK FRIDAY WITH THE FRONT HAVING MOVED INTO SOUTH TEXAS...THE BEST CHANCES OF RAIN WILL BE TO OUR SOUTH BUT WILL KEEP A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS MAINLY SOUTH OF THE I-20 CORRIDOR WITH 30-40 PERCENT POPS SOUTH OF A KILLEEN TO PALESTINE LINE. THE FRONT WILL START TO LIFT BACK TO THE NORTH BY SATURDAY MORNING IN ADVANCE OF THE NEXT SHORT WAVE. THIS WILL RESULT IN INCREASING CHANCES OF SHOWERS AND THUNDERSTORMS AREA WIDE OVERNIGHT FRIDAY NIGHT AND SATURDAY. WE WILL REMAIN IN SOUTHWESTERLY FLOW ALOFT THROUGH AT LEAST TUESDAY NIGHT WHEN AN UPPER LEVEL LOW THAT WILL MOVE INTO BAJA CALIFORNIA SUNDAY...WILL MOVE ACROSS THE PLAINS. 58 && .AVIATION... /ISSUED 1149 PM CDT WED APR 8 2015/ /06Z TAFS/ SOME MVFR CIGS ARE ALREADY LOCATED AROUND THE AREA BUT MVFR CIGS ARE EXPECTED TO SPREAD OVER ALL THE TAF SITES BY 09-10Z. GUSTY WINDS ARE OCCURRING DUE TO DISSIPATING RAIN AND STORMS IN THE AREA AND THE WINDS OVERNIGHT ARE EXPECTED TO PREVAIL 15-20 KTS WITH GUSTS UP TO 30 KTS. SOME ADDITIONAL THUNDERSTORMS ARE STILL POSSIBLE OVERNIGHT AND WILL MAINTAIN A VCTS MENTION IN THE METROPLEX BETWEEN 09-12Z. CIGS WILL IMPROVE ABOVE 2 KFT BY MIDDAY THURSDAY AND THEN INTO VFR CATEGORY BY MID-LATE AFTERNOON. ANOTHER ROUND OF THUNDERSTORMS IS EXPECTED AS A COLD FRONT MOVES ACROSS THE AREA. THUNDERSTORMS WILL BE POSSIBLE IN THE METROPLEX AHEAD OF THE FRONT FROM 09/21-10/02Z AND AT KACT BETWEEN 10/03-07Z. THESE STORMS COULD BE STRONG OR SEVERE WITH A LARGE HAIL AND/OR DAMAGING WIND THREAT. THE WINDS WILL SHIFT TO THE NORTH THURSDAY EVENING AS THE FRONT MOVES THROUGH. JLDUNN && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 83 55 73 55 74 / 40 40 10 30 40 WACO, TX 84 58 73 58 76 / 30 60 20 30 40 PARIS, TX 79 51 73 52 73 / 40 70 10 30 40 DENTON, TX 83 53 73 54 73 / 40 30 10 30 40 MCKINNEY, TX 81 53 73 55 73 / 40 50 10 30 40 DALLAS, TX 82 55 73 55 74 / 40 50 10 30 40 TERRELL, TX 80 55 73 55 74 / 40 80 10 30 40 CORSICANA, TX 82 57 73 58 75 / 40 80 20 30 40 TEMPLE, TX 84 60 73 59 76 / 40 50 20 40 40 MINERAL WELLS, TX 86 53 73 54 74 / 20 20 10 30 40 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 30/58
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1248 AM CDT THU APR 9 2015 .AVIATION... A CLUSTER OF SHRA IS MOVING EAST ACROSS THE HILL COUNTRY AND ESCARPMENT AREAS. HAVE GONE WITH VCSH AT KAUS/KSAT/KSSF OVERNIGHT AS THIS CLUSTER CONTINUES TO THE EAST. MVFR CIGS HAVE DEVELOPED FROM THE COASTAL PLAINS TO THE I-35 CORRIDOR. THESE CIGS WILL SPREAD WEST ACROSS THE HILL COUNTRY TO THE RIO GRANDE PLAINS AND KDRT OVERNIGHT WITH A BRIEF PERIOD OF IFR CIGS EARLY THURSDAY MORNING. HOWEVER...THERE IS A POSSIBILITY THAT THE CLUSTER OF SHRA DISRUPTS THE MVFR CIGS. A DRYLINE WILL MOVE INTO THE EDWARDS PLATEAU AND PARTS OF THE RIO GRANDE PLAINS MID MORNING INTO AFTERNOON AND THEN RETREATS BACK WEST THURSDAY NIGHT. SKIES WILL BECOME VFR BY LATE MORNING AT KDRT. EAST OF THE DRYLINE...CIGS WILL RISE TO VFR IN THE AFTERNOON. THERE IS SOME POSSIBILITY OF SHRA/TSRA ALONG AND EAST OF THE DRYLINE. WILL LEAVE MENTION OF THESE OUT OF THE TAFS DUE TO UNCERTAINTY ON LOCATION. MVFR CIGS REDEVELOP FROM THE COASTAL PLAINS ACROSS THE I-35 CORRIDOR INTO THE HILL COUNTRY THURSDAY NIGHT. A COLD FRONT SAGS SOUTH THROUGH CENTRAL TEXAS LATE TONIGHT AND EXPECT SOME SHRA/TSRA ALONG IT AND HAVE MENTIONED VCSH AT KAUS. S TO SE WINDS 7 TO 15 KTS PREVAIL. EXCEPT...W TO NW 4 TO 8 KTS BEHIND THE DRYLINE AND NE BEHIND THE COLD FRONT. && .PREV DISCUSSION... /ISSUED 936 PM CDT WED APR 8 2015/ UPDATE... /RAISED POPS...THUNDER CHANCES WRN THIRD/ FAST PACED CONVECTIVE CLUSTER ARRIVING FROM WEST TX IS A SOUTHWARD EXTENT OF A BROKEN LINE OF CONVECTION THAT EXTENDS NORTH INTO NW TX. THE SOUTHERN ENHANCEMENTS ARE LIKELY THE PRODUCT OF FAVORABLE JET DYNAMICS AND STEEPENING MID LEVEL LAPSE RATES. MOST OF THE HI-RES RUNS SHOWN THE ACTIVITY WEAKENING BEFORE REACHING THE I-35 CORRIDOR...BUT DO SHOW SOME AREAS OF LIGHT QPF FROM LIGHT SHOWERS. WILL EXTEND A MENTION OF SPRINKLES INTO SOUTHEAST COUNTIES AND BEEF UP POPS OVER MAINLY VAL VERDE COUNTY AND TO A SMALLER EXTENT THE RIO GRANDE PLAINS. OTHERWISE...THE FORECAST REMAINS ON TRACK. PREV DISCUSSION... /ISSUED 703 PM CDT WED APR 8 2015/ AVIATION... THERE ARE SOME SHOWERS AND THUNDERSTORMS MOVING ACROSS MEXICO TOWARD TEXAS AND THERE IS A CHANCE SOME OF THESE COULD MOVE INTO DRT OVER THE NEXT COUPLE OF HOURS. THERE IS ALSO A SLIGHT CHANCE FOR A SHOWER OR THUNDERSTORM IN AUSTIN AND SAN ANTONIO...BUT PROBABILITY IS TOO LOW TO INCLUDE IN THE TAFS. ANY STORMS THAT DO MOVE OVER AN AIRPORT WILL NOT CHANGE THE FLYING CATEGORY. VFR CIGS WILL PREVAIL AT ALL TERMINALS UNTIL LATE EVENING WHEN CIGS WILL LOWER TO MVFR IN AUSTIN AND SAN ANTONIO. CIGS WILL DROP AT DRT LATER TONIGHT WHEN THEY WILL ALSO DROP TO IFR AT AUSTIN AND SAN ANTONIO. IMPROVEMENT WILL COME LATE MORNING AND EARLY AFTERNOON THURSDAY. PREV DISCUSSION... /ISSUED 347 PM CDT WED APR 8 2015/ SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)... OVERALL HIGHLIGHTS FOR THIS PERIOD WILL FOCUS ON THE ISOLATED TO SCATTERED STRONG TO SEVERE STORM POSSIBILITIES THURSDAY AFTERNOON INTO THURSDAY EVENING FOR AREAS GENERALLY ALONG AND NORTH OF A FREDERICKSBURG TO LA GRANGE LINE. FOR TODAY...WATER VAPOR IMAGERY CHANNELS DEPICT A SHORTWAVE TROUGH OVER UTAH WITH RAP ANALYSIS INDICATING AN ENHANCED MID-LEVEL WIND SPEED BELT EXTENDING INTO SOUTH-CENTRAL TEXAS BACK WESTWARD INTO NORTHERN MEXICO. THE INCREASING H5-H3 WIND FLOW IS AIDING IN BETTER DIVERGENCE ALOFT AND HELPING GENERATE SOME ELEVATED SHOWERS ABOVE A CAPPING INVERSION. 315K THETA SURFACE DEPICTS LOWEST CONDENSATION PRESSURE DEFICITS WITH LOWER LAYERS STILL DRY. THIS IS LIMITING OVERALL AMOUNTS FROM REACHING THE GROUND SO FAR THIS AFTERNOON. THIS BIG QUESTION FOR LATE AFTERNOON WILL BE HOW MUCH CLOUD COVER EROSION OCCURS WHICH COULD ALLOW FOR MORE SURFACE HEATING AND POSSIBLY AID SURFACE BASED STORMS OUT WEST. VIS SATELLITE TRENDS SHOW CLEARING ACROSS MAVERICK BUT VAL VERDE REMAINS MOSTLY SOCKED IN. SOME ADDITIONAL CLEARING IS EXPECTED ACROSS THE NORTHERN RIO GRANDE PLAINS THROUGH 6PM BUT BOTH GFS/NAM FORECAST SOUNDINGS SUGGEST OVERALL CAP SHOULD HOLD AND LIMIT SURFACE BASED CONVECTIVE POTENTIAL. DESPITE THIS FACT...ELEVATED INSTABILITY WILL GROW AS CAPPING INVERSION THINS ABOVE 700MB. WHILE AN ISOLATED STRONG STORM CAPABLE OF SMALL HAIL OR WIND GUSTS TO 40 MPH CAN NOT BE ENTIRELY RULED OUT THROUGH THIS EVENING...THE CHANCES ARE RELATIVELY LOW. OVERNIGHT...EXPECT SOME LINGERING SHOWERS ACROSS THE RIO GRANDE PLAINS WITH SOUTHEASTERN AREAS MOSTLY DRY. FOR THURSDAY...THE SHORTWAVE TROUGH OVER UTAH WILL HELP PUSH A WEAK FRONT TOWARDS THE REGION THAT WILL IMPINGE ON THE DRYLINE TO EDGE TOWARDS THE HILL COUNTY BY THE AFTERNOON. AFTER MORNING CLOUD COVER SLOWLY ERODES...SURFACE INSTABILITY IS PROGGED TO INCREASE TOWARDS 3000 J/KG AS MIXING OCCURS BY MID AFTERNOON. BOTH NAM/GFS BUFR SOUNDINGS INDICATE THE EROSION OF THE CAP ACROSS NORTHERN AREAS WITH 30KT 0-6 KM SHEAR IN PLACE. WHILE NOT SUPER HIGH...THIS AMOUNT IN CONJUNCTION WITH A LOW-LEVEL FORCING BOUNDARY (DRYLINE) COULD HELP SUPPORT SOME ISOLATED TO SCATTERED STORMS THAT COULD TAKE ON A SUPERCELL APPEARANCE. MOST FAVORED AREAS WILL BE TOWARDS WACO TO DALLAS WITH TAIL END CELLS POSSIBLE TO SKIRT BURNET TO WILLIAMSON. QUARTER SIZED HAIL AND WIND GUSTS TO 60 MPH WILL BE PRIMARY THREATS. THIS ACTIVITY WILL WANE THROUGH THE MID EVENING HOURS AS INSTABILITY DECREASES BUT MID-LEVEL SHOWERS COULD REGENERATE LATE THURSDAY INTO FRIDAY AS AN IMPULSE MOVES OVER THE REGION FROM THE WEST. /ALLEN/ LONG TERM (FRIDAY THROUGH WEDNESDAY)... AN UNSETTLED PATTERN WILL BE IN PLACE FRIDAY THROUGH NEXT WEEK AS AREA WILL REMAIN IN SW FLOW WITH EMBEDDED IMPULSES TRAVERSING THE REGION. THERE WILL BE A CHANCE OF STRONG TO SEVERE STORMS FRIDAY AND POCKETS OF HEAVY RAIN OVER THE WEEKEND. FOR FRIDAY...THE WEAK BOUNDARY/DRYLINE WILL BE LOCATED OVER THE NORTHERN HALF OF THE REGION LEAVING SOUTHERN LOCATIONS IN A MORE UNSTABLE AIRMASS BY FRIDAY AFTERNOON. THE QUESTION FRIDAY WILL BE HOW MUCH INSTABILITY WILL OCCUR GIVEN CLOUD COVER FROM MID-LEVEL LIFT FROM A MORNING TRAVERSING IMPULSE. GLOBAL MODELS INDICATE RENEWED CONVECTION DURING THE AFTERNOON PER MASS FIELDS WHICH INCREASES CONFIDENCE OF MORE SURFACE BASED ACTIVITY. SUPPORTIVE LAPSE RATES AND SHEAR APPEAR TO BE IN PLACE FOR SOME ISOLATED STRONG TO SEVERE STORMS WITH MORE FAVORED AREA ACROSS WESTERN AND SOUTHERN ZONES. FOR THE WEEKEND...THE BOUNDARY WILL WASH OUT WITH REESTABLISHING SE LOW-LVL FLOW UNDERNEATH CONTINUED ZONAL TO SW FLOW AS EMBEDDED IMPULSES TRAVERSE THE REGION. THESE IMPULSES IN COMBINATION WITH INSTABILITY AND AT LEAST MODEST H5 WIND SPEEDS SHOULD HELP AT LEAST SCATTERED SHOWER AND THUNDERSTORM GENERATION SATURDAY AND SUNDAY AFTERNOON. THESE IMPULSES WILL BE EJECTING AHEAD OF A LARGER CUT-OFF H5 LOW ACROSS NORTHERN MEXICO THAT WILL AID IN SURFACE LOW DEVELOPMENT INTO MONDAY MORNING ACROSS NORTHERN TEXAS. FOR EARLY NEXT WEEK...THE NEGATIVELY TILTED TROUGH FROM THE MAIN LOW WILL PIVOT ACROSS THE REGION AND AID IN LIKELY CONTINUED SHOWER AND THUNDERSTORM ACTIVITY. BOTH GFS AND EC PRECIP RUN ACCUMULATION TOTALS SUGGEST POCKETS OF 4-5 INCHES THROUGH THE END OF NEXT WEEK. TRENDS WILL NEED TO MONITORED EACH DAY FOR POSSIBLE FLOODING CONCERNS IF A MORE CONCENTRATED COMPLEX DEVELOPS. /ALLEN/ && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 69 85 66 77 64 / 20 30 30 50 50 AUSTIN BERGSTROM INTL AIRPORT 68 83 66 77 64 / 20 30 30 50 50 NEW BRAUNFELS MUNI AIRPORT 68 85 67 79 65 / 20 20 10 50 50 BURNET MUNI AIRPORT 66 84 63 74 62 / 30 40 30 50 50 DEL RIO INTL AIRPORT 68 89 69 83 67 / 50 - 20 50 50 GEORGETOWN MUNI AIRPORT 68 84 64 75 63 / 30 40 40 50 50 HONDO MUNI AIRPORT 68 86 68 80 66 / 30 10 10 50 50 SAN MARCOS MUNI AIRPORT 69 84 66 78 65 / 20 20 20 50 50 LA GRANGE - FAYETTE REGIONAL 70 84 69 80 67 / 10 20 20 50 50 SAN ANTONIO INTL AIRPORT 69 85 69 79 66 / 20 10 10 50 50 STINSON MUNI AIRPORT 69 86 69 80 67 / 20 10 10 50 50 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...04 SYNOPTIC/GRIDS...17
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1152 PM CDT Wed Apr 8 2015 .AVIATION... /06Z TAFS/ Showers and thunderstorms are quickly moving out of the area with no additional activity to our west, so have removed all mention of precipitation from TAFs. As models were showing earlier, low clouds are not materializing, or are rapidly disappearing as they did around KSJT, so have removed any mention of low clouds as well. Expect this trend to hold up through the overnight hours as we are nearing the trough axis at this point, with dry air moving into the air aloft indicated by WV satellite imagery. VWP loops show increasingly westerly component to low level winds, so overall drying is expected to continue. Gusty southerly winds will continue through the rest of the overnight hours. West to southwest winds move in tomorrow morning. A cold front will drop south into the KABI area by around 00Z tomorrow evening, then KSJT and KBBD around or shortly after 03Z, but may have a hard time making the I-10 corridor before 06Z tomorrow night. && .PREV DISCUSSION... /ISSUED 942 PM CDT Wed Apr 8 2015/ DISCUSSION... Forecast has been updated to remove Severe Thunderstorm Watch 38 from all but Haskell County. Haskell County will be removed after this line of thunderstorms move through. Expecting wind gusts in the 40 mph range, but will allow the storms to move through before cancelling the watch. Have also lowered PoPs across the area somewhat as the southern end of the line of thunderstorms continues to decay as it moves east. 20 PREV DISCUSSION... /ISSUED 736 PM CDT Wed Apr 8 2015/ DISCUSSION... Have updated forecast products for Severe Thunderstorm Watch 38 in effect for areas generally west of a Haskell/Abilene/Ballinger/ San Angelo line through 1 AM. Gusts over 60 mph and hail up to the size of quarters are possible with these storms. The line should start moving into Sterling/Irion Counties between 8 and 830 PM, and into the Nolan/Fisher County area between 830 and 9 PM. 20 PREV DISCUSSION... /ISSUED 624 PM CDT Wed Apr 8 2015/ AVIATION... /00Z TAFS/ Skies have cleared, except for a blanket of mid and upper level clouds across most of west central Texas. A weakly organized broken band of thunderstorms is moving toward the west central Texas area this evening. Have these storms moving across our TAF sites roughly between 01Z(8PM) and 06Z(1AM). These storms have brought gusts of over 40 knots to areas to our west. This is likely due to very dry low layers of the atmosphere, and fast movement of the storms themselves. Will carry a mention of gusty winds to 35 knots in TEMPO groups at area sites to account for the possibility of gusty winds. Based on most recent trends (gusts to 35-40 knots), do not expect these to bring severe strength wind gusts of 50 knots or great at this time, but this cannot be ruled out. For the rest of the overnight hours, models have become much less pessimistic with respect to low clouds after 03Z(10PM) tonight, so will go with higher, but still MVFR (2500 feet) CIGS at most sites tonight beginning around 06Z(1AM). Winds will remain south to southeasterly and gusty through most of the overnight. Winds will shift to the west tomorrow between 12Z(7AM) and 15Z(10AM). 20 PREV DISCUSSION... /ISSUED 331 PM CDT Wed Apr 8 2015/ SHORT TERM... (Tonight and Tomorrow) Initial shortwave has worked itself off to the east and has taken the first round of mainly elevated convection with it. A little more potent shortwave is approaching for late this afternoon and this evening. At the surface, a fairly diffuse dryline extends across the Permian Basin northward into the Panhandle. Much sharper feature to the north where the high clouds have thinned enough to allow much better mixing and a more defined dryline. Morning soundings showed a substantial cap to overcome for surface based convection, and the abundant high clouds limiting sunshine and heating has so far not weakened the cap enough. However, as the shortwave approaches, should see the cap finally weaken enough to see at least scattered convection develop from the Permian Basin north into the South Plains, with the activity spreading into West Central Texas by sunset. How much convection we see is still a question, with the HRRR showing a fairly extensive area of storms while the TTU WRF shows quite a bit less. Given the shear and at least some instability, if storms can develop and get organized, they certainly have the potential to reach severe levels. And given a 50 kt low level jet developing during the evening, storms may be slow to dissipate through the evening and into the early morning hours. Pacific front shifts east into West Central Texas on Thursday, although perhaps not quite clearing the eastern sections by afternoon. May have enough moisture still in place for a few storms to redevelop across areas of a Brownwood to Junction line. LONG TERM... (Thursday Night through Wednesday) Rain chances will continue Thursday night over southern sections of the forecast where the frontal boundary will be located. The frontal boundary will continue to provide a focus of thunderstorm activity Friday and into the weekend as low level winds return to south and southeasterly allowing isentropic upglide across over the area. The best chance of additional rainfall will be over the southern half of the area. Winds aloft will become southwesterly ahead of an upper level low that will move across the northern Baja Peninsula Saturday night. Periodic disturbances in the flow aloft will keep the chance of thunderstorms over the area through Sunday night. Rain chances will decrease over most of the CWA from west to east on Monday as the Pacific upper low lifts northeast from extreme western Texas to the Central Plains. Residual thunderstorms will still be possible over primarily the southern CWA through Wednesday as a southwestern flow aloft reestablishes ahead of another upper level low digging southeast from the Pacific Northwest to the Central Rockies. Post-frontal afternoon temperatures on Friday will be in the lower 70s across the forecast area after Friday morning lows in 50s. Given the continuation of rainfall chances and good cloud cover through the middle of next week, warm-up will be gradual with upper 70s for Saturday highs, upper 70s and lower 80s on Sunday and Monday, and lower 80s for highs on Tuesday and Wednesday. Morning lows will climb back into the upper 50s to the lower 60s into the middle of next week. 15 && .PRELIMINARY POINT TEMPS/POPS... Abilene 66 86 55 73 60 / 20 5 10 20 40 San Angelo 66 87 57 73 61 / 10 10 10 40 40 Junction 66 85 62 75 62 / 20 20 20 40 50 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
206 AM EDT THU APR 9 2015 .SYNOPSIS... A BACK DOOR COOL FRONT OVER NORTHEAST VIRGINIA WILL CONTINUE TO EASE SOUTHWEST ACROSS THE PIEDMONT OVERNIGHT. THE BOUNDARY WILL THEN LIFT BACK TO THE NORTH THURSDAY AHEAD OF A STRONGER COLD FRONT APPROACHING FROM THE WEST. THIS FRONT WILL PUSH THROUGH FROM THE WEST FRIDAY FOLLOWED BY HIGH PRESSURE FOR THE WEEKEND. && .NEAR TERM /THROUGH TODAY/... AS OF 200 AM EDT THURSDAY... NEAR TERM UPDATES TO SHOW HIGHER POPS WITH SHOWERS AND THUNDERSTORMS LIKELY FARTHER EAST ALL THE WAY INTO PIEDMONT WITH THIS CURRENT WAVE OF CONVECTION. THUNDER MAY DIMINISH AS IT MOVES WELL OVER THE WEDGE ENTRENCHED OVER THE NORTHEAST PART OF THE AREA BUT NOT SURE IT WILL ENTIRELY SO LEFT THUNDER IN ALL THE WAY EAST THROUGH ABOUT 5 AM. LOWERED MINS IN NORTHEAST BASED ON CURRENT TEMPS OF UPPER 40S JUST TO THE NORTHEAST OF OUR AREA IN CENTRAL VA. PREV DISC AS OF 855 PM EDT WEDNESDAY... WEDNESDAY AFTERNOON CONVECTION HAS MOVED SOUTHEAST OUT OF THE FORECAST AREA. A WEAK HIGH PRESSURE CENTER WILL PROVIDE US WITH A SHORT BREAK IN THE ROUNDS OF CONVECTION THIS EVENING. ANOTHER AREA OF SHOWERS AND THUNDERSTORMS HAS DEVELOPED IN OHIO AND KENTUCKY. THIS CONVECTION WILL CONTINUE TO MOVE EASTWARD AND ROTATE ACROSS OUR REGION TONIGHT INTO THURSDAY MORNING. THE TIMING OF THIS CONVECTION APPEARS A LITTLE FASTER THAN HIRES MODELS SUGGEST. THE BETTER INSTABILITY WILL OCCUR UNTIL AROUND 02Z...THEN THE INSTABILITY WILL DECREASE AS THE SECOND AND THIRD ROUND OF STORMS APPROACH. LEANED THE POPS TOWARDS A HRRR AND RAP BLEND BECAUSE OF THE WARM ADVECTION SHOWERS NOTED ON WSR-88D IMAGES ACROSS WEST VIRGINIA. IN ADDITION TO THE SHOWERS AND THUNDERSTORMS...HIGH PRESSURE WILL CONTINUE TO BUILD IN ACROSS THE PIEDMONT FROM THE NORTHEAST THIS EVENING INTO TONIGHT...AND WILL OVERSPREAD THE MOST OF THE AREA BY DAWN. RAINFALL FROM THIS EVENING AND TONIGHT STORMS WILL MOISTEN THE LOW LEVELS OF THE ATMOSPHERE AND CREATE THE LOWER CLOUDS EXPECTED OVERNIGHT. HIGH PRESSURE WILL REMAIN IN PLACE INTO THURSDAY...KEEPING CLOUDS LOCKED INTO PLACE THROUGH MUCH OF THE DAY. INITIALLY SHAPED TEMPERATURES THIS EVENING INTO TONIGHT TOWARDS LAMP. THEN WITH THE RICH CLOUD COVER...OVERNIGHT TEMPERATURES WILL REMAIN MILD WITH READINGS FROM THE LOWER 50S IN THE MOUNTAINS TO THE UPPER 50S IN THE SOUTH. HIGHS ON THURSDAY WILL RANGE FROM THE UPPER 60S IN THE NORTH TO THE UPPER 70S IN THE SOUTH. AS OF 600 PM EDT TUESDAY... MADE SOME ADJUSTMENTS IN POPS AND WEATHER FOR THIS EVENING INTO TONIGHT...SHAPING TOWARDS WSR-88D RADAR TRENDS AND LATEST HRRR SOLUTION. ADJUSTED TEMPERATURES FOR THIS EVENING INTO TONIGHT. AS OF 415 PM EDT TUESDAY... KEEPING OUR EYES ON A SERIES OF DISTURBANCES STRETCHING FROM VIRGINIA TO THE MISSISSIPPI RIVER THIS AFTERNOON...ALL TRIGGERING THUNDERSTORM ACTIVITY AND ALL PROGGED TO RIDE A STATIONARY FRONT EASTWARD THROUGH THE EVENING AND OVERNIGHT. THE FIRST LINE OF THUNDERSTORMS IS WEAKENING AS IT ENCOUNTERS THE DOWNSLOPE FLOW IN THE VICINITY OF INTERSTATE 64. EXPECT LOCALLY GUSTY WINDS AND POCKETS OF HEAVY RAIN AS THE LINE CROSSES MOUNTAINS...BUT BELIEVE SEVERE THUNDERSTORM ACTIVITY WILL BE ISOLATED AT BEST...IF AT ALL. FURTHER WEST...THUNDERSTORM ACTIVITY DEVELOPING ACROSS CENTRAL KENTUCKY IS EXPECTED TO ENTER OUR MOUNTAIN EMPIRE COUNTIES AFTER SUNSET...AND CONVECTION DEVELOPING OVER SOUTHERN ILLINOIS IS EXPECTED TO APPROACH OUR WESTERN RIDGES BEFORE DAWN THURSDAY. INSTABILITY WILL DECREASE AS THE SECOND AND THIRD ROUND OF STORMS APPROACH...SO BELIEVE THE THREAT FOR SEVERE STORMS THIS EVENING AND TONIGHT REMAINS REMOTE. IN ADDITION TO STORMS...HIGH PRESSURE CONTINUES TO BUILD IN ACROSS THE PIEDMONT FROM THE NORTHEAST THIS AFTERNOON...AND WILL OVERSPREAD THE MOST OF THE AREA BY DAWN. BELIEVE THAT RAINFALL ENTERING THE AREA THIS EVENING AND TONIGHT WILL MOISTEN THE LOW LEVELS OF THE ATMOSPHERE AND HELP TO STRENGTHEN THE HIGH PRESSURE AS IT BUILDS IN...WHICH WILL MAKE FOR WIDESPREAD CLOUD COVER OVERNIGHT. HIGH PRESSURE WILL REMAIN IN PLACE INTO THURSDAY...KEEPING CLOUDS LOCKED INTO PLACE THROUGH MUCH OF THE DAY. CLOUDS WILL MAINTAIN MILD TEMPERATURES THROUGH THE NIGHT...HOLDING OVERNIGHT LOWS IN THE MID AND UPPER 50S. WILL STICK TO THE COOL SIDE OF GUIDANCE FOR HIGH TEMPERATURES ON THURSDAY...HOLDING HIGHS IN THE LOW AND MID 70S FOR MUCH OF THE AREA. BELIEVE THAT TEMPERATURES WILL REMAIN COOL THROUGH MID AFTERNOON DUE TO THE MORE WIDESPREAD NATURE OF THE CLOUD COVER...AND THEN SEE A LATE DAY UPWARD SPIKE IN TEMPERATURES AS CLOUDS BEGIN TO BREAK UP DURING MAX AFTERNOON HEATING. && .SHORT TERM /TONIGHT THROUGH SATURDAY/... AS OF 400 PM EDT WEDNESDAY... STRONG SHORT WAVE OVER THE UPPER MID WEST WILL MOVE EAST THURSDAY NIGHT AND FRIDAY. THURSDAY NIGHT THE SURFACE LOW MOVES NORTHEAST ACROSS THE GREAT LAKES...THEN ON FRIDAY TRACKS INTO SOUTHERN ONTARIO. ANY REMNANTS OF THE SURFACE WEDGE AND MORE STABLE AIR MASS IN THE NORTHEAST COUNTY WARNING AREA WILL BE GONE ON THURSDAY EVENING. TIMING HAS BEEN CONSISTENT IN THE MODELS BRINGING THE ASSOCIATED COLD FRONT THROUGH A BULK OF THE COUNTY WARNING AREA ON FRIDAY. MODELS WERE FORECASTING BEST INSTABILITY AHEAD OF THE FRONT IN THE PIEDMONT ALONG THE EASTERN EDGE OF THE FORECAST AREA ON FRIDAY AFTERNOON...WITH CAPES OF AS HIGH AS 2000 J/KG POSSIBLE. WILL MAINTAIN MENTION OF SEVERE WEATHER THREAT IN THE HAZARDOUS WEATHER OUTLOOK. 12Z MODELS WERE VERY SIMILAR WITH THE TIMING OF THE FRONT ON FRIDAY. WILL MAKE SLIGHT ADJUSTMENTS TO THE LOCATION BETWEEN 18Z/2PM FRIDAY AND 00Z SATURDAY/8PM FRIDAY WITH A HIGHER PROBABILITY OF RAIN. MORE CHALLENGING TO TELL HOW MUCH COVERAGE OF SHOWERS AND THUNDERSTORMS THERE WILL BE AHEAD OF THE FRONT THURSDAY NIGHT. HAVE ALSO REMOVED THE RAIN BEHIND THE FRONT FOR LATE FRIDAY NIGHT AND SATURDAY. WILL BE TRENDING TOWARD WARMER GUIDANCE AHEAD OF THE FRONT FOR LOWS ON THURSDAY NIGHT. WILL BE STARTING MILD ON FRIDAY BUT LIMITED HEATING DURING THE MORNING OVER THE MOUNTAINS WHICH WILL HOLD TEMPERATURES IN THE 60S. IN THE EAST WHERE THE FRONT COMES THROUGH LATER...TEMPERATURES WILL RISE WELL INTO THE 70S. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 200 PM EDT WEDNESDAY... SECOND PIECE OF ENERGY COMES THROUGH THE NORTHEASTERN TROF ON SATURDAY SO THE 500 MB LONG WAVE TROF DOES NOT MOVE EAST OF THE FORECAST AREA UNTIL SUNDAY MORNING. THEN PATTERN RETURNS TO RIDGING IN THE EAST AND TROFING THE WEST FOR THE REST OF THE PERIOD. HEIGHTS AT 500 MB BECOME MORE AMPLIFIED BY MONDAY AND TUESDAY. WITH A DEEP CLOSED LOW IN THE WEST MONDAY THROUGH WEDNESDAY...FORECAST AREA WILL BE IN BROAD SOUTHWEST FLOW WITH A SERIES OF SHORT WAVES TRACKING OUT OF THE SOUTHERN PLAINS. AT THE SURFACE A SECONDARY FRONT CROSSES THE NORTHEAST SATURDAY NIGHT BUT LOOKS FAIRLY WEAK BY THE TIME IT REACHES THE CENTRAL APPALACHIANS. WPC CONSIDERED NORTH AMERICAN AND GFS ENSEMBLES AS REASONABLE FOR THE UPPER AND SURFACE TIMING AND LOCATION OF FEATURES FOR THIS TIME FRAME. HIGH PRESSURE BUILDS IN FOLLOWING THE FRONT AND WILL BE CENTERED OVER THE FORECAST AREA ON SUNDAY MORNING. THE HIGH WILL BE OFFSHORE BY MONDAY AFTERNOON. WARM...MOIST AIR WILL BE IN PLACE ON TUESDAY AND WEDNESDAY. APPEARS THERE WILL BE NO ORGANIZED LIFTING MECHANISM TO GENERATE PRECIPITATION BUT ANY DECENT SHORT WAVE SHOULD BE ABLE TO TRIGGER AT LEAST AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. AFTER TEMPERATURES DROP BEHIND THE FRONT ON FRIDAY...850 MB VALUES REBOUND MONDAY THROUGH WEDNESDAY. MODELS HOLD RESIDUAL LOW LEVEL MOISTURE IN THE WESTERN UPSLOPE AREAS THROUGH SATURDAY MORNING. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 205 AM EDT THURSDAY... DEALING WITH ANOTHER WAVE OF SHWRS AND THUNDERSTORMS MOVING THROUGH OVERNIGHT ACROSS THE NORTHERN HALF OF THE AREA...ALTHOUGH A FEW SHWRS MAY GET DOWN TO DANVILLE AFTER 08 UTC. WEDGE FRONT DOWN INTO NORTHERN NC AND INTO NEW RIVER VALLEY AREA AS WELL...WITH IFR CONDITIONS AT LYH...AND BEHIND THIS WAVE OF SHWRS AND STORMS SHOULD LOWER TO IFR AT ROA...BCB...AND EVENTUALLY DAN. MAY BE TOO AGGRESSIVE WITH THIS IN CURRENT TAFS BUT CONFIDENCE HIGH WE`LL SEE IFR BEFORE DAWN AT ALL THESE AIRPORTS. KEPT IT MVFR AT LWB AND BLF BUT LOWER CONF THERE. COULD REMAIN VFR AT BLF WITH OCCASSIONAL SHOWERS OR STRAY TSTORM OVERNIGHT. HIGH PRESSURE IS EXPECTED TO MAINTAIN ITS HOLD ON THURSDAY...WITH LOW CEILINGS LINGERING ACROSS MUCH OF THE AREA INTO MID AFTERNOON. WITH BETTER INSTABILITY ALONG THE CONTINENTAL DIVIDE WHERE HIGH PRESSURE HAS LESS INFLUENCE...MAY SEE A FEW SHOWERS AND ISOLATED THUNDERSTORMS DEVELOP BY LATE AFTERNOON IN MAXIMUM HEATING. EXTENDED AVIATION DISCUSSION... PROLONGED PERIOD OF MVFR CONDITIONS LOOKS IN ORDER INTO FRIDAY WITH A COLD FRONTAL PASSAGE EXPECTED LATER FRIDAY. COLD FRONT EXPECTED TO CLEAR THE REGION FRIDAY NIGHT-SATURDAY MORNING WITH ANY SHOWERS SUBSIDING...THOUGH SOME UPSLOPE MVFR CEILINGS MAY LINGER INTO SATURDAY AT KBLF/KLWB. WIDESPREAD VFR THEN RETURNS SATURDAY NIGHT AND SUNDAY UNDER HIGH PRESSURE BEHIND THE FRONT. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...NF NEAR TERM...KK/NF/SK SHORT TERM...AMS LONG TERM...AMS AVIATION...KK/NF/SK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 PM CDT THU APR 9 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 350 PM CDT THU APR 9 2015 TWO AREAS OF CONCERN TONIGHT FOR PRECIPITATION. THE FIRST WILL BE EARLY THIS EVENING ACROSS THE FAR SOUTH AS THE SURFACE LOW PASSES BY THE REGION. THE LATEST INDICATIONS CONTINUE TO POINT TO THE SURFACE LOW TRACKING JUST SOUTH OF THE AREA AS IT COMES OUT OF EASTERN IOWA INTO SOUTH CENTRAL WISCONSIN. ON THIS PATH...THE WARM SECTOR AND THE BEST SUPPORT FOR SEVERE WEATHER WILL REMAIN OUTSIDE OF THE FORECAST AREA. LOOKING AT THE TRENDS IN THE 09.19Z RAP AND HRRR...THE CONVECTION THAT DEVELOPS AHEAD OF THE SURFACE LOW LATE THIS AFTERNOON COULD POSSIBLY CLIP GRANT COUNTY BUT SHOULD BE TO THE EAST OF THE AREA BY 00Z. BASED ON THIS SCENARIO...WILL ONLY SHOW ABOUT A 50 PERCENT CHANCE FOR SHOWERS AND STORMS ACROSS THE FAR SOUTHERN SECTIONS FOR EARLY THIS EVENING. THE OTHER AREA OF CONCERN WILL BE IN THE DEFORMATION AREA ON THE BACK SIDE OF THE SURFACE LOW. THIS AREA LOOKS TO HAVE SOME PRETTY GOOD FORCING IN IT THIS EVENING AS THE SHORT WAVE TROUGH...CURRENTLY OVER THE MISSOURI RIVER VALLEY...CONTINUES TO MOVE NORTHEAST AND TAKES ON A NEGATIVE TILT. THIS WILL ALLOW FOR A QUICK SHOT OF STRONG PV ADVECTION TO OCCUR IN THE 500-300 MB LAYER. THERE IS A GOOD LOW LEVEL BAROCLINIC ZONE IN PLACE WITH TEMPERATURES IN THE 30S AND 40S ON THE COOL SIDE OF THE LOW AND IN THE 60S AND 70S IN THE WARM SECTOR. BOTH THE 09.12Z NAM AND GFS SHOW MODERATE TO STRONG FRONTOGENESIS OCCURRING IN THE DEFORMATION ZONE WITH THIS BEING THE STRONGEST IN THE 750-650 MB LAYER. THIS FRONTOGENESIS LOOKS TO SIT UNDERNEATH AN AREA OF STRONG UPPER LEVEL DIVERGENCE FROM A COUPLED UPPER LEVEL JET STRUCTURE. THE NAM SUGGESTS THIS SYSTEM SHOULD GET STRONG ENOUGH TO WRAP THE WARM CONVEYOR BELT AROUND THE LOW TO PRODUCE 4-6 UBAR/S OF ISENTROPIC UP GLIDE ON THE 295K SURFACE THIS EVENING IN THE SAME GENERAL AREA AS THE FRONTOGENESIS. LOOKS LIKE THE DEFORMATION PRECIPITATION IS ALREADY STARTING TO FORM ACROSS SOUTHEAST MINNESOTA AND EXPECT THIS WILL CONTINUE TO GROW AS THE FORCING INCREASES THIS EVENING. WHEN THE STRONGEST FORCING OCCURS...THIS SHOULD BE ENOUGH TO PRODUCE SOME HIGH PRECIPITATION RATES TO ALLOW FOR A CHANGE OVER TO ALL SNOW DESPITE SOME WARM LOW LEVEL BOUNDARY TEMPERATURES. THE BEST CHANCES FOR THIS TO OCCUR THIS EVENING WILL BE FROM SOUTHEAST MINNESOTA INTO NORTH CENTRAL WISCONSIN. THE DURATION OF THIS SHOULD NOT BE VERY LONG OVER SOUTHEAST MINNESOTA...BUT THE SNOW COULD PERSIST INTO THE OVERNIGHT HOURS FOR NORTH CENTRAL MINNESOTA. THIS COULD LEAD TO ACCUMULATIONS OF 2 TO 3 INCHES ACROSS TAYLOR COUNTY AND WILL ISSUE A WINTER WEATHER ADVISORY TO HANDLE THIS. A SECONDARY SHORT WAVE TROUGH WILL DROP ACROSS THE AREA THURSDAY. IT LOOKS LIKE A LOT OF THE DEEP MOISTURE WILL GET SCOURED OUT BEHIND THE MAIN SHORT WAVE TROUGH BUT STILL EXPECT THAT THIS WAVE WILL BE STRONG ENOUGH TO PRODUCE SOME LIGHT PRECIPITATION FOR AREAS ALONG AND EAST OF THE MISSISSIPPI RIVER FROM LATE MORNING THROUGH THE AFTERNOON. HIGH PRESSURE THEN LOOKS TO BUILD IN BEHIND THIS SYSTEM AND DRIFT ACROSS THE REGION TO KEEP THE FRIDAY NIGHT THROUGH SATURDAY NIGHT PERIOD DRY. .LONG TERM...(SUNDAY THROUGH THURSDAY) ISSUED AT 350 PM CDT THU APR 9 2015 THE MODELS ARE ALL IN GOOD AGREEMENT OF ANOTHER SHORT WAVE TROUGH COMING ACROSS THE UPPER MIDWEST FOR SUNDAY AND SUNDAY NIGHT. THIS IS EXPECTED TO PUSH A COLD FRONT ACROSS THE REGION WHICH SHOULD BE ACCOMPANIED BY A LINE OF SHOWERS AND STORMS. SOME DIFFERENCES BETWEEN THE 09.12Z GFS AND ECMWF ON HOW FAST THIS ACTIVITY MOVES IN SUNDAY WITH THE GFS QUICKER TO BRING IT IN THAN THE ECMWF. WILL ATTEMPT TO RESOLVE THESE DIFFERENCES WITH LATER FORECASTS ONCE THE SHORT TERM WEATHER QUIETS DOWN. THE MODELS ALSO ARE IN GOOD AGREEMENT FOR LATER IN THE PERIOD BRINGING ANOTHER SYSTEM INTO THE CENTRAL PART OF THE COUNTRY FOR LATE IN THE PERIOD. WITH THE SOUTHWEST FLOW AHEAD OF THIS SYSTEM...COULD SEE SOME ACTIVITY FORM AS EARLY AS TUESDAY NIGHT AND THEN CONTINUE OFF AND ON THROUGH THURSDAY. HAVE LET THE MODEL CONSENSUS GRIDS RIDE WITH THIS SYSTEM WITH GENERAL 30 TO 40 PERCENT CHANCES. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 600 PM CDT THU APR 9 2015 CIGS: 1 KFT OR LOWER CIGS SHOULD HOLD ACROSS THE AREA INTO THE EARLY OVERNIGHT HOURS...BUT SATELLITE TRENDS/RH FIELDS/BUFKIT SOUNDINGS SUGGEST THE BACKEDGE OF THE LOW CLOUD DECK WILL SWEEP THROUGH IN THE 08-10Z WINDOW. A BRIEF PERIOD OF VFR COULD OCCUR BEFORE AN UPPER LEVEL SHORTWAVE TROUGH TRACKS ACROSS THE AREA LATE FRI MORNING- AFTERNOON. MVFR CIGS LOOK LIKELY. WINDS: WINDS ARE GOING TO INCREASE AND COULD BE GUSTY THIS EVENING AS A LOW PRESSURE SYSTEM TRACKS JUST TO THE SOUTH OF KRST/KLSE. SHOULD SEE SOME DECREASE IN SPEEDS TOWARD 12Z FRI...BUT WINDS WILL STAY +10 KTS THROUGH THE DAY FRI. WX/VSBY: DEFORMATION REGION OF A STORM SYSTEM WILL KEEP THE AREA UNDER SHOWERS THIS EVENING INTO THE OVERNIGHT. PERHAPS AN ISOLATED STORM...BUT MOST OF THE INSTABILITY STAYS SOUTH...AND CHANCES LOOK SMALL ENOUGH TO NOT INCLUDE IN THE FORECAST FOR NOW. EXPECTING SOME VSBY RESTRICTIONS FROM TIME TO TIME...BUT LATEST OBS ARE RATHER VARIABLE WITHIN AND OUTSIDE OF THE RAIN SHIELD...LOWERING CONFIDENCE A BIT. ANOTHER ROUND OF SCATTERED -SHRA IS LIKELY FROM LATE MORNING INTO THE AFTERNOON FRIDAY AS A SHORTWAVE PASSES ACROSS THE AREA. COULD HAVE SOME DIP INTO MVFR VSBYS WITH THE SHOWERS...BUT MOSTLY P6SM. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 7 AM CDT FRIDAY FOR WIZ017. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...RIECK
