Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/23/12


AREA FORECAST DISCUSSION
NWS NEW YORK NY
931 AM EDT MON MAY 21 2012 .SYNOPSIS... A SERIES OF LOW PRESSURE SYSTEMS WILL IMPACT THE AREA THROUGH TUESDAY. A COLD FRONT MOVES THROUGH THE REGION ON WEDNESDAY... FOLLOWED BY ANOTHER COLD FRONT ON SATURDAY. HIGH PRESSURE RETURNS THEREAFTER. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LOW CLOUDS AND FOG DEVELOPED ACROSS THE COASTAL SECTIONS...WITH PATCHY DRIZZLE...EARLY THIS MORNING. VISIBILITIES HAVE LOWERED QUICKLY. UPDATED TO INCLUDE THE FOG AND DRIZZLE THIS MORNING. WILL CONFINE SHOWERS TO NYC AND AREAS JUST TO THE WEST OF THE CITY FOR SEVERAL HOURS THIS MORNING...THEN SHOWERS INCREASE IN COVERAGE SLOWLY FROM SW TO NE. THIS REFLECTS WELL IN THE HRRR AND RAP IN THE NEAR TERM. COULD TAKE SOMETIME FOR INTERIOR ZONES TO SEE PRECIP AS ENOUGH DRY AIR REMAINS. FEEL LIKELY COVERAGE IS WARRANTED BY AFTERNOON ACROSS MUCH OF THE AREA. OVERALL...PERSISTENT EASTERLY FLOW PREVAILS AS ATMOSPHERE BECOMES SATURATED. OPERATIONAL MODELS STILL SHOW PRECIPITABLE WATERS OF 150 TO 175 PERCENT ABOVE NORMAL AS THE DAY PROGRESSES. WEAK LIFT EMBEDDED IN THE MID LEVELS...ALONG WITH INCREASING ISENTROPIC LIFT WILL RESULT IN SHOWERS TODAY...POSSIBLE THUNDER...AND PLENTY OF CLOUDS. MOIST MARINE AIR WILL KEEP TEMPS IN THE 60S...WITH A MOS BLEND FOLLOWED. LEANED TOWARD COOLER MET MOS WHERE APPROPRIATE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... MODELS STILL DIFFER THIS TIME FRAME ON SUBTLE FEATURES. 00Z NAM SOLUTION WAS DISCARDED FOR THIS FORECAST. 00Z NAM FORECASTS A DEEPER MID LEVEL LOW...AND TRACKS THE SFC LOW FROM THE WESTERN ATLANTIC TO JUST EAST OF MONTAUK POINT LATE TONIGHT/EARLY TUESDAY. QUICK LOOK AT 06Z NAM...THE LOW HAS SHIFTED EAST CLOSER TO OTHER MODEL SOLUTIONS. IT IS IMPORTANT TO NOTE THAT THIS WAVE IS NOT ALBERTO. PLEASE SEE THE LATEST ADVISORIES REGARDING ALBERTO FROM THE NATIONAL HURRICANE CENTER. REFER TO NHC FOR THE LATEST ADVISORIES...TRACK FORECASTS AND DISCUSSIONS REGARDING ALBERTO. ANYWAY...LEANED TOWARD A SREF/ECMWF SOLUTIONS WITH REGARD TO THE FORECAST WITH A SLIGHTLY WEAKER AND FURTHER EAST LOW FOR LATE TONIGHT/EARLY TUESDAY. BY TUESDAY...THIS WAVE MOVES TO THE NORTHEAST AS A GENERAL WEAK TROUGH APPROACHES FROM THE WEST. LIKELY POPS EARLY TONIGHT...THEN COVERAGE BECAUSE MORE SCATTERED IN NATURE AS MID LEVEL FORCING MOVES NORTHEAST. WILL CAP POPS IN THE CHANCE RANGE TUESDAY...WITH SLIGHTLY HIGHER POPS OVER WESTERN SECTIONS CLOSER TO THE TROUGH. COULD BE JUST ENOUGH INSTABILITY ALOFT FOR THUNDER...MAINLY NW INTERIOR. BACKING UP A BIT...IF 00Z NAM PROVES TO BE CORRECT...HEAVIER RAIN WILL MOVE ACROSS EASTERN HALF OF THE CWA LATE TONIGHT/EARLY TUESDAY...BUT AGAIN THIS SOLUTION HAS BEEN DISCARDED AT THIS TIME. TEMPERATURES DO NOT FALL MUCH TONIGHT DUE TO CLOUDS AND ONSHORE FLOW. IF ANY SUN BREAKS OUT TUESDAY...ESPECIALLY WEST...TEMPS COULD REBOUND NICELY...AND FORECAST IS UNDERDONE. THINKING AROUND 70 NEAR THE COAST...AND MIDDLE TO UPPER 70S WEST FOR HIGHS TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... MODELS IN DECENT AGREEMENT WITH LONG-TERM OUTLOOK. COLD FRONT MOVES THROUGH THE REGION WEDNESDAY AFTERNOON...THEN BECOMES NEARLY STATIONARY EAST OF THE AREA. SEVERAL UPPER LEVEL DISTURBANCES MOVE ACROSS THE REGION THURSDAY THROUGH FRIDAY...FOLLOWED BY ANOTHER COLD FRONT LATE FRIDAY. T.S. ALBERTO IS NOT EXPECTED DIRECTLY IMPACT ON THE REGION...EXCEPT FOR LONG PERIOD SWELLS INCREASING SURF AT AREA BEACHES. REFER TO THE LATEST FORECASTS FROM THE NATIONAL HURRICANE CENTER FOR THE LATEST INFORMATION ON ALBERTO. WITH PERSISTENT ONSHORE FLOW...WARM AND HUMID AIRMASS REMAINS OVER THE AREA TUESDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT. ANY LINGERING SHOWERS TAPER OFF IN THE EVENING...THEN AREAS OF FOG DEVELOP AFTER MIDNIGHT...WITH LOCALLY DENSE FOG POSSIBLE IN THE OUTLYING AREAS. FOG SHOULD BURN OFF THROUGH WEDNESDAY MORNING. COLD FRONT THEN MOVES ACROSS THE AREA THROUGHOUT THE DAY. MODEL QPF INDICATING BEST CHANCES FOR PRECIP WILL BE OVER WESTERN ZONES...AS THE FRONT SEEMS TO WASH OUT AS IT MOVES THROUGH THE REGION. WILL CARRY HIGHEST POPS OVER WESTERN ZONES...WITH LOW CHANCE POPS OUT EAST IN THE AFTERNOON. HIGHS WEDNESDAY TOP OFF IN THE UPPER 70S TO LOWER 80S DESPITE THE CLOUDS/MORNING FOG. WEDNESDAY NIGHT...A CUTOFF H5 LOW BECOMES NEARLY STATIONARY OVER THE MID-ATLANTIC AREA AND WILL GRADUALLY TRACK NORTH THROUGH THE END OF THE WEEK. THAT LOW FINALLY DEPARTS FRIDAY NIGHT. DURING THIS TIME...ISOLATED TO SCATTERED SHOWERS WILL DEVELOP AS SEVERAL WEAK SHORTWAVES SPIN OFF THAT LOW. ONSHORE FLOW WILL USHER A MILD AIRMASS INTO THE REGION...KEEPING TEMPS IN THE 70S DESPITE CLOUD COVER. THESE TEMPS WILL BE ABOVE NORMAL THROUGH THE PERIOD. NEXT COLD FRONT APPROACHES ON SATURDAY AND WILL MOVE THROUGH THE REGION SATURDAY NIGHT. HIGH PRES RETURNS ON SUNDAY. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... WEAK LOW PRESSURE DRIFTS NORTHWARD ALONG THE EASTERN SEABOARD THROUGH TODAY. A LARGER LOW APPROACHES BY TONIGHT BUT STAYS WELL OFFSHORE. MOST TERMINALS IFR RANGE WITH SOME IN LIFR WITH RESPECT TO CIGS AND MORE VARIABLE WITH VSBYS. LOW CHANCE OF ANY IMPROVEMENT. EXPECTING IFR AT BEST THIS AFTERNOON. SHOWERS ARE PERIODIC TODAY BUT TRIED TO INDICATE A LULL BY INCREASING VSBYS IN THE AFTERNOON. CONDITIONS EXPECTED DROP BACK DOWN TO AT LEAST IFR AND LOWER IN SPOTS WITH RAIN/FOG TONIGHT. VSBYS WITHIN SHOWERS COULD VARY BY A FEW MILES FROM FORECAST. FORECAST HAS VSBYS LOWERING TO MVFR WITH THE SHOWERS FOR TODAY. NE-E WINDS IN THE TAF PERIOD NEAR OR BELOW 10 KT....TURNING MORE SOUTHEASTERLY ON TUESDAY. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR VARYING CEILINGS AND VSBYS IN HEAVIER SHOWERS AND POSSIBLE THUNDER. KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR VARYING CEILINGS AND VSBYS IN HEAVIER SHOWERS AND THUNDER. KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR VARYING CEILINGS AND VSBYS IN HEAVIER SHOWERS. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. .OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY... .TUESDAY-WEDNESDAY...MVFR WITH IFR POSSIBLE. ISOLATED THUNDERSTORM WEST OF THE HUDSON TUESDAY AFTERNOON. FOG POSSIBLE TUESDAY NIGHT. .THURSDAY AND FRIDAY...MAINLY VFR...BUT MVFR OR IFR POSSIBLE IN SHOWERS ON FRIDAY. && .MARINE... UPDATED FOR WEATHER THIS MORNING TO INCLUDE FOG AND DRIZZLE ACROSS THE FORECAST WATERS. SMALL CRAFT ADVISORY REMAINS UP FOR SEAS ACROSS THE OCEAN WATERS...DUE TO THE COMBINATION OF A PERSISTENT EASTERLY FETCH AND SWELL. THESE HIGHER SEAS CONTINUE THROUGH TUESDAY. FOR THE HARBORS/BAYS AND SOUND...SUB SCA CONDITIONS CONTINUE. A PERSISTENT ONSHORE FLOW SHOULD MAINTAIN SEAS AT SCA LEVELS OVER THE COASTAL OCEAN WATERS THROUGH WEDNESDAY...BUT SEAS SHOULD BEGIN TO SUBSIDE WEDNESDAY NIGHT AS SWELLS DEPART. LIGHT SOUTHERLY FLOW ON TAP INTO NEXT WEEKEND WILL KEEP CONDS BELOW SCA CRITERIA. && .HYDROLOGY... OVERALL...EXPECT ABOUT A HALF AN INCH TO THREE QUARTERS OF ANY INCH ON AVERAGE FOR SCATTERED TO NUMEROUS SHOWERS TODAY THROUGH TUESDAY. SOME AREAS MAY OBSERVE VERY LITTLE QPF...WHILE OTHER AREAS COULD RECEIVE IN EXCESS OF AN INCH...DEPENDING ON THE LOCATION OF ANY HEAVIER SHOWERS. AS SUCH...HIGHLY UNCERTAIN RAINFALL AMOUNTS FOR ANY PARTICULAR LOCATION CONTINUE. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT TUESDAY FOR ANZ350-353-355. && $$ SYNOPSIS...MPS/PW NEAR TERM...PW SHORT TERM...PW LONG TERM...MPS AVIATION...IRD MARINE...MPS/PW HYDROLOGY...PW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
851 AM EDT MON MAY 21 2012 .SYNOPSIS... A SERIES OF LOW PRESSURE SYSTEMS WILL IMPACT THE AREA THROUGH TUESDAY. A COLD FRONT MOVES THROUGH THE REGION ON WEDNESDAY... FOLLOWED BY ANOTHER COLD FRONT ON SATURDAY. HIGH PRESSURE RETURNS THEREAFTER. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LOW CLOUDS AND FOG DEVELOPED ACROSS THE COASTAL SECTIONS...WITH PATCHY DRIZZLE...EARLY THIS MORNING. VISIBILITIES HAVE LOWERED QUICKLY. UPDATED TO INCLUDE THE FOG AND DRIZZLE THIS MORNING. WILL CONFINE SHOWERS TO NYC AND AREAS JUST TO THE WEST OF THE CITY FOR SEVERAL HOURS THIS MORNING...THEN SHOWERS INCREASE IN COVERAGE SLOWLY FROM SW TO NE. THIS REFLECTS WELL IN THE HRRR AND RAP IN THE NEAR TERM. COULD TAKE SOMETIME FOR INTERIOR ZONES TO SEE PRECIP AS ENOUGH DRY AIR REMAINS. FEEL LIKELY COVERAGE IS WARRANTED BY AFTERNOON ACROSS MUCH OF THE AREA. OVERALL...PERSISTENT EASTERLY FLOW PREVAILS AS ATMOSPHERE BECOMES SATURATED. OPERATIONAL MODELS STILL SHOW PRECIPITABLE WATERS OF 150 TO 175 PERCENT ABOVE NORMAL AS THE DAY PROGRESSES. WEAK LIFT EMBEDDED IN THE MID LEVELS...ALONG WITH INCREASING ISENTROPIC LIFT WILL RESULT IN SHOWERS TODAY...POSSIBLE THUNDER...AND PLENTY OF CLOUDS. MOIST MARINE AIR WILL KEEP TEMPS IN THE 60S...WITH A MOS BLEND FOLLOWED. LEANED TOWARD COOLER MET MOS WHERE APPROPRIATE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... MODELS STILL DIFFER THIS TIME FRAME ON SUBTLE FEATURES. 00Z NAM SOLUTION WAS DISCARDED FOR THIS FORECAST. 00Z NAM FORECASTS A DEEPER MID LEVEL LOW...AND TRACKS THE SFC LOW FROM THE WESTERN ATLANTIC TO JUST EAST OF MONTAUK POINT LATE TONIGHT/EARLY TUESDAY. QUICK LOOK AT 06Z NAM...THE LOW HAS SHIFTED EAST CLOSER TO OTHER MODEL SOLUTIONS. IT IS IMPORTANT TO NOTE THAT THIS WAVE IS NOT ALBERTO. PLEASE SEE THE LATEST ADVISORIES REGARDING ALBERTO FROM THE NATIONAL HURRICANE CENTER. REFER TO NHC FOR THE LATEST ADVISORIES...TRACK FORECASTS AND DISCUSSIONS REGARDING ALBERTO. ANYWAY...LEANED TOWARD A SREF/ECMWF SOLUTIONS WITH REGARD TO THE FORECAST WITH A SLIGHTLY WEAKER AND FURTHER EAST LOW FOR LATE TONIGHT/EARLY TUESDAY. BY TUESDAY...THIS WAVE MOVES TO THE NORTHEAST AS A GENERAL WEAK TROUGH APPROACHES FROM THE WEST. LIKELY POPS EARLY TONIGHT...THEN COVERAGE BECAUSE MORE SCATTERED IN NATURE AS MID LEVEL FORCING MOVES NORTHEAST. WILL CAP POPS IN THE CHANCE RANGE TUESDAY...WITH SLIGHTLY HIGHER POPS OVER WESTERN SECTIONS CLOSER TO THE TROUGH. COULD BE JUST ENOUGH INSTABILITY ALOFT FOR THUNDER...MAINLY NW INTERIOR. BACKING UP A BIT...IF 00Z NAM PROVES TO BE CORRECT...HEAVIER RAIN WILL MOVE ACROSS EASTERN HALF OF THE CWA LATE TONIGHT/EARLY TUESDAY...BUT AGAIN THIS SOLUTION HAS BEEN DISCARDED AT THIS TIME. TEMPERATURES DO NOT FALL MUCH TONIGHT DUE TO CLOUDS AND ONSHORE FLOW. IF ANY SUN BREAKS OUT TUESDAY...ESPECIALLY WEST...TEMPS COULD REBOUND NICELY...AND FORECAST IS UNDERDONE. THINKING AROUND 70 NEAR THE COAST...AND MIDDLE TO UPPER 70S WEST FOR HIGHS TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... MODELS IN DECENT AGREEMENT WITH LONG-TERM OUTLOOK. COLD FRONT MOVES THROUGH THE REGION WEDNESDAY AFTERNOON...THEN BECOMES NEARLY STATIONARY EAST OF THE AREA. SEVERAL UPPER LEVEL DISTURBANCES MOVE ACROSS THE REGION THURSDAY THROUGH FRIDAY...FOLLOWED BY ANOTHER COLD FRONT LATE FRIDAY. T.S. ALBERTO IS NOT EXPECTED DIRECTLY IMPACT ON THE REGION...EXCEPT FOR LONG PERIOD SWELLS INCREASING SURF AT AREA BEACHES. REFER TO THE LATEST FORECASTS FROM THE NATIONAL HURRICANE CENTER FOR THE LATEST INFORMATION ON ALBERTO. WITH PERSISTENT ONSHORE FLOW...WARM AND HUMID AIRMASS REMAINS OVER THE AREA TUESDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT. ANY LINGERING SHOWERS TAPER OFF IN THE EVENING...THEN AREAS OF FOG DEVELOP AFTER MIDNIGHT...WITH LOCALLY DENSE FOG POSSIBLE IN THE OUTLYING AREAS. FOG SHOULD BURN OFF THROUGH WEDNESDAY MORNING. COLD FRONT THEN MOVES ACROSS THE AREA THROUGHOUT THE DAY. MODEL QPF INDICATING BEST CHANCES FOR PRECIP WILL BE OVER WESTERN ZONES...AS THE FRONT SEEMS TO WASH OUT AS IT MOVES THROUGH THE REGION. WILL CARRY HIGHEST POPS OVER WESTERN ZONES...WITH LOW CHANCE POPS OUT EAST IN THE AFTERNOON. HIGHS WEDNESDAY TOP OFF IN THE UPPER 70S TO LOWER 80S DESPITE THE CLOUDS/MORNING FOG. WEDNESDAY NIGHT...A CUTOFF H5 LOW BECOMES NEARLY STATIONARY OVER THE MID-ATLANTIC AREA AND WILL GRADUALLY TRACK NORTH THROUGH THE END OF THE WEEK. THAT LOW FINALLY DEPARTS FRIDAY NIGHT. DURING THIS TIME...ISOLATED TO SCATTERED SHOWERS WILL DEVELOP AS SEVERAL WEAK SHORTWAVES SPIN OFF THAT LOW. ONSHORE FLOW WILL USHER A MILD AIRMASS INTO THE REGION...KEEPING TEMPS IN THE 70S DESPITE CLOUD COVER. THESE TEMPS WILL BE ABOVE NORMAL THROUGH THE PERIOD. NEXT COLD FRONT APPROACHES ON SATURDAY AND WILL MOVE THROUGH THE REGION SATURDAY NIGHT. HIGH PRES RETURNS ON SUNDAY. && .AVIATION /13Z MONDAY THROUGH FRIDAY/... WEAK LOW PRESSURE DRIFTS NORTHWARD ALONG THE EASTERN SEABOARD THROUGH TODAY. A LARGER LOW APPROACHES BY TONIGHT BUT STAYS WELL OFFSHORE. MOST TERMINALS IFR RANGE WITH SOME IN LIFR WITH RESPECT TO CIGS AND MORE VARIABLE WITH VSBYS. LOW CHANCE OF ANY IMPROVEMENT. EXPECTING IFR AT BEST THIS AFTERNOON. SHOWERS ARE PERIODIC TODAY BUT TRIED TO INDICATE A LULL BY INCREASING VSBYS IN THE AFTERNOON. CONDITIONS EXPECTED DROP BACK DOWN TO AT LEAST IFR AND LOWER IN SPOTS WITH RAIN/FOG TONIGHT. VSBYS WITHIN SHOWERS COULD VARY BY A FEW MILES FROM FORECAST. FORECAST HAS VSBYS LOWERING TO MVFR WITH THE SHOWERS FOR TODAY. NE-E WINDS IN THE TAF PERIOD NEAR OR BELOW 10 KT....TURNING MORE SOUTHEASTERLY ON TUESDAY. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: A BRIEF THUNDERSTORM POSSIBLE BEFORE 13Z. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. LIFR COULD LAST LONGER THAN FORECAST. KEWR FCSTER COMMENTS: A BRIEF THUNDERSTORM POSSIBLE BEFORE 13Z. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. LIFR CIGS COULD LAST LONGER THAN FORECAST. .OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY... .TUESDAY-WEDNESDAY...MVFR WITH IFR POSSIBLE. ISOLATED THUNDERSTORM WEST OF THE HUDSON TUESDAY AFTERNOON. FOG POSSIBLE TUESDAY NIGHT. .THURSDAY AND FRIDAY...MAINLY VFR...BUT MVFR OR IFR POSSIBLE IN SHOWERS ON FRIDAY. && .MARINE... UPDATED FOR WEATHER THIS MORNING TO INCLUDE FOG AND DRIZZLE ACROSS THE FORECAST WATERS. SMALL CRAFT ADVISORY REMAINS UP FOR SEAS ACROSS THE OCEAN WATERS...DUE TO THE COMBINATION OF A PERSISTENT EASTERLY FETCH AND SWELL. THESE HIGHER SEAS CONTINUE THROUGH TUESDAY. FOR THE HARBORS/BAYS AND SOUND...SUB SCA CONDITIONS CONTINUE. A PERSISTENT ONSHORE FLOW SHOULD MAINTAIN SEAS AT SCA LEVELS OVER THE COASTAL OCEAN WATERS THROUGH WEDNESDAY...BUT SEAS SHOULD BEGIN TO SUBSIDE WEDNESDAY NIGHT AS SWELLS DEPART. LIGHT SOUTHERLY FLOW ON TAP INTO NEXT WEEKEND WILL KEEP CONDS BELOW SCA CRITERIA. && .HYDROLOGY... OVERALL...EXPECT ABOUT A HALF AN INCH TO THREE QUARTERS OF ANY INCH ON AVERAGE FOR SCATTERED TO NUMEROUS SHOWERS TODAY THROUGH TUESDAY. SOME AREAS MAY OBSERVE VERY LITTLE QPF...WHILE OTHER AREAS COULD RECEIVE IN EXCESS OF AN INCH...DEPENDING ON THE LOCATION OF ANY HEAVIER SHOWERS. AS SUCH...HIGHLY UNCERTAIN RAINFALL AMOUNTS FOR ANY PARTICULAR LOCATION CONTINUE. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT TUESDAY FOR ANZ350-353-355. && $$
AREA FORECAST DISCUSSION
NWS NEW YORK NY
759 AM EDT MON MAY 21 2012 .SYNOPSIS... A SERIES OF LOW PRESSURE SYSTEMS WILL IMPACT THE AREA THROUGH TUESDAY. A COLD FRONT MOVES THROUGH THE REGION ON WEDNESDAY... FOLLOWED BY ANOTHER COLD FRONT ON SATURDAY. HIGH PRESSURE RETURNS THEREAFTER. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WILL CONFINE SHOWERS TO NYC AND AREAS JUST TO THE WEST OF THE CITY FOR SEVERAL HOURS THIS MORNING...THEN SHOWERS INCREASE IN COVERAGE SLOWLY FROM SW TO NE. THIS REFLECTS WELL IN THE HRRR AND RAP IN THE NEAR TERM. COULD TAKE SOMETIME FOR INTERIOR ZONES TO SEE PRECIP AS ENOUGH DRY AIR REMAINS. FEEL LIKELY COVERAGE IS WARRANTED BY AFTERNOON ACROSS MUCH OF THE AREA. OVERALL...PERSISTENT EASTERLY FLOW PREVAILS AS ATMOSPHERE BECOMES SATURATED. OPERATIONAL MODELS STILL SHOW PRECIPITABLE WATERS OF 150 TO 175 PERCENT ABOVE NORMAL AS THE DAY PROGRESSES. WEAK LIFT EMBEDDED IN THE MID LEVELS...ALONG WITH INCREASING ISENTROPIC LIFT WILL RESULT IN SHOWERS TODAY...POSSIBLE THUNDER...AND PLENTY OF CLOUDS. MOIST MARINE AIR WILL KEEP TEMPS IN THE 60S...WITH A MOS BLEND FOLLOWED. LEANED TOWARD COOLER MET MOS WHERE APPROPRIATE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... MODELS STILL DIFFER THIS TIME FRAME ON SUBTLE FEATURES. 00Z NAM SOLUTION WAS DISCARDED FOR THIS FORECAST. 00Z NAM FORECASTS A DEEPER MID LEVEL LOW...AND TRACKS THE SFC LOW FROM THE WESTERN ATLANTIC TO JUST EAST OF MONTAUK POINT LATE TONIGHT/EARLY TUESDAY. QUICK LOOK AT 06Z NAM...THE LOW HAS SHIFTED EAST CLOSER TO OTHER MODEL SOLUTIONS. IT IS IMPORTANT TO NOTE THAT THIS WAVE IS NOT ALBERTO. PLEASE SEE THE LATEST ADVISORIES REGARDING ALBERTO FROM THE NATIONAL HURRICANE CENTER. REFER TO NHC FOR THE LATEST ADVISORIES...TRACK FORECASTS AND DISCUSSIONS REGARDING ALBERTO. ANYWAY...LEANED TOWARD A SREF/ECMWF SOLUTIONS WITH REGARD TO THE FORECAST WITH A SLIGHTLY WEAKER AND FURTHER EAST LOW FOR LATE TONIGHT/EARLY TUESDAY. BY TUESDAY...THIS WAVE MOVES TO THE NORTHEAST AS A GENERAL WEAK TROUGH APPROACHES FROM THE WEST. LIKELY POPS EARLY TONIGHT...THEN COVERAGE BECAUSE MORE SCATTERED IN NATURE AS MID LEVEL FORCING MOVES NORTHEAST. WILL CAP POPS IN THE CHANCE RANGE TUESDAY...WITH SLIGHTLY HIGHER POPS OVER WESTERN SECTIONS CLOSER TO THE TROUGH. COULD BE JUST ENOUGH INSTABILITY ALOFT FOR THUNDER...MAINLY NW INTERIOR. BACKING UP A BIT...IF 00Z NAM PROVES TO BE CORRECT...HEAVIER RAIN WILL MOVE ACROSS EASTERN HALF OF THE CWA LATE TONIGHT/EARLY TUESDAY...BUT AGAIN THIS SOLUTION HAS BEEN DISCARDED AT THIS TIME. TEMPERATURES DO NOT FALL MUCH TONIGHT DUE TO CLOUDS AND ONSHORE FLOW. IF ANY SUN BREAKS OUT TUESDAY...ESPECIALLY WEST...TEMPS COULD REBOUND NICELY...AND FORECAST IS UNDERDONE. THINKING AROUND 70 NEAR THE COAST...AND MIDDLE TO UPPER 70S WEST FOR HIGHS TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... MODELS IN DECENT AGREEMENT WITH LONG-TERM OUTLOOK. COLD FRONT MOVES THROUGH THE REGION WEDNESDAY AFTERNOON...THEN BECOMES NEARLY STATIONARY EAST OF THE AREA. SEVERAL UPPER LEVEL DISTURBANCES MOVE ACROSS THE REGION THURSDAY THROUGH FRIDAY...FOLLOWED BY ANOTHER COLD FRONT LATE FRIDAY. T.S. ALBERTO IS NOT EXPECTED DIRECTLY IMPACT ON THE REGION...EXCEPT FOR LONG PERIOD SWELLS INCREASING SURF AT AREA BEACHES. REFER TO THE LATEST FORECASTS FROM THE NATIONAL HURRICANE CENTER FOR THE LATEST INFORMATION ON ALBERTO. WITH PERSISTENT ONSHORE FLOW...WARM AND HUMID AIRMASS REMAINS OVER THE AREA TUESDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT. ANY LINGERING SHOWERS TAPER OFF IN THE EVENING...THEN AREAS OF FOG DEVELOP AFTER MIDNIGHT...WITH LOCALLY DENSE FOG POSSIBLE IN THE OUTLYING AREAS. FOG SHOULD BURN OFF THROUGH WEDNESDAY MORNING. COLD FRONT THEN MOVES ACROSS THE AREA THROUGHOUT THE DAY. MODEL QPF INDICATING BEST CHANCES FOR PRECIP WILL BE OVER WESTERN ZONES...AS THE FRONT SEEMS TO WASH OUT AS IT MOVES THROUGH THE REGION. WILL CARRY HIGHEST POPS OVER WESTERN ZONES...WITH LOW CHANCE POPS OUT EAST IN THE AFTERNOON. HIGHS WEDNESDAY TOP OFF IN THE UPPER 70S TO LOWER 80S DESPITE THE CLOUDS/MORNING FOG. WEDNESDAY NIGHT...A CUTOFF H5 LOW BECOMES NEARLY STATIONARY OVER THE MID-ATLANTIC AREA AND WILL GRADUALLY TRACK NORTH THROUGH THE END OF THE WEEK. THAT LOW FINALLY DEPARTS FRIDAY NIGHT. DURING THIS TIME...ISOLATED TO SCATTERED SHOWERS WILL DEVELOP AS SEVERAL WEAK SHORTWAVES SPIN OFF THAT LOW. ONSHORE FLOW WILL USHER A MILD AIRMASS INTO THE REGION...KEEPING TEMPS IN THE 70S DESPITE CLOUD COVER. THESE TEMPS WILL BE ABOVE NORMAL THROUGH THE PERIOD. NEXT COLD FRONT APPROACHES ON SATURDAY AND WILL MOVE THROUGH THE REGION SATURDAY NIGHT. HIGH PRES RETURNS ON SUNDAY. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... WEAK LOW PRESSURE DRIFTS NORTHWARD ALONG THE EASTERN SEABOARD THROUGH TODAY. A LARGER LOW APPROACHES BY TONIGHT BUT STAYS WELL OFFSHORE. MOST TERMINALS IFR RANGE WITH SOME IN LIFR WITH RESPECT TO CIGS AND MORE VARIABLE WITH VSBYS. LOW CHANCE OF ANY IMPROVEMENT. EXPECTING IFR AT BEST THIS AFTERNOON. SHOWERS ARE PERIODIC TODAY BUT TRIED TO INDICATE A LULL BY INCREASING VSBYS IN THE AFTERNOON. CONDITIONS EXPECTED DROP BACK DOWN TO AT LEAST IFR AND LOWER IN SPOTS WITH RAIN/FOG TONIGHT. VSBYS WITHIN SHOWERS COULD VARY BY A FEW MILES FROM FORECAST. FORECAST HAS VSBYS LOWERING TO MVFR WITH THE SHOWERS FOR TODAY. NE-E WINDS IN THE TAF PERIOD NEAR OR BELOW 10 KT....TURNING MORE SOUTHEASTERLY ON TUESDAY. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: A BRIEF THUNDERSTORM POSSIBLE BEFORE 13Z. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. LIFR COULD LAST LONGER THAN FORECAST. KEWR FCSTER COMMENTS: A BRIEF THUNDERSTORM POSSIBLE BEFORE 13Z. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. LIFR CIGS COULD LAST LONGER THAN FORECAST. .OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY... .TUESDAY-WEDNESDAY...MVFR WITH IFR POSSIBLE. ISOLATED THUNDERSTORM WEST OF THE HUDSON TUESDAY AFTERNOON. FOG POSSIBLE TUESDAY NIGHT. .THURSDAY AND FRIDAY...MAINLY VFR...BUT MVFR OR IFR POSSIBLE IN SHOWERS ON FRIDAY. && .MARINE... SMALL CRAFT ADVISORY REMAINS UP FOR SEAS ACROSS THE OCEAN WATERS...DUE TO THE COMBINATION OF A PERSISTENT EASTERLY FETCH AND SWELL. THESE HIGHER SEAS CONTINUE THROUGH TUESDAY. FOR THE HARBORS/BAYS AND SOUND...SUB SCA CONDITIONS CONTINUE. A PERSISTENT ONSHORE FLOW SHOULD MAINTAIN SEAS AT SCA LEVELS OVER THE COASTAL OCEAN WATERS THROUGH WEDNESDAY...BUT SEAS SHOULD BEGIN TO SUBSIDE WEDNESDAY NIGHT AS SWELLS DEPART. LIGHT SOUTHERLY FLOW ON TAP INTO NEXT WEEKEND WILL KEEP CONDS BELOW SCA CRITERIA. && .HYDROLOGY... OVERALL...EXPECT ABOUT A HALF AN INCH TO THREE QUARTERS OF ANY INCH ON AVERAGE FOR SCATTERED TO NUMEROUS SHOWERS TODAY THROUGH TUESDAY. SOME AREAS MAY OBSERVE VERY LITTLE QPF...WHILE OTHER AREAS COULD RECEIVE IN EXCESS OF AN INCH...DEPENDING ON THE LOCATION OF ANY HEAVIER SHOWERS. AS SUCH...HIGHLY UNCERTAIN RAINFALL AMOUNTS FOR ANY PARTICULAR LOCATION CONTINUE. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT TUESDAY FOR ANZ350-353-355. && $$ SYNOPSIS...MPS/PW NEAR TERM...PW SHORT TERM...PW LONG TERM...MPS AVIATION...JM MARINE...MPS/PW HYDROLOGY...PW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
714 AM EDT MON MAY 21 2012 .SYNOPSIS... A SERIES OF LOW PRESSURE SYSTEMS WILL IMPACT THE AREA THROUGH TUESDAY. A COLD FRONT MOVES THROUGH THE REGION ON WEDNESDAY... FOLLOWED BY ANOTHER COLD FRONT ON SATURDAY. HIGH PRESSURE RETURNS THEREAFTER. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WILL CONFINE SHOWERS TO NYC AND AREAS JUST TO THE WEST OF THE CITY FOR SEVERAL HOURS THIS MORNING...THEN SHOWERS INCREASE IN COVERAGE SLOWLY FROM SW TO NE. THIS REFLECTS WELL IN THE HRRR AND RAP IN THE NEAR TERM. COULD TAKE SOMETIME FOR INTERIOR ZONES TO SEE PRECIP AS ENOUGH DRY AIR REMAINS. FEEL LIKELY COVERAGE IS WARRANTED BY AFTERNOON ACROSS MUCH OF THE AREA. OVERALL...PERSISTENT EASTERLY FLOW PREVAILS AS ATMOSPHERE BECOMES SATURATED. OPERATIONAL MODELS STILL SHOW PRECIPITABLE WATERS OF 150 TO 175 PERCENT ABOVE NORMAL AS THE DAY PROGRESSES. WEAK LIFT EMBEDDED IN THE MID LEVELS...ALONG WITH INCREASING ISENTROPIC LIFT WILL RESULT IN SHOWERS TODAY...POSSIBLE THUNDER...AND PLENTY OF CLOUDS. MOIST MARINE AIR WILL KEEP TEMPS IN THE 60S...WITH A MOS BLEND FOLLOWED. LEANED TOWARD COOLER MET MOS WHERE APPROPRIATE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... MODELS STILL DIFFER THIS TIME FRAME ON SUBTLE FEATURES. 00Z NAM SOLUTION WAS DISCARDED FOR THIS FORECAST. 00Z NAM FORECASTS A DEEPER MID LEVEL LOW...AND TRACKS THE SFC LOW FROM THE WESTERN ATLANTIC TO JUST EAST OF MONTAUK POINT LATE TONIGHT/EARLY TUESDAY. QUICK LOOK AT 06Z NAM...THE LOW HAS SHIFTED EAST CLOSER TO OTHER MODEL SOLUTIONS. IT IS IMPORTANT TO NOTE THAT THIS WAVE IS NOT ALBERTO. PLEASE SEE THE LATEST ADVISORIES REGARDING ALBERTO FROM THE NATIONAL HURRICANE CENTER. REFER TO NHC FOR THE LATEST ADVISORIES...TRACK FORECASTS AND DISCUSSIONS REGARDING ALBERTO. ANYWAY...LEANED TOWARD A SREF/ECMWF SOLUTIONS WITH REGARD TO THE FORECAST WITH A SLIGHTLY WEAKER AND FURTHER EAST LOW FOR LATE TONIGHT/EARLY TUESDAY. BY TUESDAY...THIS WAVE MOVES TO THE NORTHEAST AS A GENERAL WEAK TROUGH APPROACHES FROM THE WEST. LIKELY POPS EARLY TONIGHT...THEN COVERAGE BECAUSE MORE SCATTERED IN NATURE AS MID LEVEL FORCING MOVES NORTHEAST. WILL CAP POPS IN THE CHANCE RANGE TUESDAY...WITH SLIGHTLY HIGHER POPS OVER WESTERN SECTIONS CLOSER TO THE TROUGH. COULD BE JUST ENOUGH INSTABILITY ALOFT FOR THUNDER...MAINLY NW INTERIOR. BACKING UP A BIT...IF 00Z NAM PROVES TO BE CORRECT...HEAVIER RAIN WILL MOVE ACROSS EASTERN HALF OF THE CWA LATE TONIGHT/EARLY TUESDAY...BUT AGAIN THIS SOLUTION HAS BEEN DISCARDED AT THIS TIME. TEMPERATURES DO NOT FALL MUCH TONIGHT DUE TO CLOUDS AND ONSHORE FLOW. IF ANY SUN BREAKS OUT TUESDAY...ESPECIALLY WEST...TEMPS COULD REBOUND NICELY...AND FORECAST IS UNDERDONE. THINKING AROUND 70 NEAR THE COAST...AND MIDDLE TO UPPER 70S WEST FOR HIGHS TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... MODELS IN DECENT AGREEMENT WITH LONG-TERM OUTLOOK. COLD FRONT MOVES THROUGH THE REGION WEDNESDAY AFTERNOON...THEN BECOMES NEARLY STATIONARY EAST OF THE AREA. SEVERAL UPPER LEVEL DISTURBANCES MOVE ACROSS THE REGION THURSDAY THROUGH FRIDAY...FOLLOWED BY ANOTHER COLD FRONT LATE FRIDAY. T.S. ALBERTO IS NOT EXPECTED DIRECTLY IMPACT ON THE REGION...EXCEPT FOR LONG PERIOD SWELLS INCREASING SURF AT AREA BEACHES. REFER TO THE LATEST FORECASTS FROM THE NATIONAL HURRICANE CENTER FOR THE LATEST INFORMATION ON ALBERTO. WITH PERSISTENT ONSHORE FLOW...WARM AND HUMID AIRMASS REMAINS OVER THE AREA TUESDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT. ANY LINGERING SHOWERS TAPER OFF IN THE EVENING...THEN AREAS OF FOG DEVELOP AFTER MIDNIGHT...WITH LOCALLY DENSE FOG POSSIBLE IN THE OUTLYING AREAS. FOG SHOULD BURN OFF THROUGH WEDNESDAY MORNING. COLD FRONT THEN MOVES ACROSS THE AREA THROUGHOUT THE DAY. MODEL QPF INDICATING BEST CHANCES FOR PRECIP WILL BE OVER WESTERN ZONES...AS THE FRONT SEEMS TO WASH OUT AS IT MOVES THROUGH THE REGION. WILL CARRY HIGHEST POPS OVER WESTERN ZONES...WITH LOW CHANCE POPS OUT EAST IN THE AFTERNOON. HIGHS WEDNESDAY TOP OFF IN THE UPPER 70S TO LOWER 80S DESPITE THE CLOUDS/MORNING FOG. WEDNESDAY NIGHT...A CUTOFF H5 LOW BECOMES NEARLY STATIONARY OVER THE MID-ATLANTIC AREA AND WILL GRADUALLY TRACK NORTH THROUGH THE END OF THE WEEK. THAT LOW FINALLY DEPARTS FRIDAY NIGHT. DURING THIS TIME...ISOLATED TO SCATTERED SHOWERS WILL DEVELOP AS SEVERAL WEAK SHORTWAVES SPIN OFF THAT LOW. ONSHORE FLOW WILL USHER A MILD AIRMASS INTO THE REGION...KEEPING TEMPS IN THE 70S DESPITE CLOUD COVER. THESE TEMPS WILL BE ABOVE NORMAL THROUGH THE PERIOD. NEXT COLD FRONT APPROACHES ON SATURDAY AND WILL MOVE THROUGH THE REGION SATURDAY NIGHT. HIGH PRES RETURNS ON SUNDAY. && .AVIATION /11Z MONDAY THROUGH FRIDAY/... WEAK LOW PRESSURE DRIFTS NORTHWARD ALONG THE EASTERN SEABOARD THROUGH TODAY. A LARGER LOW APPROACHES BY TONIGHT BUT STAYS WELL OFFSHORE. CIGS OF MVFR TO IFR WILL TREND MORE IFR THIS MORNING AS SHOWER COVERAGE INCREASES. LOOKING FOR THIS TO STAY WITH A CHANCE OF IMPROVEMENT TO LOW END MVFR...1-2KFT IN THE AFTERNOON FOR SOME TERMINALS AWAY FROM THE COAST BUT THINK THIS IS QUITE LOW AT THE MOMENT. THEREFORE IFR CONTINUES IN THE TAFS WITH PERIODIC SHOWERS TODAY. VSBYS WITHIN SHOWERS COULD VARY BY A FEW MILES FROM FORECAST. FORECAST HAS VSBYS LOWERING TO MVFR WITH THE SHOWERS FOR TODAY. NE-E WINDS IN THE TAF PERIOD NEAR OR BELOW 10 KT. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. KEWR FCSTER COMMENTS: IFR CIGS COULD ARRIVE 1-2 HRS LATER THAN FORECAST. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: IFR CIGS COULD ARRIVE 1-2 HRS LATER THAN FORECAST. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. KHPN FCSTER COMMENTS: IFR CIGS COULD ARRIVE 1-2 HRS LATER THAN FORECAST. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. .OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY... .TONIGHT...MVFR OR IFR IN RAIN/FOG. LOWER CONDITIONS POSSIBLE. .TUESDAY-WEDNESDAY...MVFR WITH IFR POSSIBLE. ISOLATED THUNDERSTORM WEST OF THE HUDSON TUESDAY AFTERNOON. FOG POSSIBLE TUESDAY NIGHT. .THURSDAY AND FRIDAY...MAINLY VFR...BUT MVFR OR IFR POSSIBLE IN SHOWERS ON FRIDAY. && .MARINE... SMALL CRAFT ADVISORY REMAINS UP FOR SEAS ACROSS THE OCEAN WATERS...DUE TO THE COMBINATION OF A PERSISTENT EASTERLY FETCH AND SWELL. THESE HIGHER SEAS CONTINUE THROUGH TUESDAY. FOR THE HARBORS/BAYS AND SOUND...SUB SCA CONDITIONS CONTINUE. A PERSISTENT ONSHORE FLOW SHOULD MAINTAIN SEAS AT SCA LEVELS OVER THE COASTAL OCEAN WATERS THROUGH WEDNESDAY...BUT SEAS SHOULD BEGIN TO SUBSIDE WEDNESDAY NIGHT AS SWELLS DEPART. LIGHT SOUTHERLY FLOW ON TAP INTO NEXT WEEKEND WILL KEEP CONDS BELOW SCA CRITERIA. && .HYDROLOGY... OVERALL...EXPECT ABOUT A HALF AN INCH TO THREE QUARTERS OF ANY INCH ON AVERAGE FOR SCATTERED TO NUMEROUS SHOWERS TODAY THROUGH TUESDAY. SOME AREAS MAY OBSERVE VERY LITTLE QPF...WHILE OTHER AREAS COULD RECEIVE IN EXCESS OF AN INCH...DEPENDING ON THE LOCATION OF ANY HEAVIER SHOWERS. AS SUCH...HIGHLY UNCERTAIN RAINFALL AMOUNTS FOR ANY PARTICULAR LOCATION CONTINUE. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT TUESDAY FOR ANZ350-353-355. && $$ SYNOPSIS...MPS/PW NEAR TERM...PW SHORT TERM...PW LONG TERM...MPS AVIATION...JM MARINE...MPS/PW HYDROLOGY...PW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
554 AM EDT MON MAY 21 2012 .SYNOPSIS... A SERIES OF LOW PRESSURE SYSTEMS WILL IMPACT THE AREA THROUGH TUESDAY. A COLD FRONT MOVES THROUGH THE REGION ON WEDNESDAY...FOLLOWED BY ANOTHER COLD FRONT ON SATURDAY. HIGH PRESSURE RETURNS THEREAFTER. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... RADAR INDICATES MODERATE TO HEAVY SHOWERS MOVING FROM SOUTHEAST TO NORTHWEST...CLIPPING PORTIONS OF THE AREA NEAR STATEN ISLAND..AND ESSEX/UNION COUNTIES OF NJ. JUST ENOUGH INSTABILITY ALOFT TO WARRANT THUNDER MENTION...MAINLY WESTERN PORTIONS OF THE CWA. HRRR AND RAP IN THE NEAR TERM SHOWS SHOWER COVERAGE EVER SO SLOWLY INCREASES FROM THE SOUTH THIS MORNING. COULD TAKE SOMETIME FOR INTERIOR ZONES TO SEE PRECIP AS ENOUGH DRY AIR REMAINS. FEEL LIKELY COVERAGE IS WARRANTED BY AFTERNOON ACROSS MUCH OF THE AREA. OVERALL...PERSISTENT EASTERLY FLOW PREVAILS AS ATMOSPHERE BECOMES SATURATED. OPERATIONAL MODELS STILL SHOW PRECIPITABLE WATERS OF 150 TO 175 PERCENT ABOVE NORMAL AS THE DAY PROGRESSES. WEAK LIFT EMBEDDED IN THE MID LEVELS...ALONG WITH INCREASING ISENTROPIC LIFT WILL RESULT IN SHOWERS TODAY...POSSIBLE THUNDER...AND PLENTY OF CLOUDS. MOIST MARINE AIR WILL KEEP TEMPS IN THE 60S...WITH A MOS BLEND FOLLOWED. LEANED TOWARD COOLER MET MOS WHERE APPROPRIATE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... MODELS STILL DIFFER THIS TIME FRAME ON SUBTLE FEATURES. 00Z NAM SOLUTION WAS DISCARDED FOR THIS FORECAST. 00Z NAM FORECASTS A DEEPER MID LEVEL LOW...AND TRACKS THE SFC LOW FROM THE WESTERN ATLANTIC TO JUST EAST OF MONTAUK POINT LATE TONIGHT/EARLY TUESDAY. QUICK LOOK AT 06Z NAM...THE LOW HAS SHIFTED EAST CLOSER TO OTHER MODEL SOLUTIONS. IT IS IMPORTANT TO NOTE THAT THIS WAVE IS NOT ALBERTO. PLEASE SEE THE LATEST ADVISORIES REGARDING ALBERTO FROM THE NATIONAL HURRICANE CENTER. REFER TO NHC FOR THE LATEST ADVISORIES...TRACK FORECASTS AND DISCUSSIONS REGARDING ALBERTO. ANYWAY...LEANED TOWARD A SREF/ECMWF SOLUTIONS WITH REGARD TO THE FORECAST WITH A SLIGHTLY WEAKER AND FURTHER EAST LOW FOR LATE TONIGHT/EARLY TUESDAY. BY TUESDAY...THIS WAVE MOVES TO THE NORTHEAST AS A GENERAL WEAK TROUGH APPROACHES FROM THE WEST. LIKELY POPS EARLY TONIGHT...THEN COVERAGE BECAUSE MORE SCATTERED IN NATURE AS MID LEVEL FORCING MOVES NORTHEAST. WILL CAP POPS IN THE CHANCE RANGE TUESDAY...WITH SLIGHTLY HIGHER POPS OVER WESTERN SECTIONS CLOSER TO THE TROUGH. COULD BE JUST ENOUGH INSTABILITY ALOFT FOR THUNDER...MAINLY NW INTERIOR. BACKING UP A BIT...IF 00Z NAM PROVES TO BE CORRECT...HEAVIER RAIN WILL MOVE ACROSS EASTERN HALF OF THE CWA LATE TONIGHT/EARLY TUESDAY...BUT AGAIN THIS SOLUTION HAS BEEN DISCARDED AT THIS TIME. TEMPERATURES DO NOT FALL MUCH TONIGHT DUE TO CLOUDS AND ONSHORE FLOW. IF ANY SUN BREAKS OUT TUESDAY...ESPECIALLY WEST...TEMPS COULD REBOUND NICELY...AND FORECAST IS UNDERDONE. THINKING AROUND 70 NEAR THE COAST...AND MIDDLE TO UPPER 70S WEST FOR HIGHS TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... MODELS IN DECENT AGREEMENT WITH LONG-TERM OUTLOOK. COLD FRONT MOVES THROUGH THE REGION WEDNESDAY AFTERNOON...THEN BECOMES NEARLY STATIONARY EAST OF THE AREA. SEVERAL UPPER LEVEL DISTURBANCES MOVE ACROSS THE REGION THURSDAY THROUGH FRIDAY...FOLLOWED BY ANOTHER COLD FRONT LATE FRIDAY. T.S. ALBERTO IS NOT EXPECTED DIRECTLY IMPACT ON THE REGION...EXCEPT FOR LONG PERIOD SWELLS INCREASING SURF AT AREA BEACHES. REFER TO THE LATEST FORECASTS FROM THE NATIONAL HURRICANE CENTER FOR THE LATEST INFORMATION ON ALBERTO. WITH PERSISTENT ONSHORE FLOW...WARM AND HUMID AIRMASS REMAINS OVER THE AREA TUESDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT. ANY LINGERING SHOWERS TAPER OFF IN THE EVENING...THEN AREAS OF FOG DEVELOP AFTER MIDNIGHT...WITH LOCALLY DENSE FOG POSSIBLE IN THE OUTLYING AREAS. FOG SHOULD BURN OFF THROUGH WEDNESDAY MORNING. COLD FRONT THEN MOVES ACROSS THE AREA THROUGHOUT THE DAY. MODEL QPF INDICATING BEST CHANCES FOR PRECIP WILL BE OVER WESTERN ZONES...AS THE FRONT SEEMS TO WASH OUT AS IT MOVES THROUGH THE REGION. WILL CARRY HIGHEST POPS OVER WESTERN ZONES...WITH LOW CHANCE POPS OUT EAST IN THE AFTERNOON. HIGHS WEDNESDAY TOP OFF IN THE UPPER 70S TO LOWER 80S DESPITE THE CLOUDS/MORNING FOG. WEDNESDAY NIGHT...A CUTOFF H5 LOW BECOMES NEARLY STATIONARY OVER THE MID-ATLANTIC AREA AND WILL GRADUALLY TRACK NORTH THROUGH THE END OF THE WEEK. THAT LOW FINALLY DEPARTS FRIDAY NIGHT. DURING THIS TIME...ISOLATED TO SCATTERED SHOWERS WILL DEVELOP AS SEVERAL WEAK SHORTWAVES SPIN OFF THAT LOW. ONSHORE FLOW WILL USHER A MILD AIRMASS INTO THE REGION...KEEPING TEMPS IN THE 70S DESPITE CLOUD COVER. THESE TEMPS WILL BE ABOVE NORMAL THROUGH THE PERIOD. NEXT COLD FRONT APPROACHES ON SATURDAY AND WILL MOVE THROUGH THE REGION SATURDAY NIGHT. HIGH PRES RETURNS ON SUNDAY. && .AVIATION /10Z MONDAY THROUGH FRIDAY/... WEAK LOW PRESSURE DRIFTS NORTHWARD ALONG THE EASTERN SEABOARD THROUGH TODAY. A LARGER LOW APPROACHES BY TONIGHT BUT STAYS WELL OFFSHORE. CIGS OF MVFR TO IFR WILL TREND MORE IFR THIS MORNING AS SHOWER COVERAGE INCREASES. LOOKING FOR THIS TO STAY WITH A CHANCE OF IMPROVEMENT TO LOW END MVFR...1-2KFT IN THE AFTERNOON FOR SOME TERMINALS AWAY FROM THE COAST BUT THINK THIS IS QUITE LOW AT THE MOMENT. THEREFORE IFR CONTINUES IN THE TAFS WITH PERIODIC SHOWERS TODAY. VSBYS WITHIN SHOWERS COULD VARY BY A FEW MILES FROM FORECAST. FORECAST HAS VSBYS LOWERING TO MVFR WITH THE SHOWERS FOR TODAY. NE-E WINDS IN THE TAF PERIOD NEAR OR BELOW 10 KT. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. KEWR FCSTER COMMENTS: IFR CIGS COULD ARRIVE 1-2 HRS LATER THAN FORECAST. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: IFR CIGS COULD ARRIVE 1-2 HRS LATER THAN FORECAST. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. KHPN FCSTER COMMENTS: IFR CIGS COULD ARRIVE 1-2 HRS LATER THAN FORECAST. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. .OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY... .TONIGHT...MVFR OR IFR IN RAIN/FOG. LOWER CONDITIONS POSSIBLE. .TUESDAY-WEDNESDAY...MVFR WITH IFR POSSIBLE. ISOLATED THUNDERSTORM WEST OF THE HUDSON TUESDAY AFTERNOON. FOG POSSIBLE TUESDAY NIGHT. .THURSDAY AND FRIDAY...MAINLY VFR...BUT MVFR OR IFR POSSIBLE IN SHOWERS ON FRIDAY. && .MARINE... SMALL CRAFT ADVISORY REMAINS UP FOR SEAS ACROSS THE OCEAN WATERS...DUE TO THE COMBINATION OF A PERSISTENT EASTERLY FETCH AND SWELL. THESE HIGHER SEAS CONTINUE THROUGH TUESDAY. FOR THE HARBORS/BAYS AND SOUND...SUB SCA CONDITIONS CONTINUE. A PERSISTENT ONSHORE FLOW SHOULD MAINTAIN SEAS AT SCA LEVELS OVER THE COASTAL OCEAN WATERS THROUGH WEDNESDAY...BUT SEAS SHOULD BEGIN TO SUBSIDE WEDNESDAY NIGHT AS SWELLS DEPART. LIGHT SOUTHERLY FLOW ON TAP INTO NEXT WEEKEND WILL KEEP CONDS BELOW SCA CRITERIA. && .HYDROLOGY... OVERALL...EXPECT ABOUT A HALF AN INCH TO THREE QUARTERS OF ANY INCH ON AVERAGE FOR SCATTERED TO NUMEROUS SHOWERS TODAY THROUGH TUESDAY. SOME AREAS MAY OBSERVE VERY LITTLE QPF...WHILE OTHER AREAS COULD RECEIVE IN EXCESS OF AN INCH...DEPENDING ON THE LOCATION OF ANY HEAVIER SHOWERS. AS SUCH...HIGHLY UNCERTAIN RAINFALL AMOUNTS FOR ANY PARTICULAR LOCATION CONTINUE. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT TUESDAY FOR ANZ350-353-355. && $$ SYNOPSIS...MPS/PW NEAR TERM...PW SHORT TERM...PW LONG TERM...MPS AVIATION...JM MARINE...MPS/PW HYDROLOGY...PW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
511 AM EDT MON MAY 21 2012 .SYNOPSIS... A SERIES OF LOW PRESSURE SYSTEMS WILL IMPACT THE AREA THROUGH TUESDAY. A COLD FRONT MOVES THROUGH THE REGION ON WEDNESDAY...FOLLOWED BY ANOTHER COLD FRONT ON SATURDAY. HIGH PRESSURE RETURNS THEREAFTER. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... HRRR AND RAP IN THE NEAR TERM SHOWS SHOWER COVERAGE EVER SO SLOWLY INCREASES FROM THE SOUTH THIS MORNING. COULD TAKE SOMETIME FOR INTERIOR ZONES TO SEE PRECIP AS ENOUGH DRY AIR REMAINS. FEEL LIKELY COVERAGE IS WARRANTED BY AFTERNOON ACROSS MUCH OF THE AREA. OVERALL...PERSISTENT EASTERLY FLOW PREVAILS AS ATMOSPHERE BECOMES SATURATED. OPERATIONAL MODELS STILL SHOW PRECIPITABLE WATERS OF 150 TO 175 PERCENT ABOVE NORMAL AS THE DAY PROGRESSES. WEAK LIFT EMBEDDED IN THE MID LEVELS...ALONG WITH INCREASING ISENTROPIC LIFT WILL RESULT IN SHOWERS TODAY...AND PLENTY OF CLOUDS. MOIST MARINE AIR WILL KEEP TEMPS IN THE 60S...WITH A MOS BLEND FOLLOWED. LEANED TOWARD COOLER MET MOS WHERE APPROPRIATE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... MODELS STILL DIFFER THIS TIME FRAME ON SUBTLE FEATURES. NAM SOLUTION WAS DISCARDED FOR THIS FORECAST. NAM FORECASTS A DEEPER MID LEVEL LOW...AND TRACKS THE SFC LOW FROM THE WESTERN ATLANTIC TO JUST EAST OF MONTAUK POINT LATE TONIGHT/EARLY TUESDAY. IT IS IMPORTANT TO NOTE THAT THIS WAVE IS NOT ALBERTO. PLEASE SEE THE LATEST ADVISORIES REGARDING ALBERTO FROM THE NATIONAL HURRICANE CENTER. REFER TO NHC FOR THE LATEST ADVISORIES...TRACK FORECASTS AND DISCUSSIONS REGARDING ALBERTO. ANYWAY...LEANED TOWARD A SREF/ECMWF SOLUTIONS WITH REGARD TO THE FORECAST WITH A SLIGHTLY WEAKER AND FURTHER EAST LOW FOR LATE TONIGHT/EARLY TUESDAY. BY TUESDAY...THIS WAVE MOVES TO THE NORTHEAST AS A GENERAL WEAK TROUGH APPROACHES FROM THE WEST. LIKELY POPS EARLY TONIGHT...THEN COVERAGE BECAUSE MORE SCATTERED IN NATURE AS MID LEVEL FORCING MOVES NORTHEAST. WILL CAP POPS IN THE CHANCE RANGE TUESDAY...WITH SLIGHTLY HIGHER POPS OVER WESTERN SECTIONS CLOSER TO THE TROUGH. COULD BE JUST ENOUGH INSTABILITY ALOFT FOR THUNDER...MAINLY NW INTERIOR. BACKING UP A BIT...IF NAM PROVES TO BE CORRECT...HEAVIER RAIN WILL MOVE ACROSS EASTERN HALF OF THE CWA LATE TONIGHT/EARLY TUESDAY...BUT AGAIN THIS SOLUTION HAS BEEN DISCARDED AT THIS TIME. TEMPERATURES DO NOT FALL MUCH TONIGHT DUE TO CLOUDS AND ONSHORE FLOW. IF ANY SUN BREAKS OUT TUESDAY...ESPECIALLY WEST...TEMPS COULD REBOUND NICELY...AND FORECAST IS UNDERDONE. THINKING AROUND 70 NEAR THE COAST...AND MIDDLE TO UPPER 70S WEST FOR HIGHS TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... MODELS IN DECENT AGREEMENT WITH LONG-TERM OUTLOOK. COLD FRONT MOVES THROUGH THE REGION WEDNESDAY AFTERNOON...THEN BECOMES NEARLY STATIONARY EAST OF THE AREA. SEVERAL UPPER LEVEL DISTURBANCES MOVE ACROSS THE REGION THURSDAY THROUGH FRIDAY...FOLLOWED BY ANOTHER COLD FRONT LATE FRIDAY. T.S. ALBERTO IS NOT EXPECTED DIRECTLY IMPACT ON THE REGION...EXCEPT FOR LONG PERIOD SWELLS INCREASING SURF AT AREA BEACHES. REFER TO THE LATEST FORECASTS FROM THE NATIONAL HURRICANE CENTER FOR THE LATEST INFORMATION ON ALBERTO. WITH PERSISTENT ONSHORE FLOW...WARM AND HUMID AIRMASS REMAINS OVER THE AREA TUESDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT. ANY LINGERING SHOWERS TAPER OFF IN THE EVENING...THEN AREAS OF FOG DEVELOP AFTER MIDNIGHT...WITH LOCALLY DENSE FOG POSSIBLE IN THE OUTLYING AREAS. FOG SHOULD BURN OFF THROUGH WEDNESDAY MORNING. COLD FRONT THEN MOVES ACROSS THE AREA THROUGHOUT THE DAY. MODEL QPF INDICATING BEST CHANCES FOR PRECIP WILL BE OVER WESTERN ZONES...AS THE FRONT SEEMS TO WASH OUT AS IT MOVES THROUGH THE REGION. WILL CARRY HIGHEST POPS OVER WESTERN ZONES...WITH LOW CHANCE POPS OUT EAST IN THE AFTERNOON. HIGHS WEDNESDAY TOP OFF IN THE UPPER 70S TO LOWER 80S DESPITE THE CLOUDS/MORNING FOG. WEDNESDAY NIGHT...A CUTOFF H5 LOW BECOMES NEARLY STATIONARY OVER THE MID-ATLANTIC AREA AND WILL GRADUALLY TRACK NORTH THROUGH THE END OF THE WEEK. THAT LOW FINALLY DEPARTS FRIDAY NIGHT. DURING THIS TIME...ISOLATED TO SCATTERED SHOWERS WILL DEVELOP AS SEVERAL WEAK SHORTWAVES SPIN OFF THAT LOW. ONSHORE FLOW WILL USHER A MILD AIRMASS INTO THE REGION...KEEPING TEMPS IN THE 70S DESPITE CLOUD COVER. THESE TEMPS WILL BE ABOVE NORMAL THROUGH THE PERIOD. NEXT COLD FRONT APPROACHES ON SATURDAY AND WILL MOVE THROUGH THE REGION SATURDAY NIGHT. HIGH PRES RETURNS ON SUNDAY. && .AVIATION /09Z MONDAY THROUGH FRIDAY/... WEAK LOW PRESSURE DRIFTS NORTHWARD ALONG THE EASTERN SEABOARD THROUGH TODAY. A LARGER LOW APPROACHES BY TONIGHT BUT STAYS WELL OFFSHORE. CIGS OF MVFR TO IFR WILL TREND MORE IFR THIS MORNING AS SHOWER COVERAGE INCREASES. LOOKING FOR THIS TO STAY WITH A CHANCE OF IMPROVEMENT TO LOW END MVFR...1-2KFT IN THE AFTERNOON FOR SOME TERMINALS AWAY FROM THE COAST BUT THINK THIS IS QUITE LOW AT THE MOMENT. THEREFORE IFR CONTINUES IN THE TAFS WITH PERIODIC SHOWERS TODAY. VSBYS WITHIN SHOWERS COULD VARY BY A FEW MILES FROM FORECAST. FORECAST HAS VSBYS LOWERING TO MVFR WITH THE SHOWERS FOR TODAY. NE-E WINDS IN THE TAF PERIOD NEAR OR BELOW 10 KT. ...NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. KEWR FCSTER COMMENTS: IFR CIGS COULD ARRIVE 1-2 HRS LATER THAN FORECAST. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: IFR CIGS COULD ARRIVE 1-2 HRS LATER THAN FORECAST. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. KHPN FCSTER COMMENTS: IFR CIGS COULD ARRIVE 1-2 HRS LATER THAN FORECAST. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. .OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY... .TONIGHT...MVFR OR IFR IN RAIN/FOG. LOWER CONDITIONS POSSIBLE. .TUESDAY-WEDNESDAY...MVFR WITH IFR POSSIBLE. ISOLATED THUNDERSTORM WEST OF THE HUDSON TUESDAY AFTERNOON. FOG POSSIBLE TUESDAY NIGHT. .THURSDAY AND FRIDAY...MAINLY VFR...BUT MVFR OR IFR POSSIBLE IN SHOWERS ON FRIDAY. && .MARINE... SMALL CRAFT ADVISORY REMAINS UP FOR SEAS ACROSS THE OCEAN WATERS...DUE TO THE COMBINATION OF A PERSISTENT EASTERLY FETCH AND SWELL. THESE HIGHER SEAS CONTINUE THROUGH TUESDAY. FOR THE HARBORS/BAYS AND SOUND...SUB SCA CONDITIONS CONTINUE. A PERSISTENT ONSHORE FLOW SHOULD MAINTAIN SEAS AT SCA LEVELS OVER THE COASTAL OCEAN WATERS THROUGH WEDNESDAY...BUT SEAS SHOULD BEGIN TO SUBSIDE WEDNESDAY NIGHT AS SWELLS DEPART. LIGHT SOUTHERLY FLOW ON TAP INTO NEXT WEEKEND WILL KEEP CONDS BELOW SCA CRITERIA. && .HYDROLOGY... OVERALL...EXPECT ABOUT A HALF AN INCH TO THREE QUARTERS OF ANY INCH ON AVERAGE FOR SCATTERED TO NUMEROUS SHOWERS TODAY THROUGH TUESDAY. SOME AREAS MAY OBSERVE VERY LITTLE QPF...WHILE OTHER AREAS COULD RECEIVE IN EXCESS OF AN INCH...DEPENDING ON THE LOCATION OF ANY HEAVIER SHOWERS. AS SUCH...HIGHLY UNCERTAIN RAINFALL AMOUNTS FOR ANY PARTICULAR LOCATION CONTINUE. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT TUESDAY FOR ANZ350-353-355. && $$ SYNOPSIS...MPS/PW NEAR TERM...PW SHORT TERM...PW LONG TERM...MPS AVIATION...JM MARINE...MPS/PW HYDROLOGY...PW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
327 AM EDT MON MAY 21 2012 .SYNOPSIS... A SERIES OF LOW PRESSURE SYSTEMS WILL IMPACT THE AREA THROUGH TUESDAY. A COLD FRONT MOVES THROUGH THE REGION ON WEDNESDAY...FOLLOWED BY ANOTHER COLD FRONT ON SATURDAY. HIGH PRESSURE RETURNS THEREAFTER. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... HRRR AND RAP IN THE NEAR TERM SHOWS SHOWER COVERAGE EVER SO SLOWLY INCREASES FROM THE SOUTH THIS MORNING. COULD TAKE SOMETIME FOR INTERIOR ZONES TO SEE PRECIP AS ENOUGH DRY AIR REMAINS. FEEL LIKELY COVERAGE IS WARRANTED BY AFTERNOON ACROSS MUCH OF THE AREA. OVERALL...PERSISTENT EASTERLY FLOW PREVAILS AS ATMOSPHERE BECOMES SATURATED. OPERATIONAL MODELS STILL SHOW PRECIPITABLE WATERS OF 150 TO 175 PERCENT ABOVE NORMAL AS THE DAY PROGRESSES. WEAK LIFT EMBEDDED IN THE MID LEVELS...ALONG WITH INCREASING ISENTROPIC LIFT WILL RESULT IN SHOWERS TODAY...AND PLENTY OF CLOUDS. MOIST MARINE AIR WILL KEEP TEMPS IN THE 60S...WITH A MOS BLEND FOLLOWED. LEANED TOWARD COOLER MET MOS WHERE APPROPRIATE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... MODELS STILL DIFFER THIS TIME FRAME ON SUBTLE FEATURES. NAM SOLUTION WAS DISCARDED FOR THIS FORECAST. NAM FORECASTS A DEEPER MID LEVEL LOW...AND TRACKS THE SFC LOW FROM THE WESTERN ATLANTIC TO JUST EAST OF MONTAUK POINT LATE TONIGHT/EARLY TUESDAY. IT IS IMPORTANT TO NOTE THAT THIS WAVE IS NOT ALBERTO. PLEASE SEE THE LATEST ADVISORIES REGARDING ALBERTO FROM THE NATIONAL HURRICANE CENTER. REFER TO NHC FOR THE LATEST ADVISORIES...TRACK FORECASTS AND DISCUSSIONS REGARDING ALBERTO. ANYWAY...LEANED TOWARD A SREF/ECMWF SOLUTIONS WITH REGARD TO THE FORECAST WITH A SLIGHTLY WEAKER AND FURTHER EAST LOW FOR LATE TONIGHT/EARLY TUESDAY. BY TUESDAY...THIS WAVE MOVES TO THE NORTHEAST AS A GENERAL WEAK TROUGH APPROACHES FROM THE WEST. LIKELY POPS EARLY TONIGHT...THEN COVERAGE BECAUSE MORE SCATTERED IN NATURE AS MID LEVEL FORCING MOVES NORTHEAST. WILL CAP POPS IN THE CHANCE RANGE TUESDAY...WITH SLIGHTLY HIGHER POPS OVER WESTERN SECTIONS CLOSER TO THE TROUGH. COULD BE JUST ENOUGH INSTABILITY ALOFT FOR THUNDER...MAINLY NW INTERIOR. BACKING UP A BIT...IF NAM PROVES TO BE CORRECT...HEAVIER RAIN WILL MOVE ACROSS EASTERN HALF OF THE CWA LATE TONIGHT/EARLY TUESDAY...BUT AGAIN THIS SOLUTION HAS BEEN DISCARDED AT THIS TIME. TEMPERATURES DO NOT FALL MUCH TONIGHT DUE TO CLOUDS AND ONSHORE FLOW. IF ANY SUN BREAKS OUT TUESDAY...ESPECIALLY WEST...TEMPS COULD REBOUND NICELY...AND FORECAST IS UNDERDONE. THINKING AROUND 70 NEAR THE COAST...AND MIDDLE TO UPPER 70S WEST FOR HIGHS TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... MODELS IN DECENT AGREEMENT WITH LONG-TERM OUTLOOK. COLD FRONT MOVES THROUGH THE REGION WEDNESDAY AFTERNOON...THEN BECOMES NEARLY STATIONARY EAST OF THE AREA. SEVERAL UPPER LEVEL DISTURBANCES MOVE ACROSS THE REGION THURSDAY THROUGH FRIDAY...FOLLOWED BY ANOTHER COLD FRONT LATE FRIDAY. T.S. ALBERTO IS NOT EXPECTED DIRECTLY IMPACT ON THE REGION...EXCEPT FOR LONG PERIOD SWELLS INCREASING SURF AT AREA BEACHES. REFER TO THE LATEST FORECASTS FROM THE NATIONAL HURRICANE CENTER FOR THE LATEST INFORMATION ON ALBERTO. WITH PERSISTENT ONSHORE FLOW...WARM AND HUMID AIRMASS REMAINS OVER THE AREA TUESDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT. ANY LINGERING SHOWERS TAPER OFF IN THE EVENING...THEN AREAS OF FOG DEVELOP AFTER MIDNIGHT...WITH LOCALLY DENSE FOG POSSIBLE IN THE OUTLYING AREAS. FOG SHOULD BURN OFF THROUGH WEDNESDAY MORNING. COLD FRONT THEN MOVES ACROSS THE AREA THROUGHOUT THE DAY. MODEL QPF INDICATING BEST CHANCES FOR PRECIP WILL BE OVER WESTERN ZONES...AS THE FRONT SEEMS TO WASH OUT AS IT MOVES THROUGH THE REGION. WILL CARRY HIGHEST POPS OVER WESTERN ZONES...WITH LOW CHANCE POPS OUT EAST IN THE AFTERNOON. HIGHS WEDNESDAY TOP OFF IN THE UPPER 70S TO LOWER 80S DESPITE THE CLOUDS/MORNING FOG. WEDNESDAY NIGHT...A CUTOFF H5 LOW BECOMES NEARLY STATIONARY OVER THE MID-ATLANTIC AREA AND WILL GRADUALLY TRACK NORTH THROUGH THE END OF THE WEEK. THAT LOW FINALLY DEPARTS FRIDAY NIGHT. DURING THIS TIME...ISOLATED TO SCATTERED SHOWERS WILL DEVELOP AS SEVERAL WEAK SHORTWAVES SPIN OFF THAT LOW. ONSHORE FLOW WILL USHER A MILD AIRMASS INTO THE REGION...KEEPING TEMPS IN THE 70S DESPITE CLOUD COVER. THESE TEMPS WILL BE ABOVE NORMAL THROUGH THE PERIOD. NEXT COLD FRONT APPROACHES ON SATURDAY AND WILL MOVE THROUGH THE REGION SATURDAY NIGHT. HIGH PRES RETURNS ON SUNDAY. && .AVIATION /08Z MONDAY THROUGH FRIDAY/... WEAK LOW PRESSURE DRIFTS NORTHWARD ALONG THE EASTERN SEABOARD THROUGH TODAY. CIGS OF MVFR TO ISOLATED IFR WILL TREND MORE IFR TOWARDS DAYBREAK NEAR THE ONSET OF SHOWERS. LOOKING FOR THIS TO STAY WITH A CHANCE OF IMPROVEMENT TO LOW END MVFR...1-2KFT IN THE AFTERNOON BUT THINK THIS IS QUITE LOW AT THE MOMENT. THEREFORE IFR CONTINUES IN THE TAFS WITH PERIODIC SHOWERS. VSBYS LARGE UNCERTAINTY WITHIN SHOWERS AND COULD VARY BY A FEW MILES FROM FORECAST. FORECAST HAS VSBYS LOWERING TO MVFR WITH THE SHOWERS FOR TODAY. TIMING OF ONSET OF SHOWERS HAS A 1 TO 2 HOUR UNCERTAINTY. WINDS IN THE TAF PERIOD NEAR OR BELOW 10 KT FROM THE EAST ON AVERAGE. .OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY... .TONIGHT...MVFR OR IFR IN RAIN. LOWER CONDITIONS POSSIBLE. .TUESDAY-WEDNESDAY...MVFR WITH IFR POSSIBLE. ISOLATED THUNDERSTORM WEST OF THE HUDSON TUESDAY AFTERNOON. FOG POSSIBLE TUESDAY NIGHT. .THURSDAY AND FRIDAY...MAINLY VFR...BUT MVFR OR IFR POSSIBLE IN SHOWERS ON FRIDAY. && .MARINE... SMALL CRAFT ADVISORY REMAINS UP FOR SEAS ACROSS THE OCEAN WATERS...DUE TO THE COMBINATION OF A PERSISTENT EASTERLY FETCH AND SWELL. THESE HIGHER SEAS CONTINUE THROUGH TUESDAY. FOR THE HARBORS/BAYS AND SOUND...SUB SCA CONDITIONS CONTINUE. A PERSISTENT ONSHORE FLOW SHOULD MAINTAIN SEAS AT SCA LEVELS OVER THE COASTAL OCEAN WATERS THROUGH WEDNESDAY...BUT SEAS SHOULD BEGIN TO SUBSIDE WEDNESDAY NIGHT AS SWELLS DEPART. LIGHT SOUTHERLY FLOW ON TAP INTO NEXT WEEKEND WILL KEEP CONDS BELOW SCA CRITERIA. && .HYDROLOGY... OVERALL...EXPECT ABOUT A HALF AN INCH TO THREE QUARTERS OF ANY INCH ON AVERAGE FOR SCATTERED TO NUMEROUS SHOWERS TODAY THROUGH TUESDAY. SOME AREAS MAY OBSERVE VERY LITTLE QPF...WHILE OTHER AREAS COULD RECEIVE IN EXCESS OF AN INCH...DEPENDING ON THE LOCATION OF ANY HEAVIER SHOWERS. AS SUCH...HIGHLY UNCERTAIN RAINFALL AMOUNTS FOR ANY PARTICULAR LOCATION CONTINUE. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT TUESDAY FOR ANZ350-353-355. && $$ SYNOPSIS...MPS/PW NEAR TERM...PW SHORT TERM...PW LONG TERM...MPS AVIATION...JM MARINE...MPS/PW HYDROLOGY...PW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
206 AM EDT MON MAY 21 2012 .SYNOPSIS... HIGH PRESSURE DEPARTS TODAY. A WAVE OF LOW PRESSURE WILL MOVE TOWARD THE AREA AND REMAIN LATER TODAY BEFORE MOVING TO THE NORTHEAST TONIGHT. A SERIES OF WEAK LOW PRESSURE SYSTEMS WILL CREATE UNSETTLED CONDITIONS ACROSS THE TRI-STATE INTO WEDNESDAY. A COLD FRONT WILL PUSH INTO THE REGION LATE WEDNESDAY...THEN STALL OUT NEARBY INTO FRIDAY. ANOTHER COLD FRONT APPROACHES FROM THE NORTHWEST FRIDAY NIGHT...THEN MOVES ACROSS THE AREA SATURDAY AND SATURDAY EVENING. HIGH PRESSURE THEN BUILDS DOWN FROM CANADA INTO SUNDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... UPDATES INCLUDE FURTHER ADJUSTMENTS TO MAINLY SKY/POP/TEMP AND DEWPOINT GRIDS. NOW LOOKS CHANCES OF RAINFALL WILL BE LATE AT NIGHT. LIKELIHOOD OF SHOWERS PROBABLY DOESN`T ARRIVE UNTIL AROUND DAYBREAK FOR THE SOUTHERNMOST PORTIONS OF THE CWA...BUT ISOLATED TO SCATTERED SHOWERS ARE EXPECTED TO BE IN THE VICINITY AFTER MIDNIGHT. MOST RECENT RUNS OF THE HRRR AND RUC MODELS GENERALLY AGREE WITH THIS TREND. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/... TROPICAL STORM ALBERTO DOES NOT HAVE A DIRECT IMPACT TO THE LOCAL AREA BASED ON THE LATEST MODEL GUIDANCE AND TRACK FORECAST FROM THE NATIONAL HURRICANE CENTER. PLEASE REFER TO NHC FOR THE LATEST ADVISORIES...TRACK FORECASTS AND DISCUSSIONS REGARDING TROPICAL STORM ALBERTO. SYNOPTIC FEATURES REMAIN WEAK THROUGH MONDAY NIGHT AS BROAD UPPER TROUGH REMAINS ALONG THE EASTERN PORTION OF THE COUNTRY. WAVES OF LOW PRESSURE MOVE ALONG THE COAST THROUGH THE PERIOD. CURRENT THINKING IS THE BEST CHANCE OF PRECIPITATION IS DURING THE DAY MONDAY AND INTO THE EARLY EVENING WITH THE BEST SYNOPTIC FORCING...ALTHOUGH WEAK. PRECIPITABLE WATER VALUES INCREASE TO AROUND 1.5 INCHES DURING THIS PERIOD AND IS ABOUT 170 PERCENT OF NORMAL. SO WENT WITH MODERATE SHOWERS. MARINE LAYER WILL BE IN PLACE MONDAY AND MONDAY NIGHT WITH THE AREA STABLE SO WILL NOT MENTION THUNDER. WITH CLOUDS...EAST FLOW AND RAIN...LEANED TOWARD THE LOWER NAM GUIDANCE FOR HIGHS MONDAY...AND USED A BLEND FOR MONDAY NIGHTS LOWS. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... THE MODELS ARE IN MUCH BETTER AGREEMENT THAN YESTERDAY FOR THE MID TO LATE WEEK TIME FRAME. USED A BLEND OF THE NAM/SREF/ECMWF/GFS FOR THE FORECAST TUESDAY-WEDNESDAY AND THE GFS/ECMWF/CMC-GLOBAL WEDNESDAY NIGHT-SUNDAY. T.S. ALBERTO IS EXPECTED TO HAVE NO DIRECT IMPACT ON THE REGION...EXCEPT FOR LONG PERIOD SWELLS INCREASING SURF AT AREA BEACHES. REFER TO THE LATEST FORECASTS FROM THE NATIONAL HURRICANE CENTER FOR THE LATEST INFORMATION ON ALBERTO. A SERIES OF WEAK SHORTWAVES CROSS THE AREA TUESDAY-THURSDAY NIGHT. DURING THIS TIME FRAME...WILL JUST BE IN A MOIST/RELATIVELY HUMID ENVIRONMENT...WITH AN ONSHORE FLOW PROMOTING A MARINE LAYER AND CLOUD COVER NEAR THE COAST...WITH LESS OF AN INFLUENCE/CLOUDS OVER THE INTERIOR. WITH MORE INSTABILITY EXPECTED INLAND...HAVE GONE WITH CHANCE POPS ACROSS THE INTERIOR AND SLIGHT CHANCE POPS OVER COASTAL AREAS DURING THE DAY AND SLIGHT CHANCE POPS AT NIGHT. HAVE A CHANCE OF THUNDER DURING THE DAY TUESDAY/WEDNESDAY ACROSS INTERIOR ZONES AS WELL WITH SOME MARGINAL INSTABILITY EXPECTED. WITH A RATHER DIFFUSE FRONT DISSIPATING OVER THE REGION FRIDAY...ONLY HAVE SLIGHT CHANCE POPS OVER THE INTERIOR THEN. WITH PERSISTENT ONSHORE FLOW EXPECTED INTO WEDNESDAY...HAVE FOG IN EARLY TUESDAY MORNING...AND AGAIN FROM LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. WITH A SHORTWAVE FORECAST TO PASS THROUGH FRIDAY NIGHT...HAVE SLIGHT CHANCE POPS THROUGHOUT. WITH THE APPROACH/PASSAGE OF A COLD FRONT SATURDAY...HAVE A CHANCE OF THUNDER THROUGHOUT...TAPERING TO A DRY FORECAST BY SUNDAY AS RIDGING BEGINS TO BUILD IN. FOR TEMPERATURES...USED A BLEND OF MAV/MET GUIDANCE/NAM 2-METER TEMPERATURES AND MIXING DOWN FROM 950 HPA FOR HIGHS ON TUESDAY...WITH VALUES FORECAST SLIGHTLY ABOVE NORMAL. FOR LOWS TUESDAY NIGHT USED A BLEND OF BIAS CORRECTED MAV GUIDANCE WITH MET GUIDANCE AND NAM 2-METER TEMPERATURES...WHICH YIELDED VALUES AROUND 5 DEGREES ABOVE NORMAL. FOR HIGHS WEDNESDAY USED A BLEND OF MIXING DOWN FROM 925 HPA NEAR THE COAST...850 HPA INLAND...WITH NAM 2-METER TEMPERATURES...AND MEX GUIDANCE. THIS YIELDS VALUES 5 TO 10 DEGREES ABOVE NORMAL. FROM WEDNESDAY NIGHT-SUNDAY BLENDED 18Z HPC GUIDANCE WITH A MEX/MEX ENSEMBLE MEAN BLEND. THIS YIELDED ABOVE NORMAL TEMPERATURES THROUGH THIS TIME FRAME. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... WEAK LOW PRESSURE DRIFTS NORTHWARD ALONG THE EASTERN SEABOARD THROUGH TODAY. CIGS OF MVFR TO ISOLATED IFR WILL TREND MORE IFR TOWARDS DAYBREAK NEAR THE ONSET OF SHOWERS. LOOKING FOR THIS TO STAY WITH A CHANCE OF IMPROVEMENT TO LOW END MVFR...1-2KFT IN THE AFTERNOON BUT THINK THIS IS QUITE LOW AT THE MOMENT. THEREFORE IFR CONTINUES IN THE TAFS WITH PERIODIC SHOWERS. VSBYS LARGE UNCERTAINTY WITHIN SHOWERS AND COULD VARY BY A FEW MILES FROM FORECAST. FORECAST HAS VSBYS LOWERING TO MVFR WITH THE SHOWERS FOR TODAY. TIMING OF ONSET OF SHOWERS HAS A 1 TO 2 HOUR UNCERTAINTY. WINDS IN THE TAF PERIOD NEAR OR BELOW 10 KT FROM THE EAST ON AVERAGE. .OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY... .TONIGHT...MVFR OR IFR IN RAIN. LOWER CONDITIONS POSSIBLE. .TUESDAY-WEDNESDAY...MVFR WITH IFR POSSIBLE. ISOLATED THUNDERSTORM WEST OF THE HUDSON TUESDAY AFTERNOON. FOG POSSIBLE TUESDAY NIGHT. .THURSDAY AND FRIDAY...MAINLY VFR...BUT MVFR OR IFR POSSIBLE IN SHOWERS ON FRIDAY. && .MARINE... FORECAST APPEARS ON TRACK. A EAST TO SOUTHEAST SWELL WILL CONTINUE ACROSS THE OCEAN WATERS THROUGH AT LEAST TONIGHT AS LOW PRESSURE ALONG THE MID ATLANTIC COAST BEGINS TO MOVE TO THE NORTHEAST. WINDS ACROSS THE FORECAST WATERS WILL REMAIN BELOW SMALL CRAFT LEVELS THROUGH THE PERIOD WITH A WEAK PRESSURE GRADIENT. THE SMALL CRAFT FOR HAZARDOUS SEAS REMAINS EXTENDED THROUGH TONIGHT AS SEAS WILL REMAIN AROUND 5 FT THROUGH THE TIME FRAME. A PERSISTENT ONSHORE FLOW SHOULD MAINTAIN SEAS AT SCA LEVELS OVER THE COASTAL OCEAN WATERS FROM TUESDAY INTO WEDNESDAY...BUT WITH THE WINDS VEERING FROM SE ON TUESDAY TO S-SW BY WEDNESDAY...EXPECT SEAS TO BEGIN TO DIMINISH STARTING TUESDAY NIGHT. OTHERWISE...WITH A RELATIVELY LIGHT PRESSURE GRADIENT FORECAST ACROSS THE AREA EXPECT CONDITIONS TO REMAIN WELL BELOW SCA THRESHOLDS FROM TUESDAY INTO FRIDAY. && .HYDROLOGY... GENERALLY LIGHT PRECIPITATION IS EXPECTED TODAY AND CONTINUES THROUGH AT LEAST TONIGHT. THE BULK OF THE PRECIPITATION WILL LIKELY OCCUR DURING THE DAY MONDAY. TOTAL PRECIPITATION THROUGH TONIGHT WILL RANGE FROM AROUND A THIRD OF AN INCH FAR WESTERN SECTIONS TO AROUND TWO THIRDS OF AN INCH ACROSS MUCH OF THE CWA. THERE IS SOME POTENTIAL FOR SIGNIFICANT RAINFALL INTO THE MIDDLE OF THE WEEK. THERE IS STILL QUITE A BIT OF UNCERTAINTY AS TO EXACTLY HOW MUCH OF THIS TIME FRAME WILL ACTUALLY HAVE PRECIPITATION FALL...AND HOW INTENSE IT WILL BE. IT IS APPEARING MORE LIKELY THOUGH THAT IF THERE IS ANY HEAVY RAINFALL...IT MOST LIKELY WILL BE FROM NYC ON N AND W. HOWEVER WITH PRECIPITABLE WATERS FORECAST TO BE 150-175% ABOVE NORMAL IN THIS TIME FRAME...AND THE POTENTIAL FOR CONVECTION...AREAS OF LOCALLY HEAVY RAINFALL CANNOT BE RULED OUT ANY WHERE ACROSS THE CWA. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT TUESDAY FOR ANZ350-353-355. && $$ SYNOPSIS...MALOIT/MET NEAR TERM...JC/MALOIT/LN SHORT TERM...MET LONG TERM...MALOIT AVIATION...JM MARINE...MALOIT/MET HYDROLOGY...MALOIT/MET
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1244 AM EDT MON MAY 21 2012 .SYNOPSIS... HIGH PRESSURE DEPARTS TODAY. A WAVE OF LOW PRESSURE WILL MOVE TOWARD THE AREA AND REMAIN LATER TODAY BEFORE MOVING TO THE NORTHEAST TONIGHT. A SERIES OF WEAK LOW PRESSURE SYSTEMS WILL CREATE UNSETTLED CONDITIONS ACROSS THE TRI-STATE INTO WEDNESDAY. A COLD FRONT WILL PUSH INTO THE REGION LATE WEDNESDAY...THEN STALL OUT NEARBY INTO FRIDAY. ANOTHER COLD FRONT APPROACHES FROM THE NORTHWEST FRIDAY NIGHT...THEN MOVES ACROSS THE AREA SATURDAY AND SATURDAY EVENING. HIGH PRESSURE THEN BUILDS DOWN FROM CANADA INTO SUNDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... UPDATES INCLUDE FURTHER ADJUSTMENTS TO MAINLY SKY/POP/TEMP AND DEWPOINT GRIDS. NOW LOOKS CHANCES OF RAINFALL WILL BE LATE AT NIGHT. LIKELIHOOD OF SHOWERS PROBABLY DOESN`T ARRIVE UNTIL AROUND DAYBREAK FOR THE SOUTHERNMOST PORTIONS OF THE CWA...BUT ISOLATED TO SCATTERED SHOWERS ARE EXPECTED TO BE IN THE VICINITY AFTER MIDNIGHT. MOST RECENT RUNS OF THE HRRR AND RUC MODELS GENERALLY AGREE WITH THIS TREND. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/... TROPICAL STORM ALBERTO DOES NOT HAVE A DIRECT IMPACT TO THE LOCAL AREA BASED ON THE LATEST MODEL GUIDANCE AND TRACK FORECAST FROM THE NATIONAL HURRICANE CENTER. PLEASE REFER TO NHC FOR THE LATEST ADVISORIES...TRACK FORECASTS AND DISCUSSIONS REGARDING TROPICAL STORM ALBERTO. SYNOPTIC FEATURES REMAIN WEAK THROUGH MONDAY NIGHT AS BROAD UPPER TROUGH REMAINS ALONG THE EASTERN PORTION OF THE COUNTRY. WAVES OF LOW PRESSURE MOVE ALONG THE COAST THROUGH THE PERIOD. CURRENT THINKING IS THE BEST CHANCE OF PRECIPITATION IS DURING THE DAY MONDAY AND INTO THE EARLY EVENING WITH THE BEST SYNOPTIC FORCING...ALTHOUGH WEAK. PRECIPITABLE WATER VALUES INCREASE TO AROUND 1.5 INCHES DURING THIS PERIOD AND IS ABOUT 170 PERCENT OF NORMAL. SO WENT WITH MODERATE SHOWERS. MARINE LAYER WILL BE IN PLACE MONDAY AND MONDAY NIGHT WITH THE AREA STABLE SO WILL NOT MENTION THUNDER. WITH CLOUDS...EAST FLOW AND RAIN...LEANED TOWARD THE LOWER NAM GUIDANCE FOR HIGHS MONDAY...AND USED A BLEND FOR MONDAY NIGHTS LOWS. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... THE MODELS ARE IN MUCH BETTER AGREEMENT THAN YESTERDAY FOR THE MID TO LATE WEEK TIME FRAME. USED A BLEND OF THE NAM/SREF/ECMWF/GFS FOR THE FORECAST TUESDAY-WEDNESDAY AND THE GFS/ECMWF/CMC-GLOBAL WEDNESDAY NIGHT-SUNDAY. T.S. ALBERTO IS EXPECTED TO HAVE NO DIRECT IMPACT ON THE REGION...EXCEPT FOR LONG PERIOD SWELLS INCREASING SURF AT AREA BEACHES. REFER TO THE LATEST FORECASTS FROM THE NATIONAL HURRICANE CENTER FOR THE LATEST INFORMATION ON ALBERTO. A SERIES OF WEAK SHORTWAVES CROSS THE AREA TUESDAY-THURSDAY NIGHT. DURING THIS TIME FRAME...WILL JUST BE IN A MOIST/RELATIVELY HUMID ENVIRONMENT...WITH AN ONSHORE FLOW PROMOTING A MARINE LAYER AND CLOUD COVER NEAR THE COAST...WITH LESS OF AN INFLUENCE/CLOUDS OVER THE INTERIOR. WITH MORE INSTABILITY EXPECTED INLAND...HAVE GONE WITH CHANCE POPS ACROSS THE INTERIOR AND SLIGHT CHANCE POPS OVER COASTAL AREAS DURING THE DAY AND SLIGHT CHANCE POPS AT NIGHT. HAVE A CHANCE OF THUNDER DURING THE DAY TUESDAY/WEDNESDAY ACROSS INTERIOR ZONES AS WELL WITH SOME MARGINAL INSTABILITY EXPECTED. WITH A RATHER DIFFUSE FRONT DISSIPATING OVER THE REGION FRIDAY...ONLY HAVE SLIGHT CHANCE POPS OVER THE INTERIOR THEN. WITH PERSISTENT ONSHORE FLOW EXPECTED INTO WEDNESDAY...HAVE FOG IN EARLY TUESDAY MORNING...AND AGAIN FROM LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. WITH A SHORTWAVE FORECAST TO PASS THROUGH FRIDAY NIGHT...HAVE SLIGHT CHANCE POPS THROUGHOUT. WITH THE APPROACH/PASSAGE OF A COLD FRONT SATURDAY...HAVE A CHANCE OF THUNDER THROUGHOUT...TAPERING TO A DRY FORECAST BY SUNDAY AS RIDGING BEGINS TO BUILD IN. FOR TEMPERATURES...USED A BLEND OF MAV/MET GUIDANCE/NAM 2-METER TEMPERATURES AND MIXING DOWN FROM 950 HPA FOR HIGHS ON TUESDAY...WITH VALUES FORECAST SLIGHTLY ABOVE NORMAL. FOR LOWS TUESDAY NIGHT USED A BLEND OF BIAS CORRECTED MAV GUIDANCE WITH MET GUIDANCE AND NAM 2-METER TEMPERATURES...WHICH YIELDED VALUES AROUND 5 DEGREES ABOVE NORMAL. FOR HIGHS WEDNESDAY USED A BLEND OF MIXING DOWN FROM 925 HPA NEAR THE COAST...850 HPA INLAND...WITH NAM 2-METER TEMPERATURES...AND MEX GUIDANCE. THIS YIELDS VALUES 5 TO 10 DEGREES ABOVE NORMAL. FROM WEDNESDAY NIGHT-SUNDAY BLENDED 18Z HPC GUIDANCE WITH A MEX/MEX ENSEMBLE MEAN BLEND. THIS YIELDED ABOVE NORMAL TEMPERATURES THROUGH THIS TIME FRAME. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... HIGH PRESSURE REMAINS JUST OFF THE NEW ENGLAND COAST AS WEAK LOW PRESSURE DRIFTS NORTHWARD TONIGHT AND MONDAY. 1000-2000 FT CEILINGS HAVE ARRIVED OVER SOME OF THE SOUTHERN TERMINALS. EXPECTING REST THE OF THE TERMINALS TO HAVE SIMILAR CEILINGS BY 05Z-08Z...WITH IFR CEILINGS FOR AT LEAST KJFK AND KISP BY THIS PERIOD. FORECAST TIMING OF OTHER TERMINALS DROPPING TO IFR CONDITIONS MAY BE COUPLE HOURS TOO SLOW. AS FOR LIKELIHOOD OF SHOWERS...LOOKS TO BE TOWARDS DAYBREAK FOR THE CITY/SOUTHERN TERMINALS...BUT KJFK MAY PICK UP BRIEF MOMENTS OF DRIZZLE BEFOREHAND. .OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY... .MONDAY NIGHT...MVFR OR IFR IN RAIN. .TUESDAY-WEDNESDAY...MVFR WITH IFR POSSIBLE. ISOLATED THUNDERSTORM WEST OF THE HUDSON TUESDAY AFTERNOON. FOG POSSIBLE TUESDAY NIGHT. .THURSDAY AND FRIDAY...MAINLY VFR...BUT MVFR OR IFR POSSIBLE IN SHOWERS ON FRIDAY. && .MARINE... FORECAST APPEARS ON TRACK. A EAST TO SOUTHEAST SWELL WILL CONTINUE ACROSS THE OCEAN WATERS THROUGH AT LEAST TONIGHT AS LOW PRESSURE ALONG THE MID ATLANTIC COAST BEGINS TO MOVE TO THE NORTHEAST. WINDS ACROSS THE FORECAST WATERS WILL REMAIN BELOW SMALL CRAFT LEVELS THROUGH THE PERIOD WITH A WEAK PRESSURE GRADIENT. THE SMALL CRAFT FOR HAZARDOUS SEAS REMAINS EXTENDED THROUGH TONIGHT AS SEAS WILL REMAIN AROUND 5 FT THROUGH THE TIME FRAME. A PERSISTENT ONSHORE FLOW SHOULD MAINTAIN SEAS AT SCA LEVELS OVER THE COASTAL OCEAN WATERS FROM TUESDAY INTO WEDNESDAY...BUT WITH THE WINDS VEERING FROM SE ON TUESDAY TO S-SW BY WEDNESDAY...EXPECT SEAS TO BEGIN TO DIMINISH STARTING TUESDAY NIGHT. OTHERWISE...WITH A RELATIVELY LIGHT PRESSURE GRADIENT FORECAST ACROSS THE AREA EXPECT CONDITIONS TO REMAIN WELL BELOW SCA THRESHOLDS FROM TUESDAY INTO FRIDAY. && .HYDROLOGY... GENERALLY LIGHT PRECIPITATION IS EXPECTED TODAY AND CONTINUES THROUGH AT LEAST TONIGHT. THE BULK OF THE PRECIPITATION WILL LIKELY OCCUR DURING THE DAY MONDAY. TOTAL PRECIPITATION THROUGH TONIGHT WILL RANGE FROM AROUND A THIRD OF AN INCH FAR WESTERN SECTIONS TO AROUND TWO THIRDS OF AN INCH ACROSS MUCH OF THE CWA. THERE IS SOME POTENTIAL FOR SIGNIFICANT RAINFALL INTO THE MIDDLE OF THE WEEK. THERE IS STILL QUITE A BIT OF UNCERTAINTY AS TO EXACTLY HOW MUCH OF THIS TIME FRAME WILL ACTUALLY HAVE PRECIPITATION FALL...AND HOW INTENSE IT WILL BE. IT IS APPEARING MORE LIKELY THOUGH THAT IF THERE IS ANY HEAVY RAINFALL...IT MOST LIKELY WILL BE FROM NYC ON N AND W. HOWEVER WITH PRECIPITABLE WATERS FORECAST TO BE 150-175% ABOVE NORMAL IN THIS TIME FRAME...AND THE POTENTIAL FOR CONVECTION...AREAS OF LOCALLY HEAVY RAINFALL CANNOT BE RULED OUT ANY WHERE ACROSS THE CWA. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT TUESDAY FOR ANZ350-353-355. && $$ SYNOPSIS...MALOIT/MET NEAR TERM...JC/MALOIT/LN SHORT TERM...MET LONG TERM...MALOIT AVIATION...JC MARINE...MALOIT/MET HYDROLOGY...MALOIT/MET
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
