Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 03/13/14
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1006 AM MDT TUE MAR 11 2014
.UPDATE...
&&
.SHORT TERM...FRONT CURRENTLY PUSHING SOUTH ACROSS PLAINS...
REACHED DENVER AT 15Z. NORTHERLY WINDS BEHIND FRONT...CURRENTLY
GUSTING IN THE 35 TO 40 MPH RANGE. WINDS STILL EXPECTED TO
INCREASE...WITH RUC AND HRRR INDICATING GUSTS OF 40 TO 50 MPH.
BLOWING DUST ADVISORY SEEMS REASONABLE FOR LINCOLN COUNTY. AT THIS
TIME...WINDS SHOULD REMAIN BELOW HIGH WIND CRITERIA. AS FOR SNOW
...MOUNTAIN AREAS SEEING ACCUMULATING SNOW AT THIS TIME. THERE MAY
BE A BIT OF A DECREASE LATER THIS MORNING AS SLIGHTLY DRIER AIR
MOVES OVER THE AREA. BUT A GOOD BATCH OF MOISTURE OVER WYOMING
SHOULD SPREAD BACK INTO THE MOUNTAINS. WILL CONTINUE WITH THE
CURRENT FORECAST TRENDS WITH ROUGHLY 3 TO 6 INCHES...NO
ADVISORIES AT THIS TIME. ACROSS PLAINS...SNOWING LIGHTLY NORTH OF
THE BORDER AT CHEYENNE AND KIMBLE. RADAR SHOWING SOME ECHOES
ACROSS NORTHERN LARIMER COUNTY NEAR THE WYOMING BORDER. SHOULD SEE
THE PRECIPITATION DEVELOP BEHIND THE FRONT WITHIN THE NEXT HOUR OR
SO AS THE LOWER LEVELS OF THE ATMOSPHERE GRADUALLY MOISTEN. WITH
TEMPERATURES FALLING BEHIND THE FRONT...THE PRECIPITATION WILL BE
MAINLY SNOW WITH SOME RAIN MIXED IN FOR A SHORT PERIOD OF TIME.
LATEST MODEL TRENDS INDICATING A 1 OR 2 INCH SNOWFALL FOR THE
DENVER AREA WITH AS MUCH AS 4 INCHES FOR THE PALMER DIVIDE.
INITIALLY THE SNOW SHOULD MELT BEFORE ANY ACCUMULATION OCCURS.
LESS ACCUMULATION ELSEWHERE DUE TO DOWNSLOPE COMPONENT. BLOWING
SNOW POSSIBLE WITH THE STRONG WIND AND ACCUMULATION. DON`T THINK
AN ADVISORY FOR SNOW AND BLOWING SNOW WILL BE NEEDED FOR THE
PALMER DIVIDE AT THIS TIME DUE TO THE INITIAL MELTING EXPECTED.
WILL CONTINUE TO MONITOR TO SEE IF ONE WILL BE NEEDED. SNOW TO END
FROM NORTH TO SOUTH DURING THE EVENING WITH SUBSIDENCE AND DRIER
AIRMASS. OVERALL...CURRENT FORECAST LOOK REASONABLE WITH SOME
ADJUSTMENTS DUE TO TIMING OF FRONT.
.AVIATION...FRONT MOVING ACROSS DIA WITH NORTHERLY WINDS GUSTING
TO 28 KTS. FRONT SHOULD BE MOVING INTO KBJC AND KAPA WITHIN THE
NEXT ONE HALF HOUR WITH WINDS SHIFTING TO THE NORTH AND INCREASING
TO 25 TO 30 KTS. SOME GUSTS TO 40 KTS POSSIBLE DURING THE
AFTERNOON. SNOW TO DEVELOP BY 18Z WITH MVFR CONDITIONS. IFR
CONDITIONS POSSIBLE WITH THE HEAVIER SNOW SHOWERS. SNOW EXPECTED
TO END BETWEEN 00Z AND 01Z WITH DECREASING WINDS. AT THIS TIME THE
FRONT RANGE AIRPORTS SHOULD SEE BETWEEN ONE AND TWO INCHES OF SNOW
ACCUMULATION. THERE IS A SLIGHT CHANCE THAT KAPA COULD RECEIVE
AROUND 3 INCHES IF CONVECTION IS A BIT MORE PRONOUNCED. STILL
EXPECTING VFR CONDITIONS WITH LIGHTER WINDS OVERNIGHT. AT THIS
TIME...FOG OR LOW CLOUDS ARE NOT EXPECTED TO DEVELOP.
&&
.PREV DISCUSSION... /ISSUED 420 AM MDT TUE MAR 11 2014/
SHORT TERM...STILL A COMPLEX WEATHER SCENARIO FOR THE FORECAST
AREA TODAY. BUT COLD...STRONG WINDS...AND SNOW STILL ON THE WAY.
PREFRONTAL WIND SHIFT IS ALREADY OCCURRING ACROSS THE NORTHEAST
PLAINS PER LATEST OBS. MAIN COLD FRONT HAD JUST PUSHED THROUGH
CASPER WYOMING SO THATS ON TRACK TO REACH THE BORDER SHORTLY
BEFORE DAYBREAK AND DENVER METRO AROUND 9 AM. BIG SURFACE
PRESSURE RISES ARE OCCURRING BEHIND THE FRONT AND INCREASING...SO
A SLIGHTLY EARLIER ARRIVAL IS POSSIBLE. WINDS WILL INCREASE WITH
AND JUST BEHIND THE FRONT WITH WIDESPREAD GUSTS OF 40 TO 55
MPH...STRONGEST ON THE EASTERN PLAINS. LOCATIONS AROUND LINCOLN
COUNTY HAVE BEEN DRIER THERE RECENTLY THAN ANYWHERE ELSE SO
BLOWING DUST WILL BE A CONCERN BEFORE ANY WIDESPREAD PRECIPITATION
THIS AFTERNOON...SO HAVE ISSUED A BLOWING DUST ADVISORY THERE.
WITH REGARD TO SNOWFALL...MOUNTAINS WERE ALREADY SEEING ONE BATCH
OF SNOW...BUT THIS WILL LIKELY DECREASE A BIT EARLY THIS MORNING
AS SOME TEMPORARILY DRIER AIR MOVES ACROSS. MORE WIDESPREAD SNOW
IS EXPECTED TO DEVELOP BEHIND THE FRONT PER UPSTREAM OBS. LOW/MID
LEVELS ARE INITIALLY DRY...SO LOOK FOR PRECIPITATION TO DEVELOP
WITHIN ABOUT 2-4 HOURS OF FRONTAL ARRIVAL. TEMPERATURES WILL BE
COLD ENOUGH FOR ALMOST ALL SNOW AND WILL GET COLDER THROUGH THE
DAY. THERE MAY BE A BIT OF LIGHT RAIN ON THE LEADING EDGE OF
PRECIP. SATELLITE SHOWS CONVECTION ASSOCIATED WITH UPPER LEVEL
COLD POOL NOW MOVING ACROSS NORTHERN UTAH AND WYOMING...WHICH WILL
REACH THE FRONT RANGE BY 18Z. THE COMBINATION OF UPSLOPE AND COLD
POOL ALOFT MEANS A MOISTENING AIRMASS WITH VERY STEEP LAPSE
RATES...SO CONVECTIVE POTENTIAL IS THERE. OVERALL...THINK THE
CONVECTIVE POTENTIAL WILL HELP OFFSET THE SPARSE MODEL QPF. ADDED
A LITTLE MORE SNOW TO THE NORTHEAST CORNER LATER THIS MORNING INTO
THE AFTERNOON BASED ON LATEST MESOSCALE MODEL OUTPUT AND BETTER
MOISTURE THERE...WHILE CUT BACK AMOUNTS ON THE DOWNSLOPE SIDE OF
THE CHEYENNE RIDGE GIVEN STRONG NORTHERLY FLOW IN PLACE. DENVER
AREA STILL EXPECTED TO SEE A 1-2 INCH SNOWFALL BUT STILL SOME
UNCERTAINTY FOR HIGHER OR LOWER AMOUNTS BASED ON CONVECTIVE
NATURE. THE MOST FAVORED LOCATION FOR SNOW IN THIS FLOW PATTERN
WOULD BE FOOTHILLS OF JEFFERSON/DOUGLAS COUNTIES AS WELL AS THE
PALMER DIVIDE...SO WILL GO WITH HEAVIER AMOUNTS OF 2-5 INCHES
POSSIBLE THERE. GIVEN THE STRONG WINDS...ALSO MENTIONED AREAS OF
BLOWING SNOW WHERE MORE THAN AN INCH OR TWO OF ACCUMULATION IS
EXPECTED. MOUNTAIN LOCATIONS SHOULD SEE STORM TOTALS MOSTLY IN THE
3-6 INCH RANGE.
SNOW WILL DECREASE LATE THIS AFTERNOON INTO EARLY EVENING FROM
NORTH TO SOUTH AS AIRMASS DRIES AND SUBSIDENCE BUILDS IN. SKIES
WILL THEN CLEAR OUT FOR OVERNIGHT. WINDS WILL DECREASE BY OR
SHORTLY AFTER SUNSET.
LONG TERM...MEDIUM AND LONG RANGE PORTIONS OF THE FORECAST
INCLUDE GENERALLY DRY AND MILD WEATHER AS A WESTERN U.S. RIDGE
PRODUCES WARM NORTHWESTERLY FLOW OVER COLORADO. ON WEDNESDAY AND
THURSDAY...THE UPPER RIDGE WILL BE HELD OVER COLORADO WHILE A
WEAK...CUTOFF LOW MEANDERS FROM SOUTHERN NEVADA TO CENTRAL NEW
MEXICO. OUR REGION WILL BE LEFT UNDER THE DEFORMATION REGION WITH
WEAK FLOW ALOFT. THE UPPER FEATURE SHOULD EVENTUALLY KICK OUT ONTO
THE SOUTHERN PLAINS BY ABOUT FRIDAY WITH LITTLE ADDITIONAL IMPACT
ON NORTHERN COLORADO WEATHER. FROM FRIDAY THROUGH
SATURDAY...NORTHWEST FLOW ALOFT WILL INCREASE OVER THE STATE AS
THE UPPER LOW DEPARTS. LATER ON SATURDAY...A WEAK SHORT WAVE
EMBEDDED IN THE NORTHWEST FLOW PATTERN IS FORECAST TO SLIDE OVER
THE STATE. THIS FEATURE WILL BRING A CHANCE OF SNOW TO THE
MOUNTAINS AND MAY BRING SOME PRECIPITATION TO THE PLAINS THROUGH
SATURDAY NIGHT. EACH OF THE SYNOPTIC MODELS HAVE VARIOUS IDEAS ON
THE TIMING OF THE SOUTHWESTERN CUTOFF LOW EJECTING AND SUBSEQUENT
PASSAGE OF UPPER TROUGH ACROSS COLORADO. FOR NOW HAVE FAVORED THE
GFS SOLUTION...AS THE CANADIAN AND ECMWF LOOK A LITTLE TOO FAST.
BEYOND THAT...MORE WESTERN U.S. RIDGING IS FORECAST WITH SUBSIDENT
NORTHWESTERLY FLOW EXPECTED OVER COLORADO. DRY WEATHER AND WARMER
TEMPERATURES WILL BE THE RESULT.
TEMPERATURE FORECASTS THROUGH THE PERIOD WERE A COMPROMISE BETWEEN
THE TOO WARM GFS MOS GUIDANCE AND CONSERVATIVE GENERALLY
CONSERVATIVE NUMBERS FROM ECMWF MOS GUIDANCE. FORECASTING THE
PRECIPITATION TYPE ON THE PLAINS IS GOING TO BE CHALLENGING AND
DEPEND ON THE TIME OF DAY OR NIGHT WHEN THE WEATHER SYSTEMS PASS
OVER THE AREA. DAYTIME PRECIPITATION WILL BE IN LIQUID FORM WHILE
EVENING AND OVERNIGHT TIME PERIODS WILL FAVOR SNOW OR A RAIN/SNOW
MIX.