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
550 PM CDT THU APR 9 2015 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE AND NEW INFORMATION ADDED TO UPDATE SECTION .UPDATE... ISSUED AT 536 PM CDT THU APR 9 2015 FCST ISSUES SPAN THE SEASONS THIS EVENING AS STRENGTHENING CYCLONE LIFTS NEWD FM IA. CLUSTER OF SVR STORMS IN S-C WI HEADING NE. LOCAL MESO PLOTS SHOW POOL OF INSTABILITY EXPANDING NE...BUT NOT AS QUICKLY AS THE STORMS ARE MOVG NE. IT/S GOING TO BE A CLOSE CALL ON WHETHER A SVR STORM COULD CLIP THE SRN PART OF THE FCST AREA BEFORE WEAKENING. THE PRIMARY SVR THREAT WOULD BE HAIL...AND THINK THAT WOULD NEED TO HAPPEN WITHIN THE NEXT COUPLE HRS...BEFORE PCPN GETS TOO WIDESPREAD. IT/S A COMPLETELY DIFFERENT SITN ACRS THE NW CORNER OF THE FCST AREA...WHERE THE THREAT IS HEAVY SNOW. WATCHING THE UPR DEFORMATION ZONE EXPAND NEWD AS MAIN SHRTWV EJECTS TOWARD WI. EXTRAOLATION OF SRN EDGE OF THE DEFORMATION ZONE WOULD BRING IT ACRS THE NW PART OF THE FCST AREA. MAIN QUESTIONS FOR SNOW AMNTS CONTINUE TO BE TIMING OF THE CHANGEOVER AND HOW MUCH PCPN FALLS AFTER THAT TIME. NRN STREAM SHRTWV EDGING IN FM THE NW MAY TEND TO DISRUPT THE COMMA HEAD AND NUDGE IT EWD...LIMITING THE AMNT OF PCPN THAT FALLS AFTER THE CHANGEOVER. ON THE OTHER HAND...PCPN COULD BE FALLING QUITE HEAVILY AFTER THE CHANGEOVER...SO THE POTENTIAL IS THERE FOR A PERIOD OF HEAVY SNOW. NEED TO WATCH THIS VERY CLOSELY...BUT LIKELY WON/T BE ABLE TO MAKE ANY HEADLINE CHANGES UNTIL WE START TO SEE THE CHANGEOVER OCCURRING. && .SHORT TERM...TONIGHT AND FRIDAY ISSUED AT 241 PM CDT THU APR 9 2015 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE HEADING NORTHEAST AS IT ENTERS SOUTH-CENTRAL IOWA EARLY THIS AFTERNOON. COMMA HEAD PRECIPITATION IS OCCURRING JUST TO THE REAR OF THE PRIMARY SHORTWAVE LOCATED OVER CENTRAL NEBRASKA...WHERE HEAVY SNOW AND A FEW LIGHTNING STRIKES HAVE BEEN DETECTED. DOWNSTREAM OF THE SYSTEM...A SHORTWAVE IMPULSE IS GENERATING SHOWERS AND THUNDERSTORMS OVER THE EASTERN HALF OF WISCONSIN. MOST OF THE THUNDERSTORM ACTIVITY HAS DIMINISHED AS THEY REACHED THE WAUTOMA TO MANITOWOC CORRIDOR SINCE ELEVATED INSTABILITY HAS NOT BEEN ABLE TO EXTEND THAT FAR NORTH. AS A RESULT...LOOK FOR PERIODS OF SHOWERS AND DRIZZLE TO CONTINUE TO IMPACT THE REGION FOR THE REST OF THE AFTERNOON. THE MAIN FORECAST CONCERNS REVOLVE AROUND HEAVY WINTRY PRECIP ACROSS THE NORTH AND THUNDERSTORM CHANCES OVER THE SOUTH AS A CYCLONE PASSES ACROSS THE REGION TONIGHT. TONIGHT...THE STRONG SHORTWAVE OVER NEBRASKA WILL SWING NORTHEAST AS IT PUSHES A SURFACE LOW FROM THE NORTHWEST CORNER OF ILLINOIS TO CENTRAL LAKE MICHIGAN TO THE STRAITS OF MACKINAC. AHEAD OF THE LOW...ELEVATED INSTABILITY UP TO 500 J/KG MAY SNEAK INTO EAST-CENTRAL WISCONSIN WITHIN A REGION OF STRONG UPWARD MOTION WHICH COULD GENERATE SCATTERED THUNDERSTORMS THOUGH AROUND MID-EVENING. IF THUNDERSTORMS DO OCCUR...SMALL HAIL WILL BE POSSIBLE. TO THE NORTH OF THE LOW...EXCELLENT UPPER DIVERGENCE COMBINED WITH STRONG MID-LEVEL FGEN AND REDUCED STABILITY WILL LEAD TO A HEALTHY DEFORMATION BAND DEVELOPING FROM WEST-CENTRAL TO NORTH-CENTRAL WISCONSIN. THIS DEFORMATION BAND WILL BRING A PROLONGED PERIOD OF MODERATE TO HEAVY PRECIP AT TIMES. WITH TEMPS AND DEWPOINTS IN THE MIDDLE 30S AT THE START OF THE EVENING...PRECIP WILL LIKELY BE ALL RAIN FOR THE FIRST COUPLE HOURS. THEN COLDER AIR WILL GRADUALLY GET DRAWN INTO NORTH-CENTRAL WISCONSIN TO CHANGE PRECIP TO SLEET AND THEN SNOW. BUFKIT SOUNDINGS INDICATE THAT THE NORTH COULD SEE A FEW HOUR PERIOD OF SLEET WHICH COULD LEAD TO DECENT SLEET ACCUMULATIONS GIVEN THE EXPECTED PRECIP RATES. THEN ONCE TEMPS COOL ENOUGH FOR ALL SNOW...SNOWFALL RATES COULD EASILY EXCEED AN INCH PER HOUR AT TIMES. BUT ONE OF THE MOST DIFFICULT ASPECTS OF THIS FORECAST IS IN REGARDS TO HOW QUICKLY THIS CHANGE OVER OCCURS SINCE COLD AIR IS NOT THAT PLENTIFUL TO OUR NORTH. BEST GUESS FROM GUIDANCE INDICATES THIS CHANGE OVER WILL OCCUR LATE THIS EVENING OVER N-C WISCONSIN AND EARLY OVERNIGHT OVER TO CENTRAL WISCONSIN TO THE IRON MOUNTAIN AREA. THE INITIAL RAIN AND SLEET WILL EAT UP SOME OF THE QPF AMOUNTS THIS EVENING...BUT GUIDANCE STILL POINT TOWARDS OVER A HALF INCH FALLING AFTER 06Z. ADDITIONALLY...THE HI-RES MODELS ARE ALSO INDICATING BANDING TAKING PLACE...AND A LITTLE FARTHER TO THE EAST THAN SHOWN PREVIOUSLY. HAVE SHIFTED QPF AND SNOW AMOUNTS TO THE EAST AS A RESULT...WHICH GIVES SNOW AMOUNTS OF 3-6 INCHES FROM LINCOLN AND LANGLADE ON NORTH. A QUARTER TO A HALF INCH OF THAT COULD TURN OUT TO BE SLEET ACCUMULATION. LOCALLY HIGHER AMOUNTS WILL BE POSSIBLE DEPENDING ON WHERE THE SNOW BANDS SET UP. BECAUSE OF THIS UNCERTAINTY...WILL ISSUE A WINTER WEATHER ADVISORY FROM 02Z-13Z. FRIDAY...PRECIP WITH SNOW WEST OF THE FOX VALLEY AND RAIN TO THE EAST WILL DIMINISH EARLY FRIDAY MORNING. SHOULD SEE A CLOUDY AND WINDY START TO THE DAY OTHERWISE. A TRAILING SHORTWAVE WILL PUSH ACROSS SOUTHERN WISCONSIN DURING THE AFTERNOON WHICH COULD CREATE AN ISOLATED SHOWER OVER THE NORTHERN HALF OF THE STATE. LEFT A SMALL CHANCE TO ACCOUNT FOR THIS. HIGHS RANGING FROM THE LOW 40S NORTH TO LOW 50S SOUTH. .LONG TERM...FRIDAY NIGHT THROUGH THURSDAY ISSUED AT 241 PM CDT THU APR 9 2015 PCPN TRENDS SUNDAY/SUNDAY NIGHT AND DURING THE MIDDLE OF NEXT WEEK ARE THE MAIN FCST CONCERNS. HIGH PRESSURE IS EXPECTED TO BUILD INTO THE REGION FRIDAY NIGHT. USED A BLEND OF THE BETTER PERFORMING GUIDANCE SETS FOR MIN TEMPS...BUT WITH THE POTENTIAL FOR A LINGERING SNOW COVER OVER NC WI...HAVE BUMPED MIN TEMPS DOWN THERE. HIGH PRESSURE WILL BRING DRY CONDITIONS SATURDAY AND SATURDAY NIGHT... WITH DEVELOPING SOUTH FLOW RESULTING IN MODERATING TEMPERATURES. A COLD FRONT WILL MOVE INTO WESTERN WI ON SUNDAY AFTERNOON...THEN ACROSS THE FORECAST AREA SUNDAY EVENING. HAVE SLOWED DOWN THE ARRIVAL TIME OF SHOWERS ON SUNDAY AFTERNOON (MAINLY NC/C WI LATE IN THE DAY)...BUT WILL SPREAD HIGH CHC/LOW LIKELY POPS OVER THE ENTIRE CWA SUNDAY NIGHT. H8 LI`S SLIGHTLY BLO ZERO AND STEEP MID- LEVEL LAPSE RATES SUGGEST POTENTIAL FOR AT LEAST ISOLD TSTMS...SO HAVE INCLUDED A SLGT CHC OF TSTMS. HIGH PRESSURE AND AND ASSOCIATED DRY AND MILD CONDITIONS WILL RETURN TO WISCONSIN ON MONDAY AND TUESDAY. THE FCST BECOMES A BIT MUDDLED DURING THE MIDDLE OF THE WEEK...AS SW FLOW ALOFT DEVELOPS AND LOW PRESSURE AND AN ASSOCIATED COLD FRONT EDGE TOWARD THE WESTERN GREAT LAKES. MOST MODELS NOW KEEP TUESDAY NIGHT DRY...WITH THE ECMWF BRINGING PCPN INTO THE REGION ON WEDS...AND THE GFS HOLDING OFF UNTIL ABOUT THURSDAY. GIVEN THE UNCERTAINTY...WILL CARRY CHC POPS THROUGH THIS PERIOD. THE GOOD NEWS IS THAT ANY PCPN THAT OCCURS SHOULD FALL AS ALL RAIN...WHICH IS DEFINITELY A STEP IN THE RIGHT DIRECTION. && .AVIATION...FOR 00Z TAF ISSUANCE ISSUED AT 536 PM CDT THU APR 9 2015 WL CARRY THUNDER OVER THE SRN 1/2 OF THE FCST AREA FOR A FEW HRS THIS EVENING. VERY POOR FLIGHT CONDITIONS DURING THE FIRST PORTION OF THE TAF PERIOD WL GRADUALLY IMPROVE FRIDAY AS THE CYCLONE PULLS AWAY FM THE REGION. && .GRB WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM CDT FRIDAY FOR WIZ011-012-019. WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 10 AM CDT FRIDAY FOR WIZ005-010-018. && $$ UPDATE.........SKOWRONSKI SHORT TERM.....MPC LONG TERM......KIECKBUSCH AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
350 PM CDT THU APR 9 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 350 PM CDT THU APR 9 2015 TWO AREAS OF CONCERN TONIGHT FOR PRECIPITATION. THE FIRST WILL BE EARLY THIS EVENING ACROSS THE FAR SOUTH AS THE SURFACE LOW PASSES BY THE REGION. THE LATEST INDICATIONS CONTINUE TO POINT TO THE SURFACE LOW TRACKING JUST SOUTH OF THE AREA AS IT COMES OUT OF EASTERN IOWA INTO SOUTH CENTRAL WISCONSIN. ON THIS PATH...THE WARM SECTOR AND THE BEST SUPPORT FOR SEVERE WEATHER WILL REMAIN OUTSIDE OF THE FORECAST AREA. LOOKING AT THE TRENDS IN THE 09.19Z RAP AND HRRR...THE CONVECTION THAT DEVELOPS AHEAD OF THE SURFACE LOW LATE THIS AFTERNOON COULD POSSIBLY CLIP GRANT COUNTY BUT SHOULD BE TO THE EAST OF THE AREA BY 00Z. BASED ON THIS SCENARIO...WILL ONLY SHOW ABOUT A 50 PERCENT CHANCE FOR SHOWERS AND STORMS ACROSS THE FAR SOUTHERN SECTIONS FOR EARLY THIS EVENING. THE OTHER AREA OF CONCERN WILL BE IN THE DEFORMATION AREA ON THE BACK SIDE OF THE SURFACE LOW. THIS AREA LOOKS TO HAVE SOME PRETTY GOOD FORCING IN IT THIS EVENING AS THE SHORT WAVE TROUGH...CURRENTLY OVER THE MISSOURI RIVER VALLEY...CONTINUES TO MOVE NORTHEAST AND TAKES ON A NEGATIVE TILT. THIS WILL ALLOW FOR A QUICK SHOT OF STRONG PV ADVECTION TO OCCUR IN THE 500-300 MB LAYER. THERE IS A GOOD LOW LEVEL BAROCLINIC ZONE IN PLACE WITH TEMPERATURES IN THE 30S AND 40S ON THE COOL SIDE OF THE LOW AND IN THE 60S AND 70S IN THE WARM SECTOR. BOTH THE 09.12Z NAM AND GFS SHOW MODERATE TO STRONG FRONTOGENESIS OCCURRING IN THE DEFORMATION ZONE WITH THIS BEING THE STRONGEST IN THE 750-650 MB LAYER. THIS FRONTOGENESIS LOOKS TO SIT UNDERNEATH AN AREA OF STRONG UPPER LEVEL DIVERGENCE FROM A COUPLED UPPER LEVEL JET STRUCTURE. THE NAM SUGGESTS THIS SYSTEM SHOULD GET STRONG ENOUGH TO WRAP THE WARM CONVEYOR BELT AROUND THE LOW TO PRODUCE 4-6 UBAR/S OF ISENTROPIC UP GLIDE ON THE 295K SURFACE THIS EVENING IN THE SAME GENERAL AREA AS THE FRONTOGENESIS. LOOKS LIKE THE DEFORMATION PRECIPITATION IS ALREADY STARTING TO FORM ACROSS SOUTHEAST MINNESOTA AND EXPECT THIS WILL CONTINUE TO GROW AS THE FORCING INCREASES THIS EVENING. WHEN THE STRONGEST FORCING OCCURS...THIS SHOULD BE ENOUGH TO PRODUCE SOME HIGH PRECIPITATION RATES TO ALLOW FOR A CHANGE OVER TO ALL SNOW DESPITE SOME WARM LOW LEVEL BOUNDARY TEMPERATURES. THE BEST CHANCES FOR THIS TO OCCUR THIS EVENING WILL BE FROM SOUTHEAST MINNESOTA INTO NORTH CENTRAL WISCONSIN. THE DURATION OF THIS SHOULD NOT BE VERY LONG OVER SOUTHEAST MINNESOTA...BUT THE SNOW COULD PERSIST INTO THE OVERNIGHT HOURS FOR NORTH CENTRAL MINNESOTA. THIS COULD LEAD TO ACCUMULATIONS OF 2 TO 3 INCHES ACROSS TAYLOR COUNTY AND WILL ISSUE A WINTER WEATHER ADVISORY TO HANDLE THIS. A SECONDARY SHORT WAVE TROUGH WILL DROP ACROSS THE AREA THURSDAY. IT LOOKS LIKE A LOT OF THE DEEP MOISTURE WILL GET SCOURED OUT BEHIND THE MAIN SHORT WAVE TROUGH BUT STILL EXPECT THAT THIS WAVE WILL BE STRONG ENOUGH TO PRODUCE SOME LIGHT PRECIPITATION FOR AREAS ALONG AND EAST OF THE MISSISSIPPI RIVER FROM LATE MORNING THROUGH THE AFTERNOON. HIGH PRESSURE THEN LOOKS TO BUILD IN BEHIND THIS SYSTEM AND DRIFT ACROSS THE REGION TO KEEP THE FRIDAY NIGHT THROUGH SATURDAY NIGHT PERIOD DRY. .LONG TERM...(SUNDAY THROUGH THURSDAY) ISSUED AT 350 PM CDT THU APR 9 2015 THE MODELS ARE ALL IN GOOD AGREEMENT OF ANOTHER SHORT WAVE TROUGH COMING ACROSS THE UPPER MIDWEST FOR SUNDAY AND SUNDAY NIGHT. THIS IS EXPECTED TO PUSH A COLD FRONT ACROSS THE REGION WHICH SHOULD BE ACCOMPANIED BY A LINE OF SHOWERS AND STORMS. SOME DIFFERENCES BETWEEN THE 09.12Z GFS AND ECMWF ON HOW FAST THIS ACTIVITY MOVES IN SUNDAY WITH THE GFS QUICKER TO BRING IT IN THAN THE ECMWF. WILL ATTEMPT TO RESOLVE THESE DIFFERENCES WITH LATER FORECASTS ONCE THE SHORT TERM WEATHER QUIETS DOWN. THE MODELS ALSO ARE IN GOOD AGREEMENT FOR LATER IN THE PERIOD BRINGING ANOTHER SYSTEM INTO THE CENTRAL PART OF THE COUNTRY FOR LATE IN THE PERIOD. WITH THE SOUTHWEST FLOW AHEAD OF THIS SYSTEM...COULD SEE SOME ACTIVITY FORM AS EARLY AS TUESDAY NIGHT AND THEN CONTINUE OFF AND ON THROUGH THURSDAY. HAVE LET THE MODEL CONSENSUS GRIDS RIDE WITH THIS SYSTEM WITH GENERAL 30 TO 40 PERCENT CHANCES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1242 PM CDT THU APR 9 2015 PERIODS OF IFR AND LIFR CONDITIONS ALONG WITH SHOWERS AND THUNDERSTORMS ARE EXPECTED LATE THIS AFTERNOON INTO EARLY THIS EVENING AS A STRONG LOW PRESSURE SYSTEM LIFTS NORTHEAST ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. LOOK FOR WINDS TO INCREASE OUT OF THE NORTHEAST AS THE LOW APPROACHES LATE THIS AFTERNOON THEN TURN NORTHWEST AS THE LOW MOVES TO THE NORTHEAST OF THE REGION. LOOK FOR NORTHWEST WINDS TO INCREASE TO 18 TO 23 KTS TONIGHT WITH GUSTS OF AROUND 35 KTS POSSIBLE. MVFR CONDITIONS WILL RETURN LATE TONIGHT INTO EARLY FRIDAY MORNING. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 7 AM CDT FRIDAY FOR WIZ017. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...WETENKAMP
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND FRIDAY ISSUED AT 241 PM CDT THU APR 9 2015 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE HEADING NORTHEAST AS IT ENTERS SOUTH-CENTRAL IOWA EARLY THIS AFTERNOON. COMMA HEAD PRECIPITATION IS OCCURRING JUST TO THE REAR OF THE PRIMARY SHORTWAVE LOCATED OVER CENTRAL NEBRASKA...WHERE HEAVY SNOW AND A FEW LIGHTNING STRIKES HAVE BEEN DETECTED. DOWNSTREAM OF THE SYSTEM...A SHORTWAVE IMPULSE IS GENERATING SHOWERS AND THUNDERSTORMS OVER THE EASTERN HALF OF WISCONSIN. MOST OF THE THUNDERSTORM ACTIVITY HAS DIMINISHED AS THEY REACHED THE WAUTOMA TO MANITOWOC CORRIDOR SINCE ELEVATED INSTABILITY HAS NOT BEEN ABLE TO EXTEND THAT FAR NORTH. AS A RESULT...LOOK FOR PERIODS OF SHOWERS AND DRIZZLE TO CONTINUE TO IMPACT THE REGION FOR THE REST OF THE AFTERNOON. THE MAIN FORECAST CONCERNS REVOLVE AROUND HEAVY WINTRY PRECIP ACROSS THE NORTH AND THUNDERSTORM CHANCES OVER THE SOUTH AS A CYCLONE PASSES ACROSS THE REGION TONIGHT. TONIGHT...THE STRONG SHORTWAVE OVER NEBRASKA WILL SWING NORTHEAST AS IT PUSHES A SURFACE LOW FROM THE NORTHWEST CORNER OF ILLINOIS TO CENTRAL LAKE MICHIGAN TO THE STRAITS OF MACKINAC. AHEAD OF THE LOW...ELEVATED INSTABILITY UP TO 500 J/KG MAY SNEAK INTO EAST-CENTRAL WISCONSIN WITHIN A REGION OF STRONG UPWARD MOTION WHICH COULD GENERATE SCATTERED THUNDERSTORMS THOUGH AROUND MID-EVENING. IF THUNDERSTORMS DO OCCUR...SMALL HAIL WILL BE POSSIBLE. TO THE NORTH OF THE LOW...EXCELLENT UPPER DIVERGENCE COMBINED WITH STRONG MID-LEVEL FGEN AND REDUCED STABILITY WILL LEAD TO A HEALTHY DEFORMATION BAND DEVELOPING FROM WEST-CENTRAL TO NORTH-CENTRAL WISCONSIN. THIS DEFORMATION BAND WILL BRING A PROLONGED PERIOD OF MODERATE TO HEAVY PRECIP AT TIMES. WITH TEMPS AND DEWPOINTS IN THE MIDDLE 30S AT THE START OF THE EVENING...PRECIP WILL LIKELY BE ALL RAIN FOR THE FIRST COUPLE HOURS. THEN COLDER AIR WILL GRADUALLY GET DRAWN INTO NORTH-CENTRAL WISCONSIN TO CHANGE PRECIP TO SLEET AND THEN SNOW. BUFKIT SOUNDINGS INDICATE THAT THE NORTH COULD SEE A FEW HOUR PERIOD OF SLEET WHICH COULD LEAD TO DECENT SLEET ACCUMULATIONS GIVEN THE EXPECTED PRECIP RATES. THEN ONCE TEMPS COOL ENOUGH FOR ALL SNOW...SNOWFALL RATES COULD EASILY EXCEED AN INCH PER HOUR AT TIMES. BUT ONE OF THE MOST DIFFICULT ASPECTS OF THIS FORECAST IS IN REGARDS TO HOW QUICKLY THIS CHANGE OVER OCCURS SINCE COLD AIR IS NOT THAT PLENTIFUL TO OUR NORTH. BEST GUESS FROM GUIDANCE INDICATES THIS CHANGE OVER WILL OCCUR LATE THIS EVENING OVER N-C WISCONSIN AND EARLY OVERNIGHT OVER TO CENTRAL WISCONSIN TO THE IRON MOUNTAIN AREA. THE INITIAL RAIN AND SLEET WILL EAT UP SOME OF THE QPF AMOUNTS THIS EVENING...BUT GUIDANCE STILL POINT TOWARDS OVER A HALF INCH FALLING AFTER 06Z. ADDITIONALLY...THE HI-RES MODELS ARE ALSO INDICATING BANDING TAKING PLACE...AND A LITTLE FARTHER TO THE EAST THAN SHOWN PREVIOUSLY. HAVE SHIFTED QPF AND SNOW AMOUNTS TO THE EAST AS A RESULT...WHICH GIVES SNOW AMOUNTS OF 3-6 INCHES FROM LINCOLN AND LANGLADE ON NORTH. A QUARTER TO A HALF INCH OF THAT COULD TURN OUT TO BE SLEET ACCUMULATION. LOCALLY HIGHER AMOUNTS WILL BE POSSIBLE DEPENDING ON WHERE THE SNOW BANDS SET UP. BECAUSE OF THIS UNCERTAINTY...WILL ISSUE A WINTER WEATHER ADVISORY FROM 02Z-13Z. FRIDAY...PRECIP WITH SNOW WEST OF THE FOX VALLEY AND RAIN TO THE EAST WILL DIMINISH EARLY FRIDAY MORNING. SHOULD SEE A CLOUDY AND WINDY START TO THE DAY OTHERWISE. A TRAILING SHORTWAVE WILL PUSH ACROSS SOUTHERN WISCONSIN DURING THE AFTERNOON WHICH COULD CREATE AN ISOLATED SHOWER OVER THE NORTHERN HALF OF THE STATE. LEFT A SMALL CHANCE TO ACCOUNT FOR THIS. HIGHS RANGING FROM THE LOW 40S NORTH TO LOW 50S SOUTH. .LONG TERM...FRIDAY NIGHT THROUGH THURSDAY ISSUED AT 241 PM CDT THU APR 9 2015 PCPN TRENDS SUNDAY/SUNDAY NIGHT AND DURING THE MIDDLE OF NEXT WEEK ARE THE MAIN FCST CONCERNS. HIGH PRESSURE IS EXPECTED TO BUILD INTO THE REGION FRIDAY NIGHT. USED A BLEND OF THE BETTER PERFORMING GUIDANCE SETS FOR MIN TEMPS...BUT WITH THE POTENTIAL FOR A LINGERING SNOW COVER OVER NC WI...HAVE BUMPED MIN TEMPS DOWN THERE. HIGH PRESSURE WILL BRING DRY CONDITIONS SATURDAY AND SATURDAY NIGHT... WITH DEVELOPING SOUTH FLOW RESULTING IN MODERATING TEMPERATURES. A COLD FRONT WILL MOVE INTO WESTERN WI ON SUNDAY AFTERNOON...THEN ACROSS THE FORECAST AREA SUNDAY EVENING. HAVE SLOWED DOWN THE ARRIVAL TIME OF SHOWERS ON SUNDAY AFTERNOON (MAINLY NC/C WI LATE IN THE DAY)...BUT WILL SPREAD HIGH CHC/LOW LIKELY POPS OVER THE ENTIRE CWA SUNDAY NIGHT. H8 LI`S SLIGHTLY BLO ZERO AND STEEP MID- LEVEL LAPSE RATES SUGGEST POTENTIAL FOR AT LEAST ISOLD TSTMS...SO HAVE INCLUDED A SLGT CHC OF TSTMS. HIGH PRESSURE AND AND ASSOCIATED DRY AND MILD CONDITIONS WILL RETURN TO WISCONSIN ON MONDAY AND TUESDAY. THE FCST BECOMES A BIT MUDDLED DURING THE MIDDLE OF THE WEEK...AS SW FLOW ALOFT DEVELOPS AND LOW PRESSURE AND AN ASSOCIATED COLD FRONT EDGE TOWARD THE WESTERN GREAT LAKES. MOST MODELS NOW KEEP TUESDAY NIGHT DRY...WITH THE ECMWF BRINGING PCPN INTO THE REGION ON WEDS...AND THE GFS HOLDING OFF UNTIL ABOUT THURSDAY. GIVEN THE UNCERTAINTY...WILL CARRY CHC POPS THROUGH THIS PERIOD. THE GOOD NEWS IS THAT ANY PCPN THAT OCCURS SHOULD FALL AS ALL RAIN...WHICH IS DEFINITELY A STEP IN THE RIGHT DIRECTION. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1222 PM CDT THU APR 9 2015 IFR TO LIFR CIGS AND VSBYS TO PERSIST THROUGH THE EVENING AS A STRENGTHENING AREA OF LOW PRESSURE TRACKS NORTHEAST FROM THE CENTRAL PLAINS TO CENTRAL LAKE MICHIGAN. AHEAD OF THE LOW...AREAS OF SHOWERS AND FOG WILL PREVAIL THROUGH EARLY THIS EVENING...WITH A FEW THUNDERSTORMS MIXED IN OVER CENTRAL TO NORTHEAST WISCONSIN. THEN AS THE LOW PASSES...RAIN WILL CHANGE TO SNOW OVER CENTRAL AND NORTH-CENTRAL WISCONSIN WHERE SEVERAL INCHES ARE POSSIBLE...HIGHEST OVER NORTH-CENTRAL WISCONSIN INCLUDING RHI. THE SNOW WILL TAPER OFF LATE TONIGHT AT THE SAME TIME AS NORTHWEST WINDS BECOME STRONG AND GUSTY. CIGS WILL SLOWLY IMPROVE FRIDAY MORNING. && .GRB WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM CDT FRIDAY FOR WIZ011-012-019. WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 10 AM CDT FRIDAY FOR WIZ005-010-018. && $$ SHORT TERM.....MPC LONG TERM......KIECKBUSCH AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1243 PM CDT THU APR 9 2015 .UPDATE...THIS AFTERNOON ISSUED AT 1242 PM CDT THU APR 9 2015 KEEPING A CLOSE EYE ON GRANT...CLAYTON...CRAWFORD...AND RICHLAND COUNTIES THIS AFTERNOON FOR SEVERE THUNDERSTORM POTENTIAL. LATEST MESOSCALE FORECAST MODELS SUGGEST STORMS WILL INITIATE OVER EAST CENTRAL IOWA AND PUSH NORTH INTO THESE COUNTIES BY 3 TO 4 PM. CURRENTLY THE WARM FRONT IS IN PLACE ACROSS NORTHERN ILLINOIS INTO EAST CENTRAL IOWA AND IS MAKING NORTHWARD PROGRESS AS A VIGOROUS SHORTWAVE LIFTS NORTHEAST OUT OF NEBRASKA. WE SHOULD SEE A RAPIDLY DEEPENING SURFACE LOW LIFT ACROSS THE FORECAST AREA LATE THIS AFTERNOON. 0-6 KM BULK SHEAR VALUES OF 40 TO 50 KTS WOULD FAVOR SUPERCELLS AND WITH 0-1 KM BULK SHEAR VALUE APPROACHING 35 KTS THERE WILL BE MORE THAN ENOUGH SHEAR TO SUPPORT A TORNADO OR TWO. HOWEVER SURFACE BASED CAPE LOOKS TO STAY JUST SOUTHEAST OF THE FORECAST AREA WITH VALUES CLIMBING TO 2000-2500 J/KG ACROSS NORTHERN ILLINOIS AND EAST CENTRAL IOWA. THE BIG QUESTION IS WHETHER OR NOT WE CAN GET SURFACE BASED STORMS INTO GRANT COUNTY. BEING THAT THIS AREA IS NEAR THE TRIPLE POINT WE WILL HAVE TO KEEP A CLOSE EYE ON ANY STORMS IN THIS LOCATION WITH AN ENHANCED POTENTIAL FOR A ISOLATED TORNADO. THE MORE FAVORABLE PARAMETERS APPEAR TO BE ACROSS NORTHERN ILLINOIS AT THIS TIME. KEEP A CLOSE EYE ON THE FORECAST THIS AFTERNOON. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 335 AM CDT THU APR 9 2015 SEVERAL IMPULSES ARE EVIDENT IN THE SOUTHWESTERLY FLOW ALOFT PER LATEST WATER VAPOR SATELLITE IMAGERY THIS MORNING. FIRST IMPULSE PUSHING INTO CENTRAL WISCONSIN. THE LATEST 09.06Z RAP SHOWS CENTRAL AND EASTERN WISCONSIN ON NOSE OF DECENT 925-850MB MOISTURE TRANSPORT IN ASSOCIATION WITH SHORTWAVE TROUGH. LATEST MOSAIC RADAR INDICATING SHOWERS AND THUNDERSTORMS ACROSS MUCH OF WISCONSIN INTO SOUTHERN MICHIGAN. FIRST IMPULSE PUSHES NORTHEAST OF FORECAST AREA BY 10Z AND NEXT IMPULSE OVER EASTERN NEBRASKA WILL TRACK INTO THE FORECAST AREA BY 12Z. THE 09.00Z GFS/NAM/ECMWF ARE IN GOOD AGREEMENT FORECAST AREA WILL BE ON THE NOSE OF 925-850MB MOISTURE TRANSPORT AND CONVERGENCE BY 12Z THURSDAY. WITH CONVECTION ASSOCIATED WITH IMPULSE OCCURRING OVER EASTERN NEBRASKA. EXPECT THIS CONVECTION TO MOVE OVER THE FORECAST AREA AROUND 12Z THURSDAY. THIS IS EVIDENT BY THE LATEST HIRES MODELS 09.06Z HRRR AND 09.00Z ARW. NEXT CONCERN THEN WILL BE SEVERE CHANCES ACROSS THE EXTREME SOUTHERN AREAS OF THE FORECAST AREA THIS AFTERNOON. WITH ONGOING CONVECTION IN THE MORNING HOURS AND THE LATEST 09.00Z GFS/NAM/ECMWF AND 09.06Z TRACK SURFACE LOW OVER THE EXTREME SOUTHERN PORTION OF THE FORECAST AREA. THE SEVERE POSSIBILITIES ARE BECOMING LOWER ACROSS MUCH OF THE FORECAST AREA. THE 09.00Z NAM SUGGEST 0-6KM MOST UNSTABLE CAPE UP TO 1000 J/KG IN THE SOUTHERN MOST FORECAST AREA...WITH THE GFS SLIGHTLY HIGHER 0-6KM MOST UNSTABLE CAPE OF 1500 J/KG...DUE TO A SLIGHTLY FARTHER NORTHWEST SURFACE LOW TRACK THAN THE NAM. THE 09.00Z MODELS CONTINUE TO INDICATE STRONG SHEAR IN THE 0-3KM LAYER...APPROACHING 50 KNOTS. A FEW OF THE THUNDERSTORMS THIS AFTERNOON IN ASSOCIATION WITH MAIN UPPER LEVEL TROUGH/WAVE/SURFACE LOW COULD BE SEVERE ACROSS THE FAR SOUTHERN MOST FORECAST AREA...MOST LIKELY GRANT COUNTY IN SOUTHWEST WISCONSIN. MAIN THREATS WOULD BE LARGE HAIL AND DAMAGING WIND...BUT CANNOT RULE OUT AND ISOLATED TORNADO OVER THE EXTREME SOUTHERN MOST FORECAST AREA. FOCUS TURNS TO SURFACE LOW/UPPER LEVEL TROUGH/WAVE MOVING INTO THE SOUTHERN HALF OF WISCONSIN. THE LATEST 09.00Z GFS/NAM HAVE SHIFTED SURFACE LOW TRACK SLIGHTLY FARTHER WEST THAN PREVIOUS RUNS PER DPROG/DT. THIS WILL HAVE IMPACT ON TRACK OF FRONTOGENETIC BAND OF PRECIPITATION DEVELOPING ON THE NORTHWEST PERIPHERY OF THE SURFACE LOW. BOTH THE 09.00Z GFS/NAM SHOW STRONG LIFT WITH THE FRONTOGENETIC BAND PER CROSS SECTIONS AND BUFKIT SOUNDINGS OVER SOUTHEAST MINNESOTA AND WESTERN WISCONSIN. CONCERN WILL BE TEMPERATURES. THE 09.00Z MODELS WANT TO COOL ATMOSPHERE NEAR/AT/BELOW FREEZING AND CHANGE PRECIPITATION TO ALL SNOW OR MIX SNOW IN WITH THE RAIN OVER WESTERN WISCONSIN. FOR NOW...MAINLY HAVE RAIN/SNOW MIX WITH POTENTIAL ALL SNOW OVER PARTS OF NORTH CENTRAL WISCONSIN THIS EVENING INTO TONIGHT. SNOWFALL ACCUMULATION OF 1...POSSIBLY 2 INCHES COULD ACCUMULATE ACROSS NORTH CENTRAL WISCONSIN. HOWEVER...THERE IS POTENTIAL FOR HIGHER SNOWFALL AMOUNTS DEPENDING ON WHERE THE FRONTOGENETIC BAND OF PRECIPITATION TRACKS AND TEMPERATURE PROFILE OVER EASTERN MINNESOTA AND WESTERN WISCONSIN. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 335 AM CDT THU APR 9 2015 AS UPPER LEVEL TROUGH/LOW LIFTS NORTHEAST INTO SOUTHERN ONTARIO CANADA...SHORTWAVE TROUGH ON BACKSIDE OF UPPER LEVEL TROUGH/LOW MOVES OVER THE FORECAST AREA FRIDAY. THE 09.00Z GFS/NAM BUFKIT SOUNDINGS INDICATE DIURNALLY DRIVEN SCATTERED RAIN/SNOW SHOWERS...DEPENDING ON TEMPERATURES...TO DEVELOP MAINLY ALONG AND EAST OF THE MISSISSIPPI RIVER...WHERE BETTER SATURATION/LIFT EXIST. SATURDAY...HIGH PRESSURE BUILDS INTO THE UPPER MIDWEST AND GREAT LAKES REGION...PROVIDING WARMER TEMPERATURES AND MOSTLY SUNNY SKIES ACROSS THE AREA. NEXT FORECAST CONCERNS ARE PRECIPITATION CHANCES SATURDAY NIGHT INTO WEDNESDAY. THE 09.00Z GFS/ECMWF/GEM ARE IN AGREEMENT IN DEVELOPING WEST TO EAST ZONAL FLOW ACROSS THE CONTINENTAL UNITED STATES SUNDAY INTO MONDAY ACROSS THE NORTHERN TIER STATES AND AMPLIFY UPPER LEVEL RIDGE OVER THE CENTRAL UNITED STATES TUESDAY INTO WEDNESDAY. WITH THE UPPER LEVEL RIDGE AMPLIFYING OVER THE CENTRAL UNITED STATES... THE 09.00Z GFS/ECMWF ARE TRENDING TOWARDS A SLOWER SOLUTION ON LIFTING UPPER LEVEL TROUGH OVER THE SOUTHWEST UNITED NORTHWARD INTO THE UPPER GREAT LAKES/MIDWEST REGION MONDAY INTO WEDNESDAY. HAVE REMOVED PRECIPITATION CHANCES MONDAY INTO MONDAY NIGHT BASED ON THIS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1242 PM CDT THU APR 9 2015 PERIODS OF IFR AND LIFR CONDITIONS ALONG WITH SHOWERS AND THUNDERSTORMS ARE EXPECTED LATE THIS AFTERNOON INTO EARLY THIS EVENING AS A STRONG LOW PRESSURE SYSTEM LIFTS NORTHEAST ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. LOOK FOR WINDS TO INCREASE OUT OF THE NORTHEAST AS THE LOW APPROACHES LATE THIS AFTERNOON THEN TURN NORTHWEST AS THE LOW MOVES TO THE NORTHEAST OF THE REGION. LOOK FOR NORTHWEST WINDS TO INCREASE TO 18 TO 23 KTS TONIGHT WITH GUSTS OF AROUND 35 KTS POSSIBLE. MVFR CONDITIONS WILL RETURN LATE TONIGHT INTO EARLY FRIDAY MORNING. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ UPDATE...WETENKAMP SHORT TERM...DTJ LONG TERM...DTJ AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
