Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 03/23/12
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1040 PM EDT THU MAR 22 2012
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST AND MID ATLANTIC COASTS WILL SINK
FARTHER SOUTH TONIGHT...ALLOWING A COLD FRONT TO MOVE THROUGH LATE
TONIGHT. THE FRONT WILL STALL ALONG THE MID ATLANTIC COAST FRIDAY
INTO FRIDAY NIGHT AS HIGH PRESSURE NOSES DOWN FROM HUDSON BAY INTO
NEW ENGLAND. LOW PRESSURE MOVING ACROSS THE OHIO VALLEY AND MID
ATLANTIC ON SATURDAY WILL PASS TO THE SOUTH SUNDAY THROUGH MONDAY
MORNING. A COLD FRONT WILL MOVE ACROSS MONDAY EVENING...FOLLOWED
BY HIGH PRESSURE ON TUESDAY. ANOTHER WEAK PACIFIC FRONTAL SYSTEM
WILL MOVE ACROSS THE AREA WEDNESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
FOG CONTINUES TO MOVE IN FROM THE OCEAN WATERS. THE HRRR MODEL
SEEMS TO HAVE A RATHER GOOD HANDLE ON THE AREAL COVERAGE OF THE FOG
WITH ITS INITIALIZATION...BUT TIMING IS A COUPLE OF HOURS TOO
EARLY. THEREFORE...HAVE FOLLOWED THIS MODEL IN TERMS OF WHERE THE
FOG WILL SET UP...BUT PUSHING BACK BY ABOUT 2 HOURS. VSBYS
REDUCED TO 1/2 MILE TONIGHT OVER...MAINLY OVER QUEENS...LONG
ISLAND...AND SOUTHERN PORTIONS OF COASTAL CONNECTICUT. CONDITIONS
MAY IMPROVE AFTER 2 AM WITH APPROACH OF COLD FRONT AND A WIND
SHIFT TO A MORE WESTERLY DIRECTION...BUT IF HRRR VERIFIES...WIND
SPEEDS WILL BE LIGHT AND IT MAY TAKE A WHILE FOR THE FOG TO CLEAR
OUT.
FOG FOR THE REST OF THE AREA REMAINS UNCERTAIN. MAIN FACTOR IN
FAVOR OF FOG IS PERSISTENCE...WHICH MOS GUIDANCE IS PICKING UP ON
FOR COASTAL SECTIONS. HOWEVER THERE ARE SOME FACTORS ARGUING
AGAINST... INCLUDING MORE SHALLOW LOW LEVEL MOISTURE...FLOW JUST
OFF THE DECK BECOMING W-NW AHEAD OF THE APPROACHING FRONT AS
OPPOSED TO THE W-SW FLOW OF LAST NIGHT...AND DECREASING DEWPOINTS
ACROSS EASTERN CT/LONG ISLAND LATE TONIGHT WITH FROPA. ALSO OF
NOTE ARE THE LAST TWO RUNS OF THE RGEM...WHICH PERFORMED VERY WELL
WITH EXTENT OF LOW CLOUDS THE PAST COUPLE OF NIGHTS...AND THAT
ONLY SUGGEST CURRENT LOW CLOUDS/FOG OFF EASTERN LONG ISLAND
SCOOTING TO THE EAST THIS EVENING. ANY OUTCOME APPEARS EQUALLY
LIKELY...SO HAVE TAKEN A MIDDLE GROUND APPROACH...WITH PARTLY
CLOUDY SKIES AND PATCHY FOG IN MOST PLACES.
LOWS TONIGHT SHOULD REMAIN AROUND OR JUST ABOVE 60 IN NYC METRO...
WITH 50S ELSEWHERE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
COLD FRONT WILL DROP THROUGH THE AREA BY DAYBREAK FRI...WITH NE-E
FLOW QUICKLY DEVELOPING AFTER SUNRISE...AND THEN WEAKENING BY
MID TO LATE AFTERNOON. FROPA WILL BE FOLLOWED BY A BAND OF MID
LEVEL CLOUDS DROPPING DOWN FROM THE NORTH...WITH PERHAPS A FEW
SPRINKLES NORTH/WEST OF NYC. ANOTHER MILD DAY IS IN STORE...WITH
875 MB TEMPS NEAR +8C PER 12Z NAM KEWR AFTERNOON FCST SOUNDINGS
AND FULL MIXING UP TO THAT LEVEL SUPPORTIVE OF HIGHS IN THE
LOWER 70S IN NYC METRO AND 65-70 ELSEWHERE.
THE FRONT SHOULD STALL NOT TOO FAR TO THE SOUTH FRI NIGHT AS UPPER
RIDGING HOLDS ON AHEAD OF A CLOSED LOW APPROACHING FROM THE OHIO
VALLEY. A MID LEVEL CLOUD DECK LINGERING OVER THE REGION SHOULD
HELP KEEP LOWS FROM DROPPING TOO MUCH...WITH 50-55 IN NYC METRO
AND 40S ELSEWHERE.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AN ANOMALOUS UPPER RIDGE EAST OF THE ROCKIES WILL PROGRESS EAST INTO
EARLY NEXT WEEK...WHILE A CLOSED LOW OVER THE OHIO VALLEY DOES SO IN
TANDEM. THERE IS SOME UNCERTAINTY WITH THE MAGNITUDE AND PROGRESSION
OF THIS FEATURE AS IT REMAINS DETACHED FROM THE WESTERLIES. THIS
WILL PLACE THE TRI-STATE AREA IN A MID LEVEL DEFORMATION ZONE WITH
WEAK FRONTOGENETIC FORCING TO THE NORTH OF THE LOW TRACK. THE LOW IS
FORECAST TO GO FROM THE OHIO VALLEY STATES ON SAT TO OFF THE MID
ATLANTIC COAST SUN NIGHT. THE 00Z ECMWF WHICH WAS THE SLOWEST OF THE
GLOBAL MODELS HAS TRENDED FASTER BUT STILL REMAINS ON THE WESTERN
ENVELOPE OF THE MODEL ENSEMBLE. PREFERENCE AT THIS TIME WAS TO GO
WITH A MIDDLE ROAD SOLUTION BETWEEN THE GFS AND ECMWF...ACCOUNTING
FOR UNCERTAINTY WITH THE PROGRESSION OF THE CLOSED UPPER LOW.
THUS...LOOKING AT INCREASING RAIN CHANCE SAT INTO SUN. CONDITIONS
THEN DRY OUT SUN NIGHT INTO MON ON THE BACKSIDE OF THE DEPARTING
LOW. THERE IS A MODERATE SHOT OF COLD ADVECTION MON AFT AND
NIGHT...WHICH WILL BRIEFLY RETURN THE AREA TO NEARLY SEASONABLE
CONDITIONS TUE AND WED...OTHERWISE TEMPS WILL BE ABOUT 5 TO 10
DEGREES ABOVE NORMAL.
HIGH PRESSURE FOLLOWS FOR TUE AND WED WITH A WEAK PAC FRONTAL SYSTEM
MOVING THROUGH THE AREA WED NIGHT INTO THU.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
A WEAK FRONT ACROSS CNTRL NY STATE WILL PASS FROM THE N LATE TNGT.
WEAK BOUNDARY HAS PASSED...SHUNTING THE FOG EWD. HAVE THEREFORE
IMPROVED THE TAFS. STILL SOME UNCERTAINTY WRT THE REDEVELOPMENT OF
FOG BEFORE THE MAIN FRONT LATE TNGT. HAVE MAINTAINED SOME
REDUCTIONS IN THE TAFS...MAINLY AFT 4Z.
CHALLENGING FORECAST REMAINS AHEAD OF THE FRONT. WOULD EXPECT
POSSIBLE RETURN TO STRATUS AND FOG AHEAD OF THE FRONT. THEN
CONDITIONS SLOWLY IMPROVE AFTER MIDNIGHT AS THE FRONT MOVES
THROUGH. VFR FRIDAY MORNING THRU FRI EVE WITH E/NE WINDS BEHIND
THE FRONT 10 KT OR LESS.
OUTLOOK FOR 00Z SATURDAY THROUGH TUESDAY...
.FRIDAY NIGHT...VFR.
.SATURDAY-MONDAY...SUB VFR POSSIBLE IN RAIN SHOWERS.
.MONDAY NIGHT-TUESDAY...MAINLY VFR. GUSTY N WINDS.
&&
.MARINE...
ADVY FOR FOG HAS BEEN CANCELLED FOR THE HARBOR AS THE FOG HAS BEEN
FORCED EWD OVER THE OCEAN. NO OTHER CHANGES. IMPROVEMENT FROM W TO
E IS EXPECTED LATE TNGT AS A WEAK FRONT PASSES. PATCHY FOG
DEVELOPMENT IS POSSIBLE TIL THIS PASSAGE.
GUSTS IN E FLOW BETWEEN HIGH PRESSURE OVER NEW ENGLAND AND A
STATIONARY FRONT OVER THE MID ATLC REGION COULD APPROACH 25 KT ON
THE OCEAN BEGINNING LATE FRI NIGHT. THIS FLOW WILL PERSIST INTO
THE WEEKEND AND LIKELY PRODUCE SCA CONDITIONS IN THE FORM OF ROUGH
OCEAN SEAS SAT NIGHT INTO SUNDAY. THERE IS SOME UNCERTAINTY WITH
THE LOCATION OF LOW PRESSURE TRACKING TO THE SOUTH AND OFF THE MID
ATLANTIC COAST SUNDAY INTO SUNDAY NIGHT. THIS WILL BE KEY IN
DETERMINING WHERE THE COASTAL WATERS RESIDE WITH RESPECT TO THE
STRONGEST EASTERLY GRADIENT. THERE MAY BE A BRIEF RESPITE IN SCA
CONDITIONS EARLY MON ON THE BACK SIDE OF THE LOW. HOWEVER...A
TIGHTENING NORTHERLY GRADIENT MON AFTERNOON WILL LIKELY BRING SCA
CONDITIONS TO ALL WATERS MON NIGHT INTO TUE...WITH POSSIBLE GALE
FORCE GUSTS ON THE OCEAN WATERS MON NIGHT.
&&
.HYDROLOGY...
QPF OF 1/4 TO 1/2 INCH IS POSSIBLE FROM SAT AFTERNOON THROUGH SUNDAY
NIGHT AS LOW PRESSURE PASSES TO THE SOUTH. FLOODING IS NOT
FORECAST.
&&
.CLIMATE...
RECORD HIGH TEMPERATURES FOR MARCH 22
..LOCATION........ACTUAL HIGH........RECORD HIGH..........YEAR....
CENTRAL PARK NY........78...................77............1938....
LAGUARDIA NY...........75...................75............1948....
KENNEDY NY.............66...................68............1979....
NEWARK NJ..............79...................80............1938....
ISLIP NY...............73...................67............2003....
BRIDGEPORT CT..........69...................63............2003....
RECORD HIGH TEMPERATURES FOR MARCH 23
..LOCATION........FORECAST HIGH........RECORD HIGH........YEAR....
CENTRAL PARK NY........77...................76............1923....
LAGUARDIA NY...........74...................70............1994....
KENNEDY NY.............67...................69............1994....
NEWARK NJ..............74...................82............1938....
ISLIP NY...............68...................69............1994....
BRIDGEPORT CT..........69...................68............1990....
RECORD HIGH MINIMUM TEMPERATURE FOR MARCH 23
..LOCATION........FORECAST LOW........RECORD LOW MAX......YEAR....
CENTRAL PARK NY........61...................56............1938....
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 2 AM EDT FRIDAY FOR ANZ345-350-353-
355.
&&
$$
SYNOPSIS...GOODMAN
NEAR TERM...JP
SHORT TERM...JP
LONG TERM...DW
AVIATION...JMC/PW
MARINE...JMC/GOODMAN/DW
HYDROLOGY...DW
CLIMATE...GOODMAN
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1007 PM EDT THU MAR 22 2012
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST AND MID ATLANTIC COASTS WILL SINK
FARTHER SOUTH TONIGHT...ALLOWING A COLD FRONT TO MOVE THROUGH LATE
TONIGHT. THE FRONT WILL STALL ALONG THE MID ATLANTIC COAST FRIDAY
INTO FRIDAY NIGHT AS HIGH PRESSURE NOSES DOWN FROM HUDSON BAY INTO
NEW ENGLAND. LOW PRESSURE MOVING ACROSS THE OHIO VALLEY AND MID
ATLANTIC ON SATURDAY WILL PASS TO THE SOUTH SUNDAY THROUGH MONDAY
MORNING. A COLD FRONT WILL MOVE ACROSS MONDAY EVENING...FOLLOWED
BY HIGH PRESSURE ON TUESDAY. ANOTHER WEAK PACIFIC FRONTAL SYSTEM
WILL MOVE ACROSS THE AREA WEDNESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
FOG CONTINUES TO MOVE IN FROM THE OCEAN WATERS. THE HRRR MODEL
SEEMS TO HAVE A RATHER GOOD HANDLE ON THE AREAL COVERAGE OF THE FOG
WITH ITS INITIALIZATION...BUT TIMING IS A COUPLE OF HOURS TOO
EARLY. THEREFORE...HAVE FOLLOWED THIS MODEL IN TERMS OF WHERE THE
FOG WILL SET UP...BUT PUSHING BACK BY ABOUT 2 HOURS. VSBYS
REDUCED TO 1/2 MILE TONIGHT OVER...MAINLY OVER QUEENS...LONG
ISLAND...AND SOUTHERN PORTIONS OF COASTAL CONNECTICUT. CONDITIONS
MAY IMPROVE AFTER 2 AM WITH APPROACH OF COLD FRONT AND A WIND
SHIFT TO A MORE WESTERLY DIRECTION...BUT IF HRRR VERIFIES...WIND
SPEEDS WILL BE LIGHT AND IT MAY TAKE A WHILE FOR THE FOG TO CLEAR
OUT.
FOG FOR THE REST OF THE AREA REMAINS UNCERTAIN. MAIN FACTOR IN
FAVOR OF FOG IS PERSISTENCE...WHICH MOS GUIDANCE IS PICKING UP ON
FOR COASTAL SECTIONS. HOWEVER THERE ARE SOME FACTORS ARGUING
AGAINST... INCLUDING MORE SHALLOW LOW LEVEL MOISTURE...FLOW JUST
OFF THE DECK BECOMING W-NW AHEAD OF THE APPROACHING FRONT AS
OPPOSED TO THE W-SW FLOW OF LAST NIGHT...AND DECREASING DEWPOINTS
ACROSS EASTERN CT/LONG ISLAND LATE TONIGHT WITH FROPA. ALSO OF
NOTE ARE THE LAST TWO RUNS OF THE RGEM...WHICH PERFORMED VERY WELL
WITH EXTENT OF LOW CLOUDS THE PAST COUPLE OF NIGHTS...AND THAT
ONLY SUGGEST CURRENT LOW CLOUDS/FOG OFF EASTERN LONG ISLAND
SCOOTING TO THE EAST THIS EVENING. ANY OUTCOME APPEARS EQUALLY
LIKELY...SO HAVE TAKEN A MIDDLE GROUND APPROACH...WITH PARTLY
CLOUDY SKIES AND PATCHY FOG IN MOST PLACES.
LOWS TONIGHT SHOULD REMAIN AROUND OR JUST ABOVE 60 IN NYC METRO...
WITH 50S ELSEWHERE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
COLD FRONT WILL DROP THROUGH THE AREA BY DAYBREAK FRI...WITH NE-E
FLOW QUICKLY DEVELOPING AFTER SUNRISE...AND THEN WEAKENING BY
MID TO LATE AFTERNOON. FROPA WILL BE FOLLOWED BY A BAND OF MID
LEVEL CLOUDS DROPPING DOWN FROM THE NORTH...WITH PERHAPS A FEW
SPRINKLES NORTH/WEST OF NYC. ANOTHER MILD DAY IS IN STORE...WITH
875 MB TEMPS NEAR +8C PER 12Z NAM KEWR AFTERNOON FCST SOUNDINGS
AND FULL MIXING UP TO THAT LEVEL SUPPORTIVE OF HIGHS IN THE
LOWER 70S IN NYC METRO AND 65-70 ELSEWHERE.
THE FRONT SHOULD STALL NOT TOO FAR TO THE SOUTH FRI NIGHT AS UPPER
RIDGING HOLDS ON AHEAD OF A CLOSED LOW APPROACHING FROM THE OHIO
VALLEY. A MID LEVEL CLOUD DECK LINGERING OVER THE REGION SHOULD
HELP KEEP LOWS FROM DROPPING TOO MUCH...WITH 50-55 IN NYC METRO
AND 40S ELSEWHERE.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AN ANOMALOUS UPPER RIDGE EAST OF THE ROCKIES WILL PROGRESS EAST INTO
EARLY NEXT WEEK...WHILE A CLOSED LOW OVER THE OHIO VALLEY DOES SO IN
TANDEM. THERE IS SOME UNCERTAINTY WITH THE MAGNITUDE AND PROGRESSION
OF THIS FEATURE AS IT REMAINS DETACHED FROM THE WESTERLIES. THIS
WILL PLACE THE TRI-STATE AREA IN A MID LEVEL DEFORMATION ZONE WITH
WEAK FRONTOGENETIC FORCING TO THE NORTH OF THE LOW TRACK. THE LOW IS
FORECAST TO GO FROM THE OHIO VALLEY STATES ON SAT TO OFF THE MID
ATLANTIC COAST SUN NIGHT. THE 00Z ECMWF WHICH WAS THE SLOWEST OF THE
GLOBAL MODELS HAS TRENDED FASTER BUT STILL REMAINS ON THE WESTERN
ENVELOPE OF THE MODEL ENSEMBLE. PREFERENCE AT THIS TIME WAS TO GO
WITH A MIDDLE ROAD SOLUTION BETWEEN THE GFS AND ECMWF...ACCOUNTING
FOR UNCERTAINTY WITH THE PROGRESSION OF THE CLOSED UPPER LOW.
THUS...LOOKING AT INCREASING RAIN CHANCE SAT INTO SUN. CONDITIONS
THEN DRY OUT SUN NIGHT INTO MON ON THE BACKSIDE OF THE DEPARTING
LOW. THERE IS A MODERATE SHOT OF COLD ADVECTION MON AFT AND
NIGHT...WHICH WILL BRIEFLY RETURN THE AREA TO NEARLY SEASONABLE
CONDITIONS TUE AND WED...OTHERWISE TEMPS WILL BE ABOUT 5 TO 10
DEGREES ABOVE NORMAL.
HIGH PRESSURE FOLLOWS FOR TUE AND WED WITH A WEAK PAC FRONTAL SYSTEM
MOVING THROUGH THE AREA WED NIGHT INTO THU.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
A WEAK FRONT WILL PASS FROM THE N LATE TNGT.
2Z UPDATE...WEAK BOUNDARY HAS PASSED...SHUNTING THE FOG EWD THIS
EVE. HAVE THEREFORE IMPROVED THE TAFS. STILL SOME UNCERTAINTY WRT
THE REDEVELOPMENT OF FOG BEFORE THE MAIN FRONT LATE TNGT. HAVE
MAINTAINED SOME REDUCTIONS IN THE TAFS...MAINLY AFT 4Z.
CHALLENGING FORECAST REMAINS AHEAD OF THE FRONT. WOULD EXPECT
POSSIBLE RETURN TO STRATUS AND FOG AHEAD OF THE FRONT. THEN
CONDITIONS SLOWLY IMPROVE AFTER MIDNIGHT AS THE FRONT MOVES
THROUGH. VFR FRIDAY MORNING THRU FRI EVE WITH E/NE WINDS BEHIND
THE FRONT 10 KT OR LESS.
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)
KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS EVENING DUE TO
POSSIBLE LOW CLOUDS AND FOG.
KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS EVENING DUE TO
POSSIBLE LOW CLOUDS AND FOG.
KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS EVENING DUE TO POSSIBLE
LOW CLOUDS AND FOG.
KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS EVENING DUE TO POSSIBLE
LOW CLOUDS AND FOG.
KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS EVENING DUE TO POSSIBLE
LOW CLOUDS AND FOG.
KISP FCSTER COMMENTS: AMENDMENTS LIKELY TONIGHT FOR STRATUS/FOG
REDEVELOPMENT.
OUTLOOK FOR 00Z SATURDAY THROUGH TUESDAY...
.FRIDAY NIGHT...VFR.
.SATURDAY-MONDAY...SUB VFR POSSIBLE IN RAIN SHOWERS.
.MONDAY NIGHT-TUESDAY...MAINLY VFR. GUSTY N WINDS.
&&
.MARINE...
FOG HAS ADVECTED INTO NEW YORK HARBOR...ATLANTIC COASTAL
OCEAN ZONES...AND SOUTH SHORE BAYS. A DENSE FOG ADVISORY HAS BEEN
ISSUED THROUGH 2 AM. VSBYS OF 1/2 NM CAN BE EXPECTED...WITH
IMPROVING CONDITIONS POSSIBLE AFTER 2 AM AS COLD FRONT APPROACHES
AND WINDS SHIFT TO MORE OF A SOUTHWESTERLY DIRECTION. THE FOG
COULD MAKE ITS WAY INTO THE SOUND...BUT WILL HOLD OFF ON ISSUING
AN ADVISORY HERE UNTIL WE SEE THE PROGRESSION OVER THE NEXT COUPLE
OF HOURS.
GUSTS IN E FLOW BETWEEN HIGH PRESSURE OVER NEW ENGLAND AND A
STATIONARY FRONT OVER THE MID ATLC REGION COULD APPROACH 25 KT ON
THE OCEAN BEGINNING LATE FRI NIGHT. THIS FLOW WILL PERSIST INTO
THE WEEKEND AND LIKELY PRODUCE SCA CONDITIONS IN THE FORM OF ROUGH
OCEAN SEAS SAT NIGHT INTO SUNDAY. THERE IS SOME UNCERTAINTY WITH
THE LOCATION OF LOW PRESSURE TRACKING TO THE SOUTH AND OFF THE MID
ATLANTIC COAST SUNDAY INTO SUNDAY NIGHT. THIS WILL BE KEY IN
DETERMINING WHERE THE COASTAL WATERS RESIDE WITH RESPECT TO THE
STRONGEST EASTERLY GRADIENT. THERE MAY BE A BRIEF RESPITE IN SCA
CONDITIONS EARLY MON ON THE BACK SIDE OF THE LOW. HOWEVER...A
TIGHTENING NORTHERLY GRADIENT MON AFTERNOON WILL LIKELY BRING SCA
CONDITIONS TO ALL WATERS MON NIGHT INTO TUE...WITH POSSIBLE GALE
FORCE GUSTS ON THE OCEAN WATERS MON NIGHT.
&&
.HYDROLOGY...
QPF OF 1/4 TO 1/2 INCH IS POSSIBLE FROM SAT AFTERNOON THROUGH SUNDAY
NIGHT AS LOW PRESSURE PASSES TO THE SOUTH. FLOODING IS NOT
FORECAST.
&&
.CLIMATE...
RECORD HIGH TEMPERATURES FOR MARCH 22
..LOCATION........ACTUAL HIGH........RECORD HIGH..........YEAR....
CENTRAL PARK NY........78...................77............1938....
LAGUARDIA NY...........75...................75............1948....
KENNEDY NY.............66...................68............1979....
NEWARK NJ..............79...................80............1938....
ISLIP NY...............73...................67............2003....
BRIDGEPORT CT..........69...................63............2003....
RECORD HIGH TEMPERATURES FOR MARCH 23
..LOCATION........FORECAST HIGH........RECORD HIGH........YEAR....
CENTRAL PARK NY........77...................76............1923....
LAGUARDIA NY...........74...................70............1994....
KENNEDY NY.............67...................69............1994....
NEWARK NJ..............74...................82............1938....
ISLIP NY...............68...................69............1994....
BRIDGEPORT CT..........69...................68............1990....
RECORD HIGH MINIMUM TEMPERATURE FOR MARCH 23
..LOCATION........FORECAST LOW........RECORD LOW MAX......YEAR....
CENTRAL PARK NY........61...................56............1938....
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 2 AM EDT FRIDAY FOR ANZ338-345-350-
353-355.
&&
$$
SYNOPSIS...GOODMAN
NEAR TERM...JP
SHORT TERM...JP
LONG TERM...DW
AVIATION...JMC/PW
MARINE...GOODMAN/DW
HYDROLOGY...DW
CLIMATE...GOODMAN
AREA FORECAST DISCUSSION
NWS NEW YORK NY
950 PM EDT THU MAR 22 2012
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST AND MID ATLANTIC COASTS WILL SINK
FARTHER SOUTH TONIGHT...ALLOWING A COLD FRONT TO MOVE THROUGH LATE
TONIGHT. THE FRONT WILL STALL ALONG THE MID ATLANTIC COAST FRIDAY
INTO FRIDAY NIGHT AS HIGH PRESSURE NOSES DOWN FROM HUDSON BAY INTO
NEW ENGLAND. LOW PRESSURE MOVING ACROSS THE OHIO VALLEY AND MID
ATLANTIC ON SATURDAY WILL PASS TO THE SOUTH SUNDAY THROUGH MONDAY
MORNING. A COLD FRONT WILL MOVE ACROSS MONDAY EVENING...FOLLOWED
BY HIGH PRESSURE ON TUESDAY. ANOTHER WEAK PACIFIC FRONTAL SYSTEM
WILL MOVE ACROSS THE AREA WEDNESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
FOG CONTINUES TO MOVE IN FROM THE OCEAN WATERS. THE HRRR MODEL
SEEMS TO HAVE A RATHER GOOD HANDLE ON THE AREAL COVERAGE OF THE FOG
WITH ITS INITIALIZATION...BUT TIMING IS A COUPLE OF HOURS TOO
EARLY. THEREFORE...HAVE FOLLOWED THIS MODEL IN TERMS OF WHERE THE
FOG WILL SET UP...BUT PUSHING BACK BY ABOUT 2 HOURS. VSBYS
REDUCED TO 1/2 MILE TONIGHT OVER...MAINLY OVER QUEENS...LONG
ISLAND...AND SOUTHERN PORTIONS OF COASTAL CONNECTICUT. CONDITIONS
MAY IMPROVE AFTER 2 AM WITH APPROACH OF COLD FRONT AND A WIND
SHIFT TO A MORE WESTERLY DIRECTION...BUT IF HRRR VERIFIES...WIND
SPEEDS WILL BE LIGHT AND IT MAY TAKE A WHILE FOR THE FOG TO CLEAR
OUT.
FOG FOR THE REST OF THE AREA REMAINS UNCERTAIN. MAIN FACTOR IN
FAVOR OF FOG IS PERSISTENCE...WHICH MOS GUIDANCE IS PICKING UP ON
FOR COASTAL SECTIONS. HOWEVER THERE ARE SOME FACTORS ARGUING
AGAINST... INCLUDING MORE SHALLOW LOW LEVEL MOISTURE...FLOW JUST
OFF THE DECK BECOMING W-NW AHEAD OF THE APPROACHING FRONT AS
OPPOSED TO THE W-SW FLOW OF LAST NIGHT...AND DECREASING DEWPOINTS
ACROSS EASTERN CT/LONG ISLAND LATE TONIGHT WITH FROPA. ALSO OF
NOTE ARE THE LAST TWO RUNS OF THE RGEM...WHICH PERFORMED VERY WELL
WITH EXTENT OF LOW CLOUDS THE PAST COUPLE OF NIGHTS...AND THAT
ONLY SUGGEST CURRENT LOW CLOUDS/FOG OFF EASTERN LONG ISLAND
SCOOTING TO THE EAST THIS EVENING. ANY OUTCOME APPEARS EQUALLY
LIKELY...SO HAVE TAKEN A MIDDLE GROUND APPROACH...WITH PARTLY
CLOUDY SKIES AND PATCHY FOG IN MOST PLACES.
LOWS TONIGHT SHOULD REMAIN AROUND OR JUST ABOVE 60 IN NYC METRO...
WITH 50S ELSEWHERE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
COLD FRONT WILL DROP THROUGH THE AREA BY DAYBREAK FRI...WITH NE-E
FLOW QUICKLY DEVELOPING AFTER SUNRISE...AND THEN WEAKENING BY
MID TO LATE AFTERNOON. FROPA WILL BE FOLLOWED BY A BAND OF MID
LEVEL CLOUDS DROPPING DOWN FROM THE NORTH...WITH PERHAPS A FEW
SPRINKLES NORTH/WEST OF NYC. ANOTHER MILD DAY IS IN STORE...WITH
875 MB TEMPS NEAR +8C PER 12Z NAM KEWR AFTERNOON FCST SOUNDINGS
AND FULL MIXING UP TO THAT LEVEL SUPPORTIVE OF HIGHS IN THE
LOWER 70S IN NYC METRO AND 65-70 ELSEWHERE.
THE FRONT SHOULD STALL NOT TOO FAR TO THE SOUTH FRI NIGHT AS UPPER
RIDGING HOLDS ON AHEAD OF A CLOSED LOW APPROACHING FROM THE OHIO
VALLEY. A MID LEVEL CLOUD DECK LINGERING OVER THE REGION SHOULD
HELP KEEP LOWS FROM DROPPING TOO MUCH...WITH 50-55 IN NYC METRO
AND 40S ELSEWHERE.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AN ANOMALOUS UPPER RIDGE EAST OF THE ROCKIES WILL PROGRESS EAST INTO
EARLY NEXT WEEK...WHILE A CLOSED LOW OVER THE OHIO VALLEY DOES SO IN
TANDEM. THERE IS SOME UNCERTAINTY WITH THE MAGNITUDE AND PROGRESSION
OF THIS FEATURE AS IT REMAINS DETACHED FROM THE WESTERLIES. THIS
WILL PLACE THE TRI-STATE AREA IN A MID LEVEL DEFORMATION ZONE WITH
WEAK FRONTOGENETIC FORCING TO THE NORTH OF THE LOW TRACK. THE LOW IS
FORECAST TO GO FROM THE OHIO VALLEY STATES ON SAT TO OFF THE MID
ATLANTIC COAST SUN NIGHT. THE 00Z ECMWF WHICH WAS THE SLOWEST OF THE
GLOBAL MODELS HAS TRENDED FASTER BUT STILL REMAINS ON THE WESTERN
ENVELOPE OF THE MODEL ENSEMBLE. PREFERENCE AT THIS TIME WAS TO GO
WITH A MIDDLE ROAD SOLUTION BETWEEN THE GFS AND ECMWF...ACCOUNTING
FOR UNCERTAINTY WITH THE PROGRESSION OF THE CLOSED UPPER LOW.
THUS...LOOKING AT INCREASING RAIN CHANCE SAT INTO SUN. CONDITIONS
THEN DRY OUT SUN NIGHT INTO MON ON THE BACKSIDE OF THE DEPARTING
LOW. THERE IS A MODERATE SHOT OF COLD ADVECTION MON AFT AND
NIGHT...WHICH WILL BRIEFLY RETURN THE AREA TO NEARLY SEASONABLE
CONDITIONS TUE AND WED...OTHERWISE TEMPS WILL BE ABOUT 5 TO 10
DEGREES ABOVE NORMAL.
HIGH PRESSURE FOLLOWS FOR TUE AND WED WITH A WEAK PAC FRONTAL SYSTEM
MOVING THROUGH THE AREA WED NIGHT INTO THU.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
A WEAK FRONT WILL PASS FROM THE N LATE TNGT.
FOG BEGINNING TO SHOW UP AT LONG BEACH...WITH METARS INDICATING IT
IS VISIBLE FROM KJFK. 00Z TAFS WILL BRING IN THE FOG RIGHT AWAY AT
JFK...BUT RETAIN THE CURRENT TIMING ELSEWHERE.
CHALLENGING FORECAST REMAINS AHEAD OF THE FRONT. WOULD EXPECT
POSSIBLE RETURN TO STRATUS AND FOG AHEAD OF THE FRONT. THEN
CONDITIONS SLOWLY IMPROVE AFTER MIDNIGHT AS THE FRONT MOVES
THROUGH. VFR FRIDAY MORNING THRU FRI EVE WITH E/NE WINDS BEHIND
THE FRONT 10 KT OR LESS.
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)
KEWR FCSTER COMMENTS: AMENDMENTS LIKELY THIS EVENING DUE TO
POSSIBLE LOW CLOUDS AND FOG.
KJFK FCSTER COMMENTS: ARPT IS CURRENTLY ON THE EDGE OF THE FOG.
AMENDMENTS POSSIBLE THRU THIS EVE FOR EXACT TIMING AND REFINED
FCST VSBY.
KLGA FCSTER COMMENTS: AMENDMENTS LIKELY THIS EVENING DUE TO POSSIBLE
LOW CLOUDS AND FOG.
KTEB FCSTER COMMENTS: AMENDMENTS LIKELY THIS EVENING DUE TO
POSSIBLE LOW CLOUDS AND FOG.
KHPN FCSTER COMMENTS: AMENDMENTS LIKELY THIS EVENING DUE TO
POSSIBLE LOW CLOUDS AND FOG.
KISP FCSTER COMMENTS: AMENDMENTS LIKELY THIS EVENING AND TONIGHT
FOR STRATUS/FOG REDEVELOPMENT.
OUTLOOK FOR 00Z SATURDAY THROUGH TUESDAY...
.FRIDAY NIGHT...VFR.
.SATURDAY-MONDAY...SUB VFR POSSIBLE IN RAIN SHOWERS.
.MONDAY NIGHT-TUESDAY...MAINLY VFR. GUSTY N WINDS.
&&
.MARINE...
FOG HAS ADVECTED INTO NEW YORK HARBOR...ATLANTIC COASTAL
OCEAN ZONES...AND SOUTH SHORE BAYS. A DENSE FOG ADVISORY HAS BEEN
ISSUED THROUGH 2 AM. VSBYS OF 1/2 NM CAN BE EXPECTED...WITH
IMPROVING CONDITIONS POSSIBLE AFTER 2 AM AS COLD FRONT APPROACHES
AND WINDS SHIFT TO MORE OF A SOUTHWESTERLY DIRECTION. THE FOG
COULD MAKE ITS WAY INTO THE SOUND...BUT WILL HOLD OFF ON ISSUING
AN ADVISORY HERE UNTIL WE SEE THE PROGRESSION OVER THE NEXT COUPLE
OF HOURS.
GUSTS IN E FLOW BETWEEN HIGH PRESSURE OVER NEW ENGLAND AND A
STATIONARY FRONT OVER THE MID ATLC REGION COULD APPROACH 25 KT ON
THE OCEAN BEGINNING LATE FRI NIGHT. THIS FLOW WILL PERSIST INTO
THE WEEKEND AND LIKELY PRODUCE SCA CONDITIONS IN THE FORM OF ROUGH
OCEAN SEAS SAT NIGHT INTO SUNDAY. THERE IS SOME UNCERTAINTY WITH
THE LOCATION OF LOW PRESSURE TRACKING TO THE SOUTH AND OFF THE MID
ATLANTIC COAST SUNDAY INTO SUNDAY NIGHT. THIS WILL BE KEY IN
DETERMINING WHERE THE COASTAL WATERS RESIDE WITH RESPECT TO THE
STRONGEST EASTERLY GRADIENT. THERE MAY BE A BRIEF RESPITE IN SCA
CONDITIONS EARLY MON ON THE BACK SIDE OF THE LOW. HOWEVER...A
TIGHTENING NORTHERLY GRADIENT MON AFTERNOON WILL LIKELY BRING SCA
CONDITIONS TO ALL WATERS MON NIGHT INTO TUE...WITH POSSIBLE GALE
FORCE GUSTS ON THE OCEAN WATERS MON NIGHT.
&&
.HYDROLOGY...
QPF OF 1/4 TO 1/2 INCH IS POSSIBLE FROM SAT AFTERNOON THROUGH SUNDAY
NIGHT AS LOW PRESSURE PASSES TO THE SOUTH. FLOODING IS NOT
FORECAST.
&&
.CLIMATE...
RECORD HIGH TEMPERATURES FOR MARCH 22
..LOCATION........ACTUAL HIGH........RECORD HIGH..........YEAR....
CENTRAL PARK NY........78...................77............1938....
LAGUARDIA NY...........75...................75............1948....
KENNEDY NY.............66...................68............1979....
NEWARK NJ..............79...................80............1938....
ISLIP NY...............73...................67............2003....
BRIDGEPORT CT..........69...................63............2003....
RECORD HIGH TEMPERATURES FOR MARCH 23
..LOCATION........FORECAST HIGH........RECORD HIGH........YEAR....
CENTRAL PARK NY........77...................76............1923....
LAGUARDIA NY...........74...................70............1994....
KENNEDY NY.............67...................69............1994....
NEWARK NJ..............74...................82............1938....
ISLIP NY...............68...................69............1994....
BRIDGEPORT CT..........69...................68............1990....
RECORD HIGH MINIMUM TEMPERATURE FOR MARCH 23
..LOCATION........FORECAST LOW........RECORD LOW MAX......YEAR....
CENTRAL PARK NY........61...................56............1938....
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 2 AM EDT FRIDAY FOR ANZ338-345-350-
353-355.
&&
$$
SYNOPSIS...GOODMAN
NEAR TERM...JP
SHORT TERM...JP
LONG TERM...DW
AVIATION...JMC/PW
MARINE...GOODMAN/DW
HYDROLOGY...DW
CLIMATE...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
556 PM EDT WED MAR 21 2012
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE ANCHORED OFF THE MID ATLANTIC
COAST WILL SINK SLOWLY SOUTH THROUGH FRIDAY. LOW PRESSURE,
MOVING IN FROM THE WEST WILL CROSS OUR AREA OVER THE WEEKEND
AND THEN HEAD OFF TO THE EAST LATER SUNDAY NIGHT AND MONDAY.
HIGH PRESSURE WILL THEN MOVE IN AND DOMINATE OUR WEATHER
INTO WEDNESDAY. BY LATE WEDNESDAY, LOW PRESSURE, MOVING EAST
ACROSS THE GREAT LAKES, AND IT`S ASSOCIATED COLD FRONT, WILL
BE APPROACHING OUR REGION.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
ESTF UPDATE TO ADJUST SHRAS CHANCES, MAINLY TO CUT THEM OFF SOONER
BASED ON 18Z NAM LATEST HRRR AND CURRENT RADAR DEPICTION. THUNDER
GONE AS OUR PREDECESSORS HAD. WE STARTED THE FOG A LITTLE EARLIER
BASED ON A SPOTTER REPORT FROM OCEAN COUNTY. TEMPERATURES AND DEW
POINTS NEEDED VERY FEW ADJUSTMENTS.
THE LOW LEVEL FLOW GRADUALLY BECOMES MORE OFFSHORE OVERNIGHT, BUT
SAID FLOW IS RATHER LIGHT AND THE TRAJECTORY OF THE AIR COMES FROM A
FAIRLY HUMID PLACE. IT DOESN`T SEEM THAT WE GET SCOURED OUT. THERE
ALSO DOESN`T APPEAR TO BE A LOT OF MOISTURE ALOFT MOST PLACES, SO
WHATEVER CLEARING WE GET THIS EVENING IS EXPECTED TO BE FOLLOWED BY
MORE LOW CLOUDS AND FOG. WE TOOK A LOOK AT THE MID LEVEL LOW THAT IS
FORECAST TO DRIFT EAST OVERNIGHT AND ADDED SOME LOW CHANCE POPS NEAR
AND EAST OF THE TROUGH AXIS. WE AVOIDED ANY MENTION OF THUNDER FOR
NOW.
IF WE GET DECENT RADIATING, THEN THE TEMPERATURES MAY DRIVE DOWN THE
19Z DEW POINTS. ALSO, THERE IS A CHANCE OF SOME MIXING OUT OF SAID
DEW POINTS DURING THE REMAINS OF THE DAY. STILL, THOSE 19Z DEW
POINTS WERE QUITE HIGH, AND SO OUR OVERNIGHT MINS ARE ON THE MILD
SIDE OF GUIDANCE.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
SOME MARGINALLY DRIER AIR IS FORECAST TO MOVE INTO THE AREA JUST
ABOVE THE SURFACE AS THE MID LEVEL LOW OPENS AND CONTINUES EAST
SLOWLY, AND THAT MAY ALLOW FOR MORE MIXING AND SUNSHINE ON THURSDAY
THAN WE HAD TODAY (ESPECIALLY AS ONE MOVES NORTHWEST THROUGH THE
FORECAST AREA). IT ALSO MAY ALLOW EXPECTED LOW CLOUDS AND FOG TO
DISSIPATE MORE QUICKLY. THE SURFACE FLOW LOOKS SOUTH-SOUTHWEST, AND
THAT IS NOT A PARTICULARLY DRY FLOW. OUR FORECAST MAXES ARE
OPTIMISTIC ABOUT US MIXING UP TO H925, AND IF WE DON`T, THEN THEY
WOULD BE TOO HIGH. WE JUST CARRY SOME LOW CHANCE POPS FAR SOUTHEAST
OUT OF RESPECT FOR THE MID LEVEL LOW.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
A BERMUDA TYPE HIGH PRESSURE SYSTEM, OFF THE MID ATLANTIC COAST,
WILL CONTINUE TO SINK SLOWLY SOUTH THROUGH FRIDAY. A WEAK
BACKDOOR FRONTAL ZONE COULD DROP SOUTH ACROSS OUR REGION LATE
THURSDAY NIGHT INTO FRIDAY. THE ONLY EFFECT THIS MIGHT HAVE IS
TO BRIEFLY TURN THE WINDS TO A NORTHWEST DIRECTION. THIS COULD
HELP INHIBIT DENSE FOG FROM FORMING THURSDAY NIGHT. OTHERWISE,
OUR WARM WEATHER WILL CONTINUE. EVEN WITH MOSTLY CLEAR TO PARTLY
CLOUDY SKIES, LOW TEMPERATURES THURSDAY NIGHT WILL BE MAINLY IN
THE 50S. FRIDAY COULD TURN OUT TO BE THE WARMEST DAY OF THE WEEK,
WITH HIGHS IN THE 70S TO LOWER 80S. THE ONLY EXCEPTION TO THIS
WILL BE COASTAL SECTIONS, WHERE TEMPERATURES WILL REMAIN IN THE
MID TO UPPER 60S. WE`LL THEN TURN OUT ATTENTION TO LOW PRESSURE
PUSHING IN FROM THE WEST. THE LEADING EDGE OF MOISTURE, RIDING
OUT AHEAD OF THIS SYSTEM, COULD TOUCH OFF A WIDELY SCATTERED
SHOWER OR TWO LATE FRIDAY OR FRIDAY NIGHT, MAINLY IN OUR
NORTHERN AND WESTERN SECTIONS. THE BULK OF THE PRECIPITATION
WITH THE LOW WILL OCCUR LATE SATURDAY THROUGH SUNDAY AS THE
LOW TRACKS ACROSS THE MID ATLANTIC STATES JUST TO OUR SOUTH.
OUR VERY WARM STRETCH OF WEATHER WILL BE COMING TO AN END
SATURDAY AS SOUTHEAST WINDS USHER IN PLENTY OF LOW LEVEL
MOISTURE OFF THE ATLANTIC. HIGHS ON SATURDAY WILL ONLY BE ON
THE MID 50S TO MID 60S. SUNDAY COULD TURN OUT TO BE EVEN
COOLER WITH CLOUDS, RAIN AND EAST TO NORTHEAST WINDS. HIGHS
ON SUNDAY ARE FORECAST TO BE MAINLY IN THE 50S, EXCEPT
POSSIBLY INTO THE LOWER 60S OVER PORTIONS OF THE DELMARVA.
THE LOW WILL EXIT TO THE EAST LATER SUNDAY NIGHT AND MONDAY.
THIS WILL BRING AN END TO THE SHOWERS SUNDAY NIGHT, ALTHOUGH
ONE OR TWO COULD LINGER ALONG OUR SOUTHERN COASTAL AREAS UNTIL
SHORTLY AFTER DAYBREAK MONDAY. HIGH PRESSURE WILL THEN MOVE
INTO OUR AREA BRINGING A RETURN TO FAIR WEATHER LATER MONDAY
INTO WEDNESDAY. DAYTIME HIGHS WILL RUN SLIGHTLY ABOVE NORMAL
WITH READINGS IN THE MID 50S TO MID 60S MONDAY AND TUESDAY
AND MAINLY IN THE 60S ON WEDNESDAY. BY LATE WEDNESDAY, LOW
PRESSURE MOVING EAST ACROSS THE GREAT LAKES, AND IT`S
ASSOCIATED COLD FRONT, WILL BE APPROACHING OUR AREA. THIS COULD
TOUCH OFF A FEW SHOWERS, ESPECIALLY NORTH AND WEST.
&&
.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE CLOUDS MAY SCATTER FOR A FEW HOURS DURING THE EVENING, BUT
THEN WE FORECAST IFR CONDITIONS TO DEVELOP IN STRATUS AND FOG AND
TO LAST THROUGH DAYBREAK THURSDAY. VFR CONDITIONS SHOULD RETURN TO
THE TAF SITES DURING THE MORNING NORTHWEST, BY NOON OVER THE
DELAWARE RIVER VALLEY, AND DURING THE AFTERNOON SOUTHEAST. WINDS
THROUGH THE PERIOD WILL BE LIGHT. THEY SHOULD DEVELOP A SOUTHERLY
COMPONENT ON THURSDAY.
OUTLOOK...
COULD BE SOME LATE NIGHT AND EARLY MORNING FOG AGAIN THURSDAY NIGHT
INTO FRIDAY MORNING, BUT WITH THE FLOW BECOMING MORE SOUTHWESTERLY,
DON`T EXPECT CIGS/VSBYS TO BE AS LOW OR AS WIDESPREAD AS THE PAST
FEW NIGHTS. THE MAIN WEATHER MAKER DURING THIS TIME PERIOD WILL BE
THE AREA OF LOW PRESSURE THAT IS FORECAST TO PUSH IN FROM THE WEST.
IT IS EXPECTED TO TRACK ACROSS THE MID ATLANTIC REGION JUST TO OUR
SOUTH SATURDAY THROUGH SUNDAY AND THEN EXIT OFF TO THE EAST LATER
SUNDAY NIGHT AND MONDAY. THIS SYSTEM WILL BRING RAIN/SHOWERS/FOG
WITH REDUCED CIGS/VSBYS. VFR CONDITIONS WILL RETURN AS THE LOW
PULLS OFF TO THE EAST LATER SUNDAY NIGHT AND MONDAY.
&&
.MARINE...
SOUTHEAST TO SOUTH WINDS ARE FORECAST OVER THE WATERS THROUGH
THURSDAY. THEY SHOULD BE RATHER LIGHT, ALTHOUGH THEY MAY START TO
INCREASE INTO THE 10 TO 15 KNOT RANGE LATER THURSDAY. SEAS ALSO ARE
FORECAST TO BE BENIGN.
OUTLOOK...
WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW ADVISORY CRITERIA
THROUGH THE FIRST PART OF THE WEEKEND. SW WINDS THURSDAY NIGHT
WILL BRIEFLY SWING AROUND TO NW AND N FRIDAY MORNING, AS A WEAK
BACKDOOR FRONT DROPS ACROSS THE WATERS. WINDS WILL THEN BECOME
NE TO E FRIDAY AFTERNOON AND REMAIN E`RLY FRIDAY NIGHT INTO
SATURDAY NIGHT AS LOW PRESSURE MOVES IN FROM THE WEST. THE LOW
WILL INTENSIFY AS IT MOVES ACROSS THE MID ATLANTIC STATES
SATURDAY NIGHT AND SUNDAY. IT WILL CONTINUE TO INTENSIFY AS IT
MOVES OVER THE OCEAN WATERS AND EXITS OFF TO THE EAST SUNDAY NIGHT
AND MONDAY. THIS WILL CAUSE THE PRESSURE GRADIENT TO TIGHTEN,
WHICH, IN TURN, WILL CAUSE WINDS AND SEAS TO INCREASE. IT APPEARS
THAT ADVISORIES/WARNINGS WILL BE NECESSARY SUNDAY THROUGH MONDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RPW
NEAR TERM...DELISI/GIGI
SHORT TERM...DELISI
LONG TERM...RPW
AVIATION...DELISI/RPW
MARINE...DELISI/RPW
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
112 AM EDT WED MAR 21 2012
.SYNOPSIS...
WEAK COASTAL LOW PRESSURE NEAR NORFOLK VIRGINIA WILL DISSIPATE WEDNESDAY.
OTHERWISE...STRONG AND LARGE HIGH PRESSURE CENTERED JUST NORTH OF BERMUDA
WILL SHIFT SOUTHWARD THIS WEEKEND. THAT WILL PERMIT A COLD FRONT TO
SETTLE SOUTH INTO DELMARVA FRIDAY. THEREAFTER...PLAINS STATES LOW
PRESSURE TRACKS EASTWARD ALONG THAT FRONT TO NEAR DELMARVA SUNDAY
MORNING AND THEN OUT TO SEA SUNDAY EVENING. A SOUTHWARD EXTENSION
OF CANADIAN HIGH PRESSURE WILL ARRIVE ALONG THE EAST COAST EARLY
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE DENSE FOG ADVISORY WAS EXPANDED INTO THE REMAINDER OF SOUTHERN
NEW JERSEY...AS WELL AS DELAWARE. THE EXPANSION OF THE STRATUS IS
COMPLETE IN THESE AREAS. AS WAS THE CASE THIS TIME TUESDAY...THE
DENSE FOG IS FOLLOWING IN ABOUT 90 MINUTES AFTER THE ARRIVAL OF
THE STRATUS.
FOR NOW...THE PHILADELPHIA METRO AREA WAS LEFT OUT OF THE
ADVISORY...BUT IF THE TEND CONTINUES...THESE AREAS MAY BE PLACED
IN A DENSE FOG ADVISORY BEFORE 330 AM.
OTHERWISE, THE OFFSHORE SHOWERS ARE NOT MAKING MUCH LATITUDINAL
PROGRESS ABOVE 40N. HRRR STILL SUGGESTING THEY MIGHT MAKE IT INTO
THE EXTREME NE PART OF OUR CWA OVERNIGHT. CONFIDENCE STILL NOT
HIGH ENOUGH TO INCLUDE A LOW CHANCE. TEMPERATURES AND DEW POINTS
WERE TWEAKED CLOSER TO EACH OTHER, OVERALL NOT TOO MANY CHANGES
FROM THE TWO PREVIOUS ESTF FORECASTS. THE MESO LOW IS WEAKENING
IN DELMARVA, BUT THE WEAK ONSHORE FLOW SHOULD PERSIST OVERNIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THIS EVENING/...
LOOKS LIKE WEDNESDAY WILL BE VERY SIMILAR TO TODAY, WITH THE FOG
AND LOW CLOUDS GRADUALLY GIVING WAY TO PARTLY SUNNY SKIES. HIGH
PRESSURE OFF THE MID ATLANTIC COAST WILL ACTUALLY BE BUILDING INTO
A BERMUDA TYPE HIGH. LIGHT EAST TO SOUTHEAST WINDS WILL BECOME
SOUTHEAST TO SOUTH LATE IN THE DAY. TEMPERATURES WILL, ONCE AGAIN,
CLIMB INTO THE UPPER 60S AND 70S, WITH SLIGHTLY COOLER READINGS
ALONG COASTAL SECTIONS.
&&
.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
TEMPS: CONTINUED ABOVE NORMAL THROUGH THIS PERIOD THOUGH THE
EXCESSIVE 15 TO 25 DEGREE CALENDER DAY ABOVE NORMAL WARMTH OF THIS
WEEK WILL BE TEMPORARILY SUBDUED TO A FEW DEGREES ABOVE NORMAL
LATER THIS WEEKEND AND EARLY NEXT WEEK.
ALOFT: THE BROAD VERY STRONG RIDGE WITH ITS STRONGEST N-S AXIS JUST
WEST OF THE APPALACHIANS WILL BE CUT BACK ON ITS EASTERN ATLANTIC
FLANK BY A SERIES OF STRONG SHORT WAVES. TWO OF THOSE SHORT WAVES
MOVE SOUTHEASTWARD FROM THE VICINITY HUDSON BAY CANADA THROUGH THE
MARITIMES (1) THURSDAY FRIDAY AND (2) SUNDAY MONDAY...WHILE THE
HUGE SOUTHERN ROCKIES VORTEX SLOWLY WEAKENS AFTER ITS NORTHEASTWARD
EXIT OUT OF THE PLAINS STATES FRIDAY...SHOVING EASTWARD OFF THE
MID ATLANTIC COAST LATE SUNDAY.
SURFACE: STRONG HIGH PRESSURE JUST NORTH OF BERMUDA WILL SHIFT
SOUTHWARD THIS WEEKEND PERMITTING A CANADIAN COLD FRONT TO
SETTLE SOUTH INTO DELMARVA FRIDAY. THEREAFTER THE REMAINS OF THE
PLAINS STATES LOW TRACKS ALONG THE FRONT TO NEAR DELMARVA. THERE
MAY BE A BURST OF RELATIVELY CHILLY /NEAR NORMAL FOR THIS TIME OF
YEAR/ CANADIAN AIR IN ITS WAKE BY TUESDAY BUT THIS IS STILL IN
THE CONSIDERABLE UNCERTAINTY TIME FRAME.
THE DAILIES...
WEDNESDAY NIGHT THROUGH THURSDAY MORNING...BLENDED 12Z/20 NCEP MOS
GUIDANCE BENEATH THE RELATIVELY DRY ALOFT-STRONG RIDGE. LIGHT WIND.
FOG AND STRATUS...MAY NOT BE QUITE AS EXTENSIVE. THE REASONING...A
TENDENCY FOR A WLY BL WIND DEVELOPING EARLY THU. CALLED IT PATCHY
FOG FOR NOW AND MAY NOT HAVE ENOUGH FOG MENTIONED IN THE ZONES.
THURSDAY AFTERNOON THROUGH EARLY AFTERNOON FRIDAY...WIND TENDS TO
BECOME WESTERLY AND WARMER. A VERY GOOD CHANCE OF RECORD WARMTH ON
ONE OF THESE TWO DAYS...THURSDAY OR FRIDAY. CONTINUED RELATIVELY
DRY...IN PART BECAUSE OF THE NEAR 560 WARM THICKNESSES AND NO FOLIAGE
EVAPOTRANSPIRATION CONTRIBUTION. NCEP MOS POPS AGREE WITH THE DRY
PATTERN CONTINUING...DESPITE A CFP...POSSIBLY THRU THE WARMEST
TIME OF THE DAY. THERE IS SOME INSTABILITY AND WE MAY EVENTUALLY
NEED TO ADD A CHC OF A SHOWER OR TSTM FRIDAY. THE ECMWF HAS COOLER
MAX TEMPS ON THURSDAY THAN WHAT WE HAVE POSTED BUT THIS MAY IN
PART BE DUE TO ITS TRYING TO FCST A SHOWER DURING MIDDAY THURSDAY.
FOR NOW...WE ARE DRY AND WARMER THAN THE 12Z/20 ECMWF AND CLOSE TO
12/20 NCEP MEX GUIDANCE.
THIS WEEKEND...A RAINY PERIOD EXPECTED IN ASSOCIATION WITH THE
PLAINS STATES LOW TURNING EAST OR ESE TOWARD THE DELMARVA. THE
COMBINATION OF RAIN...AN ONSHORE MARITIME FLOW OFF THE COLDER SSTS
OF THE ATLANTIC /WHICH ARE VARIABLE BUT NEAR 10C/ AND A SWD
INJECTION OF COLDER AIR ASSOCIATED WITH CANADIAN HIGH PRESSURE
WILL ADD A COOLER FLAVOR COMPARED TO THE READINGS OF THIS
WORKWEEK. HPC GUIDANCE TEMPS ACCEPTED WHICH ARE COLDER THAN THE
12Z/20 GFS MEX GUIDANCE TEMPS. TODAY`S EC STICKS WITH THESE COLDER
TEMPS. OUR POPS ARE LIKELY FOR NOW... BUT UNDOUBTEDLY THERE HAS TO
BE INTERMITTENT RAIN FOR AT LEAST ONE OF THESE TWO WEEKEND DAYS
AND THERE MAY BE E QUITE A LOT. WOULD NOT SURPRISE TO SEE 2 INCH
AMTS...ESPECIALLY S NJ SE PA SWD CLOSER TO SLOW MOVING CONVECTIVE
ELEMENTS /THUNDER IS A POSSIBILITY THERE BUT NOT GRIDDED ATTM/.
EARLY NEXT WEEK...NCEP FAIR WX GUIDANCE ACCEPTED AS HIGH PRESSURE
APPROACHES WITH A DECENT BURST OF NLY FLOW CAA...STILL A LITTLE
ABOVE NORMAL BUT NOT NEARLY THE RECENT EXTREMES.
&&
.AVIATION /05Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
IFR CONDITIONS HAVE OVERSPREAD THE AREA AGAIN EARLY THIS MORNING...
AS MOISTURE SPREADS OUT WESTWARD UNDER THE LOW INVERSION IN PLACE.
LIFR CONDITIONS ARE FOLLOWING IN CLOSE BEHIND...AND MOST PLACES
(OUTSIDE OF KRDG AND KABE) ARE EXPECTED TO DROP TO LIFR IN FOG AFTER
0800 UTC...AND THIS IS EXPECTED TO LAST UNTIL ABOUT 1400 UTC.
THE DENSE FOG FOR KPHL AND OTHER METRO AIRPORTS IS NOT AS CLEAR CUT
AS IT WAS THIS TIME TUESDAY MORNING. THE IFR STRATUS IS IN...BUT IS
IT UNCLEAR IF ALL TERMINALS OUTSIDE OF KABE AND KRDG WILL GO LIFR.
THE FORECAST WILL BE FOR THIS TO OCCUR...AS THE LIGHT ONSHORE FLOW
IS STILL PRESENT. HOWEVER..THE FORECAST FOR THE KPHL METRO AIRPORTS
COULD END UP BEING A BIT PESSIMISTIC.
AFTER THE BREAKUP OF THE LIFR CONDITIONS AROUND 1400 UTC...THE
TRANSITION FROM IFR TO MVFR TO MVFR SHOULD OCCUR BY 1700 UTC AT ALL
LOCATIONS. AFTER THIS...VFR CONDITIONS ARE EXPECTED THOUGH SUNSET.
THERE IS THE POTENTIAL FOR WIDELY SCATTERED THUNDERSTORMS ACROSS
DELAWARE AND NORTHEAST MARYLAND THIS AFTERNOON AND EVENING...BUT THE
THREAT WAS NOT INCLUDED AT THE TERMINAL LOCATIONS.
AS THE LOW LEVEL FLOW BECOMES MORE SOUTH AND SOUTHWEST TONIGHT...THE
POTENTIAL FOR WIDESPREAD LIFR CONDITIONS IN FOG AND STRATUS APPEAR
TO BE LESS THAN PREVIOUS NIGHTS. THE STRATUS PROBABLY AFFECTS KACY
AND KMIV BEFORE 0400 UTC THURSDAY. AFTER THAT...IT IS STILL NOT
CLEAR JUST HOW FAR WEST THE STRATUS WILL GET. THIS POTENTIAL WILL BE
ADDRESSED IN THE 1200 UTC TERMINAL FORECASTS.
OUTLOOK...
THURSDAY...ANY MORNING IFR/LIFR GIVES WAY TO VFR CONDS AND WIND
TRENDING SW OR W IN THE AFTN G10-15 KTS.
FRIDAY...VFR. LIGHT WLY WIND AHEAD OF THE CFP THEN SHIFTING N OR E
FOLLOWING CFP. IFR STRATUS OR FOG MAY DEVELOP AT NIGHT IN THE LIGHT
ATLANTIC MARITIME EASTERLY FLOW. /LOW PROB A LINE OF SCT SHOWERS OR
TSTMS NEAR THE CF FRIDAY AFTN?/
THIS WEEKEND...MVFR/IFR CONDS DEVELOP...ESPECIALLY LATE SATURDAY INTO
SUNDAY IN SHOWERY RAINS WITH E FLOW SAT AND GUSTY N-NE FLOW 15 TO
25 KTS SUNDAY. SMALL CHC OF THUNDER S OF PHL.
&&
.MARINE...
A WEAK ONSHORE FLOW WILL PERSIST THROUGH WEDNESDAY WITH HIGH PRESSURE
CENTERED NEAR THE EASTERN TIP OF LONG ISLAND AND A VERY WEAK MESO
LOW JUST TO OUR SOUTH OFF THE DELMARVA COAST. WINDS AND SEAS WILL
REMAIN BELOW ADVISORY CRITERIA THROUGH THIS PERIOD. E WINDS 5 TO 10
KT WILL BECOME SE WEDNESDAY AND THEN TURN MORE S`RLY LATE IN THE DAY.
THE LOW LEVEL ONSHORE FLOW WILL BE VERY MOIST AND WILL ALLOW FOG TO
FORM OR MOVE BACK OVER OUR WATERS TONIGHT. SATELLITE PICTURES SHOW
SOME LOW CLOUDS AND FOG HANGING ALONG COASTAL SECTIONS THIS
AFTERNOON. ONCE THE DAYTIME HEATING ENDS, THIS AREA SHOULD EXPAND
RATHER QUICKLY. IF VSBYS DROP LOW ENOUGH OVER A WIDE PORTION OF
OUR AREA, A MARINE ADVISORY, OR AT THE VERY LEAST, A MARINE WEATHER
STATEMENT MAY BE NEEDED. ALL MARINERS SHOULD BE AWARE THAT VSBYS
COULD DROP QUICKLY IN AREAS OF FOG LATER TONIGHT. THE FOG WILL
LIFT WEDNESDAY, MUCH AS IT DID TODAY.
OUTLOOK...
NO HEADLINES ATTM FORESEEN THROUGH SATURDAY MORNING. LIGHT WINDS...
TENDING TO BE MAINLY SOUTH OR SE WITH A CFP OF SHIFTING WIND FRIDAY.
A STRONG PROBABILITY FOR STRONG SCA CONDITIONS LATE SATURDAY OR
MORE LIKELY SUNDAY IN STRENGTHENING NE FLOW SHIFTING N AND ATLC
SEAS BUILDING TO 6-8 FT.
&&
.CLIMATE...
RECORD MAXS NOT ALL OF THESE WILL BE AT RISK OF EXCEEDENCE.
TODAY`S REVIEW OF FCST MODEL GUIDANCE SUGGESTS FRIDAY THE MORE
LIKELY DAY FOR MANY RECORDS BUT...IF THERE IS NO RAIN ON THURSDAY AND
A DECENT WSW WIND WITH PLENTY OF SS...THERE WOULD ALSO BE A NUMBER
OF RECORDS ON THURSDAY AS WELL.
3/22 3/23
ACY 84-1948 79-1907 POR 1874
PHL 80-1948 78-1938/1907 POR 1872
ILG 82-1948 78-1994/1923 POR 1894
ABE 75-1929 73-1979/1923 POR 1922
TTN 79-1938 79-1938 POR 1865
GED 78-1955 80-2007 POR 1948
RDG 83-1938 79-1938 POR 1869
MPO 73-1938 70-1938 POR 1901
FOR THE THE FIRST 19 DAYS... DAILY MEAN TEMPS SO FAR ARE
KABE PLUS 10.7F
KACY PLUS 9.1F
KGED PLUS 9.2F
KPHL PLUS 8.9F
KRDG PLUS 10.2F
KTTN PLUS 11.0F
KILG PLUS 8.8F
KMPO PLUS 12.0F
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR NJZ012>027.
DE...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR DEZ001>004.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DRAG
NEAR TERM...GIGI/HAYES
SHORT TERM...RPW
LONG TERM...DRAG
AVIATION...DRAG/HAYES
MARINE...DRAG/RPW
CLIMATE...DRAG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1206 AM EDT WED MAR 21 2012
.SYNOPSIS...
WEAK COASTAL LOW PRESSURE NEAR NORFOLK VIRGINIA WILL DISSIPATE WEDNESDAY.
OTHERWISE...STRONG AND LARGE HIGH PRESSURE CENTERED JUST NORTH OF BERMUDA
WILL SHIFT SOUTHWARD THIS WEEKEND. THAT WILL PERMIT A COLD FRONT TO
SETTLE SOUTH INTO DELMARVA FRIDAY. THEREAFTER...PLAINS STATES LOW
PRESSURE TRACKS EASTWARD ALONG THAT FRONT TO NEAR DELMARVA SUNDAY
MORNING AND THEN OUT TO SEA SUNDAY EVENING. A SOUTHWARD EXTENSION
OF CANADIAN HIGH PRESSURE WILL ARRIVE ALONG THE EAST COAST EARLY
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE DENSE FOG ADVISORY WAS EXPANDED INTO THE REMAINDER OF SOUTHERN
NEW JERSEY...AS WELL AS DELAWARE. THE EXPANSION OF THE STRATUS IS
COMPLETE IN THESE AREAS. AS WAS THE CASE THIS TIME TUESDAY...THE
DENSE FOG IS FOLLOWING IN ABOUT 90 MINUTES AFTER THE ARRIVAL OF
THE STRATUS.
FOR NOW...THE PHILADELPHIA METRO AREA WAS LEFT OUT OF THE
ADVISORY...BUT IF THE TEND CONTINUES...THESE AREAS MAY BE PLACED
IN A DENSE FOG ADVISORY BEFORE 330 AM.
OTHERWISE, THE OFFSHORE SHOWERS ARE NOT MAKING MUCH LATITUDINAL
PROGRESS ABOVE 40N. HRRR STILL SUGGESTING THEY MIGHT MAKE IT INTO
THE EXTREME NE PART OF OUR CWA OVERNIGHT. CONFIDENCE STILL NOT
HIGH ENOUGH TO INCLUDE A LOW CHANCE. TEMPERATURES AND DEW POINTS
WERE TWEAKED CLOSER TO EACH OTHER, OVERALL NOT TOO MANY CHANGES
FROM THE TWO PREVIOUS ESTF FORECASTS. THE MESO LOW IS WEAKENING
IN DELMARVA, BUT THE WEAK ONSHORE FLOW SHOULD PERSIST OVERNIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 AM THURSDAY/...
LOOKS LIKE WEDNESDAY WILL BE VERY SIMILAR TO TODAY, WITH THE FOG
AND LOW CLOUDS GRADUALLY GIVING WAY TO PARTLY SUNNY SKIES. HIGH
PRESSURE OFF THE MID ATLANTIC COAST WILL ACTUALLY BE BUILDING INTO
A BERMUDA TYPE HIGH. LIGHT EAST TO SOUTHEAST WINDS WILL BECOME
SOUTHEAST TO SOUTH LATE IN THE DAY. TEMPERATURES WILL, ONCE AGAIN,
CLIMB INTO THE UPPER 60S AND 70S, WITH SLIGHTLY COOLER READINGS
ALONG COASTAL SECTIONS.
&&
.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
TEMPS: CONTINUED ABOVE NORMAL THROUGH THIS PERIOD THOUGH THE EXCESSIVE
15 TO 25 DEGREE CALENDER DAY ABOVE NORMAL WARMTH OF THIS WEEK WILL
BE TEMPORARILY SUBDUED TO A FEW DEGREES ABOVE NORMAL LATER THIS WEEKEND
AND EARLY NEXT WEEK.
ALOFT: THE BROAD VERY STRONG RIDGE WITH ITS STRONGEST N-S AXIS JUST
WEST OF THE APPALACHIANS WILL BE CUT BACK ON ITS EASTERN ATLANTIC
FLANK BY A SERIES OF STRONG SHORT WAVES. TWO OF THOSE SHORT WAVES
MOVE SOUTHEASTWARD FROM THE VICINITY HUDSON BAY CANADA THROUGH THE
MARITIMES (1) THURSDAY FRIDAY AND (2) SUNDAY MONDAY...WHILE THE
HUGE SOUTHERN ROCKIES VORTEX SLOWLY WEAKENS AFTER ITS NORTHEASTWARD
EXIT OUT OF THE PLAINS STATES FRIDAY...SHOVING EASTWARD OFF THE
MID ATLANTIC COAST LATE SUNDAY.
SURFACE: STRONG HIGH PRESSURE JUST NORTH OF BERMUDA WILL SHIFT
SOUTHWARD THIS WEEKEND PERMITTING A CANADIAN COLD FRONT TO
SETTLE SOUTH INTO DELMARVA FRIDAY. THEREAFTER THE REMAINS OF THE
PLAINS STATES LOW TRACKS ALONG THE FRONT TO NEAR DELMARVA. THERE
MAY BE A BURST OF RELATIVELY CHILLY /NEAR NORMAL FOR THIS TIME OF
YEAR/ CANADIAN AIR IN ITS WAKE BY TUESDAY BUT THIS IS STILL IN
THE CONSIDERABLE UNCERTAINTY TIME FRAME.
THE DAILIES...
WEDNESDAY NIGHT THROUGH THURSDAY MORNING...BLENDED 12Z/20 NCEP MOS
GUIDANCE BENEATH THE RELATIVELY DRY ALOFT-STRONG RIDGE. LIGHT WIND.
FOG AND STRATUS...MAY NOT BE QUITE AS EXTENSIVE. THE REASONING...A
TENDENCY FOR A WLY BL WIND DEVELOPING EARLY THU. CALLED IT PATCHY
FOG FOR NOW AND MAY NOT HAVE ENOUGH FOG MENTIONED IN THE ZONES.
THURSDAY AFTERNOON THROUGH EARLY AFTERNOON FRIDAY...WIND TENDS TO
BECOME WESTERLY AND WARMER. A VERY GOOD CHANCE OF RECORD WARMTH ON
ONE OF THESE TWO DAYS...THURSDAY OR FRIDAY. CONTINUED RELATIVELY
DRY...IN PART BECAUSE OF THE NEAR 560 WARM THICKNESSES AND NO FOLIAGE
EVAPOTRANSPIRATION CONTRIBUTION. NCEP MOS POPS AGREE WITH THE DRY
PATTERN CONTINUING...DESPITE A CFP...POSSIBLY THRU THE WARMEST
TIME OF THE DAY. THERE IS SOME INSTABILITY AND WE MAY EVENTUALLY
NEED TO ADD A CHC OF A SHOWER OR TSTM FRIDAY. THE ECMWF HAS COOLER
MAX TEMPS ON THURSDAY THAN WHAT WE HAVE POSTED BUT THIS MAY IN
PART BE DUE TO ITS TRYING TO FCST A SHOWER DURING MIDDAY THURSDAY.
FOR NOW...WE ARE DRY AND WARMER THAN THE 12Z/20 ECMWF AND CLOSE TO
12/20 NCEP MEX GUIDANCE.
THIS WEEKEND...A RAINY PERIOD EXPECTED IN ASSOCIATION WITH THE
PLAINS STATES LOW TURNING EAST OR ESE TOWARD THE DELMARVA. THE
COMBINATION OF RAIN...AN ONSHORE MARITIME FLOW OFF THE COLDER SSTS
OF THE ATLANTIC /WHICH ARE VARIABLE BUT NEAR 10C/ AND A SWD
INJECTION OF COLDER AIR ASSOCIATED WITH CANADIAN HIGH PRESSURE
WILL ADD A COOLER FLAVOR COMPARED TO THE READINGS OF THIS
WORKWEEK. HPC GUIDANCE TEMPS ACCEPTED WHICH ARE COLDER THAN THE
12Z/20 GFS MEX GUIDANCE TEMPS. TODAY`S EC STICKS WITH THESE COLDER
TEMPS. OUR POPS ARE LIKELY FOR NOW... BUT UNDOUBTEDLY THERE HAS TO
BE INTERMITTENT RAIN FOR AT LEAST ONE OF THESE TWO WEEKEND DAYS
AND THERE MAY BE E QUITE A LOT. WOULD NOT SURPRISE TO SEE 2 INCH
AMTS...ESPECIALLY S NJ SE PA SWD CLOSER TO SLOW MOVING CONVECTIVE
ELEMENTS /THUNDER IS A POSSIBILITY THERE BUT NOT GRIDDED ATTM/.
EARLY NEXT WEEK...NCEP FAIR WX GUIDANCE ACCEPTED AS HIGH PRESSURE
APPROACHES WITH A DECENT BURST OF NLY FLOW CAA...STILL A LITTLE
ABOVE NORMAL BUT NOT NEARLY THE RECENT EXTREMES.
&&
.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
WE ARE VERY CONFIDENT ABOUT IFR CONDITIONS SPREADING ACROSS THE
TERMINALS THIS EVENING AND ENVELOPING ALL BY 06Z OVERNIGHT. THE
CONFIDENCE FACTOR THOUGH IT MAY BE MORE STRATUS AND LESS DENSE FOG.
CLOUDS HAVE DEVELOPED NEAR THE COAST AND TIMING IN GENERAL WAS
ZERO TO TWO HOURS FASTER THAN LAST NIGHT. WE ARE FORECASTING
PREVAILING LIFR CONDITIONS TO OCCUR INTO WEDNESDAY MORNING. WE
FOLLOWED THE SAME IMPROVEMENT SCENARIO AS TODAY, VSBYS GO VFR
ABOUT AN HOUR BEFORE THE IFR STRATUS CIG DISSIPATES TO VFR
CONDITIONS. EXCEPTION IS WE HELD THE IFR STRATUS CIG LONGER INTO
EARLY WEDNESDAY AFTERNOON AT KACY. NOT CONFIDENT ABOUT KACY, BUT
ELSEWHERE FORECAST MOISTURE LEVELS ABOVE THE GROUND ARE MEAGER
ENOUGH THAT ONLY SCATTERED NON CIG VFR CUMULUS CLOUDS ARE EXPECTED
IN THE AFTERNOON.
WINDS WILL START LIGHT FROM THE EAST AND SOUTHEAST AND BECOME CALM
IN MOST PLACES. THE PREVAILING DIRECTION ON WEDNESDAY SHOULD BE
SOUTHEAST TO SOUTH. A SEA AND POSSIBLY BAY BREEZE FRONT SHOULD
FORM ON WEDNESDAY AFTERNOON WITH MORE DETAILS AS WE COME CLOSER IN
TIME.
OUTLOOK...
WEDNESDAY NIGHT...AT LEAST PATCHY IFR/LIFR STRATUS AND FOG ARE
PROBABLE AGAIN...ESPECIALLY LATE. LIGHT WIND TRENDING SW LATE.
THURSDAY...ANY MORNING IFR/LIFR GIVES WAY TO VFR CONDS AND WIND
TRENDING SW OR W IN THE AFTN G10-15 KTS.
FRIDAY...VFR. LIGHT WLY WIND AHEAD OF THE CFP THEN SHIFTING N OR E
FOLLOWING CFP. IFR STRATUS OR FOG MAY DEVELOP AT NIGHT IN THE LIGHT
ATLANTIC MARITIME EASTERLY FLOW. /LOW PROB A LINE OF SCT SHOWERS OR
TSTMS NEAR THE CF FRIDAY AFTN?/
THIS WEEKEND...MVFR/IFR CONDS DEVELOP...ESPECIALLY LATE SATURDAY INTO
SUNDAY IN SHOWERY RAINS WITH E FLOW SAT AND GUSTY N-NE FLOW 15 TO
25 KTS SUNDAY. SMALL CHC OF THUNDER S OF PHL.
&&
.MARINE...
A WEAK ONSHORE FLOW WILL PERSIST THROUGH WEDNESDAY WITH HIGH PRESSURE
CENTERED NEAR THE EASTERN TIP OF LONG ISLAND AND A VERY WEAK MESO
LOW JUST TO OUR SOUTH OFF THE DELMARVA COAST. WINDS AND SEAS WILL
REMAIN BELOW ADVISORY CRITERIA THROUGH THIS PERIOD. E WINDS 5 TO 10
KT WILL BECOME SE WEDNESDAY AND THEN TURN MORE S`RLY LATE IN THE DAY.
THE LOW LEVEL ONSHORE FLOW WILL BE VERY MOIST AND WILL ALLOW FOG TO
FORM OR MOVE BACK OVER OUR WATERS TONIGHT. SATELLITE PICTURES SHOW
SOME LOW CLOUDS AND FOG HANGING ALONG COASTAL SECTIONS THIS
AFTERNOON. ONCE THE DAYTIME HEATING ENDS, THIS AREA SHOULD EXPAND
RATHER QUICKLY. IF VSBYS DROP LOW ENOUGH OVER A WIDE PORTION OF
OUR AREA, A MARINE ADVISORY, OR AT THE VERY LEAST, A MARINE WEATHER
STATEMENT MAY BE NEEDED. ALL MARINERS SHOULD BE AWARE THAT VSBYS
COULD DROP QUICKLY IN AREAS OF FOG LATER TONIGHT. THE FOG WILL
LIFT WEDNESDAY, MUCH AS IT DID TODAY.
OUTLOOK...
NO HEADLINES ATTM FORESEEN THROUGH SATURDAY MORNING. LIGHT WINDS...
TENDING TO BE MAINLY SOUTH OR SE WITH A CFP OF SHIFTING WIND FRIDAY.
A STRONG PROBABILITY FOR STRONG SCA CONDITIONS LATE SATURDAY OR
MORE LIKELY SUNDAY IN STRENGTHENING NE FLOW SHIFTING N AND ATLC
SEAS BUILDING TO 6-8 FT.
&&
.CLIMATE...
RECORD MAXS NOT ALL OF THESE WILL BE AT RISK OF EXCEEDENCE.
TODAY`S REVIEW OF FCST MODEL GUIDANCE SUGGESTS FRIDAY THE MORE
LIKELY DAY FOR MANY RECORDS BUT...IF THERE IS NO RAIN ON THURSDAY AND
A DECENT WSW WIND WITH PLENTY OF SS...THERE WOULD ALSO BE A NUMBER
OF RECORDS ON THURSDAY AS WELL.
3/22 3/23
ACY 84-1948 79-1907 POR 1874
PHL 80-1948 78-1938/1907 POR 1872
ILG 82-1948 78-1994/1923 POR 1894
ABE 75-1929 73-1979/1923 POR 1922
TTN 79-1938 79-1938 POR 1865
GED 78-1955 80-2007 POR 1948
RDG 83-1938 79-1938 POR 1869
MPO 73-1938 70-1938 POR 1901
FOR THE THE FIRST 19 DAYS... DAILY MEAN TEMPS SO FAR ARE
KABE PLUS 10.7F
KACY PLUS 9.1F
KGED PLUS 9.2F
KPHL PLUS 8.9F
KRDG PLUS 10.2F
KTTN PLUS 11.0F
KILG PLUS 8.8F
KMPO PLUS 12.0F
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR NJZ012>027.
DE...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR DEZ001>004.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DRAG
NEAR TERM...GIGI/HAYES
SHORT TERM...RPW
LONG TERM...DRAG
AVIATION...DRAG/GIGI
MARINE...DRAG/RPW
CLIMATE...DRAG
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
157 PM EDT WED MAR 21 2012
.PREV DISCUSSION... /ISSUED 1156 AM EDT WED MAR 21 2012/
UPDATE...
GRIDS LOOK OKAY FOR THE MOST PART AT THIS TIME. HAVE MADE MINOR
ADJUSTMENTS TO HOURLY GRIDS JUST TO CATCH TRENDS BUT OVERALL NO
MAJOR CHANGES NEEDED. WILL HAVE TO KEEP AN EYE ON MAX TEMPS...
ADDITIONAL CLOUD COVER OUT THERE THIS MORNING HAS KEPT HOURLY
TEMPS BELOW THE FORECAST. EXPECT CLOUDS TO SCATTER OUT AND TEMPS
SHOULD CATCH UP BUT WILL MONITOR JUST IN CASE. POPS ACROSS EASTERN
ZONES STILL LOOK GOOD AS LOCAL WRF AND HRRR KEEPING MOST OF THE
CONVECTION ON THE EAST AND SOUTHEAST SIDE OF THE CWA.
TDP
PREV DISCUSSION... /ISSUED 743 AM EDT WED MAR 21 2012/
SHORT TERM /TODAY THROUGH THURSDAY NIGHT/...
/ISSUED AT 344 AM EDT WED MAR 21 2012/
LATEST SATELLITE IMAGERY SHOWS A DEEP CUT OFF LOW SPINNING OVER
TX...WHILE REGIONAL RADARS SHOW THE ASSOCIATED LINE OF CONVECTION
ACROSS CENTRAL AR AND LA. GFS AND NAM MODELS INITIALIZED WELL WITH
THESE FEATURES AT 06Z TONIGHT. BOTH MODELS ARE GOOD AGREEMENT ON
DRIFTING THE LOW OVER OK BY THIS EVENING WHERE IT SPINS THROUGH
THURSDAY...BEFORE LIFTING INTO AR/MO BY EARLY FRIDAY MORN. DURING
THIS TIME...THE ASSOCIATED LINE OF CONVECTION BARELY PUSHES INTO
WESTERN AL BY THURSDAY AFTERNOON. THE SLOW PROGRESSION SUGGEST ONE
MORE DAY OF SUMMER LIKE PATTERN HERE TODAY... BEFORE THE DEEPER
MOISTURE AND INCREASING RAIN CHANCES BEGIN TO PUSH INTO THE AREA ON
THURSDAY. A SUBTLE WEAKENING OF THE UPPER RIDGE AND THE INCREASE IN
HIGH CLOUDS WILL WARRANT GOING A COUPLE OF DEGREES COOLER WITH HIGHS
TODAY. A CONTINUED INCREASE IN LOW LEVEL MOISTURE... WEAKENING RIDGE
ALOFT AND 500-1000 J/KG AFTERNOON CAPE HAVE WARRANTED THE CONTINUED
MENTION OF ISOLATED THUNDER...BUT MAINLY OVER THE EASTERN ZONES
WHERE THE GREATER MOISTURE AND LOW LEVEL CONVERGENCE IS EXPECTED.
WILL SHOW A LOW CHANCE OF SHOWERS AND THUNDERSTORMS ALL ZONES ON
THURSDAY AS THE UPPER LOW DRAWS NEAR AND A DEEP SOUTHERLY FLOW
ADVECTS AMPLE GULF MOISTURE NORTHWARD. A PERSISTENT MID LEVEL RIDGE
INFLUENCE WILL CONTINUE TO HOLD CONVECTION WELL BELOW SEVERE LIMITS
TODAY. THEN EXPECT CLOUD COVER...COOLER HIGH TEMPS AND MODEST
INSTABILITIES TO HELP HOLD STORMS BELOW SEVERE LIMITS AGAIN ON
THURSDAY.