908 PM EDT TUE MAY 22 2012 .SYNOPSIS... A LOW PRESSURE SYSTEM SOUTHEAST OF CAPE COD WILL DRIFT NORTHEAST TONIGHT AND WEDNESDAY. A HIGH PRESSURE SYSTEM WILL THEN BUILD IN BEHIND IT OVER THE CANADIAN MARITIMES ON THURSDAY AND SLOWLY SINK SOUTHWEST OVER THE MEMORIAL DAY WEEKEND AND BECOME ESTABLISHED OFF THE SOUTHEAST UNITED STATES COAST. A BACKDOOR COLD FRONT WILL TRY TO SAG SOUTH INTO THE AREA ABOUT SUNDAY BEFORE RETREATING NORTH ON MEMORIAL DAY. A FRONT DOOR COLD FRONT WILL APPROACH THE AREA FROM THE GREAT LAKES ON TUESDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... THE MAIN FOCUS EARLY THIS EVENING HAS SHIFTED TO THE POTENTIAL FOR LOCALLY HEAVY RAIN. THE ENVIRONMENTAL WINDS ARE FAIRLY LIGHT...AND THIS IS RESULTING IN A SLOW SOUTHEAST TRUNDLE TO THE SHOWERS. THE AIRMASS IS ALSO FAIRLY MOIST...WITH AN AXIS OF PRECIPITABLE WATER NEAR 1.50 INCHES RUNNING THROUGH SOUTHEAST PENNSYLVANIA INTO NORTHERN NEW JERSEY. THE COMBINATION OF SLOW MOVEMENT AND HIGH PRECIPITABLE WATER RAISES THE SPECTER OF LOCALIZED HEAVY RAIN. ONE HOUR GRIDDED FLASH FLOOD GUIDANCE SHOWS THAT 1.75 TO ABOUT 2.00 INCHES OF RAIN WOULD BE NEEDED TO INITIATE FLASH FLOODING. AS LONG AS THE CELLS KEEP MOVING...THE THREAT OF FLASH FLOODING SHOULD REMAIN LOW. HOWEVER...WE WILL CONTINUE TO MONITOR FOR THE POTENTIAL FOR THE REST OF THE EVENING. OTHERWISE...DESPITE BREAKS IN THE CLOUDS THIS AFTERNOON... THE SCATTERED SHOWER ACTIVITY HAS NOT SHOWN ANY LIGHTNING AS OF EARLY EVENING. IN FACT...TOPS HAVE NOT GOTTEN TO MINUS 20 CELSIUS YET...AND THIS WOULD SEEM TO EXPLAIN THE LACK OF LIGHTNING DATA TO THIS POINT. THE LOSS OF DAYTIME HEATING SOON PROBABLY MEANS THE WINDOW OF OPPORTUNITY FOR THUNDER WITH THE SCATTERED SHOWERS DEVELOPING IS CLOSING. THE LATEST HRRR RUN IS TRYING TO DEVELOP A BROKEN LINE OF THUNDERSTORMS IN THE BEST INSTABILITY. THIS LIES ACROSS WEST CENTRAL PENNSYLVANIA (WHERE THE SUNSHINE HAD A BETTER CHANCE TO DESTABILIZE THE AIRMASS. THE IN SITU BULK SHEAR PROFILE IS NOT THAT IMPRESSIVE...AND DOES NOT APPEAR TO GET ANY BETTER INTO THE LATER EVENING HOURS. WHILE THERE IS SOME ACTIVITY NOW IN THE AXIS OF BEST INSTABILITY...IT IS UNCLEAR JUST HOW MUCH OF THIS ACTIVITY SURVIVES TO THE LEHIGH VALLEY AFTER 800 PM. FOR NOW...WILL LEAVE THE MENTION OF THUNDER IN DEFERENCE TO THE ACTIVITY TO THE WEST. AS THE ACTIVITY CONTINUES TO DROP TOP THE SOUTH ALONG THE LINE OUT WEST...A MENTION OF ISOLATED THUNDER WAS RETAINED IN EARLY MORNING FOR THE DELAWARE RIVER WEST. THE NEXT FORECAST PROBLEM FOR TONIGHT IS THE LOW CLOUDS AND FOG. THE LOW CLOUDS DID BREAK THIS AFTERNOON...AND PATCHES ARE TRYING TO REFORM EARLY THIS EVENING. NAM MODEL SOUNDINGS SHOW THAT THE REDEVELOPMENT OF STRATUS COULD TAKE SOME TIME...ESPECIALLY WEST OF THE DELAWARE RIVER. BASED ON THE CURRENT CLOUD COVER AND THE NAM MODEL SOUNDINGS...THE TIMING OF THE STRATUS REAPPEARANCE HAS BEEN PUSHED BACK A BIT. STATISTICAL GUIDANCE SUGGESTS THAT TONIGHT COULD END UP BEING A A BETTER SETUP FOR AREAS OF FOG (MOIST LOW LEVELS...HIGH PRESSURE TO THE NORTHEAST). HOWEVER...NAM MODEL SOUNDINGS SUGGEST THE THE LOW LEVEL HYDROLAPSE RATES DO NOT BECOME FAVORABLE FOR UNTIL LATER TONIGHT...AND FOR A SHORTER TIME THAT THE MOS GUIDANCE WOULD INDICATE. AREAS OF FOG WAS LEFT IN THE FORECAST...AND TRENDS WILL BE WATCHED TO LOOK FOR POTENTIAL FOR DENSE FOG LATER TONIGHT. FOR THE MOST PART...TEMPERATURES AND WINDS APPEAR TO BE ON TRACK FOR THE OVERNIGHT. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/... EXPECT PERIODS OF SHOWERS AND POSSIBLY THUNDERSTORMS DURG THE AFTN AND THEY MAY BE MORE WIDESPREAD THAN TODAY ESPECIALLY IF WE GET MORE BREAKS IN THE CLOUDS, BUT DON`T SEE ANY SIGNIFICANT FORCING MECHANISMS. GUID TEMPS LOOK REASONABLE ONCE AGAIN. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... THE WRF-NMMB INITIALIZATION WAS BETTER THAN THE GFS OFF OF THE 12Z SOUNDINGS AND THE FORMER WAS GIVEN MORE WEIGHT THAN AVERAGE TODAY. BTW TODAY IS THE FIRST DAY OF THE NEW GFS. IN THE BIG PICTURE, NO CHANGES TO OUR THINKING WITH MAINLY DIURNALLY DRIVEN LOCALIZED HEAVY RAIN CONVECTION INTO FRIDAY. THEN MODEL UNCERTAINTIES AS TO THE BACKDOOR ON THE WEEKEND WITH THE TREND TOWARD WARMER AND MORE HUMID WEATHER INCORPORATED. THERE SHOULD BE A DIURNAL DOWNTREND IN THE CONVECTION ON WEDNESDAY EVENING AS FORECAST CAPES AND LI(S) DECREASE. WE DID SHOW AN UPTICK IN POPS LATER AT NIGHT AS THE SHORT WAVE ASSOCIATED WITH THE CLOSING SERN CONUS LOW COMES CLOSE TO THE AREA. BOTH THE GFS AND WRF-NMMB DO SHOW SOME WEAK SFC BASED INSTABILITY AS THIS FEATURE SLIDES BY AND WE MENTION SOME THUNDER LATE. GIVEN THE CONTINUED UPTICK IN DEW POINTS, WE MAINTAINED THE MENTION OF PATCHY FOG LATE. A STAT GUIDANCE COMPROMISE WAS USED FOR MINS. ON THURSDAY, WE LEANED MORE TOWARD THE WRF-NMMB SOLUTION OF GIVING THE CANADIAN MARITIMES HIGH A BIT MORE OF A BITE AND SHELTERING OF OUR CWA FROM CONVECTION. IN REALITY GFS MOS SUPPORTS THE WRF-NMMB SFC FEATURES MORE SO THAN THE GFS ITSELF. BOTH WOULD FAVOR MORE ACTIVITY WEST VS EAST. CONCEIVABLY BEING RIGHT FOR THE WRONG REASON, THE GFS BRINGS IN DRY AIR ALOFT IN THE EAST DURING THE DAY ON THURSDAY WHICH WOULD MAKE IT HARDER FOR CONVECTION TO OCCUR. WITHOUT ANY ORGANIZED TRIGGER WITH THE AFOREMENTIONED SHORT WAVE MOVING FARTHER OFFSHORE IN THE MORNING, KEPT POPS AS CHANCE. GIVEN MORE OF AN ONSHORE INFLUENCE FROM THE SFC HIGH AND HOW LONG WILL IT TAKE TO CLEAR LOW CLOUDS, WE LEANED MAX TEMPS MUCH CLOSER TO THE LOWER NAM MOS THAN GFS MOS. WASH, RINSE, REPEAT ON THURSDAY NIGHT. BUT, WITHOUT A LATE SHORT WAVE, WE DROPPED POPS AS THE NIGHT PROGRESSES AND REMOVED THE MENTION OF THUNDER. THE WRF-NMMB SOLUTION SUPPORTS STRATUS AT THE LEAST AND A SUGGESTION OF DRIZZLE AT THE MOST AS THE .01 PCPN FIELD BOOMS LATE AT NIGHT. FOR NOW WE WENT THE PATCHY FOG ROUTE AND ACCEPTED THE STAT GUIDANCE MINS. ON FRIDAY, THE MODELS AGREE ON A SLIGHTLY MORE EAST PUSH IN THE INSTABILITY AXIS, MAYBE INTO THE DELAWARE VALLEY. OTHER THAN MESOSCALE FEATURES, I.E. DIFFERENTIAL HEATING, OROGRAPHIC LIFTING, MAYBE SEA OR BAY BREEZES, NOT MUCH ORGANIZATIONAL ACTIVITY EXPECTED AGAIN. POPS WERE AGAIN KEPT BELOW LIKELY. WE STILL PREFER MORE OF A MODIFIED MARINE INFLUENCE FROM OUR SURFACE HIGH TO THE EAST THAN THE GFS SHOWED AND WE THUS KEPT MAX TEMPS BLO MEX MOS. BOTH THE GFS AND WRF-NMMB DID SHOW AN AXIS OF HIGHER INSTABILITY WORKING ITS WAY INTO WESTERN PA DURING THE DAY ON FRIDAY. IF THE CONVECTION COULD MAINTAIN ITSELF, IT WOULD GET INTO OUR CWA BEFORE RUNNING OUT OF GAS ON FRIDAY NIGHT. WE DID UP POPS SLIGHTLY. THERE REMAINS SOME UNCERTAINTY AS TO HOW SOUTH WILL THE BACKDOOR FRONT GET OVER THE WEEKEND. RIGHT NOW IT APPEARS TO BE A DIFFERENCE BETWEEN WARM WEATHER AND SOME TYPICAL SUMMERTIME CONVECTION AROUND BECAUSE OF THE LINGERING FRONT, OR A COUPLE OF WARM SECTOR DAYS WITH HIGH TEMPERATURES REACHING THE 90S ON THE COASTAL PLAIN AWAY FROM THE OCEAN. THE MODELS CONTINUE TO GO BACK AND FORTH WITH THIS SCENARIO. MORE CONSENSUS ODDLY ABOUT HOT WEATHER ON MONDAY AND TUESDAY. WE NUDGED MAX TEMPS UPWARD WITH THIS PACKAGE AND MAINTAINED LOW POPS BECAUSE OF THE UNCERTAINTY OF THE FRONTAL POSITION. && .AVIATION /01Z WEDNESDAY THROUGH SUNDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. CONDITIONS REMAIN VFR EARLY THIS EVENING. SCATTERED SHOWERS DOT PORTIONS OF THE REGION...AND TERMINAL LOCATIONS NORTH AND WEST OF KPHL STAND THE BEST CHANCE OF SEEING LOCAL MVFR CONDITIONS IN SHOWERS THROUGH ABOUT 0300 UTC. THERE IS ALSO A LINE OF THUNDERSTORMS OVER WEST CENTRAL PENNSYLVANIA. NEAR TERM MODELS TRY TO BRING THIS ACTIVITY TO THE LEHIGH VALLEY BETWEEN 0300 UTC AND 0400 UTC...BUT THIS LOOKS OVERDONE. IN ANY EVENT...THUNDER WAS NOT CARRIED IN ANY OF THE NEW TERMINAL FORECASTS FOR THIS EVENING. THE LOWER LEVELS ARE NOT AS MOST AS THIS TIME MONDAY...SO THE RETURN OF THE STRATUS SHOULD BE DELAYED BY A COUPLE OF HOURS. IFR CONDITIONS ARE EXPECTED TO RETURN BETWEEN 0300 UTC AND 0600 UTC FROM EAST TO WEST. A PERIOD LIFR CONDITIONS IS EXPECTED BETWEEN 1000 UTC AND 1300 UTC AT ALL LOCATIONS. THERE IS A CHANCE VISIBILITIES COULD DROP TO NEAR 1/2SM FG BETWEEN 1000 UTC AND 1300 UTC...BUT CONFIDENCE IN THIS OCCURRING AT KPHL IS LOW AT THIS TIME. CONDITIONS SHOULD RISE BACK THROUGH IFR INTO MVFR BETWEEN 1400 UTC AND 1600 UTC...AND AFTER 1600 UTC...VFR CONDITIONS ARE EXPECTED. SCATTERED THUNDERSTORMS ARE POSSIBLE AFTER 1800 UTC WEDNESDAY...BUT DUE TO TIMING AND PLACEMENT QUESTIONS...THEY WERE NOT INCLUDED IN THE UPDATED TERMINAL FORECASTS AT THIS TIME. OUTLOOK... WEDNESDAY NIGHT THROUGH FRIDAY...IFR CONDS EACH NIGHT AND EARLY EACH DAY IN STRATUS AND/OR FOG BECOMING VFR IN THE AFTN. LOCAL IFR CONDS IN SHOWERS OR TSTMS. OUTLOOKING LESS COVERAGE AND DURATION OF IFR AND MVFR CONDITIONS ON FRIDAY THAN THURSDAY. SATURDAY AND SUNDAY...POSSIBLY SOME MVFR OR IFR STRATUS OR FOG EARLY OTHERWISE VFR. ISOLATED THUNDERSTORMS POSSIBLE MAINLY LATE EACH DAY WITH MVFR CONDITIONS. && .MARINE... THE LONG PERIOD SOUTHEASTERLY SWELLS ARE STARTING TO COME DOWN. BASED ON EXTRAPOLATION AND THE LATEST WNAWAVE OUTPUT...SEAS COULD DROP BELOW 5 FEET ACROSS SOUTHERN WATERS BEFORE 0600 UTC (44009 IS GETTING CLOSE). IF THIS OCCURS...THE CURRENT SMALL CRAFT ADVISORY FOR SEAS COULD BE DROPPED ACROSS THE SOUTHERN OCEAN WATERS EARLY. FURTHER NORTH...44065 IS STILL SHOWING SEAS NEAR 6 FEET...AND IT MAY TAKE UNTIL THE END OF THE CURRENT SMALL CRAFT ADVISORY (1000 UTC) FOR SEAS TO DROP BELOW SMALL CRAFT LEVELS THERE. SO...FOR THE TIME BEING...NO SIGNIFICANT CHANGES WERE MADE TO THE WAVE HEIGHT FOR THIS EVENING. MODEL SOUNDINGS SUGGEST THAT FOG COULD DEVELOP ACROSS THE OCEAN WATERS AFTER MIDNIGHT. THERE IS NOT MUCH HINT OF THIS YET ON SURFACE OBSERVATIONS OR LOW LEVEL CLOUD PRODUCT. SINCE THE LOW LEVELS ARE MOIST...BOUNDARY LAYER WINDS ARE LIGHT...AND DEW POINTS ARE JUST ABOUT AT THE SEA SURFACE TEMPERATURE...FOG IS STILL EXPECTED. OUTLOOK... WE ARE NOT EXPECTING SMALL CRAFT ADVISORY CONDITIONS TO OCCUR THROUGHOUT THE OUTLOOK PERIOD AS THE ONSHORE FLOW FROM THE CANADIAN MARITIMES SHOULD NOT BE THAT STRONG AND EVEN IF WE GET A BACKDOOR FRONT, WINDS ARE NOT EXPECTED TO BE STRONG EITHER. THE GREATER MARINE CONCERNS WILL BE FOG AS DEW POINTS SHOULD RISE ABOVE THE WATER TEMPS. THIS MAY THE CASE EVERY MORNING INTO SUNDAY. ALSO THERE MAY BE STRONGER WINDS NEAR THUNDERSTORMS, ALTHOUGH THE GREATEST INSTABILITY IS EXPECTED TO BE WEST OF THE COASTAL WATERS. && .HYDROLOGY... THERE WILL PROBABLY BE NARROW SWATHS OF 72 HOUR TOTAL 1-3 INCH RFALL BETWEEN TONIGHT AND FRIDAY...MAINLY IN E PA AND POSSIBLY NNJ. PWATS THIS WEEK AROUND 1.4 INCHES INCREASE TO AT LEAST 1.75 INCHES THIS WEEKEND. && .RIP CURRENTS... THE SOUTHEAST SWELL SHOULD BE DROPPING TONIGHT INTO WEDNESDAY. WHILE THE PERIOD REMAINS FAIRLY LONG (NEAR 9 SECONDS)...THE SURF HEIGHT SHOULD COME DOWN AS WELL. BASED ON THE ABOVE...OUR LOCAL STUDY SHOWS THE NEW JERSEY COAST COMING IN AT MODERATE...AND THE DELAWARE COAST COMING IN WITH A LOW RISK OF RIP CURRENTS WEDNESDAY. THE ABOVE WILL BE REFLECTED IN THE EVENING SURF ZONE FORECAST FOR WEDNESDAY. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT WEDNESDAY FOR ANZ450>455. && $$ SYNOPSIS...GIGI NEAR TERM...HAYES SHORT TERM...NIERENBERG LONG TERM...GIGI/99 AVIATION...GIGI/HAYES MARINE...GIGI/HAYES HYDROLOGY...DRAG RIP CURRENTS...HAYES
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
755 PM EDT TUE MAY 22 2012 .SYNOPSIS... A LOW PRESSURE SYSTEM SOUTHEAST OF CAPE COD WILL DRIFT NORTHEAST TONIGHT AND WEDNESDAY. A HIGH PRESSURE SYSTEM WILL THEN BUILD IN BEHIND IT OVER THE CANADIAN MARITIMES ON THURSDAY AND SLOWLY SINK SOUTHWEST OVER THE MEMORIAL DAY WEEKEND AND BECOME ESTABLISHED OFF THE SOUTHEAST UNITED STATES COAST. A BACKDOOR COLD FRONT WILL TRY TO SAG SOUTH INTO THE AREA ABOUT SUNDAY BEFORE RETREATING NORTH ON MEMORIAL DAY. A FRONT DOOR COLD FRONT WILL APPROACH THE AREA FROM THE GREAT LAKES ON TUESDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... THE MAIN FOCUS EARLY THIS EVENING HAS SHIFTED TO THE POTENTIAL FOR LOCALLY HEAVY RAIN. THE ENVIRONMENTAL WINDS ARE FAIRLY LIGHT...AND THIS IS RESULTING G A SLOW SOUTHEAST TRUNDLE TO THE SHOWERS. THE AIRMASS IS ALSO FAIRLY MOIST...WITH AN AXIS OF PRECIPITABLE WATER NEAR 1.50 INCHES RUNNING THROUGH SOUTHEAST PENNSYLVANIA INTO NORTHERN NEW JERSEY. THE COMBINATION OF SLOW MOVEMENT AND HIGH PRECIPITABLE WATER RAISES THE SPECTER OF LOCALIZED HEAVY RAIN. ONE HOUR GRIDDED FLASH FLOOD GUIDANCE SHOWS THAT 1.75 TO ABOUT 2.00 INCHES OF RAIN WOULD BE NEEDED TO INITIATE FLASH FLOODING. AS LONG AS THE CELLS KEEP MOVING...THE THREAT OF FLASH FLOODING SHOULD REMAIN LOW. HOWEVER...WE WILL CONTINUE TO MONITOR FOR THE POTENTIAL FOR THE REST OF THE EVENING. OTHERWISE...DESPITE BREAKS IN THE CLOUDS THIS AFTERNOON...THE SCATTERED SHOWER ACTIVITY HAS BEEN SLOW TO EVOLVE LATE THIS AFTERNOON. IN FACT...TOPS HAVE NOT GOTTEN TO MINUS 20 CELSIUS YET...AND THIS WOULD SEEM TO EXPLAIN THE LACK OF LIGHTNING DATA TO THIS POINT. THE LOSS OF DAYTIME HEATING SOON PROBABLY MEANS THE WINDOW OF OPPORTUNITY FOR THUNDER WITH THE SCATTERED SHOWERS DEVELOPING NOW IS CLOSING...AND COULD BE REMOVED FROM NORTHERN ZONES BEFORE 900 PM. THE LATEST HRRR RUN IS TRYING TO DEVELOP A BROKEN LINE OF THUNDERSTORMS IN THE BEST INSTABILITY. THIS LIES ACROSS WEST CENTRAL PENNSYLVANIA (WHERE THE SUNSHINE HAD A BETTER CHANCE TO DESTABILIZE THE AIRMASS. THE IN SITU BULK SHEAR PROFILE IS NOT THAT IMPRESSIVE...AND DOES NOT APPEAR TO GET ANY BETTER INTO THE LATER EVENING HOURS. WHILE THERE IS SOME ACTIVITY NOW IN THE AXIS OF BEST INSTABILITY...IT IS UNCLEAR JUST HOW MUCH OF THIS ACTIVITY SURVIVES TO THE LEHIGH VALLEY AFTER 800 PM. FOR NOW...WILL LEAVE THE MENTION OF THUNDER IN DEFERENCE TO THE ACTIVITY TO THE WEST. HOWEVER...IF IT DOES NOT GET BETTER ORGANIZED AS IT MOVES EAST...IT COULD BE REMOVED FROM THE FORECAST LATER TONIGHT. THE NEXT FORECAST PROBLEM FOR TONIGHT IS THE LOW CLOUDS AND FOG. THE LOW CLOUDS DID BREAK THIS AFTERNOON...AND PATCHES ARE TRYING TO REFORM EARLY THIS EVENING. NAM MODEL SOUNDINGS SHOW THAT THE REDEVELOPMENT OF STRATUS COULD TAKE SOME TIME...ESPECIALLY WEST OF THE DELAWARE RIVER. BASED ON THE CURRENT CLOUD COVER AND THE NAM MODEL SOUNDINGS...THE TIMING OF THE STRATUS REAPPEARANCE HAS BEEN PUSHED BACK A BIT. STATISTICAL GUIDANCE SUGGESTS THAT TONIGHT COULD END UP BEING A A BETTER SETUP FOR AREAS OF FOG (MOIST LOW LEVELS...HIGH PRESSURE TO THE NORTHEAST). HOWEVER...NAM MODEL SOUNDINGS SUGGEST THE THE LOW LEVEL HYDROLAPSE RATES DO NOT BECOME FAVORABLE FOR UNTIL LATER TONIGHT...AND FOR A SHORTER TIME THAT THE MOS GUIDANCE WOULD INDICATE. AREAS OF FOG WAS LEFT IN THE FORECAST...AND TRENDS WILL BE WATCHED TO LOOK FOR POTENTIAL FOR DENSE FOG LATER TONIGHT. FOR THE MOST PART...TEMPERATURES AND WINDS APPEAR TO BE ON TRACK FOR THE OVERNIGHT. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/... EXPECT PERIODS OF SHOWERS AND POSSIBLY THUNDERSTORMS DURG THE AFTN AND THEY MAY BE MORE WIDESPREAD THAN TODAY ESPECIALLY IF WE GET MORE BREAKS IN THE CLOUDS, BUT DON`T SEE ANY SIGNIFICANT FORCING MECHANISMS. GUID TEMPS LOOK REASONABLE ONCE AGAIN. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... THE WRF-NMMB INITIALIZATION WAS BETTER THAN THE GFS OFF OF THE 12Z SOUNDINGS AND THE FORMER WAS GIVEN MORE WEIGHT THAN AVERAGE TODAY. BTW TODAY IS THE FIRST DAY OF THE NEW GFS. IN THE BIG PICTURE, NO CHANGES TO OUR THINKING WITH MAINLY DIURNALLY DRIVEN LOCALIZED HEAVY RAIN CONVECTION INTO FRIDAY. THEN MODEL UNCERTAINTIES AS TO THE BACKDOOR ON THE WEEKEND WITH THE TREND TOWARD WARMER AND MORE HUMID WEATHER INCORPORATED. THERE SHOULD BE A DIURNAL DOWNTREND IN THE CONVECTION ON WEDNESDAY EVENING AS FORECAST CAPES AND LI(S) DECREASE. WE DID SHOW AN UPTICK IN POPS LATER AT NIGHT AS THE SHORT WAVE ASSOCIATED WITH THE CLOSING SERN CONUS LOW COMES CLOSE TO THE AREA. BOTH THE GFS AND WRF-NMMB DO SHOW SOME WEAK SFC BASED INSTABILITY AS THIS FEATURE SLIDES BY AND WE MENTION SOME THUNDER LATE. GIVEN THE CONTINUED UPTICK IN DEW POINTS, WE MAINTAINED THE MENTION OF PATCHY FOG LATE. A STAT GUIDANCE COMPROMISE WAS USED FOR MINS. ON THURSDAY, WE LEANED MORE TOWARD THE WRF-NMMB SOLUTION OF GIVING THE CANADIAN MARITIMES HIGH A BIT MORE OF A BITE AND SHELTERING OF OUR CWA FROM CONVECTION. IN REALITY GFS MOS SUPPORTS THE WRF-NMMB SFC FEATURES MORE SO THAN THE GFS ITSELF. BOTH WOULD FAVOR MORE ACTIVITY WEST VS EAST. CONCEIVABLY BEING RIGHT FOR THE WRONG REASON, THE GFS BRINGS IN DRY AIR ALOFT IN THE EAST DURING THE DAY ON THURSDAY WHICH WOULD MAKE IT HARDER FOR CONVECTION TO OCCUR. WITHOUT ANY ORGANIZED TRIGGER WITH THE AFOREMENTIONED SHORT WAVE MOVING FARTHER OFFSHORE IN THE MORNING, KEPT POPS AS CHANCE. GIVEN MORE OF AN ONSHORE INFLUENCE FROM THE SFC HIGH AND HOW LONG WILL IT TAKE TO CLEAR LOW CLOUDS, WE LEANED MAX TEMPS MUCH CLOSER TO THE LOWER NAM MOS THAN GFS MOS. WASH, RINSE, REPEAT ON THURSDAY NIGHT. BUT, WITHOUT A LATE SHORT WAVE, WE DROPPED POPS AS THE NIGHT PROGRESSES AND REMOVED THE MENTION OF THUNDER. THE WRF-NMMB SOLUTION SUPPORTS STRATUS AT THE LEAST AND A SUGGESTION OF DRIZZLE AT THE MOST AS THE .01 PCPN FIELD BOOMS LATE AT NIGHT. FOR NOW WE WENT THE PATCHY FOG ROUTE AND ACCEPTED THE STAT GUIDANCE MINS. ON FRIDAY, THE MODELS AGREE ON A SLIGHTLY MORE EAST PUSH IN THE INSTABILITY AXIS, MAYBE INTO THE DELAWARE VALLEY. OTHER THAN MESOSCALE FEATURES, I.E. DIFFERENTIAL HEATING, OROGRAPHIC LIFTING, MAYBE SEA OR BAY BREEZES, NOT MUCH ORGANIZATIONAL ACTIVITY EXPECTED AGAIN. POPS WERE AGAIN KEPT BELOW LIKELY. WE STILL PREFER MORE OF A MODIFIED MARINE INFLUENCE FROM OUR SURFACE HIGH TO THE EAST THAN THE GFS SHOWED AND WE THUS KEPT MAX TEMPS BLO MEX MOS. BOTH THE GFS AND WRF-NMMB DID SHOW AN AXIS OF HIGHER INSTABILITY WORKING ITS WAY INTO WESTERN PA DURING THE DAY ON FRIDAY. IF THE CONVECTION COULD MAINTAIN ITSELF, IT WOULD GET INTO OUR CWA BEFORE RUNNING OUT OF GAS ON FRIDAY NIGHT. WE DID UP POPS SLIGHTLY. THERE REMAINS SOME UNCERTAINTY AS TO HOW SOUTH WILL THE BACKDOOR FRONT GET OVER THE WEEKEND. RIGHT NOW IT APPEARS TO BE A DIFFERENCE BETWEEN WARM WEATHER AND SOME TYPICAL SUMMERTIME CONVECTION AROUND BECAUSE OF THE LINGERING FRONT, OR A COUPLE OF WARM SECTOR DAYS WITH HIGH TEMPERATURES REACHING THE 90S ON THE COASTAL PLAIN AWAY FROM THE OCEAN. THE MODELS CONTINUE TO GO BACK AND FORTH WITH THIS SCENARIO. MORE CONSENSUS ODDLY ABOUT HOT WEATHER ON MONDAY AND TUESDAY. WE NUDGED MAX TEMPS UPWARD WITH THIS PACKAGE AND MAINTAINED LOW POPS BECAUSE OF THE UNCERTAINTY OF THE FRONTAL POSITION. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. CONDITIONS REMAIN VFR EARLY THIS EVENING. SCATTERED SHOWERS DOT PORTIONS OF THE REGION...AND TERMINAL LOCATIONS NORTH AND WEST OF KPHL STAND THE BEST CHANCE OF SEEING LOCAL MVFR CONDITIONS IN SHOWERS THROUGH ABOUT 0300 UTC. THERE IS ALSO A LINE OF THUNDERSTORMS OVER WEST CENTRAL PENNSYLVANIA. NEAR TERM MODELS TRY TO BRING THIS ACTIVITY TO THE LEHIGH VALLEY BETWEEN 0300 UTC AND 0400 UTC...BUT THIS LOOKS OVERDONE. IN ANY EVENT...THUNDER WAS NOT CARRIED IN ANY OF THE NEW TERMINAL FORECASTS FOR THIS EVENING. THE LOWER LEVELS ARE NOT AS MOST AS THIS TIME MONDAY...SO THE RETURN OF THE STRATUS SHOULD BE DELAYED BY A COUPLE OF HOURS. IFR CONDITIONS ARE EXPECTED TO RETURN BETWEEN 0300 UTC AND 0600 UTC FROM EAST TO WEST. A PERIOD LIFR CONDITIONS IS EXPECTED BETWEEN 1000 UTC AND 1300 UTC AT ALL LOCATIONS. THERE IS A CHANCE VISIBILITIES COULD DROP TO NEAR 1/2SM FG BETWEEN 1000 UTC AND 1300 UTC...BUT CONFIDENCE IN THIS OCCURRING AT KPHL IS LOW AT THIS TIME. CONDITIONS SHOULD RISE BACK THROUGH IFR INTO MVFR BETWEEN 1400 UTC AND 1600 UTC...AND AFTER 1600 UTC...VFR CONDITIONS ARE EXPECTED. SCATTERED THUNDERSTORMS ARE POSSIBLE AFTER 1800 UTC WEDNESDAY...BUT DUE TO TIMING AND PLACEMENT QUESTIONS...THEY WERE NOT INCLUDED IN THE UPDATED TERMINAL FORECASTS AT THIS TIME. OUTLOOK... WEDNESDAY NIGHT THROUGH FRIDAY...IFR CONDS EACH NIGHT AND EARLY EACH DAY IN STRATUS AND/OR FOG BECOMING VFR IN THE AFTN. LOCAL IFR CONDS IN SHOWERS OR TSTMS. OUTLOOKING LESS COVERAGE AND DURATION OF IFR AND MVFR CONDITIONS ON FRIDAY THAN THURSDAY. SATURDAY AND SUNDAY...POSSIBLY SOME MVFR OR IFR STRATUS OR FOG EARLY OTHERWISE VFR. ISOLATED THUNDERSTORMS POSSIBLE MAINLY LATE EACH DAY WITH MVFR CONDITIONS. && .MARINE... THE PROLONGED ELY TO EVENTUALLY SELY WILL CONTINUE AND SEAS HAVE BEEN ABOVE SCA FOR MOST OF THE DAY. THIS WILL CONTINUE THROUGH THE NIGHT, BUT LTST GUIDANCE INDICATES THE SRN WATERS WILL RETREAT BELOW SCA VALUES ON WEDNESDAY. ACRS THE N, THINGS MAY LINGER LONGER. HOWEVER, FOR NOW, WILL LET THE PREV ISSUED SCA CONTINUE WITH NO CHANGES, BUT IT MAY NEED TO BE EXTENDED FOR A FEW HOURS, ESPECIALLY ACRS THE N. OUTLOOK... WE ARE NOT EXPECTING SMALL CRAFT ADVISORY CONDITIONS TO OCCUR THROUGHOUT THE OUTLOOK PERIOD AS THE ONSHORE FLOW FROM THE CANADIAN MARITIMES SHOULD NOT BE THAT STRONG AND EVEN IF WE GET A BACKDOOR FRONT, WINDS ARE NOT EXPECTED TO BE STRONG EITHER. THE GREATER MARINE CONCERNS WILL BE FOG AS DEW POINTS SHOULD RISE ABOVE THE WATER TEMPS. THIS MAY THE CASE EVERY MORNING INTO SUNDAY. ALSO THERE MAY BE STRONGER WINDS NEAR THUNDERSTORMS, ALTHOUGH THE GREATEST INSTABILITY IS EXPECTED TO BE WEST OF THE COASTAL WATERS. && .HYDROLOGY... THERE WILL PROBABLY BE NARROW SWATHS OF 72 HOUR TOTAL 1-3 INCH RFALL BETWEEN TONIGHT AND FRIDAY...MAINLY IN E PA AND POSSIBLY NNJ. PWATS THIS WEEK AROUND 1.4 INCHES INCREASE TO AT LEAST 1.75 INCHES THIS WEEKEND. && .RIP CURRENTS... THE SOUTHEAST SWELL SHOULD BE DROPPING TONIGHT INTO WEDNESDAY. WHILE THE PERIOD REMAINS FAIRLY LONG (NEAR 9 SECONDS)...THE SURF HEIGHT SHOULD COME DOWN AS WELL. BASED ON THE ABOVE...OUR LOCAL STUDY SHOWS THE NEW JERSEY COAST COMING IN AT MODERATE...AND THE DELAWARE COAST COMING IN WITH A LOW RISK OF RIP CURRENTS WEDNESDAY. THE ABOVE WILL BE REFLECTED IN THE EVENING SURF ZONE FORECAST FOR WEDNESDAY. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT WEDNESDAY FOR ANZ450>455. && $$ SYNOPSIS...GIGI NEAR TERM...HAYES/NIERENBERG SHORT TERM...NIERENBERG LONG TERM...GIGI/99 AVIATION...GIGI/HAYES/NIERENBERG MARINE...GIGI/NIERENBERG HYDROLOGY...DRAG RIP CURRENTS...HAYES
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
732 PM EDT TUE MAY 22 2012 .SYNOPSIS... A LOW PRESSURE SYSTEM SOUTHEAST OF CAPE COD WILL DRIFT NORTHEAST TONIGHT AND WEDNESDAY. A HIGH PRESSURE SYSTEM WILL THEN BUILD IN BEHIND IT OVER THE CANADIAN MARITIMES ON THURSDAY AND SLOWLY SINK SOUTHWEST OVER THE MEMORIAL DAY WEEKEND AND BECOME ESTABLISHED OFF THE SOUTHEAST UNITED STATES COAST. A BACKDOOR COLD FRONT WILL TRY TO SAG SOUTH INTO THE AREA ABOUT SUNDAY BEFORE RETREATING NORTH ON MEMORIAL DAY. A FRONT DOOR COLD FRONT WILL APPROACH THE AREA FROM THE GREAT LAKES ON TUESDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... DESPITE BREAKS IN THE CLOUDS THIS AFTERNOON...THE SCATTERED SHOWER ACTIVITY HAS BEEN SLOW TO EVOLVE LATE THIS AFTERNOON. IN FACT...TOPS HAVE NOT GOTTEN TO MINUS 20 CELSIUS YET...AND THIS WOULD SEEM TO EXPLAIN THE LACK OF LIGHTNING DATA TO THIS POINT. THE LOSS OF DAYTIME HEATING SOON PROBABLY MEANS THE WINDOW OF OPPORTUNITY FOR THUNDER WITH THE SCATTERED SHOWERS DEVELOPING NOW IS CLOSING...AND COULD BE REMOVED FROM NORTHERN ZONES BEFORE 900 PM. THE LATEST HRRR RUN IS TRYING TO DEVELOP A BROKEN LINE OF THUNDERSTORMS IN THE BEST INSTABILITY. THIS LIES ACROSS WEST CENTRAL PENNSYLVANIA (WHERE THE SUNSHINE HAD A BETTER CHANCE TO DESTABILIZE THE AIRMASS. THE IN SITU BULK SHEAR PROFILE IS NOT THAT IMPRESSIVE...AND DOES NOT APPEAR TO GET ANY BETTER INTO THE LATER EVENING HOURS. WHILE THERE IS SOME ACTIVITY NOW IN THE AXIS OF BEST INSTABILITY...IT IS UNCLEAR JUST HOW MUCH OF THIS ACTIVITY SURVIVES TO THE LEHIGH VALLEY AFTER 800 PM. FOR NOW...WILL LEAVE THE MENTION OF THUNDER IN DEFERENCE TO THE ACTIVITY TO THE WEST. HOWEVER...IF IT DOES NOT GET BETTER ORGANIZED AS IT MOVES EAST...IT COULD BE REMOVED FROM THE FORECAST LATER TONIGHT. THE NEXT FORECAST PROBLEM FOR TONIGHT IS THE LOW CLOUDS AND FOG. THE LOW CLOUDS DID BREAK THIS AFTERNOON...AND PATCHES ARE TRYING TO REFORM EARLY THIS EVENING. NAM MODEL SOUNDINGS SHOW THAT THE REDEVELOPMENT OF STRATUS COULD TAKE SOME TIME...ESPECIALLY WEST OF THE DELAWARE RIVER. BASED ON THE CURRENT CLOUD COVER AND THE NAM MODEL SOUNDINGS...THE TIMING OF THE STRATUS REAPPEARANCE HAS BEEN PUSHED BACK A BIT. STATISTICAL GUIDANCE SUGGESTS THAT TONIGHT COULD END UP BEING A A BETTER SETUP FOR AREAS OF FOG (MOIST LOW LEVELS...HIGH PRESSURE TO THE NORTHEAST). HOWEVER...NAM MODEL SOUNDINGS SUGGEST THE THE LOW LEVEL HYDROLAPSE RATES DO NOT BECOME FAVORABLE FOR UNTIL LATER TONIGHT...AND FOR A SHORTER TIME THAT THE MOS GUIDANCE WOULD INDICATE. AREAS OF FOG WAS LEFT IN THE FORECAST...AND TRENDS WILL BE WATCHED TO LOOK FOR POTENTIAL FOR DENSE FOG LATER TONIGHT. FOR THE MOST PART...TEMPERATURES AND WINDS APPEAR TO BE ON TRACK FOR THE OVERNIGHT. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/... EXPECT PERIODS OF SHOWERS AND POSSIBLY THUNDERSTORMS DURG THE AFTN AND THEY MAY BE MORE WIDESPREAD THAN TODAY ESPECIALLY IF WE GET MORE BREAKS IN THE CLOUDS, BUT DON`T SEE ANY SIGNIFICANT FORCING MECHANISMS. GUID TEMPS LOOK REASONABLE ONCE AGAIN. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... THE WRF-NMMB INITIALIZATION WAS BETTER THAN THE GFS OFF OF THE 12Z SOUNDINGS AND THE FORMER WAS GIVEN MORE WEIGHT THAN AVERAGE TODAY. BTW TODAY IS THE FIRST DAY OF THE NEW GFS. IN THE BIG PICTURE, NO CHANGES TO OUR THINKING WITH MAINLY DIURNALLY DRIVEN LOCALIZED HEAVY RAIN CONVECTION INTO FRIDAY. THEN MODEL UNCERTAINTIES AS TO THE BACKDOOR ON THE WEEKEND WITH THE TREND TOWARD WARMER AND MORE HUMID WEATHER INCORPORATED. THERE SHOULD BE A DIURNAL DOWNTREND IN THE CONVECTION ON WEDNESDAY EVENING AS FORECAST CAPES AND LI(S) DECREASE. WE DID SHOW AN UPTICK IN POPS LATER AT NIGHT AS THE SHORT WAVE ASSOCIATED WITH THE CLOSING SERN CONUS LOW COMES CLOSE TO THE AREA. BOTH THE GFS AND WRF-NMMB DO SHOW SOME WEAK SFC BASED INSTABILITY AS THIS FEATURE SLIDES BY AND WE MENTION SOME THUNDER LATE. GIVEN THE CONTINUED UPTICK IN DEW POINTS, WE MAINTAINED THE MENTION OF PATCHY FOG LATE. A STAT GUIDANCE COMPROMISE WAS USED FOR MINS. ON THURSDAY, WE LEANED MORE TOWARD THE WRF-NMMB SOLUTION OF GIVING THE CANADIAN MARITIMES HIGH A BIT MORE OF A BITE AND SHELTERING OF OUR CWA FROM CONVECTION. IN REALITY GFS MOS SUPPORTS THE WRF-NMMB SFC FEATURES MORE SO THAN THE GFS ITSELF. BOTH WOULD FAVOR MORE ACTIVITY WEST VS EAST. CONCEIVABLY BEING RIGHT FOR THE WRONG REASON, THE GFS BRINGS IN DRY AIR ALOFT IN THE EAST DURING THE DAY ON THURSDAY WHICH WOULD MAKE IT HARDER FOR CONVECTION TO OCCUR. WITHOUT ANY ORGANIZED TRIGGER WITH THE AFOREMENTIONED SHORT WAVE MOVING FARTHER OFFSHORE IN THE MORNING, KEPT POPS AS CHANCE. GIVEN MORE OF AN ONSHORE INFLUENCE FROM THE SFC HIGH AND HOW LONG WILL IT TAKE TO CLEAR LOW CLOUDS, WE LEANED MAX TEMPS MUCH CLOSER TO THE LOWER NAM MOS THAN GFS MOS. WASH, RINSE, REPEAT ON THURSDAY NIGHT. BUT, WITHOUT A LATE SHORT WAVE, WE DROPPED POPS AS THE NIGHT PROGRESSES AND REMOVED THE MENTION OF THUNDER. THE WRF-NMMB SOLUTION SUPPORTS STRATUS AT THE LEAST AND A SUGGESTION OF DRIZZLE AT THE MOST AS THE .01 PCPN FIELD BOOMS LATE AT NIGHT. FOR NOW WE WENT THE PATCHY FOG ROUTE AND ACCEPTED THE STAT GUIDANCE MINS. ON FRIDAY, THE MODELS AGREE ON A SLIGHTLY MORE EAST PUSH IN THE INSTABILITY AXIS, MAYBE INTO THE DELAWARE VALLEY. OTHER THAN MESOSCALE FEATURES, I.E. DIFFERENTIAL HEATING, OROGRAPHIC LIFTING, MAYBE SEA OR BAY BREEZES, NOT MUCH ORGANIZATIONAL ACTIVITY EXPECTED AGAIN. POPS WERE AGAIN KEPT BELOW LIKELY. WE STILL PREFER MORE OF A MODIFIED MARINE INFLUENCE FROM OUR SURFACE HIGH TO THE EAST THAN THE GFS SHOWED AND WE THUS KEPT MAX TEMPS BLO MEX MOS. BOTH THE GFS AND WRF-NMMB DID SHOW AN AXIS OF HIGHER INSTABILITY WORKING ITS WAY INTO WESTERN PA DURING THE DAY ON FRIDAY. IF THE CONVECTION COULD MAINTAIN ITSELF, IT WOULD GET INTO OUR CWA BEFORE RUNNING OUT OF GAS ON FRIDAY NIGHT. WE DID UP POPS SLIGHTLY. THERE REMAINS SOME UNCERTAINTY AS TO HOW SOUTH WILL THE BACKDOOR FRONT GET OVER THE WEEKEND. RIGHT NOW IT APPEARS TO BE A DIFFERENCE BETWEEN WARM WEATHER AND SOME TYPICAL SUMMERTIME CONVECTION AROUND BECAUSE OF THE LINGERING FRONT, OR A COUPLE OF WARM SECTOR DAYS WITH HIGH TEMPERATURES REACHING THE 90S ON THE COASTAL PLAIN AWAY FROM THE OCEAN. THE MODELS CONTINUE TO GO BACK AND FORTH WITH THIS SCENARIO. MORE CONSENSUS ODDLY ABOUT HOT WEATHER ON MONDAY AND TUESDAY. WE NUDGED MAX TEMPS UPWARD WITH THIS PACKAGE AND MAINTAINED LOW POPS BECAUSE OF THE UNCERTAINTY OF THE FRONTAL POSITION. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. CONDITIONS REMAIN VFR EARLY THIS EVENING. SCATTERED SHOWERS DOT PORTIONS OF THE REGION...AND TERMINAL LOCATIONS NORTH AND WEST OF KPHL STAND THE BEST CHANCE OF SEEING LOCAL MVFR CONDITIONS IN SHOWERS THROUGH ABOUT 0300 UTC. THERE IS ALSO A LINE OF THUNDERSTORMS OVER WEST CENTRAL PENNSYLVANIA. NEAR TERM MODELS TRY TO BRING THIS ACTIVITY TO THE LEHIGH VALLEY BETWEEN 0300 UTC AND 0400 UTC...BUT THIS LOOKS OVERDONE. IN ANY EVENT...THUNDER WAS NOT CARRIED IN ANY OF THE NEW TERMINAL FORECASTS FOR THIS EVENING. THE LOWER LEVELS ARE NOT AS MOST AS THIS TIME MONDAY...SO THE RETURN OF THE STRATUS SHOULD BE DELAYED BY A COUPLE OF HOURS. IFR CONDITIONS ARE EXPECTED TO RETURN BETWEEN 0300 UTC AND 0600 UTC FROM EAST TO WEST. A PERIOD LIFR CONDITIONS IS EXPECTED BETWEEN 1000 UTC AND 1300 UTC AT ALL LOCATIONS. THERE IS A CHANCE VISIBILITIES COULD DROP TO NEAR 1/2SM FG BETWEEN 1000 UTC AND 1300 UTC...BUT CONFIDENCE IN THIS OCCURRING AT KPHL IS LOW AT THIS TIME. CONDITIONS SHOULD RISE BACK THROUGH IFR INTO MVFR BETWEEN 1400 UTC AND 1600 UTC...AND AFTER 1600 UTC...VFR CONDITIONS ARE EXPECTED. SCATTERED THUNDERSTORMS ARE POSSIBLE AFTER 1800 UTC WEDNESDAY...BUT DUE TO TIMING AND PLACEMENT QUESTIONS...THEY WERE NOT INCLUDED IN THE UPDATED TERMINAL FORECASTS AT THIS TIME. OUTLOOK... WEDNESDAY NIGHT THROUGH FRIDAY...IFR CONDS EACH NIGHT AND EARLY EACH DAY IN STRATUS AND/OR FOG BECOMING VFR IN THE AFTN. LOCAL IFR CONDS IN SHOWERS OR TSTMS. OUTLOOKING LESS COVERAGE AND DURATION OF IFR AND MVFR CONDITIONS ON FRIDAY THAN THURSDAY. SATURDAY AND SUNDAY...POSSIBLY SOME MVFR OR IFR STRATUS OR FOG EARLY OTHERWISE VFR. ISOLATED THUNDERSTORMS POSSIBLE MAINLY LATE EACH DAY WITH MVFR CONDITIONS. && .MARINE... THE PROLONGED ELY TO EVENTUALLY SELY WILL CONTINUE AND SEAS HAVE BEEN ABOVE SCA FOR MOST OF THE DAY. THIS WILL CONTINUE THROUGH THE NIGHT, BUT LTST GUIDANCE INDICATES THE SRN WATERS WILL RETREAT BELOW SCA VALUES ON WEDNESDAY. ACRS THE N, THINGS MAY LINGER LONGER. HOWEVER, FOR NOW, WILL LET THE PREV ISSUED SCA CONTINUE WITH NO CHANGES, BUT IT MAY NEED TO BE EXTENDED FOR A FEW HOURS, ESPECIALLY ACRS THE N. OUTLOOK... WE ARE NOT EXPECTING SMALL CRAFT ADVISORY CONDITIONS TO OCCUR THROUGHOUT THE OUTLOOK PERIOD AS THE ONSHORE FLOW FROM THE CANADIAN MARITIMES SHOULD NOT BE THAT STRONG AND EVEN IF WE GET A BACKDOOR FRONT, WINDS ARE NOT EXPECTED TO BE STRONG EITHER. THE GREATER MARINE CONCERNS WILL BE FOG AS DEW POINTS SHOULD RISE ABOVE THE WATER TEMPS. THIS MAY THE CASE EVERY MORNING INTO SUNDAY. ALSO THERE MAY BE STRONGER WINDS NEAR THUNDERSTORMS, ALTHOUGH THE GREATEST INSTABILITY IS EXPECTED TO BE WEST OF THE COASTAL WATERS. && .HYDROLOGY... THERE WILL PROBABLY BE NARROW SWATHS OF 72 HOUR TOTAL 1-3 INCH RFALL BETWEEN TONIGHT AND FRIDAY...MAINLY IN E PA AND POSSIBLY NNJ. PWATS THIS WEEK AROUND 1.4 INCHES INCREASE TO AT LEAST 1.75 INCHES THIS WEEKEND. && .RIP CURRENTS... THE SOUTHEAST SWELL SHOULD BE DROPPING TONIGHT INTO WEDNESDAY. WHILE THE PERIOD REMAINS FAIRLY LONG (NEAR 9 SECONDS)...THE SURF HEIGHT SHOULD COME DOWN AS WELL. BASED ON THE ABOVE...OUR LOCAL STUDY SHOWS THE NEW JERSEY COAST COMING IN AT MODERATE...AND THE DELAWARE COAST COMING IN WITH A LOW RISK OF RIP CURRENTS WEDNESDAY. THE ABOVE WILL BE REFLECTED IN THE EVENING SURF ZONE FORECAST FOR WEDNESDAY. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT WEDNESDAY FOR ANZ450>455. && $$ SYNOPSIS...GIGI NEAR TERM...HAYES/NIERENBERG SHORT TERM...NIERENBERG LONG TERM...GIGI/99 AVIATION...GIGI/HAYES/NIERENBERG MARINE...GIGI/NIERENBERG HYDROLOGY...DRAG RIP CURRENTS...HAYES
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1105 AM CDT MON MAY 21 2012 .PREV DISCUSSION... 345 AM CDT 08Z SURFACE ANALYSIS DEPICTS LOW PRESSURE NORTHEAST OF THE LAKES ACROSS EASTERN ONTARIO...WITH ITS COLD FRONT TRAILING THROUGH INDIANA AND INTO THE BOOTHEEL OF MISSOURI. RAIN CONTINUES TO WEAKEN AND ERODE THROUGH THE FRONTAL ZONE...WITH JUST A FEW SCATTERED SHOWERS LINGERING ACROSS THE IL/IND STATE LINE INTO NORTHWEST INDIANA AT THIS TIME. SHORT TERM HIGH-RES GUIDANCE INDICATES PRECIP WILL CONTINUE TO WEAKEN AND DRIFT OFF TO THE EAST EARLY THIS MORNING WITH CLOUDS ALSO SLOWLY MOVING EAST. THUS WILL START OF THE FORECAST WITH A LOW POP ACROSS NORTHWEST INDIANA FOR LINGERING EARLY SHOWERS AND WILL HAVE MOSTLY CLOUDY THIS AM/BECOMING MOSTLY SUNNY LATER FOR MOST AREAS. AFTER HIGHS IN THE LOWER 90S AGAIN SUNDAY...TODAY WILL BE MUCH COOLER WITH TEMPS A GOOD 20-25 DEGREES LOWER. WINDS TURNING NORTH-NORTHEAST LATER THIS MORNING SHOULD LIMIT AREAS ALONG THE LAKE TO THE LOW-MID 60S...WITH LOWER 70S ACROSS THE FAR WESTERN CWA. AN ELONGATED AREA OF SURFACE HIGH PRESSURE WILL SPREAD SLOWLY EAST-SOUTHEAST FROM THE UPPER MIDWEST ACROSS THE WESTERN GREAT LAKES THROUGH TUESDAY...PROVIDING DRY/PLEASANT WEATHER WITH COOL NIGHTTIME TEMPS IN THE MID 40S-LOWER 50S...AND DAYTIME HIGHS IN THE LOW-MID 70S WITH 60S AGAIN ALONG THE LAKE. SOUTH-SOUTHEAST WINDS WILL STRENGTHEN TUESDAY NIGHT INTO WEDNESDAY AS THE SURFACE RIDGE MOVES OFF TO THE EAST AND AN AREA OF LOW PRESSURE LIFTS NORTHEAST ACROSS THE NORTHERN PLAINS. BREEZY WARM ADVECTION WILL PUSH TEMPS BACK INTO THE UPPER 70S/LOW 80S WEDNESDAY AND INTO THE MID-UPPER 80S THURSDAY AS BROAD UPPER TROUGH DEVELOPS OVER THE WESTERN CONUS AND DEVELOPS DEEP SOUTH-SOUTHWEST FLOW ALOFT. BOTH DAYS WILL FEATURE SOME MODEST LAKE COOLING ALONG THE NORTH SHORE...AS SFC WINDS MAINTAIN A SOUTHEASTERLY COMPONENT. LONGER RANGE MODELS ARE IN GOOD AGREEMENT IN DEPICTING A FAIRLY STOUT SHORT WAVE TROUGH AND ASSOCIATED SURFACE LOW WHICH EMERGE FROM THE WESTERN TROUGH AND LIFT ACROSS THE UPPER MIDWEST/NORTHERN LAKES IN THE LATE THURSDAY/FRIDAY PERIOD...AND EVENTUALLY TRAIL A COLD FRONT INTO THE FORECAST AREA FRIDAY. THERE ARE SOME DIFFERENCES AS TO HOW QUICKLY THIS OCCURS AND JUST HOW FAR SOUTH THE FRONT SETTLES BEFORE STALLING OUT FRIDAY NIGHT/SATURDAY. OVERALL HAVE BASED FORECAST ON SLIGHTLY SLOWER ECMWF RATHER THAN FASTER GFS SOLUTION AND THUS HAVE GENERALLY LOW CHANCE POPS THURSDAY NIGHT/FRIDAY ACROSS THE NORTHERN PORTIONS OF THE FORECAST AREA...AND COOLER TEMPS MAINLY FAR NORTH/ALONG THE LAKE FRIDAY. SATURDAY FEATURES A RELATIVELY LARGE THERMAL SPREAD WITH NORTHEAST FLOW OFF THE LAKE WITH FRONT STALLED OUT ACROSS CENTRAL IL/IND...WITH TEMPS RANGING FROM NEAR 90 FAR SOUTH CLOSE TO THE BOUNDARY TO THE MID 60S RIGHT AT THE LAKE SHORE. UPPER RIDGE THEN BEGINS TO BUILD ALOFT AS LOW LEVEL FRONT STALLS OUT...WITH FORECAST SOUNDINGS INDICATING RELATIVELY STRONG CAPPING WITH WARMING TEMPS ALOFT. FOR THIS REASON HAVE FOLLOWED THE DRIER ECMWF WITH RESPECT TO PRECIP/LACK THEREOF IN THE SATURDAY/SUNDAY PERIOD. WARM FRONT THEN LIFTS BACK NORTH/NORTHEAST SUNDAY...THOUGH MODELS DIFFER IN JUST HOW QUICKLY THIS OCCURS. WITH SOMEWHAT LOW CONFIDENCE AT THIS GREAT DISTANCE HAVE USED A BLEND OF ECMWF-GFS FRONTAL POSITION SUNDAY WHICH RESULTS IN KEEPING A SOUTHEASTERLY COMPONENT TO SFC WINDS ALONG NORTH SHORE ONCE AGAIN. WARM LOW LEVEL THERMAL FIELDS SUPPORT UPPER 80S/LOW 90S...WITH COOLER TEMPS ALONG THE IL LAKE SHORE. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * GUSTY NORTHWEST WINDS * MORNING MVFR CIGS ZEBIC //DISCUSSION...UPDATED 12Z... SURFACE COLD FRONT CONTINUES TO SHIFT THROUGH THE REGION THIS EVENING...ENDING PRECIP AND FLIPPING TO WINDS AROUND TO THE NORTH. MVFR CIGS ARE NOTED ACROSS MOST OF THE TRACON THIS MORNING...AND NOT EXPECTING ANYTING TO FALL LOWER THAN THE 023 TO 025 RANGE. DRY AIR IS QUICKLY ADVANCING...AND DESPITE A SUBSIDENCE INVERSION...SHOULD SEE THESE QUICKLY BREAK UP THIS MORNING IN THE 14 TO 15Z HOUR. WINDS ARE PROGGED TO REMAIN NORTHERLY AND FLOP TO THE NORTHEAST. CLIMATOLOGICALLY SPEAKING...WINDS TYPICALLY WONT STAY OUT OF THE NORTH...BUT SHIFT EAST OF NORTH. NOT THE MOST CONFIDENT IT WILL HAPPEN AT 15Z...BUT MORE CONFIDENT WITH WINDS TURNING TOWARDS 040 BY 20Z. LATEST RAP AND HRRR DATA ARE INDICATING HIGHER WIND GUSTS AND SUSPECT THAT ORD WILL SEE LOW 20 KT GUSTS THIS AFTERNOON WHILE GYY IS FLIRTING WITH 30 KT. SHEA //ORD AND MDW CONFIDENCE...UPDATED 16Z... * MODERATE TO HIGH CONFIDENCE ON CIG FORECAST * HIGH CONFIDENCE IN WIND FORECAST * HIGH CONFIDENCE IN DRY FORECAST ZEBIC //OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z... WEDNESDAY...VFR. THURSDAY...VFR. SLIGHT CHANCE OF SHRA/TSRA LATE. FRIDAY...VFR. SLIGHT CHANCE OF SHRA/TSRA. SATURDAY AND SUNDAY...VFR. SHEA && .MARINE... 334 AM CDT LOW PRESSURE CONTINUES TO LIFT INTO ONTARIO THIS MORNING...AND A COLD FRONT MOVED THROUGH. SHOWERS AND THUNDERSTORMS HAVE COME TO AN END AND SURFACE HIGH PRESSURE WILL BE SWINGING OVERHEAD. THE PRESSURE GRADIENT WILL REMAIN HIGH THROUGH THE MORNING HOURS AND ALLOW WIND GUSTS TO APPROACH 25 KT FOR MOST OF THE INDIANA NEARSHORE WATERS. NOT FULLY CONFIDENT THAT THE ILLINOIS ZONES WILL BE SPARED AND WILL INCLUDE LMZ742 /NORTHERLY ISLAND/ THROUGH MICHIGAN CITY. WINDS WILL ABATE THIS AFTERNOON BUT WAVES ARE EXPECTED TO REMAIN ABOVE CRITERIA THROUGH TOMORROW MORNING. HIGH PRESSURE WILL THEN DOMINATE THE PATTERN THROUGH MID WEEK...BEFORE STRONG SOUTHERLY FLOW RETURNS. SHEA && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 10 AM TUESDAY. SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 11 PM MONDAY. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
901 AM CDT MON MAY 21 2012 .PREV DISCUSSION... 345 AM CDT 08Z SURFACE ANALYSIS DEPICTS LOW PRESSURE NORTHEAST OF THE LAKES ACROSS EASTERN ONTARIO...WITH ITS COLD FRONT TRAILING THROUGH INDIANA AND INTO THE BOOTHEEL OF MISSOURI. RAIN CONTINUES TO WEAKEN AND ERODE THROUGH THE FRONTAL ZONE...WITH JUST A FEW SCATTERED SHOWERS LINGERING ACROSS THE IL/IND STATE LINE INTO NORTHWEST INDIANA AT THIS TIME. SHORT TERM HIGH-RES GUIDANCE INDICATES PRECIP WILL CONTINUE TO WEAKEN AND DRIFT OFF TO THE EAST EARLY THIS MORNING WITH CLOUDS ALSO SLOWLY MOVING EAST. THUS WILL START OF THE FORECAST WITH A LOW POP ACROSS NORTHWEST INDIANA FOR LINGERING EARLY SHOWERS AND WILL HAVE MOSTLY CLOUDY THIS AM/BECOMING MOSTLY SUNNY LATER FOR MOST AREAS. AFTER HIGHS IN THE LOWER 90S AGAIN SUNDAY...TODAY WILL BE MUCH COOLER WITH TEMPS A GOOD 20-25 DEGREES LOWER. WINDS TURNING NORTH-NORTHEAST LATER THIS MORNING SHOULD LIMIT AREAS ALONG THE LAKE TO THE LOW-MID 60S...WITH LOWER 70S ACROSS THE FAR WESTERN CWA. AN ELONGATED AREA OF SURFACE HIGH PRESSURE WILL SPREAD SLOWLY EAST-SOUTHEAST FROM THE UPPER MIDWEST ACROSS THE WESTERN GREAT LAKES THROUGH TUESDAY...PROVIDING DRY/PLEASANT WEATHER WITH COOL NIGHTTIME TEMPS IN THE MID 40S-LOWER 50S...AND DAYTIME HIGHS IN THE LOW-MID 70S WITH 60S AGAIN ALONG THE LAKE. SOUTH-SOUTHEAST WINDS WILL STRENGTHEN TUESDAY NIGHT INTO WEDNESDAY AS THE SURFACE RIDGE MOVES OFF TO THE EAST AND AN AREA OF LOW PRESSURE LIFTS NORTHEAST ACROSS THE NORTHERN PLAINS. BREEZY WARM ADVECTION WILL PUSH TEMPS BACK INTO THE UPPER 70S/LOW 80S WEDNESDAY AND INTO THE MID-UPPER 80S THURSDAY AS BROAD UPPER TROUGH DEVELOPS OVER THE WESTERN CONUS AND DEVELOPS DEEP SOUTH-SOUTHWEST FLOW ALOFT. BOTH DAYS WILL FEATURE SOME MODEST LAKE COOLING ALONG THE NORTH SHORE...AS SFC WINDS MAINTAIN A SOUTHEASTERLY COMPONENT. LONGER RANGE MODELS ARE IN GOOD AGREEMENT IN DEPICTING A FAIRLY STOUT SHORT WAVE TROUGH AND ASSOCIATED SURFACE LOW WHICH EMERGE FROM THE WESTERN TROUGH AND LIFT ACROSS THE UPPER MIDWEST/NORTHERN LAKES IN THE LATE THURSDAY/FRIDAY PERIOD...AND EVENTUALLY TRAIL A COLD FRONT INTO THE FORECAST AREA FRIDAY. THERE ARE SOME DIFFERENCES AS TO HOW QUICKLY THIS OCCURS AND JUST HOW FAR SOUTH THE FRONT SETTLES BEFORE STALLING OUT FRIDAY NIGHT/SATURDAY. OVERALL HAVE BASED FORECAST ON SLIGHTLY SLOWER ECMWF RATHER THAN FASTER GFS SOLUTION AND THUS HAVE GENERALLY LOW CHANCE POPS THURSDAY NIGHT/FRIDAY ACROSS THE NORTHERN PORTIONS OF THE FORECAST AREA...AND COOLER TEMPS MAINLY FAR NORTH/ALONG THE LAKE FRIDAY. SATURDAY FEATURES A RELATIVELY LARGE THERMAL SPREAD WITH NORTHEAST FLOW OFF THE LAKE WITH FRONT STALLED OUT ACROSS CENTRAL IL/IND...WITH TEMPS RANGING FROM NEAR 90 FAR SOUTH CLOSE TO THE BOUNDARY TO THE MID 60S RIGHT AT THE LAKE SHORE. UPPER RIDGE THEN BEGINS TO BUILD ALOFT AS LOW LEVEL FRONT STALLS OUT...WITH FORECAST SOUNDINGS INDICATING RELATIVELY STRONG CAPPING WITH WARMING TEMPS ALOFT. FOR THIS REASON HAVE FOLLOWED THE DRIER ECMWF WITH RESPECT TO PRECIP/LACK THEREOF IN THE SATURDAY/SUNDAY PERIOD. WARM FRONT THEN LIFTS BACK NORTH/NORTHEAST SUNDAY...THOUGH MODELS DIFFER IN JUST HOW QUICKLY THIS OCCURS. WITH SOMEWHAT LOW CONFIDENCE AT THIS GREAT DISTANCE HAVE USED A BLEND OF ECMWF-GFS FRONTAL POSITION SUNDAY WHICH RESULTS IN KEEPING A SOUTHEASTERLY COMPONENT TO SFC WINDS ALONG NORTH SHORE ONCE AGAIN. WARM LOW LEVEL THERMAL FIELDS SUPPORT UPPER 80S/LOW 90S...WITH COOLER TEMPS ALONG THE IL LAKE SHORE. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 14Z... * GUSTY NORTHWEST WINDS * MORNING MVFR CIGS ZEBIC //DISCUSSION...UPDATED 12Z... SURFACE COLD FRONT CONTINUES TO SHIFT THROUGH THE REGION THIS EVENING...ENDING PRECIP AND FLIPPING TO WINDS AROUND TO THE NORTH. MVFR CIGS ARE NOTED ACROSS MOST OF THE TRACON THIS MORNING...AND NOT EXPECTING ANYTING TO FALL LOWER THAN THE 023 TO 025 RANGE. DRY AIR IS QUICKLY ADVANCING...AND DESPITE A SUBSIDENCE INVERSION...SHOULD SEE THESE QUICKLY BREAK UP THIS MORNING IN THE 14 TO 15Z HOUR. WINDS ARE PROGGED TO REMAIN NORTHERLY AND FLOP TO THE NORTHEAST. CLIMATOLOGICALLY SPEAKING...WINDS TYPICALLY WONT STAY OUT OF THE NORTH...BUT SHIFT EAST OF NORTH. NOT THE MOST CONFIDENT IT WILL HAPPEN AT 15Z...BUT MORE CONFIDENT WITH WINDS TURNING TOWARDS 040 BY 20Z. LATEST RAP AND HRRR DATA ARE INDICATING HIGHER WIND GUSTS AND SUSPECT THAT ORD WILL SEE LOW 20 KT GUSTS THIS AFTERNOON WHILE GYY IS FLIRTING WITH 30 KT. SHEA //ORD AND MDW CONFIDENCE...UPDATED 14Z... * MODERATE TO HIGH CONFIDENCE ON CIG FORECAST * MODERATE TO HIGH CONFIDENCE IN WIND FORECAST * HIGH CONFIDENCE IN DRY FORECAST ZEBIC //OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z... WEDNESDAY...VFR. THURSDAY...VFR. SLIGHT CHANCE OF SHRA/TSRA LATE. FRIDAY...VFR. SLIGHT CHANCE OF SHRA/TSRA. SATURDAY AND SUNDAY...VFR. SHEA && .MARINE... 334 AM CDT LOW PRESSURE CONTINUES TO LIFT INTO ONTARIO THIS MORNING...AND A COLD FRONT MOVED THROUGH. SHOWERS AND THUNDERSTORMS HAVE COME TO AN END AND SURFACE HIGH PRESSURE WILL BE SWINGING OVERHEAD. THE PRESSURE GRADIENT WILL REMAIN HIGH THROUGH THE MORNING HOURS AND ALLOW WIND GUSTS TO APPROACH 25 KT FOR MOST OF THE INDIANA NEARSHORE WATERS. NOT FULLY CONFIDENT THAT THE ILLINOIS ZONES WILL BE SPARED AND WILL INCLUDE LMZ742 /NORTHERLY ISLAND/ THROUGH MICHIGAN CITY. WINDS WILL ABATE THIS AFTERNOON BUT WAVES ARE EXPECTED TO REMAIN ABOVE CRITERIA THROUGH TOMORROW MORNING. HIGH PRESSURE WILL THEN DOMINATE THE PATTERN THROUGH MID WEEK...BEFORE STRONG SOUTHERLY FLOW RETURNS. SHEA && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...LMZ742-LMZ743-LMZ744-LMZ745...1 PM MONDAY TO 10 AM TUESDAY. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
652 AM CDT MON MAY 21 2012 .DISCUSSION... 345 AM CDT 08Z SURFACE ANALYSIS DEPICTS LOW PRESSURE NORTHEAST OF THE LAKES ACROSS EASTERN ONTARIO...WITH ITS COLD FRONT TRAILING THROUGH INDIANA AND INTO THE BOOTHEEL OF MISSOURI. RAIN CONTINUES TO WEAKEN AND ERODE THROUGH THE FRONTAL ZONE...WITH JUST A FEW SCATTERED SHOWERS LINGERING ACROSS THE IL/IND STATE LINE INTO NORTHWEST INDIANA AT THIS TIME. SHORT TERM HIGH-RES GUIDANCE INDICATES PRECIP WILL CONTINUE TO WEAKEN AND DRIFT OFF TO THE EAST EARLY THIS MORNING WITH CLOUDS ALSO SLOWLY MOVING EAST. THUS WILL START OF THE FORECAST WITH A LOW POP ACROSS NORTHWEST INDIANA FOR LINGERING EARLY SHOWERS AND WILL HAVE MOSTLY CLOUDY THIS AM/BECOMING MOSTLY SUNNY LATER FOR MOST AREAS. AFTER HIGHS IN THE LOWER 90S AGAIN SUNDAY...TODAY WILL BE MUCH COOLER WITH TEMPS A GOOD 20-25 DEGREES LOWER. WINDS TURNING NORTH-NORTHEAST LATER THIS MORNING SHOULD LIMIT AREAS ALONG THE LAKE TO THE LOW-MID 60S...WITH LOWER 70S ACROSS THE FAR WESTERN CWA. AN ELONGATED AREA OF SURFACE HIGH PRESSURE WILL SPREAD SLOWLY EAST-SOUTHEAST FROM THE UPPER MIDWEST ACROSS THE WESTERN GREAT LAKES THROUGH TUESDAY...PROVIDING DRY/PLEASANT WEATHER WITH COOL NIGHTTIME TEMPS IN THE MID 40S-LOWER 50S...AND DAYTIME HIGHS IN THE LOW-MID 70S WITH 60S AGAIN ALONG THE LAKE. SOUTH-SOUTHEAST WINDS WILL STRENGTHEN TUESDAY NIGHT INTO WEDNESDAY AS THE SURFACE RIDGE MOVES OFF TO THE EAST AND AN AREA OF LOW PRESSURE LIFTS NORTHEAST ACROSS THE NORTHERN PLAINS. BREEZY WARM ADVECTION WILL PUSH TEMPS BACK INTO THE UPPER 70S/LOW 80S WEDNESDAY AND INTO THE MID-UPPER 80S THURSDAY AS BROAD UPPER TROUGH DEVELOPS OVER THE WESTERN CONUS AND DEVELOPS DEEP SOUTH-SOUTHWEST FLOW ALOFT. BOTH DAYS WILL FEATURE SOME MODEST LAKE COOLING ALONG THE NORTH SHORE...AS SFC WINDS MAINTAIN A SOUTHEASTERLY COMPONENT. LONGER RANGE MODELS ARE IN GOOD AGREEMENT IN DEPICTING A FAIRLY STOUT SHORT WAVE TROUGH AND ASSOCIATED SURFACE LOW WHICH EMERGE FROM THE WESTERN TROUGH AND LIFT ACROSS THE UPPER MIDWEST/NORTHERN LAKES IN THE LATE THURSDAY/FRIDAY PERIOD...AND EVENTUALLY TRAIL A COLD FRONT INTO THE FORECAST AREA FRIDAY. THERE ARE SOME DIFFERENCES AS TO HOW QUICKLY THIS OCCURS AND JUST HOW FAR SOUTH THE FRONT SETTLES BEFORE STALLING OUT FRIDAY NIGHT/SATURDAY. OVERALL HAVE BASED FORECAST ON SLIGHTLY SLOWER ECMWF RATHER THAN FASTER GFS SOLUTION AND THUS HAVE GENERALLY LOW CHANCE POPS THURSDAY NIGHT/FRIDAY ACROSS THE NORTHERN PORTIONS OF THE FORECAST AREA...AND COOLER TEMPS MAINLY FAR NORTH/ALONG THE LAKE FRIDAY. SATURDAY FEATURES A RELATIVELY LARGE THERMAL SPREAD WITH NORTHEAST FLOW OFF THE LAKE WITH FRONT STALLED OUT ACROSS CENTRAL IL/IND...WITH TEMPS RANGING FROM NEAR 90 FAR SOUTH CLOSE TO THE BOUNDARY TO THE MID 60S RIGHT AT THE LAKE SHORE. UPPER RIDGE THEN BEGINS TO BUILD ALOFT AS LOW LEVEL FRONT STALLS OUT...WITH FORECAST SOUNDINGS INDICATING RELATIVELY STRONG CAPPING WITH WARMING TEMPS ALOFT. FOR THIS REASON HAVE FOLLOWED THE DRIER ECMWF WITH RESPECT TO PRECIP/LACK THEREOF IN THE SATURDAY/SUNDAY PERIOD. WARM FRONT THEN LIFTS BACK NORTH/NORTHEAST SUNDAY...THOUGH MODELS DIFFER IN JUST HOW QUICKLY THIS OCCURS. WITH SOMEWHAT LOW CONFIDENCE AT THIS GREAT DISTANCE HAVE USED A BLEND OF ECMWF-GFS FRONTAL POSITION SUNDAY WHICH RESULTS IN KEEPING A SOUTHEASTERLY COMPONENT TO SFC WINDS ALONG NORTH SHORE ONCE AGAIN. WARM LOW LEVEL THERMAL FIELDS SUPPORT UPPER 80S/LOW 90S...WITH COOLER TEMPS ALONG THE IL LAKE SHORE. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 12Z... * GUSTY NORTHWEST WINDS * MORNING MVFR CIGYS SHEA //DISCUSSION...UPDATED 12Z... SURFACE COLD FRONT CONTINUES TO SHIFT THROUGH THE REGION THIS EVENING...ENDING PRECIP AND FLIPPING TO WINDS AROUND TO THE NORTH. MVFR CIGS ARE NOTED ACROSS MOST OF THE TRACON THIS MORNING...AND NOT EXPECTING ANYTING TO FALL LOWER THAN THE 023 TO 025 RANGE. DRY AIR IS QUICKLY ADVANCING...AND DESPITE A SUBSIDENCE INVERSION...SHOULD SEE THESE QUICKLY BREAK UP THIS MORNING IN THE 14 TO 15Z HOUR. WINDS ARE PROGGED TO REMAIN NORTHERLY AND FLOP TO THE NORTHEAST. CLIMATOLOGICALLY SPEAKING...WINDS TYPICALLY WONT STAY OUT OF THE NORTH...BUT SHIFT EAST OF NORTH. NOT THE MOST CONFIDENT IT WILL HAPPEN AT 15Z...BUT MORE CONFIDENT WITH WINDS TURNING TOWARDS 040 BY 20Z. LATEST RAP AND HRRR DATA ARE INDICATING HIGHER WIND GUSTS AND SUSPECT THAT ORD WILL SEE LOW 20 KT GUSTS THIS AFTERNOON WHILE GYY IS FLIRTING WITH 30 KT. SHEA //ORD AND MDW CONFIDENCE...UPDATED 12Z... * HIGH CONFIDENCE ON CIG FORECAST * MODERATE TO HIGH CONFIDENCE IN WIND FORECAST * HIGH CONFIDENCE IN DRY FORECAST SHEA //OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z... WEDNESDAY...VFR. THURSDAY...VFR. SLIGHT CHANCE OF SHRA/TSRA LATE. FRIDAY...VFR. SLIGHT CHANCE OF SHRA/TSRA. SATURDAY AND SUNDAY...VFR. SHEA && .MARINE... 334 AM CDT LOW PRESSURE CONTINUES TO LIFT INTO ONTARIO THIS MORNING...AND A COLD FRONT MOVED THROUGH. SHOWERS AND THUNDERSTORMS HAVE COME TO AN END AND SURFACE HIGH PRESSURE WILL BE SWINGING OVERHEAD. THE PRESSURE GRADIENT WILL REMAIN HIGH THROUGH THE MORNING HOURS AND ALLOW WIND GUSTS TO APPROACH 25 KT FOR MOST OF THE INDIANA NEARSHORE WATERS. NOT FULLY CONFIDENT THAT THE ILLINOIS ZONES WILL BE SPARED AND WILL INCLUDE LMZ742 /NORTHERLY ISLAND/ THROUGH MICHIGAN CITY. WINDS WILL ABATE THIS AFTERNOON BUT WAVES ARE EXPECTED TO REMAIN ABOVE CRITERIA THROUGH TOMORROW MORNING. HIGH PRESSURE WILL THEN DOMINATE THE PATTERN THROUGH MID WEEK...BEFORE STRONG SOUTHERLY FLOW RETURNS. SHEA && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...LMZ742-745...1 PM MONDAY TO 10 AM TUESDAY. && $$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1259 PM EDT MON MAY 21 2012 .UPDATE... AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 338 AM EDT MON MAY 21 2012 SCATTERED SHOWERS AND THUNDERSTORMS WILL GRADUALLY SHIFT EAST TODAY WITH A WEAK COLD FRONT...WITH DRY WEATHER RETURNING TONIGHT AS HIGH PRESSURE REESTABLISHES OVER THE REGION. AFTER A BRIEF COOLDOWN FOR TODAY AND TUESDAY...ARRIVAL OF RIDGING ALOFT AND SOUTHERLY FLOW WILL BRING A WARMING TREND BEGINNING ON WEDNESDAY. THE UPPER RIDGE WILL BECOME THE DOMINANT WEATHER FEATURE FOR THE OHIO VALLEY FOR LATE WEEK AND THE UPCOMING HOLIDAY WEEKEND...WITH DRY WEATHER AND THE HOTTEST TEMPERATURES OF THE YEAR SO FAR. && .NEAR TERM /REST OF TODAY/... ISSUED AT 922 AM EDT MON MAY 21 2012 ANALYSIS AS OF 915AM THIS MORNING DEPICTS A SURFACE COLD FRONT MOVING ACROSS THE WESTERN COUNTIES OF THE CWA EARLY THIS MORNING... THE PASSAGE OF THE FRONT WILL USHER IN MUCH DRIER AIR AND A SHIFT TO NORTHWEST WINDS AS IT PROGRESSES EAST THROUGH THE FORECAST AREA DURING THE COURSE OF THE DAY. CONVECTIVE COVERAGE CONTINUES TO DIMINISH EARLY THIS MORNING AS INSTABILITY WANES AND FORCING ALOFT IS LIMITED. CURRENT RAP INDICATING THAT CONVECTIVE COVERAGE WILL DECREASE OVER THE NEXT FEW HOURS...WITH RENEWED DEVELOPMENT MAINLY ALONG AND AHEAD OF THE INSTABILITY GRADIENT AND FRONTAL BOUNDARY BY MID/LATE MORNING OVER THE EASTERN HALF OF THE FORECAST AREA. HAVE FOCUSED HIGHEST POPS SOUTH AND EAST OF THE INDY METRO WHERE COMBINATION OF THE INSTABILITY AND DEEPEST MOISTURE AXIS SHOULD PROMOTE LARGELY DISORGANIZED AND SCATTERED CONVECTION INTO THE AFTERNOON. WILL MAINTAIN LOW CHANCE POPS OVER WESTERN COUNTIES THIS MORNING TO ACCOUNT FOR ANY ISOLATED DEVELOPMENT ALONG THE FRONT AS IT MOVES INTO THE AREA. HOWEVER...EXPECT AN OVERALL DRYING TREND FOR THE AFTERNOON AS MODEL GUIDANCE IN AGREEMENT ON MUCH DRIER AIR ADVECTING INTO THE REGION FROM THE WEST WITH A CAPPING INVERSION BECOMING WELL ESTABLISHED BY LATE DAY. AXIS OF DEEPER MOISTURE WILL SHIFT EAST INTO OHIO BY EARLY EVENING WITH ANY LINGERING PRECIP DEPARTING THE FORECAST AREA. TEMPS...COOLER DAY SETTING UP AS COLD ADVECTION COMMENCES WITH THE FRONTAL PASSAGE. CONSALL AND MAVMOS GUIDANCE MATCHED UP WELL WITH LOW LEVEL THERMALS WITH MOST LOCATIONS REMAINING IN THE 70S THIS AFTERNOON. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... ISSUED AT 338 AM EDT MON MAY 21 2012 FORECAST CHALLENGES FOCUS ON TEMPS THROUGH THE PERIOD AS A WARMING TREND COMMENCES BY WEDNESDAY WITH THE RETURN OF RIDGING ALOFT. UPPER TROUGH WILL SHARPEN AS IT PASSES THE FORECAST AREA TONIGHT... EVENTUALLY DEVELOPING AN UPPER LOW THAT WILL DIVE INTO THE SOUTHEAST STATES BY TUESDAY NIGHT. THIS WILL CAUSE DEEPER MOISTURE TO HOLD OVER THE EASTERN OHIO VALLEY AND THE SOUTHERN APPALACHIANS INTO WEDNESDAY AS THE UPPER LOW SLOWLY PINWHEELS EAST INTO THE CAROLINAS. THE ONLY IMPACTS TO CENTRAL INDIANA WILL BE TO ACCENTUATE CLOUD COVER INTO TUESDAY OVER EASTERN COUNTIES WHERE PRESENCE OF A LOW LEVEL THERMAL TROUGH LIKELY TO ENABLE A HEALTHY CU FIELD ON THE BACK SIDE OF THE MOISTURE PLUME. FURTHER WEST ACROSS THE FORECAST AREA... INCREASINGLY DEEPER SUBSIDENCE WILL FUNNEL INTO THE REGION WITH MOSTLY SUNNY SKIES EXPECTED. RIDGING ALOFT WILL STEADILY EXPAND INTO THE REGION TUESDAY NIGHT AND WEDNESDAY AS THE UPPER LOW MOVES EAST ACROSS THE SOUTHERN APPALACHIANS. PROGRESSIVELY DEEPER SUBSIDENCE WILL EXPAND ACROSS THE OHIO VALLEY ON WEDNESDAY AS RETURN SOUTHERLY FLOW SIGNALS THE ARRIVAL OF WARM ADVECTION. RESULT WILL BE MAINLY CLEAR SKIES WEDNESDAY AND WEDNESDAY NIGHT AND THE BEGINNING OF A WARMUP THAT WILL CONTINUE THROUGH THE REST OF THE WEEK. TEMPS...MOS GUIDANCE AND CONSALL MATCHED UP WELL ON TUESDAY WITH TEMPERATURES MAINLY IN THE MID 70S. LEANED CLOSER TO WARMER MAVMOS WEDNESDAY AS HIGHS RETURN TO THE 80S. POTENTIAL FOR TEMPS TO SLIP INTO THE UPPER 40S BOTH TONIGHT AND TUESDAY NIGHT IN RURAL LOCALES WITH 50S ELSEWHERE. && .LONG TERM /THURSDAY THROUGH SUNDAY/... ISSUED AT 338 AM EDT MON MAY 21 2012 MODELS STILL DIFFER IN THE EXTENDED ON HOW FAR SOUTH A COLD FRONT GETS INTO THE AREA FRIDAY AND SATURDAY. GFS IS THE OUTLIER AGAIN IN BRINGING IN THE COLD FRONT FARTHER SOUTH. EVEN GFS ENSEMBLE MEAN KEEPS FRONT TO THE NORTH...AND EXPERIMENTAL GFS ENSEMBLE CONFIDENCE PLOTS SHOW LOW TO VERY LOW CONFIDENCE IN GFS TEMPERATURES BY NEXT WEEKEND. THUS WILL THROW OUT GFS AND GO CLOSER TO ECMWF AGAIN WITH THIS PACKAGE. THE ABOVE MEANS RAISING ALLBLEND TEMPERATURES NEXT WEEKEND AND REMOVING ANY CHANCES FOR RAIN THAT IT GIVES. ALSO ADJUSTED ALLBLEND DEWPOINTS AND SKY COVER AS NECESSARY. UPPER HIGH WILL MOVE INTO THE AREA LATE IN THE WEEK AND PERSIST INTO THE WEEKEND. THIS WILL RESULT IN HOT CONDITIONS FOR THE HOLIDAY WEEKEND WITH NO RAIN EXPECTED. DEWPOINTS AND THUS RESULTANT HEAT INDEX VALUES ARE MORE UNCERTAIN DUE TO LACK OF WIDESPREAD SIGNIFICANT RAINFALL RECENTLY. CONDITIONS WILL STILL BE VERY WARM REGARDLESS SO WILL CONTINUE TO MENTION HEAT IN HWO. && .AVIATION /DISCUSSION FOR THE 211800Z TAFS ISSUANCE/... ISSUED AT 1259 PM EDT MON MAY 21 2012 COLD FRONT CURRENTLY OVER EASTERN CENTRAL AND SOUTHERN INDIANA WILL WILL CONTINUE MOVING EAST. AREAS OF MVFR CEILINGS HAVE DEVELOPED BEHIND COLD FRONT AND WAS CURRENTLY LIMITING CEILINGS ALL EXCEPT KIND. WITH SOME DAYTIME HEATING...EXPECT CEILINGS TO RISE TO VFR CATEGORY IN A FEW HOURS. BUT CEILINGS MAY REMAIN BARELY ABOVE 3 THOUSAND FEET AS THERE IS AN EXTENSIVE AREA OF CU UPSTREAM ACROSS EASTERN ILLINOIS. DRIER AIR WILL SPREAD INTO WESTERN SECTIONS BY EVENING AND OVER MOST OF THE REMAINING AREA LATER TONIGHT. EXPECT CLOUDS TO SCATTER OUT MOST AREAS BY EVENING AND EVEN BECOME CLEAR AT KHUF AND KLAF BY MIDNIGHT. MODELS KEEP SOME LOW LEVEL MOISTURE ACROSS THE SOUTHEAST HALF OF INDIANA INDIANA INTO TUESDAY...SO ANY CLEARING AT KIND AND KBMG MAY NOT OCCUR UNTIL NEAR OR AFTER THE END OF THE FORECAST PERIOD. NORTH TO NORTHWEST WINDS WILL INCREASE TO 10 TO 15 KNOTS THIS AFTERNOON AND DROP TO 8 KNOTS OR LESS TONIGHT. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN/SMF SHORT TERM...RYAN LONG TERM....50 AVIATION...JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1032 AM EDT MON MAY 21 2012 .UPDATE... AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 338 AM EDT MON MAY 21 2012 SCATTERED SHOWERS AND THUNDERSTORMS WILL GRADUALLY SHIFT EAST TODAY WITH A WEAK COLD FRONT...WITH DRY WEATHER RETURNING TONIGHT AS HIGH PRESSURE REESTABLISHES OVER THE REGION. AFTER A BRIEF COOLDOWN FOR TODAY AND TUESDAY...ARRIVAL OF RIDGING ALOFT AND SOUTHERLY FLOW WILL BRING A WARMING TREND BEGINNING ON WEDNESDAY. THE UPPER RIDGE WILL BECOME THE DOMINANT WEATHER FEATURE FOR THE OHIO VALLEY FOR LATE WEEK AND THE UPCOMING HOLIDAY WEEKEND...WITH DRY WEATHER AND THE HOTTEST TEMPERATURES OF THE YEAR SO FAR. && .NEAR TERM /REST OF TODAY/... ISSUED AT 922 AM EDT MON MAY 21 2012 ANALYSIS AS OF 915AM THIS MORING DEPICTS A SURFACE COLD FRONT MOVING ACROSS THE WESTERN COUNTIES OF THE CWA EARLY THIS MORNING... THE PASSAGE OF THE FRONT WILL USHER IN MUCH DRIER AIR AND A SHIFT TO NORTHWEST WINDS AS IT PROGRESSES EAST THROUGH THE FORECAST AREA DURING THE COURSE OF THE DAY. CONVECTIVE COVERAGE CONTINUES TO DIMINISH EARLY THIS MORNING AS INSTABILITY WANES AND FORCING ALOFT IS LIMITED. CURRENT RAP INDICATING THAT CONVECTIVE COVERAGE WILL DECREASE OVER THE NEXT FEW HOURS...WITH RENEWED DEVELOPMENT MAINLY ALONG AND AHEAD OF THE INSTABILITY GRADIENT AND FRONTAL BOUNDARY BY MID/LATE MORNING OVER THE EASTERN HALF OF THE FORECAST AREA. HAVE FOCUSED HIGHEST POPS SOUTH AND EAST OF THE INDY METRO WHERE COMBINATION OF THE INSTABILITY AND DEEPEST MOISTURE AXIS SHOULD PROMOTE LARGELY DISORGANIZED AND SCATTERED CONVECTION INTO THE AFTERNOON. WILL MAINTAIN LOW CHANCE POPS OVER WESTERN COUNTIES THIS MORNING TO ACCOUNT FOR ANY ISOLATED DEVELOPMENT ALONG THE FRONT AS IT MOVES INTO THE AREA. HOWEVER...EXPECT AN OVERALL DRYING TREND FOR THE AFTERNOON AS MODEL GUIDANCE IN AGREEMENT ON MUCH DRIER AIR ADVECTING INTO THE REGION FROM THE WEST WITH A CAPPING INVERSION BECOMING WELL ESTABLISHED BY LATE DAY. AXIS OF DEEPER MOISTURE WILL SHIFT EAST INTO OHIO BY EARLY EVENING WITH ANY LINGERING PRECIP DEPARTING THE FORECAST AREA. TEMPS...COOLER DAY SETTING UP AS COLD ADVECTION COMMENCES WITH THE FRONTAL PASSAGE. CONSALL AND MAVMOS GUIDANCE MATCHED UP WELL WITH LOW LEVEL THERMALS WITH MOST LOCATIONS REMAINING IN THE 70S THIS AFTERNOON. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... ISSUED AT 338 AM EDT MON MAY 21 2012 FORECAST CHALLENGES FOCUS ON TEMPS THROUGH THE PERIOD AS A WARMING TREND COMMENCES BY WEDNESDAY WITH THE RETURN OF RIDGING ALOFT. UPPER TROUGH WILL SHARPEN AS IT PASSES THE FORECAST AREA TONIGHT... EVENTUALLY DEVELOPING AN UPPER LOW THAT WILL DIVE INTO THE SOUTHEAST STATES BY TUESDAY NIGHT. THIS WILL CAUSE DEEPER MOISTURE TO HOLD OVER THE EASTERN OHIO VALLEY AND THE SOUTHERN APPALACHIANS INTO WEDNESDAY AS THE UPPER LOW SLOWLY PINWHEELS EAST INTO THE CAROLINAS. THE ONLY IMPACTS TO CENTRAL INDIANA WILL BE TO ACCENTUATE CLOUD COVER INTO TUESDAY OVER EASTERN COUNTIES WHERE PRESENCE OF A LOW LEVEL THERMAL TROUGH LIKELY TO ENABLE A HEALTHY CU FIELD ON THE BACK SIDE OF THE MOISTURE PLUME. FURTHER WEST ACROSS THE FORECAST AREA... INCREASINGLY DEEPER SUBSIDENCE WILL FUNNEL INTO THE REGION WITH MOSTLY SUNNY SKIES EXPECTED. RIDGING ALOFT WILL STEADILY EXPAND INTO THE REGION TUESDAY NIGHT AND WEDNESDAY AS THE UPPER LOW MOVES EAST ACROSS THE SOUTHERN APPALACHIANS. PROGRESSIVELY DEEPER SUBSIDENCE WILL EXPAND ACROSS THE OHIO VALLEY ON WEDNESDAY AS RETURN SOUTHERLY FLOW SIGNALS THE ARRIVAL OF WARM ADVECTION. RESULT WILL BE MAINLY CLEAR SKIES WEDNESDAY AND WEDNESDAY NIGHT AND THE BEGINNING OF A WARMUP THAT WILL CONTINUE THROUGH THE REST OF THE WEEK. TEMPS...MOS GUIDANCE AND CONSALL MATCHED UP WELL ON TUESDAY WITH TEMPERATURES MAINLY IN THE MID 70S. LEANED CLOSER TO WARMER MAVMOS WEDNESDAY AS HIGHS RETURN TO THE 80S. POTENTIAL FOR TEMPS TO SLIP INTO THE UPPER 40S BOTH TONIGHT AND TUESDAY NIGHT IN RURAL LOCALES WITH 50S ELSEWHERE. && .LONG TERM /THURSDAY THROUGH SUNDAY/... ISSUED AT 338 AM EDT MON MAY 21 2012 MODELS STILL DIFFER IN THE EXTENDED ON HOW FAR SOUTH A COLD FRONT GETS INTO THE AREA FRIDAY AND SATURDAY. GFS IS THE OUTLIER AGAIN IN BRINGING IN THE COLD FRONT FARTHER SOUTH. EVEN GFS ENSEMBLE MEAN KEEPS FRONT TO THE NORTH...AND EXPERIMENTAL GFS ENSEMBLE CONFIDENCE PLOTS SHOW LOW TO VERY LOW CONFIDENCE IN GFS TEMPERATURES BY NEXT WEEKEND. THUS WILL THROW OUT GFS AND GO CLOSER TO ECMWF AGAIN WITH THIS PACKAGE. THE ABOVE MEANS RAISING ALLBLEND TEMPERATURES NEXT WEEKEND AND REMOVING ANY CHANCES FOR RAIN THAT IT GIVES. ALSO ADJUSTED ALLBLEND DEWPOINTS AND SKY COVER AS NECESSARY. UPPER HIGH WILL MOVE INTO THE AREA LATE IN THE WEEK AND PERSIST INTO THE WEEKEND. THIS WILL RESULT IN HOT CONDITIONS FOR THE HOLIDAY WEEKEND WITH NO RAIN EXPECTED. DEWPOINTS AND THUS RESULTANT HEAT INDEX VALUES ARE MORE UNCERTAIN DUE TO LACK OF WIDESPREAD SIGNIFICANT RAINFALL RECENTLY. CONDITIONS WILL STILL BE VERY WARM REGARDLESS SO WILL CONTINUE TO MENTION HEAT IN HWO. && .AVIATION /DISCUSSION FOR THE 211500Z KIND TAF UPDATE/... ISSUED AT 1032 AM EDT MON MAY 21 2012 MINOR TEAKS MADE TO KIND TAF PER OBSERVATIONS UPSTREAM. OTHERWISE...NO OTHER CHANGES NEEDED AT THIS TIME. PREVIOUS AVIATION DISCUSSION FOLLOWS... MOSTLY VFR CONDITIONS THIS PERIOD...BUT MVFR POSSIBLE THROUGH THE FIRST SEVERAL HOURS OF THE TAF PERIOD. A COLD FRONT WILL SLOWLY WORK ACROSS THE SITES TODAY FROM WEST TO EAST. UNTIL IT PASSES...SCATTERED SHOWERS ARE POSSIBLE. PLACED VCSH AT KIND/KBMG WHERE BEST CHANCES FOR SHOWERS WILL BE. CURRENT LOCAL AND UPSTREAM OBSERVATIONS SHOW PATCHY MVFR CEILINGS AND VISIBILITIES IN FOG. DO NOT SEE WIDESPREAD CONDITIONS AT THE MOMENT...SO WILL NOT PUT MVFR AS PREDOMINANT IN THE FORECAST. HOWEVER POTENTIAL EXISTS FOR PERIODS OF CEILINGS AROUND 2000FT EARLY IN THE TAF PERIOD. CLOUDS WILL SCATTER OUT THIS AFTERNOON AS DRIER AIR WORKS IN. OVERNIGHT IT APPEARS SOME MOISTURE MAY RETURN TO THE EASTERN SITES...SO KEPT A SCATTERED LAYER AROUND 3000FT. WINDS WILL BECOME NORTH-NORTHWEST AND INCREASE INTO THE 10-15KT RANGE TODAY. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN/SMF SHORT TERM...RYAN LONG TERM....50 AVIATION...50/JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
926 AM EDT MON MAY 21 2012 .UPDATE... THE NEAR TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 338 AM EDT MON MAY 21 2012 SCATTERED SHOWERS AND THUNDERSTORMS WILL GRADUALLY SHIFT EAST TODAY WITH A WEAK COLD FRONT...WITH DRY WEATHER RETURNING TONIGHT AS HIGH PRESSURE REESTABLISHES OVER THE REGION. AFTER A BRIEF COOLDOWN FOR TODAY AND TUESDAY...ARRIVAL OF RIDGING ALOFT AND SOUTHERLY FLOW WILL BRING A WARMING TREND BEGINNING ON WEDNESDAY. THE UPPER RIDGE WILL BECOME THE DOMINANT WEATHER FEATURE FOR THE OHIO VALLEY FOR LATE WEEK AND THE UPCOMING HOLIDAY WEEKEND...WITH DRY WEATHER AND THE HOTTEST TEMPERATURES OF THE YEAR SO FAR. && .NEAR TERM /REST OF TODAY/... ISSUED AT 922 AM EDT MON MAY 21 2012 ANALYSIS AS OF 915AM THIS MORING DEPICTS A SURFACE COLD FRONT MOVING ACROSS THE WESTERN COUNTIES OF THE CWA EARLY THIS MORNING... THE PASSAGE OF THE FRONT WILL USHER IN MUCH DRIER AIR AND A SHIFT TO NORTHWEST WINDS AS IT PROGRESSES EAST THROUGH THE FORECAST AREA DURING THE COURSE OF THE DAY. CONVECTIVE COVERAGE CONTINUES TO DIMINISH EARLY THIS MORNING AS INSTABILITY WANES AND FORCING ALOFT IS LIMITED. CURRENT RAP INDICATING THAT CONVECTIVE COVERAGE WILL DECREASE OVER THE NEXT FEW HOURS...WITH RENEWED DEVELOPMENT MAINLY ALONG AND AHEAD OF THE INSTABILITY GRADIENT AND FRONTAL BOUNDARY BY MID/LATE MORNING OVER THE EASTERN HALF OF THE FORECAST AREA. HAVE FOCUSED HIGHEST POPS SOUTH AND EAST OF THE INDY METRO WHERE COMBINATION OF THE INSTABILITY AND DEEPEST MOISTURE AXIS SHOULD PROMOTE LARGELY DISORGANIZED AND SCATTERED CONVECTION INTO THE AFTERNOON. WILL MAINTAIN LOW CHANCE POPS OVER WESTERN COUNTIES THIS MORNING TO ACCOUNT FOR ANY ISOLATED DEVELOPMENT ALONG THE FRONT AS IT MOVES INTO THE AREA. HOWEVER...EXPECT AN OVERALL DRYING TREND FOR THE AFTERNOON AS MODEL GUIDANCE IN AGREEMENT ON MUCH DRIER AIR ADVECTING INTO THE REGION FROM THE WEST WITH A CAPPING INVERSION BECOMING WELL ESTABLISHED BY LATE DAY. AXIS OF DEEPER MOISTURE WILL SHIFT EAST INTO OHIO BY EARLY EVENING WITH ANY LINGERING PRECIP DEPARTING THE FORECAST AREA. TEMPS...COOLER DAY SETTING UP AS COLD ADVECTION COMMENCES WITH THE FRONTAL PASSAGE. CONSALL AND MAVMOS GUIDANCE MATCHED UP WELL WITH LOW LEVEL THERMALS WITH MOST LOCATIONS REMAINING IN THE 70S THIS AFTERNOON. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... ISSUED AT 338 AM EDT MON MAY 21 2012 FORECAST CHALLENGES FOCUS ON TEMPS THROUGH THE PERIOD AS A WARMING TREND COMMENCES BY WEDNESDAY WITH THE RETURN OF RIDGING ALOFT. UPPER TROUGH WILL SHARPEN AS IT PASSES THE FORECAST AREA TONIGHT... EVENTUALLY DEVELOPING AN UPPER LOW THAT WILL DIVE INTO THE SOUTHEAST STATES BY TUESDAY NIGHT. THIS WILL CAUSE DEEPER MOISTURE TO HOLD OVER THE EASTERN OHIO VALLEY AND THE SOUTHERN APPALACHIANS INTO WEDNESDAY AS THE UPPER LOW SLOWLY PINWHEELS EAST INTO THE CAROLINAS. THE ONLY IMPACTS TO CENTRAL INDIANA WILL BE TO ACCENTUATE CLOUD COVER INTO TUESDAY OVER EASTERN COUNTIES WHERE PRESENCE OF A LOW LEVEL THERMAL TROUGH LIKELY TO ENABLE A HEALTHY CU FIELD ON THE BACK SIDE OF THE MOISTURE PLUME. FURTHER WEST ACROSS THE FORECAST AREA... INCREASINGLY DEEPER SUBSIDENCE WILL FUNNEL INTO THE REGION WITH MOSTLY SUNNY SKIES EXPECTED. RIDGING ALOFT WILL STEADILY EXPAND INTO THE REGION TUESDAY NIGHT AND WEDNESDAY AS THE UPPER LOW MOVES EAST ACROSS THE SOUTHERN APPALACHIANS. PROGRESSIVELY DEEPER SUBSIDENCE WILL EXPAND ACROSS THE OHIO VALLEY ON WEDNESDAY AS RETURN SOUTHERLY FLOW SIGNALS THE ARRIVAL OF WARM ADVECTION. RESULT WILL BE MAINLY CLEAR SKIES WEDNESDAY AND WEDNESDAY NIGHT AND THE BEGINNING OF A WARMUP THAT WILL CONTINUE THROUGH THE REST OF THE WEEK. TEMPS...MOS GUIDANCE AND CONSALL MATCHED UP WELL ON TUESDAY WITH TEMPERATURES MAINLY IN THE MID 70S. LEANED CLOSER TO WARMER MAVMOS WEDNESDAY AS HIGHS RETURN TO THE 80S. POTENTIAL FOR TEMPS TO SLIP INTO THE UPPER 40S BOTH TONIGHT AND TUESDAY NIGHT IN RURAL LOCALES WITH 50S ELSEWHERE. && .LONG TERM /THURSDAY THROUGH SUNDAY/... ISSUED AT 338 AM EDT MON MAY 21 2012 MODELS STILL DIFFER IN THE EXTENDED ON HOW FAR SOUTH A COLD FRONT GETS INTO THE AREA FRIDAY AND SATURDAY. GFS IS THE OUTLIER AGAIN IN BRINGING IN THE COLD FRONT FARTHER SOUTH. EVEN GFS ENSEMBLE MEAN KEEPS FRONT TO THE NORTH...AND EXPERIMENTAL GFS ENSEMBLE CONFIDENCE PLOTS SHOW LOW TO VERY LOW CONFIDENCE IN GFS TEMPERATURES BY NEXT WEEKEND. THUS WILL THROW OUT GFS AND GO CLOSER TO ECMWF AGAIN WITH THIS PACKAGE. THE ABOVE MEANS RAISING ALLBLEND TEMPERATURES NEXT WEEKEND AND REMOVING ANY CHANCES FOR RAIN THAT IT GIVES. ALSO ADJUSTED ALLBLEND DEWPOINTS AND SKY COVER AS NECESSARY. UPPER HIGH WILL MOVE INTO THE AREA LATE IN THE WEEK AND PERSIST INTO THE WEEKEND. THIS WILL RESULT IN HOT CONDITIONS FOR THE HOLIDAY WEEKEND WITH NO RAIN EXPECTED. DEWPOINTS AND THUS RESULTANT HEAT INDEX VALUES ARE MORE UNCERTAIN DUE TO LACK OF WIDESPREAD SIGNIFICANT RAINFALL RECENTLY. CONDITIONS WILL STILL BE VERY WARM REGARDLESS SO WILL CONTINUE TO MENTION HEAT IN HWO. && .AVIATION /DISCUSSION FOR THE 211200Z TAFS/... ISSUED AT 615 AM EDT MON MAY 21 2012 MOSTLY VFR CONDITIONS THIS PERIOD...BUT MVFR POSSIBLE THROUGH THE FIRST SEVERAL HOURS OF THE TAF PERIOD. A COLD FRONT WILL SLOWLY WORK ACROSS THE SITES TODAY FROM WEST TO EAST. UNTIL IT PASSES...SCATTERED SHOWERS ARE POSSIBLE. PLACED VCSH AT KIND/KBMG WHERE BEST CHANCES FOR SHOWERS WILL BE. CURRENT LOCAL AND UPSTREAM OBSERVATIONS SHOW PATCHY MVFR CEILINGS AND VISIBILITIES IN FOG. DO NOT SEE WIDESPREAD CONDITIONS AT THE MOMENT...SO WILL NOT PUT MVFR AS PREDOMINANT IN THE FORECAST. HOWEVER POTENTIAL EXISTS FOR PERIODS OF CEILINGS AROUND 2000FT EARLY IN THE TAF PERIOD. CLOUDS WILL SCATTER OUT THIS AFTERNOON AS DRIER AIR WORKS IN. OVERNIGHT IT APPEARS SOME MOISTURE MAY RETURN TO THE EASTERN SITES...SO KEPT A SCATTERED LAYER AROUND 3000FT. WINDS WILL BECOME NORTH-NORTHWEST AND INCREASE INTO THE 10-15KT RANGE TODAY. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN/SMF SHORT TERM...RYAN LONG TERM....50 AVIATION...50