703 AM CDT THU APR 9 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 335 AM CDT THU APR 9 2015 SEVERAL IMPULSES ARE EVIDENT IN THE SOUTHWESTERLY FLOW ALOFT PER LATEST WATER VAPOR SATELLITE IMAGERY THIS MORNING. FIRST IMPULSE PUSHING INTO CENTRAL WISCONSIN. THE LATEST 09.06Z RAP SHOWS CENTRAL AND EASTERN WISCONSIN ON NOSE OF DECENT 925-850MB MOISTURE TRANSPORT IN ASSOCIATION WITH SHORTWAVE TROUGH. LATEST MOSAIC RADAR INDICATING SHOWERS AND THUNDERSTORMS ACROSS MUCH OF WISCONSIN INTO SOUTHERN MICHIGAN. FIRST IMPULSE PUSHES NORTHEAST OF FORECAST AREA BY 10Z AND NEXT IMPULSE OVER EASTERN NEBRASKA WILL TRACK INTO THE FORECAST AREA BY 12Z. THE 09.00Z GFS/NAM/ECMWF ARE IN GOOD AGREEMENT FORECAST AREA WILL BE ON THE NOSE OF 925-850MB MOISTURE TRANSPORT AND CONVERGENCE BY 12Z THURSDAY. WITH CONVECTION ASSOCIATED WITH IMPULSE OCCURRING OVER EASTERN NEBRASKA. EXPECT THIS CONVECTION TO MOVE OVER THE FORECAST AREA AROUND 12Z THURSDAY. THIS IS EVIDENT BY THE LATEST HIRES MODELS 09.06Z HRRR AND 09.00Z ARW. NEXT CONCERN THEN WILL BE SEVERE CHANCES ACROSS THE EXTREME SOUTHERN AREAS OF THE FORECAST AREA THIS AFTERNOON. WITH ONGOING CONVECTION IN THE MORNING HOURS AND THE LATEST 09.00Z GFS/NAM/ECMWF AND 09.06Z TRACK SURFACE LOW OVER THE EXTREME SOUTHERN PORTION OF THE FORECAST AREA. THE SEVERE POSSIBILITIES ARE BECOMING LOWER ACROSS MUCH OF THE FORECAST AREA. THE 09.00Z NAM SUGGEST 0-6KM MOST UNSTABLE CAPE UP TO 1000 J/KG IN THE SOUTHERN MOST FORECAST AREA...WITH THE GFS SLIGHTLY HIGHER 0-6KM MOST UNSTABLE CAPE OF 1500 J/KG...DUE TO A SLIGHTLY FARTHER NORTHWEST SURFACE LOW TRACK THAN THE NAM. THE 09.00Z MODELS CONTINUE TO INDICATE STRONG SHEAR IN THE 0-3KM LAYER...APPROACHING 50 KNOTS. A FEW OF THE THUNDERSTORMS THIS AFTERNOON IN ASSOCIATION WITH MAIN UPPER LEVEL TROUGH/WAVE/SURFACE LOW COULD BE SEVERE ACROSS THE FAR SOUTHERN MOST FORECAST AREA...MOST LIKELY GRANT COUNTY IN SOUTHWEST WISCONSIN. MAIN THREATS WOULD BE LARGE HAIL AND DAMAGING WIND...BUT CANNOT RULE OUT AND ISOLATED TORNADO OVER THE EXTREME SOUTHERN MOST FORECAST AREA. FOCUS TURNS TO SURFACE LOW/UPPER LEVEL TROUGH/WAVE MOVING INTO THE SOUTHERN HALF OF WISCONSIN. THE LATEST 09.00Z GFS/NAM HAVE SHIFTED SURFACE LOW TRACK SLIGHTLY FARTHER WEST THAN PREVIOUS RUNS PER DPROG/DT. THIS WILL HAVE IMPACT ON TRACK OF FRONTOGENETIC BAND OF PRECIPITATION DEVELOPING ON THE NORTHWEST PERIPHERY OF THE SURFACE LOW. BOTH THE 09.00Z GFS/NAM SHOW STRONG LIFT WITH THE FRONTOGENETIC BAND PER CROSS SECTIONS AND BUFKIT SOUNDINGS OVER SOUTHEAST MINNESOTA AND WESTERN WISCONSIN. CONCERN WILL BE TEMPERATURES. THE 09.00Z MODELS WANT TO COOL ATMOSPHERE NEAR/AT/BELOW FREEZING AND CHANGE PRECIPITATION TO ALL SNOW OR MIX SNOW IN WITH THE RAIN OVER WESTERN WISCONSIN. FOR NOW...MAINLY HAVE RAIN/SNOW MIX WITH POTENTIAL ALL SNOW OVER PARTS OF NORTH CENTRAL WISCONSIN THIS EVENING INTO TONIGHT. SNOWFALL ACCUMULATION OF 1...POSSIBLY 2 INCHES COULD ACCUMULATE ACROSS NORTH CENTRAL WISCONSIN. HOWEVER...THERE IS POTENTIAL FOR HIGHER SNOWFALL AMOUNTS DEPENDING ON WHERE THE FRONTOGENETIC BAND OF PRECIPITATION TRACKS AND TEMPERATURE PROFILE OVER EASTERN MINNESOTA AND WESTERN WISCONSIN. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 335 AM CDT THU APR 9 2015 AS UPPER LEVEL TROUGH/LOW LIFTS NORTHEAST INTO SOUTHERN ONTARIO CANADA...SHORTWAVE TROUGH ON BACKSIDE OF UPPER LEVEL TROUGH/LOW MOVES OVER THE FORECAST AREA FRIDAY. THE 09.00Z GFS/NAM BUFKIT SOUNDINGS INDICATE DIURNALLY DRIVEN SCATTERED RAIN/SNOW SHOWERS...DEPENDING ON TEMPERATURES...TO DEVELOP MAINLY ALONG AND EAST OF THE MISSISSIPPI RIVER...WHERE BETTER SATURATION/LIFT EXIST. SATURDAY...HIGH PRESSURE BUILDS INTO THE UPPER MIDWEST AND GREAT LAKES REGION...PROVIDING WARMER TEMPERATURES AND MOSTLY SUNNY SKIES ACROSS THE AREA. NEXT FORECAST CONCERNS ARE PRECIPITATION CHANCES SATURDAY NIGHT INTO WEDNESDAY. THE 09.00Z GFS/ECMWF/GEM ARE IN AGREEMENT IN DEVELOPING WEST TO EAST ZONAL FLOW ACROSS THE CONTINENTAL UNITED STATES SUNDAY INTO MONDAY ACROSS THE NORTHERN TIER STATES AND AMPLIFY UPPER LEVEL RIDGE OVER THE CENTRAL UNITED STATES TUESDAY INTO WEDNESDAY. WITH THE UPPER LEVEL RIDGE AMPLIFYING OVER THE CENTRAL UNITED STATES... THE 09.00Z GFS/ECMWF ARE TRENDING TOWARDS A SLOWER SOLUTION ON LIFTING UPPER LEVEL TROUGH OVER THE SOUTHWEST UNITED NORTHWARD INTO THE UPPER GREAT LAKES/MIDWEST REGION MONDAY INTO WEDNESDAY. HAVE REMOVED PRECIPITATION CHANCES MONDAY INTO MONDAY NIGHT BASED ON THIS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 703 AM CDT THU APR 9 2015 SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS WILL MOVE THROUGH THE AREA TODAY. THE BEST CHANCES FOR THUNDERSTORMS AT THE TAF SITES LOOKS TO BE FROM 09.13Z AND 09.15Z. ADDITIONAL THUNDERSTORMS MAY BE POSSIBLE THIS AFTERNOON...BUT TIMING IS UNCERTAIN...SO IT WAS NOT INCLUDED IN THE TAFS. CEILINGS THROUGHOUT THE TIME PERIOD WILL BE MAINLY LIFR/IFR AT KRST AND IFR/MVFR AT KRST. VISIBILITIES THROUGH 10.06Z WILL BE ANYWHERE FROM 1 TO 3 MILES AT KRST AND MVFR/VFR AT KLSE. THROUGH TODAY THE NORTHEAST WINDS WILL REMAIN AT 10 KNOTS OR LESS AND THEN SWITCH TO THE WEST THIS EVENING AND CLIMB TO AROUND 20 KNOTS WITH WINDS GUSTING INTO THE 30 TO 35 KNOT RANGE. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DTJ LONG TERM...DTJ AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
336 AM CDT THU APR 9 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 335 AM CDT THU APR 9 2015 SEVERAL IMPULSES ARE EVIDENT IN THE SOUTHWESTERLY FLOW ALOFT PER LATEST WATER VAPOR SATELLITE IMAGERY THIS MORNING. FIRST IMPULSE PUSHING INTO CENTRAL WISCONSIN. THE LATEST 09.06Z RAP SHOWS CENTRAL AND EASTERN WISCONSIN ON NOSE OF DECENT 925-850MB MOISTURE TRANSPORT IN ASSOCIATION WITH SHORTWAVE TROUGH. LATEST MOSAIC RADAR INDICATING SHOWERS AND THUNDERSTORMS ACROSS MUCH OF WISCONSIN INTO SOUTHERN MICHIGAN. FIRST IMPULSE PUSHES NORTHEAST OF FORECAST AREA BY 10Z AND NEXT IMPULSE OVER EASTERN NEBRASKA WILL TRACK INTO THE FORECAST AREA BY 12Z. THE 09.00Z GFS/NAM/ECMWF ARE IN GOOD AGREEMENT FORECAST AREA WILL BE ON THE NOSE OF 925-850MB MOISTURE TRANSPORT AND CONVERGENCE BY 12Z THURSDAY. WITH CONVECTION ASSOCIATED WITH IMPULSE OCCURRING OVER EASTERN NEBRASKA. EXPECT THIS CONVECTION TO MOVE OVER THE FORECAST AREA AROUND 12Z THURSDAY. THIS IS EVIDENT BY THE LATEST HIRES MODELS 09.06Z HRRR AND 09.00Z ARW. NEXT CONCERN THEN WILL BE SEVERE CHANCES ACROSS THE EXTREME SOUTHERN AREAS OF THE FORECAST AREA THIS AFTERNOON. WITH ONGOING CONVECTION IN THE MORNING HOURS AND THE LATEST 09.00Z GFS/NAM/ECMWF AND 09.06Z TRACK SURFACE LOW OVER THE EXTREME SOUTHERN PORTION OF THE FORECAST AREA. THE SEVERE POSSIBILITIES ARE BECOMING LOWER ACROSS MUCH OF THE FORECAST AREA. THE 09.00Z NAM SUGGEST 0-6KM MOST UNSTABLE CAPE UP TO 1000 J/KG IN THE SOUTHERN MOST FORECAST AREA...WITH THE GFS SLIGHTLY HIGHER 0-6KM MOST UNSTABLE CAPE OF 1500 J/KG...DUE TO A SLIGHTLY FARTHER NORTHWEST SURFACE LOW TRACK THAN THE NAM. THE 09.00Z MODELS CONTINUE TO INDICATE STRONG SHEAR IN THE 0-3KM LAYER...APPROACHING 50 KNOTS. A FEW OF THE THUNDERSTORMS THIS AFTERNOON IN ASSOCIATION WITH MAIN UPPER LEVEL TROUGH/WAVE/SURFACE LOW COULD BE SEVERE ACROSS THE FAR SOUTHERN MOST FORECAST AREA...MOST LIKELY GRANT COUNTY IN SOUTHWEST WISCONSIN. MAIN THREATS WOULD BE LARGE HAIL AND DAMAGING WIND...BUT CANNOT RULE OUT AND ISOLATED TORNADO OVER THE EXTREME SOUTHERN MOST FORECAST AREA. FOCUS TURNS TO SURFACE LOW/UPPER LEVEL TROUGH/WAVE MOVING INTO THE SOUTHERN HALF OF WISCONSIN. THE LATEST 09.00Z GFS/NAM HAVE SHIFTED SURFACE LOW TRACK SLIGHTLY FARTHER WEST THAN PREVIOUS RUNS PER DPROG/DT. THIS WILL HAVE IMPACT ON TRACK OF FRONTOGENETIC BAND OF PRECIPITATION DEVELOPING ON THE NORTHWEST PERIPHERY OF THE SURFACE LOW. BOTH THE 09.00Z GFS/NAM SHOW STRONG LIFT WITH THE FRONTOGENETIC BAND PER CROSS SECTIONS AND BUFKIT SOUNDINGS OVER SOUTHEAST MINNESOTA AND WESTERN WISCONSIN. CONCERN WILL BE TEMPERATURES. THE 09.00Z MODELS WANT TO COOL ATMOSPHERE NEAR/AT/BELOW FREEZING AND CHANGE PRECIPITATION TO ALL SNOW OR MIX SNOW IN WITH THE RAIN OVER WESTERN WISCONSIN. FOR NOW...MAINLY HAVE RAIN/SNOW MIX WITH POTENTIAL ALL SNOW OVER PARTS OF NORTH CENTRAL WISCONSIN THIS EVENING INTO TONIGHT. SNOWFALL ACCUMULATION OF 1...POSSIBLY 2 INCHES COULD ACCUMULATE ACROSS NORTH CENTRAL WISCONSIN. HOWEVER...THERE IS POTENTIAL FOR HIGHER SNOWFALL AMOUNTS DEPENDING ON WHERE THE FRONTOGENETIC BAND OF PRECIPITATION TRACKS AND TEMPERATURE PROFILE OVER EASTERN MINNESOTA AND WESTERN WISCONSIN. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 335 AM CDT THU APR 9 2015 AS UPPER LEVEL TROUGH/LOW LIFTS NORTHEAST INTO SOUTHERN ONTARIO CANADA...SHORTWAVE TROUGH ON BACKSIDE OF UPPER LEVEL TROUGH/LOW MOVES OVER THE FORECAST AREA FRIDAY. THE 09.00Z GFS/NAM BUFKIT SOUNDINGS INDICATE DIURNALLY DRIVEN SCATTERED RAIN/SNOW SHOWERS...DEPENDING ON TEMPERATURES...TO DEVELOP MAINLY ALONG AND EAST OF THE MISSISSIPPI RIVER...WHERE BETTER SATURATION/LIFT EXIST. SATURDAY...HIGH PRESSURE BUILDS INTO THE UPPER MIDWEST AND GREAT LAKES REGION...PROVIDING WARMER TEMPERATURES AND MOSTLY SUNNY SKIES ACROSS THE AREA. NEXT FORECAST CONCERNS ARE PRECIPITATION CHANCES SATURDAY NIGHT INTO WEDNESDAY. THE 09.00Z GFS/ECMWF/GEM ARE IN AGREEMENT IN DEVELOPING WEST TO EAST ZONAL FLOW ACROSS THE CONTINENTAL UNITED STATES SUNDAY INTO MONDAY ACROSS THE NORTHERN TIER STATES AND AMPLIFY UPPER LEVEL RIDGE OVER THE CENTRAL UNITED STATES TUESDAY INTO WEDNESDAY. WITH THE UPPER LEVEL RIDGE AMPLIFYING OVER THE CENTRAL UNITED STATES... THE 09.00Z GFS/ECMWF ARE TRENDING TOWARDS A SLOWER SOLUTION ON LIFTING UPPER LEVEL TROUGH OVER THE SOUTHWEST UNITED NORTHWARD INTO THE UPPER GREAT LAKES/MIDWEST REGION MONDAY INTO WEDNESDAY. HAVE REMOVED PRECIPITATION CHANCES MONDAY INTO MONDAY NIGHT BASED ON THIS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1100 PM CDT WED APR 8 2015 CIGS... NOT A LOT OF CHANGE EXPECTED THROUGH THU NIGHT WITH MOST CIGS HOVERING AROUND OR BELOW 1 KFT. VARIOUS BOUTS OF SHRA/TS WILL KEEP CIGS LOWS...AS WILL POOLED MOISTURE UNDER A STRONG LOW LEVEL INVERSION. WINDS... WINDS WILL GO FROM EAST TO NORTH NORTH/NORTHWEST THU AFTERNOON AS AN AREA OF LOW PRESSURE SLIDES JUST SOUTH OF THE TAF SITES. INCREASING PRESSURE GRADIENT ON THE NORTHWEST SIDE OF THE LOW SHOULD RESULT IN AN INCREASE IN SUSTAINED WINDS - ALONG WITH THE POTENTIAL FOR HIGHER GUSTS - THU NIGHT. WX/VSBY... BANDS OF SHOWERS WILL SWEEP ACROSS THE REGION TONIGHT INTO THU NIGHT. THERE WILL LIKELY BE SEVERAL HOUR BREAKS BETWEEN THEM...BUT TRYING TO FERRET OUT EXACT TIMING IS PROBLEMATIC...SO WON/T GET THAT REFINED IN THE FORECAST. FOR THUNDER CHANCES...BUFKIT SOUNDINGS SHOW MEAGER INSTABILITY A LOFT...AND INTERESTINGLY MOST OF IT IS ABOVE THE SATURATED LAYER. THAT SAID...A FEW STORMS HAVE DEVELOPED AND APPROACHED KRST/KLSE. HAD TO UPDATE PREVIOUS TAFS TO INCLUDE MENTION FOR A FEW HOURS PAST 06Z. RUC GRADUALLY SINKS THE ELEVATED INSTABILITY SOUTHWARD OVERNIGHT. COULD BE ISOLATED THUNDER THU INTO THU NIGHT...BUT CONFIDENCE TOO LOW TO INCLUDE IN FORECAST AT THIS TIME. ALSO OF NOTE IN THE BUFKIT SOUNDINGS IS THE SOMEWHAT SHALLOW NATURE OF A LOT OF THE SATURATION. IN MANY WAYS ITS MORE SUGGESTIVE OF A HEAVY DRIZZLE RATHER THAN SHRA/RA TYPE EVENT. HAVE NOTED DRIZZLE ALREADY THIS EVENING...BEFORE SHOWERS MOVED IN. THU AFTERNOON SEEMS TO FAVOR DRIZZLE TOO. VSBYS WILL BE RESTRICTED IN THE HEAVIER PCPN...ESPECIALLY IF HEAVY DRIZZLE MANIFESTS. SOME FOG SHOULD HELP LOWER VSBYS OVERNIGHT INTO THU MORNING. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DTJ LONG TERM...DTJ AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1229 AM EDT SAT APR 11 2015 .SYNOPSIS... ISSUED AT 1229 AM EDT SAT APR 11 2015 THE WEEKEND WILL FEATURE DRY CONDITIONS AND AMPLE SUNSHINE AS HIGH PRESSURE TRACKS EAST THROUGH THE OHIO VALLEY AND MID ATLANTIC. HIGHS ON SATURDAY WILL REACH TO NEAR 60S DEGREES...AND INTO THE MID 60S ON SUNDAY. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 357 PM EDT FRI APR 10 2015 987MB SURFACE LOW LIFTING INTO QUEBEC AT PRESS TIME WITH A SECONDARY VORT MAX AND SURFACE PRESSURE TROUGH CURRENTLY ROTATING THROUGH CHICAGO. BRIEF RELAXATION OF PRESSURE GRADIENT AHEAD OF THIS BOUNDARY HAS ALLOWED WIND SPEEDS TO SUBSIDE A BIT THIS AFTERNOON. HOWEVER...UPSTREAM SURFACE OBS SHOW NUMEROUS GUSTS OVER 40 KTS ALONG AND IMMEDIATELY BEHIND THE FRONT. RAP FORECAST SOUNDINGS INDICATE VERY DEEP MIXING HEIGHTS IN PLACE OVER OUR AREA LATE THIS AFTERNOON WITH 50 KT WINDS AT THE TOP OF THE BOUNDARY LAYER AND A GOOD PUSH OF ISENTROPIC DESCENT SEEN MOVING IN BEHIND THE SURFACE BOUNDARY. MSAS ANALYSIS ALSO SHOWS A DECENT PRESSURE RISE-FALL COUPLET ALONG THIS BOUNDARY THAT MAY BE HELPING PRODUCE THE HIGHER WIND GUSTS. WE DO START TO LOSE DIURNAL SURFACE HEATING/BETTER PBL MIXING BY THE TIME THIS TROUGH MAKES IT TO OUR AREA BUT AM CONCERNED WE COULD SEE A FEW GUSTS TO WIND ADVISORY CRITERIA...ESPECIALLY IN OUR SOUTHWEST ZONES...DURING THE EARLY EVENING AND AM HESITANT TO SOUND THE "ALL CLEAR" ON STRONG WIND GUSTS. HAVE THEREFORE DECIDED TO EXTEND AND EXPAND THE WIND ADVISORY CURRENTLY IN PLACE. THIS SECONDARY PV ANOMALY...EXTENDING DEEP INTO THE TROPOSPHERE...MAY ALSO GENERATE SOME SHOWERS AS IT ROTATES THROUGH THE REGION THIS EVENING. UPSTREAM RADAR/SURFACE OBS SHOW DECENT SHOWERS...AND EVEN A FEW THUNDERSTORMS...OCCURRING WITH THIS WAVE AND SUSPECT SIMILAR RESULTS IN OUR LOCAL AREA. MOST OF THE LATEST HI-RES/RAPID UPDATE MODELS GENERATE AT LEAST SOME QPF IN OUR NORTHERN CWA AND SEE NO REASON TO ARGUE BASED ON STRENGTH/DEPTH OF THE ANOMALY SEEN IN BOTH WV IMAGERY AND MODEL PLAN VIEWS. HAVE THEREFORE RAISED POPS FOR OUR NORTHERN ZONES IN THE 22-03Z TIMEFRAME. IT IS POSSIBLE THAT THESE SHOWERS COULD HELP MIX DOWN SOME STRONGER WIND GUSTS IN THE 40-50 MPH RANGE THIS EVENING....PROVIDING FURTHER SUPPORT FOR A SIMPLE EXTENSION OF THE CURRENT WIND ADVISORY. OVERNIGHT LOWS SHOULD EASILY DROP INTO THE MID 30S UNDER STRONG CAA. STAYED PRETTY CLOSE TO INHERITED FORECAST...WHICH WAS SIMILAR TO LATEST MOS GUIDANCE. WELCOME RETURN TO MORE TRANQUIL WEATHER BY TOMORROW AS MID/UPPER LEVEL RIDGING AND SURFACE ANTICYCLONE BUILD DIRECTLY OVERHEAD. SOME LATE DAY WAA AND FULL SUN SHOULD PUSH US TO AROUND 60F DESPITE COOL START. && .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 357 PM EDT FRI APR 10 2015 LONG TERM FORECAST STARTS OUT QUIET...WITH AN AMPLIFYING 500MB RIDGE ALOFT AND SFC HIGH PRESSURE CENTERED OVER THE OHIO VALLEY SATURDAY NIGHT. SKIES WILL START OUT CLEAR IN THE EVENING...THEN BECOME PARTLY CLOUDY WEST AND CENTRAL AS A LOW PRESSURE TROUGH APPROACHES FROM THE WEST. LOWS WILL BE ON THE COOL SIDE BUT NEAR NORMAL FOR THIS TIME OF YEAR...ESPECIALLY IN THE NORTHEAST GIVEN CLEAR SKIES AND LIGHT WINDS. KEPT GOING FORECAST OF TEMPS IN THE MID-UPPER 30S. CHANCES FOR PRECIPITATION AND FORECAST COMPLEXITY RETURN LATE WEEKEND AND CONTINUE THROUGH THE WORK WEEK...WITH A COMPLICATED PATTERN AND THE ASSOCIATED MODEL DISAGREEMENT. SUNDAY AFTERNOON-EVENING THE CWA SITS ON THE OUTER EDGE OF THE SFC HIGH PRESSURE SYSTEM...WHICH BY THIS TIME IS JUST OFF THE EASTERN US COAST. AT THE UPPER LEVELS...THE RIDGE OVER THE GREAT LAKES REGION BEGINS TO BREAK DOWN AS VARIOUS SHORTWAVES PROPAGATE THROUGH THE FLOW FROM THE DEEPENING TROUGH MOVING THROUGH THE NORTHERN PLAINS. A SURFACE LOW PRESSURE SYSTEM IS LOCATED OVER MANITOBA. BY LATE SUNDAY AFTERNOON/EVENING THE SURFACE LOW PRESSURE TROUGH/COLD FRONT EXTENDS FROM MN/WI SOUTHWESTWARD TO THE CENTRAL PLAINS. GENERAL DISAGREEMENT AMONG MODELS ON EXACT TIMING OF ANY PRECIPITATION...WITH THE GFS BEING MOST PROGRESSIVE AND DEVELOPING PRECIPITATION AHEAD OF THE COLD FRONT SUNDAY AFTERNOON IN OUR CWA...AND THE NAM/GEM ECMWF WAITING UNTIL SUNDAY NIGHT/MONDAY MORNING TO BRING IN PRECIPITATION. THE ECMWF CAMP IS ALSO A BIT SHARPER WITH THE UL TROUGH...WHEREAS THE GFS IS MORE BROAD. DECIDED TO GO WITH A GFS/ECMWF COMPROMISE FOR NOW WITH RESPECT TO TIMING OF POPS. THIS BRINGS THE FRONT THROUGH SUNDAY EVENING AND HAS IT EXITING THE EASTERN CWA BY MONDAY AFTERNOON...AND HAVE POPS/WINDS REFLECTING THIS. MOISTURE WILL BE AMPLE AHEAD OF THE FRONT...AS PWATS INCREASE TO AROUND 1.3 INCHES WITH RETURN FLOW AROUND THE SFC HIGH AND APPROACHING LOW PRESSURE TROUGH TO WEST...PULLING MOISTURE RIGHT FROM THE GULF OF MEXICO. FRONT MOVEMENT SHOULD BE PRETTY QUICK...AND INSTABILITY IS MINIMAL SO DONT REALLY HAVE ANY CONCERNS FOR STORMS WITH THIS. DID ADD A SLGHT CHANCE FOR THUNDER LATE SUN NIGHT WITH SOME MODELS GENERATING 100-200 J/KG OF MUCAPE...BUT NOT REALLY CONFIDENT IN THAT OCCURRING. SURFACE HIGH PRESSURE QUICKLY MOVES IN UNDERNEATH A BUILDING UPPER LEVEL RIDGE MONDAY NIGHT INTO TUESDAY AND TUESDAY NIGHT...WHICH MODELS APPEAR TO AGREE ON. AS A RESULT...KEPT THINGS DRY FOR THAT TIME. HOWEVER...BY MID TO LATE WEEK...PROBLEMS DEVELOP AS THEY ATTEMPT TO RESOLVE SPLIT FLOW ALOFT...WITH A TROUGH LIFTING FROM THE SOUTHWESTERN U.S. INTO THE CENTRAL PLAINS 00Z WED...AND ANOTHER TROUGH/POTENTIAL CLOSED LOW MOVING EASTWARD INTO THE CANADIAN PRAIRIE THROUGH THURSDAY. BOTH THE GFS/ECMWF DEVELOP A SURFACE/UPPER LEVEL TROUGH THAT EXTENDS FROM THE DAKOTAS SOUTHEASTWARD ACROSS OUR CWA...AND INTO KY/TN. THIS BRINGS US SLIGHT CHANCES FOR PRECIPITATION WEDNESDAY...AND HIGHER POPS INTO THURSDAY/FRIDAY AS THE PATTERN SOLIDIFIES INTO A CUT-OFF LOW OVER THE MIDWEST. THE LOW EVENTUALLY DRIFTS ACROSS THE GREAT LAKES REGION...BUT AS TO STRENGTH/TIMING/EXACTLY HOW FAR SOUTH THE LOW MOVES....ITS ALL UP IN THE AIR. KEPT CONSENSUS CHANCE POPS IN FOR THIS TIME PERIOD...WITH CHANCE THUNDER ONLY ON THURSDAY WHEN BOTH MODELS HAVE US IN THE WARM SECTOR OF THE OCCLUDED SFC LOW. CONFIDENCE IN THIS FORECAST IS LOWER...GIVEN MODEL DISCREPANCIES AND DIFFICULTIES HANDLING THE MERGING FEATURES. AS FAR AS TEMPERATURES GO...LOOKS TO STAY NEAR NORMAL FOR THE MOST PART...WITH HIGHS IN THE 60S/UPPER 50S NEAR THE LAKE/ AND LOWS IN THE UPPER 30S AND 40S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1229 AM EDT SAT APR 11 2015 VFR/DRY WITH MUCH LIGHTER WINDS AS HIGH PRESSURE DRIFTS TOWARD THE OH VALLEY. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...STEINWEDEL SHORT TERM...AGD LONG TERM...MCD AVIATION...STEINWEDEL VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS WICHITA KS
330 AM CDT SAT APR 11 2015 .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 330 AM CDT SAT APR 11 2015 MID-LEVEL WARM ADVECTION AND A WEAK TRANSIENT SHORTWAVE ALOFT HAS OVERCOME SEEMINGLY MODEST MOISTURE AND RESULTED IN SCATTERED ELEVATED SHOWERS/ISOLATED STORMS FROM NORTH CENTRAL OKLAHOMA ACROSS SOUTHERN KANSAS EARLY THIS MORNING. THE LATEST RUC HAS THE BEST HANDLE ON THIS ACTIVITY WHICH LINGERS IT INTO THE 12Z- 15Z TIME FRAME ACROSS SOUTHEAST KANSAS. STRONGER ELEVATED LOW LEVEL MOISTURE TRANSPORT WILL DEVELOP ACROSS THE AREA TONIGHT AS ANOTHER SHORTWAVE ALOFT MIGRATES EAST ACROSS THE CENTRAL PLAINS. THIS WILL ALLOW DIURNAL CONVECTION ACROSS THE HIGH PLAINS LATER TODAY TO DEVELOP/MOVE EAST ACROSS MUCH OF THE AREA OVERNIGHT. SOME OF THIS ACTIVITY WILL LINGER INTO SUNDAY MORNING ACROSS SOUTHEAST KANSAS...BEFORE RENEWED SURFACE BASED CONVECTION DEVELOPS ALONG A SURFACE COLD FRONT WHICH WILL MOVE INTO CENTRAL KANSAS DURING THE AFTERNOON AS THE ASSOCIATED UPPER TROF MOVES ACROSS THE NORTHERN PLAINS. MODERATE INSTABILITY AND DEEP LAYER SHEAR SHOULD SUPPORT STRONG TO MARGINALLY SEVERE STORMS. WHILE INTENSITY SHOULD DECREASE BY SUNDAY EVENING...COVERAGE WILL LIKELY INCREASE ALONG THE FRONT AS IT MOVES INTO SOUTHEAST KANSAS. COOLER AND DRIER WEATHER IS STILL ON TAP FOR MONDAY. DARMOFAL .LONG TERM...(TUESDAY THROUGH FRIDAY) ISSUED AT 330 AM CDT SAT APR 11 2015 CHANCES FOR PRECIP LOOK TO INCREASE BY MID TO LATE NEXT WEEK WITH THE MEDIUM RANGE MODELS SHOWING AN UPPER TROF MOVING FROM THE ROCKIES AND BECOMING A CLOSED LOW ACROSS THE CENTRAL PLAINS. THERE IS STILL UNCERTAINTY IN THE EVOLUTION AND MOVEMENT/TRACK OF THIS SYSTEM...THOUGH FORECAST CONSENSUS SUPPORTS MODEST CHANCE POPS BY WEDNESDAY NIGHT AND THURSDAY. KED && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1147 PM CDT FRI APR 10 2015 WINDS REMAIN LIGHTER AND MORE SOUTHEASTERLY THAN EARLIER THOUGHT. STILL THINK SOUTHERLY WINDS WILL INCREASE OVERNIGHT AND BE BREEZY DURING THE DAY SATURDAY. MID-HIGH CLOUDS HAVE INCREASED AND WILL BE PREVALENT THROUGH THE DAY. A FEW SCATTERED LIGHT SHOWERS MAY IMPACT SOUTHERN AREAS...BUT HAVE ONLY INCLUDED AT KICT AS CONFIDENCE IT WILL IMPACT OTHER TERMINALS AT THIS TIME IS LOW. SMOKE FROM EARLIER FIRES OVER THE FLINT HILLS STILL IMPACTS AT KCNU WITH A CEILING BUT IT IS NOW OVER VFR. RAIN CHANCES INCREASE TOWARD THE END OF THE TAF PERIOD...WILL ALLOW LATER SHIFTS TO PINPOINT TIMING AS THE FORECAST EVOLVES. BILLINGS WRIGHT && .FIRE WEATHER... ISSUED AT 330 AM CDT SAT APR 11 2015 PERIODIC CHANCES FOR SHOWERS AND STORMS WILL EXIST ACROSS THE AREA THIS WEEKEND...WITH THE BEST CHANCES TONIGHT ACROSS CENTRAL KANSAS AND SUNDAY NIGHT ACROSS SOUTHEAST AND SOUTH CENTRAL KANSAS. OTHERWISE...INCREASING SOUTH WINDS WILL ELEVATE THE GRASSLAND FIRE DANGER THIS AFTERNOON IN RAIN-FREE AREAS AS WELL AS SUNDAY AFTERNOON. KED && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 71 56 77 53 / 20 40 40 60 HUTCHINSON 71 55 78 49 / 20 50 40 40 NEWTON 70 55 76 50 / 20 50 40 50 ELDORADO 71 56 76 53 / 30 50 40 60 WINFIELD-KWLD 71 56 76 55 / 20 30 40 70 RUSSELL 72 55 78 44 / 30 50 20 20 GREAT BEND 70 55 79 46 / 30 50 20 20 SALINA 72 55 78 46 / 20 60 40 30 MCPHERSON 71 55 77 48 / 20 60 40 40 COFFEYVILLE 72 54 77 57 / 30 30 40 70 CHANUTE 71 54 76 54 / 30 50 50 70 IOLA 71 53 75 54 / 20 60 50 70 PARSONS-KPPF 71 54 76 56 / 30 30 40 70 && .ICT WATCHES/WARNINGS/ADVISORIES...NONE. && $$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1243 AM CDT SAT APR 11 2015 .UPDATE... ISSUED AT 958 PM CDT FRI APR 10 2015 JUST PUBLISHED A RATHER "COSMETIC" UPDATE FOR THE REMAINDER OF THE OVERNIGHT HOURS (THROUGH 12Z/7AM)...WITH VERY LITTLE NOTICEABLE CHANGE FROM THE PREVIOUS FORECAST. FOR THE MOST PART...THE OVERNIGHT HOURS SHOULD FEATURE NO WORSE THAN MOSTLY CLEAR-PARTLY CLOUDY SKIES UNDER PRIMARILY PASSING THIN HIGH CLOUDS. BREEZES WILL AVERAGE 5-10 MPH FROM THE SOUTH...AS OVERNIGHT LOWS ARE EXPECTED TO DROP NO LOWER THAN THE 39-44 RANGE FOR THE MAJORITY OF THE CWA. REALLY THE ONLY POSSIBLE "CAVEAT" THROUGH SUNRISE INVOLVES WHETHER OR NOT SOME SPRINKLES OR LIGHT RAIN SHOWERS COULD POSSIBLY BRUSH INTO THE FAR SOUTHWEST EDGES OF THE CWA (NAMELY THE ROOKS COUNTY KS AREA) SOMETIME AFTER 4 AM OR SO. WHILE THIS IS NOT OUT OF THE QUESTION...DID NOT FEEL THERE WAS ENOUGH EVIDENCE IN THE LATEST MODEL DATA (INCLUDING RAP 13/HRRR) TO "RUIN" THE CURRENTLY-DRY OVERNIGHT FORECAST...AS CERTAINLY THE BETTER CHANCES FOR SPOTTY RAIN LATE SHOULD FOCUS AT LEAST SLIGHTLY WEST AND/OR SOUTHWEST OF THE CWA. MADE NO CHANGES TO THE POST-SUNRISE FORECAST AT THIS TIME...BUT IT STILL APPEARS THE MAJORITY OF THE CWA SHOULD GET THROUGH THE DAYLIGHT HOURS DRY...WITH ANY LIMITED SHOWER/THUNDERSTORM POTENTIAL PRIMARILY FOCUSED WITHIN SOUTHERN AND/OR WESTERN PORTIONS OF THE LOCAL AREA. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 333 PM CDT FRI APR 10 2015 SATELLITE AND OBSERVATIONS SHOW MOSTLY SUNNY SKIES ACROSS THE AREA WITH A FEW CIRRUS IN THE SOUTHERN PART OF THE FORECAST AREA. SURFACE ANALYSIS SHOWS A WEAK HIGH PRESSURE SYSTEM ACROSS THE AREA. THE SURFACE HIGH ACROSS THE AREA WILL CONTINUE TO MOVE TO THE EAST THIS AFTERNOON AND EVENING. WINDS ARE EXPECTED TO TURN TO THE SOUTH DURING THE NIGHT. AN UPPER LEVEL WAVE APPROACHES THE AREA LATE TONIGHT. EXPECT MOSTLY CLEAR SKIES TO CONTINUE THROUGH THE NIGHT. ON SATURDAY...THE UPPER LEVEL WAVE WILL CONTINUE TO MOVE THROUGH THE AREA. WITH THE SOUTH WINDS THROUGH THE NIGHT...THE LOW LEVEL MOISTURE WILL INCREASE. WITH THE INCREASE IN MOISTURE THERE WILL BE AN INCREASE IN INSTABILITY. MUCAPE INCREASES TO NEARLY 1500 J/KG IN THE SOUTHWEST PART OF THE AREA. HAVE BACKED OFF A LITTLE BRINGING THE PRECIPITATION INTO THE AREA ON SATURDAY. HAVE KEPT A LITTLE IN THE FAR SOUTH IN THE MORNING...BUT EXPECT THAT MOST OF THE PRECIPITATION WILL BE DURING THE AFTERNOON. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 333 PM CDT FRI APR 10 2015 UNSETTLED WEATHER THROUGH THE PERIOD WITH PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS. NO WIDESPREAD RAINS ON THE HORIZON...BUT SCATTERED SHOWERS AND STORMS POSSIBLE SUNDAY AND AGAIN WEDNESDAY AND THURSDAY. POTENTIAL FIRE WEATHER CONCERNS TUESDAY AFTERNOON OVER THE WEST DUE TO LOW HUMIDITIES AND STRONG WINDS. TEMPERATURES WILL BE SEASONABLE...EVEN ABOUT 10 DEGREES ABOVE NORMAL FOR MOST DAYS IN THE PERIOD. THE NORMAL IS 60 TO 65 FOR HIGH TEMPS AND AROUND FREEZING FOR LOW TEMPS. PATTERN-WISE...A ZONAL FLOW RETURNS WITH PERIODIC WAVES MOVING THROUGH. THE NORMAL RESULTING WEATHER WITH THIS TYPE PATTERN IS ABOVE NORMAL TEMPS AND GENERALLY DRY WEATHER...ALTHOUGH PERIODIC WAVES BRING FRONTS THROUGH THAT ACT AS A FOCUS FOR SHOWERS AND THUS A FEW PLACES MAY GET SOME RAIN ON AND OFF. MODELS...THE EUROPEAN AND GFS ARE IN PHASE THE FIRST FEW DAYS...BUT AFTER WEDNESDAY THE GFS DEVELOPS SYSTEMS FASTER. PREFER THE TIMING OF THE SLOWER EUROPEAN BASED ON EXPERIENCE AND PATTERN RECOGNITION. && .AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1240 AM CDT SAT APR 11 2015 MID TO HIGH CLOUDS WILL BE AROUND THROUGH MUCH OF THE TAF PERIOD...BUT EXPECT CLOUD BASES WILL BE HIGH ENOUGH TO KEEP CEILINGS VFR THROUGH THE TAF PERIOD. THE WIND WILL BE FROM THE SOUTH THROUGHOUT THE PERIOD AND THE PRIMARY CONCERN WILL BE THE POTENTIAL FOR MARGINAL LOW LEVEL WIND SHEAR...WITH THE FOCUS FOR WIND SHEAR BEING FURTHER WEST NEAR KEAR. THE AXIS OF STRONGER WINDS ALOFT WILL BE WEST OF KGRI AND HENCE WILL KEEP LOW LEVEL WIND SHEAR OUT OF THE KGRI TAF. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...PFANNKUCH SHORT TERM...JCB LONG TERM...EDDY AVIATION...WESELY
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