AS FOR TEMPS... CONTINUED TO TAKE A MAV/MET BLEND WITH A SLIGHT LEAN
TOWARD PERSISTENCE MINUS A DEGREE OR TWO. EXPECT TO EXTEND THE MARCH
CONSECUTIVE 80 DEGREE DAY RECORDS AT ATL AND AHN... BREAK THE RECORD
AT CSG...AND TIE THE RECORD AT MCN TODAY. INCREASING CLOUDS AND RAIN
CHANCES ON THURSDAY SHOULD HELP HOLD HIGHS MOSTLY IN THE 70S...BUT
CSG AND MCN AREAS WILL BE CLOSE TO THE 80 MARK AGAIN...AND COULD
BREAK THE MCN RECORD ON THU.
39
LONG TERM /FRIDAY THROUGH TUESDAY/...
/ISSUED AT 344 AM EDT WED MAR 21 2012/
DEEP...SLOW MOVING UPPER LOW FINALLY STARTING TO LIFT NORTHEAST BY
THE BEGINNING OF THE EXTENDED FORECAST PERIOD. AMPLE MOISTURE AND
DIFFLUENT UPPER FLOW FRIDAY FOR LIKELY POPS INTO THE NORTHWEST...
SPREADING SOUTHEAST ACROSS THE FORECAST AREA FRIDAY NIGHT AND
SATURDAY. UPPER LOW DIGS BACK TO THE SOUTHEAST ON SUNDAY IN RESPONSE
TO A BUILDING RIDGE OVER THE CENTRAL U.S. UPPER DYNAMICS AND BEST
MOISTURE ARE EAST OF GEORGIA BY THEN...BUT COOL POOL ALOFT ASSOCIATED
WITH THE UPPER LOW KEEPS ENOUGH INSTABILITY OVER THE REGION FOR AT
LEAST A SLIGHT CHANCE OF CONVECTION. BY MONDAY...AND FOR THE BALANCE
OF THE EXTENDED FORECAST PERIOD...THE CENTRAL U.S. UPPER RIDGE SHIFTS
EAST OVER THE REGION WITH DRY AND WARM WEATHER RETURNING.
20
CLIMATE...
RECORDS FOR 03-21
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 84 1948 41 1950 62 1994 21 1965
1935
1921
KATL 86 1907 37 1914 62 1994 21 1965
1921
1907
KCSG 85 1982 48 1998 62 1994 25 1956
KMCN 90 1907 45 1914 64 1921 27 1965
1907
&&
.AVIATION...
18Z UPDATE...
LINGERING MVFR CIGS WILL LIFT SOON WITH VFR CONDS EXPECTED
THROUGH THE EVENING. SCATTERED SHOWERS WITH A FEW ISOLATED
THUNDERSTORMS ARE POSSIBLE OVER SE AND E GA THIS AFTERNOON. MAIN
CONCERN WILL BE MVFR CIGS DEVELOPING 04-06Z...WITH IFR AND PSBL
LIFR CIGS AND FOG EXPTD EARLY THURSDAY MORNING AT ALL TAF SITES.
CONVECTION CHANCES ALSO INCREASE FROM WEST TO EAST AFTER 18Z
FRIDAY.
//ATL CONFIDENCE...18Z UPDATE...
HIGH ON WINDS...MEDIUM ON TIMING OF CONVECTION...VSBY AND IFR
CIGS.
08
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 82 59 79 59 / 20 20 30 20
ATLANTA 81 61 78 62 / 10 10 30 20
BLAIRSVILLE 77 54 74 56 / 20 20 30 20
CARTERSVILLE 82 56 79 58 / 10 10 30 30
COLUMBUS 82 62 81 62 / 10 10 30 20
GAINESVILLE 80 59 77 60 / 20 20 30 20
MACON 82 60 81 60 / 20 20 30 10
ROME 85 57 80 59 / 10 10 30 40
PEACHTREE CITY 80 57 78 58 / 10 10 30 20
VIDALIA 83 60 81 60 / 20 20 30 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1156 AM EDT WED MAR 21 2012
.UPDATE...
GRIDS LOOK OKAY FOR THE MOST PART AT THIS TIME. HAVE MADE MINOR
ADJUSTMENTS TO HOURLY GRIDS JUST TO CATCH TRENDS BUT OVERALL NO
MAJOR CHANGES NEEDED. WILL HAVE TO KEEP AN EYE ON MAX TEMPS...
ADDITIONAL CLOUD COVER OUT THERE THIS MORNING HAS KEPT HOURLY
TEMPS BELOW THE FORECAST. EXPECT CLOUDS TO SCATTER OUT AND TEMPS
SHOULD CATCH UP BUT WILL MONITOR JUST IN CASE. POPS ACROSS EASTERN
ZONES STILL LOOK GOOD AS LOCAL WRF AND HRRR KEEPING MOST OF THE
CONVECTION ON THE EAST AND SOUTHEAST SIDE OF THE CWA.
TDP
&&
.PREV DISCUSSION... /ISSUED 743 AM EDT WED MAR 21 2012/
SHORT TERM /TODAY THROUGH THURSDAY NIGHT/...
/ISSUED AT 344 AM EDT WED MAR 21 2012/
LATEST SATELLITE IMAGERY SHOWS A DEEP CUT OFF LOW SPINNING OVER
TX...WHILE REGIONAL RADARS SHOW THE ASSOCIATED LINE OF CONVECTION
ACROSS CENTRAL AR AND LA. GFS AND NAM MODELS INITIALIZED WELL WITH
THESE FEATURES AT 06Z TONIGHT. BOTH MODELS ARE GOOD AGREEMENT ON
DRIFTING THE LOW OVER OK BY THIS EVENING WHERE IT SPINS THROUGH
THURSDAY...BEFORE LIFTING INTO AR/MO BY EARLY FRIDAY MORN. DURING
THIS TIME...THE ASSOCIATED LINE OF CONVECTION BARELY PUSHES INTO
WESTERN AL BY THURSDAY AFTERNOON. THE SLOW PROGRESSION SUGGEST ONE
MORE DAY OF SUMMER LIKE PATTERN HERE TODAY... BEFORE THE DEEPER
MOISTURE AND INCREASING RAIN CHANCES BEGIN TO PUSH INTO THE AREA ON
THURSDAY. A SUBTLE WEAKENING OF THE UPPER RIDGE AND THE INCREASE IN
HIGH CLOUDS WILL WARRANT GOING A COUPLE OF DEGREES COOLER WITH HIGHS
TODAY. A CONTINUED INCREASE IN LOW LEVEL MOISTURE... WEAKENING RIDGE
ALOFT AND 500-1000 J/KG AFTERNOON CAPE HAVE WARRANTED THE CONTINUED
MENTION OF ISOLATED THUNDER...BUT MAINLY OVER THE EASTERN ZONES
WHERE THE GREATER MOISTURE AND LOW LEVEL CONVERGENCE IS EXPECTED.
WILL SHOW A LOW CHANCE OF SHOWERS AND THUNDERSTORMS ALL ZONES ON
THURSDAY AS THE UPPER LOW DRAWS NEAR AND A DEEP SOUTHERLY FLOW
ADVECTS AMPLE GULF MOISTURE NORTHWARD. A PERSISTENT MID LEVEL RIDGE
INFLUENCE WILL CONTINUE TO HOLD CONVECTION WELL BELOW SEVERE LIMITS
TODAY. THEN EXPECT CLOUD COVER...COOLER HIGH TEMPS AND MODEST
INSTABILITIES TO HELP HOLD STORMS BELOW SEVERE LIMITS AGAIN ON
THURSDAY.
AS FOR TEMPS... CONTINUED TO TAKE A MAV/MET BLEND WITH A SLIGHT LEAN
TOWARD PERSISTENCE MINUS A DEGREE OR TWO. EXPECT TO EXTEND THE MARCH
CONSECUTIVE 80 DEGREE DAY RECORDS AT ATL AND AHN... BREAK THE RECORD
AT CSG...AND TIE THE RECORD AT MCN TODAY. INCREASING CLOUDS AND RAIN
CHANCES ON THURSDAY SHOULD HELP HOLD HIGHS MOSTLY IN THE 70S...BUT
CSG AND MCN AREAS WILL BE CLOSE TO THE 80 MARK AGAIN...AND COULD
BREAK THE MCN RECORD ON THU.
39
LONG TERM /FRIDAY THROUGH TUESDAY/...
/ISSUED AT 344 AM EDT WED MAR 21 2012/
DEEP...SLOW MOVING UPPER LOW FINALLY STARTING TO LIFT NORTHEAST BY
THE BEGINNING OF THE EXTENDED FORECAST PERIOD. AMPLE MOISTURE AND
DIFFLUENT UPPER FLOW FRIDAY FOR LIKELY POPS INTO THE NORTHWEST...
SPREADING SOUTHEAST ACROSS THE FORECAST AREA FRIDAY NIGHT AND
SATURDAY. UPPER LOW DIGS BACK TO THE SOUTHEAST ON SUNDAY IN RESPONSE
TO A BUILDING RIDGE OVER THE CENTRAL U.S. UPPER DYNAMICS AND BEST
MOISTURE ARE EAST OF GEORGIA BY THEN...BUT COOL POOL ALOFT ASSOCIATED
WITH THE UPPER LOW KEEPS ENOUGH INSTABILITY OVER THE REGION FOR AT
LEAST A SLIGHT CHANCE OF CONVECTION. BY MONDAY...AND FOR THE BALANCE
OF THE EXTENDED FORECAST PERIOD...THE CENTRAL U.S. UPPER RIDGE SHIFTS
EAST OVER THE REGION WITH DRY AND WARM WEATHER RETURNING.
20
CLIMATE...
RECORDS FOR 03-21
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 84 1948 41 1950 62 1994 21 1965
1935
1921
KATL 86 1907 37 1914 62 1994 21 1965
1921
1907
KCSG 85 1982 48 1998 62 1994 25 1956
KMCN 90 1907 45 1914 64 1921 27 1965
1907
AVIATION...
12Z UPDATE...
LOW MVFR STRATUS DECK DEVELOPED OVER NE GA AND CONTINUES TO SPREAD
SW TOWARD ATL THIS MORNING. ATL OBS ALREADY SHOWING FEW015 AND
EXPECT THIS TO BECOME SCT BY 13-14Z IF NOT SOONER. STILL EXPECT THE
MVFR CIGS TO SCT BEFORE GETTING TO ATL AS SUFFICIENT DAYLIGHT SHOULD
HELP QUICKLY HELP TRANSITION THE ST TO CU BY 14-16Z. PREVAILING
WINDS WILL BE SE AROUND 9-11KTS WITH GUSTS TO AROUND 16-18KTS FROM
17-22Z. THE MAIN CONCERN IS EXPECTED MVFR CIGS DEVELOPING AT ALL TAF
SITES BY AROUND 06Z TONIGHT...THEN LOWERING TO IFR CIGS BY 09Z
THU...WITH SLOW IMPROVEMENT TO VFR CIGS THRU 16-17Z THU. EXPECT ANY
PRECIP THREAT ON THU TO HOLD OFF UNTIL AFTER 18Z AT THIS TIME.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ON CLOUDS THIS MORNING AND TONIGHT. HIGH
CONFIDENCE ON ALL OTHER ELEMENTS.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 82 59 79 59 / 20 20 30 20
ATLANTA 81 61 78 62 / 10 10 30 20
BLAIRSVILLE 77 54 74 56 / 20 20 30 20
CARTERSVILLE 82 56 79 58 / 10 10 30 30
COLUMBUS 82 62 81 62 / 10 10 30 20
GAINESVILLE 80 59 77 60 / 20 20 30 20
MACON 82 60 81 60 / 20 20 30 10
ROME 85 57 80 59 / 10 10 30 40
PEACHTREE CITY 80 57 78 58 / 10 10 30 20
VIDALIA 83 60 81 60 / 20 20 30 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
310 AM EDT WED MAR 21 2012
.SYNOPSIS...
LITTLE CHANGE THROUGH THURSDAY AS AN UPPER LEVEL RIDGE REMAINS
OVER THE REGION. THE RIDGE WILL BEGIN TO WEAKEN AND SHIFT EAST
FRIDAY. A FRONT WILL MOVE THROUGH THE REGION THIS WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
IMMEDIATE NEAR TERM CONCERN IS FOG POTENTIAL. PATCHY DENSE FOG
CURRENTLY DEVELOPING NEAR THE SOUTHERN TIER OF THE FA. WILL
MONITOR FOR POSSIBLE DENSE FOG ADVISORY.
OTHERWISE...LITTLE OVERALL CHANGE EXPECTED TODAY. WE WILL REMAIN
UNDER AN UPPER RIDGE...WITH THE RIDGE AXIS JUST TO OUR WEST.
MODELS INDICATE A WEAK UPPER IMPULSE MAY SET UP CONVECTION AGAIN
MAINLY JUST TO OUR NE. WITH WARM LAND TEMPS/COOL WATER TEMPS WITH
A SE GRADIENT FLOW...SIGNIFICANT SEA BREEZE EXPECTED. WRF MODEL
RUNS INDICATING SEA BREEZE CONVECTION DEVELOPING THIS AFTERNOON
AND MOVING INTO THE FA. WILL INDICATE MAINLY SHOWERS WITH A
SLIGHT CHANCE OF THUNDER. SEVERE NOT EXPECTED...AS FORECAST
SOUNDINGS INDICATE ONLY WEAK INSTABILITY AND WEAK SHEAR.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
LITTLE OVERALL CHANGE FOR THURSDAY AS WELL. UPPER RIDGE AXIS TO
REMAIN NEAR OR JUST WEST OF OUR REGION. AN UPPER LOW WILL SLOWLY
DRIFT SOUTH...ACROSS THE NC COAST AND OFFSHORE...REMAINING JUST
EAST OF OUR FA. SLIGHT CHANCE TO CHANCE POPS...FAVORING THE EAST
AND SOUTHERN FA AGAIN THURSDAY. SIGNIFICANT SEA BREEZE BOUNDARY
EXPECTED AGAIN.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
NO CHANGES MADE TO THE ONGOING FORECAST FOR THIS TIME PERIOD.
PREVIOUS DISCUSSION FOLLOWS.
MODELS REMAIN IN AGREEMENT THROUGH THE LONG TERM WITH THE MAIN
FOCUS BEING THE UPPER LEVEL CUT OFF LOW. SOME MODEL DIFFERENCES IN
TIMING AND TRACK PERSIST...HOWEVER THERE IS OVERALL AGREEMENT WITH
THE SYNOPTIC SITUATION THROUGH EARLY NEXT WEEK. UPPER LEVEL
BLOCKING PATTERN WILL CONTINUE THROUGH THE LONG TERM WITH A CUT
OFF LOW SLOWLY PROGRESSING THROUGH THE EASTERN US. BY EARLY NEXT
WEEK THE UPPER LEVEL PATTERN WILL BEGIN TO MODERATE...HOWEVER WILL
REMAIN HIGHLY AMPLIFIED.
ON FRIDAY THE UPPER LEVEL RIDGE WILL BEGIN BREAKING DOWN AS THE
UPPER LOW MOVES THROUGH ILLINOIS. A COLD FRONT WILL APPROACH FROM
THE WEST DURING THE DAY FRIDAY AND CROSS THE FORECAST AREA FRIDAY
NIGHT INTO SATURDAY. THE FRONT WILL SLOWLY MOVE OFFSHORE ON SATURDAY
AS THE UPPER LOW MOVES SOUTHEASTWARD REACHING KY/TN LATE SATURDAY
AFTERNOON. THE LOW WILL CROSS THE NC/VA AREA ON SUNDAY AND FINALLY
MOVE OFFSHORE SUNDAY NIGHT. HIGH PRESSURE ALONG WITH THE UPPER RIDGE
AND DRIER AIR WILL BEGIN BUILDING BACK INTO THE REGION ON MONDAY AND
RESIDE OVER THE AREA TUESDAY. TEMPERATURES THROUGH THE LONG TERM
WILL BE ABOVE NORMAL...WITH A SLIGHT COOLING TREND THROUGH THE
WEEKEND INTO EARLY NEXT WEEK.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
CAE RADAR SHOWING SOME SHOWERS TO NORTH ENTERING NORTHERN COUNTIES
EARLY THIS MORNING. THIS IS ASSOCIATED WITH A WEAK SHORT WAVE
DEPICTED BY THE RUC MODEL. RUC SHOWS SHORT WAVE DROPPING SOUTHWARD
THROUGH THE REGION THIS MORNING. SHOWERS APPEAR TO BE WEAKENING
AND DO NOT THINK THEY WILL HOLD TOGETHER AND AFFECT TAF SITES.
OTHERWISE...INCREASING LOW-LEVEL MOISTURE IN THE SOUTHEAST FLOW
PLUS DIURNAL COOLING WILL RESULT IN MVFR OR IFR FOG DURING THE
EARLY MORNING HOURS. MOST OF THE NAM AND GFS MOS PLUS GFS LAMP
INDICATE FOG. SREF PROBABILITIES OF FOG ARE ALSO SIGNIFICANT.
HEATING AND MIXING SHOULD RESULT IN VFR CONDITIONS AFTER 15Z.
HEATING IN ADDITION TO AN EXPECTED SEA BREEZE WILL HELP CAUSE
THUNDERSTORMS WEDNESDAY AFTERNOON. UNCERTAIN AS TO COVERAGE OF
CONVECTIVE ACTIVITY WITH SHORT WAVE TO SOUTH AND 40 KM NAM SHOWING
RIDGE TO NORTH EXTENDING SOUTHWARD INTO CENTRAL MIDLANDS INCLUDING
CAE AND CUB MAY LIMIT COVERAGE TO THE NORTH BUT SEA BREEZE TO
SOUTH MAY INCREASE COVERAGE THERE. DECIDED TO GO VFR BUT INCLUDE
SHOWER VCNTY REMARKS MOST TAF SITES THIS AFTERNOON AND EVENING.
WITH OGB BEING CLOSER AND BEING MORE AFFECTED BY SEA BREEZE...
DECIDED TO GO WITH TSTM VCNTY REMARK. AGAIN MAINLY VFR CONDITIONS
THROUGHOUT THE FORECAST AREA.
EXTENDED AVIATION OUTLOOK...HIGH PRESSURE CENTERED WELL OFF THE
SOUTHEAST COAST WILL DIRECT AN ONSHORE FLOW INTO THE AREA. LOW-LEVEL
MOISTURE ASSOCIATED WITH THIS FLOW MAY RESULT IN MAINLY LATE NIGHT
AND EARLY MORNING FOG THURSDAY AND FRIDAY. SCATTERED SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH A WEAK FRONTAL SYSTEM MAY BRING
RESTRICTIONS SATURDAY AND SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
133 AM EDT WED MAR 21 2012
.SYNOPSIS...
AN UPPER-LEVEL RIDGE WILL REMAIN OVER THE REGION THIS
WEEK...RESULTING IN CONTINUED ABOVE NORMAL TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
CONVECTION WINDING DOWN ACROSS THE CHARLOTTE METRO AREA AND LOOKS
LIKE PRECIPITATION WILL REMAIN NORTH OF THE NORTHERN MIDLANDS
BEFORE DISSIPATING. DO NOT EXPECT ADDITIONAL OVERNIGHT DEVELOPMENT
WITH THE LOSS OF HEATING AND WEAKENING INSTABILITY.
OVERNIGHT LOWS SHOULD FALL BACK INTO THE MID TO UPPER 50S AGAIN.
INCREASED LOW LEVEL MOISTURE FROM SOUTHEASTERLY FLOW TODAY MAY
RESULT IN SOME PATCHY FOG AROUND THE REGION WEDNESDAY MORNING AND
HAVE INCLUDED THAT IN THE FORECAST AFTER 2 AM.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
UPPER-LEVEL RIDGE WILL REMAIN JUST WEST OF THE FORECAST AREA ON
WEDNESDAY AS A WEAK DISTURBANCE MOVES SOUTHWARD ALONG THE COAST.
DISTURBANCE WILL STALL ALONG THE NC COAST WEDNESDAY NIGHT THEN
GRADUALLY TRACK OFFSHORE THURSDAY BEFORE ACCELERATING EASTWARD
THURSDAY NIGHT AS THE COLD FRONT APPROACHES FROM THE WEST. WITH
THE DISTURBANCE JUST NORTHEAST OF THE FORECAST AREA WILL KEEP
INCREASING CHANCES OF THUNDERSTORMS IN THE FORECAST FOR WEDNESDAY
AND THURSDAY. BEST CHANCE OF THUNDERSTORMS WILL BE OVER THE
NORTHERN AND EASTERN MIDLANDS WITH LOWER CHANCES OVER THE CSRA.
ALTHOUGH INSTABILITY WILL BE MODERATE THE CHANCE OF SEVERE
THUNDERSTORMS REMAINS LOW DUE TO WEAK MID-LEVEL LAPSE RATES AND
LIGHT WINDS ALOFT. TEMPERATURES THROUGH THE SHORT TERM WILL BE IN
THE UPPER 70S TO LOWER 80S FOR DAYTIME HIGHS WITH OVERNIGHT LOWS
IN THE MIDDLE TO UPPER 50S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
MODELS REMAIN IN AGREEMENT THROUGH THE LONG TERM WITH THE MAIN
FOCUS BEING THE UPPER LEVEL CUT OFF LOW. SOME MODEL DIFFERENCES IN
TIMING AND TRACK PERSIST...HOWEVER THERE IS OVERALL AGREEMENT WITH
THE SYNOPTIC SITUATION THROUGH EARLY NEXT WEEK. UPPER LEVEL
BLOCKING PATTERN WILL CONTINUE THROUGH THE LONG TERM WITH A CUT
OFF LOW SLOWLY PROGRESSING THROUGH THE EASTERN US. BY EARLY NEXT
WEEK THE UPPER LEVEL PATTERN WILL BEGIN TO MODERATE...HOWEVER WILL
REMAIN HIGHLY AMPLIFIED.
ON FRIDAY THE UPPER LEVEL RIDGE WILL BEGIN BREAKING DOWN AS THE
UPPER LOW MOVES THROUGH ILLINOIS. A COLD FRONT WILL APPROACH FROM
THE WEST DURING THE DAY FRIDAY AND CROSS THE FORECAST AREA FRIDAY
NIGHT INTO SATURDAY. THE FRONT WILL SLOWLY MOVE OFFSHORE ON SATURDAY
AS THE UPPER LOW MOVES SOUTHEASTWARD REACHING KY/TN LATE SATURDAY
AFTERNOON. THE LOW WILL CROSS THE NC/VA AREA ON SUNDAY AND FINALLY
MOVE OFFSHORE SUNDAY NIGHT. HIGH PRESSURE ALONG WITH THE UPPER RIDGE
AND DRIER AIR WILL BEGIN BUILDING BACK INTO THE REGION ON MONDAY AND
RESIDE OVER THE AREA TUESDAY. TEMPERATURES THROUGH THE LONG TERM
WILL BE ABOVE NORMAL...WITH A SLIGHT COOLING TREND THROUGH THE
WEEKEND INTO EARLY NEXT WEEK.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
CAE RADAR SHOWING SOME SHOWERS TO NORTH ENTERING NORTHERN COUNTIES
EARLY THIS MORNING. THIS IS ASSOCIATED WITH A WEAK SHORT WAVE
DEPICTED BY THE RUC MODEL. RUC SHOWS SHORT WAVE DROPPING SOUTHWARD
THROUGH THE REGION THIS MORNING. SHOWERS APPEAR TO BE WEAKENING
AND DO NOT THINK THEY WILL HOLD TOGETHER AND AFFECT TAF SITES.
OTHERWISE...INCREASING LOW-LEVEL MOISTURE IN THE SOUTHEAST FLOW
PLUS DIURNAL COOLING WILL RESULT IN MVFR OR IFR FOG DURING THE
EARLY MORNING HOURS. MOST OF THE NAM AND GFS MOS PLUS GFS LAMP
INDICATE FOG. SREF PROBABILITIES OF FOG ARE ALSO SIGNIFICANT.
HEATING AND MIXING SHOULD RESULT IN VFR CONDITIONS AFTER 15Z.
HEATING IN ADDITION TO AN EXPECTED SEA BREEZE WILL HELP CAUSE
THUNDERSTORMS WEDNESDAY AFTERNOON. UNCERTAIN AS TO COVERAGE OF
CONVECTIVE ACTIVITY WITH SHORT WAVE TO SOUTH AND 40 KM NAM SHOWING
RIDGE TO NORTH EXTENDING SOUTHWARD INTO CENTRAL MIDLANDS INCLUDING
CAE AND CUB MAY LIMIT COVERAGE TO THE NORTH BUT SEA BREEZE TO
SOUTH MAY INCREASE COVERAGE THERE. DECIDED TO GO VFR BUT INCLUDE
SHOWER VCNTY REMARKS MOST TAF SITES THIS AFTERNOON AND EVENING.
WITH OGB BEING CLOSER AND BEING MORE AFFECTED BY SEA BREEZE...
DECIDED TO GO WITH TSTM VCNTY REMARK. AGAIN MAINLY VFR CONDITIONS
THROUGHOUT THE FORECAST AREA.
EXTENDED AVIATION OUTLOOK...HIGH PRESSURE CENTERED WELL OFF THE
SOUTHEAST COAST WILL DIRECT AN ONSHORE FLOW INTO THE AREA. LOW-LEVEL
MOISTURE ASSOCIATED WITH THIS FLOW MAY RESULT IN MAINLY LATE NIGHT
AND EARLY MORNING FOG THURSDAY AND FRIDAY. SCATTERED SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH A WEAK FRONTAL SYSTEM MAY BRING
RESTRICTIONS SATURDAY AND SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...07
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
235 AM CDT WED MAR 21 2012
.DISCUSSION...
900 PM CDT
TEMPERATURES REMAIN VERY MILD ACROSS THE REGION THIS EVENING...ON
THE HEELS OF REACHING OR AT LEAST TYING A DAILY HIGH TEMPERATURE
RECORD FOR ONE WEEK STRAIGHT AT CHICAGO AND FOR SIX OF THOSE DAYS
AT ROCKFORD.
THE GOES WATER VAPOR LOOP THIS EVENING SHOWS THE WELL-DEFINED
CLOSED UPPER LOW SHIFTING EAST INTO THE RED RIVER VALLEY OF THE
SOUTH. VERY ANOMALOUS DUE SOUTH 60 TO 80 KT 500 MB FLOW IS EVIDENT
ON ALMOST ALL PROFILERS/RAOBS FROM EASTERN OK AND AR UP THROUGH
MN. MOIST PLUME WITHIN THIS IS STARTING TO SPREAD EAST SOME THIS
EVENING...WITH CLOUD TOP TEMPERATURES NOT WARMING MUCH ON IR INTO
WESTERN IL. RUC AND NAM 400 MB RH SOLUTIONS CONTINUE TO DRAW THIS
OVER AT LEAST THE WESTERN FORECAST AREA...WHICH MAKES SENSE. THIS
SHOULD THIN SOMEWHAT LATE TONIGHT AND WEDNESDAY MORNING AS SHORT
WAVE ENERGY ACROSS MO LIFTS DUE NORTH TOWARDS MN...ALLOWING THE
MOIST PUSH FROM THE WEST TO EASE. THE CLOUDS TONIGHT WILL HELP
TEMPERATURES FROM FALLING MUCH...ALLOWING FOR AN EASY BREAK OF THE
WARM LOWS FOR MARCH 20TH...AND SET THE STAGE FOR MARCH 21ST TO
POTENTIALLY FLIRT WITH ALL TIME WARM LOWS FOR THE MONTH OF MARCH
AT BOTH LONG TERM CLIMATE SITES /SEE CLIMO DISCUSSION BELOW/. THIS
IS ACCOUNTED FOR WELL IN THE GOING GRIDS. THE WARM MINIMUM VALUES
WILL ALLOW FOR A VERY MILD STARTING POINT WEDNESDAY...WHICH SHOULD
AGAIN SEE RECORD SMASHING WARMTH AS UPPER LEVEL HEIGHTS OVER THE
FORECAST AREA REMAIN STAGNANT THROUGH THE DAY.
MTF
//PREV DISCUSSION...
255 PM CDT
NEAR CLOUDLESS SKIES THIS AFTERNOON HAVE DEVELOPED OVER ALL OF
NORTHERN IL/NORTHWEST IN. THE ATMOSPHERIC RIVER CONTINUES TO BE
ORIENTED FROM THE WESTERN GULF OF MEXICO NORTH THROUGH EASTERN
TEXAS...KANSAS...BENDING NORTHEAST THROUGH WESTERN WISCONSIN. BROAD
500MB RIDGING CONTINUES TO HOLD THIS FEATURE WEST OF THE CWFA
TONIGHT...AND MOST LIKELY WILL PERSIST THROUGH WEDNESDAY. STRONG
MIXING HAS TAKEN PLACE THIS AFTERNOON ACROSS THE AREA...WITH BREEZY
WINDS TO 35 MPH. THIS HAS ALLOWED DECENT SUBSIDENCE AT THE SFC WITH
DEW POINTS PUSHING INTO THE 40S...AND AFTN RH VALUES INTO THE
MID/UPR 20 PERCENT RANGE. THUS A RED FLAG WARNING HAS BEEN HOISTED
TO ACCOUNT FOR THIS. THE EXPECTATION IS THAT ONCE BEYOND THE PEAK
HEATING LATE THIS AFTN/EARLY EVE...THE STRONG MIXING WILL BEGIN TO
RELAX AND RH VALUES WILL BEGIN TO RISE ABOVE RED FLAG CONDITIONS.
FLOW WILL REMAIN SOUTHERLY THROUGH THE OVERNIGHT PERIOD WITH MINIMAL
CLOUD SHIELDING. SO THE GREATEST CHALLENGE WILL BE HOW COOL TEMPS
WILL RADIATE TONIGHT. MOST GUIDANCE MEMBERS HAVE HOVERED AROUND
TEMPS IN THE UPR 50S/NEAR 60 DEG. THE CONCERN IS THAT GIVEN THE
SUPPRESSED DEW POINTS FROM THIS AFTN...OVERNIGHT LOWS MAY RADIATE
FURTHER. THE LARGEST LIMITING FACTOR WILL BE THAT WINDS SHUD REMAIN
LIGHT FROM THE SOUTH. THIS MAY CREATE ENOUGH FRICTION TO LIMIT HOW
MUCH COOLING ACTUALLY TAKES PLACE AT THE SFC...AND MAINTAIN SLIGHTLY
WARMER TEMPS.
FOR WEDNESDAY THE 850MB THERMAL RIDGE REMAINS OVERHEAD...WITH TEMPS
BTWN 12 AND 14 DEG C. THIS COMBINED WITH THE EXPECTED STRONG
SOUTHERLY FLOW...MINIMAL CLOUD COVER...VERY MILD OVERNIGHT
LOWS...WILL SET THE STAGE FOR RECORD BREAKING WARMTH YET AGAIN WITH
TEMPS INTO THE LOWER 80S. A FEW LOCATIONS COULD EASILY PUSH INTO THE
MID 80S...ESPECIALLY SOME OF THE FAVORED URBAN
AREAS AND PORTIONS OF CENTRAL IL. FURTHER WEST THE ATMOSPHERIC RIVER
WILL BEGIN TO DRIFT EAST...AS THE 500MB SHORTWAVE BEGINS TO BECOME
CUTOFF. HOWEVER...ENOUGH RIDGING INFLUENCE REMAINS OVER THE CWFA TO
LIMIT ANY PRECIP UNTIL CLOSER TO DAYBREAK THUR POSSIBLY LATE THUR
MORNING. AS CLOUDS SLOWLY INCREASE ALOFT WED NGT AND THICKEN...TEMPS
SHUD REMAIN MILD YET AGAIN. IT APPEARS LIKELY THAT TEMPS MAY NOT
DROP BELOW 60 DEG...WITH SEVERAL LOCATIONS REMAINING IN THE LOW/MID
60S.
CONFIDENCE...MEDIUM.
THURSDAY...
500MB SHORTWAVE BECOMES CUTOFF AND CONTINUES TO STEADILY DRIFT
NORTHEAST FROM THE SOUTHERN PLAINS TOWARDS THE WESTERN OHIO RIVER
VALLEY THUR. VARIOUS GUIDANCE MEMBERS HAVE SUGGESTED THAT PRECIP MAY
BE KNOCKING ON THE DOOR STEPS OF NORTHERN IL/NORTHWEST IN EARLY
THUR...WHILE A FEW OTHER MEMBERS HAVE HELD ONTO THE RIDGE INFLUENCE
AND DRY IDEA SLIGHTLY LONGER. CONFIDENCE IS THAT PRECIP SHUD ARRIVE
ARND DAYBREAK...AND HAVE ADJUSTED POPS ACCORDINGLY. IT APPEARS
ENOUGH INSTABILITY WILL EXIST ALOFT TO WARRANT THE MENTION OF
THUNDER...HOWEVER IT DOES NOT APPEAR TO BE WIDESPREAD. THUS HAVE
HELD ONTO A SLT CHC OF THUNDER. TEMPS WILL NOT WARM AS MUCH AS IN
PREVIOUS DAYS...HOLDING MAINLY IN THE UPR 60S TO MID 70S. IT MAY BE
POSSIBLE THAT FAR EASTERN PORTIONS OF THE CWFA COULD PUSH INTO THE
UPR 70S OR NEAR 80...BUT WILL HINGE UPON HOW THICK THE CLOUD SHIELD
ENDS UP BEING AT DAYBREAK.
POPS STILL LOOK LIKELY DURING MIDDAY THUR...THRU THE AFTN HOURS THEN
BEGIN TO FALL THROUGH THE EVENING TIMEFRAME. GUIDANCE HAS CONTINUED
TO SUGGEST A DRY SLOT ARRIVING ARND 00Z FRI..HOWEVER CONFIDENCE IS
LOW THAT THIS WILL BRING AN END TO THE PRECIP. THUS HAVE MAINTAINED
POPS THROUGHOUT THE OVERNIGHT HOURS INTO FRI.
CONFIDENCE...MEDIUM.
FRIDAY THROUGH MONDAY...
MINIMAL SPREAD AMONGST ENSEMBLE MEMBERS WITH REGARDS TO THE 500MB
WAVE PATTERN. CUTOFF LOW CONTINUES TO SHOW STEADY WEAKENING FOR THE
END OF THE WEEK...THEN EVENTUALLY BECOMES ABSORBED INTO THE RIDGE.
THE DOWNSTREAM TROUGH OVER THE ATLANTIC BEGINS TO WEAKEN...HOWEVER
IT APPEARS AN UPSTREAM TROUGH WILL BEGIN TO DEVELOP YET AGAIN ACROSS
THE SOUTHWEST CONUS. THIS CONTINUES TO SUGGEST THAT AFTER THE BRIEF
COOL DOWN INTO THE LOW/MID 60S FOR THE WEEKEND...TEMPS WILL BEGIN TO
RISE INTO THE UPR 60S/LOW 70S FOR THE FIRST PART OF NEXT WEEK. THIS
FEATURE HAS SOME VALIDITY TO IT GIVEN THE BUILDING MID-LVL RIDGE
ACROSS THE CENTRAL US DRIFTING EAST.
PRECIP CHCS WILL CONTINUE THRU SAT...THEN AS THE CUTOFF LOW DRIFTS
FURTHER EAST DRY AIR SHOULD RETURN FOR SUN/MON.
TEMPERATURE CONFIDENCE...HIGH.
PRECIPITATION CONFIDENCE...MEDIUM.
BEACHLER
&&
.CLIMATE...
900 PM CDT
CHICAGO ROCKFORD
HIGH WARM LOW HIGH WARM LOW
MAR 20: 53 (1918) 53 (1921)
MAR 21: 77 (1938) 54 (1918) 78 (1938) 53 (1948)
ALL TIME WARMEST FOR SO EARLY IN THE SEASON:
CHICAGO ROCKFORD
HIGH WARM LOW HIGH WARM LOW
82 (3/17/2012) 62 (3/13/1990) 82 (3/17/2012) 62 (3/19/2012)
ALL TIME RECORDS FOR MARCH:
CHICAGO ROCKFORD
HIGH WARM LOW HIGH WARM LOW
88 (3/29/2986) 66 (3/29/1998) 85 (3/29/1986) 63 (3/29/1998)
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SOUTHERLY WIND GUSTS AROUND 20 KT WEDNESDAY AFTERNOON.
KJB
//DISCUSSION...UPDATED 06Z...
A SLOW MOVING STORM SYSTEM CONTINUES TO MEANDER ACROSS THE CENTRAL
AND SOUTHERN PLAINS. SOUTHERLY WINDS AHEAD OF THIS SYSTEM WILL ONCE
AGAIN RESULT IN SOME GUST WINDS ACROSS THE TERMINALS THIS AFTERNOON.
HOWEVER...THE PRESSURE GRADIENT WILL BE WEAKER TODAY THAN IT WAS ON
TUESDAY. THEREFORE...WINDS SPEED SHOULD NOT BE A HIGH. CURRENTLY...I
AM EXPECTING SOME GUSTS IN THE UPPER TEENS TO THE LOW 20 KT RANGE.
OTHERWISE...ONLY SOME MID AND HIGH LEVEL CLOUDS ARE EXPECTED TO
IMPACT THE TERMINALS. ANY PRECIPITATION CHANCES WITH THIS STORM
SYSTEM LOOK TO HOLD OFF UNTIL THURSDAY.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...VFR...WITH INCREASING CHANCES FOR SHRA/TSRA THROUGH THE
EVENING...MVFR BECOMING POSSIBLE.
FRIDAY...OCCASIONAL SHRA WITH TSRA POSSIBLE EARLY...MVFR POSSIBLE AT
TIMES.
SATURDAY...CHANCE SHRA EARLY...OTHERWISE...VFR.
SUNDAY...VFR. WX NIL.
MONDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
234 AM CDT
ANOTHER DAY OF SOUTHERLY WINDS ARE EXPECTED ACROSS LAKE MICHIGAN
AHEAD OF LOW PRESSURE STILL MEANDERING ACROSS THE CENTRAL AND
SOUTHERN PLAINS. HOWEVER...WINDS WILL SWITCH OUT OF THE EAST LATE
TONIGHT INTO THURSDAY AS THE LOW ACROSS THE PLAINS SLOWLY LIFTS
NORTHEAST AND INTERACTS WITH HIGH PRESSURE BUILDING SOUTHEAST FROM
CANADA TO THE UPPER GREAT LAKES REGION. THIS WILL CONTINUE TO
DRIVE PRIMARILY EASTERLY FLOW ACROSS THE LAKE THROUGH FRIDAY BEFORE
THE WINDS BECOME MORE NORTHERLY ON SATURDAY AS THE SURFACE LOW MOVES
WITHIN THE VICINITY OF SOUTHERN LAKE MICHIGAN. THIS NORTHERLY FLOW
MAY CONTINUE INTO MONDAY. HOWEVER...THERE ARE DISCREPANCIES WITH HOW
QUICKLY AND THE EXACT SOUTHERN EXTENT OF ANOTHER AREA OF HIGH
PRESSURE THAT IS EXPECTED TO MOVE ACROSS SOUTHERN CANADA EARLY NEXT
WEEK. IF IT MOVES SLOWER...AS SOME OF THE MODELS ARE INDICATING
NORTHERLY WINDS WILL CONTINUE ON MONDAY BEFORE FINALLY BECOMING MORE
SOUTHERLY BY TUESDAY. UNCERTAINTY DURING THIS PERIOD REMAINS LOW.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1259 AM CDT WED MAR 21 2012
.DISCUSSION...
900 PM CDT
TEMPERATURES REMAIN VERY MILD ACROSS THE REGION THIS EVENING...ON
THE HEELS OF REACHING OR AT LEAST TYING A DAILY HIGH TEMPERATURE
RECORD FOR ONE WEEK STRAIGHT AT CHICAGO AND FOR SIX OF THOSE DAYS
AT ROCKFORD.
THE GOES WATER VAPOR LOOP THIS EVENING SHOWS THE WELL-DEFINED
CLOSED UPPER LOW SHIFTING EAST INTO THE RED RIVER VALLEY OF THE
SOUTH. VERY ANOMALOUS DUE SOUTH 60 TO 80 KT 500 MB FLOW IS EVIDENT
ON ALMOST ALL PROFILERS/RAOBS FROM EASTERN OK AND AR UP THROUGH
MN. MOIST PLUME WITHIN THIS IS STARTING TO SPREAD EAST SOME THIS
EVENING...WITH CLOUD TOP TEMPERATURES NOT WARMING MUCH ON IR INTO
WESTERN IL. RUC AND NAM 400 MB RH SOLUTIONS CONTINUE TO DRAW THIS
OVER AT LEAST THE WESTERN FORECAST AREA...WHICH MAKES SENSE. THIS
SHOULD THIN SOMEWHAT LATE TONIGHT AND WEDNESDAY MORNING AS SHORT
WAVE ENERGY ACROSS MO LIFTS DUE NORTH TOWARDS MN...ALLOWING THE
MOIST PUSH FROM THE WEST TO EASE. THE CLOUDS TONIGHT WILL HELP
TEMPERATURES FROM FALLING MUCH...ALLOWING FOR AN EASY BREAK OF THE
WARM LOWS FOR MARCH 20TH...AND SET THE STAGE FOR MARCH 21ST TO
POTENTIALLY FLIRT WITH ALL TIME WARM LOWS FOR THE MONTH OF MARCH
AT BOTH LONG TERM CLIMATE SITES /SEE CLIMO DISCUSSION BELOW/. THIS
IS ACCOUNTED FOR WELL IN THE GOING GRIDS. THE WARM MINIMUM VALUES
WILL ALLOW FOR A VERY MILD STARTING POINT WEDNESDAY...WHICH SHOULD
AGAIN SEE RECORD SMASHING WARMTH AS UPPER LEVEL HEIGHTS OVER THE
FORECAST AREA REMAIN STAGNANT THROUGH THE DAY.
MTF
//PREV DISCUSSION...
255 PM CDT
NEAR CLOUDLESS SKIES THIS AFTERNOON HAVE DEVELOPED OVER ALL OF
NORTHERN IL/NORTHWEST IN. THE ATMOSPHERIC RIVER CONTINUES TO BE
ORIENTED FROM THE WESTERN GULF OF MEXICO NORTH THROUGH EASTERN
TEXAS...KANSAS...BENDING NORTHEAST THROUGH WESTERN WISCONSIN. BROAD
500MB RIDGING CONTINUES TO HOLD THIS FEATURE WEST OF THE CWFA
TONIGHT...AND MOST LIKELY WILL PERSIST THROUGH WEDNESDAY. STRONG
MIXING HAS TAKEN PLACE THIS AFTERNOON ACROSS THE AREA...WITH BREEZY
WINDS TO 35 MPH. THIS HAS ALLOWED DECENT SUBSIDENCE AT THE SFC WITH
DEW POINTS PUSHING INTO THE 40S...AND AFTN RH VALUES INTO THE
MID/UPR 20 PERCENT RANGE. THUS A RED FLAG WARNING HAS BEEN HOISTED
TO ACCOUNT FOR THIS. THE EXPECTATION IS THAT ONCE BEYOND THE PEAK
HEATING LATE THIS AFTN/EARLY EVE...THE STRONG MIXING WILL BEGIN TO
RELAX AND RH VALUES WILL BEGIN TO RISE ABOVE RED FLAG CONDITIONS.
FLOW WILL REMAIN SOUTHERLY THROUGH THE OVERNIGHT PERIOD WITH MINIMAL
CLOUD SHIELDING. SO THE GREATEST CHALLENGE WILL BE HOW COOL TEMPS
WILL RADIATE TONIGHT. MOST GUIDANCE MEMBERS HAVE HOVERED AROUND
TEMPS IN THE UPR 50S/NEAR 60 DEG. THE CONCERN IS THAT GIVEN THE
SUPPRESSED DEW POINTS FROM THIS AFTN...OVERNIGHT LOWS MAY RADIATE
FURTHER. THE LARGEST LIMITING FACTOR WILL BE THAT WINDS SHUD REMAIN
LIGHT FROM THE SOUTH. THIS MAY CREATE ENOUGH FRICTION TO LIMIT HOW
MUCH COOLING ACTUALLY TAKES PLACE AT THE SFC...AND MAINTAIN SLIGHTLY
WARMER TEMPS.
FOR WEDNESDAY THE 850MB THERMAL RIDGE REMAINS OVERHEAD...WITH TEMPS
BTWN 12 AND 14 DEG C. THIS COMBINED WITH THE EXPECTED STRONG
SOUTHERLY FLOW...MINIMAL CLOUD COVER...VERY MILD OVERNIGHT
LOWS...WILL SET THE STAGE FOR RECORD BREAKING WARMTH YET AGAIN WITH
TEMPS INTO THE LOWER 80S. A FEW LOCATIONS COULD EASILY PUSH INTO THE
MID 80S...ESPECIALLY SOME OF THE FAVORED URBAN
AREAS AND PORTIONS OF CENTRAL IL. FURTHER WEST THE ATMOSPHERIC RIVER
WILL BEGIN TO DRIFT EAST...AS THE 500MB SHORTWAVE BEGINS TO BECOME
CUTOFF. HOWEVER...ENOUGH RIDGING INFLUENCE REMAINS OVER THE CWFA TO
LIMIT ANY PRECIP UNTIL CLOSER TO DAYBREAK THUR POSSIBLY LATE THUR
MORNING. AS CLOUDS SLOWLY INCREASE ALOFT WED NGT AND THICKEN...TEMPS
SHUD REMAIN MILD YET AGAIN. IT APPEARS LIKELY THAT TEMPS MAY NOT
DROP BELOW 60 DEG...WITH SEVERAL LOCATIONS REMAINING IN THE LOW/MID
60S.
CONFIDENCE...MEDIUM.
THURSDAY...
500MB SHORTWAVE BECOMES CUTOFF AND CONTINUES TO STEADILY DRIFT
NORTHEAST FROM THE SOUTHERN PLAINS TOWARDS THE WESTERN OHIO RIVER
VALLEY THUR. VARIOUS GUIDANCE MEMBERS HAVE SUGGESTED THAT PRECIP MAY
BE KNOCKING ON THE DOOR STEPS OF NORTHERN IL/NORTHWEST IN EARLY
THUR...WHILE A FEW OTHER MEMBERS HAVE HELD ONTO THE RIDGE INFLUENCE
AND DRY IDEA SLIGHTLY LONGER. CONFIDENCE IS THAT PRECIP SHUD ARRIVE
ARND DAYBREAK...AND HAVE ADJUSTED POPS ACCORDINGLY. IT APPEARS
ENOUGH INSTABILITY WILL EXIST ALOFT TO WARRANT THE MENTION OF
THUNDER...HOWEVER IT DOES NOT APPEAR TO BE WIDESPREAD. THUS HAVE
HELD ONTO A SLT CHC OF THUNDER. TEMPS WILL NOT WARM AS MUCH AS IN
PREVIOUS DAYS...HOLDING MAINLY IN THE UPR 60S TO MID 70S. IT MAY BE
POSSIBLE THAT FAR EASTERN PORTIONS OF THE CWFA COULD PUSH INTO THE
UPR 70S OR NEAR 80...BUT WILL HINGE UPON HOW THICK THE CLOUD SHIELD
ENDS UP BEING AT DAYBREAK.
POPS STILL LOOK LIKELY DURING MIDDAY THUR...THRU THE AFTN HOURS THEN
BEGIN TO FALL THROUGH THE EVENING TIMEFRAME. GUIDANCE HAS CONTINUED
TO SUGGEST A DRY SLOT ARRIVING ARND 00Z FRI..HOWEVER CONFIDENCE IS
LOW THAT THIS WILL BRING AN END TO THE PRECIP. THUS HAVE MAINTAINED
POPS THROUGHOUT THE OVERNIGHT HOURS INTO FRI.
CONFIDENCE...MEDIUM.
FRIDAY THROUGH MONDAY...
MINIMAL SPREAD AMONGST ENSEMBLE MEMBERS WITH REGARDS TO THE 500MB
WAVE PATTERN. CUTOFF LOW CONTINUES TO SHOW STEADY WEAKENING FOR THE
END OF THE WEEK...THEN EVENTUALLY BECOMES ABSORBED INTO THE RIDGE.
THE DOWNSTREAM TROUGH OVER THE ATLANTIC BEGINS TO WEAKEN...HOWEVER
IT APPEARS AN UPSTREAM TROUGH WILL BEGIN TO DEVELOP YET AGAIN ACROSS
THE SOUTHWEST CONUS. THIS CONTINUES TO SUGGEST THAT AFTER THE BRIEF
COOL DOWN INTO THE LOW/MID 60S FOR THE WEEKEND...TEMPS WILL BEGIN TO
RISE INTO THE UPR 60S/LOW 70S FOR THE FIRST PART OF NEXT WEEK. THIS
FEATURE HAS SOME VALIDITY TO IT GIVEN THE BUILDING MID-LVL RIDGE
ACROSS THE CENTRAL US DRIFTING EAST.
PRECIP CHCS WILL CONTINUE THRU SAT...THEN AS THE CUTOFF LOW DRIFTS
FURTHER EAST DRY AIR SHOULD RETURN FOR SUN/MON.
TEMPERATURE CONFIDENCE...HIGH.
PRECIPITATION CONFIDENCE...MEDIUM.
BEACHLER
&&
.CLIMATE...
900 PM CDT
CHICAGO ROCKFORD
HIGH WARM LOW HIGH WARM LOW
MAR 20: 53 (1918) 53 (1921)
MAR 21: 77 (1938) 54 (1918) 78 (1938) 53 (1948)
ALL TIME WARMEST FOR SO EARLY IN THE SEASON:
CHICAGO ROCKFORD
HIGH WARM LOW HIGH WARM LOW
82 (3/17/2012) 62 (3/13/1990) 82 (3/17/2012) 62 (3/19/2012)
ALL TIME RECORDS FOR MARCH:
CHICAGO ROCKFORD
HIGH WARM LOW HIGH WARM LOW
88 (3/29/2986) 66 (3/29/1998) 85 (3/29/1986) 63 (3/29/1998)
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SOUTHERLY WIND GUSTS AROUND 20 KT WEDNESDAY AFTERNOON.
KJB
//DISCUSSION...UPDATED 06Z...
A SLOW MOVING STORM SYSTEM CONTINUES TO MEANDER ACROSS THE CENTRAL
AND SOUTHERN PLAINS. SOUTHERLY WINDS AHEAD OF THIS SYSTEM WILL ONCE
AGAIN RESULT IN SOME GUST WINDS ACROSS THE TERMINALS THIS AFTERNOON.
HOWEVER...THE PRESSURE GRADIENT WILL BE WEAKER TODAY THAN IT WAS ON
TUESDAY. THEREFORE...WINDS SPEED SHOULD NOT BE A HIGH. CURRENTLY...I
AM EXPECTING SOME GUSTS IN THE UPPER TEENS TO THE LOW 20 KT RANGE.
OTHERWISE...ONLY SOME MID AND HIGH LEVEL CLOUDS ARE EXPECTED TO
IMPACT THE TERMINALS. ANY PRECIPITATION CHANCES WITH THIS STORM
SYSTEM LOOK TO HOLD OFF UNTIL THURSDAY.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...VFR...WITH INCREASING CHANCES FOR SHRA/TSRA THROUGH THE
EVENING...MVFR BECOMING POSSIBLE.
FRIDAY...OCCASIONAL SHRA WITH TSRA POSSIBLE EARLY...MVFR POSSIBLE AT
TIMES.
SATURDAY...CHANCE SHRA EARLY...OTHERWISE...VFR.
SUNDAY...VFR. WX NIL.
MONDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
239 PM...LITTLE CHANGE TO THE FORECAST IS EXPECTED OVER THE NEXT
24 HRS OR SO. LARGE HIGH PRESSURE ALONG THE EAST COAST WILL REMAIN
NEARLY STATIONARY THROUGH THURSDAY AND BEGIN TO WEAKEN FRIDAY AS
IT DRIFTS EAST OVER THE ATLANTIC. THE GRADIENT HAS TIGHTENED OVER
THE WESTERN LAKES TODAY AND DEEP MIXING HAS ALLOWED GUSTS INTO THE
30 KT RANGE ACROSS THE ILLINOIS AND INDIANA NEARSHORE WATERS.
HOWEVER...THE STABLE MARINE LAYER OVER THE COLD WATERS IS LIKELY
PREVENTING THESE STRONGER WINDS FROM MIXING TO THE SURFACE. THE
GRADIENT WEAKENS SOME TONIGHT BUT REMAINS STRONG INTO WEDNESDAY
AFTERNOON. AN AREA OF HIGH PRESSURE IS THEN EXPECTED TO DEVELOP
OVER THE UPPER MIDWEST AND NORTHERN GREAT LAKES WEDNESDAY NIGHT.
THIS HIGH WILL THEN BE ABSORBED BY STRONGER HIGH PRESSURE FURTHER
NORTH ACROSS HUDSON BAY. AS THIS OCCURS...THERE COULD BE A PERIOD
WHERE THE GRADIENT TIGHTENS ENOUGH FOR EASTERLY WINDS AS HIGH AS
30 KTS LATE THURSDAY NIGHT INTO FRIDAY OVER THE NORTH END OF THE
LAKE. THE GRADIENT THEN BECOMES FAIRLY WEAK AS BROAD WEAK LOW
PRESSURE MOVES ACROSS THE SOUTHERN LAKES REGION FRIDAY NIGHT INTO
SATURDAY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
748 PM EDT THU MAR 22 2012
.AVIATION.../00Z TAFS/
SCT SHOWERS AND ISOLATED TSTMS DEVELOPED ALONG DIFFUSE E-W ORIENTED
BOUNDARY AND WK INSTABILITY OVER NRN INDIANA/NW OH THIS AFTN.
GIVEN THE WK FORCING/INSTABILITY AVAILABLE... EXPECT THIS
CONVECTION TO DISSIPATE WITH LOSS OF HEATING EARLY THIS EVENING
AND PRBLY HAVE LITTLE OR NO IMPACT ON THE TERMINALS. VERTICALLY
STACKED LOW OVER SE KS EXPECTED TO LIFT NE TO THE MID MS VALLEY BY
00Z SAT. NRN PORTION OF BAND OF SHOWERS ALONG OCCLUDING SFC CDFNT
AND MID LEVEL THETA-E RIDGE WHICH EXTENDED FROM ALABAMA THROUGH
IL WAS DISSIPATING THIS EVE AS IT LIFTS NE ACROSS IL... HOWEVER A
NEW BAND WAS FORMING FARTHER SW CLOSER TO LOW WHERE MID LEVEL
LAPSE RATES MORE FAVORABLE FROM WRN TN NNW TO WEST CENTRAL IL.
LATEST MODELS SUGGEST THE NEW BAND OF SHOWERS WILL MOVE NE TONIGHT
AND ACROSS NRN INDIANA FRIDAY MORNING WITH LOWER VFR CIGS/VSBYS
AND PSBLY A PERIOD OF MVFR ACCOMPANYING THE BAND. DRIER AIR WILL
OVERSPREAD THE AREA IN THE AFTN BUT COLDER TEMPS ALOFT AND A
SECONDARY WIND SHIFT ROTATING AROUND THE LOW MOVG NE TOWARD THE
AREA SHOULD RESULT IN DESTABILIZATION AND PRBLY SCT TSRA. POINT
PROB OF TS OCCURRENCE AT TERMINALS FRI AFTN STILL LOW SO LEFT
MENTION OUT OF TAFS ATTM.
&&
.UPDATE...
WILL BE UPDATING AROUND 00Z TO REMOVE LATE AFTN WORDING FROM ZFP.
AS MENTIONED IN AVIATION SECTION... APPEARS INITIAL SHOWER BAND
ASSOCIATED WITH STACKED LOW TO OUR SW WILL LARGELY DISSIPATE
BEFORE REACHING OUR AREA... THUS EXPECTING SCT SHOWERS/ISOLATED
TSTMS TO DIMINISH OVER THE AREA THIS EVE WITH MAIN ROUND OF MORE
WIDESPREAD SHOWERS ASSOCIATED WITH OCCLUDING CDFNT PUSHED BACK
ABOUT 6HRS TO LATE TONIGHT INTO FRI.
&&
.PREV DISCUSSION... /ISSUED 334 PM EDT THU MAR 22 2012/
SHORT TERM.../TONIGHT THROUGH FRIDAY NIGHT/
MOSTLY SUNNY TO SUNNY SKIES HAS ALLOWED TEMPS TO CLIMB INTO THE
UPPER 70S TO LOWER 80S ONCE AGAIN ACROSS THE AREA. LARGE UPPER LOW
THAT HAS BEEN RESPONSIBLE IN PART FOR THE MASSIVE WARMTH WAS
BEGINNING ITS TREK TOWARDS THE OHIO VALLEY. A BAND OF PRECIPITATION
EXTENDED FROM THE GULF STATES INTO PORTIONS OF EASTERN IOWA. MODELS
HAVE BEEN STRUGGLING TO DETERMINE THE TIMING OF THIS BAND SHIFTING
NORTHEAST AND IMPACTING THE AREA. SEVERAL OF THE HRRR RUNS DEPICTED
DEVELOPMENT OF WIDELY SCT TO SCT SHOWERS AND A FEW STORMS MID
AFTERNOON INTO EARLY EVENING. ACCAS FIELD HAS QUICKLY FORMED NE OF
THE MAIN BAND OF PRECIP AND CONVECTION HAS NOW BEGAN TO FIRE FROM NE
ILLINOIS INTO WHITE COUNTY AND TOWARDS INDY. IN ADDITION...CU FIELD
EXPANDING ACROSS SOUTHERN LWR MICHIGAN ALONG AND IN ADVANCE OF LAKE
BREEZE WHICH HAS WORKED WELL INLAND WITH ONE SHOWER NOTED OVER
HILLSDALE COUNTY. HAVE OPTED FOR PRE 1ST PERIOD SLGT CHC/CHC WITH
HIGHEST IN SW AREAS TO COVER TRENDS. BAND OF PRECIP SHOULD BEGIN TO
WORK CLOSER TO THE AREA LATER THIS EVENING INTO THE OVERNIGHT HOURS
ALLOWING FOR INCREASING CHANCES FOR SHOWERS AND MAYBE AN EVENING
STORM. HAVE TRIED TO ADD SOME TIMING DETAIL INTO THE OVERNIGHT HOURS
AND WENT CATEGORICAL LATER TONIGHT IN SW AREAS. CLOUD COVER AND
PRECIP WILL KEEP TEMPS AOA 60 FOR OVERNIGHT LOWS.
UPPER LOW WILL APPROACH THE OHIO RIVER FRI/FRI NGT. LARGE DRY SLOW
NOTED BEHIND BAND OF SHOWERS AND AHEAD OF THE MAIN UPPER LOW. TIMING
OF THIS WILL BE CRUCIAL TO CONVECTIVE DEVELOPMENT FRI AFTN/EVE AND
ALSO SEVERE POTENTIAL. TRENDS WOULD SUGGEST THAT CLEARING WILL
ARRIVE DURING THE MORNING FROM SW TO NE...ALLOWING TEMPS TO JUMP
INTO THE 70S PRIOR TO ARRIVAL OF SERIES OF WAVES WHICH WILL MOVE
AROUND THE LOW AND HELP EXPAND COVERAGE OF SHOWERS AND STORMS.
SWODY2 HAS SOUTHERN HALF OR SO OF AREA IN SLGT RISK. RISK FOR SEVERE
MAY EXTEND ACROSS ENTIRE AREA DEPENDING ON TIMING OF CLEARING AND
AMOUNT OF HEATING. LEFT LIKELY POPS ALONE FOR FRI MORNING WITH
POTENTIAL FOR DRY PERIOD THAT WILL NEED TO BE BETTER TIMED OUT WITH
THE OVERNIGHT PACKAGE. SEVERAL OFFICES HAVE INCREASED TO HIGH LIKELY
OR LOW END CAT POPS FRI AFTERNOON AND GIVEN SEVERAL SIGNALS IN
MODELS AND RECENT TRENDS...HAVE FOLLOWED SUIT AND INCREASED TO CAT
POPS NE HALF IN THE AFTERNOON.
FRIDAY NIGHT PRECIP WILL STILL LINGER IN THE EVENING SO HAVE KEPT
LIKELY POPS NE TRENDING TO CHC OVERNIGHT. LOWS WILL DROP BACK INTO
THE LOW TO MID 50S.
LONG TERM...
RETURN TO MORE SEASONABLE WEATHER STILL EXPECTED BEGINNING SATURDAY.
TEMPS STILL EXPECTED TO BE ABOVE NORMAL BUT IT WILL CERTAINLY FEEL
MORE LIKE LATE MARCH THAN LATE MAY.
UPPER LEVEL LOW WILL BE SLOWLY MOVING BY TO OUR SOUTH ON SATURDAY
WITH PLENTY OF WRAP AROUND MOISTURE AND WEAK LIFT. EXPECT A CLOUDY
DAY WITH SCATTERED SHOWERS. ENOUGH INSTABILITY IN AFTERNOON FOR SOME
THUNDERSTORM DEVELOPMENT SO LEFT SLIGHT CHANCE MENTION IN FOR THAT.
AS MENTIONED YESTERDAY...SYNOPTIC PATTERN STILL FAVORABLE FOR WEAK
CLOSED LOW FUNNEL CLOUDS...WHICH RARELY TOUCHDOWN BUT DO DEVELOP IN
THIS PATTERN.
UPPER LOW DRIFTS SOUTHEAST ON SUNDAY WITH DRIER AND COOLER AIR
MOVING IN. THIS HIGH WILL SETTLE INTO MICHIGAN MONDAY WITH COOL
EASTERLY FLOW OVER OUR AREA. MODELS HAVE BEEN TRENDING COOLER MONDAY
NIGHT WITH SURFACE RIDGE NOSING INTO NORTHEAST AREAS. HAVE CONTINUED
TREND OF GRADUALLY LOWERING TEMPS WITH LOWS NOW INTO MIDDLE 40S
SOUTHWEST TO MID 30S NORTHEAST. PATCHY FROST BECOMING MORE PLAUSIBLE
NORTHEAST IF WINDS DECOUPLE AND SKIES REMAIN CLEAR. RETURN FLOW
LOOKS TO QUICKLY SETUP EARLY TUESDAY AND THIS MAY HELP INCREASE
WINDS TUESDAY MORNING. MUCH TOO EARLY AND TOO MUCH UNCERTAINTY FOR
ANY INCLUSION OF FROST INTO FORECAST BUT CERTAINLY WORTH WATCHING
GIVEN THE SUSCEPTIBLE STATE OF MOST VEGETATION.
BRIEF WARMUP THROUGH WEDNESDAY BEFORE NEXT FRONT PUSHES THROUGH
BRINGING RAIN CHANCES BACK TO THE AREA. ACCEPTED ALLBLEND POPS FOR
THIS PERIOD WITH MID CHANCE RANGE AND STILL ISSUES WITH TIMING OF
BEST LIFT THROUGH THE AREA.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...FISHER
LONG TERM...LASHLEY
AVIATION/UPDATE...JT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
935 PM MDT THU MAR 22 2012
.UPDATE...
ISSUED AT 932 PM MDT THU MAR 22 2012
NUDGED POPS UP TO CHANCE CATEGORY ALONG AND WEST OF THE CO/KS
STATE LINE...MAINLY NORTH OF THE INTERSTATE...PER RADAR IMAGES
AND LATEST HRRR WHICH HAS A GOOD HANDLE ON CURRENT LOCATION OF
PRECIPITATION. NO OTHER CHANGES MADE.
UPDATE ISSUED AT 830 PM MDT THU MAR 22 2012
UPDATED TONIGHT THROUGH FRIDAY PERIODS. MAIN ADJUSTMENT WAS TO
INCREASE CLOUD COVER AROUND AN UPPER LOW PRESSURE CENTER CURRENTLY
OVER NORTH CENTRAL OKLAHOMA. AS THIS LOW MOVES EAST-NORTHEAST
TOWARD SOUTHERN MISSOURI FRIDAY CONSIDERABLE WRAPAROUND
CLOUDINESS WILL IMPACT THE WESTERN 1/2-1/3 OF THE AREA THROUGH
FRIDAY MORNING BEFORE DECREASING IN COVERAGE DURING THE AFTERNOON
AS AVAILABLE MOISTURE DECREASES.
AT 0230Z RADAR STILL SHOWING A FEW ECHOES ACROSS FAR WESTERN YUMA
AND KIT CARSON COUNTIES WHERE SOME LIGHT RAIN SHOWERS ARE FALLING.
THIS AREA OF PRECIPITATION CONTINUES TO SLOWLY LOSE ITS INTENSITY
AND AM THINKING THAT BY 06Z OR 09Z AT THE LATEST IT SHOULD BE WEAK
ENOUGH TO REMOVE POP MENTION.
NO CHANGES MADE TO THE FOG FORECAST EARLY FRIDAY MORNING THROUGH
MID MORNING. WINDS LIGHT THROUGH THE NEXT 36 HOURS OR SO. HIGH
TEMPERATURES STILL LOOK TO WARM CLOSE TO 70 DEGREES FOR MANY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 232 PM MDT THU MAR 22 2012
VISIBLE SATELLITE IMAGERY SHOWS CENTER OF LOW JUST SOUTHEAST OF
KP28. A BAND OF LIGHT SHOWERS ON THE NORTHWEST SIDE OF LOW WILL
PERSIST ACROSS THE EASTERN COLORADO COUNTIES THROUGH THE EVENING. AS
THE LOW SLOWLY MOVES EAST...MOISTURE ADVECTION/SHOWERS WILL END. LOW
WILL BE FAR ENOUGH EAST BY 12Z FRIDAY THAT CLOUDS WILL BE ALSO
DECREASE. HOWEVER...THE BOUNDARY LAYER IS QUITE MOIST AFTER
WIDESPREAD RAIN LAST NIGHT...SO AS CLEARING/SURFACE COOLING TAKES
PLACE...FOG WILL FORM. HARD TO PINPOINT EXACTLY WHERE FOG IS MOST
LIKELY TO DEVELOP...BUT WILL BEGIN BY INTRODUCING IT ACROSS THE
WESTERN HALF OF FORECAST AREA AROUND 08Z. EXPECT TEMPERATURES TO
DROP INTO THE MID 30S MOST AREAS TONIGHT.
MODELS AGREE THAT 500 MB RIDGE WILL BUILD OVER THE HIGH PLAINS
FRIDAY AFTERNOON. WARM AIR ADVECTION WILL BEGIN AFTER 18Z...WITH 850
MB TEMPERATURES REACHING 16-18 DEGREES CELSIUS. THUS...EXPECT
MAXIMUM TEMPERATURES TO REACH INTO THE UPPER 60S UNDER MOSTLY SUNNY
SKIES. THERE MAY BE FOG AGAIN FRIDAY NIGHT...BUT WILL SEE HOW FOG
FORMS TONIGHT BEFORE INTRODUCING IT AGAIN.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 232 PM MDT THU MAR 22 2012
A HIGHLY AMPLIFIED RIDGE WILL BE IN PLACE ACROSS THE CENTRAL US
SATURDAY THROUGH MONDAY WITH VERY WARM TEMPERATURES AND DRY
CONDITIONS EXPECTED. HIGH TEMPERATURES WILL GENERALLY RANGE
FROM THE UPPER 70S TO LOW 80S...WITH AFTERNOON TEMPERATURES POSSIBLY
WARMING INTO THE MIDDLE 80S ON MONDAY.
BY MONDAY NIGHT A SHORTWAVE TROUGH WILL PASS ACROSS THE
NORTHERN PLAINS...WITH AN ASSOCIATED COLD FRONT DROPPING SOUTH OVER
THE CWA LATE MONDAY NIGHT. WITH A DRY LINE LINGERING OVER THE CWA AND
DECENT INSTABILITY EAST OF THIS FEATURE MONDAY AFTERNOON THROUGH
MONDAY NIGHT...A FEW THUNDERSTORMS COULDNT BE RULED OUT OVER EASTERN
LOCATIONS. I STILL HAVE CONCERNS THAT A STRONG CAP IN PLACE ACROSS
OUR CWA WILL LIMIT CONVECTIVE POTENTIAL...AND THE OVERALL TREND WITH
GUIDANCE HAS BEEN TO PUSH THE BEST CHANCES FURTHER EAST. OVERALL THE
SYNOPTIC PATTERN HAS BEEN FAIRLY CONSISTENT...SO I DECIDED TO KEEP
SLIGHT CHANCE POPS IN THE EXTREME EASTERN PART OF OUR CWA FOR
ANOTHER FORECAST CYCLE. IF CURRENT TRENDS HOLD THESE POPS COULD
PROBABLY BE REMOVED.
TUESDAY THROUGH THURSDAY...A MORE PROGRESSIVE PATTERN SETS IN BY THE
MIDDLE OF NEXT WEEK. HOWEVER...THE MAIN STORM TRACK REMAINS FAR TO
THE NORTH...SO DRY CONDITIONS SHOULD CONTINUE ACROSS THE
TRI-STATE REGION. TEMPERATURES OVER THE CWA WILL BE SLIGHTLY COOLER
AFTER THE RIDGE BREAKS DOWN MONDAY NIGHT...HOWEVER THEY WILL REMAIN
ABOVE NORMAL WITH HIGHS GENERALLY IN THE UPPER 60S/LOW 70S ACROSS
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 505 PM MDT THU MAR 22 2012
VFR EXPECTED THROUGH THE PERIOD AT KGLD AND KMCK. VARIABLE WINDS
6 KTS OR LESS EXPECTED ALONG WITH SOME CU/STRATO-CU. MAY SEE SOME
FOG EARLY FRIDAY MORNING GIVEN THE LIGHT WINDS AND RECENT
RAINFALL.
&&
.FIRE WEATHER...
ISSUED AT 232 PM MDT THU MAR 22 2012
RH VALUES WILL APPROACH CRITICAL LEVELS EACH AFTERNOON FROM SATURDAY
THROUGH NEXT WEDNESDAY...PRIMARILY OVER WESTERN PARTS OF OUR
FORECAST AREA. THERE ARE STILL QUESTIONS REGARDING WHETHER WINDS
WILL FALL WITHIN RED FLAG CRITERIA EACH AFTERNOON. THE GUSTIEST
WINDS ARE CURRENTLY EXPECTED SUNDAY AND MONDAY. AT THIS TIME THE
THE BEST CHANCE FOR RED FLAG CRITERIA TO BE MET STILL LOOKS TO BE ON
MONDAY AFTERNOON...WITH WITH WIND GUSTS AROUND 30 MPH AND RH VALUES
IN THE 15-20 PERCENT RANGE. ANOTHER FACTOR TO CONSIDER WILL BE THE
EFFECT OF OUR RECENT RAINFALL ON FUELS. AFTER SEVERAL VERY WARM/DRY
AFTERNOONS FUELS WILL LIKELY BE FAVORABLE...ESPECIALLY BY
SUNDAY/MONDAY AFTERNOONS. IT IS STILL TOO EARLY TO ISSUE A
WATCH/WARNING FOR THESE PERIODS...SO THE SITUATION WILL CONTINUE TO
BE MONITORED.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
KS...NONE.
NE...NONE.
&&
$$
UPDATE...007
SHORT TERM...MENTZER
LONG TERM....DR
AVIATION...007
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
748 PM CDT THU MAR 22 2012
.UPDATE...
ISSUED AT 741 PM CDT THU MAR 22 2012
HAVE PULLED POPS AND WX OUT OF THE GRIDS AS KDDC WSR-88D IS NOT INDICATING
ANY RETURNED POWER AT 0.50 DEG AND HIGHER. CLOUD TOPS PER IR SATELLITE
CHANNEL HAVE BEEN WARMING ACROSS THE CENTRAL AND EASTERN SECTIONS OF
THE CWFA AS WELL. LASTLY, THE 00Z KDDC RAOB SHOWED WARMING AND DRYING
THROUGH THE ATMOSPHERIC COLUMN WITH THE PWAT AT 0.51 INCHES NOW. AM
WATCHING A BAND OF PRECIPITATION ACROSS EASTERN COLORADO ASSOCIATED
WITH THE MAIN UPPER LEVEL LOW FURTHER TO THE SE. THE HRRR HAS PICKED
UP WELL ON THIS FEATURE. HAVE DOUBTS ANY PRECIPITATION WILL REACH THE
GROUND ACROSS FAR WESTERN KANSAS AS THIS MOISTURE LOOKS CONFINED MAINLY
TO THE LOWER TO MID LEVELS AROUND 700 TO 500 HPA.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 343 PM CDT THU MAR 22 2012
MAIN SHORT TERM CHALLENGES TONIGHT WILL BE THE TIMING OF THE END OF
PRECIPITATION. INDICATIONS FROM THE RUC, HRRR, AND NAM12 WOULD SEEM
TO INDICATE THAT THE SHOWER ACTIVITY WILL BE WANING OVER THE NEXT
COUPLE OF HOURS. POPS WILL BE RAPIDLY DECREASING IN THE GRIDS WITH
SLIGHT CHANCE POPS GONE BY 01-02Z OR SO IN THE SOUTHEAST ZONES. THE
FOCUS THEN WILL TURN TO THE FOG DEVELOPMENT. SKIES ARE EXPECTED TO
CLEAR (OR AT LEAST BECOME MOSTLY CLEAR)...ESPECIALLY AFTER 06Z
TONIGHT...AND WITH LIGHT WINDS AT 6 KNOTS OR LESS AND SATURATED
GROUNDS...THE STAGE WILL BE SET FOR FOG FORMATION AS TEMPERATURES
FALL INTO THE MID TO UPPER 30S. WILL BE ADDING AREAS OF FOG TO THE
GRIDS FOR THE 09-14Z TIME FRAME. ON FRIDAY...ONCE THE FOG CLEARS
(IF IT DEVELOPS AS FORECAST) SHORTWAVE RIDGING WILL ADVANCE ON THE
WESTERN PLAINS FROM THE ROCKIES. THE LOW LEVEL RIDGE AXIS WILL
REMAIN OVER WESTERN KANSAS THROUGH THE DAY FRIDAY AND THIS WILL
YIELD LIGHT WINDS ALL DAY AT 6 KNOTS OR LESS. LOW LEVEL THICKNESSES
WILL STILL BE FAIRLY LOW WITH THE UPPER LOW NOT ALL THAT FAR REMOVED
FROM THE PLAINS...SO TEMPERATURES WILL MAX OUT IN THE MID 60S FOR
MOST LOCATIONS...AND LOWER 70S ACROSS FAR SOUTHWEST ZONES WHERE
THICKNESSES WILL BE INCREASING AT A QUICKER RATE WITH THE SHORTWAVE
RIDGE APPROACHING.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 131 PM CDT THU MAR 22 2012
MUCH WARMER AIR WILL RETURN TO WESTERN KANSAS FRIDAY AS THE
UPPER-LEVEL LOW DISCUSSED IN THE SHORT TERM DISCUSSION MOVES INTO
MISSOURI AND SUNSHINE RETURNS. HIGHS SHOULD WARM INTO THE LOWER
TO MID 70S. THE WARM TEMPERATURES WILL PERSIST THROUGH NEXT WEEK
AS UPPER-LEVEL TROUGHING DEVELOPS ACROSS THE WESTERN UNITED
STATES, AND SURFACE LEE TROUGHING DEVELOPS ACROSS THE HIGH PLAINS.
A SHORTWAVE TROUGH WILL PASS ACROSS THE NORTHERN PLAINS BY MONDAY
NIGHT AND TUESDAY. THE GFS/GEM AND ECMWF WERE GENERALLY FOLLOWED
WITH THIS SYSTEM. DESPITE SOME SUBTLE MODEL DIFFERENCES, THE
BOTTOM LINE IS THAT THE UPPER-LEVEL SYSTEM WILL PASS TO OUR NORTH,
WITH LITTLE IN THE WAY OF SYNOPTIC SCALE LIFT OVER WESTERN KANSAS.
TEMPERATURES COULD POSSIBLY REACH INTO THE MID 80S BEHIND THE
DRYLINE IN FAR WESTERN KANSAS MONDAY. RICH LOW-LEVEL MOISTURE
WILL BE DRAWN NORTHWARD ALONG AND EAST OF THE 100TH MERIDIAN IN
ADVANCE OF THE SYSTEM. OFTENTIMES IN MARCH, STRONG FRONTS PUSH THE
LOW-LEVEL MOISTURE DEEP INTO THE TROPICS. BUT SO FAR THIS MARCH WE
HAVE HAD NO PROBLEM GETTING RICH MOISTURE BACK FROM THE GULF IN
THE ABSENCE OF STRONG FRONTAL PASSAGES. A DRYLINE WILL SET UP
ACROSS WESTERN KANSAS MONDAY, WITH AN UNSTABLE AIRMASS DEVELOPING
IMMEDIATELY AHEAD OF IT. HOWEVER, THUNDERSTORMS MAY NOT DEVELOP
SINCE THE ASSOCIATED UPPER-LEVEL JET AND MID-LEVEL COOLING WILL
PASS TO OUR NORTH. BUT AN ISOLATED LATE DAY THUNDERSTORM CANNOT BE
COMPLETELY RULED OUT. AFTER THIS SYSTEM PASSES, THE ASSOCIATED
WEAK COLD FRONT WILL MOVE THROUGH SOUTHWEST KANSAS, KNOCKING
TEMPERATURES DOWN ONLY A FEW DEGREES. IN FACT, TEMPERATURES OUGHT
TO REMAIN ABOVE CLIMATOLOGICAL AVERAGES ALL WEEK AS LEE TROUGHING
QUICKLY REDEVELOPS GIVEN THE FAIRLY ZONAL MID-LEVEL FLOW. A
THUNDERSTORM OR TWO COULD DEVELOP ALONG THE TRAILING COLD FRONT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 600 PM CDT THU MAR 22 2012
VFR CIGS SHOULD PREVAIL TONIGHT AS MOST OF THE SHOWER ACTIVITY WILL
BE OVER BY SUNSET. WINDS WILL BE LIGHT AND VARIABLE OVERNIGHT. LEFT
IFR CIGS FROM FOG DUE TO THE WET GROUND AND CLEARING SKIES. SOME GUIDANCE
IS LESS SUGGESTIVE FOR FOG THAN OTHERS, BUT AT THIS POINT, I DON`T HAVE
ENOUGH CONFIDENCE TO PREFER ONE SOLUTION OVER ANOTHER. WITH THE BENEFICIAL
RAINS LAST NIGHT (WET GROUND) AND THE CLEARING SKIES...DON`T SEE MUCH
OF AN ARGUMENT AGAINST FOG. OTHERWISE, FOG WILL ERODE BY MID MORNING.
WINDS SHOULD BE FAIRLY LIGHT AND WILL EVENTUALLY BE S 5-10 KT BY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 37 67 41 74 / 10 0 0 0
GCK 36 68 40 76 / 0 0 0 0
EHA 36 72 42 77 / 0 0 0 0
LBL 37 71 41 77 / 0 0 0 0
HYS 40 66 41 76 / 10 0 0 0
P28 42 68 43 74 / 20 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SUGDEN
SHORT TERM...UMSCHEID
LONG TERM....FINCH
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1235 PM CDT WED MAR 21 2012
...UPDATED AVIATION SECTION FOR 18Z TAFS...
.UPDATE...
ISSUED AT 1039 AM CDT WED MAR 21 2012
A MID LEVEL DRY HOLE ON THE MESOSCALE WAS EVIDENT ON SATELLITE OVER
FAR NORTHWEST OKLAHOMA...WHICH WAS TAKING ON A RATHER CIRCULAR APPEARANCE
RIGHT AT THE CENTER OF A SMALL SCALE POTENTIAL VORTICITY ANOMALY.
JUST OUTSIDE OF THIS FEATURE ON THE NORTH AND NORTHWEST
SIDE...UPWARD VERTICAL MOTION WAS ENHANCED AND PRECIPITATION WAS
HEAVIEST FROM MEADE COUNTY NORTHEASTWARD INTO NORTHERN CLARK COUNTY
(AS OF 1530 UTC). THE SHORT TERM MODELS...ESPECIALLY THE 3KM
HRRR...BLOSSOM PRECIPITATION ON THE NORTH SIDE OF THIS PV ANOMALY
THROUGH THE DAY WITH HOURLY PRECIPITATION RATES OF 0.10 OF AN INCH
OR GREATER ON THE HRRR EXPANDING OVER MUCH OF SOUTHWEST KANSAS. BY
MID TO LATE AFTERNOON...DIFFERENTIAL HEATING WILL AID IN LOW LEVEL
FRONTOGENETIC CIRCULATION AND AID IN THE LIFT TO ENHANCE
PRECIPITATION ACROSS MUCH OF SOUTHWEST KANSAS. POPS AND QPF GRIDS
HAVE BEEN UPDATED TO REFLECT A BIT HIGHER VALUES GIVEN INCREASED
CONFIDENCE. 0.30 TO 0.50 INCH PRECIPITATION TOTALS ARE IN THE
FORECAST BETWEEN NOW (1530 UTC) AND 0000 UTC THIS EVENING ANYWHERE
FROM THE OKLAHOMA BORDER NORTH TO HIGHWAY 96...AND BETWEEN HIGHWAY
83 AND HIGHWAY 183. DAYTIME TEMPERATURES WERE ALSO LOWERED (NEAR
STEADY IN THE MID TO UPPER 40S) WITH PRECIPITATION AND LOW CLOUDS
EXPECTED ALL DAY.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 256 AM CDT WED MAR 21 2012
LOOKING A THE CURRENT RADAR, LIGHT TO MODERATE SHOWERS ARE OVER
MUCH OF THE CENTRAL PART OF OUR CWA, WITH STRONGER CONVECTION IN
NORTH CENTRAL OKLAHOMA ROTATING NORTHWARD. DECIDED TO CHANGE THE
POPS IN THE COLDWATER AND MEDICINE LODGE TO LIKELY 60 POPS, BASED
MAINLY ON CURRENT RADAR TRENDS. THE SHORT TERM MODELS OF THE HRR,
RUC AND NAM MODELS ALL BRING A BAND OF RAIN FROM 0.20 TO 0.35
INCHES ACROSS OUR NORTHWEST INTO SOUTHWESTERN CWA AFTER 12Z. A
VORTICITY MAX AT 500 AND 700 MB IS FORECAST TO MOVE NORTHWEST AND
INTO OUR WEST BETWEEN 12 AND 18Z, WHERE THERE ALSO APPEARS TO BE A
FRONTOGENESIS ZONE AT THE 700 AND 850 MB LEVELS. MOISTURE IS DEEP
AND IN PLACE AND WILL ONLY GET MORE SATURATED AND DEEPER WITH
TIME. AT 00Z LAST EVENING, NEAR 100 PERCENT RH WAS EVIDENT ON THE
DDC SOUNDING UP TO ABOUT 600MB; FORECAST SOUNDINGS TO 00Z THIS
EVENING SHOWED DEEP MOISTURE TO 450MB. THIS RAISES QUESTION OF HOW
MUCH QPF WE WILL GET. STAYED NEAR THE CURRENT 0.28 TO 0.35 INCH
WEST OF A LACROSSE TO MEADE LINE, AND BASICALLY WHERE 80 TO 90
POPS WILL BE. IN OUR SOUTHEAST, THE PRECIP WILL BE MORE
INTERMITTENT, AND QPF VALUES WILL BE IN THE 0.18 TO 0.21 INCH
RANGE. IS THERE A TORNADO THREAT TODAY? I DON`T THINK IT IS TOO
GREAT, BASED ON LOW LEVEL CAPE VERY LOW AND SHEAR NOT FAVORABLE.