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
615 AM EDT MON MAY 21 2012 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 338 AM EDT MON MAY 21 2012 SCATTERED SHOWERS AND THUNDERSTORMS WILL GRADUALLY SHIFT EAST TODAY WITH A WEAK COLD FRONT...WITH DRY WEATHER RETURNING TONIGHT AS HIGH PRESSURE REESTABLISHES OVER THE REGION. AFTER A BRIEF COOLDOWN FOR TODAY AND TUESDAY...ARRIVAL OF RIDGING ALOFT AND SOUTHERLY FLOW WILL BRING A WARMING TREND BEGINNING ON WEDNESDAY. THE UPPER RIDGE WILL BECOME THE DOMINANT WEATHER FEATURE FOR THE OHIO VALLEY FOR LATE WEEK AND THE UPCOMING HOLIDAY WEEKEND...WITH DRY WEATHER AND THE HOTTEST TEMPERATURES OF THE YEAR SO FAR. && .NEAR TERM /TODAY/... ISSUED AT 338 AM EDT MON MAY 21 2012 WELL DEFINED OUTFLOW FROM EARLIER CONVECTION MOVING INTO WESTERN OHIO AS OF 07Z WITH WEAKENING SCATTERED CONVECTION LEFT IN ITS WAKE OVER THE FORECAST AREA. ACTUAL COLD FRONT STILL WEST OF THE REGION OVER CENTRAL ILLINOIS EARLY THIS MORNING. TEMPS WERE IN THE 60S AS OF 07Z. AS MENTIONED ABOVE...THE FRONTAL BOUNDARY APPEARS TO BE ALIGNED ROUGHLY FROM JUST EAST OF KORD SOUTHWEST TO NEAR KSTL. THE PASSAGE OF THE FRONT WILL USHER IN MUCH DRIER AIR AND A SHIFT TO NORTHWEST WINDS AS IT PROGRESSES EAST THROUGH THE FORECAST AREA DURING THE COURSE OF THE DAY. CONVECTIVE COVERAGE CONTINUES TO DIMINISH EARLY THIS MORNING AS INSTABILITY WANES AND FORCING ALOFT IS LIMITED. CURRENT RAP INDICATING THAT CONVECTIVE COVERAGE WILL DECREASE OVER THE NEXT FEW HOURS...WITH RENEWED DEVELOPMENT MAINLY ALONG AND AHEAD OF THE INSTABILITY GRADIENT AND FRONTAL BOUNDARY BY MID/LATE MORNING OVER THE EASTERN HALF OF THE FORECAST AREA. HAVE FOCUSED HIGHEST POPS SOUTH AND EAST OF THE INDY METRO WHERE COMBINATION OF THE INSTABILITY AND DEEPEST MOISTURE AXIS SHOULD PROMOTE LARGELY DISORGANIZED AND SCATTERED CONVECTION INTO THE AFTERNOON. WILL MAINTAIN LOW CHANCE POPS OVER WESTERN COUNTIES THIS MORNING TO ACCOUNT FOR ANY ISOLATED DEVELOPMENT ALONG THE FRONT AS IT MOVES INTO THE AREA. HOWEVER...EXPECT AN OVERALL DRYING TREND FOR THE AFTERNOON AS MODEL GUIDANCE IN AGREEMENT ON MUCH DRIER AIR ADVECTING INTO THE REGION FROM THE WEST WITH A CAPPING INVERSION BECOMING WELL ESTABLISHED BY LATE DAY. AXIS OF DEEPER MOISTURE WILL SHIFT EAST INTO OHIO BY EARLY EVENING WITH ANY LINGERING PRECIP DEPARTING THE FORECAST AREA. TEMPS...COOLER DAY SETTING UP AS COLD ADVECTION COMMENCES WITH THE FRONTAL PASSAGE. CONSALL AND MAVMOS GUIDANCE MATCHED UP WELL WITH LOW LEVEL THERMALS WITH MOST LOCATIONS REMAINING IN THE 70S THIS AFTERNOON. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... ISSUED AT 338 AM EDT MON MAY 21 2012 FORECAST CHALLENGES FOCUS ON TEMPS THROUGH THE PERIOD AS A WARMING TREND COMMENCES BY WEDNESDAY WITH THE RETURN OF RIDGING ALOFT. UPPER TROUGH WILL SHARPEN AS IT PASSES THE FORECAST AREA TONIGHT... EVENTUALLY DEVELOPING AN UPPER LOW THAT WILL DIVE INTO THE SOUTHEAST STATES BY TUESDAY NIGHT. THIS WILL CAUSE DEEPER MOISTURE TO HOLD OVER THE EASTERN OHIO VALLEY AND THE SOUTHERN APPALACHIANS INTO WEDNESDAY AS THE UPPER LOW SLOWLY PINWHEELS EAST INTO THE CAROLINAS. THE ONLY IMPACTS TO CENTRAL INDIANA WILL BE TO ACCENTUATE CLOUD COVER INTO TUESDAY OVER EASTERN COUNTIES WHERE PRESENCE OF A LOW LEVEL THERMAL TROUGH LIKELY TO ENABLE A HEALTHY CU FIELD ON THE BACK SIDE OF THE MOISTURE PLUME. FURTHER WEST ACROSS THE FORECAST AREA... INCREASINGLY DEEPER SUBSIDENCE WILL FUNNEL INTO THE REGION WITH MOSTLY SUNNY SKIES EXPECTED. RIDGING ALOFT WILL STEADILY EXPAND INTO THE REGION TUESDAY NIGHT AND WEDNESDAY AS THE UPPER LOW MOVES EAST ACROSS THE SOUTHERN APPALACHIANS. PROGRESSIVELY DEEPER SUBSIDENCE WILL EXPAND ACROSS THE OHIO VALLEY ON WEDNESDAY AS RETURN SOUTHERLY FLOW SIGNALS THE ARRIVAL OF WARM ADVECTION. RESULT WILL BE MAINLY CLEAR SKIES WEDNESDAY AND WEDNESDAY NIGHT AND THE BEGINNING OF A WARMUP THAT WILL CONTINUE THROUGH THE REST OF THE WEEK. TEMPS...MOS GUIDANCE AND CONSALL MATCHED UP WELL ON TUESDAY WITH TEMPERATURES MAINLY IN THE MID 70S. LEANED CLOSER TO WARMER MAVMOS WEDNESDAY AS HIGHS RETURN TO THE 80S. POTENTIAL FOR TEMPS TO SLIP INTO THE UPPER 40S BOTH TONIGHT AND TUESDAY NIGHT IN RURAL LOCALES WITH 50S ELSEWHERE. && .LONG TERM /THURSDAY THROUGH SUNDAY/... ISSUED AT 338 AM EDT MON MAY 21 2012 MODELS STILL DIFFER IN THE EXTENDED ON HOW FAR SOUTH A COLD FRONT GETS INTO THE AREA FRIDAY AND SATURDAY. GFS IS THE OUTLIER AGAIN IN BRINGING IN THE COLD FRONT FARTHER SOUTH. EVEN GFS ENSEMBLE MEAN KEEPS FRONT TO THE NORTH...AND EXPERIMENTAL GFS ENSEMBLE CONFIDENCE PLOTS SHOW LOW TO VERY LOW CONFIDENCE IN GFS TEMPERATURES BY NEXT WEEKEND. THUS WILL THROW OUT GFS AND GO CLOSER TO ECMWF AGAIN WITH THIS PACKAGE. THE ABOVE MEANS RAISING ALLBLEND TEMPERATURES NEXT WEEKEND AND REMOVING ANY CHANCES FOR RAIN THAT IT GIVES. ALSO ADJUSTED ALLBLEND DEWPOINTS AND SKY COVER AS NECESSARY. UPPER HIGH WILL MOVE INTO THE AREA LATE IN THE WEEK AND PERSIST INTO THE WEEKEND. THIS WILL RESULT IN HOT CONDITIONS FOR THE HOLIDAY WEEKEND WITH NO RAIN EXPECTED. DEWPOINTS AND THUS RESULTANT HEAT INDEX VALUES ARE MORE UNCERTAIN DUE TO LACK OF WIDESPREAD SIGNIFICANT RAINFALL RECENTLY. CONDITIONS WILL STILL BE VERY WARM REGARDLESS SO WILL CONTINUE TO MENTION HEAT IN HWO. && .AVIATION /DISCUSSION FOR THE 211200Z TAFS/... ISSUED AT 615 AM EDT MON MAY 21 2012 MOSTLY VFR CONDITIONS THIS PERIOD...BUT MVFR POSSIBLE THROUGH THE FIRST SEVERAL HOURS OF THE TAF PERIOD. A COLD FRONT WILL SLOWLY WORK ACROSS THE SITES TODAY FROM WEST TO EAST. UNTIL IT PASSES...SCATTERED SHOWERS ARE POSSIBLE. PLACED VCSH AT KIND/KBMG WHERE BEST CHANCES FOR SHOWERS WILL BE. CURRENT LOCAL AND UPSTREAM OBSERVATIONS SHOW PATCHY MVFR CEILINGS AND VISIBILITIES IN FOG. DO NOT SEE WIDESPREAD CONDITIONS AT THE MOMENT...SO WILL NOT PUT MVFR AS PREDOMINANT IN THE FORECAST. HOWEVER POTENTIAL EXISTS FOR PERIODS OF CEILINGS AROUND 2000FT EARLY IN THE TAF PERIOD. CLOUDS WILL SCATTER OUT THIS AFTERNOON AS DRIER AIR WORKS IN. OVERNIGHT IT APPEARS SOME MOISTURE MAY RETURN TO THE EASTERN SITES...SO KEPT A SCATTERED LAYER AROUND 3000FT. WINDS WILL BECOME NORTH-NORTHWEST AND INCREASE INTO THE 10-15KT RANGE TODAY. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM....50 AVIATION...50
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
422 AM EDT MON MAY 21 2012 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 338 AM EDT MON MAY 21 2012 SCATTERED SHOWERS AND THUNDERSTORMS WILL GRADUALLY SHIFT EAST TODAY WITH A WEAK COLD FRONT...WITH DRY WEATHER RETURNING TONIGHT AS HIGH PRESSURE REESTABLISHES OVER THE REGION. AFTER A BRIEF COOLDOWN FOR TODAY AND TUESDAY...ARRIVAL OF RIDGING ALOFT AND SOUTHERLY FLOW WILL BRING A WARMING TREND BEGINNING ON WEDNESDAY. THE UPPER RIDGE WILL BECOME THE DOMINANT WEATHER FEATURE FOR THE OHIO VALLEY FOR LATE WEEK AND THE UPCOMING HOLIDAY WEEKEND...WITH DRY WEATHER AND THE HOTTEST TEMPERATURES OF THE YEAR SO FAR. && .NEAR TERM /TODAY/... ISSUED AT 338 AM EDT MON MAY 21 2012 WELL DEFINED OUTFLOW FROM EARLIER CONVECTION MOVING INTO WESTERN OHIO AS OF 07Z WITH WEAKENING SCATTERED CONVECTION LEFT IN ITS WAKE OVER THE FORECAST AREA. ACTUAL COLD FRONT STILL WEST OF THE REGION OVER CENTRAL ILLINOIS EARLY THIS MORNING. TEMPS WERE IN THE 60S AS OF 07Z. AS MENTIONED ABOVE...THE FRONTAL BOUNDARY APPEARS TO BE ALIGNED ROUGHLY FROM JUST EAST OF KORD SOUTHWEST TO NEAR KSTL. THE PASSAGE OF THE FRONT WILL USHER IN MUCH DRIER AIR AND A SHIFT TO NORTHWEST WINDS AS IT PROGRESSES EAST THROUGH THE FORECAST AREA DURING THE COURSE OF THE DAY. CONVECTIVE COVERAGE CONTINUES TO DIMINISH EARLY THIS MORNING AS INSTABILITY WANES AND FORCING ALOFT IS LIMITED. CURRENT RAP INDICATING THAT CONVECTIVE COVERAGE WILL DECREASE OVER THE NEXT FEW HOURS...WITH RENEWED DEVELOPMENT MAINLY ALONG AND AHEAD OF THE INSTABILITY GRADIENT AND FRONTAL BOUNDARY BY MID/LATE MORNING OVER THE EASTERN HALF OF THE FORECAST AREA. HAVE FOCUSED HIGHEST POPS SOUTH AND EAST OF THE INDY METRO WHERE COMBINATION OF THE INSTABILITY AND DEEPEST MOISTURE AXIS SHOULD PROMOTE LARGELY DISORGANIZED AND SCATTERED CONVECTION INTO THE AFTERNOON. WILL MAINTAIN LOW CHANCE POPS OVER WESTERN COUNTIES THIS MORNING TO ACCOUNT FOR ANY ISOLATED DEVELOPMENT ALONG THE FRONT AS IT MOVES INTO THE AREA. HOWEVER...EXPECT AN OVERALL DRYING TREND FOR THE AFTERNOON AS MODEL GUIDANCE IN AGREEMENT ON MUCH DRIER AIR ADVECTING INTO THE REGION FROM THE WEST WITH A CAPPING INVERSION BECOMING WELL ESTABLISHED BY LATE DAY. AXIS OF DEEPER MOISTURE WILL SHIFT EAST INTO OHIO BY EARLY EVENING WITH ANY LINGERING PRECIP DEPARTING THE FORECAST AREA. TEMPS...COOLER DAY SETTING UP AS COLD ADVECTION COMMENCES WITH THE FRONTAL PASSAGE. CONSALL AND MAVMOS GUIDANCE MATCHED UP WELL WITH LOW LEVEL THERMALS WITH MOST LOCATIONS REMAINING IN THE 70S THIS AFTERNOON. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... ISSUED AT 338 AM EDT MON MAY 21 2012 FORECAST CHALLENGES FOCUS ON TEMPS THROUGH THE PERIOD AS A WARMING TREND COMMENCES BY WEDNESDAY WITH THE RETURN OF RIDGING ALOFT. UPPER TROUGH WILL SHARPEN AS IT PASSES THE FORECAST AREA TONIGHT... EVENTUALLY DEVELOPING AN UPPER LOW THAT WILL DIVE INTO THE SOUTHEAST STATES BY TUESDAY NIGHT. THIS WILL CAUSE DEEPER MOISTURE TO HOLD OVER THE EASTERN OHIO VALLEY AND THE SOUTHERN APPALACHIANS INTO WEDNESDAY AS THE UPPER LOW SLOWLY PINWHEELS EAST INTO THE CAROLINAS. THE ONLY IMPACTS TO CENTRAL INDIANA WILL BE TO ACCENTUATE CLOUD COVER INTO TUESDAY OVER EASTERN COUNTIES WHERE PRESENCE OF A LOW LEVEL THERMAL TROUGH LIKELY TO ENABLE A HEALTHY CU FIELD ON THE BACK SIDE OF THE MOISTURE PLUME. FURTHER WEST ACROSS THE FORECAST AREA... INCREASINGLY DEEPER SUBSIDENCE WILL FUNNEL INTO THE REGION WITH MOSTLY SUNNY SKIES EXPECTED. RIDGING ALOFT WILL STEADILY EXPAND INTO THE REGION TUESDAY NIGHT AND WEDNESDAY AS THE UPPER LOW MOVES EAST ACROSS THE SOUTHERN APPALACHIANS. PROGRESSIVELY DEEPER SUBSIDENCE WILL EXPAND ACROSS THE OHIO VALLEY ON WEDNESDAY AS RETURN SOUTHERLY FLOW SIGNALS THE ARRIVAL OF WARM ADVECTION. RESULT WILL BE MAINLY CLEAR SKIES WEDNESDAY AND WEDNESDAY NIGHT AND THE BEGINNING OF A WARMUP THAT WILL CONTINUE THROUGH THE REST OF THE WEEK. TEMPS...MOS GUIDANCE AND CONSALL MATCHED UP WELL ON TUESDAY WITH TEMPERATURES MAINLY IN THE MID 70S. LEANED CLOSER TO WARMER MAVMOS WEDNESDAY AS HIGHS RETURN TO THE 80S. POTENTIAL FOR TEMPS TO SLIP INTO THE UPPER 40S BOTH TONIGHT AND TUESDAY NIGHT IN RURAL LOCALES WITH 50S ELSEWHERE. && .LONG TERM /THURSDAY THROUGH SUNDAY/... ISSUED AT 338 AM EDT MON MAY 21 2012 MODELS STILL DIFFER IN THE EXTENDED ON HOW FAR SOUTH A COLD FRONT GETS INTO THE AREA FRIDAY AND SATURDAY. GFS IS THE OUTLIER AGAIN IN BRINGING IN THE COLD FRONT FARTHER SOUTH. EVEN GFS ENSEMBLE MEAN KEEPS FRONT TO THE NORTH...AND EXPERIMENTAL GFS ENSEMBLE CONFIDENCE PLOTS SHOW LOW TO VERY LOW CONFIDENCE IN GFS TEMPERATURES BY NEXT WEEKEND. THUS WILL THROW OUT GFS AND GO CLOSER TO ECMWF AGAIN WITH THIS PACKAGE. THE ABOVE MEANS RAISING ALLBLEND TEMPERATURES NEXT WEEKEND AND REMOVING ANY CHANCES FOR RAIN THAT IT GIVES. ALSO ADJUSTED ALLBLEND DEWPOINTS AND SKY COVER AS NECESSARY. UPPER HIGH WILL MOVE INTO THE AREA LATE IN THE WEEK AND PERSIST INTO THE WEEKEND. THIS WILL RESULT IN HOT CONDITIONS FOR THE HOLIDAY WEEKEND WITH NO RAIN EXPECTED. DEWPOINTS AND THUS RESULTANT HEAT INDEX VALUES ARE MORE UNCERTAIN DUE TO LACK OF WIDESPREAD SIGNIFICANT RAINFALL RECENTLY. CONDITIONS WILL STILL BE VERY WARM REGARDLESS SO WILL CONTINUE TO MENTION HEAT IN HWO. && .AVIATION /DISCUSSION FOR THE 210830Z TAF UPDATE/... ISSUED AT 422 AM EDT MON MAY 21 2012 TS HAS ENDED ACROSS THE AREA SO REMOVED MENTION IN THE TAF. THERE WILL STILL BE SCATTERED LIGHT SHOWERS...BUT STILL EXPECT VFR CONDITIONS IN THEM. WINDS HAVE BECOME LIGHT AND VARIABLE AHEAD OF THE COLD FRONT...BUT THEY WILL STILL BECOME NORTHWEST LATER THIS MORNING AS THE FRONT MOVES THROUGH. RELEVANT PORTION OF PREVIOUS DISCUSSION FOLLOWS... LOWER END VFR CEILINGS SHOULD DEVELOP AT ALL SITES OVERNIGHT AND THEN PERSIST INTO THE DAY MONDAY AS COLD FRONT PASSES. DRIER AIR WILL THEN SCATTER OUT THE CLOUDS DURING THE AFTERNOON. WIND DIRECTION WILL GENERALLY BE OUT OF THE NORTHWEST. THERE COULD BE SOME VARIATION EARLY IN THE PERIOD UNTIL ACTUAL COLD FRONT PASSES. WIND SPEEDS WILL REMAIN AT 10 TO 15KT THROUGH THE DAY MONDAY...DIMINISHING SOME AFTER SUNSET. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM....50 AVIATION...TDUD/50
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
338 AM EDT MON MAY 21 2012 .UPDATE... THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 338 AM EDT MON MAY 21 2012 SCATTERED SHOWERS AND THUNDERSTORMS WILL GRADUALLY SHIFT EAST TODAY WITH A WEAK COLD FRONT...WITH DRY WEATHER RETURNING TONIGHT AS HIGH PRESSURE REESTABLISHES OVER THE REGION. AFTER A BRIEF COOLDOWN FOR TODAY AND TUESDAY...ARRIVAL OF RIDGING ALOFT AND SOUTHERLY FLOW WILL BRING A WARMING TREND BEGINNING ON WEDNESDAY. THE UPPER RIDGE WILL BECOME THE DOMINANT WEATHER FEATURE FOR THE OHIO VALLEY FOR LATE WEEK AND THE UPCOMING HOLIDAY WEEKEND...WITH DRY WEATHER AND THE HOTTEST TEMPERATURES OF THE YEAR SO FAR. && .NEAR TERM /TODAY/... ISSUED AT 338 AM EDT MON MAY 21 2012 WELL DEFINED OUTFLOW FROM EARLIER CONVECTION MOVING INTO WESTERN OHIO AS OF 07Z WITH WEAKENING SCATTERED CONVECTION LEFT IN ITS WAKE OVER THE FORECAST AREA. ACTUAL COLD FRONT STILL WEST OF THE REGION OVER CENTRAL ILLINOIS EARLY THIS MORNING. TEMPS WERE IN THE 60S AS OF 07Z. AS MENTIONED ABOVE...THE FRONTAL BOUNDARY APPEARS TO BE ALIGNED ROUGHLY FROM JUST EAST OF KORD SOUTHWEST TO NEAR KSTL. THE PASSAGE OF THE FRONT WILL USHER IN MUCH DRIER AIR AND A SHIFT TO NORTHWEST WINDS AS IT PROGRESSES EAST THROUGH THE FORECAST AREA DURING THE COURSE OF THE DAY. CONVECTIVE COVERAGE CONTINUES TO DIMINISH EARLY THIS MORNING AS INSTABILITY WANES AND FORCING ALOFT IS LIMITED. CURRENT RAP INDICATING THAT CONVECTIVE COVERAGE WILL DECREASE OVER THE NEXT FEW HOURS...WITH RENEWED DEVELOPMENT MAINLY ALONG AND AHEAD OF THE INSTABILITY GRADIENT AND FRONTAL BOUNDARY BY MID/LATE MORNING OVER THE EASTERN HALF OF THE FORECAST AREA. HAVE FOCUSED HIGHEST POPS SOUTH AND EAST OF THE INDY METRO WHERE COMBINATION OF THE INSTABILITY AND DEEPEST MOISTURE AXIS SHOULD PROMOTE LARGELY DISORGANIZED AND SCATTERED CONVECTION INTO THE AFTERNOON. WILL MAINTAIN LOW CHANCE POPS OVER WESTERN COUNTIES THIS MORNING TO ACCOUNT FOR ANY ISOLATED DEVELOPMENT ALONG THE FRONT AS IT MOVES INTO THE AREA. HOWEVER...EXPECT AN OVERALL DRYING TREND FOR THE AFTERNOON AS MODEL GUIDANCE IN AGREEMENT ON MUCH DRIER AIR ADVECTING INTO THE REGION FROM THE WEST WITH A CAPPING INVERSION BECOMING WELL ESTABLISHED BY LATE DAY. AXIS OF DEEPER MOISTURE WILL SHIFT EAST INTO OHIO BY EARLY EVENING WITH ANY LINGERING PRECIP DEPARTING THE FORECAST AREA. TEMPS...COOLER DAY SETTING UP AS COLD ADVECTION COMMENCES WITH THE FRONTAL PASSAGE. CONSALL AND MAVMOS GUIDANCE MATCHED UP WELL WITH LOW LEVEL THERMALS WITH MOST LOCATIONS REMAINING IN THE 70S THIS AFTERNOON. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... ISSUED AT 338 AM EDT MON MAY 21 2012 FORECAST CHALLENGES FOCUS ON TEMPS THROUGH THE PERIOD AS A WARMING TREND COMMENCES BY WEDNESDAY WITH THE RETURN OF RIDGING ALOFT. UPPER TROUGH WILL SHARPEN AS IT PASSES THE FORECAST AREA TONIGHT... EVENTUALLY DEVELOPING AN UPPER LOW THAT WILL DIVE INTO THE SOUTHEAST STATES BY TUESDAY NIGHT. THIS WILL CAUSE DEEPER MOISTURE TO HOLD OVER THE EASTERN OHIO VALLEY AND THE SOUTHERN APPALACHIANS INTO WEDNESDAY AS THE UPPER LOW SLOWLY PINWHEELS EAST INTO THE CAROLINAS. THE ONLY IMPACTS TO CENTRAL INDIANA WILL BE TO ACCENTUATE CLOUD COVER INTO TUESDAY OVER EASTERN COUNTIES WHERE PRESENCE OF A LOW LEVEL THERMAL TROUGH LIKELY TO ENABLE A HEALTHY CU FIELD ON THE BACK SIDE OF THE MOISTURE PLUME. FURTHER WEST ACROSS THE FORECAST AREA... INCREASINGLY DEEPER SUBSIDENCE WILL FUNNEL INTO THE REGION WITH MOSTLY SUNNY SKIES EXPECTED. RIDGING ALOFT WILL STEADILY EXPAND INTO THE REGION TUESDAY NIGHT AND WEDNESDAY AS THE UPPER LOW MOVES EAST ACROSS THE SOUTHERN APPALACHIANS. PROGRESSIVELY DEEPER SUBSIDENCE WILL EXPAND ACROSS THE OHIO VALLEY ON WEDNESDAY AS RETURN SOUTHERLY FLOW SIGNALS THE ARRIVAL OF WARM ADVECTION. RESULT WILL BE MAINLY CLEAR SKIES WEDNESDAY AND WEDNESDAY NIGHT AND THE BEGINNING OF A WARMUP THAT WILL CONTINUE THROUGH THE REST OF THE WEEK. TEMPS...MOS GUIDANCE AND CONSALL MATCHED UP WELL ON TUESDAY WITH TEMPERATURES MAINLY IN THE MID 70S. LEANED CLOSER TO WARMER MAVMOS WEDNESDAY AS HIGHS RETURN TO THE 80S. POTENTIAL FOR TEMPS TO SLIP INTO THE UPPER 40S BOTH TONIGHT AND TUESDAY NIGHT IN RURAL LOCALES WITH 50S ELSEWHERE. && .LONG TERM /THURSDAY THROUGH SUNDAY/... ISSUED AT 338 AM EDT MON MAY 21 2012 MODELS STILL DIFFER IN THE EXTENDED ON HOW FAR SOUTH A COLD FRONT GETS INTO THE AREA FRIDAY AND SATURDAY. GFS IS THE OUTLIER AGAIN IN BRINGING IN THE COLD FRONT FARTHER SOUTH. EVEN GFS ENSEMBLE MEAN KEEPS FRONT TO THE NORTH...AND EXPERIMENTAL GFS ENSEMBLE CONFIDENCE PLOTS SHOW LOW TO VERY LOW CONFIDENCE IN GFS TEMPERATURES BY NEXT WEEKEND. THUS WILL THROW OUT GFS AND GO CLOSER TO ECMWF AGAIN WITH THIS PACKAGE. THE ABOVE MEANS RAISING ALLBLEND TEMPERATURES NEXT WEEKEND AND REMOVING ANY CHANCES FOR RAIN THAT IT GIVES. ALSO ADJUSTED ALLBLEND DEWPOINTS AND SKY COVER AS NECESSARY. UPPER HIGH WILL MOVE INTO THE AREA LATE IN THE WEEK AND PERSIST INTO THE WEEKEND. THIS WILL RESULT IN HOT CONDITIONS FOR THE HOLIDAY WEEKEND WITH NO RAIN EXPECTED. DEWPOINTS AND THUS RESULTANT HEAT INDEX VALUES ARE MORE UNCERTAIN DUE TO LACK OF WIDESPREAD SIGNIFICANT RAINFALL RECENTLY. CONDITIONS WILL STILL BE VERY WARM REGARDLESS SO WILL CONTINUE TO MENTION HEAT IN HWO. && .AVIATION /DISCUSSION FOR THE 210600Z TAFS/... ISSUED AT 105 AM EDT MON MAY 21 2012 CONVECTION SHOULD IMPACT KIND AND KBMG EARLY IN THE PERIOD BEFORE IT DIMINISHES OVERNIGHT. LOOKS LIKE MVFR CONDITIONS IN TSRA HERE WITH VFR OUTSIDE OF TSRA. CANNOT RULE OUT BRIEF PERIOD OF IFR IF A HEAVIER CELL HITS AN AIRPORT. AT KLAF/KHUF ONLY SCATTERED SHOWERS LOOK TO BE AROUND EARLY IN THE PERIOD. LOWER END VFR CEILINGS SHOULD THEN DEVELOP AT ALL SITES OVERNIGHT AND THEN PERSIST INTO THE DAY MONDAY AS COLD FRONT PASSES. DRIER AIR WILL THEN SCATTER OUT THE CLOUDS DURING THE AFTERNOON. WIND DIRECTION WILL GENERALLY BE OUT OF THE NORTHWEST. THERE COULD BE SOME VARIATION EARLY IN THE PERIOD UNTIL ACTUAL COLD FRONT PASSES. WIND SPEEDS WILL REMAIN AT 10 TO 15KT THROUGH THE DAY MONDAY...DIMINISHING SOME AFTER SUNSET. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM....50 AVIATION...TDUD/50
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
703 PM CDT TUE MAY 22 2012 ...UPDATED AVIATION SECTION FOR 00Z TAFS... .SYNOPSIS... ISSUED AT 1218 PM CDT TUE MAY 22 2012 A 500MB UPPER TROUGH WAS LOCATED NEAR THE SOUTHWEST COAST OF BRITISH COLUMBIA AND NORTHWEST WASHINGTON AT 12Z TUESDAY. A 120-140KT UPPER LEVEL JET WAS PLACE NEAR AND JUST SOUTHWEST OF THE BASE OF THIS UPPER TROUGH. 90-110 METER HEIGHT FALLS WERE OBSERVED ACROSS EASTERN IDAHO AND WESTERN MONTANA. A WESTERLY FLOW EXTENDED ACROSS THE ROCKIES INTO THE WESTERN HIGH PLAINS WITH +12 TO +13C 700MB TEMPERATURES STRETCHING FROM EASTERN WYOMING/WESTERN NEBRASKA INTO NORTHEAST NEW MEXICO. UNDER THESE WARM 700MB TEMPERATURES AT THE SURFACE THERE WAS A TROUGH OF LOW PRESSURE ACROSS WESTERN NEBRASKA AND EXTREME EASTERN COLORADO/FAR WESTERN KANSAS. && .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 128 PM CDT TUE MAY 22 2012 RAP, NAM AND HRRR PLACE THE SURFACE TROUGH OF LOW PRESSURE NEAR THE COLORADO BORDER THIS EVENING. MODEL SOUNDINGS AT 00Z WEDNESDAYS IN THIS AREA INDICATING LITTLE TO NO CIN WITH A TEMPERATURES DRY ADIABATIC UP TO AROUND THE 600MB LEVEL WHERE SOME MOISTURE IS PRESENT. ALSO OBSERVING SOME INSTABILITY PRESENT AS WELL SO AM UNABLE TO COMPLETELY RULE OUT A EARLY EVENING THUNDERSTORM DEVELOPING NEAR THE COLORADO BORDER EARLY THIS EVENING. RAP AND HRRR DO HINT AT A FEW STORMS DEVELOPING AFTER 22Z NEAR THE ELKHART WHERE THE BETTER INSTABILITY ARE FORECAST TO BE LOCATED. WITH THIS IN MIND THE PREVIOUS PRECIPITATION FORECAST FOR EXTREME SOUTHWEST KANSAS STILL APPEARS TO BE ON TRACK. ALSO BASED ON THE INVERTED V TYPE OF SOUNDINGS IT DOES APPEAR THAT STRONG WINDS UP TO 60 OR 70 MPH WILL BE THE MAIN HAZARD. ANY STORM THAT DOES DEVELOP EARLY THIS EVENING IS EXPECTED TO END BEFORE MIDNIGHT BUT MAY MOVE AS FAR EAST AS LIBERAL IF THESE A COLD POOL CAN BE DEVELOPED FROM STORMS. AFTER MIDNIGHT SOUTH WINDS OF 15 TO 25 MPH ARE EXPECTED TO CONTINUE AND BASED ON TEMPERATURES EARLIER THIS MORNING WILL FAVOR OVERNIGHT LOWS AROUND 5F WARMER THAN GUIDANCE. ON WEDNESDAY A SURFACE TROUGH/DRYLINE WILL SLIDE EAST INTO WESTERN KANSAS DURING THE DAY AS A COLD FRONT DROPS SOUTH INTO NORTHWEST KANSAS BY LATE MORNING. THE COLD FRONT IS EXPECTED TO BE LOCATED FROM WEST CENTRAL KANSAS AND NORTH CENTRAL KANSAS BY THE MID AFTERNOON AS WARM MID LEVEL TEMPERATURES SPREADS EAST ACROSS SOUTHWEST KANSAS. MODEL SOUNDINGS INDICATING ANOTHER DAY OF GOOD MIXING AND BASED ON MODEL SOUNDINGS AT 00Z THURSDAY IT CURRENTLY APPEARS HIGHS AROUND 100 DEGREES WILL STILL BE POSSIBLE WEST OF THE DRYLINE. EAST OF THE DRYLINE AND NEAR THE COLD FRONT THE HIGHS WILL BE SLIGHTLY COOLER AND RANGE FROM THE LOW TO MID 90S. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 234 PM CDT TUE MAY 22 2012 WEDNESDAY NIGHT: A FRONTAL BOUNDARY COULD BE THE IMPETUS FOR CONVECTION WEDNESDAY NIGHT MAINLY ACROSS THE INTERSTATE 70 CORRIDOR. MARGINAL SURFACE DEWPOINTS IN THE 50S DEG F AND VERY WARM MAXIMUM TEMPERATURES IN THE 90S DEG F ACROSS CENTRAL KANSAS WILL CONTRIBUTE TO 1500 TO 2500 J/KG OF SBCAPE. AN 850 HPA THETA-E AXIS WILL ALSO EXIST ACROSS WEST CENTRAL KANSAS WITH BROAD SOUTHWESTERLY FLOW ALOFT WHICH POINT TO FAVORABLE CONDITIONS FOR CONVECTION. SEVERE WEATHER CANNOT BE RULED OUT WITH 40 TO 50 KT OF BULK 0 TO 6 KM SHEAR. THURSDAY: A BROAD 500 HPA TROUGH IS EXPECTED FROM THE PACIFIC NORTHWEST TOWARDS THE NORTHERN PLAINS. ANOTHER VORTMAX MOVING DOWNSTREAM WILL USHER IN A COLD FRONT EXTENDING FROM THE UPPER MIDWEST TO SOMEWHERE IN KANSAS. I SAY SOMEWHERE BECAUSE THERE IS PRETTY LARGE SPATIAL DIFFERENCES BETWEEN THE ECMWF/GFS. THIS IS PARTICULARLY TRUE WHEN THE FRONT RETURNS AS A WARM FRONT LATE THURSDAY. DECIDED TO TAKE THE MORE AGGRESSIVE ECMWF APPROACH WITH THE NORTHWARD PROGRESSION OF THIS WARM FRONT. SOUTH OF THIS FRONT, LOW LEVEL TEMPS ARE EXPECTED TO BE VERY WARM (30 DEG C @ 850 HPA/15 DEG C @ 700 HPA), SO HAVE KEPT LOWER 90S DEG F TOWARDS THE OKLAHOMA BORDER AND "COOLER" 80S DEG F ACROSS WEST CENTRAL KANSAS. NOT EXPECTING ANY CONVECTION AS A RESULT OF THE EML ADVECTION ACROSS SW KANSAS. FRIDAY: A WAA PATTERN WILL STRENGTHEN FRIDAY WITH THE EML SPREADING FURTHER NORTH AND 850 HPA TEMPERATURES WARMING TO 33 DEC C. 700 HPA TEMPERATURES WILL ALSO BE VERY WARM AND NEAR 16 DEG C. THERE MIGHT BE AN ISOLATED STORM NEAR HAYS FRIDAY EVENING, BUT AM DUBIOUS OF THIS GFS SOLUTION SO HAVE KEPT POPS IN SLIGHT CATEGORY GIVEN THE STOUT EML. THERE IS ALSO NOT MUCH IN THE WAY OF UPPER LEVEL SUPPORT AS 500 HPA HEIGHT INCREASES ARE EXPECTED ACROSS THE REGION ASSOCIATED WITH MID LEVEL SHORTWAVE RIDGING. TEMPERATURES WILL BE HOT AND IN THE 90S DEG F. IF THE ECMWF SOLUTION IS CORRECT, THEN A 100 DEGREE DAY IS POSSIBLE FOR SOME LOCATIONS AND TEMPERATURES NEED TO BE INCREASED IN THE FUTURE. SATURDAY AND BEYOND: FOLLOWED THE ECMWF SOLUTION FOR THIS PERIOD. A VERY BROAD MID LEVEL TROUGH IS EXPECTED ACROSS THE GREAT BASIN. ANY JET LEVEL DYNAMICS LOOK TO REMAIN WELL NORTH OF KANSAS WITH GREATEST CHANCE OF HIGHER IMPACT SEVERE WEATHER NORTH OF THE REGION. THERE COULD BE SOME STORMS ACROSS SOUTHWEST KANSAS THROUGH THE WEEKEND, HOWEVER, THE ATMOSPHERE LOOKS PRETTY CAPPED. MADE A FEW TWEAKS TO THE ALLBLEND POPS (CLEANED UP) AND WARMED TEMPERATURES UP WITH A BIAS TOWARDS THE ECMWF. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 702 PM CDT TUE MAY 22 2012 SOUTH WINDS OF 17 TO 20 KNOTS WILL CONTINUE THROUGH MUCH OF THE NIGHT TONIGHT AS A STRONG SURFACE LOW REMAINS OVER FAR WESTERN KANSAS NEAR THE COLORADO BORDER. A VERY STRONG LOW LEVEL JET ABOUT 1500 TO 2000 FEET OFF THE SURFACE WILL ALSO EXIST BETWEEN 03-06Z WITH PEAK WINDS IN THE LOW LEVEL JET AROUND 60 KNOTS. WILL MAINTAIN THE LLWS IN THE TAFS 03-11Z OR SO AT ALL TERMINALS (DDC, GCK, HYS). VFR CEILING WILL PREVAIL THROUGH TONIGHT AND WEDNESDAY. && .PRELIMINARY POINT TEMPS/POPS... DDC 65 97 63 86 / 0 10 10 10 GCK 64 98 58 85 / 0 10 10 10 EHA 63 99 58 91 / 10 0 10 10 LBL 65 102 61 89 / 10 0 10 10 HYS 67 93 61 83 / 0 20 20 10 P28 66 93 70 89 / 0 0 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BURGERT SHORT TERM...BURGERT LONG TERM...SUGDEN AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS GOODLAND KS
237 PM MDT MON MAY 21 2012 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 121 PM MDT MON MAY 21 2012 16Z WATER VAPOR IMAGERY/RUC ANALYSIS INDICATED BROAD RIDGING IN PLACE ACROSS THE CENTRAL ROCKIES AND ADJACENT HIGH PLAINS...WITH TROUGH APPROACHING THE PACIFIC NORTHWEST. AT THE SFC...TROUGH WAS IN PLACE ACROSS CENTRAL AND EASTERN COLORADO ...ROUGHLY BETWEEN KDNR AND KAKO. TO THE EAST OF THIS TROUGH...MOISTURE ADVECTION WAS INCREASING WITH AN AREA OF DEWPOINTS AT OR ABOVE 50 F FROM KLIC SOUTHEAST INTO THE OKLAHOMA PANHANDLE. 12Z RAOBS AT DNR AND DDC INDICATED AREA OF STEEP MID LEVEL LAPSE RATES BETWEEN H7 AND H6...WITH A MUCH DEEPER LAYER NOTED AT DNR. MAIN CONCERN FOR THE SHORT TERM PERIODS WILL BE CONVECTIVE INITIATION CHANCES TODAY AND TEMPS/RH/FIRE WX TOMORROW. REST OF THE AFTERNOON-TONIGHT...WITH AFOREMENTIONED MOISTURE ADVECTION ALREADY ONGOING PER SFC OBS...AND NOSE OF STEEP MID LEVEL LAPSE RATES IN PLACE ALONG SFC TROUGH ACROSS EASTERN COLORADO CONFIDENCE INCREASING IN CONVECTIVE INITIATION ALONG SFC TROUGH THIS AFTERNOON...ESPECIALLY GIVEN THAT MIXED LAYER TDS ARE VERY SIMILAR TO FORECAST SFC VALUES INDICATING SOME DEPTH TO THE MOISTURE PROFILE. WHILE CONFIDENCE IN DEVELOPMENT OF THUNDERSTORMS IS HIGHER...HIGHER RES MODELS KEEPING COVERAGE FAIRLY SPARSE AND WITH LATEST HRRR JUMPING AROUND QUITE A BIT WITH TIMING AND LOCATION...DO NOT THINK POPS ABOVE THE 20-30 PERCENT RANGE WARRANTED JUST YET. WITH A LOT OF UNCERTAINTY IN THE DETAILS...HAVE GENERALLY WENT WITH BROADER COVERAGE OF POPS STARTING FIRST AROUND SFC TROUGH AROUND 20Z AND GRADUALLY SHIFTING EAST AND DIMINISHING. SOME ELEVATED INSTABILITY REMAINS THROUGH THE NIGHT WITH SOME WEAK ASCENT EXPECTED TO THE WEST OF H7 THERMAL RIDGE. PROBABILISTIC GUIDANCE NOT REALLY SUPPORTING MUCH OF A PRECIP THREAT AT THIS POINT...BUT CANNOT TOTALLY RULE OUT SOME ELEVATED OVERNIGHT STORMS AND WILL GENERALLY KEEP PREVIOUS FORECAST IN THIS REGARD. GIVEN ALREADY OBSERVED MOISTURE TRANSPORT...DO HAVE SOME CONCERNS ABOUT THE DEVELOPMENT OF FOG OVERNIGHT. WINDS SHOULD GENERALLY STAY UP WHICH WILL MINIMIZE THE THREAT SOME WHAT...BUT GIVEN EXPECTED MOISTURE PROFILE AND SREF INDICATING A SMALL THREAT FOR FOG THINK AT LEAST A PATCHY MENTION IS IN ORDER. TUESDAY...H5 RIDGE AXIS WILL SHIFT TO THE EAST THROUGH THE DAY...WITH CWA UNDER THE INFLUENCE OF LARGE SCALE FORCING FOR SUBSIDENCE THROUGH MUCH OF THE DAY. WHILE SYNOPTIC SCALE SUPPORT IS LACKING...FAIRLY STRONG AND PERSISTENT CONVERGENCE EXPECTED ALONG DRYLINE THAT WILL DEVELOP ACROSS AREA DURING THE AFTERNOON. COULD POTENTIALLY SEE A STORM OR TWO DEVELOP IN THIS AREA...BUT GIVEN LARGE SCALE PATTERN...POTENTIAL FOR A STRONG CAP AND VERY LOW PROBABILITIES FROM THE NORMALLY WET SREF DATABASE...CONFIDENCE NOT HIGH ENOUGH TO INCLUDE THUNDERSTORM THREAT AT THIS TIME. MIXED LAYER TEMPS STILL SUPPORT TEMPS IN THE 90S ACROSS MUCH OF THE AREA...ALTHOUGH THERE DOES APPEAR TO BE SOME DISCREPANCIES FOR HOW WARM THINGS WILL GET WITH SREF INDICATING A RANGE BETWEEN 97 AND AROUND 88 FOR GLD. GIVEN OVERALL PATTERN AND POTENTIAL TO BE ON MUCH DRIER SIDE OF THE DRYLINE THINK WARMER SOLUTIONS THE WAY TO AND MADE ONLY MINOR CHANGES TO GOING FORECAST. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 236 PM MDT MON MAY 21 2012 A COLD FRONT WILL DROP SOUTH TOWARDS OUR CWA TUESDAY NIGHT AS A SHORTWAVE TROUGH MOVES ACROSS THE NORTHERN PLAINS. WITH AIRMASS OVER CWA GENERALLY STABILIZING TUESDAY EVENING THUNDERSTORM CHANCES REMAIN MINIMAL AND WILL BE TIED MAINLY TO WHAT DEVELOPS DURING THE AFTERNOON. MODEL DIFFERENCES IN THE TIMING/POSITION OF THE FRONT WILL HAVE A LARGER IMPACT ON THE TEMPERATURE FORECAST WEDNESDAY WHEN IT WILL STALL OVER THE CWA AND THEN LIFT NORTH AS A WARM FRONT. ECMWF AND GFS TEND TO BE THE QUICKEST IN DEVELOPING A STRONG LEE TROUGH OVER EASTERN COLORADO...PUSHING THE FRONT NORTH BY MIDDAY. CURRENT HIGH TEMP FORECAST FOR WEDNESDAY REFLECTS A BLEND OF SOLUTIONS WITH UPPER 90S OVER SW PART OF THE CWA...AND UPPER 70S IN THE NORTHWEST. WERE THE FRONT TO LIFT QUICKER...MID-UPPER 90S COULD BE EXPECTED ACROSS A MUCH LARGER PART OF THE CWA. WITH THE SURFACE TROUGH EXPECTED TO BE OVER THE CWA BY MIDDAY...STRONGEST SURFACE GRADIENT SHOULD REMAIN EAST...SO WINDS SHOULD REMAIN BELOW RED FLAG CRITERIA. LARGE SCALE TROUGH DEVELOPS OVER THE GREAT BASIN/NORTHERN ROCKIES BY WEDNESDAY AFTERNOON...WITH A SERIES OF WEAK SHORTWAVE TROUGH MOVING JUST NORTH AND WEST OF THE CWA THROUGH NEXT WEEKEND. THE FIRST SHORTWAVE ARRIVES BY WEDNESDAY NIGHT...WITH THUNDERSTORMS POSSIBLY INITIATING OVER NORTHEAST COLORADO. BEST CHANCES WILL BE ACROSS THE NORTH AFTER MIDNIGHT WEDNESDAY NIGHT WHEN A COLD FRONT WILL MOVE INTO SOUTHWEST NEBRASKA AND STALL. I HAVE LESS CONFIDENCE FURTHER SOUTH AND EAST...HOWEVER WITH AT LEAST SOME GUIDANCE SHOWING DEVELOPMENT TOWARDS THE I-70 CORRIDOR...I FELT COMFORTABLE KEEPING SLIGHT CHANCE/CHANCE POPS IN PLACE. BY THURSDAY THIS INITIAL SHORTWAVE WILL MOVE TO THE EAST WITH SUBSIDENCE BUILDING IN OVER THE CWA IN IT WAKE. AT THE SAME TIME ANOTHER WEAK DISTURBANCE WILL BE MOVING IN FROM THE WEST BY THURSDAY AFTERNOON/NIGHT...WITH POPS INCREASING ONCE AGAIN FROM THE WEST...AND CHANCES LIMITED TO NORTH OF INTERSTATE 70. FRIDAY-MONDAY...LARGE SCALE TROUGH REMAINS IN PLACE ACROSS THE WESTERN CONUS...EVENTUALLY BREAKING DOWN AND TRANSITIONING TO A WESTERLY ZONAL PATTERN BY EARLY NEXT WEEK. RESULT WILL BE A FAIRLY ACTIVE PATTERN...WITH STORM TRACK FAVORING NORTHERN PORTIONS OF OUR CWA FOR SHOWER/THUNDERSTORM CHANCES. CONFIDENCE WAS TOO LOW TO RAISE POPS BEYOND 20/30 RANGE...CONSIDERING DIFFERENCE IN TIMING OF THESE FEATURES...AND DIFFERENCES IN POSITION OF SURFACE FEATURES AS HANDLED BY GUIDANCE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1132 AM MDT MON MAY 21 2012 VFR CONDITIONS EXPECTED FOR THE NEXT 24 HOURS AT BOTH LOCATIONS AS DEVELOPING SFC TROUGH WILL KEEP WINDS OUT OF THE SOUTH IN THE 15 TO 20 KT RANGE THROUGH THE BULK OF THE PERIOD ALTHOUGH WINDS SHOULD DIE DOWN A BIT IN THE OVERNIGHT HOURS. POTENTIAL FOR ISOLATED THUNDERSTORMS BTWN 22 AND 2Z MAINLY AT GLD AS STORMS FORM ALONG SFC TROUGH AND DRIFT EAST...BUT PROBABILITIES TOO LOW TO INCLUDE IN TAFS ATTM. && .FIRE WEATHER... ISSUED AT 121 PM MDT MON MAY 21 2012 VERY WARM AND DRY WEATHER IS EXPECTED ACROSS MUCH OF THE AREA ON TUESDAY...WITH AFTERNOON HUMIDITIES BELOW 15 PERCENT EXPECTED ALONG AND EAST OF THE COLORADO AND KANSAS STATE LINE. WESTERLY WINDS WILL GRADUALLY INCREASE IN THIS AREA TO AROUND 15 MPH IN THE AFTERNOON. WITH RECENT RAINFALL AND WINDS NOT EXPECTED TO INCREASE TO LATE IN THE AFTERNOON...OVERALL CONFIDENCE IN CRITICAL FIRE WEATHER CONDITIONS IS TOO LOW TO WARRANT A WATCH OR WARNING AT THIS POINT. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...JRM LONG TERM...DR AVIATION...JRM FIRE WEATHER...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
125 PM MDT MON MAY 21 2012 .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 121 PM MDT MON MAY 21 2012 16Z WATER VAPOR IMAGERY/RUC ANALYSIS INDICATED BROAD RIDGING IN PLACE ACROSS THE CENTRAL ROCKIES AND ADJACENT HIGH PLAINS...WITH TROUGH APPROACHING THE PACIFIC NORTHWEST. AT THE SFC...TROUGH WAS IN PLACE ACROSS CENTRAL AND EASTERN COLORADO ...ROUGHLY BETWEEN KDNR AND KAKO. TO THE EAST OF THIS TROUGH...MOISTURE ADVECTION WAS INCREASING WITH AN AREA OF DEWPOINTS AT OR ABOVE 50 F FROM KLIC SOUTHEAST INTO THE OKLAHOMA PANHANDLE. 12Z RAOBS AT DNR AND DDC INDICATED AREA OF STEEP MID LEVEL LAPSE RATES BETWEEN H7 AND H6...WITH A MUCH DEEPER LAYER NOTED AT DNR. MAIN CONCERN FOR THE SHORT TERM PERIODS WILL BE CONVECTIVE INITIATION CHANCES TODAY AND TEMPS/RH/FIRE WX TOMORROW. REST OF THE AFTERNOON-TONIGHT...WITH AFOREMENTIONED MOISTURE ADVECTION ALREADY ONGOING PER SFC OBS...AND NOSE OF STEEP MID LEVEL LAPSE RATES IN PLACE ALONG SFC TROUGH ACROSS EASTERN COLORADO CONFIDENCE INCREASING IN CONVECTIVE INITIATION ALONG SFC TROUGH THIS AFTERNOON...ESPECIALLY GIVEN THAT MIXED LAYER TDS ARE VERY SIMILAR TO FORECAST SFC VALUES INDICATING SOME DEPTH TO THE MOISTURE PROFILE. WHILE CONFIDENCE IN DEVELOPMENT OF THUNDERSTORMS IS HIGHER...HIGHER RES MODELS KEEPING COVERAGE FAIRLY SPARSE AND WITH LATEST HRRR JUMPING AROUND QUITE A BIT WITH TIMING AND LOCATION...DO NOT THINK POPS ABOVE THE 20-30 PERCENT RANGE WARRANTED JUST YET. WITH A LOT OF UNCERTAINTY IN THE DETAILS...HAVE GENERALLY WENT WITH BROADER COVERAGE OF POPS STARTING FIRST AROUND SFC TROUGH AROUND 20Z AND GRADUALLY SHIFTING EAST AND DIMINISHING. SOME ELEVATED INSTABILITY REMAINS THROUGH THE NIGHT WITH SOME WEAK ASCENT EXPECTED TO THE WEST OF H7 THERMAL RIDGE. PROBABILISTIC GUIDANCE NOT REALLY SUPPORTING MUCH OF A PRECIP THREAT AT THIS POINT...BUT CANNOT TOTALLY RULE OUT SOME ELEVATED OVERNIGHT STORMS AND WILL GENERALLY KEEP PREVIOUS FORECAST IN THIS REGARD. GIVEN ALREADY OBSERVED MOISTURE TRANSPORT...DO HAVE SOME CONCERNS ABOUT THE DEVELOPMENT OF FOG OVERNIGHT. WINDS SHOULD GENERALLY STAY UP WHICH WILL MINIMIZE THE THREAT SOME WHAT...BUT GIVEN EXPECTED MOISTURE PROFILE AND SREF INDICATING A SMALL THREAT FOR FOG THINK AT LEAST A PATCHY MENTION IS IN ORDER. TUESDAY...H5 RIDGE AXIS WILL SHIFT TO THE EAST THROUGH THE DAY...WITH CWA UNDER THE INFLUENCE OF LARGE SCALE FORCING FOR SUBSIDENCE THROUGH MUCH OF THE DAY. WHILE SYNOPTIC SCALE SUPPORT IS LACKING...FAIRLY STRONG AND PERSISTENT CONVERGENCE EXPECTED ALONG DRYLINE THAT WILL DEVELOP ACROSS AREA DURING THE AFTERNOON. COULD POTENTIALLY SEE A STORM OR TWO DEVELOP IN THIS AREA...BUT GIVEN LARGE SCALE PATTERN...POTENTIAL FOR A STRONG CAP AND VERY LOW PROBABILITIES FROM THE NORMALLY WET SREF DATABASE...CONFIDENCE NOT HIGH ENOUGH TO INCLUDE THUNDERSTORM THREAT AT THIS TIME. MIXED LAYER TEMPS STILL SUPPORT TEMPS IN THE 90S ACROSS MUCH OF THE AREA...ALTHOUGH THERE DOES APPEAR TO BE SOME DISCREPANCIES FOR HOW WARM THINGS WILL GET WITH SREF INDICATING A RANGE BETWEEN 97 AND AROUND 88 FOR GLD. GIVEN OVERALL PATTERN AND POTENTIAL TO BE ON MUCH DRIER SIDE OF THE DRYLINE THINK WARMER SOLUTIONS THE WAY TO AND MADE ONLY MINOR CHANGES TO GOING FORECAST. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 230 AM MDT MON MAY 21 2012 TUESDAY NIGHT-WEDNESDAY NIGHT...DRY TUESDAY NIGHT WITH A CHANCE FOR THUNDERSTORMS WEDNESDAY AFTERNOON ACROSS THE NORTHWEST PORTION OF THE AREA WHERE BETTER MOISTURE AND JET DYNAMICS OCCUR. THIS AREA OF FAVORABLE MOISTURE AND DYNAMICS REMAINS GENERALLY NORTH OF INTERSTATE 70 WHERE HIGHEST POPS WILL REMAIN. TOUGH CALL ON WEDNESDAYS HIGH TEMPERATURES. MODELS REMAIN INCONSISTENT IN THE HANDLING OF THE COLD FRONT. DIDNT MAKE ANY LARGE CHANGES FROM PREVIOUS FORECASTS AT THIS TIME AND WILL CONTINUE TO ADVERTISE LOW 80S ACROSS THE NORTH...NEAR 90 ACROSS THE SOUTH. THURSDAY THROUGH SUNDAY...A NUMBER OF SHORTWAVE TROUGHS WILL APPROACH AND MOVE OVER THE REGION AS A LONGWAVE TROUGH SLOWLY SHIFTS EASTWARD OVER THE WESTERN CONUS. THE LONGWAVE TROUGH WILL DIG SOUTHWARD FOR MUCH OF THE PERIOD BEFORE BEGINNING TO LIFT NORTHWARD DURING THE DAYTIME ON SATURDAY. THE SHORTWAVE TROUGHS WILL BRING THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS TO THE AREA FOR MUCH OF THE PERIOD. FEEL INCREASINGLY CONFIDENT ABOUT PRECIP CHANCES ON THURSDAY MORNING AS A COLD FRONT MOVES IN FROM THE NORTHWEST. GUIDANCE IS TRENDING COOLER IN NORTHEASTERN COLORADO...WHICH MAKES SENSE GIVEN THE TIMING OF THE FRONT...SO DECREASED MAX TEMPERATURES ON THURSDAY ALONG WITH NEIGHBORING OFFICES. THE POTENTIAL FOR PRECIP ON FRIDAY NIGHT INTO SATURDAY MORNING IS ALSO LOOKING BETTER AS A WARM FRONT LIFTS NORTHWARD. CONDITIONS SHOULD BE WINDY ON SATURDAY AS A SURFACE LOW DEEPENS OVER EASTERN COLORADO...BUT GUIDANCE NOW SHOWS HIGHER RELATIVE HUMIDITIES COMPARED TO YESTERDAY...SO POTENTIAL FOR FIRE WEATHER CONDITIONS LOOKS MORE LIKELY ON SUNDAY THAN SATURDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1132 AM MDT MON MAY 21 2012 VFR CONDITIONS EXPECTED FOR THE NEXT 24 HOURS AT BOTH LOCATIONS AS DEVELOPING SFC TROUGH WILL KEEP WINDS OUT OF THE SOUTH IN THE 15 TO 20 KT RANGE THROUGH THE BULK OF THE PERIOD ALTHOUGH WINDS SHOULD DIE DOWN A BIT IN THE OVERNIGHT HOURS. POTENTIAL FOR ISOLATED THUNDERSTORMS BTWN 22 AND 2Z MAINLY AT GLD AS STORMS FORM ALONG SFC TROUGH AND DRIFT EAST...BUT PROBABILITIES TOO LOW TO INCLUDE IN TAFS ATTM. && .FIRE WEATHER... ISSUED AT 121 PM MDT MON MAY 21 2012 VERY WARM AND DRY WEATHER IS EXPECTED ACROSS MUCH OF THE AREA ON TUESDAY...WITH AFTERNOON HUMIDITIES BELOW 15 PERCENT EXPECTED ALONG AND EAST OF THE COLORADO AND KANSAS STATE LINE. WESTERLY WINDS WILL GRADUALLY INCREASE IN THIS AREA TO AROUND 15 MPH IN THE AFTERNOON. WITH RECENT RAINFALL AND WINDS NOT EXPECTED TO INCREASE TO LATE IN THE AFTERNOON...OVERALL CONFIDENCE IN CRITICAL FIRE WEATHER CONDITIONS IS TOO LOW TO WARRANT A WATCH OR WARNING AT THIS POINT. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...JRM LONG TERM...007/CJS AVIATION...JRM FIRE WEATHER...JRM
AREA FORECAST DISCUSSION
NWS GRAY ME
1200 AM EDT WED MAY 23 2012 .SYNOPSIS... LOW PRESSURE TO OUR SOUTH WILL PASS EAST OF THE AREA OVERNIGHT. A COLD FRONT WILL MOVE INTO NORTHERN NEW ENGLAND BY TOMORROW MORNING AND OFFSHORE LATE TOMORROW. WEAK HIGH PRESSURE WILL MOVE INTO THE AREA THURSDAY AND FRIDAY WITH A CHANCE OF SHOWERS MAINLY INLAND. A WARM AND DRY SATURDAY IS ON TAP AS HIGH PRESSURE CRESTS OVER NEW ENGLAND...THEN A COLD FRONT IS EXPECTED TO SAG FROM WEST TO EAST OVER NEW ENGLAND SUNDAY AND MONDAY. THE FRONT IS EXPECTED TO PUSH NORTHWARD THROUGH THE AREA ON TUESDAY. && .NEAR TERM /THROUGH WEDNESDAY/... UPDATE... HAVE UPDATED THE GRIDS TO INCREASE POPS ALONG THE COAST WHERE AREAS OF LIGHT RAIN...DRIZZLE AND FOG WILL CONTINUE FOR A FEW MORE HOURS. HAVE NUDGED DEW POINTS UP A COUPLE DEGS AS WELL AS READIGNS REMAIN IN THE LWR 60S ACROSS SRN AREAS. PREV DISC... A LOW PRESSURE SYSTEM WAS CENTERED NEAR CAPE COD THIS AFTERNOON WITH A WARM FRONT ARCING INTO SOUTHERN NH AND MAINE. MOISTURE CONTINUED TO FLOW NORTH INTO THE AREA. AT THE SAME TIME A COLD FRONT WAS MOVING SLOWLY THROUGH SOUTHERN QUEBEC...NEW YORK...AND PENNSYLVANIA. AT THE MOMENT MOST OF THE HEAVIER SHOWERS WERE LOCATED OVER THE HIGHER TERRAIN OF NORTHERN COOS...FRANKLIN...OXFORD...AND SOMERSET. THE HRRR AND NAM12 INDICATE A BREAK OVER MUCH OF THE AREA TONIGHT EXCEPT FOR PERHAPS SOUTHERN NH AND SOUTHWEST MAINE WHERE MOISTURE CONVERGENCE IS BEST. STILL...EXPECT DRIZZLE AND WIDESPREAD FOG FOR MUCH OF THE REGION. AS THE COLD FRONT MOVES INTO THE NH MOUNTAINS AND WESTERN MAINE OVERNIGHT...SHOWERS WILL BECOME MORE WIDESPREAD. THERE IS SOME ELEVATED INSTABILITY BUT FELT THERE WAS NOT ENOUGH TO INCLUDE THUNDERSTORMS IN THE FORECAST. OVERNIGHT LOWS WILL BE IN THE MID 50S. && .SHORT TERM /WEDNESDAY NIGHT/... LINE OF SHOWERS WILL WORK SLOWLY SOUTHEAST TOMORROW WITH THE COLD FRONT ALONG WITH ISOLATED THUNDERSTORMS. QPF AMOUNTS WILL GENERALLY BE LIGHT HOWEVER ANY CONVECTION WILL BOOST RAINFALL TOTALS. WE WILL SEE CLEARING AND EVENTUALLY PARTLY SUNNY SKIES WORK IN FROM THE NORTH BY THE AFTERNOON. THIS WILL CONTRIBUTE TO HIGH TEMPERATURES IN THE 70S. THE BOUNDARY ESSENTIALLY STALLS AND BY WASHES OUT BY EVENING AS THE LOW PRESSURE TO OUR EAST PULLS AWAY AND WE LOSE ANY UPPER LEVEL PUSH. THIS WILL ENSURE MOISTURE HANGS AROUND IN THE LOW LEVELS. ONCE THE RAIN ENDS FOG WILL DEVELOP AND BECOME DENSE AFTER DARK. WEDNESDAY NIGHT`S LOWS WILL BE IN THE LOWER 50S NORTH TO UPPER 50S SOUTH WITH NEGLIGIBLE TEMPERATURE ADVECTION. && .LONG TERM /THURSDAY THROUGH TUESDAY/... MEDIUM RANGE MODELS ARE IN FAIR AGREEMENT IN THE GENERAL PATTERN. WEAK SURFACE HIGH PRESSURE WILL REMAIN OVER THE AREA THURSDAY AND FRIDAY...BUT SHORTWAVES ALOFT MOVING THROUGH NEW ENGLAND WILL KEEP A CHANCE OF SHOWERS EACH DAY...MAINLY INLAND. ON SATURDAY THE RIDGE OVER THE SOUTHEASTERN UNITED STATES SURGES NORTHWARD INTO NEW ENGLAND FOR A VERY WARM DAY...WITH SOME LOCATIONS IN NEW HAMPSHIRE POSSIBLY TOUCHING 90 DEGREES. THEN A WEST-EAST-ORIENTED COLD FRONT WILL SAG SOUTHWARD ACROSS THE AREA SUNDAY THROUGH TUESDAY. POSITION AND STRENGTH OF THIS BOUNDARY ARE UNCERTAIN AT THIS TIME. CAN`T RULE OUT A CHANCE OF AFTERNOON THUNDERSTORMS AND SHOWERS EACH DAY. && .AVIATION /04Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM...MOSTLY VFR CONDITIONS AT THE MOMENT WITH A BREAK IN PRECIPITATION FOR MOST TERMINALS UNTIL THE EVENING. THE EXCEPTION WILL BE PORTSMOUTH WHICH STAYS IN AN AREA OF CONVERGENCE. DRIZZLE AND FOG WILL RETURN AROUND 00Z CAUSING CEILINGS AND VISIBILITIES TO DROP AGAIN TO IFR/LIFR CATEGORIES. A COLD FRONT WILL MOVE IN FROM THE WEST TONIGHT WITH RAIN CHANCES INCREASING FROM NW TO SE THROUGH TOMORROW. LONG TERM...OCCASIONAL MVFR CONDITIONS IN SCATTERED SHOWERS THURSDAY AND FRIDAY. VFR SATURDAY THEN POSSIBLE MVFR IN ANY THUNDERSTORMS SUNDAY. && .MARINE... SHORT TERM...HAVE ISSUED A SCA FOR HIGH SEAS BEGINNING TONIGHT AND ENDING TOMORROW EVENING AS LOW PRESSURE PASSES TO THE EAST. LONG TERM...NO SIGNIFICANT FEATURES DURING THE PERIOD. && .FIRE WEATHER... SCATTERED SHOWERS AND HIGH RELATIVE HUMIDITIES WILL LAST THROUGH FRIDAY WITH A COLD FRONTAL PASSAGE AND MORE SUBSTANTIAL RAINS SATURDAY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 PM EDT WEDNESDAY FOR ANZ150-152-154. && $$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
959 PM EDT TUE MAY 22 2012 .SYNOPSIS... A WEAKENING COLD FRONT WILL CROSS THE STATE OVERNIGHT. AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL BUILD BACK OVER THE STATE ON WEDNESDAY AND REMAIN OVER THE REGION THROUGH FRIDAY. && .NEAR TERM /THROUGH WEDNESDAY/... 950 PM UPDATE: WHATS LEFT OF THE LLVL MOISTURE FLUX CNVRG ALG A WEAKENING COLD FRONT IS ENDING...ALLOWING HEAVIER SHWRS TO FINALLY REDUCE HRLY RNFL RATES INTO THE MDT AND LGT CTGRY. HRRR GUIDANCE ALG WITH OTHER LARGER DOMAIN SYNOPTIC SCALE MODELS ALSO SHOW THIS DIMINISHING TREND...BOTH IN INTENSITY AND CVRG...CONTG INTO THE LATE NGT HRS...SO ADDITIONAL HVY RNFL APPEARS VERY LIKELY ATTM. OUTSIDE OF EXTENDING SIG 00-06Z QPF AND CORRESPONDING POPS SE A LITTLE FROM THE LAST UPDATE TO INCLUDE PRESQUE ISLE...WE LOADED OBSVD 2000 LDT SFC TEMPS AND MERGED THEM TO FCST OVRNGT LOWS AT 0500 LDT WED MORN. NO OTHER CHGS NEEDED TO THE REMAINING FCST ELEMENTS FOR THE NEAR TERM ATTM. 530 PM UPDATE: UPDATED POPS TO CORRESPOND TO THE AXIS OF HEAVIEST SHWRS OVR FAR NRN PTNS OF THE FA ATTM. RADAR INDICATES THE HEAVIEST RADAR ESTIMATED RNFL ATTM BETWEEN NINE MILE BRIDGE AND CLAYTON LAKE OF NW AROOSTOOK COUNTY. OTHER NARROW BANDS OF 1 INCH PLUS RNFL ARE NEAR STOCKHOLM AND NEW CANADA OF NE AND N CNTRL AROOSTOOK COUNTY. MOVEMENT OF THIS LINE OF HVY RN SHWRS...WHICH ATTM IS TO LOW TOP FOR LGTNG IS MOVING WITH THE SLOWER SPEED ASSOCIATED WITH BACKWARD CORFIDI VECTOR MOTION WHICH ATTM IS FROM THE S AT 5 TO 10 KT. THIS MOTION SHOULD INCREASE LATER THIS EVE TO 10 TO 15 KT. THIS FASTER MOTION WITH LESS INTENSE REFS SHOULD DECREASE ANY CONCERNS OF MINOR LOCALIZED FLOODING BY THIS TM. OTHERWISE...WE LOADED OBSVD 1700 LDT SFC TEMPS AND MERGED THEM TO FCST OVRNGT LOWS AT 0500 LDT WED MORN. ORGNL DISC: WEAK LOW PRESSURE SOUTH OF THE GULF OF MAINE AND THE COLD FRONT SLOWLY MOVING OUT OF QUEBEC INTO NW MAINE WILL COMBINE TO PRODUCE CLOUDY CONDITIONS AND SHOWERS. MOST OF THE SHOWER ACTIVITY WILL BE FOCUSED ALONG THE FRONT IN ZONES 1 THROUGH 4 LATE THIS AFTERNOON AND EVENING. SOME OF THESE SHOWERS COULD BE HEAVY TOWARDS THE SJV TONIGHT WITH SLOW STORM MOTIONS ALONG THE FRONTAL BOUNDARY. A RUMBLE OF THUNDER IS POSSIBLE WITH SOME RELATIVELY WEAK ELEVATED CONVECTION AND THE ENTRANCE REGION TO A WEAK UPPER JET. SOUTH OF THE SJV...PRECIP AMOUNTS ARE EXPECTED TO TAPER TOWARDS A QUARTER INCH NEAR CARIBOU...LESS THAN A TENTH OF AN INCH NEAR HOULTON AND JUST A FEW HUNDREDTHS OF AN INCH TOWARDS BANGOR. THE BIGGEST ISSUE DOWN EAST WILL BE FOG CREEPING BACK NORTHWARD FROM THE GULF OF MAINE TOWARDS THE FRONT. WITH CLOUD COVER AND SHOWERS...LOWS TONIGHT WILL ONLY DROP INTO THE UPPER 50S EXCEPT SOME LOWER 50S ALONG THE COAST. THE FRONT WILL SLOWLY REACH DOWN EAST BY WEDNESDAY MORNING. THE CROWN OF MAINE WILL QUICKLY CLEAR OUT AND EXPERIENCE SUNSHINE WITH LOW HUMIDITY. CLOUD COVER AND HIGHER HUMIDITY WILL LINGER DOWN EAST THROUGH THE MORNING WITH A FEW SHOWERS. CLEARING SKIES SHOULD PUSH SOUTHWARD INTO DOWN EAST ZONES DURING THE AFTERNOON. HIGHS WILL REACH THE LOW 70S IN THE NORTHERN HALF OF THE FORECAST AREA AND MID 70S FOR MOST OF DOWN EAST EXCEPT THE COAST WHERE UPPER 60S TO LOW 70S ARE EXPECTED. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... A LARGE UPPER LEVEL RIDGE OF HIGH PRESSURE WILL BUILD BACK OVER THE STATE ON WEDNESDAY BRINGING MORE WARM WEATHER WHICH WILL LAST THROUGH THE END OF THE WEEK. A SOUTHERLY FLOW RESULTING FROM HIGH PRESSURE OFF TO THE EAST COMBINED WITH LOW PRESSURE LIFTING INTO THE GREAT LAKES STATES WILL ALSO BRING INCREASING HUMIDITY. THURSDAY WILL BRING PARTIAL SUNSHINE WITH A WARM AFTERNOON. SOME ISOLATED SHOWERS AND POSSIBLY A STRAY THUNDERSTORM MAY AFFECT WESTERN AREAS THURSDAY AFTERNOON AS MOISTURE LIFTS NORTH AROUND THE ATLANTIC HIGH. THURSDAY NIGHT WILL BE PARTLY CLOUDY. HUMID AIR WILL RESULT IN A WARM NIGHT. A SOUTHERLY BREEZE WILL INCREASE ON FRIDAY AS THE GRADIENT TIGHTENS AHEAD OF AN APPROACHING COLD FRONT. THE DAY WILL BE PARTLY SUNNY AND WARM AND A STRAY SHOWER OR THUNDERSHOWER WILL BE POSSIBLE IN SOME WESTERN AND SOUTHERN SPOTS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... MODELS IN FAIRLY GOOD AGREEMENT WITH COLD FRONT CROSSING THE STATE FRIDAY NIGHT WITH SHOWERS MAINLY ACROSS NORTHERN SECTIONS. HIGH PRESSURE CENTERED OVER JAMES BAY WILL THEN BUILD ACROSS THE REGION SATURDAY THROUGH SUNDAY WITH FAIR CONDITIONS. GFS IS INDICATING WEAK IMPULSE COULD PROVIDE SHOWERS ACROSS THE AREA LATE SUNDAY BUT OTHER MODELS FARTHER SOUTH WITH THIS FEATURE SO FOR NOW WILL KEEP SHOWERS EITHER CHANCE OR SLIGHT CHANCE AND CONFINED TO NORTHWEST SECTIONS AND DOWNEAST. AT THIS TIME, MEMORIAL DAY LOOKS TO BE DRY WITH NEXT LOW PRESSURE AFFECTING THE REGION MONDAY NIGHT INTO TUESDAY. && .AVIATION /22Z TUESDAY THROUGH SUNDAY/... NEAR TERM: MOIST AIRMASS AHEAD OF THE COLD FRONT WILL BRING ALL TERMINALS TO IFR TONIGHT WITH VLIFR POSSIBLE CLOSER TO THE COAST FOR LOCATIONS SUCH AS BHB AND BGR. THE COLD FRONT WILL BRING CONDITIONS TO VFR NORTH OF HUL WEDS MORNING AND VFR IS EXPECTED TO REACH BGR AND BHB BY MIDDAY. SHORT TERM: GENERALLY VFR CONDITIONS ARE EXPECTED WEDNESDAY NIGHT THROUGH FRIDAY ALTHOUGH SOME PATCHY LOW CLOUDS OR FOG MAY BRIEFLY LOWER CONDITIONS TO IFR EARLY THURSDAY MORNING OR FRIDAY MORNING. EXPECT VFR CONDITIONS FRIDAY NIGHT THROUGH SUNDAY. && .MARINE... NEAR TERM: UPDATE...BASED ON LATEST BUOY OBS WHICH ONLY SHOW WV HTS OF ARND 3 FT ON BUOYS OVR AND NEAR OUR OUTER MZS...WE OPTD TO PUSH BACK THE BEGINNING OF THE SCA FOR HAZ SEAS OVR THE OUTER MZS UNTIL 0400 AM LDT. ORGNL DISC...A SE SWELL WILL BRING LONG PERIOD WAVE HTS TO 6 FEET IN THE OUTER WATERS...MEETING SCA CRITERIA FOR HAZARDOUS SEAS. WILL ISSUE SCA FOR 11PM TONIGHT THROUGH WEDNESDAY AFTERNOON. WINDS WILL REMAIN LIGHT. SHORT TERM: WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA LEVELS WEDNESDAY NIGHT THROUGH FRIDAY. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 4 AM THIS MORNING TO 4 PM EDT WEDNESDAY FOR ANZ050-051. && $$ NEAR TERM...VJN SHORT TERM...BLOOMER LONG TERM...FOSTER AVIATION...VJN MARINE...VJN/BLOOMER
AREA FORECAST DISCUSSION
NWS GRAY ME
335 PM EDT MON MAY 21 2012 .SYNOPSIS... HIGH PRESSURE WILL MOVE EAST TONIGHT AS LOW PRESSURE TRAVELS UP THE EAST COAST. A COLD FRONT WILL APPROACH FROM THE WEST TOMORROW TRIGGERING SHOWERS AND THUNDERSTORMS. THE REMAINDER OF THE WEEK WILL BE WARM AND UNSETTLED WITH A CHANCE OF SHOWERS EACH DAY. && .NEAR TERM /THROUGH TONIGHT/... HIGH PRESSURE WILL WEAKEN OVER THE AREA TONIGHT AS LOW PRESSURE NEAR THE CAROLINA COAST MOVES NORTH. THE HIGH PRESSURE AS WELL AS DIURNAL HEATING HAS BEEN ABLE TO SUPPRESS/SLOW DOWN THE STRATUS DECK TO OUR SOUTH FOR THE MOST PART TODAY...BUT AS WE LOSE DAYTIME HEATING THIS EVENING THE WARM FRONT WILL SURGE NORTHWARD. DRIZZLE WILL START SOON AFTER ALONG THE COAST WITH TRUE RAIN MOVING IN TONIGHT. THE HRRR IS HANDLING THIS SYSTEM BETTER THAN THE NAM AND SO AM GOING CLOSER TO ITS SOLUTION IN THE FIRST FEW HOURS. AM NOT EXPECTING MUCH QPF REALLY UNTIL AFTER MIDNIGHT IN NH AND TOWARDS DAYBREAK IN MAINE. CLOUD COVER WILL KEEP OVERNIGHT LOWS IN THE MID 50S MOST SPOTS. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... PW VALUES WILL BE AROUND +2 STANDARD DEVIATIONS ABOVE NORMAL TOMORROW AS LOW PRESSURE PASSES BY TO OUR EAST DRAGGING TROPICAL MOISTURE WITH IT. A COLD FRONT WILL APPROACH OUR NORTHERN BORDERS LATE IN THE MORNING AND MOVE THROUGH NORTHERN NEW ENGLAND THROUGHOUT THE DAY. THIS WILL HELP FOCUS THE MOISTURE AND WE SHOULD SEE SOME HEAVY RAINFALL AT TIMES WITH URBAN FLOODING AT TIMES. MODELS ARE DEPICTING MORE MUCAPE THAN SURFACE BASED CAPE BUT STILL SHOULD HAVE A GOOD CHANCE AT CONVECTION. HIGH TEMPERATURES WILL RANGE FROM THE LOWER TO MID 60S NORTH TO LOWER 70S SOUTH. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... A MILD AND AT TIMES UNSETTLED PATTERN THROUGH THIS PERIOD. UPPER LEVEL RIDGE OVER THE REGION WITH A FEW DISTURBANCES MOVING NORTHEAST IN THE FLOW. WITH INCREASE TEMPS AND MOISTURE THESE DISTURBANCES SHOULD SET OFF A FEW SHOWERS. THE INCREASE IN TEMPS AND MOISTURE SHOULD ALSO RESULT IN AREAS OF FOG AND DRIZZLE ESPECIALLY ALONG COASTAL REGIONS AT NIGHT. LI`S AT OR SLIGHTLY BELOW ZERO WED AFTERNOON. ISOLATED CONVECTION POSSIBLE. BEST CHANCE OF THUNDERSTORMS APPEARS TO BE SATURDAY AHEAD OF A COLD FRONT THAT CROSSES THE AREA. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... SHORT TERM...VFR CONDITIONS WILL DETERIORATE QUICKLY AFTER DARK AS A WARM FRONT SURGES NORTH AND DRIZZLE...RAIN...AND FOG FOLLOW. CEILINGS WILL DROP AS LOW AS LIFR. VISIBILITIES WILL BE WORSE ALONG THE COAST THAN INLAND. IMPROVEMENT TO MVFR OR BETTER IS LIKELY BY AFTERNOON TUESDAY. LONG TERM...AREAS OF MVFR DURING THE DAY AND IFR NIGHT AS LOW LEVEL MOISTURE INCREASES. && .MARINE... SHORT TERM...SEAS WILL APPROACH SMALL CRAFT CONDITIONS TOMORROW NIGHT IN THE OUTER WATERS AS A COLD FRONT PUSHES OFFSHORE. LONG TERM...WIND AND SEAS EXPECTED TO REMAIN BELOW SCA LEVELS. && .FIRE WEATHER... CLOUDS AND MOISTURE WILL INCREASE TONIGHT AS A WARM FRONT LIFTS NORTH INTO THE AREA. SCATTERED SHOWERS AND HIGH RELATIVE HUMIDITIES WILL LAST UNTIL WEDNESDAY. THERE WILL BE A CHANCE OF SHOWERS WEDNESDAY THROUGH FRIDAY WITH A COLD FRONTAL PASSAGE AND MORE SUBSTANTIAL RAINS SATURDAY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ HANES/LULOFS
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
1000 AM EDT MON MAY 21 2012 .SYNOPSIS... HIGH PRESSURE WILL MOVE EAST OF THE REGION TODAY. A WARM FRONT WILL THEN MOVE NORTH...SPREADING SHOWERS INTO NORTHERN NEW ENGLAND. A COLD FRONT WILL MOVE SLOWLY EAST AND SPARK SHOWERS AND THUNDERSTORMS TUESDAY AND WEDNESDAY. HIGH PRESSURE WILL BE IN CONTROL THURSDAY AND FRIDAY. A COLD FRONT WILL TRIGGER SHOWERS AND STORMS ON SATURDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... .UPDATE... STRATUS DECK HAS REACHED SOUTHERN NH AND IS SLOWING DOWN THANKS TO DIURNAL HEATING. AREA OF CONVECTION IS WELL SOUTH OF THE AREA OVER LONG ISLAND. THE HRRR INITIALIZES WELL WITH SHOWERS BREAKING UP LATER IN THE DAY AS THEY MOVE NORTH INTO STRONG RIDGING. DRIZZLE LOOKS LESS LIKELY AND HAVE REMOVED IT FROM THE FORECAST. RAIN LOOKS TO ARRIVE CLOSER TO 03-06Z IN NH AND WORK NORTH. ALSO ADJUSTED TEMPERATURES UP SLIGHTLY ESPECIALLY OVER SOUTHERN SECTIONS. && PREVIOUS DISCUSSION...SFC RIDGING REMAINS IN CONTROL OF THE CWA...AT LEAST FOR THE EARLY PART OF THE DAY. WARM FNT IS LAYING ALONG THE S COAST OF NEW ENGLAND ATTM...AND SLOWLY LIFTING NWD. AS IT REACHES THE SRN CWA EARLY THIS AFTN...ONSHORE FLOW WILL PROMOTE LOW CLOUD AND FOG DEVELOPMENT. WEAK LIFT IN THE LWR LVLS WILL ALSO MEAN PATCHY DZ IS PSBL UNTIL DEEPER MOISTURE ARRIVES LATE IN THE AFTN AND EVE. EXPECT COOLER TEMPS TODAY AS A RESULT OF INCREASING CLOUDS. THE COOLEST LOCATIONS WILL BE ALONG THE COAST AND IN SRN NH WHERE CLOUDS AND ONSHORE FLOW BEGIN EARLIEST. EARLY SUN IN THE NRN HALF OF THE AREA WILL ALLOW HIGHS TO CLIMB INTO THE 70S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... NOCTURNAL COOLING WILL LEAD TO FURTHER LOWERING OF THE CLOUDS AND MORE FOG/DZ SE OF THE MTNS. SHRA WILL BE MOST LIKELY ALONG THE COAST. ABUNDANT CLOUD COVER WILL KEEP TNGT MILD...WITH LOWS STAYING MAINLY IN THE 50S. LOW PRES DEVELOPING S OF NEW ENGLAND WILL LIFT NWD...AND PASS OFFSHORE AS A COLD FNT APPROACHES FROM THE W. SW FLOW ALOFT AHEAD OF THE FNT WILL ENCOURAGE TROPICAL MOISTURE TO THE E OF T.S. ALBERTO TO SURGE TOWARDS THE REGION. PWAT VALUES WILL INCREASE LATE TNGT INTO TUE...NEARING 1.5 INCHES AT TIMES. THESE TYPES OF VALUES ARE APPROACHING +2SD FOR THIS AREA...AND COUPLED WITH WARM CLOUD DEPTHS IN EXCESS OF 10KFT...BRIEF PDS OF HEAVY RAFL WILL BE PSBL. MODEL GUIDANCE HAS BEEN SLOW TO LATCH ONTO HEAVIER QPF...BUT THE 20/12Z ECMWF HAS ENHANCED PCPN TO THE N OF THE COASTAL LOW PRES. IT ALSO SEEMED A LITTLE TOO AGGRESSIVE ON LOW PRES DEVELOPMENT...SO A COMPROMISE WAS USED. WITH DEEP MOISTURE AND COLD FNT APPROACHING FROM THE W...STILL FEEL THAT HEAVIER RAIN WILL GET SQUEEZED OUT OF THE SYSTEM SOMEWHERE. THE PROGRESSIVE NATURE OF THE FEATURES WILL PRECLUDE ANY HYDRO ISSUES AS THINGS STAND RIGHT NOW. AHEAD OF THE COLD FNT...SOME DIURNAL HEATING AND STEEPER LAPSE RATES COULD PRODUCE ENOUGH INSTABILITY FOR THUNDER. MOST LIKELY AREAS WOULD BE IN THE CT RIVER VALLEY AND NRN MTNS. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... A BROAD SOUTHEAST FLOW BOTH AT THE SURFACE AND ALOFT WILL CONTINUE FROM WELL OUT INTO THE OPEN ATLANTIC EARLY TUESDAY EVENING. THIS WILL ALLOW FOR MOISTURE TO CONT TO POOL ACROSS THE REGION...WITH THE THICKEST CLOUD COVER AND POSSIBLY SOME PATCHY FOG RIGHT ALONG THE SHORELINE. BY LATE TUESDAY NIGHT...A WEAK TROUGH OF LOW PRESSURE WILL PASS TO OUR EAST. THIS WILL BRING SLIGHTLY DRIER AIR INTO OUR REGION...ALLOWING FOR OUR POPS TO LOWER AS WELL. HOWEVER DURING THE DAY WEDNESDAY...THE FLOW BECOMES ALIGNED OUT OF THE SSE ONCE AGAIN. THIS WILL ALLOW FOR WARM...MUGGY CONDS WITH INCREASING DEW POINTS AND JUST A SLGT CHC FOR A SHOWER DURING THE PERIOD. THIS WILL HOLD TRUE FOR THU AND FRI. THEREAFTER...A STG COLD FRONT ENTERS THE REGION BY SATURDAY. HAVE ADDED A CHC FOR A TSTM DURING THIS PERIOD AS THE ATMOS BECOMES MORE UNSTABLE WITH TIME. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... SHORT TERM...WARM FNT WILL LIFT INTO THE AREA DURING THE DAY TODAY. VFR CONDS WILL GIVE WAY TO MVFR...AND EVENTUALLY IFR OR LOWER CONDS AS LOW CLOUDS AND FOG MOVE ONSHORE IN SE FLOW. EXPECT KCON AND ESPECIALLY KPSM TO DETERIORATE IN THE EARLY AFTN...WITH KPWM/KAUG/KRKD FOLLOWING IN THE LATE AFTN/EVE. KLEB AND KHIE WILL REMAIN VFR THE LONGEST...WITH MVFR CONDS PSBL LATE TNGT. LONG TERM...MVFR CEILINGS AND VISIBILITIES ARE POSSIBLE TUESDAY NIGHT AND WEDNESDAY IN SHOWERS AND FOG AS A FRONT MOVES THROUGH THE AREA. VFR CONDITIONS ARE EXPECTED THURSDAY THROUGH FRIDAY. && .MARINE... SHORT TERM...WINDS AND SEAS EXPECTED TO REMAIN BLO SCA THRESHOLDS TODAY. LOW PRES PASSING SE OF THE WATERS TUE WILL BUILD SEAS ABOVE 5 FT ON THE OUTER WATERS DURING THE DAY. WINDS MAY BRIEFLY APPROACHING 25 KT IF LOW PRES CAN TRACK FURTHER INTO GULF OF MAINE. LONG TERM...WINDS AND SEAS SHOULD REMAIN BELOW SCA CRITERIA THROUGH THURSDAY. && .FIRE WEATHER... SUNNY AND DRY START TO THE DAY WILL GIVE WAY TO INCREASING CLOUDS AND MOISTURE AS A WARM FRONT LIFTS NORTH INTO THE AREA. SCATTERED SHOWERS AND HIGH RELATIVE HUMIDITIES WILL LAST UNTIL WEDNESDAY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ UPDATE...HANES
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
713 PM EDT TUE MAY 22 2012 .SYNOPSIS... ISSUED AT 430 PM EDT TUE MAY 22 2012 WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM THE GULF OF ALASKA INTO THE NW CONUS AND A FLAT DOWNSTREAM RIDGE FROM THE SRN PLAINS TO THE UPPER MS VALLEY RESULTING IN WRLY FLOW THROUGH THE NRN GREAT LAKES. AT THE SFC...A RIDGE EXTENDED FROM JAMES BAY THROUGH ERN LAKE SUPERIOR AND LAKE MI INTO THE MID MS VALLEY. SRLY WINDS WERE INCREASING FROM THE PLAINS INTO MN AHEAD OF LOW PRES OVER THE WRN DAKOTAS. RADAR AND SFC OBS INDICATED AN AREA OF MAINLY VIRGA/-SHRA/SPRINKLES OVER WRN UPPER MI SUPPORTED BY 305K-310K ISENTROPIC LIFT. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 430 PM EDT TUE MAY 22 2012 TONIGHT...EXPECT THAT THE -SHRA/SPRINKLES WILL CONTINUE TO DIMINISH AS THEY MOVE TO THE EAST LATE THIS AFTERNOON AND EVENING. WITH THE INCREASED CLOUD COVER AND SOUTHERLY WINDS TONIGHT...TEMPS WILL ONLY DROP OFF INTO THE MID 40S INLAND AND LOWER TO MID 50S FOR DOWNSLOPE LOCATIONS OVER THE WEST HALF. WEDNESDAY...AS THE HIGH OVER THE LAKE AND THE PLAINS TROUGH SHIFTS TO THE EAST...THE GRADIENT WILL INCREASE ACROSS UPPER MICHIGAN. THE MODELS WERE IN GOOD AGREEMENT IN KEEPING THE MOISTURE/LIFT AHEAD OF THE MID LEVEL AND SFC TROUGH TO THE WEST...GRADUALLY SHIFTING INTO WRN LAKE SUPERIOR LATE. WITH THE WAA AND SUNSHINE...TEMPS SHOULD CLIMB INTO THE MID AND UPPER 70S INLAND WITH COOLER READINGS NEAR LAKE MICHIGAN. MIXING SHOULD ALSO ALSO A DECENT PORTION OF THE 25-30 KT SRLY 925 MB WINDS TO MIX TO THE SFC. INCREASED WILDFIRE DANGER IS EXPECTED WITH THE COMBINATION OF 15 TO 20 MPH SFC WINDS AND GUSTS TO 30 MPH ALONG WITH RH VALUES DROPPING TO AROUND 30 PERCENT. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 430 PM EDT TUE MAY 22 2012 THE PERIOD STARTS 00Z THU WITH A 500MB RIDGE OVER THE E COAST AND LOWER GREAT LAKES...AND A 500MB TROUGH OVER FROM HUDSON BAY TO SRN SASK TO THE CENTRAL ROCKIES. THIS PUTS THE CWA UNDER SW FLOW ALOFT. AT THE SFC...A 994MB LOW WILL BE OVER FAR WRN ONTARIO...WITH A TROUGH/COLD FRONT EXTENDING SW TO A 986MB LOW OVER ERN CO/WRN KS. SFC HIGH PRESSURE OVER THE ERN SEABOARD COMBINED WITH LOW PRESSURE TO OUR W WILL MAKE FOR GUSTY SLY WINDS...WITH 850MB WINDS OF 35-50KTS. MOST OF THE MOISTURE OVER THE CWA WILL EXIST OVER FAR WRN LAKE SUPERIOR AT 00Z THU...WITH 1000-500MB RH AROUND 30 PERCENT OVER CENTRAL UPPER MI. 850MB TEMPS AROUND 18C AT 00Z THU WILL MAKE FOR WARMER THAN NORMAL TEMPS. CONVECTION SHOULD BE ONGOING OVER WRN LAKE SUPERIOR AS LOW LEVEL WARM AIR/MOISTURE ADVECTION NOSES INTO THE VERY MOIST AIRMASS. BY 12Z THU...THE ONTARIO SFC LOW WILL HAVE MOVED TO JAMES BAY...WHILE THE CO/KS LOW WILL HAVE BECOME AN ELONGATED LOW FROM KS TO CENTRAL MN AS AN UPPER SHORTWAVE TROUGH MOVES TO CENTRAL NE. PRECIP WED NIGHT SHOULD CONTINUE OVER WRN LAKE SUPERIOR AS LOW LEVEL WARM AIR/MOISTURE ADVECTION CONTINUES TO BE FOCUSED OVER THIS AREA. WARM AIR ADVECTION DOES LOOK TO SPREAD ACROSS MOST OF THE CWA...BUT WITH VERY DRY AIR OVER ALL BUT FAR WRN UPPER MI...PRECIP WILL NOT FOLLOW IT E. THE 12Z/22 GFS CONTINUES TO MOVE THE MOISTURE /AND THEREFOR THE PRECIP/ A LITTLE FARTHER E /OVERSPREADING MUCH OF WRN UPPER MI/ WED NIGHT...BUT WILL GO WITH MOST OTHER MODELS IN KEEPING IT FARTHER W...WHICH MAKES SENSE GIVEN DRY CONDITIONS AND RIDGING IN PLACE TO THE E. WED NIGHT LOW LOOK QUITE WARM GIVEN 850MB TEMPS STAYING AROUND 17C AND BREEZY S/SSE SFC WINDS. LOW OVER WRN UPPER MI...WHERE IT WILL BE CLOUDIER...MAY NOT FALL BELOW 60...WITH LOWS AOA 50 ELSEWHERE. FOR THU...THE SHORTWAVE MOVES TO NEAR WRN UPPER MI LATE IN THE DAY...BRINGING 992MB SFC LOW TO FAR WRN LAKE SUPERIOR/MN ARROWHEAD BY 00Z FRI. PRECIP WILL REMAIN CONFINED TO FAR WRN UPPER MI/WRN LAKE SUPERIOR THROUGH 00Z FRI...WITH STRONG SLY LOW LEVEL FLOW CONTINUING TO BRING DRY AIR TO CENTRAL AND ERN UPPER MI. HIGH TEMPS THU LOOK TO BE WARMEST OVER THE WRN HALF OF THE U.P. /EXCEPT NEAR IWD DUE TO INCREASED CLOUD COVER/ IN THE MID TO UPPER 80S. OVER ERN UPPER MI...HIGHS WILL RANGE FROM THE UPPER 60S NEAR LAKE MI TO AROUND 80 NEAR LAKE SUPERIOR. SFC WIND GUSTS AOA 30MPH LOOK COMMON ON THU...WHICH WILL TURN ATTENTION TO FIRE WEATHER AS RH FALLS TO AROUND 30 PERCENT OVER ALL BUT FAR WRN UPPER MI AND NEAR LAKE SUPERIOR. MUCAPE AROUND 1000J/KG...0-1KM BULK SHEAR AROUND 40KTS...AND 0-6KM BULK SHEAR AOA 50KTS WILL BE SUPPORTIVE OF STRONG TO SEVERE THUNDERSTORMS OVER WESTERN UPPER MICHIGAN LATE THU AFTERNOON/EVENING...MAINLY ALONG AND JUST BEHIND THE COLD FRONT. MAIN SEVERE WX THREATS WOULD BE LARGE HAIL/DAMAGING WINDS. BY 06Z FRI...MODELS SHOW THE SHORTWAVE/SFC LOW NEAR NRN LAKE SUPERIOR...WITH THE COLD FRONT OVER CENTRAL OR WRN UPPER MI. THIS SHOULD BRING WIDESPREAD SHOWERS AND THUNDERSTORMS TO WRN UPPER MI...BUT COVERAGE WILL DIMINISH AS PRECIP HEADS E INTO THE DRIER AIR IN PLACE. COLD FRONT SHOULD BE EXITING ERN UPPER MI SHORTLY AFTER 12Z FRI...WITH THE GFS SHOWING QUICKER EASTWARD PROGRESS WITH THE FRONT THAN MOST OTHER MODELS...SO WILL NOT USE AS FAST A SOLUTION AS THE GFS. 500MB HIGH BUILDS INTO THE SRN MISSISSIPPI VALLEY BY 12Z SAT AS A 500MB LOW PUSHES INTO THE SW CONUS. A RIDGE FROM THE UPPER HIGH WILL EXTEND OVER THE DAKOTAS AND MONTANA AT 12Z SAT...BUT WILL MOVE TO THE WRN CWA BY 18Z SUN AS THE UPPER LOW MOVES TO MT. THIS BRINGS THE COLD FRONT BACK N AS A WARM FRONT LATE SAT INTO SUN AS A 998MB SFC LOW MOVES TO SD. PRECIP LOOKS TO MOVE S TO N ACROSS THE CWA SAT NIGHT THROUGH SUN. MODELS BEGIN TO QUICKLY DIVERGE ON A SOLUTION PAST SUN AS THE 00Z/22 ECMWF KEEPS THE UPPER LOW OVER MT/SRN SASK THROUGH MON NIGHT...ANS THE GFS MOVES IT TO JAMES BAY BY 12Z TUE. WILL USE CONSENSUS OF MODELS FOR SAT THROUGH NEXT TUE...WITH THE FORECAST BECOMING INCREASINGLY UNCERTAIN SUN NIGHT THROUGH TUE. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 712 PM EDT TUE MAY 22 2012 WARM ADVECTION MID CLOUDS SHOULD GRADUALLY LIFT NORTH LATE TONIGHT WITH THE MVMT OF A WARM FRONT NORTH INTO CANADA. EXPECT VFR CONDITIONS TO PREVAIL WITH PLENTY OF LLVL DRY AIR THROUGH THE FCST PD. TNGT...EXPECT LLWS AT BOTH KIWD AND KCMX UNDER A TIGHTENING SRLY PRES GRADIENT AHEAD OF LOW PRES SYSTEM OVER THE NORTHERN PLAINS. DAYTIME HEATING AND MIXING WILL ALLOW FOR STRONGER SRLY WINDS TO REACH THE SFC...GUSTING AOA 25 AT BOTH KIWD AND KSAW. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 430 PM EDT TUE MAY 22 2012 SRLY WINDS WILL INCREASE TONIGHT INTO WED AS HIGH PRES SHIFTS TO THE EAST. EXPECT S WINDS UP TO 25-30 KTS WED INTO THURSDAY NIGHT UNDER SHARPENING PRES GRADIENT BETWEEN THE DEPARTING HIGH AND A SLOWLY APPROACHING LO PRES TROF FROM THE W. THE STRONGEST WINDS ARE EXPECTED OVER CENTRAL LAKE SUP...WHERE TERRAIN INFLUENCE MAY ENHANCE THE S WIND. THE WIND AT HIGHER PLATFORMS SUCH AS STANNARD ROCKS MAY ALSO EXCEED 35 KTS...BUT THE HIGH STABILITY OVER THE RELATIVELY COOL LAKE WATERS WILL PREVENT THESE STRONGER WINDS FROM MIXING TO THE SURFACE. LOOK FOR LIGHTER WINDS UNDER 20 KTS ON FRI/SAT WITH A RELATIVELY WEAK PRES GRADIENT ASSOCIATED WITH HIGH BUILDING INTO THE REGION FOLLOWING A COLD FRONTAL PASSAGE ON FRI. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...JLB SHORT TERM...JLB LONG TERM...TITUS AVIATION...VOSS MARINE...JLB
AREA FORECAST DISCUSSION
NWS BILLINGS MT