AVIATION...STRONG COLD FRONT EXPECTED TO REACH THE FRONT RANGE
AIRPORTS AROUND 15Z...PERHAPS A BIT EARLIER AT KDEN. SOME STRATUS
AND POTENTIAL FOR MVFR CEILINGS TO DEVELOP BEHIND THE FRONT...THEN
SNOW WILL BECOME LIKELY BY 18Z-21Z WITH IFR CONDITIONS IN HEAVIER
SNOW SHOWERS. WINDS WILL INCREASE SIGNIFICANTLY BEHIND THE FRONT
WITH GUSTS TO 35-40 KTS LIKELY FROM ALMOST DUE NORTH. SNOW WILL
END BY 00Z-01Z WITH WINDS DECREASING SIGNIFICANTLY BY THEN AS
WELL. FRONT RANGE AIRPORTS MOST LIKELY TO SEE 1-2 INCH SNOW
TOTALS...WITH POTENTIAL FOR A LITTLE MORE THAN THAT AT KAPA IF
CONVECTION BECOMES MORE WIDESPREAD. VFR CONDITIONS AND LIGHTER
WINDS OVERNIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
BLOWING DUST ADVISORY UNTIL 7 PM MDT THIS EVENING FOR COZ046-047.
&&
$$
SHORT TERM...D-L
LONG TERM....DANKERS
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1102 AM EDT TUE MAR 11 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD ACROSS THE AREA TODAY.
STRONG LOW PRESSURE WILL THEN MOVE THROUGH WEDNESDAY INTO
WEDNESDAY NIGHT...FOLLOWED BY BUILDING HIGH PRESSURE THURSDAY
THROUGH FRIDAY. A COLD FRONT WILL PASS THROUGH ON SATURDAY...
WITH HIGH PRESSURE BUILDING IN BRIEFLY ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO MAJOR CHANGES FOR THIS UPDATE. MORNING 72501 SOUNDING AND
TRENDS SUGGEST A DAY OF CHASING TEMPERATURES UP. LATEST LAMP MOS
GUIDANCE IS BEHIND THE TEMPERATURE CURVE.
A PASSING WEAK COLD FRONT...DOWNSLOPE WNW FLOW ALONG WITH PARTIAL
SUNSHINE SHOULD HELP BOOST TEMPS TO 55-60 ACROSS NYC METRO AND
MOST OF LONG ISLAND...AND 50-55 TO THE NORTH...SEVERAL DEGREES
WARMER THAN A 00Z GFS/NAM MOS GUIDANCE BLEND. THE 06Z RAP SUGGESTS
THAT TEMPS COULD EVEN REACH THE LOWER 60S INVOF NYC WITH ENOUGH
AFTERNOON SUNSHINE...BUT HAVE DOUBTS AS TO WHETHER IT WILL GET
THIS WARM AS MID LEVEL CLOUDS WILL BE INCREASING LATE THIS
AFTERNOON AHEAD OF THE APPROACHING STORM.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
CLOUDS WILL LOWER/THICKEN TONIGHT ESPECIALLY NORTH/WEST OF NYC...
AHEAD OF LOW PRESSURE DEVELOPING IN THE OH VALLEY. OVERRUNNING
LIGHT PCPN SHOULD ALSO MOVE INTO AREAS MAINLY NORTH/WEST OF NYC
AFTER MIDNIGHT. HAVE TRENDED WARMER TONIGHT...WITH LOWS 40-45
INVOF NYC AND 35-40 ELSEWHERE...AND WITH ELEVATED WARM NOSE
MOVING IN PCPN SHOULD START OFF AS RAIN THROUGHOUT.
GFS/ECMWF RELATIVELY CLOSE ON DETAILS WED INTO WED NIGHT AS THE
INTENSIFYING LOW MOVES OUT OF THE OHIO VALLEY AND PASSES NW OF NYC
BY WED EVENING. THE BULK OF THE RAIN ON WED SHOULD BE NORTH OF THE
LOW TRACK DURING THE DAYTIME IN THE COOL SECTOR. AS THE SUB-980 MB
SFC LOW TRACKS OVER THE AREA JUST NW OF NYC AND THE COAST LATE WED
AFTERNOON/EVENING...MOST IF NOT ALL THE CWA COULD GET INTO THE
WARM SECTOR...WITH TEMPS RISING INTO THE 50S MAINLY ACROSS NYC
METRO...NE NJ AND THE LOWER HUDSON VALLEY WHERE MARINE INFLUENCE
WILL BE MINIMAL. A LINE OF FORCED LOW TOPPED CONVECTION IS LIKELY
ALONG A TRAILING COLD FRONT...WHICH COULD PRODUCE STRONG WIND
GUSTS ESPECIALLY ACROSS NE NJ AND NYC METRO WHERE SFC INSTABILITY
LIKELY TO BE SFC-BASED AS BOTH TEMPS/DEWPOINTS RISE INTO THE 50S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MUCH COLDER AIR WILL MOVE IN BEHIND THE INTENSE LOW WED NIGHT AS
IT DEPARTS TO THE GULF OF MAINE...WITH LOWS 20-25 AND POSSIBLY
FALLING TO THE UPPER TEENS WELL INLAND. GIVEN THE MORE NORTHERLY
LOW TRACK...HEAVIER PCPN SHOULD ALSO REMAIN TO THE NORTH...SO
LITTLE IF ANY ACCUMULATION EXPECTED LATE WED NIGHT AS PCPN
CHANGES OVER TO LIGHT SNOW OR SCT SNOW SHOWERS.
THU AND THU NIGHT WILL BE BLUSTERY AND VERY COLD...WITH TEMPS NOT
RISING MUCH IF AT ALL...REACHING THE MID AND UPPER 20S AT
BEST. NW WINDS COULD REACH ADVY CRITERIA ESPECIALLY ACROSS NYC
METRO AND LONG ISLAND. LOWS THEN EXPECTED TO FALL TO THE SINGLE
DIGITS INLAND...TEENS MOST ELSEWHERE...AND LOWER 20S IN NYC.
SEE CLIMATE SECTION FOR DETAILS ON RECORD COLD.
THIS VERY COLD AIR MASS WILL BE SHORT LIVED...AS DEEP LAYER
RIDGING BUILDS ACROSS WITH SW RETURN FLOW AND WAA ON FRI.
LOW PRESSURE MOVING THROUGH SOUTHERN CANADA LATE FRI INTO SAT WILL
DRAG A TRAILING COLD FRONT THROUGH BY MIDDAY SAT. SOME QUESTION
ON THE EXTENT OF PCPN WITH THIS SYSTEM AS VERY DRY AIR INITIALLY IN
PLACE WILL BE HARD TO OVERCOME. BETTER FORCING ALSO LOOKS TO BE TO
THE NORTH...SO HAVE ONLY MENTIONED SLIGHT CHANCE POP.
SUNDAY SHOULD BE DRY.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
BEHIND A DEPARTING LOW WELL TO THE NORTH...WEAK HIGH PRESSURE
BUILDS IN THROUGH THE DAY. MAINLY VFR WITH EXCEPTION OF MVFR HAZE
AT KGON. UNCERTAIN OF WHEN MVFR HAZE DISSIPATE...THINKING THIS
WILL BE THIS AFTERNOON. THERE IS SOME CONCERN FOR MVFR CIGS
DEVELOPING AFTER 06Z FOR THE 30H TAFS AHEAD OF AN APPROACHING WARM
FRONT. CONFIDENCE IS LOW AT THIS TIME. MVFR/IFR CIGS LIKELY TO
DEVELOP IN THE 12Z TO 18Z TIME FRAME ALONG WITH SOME LIGHT RAIN.
WINDS INITIALLY W-WNW...MOSTLY LEFT OF 310 MAGNETIC. WINDS
AROUND 7-12 KTS DECREASE IN SPEED LATER THIS AFTERNOON WHILE
BECOMING MORE W-SW. THIS CONTINUES INTO THE EVENING WITH POSSIBLE
WIDE VARIATIONS IN DIRECTION AS RIDGE AXIS BUILDS IN. A FAST
MOVING STORM SYSTEM APPROACHES FROM THE OHIO VALLEY WED
MORNING...SENDING A WARM FRONT TOWARD THE AREA BY DAYBREAK WED.
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: POSSIBLE GUSTS UP TO 17 KT FROM MID MORNING
THROUGH EARLY AFTERNOON. WINDS COULD BE 30-40 DEGREES LEFT OF
FORECAST WIND DIRECTION AT TIMES.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: POSSIBLE GUST TO AROUND 17 KT FROM MID
MORNING THROUGH EARLY THIS AFTERNOON. WINDS COULD BE 30-40 DEGREES
LEFT OF FORECAST WIND DIRECTION AT TIMES. POSSIBLE HYBRID SEA
BREEZE WITH WINDS BACKING AROUND TO 220-250 THIS AFTERNOON.
KLGA FCSTER COMMENTS: POSSIBLE GUST TO AROUND 17 KT FROM MID
MORNING THROUGH EARLY THIS AFTERNOON. WINDS COULD BE 30-40 DEGREES
LEFT OF FORECAST WIND DIRECTION AT TIMES.
KTEB FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID
MORNING THROUGH EARLY THIS AFTERNOON. WINDS COULD BE 30-40 DEGREES
LEFT OF FORECAST WIND DIRECTION AT TIMES.
KHPN FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID
MORNING THROUGH EARLY THIS AFTERNOON. WINDS COULD BE 30-40 DEGREES
LEFT OF FORECAST WIND DIRECTION AT TIMES.
KISP FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID
MORNING THROUGH EARLY THIS AFTERNOON. WINDS COULD BE 30-40 DEGREES
LEFT OF FORECAST WIND DIRECTION AT TIMES. POSSIBLE HYBRID SEA
BREEZE WITH WINDS BACKING AROUND TO 220-250 THIS AFTERNOON.
.OUTLOOK FOR 12Z WED THROUGH SAT...
.WED-WED NIGHT...SUB-VFR IN RA. ESE-SE WINDS AROUND 10 KT GUSTING
UP TO AROUND 20 KT LATE WED AFTN-EVE THEN W-NW WINDS AROUND 20 KT
GUSTING UP TO 35 KT LATER WED NIGHT.
.THU...IMPROVING TO VFR EARLY. NW G30-40KT.
.FRI...VFR.
.SAT...SUB-VFR POSSIBLE IN SHOWERS.
&&
.MARINE...
SCA HAS BEEN CANCELLED FOR THE OCEAN E OF MORICHES INLET.
WINDS AND SEAS INCREASE ON WED WITH SOUTHERLY FLOW. SCA CRITERIA
ARE LIKELY TO BE REACHED DURING THE SECOND HALF OF THE DAY.
WINDS AND SEAS CONTINUE TO INCREASE INTO WEDNESDAY NIGHT...WITH
GALES EXPECTED TO DEVELOP. THEREFORE...WENT AHEAD AND ISSUED A WATCH
CONSIDERING THE HIGH AMOUNT OF CONFIDENCE IN THE STRENGTHENING WINDS
WITH THE DEEPENING LOW PRESSURE MOVING OFF TO THE EAST. GALES THEN
LOOK TO END THURSDAY NIGHT...BUT WINDS AND SEAS STILL REMAIN
ELEVATED...WITH 5 FT SEAS NOT DIMINISHING ACROSS THE EASTERN
OCEAN WATERS UNTIL AT LEAST FRIDAY MORNING.
SCA CONDITIONS POSSIBLY RETURN LATE FRIDAY NIGHT INTO SATURDAY WITH
ANOTHER APPROACHING SYSTEM OVER THE WEEKEND.