424 AM EDT SAT APR 11 2015 .SYNOPSIS... A COLD FRONT WILL MOVE OFFSHORE THIS MORNING. HIGH PRESSURE WILL BUILD OVER THE REGION FROM THE NORTH SATURDAY AND SUNDAY. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST TUESDAY AND MOVE OFFSHORE BY EARLY WEDNESDAY. HIGH PRESSURE WILL BUILD INTO THE REGION FOR MIDWEEK. ANOTHER FRONT WILL AFFECT THE AREA BY LATE NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 415 AM SATURDAY...BAND OF CONVECTION FIRED UP ACROSS OUR NORTHERN CWA AND IS NOW MOVING INTO THE PAMLICO SOUND AND OFFSHORE. ONCE THIS ACTIVITY IS OFFSHORE...THE CONVECTIVE THREAT SHOULD END BUT REGIONAL COMPOSITE RADAR SHOWING ADDITIONAL LIGHT SHOWERS APPROACHING FROM THE W/SW. WILL HAVE LIKELY POPS OVER MOST OF THE CWA THROUGH 12Z...THEN TRANSITIONING TO THE COAST THROUGH ABOUT 15Z. THE BULK OF THE PRECIPITATION WILL BE OFFSHORE BY MIDDAY WITH COOLER AND DRIER AIR SLOWLY FILTERING INTO THE REGION WITH MOSTLY SUNNY SKIES INLAND AND PARTIAL SUNSHINE NEAR THE COAST AS TEMPERATURES REMAIN STEADY OR SLOWLY FALL AFTER WARMING A FEW DEGREES AHEAD OF THE FRONT THIS MORNING. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... AS OF 420 AM SATURDAY...NOTICEABLY COOLER AIR OVERTAKES THE REGION TONIGHT AS AXIS OF HIGH PRESSURE BUILDS ACROSS THE EASTERN CAROLINAS AND VIRGINIA. TEMPERATURES WILL DROP INTO THE UPPER 40S AND LOWER 50S WITH LIGHT NORTHEAST WINDS. && .LONG TERM /SUNDAY THROUGH FRIDAY/... AS OF 344 AM SAT...MODELS IN GOOD AGREEMENT THROUGH THE FIRST HALF OF THE EXTENDED PERIOD WITH UPPER RIDGE BUILDING OVER AREA. SEE SOME DISCREPANCIES LATER IN THE WEEK AS TROUGH DIGS INTO THE SOUTHWEST. AT THE SURFACE HIGH PRESSURE OVER THE AREA WILL SHIFT OFFSHORE SUNDAY AND SUNDAY NIGHT WITH LOW LEVEL FLOW BECOMING SOUTHERLY BY MONDAY. FRONT WILL MOVE THROUGH AREA TUESDAY AND WILL SEE AN INCREASE IN POPS AS IT APPROACHES THROUGH THE DAY. SOME TIMING DIFFERENCES...BUT EXPECT THE FRONT TO PASS OFFSHORE LATE IN THE DAY...THEN HANG UP ALONG THE COAST AS STRONG HIGH PRESSURE BUILDS IN WEST OF THE AREA. CURRENT ECMWF SOMEWHAT STRONGER THAN PREVIOUS RUN AS IT DEEPENS LOW OFF THE COAST MORE. HIGH PRESSURE OVER THE AREA WEDNESDAY AND THURSDAY. DIFFERENCES CROP UP IN THE SURFACE FIELDS LATER IN THE WEEK. ECMWF HAS BACKED OFF ON STRENGTH OF COASTAL TROUGH/LOW THURSDAY INTO FRIDAY SO HAVE EASED OFF A BIT ON POPS IN THAT TIME PERIOD. SYSTEM APPROACHES AREA FRIDAY WITH TIMING DIFFERENCES INTO THE WEEKEND. HIGH TEMPERATURES IN THE MID 70S THROUGH MUCH OF THE PERIOD...LOWER 70S BEHIND THE FRONT ON WEDNESDAY && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... SHORT TERM /THROUGH 06Z SUNDAY/... AS OF 1250 AM SATURDAY...PRECIPITATION HAS BEEN LIMITED THUS FAR...BUT 3KM HRRR STILL SHOWS RAIN BLOSSOMING...ESPECIALLY NEAR THE COAST TOWARD MORNING. WILL KEEP A PERIOD OF MVFR CEILINGS JUST AHEAD AND BEHIND FRONT FROM ROUGHLY 09Z TO 14Z THIS MORNING AS THE COLD FRONT SHIFTS OFFSHORE SLOWLY. CONDITIONS IMPROVE TO VFR BY MIDDAY SATURDAY AND CONTINUE INTO SATURDAY NIGHT. LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 347 AM SAT...VFR CONDITIONS SUNDAY AND MONDAY. FRONT APPROACHES THE AREA TUESDAY WITH SUB VFR CONDITIONS POSSIBLE IN ANY PRECIPITATION. DRY CONDITIONS RETURN WEDNESDAY. && .MARINE... SHORT TERM /TODAY AND TONIGHT/... AS OF 425 AM SATURDAY...WHILE WINDS HAVE DROPPED OFF OVER THE SOUNDS AND FAR NORTHERN AND SOUTHERN LEGS...STILL SEEING REPORTS OF GUSTS WELL INTO THE 20S AT DIAMOND BUOY WITH SEAS AT 7 FEET. SMALL CRAFT ADVISORIES WILL REMAIN IN EFFECT FOR THE CENTRAL LEGS UNTIL 10 AM THIS MORNING AND MAY BE NEED TO BE EXTENDED FOR ROUGH SEAS. AS HIGH PRESSURE BUILDS IN BEHIND STRONG COLD FRONT...WINDS SHOULD SUBSIDE FAIRLY QUICKLY TONIGHT...NORTHEAST AT 15 KNOTS OR LESS WITH SEAS GENERALLY 3 TO 5 FEET CENTRAL WATERS AND 2 TO 3 FEET ELSEWHERE. LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 354 AM SAT...HIGH PRESSURE OVER THE AREA SUNDAY WITH NORTHEASTERLY FLOW OVER THE NORTH CAROLINA COASTAL WATERS. HIGH PRESSURE WILL MOVE OFFSHORE SUNDAY NIGHT WITH FLOW BECOMING EASTERLY THEN SOUTHERLY BY MONDAY AFTERNOON AHEAD OF NEXT SYSTEM. GRADIENT WILL TIGHTEN MONDAY NIGHT AND TUESDAY WITH SMALL CRAFT ADVISORY CONDITIONS POSSIBLE IN THE CENTRAL WATERS AHEAD OF THE FRONT. FRONT EXPECTED TO MOVE THROUGH THE WATERS BY TUESDAY EVENING WITH CONDITIONS FALLING BELOW SCA CRITERIA. AS HIGH PRESSURE BUILDS TO THE NORTH GRADIENT WILL TIGHTEN AGAIN ON WEDNESDAY WITH SCA CONDITIONS POSSIBLE AGAIN OVER THE CENTRAL AND SOUTHERN WATERS. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR AMZ152- 154. SMALL CRAFT ADVISORY UNTIL 5 AM EDT EARLY THIS MORNING FOR AMZ156. && $$ SYNOPSIS...CTC NEAR TERM...CTC SHORT TERM...CTC LONG TERM...CCG AVIATION...CCG/CTC MARINE...CCG/CTC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
318 AM EDT SAT APR 11 2015 .SYNOPSIS... A COLD FRONT WILL SLOWLY MOVE ACROSS THE REGION THIS MORNING ACCOMPANIED BY A FEW SHOWERS. DRY HIGH PRESSURE WILL FOLLOW AND BUILD INTO THE CAROLINAS THROUGH THE EARLY NEXT WEEK. A SECOND COLD FRONT WILL MOVE ACROSS THE REGION TUESDAY WITH ANOTHER HIGH PRESSURE FOLLOWING INTO THE MIDWEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1030 PM FRIDAY...SEVERE POTENTIAL CONTINUES TO DIMINISH THIS EVENING AS CONVECTION MOVES INTO A RELATIVELY STABLE AND DRY ATMOSPHERE. HAVE FURTHER RATCHETED BACK ON TIMING...COVERAGE AND STRENGTH OF OVERNIGHT ACTIVITY. ALTHOUGH THE ODD THUNDERSTORM CANNOT BE RULED OUT...WE ARE NOW EXPECTING MORE IN THE WAY OF LIGHT RAIN AND SHOWER ACTIVITY IN THE EARLY MORNING HOURS. PREVIOUS DISCUSSIONS FOLLOW: BASED ON LATEST TRENDS HAVE FURTHER DELAYED TIMING OF SHOWER/THUNDERSTORM PROGRESSION ACROSS THE FORECAST AREA. ISOLATED LIGHT ACTIVITY IS ONLY NOW MAKING ITS WAY INTO OUR FAR NORTHWESTERN COUNTIES AND DO NOT THINK WE WILL SEE ANYTHING MAKE IT TO THE COAST BEFORE ABOUT MIDNIGHT. DEWPOINTS ARE ON THE LOW SIDE AND MUCH OF THE CWA IS NOW WITHIN THE MORE STABLE SECTOR OF THE SEA BREEZE CIRCULATION SO CONFIDENCE IN THE SEVERE THREAT IS LOWER THAN EARLIER THIS AFTERNOON.LATEST HRRR KEEPS BULK OF ACTIVITY WELL INLAND. HAVE MADE APPROPRIATE CHANGES TO THE FORECAST WITH ALL THIS IN MIND. PREVIOUS DISCUSSION FOLLOWS: BETWEEN THE STABILIZING EFFECTS OF THE SEA BREEZE AN THE SLOWER THAN EXPECTED ARRIVAL OF THE COLD FRONT FORCED CONVECTION THE SEVERE WEATHER THREAT HAS DIMINISHED. SAT IMAGERY SHOWS MINIMAL DEVELOPMENT IN CU FIELDS DESPITE THE WARM AND HUMID AFTERNOON. SIMILARLY THE ISOLATED ACTIVITY TO OUR WEST MAY HAVE TROUBLE SURVIVING INTO OUR REGION DUE TO THE DRYNESS INDICATED IN THE LCL- LFC LAYER. BUT JUST IN CASE HAVE BEEN CARRYING LOW POPS OVER WESTERN ZONES BEGINNING AROUND 21Z. THIS IS A BIT QUICKER THAN THE WRF BUT SLOWER THAN THE NOW OUTLYING GFS. THE MOST UNCERTAINTY HAS COME THIS AFTERNOON FROM THE HIGH RES MODELS SUCH AS THE RUC AND THE HRRR. SUCH GUIDANCE HAS CONSISTENTLY SHOWN ANY AND ALL PREFRONTAL PRECIPITATION DETERIORATE COMPLETE. TAKE THE HRRR FOR EXAMPLE...NOT A DROP OF RAIN UNTIL SOME FAIRLY BENIGN LOOKING SHALLOW CONVECTION ENTERS OUR AREA...AT 04Z! CURRENT FORECAST IS NOT SO BOLDLY DRY BUT JUST RECENTLY NOTICED THAT THE PREFRONTAL TROUGH DEPICTED ON THE WRF IS MUCH TOO STRONG COMPARED TO REALITY. SO THE TREND STARTED THIS MORNING OF SLOWING DOWN TIMING MAY VERY WELL CONTINUE THIS EVENING WITH JUST A SLOW RAMPING UP OF POPS FROM NW TO SE...BUT THE BULK OF THE RAIN COMING LATE OVERNIGHT AND GENERALLY SHALLOW CONVECTION WITH JUST ISOLATED THUNDER. THE REMAINING SEVERE THREAT IS OVER FAR INLAND ZONES WITH ANY PREFRONTAL ACTIVITY THAT MANAGES TO DEVELOP OR ADVECT IN FROM THE WEST...REPRESENTING A LOW END DAMAGING WIND THREAT. && .SHORT TERM /SUNDAY MORNING THROUGH MONDAY NIGHT/... AS OF 330 AM SATURDAY...A ZONAL MID LEVEL PATTERN WILL BE SHORT LIVED AS A MEANDERING CLOSED LOW OVER THE SOUTHWEST ALONG WITH NORTHERN STREAM TROUGHING MAKE THEIR RESPECTIVE MOVES EAST. MODEST RIDGING DEVELOPS EARLY MONDAY AHEAD OF THESE SYSTEMS BEFORE A BROAD SOUTHWEST FLOW DEVELOPS LATE MONDAY INTO TUESDAY MORNING. THIS WILL SERVE TO INCREASE PWS FROM A PALTRY 0.15 INCHES TO WELL OVER AN INCH BY TUESDAY MORNING. AT THE SURFACE HIGH PRESSURE WILL BE CENTERED BASICALLY OVERHEAD SUNDAY THEN MOVE WELL OFFSHORE BY TUESDAY MORNING. LOW PRESSURE ASSOCIATED WITH AN EJECTING VORT...NOT THEM MAIN SYSTEM MOVES ACROSS THE TENNESSEE VALLEY BY TUESDAY MORNING AS WELL. WITH THE RIDGE IN PLACE...MODELS SEEM TO HAVE DELAYED THE MOISTURE SLIGHTLY AND THIS IS REFLECTED IN THE LATEST FORECAST. THE ONLY CHANGE IN THE TEMPERATURE FORECAST WAS TO RAISE HIGHS FOR MONDAY WITH THE LOWER POPS. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 330 AM SATURDAY...A RATHER ACTIVE SCENARIO FOR THE EXTENDED PERIOD. AN ELONGATED AND COMPLEX SYSTEM WILL MOVE ACROSS THE AREA TUESDAY FOLLOWED BY A WEDGE SCENARIO FOR WEDNESDAY AND THURSDAY AS WEAK RIDGING BUILDS ALOFT. TRENDED POPS DOWN FOR THESE DAYS ALTHOUGH THEY CANNOT BE REMOVED COMPLETELY AS SOME ISENTROPIC LIFT IS NOTED IN THE GUIDANCE. POPS TREND BACK UP SLIGHTLY FOR THE END OF THE PERIOD AS A SOUTHWEST FLOW ALOFT DEVELOPS WITH THE APPROACH OF A DECENT TROUGH AND ASSOCIATED COLD FRONT. TEMPERATURE REGIME LOOKS VERY STABLE WITH HIGHS IN THE 70S AND LOWS IN THE 50S. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... AS OF 06Z...WILL GO WITH MAINLY LIGHT CONVECTION ALONG AND AHEAD OF THE COLD FRONT...WITH NO MENTION OF THUNDER...THROUGH DAYBREAK SAT. THE INLAND TERMS WILL SEE THE CFP PRIOR TO SUNRISE...WITH THE COASTAL TERMS TAKING UP TO 4 TO 6 HRS THERE-AFTER. LOOK FOR ACTIVE SW WINDS AT 5 TO 10 KT...VEER TO THE N AROUND 10 KT AFTER THE CFP...AND FURTHER VEER TO THE NE AT 10 TO 15 KT BY LATE MORNING THRU SAT AFTN. COULD SEE A FEW HRS OF LIGHT RAIN OR SHOWERS AND LOW CEILINGS IMMEDIATELY AFTER THE CFP...BUT LOOK FOR QUICKLY IMPROVING CEILINGS BY MIDDAY AND AFTERNOON. EXTENDED OUTLOOK...EXPECT VFR CONDITIONS SUNDAY THROUGH TUESDAY...WITH POSSIBLE MVFR EACH MORNING FROM BR. POSSIBLE MVFR/IFR DEVELOPING DURING TUE INTO WED DUE TO INCREASING RAIN CHANCES FROM AN APPROACHING COLD FRONT. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 PM...NO CHANGES TO THE FORECAST WITH THE LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS: SOUTHWESTERLY FLOW EXPECTED THROUGH THE PERIOD IN A PRE-FRONTAL FLOW REGIME. THE APPROACH OF THE BOUNDARY LATE TONIGHT WILL TIGHTEN THE GRADIENT SOMEWHAT LEADING TO A SMALL INCREASE IN WINDS AND SEAS. WHILE THIS MAY INTRODUCE 5 FT SEAS ALONG THE OUTER PORTIONS OF SOME OF THE FORECAST ZONES THE LARGE COAST- PARALLEL COMPONENT SHOULD SPONSOR ENOUGH OF A GRADIENT IN NEARSHORE VS OFFSHORE WAVES TO PRECLUDE A SCEC. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 330 AM SATURDAY...NORTHEAST WINDS WILL CONTINUE FOR SOME TIME SUNDAY WITH SPEEDS OF 15-20 KNOTS. BY SUNDAY EVENING THE FLOW WILL DIMINISH AND VEER TO THE EAST AS HIGH PRESSURE MOVES OFFSHORE. BY LATE MONDAY MORNING A SOUTHEAST RETURN FLOW WILL BE FIRMLY IN PLACE. SPEEDS AT THIS TIME WILL BE 10-15 KNOTS. THE FLOW WILL VEER FURTHER BY TUESDAY MORNING TO SOUTHERLY. SEAS DURING THIS TIME WILL BE 2-4 FEET WITH THE HIGHEST VALUES OCCURRING SUNDAY AND LATE IN THE PERIOD. LONG TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 330 AM SATURDAY...A SOUTHERLY FLOW EARLY WILL SWITCH TO THE NORTH...NORTHEAST BY DAYS END TUESDAY AS LOW PRESSURE MOVES ACROSS THE AREA AND OFFSHORE. THE NORTHEASTERLY FLOW WILL INCREASE SLIGHTLY WEDNESDAY AS A WEDGE SCENARIO STRENGTHENS. OVERALL WIND SPEEDS WILL BE 10-15 KNOTS...LOWER TUESDAY AND HIGHER WEDNESDAY. SIGNIFICANT SEAS WILL BE 2-4 FEET. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...SHK NEAR TERM...REK/MBB SHORT TERM...SHK LONG TERM...SHK AVIATION...DCH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
215 AM EDT SAT APR 11 2015 .SYNOPSIS... A COLD FRONT WITH SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE AREA OVERNIGHT...WITH SHOWERS LINGERING INTO EARLY SATURDAY MORNING. DRY HIGH PRESSURE WILL FOLLOW AND BUILD INTO THE CAROLINAS THROUGH THE EARLY NEXT WEEK. A SECOND COLD FRONT WILL MOVE ACROSS THE REGION TUESDAY WITH ANOTHER HIGH PRESSURE FOLLOWING INTO THE MIDWEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1030 PM FRIDAY...SEVERE POTENTIAL CONTINUES TO DIMINISH THIS EVENING AS CONVECTION MOVES INTO A RELATIVELY STABLE AND DRY ATMOSPHERE. HAVE FURTHER RATCHETED BACK ON TIMING...COVERAGE AND STRENGTH OF OVERNIGHT ACTIVITY. ALTHOUGH THE ODD THUNDERSTORM CANNOT BE RULED OUT...WE ARE NOW EXPECTING MORE IN THE WAY OF LIGHT RAIN AND SHOWER ACTIVITY IN THE EARLY MORNING HOURS. PREVIOUS DISCUSSIONS FOLLOW: BASED ON LATEST TRENDS HAVE FURTHER DELAYED TIMING OF SHOWER/THUNDERSTORM PROGRESSION ACROSS THE FORECAST AREA. ISOLATED LIGHT ACTIVITY IS ONLY NOW MAKING ITS WAY INTO OUR FAR NORTHWESTERN COUNTIES AND DO NOT THINK WE WILL SEE ANYTHING MAKE IT TO THE COAST BEFORE ABOUT MIDNIGHT. DEWPOINTS ARE ON THE LOW SIDE AND MUCH OF THE CWA IS NOW WITHIN THE MORE STABLE SECTOR OF THE SEA BREEZE CIRCULATION SO CONFIDENCE IN THE SEVERE THREAT IS LOWER THAN EARLIER THIS AFTERNOON.LATEST HRRR KEEPS BULK OF ACTIVITY WELL INLAND. HAVE MADE APPROPRIATE CHANGES TO THE FORECAST WITH ALL THIS IN MIND. PREVIOUS DISCUSSION FOLLOWS: BETWEEN THE STABILIZING EFFECTS OF THE SEA BREEZE AN THE SLOWER THAN EXPECTED ARRIVAL OF THE COLD FRONT FORCED CONVECTION THE SEVERE WEATHER THREAT HAS DIMINISHED. SAT IMAGERY SHOWS MINIMAL DEVELOPMENT IN CU FIELDS DESPITE THE WARM AND HUMID AFTERNOON. SIMILARLY THE ISOLATED ACTIVITY TO OUR WEST MAY HAVE TROUBLE SURVIVING INTO OUR REGION DUE TO THE DRYNESS INDICATED IN THE LCL- LFC LAYER. BUT JUST IN CASE HAVE BEEN CARRYING LOW POPS OVER WESTERN ZONES BEGINNING AROUND 21Z. THIS IS A BIT QUICKER THAN THE WRF BUT SLOWER THAN THE NOW OUTLYING GFS. THE MOST UNCERTAINTY HAS COME THIS AFTERNOON FROM THE HIGH RES MODELS SUCH AS THE RUC AND THE HRRR. SUCH GUIDANCE HAS CONSISTENTLY SHOWN ANY AND ALL PREFRONTAL PRECIPITATION DETERIORATE COMPLETE. TAKE THE HRRR FOR EXAMPLE...NOT A DROP OF RAIN UNTIL SOME FAIRLY BENIGN LOOKING SHALLOW CONVECTION ENTERS OUR AREA...AT 04Z! CURRENT FORECAST IS NOT SO BOLDLY DRY BUT JUST RECENTLY NOTICED THAT THE PREFRONTAL TROUGH DEPICTED ON THE WRF IS MUCH TOO STRONG COMPARED TO REALITY. SO THE TREND STARTED THIS MORNING OF SLOWING DOWN TIMING MAY VERY WELL CONTINUE THIS EVENING WITH JUST A SLOW RAMPING UP OF POPS FROM NW TO SE...BUT THE BULK OF THE RAIN COMING LATE OVERNIGHT AND GENERALLY SHALLOW CONVECTION WITH JUST ISOLATED THUNDER. THE REMAINING SEVERE THREAT IS OVER FAR INLAND ZONES WITH ANY PREFRONTAL ACTIVITY THAT MANAGES TO DEVELOP OR ADVECT IN FROM THE WEST...REPRESENTING A LOW END DAMAGING WIND THREAT. && .SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/... AS OF 330 PM FRIDAY...THE COLD FRONT IS EXPECTED TO BE JUST OFF THE COAST BY 12 UTC WITH LINGERING EARLY MORNING SHOWERS. AFTER THE PRECIPITATION CLEARS SATURDAY MORNING...DRIER HIGH PRESSURE WILL FILTER INTO THE AREA THROUGH THE REMAINDER OF THE OF THE WEEKEND. HIGH TEMPERATURES BOTH DAYS WILL BE IN THE 74 TO 78 DEGREE RANGE WITH RELATIVE HUMIDITY VALUES DROPPING INTO THE LOWER TO MIDDLE 30% RANGE LATE IN THE DAY. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 330 PM FRIDAY...WETTISH EXTENDED PERIOD AS UPSTREAM UPPER TROUGHING ALLOWS GULF MOISTURE TAPS TO EJECT NE INTO THE EASTERN CAROLINAS TUESDAY THROUGH FRIDAY. FIRST IMPULSE GUIDED FROM THE MISSISSIPPI DELTA STREAMS NE IN AN ELEVATED PRECIPITABLE WATER PLUME AS HIGH PRESSURE ANCHORS FROM THE NORTH TO INSTIGATE AN EARLY SPRING OVER-RUNNING WEDGE PATTERN INTO WEDNESDAY. HIGHLY AMPLIFIED UPPER TROUGH EDGES EAST OVER THE VALLEY OVERSPREADING GULF VAPOR CONTENT THURSDAY AS THE WEDGE ERODES IN WET AND ISENTROPIC OMEGA. EXTENDED PERIOD CULMINATES INTO A RAINY FRIDAY AS THE AMPED UPPER TROUGH FORCES A COLD FRONT ACROSS FORECAST AREA DAY 7. WPC QPF DEPICTIONS FOR DAYS 4-5 AND 6-7 YIELD BASIN AVERAGE COLLECTIVE RAIN TOTALS OF 1-2.5 INCHES. PLENTIFUL CLOUDS IN BALMY SW FLOW ALOFT AND WEDGE PATTERN THIS PERIOD RESULTS IN MAXIMUMS PRIMARILY 70S...MINIMUMS UPPER 50S TO LOWER 60S. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... AS OF 06Z...WILL GO WITH MAINLY LIGHT CONVECTION ALONG AND AHEAD OF THE COLD FRONT...WITH NO MENTION OF THUNDER...THROUGH DAYBREAK SAT. THE INLAND TERMS WILL SEE THE CFP PRIOR TO SUNRISE...WITH THE COASTAL TERMS TAKING UP TO 4 TO 6 HRS THERE-AFTER. LOOK FOR ACTIVE SW WINDS AT 5 TO 10 KT...VEER TO THE N AROUND 10 KT AFTER THE CFP...AND FURTHER VEER TO THE NE AT 10 TO 15 KT BY LATE MORNING THRU SAT AFTN. COULD SEE A FEW HRS OF LIGHT RAIN OR SHOWERS AND LOW CEILINGS IMMEDIATELY AFTER THE CFP...BUT LOOK FOR QUICKLY IMPROVING CEILINGS BY MIDDAY AND AFTERNOON. EXTENDED OUTLOOK...EXPECT VFR CONDITIONS SUNDAY THROUGH TUESDAY...WITH POSSIBLE MVFR EACH MORNING FROM BR. POSSIBLE MVFR/IFR DEVELOPING DURING TUE INTO WED DUE TO INCREASING RAIN CHANCES FROM AN APPROACHING COLD FRONT. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 PM...NO CHANGES TO THE FORECAST WITH THE LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS: SOUTHWESTERLY FLOW EXPECTED THROUGH THE PERIOD IN A PRE-FRONTAL FLOW REGIME. THE APPROACH OF THE BOUNDARY LATE TONIGHT WILL TIGHTEN THE GRADIENT SOMEWHAT LEADING TO A SMALL INCREASE IN WINDS AND SEAS. WHILE THIS MAY INTRODUCE 5 FT SEAS ALONG THE OUTER PORTIONS OF SOME OF THE FORECAST ZONES THE LARGE COAST- PARALLEL COMPONENT SHOULD SPONSOR ENOUGH OF A GRADIENT IN NEARSHORE VS OFFSHORE WAVES TO PRECLUDE A SCEC. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 330 PM FRIDAY...WINDS OVER THE WATERS WILL BE SHIFTING TO THE NORTHWEST WITH THE FRONTAL PASSAGE AND THEN NORTHEAST TO EAST LATE SATURDAY INTO SUNDAY. WINDS SPEEDS WILL BE 15 TO 20 KNOTS EARLY IN THE MORNING BEFORE DROPPING DOWN TO 15 KNOTS BY THE EVENING. ON SUNDAY THE PRESSURE GRADIENT TIGHTENS AND WINDS ARE EXPECT TO PEAK AGAIN AT 15 TO 20 KNOTS SUNDAY MORNING BEFORE DROPPING BACK TO 10 TO 15 KNOTS OVERNIGHT SUNDAY. SEAS WILL BE RUNNING AROUND 3 TO 5 FEET SATURDAY MORNING WITH A FALL TO 2 TO 4 FEET SATURDAY AFTERNOON WITH THE OFFSHORE FLOW. WITH THE NORTHEAST FLOW INCREASING THE SEAS WILL INCREASE BACK TO 3 TO 4 FEET ON SUNDAY. LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 330 PM FRIDAY...A BUMPY MARINE ENVIRONMENT MON-WED AS A MODERATE ONSHORE WIND FLOW KEEPS SEAS SLIGHTLY ELEVATED...AND OVERALL 3-5 FEET. UNSETTLED CONDITIONS MAY PLAGUE THE WATERS WITH RAIN AND OCCASIONAL REDUCED VISIBILITY AND ISOLATED TSTMS AS GULF MOISTURE AND DISTURBANCES SPREAD NE OVER THE 0-20 NM WATERS. SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE WEDNESDAY FOR 6 FOOT SEAS OFFSHORE...AS HIGH PRESSURE BUILDS SOUTH AND INTERACTS WITH AN OFFSHORE COASTAL TROUGH. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...DRH NEAR TERM...REK/MBB SHORT TERM...DRH LONG TERM...MJC AVIATION...DCH
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1256 AM EDT SAT APR 11 2015 .SYNOPSIS... A STRONG COLD FRONT WILL APPROACH FROM THE WEST AND SWEEP ACROSS THE AREA LATE TONIGHT. HIGH PRESSURE WILL BUILD OVER THE REGION FROM THE NORTH SATURDAY AND SUNDAY. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST LATER MONDAY AND MOVE ACROSS THE AREA LATE TUESDAY. HIGH PRESSURE WILL BUILD INTO THE REGION FOR MIDWEEK. A WARM FRONT WILL LIFT NORTH THROUGH THE AREA FRIDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1235 AM SATURDAY...COLD FRONT MAKING VERY SLOW PROGRESS ACROSS THE STATE...CURRENTLY MOVING INTO THE TRIAD REGION. CONVECTION HAD A HARD TIME GETTING ITS ACT TOGETHER THIS EVENING AND HAVE LOWERED POPS A BIT FOR THE EARLY PART OF THE OVERNIGHT HOURS. RADAR DOES INDICATE A FEW SHOWERS STARTING TO DEVELOP WEST OF GOLDSBORO. LATEST RUN OF THE 3KM HRRR STILL SHOWS PRECIPITATION BLOSSOMING AROUND 08Z OR 09Z...MAINLY NEAR THE COAST AND CONTINUING INTO MID-MORNING...HAVE RAMP POPS BACK UP TO LIKELY NEAR THE COAST AFTER 09Z. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/... AS OF 235 PM FRIDAY...LINGERING SHOWERS EARLY COAST IN WAKE OF FRONT THEN CLEARING FROM WEST TO EAST LATER IN MORNING INTO THE AFTERNOON AS HIGH PRESSURE BUILDS NORTH OF REGION. CAA NOT OVERLY STRONG BEHIND FRONT AND WITH SOME SUN SHOULD SEE NEAR NORMAL HIGHS IN LOW TO MID 70S SW TO MID 60S NE. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... AS OF 230 PM FRI...GFS AND ECMWF IN GOOD AGREEMENT THROUGH EARLY NEXT WEEK...BUT AFTER THAT THE GFS IS FASTER THAN THE ECMWF. WPC SURFACE GRAPHICS MATCH UP BETTER WITH ECMWF SO WILL USE IT FOR THE LONG TERM FORECAST. HIGH PRESSURE OVER THE MID ATLANTIC THIS WEEKEND WILL SHIFT EAST MONDAY. MOISTURE WILL INCREASE AS WINDS BECOME SOUTHEAST MONDAY THEN SOUTHWEST TUESDAY. COLD FRONT WILL APPROACH DURING THE DAY TUESDAY AND WILL KEEP POPS IN THE CHANCE CATEGORY. THE COLD FRONT WILL MOVE OFF THE COAST IN THE EVENING AND BECOME STATIONARY TO THE SOUTH WEDNESDAY AND THURSDAY WITH DRY CONDITIONS ACROSS THE AREA. CHANCE POPS RETURN FRIDAY AS THE FRONT TO THE SOUTH MOVES BACK NORTH ALONG WITH AN APPROACHING SHARP UPPER TROF. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... SHORT TERM /THROUGH 06Z SUNDAY/... AS OF 1250 AM SATURDAY...PRECIPITATION HAS BEEN LIMITED THUS FAR...BUT 3KM HRRR STILL SHOWS RAIN BLOSSOMING...ESPECIALLY NEAR THE COAST TOWARD MORNING. WILL KEEP A PERIOD OF MVFR CEILINGS JUST AHEAD AND BEHIND FRONT FROM ROUGHLY 09Z TO 14Z THIS MORNING AS THE COLD FRONT SHIFTS OFFSHORE SLOWLY. CONDITIONS IMPROVE TO VFR BY MIDDAY SATURDAY AND CONTINUE INTO SATURDAY NIGHT. LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 230 PM FRI...VFR/DRY THROUGH MONDAY NIGHT. SCATTERED SHOWERS TUESDAY WITH THUNDERSTORMS POSSIBLE IN THE AFTERNOON AHEAD OF A COLD FRONT. THE FRONT MOVES OFF THE COAST TUESDAY EVENING. VFR/DRY CONDITIONS RETURN WED. LIGHT EAST WINDS SUNDAY BECOME SOUTHEAST MONDAY. SOUTHWEST WINDS TUESDAY AHEAD OF THE FRONT THEN NORTHEAST WEDNESDAY. && .MARINE... SHORT TERM /TONIGHT AND SATURDAY/... AS OF 1255 AM SATURDAY...HAVE DROPPED THE SMALL CRAFT ADVISORY OVER THE PAMLICO SOUND AND FAR SOUTHERN WATERS BASED ON CURRENT OBSERVATIONS. GUSTY SOUTHWEST WINDS CONTINUE ON THE COASTAL WATERS NORTH OF OCRACOKE...ESPECIALLY NEAR DIAMOND BUOY AND DUCK WITH GUSTS TO NEAR 25 KNOTS. SEAS WILL BE GENERALLY 3 TO 5 FEET BUT WITH SOME 6 FT SEAS FOR THE OUTER PORTIONS OF THE COASTAL WATERS. WINDS WILL SHIFT TO NW TO N TOWARD DAYBREAK. COULD BE A PERIOD OF 15-20 KT N/NE WINDS IN WAKE OF FRONT SAT MORNING THEN AS HIGH PRESSURE BUILDS IN SPEEDS WILL DIMINISH INTO THE AFTERNOON. EXTENDED SCA SAT MORNING CENTRAL WATERS FOR POSSIBLY SOME LINGERING 6 FT SEAS THEN SEAS SHOULD SUBSIDE TO 2-4 FEET LATE SATURDAY. LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 230 PM FRI...NORTHEAST FLOW ACROSS THE MARINE ZONES SATURDAY NIGHT AND SUNDAY WITH HIGH PRESSURE OVER THE MID ATLANTIC. THE HIGH SHIFTS EAST MONDAY WITH WINDS BECOMING SOUTHEAST. WINDS WILL VEER FURTHER TO SOUTHWEST TUESDAY AS A COLD FRONT APPROACHES FROM THE WEST. THE FRONT MOVES OFF THE COAST TUESDAY EVENING WITH WINDS BECOMING NORTHEAST AND CONTINUING INTO WEDNESDAY. WIND SPEEDS FORECAST TO REMAIN BELOW 25 KNOTS. HOWEVER WINDS FORECAST TO BUILD TO 4-6 FEET TUESDAY INTO WEDNESDAY IN THE WATERS FROM OREGON INLET TO CAPE LOOKOUT. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR AMZ152- 154. SMALL CRAFT ADVISORY UNTIL 5 AM EDT EARLY THIS MORNING FOR AMZ156. SMALL CRAFT ADVISORY UNTIL 2 AM EDT EARLY THIS MORNING FOR AMZ150. && $$ SYNOPSIS...RF NEAR TERM...CTC SHORT TERM...RF LONG TERM...HSA AVIATION...CTC/HSA MARINE...CTC/DAG/HSA
AREA FORECAST DISCUSSION
NWS TULSA OK
420 AM CDT SAT APR 11 2015 .DISCUSSION... UNSETTLED WEATHER WILL BE THE RULE OVER THE NEXT WEEK. SHOWERS AND A FEW THUNDERSTORMS ARE TRYING TO MOVE INTO PARTS OF EASTERN OKLAHOMA THIS MORNING BUT ARE HAVING SOME DIFFICULTY OVERCOMING THE DRY LOW LEVEL AIR IN PLACE. OVERALL PRECIPITATION COVERAGE AND INTENSITY IS EXPECTED TO REMAIN RATHER LOW IN OUR AREA TODAY ALTHOUGH THE HRRR DOES INDICATE AT LEAST ISOLATED ACTIVITY CONTINUING MUCH OF THE DAY. EXPECT TO SEE ENOUGH SUN THROUGH THE MID LEVEL CLOUDINESS TO ALLOW AFTERNOON TEMPERATURES TO WARM INTO THE 70S. SHOWER AND THUNDERSTORM CHANCES WILL BE HIGHEST NEAR THE KANSAS BORDER TONIGHT AND WILL BEGIN TO RAMP UP ACROSS THE AREA SUNDAY. THE MOST WIDESPREAD RAINFALL IS STILL EXPECTED SUNDAY NIGHT INTO MONDAY AS A COLD FRONT DROPS SOUTH THROUGH THE AREA. RAIN CHANCES WILL CONTINUE INTO MIDWEEK AS THE UPPER LEVEL STORM SYSTEM WILL LAG BACK OVER THE AREA. ANOTHER UPPER LEVEL SYSTEM WILL MOVE INTO THE AREA THURSDAY WITH MOST MODELS DEVELOPING A CLOSED UPPER LOW IN TEH VICINITY BY LATE WEEK. THIS WILL KEEP RAIN CHANCES GOING THROUGH THE END OF THE WEEK ALONG WITH COOLER TEMPERATURES. STAYED CLOSE TO GUIDANCE TEMPERATURES THE NEXT COUPLE DAYS. && .PRELIMINARY POINT TEMPS/POPS... TUL 74 57 79 61 / 20 20 30 70 FSM 75 54 80 63 / 10 10 40 60 MLC 75 58 77 61 / 20 10 40 70 BVO 73 54 80 58 / 20 20 30 70 FYV 72 53 77 59 / 10 10 30 60 BYV 73 52 76 59 / 10 10 20 60 MKO 74 55 78 61 / 20 10 30 60 MIO 73 52 78 58 / 20 20 30 70 F10 74 58 77 61 / 20 10 30 60 HHW 74 57 76 63 / 10 10 50 80 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ SHORT TERM...14 LONG TERM....05 PLATE
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
341 AM CDT SAT APR 11 2015 .SHORT TERM (TODAY THROUGH SUNDAY NIGHT)...GOOD CHANCES FOR RAINFALL THE NEXT 48 HOURS ACROSS SOUTH-CENTRAL TEXAS. A MOIST MID AND UPPER LEVEL TAP FROM THE PACIFIC WILL CONTINUE OVERHEAD. THE LOWEST LEVELS ARE CURRENTLY RELATIVELY DRY BEHIND YESTERDAYS COLD FRONT...ESPECIALLY ACROSS NORTHERN AREAS WHERE DEW POINTS ARE IN THE LOW 50S. THIS WILL MODIFY AS A WARM FRONT LIFTS BACK NORTH THROUGH THE AREA DURING THE MORNING...AND LOW LEVEL H85 THETA-E ADVECTION SETS UP OVER THE REGION THROUGH TOMORROW. PWAT VALUES ARE FORECAST TO INCREASE TO AROUND 1.5-1.7 INCHES BY THIS AFTERNOON AND CLOSER TO 1.8-1.9 INCHES EAST OF I-35 SUNDAY AND SUNDAY NIGHT...WELL ABOVE 2 STANDARD DEVIATIONS OF THE MEAN FOR THIS TIME OF YEAR. THE WARM FRONT LIFTING BACK THROUGH THE AREA WILL SERVE AS FOCUS FOR FORCING TODAY. HAVE FOLLOWED CLOSER TO THE HRRR AND SREF THROUGH THE NEXT 12 HOURS...WHICH SEEM TO BE RELATIVELY BETTER WITH ONGOING CONVECTION SOUTH AND WEST OF THE CWA. WITH NO CAP IN PLACE...SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP MID MORNING ACROSS THE WESTERN AND SOUTHERN CWA AND EXPANDING NORTHEAST THROUGH THE AFTERNOON. AN UPPER LEVEL LOW OFF THE SOUTHERN CALIFORNIA COAST WILL MOVE EAST THROUGH BAJA CALIFORNIA TONIGHT...AND THROUGH NORTHERN MEXICO AND INTO FAR WEST TEXAS SUNDAY AND SUNDAY NIGHT. TIMING OF MID LEVEL DISTURBANCES IN THE SOUTHWEST FLOW ALOFT IS DIFFICULT. GENERALLY ECMWF AND GFS ARE SHOWING TONIGHT THROUGH SUNDAY MORNING FORCING INCREASING OUT OF SOUTH AND DEEP SOUTH TEXAS THROUGH EASTERN PORTIONS OF THE EWX CWA...AND THEN A SECOND DISTURBANCE LATE SUNDAY NIGHT INTO MONDAY MORNING COMING OUT OF MEXICO WEST TO EAST ACROSS THE EWX CWA. THE UPPER LEVEL PATTERN BECOMES BROADLY DIFFLUENT OVER THE REGION SUNDAY AND SUNDAY NIGHT BETWEEN AFOREMENTIONED UPPER LEVEL LOW TO THE WEST-NORTHWEST AND SOUTHERN STREAM SUBTROPICAL JET STREAK ACROSS DEEP SOUTH TEXAS AND MEXICO. THIS ALL INDICATES HIGH CHANCES FOR MULTIPLE ROUNDS OF PRECIP THROUGH EARLY MONDAY MORNING. CAN NOT RULE OUT A FEW STRONGER STORMS...MAINLY SOUTHERN AND WESTERN AREAS WHERE DEEP LAYER SHEAR IS BETTER...BUT OVERALL THE MOIST NATURE OF THE COLUMN LOOKS MORE OF INDICATIVE OF LOCALLY HEAVY RAIN POTENTIAL. RAINFALL TOTALS THROUGH MONDAY MORNING LOOK TO AVERAGE AROUND 1/2 TO 1 INCH ALONG THE RIO GRANDE...1 TO 2 INCHES ACROSS THE HILL COUNTRY AND I-35 CORRIDOR...AND 2 TO 3 INCHES EAST OF I-35. A FEW POCKETS OF HEAVIER RAINFALL TOTALS ARE POSSIBLE...ESPECIALLY SOUTHERN AND EASTERN AREAS. && .LONG TERM (MONDAY THROUGH FRIDAY)...DRIER AIR DOES WORK INTO THE RIO GRANDE AND HILL COUNTRY ON MONDAY WITH DECREASING POPS WEST TO EAST. THE UPPER LEVEL LOW EVENTUALLY OPENS AND SHEARS NORTHEAST MONDAY NIGHT AND TUESDAY...AND A WEAK COLD FRONT ENTERS SOUTH- CENTRAL TEXAS TUESDAY. SHOULD SEE ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS TUESDAY WITH DEEP MOISTURE STILL POOLED ALONG AND EAST OF THE I-35 CORRIDOR. EVENTUALLY THE UPPER LEVEL TROUGH DEEPENS THROUGH THE ROCKIES AND INTO THE PLAINS WEDNESDAY INTO THURSDAY...SENDING A STRONGER COLD FRONT INTO THE AREA ON THURSDAY OR THURSDAY NIGHT. WITH A STRONG SUB-TROPICAL TAP FROM THE PACIFIC CONTINUING IT APPEARS ANOTHER GOOD CHANCE FOR PRECIP WILL OCCUR DURING THIS TIME. DRIER AND MORE SEASONAL CONDITIONS FRIDAY INTO SATURDAY. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 74 66 78 65 82 / 60 70 70 90 40 AUSTIN BERGSTROM INTL AIRPORT 74 66 77 65 81 / 60 70 70 90 40 NEW BRAUNFELS MUNI AIRPORT 76 66 78 64 84 / 60 70 70 90 40 BURNET MUNI AIRPORT 72 64 77 63 81 / 60 60 60 80 40 DEL RIO INTL AIRPORT 77 66 80 63 85 / 60 40 50 70 10 GEORGETOWN MUNI AIRPORT 73 65 76 65 81 / 50 70 70 80 40 HONDO MUNI AIRPORT 75 66 79 64 84 / 60 60 60 90 20 SAN MARCOS MUNI AIRPORT 75 66 77 65 82 / 60 70 70 90 40 LA GRANGE - FAYETTE REGIONAL 76 68 77 68 81 / 60 60 70 80 50 SAN ANTONIO INTL AIRPORT 74 67 79 66 83 / 60 70 60 90 30 STINSON MUNI AIRPORT 75 68 79 66 84 / 60 70 60 90 30 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...76 SYNOPTIC/GRIDS...04
AREA FORECAST DISCUSSION
NWS MIDLAND/ODESSA TX