931 PM MDT TUE MAY 22 2012 .SHORT TERM...VALID FOR WED AND THU... WE UPDATED THE FORECAST TO REDUCE POPS FOR THE PLAINS OVERNIGHT. A DRY PERIOD IS EVEN BEING ADVERTISED FOR SOME PLACES LIKE BILLINGS. THE BATCH OF SHOWERS THAT EXTENDS FROM WOLF POINT SOUTHWARD TO THE MILES CITY AND SHERIDAN AREAS AS OF 03 UTC APPEARS ASSOCIATED WITH FRONTOGENESIS BASED IN THE 700-500 HPA LAYER. THE LAST SEVERAL RAP SOLUTIONS AND THE 00 UTC NAM ALL TAKE THIS FORCING EAST OUT OF THE AREA AFTER 06 UTC. ADD IN THE DIURNAL STABILIZATION THAT IS SURELY ALREADY HELPING REDUCE CONVECTIVELY-DRIVEN SHOWERS...AND DRYING OF THE AIR MASS THAT/S ALSO ADVERTISED BY MODELS...AND SHOWER CHANCES COME INTO DOUBT ON THE PLAINS OVERNIGHT. SIMPLE NUDGING OF POPS TO THE 00 UTC NAM...18 UTC GFS...AND LAST SEVERAL RAP SOLUTIONS MEANT REDUCING POPS. OF COURSE...SOUTHWESTERLY FLOW ALOFT WILL REMAIN IN PLACE OVERNIGHT...AND SOME WEAK ENERGY IN THAT REGIME IS RESULTING IN A FEW SHOWERS BACK ACROSS IDAHO. THUS...SOME 20 TO 30 POPS WILL BE NEEDED FOR PLACES LIKE LIVINGSTON...WITH LIKELY POPS ACROSS THE MOUNTAINS. SCHULTZ .LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE... THE EXTENDED FORECAST APPEAR TO BE IN PRETTY GOOD SHAPE FOR THE MOST PART...FAVORING A COOL AND WET HOLIDAY WEEKEND AND EARLY WEEK. MODELS HAVE COME BACK INTO AGREEMENT ON AMPLIFIED SOLUTION TO UPPER LOW MOVING ACROSS THE REGION...AND INDICATE SIGNIFICANT PRECIP...AND SNOW IN THE MOUNTAINS. THE UPPER LEVEL LOW PRESSURE SYSTEM WILL LIFT NORTH INTO THE REGION ON FRIDAY...AND DOMINATE THE PATTERN THROUGH EARLY SUNDAY...AS UPPER LEVEL HIGH PRESSURE SYSTEM CENTERED IN THE SOUTHEAST CONUS BLOCKS EASTWARD PROGRESSION. THIS SUPPORTS A DEEP SOUTHERLY DIFFLUENT FLOW OVER THE AREA THROUGH SATURDAY. A SFC LOW ALSO DEVELOPS OVER WYOMING SUPPORTING THE DEVELOPMENT OF STRONG ISENTROPIC LIFT IN THE LOWER LEVELS. EASTERLY SFC FLOW WILL ALSO SETUP UPSLOPE INTO AREA MOUNTAINS AND FOOTHILLS. HAVE INCREASED POPS SLIGHTLY IN UPSLOPE REGIONS AND IN THE HIGHER TERRAIN SOMEWHAT. SNOW WILL BE A CONCERN...ESPECIALLY FOR THE HIGH TERRAIN....EARLY FRIDAY MORNING AND AND AGAIN FRIDAY NIGHT...AS COLD AIR PUSHES INTO THE AREA. MOST RECENT CROSS SECTIONS INDICATE 0C LEVELS EVEN LOWER THAN PREVIOUSLY ADVERTISED. THEREFORE RAIN/SNOW MIX MAY BE POSSIBLE IN KLVM AND KBIL FRIDAY NIGHT...WITH SIGNIFICANT ACCUMULATING SNOW IN THE HIGH TERRAIN...AND SOME ACCUMULATION POSSIBLE IN RED LODGE AND SIMILAR ELEVATIONS. THE LOW LIFTS NORTH AND EAST OUT OF THE REGION SUNDAY...BUT LOOKS LIKE IT IS SLOW MOVING ENOUGH AT THIS TIME TO KEEP PRECIP IN THE REGION THROUGH THE MORNING AND AFTERNOON. DOWNSLOPE FLOW LOOKS LIKE IT SHOULD KICK IN TO CLEAR OUT THE AREA BY SUNDAY EVENING. HAVE COOLED TEMPS FOR FRIDAY THROUGH SUNDAY...IN RESPONSE TO EXTENSIVE PRECIP/CLOUD COVER...AND CAA. MODELS DIVERGE A BIT ON HOW THEY HANDLE THE REMAINDER OF THE PERIOD...WITH EC REMAINING SOMEWHAT ZONAL AND KEEPING LINGERING POPS THROUGH MONDAY NIGHT...WITH ANOTHER TROF INTO THE AREA BY TUESDAY NIGHT. GFS SUPPORTS A QUICK RETURN TO SHALLOW RIDGING FOR MONDAY...BUT ALSO BRINGS ANOTHER TROF THROUGH THE REGION TUESDAY EVENING. HAVE MAINTAINED SLIGHT POPS THROUGH THE PERIOD...WITH SLIGHT INCREASE FOR TUESDAY. HAVE CONTINUED WARMING TREND THROUGH THE REMAINDER OF THE PERIOD...BUT COOLED TEMPS SLIGHTLY THROUGHOUT THE PERIOD...WITH POTENTIAL FOR CONTINUED SCATTERED CLOUD COVER AND SHOWERS. AAG && .AVIATION... SCATTERED SHOWERS FROM ROSEBUD COUNTY THROUGH BIG HORN COUNTY E...WILL PERSIST THROUGH 06Z WITH MVFR CONDITIONS. EXPECT WIDESPREAD OBSCURATIONS OVER THE ABSAROKA...BEARTOOTH AND NE BIG HORN MOUNTAINS. THE SHOWERS WILL BECOME WIDELY SCATTERED WITH LOCALIZED MVFR CONDITIONS OVERNIGHT. MORE SHOWERS WILL MOVE INTO THE WESTERN MOUNTAINS AND ADJACENT FOOTHILLS OVERNIGHT AS WELL. CHANCES FOR SHOWERS WILL SPREAD E THROUGH THE DAY ON WED WITH POSSIBLE AFTERNOON THUNDERSTORMS. SOME OF THE PRECIPITATION MAY PRODUCE MVFR CONDITIONS. AREAS OF MOUNTAIN OBSCURATION OVERNIGHT WILL BECOME MORE WIDESPREAD ON WED. ARTHUR && .PRELIMINARY POINT TEMP/POPS... WED THU FRI SAT SUN MON TUE ----------------------------------------------------------- BIL 046/062 042/058 038/051 039/052 037/061 040/067 044/068 13/T 34/W 45/T 76/T 54/T 22/T 22/W LVM 039/055 034/053 033/047 033/050 029/057 034/065 035/066 34/T 35/W 56/T 66/T 65/T 22/T 33/W HDN 045/064 042/060 037/054 040/057 038/063 040/068 043/071 23/T 44/W 45/T 66/T 54/T 32/T 22/W MLS 049/066 044/061 038/054 042/057 040/063 041/068 043/071 32/W 23/W 34/T 65/T 54/T 32/T 22/W 4BQ 048/064 043/060 039/053 043/060 039/064 040/070 042/073 42/W 22/W 34/T 75/T 54/T 32/T 22/W BHK 047/064 041/062 035/055 043/055 040/065 040/068 041/071 41/N 23/W 34/T 65/T 54/T 32/T 22/W SHR 043/060 039/055 035/052 038/058 036/061 036/066 038/071 34/T 33/W 45/T 86/T 63/T 22/T 22/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1221 PM CDT MON MAY 21 2012 .AVIATION...18Z KGRI TAF. VFR CONDITIONS ARE EXPECTED THROUGHOUT THE ENTIRE TAF PERIOD. THE MAIN CONCERN FOR THE PERIOD WILL FOCUS ON INCREASED SOUTHERLY WINDS DURING THE MORNING AND AFTERNOON HOURS TUESDAY. DEVELOPING LOW PRESSURE ALONG THE FRONT RANGE OF THE ROCKIES MOUNTAINS WILL SLIDE EASTWARD OVERNIGHT TONIGHT. THIS WILL HELP INCREASE THE PRESSURE GRADIENT ACROSS THE PLAINS. COMBINED WITH BOUNDARY LAYER MIXING...SUSTAINED SOUTH WINDS NEAR 20 TO 25 KTS WILL BE POSSIBLE WITH GUSTS NEAR 30 KTS. OVERNIGHT THIS EVENING...THE LOW LEVEL JET WILL ALSO KICK UP ACROSS THE PLAINS. THIS MIGHT PROVIDE A WIND SHEAR THREAT DURING THE OVERNIGHT HOURS. HOWEVER...AT THIS TIME DECIDED TO KEEP MENTION OF LOW LEVEL WIND SHEAR OUT OF THE TAF...AS WINDS OVERNIGHT ARE EXPECTED TO REMAIN AROUND 10 TO 15 KTS. && .PREV DISCUSSION... /ISSUED 1034 AM CDT MON MAY 21 2012/ UPDATE...LIGHT SHOWERS HAVE BEGUN TO DISSIPATE ACROSS THE FORECAST AREA. PREV DISCUSSION... /ISSUED 447 AM CDT MON MAY 21 2012/ SHORT TERM...ALTHOUGH THE MAJORITY OF THE NEXT 72 HOURS SHOULD REMAIN DRY...WILL HAVE TO DEAL WITH AT LEAST SOME SPRINKLES/BRIEF SHOWERS THIS MORNING MAINLY IN THE NORTH...AND EVENTUALLY WHAT SHOULD BE A MORE WIDESPREAD THUNDERSTORM RISK IN SOME AREAS WEDNESDAY EVENING/NIGHT. ALSO OF CONCERN IS POSSIBLE ADVISORY-LEVEL SOUTHERLY WIND ON TUESDAY. 08Z OBJECTIVE SURFACE ANALYSIS PLACES A BROAD 1025MB RIDGE AXIS ACROSS EASTERN NEB...PROVIDING NEAR CALM TO VERY LIGHT EAST/SOUTHEAST BREEZES TO THE CWA. ALTHOUGH MID LEVEL CLOUDS WILL BE ON THE INCREASE THROUGH SUNRISE...MAINLY CLEAR SKIES THUS FAR TONIGHT HAVE RESULTED IN AN EFFICIENT COOL DOWN INTO THE MID/UPPER 40S IN MOST AREAS. SPEAKING OF THOSE INCOMING MID CLOUDS AND INCORPORATING RADAR TRENDS...SURE ENOUGH AND AS SUSPECTED HERE 24 HOURS AGO...A NARROW NORTH-SOUTH BAND OF MID-LEVEL THETA-E ADVECTION EVIDENT AT 700MB HAS SPARKED AN AREA OF AT THE VERY LEAST SCATTERED SPRINKLES/LIGHT SHOWERS AND EVEN A FEW WEAK THUNDERSTORMS THAT HAVE SO FAR LARGELY STAYED JUST OUTSIDE THE CWA ALONG AN AXIS FROM NEAR VALENTINE TO NORTH PLATTE. WATER VAPOR IMAGERY CONFIRMS BROAD NORTHWEST FLOW ALOFT OVER THE CENTRAL PLAINS...AS THE REGION LIES ALONG THE NORTHEAST PERIPHERY OF A BUILDING MID/UPPER RIDGE AXIS EXTENDING ALL THE WAY BACK TO THE PACIFIC NORTHWEST...WHERE THE NEXT LARGER SCALE SHORTWAVE/UPPER JET STREAK OF INTEREST IS ARRIVING ON THE SCENE. THE IMMEDIATE ISSUE THROUGH AT LEAST THE NEXT 4-6 HOURS IS THE EVOLUTION OF DEVELOPING SHOWER ACTIVITY THIS MORNING. THIS NARROW CORRIDOR OF HIGH BASED CONVECTION IS CLASSICALLY LOCATED ALONG THE LEADING EDGE OF 700MB THETA-E ADVECTION...AND IMMEDIATELY EAST OF THE CORE OF THE 850MB LOW LEVEL JET CURRENTLY CENTERED FROM FAR WESTERN KS INTO WESTERN NEB. AS USUAL...DETERMINISTIC MODELS SUCH AS NAM/GFS/ECMWF ARE STRUGGLING TO FULLY CAPTURE THIS ACTIVITY IN THEIR QPF FIELDS...WHILE HIGHER RESOLUTION SHORT TERM MODELS SUCH AS THE HRRR AND 0Z 4KM WRF-NMM ARE PROVING BETTER. OBJECTIVE RUC ANALYSIS AND 06Z NAM CONFIRM THAT ELEVATED MUCAPE VALUES MAINLY IN THE 800-650MB LAYER ARE ONLY RUNNING A MEAGER 100 J/KG OR SO. FOLLOWING THE 06Z NAM...THIS BAND OF MID LEVEL THETA-E ADVECTION SHOULD CONTINUE TO STEADILY TRACK EAST MAINLY ACROSS THE NORTHERN 1/2 OF NEB THROUGH THE MORNING HOURS...AT LEAST PUTTING PARTS OF THE NORTHERN CWA IN LINE FOR NUISANCE AND UNFORTUNATELY PREVIOUSLY UN-ADVERTISED PRECIPITATION. HAVE DEBATED BETWEEN GOING WITH A MEASURABLE POP/SHOWER AND MAYBE EVEN AN ISOLATED THUNDERSTORM MENTION...BUT AT LEAST TO START OUT WITH THIS MORNING WILL TRY...REPEAT TRY...TO GET AWAY WITH ONLY SCATTERED SPRINKLE MENTION ALONG AND NORTH OF I-80 WITH EXPECTATION THAT MEASURABLE PRECIP SHOULD NOT BE OVERLY WIDESPREAD. STAY TUNED FOR POSSIBLE UPDATES HOWEVER AS RADAR TRENDS EVOLVE. OBVIOUSLY EVEN IF ANY ROGUE LIGHTNING STRIKES TO MANAGE TO SNEAK IN...WOULD NOT ANTICIPATE ANYTHING CLOSE TO BEING SEVERE...WITH EVEN SMALL HAIL HARD TO COME BY. WITH EXPECTATION OF THIS BEING A MORNING-ONLY ISSUE...HAVE NO PRECIP MENTION WITHIN THE CWA BEYOND 17Z...AS THE AFTERNOON HOURS WILL FEATURE THE PRIMARY LOWER LEVEL INSTABILITY AXIS SETTING UP WEST OF THE CWA ALONG AN AXIS FROM FAR WESTERN KS NORTHWARD INTO WESTERN NEB. MEANWHILE...SOUTH/SOUTHEAST WIND WILL BE ON THE INCREASE AS THE DAY WEARS ON...AS THE SURFACE RIDGE AXIS DEPARTS EAST INTO IA/MO. AS A RESULT...THE AFTERNOON HOURS WILL FEATURE SUSTAINED SPEEDS RANGING FROM NEAR 15 MPH IN FAR EASTERN COUNTIES...TO 20-25 MPH IN SOME WESTERN AREAS ALONG WITH GUSTS TO AROUND 30 MPH. TEMP WISE TODAY...CHANGED HIGHS LITTLE FROM PREVIOUS FORECAST...AND FOLLOWED 0Z NAM RAW TEMPS QUITE CLOSELY. ALTHOUGH PASSING MID LEVEL CLOUDS THIS MORNING COULD PUT A TEMPORARY DELAY ON THE DIURNAL CLIMB...HAVE AIMED MOST OF THE CWA INTO THE 77-81 RANGE FOR EVENTUAL HIGHS. THIS EVENING/TONIGHT...ANY STORMS THAT MANAGE TO FORM OUT IN WESTERN NEB LATE THIS AFTERNOON WITHIN THE INSTABILITY AXIS SHOULD STEADILY FADE AWAY LONG BEFORE MAKING IT INTO THE CWA. THAT BEING SAID...HAVE OPTED TO DISREGARD THE 00Z GFS SOLUTION WHICH BREAKS OUT WIDESPREAD QPF TONIGHT MAINLY IN SOUTHWEST/CENTRAL KS...BUT ALSO BRUSHING UP INTO THE KS ZONES OF OUR CWA. WITH THE NAM/ECMWF AND 4KM WRF-NMM ESSENTIALLY SHOWING NOTHING OF THIS NATURE...IT JUST SEEMS TOO MUCH AN OUTLIER AND HAVE KEPT THE ENTIRE CWA PRECIP-FREE TONIGHT. ALOFT...THE HEART OF THE MID/UPPER RIDGE AXIS WILL SET UP OVER THE CENTRAL PLAINS TONIGHT...AS THE UPSTREAM TROUGH/JET STREAK START CROSSING THE NORTHERN ROCKIES. AT THE SURFACE...STEADY SOUTHERLY BREEZES SHOULD HELP HOLD TEMPS UP ABOUT 10 DEGREES WARMER THAN THOSE THIS MORNING...AND HAVE MOST OF THE CWA IN THE 55-58 RANGE FOR LOWS...WHICH IS VERY SLIGHTLY WARMER THAN PREVIOUS FORECAST. TUESDAY IS STILL SHAPING UP TO BE THE WARMEST DAY OF THE WEEK...WITH PLENTY OF SOUTHERLY WIND TO GO WITH IT. STARTING WITH STORM CHANCES...HAVE KEPT IT STORM FREE THROUGH THE DAY...AS EVEN THOUGH DEWPOINTS WILL BE IN THE INCREASE INTO THE 50S IN MOST AREAS WITH A CORRESPONDING INCREASE IN LOW LEVEL INSTABILITY...MID LEVEL TEMPS WILL ALSO BE ON THE INCREASE...WITH NAM SOUNDINGS CONFIRMING A DECENT CAPPING INVERSION. BY LATE AFTERNOON...THE NAM/GFS/ECMWF ARE IN GENERAL AGREEMENT SETTING UP A 990-994MB LOW IN FAR WESTERN NEBRASKA...WITH PRESSURE FALLS DURING THE DAY SETTING UP QUITE A HEALTHY EAST-WEST SURFACE PRESSURE GRADIENT DURING THE DAY. THIS GRADIENT...IN TANDEM WITH SHOULD BE PLENTY OF SUN AND MIXING TO AT LEAST THE 800MB LEVEL SHOULD HELP CRANK UP THE SOUTHERLY WIND. TAKING A CONSENSUS OF 00Z MET/MAV GUIDANCE FOR SPEEDS...HAVE MOST OF THE CWA CURRENTLY TOPPING OUT IN THE 25-30 MPH RANGE FOR SUSTAINED SPEEDS...WHICH IF IT WERE TO HOLD WOULD GENERALLY FALL JUST SHORT OF WIND ADVISORY CRITERIA. HOWEVER...COULD EASILY FORESEE AT LEAST WESTERN PORTIONS OF THE CWA ENDING UP WITH HIGHER SPEEDS OVER 30 MPH...AND ALTHOUGH WILL FOREGO ANY HEADLINE ISSUANCE STILL BEING 3 PERIODS OUT...WILL CONTINUE TO HIGHLIGHT AT LEAST NEAR-ADVISORY SPEEDS IN THE HWO. CERTAINLY GUSTS TO AROUND 40 MPH SHOULD BE COMMON NO MATTER WHAT DURING THE AFTERNOON. TEMP-WISE...AGAIN LEANED HEAVILY ON RAW 0Z NAM NUMBERS...WHICH RESULTED IN LITTLE CHANGE FROM PREVIOUS ACROSS EASTERN ZONES...BUT ACTUALLY A SLIGHT LOWERING IN WESTERN AREAS. THIS RESULTS IN MOST AREAS TOPPING OUT BETWEEN 87-90...WHICH IS STILL AT LEAST A FEW DEGREES ABOVE MET GUIDANCE. IF SURFACE DEWPOINTS MANAGE TO MIX DOWN FURTHER THAN CURRENTLY THOUGHT...THEN COULD EASILY SEE PARTS OF THE SOUTHWEST CWA TRY TO MAKE A RUN AT MID 90S BUT WILL KEEP IT BELOW THIS FOR NOW. TUESDAY NIGHT...KEPT IT STORM FREE DESPITE THE LEADING EDGE FORCING FROM THE INCOMING SHORTWAVE/JET STREAK STARTING TO IMPINGE ON WESTERN PORTIONS OF THE REGION. ALTHOUGH THE LOW LEVEL JET WILL REALLY RAMP UP OVER THE CWA DURING THE NIGHT...SPEED CONVERGENCE IS NOT REALLY PRESENT AND MORE IMPORTANTLY...VERY WARM MID LEVEL TEMPS AS EVIDENCED BY 700MB TEMPS CLIMBING INTO AT LEAST THE 12-14C RANGE SHOULD PROVIDE A VERY STOUT CAP EVEN TO ELEVATED PARCELS. EVEN WITH THE APPROACH OF A SURFACE-850MB COLD FRONT AFTER MIDNIGHT ACROSS WESTERN NEB...JUST NOT SEEING THIS CAP BREAKING WITH LARGE SCALE FORCING STILL LIMITED. TEMP WISE...SHOULD BE A SEASONABLY MILD NIGHT AND LEFT LOWS PRETTY MUCH ALONE IN THE LOW-MID 60S. WEDNESDAY DAYTIME...OPTED TO STAY CONSISTENT WITH PREVIOUS FORECAST AND LEAVE OUT STORM MENTION...BUT WILL SAY THAT WOULD NOT BE SURPRISED IF AT LEAST A SLIGHT POP COULD BE ADDED AT SOME POINT. THE MAIN THING HOLDING BACK A LEGITIMATE DAYTIME STORM THREAT IS CONTINUED STRONG CAPPING...WITH THE LATEST 06Z NAM FINALLY FALLING IN LINE WITH THE GFS/ECWMF SOLUTIONS IN KEEPING FAIRLY TOASTY 700MB TEMPS IN PLACE THROUGH THE DAY...DESPITE THE INVASION OF A SURFACE COLD FRONT INTO NORTHWEST PARTS OF THE CWA. EVEN THE LATEST RUN OF THE SREF THUNDER PROBABILITIES HAS BACKED OFF A BIT ON THE FAIRLY SLIM RISK OF PRE-00Z CONVECTIVE INITIATION. ASSUMING THAT IT REMAINS STORM-FREE...THE MAIN ISSUE FOR WEDNESDAY IS A TRICKY HIGH TEMP FORECAST...AS ALTHOUGH THE SOUTHEAST 1/2 OR SO OF THE CWA SHOULD REMAIN FIRMLY IN THE WARM SECTOR...NORTHWEST ZONES COULD SEE AT LEAST WEAK COLD AIR ADVECTION/NORTHEAST WIND. OPTED TO WARM UP MOST AREAS 2-3 DEGREES FROM PREVIOUS FORECAST SIDING WITH SLOWER INVASION OF COOLER AIR...NOW ADVERTISING A RANGE FROM NEAR 80 FAR NORTHWEST TO LOW 90S SOUTHEAST. WEDNESDAY NIGHT...THIS IS CLEARLY THE MOST FAVORED PERIOD FOR POTENTIALLY...REPEATING POTENTIALLY WIDESPREAD THUNDERSTORM ACTIVITY...AS MID LEVEL TEMPS SHOULD BE ABLE TO COOL ENOUGH AT LEAST IN NORTHWEST ZONES TO ALLOW INITIATION. ON THE LARGER SCALE...LEGITIMATE FORCING FINALLY ARRIVES IN THE FORM OF AN OPEN MID LEVEL SHORTWAVE AND THE EXIT REGION OF A 300MB JET STREAK APPROACHING FROM THE CENTRAL ROCKIES. THAT BEING SAID...LATEST MODEL CONSENSUS IS TO REALLY LIMIT STORM DEVELOPMENT ACROSS SOUTHEAST ZONES...WHILE MAINLY TARGETING NORTHWEST ZONES WITH CONVECTION...AND LEAVING CENTRAL PLACES INCLUDING THE TRI CITIES A BIT IN LIMBO. FOR NOW...OPTED TO KEEP POPS SIMILAR TO PREVIOUS FORECAST...RANGING FROM LIKELY 60S IN THE NORTHWEST TO NO STORM MENTION FAR SOUTHEAST...AND A GRADUAL GRADIENT OF SLIGHT CHANCE TO CHANCE POPS IN BETWEEN. THE POTENTIAL IS CERTAINLY THERE FOR A WIDESPREAD FLARE UP OF STORMS...AS THE NAM ADVERTISES CONSIDERABLE CONVERGENCE ACROSS A SHARP 850MB FRONT...WITH A LOW LEVEL JET POTENTIALLY IN EXCESS OF 60KT BLASTING INTO THIS BOUNDARY. WITH ELEVATED INSTABILITY POTENTIALLY INTO THE 1000-2000 J/KG RANGE IN THE EVENING...ALONG WITH DEEP LAYER SHEAR ON THE ORDER OF 50-70KT...A ROUND OF SEVERE STORMS WITH HAIL/WIND IS VERY POSSIBLE...AGAIN MAINLY FAVORING THE LESS-CAPPED NORTHWEST ZONES. CERTAINLY PLENTY OF DETAILS TO IRON OUT OVER THE NEXT FEW DAYS THOUGH. LONG TERM...STARTING 12Z THURSDAY. GUIDANCE CONTINUES TO SUGGEST MID AND UPPER LEVEL JET ENERGY WILL PERSIST OVER THE CENTRAL PLAINS THROUGH MUCH OF THE LONG TERM FORECAST PERIOD. AT THE SURFACE A RIDGE HIGH PRESSURE IS EXPECTED TO DOMINATE THE LOW LEVELS THURSDAY THROUGH MUCH OF FRIDAY...WITH LOW LEVEL RETURN FLOW MATERIALIZING ACROSS THE AREA LATE FRIDAY ONWARD. THE OPERATIONAL GFS AND EC BOTH ADVERTISE MID LEVEL PERTURBATIONS WILL PUSH OVER THE AREA DURING THE DAY THURSDAY...WITH PERHAPS ENOUGH OMEGA AND MOISTURE FOR PRECIPITATION PRODUCTION ACROSS NORTHERN PORTIONS OF THE CWA. THE RIGHT-REAR QUADRANT OF A ~70KT MID LEVEL JET STREAK IS THEN EXPECTED TO PROMOTE ENOUGH OF A DIRECT THERMAL CIRCULATION FOR PRECIPITATION PRODUCTION ACROSS MUCH OF THE CWA THURSDAY NIGHT INTO FRIDAY MORNING. AN OVERALL LACK IN KINEMATIC FORCING IS THEN EXPECTED TO BRING DRY CONDITIONS TO THE AREA DURING THE DAY FRIDAY...WITH THE EMERGENCE OF A ~40KT LOW LEVEL JET BRINGING ANOTHER POSSIBILITY OF PRECIPITATION TO THE AREA FRIDAY NIGHT INTO SATURDAY MORNING. ONE MORE ROUND OF NOCTURNAL PRECIPITATION THEN APPEARS POSSIBLE SATURDAY NIGHT INTO SUNDAY MORNING AS A STRONGER LOW LEVEL JET INFILTRATES THE AREA. LOW LEVEL MOISTURE REMAINS LESS THAN IMPRESSIVE THROUGH FRIDAY AS SURFACE RIDGING REMAINS ENTRENCHED ACROSS THE AREA AND AS A RESULT...INSTABILITY SUFFERS GREATLY. CONTEMPLATED TAKEN THUNDER OUT OF THE FORECAST ALTOGETHER THURSDAY AND THURSDAY NIGHT BUT WITH THE OPERATIONAL GFS AND EC BOTH SUGGESTING MAYBE AROUND 100J/KG DEEP LAYER MUCAPE VALUES...WENT AHEAD WITH ISOLATED THUNDER MENTION FOR THAT TIME BEING. LOW LEVEL MOISTURE FLUX INTO THE AREA VIA LOW LEVEL RETURN FLOW SHOULD ALLOW FOR INCREASING INSTABILITY VALUES HEADING INTO THE WEEKEND...WITH 1000-2000J/KG DEEP LAYER MUCAPE VALUES BEING ADVERTISED BY THE OPERATIONAL GFS AND EC. NEAR TO SLIGHTLY ABOVE-NORMAL TEMPERATURES ARE STILL EXPECTED THURSDAY AS SURFACE RIDGING REMAINS OVER THE AREA. LOW LEVEL RETURN FLOW WILL THEN PROMOTE A WARMING TREND...WITH TEMPERATURES CLIMBING TO LEVELS WELL ABOVE-NORMAL FOR THIS TIME OF YEAR ACROSS OUR SOUTH ON FRIDAY...AND ACROSS THE ENTIRE CWA SATURDAY ONWARD. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1034 AM CDT MON MAY 21 2012 .UPDATE...LIGHT SHOWERS HAVE BEGUN TO DISSIPATE ACROSS THE FORECAST AREA. && .PREV DISCUSSION... /ISSUED 550 AM CDT MON MAY 21 2012/ AVIATION...12Z KGRI TAF. VFR CONDITIONS TO CONTINUE AT THE TERMINAL THROUGH THE NEXT 24 HOURS. MID TO HIGH LEVEL CLOUDS WILL BE NOTED TODAY...BUT NOTHING BELOW 10000FT AGL. SURFACE WINDS WILL REMAIN FROM THE SOUTH...INCREASING TO AROUND 15KTS LATER TODAY. VISIBILITY RESTRICTIONS ARE NOT ANTICIPATED THROUGH THE NEXT 24 HOURS. PREV DISCUSSION... /ISSUED 447 AM CDT MON MAY 21 2012/ SHORT TERM...ALTHOUGH THE MAJORITY OF THE NEXT 72 HOURS SHOULD REMAIN DRY...WILL HAVE TO DEAL WITH AT LEAST SOME SPRINKLES/BRIEF SHOWERS THIS MORNING MAINLY IN THE NORTH...AND EVENTUALLY WHAT SHOULD BE A MORE WIDESPREAD THUNDERSTORM RISK IN SOME AREAS WEDNESDAY EVENING/NIGHT. ALSO OF CONCERN IS POSSIBLE ADVISORY-LEVEL SOUTHERLY WIND ON TUESDAY. 08Z OBJECTIVE SURFACE ANALYSIS PLACES A BROAD 1025MB RIDGE AXIS ACROSS EASTERN NEB...PROVIDING NEAR CALM TO VERY LIGHT EAST/SOUTHEAST BREEZES TO THE CWA. ALTHOUGH MID LEVEL CLOUDS WILL BE ON THE INCREASE THROUGH SUNRISE...MAINLY CLEAR SKIES THUS FAR TONIGHT HAVE RESULTED IN AN EFFICIENT COOL DOWN INTO THE MID/UPPER 40S IN MOST AREAS. SPEAKING OF THOSE INCOMING MID CLOUDS AND INCORPORATING RADAR TRENDS...SURE ENOUGH AND AS SUSPECTED HERE 24 HOURS AGO...A NARROW NORTH-SOUTH BAND OF MID-LEVEL THETA-E ADVECTION EVIDENT AT 700MB HAS SPARKED AN AREA OF AT THE VERY LEAST SCATTERED SPRINKLES/LIGHT SHOWERS AND EVEN A FEW WEAK THUNDERSTORMS THAT HAVE SO FAR LARGELY STAYED JUST OUTSIDE THE CWA ALONG AN AXIS FROM NEAR VALENTINE TO NORTH PLATTE. WATER VAPOR IMAGERY CONFIRMS BROAD NORTHWEST FLOW ALOFT OVER THE CENTRAL PLAINS...AS THE REGION LIES ALONG THE NORTHEAST PERIPHERY OF A BUILDING MID/UPPER RIDGE AXIS EXTENDING ALL THE WAY BACK TO THE PACIFIC NORTHWEST...WHERE THE NEXT LARGER SCALE SHORTWAVE/UPPER JET STREAK OF INTEREST IS ARRIVING ON THE SCENE. THE IMMEDIATE ISSUE THROUGH AT LEAST THE NEXT 4-6 HOURS IS THE EVOLUTION OF DEVELOPING SHOWER ACTIVITY THIS MORNING. THIS NARROW CORRIDOR OF HIGH BASED CONVECTION IS CLASSICALLY LOCATED ALONG THE LEADING EDGE OF 700MB THETA-E ADVECTION...AND IMMEDIATELY EAST OF THE CORE OF THE 850MB LOW LEVEL JET CURRENTLY CENTERED FROM FAR WESTERN KS INTO WESTERN NEB. AS USUAL...DETERMINISTIC MODELS SUCH AS NAM/GFS/ECMWF ARE STRUGGLING TO FULLY CAPTURE THIS ACTIVITY IN THEIR QPF FIELDS...WHILE HIGHER RESOLUTION SHORT TERM MODELS SUCH AS THE HRRR AND 0Z 4KM WRF-NMM ARE PROVING BETTER. OBJECTIVE RUC ANALYSIS AND 06Z NAM CONFIRM THAT ELEVATED MUCAPE VALUES MAINLY IN THE 800-650MB LAYER ARE ONLY RUNNING A MEAGER 100 J/KG OR SO. FOLLOWING THE 06Z NAM...THIS BAND OF MID LEVEL THETA-E ADVECTION SHOULD CONTINUE TO STEADILY TRACK EAST MAINLY ACROSS THE NORTHERN 1/2 OF NEB THROUGH THE MORNING HOURS...AT LEAST PUTTING PARTS OF THE NORTHERN CWA IN LINE FOR NUISANCE AND UNFORTUNATELY PREVIOUSLY UN-ADVERTISED PRECIPITATION. HAVE DEBATED BETWEEN GOING WITH A MEASURABLE POP/SHOWER AND MAYBE EVEN AN ISOLATED THUNDERSTORM MENTION...BUT AT LEAST TO START OUT WITH THIS MORNING WILL TRY...REPEAT TRY...TO GET AWAY WITH ONLY SCATTERED SPRINKLE MENTION ALONG AND NORTH OF I-80 WITH EXPECTATION THAT MEASURABLE PRECIP SHOULD NOT BE OVERLY WIDESPREAD. STAY TUNED FOR POSSIBLE UPDATES HOWEVER AS RADAR TRENDS EVOLVE. OBVIOUSLY EVEN IF ANY ROGUE LIGHTNING STRIKES TO MANAGE TO SNEAK IN...WOULD NOT ANTICIPATE ANYTHING CLOSE TO BEING SEVERE...WITH EVEN SMALL HAIL HARD TO COME BY. WITH EXPECTATION OF THIS BEING A MORNING-ONLY ISSUE...HAVE NO PRECIP MENTION WITHIN THE CWA BEYOND 17Z...AS THE AFTERNOON HOURS WILL FEATURE THE PRIMARY LOWER LEVEL INSTABILITY AXIS SETTING UP WEST OF THE CWA ALONG AN AXIS FROM FAR WESTERN KS NORTHWARD INTO WESTERN NEB. MEANWHILE...SOUTH/SOUTHEAST WIND WILL BE ON THE INCREASE AS THE DAY WEARS ON...AS THE SURFACE RIDGE AXIS DEPARTS EAST INTO IA/MO. AS A RESULT...THE AFTERNOON HOURS WILL FEATURE SUSTAINED SPEEDS RANGING FROM NEAR 15 MPH IN FAR EASTERN COUNTIES...TO 20-25 MPH IN SOME WESTERN AREAS ALONG WITH GUSTS TO AROUND 30 MPH. TEMP WISE TODAY...CHANGED HIGHS LITTLE FROM PREVIOUS FORECAST...AND FOLLOWED 0Z NAM RAW TEMPS QUITE CLOSELY. ALTHOUGH PASSING MID LEVEL CLOUDS THIS MORNING COULD PUT A TEMPORARY DELAY ON THE DIURNAL CLIMB...HAVE AIMED MOST OF THE CWA INTO THE 77-81 RANGE FOR EVENTUAL HIGHS. THIS EVENING/TONIGHT...ANY STORMS THAT MANAGE TO FORM OUT IN WESTERN NEB LATE THIS AFTERNOON WITHIN THE INSTABILITY AXIS SHOULD STEADILY FADE AWAY LONG BEFORE MAKING IT INTO THE CWA. THAT BEING SAID...HAVE OPTED TO DISREGARD THE 00Z GFS SOLUTION WHICH BREAKS OUT WIDESPREAD QPF TONIGHT MAINLY IN SOUTHWEST/CENTRAL KS...BUT ALSO BRUSHING UP INTO THE KS ZONES OF OUR CWA. WITH THE NAM/ECMWF AND 4KM WRF-NMM ESSENTIALLY SHOWING NOTHING OF THIS NATURE...IT JUST SEEMS TOO MUCH AN OUTLIER AND HAVE KEPT THE ENTIRE CWA PRECIP-FREE TONIGHT. ALOFT...THE HEART OF THE MID/UPPER RIDGE AXIS WILL SET UP OVER THE CENTRAL PLAINS TONIGHT...AS THE UPSTREAM TROUGH/JET STREAK START CROSSING THE NORTHERN ROCKIES. AT THE SURFACE...STEADY SOUTHERLY BREEZES SHOULD HELP HOLD TEMPS UP ABOUT 10 DEGREES WARMER THAN THOSE THIS MORNING...AND HAVE MOST OF THE CWA IN THE 55-58 RANGE FOR LOWS...WHICH IS VERY SLIGHTLY WARMER THAN PREVIOUS FORECAST. TUESDAY IS STILL SHAPING UP TO BE THE WARMEST DAY OF THE WEEK...WITH PLENTY OF SOUTHERLY WIND TO GO WITH IT. STARTING WITH STORM CHANCES...HAVE KEPT IT STORM FREE THROUGH THE DAY...AS EVEN THOUGH DEWPOINTS WILL BE IN THE INCREASE INTO THE 50S IN MOST AREAS WITH A CORRESPONDING INCREASE IN LOW LEVEL INSTABILITY...MID LEVEL TEMPS WILL ALSO BE ON THE INCREASE...WITH NAM SOUNDINGS CONFIRMING A DECENT CAPPING INVERSION. BY LATE AFTERNOON...THE NAM/GFS/ECMWF ARE IN GENERAL AGREEMENT SETTING UP A 990-994MB LOW IN FAR WESTERN NEBRASKA...WITH PRESSURE FALLS DURING THE DAY SETTING UP QUITE A HEALTHY EAST-WEST SURFACE PRESSURE GRADIENT DURING THE DAY. THIS GRADIENT...IN TANDEM WITH SHOULD BE PLENTY OF SUN AND MIXING TO AT LEAST THE 800MB LEVEL SHOULD HELP CRANK UP THE SOUTHERLY WIND. TAKING A CONSENSUS OF 00Z MET/MAV GUIDANCE FOR SPEEDS...HAVE MOST OF THE CWA CURRENTLY TOPPING OUT IN THE 25-30 MPH RANGE FOR SUSTAINED SPEEDS...WHICH IF IT WERE TO HOLD WOULD GENERALLY FALL JUST SHORT OF WIND ADVISORY CRITERIA. HOWEVER...COULD EASILY FORESEE AT LEAST WESTERN PORTIONS OF THE CWA ENDING UP WITH HIGHER SPEEDS OVER 30 MPH...AND ALTHOUGH WILL FOREGO ANY HEADLINE ISSUANCE STILL BEING 3 PERIODS OUT...WILL CONTINUE TO HIGHLIGHT AT LEAST NEAR-ADVISORY SPEEDS IN THE HWO. CERTAINLY GUSTS TO AROUND 40 MPH SHOULD BE COMMON NO MATTER WHAT DURING THE AFTERNOON. TEMP-WISE...AGAIN LEANED HEAVILY ON RAW 0Z NAM NUMBERS...WHICH RESULTED IN LITTLE CHANGE FROM PREVIOUS ACROSS EASTERN ZONES...BUT ACTUALLY A SLIGHT LOWERING IN WESTERN AREAS. THIS RESULTS IN MOST AREAS TOPPING OUT BETWEEN 87-90...WHICH IS STILL AT LEAST A FEW DEGREES ABOVE MET GUIDANCE. IF SURFACE DEWPOINTS MANAGE TO MIX DOWN FURTHER THAN CURRENTLY THOUGHT...THEN COULD EASILY SEE PARTS OF THE SOUTHWEST CWA TRY TO MAKE A RUN AT MID 90S BUT WILL KEEP IT BELOW THIS FOR NOW. TUESDAY NIGHT...KEPT IT STORM FREE DESPITE THE LEADING EDGE FORCING FROM THE INCOMING SHORTWAVE/JET STREAK STARTING TO IMPINGE ON WESTERN PORTIONS OF THE REGION. ALTHOUGH THE LOW LEVEL JET WILL REALLY RAMP UP OVER THE CWA DURING THE NIGHT...SPEED CONVERGENCE IS NOT REALLY PRESENT AND MORE IMPORTANTLY...VERY WARM MID LEVEL TEMPS AS EVIDENCED BY 700MB TEMPS CLIMBING INTO AT LEAST THE 12-14C RANGE SHOULD PROVIDE A VERY STOUT CAP EVEN TO ELEVATED PARCELS. EVEN WITH THE APPROACH OF A SURFACE-850MB COLD FRONT AFTER MIDNIGHT ACROSS WESTERN NEB...JUST NOT SEEING THIS CAP BREAKING WITH LARGE SCALE FORCING STILL LIMITED. TEMP WISE...SHOULD BE A SEASONABLY MILD NIGHT AND LEFT LOWS PRETTY MUCH ALONE IN THE LOW-MID 60S. WEDNESDAY DAYTIME...OPTED TO STAY CONSISTENT WITH PREVIOUS FORECAST AND LEAVE OUT STORM MENTION...BUT WILL SAY THAT WOULD NOT BE SURPRISED IF AT LEAST A SLIGHT POP COULD BE ADDED AT SOME POINT. THE MAIN THING HOLDING BACK A LEGITIMATE DAYTIME STORM THREAT IS CONTINUED STRONG CAPPING...WITH THE LATEST 06Z NAM FINALLY FALLING IN LINE WITH THE GFS/ECWMF SOLUTIONS IN KEEPING FAIRLY TOASTY 700MB TEMPS IN PLACE THROUGH THE DAY...DESPITE THE INVASION OF A SURFACE COLD FRONT INTO NORTHWEST PARTS OF THE CWA. EVEN THE LATEST RUN OF THE SREF THUNDER PROBABILITIES HAS BACKED OFF A BIT ON THE FAIRLY SLIM RISK OF PRE-00Z CONVECTIVE INITIATION. ASSUMING THAT IT REMAINS STORM-FREE...THE MAIN ISSUE FOR WEDNESDAY IS A TRICKY HIGH TEMP FORECAST...AS ALTHOUGH THE SOUTHEAST 1/2 OR SO OF THE CWA SHOULD REMAIN FIRMLY IN THE WARM SECTOR...NORTHWEST ZONES COULD SEE AT LEAST WEAK COLD AIR ADVECTION/NORTHEAST WIND. OPTED TO WARM UP MOST AREAS 2-3 DEGREES FROM PREVIOUS FORECAST SIDING WITH SLOWER INVASION OF COOLER AIR...NOW ADVERTISING A RANGE FROM NEAR 80 FAR NORTHWEST TO LOW 90S SOUTHEAST. WEDNESDAY NIGHT...THIS IS CLEARLY THE MOST FAVORED PERIOD FOR POTENTIALLY...REPEATING POTENTIALLY WIDESPREAD THUNDERSTORM ACTIVITY...AS MID LEVEL TEMPS SHOULD BE ABLE TO COOL ENOUGH AT LEAST IN NORTHWEST ZONES TO ALLOW INITIATION. ON THE LARGER SCALE...LEGITIMATE FORCING FINALLY ARRIVES IN THE FORM OF AN OPEN MID LEVEL SHORTWAVE AND THE EXIT REGION OF A 300MB JET STREAK APPROACHING FROM THE CENTRAL ROCKIES. THAT BEING SAID...LATEST MODEL CONSENSUS IS TO REALLY LIMIT STORM DEVELOPMENT ACROSS SOUTHEAST ZONES...WHILE MAINLY TARGETING NORTHWEST ZONES WITH CONVECTION...AND LEAVING CENTRAL PLACES INCLUDING THE TRI CITIES A BIT IN LIMBO. FOR NOW...OPTED TO KEEP POPS SIMILAR TO PREVIOUS FORECAST...RANGING FROM LIKELY 60S IN THE NORTHWEST TO NO STORM MENTION FAR SOUTHEAST...AND A GRADUAL GRADIENT OF SLIGHT CHANCE TO CHANCE POPS IN BETWEEN. THE POTENTIAL IS CERTAINLY THERE FOR A WIDESPREAD FLARE UP OF STORMS...AS THE NAM ADVERTISES CONSIDERABLE CONVERGENCE ACROSS A SHARP 850MB FRONT...WITH A LOW LEVEL JET POTENTIALLY IN EXCESS OF 60KT BLASTING INTO THIS BOUNDARY. WITH ELEVATED INSTABILITY POTENTIALLY INTO THE 1000-2000 J/KG RANGE IN THE EVENING...ALONG WITH DEEP LAYER SHEAR ON THE ORDER OF 50-70KT...A ROUND OF SEVERE STORMS WITH HAIL/WIND IS VERY POSSIBLE...AGAIN MAINLY FAVORING THE LESS-CAPPED NORTHWEST ZONES. CERTAINLY PLENTY OF DETAILS TO IRON OUT OVER THE NEXT FEW DAYS THOUGH. LONG TERM...STARTING 12Z THURSDAY. GUIDANCE CONTINUES TO SUGGEST MID AND UPPER LEVEL JET ENERGY WILL PERSIST OVER THE CENTRAL PLAINS THROUGH MUCH OF THE LONG TERM FORECAST PERIOD. AT THE SURFACE A RIDGE HIGH PRESSURE IS EXPECTED TO DOMINATE THE LOW LEVELS THURSDAY THROUGH MUCH OF FRIDAY...WITH LOW LEVEL RETURN FLOW MATERIALIZING ACROSS THE AREA LATE FRIDAY ONWARD. THE OPERATIONAL GFS AND EC BOTH ADVERTISE MID LEVEL PERTURBATIONS WILL PUSH OVER THE AREA DURING THE DAY THURSDAY...WITH PERHAPS ENOUGH OMEGA AND MOISTURE FOR PRECIPITATION PRODUCTION ACROSS NORTHERN PORTIONS OF THE CWA. THE RIGHT-REAR QUADRANT OF A ~70KT MID LEVEL JET STREAK IS THEN EXPECTED TO PROMOTE ENOUGH OF A DIRECT THERMAL CIRCULATION FOR PRECIPITATION PRODUCTION ACROSS MUCH OF THE CWA THURSDAY NIGHT INTO FRIDAY MORNING. AN OVERALL LACK IN KINEMATIC FORCING IS THEN EXPECTED TO BRING DRY CONDITIONS TO THE AREA DURING THE DAY FRIDAY...WITH THE EMERGENCE OF A ~40KT LOW LEVEL JET BRINGING ANOTHER POSSIBILITY OF PRECIPITATION TO THE AREA FRIDAY NIGHT INTO SATURDAY MORNING. ONE MORE ROUND OF NOCTURNAL PRECIPITATION THEN APPEARS POSSIBLE SATURDAY NIGHT INTO SUNDAY MORNING AS A STRONGER LOW LEVEL JET INFILTRATES THE AREA. LOW LEVEL MOISTURE REMAINS LESS THAN IMPRESSIVE THROUGH FRIDAY AS SURFACE RIDGING REMAINS ENTRENCHED ACROSS THE AREA AND AS A RESULT...INSTABILITY SUFFERS GREATLY. CONTEMPLATED TAKEN THUNDER OUT OF THE FORECAST ALTOGETHER THURSDAY AND THURSDAY NIGHT BUT WITH THE OPERATIONAL GFS AND EC BOTH SUGGESTING MAYBE AROUND 100J/KG DEEP LAYER MUCAPE VALUES...WENT AHEAD WITH ISOLATED THUNDER MENTION FOR THAT TIME BEING. LOW LEVEL MOISTURE FLUX INTO THE AREA VIA LOW LEVEL RETURN FLOW SHOULD ALLOW FOR INCREASING INSTABILITY VALUES HEADING INTO THE WEEKEND...WITH 1000-2000J/KG DEEP LAYER MUCAPE VALUES BEING ADVERTISED BY THE OPERATIONAL GFS AND EC. NEAR TO SLIGHTLY ABOVE-NORMAL TEMPERATURES ARE STILL EXPECTED THURSDAY AS SURFACE RIDGING REMAINS OVER THE AREA. LOW LEVEL RETURN FLOW WILL THEN PROMOTE A WARMING TREND...WITH TEMPERATURES CLIMBING TO LEVELS WELL ABOVE-NORMAL FOR THIS TIME OF YEAR ACROSS OUR SOUTH ON FRIDAY...AND ACROSS THE ENTIRE CWA SATURDAY ONWARD. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
550 AM CDT MON MAY 21 2012 .AVIATION...12Z KGRI TAF. VFR CONDITIONS TO CONTINUE AT THE TERMINAL THROUGH THE NEXT 24 HOURS. MID TO HIGH LEVEL CLOUDS WILL BE NOTED TODAY...BUT NOTHING BELOW 10000FT AGL. SURFACE WINDS WILL REMAIN FROM THE SOUTH...INCREASING TO AROUND 15KTS LATER TODAY. VISIBILITY RESTRICTIONS ARE NOT ANTICIPATED THROUGH THE NEXT 24 HOURS. && .PREV DISCUSSION... /ISSUED 447 AM CDT MON MAY 21 2012/ SHORT TERM...ALTHOUGH THE MAJORITY OF THE NEXT 72 HOURS SHOULD REMAIN DRY...WILL HAVE TO DEAL WITH AT LEAST SOME SPRINKLES/BRIEF SHOWERS THIS MORNING MAINLY IN THE NORTH...AND EVENTUALLY WHAT SHOULD BE A MORE WIDESPREAD THUNDERSTORM RISK IN SOME AREAS WEDNESDAY EVENING/NIGHT. ALSO OF CONCERN IS POSSIBLE ADVISORY-LEVEL SOUTHERLY WIND ON TUESDAY. 08Z OBJECTIVE SURFACE ANALYSIS PLACES A BROAD 1025MB RIDGE AXIS ACROSS EASTERN NEB...PROVIDING NEAR CALM TO VERY LIGHT EAST/SOUTHEAST BREEZES TO THE CWA. ALTHOUGH MID LEVEL CLOUDS WILL BE ON THE INCREASE THROUGH SUNRISE...MAINLY CLEAR SKIES THUS FAR TONIGHT HAVE RESULTED IN AN EFFICIENT COOL DOWN INTO THE MID/UPPER 40S IN MOST AREAS. SPEAKING OF THOSE INCOMING MID CLOUDS AND INCORPORATING RADAR TRENDS...SURE ENOUGH AND AS SUSPECTED HERE 24 HOURS AGO...A NARROW NORTH-SOUTH BAND OF MID-LEVEL THETA-E ADVECTION EVIDENT AT 700MB HAS SPARKED AN AREA OF AT THE VERY LEAST SCATTERED SPRINKLES/LIGHT SHOWERS AND EVEN A FEW WEAK THUNDERSTORMS THAT HAVE SO FAR LARGELY STAYED JUST OUTSIDE THE CWA ALONG AN AXIS FROM NEAR VALENTINE TO NORTH PLATTE. WATER VAPOR IMAGERY CONFIRMS BROAD NORTHWEST FLOW ALOFT OVER THE CENTRAL PLAINS...AS THE REGION LIES ALONG THE NORTHEAST PERIPHERY OF A BUILDING MID/UPPER RIDGE AXIS EXTENDING ALL THE WAY BACK TO THE PACIFIC NORTHWEST...WHERE THE NEXT LARGER SCALE SHORTWAVE/UPPER JET STREAK OF INTEREST IS ARRIVING ON THE SCENE. THE IMMEDIATE ISSUE THROUGH AT LEAST THE NEXT 4-6 HOURS IS THE EVOLUTION OF DEVELOPING SHOWER ACTIVITY THIS MORNING. THIS NARROW CORRIDOR OF HIGH BASED CONVECTION IS CLASSICALLY LOCATED ALONG THE LEADING EDGE OF 700MB THETA-E ADVECTION...AND IMMEDIATELY EAST OF THE CORE OF THE 850MB LOW LEVEL JET CURRENTLY CENTERED FROM FAR WESTERN KS INTO WESTERN NEB. AS USUAL...DETERMINISTIC MODELS SUCH AS NAM/GFS/ECMWF ARE STRUGGLING TO FULLY CAPTURE THIS ACTIVITY IN THEIR QPF FIELDS...WHILE HIGHER RESOLUTION SHORT TERM MODELS SUCH AS THE HRRR AND 0Z 4KM WRF-NMM ARE PROVING BETTER. OBJECTIVE RUC ANALYSIS AND 06Z NAM CONFIRM THAT ELEVATED MUCAPE VALUES MAINLY IN THE 800-650MB LAYER ARE ONLY RUNNING A MEAGER 100 J/KG OR SO. FOLLOWING THE 06Z NAM...THIS BAND OF MID LEVEL THETA-E ADVECTION SHOULD CONTINUE TO STEADILY TRACK EAST MAINLY ACROSS THE NORTHERN 1/2 OF NEB THROUGH THE MORNING HOURS...AT LEAST PUTTING PARTS OF THE NORTHERN CWA IN LINE FOR NUISANCE AND UNFORTUNATELY PREVIOUSLY UN-ADVERTISED PRECIPITATION. HAVE DEBATED BETWEEN GOING WITH A MEASURABLE POP/SHOWER AND MAYBE EVEN AN ISOLATED THUNDERSTORM MENTION...BUT AT LEAST TO START OUT WITH THIS MORNING WILL TRY...REPEAT TRY...TO GET AWAY WITH ONLY SCATTERED SPRINKLE MENTION ALONG AND NORTH OF I-80 WITH EXPECTATION THAT MEASURABLE PRECIP SHOULD NOT BE OVERLY WIDESPREAD. STAY TUNED FOR POSSIBLE UPDATES HOWEVER AS RADAR TRENDS EVOLVE. OBVIOUSLY EVEN IF ANY ROGUE LIGHTNING STRIKES TO MANAGE TO SNEAK IN...WOULD NOT ANTICIPATE ANYTHING CLOSE TO BEING SEVERE...WITH EVEN SMALL HAIL HARD TO COME BY. WITH EXPECTATION OF THIS BEING A MORNING-ONLY ISSUE...HAVE NO PRECIP MENTION WITHIN THE CWA BEYOND 17Z...AS THE AFTERNOON HOURS WILL FEATURE THE PRIMARY LOWER LEVEL INSTABILITY AXIS SETTING UP WEST OF THE CWA ALONG AN AXIS FROM FAR WESTERN KS NORTHWARD INTO WESTERN NEB. MEANWHILE...SOUTH/SOUTHEAST WIND WILL BE ON THE INCREASE AS THE DAY WEARS ON...AS THE SURFACE RIDGE AXIS DEPARTS EAST INTO IA/MO. AS A RESULT...THE AFTERNOON HOURS WILL FEATURE SUSTAINED SPEEDS RANGING FROM NEAR 15 MPH IN FAR EASTERN COUNTIES...TO 20-25 MPH IN SOME WESTERN AREAS ALONG WITH GUSTS TO AROUND 30 MPH. TEMP WISE TODAY...CHANGED HIGHS LITTLE FROM PREVIOUS FORECAST...AND FOLLOWED 0Z NAM RAW TEMPS QUITE CLOSELY. ALTHOUGH PASSING MID LEVEL CLOUDS THIS MORNING COULD PUT A TEMPORARY DELAY ON THE DIURNAL CLIMB...HAVE AIMED MOST OF THE CWA INTO THE 77-81 RANGE FOR EVENTUAL HIGHS. THIS EVENING/TONIGHT...ANY STORMS THAT MANAGE TO FORM OUT IN WESTERN NEB LATE THIS AFTERNOON WITHIN THE INSTABILITY AXIS SHOULD STEADILY FADE AWAY LONG BEFORE MAKING IT INTO THE CWA. THAT BEING SAID...HAVE OPTED TO DISREGARD THE 00Z GFS SOLUTION WHICH BREAKS OUT WIDESPREAD QPF TONIGHT MAINLY IN SOUTHWEST/CENTRAL KS...BUT ALSO BRUSHING UP INTO THE KS ZONES OF OUR CWA. WITH THE NAM/ECMWF AND 4KM WRF-NMM ESSENTIALLY SHOWING NOTHING OF THIS NATURE...IT JUST SEEMS TOO MUCH AN OUTLIER AND HAVE KEPT THE ENTIRE CWA PRECIP-FREE TONIGHT. ALOFT...THE HEART OF THE MID/UPPER RIDGE AXIS WILL SET UP OVER THE CENTRAL PLAINS TONIGHT...AS THE UPSTREAM TROUGH/JET STREAK START CROSSING THE NORTHERN ROCKIES. AT THE SURFACE...STEADY SOUTHERLY BREEZES SHOULD HELP HOLD TEMPS UP ABOUT 10 DEGREES WARMER THAN THOSE THIS MORNING...AND HAVE MOST OF THE CWA IN THE 55-58 RANGE FOR LOWS...WHICH IS VERY SLIGHTLY WARMER THAN PREVIOUS FORECAST. TUESDAY IS STILL SHAPING UP TO BE THE WARMEST DAY OF THE WEEK...WITH PLENTY OF SOUTHERLY WIND TO GO WITH IT. STARTING WITH STORM CHANCES...HAVE KEPT IT STORM FREE THROUGH THE DAY...AS EVEN THOUGH DEWPOINTS WILL BE IN THE INCREASE INTO THE 50S IN MOST AREAS WITH A CORRESPONDING INCREASE IN LOW LEVEL INSTABILITY...MID LEVEL TEMPS WILL ALSO BE ON THE INCREASE...WITH NAM SOUNDINGS CONFIRMING A DECENT CAPPING INVERSION. BY LATE AFTERNOON...THE NAM/GFS/ECMWF ARE IN GENERAL AGREEMENT SETTING UP A 990-994MB LOW IN FAR WESTERN NEBRASKA...WITH PRESSURE FALLS DURING THE DAY SETTING UP QUITE A HEALTHY EAST-WEST SURFACE PRESSURE GRADIENT DURING THE DAY. THIS GRADIENT...IN TANDEM WITH SHOULD BE PLENTY OF SUN AND MIXING TO AT LEAST THE 800MB LEVEL SHOULD HELP CRANK UP THE SOUTHERLY WIND. TAKING A CONSENSUS OF 00Z MET/MAV GUIDANCE FOR SPEEDS...HAVE MOST OF THE CWA CURRENTLY TOPPING OUT IN THE 25-30 MPH RANGE FOR SUSTAINED SPEEDS...WHICH IF IT WERE TO HOLD WOULD GENERALLY FALL JUST SHORT OF WIND ADVISORY CRITERIA. HOWEVER...COULD EASILY FORESEE AT LEAST WESTERN PORTIONS OF THE CWA ENDING UP WITH HIGHER SPEEDS OVER 30 MPH...AND ALTHOUGH WILL FOREGO ANY HEADLINE ISSUANCE STILL BEING 3 PERIODS OUT...WILL CONTINUE TO HIGHLIGHT AT LEAST NEAR-ADVISORY SPEEDS IN THE HWO. CERTAINLY GUSTS TO AROUND 40 MPH SHOULD BE COMMON NO MATTER WHAT DURING THE AFTERNOON. TEMP-WISE...AGAIN LEANED HEAVILY ON RAW 0Z NAM NUMBERS...WHICH RESULTED IN LITTLE CHANGE FROM PREVIOUS ACROSS EASTERN ZONES...BUT ACTUALLY A SLIGHT LOWERING IN WESTERN AREAS. THIS RESULTS IN MOST AREAS TOPPING OUT BETWEEN 87-90...WHICH IS STILL AT LEAST A FEW DEGREES ABOVE MET GUIDANCE. IF SURFACE DEWPOINTS MANAGE TO MIX DOWN FURTHER THAN CURRENTLY THOUGHT...THEN COULD EASILY SEE PARTS OF THE SOUTHWEST CWA TRY TO MAKE A RUN AT MID 90S BUT WILL KEEP IT BELOW THIS FOR NOW. TUESDAY NIGHT...KEPT IT STORM FREE DESPITE THE LEADING EDGE FORCING FROM THE INCOMING SHORTWAVE/JET STREAK STARTING TO IMPINGE ON WESTERN PORTIONS OF THE REGION. ALTHOUGH THE LOW LEVEL JET WILL REALLY RAMP UP OVER THE CWA DURING THE NIGHT...SPEED CONVERGENCE IS NOT REALLY PRESENT AND MORE IMPORTANTLY...VERY WARM MID LEVEL TEMPS AS EVIDENCED BY 700MB TEMPS CLIMBING INTO AT LEAST THE 12-14C RANGE SHOULD PROVIDE A VERY STOUT CAP EVEN TO ELEVATED PARCELS. EVEN WITH THE APPROACH OF A SURFACE-850MB COLD FRONT AFTER MIDNIGHT ACROSS WESTERN NEB...JUST NOT SEEING THIS CAP BREAKING WITH LARGE SCALE FORCING STILL LIMITED. TEMP WISE...SHOULD BE A SEASONABLY MILD NIGHT AND LEFT LOWS PRETTY MUCH ALONE IN THE LOW-MID 60S. WEDNESDAY DAYTIME...OPTED TO STAY CONSISTENT WITH PREVIOUS FORECAST AND LEAVE OUT STORM MENTION...BUT WILL SAY THAT WOULD NOT BE SURPRISED IF AT LEAST A SLIGHT POP COULD BE ADDED AT SOME POINT. THE MAIN THING HOLDING BACK A LEGITIMATE DAYTIME STORM THREAT IS CONTINUED STRONG CAPPING...WITH THE LATEST 06Z NAM FINALLY FALLING IN LINE WITH THE GFS/ECWMF SOLUTIONS IN KEEPING FAIRLY TOASTY 700MB TEMPS IN PLACE THROUGH THE DAY...DESPITE THE INVASION OF A SURFACE COLD FRONT INTO NORTHWEST PARTS OF THE CWA. EVEN THE LATEST RUN OF THE SREF THUNDER PROBABILITIES HAS BACKED OFF A BIT ON THE FAIRLY SLIM RISK OF PRE-00Z CONVECTIVE INITIATION. ASSUMING THAT IT REMAINS STORM-FREE...THE MAIN ISSUE FOR WEDNESDAY IS A TRICKY HIGH TEMP FORECAST...AS ALTHOUGH THE SOUTHEAST 1/2 OR SO OF THE CWA SHOULD REMAIN FIRMLY IN THE WARM SECTOR...NORTHWEST ZONES COULD SEE AT LEAST WEAK COLD AIR ADVECTION/NORTHEAST WIND. OPTED TO WARM UP MOST AREAS 2-3 DEGREES FROM PREVIOUS FORECAST SIDING WITH SLOWER INVASION OF COOLER AIR...NOW ADVERTISING A RANGE FROM NEAR 80 FAR NORTHWEST TO LOW 90S SOUTHEAST. WEDNESDAY NIGHT...THIS IS CLEARLY THE MOST FAVORED PERIOD FOR POTENTIALLY...REPEATING POTENTIALLY WIDESPREAD THUNDERSTORM ACTIVITY...AS MID LEVEL TEMPS SHOULD BE ABLE TO COOL ENOUGH AT LEAST IN NORTHWEST ZONES TO ALLOW INITIATION. ON THE LARGER SCALE...LEGITIMATE FORCING FINALLY ARRIVES IN THE FORM OF AN OPEN MID LEVEL SHORTWAVE AND THE EXIT REGION OF A 300MB JET STREAK APPROACHING FROM THE CENTRAL ROCKIES. THAT BEING SAID...LATEST MODEL CONSENSUS IS TO REALLY LIMIT STORM DEVELOPMENT ACROSS SOUTHEAST ZONES...WHILE MAINLY TARGETING NORTHWEST ZONES WITH CONVECTION...AND LEAVING CENTRAL PLACES INCLUDING THE TRI CITIES A BIT IN LIMBO. FOR NOW...OPTED TO KEEP POPS SIMILAR TO PREVIOUS FORECAST...RANGING FROM LIKELY 60S IN THE NORTHWEST TO NO STORM MENTION FAR SOUTHEAST...AND A GRADUAL GRADIENT OF SLIGHT CHANCE TO CHANCE POPS IN BETWEEN. THE POTENTIAL IS CERTAINLY THERE FOR A WIDESPREAD FLARE UP OF STORMS...AS THE NAM ADVERTISES CONSIDERABLE CONVERGENCE ACROSS A SHARP 850MB FRONT...WITH A LOW LEVEL JET POTENTIALLY IN EXCESS OF 60KT BLASTING INTO THIS BOUNDARY. WITH ELEVATED INSTABILITY POTENTIALLY INTO THE 1000-2000 J/KG RANGE IN THE EVENING...ALONG WITH DEEP LAYER SHEAR ON THE ORDER OF 50-70KT...A ROUND OF SEVERE STORMS WITH HAIL/WIND IS VERY POSSIBLE...AGAIN MAINLY FAVORING THE LESS-CAPPED NORTHWEST ZONES. CERTAINLY PLENTY OF DETAILS TO IRON OUT OVER THE NEXT FEW DAYS THOUGH. LONG TERM...STARTING 12Z THURSDAY. GUIDANCE CONTINUES TO SUGGEST MID AND UPPER LEVEL JET ENERGY WILL PERSIST OVER THE CENTRAL PLAINS THROUGH MUCH OF THE LONG TERM FORECAST PERIOD. AT THE SURFACE A RIDGE HIGH PRESSURE IS EXPECTED TO DOMINATE THE LOW LEVELS THURSDAY THROUGH MUCH OF FRIDAY...WITH LOW LEVEL RETURN FLOW MATERIALIZING ACROSS THE AREA LATE FRIDAY ONWARD. THE OPERATIONAL GFS AND EC BOTH ADVERTISE MID LEVEL PERTURBATIONS WILL PUSH OVER THE AREA DURING THE DAY THURSDAY...WITH PERHAPS ENOUGH OMEGA AND MOISTURE FOR PRECIPITATION PRODUCTION ACROSS NORTHERN PORTIONS OF THE CWA. THE RIGHT-REAR QUADRANT OF A ~70KT MID LEVEL JET STREAK IS THEN EXPECTED TO PROMOTE ENOUGH OF A DIRECT THERMAL CIRCULATION FOR PRECIPITATION PRODUCTION ACROSS MUCH OF THE CWA THURSDAY NIGHT INTO FRIDAY MORNING. AN OVERALL LACK IN KINEMATIC FORCING IS THEN EXPECTED TO BRING DRY CONDITIONS TO THE AREA DURING THE DAY FRIDAY...WITH THE EMERGENCE OF A ~40KT LOW LEVEL JET BRINGING ANOTHER POSSIBILITY OF PRECIPITATION TO THE AREA FRIDAY NIGHT INTO SATURDAY MORNING. ONE MORE ROUND OF NOCTURNAL PRECIPITATION THEN APPEARS POSSIBLE SATURDAY NIGHT INTO SUNDAY MORNING AS A STRONGER LOW LEVEL JET INFILTRATES THE AREA. LOW LEVEL MOISTURE REMAINS LESS THAN IMPRESSIVE THROUGH FRIDAY AS SURFACE RIDGING REMAINS ENTRENCHED ACROSS THE AREA AND AS A RESULT...INSTABILITY SUFFERS GREATLY. CONTEMPLATED TAKEN THUNDER OUT OF THE FORECAST ALTOGETHER THURSDAY AND THURSDAY NIGHT BUT WITH THE OPERATIONAL GFS AND EC BOTH SUGGESTING MAYBE AROUND 100J/KG DEEP LAYER MUCAPE VALUES...WENT AHEAD WITH ISOLATED THUNDER MENTION FOR THAT TIME BEING. LOW LEVEL MOISTURE FLUX INTO THE AREA VIA LOW LEVEL RETURN FLOW SHOULD ALLOW FOR INCREASING INSTABILITY VALUES HEADING INTO THE WEEKEND...WITH 1000-2000J/KG DEEP LAYER MUCAPE VALUES BEING ADVERTISED BY THE OPERATIONAL GFS AND EC. NEAR TO SLIGHTLY ABOVE-NORMAL TEMPERATURES ARE STILL EXPECTED THURSDAY AS SURFACE RIDGING REMAINS OVER THE AREA. LOW LEVEL RETURN FLOW WILL THEN PROMOTE A WARMING TREND...WITH TEMPERATURES CLIMBING TO LEVELS WELL ABOVE-NORMAL FOR THIS TIME OF YEAR ACROSS OUR SOUTH ON FRIDAY...AND ACROSS THE ENTIRE CWA SATURDAY ONWARD. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...PFANNKUCH AVIATION/LONG TERM...BRYANT
AREA FORECAST DISCUSSION
NWS HASTINGS NE
447 AM CDT MON MAY 21 2012 .SHORT TERM...ALTHOUGH THE MAJORITY OF THE NEXT 72 HOURS SHOULD REMAIN DRY...WILL HAVE TO DEAL WITH AT LEAST SOME SPRINKLES/BRIEF SHOWERS THIS MORNING MAINLY IN THE NORTH...AND EVENTUALLY WHAT SHOULD BE A MORE WIDESPREAD THUNDERSTORM RISK IN SOME AREAS WEDNESDAY EVENING/NIGHT. ALSO OF CONCERN IS POSSIBLE ADVISORY-LEVEL SOUTHERLY WIND ON TUESDAY. 08Z OBJECTIVE SURFACE ANALYSIS PLACES A BROAD 1025MB RIDGE AXIS ACROSS EASTERN NEB...PROVIDING NEAR CALM TO VERY LIGHT EAST/SOUTHEAST BREEZES TO THE CWA. ALTHOUGH MID LEVEL CLOUDS WILL BE ON THE INCREASE THROUGH SUNRISE...MAINLY CLEAR SKIES THUS FAR TONIGHT HAVE RESULTED IN AN EFFICIENT COOL DOWN INTO THE MID/UPPER 40S IN MOST AREAS. SPEAKING OF THOSE INCOMING MID CLOUDS AND INCORPORATING RADAR TRENDS...SURE ENOUGH AND AS SUSPECTED HERE 24 HOURS AGO...A NARROW NORTH-SOUTH BAND OF MID-LEVEL THETA-E ADVECTION EVIDENT AT 700MB HAS SPARKED AN AREA OF AT THE VERY LEAST SCATTERED SPRINKLES/LIGHT SHOWERS AND EVEN A FEW WEAK THUNDERSTORMS THAT HAVE SO FAR LARGELY STAYED JUST OUTSIDE THE CWA ALONG AN AXIS FROM NEAR VALENTINE TO NORTH PLATTE. WATER VAPOR IMAGERY CONFIRMS BROAD NORTHWEST FLOW ALOFT OVER THE CENTRAL PLAINS...AS THE REGION LIES ALONG THE NORTHEAST PERIPHERY OF A BUILDING MID/UPPER RIDGE AXIS EXTENDING ALL THE WAY BACK TO THE PACIFIC NORTHWEST...WHERE THE NEXT LARGER SCALE SHORTWAVE/UPPER JET STREAK OF INTEREST IS ARRIVING ON THE SCENE. THE IMMEDIATE ISSUE THROUGH AT LEAST THE NEXT 4-6 HOURS IS THE EVOLUTION OF DEVELOPING SHOWER ACTIVITY THIS MORNING. THIS NARROW CORRIDOR OF HIGH BASED CONVECTION IS CLASSICALLY LOCATED ALONG THE LEADING EDGE OF 700MB THETA-E ADVECTION...AND IMMEDIATELY EAST OF THE CORE OF THE 850MB LOW LEVEL JET CURRENTLY CENTERED FROM FAR WESTERN KS INTO WESTERN NEB. AS USUAL...DETERMINISTIC MODELS SUCH AS NAM/GFS/ECMWF ARE STRUGGLING TO FULLY CAPTURE THIS ACTIVITY IN THEIR QPF FIELDS...WHILE HIGHER RESOLUTION SHORT TERM MODELS SUCH AS THE HRRR AND 0Z 4KM WRF-NMM ARE PROVING BETTER. OBJECTIVE RUC ANALYSIS AND 06Z NAM CONFIRM THAT ELEVATED MUCAPE VALUES MAINLY IN THE 800-650MB LAYER ARE ONLY RUNNING A MEAGER 100 J/KG OR SO. FOLLOWING THE 06Z NAM...THIS BAND OF MID LEVEL THETA-E ADVECTION SHOULD CONTINUE TO STEADILY TRACK EAST MAINLY ACROSS THE NORTHERN 1/2 OF NEB THROUGH THE MORNING HOURS...AT LEAST PUTTING PARTS OF THE NORTHERN CWA IN LINE FOR NUISANCE AND UNFORTUNATELY PREVIOUSLY UN-ADVERTISED PRECIPITATION. HAVE DEBATED BETWEEN GOING WITH A MEASURABLE POP/SHOWER AND MAYBE EVEN AN ISOLATED THUNDERSTORM MENTION...BUT AT LEAST TO START OUT WITH THIS MORNING WILL TRY...REPEAT TRY...TO GET AWAY WITH ONLY SCATTERED SPRINKLE MENTION ALONG AND NORTH OF I-80 WITH EXPECTATION THAT MEASURABLE PRECIP SHOULD NOT BE OVERLY WIDESPREAD. STAY TUNED FOR POSSIBLE UPDATES HOWEVER AS RADAR TRENDS EVOLVE. OBVIOUSLY EVEN IF ANY ROGUE LIGHTNING STRIKES TO MANAGE TO SNEAK IN...WOULD NOT ANTICIPATE ANYTHING CLOSE TO BEING SEVERE...WITH EVEN SMALL HAIL HARD TO COME BY. WITH EXPECTATION OF THIS BEING A MORNING-ONLY ISSUE...HAVE NO PRECIP MENTION WITHIN THE CWA BEYOND 17Z...AS THE AFTERNOON HOURS WILL FEATURE THE PRIMARY LOWER LEVEL INSTABILITY AXIS SETTING UP WEST OF THE CWA ALONG AN AXIS FROM FAR WESTERN KS NORTHWARD INTO WESTERN NEB. MEANWHILE...SOUTH/SOUTHEAST WIND WILL BE ON THE INCREASE AS THE DAY WEARS ON...AS THE SURFACE RIDGE AXIS DEPARTS EAST INTO IA/MO. AS A RESULT...THE AFTERNOON HOURS WILL FEATURE SUSTAINED SPEEDS RANGING FROM NEAR 15 MPH IN FAR EASTERN COUNTIES...TO 20-25 MPH IN SOME WESTERN AREAS ALONG WITH GUSTS TO AROUND 30 MPH. TEMP WISE TODAY...CHANGED HIGHS LITTLE FROM PREVIOUS FORECAST...AND FOLLOWED 0Z NAM RAW TEMPS QUITE CLOSELY. ALTHOUGH PASSING MID LEVEL CLOUDS THIS MORNING COULD PUT A TEMPORARY DELAY ON THE DIURNAL CLIMB...HAVE AIMED MOST OF THE CWA INTO THE 77-81 RANGE FOR EVENTUAL HIGHS. THIS EVENING/TONIGHT...ANY STORMS THAT MANAGE TO FORM OUT IN WESTERN NEB LATE THIS AFTERNOON WITHIN THE INSTABILITY AXIS SHOULD STEADILY FADE AWAY LONG BEFORE MAKING IT INTO THE CWA. THAT BEING SAID...HAVE OPTED TO DISREGARD THE 00Z GFS SOLUTION WHICH BREAKS OUT WIDESPREAD QPF TONIGHT MAINLY IN SOUTHWEST/CENTRAL KS...BUT ALSO BRUSHING UP INTO THE KS ZONES OF OUR CWA. WITH THE NAM/ECMWF AND 4KM WRF-NMM ESSENTIALLY SHOWING NOTHING OF THIS NATURE...IT JUST SEEMS TOO MUCH AN OUTLIER AND HAVE KEPT THE ENTIRE CWA PRECIP-FREE TONIGHT. ALOFT...THE HEART OF THE MID/UPPER RIDGE AXIS WILL SET UP OVER THE CENTRAL PLAINS TONIGHT...AS THE UPSTREAM TROUGH/JET STREAK START CROSSING THE NORTHERN ROCKIES. AT THE SURFACE...STEADY SOUTHERLY BREEZES SHOULD HELP HOLD TEMPS UP ABOUT 10 DEGREES WARMER THAN THOSE THIS MORNING...AND HAVE MOST OF THE CWA IN THE 55-58 RANGE FOR LOWS...WHICH IS VERY SLIGHTLY WARMER THAN PREVIOUS FORECAST. TUESDAY IS STILL SHAPING UP TO BE THE WARMEST DAY OF THE WEEK...WITH PLENTY OF SOUTHERLY WIND TO GO WITH IT. STARTING WITH STORM CHANCES...HAVE KEPT IT STORM FREE THROUGH THE DAY...AS EVEN THOUGH DEWPOINTS WILL BE IN THE INCREASE INTO THE 50S IN MOST AREAS WITH A CORRESPONDING INCREASE IN LOW LEVEL INSTABILITY...MID LEVEL TEMPS WILL ALSO BE ON THE INCREASE...WITH NAM SOUNDINGS CONFIRMING A DECENT CAPPING INVERSION. BY LATE AFTERNOON...THE NAM/GFS/ECMWF ARE IN GENERAL AGREEMENT SETTING UP A 990-994MB LOW IN FAR WESTERN NEBRASKA...WITH PRESSURE FALLS DURING THE DAY SETTING UP QUITE A HEALTHY EAST-WEST SURFACE PRESSURE GRADIENT DURING THE DAY. THIS GRADIENT...IN TANDEM WITH SHOULD BE PLENTY OF SUN AND MIXING TO AT LEAST THE 800MB LEVEL SHOULD HELP CRANK UP THE SOUTHERLY WIND. TAKING A CONSENSUS OF 00Z MET/MAV GUIDANCE FOR SPEEDS...HAVE MOST OF THE CWA CURRENTLY TOPPING OUT IN THE 25-30 MPH RANGE FOR SUSTAINED SPEEDS...WHICH IF IT WERE TO HOLD WOULD GENERALLY FALL JUST SHORT OF WIND ADVISORY CRITERIA. HOWEVER...COULD EASILY FORESEE AT LEAST WESTERN PORTIONS OF THE CWA ENDING UP WITH HIGHER SPEEDS OVER 30 MPH...AND ALTHOUGH WILL FOREGO ANY HEADLINE ISSUANCE STILL BEING 3 PERIODS OUT...WILL CONTINUE TO HIGHLIGHT AT LEAST NEAR-ADVISORY SPEEDS IN THE HWO. CERTAINLY GUSTS TO AROUND 40 MPH SHOULD BE COMMON NO MATTER WHAT DURING THE AFTERNOON. TEMP-WISE...AGAIN LEANED HEAVILY ON RAW 0Z NAM NUMBERS...WHICH RESULTED IN LITTLE CHANGE FROM PREVIOUS ACROSS EASTERN ZONES...BUT ACTUALLY A SLIGHT LOWERING IN WESTERN AREAS. THIS RESULTS IN MOST AREAS TOPPING OUT BETWEEN 87-90...WHICH IS STILL AT LEAST A FEW DEGREES ABOVE MET GUIDANCE. IF SURFACE DEWPOINTS MANAGE TO MIX DOWN FURTHER THAN CURRENTLY THOUGHT...THEN COULD EASILY SEE PARTS OF THE SOUTHWEST CWA TRY TO MAKE A RUN AT MID 90S BUT WILL KEEP IT BELOW THIS FOR NOW. TUESDAY NIGHT...KEPT IT STORM FREE DESPITE THE LEADING EDGE FORCING FROM THE INCOMING SHORTWAVE/JET STREAK STARTING TO IMPINGE ON WESTERN PORTIONS OF THE REGION. ALTHOUGH THE LOW LEVEL JET WILL REALLY RAMP UP OVER THE CWA DURING THE NIGHT...SPEED CONVERGENCE IS NOT REALLY PRESENT AND MORE IMPORTANTLY...VERY WARM MID LEVEL TEMPS AS EVIDENCED BY 700MB TEMPS CLIMBING INTO AT LEAST THE 12-14C RANGE SHOULD PROVIDE A VERY STOUT CAP EVEN TO ELEVATED PARCELS. EVEN WITH THE APPROACH OF A SURFACE-850MB COLD FRONT AFTER MIDNIGHT ACROSS WESTERN NEB...JUST NOT SEEING THIS CAP BREAKING WITH LARGE SCALE FORCING STILL LIMITED. TEMP WISE...SHOULD BE A SEASONABLY MILD NIGHT AND LEFT LOWS PRETTY MUCH ALONE IN THE LOW-MID 60S. WEDNESDAY DAYTIME...OPTED TO STAY CONSISTENT WITH PREVIOUS FORECAST AND LEAVE OUT STORM MENTION...BUT WILL SAY THAT WOULD NOT BE SURPRISED IF AT LEAST A SLIGHT POP COULD BE ADDED AT SOME POINT. THE MAIN THING HOLDING BACK A LEGITIMATE DAYTIME STORM THREAT IS CONTINUED STRONG CAPPING...WITH THE LATEST 06Z NAM FINALLY FALLING IN LINE WITH THE GFS/ECWMF SOLUTIONS IN KEEPING FAIRLY TOASTY 700MB TEMPS IN PLACE THROUGH THE DAY...DESPITE THE INVASION OF A SURFACE COLD FRONT INTO NORTHWEST PARTS OF THE CWA. EVEN THE LATEST RUN OF THE SREF THUNDER PROBABILITIES HAS BACKED OFF A BIT ON THE FAIRLY SLIM RISK OF PRE-00Z CONVECTIVE INITIATION. ASSUMING THAT IT REMAINS STORM-FREE...THE MAIN ISSUE FOR WEDNESDAY IS A TRICKY HIGH TEMP FORECAST...AS ALTHOUGH THE SOUTHEAST 1/2 OR SO OF THE CWA SHOULD REMAIN FIRMLY IN THE WARM SECTOR...NORTHWEST ZONES COULD SEE AT LEAST WEAK COLD AIR ADVECTION/NORTHEAST WIND. OPTED TO WARM UP MOST AREAS 2-3 DEGREES FROM PREVIOUS FORECAST SIDING WITH SLOWER INVASION OF COOLER AIR...NOW ADVERTISING A RANGE FROM NEAR 80 FAR NORTHWEST TO LOW 90S SOUTHEAST. WEDNESDAY NIGHT...THIS IS CLEARLY THE MOST FAVORED PERIOD FOR POTENTIALLY...REPEATING POTENTIALLY WIDESPREAD THUNDERSTORM ACTIVITY...AS MID LEVEL TEMPS SHOULD BE ABLE TO COOL ENOUGH AT LEAST IN NORTHWEST ZONES TO ALLOW INITIATION. ON THE LARGER SCALE...LEGITIMATE FORCING FINALLY ARRIVES IN THE FORM OF AN OPEN MID LEVEL SHORTWAVE AND THE EXIT REGION OF A 300MB JET STREAK APPROACHING FROM THE CENTRAL ROCKIES. THAT BEING SAID...LATEST MODEL CONSENSUS IS TO REALLY LIMIT STORM DEVELOPMENT ACROSS SOUTHEAST ZONES...WHILE MAINLY TARGETING NORTHWEST ZONES WITH CONVECTION...AND LEAVING CENTRAL PLACES INCLUDING THE TRI CITIES A BIT IN LIMBO. FOR NOW...OPTED TO KEEP POPS SIMILAR TO PREVIOUS FORECAST...RANGING FROM LIKELY 60S IN THE NORTHWEST TO NO STORM MENTION FAR SOUTHEAST...AND A GRADUAL GRADIENT OF SLIGHT CHANCE TO CHANCE POPS IN BETWEEN. THE POTENTIAL IS CERTAINLY THERE FOR A WIDESPREAD FLARE UP OF STORMS...AS THE NAM ADVERTISES CONSIDERABLE CONVERGENCE ACROSS A SHARP 850MB FRONT...WITH A LOW LEVEL JET POTENTIALLY IN EXCESS OF 60KT BLASTING INTO THIS BOUNDARY. WITH ELEVATED INSTABILITY POTENTIALLY INTO THE 1000-2000 J/KG RANGE IN THE EVENING...ALONG WITH DEEP LAYER SHEAR ON THE ORDER OF 50-70KT...A ROUND OF SEVERE STORMS WITH HAIL/WIND IS VERY POSSIBLE...AGAIN MAINLY FAVORING THE LESS-CAPPED NORTHWEST ZONES. CERTAINLY PLENTY OF DETAILS TO IRON OUT OVER THE NEXT FEW DAYS THOUGH. .LONG TERM...STARTING 12Z THURSDAY. GUIDANCE CONTINUES TO SUGGEST MID AND UPPER LEVEL JET ENERGY WILL PERSIST OVER THE CENTRAL PLAINS THROUGH MUCH OF THE LONG TERM FORECAST PERIOD. AT THE SURFACE A RIDGE HIGH PRESSURE IS EXPECTED TO DOMINATE THE LOW LEVELS THURSDAY THROUGH MUCH OF FRIDAY...WITH LOW LEVEL RETURN FLOW MATERIALIZING ACROSS THE AREA LATE FRIDAY ONWARD. THE OPERATIONAL GFS AND EC BOTH ADVERTISE MID LEVEL PERTURBATIONS WILL PUSH OVER THE AREA DURING THE DAY THURSDAY...WITH PERHAPS ENOUGH OMEGA AND MOISTURE FOR PRECIPITATION PRODUCTION ACROSS NORTHERN PORTIONS OF THE CWA. THE RIGHT-REAR QUADRANT OF A ~70KT MID LEVEL JET STREAK IS THEN EXPECTED TO PROMOTE ENOUGH OF A DIRECT THERMAL CIRCULATION FOR PRECIPITATION PRODUCTION ACROSS MUCH OF THE CWA THURSDAY NIGHT INTO FRIDAY MORNING. AN OVERALL LACK IN KINEMATIC FORCING IS THEN EXPECTED TO BRING DRY CONDITIONS TO THE AREA DURING THE DAY FRIDAY...WITH THE EMERGENCE OF A ~40KT LOW LEVEL JET BRINGING ANOTHER POSSIBILITY OF PRECIPITATION TO THE AREA FRIDAY NIGHT INTO SATURDAY MORNING. ONE MORE ROUND OF NOCTURNAL PRECIPITATION THEN APPEARS POSSIBLE SATURDAY NIGHT INTO SUNDAY MORNING AS A STRONGER LOW LEVEL JET INFILTRATES THE AREA. LOW LEVEL MOISTURE REMAINS LESS THAN IMPRESSIVE THROUGH FRIDAY AS SURFACE RIDGING REMAINS ENTRENCHED ACROSS THE AREA AND AS A RESULT...INSTABILITY SUFFERS GREATLY. CONTEMPLATED TAKEN THUNDER OUT OF THE FORECAST ALTOGETHER THURSDAY AND THURSDAY NIGHT BUT WITH THE OPERATIONAL GFS AND EC BOTH SUGGESTING MAYBE AROUND 100J/KG DEEP LAYER MUCAPE VALUES...WENT AHEAD WITH ISOLATED THUNDER MENTION FOR THAT TIME BEING. LOW LEVEL MOISTURE FLUX INTO THE AREA VIA LOW LEVEL RETURN FLOW SHOULD ALLOW FOR INCREASING INSTABILITY VALUES HEADING INTO THE WEEKEND...WITH 1000-2000J/KG DEEP LAYER MUCAPE VALUES BEING ADVERTISED BY THE OPERATIONAL GFS AND EC. NEAR TO SLIGHTLY ABOVE-NORMAL TEMPERATURES ARE STILL EXPECTED THURSDAY AS SURFACE RIDGING REMAINS OVER THE AREA. LOW LEVEL RETURN FLOW WILL THEN PROMOTE A WARMING TREND...WITH TEMPERATURES CLIMBING TO LEVELS WELL ABOVE-NORMAL FOR THIS TIME OF YEAR ACROSS OUR SOUTH ON FRIDAY...AND ACROSS THE ENTIRE CWA SATURDAY ONWARD. && .PREV DISCUSSION... /ISSUED 1151 PM CDT SUN MAY 20 2012/ AVIATION...06Z KGRI TAF. THE WIND WILL BE LIGHT AND VARIABLE THROUGH THE NIGHT. THERE WILL BE AN INCREASE IN THE SOUTHEASTERLY WIND BY MID MORNING BUT NOTHING TOO GUSTY. VFR CONDITIONS WILL PREVAIL THROUGHOUT THE PERIOD. THERE WILL BE FEW TO SCATTERED HIGH CLOUDS BUT THERE SHOULD BE NO WEATHER RELATED AVIATION CONCERNS. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...PFANNKUCH LONG TERM...BRYANT
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1006 PM EDT TUE MAY 22 2012 .SYNOPSIS... HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT AND THEN WEAKEN WEDNESDAY NIGHT. A WARM FRONT WILL MOVE ACROSS THE AREA THURSDAY. A WEAK COLD FRONT WILL MOVE IN FRIDAY AND THEN MOVE BACK NORTH AS A WARM FRONT SATURDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... SATELLITE SHOWING THE CONTINUED CLEARING TREND ACROSS THE AREA. TEMPS FALLING AS ANTICIPATED WITH DEWPOINTS IN THE LOWER 50S. SOME MODELS CONTINUING TO INDICATE FOG DEVELOPING OVERNIGHT. SOME MODELS SUCH AS THE HRRR NOT INDICATING WIDESPREAD FOG WHILE LATEST LAMP GUIDANCE STILL SHOWING FOG ACROSS THE AREA. WITH RECENT RAINFALL BEING MORE ISOLATED ACROSS THE AREA THERE ISN/T AN ABUNDANT AMOUNT OF SFC MOISTURE TO AID FOR FOG DEVELOPMENT. ONLY CHANGE TO FORECAST WAS THE REMOVAL OF THE TERM DENSE TO THE FOG OVERNIGHT...BUT DID CONTINUE TO MENTION IT. AT THIS TIME WILL NOT ISSUE ANY ADVISORIES GIVEN MARGINAL CONFIDENCE ON LOCATION AND INTENSITY OF FOG ACROSS THE AREA. PREVIOUS DISCUSSION BELOW. A HIGH PRESSURE RIDGE WILL BE MOVING INTO THE AREA TONIGHT. THE BIG QUESTION IS HOW MUCH FOG WILL FORM. SOME OF THE MODELS ARE INDICATING WIDESPREAD DENSE FOG DEVELOPING. ON THE EDGE ABOUT THAT SINCE WE DID NOT HAVE WIDESPREAD RAIN AND DRIER AIR WILL DRY TO MOVE IN...HOWEVER...WE WILL NOT HAVE MUCH SUNSHINE BEFORE SUNSET OVER NORTHEAST OHIO AND NORTHWEST PA TO DRY THINGS OUT. WILL MENTION AREAS OF DENSE FOG AND HAVE THE NEXT SHIFT MONITOR FOR A POSSIBLE DENSE FOG ADVISORY. USED A MIX OF THE MOS GUIDANCE FOR THE LOWS. THE NAM GUIDANCE SEEMS TOO WARM OVER NORTHWEST OHIO BASED ON CLEARING SKIES AND LIGHT WINDS. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY NIGHT/... THE SHORT TERM WILL BE MAINLY DRY BUT THERE WILL BE A LOW THREAT OF SHOWERS AND THUNDERSTORMS AT TIMES AND IN VARYING LOCATIONS. THE RIDGE WILL BE OVER THE AREA ON WEDNESDAY WITH PARTLY TO MOSTLY SUNNY SKIES. THE UPPER LOW OVER THE CAROLINAS MAY TRY TO MOVE SOME SHOWERS AND THUNDERSTORMS TO NORTHEAST OH...BUT WILL KEEP IT DRY ATTM. A WARM FRONT WILL MOVE ACROSS THE AREA THURSDAY...GOING WITH SLIGHT CHANCE POPS AS CONFIDENCE IS LOW AND THEN SLIGHT CHANCE POPS FRIDAY AND FRIDAY NIGHT AS WEAK COLD FRONT MOVES ACROSS THE AREA. USED A MIX OF GUIDANCE FOR THE TEMPERATURES. && .LONG TERM /SATURDAY THROUGH TUESDAY/... NO CHANGES TO THE HOLIDAY WEEKEND FORECAST. FRONTAL BOUNDARY WILL BE IN THE VICINITY SATURDAY...BUT WILL PUSH NORTH OF THE AREA BY SUNDAY. MONDAY WE WILL BE SITTING HIGH AND DRY UNDER HIGH PRESSURE. A COLD FRONT SLIPS THROUGH TUESDAY. H8 TEMPS PUSH +20C AND SURFACE TEMPS WILL BE FLIRTING WITH 90...ESPECIALLY SUNDAY AND MONDAY. SATURDAYS HIGHS MAY BE LIMITED SOME BY THE FRONT BEING NEARBY...BUT STILL BE ABOVE NORMAL. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... ALL OF THE LATEST GUIDANCE CONTINUES TO SUGGEST THAT IFR AND LIFR CONDITIONS WILL DEVELOP OVERNIGHT WITH FOG. THE STRATO CU THAT BLANKETED MUCH OF THE AREA TODAY HAS FINALLY DISSIPATED. VERY LITTLE FLOW EXPECTED TONIGHT SO THE AIRMASS IN PLACE WILL NOT BE MODIFIED. WITH FAIRLY HIGH DEWPOINTS IN PLACE IT LOOKS LIKE FOG/STRATUS ARE A GOOD BET. THE EXCEPTION TO THIS WILL BE AT KTOL WHERE SOMEWHAT DRIER AIR HAS ARRIVED. WILL TAKE THINGS DOWN TO IFR MOST LOCATIONS BY 06Z. WILL SEE ONLY A SLOW IMPROVEMENT TOMORROW MORNING. WINDS AFTER DARK WILL BE VARIABLE AT UNDER 5 KNOTS. .OUTLOOK...NON-VFR POSSIBLE IN MORNING BR/FG. && .MARINE... HIGH PRESSURE WILL BUILD OVER LAKE ERIE TONIGHT WITH LIGHT LAKE BREEZES AND GOOD MARINE CONDITIONS EXPECTED ON WEDNESDAY. SOUTHERLY FLOW WILL DEVELOP LATE THURSDAY INTO FRIDAY AHEAD OF A LOW PRESSURE SYSTEM TRACKING NORTHEAST THROUGH THE WESTERN AND UPPER GREAT LAKES. THIS SYSTEM WILL PUSH A WEAK FRONTAL BOUNDARY SOUTH TOWARDS LAKE ERIE ON FRIDAY NIGHT...STALLING IN THE VICINITY OF THE LAKE ON SATURDAY. LIGHT SOUTHERLY FLOW WILL DEVELOP AGAIN BY SUNDAY WITH WELL ABOVE NORMAL TEMPERATURES AND STABLE CONDITIONS EXPECTED FOR THE HOLIDAY WEEKEND. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KIELTYKA NEAR TERM...ABE/KIELTYKA SHORT TERM...KIELTYKA LONG TERM...OUDEMAN AVIATION...KUBINA MARINE...KEC
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
748 AM EDT MON MAY 21 2012 .SYNOPSIS... AN UPPER LOW OVER THE SOUTHEAST COAST WILL OPEN UP AND LIFT NORTHEAST TODAY AND TONIGHT. A DEEPENING SHORTWAVE WILL SLOW DOWN AND CUT OFF OVR THE CENTRAL APPALACHIANS DURING THE MIDDLE OF THE WEEK. PENNSYLVANIA WILL BE ON THE EDGE OF THE REBUILDING UPPER RIDGE ACROSS THE OHIO VALLEY BY THE END OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPPER LOW OVER THE CAROLINA COAST WILL LIFT NORTH ALONG THE E COAST DURING THE NEXT 24HRS. ASSOCIATED MOIST...EASTERLY LL JET AND UPPER LVL DIVERGENCE PRECEDING THE UPPER LOW WILL BRING SHOWERS TO MOST OF CENTRAL PA TODAY. RADAR SHOWS SCT SHOWERS HAVE ALREADY OVERSPREAD THE LOWER SUSQ VALLEY AS OF 09Z AND LATEST RUC AND 4KM NAM SUGGEST NORTHERN EDGE OF SHOWERS/DRIZZLE WILL REACH FROM ARND JST TO IPT BY LATE MORNING. CLOUD COVER...PRECIP AND EASTERLY FLOW OFF THE ATLANTIC WILL RESULT IN MUCH COOLER TEMPS TODAY WITH MAXIMUMS ONLY ARND 70F. BLEND OF OPER AND ENSEMBLE QPF INDICATES LIKELY RAINFALL AMTS TODAY OF BTWN 0.1 AND 0.2 INCHES. DOWNSLOPING SE FLOW WILL RESULT IN PARTIAL SUNSHINE AND A SOMEWHAT WARMER MONDAY OVR WARREN COUNTY...WHERE A LATE DAY TSRA IS POSSIBLE. OPER GFS/NAM INDICATE CAPE VALUES NR 1000JK-1 ACROSS WARREN CO BY THIS EVENING. FURTHER EAST...A COOLER MORE STABLE EASTERLY FLOW WILL LIKELY PRECLUDE THUNDER. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... SCT SHRA WILL CONTINUE TO FALL OVER CENTRAL PA TONIGHT...AS MOIST EASTERLY LL JET AND UPPER LVL DIVERGENCE REMAIN OVR THE AREA IN ADVANCE OF UPPER LOW. A GENERAL DECREASE IN SHOWER ACTIVITY IS EXPECTED LATE TONIGHT AS UPPER LOW OPENS UP AND LIFTS NE. BIGGER STORY LATE TONIGHT COULD BE AREAS OF POTENTIALLY DENSE FOG. PLENTY OF LL MOISTURE AND A NEARLY CALM WIND WILL BE FAVORABLE FOR FOG. AS E COAST UPPER LOW OPENS UP AND LIFTS INTO THE CANADIAN MARITIMES...UPSTREAM SHORTWAVE WILL DEEPEN AND CUT OFF OVR THE TENN VALLEY ON TUESDAY. LG SCALE FORCING AHEAD OF THIS FEATURE WILL PRODUCE MORE SHRA/TSRA TUESDAY. GEFS/SREF DATA BOTH SUGGEST BEST CHC OF SHRA/TSRA WILL BE ALONG THE SPINE OF THE APPALACHIANS. OVERCAST SKIES AND VERY LGT WINDS ALOFT SUGGEST THERE WILL BE VERY LITTLE THREAT OF SVR WX. BLEND OF GEFS/SREF QPF RANGES FROM 0.2 TO 0.3 INCHES TONIGHT AND TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... RELATIVELY GOOD AGREEMENT AMONG MED RANGE GUIDANCE LATER THIS WEEK...ALL OF WHICH INDICATES UPPER LOW SLOWLY LIFTING NORTH ALONG THE CENTRAL APPALACHIANS. THIS SCENARIO SUPPORTS THE CHC OF DIURNALLY ENHANCED SHRA/TSRA WED-THU AND POSSIBLY EVEN FRIDAY. NEARLY ALL MDL DATA TRACKS TS ALBERTO WELL EAST OFF THE MID ATLANTIC COAST TUE NIGHT WITH NO DIRECT IMPACT ON PA. TEMPS THIS WEEK LOOK TO BE ABOVE NORMAL...MAINLY DUE TO WARM OVERNIGHT LOWS. DEEP SOUTHERLY FLOW AHEAD OF UPPER LOW WILL TRANSPORT ABOVE NORMAL MOISTURE NORTH ALONG THE E COAST...RESULTING IN THE WARM NIGHTS. EVEN WARMER WX APPEARS VERY LIKELY BY NEXT WEEKEND WHEN ALL MDL DATA INDICATES A BUILDING UPPER LVL RIDGE OVER THE OHIO VALLEY. HOWEVER...PA MAY BE ON PERIPHERY OF THIS FEATURE...PLACING AT LEAST NORTHERN PA IN RING OF FIRE WITH CHC OF PM CONVECTION. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... AN UPPER LOW OVER THE SOUTHEAST COAST WILL OPEN UP AND LIFT NORTHEAST TODAY AND TONIGHT...AND AN INCREASING LL JET WILL BRING MOIST SOUTHEAST FLOW AND GENERALLY POOR FLYING CONDITIONS TO THE REGION OVER THE NEXT SEVERAL DAYS. INCREASING MOISTURE HAS ALREADY RESULTED IN LOWERING CIGS ACROSS MUCH OF CENTRAL PA. IFR CIGS PREVALENT IN THE LOWER SUSQ...WITH MVFR GRADUALLY SPREADING NW ACROSS CENTRAL MTNS. SHOWERS WILL ALSO INCREASE FROM THE SE DURING THE DAY TODAY...WITH NORTHERN EDGE OF SHOWERS REACHING FROM AROUND JST-UNV-IPT BY LATE MORNING. CIGS DETERIORATE FURTHER OVERNIGHT...BECOMING IFR AS AN UPPER LEVEL TROF APPROACHES FROM THE GREAT LAKES. OUTLOOK... MON NIGHT-WED...WIDESPREAD MVFR/IFR CIGS AND VSBYS LIKELY IN SHOWERS AND SCT TSRA. THU...PRIMARILY VFR. SCT SHRA/TSTM POSS MAINLY SE. FRI...PRIMARILY VFR. ISOLD SHRA/TSTM POSS MAINLY SE. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...FITZGERALD NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD LONG TERM...FITZGERALD/MARTIN AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