HOWEVER, WITH THAT STATED, THERE WERE REPORTS OF FUNNEL CLOUDS ON
MONDAY, NEAR THE COLD CORE OF THE UPPER LOBE ROTATING THROUGH. THE
COLDEST PART OF THE UPPER LOW WILL BE SOUTH OF OUR CWA DOWN IN
OKLAHOMA. MAY MENTION A SLIGHT CHANCE OF TOR`S IN THE HWO, BUT
DOWN PLAY THE CHANCES. TEMPERATURE TODAY SHOULD BE COLDER THAN
YESTERDAY, WITH MORE PRECIP PLAYING A ROLE, SO LEFT THE GOING
UPPER 40S IN THE WEST AND LOWER TO MID 50S EAST. FURTHERMORE, OUR
WEST WILL BECOME WINDY AS A THE LOW LEVEL GRADIENT TIGHTENS THIS
AFTERNOON, PERHAPS IN THE 20 G 30 MPH RANGE, BUT JUST SHY OF A WIND
ADVISORY.
TONIGHT, THE CENTER OF THE UPPER LOW WILL HAVE MOVED A LITTLE
EASTWARD INTO CENTRAL OKLAHOMA. STRONG ISENTROPIC LIFT WILL STILL
BE OVER MOST OF OUR CWA, THUS LIKELY POPS FOR RAIN AND RAINSHOWERS
WILL BE OVER OUR NORTHWEST HALF PRIOR TO MIDNIGHT, AND THEN LIKELY
POPS SHIFTING SOUTHEAST OF A LINE FROM LARNED TO ASHLAND BY THURSDAY
12Z. AFTER MIDNIGHT, WILL LOWER POPS IN THE NORTHWESTERN 2/3RDS OF
THE CWA TO 30 TO 40 CHANCE POPS, AS MOISTURE WILL MOVE EAST ALONG WITH
THE UPPER AND MID LEVEL LOW PRESSURE SYSTEMS MOVING EAST. EXPECT THE
QPF WILL BE LOWER TONIGHT ALSO, RANGING FROM 0.06 INCH IN THE
SOUTHEAST TO THE 0.15-0.18 INCH RANGE IN THE NORTHWESTERN CWA
BEFORE MIDNIGHT, TO AROUND 0.05-0.08 INCH AFTER MIDNIGHT. MINS WILL
BE TRICKY, AND HIGHLY DEPENDENT OF THE SHIFTING PRECIP, BUT MID
30S IN OUR WEST RANGING TO LOWER 40S IN OUR SOUTHEAST SEEM
APPROPRIATE AND WITHIN ISC TOLERANCES.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 410 AM CDT WED MAR 21 2012
RIGHT NOW IT APPEARS THAT THE 00 UTC GFS AND NAM ARE HANDLING THE
PLACEMENT OF THE UPPER SYSTEM OVER NORTHWEST TEXAS MUCH BETTER THAN
THE 12 UTC RUN OF THE ECMWF. WITH THIS IN MIND WE`LL HEDGE POPS
CLOSER TO THE NAM OR SREF VALUES WHICH FOCUS PRECIPITATION NEAR THE
DEFORMATION AXIS ACROSS THE WESTERN SECTIONS OF THE AREA EARLY
THURSDAY, AND THEN IS MORE FOCUSED IN THE SHARPER ISENTROPIC LIFT
ZONE NEAR THE TRANSIENT 850 LOW OVER CENTRAL KANSAS LATER IN THE
DAY. EVERYTHING ELSE LOOKS IN GOOD SHAPE WIOTH RESPECT TO THIS
SYSTEM INCLUDING THE LOW TO MID 50S TEMPERATURES. ISOLATED
THUNDERSTORMS WILL BE POSSIBLE AND COULD BE EVEN MORE SCATTERED IN
NATURE OVER SOUTH CENTRAL KANSAS THURSDAY AFTERNOON AS THE
INSTABILITY INCREASES DUE TO STEEPENING LAPSE RATES WITH RESPECT TO
THE COLD POOL ALOFT AND WARMING BOUNDARY LAYER TEMEPRATURES.
WE WILL STILL PREFER THE COOLER END OF THE GFS ENSEMBLE OUTPUT FOR
FRIDAY`S MAXIMUM TEMPERATURES SINCE CENTRAL KANSAS WILL STILL BE
UNDER THE INFLUENCE OF A DEEP CYCLONIC NORTHERLY FLOW AND TIGHT
THERMAL PACKING AT THE SURFACE AND ALOFT. LITTLE OVERALL CHANGE WAS
MADE TO THE FORECAST IN THE REST OF THE EXTENDED PERIOD. BOTH THE
ECMWF AND GFS HAVE VERY SIMILAR PATTERNS MOVING INTO THE WEEKEND.
THE UPPER (500 MB LEVEL) LOW PRESSURE CENTER IS LOCATED BY BOTH NEAR
KY/TN BY SUNDAY EVENING, ALLOWING A RIDGE TO BUILD ACROSS THE HIGH
PLAINS REGION. THIS WILL MEAN A PERIOD MARKED BY SOUTHERLY SURFACE
WINDS, AND A WARMING TREND WITH GENERALLY LITTLE CHANCE FOR ANY
THUNDERSTORMS THROUGH THE WEEKEND. THE MODELS DO INDICATE A
RELATIVELY NARROW FETCH OF GULF MOISTURE RETURNING ACROSS WEST TEXAS
EARLY IN THE WEEK, WHICH COULD BRING IN THUNDERSTORM CHANCES BY MID
WEEK. IN FACT, THESE LATEST RUNS OF THE EC AND GFS BOTH SUGGEST THIS
POTENTIAL PERHAPS AS EARLY AS MONDAY AFTERNOON AND EVENING FOR THE
SOUTHERN HIGH PLAINS. A SOUTHERN STREAM SUBTROPICAL JET WILL PLAY A
ROLE AS WELL AS A VIGOROUS SHORTWAVE ROTATING THROUGH THE WESTERN
STATES TOWARD THE NORTHERN HIGH PLAINS ON TUESDAY. ANY ONE OF THESE
DAYS COULD BRING DRYLINE THUNDERSTORM DEVELOPMENT. THE CURRENT
ALLBLEND IS NOT YET FAVORABLE FOR DEVELOPING SIGNIFICANT POPS FOR
SUCH AND OCCURRENCE. THE ATMOSPHERE WILL BE RECOVERING FROM A
RELATIVELY COOL PERIOD WITH TEMPERATURES NEAR NORMAL AND THE AIRMASS
BEHIND THIS WILL NOT BE ANOMALOUSLY WARM. TEMPERATURES WILL BE
WARMER THAN NORMAL BY ABOUT 10 TO 15 DEGREES HEADING INTO THE
WEEKEND AND PERHAPS HITTING 80 DEGREES OR MORE BY EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1228 PM CDT WED MAR 21 2012
RAIN SHOWERS AND LOW CEILINGS WILL CONTINUE TO PLAGUE THE DDC,
GCK, AND HYS TERMINALS THROUGH THE REMAINDER OF THE DAY AND INTO
TONIGHT. PREVAILING CEILING THROUGH THIS AFTERNOON AT DDC AND GCK
WILL BE RIGHT AT OR JUST ABOVE IFR THRESHOLD AT 1000 TO 1500 FEET
OUTSIDE OF SHOWERS...BUT IN SHOWERS THE VISIBILITY WILL FALL TO 2
MILES OR BELOW AT TIMES WITH CEILING A FEW HUNDRED FEET. DURING
THE NIGHT TONIGHT...PREVAILING FLIGHT CATEGORY IS EXPECTED TO BE
WELL INTO THE IFR RANGE AND PERHAPS LIFR AT TIMES..ESPECIALLY
09-13Z THURSDAY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 49 41 53 36 / 100 100 70 0
GCK 47 39 55 34 / 100 100 50 0
EHA 44 39 54 37 / 80 80 60 0
LBL 48 39 55 37 / 100 90 70 0
HYS 53 41 53 35 / 90 100 50 0
P28 59 43 56 38 / 90 90 80 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...UMSCHEID
SHORT TERM...BURKE
LONG TERM....RUSSELL
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1041 AM CDT WED MAR 21 2012
.UPDATE...
ISSUED AT 1039 AM CDT WED MAR 21 2012
A MID LEVEL DRY HOLE ON THE MESOSCALE WAS EVIDENT ON SATELLITE OVER
FAR NORTHWEST OKLAHOMA...WHICH WAS TAKING ON A RATHER CIRCULAR APPEARANCE
RIGHT AT THE CENTER OF A SMALL SCALE POTENTIAL VORTICITY ANOMALY.
JUST OUTSIDE OF THIS FEATURE ON THE NORTH AND NORTHWEST
SIDE...UPWARD VERTICAL MOTION WAS ENHANCED AND PRECIPITATION WAS
HEAVIEST FROM MEADE COUNTY NORTHEASTWARD INTO NORTHERN CLARK COUNTY
(AS OF 1530 UTC). THE SHORT TERM MODELS...ESPECIALLY THE 3KM
HRRR...BLOSSOM PRECIPITATION ON THE NORTH SIDE OF THIS PV ANOMALY
THROUGH THE DAY WITH HOURLY PRECIPITATION RATES OF 0.10 OF AN INCH
OR GREATER ON THE HRRR EXPANDING OVER MUCH OF SOUTHWEST KANSAS. BY
MID TO LATE AFTERNOON...DIFFERENTIAL HEATING WILL AID IN LOW LEVEL
FRONTOGENETIC CIRCULATION AND AID IN THE LIFT TO ENHANCE
PRECIPITATION ACROSS MUCH OF SOUTHWEST KANSAS. POPS AND QPF GRIDS
HAVE BEEN UPDATED TO REFLECT A BIT HIGHER VALUES GIVEN INCREASED
CONFIDENCE. 0.30 TO 0.50 INCH PRECIPITATION TOTALS ARE IN THE
FORECAST BETWEEN NOW (1530 UTC) AND 0000 UTC THIS EVENING ANYWHERE
FROM THE OKLAHOMA BORDER NORTH TO HIGHWAY 96...AND BETWEEN HIGHWAY
83 AND HIGHWAY 183. DAYTIME TEMPERATURES WERE ALSO LOWERED (NEAR
STEADY IN THE MID TO UPPER 40S) WITH PRECIPITATION AND LOW CLOUDS
EXPECTED ALL DAY.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 256 AM CDT WED MAR 21 2012
LOOKING A THE CURRENT RADAR, LIGHT TO MODERATE SHOWERS ARE OVER
MUCH OF THE CENTRAL PART OF OUR CWA, WITH STRONGER CONVECTION IN
NORTH CENTRAL OKLAHOMA ROTATING NORTHWARD. DECIDED TO CHANGE THE
POPS IN THE COLDWATER AND MEDICINE LODGE TO LIKELY 60 POPS, BASED
MAINLY ON CURRENT RADAR TRENDS. THE SHORT TERM MODELS OF THE HRR,
RUC AND NAM MODELS ALL BRING A BAND OF RAIN FROM 0.20 TO 0.35
INCHES ACROSS OUR NORTHWEST INTO SOUTHWESTERN CWA AFTER 12Z. A
VORTICITY MAX AT 500 AND 700 MB IS FORECAST TO MOVE NORTHWEST AND
INTO OUR WEST BETWEEN 12 AND 18Z, WHERE THERE ALSO APPEARS TO BE A
FRONTOGENESIS ZONE AT THE 700 AND 850 MB LEVELS. MOISTURE IS DEEP
AND IN PLACE AND WILL ONLY GET MORE SATURATED AND DEEPER WITH
TIME. AT 00Z LAST EVENING, NEAR 100 PERCENT RH WAS EVIDENT ON THE
DDC SOUNDING UP TO ABOUT 600MB; FORECAST SOUNDINGS TO 00Z THIS
EVENING SHOWED DEEP MOISTURE TO 450MB. THIS RAISES QUESTION OF HOW
MUCH QPF WE WILL GET. STAYED NEAR THE CURRENT 0.28 TO 0.35 INCH
WEST OF A LACROSSE TO MEADE LINE, AND BASICALLY WHERE 80 TO 90
POPS WILL BE. IN OUR SOUTHEAST, THE PRECIP WILL BE MORE
INTERMITTENT, AND QPF VALUES WILL BE IN THE 0.18 TO 0.21 INCH
RANGE. IS THERE A TORNADO THREAT TODAY? I DON`T THINK IT IS TOO
GREAT, BASED ON LOW LEVEL CAPE VERY LOW AND SHEAR NOT FAVORABLE.
HOWEVER, WITH THAT STATED, THERE WERE REPORTS OF FUNNEL CLOUDS ON
MONDAY, NEAR THE COLD CORE OF THE UPPER LOBE ROTATING THROUGH. THE
COLDEST PART OF THE UPPER LOW WILL BE SOUTH OF OUR CWA DOWN IN
OKLAHOMA. MAY MENTION A SLIGHT CHANCE OF TOR`S IN THE HWO, BUT
DOWN PLAY THE CHANCES. TEMPERATURE TODAY SHOULD BE COLDER THAN
YESTERDAY, WITH MORE PRECIP PLAYING A ROLE, SO LEFT THE GOING
UPPER 40S IN THE WEST AND LOWER TO MID 50S EAST. FURTHERMORE, OUR
WEST WILL BECOME WINDY AS A THE LOW LEVEL GRADIENT TIGHTENS THIS
AFTERNOON, PERHAPS IN THE 20 G 30 MPH RANGE, BUT JUST SHY OF A WIND
ADVISORY.
TONIGHT, THE CENTER OF THE UPPER LOW WILL HAVE MOVED A LITTLE
EASTWARD INTO CENTRAL OKLAHOMA. STRONG ISENTROPIC LIFT WILL STILL
BE OVER MOST OF OUR CWA, THUS LIKELY POPS FOR RAIN AND RAINSHOWERS
WILL BE OVER OUR NORTHWEST HALF PRIOR TO MIDNIGHT, AND THEN LIKELY
POPS SHIFTING SOUTHEAST OF A LINE FROM LARNED TO ASHLAND BY THURSDAY
12Z. AFTER MIDNIGHT, WILL LOWER POPS IN THE NORTHWESTERN 2/3RDS OF
THE CWA TO 30 TO 40 CHANCE POPS, AS MOISTURE WILL MOVE EAST ALONG WITH
THE UPPER AND MID LEVEL LOW PRESSURE SYSTEMS MOVING EAST. EXPECT THE
QPF WILL BE LOWER TONIGHT ALSO, RANGING FROM 0.06 INCH IN THE
SOUTHEAST TO THE 0.15-0.18 INCH RANGE IN THE NORTHWESTERN CWA
BEFORE MIDNIGHT, TO AROUND 0.05-0.08 INCH AFTER MIDNIGHT. MINS WILL
BE TRICKY, AND HIGHLY DEPENDENT OF THE SHIFTING PRECIP, BUT MID
30S IN OUR WEST RANGING TO LOWER 40S IN OUR SOUTHEAST SEEM
APPROPRIATE AND WITHIN ISC TOLERANCES.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 410 AM CDT WED MAR 21 2012
RIGHT NOW IT APPEARS THAT THE 00 UTC GFS AND NAM ARE HANDLING THE
PLACEMENT OF THE UPPER SYSTEM OVER NORTHWEST TEXAS MUCH BETTER THAN
THE 12 UTC RUN OF THE ECMWF. WITH THIS IN MIND WE`LL HEDGE POPS
CLOSER TO THE NAM OR SREF VALUES WHICH FOCUS PRECIPITATION NEAR THE
DEFORMATION AXIS ACROSS THE WESTERN SECTIONS OF THE AREA EARLY
THURSDAY, AND THEN IS MORE FOCUSED IN THE SHARPER ISENTROPIC LIFT
ZONE NEAR THE TRANSIENT 850 LOW OVER CENTRAL KANSAS LATER IN THE
DAY. EVERYTHING ELSE LOOKS IN GOOD SHAPE WIOTH RESPECT TO THIS
SYSTEM INCLUDING THE LOW TO MID 50S TEMPERATURES. ISOLATED
THUNDERSTORMS WILL BE POSSIBLE AND COULD BE EVEN MORE SCATTERED IN
NATURE OVER SOUTH CENTRAL KANSAS THURSDAY AFTERNOON AS THE
INSTABILITY INCREASES DUE TO STEEPENING LAPSE RATES WITH RESPECT TO
THE COLD POOL ALOFT AND WARMING BOUNDARY LAYER TEMEPRATURES.
WE WILL STILL PREFER THE COOLER END OF THE GFS ENSEMBLE OUTPUT FOR
FRIDAY`S MAXIMUM TEMPERATURES SINCE CENTRAL KANSAS WILL STILL BE
UNDER THE INFLUENCE OF A DEEP CYCLONIC NORTHERLY FLOW AND TIGHT
THERMAL PACKING AT THE SURFACE AND ALOFT. LITTLE OVERALL CHANGE WAS
MADE TO THE FORECAST IN THE REST OF THE EXTENDED PERIOD. BOTH THE
ECMWF AND GFS HAVE VERY SIMILAR PATTERNS MOVING INTO THE WEEKEND.
THE UPPER (500 MB LEVEL) LOW PRESSURE CENTER IS LOCATED BY BOTH NEAR
KY/TN BY SUNDAY EVENING, ALLOWING A RIDGE TO BUILD ACROSS THE HIGH
PLAINS REGION. THIS WILL MEAN A PERIOD MARKED BY SOUTHERLY SURFACE
WINDS, AND A WARMING TREND WITH GENERALLY LITTLE CHANCE FOR ANY
THUNDERSTORMS THROUGH THE WEEKEND. THE MODELS DO INDICATE A
RELATIVELY NARROW FETCH OF GULF MOISTURE RETURNING ACROSS WEST TEXAS
EARLY IN THE WEEK, WHICH COULD BRING IN THUNDERSTORM CHANCES BY MID
WEEK. IN FACT, THESE LATEST RUNS OF THE EC AND GFS BOTH SUGGEST THIS
POTENTIAL PERHAPS AS EARLY AS MONDAY AFTERNOON AND EVENING FOR THE
SOUTHERN HIGH PLAINS. A SOUTHERN STREAM SUBTROPICAL JET WILL PLAY A
ROLE AS WELL AS A VIGOROUS SHORTWAVE ROTATING THROUGH THE WESTERN
STATES TOWARD THE NORTHERN HIGH PLAINS ON TUESDAY. ANY ONE OF THESE
DAYS COULD BRING DRYLINE THUNDERSTORM DEVELOPMENT. THE CURRENT
ALLBLEND IS NOT YET FAVORABLE FOR DEVELOPING SIGNIFICANT POPS FOR
SUCH AND OCCURRENCE. THE ATMOSPHERE WILL BE RECOVERING FROM A
RELATIVELY COOL PERIOD WITH TEMPERATURES NEAR NORMAL AND THE AIRMASS
BEHIND THIS WILL NOT BE ANOMALOUSLY WARM. TEMPERATURES WILL BE
WARMER THAN NORMAL BY ABOUT 10 TO 15 DEGREES HEADING INTO THE
WEEKEND AND PERHAPS HITTING 80 DEGREES OR MORE BY EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 758 AM CDT WED MAR 21 2012
AN UPPER LOW OVER THE RED RIVER VALLEY WILL LIFT INTO CENTRAL KANSAS
OVER THE NEXT 24 HOURS. WIDESPREAD LIFR CEILINGS ARE LIFTING
NORTHWARD JUST AHEAD OF THIS LOW AND WILL CONTINUE TO AFFECT THE HYS
AND DDC TERMINALS THOUGH MUCH OF TODAY. A PERIOD OF DEFORMATION
PRECIPITATION WILL OCCUR AGAIN LATER THIS EVENING THAT WILL LIKELY
AFFECT THE KGCK TERMINAL. ISOLATED TSRA CANNOT BE RULED OUT IN THE
VICINITY OF ANY OF THE TERMINALS. BEST CHANCES FOR TSRA WILL BE
NEAR KDDC AND KHYS OVERNIGHT AND DURING THE DAY THURSDAY AS THE
LOW MOVES THROUGH CENTRAL KANSAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 49 39 55 37 / 90 80 70 30
GCK 47 37 55 35 / 90 80 50 20
EHA 44 37 55 38 / 90 80 80 20
LBL 48 37 55 38 / 90 80 60 20
HYS 53 39 56 36 / 70 80 40 30
P28 59 41 55 39 / 90 80 90 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...UMSCHEID
SHORT TERM...BURKE
LONG TERM....RUSSELL
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS TOPEKA KS
317 AM CDT WED MAR 21 2012
.DISCUSSION...
THE CLOSED UPPER LOW WAS LOCATED ACROSS THE SOUTHEAST TX PNHDL EARLY
THIS MORNING. THE UPPER LOW WILL DRIFT NORTHEAST ACROSS WESTERN OK
TODAY...THEN CONTINUE TO DRIFT SLOWLY NORTHEASTWARD ACROSS SOUTHEAST
KS INTO WESTERN MO ON FRIDAY.
TODAY...SHORTER WAVE LENGTH H5 TROUGHS WILL ROTATE AROUND THE CLOSED
UPPER LOW AND WILL PROVIDE ASCENT FOR PERIODS OF SHOWERS THROUGH THE
DAY. THE RAIN MAY BE MORE WIDESPREAD LATE THIS MORNING THROUGH THE
AFTERNOON AS SLIGHTLY DEEPER MOISTURE AT 850MB IS ADVECTED NORTHWEST
ACROSS THE CWA. I DO NOT SEE MUCH IN THE WAY OF INSTABILITY FOR
THUNDERSTORMS...SO I WILL NOT INCLUDE THEM IN THE FORECAST FOR
TODAY. QPF WILL RANGE FROM 0.10 INCH ACROSS THE SOUTHWEST CWA UP TO
0.25 INCH ACROSS THE NORTHEAST COUNTIES.
TONIGHT...THE 700MB DRY SLOT WILL ROTATE NORTHWEST ACROSS THE UPPER
LOW. WE MAY SEE A DECREASE IN THE SHOWERS ACROSS THE CWA...THOUGH
LOW-LEVEL ISENTROPIC LIFT WILL CAUSE PERIODS OF DRIZZLE AND THIS MAY
ACCUMULATE A COUPLE HUNDREDTHS OF AN INCH OF LIQUID PRECIP. LOWS
WILL ONLY DROP OFF INTO THE MID TO UPPER 40S.
THURSDAY AND FRIDAY...AS THE COLD CORE UPPER LOW MOVES ACROSS
EASTERN KS WE WILL HAVE A CHANCE FOR SHOWERS AND PERHAPS SOME
THUNDERSTORMS. SKIES CLEAR A BIT DURING THE AFTERNOON AND WE RECEIVE
SOME SURFACE HEATING...THEN LAPSE RATES SHOULD BE SUFFICIENT UNDER
THE COLD CORE LOW TO PRODUCE ENOUGH INSTABILITY FOR ISOLATED TO
SCATTERED THUNDERSTORMS THURSDAY AFTERNOON...AND PERHAPS AGAIN
FRIDAY AFTERNOON FOR THE EASTERN HALF OF THE CWA. THE THUNDERSTORMS
SHOULD NOT BE SEVERE DUE TO THE LACK OF DEEPER GULF MOISTURE. HIGHS
WILL WARM INTO THE LOWER 60S ON THURSDAY WITH MID 60S ON FRIDAY.
FRIDAY NIGHT THROUGH MONDAY...THE UPPER LOW WILL MOVE EAST TOWARD
THE MID ATLANTIC STATES. A H5 TROUGH WILL MOVE ONSHORE ACROSS THE
WESTERN CONUS SUNDAY INTO MONDAY. A DOWNSTREAM H5 RIDGE WILL AMPLIFY
ACROSS THE PLAINS THIS WEEKEND THEN TRANSLATE EASTWARD ACROSS THE
EAST CENTRAL CONUS EARLY NEXT WEEK. EXPECT DRY CONDITIONS WITH A
WARMING TREND. HIGHS WILL BE IN THE LOWER 70S ON SATURDAY...MID 70S
ON SUNDAY AND UPPER 70S AND LOWER 80S BY MONDAY.
MONDAY NIGHT AND TUESDAY...THE H5 TROUGH ACROSS THE WESTERN CONUS
WILL LIFT NORTHEAST INTO THE NORTHERN PLAINS BY LATE TUESDAY. DEEPER
MOISTURE WILL RETURN AHEAD OF A DEEPENING LEE TROUGH MONDAY NIGHT...
AND THE RESULTING ISENTROPIC LIFT AHEAD OF THE DEEPER MOISTURE
RETURN MAY BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE
CWA LATE MONDAY NIGHT INTO TUESDAY MORNING. A PACIFIC COLD FRONT
WILL MOVE EAST ACROSS THE STATE ON TUESDAY AS THE H5 TROUGH LIFTS
NORTHEAST ACROSS THE NORTHERN AND CENTRAL PLAINS. SFC CONVERGENCE
AHEAD OF THE FRONT WILL CAUSE SHOWERS AND THUNDERSTORMS TO DEVELOP
ACROSS THE CWA TUESDAY AFTERNOON. THE SOUTHWESTERLY UPPER FLOW LOOKS
WEAK...SO THE THUNDERSTORMS TUESDAY AFTERNOON MAY NOT BE SEVERE.
GARGAN
&&
.AVIATION...
THERE REMAINS A GREAT DEAL OF UNCERTAINTY IN THE HEIGHTS OF THE
CIGS...WITH OBS JUMPING ALL AROUND. LATEST GUIDANCE FROM THE NAM
AND RUC SUGGESTS THAT CIGS SHOULD BE BETWEEN 2 AND 3 KFT AT BEST.
THIS SEEMS TO MAKE SINCE WITH AN EASTERLY LOW LEVEL WIND ADVECTING
HIGHER MOISTURE INTO CENTRAL KS. THEREFORE BEST GUESS IS FOR COGS
TO REMAIN AROUND 2 KFT THROUGH THE NIGHT. THERE MAY ALSO BE SOME
LIGHT DZ OR RA...HOWEVER MODELS SHOW THE BEST ISENTROPIC LIFT
DEVELOPING TOWARDS LATE MORNING. MODELS ALSO HAVE THE BETTER
VERTICAL MOTION DURING THE AFTERNOON. THEREFORE WILL FOCUS
PERSISTENT RAIN DURING THIS PERIOD. THINK THERE SHOULD BE A BREAK
IN PRECIP CHANCES WEDNESDAY EVENING AS ISENTROPIC LIFT BECOMES LESS
ORGANIZED. OVERALL THIS FORECAST IS LOW CONFIDENCE WITH RESPECT TO
THE CIGS HEIGHTS AND TIMING OF PRECIP.
WOLTERS
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
105 AM MDT WED MAR 21 2012
.UPDATE...
ISSUED AT 846 PM MDT TUE MAR 20 2012
TONIGHT-WEDNESDAY...UPDATED TO LOWER POPS TONIGHT AND SLOW THE
INCREASE IN POPS WEDNESDAY. KGLD RADAR SHOWING NO PRECIPITATION
ACROSS THE AREA. 00Z NAM/RUC AND LATEST HRRR AND EVEN THE 18Z GFS
SHOW THAT ALTHOUGH PLENTIFUL MOISTURE IS AVAILABLE FOR
PRECIPITATION MOST OF IT WILL BE ACROSS THE FAR EAST AND SOUTHEAST
PARTS OF THE AREA FOR MUCH OF THE REMAINDER OF THE NIGHT. WASNT AS
CONFIDENT IN CONFINING POPS TOMORROW MORNING TO THE SAME AREAS AS
00Z GFS HASNT COME IN YET. BASED ON THE NAM/ECMWF AND SREF BULK OF
PRECIP WILL BE ACROSS THE EASTERN 1/3 OF THE AREA. WILL CONTINUE
TO MONITOR FOR POSSIBLE FURTHER ADJUSTMENTS.
OTHER ADJUSTMENTS WERE MADE TO ALL REMAINING WX PARAMETERS THROUGH
THE REST OF THE NIGHT INTO WEDNESDAY MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 230 PM MDT TUE MAR 20 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW LONGWAVE TROUGH
DRAPED ACROSS THE INTER-MOUNTAIN WEST WITH A CLOSED CIRCULATION
CENTERED OVER WESTERN TEXAS/EASTERN NEW MEXICO. THIS CLOSED LOW
WILL BE THE BIG WEATHER MAKER FOR OUR AREA THE NEXT SEVERAL
DAYS.
FORECAST CONTINUES TO BE ON TRACK WITH SCATTERED RAIN SHOWERS OVER
CENTRAL KS ALREADY MOVING TOWARDS CWA. THIS SHOWER ACTIVITY WILL
SPREAD INTO THE CWA FROM THE E/SE AND INCREASE IN COVERAGE THROUGH
THE NIGHTTIME PERIOD. MODEL SOUNDING ANALYSIS WOULD SUPPORT MAINLY
RAIN FOR THE EVENT. THERE IS THE POTENTIAL FOR A RAIN/SNOW CHANGE
OVER BASED ON FAVORABLE WBZ HEIGHTS ACROSS THE WESTERN HALF OF THE
CWA IN THE 09-12Z TIME-FRAME TONIGHT. AS THE UPPER LOW SLOWLY
SHIFTS NORTH...MOISTURE AND LIFT WILL CONTINUE TO ROTATE INTO THE
CWA WEDNESDAY AND WEDNESDAY NIGHT...WITH PERIODS OF RAIN SHOWERS
EXPECTED ACROSS THE CWA. I LEFT ISO THUNDERSTORM MENTION WED
AFTERNOON/EARLY EVENING WHERE ECMWF/GFS STILL SHOWS WEAK ELEVATED
INSTABILITY. OVERALL IT LOOKS LIKE WE COULD SEE DECENT RAINFALL
OUT OF THIS WITH 0.50-1.00" OF RAIN POSSIBLE FOR THE EVENT.
AS THE UPPER LOW SHIFTS NORTH THURSDAY A DRY SLOT WILL WORK ITS
WAY W/NW INTO OUR CWA. GUIDANCE IS IN PRETTY GOOD AGREEMENT ON A
BAND OF PRECIP LINGERING OVER THE WESTERN CWA THROUGH THURSDAY
NIGHT...WITH DECREASING COVERAGE IN THE EAST. IN THE EXTREME SE
PART OF THE CWA CLOSER TO THE UPPER LOW CENTER THERE COULD STILL
BE ADDITIONAL SHOWER RE-DEVELOPMENT THURSDAY AFTERNOON WITH THE
COLD POOL ALOFT...SO I ONLY TRENDED POPS DOWN FROM PREVIOUS
FORECAST THURSDAY AND THURSDAY NIGHT OVER EASTERN LOCATIONS.
LOW TEMPS TONIGHT AND WEDNESDAY NIGHT WILL BE HELD UP BY WIND AND
CLOUD COVER...SO VALUES SHOULD REMAIN IN MID 30S TO NEAR 40 FOR
MOST OF THE AREA. HIGH TEMPS WEDNESDAY AND THURSDAY WILL ALSO BE
AFFECTED BY PRECIP/CLOUDS....WITH THE COOLEST DAY ON WEDNESDAY
WITH TEMPS STRUGGLING TO WARM ABOVE THE UPPER 40S OVER THE
SOUTHERN HALF OF THE CWA. TEMPS ON THURSDAY WILL MODERATE SOME
WITH VALUES GENERALLY IN THE MID-UPPER 50S FOR MOST OF THE AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 100 AM MDT WED MAR 21 2012
UPPER LOW WILL BE MOVING AWAY FROM THE AREA ON THURSDAY NIGHT WITH
THREAT OF SHOWERS ENDING. UPPER RIDGE WILL BUILD IN ITS WAKE AND
DOMINATE THE LONG TERM PERIOD...RESULTING IN WARM AND DRY
CONDITIONS. NEXT SHORTWAVE TROUGH WILL MOVE ACROSS THE CENTRAL
AND NORTHERN ROCKIES ON MONDAY AND TUESDAY OF NEXT WEEK...A TRACK
WHICH SUGGESTS THE CENTRAL HIGH PLAINS WILL BE DRY SLOTTED.
HOWEVER...ASSOCIATED SURFACE COLD FRONT WILL KNOCK TEMPERATURES
DOWN 10 DEGREES OR SO THE LAST COUPLE OF DAYS OF THIS PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1039 PM MDT TUE MAR 20 2012
STARTING TO SEE AN INCREASE IN SPOTTY RADAR ECHOES JUST EAST OF
KHLC WITH ACTIVITY MOVING WEST. STILL THINKING IS THAT BOTH KGLD
AND KMCK TERMINALS WILL BE DRY THROUGH AT LEAST 14Z WITH A SLOW
INCREASE IN RAIN/SHOWER POTENTIAL AFTERWARD WITH THE BEST CHANCE
AFTER 17Z AT KMCK AND 00Z-03Z AT KGLD. CIGS WILL REMAIN VFR
THROUGH 00Z OR SO BEFORE FALLING INTO THE MVFR RANGE AND POSSIBLY
IFR RANGE (CLOSER TO 06Z). NORTH TO NORTHEAST WINDS GUSTING AROUND
30 KTS EXPECTED AROUND 15Z-17Z AND CONTINUING THROUGH 00Z BEFORE
SUBSIDING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
KS...NONE.
NE...NONE.
&&
$$
UPDATE...007
SHORT TERM...DR
LONG TERM....024
AVIATION...007
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1049 PM MDT TUE MAR 20 2012
.UPDATE...
ISSUED AT 846 PM MDT TUE MAR 20 2012
TONIGHT-WEDNESDAY...UPDATED TO LOWER POPS TONIGHT AND SLOW THE
INCREASE IN POPS WEDNESDAY. KGLD RADAR SHOWING NO PRECIPITATION
ACROSS THE AREA. 00Z NAM/RUC AND LATEST HRRR AND EVEN THE 18Z GFS
SHOW THAT ALTHOUGH PLENTIFUL MOISTURE IS AVAILABLE FOR
PRECIPITATION MOST OF IT WILL BE ACROSS THE FAR EAST AND SOUTHEAST
PARTS OF THE AREA FOR MUCH OF THE REMAINDER OF THE NIGHT. WASNT AS
CONFIDENT IN CONFINING POPS TOMORROW MORNING TO THE SAME AREAS AS
00Z GFS HASNT COME IN YET. BASED ON THE NAM/ECMWF AND SREF BULK OF
PRECIP WILL BE ACROSS THE EASTERN 1/3 OF THE AREA. WILL CONTINUE
TO MONITOR FOR POSSIBLE FURTHER ADJUSTMENTS.
OTHER ADJUSTMENTS WERE MADE TO ALL REMAINING WX PARAMETERS THROUGH
THE REST OF THE NIGHT INTO WEDNESDAY MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 230 PM MDT TUE MAR 20 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW LONGWAVE TROUGH
DRAPED ACROSS THE INTER-MOUNTAIN WEST WITH A CLOSED CIRCULATION
CENTERED OVER WESTERN TEXAS/EASTERN NEW MEXICO. THIS CLOSED LOW
WILL BE THE BIG WEATHER MAKER FOR OUR AREA THE NEXT SEVERAL
DAYS.
FORECAST CONTINUES TO BE ON TRACK WITH SCATTERED RAIN SHOWERS OVER
CENTRAL KS ALREADY MOVING TOWARDS CWA. THIS SHOWER ACTIVITY WILL
SPREAD INTO THE CWA FROM THE E/SE AND INCREASE IN COVERAGE THROUGH
THE NIGHTTIME PERIOD. MODEL SOUNDING ANALYSIS WOULD SUPPORT MAINLY
RAIN FOR THE EVENT. THERE IS THE POTENTIAL FOR A RAIN/SNOW CHANGE
OVER BASED ON FAVORABLE WBZ HEIGHTS ACROSS THE WESTERN HALF OF THE
CWA IN THE 09-12Z TIME-FRAME TONIGHT. AS THE UPPER LOW SLOWLY
SHIFTS NORTH...MOISTURE AND LIFT WILL CONTINUE TO ROTATE INTO THE
CWA WEDNESDAY AND WEDNESDAY NIGHT...WITH PERIODS OF RAIN SHOWERS
EXPECTED ACROSS THE CWA. I LEFT ISO THUNDERSTORM MENTION WED
AFTERNOON/EARLY EVENING WHERE ECMWF/GFS STILL SHOWS WEAK ELEVATED
INSTABILITY. OVERALL IT LOOKS LIKE WE COULD SEE DECENT RAINFALL
OUT OF THIS WITH 0.50-1.00" OF RAIN POSSIBLE FOR THE EVENT.
AS THE UPPER LOW SHIFTS NORTH THURSDAY A DRY SLOT WILL WORK ITS
WAY W/NW INTO OUR CWA. GUIDANCE IS IN PRETTY GOOD AGREEMENT ON A
BAND OF PRECIP LINGERING OVER THE WESTERN CWA THROUGH THURSDAY
NIGHT...WITH DECREASING COVERAGE IN THE EAST. IN THE EXTREME SE
PART OF THE CWA CLOSER TO THE UPPER LOW CENTER THERE COULD STILL
BE ADDITIONAL SHOWER RE-DEVELOPMENT THURSDAY AFTERNOON WITH THE
COLD POOL ALOFT...SO I ONLY TRENDED POPS DOWN FROM PREVIOUS
FORECAST THURSDAY AND THURSDAY NIGHT OVER EASTERN LOCATIONS.
LOW TEMPS TONIGHT AND WEDNESDAY NIGHT WILL BE HELD UP BY WIND AND
CLOUD COVER...SO VALUES SHOULD REMAIN IN MID 30S TO NEAR 40 FOR
MOST OF THE AREA. HIGH TEMPS WEDNESDAY AND THURSDAY WILL ALSO BE
AFFECTED BY PRECIP/CLOUDS....WITH THE COOLEST DAY ON WEDNESDAY
WITH TEMPS STRUGGLING TO WARM ABOVE THE UPPER 40S OVER THE
SOUTHERN HALF OF THE CWA. TEMPS ON THURSDAY WILL MODERATE SOME
WITH VALUES GENERALLY IN THE MID-UPPER 50S FOR MOST OF THE AREA.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 230 PM MDT TUE MAR 20 2012
A RETURN TO DRY CONDITIONS AND VERY WARM TEMPERATURES ARE EXPECTED
AS A STRONG RIDGE DEVELOPS ACROSS THE CENTRAL US. WHILE THE ENTIRE
EXTENDED PERIOD LOOKS TO BE ABOVE NORMAL...HIGH TEMPS SATURDAY
THROUGH MONDAY COULD APPROACH RECORD LEVELS SIMILAR TO WHAT WE SAW
DURING OUR WARM-UP LAST WEEK. HIGH TEMPS GENERALLY IN THE UPPER
70S ARE EXPECTED ON SATURDAY...AND WITH VALUES IN THE LOW 80S OVER
A LARGE PART OF THE AREA POSSIBLE SUNDAY AND MONDAY. A SHORTWAVE
TROUGH WILL BEGIN TO SHIFT EAST TOWARDS THE NORTHERN PLAINS MONDAY
NIGHT/TUESDAY AS THE H5 RIDGE BEGINS TO BREAK DOW. A COLD FRONT
WILL DROP SOUTH ACROSS THE CWA BY TUESDAY. THE MAIN EFFECT WILL BE
TO BRING COOLER TEMPERATURES TO THE REGION WITH VALUES IN THE LOW-
UPPER 60S FOR MUCH OF THE CWA. THERE IS SOME INDICATION OF
THUNDERSTORM DEVELOPMENT MONDAY AFTERNOON WITH A DRY LINE LINGERING
OVER THE CWA AND INSTABILITY BUILDING INTO WESTERN AND CENTRAL
KANSAS. A STRONG CAP AND VERY DRY AIR MASS IN PLACE WILL LIMIT
CONVECTIVE POTENTIAL...SO I LEFT MENTION OUT OF THE FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1039 PM MDT TUE MAR 20 2012
STARTING TO SEE AN INCREASE IN SPOTTY RADAR ECHOES JUST EAST OF
KHLC WITH ACTIVITY MOVING WEST. STILL THINKING IS THAT BOTH KGLD
AND KMCK TERMINALS WILL BE DRY THROUGH AT LEAST 14Z WITH A SLOW
INCREASE IN RAIN/SHOWER POTENTIAL AFTERWARD WITH THE BEST CHANCE
AFTER 17Z AT KMCK AND 00Z-03Z AT KGLD. CIGS WILL REMAIN VFR
THROUGH 00Z OR SO BEFORE FALLING INTO THE MVFR RANGE AND POSSIBLY
IFR RANGE (CLOSER TO 06Z). NORTH TO NORTHEAST WINDS GUSTING AROUND
30 KTS EXPECTED AROUND 15Z-17Z AND CONTINUING THROUGH 00Z BEFORE
SUBSIDING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
KS...NONE.
NE...NONE.
&&
$$
UPDATE...007
SHORT TERM...DR
LONG TERM....DR
AVIATION...007
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1125 PM CDT TUE MAR 20 2012
...AVIATION UPDATE...
.DISCUSSION...
SEE PREV DISCUSSION.
&&
.AVIATION...
THERE REMAINS A GREAT DEAL OF UNCERTAINTY IN THE HEIGHTS OF THE
CIGS...WITH OBS JUMPING ALL AROUND. LATEST GUIDANCE FROM THE NAM
AND RUC SUGGESTS THAT CIGS SHOULD BE BETWEEN 2 AND 3 KFT AT BEST.
THIS SEEMS TO MAKE SINCE WITH AN EASTERLY LOW LEVEL WIND ADVECTING
HIGHER MOISTURE INTO CENTRAL KS. THEREFORE BEST GUESS IS FOR COGS
TO REMAIN AROUND 2 KFT THROUGH THE NIGHT. THERE MAY ALSO BE SOME
LIGHT DZ OR RA...HOWEVER MODELS SHOW THE BEST ISENTROPIC LIFT
DEVELOPING TOWARDS LATE MORNING. MODELS ALSO HAVE THE BETTER
VERTICAL MOTION DURING THE AFTERNOON. THEREFORE WILL FOCUS
PERSISTENT RAIN DURING THIS PERIOD. THINK THERE SHOULD BE A BREAK
IN PRECIP CHANCES WEDNESDAY EVENING AS ISENTROPIC LIFT BECOMES LESS
ORGANIZED. OVERALL THIS FORECAST IS LOW CONFIDENCE WITH RESPECT TO
THE CIGS HEIGHTS AND TIMING OF PRECIP.
WOLTERS
&&
.PREV DISCUSSION... /ISSUED 634 PM CDT TUE MAR 20 2012/
TONIGHT/WEDNESDAY...UPPER LOW CENTERED OVER WEST TEXAS WILL
SLOWLY DRIFT EASTWARD INTO WESTERN OKLAHOMA IN THE NEXT 24 HOURS.
A SIMILAR WEATHER PATTERN COMPARED TO TODAY WILL CONTINUE...WITH
OCCASIONALLY WET CONDITIONS AND NEAR NORMAL TEMPERATURES EXPECTED.
WHILE MOST LOCATIONS WILL SEE SHOWERS AT SOME POINT
OVERNIGHT...THE MOST PROLONGED PERIODS WILL BE OVER FAR EASTERN
AND FAR SOUTHWEST PORTIONS OF THE CWA WHERE THE STRONGEST FORCING
IS PROJECTED TO RESIDE. GUIDANCE SUGGESTS DRY AIR TO WORK ITS WAY
INTO THE CWA BY WEDNESDAY MORNING...WITH A 3-6 HOUR LULL IN
PRECIPITATION. ADDITIONAL SHOWERS AND PERHAPS A THUNDERSTORM WILL
REDEVELOP AND SPREAD INTO THE CWA DURING THE AFTERNOON AS LARGE
SCALE ASCENT INCREASES OVER CENTRAL KANSAS IN ADVANCE OF THE UPPER
LOW. CHANCES FOR MORE ROBUST THUNDERSTORM ACTIVITY WILL RESIDE
EAST OF THE CWA IN THE WARM SECTOR...AND TO THE SOUTHWEST OF THE
CWA UNDERNEATH THE UPPER LOW WHERE SURFACE HEATING WILL CONTRIBUTE
TO STRONG LAPSE RATES. FLOODING CONCERNS REMAIN ON THE LOW SIDE
WITH THE ANTICIPATED QPF...WITH THE EXCEPTION OF ANDERSON AND
SOUTHEAST FRANKLIN COUNTY...WHERE 2-3 INCHES OF RAIN HAVE ALREADY
FALLEN. SOME MINOR RIVER FLOODING MAY BE POSSIBLE. TEMPERATURES
TONIGHT WILL ONLY FALL INTO THE LOWER 50S. HIGHS ON WEDNESDAY WILL
WARM INTO THE UPPER 50S TO LOWER 60S. BLAIR
EXPECT CHANCE OF PRECIP ACROSS THE AREA THROUGH WEDNESDAY NIGHT AND
THURSDAY...WITH POSSIBLY SOME ISOLATED THUNDER ON THURSDAY
AFTERNOON AS COLDER TEMPERATURES ALOFT UNDER THE UPPER LOW HELP
CREATE A FEW HUNDRED JOULES OF INSTABILITY. PERIODS OF RAIN ALSO
EXPECTED TO KEEP OVERNIGHT LOWS IN THE 40S AND DAYTIME HIGHS IN
THE LOWER 60S. EXPECT IT TO BE A FEW DEGREES WARMER IN EASTERN
COUNTIES WHERE WARMER AIR IS WRAPPING BACK INTO THE SYSTEM.
RELATIVELY GOOD AGREEMENT IN BRINGING RAIN CHANCES TO AN END FROM
WEST TO EAST ACROSS THE ARE BY FRIDAY AFTERNOON AND ANTICIPATE A
SIMILAR TEMPERATURE REGIME PERHAPS A FEW DEGREES WARMER AS SKIES
CLEAR.
AREA UNDER SLIGHTLY COOLER HIGH PRESSURE BEHIND THE LOW BUT IS
ALSO UNDER A BUILDING UPPER LEVEL RIDGE...AND EXPECT SUNSHINE TO
GET AREA BACK INTO THE 70S. INCREASE IN MIXING AND SURFACE FLOW
SHOULD RAISE HIGHS TO THE MIDDLE 70S BY SUNDAY. AS UPPER FLOW
TRANSITIONS TO SOUTHWESTERLY WITH NEXT TROF APPROACHING... HIGHS
MAY REACH TOWARD 80 BY MONDAY. HIGHS TUESDAY DEPENDENT ON WHETHER
FRONT MOVING IN FROM THE NORTHERN PLAINS MAKES IT THIS FAR SOUTH.
HAVE GONE SLIGHTLY COOLER WITH JUST SLGT CHANCE POPS ATTM. 67
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PADUCAH KY
726 PM CDT THU MAR 22 2012
.UPDATE...
ISSUED AT 710 PM CDT THU MAR 22 2012
MINOR VORTICITY LOBE/CENTER APPEARED TO BE GENERATED OVER
SOUTHWEST KY/EXTREME SOUTHERN IL NEAR KPAH BETWEEN 5-6 PM CDT.
THIS FEATURE...WELL DEPICTED BY THE 3KM HRRR 1KM AGL REFLECTIVITY
SHOULD CONTINUE TO MOVE NORTHEAST THROUGH 10 PM ACROSS SOUTHERN
IL. THERE MAY BE SOME REGENERATION OF PRECIPITATION AS THIS
FEATURE MOVE NEAR THE CONFLUENCE OF THE WABASH/OHIO RIVERS NEAR
SOUTHWEST INDIANA EARLY THIS EVENING. KEPT A MENTION OF
POP/WEATHER IN THIS AREA...BUT MAY NEED TO RE-ADJUST AS THE
BOUNDARY LAYER STABLIZES AND A WEAK LLJ SET UP.
ABUNDANT MOISTURE NEAR THE SURFACE AND A STABILIZING BOUNDARY
LAYER WILL LIKELY LEAD TO SOME FOG GENERATION AFTER MIDNIGHT. AT
THE CURRENT TIME...THE MENTION OF FOG IS WELL COVERED...BUT PLAN
TO SEE WHERE THE GREATEST VISIBILITY RESTRICTIONS WILL BE FOR THE
MID-EVENING UPDATE.
WITH THE UPPER LOW AND SHARPER LAPSE RATES APPROACHING WITH THE
SOUTHWEST MO CONVECTIVE ACTIVITY...KEPT A NARROW BAND OF ISOLATED
TO SCATTERED THUNDERSTORMS MENTIONED OVER THE WESTERN FOUR COUNTIES
OF SOUTHEAST MO THIS EVENING /MAINLY POPLAR BLUFF-GREENVILLE
WESTWARD/.
PLAN TO HAVE A LITTLE MORE DETAILED LOOK AT THUNDERSTORM/HAIL/WIND
POTENTIAL FOR FRIDAY. THE CURRENT SPC OUTLOOK AREA FOR DAY 2 LOOKS
FAIRLY GOOD...WITH THE TIME OF GREATEST CONCERN LIKELY RANGE
BETWEEN 16Z-22Z /11 AM -5 PM CDT/ ALONG AND EAST OF A KPAH-KSAR-
KMVN LINE.
&&
.SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT)
N-S BAND OF SHOWERS SHIFTING SLOWLY TO THE EAST...A LITTLE FASTER
THAN ORIGINALLY EXPECTED...SO FRONTAL BOUNDARY OBVIOUSLY ON THE
MOVE. SOME DEVELOPMENT WEST OF THE MAIN BAND...BUT NOT FILLING IN TOO
WELL AT THE MOMENT.
MAIN BAND OF PRECIP SHOULD CONTINUE ITS EASTWARD MOVEMENT OVERNIGHT...
HOWEVER BY LATE TONIGHT THE LEADING EDGE OF PRECIP ASSOCIATED WITH
THE PARENT UPPER LOW IS EXPECTED TO BE MOVING INTO THE WESTERN
SECTIONS OF OUR CWA. IF SKIES REMAIN CLEAR TO MOSTLY CLEAR OVERNIGHT
BETWEEN THE TWO AREAS OF PRECIP...WITH WET SOIL AND LIGHT TO CALM
WINDS...AREAS OF FOG WILL LIKELY DEVELOP...SO ADDED IT.
THE COMBINATION OF THE PARENT UPPER LOW MOVING ACROSS OUR CWA
FRIDAY...STEEP MID LEVEL LAPSE RATES...AND COLD AIR ALOFT WILL
LIKELY GENERATE THUNDERSTORM DEVELOPMENT...WITH THERE BEING A
THREAT FOR LARGE HAIL PRODUCTION...ESPECIALLY ACROSS THE NORTHERN
HALF OF THE CWA.
FRIDAY NIGHT PRECIP CHANCES WILL DIMINISH FROM WEST TO EAST AS THE
UPPER MOVES FARTHER AWAY FROM OUR CWA.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
SHOWERS WILL LINGER ACROSS THE LOWER OHIO VALLEY ON SATURDAY AS THE
UPPER LOW SLIDES SOUTHEAST ACROSS NORTHEAST PORTIONS OF THE PADUCAH
FORECAST AREA. DUE TO THE PROXIMITY OF THE LOW...THUNDERSTORMS WILL
REMAIN POSSIBLE ACROSS THE EASTERN THIRD OF THE FA...WITH SOME SMALL
HAIL NOT OUT OF THE QUESTION. BY SATURDAY NIGHT...JUST A FEW
SHOWERS WILL BE POSSIBLE ACROSS EASTERN THIRD OF THE FA.
AN UPPER LEVEL RIDGE WILL BUILD ACROSS THE SOUTHERN PLAINS SUNDAY
AND SLIDE EAST INTO EARLY NEXT WEEK. THIS WILL KEEP CONDITIONS DRY
WITH TEMPERATURES 10 TO 15 DEGREES ABOVE NORMAL.
GFS AND ECMWF SHOW A LOW PRESSURE SYSTEM SLIDING FROM THE NORTHERN
PLAINS INTO THE NORTHERN GREAT LAKES REGION LATE TUESDAY INTO
WEDNESDAY. THIS LOW WILL BRING A COLD FRONT INTO THE AREA TUESDAY
NIGHT INTO THURSDAY. BOTH MODELS PRODUCE QPF...THOUGH GFS PRODUCES
MORE SIGNIFICANT QPF TUESDAY NIGHT INTO WEDNESDAY NIGHT...WHILE THE
ECMWF HOLDS OFF ON A LITTLE MORE SUBSTANTIAL QPF UNTIL THURSDAY WHEN
IT BRINGS THE FRONT BACK NORTH. IN EITHER CASE...AT LEAST SOME
CHANCE POPS LOOK REASONABLE ACROSS NORTHERN PORTIONS OF THE FA
TUESDAY NIGHT...AND ACROSS THE ENTIRE FA WEDNESDAY INTO WEDNESDAY
NIGHT. WENT WITH JUST SOME SMALL POPS ACROSS NORTHEAST AND SOUTHERN
PORTIONS ON THURSDAY FOR NOW UNTIL MODELS BECOME MORE DEFINITIVE
WITH TIMING AND FRONTAL PLACEMENT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 710 PM CDT THU MAR 22 2012
VERY DIFFICULT 00Z FRIDAY TAF FORECAST PACKAGE...AS UPPER LOW
CENTER MOVES CLOSER TO THE WFO PAH FORECAST AREA. MAIN DIFFICULTY
WILL BE THE AMOUNT OF FOG/LOW CEILINGS DEVELOP OUTSIDE OF
CONVECTIVE ACTIVITY AT KCGI/KPAH...AND WHETHER CURRENT SHOWERS
WILL MOVE EAST ENOUGH THIS EVENING TO IMPACT KEVV AND KOWB. WITH
THE CONVECTIVE ACTIVITY EXPECTED NEAR KEVV AND POSSIBLY
KOWB...ADDED A MENTION OF IFR CEILINGS AND VISIBILITIES. THE OTHER
CHALLENGE FOR KCGI/KPAH WILL BE THE DEGREE OF IFR/LIFR
VISIBILITIES AND CEILINGS THAT MAY OCCUR AS THE SKIES CLEAR OUT
AND THE FOG DEVELOPS...FOLLOWED BY LOW CLOUDS ASSOCIATED WITH THE
BROAD LIFT THROUGH THE BOUNDARY LAYER AS THE UPPER LOW APPROACHES.
ANTICIPATE SOME ADJUSTMENTS AND MODIFICATIONS THROUGH THE EVENING
BASED ON PRECIPITATION AND VISIBILITY TRENDS THIS EVENING AND
OVERNIGHT.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...SMITH
SHORT TERM...JP
LONG TERM....RST
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1000 AM EDT WED MAR 21 2012
.SYNOPSIS...
A STRONG UPPER LEVEL DISTURBANCE OVER VIRGINIA WILL INCREASE THE
RISK FOR SCATTERED SHOWERS AND THUNDERSTORMS ACROSS CENTRAL NC
THROUGH THURSDAY. WEAK HIGH PRESSURE WILL EXTEND ACROSS THE AREA ON
FRIDAY BEFORE ANOTHER AREA OF LOW PRESSURE BRINGS ANOTHER
CHANCE FOR SHOWERS AND THUNDERSTORMS FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM WEDNESDAY...
VISIBILITIES ARE STEADILY IMPROVING OVER THE NORTHERN PIEDMONT AND
THE DENSE FOG ADVISORY WILL BE ALLOWED TO EXPIRE AT 10 AM. AN AREA
OF SHOWERS EXTENDING FROM EDGECOMBE COUNTY TO JOHNSTON COUNTY
APPEARS TO BE ON THE SOUTHERN PERIPHERY OF A DISTURBANCE PASSING
THROUGH SOUTHEAST VA. THE RAIN HAS BEEN PERSISTENT ENOUGH FOR AN
URBAN/SMALL STREAM FLOOD ADVISORY...BUT RATES HAVE BEEN LOW ENOUGH
THAT ANY FLOODING SHOULD BE VERY MINOR. AS THE DISTURBANCE MOVES
OFFSHORE IN THE NEXT COUPLE OF HOURS...MOST OF THE SHOWER ACTIVITY
SHOULD DIMINISH.
FOR TODAY...MOST OF THE FORECAST WILL REMAIN UNCHANGED SINCE THE
OVERALL PATTERN HAS BEEN PERSISTENT THAT PAST COUPLE OF DAYS. PW
VALUES ARE STILL NEAR 1.25 INCHES OR 200 PERCENT OF NORMAL EAST OF
THE UPPER RIDGE AXIS...WHICH IS OVER THE TN/OH VALLEYS THIS
MORNING. THE CYCLONIC CIRCULATION THAT HAS BEEN LINGERING AROUND
THE MASON-DIXON LINE WILL DROP SOUTH AND EAST TODAY ACROSS EASTERN
VA AND NORTHEAST NC AND WILL PROVIDE THE MAIN FOCUS FOR CONVECTION
THIS AFTERNOON. IN PARTICULAR...THERE IS ONE WEAK PERTURBATION
NOTED IN WATER VAPOR IMAGERY OVER CENTRAL VA THAT WE WILL WATCH AS
IT ROTATES SOUTH AROUND THE MAIN VORT MAX. LATEST HRRR RUNS SHOW
CONVECTION FIRING BY 18-20Z ACROSS THE NORTHERN PIEDMONT...ALTHOUGH
THE HRRR ALONG WITH OTHER HI-RES MODELS HAVE PERFORMED
INCONSISTENTLY IN THIS PATTERN....SO ONLY SO MUCH WEIGHT CAN BE PUT
ON THOSE SOLUTIONS. GIVEN THAT UPPER LEVEL FOCUS APPROACHING FROM
THE NORTH...HIGHEST PROBABILITIES OF SHOWERS AND STORMS STILL SEEM
NECESSARY ACROSS THE NORTH. CONCERNING SEVERE POTENTIAL....THE MAIN
DIFFERENCE FOR TODAY IS THAT OBSERVED MID-LEVEL LAPSE RATES ARE
WEAKER THAN THEY HAVE BEEN THE PAST COUPLE OF DAYS...WITH SPC
MESOANALYSIS AND AREA RAOBS SHOWING LESS THAN 6.5 C/KM FROM
700-500MB. STILL...WITH VARIABLE CLOUD COVER ACROSS THE AREA AND
STRONG HEATING THIS AFTERNOON...MLCAPE VALUES SHOULD APPROACH 1000
J/KG...SO MARGINALLY SEVERE HAIL MAY STILL BE A THREAT IN THE
STRONGEST STORMS. HIGHS SHOULD REACH THE MID 70S TO AROUND
80...GENERALLY WARMEST IN THE SOUTH WHERE CONVECTIVE COVERAGE WILL
BE LEAST. -SMITH
TONIGHT...EXPECT CONVECTION TO SLOWLY WANE WITH LOSS OF HEATING BUT
MAY LINGER INTO THE OVERNIGHT HOURS EAST OF HIGHWAY 1 WHERE LOW-MID
LEVEL CONFLUENCE (THOUGH WEAK) EXPECTED TO PERSIST. WHERE SKIES
CLEAR...EXPECT AREAS OF FOG WITH LOCALLY DENSE FOG PROBABLE. MIN
TEMPS STILL MILD FOR LATE MARCH IN THE 50S TO NEAR 60.
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 330 AM WEDNESDAY...
APPEARS BEST FOCUS FOR CONVECTIVE INITIATION/DEVELOPMENT WILL BE
ACROSS THE EASTERN COUNTIES AS MID LEVEL TROUGH EDGES EWD TOWARD THE
COAST. THIS WILL RESULT IN A DEVELOPING DOWNSLOPE FLOW IN THE
WESTERN PIEDMONT...POTENTIALLY LIMITING CONVECTIVE DEVELOPMENT IN
THIS REGION. THUS PLAN TO GRADUATE POPS FROM SLIGHT CHANCE WEST (TO
ACCOUNT FOR ANY CONVECTION THAT FIRES ON THE HIGHER TERRAIN THEN
DRIFT SEWD INTO THE WESTERN PIEDMONT) TO SOLID CHANCE (40-50
PERCENT) COASTAL PLAIN.
SEVERE PARAMETERS STILL RATHER WEAK THOUGH A STRONG STORM PROBABLE
IN THE COASTAL PLAIN WITH HAIL AND FREQUENT LIGHTNING THE MAIN
SEVERE WEATHER ATTRIBUTES.
TEMPS REMAIN UNSEASONABLY WARM WITH A BETTER POTENTIAL FOR PLACES IN
THE PIEDMONT TO REACH/EXCEED 80 DEGREES DUE TO A DECREASE IN
CONVECTIVE COVERAGE.
THURSDAY NIGHT...CONVECTION SHOULD DISSIPATE PRIOR TO MIDNIGHT IN
THE COASTAL PLAIN AS MID LEVEL TROUGH PUSHES TO THE COAST AND
MID/UPPER LEVEL RIDGE NOSES INTO REGION. SHOULD SEE AREAS OF FOG
DEVELOP REGIONWIDE WITH POTENTIAL FOR DENSE FOG...ESPECIALLY IN THE
COASTAL PLAIN...SANDHILLS AND EASTERN PIEDMONT. MIN TEMPS ONCE AGAIN
UPPER 50S TO NEAR 60.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...
MID/UPPER LOW FROM THE PLAINS/MIDWEST WILL SLOWLY TRANSLATE EASTWARD
ON FRIDAY... ALLOWING THE MID/UPPER LEVEL RIDGE TO SLOWLY SHIFT
ACROSS THE AREA. THIS SHOULD LEAD TO ONLY A SLIGHT CHANCE FOR
SHOWERS AND THUNDERSTORMS ACROSS MOST OF THE AREA FOR FRIDAY (WITH
ONLY THE NW IN THE LOW END CHANCE CATEGORY AS THE MID/UPPER RIDGE
SLOWLY SHIFTS TO THE EAST). GIVEN AFTERNOON LOW LEVEL THICKNESS
VALUES IN THE 1390S AND STATISTICAL GUIDANCE SHOWING HIGHS AREAWIDE
IN THE LOWER TO MID 80S... WILL INCREASE HIGH TEMPS A DEGREE OR TWO
ACROSS MOST AREAS... RESULTING HIGH TEMPS ON FRIDAY TOPPING OUT IN
THE LOWER TO PERHAPS MID 80S.
WILL RAISE POPS ON FRIDAY NIGHT GIVEN INCREASING LARGE SCALE LIFT AS
THE UPPER LEVEL LOW CONTINUES TO APPROACH FROM THE WEST ALONG WITH
THE POTENTIAL FOR A PRE-FRONTAL BAND OF SHOWERS AND STORMS MOVING
INTO THE AREA FROM THE WEST. THIS YIELDS LIKELY POPS FOR THE
NORTHWESTERN/WESTERN PIEDMONT... TO CHANCE ELSEWHERE OVERNIGHT.
HOWEVER... THE BEST CHANCE FOR SHOWERS AND STORMS APPEARS TO BE ON
SATURDAY INTO SATURDAY EVENING AS AN ASSOCIATED COLD/OCCLUDED FRONT
IS EXPECTED TO MOVE ACROSS THE AREA. THUS... GIVEN MODELS APPEAR TO
BE COMING INTO BETTER AGREEMENT ON THE TIMING AND TRACK OF THE
SYSTEM... WILL RAISE POPS TO LIKELY FOR THE ENTIRE AREA ON SATURDAY
INTO SATURDAY EVENING. GIVEN THE INCREASE DEEP LAYER SHEAR (~30-50
KTS) ALONG WITH POTENTIAL FOR 300-800 J/KG MLCAPE EXPECT WE WILL
HAVE THE POTENTIAL FOR AN ORGANIZED BAND OF SHOWERS AND STORMS
DEVELOP/MOVE INTO THE AREA... WITH THE POTENTIAL FOR SOME SEVERE
STORMS. HOWEVER... QUESTIONS REMAIN IN EXACTLY HOW MUCH SURFACE
HEATING WE WILL SEE ON SATURDAY ALONG WITH THE TIMING OF THE FRONT.
THUS... WILL KEEP MENTION OF SEVERE POTENTIAL FOR SATURDAY/SATURDAY
EVENING THE SAME IN THE HWO. LOW TEMPS ON SATURDAY MORNING ARE
EXPECTED TO BE IN THE LOWER TO PERHAPS MID 60S. HIGHS ON SATURDAY
WILL BE GREATLY DEPEND ON THE TIMING OF THE FRONT AND AMOUNT OF
CLOUD COVER. GIVEN LATEST MODEL GUIDANCE... WILL TREND TEMPS DOWN A
DEGREE OR TWO. THIS YIELDS HIGHS SATURDAY IN THE LOWER 70S NW TO THE
UPPER 70S EAST.
THE MAIN SURFACE COLD FRONT IS EXPECTED TO MOVE TO THE EAST OF THE
AREA BY SATURDAY NIGHT/SUNDAY MORNING. HOWEVER... THE MID/UPPER LOW
IS PROGGED TO MOVE ACROSS OUR REGION SUNDAY... POTENTIALLY YIELDING
SOME INSTABILITY SHOWERS/STORMS AS MID LEVEL LAPSE RATES STEEPEN.
GIVEN THE TRACK OF THE MID/UPPER LEVEL LOW WILL BE IMPORTANT WITH
REGARD TO WHERE THE BEST POTENTIAL FOR SHOWERS AND ISOLATED STORMS
WILL CONTINUE TO JUST ADVERTISE CHANCE POPS AREAWIDE... WITH
CURRENTLY OUR NORTHERN COUNTIES STANDING THE BEST CHANCE OF SEEING
SOME PRECIP. LOWS SUNDAY MORNING RANGING FROM THE LOWER 50S NW TO
THE UPPER 50S EAST. HIGHS SUNDAY GENERALLY IN THE LOWER TO MID 70S.
MID/UPPER LEVEL RIDGING IS EXPECTED TO BUILD BACK INTO THE AREA FOR
EARLY NEXT WEEK... WHILE SURFACE HIGH PRESSURE BUILDS ACROSS THE
AREA. THIS WILL RESULT IN A RETURN TO DRY WEATHER WITH LOWER
DEWPOINTS. EXPECT HIGHS EARLY NEXT WEEK TO BE IN THE LOWER TO MID
70S... WITH LOWS IN THE UPPER 40S TO LOWER 50S.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 740 AM WEDNESDAY...
PERIODS OF SHOWERS AND A FEW THUNDERSTORMS WILL OCCUR ACROSS CENTRAL
NC THROUGH THURSDAY NIGHT WITH THE HIGHEST RISK/GREATEST COVERAGE
OF CONVECTION OCCURRING DURING THE LATE AFTERNOON AND EVENING HOURS.
MVFR CEILINGS AND VISIBILITY WILL OCCUR IN VICINITY OF THE SHOWERS
AND STORMS.
OTHERWISE...VARIABLE AVIATION CONDITIONS THIS MORNING WITH MAJORITY
OF THE AREA EXPERIENCING MVFR VISIBILITY THOUGH IFR/LIFR BEING
OBSERVED IN THE FAR NORTHERN AND WESTERN PIEDMONT. THE FOG/STRATUS
SHOULD LIFT AND DISSIPATE LEADING TO HIGH END MVFR/LOW END VFR
CEILINGS IN THE LATE MORNING-EARLY AFTERNOON. ANOTHER ROUND OF
IFR/LIFR FOG AND STRATUS IS EXPECTED EARLY THURSDAY MORNING. WINDS
THROUGH THURSDAY NIGHT WILL BE LIGHT AND VARIABLE.
CONVECTION EXPECTED TO BE LIMITED FRIDAY AFTERNOON AS AN AREA OF
HIGH PRESSURE EXTENDS ACROSS THE CAROLINAS. THERE WILL LIKELY BE
ANOTHER BOUT OF EARLY MORNING IFR FOG/STRATUS.
A LOW PRESSURE SYSTEM WILL APPROACH FROM THE WEST FRIDAY NIGHT AND
CROSS THE REGION LATE SATURDAY INTO SUNDAY. THIS WEATHER SYSTEM WILL
BRING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS AND ASSOCIATED MVFR
CONDITIONS TO CENTRAL NC LATE FRIDAY NIGHT THROUGH SATURDAY NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR
NCZ007>010-023-024.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS/SMITH
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
139 AM EDT WED MAR 21 2012
.SYNOPSIS...
SUMMER-LIKE CONDITIONS...WARM TEMPERATURES ALONG WITH A FEW
THUNDERSTORMS WILL CONTINUE FOR THE NEXT FEW DAYS. A MORE
SIGNIFICANT SPRING-LIKE SYSTEM WILL MOVE ACROSS THE AREA THIS
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1030 PM TUESDAY...SURFACE HIGH PRESSURE WELL OFF THE CAROLINA
COAST IS PRODUCING A LIGHT SOUTH TO SOUTHEASTERLY WIND ACROSS THE
AREA WITH UNSEASONABLY MILD TEMPERATURES AND HIGH DEWPOINTS. AT AND
ABOVE THE 700 MB LEVEL A STRONG RIDGE EXISTS ALONG THE APPALACHIANS
WITH NORTHERLY MID AND UPPER LEVEL FLOW RUNNING FROM THE MID-
ATLANTIC INTO THE COASTAL SOUTHEAST STATES. A SERIES OF UPPER
DISTURBANCES IN THIS COOL FLOW ALOFT HAVE CREATED WAVES OF SHOWERS
AND THUNDERSTORMS OVER THE PAST FEW DAYS SPACED ROUGHLY 12-18 HOURS
APART. THE LATEST WAVE CURRENTLY IS MOVING SOUTH ACROSS CENTRAL
NORTH CAROLINA AND MAY BRING SHOWER OR THUNDERSTORM ACTIVITY TO
INLAND PORTIONS OF OUR FORECAST AREA LATE THIS EVENING AND
OVERNIGHT. THE LATEST THREE RUNS OF THE HRRR MODEL SHOW CONVECTION
DISSIPATING JUST BEFORE REACHING THE LUMBERTON/ BENNETTSVILLE
VICINITY. LATEST RADAR TRENDS SEEM TO SUPPORT THIS IDEA AS WELL.
THEREFORE WE HAVE LOWERED POPS TO NO HIGHER THAN 30 PERCENT ACROSS
THE BENNETTSVILLE AREA. 20 PERCENT (SLIGHT CHANCE) POPS ARE BEING
RESTRICTED TO AREAS NORTH OF FLORENCE AND MARION...AND WEST OF
WHITEVILLE AND WHITE LAKE. OFFSHORE CONVECTION ALONG THE WESTERN
WALL OF THE GULF STREAM SHOULD HAVE LITTLE LUCK CROSSING THE COLD
NEARSHORE WATERS AND SHOULD NOT AFFECT LAND TONIGHT.
NO CHANGES HAVE BEEN MADE TO LOW TEMPERATURE FORECASTS...WITH UPPER
50S FORECAST FOR MOST AREAS. FOG POTENTIAL IS LESS THAN THE PREVIOUS
TWO NIGHTS WITH CLOUDINESS EXPECTED TO INCREASE LATER THIS EVENING
WITH THE APPROACHING UPPER DISTURBANCE...BUT POTENTIAL IS STILL HIGH
ENOUGH TO WARRANT THE INCLUSION OF PATCHY OR AREAS OF FOG IN THE
FORECAST. WE`RE ALREADY SEEING SOME MINOR RESTRICTIONS TO VISIBILITY
IN GEORGETOWN AND CONWAY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...THE HIGH AMPLIFIED RIDGE OVER THE EAST COAST
IS SLOWLY BE PINCHED OFF AS A UPPER LEVEL LOW NORTH OF THE
DELMARVA. THIS LOW WILL SLOWLY SHIFT SOUTH ALONG THE COAST. THIS
WILL BRING A CONTINUED CHANCE OF THUNDERSTORMS THROUGH MUCH OF THE
PERIOD. THE TIMING OF THE WEAK SHORTWAVES IS PROBLEMATIC THUS HAVE
KEPT IN THUNDERSTORMS FOR MOST OF THE PERIOD. AT THE SURFACE
ONSHORE FLOW WILL PROVIDE MOISTURE IN THE LOWER LEVEL AND THE
UPPER LEVEL WILL INCREASE THE MOISTURE THROUGH THE ATMOSPHERIC
COLUMN THROUGH OVERNIGHT FRIDAY THUS THE CHANCE OF THUNDERSTORMS
THROUGHOUT THE PERIOD.
TEMPERATURES WILL REMAIN IN THE MID 70S NEAR THE COAST TO AROUND
80 DEGREES INLAND LOWS WILL FALL TO THE UPPER 70S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 PM TUESDAY...AMPLIFIED UPPER RIDGE STILL IN PLACE ON FRIDAY
BUT PROBABLY NOT FOR MUCH LONGER AS CUTOFF SLOWLY BOWLS ITS WAY
ACROSS THE OH/TN VALLEYS. MUCH OF FRIDAY AFTERNOON LOOKS DRY THEN
BUT SOME HEIGHT FALLS MAY IMPINGE UPON THE REGION FROM THE WEST
TOWARDS EVENING. HIGHEST RAIN CHANCES MAY COME FRIDAY NIGHT INTO
SATURDAY AS RIBBON OF HIGHEST LOW LEVEL RH COMES THROUGH. CUTOFFS
ARE ALWAYS TRICKY TO TIME SO THE FORECAST WILL BE A BIT MORE
BROAD-BRUSHED. SOME GUIDANCE IS A LITTLE SLOWER ANYWAY AND THIS IS
USUALLY A GOOD SOLUTION WHEN THE DOWNSTREAM RIDGE IS AMPLIFIED.
SERIES OF DRY SLOTS AND MOISTURE CHANNELS KEEP CROSSING THE AREA
THROUGH SUNDAY ACCORDING TO GUIDANCE SO ONCE AGAIN THE FORECAST WILL
BE HARD-PRESSED TO CONTAIN MUCH SPECIFICITY BEYOND SCATTERED POPS
FOR MOST OF THE WEEKEND. TEMPERATURES WILL BE HELD DOWN CLOSE TO
CLIMO BY BOTH CLOUD COVER AND SOME COOL AIR ADVECTION ESPECIALLY
FOLLOWING SUNDAY SURFACE FROPA. REMAINDER OF THE PERIOD WILL STILL
FIND THE UPPER TROUGH SWINGING OFF THE COAST. HEIGHT RISES AND
CONTINUED COOL AND DRY AIR ADVECTION WILL ROUND OUT THE LONG TERM
WITH MINIMAL CLOUD COVER AND NEAR SEASONABLE TEMPERATURES.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...EXPECT VFR THROUGH THE VALID PERIOD...WITH EXCEPTION OF
POSSIBLE MVFR/IFR DURING THE EARLY MORNING HOURS DUE TO POTENTIAL
FOG DEVELOPMENT. ANTICIPATE CLOUDS TO FILL IN ASSOCIATED WITH THE
LEFTOVER ACTIVITY FROM EARLIER NORTH OF OUR AREA. THIS COULD INHIBIT
ANY FOG DEVELOPMENT POSSIBLE AFTER 9Z. SFC WINDS WILL BE LIGHT
OVERNIGHT...AND THIS WITH LOW LEVEL MOISTURE COULD HELP DEVELOP
FOG...THOUGH BOUNDARY WINDS WILL BE A BIT STRONGER. FOR NOW HAVE
KEPT MVFR/POTENTIAL IFR AT ALL TERMINALS...WITH GREATEST POTENTIAL
AT INLAND SITES AND KCRE GIVEN LOCAL CLIMATOLOGICAL EFFECTS. AFTER
14Z...ANTICIPATE ANY LINGERING FOG TO QUICKLY DISSIPATE GIVING WAY
TO VFR BKN/OVC SKIES. WINDS THROUGHOUT THE DAY WILL BE
SOUTHEAST...WITH SUSTAINED WINDS AOB 10 KTS THROUGH THE VALID TAF.
CANNOT RULE OUT ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
LATER TODAY.
EXTENDED OUTLOOK...MORNING FOG/MVFR AND SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS IN THE AFTERNOON THROUGH FRIDAY. BETTER CHANCE FOR
CONVECTION SATURDAY AND SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM TUESDAY...HIGH PRESSURE WELL OFFSHORE IS PROVIDING A
LIGHT SOUTH TO SOUTHEASTERLY WIND ACROSS THE WATERS THIS EVENING.
LATEST HIGH-RESOLUTION MODELS SHOW THE GULF STREAM SHOWER/T-STORM
ACTIVITY MAY DRIFT IN AS CLOSE AS 15-20 MILES FROM SHORE AFTER
MIDNIGHT IN THE CAPE FEAR AREA WATERS...BUT THE SOUTH CAROLINA
COASTAL WATERS SHOULD REMAIN RAIN-FREE TONIGHT. SEAS AVERAGE 2 FEET
CURRENTLY PRIMARILY IN SOUTHEAST SWELL.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...SOUTHEASTERLY FLOW WILL CONTINUE THROUGH THE
PERIOD WITH WINDS SPEEDS AROUND 10 T0 15 KNOTS. THE LOCAL SHALLOW
WAVE MODEL INITIALIZED OFF FORECAST WIND FIELD IS SHOWING WAVE
HEIGHTS RANGING BETWEEN 2 TO 4 FEET.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 3 PM TUESDAY...SOUTH TO SOUTHWEST WINDS ON FRIDAY AS HIGH
PRESSURE THAT HAD BEEN WELL OFF THE DELMARVA COAST DROPS SOUTH INTO
A MORE SUMMER-LIKE BERMUDA HIGH POSITION. SEAS REMAIN QUITE SMALL
AND MAY EVEN HAVE A BIT OF A NEAR SHORE VS OFFSHORE RANGE OPEN UP AS
THE FLOW BECOMES MORE COAST-PARALLEL. THE APPROACH OF SOME WEAK
SURFACE TROUGHINESS FROM THE WEST ASSOCIATED WITH A LARGE UPPER
LEVEL STORM SYSTEM MAY INTRODUCE A SLIGHT INCREASE IN THE
GRADIENT/WINDS FRIDAY NIGHT INTO SATURDAY. THE BUILDING OF SEAS WILL
TEND TO BEGIN WELL OUT TO SEA BUT A SIMILAR UPTICK SHOULD BE NOTED
ALONG THE OUTER REACHES OF THE 20NM FORECAST ZONES LATER IN THE DAY
SATURDAY. SCEC HEADLINES MAY BE NEEDED AS 5 FOOTERS START AFFECTING
SAID AREAS. SATURDAY NIGHT OR SUNDAY FROPA TO BRING A FURTHER
INCREASE IN SPEED AS THE DIRECTION STARTS TO VEER TO MORE OFFSHORE
TRAJECTORY. FOR NOW THIS MAY PRECLUDE AN ADVISORY BUT ITS TOUGH TO
RULE OUT SO FAR IN ADVANCE EITHER.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...REK/RGZ
SHORT TERM...DRH
LONG TERM...MBB
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
553 PM EDT WED MAR 21 2012
.SYNOPSIS...
A STRONG UPPER LEVEL RIDGE WILL CONTINUE THE IMPRESSIVE STRETCH OF
UNSEASONABLY MILD EARLY SPRING WEATHER THROUGH THE END OF THE WORK
WEEK. A DEEP MID-LEVEL CYCLONE AND ASSOCIATED SURFACE LOW PASSING
TO THE SOUTH OF PENNSYLVANIA WILL BRING RAIN AND COOLER TEMPERATURES
FOR THE UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
STRATUS CONTINUES TO HOLD TOUGH ACROSS MUCH OF CENTRAL PA THIS
AFTERNOON AS SERLY FLOW TRANSPORTS MOISTURE NWD. CENTER OF UPPER
LOW HAS SHIFTED SOUTH AND THE INSTABILITY SHOULD STAY TO THE SOUTH
OF THE REGION SO ANY CONVECTION IS EXPECTED TO BE EVEN LESS IN
COVERAGE THAN YESTERDAY...WHICH WAS VERY ISOLATED...AND CONFINED
TO THE LOWER SUSQ VALLEY. EVENTUAL CLEAR SKIES TOWARD EVENING WILL
ALLOW FOR REDEVELOPMENT OF WIDESPREAD FOG AND STRATUS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
THE UPPER LEVEL PATTERN WILL CONTINUE TO BE DOMINATED BY AN
ANOMALOUS H5 RIDGE...BUT THIS FEATURE WILL GRADUALLY LOSE ITS
GRIP ON THE REGION BY THE END OF THE PERIOD. THE PESKY/WEAK UPPER
AIR DISTURBANCE MEANDERING SWD THRU VA UNDER THE RIDGE WILL SLIDE
OFF THE SOUTHERN MID-ATLC/NC COAST ON THURSDAY. A S/W TROUGH
CROSSING NRN QUE WILL SEND A BACKDOOR COLD FRONT SWD THRU THE
NORTHEAST STATES ON FRIDAY...WHILE A DEEP MID-LEVEL CYCLONE/CLOSED
H5 LOW MOVES SLOWLY EWD FROM THE PLAINS THROUGH THE MID MS VLY BY
SATURDAY MORNING. BOTH OF THESE FEATURES WILL GRADUALLY LOWER
HEIGHTS AND HELP BREAK DOWN THE HIGH AMPLITUDE UPPER RIDGE IN THE
EAST. THE BULK OF THE PERIOD WILL BE DRY AND VERY WARM FOR THIS
TIME OF YEAR WITH HIGHS WELL INTO THE 70S/20+ DEGREES ABV AVG. AN
ISOLD SHOWER WILL BE PSBL OVR THE N-CENTRAL MTNS AND SRN POCONOS
ON FRI AFTN NEAR THE BACKDOOR COLD FRONT...WITH THE THREAT OF
MORE WIDESPREAD RAINS INCREASING FROM WEST TO EAST FRI NGT INTO
EARLY SAT AS THE CLOSED LOW SHIFTS EWD INTO THE MID OH VLY. HPC QPF
LEANED TWD A BLEND OF THE ECMWF AND UKMET SOLNS AND THEREFORE
INCREASED POPS TO LKLY CATG IN THE WEST DURING THE LAST 6HR PD FM
06-12Z SAT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
MODELS REMAIN IN VERY GOOD AGREEMENT THROUGH SUNDAY NIGHT. LARGE
UPPER LOW OVER CENTRAL U.S. WILL CONTINUE TO SLOWLY DRIFT EASTWARD
INTO OHIO VALLEY BY SAT AS SFC RIDGE OVER PA GRADUALLY BREAKS
DOWN. SYSTEM REMAINS VERY OCCLUDED AND BEGINS TO OPEN UP SAT NIGHT
AS BROAD UPPER RIDGE FLATTENS TO OUR NORTH...DIRECTING CENTER OF
THE LOW SOUTHEASTWARD. BOTH ECMWF AND GFS FORECAST LOW TO SINK
INTO NORTH CAROLINA ON SUNDAY...BEFORE TURNING BACK NORTHEASTWARD
OFF THE EAST COAST.