&&
.HYDROLOGY...
LOW TRACK AND THEREFORE ASSOCIATED QPF WITH THE MID WEEK STORM
HAVE TRENDED NORTHWARD...SO ONLY EXPECT BASIN AVG QPF OF 1/2 TO 1
INCH FOR SOUTHERN CT...THE LOWER HUDSON VALLEY AND INTERIOR NE
NJ. LOWER QPF OF 1/4 TO 1/2 INCH EXPECTED FOR NYC METRO AND LONG
ISLAND. LOCAL AMTS OF ABOUT 1/2 INCH HIGHER ARE POSSIBLE
IN TSTMS. THE BULK OF THIS PCPN SHOULD BE RAIN.
&&
.CLIMATE...
RECORD LOW TEMPS ARE LIKELY TO BE TIED OR BROKEN AT MOST LOCAL
CLIMATE SITES FRIDAY MORNING.
RECORD AND FORECAST LOW TEMPS FOR FRIDAY MORNING (MAR 14)...
RECORD LOW
MINIMUM FCST
NEWARK.........17 IN 1980 17
BRIDGEPORT.....16 IN 1980 13
CENTRAL PARK... 8 IN 1896 19
LAGUARDIA......18 IN 1980 22
KENNEDY........19 IN 1980 18
ISLIP..........17 IN 1989 13
&&
.EQUIPMENT...
THE NOAA WEATHER RADIO TRANSMITTER THAT SERVES THE NEW YORK CITY
METROPOLITAN AREA REMAINS OUT OF SERVICE DUE TO RADIO FREQUENCY
INTERFERENCE WITH THE U.S COAST GUARD TRANSMITTER.
FOR MORE INFORMATION SEE THE FOLLOWING PUBLIC INFORMATION
STATEMENT (ALL LOWER CASE):
WWW.ERH.NOAA.GOV/OKX/PRODUCTS/STATIC.TXT
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR
ANZ330-335-338-340-345-350-353-355.
&&
$$
SYNOPSIS...GOODMAN/SEARS
NEAR TERM...PICCA/TONGUE
SHORT TERM...GOODMAN/PICCA
LONG TERM...GOODMAN/PICCA/SEARS
AVIATION...JM/DW
MARINE...PICCA/TONGUE
HYDROLOGY...GOODMAN
CLIMATE...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1000 AM EDT TUE MAR 11 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD ACROSS THE AREA TODAY.
STRONG LOW PRESSURE WILL THEN MOVE THROUGH WEDNESDAY INTO
WEDNESDAY NIGHT...FOLLOWED BY BUILDING HIGH PRESSURE THURSDAY
THROUGH FRIDAY. A COLD FRONT WILL PASS THROUGH ON SATURDAY...
WITH HIGH PRESSURE BUILDING IN BRIEFLY ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO MAJOR CHANGES FOR THIS UPDATE. MORNING 72501 SOUNDING AND
TRENDS SUGGEST A DAY OF CHASING TEMPERATURES UP. LATEST LAMP MOS
GUIDANCE IS BEHIND THE TEMPERATURE CURVE.
A PASSING WEAK COLD FRONT...DOWNSLOPE WNW FLOW ALONG WITH PARTIAL
SUNSHINE SHOULD HELP BOOST TEMPS TO 55-60 ACROSS NYC METRO AND
MOST OF LONG ISLAND...AND 50-55 TO THE NORTH...SEVERAL DEGREES
WARMER THAN A 00Z GFS/NAM MOS GUIDANCE BLEND. THE 06Z RAP SUGGESTS
THAT TEMPS COULD EVEN REACH THE LOWER 60S INVOF NYC WITH ENOUGH
AFTERNOON SUNSHINE...BUT HAVE DOUBTS AS TO WHETHER IT WILL GET
THIS WARM AS MID LEVEL CLOUDS WILL BE INCREASING LATE THIS
AFTERNOON AHEAD OF THE APPROACHING STORM.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
CLOUDS WILL LOWER/THICKEN TONIGHT ESPECIALLY NORTH/WEST OF NYC...
AHEAD OF LOW PRESSURE DEVELOPING IN THE OH VALLEY. OVERRUNNING
LIGHT PCPN SHOULD ALSO MOVE INTO AREAS MAINLY NORTH/WEST OF NYC
AFTER MIDNIGHT. HAVE TRENDED WARMER TONIGHT...WITH LOWS 40-45
INVOF NYC AND 35-40 ELSEWHERE...AND WITH ELEVATED WARM NOSE
MOVING IN PCPN SHOULD START OFF AS RAIN THROUGHOUT.
GFS/ECMWF RELATIVELY CLOSE ON DETAILS WED INTO WED NIGHT AS THE
INTENSIFYING LOW MOVES OUT OF THE OHIO VALLEY AND PASSES NW OF NYC
BY WED EVENING. THE BULK OF THE RAIN ON WED SHOULD BE NORTH OF THE
LOW TRACK DURING THE DAYTIME IN THE COOL SECTOR. AS THE SUB-980 MB
SFC LOW TRACKS OVER THE AREA JUST NW OF NYC AND THE COAST LATE WED
AFTERNOON/EVENING...MOST IF NOT ALL THE CWA COULD GET INTO THE
WARM SECTOR...WITH TEMPS RISING INTO THE 50S MAINLY ACROSS NYC
METRO...NE NJ AND THE LOWER HUDSON VALLEY WHERE MARINE INFLUENCE
WILL BE MINIMAL. A LINE OF FORCED LOW TOPPED CONVECTION IS LIKELY
ALONG A TRAILING COLD FRONT...WHICH COULD PRODUCE STRONG WIND
GUSTS ESPECIALLY ACROSS NE NJ AND NYC METRO WHERE SFC INSTABILITY
LIKELY TO BE SFC-BASED AS BOTH TEMPS/DEWPOINTS RISE INTO THE 50S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MUCH COLDER AIR WILL MOVE IN BEHIND THE INTENSE LOW WED NIGHT AS
IT DEPARTS TO THE GULF OF MAINE...WITH LOWS 20-25 AND POSSIBLY
FALLING TO THE UPPER TEENS WELL INLAND. GIVEN THE MORE NORTHERLY
LOW TRACK...HEAVIER PCPN SHOULD ALSO REMAIN TO THE NORTH...SO
LITTLE IF ANY ACCUMULATION EXPECTED LATE WED NIGHT AS PCPN
CHANGES OVER TO LIGHT SNOW OR SCT SNOW SHOWERS.
THU AND THU NIGHT WILL BE BLUSTERY AND VERY COLD...WITH TEMPS NOT
RISING MUCH IF AT ALL...REACHING THE MID AND UPPER 20S AT
BEST. NW WINDS COULD REACH ADVY CRITERIA ESPECIALLY ACROSS NYC
METRO AND LONG ISLAND. LOWS THEN EXPECTED TO FALL TO THE SINGLE
DIGITS INLAND...TEENS MOST ELSEWHERE...AND LOWER 20S IN NYC.
SEE CLIMATE SECTION FOR DETAILS ON RECORD COLD.
THIS VERY COLD AIR MASS WILL BE SHORT LIVED...AS DEEP LAYER
RIDGING BUILDS ACROSS WITH SW RETURN FLOW AND WAA ON FRI.
LOW PRESSURE MOVING THROUGH SOUTHERN CANADA LATE FRI INTO SAT WILL
DRAG A TRAILING COLD FRONT THROUGH BY MIDDAY SAT. SOME QUESTION
ON THE EXTENT OF PCPN WITH THIS SYSTEM AS VERY DRY AIR INITIALLY IN
PLACE WILL BE HARD TO OVERCOME. BETTER FORCING ALSO LOOKS TO BE TO
THE NORTH...SO HAVE ONLY MENTIONED SLIGHT CHANCE POP.
SUNDAY SHOULD BE DRY.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
FLOW WILL BE RIGHT AROUND 310 FROM MID MORNING TO MID AFTERNOON
AT 7 TO 10 KT...BEFORE BACKING A BIT BY LATE AFT TO 270-290. RIDGE
AXIS BUILDS INTO THE AREA THIS EVE WITH A LIGHT AND VARIABLE FLOW.
A FAST MOVING STORM SYSTEM APPROACHES FROM THE OHIO VALLEY WED
MORNING...SENDING A WARM FRONT TOWARD THE AREA BY DAYBREAK.
VFR CONDITIONS ARE FORECAST THROUGH THE NEXT 24H. THERE IS SOME
CONCERN FOR MVFR CIGS DEVELOPING AFTER 06Z FOR THE 30H TAFS AHEAD
OF AN APPROACHING WARM FRONT. CONFIDENCE IS LOW AT THIS TIME.
MVFR/IFR CIGS LIKELY TO DEVELOP IN THE 12Z TO 18Z TIME FRAME
ALONG WITH SOME LIGHT RAIN.
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: POSSIBLE GUSTS UP TO 17 KT FROM MID MORNING
THROUGH EARLY AFTERNOON.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: POSSIBLE GUST TO AROUND 17 KT FROM MID
MORNING THROUGH EARLY THIS AFTERNOON. POSSIBLE HYBRID SEA BREEZE
WITH WINDS BACKING AROUND TO 230-250 LATE THIS AFTERNOON.
KLGA FCSTER COMMENTS: POSSIBLE GUST TO AROUND 17 KT FROM MID
MORNING THROUGH EARLY THIS AFTERNOON.
KTEB FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID
MORNING THROUGH EARLY THIS AFTERNOON.
KHPN FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID
MORNING THROUGH EARLY THIS AFTERNOON.
KISP FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID
MORNING THROUGH EARLY THIS AFTERNOON.
.OUTLOOK FOR 12Z WED THROUGH SAT...
.WED-WED NIGHT...SUB-VFR IN RA. ESE-SE WINDS AROUND 10 KT GUSTING
UP TO AROUND 20 KT LATE WED AFTN-EVE THEN W-NW WINDS AROUND 20 KT
GUSTING UP TO 35 KT LATER WED NIGHT.
.THU...IMPROVING TO VFR EARLY. NW G30-40KT.
.FRI...VFR.
.SAT...SUB-VFR POSSIBLE IN SHOWERS.
&&
.MARINE...
SCA HAS BEEN CANCELLED FOR THE OCEAN E OF MORICHES INLET.
WINDS AND SEAS INCREASE ON WED WITH SOUTHERLY FLOW. SCA CRITERIA
ARE LIKELY TO BE REACHED DURING THE SECOND HALF OF THE DAY.
WINDS AND SEAS CONTINUE TO INCREASE INTO WEDNESDAY NIGHT...WITH
GALES EXPECTED TO DEVELOP. THEREFORE...WENT AHEAD AND ISSUED A WATCH
CONSIDERING THE HIGH AMOUNT OF CONFIDENCE IN THE STRENGTHENING WINDS
WITH THE DEEPENING LOW PRESSURE MOVING OFF TO THE EAST. GALES THEN
LOOK TO END THURSDAY NIGHT...BUT WINDS AND SEAS STILL REMAIN
ELEVATED...WITH 5 FT SEAS NOT DIMINISHING ACROSS THE EASTERN
OCEAN WATERS UNTIL AT LEAST FRIDAY MORNING.
SCA CONDITIONS POSSIBLY RETURN LATE FRIDAY NIGHT INTO SATURDAY WITH
ANOTHER APPROACHING SYSTEM OVER THE WEEKEND.
&&
.HYDROLOGY...