550 AM EDT MON MAY 21 2012 .SYNOPSIS... AN UPPER LOW OVER THE SOUTHEAST COAST WILL OPEN UP AND LIFT NORTHEAST TODAY AND TONIGHT. A DEEPENING SHORTWAVE WILL SLOW DOWN AND CUT OFF OVR THE CENTRAL APPALACHIANS DURING THE MIDDLE OF THE WEEK. PENNSYLVANIA WILL BE ON THE EDGE OF A BUILDING 500 HPA RIDGE ACROSS THE OHIO VALLEY BY THE END OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPPER LOW OVER THE CAROLINA COAST WILL LIFT NORTH ALONG THE E COAST DURING THE NEXT 24HRS. ASSOCIATED MOIST...EASTERLY LL JET AND UPPER LVL DIVERGENCE PRECEDING THE UPPER LOW WILL BRING SHOWERS TO MOST OF CENTRAL PA TODAY. RADAR SHOWS SCT SHOWERS HAVE ALREADY OVERSPREAD THE LOWER SUSQ VALLEY AS OF 09Z AND LATEST RUC AND 4KM NAM SUGGEST NORTHERN EDGE OF SHOWERS/DRIZZLE WILL REACH FROM ARND JST TO IPT BY LATE MORNING. CLOUD COVER...PRECIP AND EASTERLY FLOW OFF THE ATLANTIC WILL RESULT IN MUCH COOLER TEMPS TODAY WITH MAXIMUMS ONLY ARND 70F. BLEND OF OPER AND ENSEMBLE QPF INDICATES LIKELY RAINFALL AMTS TODAY OF BTWN 0.1 AND 0.2 INCHES. DOWNSLOPING SE FLOW WILL RESULT IN PARTIAL SUNSHINE AND A SOMEWHAT WARMER MONDAY OVR WARREN COUNTY...WHERE A LATE DAY TSRA IS POSSIBLE. OPER GFS/NAM INDICATE CAPE VALUES NR 1000JK-1 ACROSS WARREN CO BY THIS EVENING. FURTHER EAST...A COOLER MORE STABLE EASTERLY FLOW WILL LIKELY PRECLUDE THUNDER. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... SCT SHRA WILL CONTINUE TO FALL OVER CENTRAL PA TONIGHT...AS MOIST EASTERLY LL JET AND UPPER LVL DIVERGENCE REMAIN OVR THE AREA IN ADVANCE OF UPPER LOW. A GENERAL DECREASE IN SHOWER ACTIVITY IS EXPECTED LATE TONIGHT AS UPPER LOW OPENS UP AND LIFTS NE. BIGGER STORY LATE TONIGHT COULD BE AREAS OF POTENTIALLY DENSE FOG. PLENTY OF LL MOISTURE AND A NEARLY CALM WIND WILL BE FAVORABLE FOR FOG. AS E COAST UPPER LOW OPENS UP AND LIFTS INTO THE CANADIAN MARITIMES...UPSTREAM SHORTWAVE WILL DEEPEN AND CUT OFF OVR THE TENN VALLEY ON TUESDAY. LG SCALE FORCING AHEAD OF THIS FEATURE WILL PRODUCE MORE SHRA/TSRA TUESDAY. GEFS/SREF DATA BOTH SUGGEST BEST CHC OF SHRA/TSRA WILL BE ALONG THE SPINE OF THE APPALACHIANS. OVERCAST SKIES AND VERY LGT WINDS ALOFT SUGGEST THERE WILL BE VERY LITTLE THREAT OF SVR WX. BLEND OF GEFS/SREF QPF RANGES FROM 0.2 TO 0.3 INCHES TONIGHT AND TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... RELATIVELY GOOD AGREEMENT AMONG MED RANGE GUIDANCE LATER THIS WEEK...ALL OF WHICH INDICATES UPPER LOW SLOWLY LIFTING NORTH ALONG THE CENTRAL APPALACHIANS. THIS SCENARIO SUPPORTS THE CHC OF DIURNALLY ENHANCED SHRA/TSRA WED-THU AND POSSIBLY EVEN FRIDAY. NEARLY ALL MDL DATA TRACKS TS ALBERTO WELL EAST OFF THE MID ATLANTIC COAST TUE NIGHT WITH NO DIRECT IMPACT ON PA. TEMPS THIS WEEK LOOK TO BE ABOVE NORMAL...MAINLY DUE TO WARM OVERNIGHT LOWS. DEEP SOUTHERLY FLOW AHEAD OF UPPER LOW WILL TRANSPORT ABOVE NORMAL MOISTURE NORTH ALONG THE E COAST...RESULTING IN THE WARM NIGHTS. EVEN WARMER WX APPEARS VERY LIKELY BY NEXT WEEKEND WHEN ALL MDL DATA INDICATES A BUILDING UPPER LVL RIDGE OVER THE OHIO VALLEY. HOWEVER...PA MAY BE ON PERIPHERY OF THIS FEATURE...PLACING AT LEAST NORTHERN PA IN RING OF FIRE WITH CHC OF PM CONVECTION. && .AVIATION /09Z MONDAY THROUGH FRIDAY/... HIGH PRESSURE NOW MOVING OFF TO THE NORTHEAST. AN INCREASING MOIST EAST TO SOUTHEAST FLOW HAS ALREADY BEGUN TO PUSH ATLANTIC MOISTURE INTO CENTRAL PA...RESULTING IN MVFR CIGS ALREADY WORKING INTO THE LOWER SUSQ. THESE LOWER CLOUDS WILL CONTINUE TO GRADUALLY SPREAD NW THROUGH THE MORNING HOURS...EVENTUALLY ENCOMPASSING ALL TAF SITES EXCEPT KBFD...AND LOWERING CIGS IN THE LOWER SUSQ /KMDT- KLNS/ TO IFR. SHOWERS WILL ALSO INCREASE FROM THE SE DURING THE DAY TODAY. CIGS MAY RECOVER TO MVFR THIS AFTERNOON...WITH A TSTM EMBEDDED IN THE NUMEROUS SHOWERS. BUT CIGS DROP AGAIN AND WILL BECOME IFR AREAWIDE OVERNIGHT AS AS AN UPPER LEVEL TROF APPROACHES FROM THE GREAT LAKES. OUTLOOK... MON NIGHT-WED...WIDESPREAD MVFR/IFR CIGS AND VSBYS LIKELY IN SHOWERS AND SCT TSRA. THU...PRIMARILY VFR. SCT SHRA/TSTM POSS MAINLY SE. FRI...PRIMARILY VFR. ISOLD SHRA/TSTM POSS MAINLY SE. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...FITZGERALD NEAR TERM...FITZGERALD SHORT TERM...FITZGERALD LONG TERM...FITZGERALD AVIATION...JUNG/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
221 AM EDT MON MAY 21 2012 .SYNOPSIS... HIGH PRESSURE WILL PUSH WELL OFF THE COASTAL NEW ENGLAND WATERS TONIGHT. AN INCREASING MOIST EAST TO SOUTHEAST FLOW WILL PUSH ATLANTIC MOISTURE INTO CENTRAL PENNSYLVANIA EARLY MONDAY MORNING...AS AN UPPER LEVEL TROF MOVES TO THE CENTRAL GREAT LAKES ON MONDAY. THIS WILL BRING AN INCREASING CHANCE OF SHOWERS TO ALL OF CENTRAL PA ON MONDAY. AN UPPER LEVEL LOW OVER THE SOUTHEAST WILL SLOWLY TRACK NORTHEASTWARD THROUGH MID WEEK...KEEPING UNSETTLED WEATHER ALONG THE EASTERN SEABOARD...AND A DAILY CHANCE OF SHOWERS AND THUNDERSTORMS OVER CENTRAL PENNSYLVANIA. PENNSYLVANIA WILL BE ON THE EDGE OF A BUILDING A LARGE UPPER HIGH ACROSS THE TENNESSEE RIVER VALLEY AND SOUTHEASTERN STATES BY THE END OF THIS WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... STRATUS AND SCT SHRA OVERSPREADING SOUTHEAST PA EARLY THIS MORNING...AS UPPER LOW AND ATTENDANT MOIST...EASTERLY LL JET LIFTS UP THE E COAST. LATEST RUC AND 4KM NAM SUGGEST NORTHERN EDGE OF SHOWERS/DRIZZLE WILL REACH FROM ARND BEDFORD TO SELINSGROVE BY DAWN. INCREASING DWPTS AND CLOUD COVER WILL RESULT IN A MUCH MILDER NIGHT THAN WE/VE SEEN RECENTLY WITH MIN TEMPS RANGING FROM THE M50S ACROSS THE ALLEGHENY MTNS...TO THE L60S ACROSS THE LOWER SUSQ VALLEY. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/... NO CHANGES TO THE THINKING ON MONDAY AS UPPER LOW OVER THE SOUTHEAST CONUS WILL LIFT NORTH ALONG THE E COAST. ASSOCIATED MOIST...EASTERLY LL JET AND UPPER LVL DIVERGENCE PRECEDING THE UPPER LOW WILL LIKELY BRING SCT SHOWERS TO CENTRAL PA BEGINNING LATE TONIGHT ACROSS THE SOUTHEAST ZONES AND OVERSPREADING THE REST OF CENTRAL PA DURING MONDAY. CLOUD COVER...PRECIP AND EASTERLY FLOW OFF THE ATLANTIC WILL RESULT IN A MUCH COOLER MONDAY WITH MAX TEMPS ONLY ARND 70F. GEFS DATA SHOWING HIGHEST PWATS ACROSS SOUTHEAST PA...WHERE THE BEST CHC OF MEASURABLE RAINFALL IS EXPECTED SUN NITE/MONDAY. DOWNSLOPING SE FLOW WILL RESULT IN PARTIAL SUNSHINE AND A SOMEWHAT WARMER MONDAY OVR WARREN COUNTY...WHERE A LATE DAY TSRA IS POSSIBLE. CAPE VALUES IN THE 600 TO 800JK-1 RANGE ACROSS WARREN CO MON EVENING. FURTHER EAST...A COOLER MORE STABLE EASTERLY FLOW SHOULD PRECLUDE THUNDER. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... NOT A LOT OF CHANGE FROM THE FCST PACKAGE YESTERDAY. STILL LOOKS LIKE NORTHERN SYSTEM OFF THE COAST WILL PIVOT AROUND ALBERTO AND MOVE WESTWARD...BRINGING SHOWERS TO THE AREA ON TUE. MAIN CHC WILL BE MONDAY INTO TUE. DID UP TEMPS SOME ON TUE...ALSO SOME CHC OF A THUNDERSTORM WITH THE WARMER TEMPS. SHOWERS COULD LINGER INTO WED...ESPECIALLY ACROSS THE SE WITH THE FRONT. TRIED TO GO WITH THE MID SHIFT FCST AND HAVE SOME PERIODS OF DRY WEATHER. HARD TO FIND A LOT OF DRY PERIODS...AS REMAINS OF CUTOFF COULD KEEP A FEW SHOWERS ACROSS EASTERN AREAS...WHERE FAR NW AREAS COULD SEE SOME FROM THE COLD FRONT LATE IN THE WEEK. WENT WITH A DRY FCST FOR SUNDAY...IT WILL BE CLOSE...HARD TO SEE THE EAST...WEST COLD FRONT DROPPING TOO FAR SOUTH. TEMPS WILL BE WARM THROUGHOUT THE PERIOD...ABOVE NORMAL. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... HIGH PRESSURE NOW MOVING OFF TO THE NORTHEAST. AN INCREASING MOIST EAST TO SOUTHEAST FLOW HAS ALREADY BEGUN TO PUSH ATLANTIC MOISTURE INTO CENTRAL PA...RESULTING IN MVFR CIGS ALREADY WORKING INTO THE LOWER SUSQ. THESE LOWER CLOUDS WILL CONTINUE TO GRADUALLY SPREAD NW THROUGH THE MORNING HOURS...EVENTUALLY ENCOMPASSING ALL TAF SITES EXCEPT KBFD...AND LOWERING CIGS IN THE LOWER SUSQ /KMDT- KLNS/ TO IFR. SHOWERS WILL ALSO INCREASE FROM THE SE DURING THE DAY TODAY. CIGS MAY RECOVER TO MVFR THIS AFTERNOON...WITH A TSTM EMBEDDED IN THE NUMEROUS SHOWERS. BUT CIGS DROP AGAIN AND WILL BECOME IFR AREAWIDE OVERNIGHT AS AS AN UPPER LEVEL TROF APPROACHES FROM THE GREAT LAKES. OUTLOOK... MON NIGHT-WED...WIDESPREAD MVFR/IFR CIGS AND VSBYS LIKELY IN SHOWERS AND SCT TSRA. THU...PRIMARILY VFR. SCT SHRA/TSTM POSS MAINLY SE. FRI...PRIMARILY VFR. ISOLD SHRA/TSTM POSS MAINLY SE. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...GRUMM/FITZGERALD NEAR TERM...FITZGERALD SHORT TERM...DEVOIR LONG TERM...MARTIN AVIATION...JUNG/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
145 AM EDT MON MAY 21 2012 .SYNOPSIS... HIGH PRESSURE WILL PUSH WELL OFF THE COASTAL NEW ENGLAND WATERS TONIGHT. AN INCREASING MOIST EAST TO SOUTHEAST FLOW WILL PUSH ATLANTIC MOISTURE INTO CENTRAL PENNSYLVANIA EARLY MONDAY MORNING...AS AN UPPER LEVEL TROF MOVES TO THE CENTRAL GREAT LAKES ON MONDAY. THIS WILL BRING AN INCREASING CHANCE OF SHOWERS TO ALL OF CENTRAL PA ON MONDAY. AN UPPER LEVEL LOW OVER THE SOUTHEAST WILL SLOWLY TRACK NORTHEASTWARD THROUGH MID WEEK...KEEPING UNSETTLED WEATHER ALONG THE EASTERN SEABOARD...AND A DAILY CHANCE OF SHOWERS AND THUNDERSTORMS OVER CENTRAL PENNSYLVANIA. PENNSYLVANIA WILL BE ON THE EDGE OF A BUILDING A LARGE UPPER HIGH ACROSS THE TENNESSEE RIVER VALLEY AND SOUTHEASTERN STATES BY THE END OF THIS WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... STRATUS AND SCT SHRA OVERSPREADING SOUTHEAST PA EARLY THIS MORNING...AS UPPER LOW AND ATTENDANT MOIST...EASTERLY LL JET LIFTS UP THE E COAST. LATEST RUC AND 4KM NAM SUGGEST NORTHERN EDGE OF SHOWERS/DRIZZLE WILL REACH FROM ARND BEDFORD TO SELINSGROVE BY DAWN. INCREASING DWPTS AND CLOUD COVER WILL RESULT IN A MUCH MILDER NIGHT THAN WE/VE SEEN RECENTLY WITH MIN TEMPS RANGING FROM THE M50S ACROSS THE ALLEGHENY MTNS...TO THE L60S ACROSS THE LOWER SUSQ VALLEY. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/... NO CHANGES TO THE THINKING ON MONDAY AS UPPER LOW OVER THE SOUTHEAST CONUS WILL LIFT NORTH ALONG THE E COAST. ASSOCIATED MOIST...EASTERLY LL JET AND UPPER LVL DIVERGENCE PRECEDING THE UPPER LOW WILL LIKELY BRING SCT SHOWERS TO CENTRAL PA BEGINNING LATE TONIGHT ACROSS THE SOUTHEAST ZONES AND OVERSPREADING THE REST OF CENTRAL PA DURING MONDAY. CLOUD COVER...PRECIP AND EASTERLY FLOW OFF THE ATLANTIC WILL RESULT IN A MUCH COOLER MONDAY WITH MAX TEMPS ONLY ARND 70F. GEFS DATA SHOWING HIGHEST PWATS ACROSS SOUTHEAST PA...WHERE THE BEST CHC OF MEASURABLE RAINFALL IS EXPECTED SUN NITE/MONDAY. DOWNSLOPING SE FLOW WILL RESULT IN PARTIAL SUNSHINE AND A SOMEWHAT WARMER MONDAY OVR WARREN COUNTY...WHERE A LATE DAY TSRA IS POSSIBLE. CAPE VALUES IN THE 600 TO 800JK-1 RANGE ACROSS WARREN CO MON EVENING. FURTHER EAST...A COOLER MORE STABLE EASTERLY FLOW SHOULD PRECLUDE THUNDER. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... NOT A LOT OF CHANGE FROM THE FCST PACKAGE YESTERDAY. STILL LOOKS LIKE NORTHERN SYSTEM OFF THE COAST WILL PIVOT AROUND ALBERTO AND MOVE WESTWARD...BRINGING SHOWERS TO THE AREA ON TUE. MAIN CHC WILL BE MONDAY INTO TUE. DID UP TEMPS SOME ON TUE...ALSO SOME CHC OF A THUNDERSTORM WITH THE WARMER TEMPS. SHOWERS COULD LINGER INTO WED...ESPECIALLY ACROSS THE SE WITH THE FRONT. TRIED TO GO WITH THE MID SHIFT FCST AND HAVE SOME PERIODS OF DRY WEATHER. HARD TO FIND A LOT OF DRY PERIODS...AS REMAINS OF CUTOFF COULD KEEP A FEW SHOWERS ACROSS EASTERN AREAS...WHERE FAR NW AREAS COULD SEE SOME FROM THE COLD FRONT LATE IN THE WEEK. WENT WITH A DRY FCST FOR SUNDAY...IT WILL BE CLOSE...HARD TO SEE THE EAST...WEST COLD FRONT DROPPING TOO FAR SOUTH. TEMPS WILL BE WARM THROUGHOUT THE PERIOD...ABOVE NORMAL. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... VFR CONDITIONS PREVAIL ACROSS CENTRAL PENNSYLVANIA. MID CLOUDS STARTING TO STREAM INTO SOUTHERN TIER COUNTIES AND MAKING THEIR WAY INTO CENTRAL PA...WITH CIGS 050 TO 100. EASTERLY FLOW WILL PERSIST OVERNIGHT...AND BRING WITH IT A GRADUAL INCREASE CLOUDS SPREADING IN FROM THE SOUTHWEST. BY 06Z MVFR CIGS EXPECTED OVER KMDT AND KLNS...AND BY MONDAY MORNING /12Z/ EXPECT MVFR CIGS TO OVERSPREAD MUCH OF SOUTHEAST PENNSYLVANIA INTO THE LAURELS. MOISTURE WILL CONTINUE TO INCREASE ACROSS THE REGION ON SOUTHEAST LOW LEVEL FLOW...AS DEEP LOW LIFTS INTO THE REGION. MVFR TO IFR CIGS EXPECTED TO OVERSPREAD MOST OF CENTRAL PENNSYLVANIA BY 14-16Z...WITH INCREASING SHOWERS. EXCEPTION MAY BE FAR NW /KBFD/ WHERE VFR CONDITIONS MAY LINGER INTO LATER AFTERNOON. OUTLOOK... MON NIGHT-WED...WIDESPREAD MVFR/IFR CIGS AND VSBYS LIKELY IN SHOWERS AND SCT TSRA. THU...PRIMARILY VFR. SCT SHRA/TSTM POSS MAINLY SE. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...GRUMM/FITZGERALD NEAR TERM...FITZGERALD SHORT TERM...DEVOIR LONG TERM...MARTIN AVIATION...JUNG/DEVOIR
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
343 PM EDT MON MAY 21 2012 .SYNOPSIS... TROPICAL STORM ALBERTO WILL LINGER OFF THE CAROLINA COAST TONIGHT BEFORE BEGINNING TO PULL AWAY TO THE NORTHEAST ON TUESDAY. AN UPPER LEVEL LOW PRESSURE AND ASSOCIATED A COLD FRONT WILL MOVE THROUGH THE REGION ON TUESDAY. THE LOW PRESSURE WILL STEADILY LIFT NORTHEAST THROUGH MID WEEK...REPLACED BY BUILDING HIGH PRESSURE AND UNSEASONABLY WARM TEMPERATURES LATE THIS WEEK THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TUESDAY/... AT 130 PM...VISIBLE SATELLITE PICS SHOW SOME ENHANCED CUMULUS OVER THE MOUNTAINS AND RADAR SHOWS THAT SOME WIDELY SCATTERED SHOWERS HAVE DEVELOPED. EXPECT COVERAGE TO INCREASE TO SOLID SCATTERED COVERAGE BY MID AFTERNOON OVER THE MOUNTAINS. MESOSCALE MODELS LIKE THE HRRR STILL SUGGEST THAT SOME SCATTERED SHOWERS/THUNDERSTORMS WILL MOVE OUT INTO THE FOOTHILLS/PIEDMONT BY LATE AFTERNOON PROBABLY ALONG OUTFLOW BOUNDARIES. AT THE SAME TIME...A WEAK FRONT ALSO LOOKS LIKE IT WILL MOVE INTO THE MOUNTAINS BY LATE AFTENROON AND PERHAPS MERGE WITH THE OUTFLOW BOUDARIES SO THAT IT MOVES OUT INTO THE PIEDMONT DURING THE EVENING HOURS. HOWEVER...SURFACE CONVERGENCE WILL BE QUITE LIMITED SO EXPECT THAT CONVECTION WILL WANE WITH COOLING. CURRENT POP FIELD HANDLES THIS WELL. FOR THE OVERNIGHT...AN UPPER TROUGH WILL SLOWLY APPROACH FROM THE WEST BY LATE TONIGHT. FALLING HEIGHTS AND WEAK UPSLOPE SHOULD TRIGGER SCATTERED SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS LATE TONIGHT. USED A MOS BLEND FOR TEMPS. ON TUE...THE UPPER TROUGH IS FORECAST TO ONLY MOVE MARGINALLY EASTWARD WITH ITS AXIS PERHAPS REACHING THE MOUNTAINS LATE IN THE DAY. WEAK UPPER DIFFLUENCE AND THE STALLED SURFACE BOUNDARY SHOULD BE ENOUGH TO TRIGGER SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS TUE AFTERNOON. A GUIDANCE BLEND PUTS TEMPS NEAR AVERAGE. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... AS OF 230 PM MONDAY...MODELS ARE IN FAIR AGREEMENT SLOWING DOWN THE PROGRESSION OF THE UPPER TROF/LOW CENTER MOVG NE TUE NIGHT-WED BUT THE WEAK SFC FRONT SHOULD STILL MOVE SLOWLY E OF THE AREA BEFORE WASHING OUT DURING THE DAY WED. RETURNING LOW LVL S FLOW WILL BRING MOISTURE OVER THE REGION AND KEEP A CHC OF SCT SHWRS/TSTMS WED AFTN-EVE...ESP OVER THE MTNS IN AREAS OF BEST UPSLOPE. THE UPPER LOW MEANDERS OVER THE SE US WED NIGHT-THU WITH A SERIES OF WEAK UPPER DISTURBANCES ROTATING AROUND IT AND OVER THE AREA...WHILE ENOUGH LOW LVL MOISTURE REMAINS OVER THE CWA FOR A CONTINUING CHC OF SHWRS AND TSTMS THU...ESP OVER THE MTNS WITH AFTN HEATING. LOOK FOR TEMPS NEAR TO SLIGHTLY ABOVE AVG THRU THE PD. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AS OF 200 PM MONDAY...THE LATEST MODELS ARE IN GOOD AGREEMENT WITH THE STRONG UPPER LEVEL RIDGE OF HIGH PRESSURE BUILDING OVER THE EASTERN CONUS AND REMAIN PREDOMINANT LATE THURSDAY INTO SATURDAY. EXPECT UNSEASONABLY WARM TEMPERATURES AND MOSTLY DRY CONDITIONS ACROSS MUCH OF PIEDMONT/VALLEYS DURING THE PERIOD. HOWEVER...A COMBINATION OF UPSLOPE FLOW(SE TO E) AND DIURNAL INSTABILITY MAY SUPPORT THE DEVELOPMENT OF AFTERNOON ISOLATED/SCATTERED THUNDERSTORMS ALONG THE BLUE RIDGE MOUNTAINS EACH DAY. SO HAVE KEPT SLIGHT CHANCE POPS THERE WITH DRY ELSEWHERE. DAYTIME HIGHS OVER THE PIEDMONT WILL BE IN THE UPPER 80S THU/FRI AND WARMING INTO THE LOW 90S SATURDAY. SUNDAY AND MONDAY...CONFIDENCE IS LOW AS THE MODELS SHOW DIFFERENT SOLUTIONS. THE CANADIAN MODEL SHOWS A CUT OFF LOW FORMING OFF THE NORTH CAROLINA COAST BY EARLY SUNDAY AND LINGERS INTO MONDAY WHILE THE GFS AND THE ECMWF SUGGEST A TROPICAL WAVE OVER THE ATLANTIC OCEAN MOVING WEST INTO THE GA/SC COAST BY SUNDAY. DUE TO THE TROPICAL MOISTURE INFLUX FROM THE SE AND DIURNAL INSTABILITY...WILL CARRY SLIGHT CHANCE POPS ACROSS MUCH OF OUR CWA. DAYTIME HIGHS WILL REMAIN 5-10 DEGREES ABOVE NORMALS SUN/MON. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... AT KCLT...MAIN QUESTION FPR THE NEAR TERM IS WHETHER ANY CONVECTION WILL AFFECT THE AIRFIELD LATE THIS AFTERNOON INTO EARLY EVENING. THE HRRR SUGGESTS THAT THERE WILL BE SCATTERED CONVECTION IN THE VICINITY OF THE AIRFIELD CIRCA 00Z. FOR NOW WILL JUST HAVE A VCSH FROM 00Z-02Z. FOR THE OVERNIGHT JUST A MID LEVEL CEILING IS EXPECTED WITH PERHAPS SOME LIGHT FOG AROUND DAYBREAK RESTRICTING THE VSBY TO AROUND 5SM. LOOKS LIKE TUE`S CONVECTION SHOULD HOLD OFF UNTIL AFTER THE END OF THIS TAF PERIOD. ELSEWHERE...SCT TO NUMEROUS SHOWERS/THUNDERSTORMS ARE FORECAST TO DEVELOP OVER THE MOUNTAINS BY 20Z. WILL CARRY A TEMPO AT KAVL FOR THUNDER AND MVFR RESTRICTIONS FROM 20-22Z. MESOSCALE MODELS SUGGEST THAT CONVECTION WILL MOVE INTO THE FOOTHILLS/PIEDMONT LATE THIS AFTERNOON AND EVENING. HENCE...WUILL CARRY A VCTS AT KHKY AND KGSP. THE PREPONDERANCE OF GUIDANCE IS FORCASTING AT LEAST MVFR VSBY RESTRICTIONS IN FOG AROUND DAYBREAK TUE...WITH IFR POSSIBLE AT KAVL. CONVECTION WILL GET AN EARLY START ON TUE WITH A CHANCE OF THUNDER AT KAVL BY 18Z. OUTLOOK...SHOWER AND TSTM CHANCES WILL DIMINSH DIURNALLY TUE NIGHT BUT RE-DEVELOP AGAIN WED AFTERNOON MOST AREAS. DIURNAL THUNDERSTORMS TOWARD THE END OF THE WEEK WILL BE MORE LIKELY CONFINED TO THE MOUNTAINS AND FOOTHILLS. EARLY MORNING RESTRICTIONS DUE TO FOG ARE A GOOD BET MAINLY IN THE MOUNTAIN VALLEYS EACH MORNING. AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)... WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...JOH NEAR TERM...LG SHORT TERM...RB LONG TERM...JOH AVIATION...LG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
239 PM EDT MON MAY 21 2012 .SYNOPSIS... TROPICAL STORM ALBERTO WILL LINGER OFF THE CAROLINA COAST TONIGHT BEFORE BEGINNING TO PULL AWAY TO THE NORTHEAST ON TUESDAY. AN UPPER LEVEL LOW PRESSURE AND ASSOCIATED A COLD FRONT WILL MOVE THROUGH THE REGION ON TUESDAY. THE LOW PRESSURE WILL STEADILY LIFT NORTHEAST THROUGH MID WEEK...REPLACED BY BUILDING HIGH PRESSURE AND UNSEASONABLY WARM TEMPERATURES LATE THIS WEEK THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TUESDAY/... AT 130 PM...VISIBLE SATELLITE PICS SHOW SOME ENHANCED CUMULUS OVER THE MOUNTAINS AND RADAR SHOWS THAT SOME WIDELY SCATTERED SHOWERS HAVE DEVELOPED. EXPECT COVERAGE TO INCREASE TO SOLID SCATTERED COVERAGE BY MID AFTERNOON OVER THE MOUNTAINS. MESOSCALE MODELS LIKE THE HRRR STILL SUGGEST THAT SOME SCATTERED SHOWERS/THUNDERSTORMS WILL MOVE OUT INTO THE FOOTHILLS/PIEDMONT BY LATE AFTERNOON PROBABLY ALONG OUTFLOW BOUNDARIES. AT THE SAME TIME...A WEAK FRONT ALSO LOOKS LIKE IT WILL MOVE INTO THE MOUNTAINS BY LATE AFTENROON AND PERHAPS MERGE WITH THE OUTFLOW BOUDARIES SO THAT IT MOVES OUT INTO THE PIEDMONT DURING THE EVENING HOURS. HOWEVER...SURFACE CONVERGENCE WILL BE QUITE LIMITED SO EXPECT THAT CONVECTION WILL WANE WITH COOLING. CURRENT POP FIELD HANDLES THIS WELL. FOR THE OVERNIGHT...AN UPPER TROUGH WILL SLOWLY APPROACH FROM THE WEST BY LATE TONIGHT. FALLING HEIGHTS AND WEAK UPSLOPE SHOULD TRIGGER SCATTERED SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS LATE TONIGHT. USED A MOS BLEND FOR TEMPS. ON TUE...THE UPPER TROUGH IS FORECAST TO ONLY MOVE MARGINALLY EASTWARD WITH ITS AXIS PERHAPS REACHING THE MOUNTAINS LATE IN THE DAY. WEAK UPPER DIFFLUENCE AND THE STALLED SURFACE BOUNDARY SHOULD BE ENOUGH TO TRIGGER SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS TUE AFTERNOON. A GUIDANCE BLEND PUTS TEMPS NEAR AVERAGE. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... AS OF 230 PM MONDAY...MODELS ARE IN FAIR AGREEMENT SLOWING DOWN THE PROGRESSION OF THE UPPER TROF/LOW CENTER MOVG NE TUE NIGHT-WED BUT THE WEAK SFC FRONT SHOULD STILL MOVE SLOWLY E OF THE AREA BEFORE WASHING OUT DURING THE DAY WED. RETURNING LOW LVL S FLOW WILL BRING MOISTURE OVER THE REGION AND KEEP A CHC OF SCT SHWRS/TSTMS WED AFTN-EVE...ESP OVER THE MTNS IN AREAS OF BEST UPSLOPE. THE UPPER LOW MEANDERS OVER THE SE US WED NIGHT-THU WITH A SERIES OF WEAK UPPER DISTURBANCES ROTATING AROUND IT AND OVER THE AREA...WHILE ENOUGH LOW LVL MOISTURE REMAINS OVER THE CWA FOR A CONTINUING CHC OF SHWRS AND TSTMS THU...ESP OVER THE MTNS WITH AFTN HEATING. LOOK FOR TEMPS NEAR TO SLIGHTLY ABOVE AVG THRU THE PD. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... AS OF 200 PM MONDAY...THE LATEST MODELS ARE IN GOOD AGREEMENT WITH THE STRONG UPPER LEVEL RIDGE OF HIGH PRESSURE BUILDING OVER THE EASTERN CONUS AND REMAIN PREDOMINANT LATE THURSDAY INTO SATURDAY. EXPECT UNSEASONABLY WARM TEMPERATURES AND MOSTLY DRY CONDITIONS ACROSS MUCH OF PIEDMONT/VALLEYS DURING THE PERIOD. HOWEVER...A COMBINATION OF UPSLOPE FLOW(SE TO E) AND DIURNAL INSTABILITY MAY SUPPORT THE DEVELOPMENT OF AFTERNOON ISOLATED/SCATTERED THUNDERSTORMS ALONG THE BLUE RIDGE MOUNTAINS EACH DAY. SO HAVE KEPT SLIGHT CHANCE POPS THERE WITH DRY ELSEWHERE. DAYTIME HIGHS OVER THE PIEDMONT WILL BE IN THE UPPER 80S THU/FRI AND WARMING INTO THE LOW 90S SATURDAY. SUNDAY AND MONDAY...CONFIDENCE IS LOW AS THE MODELS SHOW DIFFERENT SOLUTIONS. THE CANADIAN MODEL SHOWS A CUT OFF LOW FORMING OFF THE NORTH CAROLINA COAST BY EARLY SUNDAY AND LINGERS INTO MONDAY WHILE THE GFS AND THE ECMWF SUGGEST A TROPICAL WAVE OVER THE ATLANTIC OCEAN MOVING WEST INTO THE GA/SC COAST BY SUNDAY. WITH THAT SAID...HAVE KEPT SLIGHT CHANCE POPS OVER MUCH OF OUR CWA DURING THE PERIOD. && .AVIATION /19Z MONDAY THROUGH SATURDAY/... AT KCLT...MAIN QUESTION FPR THE NEAR TERM IS WHETHER ANY CONVECTION WILL AFFECT THE AIRFIELD LATE THIS AFTERNOON INTO EARLY EVENING. THE HRRR SUGGESTS THAT THERE WILL BE SCATTERED CONVECTION IN THE VICINITY OF THE AIRFIELD CIRCA 00Z. FOR NOW WILL JUST HAVE A VCSH FROM 00Z-02Z. FOR THE OVERNIGHT JUST A MID LEVEL CEILING IS EXPECTED WITH PERHAPS SOME LIGHT FOG AROUND DAYBREAK RESTRICTING THE VSBY TO AROUND 5SM. LOOKS LIKE TUE`S CONVECTION SHOULD HOLD OFF UNTIL AFTER THE END OF THIS TAF PERIOD. ELSEWHERE...SCT TO NUMEROUS SHOWERS/THUNDERSTORMS ARE FORECAST TO DEVELOP OVER THE MOUNTAINS BY 20Z. WILL CARRY A TEMPO AT KAVL FOR THUNDER AND MVFR RESTRICTIONS FROM 20-22Z. MESOSCALE MODELS SUGGEST THAT CONVECTION WILL MOVE INTO THE FOOTHILLS/PIEDMONT LATE THIS AFTERNOON AND EVENING. HENCE...WUILL CARRY A VCTS AT KHKY AND KGSP. THE PREPONDERANCE OF GUIDANCE IS FORCASTING AT LEAST MVFR VSBY RESTRICTIONS IN FOG AROUND DAYBREAK TUE...WITH IFR POSSIBLE AT KAVL. CONVECTION WILL GET AN EARLY START ON TUE WITH A CHANCE OF THUNDER AT KAVL BY 18Z. OUTLOOK...SHOWER AND TSTM CHANCES WILL DIMINSH DIURNALLY TUE NIGHT BUT RE-DEVELOP AGAIN WED AFTERNOON MOST AREAS. DIURNAL THUNDERSTORMS TOWARD THE END OF THE WEEK WILL BE MORE LIKELY CONFINED TO THE MOUNTAINS AND FOOTHILLS. EARLY MORNING RESTRICTIONS DUE TO FOG ARE A GOOD BET MAINLY IN THE MOUNTAIN VALLEYS EACH MORNING. AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)... WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...JOH NEAR TERM...LG SHORT TERM...RB LONG TERM...JOH AVIATION...LG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
146 PM EDT MON MAY 21 2012 .SYNOPSIS... TROPICAL STORM ALBERTO WILL LINGER OFF THE CAROLINA COAST TONIGHT BEFORE BEGINNING TO PULL AWAY TO THE NORTHEAST ON TUESDAY. AN UPPER LEVEL LOW PRESSURE AND ASSOCIATED A COLD FRONT WILL MOVE THROUGH THE REGION ON TUESDAY. THE LOW PRESSURE WILL STEADILY LIFT NORTHEAST THROUGH MID WEEK...REPLACED BY BUILDING HIGH PRESSURE AND UNSEASONABLY WARM TEMPERATURES LATE THIS WEEK THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TUESDAY/... AT 130 PM...VISIBLE SATELLITE PICS SHOW SOME ENHANCED CUMULUS OVER THE MOUNTAINS AND RADAR SHOWS THAT SOME WIDELY SCATTERED SHOWERS HAVE DEVELOPED. EXPECT COVERAGE TO INCREASE TO SOLID SCATTERED COVERAGE BY MID AFTERNOON OVER THE MOUNTAINS. MESOSCALE MODELS LIKE THE HRRR STILL SUGGEST THAT SOME SCATTERED SHOWERS/THUNDERSTORMS WILL MOVE OUT INTO THE FOOTHILLS/PIEDMONT BY LATE AFTERNOON PROBABLY ALONG OUTFLOW BOUNDARIES. AT THE SAME TIME...A WEAK FRONT ALSO LOOKS LIKE IT WILL MOVE INTO THE MOUNTAINS BY LATE AFTENROON AND PERHAPS MERGE WITH THE OUTFLOW BOUDARIES SO THAT IT MOVES OUT INTO THE PIEDMONT DURING THE EVENING HOURS. HOWEVER...SURFACE CONVERGENCE WILL BE QUITE LIMITED SO EXPECT THAT CONVECTION WILL WANE WITH COOLING. CURRENT POP FIELD HANDLES THIS WELL. FOR THE OVERNIGHT...AN UPPER TROUGH WILL SLOWLY APPROACH FROM THE WEST BY LATE TONIGHT. FALLING HEIGHTS AND WEAK UPSLOPE SHOULD TRIGGER SCATTERED SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS LATE TONIGHT. USED A MOS BLEND FOR TEMPS. ON TUE...THE UPPER TROUGH IS FORECAST TO ONLY MOVE MARGINALLY EASTWARD WITH ITS AXIS PERHAPS REACHING THE MOUNTAINS LATE IN THE DAY. WEAK UPPER DIFFLUENCE AND THE STALLED SURFACE BOUNDARY SHOULD BE ENOUGH TO TRIGGER SCATTER TO NUMEROUS SHOWERS AND THUNDERSTORMS TUE AFTERNOON. A GUIDANCE BLEND PUTS TEMPS NEAR AVERAGE. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... AS OF 300 AM EDT MONDAY...FAIRLY GOOD MODEL CONSENSUS EXISTS THAT A DIGGING TROUGH WILL CLOSE OFF AN UPPER LEVEL LOW PRESSURE CENTER IN OR NEAR THE SOUTHERN APPALCHIANS TUESDAY. AN ASSOCIATED SFC COLD FRONT WILL MOVE INTO THE AREA FROM THE WEST ON TUESDAY AS WELL...BUT WITH THE CONTRAST ALONG THE BOUNDARY SLOWLY BEING LOST THROUGH THE DAY. NUMEROUS MTN TO SCATTERED PIEDMONT CONVECTIVE COVERAGE EARLY SHOULD STEADILY INCREASE TO NUMEROUS COVERAGE THROUGHOUT DURING THE AFTN AND EARLY EVENING HOURS. MODEL PROFILES SUGGEST THAT WINDS WILL BE FAIRLY LIGHT UP THE COLUMN WITH THE PASSAGE OF THE BEST UPPER SUPPORT. LAPSE RATES WILL STEEPEN A BIT...BUT WITH THE COLDEST POOL OF 500 MB TEMPS ALOFT PASSING BY JUST SE OF THE AREA. THE SEVERE WEATHER POTENTIAL...THEREFORE...IS NOT TERRIBLY IMPRESSIVE. THE UPPER LOW CENTER WILL LIFT SLOWLY NORTHEASTWARD TUE NIGHT THROUGH WED AND GRADUALLY FILL. LOW LEVEL FLOW WILL RETURN TO SOUTHERLY AND BOUNDARY LAYER MOISTURE SHOULD LINGER ENOUGH TO PERMIT SCATTERED CONVECTIVE COVERAGE TO RETURN WED AFTN AND EVENING. TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY ABOVE NORMAL THROUGH THE PERIOD. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 300 AM EDT MONDAY...AS THE FILLING LOW PRES SYSTEM PULLS AWAY TO THE NE ON THU...LOW LEVEL SW FLOW WILL PERSIST ACROSS THE REGION AND HEIGHTS WILL START RISING ALOFT. TEMPERATURES SHOULD WARM INTO THE MID 80S MOST LOCATIONS OUTSIDE OF THE MTNS THU AFTN...WITH SOME LOWER 80S IN THE LOWER MTN VALLEYS. ISOLATED...MAINLY MTN...DIURNAL POPS ARE INDICATED IN THE WARM AIRMASS. DOMINANT RIDGING WILL THEN START BUILDING OVER THE ERN CONUS ON FRI...WITH TEMPERATURES GAINING ANOTHER CATEGORY BY FRIDAY AFTN. VERY LITTLE CAPE IS EVIDENT IN THE WARM PROFILES ALOFT...BUT LINGERING BL MOISTURE WILL WARRANT A SLIGHT CHC TSTM MENTION ALONG THE HIGHER TERRAIN FRI AFTN/EVENING. STRONG HIGH PRESSURE WILL COME TO DOMINATE THE ENTIRE ERN CONUS BY SAT...WITH MAXES AS MUCH AS 10 DEGREES ABOVE NORMAL. ISOLD TO SCT RIDGE TOP CONVECTION WILL ONCE AGAIN BE POSSIBLE LATE IN THE DAY. 850 MB TEMPS MAY THEN COOL VERY SLIGHTLY ON SUNDAY AS THE RIDGE RETROGRADES WEST...BUT TEMPS WILL STAY WELL ABOVE AVERAGE. ANOTHER ROUND OF ISOLATED DIURNALLY DRIVEN MOUNTAIN CONVECTION WILL BE POSSIBLE UNDER THE RIDGE SUNDAY AFTN. CONVECTIVE INITIATION MAY FOCUS SLIGHTLY MORE TOWARD THE ERN SLOPES IF AN EASTERLY COMPONENT IN THE BOUNDARY LAYER FLOW DEVELOPS UNDER THE RIDGE AS EXPECTED. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AT KCLT...MAIN QUESTION FPR THE NEAR TERM IS WHETHER ANY CONVECTION WILL AFFECT THE AIRFIELD LATE THIS AFTERNOON INTO EARLY EVENING. THE HRRR SUGGESTS THAT THERE WILL BE SCATTERED CONVECTION IN THE VICINITY OF THE AIRFIELD CIRCA 00Z. FOR NOW WILL JUST HAVE A VCSH FROM 00Z-02Z. FOR THE OVERNIGHT JUST A MID LEVEL CEILING IS EXPECTED WITH PERHAPS SOME LIGHT FOG AROUND DAYBREAK RESTRICTING THE VSBY TO AROUND 5SM. LOOKS LIKE TUE`S CONVECTION SHOULD HOLD OFF UNTIL AFTER THE END OF THIS TAF PERIOD. ELSEWHERE...SCT TO NUMEROUS SHOWERS/THUNDERSTORMS ARE FORECAST TO DEVELOP OVER THE MOUNTAINS BY 20Z. WILL CARRY A TEMPO AT KAVL FOR THUNDER AND MVFR RESTRICTIONS FROM 20-22Z. MESOSCALE MODELS SUGGEST THAT CONVECTION WILL MOVE INTO THE FOOTHILLS/PIEDMONT LATE THIS AFTERNOON AND EVENING. HENCE...WUILL CARRY A VCTS AT KHKY AND KGSP. THE PREPONDERANCE OF GUIDANCE IS FORCASTING AT LEAST MVFR VSBY RESTRICTIONS IN FOG AROUND DAYBREAK TUE...WITH IFR POSSIBLE AT KAVL. CONVECTION WILL GET AN EARLY START ON TUE WITH A CHANCE OF THUNDER AT KAVL BY 18Z. OUTLOOK...SHOWER AND TSTM CHANCES WILL DIMINSH DIURNALLY TUE NIGHT BUT RE-DEVELOP AGAIN WED AFTERNOON MOST AREAS. DIURNAL THUNDERSTORMS TOWARD THE END OF THE WEEK WILL BE MORE LIKELY CONFINED TO THE MOUNTAINS AND FOOTHILLS. EARLY MORNING RESTRICTIONS DUE TO FOG ARE A GOOD BET MAINLY IN THE MOUNTAIN VALLEYS EACH MORNING. AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)... WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...JOH NEAR TERM...LG SHORT TERM...HG LONG TERM...HG AVIATION...LG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1034 AM EDT MON MAY 21 2012 .SYNOPSIS... TROPICAL STORM ALBERTO WILL LINGER OFF THE CAROLINA COAST TODAY BEFORE BEGINNING TO PULL AWAY TO THE NORTHEAST ON TUESDAY. A COLD FRONT AND AN UPPER LEVEL LOW PRESSURE SYSTEM WILL MOVE INTO THE AREA FROM THE WEST TONIGHT THROUGH TUESDAY. THE LOW PRESSURE WILL STEADILY LIFT NORTHEAST THROUGH MID WEEK...REPLACED BY BUILDING HIGH PRESSURE AND UNSEASONABLY WARM TEMPERATURES LATE THIS WEEK THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AT 1030 AM...VISIBLE SATELLITE PICS INDICATE MAINLY CLEAR CONDITIONS OUTSIDE OF THE MOUNTAINS WITH SCATTERED CLOUDS OVER THE MOUNTAINS. WITH AMPLE INSOLATION THIS MORNING...SO NO REASON TO DISCOUNT MESOSCALE MODELS LIKE THE HRRR AND LOCAL WRF`S THAT DEVELOP SCATTERED THUDNERSTORMS OVER THE MOUNTAINS EARLY IN THE AFTERNOON...WITH SOME STORMS SPILLING OUT INTO THE PIEDMONT LATE AFTERNOON INTO THE EVENING. MADE SOME MOSTLY MINOR ADJUSTMENTS TO POP/SKY/THERMAL FIELDS FOR TODAY. FORECAST SOUNDINGS DEPICT A VERY DEEP MIXED LAYER/STRONG LOW-MID LEVEL LAPSE RATES THIS AFTERNOON ACROSS THE MTNS. THIS SHOULD YIELD CAPES IN EXCESS OF 1500 J/KG ACROSS THE HIGHER TERRAIN. FREEZING LEVELS SHOULD BE LOW ENOUGH AND DCAPE SUFFICIENTLY ADEQUATE TO PERHAPS SUPPORT A FEW PULSE SEVERE STORMS. ADJUSTED POPS OVERNIGHT BASED ON 12Z NAM WHICH ALLOWS CONVECTION TO END OVER THE PIEDMONT WITH NEW DEVELOPMENT OVER THE MOUNTAINS LATE TONIGHT AS UPPER TROUGH APPROACHES. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM EDT MONDAY...FAIRLY GOOD MODEL CONSENSUS EXISTS THAT A DIGGING TROUGH WILL CLOSE OFF AN UPPER LEVEL LOW PRESSURE CENTER IN OR NEAR THE SOUTHERN APPALCHIANS TUESDAY. AN ASSOCIATED SFC COLD FRONT WILL MOVE INTO THE AREA FROM THE WEST ON TUESDAY AS WELL...BUT WITH THE CONTRAST ALONG THE BOUNDARY SLOWLY BEING LOST THROUGH THE DAY. NUMEROUS MTN TO SCATTERED PIEDMONT CONVECTIVE COVERAGE EARLY SHOULD STEADILY INCREASE TO NUMEROUS COVERAGE THROUGHOUT DURING THE AFTN AND EARLY EVENING HOURS. MODEL PROFILES SUGGEST THAT WINDS WILL BE FAIRLY LIGHT UP THE COLUMN WITH THE PASSAGE OF THE BEST UPPER SUPPORT. LAPSE RATES WILL STEEPEN A BIT...BUT WITH THE COLDEST POOL OF 500 MB TEMPS ALOFT PASSING BY JUST SE OF THE AREA. THE SEVERE WEATHER POTENTIAL...THEREFORE...IS NOT TERRIBLY IMPRESSIVE. THE UPPER LOW CENTER WILL LIFT SLOWLY NORTHEASTWARD TUE NIGHT THROUGH WED AND GRADUALLY FILL. LOW LEVEL FLOW WILL RETURN TO SOUTHERLY AND BOUNDARY LAYER MOISTURE SHOULD LINGER ENOUGH TO PERMIT SCATTERED CONVECTIVE COVERAGE TO RETURN WED AFTN AND EVENING. TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY ABOVE NORMAL THROUGH THE PERIOD. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 300 AM EDT MONDAY...AS THE FILLING LOW PRES SYSTEM PULLS AWAY TO THE NE ON THU...LOW LEVEL SW FLOW WILL PERSIST ACROSS THE REGION AND HEIGHTS WILL START RISING ALOFT. TEMPERATURES SHOULD WARM INTO THE MID 80S MOST LOCATIONS OUTSIDE OF THE MTNS THU AFTN...WITH SOME LOWER 80S IN THE LOWER MTN VALLEYS. ISOLATED...MAINLY MTN...DIURNAL POPS ARE INDICATED IN THE WARM AIRMASS. DOMINANT RIDGING WILL THEN START BUILDING OVER THE ERN CONUS ON FRI...WITH TEMPERATURES GAINING ANOTHER CATEGORY BY FRIDAY AFTN. VERY LITTLE CAPE IS EVIDENT IN THE WARM PROFILES ALOFT...BUT LINGERING BL MOISTURE WILL WARRANT A SLIGHT CHC TSTM MENTION ALONG THE HIGHER TERRAIN FRI AFTN/EVENING. STRONG HIGH PRESSURE WILL COME TO DOMINATE THE ENTIRE ERN CONUS BY SAT...WITH MAXES AS MUCH AS 10 DEGREES ABOVE NORMAL. ISOLD TO SCT RIDGE TOP CONVECTION WILL ONCE AGAIN BE POSSIBLE LATE IN THE DAY. 850 MB TEMPS MAY THEN COOL VERY SLIGHTLY ON SUNDAY AS THE RIDGE RETROGRADES WEST...BUT TEMPS WILL STAY WELL ABOVE AVERAGE. ANOTHER ROUND OF ISOLATED DIURNALLY DRIVEN MOUNTAIN CONVECTION WILL BE POSSIBLE UNDER THE RIDGE SUNDAY AFTN. CONVECTIVE INITIATION MAY FOCUS SLIGHTLY MORE TOWARD THE ERN SLOPES IF AN EASTERLY COMPONENT IN THE BOUNDARY LAYER FLOW DEVELOPS UNDER THE RIDGE AS EXPECTED. && .AVIATION /15Z MONDAY THROUGH FRIDAY/... AT KCLT AND ELSEWHERE...MVFR STRATOCU OVER CENTRAL NC MAY MAKE A RUN AT KCLT THIS MORNING...BUT CONFIDENCE IS LOW THAT THIS WILL OCCUR... AND IT SHOULD BE BRIEF IF IT DOES OCCUR. OTHERWISE...ALL TERMINALS WILL SEE VFR CONDITIONS THROUGH AT LEAST THIS EVENING...BARRING ANY CONVECTIVE OCCURRENCE. SPEAKING OF WHICH...SCATTERED CONVECTION WILL DEVELOP OVER THE MOUNTAINS THIS AFTERNOON...AND A TEMPO WILL BE INCLUDED AT KAVL EARLY THIS AFTERNOON...FOLLOWED BY A PROB30 FOR THE REMAINDER OF THE AFTERNOON AND EARLY EVENING. ISOLATED TO WIDELY SCATTERED CONVECTION MAY EXTEND INTO THE PIEDMONT AND FOOTHILLS LATE THIS AFTERNOON AND EVENING. A PROB 30 WILL BE CARRIED AT KHKY TO ACCOUNT FOR THIS. ANY FOG/CIG RESTRICTIONS LATE TONIGHT WILL DEPEND LARGELY UPON RAIN OCCURRENCE AT THE TERMINALS THIS AFTERNOON/ EVENING. OTHER THAN MVFR FOG AT KAVL...RESTRICTIONS WILL BE WITHHELD FROM THE FORECASTS ATTM. OUTLOOK...DIURNAL SHOWER AND TSTM CHANCES WILL INCREASE TUESDAY AS A WEAK COLD FRONT ARRIVES FROM THE WEST. AN UPPER LOW IS EXPECTED TO DEVELOP OVER THE CAROLINAS BY MID-WEEK...AND THIS WILL KEEP CHANCES FOR AT LEAST ISOLATED SHOWERS AND THUNDERSTORMS IN THE FORECAST FOR MOST AFTERNOONS/EVENING THROUGH THE WEEK. AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)... WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...HG NEAR TERM...LG SHORT TERM...HG LONG TERM...HG AVIATION...JDL
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
902 PM CDT TUE MAY 22 2012 .DISCUSSION.../ISSUED AT 900 PM CDT/ MAIN ISSUE OVER THE NEXT 18 HOURS IS THE CONVECTIVE CHANCES WITH THE SURFACE COLD FRONT. CURRENTLY A BROKEN LINE OF CONVECTION EXTENDS FROM NEAR ABERDEEN TO WINNER SOUTH DAKOTA. WHILE STORMS INITIALLY DEVELOPED ALONG THE SURFACE FRONT...THE STRONG LOW LEVEL WINDS HAVE RESULTED IN STORM MOTIONS THAT MOVE THEM AWAY FROM THE BOUNDARY. AS A RESULT...UPDRAFTS CONTINUE TO WEAKEN ONCE THE STORMS MOVE INTO THE MORE STABLE AIR MASS OVER SOUTHEAST SOUTH DAKOTA. WITH LITTLE UPPER LEVEL FORCING FOR ASCENT IN THE NEXT HOUR OR TWO...SEVERE WEATHER APPEARS UNLIKELY ALTHOUGH WITH 60 KT WINDS AT 850 MB...A SEVERE WIND GUST OR QUARTER SIZE HAIL MAY STILL BE POSSIBLE. EXPECTATION IS THESE STORMS WILL LIKELY SLOWLY WEAKEN OVER NEXT 3 OR 4 HOURS...ESPECIALLY SOUTH OF I-90 WHERE LOSS OF SURFACE HEATING WILL ONLY STRENGTHEN CAP. HOWEVER...BOTH RAP AND NAM SHOW ANOTHER WEAK WAVE WITH ASSOCIATED COOLING AT MID LEVELS MOVING INTO CENTRAL SD AROUND 09Z. THESE MODELS ALONG WITH HRRR ALL PRODUCE MORE CONVECTION AHEAD THE SURFACE COLD FRONT WHICH IS EXPECTED TO BE BETWEEN 9V9 AND MHE. WITH THE COLD ADVECTION AND WEAK MIDLEVEL ASCENT...THIS IS EXPECTED TO BE ENOUGH TO ERODE THE CAP AHEAD OF THE LATER TONIGHT. AM A LITTLE CONCERNED THAT MODELS MAY BE OVERDOING THE DEGREE OF COOLING ABOVE THE INVERSION AND CONVECTION WILL BE A LITTLE LESS WIDESPREAD THAN MODELS ARE SHOWING...ESPECIALLY SOUTH OF I90. BECAUSE THIS SECOND WAVE IS LATER IN THE NIGHT...HAVE SLOWED THE PROGRESSION OF PRECIPITATION OVERNIGHT INTO WEDNESDAY MORNING WITH THE BEST CHANCE FOR STORMS REMAINING OVER EAST CENTRAL SD THROUGH 12Z AND THEN IN SW MN THROUGH 15Z OR 18Z. ALSO RAISED POPS ALONG AND NORTH I90 LATE TONIGHT TO 30 TO 50 PERCENT RANGE. FINALLY...HAVE INCREASED QPF OVERNIGHT TO AN AVERAGE OF 0.1 TO 0.2 ALONG HWY 14 ALTHOUGH LOCAL AMOUNTS APPROACHING 0.5 IN ARE POSSIBLE WITH STORMS...AROUND BKX AND MML. MADE FEW CHANGES TO TEMPERATURES OR WIND BUT DID INCREASE SKY COVER THIS EVENING. LATEST GRID/ZFP AND PFM ALREADY ISSUED. && .AVIATION.../FOR THE 00Z TAF ISSUANCE/ MAINLY VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. STRONG SOUTHERLY WIND GUSTS AROUND 30-35KTS EXPECTED TO PERSIST THROUGH EARLY PART OF TAF PERIOD...THOUGH EVEN AFTER 03Z GUSTS AROUND 25KT WILL REMAIN LIKELY UNTIL COLD FRONT APPROACHES FROM THE WEST LATER TONIGHT...ALLOWING FOR WEAKENING SURFACE GRADIENT/FURTHER DECREASE IN WINDS. MODELS CONTINUE TO SHOW 50-60KT LOW LEVEL JET ABOVE 1500FT AGL...LEADING TO CONCERNS OF LOW LEVEL WIND SHEAR. ALTHOUGH WINDS REMAIN SOMEWHAT GUSTY AT THE SURFACE...WITH LOW LEVEL JET OF THIS MAGNITUDE AND DIRECTION SLIGHTLY VEERED FROM DOMINANT SURFACE WIND DIRECTION...WILL CONTINUE MENTION OF LLWS FOR ALL TAF LOCATIONS TONIGHT. CONFIDENCE IN ELEVATED THUNDERSTORMS AFFECTING TAF SITES OVERNIGHT IS WANING...AS UPPER LEVEL SUPPORT SEEMS TO FOCUS MORE TO THE NORTH OF THIS AREA. WILL HANG ONTO A SMALL WINDOW OF POSSIBLE TSRA FOR KHON 06Z-08Z AS SECONDARY MID LEVEL WAVE MOVES INTO THE AREA. OTHERWISE KEEPING THE TAFS FREE OF PRECIPITATION THROUGH WEDNESDAY. CHANCES WILL INCREASE LATE IN THE PERIOD ALONG AND EAST OF I-29 CORRIDOR AS COLD FRONT PUSHES SLOWLY EAST. HOWEVER...THINK CAPPING INVERSION AHEAD OF THE COLD FRONT COULD SUPPRESS CONVECTION UNTIL AFTER THE END OF THIS TAF PERIOD AND OPTED TO LEAVE POTENTIAL LATE AFTERNOON TSRA OUT OF THIS ISSUANCE. && .PREV DISCUSSION.../ISSUED AT 330 PM CDT/ STRONG SOUTHERLY FLOW CONTINUES ACROSS THE AREA AHEAD OF A COLD FRONT THAT HAS PUSHED INTO FAR NORTHWEST CORNER OF SOUTH DAKOTA. WITH GRADIENT CONTINUING TO STRENGTHEN ALOFT...WILL CONTINUE WIND ADVISORY ACROSS THE AREA THROUGH THE EVENING HOURS AS THE FRONT WORKS EAST THIS EVENING...COULD SEE THUNDERSTORMS DEVELOP BUT EXPECT THE FOCUS TO BE FURTHER NORTH CLOSER TO THE MID LEVEL WAVE. AS SUCH...HAVE NOT MADE MANY ADJUSTMENTS TO POPS WITH FOCUS MAINLY NORTH OF I-90. WITH STOUT WINDS CONTINUING AHEAD OF THE FRONT...KEPT FORECAST LOWS QUITE MILD CLOSER TO CONS RAW AND W MODEL. BOUNDARY IS EXPECTED TO ENTER THE FORECAST AREA AFTER 06Z WEDNESDAY AND SLOWLY PUSH EAST. NOT A LOT IN TERMS OF UPPER LEVEL SUPPORT UNTIL WEDNESDAY EVENING AS UPPER WAVE LIFTS INTO THE REGION...AND WEAK CAPPING INVERSION LOOKS TO HOLD FOR THE BETTER PART OF THE DAY. KEPT CHANCE POPS GOING IN THE VICINITY OF THE FRONT THROUGH THE DAY...BUT FOCUS WILL CERTAINLY BE WEDNESDAY NIGHT. HIGHS WILL GENERALLY BE IN THE 70S TO LOWER 80S WITH 850 HPA TEMPS IN THE MID TEENS. CONTINUES TO LOOK LIKE A POTENTIAL HEAVY RAIN EVENT WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING AS FRONT STALLS ACROSS FAR SOUTHEAST CWA WEDNESDAY NIGHT INTO THURSDAY MORNING WHILE WAVE EJECTS NORTHEAST OUT OF NEBRASKA. INITIALLY COULD SEE SOME SEVERE WEATHER DURING THE EVENING ACROSS NORTHWEST IOWA...BUT MAIN CONCERN WOULD BE THE HEAVY RAINS. MODELS DO DIFFER ON PLACEMENT WITH GFS AND EC A LITTLE FURTHER SOUTH THAN NAM/GEM. PREFER THE GFS/EC SOLUTION WITH BEST CHANCE CLOSER TO FRONT WHERE DEEP MOISTURE WILL POOL AND WHERE HIGHEST PWATS NEAR 1.50 INCHES EXPECTED. SO ACTIVITY THAT DEVELOPS IN THE AFTERNOON SHOULD REALLY GET GOING WEDNESDAY EVENING AND PERSIST THROUGH THE NIGHT WITH LOCAL RAINFALL AMOUNTS OVER 3 INCHES LIKELY ESPECIALLY NEAR THE FRONT AND THEN DROPPING OFF DRAMATICALLY ACROSS FAR NORTHWEST CWA. SO HIGHEST POPS WILL BE ACROSS SOUTHEAST CWA WEDNESDAY NIGHT INTO THURSDAY MORNING...AND THEN A LINGERING SMALLER CHANCE THURSDAY AFTERNOON IN EARLY EVENING. WILL HOLD OFF ANY FLOOD WATCH FOR WEDNESDAY NIGHT...DUE TO UNCERTAINTY ON EXACT LOCATION OF HEAVIEST RAIN...BUT WILL MENTION HEAVY RAIN IN GRIDS ACROSS SOUTHEAST CWA AND ALSO MENTIONED IN HWO. ON FRIDAY...BOUNDARY ACROSS SOUTHERN NEBRASKA AND SOUTHERN IOWA WILL BEGIN TO LIFT SLOWLY NORTH FRIDAY NIGHT INTO SATURDAY...REACHING I90 ON SATURDAY. SO AS THIS FRONT LIFTS NORTH WOULD EXPECT AT LEAST SCATTERED THUNDERSTORMS TO DEVELOP ON EDGE OF MID LEVEL CAP AS LOW LEVEL JET INCREASES DURING THE NIGHT AND WAVE LIFTS NORTHEAST OUT OF WESTERN NEBRASKA. COULD SEE ELEVATED SEVERE STORMS LATER IN THE NIGHT AS THIS FRONT LIFTS NORTH. WITH FRONT ALONG I90 ON SATURDAY...BEST CHANCE FOR THUNDERSTORMS WILL CONTINUE NORTH OF I90 THROUGH SATURDAY...WITH POTENTIAL FOR MORE HEAVY RAIN...THIS TIME ACROSS NORTHERN CWA SATURDAY NIGHT. WILL HIGHLY DEPEND ON LOCATION OF MID LEVEL CAP AND FRONT AND HEAVIEST RAIN COULD FALL NORTH OF CWA. SO WILL HAVE HIGHEST POPS ACROSS NORTHERN CWA AND FAR SOUTHERN CWA MAY NOT SEE ANYTHING AFTER CONVECTION LIFTS NORTH SATURDAY MORNING. VERY HIGH CAPES SOUTH OF BOUNDARY IN CAPPED AIR OVER NORTHWEST IOWA...BUT DEFINATELY SOMETHING TO WATCH NORTH OF BOUNDARY LATE SATURDAY AFTERNOON AND EVENING FOR A ROUND OF SEVERE WEATHER. AS WE HEAD INTO SUNDAY...COLD FRONT WILL PUSH EAST ACROSS CWA SUNDAY AFTERNOON AND NIGHT WITH YET ANOTHER ROUND OF THUNDERSTORMS. IF MID LEVEL CAP CAN BREAK AHEAD OF THIS FRONT WHICH GFS AND EC HINTING AT...COULD SEE SOME SEVERE WEATHER IN THE AFTERNOON AND EVENING ACROSS THE EASTERN CWA. MEMORIAL DAY LOOKS TO BE QUIET AND DRY AND WILL CONTINUE THAT TREND INTO TUESDAY. TEMPERATURES WILL BE ON A ROLLER COASTER THURSDAY THROUGH SUNDAY...WITH COOLER TEMPERATURES IN THE UPPER 60S TO MID 70S THURSDAY AND FRIDAY AND THEN AS FRONT LIFTS NORTH...HIGHS ON SATURDAY WILL LIKELY VARY FROM NEAR 70 ACROSS THE FAR NORTH TO NEAR 90 FAR SOUTHEAST. SHOULD BE WARMER ACROSS ALL OF CWA ON SUNDAY AHEAD OF FRONT WITH HIGHS IN THE 80S...AND THEN COOLING BACK INTO 70S MONDAY AND TUESDAY. && .AVIATION.../FOR THE 00Z TAF ISSUANCE/ MAINLY VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. STRONG SOUTHERLY WIND GUSTS AROUND 30-35KTS EXPECTED TO PERSIST THROUGH EARLY PART OF TAF PERIOD...THOUGH EVEN AFTER 03Z GUSTS AROUND 25KT WILL REMAIN LIKELY UNTIL COLD FRONT APPROACHES FROM THE WEST LATER TONIGHT...ALLOWING FOR WEAKENING SURFACE GRADIENT/FURTHER DECREASE IN WINDS. MODELS CONTINUE TO SHOW 50-60KT LOW LEVEL JET ABOVE 1500FT AGL...LEADING TO CONCERNS OF LOW LEVEL WIND SHEAR. ALTHOUGH WINDS REMAIN SOMEWHAT GUSTY AT THE SURFACE...WITH LOW LEVEL JET OF THIS MAGNITUDE AND DIRECTION SLIGHTLY VEERED FROM DOMINANT SURFACE WIND DIRECTION...WILL CONTINUE MENTION OF LLWS FOR ALL TAF LOCATIONS TONIGHT. CONFIDENCE IN ELEVATED THUNDERSTORMS AFFECTING TAF SITES OVERNIGHT IS WANING...AS UPPER LEVEL SUPPORT SEEMS TO FOCUS MORE TO THE NORTH OF THIS AREA. WILL HANG ONTO A SMALL WINDOW OF POSSIBLE TSRA FOR KHON 06Z-08Z AS SECONDARY MID LEVEL WAVE MOVES INTO THE AREA. OTHERWISE KEEPING THE TAFS FREE OF PRECIPITATION THROUGH WEDNESDAY. CHANCES WILL INCREASE LATE IN THE PERIOD ALONG AND EAST OF I-29 CORRIDOR AS COLD FRONT PUSHES SLOWLY EAST. HOWEVER...THINK CAPPING INVERSION AHEAD OF THE COLD FRONT COULD SUPPRESS CONVECTION UNTIL AFTER THE END OF THIS TAF PERIOD AND OPTED TO LEAVE POTENTIAL LATE AFTERNOON TSRA OUT OF THIS ISSUANCE. && .FSD WATCHES/WARNINGS/ADVISORIES... IA...WIND ADVISORY FROM 10 AM TO 8 PM CDT TUESDAY FOR IAZ001>003- 012>014-020>022-031-032. MN...WIND ADVISORY FROM 10 AM TO 8 PM CDT TUESDAY FOR MNZ071-072-080- 081-089-090-097-098. NE...WIND ADVISORY FROM 10 AM TO 8 PM CDT TUESDAY FOR NEZ013-014. SD...WIND ADVISORY FROM 10 AM TO 8 PM CDT TUESDAY FOR SDZ038>040-050- 052>071. && $$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
919 PM CDT TUE MAY 22 2012 .UPDATE... EVENING UPDATE. && .DISCUSSION... INTERSECTING BOUNDARIES IN CHAMBERS COUNTY ALLOWED AN ISOLATED STORM TO INTENSIFY THIS EVENING. HAD A REPORT OF PEA SIZED HAIL IN WINNIE BUT THE STRONGEST PART OF THE STORM WAS WEST OF WINNIE. THAT STORM ALONG WITH THE OTHER SHRA/TSRA ACROSS SE TX HAVE WANED WITH THE LOSS OF DAYTIME HEATING. FCST SOUNDINGS INDICATE DRIER AIR MASS IN PLACE FOR WEDNESDAY SO NOT EXPECTING MUCH IN THE WAY OF ISOLATED STORMS TOMORROW. OTHER THAN COSMETIC CLEANING UP OF EVENING WORDING...REST OF THE FCST IS ON TRACK. NEW ZONES OUT BY 945 PM. 43 && .PREV DISCUSSION... /ISSUED 550 PM CDT TUE MAY 22 2012/ AVIATION... ISOLATED CHANCE FOR A THUNDERSTORM THROUGH 03Z. OTHERWISE...VFR EXPECTED. THERE IS AN OUTSIDE CHANCE THAT THE SEA BREEZE MAY BECOME ACTIVE WEDNESDAY AFTERNOON AFTER 21Z. FOR NOW THE CHANCES ARE 10 PERCENT AND WILL NOT MENTION IN THE FORECAST. 40 PREV DISCUSSION... /ISSUED 336 PM CDT TUE MAY 22 2012/ DISCUSSION... SHRA AND A FEW TSRA HAVE FORMED EARLIER TODAY THAN YESTERDAY IN MADISON...WALKER...SAN JACINTO AND LIBERTY COUNTIES AND SLIGHTLY MORE COVERAGE AS WELL. HAVE NUDGED POPS UP AROUND THOSE AREAS FOR THE REST OF THIS AFTERNOON AND INTO THE MID EVENING HOURS. CONVECTIVE TEMPERATURES WERE MET AND UPSTREAM DISTURBANCE HELPED THIS ALONG TODAY. STILL EXPECT TSRA TO BE MOSTLY DIURNAL AND SHOULD DIMINISH AFTER SUNSET. HRRR REFLECTIVITY FIELD FORECASTS AGREE WITH THIS ASSESSMENT AS WELL. GALVESTON HIT 90F AT 1252PM WHICH TIED THE RECORD HIGH FOR TODAY. COULD HAVE GONE A LITTLE HIGHER BUT WINDS SHIFTED ONSHORE WITH A SEA BREEZE JUST A FEW HOURS EARLIER THAN EXPECTED TODAY. AS SURFACE HIGH OVER NW GULF MOVES SLOWLY AWAY AND LEE TROUGH DEVELOPS TOMORROW ONSHORE WINDS WILL INCREASE. PWATS REMAIN AROUND NORMAL FOR MARCH-MAY VALUES. MEAN 1000-700MB SOUTHWESTERLY TO SOUTHWESTERLY WINDS SHOULD INCREASE THE CAPPING INVERSION LEADING TO A DRY SPELL FOR THE NEXT SEVERAL DAYS. GULF MOISTURE DOES NOT LOOK TO BE FULLY TAPPED UNTIL SATURDAY MORNING BUT REMAINS TRAPPED UNDERNEATH GIANT SUBSIDENCE INVERSION AS UPPER RIDGING TAKES HOLD OVER THE EAST HALF OF THE COUNTRY. COULD SEE A FEW VERY LOW TOPPED -SHRA AT TIMES IN THE EXTENDED PERIOD UNDER THE CAP BUT NOT COVERAGE WOULD BE ISOLATED AT BEST AND AMOUNTS VERY VERY LOW SO WILL LEAVE OUT MENTION OF PCPN IN THE EXTENDED. VERY LITTLE CHANGE IN MAX TEMPS THE NEXT FEW DAYS WITH ONLY SOME VERY TINY MODERATION AS LOW LEVEL HUMIDITY AND ONSHORE FLOW COMMENCES. MORNING LOWS TO CLIMB A TAD AS RH INCREASES. NOT BUYING GFS SOLUTION IN LONG RANGE OF LOOP-D-LOOPING SFC LOW RETURNING FROM THE ATLANTIC...PREFER ECMWF LIKE SOLUTION OF CONTINUING TROUGHING OUT THAT WAY. AS A WISE FCSTR ONCE SAID ABOUT THE LONG RANGE TROPICS...IF IT AINT IN THE ECMWF YET I AINT BELIEVING IT. GOOD WORDS GENERALLY. 04 AVIATION... TOOK OUT THE MENTION OF CB/PCPN FOR THIS AFTN WITH THE 18Z TAFS AS THERE WAS SOME UNCERTAINTY CONCERNING THE START TIME TO THE DEVEL- OPMENT. BUT IT LOOKS LIKE THINGS ARE GOING SOONER THAN EXPECTED SO WILL LIKELY BE ADDING VCTS/CB IN THE TAFS VIA AMENDMENTS AS STORMS APPROACH THE VARIOUS SITES. OTHERWISE STILL EXPECTING PCPN TO WANE WITH THE LOSS OF DAYTIME HEATING. MOSTLY VFR OVERNIGHT WITH PATCHY BR IN THE USUAL SPOTS (CXO/LBX). ONSHORE FLOW PATTERN EVOLVING THE NEXT FEW DAYS COULD MAKE FOR A SLIGHTLY MORE ACTIVE SEABREEZE. 41 MARINE... NOT A LOT OF CHANGES TO THE GOING FCST OF DEVELOPING ONSHORE WINDS THE NEXT FEW DAYS. WIND SPEEDS/WAVE HEIGHTS NOT EXPECTED TO BE AT/ NEAR CAUTION/ADVISORY LEVELS UNTIL LATE WEDS AS THE PRESSURE GRAD- IENT TIGHTENS IN RESPONSE TO THE NEXT SYSTEM DEEPENING ACROSS/OVER THE CENTRAL PLAINS. AS THIS PATTERN IS PROGGED TO PERSIST THE REST OF THE WEEK...WE COULD ALSO SEE WAVE HEIGHTS INCREASE STEADILY FOR THIS SAME TIME FRAME. 41 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 70 91 68 90 71 / 10 10 10 10 10 HOUSTON (IAH) 71 91 70 90 73 / 10 10 10 10 10 GALVESTON (GLS) 76 85 76 84 78 / 10 10 10 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...43
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1029 PM CDT TUE MAY 22 2012 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .SHORT TERM...TONIGHT AND WEDNESDAY. THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE STRETCHING FROM THE SOUTHERN GREAT PLAINS AND ACROSS THE CENTRAL GREAT LAKES TO HUDSON BAY. A WARM FRONT HAS BEEN DEVELOPING TODAY OVER THE FAR NORTHERN PLAINS AND OVER WESTERN LAKE SUPERIOR TO THE UPPER PENINSULA. WARM/MOIST ADVECTION NORTH OF THE BOUNDARY IS CONTRIBUTING TO SCT LIGHT SHOWERS AND ISOLATED THUNDERSTORMS FROM NORTHERN MINNESOTA TO THE WESTERN UPPER PENINSULA. SOME RETURNS ARE GRAZING THE U.P. BORDER THIS AFTERNOON...BUT NO CONFIRMATION OF THESE RETURNS REACHING THE GROUND AT IRONWOOD OR LAND O LAKES. THE AIRMASS IS PRETTY DRY IN THIS AREA WITH DEWPOINTS AT LAND O LAKES IN THE LOWER 30S. AS LOW PRESSURE OVER WESTERN NORTH DAKOTA MOVES NORTHEAST...A COLD FRONT WILL MOVE TO THE UPPER MISSISSIPPI VALLEY TOMORROW. WITHOUT MUCH IMPACT YET...CLOUDS AND TEMPS WILL BE THE MAIN FORECAST CONCERNS. TONIGHT...HIGH PRESSURE OVER THE CENTRAL GREAT LAKES TO START THE EVENING WILL SHIFT TO THE EASTERN GREAT LAKES OVERNIGHT. LOW PRESSURE WILL MOVE NORTHEAST OVER THE PLAINS TONIGHT...BUT ITS WARM FRONT WILL REMAIN RELATIVELY STATIONARY OVER THE SOUTH SHORELINE OF LAKE SUPERIOR. WARM/MOIST ADVECTION THAT IS OCCURRING OVER THE ARROWHEAD OF MINNESOTA AND THE UPPER PENINSULA WILL BE LIFTING OFF TO THE NORTHEAST GRADUALLY AS HEIGHTS BUILD ALOFT...EVEN THOUGH CORFIDI VECTORS TRACK THE INDIVIDUAL SHOWERS OFF TO THE SOUTHEAST. THINK THERE IS POTENTIAL FOR THIS SHOWER ACTIVITY TO GRAZE THE U.P.-WISCONSIN BORDER THROUGH 00Z. HOWEVER...LOW LEVELS ARE VERY DRY...SO WILL LEAVE IT AS A CHANCE OF SPRINKLES. RECENT RADAR TRENDS ALREADY SHOW THE BACK EDGE OF THE PRECIP LIFTING NE OVER THE ARROWHEAD...SO AM COUNTING ON THIS TREND KEEPING THE BORDER DRY AFTER 00Z. MID AND UPPER CLOUDS WILL BE LIFTING OFF TO THE NE AS WELL SO SHOULD SEE DECREASING CLOUDS THROUGH THE NIGHT OVER THE NORTH. THE PRESSURE GRADIENT WILL BE TIGHTENING TONIGHT...WHICH WILL KEEP LOWS WARMER THAN LAST NIGHT. WILL GO WITH MID TO UPPER 40S FOR LOWS. WEDNESDAY...UPSTREAM COLD FRONT WILL MOVE INTO THE NORTHERN MISSISSIPPI VALLEY DURING THE AFTERNOON. WITH THE AREA FIRMLY IN THE WARM SECTOR...WILL HAVE MID AND UPPER CLOUDS NORTH AND WEST OF THE REGION...BUT SHOULD SEE MOSTLY CLEAR TO PARTLY CLOUDY SKIES FOR THE DAY. THE PRESSURE GRADIENT WILL TIGHTEN AHEAD OF THE FRONT...AND SOUTH WINDS WILL TURN GUSTY WITH DAYTIME HEATING AND MIXING. SOME GUSTS COULD REACH 30 OR MAYBE EVEN 35 MPH. HIGHS TOMORROW IN THE MID 70S TO LOW 80S. .LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY. ONE OF THE FORECAST CHALLENGES FOR THIS PERIOD IS TRYING TO LASSO IN THE LOCATIONS OF THE FRONT FOR THE MEMORIAL DAY WEEKEND. ANOTHER ISSUE IS TIMING AND STRENGTH OF A SHORT WAVE TROUGH FOR LATER THURSDAY AND ESPECIALLY THURSDAY NIGHT. LITTLE CHANGE FROM THE GOING FORECAST FROM 24 HOURS AGO FROM WEDNESDAY NIGHT INTO THURSDAY AS A SURFACE HIGH PRESSURE WITH UPPER RIDGE DRIFTING OVER THE AREA WILL CONTINUE TO PROVIDE QUIET WEATHER TO THE AREA. MODELS CONTINUE TO CONFINE CONVECTION OVER THE NORTHERN PLAINS WITH THE BROAD UPPER TROUGH. PWATS GRADUALLY INCREASE TO 1.75 ALONG THE FRONT OVER THE NORTHERN PLAINS. UNTIL THIS UPPER RIDGE IS NUDGED FAR ENOUGH EAST...WILL CONTINUE TO CONFINE ANY SMALL PCPN MENTION AND CLOUDS WEST OF A RHI TO AUW LINE. WILL THEN FOCUS ON HIGHER POPS FOR THE THURSDAY AFTERNOON INTO THURSDAY NIGHT PERIOD AS A SHORT WAVE SLIDES OVER THE STATE. A SURFACE LOW AND UPPER JET COUPLET PROGGED TO AFFECT THE NORTH HALF OF THE STATE DURING THIS PERIOD PROVIDES SOME POTENTIAL OF STRONG TO SEVERE STORMS. PROGS ARE A BIT MORE PROGRESSIVE WITH THE FRONTAL PASSAGE LATE THURSDAY NIGHT. USING THE H8 FRONT...THE FRONT IS DRIVEN SOUTH OF THE AREA FRIDAY INTO FRIDAY NIGHT FOR A DIMINISHED PERIOD OF CONVECTION. PROGS IN GOOD AGREEMENT WITH H8 WARM FRONT LIFTING BACK NORTH AGAIN ON SATURDAY SO INCREASED CONVECTION INCLUDING THUNDER FROM SOUTH TO NORTH DURING THE DAY. PROGS CONTINUE TO LIFT THE FRONT NORTH TO GRADUALLY DIMINISH CONVECTION OVER CENTRAL AND EAST CENTRAL WISCONSIN BUT WILL CONFINE BEST PCPN CHANCES ACROSS THE NORTH SUNDAY AND PERHAPS INTO MONDAY CLOSER TO THE WARM FRONT. AREAS TO THE SOUTH LIKELY TO BE CAPPED IN A VERY WARM HUMID AIR MASS AS UPPER HEIGHTS BUILD. ANOTHER FRONT IS PROGGED TO SLIDE OVER MONDAY INTO MONDAY NIGHT FOR ANOTHER SHOT OF CONVECTION. PWATS INCREASE TO 1.70 INCHES ALONG THE FRONT...HOWEVER AT THIS TIME IT APPEARS THE FRONTS ARE A LITTLE TOO PROGRESSIVE FOR HEAVY RAINS TO CONCENTRATE IN ANY ONE LOCATION WITH THE EXCEPTION OF THE FAR NORTH NEAR THE WARM FRONT. && .AVIATION...FOR 06Z TAF ISSUANCE. VFR CONDITIONS EXPECTED TNGT AND WED AS SFC RIDGE SLIDES AWAY TO THE SE AND FRONTAL SYSTEM STARTS TO ADVANCE E FM THE PLAINS. MODELS IN BETTER AGREEMENT ON LLWS NOW...AND HAVE TRENDED TOWARD STRONGER WINDS THE RAP HAD EARLIER. SKOWRONSKI && .MARINE...A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED LATE WEDNESDAY AFTERNOON INTO THURSDAY NIGHT. INCREASING SOUTH WINDS ARE EXPECTED ON WEDNESDAY...THEN STRONG SOUTH WINDS ARE EXPECTED ON THURSDAY. A FEW GUSTS COULD APPROACH GALE FORCE NEAR THE SHORELINE THURSDAY AFTERNOON. WINDS AND WAVES WILL GRADUALLY SUBSIDE THURSDAY NIGHT. FOR THE UPCOMING MEMORIAL DAY WEEKEND...IT WILL BE UNSETTLED AS THERE WILL BE CHANCES FOR THUNDERSTORMS EACH DAY. A WARM FRONT IS EXPECTED TO SLOWLY PUSH NORTHWARD INTO THE AREA OVER THE WEEKEND. THERE IS A LOT OF UNCERTAINTY ON HOW FAR NORTH THE WARM FRONT WILL MAKE IT INTO NORTHEAST WISCONSIN AND WHERE THE BEST CHANCES FOR THUNDERSTORMS WOULD OCCUR. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
605 PM CDT TUE MAY 22 2012 .SHORT TERM...TONIGHT THROUGH FRIDAY 303 PM CDT TUE MAY 22 2012 MAIN FORECAST CONCERNS ARE WHEN PRECIPITATION CHANCES MOVE INTO THE AREA AND SEVERE WEATHER POTENTIAL FOR THURSDAY. CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED TROUGHING OVER SOUTHWEST CANADA AND THE NORTHERN ROCKIES... WITH RIDGING BUILDING DOWNSTREAM OVER THE UPPER MISSISSIPPI RIVER VALLEY REGION. A SHORTWAVE EJECTING OUT OF THE TROUGHING AND DOWNSLOPING UPPER FLOW OFF THE ROCKIES HAS LED TO LOW PRESSURE DEVELOPMENT OVER THE DAKOTAS. INCREASING SOUTHERLY FLOW DOWNSTREAM OF THIS SURFACE LOW ON THE ORDER OF 20-40KT 850MB WINDS PER PROFILER DATA IS SPREADING WARMER AIR NORTHWARD. MODIFYING THROUGH ADVECTION AND DAYTIME HEATING PROCESSES FROM 12Z RAOBS...THE RAP SUGGESTS 850MB TEMPS HAVE RISEN TO 10-14C OVER THE FORECAST AREA. WITH PLENTY OF SUN AND THE INCREASING WINDS...SURFACE TEMPERATURES HAVE CLIMBED INTO THE 70S TO LOW 80S. FARTHER WEST...THE 850MB TEMPS INCREASE TO 18-25C OR HIGHER OVER MUCH OF THE PLAINS. MOISTURE IS ALSO RETURNING...MORE OVER THE PLAINS...WHERE SURFACE DEWPOINTS ARE MOSTLY IN THE 50S. TONIGHT AND WEDNESDAY...TROUGHING OVER THE NORTHERN ROCKIES IS FORECAST TO DEEPEN ACROSS THE WESTERN U.S....RESULTING IN STRENGTHENING RIDGING DOWNSTREAM INTO THE GREAT LAKES. A COUPLE OF SHORTWAVES EJECTING OUT OF THIS TROUGHING WILL HELP LIFT THE LOW IN THE DAKOTAS INTO FAR NORTHWEST ONTARIO...DRAGGING A COLD FRONT INTO WESTERN MINNESOTA BY 00Z. INCREASING SOUTH TO SOUTHWEST FLOW ALOFT AHEAD OF THE FRONT WILL HELP BRING WARMER AIR INTO THE FORECAST AREA WITH 850MB TEMPS CLIMBING TO AT LEAST 16-18C BY 18Z WEDNESDAY. WE SHOULD ALSO SEE AN INCREASE IN ALTOSTRATUS AND CIRROSTRATUS... ALREADY EVIDENT OVER EASTERN MONTANA AND WYOMING. THESE CLOUDS MAY TEMPER HIGHS SOMEWHAT...BUT READINGS SHOULD EASILY REACH INTO THE 80S GIVEN THE STRENGTH OF THE WARM ADVECTION/WINDS AND SUN. LOWS TONIGHT ALSO EXPECTED TO BE WARMER WITH THE INCREASING WINDS... ESPECIALLY ACROSS SOUTHEAST MINNESOTA. REGARDING PRECIPITATION CHANCES...ANY CONVECTION SHOULD BE STRONGLY TIED TO THE FRONT. AHEAD OF THE FRONT...MODELS SUGGEST QUITE A BIT OF CIN...EVEN WITH THEIR HIGHER SURFACE DEWPOINTS LIKE THE NAM SUGGESTS. THERE IS ALSO MIX DOWN POTENTIAL OF THE DEWPOINTS WITH PLENTIFUL DRY AIR BELOW 700MB. THEREFORE...THINKING THE ENTIRE FORECAST AREA SHOULD BE DRY THROUGH WEDNESDAY. LAST ITEM OF NOTE IS WINDS COULD GET CLOSE TO ADVISORY CRITERIA IN SOUTHEAST MN LATE IN THE MORNING INTO MID AFTERNOON... JUST BASED ON THE SPEEDS THEMSELVES. SOMETHING TO WATCH. WEDNESDAY NIGHT AND THURSDAY...AT THE BASE OF THE DEEPENING WESTERN TROUGH...A NEW SURFACE LOW SHOULD HAVE DEVELOPED OVER FAR SOUTHEAST COLORADO BY 00Z THURSDAY. THIS SURFACE LOW IS EXPECTED TO LIFT NORTHEAST...ALONG THE COLD FRONT THAT MOVED INTO WESTERN MINNESOTA LATE WEDNESDAY...DUE TO ANOTHER COLLECTION OF SHORTWAVES EJECTING OUT OF THE WESTERN TROUGH. THEREFORE...THE FRONT WEDNESDAY NIGHT IS LIKELY TO NOT MAKE MUCH IF ANY PROGRESS EASTWARD. IN FACT...WE NEED TO WAIT UNTIL THE LOW MOVES NORTH OF THE AREA TO DRIVE THE COLD FRONT EASTWARD. THIS DRIVE EASTWARD TOO WILL BE ENHANCED BY A FAIRLY POTENT SHORTWAVE COMING UP INTO MINNESOTA. FOR WEDNESDAY NIGHT... AGAIN CONVECTION SHOULD REMAIN TIED AROUND THE COLD FRONT IN MINNESOTA. VARIOUS THINGS GOING FOR CONVECTION INCLUDE A RIGHT ENTRANCE REGION OF A JET LIFTING OUT OF THE DAKOTAS...INCREASING LOW TO MID-LEVEL FRONTOGENESIS ON THE COLD FRONT...AND A PLUME OF 500-1000 J/KG OF MUCAPE BEING TRANSPORTED INTO THE FRONTOGENESIS ZONE BY A STRENGTHENING LOW LEVEL JET. AS IT STANDS RIGHT NOW...MOST MODELS SUGGEST THE FRONT AND BULK OF CONVECTION WILL END UP WEST OF THE FORECAST AREA. HAVE MAINTAINED SOME CHANCES OVER THE NORTHWEST ENDS...THOUGH...AS CONVECTIVE OUTFLOWS MAY TRY TO PUSH THE FRONT EASTWARD. THURSDAY IS DEFINITELY MORE CONCERNING AS THE POTENT SHORTWAVE APPROACHES IN THE AFTERNOON. SOME SLIGHT TIMING DIFFERENCES EXIST ON THE COLD FRONTAL PASSAGE AND APPROACH OF THE SHORTWAVE...BUT THERE IS GOOD AGREEMENT THAT THE DYNAMICAL AND THERMODYNAMICAL FORCING WILL LIKELY LEAD TO A SQUALL LINE ALONG THE FRONT EARLY TO MID AFTERNOON...ALONG WITH POST-FRONTAL PRECIPITATION. THIS PRECIPITATION THEN PUSHES EAST INTO THE EVENING. RAISED PRECIPITATION CHANCES TO 50-70 FOR THE AFTERNOON. PLENTIFUL 0-6 KM AND 0-3KM SHEAR AND MLCAPE OF 500-1000 J/KG SHOULD BE ENOUGH TO PRODUCE SOME SEVERE WEATHER...WITH DAMAGING WINDS MAIN HAZARD. TEMPERATURES LIKELY TO STAY WARM WEDNESDAY NIGHT AND THURSDAY DUE TO BREEZY WINDS...WITH A POSSIBLE FALL IN TEMPERATURES IN THE AFTERNOON AS THE FRONT/PRECIPITATION MOVE THROUGH. WINDS COULD GET CLOSE TO ADVISORY CRITERIA ON THURSDAY. THURSDAY NIGHT AND FRIDAY...AFTER THE SQUALL LINE AND COLD FRONT MOVE THROUGH IN THE EVENING...STRONG SUBSIDENCE IS INDICATED TO MOVE INTO THE FORECAST AREA. RAISED PRECIPITATION CHANCES EAST OF THE MISSISSIPPI RIVER TO 50-70 TO HANDLE THE SQUALL LINE. CONDITIONS SHOULD THEN DRY OUT AFTER MIDNIGHT THANKS TO THE SUBSIDENCE... PRODUCED MOSTLY BY THAT POTENT SHORTWAVE WHICH LIFTS INTO UPPER MICHIGAN. THE COLD FRONT LOOKS TO STALL OVER NORTHERN MISSOURI FRIDAY MORNING. NEW DEEPER TROUGHING THEN FORMS IN THE WESTERN U.S....CAUSING RIDGING TO RE-BUILD DOWNSTREAM INTO THE MID-MISSISSIPPI VALLEY. DEPENDING ON THIS TIMING OF THE RIDGING BUILDING UP...THE FRONT MAY START MOVING BACK NORTH IN THE AFTERNOON...AS INDICATED IN THE 22.12Z NAM/GEM. MOISTURE TRANSPORT OVER THIS FRONT COULD LEAD TO A FEW SHOWERS AND THUNDERSTORMS OVER NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN...THOUGH DEFINITELY BETTER CHANCES WOULD BE OVER SOUTHERN IOWA CLOSER TO THE FRONT. COOLER AIR ADVECTING IN BEHIND THE FRONT SHOULD HELP SEND TEMPERATURES BACK DOWN TO SEASONABLE LEVELS. .LONG TERM...FRIDAY NIGHT THROUGH TUESDAY 303 PM CDT TUE MAY 22 2012 MODELS AND GFS ENSEMBLES ARE INCREASINGLY BECOMING IN GOOD AGREEMENT FOR THE WEEKEND...INDICATING TROUGHING TO PERSIST OVER THE WESTERN U.S. WHILE STRONG SUBTROPICAL RIDGING BUILDS OVER THE EASTERN TWO THIRDS OF THE COUNTRY. WITH THIS BUILDING RIDGING...THE WARM FRONT ON FRIDAY SITUATED EITHER OVER SOUTHERN IOWA OR NORTHERN MISSOURI WILL GRADUALLY LIFT NORTH ACROSS THE FORECAST AREA. THE SPEED OF THIS MAY BE MODULATED BY PERIODS OF CONVECTION FORMING ON THE WARM FRONTAL BOUNDARY...IN RESPONSE TO FRONTOGENESIS AND ESPECIALLY INCREASING LOW LEVEL JET/MOISTURE TRANSPORT AT NIGHT. BEST TIME PERIOD FOR CONVECTION ACROSS THE AREA WOULD PROBABLY BE FRIDAY NIGHT INTO SATURDAY MORNING. SATURDAY NIGHT INTO SUNDAY MORNING COULD OCCUR TOO OVER FAR NORTHERN PORTIONS OF THE AREA...DEPENDING ON HOW FAR NORTH THE WARM FRONT REACHES. EITHER ROUND OF CONVECTION COULD BE SEVERE...GIVEN 1-6 KM SHEAR VALUES OF 40KT OR MORE AND LIKELY PLENTY OF INSTABILITY BEING ADVECTED OVER THE FRONTAL ZONE. ONCE THE WARM FRONT PASSES...850MB TEMPS JUMP TO 20C OR HIGHER. SUNDAY LOOKS TO BE THE WARM DAY WITH TEMPERATURES LIKELY WELL INTO THE 80S...PERHAPS EVEN 90S. THINGS GET A LITTLE MORE MURKY FOR EARLY NEXT WEEK...IN PARTICULAR WITH THE HANDLING OF THE WESTERN TROUGH. THE 22.00Z/22.12Z ECMWF/GEM AND SOME OF THE 22.12Z GFS ENSEMBLES SUGGEST THE WESTERN TROUGH WILL BE SLOWER TO EJECT NORTHEASTWARD THAN THE 22.12Z GFS AND THE REST OF ITS ENSEMBLES. THIS SEEMS REASONABLE GIVEN THE STRENGTH OF THE RIDGING AHEAD OF THE TROUGH. THEREFORE...LIKELY THE COLD FRONT ASSOCIATED WITH THE TROUGH WILL BE SLOWER TO MOVE THROUGH THE FORECAST AREA. THIS RESULTS IN A WARMER DAY ON MONDAY THAN WHAT THE GFS WOULD SUGGEST. TUESDAY WOULD BE COOLER AFTER THE FRONTAL PASSAGE. DID MAINTAIN THE CONSENSUS APPROACH FOR PRECIPITATION CHANCES MONDAY THROUGH TUESDAY...GIVEN THE DIFFERENCES. && .AVIATION... 605 PM CDT TUE MAY 22 2012 WINDS WILL BE THE MAIN AVIATION CONCERN TONIGHT INTO WEDNESDAY AFTERNOON. TIGHTENING PRESSURE GRADIENT AHEAD OF A COLD FRONT WILL KEEP SOUTHERLY WINDS BRISK TONIGHT. BUFKIT RAP/NAM12 SOUNDINGS POINT TO 50 KTS BY 2 KFT AT KRST...ENOUGH TO WARRANT A LLWS MENTION FOR THAT LOCATION. A BIT LESS AT KLSE...SO WILL NOT ADD MENTION THERE. WINDS GO FROM SOUTH TO SOUTHWEST ALOFT...AND NOT OVERLY UNI-DIRECTION. STILL...WITH ONLY A FEW HIGH CLOUDS SPREADING IN FROM THE WEST...THERE SHOULD BE ENOUGH MIXING TO LEAD TO HIGHER GUSTS...ALREADY BY EARLY MORNING...CONTINUING INTO THE AFTERNOON. THIS COULD BE BORDER-LINE WIND ADVISORY FOR PARTS OF SOUTHEAST MN...WHICH WOULD INCLUDE KRST. TRENDS HAVE BEEN TO MOVE THE FRONT IN A BIT LATER...AND THEREFORE THE FRONT WILL LIKELY BE MORE OF A FACTOR ON THU. CONVECTION WILL BE ONGOING ALONG AND BEHIND IT AS IT MOVES IN...LIKELY IMPACTING KRST/KLSE DURING THE AFTERNOON. && .ARX WATCHES/WARNINGS/ADVISORIES... 303 PM CDT TUE MAY 22 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM....AJ AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
445 PM CDT MON MAY 21 2012 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE .SHORT TERM...TONIGHT AND TUESDAY. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE HIGH PRESSURE STRETCHING FROM TEXAS TO WESTERN ONTARIO THIS AFTERNOON. MID AND HIGH CLOUDS ARE ADVANCING TO THE EAST OVER THE NORTHERN PLAINS AND INTO THE NORTHERN MISSISSIPPI VALLEY...BUT DRY AIR ACROSS THE REGION IS DISSIPATING THE CLOUDS ON THE LEADING EDGE. MUCH COOLER AND DRIER CONDITIONS ARE PRESENT ACROSS THE REGION TODAY WITH ONLY SOME DIURNAL CU DEVELOPING OVER EASTERN WISCONSIN. WITH A DRY AIRMASS IN PLACE...TEMPS AND FROST HEADLINES ARE THE MAIN FORECAST CONCERNS. TONIGHT...HIGH PRESSURE WILL BE DRAPED ACROSS THE REGION TONIGHT...WHICH WILL KEEP A DRY AIRMASS IN PLACE BELOW 700MB. THETAE ADVECTION ABOVE THIS LEVEL MAY BRING FEW/SCT CLOUDS FROM THE NORTHERN MISSISSIPPI VALLEY INTO NORTH-CENTRAL WISCONSIN...THOUGH IMPACT ON TEMPS SHOULD BE MINIMAL. GOOD RADIATIVE COOLING CONDITIONS WILL SUPPORT TEMPS FALLING FROM THE MID 30S NORTH TO LOW 40S SOUTH. TEMPS WILL FALL LOCALLY COOLER WITHIN THE SANDY SOIL AREAS OF NORTH-CENTRAL AND FAR NORTHEAST WISCONSIN WHERE TEMPS MAY EVEN FALL TO THE UPPER 20S. WILL HOIST A FROST ADVISORY NORTH OF A LINCOLN TO NORTHERN MARINETTE LINE. TUESDAY...HIGH PRESSURE WILL DRIFT FROM EASTERN WISCONSIN TO THE CENTRAL GREAT LAKES. RELATIVELY THIN MID AND HIGH CLOUDS WILL MOVE OVERHEAD DURING THE COURSE OF THE DAY...WHICH SHOULD KEEP SKY CONDITIONS MOSTLY CLEAR TO PARTLY CLOUDY. A WARM FRONT WILL BE STRETCHED ALONG THE US-CANADIAN BORDER AND PRECIP CHANCES SHOULD REMAIN NORTHWEST OF THE FORECAST AREA. 925MB TEMPS ARE A DEGREE OR TWO WARMER TOMORROW...SO WILL GO WITH HIGHS IN THE LOW TO MID 70S. .LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY. MAIN FORECAST CHALLENGE FOR THIS PERIOD IS TRYING TO ADD SOME RESOLUTION TO THE VARIOUS PCPN CHANCES STARTING LATER THIS WEEK...ALONG WITH ADJUSTING ANY MAX TEMPS DUE TO VARIOUS SOLUTIONS OF BOUNDARY LOCATIONS. SURFACE HIGH PRESSURE WITH UPPER RIDGE WILL CONTINUE TO PROVIDE QUIET WEATHER TO THE AREA TUESDAY NIGHT INTO THURSDAY FOR MOST LOCATIONS. CONVECTION WILL BE CONFINED TO THE NORTHWEST STATES AND NORTHERN PLAINS AS A BROAD UPPER TROUGH SETTLES INTO THIS AREA. WILL CONFINE ANY SMALL PCPN MENTION AND MORE CLOUDS WEST OF A RHI TO AUW LINE DUE TO THE POSSIBILITY OF ANY NORTHERN PLAINS CONVECTION BRUSHING NORTHWEST WISCONSIN. WILL THEN FOCUS ON THE HIGHER END CHC POPS FOR THE THURSDAY NIGHT INTO FRIDAY MORNING PERIOD AS A SHORT WAVE SLIDES OVER THE STATE WITH SURFACE FROPA. WILL DIMINISH PCPN LATER FRIDAY BUT STILL UNKNOWN HOW FAR SOUTH THE FRONT WILL SETTLE AS THE UPPER FLOW REMAINS SOUTHWEST. WILL ALSO KEEP CHC POPS GOING DUE TO A BAROCLINIC ZONE LINGERING OVER THE STATE IN THE COOL SECTOR. WITH COOLER TEMPS AND LITTLE INSTABILITY...DOWNPLAYED TSRA MENTION TO SHOWERS FRIDAY NIGHT. INSTABILITY INCREASES AGAIN LATER SATURDAY. MEDIUM MODEL RUNS BEGINNING TO SHOW SOME CONSENSUS OF THE FRONTAL BOUNDARY LIFTING NORTH AGAIN IN RESPONSE TO THE WESTERN STATES TROUGH DEEPENING AND EASTERN STATES UPPER RIDGE BUILDING. AGAIN ANOTHER WAVE WITH FRONTAL SYSTEM ATTEMPTS TO SLIDE OVER THE REGION LATER SUNDAY NIGHT INTO MONDAY FOR A FIRST STAB AT THE TIMING. WENT WITH COOLER TEMPS SATURDAY WITH LAGGING BAROCLINIC ZONE BUT WARMER SUNDAY MAX TEMPS AS UPPER HEIGHTS BUILD AND THE FRONT LIFTS NORTH AS A WARM FRONT. && .AVIATION...FOR 00Z TAF ISSUANCE. VFR CONDITIONS EXPECTED THROUGH THE NEXT 24 HRS AS SFC RIDGE SLOWLY CROSSES THE RGN. && .GRB WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY FROM 2 AM TO 7 AM CDT TUESDAY FOR WIZ005-010>013- 018-019-021. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