1231 AM CDT Sat Apr 11 2015 .DISCUSSION... See 06Z aviation discussion below. && .AVIATION... Some showers possible later tonight into Saturday morning though lightning will be isolated. Some MVFR CIGs are possible near sunrise with MAF the most likely TAF site to be affected. The last half of the TAF period appears very favorable for aviation interests. Hennig && .PREV DISCUSSION... /ISSUED 150 PM CDT Fri Apr 10 2015/ DISCUSSION... SE-E surface winds have increased across the Trans Pecos/PB this PM as surface high moves e and surface pressure falls. Upslope flow per mesoscale models (TTU WRF, NAM12, HRRR) looks well organized, enuf so that dwpnts will increase to near 50 on on east slopes of Davis Mtns and M50s thru Glass Mtns. Instability looks to be modulated by mid level LRs of 7.5 C/KM and 0-1km CAPES increase by 00Z to near 1500 J/KG in said area. Looks to be a good set-up for tstms to initiate in the mtns where SB CINH not much of an issue and then move e-ne. Kinematics are also favorable for severe wx (large hail) with 0-6 km bulk shear 40-50kts. In this set-up, the surface thermal ridge and axis of highest dwpnts are near co-located. HRRR develops QPF at 22Z NW of FST and depicts what may well be a right-moving supercell across Pecos Co later this PM. Overnight there is an indication that the arrival energy assocd shrtwv trof in the sw flow aloft and 40kt LLJ may renew the development of convection, especially s of I-20. Convective potential will wane Sat, but still exists. Isold-Sct tstms INVOF Davis/Glass Mtns and across the ern PB, respectively. Sunday more robust PoPs are warranted with backed mid level flow ahead of an upper low sw of El Paso City, helping to hold low level mstr in place. 5h jet of 50-60kts will help provide lift. 0-6km bulk shear increases late, but LR/s are not very good, so for now severe potential looks to be minimized. There`s enuf of a backed flow/mstr/potential for rain cooled air to keeps temps INVOF of normal ranges thru Sunday. Said low will lift newd to w-nw of MAF and this will increase the PoPs Monday n of the area, moreso in the LBB area. However cool mid levels near the center of low will be enough to keep sct PoPs, especially along n of I-20. An assocd cold front will pass thru the area either Mon PM or Mon night, so cooler and drier Tue. Another front will be possible Wed night/Thursday morning, so cool/dry for Thur PM. We`ll watch for the potential for low level mstr return Friday which will augment PoPs. && .MAF WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...NONE. && $$ 10 Follow us on Facebook and Twitter at: http://facebook.com/NWSMidland http://twitter.com/NWSMidland Check us out on the internet at: http://weather.gov/midland
EAST CENTRAL FLORIDA FORECAST DISCUSSION
NWS MELBOURNE FL
946 AM EDT SAT APR 11 2015 .DISCUSSION... ...A FEW STRONG STORMS POSSIBLE THIS AFTERNOON... LTST SOUNDING FROM XMR SHOWS A FAVORABLE SETUP IN PLACE FOR EAST CENTRAL FLORIDA STORM DEVELOPMENT THIS AFTERNOON. PWAT HAS INCREASED TO ~1.6 INCHES ALONG WITH SW FLOW AT STEERING LEVEL NR 10 TO 15 KTS. PRESENCE OF AN APPROACHING GULF WAVE ALONG WITH A DRY LAYER FROM H7 TO H5 WL ADD POTENTIAL FOR HAIL DEVELOPMENT ALONG WITH STRONG DOWNBURST WINDS NEAR ANY STRONGER STORMS WHICH DEVELOP DURING THE AFTERNOON HEAT. RECENT 2KM HRRR SOLN INDICATES INITIAL CONVECTIVE DEVELOPMENT ALONG A SLOW INLAND MOVING ECSB AROUND MID DAY WITH A LATE COLLISION OF COASTAL BREEZES OVER ECFL NR 5 TO 6 PM LIKELY BRINGING THE GREATEST HAZARD FOR DEVELOPMENT OF STRONG WIND GUSTS ...FREQUENT LIGHTNING AND HAIL. ACTIVITY RESULTING FROM THE LARGE BOUNDARY COLLISION IS SHOWN MOVING BACK TOWARD THE EAST COAST THROUGH DUSK...ESP N OF SEBASTIAN INLET. PERSONS PLANNING OUTDOOR ACTIVITIES SHOULD MONITOR THE WEATHER CONDITIONS AND BE PREPARED TO MOVE INDOORS BEFORE STORMS APPROACH YOUR LOCATION. THE HAZARDOUS OUTLOOK AND FORECAST WL BE UPDATED SHORTLY. && .AVIATION...TEMPO IFR/MVFR CONDS EXPECTED WITH SCT-NMRS SHRA WITH SOME EMBEDDED TS ALONG SEA BREEZE BOUNDARIES THIS AFT AND INTO THE EVE. SFC WND G NR 40KT AND CIGS AOB FL 030 PSBL MNLY INLAND 11/19Z- 12/01Z. && .MARINE...SW WIND FORECAST ACROSS THE WATERS WITH A E/SE COMPONENT NEAR THE IMMEDIATE COAST AS THE SEA BREEZE FORMS THIS AFTN. WINDS THEN BECOME MORE ONSHORE INTO TONIGHT AS FRONT WEAKENS AND HIGH PRESSURE BUILDS TOWARD THE MID ATLANTIC COAST. WINDS WILL REMAIN RELATIVELY LIGHT AROUND 5-10 KTS WITH SEAS 2-4 FEET. MAIN CONCERN WILL BE WITH ANY STORMS THAT EITHER FORM NEAR THE COAST WITH INITIALLY SEA BREEZE FORMATION OR FROM BOUNDARY COLLISIONS LATER IN THE DAY THAT PUSH OFFSHORE...PRODUCING GUSTY WINDS...ESP N OF SEBASTIAN INLET. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ JP/FJ/WU
AREA FORECAST DISCUSSION
NWS WICHITA KS
633 AM CDT SAT APR 11 2015 ...UPDATED FOR 12Z AVIATION DISCUSSION... .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 330 AM CDT SAT APR 11 2015 MID-LEVEL WARM ADVECTION AND A WEAK TRANSIENT SHORTWAVE ALOFT HAS OVERCOME SEEMINGLY MODEST MOISTURE AND RESULTED IN SCATTERED ELEVATED SHOWERS/ISOLATED STORMS FROM NORTH CENTRAL OKLAHOMA ACROSS SOUTHERN KANSAS EARLY THIS MORNING. THE LATEST RUC HAS THE BEST HANDLE ON THIS ACTIVITY WHICH LINGERS IT INTO THE 12Z- 15Z TIME FRAME ACROSS SOUTHEAST KANSAS. STRONGER ELEVATED LOW LEVEL MOISTURE TRANSPORT WILL DEVELOP ACROSS THE AREA TONIGHT AS ANOTHER SHORTWAVE ALOFT MIGRATES EAST ACROSS THE CENTRAL PLAINS. THIS WILL ALLOW DIURNAL CONVECTION ACROSS THE HIGH PLAINS LATER TODAY TO DEVELOP/MOVE EAST ACROSS MUCH OF THE AREA OVERNIGHT. SOME OF THIS ACTIVITY WILL LINGER INTO SUNDAY MORNING ACROSS SOUTHEAST KANSAS...BEFORE RENEWED SURFACE BASED CONVECTION DEVELOPS ALONG A SURFACE COLD FRONT WHICH WILL MOVE INTO CENTRAL KANSAS DURING THE AFTERNOON AS THE ASSOCIATED UPPER TROF MOVES ACROSS THE NORTHERN PLAINS. MODERATE INSTABILITY AND DEEP LAYER SHEAR SHOULD SUPPORT STRONG TO MARGINALLY SEVERE STORMS. WHILE INTENSITY SHOULD DECREASE BY SUNDAY EVENING...COVERAGE WILL LIKELY INCREASE ALONG THE FRONT AS IT MOVES INTO SOUTHEAST KANSAS. COOLER AND DRIER WEATHER IS STILL ON TAP FOR MONDAY. DARMOFAL .LONG TERM...(TUESDAY THROUGH FRIDAY) ISSUED AT 330 AM CDT SAT APR 11 2015 CHANCES FOR PRECIP LOOK TO INCREASE BY MID TO LATE NEXT WEEK WITH THE MEDIUM RANGE MODELS SHOWING AN UPPER TROF MOVING FROM THE ROCKIES AND BECOMING A CLOSED LOW ACROSS THE CENTRAL PLAINS. THERE IS STILL UNCERTAINTY IN THE EVOLUTION AND MOVEMENT/TRACK OF THIS SYSTEM...THOUGH FORECAST CONSENSUS SUPPORTS MODEST CHANCE POPS BY WEDNESDAY NIGHT AND THURSDAY. KED && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 630 AM CDT SAT APR 11 2015 LIGHT SOUTHEAST WINDS THIS MORNING HAVE ALLOWED SMOKE FROM THE FLINT HILLS TO DRIFT INTO THE WICHITA AREA AND REDUCING VISIBILITIES TO MVFR. THIS SHOULD BE SHORT-LIVED AS SPEEDS INCREASE AND VEER TO THE SOUTH CONDITIONS WILL QUICKLY IMPROVE TO VFR. ISOLATED TO WIDELY SCATTERED SHOWERS MAY IMPACT THE AREA THIS AFTERNOON WHILE BETTER CHANCES SHOULD ARRIVE TONIGHT. SOME TRANSIENT MVFR CIGS AND VISIBILITIES WILL BE LIKELY UNDER THE HEAVIEST ACTIVITY. && .FIRE WEATHER... ISSUED AT 330 AM CDT SAT APR 11 2015 PERIODIC CHANCES FOR SHOWERS AND STORMS WILL EXIST ACROSS THE AREA THIS WEEKEND...WITH THE BEST CHANCES TONIGHT ACROSS CENTRAL KANSAS AND SUNDAY NIGHT ACROSS SOUTHEAST AND SOUTH CENTRAL KANSAS. OTHERWISE...INCREASING SOUTH WINDS WILL ELEVATE THE GRASSLAND FIRE DANGER THIS AFTERNOON IN RAIN-FREE AREAS AS WELL AS SUNDAY AFTERNOON. KED && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 71 56 77 53 / 30 40 40 60 HUTCHINSON 71 55 78 49 / 20 50 40 40 NEWTON 70 55 76 50 / 30 50 40 50 ELDORADO 71 56 76 53 / 50 50 40 60 WINFIELD-KWLD 71 56 76 55 / 30 30 40 70 RUSSELL 72 55 78 44 / 30 50 20 20 GREAT BEND 70 55 79 46 / 30 50 20 20 SALINA 72 55 78 46 / 20 60 40 30 MCPHERSON 71 55 77 48 / 20 60 40 40 COFFEYVILLE 72 54 77 57 / 40 30 40 70 CHANUTE 71 54 76 54 / 40 50 50 70 IOLA 71 53 75 54 / 30 60 50 70 PARSONS-KPPF 71 54 76 56 / 40 30 40 70 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1130 AM EDT SAT APR 11 2015 LATEST UPDATE... MARINE .SYNOPSIS... ISSUED AT 330 AM EDT SAT APR 11 2015 HIGH PRESSURE WILL BUILD IN AND BRING FAIR WEATHER THIS WEEKEND. A WEAK COLD FRONT WILL BRING SOME RAIN SHOWERS SUNDAY NIGHT THROUGH MIDDAY MONDAY FOLLOWED BY DRY AND MILD WEATHER FOR TUESDAY THROUGH WEDNESDAY. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 330 AM EDT SAT APR 11 2015 HIGH PRESSURE WILL BUILD INTO THE LOWER GREAT LAKES REGION TODAY AND BRING FAIR WX WITH SEASONABLE TEMPS. MAX TEMPS TODAY WILL RANGE FROM THE MIDDLE 50S TO AROUND 60 DEGREES. FAIR WX WILL CONTINUE TONIGHT THROUGH SUNDAY WITH THE RIDGE STILL IN CONTROL OF THE WX PATTERN. A WEAK COLD FRONT WILL BRING SOME RAIN SHOWERS LATE SUNDAY NIGHT THROUGH AROUND MIDDAY MONDAY. THUNDERSTORMS ARE NOT ANTICIPATED GIVEN LACK OF SFC OR ELEVATED INSTABILITY AND WEAK LIFT WITH THIS FRONT. FAIR WX WILL RETURN BEGINNING MONDAY AFTERNOON. .LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT 330 AM EDT SAT APR 11 2015 FOR THE MOST PART THE FIRST FEW DAYS (TUE/WED) WILL BE QUIET WITH A FAIR AMOUNT OF SUNSHINE AND PLEASANT MID SPRING TEMPERATURES. LATER IN THE WEEK... A SERIES OF PACIFIC SYSTEMS WILL TRY TO DIG SOME SORT UPPER LEVEL TROUGH THAT WILL PROGRESS WEST TO EAST ACROSS THE CONUS. HOW THIS PLAYS OUT IS ANYONE`S GUESS. THE ISSUE IS PHASING OF THE NORTHERN AND SOUTHERN STREAM. FOR NOW IT SORT OF LOOKS LIKE MOST OF THE SIGNIFICANT RAIN/THUNDERSTORMS WILL BE WELL SOUTH OF MICHIGAN INTO FRIDAY (NO PHASING). WE WOULD GET SOME SHOWERS THURSDAY / FRIDAY AS ONE OF THESE UNPHASED WAVES PASS THROUGH THE AREA. ONE THING TO WATCH IS WHAT HAPPENS TO THE SOUTHERN STREAM JET. IT IS CURRENTLY WELL SOUTH OVER THE EASTERN AND CENTRAL PACIFIC....NEAR 20N. IT SEEMS TO WANT TO STAY THERE THROUGH THE EXTENDED PERIOD. TO GET STRONG SYSTEM INTO MICHIGAN WE WOULD NEED A NORTHERN STREAM WAVE TO DIG FAR ENOUGH SOUTH TO TAP THAT ENERGY. CURRENTLY THAT IS DOES NOT SEEM TO WANT TO HAPPEN. SO FOR NOW I WILL FEATURE MOSTLY LOW CHANCE POPS THURSDAY INTO FRIDAY. WE WILL HAVE TO SEE HOW LATER MODEL RUNS PLAY THIS OUT. IF NOTHING ELSE TEMPERATURES WILL BE NEAR NORMAL NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 712 AM EDT SAT APR 11 2015 ONCE THE SUN HAS A CHANCE TO HEAT THE AIR ENOUGH TO START MIXING OF THE BOUNDARY LAYER... THE PATCHY FOG AT OUR EASTERN TAF SITES WILL QUICKLY MIX OUT (BY 14Z). MODEL SOUNDINGS SUGGEST SOME CU AROUND 4000 FT AGL TODAY BUT THE OUTGOING LONG WAVE RADIATION LOOP FROM THE 07Z HRRR DOES NOT SHOW ANY CU OVER OUR CWA TODAY EVEN SO. NO MATTER WHAT SKIES WILL BE CLEAR TONIGHT AND WINDS WILL BE LIGHT FROM THE SOUTH. && .MARINE... ISSUED AT 1128 AM EDT SAT APR 11 2015 WITH HIGH PRESSURE BUILDING IN...WE ARE NOT EXPECTING ANY MAJOR IMPACT TO MARINERS THROUGH TONIGHT. WINDS WILL PICK UP ON SUNDAY AND BOATING CONDITIONS WILL DETERIORATE THROUGH SUNDAY NIGHT. SMALL CRAFT ADVISORIES MAY BE NEEDED. && .HYDROLOGY... ISSUED AT 534 PM EDT THU APR 9 2015 RIVER AND STREAM LEVELS ACROSS CENTRAL LOWER MICHIGAN ARE RISING AFTER THE 2 TO 3.5 INCHES OF RAINFALL EXPERIENCED OVER THE PAST 3 DAYS. THE WHITE RIVER AT WHITEHALL IS IN FLOOD WHILE THE ROGUE RIVER AT ROCKFORD AND THE MUSKEGON RIVER AT CROTON ARE EXPECTED TO SOON REACH FLOOD STAGE. THESE SITES SHOULD BE IN A MINOR FLOOD STATE FOR A DAY OR TWO. MANY OTHER SITES WILL PEAK A LITTLE BELOW FLOOD LEVEL. SITES ACROSS SOUTHERN LOWER MICHIGAN RECEIVED ONLY AN INCH TO AN INCH AND A HALF OF RAIN... AND ARE NOT EXPERIENCING HIGH RIVER LEVELS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ SYNOPSIS...LAURENS SHORT TERM...LAURENS LONG TERM...WDM AVIATION...WDM HYDROLOGY...CAS MARINE...MJS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
713 AM EDT SAT APR 11 2015 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 330 AM EDT SAT APR 11 2015 HIGH PRESSURE WILL BUILD IN AND BRING FAIR WEATHER THIS WEEKEND. A WEAK COLD FRONT WILL BRING SOME RAIN SHOWERS SUNDAY NIGHT THROUGH MIDDAY MONDAY FOLLOWED BY DRY AND MILD WEATHER FOR TUESDAY THROUGH WEDNESDAY. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 330 AM EDT SAT APR 11 2015 HIGH PRESSURE WILL BUILD INTO THE LOWER GREAT LAKES REGION TODAY AND BRING FAIR WX WITH SEASONABLE TEMPS. MAX TEMPS TODAY WILL RANGE FROM THE MIDDLE 50S TO AROUND 60 DEGREES. FAIR WX WILL CONTINUE TONIGHT THROUGH SUNDAY WITH THE RIDGE STILL IN CONTROL OF THE WX PATTERN. A WEAK COLD FRONT WILL BRING SOME RAIN SHOWERS LATE SUNDAY NIGHT THROUGH AROUND MIDDAY MONDAY. THUNDERSTORMS ARE NOT ANTICIPATED GIVEN LACK OF SFC OR ELEVATED INSTABILITY AND WEAK LIFT WITH THIS FRONT. FAIR WX WILL RETURN BEGINNING MONDAY AFTERNOON. .LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT 330 AM EDT SAT APR 11 2015 FOR THE MOST PART THE FIRST FEW DAYS (TUE/WED) WILL BE QUIET WITH A FAIR AMOUNT OF SUNSHINE AND PLEASANT MID SPRING TEMPERATURES. LATER IN THE WEEK... A SERIES OF PACIFIC SYSTEMS WILL TRY TO DIG SOME SORT UPPER LEVEL TROUGH THAT WILL PROGRESS WEST TO EAST ACROSS THE CONUS. HOW THIS PLAYS OUT IS ANYONE`S GUESS. THE ISSUE IS PHASING OF THE NORTHERN AND SOUTHERN STREAM. FOR NOW IT SORT OF LOOKS LIKE MOST OF THE SIGNIFICANT RAIN/THUNDERSTORMS WILL BE WELL SOUTH OF MICHIGAN INTO FRIDAY (NO PHASING). WE WOULD GET SOME SHOWERS THURSDAY / FRIDAY AS ONE OF THESE UNPHASED WAVES PASS THROUGH THE AREA. ONE THING TO WATCH IS WHAT HAPPENS TO THE SOUTHERN STREAM JET. IT IS CURRENTLY WELL SOUTH OVER THE EASTERN AND CENTRAL PACIFIC....NEAR 20N. IT SEEMS TO WANT TO STAY THERE THROUGH THE EXTENDED PERIOD. TO GET STRONG SYSTEM INTO MICHIGAN WE WOULD NEED A NORTHERN STREAM WAVE TO DIG FAR ENOUGH SOUTH TO TAP THAT ENERGY. CURRENTLY THAT IS DOES NOT SEEM TO WANT TO HAPPEN. SO FOR NOW I WILL FEATURE MOSTLY LOW CHANCE POPS THURSDAY INTO FRIDAY. WE WILL HAVE TO SEE HOW LATER MODEL RUNS PLAY THIS OUT. IF NOTHING ELSE TEMPERATURES WILL BE NEAR NORMAL NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 712 AM EDT SAT APR 11 2015 ONCE THE SUN HAS A CHANCE TO HEAT THE AIR ENOUGH TO START MIXING OF THE BOUNDARY LAYER... THE PATCHY FOG AT OUR EASTERN TAF SITES WILL QUICKLY MIX OUT (BY 14Z). MODEL SOUNDINGS SUGGEST SOME CU AROUND 4000 FT AGL TODAY BUT THE OUTGOING LONG WAVE RADIATION LOOP FROM THE 07Z HRRR DOES NOT SHOW ANY CU OVER OUR CWA TODAY EVEN SO. NO MATTER WHAT SKIES WILL BE CLEAR TONIGHT AND WINDS WILL BE LIGHT FROM THE SOUTH. && .MARINE... ISSUED AT 330 AM EDT SAT APR 11 2015 MINIMAL WIND AND WAVE ACTION IS ANTICIPATED TODAY THROUGH TONIGHT. WAVE HEIGHTS WILL INCREASE SOMEWHAT SUNDAY IN RESPONSE TO STRONGER SOUTH WINDS SUNDAY AFTERNOON. && .HYDROLOGY... ISSUED AT 534 PM EDT THU APR 9 2015 RIVER AND STREAM LEVELS ACROSS CENTRAL LOWER MICHIGAN ARE RISING AFTER THE 2 TO 3.5 INCHES OF RAINFALL EXPERIENCED OVER THE PAST 3 DAYS. THE WHITE RIVER AT WHITEHALL IS IN FLOOD WHILE THE ROGUE RIVER AT ROCKFORD AND THE MUSKEGON RIVER AT CROTON ARE EXPECTED TO SOON REACH FLOOD STAGE. THESE SITES SHOULD BE IN A MINOR FLOOD STATE FOR A DAY OR TWO. MANY OTHER SITES WILL PEAK A LITTLE BELOW FLOOD LEVEL. SITES ACROSS SOUTHERN LOWER MICHIGAN RECEIVED ONLY AN INCH TO AN INCH AND A HALF OF RAIN... AND ARE NOT EXPERIENCING HIGH RIVER LEVELS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ SYNOPSIS...LAURENS SHORT TERM...LAURENS LONG TERM...WDM AVIATION...WDM HYDROLOGY...CAS MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1052 AM EDT SAT APR 11 2015 .SYNOPSIS...A SECONDARY COLD FRONT WILL MOVE ACROSS VA AND NC THROUGH THIS EVENING. CANADIAN HIGH PRESSURE WILL FOLLOW AND BUILD ACROSS THE MIDDLE ATLANTIC STATES THROUGH SUN..BEFORE DRIFTING OFFSHORE SUN NIGHT. && .NEAR TERM /THROUGH TODAY/... AS OF 1050 AM SATURDAY... A LEAD COLD FRONT HAD CLEARED ALL BUT BRUNSWICK COUNTY IN NC...WITH A TRAILING 1019 MB SFC RIDGE AXIS CENTERED OVER THE NW NC PIEDMONT. MEANWHILE...A SECONDARY FRONT WAS ANALYZED OVER NORTH-CENTRAL VA...AND THIS FRONT WILL CONTINUE TO MOVE SOUTH AND ACROSS CENTRAL NC WITH LITTLE SENSIBLE WEATHER IMPACT LATE THIS AFTERNOON AND EVENING. IT WILL INSTEAD SIMPLY MARK THE LEADING EDGE OF A PARENT... 1027 MB CANADIAN HIGH PRESSURE CENTERED NEAR THE IL/IN BORDER THAT WILL BUILD ACROSS THE MIDDLE ATLANTIC STATES THROUGH EARLY SUN. THE PREVIOUS FORECAST REPRESENTED THE CLEARING WELL PER RECENT SATELLITE TRENDS AND NEAR TERM MOISTURE PROGS...WHICH SUGGESTS THE BACK EDGE OF THE MAINLY MID-HIGH CLOUDINESS WILL CLEAR THE TRIANGLE BETWEEN NOON AND 1 PM...AND THE COASTAL PLAIN 2-3 HOURS LATER. SOME ADDITIONAL BUT THIN CIRRUS WILL STREAM EAST IN WESTERLY UPPER LEVEL FLOW...FROM THE NORTHERN GULF COAST STATES LATER THIS AFTERNOON. RECENT HRRR AND RAP FORECASTS SUPPORT PREVIOUSLY ADVERTISED HIGHS IN THE 70S. WITH SFC DEWPOINTS FALLING INTO THE 30S COURTESY OF GENERALLY NORTH TO NNW FLOW AROUND THE LEAD RIDGE AXIS OVER THE PIEDMONT...AND EVEN SOME 20S PROBABLE OVER THE NW PIEDMONT...THE AIR WILL FEEL MUCH LESS HUMID THAN RECENT DAYS && .SHORT TERM /TONIGHT THROUGH MONDAY/... AS OF 305 AM SATURDAY... HIGH PRESSURE BUILDS IN OVERNIGHT AND...WHILE THE SURFACE RIDGE AXIS GRADUALLY MOVES EAST...AT LEAST THE WESTERN END OF HIGH PRESSURE CONTINUES OVER CENTRAL NORTH CAROLINA THROUGH SUNDAY NIGHT. PLAN VIEW RELATIVE HUMIDITY FIELDS AND BUFR SOUNDINGS SHOW LIMITED MOISTURE IN OVERALL SUBSIDENCE THROUGH THE OVERNIGHT HOURS OF SUNDAY...WITH K INDICES NEAR ZERO OR BELOW. OVERNIGHT SUNDAY...THE NAM PROVIDES FOR MORE OF A RETURN FLOW WITH FASTER EASTWARD PROGRESS OF LOW PRESSURE OUT OF THE SOUTH PLAINS TOWARD THE LOWER MISSISSIPPI VALLEY...RESULTING IN JUST ENOUGH MOISTURE RETURN FOR THE POSSIBILITY OF LOW CLOUDS TOWARD THE IMMEDIATE TRIAD AND EVEN VERY MINOR QPF. THE GFS...ON THE OTHER HAND...IN MUCH SLOWER IN THE EASTWARD PROGRESS OF LOW PRESSURE...AND DRIER IN THE LOW LEVELS AT LEAST THROUGH 12Z MONDAY. UNCERTAINTY INCREASES SOME SUNDAY NIGHT WITH REGARD TO THE MOISTURE RETURN AND ITS INFLUENCE ON LOW TEMPERATURES THEN...AND FOR THIS FORECAST WILL LEAN TOWARD THE SLOWER SOLUTION DUE TO THE STRENGTH OF THE SURFACE HIGH AND THE SHARPENING RIDGE AXIS THAT EVEN THE NAM FORECASTS OVER THE CAROLINAS SUNDAY NIGHT INTO MONDAY. OVERNIGHT LOWS TONIGHT IN THE LOWER TO MID 40S...LIKELY AROUND 40 KTDF TO KLHZ NORTH...WITH HIGHS SUNDAY IN THE LOWER TO MID 70S...A LITTLE COOLER THAN TODAY OVERALL WITH 1000- 850MB THICKNESSES A FEW METERS LOWER. OVERNIGHT LOWS SUNDAY NIGHT WILL LIKELY BE QUITE VARIABLE THROUGHOUT THE 40S. -DJF MONDAY...A WEAK RIDGE WILL LINGER OVER THE AREA ON MONDAY AS THE HIGH MOVES OFFSHORE. THE RAIN SHOULD STAY LARGELY TO THE SOUTH AND WEST THROUGH THE DAY AS ANOTHER COLD FRONT APPROACHES...ALTHOUGH SOME RAIN MAY MOVE INTO THE WEST LATE IN THE DAY. HIGHS IN THE MID 70S. -RAH && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 305 AM SATURDAY... MONDAY NIGHT THROUGH TUESDAY NIGHT: THE RIDGE WILL BREAK DOWN OVERNIGHT AS THE HIGH MOVES FARTHER AWAY FROM SHORE. A COLD FRONT WILL EXTEND SSW THROUGH THE GREAT LAKES INTO THE MID WEST FROM THE PARENT LOW OVER EAST CENTRAL CANADA AT 00Z TUESDAY. THE FRONT WILL BECOME MORE WEST-EAST ORIENTED OVERNIGHT AS IT DISCONNECTS SOMEWHAT FROM THE PARENT LOW. THE SURFACE FLOW WILL BECOME MORE SOUTHERLY AS A WARM FRONT LIFTS NORTHWARD...ADVECTING WARM MOIST AIR INTO THE REGION. AS FAR AS RAIN CHANCES GO...THE 12Z ECMWF CONTINUES TO BE WETTER THAN THE 00Z GFS SOLUTION OVERNIGHT...HOWEVER BEST CHANCES EARLY ON WILL CONTINUE TO BE ACROSS THE WEST. EXPECT THE BEST CHANCES FOR RAIN ACROSS CENTRAL NC TO BE TUESDAY AND EARLY TUESDAY NIGHT AHEAD OF THE FROPA. A SURFACE HIGH WILL BUILD EAST INTO THE GREAT LAKES BEHIND THE COLD FRONT...WHICH SHOULD PUSH SOUTH INTO CENTRAL NC TUESDAY NIGHT. RAIN SHOULD BE OUT OF THE AREA BY EARLY WEDNESDAY...WITH HIGH PRESSURE RIDGING IN BEHIND IT. HIGHS ON TUESDAY WILL BE IN THE LOW TO MID 70S FROM NORTH TO SOUTH...AND GIVEN THE EXPECTED CLOUD COVER...WILL BE LARGELY DEPENDENT ON THE AMOUNT OF WARM AIR ADVECTED IN BEHIND AND TIMING/PROGRESSION OF THE WARM FRONT. MILD OVERNIGHT LOWS MONDAY NIGHT MAINLY IN THE MID TO UPPER 50S. LOWS TUESDAY NIGHT WILL DEPEND ON THE COLD FRONTAL PASSAGE...BUT FOR NOW EXPECT LOWS IN THE LOW TO MID 50S. WEDNESDAY THROUGH FRIDAY: HIGH PRESSURE WILL BUILD OVERHEAD...AND CONTINUE RIDGING INTO THE AREA AFTER IT MOVES OFFSHORE ON THURSDAY. THE MODELS REALLY START TO DISAGREE WITH RESPECT TO PRECIP DURING THIS TIME...WITH THE ECMWF WETTER THAN THE GFS...THUS CONFIDENCE IS NOT ALL THAT HIGH. FOR NOW...EXPECT WEDNESDAY TO REMAIN DRY WITH GRADUALLY INCREASING RAINFALL CHANCES WEDNESDAY NIGHT THROUGH FRIDAY. HIGHS WILL GENERALLY BE IN THE LOW TO MID 70S WITH LOWS IN THE LOW TO MID 50S. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... AS OF 700 AM SATURDAY... VFR CONDITIONS SHOULD CONTINUE THROUGH THE 12Z VALID TAF PERIOD... AND BEYOND AT LEAST INTO LATE SUNDAY NIGHT. SCATTERED SHOWERS WILL OCCUR IN CENTRAL NORTH CAROLINA TOWARD KFAY AND KCTZ EARLY THIS MORNING. OTHERWISE...BEHIND A COLD FRONT BASICALLY THROUGH CENTRAL NORTH CAROLINA AS OF THIS WRITING...SURFACE WINDS TURN NORTHERLY AND SKIES GRADUALLY CLEAR. MODEL SOUNDINGS SUGGEST A FEW NORTHERLY GUSTS IN THE TEENS KNOTS WITH MIXING TODAY. HIGH CLOUDS WILL GRADUALLY RETREAT TO THE SOUTHEAST DURING THE DAY...WITH MOSTLY CLEAR CONDITIONS OVERNIGHT AND INTO SUNDAY. THE NAM MODEL...WITH A FASTER MOIST RETURN FLOW LATE SUNDAY NIGHT... SUGGESTS THE POTENTIAL FOR LOW CLOUDS NEAR THE TRIAD BY 12Z MONDAY. THE GFS IS VERY DRY STILL IN THE LOW LEVELS AT THAT TIME...SO FOR THIS WRITING CONSIDER A LOW PROBABILITY OF LOW CLOUDS NEAR THE TRIAD EARLY MONDAY MORNING. A MUCH BETTER CHANCE OF SUB-VFR CONDITIONS AND PRECIPITATION OCCURS OVERNIGHT MONDAY INTO TUESDAY. BASED ON THE LATEST GFS MODEL...WIDESPREAD VFR CONDITIONS RETURN TO CENTRAL NORTH CAROLINA BY WEDNESDAY AFTERNOON. && $$ SYNOPSIS...RAH NEAR TERM...RAH SHORT TERM...DJF/RAH LONG TERM...RAH AVIATION...DJF
AREA FORECAST DISCUSSION
NWS BISMARCK ND
938 AM CDT SAT APR 11 2015 .UPDATE... ISSUED AT 922 AM CDT SAT APR 11 2015 SOUTHERLY 925 MB LOW LEVEL WINDS OF 35 KTS FROM RUC MODEL OVER THE JAMES RIVER VALLEY ASSOCIATED WITH THE WEAK SHOWERS EXITING THE JAMES RIVER VALLEY AT THIS TIME. THE WIND SPEEDS AT 925 SUGGEST SURFACE WINDS WINDS WILL PICK UP SOON AS WELL. HOWEVER MODEL SOUNDINGS SHOW THIS LOW LEVEL WIND MAX WILL MOVE EAST THIS AFTERNOON SO DO NOT EXPECT TO REALIZE THESE STRONG WINDS THERE. THERE WILL BE A RELATIVE WIND MAX THERE OF 20 TO 30 MPH. CURRENT STATUS OF RED FLAG WARNING REMAINS THE SAME AND LOOKS OK. UPDATE ISSUED AT 630 AM CDT SAT APR 11 2015 MAINLY CLEAR SKIES ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS MORNING. A WEAK WAVE MOVING ALONG THE NORTH DAKOTA/SOUTH DAKOTA BORDER IS PRODUCING SOME MID LEVEL CLOUDS FROM BISMARCK TO JAMESTOWN AND SOUTH INTO SOUTH DAKOTA. A SPRINKLE OR TWO MAY BE REACHING THE GROUND BUT NOT ENOUGH TO INCLUDE IN THE FORECAST AN HAVE REMOVED THE SLIGHT CHANCE OF SHOWERS THAT WAS IN THE FORECAST THROUGH 7 AM. OTHERWISE NO CHANGES TO THE GOING FORECAST...OR CURRENT FIRE WEATHER HEADLINES. && .SHORT TERM...(TODAY THROUGH MONDAY NIGHT) ISSUED AT 353 AM CDT SAT APR 11 2015 DEVELOPING LOW PRESSURE IN THE LEE OF THE ROCKIES WILL KEEP A SOUTHERLY/SOUTHWESTERLY WIND FLOW ACROSS THE FORECAST AREA TODAY. INCREASING SOUTHWESTERLY FLOW FROM THE SURFACE UP THROUGH H850 IN CENTRAL NORTH DAKOTA...AND UP THROUGH H700 IN WESTERN NORTH DAKOTA. THIS WILL ALLOW MIXING OF LOW LEVELS TO A DRY LAYER ALOFT. INCREASING SOUTH/SOUTHWEST WINDS THIS AFTERNOON TO 15 TO 25 MPH WITH HIGHER GUSTS. THE JAMES VALLEY MAY SEE THE STRONGEST WINDS MID AFTERNOON THROUGH EARLY EVENING...AS THE POCKET OF DRY/WINDY AIR ALOFT SHIFTS TO EASTERN NORTH DAKOTA AHEAD OF A SURFACE TROUGH THAT IS FORECAST TO MOVE INTO WESTERN NORTH DAKOTA LATER IN THE AFTERNOON. THIS WILL RAISE FIRE WEATHER CONCERNS FOR TODAY. SEE THE FIRE WEATHER SECTION BELOW FOR DETAILS. LOOKING AT A WARM DAY TODAY WITH HIGHS IN THE 70S WITH MOSTLY SUNNY SKIES. MEANWHILE AT UPPER LEVELS...A LONGWAVE TROUGH DEVELOPING OVER THE ROCKIES TODAY EXPANDS INTO THE WESTERN PLAINS TONIGHT...AND MOVES EAST ACROSS THE NORTHERN PLAINS SUNDAY AND MONDAY. TONIGHT A SURFACE COLD FRONT MOVES IN BEHIND THE SURFACE TROUGH WITH DECENT COLD ADVECTION. LOOK FOR A CHANCE OF SHOWERS AND POSSIBLY ISOLATED THUNDERSTORMS IN THE VICINITY OF THE FRONT. STRONG NORTHWEST WINDS ARE EXPECTED TO DEVELOP BEHIND THE COLD FRONT...AFTER MIDNIGHT IN THE NORTHWESTERN PART OF THE STATE AND BY DAYBREAK SUNDAY MORNING IN CENTRAL NORTH DAKOTA. BY LATE MORNING/EARLY AFTERNOON NORTHWEST WINDS OF 25 TO 35 MPH ARE EXPECTED WITH GUSTS OVER 40 MPH AT TIMES. A WIND ADVISORY WILL LIKELY BE NEEDED ACROSS ALL OF WESTERN AND CENTRAL NORTH DAKOTA SUNDAY. COOLER WITH HIGHS 50 TO 60. THE UPPER LEVEL TROUGH AND ASSOCIATED ENERGY IMPULSES WILL CREATE ENOUGH INSTABILITY FOR ISOLATED TO SCATTERED SHOWERS. SEE FIRE WEATHER SECTION BELOW FOR FIRE WEATHER CONCERNS ON SUNDAY. CONTINUED WINDY ON MONDAY. THE MAIN UPPER LEVEL TROUGH AXIS SHOULD BE EAST OF THE STATE. THE COMBINATION OF THE VIGOROUS DEPARTING LOW TO OUR EAST/NORTHEAST AND STRONG WARM AND DRY HIGH PRESSURE TO OUR SOUTHWEST WILL PROVIDE A TIGHT PRESSURE GRADIENT ACROSS THE STATE. YET ANOTHER DAY OF POTENTIAL FIRE WEATHER CONCERNS. A BIT WARMER WITH HIGHS IN THE LOWER 60S. .LONG TERM...(TUESDAY THROUGH FRIDAY) ISSUED AT 353 AM CDT SAT APR 11 2015 A PROGRESSIVE SPLIT FLOW PATTERN WILL CONTINUE THROUGH THE EXTENDED PERIOD. ON TUESDAY AN UPPER LEVEL TROUGH MOVES INTO THE NORTHERN ROCKIES WITH SURFACE LOW PRESSURE DEVELOPING IN THE LEE OF THE ROCKIES AND MOVING INTO THE MONDAK REGION BY 00 UTC WEDNESDAY. INCREASING SOUTHERLY FLOW AHEAD OF THE SURFACE LOW WILL BRING BREEZY CONDITIONS TO THE FORECAST AREA TUESDAY WITH TEMPERATURES CLIMBING INTO THE 70S...AND SOME 80 DEGREE READINGS POSSIBLE ACROSS THE SOUTH. WILL NEED TO MONITOR FOR POSSIBLE FIRE WEATHER HIGHLIGHTS AS THE LACK OF LOW LEVEL MOISTURE WILL MEAN ANOTHER DAY WITH LOW RELATIVE HUMIDITIES...ESPECIALLY OVER THE SOUTHWEST. STILL SOME CONCERNS AS TO WHETHER STRONGER WINDS WILL MATCH UP WITH THE LOW AFTERNOON HUMIDITIES. THE SURFACE LOW/COLD FRONT TRACKS ACROSS THE FORECAST AREA TUESDAY NIGHT FOLLOWED BY THE SPLITTING UPPER LEVEL TROUGH WEDNESDAY THROUGH WEDNESDAY NIGHT. BREEZY TO WINDY CONDITIONS TUESDAY NIGHT WITH SOUTHERLY FLOW AHEAD OF THE FRONT AND NORTHWEST WINDS BEHIND THE FRONT. RAIN SHOWER CHANCES ARE EXPECTED TO INCREASE FROM WEST TO EAST LATE TUESDAY NIGHT THROUGH WEDNESDAY JUST AHEAD OF THE UPPER LEVEL TROUGH. PRECIPITATION AMOUNTS WILL BE LIGHT WITH MOST AREAS SEEING THE POSSIBILITY OF UP TO A TENTH OF AN INCH...AND POSSIBLY LOCAL AMOUNTS UP TO A QUARTER INCH. COULD SEE A LINGERING SHOWER EARLY WEDNESDAY EVENING IN THE FAR EASTERN FORECAST AREA...BUT THEN UPPER LEVEL RIDGING QUICKLY BUILDS INTO THE NORTHERN PLAINS BY THURSDAY AND REMAINS THROUGH FRIDAY. THE GFS BRINGS ANOTHER QUICK MOVING COLD FRONT THROUGH THE AREA FRIDAY NIGHT WITH MINIMAL PRECIPITATION CHANCES. THE ECMWF IS SLOWER AND STRONGER WITH THIS SYSTEM BRINGING THE COLD FRONT THROUGH THE AREA ON SATURDAY. PRECIPITATION AMOUNTS WITH THE ECMWF ARE NOT THAT MUCH MORE IMPRESSIVE. EXCEPT FOR THE VERY MILD DAY ON TUESDAY...TEMPERATURES ARE EXPECTED TO REMAIN NEAR TO A LITTLE ABOVE NORMAL THROUGH SATURDAY WITH HIGHS MAINLY IN THE MID 50S TO MID 60S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 630 AM CDT SAT APR 11 2015 VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. SOUTHWEST WINDS BECOMING GUSTY THIS AFTERNOON...GUSTING TO 22-25 KNOTS AT TIMES. A WIND SHIFT TO THE WEST/NORTHWEST SATURDAY NIGHT AS A COLD FRONT ENTERS NORTHWESTERN NORTH DAKOTA AFT 00Z AND MOVES SOUTHEAST ACROSS THE STATE. && .FIRE WEATHER... ISSUED AT 353 AM CDT SAT APR 11 2015 RED FLAG WARNING TODAY. EXPECT THAT RECENT RAIN/SNOW WEDNESDAY EVENING/NIGHT IN THE SOUTHWEST HAS MELTED/EVAPORATED OR FILTERED INTO THE TOPSOIL...AT LEAST KNOWING THAT PARTS OF THOSE SOUTHWESTERN COUNTIES DID NOT HAVE ANY SNOW COVER THE PAST COUPLE OF DAYS. NO REPORTS OF GRASSLANDS BEGINNING TO GREEN UP. RED FLAG CONDITIONS EXPECTED TODAY OVER MOST OF WESTERN AND ALL OF SOUTH CENTRAL NORTH DAKOTA. INCREASING SOUTH/SOUTHWEST WINDS OF 20 TO 25 MPH BY AROUND NOON...AFTERNOON TEMPERATURES IN THE 70S...AND AFTERNOON RELATIVE HUMIDITY VALUES OF 15 TO 20 PERCENT CAN BE EXPECTED TODAY. THIS INCLUDES WILLISTON AND BOWMAN...GARRISON TO JAMESTOWN AND SOUTH. FIRE WEATHER CONCERNS CONTINUE SUNDAY. CONFIDENT ON NORTHWEST WINDS OF 25 TO 35 MPH WITH HIGHER GUSTS. THIS IS FROM A COLD FRONTAL PASSAGE WITH EXPECTED HIGHS IN THE 50S. THERE SHOULD BE SUFFICIENT DRYING AT LOWER LEVELS FOR MINIMUM RELATIVE HUMIDITY VALUES OF AROUND 20 PERCENT SOUTH AND 25 TO 30 PERCENT NORTH. HOWEVER...EXPECTING SOME INCREASED CLOUD COVER WITH ISOLATED TO SCATTERED SHOWERS. MAY NEED A FIRE WEATHER WATCH/RED FLAG WARNING - ESPECIALLY FOR THE SOUTHERN HALF/TWO THIRDS OF THE STATE. CONTINUED WINDY MONDAY WITH HIGHS IN THE LOWER 60S...AND MINIMUM RELATIVE HUMIDITY OF 15 TO 25 PERCENT. WILL NEED TO MONITOR FOR POSSIBLE FIRE WEATHER HEADLINES. && .BIS WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ THIS AFTERNOON TO 7 PM CDT /6 PM MDT/ THIS EVENING FOR NDZ009-010-017>021-025-031>037- 040>048-050-051. && $$ UPDATE...WAA SHORT TERM...JV LONG TERM...TWH AVIATION...JV FIRE WEATHER...JV