LOW TRACK AND THEREFORE ASSOCIATED QPF WITH THE MID WEEK STORM
HAVE TRENDED NORTHWARD...SO ONLY EXPECT BASIN AVG QPF OF 1/2 TO 1
INCH FOR SOUTHERN CT...THE LOWER HUDSON VALLEY AND INTERIOR NE
NJ. LOWER QPF OF 1/4 TO 1/2 INCH EXPECTED FOR NYC METRO AND LONG
ISLAND. LOCAL AMTS OF ABOUT 1/2 INCH HIGHER ARE POSSIBLE
IN TSTMS. THE BULK OF THIS PCPN SHOULD BE RAIN.
&&
.CLIMATE...
RECORD LOW TEMPS ARE LIKELY TO BE TIED OR BROKEN AT MOST LOCAL
CLIMATE SITES FRIDAY MORNING.
RECORD AND FORECAST LOW TEMPS FOR FRIDAY MORNING (MAR 14)...
RECORD LOW
MINIMUM FCST
NEWARK.........17 IN 1980 17
BRIDGEPORT.....16 IN 1980 13
CENTRAL PARK... 8 IN 1896 19
LAGUARDIA......18 IN 1980 22
KENNEDY........19 IN 1980 18
ISLIP..........17 IN 1989 13
&&
.EQUIPMENT...
THE NOAA WEATHER RADIO TRANSMITTER THAT SERVES THE NEW YORK CITY
METROPOLITAN AREA REMAINS OUT OF SERVICE DUE TO RADIO FREQUENCY
INTERFERENCE WITH THE U.S COAST GUARD TRANSMITTER.
FOR MORE INFORMATION SEE THE FOLLOWING PUBLIC INFORMATION
STATEMENT (ALL LOWER CASE):
WWW.ERH.NOAA.GOV/OKX/PRODUCTS/STATIC.TXT
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR
ANZ330-335-338-340-345-350-353-355.
&&
$$
SYNOPSIS...GOODMAN/SEARS
NEAR TERM...PICCA/TONGUE
SHORT TERM...GOODMAN/PICCA
LONG TERM...GOODMAN/PICCA/SEARS
AVIATION...DW
MARINE...PICCA/TONGUE
HYDROLOGY...GOODMAN
CLIMATE...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
751 AM EDT TUE MAR 11 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD ACROSS THE AREA TODAY.
STRONG LOW PRESSURE WILL THEN MOVE THROUGH WEDNESDAY INTO
WEDNESDAY NIGHT...FOLLOWED BY BUILDING HIGH PRESSURE THURSDAY
THROUGH FRIDAY. A COLD FRONT WILL PASS THROUGH ON SATURDAY...
WITH HIGH PRESSURE BUILDING IN BRIEFLY ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO MAJOR CHANGES FOR THIS UPDATE. BUMPED HOURLY TEMPS/MAX T UP A
FEW DEGREES THOUGH TO ACCOUNT FOR OBSERVATIONAL AND HI-RES
GUIDANCE TRENDS SHOWING BETTER WARMING TODAY.
BEHIND A PASSING WEAK COLD FRONT...DOWNSLOPE WNW FLOW ALONG WITH
PARTIAL SUNSHINE SHOULD HELP BOOST TEMPS TO 55-60 ACROSS NYC METRO
AND MOST OF LONG ISLAND...AND 50-55 TO THE NORTH...SEVERAL DEGREES
WARMER THAN A 00Z GFS/NAM MOS GUIDANCE BLEND. THE 06Z RAP SUGGESTS
THAT TEMPS COULD EVEN REACH THE LOWER 60S INVOF NYC WITH ENOUGH
AFTERNOON SUNSHINE...BUT HAVE DOUBTS AS TO WHETHER IT WILL GET
THIS WARM AS MID LEVEL CLOUDS WILL BE INCREASING LATE THIS
AFTERNOON AHEAD OF THE APPROACHING STORM.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
CLOUDS WILL LOWER/THICKEN TONIGHT ESPECIALLY NORTH/WEST OF NYC...
AHEAD OF LOW PRESSURE DEVELOPING IN THE OH VALLEY. OVERRUNNING
LIGHT PRECIP SHOULD ALSO MOVE INTO AREAS MAINLY NORTH/WEST OF NYC
AFTER MIDNIGHT. HAVE TRENDED WARMER TONIGHT...WITH LOWS 40-45
INVOF NYC AND 35-40 ELSEWHERE...AND WITH ELEVATED WARM NOSE
MOVING IN PRECIP SHOULD START OFF AS RAIN THROUGHOUT.
GFS/ECMWF RELATIVELY CLOSE ON DETAILS WED INTO WED NIGHT AS THE
INTENSIFYING LOW MOVES OUT OF THE OHIO VALLEY AND PASSES NW OF NYC
BY WED EVENING. THE BULK OF THE RAIN ON WED SHOULD BE NORTH OF THE
LOW TRACK DURING THE DAYTIME IN THE COOL SECTOR. AS THE SUB-980 MB
SFC LOW TRACKS OVER THE AREA JUST NW OF NYC AND THE COAST LATE WED
AFTERNOON/EVENING...MOST IF NOT ALL THE CWA COULD GET INTO THE
WARM SECTOR...WITH TEMPS RISING INTO THE 50S MAINLY ACROSS NYC
METRO...NE NJ AND THE LOWER HUDSON VALLEY WHERE MARINE INFLUENCE
WILL BE MINIMAL. A LINE OF FORCED LOW TOPPED CONVECTION IS LIKELY
ALONG A TRAILING COLD FRONT...WHICH COULD PRODUCE STRONG WIND
GUSTS ESPECIALLY ACROSS NE NJ AND NYC METRO WHERE SFC INSTABILITY
LIKELY TO BE SFC-BASED AS BOTH TEMPS/DEWPOINTS RISE INTO THE 50S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MUCH COLDER AIR WILL MOVE IN BEHIND THE INTENSE LOW WED NIGHT AS
IT DEPARTS TO THE GULF OF MAINE...WITH LOWS 20-25 AND POSSIBLY
FALLING TO THE UPPER TEENS WELL INLAND. GIVEN THE MORE NORTHERLY
LOW TRACK...HEAVIER PRECIP SHOULD ALSO REMAIN TO THE NORTH...SO
LITTLE IF ANY ACCUMULATION EXPECTED LATE WED NIGHT AS PRECIP
CHANGES OVER TO LIGHT SNOW OR SCT SNOW SHOWERS.
THU AND THU NIGHT WILL BE BLUSTERY AND VERY COLD...WITH TEMPS NOT
RISING MUCH IF AT ALL...REACHING THE MID AND UPPER 20S AT
BEST. NW WINDS COULD REACH ADVY CRITERIA ESPECIALLY ACROSS NYC
METRO AND LONG ISLAND. LOWS THEN EXPECTED TO FALL TO THE SINGLE
DIGITS INLAND...TEENS MOST ELSEWHERE...AND LOWER 20S IN NYC.
SEE CLIMATE SECTION FOR DETAILS ON RECORD COLD.
THIS VERY COLD AIR MASS WILL BE SHORT LIVED...AS DEEP LAYER
RIDGING BUILDS ACROSS WITH SW RETURN FLOW AND WAA ON FRI.
LOW PRESSURE MOVING THROUGH SOUTHERN CANADA LATE FRI INTO SAT WILL
DRAG A TRAILING COLD FRONT THROUGH BY MIDDAY SAT. SOME QUESTION
ON THE EXTENT OF PCPN WITH THIS SYSTEM AS VERY DRY AIR INITIALLY IN
PLACE WILL BE HARD TO OVERCOME. BETTER FORCING ALSO LOOKS TO BE TO
THE NORTH...SO HAVE ONLY MENTIONED SLIGHT CHANCE POP.
SUNDAY SHOULD BE DRY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
FLOW WILL BE RIGHT AROUND 310 FROM MID MORNING TO MID AFTERNOON
AT 7 TO 10 KT...BEFORE BACKING A BIT BY LATE AFT TO 270-290. RIDGE
AXIS BUILDS INTO THE AREA THIS EVE WITH A LIGHT AND VARIABLE FLOW.
A FAST MOVING STORM SYSTEM APPROACHES FROM THE OHIO VALLEY WED
MORNING...SENDING A WARM FRONT TOWARD THE AREA BY DAYBREAK.
VFR CONDITIONS ARE FORECAST THROUGH THE NEXT 24H. THERE IS SOME
CONCERN FOR MVFR CIGS DEVELOPING AFTER 06Z FOR THE 30H TAFS AHEAD
OF AN APPROACHING WARM FRONT. CONFIDENCE IS LOW AT THIS TIME.
MVFR/IFR CIGS LIKELY TO DEVELOP IN THE 12Z TO 18Z TIME FRAME
ALONG WITH SOME LIGHT RAIN.
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: POSSIBLE GUSTS UP TO 17 KT FROM MID MORNING
THROUGH EARLY AFTERNOON.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: POSSIBLE GUST TO AROUND 17 KT FROM MID
MORNING THROUGH EARLY THIS AFTERNOON. POSSIBLE HYRID SEABREEZE
WITH WINDS BACKING AROUND TO 230-250 LATE THIS AFTERNOON.
KLGA FCSTER COMMENTS: POSSIBLE GUST TO AROUND 17 KT FROM MID
MORNING THROUGH EARLY THIS AFTERNOON.
KTEB FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID
MORNING THROUGH EARLY THIS AFTERNOON.
KHPN FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID
MORNING THROUGH EARLY THIS AFTERNOON.
KISP FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID
MORNING THROUGH EARLY THIS AFTERNOON.
.OUTLOOK FOR 12Z WED THROUGH SAT...
.WED-WED NIGHT...SUB-VFR IN RA. ESE-SE WINDS AROUND 10 KT GUSTING
UP TO AROUND 20 KT LATE WED AFTN-EVE THEN W-NW WINDS AROUND 20 KT
GUSTING UP TO 35 KT LATER WED NIGHT.
.THU...IMPROVING TO VFR EARLY. NW G30-40KT.
.FRI...VFR.
.SAT...SUB-VFR POSSIBLE IN SHOWERS.
&&
.MARINE...
WINDS STARTING TO BACK SW AND GUST OVER 20 KT AT 44017. SHOULD SEE
MINIMAL SCA CONDS FROM THERE ON EAST THIS MORNING...SO SCA
REMAINS IN EFFECT ONLY ON THE OCEAN E OF MORICHES INLET.
WINDS AND SEAS INCREASE ON WED WITH SOUTHERLY FLOW. SCA CRITERIA
ARE LIKELY TO BE REACHED DURING THE SECOND HALF OF THE DAY.
WINDS AND SEAS CONTINUE TO INCREASE INTO WEDNESDAY NIGHT...WITH
GALES EXPECTED TO DEVELOP. THEREFORE...WENT AHEAD AND ISSUED A WATCH
CONSIDERING THE HIGH AMOUNT OF CONFIDENCE IN THE STRENGTHENING WINDS
WITH THE DEEPENING LOW PRESSURE MOVING OFF TO THE EAST. GALES THEN
LOOK TO END THURSDAY NIGHT...BUT WINDS AND SEAS STILL REMAIN
ELEVATED...WITH 5 FT SEAS NOT DIMINISHING ACROSS THE EASTERN
OCEAN WATERS UNTIL AT LEAST FRIDAY MORNING.
SCA CONDITIONS POSSIBLY RETURN LATE FRIDAY NIGHT INTO SATURDAY WITH
ANOTHER APPROACHING SYSTEM OVER THE WEEKEND.
&&
.HYDROLOGY...
LOW TRACK AND THEREFORE ASSOCIATED QPF WITH THE MID WEEK STORM
HAVE TRENDED NORTHWARD...SO ONLY EXPECT BASIN AVG QPF OF 1/2 TO 1
INCH FOR SOUTHERN CT...THE LOWER HUDSON VALLEY AND INTERIOR NE
NJ. LOWER QPF OF 1/4 TO 1/2 INCH EXPECTED FOR NYC METRO AND LONG
ISLAND. LOCAL AMTS OF ABOUT 1/2 INCH HIGHER ARE POSSIBLE
IN TSTMS. THE BULK OF THIS PRECIP SHOULD BE RAIN.