325 PM CDT MON MAY 21 2012 .SHORT TERM...TONIGHT THROUGH THURSDAY 325 PM CDT MON MAY 21 2012 MAIN FORECAST CONCERNS ARE FROST POTENTIAL TONIGHT AND PRECIPITATION CHANCES AS WELL AS TEMPERATURES WEDNESDAY INTO THURSDAY. CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED RIDGING FROM THE DESERT SOUTHWEST INTO ALBERTA AND WEAK TROUGHING OVER THE WESTERN GREAT LAKES REGION. HIGH PRESSURE DOMINATES AT THE SURFACE ON THE BACK SIDE OF THE WEAK TROUGHING... ENCOMPASSING THE ENTIRE FORECAST AREA. DRY AIR...SEEN ON THE 12Z MPX...GRB AND DVN SOUNDINGS HAS RESULTED IN A SUNNY DAY ACROSS THE FORECAST AREA. MIXING UP THROUGH 850MB WHERE TEMPS ARE AROUND 6C HAS YIELDED TEMPERATURES MAINLY IN THE 70S...AND DEWPOINTS MOSTLY DOWN INTO THE LOW TO MID 30S. TO THE WEST...AN AREA OF MID LEVEL CLOUDS HAVE BEEN EXPANDING ACROSS NORTH DAKOTA AND INTO WESTERN MINNESOTA. THESE CLOUDS ARE IN RESPONSE TO WARM ADVECTION AND MOISTURE RETURN ON THE BACK SIDE OF THE SURFACE HIGH AND AHEAD OF THE UPPER RIDGE AXIS. THERE WAS A LITTLE LIGHT SHOWER ACTIVITY ON THE WESTERN SIDE OF THE CLOUDS...ASSOCIATED WITH 305 K ISENTROPIC LIFT...BUT THIS HAS SINCE DISSIPATED. 12Z SOUNDINGS SHOWED MUCH WARMER AIR OVER THE DAKOTAS...WITH 850MB TEMPS OF 10-15C ON AVERAGE WITH RAPID CITY AT 19C. TONIGHT AND TUESDAY...UPPER RIDGING OVER THE NORTHERN ROCKIES WILL SHIFT EAST INTO THE FORECAST AREA ON TUESDAY...PUSHED ALONG BY TROUGHING CURRENTLY OFF THE PACIFIC NORTHWEST MOVING INLAND. IN RESPONSE...A SURFACE LOW DEEPENS ACROSS THE DAKOTAS...INCREASING THE WARM ADVECTION DOWNSTREAM INTO THE FORECAST AREA. WITH THIS WARM ADVECTION WE SHOULD SEE SOME OF THOSE MID CLOUDS OVER WESTERN MINNESOTA MOVE ACROSS. TRENDS IN MODEL RH FIELDS SUGGEST SOME DISSIPATION OF THE MID CLOUDS AS THEY PUSH EAST...ESPECIALLY DURING THE DAY TUESDAY. THIS MATCHES THE PREVIOUS FORECAST. IN ADDITION... IT APPEARS MOST OF THE MID CLOUDS WILL STAY WEST OF THE MISSISSIPPI RIVER TONIGHT. THIS IS CRITICAL BECAUSE THE SURFACE RIDGE SHOULD BE CENTERED OVER WISCONSIN MUCH OF TONIGHT...LEADING TO FAVORABLE RADIATIONAL COOLING CONDITIONS. SINCE BLACK RIVER FALLS AND SPARTA DROPPED INTO THE LOW TO MID 30S LAST NIGHT...SEE NO REASON WHY THAT WILL NOT HAPPEN AGAIN. THIS MEANS THAT OUR TYPICAL WISCONSIN COLD SPOTS COULD SEE SOME FROST. NOT ENOUGH OF AN EXPANSIVE AREA OF COLD TEMPS IS FORECAST TO WARRANT A FROST ADVISORY...THOUGH. WEST OF THE MISSISSIPPI RIVER...INCREASING WINDS SHOULD ALLOW TEMPERATURES TO STAY WARMER THERE. WITH INCREASING SUNSHINE AND SOUTHERLY WINDS ON TUESDAY...AS WELL AS 850MB TEMPS CLIMBING TO AROUND 10C BY 18Z...SHOULD ALLOW FOR HIGHS WELL INTO THE 70S. WARMEST TEMPS LIKELY WEST. TUESDAY NIGHT AND WEDNESDAY...THE UPPER TROUGHING OVER THE NORTHWEST U.S. IS PROGGED TO DEEPEN DURING THIS PERIOD. A FAIRLY POTENT SHORTWAVE EJECTING OUT OF THIS TROUGH THROUGH THE DAKOTAS WILL CAUSE THE LOW PRESSURE AREA THERE TO LIFT INTO NORTHWEST ONTARIO BY 00Z THURSDAY. ITS ASSOCIATED COLD FRONT APPEARS TO BE TRENDING SLOWER...NOW ONLY REACHING WESTERN MINNESOTA BY 00Z THURSDAY. THE ECMWF HAS BEEN SUGGESTING THIS FOR QUITE AWHILE. ONLY MODEL THAT HAS THE FRONT APPROACHING THE FORECAST AREA IS THE 21.12Z NAM...AND EVEN IT HAS TRENDED SLOWER FROM ITS PREVIOUS RUNS. THEREFORE...HAVE CONSIDERED THE NAM A FAST OUTLIER. ANY CONVECTION IS LIKELY TO BE HIGHLY TIED TO THE FRONT...GIVEN CAPPING PRESENT IN THE WARM SECTOR AHEAD OF IT. THEREFORE...HAVE DRIED OUT MUCH OF THE FORECAST EXCEPT FOR A SMALL AREA IN SOUTHEAST MINNESOTA WHICH IS CLOSEST TO THE FRONTAL BOUNDARY. THESE SMALL CHANCES MAY BE ABLE TO BE PULLED IN LATER FORECASTS. A BREEZY SOUTH WIND WILL HELP KEEP TEMPERATURES UP TUESDAY NIGHT INTO THE 50S IN MOST LOCATIONS. SOME OF SOUTHEAST MN MAY NOT DROP BELOW 60...MEANWHILE THE COLD SPOTS OF WISCONSIN COULD DECOUPLE AND DROP INTO THE UPPER 40S. MUCH WARMER 850MB TEMPS ARE PROGGED FOR WEDNESDAY...ON THE ORDER OF 16-18C. NORMALLY THIS COULD PRODUCE HIGHS OF 85 TO 90. HOWEVER...THERE IS INCREASING CIRRUS THROUGH THE DAY TO TEMPER HIGHS SOMEWHAT. WEDNESDAY NIGHT AND THURSDAY...ANOTHER SURFACE LOW IS PROGGED TO FORM OVER SOUTHEAST COLORADO LATE WEDNESDAY. A POTENT SHORTWAVE EJECTING OUT OF THE DEEPENING WESTERN TROUGH WILL LIFT THIS LOW NORTHEAST...RIDING UP THE COLD FRONT AND CROSSING CENTRAL MINNESOTA ON THURSDAY. THE 21.12Z GFS/UKMET BOTH DEPICT SOME QPF WEDNESDAY NIGHT OVER WISCONSIN...BUT THESE SEEM ODD GIVEN OUR FORECAST AREA IS UNDERNEATH THE MAIN MOISTURE TRANSPORT STREAM WITHOUT MOISTURE CONVERGENCE...AS WELL AS CAPPING ALOFT TO ELEVATED CONVECTION. THEREFORE...FOR WEDNESDAY NIGHT...KEPT ALL PRECIPITATION CHANCES OVER FAR NORTHWEST SECTIONS OF THE FORECAST AREA. THESE CHANCES ARE STILL LOW...20-30...BECAUSE THE FRONTOGENETICAL ZONE ASSOCIATED WITH THE COLD FRONT LOOKS TO STAY ACTIVE ALONG AND NORTHWEST OF IT...WHICH KEEPS THE BULK OF THE PRECIPITATION MORE FROM SOUTHWEST MINNESOTA INTO THE DULUTH AREA. BETTER SHOT EXISTS FOR THE COLD FRONT TO COME IN ON THURSDAY...IN THIS CASE ASSOCIATED WITH THE NEW LOW COMING UP. THE 21.12Z GFS REMAINS THE FASTEST MODEL TO DO SO...WITH THE ECMWF AND ESPECIALLY GEM SUGGESTING SLOWER. LEANED TOWARDS THE SLOWER PASSAGE...WHICH KEEPS ALL PRECIPITATION CHANCES OVER THE NORTHWEST HALF OF THE FORECAST AREA. TEMPERATURES BOTH WEDNESDAY NIGHT AND ESPECIALLY THURSDAY HAVE BEEN WARMED UP...DUE TO THE SLOWER FRONTAL PASSAGE AND MAINTAINING A LONGER PERIOD OF BREEZY SOUTH WINDS. THURSDAY COULD TOUCH 90...ESPECIALLY IN THE SOUTHEAST WHERE MORE SUN IS PRESENT TO COMBINE WITH 850MB TEMPS UP POSSIBLY NEAR 20C. .LONG TERM...THURSDAY NIGHT THROUGH MONDAY 325 PM CDT MON MAY 21 2012 MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES AND WHEN THE HEAT UP WILL COME. MODELS ARE BECOMING IN MUCH BETTER AGREEMENT ON THE LONG TERM FORECAST...SO CONFIDENCE IS INCREASING ON WHAT WILL HAPPEN. IN GENERAL...TROUGHING LOOKS TO REMAIN IN THE WESTERN U.S.... INTENSIFYING BY SATURDAY MORNING. WITH THE DEEPENING TROUGH OUT WEST...THE RESPONSE IS TO BUILD SOME PRETTY STRONG RIDGING TO THE EAST. THEREFORE...AFTER WHAT LOOKS TO BE A COLD FRONTAL PASSAGE THURSDAY NIGHT...THAT COLD FRONT WILL NOT BE ABLE TO DROP TOO FAR SOUTH. MAINTAINED SOME CHANCES OF SHOWERS AND THUNDERSTORMS FOR THURSDAY NIGHT...AND THESE MAY NEED TO BE INCREASED OVER WESTERN SECTIONS WITH A SHORTWAVE PROGGED TO COME OUT. IN FACT...IF THE 21.12Z ECMWF/GEM ARE CORRECT...SOME OF THE STORMS THURSDAY NIGHT COULD BE SEVERE. WESTERN SECTIONS OF THE AREA LOOK TO GET A BREAK FROM PRECIPITATION ON FRIDAY WITH THE FRONT PASSED...BUT STILL MAINTAINED A CHANCE ELSEWHERE SINCE THE FRONT IS STILL MOVING THROUGH. DEFINITELY COOLER ON FRIDAY BEHIND THE FRONT...BUT STILL SEASONABLE. FRONT SHOULD LAY UP IN SOUTHERN IOWA FRIDAY NIGHT AND THEN BEGIN TO RETREAT NORTH AS A WARM FRONT AS THE UPPER RIDGE STRENGTHENS. MOISTURE TRANSPORT NORTH OF THE FRONT COULD YIELD CONVECTION FRIDAY NIGHT THROUGH SATURDAY. CANNOT RULE OUT SOME OF THIS BEING SEVERE TOO. 850MB TEMPS CLIMB TO 20C OR HIGHER SOUTH OF THE FRONT...WHICH MEANS ON SATURDAY THERE IS POTENTIAL FOR A 20 DEGREE OR MORE SPREAD ACROSS THE FORECAST AREA. MODELS AGREE THAT THE WESTERN TROUGH BEGINS EJECTING OUT SATURDAY NIGHT...ALLOWING THE RIDGE AND WARM SECTOR TO BUILD OVER THE FORECAST AREA. THIS MEANS THE CONVECTION SHOULD SLOWLY SHIFT NORTH...ALLOWING FOR HEAT AND LIKELY SOME HUMIDITY TO MOVE IN. RAISED HIGHS ON SUNDAY TO THE MID 80S TO NEAR 90...BUT FURTHER INCREASES COULD BE NEEDED. SAME GOES FOR LOWS SATURDAY NIGHT AND SUNDAY NIGHT WHERE POTENTIAL EXISTS FOR TEMPERATURES TO NOT DIP BELOW 70. LAST ISSUE IS A COLD FRONT PROGGED TO COME AT THE AREA FOR SUNDAY NIGHT AND MONDAY...ASSOCIATED WITH THE EJECTING WESTERN TROUGH. THE GFS IS THE FASTEST ON THIS FRONT...WHEREAS THE 21.12Z ECMWF HAS SLOWED DOWN FROM ITS PREVIOUS RUN. FOR NOW HAVE FOLLOWED A CONSENSUS AND INCLUDED 20-40 PERCENT CHANCES FOR SUNDAY NIGHT AND MONDAY. HOWEVER...WOULD NOT BE SURPRISED IF THE SLOWER FRONTAL TIMING PANS OUT...RESULTING IN A WARMER AND DRIER FORECAST. IN SUMMARY...SOME POTENTIAL FOR SEVERE STORMS THURSDAY NIGHT AND FRIDAY NIGHT/SATURDAY...THEN HEATING UP FOR THE END OF MEMORIAL DAY WEEKEND. && .AVIATION...THROUGH 18Z TUESDAY 1233 PM CDT MON MAY 21 2012 HIGH PRESSURE WILL BE ENTRENCHED ACROSS THE UPPER MIDWEST REGION THROUGH TUESDAY MORNING AND PROVIDE LIGHT WINDS AND VFR CONDITIONS AT BOTH RST AND LSE TAF SITES. AS THE HIGH PRESSURE SYSTEM BUILDS EAST OF THE AREA...THE PRESSURE GRADIENT BEGINS TO TIGHTEN AND ALLOWS FOR SOUTHERLY WINDS TO INCREASE...ESPECIALLY OVER SOUTHEAST MINNESOTA AND NORTHEAST IOWA. WIND SPEEDS ARE EXPECTED TO BE AROUND 15 KNOTS WITH GUSTS UP TO 23 KNOTS AT KRST BY 14Z TUESDAY AND SUSTAINED AT 12 KNOTS AT LSE BY 15Z TUESDAY. && .ARX WATCHES/WARNINGS/ADVISORIES... 325 PM CDT MON MAY 21 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...DTJ
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
218 PM CDT MON MAY 21 2012 .SHORT TERM...TONIGHT AND TUESDAY. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE HIGH PRESSURE STRETCHING FROM TEXAS TO WESTERN ONTARIO THIS AFTERNOON. MID AND HIGH CLOUDS ARE ADVANCING TO THE EAST OVER THE NORTHERN PLAINS AND INTO THE NORTHERN MISSISSIPPI VALLEY...BUT DRY AIR ACROSS THE REGION IS DISSIPATING THE CLOUDS ON THE LEADING EDGE. MUCH COOLER AND DRIER CONDITIONS ARE PRESENT ACROSS THE REGION TODAY WITH ONLY SOME DIURNAL CU DEVELOPING OVER EASTERN WISCONSIN. WITH A DRY AIRMASS IN PLACE...TEMPS AND FROST HEADLINES ARE THE MAIN FORECAST CONCERNS. TONIGHT...HIGH PRESSURE WILL BE DRAPED ACROSS THE REGION TONIGHT...WHICH WILL KEEP A DRY AIRMASS IN PLACE BELOW 700MB. THETAE ADVECTION ABOVE THIS LEVEL MAY BRING FEW/SCT CLOUDS FROM THE NORTHERN MISSISSIPPI VALLEY INTO NORTH-CENTRAL WISCONSIN...THOUGH IMPACT ON TEMPS SHOULD BE MINIMAL. GOOD RADIATIVE COOLING CONDITIONS WILL SUPPORT TEMPS FALLING FROM THE MID 30S NORTH TO LOW 40S SOUTH. TEMPS WILL FALL LOCALLY COOLER WITHIN THE SANDY SOIL AREAS OF NORTH-CENTRAL AND FAR NORTHEAST WISCONSIN WHERE TEMPS MAY EVEN FALL TO THE UPPER 20S. WILL HOIST A FROST ADVISORY NORTH OF A LINCOLN TO NORTHERN MARINETTE LINE. TUESDAY...HIGH PRESSURE WILL DRIFT FROM EASTERN WISCONSIN TO THE CENTRAL GREAT LAKES. RELATIVELY THIN MID AND HIGH CLOUDS WILL MOVE OVERHEAD DURING THE COURSE OF THE DAY...WHICH SHOULD KEEP SKY CONDITIONS MOSTLY CLEAR TO PARTLY CLOUDY. A WARM FRONT WILL BE STRETCHED ALONG THE US-CANADIAN BORDER AND PRECIP CHANCES SHOULD REMAIN NORTHWEST OF THE FORECAST AREA. 925MB TEMPS ARE A DEGREE OR TWO WARMER TOMORROW...SO WILL GO WITH HIGHS IN THE LOW TO MID 70S. .LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY. MAIN FORECAST CHALLENGE FOR THIS PERIOD IS TRYING TO ADD SOME RESOLUTION TO THE VARIOUS PCPN CHANCES STARTING LATER THIS WEEK...ALONG WITH ADJUSTING ANY MAX TEMPS DUE TO VARIOUS SOLUTIONS OF BOUNDARY LOCATIONS. SURFACE HIGH PRESSURE WITH UPPER RIDGE WILL CONTINUE TO PROVIDE QUIET WEATHER TO THE AREA TUESDAY NIGHT INTO THURSDAY FOR MOST LOCATIONS. CONVECTION WILL BE CONFINED TO THE NORTHWEST STATES AND NORTHERN PLAINS AS A BROAD UPPER TROUGH SETTLES INTO THIS AREA. WILL CONFINE ANY SMALL PCPN MENTION AND MORE CLOUDS WEST OF A RHI TO AUW LINE DUE TO THE POSSIBILITY OF ANY NORTHERN PLAINS CONVECTION BRUSHING NORTHWEST WISCONSIN. WILL THEN FOCUS ON THE HIGHER END CHC POPS FOR THE THURSDAY NIGHT INTO FRIDAY MORNING PERIOD AS A SHORT WAVE SLIDES OVER THE STATE WITH SURFACE FROPA. WILL DIMINISH PCPN LATER FRIDAY BUT STILL UNKNOWN HOW FAR SOUTH THE FRONT WILL SETTLE AS THE UPPER FLOW REMAINS SOUTHWEST. WILL ALSO KEEP CHC POPS GOING DUE TO A BAROCLINIC ZONE LINGERING OVER THE STATE IN THE COOL SECTOR. WITH COOLER TEMPS AND LITTLE INSTABILITY...DOWNPLAYED TSRA MENTION TO SHOWERS FRIDAY NIGHT. INSTABILITY INCREASES AGAIN LATER SATURDAY. MEDIUM MODEL RUNS BEGINNING TO SHOW SOME CONSENSUS OF THE FRONTAL BOUNDARY LIFTING NORTH AGAIN IN RESPONSE TO THE WESTERN STATES TROUGH DEEPENING AND EASTERN STATES UPPER RIDGE BUILDING. AGAIN ANOTHER WAVE WITH FRONTAL SYSTEM ATTEMPTS TO SLIDE OVER THE REGION LATER SUNDAY NIGHT INTO MONDAY FOR A FIRST STAB AT THE TIMING. WENT WITH COOLER TEMPS SATURDAY WITH LAGGING BAROCLINIC ZONE BUT WARMER SUNDAY MAX TEMPS AS UPPER HEIGHTS BUILD AND THE FRONT LIFTS NORTH AS A WARM FRONT. && .AVIATION...HIGH PRESSURE WILL MOVE ACROSS THE REGION OVER THE NEXT 24 HOURS. OTHER THAN AREAS OF FROST DEVELOPING LATE TONIGHT OVER PARTS OF CENTRAL AND MOST OF NORTH-CENTRAL WISCONSIN...A SCT MID-DECK WILL ARRIVE LATE TONIGHT INTO TOMORROW. MPC && .GRB WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY FROM 2 AM TO 7 AM CDT TUESDAY FOR WIZ005-010>013- 018-019-021. && $$ MPC/TDH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1256 AM CDT WED MAY 23 2012 ...AVIATION SECTION UPDATED... .SYNOPSIS... ISSUED AT 1218 PM CDT TUE MAY 22 2012 A 500MB UPPER TROUGH WAS LOCATED NEAR THE SOUTHWEST COAST OF BRITISH COLUMBIA AND NORTHWEST WASHINGTON AT 12Z TUESDAY. A 120-140KT UPPER LEVEL JET WAS PLACE NEAR AND JUST SOUTHWEST OF THE BASE OF THIS UPPER TROUGH. 90-110 METER HEIGHT FALLS WERE OBSERVED ACROSS EASTERN IDAHO AND WESTERN MONTANA. A WESTERLY FLOW EXTENDED ACROSS THE ROCKIES INTO THE WESTERN HIGH PLAINS WITH +12 TO +13C 700MB TEMPERATURES STRETCHING FROM EASTERN WYOMING/WESTERN NEBRASKA INTO NORTHEAST NEW MEXICO. UNDER THESE WARM 700MB TEMPERATURES AT THE SURFACE THERE WAS A TROUGH OF LOW PRESSURE ACROSS WESTERN NEBRASKA AND EXTREME EASTERN COLORADO/FAR WESTERN KANSAS. && .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 128 PM CDT TUE MAY 22 2012 RAP, NAM AND HRRR PLACE THE SURFACE TROUGH OF LOW PRESSURE NEAR THE COLORADO BORDER THIS EVENING. MODEL SOUNDINGS AT 00Z WEDNESDAYS IN THIS AREA INDICATING LITTLE TO NO CIN WITH A TEMPERATURES DRY ADIABATIC UP TO AROUND THE 600MB LEVEL WHERE SOME MOISTURE IS PRESENT. ALSO OBSERVING SOME INSTABILITY PRESENT AS WELL SO AM UNABLE TO COMPLETELY RULE OUT A EARLY EVENING THUNDERSTORM DEVELOPING NEAR THE COLORADO BORDER EARLY THIS EVENING. RAP AND HRRR DO HINT AT A FEW STORMS DEVELOPING AFTER 22Z NEAR THE ELKHART WHERE THE BETTER INSTABILITY ARE FORECAST TO BE LOCATED. WITH THIS IN MIND THE PREVIOUS PRECIPITATION FORECAST FOR EXTREME SOUTHWEST KANSAS STILL APPEARS TO BE ON TRACK. ALSO BASED ON THE INVERTED V TYPE OF SOUNDINGS IT DOES APPEAR THAT STRONG WINDS UP TO 60 OR 70 MPH WILL BE THE MAIN HAZARD. ANY STORM THAT DOES DEVELOP EARLY THIS EVENING IS EXPECTED TO END BEFORE MIDNIGHT BUT MAY MOVE AS FAR EAST AS LIBERAL IF THESE A COLD POOL CAN BE DEVELOPED FROM STORMS. AFTER MIDNIGHT SOUTH WINDS OF 15 TO 25 MPH ARE EXPECTED TO CONTINUE AND BASED ON TEMPERATURES EARLIER THIS MORNING WILL FAVOR OVERNIGHT LOWS AROUND 5F WARMER THAN GUIDANCE. ON WEDNESDAY A SURFACE TROUGH/DRYLINE WILL SLIDE EAST INTO WESTERN KANSAS DURING THE DAY AS A COLD FRONT DROPS SOUTH INTO NORTHWEST KANSAS BY LATE MORNING. THE COLD FRONT IS EXPECTED TO BE LOCATED FROM WEST CENTRAL KANSAS AND NORTH CENTRAL KANSAS BY THE MID AFTERNOON AS WARM MID LEVEL TEMPERATURES SPREADS EAST ACROSS SOUTHWEST KANSAS. MODEL SOUNDINGS INDICATING ANOTHER DAY OF GOOD MIXING AND BASED ON MODEL SOUNDINGS AT 00Z THURSDAY IT CURRENTLY APPEARS HIGHS AROUND 100 DEGREES WILL STILL BE POSSIBLE WEST OF THE DRYLINE. EAST OF THE DRYLINE AND NEAR THE COLD FRONT THE HIGHS WILL BE SLIGHTLY COOLER AND RANGE FROM THE LOW TO MID 90S. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 234 PM CDT TUE MAY 22 2012 WEDNESDAY NIGHT: A FRONTAL BOUNDARY COULD BE THE IMPETUS FOR CONVECTION WEDNESDAY NIGHT MAINLY ACROSS THE INTERSTATE 70 CORRIDOR. MARGINAL SURFACE DEWPOINTS IN THE 50S DEG F AND VERY WARM MAXIMUM TEMPERATURES IN THE 90S DEG F ACROSS CENTRAL KANSAS WILL CONTRIBUTE TO 1500 TO 2500 J/KG OF SBCAPE. AN 850 HPA THETA-E AXIS WILL ALSO EXIST ACROSS WEST CENTRAL KANSAS WITH BROAD SOUTHWESTERLY FLOW ALOFT WHICH POINT TO FAVORABLE CONDITIONS FOR CONVECTION. SEVERE WEATHER CANNOT BE RULED OUT WITH 40 TO 50 KT OF BULK 0 TO 6 KM SHEAR. THURSDAY: A BROAD 500 HPA TROUGH IS EXPECTED FROM THE PACIFIC NORTHWEST TOWARDS THE NORTHERN PLAINS. ANOTHER VORTMAX MOVING DOWNSTREAM WILL USHER IN A COLD FRONT EXTENDING FROM THE UPPER MIDWEST TO SOMEWHERE IN KANSAS. I SAY SOMEWHERE BECAUSE THERE IS PRETTY LARGE SPATIAL DIFFERENCES BETWEEN THE ECMWF/GFS. THIS IS PARTICULARLY TRUE WHEN THE FRONT RETURNS AS A WARM FRONT LATE THURSDAY. DECIDED TO TAKE THE MORE AGGRESSIVE ECMWF APPROACH WITH THE NORTHWARD PROGRESSION OF THIS WARM FRONT. SOUTH OF THIS FRONT, LOW LEVEL TEMPS ARE EXPECTED TO BE VERY WARM (30 DEG C @ 850 HPA/15 DEG C @ 700 HPA), SO HAVE KEPT LOWER 90S DEG F TOWARDS THE OKLAHOMA BORDER AND "COOLER" 80S DEG F ACROSS WEST CENTRAL KANSAS. NOT EXPECTING ANY CONVECTION AS A RESULT OF THE EML ADVECTION ACROSS SW KANSAS. FRIDAY: A WAA PATTERN WILL STRENGTHEN FRIDAY WITH THE EML SPREADING FURTHER NORTH AND 850 HPA TEMPERATURES WARMING TO 33 DEC C. 700 HPA TEMPERATURES WILL ALSO BE VERY WARM AND NEAR 16 DEG C. THERE MIGHT BE AN ISOLATED STORM NEAR HAYS FRIDAY EVENING, BUT AM DUBIOUS OF THIS GFS SOLUTION SO HAVE KEPT POPS IN SLIGHT CATEGORY GIVEN THE STOUT EML. THERE IS ALSO NOT MUCH IN THE WAY OF UPPER LEVEL SUPPORT AS 500 HPA HEIGHT INCREASES ARE EXPECTED ACROSS THE REGION ASSOCIATED WITH MID LEVEL SHORTWAVE RIDGING. TEMPERATURES WILL BE HOT AND IN THE 90S DEG F. IF THE ECMWF SOLUTION IS CORRECT, THEN A 100 DEGREE DAY IS POSSIBLE FOR SOME LOCATIONS AND TEMPERATURES NEED TO BE INCREASED IN THE FUTURE. SATURDAY AND BEYOND: FOLLOWED THE ECMWF SOLUTION FOR THIS PERIOD. A VERY BROAD MID LEVEL TROUGH IS EXPECTED ACROSS THE GREAT BASIN. ANY JET LEVEL DYNAMICS LOOK TO REMAIN WELL NORTH OF KANSAS WITH GREATEST CHANCE OF HIGHER IMPACT SEVERE WEATHER NORTH OF THE REGION. THERE COULD BE SOME STORMS ACROSS SOUTHWEST KANSAS THROUGH THE WEEKEND, HOWEVER, THE ATMOSPHERE LOOKS PRETTY CAPPED. MADE A FEW TWEAKS TO THE ALLBLEND POPS (CLEANED UP) AND WARMED TEMPERATURES UP WITH A BIAS TOWARDS THE ECMWF. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1254 AM CDT WED MAY 23 2012 A COLD FRONT EXTENDED FROM EASTERN NORTH DAKOTA TO A LOW PRESSURE SYSTEM IN NORTHEAST COLORADO AT 05Z. THIS FRONT WILL CONTINUE TO MOVE SOUTHEAST AS AN UPPER LEVEL TROUGH PROPAGATES NORTH DAKOTA INTO MANITOBA THIS MORNING. ANOTHER STRONG UPPER LEVEL TROUGH THAT WAS IN WESTERN IDAHO AT 05Z WILL MOVE INTO WESTERN NEBRASKA BY 00Z THURSDAY. THE LOW PRESSURE SYSTEM IN NORTHEAST COLORADO WILL DEVELOP SOUTHWARD IN THE LEE OF THE ROCKIES TODAY AND WILL BE CENTERED NORTH OF ELKHART BY LATE AFTERNOON. THE SURFACE COLD FRONT WILL EXTEND FROM SOUTHEAST NEBRASKA TO THE LOW PRESSURE SYSTEM NORTH OF ELKHART BY 00Z AND WILL SURGE SOUTHWARD AS THE SURFACE LOW PROPAGATES INTO EASTERN KANSAS BY 12Z THURSDAY. VFR CONDITIONS WILL PREVAIL FOR MOST OF THE DAY WITH ONLY SCATTERED CIRRIFORM CLOUDS AOA 250. VERY WARM AIR IN THE MID LEVELS OF THE ATMOSPHERE WILL PRECLUDE DEVELOPMENT OF THUNDERSTORMS MOST OF TODAY. THE EDGE OF THE EXTREMELY WARM AIR ALOFT WILL BE OVER NORTHERN KANSAS LATE THIS AFTERNOON, AND CONVERGENCE ALONG THE COLD FRONT ALONG WITH A WEAKER CAPPING INVERSION WILL RESULT IN DEVELOPMENT OF SCATTERED THUNDERSTORMS NEAR HYS AFTER 22Z. THE THUNDERSTORMS WILL MOVE NORTHEAST INTO NORTH CENTRAL KANSAS AND SOUTHERN NEBRASKA BY 03Z. AN AREA OF LOW CLOUDS WITH CEILINGS 020-030 WILL DEVELOP TONIGHT BEHIND THE COLD FRONT AS IT SURGES SOUTHWARD. && .PRELIMINARY POINT TEMPS/POPS... DDC 63 86 64 94 / 10 10 10 10 GCK 58 85 61 92 / 10 10 10 10 EHA 58 91 60 96 / 10 10 10 10 LBL 61 89 64 96 / 10 10 10 10 HYS 61 83 62 90 / 20 10 10 20 P28 70 89 68 96 / 10 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BURGERT SHORT TERM...BURGERT LONG TERM...SUGDEN AVIATION...RUTHI
AREA FORECAST DISCUSSION
NWS CARIBOU ME
119 AM EDT WED MAY 23 2012 .SYNOPSIS... A WEAKENING COLD FRONT WILL CROSS THE STATE OVERNIGHT. AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL BUILD BACK OVER THE STATE ON WEDNESDAY AND REMAIN OVER THE REGION THROUGH FRIDAY.&& .NEAR TERM /THROUGH TODAY/... UPDATE 0115L: RAIN SHOWER ACTIVITY ACROSS THE N CONTS TO GRADUALLY DECREASE IN COVERAGE AS FCST AND SHOULD DIMINISH/MOVE OUT OF THE AREA NEXT FEW HRS. FCST PRETTY MUCH ON TRACK W/ NO MAJOR ADJUSTMENTS NEEDED ATTM... 950 PM UPDATE: WHATS LEFT OF THE LLVL MOISTURE FLUX CNVRG ALG A WEAKENING COLD FRONT IS ENDING...ALLOWING HEAVIER SHWRS TO FINALLY REDUCE HRLY RNFL RATES INTO THE MDT AND LGT CTGRY. HRRR GUIDANCE ALG WITH OTHER LARGER DOMAIN SYNOPTIC SCALE MODELS ALSO SHOW THIS DIMINISHING TREND...BOTH IN INTENSITY AND CVRG...CONTG INTO THE LATE NGT HRS...SO ADDITIONAL HVY RNFL APPEARS VERY LIKELY ATTM. OUTSIDE OF EXTENDING SIG 00-06Z QPF AND CORRESPONDING POPS SE A LITTLE FROM THE LAST UPDATE TO INCLUDE PRESQUE ISLE...WE LOADED OBSVD 2000 LDT SFC TEMPS AND MERGED THEM TO FCST OVRNGT LOWS AT 0500 LDT WED MORN. NO OTHER CHGS NEEDED TO THE REMAINING FCST ELEMENTS FOR THE NEAR TERM ATTM. 530 PM UPDATE: UPDATED POPS TO CORRESPOND TO THE AXIS OF HEAVIEST SHWRS OVR FAR NRN PTNS OF THE FA ATTM. RADAR INDICATES THE HEAVIEST RADAR ESTIMATED RNFL ATTM BETWEEN NINE MILE BRIDGE AND CLAYTON LAKE OF NW AROOSTOOK COUNTY. OTHER NARROW BANDS OF 1 INCH PLUS RNFL ARE NEAR STOCKHOLM AND NEW CANADA OF NE AND N CNTRL AROOSTOOK COUNTY. MOVEMENT OF THIS LINE OF HVY RN SHWRS...WHICH ATTM IS TO LOW TOP FOR LGTNG IS MOVING WITH THE SLOWER SPEED ASSOCIATED WITH BACKWARD CORFIDI VECTOR MOTION WHICH ATTM IS FROM THE S AT 5 TO 10 KT. THIS MOTION SHOULD INCREASE LATER THIS EVE TO 10 TO 15 KT. THIS FASTER MOTION WITH LESS INTENSE REFS SHOULD DECREASE ANY CONCERNS OF MINOR LOCALIZED FLOODING BY THIS TM. OTHERWISE...WE LOADED OBSVD 1700 LDT SFC TEMPS AND MERGED THEM TO FCST OVRNGT LOWS AT 0500 LDT WED MORN. ORGNL DISC: WEAK LOW PRESSURE SOUTH OF THE GULF OF MAINE AND THE COLD FRONT SLOWLY MOVING OUT OF QUEBEC INTO NW MAINE WILL COMBINE TO PRODUCE CLOUDY CONDITIONS AND SHOWERS. MOST OF THE SHOWER ACTIVITY WILL BE FOCUSED ALONG THE FRONT IN ZONES 1 THROUGH 4 LATE THIS AFTERNOON AND EVENING. SOME OF THESE SHOWERS COULD BE HEAVY TOWARDS THE SJV TONIGHT WITH SLOW STORM MOTIONS ALONG THE FRONTAL BOUNDARY. A RUMBLE OF THUNDER IS POSSIBLE WITH SOME RELATIVELY WEAK ELEVATED CONVECTION AND THE ENTRANCE REGION TO A WEAK UPPER JET. SOUTH OF THE SJV...PRECIP AMOUNTS ARE EXPECTED TO TAPER TOWARDS A QUARTER INCH NEAR CARIBOU...LESS THAN A TENTH OF AN INCH NEAR HOULTON AND JUST A FEW HUNDREDTHS OF AN INCH TOWARDS BANGOR. THE BIGGEST ISSUE DOWN EAST WILL BE FOG CREEPING BACK NORTHWARD FROM THE GULF OF MAINE TOWARDS THE FRONT. WITH CLOUD COVER AND SHOWERS...LOWS TONIGHT WILL ONLY DROP INTO THE UPPER 50S EXCEPT SOME LOWER 50S ALONG THE COAST. THE FRONT WILL SLOWLY REACH DOWN EAST BY WEDNESDAY MORNING. THE CROWN OF MAINE WILL QUICKLY CLEAR OUT AND EXPERIENCE SUNSHINE WITH LOW HUMIDITY. CLOUD COVER AND HIGHER HUMIDITY WILL LINGER DOWN EAST THROUGH THE MORNING WITH A FEW SHOWERS. CLEARING SKIES SHOULD PUSH SOUTHWARD INTO DOWN EAST ZONES DURING THE AFTERNOON. HIGHS WILL REACH THE LOW 70S IN THE NORTHERN HALF OF THE FORECAST AREA AND MID 70S FOR MOST OF DOWN EAST EXCEPT THE COAST WHERE UPPER 60S TO LOW 70S ARE EXPECTED. && .SHORT TERM /TONIGHT THROUGH 6 PM THURSDAY/... A LARGE UPPER LEVEL RIDGE OF HIGH PRESSURE WILL BUILD BACK OVER THE STATE ON WEDNESDAY BRINGING MORE WARM WEATHER WHICH WILL LAST THROUGH THE END OF THE WEEK. A SOUTHERLY FLOW RESULTING FROM HIGH PRESSURE OFF TO THE EAST COMBINED WITH LOW PRESSURE LIFTING INTO THE GREAT LAKES STATES WILL ALSO BRING INCREASING HUMIDITY. THURSDAY WILL BRING PARTIAL SUNSHINE WITH A WARM AFTERNOON. SOME ISOLATED SHOWERS AND POSSIBLY A STRAY THUNDERSTORM MAY AFFECT WESTERN AREAS THURSDAY AFTERNOON AS MOISTURE LIFTS NORTH AROUND THE ATLANTIC HIGH. THURSDAY NIGHT WILL BE PARTLY CLOUDY. HUMID AIR WILL RESULT IN A WARM NIGHT. A SOUTHERLY BREEZE WILL INCREASE ON FRIDAY AS THE GRADIENT TIGHTENS AHEAD OF AN APPROACHING COLD FRONT. THE DAY WILL BE PARTLY SUNNY AND WARM AND A STRAY SHOWER OR THUNDERSHOWER WILL BE POSSIBLE IN SOME WESTERN AND SOUTHERN SPOTS. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... MODELS IN FAIRLY GOOD AGREEMENT WITH COLD FRONT CROSSING THE STATE FRIDAY NIGHT WITH SHOWERS MAINLY ACROSS NORTHERN SECTIONS. HIGH PRESSURE CENTERED OVER JAMES BAY WILL THEN BUILD ACROSS THE REGION SATURDAY THROUGH SUNDAY WITH FAIR CONDITIONS. GFS IS INDICATING WEAK IMPULSE COULD PROVIDE SHOWERS ACROSS THE AREA LATE SUNDAY BUT OTHER MODELS FARTHER SOUTH WITH THIS FEATURE SO FOR NOW WILL KEEP SHOWERS EITHER CHANCE OR SLIGHT CHANCE AND CONFINED TO NORTHWEST SECTIONS AND DOWNEAST. AT THIS TIME, MEMORIAL DAY LOOKS TO BE DRY WITH NEXT LOW PRESSURE AFFECTING THE REGION MONDAY NIGHT INTO TUESDAY. && .AVIATION /05Z WEDNESDAY THROUGH SUNDAY/... NEAR TERM: MOIST AIRMASS AHEAD OF THE COLD FRONT WILL BRING ALL TERMINALS TO IFR TONIGHT WITH VLIFR POSSIBLE CLOSER TO THE COAST FOR LOCATIONS SUCH AS BHB AND BGR. THE COLD FRONT WILL BRING CONDITIONS TO VFR NORTH OF HUL WEDS MORNING AND VFR IS EXPECTED TO REACH BGR AND BHB BY MIDDAY. SHORT TERM: GENERALLY VFR CONDITIONS ARE EXPECTED WEDNESDAY NIGHT THROUGH FRIDAY ALTHOUGH SOME PATCHY LOW CLOUDS OR FOG MAY BRIEFLY LOWER CONDITIONS TO IFR EARLY THURSDAY MORNING OR FRIDAY MORNING. EXPECT VFR CONDITIONS FRIDAY NIGHT THROUGH SUNDAY. && .MARINE... NEAR TERM: UPDATE...BASED ON LATEST BUOY OBS WHICH ONLY SHOW WV HTS OF ARND 3 FT ON BUOYS OVR AND NEAR OUR OUTER MZS...WE OPTD TO PUSH BACK THE BEGINNING OF THE SCA FOR HAZ SEAS OVR THE OUTER MZS UNTIL 0400 AM LDT. ORGNL DISC...A SE SWELL WILL BRING LONG PERIOD WAVE HTS TO 6 FEET IN THE OUTER WATERS...MEETING SCA CRITERIA FOR HAZARDOUS SEAS. WILL ISSUE SCA FOR 11PM TONIGHT THROUGH WEDNESDAY AFTERNOON. WINDS WILL REMAIN LIGHT. SHORT TERM: WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA LEVELS WEDNESDAY NIGHT THROUGH FRIDAY. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ050-051. && $$ NEAR TERM...KHW/VJN/MCW SHORT TERM...BLOOMER LONG TERM...FOSTER AVIATION...KHW MARINE...KHW/VJN/MCW/BLOOMER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
540 AM EDT WED MAY 23 2012 .SYNOPSIS... ISSUED AT 528 AM EDT WED MAY 23 2012 WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM THE GULF OF ALASKA INTO THE NW CONUS AND A FLAT DOWNSTREAM RIDGE FROM THE SRN PLAINS TO THE UPPER MS VALLEY RESULTING IN WRLY FLOW THROUGH THE NRN GREAT LAKES. AT THE SFC...A RIDGE EXTENDED FROM JAMES BAY THROUGH ERN LAKE SUPERIOR AND LAKE MI INTO THE MID MS VALLEY. SRLY WINDS WERE INCREASING FROM THE PLAINS INTO MN AHEAD OF LOW PRES OVER THE WRN DAKOTAS. RADAR AND SFC OBS INDICATED AN AREA OF MAINLY VIRGA/-SHRA/SPRINKLES OVER WRN UPPER MI SUPPORTED BY 305K-310K ISENTROPIC LIFT. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 528 AM EDT WED MAY 23 2012 TONIGHT...EXPECT THAT THE -SHRA/SPRINKLES WILL CONTINUE TO DIMINISH AS THEY MOVE TO THE EAST LATE THIS AFTERNOON AND EVENING. WITH THE INCREASED CLOUD COVER AND SOUTHERLY WINDS TONIGHT...TEMPS WILL ONLY DROP OFF INTO THE MID 40S INLAND AND LOWER TO MID 50S FOR DOWNSLOPE LOCATIONS OVER THE WEST HALF. WEDNESDAY...AS THE HIGH OVER THE LAKE AND THE PLAINS TROUGH SHIFTS TO THE EAST...THE GRADIENT WILL INCREASE ACROSS UPPER MICHIGAN. THE MODELS WERE IN GOOD AGREEMENT IN KEEPING THE MOISTURE/LIFT AHEAD OF THE MID LEVEL AND SFC TROUGH TO THE WEST...GRADUALLY SHIFTING INTO WRN LAKE SUPERIOR LATE. WITH THE WAA AND SUNSHINE...TEMPS SHOULD CLIMB INTO THE MID AND UPPER 70S INLAND WITH COOLER READINGS NEAR LAKE MICHIGAN. MIXING SHOULD ALSO ALSO A DECENT PORTION OF THE 25-30 KT SRLY 925 MB WINDS TO MIX TO THE SFC. INCREASED WILDFIRE DANGER IS EXPECTED WITH THE COMBINATION OF 15 TO 20 MPH SFC WINDS AND GUSTS TO 30 MPH ALONG WITH RH VALUES DROPPING TO AROUND 30 PERCENT. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 528 AM EDT WED MAY 23 2012 WENT WARMER /ABOUT 5F/ AND WINDIER FOR FRIDAY. WHILE MUCH OF THE WARMER AIR AND PRECIP WILL EXIT EAST WITH THE COLD FRONT EXITING EAST IN THE MORNING...THE SFC TROUGH WILL LINGER OVERHEAD WITH WSW WINDS AT THE SFC. EXPECT 850MB TEMPS TO FALL FROM THE MID TEENS C TO AROUND 10C AROUND DAYBREAK FRIDAY...AND REMAIN STEADY AROUND THIS LEVEL THROUGH SATURDAY. COULD NOT GET RID OF PRECIPITATION ALL TOGETHER FOR...GIVEN 120KT 250MB JET STREAMING ACROSS UPPER MICHIGAN...AND A KICKER OF A SHORTWAVE ALOFT. THERE IS SIGNIFICANT TIMING/STRENGTH DIFFERENCES WITH THIS FEATURE. AS A RESULT...THE CHANCE OF PRECIP/TS WAS LIMITED TO SLIGHT CHANCE. THE 23/00Z GFS DOES SHOW AROUND A QUARTER OF AN INCH OF LIQUID CENTRAL DURING THE AFTERNOON HOURS...WHILE THE OTHER MODELS ARE MUCH DRIER. ALTHOUGH HIGH PRESSURE FROM CENTRAL CANADA WILL ATTEMPT TO SINK ACROSS THE UPPER GREAT LAKES FOR SATURDAY...IT WILL BE PUSHED EASTWARD...SKIMMING NORTHERN AND EASTERN UPPER MI SATURDAY INTO SATURDAY NIGHT. MUCH OF THIS WILL BE DUE TO THE NEXT LOW DEVELOPING OVER THE CENTRAL STATES. THE LOW WILL MOVE TO THE DAKOTAS/NE BY SUNDAY AFTERNOON...WITH A WARM FRONT QUICKLY PUSHING UP ACROSS THE CWA AND 850MB TEMPS JUMPING TO AROUND 18C SUNDAY NIGHT INTO MONDAY MORNING. THE 23/00Z GFS IS MORE PROGRESSIVE WITH THE SFC LOW...AVERAGING OUT TO BE ABOUT 6 HOURS QUICKER THAN THE 23/00Z ECMWF FROM SATURDAY NIGHT THROUGH EARLY MONDAY AFTERNOON. THE SLOW MOVING SYSTEM WILL CONTINUE TO INFLUENCE OUR WEATHER THROUGH THE START OF THE NEXT WORK WEEK...WITH A CHANCE OF SHOWERS LINGERING THROUGH MONDAY. TEMPERATURES WILL EVENTUALLY COOL TUESDAY...BACK TO BELOW NORMAL READINGS /MAINLY IN THE 50S TO MID 60S/. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 539 AM EDT WED MAY 23 2012 STRONG WINDS WILL BE THE MAIN CONCERN OVER THE NEXT 24 HOURS...OUT OF A SOUTHERLY DIRECTION...AHEAD OF LOW PRESSURE STRETCHING FROM S CENTRAL CANADA THROUGH THE CENTRAL PLAINS STATES. LLWS AT NIGHT WILL BE LIKELY AT ALL 3 SITS...EVEN WITH IWD LIKELY KEEPING GUSTS AT OR ABOVE 20KTS THROUGH THE OVERNIGHT HOURS. OTHERWISE...VFR CEILINGS AND VIS SHOULD REMAIN...WITH ONLY A SMALL CHANCE OF SHOWERS AND/OR THUNDERSTORMS GETTING TO IWD BY 12Z THURSDAY. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 528 AM EDT WED MAY 23 2012 LOW PRESSURE OVER S MANITOBA WILL PUSH INTO ONTARIO TONIGHT AND THURSDAY...AS AN ADDITIONAL LOW MOVES FROM THE CENTRAL PLAINS TO W LS FRIDAY AFTERNOON. EXPECT THE LOW TO CONTINUE A NE TRACK ACROSS ONTARIO THROUGH FRIDAY...WITH A TROUGH LINGERING ACROSS LAKE SUPERIOR. STRENGTHENING S WINDS WILL BE THE RULE AHEAD OF THIS SYSTEM TODAY THROUGH TOMORROW...STRONGEST ACROSS THE TALLER OBSERVING PLATFORMS ACROSS CENTRAL LS. HIGH PRESSURE OVER CENTRAL CANADA FRIDAY NIGHT WILL SLIDE ACROSS ONTARIO SATURDAY...BEFORE SETTLING ACROSS HUDSON BAY ON SUNDAY. AS A RESULT...A RIDGE WILL SLIDE ACROSS LS SATURDAY...WITH LIGHTER WINDS TAKING HOLD. A LOW ACROSS THE CENTRAL PLAINS WILL FILL ACROSS MN SUNDAY INTO SUNDAY NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...KC SHORT TERM...KC LONG TERM...KF AVIATION...KF MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
529 AM EDT WED MAY 23 2012 .SYNOPSIS... ISSUED AT 528 AM EDT WED MAY 23 2012 WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM THE GULF OF ALASKA INTO THE NW CONUS AND A FLAT DOWNSTREAM RIDGE FROM THE SRN PLAINS TO THE UPPER MS VALLEY RESULTING IN WRLY FLOW THROUGH THE NRN GREAT LAKES. AT THE SFC...A RIDGE EXTENDED FROM JAMES BAY THROUGH ERN LAKE SUPERIOR AND LAKE MI INTO THE MID MS VALLEY. SRLY WINDS WERE INCREASING FROM THE PLAINS INTO MN AHEAD OF LOW PRES OVER THE WRN DAKOTAS. RADAR AND SFC OBS INDICATED AN AREA OF MAINLY VIRGA/-SHRA/SPRINKLES OVER WRN UPPER MI SUPPORTED BY 305K-310K ISENTROPIC LIFT. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 528 AM EDT WED MAY 23 2012 TONIGHT...EXPECT THAT THE -SHRA/SPRINKLES WILL CONTINUE TO DIMINISH AS THEY MOVE TO THE EAST LATE THIS AFTERNOON AND EVENING. WITH THE INCREASED CLOUD COVER AND SOUTHERLY WINDS TONIGHT...TEMPS WILL ONLY DROP OFF INTO THE MID 40S INLAND AND LOWER TO MID 50S FOR DOWNSLOPE LOCATIONS OVER THE WEST HALF. WEDNESDAY...AS THE HIGH OVER THE LAKE AND THE PLAINS TROUGH SHIFTS TO THE EAST...THE GRADIENT WILL INCREASE ACROSS UPPER MICHIGAN. THE MODELS WERE IN GOOD AGREEMENT IN KEEPING THE MOISTURE/LIFT AHEAD OF THE MID LEVEL AND SFC TROUGH TO THE WEST...GRADUALLY SHIFTING INTO WRN LAKE SUPERIOR LATE. WITH THE WAA AND SUNSHINE...TEMPS SHOULD CLIMB INTO THE MID AND UPPER 70S INLAND WITH COOLER READINGS NEAR LAKE MICHIGAN. MIXING SHOULD ALSO ALSO A DECENT PORTION OF THE 25-30 KT SRLY 925 MB WINDS TO MIX TO THE SFC. INCREASED WILDFIRE DANGER IS EXPECTED WITH THE COMBINATION OF 15 TO 20 MPH SFC WINDS AND GUSTS TO 30 MPH ALONG WITH RH VALUES DROPPING TO AROUND 30 PERCENT. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 528 AM EDT WED MAY 23 2012 WENT WARMER /ABOUT 5F/ AND WINDIER FOR FRIDAY. WHILE MUCH OF THE WARMER AIR AND PRECIP WILL EXIT EAST WITH THE COLD FRONT EXITING EAST IN THE MORNING...THE SFC TROUGH WILL LINGER OVERHEAD WITH WSW WINDS AT THE SFC. EXPECT 850MB TEMPS TO FALL FROM THE MID TEENS C TO AROUND 10C AROUND DAYBREAK FRIDAY...AND REMAIN STEADY AROUND THIS LEVEL THROUGH SATURDAY. COULD NOT GET RID OF PRECIPITATION ALL TOGETHER FOR...GIVEN 120KT 250MB JET STREAMING ACROSS UPPER MICHIGAN...AND A KICKER OF A SHORTWAVE ALOFT. THERE IS SIGNIFICANT TIMING/STRENGTH DIFFERENCES WITH THIS FEATURE. AS A RESULT...THE CHANCE OF PRECIP/TS WAS LIMITED TO SLIGHT CHANCE. THE 23/00Z GFS DOES SHOW AROUND A QUARTER OF AN INCH OF LIQUID CENTRAL DURING THE AFTERNOON HOURS...WHILE THE OTHER MODELS ARE MUCH DRIER. ALTHOUGH HIGH PRESSURE FROM CENTRAL CANADA WILL ATTEMPT TO SINK ACROSS THE UPPER GREAT LAKES FOR SATURDAY...IT WILL BE PUSHED EASTWARD...SKIMMING NORTHERN AND EASTERN UPPER MI SATURDAY INTO SATURDAY NIGHT. MUCH OF THIS WILL BE DUE TO THE NEXT LOW DEVELOPING OVER THE CENTRAL STATES. THE LOW WILL MOVE TO THE DAKOTAS/NE BY SUNDAY AFTERNOON...WITH A WARM FRONT QUICKLY PUSHING UP ACROSS THE CWA AND 850MB TEMPS JUMPING TO AROUND 18C SUNDAY NIGHT INTO MONDAY MORNING. THE 23/00Z GFS IS MORE PROGRESSIVE WITH THE SFC LOW...AVERAGING OUT TO BE ABOUT 6 HOURS QUICKER THAN THE 23/00Z ECMWF FROM SATURDAY NIGHT THROUGH EARLY MONDAY AFTERNOON. THE SLOW MOVING SYSTEM WILL CONTINUE TO INFLUENCE OUR WEATHER THROUGH THE START OF THE NEXT WORK WEEK...WITH A CHANCE OF SHOWERS LINGERING THROUGH MONDAY. TEMPERATURES WILL EVENTUALLY COOL TUESDAY...BACK TO BELOW NORMAL READINGS /MAINLY IN THE 50S TO MID 60S/. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 712 PM EDT TUE MAY 22 2012 WARM ADVECTION MID CLOUDS SHOULD GRADUALLY LIFT NORTH LATE TONIGHT WITH THE MVMT OF A WARM FRONT NORTH INTO CANADA. EXPECT VFR CONDITIONS TO PREVAIL WITH PLENTY OF LLVL DRY AIR THROUGH THE FCST PD. TNGT...EXPECT LLWS AT BOTH KIWD AND KCMX UNDER A TIGHTENING SRLY PRES GRADIENT AHEAD OF LOW PRES SYSTEM OVER THE NORTHERN PLAINS. DAYTIME HEATING AND MIXING WILL ALLOW FOR STRONGER SRLY WINDS TO REACH THE SFC...GUSTING AOA 25 AT BOTH KIWD AND KSAW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 528 AM EDT WED MAY 23 2012 LOW PRESSURE OVER S MANITOBA WILL PUSH INTO ONTARIO TONIGHT AND THURSDAY...AS AN ADDITIONAL LOW MOVES FROM THE CENTRAL PLAINS TO W LS FRIDAY AFTERNOON. EXPECT THE LOW TO CONTINUE A NE TRACK ACROSS ONTARIO THROUGH FRIDAY...WITH A TROUGH LINGERING ACROSS LAKE SUPERIOR. STRENGTHENING S WINDS WILL BE THE RULE AHEAD OF THIS SYSTEM TODAY THROUGH TOMORROW...STRONGEST ACROSS THE TALLER OBSERVING PLATFORMS ACROSS CENTRAL LS. HIGH PRESSURE OVER CENTRAL CANADA FRIDAY NIGHT WILL SLIDE ACROSS ONTARIO SATURDAY...BEFORE SETTLING ACROSS HUDSON BAY ON SUNDAY. AS A RESULT...A RIDGE WILL SLIDE ACROSS LS SATURDAY...WITH LIGHTER WINDS TAKING HOLD. A LOW ACROSS THE CENTRAL PLAINS WILL FILL ACROSS MN SUNDAY INTO SUNDAY NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...KC SHORT TERM...KC LONG TERM...KF AVIATION...VOSS MARINE...KF
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
200 AM EDT WED MAY 23 2012 .SYNOPSIS... HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT AND THEN WEAKEN WEDNESDAY NIGHT. A WARM FRONT WILL MOVE ACROSS THE AREA THURSDAY. A WEAK COLD FRONT WILL MOVE IN FRIDAY AND THEN MOVE BACK NORTH AS A WARM FRONT SATURDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... SATELLITE SHOWING THE CONTINUED CLEARING TREND ACROSS THE AREA. TEMPS FALLING AS ANTICIPATED WITH DEWPOINTS IN THE LOWER 50S. SOME MODELS CONTINUING TO INDICATE FOG DEVELOPING OVERNIGHT. SOME MODELS SUCH AS THE HRRR NOT INDICATING WIDESPREAD FOG WHILE LATEST LAMP GUIDANCE STILL SHOWING FOG ACROSS THE AREA. WITH RECENT RAINFALL BEING MORE ISOLATED ACROSS THE AREA THERE ISN/T AN ABUNDANT AMOUNT OF SFC MOISTURE TO AID FOR FOG DEVELOPMENT. ONLY CHANGE TO FORECAST WAS THE REMOVAL OF THE TERM DENSE TO THE FOG OVERNIGHT...BUT DID CONTINUE TO MENTION IT. AT THIS TIME WILL NOT ISSUE ANY ADVISORIES GIVEN MARGINAL CONFIDENCE ON LOCATION AND INTENSITY OF FOG ACROSS THE AREA. PREVIOUS DISCUSSION BELOW. A HIGH PRESSURE RIDGE WILL BE MOVING INTO THE AREA TONIGHT. THE BIG QUESTION IS HOW MUCH FOG WILL FORM. SOME OF THE MODELS ARE INDICATING WIDESPREAD DENSE FOG DEVELOPING. ON THE EDGE ABOUT THAT SINCE WE DID NOT HAVE WIDESPREAD RAIN AND DRIER AIR WILL DRY TO MOVE IN...HOWEVER...WE WILL NOT HAVE MUCH SUNSHINE BEFORE SUNSET OVER NORTHEAST OHIO AND NORTHWEST PA TO DRY THINGS OUT. WILL MENTION AREAS OF DENSE FOG AND HAVE THE NEXT SHIFT MONITOR FOR A POSSIBLE DENSE FOG ADVISORY. USED A MIX OF THE MOS GUIDANCE FOR THE LOWS. THE NAM GUIDANCE SEEMS TOO WARM OVER NORTHWEST OHIO BASED ON CLEARING SKIES AND LIGHT WINDS. && .SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/... THE SHORT TERM WILL BE MAINLY DRY BUT THERE WILL BE A LOW THREAT OF SHOWERS AND THUNDERSTORMS AT TIMES AND IN VARYING LOCATIONS. THE RIDGE WILL BE OVER THE AREA ON WEDNESDAY WITH PARTLY TO MOSTLY SUNNY SKIES. THE UPPER LOW OVER THE CAROLINAS MAY TRY TO MOVE SOME SHOWERS AND THUNDERSTORMS TO NORTHEAST OH...BUT WILL KEEP IT DRY ATTM. A WARM FRONT WILL MOVE ACROSS THE AREA THURSDAY...GOING WITH SLIGHT CHANCE POPS AS CONFIDENCE IS LOW AND THEN SLIGHT CHANCE POPS FRIDAY AND FRIDAY NIGHT AS WEAK COLD FRONT MOVES ACROSS THE AREA. USED A MIX OF GUIDANCE FOR THE TEMPERATURES. && .LONG TERM /SATURDAY THROUGH TUESDAY/... NO CHANGES TO THE HOLIDAY WEEKEND FORECAST. FRONTAL BOUNDARY WILL BE IN THE VICINITY SATURDAY...BUT WILL PUSH NORTH OF THE AREA BY SUNDAY. MONDAY WE WILL BE SITTING HIGH AND DRY UNDER HIGH PRESSURE. A COLD FRONT SLIPS THROUGH TUESDAY. H8 TEMPS PUSH +20C AND SURFACE TEMPS WILL BE FLIRTING WITH 90...ESPECIALLY SUNDAY AND MONDAY. SATURDAYS HIGHS MAY BE LIMITED SOME BY THE FRONT BEING NEARBY...BUT STILL BE ABOVE NORMAL. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... CEILINGS AND VISIBILITIES ARE ON THEIR WAY DOWN AT THIS TIME FROM CLEVELAND TO MANSFIELD EAST. I THINK WE WILL SEE A WIDESPREAD AREA OF STRATUS AND FOG BY SUNRISE THIS MORNING. SO WILL MENTION THIS ACCORDINGLY IN THE TAFS THIS MORNING. FOG AND STRATUS WILL BURN OFF THIS MORNING AND GIVE WAY TO VFR AGAIN. LAKE BREEZE WILL DEVELOP ALONG THE LAKE SHORE AT ERIE AND CLEVELAND. SOME FAIR WEATHER CUMULUS WILL DEVELOP INLAND SOUTH OF THE LAKE BREEZE. NOW THE OTHER PROBLEM WE HAVE TO CONTEND WITH IS WHETHER WE WILL SEE A THREAT FOR AN ISOLATED SHOWER OR THUNDERSTORM DEVELOP SOUTH OF THE LAKE BREEZE AND OVER EXTREME EASTERN PORTIONS OF THE FORECAST AREA. WE THINK IT SHOULD BE SO ISOLATED THAT IT MAY NOT AFFECT ANY TAF SITES. HOWEVER...AVIATION INTERESTS SHOULD KEEP IN MIND THE POSSIBILITY THAT THERE MAY BE ONE OR TWO AROUND TO AFFECT OPERATIONS. WINDS GO LIGHT AND VARIABLE AGAIN TONIGHT WITH POSSIBILITY FOR SOME MVFR MIST. .OUTLOOK...NON-VFR POSSIBLE IN MORNING BR/FG. && .MARINE... HIGH PRESSURE WILL BUILD OVER LAKE ERIE TONIGHT WITH LIGHT LAKE BREEZES AND GOOD MARINE CONDITIONS EXPECTED ON WEDNESDAY. SOUTHERLY FLOW WILL DEVELOP LATE THURSDAY INTO FRIDAY AHEAD OF A LOW PRESSURE SYSTEM TRACKING NORTHEAST THROUGH THE WESTERN AND UPPER GREAT LAKES. THIS SYSTEM WILL PUSH A WEAK FRONTAL BOUNDARY SOUTH TOWARDS LAKE ERIE ON FRIDAY NIGHT...STALLING IN THE VICINITY OF THE LAKE ON SATURDAY. LIGHT SOUTHERLY FLOW WILL DEVELOP AGAIN BY SUNDAY WITH WELL ABOVE NORMAL TEMPERATURES AND STABLE CONDITIONS EXPECTED FOR THE HOLIDAY WEEKEND. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KIELTYKA NEAR TERM...ABE/KIELTYKA SHORT TERM...KIELTYKA LONG TERM...OUDEMAN AVIATION...LOMBARDY MARINE...KEC
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1115 PM CDT TUE MAY 22 2012 .DISCUSSION.../ISSUED AT 900 PM CDT/ MAIN ISSUE OVER THE NEXT 18 HOURS IS THE CONVECTIVE CHANCES WITH THE SURFACE COLD FRONT. CURRENTLY A BROKEN LINE OF CONVECTION EXTENDS FROM NEAR ABERDEEN TO WINNER SOUTH DAKOTA. WHILE STORMS INITIALLY DEVELOPED ALONG THE SURFACE FRONT...THE STRONG LOW LEVEL WINDS HAVE RESULTED IN STORM MOTIONS THAT MOVE THEM AWAY FROM THE BOUNDARY. AS A RESULT...UPDRAFTS CONTINUE TO WEAKEN ONCE THE STORMS MOVE INTO THE MORE STABLE AIR MASS OVER SOUTHEAST SOUTH DAKOTA. WITH LITTLE UPPER LEVEL FORCING FOR ASCENT IN THE NEXT HOUR OR TWO...SEVERE WEATHER APPEARS UNLIKELY ALTHOUGH WITH 60 KT WINDS AT 850 MB...A SEVERE WIND GUST OR QUARTER SIZE HAIL MAY STILL BE POSSIBLE. EXPECTATION IS THESE STORMS WILL LIKELY SLOWLY WEAKEN OVER NEXT 3 OR 4 HOURS...ESPECIALLY SOUTH OF I-90 WHERE LOSS OF SURFACE HEATING WILL ONLY STRENGTHEN CAP. HOWEVER...BOTH RAP AND NAM SHOW ANOTHER WEAK WAVE WITH ASSOCIATED COOLING AT MID LEVELS MOVING INTO CENTRAL SD AROUND 09Z. THESE MODELS ALONG WITH HRRR ALL PRODUCE MORE CONVECTION AHEAD THE SURFACE COLD FRONT WHICH IS EXPECTED TO BE BETWEEN 9V9 AND MHE. WITH THE COLD ADVECTION AND WEAK MIDLEVEL ASCENT...THIS IS EXPECTED TO BE ENOUGH TO ERODE THE CAP AHEAD OF THE LATER TONIGHT. AM A LITTLE CONCERNED THAT MODELS MAY BE OVERDOING THE DEGREE OF COOLING ABOVE THE INVERSION AND CONVECTION WILL BE A LITTLE LESS WIDESPREAD THAN MODELS ARE SHOWING...ESPECIALLY SOUTH OF I90. BECAUSE THIS SECOND WAVE IS LATER IN THE NIGHT...HAVE SLOWED THE PROGRESSION OF PRECIPITATION OVERNIGHT INTO WEDNESDAY MORNING WITH THE BEST CHANCE FOR STORMS REMAINING OVER EAST CENTRAL SD THROUGH 12Z AND THEN IN SW MN THROUGH 15Z OR 18Z. ALSO RAISED POPS ALONG AND NORTH I90 LATE TONIGHT TO 30 TO 50 PERCENT RANGE. FINALLY...HAVE INCREASED QPF OVERNIGHT TO AN AVERAGE OF 0.1 TO 0.2 ALONG HWY 14 ALTHOUGH LOCAL AMOUNTS APPROACHING 0.5 IN ARE POSSIBLE WITH STORMS...AROUND BKX AND MML. MADE FEW CHANGES TO TEMPERATURES OR WIND BUT DID INCREASE SKY COVER THIS EVENING. LATEST GRID/ZFP AND PFM ALREADY ISSUED. && .AVIATION.../FOR THE 05Z TAF ISSUANCE/ MAINLY VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. MODELS AND AREA WIND PROFILERS CONTINUE TO SHOW 50-60KT LOW LEVEL JET ABOVE 1500FT AGL...LEADING TO CONCERNS OF LOW LEVEL WIND SHEAR. ALTHOUGH WINDS REMAIN SOMEWHAT GUSTY AT THE SURFACE...WITH LOW LEVEL JET OF THIS MAGNITUDE AND DIRECTION SLIGHTLY VEERED FROM DOMINANT SURFACE WIND DIRECTION...WILL CONTINUE MENTION OF LLWS FOR ALL TAF LOCATIONS TONIGHT...DIMINISHING WEST TO EAST AS WEAKENING GRADIENT WITH COLD FRONT SHIFT EAST. ELEVATED THUNDERSTORMS WILL LIFT NORTHEAST ACROSS THE KHON AREA/MIDDLE JAMES RIVER VALLEY EARLY IN THE TAF PERIOD... WITH POTENTIAL FOR ADDITIONAL ELEVATED DEVELOPMENT AFTER 09Z AS MID LEVEL WAVE MOVES INTO THE AREA FROM THE WEST. BEST CHANCE OF RAIN SHOULD REMAIN NORTH OF I-90...AND LIKELIHOOD OF THUNDER ACTUALLY IMPACTING TAF LOCATIONS IS LOW. HOWEVER DID ADD A POTENTIAL FOR SHOWERS NEAR KHON/KFSD TAF LOCATIONS DURING 09Z-15Z TIME FRAME. PRECIPITATION CHANCES INCREASE AGAIN LATE IN THE PERIOD ALONG AND EAST OF I-29 CORRIDOR AS COLD FRONT PUSHES SLOWLY EAST. CAPPING INVERSION AHEAD OF THE COLD FRONT COULD SUPPRESS CONVECTION UNTIL AFTER 22Z-23Z...BUT CONFIDENCE IN DEVELOPMENT AFTER THAT TIME INCREASES AND HAVE ADDED SHRA/TSRA TO KFSD/KSUX THROUGH WEDNESDAY EVENING. && .PREV DISCUSSION.../ISSUED AT 330 PM CDT/ STRONG SOUTHERLY FLOW CONTINUES ACROSS THE AREA AHEAD OF A COLD FRONT THAT HAS PUSHED INTO FAR NORTHWEST CORNER OF SOUTH DAKOTA. WITH GRADIENT CONTINUING TO STRENGTHEN ALOFT...WILL CONTINUE WIND ADVISORY ACROSS THE AREA THROUGH THE EVENING HOURS AS THE FRONT WORKS EAST THIS EVENING...COULD SEE THUNDERSTORMS DEVELOP BUT EXPECT THE FOCUS TO BE FURTHER NORTH CLOSER TO THE MID LEVEL WAVE. AS SUCH...HAVE NOT MADE MANY ADJUSTMENTS TO POPS WITH FOCUS MAINLY NORTH OF I-90. WITH STOUT WINDS CONTINUING AHEAD OF THE FRONT...KEPT FORECAST LOWS QUITE MILD CLOSER TO CONS RAW AND W MODEL. BOUNDARY IS EXPECTED TO ENTER THE FORECAST AREA AFTER 06Z WEDNESDAY AND SLOWLY PUSH EAST. NOT A LOT IN TERMS OF UPPER LEVEL SUPPORT UNTIL WEDNESDAY EVENING AS UPPER WAVE LIFTS INTO THE REGION...AND WEAK CAPPING INVERSION LOOKS TO HOLD FOR THE BETTER PART OF THE DAY. KEPT CHANCE POPS GOING IN THE VICINITY OF THE FRONT THROUGH THE DAY...BUT FOCUS WILL CERTAINLY BE WEDNESDAY NIGHT. HIGHS WILL GENERALLY BE IN THE 70S TO LOWER 80S WITH 850 HPA TEMPS IN THE MID TEENS. CONTINUES TO LOOK LIKE A POTENTIAL HEAVY RAIN EVENT WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING AS FRONT STALLS ACROSS FAR SOUTHEAST CWA WEDNESDAY NIGHT INTO THURSDAY MORNING WHILE WAVE EJECTS NORTHEAST OUT OF NEBRASKA. INITIALLY COULD SEE SOME SEVERE WEATHER DURING THE EVENING ACROSS NORTHWEST IOWA...BUT MAIN CONCERN WOULD BE THE HEAVY RAINS. MODELS DO DIFFER ON PLACEMENT WITH GFS AND EC A LITTLE FURTHER SOUTH THAN NAM/GEM. PREFER THE GFS/EC SOLUTION WITH BEST CHANCE CLOSER TO FRONT WHERE DEEP MOISTURE WILL POOL AND WHERE HIGHEST PWATS NEAR 1.50 INCHES EXPECTED. SO ACTIVITY THAT DEVELOPS IN THE AFTERNOON SHOULD REALLY GET GOING WEDNESDAY EVENING AND PERSIST THROUGH THE NIGHT WITH LOCAL RAINFALL AMOUNTS OVER 3 INCHES LIKELY ESPECIALLY NEAR THE FRONT AND THEN DROPPING OFF DRAMATICALLY ACROSS FAR NORTHWEST CWA. SO HIGHEST POPS WILL BE ACROSS SOUTHEAST CWA WEDNESDAY NIGHT INTO THURSDAY MORNING...AND THEN A LINGERING SMALLER CHANCE THURSDAY AFTERNOON IN EARLY EVENING. WILL HOLD OFF ANY FLOOD WATCH FOR WEDNESDAY NIGHT...DUE TO UNCERTAINTY ON EXACT LOCATION OF HEAVIEST RAIN...BUT WILL MENTION HEAVY RAIN IN GRIDS ACROSS SOUTHEAST CWA AND ALSO MENTIONED IN HWO. ON FRIDAY...BOUNDARY ACROSS SOUTHERN NEBRASKA AND SOUTHERN IOWA WILL BEGIN TO LIFT SLOWLY NORTH FRIDAY NIGHT INTO SATURDAY...REACHING I90 ON SATURDAY. SO AS THIS FRONT LIFTS NORTH WOULD EXPECT AT LEAST SCATTERED THUNDERSTORMS TO DEVELOP ON EDGE OF MID LEVEL CAP AS LOW LEVEL JET INCREASES DURING THE NIGHT AND WAVE LIFTS NORTHEAST OUT OF WESTERN NEBRASKA. COULD SEE ELEVATED SEVERE STORMS LATER IN THE NIGHT AS THIS FRONT LIFTS NORTH. WITH FRONT ALONG I90 ON SATURDAY...BEST CHANCE FOR THUNDERSTORMS WILL CONTINUE NORTH OF I90 THROUGH SATURDAY...WITH POTENTIAL FOR MORE HEAVY RAIN...THIS TIME ACROSS NORTHERN CWA SATURDAY NIGHT. WILL HIGHLY DEPEND ON LOCATION OF MID LEVEL CAP AND FRONT AND HEAVIEST RAIN COULD FALL NORTH OF CWA. SO WILL HAVE HIGHEST POPS ACROSS NORTHERN CWA AND FAR SOUTHERN CWA MAY NOT SEE ANYTHING AFTER CONVECTION LIFTS NORTH SATURDAY MORNING. VERY HIGH CAPES SOUTH OF BOUNDARY IN CAPPED AIR OVER NORTHWEST IOWA...BUT DEFINATELY SOMETHING TO WATCH NORTH OF BOUNDARY LATE SATURDAY AFTERNOON AND EVENING FOR A ROUND OF SEVERE WEATHER. AS WE HEAD INTO SUNDAY...COLD FRONT WILL PUSH EAST ACROSS CWA SUNDAY AFTERNOON AND NIGHT WITH YET ANOTHER ROUND OF THUNDERSTORMS. IF MID LEVEL CAP CAN BREAK AHEAD OF THIS FRONT WHICH GFS AND EC HINTING AT...COULD SEE SOME SEVERE WEATHER IN THE AFTERNOON AND EVENING ACROSS THE EASTERN CWA. MEMORIAL DAY LOOKS TO BE QUIET AND DRY AND WILL CONTINUE THAT TREND INTO TUESDAY. TEMPERATURES WILL BE ON A ROLLER COASTER THURSDAY THROUGH SUNDAY...WITH COOLER TEMPERATURES IN THE UPPER 60S TO MID 70S THURSDAY AND FRIDAY AND THEN AS FRONT LIFTS NORTH...HIGHS ON SATURDAY WILL LIKELY VARY FROM NEAR 70 ACROSS THE FAR NORTH TO NEAR 90 FAR SOUTHEAST. SHOULD BE WARMER ACROSS ALL OF CWA ON SUNDAY AHEAD OF FRONT WITH HIGHS IN THE 80S...AND THEN COOLING BACK INTO 70S MONDAY AND TUESDAY. && .FSD WATCHES/WARNINGS/ADVISORIES... IA...NONE. MN...NONE. NE...NONE. SD...NONE. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
344 AM CDT WED MAY 23 2012 .SHORT TERM...TODAY THROUGH FRIDAY NIGHT 344 AM CDT WED MAY 23 2012 MAIN FORECAST CONCERNS THIS PACKAGE...WINDS TODAY/THU...SHRA/TSRA CHANCES TONIGHT THRU FRI NIGHT...SEVERE STORM POTENTIAL THU AFTERNOON/EVENING...TEMPERATURES. DATA ANALYSIS AT 06Z HAD HIGH PRESSURE OVER MI AND OH VALLEY AND LOW PRESSURE FROM SOUTH OF LK WINNIPEG TO EASTERN CO. TIGHT PRESSURE GRADIENT AHEAD OF THE LOW WAS OVER MN/WESTERN IA WITH SOUTH/ SOUTHEAST WINDS 20KTS G30KTS OVER MUCH OF THIS AREA. STRONG MOISTURE TRANSPORT AND THETA-E CONVERGENCE CENTERED ON 850MB AHEAD OF THE SFC-850MB TROUGH PRODUCING WIDESPREAD SHRA/TSRA FROM NORTHWEST MN TO EASTERN SD...ALL LIFTING STEADILY NORTHEAST. HIGH LEVEL DEBRIS CLOUDS FROM THE CONVECTION SPILLING SOUTHEAST ACROSS MN/IA/WI. THIS PLUS THE INCREASING SOUTH/SOUTHEAST GRADIENT WINDS KEEPING TEMPS ACROSS THE AREA SOME 10-15F WARMER THAN LAST NIGHT AT THIS TIME. 23.00Z MODELS LOOK TO HAVE INITIALIZED WELL...BUT FOR GFS SOME 5F TO 15F TOO HIGH WITH SFC DEWPOINTS OVER THE NORTHERN PLAINS/WESTERN GREAT LAKE REGIONS. SOLUTIONS QUITE SIMILAR THRU FRI THEN DIVERGE WITH NORTHWARD RETURN OF THE FRONTAL BOUNDARY FRI NIGHT. DPROG/DT OF 500MB HGTS AT 23.00Z SHOWED MODEL RUNS OF 21.00Z AND 22.00Z VERIFIED WELL ACROSS NOAM/EASTERN PAC WITH BETTER RUN-TO-RUN CONSISTENCY AGAIN TO ECMWF. THRU TODAY/TONIGHT MODELS CONVERGING ON A TIGHTER COMPROMISE OF THE EARLIER RUNS...BUT FAVOR SLOWER OF EARLIER RUNS WITH THE ENERGY/TROUGHING MOVING ACROSS THE NORTHERN ROCKIES/ PLAINS. BETTER/TIGHTER CONSENSUS SOLUTION AS THIS TROUGH/ENERGY LIFTS ACROSS THE WESTERN GREAT LAKES THU/THU NIGHT. BETTER RUN-TO- RUN CONSISTENCY BY THU NIGHT TO GFS. CONSENSUS CONTINUED TO IMPROVE FRI/FRI NIGHT AS TROUGHING DEEPENS OVER THE WESTERN CONUS AND DOWN STREAM HGTS RISE OVER THE NORTHERN PLAINS/UPPER MIDWEST. BETTER CONSISTENCY BY SAT MORNING BACK TO ECMWF. CHECK OF OBS VS. MODEL DATA AT 06Z SHOWED MODELS GENERALLY GOOD WITH THE SFC MASS FIELDS OVER THE CENTRAL CONUS BUT GFS REMAINED A BIT HIGH WITH ITS SFC DEW POINTS IN THE PLUME AHEAD OF THE LOW/TROUGH. PER WV IMAGERY ALL LOOKED COMPARABLE WITH THE SHORTWAVE DETAILS OVER NOAM/EASTERN PAC. MOST MODELS LOOK TOO LIGHT WITH THE 00-06Z PRECIP FROM NORTHWEST MN TO EASTERN SD. WETTER GFS LOOKED BEST WITH THIS. WITH THE STRONG TREND TOWARD A TIGHTER CONSENSUS SOLUTION TODAY THRU FRI NIGHT AND NO CLEAR MODEL FAVORITE...FAVORED THE MODEL/ENSEMBLE CONSENSUS. SHORT TERM FCST CONFIDENCE AVERAGE TO GOOD THIS CYCLE. IN THE SHORT TERM...FIRST ISSUE IS STRONGER WINDS THIS AND THU AFTERNOONS. WINDS ACROSS THE WEST END OF THE FCST AREA MAY APPROACH WIND ADVISORY CRITERIA FOR A BRIEF TIME THIS AFTERNOON. GRADIENT CONTINUES TO TIGHTEN OVER THE AREA WITH MOST GUIDANCE INDICATING SUSTAINED SPEEDS OF 20-25KTS THIS AFTERNOON. SOUNDINGS SHOWING A SHALLOWER MIXING DEPTH TODAY...TO 900-875MB MUCH OF THE AFTERNOON... WITH AROUND 35KTS AT THE TOP OF THE MIXED LAYER. WILL HOLD OFF ON ANY WIND ADVISORY FOR NOW BUT WILL BRIEF DAY CREW TO KEEP AN EYE ON IT. SAME THING GOES FOR THU AFTERNOON OVER THE SOUTHEAST 1/3 OF THE FCST AREA WITH TIGHTEST GRADIENT AHEAD OF THE TROUGH SHIFTED EAST. SOUNDINGS AGAIN SHOW MIXING TO 900-875MB WITH ABOUT 35KT ON TOP OF THE MIXED LAYER. SLIGHT SLOWING TREND OF MODELS KEEPS MOISTURE AXIS AND STRONGER OF LOWER LEVEL MOISTURE TRANSPORT/THERMODYNAMIC FORCING WEST OF THE FCST AREA TODAY. KEPT ENTIRE FCST AREA DRY TODAY. THIS MOISTURE/ FORCING/LIFT SLOWLY TRANSLATES EAST TONIGHT...BUT PLENTY OF MID LEVEL WARM AIR AND CAPPING/CIN TO INHIBIT CONVECTION UNTIL THE MID LEVELS COOL WITH APPROACH OF THE TROUGH/SHORTWAVE AND DEEP SATURATION OF THE COLUMN OCCURS. CONTINUED A RATHER TIGHT GRADIENT OF SHRA/TSRA CHANCES FROM NORTHWEST TO SOUTHEAST ACROSS THE FCST AREA TONIGHT. MID LEVEL TROUGH/SHORTWAVE MOVES ACROSS THE AREA THU...ALONG WITH THE SFC-850MB TROUGH/MOISTURE AXIS AND MDT/STRONG SFC-850MB FN CONVERGENCE. MODEL SOUNDINGS INDICATE ANY REMAINING CAPPING ACROSS THE AREA ERODES DURING THE AFTERNOON. QUESTION REMAINS HOW MUCH CAPE CAN BUILD AHEAD OF THE SFC FRONT/TROUGH AXIS AS IT MOVES ACROSS THE AREA ON THU. ONGOING CONVECTION JUST WEST/ NORTH OF THE FCST AREA EARLY THU AND DEBRIS CLOUDS MAY LIMIT WARMING ON THU...AND MAY BE WHY SOME MODELS ONLY DEVELOP 500-1000 J/KG OF ML CAPE AHEAD OF THE SFC TROUGH. DEEPER LIFT/DIVERGENCE ALOFT AND LOW PRESSURE LIFTING NORTHEAST ALONG THE TROUGH/FRONT MAY BE ABLE TO COMPENSATE FOR THE WEAKER CAPE SIGNAL. BASED ON TIMING OF THE LOW/FRONT AND STRONGER FORCING/LIFT MOVING ACROSS THE AREA...SWODY2 LOOKS GOOD. WITH THE TIGHTER MODEL CONSENSUS...RAISED SHRA/TSRA CHANCES INTO THE 60-80 PERCENT RANGE FOR MUCH OF THE AREA BY THU AFTERNOON/EVENING WITH THE TROUGH PASSAGE. WITH THE FRONT WELL EAST OF THE AREA BY 06Z FRI AND DRIER AIR/WEAK HIGH PRESSURE BUILDING IN...CONTINUED OR TRENDED LATER THU NIGHT/FRI TOWARD A DRY PERIOD. WITH TROUGHING DEEPENING OVER THE ROCKIES FRI/FRI NIGHT...LEE TROUGHING STRENGTHENS IN THE CENTRAL PLAINS AND BEGINS TO RETURN THE FRONT BACK NORTH AS A WARM FRONT FRI NIGHT. 925-700MB MOISTURE TRANSPORT/THETA-E CONVERGENCE INTO AND OVER THE FRONTAL BOUNDARY INCREASES AS THE LOWER LEVEL FLOW AHEAD OF THE LEE TROUGH STRENGTHENS AND BECOMES MORE SOUTH/SOUTHWESTERLY. PW VALUES IN THE AIRMASS TO BE ADVECTED INTO/OVER THE FRONT IN THE 1 TO 1.5 INCH RANGE. BY THIS TIME...MODELS DO DIFFER ON HOW QUICKLY THE FRONT LIFTS NORTH...AND WHERE SOME OF THE STRONGER MOISTURE TRANSPORT/ THETA-E CONVERGENCE IS EXPECTED TO OCCUR. GIVEN THE TIGHTER MODEL CONSENSUS AND OVERALL SYNOPTIC SET-UP...RAISED SHRA/TSRA CHANCES FOR FRI NIGHT INTO THE 30-60 PERCENT RANGE...HIGHEST OVER THE SOUTHEAST HALF OF THE FCST AREA CLOSER TO THE FRONT. WITH THE FRONT SOUTH OF THE AREA FRI NIGHT...TSRA WILL BE FORCED WELL ABOVE THE BOUNDARY LAYER WITH LIGHTENING...HEAVY RAINS AND POSSIBLE HAIL THE MAIN THREATS. OVERALL FAVORED A BLEND OF THE GUIDANCE TEMPERATURES FOR HIGHS/LOWS TODAY THRU FRI NIGHT. HIGH TEMPS REMAIN TRICKY BOTH TODAY AND THU. POTENTIAL FOR CIRRUS DEBRIS CLOUDS TO HOLD TEMPS DOWN A BIT TODAY. IF SHRA/TSRA DEVELOP/ARRIVE EARLIER RATHER THAN LATER ON THU... HIGHS IN FCST GRIDS FOR THU MAY ALSO BE TOO WARM. .LONG TERM...SATURDAY THROUGH TUESDAY 344 AM CDT WED MAY 23 2012 MODEL CONSENSUS CONTINUES TO TIGHTEN/IMPROVE THROUGH THE HOLIDAY WEEKEND PERIOD...WITH SAT-TUE FCST CONFIDENCE NOW AVERAGE OR A BIT BETTER. PERSISTENT SOUTH FLOW AHEAD OF THE LEE TROUGH/LOW IN THE PLAINS PUSHES THE WARM FRONT NORTH ACROSS THE AREA SAT/SUN. THIS AS THE LEE LOW EVENTUALLY LIFTS INTO THE NORTHERN PLAINS AND THE MID LEVEL TROUGH SLOWLY EJECTS TOWARD THE NORTHERN PLAINS. CONVECTION EXPECTED TO BE ONGOING NORTH OF THE FRONTAL BOUNDARY SAT...SOMEWHERE ACROSS WI/SOUTHERN MN/NORTHERN IA. THIS CONVECTION HAS POTENTIAL TO STALL THE FRONT/S NORTHWARD PROGRESS ON SAT. ANY BREAKS IN CONVECTION SAT/SAT NIGHT SHOULD ALLOW THE FRONT TO LIFT NORTH OF THE FCST AREA BY OR ON SUNDAY. AGAIN BETTER MODEL SIGNAL FOR THIS TO OCCUR...WITH SUNDAY A VERY WARM/SUMMERY DAY WITH SMALL IF ANY RAIN CHANCES WITH A CAPPED...WARM SECTOR AIRMASS OVER THE AREA. MID LEVEL TROUGH LIFTING ACROSS THE NORTHERN PLAINS INTO SOUTH CAN MON/TUE SENDS A COLD FRONT ACROSS THE AREA ON MON. THIS INTO WHAT SHOULD BE A RATHER MOIST/UNSTABLE AIRMASS OVER THE REGION. SOME TIMING/STRENGTH DIFFERENCES BY MON...SHRA/TSRA CHANCES FROM SUN NIGHT THRU MON NIGHT VERY REASONABLE. MODEL/ENSEMBLE CONSENSUS DATA IN THE DAY 4-7 FCST GRIDS DEPICT THIS QUITE WELL WITH ONLY MINOR ADJUSTMENTS MADE TO BLEND WITH NEIGHBORING GRIDS. && .AVIATION...THROUGH WEDNESDAY NIGHT 1115 PM CDT TUE MAY 22 2012 LATEST RAP AND NAM12 BUFKIT SOUNDINGS BACKING OFF ON THE WINDS IN THE LOW LEVELS JUST A BIT. THE WINDS WILL STILL STAY UP OVERNIGHT...BUT THE LLWS RISK LOOKS LOWER THAN PREVIOUSLY INDICATED. WILL REMOVE FROM KRST FOR NOW. 2 KFT WINDS SHOULD STILL BE NEAR 45 KTS FROM ABOUT 190. WINDS GO FROM SOUTH TO SOUTHWEST ALOFT...NOT OVERLY UNI-DIRECTIONAL. STILL...WITH SOME HIGH CLOUDS SPREADING IN FROM THE WEST... THERE SHOULD BE ENOUGH MIXING TO LEAD TO HIGHER GUSTS...STARTING BY EARLY MORNING...CONTINUING INTO THE AFTERNOON. MODELS TRENDS HAVE BEEN SLOWING THE FRONT DOWN...AND ITS NOW PROGGED TO MOVE OVER THE LOCAL AREA ON THU. LOOK FOR INCREASING... THICKENING...AND LOWERING CIGS LATER WED NIGHT AS A RESULT. HOWEVER...THE SHRA/TS THREAT WILL LIKELY HOLD OFF UNTIL AFTER 12Z THU...AND PERHAPS CLOSER TO 21Z FOR KLSE. && .ARX WATCHES/WARNINGS/ADVISORIES... 344 AM CDT WED MAY 23 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...RRS LONG TERM....RRS AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
735 AM EDT WED MAY 23 2012 .SYNOPSIS... ISSUED AT 734 AM EDT WED MAY 23 2012 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG FM THE UPR MS RIVER VALLEY BTWN A TROF OVER THE PAC NW AND ANOTHER IN QUEBEC. AT THE SFC...THERE IS A 996MB LO PRES OVER THE NRN PLAINS ASSOCIATED WITH A SHRTWV/100KT H3 JET MAX LIFTING OUT OF THE WRN TROF. WARM FNT E OF THIS LO RUNS ACRS NRN MN TO NEAR THE CWA/WI BORDER. THERE ARE SOME SCT -SHRA OVER UPR MI N OF THIS WARM FNT EARLY THIS MRNG IN AREA OF SOME ISENTROPIC ASCENT/MSTR BEST SHOWN ON THE 305K SFC /ABOUT H7/...BUT COVERAGE/INTENSITY IS LIMITED BY VERY DRY AIR IN THE WARM SECTOR AS SHOWN ON THE 00Z MPX RAOB AND ALSO THE 00Z GRB RAOB. IN FACT...SFC DEWPTS IN THE WARM SECTOR MIXED OUT TO AROUND 40 OVER IOWA/SRN MN YDAY AFTN WITH HI TEMPS RISING WELL INTO THE 80S. EXCEPT FOR SOME HI CLDS SPILLING E FM SHRA/TS CLOSER TO THE SFC LO...SKIES ARE MOCLR OVER MUCH OF MN/WI S OF THE WARM FNT. && .SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY EVENING) ISSUED AT 734 AM EDT WED MAY 23 2012 MAIN FCST CONCERNS INTO THU ARE MAINLY FIRE WX RELATED FOLLOWING EXPECTED WARM FROPA THIS MRNG. FOCUS FOR LATER THU AND THU NGT TURN TO POPS WITH APRCH OF COLD FNT FM THE W. TODAY...AS SFC LO PRES IN THE NRN PLAINS DRIFTS NEWD TOWARD FAR NW ONTARIO BY 00Z FRI...ATTENDANT WARM FNT WL LIFT NEWD ACRS THE CWA AND INTO ONTARIO THIS AFTN. WITH THIS SHIFT AND DEPARTURE OF DEEPER MSTR ON THE 305K ISENTROPIC SFC TO THE NE...EXPECT LINGERING -SHRA AND THICKER CLDS OVER UPR MI TO LIFT OUT INTO LK SUP EARLY THIS MRNG. ONCE THE WARM SECTOR MOVES INTO THE CWA WITH H85 TEMPS RISING AS HI AS 17-18C...EXPECT HI TEMPS TO TOP OUT 80 TO 85 PER MIXING TO H8 ON FCST SDNGS OVER PORTIONS OF THE W HALF AWAY FM THE MODERATING INFLUENCE OF LK MI. WITH DAYTIME MIXING OUT THE H100-85 WINDS UP TO 30 KTS AND CAUSING SFC DEWPTS TO FALL AS LO AS 37 TO 45 IN THE AFTN PER UPSTREAM OBS YDAY...MIN RH/FIRE WX PARAMETERS WL AT LEAST APRCH CRITICAL LVLS. OPTED TO ISSUE A WILDFIRE POTENTIAL STATEMENT FOR NOW AND LET THE DAYSHIFT COORDINATE WITH THE USERS ON HEADLINES AS NECESSARY. TNGT...AS NEXT SHRTWV ROTATES THRU THE WRN TROF UPSTREAM OF BLDG RDG OVER THE ERN CONUS...ANOTHER SFC LO PRES WL TAKE SHAPE IN THE PLAINS AND MOVE NNEWD ON COLD FNT ATTENDANT TO FIRST SFC LO DRIFTING THRU NW ONTARIO. UNDER THESE CIRCUMSTANCES...THINK THE 00Z NAM AND ESPECIALLY THE GFS ARE TOO PROGRESSIVE PUSHING PCPN INTO THE WRN CWA. SO TENDED TO FOLLOW THE SLOWER 00Z CNDN AND LOCAL WRF-ARW/12Z ECMWF GUIDANCE. EVEN THOUGH SKIES WL REMAIN MOCLR OVER AT LEAST THE E HALF UNDER AXIS OF DRIEST AIR/HIEST H5...STEADY S WIND WL RESTRICT THE DIURNAL TEMP DROP. THE OVERNGT WL BE ESPECIALLY WARM AND RH RECOVER PARTICULARLY POOR OVER THE W IN THE DOWNSLOPE AREAS NEAR LK SUP AND WHERE AT LEAST THICKER HI CLDS WL MOVE OVHD. THU...AS THE PRIME SHRTWV DRIVES NEWD TOWARD THE UPR LKS AND SFC LO SHIFTS NEAR WRN UPR MI...EXPECT INCRSG POPS OVER ESPECIALLY THE W WITH SOME DPVA/H5 FALLS/UPR DVGC IN RRQ OF UPR JET MAX IN NW ONTARIO AND RETURN OF LLVL MSTR IN THE PRESENCE OF DAYTIME HEATING. MOST OF THE MODELS ARE ACTUALLY IN FAIRLY GOOD AGREEMENT ON THESE DETAILS. ALTHOUGH GUIDANCE SUGS MOST OF THE SHRA/TS WL FALL ON THE COLD SIDE OF THE ACCOMPANYING FNT THAT REACHES THE WRN ZNS WITH THE SFC LO LATE IN THE DAY...SPC HAS INCLUDED MUCH OF THE W HALF OF THE CWA IN A SLGT RISK FOR SVR TS. FCST NAM SDNG FOR IWD LATE IN THE DAY INDICATES SBCAPE REACHING ARND 1000J/KG FOR SFC T/TD 79/60 NEAR FROPA TIME. OVERALL LAPSE RATES DO NOT LOOK TOO IMPRESSIVE WITH FAIRLY NARROW SKINNY CAPE...BUT STRONG WIND FIELDS UP TO 60KT/50KT AT H7/H85 AND PRESENCE OF INVERTED V T/TD PROFILE BLO H8 SUG THE POTENTIAL FOR SOME DAMAGING WINDS IF ENUF LLVL MSTR CAN SURGE AHEAD OF THE FNT TO SUPPORT TS COINCIDENT WITH THE FROPA AND NOT JUST ON THE COLD SIDE OF THE BNDRY. FARTHER TO THE E...THE DAY SHOULD BE BREEZY AND WARM...BUT A RETURN OF HIER H85 DEWPTS/MIXING OF THIS MOISTER AIR TO THE SFC SHOULD LIMIT HOW BAD THE FIRE WX PARAMETERS GO. THU NGT...AS SHRTWV/SFC LO DRIVE NEWD THRU ONTARIO...ATTENDANT COLD FNT WL SWEEP ACRS THE CWA...PASSING ERY LATE. SINCE THE SHARPER DVPA/DEEP LYR QVECTOR CNVGC TEND TO LIFT NEWD INTO ONTARIO WITH THE SHRTWV...SUSPECT THE MODELS AND ESPECIALLY THE NAM MIGHT BE ON THE RIGHT TRACK SHOWING A DCRSG TREND FOR FNTL SHRA/TS...ESPECIALLY LATE WITH LOSS OF ANY DIURNAL HEATING. A GUSTY W WIND IN THE WAKE OF THE FROPA WITH WNW H925 WINDS UP TO 40 KTS WL DRIVE COOLER AIR/H85 TEMPS DOWN TO 8C INTO THE CWA OVERNGT. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 528 AM EDT WED MAY 23 2012 WENT WARMER /ABOUT 5F/ AND WINDIER FOR FRIDAY. WHILE MUCH OF THE WARMER AIR AND PRECIP WILL EXIT EAST WITH THE COLD FRONT EXITING EAST IN THE MORNING...THE SFC TROUGH WILL LINGER OVERHEAD WITH WSW WINDS AT THE SFC. EXPECT 850MB TEMPS TO FALL FROM THE MID TEENS C TO AROUND 10C AROUND DAYBREAK FRIDAY...AND REMAIN STEADY AROUND THIS LEVEL THROUGH SATURDAY. COULD NOT GET RID OF PRECIPITATION ALL TOGETHER FOR...GIVEN 120KT 250MB JET STREAMING ACROSS UPPER MICHIGAN...AND A KICKER OF A SHORTWAVE ALOFT. THERE IS SIGNIFICANT TIMING/STRENGTH DIFFERENCES WITH THIS FEATURE. AS A RESULT...THE CHANCE OF PRECIP/TS WAS LIMITED TO SLIGHT CHANCE. THE 23/00Z GFS DOES SHOW AROUND A QUARTER OF AN INCH OF LIQUID CENTRAL DURING THE AFTERNOON HOURS...WHILE THE OTHER MODELS ARE MUCH DRIER. ALTHOUGH HIGH PRESSURE FROM CENTRAL CANADA WILL ATTEMPT TO SINK ACROSS THE UPPER GREAT LAKES FOR SATURDAY...IT WILL BE PUSHED EASTWARD...SKIMMING NORTHERN AND EASTERN UPPER MI SATURDAY INTO SATURDAY NIGHT. MUCH OF THIS WILL BE DUE TO THE NEXT LOW DEVELOPING OVER THE CENTRAL STATES. THE LOW WILL MOVE TO THE DAKOTAS/NE BY SUNDAY AFTERNOON...WITH A WARM FRONT QUICKLY PUSHING UP ACROSS THE CWA AND 850MB TEMPS JUMPING TO AROUND 18C SUNDAY NIGHT INTO MONDAY MORNING. THE 23/00Z GFS IS MORE PROGRESSIVE WITH THE SFC LOW...AVERAGING OUT TO BE ABOUT 6 HOURS QUICKER THAN THE 23/00Z ECMWF FROM SATURDAY NIGHT THROUGH EARLY MONDAY AFTERNOON. THE SLOW MOVING SYSTEM WILL CONTINUE TO INFLUENCE OUR WEATHER THROUGH THE START OF THE NEXT WORK WEEK...WITH A CHANCE OF SHOWERS LINGERING THROUGH MONDAY. TEMPERATURES WILL EVENTUALLY COOL TUESDAY...BACK TO BELOW NORMAL READINGS /MAINLY IN THE 50S TO MID 60S/. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 539 AM EDT WED MAY 23 2012 STRONG WINDS WILL BE THE MAIN CONCERN OVER THE NEXT 24 HOURS...OUT OF A SOUTHERLY DIRECTION...AHEAD OF LOW PRESSURE STRETCHING FROM S CENTRAL CANADA THROUGH THE CENTRAL PLAINS STATES. LLWS AT NIGHT WILL BE LIKELY AT ALL 3 SITS...EVEN WITH IWD LIKELY KEEPING GUSTS AT OR ABOVE 20KTS THROUGH THE OVERNIGHT HOURS. OTHERWISE...VFR CEILINGS AND VIS SHOULD REMAIN...WITH ONLY A SMALL CHANCE OF SHOWERS AND/OR THUNDERSTORMS GETTING TO IWD BY 12Z THURSDAY. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 528 AM EDT WED MAY 23 2012 LOW PRESSURE OVER S MANITOBA WILL PUSH INTO ONTARIO TONIGHT AND THURSDAY...AS AN ADDITIONAL LOW MOVES FROM THE CENTRAL PLAINS TO W LS FRIDAY AFTERNOON. EXPECT THE LOW TO CONTINUE A NE TRACK ACROSS ONTARIO THROUGH FRIDAY...WITH A TROUGH LINGERING ACROSS LAKE SUPERIOR. STRENGTHENING S WINDS WILL BE THE RULE AHEAD OF THIS SYSTEM TODAY THROUGH TOMORROW...STRONGEST ACROSS THE TALLER OBSERVING PLATFORMS ACROSS CENTRAL LS. HIGH PRESSURE OVER CENTRAL CANADA FRIDAY NIGHT WILL SLIDE ACROSS ONTARIO SATURDAY...BEFORE SETTLING ACROSS HUDSON BAY ON SUNDAY. AS A RESULT...A RIDGE WILL SLIDE ACROSS LS SATURDAY...WITH LIGHTER WINDS TAKING HOLD. A LOW ACROSS THE CENTRAL PLAINS WILL FILL ACROSS MN SUNDAY INTO SUNDAY NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...KC SHORT TERM...KC LONG TERM...KF AVIATION...KF MARINE...KF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1031 AM EDT WED MAY 23 2012 .SYNOPSIS... OUTSIDE A STRAY AFTERNOON OR EARLY EVENING SHOWER OR STORM...MAINLY DRY WEATHER IS EXPECTED THROUGH THURSDAY WITH WARM TEMPERATURES AND MODEST HUMIDITY LEVELS. A WEAKENING COLD FRONT WILL PUSH THROUGH THE AREA FRIDAY NIGHT INTO SATURDAY THOUGH AGAIN SHOWERY PRECIPITATION WILL BE SCATTERED AT BEST. WARM TEMPERATURES CONTINUE INTO NEXT WEEK WITH MORE ACTIVE WEATHER POSSIBLE AS SHOWERS AND THUNDERSTORMS WILL BE MORE COMMON. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1013 AM EDT WEDNESDAY...SEVERAL MINOR UPDATES TO CRNT FCST...BASED ON VIS SATL PICS AND CRNT OBS. VIS SATL PIC SHOWS SOME BREAKS ACRS THE HIGHER ELEVATIONS OF THE DACKS AND SOME CLRING ACRS THE SLV. SOUNDINGS SHOW SOLID RH PROFILES THRU 18Z...THEN SOME CLRING. WL USE VIS SALT TOOL IN GFE TO CAPTURE CRNT TRENDS...THEN TAPER OVERALL AREAL COVERAGE OF CLOUDS AFT 18Z THIS AFTN...BASED ON SOUNDING RH PROFILES. OTHERWISE...HAVE DECREASED HRLY TEMPS THIS MORNING DUE TO CLOUDS...BUT FEEL AS BREAKS DEVELOP THIS AFTN...TEMPS WL CLIMB QUICKLY. REST OF FCST IN GREAT SHAPE. MODEST ADJUSTMENTS TO SKY COVER TO KEEP MOSTLY CLOUDY CONDS ACROSS MUCH OF THE AREA THROUGH THE MORNING HOURS BASED OFF CURRENT OBSERVATIONAL/SATELLITE TRENDS AND LATEST RAP 925MB RH PROGS. ALSO NUDGED MAX TEMPS DOWN JUST A TAD (1-2 DEG). REST OF FCST UNCHANGED. PRIOR DISCUSSION... WEAK AND DISSOLVING FRONTAL SYSTEM CONTINUES TO SAG EVER SO SLOWLY SOUTHWARD THROUGH THE FORECAST AREA THIS MORNING AS WINDS HAVE SHIFTED TO LIGHT NORTH/NORTHEASTERLY ACROSS OUR NRN COUNTIES AS OF 3 AM. STILL A FEW SHOWERS/PATCHY -DZ AROUND THE AREA WITH NEAR SATURATED LOWER LEVELS. OTHERWISE A RATHER UNEVENTFUL DAY ON TAP WEATHERWISE FOR THE REGION AS AFOREMENTIONED FRONTAL SYSTEM DISSIPATES TO OUR IMMEDIATE SOUTH ACROSS CENTRAL/SRN NEW ENGLAND. DESPITE LIGHT NORTHERLY FLOW...NO APPRECIABLE AIRMASS CHANGE EXPECTED AND MUCH DRIER AIR OFF TO OUR NORTH ACROSS SRN ON/QE REALLY WON`T MAKE APPRECIABLE INROADS INTO OUR AREA. VARIABLY CLOUDY SKIES AND PATCHY BR/FG THIS MORNING SHOULD SCOUR OUT TO PTLY SUNNY IN MANY AREAS THIS AFTERNOON AS PBL DEEPENS. STILL COULD SEE AN ISOLD LATE AFTERNOON/EARLY EVENING SHOWER/STORM FAR SOUTH IN CLOSER PROXIMITY TO OLD BOUNDARY AND DEEPER MOISTURE AXIS...BUT DRY WEATHER WILL BE THE GENERAL RULE. BLENDED 18-00Z MODEL 925 MB THERMAL PROGS SUPPORT BLENDED MOS LATE AFTERNOON HIGHS IN THE 72 TO 78 DEGREE RANGE. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... AS OF 344 AM EDT WEDNESDAY...THEN QUIET TONIGHT AS DEEP LAYER SFC TO H5 RIDGING BEGINS TO BUILD BACK ACROSS THE REGION. MAINLY CLR/PTLY CLOUDY SKIES EXPECTED...THOUGH AS FLOW TRENDS LIGHT SOUTH/SOUTHEASTERLY OVERNIGHT A DECENT CHANCE THAT SOME LOWER CLOUD COVER MAY BEGIN TO ENCROACH BACK NORTHWARD INTO OUR SRN/SERN VT COUNTIES AFTER MIDNIGHT. PATCHY FOG ALSO A GOOD BET AS WET GROUND CONDS FOSTER SATURATION IN THE NEAR-SFC LAYERS. LOWS SIMILAR TO THIS MORNING...MAINLY 50S TO LOCALLY NEAR 60 IN MILDER SPOTS OF THE CHAMPLAIN VALLEY. BY THURSDAY RIDGING WILL BECOME WELL ESTABLISHED ACROSS THE AREA AS SOUTHERLY FLOW SLOWLY INCREASES AND TRENDS MODESTLY GUSTY BY AFTERNOON. STILL AN OUTSIDE CHANCE OF A FEW SHOWERS/STRAY STORMS HERE AND THERE DURING PEAK HEATING HOURS SOUTH AS SFC INSOLATION ACTS ON RESIDUAL MOISTURE AXIS...OTHERWISE DRY AND PTLY SUNNY SHOULD BE THE RULE IN MOST LOCALES. TEMPERATURES A TAD WARMER INTO THE 77 TO 83 RANGE...CONTINUING RECENT STRING OF ABOVE NORMAL DAYS. THEN PTLY/MOSTLY CLOUDY AND MILD THURSDAY NIGHT AS TEMPERATURES HOLD IN THE UPPER 50S TO LOWER 60S. BY FRIDAY...GUSTY SOUTHERLY FLOW CONTINUES ACROSS THE AREA ALONG WITH A CONTINUED ISOLD THREAT OF A FEW SHOWERS/STORMS HERE AND THERE BY THE AFTERNOON/EARLY EVENING HOURS. BEST THREAT APPEARS TO OCCUR ACROSS THE SLV WHERE ADDED MOISTURE CONVERGENCE AND APPROACHING WEAK FRONTAL SYSTEM MAY AID IN SOMEWHAT HIGHER COVERAGE TOWARD EVENING. CONTINUED UNSEASONABLY WARM WITH HIGHS 78 TO 85 AND MODEST HUMIDITY LEVELS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 445 AM EDT WEDNESDAY...THE PERIOD WILL START WITH A COLD FRONT TRAVERSING OVER THE FCST AREA. 00Z GFS AND ECMWF DIFFER ON TIMING OF FRONTAL PASSAGE...BUT BOTH MODELS SHOW FRONT LINGERING ALONG THE ATLANTIC COAST BY SATURDAY NIGHT. HIGH PRESSURE WILL THEN BUILD IN AT THE SFC FROM SOUTHERN QUEBEC...GIVING A SHORT DRY PERIOD ON SATURDAY INTO EARLY SUNDAY. LATE SUNDAY...MODEL GUIDANCE INDICATES AN UPPER LEVEL DISTURBANCE/WEAK SHORT WAVE WILL MOVE OVER THE REGION...WITH AN UPPER LEVEL JET TO OUR NORTH. INCREASED INSTABILITY LATE SUNDAY INTO MONDAY WITH GFS INDICATING CAPE VALUES OVER 1000J/KG AND NEGATIVE LIFTED INDICES. ECMWF KEEPS THE HIGH CAPE VALUE TO OUR SOUTH. THE AFOREMENTIONED COLD FRONT WILL LIFT NORTHWARD AS A WARM FRONT AS LOW PRESSURE CENTER AT THE SFC MOVES FROM THE NWRN GREAT LAKES TO SE ONTARIO MONDAY AND TUESDAY. THIS WILL CONTINUE TO PRODUCE CHANCE OF SHOWERS. TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL...WITH A SLGT COOLING TREND TO START. 850HPA TEMPS WILL COOL FROM THE MID TEENS TO 10C-12C SUNDAY. ECWMF HAS FRONT SYSTEM BEING STRONGER THAN GFS AND BRINGS SINGLE DIGIT TEMPS AT 850HPA BY MONDAY MORNING. BOTH MODELS DO SHOW DECENT TEMP GRADIENT OVER THE NORTHEAST WHICH WILL HELP WITH POTENTIAL FOR CONVECTIVE ACTIVITY. BOTH MODELS WARM TEMPS ON MONDAY TO MID TO UPPER TEENS AT 850HPA...BUT GRADUALLY COOLING ON TUESDAY. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... THROUGH 12Z THURSDAY...CLOUDS WILL GRADUALLY DISSIPATE THIS MORNING...WITH IMPROVING VSBYS. OVERALL FLIGHT CONDITIONS WILL IMPROVE TO MVFR BY LATE MORNING...15Z AT KBTV/KPBG/RUT/ CONDITIONS WILL CONTINUE TO IMPROVE TO VFR BY LATE MORNING/EARLY AFTERNOON AT ALL TERMINALS. CLOUDS WILL GENERALLY BECOME SCT TO BKN MID AND HIGH LEVEL FOR THE AFTERNOON AND EVENING. OVERNIGHT...MOISTURE WILL SURGE NORTHWARD INTO THE AREA...ALLOWING FOR MVFR CONDITIONS TO DEVELOP AROUND 05Z-06Z THROUGH THURSDAY MORNING. OUTLOOK 12Z THURSDAY THROUGH SUNDAY... 12Z THURSDAY THROUGH 18Z FRIDAY...GENERALLY VFR UNDER RIDGE OF HIGH PRESSURE...ALTHOUGH SOME FOG/BR POSSIBLE THURSDAY MORNING. 18Z FRIDAY THROUGH SUNDAY...GENERALLY VFR BUT BRIEF PERIODS OF MVFR POSSIBLE IN SCATTERED SHOWERS/TSTORMS. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...JMG NEAR TERM...JMG/TABER SHORT TERM...JMG LONG TERM...KGM AVIATION...KGM