AREA FORECAST DISCUSSION
NWS TULSA OK
948 AM CDT SAT APR 11 2015 .DISCUSSION... WARM ADVECTION/ISENTROPIC LIFT OCCURRING WELL ABOVE THE SURFACE ON THE COOL SIDE OF THE FRONT WHICH PASSED THRU A COUPLE DAYS AGO IS PRODUCING HIGH BASED SHOWERS...AND SOME LIGHTNING MAINLY WEST OF THE FORECAST AREA. THE MAJORITY OF THE DATA SUGGESTS PRECIP WILL HAVE A HARD TIME MAKING MUCH EASTWARD PROGRESS INTO OUR AREA...DESPITE WHAT IS CURRENTLY ON RADAR TO OUR WEST. TIME WILL TELL. THE BEST FORCING FOR ASCENT WILL GRADUALLY SHIFT NORTH BY TONIGHT. THE NEXT GOOD CHANCE FOR RAIN/STORMS WILL BE ON SUNDAY WHEN A FRONT DROPS IN FROM THE NORTH...AND MOISTURE INCREASES FROM THE SOUTH IN ASSOCIATION WITH A SOUTHERN STREAM UPPER WAVE. LACY && .PREV DISCUSSION... /ISSUED 551 AM CDT SAT APR 11 2015/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. ISOLATED SHOWERS WILL CONTINUE ACROSS EASTERN OK THIS MORNING BUT WITH MINIMAL ON AVIATION OPS. SOME LOWER VFR CEILINGS ARE POSSIBLE ACROSS NE OK AFTER 06Z SUNDAY WITH ISOLATED STORMS NEAR THE KANSAS BORDER. PREV DISCUSSION... /ISSUED 420 AM CDT SAT APR 11 2015/ DISCUSSION... UNSETTLED WEATHER WILL BE THE RULE OVER THE NEXT WEEK. SHOWERS AND A FEW THUNDERSTORMS ARE TRYING TO MOVE INTO PARTS OF EASTERN OKLAHOMA THIS MORNING BUT ARE HAVING SOME DIFFICULTY OVERCOMING THE DRY LOW LEVEL AIR IN PLACE. OVERALL PRECIPITATION COVERAGE AND INTENSITY IS EXPECTED TO REMAIN RATHER LOW IN OUR AREA TODAY ALTHOUGH THE HRRR DOES INDICATE AT LEAST ISOLATED ACTIVITY CONTINUING MUCH OF THE DAY. EXPECT TO SEE ENOUGH SUN THROUGH THE MID LEVEL CLOUDINESS TO ALLOW AFTERNOON TEMPERATURES TO WARM INTO THE 70S. SHOWER AND THUNDERSTORM CHANCES WILL BE HIGHEST NEAR THE KANSAS BORDER TONIGHT AND WILL BEGIN TO RAMP UP ACROSS THE AREA SUNDAY. THE MOST WIDESPREAD RAINFALL IS STILL EXPECTED SUNDAY NIGHT INTO MONDAY AS A COLD FRONT DROPS SOUTH THROUGH THE AREA. RAIN CHANCES WILL CONTINUE INTO MIDWEEK AS THE UPPER LEVEL STORM SYSTEM WILL LAG BACK OVER THE AREA. ANOTHER UPPER LEVEL SYSTEM WILL MOVE INTO THE AREA THURSDAY WITH MOST MODELS DEVELOPING A CLOSED UPPER LOW IN TEH VICINITY BY LATE WEEK. THIS WILL KEEP RAIN CHANCES GOING THROUGH THE END OF THE WEEK ALONG WITH COOLER TEMPERATURES. STAYED CLOSE TO GUIDANCE TEMPERATURES THE NEXT COUPLE DAYS. && .PRELIMINARY POINT TEMPS/POPS... TUL 74 57 79 61 / 20 20 30 70 FSM 75 54 80 63 / 10 10 40 60 MLC 75 58 77 61 / 10 10 40 70 BVO 73 54 80 58 / 20 20 30 70 FYV 72 53 77 59 / 10 10 30 60 BYV 73 52 76 59 / 10 10 20 60 MKO 74 55 78 61 / 10 10 30 60 MIO 73 52 78 58 / 10 20 30 70 F10 74 58 77 61 / 20 10 30 60 HHW 74 57 76 63 / 10 10 50 80 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ SHORT TERM...30
AREA FORECAST DISCUSSION
NWS TULSA OK
551 AM CDT SAT APR 11 2015 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. ISOLATED SHOWERS WILL CONTINUE ACROSS EASTERN OK THIS MORNING BUT WITH MINIMAL ON AVIATION OPS. SOME LOWER VFR CEILINGS ARE POSSIBLE ACROSS NE OK AFTER 06Z SUNDAY WITH ISOLATED STORMS NEAR THE KANSAS BORDER. && .PREV DISCUSSION... /ISSUED 420 AM CDT SAT APR 11 2015/ DISCUSSION... UNSETTLED WEATHER WILL BE THE RULE OVER THE NEXT WEEK. SHOWERS AND A FEW THUNDERSTORMS ARE TRYING TO MOVE INTO PARTS OF EASTERN OKLAHOMA THIS MORNING BUT ARE HAVING SOME DIFFICULTY OVERCOMING THE DRY LOW LEVEL AIR IN PLACE. OVERALL PRECIPITATION COVERAGE AND INTENSITY IS EXPECTED TO REMAIN RATHER LOW IN OUR AREA TODAY ALTHOUGH THE HRRR DOES INDICATE AT LEAST ISOLATED ACTIVITY CONTINUING MUCH OF THE DAY. EXPECT TO SEE ENOUGH SUN THROUGH THE MID LEVEL CLOUDINESS TO ALLOW AFTERNOON TEMPERATURES TO WARM INTO THE 70S. SHOWER AND THUNDERSTORM CHANCES WILL BE HIGHEST NEAR THE KANSAS BORDER TONIGHT AND WILL BEGIN TO RAMP UP ACROSS THE AREA SUNDAY. THE MOST WIDESPREAD RAINFALL IS STILL EXPECTED SUNDAY NIGHT INTO MONDAY AS A COLD FRONT DROPS SOUTH THROUGH THE AREA. RAIN CHANCES WILL CONTINUE INTO MIDWEEK AS THE UPPER LEVEL STORM SYSTEM WILL LAG BACK OVER THE AREA. ANOTHER UPPER LEVEL SYSTEM WILL MOVE INTO THE AREA THURSDAY WITH MOST MODELS DEVELOPING A CLOSED UPPER LOW IN TEH VICINITY BY LATE WEEK. THIS WILL KEEP RAIN CHANCES GOING THROUGH THE END OF THE WEEK ALONG WITH COOLER TEMPERATURES. STAYED CLOSE TO GUIDANCE TEMPERATURES THE NEXT COUPLE DAYS. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ SHORT TERM...14 LONG TERM....05 AVIATION...14
AREA FORECAST DISCUSSION
NWS MEDFORD OR
858 AM PDT SAT APR 11 2015 .DISCUSSION...THE FORECAST WAS UPDATED TO INCREASE THE PROBABILITY OF LIGHT SHOWERS TODAY AND THIS EVENING...ESPECIALLY NEAR WEST AND NORTHWEST FACING SLOPES IN SOUTHWEST OREGON. THE BACK EDGE OF A SURFACE TROUGH CURRENTLY EXTENDS SOUTHWEST TO NORTHEAST FROM THE VICINITY OF BROOKINGS TO SEXTON SUMMIT, CRATER LAKE, AND CHEMULT. THIS DISTURBANCE HAS GENERALLY PRODUCED ABOUT A TENTH OF AN INCH OF RAIN AT THE COAST, A QUARTER OF AN INCH IN THE COASTAL RANGE OF CURRY COUNTY, AND A TRACE TO 0.05 INCHES IN THE VALLEYS OF SOUTHWEST OREGON AND FAR WESTERN SISKIYOU COUNTY. ADDITIONAL PRECIPITATION THIS MORNING INTO THE EARLY EVENING WILL REMAIN LIGHT AS LIFT IS WEAK AND THE VERTICAL EXTENT OF MOISTURE IS SHALLOW WITH CLOUD TOPS ONLY AROUND 12,000 FEET MSL. THE LOW LEVEL WINDS WILL VEER FROM SOUTHWEST TO NORTHWEST BEHIND THE TROUGH. THUS, THE PROBABILITY OF SHOWERS WILL GRADUALLY DIMINISH AS THE AFTERNOON PROGRESSES...ESPECIALLY WEST OF INTERESTATE 5. EXCEPT, THE EXCEPTION IS THAT THE FACTOR OF INCREASED UPSLOPE FLOW WILL RESULT IN AN INCREASED PROBABILITY OF SHOWERS IN SOUTHERN JACKSON COUNTY. THE LAST SHOWER SHOULD TAPER OFF AROUND 7 OR 8 PM PDT THIS EVENING. BUT, LOW LEVEL STRATOCUMULUS CLOUDS TRANSITIONING TO STRATUS WILL LIKELY LINGER IN WEST SIDE VALLEYS OVERNIGHT AS RIDGING OF HIGH PRESSURE CAUSES THE AIR MASS TO STABILIZE. OTHERWISE, THE SKIES TONIGHT WILL BE MOSTLY CLEAR. SUNDAY LOOKS TO BE MOSTLY SUNNY TO SUNNY AND WARMER ACROSS THE AREA. && .AVIATION...FOR THE 11/12Z TAF CYCLE...A PASSING FRONTAL BOUNDARY WILL BRING RAIN AND SHIFTING WINDS TO THE AREA TODAY. MVFR AND LOCAL IFR WITH INCREASING TERRAIN OBSCURATIONS ARE EXPECTED THROUGH MID MORNING ALONG THE COAST AND IN THE COASTAL RANGE...WHILE MVFR IS EXPECTED TO DEVELOP IN ACROSS THE UMPQUA BASIN WITH TERRAIN OBSCURATIONS SPREADING TO THE CASCADES. SOMEWHAT STEADY VALLEY RAIN AND MOUNTAIN SNOW IS EXPECTED PRIMARILY FROM THE CASCADES WESTWARD THROUGH NOON...WITH SHOWERS CONTINUING THROUGH THE AFTERNOON. CONDITIONS SHOULD IMPROVE THROUGH THE EVENING, BUT SOME RESIDUAL AREAS OF MVFR MAY CONTINUE THROUGH THE REMAINDER OF THE TAF PERIOD. /FB && .MARINE...UPDATED 200 AM PDT, SATURDAY APR 11 2015... A COLD FRONT WILL BRING MODERATE RAIN...INCREASING WINDS...AND BUILDING SEAS AS IT PASSES THROUGH THE WATERS EARLY THIS MORNING. HIGH PRESSURE WILL THEN RETURN WITH BUILDING NORTHWEST SWELL AND ALSO MODERATE NORTH WINDS IN THE OUTER WATERS SOUTH OF CAPE BLANCO. THE NEXT FRONT IS EXPECTED MONDAY AFTERNOON INTO MONDAY NIGHT. TUESDAY AFTERNOON INTO NEXT WEEKEND...NORTH WINDS WILL STRENGTHEN...WITH SMALL CRAFT ADVISORIES LIKELY AND WARNING LEVEL CONDITIONS POSSIBLE SOUTH OF CAPE BLANCO. /FB && .PREV DISCUSSION... /ISSUED 326 AM PDT SAT APR 11 2015/ DISCUSSION...THE LEADING EDGE OF THE FRONT HAS REACHED THE COAST AND WILL CONTINUE TO MOVE INLAND TODAY. THE LATEST HRRR MODEL (WHICH IS A SHORT RANGE MODEL THAT`S UPDATED HOURLY) KEEPS THE ROGUE VALLEY DRY UNTIL MID MORNING. THE BULK OF THE PRECIPITATION WILL BE ALONG THE COAST RANGE AND CASCADES. AMOUNTS WILL BE LESS FOR WESTSIDE VALLEYS WITH AMOUNTS GENERALLY AROUND A TENTH OF AN INCH. SNOW LEVELS ARE EXPECTED TO BE AROUND 5500 FEET, BUT COULD LOWER TO 5000 FEET IN HEAVIER SHOWERS IN THE AFTERNOON. HOWEVER WITH THE BULK OF THE PRECIPITATION COMING DURING THE DAY, ANY SNOW ACCUMULATIONS WILL BE CONFINED TO AROUND CRATER LAKE AND POSSIBLY DIAMOND LAKE WHERE ROADSIDE SLUSH IS POSSIBLE. MEANWHILE GUSTY WINDS ARE EXPECTED, ESPECIALLY EAST OF THE CASCADES, BUT THEY SHOULD REMAIN BELOW ADVISORY CRITERIA. MODELS SHOW 700 MB WINDS BETWEEN 40-45 KTS. THE UPPER TROUGH WILL MOVE EAST OF THE FORECAST AREA TONIGHT AND WEAK RIDGING WILL BUILD IN. ANY SHOWERS WILL END AND DRY CONDITIONS ARE EXPECTED. ALSO THERE MAY BE ENOUGH BREAKS IN THE CLOUD COVER LEADING TO COOLER TEMPERATURES AT NIGHT. WEAK SHORTWAVE RIDGING SETS UP OVER THE AREA SUNDAY BRINGING A RETURN TO DRY AND MILDER CONDITIONS. TEMPERATURES SUNDAY WILL END UP ABOVE NORMAL. THE MODELS SHOW ANOTHER AND STRONGER SHORTWAVE ROUNDING THE BASE OF AN UPPER TROUGH MONDAY AFTERNOON, THUS DRIVING ANOTHER AND STRONGER FRONT INTO THE AREA. RIGHT NOW, THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE TIMING WHICH IS EXPECTED TO REACH THE COAST EARLY MONDAY AFTERNOON, THEN PUSH INLAND MONDAY NIGHT. COLD AIR ALOFT WILL MOVE IN BEHIND THE FRONT MONDAY NIGHT INTO EARLY TUESDAY WITH 500 MB TEMPERATURES BETWEEN -30 AND -33 C MOVING OVERHEAD. SNOW LEVELS WILL ALSO DROP TO AROUND 2500 FEET BY EARLY TUESDAY. THIS ALONG WITH PLENTY OF SHOWERS COULD RESULT IN WINTRY TRAVEL ALONG HIGHWAY 140 NEAR LAKE OF THE WOODS...HIGHWAY 66...HIGHWAYS 62 TOWARDS CRATER LAKE AND HIGHWAY 138 AND 230 NEAR DIAMOND LAKE. THE DETAILS ON THIS ARE NOT CLEAR DUE IN PART TO TIMING AND QPF DIFFERENCES AMONG THE MODELS, SO STAY TUNED FOR THE LATEST UPDATES. TUESDAY IS A TRANSITION DAY WITH THE UPPER TROUGH MOVING EAST AND RIDGING STARTING TO BUILD IN FROM THE SOUTHWEST. ANY SHOWERS SHOULD END IN THE MORNING WITH DRY CONDITIONS FOR THE AFTERNOON. THE LATTER PART OF NEXT WEEK, POSSIBLY INTO NEXT WEEKEND STILL LOOK DRY WITH WARMER TEMPERATURES. -PETRUCELLI && .MFR WATCHES/WARNINGS/ADVISORIES... OR...NONE. CA...NONE. PACIFIC COASTAL WATERS...NONE. $$ DW/SBN/SBN
AREA FORECAST DISCUSSION
NWS MEDFORD OR
326 AM PDT SAT APR 11 2015 .DISCUSSION...THE LEADING EDGE OF THE FRONT HAS REACHED THE COAST AND WILL CONTINUE TO MOVE INLAND TODAY. THE LATEST HRRR MODEL (WHICH IS A SHORT RANGE MODEL THAT`S UPDATED HOURLY) KEEPS THE ROGUE VALLEY DRY UNTIL MID MORNING. THE BULK OF THE PRECIPITATION WILL BE ALONG THE COAST RANGE AND CASCADES. AMOUNTS WILL BE LESS FOR WESTSIDE VALLEYS WITH AMOUNTS GENERALLY AROUND A TENTH OF AN INCH. SNOW LEVELS ARE EXPECTED TO BE AROUND 5500 FEET, BUT COULD LOWER TO 5000 FEET IN HEAVIER SHOWERS IN THE AFTERNOON. HOWEVER WITH THE BULK OF THE PRECIPITATION COMING DURING THE DAY, ANY SNOW ACCUMULATIONS WILL BE CONFINED TO AROUND CRATER LAKE AND POSSIBLY DIAMOND LAKE WHERE ROADSIDE SLUSH IS POSSIBLE. MEANWHILE GUSTY WINDS ARE EXPECTED, ESPECIALLY EAST OF THE CASCADES, BUT THEY SHOULD REMAIN BELOW ADVISORY CRITERIA. MODELS SHOW 700 MB WINDS BETWEEN 40-45 KTS. THE UPPER TROUGH WILL MOVE EAST OF THE FORECAST AREA TONIGHT AND WEAK RIDGING WILL BUILD IN. ANY SHOWERS WILL END AND DRY CONDITIONS ARE EXPECTED. ALSO THERE MAY BE ENOUGH BREAKS IN THE CLOUD COVER LEADING TO COOLER TEMPERATURES AT NIGHT. WEAK SHORTWAVE RIDGING SETS UP OVER THE AREA SUNDAY BRINGING A RETURN TO DRY AND MILDER CONDITIONS. TEMPERATURES SUNDAY WILL END UP ABOVE NORMAL. THE MODELS SHOW ANOTHER AND STRONGER SHORTWAVE ROUNDING THE BASE OF AN UPPER TROUGH MONDAY AFTERNOON, THUS DRIVING ANOTHER AND STRONGER FRONT INTO THE AREA. RIGHT NOW, THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE TIMING WHICH IS EXPECTED TO REACH THE COAST EARLY MONDAY AFTERNOON, THEN PUSH INLAND MONDAY NIGHT. COLD AIR ALOFT WILL MOVE IN BEHIND THE FRONT MONDAY NIGHT INTO EARLY TUESDAY WITH 500 MB TEMPERATURES BETWEEN -30 AND -33 C MOVING OVERHEAD. SNOW LEVELS WILL ALSO DROP TO AROUND 2500 FEET BY EARLY TUESDAY. THIS ALONG WITH PLENTY OF SHOWERS COULD RESULT IN WINTRY TRAVEL ALONG HIGHWAY 140 NEAR LAKE OF THE WOODS...HIGHWAY 66...HIGHWAYS 62 TOWARDS CRATER LAKE AND HIGHWAY 138 AND 230 NEAR DIAMOND LAKE. THE DETAILS ON THIS ARE NOT CLEAR DUE IN PART TO TIMING AND QPF DIFFERENCES AMONG THE MODELS, SO STAY TUNED FOR THE LATEST UPDATES. TUESDAY IS A TRANSITION DAY WITH THE UPPER TROUGH MOVING EAST AND RIDGING STARTING TO BUILD IN FROM THE SOUTHWEST. ANY SHOWERS SHOULD END IN THE MORNING WITH DRY CONDITIONS FOR THE AFTERNOON. THE LATTER PART OF NEXT WEEK, POSSIBLY INTO NEXT WEEKEND STILL LOOK DRY WITH WARMER TEMPERATURES. -PETRUCELLI && .AVIATION...A PASSING FRONTAL BOUNDARY WILL BRING SHIFTING WINDS TO THE AREA TODAY. MVFR AND LOCAL IFR WITH INCREASING TERRAIN OBSCURATIONS ARE EXPECTED THIS MORNING ALONG THE COAST AND IN THE COASTAL RANGE...WHILE MVFR IS EXPECTED TO DEVELOP IN ACROSS THE UMPQUA BASIN WITH TERRAIN OBSCURATIONS SPREADING TO THE CASCADES. VFR CONDITIONS SHOULD BE THE PREDOMINATE CONDITION THIS AFTERNOON AND EVENING, HOWEVER BRIEF MVFR CIGS ARE POSSIBLE IN SHOWERS WITH MOUNTAINS OBSCURED. GUSTY WINDS ARE EXPECTED CAUSING TURBULENCE ALONG AND THE LEE SIDE OF THE CASCADES. -PETRUCELLI && .MARINE...UPDATED 200 AM PDT, SATURDAY APR 11 2015... A COLD FRONT WILL BRING MODERATE RAIN...INCREASING WINDS...AND BUILDING SEAS AS IT PASSES THROUGH THE WATERS EARLY THIS MORNING. HIGH PRESSURE WILL THEN RETURN WITH BUILDING NORTHWEST SWELL AND ALSO MODERATE NORTH WINDS IN THE OUTER WATERS SOUTH OF CAPE BLANCO. THE NEXT FRONT IS EXPECTED MONDAY AFTERNOON INTO MONDAY NIGHT. TUESDAY AFTERNOON INTO NEXT WEEKEND...NORTH WINDS WILL STRENGTHEN...WITH SMALL CRAFT ADVISORIES LIKELY AND WARNING LEVEL CONDITIONS POSSIBLE SOUTH OF CAPE BLANCO. FB && .MFR WATCHES/WARNINGS/ADVISORIES... OR...NONE. CA...NONE. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT EARLY THIS MORNING FOR PZZ350-356-370-376. SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT EARLY THIS MORNING FOR PZZ350-370. $$ MAP/MAP/MAP
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1057 AM CDT SAT APR 11 2015 .UPDATE... MID TO UPPER LEVEL MOISTURE CONTINUES TO PUSH ACROSS THE AREA FROM THE EASTERN PACIFIC. LATEST RAP40 ANALYSIS SHOWS SEVERAL SHORT WAVES ACROSS NORTHWEST AND NORTH CENTRAL MEXICO AS THEY MOVE TO THE NORTHEAST. SPC MESOANALYSIS PAGE SHOWS RICH TROPICAL AIRMASS PUSHING FROM THE SOUTH AT LOW LEVELS AND THE 12Z KDRT SOUNDING BACK THIS UP. AS OF NOW...AREA RADARS ARE SHOWING SOME LIGHT ECHOES ACROSS 2/3 OF THE REGION WITH ISOLATED MODEATE SHOWERS ACROSS THE SOUTHERN COUNTIES. THIS ACTIVITY IS EXPECTED TO INCREASE AS THE DAY PROGRESSES AND THE SHORT WAVE DISTURBANCE OUT WEST NEARS LATER THIS AFTERNOON AND EVENING. HIRES MODELS ARE ALL OVER THE PLACE WITH THE FIRST WAVE BUT THEY ARE MORE IN LINE WITH A SECOND DISTURBANCE TO COME ACROSS THE AREA SUNDAY AFTERNOON AND EVENING. SPC DAY ONE OUTLOOK KEEPS THE SOUTHWEST COUNTIES UNDER A MARGINAL RISK FOR SEVERE STORMS MAINLY THIS AFTERNOON AND EVENING. THEREFORE...CAN`T RULE OUT FEW STRONG TO SEVERE STORMS OUT WEST MAINLY ALONG AND SOUTH OF HIGHWAY 57. MAIN HAZARDS FOR THIS PERIOD WILL BE DAMAGING WIND GUSTS AND LARGE HAIL. FOR SUNDAY/SPC DAY 2 OUTLOOK...A MARGINAL RISK FOR SEVERE STORMS EXISTS OVER MUCH OF THE AREA WITH ISOLATED STRONG TO SEVERE STORMS POSSIBLE AND CAPABLE OF PRODUCING DAMAGING WIND GUSTS AND LARGE HAIL. ALSO...ANOTHER AREA OF CONCERN FOR SUNDAY AFTERNOON/ EVENING INTO THE OVERNIGHT HOURS IS LOCALLY HEAVY RAINS. GFS/NAM/EWC STORM RAINFALL TOTALS FOR THE NEXT 48 HOURS RANGE FROM 1 TO 2 INCHES ALONG AND EAST OF I-35 WITH 2 TO 3 INCHES ACROSS THE FAR SOUTHEAST COUNTIES. STAY TUNED AND CLOSELY MONITOR THE WEATHER CONDITIONS THROUGH THE WEEKEND FOR UPDATED INFORMATION AS THIS WET PATTERN AFFECT THE AREA. && .PREV DISCUSSION... /ISSUED 646 AM CDT SAT APR 11 2015/ AVIATION... -SHRA ARE DEVELOPING ACROSS SOUTH CENTRAL TEXAS EARLY THIS MORNING. SHRA WILL SLOWLY BECOME MORE NUMEROUS TODAY AND REMAIN SCT TONIGHT INTO EARLY SUNDAY MORNING. ISOLD/SCT TSRA WILL DEVELOP MIDDAY AND PERSIST THROUGH TONIGHT. HAVE GONE VCSH/-SHRA AT THE TAF SITES...EXCEPT VCTS THIS AFTERNOON INTO EARLY EVENING. IFR CIGS WILL PREVAIL WITH PATCHY LIFR CIGS AND IFR/MVFR VSBYS THIS MORNING. CIGS WILL STRUGGLE TO RISE TO MVFR THIS AFTERNOON AS SHRA BECOME MORE NUMEROUS. CIGS FALL BACK TO IFR WITH PATCHY LIFR CIGS AND IFR/MVFR VSBYS TONIGHT INTO SUNDAY MORNING. NELY WINDS LESS THAN 10 KTS MOST AREAS WILL SLOWLY TURN SELY THIS AFTERNOON INTO EVENING. EXCEPT SELY WINDS 10 KTS OR LESS WILL PREVAIL ALONG THE RIO GRANDE AND EDWARDS PLATEAU. PREV DISCUSSION... /ISSUED 341 AM CDT SAT APR 11 2015/ SHORT TERM (TODAY THROUGH SUNDAY NIGHT)...GOOD CHANCES FOR RAINFALL THE NEXT 48 HOURS ACROSS SOUTH-CENTRAL TEXAS. A MOIST MID AND UPPER LEVEL TAP FROM THE PACIFIC WILL CONTINUE OVERHEAD. THE LOWEST LEVELS ARE CURRENTLY RELATIVELY DRY BEHIND YESTERDAYS COLD FRONT...ESPECIALLY ACROSS NORTHERN AREAS WHERE DEW POINTS ARE IN THE LOW 50S. THIS WILL MODIFY AS A WARM FRONT LIFTS BACK NORTH THROUGH THE AREA DURING THE MORNING...AND LOW LEVEL H85 THETA-E ADVECTION SETS UP OVER THE REGION THROUGH TOMORROW. PWAT VALUES ARE FORECAST TO INCREASE TO AROUND 1.5-1.7 INCHES BY THIS AFTERNOON AND CLOSER TO 1.8-1.9 INCHES EAST OF I-35 SUNDAY AND SUNDAY NIGHT...WELL ABOVE 2 STANDARD DEVIATIONS OF THE MEAN FOR THIS TIME OF YEAR. THE WARM FRONT LIFTING BACK THROUGH THE AREA WILL SERVE AS FOCUS FOR FORCING TODAY. HAVE FOLLOWED CLOSER TO THE HRRR AND SREF THROUGH THE NEXT 12 HOURS...WHICH SEEM TO BE RELATIVELY BETTER WITH ONGOING CONVECTION SOUTH AND WEST OF THE CWA. WITH NO CAP IN PLACE...SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP MID MORNING ACROSS THE WESTERN AND SOUTHERN CWA AND EXPANDING NORTHEAST THROUGH THE AFTERNOON. AN UPPER LEVEL LOW OFF THE SOUTHERN CALIFORNIA COAST WILL MOVE EAST THROUGH BAJA CALIFORNIA TONIGHT...AND THROUGH NORTHERN MEXICO AND INTO FAR WEST TEXAS SUNDAY AND SUNDAY NIGHT. TIMING OF MID LEVEL DISTURBANCES IN THE SOUTHWEST FLOW ALOFT IS DIFFICULT. GENERALLY ECMWF AND GFS ARE SHOWING TONIGHT THROUGH SUNDAY MORNING FORCING INCREASING OUT OF SOUTH AND DEEP SOUTH TEXAS THROUGH EASTERN PORTIONS OF THE EWX CWA...AND THEN A SECOND DISTURBANCE LATE SUNDAY NIGHT INTO MONDAY MORNING COMING OUT OF MEXICO WEST TO EAST ACROSS THE EWX CWA. THE UPPER LEVEL PATTERN BECOMES BROADLY DIFFLUENT OVER THE REGION SUNDAY AND SUNDAY NIGHT BETWEEN AFOREMENTIONED UPPER LEVEL LOW TO THE WEST-NORTHWEST AND SOUTHERN STREAM SUBTROPICAL JET STREAK ACROSS DEEP SOUTH TEXAS AND MEXICO. THIS ALL INDICATES HIGH CHANCES FOR MULTIPLE ROUNDS OF PRECIP THROUGH EARLY MONDAY MORNING. CAN NOT RULE OUT A FEW STRONGER STORMS...MAINLY SOUTHERN AND WESTERN AREAS WHERE DEEP LAYER SHEAR IS BETTER...BUT OVERALL THE MOIST NATURE OF THE COLUMN LOOKS MORE OF INDICATIVE OF LOCALLY HEAVY RAIN POTENTIAL. RAINFALL TOTALS THROUGH MONDAY MORNING LOOK TO AVERAGE AROUND 1/2 TO 1 INCH ALONG THE RIO GRANDE...1 TO 2 INCHES ACROSS THE HILL COUNTRY AND I-35 CORRIDOR...AND 2 TO 3 INCHES EAST OF I-35. A FEW POCKETS OF HEAVIER RAINFALL TOTALS ARE POSSIBLE...ESPECIALLY SOUTHERN AND EASTERN AREAS. LONG TERM (MONDAY THROUGH FRIDAY)...DRIER AIR DOES WORK INTO THE RIO GRANDE AND HILL COUNTRY ON MONDAY WITH DECREASING POPS WEST TO EAST. THE UPPER LEVEL LOW EVENTUALLY OPENS AND SHEARS NORTHEAST MONDAY NIGHT AND TUESDAY...AND A WEAK COLD FRONT ENTERS SOUTH- CENTRAL TEXAS TUESDAY. SHOULD SEE ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS TUESDAY WITH DEEP MOISTURE STILL POOLED ALONG AND EAST OF THE I-35 CORRIDOR. EVENTUALLY THE UPPER LEVEL TROUGH DEEPENS THROUGH THE ROCKIES AND INTO THE PLAINS WEDNESDAY INTO THURSDAY...SENDING A STRONGER COLD FRONT INTO THE AREA ON THURSDAY OR THURSDAY NIGHT. WITH A STRONG SUB-TROPICAL TAP FROM THE PACIFIC CONTINUING IT APPEARS ANOTHER GOOD CHANCE FOR PRECIP WILL OCCUR DURING THIS TIME. DRIER AND MORE SEASONAL CONDITIONS FRIDAY INTO SATURDAY. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 74 66 78 65 82 / 60 70 70 90 40 AUSTIN BERGSTROM INTL AIRPORT 74 66 77 65 81 / 60 70 70 90 40 NEW BRAUNFELS MUNI AIRPORT 76 66 78 64 84 / 60 70 70 90 40 BURNET MUNI AIRPORT 72 64 77 63 81 / 60 60 60 80 40 DEL RIO INTL AIRPORT 77 66 80 63 85 / 60 40 50 70 10 GEORGETOWN MUNI AIRPORT 73 65 76 65 81 / 50 70 70 80 40 HONDO MUNI AIRPORT 75 66 79 64 84 / 60 60 60 90 20 SAN MARCOS MUNI AIRPORT 75 66 77 65 82 / 60 70 70 90 40 LA GRANGE - FAYETTE REGIONAL 76 68 77 68 81 / 60 60 70 80 50 SAN ANTONIO INTL AIRPORT 74 67 79 66 83 / 60 70 60 90 30 STINSON MUNI AIRPORT 75 68 79 66 84 / 60 70 60 90 30 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...29 SYNOPTIC/GRIDS...17 PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
646 AM CDT SAT APR 11 2015 .AVIATION... -SHRA ARE DEVELOPING ACROSS SOUTH CENTRAL TEXAS EARLY THIS MORNING. SHRA WILL SLOWLY BECOME MORE NUMEROUS TODAY AND REMAIN SCT TONIGHT INTO EARLY SUNDAY MORNING. ISOLD/SCT TSRA WILL DEVELOP MIDDAY AND PERSIST THROUGH TONIGHT. HAVE GONE VCSH/-SHRA AT THE TAF SITES...EXCEPT VCTS THIS AFTERNOON INTO EARLY EVENING. IFR CIGS WILL PREVAIL WITH PATCHY LIFR CIGS AND IFR/MVFR VSBYS THIS MORNING. CIGS WILL STRUGGLE TO RISE TO MVFR THIS AFTERNOON AS SHRA BECOME MORE NUMEROUS. CIGS FALL BACK TO IFR WITH PATCHY LIFR CIGS AND IFR/MVFR VSBYS TONIGHT INTO SUNDAY MORNING. NELY WINDS LESS THAN 10 KTS MOST AREAS WILL SLOWLY TURN SELY THIS AFTERNOON INTO EVENING. EXCEPT SELY WINDS 10 KTS OR LESS WILL PREVAIL ALONG THE RIO GRANDE AND EDWARDS PLATEAU. && .PREV DISCUSSION... /ISSUED 341 AM CDT SAT APR 11 2015/ SHORT TERM (TODAY THROUGH SUNDAY NIGHT)...GOOD CHANCES FOR RAINFALL THE NEXT 48 HOURS ACROSS SOUTH-CENTRAL TEXAS. A MOIST MID AND UPPER LEVEL TAP FROM THE PACIFIC WILL CONTINUE OVERHEAD. THE LOWEST LEVELS ARE CURRENTLY RELATIVELY DRY BEHIND YESTERDAYS COLD FRONT...ESPECIALLY ACROSS NORTHERN AREAS WHERE DEW POINTS ARE IN THE LOW 50S. THIS WILL MODIFY AS A WARM FRONT LIFTS BACK NORTH THROUGH THE AREA DURING THE MORNING...AND LOW LEVEL H85 THETA-E ADVECTION SETS UP OVER THE REGION THROUGH TOMORROW. PWAT VALUES ARE FORECAST TO INCREASE TO AROUND 1.5-1.7 INCHES BY THIS AFTERNOON AND CLOSER TO 1.8-1.9 INCHES EAST OF I-35 SUNDAY AND SUNDAY NIGHT...WELL ABOVE 2 STANDARD DEVIATIONS OF THE MEAN FOR THIS TIME OF YEAR. THE WARM FRONT LIFTING BACK THROUGH THE AREA WILL SERVE AS FOCUS FOR FORCING TODAY. HAVE FOLLOWED CLOSER TO THE HRRR AND SREF THROUGH THE NEXT 12 HOURS...WHICH SEEM TO BE RELATIVELY BETTER WITH ONGOING CONVECTION SOUTH AND WEST OF THE CWA. WITH NO CAP IN PLACE...SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP MID MORNING ACROSS THE WESTERN AND SOUTHERN CWA AND EXPANDING NORTHEAST THROUGH THE AFTERNOON. AN UPPER LEVEL LOW OFF THE SOUTHERN CALIFORNIA COAST WILL MOVE EAST THROUGH BAJA CALIFORNIA TONIGHT...AND THROUGH NORTHERN MEXICO AND INTO FAR WEST TEXAS SUNDAY AND SUNDAY NIGHT. TIMING OF MID LEVEL DISTURBANCES IN THE SOUTHWEST FLOW ALOFT IS DIFFICULT. GENERALLY ECMWF AND GFS ARE SHOWING TONIGHT THROUGH SUNDAY MORNING FORCING INCREASING OUT OF SOUTH AND DEEP SOUTH TEXAS THROUGH EASTERN PORTIONS OF THE EWX CWA...AND THEN A SECOND DISTURBANCE LATE SUNDAY NIGHT INTO MONDAY MORNING COMING OUT OF MEXICO WEST TO EAST ACROSS THE EWX CWA. THE UPPER LEVEL PATTERN BECOMES BROADLY DIFFLUENT OVER THE REGION SUNDAY AND SUNDAY NIGHT BETWEEN AFOREMENTIONED UPPER LEVEL LOW TO THE WEST-NORTHWEST AND SOUTHERN STREAM SUBTROPICAL JET STREAK ACROSS DEEP SOUTH TEXAS AND MEXICO. THIS ALL INDICATES HIGH CHANCES FOR MULTIPLE ROUNDS OF PRECIP THROUGH EARLY MONDAY MORNING. CAN NOT RULE OUT A FEW STRONGER STORMS...MAINLY SOUTHERN AND WESTERN AREAS WHERE DEEP LAYER SHEAR IS BETTER...BUT OVERALL THE MOIST NATURE OF THE COLUMN LOOKS MORE OF INDICATIVE OF LOCALLY HEAVY RAIN POTENTIAL. RAINFALL TOTALS THROUGH MONDAY MORNING LOOK TO AVERAGE AROUND 1/2 TO 1 INCH ALONG THE RIO GRANDE...1 TO 2 INCHES ACROSS THE HILL COUNTRY AND I-35 CORRIDOR...AND 2 TO 3 INCHES EAST OF I-35. A FEW POCKETS OF HEAVIER RAINFALL TOTALS ARE POSSIBLE...ESPECIALLY SOUTHERN AND EASTERN AREAS. LONG TERM (MONDAY THROUGH FRIDAY)...DRIER AIR DOES WORK INTO THE RIO GRANDE AND HILL COUNTRY ON MONDAY WITH DECREASING POPS WEST TO EAST. THE UPPER LEVEL LOW EVENTUALLY OPENS AND SHEARS NORTHEAST MONDAY NIGHT AND TUESDAY...AND A WEAK COLD FRONT ENTERS SOUTH- CENTRAL TEXAS TUESDAY. SHOULD SEE ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS TUESDAY WITH DEEP MOISTURE STILL POOLED ALONG AND EAST OF THE I-35 CORRIDOR. EVENTUALLY THE UPPER LEVEL TROUGH DEEPENS THROUGH THE ROCKIES AND INTO THE PLAINS WEDNESDAY INTO THURSDAY...SENDING A STRONGER COLD FRONT INTO THE AREA ON THURSDAY OR THURSDAY NIGHT. WITH A STRONG SUB-TROPICAL TAP FROM THE PACIFIC CONTINUING IT APPEARS ANOTHER GOOD CHANCE FOR PRECIP WILL OCCUR DURING THIS TIME. DRIER AND MORE SEASONAL CONDITIONS FRIDAY INTO SATURDAY. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 74 66 78 65 82 / 60 70 70 90 40 AUSTIN BERGSTROM INTL AIRPORT 74 66 77 65 81 / 60 70 70 90 40 NEW BRAUNFELS MUNI AIRPORT 76 66 78 64 84 / 60 70 70 90 40 BURNET MUNI AIRPORT 72 64 77 63 81 / 60 60 60 80 40 DEL RIO INTL AIRPORT 77 66 80 63 85 / 60 40 50 70 10 GEORGETOWN MUNI AIRPORT 73 65 76 65 81 / 50 70 70 80 40 HONDO MUNI AIRPORT 75 66 79 64 84 / 60 60 60 90 20 SAN MARCOS MUNI AIRPORT 75 66 77 65 82 / 60 70 70 90 40 LA GRANGE - FAYETTE REGIONAL 76 68 77 68 81 / 60 60 70 80 50 SAN ANTONIO INTL AIRPORT 74 67 79 66 83 / 60 70 60 90 30 STINSON MUNI AIRPORT 75 68 79 66 84 / 60 70 60 90 30 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...04 SYNOPTIC/GRIDS...76
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