&&
.CLIMATE...
RECORD LOW TEMPS ARE LIKELY TO BE TIED OR BROKEN AT MOST LOCAL
CLIMATE SITES FRIDAY MORNING.
RECORD AND FORECAST LOW TEMPS FOR FRIDAY MORNING (MAR 14)...
RECORD LOW
MINIMUM FCST
NEWARK.........17 IN 1980 17
BRIDGEPORT.....16 IN 1980 13
CENTRAL PARK... 8 IN 1896 19
LAGUARDIA......18 IN 1980 22
KENNEDY........19 IN 1980 18
ISLIP..........17 IN 1989 13
&&
.EQUIPMENT...
THE NOAA WEATHER RADIO TRANSMITTER THAT SERVES THE NEW YORK CITY
METROPOLITAN AREA REMAINS OUT OF SERVICE DUE TO RADIO FREQUENCY
INTERFERENCE WITH THE U.S COAST GUARD TRANSMITTER.
FOR MORE INFORMATION SEE THE FOLLOWING PUBLIC INFORMATION
STATEMENT (ALL LOWER CASE):
WWW.ERH.NOAA.GOV/OKX/PRODUCTS/STATIC.TXT
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR
ANZ330-335-338-340-345-350-353-355.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR ANZ350.
&&
$$
SYNOPSIS...GOODMAN/SEARS
NEAR TERM...GOODMAN/PICCA
SHORT TERM...GOODMAN/PICCA
LONG TERM...GOODMAN/PICCA/SEARS
AVIATION...DW
MARINE...GOODMAN/PICCA/SEARS
HYDROLOGY...GOODMAN
CLIMATE...PICCA
EQUIPMENT...//
AREA FORECAST DISCUSSION
NWS NEW YORK NY
506 AM EDT TUE MAR 11 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD ACROSS THE AREA TODAY.
STRONG LOW PRESSURE WILL THEN MOVE THROUGH WEDNESDAY INTO
WEDNESDAY NIGHT...FOLLOWED BY BUILDING HIGH PRESSURE THURSDAY
THROUGH FRIDAY. A COLD FRONT WILL PASS THROUGH ON SATURDAY...
WITH HIGH PRESSURE BUILDING IN BRIEFLY ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK COLD FRONT WAS JUST WEST OF THE AREA AS OF 08Z. THE FRONT
SHOULD MOVE THROUGH BY DAYBREAK...FOLLOWED BY DOWNSLOPE WNW FLOW
THAT ALONG WITH PARTIAL SUNSHINE SHOULD HELP BOOST TEMPS TO 55-60
ACROSS NYC METRO AND MOST OF LONG ISLAND...AND 50-55 TO THE
NORTH...SEVERAL DEGREES WARMER THAN A 00Z GFS/NAM MOS GUIDANCE
BLEND. THE 06Z RAP SUGGESTS THAT TEMPS COULD EVEN REACH THE LOWER
60S INVOF NYC WITH ENOUGH AFTERNOON SUNSHINE...BUT HAVE DOUBTS AS
TO WHETHER IT WILL GET THIS WARM AS MID LEVEL CLOUDS WILL BE
INCREASING LATE THIS AFTERNOON AHEAD OF THE APPROACHING STORM.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
CLOUDS WILL LOWER/THICKEN TONIGHT ESPECIALLY NORTH/WEST OF NYC...
AHEAD OF LOW PRESSURE DEVELOPING IN THE OH VALLEY. OVERRUNNING
LIGHT PRECIP SHOULD ALSO MOVE INTO AREAS MAINLY NORTH/WEST OF NYC
AFTER MIDNIGHT. HAVE TRENDED WARMER TONIGHT...WITH LOWS 40-45
INVOF NYC AND 35-40 ELSEWHERE...AND WITH ELEVATED WARM NOSE
MOVING IN PRECIP SHOULD START OFF AS RAIN THROUGHOUT.
GFS/ECMWF RELATIVELY CLOSE ON DETAILS WED INTO WED NIGHT AS THE
INTENSIFYING LOW MOVES OUT OF THE OHIO VALLEY AND PASSES NW OF NYC
BY WED EVENING. THE BULK OF THE RAIN ON WED SHOULD BE NORTH OF THE
LOW TRACK DURING THE DAYTIME IN THE COOL SECTOR. AS THE SUB-980 MB
SFC LOW TRACKS OVER THE AREA JUST NW OF NYC AND THE COAST LATE WED
AFTERNOON/EVENING...MOST IF NOT ALL THE CWA COULD GET INTO THE
WARM SECTOR...WITH TEMPS RISING INTO THE 50S MAINLY ACROSS NYC
METRO...NE NJ AND THE LOWER HUDSON VALLEY WHERE MARINE INFLUENCE
WILL BE MINIMAL. A LINE OF FORCED LOW TOPPED CONVECTION IS LIKELY
ALONG A TRAILING COLD FRONT...WHICH COULD PRODUCE STRONG WIND
GUSTS ESPECIALLY ACROSS NE NJ AND NYC METRO WHERE SFC INSTABILITY
LIKELY TO BE SFC-BASED AS BOTH TEMPS/DEWPOINTS RISE INTO THE 50S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MUCH COLDER AIR WILL MOVE IN BEHIND THE INTENSE LOW WED NIGHT AS
IT DEPARTS TO THE GULF OF MAINE...WITH LOWS 20-25 AND POSSIBLY
FALLING TO THE UPPER TEENS WELL INLAND. GIVEN THE MORE NORTHERLY
LOW TRACK...HEAVIER PRECIP SHOULD ALSO REMAIN TO THE NORTH...SO
LITTLE IF ANY ACCUMULATION EXPECTED LATE WED NIGHT AS PRECIP
CHANGES OVER TO LIGHT SNOW OR SCT SNOW SHOWERS.
THU AND THU NIGHT WILL BE BLUSTERY AND VERY COLD...WITH TEMPS NOT
RISING MUCH IF AT ALL...REACHING THE MID AND UPPER 20S AT
BEST. NW WINDS COULD REACH ADVY CRITERIA ESPECIALLY ACROSS NYC
METRO AND LONG ISLAND. LOWS THEN EXPECTED TO FALL TO THE SINGLE
DIGITS INLAND...TEENS MOST ELSEWHERE...AND LOWER 20S IN NYC.
SEE CLIMATE SECTION FOR DETAILS ON RECORD COLD.
THIS VERY COLD AIR MASS WILL BE SHORT LIVED...AS DEEP LAYER
RIDGING BUILDS ACROSS WITH SW RETURN FLOW AND WAA ON FRI.
LOW PRESSURE MOVING THROUGH SOUTHERN CANADA LATE FRI INTO SAT WILL
DRAG A TRAILING COLD FRONT THROUGH BY MIDDAY SAT. SOME QUESTION
ON THE EXTENT OF PCPN WITH THIS SYSTEM AS VERY DRY AIR INITIALLY IN
PLACE WILL BE HARD TO OVERCOME. BETTER FORCING ALSO LOOKS TO BE TO
THE NORTH...SO HAVE ONLY MENTIONED SLIGHT CHANCE POP.
SUNDAY SHOULD BE DRY.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
W-SW WINDS WILL VEER AROUND TO THE W-NW BEHIND A WEAK TROF/COLD
FRONT OVER THE NEXT COUPLE OF HOURS. FLOW WILL BE RIGHT AROUND 310
FROM MID MORNING TO MID AFTERNOON AT 7 TO 10 KT...BEFORE BACKING A
BIT BY LATE AFT TO THE W. RIDGE AXIS BUILDS INTO THE AREA THIS EVE
WITH A LIGHT AND VARIABLE FLOW.
VFR CONDITIONS ARE FORECAST THROUGH THE PERIOD. THERE IS SOME CONCERN
FOR MVFR CIGS DEVELOPING AFTER 06Z FOR THE 30H TAFS AHEAD OF AN
APPROACHING WARM FRONT. CONFIDENCE IS LOW AT THIS TIME.
...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: POSSIBLE GUSTS UP TO 17 KT FROM MID MORNING
THROUGH EARLY AFTERNOON.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: POSSIBLE GUST TO AROUND 17 KT FROM MID
MORNING THROUGH EARLY THIS AFTERNOON. POSSIBLE HYRID SEABREEZE
WITH WINDS BACKING AROUND TO 230-250 LATE THIS AFTERNOON.
KLGA FCSTER COMMENTS: POSSIBLE GUST TO AROUND 17 KT FROM MID
MORNING THROUGH EARLY THIS AFTERNOON.
KTEB FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID
MORNING THROUGH EARLY THIS AFTERNOON.
KHPN FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID
MORNING THROUGH EARLY THIS AFTERNOON.
KISP FCSTER COMMENTS: POSSIBLE GUST TO AROUND 15 KT FROM MID
MORNING THROUGH EARLY THIS AFTERNOON.
.OUTLOOK FOR 06Z WED THROUGH SAT...
.WED-WED NIGHT...SUB-VFR IN RA. ESE-SE WINDS AROUND 10 KT GUSTING
UP TO AROUND 20 KT LATE WED AFTN-EVE THEN W-NW WINDS AROUND 20 KT
GUSTING UP TO 35 KT LATER WED NIGHT.
.THU...IMPROVING TO VFR EARLY. NW G30-40KT.
.FRI...VFR.
.SAT...SUB-VFR POSSIBLE IN SHOWERS.
&&
.MARINE...
WINDS STARTING TO BACK SW AND GUST OVER 20 KT AT 44017. SHOULD SEE
MINIMAL SCA CONDS FROM THERE ON EAST THIS MORNING...SO SCA
REMAINS IN EFFECT ONLY ON THE OCEAN E OF MORICHES INLET.
WINDS AND SEAS INCREASE ON WED WITH SOUTHERLY FLOW. SCA CRITERIA
ARE LIKELY TO BE REACHED DURING THE SECOND HALF OF THE DAY.
WINDS AND SEAS CONTINUE TO INCREASE INTO WEDNESDAY NIGHT...WITH
GALES EXPECTED TO DEVELOP. THEREFORE...WENT AHEAD AND ISSUED A WATCH
CONSIDERING THE HIGH AMOUNT OF CONFIDENCE IN THE STRENGTHENING WINDS
WITH THE DEEPENING LOW PRESSURE MOVING OFF TO THE EAST. GALES THEN
LOOK TO END THURSDAY NIGHT...BUT WINDS AND SEAS STILL REMAIN
ELEVATED...WITH 5 FT SEAS NOT DIMINISHING ACROSS THE EASTERN
OCEAN WATERS UNTIL AT LEAST FRIDAY MORNING.
SCA CONDITIONS POSSIBLY RETURN LATE FRIDAY NIGHT INTO SATURDAY WITH
ANOTHER APPROACHING SYSTEM OVER THE WEEKEND.
&&
.HYDROLOGY...
LOW TRACK AND THEREFORE ASSOCIATED QPF WITH THE MID WEEK STORM
HAVE TRENDED NORTHWARD...SO ONLY EXPECT BASIN AVG QPF OF 1/2 TO 1
INCH FOR SOUTHERN CT...THE LOWER HUDSON VALLEY AND INTERIOR NE
NJ. LOWER QPF OF 1/4 TO 1/2 INCH EXPECTED FOR NYC METRO AND LONG
ISLAND. LOCAL AMTS OF ABOUT 1/2 INCH HIGHER ARE POSSIBLE
IN TSTMS. THE BULK OF THIS PRECIP SHOULD BE RAIN.
&&
.EQUIPMENT...