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
751 AM EDT WED MAY 23 2012 .SYNOPSIS... OUTSIDE A STRAY AFTERNOON OR EARLY EVENING SHOWER OR STORM...MAINLY DRY WEATHER IS EXPECTED THROUGH THURSDAY WITH WARM TEMPERATURES AND MODEST HUMIDITY LEVELS. A WEAKENING COLD FRONT WILL PUSH THROUGH THE AREA FRIDAY NIGHT INTO SATURDAY THOUGH AGAIN SHOWERY PRECIPITATION WILL BE SCATTERED AT BEST. WARM TEMPERATURES CONTINUE INTO NEXT WEEK WITH MORE ACTIVE WEATHER POSSIBLE AS SHOWERS AND THUNDERSTORMS WILL BE MORE COMMON. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 722 AM EDT WEDNESDAY...MODEST ADJUSTMENTS TO SKY COVER TO KEEP MOSTLY CLOUDY CONDS ACROSS MUCH OF THE AREA THROUGH THE MORNING HOURS BASED OFF CURRENT OBSERVATIONAL/SATELLITE TRENDS AND LATEST RAP 925MB RH PROGS. ALSO NUDGED MAX TEMPS DOWN JUST A TAD (1-2 DEG). REST OF FCST UNCHANGED. PRIOR DISCUSSION... WEAK AND DISSOLVING FRONTAL SYSTEM CONTINUES TO SAG EVER SO SLOWLY SOUTHWARD THROUGH THE FORECAST AREA THIS MORNING AS WINDS HAVE SHIFTED TO LIGHT NORTH/NORTHEASTERLY ACROSS OUR NRN COUNTIES AS OF 3 AM. STILL A FEW SHOWERS/PATCHY -DZ AROUND THE AREA WITH NEAR SATURATED LOWER LEVELS. OTHERWISE A RATHER UNEVENTFUL DAY ON TAP WEATHERWISE FOR THE REGION AS AFOREMENTIONED FRONTAL SYSTEM DISSIPATES TO OUR IMMEDIATE SOUTH ACROSS CENTRAL/SRN NEW ENGLAND. DESPITE LIGHT NORTHERLY FLOW...NO APPRECIABLE AIRMASS CHANGE EXPECTED AND MUCH DRIER AIR OFF TO OUR NORTH ACROSS SRN ON/QE REALLY WON`T MAKE APPRECIABLE INROADS INTO OUR AREA. VARIABLY CLOUDY SKIES AND PATCHY BR/FG THIS MORNING SHOULD SCOUR OUT TO PTLY SUNNY IN MANY AREAS THIS AFTERNOON AS PBL DEEPENS. STILL COULD SEE AN ISOLD LATE AFTERNOON/EARLY EVENING SHOWER/STORM FAR SOUTH IN CLOSER PROXIMITY TO OLD BOUNDARY AND DEEPER MOISTURE AXIS...BUT DRY WEATHER WILL BE THE GENERAL RULE. BLENDED 18-00Z MODEL 925 MB THERMAL PROGS SUPPORT BLENDED MOS LATE AFTERNOON HIGHS IN THE 72 TO 78 DEGREE RANGE. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... AS OF 344 AM EDT WEDNESDAY...THEN QUIET TONIGHT AS DEEP LAYER SFC TO H5 RIDGING BEGINS TO BUILD BACK ACROSS THE REGION. MAINLY CLR/PTLY CLOUDY SKIES EXPECTED...THOUGH AS FLOW TRENDS LIGHT SOUTH/SOUTHEASTERLY OVERNIGHT A DECENT CHANCE THAT SOME LOWER CLOUD COVER MAY BEGIN TO ENCROACH BACK NORTHWARD INTO OUR SRN/SERN VT COUNTIES AFTER MIDNIGHT. PATCHY FOG ALSO A GOOD BET AS WET GROUND CONDS FOSTER SATURATION IN THE NEAR-SFC LAYERS. LOWS SIMILAR TO THIS MORNING...MAINLY 50S TO LOCALLY NEAR 60 IN MILDER SPOTS OF THE CHAMPLAIN VALLEY. BY THURSDAY RIDGING WILL BECOME WELL ESTABLISHED ACROSS THE AREA AS SOUTHERLY FLOW SLOWLY INCREASES AND TRENDS MODESTLY GUSTY BY AFTERNOON. STILL AN OUTSIDE CHANCE OF A FEW SHOWERS/STRAY STORMS HERE AND THERE DURING PEAK HEATING HOURS SOUTH AS SFC INSOLATION ACTS ON RESIDUAL MOISTURE AXIS...OTHERWISE DRY AND PTLY SUNNY SHOULD BE THE RULE IN MOST LOCALES. TEMPERATURES A TAD WARMER INTO THE 77 TO 83 RANGE...CONTINUING RECENT STRING OF ABOVE NORMAL DAYS. THEN PTLY/MOSTLY CLOUDY AND MILD THURSDAY NIGHT AS TEMPERATURES HOLD IN THE UPPER 50S TO LOWER 60S. BY FRIDAY...GUSTY SOUTHERLY FLOW CONTINUES ACROSS THE AREA ALONG WITH A CONTINUED ISOLD THREAT OF A FEW SHOWERS/STORMS HERE AND THERE BY THE AFTERNOON/EARLY EVENING HOURS. BEST THREAT APPEARS TO OCCUR ACROSS THE SLV WHERE ADDED MOISTURE CONVERGENCE AND APPROACHING WEAK FRONTAL SYSTEM MAY AID IN SOMEWHAT HIGHER COVERAGE TOWARD EVENING. CONTINUED UNSEASONABLY WARM WITH HIGHS 78 TO 85 AND MODEST HUMIDITY LEVELS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 445 AM EDT WEDNESDAY...THE PERIOD WILL START WITH A COLD FRONT TRAVERSING OVER THE FCST AREA. 00Z GFS AND ECMWF DIFFER ON TIMING OF FRONTAL PASSAGE...BUT BOTH MODELS SHOW FRONT LINGERING ALONG THE ATLANTIC COAST BY SATURDAY NIGHT. HIGH PRESSURE WILL THEN BUILD IN AT THE SFC FROM SOUTHERN QUEBEC...GIVING A SHORT DRY PERIOD ON SATURDAY INTO EARLY SUNDAY. LATE SUNDAY...MODEL GUIDANCE INDICATES AN UPPER LEVEL DISTURBANCE/WEAK SHORT WAVE WILL MOVE OVER THE REGION...WITH AN UPPER LEVEL JET TO OUR NORTH. INCREASED INSTABILITY LATE SUNDAY INTO MONDAY WITH GFS INDICATING CAPE VALUES OVER 1000J/KG AND NEGATIVE LIFTED INDICES. ECMWF KEEPS THE HIGH CAPE VALUE TO OUR SOUTH. THE AFOREMENTIONED COLD FRONT WILL LIFT NORTHWARD AS A WARM FRONT AS LOW PRESSURE CENTER AT THE SFC MOVES FROM THE NWRN GREAT LAKES TO SE ONTARIO MONDAY AND TUESDAY. THIS WILL CONTINUE TO PRODUCE CHANCE OF SHOWERS. TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL...WITH A SLGT COOLING TREND TO START. 850HPA TEMPS WILL COOL FROM THE MID TEENS TO 10C-12C SUNDAY. ECWMF HAS FRONT SYSTEM BEING STRONGER THAN GFS AND BRINGS SINGLE DIGIT TEMPS AT 850HPA BY MONDAY MORNING. BOTH MODELS DO SHOW DECENT TEMP GRADIENT OVER THE NORTHEAST WHICH WILL HELP WITH POTENTIAL FOR CONVECTIVE ACTIVITY. BOTH MODELS WARM TEMPS ON MONDAY TO MID TO UPPER TEENS AT 850HPA...BUT GRADUALLY COOLING ON TUESDAY. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... THROUGH 12Z THURSDAY...CLOUDS WILL GRADUALLY DISSIPATE THIS MORNING...WITH IMPROVING VSBYS. OVERALL FLIGHT CONDITIONS WILL IMPROVE TO MVFR BY LATE MORNING...15Z AT KBTV/KPBG/RUT/ CONDITIONS WILL CONTINUE TO IMPROVE TO VFR BY LATE MORNING/EARLY AFTERNOON AT ALL TERMINALS. CLOUDS WILL GENERALLY BECOME SCT TO BKN MID AND HIGH LEVEL FOR THE AFTERNOON AND EVENING. OVERNIGHT...MOISTURE WILL SURGE NORTHWARD INTO THE AREA...ALLOWING FOR MVFR CONDITIONS TO DEVELOP AROUND 05Z-06Z THROUGH THURSDAY MORNING. OUTLOOK 12Z THURSDAY THROUGH SUNDAY... 12Z THURSDAY THROUGH 18Z FRIDAY...GENERALLY VFR UNDER RIDGE OF HIGH PRESSURE...ALTHOUGH SOME FOG/BR POSSIBLE THURSDAY MORNING. 18Z FRIDAY THROUGH SUNDAY...GENERALLY VFR BUT BRIEF PERIODS OF MVFR POSSIBLE IN SCATTERED SHOWERS/TSTORMS. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...JMG NEAR TERM...JMG SHORT TERM...JMG LONG TERM...KGM AVIATION...KGM
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
722 AM EDT WED MAY 23 2012 .SYNOPSIS... OUTSIDE A STRAY AFTERNOON OR EARLY EVENING SHOWER OR STORM...MAINLY DRY WEATHER IS EXPECTED THROUGH THURSDAY WITH WARM TEMPERATURES AND MODEST HUMIDITY LEVELS. A WEAKENING COLD FRONT WILL PUSH THROUGH THE AREA FRIDAY NIGHT INTO SATURDAY THOUGH AGAIN SHOWERY PRECIPITATION WILL BE SCATTERED AT BEST. WARM TEMPERATURES CONTINUE INTO NEXT WEEK WITH MORE ACTIVE WEATHER POSSIBLE AS SHOWERS AND THUNDERSTORMS WILL BE MORE COMMON. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 722 AM EDT WEDNESDAY...MODEST ADJUSTMENTS TO SKY COVER TO KEEP MOSTLY CLOUDY CONDS ACROSS MUCH OF THE AREA THROUGH THE MORNING HOURS BASED OFF CURRENT OBSERVATIONAL/SATELLITE TRENDS AND LATEST RAP 925MB RH PROGS. ALSO NUDGED MAX TEMPS DOWN JUST A TAD (1-2 DEG). REST OF FCST UNCHANGED. PRIOR DISCUSSION... WEAK AND DISSOLVING FRONTAL SYSTEM CONTINUES TO SAG EVER SO SLOWLY SOUTHWARD THROUGH THE FORECAST AREA THIS MORNING AS WINDS HAVE SHIFTED TO LIGHT NORTH/NORTHEASTERLY ACROSS OUR NRN COUNTIES AS OF 3 AM. STILL A FEW SHOWERS/PATCHY -DZ AROUND THE AREA WITH NEAR SATURATED LOWER LEVELS. OTHERWISE A RATHER UNEVENTFUL DAY ON TAP WEATHERWISE FOR THE REGION AS AFOREMENTIONED FRONTAL SYSTEM DISSIPATES TO OUR IMMEDIATE SOUTH ACROSS CENTRAL/SRN NEW ENGLAND. DESPITE LIGHT NORTHERLY FLOW...NO APPRECIABLE AIRMASS CHANGE EXPECTED AND MUCH DRIER AIR OFF TO OUR NORTH ACROSS SRN ON/QE REALLY WON`T MAKE APPRECIABLE INROADS INTO OUR AREA. VARIABLY CLOUDY SKIES AND PATCHY BR/FG THIS MORNING SHOULD SCOUR OUT TO PTLY SUNNY IN MANY AREAS THIS AFTERNOON AS PBL DEEPENS. STILL COULD SEE AN ISOLD LATE AFTERNOON/EARLY EVENING SHOWER/STORM FAR SOUTH IN CLOSER PROXIMITY TO OLD BOUNDARY AND DEEPER MOISTURE AXIS...BUT DRY WEATHER WILL BE THE GENERAL RULE. BLENDED 18-00Z MODEL 925 MB THERMAL PROGS SUPPORT BLENDED MOS LATE AFTERNOON HIGHS IN THE 72 TO 78 DEGREE RANGE. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... AS OF 344 AM EDT WEDNESDAY...THEN QUIET TONIGHT AS DEEP LAYER SFC TO H5 RIDGING BEGINS TO BUILD BACK ACROSS THE REGION. MAINLY CLR/PTLY CLOUDY SKIES EXPECTED...THOUGH AS FLOW TRENDS LIGHT SOUTH/SOUTHEASTERLY OVERNIGHT A DECENT CHANCE THAT SOME LOWER CLOUD COVER MAY BEGIN TO ENCROACH BACK NORTHWARD INTO OUR SRN/SERN VT COUNTIES AFTER MIDNIGHT. PATCHY FOG ALSO A GOOD BET AS WET GROUND CONDS FOSTER SATURATION IN THE NEAR-SFC LAYERS. LOWS SIMILAR TO THIS MORNING...MAINLY 50S TO LOCALLY NEAR 60 IN MILDER SPOTS OF THE CHAMPLAIN VALLEY. BY THURSDAY RIDGING WILL BECOME WELL ESTABLISHED ACROSS THE AREA AS SOUTHERLY FLOW SLOWLY INCREASES AND TRENDS MODESTLY GUSTY BY AFTERNOON. STILL AN OUTSIDE CHANCE OF A FEW SHOWERS/STRAY STORMS HERE AND THERE DURING PEAK HEATING HOURS SOUTH AS SFC INSOLATION ACTS ON RESIDUAL MOISTURE AXIS...OTHERWISE DRY AND PTLY SUNNY SHOULD BE THE RULE IN MOST LOCALES. TEMPERATURES A TAD WARMER INTO THE 77 TO 83 RANGE...CONTINUING RECENT STRING OF ABOVE NORMAL DAYS. THEN PTLY/MOSTLY CLOUDY AND MILD THURSDAY NIGHT AS TEMPERATURES HOLD IN THE UPPER 50S TO LOWER 60S. BY FRIDAY...GUSTY SOUTHERLY FLOW CONTINUES ACROSS THE AREA ALONG WITH A CONTINUED ISOLD THREAT OF A FEW SHOWERS/STORMS HERE AND THERE BY THE AFTERNOON/EARLY EVENING HOURS. BEST THREAT APPEARS TO OCCUR ACROSS THE SLV WHERE ADDED MOISTURE CONVERGENCE AND APPROACHING WEAK FRONTAL SYSTEM MAY AID IN SOMEWHAT HIGHER COVERAGE TOWARD EVENING. CONTINUED UNSEASONABLY WARM WITH HIGHS 78 TO 85 AND MODEST HUMIDITY LEVELS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 445 AM EDT WEDNESDAY...THE PERIOD WILL START WITH A COLD FRONT TRAVERSING OVER THE FCST AREA. 00Z GFS AND ECMWF DIFFER ON TIMING OF FRONTAL PASSAGE...BUT BOTH MODELS SHOW FRONT LINGERING ALONG THE ATLANTIC COAST BY SATURDAY NIGHT. HIGH PRESSURE WILL THEN BUILD IN AT THE SFC FROM SOUTHERN QUEBEC...GIVING A SHORT DRY PERIOD ON SATURDAY INTO EARLY SUNDAY. LATE SUNDAY...MODEL GUIDANCE INDICATES AN UPPER LEVEL DISTURBANCE/WEAK SHORT WAVE WILL MOVE OVER THE REGION...WITH AN UPPER LEVEL JET TO OUR NORTH. INCREASED INSTABILITY LATE SUNDAY INTO MONDAY WITH GFS INDICATING CAPE VALUES OVER 1000J/KG AND NEGATIVE LIFTED INDICES. ECMWF KEEPS THE HIGH CAPE VALUE TO OUR SOUTH. THE AFOREMENTIONED COLD FRONT WILL LIFT NORTHWARD AS A WARM FRONT AS LOW PRESSURE CENTER AT THE SFC MOVES FROM THE NWRN GREAT LAKES TO SE ONTARIO MONDAY AND TUESDAY. THIS WILL CONTINUE TO PRODUCE CHANCE OF SHOWERS. TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL...WITH A SLGT COOLING TREND TO START. 850HPA TEMPS WILL COOL FROM THE MID TEENS TO 10C-12C SUNDAY. ECWMF HAS FRONT SYSTEM BEING STRONGER THAN GFS AND BRINGS SINGLE DIGIT TEMPS AT 850HPA BY MONDAY MORNING. BOTH MODELS DO SHOW DECENT TEMP GRADIENT OVER THE NORTHEAST WHICH WILL HELP WITH POTENTIAL FOR CONVECTIVE ACTIVITY. BOTH MODELS WARM TEMPS ON MONDAY TO MID TO UPPER TEENS AT 850HPA...BUT GRADUALLY COOLING ON TUESDAY. && .AVIATION /11Z WEDNESDAY THROUGH SUNDAY/... THROUGH 06Z THURSDAY...WIDELY VARYING CONDITIONS ACROSS THE NORTHEAST AS FRONTAL PASSAGE HAS SHIFTED WINDS TO THE NE AT KMSS AND NW AT KBTV AND KPBG. IFR/LIFR CONDITIONS AT KBTV AND KPBG EXPECTED OVERNIGHT AS KBTV IS EXPERIENCING -RA/-DZ WITH NW FLOW CONVERGING LIFR CIGS OVER THE TAF SITE. PERSISTENT NW FLOW WILL CONTINUE POOR CONDITIONS OVER BTV AT LIFR TO IFR THROUGH THE REST OF THE OVERNIGHT INTO WEDNESDAY MORNING. KPBG SLIGHTLY BETTER CONDITIONS WITH IFR/MVFR EXPECTED OVERNIGHT. CONDITIONS AT BOTH KBTV AND KPBG WILL IMPROVE IN THE LATE MORNING TO VFR AND CONTINUE TO IMPROVE AS THE BACK EDGE OF THE CLOUD SHIELD APPROACHES IN THE LATE MORNING/EARLY AFTERNOON WITH SLIGHTLY DRIER AIR FILTERING IN AS WELL. VFR/MVFR CONDITIONS AT REST OF THE TAF SITES WILL PERSIST OVERNIGHT...DETERIORATING TO IFR AT KSLK. HAVE ALSO INCLUDED TEMPOS FOR IFR CIGS AT KMPV AND KMSS. WITH LACK OF WINDS AND ONLY LIGHT FLOW ALOFT...CLOUDS WILL BE SLOW TO LIFT WEDNESDAY MORNING. BUT OVERALL IMPROVEMENT TO VFR EXPECTED AT ALL TAF SITES BY LATE MORNING. CONTINUED DIMINISHING CLOUD COVER WILL CONTINUE IN THE AFTERNOON. MAY SEE AN ISOLATED SHOWER AT RUT/MPV ON WEDNESDAY BUT LEFT OUT FOR NOW. AS EVENING APPROACHES...CLOUDS WILL INCREASE FROM THE SOUTH AS MOISTURE ADVECTS NORTHWARD. OUTLOOK 06Z THURSDAY THROUGH SUNDAY... 06Z THURSDAY THROUGH 18Z FRIDAY...GENERALLY VFR UNDER RIDGE OF HIGH PRESSURE...ALTHOUGH SOME FOG/BR POSSIBLE THURSDAY MORNING. 18Z FRIDAY THROUGH SUNDAY...GENERALLY VFR BUT BRIEF PERIODS OF MVFR POSSIBLE IN SCATTERED SHOWERS/TSTORMS. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...JMG NEAR TERM...JMG SHORT TERM...JMG LONG TERM...KGM AVIATION...KGM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1040 AM EDT WED MAY 23 2012 .SYNOPSIS... UPPER AIR SYSTEM SLOWLY DRIFTS BY JUST TO OUR SOUTH...PROVIDING SLOW MOVING CONVECTION AGAIN TODAY. WARMER AND DRIER AIR FOR THE END OF WEEK. && .NEAR TERM /THROUGH TONIGHT/... 1030 AM UPDATE...TWEAKED POPS SOME FOR TODAY...LEANING TOWARDS THE HRRR AND RAP WHICH FIRE CONVECTION OVER THE MOUNTAINS EARLY THIS AFTERNOON...AND THEN DRIFT IT SLOWLY WESTWARD AS THE STORMS RAIN THEMSELVES OUT. ALSO THINK THERE WILL BE MORE ISOLATED POP UPS ACROSS THE LOWLANDS TOWARDS THE OHIO RIVER...BUT EXACT TIMING AND PLACEMENT OF THESE IS STILL MORE UNCERTAIN. NAM SHOWS SOME 1000J/KG+ CAPE IN NORTH CENTRAL CWA ALONG WITH SURFACE CONVERGENCE...SO THAT COULD BE ONE POSSIBLE FOCUS AREA. COULD ALSO SEE SOME BETTER DEVELOPMENT ALONG THE CLOUD EDGE/HEATING DIFFERENTIAL LINE LATER THIS AFTERNOON. PREVIOUS DISCUSSION... NAM SEEMS TO HAVE A DECENT HANDLE ON CONVECTION ACROSS EASTERN KY AND SW WV THIS MORNING...SO HAVE UPDATED POPS ACCORDINGLY. MODELS SHOWING GOOD CONVECTION DEVELOPING ACROSS THE MOUNTAINS THIS AFTERNOON. WITH A SATURATED ATMOSPHERE...CONCERNED ABOUT HEAVY RAINFALL AMOUNTS. MODEL SOUNDINGS SHOWING THAT STORMS WILL HAVE A BIT MORE MOVEMENT THAN TUESDAY...SHOWING ABOUT 5 KTS FOR TODAY. WITH SOME STORM MOVEMENT...NOT INCLINED TO ISSUE A WATCH. WILL HAVE TO KEEP AN EYE ON THE SITUATION THOUGH. && .SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/... BY THU UPR LOW HAS OPENED UP AS IT MOVES INTO NORTHERN MID ATLANTIC STATES AMID BUILDING HEIGHTS SURGING NE FROM DIXIE. THIS WILL USHER IN BEGINNINGS OF MUCH WARMER AIR INTO THE AREA HEADING INTO THE HOLIDAY WEEKEND. ELECTED TO BUMP UP POS IN THE CENTRAL AND NORTHERN MTNS TO LKLY WITH SOME SUN AIDING IN DESTABILIZATION ON ELEVATED HEAT SRC AND PROXIMITY TO SOMEWHAT DEEPER MOISTURE. KEPT SCHC IN FOR FRI...FOR THE MTNS WITH RESIDUAL SE UPSLOPE FLOW AND ELEVATED HEAT SRC. OTHERWISE JUST SOME DAYTIME CU EXPECTED. WILL WATCH A VERY WEAK BOUNDARY DECAY ON APPROACH TO SE OH FRI NIGHT. HAVE KEPT POPS OUT OF THAT AREA GIVEN DRYING AHEAD OF IT. UPR RIDGE FLEXES MUSCLE INTO AREA BY SAT WITH SIGNIFICANT DRYING ALOFT. WILL ALSO WATCH FOR SUBTLE RIPPLE IN FLOW TRAVERSE DOWN RIDGE STAYING JUST NORTH AND WEST OF AREA HOPEFULLY. ELECTED TO PUT SOME SCHC POPS IN FOR MTNS THOUGH GIVEN PROXIMITY TO THIS FEATURE AND ELEVATED HEAT SRC EFFECTS. WARMUP BEGINS ON THU AND REALLY CRANKS FRI AND SAT. WITH RAINFALL EARLY THIS WEEK AND H85 TEMPS ONLY ARND 18C...HARD PRESSED TO BITE ON THE MID 90S FROM THE GFS FOR FRI AND SAT. HAVE HELD MAX T 90-92F RANGE OUTSIDE OF THE MTNS FOR NOW. NIGHT TIME LOWS WILL BE QUITE MILD AS WELL. && .LONG TERM /SUNDAY THROUGH TUESDAY/... UPPER RIDGE FIRMLY IN CONTROL OVER THE DEEP SOUTH...OHIO VALLEY...AND CENTRAL AND SOUTHERN APPALACHIANS FOR THE BEGINNING OF THE EXTENDED. AS HAS BEEN ADVERTISED...THIS WEEKEND WILL BRING THE HIGHEST TEMPERATURES SO FAR THIS CALENDAR YEAR. 850MB TEMPERATURES IN THE UPPER TEENS TO NEAR 20C WILL TRANSLATE TO WIDESPREAD LOW TO MID 90S OVER THE LOWLANDS THIS WEEKEND WITH UPPER 70S AND 80S IN THE HIGHER TERRAIN. HPC CAME IN OVER 100F AT HTS THIS WEEKEND...AND APPEARED TO BE THE HIGHEST OF THE GUIDANCE. PREFER THE CONSERVATIVE APPROACH FOR NOW...BUT STILL ON THE HIGHER END OF THE MOS ENSEMBLE NUMBERS. BEING ON THE PERIPHERY OF THE RIDGE...CANNOT KEEP THE FORECAST COMPLETELY DRY...AND INTRODUCE LOW END POPS WITH SOME CONVECTION POTENTIAL BEGINNING SUNDAY. INCREASE THE POPS WITH A COLD FRONT SLATED FOR EARLY NEXT WEEK AS THE UPPER RIDGE RETREATS SOUTHWARD TOWARDS THE GULF OF MEXICO WITH A RETURN INTO THE BETTER FLOW ALOFT. SOME UNCERTAINTY HERE ON THE EXACT TIMING OF THE COLD FRONT PER USUAL BEYOND DAY 5...BUT HAVE REASONABLE CONFIDENCE IN AN AIRMASS CHANGE FORTHCOMING WHICH SHOULD BRING TEMPERATURES BACK DOWN TO NEAR NORMAL BY MID WEEK. THIS IS EVIDENCED IN THE ECMWF 850MB TEMPERATURES COMING BACK DOWN TO THE LOW TEENS. SHOULD BE ABLE TO BETTER ZERO IN ON THE TIMING OF THE COLD FRONT IN UPCOMING FORECASTS...AND WITH THAT...AN INCREASE IN THE POPS ACCORDINGLY. KEEP THE WEATHER IN A DIURNAL REGIME...WITH THUNDER DURING HEATING HOURS AND SHOWERS FOR ANYTHING AT NIGHT. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... THE ATMOSPHERE IS SATURATED WITH MOISTURE AT MOST LEVELS. THIS WILL ALLOW FOR SOME CONTINUED CONVECTION THROUGH THE PERIOD...WITH BEST COVERAGE DURING THE AFTERNOON AND EVENING HOURS. DENSE FOG WILL GRADUALLY BURN OFF BY MID MORNING. A VFR/MVFR STRATUS DECK HAS BEEN FLOATING AROUND THE AREA OVERNIGHT AND SHOULD TRANSITION INTO A BKN MVFR/VFR CUMULUS DECK DURING THE DAYTIME HOURS. SOME DENSE FOG IS POSSIBLE AGAIN TONIGHT...BUT MAY BREAK EARLY DUE TO SOME WINDS STARTING TO PICK UP TOWARD DAY BREAK. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY... FORECAST CONFIDENCE: LOW. ALTERNATE SCENARIOS: TIMING OF SHOWERS/STORMS COULD VARY. WITH THE ATMOSPHERE SATURATED AT MOST LEVELS...CLOUD DECKS COULD FORM AT UNEXPECTED LEVELS. TIMING OF FOG BURNING OFF/LIFTING COULD VARY. TIMING OF SHOWERS/STORMS MAY VARY. FOG AND LOW STRATUS TIMING...INTENSITY...AND DURATION MAY 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 L 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 M H H H H H H H M H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY M M H H H H H H H H H H CKB CONSISTENCY L H H H H H H H H H H H AFTER 12Z THURSDAY... BRIEF IFR POSSIBLE IN THUNDERSTORMS ON THURSDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...RPY/30/26 NEAR TERM...RPY/MZ SHORT TERM...30 LONG TERM...26 AVIATION...RPY
AREA FORECAST DISCUSSION
NWS GOODLAND KS
227 PM MDT WED MAY 23 2012 .SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT) ISSUED AT 1245 PM MDT WED MAY 23 2012 EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW BROAD TROUGH ACROSS THE NORTHERN ROCKIES...WITH WEST/SOUTHWEST FLOW ACROSS THE INTER-MOUNTAIN WEST INTO THE CENTRAL HIGH PLAINS. AT THE SURFACE A COLD FRONT HAS STALLED OVER WESTERN KANSAS...CURRENTLY ACROSS THE EASTERN PART OF THE CWA. A SHORTWAVE TROUGH CURRENTLY OVER THE GREAT BASIN WILL MOVE EAST-NORTHEAST ACROSS NORTH CENTRAL COLORADO AND SOUTHWEST NEBRASKA TONIGHT. SHOWERS/THUNDERSTORMS HAVE ALREADY DEVELOPED AHEAD OF THIS FEATURE ALONG THE FRONT RANGE INTO SOUTHEASTERN WYOMING. THIS ACTIVITY WILL SPREAD SOUTH AND EAST OVER OUR CWA LATER THIS AFTERNOON...WITH COVERAGE INCREASING ACROSS THE NORTHERN PART OF OUR FORECAST AREA THROUGH 06Z. CONVERGENCE ZONE ALONG AND NORTH OF STALLED FRONT COULD ACT AS A FOCUS FOR EARLIER THUNDERSTORM INITIATION LATER THIS AFTERNOON AND EVENING...HOWEVER THIS IS REMOVED FROM LARGE SCALE ASCENT ASSOCIATED WITH SHORTWAVE SO COVERAGE SHOULD BE LIMITED ACROSS THE SOUTH. VERY STRONG SHEAR IS PRESENT ACROSS THE CWA...WITH INSTABILITY DECREASING THE FURTHER NORTH IN THE CWA WHERE TD VALUES IN THE 30-40F RANGE HAVE ADVECTED IN BEHIND THE FRONT. SEVERE CONVECTION SHOULD BE LIMITED TO THE I-70 CORRIDOR THROUGH EARLY EVENING WHERE THE BEST OVERLAP BETWEEN SHEAR/INSTABILITY IS EXPECTED. LATER TONIGHT ELEVATED INSTABILITY COULD COMBINE WITH STRONG UPPER LEVEL DYNAMICS ASSOCIATED WITH THE SHORTWAVE ACROSS SOUTHWEST NEBRASKA TO BRING ADDITIONAL SEVERE CHANCES. SUBSIDENCE QUICKLY BUILDS IN BEHIND DEPARTING SHORTWAVE TROUGH AFTER 06Z...WITH COVERAGE DECREASING FROM THE SOUTHWEST TO THE NORTHEAST THROUGH SUNRISE THURSDAY. .LONG TERM...(THURSDAY THROUGH WEDNESDAY) ISSUED AT 224 PM MDT WED MAY 23 2012 THURSDAY-THURSDAY NIGHT...PV ANOMALY WILL LIFT TO THE NORTH AND EAST OF THE AREA FAIRLY QUICKLY DURING THE MORNING HOURS...WITH MID LEVEL FRONTOGENESIS QUICKLY DIMINISHING AND DEEP LAYER DIV Q FIELDS INDICATE FAIRLY STRONG LARGE SCALE FORCING FOR SUBSIDENCE OVER THE AREA. STILL HAVE A FEW TIMING CONCERNS THOUGH...AND THINK HOLDING ONTO SOME SMALL POPS WARRANTED FOR AT LEAST THE FIRST FEW HOURS OF THE PERIOD. SOUNDINGS SUGGEST THAT WEAK INSTABILITY WILL LINGER ACROSS MUCH OF THE AREA THROUGH THE DAY...AS DIFFERENTIAL TEMP ADVECTION SHOULD LEAD TO THE DEVELOPMENT OF SHALLOW SFC BASED INSTABILITY WITH EQUILIBRIUM LEVELS LESS THAN H5 AT MANY LOCATIONS. ALTHOUGH SUBSIDENCE DIMINISHES IN THE AFTERNOON ACROSS SOUTHERN HALF OF CWA...THINKING ANY AFTERNOON SHOWERS WILL BE STRONGLY DIURNALLY DRIVEN AND THINK OVERALL COVERAGE WILL BE FAIRLY LOW THROUGH THE EARLY EVENING. LARGE SCALE ASCENT WILL ONCE AGAIN WITH STRONG LOW LEVEL WAA DEVELOPING IN RESPONSE TO H3 JET STREAK LIFTING NORTH INTO SOUTHERN SOUTH DAKOTA. SEEMS LIKE RECENT SUITE OF MODELS NOT ALL THAT OPTIMISTIC ABOUT BREAKING OUT PRECIPITATION OVERNIGHT...BUT GIVEN STRONG AND PERSISTENT WAA/ISENTROPIC FORCING STRONG MOISTURE TRANSPORT ABOVE THE SFC...AND SMALL CONDENSATION PRESSURE DEFICITS IN AREA OF NEGATIVE THETA E LAPSE RATES...THINK THE THREAT FOR SHOWERS AND STORMS WILL BE THERE DESPITE CURRENT MODEL QPF OUTPUT. FRIDAY-SATURDAY...WARM FRONT WILL SLOWLY LIFT TO THE NORTH THROUGH THE PERIOD AND WILL NOT ONLY PLAY A BIG ROLE ON POTENTIAL FOR THUNDERSTORMS...IT WILL ALSO HAVE A LARGE ROLE IN TEMPERATURE FORECAST AS POSSIBILITY EXISTS FOR A PRETTY SHARP GRADIENT WITH TEMPS ON FRIDAY. SREF PLUME DATA INDICATING NEARLY A 20 DEGREE SPREAD IN TEMPS FOR MOST LOCATIONS...WITH ABOUT EQUAL CLUSTERING ON EITHER SIDE...MAINLY ON FRIDAY. PLAN ON KEEPING NEAR MEAN VALUES FOR FRIDAY...ALTHOUGH THERE IS MUCH MORE AGREEMENT ON VERY WARM TEMPS ON SATURDAY AND HAVE WARMED TEMPS ACCORDINGLY. GIVEN EXPECTED PRESSURE FALL PATTERN AROUND AREA AND LARGE SCALE FORCING FOR ASCENT BECOMING MAXIMIZED WELL TO THE WEST OF THE AREA...DO NOT ANTICIPATE MUCH OF A NORTHERN MOVEMENT OF THE FRONT...WITH BULK OF CWA REMAINING CLOUDY AND COOL THROUGH THE DAY. THINK THUNDERSTORMS WILL LIKELY BE ONGOING THROUGH THE MORNING HOURS AS PREVIOUSLY MENTIONED WAA PATTERN REMAINS IN PLACE THROUGH THE MORNING HOURS...BEFORE LARGE SUBSIDENCE INVERSION STRENGTHENS DURING THE AFTERNOON SHARPLY INCREASING CINH PROFILES AND ADVECTING MUCH DRIER AIR INTO THE AREA. MODELS CONTINUE TO PRODUCE LIGHT PRECIPITATION AFTER THIS POINT...BUT SOUNDINGS LOOK LIKE ANY PRECIPITATION PROCESSES IN THE LATE AFTERNOON OR EVENING LOOK TO BE VERY SHALLOW/DRIZZLE TYPE PROCESSES AND DO NOT PLAN ON GOING ALONG WITH HIGHER GUIDANCE POPS AT THIS TIME. APPEARS TO BE LOTS OF INSTABILITY DURING THE LATE AFTERNOON AND EVENING ALONG/NORTH OF FRONT...BUT CINH LOOKS VERY STRONG AND GIVEN RIDGING ALOFT DO NOT THINK THIS WILL BE OVERCOME. ON SATURDAY...EXPECT WINDY TO VERY WINDY CONDITIONS TO DEVELOP ACROSS MUCH OF THE AREA DURING THE AFTERNOON WITH STRONGEST WINDS BEHIND DRYLINE IN EASTERN COLORADO...WHERE DEEP MIXED LAYER SHOULD TAP INTO STRONG FLOW ALOFT. WITH TEMPS IN THE 90S...WIND GUSTS APPROACHING 50 KTS AND MIXED TDS SUGGESTING A RAPID DROP OFF IN DEWPOINTS...POTENTIAL EXISTS FOR EXTREMELY CRITICAL FIRE WX CONDITIONS TO DEVELOP. IT IS A BIT TOO FAR IN THE FUTURE TO ISSUE ANY HIGHLIGHTS AT THIS POINT...BUT POTENTIAL FOR FIRE WEATHER AND SIGNIFICANT WINDS IS INCREASING. OTHERWISE...WARM FRONT WILL LIFT TO THE NORTH OUT OF THE AREA DURING THE MORNING HOURS WITH ANY POTENTIAL FOR AFTERNOON THUNDERSTORMS ALONG DRYLINE DURING THE LATE AFTERNOON. WITH DEEP MIXING AND BULK OF PRESSURE FALLS TO THE NORTH OF THE AREA...WOULD EXPECT DRYLINE TO MIX EASTWARD WITH BULK OF CWA IN DRY SECTOR. ENOUGH SPREAD EXISTS TO WARRANT A MORE BROAD BRUSHED APPROACH TO CHANCES ATTM THOUGH AND WITH STRONG FLOW ALOFT THERE WILL BE POTENTIAL FOR AT LEAST A FEW STRONG/SEVERE HIGH BASED STORMS IN THE AFTERNOON. IN THE EXTENDED (SAT NIGHT-WEDNESDAY)...ACTIVE WEATHER PATTERN EXPECTED THROUGH THE PERIOD AS MEDIUM RANGE MODELS SHOWING REASONABLE AGREEMENT IN DEVELOPMENT OF STRONG TROUGH/AMPLIFIED PATTERN ACROSS THE PLAINS THROUGH THE WEEKEND...FOLLOWED BY MORE ZONAL FLOW ALOFT DURING THE BEGINNING OF THE WEEK. WHILE 06Z GEFS DATA SHOWS A RELATIVELY CONSISTENT PATTERN WITH LARGE TROUGH IMPACTING THE AREA DURING THE WEEKEND...MODEL SPREAD/UNCERTAINTY INCREASES DURING THE LATER HALF AS THERE APPEARS TO BE A DECENT AMOUNT OF DISCREPANCY WITH SMALL SCALE FEATURES. BEST CHANCE FOR PRECIPITATION WILL LIKELY BE ON SUNDAY AFTERNOON AS COLD FRONT SLOWLY MOVES ACROSS THE AREA PROVIDING AMPLE FORCING TO FOCUS THUNDERSTORM DEVELOPMENT. WITH LIGHT EASTERLY/UPSLOPE FLOW AND SEVERAL FAST MOVING SHORT WAVE TROUGHS MOVING THROUGH ZONAL FLOW...PRECIP CHANCES WILL CONTINUE THROUGH THE MIDDLE OF THE WEEK. ASIDE FROM TIMING WITH FROPA ON SUNDAY BRINGING THE POTENTIAL FOR ONE MORE VERY WARM DAY...LOOKS LIKE COOLER CONDITIONS WILL PREVAIL THROUGH THE START OF THE WEEK AS LIGHT EASTERLY FLOW WILL PREVAIL BEHIND COLD FRONT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1107 AM MDT WED MAY 23 2012 VFR CONDITIONS SHOULD PREVAIL AT BOTH KGLD AND KMCK THROUGH THE TAF PERIOD. A COLD FRONT HAS DROPPED SOUTH OF BOTH TERMINALS. WINDS HAVE INCREASED BEHIND THIS FRONT OUT OF THE N-NE TO 15-20KT GUSTING 25-30KT. A DISTURBANCE WILL MOVE FROM NORTHEASTERN COLORADO ACROSS SOUTHWEST NEBRASKA OVERNIGHT TONIGHT. SHOWERS AND THUNDERSTORMS WILL DEVELOP TOWARDS BOTH TERMINALS...WITH THE BEST CHANCES OVER KMCK 04Z-11Z. CHANCES ARE LOWER AT KGLD...THOUGH THERE IS ENOUGH OF A CHANCE THAT THUNDERSTORMS COULD TRACK JUST NORTH OF THE TERMINAL TO CARRY A VCTS GROUP LATE THIS AFTERNOON THOUGH 08Z. SUB VFR CONDITIONS WILL BE POSSIBLE IF A STRONGER STORM WERE TO PASS OVER EITHER TERMINAL. DRY CONDITIONS AND W-NW WINDS AROUND 12KT SHOULD PREVAIL BY SUNRISE AT BOTH TERMINALS. && .FIRE WEATHER... ISSUED AT 224 PM MDT WED MAY 23 2012 VERY WINDY CONDITIONS...WITH GUSTS IN EXCESS OF 50 MPH POSSIBLE...ARE EXPECTED ACROSS A LARGE PORTION OF THE AREA ON SATURDAY. AFTERNOON HUMIDITIES WILL FALL TO AROUND 10 PERCENT ACROSS PORTIONS OF EASTERN COLORADO AND ADJACENT AREAS DURING THE AFTERNOON AS THE WINDS INCREASE. THE COMBINATION OF VERY DRY AND VERY WINDY CONDITIONS WILL BRING THE POTENTIAL FOR EXTREMELY CRITICAL CONDITIONS ON SATURDAY. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...JRM AVIATION...DR FIRE WEATHER...JRM
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
234 PM CDT WED MAY 23 2012 ...UPDATE TO LONG TERM DISCUSSION... .SYNOPSIS... ISSUED AT 1204 PM CDT WED MAY 23 2012 AT 12Z WEDNESDAY A 700MB ELEVATED MIXED LAYER EXTENDED FROM THE PANHANDLE OF OKLAHOMA INTO EXTREME SOUTHWEST NEBRASKA. SOME 700MB MOISTURE WAS LOCATED JUST NORTHWEST OF THIS ELEVATED MIXED LAYER FROM NORTHWEST COLORADO INTO THE PANHANDLE OF NEBRASKA. A SURFACE AND 850MB LOW WAS LOCATED UNDER THIS WARM LAYER IN NORTHWEST KANSAS WITH A DRYLINE EXTENDING SOUTH INTO THE PANHANDLE OF TEXAS. A SURFACE COLD FRONT STRETCHED FROM EASTERN NEBRASKA INTO EASTERN COLORADO. ACROSS THE NORTHWEST UNITED STATES A 500MB THROUGH WAS LOCATED ACROSS MONTANA AND IDAHO WITH AN UPPER LEVEL JET EXTENDING FROM NORTHERN CALIFORNIA INTO NORTHWEST COLORADO. 100-120METER HEIGHT FALLS WERE PRESENT ACROSS NORTHWEST COLORADO AND WYOMING AND THIS WAS LOCATED NEAR THE LEFT EXIT REGION OF THE UPPER LEVEL JET. && .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 142 PM CDT WED MAY 23 2012 NAM, RAP, AND HRRR WERE IN DECENT AGREEMENT WITH COLD FRONT EXTENDING FROM NORTH CENTRAL KANSAS INTO EXTREME SOUTHWEST KANSAS LATE THIS AFTERNOON AND EARLY THIS EVENING. THIS FRONT WILL BE LOCATED UNDER +14C TO +16C 700MB TEMPERATURES. IN ADDITION THE BETTER LOW LEVEL MOISTURE IS STILL FORECAST TO BE LOCATED ACROSS CENTRAL KANSAS AND FROM NORTHWEST KANSAS INTO SOUTH CENTRAL NEBRASKA. BASED ON MODEL SOUNDINGS THE WARM MID LEVEL TEMPERATURES LATE TODAY/EARLY TONIGHT APPEARS TO SERVE AS A CAP ACROSS MOST OF SOUTHWEST KANSAS. THE POSSIBLE EXCEPTION WILL BE NEAR AND NORTH OF INTERSTATE 70 IN NORTH CENTRAL KANSAS WERE BETTER LOW LEVEL FRONTOGENESIS AND MOISTURE WILL BE PRESENT. IN ADDITION THIS WILL BE NEAR THE NORTHERN EDGE OF THE WARM MID LEVEL TEMPERATURES. THE NAM EVEN SUGGESTS SOME COOLING OCCURRING IN THE MID LEVEL AFTER 21Z ALONG AND NORTH OF INTERSTATE 70. GIVEN THE COOLER MID LEVEL TEMPERATURES, BETTER LOW LEVEL MOISTURE/FRONTOGENESIS NEAR THE SURFACE BOUNDARY, AND CAPES EARLY TONIGHT GREATER THAN 1000 J/KG WILL GO AHEAD AND KEEP A MENTION OF THUNDERSTORMS NEAR THE SURFACE BOUNDARY. ALSO BASED ON 0-6KM SHEAR FORECAST TO BE AROUND 50 KNOTS ALONG WITH 1000-2000 J/KG THERE WILL BE A CHANCE FOR ANY STORM THAT DOES DEVELOP TO BECOME SEVERE. MAIN HAZARD STILL APPEARS TO BE HAIL UP TO HALF DOLLAR SIZE AND WINDS UP TO 60 MPH. FURTHER WEST...THE CONVECTION DEVELOPING ACROSS NORTHEAST COLORADO IS EXPECTED TO SPREAD EAST EARLY TONIGHT BUT STAY NORTH OF THE INTERSTATE 70 DURING THE OVERNIGHT HOURS. THE COLD POOL THAT IS FORECAST TO DEVELOP WITH THESE STORMS OVERNIGHT SHOULD PUSH THE COLD FRONT SOUTH ACROSS ALL OF SOUTHWEST KANSAS AFTER MIDNIGHT. BY EARLY THURSDAY MORNING THIS COLD FRONT IS EXPECTED TO BE LOCATED ACROSS CENTRAL KANSAS AND NORTHERN OKLAHOMA. BOUNDARY LAYER WINDS BEHIND THIS FRONT ARE FORECAST TO RANGE FROM 30 TO 35 KNOTS AND GIVEN THE TIGHT PRESSURE GRADIENT BEHIND THIS FRONT THE SURFACE WINDS MAY APPROACH ADVISORY CRITERIA FOR A FEW HOURS FOLLOWING THE FRONTAL PASSAGE LATE TONIGHT. AT THIS TIME HAVE DECIDED TO KEEP SUSTAINED WINDS JUST BELOW ADVISORY CRITERIA FOR A FEW HOURS BEHIND THIS FRONT. IN ADDITION TO THE WINDS SOME LOW LEVEL MOISTURE WILL RETURN TO NORTH CENTRAL AND SOUTHWEST KANSAS. THE WRF AND NMM EVEN SUGGESTS SOME LIGHT PRECIPITATION WILL BE POSSIBLE AS THE LOWER LEVELS SATURATES. AT THIS TIME GIVEN THE ISENTROPIC DOWNGLIDE PRESENT AND DEPTH OF THE MOIST LAYER LESS THAN 3000 FEET AM TRENDING AWAY FROM INSERTING PRECIPITATION CHANCES AFTER MIDNIGHT. ON THURSDAY THE GUSTY NORTHWEST WINDS WILL GRADUALLY SUBSIDE BY MID MORNING AS THE COLD FRONT CONTINUES TO MOVE SOUTHEAST ACROSS EASTERN KANSAS AND OKLAHOMA. IN SOUTHEAST COLORADO THIS FRONT IS EXPECTED TO BECOME NEARLY STATIONARY DURING THE DAY WITH SOME ISENTROPIC LIFT/WARM AIR ADVECTION DEVELOPING NORTH OF THIS BOUNDARY BY LATE DAY. THIS MAY BRING AN INCREASE IN MID LEVEL CLOUD COVER LATE DAY TO PORTIONS OF SOUTHWEST KANSAS BASED ON I310 AND I315 ISENTROPIC SURFACES AND 12Z BUFR SOUNDINGS. GIVEN SOME INCREASING CLOUDS LATE DAY AND 850MB TEMPERATURES AT 00Z FRIDAY WILL TREND TOWARDS THE COOLER GUIDANCE IN FAR SOUTHWEST KANSAS NEAR THE OKLAHOMA BORDER WHILE FURTHER NORTH HAVE KEPT HIGHS CLOSER TO THE WARMER 850MB MIX DOWN TEMPERATURES. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 234 PM CDT WED MAY 23 2012 THURSDAY NIGHT: NOT THAT IMPRESSED FOR PROSPECTS OF CONVECTION THURSDAY EVENING. SOME ISENTROPIC LIFT IS EXPECTED ALONG THE 700 HPA BAROCLINIC BOUNDARY ACROSS CENTRAL KANSAS. FORECAST SOUNDINGS FROM THE ECMWF/GFS SHOW THAT THERE MAY BE SOME MID LEVEL CLOUDS, HOWEVER, THE OVERALL PROFILE IS FAIRLY DRY AND CAPPED. WENT AHEAD AND THREW IN SOME SILENT POPS ACROSS MY NORTHERN COUNTIES BUT DISCOUNTED THE WETTER GFS SOLUTION WHICH CONTINUES TO SUFFER FROM OVERALL POOR SYNOPTIC PERFORMANCE. THE 4 KM NAM & ARW/NMM CORES AREN`T TOO CONVINCING EITHER. FRIDAY: THE WARM SECTOR WILL CONTINUE TO SPREAD NORTHWARD DOWNSTREAM OF A SLOWLY PROPAGATING 500 HPA TROUGH FURTHER WEST. TEMPERATURES WARM TO 33 DEG C @ 850 HPA AND 15 DEG C & 700 HPA WITH A WELL MIXED ATMOSPHERE. HAVE WARMED TEMPERATURES TO THE MID TO UPPER 90S DEG F ACROSS THE CENTRAL AND SOUTHERN ZONES AS A RESULT. THE ECMWF IS VERY WARM WITH 102 DEG F FOR DODGE CITY FRIDAY. WILL CONTINUE TO THE TREND UPWARD BUT NOT YET BITE ON THE EXTREME. THERE COULD BE SOME CONVECTION EAST OF THE DRYLINE FRIDAY EVENING BUT WITH SUCH WARM TEMPERATURES AT 700 HPA, WILL NOT GO HIGHER THAN SLIGHT GIVEN THE VERY STOUT EML. ECMWF SHOWS ABOUT 2500 J/KG OF SBCAPE AND 30 TO 40 KT OF SHEAR SO WILL HAVE TO WATCH OUT FOR SEVERE IN LATER FORECASTS. SATURDAY: AMPLIFICATION OF THE WESTERN TROUGH IS EXPECTED SATURDAY. THE 12Z ECMWF IS LESS AGGRESSIVE WITH CONVECTION FOR SATURDAY EVENING ACROSS THE WEST THAN COMPARED TO THE 00Z RUN. THIS IS PROBABLY DUE TO THE CONTINUED STRONG EML FORECAST BY THE MODEL. WILL NOT GO HIGHER THAN SLIGHT POPS IN THE MEANTIME. NOT MUCH UPPER LEVEL SUPPORT AS THE MAIN 250 HPA JET AXIS IS STILL PRETTY FAR WEST. WILL CONTINUE HOT TEMPERATURES IN THE GRIDS WITH MID TO UPPER 90S DEG F EXPECTED ACROSS MUCH OF THE REGION. SUNDAY AND BEYOND: CONVECTIVE PROSPECTS ARE BETTER SUNDAY AS THE RIGHT ENTRANCE REGION OF THE AFOREMENTIONED 250 HPA TRAVERSES ACROSS NW KANSAS. CAA ASSOCIATED WITH THE TROUGH AND LOW TO MID LEVEL COLD POOLS WILL ALLOW FOR A WEAKENING OF THE EML. THE BEST CHANCE FOR CONVECTION APPEARS TO BE ACROSS CENTRAL AND SOUTH CENTRAL KANSAS ALONG AND EASTWARD MIXING DRYLINE. THE THERMODYNAMIC AND KINEMATIC PROFILES ARE SUPPORTIVE OF SEVERE WEATHER. UL FLOW FLATTENS MONDAY AND TUESDAY AS THE ASSOCIATED TROUGH MOVES ACROSS THE CANADIAN PRAIRIES. THIS WILL ALLOW FOR MORE SEASONAL YET ABOVE NORMAL TEMPERATURES ACROSS SW KANSAS. WILL HAVE TO WATCH THE MIDWEEK PERIOD NEXT WEEK AS IT TRANSITIONS INTO MORE OF A MCS PATTERN. DEWPOINTS/MOISTURE COULD BE AN ISSUE THOUGH. HAVE GONE WITH A CLEANED UP VERSION OF ALLBLEND POPS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1204 PM CDT WED MAY 23 2012 GUSTY SOUTH WINDS AT 20 TO 25 KNOTS WILL CONTINUE EARLY THIS AFTERNOON AT HYS AND DDC AS A COLD FRONT SLOWLY MOVES SOUTH INTO NORTH CENTRAL AND WEST CENTRAL KANSAS. NAM, HRRR, AND RAP APPEAR TO HAVE A DECENT HANDLE ON THIS FRONTAL POSITION BASED ON 15Z ANALYSIS SO WILL SO WILL FOLLOW THESE MODELS FOR WINDS THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY TONIGHT. VFR CONDITIONS ARE EXPECTED THROUGH 06Z BUT SOME SCATTERED MVFR CLOUDS WILL BE POSSIBLE BEHIND A COLD FRONT AS IT CROSSES SOUTHWEST KANSAS BETWEEN 06Z AND 09Z. IN ADDITION TO THESE LOW CLOUDS THE WINDS WILL BE ON THE INCREASE BEHIND THIS FRONT. BASED ON THE TIGHT PRESSURE GRADIENT AND 30 TO 40 KNOTS OF BOUNDARY LAYER WINDS THERE WILL BE A PERIOD OF WINDS IN THE 20 TO 25 KNOT RANGE IMMEDIATELY BEHIND THIS FRONT EARLY THURSDAY MORNING. && .PRELIMINARY POINT TEMPS/POPS... DDC 55 83 62 97 / 10 0 10 10 GCK 53 82 60 96 / 10 0 10 10 EHA 56 85 59 96 / 0 0 10 10 LBL 54 85 62 100 / 0 0 10 10 HYS 55 80 59 86 / 30 10 10 20 P28 65 85 67 97 / 0 0 10 20 && .DDC WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR KSZ066-080-081-089- 090. && $$ SYNOPSIS...BURGERT SHORT TERM...BURGERT LONG TERM...SUGDEN AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
151 PM CDT WED MAY 23 2012 ...UPDATED SHORT TERM DISCUSSION... .SYNOPSIS... ISSUED AT 1204 PM CDT WED MAY 23 2012 AT 12Z WEDNESDAY A 700MB ELEVATED MIXED LAYER EXTENDED FROM THE PANHANDLE OF OKLAHOMA INTO EXTREME SOUTHWEST NEBRASKA. SOME 700MB MOISTURE WAS LOCATED JUST NORTHWEST OF THIS ELEVATED MIXED LAYER FROM NORTHWEST COLORADO INTO THE PANHANDLE OF NEBRASKA. A SURFACE AND 850MB LOW WAS LOCATED UNDER THIS WARM LAYER IN NORTHWEST KANSAS WITH A DRYLINE EXTENDING SOUTH INTO THE PANHANDLE OF TEXAS. A SURFACE COLD FRONT STRETCHED FROM EASTERN NEBRASKA INTO EASTERN COLORADO. ACROSS THE NORTHWEST UNITED STATES A 500MB THROUGH WAS LOCATED ACROSS MONTANA AND IDAHO WITH AN UPPER LEVEL JET EXTENDING FROM NORTHERN CALIFORNIA INTO NORTHWEST COLORADO. 100-120METER HEIGHT FALLS WERE PRESENT ACROSS NORTHWEST COLORADO AND WYOMING AND THIS WAS LOCATED NEAR THE LEFT EXIT REGION OF THE UPPER LEVEL JET. && .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 142 PM CDT WED MAY 23 2012 NAM, RAP, AND HRRR WERE IN DECENT AGREEMENT WITH COLD FRONT EXTENDING FROM NORTH CENTRAL KANSAS INTO EXTREME SOUTHWEST KANSAS LATE THIS AFTERNOON AND EARLY THIS EVENING. THIS FRONT WILL BE LOCATED UNDER +14C TO +16C 700MB TEMPERATURES. IN ADDITION THE BETTER LOW LEVEL MOISTURE IS STILL FORECAST TO BE LOCATED ACROSS CENTRAL KANSAS AND FROM NORTHWEST KANSAS INTO SOUTH CENTRAL NEBRASKA. BASED ON MODEL SOUNDINGS THE WARM MID LEVEL TEMPERATURES LATE TODAY/EARLY TONIGHT APPEARS TO SERVE AS A CAP ACROSS MOST OF SOUTHWEST KANSAS. THE POSSIBLE EXCEPTION WILL BE NEAR AND NORTH OF INTERSTATE 70 IN NORTH CENTRAL KANSAS WERE BETTER LOW LEVEL FRONTOGENESIS AND MOISTURE WILL BE PRESENT. IN ADDITION THIS WILL BE NEAR THE NORTHERN EDGE OF THE WARM MID LEVEL TEMPERATURES. THE NAM EVEN SUGGESTS SOME COOLING OCCURRING IN THE MID LEVEL AFTER 21Z ALONG AND NORTH OF INTERSTATE 70. GIVEN THE COOLER MID LEVEL TEMPERATURES, BETTER LOW LEVEL MOISTURE/FRONTOGENESIS NEAR THE SURFACE BOUNDARY, AND CAPES EARLY TONIGHT GREATER THAN 1000 J/KG WILL GO AHEAD AND KEEP A MENTION OF THUNDERSTORMS NEAR THE SURFACE BOUNDARY. ALSO BASED ON 0-6KM SHEAR FORECAST TO BE AROUND 50 KNOTS ALONG WITH 1000-2000 J/KG THERE WILL BE A CHANCE FOR ANY STORM THAT DOES DEVELOP TO BECOME SEVERE. MAIN HAZARD STILL APPEARS TO BE HAIL UP TO HALF DOLLAR SIZE AND WINDS UP TO 60 MPH. FURTHER WEST...THE CONVECTION DEVELOPING ACROSS NORTHEAST COLORADO IS EXPECTED TO SPREAD EAST EARLY TONIGHT BUT STAY NORTH OF THE INTERSTATE 70 DURING THE OVERNIGHT HOURS. THE COLD POOL THAT IS FORECAST TO DEVELOP WITH THESE STORMS OVERNIGHT SHOULD PUSH THE COLD FRONT SOUTH ACROSS ALL OF SOUTHWEST KANSAS AFTER MIDNIGHT. BY EARLY THURSDAY MORNING THIS COLD FRONT IS EXPECTED TO BE LOCATED ACROSS CENTRAL KANSAS AND NORTHERN OKLAHOMA. BOUNDARY LAYER WINDS BEHIND THIS FRONT ARE FORECAST TO RANGE FROM 30 TO 35 KNOTS AND GIVEN THE TIGHT PRESSURE GRADIENT BEHIND THIS FRONT THE SURFACE WINDS MAY APPROACH ADVISORY CRITERIA FOR A FEW HOURS FOLLOWING THE FRONTAL PASSAGE LATE TONIGHT. AT THIS TIME HAVE DECIDED TO KEEP SUSTAINED WINDS JUST BELOW ADVISORY CRITERIA FOR A FEW HOURS BEHIND THIS FRONT. IN ADDITION TO THE WINDS SOME LOW LEVEL MOISTURE WILL RETURN TO NORTH CENTRAL AND SOUTHWEST KANSAS. THE WRF AND NMM EVEN SUGGESTS SOME LIGHT PRECIPITATION WILL BE POSSIBLE AS THE LOWER LEVELS SATURATES. AT THIS TIME GIVEN THE ISENTROPIC DOWNGLIDE PRESENT AND DEPTH OF THE MOIST LAYER LESS THAN 3000 FEET AM TRENDING AWAY FROM INSERTING PRECIPITATION CHANCES AFTER MIDNIGHT. ON THURSDAY THE GUSTY NORTHWEST WINDS WILL GRADUALLY SUBSIDE BY MID MORNING AS THE COLD FRONT CONTINUES TO MOVE SOUTHEAST ACROSS EASTERN KANSAS AND OKLAHOMA. IN SOUTHEAST COLORADO THIS FRONT IS EXPECTED TO BECOME NEARLY STATIONARY DURING THE DAY WITH SOME ISENTROPIC LIFT/WARM AIR ADVECTION DEVELOPING NORTH OF THIS BOUNDARY BY LATE DAY. THIS MAY BRING AN INCREASE IN MID LEVEL CLOUD COVER LATE DAY TO PORTIONS OF SOUTHWEST KANSAS BASED ON I310 AND I315 ISENTROPIC SURFACES AND 12Z BUFR SOUNDINGS. GIVEN SOME INCREASING CLOUDS LATE DAY AND 850MB TEMPERATURES AT 00Z FRIDAY WILL TREND TOWARDS THE COOLER GUIDANCE IN FAR SOUTHWEST KANSAS NEAR THE OKLAHOMA BORDER WHILE FURTHER NORTH HAVE KEPT HIGHS CLOSER TO THE WARMER 850MB MIX DOWN TEMPERATURES. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 356 AM CDT WED MAY 23 2012 MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL TROUGH OF LOW PRESSURE LIFTING NORTHEAST ACROSS NEBRASKA THURSDAY AND INTO THE WESTERN GREAT LAKES REGION THURSDAY NIGHT BRINGING WIDESPREAD PRECIP CHANCES TO THE DAKOTAS SOUTHWARD INTO NEBRASKA, AND POTENTIALLY NORTHERN KANSAS EARLY THURSDAY. AN ATTENDANT COLD FRONT IS PROJECTED TO PUSH SOUTH INTO WESTERN KANSAS SOMETIME EARLY THURSDAY BEFORE STALLING OUT SOMEWHERE GENERALLY ACROSS EXTREME SOUTHERN SOUTHWEST KANSAS OR NORTHERN OKLAHOMA AS A SURFACE LOW DEVELOPS ACROSS NORTHEASTERN NEW MEXICO INTO THE PANHANDLES OF OKLAHOMA AND TEXAS. HOWEVER, THE SURFACE LOW IS PROGGED TO QUICKLY LIFT NORTHEAST ALONG THE ADVANCING FRONTAL BOUNDARY. MEANWHILE, THE GFS AND ECMWF CONTINUE TO SHOW THE BEST DYNAMIC SUPPORT ALOFT REMAINING JUST OFF TO OUR NORTH WITH THE EXIT REGION OF A STRONG +100KT UPPER LEVEL JET CORE LIFTING NORTHEAST OUT OF NORTHERN COLORADO INTO NEBRASKA. ADDITIONALLY, GFS AND ECMWF MODEL SOUNDINGS SHOW A LACK OF INSTABILITY ACROSS MUCH OF SOUTHWEST KANSAS WITH CAPPING A POSSIBLE ISSUE AS WELL. SHOWERS AND THUNDERSTORMS ARE LIKELY TO DEVELOP EARLY THURSDAY ALONG THE ADVANCING FRONTAL BOUNDARY FROM THE UPPER MIDWEST DOWN INTO NEBRASKA, AND JUST POSSIBLY INTO NORTHERN SECTIONS OF KANSAS, BUT CONDITIONS SHOULD REMAIN FAIRLY DRY ACROSS SOUTHWEST KANSAS WITH ONLY AN OUTSIDE SHOT FOR PRECIP ACROSS CENTRAL KANSAS. AS THE FIRST UPPER LEVEL SHORTWAVE LIFTS FURTHER TO THE NORTHEAST FRIDAY, A SECONDARY AND MORE AMPLIFIED UPPER LEVEL TROUGH IS EXPECTED DROP SOUTH OUT OF THE PACIFIC NORTHWEST INTO MUCH OF CALIFORNIA. THIS WILL SET UP A SOUTHWESTERLY FLOW ALOFT ACROSS THE WESTERN HIGH PLAINS THAT WILL PERSIST WELL INTO THE WEEKEND. AS THE UPPER LEVEL TROUGH IN THE FAR WEST CONUS DEEPENS IT WILL ENHANCE THE UPPER LEVEL SOUTHWEST FLOW ACROSS THE WESTERN HIGH PLAINS. IN TURN, THE STALLED FRONTAL BOUNDARY GENERALLY IN THE VICINITY OF THE KANSAS AND OKLAHOMA BORDER, WILL BEGIN TO LIFT BACK NORTH ACROSS SOUTH CENTRAL AND SOUTHWEST KANSAS AS A WARM FRONT FRIDAY AFTERNOON AND EVENING. ALTHOUGH THE FLOW ALOFT WILL REMAIN FAIRLY WEAK, INCREASED LIFT ALONG THE FRONTAL BOUNDARY COULD BE ENOUGH TO SET UP A FEW DEVELOPING SHOWERS AND THUNDERSTORMS ACROSS CENTRAL KANSAS DURING THIS TIME PERIOD. WILL RETAIN THE SLIGHT POPS ACROSS CENTRAL KANSAS. ANOTHER ROUND OF PRECIP CHANCES ARE POSSIBLE ACROSS PORTIONS OF WESTERN KANSAS BOTH DAYS OF THE WEEKEND AS THE UPPER LEVEL TROUGH IN THE FAR WEST BEGINS TO LIFT NORTHEAST ACROSS THE INTERMOUNTAIN WEST. COOLER TEMPERATURES ARE EXPECTED THURSDAY IN WAKE OF A COLD FRONT PROJECTED TO PUSH SOUTH ACROSS WESTERN KANSAS EARLY IN THE DAY. THE NAM, GFS, AND ECWMF SHOW COOLER AIR FILTERING SOUTH INTO THE AREA DURING THE DAY THURSDAY WITH H85 TEMPERATURES FALLING TO THE MID TO UPPER TEENS(C) ACROSS WEST CENTRAL AND CENTRAL KANSAS WITH LOWER TO MID 20S(C) ACROSS SOUTHWEST KANSAS. THE NAM, GFS, AND ECMWF INDICATE DRY LAPSE RATES DEVELOPING BELOW H7 BY MID TO LATE AFTERNOON. SO, LOOK FOR HIGHS UP INTO THE 80S(F) ACROSS SOUTH CENTRAL AND SOUTHWEST KANSAS WITH UPPER 70S(F) A POSSIBILITY IN MORE NORTHERN PORTIONS OF CENTRAL KANSAS. WARMER TEMPERATURES ARE LIKELY ACROSS SOUTH CENTRAL AND SOUTHWEST KANSAS FRIDAY AS THE STALLED FRONTAL BOUNDARY LIFTS BACK NORTH ACROSS WESTERN KANSAS. THERE IS A POSSIBLE ISSUE AS TO HOW FAR BACK NORTH THE FRONT LIFTS BY LATE FRIDAY AFTERNOON THOUGH. THE NAM AND ECMWF SHOW THE FRONT PUSHING BACK NORTH ALMOST TO THE I-70 CORRIDOR WITH H85 TEMPERATURES NEAR 30C ACROSS MUCH OF SOUTHWEST KANSAS TO THE UPPER 20S(C) IN SOUTH CENTRAL KANSAS. THE GFS IS A LITTLE MORE CONSERVATIVE ON HOW FAR NORTH THE BOUNDARY REACHES WITH A LESSER PRONOUNCED WARM UP. STILL, WIDESPREAD 90S(F) ARE LIKELY ACROSS MUCH OF SOUTH CENTRAL AND SOUTHWEST KANSAS WITH ONLY 80S(F) STILL POSSIBLE IN NORTHERN PORTIONS OF CENTRAL KANSAS. TEMPERATURES ARE LIKELY TO REMAIN WELL ABOVE SEASONAL LEVELS THROUGHOUT THE WEEKEND AS THE BUILDING UPPER LEVEL TROUGH IN THE FAR WEST LIFTS NORTHEAST INTO THE ROCKIES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1204 PM CDT WED MAY 23 2012 GUSTY SOUTH WINDS AT 20 TO 25 KNOTS WILL CONTINUE EARLY THIS AFTERNOON AT HYS AND DDC AS A COLD FRONT SLOWLY MOVES SOUTH INTO NORTH CENTRAL AND WEST CENTRAL KANSAS. NAM, HRRR, AND RAP APPEAR TO HAVE A DECENT HANDLE ON THIS FRONTAL POSITION BASED ON 15Z ANALYSIS SO WILL SO WILL FOLLOW THESE MODELS FOR WINDS THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY TONIGHT. VFR CONDITIONS ARE EXPECTED THROUGH 06Z BUT SOME SCATTERED MVFR CLOUDS WILL BE POSSIBLE BEHIND A COLD FRONT AS IT CROSSES SOUTHWEST KANSAS BETWEEN 06Z AND 09Z. IN ADDITION TO THESE LOW CLOUDS THE WINDS WILL BE ON THE INCREASE BEHIND THIS FRONT. BASED ON THE TIGHT PRESSURE GRADIENT AND 30 TO 40 KNOTS OF BOUNDARY LAYER WINDS THERE WILL BE A PERIOD OF WINDS IN THE 20 TO 25 KNOT RANGE IMMEDIATELY BEHIND THIS FRONT EARLY THURSDAY MORNING. && .PRELIMINARY POINT TEMPS/POPS... DDC 57 82 63 93 / 10 0 10 10 GCK 55 81 60 91 / 10 0 10 10 EHA 53 87 59 95 / 0 0 10 10 LBL 56 85 63 95 / 0 0 10 10 HYS 57 80 61 87 / 30 10 10 20 P28 66 85 67 94 / 0 0 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR KSZ066-080-081-089- 090. && $$ SYNOPSIS...BURGERT SHORT TERM...BURGERT LONG TERM...JJOHNSON AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1245 PM MDT WED MAY 23 2012 .SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT) ISSUED AT 1245 PM MDT WED MAY 23 2012 EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW BROAD TROUGH ACROSS THE NORTHERN ROCKIES...WITH WEST/SOUTHWEST FLOW ACROSS THE INTER-MOUNTAIN WEST INTO THE CENTRAL HIGH PLAINS. AT THE SURFACE A COLD FRONT HAS STALLED OVER WESTERN KANSAS...CURRENTLY ACROSS THE EASTERN PART OF THE CWA. A SHORTWAVE TROUGH CURRENTLY OVER THE GREAT BASIN WILL MOVE EAST-NORTHEAST ACROSS NORTHCENTRAL COLORADO AND SOUTHWEST NEBRASKA TONIGHT. SHOWERS/THUNDERSTORMS HAVE ALREADY DEVELOPED AHEAD OF THIS FEATURE ALONG THE FRONT RANGE INTO SOUTHEASTERN WYOMING. THIS ACTIVITY WILL SPREAD SOUTH AND EAST OVER OUR CWA LATER THIS AFTERNOON...WITH COVERAGE INCREASING ACROSS THE NORTHERN PART OF OUR FORECAST AREA THROUGH 06Z. CONVERGENCE ZONE ALONG AND NORTH OF STALLED FRONT COULD ACT AS A FOCUS FOR EARLIER THUNDERSTORM INITIATION LATER THIS AFTERNOON AND EVENING...HOWEVER THIS IS REMOVED FROM LARGE SCALE ASCENT ASSOCIATED WITH SHORTWAVE SO COVERAGE SHOULD BE LIMITED ACROSS THE SOUTH. VERY STRONG SHEAR IS PRESENT ACROSS THE CWA...WITH INSTABILITY DECREASING THE FURTHER NORTH IN THE CWA WHERE TD VALUES IN THE 30-40F RANGE HAVE ADVECTED IN BEHIND THE FRONT. SEVERE CONVECTION SHOULD BE LIMITED TO THE I-70 CORRIDOR THROUGH EARLY EVENING WHERE THE BEST OVERLAP BETWEEN SHEAR/INSTABILITY IS EXPECTED. LATER TONIGHT ELEVATED INSTABILITY COULD COMBINE WITH STRONG UPPER LEVEL DYNAMICS ASSOCIATED WITH THE SHORTWAVE ACROSS SOUTHWEST NEBRASKA TO BRING ADDITIONAL SEVERE CHANCES. SUBSIDENCE QUICKLY BUILDS IN BEHIND DEPARTING SHORTWAVE TROUGH AFTER 06Z...WITH COVERAGE DECREASING FROM THE SOUTHWEST TO THE NORTHEAST THROUGH SUNRISE THURSDAY. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 230 AM MDT WED MAY 23 2012 THURSDAY NIGHT-FRIDAY NIGHT...SHOULD STILL HAVE A SMALL CHANCE FOR PRECIPITATION THURSDAY NIGHT INTO FRIDAY MORNING AS THE THURSDAY AFTERNOON DISTURBANCE LIFTS AWAY FROM THE AREA. NO CHANGES MADE TO FRIDAY NIGHT POPS. HIGH TEMPERATURES ON FRIDAY IN THE 70S EXCEPT LOW TO MID 80S FROM HILL CITY TO CHEYENNE WELLS AND POINTS SOUTH. SATURDAY THROUGH TUESDAY...A LONGWAVE TROUGH WILL SEND SEVERAL SHORTWAVE TROUGHS THROUGH ITS SOUTHWESTERLY UPPER LEVEL FLOW FOR THE FIRST HALF OF THE PERIOD...AND THE PATTERN ALOFT WILL BECOME INCREASINGLY ZONAL FOR THE SECOND HALF. THE PATTERN CONTINUES TO BE ACTIVE...WITH THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS THROUGH MUCH OF THE PERIOD. MAIN CONCERN DURING THE PERIOD IS THE CHANCE FOR POTENTIALLY SEVERE THUNDERSTORMS LATE ON SATURDAY. LATEST GUIDANCE APPEARS TO BE SLOWING DOWN THE TROUGH WHICH WILL PROVIDE SUPPORT FOR STORMS...AND THIS TREND WOULD SUGGEST MENTIONING STORMS IN THE EVENING BUT NOT THE AFTERNOON. A CAP BETWEEN 50 AND 70 J/KG IN THE AFTERNOON MAY ALSO DELAY STORM FORMATION UNTIL THE TROUGH NEARS THE AREA IN THE EVENING...SO HAVE KEPT POPS SILENT DURING THE AFTERNOON AND INCLUDED SLIGHT CHANCES OVERNIGHT. CURRENT THINKING IS THAT THE GREATEST LIKELIHOOD FOR SEVERE STORMS WOULD BE OVER THE EASTERN PORTION OF THE AREA CONSIDERING THE HIGHER INSTABILITY AND STOUT BUT BREAKABLE CAP OUT EAST. A COLD FRONT WILL MOVE EASTWARD INTO THE AREA ON SUNDAY MORNING...BECOMING STATIONARY OVER THE AREA BY SUNDAY AFTERNOON. THE FRONT WILL REMAIN MOSTLY STATIONARY UNTIL MONDAY AFTERNOON WHEN IT MOVES FURTHER EASTWARD AND AWAY FROM THE REGION. HAVE KEPT POPS SILENT ON MONDAY AND MONDAY NIGHT BEHIND THE FRONT. A WARM FRONT WILL LIFT NORTHEASTWARD INTO THE AREA DURING THE DAYTIME ON TUESDAY AND BRING THE CHANCE FOR PRECIP BACK TO THE REGION. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1107 AM MDT WED MAY 23 2012 VFR CONDITIONS SHOULD PREVAIL AT BOTH KGLD AND KMCK THROUGH THE TAF PERIOD. A COLD FRONT HAS DROPPED SOUTH OF BOTH TERMINALS. WINDS HAVE INCREASED BEHIND THIS FRONT OUT OF THE N-NE TO 15-20KT GUSTING 25-30KT. A DISTURBANCE WILL MOVE FROM NORTHEASTERN COLORADO ACROSS SOUTHWEST NEBRASKA OVERNIGHT TONIGHT. SHOWERS AND THUNDERSTORMS WILL DEVELOP TOWARDS BOTH TERMINALS...WITH THE BEST CHANCES OVER KMCK 04Z-11Z. CHANCES ARE LOWER AT KGLD...THOUGH THERE IS ENOUGH OF A CHANCE THAT THUNDERSTORMS COULD TRACK JUST NORTH OF THE TERMINAL TO CARRY A VCTS GROUP LATE THIS AFTERNOON THOUGH 08Z. SUB VFR CONDITIONS WILL BE POSSIBLE IF A STRONGER STORM WERE TO PASS OVER EITHER TERMINAL. DRY CONDITIONS AND W-NW WINDS AROUND 12KT SHOULD PREVAIL BY SUNRISE AT BOTH TERMINALS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...007/CJS AVIATION...DR
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1209 PM CDT WED MAY 23 2012 ...UPDATED SYNOPSIS AND AVIATION DISCUSSION... .SYNOPSIS... ISSUED AT 1204 PM CDT WED MAY 23 2012 AT 12Z WEDNESDAY A 700MB ELEVATED MIXED LAYER EXTENDED FROM THE PANHANDLE OF OKLAHOMA INTO EXTREME SOUTHWEST NEBRASKA. SOME 700MB MOISTURE WAS LOCATED JUST NORTHWEST OF THIS ELEVATED MIXED LAYER FROM NORTHWEST COLORADO INTO THE PANHANDLE OF NEBRASKA. A SURFACE AND 850MB LOW WAS LOCATED UNDER THIS WARM LAYER IN NORTHWEST KANSAS WITH A DRYLINE EXTENDING SOUTH INTO THE PANHANDLE OF TEXAS. A SURFACE COLD FRONT STRETCHED FROM EASTERN NEBRASKA INTO EASTERN COLORADO. ACROSS THE NORTHWEST UNITED STATES A 500MB THROUGH WAS LOCATED ACROSS MONTANA AND IDAHO WITH AN UPPER LEVEL JET EXTENDING FROM NORTHERN CALIFORNIA INTO NORTHWEST COLORADO. 100-120METER HEIGHT FALLS WERE PRESENT ACROSS NORTHWEST COLORADO AND WYOMING AND THIS WAS LOCATED NEAR THE LEFT EXIT REGION OF THE UPPER LEVEL JET. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 345 AM CDT WED MAY 23 2012 THE MOST SIGNIFICANT FORECAST CHALLENGES FOR THE SHORT TERM PERIOD INCLUDE 1) ANTICIPATING HOW HIGH TEMPERATURES WILL RISE IN ADVANCE OF THE COLD FRONT THAT WILL ENTER SOUTHWEST KANSAS LATE THIS MORNING, ESPECIALLY BEHIND THE DRYLINE THAT WILL MIX EASTWARD TO JUST WEST OF DODGE CITY THIS AFTERNOON; 2) EVALUATING THE OCCURRENCE AND COVERAGE OF THUNDERSTORMS THAT SHOULD FORM AS THE MID LEVEL WARM PLUME WEAKENS ALONG THE FRONT IN NORTHERN KANSAS THIS AFTERNOON; 3) EVALUATING THE STRENGTH OF LOW LEVEL WINDS AS THE LOW LEVEL JET MIXES OUT THIS MORNING; AND 4) ANTICIPATING LOW TEMPERATURES BEHIND THE FRONT TONIGHT. THE SURFACE LOW PRESSURE SYSTEM IN NORTHEASTERN COLORADO WILL DROP SOUTHWARD SLOWLY IN THE LEE OF THE ROCKIES AND LIKELY WILL BE CENTERED NEAR ELKHART BY THIS EVENING. A TIGHT PRESSURE GRADIENT WILL PREVAIL ACROSS SOUTH CENTRAL INTO CENTRAL KANSAS TODAY BUT WILL RELAX DURING THE AFTERNOON HOURS AS THE COLD FRONT BECOMES NEARLY STATIONARY FROM NORTH CENTRAL KANSAS INTO SOUTHEASTERN COLORADO. WINDS LIKELY WILL REACH ADVISORY CRITERIA FOR AT LEAST A FEW HOURS IN SOUTH CENTRAL KANSAS FROM MID MORNING INTO THE AFTERNOON HOURS. A DRYLINE WILL MIX EASTWARD IN THE DOWNSLOPE FLOW SOUTH OF THE SURFACE CYCLONE, AND TEMPERATURES THIS AFTERNOON WILL BE ANOMALOUSLY HOT, ESPECIALLY IN THE DRY AIR IN FAR SOUTHWEST KANSAS. HIGHS LIKELY WILL EXCEED 100 DEGREES WEST OF THE DRYLINE WITH A PLUME OF UPPER 90 DEGREE TEMPERATURES JUST AHEAD OF THE COLD FRONT. THE UPPER LEVEL TROUGH IN IDAHO WILL PROPAGATE RAPIDLY EASTWARD TO WESTERN NEBRASKA BY MID AFTERNOON. SYNOPTIC SCALE UPWARD VERTICAL MOTION WITH THE UPPER LEVEL TROUGH WILL SERVE TO WEAKEN MID LEVEL INVERSION IN NORTHERN KANSAS, AND SCATTERED THUNDERSTORMS ARE LIKELY TO DEVELOP ALONG THE FRONT FROM SOUTHERN NEBRASKA INTO NORTHERN KANSAS. THERE IS SOME UNCERTAINTY ABOUT HOW FAR SOUTH INTO THE WARM MID LEVEL AIR THE CONVECTION WILL UNZIP THIS EVENING. THE NMM IS CONSIDERABLY MORE AGGRESSIVE WITH THUNDERSTORM DEVELOPMENT THAN THE ADVANCED RESEARCH WRF OR THE RAP. MODEL SOUNDINGS FROM THE NAM SUGGEST THAT CONVECTION WILL BE CAPPED UNTIL LATE AFTERNOON, BUT THE INVERSION ERODES BETWEEN 00Z AND 03Z. BULK SHEAR IN THE 0 TO 6KM LAYER IS IN EXCESS OF 50 KNOTS, AND SUFFICIENT INSTABILITY WILL BE PRESENT TO SUPPORT HAIL AND WIND POTENTIAL. THE TEMPERATURE PROFILE IS NOT SUPPORTIVE OF HUGE HAIL, BUT SOMETHING IN THE QUARTER TO HALF DOLLAR SIZE SEEMS REASONABLE. SEVERE WORDING WAS INCLUDED ALONG THE FRONT INTO THE EARLY EVENING HOURS. THE JET STREAK IN THE EASTERN PACIFIC WILL SURGE INTO THE CENTRAL ROCKIES BY 12Z THURSDAY, AND THE SURFACE CYCLONE WILL MOVE INTO EASTERN KANSAS. THE AGEOSTROPHIC CIRCULATION IN THE EXIT REGION OF THE JET WILL SUPPORT CONTINUED UPWARD VERTICAL MOTION BEHIND THE FRONT FROM NORTHEAST COLORADO INTO NEBRASKA, AND THUNDERSTORMS ARE LIKELY TO CONTINUE MUCH OF THE NIGHT. OUTFLOW FROM THE PRECIPITATION AREA WILL ENHANCE BAROCLINICITY WITH THE COLD FRONT, AND TEMPERATURES PROBABLY WILL DROP INTO THE 50S BY THURSDAY MORNING ACROSS MUCH OF SOUTHWEST KANSAS. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 356 AM CDT WED MAY 23 2012 MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL TROUGH OF LOW PRESSURE LIFTING NORTHEAST ACROSS NEBRASKA THURSDAY AND INTO THE WESTERN GREAT LAKES REGION THURSDAY NIGHT BRINGING WIDESPREAD PRECIP CHANCES TO THE DAKOTAS SOUTHWARD INTO NEBRASKA, AND POTENTIALLY NORTHERN KANSAS EARLY THURSDAY. AN ATTENDANT COLD FRONT IS PROJECTED TO PUSH SOUTH INTO WESTERN KANSAS SOMETIME EARLY THURSDAY BEFORE STALLING OUT SOMEWHERE GENERALLY ACROSS EXTREME SOUTHERN SOUTHWEST KANSAS OR NORTHERN OKLAHOMA AS A SURFACE LOW DEVELOPS ACROSS NORTHEASTERN NEW MEXICO INTO THE PANHANDLES OF OKLAHOMA AND TEXAS. HOWEVER, THE SURFACE LOW IS PROGGED TO QUICKLY LIFT NORTHEAST ALONG THE ADVANCING FRONTAL BOUNDARY. MEANWHILE, THE GFS AND ECMWF CONTINUE TO SHOW THE BEST DYNAMIC SUPPORT ALOFT REMAINING JUST OFF TO OUR NORTH WITH THE EXIT REGION OF A STRONG +100KT UPPER LEVEL JET CORE LIFTING NORTHEAST OUT OF NORTHERN COLORADO INTO NEBRASKA. ADDITIONALLY, GFS AND ECMWF MODEL SOUNDINGS SHOW A LACK OF INSTABILITY ACROSS MUCH OF SOUTHWEST KANSAS WITH CAPPING A POSSIBLE ISSUE AS WELL. SHOWERS AND THUNDERSTORMS ARE LIKELY TO DEVELOP EARLY THURSDAY ALONG THE ADVANCING FRONTAL BOUNDARY FROM THE UPPER MIDWEST DOWN INTO NEBRASKA, AND JUST POSSIBLY INTO NORTHERN SECTIONS OF KANSAS, BUT CONDITIONS SHOULD REMAIN FAIRLY DRY ACROSS SOUTHWEST KANSAS WITH ONLY AN OUTSIDE SHOT FOR PRECIP ACROSS CENTRAL KANSAS. AS THE FIRST UPPER LEVEL SHORTWAVE LIFTS FURTHER TO THE NORTHEAST FRIDAY, A SECONDARY AND MORE AMPLIFIED UPPER LEVEL TROUGH IS EXPECTED DROP SOUTH OUT OF THE PACIFIC NORTHWEST INTO MUCH OF CALIFORNIA. THIS WILL SET UP A SOUTHWESTERLY FLOW ALOFT ACROSS THE WESTERN HIGH PLAINS THAT WILL PERSIST WELL INTO THE WEEKEND. AS THE UPPER LEVEL TROUGH IN THE FAR WEST CONUS DEEPENS IT WILL ENHANCE THE UPPER LEVEL SOUTHWEST FLOW ACROSS THE WESTERN HIGH PLAINS. IN TURN, THE STALLED FRONTAL BOUNDARY GENERALLY IN THE VICINITY OF THE KANSAS AND OKLAHOMA BORDER, WILL BEGIN TO LIFT BACK NORTH ACROSS SOUTH CENTRAL AND SOUTHWEST KANSAS AS A WARM FRONT FRIDAY AFTERNOON AND EVENING. ALTHOUGH THE FLOW ALOFT WILL REMAIN FAIRLY WEAK, INCREASED LIFT ALONG THE FRONTAL BOUNDARY COULD BE ENOUGH TO SET UP A FEW DEVELOPING SHOWERS AND THUNDERSTORMS ACROSS CENTRAL KANSAS DURING THIS TIME PERIOD. WILL RETAIN THE SLIGHT POPS ACROSS CENTRAL KANSAS. ANOTHER ROUND OF PRECIP CHANCES ARE POSSIBLE ACROSS PORTIONS OF WESTERN KANSAS BOTH DAYS OF THE WEEKEND AS THE UPPER LEVEL TROUGH IN THE FAR WEST BEGINS TO LIFT NORTHEAST ACROSS THE INTERMOUNTAIN WEST. COOLER TEMPERATURES ARE EXPECTED THURSDAY IN WAKE OF A COLD FRONT PROJECTED TO PUSH SOUTH ACROSS WESTERN KANSAS EARLY IN THE DAY. THE NAM, GFS, AND ECWMF SHOW COOLER AIR FILTERING SOUTH INTO THE AREA DURING THE DAY THURSDAY WITH H85 TEMPERATURES FALLING TO THE MID TO UPPER TEENS(C) ACROSS WEST CENTRAL AND CENTRAL KANSAS WITH LOWER TO MID 20S(C) ACROSS SOUTHWEST KANSAS. THE NAM, GFS, AND ECMWF INDICATE DRY LAPSE RATES DEVELOPING BELOW H7 BY MID TO LATE AFTERNOON. SO, LOOK FOR HIGHS UP INTO THE 80S(F) ACROSS SOUTH CENTRAL AND SOUTHWEST KANSAS WITH UPPER 70S(F) A POSSIBILITY IN MORE NORTHERN PORTIONS OF CENTRAL KANSAS. WARMER TEMPERATURES ARE LIKELY ACROSS SOUTH CENTRAL AND SOUTHWEST KANSAS FRIDAY AS THE STALLED FRONTAL BOUNDARY LIFTS BACK NORTH ACROSS WESTERN KANSAS. THERE IS A POSSIBLE ISSUE AS TO HOW FAR BACK NORTH THE FRONT LIFTS BY LATE FRIDAY AFTERNOON THOUGH. THE NAM AND ECMWF SHOW THE FRONT PUSHING BACK NORTH ALMOST TO THE I-70 CORRIDOR WITH H85 TEMPERATURES NEAR 30C ACROSS MUCH OF SOUTHWEST KANSAS TO THE UPPER 20S(C) IN SOUTH CENTRAL KANSAS. THE GFS IS A LITTLE MORE CONSERVATIVE ON HOW FAR NORTH THE BOUNDARY REACHES WITH A LESSER PRONOUNCED WARM UP. STILL, WIDESPREAD 90S(F) ARE LIKELY ACROSS MUCH OF SOUTH CENTRAL AND SOUTHWEST KANSAS WITH ONLY 80S(F) STILL POSSIBLE IN NORTHERN PORTIONS OF CENTRAL KANSAS. TEMPERATURES ARE LIKELY TO REMAIN WELL ABOVE SEASONAL LEVELS THROUGHOUT THE WEEKEND AS THE BUILDING UPPER LEVEL TROUGH IN THE FAR WEST LIFTS NORTHEAST INTO THE ROCKIES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1204 PM CDT WED MAY 23 2012 GUSTY SOUTH WINDS AT 20 TO 25 KNOTS WILL CONTINUE EARLY THIS AFTERNOON AT HYS AND DDC AS A COLD FRONT SLOWLY MOVES SOUTH INTO NORTH CENTRAL AND WEST CENTRAL KANSAS. NAM, HRRR, AND RAP APPEAR TO HAVE A DECENT HANDLE ON THIS FRONTAL POSITION BASED ON 15Z ANALYSIS SO WILL SO WILL FOLLOW THESE MODELS FOR WINDS THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY TONIGHT. VFR CONDITIONS ARE EXPECTED THROUGH 06Z BUT SOME SCATTERED MVFR CLOUDS WILL BE POSSIBLE BEHIND A COLD FRONT AS IT CROSSES SOUTHWEST KANSAS BETWEEN 06Z AND 09Z. IN ADDITION TO THESE LOW CLOUDS THE WINDS WILL BE ON THE INCREASE BEHIND THIS FRONT. BASED ON THE TIGHT PRESSURE GRADIENT AND 30 TO 40 KNOTS OF BOUNDARY LAYER WINDS THERE WILL BE A PERIOD OF WINDS IN THE 20 TO 25 KNOT RANGE IMMEDIATELY BEHIND THIS FRONT EARLY THURSDAY MORNING. && .PRELIMINARY POINT TEMPS/POPS... DDC 98 57 82 63 / 0 10 0 10 GCK 96 55 81 60 / 10 10 0 10 EHA 99 53 87 59 / 0 0 0 10 LBL 103 56 85 63 / 0 0 0 10 HYS 97 57 80 61 / 30 30 10 10 P28 95 66 85 67 / 0 0 0 10 && .DDC WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 6 PM CDT THIS EVENING FOR KSZ066-080-081-089- 090. && $$ SYNOPSIS...BURGERT SHORT TERM...RUTHI LONG TERM...JJOHNSON AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