327 PM EDT SAT APR 11 2015 .DISCUSSION... THIS EVENING INTO SUNDAY...AN INTERMEDIATE SPECIAL SOUNDING AT XMR YIELDS A PWAT ~1.52 INCHES ALONG WITH SW FLOW AT STEERING LEVEL NR 10 TO 15 KTS. ADDITIONALLY...TEMPS AT H5 HAVE COOLED TO -10C. THE APCHG GULF WAVE WL HELP ADD POTENTIAL FOR SOME ADT`L STORMS ALONG WITH MID TO LATE AFTERNOON BOUNDARY COLLISIONS. THE MOST RECENT 2KM HRRR SOLN INDICATES ACTIVE COASTAL BREEZES FOLDING TOGETHER LATE THIS AFTN LIKELY BRINGING THE GREATEST HAZARD FOR DEVELOPMENT OF STRONG WIND GUSTS...FREQUENT LIGHTNING AND HAIL. ACTIVITY RESULTING FROM THE LARGER COLLISION IS SHOWN MOVING BACK TOWARD THE EAST COAST THROUGH DUSK...ESP N OF SEBASTIAN INLET. SHOWER AND STROSM SHOULD WIND DOWN BY 11 PM...OR MOVE OVER THE ATLANTIC WATERS...LEAVING LIGHT TO CALM WINDS AND LIKELY DEVELOPMENT OF PATCHY FOG EARLY SUNDAY INLAND SPOTS. SUNDAT... THE FRONTAL BOUNDARY NORTH OF THE AREA WILL STAY AS SUCH WITH THE TAIL END OF FEATURE REMAINING NORTH OF THE COASTAL WATERS. HIGH PRESSURE WILL BRIDGE NORTH OF THE BOUNDARY AND ONSHORE WINDS WILL DEVELOP. SUFFICIENT MOISTURE AND LOCAL CONVERGENCE OF WINDS WILL SET UP OVER THE INTERIOR AS EAST COAST SEA BREEZE PUSHES INLAND FASTER THAN PREVIOUS DAYS. WITH WEAK STEERING FLOW WILL KEEP HIGHEST PRECIP CHC ALONG WITH EMBEDDED STORMS OVER THE NORTH INTERIOR...50 TO 55 PERCENT. QUICKER INLAND PUSH OF SEA BREEZE SHOULD BRING THE LOWEST POPS TO THE COAST SOUTH OF CANAVERAL...30 PERCENT. SUN NIGHT...LITTLE CHANGE FROM PREVIOUS MODEL RUNS. TAIL END OF FRONTAL IS STILL PROGGED TO HANG UP NORTH OF THE COASTAL WATERS WHILE HIGH PRESSURE TO THE NORTH BRIDGES THE BOUNDARY AND DEVELOPS AN ONSHORE GRADIENT WIND FLOW. PRECIPITABLE WATER SHOULD RISE FROM PREVIOUS DAYS...REACHING 1.5 INCHES OR A LITTLE HIGHER AREAWIDE. MON-NEXT SAT...HIGH PRESSURE WILL SHIFT OFFSHORE EARLY IN THE WEEK WITH A RIDGE AXIS SETTLING INTO CENTRAL FLORIDA BY TUE. A WEAK FRONTAL BOUNDARY PUSHING OFFSHORE TO OUR NORTH AT MID WEEK WILL NOT LIKELY HAVE MUCH IMPACT. THE MODELS HAVE NOT SHOWN RUN TO RUN CONSISTENCY WITH A STRONGER FRONT THAT MAY APPROACH NEXT WEEKEND. SO THE BOTTOM LINE IS THAT MOISTURE LEVELS WILL LIKELY REMAIN ABOVE NORMAL THROUGH THE PERIOD. FORECAST SOUNDINGS SHOW NO SUPPRESSION...SO EXPECT THAT WE WILL HAVE SCATTERED SEA BREEZE GENERATED SHOWERS/STORMS EACH DAY. DISTRIBUTION OF COVERAGE WILL DEPEND ON STEERING FLOW...WHICH IS PROGGED TO BE WEAKLY WEST TO EAST EARLY IN THE WEEK AND THEN GET STRONGER THROUGH LATE WEEK. OCCASIONAL EMBEDDED DISTURBANCES ALOFT SHOULD ADD ADDITIONAL LIFT...AND MAY ACT TO KEEP CONVECTION GOING WELL INTO SOME EVENINGS. WHILE IT IS TOO EARLY TO CHRISTEN THE ONSET OF THE WET SEASON...IT APPEARS MOST OF THE AREA WILL START TO SEE RAINFALL DEFICITS DIMINISH SOME. && .AVIATION... TEMPO IFR/MVFR CONDS EXPECTED WITH SCT SHRA WITH SOME EMBEDDED TS ALONG SEA BREEZE BOUNDARIES FROM MID AFT AND INTO THE EVE. ISOLD SFC WND G 35 TO 40KT AND CIGS AOB FL 035 PSBL MNLY INLAND THROUGH 12/01Z. SOME PATCHY MIFG WL BE POSSIBLE INTERIOR SITES FM 12/07Z-12/12Z. && .MARINE... TONIGHT AND SUNDAY...SW WIND FORECAST ACROSS THE WATERS WITH A E/SE COMPONENT NEAR THE IMMEDIATE COAST. WINDS THEN BECOME MORE ONSHORE INTO SUNDAY AS FRONT WEAKENS AND HIGH PRESSURE BUILDS TOWARD THE MID ATLANTIC COAST. WINDS WILL REMAIN RELATIVELY LIGHT AROUND 5-10 KTS WITH SEAS 2-4 FEET. MAIN CONCERN WILL BE WITH ANY STORMS THAT EITHER FORM NEAR THE COAST WITH INITIALLY SEA BREEZE FORMATION OR FROM BOUNDARY COLLISIONS LATER IN THE DAY THAT PUSH OFFSHORE...PRODUCING GUSTY WINDS...ESP N OF SEBASTIAN INLET. MON-WED...HIGH PRESSURE WILL PUSH SEAWARD AND WINDS WILL VEER TO SOUTHEAST MON THEN SOUTH/SOUTHEAST ON TUE. EXPECTED SPEEDS ARE 10-15 KNOTS. ON WED THE TAIL END OF ANOTHER WEAK FRONT WILL CAUSE THE PRESSURE GRADIENT TO EASE AND WINDS DIMINISH. A CHANCE FOR STORMS MOVING OFFSHORE IS INDICATED EACH AFTERNOON/EVENING... ESPECIALLY FROM CANAVERAL NORTHWARD. && .PRELIMINARY POINT TEMPS/POPS... DAB 67 83 70 82 / 30 50 30 50 MCO 67 88 69 86 / 30 50 30 50 MLB 69 84 71 83 / 40 40 30 40 VRB 68 85 70 84 / 30 30 30 30 LEE 69 86 70 84 / 20 50 30 50 SFB 68 86 69 84 / 30 50 30 50 ORL 68 86 69 85 / 30 50 30 50 FPR 68 85 71 84 / 30 30 30 30 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ SHORT TERM...PENDERGRAST LONG TERM....JOHNSON
AREA FORECAST DISCUSSION
NWS WICHITA KS
104 PM CDT SAT APR 11 2015 ...UPDATED FOR 18Z AVIATION DISCUSSION... .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 330 AM CDT SAT APR 11 2015 MID-LEVEL WARM ADVECTION AND A WEAK TRANSIENT SHORTWAVE ALOFT HAS OVERCOME SEEMINGLY MODEST MOISTURE AND RESULTED IN SCATTERED ELEVATED SHOWERS/ISOLATED STORMS FROM NORTH CENTRAL OKLAHOMA ACROSS SOUTHERN KANSAS EARLY THIS MORNING. THE LATEST RUC HAS THE BEST HANDLE ON THIS ACTIVITY WHICH LINGERS IT INTO THE 12Z- 15Z TIME FRAME ACROSS SOUTHEAST KANSAS. STRONGER ELEVATED LOW LEVEL MOISTURE TRANSPORT WILL DEVELOP ACROSS THE AREA TONIGHT AS ANOTHER SHORTWAVE ALOFT MIGRATES EAST ACROSS THE CENTRAL PLAINS. THIS WILL ALLOW DIURNAL CONVECTION ACROSS THE HIGH PLAINS LATER TODAY TO DEVELOP/MOVE EAST ACROSS MUCH OF THE AREA OVERNIGHT. SOME OF THIS ACTIVITY WILL LINGER INTO SUNDAY MORNING ACROSS SOUTHEAST KANSAS...BEFORE RENEWED SURFACE BASED CONVECTION DEVELOPS ALONG A SURFACE COLD FRONT WHICH WILL MOVE INTO CENTRAL KANSAS DURING THE AFTERNOON AS THE ASSOCIATED UPPER TROF MOVES ACROSS THE NORTHERN PLAINS. MODERATE INSTABILITY AND DEEP LAYER SHEAR SHOULD SUPPORT STRONG TO MARGINALLY SEVERE STORMS. WHILE INTENSITY SHOULD DECREASE BY SUNDAY EVENING...COVERAGE WILL LIKELY INCREASE ALONG THE FRONT AS IT MOVES INTO SOUTHEAST KANSAS. COOLER AND DRIER WEATHER IS STILL ON TAP FOR MONDAY. DARMOFAL .LONG TERM...(TUESDAY THROUGH FRIDAY) ISSUED AT 330 AM CDT SAT APR 11 2015 CHANCES FOR PRECIP LOOK TO INCREASE BY MID TO LATE NEXT WEEK WITH THE MEDIUM RANGE MODELS SHOWING AN UPPER TROF MOVING FROM THE ROCKIES AND BECOMING A CLOSED LOW ACROSS THE CENTRAL PLAINS. THERE IS STILL UNCERTAINTY IN THE EVOLUTION AND MOVEMENT/TRACK OF THIS SYSTEM...THOUGH FORECAST CONSENSUS SUPPORTS MODEST CHANCE POPS BY WEDNESDAY NIGHT AND THURSDAY. KED && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 104 PM CDT SAT APR 11 2015 FOR ICT-SLN-HUT-CNU-RSL...WEAK 800-600MB WARM/MOIST ADVECTION MAY SUPPORT A FEW ISOLATED SHOWERS THROUGH THE DAY GENERALLY ALONG/WEST OF I-135. THIS ACTIVITY WILL BE SPARSE SO LEFT OUT OF TAFS FOR NOW. ANTICIPATING SHOWER/THUNDERSTORM COVERAGE TO GRADUALLY INCREASE THIS EVENING AND OVERNIGHT FROM WEST-EAST...AS 850-700MB WARM/MOIST ADVECTION STRENGTHENS AHEAD OF SHORTWAVE ENERGY APPROACHING FROM THE WEST. DIFFICULT TO PINPOINT EXACTLY WHERE ACTIVITY WILL DEVELOP/MOVE AT THIS TIME...SO COVERED THREAT WITH VCSH/VCTS FOR NOW AT ALL TERMINALS...BUT ANTICIPATE TEMPO GROUPS WILL EVENTUALLY BE NEEDED. THINKING THUNDER THREAT WILL GRADUALLY EXIT THE REGION AFTER SUNRISE. FURTHERMORE...AFTER ABOUT 09Z...INCREASING LOW-LEVEL MOISTURE AND DIURNAL COOLING WILL SUPPORT CIGS LOWERING TO MVFR OR POSSIBLY EVEN IFR...ESPECIALLY ICT-HUT-SLN-RSL. ADK && .FIRE WEATHER... ISSUED AT 330 AM CDT SAT APR 11 2015 PERIODIC CHANCES FOR SHOWERS AND STORMS WILL EXIST ACROSS THE AREA THIS WEEKEND...WITH THE BEST CHANCES TONIGHT ACROSS CENTRAL KANSAS AND SUNDAY NIGHT ACROSS SOUTHEAST AND SOUTH CENTRAL KANSAS. OTHERWISE...INCREASING SOUTH WINDS WILL ELEVATE THE GRASSLAND FIRE DANGER THIS AFTERNOON IN RAIN-FREE AREAS AS WELL AS SUNDAY AFTERNOON. KED && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 71 56 77 53 / 30 40 40 60 HUTCHINSON 70 55 78 49 / 20 50 40 40 NEWTON 70 55 76 50 / 30 50 40 50 ELDORADO 71 56 76 53 / 50 50 40 60 WINFIELD-KWLD 70 56 76 55 / 30 30 40 70 RUSSELL 72 55 78 44 / 30 40 20 20 GREAT BEND 72 55 79 46 / 30 40 20 20 SALINA 74 55 78 46 / 20 60 40 30 MCPHERSON 71 55 77 48 / 20 60 40 40 COFFEYVILLE 73 54 77 57 / 40 30 40 70 CHANUTE 71 54 76 54 / 40 50 50 70 IOLA 71 53 75 54 / 30 60 50 70 PARSONS-KPPF 72 54 76 56 / 40 30 40 70 && .ICT WATCHES/WARNINGS/ADVISORIES...NONE. && $$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1255 PM EDT SAT APR 11 2015 LATEST UPDATE... HYDRO .SYNOPSIS... ISSUED AT 330 AM EDT SAT APR 11 2015 HIGH PRESSURE WILL BUILD IN AND BRING FAIR WEATHER THIS WEEKEND. A WEAK COLD FRONT WILL BRING SOME RAIN SHOWERS SUNDAY NIGHT THROUGH MIDDAY MONDAY FOLLOWED BY DRY AND MILD WEATHER FOR TUESDAY THROUGH WEDNESDAY. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 330 AM EDT SAT APR 11 2015 HIGH PRESSURE WILL BUILD INTO THE LOWER GREAT LAKES REGION TODAY AND BRING FAIR WX WITH SEASONABLE TEMPS. MAX TEMPS TODAY WILL RANGE FROM THE MIDDLE 50S TO AROUND 60 DEGREES. FAIR WX WILL CONTINUE TONIGHT THROUGH SUNDAY WITH THE RIDGE STILL IN CONTROL OF THE WX PATTERN. A WEAK COLD FRONT WILL BRING SOME RAIN SHOWERS LATE SUNDAY NIGHT THROUGH AROUND MIDDAY MONDAY. THUNDERSTORMS ARE NOT ANTICIPATED GIVEN LACK OF SFC OR ELEVATED INSTABILITY AND WEAK LIFT WITH THIS FRONT. FAIR WX WILL RETURN BEGINNING MONDAY AFTERNOON. .LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT 330 AM EDT SAT APR 11 2015 FOR THE MOST PART THE FIRST FEW DAYS (TUE/WED) WILL BE QUIET WITH A FAIR AMOUNT OF SUNSHINE AND PLEASANT MID SPRING TEMPERATURES. LATER IN THE WEEK... A SERIES OF PACIFIC SYSTEMS WILL TRY TO DIG SOME SORT UPPER LEVEL TROUGH THAT WILL PROGRESS WEST TO EAST ACROSS THE CONUS. HOW THIS PLAYS OUT IS ANYONE`S GUESS. THE ISSUE IS PHASING OF THE NORTHERN AND SOUTHERN STREAM. FOR NOW IT SORT OF LOOKS LIKE MOST OF THE SIGNIFICANT RAIN/THUNDERSTORMS WILL BE WELL SOUTH OF MICHIGAN INTO FRIDAY (NO PHASING). WE WOULD GET SOME SHOWERS THURSDAY / FRIDAY AS ONE OF THESE UNPHASED WAVES PASS THROUGH THE AREA. ONE THING TO WATCH IS WHAT HAPPENS TO THE SOUTHERN STREAM JET. IT IS CURRENTLY WELL SOUTH OVER THE EASTERN AND CENTRAL PACIFIC....NEAR 20N. IT SEEMS TO WANT TO STAY THERE THROUGH THE EXTENDED PERIOD. TO GET STRONG SYSTEM INTO MICHIGAN WE WOULD NEED A NORTHERN STREAM WAVE TO DIG FAR ENOUGH SOUTH TO TAP THAT ENERGY. CURRENTLY THAT IS DOES NOT SEEM TO WANT TO HAPPEN. SO FOR NOW I WILL FEATURE MOSTLY LOW CHANCE POPS THURSDAY INTO FRIDAY. WE WILL HAVE TO SEE HOW LATER MODEL RUNS PLAY THIS OUT. IF NOTHING ELSE TEMPERATURES WILL BE NEAR NORMAL NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 712 AM EDT SAT APR 11 2015 ONCE THE SUN HAS A CHANCE TO HEAT THE AIR ENOUGH TO START MIXING OF THE BOUNDARY LAYER... THE PATCHY FOG AT OUR EASTERN TAF SITES WILL QUICKLY MIX OUT (BY 14Z). MODEL SOUNDINGS SUGGEST SOME CU AROUND 4000 FT AGL TODAY BUT THE OUTGOING LONG WAVE RADIATION LOOP FROM THE 07Z HRRR DOES NOT SHOW ANY CU OVER OUR CWA TODAY EVEN SO. NO MATTER WHAT SKIES WILL BE CLEAR TONIGHT AND WINDS WILL BE LIGHT FROM THE SOUTH. && .MARINE... ISSUED AT 1128 AM EDT SAT APR 11 2015 WITH HIGH PRESSURE BUILDING IN...WE ARE NOT EXPECTING ANY MAJOR IMPACT TO MARINERS THROUGH TONIGHT. WINDS WILL PICK UP ON SUNDAY AND BOATING CONDITIONS WILL DETERIORATE THROUGH SUNDAY NIGHT. SMALL CRAFT ADVISORIES MAY BE NEEDED. && .HYDROLOGY... ISSUED AT 1255 PM EDT SAT APR 11 2015 MOST RIVER AND STREAM LEVELS ACROSS CENTRAL LOWER MICHIGAN ARE PEAKING OR ON THE WAY DOWN AFTER THE 2 TO 3.5 INCHES OF RAINFALL EXPERIENCED THIS PAST WEEK. THE WHITE RIVER AT WHITEHALL AND THE ROGUE RIVER AT ROCKFORD ARE THE ONLY SITES ABOVE FLOOD LEVELS. THESE SITES SHOULD BE IN A MINOR FLOOD STATE FOR A DAY OR TWO. MANY OTHER SITES HAVE PEAKED BELOW FLOOD LEVEL. SITES ACROSS SOUTHERN LOWER MICHIGAN RECEIVED ONLY AN INCH TO AN INCH AND A HALF OF RAIN... AND ARE NOT EXPERIENCING HIGH RIVER LEVELS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ SYNOPSIS...LAURENS SHORT TERM...LAURENS LONG TERM...WDM AVIATION...WDM HYDROLOGY...63 MARINE...MJS
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
419 PM CDT Sat Apr 11 2015 .DISCUSSION... Issued at 418 PM CDT SAT APR 11 2015 Tonight - Sunday Night: A fairly active period as first a weak mid level shortwave tracks ene out of CO as isentropic lift/warm air advection from 300K-310K surface expands/increases across KS into MO. This mostly a reflection of the nocturnal low-level jet ramping up and veering to the southwest. The sputtering elevated convection over southwest KS likely in response to the aforementioned h7 shortwave and isentropic ascent. Have patterned tonight`s PoPs from last several HRRR runs which is faster and further east with the precipitation. Seems reasonable as the models typically underplay how far downstream warm advection convection can extend. Elevated instability looks rather puny and only a few hundred J/kg so will go with isolated thunder. Small sub-severe hail possible. First wave of convection should lift northeast in the morning with maybe a sputtering second area following close on its heels. How the morning convection plays out and how much the clouds clear out will determine the strength of the stronger convection tied to the cold front. What is interesting is how the NAM generates pre-frontal convection along an instability axis with progged MLCAPEs in excess of 2000 J/kg. Since there have been at least 3 consecutive model runs generating this convection can`t totally dismiss it. The current forecast is constructed with the idea that pre-frontal convection will form late afternoon or early evening across northeast KS and northwest MO with the cold front generated convection eventually dropping southeast and merging. So, highest PoPs will be across the northwest 1/2 of the CWA in the evening and then allow the squalline to steadily translate southeast. The evening convection could contain some marginally severe hail due to the moderate instability and 30-40kt 0-6km shear which could support sufficient updraft strength. Monday - Tuesday: Looks like we`ll be in between minor shortwave ridging aloft shifting across the Northern Plains while a closed upper low lifts northeast from West TX. Will maintain a dry forecast although there is some concern that increasing warm air advection and weak lift tied to the upper low opening up as it heads our way could force us to add PoPs in later forecasts. Otherwise, dry surface high pressure on Monday with northeast winds should grant us highs in the 65-70 range. Tuesday should see at least increasing high clouds which will negate any boundary layer warming so max temperatures should keep highs in the 60s. Wednesday - Saturday: A very uncertain period as the medium range models bounce around with their solutions. The left overs from the closed upper low will linger on Wednesday so will use low end chance PoPs to handle any scattered light convection. Instability looks poor so thunder chances will be low. The rest of the period will be handled using a blended model approach. As the latest GFS is now trending closely with the last couple of runs of the ECMWF in handling the deep upper trough tracking through the Rockies am anticipating the next forecast or the one thereafter going towards drier conditions. The ECMWF has trended towards developing a cut-off low over the Southern Rockies and this solution is looking more and more likely, which would mean delaying PoPs and above average temperatures. && .AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon) Issued at 1220 PM CDT SAT APR 11 2015 Cloud cover to the south will continue to make its way north over the next few hours with ceilings around 10 kft. Will see convective activity develop overnight ahead of a low-level jet through Sunday morning. Initial isolated activity will commence near 08Z with prevailing thunderstorms after 10Z. Ceilings will likely stay VFR as convection will remain elevated Sunday morning. However, could see periodic reductions in visibility as thunderstorms move through the area. SSE winds will gradually become southerly, with gusts up to 20 kts expected Saturday afternoon and then Sunday morning with developing convective activity. Will see improving conditions late in the forecast period, with additional thunderstorms expected along a cold front Sunday evening. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ DISCUSSION...MJ AVIATION...Welsh
AREA FORECAST DISCUSSION
NWS RALEIGH NC
330 PM EDT SAT APR 11 2015 .SYNOPSIS...A SECONDARY COLD FRONT WILL MOVE ACROSS VA AND NC THROUGH THIS EVENING. CANADIAN HIGH PRESSURE WILL FOLLOW AND BUILD ACROSS THE MIDDLE ATLANTIC STATES THROUGH SUN...BEFORE DRIFTING OFFSHORE SUN NIGHT. && .NEAR TERM /THROUGH TODAY/... AS OF 1050 AM SATURDAY... A LEAD COLD FRONT HAD CLEARED ALL BUT BRUNSWICK COUNTY IN NC...WITH A TRAILING 1019 MB SFC RIDGE AXIS CENTERED OVER THE NW NC PIEDMONT. MEANWHILE...A SECONDARY FRONT WAS ANALYZED OVER NORTH-CENTRAL VA...AND THIS FRONT WILL CONTINUE TO MOVE SOUTH AND ACROSS CENTRAL NC WITH LITTLE SENSIBLE WEATHER IMPACT LATE THIS AFTERNOON AND EVENING. IT WILL INSTEAD SIMPLY MARK THE LEADING EDGE OF A PARENT... 1027 MB CANADIAN HIGH PRESSURE CENTERED NEAR THE IL/IN BORDER THAT WILL BUILD ACROSS THE MIDDLE ATLANTIC STATES THROUGH EARLY SUN. THE PREVIOUS FORECAST REPRESENTED THE CLEARING WELL PER RECENT SATELLITE TRENDS AND NEAR TERM MOISTURE PROGS...WHICH SUGGESTS THE BACK EDGE OF THE MAINLY MID-HIGH CLOUDINESS WILL CLEAR THE TRIANGLE BETWEEN NOON AND 1 PM...AND THE COASTAL PLAIN 2-3 HOURS LATER. SOME ADDITIONAL BUT THIN CIRRUS WILL STREAM EAST IN WESTERLY UPPER LEVEL FLOW...FROM THE NORTHERN GULF COAST STATES LATER THIS AFTERNOON. RECENT HRRR AND RAP FORECASTS SUPPORT PREVIOUSLY ADVERTISED HIGHS IN THE 70S. WITH SFC DEWPOINTS FALLING INTO THE 30S COURTESY OF GENERALLY NORTH TO NNW FLOW AROUND THE LEAD RIDGE AXIS OVER THE PIEDMONT...AND EVEN SOME 20S PROBABLE OVER THE NW PIEDMONT...THE AIR WILL FEEL MUCH LESS HUMID THAN RECENT DAYS && .SHORT TERM /TONIGHT THROUGH MONDAY/... AS OF 305 AM SATURDAY... HIGH PRESSURE BUILDS IN OVERNIGHT AND...WHILE THE SURFACE RIDGE AXIS GRADUALLY MOVES EAST...AT LEAST THE WESTERN END OF HIGH PRESSURE CONTINUES OVER CENTRAL NORTH CAROLINA THROUGH SUNDAY NIGHT. PLAN VIEW RELATIVE HUMIDITY FIELDS AND BUFR SOUNDINGS SHOW LIMITED MOISTURE IN OVERALL SUBSIDENCE THROUGH THE OVERNIGHT HOURS OF SUNDAY...WITH K INDICES NEAR ZERO OR BELOW. OVERNIGHT SUNDAY...THE NAM PROVIDES FOR MORE OF A RETURN FLOW WITH FASTER EASTWARD PROGRESS OF LOW PRESSURE OUT OF THE SOUTH PLAINS TOWARD THE LOWER MISSISSIPPI VALLEY...RESULTING IN JUST ENOUGH MOISTURE RETURN FOR THE POSSIBILITY OF LOW CLOUDS TOWARD THE IMMEDIATE TRIAD AND EVEN VERY MINOR QPF. THE GFS...ON THE OTHER HAND...IN MUCH SLOWER IN THE EASTWARD PROGRESS OF LOW PRESSURE...AND DRIER IN THE LOW LEVELS AT LEAST THROUGH 12Z MONDAY. UNCERTAINTY INCREASES SOME SUNDAY NIGHT WITH REGARD TO THE MOISTURE RETURN AND ITS INFLUENCE ON LOW TEMPERATURES THEN...AND FOR THIS FORECAST WILL LEAN TOWARD THE SLOWER SOLUTION DUE TO THE STRENGTH OF THE SURFACE HIGH AND THE SHARPENING RIDGE AXIS THAT EVEN THE NAM FORECASTS OVER THE CAROLINAS SUNDAY NIGHT INTO MONDAY. OVERNIGHT LOWS TONIGHT IN THE LOWER TO MID 40S...LIKELY AROUND 40 KTDF TO KLHZ NORTH...WITH HIGHS SUNDAY IN THE LOWER TO MID 70S...A LITTLE COOLER THAN TODAY OVERALL WITH 1000- 850MB THICKNESSES A FEW METERS LOWER. OVERNIGHT LOWS SUNDAY NIGHT WILL LIKELY BE QUITE VARIABLE THROUGHOUT THE 40S. -DJF && .LONG TERM /MONDAY THROUGH SATURDAY/... AS OF 326 PM SATURDAY... THE SURFACE HIGH WILL BE OFF THE EAST COAST ON MONDAY... SETTING UP SOUTHERLY RETURN FLOW AND INCREASING MOISTURE. ENERGY KICKING OUT FROM THE CLOSED LOW OVER THE SOUTHWEST MAY SUPPORT THE DEVELOPMENT OF SHOWERS OVERNIGHT... CONTINUING INTO TUESDAY AS A COLD FRONT CROSSES THE AREA. SLIGHTLY COOLER TEMPS IN THE UPPER 60S TO LOW 70S. HIGH PRESSURE WILL MOVE OVER THE NORTHEAST WEDNESDAY... WEDGING INTO THE AREA INTO THURSDAY. UPPER LEVEL FLOW OVER THE CONUS BECOMES INCREASINGLY AMPLIFIED ON WEDNESDAY... WITH A DEEP TROUGH MOVING IN TO THE WEST... BEFORE MODELS DEPICT A SPLIT FLOW REGIME DEVELOPING ON THURSDAY... WITH A CLOSED LOW OVER THE CENTRAL US. MODEL RUNS AT THIS POINT HAVE NOT LOCKED ON A CONSISTENT SOLUTION FOR THIS ENERGY... BUT AS IT MOVES EASTWARD... RAIN CHANCES WILL LIKELY INCREASE BY THE END OF THE WEEK ACROSS THE SOUTHEAST. WILL CONTINUE WITH NEAR NORMAL TEMPS THROUGH THIS PERIOD... HIGHS GENERALLY LOW 70S AND LOWS IN THE 50S... BUT THE TRACK OF THE UPPER LOW AND RESULTANT CLOUDINESS AND PRECIP COULD HAVE A SIGNIFICANT IMPACT ON TEMPERATURES LATE IN THE PERIOD. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... AS OF 155 PM SATURDAY... UNDER THE INFLUENCE OF CANADIAN HIGH PRESSURE BUILDING FROM THE OH VALLEY TO THE MIDDLE ATLANTIC STATES...VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. GENERALLY LIGHT SURFACE WINDS WILL GRADUALLY VEER FROM NORTHWESTERLY THIS AFTERNOON TO NORTHEASTERLY TONIGHT AND EAST TO SOUTHEASTERLY ON SUN...AS THE HIGH BUILDS SOUTHEASTWARD. PASSING CIRRUS IN WSW FLOW ALOFT WILL FILL AN OTHERWISE CLEAR SKY. OUTLOOK: THE CONCURRENT APPROACH OF A WARM FRONT FROM THE SOUTH AND A COLD FRONT FROM THE NORTHWEST WILL CULMINATE IN A GOOD CHANCE OF SUB-VFR CONDITIONS AND RAIN MON NIGHT THROUGH AT LEAST TUE...WITH SOME SUB-VFR CONDITIONS LINGERING AT FAY TROUGH TUE NIGHT...AND A REPEAT PERFORMANCE PROBABLE AGAIN LATE IN THE WEEK. && $$ SYNOPSIS...RAH NEAR TERM...RAH SHORT TERM...DJF/RAH LONG TERM...RAH AVIATION...RAH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
200 PM EDT SAT APR 11 2015 .SYNOPSIS...A SECONDARY COLD FRONT WILL MOVE ACROSS VA AND NC THROUGH THIS EVENING. CANADIAN HIGH PRESSURE WILL FOLLOW AND BUILD ACROSS THE MIDDLE ATLANTIC STATES THROUGH SUN...BEFORE DRIFTING OFFSHORE SUN NIGHT. && .NEAR TERM /THROUGH TODAY/... AS OF 1050 AM SATURDAY... A LEAD COLD FRONT HAD CLEARED ALL BUT BRUNSWICK COUNTY IN NC...WITH A TRAILING 1019 MB SFC RIDGE AXIS CENTERED OVER THE NW NC PIEDMONT. MEANWHILE...A SECONDARY FRONT WAS ANALYZED OVER NORTH-CENTRAL VA...AND THIS FRONT WILL CONTINUE TO MOVE SOUTH AND ACROSS CENTRAL NC WITH LITTLE SENSIBLE WEATHER IMPACT LATE THIS AFTERNOON AND EVENING. IT WILL INSTEAD SIMPLY MARK THE LEADING EDGE OF A PARENT... 1027 MB CANADIAN HIGH PRESSURE CENTERED NEAR THE IL/IN BORDER THAT WILL BUILD ACROSS THE MIDDLE ATLANTIC STATES THROUGH EARLY SUN. THE PREVIOUS FORECAST REPRESENTED THE CLEARING WELL PER RECENT SATELLITE TRENDS AND NEAR TERM MOISTURE PROGS...WHICH SUGGESTS THE BACK EDGE OF THE MAINLY MID-HIGH CLOUDINESS WILL CLEAR THE TRIANGLE BETWEEN NOON AND 1 PM...AND THE COASTAL PLAIN 2-3 HOURS LATER. SOME ADDITIONAL BUT THIN CIRRUS WILL STREAM EAST IN WESTERLY UPPER LEVEL FLOW...FROM THE NORTHERN GULF COAST STATES LATER THIS AFTERNOON. RECENT HRRR AND RAP FORECASTS SUPPORT PREVIOUSLY ADVERTISED HIGHS IN THE 70S. WITH SFC DEWPOINTS FALLING INTO THE 30S COURTESY OF GENERALLY NORTH TO NNW FLOW AROUND THE LEAD RIDGE AXIS OVER THE PIEDMONT...AND EVEN SOME 20S PROBABLE OVER THE NW PIEDMONT...THE AIR WILL FEEL MUCH LESS HUMID THAN RECENT DAYS && .SHORT TERM /TONIGHT THROUGH MONDAY/... AS OF 305 AM SATURDAY... HIGH PRESSURE BUILDS IN OVERNIGHT AND...WHILE THE SURFACE RIDGE AXIS GRADUALLY MOVES EAST...AT LEAST THE WESTERN END OF HIGH PRESSURE CONTINUES OVER CENTRAL NORTH CAROLINA THROUGH SUNDAY NIGHT. PLAN VIEW RELATIVE HUMIDITY FIELDS AND BUFR SOUNDINGS SHOW LIMITED MOISTURE IN OVERALL SUBSIDENCE THROUGH THE OVERNIGHT HOURS OF SUNDAY...WITH K INDICES NEAR ZERO OR BELOW. OVERNIGHT SUNDAY...THE NAM PROVIDES FOR MORE OF A RETURN FLOW WITH FASTER EASTWARD PROGRESS OF LOW PRESSURE OUT OF THE SOUTH PLAINS TOWARD THE LOWER MISSISSIPPI VALLEY...RESULTING IN JUST ENOUGH MOISTURE RETURN FOR THE POSSIBILITY OF LOW CLOUDS TOWARD THE IMMEDIATE TRIAD AND EVEN VERY MINOR QPF. THE GFS...ON THE OTHER HAND...IN MUCH SLOWER IN THE EASTWARD PROGRESS OF LOW PRESSURE...AND DRIER IN THE LOW LEVELS AT LEAST THROUGH 12Z MONDAY. UNCERTAINTY INCREASES SOME SUNDAY NIGHT WITH REGARD TO THE MOISTURE RETURN AND ITS INFLUENCE ON LOW TEMPERATURES THEN...AND FOR THIS FORECAST WILL LEAN TOWARD THE SLOWER SOLUTION DUE TO THE STRENGTH OF THE SURFACE HIGH AND THE SHARPENING RIDGE AXIS THAT EVEN THE NAM FORECASTS OVER THE CAROLINAS SUNDAY NIGHT INTO MONDAY. OVERNIGHT LOWS TONIGHT IN THE LOWER TO MID 40S...LIKELY AROUND 40 KTDF TO KLHZ NORTH...WITH HIGHS SUNDAY IN THE LOWER TO MID 70S...A LITTLE COOLER THAN TODAY OVERALL WITH 1000- 850MB THICKNESSES A FEW METERS LOWER. OVERNIGHT LOWS SUNDAY NIGHT WILL LIKELY BE QUITE VARIABLE THROUGHOUT THE 40S. -DJF MONDAY...A WEAK RIDGE WILL LINGER OVER THE AREA ON MONDAY AS THE HIGH MOVES OFFSHORE. THE RAIN SHOULD STAY LARGELY TO THE SOUTH AND WEST THROUGH THE DAY AS ANOTHER COLD FRONT APPROACHES...ALTHOUGH SOME RAIN MAY MOVE INTO THE WEST LATE IN THE DAY. HIGHS IN THE MID 70S. -RAH && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 305 AM SATURDAY... MONDAY NIGHT THROUGH TUESDAY NIGHT: THE RIDGE WILL BREAK DOWN OVERNIGHT AS THE HIGH MOVES FARTHER AWAY FROM SHORE. A COLD FRONT WILL EXTEND SSW THROUGH THE GREAT LAKES INTO THE MID WEST FROM THE PARENT LOW OVER EAST CENTRAL CANADA AT 00Z TUESDAY. THE FRONT WILL BECOME MORE WEST-EAST ORIENTED OVERNIGHT AS IT DISCONNECTS SOMEWHAT FROM THE PARENT LOW. THE SURFACE FLOW WILL BECOME MORE SOUTHERLY AS A WARM FRONT LIFTS NORTHWARD...ADVECTING WARM MOIST AIR INTO THE REGION. AS FAR AS RAIN CHANCES GO...THE 12Z ECMWF CONTINUES TO BE WETTER THAN THE 00Z GFS SOLUTION OVERNIGHT...HOWEVER BEST CHANCES EARLY ON WILL CONTINUE TO BE ACROSS THE WEST. EXPECT THE BEST CHANCES FOR RAIN ACROSS CENTRAL NC TO BE TUESDAY AND EARLY TUESDAY NIGHT AHEAD OF THE FROPA. A SURFACE HIGH WILL BUILD EAST INTO THE GREAT LAKES BEHIND THE COLD FRONT...WHICH SHOULD PUSH SOUTH INTO CENTRAL NC TUESDAY NIGHT. RAIN SHOULD BE OUT OF THE AREA BY EARLY WEDNESDAY...WITH HIGH PRESSURE RIDGING IN BEHIND IT. HIGHS ON TUESDAY WILL BE IN THE LOW TO MID 70S FROM NORTH TO SOUTH...AND GIVEN THE EXPECTED CLOUD COVER...WILL BE LARGELY DEPENDENT ON THE AMOUNT OF WARM AIR ADVECTED IN BEHIND AND TIMING/PROGRESSION OF THE WARM FRONT. MILD OVERNIGHT LOWS MONDAY NIGHT MAINLY IN THE MID TO UPPER 50S. LOWS TUESDAY NIGHT WILL DEPEND ON THE COLD FRONTAL PASSAGE...BUT FOR NOW EXPECT LOWS IN THE LOW TO MID 50S. WEDNESDAY THROUGH FRIDAY: HIGH PRESSURE WILL BUILD OVERHEAD...AND CONTINUE RIDGING INTO THE AREA AFTER IT MOVES OFFSHORE ON THURSDAY. THE MODELS REALLY START TO DISAGREE WITH RESPECT TO PRECIP DURING THIS TIME...WITH THE ECMWF WETTER THAN THE GFS...THUS CONFIDENCE IS NOT ALL THAT HIGH. FOR NOW...EXPECT WEDNESDAY TO REMAIN DRY WITH GRADUALLY INCREASING RAINFALL CHANCES WEDNESDAY NIGHT THROUGH FRIDAY. HIGHS WILL GENERALLY BE IN THE LOW TO MID 70S WITH LOWS IN THE LOW TO MID 50S. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... AS OF 155 PM SATURDAY... UNDER THE INFLUENCE OF CANADIAN HIGH PRESSURE BUILDING FROM THE OH VALLEY TO THE MIDDLE ATLANTIC STATES...VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. GENERALLY LIGHT SURFACE WINDS WILL GRADUALLY VEER FROM NORTHWESTERLY THIS AFTERNOON TO NORTHEASTERLY TONIGHT AND EAST TO SOUTHEASTERLY ON SUN...AS THE HIGH BUILDS SOUTHEASTWARD. PASSING CIRRUS IN WSW FLOW ALOFT WILL FILL AN OTHERWISE CLEAR SKY. OUTLOOK: THE CONCURRENT APPROACH OF A WARM FRONT FROM THE SOUTH AND A COLD FRONT FROM THE NORTHWEST WILL CULMINATE IN A GOOD CHANCE OF SUB-VFR CONDITIONS AND RAIN MON NIGHT THROUGH AT LEAST TUE...WITH SOME SUB-VFR CONDITIONS LINGERING AT FAY TROUGH TUE NIGHT...AND A REPEAT PERFORMANCE PROBABLE AGAIN LATE IN THE WEEK. && $$ SYNOPSIS...RAH NEAR TERM...RAH SHORT TERM...DJF/RAH LONG TERM...RAH AVIATION...RAH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
342 PM CDT SAT APR 11 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 343 PM CDT SAT APR 11 2015 FORECAST CHALLENGE FOR SHORT TERM WILL BE OVERNIGHT LOWS AND POTENTIAL FOR SOME WEAK CONVECTION SUNDAY AFTN. FOR IMMEDIATE SHORT TERM...HI RES MODELS HAVE DONE DECENT JOB HANDLING TODAYS HOURLY TEMPS...WITH 8 AM RUC RUN VERIFYING FAIRLY WELL WITH 3 PM OBSERVED TEMPS. HOWEVER...THIS HAS ONLY BEEN THE CASE IN REGIONS ACROSS THE SOUTHERN VALLEY WHERE DAYTIME MIXING HAS BEEN THE HIGHEST. THEREFORE USING RUC AS A STARTING POINT FOR TEMPS THROUGH 03Z...BUT NEEDING TO COOL OFF THE FAR EAST AND WEST WHERE WINDS ARE SLIGHTLY LESS. USED A FCST BLENDS FOR LOW POPS TOMORROW AFTN. TONIGHT...A SIGNIFICANT LLJ WILL DEVELOP...WITH H850 WINDS AROUND 50 KTS OVER N CNTRL MN BY 03Z. THIS WILL KEEP TEMPS UP WELL INTO THE EVENING FOR THE SOUTHERN VALLEY AND SOUTHEASTERN ZONES...AND USING RUC HOURLY TEMPS FOR THESE REGIONS. OVERNIGHT LOWS IN SOUTHERN VALLEY MAY STAY IN THE MID 50S WITH SOME MIXING CONTINUING THROUGHOUT THE NIGHT. TOUGHER AREA TO FCST WILL BE SOUTHEAST WHERE DAYTIME HIGHS WERE SIGNIFICANTLY COOLER HOWEVER THE AXIS OF THE LLJ WILL SHIFT OVER THAT AREA...WHEN THE LLJ STRENGTHENS...IN THE EARLY EVENING HOURS. ALSO POTENTIAL FOR SOME SHOWERS/CONVECTION TO DEVELOP IN THE EAST TOWARD MORNING. MEANWHILE BY EARLY MORNING WE WILL SEE SOME INCREASE IN SKY IN THE NORTHWEST AS MID CLOUDS NOW OVER MT ADVECT EAST...WITH SOME SHRA DEVELOPING OVERNIGHT IN CNTRL ND. TOMORROW...WILL SEE MORE SHRA AND POSSIBLY TSRA DEVELOP OVER N CNTRL MN BUT THE BEST THREAT FOR ANY HELPFUL RAINFALL AMOUNTS WILL BE EAST OF THE CWA. APPROACHING FROM FROM THE WEST MAY PRODUCE SOME RAINFALL SHOWERS MAINLY ALONG AND NORTH OF HWY 2...WITH SOME COOLER TEMPS ADVECTING IN DURING THE DAY. MAX TEMPS IN THE VALLEY AND ADJACENT COUNTIES IN MN MAY OCCUR IN THE EARLY AFTN AND REMAIN STEADY OF FALL SLIGHTLY IN THE AFTN. COOLER AND DRIER AIRMASS SHOULD BE IN PLACE ACROSS ENTIRE CWA BY 00Z MON. TOMORROW NIGHT...COOLER AIRMASS WILL BRING OVERNIGHT LOWS DOWN INTO THE 30S...WITH OVERNIGHT LOWS NEAR ZERO IN THE FAR NORTHWEST AND AROUND LAKE OF THE WOODS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 343 PM CDT SAT APR 11 2015 MONDAY WILL BE DRY WITH DAYTIME HIGHS AROUND 60. BREEZY WESTERLY WINDS WILL SUBSIDE OVERNIGHT...WITH STRONG SOUTHERLY WINDS DEVELOPING TUESDAY. TUESDAY WILL SEE A RETURN OF WARM WEATHER...WITH HIGHS IN THE 70S FOR MUCH OF THE AREA. FOR TUESDAY NIGHT THROUGH SATURDAY...MODELS CONTINUE TO DIFFER IN HOW MUCH SOUTHERN STREAM MOISTURE WILL GET DRAWN NORTHWARD AHEAD OF FRONTS MOVING EASTWARD THROUGH SOUTHERN CANADA AND THE NRN TIER OF THE U.S. 12Z ECMWF IS VERY MUCH SPLIT FLOW AND KEEPS THE SRN STREAM MOISTURE WELL TO OUR SOUTH UNTIL SYSTEM MOVES TO OUR EAST OVER THE GREAT LAKES REGION. 12Z GFS/GEM REMAINS A BIT WETTER WITH FRONT MOVING THROUGH WED AFTN-EVE. WILL MAINTAIN THE CHC POPS FOR SHOWERS. NEXT SYSTEM TO MOVE EAST WILL COME LATE SATURDAY...WHICH WILL THE SAME MOISTURE ISSUES THAN THE MID WEEK ONE WILL HAVE. LOOK FOR SLIGHTLY COOLER AIRMASS OVER THE AREA...BUT STILL 5-10 DEGREES ABOVE NORMAL. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 115 PM CDT SAT APR 11 2015 CLEAR SKIES OVER THE NEXT 24 HOURS. LIGHT NW WINDS WILL SHIFT TO THE SOUTH TONIGHT AS A SURFACE RIDGE OF HIGH PRESSURE SHIFTS EAST...HOWEVER SOUTHERLY WINDS TOMORROW WILL REMAIN RATHER LIGHT. && .FIRE WEATHER... ISSUED AT 343 PM CDT SAT APR 11 2015 GUSTY SOUTHERLY WINDS AND LOW RH WILL LEAD TO CONTINUED CRITICAL FIRE WEATHER CONDITIONS THROUGH LATE AFTERNOON OVER MUCH OF THE REGION. A COLD FRONT WILL SWING THROUGH ON SUNDAY...WITH WINDS BECOMING GUSTY FROM THE WEST IN ITS WAKE. WHILE TEMPS WILL BE SOMEWHAT COOLER ON SUNDAY...DEEP MIXING WILL RESULT IN LOW RH VALUES...LOWEST WEST OF THE VALLEY. NEAR CRITICAL CONDITIONS ARE POSSIBLE ESPECIALLY OVER SE ND...BUT THIS WILL DEPEND ON CLOUD AND TEMP TRENDS. RH MAY BE SOMEWHAT HIGHER FARTHER EAST WHERE THE FRONTAL PASSAGE WILL OCCUR LATER. FIRE WEATHER CONCERNS WILL CONTINUE INTO THE START OF THE WEEK...WITH GUSTY WEST WINDS AND VERY DRY AIR (RH NEAR OR UNDER 20 PERCENT) POSSIBLY LEADING TO CRITICAL CONDITIONS FOR MONDAY. TUESDAY MAY BE ANOTHER CRITICAL OR NEAR CRITICAL FIRE WEATHER DAY. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR NDZ008-016- 026>030-038-039-049-052>054. MN...RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR MNZ001>005-007- 008-013>015-022-023-027>031-040. && $$ SHORT TERM...SPEICHER LONG TERM...RIDDLE/SPEICHER AVIATION...RIDDLE FIRE WEATHER...MAKOWSKI