VERY MILD TEMPERATURES WILL CONTINUE THROUGH FRIDAY NIGHT /WITH
READINGS 20-25F ABOVE NORMAL/ BEFORE UPPER LOW BRINGS IN SOME
COOLER AIR FOR THE WEEKEND...DROPPING TEMPS BACK TO ONLY ABOUT 5F
ABOVE NORMAL. COOLER TEMPS ALOFT WILL BRING INCREASE IN SHOWER
CHANCES ON FRI...WITH LIKELY SHOWERS AND ISOLATED TSTMS ON TAP FOR
SAT INTO SUN AS UPPER LOW SLIDES BY. PRECIP CHANCES DROP QUICKLY
FROM NW-SE SUN NIGHT.
BY MON...DIFFS IN GUIDANCE BECOME APPARENT WITH THE ECMWF
CONTINUING MUCH STRONGER WITH POST-SYSTEM TROUGH THAN THE
REMAINDER OF THE GUIDANCE...WHICH MAY BRING A BIT MORE OF A
COOL-DOWN THAN PREVIOUSLY ADVERTISED - THOUGH TEMPS STILL REMAIN
ABOVE NORMAL. AS RIDGE BUILDS IN MON-TUE...MOSTLY SUNNY SKIES WILL
BE THE RULE. NOTICEABLY COOLER MORNINGS AS WELL...WITH TUE MORNING
LOOKING LIKE THE CHILLIEST AS LOWS DIP INTO THE 30S AND LOWER 40S.
BUT WARMER SW FLOW RETURNS AS HEIGHTS BUILD AHEAD OF A SYSTEM FOR
LATE WEEK...PUSHING TEMPS BACK WELL ABOVE NORMAL.
&&
.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
LOW CLOUDS HAVE BEEN VERY STUBBORN TO LIFT OR SCATTER THIS
AFTERNOON. LATEST VIZ SHOTS SHOW THE NORTHERN EDGE MELTING AWAY
INTO THE CENTRAL MOUNTAINS...BUT THE RUC BRINGS THIS CLEARING TO
A HALT BETWEEN 6 AND 8 PM....BEFORE SURGING BACK NORTH OVERNIGHT.
ANOTHER ROUND OF STRATUS AND PATCHY DENSE FOG ARE IN STORE
TONIGHT...INTO TOMORROW...EXPECT IFR AND LOWER CIGS AND VSBYS BTWN
09Z-14Z TOMORROW MORNING AT MOST TAF SITES.
OUTLOOK...
THU...AM LOW CLOUDS/FOG PSBL. VFR AFTERNOON
FRI...NO SIG WX EXPECTED.
FRI NIGHT-MON...MVFR/IFR POSS IN SHRA/TSRA.
&&
.EQUIPMENT...
RADAR OUTAGE DUE TO ONGOING DUAL-POL INSTALLATION.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GARTNER/STEINBUGL
NEAR TERM...GARTNER
SHORT TERM...GARTNER/STEINBUGL
LONG TERM...RXR/STEINBUGL
AVIATION...LA CORTE/GARTNER
EQUIPMENT...LA CORTE
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1050 PM CDT THU MAR 22 2012
.DISCUSSION...
ONLY MINOR TWEAKS TO FORECAST. CLEARING IS SPREADING A LITTLE FASTER
NORTHWEST ACROSS NORTHWEST IOWA INTO SOUTHEAST SOUTH DAKOTA...SO DID
SPEED UP CLEARING JUST A TAD FROM SOUTHEAST TO NORTHWEST ACROSS CWA.
SCATTERED SHOWERS STILL PERSIST ACROSS THE NORTH...BUT BULK OF RAIN
SHOULD BE OUT OF CWA BY 06Z. FOG HAS NOT DEVELOPED AS OF YET BUT
WOULD EXPECT AT LEAST SOME PATCHY FOG AFTER MIDNIGHT. OVERALL
TEMPERATURES LOOK GOOD WITH A SLOWER FALL ACROSS NORTH AND WEST
WHERE CLOUDS PERSIST.
&&
.PREVIOUS DISCUSSION....../ISSUED AT 300 PM CDT/
UPPER LEVEL LOW ROTATING OVER KANSAS THIS AFTERNOON SHOULD SLOWLY
DRIFT EASTWARD THROUGH FRIDAY. THE WARM CONVEYOR BELT STRETCHING
FROM MISSISSIPPI INTO CENTRAL IOWA WILL CONTINUE TO DELIVER MOISTURE
TO THE AREA THROUGH THIS EVENING...SO WILL KEEP POPS INTO MAINLY THE
NORTHERN HALF OF THE CWA. THE DRY SLOT WILL PIVOT NORTH AND AID IN
SHUTTING DOWN THE RAINFALL THREAT FROM SOUTH TO NORTH DURING THE
EVENING. AS THIS OCCURS SLIGHTLY LOWER DEW POINTS WILL SPREAD IN
FROM SOUTH TO NORTH AS WELL...WHICH WILL ALLOW LOWS TO FALL A LITTLE
LOWER THAN THE LAST FEW DAYS. SOMETHING CLOSE TO 40 DEGREES NEAR THE
MISSOURI RIVER WHILE PARTS OF SOUTHWEST MINNESOTA WILL LIKELY STAY
IN THE UPPER 40S UNDER A MORE DENSE CLOUD COVER. WHILE FOG SHOULD
NOT BECOME A WIDESPREAD PROBLEM...IF SKIES CAN CLEAR MORE THAN
EXPECTED VISIBILITIES MIGHT TANK A BIT SO WILL BE SOMETHING TO WATCH
FOR. /08
CIRCULATION AROUND NORTHERN EDGE OF UPPER LOW WILL BRING SOME MID
LEVEL MOISTURE OVER THE EASTERN EDGE OF THE FORECAST AREA FRIDAY AS
THE LOW MOVES SLOWLY EAST. WHILE THERE COULD BE A CASE FOR A SLIGHT
CHANCE OF SHOWERS OR PERHAPS SPRINKLES FAR EAST FRIDAY...WEAK AND
DECREASING SUPPORT SUGGESTS THE CHANCE OF MEASURABLE RAIN IS PRETTY
LOW...SO WILL LEAVE SHOWER MENTION OUT. SKIES SHOULD BE PARTLY TO
MOSTLY SUNNY EAST OF THE FAR EAST AND TEMPERATURES WILL BEGIN THEIR
WARMING AS THE LOW LEVEL AIR SLOWLY DRIES OUT. THIS PROCESS WILL
PICK UP FOR SATURDAY AS THE LOW MOVES WELL EAST OF AREA AND RIDGING
TAKES OVER. THE MAIN EFFECT OF WEAK FRONT WHICH MOVES OVER AREA LATE
SATURDAY WILL BE TO SET UP SOUTH OF AREA AS A WEAK STATIONARY FRONT.
THIS WILL BRING SLIGHTLY COOLER AND DRIER AIR FOR SUNDAY...THOUGH
LITTLE COOLING IS EXPECTED SOUTHWEST. THIS WILL ALSO SET UP A
POTENTIAL BOUNDARY FOR CONVECTION SUNDAY NIGHT AS INCREASINGLY MOIST
AND UNSTABLE AIR STREAMS UP TO THIS BOUNDARY FROM THE SOUTH. SINCE
THIS PROCESS DOES NOT APPEAR TO MAKE THE BOUNDARY RIPE UNTIL IT IS
MOVING NORTH OVER AREA MONDAY...WILL HOLD OFF MENTION OF
THUNDERSTORMS UNTIL MONDAY AND MONDAY NIGHT AS FRONT FROM THE WEST
APPROACHES. MEANWHILE TEMPERATURES MONDAY SHOULD REBOUND TO WARMER
LEVELS AS THE WARM FRONT MOVES NORTH. TIMING OF THE COLD FRONTAL
PASSAGE MONDAY NIGHT AND TUESDAY IS STILL UNCERTAIN...BUT WITH UPPER
LOW ARRIVING FROM THE SOUTHWEST AND MOVING NORTHWEST OF
AREA...COOLING IS LIKELY TO LAG BEHIND DRYING...SO TUESDAY
TEMPERATURES COULD STILL BE FAIRLY WARM. WILL KEEP GUIDANCE LOW
CHANCE OF STORMS IN OUR EAST FOR TUESDAY. A BIT COOLER COOLER AND
DRY WEATHER LOOKS GOOD FOR WEDNESDAY THEN THE START OF WARMING AGAIN
THURSDAY. THIS WARMING PATTERN COULD CONCEIVABLY BRING A FEW
THUNDERSTORMS BUT PATTERN DOES NOT LOOK REAL FAVORABLE AND WILL
LEAVE OUT. THE ECMWF ESPECIALLY RAMRODS THE WARMING IN RAPIDLY AND
ALREADY APPEARS TO HAVE US CAPPED FOR THURSDAY. WILL KEEP THURSDAY
WARMING MODEST FOR NOW...THAT IS MODEST IN THE SENSE THAT WE ARE IN
A PATTERN WHERE EVEN OUR COOL DAYS ARE MUCH ABOVE NORMAL. / WILLIAMS
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
FOG HAS BEGUN TO DEVELOP ACROSS NORTHWEST IOWA AND IS EXPECTED TO
BECOME MORE WIDESPREAD OVER THE NEXT FEW HOURS. FOG APPEARS TO BE
DEVELOPING A FEW HOURS FASTER THAN THE HRRR OUTPUT. APPEARS AS
THOUGH CLOUD COVER WILL KEEP FOG POTENTIAL AT BAY FOR A FEW HOURS AT
KHON...BUT FOG IS EXPECTED TO IMPACT KFSD TERMINAL FIRST...THEN
EXPANDING TO KHON AND EVENTUALLY DOWN THE RIVER VALLEY IN NORTHWEST
IOWA. HAVE LOWERED EXPECTED VISIBILITIES IN THE TAFS...BUT HAVE NOT
MENTIONED QUARTER MILE YET EVEN THOUGH IT IS POSSIBLE. OVERNIGHT
CREW WILL HAVE TO WATCH THIS CLOSELY. WITH VERY WEAK WINDS ACROSS
THE AREA...FOG WILL LIKELY STICK AROUND THROUGH THE 15-17 TIME
FRAME...WHEN IT WILL GRADUALLY MIX OUT. THEREAFTER...LIGHT WINDS
AND MOSTLY CLEAR SKIES ARE EXPECTED.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1022 PM CDT THU MAR 22 2012
.UPDATE...
CONVECTION ACROSS THE PLATEAU HAS NEARLY MOVED OUT OF THE AREA
LEAVING THE MID STATE VIRTUALLY PRECIP FREE RIGHT NOW.
HOWEVER...LATEST RUC AND NAM SOLUTIONS CONTINUE TO SHOW THAT SOME
LATE NIGHT UPPER LEVEL ENERGY COULD GET CONVECTION GOING ONCE
AGAIN. WILL GO AHEAD AND DROP POPS DOWN TO THE CHC CATEGORY ACROSS
OUR EAST.
&&
.PREV DISCUSSION... /ISSUED 651 PM CDT THU MAR 22 2012/
UPDATE...FOR 00Z AVIATION DISCUSSION.
AVIATION...00Z AVIATION DISCUSSION.
UNCERTAINTIES...ACTUAL UPPER LEVEL LOW MOVEMENT/INFLUENCES AND SHWR/TSTM
DEVELOPMENT. SEVERAL ADMS POSSIBLE THRU 23/24Z. SOME GENERAL
UNCERTAINTY WITH ACTUAL CLOUD COVERAGE TRENDS...ALONG WITH MVFR
FOG DEVELOPMENT 23/06Z-23/12Z CKV/BNA. THUS...DIMINISH LIGHT SHWRS
AND ERODE CEILINGS BY 23/03Z CKV/BNA...WITH REDEVELOPING
SHWRS/TSTMS PER DIURNAL INFLUENCES AND APPROACHING UPPER LEVEL LOW
BY 23/24Z...WITH VFR CEILINGS. PER BETTER OVERALL MOISTURE...CSV
MVFR CEILINGS WITH LIGHT SHWRS TRANISTIONING TO TSTMS FROM 23/14Z-23/24Z.
PREV DISCUSSION.../ISSUED 632 PM CDT THU MAR 22 2012/
UPDATE...
SFC BOUNDARY ACROSS WESTERN MIDDLE TN CONTINUES TO DECREASE IN
STRENGTH IN TERMS OF THE FORCING ASSOCIATED WITH IT. ACTIVITY
ACROSS OUR EASTERN ZONES IS IN RESPONSE TO AN UPPER IMPULSE WITHIN
THE SOUTHERLY FLOW ALOFT. REDEVELOPMENT ACROSS WESTERN ZONES IS
STILL EXPECTED AS ADDITIONAL UPPER LEVEL ENERGY IS EXPECTED TO LIFT
NORTHWARD OVERNIGHT. LATEST NAM12 AND RUC SOLUTIONS ARE IN FAVOR OF
REDEVELOPMENT. HOWEVER...ADDITIONAL QPF AMOUNTS ARE NOT
SIGNIFICANT AND LOOK TO BE ONLY AROUND ONE QUARTER INCH OR SO.
FOR TONIGHT...I WILL BE LEANING TOWARD LOWERING THE POPS AS THE
FUTURE CONVECTION IS DEPENDENT UPON REDEVELOPMENT AS OPPOSED TO
MIGRATION.
OTW...LOW TEMPS LOOK TO BE IN GOOD SHAPE. THE LOWER DEW POINTS ARE
WAY BACK TOWARD FAR WESTERN TN. STILL THOUGH...FOR LOW TEMPS WE SHOULD
SEE UPPER 50S WESTERN AREAS BY SUNRISE WITH NEAR 60 ELSEWHERE. A
GENERALLY LIGHT S/SE WIND FLOW SHOULD CONTINUE.
UPDATED GIRDS/ZONES OUT SHORTLY.
PREV DISCUSSION... /ISSUED 339 PM CDT THU MAR 22 2012/
SHORT TERM...BAND OF SHOWERS AND ISOLATED THUNDERSTORMS CONTINUES
TO MOVE SLOWLY EASTWARD ACROSS THE MID STATE THIS AFTERNOON. BY
MID-AFTERNOON, THE BAND WAS CENTERED NEAR THE I-65 CORRIDOR.
AFTERNOON TEMPERATURES WERE MAINLY IN THE 70S WHERE RAIN HAD NOT YET
ARRIVED, BUT WERE IN THE UPPER 50S TO UPPER 60S IN THE RAIN-COOLED
AIR.
MODEL SOLUTIONS ARE STILL QUITE SIMILAR WITH THEIR HANDLING OF
SLOW-MOVING CLOSED UPPER LOW OVER THE NEXT FEW DAYS. THE MAIN
FORECAST DIFFICULTY WILL BE THE EXACT LOCATION OF THE DRY SLOT
ON FRIDAY AND THE RESULTING SHOWER/THUNDERSTORM PATTERN TO THE EAST.
RIGHT NOW IT LOOKS LIKE BAND OF PRECIP WILL CONTINUE SLOGGING
EASTWARD OVERNIGHT, BUT WILL PROBABLY SLOW SOMEWHAT AS IT PUSHES
TOWARD THE PLATEAU LATER TONIGHT.
DEEPEST MOISTURE SHOULD BE OVER EASTERN MIDDLE TENNESSEE FRIDAY,
WHERE DAYTIME INSTABILITY WILL BE GREATEST, ALONG WITH AT LEAST A
SLIGHT CHANCE FOR SEVERE THUNDERSTORMS (ATTENDED BY HAIL AND DAMAGING
STRAIGHT LINE WINDS). MEANWHILE, EXPECT WESTERN AREAS TO DRY OUT
DURING THE DAY.
AS CLOSED UPPER LOW PUSHES TO THE OHIO RIVER ON FRIDAY NIGHT, IT
SHOULD BE ACCOMPANIED BY A CIRCULAR AREA OF CLOUDS SIMILAR TO WHAT
WE`VE OBSERVED OVER THE PLAINS STATES TODAY. AS A RESULT EXPECT CLOUDS,
ALONG WITH A CHANCE OF SHOWERS AND THUNDERSTORMS, TO BE PRESENT
IN A RELATIVELY BROAD SWATH TO THE SOUTH AND EAST OF THE LOW PRESSURE
CENTER.
ON SATURDAY, AS COLD CORE LOW DROPS EAST-SOUTHEASTWARD ACROSS THE
TENNESSEE VALLEY, WE WILL SEE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS IN MIDDLE TENNESSEE. WITH COLDER AIR ALOFT, WOULD
NOT BE SURPRISED TO SEE SOME "HAILERS" ON SATURDAY.
SHOWERS FINALLY PULL EAST OF OUR AREA BY SUNDAY, AND GIVE WAY TO
A SPELL OF DRY WEATHER SUNDAY THROUGH TUESDAY. A RIDGE OF HIGH
PRESSURE BUILDS IN FROM THE WEST, ACCOMPANIED BY A WARMING TREND.
FOLLOWING WEEKEND HIGH TEMPERATURES IN THE UPPER 60S TO LOWER 70S
AT NASHVILLE, HIGHS WILL LIKELY PUSH BACK TO NEAR 80 DEGREES BY
TUESDAY.
LONG TERM...A SHORTWAVE WILL PUSH IN AND DAMPEN OUR FRIENDLY RIDGE
BY THE MIDDLE-TO-LATTER PART OF NEXT WEEK, BRINGING ALONG ANOTHER
CHANCE FOR SHOWERS AND THUNDERSTORMS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
651 PM CDT THU MAR 22 2012
.UPDATE...FOR 00Z AVIATION DISCUSSION.
&&
.AVIATION...00Z AVIATION DISCUSSION.
UNCERTAINTIES...ACTUAL UPPER LEVEL LOW MOVEMENT/INFLUENCES AND SHWR/TSTM
DEVELOPMENT. SEVERAL ADMS POSSIBLE THRU 23/24Z. SOME GENERAL
UNCERTAINTY WITH ACTUAL CLOUD COVERAGE TRENDS...ALONG WITH MVFR
FOG DEVELOPMENT 23/06Z-23/12Z CKV/BNA. THUS...DIMINISH LIGHT SHWRS
AND ERODE CEILINGS BY 23/03Z CKV/BNA...WITH REDEVELOPING
SHWRS/TSTMS PER DIURNAL INFLUENCES AND APPROACHING UPPER LEVEL LOW
BY 23/24Z...WITH VFR CEILINGS. PER BETTER OVERALL MOISTURE...CSV
MVFR CEILINGS WITH LIGHT SHWRS TRANISTIONING TO TSTMS FROM 23/14Z-23/24Z.
&&
.PREV DISCUSSION.../ISSUED 632 PM CDT THU MAR 22 2012/
UPDATE...
SFC BOUNDARY ACROSS WESTERN MIDDLE TN CONTINUES TO DECREASE IN
STRENGTH IN TERMS OF THE FORCING ASSOCIATED WITH IT. ACTIVITY
ACROSS OUR EASTERN ZONES IS IN RESPONSE TO AN UPPER IMPULSE WITHIN
THE SOUTHERLY FLOW ALOFT. REDEVELOPMENT ACROSS WESTERN ZONES IS
STILL EXPECTED AS ADDITIONAL UPPER LEVEL ENERGY IS EXPECTED TO LIFT
NORTHWARD OVERNIGHT. LATEST NAM12 AND RUC SOLUTIONS ARE IN FAVOR OF
REDEVELOPMENT. HOWEVER...ADDITIONAL QPF AMOUNTS ARE NOT
SIGNIFICANT AND LOOK TO BE ONLY AROUND ONE QUARTER INCH OR SO.
FOR TONIGHT...I WILL BE LEANING TOWARD LOWERING THE POPS AS THE
FUTURE CONVECTION IS DEPENDENT UPON REDEVELOPMENT AS OPPOSED TO
MIGRATION.
OTW...LOW TEMPS LOOK TO BE IN GOOD SHAPE. THE LOWER DEW POINTS ARE
WAY BACK TOWARD FAR WESTERN TN. STILL THOUGH...FOR LOW TEMPS WE SHOULD
SEE UPPER 50S WESTERN AREAS BY SUNRISE WITH NEAR 60 ELSEWHERE. A
GENERALLY LIGHT S/SE WIND FLOW SHOULD CONTINUE.
UPDATED GIRDS/ZONES OUT SHORTLY.
PREV DISCUSSION... /ISSUED 339 PM CDT THU MAR 22 2012/
SHORT TERM...BAND OF SHOWERS AND ISOLATED THUNDERSTORMS CONTINUES
TO MOVE SLOWLY EASTWARD ACROSS THE MID STATE THIS AFTERNOON. BY
MID-AFTERNOON, THE BAND WAS CENTERED NEAR THE I-65 CORRIDOR.
AFTERNOON TEMPERATURES WERE MAINLY IN THE 70S WHERE RAIN HAD NOT YET
ARRIVED, BUT WERE IN THE UPPER 50S TO UPPER 60S IN THE RAIN-COOLED
AIR.
MODEL SOLUTIONS ARE STILL QUITE SIMILAR WITH THEIR HANDLING OF
SLOW-MOVING CLOSED UPPER LOW OVER THE NEXT FEW DAYS. THE MAIN
FORECAST DIFFICULTY WILL BE THE EXACT LOCATION OF THE DRY SLOT
ON FRIDAY AND THE RESULTING SHOWER/THUNDERSTORM PATTERN TO THE EAST.
RIGHT NOW IT LOOKS LIKE BAND OF PRECIP WILL CONTINUE SLOGGING
EASTWARD OVERNIGHT, BUT WILL PROBABLY SLOW SOMEWHAT AS IT PUSHES
TOWARD THE PLATEAU LATER TONIGHT.
DEEPEST MOISTURE SHOULD BE OVER EASTERN MIDDLE TENNESSEE FRIDAY,
WHERE DAYTIME INSTABILITY WILL BE GREATEST, ALONG WITH AT LEAST A
SLIGHT CHANCE FOR SEVERE THUNDERSTORMS (ATTENDED BY HAIL AND DAMAGING
STRAIGHT LINE WINDS). MEANWHILE, EXPECT WESTERN AREAS TO DRY OUT
DURING THE DAY.
AS CLOSED UPPER LOW PUSHES TO THE OHIO RIVER ON FRIDAY NIGHT, IT
SHOULD BE ACCOMPANIED BY A CIRCULAR AREA OF CLOUDS SIMILAR TO WHAT
WE`VE OBSERVED OVER THE PLAINS STATES TODAY. AS A RESULT EXPECT CLOUDS,
ALONG WITH A CHANCE OF SHOWERS AND THUNDERSTORMS, TO BE PRESENT
IN A RELATIVELY BROAD SWATH TO THE SOUTH AND EAST OF THE LOW PRESSURE
CENTER.
ON SATURDAY, AS COLD CORE LOW DROPS EAST-SOUTHEASTWARD ACROSS THE
TENNESSEE VALLEY, WE WILL SEE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS IN MIDDLE TENNESSEE. WITH COLDER AIR ALOFT, WOULD
NOT BE SURPRISED TO SEE SOME "HAILERS" ON SATURDAY.
SHOWERS FINALLY PULL EAST OF OUR AREA BY SUNDAY, AND GIVE WAY TO
A SPELL OF DRY WEATHER SUNDAY THROUGH TUESDAY. A RIDGE OF HIGH
PRESSURE BUILDS IN FROM THE WEST, ACCOMPANIED BY A WARMING TREND.
FOLLOWING WEEKEND HIGH TEMPERATURES IN THE UPPER 60S TO LOWER 70S
AT NASHVILLE, HIGHS WILL LIKELY PUSH BACK TO NEAR 80 DEGREES BY
TUESDAY.
LONG TERM...A SHORTWAVE WILL PUSH IN AND DAMPEN OUR FRIENDLY RIDGE
BY THE MIDDLE-TO-LATTER PART OF NEXT WEEK, BRINGING ALONG ANOTHER
CHANCE FOR SHOWERS AND THUNDERSTORMS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
632 PM CDT THU MAR 22 2012
.UPDATE...
SFC BOUNDARY ACROSS WESTERN MIDDLE TN CONTINUES TO DECREASE IN
STRENGTH IN TERMS OF THE FORCING ASSOCIATED WITH IT. ACTIVITY
ACROSS OUR EASTERN ZONES IS IN RESPONSE TO AN UPPER IMPULSE WITHIN
THE SOUTHERLY FLOW ALOFT. REDEVELOPMENT ACROSS WESTERN ZONES IS
STILL EXPECTED AS ADDITIONAL UPPER LEVEL ENERGY IS EXPECTED TO LIFT
NORTHWARD OVERNIGHT. LATEST NAM12 AND RUC SOLUTIONS ARE IN FAVOR OF
REDEVELOPMENT. HOWEVER...ADDITIONAL QPF AMOUNTS ARE NOT
SIGNIFICANT AND LOOK TO BE ONLY AROUND ONE QUARTER INCH OR SO.
FOR TONIGHT...I WILL BE LEANING TOWARD LOWERING THE POPS AS THE
FUTURE CONVECTION IS DEPENDENT UPON REDEVELOPMENT AS OPPOSED TO
MIGRATION.
OTW...LOW TEMPS LOOK TO BE IN GOOD SHAPE. THE LOWER DEW POINTS ARE
WAY BACK TOWARD FAR WESTERN TN. STILL THOUGH...FOR LOW TEMPS WE SHOULD
SEE UPPER 50S WESTERN AREAS BY SUNRISE WITH NEAR 60 ELSEWHERE. A
GENERALLY LIGHT S/SE WIND FLOW SHOULD CONTINUE.
UPDATED GIRDS/ZONES OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 339 PM CDT THU MAR 22 2012/
SHORT TERM...BAND OF SHOWERS AND ISOLATED THUNDERSTORMS CONTINUES
TO MOVE SLOWLY EASTWARD ACROSS THE MID STATE THIS AFTERNOON. BY
MID-AFTERNOON, THE BAND WAS CENTERED NEAR THE I-65 CORRIDOR.
AFTERNOON TEMPERATURES WERE MAINLY IN THE 70S WHERE RAIN HAD NOT YET
ARRIVED, BUT WERE IN THE UPPER 50S TO UPPER 60S IN THE RAIN-COOLED
AIR.
MODEL SOLUTIONS ARE STILL QUITE SIMILAR WITH THEIR HANDLING OF
SLOW-MOVING CLOSED UPPER LOW OVER THE NEXT FEW DAYS. THE MAIN
FORECAST DIFFICULTY WILL BE THE EXACT LOCATION OF THE DRY SLOT
ON FRIDAY AND THE RESULTING SHOWER/THUNDERSTORM PATTERN TO THE EAST.
RIGHT NOW IT LOOKS LIKE BAND OF PRECIP WILL CONTINUE SLOGGING
EASTWARD OVERNIGHT, BUT WILL PROBABLY SLOW SOMEWHAT AS IT PUSHES
TOWARD THE PLATEAU LATER TONIGHT.
DEEPEST MOISTURE SHOULD BE OVER EASTERN MIDDLE TENNESSEE FRIDAY,
WHERE DAYTIME INSTABILITY WILL BE GREATEST, ALONG WITH AT LEAST A
SLIGHT CHANCE FOR SEVERE THUNDERSTORMS (ATTENDED BY HAIL AND DAMAGING
STRAIGHT LINE WINDS). MEANWHILE, EXPECT WESTERN AREAS TO DRY OUT
DURING THE DAY.
AS CLOSED UPPER LOW PUSHES TO THE OHIO RIVER ON FRIDAY NIGHT, IT
SHOULD BE ACCOMPANIED BY A CIRCULAR AREA OF CLOUDS SIMILAR TO WHAT
WE`VE OBSERVED OVER THE PLAINS STATES TODAY. AS A RESULT EXPECT CLOUDS,
ALONG WITH A CHANCE OF SHOWERS AND THUNDERSTORMS, TO BE PRESENT
IN A RELATIVELY BROAD SWATH TO THE SOUTH AND EAST OF THE LOW PRESSURE
CENTER.
ON SATURDAY, AS COLD CORE LOW DROPS EAST-SOUTHEASTWARD ACROSS THE
TENNESSEE VALLEY, WE WILL SEE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS IN MIDDLE TENNESSEE. WITH COLDER AIR ALOFT, WOULD
NOT BE SURPRISED TO SEE SOME "HAILERS" ON SATURDAY.
SHOWERS FINALLY PULL EAST OF OUR AREA BY SUNDAY, AND GIVE WAY TO
A SPELL OF DRY WEATHER SUNDAY THROUGH TUESDAY. A RIDGE OF HIGH
PRESSURE BUILDS IN FROM THE WEST, ACCOMPANIED BY A WARMING TREND.
FOLLOWING WEEKEND HIGH TEMPERATURES IN THE UPPER 60S TO LOWER 70S
AT NASHVILLE, HIGHS WILL LIKELY PUSH BACK TO NEAR 80 DEGREES BY
TUESDAY.
LONG TERM...A SHORTWAVE WILL PUSH IN AND DAMPEN OUR FRIENDLY RIDGE
BY THE MIDDLE-TO-LATTER PART OF NEXT WEEK, BRINGING ALONG ANOTHER
CHANCE FOR SHOWERS AND THUNDERSTORMS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
624 PM CDT THU MAR 22 2012
.SHORT TERM...TONIGHT THROUGH SUNDAY
321 PM CDT THU MAR 22 2012
MAIN FORECAST CONCERNS ARE ON RAIN SHOWER/ISOLATED THUNDERSTORM CHANCES
AND TEMPERATURES TONIGHT THROUGH FRIDAY.
CURRENT WATER VAPOR IMAGERY SHOWED A CLOSED UPPER LOW CENTERED OVER
NORTH CENTRAL OKLAHOMA. GULF OF MEXICO MOISTURE CONTINUED TO
STREAM NORTH THROUGH THE MIDDLE MISSISSIPPI RIVER VALLEY INTO
SOUTHERN IOWA.
LOOK FOR SHOWERS AND ISOLATED THUNDERSTORMS TO PERSIST ACROSS MUCH
OF THE AREA THIS EVENING...THEN GRADUALLY MOVING INTO WESTERN
WISCONSIN AFTER MIDNIGHT. THE RAIN SHOWERS SHOULD TAPER OFF ACROSS
ACROSS PORTIONS OF SOUTHEAST MINNESOTA INTO NORTHEAST IOWA LATE IN
THE NIGHT. THE LOW IS EXPECTED TO MOVE FROM NORTH CENTRAL OKLAHOMA
INTO SOUTHEAST KANSAS THIS EVENING THEN PUSH INTO SOUTHERN
MISSOURI BY FRIDAY MORNING. WILL HAVE TO KEEP A CLOSE WATCH ON A
DRY SLOT MOVING NORTHEAST OUT OF SOUTHWEST IOWA/NORTHWEST
MISSOURI. IF THE DRY SLOT MOVES INTO THE REGION AND SKIES
CLEAR...DENSE FOG WOULD OCCUR ESPECIALLY WITH THE PRECONDITIONING
FROM THE RAIN SHOWERS LATE THIS AFTERNOON THROUGH THIS EVENING.
PLAN ON LOW TEMPERATURES TONIGHT RANGING FROM THE LOWER 50S ACROSS
NORTH CENTRAL WISCONSIN TO THE UPPER 40S ACROSS NORTH CENTRAL INTO
PORTIONS OF NORTHEAST IOWA.
850 MB MOISTURE IS EXPECTED TO WEAKEN FRIDAY MORNING...BUT WILL
CONTINUE TO FOCUS INTO CENTRAL WISCONSIN AND SOUTHEAST MINNESOTA.
WILL CONTINUE WITH LIKELY SHOWERS ALONG AND NORTH OF THE
INTERSTATE 94 CORRIDOR...WITH A CHANCE OF SHOWERS ACROSS THE REST
OF THE FORECAST AREA. CLOUDS WILL LINGER ACROSS THE FORECAST AREA
THROUGH THE DAY ON FRIDAY A MOISTURE CONTINUE TO WRAP NORTH AND
WEST AROUND THE UPPER LOW. CLOUDS COULD BREAK UP ENOUGH TO SEE
SOME SUN ACROSS PORTIONS OF NORTHEAST IOWA THROUGH FAR SOUTHERN
WISCONSIN. THIS WILL DEPEND ON IF THE DRY SLOT CAN WORK INTO THESE
AREAS. PLAN ON HIGH TEMPERATURES MAINLY IN THE 60S. THE NAM SHOWS
0-3 KM MUCAPE VALUES CLIMBING TO AROUND 1000 J/KG ACROSS NORTHEAST
IOWA INTO FAR SOUTHERN WISCONSIN. THIS IS IN RESPONSE TO MORE
SUNSHINE OCCURRING ACROSS THESE AREAS. FEEL THESE CAPE VALUES ARE
A BIT OVERDONE GIVEN THE EXPECTED CLOUD COVER ACROSS THE AREA SO
WILL MAINTAIN SHOWERS VERSUS ISOLATED THUNDERSTORM MENTION. THE
LOW WILL MOVE INTO THE OHIO RIVER VALLEY REGION FRIDAY NIGHT INTO
SATURDAY MORNING. SHOWER CHANCES WILL LINGER THROUGH FRIDAY NIGHT
AS MOISTURE CONTINUE TO ADVECT NORTHWEST AROUND THE UPPER LOW.
LOOK FOR LOW TEMPERATURES TO FALL INTO THE 50S. HIGH PRESSURE WILL
BUILD INTO THE REGION SATURDAY AFTERNOON WITH RAIN SHOWER CHANCES
SHIFTING EAST OF THE FORECAST AREA. AN UPPER LEVEL RIDGE IS
EXPECTED TO BUILD ACROSS THE UPPER MIDWEST SATURDAY NIGHT WITH
CLOUDS DECREASING FROM WEST TO EAST. PLAN ON HIGH TEMPERATURES ON
SATURDAY RANGING FROM THE MID 60S ACROSS NORTH CENTRAL WISCONSIN
TO AROUND 70 ACROSS NORTHEAST IOWA. LOW TEMPERATURES WILL FALL
INTO THE UPPER 40S TO LOWER 50S. WARM AN QUIET CONDITIONS ARE
EXPECTED ACROSS THE AREA ON SUNDAY WITH HIGH PRESSURE IN CONTROL.
HIGH TEMPERATURES WILL RANGE FROM THE LOWER 60S ACROSS NORTH
CENTRAL WISCONSIN TO THE LOWER 70S ACROSS NORTHEAST IOWA INTO FAR
SOUTHWEST WISCONSIN. COOL CANADIAN SURFACE HIGH PRESSURE WILL
SLIDE INTO THE REGION SUNDAY NIGHT INTO MONDAY BRINGING COOLER
TEMPERATURES TO THE AREA. LOW TEMPERATURES SUNDAY NIGHT WILL RANGE
FROM THE LOWER 40S ACROSS NORTH CENTRAL WISCONSIN TO AROUND 50
ACROSS NORTHEAST IOWA.
.LONG TERM...MONDAY THROUGH THURSDAY
321 PM CDT THU MAR 22 2012
22.12 MEDIUM RANGE MODELS IN BETTER AGREEMENT ON MONDAY SETTLING THE
COOL CANADIAN HIGH OVER THE REGION. THE GEM CONTINUES TO INDICATE
THE COOLEST TEMPERATURES...WITH HIGHS ONLY IN THE 40S. CHOSE TO
LEAN TOWARD A MODEL CONSENSUS BLEND WITH HIGHS RANGING FROM THE
LOWER 50S ACROSS NORTH CENTRAL WISCONSIN TO THE LOWER TO MIDDLE
60S ACROSS NORTHEAST IOWA. THE HIGH WILL SLIDE EAST OF THE AREA
MONDAY NIGHT INTO TUESDAY AS A WARM FRONT PUSHES INTO THE UPPER
MISSISSIPPI RIVER VALLEY FROM THE CENTRAL/NORTHERN PLAINS. SHOWERS
AND THUNDERSTORMS ARE EXPECTED TO SPREAD ACROSS THE AREA MONDAY
NIGHT INTO TUESDAY MORNING ALONG THE WARM FRONT. FORECAST MODELS
CONTINUE TO SHOW A COLD FRONT SWEEPING ACROSS THE FORECAST AREA
TUESDAY AFTERNOON INTO TUESDAY EVENING. SHEAR PROFILES STILL
APPEAR FAVORABLE FOR SEVERE THUNDERSTORMS. HOWEVER...THE LATEST
GUIDANCE HAS BACKED OFF ON CAPE VALUES. THE GFS IS SHOWING 0-3 KM
MUCAPE VALUES OF 300 TO 800 J/KG. 0-6 KM BULK SHEAR LOOKS TO BE
AROUND 40 TO 45 KTS...WITH 0-1 SHEAR OF 25 TO 35 KTS. WILL HAVE TO
CONTINUE TO CLOSELY WATCH THE NEXT FEW MODEL RUNS. WEDNESDAY
SHOULD BE A BREEZY AND DRY DAY IN THE WAKE OF THE COLD FRONT.
MODELS INDICATING SOME LARGE DIFFERENCES ON THURSDAY. THE ECMWF
INDICATES ACTIVE SOUTHWEST FLOW ACROSS THE AREA WHILE THE GFS
SHOWS SURFACE HIGH PRESSURE AND AN UPPER RIDGE ACROSS THE REGION.
WILL LEAN TOWARDS THE ECMWF ON THURSDAY..WITH CHANCES FOR SHOWERS
AND THUNDERSTORMS ACROSS THE FORECAST AREA. PLAN ON HIGH
TEMPERATURES TUESDAY THROUGH THURSDAY RANGING FROM THE MIDDLE TO
UPPER 50S ACROSS NORTH CENTRAL WISCONSIN TO MID TO LOWER 60S
ACROSS NORTHEAST IOWA INTO FAR SOUTHWEST WISCONSIN.
&&
.AVIATION...TONIGHT AND FRIDAY
624 PM CDT THU MAR 22 2012
LOCAL AND REGIONAL RADARS SUGGEST THE MAIN BAND OF SHOWERS HAS
ALREADY LIFTED NORTH THROUGH BOTH TAF SITES. THERE ARE STILL SOME
ADDITIONAL SHOWERS OR SPRINKLES ACROSS NORTHEAST IOWA THAT MAY
ROTATE NORTH INTO THE AREA LATER THIS EVENING. HOWEVER...THE
22.19Z RUN OF THE HRRR SHOWS THESE LIGHT SHOWERS/SPRINKLES
DISSIPATING THROUGH THE EVENING WITH A BETTER CHANCE OF STAYING
DRY THAN SEEING ADDITIONAL LIGHT RAIN. HOWEVER...THE 22.18Z NAM
SUGGESTS THESE SHOWERS WILL HOLD TOGETHER AND GET INTO BOTH TAF
SITES. WITH THEM STILL ONGOING...HARD TO IGNORE THEM SO WILL CARRY
SOME NON-VISIBILITY REDUCING SHOWERS FOR THE MID AND LATE EVENING
HOURS BEFORE DROPPING BACK TO JUST VICINITY SHOWERS FOR THE
REMAINDER OF THE NIGHT INTO FRIDAY AS THE MAIN AREA OF MOISTURE
TRANSPORT SHIFTS NORTH OF THE TAF SITES. WILL CONTINUE THE TREND
OF DROPPING CEILINGS TO MVFR FOR BOTH SITES ON THE BACK SIDE OF
THE NEXT BAND OF SHOWERS AS CURRENT OBSERVATIONS DO SHOW THESE
CONDITIONS FROM SOUTHEAST INTO NORTH CENTRAL IOWA. NAM BUFKIT
SOUNDINGS WOULD SUGGESTS THE MVFR CONDITIONS WOULD THEN CONTINUE
THROUGH ALL OF FRIDAY BUT CURRENT OBSERVATIONS SHOW VFR CONDITIONS
OVER WESTERN IOWA AND WILL SHOW AN IMPROVEMENT TO VFR OCCURRING
LATE FRIDAY AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
321 PM CDT THU MAR 22 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1241 PM CDT WED MAR 21 2012
.SHORT TERM...THROUGH FRIDAY
345 AM CDT WED MAR 21 2012
FOCUS IS ON RAIN CHANCES THROUGH THE PERIOD ALONG WITH UNSEASONABLY
WARM TEMPERATURES CONTINUING.
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A LARGE CLOSED LOW OVER TX
WITH HIGHLY AMPLIFIED RIDGE OVER THE EASTERN CONUS. DEEP SOUTHERLY
WARM/MOIST FETCH CONTINUES AHEAD OF THE LOW INTO THE UPPER
MISSISSIPPI RIVER VALLEY REGION. AS A RESULT...NATIONAL RADAR MOSAIC
SHOWS LARGE CONVEYOR BELT OF SHRA EXTENDING FROM THE LA GULF COAST
AREA NORTHWARD INTO SOUTHERN IA...THEN TAPERING OFF GOING INTO
NORTHEAST IA/SOUTHEAST MN. MEANWHILE...LOCAL RADAR MOSAIC ALSO
SHOWING FRONTOGENETIC FORCED SHRA ACTIVITY OCCURRING ACROSS THE
ARROWHEAD OF MN/NORTHWEST WI...DOWN THROUGH SOUTH CENTRAL MN.
OTHERWISE...EAST OF THE MISSISSIPPI RIVER IN OUR FORECAST AREA...DRY
AND WARM CONDITIONS PREVAILED WITH TEMPERATURES AT 2 AM STILL IN THE
60S.
21.00Z NCEP MODEL SUITE/GEM/ECMWF/20.21Z SREF ALL IN GOOD AGREEMENT
WITH HANDLING OF THE CLOSED LOW COMING OUT OF TX AND ITS AFFECT ON
OUR AREA.
FOR TODAY...WILL CONTINUE TO SEE MOISTURE FEED AHEAD OF THE UPPER
LOW INTO OUR REGION NAM DEPICTING SFC-700MB FRONTOGENESIS REMAINING
NORTHWEST OF OUR AREA FOR FOCUS OF HIGHEST RAIN CHANCES. WITH THIS
IN MIND AND RIDGING OVER THE GREAT LAKES PROVIDING DRYING IN THE
LOWER LEVELS OF THE ATMOSPHERE EAST OF THE MISSISSIPPI RIVER...HAVE
TRIMMED BEST RAIN CHANCES FARTHER NORTHWEST. THIS KEEPS EAST OF A
LINE FROM BLACK RIVER FALLS THROUGH LA CROSSE AND OELWEIN IA DRY FOR
TODAY. THUNDER THREAT WITH THE SHRA ACROSS THE NORTHWEST PARTS OF
THE FORECAST AREA NOT THAT GREAT TODAY AS CAPE IS MINIMAL. DID KEEP
SOME MENTION OF ISOLATED THUNDER IN WITH DECENT FRONTOGENETIC
FORCING. OTHERWISE...LOOKS LIKE ANOTHER UNSEASONABLY WARM DAY TODAY
WITH AREAS VOID OF RAIN TODAY SEEING TEMPERATURES TOPPING OFF IN THE
UPPER 70S.
TONIGHT WILL SEE BEST SHRA CHANCES STAYING ACROSS NORTHWEST HALF OF
THE FORECAST AREA //ROUGHLY NORTHWEST OF A LINE FROM BLACK RIVER
FALLS WI-LA CROSSE WI-OELWEIN IA// WITH LINGERING AREA OF 850-700MB
FRONTOGENESIS.
FOR THURSDAY THROUGH FRIDAY...WILL SEE THAT CLOSED LOW OVER
THE SOUTHERN PLAINS LIFT NORTHEAST INTO MO. THIS SWINGS A BAND OF
MAINLY SHRA NORTHEASTWARD INTO THE AREA. DID INCLUDE ISOLATED
THUNDER MENTION DURING THE DAY THURSDAY AS THE NAM DEPICTS 0-1KM ML
CAPE AROUND 800J/KG DURING THE DAY THURSDAY. FRIDAY LOOKS A BIT MORE
DOUBTFUL FOR THUNDER WITH VERY LIMITED CAPE...BUT OPTED TO KEEP IT
IN FOR NOW. OTHERWISE...LOOKS LIKE RAIN TOTALS POTENTIALLY RUNNING
FROM 1/4 TO 3/4 OF AN INCH.
MAINTAINED SOME SLIGHT CHANCE OF SHRA FRIDAY NIGHT AS THE CLOSED LOW
LIFTS INTO IL AND CYCLONIC FLOW AFFECTS THE AREA.
TEMPERATURE-WISE THURSDAY THROUGH FRIDAY...TEMPERATURES SHOULD TOP
OFF IN THE MID 60S TO LOWER 70S ON THURSDAY BEFORE TH RAIN SETS
IN...AND THEN COOL INTO THE LOWER AND MIDDLE 60S ON FRIDAY WITH
LIKELIHOOD OF RAIN AND CLOUD COVER.
.LONG TERM...SATURDAY THROUGH TUESDAY
345 AM CDT WED MAR 21 2012
21.00Z GFS/ECMWF SHOWS THE CLOSED LOW MOVES ACROSS IL ON SATURDAY
WITH COOLER/CYCLONIC FLOW ALOFT AFFECTING OUR AREA ALONG WITH A
SLIGHT CHANCE OF -SHRA. AS THE CLOSED LOW SHIFTS EAST OF TH REGION
ON SUNDAY...UPPER LEVEL RIDGING BUILDS INTO THE AREA FOR DRY AND
WARMER CONDITIONS. LOOK FOR TEMPERATURES TO REBOUND BACK INTO THE
60S TO LOWER 70S. MONDAY COULD SEE THE POTENTIAL FOR A RATHER STEEP
NORTHEAST TO SOUTHWEST TEMPERATURE GRADIENT ACROSS THE AREA. THIS IS
DUE TO SURFACE HIGH PRESSURE BUILDING SOUTH OUT OF ONTARIO INTO THE
GREAT LAKES REGION. COOLER NORTHEAST FLOW HAS THE POTENTIAL FOR
HOLDING TEMPERATURES AROUND 60 OVER NORTH CENTRAL WI...TO NEAR 80
DEGREES ACROSS PARTS OF NORTHEAST IOWA. IN ADDITION...THERE IS THE
POTENTIAL FOR SOME SHOWERS ACROSS PORTIONS OF THE AREA IN ISENTROPIC
LIFT AHEAD OF LOW PRESSURE OVER THE NORTHERN PLAINS. SHRA/TS CHANCE
ENTER THE PICTURE MONDAY NIGHT/TUESDAY AS THE LOW OVER THE NORTHERN
PLAINS PUSHES TOWARD THE AREA.
&&
.AVIATION...THROUGH 18Z THURSDAY
1240 PM CDT WED MAR 21 2012
A RIDGE OF HIGH PRESSURE WILL BUILD ACROSS THE AREA THIS AFTERNOON AND
EVENING. AS THIS OCCURS...THE MVFR CEILINGS WILL PUSH OFF TO THE WEST
OF THE FORECAST AREA. THIS WILL LEAVE BOTH TAF SITES VFR THROUGH TONIGHT.
AS SOME FRONTOGENESIS TO THE NORTH OF AN UPPER LEVEL LOW PRESSURE
MOVES INTO THE AREA ON THURSDAY MORNING...CEILINGS WILL GRADUALLY
BECOME MVFR AND SHOWERS WILL SPREAD NORTHWARD INTO THE AREA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
345 AM CDT WED MAR 21 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...BOYNE
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1222 PM CDT WED MAR 21 2012
.UPDATE...
INHERITED FCST PACKAGE FOR TODAY PERIOD APPEARS ON TRACK...WITH FEW
CHANGES MADE. MAX TEMPS WERE BUMPED UP A FEW DEGREES GIVEN HOW DEEP
MIXING WILL BE. RUC MODEL GUIDANCE HAS MIXING INLAND UP TO 825 HPA
AT SOME SPOTS. THIS...UPSTREAM CONDITIONS...AND LACK OF CLOUD COVER
SHOULD ALLOW TEMPS TO EXCEED...IF NOT REACH...YESTERDAY/S
HIGHS...WITH HIGHS BACK INTO THE LOW 80S AND HIGH 70S EXCEPT NEAR
THE SHORELINE. GIVEN LATEST VIS LOOP...CLOUDS ARE NOT ANTICIPATED
TO GREATLY AFFECT TEMP FCST. CLOUD SHIELD SHOULD STAY OFF TO THE
WEST OF CWA THIS AFTERNOON...THOUGH FEW-SCT CIRRUS NOT OUT OF THE
QUESTION.
&&
.AVIATION/18Z TAFS/...
FOR THE REMAINDER OF TODAY EXPECT SIMILAR CONDITIONS TO YESTERDAY.
LAKE BREEZE BOUNDARY HAS NOT YET PUSHED THROUGH MKE/ENW AND IF
SOUTHERLY WINDS CONTINUE THE LAKE BREEZE WILL BE HELD OFF UNTIL
LATE AFTERNOON...PERHAPS AROUND 2200Z. SOME UNCERTAINTY AS TO
EXACT TIMING SO WILL HAVE TO WATCH FOR AMENDMENTS. VFR CONDITIONS
EXPECTED UNTIL JUST BEFORE SUNRISE THURSDAY WHEN LIGHT FOG MAY
FORM. CHANCE FOR SHOWERS AFTER THAT TIME AS WELL...BUT ANY SHOWERS
WILL HAVE TO OVERCOME DRY LAYER NEAR THE SURFACE...SO NOT A LOT OF
CONFIDENCE.
&&
.PREV DISCUSSION... /ISSUED 336 AM CDT WED MAR 21 2012/
SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH.
PERSISTENCE PROBABLY THE BEST APPROACH FOR TODAY. LOW LEVEL WINDS
AND THERMAL STRUCTURE LOOK VERY SIMILAR TO YESTERDAY. MAIN
DIFFERENCE WOULD BE MORE HIGH CLOUDS MOVING THROUGH THE AREA AS THE
WARM AND MOIST CONVEYOR BELT REMAINS JUST TO OUR WEST. THE FORECAST
AREA CONTINUES TO SIT UNDER THE RIDGE AXIS THAT HAS BEEN
STRENGTHENED BY THE DEEPENING OF THE UPPER LOW OVER THE SOUTHERN
PLAINS. MANY OF THE MODELS EJECT SOME SHORT WAVE ENERGY UP THROUGH
THE MISSISSIPPI RIVER VALLEY/FAR WRN WI TODAY AND TONIGHT. THIS IS
INTO THE RIDGE AXIS AND MOISTURE LOOKS QUITE LOW THROUGH THE COLUMN.
IN FACT...WE SHOULD SEE DEWPOINTS MIX OUT INTO THE LOWER 50S AGAIN
THIS AFTERNOON. PROBABLY NOT AS LOW AS YESTERDAY WITH SOME HIGHER
DEWPOINT AIR ADVECTING INTO THE AREA FROM THE SOUTH SOUTHEAST. WOULD
EXPECT THESE SHORT WAVES TO ONLY BRING SOME MID OR HIGH CLOUDS AT
TIMES AND ANY PRECIP SHOULD STAY WELL WEST OF THE AREA. STEEP LAPSE
RATES MIXING UP TO ABOUT 825MB WILL AGAIN RESULT IN GUSTY WINDS THIS
AFTERNOON.
TEMPS NEAR THE LAKE REMAIN A CHALLENGE. THE SOUTHERLY FLOW WILL MAKE
THE SHEBOYGAN AREA COOLER AGAIN GIVEN THE LAKE SHORE ORIENTATION UP
THERE. FARTHER TO THE SOUTH...ANY COOLING DUE TO THE LAKE WILL BE
LIMITED TO THOSE AREAS VERY CLOSE TO THE SHORE. IT COULD BE UPPER
40S AT THE BEACH AND 80 ABOUT 3 MILES INLAND.
THE QUIET WEATHER WILL CONTINUE INTO TONIGHT AND HAVE PULLED THE
PRECIP MENTION ACROSS THE FAR WEST.
THURSDAY AND THURSDAY NIGHT...FORECAST CONFIDENCE...MEDIUM.
THAT UPPER LOW MEANDERING ACROSS THE CENTRAL U.S. IS PROGGED TO BE
CENTERED OVER THE OKLAHOMA/KANSAS BORDER ON THURSDAY. PRECIP ON THE
NORTHERN WRAP-AROUND REGION OF THE UPPER LOW IS EXPECTED TO PUSH
INTO SOUTH CENTRAL WI ON THU. MODELS HAVE SLOWED THE TIMING OF THE
MAIN PRECIP GETTING INTO SOUTH CENTRAL WI...SO DELAYED LIKELIES IN
SW FORECAST AREA UNTIL THU AFTERNOON. WEAK SHORTWAVES ROTATING
AROUND THE UPPER LOW SHOULD SUPPORT NUMEROUS RAIN SHOWERS OVER THE
FORECAST AREA...ESPECIALLY THU NIGHT.
WEAK CAPE AND SHEAR SHOULD LIMIT THE THUNDERSTORM POTENTIAL WITH
THESE SHOWERS ASSOCIATED WITH THE UPPER LOW...BUT CANNOT RULE THEM
OUT COMPLETELY GIVEN THE COLDER 500MB TEMPS LENDING TO STEEPER MID
LEVEL LAPSE RATES...SO KEPT MENTION OF ISOLATED THUNDER.
BIG UNCERTAINTY FOR MAX TEMPS. WITH CLOUDS...PRECIP AND SOUTHEAST
FLOW ACROSS THE AREA...MAX TEMPS WILL BE LOWER THAN THE PREVIOUS
COUPLE OF DAYS. HOWEVER...EXPECTING A DELAY IN THE PRECIP UNTIL THE
AFTERNOON AND POSSIBLY LATER...SO RAISED THE TEMPS INTO THE MID 70S
IN PARTS OF SOUTHEAST WI.
LONG TERM...
FRIDAY THROUGH SATURDAY...FORECAST CONFIDENCE...MEDIUM.
THE UPPER LOW WILL TAKE ITS TIME DRIFTING EASTWARD...SO THERE WILL
BE RAIN SHOWER CHANCES ACROSS SOUTHERN WI DURING THIS PERIOD. KEPT
MENTION OF ISOLATED THUNDER FOR FRIDAY WITH WEAK INSTABILITY PRESENT.
TEMPERATURES WILL BE COOLER OVER THE WEEKEND WITH CLOUDS AND PRECIP
IN THE AREA. HIGHS EXPECTED IN THE MID TO UPPER 60S. THIS COULD BE
LOW DEPENDING ON HOW MUCH SUN CAN BREAK THROUGH.
SATURDAY NIGHT THROUGH SUNDAY...FORECAST CONFIDENCE...MEDIUM.
UPPER RIDGE WILL NOSE INTO THE CENTRAL U.S. TEMPERATURES WILL BE
COOLER THAN THIS PAST WEEK...WITH HIGHS IN THE 60S AND UPPER 50S
NEAR THE LAKESHORE...WHICH IS STILL WELL ABOVE NORMAL FOR THIS TIME
OF YEAR. TEMPERATURES SHOULD WARM INTO THE UPPER 60S OR BACK INTO
THE 70S TOWARD WESTERN WI WITH THE BUILDING RIDGE. EASTERLY FLOW OFF
LAKE MICHIGAN WILL KEEP THE LAKESHORE COOL AND A TIGHT TEMP GRADIENT
ACROSS THE FORECAST AREA.
DRY WEATHER EXPECTED DURING THIS PERIOD...WITH DECREASING CLOUDS AS
THE UPPER LOW DRIFTS EASTWARD.
MONDAY THROUGH TUESDAY...FORECAST CONFIDENCE...LOW.
ECMWF AND GFS BEGIN TO DIFFER IN THE EXTENDED. THE ECMWF KEEPS A
500MB LOW STATIONED OVER THE EAST COAST MON NIGHT WHILE THE GFS
MOVED IT OFF THE COAST. BOTH MODELS HAVE A RIDGE OVER THE CENTER OF
THE COUNTRY AND ANOTHER TROUGH DIGGING INTO THE WEST. THIS
DIFFERENCE SPELLS TWO POSSIBILITIES FOR MAX TEMPS...EITHER IN THE
UPPER 60S OR UPPER 70S/80S. TOOK A BLEND OF MODELS AND WENT WITH
LOWER 70S INLAND FROM THE LAKE FOR NOW. THERE COULD BE SOME WARM AIR
ADVECTION SHOWERS/THUNDERSTORMS DURING THIS PERIOD. A TRAILING FRONT
IS EXPECTED TO BRING ANOTHER CHANCE FOR TSTORMS TUE NIGHT/WED. THE
TIMING OF THIS FRONT IS SLOWING DOWN WITH THE LATEST MODEL RUNS.
AVIATION/12Z TAFS/...
VFR THROUGH THE PERIOD. WILL CARRY LOW LEVEL WIND SHEAR UNTIL WE
BEGIN TO MIX DEEPER INTO THE ATMOSPHERE BY ABOUT MID MORNING. LOOK
FOR GUSTY SOUTH WINDS AGAIN...POSSIBLY TURNING SOUTHEAST AT
KMKE/KENW DUE TO THE LAKE BREEZE.
MARINE...DESPITE THE SOMEWHAT STRONG AND GUSTY WINDS EXPECTED OVER
THE LAND...THE COOLER LAKE AIR WILL CREATE A STABILIZING INVERSION.
THIS WILL PREVENT THE WINDS FROM REACHING SMALL CRAFT ADVISORY LEVELS
OVER THE WATER.
FIRE WEATHER...ANOTHER DAY OF STRONG BOUNDARY LAYER MIXING IS
ANTICIPATED TODAY. HOWEVER PERSISTENT SOUTH TO SOUTHEAST
WINDS ARE EXPECTED TO USHER IN SLIGHTLY HIGHER DEWPTS FROM THE
CENTRAL GTLAKES AND NRN OH VALLEY FOR THIS. HENCE NOT EXPECTING AS
LOW RH...BUT MAY DROP AS LOW AS 30 TO 35 PERCENT. ENERGY RELEASE
COMPONENT FOR RAWS SITES EXPECTED TO REMAIN LESS THAN 40 TODAY SO
CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED TO BE APPROACHED...BUT
NOT REACHED AT THIS TIME.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...ET/WIMBERLEY
TODAY/TONIGHT AND AVIATION/MARINE...DAVIS
THURSDAY THROUGH TUESDAY...MRC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
623 AM CDT WED MAR 21 2012
.SHORT TERM...THROUGH FRIDAY
345 AM CDT WED MAR 21 2012
FOCUS IS ON RAIN CHANCES THROUGH THE PERIOD ALONG WITH UNSEASONABLY
WARM TEMPERATURES CONTINUING.
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A LARGE CLOSED LOW OVER TX
WITH HIGHLY AMPLIFIED RIDGE OVER THE EASTERN CONUS. DEEP SOUTHERLY
WARM/MOIST FETCH CONTINUES AHEAD OF THE LOW INTO THE UPPER
MISSISSIPPI RIVER VALLEY REGION. AS A RESULT...NATIONAL RADAR MOSAIC
SHOWS LARGE CONVEYOR BELT OF SHRA EXTENDING FROM THE LA GULF COAST
AREA NORTHWARD INTO SOUTHERN IA...THEN TAPERING OFF GOING INTO
NORTHEAST IA/SOUTHEAST MN. MEANWHILE...LOCAL RADAR MOSAIC ALSO
SHOWING FRONTOGENETIC FORCED SHRA ACTIVITY OCCURRING ACROSS THE
ARROWHEAD OF MN/NORTHWEST WI...DOWN THROUGH SOUTH CENTRAL MN.
OTHERWISE...EAST OF THE MISSISSIPPI RIVER IN OUR FORECAST AREA...DRY
AND WARM CONDITIONS PREVAILED WITH TEMPERATURES AT 2 AM STILL IN THE
60S.
21.00Z NCEP MODEL SUITE/GEM/ECMWF/20.21Z SREF ALL IN GOOD AGREEMENT
WITH HANDLING OF THE CLOSED LOW COMING OUT OF TX AND ITS AFFECT ON
OUR AREA.
FOR TODAY...WILL CONTINUE TO SEE MOISTURE FEED AHEAD OF THE UPPER
LOW INTO OUR REGION NAM DEPICTING SFC-700MB FRONTOGENESIS REMAINING
NORTHWEST OF OUR AREA FOR FOCUS OF HIGHEST RAIN CHANCES. WITH THIS
IN MIND AND RIDGING OVER THE GREAT LAKES PROVIDING DRYING IN THE
LOWER LEVELS OF THE ATMOSPHERE EAST OF THE MISSISSIPPI RIVER...HAVE
TRIMMED BEST RAIN CHANCES FARTHER NORTHWEST. THIS KEEPS EAST OF A
LINE FROM BLACK RIVER FALLS THROUGH LA CROSSE AND OELWEIN IA DRY FOR
TODAY. THUNDER THREAT WITH THE SHRA ACROSS THE NORTHWEST PARTS OF
THE FORECAST AREA NOT THAT GREAT TODAY AS CAPE IS MINIMAL. DID KEEP
SOME MENTION OF ISOLATED THUNDER IN WITH DECENT FRONTOGENETIC
FORCING. OTHERWISE...LOOKS LIKE ANOTHER UNSEASONABLY WARM DAY TODAY
WITH AREAS VOID OF RAIN TODAY SEEING TEMPERATURES TOPPING OFF IN THE
UPPER 70S.
TONIGHT WILL SEE BEST SHRA CHANCES STAYING ACROSS NORTHWEST HALF OF
THE FORECAST AREA //ROUGHLY NORTHWEST OF A LINE FROM BLACK RIVER
FALLS WI-LA CROSSE WI-OELWEIN IA// WITH LINGERING AREA OF 850-700MB
FRONTOGENESIS.
FOR THURSDAY THROUGH FRIDAY...WILL SEE THAT CLOSED LOW OVER
THE SOUTHERN PLAINS LIFT NORTHEAST INTO MO. THIS SWINGS A BAND OF
MAINLY SHRA NORTHEASTWARD INTO THE AREA. DID INCLUDE ISOLATED
THUNDER MENTION DURING THE DAY THURSDAY AS THE NAM DEPICTS 0-1KM ML
CAPE AROUND 800J/KG DURING THE DAY THURSDAY. FRIDAY LOOKS A BIT MORE
DOUBTFUL FOR THUNDER WITH VERY LIMITED CAPE...BUT OPTED TO KEEP IT
IN FOR NOW. OTHERWISE...LOOKS LIKE RAIN TOTALS POTENTIALLY RUNNING
FROM 1/4 TO 3/4 OF AN INCH.
MAINTAINED SOME SLIGHT CHANCE OF SHRA FRIDAY NIGHT AS THE CLOSED LOW
LIFTS INTO IL AND CYCLONIC FLOW AFFECTS THE AREA.
TEMPERATURE-WISE THURSDAY THROUGH FRIDAY...TEMPERATURES SHOULD TOP
OFF IN THE MID 60S TO LOWER 70S ON THURSDAY BEFORE TH RAIN SETS
IN...AND THEN COOL INTO THE LOWER AND MIDDLE 60S ON FRIDAY WITH
LIKELIHOOD OF RAIN AND CLOUD COVER.
.LONG TERM...SATURDAY THROUGH TUESDAY
345 AM CDT WED MAR 21 2012
21.00Z GFS/ECMWF SHOWS THE CLOSED LOW MOVES ACROSS IL ON SATURDAY
WITH COOLER/CYCLONIC FLOW ALOFT AFFECTING OUR AREA ALONG WITH A
SLIGHT CHANCE OF -SHRA. AS THE CLOSED LOW SHIFTS EAST OF TH REGION
ON SUNDAY...UPPER LEVEL RIDGING BUILDS INTO THE AREA FOR DRY AND
WARMER CONDITIONS. LOOK FOR TEMPERATURES TO REBOUND BACK INTO THE
60S TO LOWER 70S. MONDAY COULD SEE THE POTENTIAL FOR A RATHER STEEP
NORTHEAST TO SOUTHWEST TEMPERATURE GRADIENT ACROSS THE AREA. THIS IS
DUE TO SURFACE HIGH PRESSURE BUILDING SOUTH OUT OF ONTARIO INTO THE
GREAT LAKES REGION. COOLER NORTHEAST FLOW HAS THE POTENTIAL FOR
HOLDING TEMPERATURES AROUND 60 OVER NORTH CENTRAL WI...TO NEAR 80
DEGREES ACROSS PARTS OF NORTHEAST IOWA. IN ADDITION...THERE IS THE
POTENTIAL FOR SOME SHOWERS ACROSS PORTIONS OF THE AREA IN ISENTROPIC
LIFT AHEAD OF LOW PRESSURE OVER THE NORTHERN PLAINS. SHRA/TS CHANCE
ENTER THE PICTURE MONDAY NIGHT/TUESDAY AS THE LOW OVER THE NORTHERN
PLAINS PUSHES TOWARD THE AREA.
&&
.AVIATION...TODAY AND TONIGHT
623 AM CDT WED MAR 21 2012
LOW LEVEL SOUTH TO SOUTHEASTERLY FLOW BRINGING DRIER AIR IN FROM
HIGH PRESSURE OVER THE EASTERN U.S. WILL HELP TO MAINTAIN VFR
CONDITIONS THROUGH TONIGHT AT BOTH TAF SITES. HOWEVER...SOME
LIGHT SHOWER ACTIVITY IS EXPECTED THIS MORNING AT KRST...WHICH AS
OF 11Z HAS BEEN SPREADING NORTH THROUGH EASTERN IOWA. NOT
ANTICIPATING VISIBILITIES DROPPING BELOW VFR WITH THESE SHOWERS...
AND THE SHOWERS SHOULD END AROUND 17-18Z AS THEY LIFT NORTH OF
KRST. THERE EXISTS THE POSSIBILITY OF MORE SHOWER ACTIVITY AT KRST
FOR THE AFTERNOON AND TONIGHT...DUE TO A COLD FRONT MOVING IN.
CONFIDENCE IS TOO LOW TO INCLUDE ANY ADDITIONAL SHOWERS IN THE
TAF...THOUGH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
345 AM CDT WED MAR 21 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
345 AM CDT WED MAR 21 2012
.SHORT TERM...THROUGH FRIDAY
345 AM CDT WED MAR 21 2012
FOCUS IS ON RAIN CHANCES THROUGH THE PERIOD ALONG WITH UNSEASONABLY
WARM TEMPERATURES CONTINUING.
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A LARGE CLOSED LOW OVER TX
WITH HIGHLY AMPLIFIED RIDGE OVER THE EASTERN CONUS. DEEP SOUTHERLY
WARM/MOIST FETCH CONTINUES AHEAD OF THE LOW INTO THE UPPER
MISSISSIPPI RIVER VALLEY REGION. AS A RESULT...NATIONAL RADAR MOSAIC
SHOWS LARGE CONVEYOR BELT OF SHRA EXTENDING FROM THE LA GULF COAST
AREA NORTHWARD INTO SOUTHERN IA...THEN TAPERING OFF GOING INTO
NORTHEAST IA/SOUTHEAST MN. MEANWHILE...LOCAL RADAR MOSAIC ALSO
SHOWING FRONTOGENETIC FORCED SHRA ACTIVITY OCCURING ACROSS THE
ARROWHEAD OF MN/NORTHWEST WI...DOWN THROUGH SOUTH CENTRAL MN.
OTHERWISE...EAST OF THE MISSISSIPPI RIVER IN OUR FORECAST AREA...DRY
AND WARM CONDITIONS PREVAILED WITH TEMPERATURES AT 2 AM STILL IN THE
60S.
21.00Z NCEP MODEL SUITE/GEM/ECMWF/20.21Z SREF ALL IN GOOD AGREEMENT
WITH HANDLING OF THE CLOSED LOW COMING OUT OF TX AND ITS AFFECT ON
OUR AREA.
FOR TODAY...WILL CONTINUE TO SEE MOISTURE FEED AHEAD OF THE UPPER
LOW INTO OUR REGION NAM DEPICTING SFC-700MB FRONTOGENESIS REMAINING
NORTHWEST OF OUR AREA FOR FOCUS OF HIGHEST RAIN CHANCES. WITH THIS
IN MIND AND RIDGING OVER THE GREAT LAKES PROVIDING DRYING IN THE
LOWER LEVELS OF THE ATMOSPHERE EAST OF THE MISSISSIPPI RIVER...HAVE
TRIMMED BEST RAIN CHANCES FARTHER NORTHWEST. THIS KEEPS EAST OF A
LINE FROM BLACK RIVER FALLS THROUGH LA CROSSE AND OELWEIN IA DRY FOR
TODAY. THUNDER THREAT WITH THE SHRA ACROSS THE NORTHWEST PARTS OF
THE FORECAST AREA NOT THAT GREAT TODAY AS CAPE IS MINIMAL. DID KEEP
SOME MENTION OF ISOLATED THUNDER IN WITH DECENT FRONTOGENETIC
FORCING. OTHERWISE...LOOKS LIKE ANOTHER UNSEASONABLY WARM DAY TODAY
WITH AREAS VOID OF RAIN TODAY SEEING TEMPERATURES TOPPING OFF IN THE
UPPER 70S.
TONIGHT WILL SEE BEST SHRA CHANCES STAYING ACROSS NORTHWEST HALF OF
THE FORECAST AREA //ROUGHLY NORTHWEST OF A LINE FROM BLACK RIVER
FALLS WI-LA CROSSE WI-OELWEIN IA// WITH LINGERING AREA OF 850-700MB
FRONTOGENESIS.
FOR THURSDAY THROUGH FRIDAY...WILL SEE THAT CLOSED LOW OVER
THE SOUTHERN PLAINS LIFT NORTHEAST INTO MO. THIS SWINGS A BAND OF
MAINLY SHRA NORTHEASTWARD INTO THE AREA. DID INCLUDE ISOLATED
THUNDER MENTION DURING THE DAY THURSDAY AS THE NAM DEPICTS 0-1KM ML
CAPE AROUND 800J/KG DURING THE DAY THURSDAY. FRIDAY LOOKS A BIT MORE
DOUBTFUL FOR THUNDER WITH VERY LIMITED CAPE...BUT OPTED TO KEEP IT
IN FOR NOW. OTHERWISE...LOOKS LIKE RAIN TOTALS POTENTIALLY RUNNING
FROM 1/4 TO 3/4 OF AN INCH.
MAINTAINED SOME SLIGHT CHANCE OF SHRA FRIDAY NIGHT AS THE CLOSED LOW
LIFTS INTO IL AND CYCLONIC FLOW AFFECTS THE AREA.
TEMPERATURE-WISE THURSDAY THROUGH FRIDAY...TEMPERATURES SHOULD TOP
OFF IN THE MID 60S TO LOWER 70S ON THURSDAY BEFORE TH RAIN SETS
IN...AND THEN COOL INTO THE LOWER AND MIDDLE 60S ON FRIDAY WITH
LIKELIHOOD OF RAIN AND CLOUD COVER.
.LONG TERM...SATURDAY THROUGH TUESDAY
345 AM CDT WED MAR 21 2012
21.00Z GFS/ECMWF SHOWS THE CLOSED LOW MOVES ACROSS IL ON SATURDAY
WITH COOLER/CYCLONIC FLOW ALOFT AFFECTING OUR AREA ALONG WITH A
SLIGHT CHANCE OF -SHRA. AS THE CLOSED LOW SHIFTS EAST OF TH REGION
ON SUNDAY...UPPER LEVEL RIDGING BUILDS INTO THE AREA FOR DRY AND
WARMER CONDITIONS. LOOK FOR TEMPERATURES TO REBOUND BACK INTO THE
60S TO LOWER 70S. MONDAY COULD SEE THE POTENTIAL FOR A RATHER STEEP
NORTHEAST TO SOUTHWEST TEMPERATURE GRADIENT ACROSS THE AREA. THIS IS
DUE TO SURFACE HIGH PRESSURE BUILDING SOUTH OUT OF ONTARIO INTO THE
GREAT LAKES REGION. COOLER NORTHEAST FLOW HAS THE POTENTIAL FOR
HOLDING TEMPERATURES AROUND 60 OVER NORTH CENTRAL WI...TO NEAR 80
DEGREES ACROSS PARTS OF NORTHEAST IOWA. IN ADDITION...THERE IS THE
POTENTIAL FOR SOME SHOWERS ACROSS PORTIONS OF THE AREA IN ISENTROPIC
LIFT AHEAD OF LOW PRESSURE OVER THE NORTHERN PLAINS. SHRA/TS CHANCE
ENTER THE PICTURE MONDAY NIGHT/TUESDAY AS THE LOW OVER THE NORTHERN
PLAINS PUSHES TOWARD THE AREA.
&&
.AVIATION...THROUGH 06Z THURSDAY
1138 PM CDT TUE MAR 20 2012
SCATTERED SHOWERS THAT MOVED ACROSS PORTIONS OF NORTHEAST IOWA AND
SOUTHEAST MINNESOTA THIS EVENING ARE NOW LIFTING TO THE NORTH OF
THE AREA. REGIONAL RADARS SHOWING A BREAK IN THE SHOWERS WITH THE
NEXT POTENTIAL ROUND OVER NORTHERN MISSOURI AND EXTREME SOUTHERN
IOWA. THESE SHOWERS ARE EXPECTED TO LIFT NORTH THROUGH THE NIGHT
AS THE LOW LEVEL MOISTURE TRANSPORT INCREASES. THERE WILL ALSO BE
SOME WEAK ISENTROPIC UP GLIDE WITH THIS MOISTURE TRANSPORT WITH
THE 21.00Z NAM SHOWING BETWEEN 3 AND 5 UBAR/S ON THE 300K SURFACE.
THE NAM BRINGS THESE SHOWERS INTO KRST LATE TONIGHT ON THE NOSE OF
THE LOW LEVEL MOISTURE TRANSPORT BUT THE HRRR HAS BEEN
CONSISTENTLY SUGGESTING THESE WILL WEAKEN AS THEY LIFT NORTH
OVERNIGHT. THE 21.01Z RUN BRINGS JUST SOME SCATTERED SHOWERS
THROUGH NORTHEAST IOWA AND SOUTHEAST MINNESOTA AROUND DAYBREAK.
FOR NOW...HAVE CONTINUED WITH JUST A MENTION OF VICINITY SHOWERS
FOR KRST WHILE KEEPING KLSE DRY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
345 AM CDT WED MAR 21 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1139 PM CDT TUE MAR 20 2012
.SHORT TERM...THROUGH FRIDAY
340 PM CDT TUE MAR 20 2012
MOST OF THE WORK TODAY CENTERED AROUND TRYING TO FORECAST THE
PROPER RAIN CHANCES...LOCATION AND TIMING THROUGH THURSDAY. THE
MAIN ISSUE IS WEAK FORCING WITH SOME INSTABILITY AROUND...AND
MODELS WANTING TO GENERATE PRECIPITATION FAIRLY LIBERALLY.
AT 19Z...A NORTHERN JET STREAM BRANCH SHORTWAVE TROUGH HAS
PROGRESSED A COLD FRONTAL BOUNDARY INTO CENTRAL MN AND IA...JUST
WEST OF I-35. THIS WILL BE A FOCAL POINT FOR EVENING RAINFALL.
MEANWHILE A SURFACE LOW IS SHIFTING NORTH THROUGH WRN MO WITH
STRONG LOW-LEVEL FLOW THROUGH IL AND ERN MO WITH 40KTS AT 850 MB
RIDING NORTHWARD INTO THE PROGRESSING FRONT IN MN. MOST OF THE
LOCAL AREA HAS BEEN UNDER RIDGE BUILDING TODAY AS THE STRONG
CLOSED LOW OVER TX IS SLOW TO MOVE. TEMPERATURES AGAIN HAVE
ROCKETED TO 80F IN SWRN WI WHERE FORCING IS MINIMAL AND SKIES ARE
MOSTLY SUNNY. 0-3KM MU CAPES ARE AROUND 400 J/KG IN SWRN WI AS
DEWPOINTS ARE WELL MIXED /AND LOWERED/ IN A 1-1.5 KM DEEP
BOUNDARY LAYER. THERMAL GRADIENT IS PRESENT IN THE LOWEST 300 MB
AGL WITH AN 8C 925MB CHANGE FROM KABR-KMPX IN MORNING RAOBS. ALSO
STARTING TO SEE A CONVERGENCE BOUNDARY FROM BLACK RIVER FALLS TO W
OF KLSE..TO NEAR KCCY.
HAVE BEEN DECREASING RAIN CHANCES ALL DAY TODAY AS THE FORCING IS
REALLY MINIMAL AS LOW-LEVEL WEAK RIDGING OCCURS. THIS HAS CLEARED
OUT ERN IA AND MO OF MOST CLOUD. MODEL GUIDANCE...INCLUDING HRRR
CONTINUES TO PROVIDE WET GUIDANCE IN THE WESTERN FORECAST AREA BUT
THE DETAILS ON THE LOW-LEVEL CONVERGENCE HAVE BEEN HANDLED VERY
POORLY AND TOO FAR EAST...THUS NO PRECIPITATION. INDICATIONS
CONTINUE IN THE 20.12Z NAM/GFS AND LATEST 20.18Z RUC THAT THE
FRONTAL BOUNDARY WILL BECOME ACTIVE TONIGHT NEAR I-35 WITH
MODERATE FRONTOGENESIS OVER THE FAR WRN FORECAST AREA. RUN-TO-RUN
TRENDS IN THE RUC HAVE BEEN CONSISTENT WITH PLACEMENT AND EVENING
INCREASE IN RAIN CHANCES. THIS WILL COMBINE WITH THE SURFACE LOW
SHIFTING NORTH FROM MO AND LOW-LEVEL MOISTURE TRANSPORT OVERNIGHT
TO CAUSE A GOOD CHANCE OF RAIN.
BIG CHALLENGE IS HOW FAR WEST OR EAST WILL THIS BAND SET UP.
BELIEVE THE EAST EXTENT OF THE RAIN BAND WILL AFFECT THE WESTERN
FORECAST AREA. WITH FRONTAL ZONE ACTIVE AND INSTABILITY ALOFT
ABOVE THE ZONE...COULD SEE SHOWER ACTIVITY EXTEND EAST TO MISS
RIVER. THERE ARE SOME CONSISTENT SIGNALS THAT A SECOND SURGE OF
MOISTURE TRANSPORT AND CONVERGENCE WILL MOVE INTO THE FRONT FROM
THE SOUTH LATE TONIGHT TO ENHANCE THE RAIN CHANCES A BIT FURTHER
EAST TOO. THIS IS LOW- LEVEL JET FORCED. MOST OF WI SHOULD REMAIN
DRY.
SEVERE CHANCES WOULD BE BEST IN WI WHERE CAPE IS BUILDING. BUT
THERE IS LITTLE FORCING IN THIS AREA...EXCEPT FOR DEVELOPING
CONVERGENCE BOUNDARY THAT WILL HAVE TO BE MONITORED. ALSO...SHOULD
CONVECTION INITIATE AND FORM INTO A LINE SEGMENT OVER ERN
IA...THERE MAY BE A BETTER CHANCE FOR SEVERE CONVECTION AS IT
MOVES INTO WI. OVERALL WIND SHEAR IS QUITE FAVORABLE TODAY...BUT
FORCING IS WEAK IN THE INSTABILITY AREA. WILL MONITOR THIS
EVENING.
THE ACTIVITY OVERNIGHT SHOULD LIFT NORTH WEDNESDAY DURING THE
MORNING AS THE FORCING DOES AS WELL. THINKING A VERY SIMILAR DAY
TO TODAY WITH SWRN WI POSSIBLY NEAR 80F AGAIN AND BUILDING CAPE.
CONSENSUS OF THE FORECAST GUIDANCE HAS THE WARM CONVEYOR BELT AND
MOISTURE TRANSPORT MOVING IN THURSDAY AS THE CLOSED LOW SHIFTS
NORTHEAST. WOULD THINK MOST AREAS WILL SEE ABOUT 0.25 INCHES
THURSDAY FROM THIS FRONT. WILL HAVE TO WATCH FOR INSTABILITY
GROWING AHEAD OF THE FRONT THURSDAY AFTERNOON FOR POSSIBLE SEVERE
THREATS. BAND FREEZES IN ERN WI AS THE UPPER LOW HALTS ITS
NORTHEAST PROGRESSION.
.LONG TERM...SATURDAY THROUGH TUESDAY
340 PM CDT TUE MAR 20 2012
CLOSED LOW WILL SHIFT IN AND AFFECT THE AREA THROUGH SATURDAY
MID-DAY...THEN HIGH AMPLITUDE RIDGE BUILDING KICKS IN....AGAIN.