THE NOAA WEATHER RADIO TRANSMITTER THAT SERVES THE NEW YORK CITY
METROPOLITAN AREA REMAINS OUT OF SERVICE DUE TO RADIO FREQUENCY
INTERFERENCE WITH THE U.S COAST GUARD TRANSMITTER.
FOR MORE INFORMATION SEE THE FOLLOWING PUBLIC INFORMATION
STATEMENT (ALL LOWER CASE):
WWW.ERH.NOAA.GOV/OKX/PRODUCTS/STATIC.TXT
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR
ANZ330-335-338-340-345-350-353-355.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR ANZ350.
&&
$$
SYNOPSIS...GOODMAN/SEARS
NEAR TERM...GOODMAN/PICCA
SHORT TERM...GOODMAN/PICCA
LONG TERM...GOODMAN/PICCA/SEARS
AVIATION...DW
MARINE...GOODMAN/PICCA/SEARS
HYDROLOGY...GOODMAN
EQUIPMENT...//
AREA FORECAST DISCUSSION
NWS NEW YORK NY
450 AM EDT TUE MAR 11 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD ACROSS THE AREA TODAY.
STRONG LOW PRESSURE WILL THEN MOVE THROUGH WEDNESDAY INTO
WEDNESDAY NIGHT...FOLLOWED BY BUILDING HIGH PRESSURE THURSDAY
THROUGH FRIDAY. A COLD FRONT WILL PASS THROUGH ON SATURDAY...
WITH HIGH PRESSURE BUILDING IN BRIEFLY ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK COLD FRONT WAS JUST WEST OF THE AREA AS OF 08Z. THE FRONT
SHOULD MOVE THROUGH BY DAYBREAK...FOLLOWED BY DOWNSLOPE WNW FLOW
THAT ALONG WITH PARTIAL SUNSHINE SHOULD HELP BOOST TEMPS TO 55-60
ACROSS NYC METRO AND MOST OF LONG ISLAND...AND 50-55 TO THE
NORTH...SEVERAL DEGREES WARMER THAN A 00Z GFS/NAM MOS GUIDANCE
BLEND. THE 06Z RAP SUGGESTS THAT TEMPS COULD EVEN REACH THE LOWER
60S INVOF NYC WITH ENOUGH AFTERNOON SUNSHINE...BUT HAVE DOUBTS AS
TO WHETHER IT WILL GET THIS WARM AS MID LEVEL CLOUDS WILL BE
INCREASING LATE THIS AFTERNOON AHEAD OF THE APPROACHING STORM.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
CLOUDS WILL LOWER/THICKEN TONIGHT ESPECIALLY NORTH/WEST OF NYC...
AHEAD OF LOW PRESSURE DEVELOPING IN THE OH VALLEY. OVERRUNNING
LIGHT PRECIP SHOULD ALSO MOVE INTO AREAS MAINLY NORTH/WEST OF NYC
AFTER MIDNIGHT. HAVE TRENDED WARMER TONIGHT...WITH LOWS 40-45
INVOF NYC AND 35-40 ELSEWHERE...AND WITH ELEVATED WARM NOSE
MOVING IN PRECIP SHOULD START OFF AS RAIN THROUGHOUT.
GFS/ECMWF RELATIVELY CLOSE ON DETAILS WED INTO WED NIGHT AS THE
INTENSIFYING LOW MOVES OUT OF THE OHIO VALLEY AND PASSES NW OF NYC
BY WED EVENING. THE BULK OF THE RAIN ON WED SHOULD BE NORTH OF THE
LOW TRACK DURING THE DAYTIME IN THE COOL SECTOR. AS THE SUB-980 MB
SFC LOW TRACKS OVER THE AREA JUST NW OF NYC AND THE COAST LATE WED
AFTERNOON/EVENING...MOST IF NOT ALL THE CWA COULD GET INTO THE
WARM SECTOR...WITH TEMPS RISING INTO THE 50S MAINLY ACROSS NYC
METRO...NE NJ AND THE LOWER HUDSON VALLEY WHERE MARINE INFLUENCE
WILL BE MINIMAL. A LINE OF FORCED LOW TOPPED CONVECTION IS LIKELY
ALONG A TRAILING COLD FRONT...WHICH COULD PRODUCE STRONG WIND
GUSTS ESPECIALLY ACROSS NE NJ AND NYC METRO WHERE SFC INSTABILITY
LIKELY TO BE SFC-BASED AS BOTH TEMPS/DEWPOINTS RISE INTO THE 50S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MUCH COLDER AIR WILL MOVE IN BEHIND THE INTENSE LOW WED NIGHT AS
IT DEPARTS TO THE GULF OF MAINE...WITH LOWS 20-25 AND POSSIBLY
FALLING TO THE UPPER TEENS WELL INLAND. GIVEN THE MORE NORTHERLY
LOW TRACK...HEAVIER PRECIP SHOULD ALSO REMAIN TO THE NORTH...SO
LITTLE IF ANY ACCUMULATION EXPECTED LATE WED NIGHT AS PRECIP
CHANGES OVER TO LIGHT SNOW OR SCT SNOW SHOWERS.
THU AND THU NIGHT WILL BE BLUSTERY AND VERY COLD...WITH TEMPS NOT
RISING MUCH IF AT ALL...REACHING THE MID AND UPPER 20S AT
BEST. NW WINDS COULD REACH ADVY CRITERIA ESPECIALLY ACROSS NYC
METRO AND LONG ISLAND. LOWS THEN EXPECTED TO FALL TO THE SINGLE
DIGITS INLAND...TEENS MOST ELSEWHERE...AND LOWER 20S IN NYC.
SEE CLIMATE SECTION FOR DETAILS ON RECORD COLD.
THIS VERY COLD AIR MASS WILL BE SHORT LIVED...AS DEEP LAYER
RIDGING BUILDS ACROSS WITH SW RETURN FLOW AND WAA ON FRI.
LOW PRESSURE MOVING THROUGH SOUTHERN CANADA LATE FRI INTO SAT WILL
DRAG A TRAILING COLD FRONT THROUGH BY MIDDAY SAT. SOME QUESTION
ON THE EXTENT OF PCPN WITH THIS SYSTEM AS VERY DRY AIR INITIALLY IN
PLACE WILL BE HARD TO OVERCOME. BETTER FORCING ALSO LOOKS TO BE TO
THE NORTH...SO HAVE ONLY MENTIONED SLIGHT CHANCE POP.
SUNDAY SHOULD BE DRY.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
WEAK TROF/COLD FRONT MOVES ACROSS THE TERMINALS THE NEXT FEW
HOURS...CLEARING THE EASTERNMOST TERMINAL KGON BY 09Z. S-SW WINDS
WILL VEER AROUND TO THE W-NW BEHIND THE BOUNDARY. FLOW WILL BE
RIGHT AROUND 310 FROM MID MORNING TO MID AFTERNOON AT 7 TO 10
KT...BEFORE BACKING A BIT BY LATE AFT TO THE W. AN OCCASIONAL GUST
UP TO 15 KT IS POSSIBLE DURING THE LATE MORNING AND EARLY AFT
HOURS. RIDGE AXIS BUILDS INTO THE AREA TUE EVE WITH A LIGHT AND
VARIABLE FLOW.
VFR CONDITIONS ARE FORECAST THROUGH THE PERIOD. THERE IS SOME CONCERN
FOR MVFR CIGS DEVELOPING DURING THE 06Z TO 12Z TUE TIME FRAME FOR
THE 30H TAFS AHEAD OF AN APPROACHING WARM FRONT.
.OUTLOOK FOR 06Z WED THROUGH SAT...
.WED-WED NIGHT...SUB-VFR LIKELY IN RA. ESE-SE WINDS AROUND 10 KT
GUSTING UP TO AROUND 20 KT LATE WED AFTN-EVE THEN W-NW WINDS
AROUND 20 KT GUSTING UP TO 35 KT LATER WED NIGHT.
.THU...IMPROVING TO VFR EARLY. NW G30-40KT.
.FRI...VFR.
.SAT...SUB-VFR POSSIBLE IN SHOWERS.
&&
.MARINE...
WINDS STARTING TO BACK SW AND GUST OVER 20 KT AT 44017. SHOULD SEE
MINIMAL SCA CONDS FROM THERE ON EAST THIS MORNING...SO SCA
REMAINS IN EFFECT ONLY ON THE OCEAN E OF MORICHES INLET.
WINDS AND SEAS INCREASE ON WED WITH SOUTHERLY FLOW. SCA CRITERIA
ARE LIKELY TO BE REACHED DURING THE SECOND HALF OF THE DAY.
WINDS AND SEAS CONTINUE TO INCREASE INTO WEDNESDAY NIGHT...WITH
GALES EXPECTED TO DEVELOP. THEREFORE...WENT AHEAD AND ISSUED A WATCH
CONSIDERING THE HIGH AMOUNT OF CONFIDENCE IN THE STRENGTHENING WINDS
WITH THE DEEPENING LOW PRESSURE MOVING OFF TO THE EAST. GALES THEN
LOOK TO END THURSDAY NIGHT...BUT WINDS AND SEAS STILL REMAIN
ELEVATED...WITH 5 FT SEAS NOT DIMINISHING ACROSS THE EASTERN
OCEAN WATERS UNTIL AT LEAST FRIDAY MORNING.
SCA CONDITIONS POSSIBLY RETURN LATE FRIDAY NIGHT INTO SATURDAY WITH
ANOTHER APPROACHING SYSTEM OVER THE WEEKEND.
&&
.HYDROLOGY...
LOW TRACK AND THEREFORE ASSOCIATED QPF WITH THE MID WEEK STORM
HAVE TRENDED NORTHWARD...SO ONLY EXPECT BASIN AVG QPF OF 1/2 TO 1
INCH FOR SOUTHERN CT...THE LOWER HUDSON VALLEY AND INTERIOR NE
NJ. LOWER QPF OF 1/4 TO 1/2 INCH EXPECTED FOR NYC METRO AND LONG
ISLAND. LOCAL AMTS OF ABOUT 1/2 INCH HIGHER ARE POSSIBLE
IN TSTMS. THE BULK OF THIS PRECIP SHOULD BE RAIN.
&&
.CLIMATE...
RECORD LOW TEMPS ARE LIKELY TO BE TIED OR BROKEN AT MOST LOCAL
CLIMATE SITES THU AND THU NIGHT...
TEMPS FOR THU MAR 13...
RECORD LOW
MAXIMUM FCST
NEWARK.........32 IN 1980 32
BRIDGEPORT.....33 IN 1980 28
CENTRAL PARK...27 IN 1896 30
LAGUARDIA......33 IN 1980 31
KENNEDY........33 IN 1980 30
ISLIP..........34 IN 1989 28
TEMPS FOR FRI MAR 14...
RECORD LOW
MINIMUM FCST
NEWARK.........17 IN 1980 17
BRIDGEPORT.....16 IN 1980 13
CENTRAL PARK... 8 IN 1896 19
LAGUARDIA......18 IN 1980 22
KENNEDY........19 IN 1980 18
ISLIP..........17 IN 1989 13
&&
.EQUIPMENT...
THE NOAA WEATHER RADIO TRANSMITTER THAT SERVES THE NEW YORK CITY
METROPOLITAN AREA REMAINS OUT OF SERVICE DUE TO RADIO FREQUENCY
INTERFERENCE WITH THE U.S COAST GUARD TRANSMITTER.
FOR MORE INFORMATION SEE THE FOLLOWING PUBLIC INFORMATION
STATEMENT (ALL LOWER CASE):
WWW.ERH.NOAA.GOV/OKX/PRODUCTS/STATIC.TXT
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING FOR
ANZ330-335-338-340-345-350-353-355.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR ANZ350.