118 PM CDT WED MAY 23 2012 .DISCUSSION... FOR THE 18Z TAF PACKAGE. && .AVIATION... VFR EXPECTED TO PREVAIL TODAY AMID FAIR WEATHER CU BASED A0A 3K FT. SOUTH WINDS HAVE BEGUN TO INCREASE AS THE GRADIENT ACROSS THE AREA TIGHTENS BETWEEN HIGH PRESSURE TO THE EAST AND LOW PRESSURE OVER THE PLAINS. WINDS EXPECTED TO SETTLE DOWN THIS EVENING...WITH MVFR VSBYS DEVELOPING OVER SOUTH CENTRAL LOUISIANA DURING THE OVERNIGHT/EARLY MORNING HOURS. VFR TO PREVAIL ELSEWHERE. 13 && .PREV DISCUSSION... /ISSUED 1107 AM CDT WED MAY 23 2012/ UPDATE...HAVE GONE AHEAD AND ADDED ISOLATED THUNDERSTORMS INTO THE FORECAST FOR THIS AFTERNOON FOR THE NORTHEAST AND EASTERN PORTIONS OF THE FORECAST AREA. CAPES PROGGED TO ADVANCE INTO A 2500-3000 J/KG RANGE ACROSS THIS AREA AS WARM FRONT RETREATS NORTHEAST. RUC13 SHOWING DECENT LOW LEVEL CONVERGENCE SETTING UP WITH LITTLE OR NO CAPPING IN PLACE. COULD NOT RULE OUT PULSE SEVERE SHOULD ACTIVITY DEVELOP. MARCOTTE PREV DISCUSSION... /ISSUED 440 AM CDT WED MAY 23 2012/ DISCUSSION... 12Z TAF ISSUANCE. AVIATION... ONLY ISSUE THIS MORNING WILL BE INTERMITTENT MVFR/IFR VSBY FOR LCH/LFT/ARA THRU 13Z. THE TIGHTENING PRESSURE GRADIENT OVER SE TX/SW LA WILL YIELD SSW WINDS 12-14 KTS WITH GUSTS OVER 20 KTS FOR BPT/LCH LATER THIS MORNING INTO THE AFTERNOON. FURTHER EAST...WINDS WILL BE JUST A TAD LESS...STILL EXPECTING TO RANGE 8-12 KTS. OTHERWISE...VFR EXPECTED. DML PREV DISCUSSION... /ISSUED 357 AM CDT WED MAY 23 2012/ DISCUSSION... SFC ANALYSIS SHOWS A FRONTAL BOUNDARY BISECTING THE FORECAST AREA ALONG AN ESE-WNW LINE THIS MORNING. WATER VAPOR IMAGERY SHOWS RIDGING SETTING UP OVER THE CNTL CONUS ALTHOUGH A WEAK SHORTWAVE RIDING OVER THE RIDGE CROSSING SERN TX. LOCAL RADARS ARE PPINE ALTHOUGH REGIONAL 88DS SHOW A FEW SHOWERS/STORMS SETTING UP ALONG THE LAND BREEZE OVER THE NEAR SHORE WATERS OF SERN LA. BASICALLY A PERSISTENT FORECAST IN PLACE THIS MORNING. INSERTED PATCHY FOG WORDING FOR THIS MORNING ACROSS THE FORECAST AREA AS VARIOUS SFC OBS HAVE SHOWN SLIGHT RESTRICTIONS TO VISIBILITIES THROUGH THE NIGHT...AND THESE ARE LIKELY TO LOWER SOME AROUND OR JUST AFTER SUNRISE. THEREAFTER A FEW SHOWERS OR STORMS ARE POSSIBLE MAINLY THIS AFTERNOON AS OUR AIRMASS REMAINS SOMEWHAT MOIST THOUGH NO LAYERS THROUGH THE COLUMN EVEN APPROACH SATURATION. HOWEVER BETTER CAPPING IS EXPECTED TODAY AS THE RIDGE ALOFT BUILDS OVER THE CNTL GULF COAST REGION WHICH SHOULD LIMIT CONVECTION...AND POPS ARE LIMITED TO THE SILENT 10 NEIGHBORHOOD. POPS FURTHER DIMINISH INTO THE WEEKEND AS THE RIDGE GAINS A BETTER GRIP ALOFT...FURTHER STRENGTHENING THE CAP AND REALLY PUTTING A LID ON CONVECTIVE DEVELOPMENT. RISING HEIGHTS ALOFT WILL ALSO LEAD TO A LITTLE WARMING WITH MAX TEMPS ALREADY RUNNING ABOVE MOS NUMBERS BY A DEGREE OR TWO...AND THIS TREND WILL CONTINUE. POPS FINALLY RETURN TO THE FORECAST BY EARLY NEXT WEEK AS A STRONG SHORTWAVE CROSSING THE NRN TIER OF THE CONUS BREAKS DOWN THE RIDGE AND A WEAKNESS DEVELOPS OVER THE NWRN GULF. TEMPS WILL ALSO BEGIN TO MODERATE JUST SLIGHTLY AT THIS TIME...EXPECTED TO REMAIN IN THE LOWER 90S. MARINE... A TIGHTENING PRESSURE GRADIENT THANKS TO LOW PRESSURE DEEPENING OVER THE PLAINS STATES WILL LEAD TO CAUTION CRITERIA SRLY WINDS OVER THE WRN WATERS BY LATE AFTERNOON...SPREADING EWD THROUGH THE EVENING. SCA WINDS ARE POSSIBLE OVER THE WRN WATERS BY LATE TONIGHT BEFORE THE LOW DEPARTS AND HIGH PRESSURE BEGINS TO BUILD BACK OVER THE NRN GULF. THEREAFTER MAINLY LIGHT SRLY TO SOMETIMES ERLY FLOW EXPECTED TO LINGER WITH HIGH PRESSURE REMAINING IN CONTROL. && .PRELIMINARY POINT TEMPS/POPS... KLCH 91 71 91 73 91 / 10 10 10 0 10 KBPT 91 72 91 74 91 / 10 10 10 0 10 KAEX 93 67 93 69 93 / 20 10 10 0 10 KLFT 91 70 91 72 91 / 20 10 10 0 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1107 AM CDT WED MAY 23 2012 .UPDATE...HAVE GONE AHEAD AND ADDED ISOLATED THUNDERSTORMS INTO THE FORECAST FOR THIS AFTERNOON FOR THE NORTHEAST AND EASTERN PORTIONS OF THE FORECAST AREA. CAPES PROGGED TO ADVANCE INTO A 2500-3000 J/KG RANGE ACROSS THIS AREA AS WARM FRONT RETREATS NORTHEAST. RUC13 SHOWING DECENT LOW LEVEL CONVERGENCE SETTING UP WITH LITTLE OR NO CAPPING IN PLACE. COULD NOT RULE OUT PULSE SEVERE SHOULD ACTIVITY DEVELOP. && MARCOTTE && .PREV DISCUSSION... /ISSUED 440 AM CDT WED MAY 23 2012/ DISCUSSION... 12Z TAF ISSUANCE. AVIATION... ONLY ISSUE THIS MORNING WILL BE INTERMITTENT MVFR/IFR VSBY FOR LCH/LFT/ARA THRU 13Z. THE TIGHTENING PRESSURE GRADIENT OVER SE TX/SW LA WILL YIELD SSW WINDS 12-14 KTS WITH GUSTS OVER 20 KTS FOR BPT/LCH LATER THIS MORNING INTO THE AFTERNOON. FURTHER EAST...WINDS WILL BE JUST A TAD LESS...STILL EXPECTING TO RANGE 8-12 KTS. OTHERWISE...VFR EXPECTED. DML PREV DISCUSSION... /ISSUED 357 AM CDT WED MAY 23 2012/ DISCUSSION... SFC ANALYSIS SHOWS A FRONTAL BOUNDARY BISECTING THE FORECAST AREA ALONG AN ESE-WNW LINE THIS MORNING. WATER VAPOR IMAGERY SHOWS RIDGING SETTING UP OVER THE CNTL CONUS ALTHOUGH A WEAK SHORTWAVE RIDING OVER THE RIDGE CROSSING SERN TX. LOCAL RADARS ARE PPINE ALTHOUGH REGIONAL 88DS SHOW A FEW SHOWERS/STORMS SETTING UP ALONG THE LAND BREEZE OVER THE NEAR SHORE WATERS OF SERN LA. BASICALLY A PERSISTENT FORECAST IN PLACE THIS MORNING. INSERTED PATCHY FOG WORDING FOR THIS MORNING ACROSS THE FORECAST AREA AS VARIOUS SFC OBS HAVE SHOWN SLIGHT RESTRICTIONS TO VISIBILITIES THROUGH THE NIGHT...AND THESE ARE LIKELY TO LOWER SOME AROUND OR JUST AFTER SUNRISE. THEREAFTER A FEW SHOWERS OR STORMS ARE POSSIBLE MAINLY THIS AFTERNOON AS OUR AIRMASS REMAINS SOMEWHAT MOIST THOUGH NO LAYERS THROUGH THE COLUMN EVEN APPROACH SATURATION. HOWEVER BETTER CAPPING IS EXPECTED TODAY AS THE RIDGE ALOFT BUILDS OVER THE CNTL GULF COAST REGION WHICH SHOULD LIMIT CONVECTION...AND POPS ARE LIMITED TO THE SILENT 10 NEIGHBORHOOD. POPS FURTHER DIMINISH INTO THE WEEKEND AS THE RIDGE GAINS A BETTER GRIP ALOFT...FURTHER STRENGTHENING THE CAP AND REALLY PUTTING A LID ON CONVECTIVE DEVELOPMENT. RISING HEIGHTS ALOFT WILL ALSO LEAD TO A LITTLE WARMING WITH MAX TEMPS ALREADY RUNNING ABOVE MOS NUMBERS BY A DEGREE OR TWO...AND THIS TREND WILL CONTINUE. POPS FINALLY RETURN TO THE FORECAST BY EARLY NEXT WEEK AS A STRONG SHORTWAVE CROSSING THE NRN TIER OF THE CONUS BREAKS DOWN THE RIDGE AND A WEAKNESS DEVELOPS OVER THE NWRN GULF. TEMPS WILL ALSO BEGIN TO MODERATE JUST SLIGHTLY AT THIS TIME...EXPECTED TO REMAIN IN THE LOWER 90S. MARINE... A TIGHTENING PRESSURE GRADIENT THANKS TO LOW PRESSURE DEEPENING OVER THE PLAINS STATES WILL LEAD TO CAUTION CRITERIA SRLY WINDS OVER THE WRN WATERS BY LATE AFTERNOON...SPREADING EWD THROUGH THE EVENING. SCA WINDS ARE POSSIBLE OVER THE WRN WATERS BY LATE TONIGHT BEFORE THE LOW DEPARTS AND HIGH PRESSURE BEGINS TO BUILD BACK OVER THE NRN GULF. THEREAFTER MAINLY LIGHT SRLY TO SOMETIMES ERLY FLOW EXPECTED TO LINGER WITH HIGH PRESSURE REMAINING IN CONTROL. && .PRELIMINARY POINT TEMPS/POPS... KLCH 91 71 91 73 91 / 10 10 10 0 10 KBPT 91 72 91 74 91 / 10 10 10 0 10 KAEX 93 67 93 69 93 / 20 10 10 0 10 KLFT 91 70 91 72 91 / 20 10 10 0 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
429 PM EDT WED MAY 23 2012 .SYNOPSIS... ISSUED AT 427 PM EDT WED MAY 23 2012 WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH OVER THE NW CONUS AND A RIDGE FROM THE CNTRL GREAT LAKES INTO NRN ONTARIO RESULTING IN SW FLOW FROM THE CNTRL PLAINS TO THE UPPER MS VALLEY AND LAKE SUPERIOR. AT THE SFC...SRLY WINDS WERE INCREASING ACROSS THE REGION AHEAD A COLD FRONT EXTENDING THROUGH THE ERN DAKOTAS FROM LOW PRESSURE OVER SRN MANITOBA. AN AREA OF TSRA WAS MOVING NE THROUGH N CNTRL MN SUPPORTED A SHRTWV NEAR THE NOSE OS STRONG 925-850 MB THETA-E ADVECTION. OVER UPPER MI...VIS LOOP AND SFC OBS SHOWED CONSIDERABLE HIGH CLOUDS IN THE BROAD WAA PATTERN AHEAD OF THE FRONT. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 427 PM EDT WED MAY 23 2012 TONIGHT...AS A SHRTWV OVER NW MN LIFTS TO THE NE AND THE NEXT SIGNIFICANT UPSTREAM SHRTWV OVER NEVADA ROTATES THROUGH THE WRN TROF...ANOTHER SFC LOW WILL DEVELOP IN THE PLAINS AND MOVE NNEWD ON COLD FNT ATTENDANT TO FIRST SFC LO DRIFTING THRU NW ONTARIO. EXPECT THAT THE GREATEST CHANCE FOR SHRA/TSRA WILL REMAIN CLOSER TO THE FRONT AND NEAR THE AXIS OF GREATER MOISTURE/INSTABILITY OVER MN AND FAVORABLE UPPER LEVEL DIV WITH THE RIGHT ENTRANCE OF THE JET OVER NW ONTARIO. SO...THE NAM/REGIONAL GEM/ECMWF WERE PREFERRED WITH THE SHRA/TSRA PLACEMENT COMPARED TO THE GFS WHICH SEEMED OVERLY AGGRESSIVE IN PUSHING THE PCPN TO THE EAST. THURSDAY...THE MAIN SHRTWV LIFTS OUT OF THE PLAINS TO THE UPPER MS VALLEY SUPPORTING A CONSOLIDATED SFC LOW TO NEAR KDLH BY 00Z/FRI. GIVEN THE STRENGTHENING DYNAMICS AGAIN TO THE WEST...CONTINUED TO DELAY THE EASTWARD PROGRESSION OF THE SHRA/TSRA INTO UPPER MI TIL MAINLY LATE IN THE DAY. MLCAPE VALUES TO AROUND 1K J/KG WITH AFTERNOON HEATING AND SFC DEWPOINTS NEAR 60 WILL SUPPORT TSRA CHANCES FROM IWD-CMX...MAINLY AFT 21Z. WITH INVERTED V LOOK TO THE SOUNDINGS AND VERY STRONG MAINLY UNIDIRECTIONAL WIND FIELD (700 MB WINDS TO NEAR 70KT)...EXPECT THAT DAMAGING WINDS WILL BE THE MAIN HAZARD WITH ANY TSRA. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 427 PM EDT WED MAY 23 2012 MAIN CONCERN FOR THE LONG TERM PERIOD IS THE SEVERE WEATHER POTENTIAL AT THE BEGINNING OF THE PERIOD. STATIONARY FRONT WILL BE SETUP OVER WRN LK SUPERIOR...WHILE A FAIRLY POTENT SHORTWAVE PUSHING NE ACROSS AT LEAST THE WRN HALF OF THE CWA THURS NIGHT. THIS WILL LEAD TO ONGOING CYCLOGENESIS OVER NW WI DURING THE LATE AFTERNOON AND THE LOW MOVING NNE ACROSS WRN LK SUPERIOR DURING THE EVENING. EXPECT THUNDERSTORMS TO BE ONGOING OVER NW WI AND FAR WRN LK SUPERIOR AT THE START OF THE PERIOD AND THEN MOVE E AND NE AS THE COLD FRONT PUSHES THROUGH THE CWA DURING THE NIGHT. WITH THE STRONG WINDS ALOFT AND THE CYCLOGENESIS...FEEL THAT THERE IS A DECENT CHANCE OF SEVERE WEATHER OVER THE WRN HALF OF THE CWA TOMORROW EVENING. THERE IS A VERY THIN CORRIDOR OF MLCAPE VALUES APPROACHING 500-1000 J/KG OVER THE WRN THIRD OF THE CWA AND INSTABILITY MAY BE THE MAIN LIMITING FACTOR AS STORMS MOVE INTO THE CWA. CAPE FAIRLY SKINNY...NCAPE VALUES AROUND 0.1...SO DON/T EXPECT MUCH MORE THAN MARGINALLY SEVERE HAIL. WIND APPEARS TO BE BIGGEST THREAT WITH THE STORMS. INVERTED V LOOK TO THE SOUNDINGS OVER THE WEST AND DCAPE VALUES OF 600-800 J/KG. STRONG WINDS ALOFT...APPROACHING 70-80KTS AT H700 AND 40-50KTS JUST A COUPLE HUNDRED FEET ABOVE THE SFC...WILL BE AIDED BY A POCKET OF DRY H700-500 AIR AND STEEPER LAPSE RATES. THIS...COMBINED WITH STORM MOTION TO THE NNE AT 65-70KTS ALL POINT TO THE POTENTIAL FOR DAMAGING WINDS WHERE THUNDERSTORMS...AND POTENTIALLY EVEN SHOWERS OCCUR. WITH THE LOW DEVELOPING ALONG THE FRONT POTENTIALLY AFFECTING THE LLVL WIND FIELD...COULD SEE SOME LLVL BACKING OF THE WINDS AND PRODUCE SOME ROTATING UPDRAFTS AND SUPERCELLS...ESPECIALLY OVER NW WI. BUT THE EXPECTED DRY LLVL AIR HELPING PRODUCE AN INVERTED V AND LCL HEIGHTS TOWARDS 3-3.5KFT SHOULD LIMIT TORNADO POTENTIAL THIS FAR N. CURRENT THOUGHT IS BEST CHANCES FOR SEVERE SHOULD BE FROM BARAGA/IRON COUNTIES AND WEST...BUT WITH THE STORM MOTIONS...COULD POTENTIALLY AFFECT MARQUETTE/DICKINSON/MENOMINEE COUNTIES BEFORE HEADING OVER LK SUPERIOR. ADDED DAMAGING WIND THREAT TO THE GRIDS AND MENTIONED IN THE HWO. THIS MATCHES UP WELL WHERE SPC HAS A SLIGHT RISK...WITH HATCHED AREA JUST TO THE SW OF THE CWA. AS THE LOW QUICKLY LIFTS NE...EXPECT BEST FORCING TO QUICKLY DEPART OVERNIGHT AND PULL FORCING WITH IT. IN ADDITION...AS THE COLD FRONT PUSHES EAST INTO THE CNTRL/ERN CWA...THE CAPPING BECOMES STRONGER. WITH THE COMBINATION OF LOOSING FORCING AND MORE UNFAVORABLE ENVIRONMENT...EXPECT THE SHOWERS/THUNDERSTORMS TO DIMINISH AS THEY MOVE INTO THE CNTRL/ERN CWA. 09Z SREF ALSO SHOWING THIS DIMINISHING TREND IN THE 3HR CALIBRATED THUNDERSTORM PROBS...AS THE SHOWERS/THUNDERSTORMS PUSH TO THE NE OVER LK SUPERIOR DURING THE OVERNIGHT HOURS. EXPECT GUSTY SE WINDS IN THE EVENING AHEAD OF THE LOW AND OVER THE KEWEENAW OVERNIGHT BEHIND THE LOW/FRONT. BUMPED UP WINDS SIGNIFICANTLY OVER THE KEWEENAW BEHIND THE LOW AND FRONT...WITH THE STRONG WINDS JUST ABOVE THE SFC /NAM SHOWING 60KTS AT 1.5KFT/. IN ADDITION...GOOD ISALLOBARIC COMPONENT TO THE WINDS OVER THE WEST OVERNIGHT WITH THE INTENSIFYING LOW PUSHING NE. ONLY CONCERN FOR GOING MORE THAN 30-35KTS AT THIS POINT IS AFFECT OF COOLER WATER TEMPS...BUT THAT MAY NOT HAVE MUCH EFFECT OVER THE HIGHER TERRAIN. FRI...GUSTY WRLY WINDS...30-35KTS...IN THE MORNING BEHIND THE LOW. DRIER AIR MOVING IN AND H700 CAP SHOULD LIMIT DEVELOPMENT EVEN WITH WEAK MID-LVL WAVE MOVING THROUGH. DEEP MOISTURE IS LIMITED AND ML/MU CAPE VALUES ARE BELOW 100 JKG WOULD LEAD TO LITTLE/NO PCPN CHANCES. LATEST NAM RUN HAS BACKED OFF ON PCPN AND WILL FOLLOW SUIT WITH REMOVING SLIGHT CHANCES. WILL KEEP SKIES PARTLY/MOSTLY CLOUDY DURING THE AFTN WITH EXPECTED DIURNAL CU DEVELOPMENT. MIXING TO H750 WOULD YIELD HIGHS IN THE 70S...WITH THE HIGHEST VALUES IN THE FAVORED DOWNSLOPE AREAS OF THE CNTRL. WITH THE GUSTY WINDS AND DEEPER MIXING INTO THE LIMITED MOISTURE ALOFT...EXPECT RH VALUES TO FALL TO 30 PERCENT. FIRE WX CONCERNS MAINLY OVER THE CNTRL...WHERE LESS RAIN IS EXPECTED ON THURS NIGHT. FRI NIGHT...WEAK HIGH PRESSURE RIDGE FROM HIGH JUST N OF MN. SFC LOW DEVELOPING IN THE CNTRL PLAINS IN RESPONSE TO DEEP UPPER TROUGH OVER THE WRN CONUS WILL BEGIN TO PUSH A WARM FRONT N TOWARDS THE UPPER GREAT LAKES LATE FRI NIGHT. COULD PRODUCE A FEW SHOWERS TOWARDS THE WI BORDER LATE. CWA WILL BE ON THE E SIDE OF THE UPPER RIDGE AXIS STRETCHING FROM THE OHIO VALLEY TO LK WINNIPEG UNTIL SUN NIGHT. STILL SEVERAL WEAK DISTURBANCES PUSHING THROUGH THE FLOW SAT AFTN THROUGH SUN NIGHT. THE WARM FRONT WILL CONTINUE TO SLOWLY PUSH NE ON SAT...AS IT BATTLES THE HIGH THAT WILL HAVE MOVED EAST OVER ONTARIO. PCPN CHANCES ON SAT WILL LARGELY DEPEND ON HOW FAR N THE FRONT WILL PUSH. BEST CHANCES LOOK TO BE ON SAT NIGHT INTO SUN...AS THE FRONT MOVES INTO NRN WI AND FINALLY INTO UPPER MI BY SUN AFTN. THIS WILL PUT THE BEST WAA FOCUS OVER THE CWA. THERE ARE DECENT MID LEVEL LAPSE RATES...BUT ELEVATED CAPES ARE NOT TOO IMPRESSIVE...SO HAVE CAPPED THUNDER TO CHANCES FOR SAT NIGHT INTO SUN. WITH THE CONVECTION LIKELY TO BE ELEVATED...THE MAIN THREAT WOULD BE SMALL HAIL AND HEAVY RAIN. CWA WILL BE UNDER THE WARM SECTOR LATE SUN AFTN AND INTO SUN NIGHT...WITH MODELS DIVERGING WITH THE HANDLING OF THE LOW HEADING INTO THE FIRST PART OF NEXT WEEK. 12Z GFS SHOWS THE LOW CONTINUING NNE INTO SRN CANADA ON SUN NIGHT AND MONDAY WHILE PUSHING COLD FRONT ACROSS UPPER MI ON MON. 00Z ECMWF ON THE OTHERHAND DISSIPATES THE LOW OVER THE CWA AND THEN SLOWLY SLIDES IT EAST THROUGH TUES. AFTER A MORE ACTIVE PERIOD...OVERALL TREND LOOKS TO BE TOWARDS A SLIGHTLY DRIER/QUIET WEATHER TOWARDS THE MIDDLE OF NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 133 PM EDT WED MAY 23 2012 STRONG SOUTH WINDS WILL BE THE MAIN CONCERN DURING THE TAF PERIOD. WITH THE LOSS OF DAYTIME HEAVINT...LLWS WILL BE LIKELY TONIGHT AT ALL 3 SITES...EVEN WITH IWD KEEPING GUSTS AT OR ABOVE 20KTS THROUGH THE OVERNIGHT HOURS. OTHERWISE...VFR CEILINGS AND VIS SHOULD REMAIN...WITH ONLY SOME LIGHTER SHOWERS POSSIBLE LATE TONIGHT AND EARLY THURSDAY AT IWD. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 427 PM EDT WED MAY 23 2012 LOW PRESSURE OVER S MANITOBA WILL PUSH INTO ONTARIO TONIGHT AND THURSDAY...AS AN ADDITIONAL LOW MOVES FROM THE CENTRAL PLAINS TO W LS FRIDAY AFTERNOON. EXPECT THE LOW TO CONTINUE A NE TRACK ACROSS ONTARIO THROUGH FRIDAY...WITH A TROUGH LINGERING ACROSS LAKE SUPERIOR. STRENGTHENING S WINDS WILL PREVAIL AHEAD OF THIS SYSTEM TONIGHT THROUGH THURSDAY. WITH A STABLE TEMPERATURE PROFILE THE STRONGEST WINDS...EXPECT THE STRONGEST ACROSS THE TALLER OBSERVING PLATFORMS ACROSS CENTRAL LAKE SUPERIOR. HIGH PRESSURE OVER CENTRAL CANADA FRIDAY NIGHT WILL SLIDE ACROSS ONTARIO SATURDAY...BEFORE SETTLING ACROSS HUDSON BAY ON SUNDAY. AS A RESULT...A RIDGE WILL SLIDE ACROSS LS SATURDAY...WITH LIGHTER WINDS TAKING HOLD. A LOW ACROSS THE CENTRAL PLAINS WILL FILL ACROSS MN SUNDAY INTO SUNDAY NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...JLB SHORT TERM...JLB LONG TERM...SRF AVIATION...JLB MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
133 PM EDT WED MAY 23 2012 .SYNOPSIS... ISSUED AT 734 AM EDT WED MAY 23 2012 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG FM THE UPR MS RIVER VALLEY BTWN A TROF OVER THE PAC NW AND ANOTHER IN QUEBEC. AT THE SFC...THERE IS A 996MB LO PRES OVER THE NRN PLAINS ASSOCIATED WITH A SHRTWV/100KT H3 JET MAX LIFTING OUT OF THE WRN TROF. WARM FNT E OF THIS LO RUNS ACRS NRN MN TO NEAR THE CWA/WI BORDER. THERE ARE SOME SCT -SHRA OVER UPR MI N OF THIS WARM FNT EARLY THIS MRNG IN AREA OF SOME ISENTROPIC ASCENT/MSTR BEST SHOWN ON THE 305K SFC /ABOUT H7/...BUT COVERAGE/INTENSITY IS LIMITED BY VERY DRY AIR IN THE WARM SECTOR AS SHOWN ON THE 00Z MPX RAOB AND ALSO THE 00Z GRB RAOB. IN FACT...SFC DEWPTS IN THE WARM SECTOR MIXED OUT TO AROUND 40 OVER IOWA/SRN MN YDAY AFTN WITH HI TEMPS RISING WELL INTO THE 80S. EXCEPT FOR SOME HI CLDS SPILLING E FM SHRA/TS CLOSER TO THE SFC LO...SKIES ARE MOCLR OVER MUCH OF MN/WI S OF THE WARM FNT. && .SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY EVENING) ISSUED AT 734 AM EDT WED MAY 23 2012 MAIN FCST CONCERNS INTO THU ARE MAINLY FIRE WX RELATED FOLLOWING EXPECTED WARM FROPA THIS MRNG. FOCUS FOR LATER THU AND THU NGT TURN TO POPS WITH APRCH OF COLD FNT FM THE W. TODAY...AS SFC LO PRES IN THE NRN PLAINS DRIFTS NEWD TOWARD FAR NW ONTARIO BY 00Z FRI...ATTENDANT WARM FNT WL LIFT NEWD ACRS THE CWA AND INTO ONTARIO THIS AFTN. WITH THIS SHIFT AND DEPARTURE OF DEEPER MSTR ON THE 305K ISENTROPIC SFC TO THE NE...EXPECT LINGERING -SHRA AND THICKER CLDS OVER UPR MI TO LIFT OUT INTO LK SUP EARLY THIS MRNG. ONCE THE WARM SECTOR MOVES INTO THE CWA WITH H85 TEMPS RISING AS HI AS 17-18C...EXPECT HI TEMPS TO TOP OUT 80 TO 85 PER MIXING TO H8 ON FCST SDNGS OVER PORTIONS OF THE W HALF AWAY FM THE MODERATING INFLUENCE OF LK MI. WITH DAYTIME MIXING OUT THE H100-85 WINDS UP TO 30 KTS AND CAUSING SFC DEWPTS TO FALL AS LO AS 37 TO 45 IN THE AFTN PER UPSTREAM OBS YDAY...MIN RH/FIRE WX PARAMETERS WL AT LEAST APRCH CRITICAL LVLS. OPTED TO ISSUE A WILDFIRE POTENTIAL STATEMENT FOR NOW AND LET THE DAYSHIFT COORDINATE WITH THE USERS ON HEADLINES AS NECESSARY. TNGT...AS NEXT SHRTWV ROTATES THRU THE WRN TROF UPSTREAM OF BLDG RDG OVER THE ERN CONUS...ANOTHER SFC LO PRES WL TAKE SHAPE IN THE PLAINS AND MOVE NNEWD ON COLD FNT ATTENDANT TO FIRST SFC LO DRIFTING THRU NW ONTARIO. UNDER THESE CIRCUMSTANCES...THINK THE 00Z NAM AND ESPECIALLY THE GFS ARE TOO PROGRESSIVE PUSHING PCPN INTO THE WRN CWA. SO TENDED TO FOLLOW THE SLOWER 00Z CNDN AND LOCAL WRF-ARW/12Z ECMWF GUIDANCE. EVEN THOUGH SKIES WL REMAIN MOCLR OVER AT LEAST THE E HALF UNDER AXIS OF DRIEST AIR/HIEST H5...STEADY S WIND WL RESTRICT THE DIURNAL TEMP DROP. THE OVERNGT WL BE ESPECIALLY WARM AND RH RECOVER PARTICULARLY POOR OVER THE W IN THE DOWNSLOPE AREAS NEAR LK SUP AND WHERE AT LEAST THICKER HI CLDS WL MOVE OVHD. THU...AS THE PRIME SHRTWV DRIVES NEWD TOWARD THE UPR LKS AND SFC LO SHIFTS NEAR WRN UPR MI...EXPECT INCRSG POPS OVER ESPECIALLY THE W WITH SOME DPVA/H5 FALLS/UPR DVGC IN RRQ OF UPR JET MAX IN NW ONTARIO AND RETURN OF LLVL MSTR IN THE PRESENCE OF DAYTIME HEATING. MOST OF THE MODELS ARE ACTUALLY IN FAIRLY GOOD AGREEMENT ON THESE DETAILS. ALTHOUGH GUIDANCE SUGS MOST OF THE SHRA/TS WL FALL ON THE COLD SIDE OF THE ACCOMPANYING FNT THAT REACHES THE WRN ZNS WITH THE SFC LO LATE IN THE DAY...SPC HAS INCLUDED MUCH OF THE W HALF OF THE CWA IN A SLGT RISK FOR SVR TS. FCST NAM SDNG FOR IWD LATE IN THE DAY INDICATES SBCAPE REACHING ARND 1000J/KG FOR SFC T/TD 79/60 NEAR FROPA TIME. OVERALL LAPSE RATES DO NOT LOOK TOO IMPRESSIVE WITH FAIRLY NARROW SKINNY CAPE...BUT STRONG WIND FIELDS UP TO 60KT/50KT AT H7/H85 AND PRESENCE OF INVERTED V T/TD PROFILE BLO H8 SUG THE POTENTIAL FOR SOME DAMAGING WINDS IF ENUF LLVL MSTR CAN SURGE AHEAD OF THE FNT TO SUPPORT TS COINCIDENT WITH THE FROPA AND NOT JUST ON THE COLD SIDE OF THE BNDRY. FARTHER TO THE E...THE DAY SHOULD BE BREEZY AND WARM...BUT A RETURN OF HIER H85 DEWPTS/MIXING OF THIS MOISTER AIR TO THE SFC SHOULD LIMIT HOW BAD THE FIRE WX PARAMETERS GO. THU NGT...AS SHRTWV/SFC LO DRIVE NEWD THRU ONTARIO...ATTENDANT COLD FNT WL SWEEP ACRS THE CWA...PASSING ERY LATE. SINCE THE SHARPER DVPA/DEEP LYR QVECTOR CNVGC TEND TO LIFT NEWD INTO ONTARIO WITH THE SHRTWV...SUSPECT THE MODELS AND ESPECIALLY THE NAM MIGHT BE ON THE RIGHT TRACK SHOWING A DCRSG TREND FOR FNTL SHRA/TS...ESPECIALLY LATE WITH LOSS OF ANY DIURNAL HEATING. A GUSTY W WIND IN THE WAKE OF THE FROPA WITH WNW H925 WINDS UP TO 40 KTS WL DRIVE COOLER AIR/H85 TEMPS DOWN TO 8C INTO THE CWA OVERNGT. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 528 AM EDT WED MAY 23 2012 WENT WARMER /ABOUT 5F/ AND WINDIER FOR FRIDAY. WHILE MUCH OF THE WARMER AIR AND PRECIP WILL EXIT EAST WITH THE COLD FRONT EXITING EAST IN THE MORNING...THE SFC TROUGH WILL LINGER OVERHEAD WITH WSW WINDS AT THE SFC. EXPECT 850MB TEMPS TO FALL FROM THE MID TEENS C TO AROUND 10C AROUND DAYBREAK FRIDAY...AND REMAIN STEADY AROUND THIS LEVEL THROUGH SATURDAY. COULD NOT GET RID OF PRECIPITATION ALL TOGETHER FOR...GIVEN 120KT 250MB JET STREAMING ACROSS UPPER MICHIGAN...AND A KICKER OF A SHORTWAVE ALOFT. THERE IS SIGNIFICANT TIMING/STRENGTH DIFFERENCES WITH THIS FEATURE. AS A RESULT...THE CHANCE OF PRECIP/TS WAS LIMITED TO SLIGHT CHANCE. THE 23/00Z GFS DOES SHOW AROUND A QUARTER OF AN INCH OF LIQUID CENTRAL DURING THE AFTERNOON HOURS...WHILE THE OTHER MODELS ARE MUCH DRIER. ALTHOUGH HIGH PRESSURE FROM CENTRAL CANADA WILL ATTEMPT TO SINK ACROSS THE UPPER GREAT LAKES FOR SATURDAY...IT WILL BE PUSHED EASTWARD...SKIMMING NORTHERN AND EASTERN UPPER MI SATURDAY INTO SATURDAY NIGHT. MUCH OF THIS WILL BE DUE TO THE NEXT LOW DEVELOPING OVER THE CENTRAL STATES. THE LOW WILL MOVE TO THE DAKOTAS/NE BY SUNDAY AFTERNOON...WITH A WARM FRONT QUICKLY PUSHING UP ACROSS THE CWA AND 850MB TEMPS JUMPING TO AROUND 18C SUNDAY NIGHT INTO MONDAY MORNING. THE 23/00Z GFS IS MORE PROGRESSIVE WITH THE SFC LOW...AVERAGING OUT TO BE ABOUT 6 HOURS QUICKER THAN THE 23/00Z ECMWF FROM SATURDAY NIGHT THROUGH EARLY MONDAY AFTERNOON. THE SLOW MOVING SYSTEM WILL CONTINUE TO INFLUENCE OUR WEATHER THROUGH THE START OF THE NEXT WORK WEEK...WITH A CHANCE OF SHOWERS LINGERING THROUGH MONDAY. TEMPERATURES WILL EVENTUALLY COOL TUESDAY...BACK TO BELOW NORMAL READINGS /MAINLY IN THE 50S TO MID 60S/. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 133 PM EDT WED MAY 23 2012 STRONG SOUTH WINDS WILL BE THE MAIN CONCERN DURING THE TAF PERIOD. WITH THE LOSS OF DAYTIME HEAVINT...LLWS WILL BE LIKELY TONIGHT AT ALL 3 SITES...EVEN WITH IWD KEEPING GUSTS AT OR ABOVE 20KTS THROUGH THE OVERNIGHT HOURS. OTHERWISE...VFR CEILINGS AND VIS SHOULD REMAIN...WITH ONLY SOME LIGHTER SHOWERS POSSIBLE LATE TONIGHT AND EARLY THURSDAY AT IWD. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 528 AM EDT WED MAY 23 2012 LOW PRESSURE OVER S MANITOBA WILL PUSH INTO ONTARIO TONIGHT AND THURSDAY...AS AN ADDITIONAL LOW MOVES FROM THE CENTRAL PLAINS TO W LS FRIDAY AFTERNOON. EXPECT THE LOW TO CONTINUE A NE TRACK ACROSS ONTARIO THROUGH FRIDAY...WITH A TROUGH LINGERING ACROSS LAKE SUPERIOR. STRENGTHENING S WINDS WILL BE THE RULE AHEAD OF THIS SYSTEM TODAY THROUGH TOMORROW...STRONGEST ACROSS THE TALLER OBSERVING PLATFORMS ACROSS CENTRAL LS. HIGH PRESSURE OVER CENTRAL CANADA FRIDAY NIGHT WILL SLIDE ACROSS ONTARIO SATURDAY...BEFORE SETTLING ACROSS HUDSON BAY ON SUNDAY. AS A RESULT...A RIDGE WILL SLIDE ACROSS LS SATURDAY...WITH LIGHTER WINDS TAKING HOLD. A LOW ACROSS THE CENTRAL PLAINS WILL FILL ACROSS MN SUNDAY INTO SUNDAY NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...KC SHORT TERM...KC LONG TERM...KF AVIATION...JLB MARINE...KF
AREA FORECAST DISCUSSION
NWS HASTINGS NE
419 PM CDT WED MAY 23 2012 .UPDATE...SENT AN UPDATE TO THE FORECAST TO INCLUDE SEVERE THUNDERSTORM WATCH 293 FOR PORTIONS OF THE FORECAST AREA THROUGH 11 PM CDT. THE GREATEST POTENTIAL FOR ANY SEVERE STORMS WILL REMAIN WITH AND ALONG EITHER SIDE OF A SLOWLY PROGRESSING COLD FRONT...WITH LARGE HAIL AND DAMAGING WIND GUSTS BEING THE PRIMARY CONCERNS WITH ANY STORMS THAT DO DEVELOP. && .PREV DISCUSSION... /ISSUED 400 PM CDT WED MAY 23 2012/ SHORT TERM...A FAIRLY ACTIVE START TO THE FORECAST IS EXPECTED THIS EVENING AS A COLD FRONT SLOWLY MAKES ITS WAY ACROSS SOUTH CENTRAL NEBRASKA AND NORTH CENTRAL KANSAS...WITH AN ASSOCIATED MID LEVEL LOW PRESSURE SYSTEM TO THE WEST EXPECTED TO HELP BRING SOME WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY ACROSS MUCH OF THE FORECAST AREA DURING THE OVERNIGHT HOURS TONIGHT. SHORT TERM MODELS ARE IN MODERATE DISAGREEMENT WITH INITIATION OF CONVECTION ALONG A PASSING COLD FRONT...CURRENTLY DRAPED FROM NEAR NORFOLK...ACROSS GRAND ISLAND...SOUTH WESTWARD TOWARDS HOLDREGE. THIS FRONT HAS BEEN VERY SLOW TO WORK ITS WAY ACROSS THE FORECAST AREA THIS AFTERNOON...AND SO FAR HAS YET TO PRODUCE ENOUGH FORCING TO BREAK LOW LEVEL CAP. 12Z NAM AND WRF BOTH DID TRY AND INITIATE CONVECTION...BUT 18Z NAM AND LATEST HRRR BOTH HOLD OFF ANY WIDESPREAD SHOWER OR THUNDERSTORM ACTIVITY TILL FORCING FROM MID LEVEL LOW TO OUR WEST APPROACHES CENTRAL NEBRASKA AROUND MIDNIGHT. THAT BEING SAID...INGREDIENTS ARE IN PLACE...AS LATEST MESO ANALYSIS SHOWS A FINGER OF 2000+ J/KG OF CAPE ACROSS THE LOCAL AREA NEAR THE SLOWLY PROGRESSING FRONT...AND LITTLE INHIBITION AS WELL AS DEVELOPING CU FIELD IN SATELLITE. PER CONSENSUS AMONG MODELS...DID BACK OFF ON INITIATION OF CONVECTION THIS AFTERNOON...BUT INSERTED MENTION OF SEVERE STORMS AFTER 00Z...AS COMBINATION OF SHEAR AND INSTABILITY SHOULD BE SUFFICIENT FOR SOME SUPERCELLS TO DEVELOP IF INITIATION CAN BE REALIZED NEAR THE FRONT. BEHIND THE FRONT...AS THE MID LEVEL SHORTWAVE APPROACHES THE REGION...BROADER SCALE FORCING SHOULD BE AMPLE ENOUGH TO DEVELOP WIDESPREAD CONVECTION ACROSS THE LOCAL AREA BY AROUND MIDNIGHT...CONTINUING INTO THE OVERNIGHT HOURS...SO THE POTENTIAL FOR SEVERE HAIL AND STRONG WINDS REMAIN A CONCERN. THEREAFTER...THE ATMOSPHERE SHOULD BEGIN TO STABILIZE BEHIND THE DEPARTING MID LEVEL WAVE...WITH A SMALL CHANCE FOR SHOWERS AND AN ISOLATED THUNDERSTORM CONTINUING INTO THE AFTERNOON HOURS WITH NEAR TO SLIGHTLY BELOW SEASONAL TEMPERATURES EXPECTED DURING THE AFTERNOON. LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY. MAIN FORECAST CONCERNS WILL BE CHANCES FOR THUNDERSTORMS THROUGH MOST OF THE PERIOD AND TEMPERATURES. ZONAL TO SOUTHWEST FLOW GIVES WAY TO NORTHWEST FLOW. THERE ARE SEVERAL WAVES THAT MOVE THROUGH THE AREA DURING THE PERIOD. THE FIRST WAVE MOVES INTO THE AREA THURSDAY NIGHT INTO FRIDAY. THERE WILL BE A CHANCE FOR SOME THUNDERSTORMS. ON FRIDAY A SURFACE LOW DEVELOPING IN KANSAS WILL LIFT A WARM FRONT NORTH INTO THE FORECAST AREA. WITH THE FRONT MOVING THROUGH AND THE ANOTHER UPPER WAVE MOVING INTO THE AREA THERE IS A BETTER CHANCE FOR THUNDERSTORMS. SOME OF THESE STORMS COULD BE STRONG TO SEVERE. SATURDAY AND SATURDAY NIGHT THERE ARE WEAK WAVES THAT MOVES THROUGH BUT LITTLE IN THE WAY TO GET THINGS STARTED SO ANY PRECIPITATION WILL BE SPOTTY. THE NEXT CHANCE FOR SOME THUNDERSTORMS WILL BE SUNDAY INTO SUNDAY NIGHT. ANOTHER STRONGER WAVE MOVES INTO THE AREA AND A COLD FRONT MOVES THROUGH THE AREA SUNDAY AFTERNOON AND EVENING. THUNDERSTORMS WILL DEVELOP ALONG THE FRONT AS IT MOVES THROUGH. SOME OF THESE COULD BE SEVERE. MONDAY AND MONDAY NIGHT THE UPPER WAVE MOVES TO THE EAST AND A SURFACE HIGH PRESSURE MOVES INTO THE AREA...KEEPING THINGS DRY. AGAIN TUESDAY INTO TUESDAY NIGHT THERE ARE A FEW WEAK UPPER LEVEL WAVES THAT MOVE INTO THE PLAINS. MODELS HAVE SOME FAIRLY SPOTTY PRECIPITATION AROUND THE AREA WITH THESE UPPER LEVEL WAVES. THE GFS HAS MORE PRECIPITATION AROUND THAN THE ECMWF DOES. TEMPERATURES WILL BE SOMEWHAT VARIABLE THROUGH THE WEEK. WITH CLOUDS AROUND ON FRIDAY THE TEMPERATURES WILL BE A BIT COOLER...WARMING AFTER THE WARM FRONT LIFTS TO THE NORTH FOR SATURDAY AND SUNDAY THEN COOLING AGAIN AS THE COOL FRONT MOVE THROUGH MONDAY AND TUESDAY AND COOLING MORE AFTER THE FRONT MOVES THROUGH TUESDAY. PREV DISCUSSION... /ISSUED 106 PM CDT WED MAY 23 2012/ AVIATION...18Z KGRI TAF...GUSTY SOUTHERLY WINDS AND VFR CONDITIONS WILL CONTINUE AT KGRI FOR THE NEXT FEW HOURS AS A COLD FRONT APPROACHES THE TERMINAL FROM THE NORTHWEST. THIS FRONT IS MAKING VERY SLOW PROGRESS TOWARDS THE SOUTHEAST...PRESENTLY STRETCHING FROM NEAR ORD TO LEXINGTON. WITH THE SLOW PROGRESSION OF THIS FRONT...HELD OFF ON A WIND SHIFT AT THE TERMINAL UNTIL 23/21Z...WITH GUSTY NORTHERLY WINDS AND A FEW SHOWERS EXPECTED THEREAFTER. AFT 24/00Z...EXPECT CIGS BEGIN TO LOWER TO NEAR MVFR LEVELS...WITH AN INCREASING CHANCE FOR -SHRAS AND -TSRAS. BEST FORCING FOR MORE PERSISTENT SHOWER AND THUNDERSTORM ACTIVITY IS AROUND MIDNIGHT TONIGHT...AND INTRODUCED A TEMPO GROUP AROUND THIS PERIOD FOR MORE PREVALENT MVFR CIGS AND VSBYS...BUT THAT SAID...EXPECT AT LEAST SOME SHRAS AND TSRAS IN THE VICINITY OF THE TERMINAL...SOME OF WHICH COULD CONTAIN LARGE HAIL AND SEVERE WIND GUSTS...TO BE PRESENT FROM THE EVENING HOURS TONIGHT THROUGH THE MORNING HOURS THURSDAY. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM/AVIATION/UPDATE...ROSSI LONG TERM...JCB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
400 PM CDT WED MAY 23 2012 .SHORT TERM...A FAIRLY ACTIVE START TO THE FORECAST IS EXPECTED THIS EVENING AS A COLD FRONT SLOWLY MAKES ITS WAY ACROSS SOUTH CENTRAL NEBRASKA AND NORTH CENTRAL KANSAS...WITH AN ASSOCIATED MID LEVEL LOW PRESSURE SYSTEM TO THE WEST EXPECTED TO HELP BRING SOME WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY ACROSS MUCH OF THE FORECAST AREA DURING THE OVERNIGHT HOURS TONIGHT. SHORT TERM MODELS ARE IN MODERATE DISAGREEMENT WITH INITIATION OF CONVECTION ALONG A PASSING COLD FRONT...CURRENTLY DRAPED FROM NEAR NORFOLK...ACROSS GRAND ISLAND...SOUTH WESTWARD TOWARDS HOLDREGE. THIS FRONT HAS BEEN VERY SLOW TO WORK ITS WAY ACROSS THE FORECAST AREA THIS AFTERNOON...AND SO FAR HAS YET TO PRODUCE ENOUGH FORCING TO BREAK LOW LEVEL CAP. 12Z NAM AND WRF BOTH DID TRY AND INITIATE CONVECTION...BUT 18Z NAM AND LATEST HRRR BOTH HOLD OFF ANY WIDESPREAD SHOWER OR THUNDERSTORM ACTIVITY TILL FORCING FROM MID LEVEL LOW TO OUR WEST APPROACHES CENTRAL NEBRASKA AROUND MIDNIGHT. THAT BEING SAID...INGREDIENTS ARE IN PLACE...AS LATEST MESO ANALYSIS SHOWS A FINGER OF 2000+ J/KG OF CAPE ACROSS THE LOCAL AREA NEAR THE SLOWLY PROGRESSING FRONT...AND LITTLE INHIBITION AS WELL AS DEVELOPING CU FIELD IN SATELLITE. PER CONSENSUS AMONG MODELS...DID BACK OFF ON INITIATION OF CONVECTION THIS AFTERNOON...BUT INSERTED MENTION OF SEVERE STORMS AFTER 00Z...AS COMBINATION OF SHEAR AND INSTABILITY SHOULD BE SUFFICIENT FOR SOME SUPERCELLS TO DEVELOP IF INITIATION CAN BE REALIZED NEAR THE FRONT. BEHIND THE FRONT...AS THE MID LEVEL SHORTWAVE APPROACHES THE REGION...BROADER SCALE FORCING SHOULD BE AMPLE ENOUGH TO DEVELOP WIDESPREAD CONVECTION ACROSS THE LOCAL AREA BY AROUND MIDNIGHT...CONTINUING INTO THE OVERNIGHT HOURS...SO THE POTENTIAL FOR SEVERE HAIL AND STRONG WINDS REMAIN A CONCERN. THEREAFTER...THE ATMOSPHERE SHOULD BEGIN TO STABILIZE BEHIND THE DEPARTING MID LEVEL WAVE...WITH A SMALL CHANCE FOR SHOWERS AND AN ISOLATED THUNDERSTORM CONTINUING INTO THE AFTERNOON HOURS WITH NEAR TO SLIGHTLY BELOW SEASONAL TEMPERATURES EXPECTED DURING THE AFTERNOON. .LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY. MAIN FORECAST CONCERNS WILL BE CHANCES FOR THUNDERSTORMS THROUGH MOST OF THE PERIOD AND TEMPERATURES. ZONAL TO SOUTHWEST FLOW GIVES WAY TO NORTHWEST FLOW. THERE ARE SEVERAL WAVES THAT MOVE THROUGH THE AREA DURING THE PERIOD. THE FIRST WAVE MOVES INTO THE AREA THURSDAY NIGHT INTO FRIDAY. THERE WILL BE A CHANCE FOR SOME THUNDERSTORMS. ON FRIDAY A SURFACE LOW DEVELOPING IN KANSAS WILL LIFT A WARM FRONT NORTH INTO THE FORECAST AREA. WITH THE FRONT MOVING THROUGH AND THE ANOTHER UPPER WAVE MOVING INTO THE AREA THERE IS A BETTER CHANCE FOR THUNDERSTORMS. SOME OF THESE STORMS COULD BE STRONG TO SEVERE. SATURDAY AND SATURDAY NIGHT THERE ARE WEAK WAVES THAT MOVES THROUGH BUT LITTLE IN THE WAY TO GET THINGS STARTED SO ANY PRECIPITATION WILL BE SPOTTY. THE NEXT CHANCE FOR SOME THUNDERSTORMS WILL BE SUNDAY INTO SUNDAY NIGHT. ANOTHER STRONGER WAVE MOVES INTO THE AREA AND A COLD FRONT MOVES THROUGH THE AREA SUNDAY AFTERNOON AND EVENING. THUNDERSTORMS WILL DEVELOP ALONG THE FRONT AS IT MOVES THROUGH. SOME OF THESE COULD BE SEVERE. MONDAY AND MONDAY NIGHT THE UPPER WAVE MOVES TO THE EAST AND A SURFACE HIGH PRESSURE MOVES INTO THE AREA...KEEPING THINGS DRY. AGAIN TUESDAY INTO TUESDAY NIGHT THERE ARE A FEW WEAK UPPER LEVEL WAVES THAT MOVE INTO THE PLAINS. MODELS HAVE SOME FAIRLY SPOTTY PRECIPITATION AROUND THE AREA WITH THESE UPPER LEVEL WAVES. THE GFS HAS MORE PRECIPITATION AROUND THAN THE ECMWF DOES. TEMPERATURES WILL BE SOMEWHAT VARIABLE THROUGH THE WEEK. WITH CLOUDS AROUND ON FRIDAY THE TEMPERATURES WILL BE A BIT COOLER...WARMING AFTER THE WARM FRONT LIFTS TO THE NORTH FOR SATURDAY AND SUNDAY THEN COOLING AGAIN AS THE COOL FRONT MOVE THROUGH MONDAY AND TUESDAY AND COOLING MORE AFTER THE FRONT MOVES THROUGH TUESDAY. && .PREV DISCUSSION... /ISSUED 106 PM CDT WED MAY 23 2012/ AVIATION...18Z KGRI TAF...GUSTY SOUTHERLY WINDS AND VFR CONDITIONS WILL CONTINUE AT KGRI FOR THE NEXT FEW HOURS AS A COLD FRONT APPROACHES THE TERMINAL FROM THE NORTHWEST. THIS FRONT IS MAKING VERY SLOW PROGRESS TOWARDS THE SOUTHEAST...PRESENTLY STRETCHING FROM NEAR ORD TO LEXINGTON. WITH THE SLOW PROGRESSION OF THIS FRONT...HELD OFF ON A WIND SHIFT AT THE TERMINAL UNTIL 23/21Z...WITH GUSTY NORTHERLY WINDS AND A FEW SHOWERS EXPECTED THEREAFTER. AFT 24/00Z...EXPECT CIGS BEGIN TO LOWER TO NEAR MVFR LEVELS...WITH AN INCREASING CHANCE FOR -SHRAS AND -TSRAS. BEST FORCING FOR MORE PERSISTENT SHOWER AND THUNDERSTORM ACTIVITY IS AROUND MIDNIGHT TONIGHT...AND INTRODUCED A TEMPO GROUP AROUND THIS PERIOD FOR MORE PREVALENT MVFR CIGS AND VSBYS...BUT THAT SAID...EXPECT AT LEAST SOME SHRAS AND TSRAS IN THE VICINITY OF THE TERMINAL...SOME OF WHICH COULD CONTAIN LARGE HAIL AND SEVERE WIND GUSTS...TO BE PRESENT FROM THE EVENING HOURS TONIGHT THROUGH THE MORNING HOURS THURSDAY. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM/AVIATION...ROSSI LONG TERM...JCB
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
402 PM EDT WED MAY 23 2012 .SYNOPSIS... OUTSIDE A STRAY AFTERNOON OR EARLY EVENING SHOWER OR STORM...MAINLY DRY WEATHER IS EXPECTED THROUGH THURSDAY WITH WARM TEMPERATURES AND MODEST HUMIDITY LEVELS. A WEAKENING COLD FRONT WILL PUSH THROUGH THE AREA FRIDAY NIGHT INTO SATURDAY THOUGH AGAIN SHOWERY PRECIPITATION WILL BE SCATTERED AT BEST. WARM TEMPERATURES CONTINUE INTO NEXT WEEK WITH MORE ACTIVE WEATHER POSSIBLE AS SHOWERS AND THUNDERSTORMS WILL BE MORE COMMON. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 115 PM EDT WEDNESDAY...UPDATED TO CAPTURE LATEST CLOUD TRENDS WITH SOME CLRING ACRS THE SLV AND PARTS OF THE CPV/CENTRAL VT. ALSO...CONT WITH THE MENTION OF CHC POPS AND SCHC OF THUNDER ACRS SOUTHERN VT ZNS THIS AFTN...AS RADAR SHOWS A FEW ISOLATED RETURNS. WITH TEMPS IN THE MID 70S AND DWPTS NEAR 60F...SOME INSTABILITY HAS DEVELOPED WITH SFC BASED CAPE VALUES NEAR 1000 J/KG ACRS SOUTHERN VT ZNS...SUPPORTING A SCHC FOR A RUMBLE OF THUNDER. REST OF FCST IN GOOD SHAPE WITH HIGHS EXPECTED TO BE IN THE U60S TO M70S. SEVERAL MINOR UPDATES TO CRNT FCST...BASED ON VIS SATL PICS AND CRNT OBS. VIS SATL PIC SHOWS SOME BREAKS ACRS THE HIGHER ELEVATIONS OF THE DACKS AND SOME CLRING ACRS THE SLV. SOUNDINGS SHOW SOLID RH PROFILES THRU 18Z...THEN SOME CLRING. WL USE VIS SALT TOOL IN GFE TO CAPTURE CRNT TRENDS...THEN TAPER OVERALL AREAL COVERAGE OF CLOUDS AFT 18Z THIS AFTN...BASED ON SOUNDING RH PROFILES. OTHERWISE...HAVE DECREASED HRLY TEMPS THIS MORNING DUE TO CLOUDS...BUT FEEL AS BREAKS DEVELOP THIS AFTN...TEMPS WL CLIMB QUICKLY. REST OF FCST IN GREAT SHAPE. MODEST ADJUSTMENTS TO SKY COVER TO KEEP MOSTLY CLOUDY CONDS ACROSS MUCH OF THE AREA THROUGH THE MORNING HOURS BASED OFF CURRENT OBSERVATIONAL/SATELLITE TRENDS AND LATEST RAP 925MB RH PROGS. ALSO NUDGED MAX TEMPS DOWN JUST A TAD (1-2 DEG). REST OF FCST UNCHANGED. PRIOR DISCUSSION... WEAK AND DISSOLVING FRONTAL SYSTEM CONTINUES TO SAG EVER SO SLOWLY SOUTHWARD THROUGH THE FORECAST AREA THIS MORNING AS WINDS HAVE SHIFTED TO LIGHT NORTH/NORTHEASTERLY ACROSS OUR NRN COUNTIES AS OF 3 AM. STILL A FEW SHOWERS/PATCHY -DZ AROUND THE AREA WITH NEAR SATURATED LOWER LEVELS. OTHERWISE A RATHER UNEVENTFUL DAY ON TAP WEATHERWISE FOR THE REGION AS AFOREMENTIONED FRONTAL SYSTEM DISSIPATES TO OUR IMMEDIATE SOUTH ACROSS CENTRAL/SRN NEW ENGLAND. DESPITE LIGHT NORTHERLY FLOW...NO APPRECIABLE AIRMASS CHANGE EXPECTED AND MUCH DRIER AIR OFF TO OUR NORTH ACROSS SRN ON/QE REALLY WON`T MAKE APPRECIABLE INROADS INTO OUR AREA. VARIABLY CLOUDY SKIES AND PATCHY BR/FG THIS MORNING SHOULD SCOUR OUT TO PTLY SUNNY IN MANY AREAS THIS AFTERNOON AS PBL DEEPENS. STILL COULD SEE AN ISOLD LATE AFTERNOON/EARLY EVENING SHOWER/STORM FAR SOUTH IN CLOSER PROXIMITY TO OLD BOUNDARY AND DEEPER MOISTURE AXIS...BUT DRY WEATHER WILL BE THE GENERAL RULE. BLENDED 18-00Z MODEL 925 MB THERMAL PROGS SUPPORT BLENDED MOS LATE AFTERNOON HIGHS IN THE 72 TO 78 DEGREE RANGE. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... AS OF 344 AM EDT WEDNESDAY...THEN QUIET TONIGHT AS DEEP LAYER SFC TO H5 RIDGING BEGINS TO BUILD BACK ACROSS THE REGION. MAINLY CLR/PTLY CLOUDY SKIES EXPECTED...THOUGH AS FLOW TRENDS LIGHT SOUTH/SOUTHEASTERLY OVERNIGHT A DECENT CHANCE THAT SOME LOWER CLOUD COVER MAY BEGIN TO ENCROACH BACK NORTHWARD INTO OUR SRN/SERN VT COUNTIES AFTER MIDNIGHT. PATCHY FOG ALSO A GOOD BET AS WET GROUND CONDS FOSTER SATURATION IN THE NEAR-SFC LAYERS. LOWS SIMILAR TO THIS MORNING...MAINLY 50S TO LOCALLY NEAR 60 IN MILDER SPOTS OF THE CHAMPLAIN VALLEY. BY THURSDAY RIDGING WILL BECOME WELL ESTABLISHED ACROSS THE AREA AS SOUTHERLY FLOW SLOWLY INCREASES AND TRENDS MODESTLY GUSTY BY AFTERNOON. STILL AN OUTSIDE CHANCE OF A FEW SHOWERS/STRAY STORMS HERE AND THERE DURING PEAK HEATING HOURS SOUTH AS SFC INSOLATION ACTS ON RESIDUAL MOISTURE AXIS...OTHERWISE DRY AND PTLY SUNNY SHOULD BE THE RULE IN MOST LOCALES. TEMPERATURES A TAD WARMER INTO THE 77 TO 83 RANGE...CONTINUING RECENT STRING OF ABOVE NORMAL DAYS. THEN PTLY/MOSTLY CLOUDY AND MILD THURSDAY NIGHT AS TEMPERATURES HOLD IN THE UPPER 50S TO LOWER 60S. BY FRIDAY...GUSTY SOUTHERLY FLOW CONTINUES ACROSS THE AREA ALONG WITH A CONTINUED ISOLD THREAT OF A FEW SHOWERS/STORMS HERE AND THERE BY THE AFTERNOON/EARLY EVENING HOURS. BEST THREAT APPEARS TO OCCUR ACROSS THE SLV WHERE ADDED MOISTURE CONVERGENCE AND APPROACHING WEAK FRONTAL SYSTEM MAY AID IN SOMEWHAT HIGHER COVERAGE TOWARD EVENING. CONTINUED UNSEASONABLY WARM WITH HIGHS 78 TO 85 AND MODEST HUMIDITY LEVELS. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 401 PM EDT WEDNESDAY...HOLIDAY WEEKEND LOOKS TO BE FAIRLY QUIET AS FRONTAL BOUNDARY WILL BE STALLED OVER THE REGION SEPARATING HIGH PRESSURE TO OUR NORTH AND SOUTH. LOOKING AT GENERALLY DRY CONDITIONS UNDER PARTLY SUNNY SKIES WITH TEMPERATURES GENERALLY ABOVE NORMAL...HIGHS IN THE 70S AND LOWS IN THE UPPER 40S AND 50S. BOUNDARY BEGINS TO SHIFT NORTHWARD SUNDAY NIGHT INTO MONDAY WITH TEMPS WARMING INTO THE MID TO UPPER 70S MONDAY AFTERNOON...AND DEWPOINTS RISING INTO THE MID 50S. INDEED, BOTH THE ECMWF AND GFS INDICATE MODEST SHEAR AND INSTABILITY ALONG AND SOUTH OF THE BOUNDARY MONDAY AFTERNOON. TRICKY TO FORECAST BOUNDARY LOCATION OUT THIS FAR...BUT CERTAINLY COULD SEE SOME STORMS FIRE ALONG IT BASED ON MODEL INSTABILITY. LOW PRESSURE MOVING THROUGH SOUTHERN CANADA WILL PUSH THE AFOREMENTIONED BOUNDARY NORTH OF THE REGION PUTTING THE NORTH COUNTRY IN THE WARM SECTOR TUESDAY. ATTENDING COLD FRONT WILL MOVE ACROSS THE REGION TUESDAY AFTERNOON/EVENING RENEWING THE CHANCES FOR MORE SHOWERS AND THUNDERSTORMS. A LOT OF UNCERTAINTY GOING INTO TUESDAY NIGHT AND WEDNESDAY AS RELIABLE LONG TERM MODELS OF THE GFS AND ECMWF SHOW UPPER LEVEL TROUGH OVER SOUTH CENTRAL CANADA CLOSING OFF AND SLOWLY DROPPING SOUTHEASTWARD ACROSS THE REGION LATE IN THE WEEK. THIS WOULD PROVIDE THE AREA WITH MARKEDLY COOLER TEMPERATURES AND CHANCES FOR PRECIP...BUT CERTAINLY TOO FAR OUT TO NAIL DOWN ANY DETAILS AT THIS POINT. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... THROUGH 18Z THURSDAY...TRICKY AVIATION FORECAST OVER THE NEXT 24 HOURS. FIRST CHALLENGE IS TIMING CLEARING OF LOW LEVEL CLOUDS ACROSS THE REGION THIS AFTERNOON. MOST SITES BREAKING OUT INTO MVFR CATEGORY AS OF 1730Z...AND EXPECT A GENERALLY LIFTING TO VFR AT ALL SITES BY 21Z. THEREAFTER...CLEARING TREND CONTINUES THROUGH MIDNIGHT BEFORE MOISTURE BEGINS TO SURGE NORTHWARD AGAIN FROM THE SOUTH. LOW LEVEL MOISTURE WILL BE FAIRLY HIGH SHALLOW MUCH LIKE THIS MORNING...BUT MODEL GUIDANCE INDICATES BOUNDARY LAYER WINDS FROM THE SURFACE TO 1KFT WILL BE INCREASING THROUGH THE NIGHT. THINKING THERE WON`T BE A LOT OF FOG AROUND...BUT RATHER A LOW STRATUS DECK FORMING AT ALL SITES EXCEPT KMSS AFTER 06Z. HARD TO REALLY NAIL DOWN THE DETAILS AT THIS POINT SO STAY TUNED TO FURTHER TAF ISSUANCES. OTHERWISE...AFTER 13Z EXPECT ANY LOW CLOUDS TO LIFT TO CUMULUS AT OR ABOVE MOUNTAIN TOP LEVELS WITH WINDS PICKING UP OUT OF THE SOUTH. OUTLOOK 18Z THURSDAY THROUGH MONDAY... 18Z THURSDAY THROUGH 18Z FRIDAY...GENERALLY VFR UNDER RIDGE OF HIGH PRESSURE...WITH MORNING FOG/BR POSSIBLE. 18Z FRIDAY THROUGH SUNDAY...GENERALLY VFR WITH CHANCES FOR MVFR IN SCATTERED SHOWERS/TSTORMS AS FRONTAL BOUNDARY STALLS OVER THE REGION. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...JMG NEAR TERM...JMG/TABER SHORT TERM...JMG LONG TERM...LAHIFF AVIATION...LAHIFF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
138 PM EDT WED MAY 23 2012 .SYNOPSIS... OUTSIDE A STRAY AFTERNOON OR EARLY EVENING SHOWER OR STORM...MAINLY DRY WEATHER IS EXPECTED THROUGH THURSDAY WITH WARM TEMPERATURES AND MODEST HUMIDITY LEVELS. A WEAKENING COLD FRONT WILL PUSH THROUGH THE AREA FRIDAY NIGHT INTO SATURDAY THOUGH AGAIN SHOWERY PRECIPITATION WILL BE SCATTERED AT BEST. WARM TEMPERATURES CONTINUE INTO NEXT WEEK WITH MORE ACTIVE WEATHER POSSIBLE AS SHOWERS AND THUNDERSTORMS WILL BE MORE COMMON. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 115 PM EDT WEDNESDAY...UPDATED TO CAPTURE LATEST CLOUD TRENDS WITH SOME CLRING ACRS THE SLV AND PARTS OF THE CPV/CENTRAL VT. ALSO...CONT WITH THE MENTION OF CHC POPS AND SCHC OF THUNDER ACRS SOUTHERN VT ZNS THIS AFTN...AS RADAR SHOWS A FEW ISOLATED RETURNS. WITH TEMPS IN THE MID 70S AND DWPTS NEAR 60F...SOME INSTABILITY HAS DEVELOPED WITH SFC BASED CAPE VALUES NEAR 1000 J/KG ACRS SOUTHERN VT ZNS...SUPPORTING A SCHC FOR A RUMBLE OF THUNDER. REST OF FCST IN GOOD SHAPE WITH HIGHS EXPECTED TO BE IN THE U60S TO M70S. SEVERAL MINOR UPDATES TO CRNT FCST...BASED ON VIS SATL PICS AND CRNT OBS. VIS SATL PIC SHOWS SOME BREAKS ACRS THE HIGHER ELEVATIONS OF THE DACKS AND SOME CLRING ACRS THE SLV. SOUNDINGS SHOW SOLID RH PROFILES THRU 18Z...THEN SOME CLRING. WL USE VIS SALT TOOL IN GFE TO CAPTURE CRNT TRENDS...THEN TAPER OVERALL AREAL COVERAGE OF CLOUDS AFT 18Z THIS AFTN...BASED ON SOUNDING RH PROFILES. OTHERWISE...HAVE DECREASED HRLY TEMPS THIS MORNING DUE TO CLOUDS...BUT FEEL AS BREAKS DEVELOP THIS AFTN...TEMPS WL CLIMB QUICKLY. REST OF FCST IN GREAT SHAPE. MODEST ADJUSTMENTS TO SKY COVER TO KEEP MOSTLY CLOUDY CONDS ACROSS MUCH OF THE AREA THROUGH THE MORNING HOURS BASED OFF CURRENT OBSERVATIONAL/SATELLITE TRENDS AND LATEST RAP 925MB RH PROGS. ALSO NUDGED MAX TEMPS DOWN JUST A TAD (1-2 DEG). REST OF FCST UNCHANGED. PRIOR DISCUSSION... WEAK AND DISSOLVING FRONTAL SYSTEM CONTINUES TO SAG EVER SO SLOWLY SOUTHWARD THROUGH THE FORECAST AREA THIS MORNING AS WINDS HAVE SHIFTED TO LIGHT NORTH/NORTHEASTERLY ACROSS OUR NRN COUNTIES AS OF 3 AM. STILL A FEW SHOWERS/PATCHY -DZ AROUND THE AREA WITH NEAR SATURATED LOWER LEVELS. OTHERWISE A RATHER UNEVENTFUL DAY ON TAP WEATHERWISE FOR THE REGION AS AFOREMENTIONED FRONTAL SYSTEM DISSIPATES TO OUR IMMEDIATE SOUTH ACROSS CENTRAL/SRN NEW ENGLAND. DESPITE LIGHT NORTHERLY FLOW...NO APPRECIABLE AIRMASS CHANGE EXPECTED AND MUCH DRIER AIR OFF TO OUR NORTH ACROSS SRN ON/QE REALLY WON`T MAKE APPRECIABLE INROADS INTO OUR AREA. VARIABLY CLOUDY SKIES AND PATCHY BR/FG THIS MORNING SHOULD SCOUR OUT TO PTLY SUNNY IN MANY AREAS THIS AFTERNOON AS PBL DEEPENS. STILL COULD SEE AN ISOLD LATE AFTERNOON/EARLY EVENING SHOWER/STORM FAR SOUTH IN CLOSER PROXIMITY TO OLD BOUNDARY AND DEEPER MOISTURE AXIS...BUT DRY WEATHER WILL BE THE GENERAL RULE. BLENDED 18-00Z MODEL 925 MB THERMAL PROGS SUPPORT BLENDED MOS LATE AFTERNOON HIGHS IN THE 72 TO 78 DEGREE RANGE. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... AS OF 344 AM EDT WEDNESDAY...THEN QUIET TONIGHT AS DEEP LAYER SFC TO H5 RIDGING BEGINS TO BUILD BACK ACROSS THE REGION. MAINLY CLR/PTLY CLOUDY SKIES EXPECTED...THOUGH AS FLOW TRENDS LIGHT SOUTH/SOUTHEASTERLY OVERNIGHT A DECENT CHANCE THAT SOME LOWER CLOUD COVER MAY BEGIN TO ENCROACH BACK NORTHWARD INTO OUR SRN/SERN VT COUNTIES AFTER MIDNIGHT. PATCHY FOG ALSO A GOOD BET AS WET GROUND CONDS FOSTER SATURATION IN THE NEAR-SFC LAYERS. LOWS SIMILAR TO THIS MORNING...MAINLY 50S TO LOCALLY NEAR 60 IN MILDER SPOTS OF THE CHAMPLAIN VALLEY. BY THURSDAY RIDGING WILL BECOME WELL ESTABLISHED ACROSS THE AREA AS SOUTHERLY FLOW SLOWLY INCREASES AND TRENDS MODESTLY GUSTY BY AFTERNOON. STILL AN OUTSIDE CHANCE OF A FEW SHOWERS/STRAY STORMS HERE AND THERE DURING PEAK HEATING HOURS SOUTH AS SFC INSOLATION ACTS ON RESIDUAL MOISTURE AXIS...OTHERWISE DRY AND PTLY SUNNY SHOULD BE THE RULE IN MOST LOCALES. TEMPERATURES A TAD WARMER INTO THE 77 TO 83 RANGE...CONTINUING RECENT STRING OF ABOVE NORMAL DAYS. THEN PTLY/MOSTLY CLOUDY AND MILD THURSDAY NIGHT AS TEMPERATURES HOLD IN THE UPPER 50S TO LOWER 60S. BY FRIDAY...GUSTY SOUTHERLY FLOW CONTINUES ACROSS THE AREA ALONG WITH A CONTINUED ISOLD THREAT OF A FEW SHOWERS/STORMS HERE AND THERE BY THE AFTERNOON/EARLY EVENING HOURS. BEST THREAT APPEARS TO OCCUR ACROSS THE SLV WHERE ADDED MOISTURE CONVERGENCE AND APPROACHING WEAK FRONTAL SYSTEM MAY AID IN SOMEWHAT HIGHER COVERAGE TOWARD EVENING. CONTINUED UNSEASONABLY WARM WITH HIGHS 78 TO 85 AND MODEST HUMIDITY LEVELS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 445 AM EDT WEDNESDAY...THE PERIOD WILL START WITH A COLD FRONT TRAVERSING OVER THE FCST AREA. 00Z GFS AND ECMWF DIFFER ON TIMING OF FRONTAL PASSAGE...BUT BOTH MODELS SHOW FRONT LINGERING ALONG THE ATLANTIC COAST BY SATURDAY NIGHT. HIGH PRESSURE WILL THEN BUILD IN AT THE SFC FROM SOUTHERN QUEBEC...GIVING A SHORT DRY PERIOD ON SATURDAY INTO EARLY SUNDAY. LATE SUNDAY...MODEL GUIDANCE INDICATES AN UPPER LEVEL DISTURBANCE/WEAK SHORT WAVE WILL MOVE OVER THE REGION...WITH AN UPPER LEVEL JET TO OUR NORTH. INCREASED INSTABILITY LATE SUNDAY INTO MONDAY WITH GFS INDICATING CAPE VALUES OVER 1000J/KG AND NEGATIVE LIFTED INDICES. ECMWF KEEPS THE HIGH CAPE VALUE TO OUR SOUTH. THE AFOREMENTIONED COLD FRONT WILL LIFT NORTHWARD AS A WARM FRONT AS LOW PRESSURE CENTER AT THE SFC MOVES FROM THE NWRN GREAT LAKES TO SE ONTARIO MONDAY AND TUESDAY. THIS WILL CONTINUE TO PRODUCE CHANCE OF SHOWERS. TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL...WITH A SLGT COOLING TREND TO START. 850HPA TEMPS WILL COOL FROM THE MID TEENS TO 10C-12C SUNDAY. ECMWF HAS FRONT SYSTEM BEING STRONGER THAN GFS AND BRINGS SINGLE DIGIT TEMPS AT 850HPA BY MONDAY MORNING. BOTH MODELS DO SHOW DECENT TEMP GRADIENT OVER THE NORTHEAST WHICH WILL HELP WITH POTENTIAL FOR CONVECTIVE ACTIVITY. BOTH MODELS WARM TEMPS ON MONDAY TO MID TO UPPER TEENS AT 850HPA...BUT GRADUALLY COOLING ON TUESDAY. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... THROUGH 18Z THURSDAY...TRICKY AVIATION FORECAST OVER THE NEXT 24 HOURS. FIRST CHALLENGE IS TIMING CLEARING OF LOW LEVEL CLOUDS ACROSS THE REGION THIS AFTERNOON. MOST SITES BREAKING OUT INTO MVFR CATEGORY AS OF 1730Z...AND EXPECT A GENERALLY LIFTING TO VFR AT ALL SITES BY 21Z. THEREAFTER...CLEARING TREND CONTINUES THROUGH MIDNIGHT BEFORE MOISTURE BEGINS TO SURGE NORTHWARD AGAIN FROM THE SOUTH. LOW LEVEL MOISTURE WILL BE FAIRLY HIGH SHALLOW MUCH LIKE THIS MORNING...BUT MODEL GUIDANCE INDICATES BOUNDARY LAYER WINDS FROM THE SURFACE TO 1KFT WILL BE INCREASING THROUGH THE NIGHT. THINKING THERE WON`T BE A LOT OF FOG AROUND...BUT RATHER A LOW STRATUS DECK FORMING AT ALL SITES EXCEPT KMSS AFTER 06Z. HARD TO REALLY NAIL DOWN THE DETAILS AT THIS POINT SO STAY TUNED TO FURTHER TAF ISSUANCES. OTHERWISE...AFTER 13Z EXPECT ANY LOW CLOUDS TO LIFT TO CUMULUS AT OR ABOVE MOUNTAIN TOP LEVELS WITH WINDS PICKING UP OUT OF THE SOUTH. OUTLOOK 18Z THURSDAY THROUGH MONDAY... 18Z THURSDAY THROUGH 18Z FRIDAY...GENERALLY VFR UNDER RIDGE OF HIGH PRESSURE...WITH MORNING FOG/BR POSSIBLE. 18Z FRIDAY THROUGH SUNDAY...GENERALLY VFR WITH CHANCES FOR MVFR IN SCATTERED SHOWERS/TSTORMS AS FRONTAL BOUNDARY STALLS OVER THE REGION. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...JMG NEAR TERM...JMG/TABER SHORT TERM...JMG LONG TERM...KGM AVIATION...LAHIFF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
122 PM EDT WED MAY 23 2012 .SYNOPSIS... OUTSIDE A STRAY AFTERNOON OR EARLY EVENING SHOWER OR STORM...MAINLY DRY WEATHER IS EXPECTED THROUGH THURSDAY WITH WARM TEMPERATURES AND MODEST HUMIDITY LEVELS. A WEAKENING COLD FRONT WILL PUSH THROUGH THE AREA FRIDAY NIGHT INTO SATURDAY THOUGH AGAIN SHOWERY PRECIPITATION WILL BE SCATTERED AT BEST. WARM TEMPERATURES CONTINUE INTO NEXT WEEK WITH MORE ACTIVE WEATHER POSSIBLE AS SHOWERS AND THUNDERSTORMS WILL BE MORE COMMON. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 115 PM EDT WEDNESDAY...UPDATED TO CAPTURE LATEST CLOUD TRENDS WITH SOME CLRING ACRS THE SLV AND PARTS OF THE CPV/CENTRAL VT. ALSO...CONT WITH THE MENTION OF CHC POPS AND SCHC OF THUNDER ACRS SOUTHERN VT ZNS THIS AFTN...AS RADAR SHOWS A FEW ISOLATED RETURNS. WITH TEMPS IN THE MID 70S AND DWPTS NEAR 60F...SOME INSTABILITY HAS DEVELOPED WITH SFC BASED CAPE VALUES NEAR 1000 J/KG ACRS SOUTHERN VT ZNS...SUPPORTING A SCHC FOR A RUMBLE OF THUNDER. REST OF FCST IN GOOD SHAPE WITH HIGHS EXPECTED TO BE IN THE U60S TO M70S. SEVERAL MINOR UPDATES TO CRNT FCST...BASED ON VIS SATL PICS AND CRNT OBS. VIS SATL PIC SHOWS SOME BREAKS ACRS THE HIGHER ELEVATIONS OF THE DACKS AND SOME CLRING ACRS THE SLV. SOUNDINGS SHOW SOLID RH PROFILES THRU 18Z...THEN SOME CLRING. WL USE VIS SALT TOOL IN GFE TO CAPTURE CRNT TRENDS...THEN TAPER OVERALL AREAL COVERAGE OF CLOUDS AFT 18Z THIS AFTN...BASED ON SOUNDING RH PROFILES. OTHERWISE...HAVE DECREASED HRLY TEMPS THIS MORNING DUE TO CLOUDS...BUT FEEL AS BREAKS DEVELOP THIS AFTN...TEMPS WL CLIMB QUICKLY. REST OF FCST IN GREAT SHAPE. MODEST ADJUSTMENTS TO SKY COVER TO KEEP MOSTLY CLOUDY CONDS ACROSS MUCH OF THE AREA THROUGH THE MORNING HOURS BASED OFF CURRENT OBSERVATIONAL/SATELLITE TRENDS AND LATEST RAP 925MB RH PROGS. ALSO NUDGED MAX TEMPS DOWN JUST A TAD (1-2 DEG). REST OF FCST UNCHANGED. PRIOR DISCUSSION... WEAK AND DISSOLVING FRONTAL SYSTEM CONTINUES TO SAG EVER SO SLOWLY SOUTHWARD THROUGH THE FORECAST AREA THIS MORNING AS WINDS HAVE SHIFTED TO LIGHT NORTH/NORTHEASTERLY ACROSS OUR NRN COUNTIES AS OF 3 AM. STILL A FEW SHOWERS/PATCHY -DZ AROUND THE AREA WITH NEAR SATURATED LOWER LEVELS. OTHERWISE A RATHER UNEVENTFUL DAY ON TAP WEATHERWISE FOR THE REGION AS AFOREMENTIONED FRONTAL SYSTEM DISSIPATES TO OUR IMMEDIATE SOUTH ACROSS CENTRAL/SRN NEW ENGLAND. DESPITE LIGHT NORTHERLY FLOW...NO APPRECIABLE AIRMASS CHANGE EXPECTED AND MUCH DRIER AIR OFF TO OUR NORTH ACROSS SRN ON/QE REALLY WON`T MAKE APPRECIABLE INROADS INTO OUR AREA. VARIABLY CLOUDY SKIES AND PATCHY BR/FG THIS MORNING SHOULD SCOUR OUT TO PTLY SUNNY IN MANY AREAS THIS AFTERNOON AS PBL DEEPENS. STILL COULD SEE AN ISOLD LATE AFTERNOON/EARLY EVENING SHOWER/STORM FAR SOUTH IN CLOSER PROXIMITY TO OLD BOUNDARY AND DEEPER MOISTURE AXIS...BUT DRY WEATHER WILL BE THE GENERAL RULE. BLENDED 18-00Z MODEL 925 MB THERMAL PROGS SUPPORT BLENDED MOS LATE AFTERNOON HIGHS IN THE 72 TO 78 DEGREE RANGE. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... AS OF 344 AM EDT WEDNESDAY...THEN QUIET TONIGHT AS DEEP LAYER SFC TO H5 RIDGING BEGINS TO BUILD BACK ACROSS THE REGION. MAINLY CLR/PTLY CLOUDY SKIES EXPECTED...THOUGH AS FLOW TRENDS LIGHT SOUTH/SOUTHEASTERLY OVERNIGHT A DECENT CHANCE THAT SOME LOWER CLOUD COVER MAY BEGIN TO ENCROACH BACK NORTHWARD INTO OUR SRN/SERN VT COUNTIES AFTER MIDNIGHT. PATCHY FOG ALSO A GOOD BET AS WET GROUND CONDS FOSTER SATURATION IN THE NEAR-SFC LAYERS. LOWS SIMILAR TO THIS MORNING...MAINLY 50S TO LOCALLY NEAR 60 IN MILDER SPOTS OF THE CHAMPLAIN VALLEY. BY THURSDAY RIDGING WILL BECOME WELL ESTABLISHED ACROSS THE AREA AS SOUTHERLY FLOW SLOWLY INCREASES AND TRENDS MODESTLY GUSTY BY AFTERNOON. STILL AN OUTSIDE CHANCE OF A FEW SHOWERS/STRAY STORMS HERE AND THERE DURING PEAK HEATING HOURS SOUTH AS SFC INSOLATION ACTS ON RESIDUAL MOISTURE AXIS...OTHERWISE DRY AND PTLY SUNNY SHOULD BE THE RULE IN MOST LOCALES. TEMPERATURES A TAD WARMER INTO THE 77 TO 83 RANGE...CONTINUING RECENT STRING OF ABOVE NORMAL DAYS. THEN PTLY/MOSTLY CLOUDY AND MILD THURSDAY NIGHT AS TEMPERATURES HOLD IN THE UPPER 50S TO LOWER 60S. BY FRIDAY...GUSTY SOUTHERLY FLOW CONTINUES ACROSS THE AREA ALONG WITH A CONTINUED ISOLD THREAT OF A FEW SHOWERS/STORMS HERE AND THERE BY THE AFTERNOON/EARLY EVENING HOURS. BEST THREAT APPEARS TO OCCUR ACROSS THE SLV WHERE ADDED MOISTURE CONVERGENCE AND APPROACHING WEAK FRONTAL SYSTEM MAY AID IN SOMEWHAT HIGHER COVERAGE TOWARD EVENING. CONTINUED UNSEASONABLY WARM WITH HIGHS 78 TO 85 AND MODEST HUMIDITY LEVELS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 445 AM EDT WEDNESDAY...THE PERIOD WILL START WITH A COLD FRONT TRAVERSING OVER THE FCST AREA. 00Z GFS AND ECMWF DIFFER ON TIMING OF FRONTAL PASSAGE...BUT BOTH MODELS SHOW FRONT LINGERING ALONG THE ATLANTIC COAST BY SATURDAY NIGHT. HIGH PRESSURE WILL THEN BUILD IN AT THE SFC FROM SOUTHERN QUEBEC...GIVING A SHORT DRY PERIOD ON SATURDAY INTO EARLY SUNDAY. LATE SUNDAY...MODEL GUIDANCE INDICATES AN UPPER LEVEL DISTURBANCE/WEAK SHORT WAVE WILL MOVE OVER THE REGION...WITH AN UPPER LEVEL JET TO OUR NORTH. INCREASED INSTABILITY LATE SUNDAY INTO MONDAY WITH GFS INDICATING CAPE VALUES OVER 1000J/KG AND NEGATIVE LIFTED INDICES. ECMWF KEEPS THE HIGH CAPE VALUE TO OUR SOUTH. THE AFOREMENTIONED COLD FRONT WILL LIFT NORTHWARD AS A WARM FRONT AS LOW PRESSURE CENTER AT THE SFC MOVES FROM THE NWRN GREAT LAKES TO SE ONTARIO MONDAY AND TUESDAY. THIS WILL CONTINUE TO PRODUCE CHANCE OF SHOWERS. TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL...WITH A SLGT COOLING TREND TO START. 850HPA TEMPS WILL COOL FROM THE MID TEENS TO 10C-12C SUNDAY. ECWMF HAS FRONT SYSTEM BEING STRONGER THAN GFS AND BRINGS SINGLE DIGIT TEMPS AT 850HPA BY MONDAY MORNING. BOTH MODELS DO SHOW DECENT TEMP GRADIENT OVER THE NORTHEAST WHICH WILL HELP WITH POTENTIAL FOR CONVECTIVE ACTIVITY. BOTH MODELS WARM TEMPS ON MONDAY TO MID TO UPPER TEENS AT 850HPA...BUT GRADUALLY COOLING ON TUESDAY. && .AVIATION /17Z WEDNESDAY THROUGH SUNDAY/... THROUGH 12Z THURSDAY...CLOUDS WILL GRADUALLY DISSIPATE THIS MORNING...WITH IMPROVING VSBYS. OVERALL FLIGHT CONDITIONS WILL IMPROVE TO MVFR BY LATE MORNING...15Z AT KBTV/KPBG/RUT/ CONDITIONS WILL CONTINUE TO IMPROVE TO VFR BY LATE MORNING/EARLY AFTERNOON AT ALL TERMINALS. CLOUDS WILL GENERALLY BECOME SCT TO BKN MID AND HIGH LEVEL FOR THE AFTERNOON AND EVENING. OVERNIGHT...MOISTURE WILL SURGE NORTHWARD INTO THE AREA...ALLOWING FOR MVFR CONDITIONS TO DEVELOP AROUND 05Z-06Z THROUGH THURSDAY MORNING. OUTLOOK 12Z THURSDAY THROUGH SUNDAY... 12Z THURSDAY THROUGH 18Z FRIDAY...GENERALLY VFR UNDER RIDGE OF HIGH PRESSURE...ALTHOUGH SOME FOG/BR POSSIBLE THURSDAY MORNING. 18Z FRIDAY THROUGH SUNDAY...GENERALLY VFR BUT BRIEF PERIODS OF MVFR POSSIBLE IN SCATTERED SHOWERS/TSTORMS. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...JMG NEAR TERM...JMG/TABER SHORT TERM...JMG LONG TERM...KGM AVIATION...KGM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
406 PM CDT WED MAY 23 2012 .SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT... FORECAST CONCERNS THROUGH THURSDAY NIGHT ARE MAINLY FOCUSED AROUND SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS EVENING ACROSS THE WEST...FOLLOWED BY AND CHANCES OF ADDITIONAL PRECIPITATION THURSDAY INTO THURSDAY NIGHT. POTENTIAL FOR FROST THURSDAY NIGHT IN THE WEST...BUT CLOUD COVER MAY INHIBIT WIDESPREAD FROST. NO SEVERE WEATHER IS EXPECTED THROUGH THURSDAY NIGHT. LATEST VISIBLE SATELLITE IMAGERY SHOWS AN INCREASING CUMULUS FIELD OVER NORTHWEST AND NORTH CENTRAL NORTH DAKOTA. PER SPC MESOSCALE ANALYSIS...STEEP LOW LEVEL LAPSE RATES AND MODERATE MID LEVEL LAPSE RATES CONTINUE UNDERNEATH AN UPPER LOW SEEN CIRCULATING ACROSS SOUTHERN SASKATCHEWAN. A COLD FRONT WAS ALSO NOTED ACROSS SOUTHERN ALBERTA INTO SOUTHERN SASKATCHEWAN THIS AFTERNOON. THE 12Z 4KM WRF INDICATES ISOLATED TO SCATTERED SHOWERS ALONG WITH ISOLATED THUNDERSTORMS ACROSS THE WEST THROUGH SUNSET AND CONCUR WITH THIS IDEA. CURRENT UPSTREAM RADAR SUPPORTS THIS. RAP SOUNDINGS PER BUFKIT ADVERTISE CAPE VALUES RANGING BETWEEN 200 TO 400 J/KG AT KISN/KMOT/KDIK. TQ INDICES OF 16C ALSO SUGGEST LOW TOP CONVECTION POSSIBLE THUS WILL CONTINUE WITH ISOLATED MENTION OF THUNDERSTORMS. WITH A LACK OF SHEAR...EXPECT PULSE TYPE THUNDERSTORMS WITH PERHAPS PEA SIZED HAIL POSSIBLE. ACTIVITY WILL WANE WITH SUNSET...ENDING BY 03Z THURSDAY. ALSO NOTED WAS A SHORTWAVE SLIDING THROUGH EASTERN WYOMING THIS AFTERNOON. LOCAL AND REGIONAL RADAR ALSO SHOW ECHOES OVER WESTERN AND CENTRAL SOUTH DAKOTA REACHING INTO FAR SOUTH CENTRAL NORTH DAKOTA. THIS APPEARS TO BE MAINLY ALOFT AS REPORTING STATIONS ARE SHOWING SCT TO BKN MID LEVEL CLOUDS. HOWEVER WILL MAINTAIN ISOLATED RAIN SHOWERS THROUGH 00Z THURSDAY TO COVER SHOWERS THAT MAY REACH THE GROUND. THE THUNDERSTORM THREAT SHOULD REMAIN IN EASTERN SOUTH DAKOTA INTO WESTERN MINNESOTA. THE AFOREMENTIONED COLD FRONT WILL SAG SOUTHEAST TONIGHT WITH LOW LEVEL COLD AIR ADVECTION COMMENCING ALL THE WAY THROUGH FRIDAY MORNING. THIS WILL RESULT IN COOLER TEMPERATURES THROUGH THE PERIOD. H85 TEMPS BETWEEN 0C AND -2C BECOME DOMINANT THURSDAY NIGHT OVER NORTHERN AND WESTERN NORTH DAKOTA. SOME LOW LEVEL MOISTURE/CLOUD COVER PER NAM 925MB RH FIELD MAY INHIBIT WIDESPREAD LOW TEMPERATURES IN THE MID 30S. WILL CONTINUE TO MONITOR AND PASS THIS ALONG TO FUTURE SHIFTS THAT A FROST ADVISORY MAY BE WARRANTED LATE THURSDAY NIGHT INTO EARLY FRIDAY MORNING IN THE WEST AND NORTH. WITH REGARDS TO PRECIPITATION...THE UPPER LOW SLOWLY MOVES FROM SOUTHEASTERN SASKATCHEWAN TONIGHT INTO NORTHERN MINNESOTA BY FRIDAY MORNING. MAIN IMPACT WOULD BE CHANCES OF SHOWERS OR THUNDERSTORMS DURING PEAK HEATING WITH COLD AIR ALOFT AND DECENT LOW/MID LEVEL LAPSE RATES. MODELS ARE IN GOOD AGREEMENT WITH MINIMAL ACTIVITY THURSDAY...KEEPING THE PRECIPITATION CONFINED TO FAR WESTERN AND FAR SOUTHERN NORTH DAKOTA THURSDAY INTO THURSDAY NIGHT. .LONG TERM...FRIDAY THROUGH WEDNESDAY... THE MAIN FOCUS THIS FORECAST PERIOD IS ON THE WIDESPREAD PRECIPITATION EVENT FORECAST TO IMPACT NORTH DAKOTA FRIDAY NIGHT THROUGH SUNDAY MORNING. WATER VAPOR SATELLITE IMAGERY DEPICTS A MIDDLE/UPPER LEVEL LOW OVER THE ALASKA PANHANDLE...WHICH IS FORECAST TO DIVE INTO THE WESTERN U.S. AND EJECT A SERIES OF MIDDLE LEVEL SHORTWAVES INTO THE DAKOTAS. STRONG LEE CYCLOGENESIS SHOULD SUPPORT FAVORABLE MOISTURE TRANSPORT TO FUEL MODERATE TO HEAVY RAIN ACROSS THE NORTHERN HIGH PLAINS. WHILE MONTANA IS MOST FAVORED FOR AMOUNTS GREATER THAN AN INCH...STRONG AGEOSTROPHIC CIRCULATIONS JUSTIFY INCREASING PRECIPITATION CHANCES OVER MUCH OF THE 12 UTC MOS GUIDANCE. THE LOCATION OF 12 UTC ECMWF/GFS/GEFS MEAN/GEM GLOBAL H5 AND SURFACE LOWS FAVORS AREAS WELL EAST OF THE JAMES RIVER VALLEY FOR STRONG TO SEVERE THUNDERSTORMS ON SATURDAY...BUT THE RECENT TREND AMONG MODELS IS TO PULL THE H5 LOW A BIT FURTHER WEST. THIS WILL NEED TO BE MONITORED...ESPECIALLY FOR SOUTHEASTERN NORTH DAKOTA COUNTIES. UNFORTUNATELY...THE WELCOME RAIN ACROSS MUCH OF THE STATE WILL ARRIVE WITH TEMPERATURES LARGELY IN THE 40S. TEMPERATURES SHOULD REMAIN BELOW AVERAGE THROUGH THE PERIOD. && .AVIATION... A FEW RAIN SHOWERS ARE POSSIBLE AT KISN AND KMOT. WIND DIRECTION HAS BEEN A PROBLEM TODAY AS A COMPACT SURFACE TROUGH IS CAUSING WIND TO SHIFT BETWEEN 240 AND 290. MVFR CLOUDS MAY SAG INTO KISN AND KMOT EARLY THURSDAY MORNING ON THE WEST SIDE OF CANADIAN LOW PRESSURE. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KS LONG TERM/AVIATION...SCHECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1245 PM CDT WED MAY 23 2012 .SHORT TERM... 1101 AM CDT WED MAY 23 2012 LATEST 16Z METARS INDICATE WINDS HAVE INCREASED TO 15 TO 25 KNOTS AND GUST UP TO 33 KNOTS ACROSS PARTS OF SOUTHEAST MINNESOTA AND NORTHEAST IOWA. LATEST 23.14Z RAP BUFKIT SOUNDINGS INDICATE WINDS WILL MIX DOWN FROM ALOFT AND A TIGHT PRESSURE GRADIENT OUT AHEAD OF A COLD FRONT WILL ALLOW WINDS TO INCREASE TO 20 TO 30 MPH WITH GUST UP TO 45 MPH LATE THIS MORNING AND AFTERNOON OVER PORTIONS OF SOUTHEAST MINNESOTA AND NORTHEAST IOWA. THEREFORE...HAVE ISSUED A WIND ADVISORY FOR PARTS OF SOUTHEAST MINNESOTA AND NORTHEAST IOWA. .LONG TERM...SATURDAY THROUGH TUESDAY 344 AM CDT WED MAY 23 2012 MODEL CONSENSUS CONTINUES TO TIGHTEN/IMPROVE THROUGH THE HOLIDAY WEEKEND PERIOD...WITH SAT-TUE FCST CONFIDENCE NOW AVERAGE OR A BIT BETTER. PERSISTENT SOUTH FLOW AHEAD OF THE LEE TROUGH/LOW IN THE PLAINS PUSHES THE WARM FRONT NORTH ACROSS THE AREA SAT/SUN. THIS AS THE LEE LOW EVENTUALLY LIFTS INTO THE NORTHERN PLAINS AND THE MID LEVEL TROUGH SLOWLY EJECTS TOWARD THE NORTHERN PLAINS. CONVECTION EXPECTED TO BE ONGOING NORTH OF THE FRONTAL BOUNDARY SAT...SOMEWHERE ACROSS WI/SOUTHERN MN/NORTHERN IA. THIS CONVECTION HAS POTENTIAL TO STALL THE FRONT/S NORTHWARD PROGRESS ON SAT. ANY BREAKS IN CONVECTION SAT/SAT NIGHT SHOULD ALLOW THE FRONT TO LIFT NORTH OF THE FCST AREA BY OR ON SUNDAY. AGAIN BETTER MODEL SIGNAL FOR THIS TO OCCUR...WITH SUNDAY A VERY WARM/SUMMERY DAY WITH SMALL IF ANY RAIN CHANCES WITH A CAPPED...WARM SECTOR AIRMASS OVER THE AREA. MID LEVEL TROUGH LIFTING ACROSS THE NORTHERN PLAINS INTO SOUTH CAN MON/TUE SENDS A COLD FRONT ACROSS THE AREA ON MON. THIS INTO WHAT SHOULD BE A RATHER MOIST/UNSTABLE AIRMASS OVER THE REGION. SOME TIMING/STRENGTH DIFFERENCES BY MON...SHRA/TSRA CHANCES FROM SUN NIGHT THRU MON NIGHT VERY REASONABLE. MODEL/ENSEMBLE CONSENSUS DATA IN THE DAY 4-7 FCST GRIDS DEPICT THIS QUITE WELL WITH ONLY MINOR ADJUSTMENTS MADE TO BLEND WITH NEIGHBORING GRIDS. && .AVIATION...THROUGH 18Z THURSDAY 1244 PM CDT WED MAY 23 2012 A LOW PRESSURE SYSTEM OVER THE CENTRAL HIGH PLAINS WILL PUSH NORTHEAST INTO NORTHERN IOWA BY 18Z THURSDAY. OUT AHEAD OF THE LOW PRESSURE SYSTEM...THE COMBINATION OF WINDS MIXING DOWN ALOFT AND A TIGHTENING PRESSURE GRADIENT WILL CREATE WINDY CONDITIONS...ESPECIALLY WEST OF THE MISSISSIPPI RIVER. SOUTHERLY WINDS WILL BE SUSTAINED AT 25 KNOTS WITH GUSTS UP TO 38 KNOTS CAN AT RST AND LSE WILL BE SUSTAINED AT 18 KNOTS AND GUST UP TO 27 KNOTS THROUGH 02Z THURSDAY. NEXT CONCERN ARE PRECIPITATION CHANCES AT BOTH TAF SITES. LATEST 23.12Z DETERMINISTIC MODELS INDICATE BEST MOISTURE CONVERGENCE AND LIFT ASSOCIATED WITH LOW PRESSURE SYSTEM WILL BE WEST OF THE TAF SITES. HOWEVER...MODELS DO INDICATE THE POSSIBILITY OF SHOWERS AND PERHAPS A THUNDERSTORM TO MOVE INTO THE RST TAF SITE AFTER 05Z THURSDAY AND 10Z THURSDAY AT LSE. VFR CONDITIONS SHOULD PREVAIL AT BOTH TAF SITES THROUGH THE PERIOD. THE DETERMINISTIC MODELS DO SUGGEST IF A THUNDERSTORM OR STRONG SHOWER SHOULD DROP CEILINGS INTO THE MVFR/IFR RANGE. WITH CONFIDENCE LOW FOR THIS OCCURRING HAVE LEFT VFR CONDITIONS TO PREVAIL. LOW LEVEL WIND SHEAR IS POSSIBLE OVER THE TAF SITES AFTER 09Z THURSDAY...AT THIS TIME WILL LET LATER SHIFTS DIAGNOSE OF OCCURRING. && .ARX WATCHES/WARNINGS/ADVISORIES... 1101 AM CDT WED MAY 23 2012 WI...NONE. MN...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR MNZ086-087-094-095. IA...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR IAZ008-009-018-019. && $$ SHORT TERM...DTJ LONG TERM....RRS AVIATION...DTJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1108 AM CDT WED MAY 23 2012 .SHORT TERM... 1101 AM CDT WED MAY 23 2012 LATEST 16Z METARS INDICATE WINDS HAVE INCREASED TO 15 TO 25 KNOTS AND GUST UP TO 33 KNOTS ACROSS PARTS OF SOUTHEAST MINNESOTA AND NORTHEAST IOWA. LATEST 23.14Z RAP BUFKIT SOUNDINGS INDICATE WINDS WILL MIX DOWN FROM ALOFT AND A TIGHT PRESSURE GRADIENT OUT AHEAD OF A COLD FRONT WILL ALLOW WINDS TO INCREASE TO 20 TO 30 MPH WITH GUST UP TO 45 MPH LATE THIS MORNING AND AFTERNOON OVER PORTIONS OF SOUTHEAST MINNESOTA AND NORTHEAST IOWA. THEREFORE...HAVE ISSUED A WIND ADVISORY FOR PARTS OF SOUTHEAST MINNESOTA AND NORTHEAST IOWA. .LONG TERM...SATURDAY THROUGH TUESDAY 344 AM CDT WED MAY 23 2012 MODEL CONSENSUS CONTINUES TO TIGHTEN/IMPROVE THROUGH THE HOLIDAY WEEKEND PERIOD...WITH SAT-TUE FCST CONFIDENCE NOW AVERAGE OR A BIT BETTER. PERSISTENT SOUTH FLOW AHEAD OF THE LEE TROUGH/LOW IN THE PLAINS PUSHES THE WARM FRONT NORTH ACROSS THE AREA SAT/SUN. THIS AS THE LEE LOW EVENTUALLY LIFTS INTO THE NORTHERN PLAINS AND THE MID LEVEL TROUGH SLOWLY EJECTS TOWARD THE NORTHERN PLAINS. CONVECTION EXPECTED TO BE ONGOING NORTH OF THE FRONTAL BOUNDARY SAT...SOMEWHERE ACROSS WI/SOUTHERN MN/NORTHERN IA. THIS CONVECTION HAS POTENTIAL TO STALL THE FRONT/S NORTHWARD PROGRESS ON SAT. ANY BREAKS IN CONVECTION SAT/SAT NIGHT SHOULD ALLOW THE FRONT TO LIFT NORTH OF THE FCST AREA BY OR ON SUNDAY. AGAIN BETTER MODEL SIGNAL FOR THIS TO OCCUR...WITH SUNDAY A VERY WARM/SUMMERY DAY WITH SMALL IF ANY RAIN CHANCES WITH A CAPPED...WARM SECTOR AIRMASS OVER THE AREA. MID LEVEL TROUGH LIFTING ACROSS THE NORTHERN PLAINS INTO SOUTH CAN MON/TUE SENDS A COLD FRONT ACROSS THE AREA ON MON. THIS INTO WHAT SHOULD BE A RATHER MOIST/UNSTABLE AIRMASS OVER THE REGION. SOME TIMING/STRENGTH DIFFERENCES BY MON...SHRA/TSRA CHANCES FROM SUN NIGHT THRU MON NIGHT VERY REASONABLE. MODEL/ENSEMBLE CONSENSUS DATA IN THE DAY 4-7 FCST GRIDS DEPICT THIS QUITE WELL WITH ONLY MINOR ADJUSTMENTS MADE TO BLEND WITH NEIGHBORING GRIDS. && .AVIATION...TODAY AND TONIGHT 626 AM CDT WED MAY 23 2012 WINDY CONDITIONS ON TAP FOR THE TAF SITES TODAY DUE TO A TIGHTENING PRESSURE GRADIENT AHEAD OF A LOW PRESSURE SYSTEM AND COLD FRONT MOVING ACROSS THE DAKOTAS INTO WESTERN MINNESOTA TODAY. SUSTAINED SOUTHERLY WINDS WILL BE AROUND 18 TO 24KT AT RST TODAY AND BETWEEN 12 TO 18KT AT LSE. GUSTS WILL TOP OUT IN THE 28 TO 35KT RANGE THIS AFTERNOON DURING PEAK HEATING. SHOWERS AND THUNDERSTORMS WILL MOVE IN FROM THE WEST TONIGHT AND MAY GET INTO RST AROUND MIDNIGHT OR SHORTLY AFTER. THE PROGRESSION EASTWARD INTO LSE BY 12Z TOMORROW MORNING IS A LITTLE LESS LIKELY...BUT POSSIBLE. CONDITIONS WILL MAINLY BE VFR...BUT IF STORMS DO MAKE IT INTO RST OR LSE THEN THEY MAY DROP TO MVFR/IFR. && .ARX WATCHES/WARNINGS/ADVISORIES... 1101 AM CDT WED MAY 23 2012 WI...NONE. MN...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR MNZ086-087-094-095. IA...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR IAZ008-009-018-019. && $$ SHORT TERM...DTJ LONG TERM....RRS AVIATION...HALBACH