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1245 PM CDT SAT APR 11 2015 .UPDATE... ISSUED AT 1241 PM CDT SAT APR 11 2015 SO FAR WINDS HAVE BEEN A LITTLE BELOW EXPECTATIONS HOWEVER THE POTENTIAL FOR WIND GUSTS TO 30 MPH WILL BE WHEN THE ATMOSPHERE LINKS UP WITH THE 925 MB WINDS. EXPECT THIS TO OCCUR BETWEEN 1 AND 6 PM CDT. STILL LOOKS OK FOR RED FLAG AS THE MIN HR VALUES WILL BE IN THE TEENS. UPDATE ISSUED AT 922 AM CDT SAT APR 11 2015 SOUTHERLY 925 MB LOW LEVEL WINDS OF 35 KTS FROM RUC MODEL OVER THE JAMES RIVER VALLEY ASSOCIATED WITH THE WEAK SHOWERS EXITING THE JAMES RIVER VALLEY AT THIS TIME. THE WIND SPEEDS AT 925 SUGGEST SURFACE WINDS WINDS WILL PICK UP SOON AS WELL. HOWEVER MODEL SOUNDINGS SHOW THIS LOW LEVEL WIND MAX WILL MOVE EAST THIS AFTERNOON SO DO NOT EXPECT TO REALIZE THESE STRONG WINDS THERE. THERE WILL BE A RELATIVE WIND MAX THERE OF 20 TO 30 MPH. CURRENT STATUS OF RED FLAG WARNING REMAINS THE SAME AND LOOKS OK. UPDATE ISSUED AT 630 AM CDT SAT APR 11 2015 MAINLY CLEAR SKIES ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS MORNING. A WEAK WAVE MOVING ALONG THE NORTH DAKOTA/SOUTH DAKOTA BORDER IS PRODUCING SOME MID LEVEL CLOUDS FROM BISMARCK TO JAMESTOWN AND SOUTH INTO SOUTH DAKOTA. A SPRINKLE OR TWO MAY BE REACHING THE GROUND BUT NOT ENOUGH TO INCLUDE IN THE FORECAST AN HAVE REMOVED THE SLIGHT CHANCE OF SHOWERS THAT WAS IN THE FORECAST THROUGH 7 AM. OTHERWISE NO CHANGES TO THE GOING FORECAST...OR CURRENT FIRE WEATHER HEADLINES. && .SHORT TERM...(TODAY THROUGH MONDAY NIGHT) ISSUED AT 353 AM CDT SAT APR 11 2015 DEVELOPING LOW PRESSURE IN THE LEE OF THE ROCKIES WILL KEEP A SOUTHERLY/SOUTHWESTERLY WIND FLOW ACROSS THE FORECAST AREA TODAY. INCREASING SOUTHWESTERLY FLOW FROM THE SURFACE UP THROUGH H850 IN CENTRAL NORTH DAKOTA...AND UP THROUGH H700 IN WESTERN NORTH DAKOTA. THIS WILL ALLOW MIXING OF LOW LEVELS TO A DRY LAYER ALOFT. INCREASING SOUTH/SOUTHWEST WINDS THIS AFTERNOON TO 15 TO 25 MPH WITH HIGHER GUSTS. THE JAMES VALLEY MAY SEE THE STRONGEST WINDS MID AFTERNOON THROUGH EARLY EVENING...AS THE POCKET OF DRY/WINDY AIR ALOFT SHIFTS TO EASTERN NORTH DAKOTA AHEAD OF A SURFACE TROUGH THAT IS FORECAST TO MOVE INTO WESTERN NORTH DAKOTA LATER IN THE AFTERNOON. THIS WILL RAISE FIRE WEATHER CONCERNS FOR TODAY. SEE THE FIRE WEATHER SECTION BELOW FOR DETAILS. LOOKING AT A WARM DAY TODAY WITH HIGHS IN THE 70S WITH MOSTLY SUNNY SKIES. MEANWHILE AT UPPER LEVELS...A LONGWAVE TROUGH DEVELOPING OVER THE ROCKIES TODAY EXPANDS INTO THE WESTERN PLAINS TONIGHT...AND MOVES EAST ACROSS THE NORTHERN PLAINS SUNDAY AND MONDAY. TONIGHT A SURFACE COLD FRONT MOVES IN BEHIND THE SURFACE TROUGH WITH DECENT COLD ADVECTION. LOOK FOR A CHANCE OF SHOWERS AND POSSIBLY ISOLATED THUNDERSTORMS IN THE VICINITY OF THE FRONT. STRONG NORTHWEST WINDS ARE EXPECTED TO DEVELOP BEHIND THE COLD FRONT...AFTER MIDNIGHT IN THE NORTHWESTERN PART OF THE STATE AND BY DAYBREAK SUNDAY MORNING IN CENTRAL NORTH DAKOTA. BY LATE MORNING/EARLY AFTERNOON NORTHWEST WINDS OF 25 TO 35 MPH ARE EXPECTED WITH GUSTS OVER 40 MPH AT TIMES. A WIND ADVISORY WILL LIKELY BE NEEDED ACROSS ALL OF WESTERN AND CENTRAL NORTH DAKOTA SUNDAY. COOLER WITH HIGHS 50 TO 60. THE UPPER LEVEL TROUGH AND ASSOCIATED ENERGY IMPULSES WILL CREATE ENOUGH INSTABILITY FOR ISOLATED TO SCATTERED SHOWERS. SEE FIRE WEATHER SECTION BELOW FOR FIRE WEATHER CONCERNS ON SUNDAY. CONTINUED WINDY ON MONDAY. THE MAIN UPPER LEVEL TROUGH AXIS SHOULD BE EAST OF THE STATE. THE COMBINATION OF THE VIGOROUS DEPARTING LOW TO OUR EAST/NORTHEAST AND STRONG WARM AND DRY HIGH PRESSURE TO OUR SOUTHWEST WILL PROVIDE A TIGHT PRESSURE GRADIENT ACROSS THE STATE. YET ANOTHER DAY OF POTENTIAL FIRE WEATHER CONCERNS. A BIT WARMER WITH HIGHS IN THE LOWER 60S. .LONG TERM...(TUESDAY THROUGH FRIDAY) ISSUED AT 353 AM CDT SAT APR 11 2015 A PROGRESSIVE SPLIT FLOW PATTERN WILL CONTINUE THROUGH THE EXTENDED PERIOD. ON TUESDAY AN UPPER LEVEL TROUGH MOVES INTO THE NORTHERN ROCKIES WITH SURFACE LOW PRESSURE DEVELOPING IN THE LEE OF THE ROCKIES AND MOVING INTO THE MONDAK REGION BY 00 UTC WEDNESDAY. INCREASING SOUTHERLY FLOW AHEAD OF THE SURFACE LOW WILL BRING BREEZY CONDITIONS TO THE FORECAST AREA TUESDAY WITH TEMPERATURES CLIMBING INTO THE 70S...AND SOME 80 DEGREE READINGS POSSIBLE ACROSS THE SOUTH. WILL NEED TO MONITOR FOR POSSIBLE FIRE WEATHER HIGHLIGHTS AS THE LACK OF LOW LEVEL MOISTURE WILL MEAN ANOTHER DAY WITH LOW RELATIVE HUMIDITIES...ESPECIALLY OVER THE SOUTHWEST. STILL SOME CONCERNS AS TO WHETHER STRONGER WINDS WILL MATCH UP WITH THE LOW AFTERNOON HUMIDITIES. THE SURFACE LOW/COLD FRONT TRACKS ACROSS THE FORECAST AREA TUESDAY NIGHT FOLLOWED BY THE SPLITTING UPPER LEVEL TROUGH WEDNESDAY THROUGH WEDNESDAY NIGHT. BREEZY TO WINDY CONDITIONS TUESDAY NIGHT WITH SOUTHERLY FLOW AHEAD OF THE FRONT AND NORTHWEST WINDS BEHIND THE FRONT. RAIN SHOWER CHANCES ARE EXPECTED TO INCREASE FROM WEST TO EAST LATE TUESDAY NIGHT THROUGH WEDNESDAY JUST AHEAD OF THE UPPER LEVEL TROUGH. PRECIPITATION AMOUNTS WILL BE LIGHT WITH MOST AREAS SEEING THE POSSIBILITY OF UP TO A TENTH OF AN INCH...AND POSSIBLY LOCAL AMOUNTS UP TO A QUARTER INCH. COULD SEE A LINGERING SHOWER EARLY WEDNESDAY EVENING IN THE FAR EASTERN FORECAST AREA...BUT THEN UPPER LEVEL RIDGING QUICKLY BUILDS INTO THE NORTHERN PLAINS BY THURSDAY AND REMAINS THROUGH FRIDAY. THE GFS BRINGS ANOTHER QUICK MOVING COLD FRONT THROUGH THE AREA FRIDAY NIGHT WITH MINIMAL PRECIPITATION CHANCES. THE ECMWF IS SLOWER AND STRONGER WITH THIS SYSTEM BRINGING THE COLD FRONT THROUGH THE AREA ON SATURDAY. PRECIPITATION AMOUNTS WITH THE ECMWF ARE NOT THAT MUCH MORE IMPRESSIVE. EXCEPT FOR THE VERY MILD DAY ON TUESDAY...TEMPERATURES ARE EXPECTED TO REMAIN NEAR TO A LITTLE ABOVE NORMAL THROUGH SATURDAY WITH HIGHS MAINLY IN THE MID 50S TO MID 60S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1241 PM CDT SAT APR 11 2015 THE MAIN HIGHLIGHT OF THE FORECAST PERIOD WILL BE A STRONG COLD FRONT SWEEPING THROUGH THE STATE OVERNIGHT. WITH THIS BOUNDARY...EXPECT GUSTY SOUTHWEST WINDS SATURDAY AFTERNOON...SHIFTING TO GUSTY NORTHWEST WINDS BY LATE SUNDAY MORNING. VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. HIGH CLOUDS WILL INCREASE FROM WEST TO EAST BEGINNING LATE THIS AFTERNOON...WITH AN ISOLATED SPRINKLE OR TWO POSSIBLE AT KISN OR KDIK AFT 03Z ON SUNDAY. && .FIRE WEATHER... ISSUED AT 353 AM CDT SAT APR 11 2015 RED FLAG WARNING TODAY. EXPECT THAT RECENT RAIN/SNOW WEDNESDAY EVENING/NIGHT IN THE SOUTHWEST HAS MELTED/EVAPORATED OR FILTERED INTO THE TOPSOIL...AT LEAST KNOWING THAT PARTS OF THOSE SOUTHWESTERN COUNTIES DID NOT HAVE ANY SNOW COVER THE PAST COUPLE OF DAYS. NO REPORTS OF GRASSLANDS BEGINNING TO GREEN UP. RED FLAG CONDITIONS EXPECTED TODAY OVER MOST OF WESTERN AND ALL OF SOUTH CENTRAL NORTH DAKOTA. INCREASING SOUTH/SOUTHWEST WINDS OF 20 TO 25 MPH BY AROUND NOON...AFTERNOON TEMPERATURES IN THE 70S...AND AFTERNOON RELATIVE HUMIDITY VALUES OF 15 TO 20 PERCENT CAN BE EXPECTED TODAY. THIS INCLUDES WILLISTON AND BOWMAN...GARRISON TO JAMESTOWN AND SOUTH. FIRE WEATHER CONCERNS CONTINUE SUNDAY. CONFIDENT ON NORTHWEST WINDS OF 25 TO 35 MPH WITH HIGHER GUSTS. THIS IS FROM A COLD FRONTAL PASSAGE WITH EXPECTED HIGHS IN THE 50S. THERE SHOULD BE SUFFICIENT DRYING AT LOWER LEVELS FOR MINIMUM RELATIVE HUMIDITY VALUES OF AROUND 20 PERCENT SOUTH AND 25 TO 30 PERCENT NORTH. HOWEVER...EXPECTING SOME INCREASED CLOUD COVER WITH ISOLATED TO SCATTERED SHOWERS. MAY NEED A FIRE WEATHER WATCH/RED FLAG WARNING - ESPECIALLY FOR THE SOUTHERN HALF/TWO THIRDS OF THE STATE. CONTINUED WINDY MONDAY WITH HIGHS IN THE LOWER 60S...AND MINIMUM RELATIVE HUMIDITY OF 15 TO 25 PERCENT. WILL NEED TO MONITOR FOR POSSIBLE FIRE WEATHER HEADLINES. && .BIS WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR NDZ009-010-017>021-025-031>037-040>048-050-051. && $$ UPDATE...WAA SHORT TERM...JV LONG TERM...TWH AVIATION...WAA/ZH FIRE WEATHER...JV
AREA FORECAST DISCUSSION
NWS TULSA OK
1208 PM CDT SAT APR 11 2015 .DISCUSSION... THE 18Z TAF DISCUSSION IS INCLUDED BELOW. && .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. VFR CONDITIONS WILL PREVAIL THRU MUCH OF THE PERIOD. MID CLOUD AND RAIN SHOULD GRADUALLY LIFT OUT OF NE OK...BUT WILL NOT HAVE ANY MAJOR IMPACT TO AIRCRAFT OPS. MVFR CIGS ARE PROGGED TO RETURN EARLY SUNDAY AS LOW LVL MOISTURE RETURN GETS UNDERWAY ACROSS E OK. LACY && .PREV DISCUSSION... /ISSUED 948 AM CDT SAT APR 11 2015/ DISCUSSION... WARM ADVECTION/ISENTROPIC LIFT OCCURRING WELL ABOVE THE SURFACE ON THE COOL SIDE OF THE FRONT WHICH PASSED THRU A COUPLE DAYS AGO IS PRODUCING HIGH BASED SHOWERS...AND SOME LIGHTNING MAINLY WEST OF THE FORECAST AREA. THE MAJORITY OF THE DATA SUGGESTS PRECIP WILL HAVE A HARD TIME MAKING MUCH EASTWARD PROGRESS INTO OUR AREA...DESPITE WHAT IS CURRENTLY ON RADAR TO OUR WEST. TIME WILL TELL. THE BEST FORCING FOR ASCENT WILL GRADUALLY SHIFT NORTH BY TONIGHT. THE NEXT GOOD CHANCE FOR RAIN/STORMS WILL BE ON SUNDAY WHEN A FRONT DROPS IN FROM THE NORTH...AND MOISTURE INCREASES FROM THE SOUTH IN ASSOCIATION WITH A SOUTHERN STREAM UPPER WAVE. LACY PREV DISCUSSION... /ISSUED 551 AM CDT SAT APR 11 2015/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. ISOLATED SHOWERS WILL CONTINUE ACROSS EASTERN OK THIS MORNING BUT WITH MINIMAL ON AVIATION OPS. SOME LOWER VFR CEILINGS ARE POSSIBLE ACROSS NE OK AFTER 06Z SUNDAY WITH ISOLATED STORMS NEAR THE KANSAS BORDER. PREV DISCUSSION... /ISSUED 420 AM CDT SAT APR 11 2015/ DISCUSSION... UNSETTLED WEATHER WILL BE THE RULE OVER THE NEXT WEEK. SHOWERS AND A FEW THUNDERSTORMS ARE TRYING TO MOVE INTO PARTS OF EASTERN OKLAHOMA THIS MORNING BUT ARE HAVING SOME DIFFICULTY OVERCOMING THE DRY LOW LEVEL AIR IN PLACE. OVERALL PRECIPITATION COVERAGE AND INTENSITY IS EXPECTED TO REMAIN RATHER LOW IN OUR AREA TODAY ALTHOUGH THE HRRR DOES INDICATE AT LEAST ISOLATED ACTIVITY CONTINUING MUCH OF THE DAY. EXPECT TO SEE ENOUGH SUN THROUGH THE MID LEVEL CLOUDINESS TO ALLOW AFTERNOON TEMPERATURES TO WARM INTO THE 70S. SHOWER AND THUNDERSTORM CHANCES WILL BE HIGHEST NEAR THE KANSAS BORDER TONIGHT AND WILL BEGIN TO RAMP UP ACROSS THE AREA SUNDAY. THE MOST WIDESPREAD RAINFALL IS STILL EXPECTED SUNDAY NIGHT INTO MONDAY AS A COLD FRONT DROPS SOUTH THROUGH THE AREA. RAIN CHANCES WILL CONTINUE INTO MIDWEEK AS THE UPPER LEVEL STORM SYSTEM WILL LAG BACK OVER THE AREA. ANOTHER UPPER LEVEL SYSTEM WILL MOVE INTO THE AREA THURSDAY WITH MOST MODELS DEVELOPING A CLOSED UPPER LOW IN TEH VICINITY BY LATE WEEK. THIS WILL KEEP RAIN CHANCES GOING THROUGH THE END OF THE WEEK ALONG WITH COOLER TEMPERATURES. STAYED CLOSE TO GUIDANCE TEMPERATURES THE NEXT COUPLE DAYS. && .PRELIMINARY POINT TEMPS/POPS... TUL 57 79 61 72 / 20 30 70 50 FSM 54 80 63 74 / 10 40 60 70 MLC 58 77 61 72 / 10 40 70 60 BVO 54 80 58 72 / 20 30 70 30 FYV 53 77 59 69 / 10 30 60 60 BYV 52 76 59 70 / 10 20 60 60 MKO 55 78 61 72 / 10 30 60 60 MIO 52 78 58 71 / 20 30 70 40 F10 58 77 61 72 / 10 30 60 60 HHW 57 76 63 74 / 10 50 80 70 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ AVIATION...30
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1222 PM CDT SAT APR 11 2015 .AVIATION... DIFFICULT TAF FORECAST FOR THE NEXT 24/30 HOURS WITH CONTINUED IFR CONDITIONS EXPECTED AND CONTINUED POSSIBILITIES OF SHOWERS. CURRENTLY...CEILINGS ARE BORDERLINE LIFR/IFR WITH VISIBILITIES SLOWLY IMPROVING. A BATCH OF SHOWERS IS CURRENTLY MOVING INTO BEXAR COUNTY AND WILL BEGIN TAFSAT/TAFSSF WITH -SHRA FOR THIS ACTIVITY. LATEST GUIDANCE NOW SUGGESTS THAT THE IFR CEILINGS WILL NOT IMPROVE WITH IFR REMAINING IN PLACE THROUGH THE EVENING AND OVERNIGHT HOURS. THINK THIS IS PLAUSIBLE GIVEN CURRENT OBSERVATIONS AND SATELLITE TRENDS. CONDITIONS SHOULD IMPROVE TO MVFR AROUND NOON TOMORROW. REGARDING PRECIP CHANCES FOR THE REMAINDER OF THE VALID TAF PERIOD...ACTIVITY SHOULD REMAIN MORE SCATTERED THAN CONTINUOUS. BECAUSE OF THIS...IT IS EXTREMELY DIFFICULT TO PIN DOWN A PRECISE TIME WHEN ANY GIVEN TERMINAL WILL BE DEALING WITH PRECIPITATION. WILL CONTINUE TO HANDLE THIS WITH A VCSH GROUP FOR MOST OF THE PERIOD AND TRY TO GIVE SOME HEADS UP OF PREVAILING ACTIVITY WITH AMENDMENTS AND FUTURE ROUTINE ISSUANCES. GIVEN THE ABUNDANT CLOUD COVER AND TEMPERATURES REMAINING IN THE 60S...THINK THUNDER CHANCES ARE LOWER AND WILL OPT NOT TO MENTION THUNDER AT THIS TIME. HAMPSHIRE && .PREV DISCUSSION... /ISSUED 1057 AM CDT SAT APR 11 2015/ UPDATE... MID TO UPPER LEVEL MOISTURE CONTINUES TO PUSH ACROSS THE AREA FROM THE EASTERN PACIFIC. LATEST RAP40 ANALYSIS SHOWS SEVERAL SHORT WAVES ACROSS NORTHWEST AND NORTH CENTRAL MEXICO AS THEY MOVE TO THE NORTHEAST. SPC MESOANALYSIS PAGE SHOWS RICH TROPICAL AIRMASS PUSHING FROM THE SOUTH AT LOW LEVELS AND THE 12Z KDRT SOUNDING BACK THIS UP. AS OF NOW...AREA RADARS ARE SHOWING SOME LIGHT ECHOES ACROSS 2/3 OF THE REGION WITH ISOLATED MODERATE SHOWERS ACROSS THE SOUTHERN COUNTIES. THIS ACTIVITY IS EXPECTED TO INCREASE AS THE DAY PROGRESSES AND THE SHORT WAVE DISTURBANCE OUT WEST NEARS LATER THIS AFTERNOON AND EVENING. HIRES MODELS ARE ALL OVER THE PLACE WITH THE FIRST WAVE BUT THEY ARE MORE IN LINE WITH A SECOND DISTURBANCE TO COME ACROSS THE AREA SUNDAY AFTERNOON AND EVENING. SPC DAY ONE OUTLOOK KEEPS THE SOUTHWEST COUNTIES UNDER A MARGINAL RISK FOR SEVERE STORMS MAINLY THIS AFTERNOON AND EVENING. THEREFORE...CAN`T RULE OUT FEW STRONG TO SEVERE STORMS OUT WEST MAINLY ALONG AND SOUTH OF HIGHWAY 57. MAIN HAZARDS FOR THIS PERIOD WILL BE DAMAGING WIND GUSTS AND LARGE HAIL. FOR SUNDAY/SPC DAY 2 OUTLOOK...A MARGINAL RISK FOR SEVERE STORMS EXISTS OVER MUCH OF THE AREA WITH ISOLATED STRONG TO SEVERE STORMS POSSIBLE AND CAPABLE OF PRODUCING DAMAGING WIND GUSTS AND LARGE HAIL. ALSO...ANOTHER AREA OF CONCERN FOR SUNDAY AFTERNOON/ EVENING INTO THE OVERNIGHT HOURS IS LOCALLY HEAVY RAINS. GFS/NAM/EWC STORM RAINFALL TOTALS FOR THE NEXT 48 HOURS RANGE FROM 1 TO 2 INCHES ALONG AND EAST OF I-35 WITH 2 TO 3 INCHES ACROSS THE FAR SOUTHEAST COUNTIES. STAY TUNED AND CLOSELY MONITOR THE WEATHER CONDITIONS THROUGH THE WEEKEND FOR UPDATED INFORMATION AS THIS WET PATTERN AFFECT THE AREA. && PREV DISCUSSION... /ISSUED 341 AM CDT SAT APR 11 2015/ SHORT TERM (TODAY THROUGH SUNDAY NIGHT)...GOOD CHANCES FOR RAINFALL THE NEXT 48 HOURS ACROSS SOUTH-CENTRAL TEXAS. A MOIST MID AND UPPER LEVEL TAP FROM THE PACIFIC WILL CONTINUE OVERHEAD. THE LOWEST LEVELS ARE CURRENTLY RELATIVELY DRY BEHIND YESTERDAYS COLD FRONT...ESPECIALLY ACROSS NORTHERN AREAS WHERE DEW POINTS ARE IN THE LOW 50S. THIS WILL MODIFY AS A WARM FRONT LIFTS BACK NORTH THROUGH THE AREA DURING THE MORNING...AND LOW LEVEL H85 THETA-E ADVECTION SETS UP OVER THE REGION THROUGH TOMORROW. PWAT VALUES ARE FORECAST TO INCREASE TO AROUND 1.5-1.7 INCHES BY THIS AFTERNOON AND CLOSER TO 1.8-1.9 INCHES EAST OF I-35 SUNDAY AND SUNDAY NIGHT...WELL ABOVE 2 STANDARD DEVIATIONS OF THE MEAN FOR THIS TIME OF YEAR. THE WARM FRONT LIFTING BACK THROUGH THE AREA WILL SERVE AS FOCUS FOR FORCING TODAY. HAVE FOLLOWED CLOSER TO THE HRRR AND SREF THROUGH THE NEXT 12 HOURS...WHICH SEEM TO BE RELATIVELY BETTER WITH ONGOING CONVECTION SOUTH AND WEST OF THE CWA. WITH NO CAP IN PLACE...SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP MID MORNING ACROSS THE WESTERN AND SOUTHERN CWA AND EXPANDING NORTHEAST THROUGH THE AFTERNOON. AN UPPER LEVEL LOW OFF THE SOUTHERN CALIFORNIA COAST WILL MOVE EAST THROUGH BAJA CALIFORNIA TONIGHT...AND THROUGH NORTHERN MEXICO AND INTO FAR WEST TEXAS SUNDAY AND SUNDAY NIGHT. TIMING OF MID LEVEL DISTURBANCES IN THE SOUTHWEST FLOW ALOFT IS DIFFICULT. GENERALLY ECMWF AND GFS ARE SHOWING TONIGHT THROUGH SUNDAY MORNING FORCING INCREASING OUT OF SOUTH AND DEEP SOUTH TEXAS THROUGH EASTERN PORTIONS OF THE EWX CWA...AND THEN A SECOND DISTURBANCE LATE SUNDAY NIGHT INTO MONDAY MORNING COMING OUT OF MEXICO WEST TO EAST ACROSS THE EWX CWA. THE UPPER LEVEL PATTERN BECOMES BROADLY DIFFLUENT OVER THE REGION SUNDAY AND SUNDAY NIGHT BETWEEN AFOREMENTIONED UPPER LEVEL LOW TO THE WEST-NORTHWEST AND SOUTHERN STREAM SUBTROPICAL JET STREAK ACROSS DEEP SOUTH TEXAS AND MEXICO. THIS ALL INDICATES HIGH CHANCES FOR MULTIPLE ROUNDS OF PRECIP THROUGH EARLY MONDAY MORNING. CAN NOT RULE OUT A FEW STRONGER STORMS...MAINLY SOUTHERN AND WESTERN AREAS WHERE DEEP LAYER SHEAR IS BETTER...BUT OVERALL THE MOIST NATURE OF THE COLUMN LOOKS MORE OF INDICATIVE OF LOCALLY HEAVY RAIN POTENTIAL. RAINFALL TOTALS THROUGH MONDAY MORNING LOOK TO AVERAGE AROUND 1/2 TO 1 INCH ALONG THE RIO GRANDE...1 TO 2 INCHES ACROSS THE HILL COUNTRY AND I-35 CORRIDOR...AND 2 TO 3 INCHES EAST OF I-35. A FEW POCKETS OF HEAVIER RAINFALL TOTALS ARE POSSIBLE...ESPECIALLY SOUTHERN AND EASTERN AREAS. LONG TERM (MONDAY THROUGH FRIDAY)...DRIER AIR DOES WORK INTO THE RIO GRANDE AND HILL COUNTRY ON MONDAY WITH DECREASING POPS WEST TO EAST. THE UPPER LEVEL LOW EVENTUALLY OPENS AND SHEARS NORTHEAST MONDAY NIGHT AND TUESDAY...AND A WEAK COLD FRONT ENTERS SOUTH- CENTRAL TEXAS TUESDAY. SHOULD SEE ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS TUESDAY WITH DEEP MOISTURE STILL POOLED ALONG AND EAST OF THE I-35 CORRIDOR. EVENTUALLY THE UPPER LEVEL TROUGH DEEPENS THROUGH THE ROCKIES AND INTO THE PLAINS WEDNESDAY INTO THURSDAY...SENDING A STRONGER COLD FRONT INTO THE AREA ON THURSDAY OR THURSDAY NIGHT. WITH A STRONG SUB-TROPICAL TAP FROM THE PACIFIC CONTINUING IT APPEARS ANOTHER GOOD CHANCE FOR PRECIP WILL OCCUR DURING THIS TIME. DRIER AND MORE SEASONAL CONDITIONS FRIDAY INTO SATURDAY. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 69 66 78 65 82 / 60 70 70 90 40 AUSTIN BERGSTROM INTL AIRPORT 71 66 77 65 81 / 60 70 70 90 40 NEW BRAUNFELS MUNI AIRPORT 71 66 78 64 84 / 60 70 70 90 40 BURNET MUNI AIRPORT 70 64 77 63 81 / 60 60 60 80 40 DEL RIO INTL AIRPORT 74 66 80 63 85 / 60 40 50 70 10 GEORGETOWN MUNI AIRPORT 69 65 76 65 81 / 50 70 70 80 40 HONDO MUNI AIRPORT 74 66 79 64 84 / 60 60 60 90 20 SAN MARCOS MUNI AIRPORT 71 66 77 65 82 / 60 70 70 90 40 LA GRANGE - FAYETTE REGIONAL 73 68 77 68 81 / 60 60 70 80 50 SAN ANTONIO INTL AIRPORT 73 67 79 66 83 / 60 70 60 90 30 STINSON MUNI AIRPORT 72 68 79 66 84 / 60 70 60 90 30 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...29 SYNOPTIC/GRIDS...17 PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1118 AM CDT SAT APR 11 2015 .UPDATE... LATEST MORNING MODEL RUNS HAVE OFFERED LITTLE REASON TO CHANGE THE FORECAST FOR THIS AFTERNOON. THE MAIN ISSUE MODELS AND FORECASTERS SEEM TO BE STRUGGLING WITH IS IF WE WILL SEE STORM INITIATION BY LATE THIS AFTERNOON. THERE IS STILL NO DISCERNIBLE SHORTWAVE IN THE FLOW ALOFT WHICH WILL MAKE INITIATION A LITTLE MORE DIFFICULT. WE WILL HAVE TO RELY ON DRYLINE CONVERGENCE AND ABUNDANT SURFACE HEATING. LOW STRATUS HAD FORMED WHEN MORNING CONVECTION CLEARED OUT BUT IS NOT EXPECTED TO PERSIST FOR MUCH LONGER ALLOWING FOR FULL SUNSHINE. OTHERWISE...THERMODYNAMIC PARAMETERS LOOK GOOD FOR SEVERE THUNDERSTORM DEVELOPMENT. SURFACE HEATING INTO THE 70S WILL ALLOW FOR SURFACE BASED INSTABILITY TO REACH BETWEEN 1500 AND 2000 J/KG WITH MINIMAL CIN NEAREST THE DRYLINE. THERE WILL BE AN INCREASING CAP TO THE EAST PREVENTING MUCH DEVELOPMENT IN THE ROLLING PLAINS. LOW LEVEL THETA-E VALUES WERE ON THE INCREASE THIS MORNING AS DEPICTED IN THE RAP ANALYSIS. LOW AND DEEP LAYER SHEAR VALUES ARE FAVORABLE FOR ROTATING UPDRAFTS. DEW POINTS IN THE 50S WILL NOT GIVE US LOW LCLS BUT WILL NOT BE VERY HIGH WITH TEMPERATURES ONLY IN THE 70S. MODELS ARE AGREEING UPON A SLIGHT BULGE IN THE DRYLINE DIRECTLY OVER THE SOUTH PLAINS WHICH MAY ALLOW THE STRONGEST AREA OF INTEREST TO BE OVER THE NORTHERN SOUTH PLAINS AND SOUTHERN TEXAS PANHANDLE. GIVEN THE ABOVE REASONING...IF WE DO SEE INITIATION...STORMS WOULD LIKELY BECOME SEVERE QUICKLY. THERE IS A CHANCE OF TORNADOES GIVEN THE FAVORABLE LOW LEVEL SHEAR BUT LARGE HAIL WILL BE THE PRIMARY THREAT. && .PREV DISCUSSION... /ISSUED 624 AM CDT SAT APR 11 2015/ AVIATION... SCATTERED -TSRA WERE EAST OF KLBB AND KPVW EARLY THIS MORNING...WHILE ISOLATED -SHRA/-TSRA HAVE DEVELOPED WEST AND EAST OF KCDS AND HAVE THEREFORE INSERTED A VCSH FOR A FEW HOURS AT KCDS. COMPUTER MODELS HINT AT -TSRA POPPING UP NEAR KLBB AND KPVW THIS MORNING BUT CONFIDENCE OF INSERTING A MENTION IS LOW AT THIS TIME. VFR DECKS ARE EXPECTED TO DETERIORATE TO MVFR CRITERIA LATER THIS MORNING AT ALL THREE TAF SITES UNTIL EARLY AFTN WHEN CONDITIONS IMPROVE TO VFR. ADDITIONAL -TSRA ARE EXPECTED TO DEVELOP WEST OF KLBB AND KPVW THIS AFTERNOON...AND COULD POSSIBLY AFFECT ALL THREE TAF SITES AS THE ACTIVITY SHIFT EASTWARD WITH TIME. FURTHERMORE...SOME STORMS COULD BECOME STRONG TO SEVERE WITH HAIL AND GUSTY WINDS BEING THE PRIMARY THREATS. NOT CONFIDENT ENOUGH TO INSERT A PRECIP MENTION FOR THIS AFTERNOON BUT WILL OF COURSE AMEND AS NECESSARY. TONIGHT AS THE PRECIPITATION ACTIVITY SHIFT EAST AND AWAY FROM THE TERMINALS...COULD SEE VFR/MVFR FOG AND MVFR DECKS DEVELOP GIVEN THE MOIST ATMOSPHERIC CONDITIONS...THOUGH S-SE WIND SPEEDS STAYING UP A BIT MAY MITIGATE FOG POTENTIAL. PREV DISCUSSION... /ISSUED 328 AM CDT SAT APR 11 2015/ SHORT TERM... SOUTHWESTERLY FLOW ALOFT HAS SHARPENED IN THE LAST 24 HOURS...COURTESY OF A CLOSED UA LOW ACROSS THE ERN PACIFIC /WELL WEST OF BAJA OF CALI/ THAT IS GRADUALLY DRIFTING SSEWRD. AS SUCH...A PLUME OF RICH PACIFIC MOISTURE IS STREAMING ACROSS THE SOUTHERN PLAINS. LOOKING AT THE SFC...THE SOUTH PLAINS AND ROLLING PLAINS WAS ENVELOPED BY AN UPSLOPE SFC REGIME PER 07Z METARS...WHICH HAS GARNERED DEWPOINTS TO INCREASE INTO THE 30S AND 40S AND HENCE HAVE PWATS OF 0.75-0.85 INCHES. THIS RISE IN LOW LEVEL MOISTURE...COUPLED WITH A 25-35 KT LLJ AND AND INCREASING ISENTROPIC UPGLIDE...HAS LED TO THE DEVELOPMENT OF ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ACROSS ERN NM THAT HAS TRANSLATED ENEWRD TO ACROSS THE SW SOUTH PLAINS AND PORTIONS OF THE CNTRL SOUTH PLAINS EARLY THIS MORNING. THE TTU MESONET SITE LOCATED 7 MILES WNW OF DENVER CITY RECORDED 0.13 INCHES OF RAINFALL WITHIN 20 MINUTES DUE TO THIS ACTIVITY. COULD ALSO SEE BRIEF WIND GUSTS OF 20-30 MPH AS THIS ACTIVITY IS PROGGED TO MOVE ACROSS PORTIONS OF THE ROLLING PLAINS LATER THIS MORNING. FURTHERMORE...THE SURGE IN MOISTURE COULD PROMOTE MVFR CLOUD DECKS BY DAYBREAK. THIS AFTN COULD SHAPE UP TO BE QUITE INTERESTING. S-SE SFC WINDS WILL PREVAIL ACROSS THE CWA WHILST SWRLY SFC WINDS OCCUR MORE SO ACROSS ERN NM...THUS SHARPENING THE DEVELOPMENT OF A DRYLINE ALONG THE TX/NM BORDER. AT FIRST A BIT OF CIN WILL NEED TO BE OVERCOME BUT BY LATE AFTN...CIN IS QUITE NEGLIGIBLE ESPECIALLY NEAR THE AXIS OF THE DRYLINE AND THUS MODEL SOLUTIONS BREAK OUT PRECIP ACROSS LOCALES ON THE CAPROCK AS THE DRYLINE BULGES A BIT EWRD. STEEPENING LAPSE RATES...MUCAPE VALUES INCREASING TO AOA 1000 J/KG AND A WEAK IMPULSE EMBEDDED IN THE FLOW ALOFT MOVING ACROSS THE REGION BY LATE AFTN WILL LEAD TO CONCERNS FOR STORMS TO REACH STRONG TO POSSIBLY SEVERE LEVELS. MAIN SEVERE CONCERNS WILL BE HAIL AROUND THE SIZE OF GOLF BALLS AND WIND GUSTS OF 58 MPH OR GREATER. HOWEVER...VEERING VERTICAL WIND PROFILES AS WELL AS ADEQUATE VEERING AT THE LOW LEVELS /0-6 KM BULK SHEAR VALUES OF 35-45 KTS/ DOES SUGGEST STORMS WILL BE ROTATING...AND THUS AN ISOLATED TORNADO CAN NOT BE RULED OUT. THOUGH LCL/S ARE NOT TERRIBLY LOW /5000 FT AGL OR SO/. MAKE SURE YOU STAY ABREAST OF THE LATEST WX CONDITIONS BY LISTENING TO YOUR NOAA WX RADIO...GOING TO OUR WEBSITE /WWW.WEATHER.GOV/LUBBOCK/ AND/OR WATCHING YOUR FAVORITE MEDIA OUTLET. TONIGHT...BEST POPS WILL SHIFT EWRD TO ACROSS THE ROLLING PLAINS AND THE RETURN OF THE LLJ /30-40 KTS/ WILL AID IN FEEDING THE STORM ACTIVITY UNTIL IT EXITS THE REGION. ENSUING S-SE SFC WINDS MAY BRING ABOUT THE DEVELOPMENT OF A STRATUS DECK AND/OR FOG LATE TONIGHT/EARLY SUNDAY MORNING. AN UPTICK IN 850 MB TEMPS WILL LEAD TO TEMPS A FEW DEGREES WARMER THAN YESTERDAY /70S/ FOLLOWED BY A MILD NIGHT /50S AND 60S/. LONG TERM... AN EXTENDED PERIOD OF RAIN CHANCES STILL LOOKS GOOD FOR THE FCST AREA THROUGH MONDAY NIGHT WITH THE APPROACH OF AN UPPER LEVEL LOW THAT AS OF EARLY THIS MORNING WAS STILL WELL OFF THE COAST OF SRN AND BAJA CALIFORNIA. MODELS CONTINUE TO BE IN GOOD AGREEMENT WITH THE EVOLUTION OF THIS LOW...STILL TRACKING IT SLIGHTLY FURTHER TO THE SOUTH WITH EACH RUN. ATTM SUNDAY LOOKS LIKELY TO BE DRY UNTIL LATER IN THE AFTN WHEN THE COMBINATION OF LARGE SCALE ASCENT FROM THE UPPER LOW AND AFTERNOON HEATING WORK ON A REASONABLY MOIST AIR MASS TO BEGIN SPREADING SCATTERED SHOWERS AND THUNDERSTORMS NWD FROM THE PERMIAN BASIN. SUNDAY NIGHT WILL BEGIN TO SEE RAIN CONCENTRATED ALONG THE DEFORMATION AXIS TO THE NORTH OF THE UPPER LOW...THE LOCATION OF WHICH WILL DEPEND ON THE TRACK OF THE LOW...THUS A FARTHER SOUTH TRACK SIMILAR TO THE 00Z WRF-NAM WILL BE MORE FAVORABLE FOR THE FCST AREA. MONDAY MIGHT END UP BEING THE WETTEST...AT LEAST AS FAR AS HOW MUCH OF THE FCST RECEIVES RAINFALL...AS EVEN IF THE TRACK OF THE LOW IS FARTHER NORTH... DIURNAL DESTABILIZATION OF THE MOIST AIR MASS UNDERNEATH THE LOW ITSELF WOULD LIKELY LEAD TO QUITE A BIT OF SHOWER ACTIVITY. EFFECT OF A COLD FRONT DRAPED ACROSS THE AREA CANNOT BE DISCOUNTED EITHER...POSSIBLY SERVING AS ANOTHER FOCUS FOR CONVECTIVE DEVELOPMENT. ALL IN ALL CONFIDENCE CONTINUES TO INCREASE AND WILL NUDGE POPS UP IN THAT SUNDAY NIGHT THROUGH MONDAY NIGHT PERIOD. THE LATTER HALF OF THE PERIOD STILL LOOKS GENERALLY BENIGN... ALTHOUGH MODELS CONTINUE TO STRUGGLE WITH THE EVOLUTION OF THE NEXT UPPER TROUGH. 00Z GFS AND ECMWF HAVE TRENDED TOWARD A SOLUTION WITH MORE ENERGY IN THIS TROUGH...CUTTING OFF A FAIRLY STRONG LOW OVER THE CNTL PLAINS THEN DRIFTING IT EWD. COULD SEE A BRIEF PERIOD FOR SHOWERS WEDNESDAY AFTN OR NIGHT AND INTRODUCED A SLIGHT CHANCE FOR THEN. OTHERWISE...COOLER AIR SHOULD MOVE SWD BEHIND THIS DEVELOPING TROUGH/LOW WITH TEMPS COOLING AGAIN FOR THURSDAY. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 75 51 78 48 / 20 20 30 60 TULIA 72 56 79 54 / 40 20 30 60 PLAINVIEW 73 57 79 56 / 40 20 30 60 LEVELLAND 78 57 79 51 / 30 20 40 60 LUBBOCK 76 58 80 54 / 30 20 40 60 DENVER CITY 80 57 78 53 / 20 20 40 50 BROWNFIELD 78 58 80 52 / 30 20 40 50 CHILDRESS 73 60 82 60 / 50 30 30 60 SPUR 73 60 80 56 / 50 20 40 60 ASPERMONT 77 62 83 60 / 50 30 40 50 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 01