&&
$$
SYNOPSIS...GOODMAN/SEARS
NEAR TERM...GOODMAN/PICCA
SHORT TERM...GOODMAN/PICCA
LONG TERM...GOODMAN/PICCA/SEARS
AVIATION...JMC/DW
MARINE...GOODMAN/PICCA/SEARS
HYDROLOGY...GOODMAN
CLIMATE...PICCA
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS POCATELLO ID
930 AM MDT TUE MAR 11 2014
.UPDATE...UPPER TROUGH DROPPING SOUTH ACROSS EAST IDAHO TODAY.
AREA WEB CAMS STILL SHOW LIGHT SNOWS MOVING MAINLY THROUGH EASTERN
HIGHLANDS IN LINE WITH EARLY NAM. NAM AND HRRR SWING REMNANT
MOISTURE THROUGH THE SNAKE PLAIN SOUTHWEST INTO THE EASTERN MAGIC
VALLEY AND SOUTHERN HIGHLANDS THIS AFTERNOON...PAINTING LIGHT
QPF ACROSS THE REGION. LOCAL WRF AND GFS ALSO PAINT BAND OF MID
LEVEL MOISTURE ACROSS THE REGION...WHICH COULD BE ENOUGH TO
INITIATE PRECIPITATION WITH EMBEDDED STRATUS CURRENTLY IN PLACE.
WILL LEAVE THE WEAK ISOLATED POPS IN PLACE ALONG AND SOUTH OF
INTERSTATE CORRIDOR THROUGH SNAKE PLAIN. HIGHER POPS WILL STAY IN
PLACE OVER SOUTHERN HIGHLANDS WHERE FAVORABLE UPSLOPE CONDITIONS
WILL BE IN PLACE THIS AFTERNOON AS SURFACE TROUGH SLIDES SOUTH
AND GRADIENT TURNS MORE NORTHERLY. FOR NOW...NO UPDATES TO CURRENT
FORECAST. DMH
&&
.PREV DISCUSSION... /ISSUED 258 AM MDT TUE MAR 11 2014/
SHORT TERM...TODAY THROUGH THURSDAY. SNOW SHOWERS REMAIN MAINLY IN THE
EASTERN AND SOUTHERN HIGHLANDS THIS MORNING AS THE UPPER TROUGH
MOVES EAST. A QUICK LOOK AT WEBCAMS IS SHOWING THAT AREAS ALONG THE
DIVIDE UNDER A WINTER STORM WARNING ARE BEGINNING TO CLEAR UP AND
THE THREAT OF BLOWING AND DRIFTING SNOW IS DIMINISHING.
THEREFORE...WILL BE ALLOWING THE WINTER STORM WARNING TO EXPIRE WITH
THIS MORNINGS FORECAST. STILL EXPECTING THINGS TO GRADUALLY TAPER
OFF WITH LINGERING SHOWERS IN THE EXTREME SE CORNER OF IDAHO THIS
AFTERNOON. ALL AREAS ARE EXPECTED TO DRY OUT BY THIS EVENING. AS THE
WEEK WEARS ON...SE ID WEATHER WILL BE DOMINATED BY A DRIER NW FLOW
AS A RIDGE DEVELOPS OVER THE EASTERN PACIFIC. MODELS SHOWING A
SHORTWAVE PASSING ALONG THE DIVIDE ON THURSDAY BUT AT THE MOMENT IT
LOOKS TO BE RELATIVELY DRY SO AS OF NOW...JUST EXPECTING SOME
PASSING CLOUDS. OTHERWISE...TEMPERATURES EXPECTED TO GRADUALLY WARM
A FEW DEGREES EACH DAY WITH VALLEY HIGHS IN THE 50S. EP
LONG TERM...FRIDAY THROUGH TUESDAY. THE GFS/ECMWF ARE FAIRLY
CONSISTENT WITH THE IDEA THAT A FLAT UPPER RIDGE WILL REMAIN
POSITIONED OVER THE COAST AS A FEW PAC STORM SYSTEMS BREAK OVER THE
RIDGE AXIS INTO THE NRN ROCKIES. THE FIRST IS EXPECTED TO ADVANCE
THROUGH THE NRN ROCKIES FRIDAY AFTERNOON THROUGH SATURDAY AFTERNOON
WITH VALLEY RAIN/MOUNTAIN SNOW IMPACTING MAINLY THE CNTRL MOUNTAINS
AND ERN HIGHLANDS. THE SECOND STORM WILL ARRIVE MONDAY WITH THE GFS
INDICATING A FAIRLY SHALLOW WAVE BRUSHING THE DIVIDE REGION WHEREAS
THE ECMWF IS ADVERTISING A MUCH DEEPER WAVE DIGGING THROUGH SRN
IDAHO WITH A VIGOROUS SHOT OF PRECIPITATION FOR SE IDAHO. HAVE
MAINTAINED THE GOING GRIDS WHICH ESSENTIALLY FOLLOWED THE GFS TIMING
AND STRENGTH. WILL CONTINUE TO WATCH THE GFS TO SEE IF IT MAKES A
MOVE TOWARD THE STRONGER ECMWF FOR MONDAY. TEMPS GENERALLY RUNNING
WELL ABOVE NORMAL THROUGH THE PERIOD. HUSTON
AVIATION...THE UPPER TROUGH AXIS WAS SHIFTING INTO THE WYOMING
BORDER REGION EARLY THIS MORNING WHILE RADAR CONTINUED TO SHOW A
BROAD AREA OF MODEST SNOWFALL ACROSS THE SE HIGHLANDS. MODELS
SUGGEST THAT AS THE RIDGE BUILDS ALONG THE COAST THIS MORNING...THE
FLOW WILL TURN MORE NORTHERLY ACROSS SE IDAHO RESULTING IN A LINE OF
WIND CONVERGENCE WORKING DOWN THE VALLEY STARTING NEAR KRXE AT ABOUT
14Z AND ADVANCING THROUGH KIDA AND KPIH THROUGH 18Z WITH
ACCOMPANYING MVFR CIGS AND REDUCED VIS IN SNOW SHOWERS. BEYOND
21Z...SUBSIDING NE WINDS WILL EFFECTIVELY CLEAR THE REGION OUT WITH
VFR CONDITIONS PREVAILING OVERNIGHT. KSUN SHOULD REMAIN VFR
THROUGHOUT THE ENTIRE FORECAST PERIOD. HUSTON
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS POCATELLO ID
1028 PM MDT MON MAR 10 2014
.UPDATE...SNOW IS TAKING A LITTLE LONGER TO CLEAR THE UPPER SNAKE
HIGHLANDS THIS EVENING. LAST MINUTE CHANGES WILL INCLUDE EXTENDING
THE CURRENT WARNING OUT UNTIL 3 AM MDT AND CANCELLING THE FLOOD
WATCH SINCE EVERYTHING HAS CHANGED OVER TO SNOW. GROUND MAY BE
WARM YET AND STREAMS AS WELL. GAGES SHOW SOME INCREASE ON FALLS
RIVER NEAR CHESTER BUT IT LOOKS LIKE IT WILL TAKE QUITE A BIT MORE
THAN THAT TO CAUSE PROBLEMS. WILL PROBABLY SEE SOME SNOW ON
HIGHWAY 30 NEAR SODA SPRINGS IN THE NEXT COUPLE OF HOURS. RS
&&
.PREV DISCUSSION... /ISSUED 633 PM MDT MON MAR 10 2014/
UPDATE...THE BACK OF THE STORM SYSTEM IS PASSING THROUGH THE
CENTRAL MOUNTAINS. TEMPERATURES ARE COLLING WITH SNOW LEVEL JUST
BEGINNING TO DROP TO AROUND 7700 TO 7900 FEET ELEVATION.
HOWEVER...SNOW ACCUMULATION THE REMAINDER OF THE NIGHT WILL BE
LIMITED TO AN INCH OR SO. THEREFORE THE WINTER STORM WARNING WAS
ALLOWED TO EXPIRE IN THE CENTRAL MOUNTAINS. THE FLOOD WATCH IN THE
KETCHUM AND HAILEY AREA WAS ALSO ALLOWED TO EXPIRE. LIMITED WATER
RISES WERE OBSERVED ON SMALL STREAMS...ESPECIALLY THE EAST FORK OF
THE BIG WOOD RIVER...BUT THIS WAS LESS THE WATER LEVELS OBSERVED A
COUPLE OF DAYS AGO AND NO FLOODING HAS BEEN REPORTED. REMOTE GAGES
REPORT WATER LEVELS ARE LEVELING OFF. RS
PREV DISCUSSION... /ISSUED 115 PM MDT MON MAR 10 2014/
SHORT TERM...TONIGHT THROUGH WEDNESDAY. A STRONG STORM CONTINUES
TO SLOWLY PUSH EAST ACROSS THE WEST. AS THE SYSTEM MOVES OVER
IDAHO...IT WILL ACTUALLY BEGIN TO DIG MORE SOUTH AND SETTLE OVER
SOUTHERN UTAH AND NEVADA BY TOMORROW AFTERNOON. SNOW LEVELS WILL
CONTINUE TO FALL AS A COLD FRONT WORKS ACROSS THE AREA...AND FALL
TO THE VALLEY FLOORS AREAWIDE BY MORNING. STRONG WINDS WILL
CONTINUE IN THE HIGHER ELEVATIONS AND ALSO ACROSS THE SNAKE PLAIN
THIS EVENING. WE ARE ALREADY SEEING LOCALIZED GUSTS IN EXCESS OF
60MPH ACROSS THE PLAIN...BUT MOST GUSTS WILL NOT EXCEED 55MPH. THE
WIND ADVISORY REMAINS IN EFFECT FOR THE SNAKE PLAIN UNTIL 9PM.
HOWEVER...THERE IS SOME INDICATION THAT WE MAY NEED TO EXTEND THAT
UNTIL MIDNIGHT AND PERHAPS EXTEND IT INTO THE SOUTHERN HIGHLANDS
ESPECIALLY AS THE WINDS SWITCH TO THE NORTHWEST. IN TERMS OF
PRECIPITATION...THE PATTERN BECOMES RATHER COMPLEX THIS EVENING.
IN TERMS OF THE MOUNTAINS...WE WILL SEE TWO DISTINCT AREAS OF
ENHANCED MOISTURE. THE FIRST IS ACROSS THE UPPER SNAKE HIGHLANDS
AND SOUTHWARD TOWARD BEAR LAKE. THE OTHER IS IN NORTHWEST FLOW
ACROSS CENTRAL MOUNTAINS FROM CHALLIS TO GALENA SUMMIT. THE BIGGER
AMOUNTS OVERALL WILL FALL OVER THE EAST. THE THIRD AREA IS A
COMBINATION OF CONVERGENCE AND UPSLOPE. BY MORNING...AN AREA OF
CONVERGENCE WILL LIE ACROSS THE SNAKE PLAIN NORTH AND EAST OF
CRATERS TO POCATELLO LINE. UPSLOPE WILL ENHANCE THIS MOISTURE BAND
ACROSS THE BENCHES AND ADJACENT MOUNTAINS FROM NEAR ST. ANTHONY TO
AROUND POCATELLO. SNOW LEVELS WILL HOVER AROUND 4500-5000FT SO
THESE AREAS WILL SEE AT LEAST MIX DOWN LOW AND ALL SNOW ABOVE THE
BENCHES. IN TERMS OF ADDITIONAL PRECIPITATION OVERNIGHT...THE
MOUNTAINS WILL SEE 0.10-0.20 INCHES ACROSS THE WEST AND 0.20-0.50
INCHES IN THE EAST. SNOWFALL AMOUNTS WILL BE A TRACE TO 3 INCHES
IN THE MOUNTAINS. SOME BLOWING/DRIFTING IS POSSIBLE IN THE
MOUNTAINS BUT WILL NOT BE WIDESPREAD IT APPEARS. WE MAY SEE A
DUSTING ACROSS THE SNAKE PLAIN ESPECIALLY EAST OF I-15 BUT IT WILL
NOT STICK AROUND LONG. IN TERMS OF WINTER AND FLOOD HEADLINES...WE
WILL LET ALL WATCHES AND WARNINGS RIDE AND WILL LET THE EVENING
SHIFT DECIDE IF ANYTHING NEEDS TO BE EXTENDED.