MODEL CONSENSUS ON THE NRN STREAM SHORTWAVE MOVING NE OF THE GREAT
LAKES IS BETTER THAN YESTERDAY WITH ABOUT A 2C SPREAD AT 850MB
SUNDAY AFTERNOON. THUS...CONFIDENCE IS GROWING ON THOSE FORECASTS
IN THE 60-65F RANGE. GFS SUITE STILL MORE AGGRESSIVE ON WARMING FOR
MONDAY AND HAVE CHOSEN TO BE CONSERVATIVE THERE...WITH COOLER
20.12Z ECMWF. HAVE INTRODUCED PRECIPITATION CHANCES MONDAY AGAIN
AS THE RETURN FLOW IN THE DAKOTAS SHIFTS EAST TOWARD THE
AREA...LIKE IN THE MONTH OF MAY. THUS...THE FRONTAL BOUNDARY OVER
THE AREA WILL RETREAT NORTH AS A WARM FRONT BUT BE WORKED ON
SOMEWHAT FOR RAIN CHANCES. TEMPERATURES TUESDAY MAY NEED TO BE
INCREASED SHOULD COLD FRONTAL TIMING VIA STRONG SWRN U.S. TROUGH
&&
.AVIATION...THROUGH 06Z THURSDAY
1138 PM CDT TUE MAR 20 2012
SCATTERED SHOWERS THAT MOVED ACROSS PORTIONS OF NORTHEAST IOWA AND
SOUTHEAST MINNESOTA THIS EVENING ARE NOW LIFTING TO THE NORTH OF
THE AREA. REGIONAL RADARS SHOWING A BREAK IN THE SHOWERS WITH THE
NEXT POTENTIAL ROUND OVER NORTHERN MISSOURI AND EXTREME SOUTHERN
IOWA. THESE SHOWERS ARE EXPECTED TO LIFT NORTH THROUGH THE NIGHT
AS THE LOW LEVEL MOISTURE TRANSPORT INCREASES. THERE WILL ALSO BE
SOME WEAK ISENTROPIC UP GLIDE WITH THIS MOISTURE TRANSPORT WITH
THE 21.00Z NAM SHOWING BETWEEN 3 AND 5 UBAR/S ON THE 300K SURFACE.
THE NAM BRINGS THESE SHOWERS INTO KRST LATE TONIGHT ON THE NOSE OF
THE LOW LEVEL MOISTURE TRANSPORT BUT THE HRRR HAS BEEN
CONSISTENTLY SUGGESTING THESE WILL WEAKEN AS THEY LIFT NORTH
OVERNIGHT. THE 21.01Z RUN BRINGS JUST SOME SCATTERED SHOWERS
THROUGH NORTHEAST IOWA AND SOUTHEAST MINNESOTA AROUND DAYBREAK.
FOR NOW...HAVE CONTINUED WITH JUST A MENTION OF VICINITY SHOWERS
FOR KRST WHILE KEEPING KLSE DRY.
&&
.FIRE WEATHER...
340 PM CDT TUE MAR 20 2012
WHILE FUELS ARE STILL DRY AND READY TO BURN...WEATHER CONDITIONS
WILL HOLD IN A MINIMAL THREAT REGIME AS THE WEAK CONTINUES.
WEDNESDAY WILL PROVIDE MIN RH VALUES NEAR 50 PERCENT OVER CENTRAL
WI WHICH IS NOT OVERLY FAVORABLE FOR SPREADING FIRE. HOWEVER...A
WILDFIRE WAS REPORTED IN GREEN LAKE COUNTY TODAY IN CENTRAL
WI...AND THIS AREA IS THE MOST FAVORABLE FOR FIRE ACTIVITY
WEDNESDAY. A WETTING RAIN IS EXPECTED THURSDAY TO HELP REDUCE THE
FUEL VOLATILITY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
344 PM CDT TUE MAR 20 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...04
FIRE WEATHER...BAUMGARDT
AREA FORECAST DISCUSSION
NWS DES MOINES IA
351 AM CDT FRI MAR 23 2012
.SHORT TERM /TODAY/...
BIGGEST FOCUS TODAY WILL BE ON FOG THIS MORNING...AND THEN CHANCES
FOR SHOWERS ACROSS THE SOUTHERN CWA. FOG HAS DEVELOPED ACROSS MUCH
OF THE CWA...MAINLY NORTH AND EAST OF A LINE FROM OTTUMWA...TO DES
MOINES...TO CARROLL. FOG EXPECTED TO PERSIST ACROSS THE AREA INTO
THE MID MORNING HOURS...WITH WINDS EXPECTED TO REMAIN LIGHT AND
CONTINUE TO HAVE MOISTURE NEAR SURFACE CONDITIONS DUE TO RESIDUAL
MOISTURE FROM RAINFALL OVER THE PAST FEW DAYS. MAJORITY OF VSBYS
RANGING FROM NEAR ZERO TO AROUND ONE QUARTER MILE AND ARE ONLY
EXPECTED TO WORSEN THROUGH SUNRISE...WITH THE HRRR KEEPING VSBYS AT
A QUARTER MILE OR BELOW THROUGH 15Z. THEREFORE HAVE OPTED TO ISSUE A
DENSE FOG ADVISORY FOR MUCH OF THE CWA THROUGH 15Z. FOG SHOULD THEN
LIFT INTO SOME LOW STRATUS AND THEN BREAK UP SOME BY LATE MORNING
INTO THE EARLY AFTERNOON HOURS. WITH THE UPPER LOW CHURNING TO THE
SOUTH OF THE CWA...AND CONTINUED CYCLONIC FLOW OVER THE STATE...DO
NOT EXPECT SKIES TO CLEAR COMPLETELY TODAY...WITH SOME SHOWERS
POSSIBLE ACROSS SOUTHERN CWA THROUGHOUT THE DAY AS BANDS OF LIGHT
SHOWERS CONTINUE TO ROTATE NORTHWARD FROM MISSOURI AROUND MAIN LOW
TO THE SOUTH OF THE CWA. ANY PRECIP ROTATING BACK INTO THE AREA
ACROSS NORTHEASTERN CWA APPEARS TO HOLD OFF UNTIL AFTER 00Z. WITH
H85 TEMPERATURES AROUND +9C...A COOLER START TO THE DAY...AND CLOUD
COVER/LINGERING FOG HAVE TEMPS IN THE UPPER 60S TO AROUND 70.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
THOUGH THE UPPER LOW CENTER IS CURRENTLY OVER FAR SOUTHEAST
KANSAS...THE STRONGEST PV ANOMALY ASSOCIATED WITH THE SYSTEM IS
ROUNDING THROUGH CNTRL ARKANSAS. THIS WILL HELP KEEP THE UPPER LOW
ON A MORE SOUTHERLY TRACK BY THIS EVENING AS IT TRACKS INTO THE
LOWER OHIO VALLEY. ONE FINAL PIECE OF ENERGY WILL WRAP AROUND THE
SYSTEM AND INTO EASTERN AS THE SYSTEM DEPARTS TONIGHT. THIS WILL
BRING ONE LAST CHANCE FOR SHOWERS EAST OF INTERSTATE 35. THE AREA
WILL QUICKLY TRANSITION OUT OF CYCLONIC FLOW ON SATURDAY WITH
RIDGING BUILDING IN FROM THE WEST. DESPITE NW FLOW...SOME SFC WARM
ADVECTION WILL BE TAKING PLACE. THE NW FLOW WILL ALSO AID DESCENT
MIXING AND THERE SHOULD BE AN ABUNDANCE OF SUNSHINE CENTRAL AND WEST
WITH A FEW CLOUDS LINGERING OVER THE EAST. A WEAK FRONTAL BOUNDARY
WILL REACH THE NORTHERN THIRD OF THE STATE SATURDAY NIGHT AND SUNDAY
THOUGH THE GREATEST IMPACTS WILL MOVE THROUGH PORTIONS OF MINNESOTA
AND WISCONSIN. SHOULD BE A PLEASANT DAY OVERALL WITH HIGHS IN THE
60S AND 70S WITH LIGHT WINDS.
THE MONDAY FORECAST CONTINUES TO BECOME MORE COMPLEX. THE
AFOREMENTIONED COLD ADVECTION THROUGH WISCONSIN SUNDAY WILL SHIFT
WEST AS A BACK DOOR COLD FRONT OFF LAKE MICHIGAN SUNDAY NIGHT AND
MONDAY. WARM ADVECTION WILL BE LIFTING INTO WESTERN IOWA BY MONDAY
MORNING HOWEVER ITS EASTWARD ADVANCE WILL LIKELY BE OVERCOME BY THE
COOLER AND MORE DENSE AIR FILTERING IN FROM THE EAST. HIGH
TEMPERATURES AT THIS POINT COULD BE TOO HIGH BY SEVERAL DEGREES IF
THE THIS BOUNDARY COMES IN AS STRONG AS SUGGESTED. DESPITE
THIS...MID LEVEL WARM ADVECTION WILL CONTINUE TO OVERSPREAD THE AREA
MONDAY WITH SOME INSTABILITY DEVELOPING AHEAD OF THE LOW LEVEL JET
AND STRONG THETA E ADVECTION. BEST POTENTIAL FOR THUNDERSTORMS WOULD
BE OVER THE NORTH. ANY THUNDER AT THIS TIME LIKELY WILL BE ELEVATED
THOUGH A MARGINAL SEVERE STORM WOULD BE POSSIBLE. BOWLING BALL UPPER
LOW LIFTING INTO THE NORTHERN PLAINS ON TUESDAY COULD PRODUCE SOME
INTERESTING WEATHER TUESDAY PENDING EXACT TIMING AND PLACEMENT OF
THE SYSTEM. COOLER AIR WILL SINK IN BEHIND THE SYSTEM THOUGH AGAIN
THE GREATEST IMPACT WILL BE TO THE NORTHEAST. TEMPERATURES WILL
REMAIN WELL ABOVE SEASONAL VALUES WITH LOW POTENTIAL FOR
PRECIPITATION WEDNESDAY AND THURSDAY.
&&
.AVIATION...23/06Z
PRIMARY AVN CONCERN WILL BE FOG AND LOW STRATUS
OVERNIGHT...PRODUCING LIFR/VLIFR CONDITIONS AT TIME PRIMARILY AT
KFOD/KMCW/KALO. CURRENTLY VSBYS ARE BOUNCING EVERYWHERE BTWN M1/4SM
AND P6SM HOWEVER SAT IMAGERY INDICATES THAT HIGH CLOUD COVERAGE IS
INCREASING AND BELIEVE THIS WILL TEMPER VSBYS SOMEWHAT LATER
TONIGHT...KEEPING THINGS MAINLY MVFR/IFR. CONFIDENCE IS LOW AND HAVE
USED TEMPOS TO COVER SOME OF THIS UNCERTAINTY AND VSBY BOUNCING AT
KFOD/KMCW. ON FRI MORNING CONDITIONS WILL IMPROVE BY LATE AM AS FOG
DISSIPATES...BUT SOME MVFR CIGS AND ISOLD -SHRA WILL STILL BE
POSSIBLE DURING THE DAY.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR BLACK HAWK-
BOONE-BREMER-BUTLER-CALHOUN-CARROLL-CERRO GORDO-EMMET-FRANKLIN-
GREENE-GRUNDY-HAMILTON-HANCOCK-HARDIN-HUMBOLDT-JASPER-KOSSUTH-
MARSHALL-PALO ALTO-POCAHONTAS-POWESHIEK-SAC-STORY-TAMA-WEBSTER-
WINNEBAGO-WORTH-WRIGHT.
&&
$$
SHORT TERM...BEERENDS
LONG TERM...DONAVON
AVIATION...LEE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
325 AM CDT FRI MAR 23 2012
.SYNOPSIS...
06Z SFC ANALYSIS HAS NUMEROUS WEAK LOWS ACROSS THE MIDWEST ALONG
WITH ASSOCIATED TROFS. A WEAK LOW WAS NORTHEAST OF KDSM WITH A TROF
RUNNING SOUTHEAST TO KEVV. ANOTHER TROF RAN FROM CENTRAL INDIANA
NORTHWEST INTO SOUTHERN MINNESOTA. THE OCCLUDED LOW ASSOCIATED WITH
THE UPPER LOW WAS NEAR KCNU WITH TROFS RADIATING OUT FROM IT. DEW
POINTS WERE GENERALLY IN THE 40S AND 50S ACROSS THE MIDWEST.
RADAR TRENDS SHOW THE MAIN PRECIP GENERALLY NORTH OF A LINE FROM
KRST TO KVYS WHICH WAS ASSOCIATED WITH A VORT MAX ROTATING AROUND
THE UPPER LOW.
&&
.SHORT TERM...TODAY AND TONIGHT...
A VERY INTERESTING FCST WITH INTERACTIONS BOTH UP AND DOWN ON
VARIOUS SCALES ALONG WITH NONLINEAR PROCESSES. THE RUC WAS VERY
USEFUL IN ESTABLISHING OVERALL NEAR TERM TRENDS.
THE MCS AND LIFT TOOLS ALONG WITH THE HEAVY RAIN TOOL DO A NICE JOB
OF DEPICTING THE CURRENT PRECIPITATION ACROSS THE AREA. THE PRECIP
IS JUST EAST OF THE MAIN THETA E GRADIENT AND THE RUC HAS THIS
GRADIENT SLOWLY MOVING TO THE NORTH AND EAST THROUGH 12Z. THUS THE
CURRENT PRECIP WILL SLOWLY MOVE OUT OF THE AREA. THE PARTIAL
CLEARING THAT HAS OCCURRED IN THE DIRTY DRY SLOT HAS ALLOWED FOG TO
DEVELOP WITH IT LOCALLY THICK IN AN AREA OF WEAK CONVERGENCE ACROSS
SOUTHEAST IOWA. A FEW GROUND TRUTH REPORTS INDICATE IT IS VERY
SHALLOW. SO WILL CONTINUE TO MONITOR FOR TRENDS BUT WILL HIGHLIGHT
FOG THREAT WITH ANOTHER SPS.
ANY PRECIPITATION SHOULD BE CONFINED TO THE FAR NORTHEAST/EAST PARTS
OF THE CWFA THROUGH MID MORNING BEFORE DIFFERENTIAL HEATING BEGINS
TO PRODUCE SOME ISOLD SHRA ACROSS THE REMAINDER OF THE AREA. LIFT
AND HEAVY RAIN TOOLS SUGGEST A CONSIDERABLE AMOUNT OF NEW CONVECTION
SHOULD BE ACROSS NORTHEAST ILLINOIS AT MID DAY WITH ANOTHER VORT
MAX. LIFT TOOL HAS A THETA E GRADIENT ACROSS ROUGHLY THE SOUTHEAST
HALF OF THE CWFA DURING THE AFTERNOON WITH CONVERGENCE INCREASING.
THUS SHOWERS WITH TSRA WILL BE MOST PREVALENT ACROSS ROUGHLY THE
SOUTHERN HALF OF THE CWFA.
CONVECTION WILL CONTINUE INTO THE EVENING HOURS WITH IT MOST
NUMEROUS ACROSS THE SOUTHERN HALF OF THE CWFA. SUNSET WILL ALLOW THE
ATMOSPHERE TO RE-STABILIZE SO CONVECTION WILL DIMINISH DURING THE
EVENING. MCS AND LIFT TOOLS SUGGEST CONVECTION MAY PERSIST OR EVEN
RE-DEVELOP AFTER MIDNIGHT ACROSS THE NORTHWEST THIRD TO HALF OF THE
CWFA WITH CONVERGENCE INCREASING THERE AS ANOTHER VORT MAX ROTATES
AROUND THE UPPER LOW. ..08..
.LONG TERM...SATURDAY THROUGH NEXT THURSDAY...
MOSTLY DRY TO DRY WITH TEMPERATURES STILL ABOVE NORMAL BY AT LEAST
SEVERAL DEGREES IF NOT MORE ALL DAYS....THOUGH NOT RECORD WARMTH.
OVERALL...INITIALIZATION GOOD WITH UPSTREAM ENERGY AND VERIFICATION
AND RUN TO RUN CONTINUITY SUPPORTING A 50/50 BLEND OF GFS/HI-RES
ECMWF. LIMITED SENSIBLE IMPACTS WITH SOME LIGHT TO LOCALLY MODERATE
RAIN AMOUNTS POSSIBLY WITH BACKDOOR COLD FRONT MONDAY INTO TUESDAY
AHEAD OF NEXT SHORT WAVE. PERSISTENCE SUGGEST GUIDANCE TEMPS MAY
STILL BE A FEW DEGREES TOO COOL FOR LATER SHIFTS TO CONSIDER MOST
DAYS EXCEPT MONDAY WHEN BACKDOOR FRONT MAY BE COLDER WITH GOOD
ADVECTION FROM NE WINDS OFF LAKE MICHIGAN.
SATURDAY...KEPT LOW POPS WITH CONVECTIVE TEMPERATURE REACHED FOR
MOSTLY PM POPCORN -SHRA. OTHERWISE...PARTLY SUNNY AND MILD WITH
HIGHS MAINLY 70 TO 75 DEGREES WITH LIGHT WINDS. SATURDAY NIGHT...
CLEARING AND A BIT COLDER WITH MINS AROUND 50 DEGREES BUT LIGHT
WIND SUGGEST LATER SHIFTS MAY NEED TO TRIM AT LEAST A FEW DEGREES
WITH GOOD BL DECOUPLING.
SUNDAY...ANOTHER SPLENDID LATE MARCH DAY AHEAD OF BACKDOOR COLD
FRONT WITH HIGHS WELL INTO THE 70S AND LIGHT NORTH WINDS. SUNDAY
NIGHT...BACKDOOR ARRIVES BY LATE EVENING WITH NE WINDS OF 10-20+
MPH SUGGESTED. WENT WITH MINS OF LOWER 40S NE TO LOWER 50S SW BUT
LATER SHIFTS MAY NEED TO TRIM AT LEAST A COUPLE MORE DEGREES MOST
LOCATIONS. WITH OUR EXTENDED MILD WEATHER...THIS WILL FEEL COLDER
THAN ONE WOULD EXPECT FOR LATE MARCH TO MANY.
MONDAY THROUGH TUESDAY...LOCAL TECHNIQUES SUGGEST NE SECTIONS MAY
STRUGGLE WITH IDEAL FETCH OFF LAKE MICHIGAN IN NE 1/2 OF AREA TO
REACH THE MIDDLE 50S WITH GUSTY NE TO E WINDS OF 15-25+ MPH. LOW
CLOUDS ALSO MAY RESULT IN GREATER IMPACT OF A COOL DAY. NEXT SHORT
WAVE MAY SPAWN LIGHT RAIN AND RAIN SHOWERS MONDAY NIGHT INTO TUESDAY.
THE STRENGTH OF FORCING SHOULD BE BETTER ASCERTAINED NEXT 12-24
HOURS. TUESDAY WARM FRONT SHOULD PASS BY MID DAY FOR TEMPERATURES
BACK INTO THE 70S AND MINS TUESDAY NIGHT UPPER 40S TO LOWER 50S WITH
-SHRA/-TSRA ENDING PROBABLY BY MIDNIGHT WITH PASSAGE OF COLD FRONT.
ANY STORMS ATTM PROBABLY NON-SEVERE DUE TO LIMITED FORCING AND
INSTABILITY.
WEDNESDAY AND THURSDAY...MAINLY DRY WITH WEAK HIGH PRESSURE AND ONLY
A BIT COOLER WITH HIGHS IN THE 60S AND MINS IN THE 40S. THIS IS
STILL 10 PLUS DEGREES ABOVE NORMAL AS OUR REMARKABLE EXTENDED PERIOD
OF MARCH WARM SPELL CONTINUES. ..NICHOLS..
&&
.AVIATION...
VFR TO VLIFR CONDITIONS WILL BE SEEN THROUGH SUNRISE WITH CONDITIONS
IMPROVING TO VFR. DAYTIME HEATING WILL ALLOW ANOTHER ROUND OF SHRA
WITH TSRA TO DVLP WITH CONVECTION BEING MOST NUMEROUS DURING THE
AFTERNOON. CONVECTION WILL DISSIPATE WITH SUNSET BUT MAY LINGER
THROUGH THE NIGHT ACROSS EASTERN IOWA. KMLI/KBRL MAY HAVE THE BEST
CHANCE AT SEEING TSRA WITH MVFR CONDITIONS AFT 18Z/23 AND WILL GO
WITH VCTS IN THE 12Z TAFS. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
08/NICHOLS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1230 AM CDT FRI MAR 23 2012
...UPDATED AVIATION SECTION...
.UPDATE...
ISSUED AT 741 PM CDT THU MAR 22 2012
HAVE PULLED POPS AND WX OUT OF THE GRIDS AS KDDC WSR-88D IS NOT INDICATING
ANY RETURNED POWER AT 0.50 DEG AND HIGHER. CLOUD TOPS PER IR SATELLITE
CHANNEL HAVE BEEN WARMING ACROSS THE CENTRAL AND EASTERN SECTIONS OF
THE CWFA AS WELL. LASTLY, THE 00Z KDDC RAOB SHOWED WARMING AND DRYING
THROUGH THE ATMOSPHERIC COLUMN WITH THE PWAT AT 0.51 INCHES NOW. AM
WATCHING A BAND OF PRECIPITATION ACROSS EASTERN COLORADO ASSOCIATED
WITH THE MAIN UPPER LEVEL LOW FURTHER TO THE SE. THE HRRR HAS PICKED
UP WELL ON THIS FEATURE. HAVE DOUBTS ANY PRECIPITATION WILL REACH THE
GROUND ACROSS FAR WESTERN KANSAS AS THIS MOISTURE LOOKS CONFINED MAINLY
TO THE LOWER TO MID LEVELS AROUND 700 TO 500 HPA.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 343 PM CDT THU MAR 22 2012
MAIN SHORT TERM CHALLENGES TONIGHT WILL BE THE TIMING OF THE END OF
PRECIPITATION. INDICATIONS FROM THE RUC, HRRR, AND NAM12 WOULD SEEM
TO INDICATE THAT THE SHOWER ACTIVITY WILL BE WANING OVER THE NEXT
COUPLE OF HOURS. POPS WILL BE RAPIDLY DECREASING IN THE GRIDS WITH
SLIGHT CHANCE POPS GONE BY 01-02Z OR SO IN THE SOUTHEAST ZONES. THE
FOCUS THEN WILL TURN TO THE FOG DEVELOPMENT. SKIES ARE EXPECTED TO
CLEAR (OR AT LEAST BECOME MOSTLY CLEAR)...ESPECIALLY AFTER 06Z
TONIGHT...AND WITH LIGHT WINDS AT 6 KNOTS OR LESS AND SATURATED
GROUNDS...THE STAGE WILL BE SET FOR FOG FORMATION AS TEMPERATURES
FALL INTO THE MID TO UPPER 30S. WILL BE ADDING AREAS OF FOG TO THE
GRIDS FOR THE 09-14Z TIME FRAME. ON FRIDAY...ONCE THE FOG CLEARS
(IF IT DEVELOPS AS FORECAST) SHORTWAVE RIDGING WILL ADVANCE ON THE
WESTERN PLAINS FROM THE ROCKIES. THE LOW LEVEL RIDGE AXIS WILL
REMAIN OVER WESTERN KANSAS THROUGH THE DAY FRIDAY AND THIS WILL
YIELD LIGHT WINDS ALL DAY AT 6 KNOTS OR LESS. LOW LEVEL THICKNESSES
WILL STILL BE FAIRLY LOW WITH THE UPPER LOW NOT ALL THAT FAR REMOVED
FROM THE PLAINS...SO TEMPERATURES WILL MAX OUT IN THE MID 60S FOR
MOST LOCATIONS...AND LOWER 70S ACROSS FAR SOUTHWEST ZONES WHERE
THICKNESSES WILL BE INCREASING AT A QUICKER RATE WITH THE SHORTWAVE
RIDGE APPROACHING.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 131 PM CDT THU MAR 22 2012
MUCH WARMER AIR WILL RETURN TO WESTERN KANSAS FRIDAY AS THE
UPPER-LEVEL LOW DISCUSSED IN THE SHORT TERM DISCUSSION MOVES INTO
MISSOURI AND SUNSHINE RETURNS. HIGHS SHOULD WARM INTO THE LOWER
TO MID 70S. THE WARM TEMPERATURES WILL PERSIST THROUGH NEXT WEEK
AS UPPER-LEVEL TROUGHING DEVELOPS ACROSS THE WESTERN UNITED
STATES, AND SURFACE LEE TROUGHING DEVELOPS ACROSS THE HIGH PLAINS.
A SHORTWAVE TROUGH WILL PASS ACROSS THE NORTHERN PLAINS BY MONDAY
NIGHT AND TUESDAY. THE GFS/GEM AND ECMWF WERE GENERALLY FOLLOWED
WITH THIS SYSTEM. DESPITE SOME SUBTLE MODEL DIFFERENCES, THE
BOTTOM LINE IS THAT THE UPPER-LEVEL SYSTEM WILL PASS TO OUR NORTH,
WITH LITTLE IN THE WAY OF SYNOPTIC SCALE LIFT OVER WESTERN KANSAS.
TEMPERATURES COULD POSSIBLY REACH INTO THE MID 80S BEHIND THE
DRYLINE IN FAR WESTERN KANSAS MONDAY. RICH LOW-LEVEL MOISTURE
WILL BE DRAWN NORTHWARD ALONG AND EAST OF THE 100TH MERIDIAN IN
ADVANCE OF THE SYSTEM. OFTENTIMES IN MARCH, STRONG FRONTS PUSH THE
LOW-LEVEL MOISTURE DEEP INTO THE TROPICS. BUT SO FAR THIS MARCH WE
HAVE HAD NO PROBLEM GETTING RICH MOISTURE BACK FROM THE GULF IN
THE ABSENCE OF STRONG FRONTAL PASSAGES. A DRYLINE WILL SET UP
ACROSS WESTERN KANSAS MONDAY, WITH AN UNSTABLE AIRMASS DEVELOPING
IMMEDIATELY AHEAD OF IT. HOWEVER, THUNDERSTORMS MAY NOT DEVELOP
SINCE THE ASSOCIATED UPPER-LEVEL JET AND MID-LEVEL COOLING WILL
PASS TO OUR NORTH. BUT AN ISOLATED LATE DAY THUNDERSTORM CANNOT BE
COMPLETELY RULED OUT. AFTER THIS SYSTEM PASSES, THE ASSOCIATED
WEAK COLD FRONT WILL MOVE THROUGH SOUTHWEST KANSAS, KNOCKING
TEMPERATURES DOWN ONLY A FEW DEGREES. IN FACT, TEMPERATURES OUGHT
TO REMAIN ABOVE CLIMATOLOGICAL AVERAGES ALL WEEK AS LEE TROUGHING
QUICKLY REDEVELOPS GIVEN THE FAIRLY ZONAL MID-LEVEL FLOW. A
THUNDERSTORM OR TWO COULD DEVELOP ALONG THE TRAILING COLD FRONT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1220 AM CDT FRI MAR 23 2012
NORTHERLY WINDS WILL BECOME LIGHT AND VARIABLE EARLY THIS MORNING
AS AN UPPER LEVEL SYSTEM MOVES INTO THE MISSISSIPPI VALLEY. VFR
CONDITIONS WILL PREVAIL WITH CLOUDS AOA050 DISSIPATING BEFORE
SUNRISE. LIGHT AND VARIABLE WINDS CONTINUE THROUGH THE AFTERNOON
WITH MOSTLY CLEAR SKIES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 41 74 48 78 / 0 0 0 0
GCK 40 76 48 79 / 0 0 0 0
EHA 42 77 48 80 / 0 0 0 0
LBL 41 77 48 79 / 0 0 0 0
HYS 41 76 48 77 / 0 0 0 0
P28 43 74 48 77 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...UMSCHEID
LONG TERM....FINCH
AVIATION...HOVORKA 42
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1010 PM MDT THU MAR 22 2012
.UPDATE...
ISSUED AT 932 PM MDT THU MAR 22 2012
NUDGED POPS UP TO CHANCE CATEGORY ALONG AND WEST OF THE CO/KS
STATE LINE...MAINLY NORTH OF THE INTERSTATE...PER RADAR IMAGES
AND LATEST HRRR WHICH HAS A GOOD HANDLE ON CURRENT LOCATION OF
PRECIPITATION. NO OTHER CHANGES MADE.
UPDATE ISSUED AT 830 PM MDT THU MAR 22 2012
UPDATED TONIGHT THROUGH FRIDAY PERIODS. MAIN ADJUSTMENT WAS TO
INCREASE CLOUD COVER AROUND AN UPPER LOW PRESSURE CENTER CURRENTLY
OVER NORTH CENTRAL OKLAHOMA. AS THIS LOW MOVES EAST-NORTHEAST
TOWARD SOUTHERN MISSOURI FRIDAY CONSIDERABLE WRAPAROUND
CLOUDINESS WILL IMPACT THE WESTERN 1/2-1/3 OF THE AREA THROUGH
FRIDAY MORNING BEFORE DECREASING IN COVERAGE DURING THE AFTERNOON
AS AVAILABLE MOISTURE DECREASES.
AT 0230Z RADAR STILL SHOWING A FEW ECHOES ACROSS FAR WESTERN YUMA
AND KIT CARSON COUNTIES WHERE SOME LIGHT RAIN SHOWERS ARE FALLING.
THIS AREA OF PRECIPITATION CONTINUES TO SLOWLY LOSE ITS INTENSITY
AND AM THINKING THAT BY 06Z OR 09Z AT THE LATEST IT SHOULD BE WEAK
ENOUGH TO REMOVE POP MENTION.
NO CHANGES MADE TO THE FOG FORECAST EARLY FRIDAY MORNING THROUGH
MID MORNING. WINDS LIGHT THROUGH THE NEXT 36 HOURS OR SO. HIGH
TEMPERATURES STILL LOOK TO WARM CLOSE TO 70 DEGREES FOR MANY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 232 PM MDT THU MAR 22 2012
VISIBLE SATELLITE IMAGERY SHOWS CENTER OF LOW JUST SOUTHEAST OF
KP28. A BAND OF LIGHT SHOWERS ON THE NORTHWEST SIDE OF LOW WILL
PERSIST ACROSS THE EASTERN COLORADO COUNTIES THROUGH THE EVENING. AS
THE LOW SLOWLY MOVES EAST...MOISTURE ADVECTION/SHOWERS WILL END. LOW
WILL BE FAR ENOUGH EAST BY 12Z FRIDAY THAT CLOUDS WILL BE ALSO
DECREASE. HOWEVER...THE BOUNDARY LAYER IS QUITE MOIST AFTER
WIDESPREAD RAIN LAST NIGHT...SO AS CLEARING/SURFACE COOLING TAKES
PLACE...FOG WILL FORM. HARD TO PINPOINT EXACTLY WHERE FOG IS MOST
LIKELY TO DEVELOP...BUT WILL BEGIN BY INTRODUCING IT ACROSS THE
WESTERN HALF OF FORECAST AREA AROUND 08Z. EXPECT TEMPERATURES TO
DROP INTO THE MID 30S MOST AREAS TONIGHT.
MODELS AGREE THAT 500 MB RIDGE WILL BUILD OVER THE HIGH PLAINS
FRIDAY AFTERNOON. WARM AIR ADVECTION WILL BEGIN AFTER 18Z...WITH 850
MB TEMPERATURES REACHING 16-18 DEGREES CELSIUS. THUS...EXPECT
MAXIMUM TEMPERATURES TO REACH INTO THE UPPER 60S UNDER MOSTLY SUNNY
SKIES. THERE MAY BE FOG AGAIN FRIDAY NIGHT...BUT WILL SEE HOW FOG
FORMS TONIGHT BEFORE INTRODUCING IT AGAIN.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 232 PM MDT THU MAR 22 2012
A HIGHLY AMPLIFIED RIDGE WILL BE IN PLACE ACROSS THE CENTRAL US
SATURDAY THROUGH MONDAY WITH VERY WARM TEMPERATURES AND DRY
CONDITIONS EXPECTED. HIGH TEMPERATURES WILL GENERALLY RANGE
FROM THE UPPER 70S TO LOW 80S...WITH AFTERNOON TEMPERATURES POSSIBLY
WARMING INTO THE MIDDLE 80S ON MONDAY.
BY MONDAY NIGHT A SHORTWAVE TROUGH WILL PASS ACROSS THE
NORTHERN PLAINS...WITH AN ASSOCIATED COLD FRONT DROPPING SOUTH OVER
THE CWA LATE MONDAY NIGHT. WITH A DRY LINE LINGERING OVER THE CWA AND
DECENT INSTABILITY EAST OF THIS FEATURE MONDAY AFTERNOON THROUGH
MONDAY NIGHT...A FEW THUNDERSTORMS COULDNT BE RULED OUT OVER EASTERN
LOCATIONS. I STILL HAVE CONCERNS THAT A STRONG CAP IN PLACE ACROSS
OUR CWA WILL LIMIT CONVECTIVE POTENTIAL...AND THE OVERALL TREND WITH
GUIDANCE HAS BEEN TO PUSH THE BEST CHANCES FURTHER EAST. OVERALL THE
SYNOPTIC PATTERN HAS BEEN FAIRLY CONSISTENT...SO I DECIDED TO KEEP
SLIGHT CHANCE POPS IN THE EXTREME EASTERN PART OF OUR CWA FOR
ANOTHER FORECAST CYCLE. IF CURRENT TRENDS HOLD THESE POPS COULD
PROBABLY BE REMOVED.
TUESDAY THROUGH THURSDAY...A MORE PROGRESSIVE PATTERN SETS IN BY THE
MIDDLE OF NEXT WEEK. HOWEVER...THE MAIN STORM TRACK REMAINS FAR TO
THE NORTH...SO DRY CONDITIONS SHOULD CONTINUE ACROSS THE
TRI-STATE REGION. TEMPERATURES OVER THE CWA WILL BE SLIGHTLY COOLER
AFTER THE RIDGE BREAKS DOWN MONDAY NIGHT...HOWEVER THEY WILL REMAIN
ABOVE NORMAL WITH HIGHS GENERALLY IN THE UPPER 60S/LOW 70S ACROSS
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1010 PM MDT THU MAR 22 2012
VFR EXPECTED THROUGH THE PERIOD AT KGLD AND KMCK. VARIABLE WINDS
6 KTS OR LESS EXPECTED THROUGH 00Z BEFORE BECOMING S/SE AROUND
7KTS. MAY SEE SOME FOG AND CIGS 1500-2500 FT AT KGLD EARLY FRIDAY
MORNING GIVEN THE LIGHT WINDS AND RECENT RAINFALL. OTHERWISE...AT
KGLD EXPECTING CLOUDS BETWEEN 5-10K FT AS WRAPAROUND CLOUDINESS ON
THE BACK SIDE OF AN UPPER LEVEL LOW PRESSURE AREA MOVES ACROSS THE
AREA TONIGHT THROUGH FRIDAY MORNING.
&&
.FIRE WEATHER...
ISSUED AT 232 PM MDT THU MAR 22 2012
RH VALUES WILL APPROACH CRITICAL LEVELS EACH AFTERNOON FROM SATURDAY
THROUGH NEXT WEDNESDAY...PRIMARILY OVER WESTERN PARTS OF OUR
FORECAST AREA. THERE ARE STILL QUESTIONS REGARDING WHETHER WINDS
WILL FALL WITHIN RED FLAG CRITERIA EACH AFTERNOON. THE GUSTIEST
WINDS ARE CURRENTLY EXPECTED SUNDAY AND MONDAY. AT THIS TIME THE
THE BEST CHANCE FOR RED FLAG CRITERIA TO BE MET STILL LOOKS TO BE ON
MONDAY AFTERNOON...WITH WITH WIND GUSTS AROUND 30 MPH AND RH VALUES
IN THE 15-20 PERCENT RANGE. ANOTHER FACTOR TO CONSIDER WILL BE THE
EFFECT OF OUR RECENT RAINFALL ON FUELS. AFTER SEVERAL VERY WARM/DRY
AFTERNOONS FUELS WILL LIKELY BE FAVORABLE...ESPECIALLY BY
SUNDAY/MONDAY AFTERNOONS. IT IS STILL TOO EARLY TO ISSUE A
WATCH/WARNING FOR THESE PERIODS...SO THE SITUATION WILL CONTINUE TO
BE MONITORED.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
KS...NONE.
NE...NONE.
&&
$$
UPDATE...007
SHORT TERM...MENTZER
LONG TERM....DR
AVIATION...007
AREA FORECAST DISCUSSION...UPDATED
NWS PADUCAH KY
1231 AM CDT FRI MAR 23 2012
.UPDATE...
ISSUED AT 1158 PM CDT THU MAR 22 2012
MAIN CHALLENGE THIS EVENING AND INTO THE OVERNIGHT HOURS HAS BEEN
THE THE VARIABILITY OF CLOUD COVER BETWEEN THE CONVECTIVE BANDS
ROTATING AROUND THE CLOSED COLD CORE UPPER LOW MOVING INTO
SOUTHWEST MO. THE SHORT TERM NUMERICAL MODEL SUITE /4KM NAM-WRF
ARW AND NMM...AS WELL AS THE 3KM HRRR AND 12KM NAM-WRF/ STILL
SUGGEST THAT MOST OF THE WFO PAH FORECAST AREA WILL REMAIN OUT OF
THE PRECIPITATION...WITH THE EXCEPTION OF SOUTHEAST MO BETWEEN
09-12Z FRIDAY.
WITH THE CLEAR SKIES...FOG WILL BE AN INTERMITTENT PROBLEM
OVERNIGHT. SOME OF THE FOG WILL REMAIN QUITE SHALLOW /GROUND
FOG/...WHILE DEEPER MORE PERSISTENT FOG WILL DEVELOP LATER TONIGHT
ALONG THE EDGE OF THE RECEDING OPAQUE CLOUD COVER. THE GRIDDED
FORECAST HINTS AT THE AREAS WITH THE GREATER POTENTIAL FOR DENSE
FOG...BUT LIGHT FOG AND/OR GROUND FOG WILL BE POSSIBLE ACROSS MOST
AREAS UNDER THE CLEARING SKIES OVERNIGHT. A SPECIAL WEATHER
STATEMENT WAS ISSUED FOR PARTS OF SOUTHEAST MISSOURI AND ALL OF
SOUTHERN ILLINOIS FOR FOG DEVELOPMENT.
AN INITIAL LOOK AT THE FRIDAY CONVECTIVE ACTIVITY SUGGESTS A FAIR
AMOUNT OF MULTICELL DEVELOPMENT WITH THE MAIN ROTATING SHEAR AXES
AHEAD OF THE COLD CORE LOW CIRCULATION. THE NAM-WRF SUGGESTS A
QUICK TURNAROUND IN THE EXPENDITURE OF CAPE...WITH BANDING OF
PRECIPITATION A LIKELY SCENARIO. THE BIG KEY WILL BE THE AMOUNT OF
DESTABILIZATION OF THE BOUNDARY LAYER DURING THE MORNING HOURS.
THIS MAY SLOW THE ONSET OF SIGNIFICANT PARCEL MIXING OVER SOUTHERN
IL/WESTERN KY UNTIL LATER IN THE MORNING /POSSIBLY AFTER 16Z/. BY
THAT TIME...SUFFICIENT SHEAR AND SHARPER LAPSE RATES SHOULD LEAD
TO BETTER UPDRAFTS CAPABLE OF HAIL. I WOULD NOT BE SURPRISED TO
SEE SOME 1-1.5 INCH HAIL IN LOCAL CASES...BUT MOST HAIL SHOULD
REMAIN IN THE 0.25-0.75 INCH SIZE CATEGORY. THE 4KM NAM-WRF /ARW
VERSION/ HINTED THAT SERN IL AN SWRN IN COULD SEE BETTER UPDRAFT
FOR SEVERE CRITERIA WIND/HAIL IN THE 17Z-22Z TIME FRAME. WILL JUST
HAVE TO WAIT AND SEE. AGAIN...THE KEY WILL BE THE DEGREE OF
INSOLATION /SUNSHINE/ AND LACK OF CLOUD COVER TO SUPPORT SURFACE-
BASED PARCEL LIFT.
UPDATE ISSUED AT 710 PM CDT THU MAR 22 2012
MINOR VORTICITY LOBE/CENTER APPEARED TO BE GENERATED OVER
SOUTHWEST KY/EXTREME SOUTHERN IL NEAR KPAH BETWEEN 5-6 PM CDT.
THIS FEATURE...WELL DEPICTED BY THE 3KM HRRR 1KM AGL REFLECTIVITY
SHOULD CONTINUE TO MOVE NORTHEAST THROUGH 10 PM ACROSS SOUTHERN
IL. THERE MAY BE SOME REGENERATION OF PRECIPITATION AS THIS
FEATURE MOVE NEAR THE CONFLUENCE OF THE WABASH/OHIO RIVERS NEAR
SOUTHWEST INDIANA EARLY THIS EVENING. KEPT A MENTION OF
POP/WEATHER IN THIS AREA...BUT MAY NEED TO RE-ADJUST AS THE
BOUNDARY LAYER STABILIZES AND A WEAK LLJ SET UP.
ABUNDANT MOISTURE NEAR THE SURFACE AND A STABILIZING BOUNDARY
LAYER WILL LIKELY LEAD TO SOME FOG GENERATION AFTER MIDNIGHT. AT
THE CURRENT TIME...THE MENTION OF FOG IS WELL COVERED...BUT PLAN
TO SEE WHERE THE GREATEST VISIBILITY RESTRICTIONS WILL BE FOR THE
MID-EVENING UPDATE.
WITH THE UPPER LOW AND SHARPER LAPSE RATES APPROACHING WITH THE
SOUTHWEST MO CONVECTIVE ACTIVITY...KEPT A NARROW BAND OF ISOLATED
TO SCATTERED THUNDERSTORMS MENTIONED OVER THE WESTERN FOUR COUNTIES
OF SOUTHEAST MO THIS EVENING /MAINLY POPLAR BLUFF-GREENVILLE
WESTWARD/.
PLAN TO HAVE A LITTLE MORE DETAILED LOOK AT THUNDERSTORM/HAIL/WIND
POTENTIAL FOR FRIDAY. THE CURRENT SPC OUTLOOK AREA FOR DAY 2 LOOKS
FAIRLY GOOD...WITH THE TIME OF GREATEST CONCERN LIKELY RANGE
BETWEEN 16Z-22Z /11 AM -5 PM CDT/ ALONG AND EAST OF A KPAH-KSAR-
KMVN LINE.
&&
.SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT)
N-S BAND OF SHOWERS SHIFTING SLOWLY TO THE EAST...A LITTLE FASTER
THAN ORIGINALLY EXPECTED...SO FRONTAL BOUNDARY OBVIOUSLY ON THE
MOVE. SOME DEVELOPMENT WEST OF THE MAIN BAND...BUT NOT FILLING IN TOO
WELL AT THE MOMENT.
MAIN BAND OF PRECIP SHOULD CONTINUE ITS EASTWARD MOVEMENT OVERNIGHT...
HOWEVER BY LATE TONIGHT THE LEADING EDGE OF PRECIP ASSOCIATED WITH
THE PARENT UPPER LOW IS EXPECTED TO BE MOVING INTO THE WESTERN
SECTIONS OF OUR CWA. IF SKIES REMAIN CLEAR TO MOSTLY CLEAR OVERNIGHT
BETWEEN THE TWO AREAS OF PRECIP...WITH WET SOIL AND LIGHT TO CALM
WINDS...AREAS OF FOG WILL LIKELY DEVELOP...SO ADDED IT.
THE COMBINATION OF THE PARENT UPPER LOW MOVING ACROSS OUR CWA
FRIDAY...STEEP MID LEVEL LAPSE RATES...AND COLD AIR ALOFT WILL
LIKELY GENERATE THUNDERSTORM DEVELOPMENT...WITH THERE BEING A
THREAT FOR LARGE HAIL PRODUCTION...ESPECIALLY ACROSS THE NORTHERN
HALF OF THE CWA.
FRIDAY NIGHT PRECIP CHANCES WILL DIMINISH FROM WEST TO EAST AS THE
UPPER MOVES FARTHER AWAY FROM OUR CWA.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
SHOWERS WILL LINGER ACROSS THE LOWER OHIO VALLEY ON SATURDAY AS THE
UPPER LOW SLIDES SOUTHEAST ACROSS NORTHEAST PORTIONS OF THE PADUCAH
FORECAST AREA. DUE TO THE PROXIMITY OF THE LOW...THUNDERSTORMS WILL
REMAIN POSSIBLE ACROSS THE EASTERN THIRD OF THE FA...WITH SOME SMALL
HAIL NOT OUT OF THE QUESTION. BY SATURDAY NIGHT...JUST A FEW
SHOWERS WILL BE POSSIBLE ACROSS EASTERN THIRD OF THE FA.
AN UPPER LEVEL RIDGE WILL BUILD ACROSS THE SOUTHERN PLAINS SUNDAY
AND SLIDE EAST INTO EARLY NEXT WEEK. THIS WILL KEEP CONDITIONS DRY
WITH TEMPERATURES 10 TO 15 DEGREES ABOVE NORMAL.
GFS AND ECMWF SHOW A LOW PRESSURE SYSTEM SLIDING FROM THE NORTHERN
PLAINS INTO THE NORTHERN GREAT LAKES REGION LATE TUESDAY INTO
WEDNESDAY. THIS LOW WILL BRING A COLD FRONT INTO THE AREA TUESDAY
NIGHT INTO THURSDAY. BOTH MODELS PRODUCE QPF...THOUGH GFS PRODUCES
MORE SIGNIFICANT QPF TUESDAY NIGHT INTO WEDNESDAY NIGHT...WHILE THE
ECMWF HOLDS OFF ON A LITTLE MORE SUBSTANTIAL QPF UNTIL THURSDAY WHEN
IT BRINGS THE FRONT BACK NORTH. IN EITHER CASE...AT LEAST SOME
CHANCE POPS LOOK REASONABLE ACROSS NORTHERN PORTIONS OF THE FA
TUESDAY NIGHT...AND ACROSS THE ENTIRE FA WEDNESDAY INTO WEDNESDAY
NIGHT. WENT WITH JUST SOME SMALL POPS ACROSS NORTHEAST AND SOUTHERN
PORTIONS ON THURSDAY FOR NOW UNTIL MODELS BECOME MORE DEFINITIVE
WITH TIMING AND FRONTAL PLACEMENT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1158 PM CDT THU MAR 22 2012
MAIN CHALLENGE WITH THE 06Z TAF ISSUANCE HAS BEEN THE ONSET OF
VLIFR TO IFR CEILINGS AND VISIBILITIES ASSOCIATED WITH THE
RECEDING OPAQUE CLOUD COVER. I HAVE ADJUSTED THE KCGI/KPAH TAF
SITES TO ADDRESS PREVAILING HIGHER VISIBILITIES WITH INTERMITTENT
GROUND FOG /MIFG/. FOR THE MAIN CONVECTIVE ACTIVITY ACROSS THE TAF
SITES ON FRIDAY...ADDRESSED THESE INSTANCES WITH VFR CEILINGS AND
VISIBILITIES...AS WELL AS VICINITY THUNDERSTORM CHANCES. GIVEN THE
BANDED NATURE OF THE EXPECTED CONVECTION...IT WILL BE HARD TO TIME
VISIBILITY AND CEILING RESTRICTIONS BEYOND 1-2 HOURS AT A TIME.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...SMITH
SHORT TERM...JP
LONG TERM....RST
AVIATION...SMITH
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
416 AM CDT FRI MAR 23 2012
.DISCUSSION.../ISSUED AT 416 AM CDT/
INITIAL CONCERN IS DENSE FOG WHICH HAS DEVELOPED ACROSS EASTERN
PORTIONS OF THE FORECAST AREA. HRRR HAD A DECENT HANDLE ON THE
DEVELOPMENT AREA THROUGH THE EARLY MORNING AND TRIES TO EXPAND THE
WESTERN EDGE OF THE FOG WESTWARD TO THE JAMES VALLEY THROUGH 13Z
BEFORE RAPID IMPROVEMENT IN VISIBILITY BETWEEN 15Z AND 17Z. NOT YET
SEEING ANY INDICATION OF MUCH WESTWARD PUSH INTO SOMEWHAT DRIER LOW
LEVEL AIR THOUGH...SO WILL LET DENSE FOG ADVISORY ISSUED EARLIER FOR
AREAS ALONG/EAST OF HURON-SALEM-AKRON LINE STAND. FOG EXPECTED TO
LIFT DURING THE LATE MORNING...THOUGH MAY SEE SOME LINGERING STRATUS
IN EASTERN AREAS INTO THE EARLY AFTERNOON. BETWEEN THAT AND MID-UPPER
LEVEL CLOUDS CONTINUING TO WRAP AROUND SLOWLY DEPARTING UPPER LOW...
EASTERN COUNTIES SHOULD BE PARTLY SUNNY THROUGH THE AFTERNOON WITH
MORE SUNSHINE EXPECTED ALONG/WEST OF I-29. LIGHT WIND FLOW TODAY WILL
LIKELY NOT SCOUR OUT RESIDUAL LOW LEVEL MOISTURE IN THE EAST THOUGH
AND COULD SEE SOME REDEVELOPMENT OF FOG LATE TONIGHT/EARLY SATURDAY
AND HAVE ADDED PATCHY FOG TO AREAS ALONG/EAST OF THE BUFFALO RIDGE
AND IOWA GREAT LAKES.
OTHERWISE BUILDING UPPER RIDGE STILL ON TRACK TO BRING DRY WEATHER
FOR THE WEEKEND. GFS/NAM NOW STRONGER THAN THEIR RUNS FROM 24 HOURS
AGO WITH NORTHERN STREAM WAVE TRACKING ACROSS CANADA THIS WEEKEND.
THIS ALLOWS FRONT AND TRAILING RELATIVELY COOLER AIRMASS TO PUSH
FARTHER SOUTH THROUGH THE UPPER MIDWEST...SIMILAR TO WHAT ECMWF/GEM
WERE SHOWING YESTERDAY MORNING. SATURDAY SHOULD BE QUITE MILD OVER
THE ENTIRE CWA WITH HIGHS IN THE 70S...POSSIBLY HITTING 80 IN PARTS
OF THE MISSOURI VALLEY. FRONTAL BOUNDARY THEN SETS UP NORTHWEST TO
SOUTHEAST ACROSS THE CWA...MAKING TEMPERATURES A LITTLE MORE TRICKY
FOR SUNDAY INTO MONDAY. BOUNDARY WILL SEPARATE 50S AND LOWER 60S IN
MINNESOTA...FROM UPPER 70S-LOWER 80S IN NEBRASKA AND SOUTHWEST SOUTH
DAKOTA...AND THE GRADIENT LIKELY TO BE SOMEWHERE IN OUR CWA. FOR NOW
HAVE COOLED NORTHEAST AREAS FROM PREVIOUS FORECAST FOR SUNDAY/MONDAY
BUT GRADIENT MAY HAVE TO BE TIGHTENED FURTHER IF 925MB TEMPS...WHICH
RANGE FROM 7-9C IN SOUTHWEST MN TO THE LOWER 20S IN SOUTH CENTRAL
SD...PAN OUT FOR MONDAY AFTERNOON.
BOUNDARY COULD ALSO BE FOCUS FOR A FEW SHOWERS OR THUNDERSTORMS LATE
SUNDAY NIGHT AND MONDAY AS LOW LEVEL JET INCREASES AHEAD OF THE NEXT
SYSTEM. INSTABILITY ON THE WEAK SIDE ALONG/NORTHEAST OF THE BOUNDARY
WITH MORE FAVORABLE CAPE BUILDING INTO WARM SECTOR ACROSS SOUTHWEST
CWA MONDAY AFTERNOON...THOUGH PRETTY STOUT CAP REMAINS IN PLACE
THROUGH THE AFTERNOON SO KEEPING POPS ON THE LOW SIDE FOR DAYTIME
HOURS. BETTER CHANCE LOOKS TO BE MONDAY NIGHT AS BOTH GFS/ECMWF SHOW
POTENT MID-UPPER LEVEL WAVE CRASHING INTO THE RIDGE OVER THE EASTERN
DAKOTAS. WITH STRONG DYNAMIC LIFT AND VERY STRONG LOW-MID LEVEL WINDS
AROUND SOUTH SIDE OF DEEP LOW...MAY NOT TAKE MUCH TO PRODUCE DAMAGING
WIND GUSTS WITH ANY STORMS THAT DEVELOP/MOVE INTO THE MORE UNSTABLE
AIR ACROSS THE SOUTHWEST CWA MONDAY NIGHT.
QUICK MOVING COMPACT SYSTEM WILL SHIFT EAST OF THE AREA TUESDAY...
THOUGH COULD SEE SOME SHOWERS WRAP AROUND INTO MAINLY NORTHERN PARTS
OF THE AREA TUESDAY BEFORE DRIER AIR BUILDS IN AND PRECIP THREAT
SHIFTS EAST OF THE AREA TUESDAY NIGHT. WITH STRONG SURFACE LOW
PASSING TO OUR NORTH TUESDAY...LIKELY TO SEE STRONG SYNOPTIC SCALE
FLOW DEVELOP IN WELL-MIXED DEEP WESTERLY FLOW BEHIND THE FRONT.
UPPER RIDGING WILL BRING DRY WEATHER BACK TO THE AREA FOR WEDNESDAY
AND WEDNESDAY NIGHT...WITH UPPER TROUGH SET TO MOVE INTO THE NORTHERN
PLAINS LATE IN THE WEEK. DIFFERENCES IN TIMING AMONG THE MODELS SO
WILL HAVE JUST A SLIGHT CHANCE OF THUNDERSTORMS IN THE WESTERN CWA
THURSDAY...WITH BETTER CHANCE HOLDING OFF UNTIL THURSDAY NIGHT OR
FRIDAY...DEPENDING ON EVENTUAL TIMING. TEMPERATURES WILL REMAIN ON
THE MILD SIDE OF NORMAL...THOUGH LATTER PART OF THE FORECAST PERIOD
SHOULD BE COOLER THAN THE NEXT FEW DAYS.
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
FOG HAS BEGUN TO DEVELOP ACROSS NORTHWEST IOWA AND IS EXPECTED TO
BECOME MORE WIDESPREAD OVER THE NEXT FEW HOURS. FOG APPEARS TO BE
DEVELOPING A FEW HOURS FASTER THAN THE HRRR OUTPUT. APPEARS AS
THOUGH CLOUD COVER WILL KEEP FOG POTENTIAL AT BAY FOR A FEW HOURS AT
KHON...BUT FOG IS EXPECTED TO IMPACT KFSD TERMINAL FIRST...THEN
EXPANDING TO KHON AND EVENTUALLY DOWN THE RIVER VALLEY IN NORTHWEST
IOWA. HAVE LOWERED EXPECTED VISIBILITIES IN THE TAFS...BUT HAVE NOT
MENTIONED QUARTER MILE YET EVEN THOUGH IT IS POSSIBLE. OVERNIGHT
CREW WILL HAVE TO WATCH THIS CLOSELY. WITH VERY WEAK WINDS ACROSS
THE AREA...FOG WILL LIKELY STICK AROUND THROUGH THE 15-17 TIME
FRAME...WHEN IT WILL GRADUALLY MIX OUT. THEREAFTER...LIGHT WINDS
AND MOSTLY CLEAR SKIES ARE EXPECTED.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR IAZ001>003-
012>014-020>022.
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ071-072-
080-081-089-090-097-098.
NE...NONE.
SD...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR SDZ038>040-
054>056-061-062-067.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1148 PM CDT THU MAR 22 2012
.UPDATE...FOR 06Z AVIATION DISCUSSION.
&&
.AVIATION...06Z AVIATION DISCUSSION.
UNCERTAINTIES...ACTUAL UPPER LEVEL LOW MOVEMENT/INFLUENCES AND
SHWR/TSTM DEVELOPMENT LENGTH AND COVERAGE. SEVERAL ADMS POSSIBLE
THRU 24/06Z. SOME GENERAL UNCERTAINTY WITH ACTUAL CLOUD COVERAGE
TRENDS...WITH POTENTIAL DRY SLOT DEVELOPMENT LEADING TO MVFR FOG
DEVELOPMENT 23/06Z-23/12Z. SHWRS/TSTMS SHOULD REDEVELOP PER
PROXIMITY OF UPPER LEVEL LOW AND DIURNAL HEATING INFLUENCES BY 23/17Z...
WITH VFR CU CEILINGS PREDOMINATE. PER QUESTIONS OF ACTUAL UPPER
LEVEL LOW PROXIMITY...WILL MENTION ONLY VCTS IN TAFS AFTER 24/00Z.
&&
.PREV DISCUSSION.../ISSUED 1022 PM CDT THU MAR 22 2012/
UPDATE...
CONVECTION ACROSS THE PLATEAU HAS NEARLY MOVED OUT OF THE AREA
LEAVING THE MID STATE VIRTUALLY PRECIP FREE RIGHT NOW.
HOWEVER...LATEST RUC AND NAM SOLUTIONS CONTINUE TO SHOW THAT SOME
LATE NIGHT UPPER LEVEL ENERGY COULD GET CONVECTION GOING ONCE
AGAIN. WILL GO AHEAD AND DROP POPS DOWN TO THE CHC CATEGORY ACROSS
OUR EAST.
PREV DISCUSSION... /ISSUED 651 PM CDT THU MAR 22 2012/
UPDATE...FOR 00Z AVIATION DISCUSSION.
AVIATION...00Z AVIATION DISCUSSION.
UNCERTAINTIES...ACTUAL UPPER LEVEL LOW MOVEMENT/INFLUENCES AND SHWR/TSTM
DEVELOPMENT. SEVERAL ADMS POSSIBLE THRU 23/24Z. SOME GENERAL
UNCERTAINTY WITH ACTUAL CLOUD COVERAGE TRENDS...ALONG WITH MVFR
FOG DEVELOPMENT 23/06Z-23/12Z CKV/BNA. THUS...DIMINISH LIGHT SHWRS
AND ERODE CEILINGS BY 23/03Z CKV/BNA...WITH REDEVELOPING
SHWRS/TSTMS PER DIURNAL INFLUENCES AND APPROACHING UPPER LEVEL LOW
BY 23/24Z...WITH VFR CEILINGS. PER BETTER OVERALL MOISTURE...CSV
MVFR CEILINGS WITH LIGHT SHWRS TRANISTIONING TO TSTMS FROM 23/14Z-23/24Z.
PREV DISCUSSION.../ISSUED 632 PM CDT THU MAR 22 2012/
UPDATE...
SFC BOUNDARY ACROSS WESTERN MIDDLE TN CONTINUES TO DECREASE IN
STRENGTH IN TERMS OF THE FORCING ASSOCIATED WITH IT. ACTIVITY
ACROSS OUR EASTERN ZONES IS IN RESPONSE TO AN UPPER IMPULSE WITHIN
THE SOUTHERLY FLOW ALOFT. REDEVELOPMENT ACROSS WESTERN ZONES IS
STILL EXPECTED AS ADDITIONAL UPPER LEVEL ENERGY IS EXPECTED TO LIFT
NORTHWARD OVERNIGHT. LATEST NAM12 AND RUC SOLUTIONS ARE IN FAVOR OF
REDEVELOPMENT. HOWEVER...ADDITIONAL QPF AMOUNTS ARE NOT
SIGNIFICANT AND LOOK TO BE ONLY AROUND ONE QUARTER INCH OR SO.
FOR TONIGHT...I WILL BE LEANING TOWARD LOWERING THE POPS AS THE
FUTURE CONVECTION IS DEPENDENT UPON REDEVELOPMENT AS OPPOSED TO
MIGRATION.
OTW...LOW TEMPS LOOK TO BE IN GOOD SHAPE. THE LOWER DEW POINTS ARE
WAY BACK TOWARD FAR WESTERN TN. STILL THOUGH...FOR LOW TEMPS WE SHOULD
SEE UPPER 50S WESTERN AREAS BY SUNRISE WITH NEAR 60 ELSEWHERE. A
GENERALLY LIGHT S/SE WIND FLOW SHOULD CONTINUE.
UPDATED GIRDS/ZONES OUT SHORTLY.
PREV DISCUSSION... /ISSUED 339 PM CDT THU MAR 22 2012/
SHORT TERM...BAND OF SHOWERS AND ISOLATED THUNDERSTORMS CONTINUES
TO MOVE SLOWLY EASTWARD ACROSS THE MID STATE THIS AFTERNOON. BY
MID-AFTERNOON, THE BAND WAS CENTERED NEAR THE I-65 CORRIDOR.
AFTERNOON TEMPERATURES WERE MAINLY IN THE 70S WHERE RAIN HAD NOT YET
ARRIVED, BUT WERE IN THE UPPER 50S TO UPPER 60S IN THE RAIN-COOLED
AIR.
MODEL SOLUTIONS ARE STILL QUITE SIMILAR WITH THEIR HANDLING OF
SLOW-MOVING CLOSED UPPER LOW OVER THE NEXT FEW DAYS. THE MAIN
FORECAST DIFFICULTY WILL BE THE EXACT LOCATION OF THE DRY SLOT
ON FRIDAY AND THE RESULTING SHOWER/THUNDERSTORM PATTERN TO THE EAST.
RIGHT NOW IT LOOKS LIKE BAND OF PRECIP WILL CONTINUE SLOGGING
EASTWARD OVERNIGHT, BUT WILL PROBABLY SLOW SOMEWHAT AS IT PUSHES
TOWARD THE PLATEAU LATER TONIGHT.
DEEPEST MOISTURE SHOULD BE OVER EASTERN MIDDLE TENNESSEE FRIDAY,
WHERE DAYTIME INSTABILITY WILL BE GREATEST, ALONG WITH AT LEAST A
SLIGHT CHANCE FOR SEVERE THUNDERSTORMS (ATTENDED BY HAIL AND DAMAGING
STRAIGHT LINE WINDS). MEANWHILE, EXPECT WESTERN AREAS TO DRY OUT
DURING THE DAY.
AS CLOSED UPPER LOW PUSHES TO THE OHIO RIVER ON FRIDAY NIGHT, IT
SHOULD BE ACCOMPANIED BY A CIRCULAR AREA OF CLOUDS SIMILAR TO WHAT
WE`VE OBSERVED OVER THE PLAINS STATES TODAY. AS A RESULT EXPECT CLOUDS,
ALONG WITH A CHANCE OF SHOWERS AND THUNDERSTORMS, TO BE PRESENT
IN A RELATIVELY BROAD SWATH TO THE SOUTH AND EAST OF THE LOW PRESSURE
CENTER.
ON SATURDAY, AS COLD CORE LOW DROPS EAST-SOUTHEASTWARD ACROSS THE
TENNESSEE VALLEY, WE WILL SEE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS IN MIDDLE TENNESSEE. WITH COLDER AIR ALOFT, WOULD
NOT BE SURPRISED TO SEE SOME "HAILERS" ON SATURDAY.
SHOWERS FINALLY PULL EAST OF OUR AREA BY SUNDAY, AND GIVE WAY TO
A SPELL OF DRY WEATHER SUNDAY THROUGH TUESDAY. A RIDGE OF HIGH
PRESSURE BUILDS IN FROM THE WEST, ACCOMPANIED BY A WARMING TREND.
FOLLOWING WEEKEND HIGH TEMPERATURES IN THE UPPER 60S TO LOWER 70S
AT NASHVILLE, HIGHS WILL LIKELY PUSH BACK TO NEAR 80 DEGREES BY
TUESDAY.
LONG TERM...A SHORTWAVE WILL PUSH IN AND DAMPEN OUR FRIENDLY RIDGE
BY THE MIDDLE-TO-LATTER PART OF NEXT WEEK, BRINGING ALONG ANOTHER
CHANCE FOR SHOWERS AND THUNDERSTORMS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1007 AM CDT FRI MAR 23 2012
.DISCUSSION...
ISSUED 1005 AM CDT FRI MAR 23 2012
LARGE STACKED LOW SPINNING OVER THE SOUTHEAST TIP OF KANSAS PER
WATER VAPOR IMAGERY...WITH SURFACE OBS AND RADAR IMAGERY SHOWING A
SECONDARY LOW PRESSURE AREA OVER CENTRAL MISSOURI. HAD QUITE A BIT
OF FOG DEVELOP OVER THE WESTERN 2/3 OF THE CWA EARLIER...BUT
VISIBILITIES WERE RAPIDLY IMPROVING BY 9 AM AND LATEST
OBSERVATIONS SHOWING MOST SITES ABOVE 4 MILES THIS HOUR. HAVE BEEN
SEEING A RAPID INCREASE IN SHOWERS AND STORMS OVER SOUTHEAST
MISSOURI RECENTLY...WITH A FEW SHOWERS/STORMS NOW MOVING INTO FAR
SOUTHERN PARTS OF OUR CWA. 12Z SOUNDING FROM SPRINGFIELD MO SHOWED
500 MB TEMPERATURES OF -26C ASSOCIATED WITH THE UPPER LOW...WHICH
WILL TRACK EASTWARD ACROSS SOUTHERN MISSOURI THIS AFTERNOON. THIS
WILL ENHANCE MID-LEVEL LAPSE RATES...WITH LATEST RUC MODEL SHOWING
RATES OF AROUND 7.5 TO 8C/KM OVER OUR AREA BY EARLY AFTERNOON
SUPPORTING HAIL DEVELOPMENT WITH THE STRONGER STORMS. SEVERE
WEATHER POTENTIAL STILL EXISTS BECAUSE OF THIS...WITH AREAS
SOUTHEAST OF I-55 MOST AT RISK.
UPDATED GRIDS HAVE BEEN SENT...WITH UPDATED ZONES TO FOLLOW AROUND
1015 AM. MOST CHANGES WERE IN THE PRECIP/WEATHER TYPES...WITH SOME
ADJUSTMENTS TO THE HOURLY GRIDS FOR OTHER ELEMENTS.
GEELHART
&&
.AVIATION...
ISSUED 647 AM CDT FRI MAR 23 2012
COMPLEX AVIATION FORECAST THIS PACKAGE. SITES THAT SAW SOME
CLEARING OVERNIGHT HAVE NOW BEEN REDUCED TO LIFR AND
VLIFR...EITHER DUE TO FOG AND/OR THE LOWER CIGS. THESE CONDITIONS
SHOULD CONTINUE FOR A FEW HOURS THIS MORNING. AS THE SUN COMES UP
AND BURNS SOME OF THE LOWER CIGS AND FOG OFF THIS
MORNING...CONDITIONS SHOULD IMPROVE TO MVFR. IN ADDITION...SHOWERS
WILL MOVE BACK INTO THE AREA AT ALL SITES WITH 5SM BR. BELIEVE
ISOLATED THUNDERSTORMS ARE ALSO POSSIBLE SO WILL HAVE VCTS AT ALL
SITES FOR THE AFTERNOON AND EARLY EVENING HOURS. ONCE THE PCPN
ENDS...CONDITIONS SHOULD IMPROVE TO VFR FOR REST OF THE NIGHT AND
OVERNIGHT. PRESSURE GRADIENT IS VERY WEAK SO EXPECT LIGHT WINDS TO
BECOME SOUTHEAST FOR LATER THIS MORNING...THROUGH THIS AFTERNOON
AND THIS EVENING. THEN LIGHT WINDS ARE EXPECTED AGAIN OVERNIGHT.
AUTEN
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT FRI MAR 23 2012
SHORT TERM...TODAY THROUGH MONDAY NIGHT
00Z MODELS REMAIN IN FAIR AGREEMENT THROUGH THIS WEEKEND AND WILL
USE A BLEND. MET AND MAV GUIDANCE TEMPS SIMILAR THROUGH THIS
WEEKEND AND STAYED CLOSE TOO. GUIDANCE CONTINUES TO GO WARMER ON
SUNDAY AND HAS HIGHS IN THE MID 70S MOST AREAS AND TRENDED THE
FORECAST IN THAT DIRECTION.
COOLER TEMPERATURES EXPECTED LATE THIS WEEK THOUGH STILL 10-15
DEGREES ABOVE NORMAL AND SUNDAY NOW LOOKS WARMER IN THE 70S.
UNSETTLED WEATHER PATTERN EXPECTED THROUGH SAT DUE TO 551 DM 500
MB LOW OVER SOUTHEAST KS THAT SLOWLY WEAKENS IT IT MOVES INTO SE
MO BY SUNSET AND THEN INTO SOUTH CENTRAL KY/MID TN BY SUNSET SAT.
SPC HAS MUCH OF CENTRAL/SE IL INTO THE LOWER OHIO VALLEY IN A
SLIGHT RISK THIS AFTERNOON FOR MAINLY LARGE HAIL (15%) RISK WHILE
WINDS AND ISOLATED TORNADOES ARE JUST 5% RISK.
SHOWERS AND ISOLATED THUNDERSTORMS OVER INDIANA AND NE IL DRIFTING
NNW AROUND THE 551 DM 500 MB LOW OVER SE KS. A SMALL BAND OF
SHOWERS AND A FEW THUNDERSTORMS OVER CENTRAL AND SOUTHCENTRAL MO
CLOSER TO THE UPPER LEVEL LOW. DRY WEDGE INBETWEEN OVER CENTRAL
AND SW IL AND SOME CLEARING FROM LINCOLN SW HAS ALLOWED SOME FOG
TO FORM EARLY THIS MORNING...EVEN DENSE FOG AT MACOMB...KEOKUK AND
PITTSFIELD IN WEST CENTRAL IL. VSBYS GENERALLY 3-5 MILES WEST OF
LINCOLN AND MAY NEED TO ADD FOG TO THE FORECAST FOR THESE AREAS
INTO MID MORNING AND VSBYS LIKELY DROP FURTHER.
EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP BY MIDDAY
AND BECOME MORE WIDESPREAD DURING THE AFTERNOON AS UPPER LEVEL LOW
MOVES INTO SOUTHERN MO AND AIRMASS GETS MORE UNSTABLE AND HAVE
LIKELY TO EVEN CATEGORICAL POPS THIS AFTERNOON OVER SW AREAS. PER
SPC DAY1 OUTLOOK...BAND/ARC OF THUNDERSTORMS IS EXPECTED TO
INCREASE IN COVERAGE/INTENSITY FROM MIDDAY THROUGH AT LEAST MID
AFTERNOON...IN ZONE OF CONVERGENCE LOCATED NE-E OF DEEP- LAYER
LOW. COLD CORE CONVECTIVE REGIME FCST TO SHIFT EWD/NEWD ACROSS
OUTLOOK AREA...WITH DOMINANT THREAT BEING LARGE HAIL...ISOLATED
DAMAGING GUSTS POSSIBLE. TORNADO POTENTIAL APPEARS
CONDITIONAL/MARGINAL ON OUTLOOK SCALE ATTM...BUT MAY BE LOCALLY
ENHANCED BY STORM INTERACTIONS WITH BANNERS OF BOUNDARY- LAYER
VORTICITY. ENHANCED/7.5-8.5 DEG C/KM MID LEVEL LAPSE RATES AND MID
50S TO NEAR 60 F SFC DEW POINTS WILL JUXTAPOSE WITH SURFACE
HEATING TO SUPPORT 600-1200 J/KG MLCAPE...AMIDST 30-45 KT
EFFECTIVE SHEAR MAGNITUDES. THUNDERSTORMS SHOULD DIMINISH DURING
EARLY THIS EVENING WITH LOSS OF DAYTIME HEATING.
SHOWERS TO DIMINISH OVERNIGHT AND THEN INCREASE AGAIN BY SAT
AFTERNOON WITH ISOLATED THUNDERSTORMS POSSIBLE OVER EASTERN/SE IL
SAT AFTEROON ESPECIALLY NEAR THE WABASH RIVER WHERE SHOWERS MAY
LINGER EARLY SAT EVENING BY LAWRENCEVILLE. UPPER LEVEL LOW SLOWLY
WEAKENS AS IT DRIFTS ESE INTO EASTERN TN BY MIDNIGHT SAT NIGHT.
NICE WEATHER EXPECTED EARLY NEXT WEEK WITH UPPER LEVEL LOW
PULLING AWAY INTO THE SE STATES AND STRONG UPPER LEVEL RIDGING
OVER THE GREAT PLAINS SHIFTING EASTWARD INTO THE MS VALLEY BY MON
NIGHT AND INTO IL TUE. 850 MB TEMPS WARM UP SUNDAY TO 10C OR
WARMER SW AREAS AND GIVES HIGHS IN THE LOW TO MID 70S. BACKDOOR
COLD FRONT TO MOVE FROM THE GREAT LAKES REGION THROUGH IL EARLY
NEXT WEEK...COOLING TEMPS MONDAY ESPECIALLY NE AREAS BUT DRY
CONDITIONS EXPECTED SUNDAY THROUGH TUE.
LONG TERM...TUESDAY THROUGH FRIDAY
A PROGRESSIVE NORTHERN STREAM WEATHER SYSTEM TRACKING EAST ALONG
THE US/CANADIAN BORDER TO PUSH A COLD FRONT THROUGH IL TUE NIGHT
AND THEN STALL OUT NEAR THE OHIO RIVER WED BEFORE LIFTING BACK
NORTH LATER NEXT WEEK. THIS TO BRING CHANCES OF
SHOWERS/THUNDERSTORMS BY TUE NIGHT AND MAINLY IN SE IL WED AND
THEN HAVE SLIGHT CHANCES OF CONVECTION LATE NEXT WORK WEEK WITH
FRONT LIFTING BACK NORTH. TEMPS OVERALL TO REMAIN ABOVE NORMAL AND
NO FROST OR FREEZE EXPECTED THROUGH NEXT WEEK.
HUETTL
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
717 AM CDT FRI MAR 23 2012
.UPDATE...
SUNRISE HAS ALLOWED VISIBILITIES TO SUDDENLY TANK. WEB CAMS SHOW
THE FOG IS NOT CONTINUOUS WITH AREAS OF GOOD VISIBILITY AND FOG
BANKS IN OTHER AREAS. SO...WILL ISSUE A DENSE FOG ADVISORY AND
WORD IT ACCORDINGLY.
..08..
&&
.PREV DISCUSSION... /ISSUED 653 AM CDT FRI MAR 23 2012/
UPDATE...
MONITORING THE FOG FOR THE PAST FEW HOURS. SFC OBS CONTINUE TO
SUGGEST IT IS PATCHY WITH SOME AREAS HAVING GOOD VISIBILITY. WEB
CAMS THAT HAVE ENOUGH LIGHT OR BACKGROUND LIGHT AVAILABLE SUGGEST
THE FOG IS NOT OVERLY THICK IN VERTICAL DEPTH OR WIDESPREAD. THE
IMPENDING SUNRISE WILL PROVIDE MORE LIGHT OVER THE NEXT 30 MINUTES
TO GIVE MORE CLARITY ON THE WEB CAMS.
BASED ON THIS DATA AND RUC TRENDS IT WOULD APPEAR THAT THE FOG IS
IN LOW LYING AREAS AND SOME RIVER VALLEYS. CURRENT PLAN IS TO
CONTINUE WITH THE SPS UNLESS NEW DATA IN THE NEXT 30 MINUTES
SUGGEST OTHERWISE.
.08..
AVIATION...
VFR TO VLIFR CONDITIONS WILL BE SEEN STARTING AT SUNRISE WITH
CONDITIONS IMPROVING TO MVFR OR VFR BY 18Z/23Z. TRENDS WITH THE
RUC MODEL POINT TO AFTERNOON CONVECTION DEVELOPING WITH POTENTIAL
TSRA IMPACTS AT KMLI/KBRL. KCID/KDBQ MY SEE VCSH. AFT 06Z/24
CONDITIONS ARE EXPECTED TO DETERIORATE TO MINIMALLY MVFR WITH THE
POTENTIAL FOR IFR/LIFR CONDITIONS.
.08..
PREV DISCUSSION... /ISSUED 325 AM CDT FRI MAR 23 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS NUMEROUS WEAK LOWS ACROSS THE MIDWEST ALONG
WITH ASSOCIATED TROFS. A WEAK LOW WAS NORTHEAST OF KDSM WITH A TROF
RUNNING SOUTHEAST TO KEVV. ANOTHER TROF RAN FROM CENTRAL INDIANA
NORTHWEST INTO SOUTHERN MINNESOTA. THE OCCLUDED LOW ASSOCIATED WITH
THE UPPER LOW WAS NEAR KCNU WITH TROFS RADIATING OUT FROM IT. DEW
POINTS WERE GENERALLY IN THE 40S AND 50S ACROSS THE MIDWEST.
RADAR TRENDS SHOW THE MAIN PRECIP GENERALLY NORTH OF A LINE FROM
KRST TO KVYS WHICH WAS ASSOCIATED WITH A VORT MAX ROTATING AROUND
THE UPPER LOW.
SHORT TERM...TODAY AND TONIGHT...
A VERY INTERESTING FCST WITH INTERACTIONS BOTH UP AND DOWN ON
VARIOUS SCALES ALONG WITH NONLINEAR PROCESSES. THE RUC WAS VERY
USEFUL IN ESTABLISHING OVERALL NEAR TERM TRENDS.
THE MCS AND LIFT TOOLS ALONG WITH THE HEAVY RAIN TOOL DO A NICE JOB
OF DEPICTING THE CURRENT PRECIPITATION ACROSS THE AREA. THE PRECIP
IS JUST EAST OF THE MAIN THETA E GRADIENT AND THE RUC HAS THIS
GRADIENT SLOWLY MOVING TO THE NORTH AND EAST THROUGH 12Z. THUS THE
CURRENT PRECIP WILL SLOWLY MOVE OUT OF THE AREA. THE PARTIAL
CLEARING THAT HAS OCCURRED IN THE DIRTY DRY SLOT HAS ALLOWED FOG TO
DEVELOP WITH IT LOCALLY THICK IN AN AREA OF WEAK CONVERGENCE ACROSS
SOUTHEAST IOWA. A FEW GROUND TRUTH REPORTS INDICATE IT IS VERY
SHALLOW. SO WILL CONTINUE TO MONITOR FOR TRENDS BUT WILL HIGHLIGHT
FOG THREAT WITH ANOTHER SPS.
ANY PRECIPITATION SHOULD BE CONFINED TO THE FAR NORTHEAST/EAST PARTS
OF THE CWFA THROUGH MID MORNING BEFORE DIFFERENTIAL HEATING BEGINS
TO PRODUCE SOME ISOLD SHRA ACROSS THE REMAINDER OF THE AREA. LIFT
AND HEAVY RAIN TOOLS SUGGEST A CONSIDERABLE AMOUNT OF NEW CONVECTION
SHOULD BE ACROSS NORTHEAST ILLINOIS AT MID DAY WITH ANOTHER VORT
MAX. LIFT TOOL HAS A THETA E GRADIENT ACROSS ROUGHLY THE SOUTHEAST
HALF OF THE CWFA DURING THE AFTERNOON WITH CONVERGENCE INCREASING.
THUS SHOWERS WITH TSRA WILL BE MOST PREVALENT ACROSS ROUGHLY THE
SOUTHERN HALF OF THE CWFA.
CONVECTION WILL CONTINUE INTO THE EVENING HOURS WITH IT MOST
NUMEROUS ACROSS THE SOUTHERN HALF OF THE CWFA. SUNSET WILL ALLOW THE
ATMOSPHERE TO RE-STABILIZE SO CONVECTION WILL DIMINISH DURING THE
EVENING. MCS AND LIFT TOOLS SUGGEST CONVECTION MAY PERSIST OR EVEN
RE-DEVELOP AFTER MIDNIGHT ACROSS THE NORTHWEST THIRD TO HALF OF THE
CWFA WITH CONVERGENCE INCREASING THERE AS ANOTHER VORT MAX ROTATES
AROUND THE UPPER LOW. ..08..
LONG TERM...SATURDAY THROUGH NEXT THURSDAY...
MOSTLY DRY TO DRY WITH TEMPERATURES STILL ABOVE NORMAL BY AT LEAST
SEVERAL DEGREES IF NOT MORE ALL DAYS....THOUGH NOT RECORD WARMTH.
OVERALL...INITIALIZATION GOOD WITH UPSTREAM ENERGY AND VERIFICATION
AND RUN TO RUN CONTINUITY SUPPORTING A 50/50 BLEND OF GFS/HI-RES
ECMWF. LIMITED SENSIBLE IMPACTS WITH SOME LIGHT TO LOCALLY MODERATE
RAIN AMOUNTS POSSIBLY WITH BACKDOOR COLD FRONT MONDAY INTO TUESDAY
AHEAD OF NEXT SHORT WAVE. PERSISTENCE SUGGEST GUIDANCE TEMPS MAY
STILL BE A FEW DEGREES TOO COOL FOR LATER SHIFTS TO CONSIDER MOST
DAYS EXCEPT MONDAY WHEN BACKDOOR FRONT MAY BE COLDER WITH GOOD
ADVECTION FROM NE WINDS OFF LAKE MICHIGAN.
SATURDAY...KEPT LOW POPS WITH CONVECTIVE TEMPERATURE REACHED FOR
MOSTLY PM POPCORN -SHRA. OTHERWISE...PARTLY SUNNY AND MILD WITH
HIGHS MAINLY 70 TO 75 DEGREES WITH LIGHT WINDS. SATURDAY NIGHT...
CLEARING AND A BIT COLDER WITH MINS AROUND 50 DEGREES BUT LIGHT
WIND SUGGEST LATER SHIFTS MAY NEED TO TRIM AT LEAST A FEW DEGREES
WITH GOOD BL DECOUPLING.
SUNDAY...ANOTHER SPLENDID LATE MARCH DAY AHEAD OF BACKDOOR COLD
FRONT WITH HIGHS WELL INTO THE 70S AND LIGHT NORTH WINDS. SUNDAY
NIGHT...BACKDOOR ARRIVES BY LATE EVENING WITH NE WINDS OF 10-20+
MPH SUGGESTED. WENT WITH MINS OF LOWER 40S NE TO LOWER 50S SW BUT
LATER SHIFTS MAY NEED TO TRIM AT LEAST A COUPLE MORE DEGREES MOST
LOCATIONS. WITH OUR EXTENDED MILD WEATHER...THIS WILL FEEL COLDER
THAN ONE WOULD EXPECT FOR LATE MARCH TO MANY.
MONDAY THROUGH TUESDAY...LOCAL TECHNIQUES SUGGEST NE SECTIONS MAY
STRUGGLE WITH IDEAL FETCH OFF LAKE MICHIGAN IN NE 1/2 OF AREA TO
REACH THE MIDDLE 50S WITH GUSTY NE TO E WINDS OF 15-25+ MPH. LOW
CLOUDS ALSO MAY RESULT IN GREATER IMPACT OF A COOL DAY. NEXT SHORT
WAVE MAY SPAWN LIGHT RAIN AND RAIN SHOWERS MONDAY NIGHT INTO TUESDAY.
THE STRENGTH OF FORCING SHOULD BE BETTER ASCERTAINED NEXT 12-24
HOURS. TUESDAY WARM FRONT SHOULD PASS BY MID DAY FOR TEMPERATURES
BACK INTO THE 70S AND MINS TUESDAY NIGHT UPPER 40S TO LOWER 50S WITH
-SHRA/-TSRA ENDING PROBABLY BY MIDNIGHT WITH PASSAGE OF COLD FRONT.
ANY STORMS ATTM PROBABLY NON-SEVERE DUE TO LIMITED FORCING AND
INSTABILITY.
WEDNESDAY AND THURSDAY...MAINLY DRY WITH WEAK HIGH PRESSURE AND ONLY
A BIT COOLER WITH HIGHS IN THE 60S AND MINS IN THE 40S. THIS IS
STILL 10 PLUS DEGREES ABOVE NORMAL AS OUR REMARKABLE EXTENDED PERIOD
OF MARCH WARM SPELL CONTINUES. ..NICHOLS..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR BENTON-
BUCHANAN-CEDAR-DES MOINES-HENRY IA-IOWA-JEFFERSON-JOHNSON-
KEOKUK-LEE-LINN-LOUISA-MUSCATINE-SCOTT-VAN BUREN-WASHINGTON.
IL...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR HANCOCK-
HENDERSON-HENRY IL-MCDONOUGH-MERCER-ROCK ISLAND-WARREN.
MO...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR CLARK-
SCOTLAND.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
655 AM CDT FRI MAR 23 2012
.SHORT TERM /TODAY/...
BIGGEST FOCUS TODAY WILL BE ON FOG THIS MORNING...AND THEN CHANCES
FOR SHOWERS ACROSS THE SOUTHERN CWA. FOG HAS DEVELOPED ACROSS MUCH
OF THE CWA...MAINLY NORTH AND EAST OF A LINE FROM OTTUMWA...TO DES
MOINES...TO CARROLL. FOG EXPECTED TO PERSIST ACROSS THE AREA INTO
THE MID MORNING HOURS...WITH WINDS EXPECTED TO REMAIN LIGHT AND
CONTINUE TO HAVE MOISTURE NEAR SURFACE CONDITIONS DUE TO RESIDUAL
MOISTURE FROM RAINFALL OVER THE PAST FEW DAYS. MAJORITY OF VSBYS
RANGING FROM NEAR ZERO TO AROUND ONE QUARTER MILE AND ARE ONLY
EXPECTED TO WORSEN THROUGH SUNRISE...WITH THE HRRR KEEPING VSBYS AT
A QUARTER MILE OR BELOW THROUGH 15Z. THEREFORE HAVE OPTED TO ISSUE A
DENSE FOG ADVISORY FOR MUCH OF THE CWA THROUGH 15Z. FOG SHOULD THEN
LIFT INTO SOME LOW STRATUS AND THEN BREAK UP SOME BY LATE MORNING
INTO THE EARLY AFTERNOON HOURS. WITH THE UPPER LOW CHURNING TO THE
SOUTH OF THE CWA...AND CONTINUED CYCLONIC FLOW OVER THE STATE...DO
NOT EXPECT SKIES TO CLEAR COMPLETELY TODAY...WITH SOME SHOWERS
POSSIBLE ACROSS SOUTHERN CWA THROUGHOUT THE DAY AS BANDS OF LIGHT
SHOWERS CONTINUE TO ROTATE NORTHWARD FROM MISSOURI AROUND MAIN LOW
TO THE SOUTH OF THE CWA. ANY PRECIP ROTATING BACK INTO THE AREA
ACROSS NORTHEASTERN CWA APPEARS TO HOLD OFF UNTIL AFTER 00Z. WITH
H85 TEMPERATURES AROUND +9C...A COOLER START TO THE DAY...AND CLOUD
COVER/LINGERING FOG HAVE TEMPS IN THE UPPER 60S TO AROUND 70.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
THOUGH THE UPPER LOW CENTER IS CURRENTLY OVER FAR SOUTHEAST
KANSAS...THE STRONGEST PV ANOMALY ASSOCIATED WITH THE SYSTEM IS
ROUNDING THROUGH CNTRL ARKANSAS. THIS WILL HELP KEEP THE UPPER LOW
ON A MORE SOUTHERLY TRACK BY THIS EVENING AS IT TRACKS INTO THE
LOWER OHIO VALLEY. ONE FINAL PIECE OF ENERGY WILL WRAP AROUND THE
SYSTEM AND INTO EASTERN AS THE SYSTEM DEPARTS TONIGHT. THIS WILL
BRING ONE LAST CHANCE FOR SHOWERS EAST OF INTERSTATE 35. THE AREA
WILL QUICKLY TRANSITION OUT OF CYCLONIC FLOW ON SATURDAY WITH
RIDGING BUILDING IN FROM THE WEST. DESPITE NW FLOW...SOME SFC WARM
ADVECTION WILL BE TAKING PLACE. THE NW FLOW WILL ALSO AID DESCENT
MIXING AND THERE SHOULD BE AN ABUNDANCE OF SUNSHINE CENTRAL AND WEST
WITH A FEW CLOUDS LINGERING OVER THE EAST. A WEAK FRONTAL BOUNDARY
WILL REACH THE NORTHERN THIRD OF THE STATE SATURDAY NIGHT AND SUNDAY
THOUGH THE GREATEST IMPACTS WILL MOVE THROUGH PORTIONS OF MINNESOTA
AND WISCONSIN. SHOULD BE A PLEASANT DAY OVERALL WITH HIGHS IN THE
60S AND 70S WITH LIGHT WINDS.
THE MONDAY FORECAST CONTINUES TO BECOME MORE COMPLEX. THE
AFOREMENTIONED COLD ADVECTION THROUGH WISCONSIN SUNDAY WILL SHIFT
WEST AS A BACK DOOR COLD FRONT OFF LAKE MICHIGAN SUNDAY NIGHT AND
MONDAY. WARM ADVECTION WILL BE LIFTING INTO WESTERN IOWA BY MONDAY
MORNING HOWEVER ITS EASTWARD ADVANCE WILL LIKELY BE OVERCOME BY THE
COOLER AND MORE DENSE AIR FILTERING IN FROM THE EAST. HIGH
TEMPERATURES AT THIS POINT COULD BE TOO HIGH BY SEVERAL DEGREES IF
THE THIS BOUNDARY COMES IN AS STRONG AS SUGGESTED. DESPITE
THIS...MID LEVEL WARM ADVECTION WILL CONTINUE TO OVERSPREAD THE AREA
MONDAY WITH SOME INSTABILITY DEVELOPING AHEAD OF THE LOW LEVEL JET
AND STRONG THETA E ADVECTION. BEST POTENTIAL FOR THUNDERSTORMS WOULD
BE OVER THE NORTH. ANY THUNDER AT THIS TIME LIKELY WILL BE ELEVATED
THOUGH A MARGINAL SEVERE STORM WOULD BE POSSIBLE. BOWLING BALL UPPER
LOW LIFTING INTO THE NORTHERN PLAINS ON TUESDAY COULD PRODUCE SOME
INTERESTING WEATHER TUESDAY PENDING EXACT TIMING AND PLACEMENT OF
THE SYSTEM. COOLER AIR WILL SINK IN BEHIND THE SYSTEM THOUGH AGAIN
THE GREATEST IMPACT WILL BE TO THE NORTHEAST. TEMPERATURES WILL
REMAIN WELL ABOVE SEASONAL VALUES WITH LOW POTENTIAL FOR
PRECIPITATION WEDNESDAY AND THURSDAY.
&&
.AVIATION...23/12Z
LIFR VSBYS/CIGS TO LIFT BY MID MORNING ACROSS KFOD...KALO...AND
KOTM. OTHERWISE MAINLY VFR CONDITIONS EXPECTED WITH A MID LEVEL
CLOUD DECK EXPECTED THROUGH THE PERIOD. FOG DEVELOPMENT POSSIBLE AT
KALO AND KMCW LATE TONIGHT. WINDS TO BE OUT OF THE NORTH TO
NORTHWEST AND LIGHT.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR BLACK HAWK-
BOONE-BREMER-BUTLER-CALHOUN-CARROLL-CERRO GORDO-EMMET-FRANKLIN-
GREENE-GRUNDY-HAMILTON-HANCOCK-HARDIN-HUMBOLDT-JASPER-KOSSUTH-
MARSHALL-PALO ALTO-POCAHONTAS-POWESHIEK-SAC-STORY-TAMA-WEBSTER-
WINNEBAGO-WORTH-WRIGHT.
&&
$$
SHORT TERM...BEERENDS
LONG TERM...DONAVON
AVIATION...BEERENDS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
653 AM CDT FRI MAR 23 2012
.UPDATE...
MONITORING THE FOG FOR THE PAST FEW HOURS. SFC OBS CONTINUE TO
SUGGEST IT IS PATCHY WITH SOME AREAS HAVING GOOD VISIBILITY. WEB
CAMS THAT HAVE ENOUGH LIGHT OR BACKGROUND LIGHT AVAILABLE SUGGEST
THE FOG IS NOT OVERLY THICK IN VERTICAL DEPTH OR WIDESPREAD. THE
IMPENDING SUNRISE WILL PROVIDE MORE LIGHT OVER THE NEXT 30 MINUTES
TO GIVE MORE CLARITY ON THE WEB CAMS.
BASED ON THIS DATA AND RUC TRENDS IT WOULD APPEAR THAT THE FOG IS
IN LOW LYING AREAS AND SOME RIVER VALLEYS. CURRENT PLAN IS TO
CONTINUE WITH THE SPS UNLESS NEW DATA IN THE NEXT 30 MINUTES
SUGGEST OTHERWISE.
..08..
&&
.AVIATION...
VFR TO VLIFR CONDITIONS WILL BE SEEN STARTING AT SUNRISE WITH
CONDITIONS IMPROVING TO MVFR OR VFR BY 18Z/23Z. TRENDS WITH THE
RUC MODEL POINT TO AFTERNOON CONVECTION DEVELOPING WITH POTENTIAL
TSRA IMPACTS AT KMLI/KBRL. KCID/KDBQ MY SEE VCSH. AFT 06Z/24
CONDITIONS ARE EXPECTED TO DETERIORATE TO MINIMALLY MVFR WITH THE
POTENTIAL FOR IFR/LIFR CONDITIONS.
..08..
&&
.PREV DISCUSSION... /ISSUED 325 AM CDT FRI MAR 23 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS NUMEROUS WEAK LOWS ACROSS THE MIDWEST ALONG
WITH ASSOCIATED TROFS. A WEAK LOW WAS NORTHEAST OF KDSM WITH A TROF
RUNNING SOUTHEAST TO KEVV. ANOTHER TROF RAN FROM CENTRAL INDIANA
NORTHWEST INTO SOUTHERN MINNESOTA. THE OCCLUDED LOW ASSOCIATED WITH
THE UPPER LOW WAS NEAR KCNU WITH TROFS RADIATING OUT FROM IT. DEW
POINTS WERE GENERALLY IN THE 40S AND 50S ACROSS THE MIDWEST.
RADAR TRENDS SHOW THE MAIN PRECIP GENERALLY NORTH OF A LINE FROM
KRST TO KVYS WHICH WAS ASSOCIATED WITH A VORT MAX ROTATING AROUND
THE UPPER LOW.
SHORT TERM...TODAY AND TONIGHT...
A VERY INTERESTING FCST WITH INTERACTIONS BOTH UP AND DOWN ON
VARIOUS SCALES ALONG WITH NONLINEAR PROCESSES. THE RUC WAS VERY
USEFUL IN ESTABLISHING OVERALL NEAR TERM TRENDS.
THE MCS AND LIFT TOOLS ALONG WITH THE HEAVY RAIN TOOL DO A NICE JOB
OF DEPICTING THE CURRENT PRECIPITATION ACROSS THE AREA. THE PRECIP
IS JUST EAST OF THE MAIN THETA E GRADIENT AND THE RUC HAS THIS
GRADIENT SLOWLY MOVING TO THE NORTH AND EAST THROUGH 12Z. THUS THE
CURRENT PRECIP WILL SLOWLY MOVE OUT OF THE AREA. THE PARTIAL
CLEARING THAT HAS OCCURRED IN THE DIRTY DRY SLOT HAS ALLOWED FOG TO
DEVELOP WITH IT LOCALLY THICK IN AN AREA OF WEAK CONVERGENCE ACROSS
SOUTHEAST IOWA. A FEW GROUND TRUTH REPORTS INDICATE IT IS VERY
SHALLOW. SO WILL CONTINUE TO MONITOR FOR TRENDS BUT WILL HIGHLIGHT
FOG THREAT WITH ANOTHER SPS.
ANY PRECIPITATION SHOULD BE CONFINED TO THE FAR NORTHEAST/EAST PARTS
OF THE CWFA THROUGH MID MORNING BEFORE DIFFERENTIAL HEATING BEGINS
TO PRODUCE SOME ISOLD SHRA ACROSS THE REMAINDER OF THE AREA. LIFT
AND HEAVY RAIN TOOLS SUGGEST A CONSIDERABLE AMOUNT OF NEW CONVECTION
SHOULD BE ACROSS NORTHEAST ILLINOIS AT MID DAY WITH ANOTHER VORT
MAX. LIFT TOOL HAS A THETA E GRADIENT ACROSS ROUGHLY THE SOUTHEAST
HALF OF THE CWFA DURING THE AFTERNOON WITH CONVERGENCE INCREASING.
THUS SHOWERS WITH TSRA WILL BE MOST PREVALENT ACROSS ROUGHLY THE
SOUTHERN HALF OF THE CWFA.
CONVECTION WILL CONTINUE INTO THE EVENING HOURS WITH IT MOST
NUMEROUS ACROSS THE SOUTHERN HALF OF THE CWFA. SUNSET WILL ALLOW THE
ATMOSPHERE TO RE-STABILIZE SO CONVECTION WILL DIMINISH DURING THE
EVENING. MCS AND LIFT TOOLS SUGGEST CONVECTION MAY PERSIST OR EVEN
RE-DEVELOP AFTER MIDNIGHT ACROSS THE NORTHWEST THIRD TO HALF OF THE
CWFA WITH CONVERGENCE INCREASING THERE AS ANOTHER VORT MAX ROTATES
AROUND THE UPPER LOW. ..08..
LONG TERM...SATURDAY THROUGH NEXT THURSDAY...
MOSTLY DRY TO DRY WITH TEMPERATURES STILL ABOVE NORMAL BY AT LEAST
SEVERAL DEGREES IF NOT MORE ALL DAYS....THOUGH NOT RECORD WARMTH.
OVERALL...INITIALIZATION GOOD WITH UPSTREAM ENERGY AND VERIFICATION
AND RUN TO RUN CONTINUITY SUPPORTING A 50/50 BLEND OF GFS/HI-RES
ECMWF. LIMITED SENSIBLE IMPACTS WITH SOME LIGHT TO LOCALLY MODERATE
RAIN AMOUNTS POSSIBLY WITH BACKDOOR COLD FRONT MONDAY INTO TUESDAY
AHEAD OF NEXT SHORT WAVE. PERSISTENCE SUGGEST GUIDANCE TEMPS MAY
STILL BE A FEW DEGREES TOO COOL FOR LATER SHIFTS TO CONSIDER MOST
DAYS EXCEPT MONDAY WHEN BACKDOOR FRONT MAY BE COLDER WITH GOOD
ADVECTION FROM NE WINDS OFF LAKE MICHIGAN.
SATURDAY...KEPT LOW POPS WITH CONVECTIVE TEMPERATURE REACHED FOR
MOSTLY PM POPCORN -SHRA. OTHERWISE...PARTLY SUNNY AND MILD WITH
HIGHS MAINLY 70 TO 75 DEGREES WITH LIGHT WINDS. SATURDAY NIGHT...
CLEARING AND A BIT COLDER WITH MINS AROUND 50 DEGREES BUT LIGHT
WIND SUGGEST LATER SHIFTS MAY NEED TO TRIM AT LEAST A FEW DEGREES
WITH GOOD BL DECOUPLING.
SUNDAY...ANOTHER SPLENDID LATE MARCH DAY AHEAD OF BACKDOOR COLD
FRONT WITH HIGHS WELL INTO THE 70S AND LIGHT NORTH WINDS. SUNDAY
NIGHT...BACKDOOR ARRIVES BY LATE EVENING WITH NE WINDS OF 10-20+
MPH SUGGESTED. WENT WITH MINS OF LOWER 40S NE TO LOWER 50S SW BUT
LATER SHIFTS MAY NEED TO TRIM AT LEAST A COUPLE MORE DEGREES MOST
LOCATIONS. WITH OUR EXTENDED MILD WEATHER...THIS WILL FEEL COLDER
THAN ONE WOULD EXPECT FOR LATE MARCH TO MANY.
MONDAY THROUGH TUESDAY...LOCAL TECHNIQUES SUGGEST NE SECTIONS MAY
STRUGGLE WITH IDEAL FETCH OFF LAKE MICHIGAN IN NE 1/2 OF AREA TO
REACH THE MIDDLE 50S WITH GUSTY NE TO E WINDS OF 15-25+ MPH. LOW
CLOUDS ALSO MAY RESULT IN GREATER IMPACT OF A COOL DAY. NEXT SHORT
WAVE MAY SPAWN LIGHT RAIN AND RAIN SHOWERS MONDAY NIGHT INTO TUESDAY.
THE STRENGTH OF FORCING SHOULD BE BETTER ASCERTAINED NEXT 12-24
HOURS. TUESDAY WARM FRONT SHOULD PASS BY MID DAY FOR TEMPERATURES
BACK INTO THE 70S AND MINS TUESDAY NIGHT UPPER 40S TO LOWER 50S WITH
-SHRA/-TSRA ENDING PROBABLY BY MIDNIGHT WITH PASSAGE OF COLD FRONT.
ANY STORMS ATTM PROBABLY NON-SEVERE DUE TO LIMITED FORCING AND
INSTABILITY.
WEDNESDAY AND THURSDAY...MAINLY DRY WITH WEAK HIGH PRESSURE AND ONLY
A BIT COOLER WITH HIGHS IN THE 60S AND MINS IN THE 40S. THIS IS
STILL 10 PLUS DEGREES ABOVE NORMAL AS OUR REMARKABLE EXTENDED PERIOD
OF MARCH WARM SPELL CONTINUES. ..NICHOLS..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
526 AM MDT FRI MAR 23 2012
.UPDATE...
ISSUED AT 407 AM MDT FRI MAR 23 2012
SHALLOW FOG HAS PRODUCED VISIBILITIES OF 1 TO 5 MILES...WITH LOWER
VISIBILITIES IN THE VALLEYS AND RIVER BOTTOMS AS OVERHEAD CLOUDS
HAVE DISSIPATED. FOGGY CONDITIONS SHOULD START TO IMPROVE AFTER
6AM MDT/ 7AM CDT AS TEMPERATURES BEGIN TO WARM...WITH THE FOG
COMPLETELY DISSIPATED BY MID MORNING.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 319 AM MDT FRI MAR 23 2012
SOME PATCHY FOG WILL BE POSSIBLE ACROSS THE AREA THIS MORNING DUE TO
THE MOIST GROUND CONDITIONS FROM YESTERDAY/S RAINFALL. THE FOG
SHOULD DISSIPATE BY MID MORNING.
THE CLOSED UPPER LEVEL LOW THAT BROUGHT RAIN TO THE REGION YESTERDAY
WILL CONTINUE TO MOVE EAST TODAY. AN UPPER LEVEL RIDGE WILL MOVE
INTO THE AREA BEHIND THE CLOSED LOW TODAY. AS A RESULT WINDS WILL
BE LIGHT. AS THE CLOSED LOW MOVES EAST...WARMER AIR WILL MOVE IN
FROM THE WEST. WITH 850MB TEMPS AROUND 15C...TEMPS AROUND 70 WILL
BE POSSIBLE. TONIGHT LOWS WILL DIP TO THE UPPER 30S TO AROUND 40.
RELATIVE HUMIDITIES WILL BE NEAR 100 PERCENT OVERNIGHT...HOWEVER
WILL HOLD OFF PLACING FOG IN THE FORECAST AS POINT SOUNDINGS SHOW A
VERY SHALLOW SATURATED LAYER AT THE SURFACE.
SATURDAY THE UPPER LEVEL RIDGE WILL CONTINUE TO MOVE OVER THE AREA.
AT THE SURFACE A TROUGH OF LOW PRESSURE WILL MOVE IN FROM THE WEST
DURING THE MORNING THEN MOVE NORTH DURING THE AFTERNOON AS A WARM
FRONT. 850MB TEMPS OF 20C WILL MOVE OVER THE AREA BEHIND THE
FRONT...ALLOWING HIGHS TO WARM TO NEAR 80 DEGREES DURING THE AFTERNOON.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 319 AM MDT FRI MAR 23 2012
SATURDAY NIGHT LOWS WILL DIP INTO THE MID TO UPPER 40S. PATCHY FOG
WILL BE POSSIBLE GENERALLY ALONG AND EAST OF THE COLORADO BORDER
THROUGH MID MORNING SUNDAY.
SUNDAY SOUTH WINDS WILL INCREASE AS THE SURFACE PRESSURE GRADIENT
TIGHTENS AND THE 850MB WINDS STRENGTHEN. WIND GUSTS OF 35 MPH WILL BE
POSSIBLE DURING THE AFTERNOON. DURING THE AFTERNOON CAPE VALUES OF
500-1500J/KG WILL DEVELOP OVER NORTHWEST KANSAS AND SOUTHWEST
NEBRASKA AS DEW POINTS MOISTEN INTO THE 50S. WILL HOLD OFF PLACING
THUNDERSTORMS IN THE FORECAST AS POINT SOUNDINGS SHOW LARGE DEW
POINT DEPRESSIONS THROUGH THE COLUMN. THE GUSTY SOUTH WINDS AND
850MB TEMPS OF 20C WILL HELP TEMPERATURES TO WARM INTO THE UPPER 70S
AND LOWER 80S.
MONDAY-THURSDAY...MEDIUM RANGE MODELS REMAIN IN REASONABLE AGREEMENT
WITH RESPECT TO LARGE SCALE PATTERN WITH SOME ACTIVE WEATHER
POSSIBLE ON MONDAY AS STRONG SHORT WAVE TROUGH LIFTS ACROSS THE
NORTHERN PLAINS...FORCING COLD FRONT ACROSS THE CWA. LATEST
OPERATIONAL GUIDANCE AND ENSEMBLE DATA CONTINUE TO SUPPORT AT LEAST
A SMALL THREAT FOR THUNDERSTORMS ACROSS EASTERN CWA AND DO NOT SEE
MUCH OF A REASON TO DEVIATE FROM THAT. AFTER THIS INITIAL
SYSTEM...SOMEWHAT AMPLIFIED YET PROGRESSIVE FLOW ALOFT IS EXPECTED
THROUGH THE END OF THE PERIOD WITH SOME WEAK TROUGHING EXPECTED BY
THURSDAY. OVERALL...WOULD NOT BE SURPRISED TO SEE SOME SCATTERED
SHOWERS AND THUNDERSTORMS IN A FEW OF THE PERIODS...BUT OVERALL
THINK PROBABILITIES TO LOW TO REALLY TRY TO PIN DOWN GIVEN OVERALL
WEAK EXPECTED FORCING.
THINK BIGGEST CONCERN OF THE EXTENDED PERIOD WILL BE MONDAY...WITH
POSITION OF UPPER TROUGH LOOKS LIKE STRONG JET OF LOW LEVEL WINDS
WILL DEVELOP ACROSS MUCH OF THE AREA WITH H7 FLOW INCREASING TO 45
TO 50 KTS. IN ADDITION TO THE STRONG WINDS...TEMPERATURES WELL INTO
THE 80S AND MUCH DRIER AIR MOVING INTO THE AREA BEHIND A DRYLINE
WILL ONCE AGAIN INCREASE THE FIRE DANGER TO POTENTIALLY CRITICAL
LEVELS. WILL NEED TO SEE WHAT IMPACT THE WIDESPREAD RAIN HAD ON
FUELS...BUT WILL HAVE TO WATCH THIS PERIOD CLOSELY THE NEXT SEVERAL
DAYS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 517 AM MDT FRI MAR 23 2012
IFR TO VFR CONDITIONS WILL BE POSSIBLE FOR THE TAFS. LATEST
OBSERVATIONS REPORT SHALLOW FOG AT KGLD...WITH VIS VARYING FROM 1SM
TO 10SM. SATELLITE IMAGERY SHOWS A DECK OF LOW CLOUDS MOVING SOUTH
TOWARD KGLD. LATEST REPORT FROM ST. FRANCIS HAS CEILINGS OF
3500FT...SO CEILINGS SHOULD REMAIN ABOVE MVFR. FOR KMCK VIS HAVE
BEEN SLOWLY FALLING OVER THE LAST HOUR OR SO. RUC AND NAM POINT
SOUNDINGS SHOW A SHALLOW SATURATED LAYER AT THE SURFACE. THIS MAY
CAUSE THE VIS TO VARY SO HAVE PLACED A TEMPO GROUP FOR VFR VIS AND
A PREVAILING MVFR VIS. CONDITIONS SHOULD IMPROVE AROUND 15Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
KS...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...JTL
LONG TERM....JRM
AVIATION...JTL
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
859 AM CDT FRI MAR 23 2012
.UPDATE...ISSUED DFA AS LATEST SFC OBS/WEBCAMS SHOW EXTENSIVE
AREA OF DENSE FOG ACROSS NSHORE...TWIN PORTS...SOUTH
SHORE...BRAINERD LAKES/CASS LAKE VICINITY. RUC13 SNDGS SUPPORT
CONTINUATION OF MOIST INVERSION PROFILE THROUGH AT LEAST
MIDDAY...IF NOT LONGER. GIVEN THE DIFFICULT NATURE OF FORECASTING
THIS PARTICULAR ELEMENT...WILL NEED TO MONITOR THROUGH NEXT FEW
HRS FOR UPDATES TO AREAL COVERAGE/TIMING.
&&
.PREV DISCUSSION... /ISSUED 638 AM CDT FRI MAR 23 2012/
AVIATION...12Z TAF ISSUANCE...
WIDESPREAD LIFR/IFR CONDITIONS ARE LIKELY THROUGH LATE THIS
MORNING ACROSS THE REGION DUE TO VERY LOW CIGS AND FG/BR/-RA.
CONDITIONS ARE PROJECTED TO IMPROVE LATE THIS MORNING AND THIS
AFTERNOON TO MORE IFR/MVFR CONDITIONS...BUT BE PREPARED FOR SOME
AREAS TO HAVE LINGERING LIFR CONDITIONS. CONDITIONS SHOULD THEN
WORSEN AGAIN TONIGHT TO LIFR/IFR CONDITIONS DUE TO VERY LOW CIGS
AND FG.
PREV DISCUSSION... /ISSUED 335 AM CDT FRI MAR 23 2012/
SHORT TERM....TODAY THROUGH SATURDAY.
CURRENT RADAR IMAGERY AND SFC ANALYSIS SHOWS WEAK EAST/SOUTHEAST FLOW
WITH SCT RAIN SHOWERS OVER THE CWA. A CORRIDOR OF MODERATE TO
HEAVY RAIN IS FOUND ALONG THE INTERNATIONAL BORDER NEAR THE
OCCLUDED FRONT THAT HAS NOW PUSHED NORTH INTO CANADA. RADAR
ESTIMATED RAINFALL OVER THE PAST 48 HRS RANGES FROM A QUARTER OF
AN INCH IN MOST AREAS...TO HIGHER AMOUNTS OF A HALF TO ONE INCH IN
THE IRON RANGE/ARROWHEAD REGION. AT 300 AM...THE HEAVIEST AMOUNTS
WERE ACROSS NORTHERN ST LOUIS/LAKE COUNTIES WHERE RADAR ESTIMATED
VALUES WERE AROUND AN INCH AND A HALF.
A WELL DEFINED CUT OFF LOW IS CURRENTLY SEEN ON SAT IMAGERY ROTATING
OVER THE CENTRAL PLAINS...CONTINUING TO WRAP WARM HUMID AIR FROM THE
GULF NORTH INTO THE WESTERN GREAT LAKES REGION. WINDS WILL REMAIN
NORTHEAST OVER LAKE SUPERIOR TODAY RESULTING IN COOLER TEMPERATURES
AROUND 45-50 DEGREES LAKESIDE. ELSEWHERE...ANOTHER MILD MARCH DAY
IN THE 60S WITH RAIN SHOWERS/DRIZZLE WILL PREVAIL.
THE LOW WILL GRADUALLY PUSH EAST INTO THE SRN INDIANA/KENTUCKY
REGION THROUGH SATURDAY...ALLOWING FOR UPPER LEVEL RIDING TO BUILD
INTO THE NRN PLAINS. SHORT RANGE MODELS IN AGREEMENT CLOUDS AND
HIGH HUMIDITIES LINGER OVER THE NORTHLAND THROUGH SATURDAY
MORNING...GRADUALLY ERODING IN THE WRN ZONES SAT AFTN. HAVE
INTRODUCED FOG AND DRIZZLE TO ERN HALF OF CWA OVERNIGHT WHERE
SFC-H85 PROFILES REMAIN SATURATED BUT LACK FORCING FOR
SHOWERS/MEASURABLE RAINFALL.
LONG TERM [SATURDAY NIGHT - THURSDAY]...
THE MODELS ARE IN FAIRLY GOOD AGREEMENT...SO LEANED ON A BLEND. THE
MODEL CONSENSUS IS FOR A PASSING COLD FRONT SATURDAY
NIGHT...BRINGING THE NORTHLAND AND MUCH COOLER AND DRIER SUNDAY.
HIGH PRESSURE SHOULD KEEP MOST OF THE REGION DRY MONDAY...BUT HAD TO
INCLUDE SOME LOW POPS FOR SHOWERS AND THUNDERSTORMS ACROSS THE
WESTERN AND SOUTHERN FA DUE TO THE MODELS INDICATING PCPN IN THE
PLAINS FROM ORGANIZING LOW PRESSURE. THAT LOW PRESSURE SYSTEM SHOULD
THEN MOVE ACROSS THE DAKOTAS INTO CENTRAL/NORTHERN MINNESOTA THROUGH
TUESDAY....AND THEN OVER THE GREAT LAKES THROUGH WEDNESDAY. THE
PASSAGE OF THE SYSTEM COULD BRING SHOWERS AND STORMS TO THE
NORTHLAND. HIGH PRESSURE SHOULD THEN PROVIDE DRY WEATHER THURSDAY.
TEMPERATURES WILL GENERALLY REMAIN ABOVE NORMAL THROUGH THE LONG
TERM PERIOD.
&&
.POINT TEMPS/POPS...
DLH 54 42 61 38 / 50 10 10 10
INL 60 46 63 31 / 80 10 20 10
BRD 66 47 69 38 / 40 10 10 10
HYR 64 47 68 42 / 60 10 10 10
ASX 51 42 59 39 / 60 10 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR MNZ020-021-
025-026-033>037.
WI...DENSE FOG ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR WIZ001>003.
LS...NONE.
&&
$$
SHORT TERM...CANNON
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
955 AM EDT FRI MAR 23 2012
.SYNOPSIS...
A SLOW MOVING UPPER LEVEL LOW PRESSURE SYSTEM WILL PUSH INTO THE
REGION BY SATURDAY. THIS LOW WILL THEN SLIDE OFF TO THE SOUTHEAST
SUNDAY WITH HIGH PRESSURE BUILDING BACK IN EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LEVEL LOW IS EVIDENT ON WATER VAPOR IMAGERY SPINNING ACROSS
SOUTHEAST MISSOURI THIS MORNING. AS THE LOW PUSHES SLOWLY EAST
THROUGH THE DAY...BANDS OF SHOWERS ROTATING UP THROUGH THE MID
OHIO VALLEY WILL ALSO SLOWLY WORK THEIR WAY EAST ACROSS MUCH OF
OUR AREA. THE EASTWARD PROGRESSION HAS BEEN RATHER SLOW THOUGH AND
THE LATEST RUC SEEMS TO BE PICKING UP ON THIS. WILL THEREFORE KEEP
HIGHEST POPS MAINLY ACROSS OUR WEST THROUGH A GOOD PART OF THE
DAY. LIGHTNING HAS BEEN FAIRLY SPOTTY SO FAR AND THINK CLOUDS WILL
HELP KEEP INSTABILITY SOMEWHAT MARGINAL...SO EXPECT MAINLY SHOWERS
WITH JUST A CHANCE OF THUNDER. CLOUDS AND PCPN SHOULD HELP KEEP
TEMPS FROM GETTING TOO OUT OF HAND WITH TEMPERATURES GENERALLY IN
THE UPPER 60S TO NEAR 70. OUR FAR NORTHEAST SHOULD SEE A LITTLE
MORE SUN THIS MORNING AND THIS MAY ALLOW THEM TO GET A BIT WARMER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
UPR LVL CLOSED LOW WILL CONTINUE TO SLOWLY INCH ITS WAY EAST
OVERNIGHT. COLD FRONT AHEAD OF THIS FEATURE WILL OCCLUDE AND WILL
MOVE ENE THROUGH THE AREA. BEST CHANCES FOR PCPN WILL BE ACRS
THE ERN ZONES EARLY ON. SOME OF THE MESOSCALE MODELS INDICATE THAT
LIKELY POPS MAY OCCUR ACRS THE SWRN SECTIONS THIS EVENING/OVERNIGHT AS
OCCLUDED FRONT PUSHES THROUGH. HAVE DECIDED TO LEAVE HIGH CHANCE
IN THIS AREA ATTM GIVEN LOW CONFIDENCE. HAVE USED A BLEND OF RAW
MODEL DATA TO COME UP WITH OVERNIGHT LOWS...WHICH SHOULD RANGE
FROM THE LOWER 50S SW TO THE UPPER 50S NE.
FOR SATURDAY INTO SATURDAY NIGHT...UPR LVL CLOSED LOW IS FORECAST
TO PIVOT ESE THROUGH THE OHIO VALLEY. ATTM...A WEAK SFC TROF AND
SFC LOW WILL TREK ACRS THE REGION. LOW LEVEL FORCING WILL BE WEAK
AT BEST...BUT MODELS INDICATE THAT A ROTATING VORT LOBE MAY
PROVIDE THE BEST UPR LVL SUPPORT ACRS THE SWRN ZONES. THUS...HAVE
GONE WITH CHANCE POPS EXCEPT ACRS THE SWRN ZONES WHERE LIKELY POPS
WILL BE USED. BEST CHANCE OF THUNDER WILL OCCUR DURING THE HEAT OF
THE DAY WHEN LOW LEVEL LAPSE RATES WILL BE THE GREATEST. PCPN
SHOULD DECREASE SATURDAY EVENING AS UPR LVL PULLS AWAY AND
INSTABILITY DROPS OFF. TEMPERATURES...ALTHOUGH COOLER...WILL STILL
BE ABOVE NORMAL DESPITE THE UPR LVL CLOSED LOW. HIGHS WILL RANGE
FROM THE MID TO UPPER 60S. LOWS WILL DROP INTO THE UPPER 40S TO
THE LOWER 50S.
FOR SUNDAY INTO SUNDAY NIGHT...ECMWF AND GFS DEPICT A DIGGING MID
LVL TROF WHICH WILL PUSH INTO SE CANADA/NRN NEW ENGLAND BY MONDAY
MORNING. THIS SYSTEM WILL PUSH A COLD FRONT SOUTH THROUGH THE
REGION SUNDAY/SUNDAY EVENING. WILL HOLD ON TO LOW CHANCES POPS
WITH FRONTAL PASSAGE. DRIER AIR AND CLEARING SKIES LATE SUNDAY
NIGHT WILL MARK THE BEGINNING OF A COOLING TREND.
FOR MONDAY INTO MONDAY NIGHT...CANADIAN HIGH PRESSURE WILL BUILD
SOUTHWARD INTO THE GREAT LAKES AND OHIO VALLEY. CAA WILL BRING
TEMPERATURES DOWN CLOSER TO NORMALS FOR LATE MARCH. WITH CLEAR
SKIES MONDAY NIGHT...SOME GUIDANCE SUGGESTS THAT LOWS MAY DROP
BELOW FREEZING...ESPECIALLY ACRS NRN AND ERN SECTIONS. THIS COULD
POSE A PROBLEM GIVEN THAT VEGETATION IS WELL AHEAD OF SCHEDULE DUE
TO THE VERY UNSEASONABLY WARM WEATHER THAT WE HAVE EXPERIENCED.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS THE REGION THROUGH
TUESDAY. THE NEXT SYSTEM WILL BEGIN TO BRING SHOWERS AND
THUNDERSTORMS INTO WESTERN PORTIONS OF THE FA LATE TUESDAY NIGHT
WITH A BETTER CHANCE OF THUNDERSTORM ACTIVITY ON WEDNESDAY. A COLD
FRONT WILL MOVE THROUGH WEDNESDAY NIGHT AND PRECIPITATION WILL END
ACROSS THE FA BY THURSDAY MORNING.
TEMPERATURES WILL WARM ONCE AGAIN BY WEDNESDAY WITH 70S EXPECTED.
TEMPERATURES WILL COOL BEHIND THE FRONT ON THURSDAY.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
THE OVERALL WEATHER CONDITIONS TODAY WILL FEATURE OCCASIONAL RAIN
SHOWERS...AND POSSIBLY SOME THUNDERSTORMS (ESPECIALLY IN THE
AFTERNOON). THE WEATHER SYSTEM CAUSING THIS ACTIVITY IS MOVING
ONLY VERY SLOWLY EASTWARD...WITH ALL OF THE INDIVIDUAL BANDS OF
PRECIPITATION MOVING ALMOST DUE NORTH. THIS MAKES IT MORE
DIFFICULT THAN NORMAL TO PROVIDE EXACT TIMING IN THE FORECAST FOR
EACH INDIVIDUAL BATCH OF SHOWERS MORE THAN A FEW HOURS IN ADVANCE.
MVFR (AND POSSIBLY IFR) CONDITIONS WILL BE POSSIBLE IN THE HEAVIER
SHOWERS...WHICH WOULD OF COURSE BE ESPECIALLY TRUE IN
THUNDERSTORMS.
CHANCES OF HEAVIER PRECIPITATION WILL END BY EVENING. AS AN UPPER
LEVEL LOW PRESSURE SYSTEM MOVES INTO THE REGION...DISORGANIZED
SHOWERS WILL CONTINUE TO BE POSSIBLE THROUGH SATURDAY AND BEYOND.
THE MOISTURE WITH THIS SYSTEM IS NOT ESPECIALLY DEEP SO OCCASIONAL
MVFR CONDITIONS SEEM TO BE THE WORST OF WHAT IS EXPECTED AT THIS
TIME.
OUTLOOK...MVFR CEILINGS POSSIBLE EARLY ON SATURDAY AND AT TIMES
THROUGH SUNDAY. THUNDERSTORMS POSSIBLE ON SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...JGL
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/NOVAK
AVIATION...HATZOS
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
945 AM CDT FRI MAR 23 2012
.DISCUSSION...
DENSE FOG VERY SLOWLY DECREASING THIS MORNING. WILL LET THE ADVISORY
EXPIRE AT 1000 AM...BUT STILL PLAN ON SOME DENSE FOG IN MAINLY NW IA
AND SW MN FOR AN HOUR OR TWO LONGER. OTHERWISE...ANOTHER
UNSEASONABLY WARM DAY AHEAD WITH VERY LITTLE WIND...SO VERY
PLEASANT. HIGHS FROM THE UPPER 60S TO LOWER 70S STILL LOOKS ON
TARGET. /08
&&
.PREV DISCUSSION.../ISSUED AT 416 AM CDT/
INITIAL CONCERN IS DENSE FOG WHICH HAS DEVELOPED ACROSS EASTERN
PORTIONS OF THE FORECAST AREA. HRRR HAD A DECENT HANDLE ON THE
DEVELOPMENT AREA THROUGH THE EARLY MORNING AND TRIES TO EXPAND THE
WESTERN EDGE OF THE FOG WESTWARD TO THE JAMES VALLEY THROUGH 13Z
BEFORE RAPID IMPROVEMENT IN VISIBILITY BETWEEN 15Z AND 17Z. NOT YET
SEEING ANY INDICATION OF MUCH WESTWARD PUSH INTO SOMEWHAT DRIER LOW
LEVEL AIR THOUGH...SO WILL LET DENSE FOG ADVISORY ISSUED EARLIER FOR
AREAS ALONG/EAST OF HURON-SALEM-AKRON LINE STAND. FOG EXPECTED TO
LIFT DURING THE LATE MORNING...THOUGH MAY SEE SOME LINGERING STRATUS
IN EASTERN AREAS INTO THE EARLY AFTERNOON. BETWEEN THAT AND MID-UPPER
LEVEL CLOUDS CONTINUING TO WRAP AROUND SLOWLY DEPARTING UPPER LOW...
EASTERN COUNTIES SHOULD BE PARTLY SUNNY THROUGH THE AFTERNOON WITH
MORE SUNSHINE EXPECTED ALONG/WEST OF I-29. LIGHT WIND FLOW TODAY WILL
LIKELY NOT SCOUR OUT RESIDUAL LOW LEVEL MOISTURE IN THE EAST THOUGH
AND COULD SEE SOME REDEVELOPMENT OF FOG LATE TONIGHT/EARLY SATURDAY
AND HAVE ADDED PATCHY FOG TO AREAS ALONG/EAST OF THE BUFFALO RIDGE
AND IOWA GREAT LAKES.
OTHERWISE BUILDING UPPER RIDGE STILL ON TRACK TO BRING DRY WEATHER
FOR THE WEEKEND. GFS/NAM NOW STRONGER THAN THEIR RUNS FROM 24 HOURS
AGO WITH NORTHERN STREAM WAVE TRACKING ACROSS CANADA THIS WEEKEND.
THIS ALLOWS FRONT AND TRAILING RELATIVELY COOLER AIRMASS TO PUSH
FARTHER SOUTH THROUGH THE UPPER MIDWEST...SIMILAR TO WHAT ECMWF/GEM
WERE SHOWING YESTERDAY MORNING. SATURDAY SHOULD BE QUITE MILD OVER
THE ENTIRE CWA WITH HIGHS IN THE 70S...POSSIBLY HITTING 80 IN PARTS
OF THE MISSOURI VALLEY. FRONTAL BOUNDARY THEN SETS UP NORTHWEST TO
SOUTHEAST ACROSS THE CWA...MAKING TEMPERATURES A LITTLE MORE TRICKY
FOR SUNDAY INTO MONDAY. BOUNDARY WILL SEPARATE 50S AND LOWER 60S IN
MINNESOTA...FROM UPPER 70S-LOWER 80S IN NEBRASKA AND SOUTHWEST SOUTH
DAKOTA...AND THE GRADIENT LIKELY TO BE SOMEWHERE IN OUR CWA. FOR NOW
HAVE COOLED NORTHEAST AREAS FROM PREVIOUS FORECAST FOR SUNDAY/MONDAY
BUT GRADIENT MAY HAVE TO BE TIGHTENED FURTHER IF 925MB TEMPS...WHICH
RANGE FROM 7-9C IN SOUTHWEST MN TO THE LOWER 20S IN SOUTH CENTRAL
SD...PAN OUT FOR MONDAY AFTERNOON.
BOUNDARY COULD ALSO BE FOCUS FOR A FEW SHOWERS OR THUNDERSTORMS LATE
SUNDAY NIGHT AND MONDAY AS LOW LEVEL JET INCREASES AHEAD OF THE NEXT
SYSTEM. INSTABILITY ON THE WEAK SIDE ALONG/NORTHEAST OF THE BOUNDARY
WITH MORE FAVORABLE CAPE BUILDING INTO WARM SECTOR ACROSS SOUTHWEST
CWA MONDAY AFTERNOON...THOUGH PRETTY STOUT CAP REMAINS IN PLACE
THROUGH THE AFTERNOON SO KEEPING POPS ON THE LOW SIDE FOR DAYTIME
HOURS. BETTER CHANCE LOOKS TO BE MONDAY NIGHT AS BOTH GFS/ECMWF SHOW
POTENT MID-UPPER LEVEL WAVE CRASHING INTO THE RIDGE OVER THE EASTERN
DAKOTAS. WITH STRONG DYNAMIC LIFT AND VERY STRONG LOW-MID LEVEL WINDS
AROUND SOUTH SIDE OF DEEP LOW...MAY NOT TAKE MUCH TO PRODUCE DAMAGING
WIND GUSTS WITH ANY STORMS THAT DEVELOP/MOVE INTO THE MORE UNSTABLE
AIR ACROSS THE SOUTHWEST CWA MONDAY NIGHT.
QUICK MOVING COMPACT SYSTEM WILL SHIFT EAST OF THE AREA TUESDAY...
THOUGH COULD SEE SOME SHOWERS WRAP AROUND INTO MAINLY NORTHERN PARTS
OF THE AREA TUESDAY BEFORE DRIER AIR BUILDS IN AND PRECIP THREAT
SHIFTS EAST OF THE AREA TUESDAY NIGHT. WITH STRONG SURFACE LOW
PASSING TO OUR NORTH TUESDAY...LIKELY TO SEE STRONG SYNOPTIC SCALE
FLOW DEVELOP IN WELL-MIXED DEEP WESTERLY FLOW BEHIND THE FRONT.
UPPER RIDGING WILL BRING DRY WEATHER BACK TO THE AREA FOR WEDNESDAY
AND WEDNESDAY NIGHT...WITH UPPER TROUGH SET TO MOVE INTO THE NORTHERN
PLAINS LATE IN THE WEEK. DIFFERENCES IN TIMING AMONG THE MODELS SO
WILL HAVE JUST A SLIGHT CHANCE OF THUNDERSTORMS IN THE WESTERN CWA
THURSDAY...WITH BETTER CHANCE HOLDING OFF UNTIL THURSDAY NIGHT OR
FRIDAY...DEPENDING ON EVENTUAL TIMING. TEMPERATURES WILL REMAIN ON
THE MILD SIDE OF NORMAL...THOUGH LATTER PART OF THE FORECAST PERIOD
SHOULD BE COOLER THAN THE NEXT FEW DAYS.
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
DENSE VLIFR FOG WILL CONTINUE AT KFSD UNTIL AT LEAST 15Z...THEN
SHOULD GRADUALLY LIFT BETWEEN 15Z-17Z. KHON AND KSUX HAVE REMAINED
JUST WEST OF THE DENSE FOG...AND SOME IFR VISIBILITIES AND CEILINGS
MAY BE BRIEFLY POSSIBLE AT THESE LOCATIONS BEFORE 15Z. BY 18Z...ALL
TAF SITES SHOULD IMPROVE TO VFR...HOWEVER SOME LIGHT FOG MAY BE
POSSIBLE AGAIN AFTER MIDNIGHT SATURDAY AT KFSD AND KSUX. /LAFLIN
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR IAZ001>003-
012>014-020>022.
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ071-072-
080-081-089-090-097-098.
NE...NONE.
SD...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR SDZ038>040-
054>056-061-062-067.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
642 AM CDT FRI MAR 23 2012
.DISCUSSION.../ISSUED AT 416 AM CDT/
INITIAL CONCERN IS DENSE FOG WHICH HAS DEVELOPED ACROSS EASTERN
PORTIONS OF THE FORECAST AREA. HRRR HAD A DECENT HANDLE ON THE
DEVELOPMENT AREA THROUGH THE EARLY MORNING AND TRIES TO EXPAND THE
WESTERN EDGE OF THE FOG WESTWARD TO THE JAMES VALLEY THROUGH 13Z
BEFORE RAPID IMPROVEMENT IN VISIBILITY BETWEEN 15Z AND 17Z. NOT YET
SEEING ANY INDICATION OF MUCH WESTWARD PUSH INTO SOMEWHAT DRIER LOW
LEVEL AIR THOUGH...SO WILL LET DENSE FOG ADVISORY ISSUED EARLIER FOR
AREAS ALONG/EAST OF HURON-SALEM-AKRON LINE STAND. FOG EXPECTED TO
LIFT DURING THE LATE MORNING...THOUGH MAY SEE SOME LINGERING STRATUS
IN EASTERN AREAS INTO THE EARLY AFTERNOON. BETWEEN THAT AND MID-UPPER
LEVEL CLOUDS CONTINUING TO WRAP AROUND SLOWLY DEPARTING UPPER LOW...
EASTERN COUNTIES SHOULD BE PARTLY SUNNY THROUGH THE AFTERNOON WITH
MORE SUNSHINE EXPECTED ALONG/WEST OF I-29. LIGHT WIND FLOW TODAY WILL
LIKELY NOT SCOUR OUT RESIDUAL LOW LEVEL MOISTURE IN THE EAST THOUGH
AND COULD SEE SOME REDEVELOPMENT OF FOG LATE TONIGHT/EARLY SATURDAY
AND HAVE ADDED PATCHY FOG TO AREAS ALONG/EAST OF THE BUFFALO RIDGE
AND IOWA GREAT LAKES.
OTHERWISE BUILDING UPPER RIDGE STILL ON TRACK TO BRING DRY WEATHER
FOR THE WEEKEND. GFS/NAM NOW STRONGER THAN THEIR RUNS FROM 24 HOURS
AGO WITH NORTHERN STREAM WAVE TRACKING ACROSS CANADA THIS WEEKEND.
THIS ALLOWS FRONT AND TRAILING RELATIVELY COOLER AIRMASS TO PUSH
FARTHER SOUTH THROUGH THE UPPER MIDWEST...SIMILAR TO WHAT ECMWF/GEM
WERE SHOWING YESTERDAY MORNING. SATURDAY SHOULD BE QUITE MILD OVER
THE ENTIRE CWA WITH HIGHS IN THE 70S...POSSIBLY HITTING 80 IN PARTS
OF THE MISSOURI VALLEY. FRONTAL BOUNDARY THEN SETS UP NORTHWEST TO
SOUTHEAST ACROSS THE CWA...MAKING TEMPERATURES A LITTLE MORE TRICKY
FOR SUNDAY INTO MONDAY. BOUNDARY WILL SEPARATE 50S AND LOWER 60S IN
MINNESOTA...FROM UPPER 70S-LOWER 80S IN NEBRASKA AND SOUTHWEST SOUTH
DAKOTA...AND THE GRADIENT LIKELY TO BE SOMEWHERE IN OUR CWA. FOR NOW
HAVE COOLED NORTHEAST AREAS FROM PREVIOUS FORECAST FOR SUNDAY/MONDAY
BUT GRADIENT MAY HAVE TO BE TIGHTENED FURTHER IF 925MB TEMPS...WHICH
RANGE FROM 7-9C IN SOUTHWEST MN TO THE LOWER 20S IN SOUTH CENTRAL
SD...PAN OUT FOR MONDAY AFTERNOON.
BOUNDARY COULD ALSO BE FOCUS FOR A FEW SHOWERS OR THUNDERSTORMS LATE
SUNDAY NIGHT AND MONDAY AS LOW LEVEL JET INCREASES AHEAD OF THE NEXT
SYSTEM. INSTABILITY ON THE WEAK SIDE ALONG/NORTHEAST OF THE BOUNDARY
WITH MORE FAVORABLE CAPE BUILDING INTO WARM SECTOR ACROSS SOUTHWEST
CWA MONDAY AFTERNOON...THOUGH PRETTY STOUT CAP REMAINS IN PLACE
THROUGH THE AFTERNOON SO KEEPING POPS ON THE LOW SIDE FOR DAYTIME
HOURS. BETTER CHANCE LOOKS TO BE MONDAY NIGHT AS BOTH GFS/ECMWF SHOW
POTENT MID-UPPER LEVEL WAVE CRASHING INTO THE RIDGE OVER THE EASTERN
DAKOTAS. WITH STRONG DYNAMIC LIFT AND VERY STRONG LOW-MID LEVEL WINDS
AROUND SOUTH SIDE OF DEEP LOW...MAY NOT TAKE MUCH TO PRODUCE DAMAGING
WIND GUSTS WITH ANY STORMS THAT DEVELOP/MOVE INTO THE MORE UNSTABLE
AIR ACROSS THE SOUTHWEST CWA MONDAY NIGHT.
QUICK MOVING COMPACT SYSTEM WILL SHIFT EAST OF THE AREA TUESDAY...
THOUGH COULD SEE SOME SHOWERS WRAP AROUND INTO MAINLY NORTHERN PARTS
OF THE AREA TUESDAY BEFORE DRIER AIR BUILDS IN AND PRECIP THREAT
SHIFTS EAST OF THE AREA TUESDAY NIGHT. WITH STRONG SURFACE LOW
PASSING TO OUR NORTH TUESDAY...LIKELY TO SEE STRONG SYNOPTIC SCALE
FLOW DEVELOP IN WELL-MIXED DEEP WESTERLY FLOW BEHIND THE FRONT.
UPPER RIDGING WILL BRING DRY WEATHER BACK TO THE AREA FOR WEDNESDAY
AND WEDNESDAY NIGHT...WITH UPPER TROUGH SET TO MOVE INTO THE NORTHERN
PLAINS LATE IN THE WEEK. DIFFERENCES IN TIMING AMONG THE MODELS SO
WILL HAVE JUST A SLIGHT CHANCE OF THUNDERSTORMS IN THE WESTERN CWA
THURSDAY...WITH BETTER CHANCE HOLDING OFF UNTIL THURSDAY NIGHT OR
FRIDAY...DEPENDING ON EVENTUAL TIMING. TEMPERATURES WILL REMAIN ON
THE MILD SIDE OF NORMAL...THOUGH LATTER PART OF THE FORECAST PERIOD
SHOULD BE COOLER THAN THE NEXT FEW DAYS.
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
DENSE VLIFR FOG WILL CONTINUE AT KFSD UNTIL AT LEAST 15Z...THEN
SHOULD GRADUALLY LIFT BETWEEN 15Z-17Z. KHON AND KSUX HAVE REMAINED
JUST WEST OF THE DENSE FOG...AND SOME IFR VISIBILITIES AND CEILINGS
MAY BE BRIEFLY POSSIBLE AT THESE LOCATIONS BEFORE 15Z. BY 18Z...ALL
TAF SITES SHOULD IMPROVE TO VFR...HOWEVER SOME LIGHT FOG MAY BE
POSSIBLE AGAIN AFTER MIDNIGHT SATURDAY AT KFSD AND KSUX. /LAFLIN
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR IAZ001>003-
012>014-020>022.
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ071-072-
080-081-089-090-097-098.
NE...NONE.
SD...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR SDZ038>040-
054>056-061-062-067.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1147 AM EDT FRI MAR 23 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL TRACK EAST OUT OF THE MID MISSISSIPPI
VALLEY TODAY...THEN SOUTHEAST ACROSS THE TENNESSEE VALLEY ON
SATURDAY. BY MONDAY THE SYSTEM WILL BE OFF THE EAST COAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1140 AM EDT FRIDAY...
ADJUSTED THE ONSET OF CONVECTION AND RAISED TEMPERATURES A FEW
DEGREES THIS AFTERNOON. PLAYED EARLY POPS CLOSE TO HRRR THIS AFTERNOON.
ADJUSTMENTS MADE IN CLOUD COVER THIS AFTERNOON INTO TONIGHT.
AS OF 925 AM EDT FRIDAY...
THE UPPER LOW OVER THE PLAINS WILL MOVE SLOWLY EASTWARD THIS
AFTERNOON AND TONIGHT...THIS WILL PUSH AN OCCLUDED SURFACE FRONT
AND ASSOCIATED MOISTURE EASTWARD. THIS MORNING WRFARW-RNK AND NAM
BRINGS SOME CONVECTION INTO THE WEST THIS AFTERNOON AND SPREAD
STORMS EAST TONIGHT. EXPECT ISOLATED TO SCATTERED THUNDERSTORMS
IN THE AFTERNOON MAINLY WEST OF I77...THEN BETTER COVERAGE ANTICIPATED
AFTER 8PM/00Z TONIGHT. AS PREVIOUS SHIFT POINT OUT...THE THREAT
OF SEVERE THUNDERSTORMS...ESPECIALLY HAIL...INCREASES BY THIS
EVENING INTO SATURDAY AS THE UPPER LOW AND COLD POOL GET CLOSER. THE DAY2
CONVECTIVE OUTLOOK PLACES EAST OF THE MOUNTAINS IN A SLIGHT RISK
ON SATURDAY. MADE SOME MINOR ADJUSTMENTS IN ISC GRIDS FOR
TEMPERATURES...AND POPS FOR THIS AFTERNOON.
AS OF 400 AM EDT FRIDAY...
MODELS SIMILAR WITH TIMING OF APPROACHING OCCLUDED FRONT AND
ASSOCIATED PRECIPITATION. THERE MAY BE ISOLATED TO SCATTERED
THUNDERSTORMS IN THE AFTERNOON BUT THE BETTER PROBABILITY AND
COVERAGE OF PRECIPITATION WILL BE AFTER 8PM/00Z TONIGHT. THE
THREAT OF SEVERE THUNDERSTORMS...ESPECIALLY HAIL...INCREASES BY
THIS EVENING AS THE UPPER LOW AND COLD POOL GET CLOSER.
MADE ONLY MINOR ADJUSTMENTS FOR HIGHS TODAY. STAYED CLOSE TO LAMP
GUIDANCE. MILD DEW POINTS AND CLOUDS COVER WILL HOLD TEMPERATURES
UP TONIGHT. USED A BLEND OF BIAS CORRECTED MET/MAV GUIDANCE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 400 AM EDT FRIDAY...
STRONG CYCLONE WHICH HAS BEEN QUASI-STATIONARY OVER THE SOUTHERN
PLAINS WILL FINALLY TRACK EAST AND ACROSS THE MID ATLANTIC REGION
THIS WEEKEND. THIS FEATURE IS EXPECTED TO SLOWLY TREK ACROSS THE
AREA SATURDAY AND SUNDAY WITH SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS. INITIAL WAVE OF PRECIP SHOULD HAVE PASSED THROUGH THE
CWA BY 12 UTC...8AM SATURDAY...ASSOCIATED WITH THE OCCLUDED SURFACE
FRONT. WITH PASSAGE OF OCCLUSION...SHOULD SEE A BREAK IN THE PRECIP
WITH STRONG INDICATION THAT A DRY SLOT WILL WORK ACROSS THE FCST
AREA PRIOR TO ARRIVAL OF PRECIP UNDERNEATH THE UPPER LOW. IF THIS
BREAK IN PRECIP ASSOCIATED WITH THE DRY SLOT REVEALS ANY
CLEARING...THEN SOLAR INSOLATION LIKELY TO INCREASE INSTABILITY
ACROSS THE CWA INCREASING POTENTIAL FOR SEVERE STORMS. IF THIS TURNS
OUT TO BE THE CASE...WILL THEN NEED TO ENTERTAIN POSSIBILITY OF
SUPERCELLS PER INCREASING DEEP LAYER SHEAR AHEAD OF THE APPROACHING
UPPER VORTEX.
WILL DEFER TO THE STORM PREDICTION CENTER FOR GUIDANCE ON THIS
DEVELOPING SITUATION...BUT IT APPEARS THE GREATEST THREAT FOR SEVERE
WEATHER MAY RESIDE JUST SOUTH OF THE FCST AREA.
FOR SATURDAY NIGHT AND SUNDAY THE UPPER LOW IS PROGGED TO PASS
DIRECTLY OVER THE MID ATLANTIC REGION...THE CENTER OF THE LOW
SPIRALING EAST AND OFF THE COAST SUNDAY NIGHT. FOCUS SATURDAY NIGHT
THROUGH SUNDAY WILL BE FOR SCATTERED TO NUMEROUS SHOWERS AND
EMBEDDED THUNDERSTORMS...THE THREAT FOR PRECIP PERSISTING UNTIL THE
STORM SYSTEM PASSES EAST OF THE REGION SUNDAY NIGHT.
TEMPERATURES WILL TREND DOWNWARD OVER THE WEEKEND...SATURDAY BEING
THE WARMER OF THE TWO DAYS WITH READINGS IN THE 70S PENDING A BIT OF
SUN. SHAVE ABOUT 10 DEGREES OFF THE TMAX FOR SUNDAY COMPARED TO
SATURDAY...SUNDAY STILL TOPPING OUT 4-8 DEGREES ABOVE THE NORM.
QPF FOR THE ENTIRE EVENT...NOON FRIDAY THROUGH MIDNIGHT SUNDAY NIGHT
LOOKS TO BE ON THE ORDER OF ONE TO TWO INCHES...THE HIGHER AMOUNTS
FAVORING CONVEYOR BELT OF DEEPER MOISTURE THAT WILL RESIDE ON THE
NORTH SIDE OF THE CYCLONE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 400 AM EDT FRIDAY...
CYCLONE IS PROGGED TO BE WELL EAST OF THE AREA BY 12Z MONDAY...
BOOTED OUT TO SEA BY A STRONG NORTHERN STREAM TROF THAT WILL DIVE
SOUTHEAST ACROSS NEW ENGLAND FROM EASTERN CANADA. THE COMBINATION OF
THE EXITING CYCLONE AND TROF OVER NEW ENGLAND WILL BRING BREEZY
CONDITIONS TO THE AREA MONDAY AND MONDAY NIGHT...FOLLOWED BY A SUNNY
DRY DAY FOR TUESDAY. TEMPERATURES WILL BEGIN TO MODERATE
TUESDAY...WITH A MORE SIGNIFICANT REBOUND WEDNESDAY AS THE LOW LEVEL
FLOW BECOMES SOUTHWESTERLY. ATTM WILL MAINTAIN A DRY FORECAST FOR
MIDWEEK BUT WILL HAVE TO KEEP EYES ON FAST MOVING FRONT WHICH IS
PROGGED TO MOVE ACROSS THE OHIO VALLEY WEDNESDAY...POSSIBLY ARRIVING
ACROSS OUR THE MTNS AS EARLY AS WEDNESDAY AFTERNOON. THIS SOLUTION
IS ABOUT 12-18 HOURS FASTER THAN PREVIOUS MODEL RUNS.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
AS OF 1140 AM EDT FRIDAY...
THIS MORNING PATCHY FOG DISSIPATED QUICKLY...LEAVING PLENTY OF
SUNSHINE. CLOUDS WILL FILL IN FROM WEST TO EAST THIS AFTERNOON INTO
TONIGHT WITH CEILINGS LOWERING TONIGHT. MODERATE CONFIDENCE THAT
CEILINGS WILL REMAIN VFR AS THE PRECIPITATION BEGINS. AFTER 00Z
TONIGHT...THERE IS A CHANCE THAT BLF AND LWB MAY HAVE MVFR CEILINGS
AND VISIBILITIES WITH CONVECTION AND LOW CLOUDS.
MODELS BRING PRECIPITATION ASSOCIATED WITH THE CLOSED UPPER LOW
OVER THE MIDWEST INTO THE FORECAST AREA AFTER 00Z. MORE WIDESPREAD
RAIN IS EXPECTED SATURDAY THROUGH SUNDAY AS THE LOW MOVES EAST
THEN SOUTHEAST.
DRIER WEATHER AND VFR CONDITIONS ARE EXPECTED BEHIND THE SYSTEM
SUNDAY NIGHT THROUGH TUESDAY.
&&
.CLIMATE...
RECORD HIGH TEMPS FOR TODAY...
3/23
ROANOKE 82 IN 2007
LYNCHBURG 91 IN 2007
DANVILLE 86 IN 1966
BLUEFIELD 77 IN 2007
BLACKSBURG 80 IN 1966
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/KK
SHORT TERM...PM
LONG TERM...WP
AVIATION...AMS
CLIMATE...
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
340 PM EDT Fri Mar 23 2012
.SYNOPSIS...
19Z water vapor and H4 RUC analysis shows northern stream upper
level flow arriving over the northern California/Oregon coast
before ridging well to the north over south-central Canada. Main
feature of note to the south of this flow is the large and stubborn
upper level low spinning over the middle of the country. Upper level
ridge that had been in control of our region is begin de-amplified
and pushed to the east as the previously mentioned upper low begins
to migration toward the eastern seaboard.
At the surface, forecast are resides between a large area of high
pressure off the SE coast, and a weak cold front currently extending
from the western TN valley to the north-central Gulf of Mexico. Deep
southerly flow is begin experienced between these two features into
our zones providing abundant low level moisture. WAA, a slow
increase in synoptic support, and surface focus ahead of the front
are supporting a band of showers and thunderstorms from the open
waters south of Mobile northward to the FL panhandle/eastern
AL/western GA. A few of these storms have shown a tendency to rotate
over the past few hours, and will need to monitored closely.
&&
.SHORT TERM (Tonight through Sunday Night)...
Tonight,
Upper level low will slowly drift eastward with the main cool pool
influence remaining to our north. Several guidance members show a
rapid decrease in convective coverage this evening as the band of
frontal showers/storms continues it painfully slow eastward trek.
Difficult to determine why this decrease is being advertised...and
also having a hard time believing this forecast philosophy due to
the continued deep convection and extensive area of regenerating cold
cloud tops off the MS delta late this afternoon. Would not be
surprised to some decrease in the strength of convection after the
loss of diurnal heating, but will be keeping chance PoPs for showers
and storms in the grids.
Saturday,
Late tonight as we approach dawn, the upper low begins to pivot back
Southward and we see slightly better height falls/QG forcing
overspreading the NE gulf. Global guidance and several CAM members
show a resurgence of convection beginning at this time and
continuing into Saturday morning ahead of the front. This seems
reasonable and will show likely rain chances around 60% along and
east of a line roughly from Panama City to Albany. Still expecting a
scattering of showers to the west of this line during the morning
hours, however with the passage of the surface front by early
afternoon will see drier air and falling rain chances for these
western zones.
This will be at least a marginal threat for some strong to severe
thunderstorms over mainly the eastern half of the region during the
daylight hours of Saturday. Currently the most favorable
kinematics/thermodynamics appear to align a bit to our NE tomorrow,
however with 30-40kts of deep layer shear present, the potential for
organized updraft will exist, especially if we experience enough
sunny breaks to add to the instability. Will continue to monitor
this situation, and a more detailed briefing packet on the threat is
available at
http://www.srh.noaa.gov/images/tae/briefing/EMBriefingMarch232012.pdf
.
Saturday Night,
Upper level low begins to make more progressive progress. Energy
rounding the base of the low now looks to give the final push to
accelerate the surface front south and eastward out of our region.
Therefore will see the last of the showers/storms over the SE Big
Bend zones ending during the pre-dawn hours. The arrival of a drier
airmass will allow temps to drop into the 50s by sunrise.
Sunday/Sunday Night,
A pleasant and dry day on tap for the second half of the upcoming
weekend. Deep layer NW flow will continue to supply a drier airmass
to the region with just a sct fair weather cumulus field developing
in the afternoon. Despite 850mb temps dropping to between 8-9C,
decent diurnal mixing and the stronger late March sun should still
allow our temperatures to rise to within a couple of degrees of 80.
A secondary trough or dry frontal passage will occur Sunday evening
setting up several days of dry and seasonable weather for the
beginning of next week.
&&
.LONG TERM (Monday through next Friday)...
The closed upper low and associated trough will be exiting off the
mid-Atlantic coast Sunday night. A low amplitude upper ridge will
build in from the west early next week. The ridge flattens to nearly
zonal by Thursday as a strong shortwave translates across the
northern tier states into New England. The GFS shows a shortwave
tracking across Texas Thursday lifting into the Missouri/Tennessee
Valleys with a spoke of energy extending SEWD into our region by the
end of the period.
At the surface, high pressure centered north of the Great Lakes
Monday night will drop south-southeast becoming centered east of the
Carolina`s on Wednesday. The high slides east thereafter with the
ridge axis dropping south across the Florida peninsula and allowing
a cold front to drop down from the north. This boundary may slip
into our northern zones Friday before lifting north as a warm front
late in the day in response to the next cold front advancing from
the west. Temperatures will continue above seasonal levels through
the extended period.
&&
.AVIATION...
SCT TSRA will impact area terminals through the remainder of the
afternoon and into the evening. After a break overnight, rain and
thunderstorms are expected to resume around sunrise Saturday.
Outside of the thunderstorms, expect VFR conditions through the
evening, with MVFR cigs late tonight into tomorrow morning.
&&
.MARINE...
A weak cold front will approach the forecast water tonight and cross
from west to east during the Saturday. Winds may approach cautionary
levels at times ahead of the front, but not anticipating advisory
conditions. Cold front will exits south of the area Saturday night
turning winds offshore for the second half of the weekend.
&&
.FIRE WEATHER...
It is likely that many areas will see a wetting rain ahead of an
approaching cold front between this afternoon and Saturday
afternoon. The cold front will be slow to move across the region on
Saturday. However, it does appear that it will clear our Southeast
AL and inland FL Panhandle counties (along and north of I-10) early
enough to allow afternoon relative humidity to drop below 35
percent. Forecast dispersion indices are not quite high enough to
reach red flag criteria and the new forecast ERC values that will
come in later this afternoon may drop as well. We therefore do not
plan on issuing any red flag products for Saturday at this time. The
front will clear the remainder of the forecast area Saturday night
setting up a dry and breezy day on Sunday. It will not be quite dry
enough to reach red flag criteria across our AL and GA zones.
However, the combination of low RH, high dispersion and high 20-ft
winds will likely produce red flag conditions across inland portions
of FL. Watches and/or warnings will likely be issued by later shifts
for Sunday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 62 82 54 82 50 / 50 60 30 10 0
Panama City 67 80 59 80 58 / 50 60 10 10 0
Dothan 61 83 55 81 53 / 40 40 10 10 0
Albany 61 81 54 79 52 / 50 60 20 10 0
Valdosta 62 80 55 79 53 / 50 60 40 10 0
Cross City 62 81 58 81 51 / 30 60 40 10 0
Apalachicola 67 75 59 77 54 / 50 60 30 10 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...None.
GM...None.
&&
$$
Mroczka/Camp/Barry/Wool
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
331 PM CDT FRI MAR 23 2012
.MESOSCALE DISCUSSION...
1200 PM CDT
A SWATH OF SHOWERS FROM SOUTHEAST WISCONSIN THROUGH NORTHWEST
INDIANA CONTINUE TO MOVE NORTHEAST. BASED ON THE LATEST RUC
ANALYSIS...THE SLOW MOVING UPPER LEVEL LOW IS CURRENTLY CENTERED
OVER MISSOURI. THE CORRESPONDING SURFACE LOW IS OVER EAST CENTRAL
MISSOURI AND SLOWLY MOVING INTO SOUTHERN INDIANA. LATEST WATER
VAPOR IMAGERY SHOWS SPIRALS OF DRIER AIR CIRCLING THE UPPER LEVEL
LOW...WHICH CORRELATE TO AREAS OF CLEARING OVER NORTH CENTRAL
ILLINOIS.
UNDER THE AREAS OF CLEARING...LOW LEVEL LAPSE RATES HAVE BEEN
RAPIDLY INCREASING. THE RUC HAS A GOOD HANDLE ON MID LEVEL LAPSE
RATES...AND INDICATES STEEPER MID LEVEL LAPSE RATES WILL BE
ADVECTED FROM CENTRAL ILLINOIS THROUGH NORTHERN ILLINOIS. AN AREA
OF CONVERGENCE IS ALSO VISIBLE IN THE SURFACE WIND OBS ALONG THE
ILLINOIS INDIANA STATE LINE. THE STEEP LOW LEVEL LAPSE RATES AND
AREA OF CONVERGENCE HAVE RESULTED IN CONVECTIVE SHOWERS DEVELOPING
ACROSS THE SOUTHERN HALF OF THE CWA. A FEW LIGHTNING STRIKES HAVE
BEEN DETECTED...BUT GIVEN THE ENVIRONMENT...EXPECTING AN INCREASE
IN CONVECTION THROUGH THE AFTERNOON.
CONCERNING THE SEVERE THREAT...THERE IS ADEQUATE
MOISTURE...FORCING...AND SHEAR FOR SEVERE THUNDERSTORM
DEVELOPMENT. HOWEVER INSTABILITY APPEARS TO BE WEAK TO MODERATE AT
BEST. CURRENTLY...THERE IS NO SIGNIFICANT SURFACE BASED CAPE TO
SPEAK OF. RUC AND HRR ANALYSES INDICATE A MAX OF 1500 J/KG THIS
AFTERNOON...WHILE THE SREF HINTS AT A BRIEF MAX OF AT LEAST 500
J/KG. BOTH THE RUC AND HRR SEEM A BIT AMBITIOUS WITH CAPE VALUES
THIS AFTERNOON...THEREFORE EXPECTING ABOUT 1000 J/KG TO WORK WITH.
IF INSTABILITY INCREASES...THE LIKELIHOOD OF MORE WIDESPREAD
SEVERE WEATHER WOULD ALSO INCREASE.
THE MAIN SEVERE WEATHER THREATS ARE HAIL AND DAMAGING WINDS. NAM
MODEL SOUNDINGS ARE ON TREND WITH CURRENT CONDITIONS AND SHOW A
DECENT INVERTED V FEATURE IN DOWNSTATE ILLINOIS THIS
AFTERNOON...WHICH WOULD INDICATE A GOOD CHANCE FOR STRONG
DOWNDRAFTS AND DAMAGING WINDS. MIDLAYER SHEAR IS PLENTIFUL SINCE
WE ARE ON THE NORTHEAST SIDE OF THE UPPER LEVEL LOW. LATEST RUC
ANALYSIS SHOWS UPWARDS OF 60 KT OF 0-6KM SHEAR THROUGH NORTHEAST
ILLINOIS AND NORTHWEST INDIANA. GIVEN A STRONG ENOUGH UPDRAFT AND
STRONG SHEAR...SEVERE HAIL IS POSSIBLE. HOWEVER WITH THE DRY LOW
LEVELS AND THE 12Z ILX SOUNDING INDICATING A FREEZING LEVEL
BETWEEN 9-10 KFT...ONLY EXPECTING HAIL UP TO QUARTER SIZE AT THIS
TIME. AN AREA OF ENHANCED LOW LEVEL HELICITY IS SHIFTING
NORTHWARD AND THIS COULD LEAD TO A FEW ROTATING UPDRAFTS AND
POSSIBLY AN ISOLATED TORNADO OR TWO.
JEE
&&
.DISCUSSION...
340 AM CDT
LARGE UPPER LOW ACROSS THE CENTRAL CONUS IS TAKING ITS TIME SWEET
MOVING TO THE EAST-NORTHEAST. AS THIS FEATURE CONTINUES ITS TREK
INTO THE OHIO VALLEY THROUGH THE WEEKEND...IT WILL BRING SHOWERS
WITH SOME THUNDER TO THE AREA...AS WELL AS CONTINUE TO KEEP THE
ABOVE NORMAL TEMPERATURES THROUGH THE WEEKEND. OVERNIGHT SUNDAY
AND INTO THE START OF THE WORKWEEK WILL SEE CONDITIONS
CHANGE...WITH TEMPERATURES FALLING A LITTLE CLOSER TO NORMAL...BUT
DRY.
DRY SLOT NOTED ON WATER VAPOR IMAGERY THIS MORNING WILL CONTINUE TO
CURL NORTH ACROSS THE CWA THIS MORNING AND WILL LEAD TO SOME DRYING
COME THE MORNING HOURS...AND OVERALL SHOWERY CONDITIONS WILL BE ON
THE WANE FOR MOST. AREAS ACROSS THE WEST AND SOUTH MAY ALSO HAVE THE
BETTER CHANCES AT SEEING SOME HINTS OF SUN...BUT THAT WILL BE SHORT
LIVED AS CHANCES FOR SHOWERS AND THUNDER INCREASE INTO THE AFTERNOON.
ONE OF THE BIGGER CHANGES TO THE GOING FORECAST IS WITH RESPECT TO
THE MASSIVE AND PERSISTENT STACKED LOW THAT IS SLOWLY MOVING ACROSS
THE CENTRAL US. THE CHANGE TONIGHT IS THAT THE LOW IS NOW PROGGED TO
MOVE A LITTLE FARTHER NORTH THAN EARLIER ANTICIPATED. BY BRINGING
THE CORE A LITTLE FARTHER NORTH...WE ARE NOW GOING TO INTRODUCE A
LITTLE COOLER AIR ALOFT BY THE AFTERNOON HOURS. SURFACE DEWPOINTS IN
THE UPPER 50S TO LOWER 60S TO CONTINUE INTO THE AFTERNOON
HOURS...AND WILL HELP TO SUPPORT MEAN LAYER CAPE VALUES IN THE
800-1000 J/KG REGION. LOWER LEVEL SHEAR IS PRETTY MARGINAL...THOUGH
FORECAST SOUNDINGS DO SHOW A SIGNAL OF CURL TO THE HODOGRAPH. SPC
SREF ANALYSIS INDICATES EFFECTIVE SHEAR TO BE IN THE 30-35-40 KT
REALM FROM THE 18 TO TO 00Z HOUR FROM CMI TO IKK AND FLIRTING WITH
ORD /THOUGH REACHING 40KT MAY BE A STRETCH/...THEN IN THE 00Z TO
06Z HOURS SHIFTING EAST AND ACROSS NORTHERN INDIANA. PREVIOUS OFF
HOUR RUNS OF THE NAM AND GFS ALSO INDICATE A LITTLE SPEED MAX
RIPPLING THROUGH...WITH THE FAVORED ENTRANCE REGION MOVING
OVERHEAD INTO THE AFTERNOON HOURS. THAT HAS NOW SHIFTED A LITTLE
EAST...AND WHILE IT ISNT EXACTLY THE MOST FAVORABLE SETUP FOR
CONVECTION...CANT RULE OUT MORE THAN RAIN AND WILL ADD THE MENTION
OF THUNDER THROUGH THE AFTERNOON HOURS. THE BIGGEST THREAT WITH
THE COOLING ALOFT AND THE INCREASED LAPSE RATES WILL BE MARGINAL
HAIL...BUT CAN FORESEE SOME STORMS THAT POP THIS AFTERNOON TAKING
ON SIMILAR CHARACTERISTICS TO WHAT WAS OBSERVED IN THE LATE
EVENING ON THURSDAY...WHERE A FEW MULTICELLULAR CLUSTERS SHOW
SOME MID LEVEL ROTATION...AND THAT MAY GET CLOSE TO THE SURFACE.
BUT THE THREAT APPEARS LOW AND WILL BE MORE FOCUSED ON THE HAIL
THREAT...ESPECIALLY WITH THE LACK OF LOWER LEVEL SHEAR.
THE STREAK OF RECORD BREAKING TEMPERATURES AT ORD LOOKS TO FINALLY
BE OVER...AS THE RECORD HIGH FOR THE DATE IS 80 DEGREES. THE SURFACE
GRADIENT IS INCREDIBLY BAGGY THIS MORNING AND FLOW IS GENERALLY SSE
TO SE ACROSS THE REGION. AS THE SURFACE LOW TRACKS EAST ACROSS
SOUTHERN ILLINOIS...WINDS WILL BECOME MORE EASTERLY AND AREAS ALONG
THE LAKEFRONT WILL BE UNDER THE INFLUENCE OF THE COOLER
MARINE AIRMASS...AND THAT WILL HELP TO KEEP THE TEMPERATURES
CONSIDERABLY LOWER THAN HAS BEEN FELT THE PAST WEEK...GENERALLY
PEAKING IN THE MID/UPPER 60S. AN INTERESTING NOTE...EVEN WITH FLOW
OFF OF THE LAKE IN MID MARCH...DOWN TOWN CHICAGO WAS AT 54 DEGREES
AS OF 4AM. LAST YEAR LAKE MICHIGAN TEMPERATURES WERE 42 AT THE
SHORE...39 AT THE CRIB AND 38 AT MICHIGAN CITY INTAKE. THIS
YEAR...THEY ARE 49, 46 AND 44 RESPECTIVELY. THAT GOES TO HIGHLIGHT
HOW BIG OF A PLAYER THE LAKE CONTINUES TO PLAY IN TEMPERATURES.
WHILE IT WILL BE COOLER THAN WHAT HAS FELT LIKE THE NEW NORM...IT
WILL STILL BE ABOVE THE OFFICIAL NORMAL...WHICH IS 49 DEGREES.
GRANTED...IF AREAS WEST DO CLEAR OUT FOR LONGER THAN
ANTICIPATED...THEY WILL WARM CONSIDERABLY MORE THAN AREAS TO THE
EAST...BUT STILL NOT ANTICIPATING ANY RECORDS FOR THE DAY /AS
ROCKFORD/S RECORD FOR TODAY IS 82/. CIN BUILDS INTO THE EVENING AS
UPPER FLOW BACKS TO THE NORTHWEST AND THEN NORTH...AS THE DISH POT
LOW WOBBLES/MEANDERS EAST. CHANCE OF SHOWERS TO PERSIST THROUGH
THE DAY ON SATURDAY WITH DEEP CYCLONIC FLOW...THOUGH THE BETTERS
CHANCES WILL BE CLOSER TO THE LOW AND SOUTH ACROSS CENTRAL
ILLINOIS AND WEST CENTRAL INDIANA.
LONG TERM TRENDS STILL INDICATE BIGGER COOL DOWN SUNDAY NIGHT AND
INTO MONDAY. THE DISH POT WILL BE IN THE VICINITY OF THE LOWER
OHIO VALLEY BY THE END OF THE WEEKEND...TURNING ALL FLOW TO THE
NORTH AND NORTHWEST IN THAT TIME FRAME. THE GOOD NEWS IS THAT ANY
STRONG ADVECTION OF COLDER AIR THAT THE SYSTEM MAY HAVE HAD A WEEK
OR SO AGO WHEN IT WAS RAMPING UP...HAS BUT WASHED ITSELF OUT THIS
PAST WEEK. H8 TEMPS ARE PROGGED TO ONLY DIP INTO THE +6 TO +8
REALM WHICH MEANS THAT HIGHS ONLY EXPECTED IN THE LOWER 50S NORTH
OF I-88...TOUCHING 60 WELL SOUTH AND CLOSER TOWARDS ILX/S AREA OF
RESPONSIBILITY.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SHRA/TSRA OVER/NEAR THE TERMINALS NEXT 1-2 HRS...MORE
ISOLD/SCATTERED ACTIVITY POSSIBLE REMAINDER OF AFTERNOON/EARLY
EVENING.
* BRIEF IFR POSSIBLE WITH SHRA/TSRA THAT PASS OVERHEAD.
* PRIMARILY VFR CIGS ARRIVING WITH PATCHY MVFR REMAINING INTO
EARLY EVENING.
* MVFR VSBY MAY CONTINUE AT ORD WITH FLOW OFF LAKE MICHIGAN.
* EAST TO NORTHEAST WINDS EXPECTED TO CONTINUE THROUGH THE
AFTERNOON POTENTIALLY BECOMING EAST-SOUTHEAST YET THIS AFTERNOON
BEFORE BECOMING LIGHT AND VARIABLE. MDW SHOULD HAVE THE MOST
VARIABILITY.
* ANOTHER ROUND OF SHRA/TSRA POSSIBLE THIS EVENING BUT MAY REMAIN
JUST TO THE SOUTH.
* DECENT POTENTIAL FOR DENSE FOG DEVELOPMENT OVERNIGHT THROUGH
DAYBREAK SATURDAY.
* IFR IMPROVING TO VFR SATURDAY MORNING AND POSSIBLY VFR SATURDAY
AFTERNOON.
MDB
//DISCUSSION...UPDATED 20Z...
BULK OF THE SHRA/TSRA ACTIVITY NOW SKIRTING ORD/MDW/DPA TO THE
NORTHEAST AND SHOULD CONTINUE TO LIFT AWAY FROM THE
TERMINALS...INCLUDING GYY...OVER THE NEXT HOUR OR SO. PREVAILING
CIGS ARE QUICKLY IMPROVING TO VFR AND THIS TREND SHOULD REMAIN
INTO THE EVENING AND TAF CIGS MAY BE TOO PESSIMISTIC. CONVECTION
MOVING NORTHWARD ACROSS CENTRAL ILLINOIS WILL MAKE A RUN TOWARD
THE TERMINALS THIS EVENING BUT IT IS NOT YET CLEAR AS TO HOW
ORGANIZED OR WELL DEVELOPED THEY WILL BE AS THEY APPROACH...BUT WILL
CONTINUE TO MONITOR. TS MAY NEED TO BE ADDED FOR THE EVENING.
WINDS REMAIN VARIABLE WITH SHRA/TSRA STARTING TO IMPACT THE FLOW.
EXPECT MAINLY AN EASTERLY DIRECTION WITH FLUCTUATIONS TO NORTHEAST
AND SOUTHEAST. CONDS AT RFD HAVE BEEN MORE STEADY STATE WITH MOST
SHRA/TSRA ACTIVITY TO THE NORTH AND VFR PREVAILING...BUT WINDS
HAVE BEEN MORE VARIABLE BETWEEN SOUTH AND EAST.
FROM 18Z...
UPPER LOW CONTINUES TO SPIN OVER SOUTHERN MISSOURI RESULTING IN
LOW CIGS/VSBY AND SHRA/TSRA. CONDITIONS HIGHLY VARIABLE ACROSS THE
TERMINALS WITH THE WORST CONDITIONS ACROSS THE CHICAGO METRO AND
NORTHWEST INDIANA. A BAND OF THUNDERSTORMS HAS DEVELOPED OVER THE
LAST HOUR OR SO FROM ORD SOUTHWARD AND IS LIFTING NORTH. THE BULK
OF THIS ACTIVITY WILL LIFT TO THE NORTH OF THE CHI AREA TERMINALS
IN THE NEXT FEW HOURS WITH ADDITIONAL ACTIVITY POSSIBLE THROUGH
LATE AFTERNOON BUT APPEARING TO BE MUCH LESS ORGANIZED. IFR/MVFR
CIGS CONTINUE IN THIS SAME AREA AND IFR CIGS SHOULD IMPROVE TO LOW
END MVFR OVER THE NEXT HOUR OR SO.
MVFR CIGS WILL LIKELY PERSIST THROUGH THE AFTERNOON AT
DPA/ORD/MDW/GYY WHILE VFR CONTINUES AT RFD. THERE MAY BE SOME
IMPROVEMENT TO VFR LATE THIS AFTERNOON AND EARLY THIS EVENING BUT
THIS IS NOT YET CLEAR. VARIABLE EAST TO NORTHEAST WINDS WILL
CONTINUE AT ORD/MDW/DPA WITH GYY EXPECTED TO FLIP TO EAST OR
NORTHEAST SOMETIME LATER THIS AFTERNOON BUT SHOWER ACTIVITY MAY
KEEP THIS FROM OCCURRING.
ANOTHER ROUND OF CONVECTION SHOULD MOVE NORTHWARD ACROSS CENTRAL
ILLINOIS LATE THIS AFTERNOON. THE BIG QUESTION WILL BE HOW FAR
NORTH THIS WILL BE ABLE TO MOVE. WILL LIMIT PRECIP/TS MENTION IN
THE TAF FOR THIS EVENING BUT WILL NEED TO MONITOR CLOSELY. RIGHT
NOW BEST TIME FRAME FOR THIS WOULD BE MID OR LATE EVENING. LOW
LEVEL FLOW WILL BECOME LIGHT AND VARIABLE OVERNIGHT WHICH WILL
COMBINE WITH MOIST/SATURATED GROUND TO SUPPORT GOOD POTENTIAL FOR
FOG DEVELOPMENT. NOT CLEAR HOW LOW VSBY WILL GO BUT 1/2SM OR LESS
IS PLAUSIBLE...ESPECIALLY AT DPA/RFD. LESS CONFIDENCE IN VSBY THIS
OCCURRING AT ORD/MDW AND EVEN GYY BUT SOME FORM OF IFR VSBY
APPEARS LIKELY. NORTH-NORTHEAST FLOW WILL BE IN PLACE SATURDAY AS
THE UPPER LOW STARTS TO SHIFT EASTWARD AND IFR SHOULD IMPROVE TO
MVFR SOMETIME LATER SATURDAY MORNING...WITH VFR POSSIBLE SOMETIME
SATURDAY AFTERNOON.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN MOST WIDESPREAD SHRA/TSRA ACTIVITY LIFTING
NORTH OF THE TERMINALS NEXT HOUR OR SO. LOW-MEDIUM CONFIDENCE IN
SCATTERED/ISOLD POTENTIAL THROUGH EARLY EVENING.
* MEDIUM-HIGH CONFIDENCE IN BRIEF IFR OCCURRING WITH ANY PASSING
SHRA/TSRA.
* MEDIUM-HIGH CONFIDENCE IN PREVAILING CIGS IMPROVING TO VFR AND
CONTINUING INTO MID EVENING.
* HIGH CONFIDENCE IN GENERAL EAST TO NORTHEAST WIND DIRECTION WITH
VARIABILITY BUT MEDIUM CONFIDENCE IN TIMING OF MORE EAST-
SOUTHEAST DIRECTION THIS EVENING.
* LOW CONFIDENCE IN POTENTIAL FOR ANOTHER ROUND OF SHRA/TSRA
EARLY/MID EVENING BUT THIS MAY STAY JUST TO THE SOUTH.
* MEDIUM-HIGH CONFIDENCE IN IFR FOG DEVELOPMENT TONIGHT THROUGH
MID SATURDAY MORNING WITH LOW-MEDIUM CONFIDENCE IN HOW LOW VSBY
WILL BE.
* MEDIUM CONFIDENCE IN IFR IMPROVING TO VFR THROUGH SATURDAY BUT
LOW CONFIDENCE ON TIMING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...VFR. PSBL FG DEVELOPMENT.
SUNDAY...VFR.
MONDAY...VFR.
TUESDAY...VFR. PSBL MVFR CIGS WITH CHC SHRA/ISO TS.
WEDNESDAY...MVFR EARLY TRENDING VFR. CHC RA/TS EARLY.
THURSDAY...VFR.
BEACHLER
&&
.MARINE...
321 PM CDT
WHILE THERE MAY BE SOME PATCHY DENSE FOG NEAR THE WESTERN
SHORE THROUGH TONIGHT...THE PRIMARY CONCERN IS A PERIOD OF UNSTABLE
CONDITIONS LATE SUNDAY INTO EARLY MONDAY...WHICH WILL LEAD TO
STRONGER NORTHERLY WINDS. THEN ON TUESDAY...STRONG SOUTHERLY FLOW
WILL DEVELOP...BUT THE AIR MASS IS EXPECTED TO BECOME INCREASINGLY
STABLE OVER THE LAKE.
INITIALLY...BROAD LOW PRESSURE OVER THE OHIO VALLEY WILL SHIFT
SLOWLY EAST ACROSS THE OHIO VALLEY THROUGH LATE SATURDAY...WITH
WINDS TURNING NORTHERLY BUT REMAINING FAIRLY LIGHT AS THE AIR MASS
OVER THE LAKE WILL STILL BE MILD...LEADING TO STABLE CONDITIONS.
HOWEVER...ON SUNDAY...A COLD FRONT PASSAGE WILL LEAD TO A SHOT OF
REINFORCING COLD AIR AS STRONG HIGH PRESSURE PRESSES DOWN FROM
NORTHERN ONTARIO. THIS WILL BE THE FIRST PUSH OF COLD AIR OVER THE
LAKE IN QUITE A WHILE...SO THE LAKE IS EXCEPTIONALLY MILD FOR LATE
MARCH. THUS...AIR TEMPERATURES BELOW FREEZING ALOFT MOVING OVER THE
MILD LAKE WILL ENABLE MIXING DOWN OF STRONGER WINDS AS THE STRONG
HIGH PRESSURE BUILDING IN RESULTS IN A TIGHT NORTHERLY PRESSURE
GRADIENT. THE COLD AIR WILL TAKE SOME TIME TO DEEPEN...SO THE TARGET
PERIOD FOR STRONGEST NORTHERLY WINDS IS SUNDAY NIGHT INTO EARLY
MONDAY...STARTING WITH THE NORTH HALF...THEN TRANSITIONING DOWN THE
LAKE. HAVE PEGGED THIS TIME FRAME FOR NORTH AND NORTHEAST WINDS UP
TO 30 KT...BUT CANNOT RULE OUT LOW END GALES...SO THIS PERIOD WILL
NEED TO BE MONITORED. THE STRONG NORTHERLY WINDS AND BUILDING WAVES
WILL ALSO LEAD TO A HIGH LIKELIHOOD OF CONDITIONS HAZARDOUS TO SMALL
CRAFT FOR THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE WATERS LATE
SUNDAY NIGHT OR EARLY MONDAY MORNING INTO MONDAY EVENING. WINDS WILL
BRIEFLY SUBSIDE AND TURN SOUTHEAST LATE MONDAY NIGHT AS THE HIGH
QUICKLY MOVES EAST.
STRONG LOW PRESSURE WILL APPROACH THE UPPER GREAT LAKES FROM THE
NORTHERN PLAINS ON TUESDAY...STRENGTHENING THE SOUTHERLY FLOW...BUT
AT THIS POINT...THE AIR MASS MOVING ACROSS THE LAKE WILL BE
MILD...AND GUSTS WILL BE LIMITED BY INCREASINGLY STABLE CONDITIONS.
WILL CERTAINLY NEED TO MONITOR THIS PERIOD AS WELL...AS THE WINDS
NOT FAR ABOVE THE STABLE LAYER WILL BE QUITE STRONG. COLDER...UNSTABLE
CONDITIONS AND STRONGER WESTERLY WINDS WILL RETURN ON WEDNESDAY
AFTER THE COLD FRONT TRAILING FROM THE LOW PRESSURE SWEEPS ACROSS
THE LAKE.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
306 PM CDT FRI MAR 23 2012
.MESOSCALE DISCUSSION...
1200 PM CDT
A SWATH OF SHOWERS FROM SOUTHEAST WISCONSIN THROUGH NORTHWEST
INDIANA CONTINUE TO MOVE NORTHEAST. BASED ON THE LATEST RUC
ANALYSIS...THE SLOW MOVING UPPER LEVEL LOW IS CURRENTLY CENTERED
OVER MISSOURI. THE CORRESPONDING SURFACE LOW IS OVER EAST CENTRAL
MISSOURI AND SLOWLY MOVING INTO SOUTHERN INDIANA. LATEST WATER
VAPOR IMAGERY SHOWS SPIRALS OF DRIER AIR CIRCLING THE UPPER LEVEL
LOW...WHICH CORRELATE TO AREAS OF CLEARING OVER NORTH CENTRAL
ILLINOIS.
UNDER THE AREAS OF CLEARING...LOW LEVEL LAPSE RATES HAVE BEEN
RAPIDLY INCREASING. THE RUC HAS A GOOD HANDLE ON MID LEVEL LAPSE
RATES...AND INDICATES STEEPER MID LEVEL LAPSE RATES WILL BE
ADVECTED FROM CENTRAL ILLINOIS THROUGH NORTHERN ILLINOIS. AN AREA
OF CONVERGENCE IS ALSO VISIBLE IN THE SURFACE WIND OBS ALONG THE
ILLINOIS INDIANA STATE LINE. THE STEEP LOW LEVEL LAPSE RATES AND
AREA OF CONVERGENCE HAVE RESULTED IN CONVECTIVE SHOWERS DEVELOPING
ACROSS THE SOUTHERN HALF OF THE CWA. A FEW LIGHTNING STRIKES HAVE
BEEN DETECTED...BUT GIVEN THE ENVIRONMENT...EXPECTING AN INCREASE
IN CONVECTION THROUGH THE AFTERNOON.
CONCERNING THE SEVERE THREAT...THERE IS ADEQUATE
MOISTURE...FORCING...AND SHEAR FOR SEVERE THUNDERSTORM
DEVELOPMENT. HOWEVER INSTABILITY APPEARS TO BE WEAK TO MODERATE AT
BEST. CURRENTLY...THERE IS NO SIGNIFICANT SURFACE BASED CAPE TO
SPEAK OF. RUC AND HRR ANALYSES INDICATE A MAX OF 1500 J/KG THIS
AFTERNOON...WHILE THE SREF HINTS AT A BRIEF MAX OF AT LEAST 500
J/KG. BOTH THE RUC AND HRR SEEM A BIT AMBITIOUS WITH CAPE VALUES
THIS AFTERNOON...THEREFORE EXPECTING ABOUT 1000 J/KG TO WORK WITH.
IF INSTABILITY INCREASES...THE LIKELIHOOD OF MORE WIDESPREAD
SEVERE WEATHER WOULD ALSO INCREASE.
THE MAIN SEVERE WEATHER THREATS ARE HAIL AND DAMAGING WINDS. NAM
MODEL SOUNDINGS ARE ON TREND WITH CURRENT CONDITIONS AND SHOW A
DECENT INVERTED V FEATURE IN DOWNSTATE ILLINOIS THIS
AFTERNOON...WHICH WOULD INDICATE A GOOD CHANCE FOR STRONG
DOWNDRAFTS AND DAMAGING WINDS. MIDLAYER SHEAR IS PLENTIFUL SINCE
WE ARE ON THE NORTHEAST SIDE OF THE UPPER LEVEL LOW. LATEST RUC
ANALYSIS SHOWS UPWARDS OF 60 KT OF 0-6KM SHEAR THROUGH NORTHEAST
ILLINOIS AND NORTHWEST INDIANA. GIVEN A STRONG ENOUGH UPDRAFT AND
STRONG SHEAR...SEVERE HAIL IS POSSIBLE. HOWEVER WITH THE DRY LOW
LEVELS AND THE 12Z ILX SOUNDING INDICATING A FREEZING LEVEL
BETWEEN 9-10 KFT...ONLY EXPECTING HAIL UP TO QUARTER SIZE AT THIS
TIME. AN AREA OF ENHANCED LOW LEVEL HELICITY IS SHIFTING
NORTHWARD AND THIS COULD LEAD TO A FEW ROTATING UPDRAFTS AND
POSSIBLY AN ISOLATED TORNADO OR TWO.
JEE
&&
.DISCUSSION...
340 AM CDT
LARGE UPPER LOW ACROSS THE CENTRAL CONUS IS TAKING ITS TIME SWEET
MOVING TO THE EAST-NORTHEAST. AS THIS FEATURE CONTINUES ITS TREK
INTO THE OHIO VALLEY THROUGH THE WEEKEND...IT WILL BRING SHOWERS
WITH SOME THUNDER TO THE AREA...AS WELL AS CONTINUE TO KEEP THE
ABOVE NORMAL TEMPERATURES THROUGH THE WEEKEND. OVERNIGHT SUNDAY
AND INTO THE START OF THE WORKWEEK WILL SEE CONDITIONS
CHANGE...WITH TEMPERATURES FALLING A LITTLE CLOSER TO NORMAL...BUT
DRY.
DRY SLOT NOTED ON WATER VAPOR IMAGERY THIS MORNING WILL CONTINUE TO
CURL NORTH ACROSS THE CWA THIS MORNING AND WILL LEAD TO SOME DRYING
COME THE MORNING HOURS...AND OVERALL SHOWERY CONDITIONS WILL BE ON
THE WANE FOR MOST. AREAS ACROSS THE WEST AND SOUTH MAY ALSO HAVE THE
BETTER CHANCES AT SEEING SOME HINTS OF SUN...BUT THAT WILL BE SHORT
LIVED AS CHANCES FOR SHOWERS AND THUNDER INCREASE INTO THE AFTERNOON.
ONE OF THE BIGGER CHANGES TO THE GOING FORECAST IS WITH RESPECT TO
THE MASSIVE AND PERSISTENT STACKED LOW THAT IS SLOWLY MOVING ACROSS
THE CENTRAL US. THE CHANGE TONIGHT IS THAT THE LOW IS NOW PROGGED TO
MOVE A LITTLE FARTHER NORTH THAN EARLIER ANTICIPATED. BY BRINGING
THE CORE A LITTLE FARTHER NORTH...WE ARE NOW GOING TO INTRODUCE A
LITTLE COOLER AIR ALOFT BY THE AFTERNOON HOURS. SURFACE DEWPOINTS IN
THE UPPER 50S TO LOWER 60S TO CONTINUE INTO THE AFTERNOON
HOURS...AND WILL HELP TO SUPPORT MEAN LAYER CAPE VALUES IN THE
800-1000 J/KG REGION. LOWER LEVEL SHEAR IS PRETTY MARGINAL...THOUGH
FORECAST SOUNDINGS DO SHOW A SIGNAL OF CURL TO THE HODOGRAPH. SPC
SREF ANALYSIS INDICATES EFFECTIVE SHEAR TO BE IN THE 30-35-40 KT
REALM FROM THE 18 TO TO 00Z HOUR FROM CMI TO IKK AND FLIRTING WITH
ORD /THOUGH REACHING 40KT MAY BE A STRETCH/...THEN IN THE 00Z TO
06Z HOURS SHIFTING EAST AND ACROSS NORTHERN INDIANA. PREVIOUS OFF
HOUR RUNS OF THE NAM AND GFS ALSO INDICATE A LITTLE SPEED MAX
RIPPLING THROUGH...WITH THE FAVORED ENTRANCE REGION MOVING
OVERHEAD INTO THE AFTERNOON HOURS. THAT HAS NOW SHIFTED A LITTLE
EAST...AND WHILE IT ISNT EXACTLY THE MOST FAVORABLE SETUP FOR
CONVECTION...CANT RULE OUT MORE THAN RAIN AND WILL ADD THE MENTION
OF THUNDER THROUGH THE AFTERNOON HOURS. THE BIGGEST THREAT WITH
THE COOLING ALOFT AND THE INCREASED LAPSE RATES WILL BE MARGINAL
HAIL...BUT CAN FORESEE SOME STORMS THAT POP THIS AFTERNOON TAKING
ON SIMILAR CHARACTERISTICS TO WHAT WAS OBSERVED IN THE LATE
EVENING ON THURSDAY...WHERE A FEW MULTICELLULAR CLUSTERS SHOW
SOME MID LEVEL ROTATION...AND THAT MAY GET CLOSE TO THE SURFACE.
BUT THE THREAT APPEARS LOW AND WILL BE MORE FOCUSED ON THE HAIL
THREAT...ESPECIALLY WITH THE LACK OF LOWER LEVEL SHEAR.
THE STREAK OF RECORD BREAKING TEMPERATURES AT ORD LOOKS TO FINALLY
BE OVER...AS THE RECORD HIGH FOR THE DATE IS 80 DEGREES. THE SURFACE
GRADIENT IS INCREDIBLY BAGGY THIS MORNING AND FLOW IS GENERALLY SSE
TO SE ACROSS THE REGION. AS THE SURFACE LOW TRACKS EAST ACROSS
SOUTHERN ILLINOIS...WINDS WILL BECOME MORE EASTERLY AND AREAS ALONG
THE LAKEFRONT WILL BE UNDER THE INFLUENCE OF THE COOLER
MARINE AIRMASS...AND THAT WILL HELP TO KEEP THE TEMPERATURES
CONSIDERABLY LOWER THAN HAS BEEN FELT THE PAST WEEK...GENERALLY
PEAKING IN THE MID/UPPER 60S. AN INTERESTING NOTE...EVEN WITH FLOW
OFF OF THE LAKE IN MID MARCH...DOWN TOWN CHICAGO WAS AT 54 DEGREES
AS OF 4AM. LAST YEAR LAKE MICHIGAN TEMPERATURES WERE 42 AT THE
SHORE...39 AT THE CRIB AND 38 AT MICHIGAN CITY INTAKE. THIS
YEAR...THEY ARE 49, 46 AND 44 RESPECTIVELY. THAT GOES TO HIGHLIGHT
HOW BIG OF A PLAYER THE LAKE CONTINUES TO PLAY IN TEMPERATURES.
WHILE IT WILL BE COOLER THAN WHAT HAS FELT LIKE THE NEW NORM...IT
WILL STILL BE ABOVE THE OFFICIAL NORMAL...WHICH IS 49 DEGREES.
GRANTED...IF AREAS WEST DO CLEAR OUT FOR LONGER THAN
ANTICIPATED...THEY WILL WARM CONSIDERABLY MORE THAN AREAS TO THE
EAST...BUT STILL NOT ANTICIPATING ANY RECORDS FOR THE DAY /AS
ROCKFORD/S RECORD FOR TODAY IS 82/. CIN BUILDS INTO THE EVENING AS
UPPER FLOW BACKS TO THE NORTHWEST AND THEN NORTH...AS THE DISH POT
LOW WOBBLES/MEANDERS EAST. CHANCE OF SHOWERS TO PERSIST THROUGH
THE DAY ON SATURDAY WITH DEEP CYCLONIC FLOW...THOUGH THE BETTERS
CHANCES WILL BE CLOSER TO THE LOW AND SOUTH ACROSS CENTRAL
ILLINOIS AND WEST CENTRAL INDIANA.
LONG TERM TRENDS STILL INDICATE BIGGER COOL DOWN SUNDAY NIGHT AND
INTO MONDAY. THE DISH POT WILL BE IN THE VICINITY OF THE LOWER
OHIO VALLEY BY THE END OF THE WEEKEND...TURNING ALL FLOW TO THE
NORTH AND NORTHWEST IN THAT TIME FRAME. THE GOOD NEWS IS THAT ANY
STRONG ADVECTION OF COLDER AIR THAT THE SYSTEM MAY HAVE HAD A WEEK
OR SO AGO WHEN IT WAS RAMPING UP...HAS BUT WASHED ITSELF OUT THIS
PAST WEEK. H8 TEMPS ARE PROGGED TO ONLY DIP INTO THE +6 TO +8
REALM WHICH MEANS THAT HIGHS ONLY EXPECTED IN THE LOWER 50S NORTH
OF I-88...TOUCHING 60 WELL SOUTH AND CLOSER TOWARDS ILX/S AREA OF
RESPONSIBILITY.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SHRA/TSRA OVER/NEAR THE TERMINALS NEXT 1-2 HRS...MORE
ISOLD/SCATTERED ACTIVITY POSSIBLE REMAINDER OF AFTERNOON/EARLY
EVENING.
* BRIEF IFR POSSIBLE WITH SHRA/TSRA THAT PASS OVERHEAD.
* PRIMARILY VFR CIGS ARRIVING WITH PATCHY MVFR REMAINING INTO
EARLY EVENING.
* MVFR VSBY MAY CONTINUE AT ORD WITH FLOW OFF LAKE MICHIGAN.
* EAST TO NORTHEAST WINDS EXPECTED TO CONTINUE THROUGH THE
AFTERNOON POTENTIALLY BECOMING EAST-SOUTHEAST YET THIS AFTERNOON
BEFORE BECOMING LIGHT AND VARIABLE. MDW SHOULD HAVE THE MOST
VARIABILITY.
* ANOTHER ROUND OF SHRA/TSRA POSSIBLE THIS EVENING BUT MAY REMAIN
JUST TO THE SOUTH.
* DECENT POTENTIAL FOR DENSE FOG DEVELOPMENT OVERNIGHT THROUGH
DAYBREAK SATURDAY.
* IFR IMPROVING TO VFR SATURDAY MORNING AND POSSIBLY VFR SATURDAY
AFTERNOON.
MDB
//DISCUSSION...UPDATED 20Z...
BULK OF THE SHRA/TSRA ACTIVITY NOW SKIRTING ORD/MDW/DPA TO THE
NORTHEAST AND SHOULD CONTINUE TO LIFT AWAY FROM THE
TERMINALS...INCLUDING GYY...OVER THE NEXT HOUR OR SO. PREVAILING
CIGS ARE QUICKLY IMPROVING TO VFR AND THIS TREND SHOULD REMAIN
INTO THE EVENING AND TAF CIGS MAY BE TOO PESSIMISTIC. CONVECTION
MOVING NORTHWARD ACROSS CENTRAL ILLINOIS WILL MAKE A RUN TOWARD
THE TERMINALS THIS EVENING BUT IT IS NOT YET CLEAR AS TO HOW
ORGANIZED OR WELL DEVELOPED THEY WILL BE AS THEY APPROACH...BUT WILL
CONTINUE TO MONITOR. TS MAY NEED TO BE ADDED FOR THE EVENING.
WINDS REMAIN VARIABLE WITH SHRA/TSRA STARTING TO IMPACT THE FLOW.
EXPECT MAINLY AN EASTERLY DIRECTION WITH FLUCTUATIONS TO NORTHEAST
AND SOUTHEAST. CONDS AT RFD HAVE BEEN MORE STEADY STATE WITH MOST
SHRA/TSRA ACTIVITY TO THE NORTH AND VFR PREVAILING...BUT WINDS
HAVE BEEN MORE VARIABLE BETWEEN SOUTH AND EAST.
FROM 18Z...
UPPER LOW CONTINUES TO SPIN OVER SOUTHERN MISSOURI RESULTING IN
LOW CIGS/VSBY AND SHRA/TSRA. CONDITIONS HIGHLY VARIABLE ACROSS THE
TERMINALS WITH THE WORST CONDITIONS ACROSS THE CHICAGO METRO AND
NORTHWEST INDIANA. A BAND OF THUNDERSTORMS HAS DEVELOPED OVER THE
LAST HOUR OR SO FROM ORD SOUTHWARD AND IS LIFTING NORTH. THE BULK
OF THIS ACTIVITY WILL LIFT TO THE NORTH OF THE CHI AREA TERMINALS
IN THE NEXT FEW HOURS WITH ADDITIONAL ACTIVITY POSSIBLE THROUGH
LATE AFTERNOON BUT APPEARING TO BE MUCH LESS ORGANIZED. IFR/MVFR
CIGS CONTINUE IN THIS SAME AREA AND IFR CIGS SHOULD IMPROVE TO LOW
END MVFR OVER THE NEXT HOUR OR SO.
MVFR CIGS WILL LIKELY PERSIST THROUGH THE AFTERNOON AT
DPA/ORD/MDW/GYY WHILE VFR CONTINUES AT RFD. THERE MAY BE SOME
IMPROVEMENT TO VFR LATE THIS AFTERNOON AND EARLY THIS EVENING BUT
THIS IS NOT YET CLEAR. VARIABLE EAST TO NORTHEAST WINDS WILL
CONTINUE AT ORD/MDW/DPA WITH GYY EXPECTED TO FLIP TO EAST OR
NORTHEAST SOMETIME LATER THIS AFTERNOON BUT SHOWER ACTIVITY MAY
KEEP THIS FROM OCCURRING.
ANOTHER ROUND OF CONVECTION SHOULD MOVE NORTHWARD ACROSS CENTRAL
ILLINOIS LATE THIS AFTERNOON. THE BIG QUESTION WILL BE HOW FAR
NORTH THIS WILL BE ABLE TO MOVE. WILL LIMIT PRECIP/TS MENTION IN
THE TAF FOR THIS EVENING BUT WILL NEED TO MONITOR CLOSELY. RIGHT
NOW BEST TIME FRAME FOR THIS WOULD BE MID OR LATE EVENING. LOW
LEVEL FLOW WILL BECOME LIGHT AND VARIABLE OVERNIGHT WHICH WILL
COMBINE WITH MOIST/SATURATED GROUND TO SUPPORT GOOD POTENTIAL FOR
FOG DEVELOPMENT. NOT CLEAR HOW LOW VSBY WILL GO BUT 1/2SM OR LESS
IS PLAUSIBLE...ESPECIALLY AT DPA/RFD. LESS CONFIDENCE IN VSBY THIS
OCCURRING AT ORD/MDW AND EVEN GYY BUT SOME FORM OF IFR VSBY
APPEARS LIKELY. NORTH-NORTHEAST FLOW WILL BE IN PLACE SATURDAY AS
THE UPPER LOW STARTS TO SHIFT EASTWARD AND IFR SHOULD IMPROVE TO
MVFR SOMETIME LATER SATURDAY MORNING...WITH VFR POSSIBLE SOMETIME
SATURDAY AFTERNOON.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN MOST WIDESPREAD SHRA/TSRA ACTIVITY LIFTING
NORTH OF THE TERMINALS NEXT HOUR OR SO. LOW-MEDIUM CONFIDENCE IN
SCATTERED/ISOLD POTENTIAL THROUGH EARLY EVENING.
* MEDIUM-HIGH CONFIDENCE IN BRIEF IFR OCCURRING WITH ANY PASSING
SHRA/TSRA.
* MEDIUM-HIGH CONFIDENCE IN PREVAILING CIGS IMPROVING TO VFR AND
CONTINUING INTO MID EVENING.
* HIGH CONFIDENCE IN GENERAL EAST TO NORTHEAST WIND DIRECTION WITH
VARIABILITY BUT MEDIUM CONFIDENCE IN TIMING OF MORE EAST-
SOUTHEAST DIRECTION THIS EVENING.
* LOW CONFIDENCE IN POTENTIAL FOR ANOTHER ROUND OF SHRA/TSRA
EARLY/MID EVENING BUT THIS MAY STAY JUST TO THE SOUTH.
* MEDIUM-HIGH CONFIDENCE IN IFR FOG DEVELOPMENT TONIGHT THROUGH
MID SATURDAY MORNING WITH LOW-MEDIUM CONFIDENCE IN HOW LOW VSBY
WILL BE.
* MEDIUM CONFIDENCE IN IFR IMPROVING TO VFR THROUGH SATURDAY BUT
LOW CONFIDENCE ON TIMING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...VFR. PSBL FG DEVELOPMENT.
SUNDAY...VFR.
MONDAY...VFR.
TUESDAY...VFR. PSBL MVFR CIGS WITH CHC SHRA/ISO TS.
WEDNESDAY...MVFR EARLY TRENDING VFR. CHC RA/TS EARLY.
THURSDAY...VFR.
BEACHLER
&&
.MARINE...
251 AM CDT
A COUPLE WEATHER FEATURES CONTINUE TO POSE CHALLENGES TO THE
WEATHER ACROSS THE MARINE COMMUNITY...AS AN UPPER LEVEL
DISTURBANCE SLOWLY LIFTS NORTHEAST FROM THE CENTRAL PLAINS TOWARDS
THE SOUTHERN GREAT LAKES TODAY. MEANWHILE A BROAD AREA OF HIGH
PRESSURE OVER NORTHERN MANITOBA WILL DRIFT EAST AND BECOME
CENTERED OVER HUDSON BAY TONIGHT INTO SATURDAY. THIS WILL ALLOW A
GRADIENT TO STEADILY INCREASE ACROSS THE NORTHERN PORTIONS OF THE
LAKE TODAY...WITH WINDS COMING UP TO 15 TO 25 KT. A FEW GUSTS UP
TO 30 KT WILL BE POSSIBLE. ELSEWHERE WITH THE LACK OF A STRONG
GRADIENT...WINDS WILL BE MUCH LIGHTER FROM THE EAST. THIS WILL
ALLOW WAVES TO BE HIGHER ALONG THE WESTERN SIDE OF LAKE MICHIGAN.
AT THIS TIME IT DOES NOT APPEAR WAVES WILL BE LARGE ENOUGH TO
WARRANT ANY HEADLINES IN THE NEARSHORE WATERS FOR
ILLINOIS/NORTHWEST INDIANA. THEN AS THE UPPER LEVEL DISTURBANCE
DRIFTS EAST...A WEAK LOW PRESSURE SYSTEM WILL TRAVERSE LAKE
SUPERIOR. BEHIND THIS SYSTEM ON SUNDAY...A STRONG HIGH PRESSURE
WILL BUILD IN AND TIGHTEN THE GRADIENT YET AGAIN. THIS SHOULD
ALLOW WINDS TO STEADILY INCREASE.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
130 PM CDT FRI MAR 23 2012
.MESOSCALE DISCUSSION...
1200 PM CDT
A SWATH OF SHOWERS FROM SOUTHEAST WISCONSIN THROUGH NORTHWEST
INDIANA CONTINUE TO MOVE NORTHEAST. BASED ON THE LATEST RUC
ANALYSIS...THE SLOW MOVING UPPER LEVEL LOW IS CURRENTLY CENTERED
OVER MISSOURI. THE CORRESPONDING SURFACE LOW IS OVER EAST CENTRAL
MISSOURI AND SLOWLY MOVING INTO SOUTHERN INDIANA. LATEST WATER
VAPOR IMAGERY SHOWS SPIRALS OF DRIER AIR CIRCLING THE UPPER LEVEL
LOW...WHICH CORRELATE TO AREAS OF CLEARING OVER NORTH CENTRAL
ILLINOIS.
UNDER THE AREAS OF CLEARING...LOW LEVEL LAPSE RATES HAVE BEEN
RAPIDLY INCREASING. THE RUC HAS A GOOD HANDLE ON MID LEVEL LAPSE
RATES...AND INDICATES STEEPER MID LEVEL LAPSE RATES WILL BE
ADVECTED FROM CENTRAL ILLINOIS THROUGH NORTHERN ILLINOIS. AN AREA
OF CONVERGENCE IS ALSO VISIBLE IN THE SURFACE WIND OBS ALONG THE
ILLINOIS INDIANA STATE LINE. THE STEEP LOW LEVEL LAPSE RATES AND
AREA OF CONVERGENCE HAVE RESULTED IN CONVECTIVE SHOWERS DEVELOPING
ACROSS THE SOUTHERN HALF OF THE CWA. A FEW LIGHTNING STRIKES HAVE
BEEN DETECTED...BUT GIVEN THE ENVIRONMENT...EXPECTING AN INCREASE
IN CONVECTION THROUGH THE AFTERNOON.
CONCERNING THE SEVERE THREAT...THERE IS ADEQUATE
MOISTURE...FORCING...AND SHEAR FOR SEVERE THUNDERSTORM
DEVELOPMENT. HOWEVER INSTABILITY APPEARS TO BE WEAK TO MODERATE AT
BEST. CURRENTLY...THERE IS NO SIGNIFICANT SURFACE BASED CAPE TO
SPEAK OF. RUC AND HRR ANALYSES INDICATE A MAX OF 1500 J/KG THIS
AFTERNOON...WHILE THE SREF HINTS AT A BRIEF MAX OF AT LEAST 500
J/KG. BOTH THE RUC AND HRR SEEM A BIT AMBITIOUS WITH CAPE VALUES
THIS AFTERNOON...THEREFORE EXPECTING ABOUT 1000 J/KG TO WORK WITH.
IF INSTABILITY INCREASES...THE LIKELIHOOD OF MORE WIDESPREAD
SEVERE WEATHER WOULD ALSO INCREASE.
THE MAIN SEVERE WEATHER THREATS ARE HAIL AND DAMAGING WINDS. NAM
MODEL SOUNDINGS ARE ON TREND WITH CURRENT CONDITIONS AND SHOW A
DECENT INVERTED V FEATURE IN DOWNSTATE ILLINOIS THIS
AFTERNOON...WHICH WOULD INDICATE A GOOD CHANCE FOR STRONG
DOWNDRAFTS AND DAMAGING WINDS. MIDLAYER SHEAR IS PLENTIFUL SINCE
WE ARE ON THE NORTHEAST SIDE OF THE UPPER LEVEL LOW. LATEST RUC
ANALYSIS SHOWS UPWARDS OF 60 KT OF 0-6KM SHEAR THROUGH NORTHEAST
ILLINOIS AND NORTHWEST INDIANA. GIVEN A STRONG ENOUGH UPDRAFT AND
STRONG SHEAR...SEVERE HAIL IS POSSIBLE. HOWEVER WITH THE DRY LOW
LEVELS AND THE 12Z ILX SOUNDING INDICATING A FREEZING LEVEL
BETWEEN 9-10 KFT...ONLY EXPECTING HAIL UP TO QUARTER SIZE AT THIS
TIME. AN AREA OF ENHANCED LOW LEVEL HELICITY IS SHIFTING
NORTHWARD AND THIS COULD LEAD TO A FEW ROTATING UPDRAFTS AND
POSSIBLY AN ISOLATED TORNADO OR TWO.
JEE
&&
.DISCUSSION...
340 AM CDT
LARGE UPPER LOW ACROSS THE CENTRAL CONUS IS TAKING ITS TIME SWEET
MOVING TO THE EAST-NORTHEAST. AS THIS FEATURE CONTINUES ITS TREK
INTO THE OHIO VALLEY THROUGH THE WEEKEND...IT WILL BRING SHOWERS
WITH SOME THUNDER TO THE AREA...AS WELL AS CONTINUE TO KEEP THE
ABOVE NORMAL TEMPERATURES THROUGH THE WEEKEND. OVERNIGHT SUNDAY
AND INTO THE START OF THE WORKWEEK WILL SEE CONDITIONS
CHANGE...WITH TEMPERATURES FALLING A LITTLE CLOSER TO NORMAL...BUT
DRY.
DRY SLOT NOTED ON WATER VAPOR IMAGERY THIS MORNING WILL CONTINUE TO
CURL NORTH ACROSS THE CWA THIS MORNING AND WILL LEAD TO SOME DRYING
COME THE MORNING HOURS...AND OVERALL SHOWERY CONDITIONS WILL BE ON
THE WANE FOR MOST. AREAS ACROSS THE WEST AND SOUTH MAY ALSO HAVE THE
BETTER CHANCES AT SEEING SOME HINTS OF SUN...BUT THAT WILL BE SHORT
LIVED AS CHANCES FOR SHOWERS AND THUNDER INCREASE INTO THE AFTERNOON.
ONE OF THE BIGGER CHANGES TO THE GOING FORECAST IS WITH RESPECT TO
THE MASSIVE AND PERSISTENT STACKED LOW THAT IS SLOWLY MOVING ACROSS
THE CENTRAL US. THE CHANGE TONIGHT IS THAT THE LOW IS NOW PROGGED TO
MOVE A LITTLE FARTHER NORTH THAN EARLIER ANTICIPATED. BY BRINGING
THE CORE A LITTLE FARTHER NORTH...WE ARE NOW GOING TO INTRODUCE A
LITTLE COOLER AIR ALOFT BY THE AFTERNOON HOURS. SURFACE DEWPOINTS IN
THE UPPER 50S TO LOWER 60S TO CONTINUE INTO THE AFTERNOON
HOURS...AND WILL HELP TO SUPPORT MEAN LAYER CAPE VALUES IN THE
800-1000 J/KG REGION. LOWER LEVEL SHEAR IS PRETTY MARGINAL...THOUGH
FORECAST SOUNDINGS DO SHOW A SIGNAL OF CURL TO THE HODOGRAPH. SPC
SREF ANALYSIS INDICATES EFFECTIVE SHEAR TO BE IN THE 30-35-40 KT
REALM FROM THE 18 TO TO 00Z HOUR FROM CMI TO IKK AND FLIRTING WITH
ORD /THOUGH REACHING 40KT MAY BE A STRETCH/...THEN IN THE 00Z TO
06Z HOURS SHIFTING EAST AND ACROSS NORTHERN INDIANA. PREVIOUS OFF
HOUR RUNS OF THE NAM AND GFS ALSO INDICATE A LITTLE SPEED MAX
RIPPLING THROUGH...WITH THE FAVORED ENTRANCE REGION MOVING
OVERHEAD INTO THE AFTERNOON HOURS. THAT HAS NOW SHIFTED A LITTLE
EAST...AND WHILE IT ISNT EXACTLY THE MOST FAVORABLE SETUP FOR
CONVECTION...CANT RULE OUT MORE THAN RAIN AND WILL ADD THE MENTION
OF THUNDER THROUGH THE AFTERNOON HOURS. THE BIGGEST THREAT WITH
THE COOLING ALOFT AND THE INCREASED LAPSE RATES WILL BE MARGINAL
HAIL...BUT CAN FORESEE SOME STORMS THAT POP THIS AFTERNOON TAKING
ON SIMILAR CHARACTERISTICS TO WHAT WAS OBSERVED IN THE LATE
EVENING ON THURSDAY...WHERE A FEW MULTICELLULAR CLUSTERS SHOW
SOME MID LEVEL ROTATION...AND THAT MAY GET CLOSE TO THE SURFACE.
BUT THE THREAT APPEARS LOW AND WILL BE MORE FOCUSED ON THE HAIL
THREAT...ESPECIALLY WITH THE LACK OF LOWER LEVEL SHEAR.
THE STREAK OF RECORD BREAKING TEMPERATURES AT ORD LOOKS TO FINALLY
BE OVER...AS THE RECORD HIGH FOR THE DATE IS 80 DEGREES. THE SURFACE
GRADIENT IS INCREDIBLY BAGGY THIS MORNING AND FLOW IS GENERALLY SSE
TO SE ACROSS THE REGION. AS THE SURFACE LOW TRACKS EAST ACROSS
SOUTHERN ILLINOIS...WINDS WILL BECOME MORE EASTERLY AND AREAS ALONG
THE LAKEFRONT WILL BE UNDER THE INFLUENCE OF THE COOLER
MARINE AIRMASS...AND THAT WILL HELP TO KEEP THE TEMPERATURES
CONSIDERABLY LOWER THAN HAS BEEN FELT THE PAST WEEK...GENERALLY
PEAKING IN THE MID/UPPER 60S. AN INTERESTING NOTE...EVEN WITH FLOW
OFF OF THE LAKE IN MID MARCH...DOWN TOWN CHICAGO WAS AT 54 DEGREES
AS OF 4AM. LAST YEAR LAKE MICHIGAN TEMPERATURES WERE 42 AT THE
SHORE...39 AT THE CRIB AND 38 AT MICHIGAN CITY INTAKE. THIS
YEAR...THEY ARE 49, 46 AND 44 RESPECTIVELY. THAT GOES TO HIGHLIGHT
HOW BIG OF A PLAYER THE LAKE CONTINUES TO PLAY IN TEMPERATURES.
WHILE IT WILL BE COOLER THAN WHAT HAS FELT LIKE THE NEW NORM...IT
WILL STILL BE ABOVE THE OFFICIAL NORMAL...WHICH IS 49 DEGREES.
GRANTED...IF AREAS WEST DO CLEAR OUT FOR LONGER THAN
ANTICIPATED...THEY WILL WARM CONSIDERABLY MORE THAN AREAS TO THE
EAST...BUT STILL NOT ANTICIPATING ANY RECORDS FOR THE DAY /AS
ROCKFORD/S RECORD FOR TODAY IS 82/. CIN BUILDS INTO THE EVENING AS
UPPER FLOW BACKS TO THE NORTHWEST AND THEN NORTH...AS THE DISH POT
LOW WOBBLES/MEANDERS EAST. CHANCE OF SHOWERS TO PERSIST THROUGH
THE DAY ON SATURDAY WITH DEEP CYCLONIC FLOW...THOUGH THE BETTERS
CHANCES WILL BE CLOSER TO THE LOW AND SOUTH ACROSS CENTRAL
ILLINOIS AND WEST CENTRAL INDIANA.
LONG TERM TRENDS STILL INDICATE BIGGER COOL DOWN SUNDAY NIGHT AND
INTO MONDAY. THE DISH POT WILL BE IN THE VICINITY OF THE LOWER
OHIO VALLEY BY THE END OF THE WEEKEND...TURNING ALL FLOW TO THE
NORTH AND NORTHWEST IN THAT TIME FRAME. THE GOOD NEWS IS THAT ANY
STRONG ADVECTION OF COLDER AIR THAT THE SYSTEM MAY HAVE HAD A WEEK
OR SO AGO WHEN IT WAS RAMPING UP...HAS BUT WASHED ITSELF OUT THIS
PAST WEEK. H8 TEMPS ARE PROGGED TO ONLY DIP INTO THE +6 TO +8
REALM WHICH MEANS THAT HIGHS ONLY EXPECTED IN THE LOWER 50S NORTH
OF I-88...TOUCHING 60 WELL SOUTH AND CLOSER TOWARDS ILX/S AREA OF
RESPONSIBILITY.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SHRA/TSRA AFFECTING THE TERMINALS EARLY THIS AFTERNOON.
* PERIODIC IFR VSBY IN SHRA/TSRA NEXT FEW HOURS.
* IFR CIGS EXPECTED TO SCATTER NEXT FEW HOURS...WITH MVFR INTO
LATE AFTERNOON.
* EAST TO NORTHEAST WINDS EXPECTED TO CONTINUE THROUGH THE
AFTERNOON POTENTIALLY BECOMING EAST-SOUTHEAST EARLY THIS
AFTERNOON BEFORE BECOMING LIGHT AND VARIABLE.
* ANOTHER ROUND OF SHRA/TSRA POSSIBLE THIS EVENING BUT MAY REMAIN
JUST TO THE SOUTH.
* DECENT POTENTIAL FOR DENSE FOG DEVELOPMENT OVERNIGHT THROUGH
DAYBREAK SATURDAY.
* IFR IMPROVING TO VFR SATURDAY MORNING AND POSSIBLY VFR SATURDAY
AFTERNOON.
MDB
//DISCUSSION...UPDATED 18Z...
UPPER LOW CONTINUES TO SPIN OVER SOUTHERN MISSOURI RESULTING IN
LOW CIGS/VSBY AND SHRA/TSRA. CONDITIONS HIGHLY VARIABLE ACROSS THE
TERMINALS WITH THE WORST CONDITIONS ACROSS THE CHICAGO METRO AND
NORTHWEST INDIANA. A BAND OF THUNDERSTORMS HAS DEVELOPED OVER THE
LAST HOUR OR SO FROM ORD SOUTHWARD AND IS LIFTING NORTH. THE BULK
OF THIS ACTIVITY WILL LIFT TO THE NORTH OF THE CHI AREA TERMINALS
IN THE NEXT FEW HOURS WITH ADDITIONAL ACTIVITY POSSIBLE THROUGH
LATE AFTERNOON BUT APPEARING TO BE MUCH LESS ORGANIZED. IFR/MVFR
CIGS CONTINUE IN THIS SAME AREA AND IFR CIGS SHOULD IMPROVE TO LOW
END MVFR OVER THE NEXT HOUR OR SO.
MVFR CIGS WILL LIKELY PERSIST THROUGH THE AFTERNOON AT
DPA/ORD/MDW/GYY WHILE VFR CONTINUES AT RFD. THERE MAY BE SOME
IMPROVEMENT TO VFR LATE THIS AFTERNOON AND EARLY THIS EVENING BUT
THIS IS NOT YET CLEAR. VARIABLE EAST TO NORTHEAST WINDS WILL
CONTINUE AT ORD/MDW/DPA WITH GYY EXPECTED TO FLIP TO EAST OR
NORTHEAST SOMETIME LATER THIS AFTERNOON BUT SHOWER ACTIVITY MAY
KEEP THIS FROM OCCURRING.
ANOTHER ROUND OF CONVECTION SHOULD MOVE NORTHWARD ACROSS CENTRAL
ILLINOIS LATE THIS AFTERNOON. THE BIG QUESTION WILL BE HOW FAR
NORTH THIS WILL BE ABLE TO MOVE. WILL LIMIT PRECIP/TS MENTION IN
THE TAF FOR THIS EVENING BUT WILL NEED TO MONITOR CLOSELY. RIGHT
NOW BEST TIME FRAME FOR THIS WOULD BE MID OR LATE EVENING. LOW
LEVEL FLOW WILL BECOME LIGHT AND VARIABLE OVERNIGHT WHICH WILL
COMBINE WITH MOIST/SATURATED GROUND TO SUPPORT GOOD POTENTIAL FOR
FOG DEVELOPMENT. NOT CLEAR HOW LOW VSBY WILL GO BUT 1/2SM OR LESS
IS PLAUSIBLE...ESPECIALLY AT DPA/RFD. LESS CONFIDENCE IN VSBY THIS
OCCURRING AT ORD/MDW AND EVEN GYY BUT SOME FORM OF IFR VSBY
APPEARS LIKELY. NORTH-NORTHEAST FLOW WILL BE IN PLACE SATURDAY AS
THE UPPER LOW STARTS TO SHIFT EASTWARD AND IFR SHOULD IMPROVE TO
MVFR SOMETIME LATER SATURDAY MORNING...WITH VFR POSSIBLE SOMETIME
SATURDAY AFTERNOON.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN SHRA/TSRA MOVING ACROSS NEXT FEW HOURS.
* MEDIUM-HIGH CONFIDENCE IN PERIODIC IFR VSBY IN SHRA/TSRA.
* HIGH CONFIDENCE IN IFR CIGS CONTINUING NEXT HOUR OR SO BUT LOW
CONFIDENCE ON HOW LONG IT WILL TAKE TO SCATTER.
* HIGH CONFIDENCE IN GENERAL EAST TO NORTHEAST WIND DIRECTION WITH
VARIABILITY BUT MEDIUM CONFIDENCE IN TIMING OF MORE EAST-
SOUTHEAST DIRECTION.
* LOW CONFIDENCE IN POTENTIAL FOR ANOTHER ROUND OF SHRA/TSRA
EARLY/MID EVENING BUT THIS MAY STAY JUST TO THE SOUTH.
* MEDIUM-HIGH CONFIDENCE IN IFR FOG DEVELOPMENT TONIGHT THROUGH
MID SATURDAY MORNING WITH LOW-MEDIUM CONFIDENCE IN HOW LOW VSBY
WILL BE.
* MEDIUM CONFIDENCE IN IFR IMPROVING TO VFR THROUGH SATURDAY BUT
LOW CONFIDENCE ON TIMING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...VFR. PSBL FG DEVELOPMENT.
SUNDAY...VFR.
MONDAY...VFR.
TUESDAY...VFR. PSBL MVFR CIGS WITH CHC SHRA/ISO TS.
WEDNESDAY...MVFR EARLY TRENDING VFR. CHC RA/TS EARLY.
THURSDAY...VFR.
BEACHLER
&&
.MARINE...
251 AM CDT
A COUPLE WEATHER FEATURES CONTINUE TO POSE CHALLENGES TO THE
WEATHER ACROSS THE MARINE COMMUNITY...AS AN UPPER LEVEL
DISTURBANCE SLOWLY LIFTS NORTHEAST FROM THE CENTRAL PLAINS TOWARDS
THE SOUTHERN GREAT LAKES TODAY. MEANWHILE A BROAD AREA OF HIGH
PRESSURE OVER NORTHERN MANITOBA WILL DRIFT EAST AND BECOME
CENTERED OVER HUDSON BAY TONIGHT INTO SATURDAY. THIS WILL ALLOW A
GRADIENT TO STEADILY INCREASE ACROSS THE NORTHERN PORTIONS OF THE
LAKE TODAY...WITH WINDS COMING UP TO 15 TO 25 KT. A FEW GUSTS UP
TO 30 KT WILL BE POSSIBLE. ELSEWHERE WITH THE LACK OF A STRONG
GRADIENT...WINDS WILL BE MUCH LIGHTER FROM THE EAST. THIS WILL
ALLOW WAVES TO BE HIGHER ALONG THE WESTERN SIDE OF LAKE MICHIGAN.
AT THIS TIME IT DOES NOT APPEAR WAVES WILL BE LARGE ENOUGH TO
WARRANT ANY HEADLINES IN THE NEARSHORE WATERS FOR
ILLINOIS/NORTHWEST INDIANA. THEN AS THE UPPER LEVEL DISTURBANCE
DRIFTS EAST...A WEAK LOW PRESSURE SYSTEM WILL TRAVERSE LAKE
SUPERIOR. BEHIND THIS SYSTEM ON SUNDAY...A STRONG HIGH PRESSURE
WILL BUILD IN AND TIGHTEN THE GRADIENT YET AGAIN. THIS SHOULD
ALLOW WINDS TO STEADILY INCREASE.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1257 PM CDT FRI MAR 23 2012
.DISCUSSION...
ISSUED 1005 AM CDT FRI MAR 23 2012
LARGE STACKED LOW SPINNING OVER THE SOUTHEAST TIP OF KANSAS PER
WATER VAPOR IMAGERY...WITH SURFACE OBS AND RADAR IMAGERY SHOWING A
SECONDARY LOW PRESSURE AREA OVER CENTRAL MISSOURI. HAD QUITE A BIT
OF FOG DEVELOP OVER THE WESTERN 2/3 OF THE CWA EARLIER...BUT
VISIBILITIES WERE RAPIDLY IMPROVING BY 9 AM AND LATEST
OBSERVATIONS SHOWING MOST SITES ABOVE 4 MILES THIS HOUR. HAVE BEEN
SEEING A RAPID INCREASE IN SHOWERS AND STORMS OVER SOUTHEAST
MISSOURI RECENTLY...WITH A FEW SHOWERS/STORMS NOW MOVING INTO FAR
SOUTHERN PARTS OF OUR CWA. 12Z SOUNDING FROM SPRINGFIELD MO SHOWED
500 MB TEMPERATURES OF -26C ASSOCIATED WITH THE UPPER LOW...WHICH
WILL TRACK EASTWARD ACROSS SOUTHERN MISSOURI THIS AFTERNOON. THIS
WILL ENHANCE MID-LEVEL LAPSE RATES...WITH LATEST RUC MODEL SHOWING
RATES OF AROUND 7.5 TO 8C/KM OVER OUR AREA BY EARLY AFTERNOON
SUPPORTING HAIL DEVELOPMENT WITH THE STRONGER STORMS. SEVERE
WEATHER POTENTIAL STILL EXISTS BECAUSE OF THIS...WITH AREAS
SOUTHEAST OF I-55 MOST AT RISK.
UPDATED GRIDS HAVE BEEN SENT...WITH UPDATED ZONES TO FOLLOW AROUND
1015 AM. MOST CHANGES WERE IN THE PRECIP/WEATHER TYPES...WITH SOME
ADJUSTMENTS TO THE HOURLY GRIDS FOR OTHER ELEMENTS.
GEELHART
&&
.AVIATION...
ISSUED 1257 PM CDT FRI MAR 23 2012...FOR THE 12Z TAFS
SHOWERS ARE BEGINNING TO RETURN TO CENTRAL IL FROM THE SOUTH AS
INSTABILITY INCREASES AHEAD OF THE LOW PRESSURE SYSTEM. THE NEXT
BAND OF STORMS MAY CONTAIN HAIL...BUT THE SEVERE THUNDERSTORM
WATCH UNTIL 7 PM DOES NOT INCLUDE ANY OF THE TERMINAL SITES. WE
INCLUDED A 3 HOUR TEMPO FOR TSRAGS AT SPI/DEC/CMI THIS AFTERNOON
TO COVER THE HIGHER THREAT AREAS FOR SMALLER HAIL THAN 1 INCH. THE
MAIN WINDOW FOR HAIL LOOKS TO BE 20Z-23Z. MVFR CONDITIONS WILL BE
LIKELY DURING STORMS...WITH IFR POSSIBLE.
THERE MAY BE A BREAK BETWEEN LINES OF STORMS AFTER THAT 23Z-
00Z...BUT THAT TREND WILL BECOME BETTER DEFINED LATER THIS
AFTERNOON. WILL NOT ADD ADDITIONAL PERIODS OF STORMS FOR TONIGHT
JUST YET.
WINDS WILL BE VARIABLE AS THE LOW APPROACHES FROM SOUTHWEST
MISSOURI. THE LOW SHOULD MOVE ACROSS SOUTH CENTRAL IL...SO THE
PREVAILING WIND DIRECTION SHOULD BE SOUTHEAST UNTIL LATER
TONIGHT...WHEN THE WINDS SHIFT AROUND TO THE WEST.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT FRI MAR 23 2012
SHORT TERM...TODAY THROUGH MONDAY NIGHT
00Z MODELS REMAIN IN FAIR AGREEMENT THROUGH THIS WEEKEND AND WILL
USE A BLEND. MET AND MAV GUIDANCE TEMPS SIMILAR THROUGH THIS
WEEKEND AND STAYED CLOSE TOO. GUIDANCE CONTINUES TO GO WARMER ON
SUNDAY AND HAS HIGHS IN THE MID 70S MOST AREAS AND TRENDED THE
FORECAST IN THAT DIRECTION.
COOLER TEMPERATURES EXPECTED LATE THIS WEEK THOUGH STILL 10-15
DEGREES ABOVE NORMAL AND SUNDAY NOW LOOKS WARMER IN THE 70S.
UNSETTLED WEATHER PATTERN EXPECTED THROUGH SAT DUE TO 551 DM 500
MB LOW OVER SOUTHEAST KS THAT SLOWLY WEAKENS IT IT MOVES INTO SE
MO BY SUNSET AND THEN INTO SOUTH CENTRAL KY/MID TN BY SUNSET SAT.
SPC HAS MUCH OF CENTRAL/SE IL INTO THE LOWER OHIO VALLEY IN A
SLIGHT RISK THIS AFTERNOON FOR MAINLY LARGE HAIL (15%) RISK WHILE
WINDS AND ISOLATED TORNADOES ARE JUST 5% RISK.
SHOWERS AND ISOLATED THUNDERSTORMS OVER INDIANA AND NE IL DRIFTING
NNW AROUND THE 551 DM 500 MB LOW OVER SE KS. A SMALL BAND OF
SHOWERS AND A FEW THUNDERSTORMS OVER CENTRAL AND SOUTH CENTRAL MO
CLOSER TO THE UPPER LEVEL LOW. DRY WEDGE IN BETWEEN OVER CENTRAL
AND SW IL AND SOME CLEARING FROM LINCOLN SW HAS ALLOWED SOME FOG
TO FORM EARLY THIS MORNING...EVEN DENSE FOG AT MACOMB...KEOKUK AND
PITTSFIELD IN WEST CENTRAL IL. VSBYS GENERALLY 3-5 MILES WEST OF
LINCOLN AND MAY NEED TO ADD FOG TO THE FORECAST FOR THESE AREAS
INTO MID MORNING AND VSBYS LIKELY DROP FURTHER.
EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP BY MIDDAY
AND BECOME MORE WIDESPREAD DURING THE AFTERNOON AS UPPER LEVEL LOW
MOVES INTO SOUTHERN MO AND AIRMASS GETS MORE UNSTABLE AND HAVE
LIKELY TO EVEN CATEGORICAL POPS THIS AFTERNOON OVER SW AREAS. PER
SPC DAY1 OUTLOOK...BAND/ARC OF THUNDERSTORMS IS EXPECTED TO
INCREASE IN COVERAGE/INTENSITY FROM MIDDAY THROUGH AT LEAST MID
AFTERNOON...IN ZONE OF CONVERGENCE LOCATED NE-E OF DEEP- LAYER
LOW. COLD CORE CONVECTIVE REGIME FCST TO SHIFT EWD/NEWD ACROSS
OUTLOOK AREA...WITH DOMINANT THREAT BEING LARGE HAIL...ISOLATED
DAMAGING GUSTS POSSIBLE. TORNADO POTENTIAL APPEARS
CONDITIONAL/MARGINAL ON OUTLOOK SCALE ATTM...BUT MAY BE LOCALLY
ENHANCED BY STORM INTERACTIONS WITH BANNERS OF BOUNDARY- LAYER
VORTICITY. ENHANCED/7.5-8.5 DEG C/KM MID LEVEL LAPSE RATES AND MID
50S TO NEAR 60 F SFC DEW POINTS WILL JUXTAPOSE WITH SURFACE
HEATING TO SUPPORT 600-1200 J/KG MLCAPE...AMIDST 30-45 KT
EFFECTIVE SHEAR MAGNITUDES. THUNDERSTORMS SHOULD DIMINISH DURING
EARLY THIS EVENING WITH LOSS OF DAYTIME HEATING.
SHOWERS TO DIMINISH OVERNIGHT AND THEN INCREASE AGAIN BY SAT
AFTERNOON WITH ISOLATED THUNDERSTORMS POSSIBLE OVER EASTERN/SE IL
SAT AFTERNOON ESPECIALLY NEAR THE WABASH RIVER WHERE SHOWERS MAY
LINGER EARLY SAT EVENING BY LAWRENCEVILLE. UPPER LEVEL LOW SLOWLY
WEAKENS AS IT DRIFTS ESE INTO EASTERN TN BY MIDNIGHT SAT NIGHT.
NICE WEATHER EXPECTED EARLY NEXT WEEK WITH UPPER LEVEL LOW
PULLING AWAY INTO THE SE STATES AND STRONG UPPER LEVEL RIDGING
OVER THE GREAT PLAINS SHIFTING EASTWARD INTO THE MS VALLEY BY MON
NIGHT AND INTO IL TUE. 850 MB TEMPS WARM UP SUNDAY TO 10C OR
WARMER SW AREAS AND GIVES HIGHS IN THE LOW TO MID 70S. BACKDOOR
COLD FRONT TO MOVE FROM THE GREAT LAKES REGION THROUGH IL EARLY
NEXT WEEK...COOLING TEMPS MONDAY ESPECIALLY NE AREAS BUT DRY
CONDITIONS EXPECTED SUNDAY THROUGH TUE.
LONG TERM...TUESDAY THROUGH FRIDAY
A PROGRESSIVE NORTHERN STREAM WEATHER SYSTEM TRACKING EAST ALONG
THE US/CANADIAN BORDER TO PUSH A COLD FRONT THROUGH IL TUE NIGHT
AND THEN STALL OUT NEAR THE OHIO RIVER WED BEFORE LIFTING BACK
NORTH LATER NEXT WEEK. THIS TO BRING CHANCES OF
SHOWERS/THUNDERSTORMS BY TUE NIGHT AND MAINLY IN SE IL WED AND
THEN HAVE SLIGHT CHANCES OF CONVECTION LATE NEXT WORK WEEK WITH
FRONT LIFTING BACK NORTH. TEMPS OVERALL TO REMAIN ABOVE NORMAL AND
NO FROST OR FREEZE EXPECTED THROUGH NEXT WEEK.
HUETTL
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1256 PM CDT FRI MAR 23 2012
.MESOSCALE DISCUSSION...
1200 PM CDT
A SWATH OF SHOWERS FROM SOUTHEAST WISCONSIN THROUGH NORTHWEST
INDIANA CONTINUE TO MOVE NORTHEAST. BASED ON THE LATEST RUC
ANALYSIS...THE SLOW MOVING UPPER LEVEL LOW IS CURRENTLY CENTERED
OVER MISSOURI. THE CORRESPONDING SURFACE LOW IS OVER EAST CENTRAL
MISSOURI AND SLOWLY MOVING INTO SOUTHERN INDIANA. LATEST WATER
VAPOR IMAGERY SHOWS SPIRALS OF DRIER AIR CIRCLING THE UPPER LEVEL
LOW...WHICH CORRELATE TO AREAS OF CLEARING OVER NORTH CENTRAL
ILLINOIS.
UNDER THE AREAS OF CLEARING...LOW LEVEL LAPSE RATES HAVE BEEN
RAPIDLY INCREASING. THE RUC HAS A GOOD HANDLE ON MID LEVEL LAPSE
RATES...AND INDICATES STEEPER MID LEVEL LAPSE RATES WILL BE
ADVECTED FROM CENTRAL ILLINOIS THROUGH NORTHERN ILLINOIS. AN AREA
OF CONVERGENCE IS ALSO VISIBLE IN THE SURFACE WIND OBS ALONG THE
ILLINOIS INDIANA STATE LINE. THE STEEP LOW LEVEL LAPSE RATES AND
AREA OF CONVERGENCE HAVE RESULTED IN CONVECTIVE SHOWERS DEVELOPING
ACROSS THE SOUTHERN HALF OF THE CWA. A FEW LIGHTNING STRIKES HAVE
BEEN DETECTED...BUT GIVEN THE ENVIRONMENT...EXPECTING AN INCREASE
IN CONVECTION THROUGH THE AFTERNOON.
CONCERNING THE SEVERE THREAT...THERE IS ADEQUATE
MOISTURE...FORCING...AND SHEAR FOR SEVERE THUNDERSTORM
DEVELOPMENT. HOWEVER INSTABILITY APPEARS TO BE WEAK TO MODERATE AT
BEST. CURRENTLY...THERE IS NO SIGNIFICANT SURFACE BASED CAPE TO
SPEAK OF. RUC AND HRR ANALYSES INDICATE A MAX OF 1500 J/KG THIS
AFTERNOON...WHILE THE SREF HINTS AT A BRIEF MAX OF AT LEAST 500
J/KG. BOTH THE RUC AND HRR SEEM A BIT AMBITIOUS WITH CAPE VALUES
THIS AFTERNOON...THEREFORE EXPECTING ABOUT 1000 J/KG TO WORK WITH.
IF INSTABILITY INCREASES...THE LIKELIHOOD OF MORE WIDESPREAD
SEVERE WEATHER WOULD ALSO INCREASE.
THE MAIN SEVERE WEATHER THREATS ARE HAIL AND DAMAGING WINDS. NAM
MODEL SOUNDINGS ARE ON TREND WITH CURRENT CONDITIONS AND SHOW A
DECENT INVERTED V FEATURE IN DOWNSTATE ILLINOIS THIS
AFTERNOON...WHICH WOULD INDICATE A GOOD CHANCE FOR STRONG
DOWNDRAFTS AND DAMAGING WINDS. MIDLAYER SHEAR IS PLENTIFUL SINCE
WE ARE ON THE NORTHEAST SIDE OF THE UPPER LEVEL LOW. LATEST RUC
ANALYSIS SHOWS UPWARDS OF 60 KT OF 0-6KM SHEAR THROUGH NORTHEAST
ILLINOIS AND NORTHWEST INDIANA. GIVEN A STRONG ENOUGH UPDRAFT AND
STRONG SHEAR...SEVERE HAIL IS POSSIBLE. HOWEVER WITH THE DRY LOW
LEVELS AND THE 12Z ILX SOUNDING INDICATING A FREEZING LEVEL
BETWEEN 9-10 KFT...ONLY EXPECTING HAIL UP TO QUARTER SIZE AT THIS
TIME. AN AREA OF ENHANCED LOW LEVEL HELICITY IS SHIFTING
NORTHWARD AND THIS COULD LEAD TO A FEW ROTATING UPDRAFTS AND
POSSIBLY AN ISOLATED TORNADO OR TWO.
JEE
&&
.DISCUSSION...
340 AM CDT
LARGE UPPER LOW ACROSS THE CENTRAL CONUS IS TAKING ITS TIME SWEET
MOVING TO THE EAST-NORTHEAST. AS THIS FEATURE CONTINUES ITS TREK
INTO THE OHIO VALLEY THROUGH THE WEEKEND...IT WILL BRING SHOWERS
WITH SOME THUNDER TO THE AREA...AS WELL AS CONTINUE TO KEEP THE
ABOVE NORMAL TEMPERATURES THROUGH THE WEEKEND. OVERNIGHT SUNDAY
AND INTO THE START OF THE WORKWEEK WILL SEE CONDITIONS
CHANGE...WITH TEMPERATURES FALLING A LITTLE CLOSER TO NORMAL...BUT
DRY.
DRY SLOT NOTED ON WATER VAPOR IMAGERY THIS MORNING WILL CONTINUE TO
CURL NORTH ACROSS THE CWA THIS MORNING AND WILL LEAD TO SOME DRYING
COME THE MORNING HOURS...AND OVERALL SHOWERY CONDITIONS WILL BE ON
THE WANE FOR MOST. AREAS ACROSS THE WEST AND SOUTH MAY ALSO HAVE THE
BETTER CHANCES AT SEEING SOME HINTS OF SUN...BUT THAT WILL BE SHORT
LIVED AS CHANCES FOR SHOWERS AND THUNDER INCREASE INTO THE AFTERNOON.
ONE OF THE BIGGER CHANGES TO THE GOING FORECAST IS WITH RESPECT TO
THE MASSIVE AND PERSISTENT STACKED LOW THAT IS SLOWLY MOVING ACROSS
THE CENTRAL US. THE CHANGE TONIGHT IS THAT THE LOW IS NOW PROGGED TO
MOVE A LITTLE FARTHER NORTH THAN EARLIER ANTICIPATED. BY BRINGING
THE CORE A LITTLE FARTHER NORTH...WE ARE NOW GOING TO INTRODUCE A
LITTLE COOLER AIR ALOFT BY THE AFTERNOON HOURS. SURFACE DEWPOINTS IN
THE UPPER 50S TO LOWER 60S TO CONTINUE INTO THE AFTERNOON
HOURS...AND WILL HELP TO SUPPORT MEAN LAYER CAPE VALUES IN THE
800-1000 J/KG REGION. LOWER LEVEL SHEAR IS PRETTY MARGINAL...THOUGH
FORECAST SOUNDINGS DO SHOW A SIGNAL OF CURL TO THE HODOGRAPH. SPC
SREF ANALYSIS INDICATES EFFECTIVE SHEAR TO BE IN THE 30-35-40 KT
REALM FROM THE 18 TO TO 00Z HOUR FROM CMI TO IKK AND FLIRTING WITH
ORD /THOUGH REACHING 40KT MAY BE A STRETCH/...THEN IN THE 00Z TO
06Z HOURS SHIFTING EAST AND ACROSS NORTHERN INDIANA. PREVIOUS OFF
HOUR RUNS OF THE NAM AND GFS ALSO INDICATE A LITTLE SPEED MAX
RIPPLING THROUGH...WITH THE FAVORED ENTRANCE REGION MOVING
OVERHEAD INTO THE AFTERNOON HOURS. THAT HAS NOW SHIFTED A LITTLE
EAST...AND WHILE IT ISNT EXACTLY THE MOST FAVORABLE SETUP FOR
CONVECTION...CANT RULE OUT MORE THAN RAIN AND WILL ADD THE MENTION
OF THUNDER THROUGH THE AFTERNOON HOURS. THE BIGGEST THREAT WITH
THE COOLING ALOFT AND THE INCREASED LAPSE RATES WILL BE MARGINAL
HAIL...BUT CAN FORESEE SOME STORMS THAT POP THIS AFTERNOON TAKING
ON SIMILAR CHARACTERISTICS TO WHAT WAS OBSERVED IN THE LATE
EVENING ON THURSDAY...WHERE A FEW MULTICELLULAR CLUSTERS SHOW
SOME MID LEVEL ROTATION...AND THAT MAY GET CLOSE TO THE SURFACE.
BUT THE THREAT APPEARS LOW AND WILL BE MORE FOCUSED ON THE HAIL
THREAT...ESPECIALLY WITH THE LACK OF LOWER LEVEL SHEAR.
THE STREAK OF RECORD BREAKING TEMPERATURES AT ORD LOOKS TO FINALLY
BE OVER...AS THE RECORD HIGH FOR THE DATE IS 80 DEGREES. THE SURFACE
GRADIENT IS INCREDIBLY BAGGY THIS MORNING AND FLOW IS GENERALLY SSE
TO SE ACROSS THE REGION. AS THE SURFACE LOW TRACKS EAST ACROSS
SOUTHERN ILLINOIS...WINDS WILL BECOME MORE EASTERLY AND AREAS ALONG
THE LAKEFRONT WILL BE UNDER THE INFLUENCE OF THE COOLER
MARINE AIRMASS...AND THAT WILL HELP TO KEEP THE TEMPERATURES
CONSIDERABLY LOWER THAN HAS BEEN FELT THE PAST WEEK...GENERALLY
PEAKING IN THE MID/UPPER 60S. AN INTERESTING NOTE...EVEN WITH FLOW
OFF OF THE LAKE IN MID MARCH...DOWN TOWN CHICAGO WAS AT 54 DEGREES
AS OF 4AM. LAST YEAR LAKE MICHIGAN TEMPERATURES WERE 42 AT THE
SHORE...39 AT THE CRIB AND 38 AT MICHIGAN CITY INTAKE. THIS
YEAR...THEY ARE 49, 46 AND 44 RESPECTIVELY. THAT GOES TO HIGHLIGHT
HOW BIG OF A PLAYER THE LAKE CONTINUES TO PLAY IN TEMPERATURES.
WHILE IT WILL BE COOLER THAN WHAT HAS FELT LIKE THE NEW NORM...IT
WILL STILL BE ABOVE THE OFFICIAL NORMAL...WHICH IS 49 DEGREES.
GRANTED...IF AREAS WEST DO CLEAR OUT FOR LONGER THAN
ANTICIPATED...THEY WILL WARM CONSIDERABLY MORE THAN AREAS TO THE
EAST...BUT STILL NOT ANTICIPATING ANY RECORDS FOR THE DAY /AS
ROCKFORD/S RECORD FOR TODAY IS 82/. CIN BUILDS INTO THE EVENING AS
UPPER FLOW BACKS TO THE NORTHWEST AND THEN NORTH...AS THE DISH POT
LOW WOBBLES/MEANDERS EAST. CHANCE OF SHOWERS TO PERSIST THROUGH
THE DAY ON SATURDAY WITH DEEP CYCLONIC FLOW...THOUGH THE BETTERS
CHANCES WILL BE CLOSER TO THE LOW AND SOUTH ACROSS CENTRAL
ILLINOIS AND WEST CENTRAL INDIANA.
LONG TERM TRENDS STILL INDICATE BIGGER COOL DOWN SUNDAY NIGHT AND
INTO MONDAY. THE DISH POT WILL BE IN THE VICINITY OF THE LOWER
OHIO VALLEY BY THE END OF THE WEEKEND...TURNING ALL FLOW TO THE
NORTH AND NORTHWEST IN THAT TIME FRAME. THE GOOD NEWS IS THAT ANY
STRONG ADVECTION OF COLDER AIR THAT THE SYSTEM MAY HAVE HAD A WEEK
OR SO AGO WHEN IT WAS RAMPING UP...HAS BUT WASHED ITSELF OUT THIS
PAST WEEK. H8 TEMPS ARE PROGGED TO ONLY DIP INTO THE +6 TO +8
REALM WHICH MEANS THAT HIGHS ONLY EXPECTED IN THE LOWER 50S NORTH
OF I-88...TOUCHING 60 WELL SOUTH AND CLOSER TOWARDS ILX/S AREA OF
RESPONSIBILITY.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* OCCASIONAL SHOWERS THROUGH LATE MORNING.
* VARIABLE VSBY/CIGS WITH LOWEST IN/AROUND SHOWERS...BRIEF IFR IN SHRA.
* ORD VSBY LIKELY STAYING MVFR WITH COOLER NORTHEASTERLY WIND FLOW.
* LIGHT NORTHEAST WINDS AT ORD PERSISTING THROUGH MID AFTERNOON.
* LIGHT SOUTHEAST WINDS AT MDW SHOULD BECOME MORE EAST THEN
NORTHEAST INTO EARLY AFTERNOON.
* DECENT CHANCE FOR SCATTERED TS DEVELOPMENT THIS AFTERNOON.
* MAY SEE VARIABLE MVFR/VFR CIG/VSBY AWAY FROM SHRA/TSRA THIS
AFTERNOON.
MDB
//DISCUSSION...UPDATED 16Z...
VARIABLE CONDITIONS REMAIN ACROSS THE TERMINALS WITH EVERYTHING
FROM IFR TO VFR. BANDS OF SHOWERS CONTINUE TO ARC NORTHWARD FROM
UGN TO ORD TO MDW TO LAF. THIS ACTIVITY WILL CONTINUE TO SLOWLY
SHIFT TO THE EAST OVER THE NEXT FEW HOURS BUT WILL BRING PERIODIC
REDUCTIONS TO IFR VSBY. A CORRIDOR OF IFR CIGS HAS DEVELOP NEAR
AND UNDER THE SHOWER ACTIVITY STRETCHING AS FAR WEST AS DPA BUT
THIS SHOULD IMPROVE INTO EARLY THIS AFTERNOON. PREVAILING CIG/VSBY
TRENDS NOT AS CLEAR FOR THE AFTERNOON AS THEY WERE BUT EXPECT THAT
MVFR WILL PREVAIL TO START BUT THERE MAY BE IMPROVEMENT TO MVFR AT
SOME POINT. FLOW OFF THE LAKE ACROSS THE CHI METRO MAY KEEP LOWER
CIGS AND VSBY IN PLACE AT ORD/MDW AND PERHAPS EVENTUALLY GYY
CONFIDENCE IN THE SPECIFICS IS LIMITED. EXPECT THAT ORD WILL KEEP
A NE WIND WITH MDW ON THE FRINGE OF THE LAKE FLOW BUT LIKELY
REMAINING EAST OR EAST-NORTHEAST. DPA WILL LIKELY BE IN THE SAME
SCENARIO...WITH GYY EXPECTED TO FLIP NORTHEAST AT SOME POINT THIS
AFTERNOON. RFD SHOULD STAT MORE SOUTHEAST BEFORE SHIFTING EAST AND
NORTHEAST LATER TODAY.
NEXT CONCERN IS POTENTIAL FOR NEW SHRA/TSRA DEVELOPMENT THIS
AFTERNOON. AM CONCERNED ABOUT NEW DEVELOPMENT IN AN AREA OF
SCATTERED/CLEAR SKIES FROM SQI-RFD-NEAR IKK-PNT WITH SOME
INSTABILITY BUILDING AS A RESULT. THIS DEVELOPMENT MAY OCCUR BY
EARLY AFTERNOON AND LIFT NORTHEAST BUT THIS WILL REMAIN TO BE
SEEN. ANOTHER ROUND OF CONVECTION WILL BE POSSIBLE LATER THIS
EVENING BUT CONFIDENCE IN THIS IS NOT HIGH.
MDB
FROM 12Z...
VERY CHALLENGING AVIATION FORECAST CONTINUES WITH PERIODIC
SHRA/ISO TS. GUIDANCE CONTINUES TO SLIDE THE UPPER LEVEL
DISTURBANCE ACROSS CENTRAL IL. IR IMAGERY INDICATED SOME THINNING
WAS TAKING PLACE ACROSS A NARROW CHANNEL FROM NORTHWEST IL
STRETCHING SOUTHEAST THROUGH CENTRAL IL/SOUTHERN IL. IN THIS
COLUMN CIGS/VSBYS HAVE REDUCED TO MVFR WITH PATCHY IFR. IT DOES
NOT APPEAR THAT THIS WILL IMPACT THE NORTHERN IL AIRFIELDS AT THIS
POINT...HOWEVER SLIGHT REDUCTION IN CIGS/VSBYS MAY OCCUR DUE TO
THE RECENT RAINFALL AND LACK OF MIXING TO SCOUR LLVL MOISTURE.
HAVE HANDLED THIS WITH SLIGHT REDUCTION OF CIGS TO MVFR.
INCREASED INSTABILITY COULD RESULT IN ANOTHER ROUND OF SHRA/TSRA
DURING THE AFTN/EVE HOURS BEFORE COMING TO AN END EARLY SAT
MORNING. HOWEVER...IT APPEARS THAT SOME FG WILL BEGIN TO FORM LATE
FRI NIGHT AND COULD PRODUCE A FEW AREAS OF DENSE FOG GIVEN THE
RECENT RAINFALL.
THE OTHER AVIATION CHALLENGE OVERNIGHT WILL CONTINUE TO REVOLVE
AROUND WIND DIR. WITH THE LACK OF A SOLID GRADIENT TO PRODUCE A
PREVAILING WIND DIR...WINDS CONTINUE TO BE FLUID BETWEEN 040-110
DEG ARND 4 TO 6 KT. EXPECT A SLIGHT INCREASE IN THE GRADIENT OVER
THE NEXT FEW HOURS AND SHUD PROVIDE A MORE DEFINED DIR...HOWEVER
THE UPPER LEVEL DISTURBANCE WILL BE TRAVERSING THE REGION AND
STILL PROVIDE CHANGING WIND DIR FROM THE NE TO SE.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN SHRA CONTINUING FOR SEVERAL HOURS THIS MORNING.
* HIGH CONFIDENCE IN VARIABLE CIG/VSBY THIS MORNING...WITH BRIEF
IFR IN SHRA.
* MEDIUM-HIGH CONFIDENCE IN ORD VSBY REMAINING MVFR OUTSIDE OF
SHRA THIS MORNING.
* MEDIUM CONFIDENCE IN WIND DIRECTION TRENDS AT ORD.
* LOW-MEDIUM CONFIDENCE IN WIND DIRECTION TRENDS AT MDW.
* MEDIUM CONFIDENCE IN SHRA/TSRA DEVELOPMENT THIS AFTERNOON BUT
LOW CONFIDENCE IN TIMING/EXTENT OF IMPACTS AT THE TERMINALS.
* LOW-MEDIUM CONFIDENCE IN CIG/VSBY TRENDS THIS AFTERNOON.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...VFR. PSBL FG DEVELOPMENT.
SUNDAY...VFR.
MONDAY...VFR.
TUESDAY...VFR. PSBL MVFR CIGS WITH CHC SHRA/ISO TS.
WEDNESDAY...MVFR EARLY TRENDING VFR. CHC RA/TS EARLY.
THURSDAY...VFR.
BEACHLER
&&
.MARINE...
251 AM CDT
A COUPLE WEATHER FEATURES CONTINUE TO POSE CHALLENGES TO THE
WEATHER ACROSS THE MARINE COMMUNITY...AS AN UPPER LEVEL
DISTURBANCE SLOWLY LIFTS NORTHEAST FROM THE CENTRAL PLAINS TOWARDS
THE SOUTHERN GREAT LAKES TODAY. MEANWHILE A BROAD AREA OF HIGH
PRESSURE OVER NORTHERN MANITOBA WILL DRIFT EAST AND BECOME
CENTERED OVER HUDSON BAY TONIGHT INTO SATURDAY. THIS WILL ALLOW A
GRADIENT TO STEADILY INCREASE ACROSS THE NORTHERN PORTIONS OF THE
LAKE TODAY...WITH WINDS COMING UP TO 15 TO 25 KT. A FEW GUSTS UP
TO 30 KT WILL BE POSSIBLE. ELSEWHERE WITH THE LACK OF A STRONG
GRADIENT...WINDS WILL BE MUCH LIGHTER FROM THE EAST. THIS WILL
ALLOW WAVES TO BE HIGHER ALONG THE WESTERN SIDE OF LAKE MICHIGAN.
AT THIS TIME IT DOES NOT APPEAR WAVES WILL BE LARGE ENOUGH TO
WARRANT ANY HEADLINES IN THE NEARSHORE WATERS FOR
ILLINOIS/NORTHWEST INDIANA. THEN AS THE UPPER LEVEL DISTURBANCE
DRIFTS EAST...A WEAK LOW PRESSURE SYSTEM WILL TRAVERSE LAKE
SUPERIOR. BEHIND THIS SYSTEM ON SUNDAY...A STRONG HIGH PRESSURE
WILL BUILD IN AND TIGHTEN THE GRADIENT YET AGAIN. THIS SHOULD
ALLOW WINDS TO STEADILY INCREASE.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1215 AM CDT FRI MAR 23 2012
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TODAY/...
BIGGEST FOCUS TODAY WILL BE ON FOG THIS MORNING...AND THEN CHANCES
FOR SHOWERS ACROSS THE SOUTHERN CWA. FOG HAS DEVELOPED ACROSS MUCH
OF THE CWA...MAINLY NORTH AND EAST OF A LINE FROM OTTUMWA...TO DES
MOINES...TO CARROLL. FOG EXPECTED TO PERSIST ACROSS THE AREA INTO
THE MID MORNING HOURS...WITH WINDS EXPECTED TO REMAIN LIGHT AND
CONTINUE TO HAVE MOISTURE NEAR SURFACE CONDITIONS DUE TO RESIDUAL
MOISTURE FROM RAINFALL OVER THE PAST FEW DAYS. MAJORITY OF VSBYS
RANGING FROM NEAR ZERO TO AROUND ONE QUARTER MILE AND ARE ONLY
EXPECTED TO WORSEN THROUGH SUNRISE...WITH THE HRRR KEEPING VSBYS AT
A QUARTER MILE OR BELOW THROUGH 15Z. THEREFORE HAVE OPTED TO ISSUE A
DENSE FOG ADVISORY FOR MUCH OF THE CWA THROUGH 15Z. FOG SHOULD THEN
LIFT INTO SOME LOW STRATUS AND THEN BREAK UP SOME BY LATE MORNING
INTO THE EARLY AFTERNOON HOURS. WITH THE UPPER LOW CHURNING TO THE
SOUTH OF THE CWA...AND CONTINUED CYCLONIC FLOW OVER THE STATE...DO
NOT EXPECT SKIES TO CLEAR COMPLETELY TODAY...WITH SOME SHOWERS
POSSIBLE ACROSS SOUTHERN CWA THROUGHOUT THE DAY AS BANDS OF LIGHT
SHOWERS CONTINUE TO ROTATE NORTHWARD FROM MISSOURI AROUND MAIN LOW
TO THE SOUTH OF THE CWA. ANY PRECIP ROTATING BACK INTO THE AREA
ACROSS NORTHEASTERN CWA APPEARS TO HOLD OFF UNTIL AFTER 00Z. WITH
H85 TEMPERATURES AROUND +9C...A COOLER START TO THE DAY...AND CLOUD
COVER/LINGERING FOG HAVE TEMPS IN THE UPPER 60S TO AROUND 70.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
THOUGH THE UPPER LOW CENTER IS CURRENTLY OVER FAR SOUTHEAST
KANSAS...THE STRONGEST PV ANOMALY ASSOCIATED WITH THE SYSTEM IS
ROUNDING THROUGH CNTRL ARKANSAS. THIS WILL HELP KEEP THE UPPER LOW
ON A MORE SOUTHERLY TRACK BY THIS EVENING AS IT TRACKS INTO THE
LOWER OHIO VALLEY. ONE FINAL PIECE OF ENERGY WILL WRAP AROUND THE
SYSTEM AND INTO EASTERN AS THE SYSTEM DEPARTS TONIGHT. THIS WILL
BRING ONE LAST CHANCE FOR SHOWERS EAST OF INTERSTATE 35. THE AREA
WILL QUICKLY TRANSITION OUT OF CYCLONIC FLOW ON SATURDAY WITH
RIDGING BUILDING IN FROM THE WEST. DESPITE NW FLOW...SOME SFC WARM
ADVECTION WILL BE TAKING PLACE. THE NW FLOW WILL ALSO AID DESCENT
MIXING AND THERE SHOULD BE AN ABUNDANCE OF SUNSHINE CENTRAL AND WEST
WITH A FEW CLOUDS LINGERING OVER THE EAST. A WEAK FRONTAL BOUNDARY
WILL REACH THE NORTHERN THIRD OF THE STATE SATURDAY NIGHT AND SUNDAY
THOUGH THE GREATEST IMPACTS WILL MOVE THROUGH PORTIONS OF MINNESOTA
AND WISCONSIN. SHOULD BE A PLEASANT DAY OVERALL WITH HIGHS IN THE
60S AND 70S WITH LIGHT WINDS.
THE MONDAY FORECAST CONTINUES TO BECOME MORE COMPLEX. THE
AFOREMENTIONED COLD ADVECTION THROUGH WISCONSIN SUNDAY WILL SHIFT
WEST AS A BACK DOOR COLD FRONT OFF LAKE MICHIGAN SUNDAY NIGHT AND
MONDAY. WARM ADVECTION WILL BE LIFTING INTO WESTERN IOWA BY MONDAY
MORNING HOWEVER ITS EASTWARD ADVANCE WILL LIKELY BE OVERCOME BY THE
COOLER AND MORE DENSE AIR FILTERING IN FROM THE EAST. HIGH
TEMPERATURES AT THIS POINT COULD BE TOO HIGH BY SEVERAL DEGREES IF
THE THIS BOUNDARY COMES IN AS STRONG AS SUGGESTED. DESPITE
THIS...MID LEVEL WARM ADVECTION WILL CONTINUE TO OVERSPREAD THE AREA
MONDAY WITH SOME INSTABILITY DEVELOPING AHEAD OF THE LOW LEVEL JET
AND STRONG THETA E ADVECTION. BEST POTENTIAL FOR THUNDERSTORMS WOULD
BE OVER THE NORTH. ANY THUNDER AT THIS TIME LIKELY WILL BE ELEVATED
THOUGH A MARGINAL SEVERE STORM WOULD BE POSSIBLE. BOWLING BALL UPPER
LOW LIFTING INTO THE NORTHERN PLAINS ON TUESDAY COULD PRODUCE SOME
INTERESTING WEATHER TUESDAY PENDING EXACT TIMING AND PLACEMENT OF
THE SYSTEM. COOLER AIR WILL SINK IN BEHIND THE SYSTEM THOUGH AGAIN
THE GREATEST IMPACT WILL BE TO THE NORTHEAST. TEMPERATURES WILL
REMAIN WELL ABOVE SEASONAL VALUES WITH LOW POTENTIAL FOR
PRECIPITATION WEDNESDAY AND THURSDAY.
&&
.AVIATION...23/18Z
EARLY MORNING FOG HAS LIFTED...WITH A FEW SITES...KOTM/KFOD STILL
EXPERIENCING LOW MVFR CEILINGS. THESE WILL CONTINUE TO LIFT THROUGH
THE EARLY PERIOD...WITH VFR CEILINGS THROUGH 06Z. FOG IS POSSIBLE
AGAIN AT SITES NEAR 12Z...AND HAVE TRENDED VISIBILITIES DOWN.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE
&&
$$
SHORT TERM...BEERENDS
LONG TERM...DONAVON
AVIATION...AWB
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
116 PM CDT FRI MAR 23 2012
.UPDATE...HAVE ALLOWED THE DFA TO EXPIRE AS VISIBILITY HAS IMPROVED
SOMEWHAT AROUND SWRN CWA. TWIN PORTS REGION STILL LOCALLY DENSE.
MNDOT WEBCAMS SHOW LOW VISIBILITY IN SOME LOCATIONS WHILE OTHERS HAVE
CLEARLY IMPROVED VISIBILITY COMPARED TO EARLIER IMAGES. MAY NEED
TO REISSUE DFA FOR LATER TODAY/OVERNIGHT BASED ON SATURATED NEAR
SFC PROFILE/NOCTURNAL COOLING/PROXIMITY OF LAKE COLD WEDGE.
LOWERED MAX TEMPS EARLIER BASED ON CLOUID COVER/PRECIP/FOG.
&&
.PREV DISCUSSION... /ISSUED 1246 PM CDT FRI MAR 23 2012/
AVIATION...18Z TAF ISSUANCE...
LIFR VSBYS AND CIGS ARE EXPECTED TO CONTINUE THROUGH TOMORROW
MORNING AS A STREAM OF LOW LEVEL MOISTURE CONTINUES TO GET PUMPED
IN FROM THE SE AROUND THE NRN EDGE OF A CUT OFF UPPER LOW OVER THE
LOWER MS VALLEY. THE ADDED INFLUENCE OF LAKE SUPERIOR IS ALSO
HELPING TO INCREASE NEAR SFC MOISTURE AND AIDING IN THE FOG
PERSISTENCE. COULD SEE A COUPLE HOURS THIS AFTERNOON WHERE CIGS
LIFT SLIGHTLY TO LOW-END MVFR AND VSBYS IMPROVE TO GT 3SM. THE
BEST CHANCE WILL BE AROUND HYR AND BRD. A FEW LIGHT RAIN SHOWERS
WILL BE LINGERING AROUND INL EARLY THIS AFTERNOON...WITH MOST OF
THE WIDESPREAD PRECIP ENDING BY MID AFTERNOON. FOG RETURNS TONIGHT
TO MOST TERMINALS...WITH THE BEST CHANCE OF 1/4SM OR LESS AT DLH
AND HIB. SHOULD SEE RAPID IMPROVEMENT IN VSBYS BY LATE SAT
MORNING.
PREV DISCUSSION... /ISSUED 859 AM CDT FRI MAR 23 2012/
UPDATE...ISSUED DFA AS LATEST SFC OBS/WEBCAMS SHOW EXTENSIVE
AREA OF DENSE FOG ACROSS NSHORE...TWIN PORTS...SOUTH
SHORE...BRAINERD LAKES/CASS LAKE VICINITY. RUC13 SNDGS SUPPORT
CONTINUATION OF MOIST INVERSION PROFILE THROUGH AT LEAST
MIDDAY...IF NOT LONGER. GIVEN THE DIFFICULT NATURE OF FORECASTING
THIS PARTICULAR ELEMENT...WILL NEED TO MONITOR THROUGH NEXT FEW
HRS FOR UPDATES TO AREAL COVERAGE/TIMING.
PREV DISCUSSION... /ISSUED 638 AM CDT FRI MAR 23 2012/
AVIATION...12Z TAF ISSUANCE...
WIDESPREAD LIFR/IFR CONDITIONS ARE LIKELY THROUGH LATE THIS
MORNING ACROSS THE REGION DUE TO VERY LOW CIGS AND FG/BR/-RA.
CONDITIONS ARE PROJECTED TO IMPROVE LATE THIS MORNING AND THIS
AFTERNOON TO MORE IFR/MVFR CONDITIONS...BUT BE PREPARED FOR SOME
AREAS TO HAVE LINGERING LIFR CONDITIONS. CONDITIONS SHOULD THEN
WORSEN AGAIN TONIGHT TO LIFR/IFR CONDITIONS DUE TO VERY LOW CIGS
AND FG.
PREV DISCUSSION... /ISSUED 335 AM CDT FRI MAR 23 2012/
SHORT TERM....TODAY THROUGH SATURDAY.
CURRENT RADAR IMAGERY AND SFC ANALYSIS SHOWS WEAK EAST/SOUTHEAST FLOW
WITH SCT RAIN SHOWERS OVER THE CWA. A CORRIDOR OF MODERATE TO
HEAVY RAIN IS FOUND ALONG THE INTERNATIONAL BORDER NEAR THE
OCCLUDED FRONT THAT HAS NOW PUSHED NORTH INTO CANADA. RADAR
ESTIMATED RAINFALL OVER THE PAST 48 HRS RANGES FROM A QUARTER OF
AN INCH IN MOST AREAS...TO HIGHER AMOUNTS OF A HALF TO ONE INCH IN
THE IRON RANGE/ARROWHEAD REGION. AT 300 AM...THE HEAVIEST AMOUNTS
WERE ACROSS NORTHERN ST LOUIS/LAKE COUNTIES WHERE RADAR ESTIMATED
VALUES WERE AROUND AN INCH AND A HALF.
A WELL DEFINED CUT OFF LOW IS CURRENTLY SEEN ON SAT IMAGERY ROTATING
OVER THE CENTRAL PLAINS...CONTINUING TO WRAP WARM HUMID AIR FROM THE
GULF NORTH INTO THE WESTERN GREAT LAKES REGION. WINDS WILL REMAIN
NORTHEAST OVER LAKE SUPERIOR TODAY RESULTING IN COOLER TEMPERATURES
AROUND 45-50 DEGREES LAKESIDE. ELSEWHERE...ANOTHER MILD MARCH DAY
IN THE 60S WITH RAIN SHOWERS/DRIZZLE WILL PREVAIL.
THE LOW WILL GRADUALLY PUSH EAST INTO THE SRN INDIANA/KENTUCKY
REGION THROUGH SATURDAY...ALLOWING FOR UPPER LEVEL RIDING TO BUILD
INTO THE NRN PLAINS. SHORT RANGE MODELS IN AGREEMENT CLOUDS AND
HIGH HUMIDITIES LINGER OVER THE NORTHLAND THROUGH SATURDAY
MORNING...GRADUALLY ERODING IN THE WRN ZONES SAT AFTN. HAVE
INTRODUCED FOG AND DRIZZLE TO ERN HALF OF CWA OVERNIGHT WHERE
SFC-H85 PROFILES REMAIN SATURATED BUT LACK FORCING FOR
SHOWERS/MEASURABLE RAINFALL.
LONG TERM [SATURDAY NIGHT - THURSDAY]...
THE MODELS ARE IN FAIRLY GOOD AGREEMENT...SO LEANED ON A BLEND. THE
MODEL CONSENSUS IS FOR A PASSING COLD FRONT SATURDAY
NIGHT...BRINGING THE NORTHLAND AND MUCH COOLER AND DRIER SUNDAY.
HIGH PRESSURE SHOULD KEEP MOST OF THE REGION DRY MONDAY...BUT HAD TO
INCLUDE SOME LOW POPS FOR SHOWERS AND THUNDERSTORMS ACROSS THE
WESTERN AND SOUTHERN FA DUE TO THE MODELS INDICATING PCPN IN THE
PLAINS FROM ORGANIZING LOW PRESSURE. THAT LOW PRESSURE SYSTEM SHOULD
THEN MOVE ACROSS THE DAKOTAS INTO CENTRAL/NORTHERN MINNESOTA THROUGH
TUESDAY....AND THEN OVER THE GREAT LAKES THROUGH WEDNESDAY. THE
PASSAGE OF THE SYSTEM COULD BRING SHOWERS AND STORMS TO THE
NORTHLAND. HIGH PRESSURE SHOULD THEN PROVIDE DRY WEATHER THURSDAY.
TEMPERATURES WILL GENERALLY REMAIN ABOVE NORMAL THROUGH THE LONG
TERM PERIOD.
&&
.POINT TEMPS/POPS...
DLH 42 62 35 50 / 20 10 10 10
INL 46 66 27 43 / 10 10 10 10
BRD 47 70 35 55 / 10 10 10 10
HYR 47 68 40 57 / 20 10 10 10
ASX 42 60 37 48 / 30 10 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...DENSE FOG ADVISORY UNTIL 10 AM CDT SATURDAY FOR LSZ121-140>148.
&&
$$
SHORT TERM...CANNON
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1246 PM CDT FRI MAR 23 2012
.AVIATION...18Z TAF ISSUANCE...
LIFR VSBYS AND CIGS ARE EXPECTED TO CONTINUE THROUGH TOMORROW
MORNING AS A STREAM OF LOW LEVEL MOISTURE CONTINUES TO GET PUMPED
IN FROM THE SE AROUND THE NRN EDGE OF A CUT OFF UPPER LOW OVER THE
LOWER MS VALLEY. THE ADDED INFLUENCE OF LAKE SUPERIOR IS ALSO
HELPING TO INCREASE NEAR SFC MOISTURE AND AIDING IN THE FOG
PERSISTENCE. COULD SEE A COUPLE HOURS THIS AFTERNOON WHERE CIGS
LIFT SLIGHTLY TO LOW-END MVFR AND VSBYS IMPROVE TO GT 3SM. THE
BEST CHANCE WILL BE AROUND HYR AND BRD. A FEW LIGHT RAIN SHOWERS
WILL BE LINGERING AROUND INL EARLY THIS AFTERNOON...WITH MOST OF
THE WIDESPREAD PRECIP ENDING BY MID AFTERNOON. FOG RETURNS TONIGHT
TO MOST TERMINALS...WITH THE BEST CHANCE OF 1/4SM OR LESS AT DLH
AND HIB. SHOULD SEE RAPID IMPROVEMENT IN VSBYS BY LATE SAT
MORNING.
&&
.PREV DISCUSSION... /ISSUED 859 AM CDT FRI MAR 23 2012/
UPDATE...ISSUED DFA AS LATEST SFC OBS/WEBCAMS SHOW EXTENSIVE
AREA OF DENSE FOG ACROSS NSHORE...TWIN PORTS...SOUTH
SHORE...BRAINERD LAKES/CASS LAKE VICINITY. RUC13 SNDGS SUPPORT
CONTINUATION OF MOIST INVERSION PROFILE THROUGH AT LEAST
MIDDAY...IF NOT LONGER. GIVEN THE DIFFICULT NATURE OF FORECASTING
THIS PARTICULAR ELEMENT...WILL NEED TO MONITOR THROUGH NEXT FEW
HRS FOR UPDATES TO AREAL COVERAGE/TIMING.
PREV DISCUSSION... /ISSUED 638 AM CDT FRI MAR 23 2012/
AVIATION...12Z TAF ISSUANCE...
WIDESPREAD LIFR/IFR CONDITIONS ARE LIKELY THROUGH LATE THIS
MORNING ACROSS THE REGION DUE TO VERY LOW CIGS AND FG/BR/-RA.
CONDITIONS ARE PROJECTED TO IMPROVE LATE THIS MORNING AND THIS
AFTERNOON TO MORE IFR/MVFR CONDITIONS...BUT BE PREPARED FOR SOME
AREAS TO HAVE LINGERING LIFR CONDITIONS. CONDITIONS SHOULD THEN
WORSEN AGAIN TONIGHT TO LIFR/IFR CONDITIONS DUE TO VERY LOW CIGS
AND FG.
PREV DISCUSSION... /ISSUED 335 AM CDT FRI MAR 23 2012/
SHORT TERM....TODAY THROUGH SATURDAY.
CURRENT RADAR IMAGERY AND SFC ANALYSIS SHOWS WEAK EAST/SOUTHEAST FLOW
WITH SCT RAIN SHOWERS OVER THE CWA. A CORRIDOR OF MODERATE TO
HEAVY RAIN IS FOUND ALONG THE INTERNATIONAL BORDER NEAR THE
OCCLUDED FRONT THAT HAS NOW PUSHED NORTH INTO CANADA. RADAR
ESTIMATED RAINFALL OVER THE PAST 48 HRS RANGES FROM A QUARTER OF
AN INCH IN MOST AREAS...TO HIGHER AMOUNTS OF A HALF TO ONE INCH IN
THE IRON RANGE/ARROWHEAD REGION. AT 300 AM...THE HEAVIEST AMOUNTS
WERE ACROSS NORTHERN ST LOUIS/LAKE COUNTIES WHERE RADAR ESTIMATED
VALUES WERE AROUND AN INCH AND A HALF.
A WELL DEFINED CUT OFF LOW IS CURRENTLY SEEN ON SAT IMAGERY ROTATING
OVER THE CENTRAL PLAINS...CONTINUING TO WRAP WARM HUMID AIR FROM THE
GULF NORTH INTO THE WESTERN GREAT LAKES REGION. WINDS WILL REMAIN
NORTHEAST OVER LAKE SUPERIOR TODAY RESULTING IN COOLER TEMPERATURES
AROUND 45-50 DEGREES LAKESIDE. ELSEWHERE...ANOTHER MILD MARCH DAY
IN THE 60S WITH RAIN SHOWERS/DRIZZLE WILL PREVAIL.
THE LOW WILL GRADUALLY PUSH EAST INTO THE SRN INDIANA/KENTUCKY
REGION THROUGH SATURDAY...ALLOWING FOR UPPER LEVEL RIDING TO BUILD
INTO THE NRN PLAINS. SHORT RANGE MODELS IN AGREEMENT CLOUDS AND
HIGH HUMIDITIES LINGER OVER THE NORTHLAND THROUGH SATURDAY
MORNING...GRADUALLY ERODING IN THE WRN ZONES SAT AFTN. HAVE
INTRODUCED FOG AND DRIZZLE TO ERN HALF OF CWA OVERNIGHT WHERE
SFC-H85 PROFILES REMAIN SATURATED BUT LACK FORCING FOR
SHOWERS/MEASURABLE RAINFALL.
LONG TERM [SATURDAY NIGHT - THURSDAY]...
THE MODELS ARE IN FAIRLY GOOD AGREEMENT...SO LEANED ON A BLEND. THE
MODEL CONSENSUS IS FOR A PASSING COLD FRONT SATURDAY
NIGHT...BRINGING THE NORTHLAND AND MUCH COOLER AND DRIER SUNDAY.
HIGH PRESSURE SHOULD KEEP MOST OF THE REGION DRY MONDAY...BUT HAD TO
INCLUDE SOME LOW POPS FOR SHOWERS AND THUNDERSTORMS ACROSS THE
WESTERN AND SOUTHERN FA DUE TO THE MODELS INDICATING PCPN IN THE
PLAINS FROM ORGANIZING LOW PRESSURE. THAT LOW PRESSURE SYSTEM SHOULD
THEN MOVE ACROSS THE DAKOTAS INTO CENTRAL/NORTHERN MINNESOTA THROUGH
TUESDAY....AND THEN OVER THE GREAT LAKES THROUGH WEDNESDAY. THE
PASSAGE OF THE SYSTEM COULD BRING SHOWERS AND STORMS TO THE
NORTHLAND. HIGH PRESSURE SHOULD THEN PROVIDE DRY WEATHER THURSDAY.
TEMPERATURES WILL GENERALLY REMAIN ABOVE NORMAL THROUGH THE LONG
TERM PERIOD.
&&
.POINT TEMPS/POPS...
DLH 49 42 62 35 / 50 20 10 10
INL 58 46 66 27 / 80 10 10 10
BRD 62 47 70 35 / 40 10 10 10
HYR 64 47 68 40 / 60 20 10 10
ASX 50 42 60 37 / 60 30 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR MNZ020-021-
025-026-033>037.
WI...DENSE FOG ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR WIZ001>003.
LS...DENSE FOG ADVISORY UNTIL 10 AM CDT SATURDAY FOR LSZ121-140>148.
&&
$$
AVIATION...TENTINGER
AREA FORECAST DISCUSSION
NWS HASTINGS NE
354 PM CDT FRI MAR 23 2012
.SHORT TERM...THROUGH SATURDAY AFTERNOON. NEEDLESS TO SAY...THE
NEXT 24 HOURS CONTINUE THE RETURN TO INCREDIBLY NICE LATE MARCH
WEATHER...WITH HIGH TEMPS ON SATURDAY FORECAST TO BE RIGHT AROUND
CLIMATOLOGICAL NORMALS FOR LATE MAY/EARLY JUNE.
STARTING OFF AT 20Z THIS AFTERNOON...A LIGHT AND SOMEWHAT VARIABLE
WIND REGIME IS IN PLACE ACROSS THE CWA...THANKS TO A BROAD DIFFUSE
RIDGE AXIS. THE COMBINATION OF MODEST BOUNDARY LAYER
MOISTURE...ALONG WITH SOME COOLER MID LEVEL AIR ON THE BACK SIDE
OF THE DEPARTING CLOSED LOW OVER SOUTH CENTRAL MISSOURI...HAS
RESULTED IN A LEGITIMATE SCATTERED FAIR WEATHER CUMULUS FIELD
ESPECIALLY ACROSS THE EASTERN HALF OF THE CWA. ALTHOUGH THIS
SCATTERED TO LOCALLY BROKEN DECK WAS A BIT MORE CLOUD COVER THAN
EARLIER EXPECTED...TEMPS HAVE HAD STILL HAD NO PROBLEMS MAKING IT
INTO AT LEAST THE MID-UPPER 60S AT THIS HOUR...WITH SOME PLACES
POSSIBLY TOUCHING 70 BY DAYS END. AS MENTIONED...WATER VAPOR
IMAGERY AND SHORT TERM MODEL DATA CLEARLY REVEAL THE DEPARTING
CLOSED LOW AS THE MAIN MID/UPPER FEATURE OF INTEREST...WITH
SHORTWAVE RIDGING NOW BUILDING ALONG AN AXIS FROM THE SOUTHERN
ROCKIES TO NORTHERN PLAINS...AND THE NEXT LOW PRESSURE SYSTEM OF
INTEREST STILL WELL OFF THE PACIFIC COAST.
FOR LATE THIS AFTERNOON...HAVE KEPT THE FORECAST DRY...ALTHOUGH
THE HRRR CONTINUES TO INSIST THAT A FEW SPRINKLES COULD FLIRT WITH
FAR SOUTHEAST EDGES OF THE CWA. BASED ON LATEST VIS SATELLITE
TRENDS...ANY SLIGHTLY ENHANCED CUMULUS GROWTH POTENTIALLY
CONDUCIVE TO SPRINKLES/LIGHT RAIN SHOULD REMAIN JUST EAST OF THESE
COUNTIES.
THIS EVENING/TONIGHT...BOUNDARY LAYER CUMULUS DEVELOPMENT SHOULD
QUICKLY FADE AWAY...RESULTING IN ESSENTIALLY CLEAR SKIES AS
SHORTWAVE RIDGING CONTINUES TO NOSE OVERHEAD IN THE WAKE OF THE
DEPARTING LOW...WHICH WILL BE NEAR THE IL/IN/KY BORDER AREA BY
12Z. BREEZES WILL REMAIN LIGHT OVERNIGHT...BUT THE DIRECTION WILL
PREVAIL FROM THE WEST/SOUTHWEST. ONLY POTENTIAL ISSUE IS FOG
DEVELOPMENT OVERNIGHT. VARIOUS MODEL BOUNDARY LAYER RELATIVE
HUMIDITY PROGS...ALONG WITH MET/MAV VISIBILITY GUIDANCE...SUGGEST
THAT THIS LIGHT WESTERLY LOW LEVEL FLOW WILL NOT BE VERY CONDUCIVE
TO FOG DEVELOPMENT. THAT BEING SAID...AT LEAST LIGHT FOG HAS
DEVELOPED HERE AND THERE ACROSS THE CWA THE PAST FEW NIGHTS
LARGELY DUE TO MOIST GROUND IN THE WAKE OF RECENT RAINFALL. GIVEN
THAT PATCHY FOG WORDING HAS ALREADY BEEN IN THE FORECAST FOR OVER
24 HOURS NOW IN SOME AREAS...WILL LET IT RIDE...BUT WOULD BE VERY
SURPRISED TO SEE MORE THAN PATCHY LIGHT VISIBILITY RESTRICTIONS.
FOR LOW TEMPS...KEPT SIMILAR TO PREVIOUS FORECAST IN EASTERN
ZONES...BUT BUMPED DOWNWARD A FEW DEGREES IN THE WEST...RESULTING
IN A RANGE FROM MID-UPPER 30S WEST...LOW 40S CENTRAL...MID 40S
SOUTHEAST. BASED ON WHAT HAPPENED THIS MORNING WITH LOWS TUMBLING
INTO THE LOW 30S WEST...WOULD NOT BE SURPRISED IF TONIGHTS LOWS
END UP A BIT LOWER THAN FORECAST. HOWEVER...THE LIGHT WESTERLY
BREEZES SHOULD HELP HOLD THINGS UP A BIT VERSUS LAST NIGHT.
SATURDAY...THE MID/UPPER PATTERN REMAINS QUITE TRANQUIL...AS THE
HEART OF THE 700-500MB RIDGE BUILDS OVER THE PLAINS...WELL TO THE
EAST OF THE DEEP TROUGH AXIS OFF THE PACIFIC COAST...AND THE
PRIMARY 300MB JET AXIS SNAKING FROM NORTHERN CA THEN EASTWARD
ACROSS SOUTHERN CANADA. AS A SURFACE HIGH PRESSURE SYSTEM WORKS
INTO SOUTHERN CANADA INTO THE DAKOTAS...A VERY WEAK COLD FRONT
WILL PUSH SOUTHWARD TOWARD/INTO THE NORTHWEST CWA DURING THE
AFTERNOON. OTHERWISE...LIGHT SOUTHWEST BREEZES WILL PREVAIL ACROSS
MOST OF THE CWA FOR THE MAJORITY OF THE DAY. WITH FORECAST
SOUNDINGS A BIT DRIER IN THE BOUNDARY LAYER COMPARED TO
TODAY...NOT ANTICIPATING MUCH CUMULUS DEVELOPMENT...AND IN FACT
VERY LITTLE CLOUD COVER. TEMP WISE...GIVEN THE WIDESPREAD SUN AND
850MB TEMPS CLIMBING WELL INTO THE 14-17C RANGE...A NOTABLE JUMP
IN AFTERNOON HIGHS IN LIKELY. DIDN/T GET TOO CARRIED AWAY...BUT
NUDGED UP PREVIOUS FORECAST TOWARD HIGHER END OF MET/MAV GUIDANCE
CONSENSUS...WITH MOST OF THE CWA INTO THE 78-80 RANGE.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY. WE KICK THINGS OFF
SATURDAY NIGHT WITH A PROMINENT UPPER RIDGE OVER THE PLAINS AND A
HIGHLY AMPLIFIED TROUGH ON ENTERING THE WEST COAST OF THE UNITED
STATES. WEATHER SHOULD REMAIN DRY INTO SUNDAY THANKS TO BEING
UNDER THE INFLUENCE OF NOT ONLY THE UPPER LEVEL RIDGE BUT A
SURFACE RIDGE AS WELL. THERE WILL BE A SURFACE TROUGH DEVELOPING
IN THE LEE OF THE ROCKIES BY SUNDAY NIGHT WITH A HEALTHY FAIRLY
STRONG LOW-LEVEL JET INCREASING OVER PARTS OF WESTERN AND CENTRAL
KANSAS...WITH THE NOSE OF THE JET MAKING ITS WAY INTO SOUTHERN AND
CENTRAL PARTS OF THE CWA BY LATE SUNDAY NIGHT...WITH THE NAM A BIT
STRONGER HERE...INDICATING A 50 KT JET...AS OPPOSED TO NEAR 40 KTS
FOR THE GFS AND ECMWF. AT THIS POINT...THERE DOES NOT APPEAR TO BE
ENOUGH MOISTURE TO GET ANY CONVECTION GOING...BUT IF THERE
WERE...STRONG TO SEVERE THUNDERSTORMS WOULD CERTAINLY NOT BE OUT
OF THE QUESTION. CONFIDENCE IS NOT HIGH ENOUGH TO INTRODUCE
CHANCES OF RAIN AT THIS POINT.
A POTENT NEGATIVELY TILTED SHORTWAVE TROUGH WILL EJECT NORTHEAST OUT
OF THE CENTRAL ROCKIES MONDAY NIGHT AND HAS BEEN PROJECTED TO DO SO
FOR SOME TIME. THERE ARE SOME STRENGTH AND TIMING DIFFERENCES
BETWEEN MEDIUM TO LONG RANGE MODELS...BUT THE GENERAL SCENARIO IS
SIMILAR. THE ECMWF CONTINUES TO PROJECT A STRONGER WAVE THAT EJECTS
INTO THE PLAINS SOONER THAN THE GFS SOLUTION. SURFACE PRESSURE
GRADIENTS WILL INCREASE ALONG WITH INCREASED MIXING AND WE COULD BE
GETTING CLOSE TO WIND ADVISORY WITH HEALTHY WIND FROM THE
SOUTH...ESPECIALLY IN THE WESTERN CWA. MODELS GENERALLY PRODUCE THE
NOSE OF THE LOW-LEVEL JET WELL NORTH OF THE CWA...ALONG WITH THE
BEST MID TO UPPER LEVEL FORCING TO THE NORTH AS WELL. AT THE
SURFACE...BY MONDAY EVENING...THE DRY LINE SHOULD STILL BE WELL TO
THE WEST OF THE CWA...WHILE A WARM FRONT IS EXPECTED TO HAVE PASSED
TO THE NORTHEAST OF THE CWA BY THEN. SEVERE PARAMETERS SUGGEST
POSSIBLE SEVERE WEATHER NEAR THESE BOUNDARIES...BUT WE MAY WIGGLE
OUT OF MOST OF THE SEVERE WEATHER BY BEING BETWEEN THESE BOUNDARIES
WHILE SEVERE WEATHER INITIATES TOWARD EVENING...GIVEN THAT SOUNDINGS
SUGGEST WE WILL BE TOO CAPPED TO PRODUCED MUCH OF ANYTHING IN THE
REGION UNTIL LATE AFTERNOON AND QUITE LIKELY IN THE EVENING...AND
FOR THIS REASON...I HAVE ALL BUT PULLED CHANCES OF PRECIPITATION
FROM MONDAY AFTERNOON...SAVE PERHAPS THE FAR NORTHEASTERN CORNER OF
THE CWA IF THE WARM FRONT DOES NOT GET OUT OF THE CWA FAST
ENOUGH...AND HAVE LIMITED THAT SMALL AREA TO LATE
AFTERNOON...DESPITE THE FACT THAT THE LATEST ECMWF PAINTS SOME QPF
OVER THE NORTHWEST. THIS DOES NOT LOOK PROBABLE AS IT APPEARS THAT
THE WARM FRONT SHOULD CLEAR THE CWA BEFORE CONVECTION BEGINS AND
THERE IS NO OTHER FOCUS FOR CONVECTION IN THE AFTERNOON TO REALLY
GET THINGS GOING FROM WHAT IT LOOKS LIKE FOR NOW. THIS LOOKS LIKE A
SCENARIO WHERE WE MAY WIND UP GETTING SOME NOCTURNAL HIGH PLAINS
CONVECTION AS THE THETA E AXIS WILL MOVE FROM WEST TO EAST ACROSS
THE CWA BETWEEN 03Z AND 08Z TUESDAY (MONDAY EVENING)...BUT THIS MAY
BE MORE OF A WEAKER LEFTOVER EVENT...GIVING US ELEVATED
STRONGER/HEAVY RAINER STORMS...BUT PERHAPS NO LONGER SEVERE. I AM
NOT CONFIDENT ENOUGH TO PULL SEVERE POTENTIAL OUT OF THE HWO...AS
TIMING DIFFERENCES COULD MAKE A HUGE DIFFERENCE...AND BEING SO FAR
OUT IN THE FORECAST...IT WOULD BE PRUDENT TO KEEP SEVERE POTENTIAL
MENTIONED IN THE HWO.
AFTER THE WAVE PASSES MONDAY NIGHT...THERE WILL BE LITTLE MORE
CHANCE OF PRECIPITATION FOR A COUPLE OF DAYS WITH RIDGING TAKING
PLACE. TUESDAY COULD BE GETTING CLOSE TO RED FLAG POTENTIAL IN THE
FAR WESTERN CWA WITH RELATIVE HUMIDITY POSSIBLY GETTING NEAR 20
PERCENT AND WEST WINDS APPROACHING SUSTAINED 20 MPH. THE ECMWF
INDICATES A SMALL PERTURBATION RIDING THE RIDGE BY WEDNESDAY NIGHT
ALONG OUR SOUTHERN FRINGE WITH PERHAPS THE AID OF SOME CONVERGENCE
AT 850 MB...BUT EVEN WITH QPF ADVERTISED BY THE ECMWF...PROBABILITY
OF PRECIPITATION FOR RUSSEL AND CONCORDIA ARE AROUND 20
PERCENT...AND LOWER THAN THIS IN OUR CWA TO THE NORTH. FOR THE REST
OF THE EXTENDED...I LEFT LOW CHANCES OF PRECIPITATION AS FLOW COULD
CONTAIN POTENTIAL SMALL WAVES OF ENERGY...ALTHOUGH TEMPERATURES WILL
REMAIN WELL ABOVE NORMAL.
&&
.PREV DISCUSSION... /ISSUED 1237 PM CDT FRI MAR 23 2012/
AVIATION...18Z KGRI TAF. A VERY QUIET 24 HOURS ANTICIPATED
AVIATION WISE...WITH SURFACE BREEZES REMAINING LIGHT AND VARIABLE
THROUGH THIS EVENING AND THEN TRANSITIONING TO LIGHT AND
SOUTHWESTERLY INTO SATURDAY MORNING.
CLOUD WISE...COULD EASILY SEE A FEW HOURS OF SCATTERED CUMULUS
BASED IN THE 4000-5000 FT AGL RANGE THIS AFTERNOON...BUT THIS
SHOULD DISSIPATE BY SUNSET. ONLY MINOR CONCERN IS POSSIBILITY OF
LIGHT FOG DEVELOPMENT MAINLY A FEW HOURS EITHER SIDE OF SUNRISE
SATURDAY MORNING...BUT THE SETUP FOR WIDESPREAD FOG DOES NOT
APPEAR THAT FAVORABLE. CONFIDENCE IS LOW ENOUGH IN FOG FORMATION
TO LEAVE PREVAILING VISIBILITY VFR AT THIS TIME...BUT SUPPOSE A
BRIEF PERIOD OF MVFR IS NOT COMPLETELY OUT OF THE QUESTION.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM/AVIATION...PFANNKUCH
LONG TERM...HEINLEIN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1237 PM CDT FRI MAR 23 2012
.UPDATE...MADE VERY LITTLE CHANGE TO AFTERNOON FORECAST...MAINLY
JUST THE USUAL MINOR TWEAKS TO WIND/SKY/DEWPOINT TRENDS. GAVE HIGH
TEMPS A VERY SLIGHT NUDGE UPWARD ACROSS MOST OF THE CWA...WITH A
BIT MORE COVERAGE OF READINGS AT/JUST ABOVE 70 ANTICIPATED BY MID
AFTERNOON. JUST STARTING TO SEE THE FIRST SIGNS OF SHALLOW
BOUNDARY LOWER CUMULUS DEVELOPMENT ACROSS MAINLY CENTRAL/SOUTHEAST
PORTIONS OF THE CWA...BUT ANTICIPATE MOST AREAS TO SEE NO MORE
THAN SCATTERED COVERAGE OF THESE CLOUDS...ALTHOUGH FAR SOUTHEAST
AREAS AROUND BELOIT/HEBRON COULD POTENTIALLY AVERAGE PARTLY TO
MOSTLY CLOUDY FOR AT LEAST A FEW HOURS WITH GREATER CUMULUS
DEVELOPMENT DOWN THAT WAY. LAST FEW HRRR RUNS HAVE ACTUALLY HINTED
AT SOME SPRINKLE POTENTIAL DOWN IN THESE SOUTHEAST AREAS THIS
AFTERNOON...BUT AT THIS POINT EXPECTING CUMULUS TO REMAIN SHALLOW
ENOUGH TO KEEP THIS AT BAY.
&&
.AVIATION...18Z KGRI TAF. A VERY QUIET 24 HOURS ANTICIPATED
AVIATION WISE...WITH SURFACE BREEZES REMAINING LIGHT AND VARIABLE
THROUGH THIS EVENING AND THEN TRANSITIONING TO LIGHT AND
SOUTHWESTERLY INTO SATURDAY MORNING.
CLOUD WISE...COULD EASILY SEE A FEW HOURS OF SCATTERED CUMULUS
BASED IN THE 4000-5000 FT AGL RANGE THIS AFTERNOON...BUT THIS
SHOULD DISSIPATE BY SUNSET. ONLY MINOR CONCERN IS POSSIBILITY OF
LIGHT FOG DEVELOPMENT MAINLY A FEW HOURS EITHER SIDE OF SUNRISE
SATURDAY MORNING...BUT THE SETUP FOR WIDESPREAD FOG DOES NOT
APPEAR THAT FAVORABLE. CONFIDENCE IS LOW ENOUGH IN FOG FORMATION
TO LEAVE PREVAILING VISIBILITY VFR AT THIS TIME...BUT SUPPOSE A
BRIEF PERIOD OF MVFR IS NOT COMPLETELY OUT OF THE QUESTION.
&&
.PREV DISCUSSION... /ISSUED 450 AM CDT FRI MAR 23 2012/
SHORT TERM...TODAY THROUGH 12Z MONDAY...A PLEASANT END OF THE
WEEK AND UPCOMING WEEKEND ARE IN STORE FOR THE LOCAL AREA AS AN
UPPER LEVEL RIDGE OF HIGH PRESSURE IS EXPECTED TO BUILD ACROSS THE
CENTRAL AND NORTHERN PLAINS BEHIND THE DEPARTING UPPER LEVEL LOW.
IN THE NEAR TERM...EXPECT A FEW LIGHT SHOWERS OR SPRINKLES TO
CONTINUE ACROSS THE EASTERN FRINGES OF THE FORECAST AREA THROUGH
THE EARLY MORNING HOURS...WITH LITTLE TO NO ADDITIONAL
ACCUMULATION EXPECTED. THIS FINAL BAND OF PRECIPITATION HAS BEEN
WEAKENING FOR THE PAST SEVERAL HOURS...AND IS EXPECTED TO
COMPLETELY DISSIPATE OVER THE NEXT HOUR OR TWO...WITH CLEARING
SKIES EXPECTED ACROSS THE LOCAL AREA BY MID MORNING. IN THE
MEANTIME...EXPECT PATCHY FOG DEVELOPMENT TO CONTINUE AHEAD OF
SUNRISE...AS LIGHT WINDS AND MOIST SOILS HAVE ALREADY RESULTED IN
SEVERAL OBSERVATION SITES TEMPORARILY FALLING TO BELOW 5 MILES
VISIBILITY THE PAST FEW HOURS. WHILE WIDESPREAD DENSE FOG IS NOT
EXPECTED...WOULD NOT BE SURPRISED TO SEE SOME PATCHY DENSE
FOG...ESPECIALLY IN LOW LYING AREAS...TOWARDS SUNRISE. THE GOOD
NEWS...HOWEVER...IS THAT ANY FOG THAT DOES DEVELOP IS EXPECTED TO
BE SHORT LIVED...WITH A BEAUTIFUL AFTERNOON EXPECTED ACROSS THE
REGION. WITH LIGHT WINDS...AMPLE SUNSHINE...AND REBOUNDING TEMPS
ALOFT...WENT AHEAD AND NUDGED UP AFTERNOON HIGHS A COUPLE OF
DEGREES...WITH MOST LOCATIONS EXPECTED TO TOP OUT NEAR 70
DEGREES...OR NEARLY 15 DEGREES ABOVE THE NORMAL HIGH FOR MID/LATE
MARCH.
WINDS WILL BEGIN TO SHIFT SOUTHERLY...ALBEIT REMAIN LIGHT ON
SATURDAY...AS THE SURFACE RIDGE OF HIGH PRESSURE ACROSS THE REGION
THIS MORNING CONTINUES TO PUSH FURTHER EAST. THIS SOUTHERLY WIND
COMPONENT WILL AID IN POTENTIAL MORNING FOG DEVELOPMENT THE NEXT
COUPLE OF MORNINGS...AND OPTED TO INCREASE COVERAGE OF PATCHY
MORNING FOG COVERAGE FOR THE UPCOMING WEEKEND. EVEN
SO...TEMPERATURES ALOFT WILL CONTINUE TO WARM...AND WITH AMPLE
SUNSHINE AND GOOD MIXING EXPECTED DURING THE AFTERNOON HOURS...
EXPECT HIGH TEMPERATURES TO TOP OUT NEAR 80 DEGREES BOTH
AFTERNOONS. WINDS ARE NOT EXPECTED TO BE AN ISSUE ON
SATURDAY...BUT DO INCREASE A BIT SUNDAY AFTERNOON IN RESPONSE TO A
TROUGH OF LOW PRESSURE BUILDING TO OUR WEST. EVEN SO...RELATIVE
HUMIDITIES APPEAR TO REMAIN HIGH ENOUGH THAT FIRE WEATHER
CONDITIONS DO NOT APPEAR TO BE A MAJOR CONCERN AT THIS POINT IN
TIME.
LONG TERM...12Z MONDAY THROUGH THURSDAY.
STARTING OFF THE LONG TERM...THE GFS AND THE ECMWF ARE IN FAIRLY
GOOD AGREEMENT MONDAY MORNING WITH THE POSITION OF AN UPPER LEVEL
TROUGH ACROSS QUEBEC AND THE EAST COAST...A RIDGE ACROSS THE CENTRAL
CONUS...AND A SECONDARY TROUGH AXIS STRETCHING FROM WASHINGTON TO
NEVADA. AT THE SURFACE...HIGH PRESSURE BUILDS ACROSS ONTARIO...WHILE
A LOW PRESSURE SYSTEM DEVELOPS ACROSS THE NORTHERN ROCKIES.
AS THE SURFACE LOW SLIDES NORTHEAST...A TIGHT PRESSURE GRADIENT WILL
FORM ACROSS THE PLAINS. WITH MODELS HINTING AT SUCH A TIGHT
GRADIENT...AND TO COLLABORATE WITH NEIGHBORING OFFICES...DECIDED TO
INCREASE WINDS ON MONDAY AFTERNOON TO JUST NEAR WIND ADVISORY
CRITERIA.
BY MONDAY NIGHT...THE SECONDARY TROUGH AXIS WILL BEGIN TO SLIDE INTO
THE REGION. THE LATEST RUN OF THE ECMWF HAS NOW COME INTO AGREEMENT
WITH THE GFS...POSITIONING THE CLOSED OFF 500 MB LOW OVER WESTERN
SOUTH DAKOTA BY MONDAY NIGHT. THUNDERSTORMS WILL REMAIN POSSIBLE
DURING THE AFTERNOON AND EVENING HOURS ON MONDAY AS AMPLE MOISTURE
AND MUCAPE VALUES NEAR 1500 TO 2000 J/KG REMAIN OVER THE FORECAST
AREA. POSITIONING OF THE DRY LINE WILL COME INTO QUESTION AS BOTH
THE GFS AND THE ECMWF KEEP THE DRY LINE TO THE WEST UNTIL AT LEAST
0Z. DECIDED TO GO WITH A MENTION OF THUNDERSTORMS DURING THE
AFTERNOON HOURS...BUT THE BULK OF THE PRECIPITATION LOOKS TO ARRIVE
DURING THE OVERNIGHT HOURS.
BY TUESDAY...UPPER LEVEL RIDGING WILL RETURN TO THE PLAINS...AND DRY
AIR WILL MOVE INTO THE REGION. FIRE WEATHER MIGHT BE A CONCERN ON
TUESDAY...DEPENDING ON THE LOCATION AND MAGNITUDE OF ANY
PRECIPITATION THAT FALLS MONDAY NIGHT. CURRENTLY...MODELS SOUNDINGS
INDICATE GOOD BOUNDARY LAYER MIXING DURING THE DAY ON TUESDAY TO AT
LEAST 850 MB...ALSO HELPING DRY THINGS OUT. WITH THIS
SOLUTION...DEWPOINTS NEED TO BE LOWERED BY AS MUCH AS 5 TO 10
DEGREES IN SOME LOCATIONS. FOR NOW DECIDED AGAINST LOWERING DEWPOINTS
BY THIS MUCH...AS IT REMAINS DAY 4 AND PRECIPITATION CHANCES ON
MONDAY WILL GREATLY AFFECT DEWPOINTS ON TUESDAY. HOWEVER...THAT
BEING SAID...SHOULD THE GFS SOLUTION VERIFY...RELATIVE HUMIDITY
VALUES ACROSS THE WESTERN PORTION OF THE CWA...WILL LIKELY BE WELL
BELOW 20 PERCENT.
TOWARDS THE END OF THE LONG TERM...BOTH THE GFS AND THE ECMWF
SUGGEST A MID LEVEL SHORT WAVE AND WEAK SURFACE LOW PRESSURE SYSTEM
WILL PUSH ACROSS CENTRAL PLAINS...CREATING A CHANCE FOR
PRECIPITATION THURSDAY NIGHT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE/AVIATION...PFANNKUCH
SHORT TERM...ROSSI
LONG TERM...SALTZMAN
AREA FORECAST DISCUSSION
NWS BISMARCK ND
323 PM CDT FRI MAR 23 2012
.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT...
NO SIGNIFICANT DIFFERENCE IN MODEL SOLUTIONS IN THE SHORT TERM
PERIODS AND USED A BLEND OF THE MODELS FOR THE GRIDS.
BIGGEST CONCERN IN EARLY FORECAST PERIODS IS POSSIBLY OF FOG REDEVELOPING
RAPDILY TONIGHT SHORTLY AFTER SUNDOWN. HRRR AND LAMP DATA
INDICATES A VERY SHARP LINE OF STRATUS AND FOG DEVELOPING ACROSS
SOUTH CENTRAL AND EAST CENTRAL NORTH DAKOTA BUT DREW THE
LINE SOMEWHAT FARTHER WEST AND INCLUDED BISMARCK...MANDAN AND MINOT
IN THE FOG. NO ADVISORY AT THIS TIME AS A COLD FRONT WILL PUSH
THROUGH THE AREA FROM WEST TO EAST BY MORNING PROMOTING MIXING.
SURFACE LOW WILL MOVE EAST OF AREA ON SATURDAY WITH NORTHWEST
WINDS DEVELOPING ACROSS THE REGION. RELATIVE HUMIDITIES SHOULD NOT
DECREASE TO POINT OF CAUSING FIRE WEATHER ISSUES. SATURDAY HIGH
PRESSURE MOVES EAST ACROSS SOUTH CENTRAL CANADA WITH COOL
NORTHERLY FLOW OVER THE AREA.
.LONG TERM...SUNDAY THROUGH FRIDAY...
THE HIGHLIGHT OF THE EXTENDED FORECAST IS THE STORM SYSTEM FORECAST
TO IMPACT THE NORTHERN PLAINS LATE MONDAY INTO TUESDAY...AND A BREAK
FROM FIRE WEATHER HEADLINES WITH SLIGHTLY COOLER
TEMPERATURES...ALBEIT STILL ABOVE NORMAL READINGS.
IN REGARDS TO THE DETAILS...A RELATIVELY COOL SUNDAY IS FORECAST
ACROSS WESTERN AND CENTRAL NORTH DAKOTA WITH EASTERLY SURFACE FLOW
RESULTING STRONG SURFACE HIGH PRESSURE NEAR HUDSON BAY AND LEE SIDE
LOW PRESSURE. HIGHS ON SUNDAY SHOULD RANGE FROM THE MID TO UPPER 40S
ACROSS THE TURTLE MOUNTAINS THROUGH THE JAMES RIVER VALLEY...WITH
HIGHS NEAR 60 ACROSS THE SOUTHWEST. DESPITE EASTERLY WINDS OF 20 TO
30 MPH...CRITICAL FIRE WEATHER CONDITIONS ARE NOT ANTICIPATED AS A
RESULT OF COOLER TEMPERATURES YIELDING AFTERNOON MINIMUM RH VALUES
IN THE 30 TO 40 PERCENT RANGE.
LEE SIDE CYCLOGENESIS INCREASES LATE MONDAY AFTERNOON AND INTO THE
NIGHT AS THE STRONG UPPER LEVEL WAVE FORECAST TO COME ON SHORE INTO
CALIFORNIA SUNDAY NIGHT PROPAGATES NORTHEAST TOWARDS THE NORTHERN
PLAINS. SOUTH-EASTERLY LOW LEVEL FLOW IS ALSO FORECAST TO INCREASE
DURING THIS TIMEFRAME AS A RESULT OF THE CYCLOGENESIS WITH GULF
MOISTURE TRANSPORT INTO THE NORTHERN PLAINS AS PWATS CLIMB INTO THE
0.75 TO 1.0 INCH RANGE BY MONDAY NIGHT. GIVEN THE LOW LEVEL WARM AIR
ADVECTION REGIME ASSOCIATED WITH THE SOUTHERLY FLOW...CAPPING SHOULD
PREVENT CONVECTIVE INITIATION THROUGH THE AFTERNOON...WITH A MORE
FAVORED AREA FOR DEVELOPMENT DURING THE AFTERNOON AND EARLY EVENING
CLOSER TO THE SURFACE WARM FRONT ACROSS SOUTH DAKOTA.
HOWEVER...CONVECTIVE CHANCES DO INCREASE MONDAY NIGHT AS THE MAIN
UPPER LEVEL WAVE APPROACHES WITH A STRENGTHENING LOW LEVEL JET AND
STEEP MID LEVEL LAPSE RATES. OVERALL ELEVATED CAPE IS LESS AND
FURTHER SOUTH TODAY COMPARED TO YESTERDAY. HOWEVER...ISOLATED
MARGINAL SEVERE HAIL WITH ELEVATED STORMS MONDAY NIGHT IS POSSIBLE
GIVEN THE AMPLE SHEAR PROFILES AND MID LEVEL LAPSE RATES.
THE UPPER LEVEL LOW IS FORECAST TO CLOSE OFF ACROSS NORTHEAST SOUTH
DAKOTA TUESDAY MORNING WITH WRAP AROUND PRECIPITATION ASSOCIATED
WITH THE TROWAL/DEFORMATION ZONE CONTINUING ACROSS MUCH OF WESTERN
AND CENTRAL NORTH DAKOTA DURING THE DAY ON TUESDAY. AT THIS TIME ALL
PRECIPITATION APPEARS TO BE RAIN...WITH A SLIGHT CHANCE FOR SOME
FLAKES TO MIX IN LATE TUESDAY EVENING AS COLDER AIR IS DRAWN INTO
THE SYSTEM. TUESDAY ALSO LOOKS TO BE WINDY...ESPECIALLY ACROSS THE
SOUTHWEST AND SOUTH CENTRAL GIVEN STRONG ISALLOBARIC FORCING ON THE
BACKSIDE OF THE LOW COUPLED WITH COLD AIR ADVECTION AND GOOD LOW
LEVEL MIXING. GIVEN THE STRENGTH OF THE WIND FIELD TUESDAY AFTERNOON
INTO THE EVENING...THE UPCOMING MODEL CYCLES WILL HAVE TO BE
MONITORED CLOSELY IF ANY SNOW WILL BE ABLE TO COUPLE WITH THE WINDS
TO CREATE POSSIBLE TRAVEL PROBLEMS. HOWEVER...THE 23/12 UTC
DETERMINISTIC SUITE IS SLIGHTLY COOLER COMPARED TO YESTERDAY...YET
WOULD STILL FAVOR ALL RAIN. IN THE WAKE OF THE TUESDAY SYSTEM...THE
UPPER LEVEL CENTRAL CONUS RIDGE IS FORECAST TO RE-AMPLIFY WITH ABOVE
NORMAL TEMPERATURES FAVORED FOR THE REMAINDER OF THE EXTENDED.
&&
.AVIATION...
THE LOW LEVEL STRATUS FIELD THAT WAS IN PLACE ACROSS MUCH OF WESTERN
AND CENTRAL NORTH DAKOTA THIS MORNING HAS ERODED AND LIFTED AS A
STRATOCUMULUS FIELD THIS AFTERNOON. HOWEVER...HIGH RESOLUTION MODEL
GUIDANCE IS SUGGESTING THE STRATUS FIELD TO FILL IN AND THE FOG TO
RETURN AFTER SUNSET THIS EVENING. THIS SEEMS PLAUSIBLE WITH LITTLE
AIRMASS CHANGE ACROSS MUCH OF THE AREA TONIGHT UNTIL COLD FRONT
PUSHES THROUGH THE AREA BETWEEN 10-15 UTC SATURDAY MORNING.
THEREFORE...HAVE INCLUDED STRATUS REFORMATION AND POSSIBLE FOG
DEVELOPMENT INTO THE KMOT...KBIS AND KJMS TAF SITES....WHILE THE
WESTERN TAF SITES OF KDIK AND KISN MAY REMAIN WEST OF THE STRATUS
FIELD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HW
LONG TERM....PJA
AVIATION...PJA
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
132 PM EDT FRI MAR 23 2012
.SYNOPSIS...
A SLOW MOVING UPPER LEVEL LOW PRESSURE SYSTEM WILL PUSH INTO THE
REGION BY SATURDAY. THIS LOW WILL THEN SLIDE OFF TO THE SOUTHEAST
SUNDAY WITH HIGH PRESSURE BUILDING BACK IN EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LEVEL LOW IS EVIDENT ON WATER VAPOR IMAGERY SPINNING ACROSS
SOUTHEAST MISSOURI THIS MORNING. AS THE LOW PUSHES SLOWLY EAST
THROUGH THE DAY...BANDS OF SHOWERS ROTATING UP THROUGH THE MID
OHIO VALLEY WILL ALSO SLOWLY WORK THEIR WAY EAST ACROSS MUCH OF
OUR AREA. THE EASTWARD PROGRESSION HAS BEEN RATHER SLOW THOUGH AND
THE LATEST RUC SEEMS TO BE PICKING UP ON THIS. WILL THEREFORE KEEP
HIGHEST POPS MAINLY ACROSS OUR WEST THROUGH A GOOD PART OF THE
DAY. LIGHTNING HAS BEEN FAIRLY SPOTTY SO FAR AND THINK CLOUDS WILL
HELP KEEP INSTABILITY SOMEWHAT MARGINAL...SO EXPECT MAINLY SHOWERS
WITH JUST A CHANCE OF THUNDER. CLOUDS AND PCPN SHOULD HELP KEEP
TEMPS FROM GETTING TOO OUT OF HAND WITH TEMPERATURES GENERALLY IN
THE UPPER 60S TO NEAR 70. OUR FAR NORTHEAST SHOULD SEE A LITTLE
MORE SUN THIS MORNING AND THIS MAY ALLOW THEM TO GET A BIT WARMER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
UPR LVL CLOSED LOW WILL CONTINUE TO SLOWLY INCH ITS WAY EAST
OVERNIGHT. COLD FRONT AHEAD OF THIS FEATURE WILL OCCLUDE AND WILL
MOVE ENE THROUGH THE AREA. BEST CHANCES FOR PCPN WILL BE ACRS
THE ERN ZONES EARLY ON. SOME OF THE MESOSCALE MODELS INDICATE THAT
LIKELY POPS MAY OCCUR ACRS THE SWRN SECTIONS THIS EVENING/OVERNIGHT AS
OCCLUDED FRONT PUSHES THROUGH. HAVE DECIDED TO LEAVE HIGH CHANCE
IN THIS AREA ATTM GIVEN LOW CONFIDENCE. HAVE USED A BLEND OF RAW
MODEL DATA TO COME UP WITH OVERNIGHT LOWS...WHICH SHOULD RANGE
FROM THE LOWER 50S SW TO THE UPPER 50S NE.
FOR SATURDAY INTO SATURDAY NIGHT...UPR LVL CLOSED LOW IS FORECAST
TO PIVOT ESE THROUGH THE OHIO VALLEY. ATTM...A WEAK SFC TROF AND
SFC LOW WILL TREK ACRS THE REGION. LOW LEVEL FORCING WILL BE WEAK
AT BEST...BUT MODELS INDICATE THAT A ROTATING VORT LOBE MAY
PROVIDE THE BEST UPR LVL SUPPORT ACRS THE SWRN ZONES. THUS...HAVE
GONE WITH CHANCE POPS EXCEPT ACRS THE SWRN ZONES WHERE LIKELY POPS
WILL BE USED. BEST CHANCE OF THUNDER WILL OCCUR DURING THE HEAT OF
THE DAY WHEN LOW LEVEL LAPSE RATES WILL BE THE GREATEST. PCPN
SHOULD DECREASE SATURDAY EVENING AS UPR LVL PULLS AWAY AND
INSTABILITY DROPS OFF. TEMPERATURES...ALTHOUGH COOLER...WILL STILL
BE ABOVE NORMAL DESPITE THE UPR LVL CLOSED LOW. HIGHS WILL RANGE
FROM THE MID TO UPPER 60S. LOWS WILL DROP INTO THE UPPER 40S TO
THE LOWER 50S.
FOR SUNDAY INTO SUNDAY NIGHT...ECMWF AND GFS DEPICT A DIGGING MID
LVL TROF WHICH WILL PUSH INTO SE CANADA/NRN NEW ENGLAND BY MONDAY
MORNING. THIS SYSTEM WILL PUSH A COLD FRONT SOUTH THROUGH THE
REGION SUNDAY/SUNDAY EVENING. WILL HOLD ON TO LOW CHANCES POPS
WITH FRONTAL PASSAGE. DRIER AIR AND CLEARING SKIES LATE SUNDAY
NIGHT WILL MARK THE BEGINNING OF A COOLING TREND.
FOR MONDAY INTO MONDAY NIGHT...CANADIAN HIGH PRESSURE WILL BUILD
SOUTHWARD INTO THE GREAT LAKES AND OHIO VALLEY. CAA WILL BRING
TEMPERATURES DOWN CLOSER TO NORMALS FOR LATE MARCH. WITH CLEAR
SKIES MONDAY NIGHT...SOME GUIDANCE SUGGESTS THAT LOWS MAY DROP
BELOW FREEZING...ESPECIALLY ACRS NRN AND ERN SECTIONS. THIS COULD
POSE A PROBLEM GIVEN THAT VEGETATION IS WELL AHEAD OF SCHEDULE DUE
TO THE VERY UNSEASONABLY WARM WEATHER THAT WE HAVE EXPERIENCED.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS THE REGION THROUGH
TUESDAY. THE NEXT SYSTEM WILL BEGIN TO BRING SHOWERS AND
THUNDERSTORMS INTO WESTERN PORTIONS OF THE FA LATE TUESDAY NIGHT
WITH A BETTER CHANCE OF THUNDERSTORM ACTIVITY ON WEDNESDAY. A COLD
FRONT WILL MOVE THROUGH WEDNESDAY NIGHT AND PRECIPITATION WILL END
ACROSS THE FA BY THURSDAY MORNING.
TEMPERATURES WILL WARM ONCE AGAIN BY WEDNESDAY WITH 70S EXPECTED.
TEMPERATURES WILL COOL BEHIND THE FRONT ON THURSDAY.
&&
.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
UPPER LEVEL LOW OVER SOUTHERN MISSOURI WILL PUSH SLOWLY EAST
ACROSS THE LOWER OHIO VALLEY THROUGH SATURDAY. AHEAD OF
THIS...BANDS OF SHOWERS AND PERHAPS A FEW THUNDERSTORMS WILL
ROTATE UP ACROSS OUR REGION. THE INITIAL BAND IS CONTINUING TO
AFFECT MAINLY THE WESTERN PORTIONS OF OUR AREA AND WILL CONTINUE
TO DO SO THROUGH THE AFTERNOON. AS IT PROGRESSES SLOWLY EAST...IT
SHOULD EVENTUALLY REACH CENTRAL OHIO TOWARD LATE AFTERNOON.
INSTABILITY REMAINS MARGINAL WITHIN THIS BAND SO THINK THUNDER
WILL REMAIN FAIRLY ISOLATED.
BETTER INSTABILITY BACK TO OUR SOUTHWEST IS LEADING TO MORE
WIDESPREAD THUNDERSTORM ACTIVITY ACROSS SOUTHERN ILLINOIS AND WESTERN
KENTUCKY. THIS WAVE SHOULD EVENTUALLY PUSH EAST INTO OUR AREA
LATER TONIGHT BUT BY THAT TIME...INSTABILITY SHOULD ONCE AGAIN BE
MARGINAL AND WILL THEREFORE HOLD OFF ON MENTIONING THUNDER LATER
TONIGHT. JUST AHEAD OF THE LOW...THERE WERE SOME LOW CLOUDS AND
FOG THIS MORNING AND SOME OF THIS MAY REDEVELOP ACROSS OUR AREA
LATE TONIGHT. ANY FOG/LOWER CLOUDS SHOULD DISSIPATE THROUGH LATE
MORNING. EXPECT WIDESPREAD CU TO DEVELOP FROM LATE MORNING INTO
EARLY AFTERNOON AS UPPER LEVEL LOW APPROACHES. WILL ALSO LIKELY
SEE SOME SCATTERED SHOWER/THUNDERSTORM DEVELOPMENT TOWARD THE END
OF THE TAF PERIOD.
OUTLOOK...MVFR CEILINGS POSSIBLE AT TIMES THROUGH SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...JGL
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1254 PM CDT FRI MAR 23 2012
.DISCUSSION...
DENSE FOG VERY SLOWLY DECREASING THIS MORNING. WILL LET THE ADVISORY
EXPIRE AT 1000 AM...BUT STILL PLAN ON SOME DENSE FOG IN MAINLY NW IA
AND SW MN FOR AN HOUR OR TWO LONGER. OTHERWISE...ANOTHER
UNSEASONABLY WARM DAY AHEAD WITH VERY LITTLE WIND...SO VERY
PLEASANT. HIGHS FROM THE UPPER 60S TO LOWER 70S STILL LOOKS ON
TARGET. /08
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
OTHER THAN A SMALL PATCH OF IFR CEILINGS EAST OF THE BUFFALO RIDGE
VFR CONDITIONS ARE EXPECTED THROUGH ABOUT 6Z THIS EVENING. MAINLY
MVFR TYPE FOG IS ANTICIPATED TONIGHT HOWEVER NEAR AND EAST OF THE
BUFFALO RIDGE THERE WILL BE A BETTER CHANCE FOR THE DEVELOPMENT OF
IFR OR LIFR VISIBILITIES IN FOG WITH LIGHT WINDS AND RESIDUAL LOW
LEVEL MOISTURE. OTHERWISE...FROM ABOUT 15Z SATURDAY ON VFR
CONDITIONS WILL AGAIN PREVAIL. /08
&&
.PREV DISCUSSION.../ISSUED AT 416 AM CDT/
INITIAL CONCERN IS DENSE FOG WHICH HAS DEVELOPED ACROSS EASTERN
PORTIONS OF THE FORECAST AREA. HRRR HAD A DECENT HANDLE ON THE
DEVELOPMENT AREA THROUGH THE EARLY MORNING AND TRIES TO EXPAND THE
WESTERN EDGE OF THE FOG WESTWARD TO THE JAMES VALLEY THROUGH 13Z
BEFORE RAPID IMPROVEMENT IN VISIBILITY BETWEEN 15Z AND 17Z. NOT YET
SEEING ANY INDICATION OF MUCH WESTWARD PUSH INTO SOMEWHAT DRIER LOW
LEVEL AIR THOUGH...SO WILL LET DENSE FOG ADVISORY ISSUED EARLIER FOR
AREAS ALONG/EAST OF HURON-SALEM-AKRON LINE STAND. FOG EXPECTED TO
LIFT DURING THE LATE MORNING...THOUGH MAY SEE SOME LINGERING STRATUS
IN EASTERN AREAS INTO THE EARLY AFTERNOON. BETWEEN THAT AND MID-UPPER
LEVEL CLOUDS CONTINUING TO WRAP AROUND SLOWLY DEPARTING UPPER LOW...
EASTERN COUNTIES SHOULD BE PARTLY SUNNY THROUGH THE AFTERNOON WITH
MORE SUNSHINE EXPECTED ALONG/WEST OF I-29. LIGHT WIND FLOW TODAY WILL
LIKELY NOT SCOUR OUT RESIDUAL LOW LEVEL MOISTURE IN THE EAST THOUGH
AND COULD SEE SOME REDEVELOPMENT OF FOG LATE TONIGHT/EARLY SATURDAY
AND HAVE ADDED PATCHY FOG TO AREAS ALONG/EAST OF THE BUFFALO RIDGE
AND IOWA GREAT LAKES.
OTHERWISE BUILDING UPPER RIDGE STILL ON TRACK TO BRING DRY WEATHER
FOR THE WEEKEND. GFS/NAM NOW STRONGER THAN THEIR RUNS FROM 24 HOURS
AGO WITH NORTHERN STREAM WAVE TRACKING ACROSS CANADA THIS WEEKEND.
THIS ALLOWS FRONT AND TRAILING RELATIVELY COOLER AIRMASS TO PUSH
FARTHER SOUTH THROUGH THE UPPER MIDWEST...SIMILAR TO WHAT ECMWF/GEM
WERE SHOWING YESTERDAY MORNING. SATURDAY SHOULD BE QUITE MILD OVER
THE ENTIRE CWA WITH HIGHS IN THE 70S...POSSIBLY HITTING 80 IN PARTS
OF THE MISSOURI VALLEY. FRONTAL BOUNDARY THEN SETS UP NORTHWEST TO
SOUTHEAST ACROSS THE CWA...MAKING TEMPERATURES A LITTLE MORE TRICKY
FOR SUNDAY INTO MONDAY. BOUNDARY WILL SEPARATE 50S AND LOWER 60S IN
MINNESOTA...FROM UPPER 70S-LOWER 80S IN NEBRASKA AND SOUTHWEST SOUTH
DAKOTA...AND THE GRADIENT LIKELY TO BE SOMEWHERE IN OUR CWA. FOR NOW
HAVE COOLED NORTHEAST AREAS FROM PREVIOUS FORECAST FOR SUNDAY/MONDAY
BUT GRADIENT MAY HAVE TO BE TIGHTENED FURTHER IF 925MB TEMPS...WHICH
RANGE FROM 7-9C IN SOUTHWEST MN TO THE LOWER 20S IN SOUTH CENTRAL
SD...PAN OUT FOR MONDAY AFTERNOON.
BOUNDARY COULD ALSO BE FOCUS FOR A FEW SHOWERS OR THUNDERSTORMS LATE
SUNDAY NIGHT AND MONDAY AS LOW LEVEL JET INCREASES AHEAD OF THE NEXT
SYSTEM. INSTABILITY ON THE WEAK SIDE ALONG/NORTHEAST OF THE BOUNDARY
WITH MORE FAVORABLE CAPE BUILDING INTO WARM SECTOR ACROSS SOUTHWEST
CWA MONDAY AFTERNOON...THOUGH PRETTY STOUT CAP REMAINS IN PLACE
THROUGH THE AFTERNOON SO KEEPING POPS ON THE LOW SIDE FOR DAYTIME
HOURS. BETTER CHANCE LOOKS TO BE MONDAY NIGHT AS BOTH GFS/ECMWF SHOW
POTENT MID-UPPER LEVEL WAVE CRASHING INTO THE RIDGE OVER THE EASTERN
DAKOTAS. WITH STRONG DYNAMIC LIFT AND VERY STRONG LOW-MID LEVEL WINDS
AROUND SOUTH SIDE OF DEEP LOW...MAY NOT TAKE MUCH TO PRODUCE DAMAGING
WIND GUSTS WITH ANY STORMS THAT DEVELOP/MOVE INTO THE MORE UNSTABLE
AIR ACROSS THE SOUTHWEST CWA MONDAY NIGHT.
QUICK MOVING COMPACT SYSTEM WILL SHIFT EAST OF THE AREA TUESDAY...
THOUGH COULD SEE SOME SHOWERS WRAP AROUND INTO MAINLY NORTHERN PARTS
OF THE AREA TUESDAY BEFORE DRIER AIR BUILDS IN AND PRECIP THREAT
SHIFTS EAST OF THE AREA TUESDAY NIGHT. WITH STRONG SURFACE LOW
PASSING TO OUR NORTH TUESDAY...LIKELY TO SEE STRONG SYNOPTIC SCALE
FLOW DEVELOP IN WELL-MIXED DEEP WESTERLY FLOW BEHIND THE FRONT.
UPPER RIDGING WILL BRING DRY WEATHER BACK TO THE AREA FOR WEDNESDAY
AND WEDNESDAY NIGHT...WITH UPPER TROUGH SET TO MOVE INTO THE NORTHERN
PLAINS LATE IN THE WEEK. DIFFERENCES IN TIMING AMONG THE MODELS SO
WILL HAVE JUST A SLIGHT CHANCE OF THUNDERSTORMS IN THE WESTERN CWA
THURSDAY...WITH BETTER CHANCE HOLDING OFF UNTIL THURSDAY NIGHT OR
FRIDAY...DEPENDING ON EVENTUAL TIMING. TEMPERATURES WILL REMAIN ON
THE MILD SIDE OF NORMAL...THOUGH LATTER PART OF THE FORECAST PERIOD
SHOULD BE COOLER THAN THE NEXT FEW DAYS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
152 PM EDT FRI MAR 23 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL TRACK EAST OUT OF THE MID MISSISSIPPI
VALLEY TODAY...THEN SOUTHEAST ACROSS THE TENNESSEE VALLEY ON
SATURDAY. BY MONDAY THE SYSTEM WILL BE OFF THE EAST COAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 130 PM EDT FRIDAY...
CONVECTION DEVELOPING IN UNSTABLE AIR THIS AFTERNOON ACROSS THE
WESTERN MOUNTAINS. ADJUSTED POPS AND TEMPERATURES FOR LATEST TRENDS.
AS OF 1140 AM EDT FRIDAY...
ADJUSTED THE ONSET OF CONVECTION AND RAISED TEMPERATURES A FEW
DEGREES THIS AFTERNOON. PLAYED EARLY POPS CLOSE TO HRRR THIS AFTERNOON.
ADJUSTMENTS MADE IN CLOUD COVER THIS AFTERNOON INTO TONIGHT.
AS OF 925 AM EDT FRIDAY...
THE UPPER LOW OVER THE PLAINS WILL MOVE SLOWLY EASTWARD THIS
AFTERNOON AND TONIGHT...THIS WILL PUSH AN OCCLUDED SURFACE FRONT
AND ASSOCIATED MOISTURE EASTWARD. THIS MORNING WRFARW-RNK AND NAM
BRINGS SOME CONVECTION INTO THE WEST THIS AFTERNOON AND SPREAD
STORMS EAST TONIGHT. EXPECT ISOLATED TO SCATTERED THUNDERSTORMS
IN THE AFTERNOON MAINLY WEST OF I77...THEN BETTER COVERAGE ANTICIPATED
AFTER 8PM/00Z TONIGHT. AS PREVIOUS SHIFT POINT OUT...THE THREAT
OF SEVERE THUNDERSTORMS...ESPECIALLY HAIL...INCREASES BY THIS
EVENING INTO SATURDAY AS THE UPPER LOW AND COLD POOL GET CLOSER. THE DAY2
CONVECTIVE OUTLOOK PLACES EAST OF THE MOUNTAINS IN A SLIGHT RISK
ON SATURDAY. MADE SOME MINOR ADJUSTMENTS IN ISC GRIDS FOR
TEMPERATURES...AND POPS FOR THIS AFTERNOON.
AS OF 400 AM EDT FRIDAY...
MODELS SIMILAR WITH TIMING OF APPROACHING OCCLUDED FRONT AND
ASSOCIATED PRECIPITATION. THERE MAY BE ISOLATED TO SCATTERED
THUNDERSTORMS IN THE AFTERNOON BUT THE BETTER PROBABILITY AND
COVERAGE OF PRECIPITATION WILL BE AFTER 8PM/00Z TONIGHT. THE
THREAT OF SEVERE THUNDERSTORMS...ESPECIALLY HAIL...INCREASES BY
THIS EVENING AS THE UPPER LOW AND COLD POOL GET CLOSER.
MADE ONLY MINOR ADJUSTMENTS FOR HIGHS TODAY. STAYED CLOSE TO LAMP
GUIDANCE. MILD DEW POINTS AND CLOUDS COVER WILL HOLD TEMPERATURES
UP TONIGHT. USED A BLEND OF BIAS CORRECTED MET/MAV GUIDANCE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 400 AM EDT FRIDAY...
STRONG CYCLONE WHICH HAS BEEN QUASI-STATIONARY OVER THE SOUTHERN
PLAINS WILL FINALLY TRACK EAST AND ACROSS THE MID ATLANTIC REGION
THIS WEEKEND. THIS FEATURE IS EXPECTED TO SLOWLY TREK ACROSS THE
AREA SATURDAY AND SUNDAY WITH SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS. INITIAL WAVE OF PRECIP SHOULD HAVE PASSED THROUGH THE
CWA BY 12 UTC...8AM SATURDAY...ASSOCIATED WITH THE OCCLUDED SURFACE
FRONT. WITH PASSAGE OF OCCLUSION...SHOULD SEE A BREAK IN THE PRECIP
WITH STRONG INDICATION THAT A DRY SLOT WILL WORK ACROSS THE FCST
AREA PRIOR TO ARRIVAL OF PRECIP UNDERNEATH THE UPPER LOW. IF THIS
BREAK IN PRECIP ASSOCIATED WITH THE DRY SLOT REVEALS ANY
CLEARING...THEN SOLAR INSOLATION LIKELY TO INCREASE INSTABILITY
ACROSS THE CWA INCREASING POTENTIAL FOR SEVERE STORMS. IF THIS TURNS
OUT TO BE THE CASE...WILL THEN NEED TO ENTERTAIN POSSIBILITY OF
SUPERCELLS PER INCREASING DEEP LAYER SHEAR AHEAD OF THE APPROACHING
UPPER VORTEX.
WILL DEFER TO THE STORM PREDICTION CENTER FOR GUIDANCE ON THIS
DEVELOPING SITUATION...BUT IT APPEARS THE GREATEST THREAT FOR SEVERE
WEATHER MAY RESIDE JUST SOUTH OF THE FCST AREA.
FOR SATURDAY NIGHT AND SUNDAY THE UPPER LOW IS PROGGED TO PASS
DIRECTLY OVER THE MID ATLANTIC REGION...THE CENTER OF THE LOW
SPIRALING EAST AND OFF THE COAST SUNDAY NIGHT. FOCUS SATURDAY NIGHT
THROUGH SUNDAY WILL BE FOR SCATTERED TO NUMEROUS SHOWERS AND
EMBEDDED THUNDERSTORMS...THE THREAT FOR PRECIP PERSISTING UNTIL THE
STORM SYSTEM PASSES EAST OF THE REGION SUNDAY NIGHT.
TEMPERATURES WILL TREND DOWNWARD OVER THE WEEKEND...SATURDAY BEING
THE WARMER OF THE TWO DAYS WITH READINGS IN THE 70S PENDING A BIT OF
SUN. SHAVE ABOUT 10 DEGREES OFF THE TMAX FOR SUNDAY COMPARED TO
SATURDAY...SUNDAY STILL TOPPING OUT 4-8 DEGREES ABOVE THE NORM.
QPF FOR THE ENTIRE EVENT...NOON FRIDAY THROUGH MIDNIGHT SUNDAY NIGHT
LOOKS TO BE ON THE ORDER OF ONE TO TWO INCHES...THE HIGHER AMOUNTS
FAVORING CONVEYOR BELT OF DEEPER MOISTURE THAT WILL RESIDE ON THE
NORTH SIDE OF THE CYCLONE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 400 AM EDT FRIDAY...
CYCLONE IS PROGGED TO BE WELL EAST OF THE AREA BY 12Z MONDAY...
BOOTED OUT TO SEA BY A STRONG NORTHERN STREAM TROF THAT WILL DIVE
SOUTHEAST ACROSS NEW ENGLAND FROM EASTERN CANADA. THE COMBINATION OF
THE EXITING CYCLONE AND TROF OVER NEW ENGLAND WILL BRING BREEZY
CONDITIONS TO THE AREA MONDAY AND MONDAY NIGHT...FOLLOWED BY A SUNNY
DRY DAY FOR TUESDAY. TEMPERATURES WILL BEGIN TO MODERATE
TUESDAY...WITH A MORE SIGNIFICANT REBOUND WEDNESDAY AS THE LOW LEVEL
FLOW BECOMES SOUTHWESTERLY. ATTM WILL MAINTAIN A DRY FORECAST FOR
MIDWEEK BUT WILL HAVE TO KEEP EYES ON FAST MOVING FRONT WHICH IS
PROGGED TO MOVE ACROSS THE OHIO VALLEY WEDNESDAY...POSSIBLY ARRIVING
ACROSS OUR THE MTNS AS EARLY AS WEDNESDAY AFTERNOON. THIS SOLUTION
IS ABOUT 12-18 HOURS FASTER THAN PREVIOUS MODEL RUNS.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1140 AM EDT FRIDAY...
THIS MORNING PATCHY FOG DISSIPATED QUICKLY...LEAVING PLENTY OF
SUNSHINE. CLOUDS WILL FILL IN FROM WEST TO EAST THIS AFTERNOON INTO
TONIGHT WITH CEILINGS LOWERING TONIGHT. MODERATE CONFIDENCE THAT
CEILINGS WILL REMAIN VFR AS THE PRECIPITATION BEGINS. AFTER 00Z
TONIGHT...THERE IS A CHANCE THAT BLF AND LWB MAY HAVE MVFR/IFR CEILINGS
AND VISIBILITIES WITH CONVECTION AND LOW CLOUDS.
MODELS BRING PRECIPITATION ASSOCIATED WITH THE CLOSED UPPER LOW
OVER THE MIDWEST INTO THE FORECAST AREA AFTER 00Z. MORE WIDESPREAD
RAIN IS EXPECTED SATURDAY THROUGH SUNDAY AS THE LOW MOVES EAST
THEN SOUTHEAST.
DRIER WEATHER AND VFR CONDITIONS ARE EXPECTED BEHIND THE SYSTEM
SUNDAY NIGHT THROUGH TUESDAY.
&&
.CLIMATE...
RECORD HIGH TEMPS FOR TODAY...
3/23
ROANOKE 82 IN 2007
LYNCHBURG 91 IN 2007
DANVILLE 86 IN 1966
BLUEFIELD 77 IN 2007
BLACKSBURG 80 IN 1966
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/KK
SHORT TERM...PM
LONG TERM...WP
AVIATION...AMS
CLIMATE...