BY TUESDAY AFTERNOON...WE WILL SEE ANY RAIN OR SNOW CONFINED TO
AROUND BEAR LAKE AND DRIER AIR AND HIGH PRESSURE BUILDS INTO
IDAHO. WE WILL SEE GUSTY NORTH TO NORTHEAST WINDS ACROSS THE
ENTIRE AREA. IT WILL BE A BIT COOLER TOMORROW AS WELL.
TUESDAY NIGHT AND WEDNESDAY WILL BE VERY DRY. WITH THE DRY AREA
MOVING IN...THIS SHOULD ALLOW FOR A VERY CHILLY NIGHT ACROSS THE
AREA AND A DECENT WARMUP ON WEDNESDAY. LOWS WILL LIKELY DROP INTO
THE SINGLE DIGITS FOR HIGHER VALLEYS AND ISLAND PARK...WITH 10S
AND 20S ELSEWHERE. GUIDANCE ACTUALLY POINTS TO EVEN COLDER
TEMPERATURES BUT FOR NOW TRENDED ONLY PARTIALLY THAT DIRECTION.
HIGHS BOUNCE BACK INTO 40S/LOWS 50S IN THE VALLEYS AND LOW/MID 30S
AT RIDGETOP. KEYES
LONG TERM...THU NIGHT THROUGH NEXT MON NIGHT. LONGWAVE PATTERN
INDICATES A HIGH AMPLITUDE RIDGE TO THE WEST OF IDAHO THAT SLOWLY
DE-AMPLIFIES AND SHIFTS TO THE COAST STARTING SAT NIGHT. THERE ARE A
COUPLE OF WEAK TROUGHS THAT MOVE DOWN THE BACKSIDE OF THE
RIDGE...THE MOST LIKELY ONE TO AFFECT THE FORECAST AREA IS A FRI
NIGHT/SAT SHORTWAVE. ZERO TO LITTLE EFFECT IS EXPECTED SOUTH OF
POCATELLO...AND ONLY LITTLE EFFECT NORTH OF THIS. THE MAIN FORECAST
PROBLEM IS HOW WARM IT WILL GET...WITH THE ECMWF BEING COLDER AND
CLOUDIER. HAVE SPLIT THE DIFFERENCE...WHICH GETS LARGE BEYOND THE
FRI NIGHT TROUGH. NO REAL SIGNIFICANT WIND WITH TEMPS GENERALLY
ABOVE SEASONAL NORMALS. MESSICK
AVIATION...WIND HAVING A HARD TIME DEVELOPING...AND SUN VALLEY JUST
BELOW FIELD MINIMUMS. LOWEST CIGS EXPECTED WITH FRONTAL PASSAGE
DURING THE MID- TO LATE AFTERNOON. FOR ALL AIRDROMES. LOWEST CIGS
EXPECTED ARE MARGINAL VFR. HRRR GUIDANCE OF LATE NOW SUGGESTS
STRONG WINDS SHORTLY AFTER 11/01Z IN THE KPIH AREA. SHOULDN`T BE MUCH
OF A PROBLEM SINCE THEY ARE ALIGNED WITH THE RUNWAY. SKIES SHOULD
CLEAR DURING THE LATE EVENING HOURS. MESSICK
HYDROLOGY...MODERATE TO HEAVY RAINFALL BELOW 6500 FEET COMBINED
WITH MELTING SNOW WILL CREATE AN INCREASED THREAT OF FLOODING FOR
SMALL STREAMS AND LOW LYING AREAS IN THE BIG AND LITTLE WOOD RIVER
REGION AND THE UPPER SNAKE HIGHLANDS FOR THE NEXT SEVERAL HOURS. THESE
AREAS INCLUDE THE CITIES OF KETCHUM...HAILEY... ASHTON AND ST
ANTHONY. A FLOOD WATCH REMAINS IN EFFECT FOR THESE AREAS. FLOODING
IS NOT EXPECTED FOR THE MAIN STEM RIVERS AT THIS TIME. WYATT
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH UNTIL MIDNIGHT MDT TONIGHT BELOW 6500 FEET FOR THE
IDZ019.
WINTER STORM WARNING UNTIL MIDNIGHT MDT TONIGHT ABOVE 7000 FEET
FOR THE IDZ019.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
247 PM CDT TUE MAR 11 2014
.DISCUSSION...
1234 PM CDT
WINTER STORM UPDATE...
CONTINUING TO ASSESS 12Z MODEL DATA FOR IMPENDING WINTER STORM.
SURFACE OBSERVATION ANALYSIS SHOWS 996 MB LOW IN CENTRAL KS
ROUGHLY BETWEEN SLN AND HUT...NORTH OF LATEST RUN OF RAP MODEL.
TRENDS SO FAR SUPPORT THE AXIS OF HEAVIEST SNOW IN GOING FORECAST
AND HAVENT MADE ANY CHANGES TO THIS YET...WITH ONLY TWEAKS TO LATE
AFTERNOON POPS AS BAROCLINIC ZONE STARTS TO SHIFT SOUTH AND RAIN
COMMENCES IN FAR NORTHERN CWA. RAIN SHOULD QUICKLY FLIP OVER TO
SNOW THIS EVENING IN NORTHERN ILLINOIS AS COLDER AIR FILTERS IN
FROM THE NORTH.
OF BIGGEST CONCERN WITH THE SNOW LATE TONIGHT IS THE BAND OF VERY
STRONG 850-700 MB FGEN OVERLAID BY NEGATIVE EPV...AS WELL AS THE
PRESENCE OF 50-100 J/KG OF MUCAPE. THIS HIGHLIGHTS POTENTIAL FOR
CONVECTIVE SNOW BANDS AND RATES OF 2 INCHES PLUS PER HOUR
WHEREVER THIS SETS UP. KEEPING TOTALS IN CHECK WILL BE
PROGRESSIVE NATURE OF SYSTEM WITH MIDLEVEL TROUGH REMAINING
OPEN...SO WOULD ONLY EXPECT A FEW HOUR PERIOD WITH THE REALLY
HEAVY RATES IN ANY GIVEN AREA. NONETHELESS...COULD SEE SOME
ISOLATED TOTALS TO OR EVEN A BIT ABOVE 8 INCHES IN WARNING
AREA...WITH THIS MOST LIKELY TO OCCUR ROUGHLY ALONG AND A BIT EAST
OF I-55 CORRIDOR.
LIKELY BECAUSE OF BANDING POTENTIAL...HIGHER RES GUIDANCE SHOWING
A VERY SHARP CUTOFF TO PRECIP IN NORTHERN CWA...AND THINK THIS IS
OVERDONE...BUT THERE WILL BE A GRADIENT IN SNOW AMOUNTS ROUGHLY IN
LINE WITH GOING FORECAST. FARTHER SOUTH IN WATCH
AREA...UNCERTAINTY REMAINS OVER HOW FAST CHANGEOVER WILL OCCUR AND
HOW MUCH PRECIP WILL FALL AFTER CHANGEOVER...SO WILL MAKE A
DECISION ON HEADLINE FOR SOUTHEAST CWA WITH AFTERNOON ISSUANCE.
FINALLY...WINDS REMAIN A SIGNIFICANT CONCERN AS WELL LATE TONIGHT
INTO WEDNESDAY MORNING...WITH SOUNDINGS SUPPORTING NORTHERLY WIND
GUSTS TO 40+ MPH. THIS WILL EXACERBATE IMPACTS TO WEDS AM COMMUTE
EVEN AS SNOW WINDS DOWN.
RC/JEE
//PREV DISCUSSION...
343 AM CDT
THE TASTE OF SPRING YESTERDAY IS TRULY IN THE REAR VIEW MIRROR AS
THE FORECAST FOCUS WAS ON WINTER STORM SET TO IMPACT THE AREA
TONIGHT INTO EARLY WEDNESDAY. HAVE ISSUED A WINTER STORM WARNING
CENTERED ON THE I-80 CORRIDOR...AND THAT INCLUDES CHICAGO...FOR THE
COMBINATION OF HEAVY SNOWFALL RATES OF UP TO 2 INCHES PER
HOUR...SNOW TOTALS AROUND SIX INCHES...AND WIND WHIPPED SNOW
GREATLY REDUCING VISIBILITY. CONTINUE THE WATCH SOUTH OF THERE AND
AN ADVISORY TO THE NORTH.
THE PRIMARY UPPER LOW IS WELL-DEFINED THIS MORNING ACROSS WYOMING
AND ADVANCING SOUTHEAST WITH OVER 200M HEIGHT FALLS AT 300MB SAMPLED
LAST EVE. SECOND KEY SHORT WAVE IS DROPPING SOUTHWARD FROM MANITOBA.
THE PHASING OF THESE SYSTEMS IS ANTICIPATED TO OCCUR ACROSS THE
WESTERN GREAT LAKES OVERNIGHT INTO WEDNESDAY MORNING. AS OFTEN SEEN
WITH PHASING SYSTEMS...FORCING FOR LIFT AND HEAVY PRECIP IS EXPECTED
TO RAPIDLY INCREASE TONIGHT. NUMERICAL GUIDANCE HAS HAD SOME
PRONOUNCED DIFFERENCES AND THAT CONTINUED INTO THE 11.00Z AND
11.06Z CYCLES...BUT IT IS IMPORTANT TO NOTE THAT ALL GUIDANCE
DEPICT ALL THE INGREDIENTS FOR HEAVY SNOWFALL AND THAT ARE
CONSISTENT WITH A PHASING SYSTEM. HAVE PREFERRED THE GLOBAL GUIDANCE
SOLUTION OF MASS FIELDS AND TAKEN INTO ACCOUNT THE MRF AND LOCAL
HIGH RES MODELS IDEAS OF MESOSCALE VERY HEAVY SNOWFALL RATES AND
TIMING. BELIEVE THE MRF IS A LITTLE TOO ROBUST AND WIDESPREAD
WITH ITS HEAVIEST QPF...BUT AGAIN THE IDEA OF HEAVY SNOWFALL WITH
AMOUNTS EXCEEDING SIX INCHES IN AN AREA IS SUPPORTED.
TODAY...
THIS STILL LOOKS MAINLY DRY ACROSS THE FORECAST AREA WITH A VERY
SHARP MID-LEVEL STATIONARY FRONT SAMPLED ON LAST EVES RAOBS BECOMING
MORE ACTIVE AHEAD OF THE APPROACHING TROUGHS. EARLY MORNING RADAR
MOSAIC INDICATES PRECIP FROM SD THROUGH WESTERN WI. THIS SHOULD ONLY
INCH SOUTHWARD GRADUALLY TODAY. FRONTOGENESIS RESPONSE FROM EVEN THE
MOST SOUTH HIGH RESOLUTION GUIDANCE WOULD KEEP RAIN NORTH OF THE
AREA THROUGH MID-AFTERNOON. STILL SHOULD SEE PLENTY OF CLOUD
COVER AND WITH NORTHEAST WINDS INCREASING AHEAD OF CYCLOGENESIS IN
THE PLAINS...EXPECT THAT SURFACE TEMPERATURES WILL START TO LEVEL
OUT AROUND THE NOON HOUR AND THEN BEGIN TO GRADUALLY FALL. ONSHORE
FLOW INTO CHICAGO OFF THE ICE-COVERED LAKE MAY LEAD TO A MORE RAPID
FALL DOWNTOWN.
TONIGHT AND WEDNESDAY MORNING...
IN RESPONSE TO THE AFOREMENTIONED PHASING...MAXIMUM HEIGHT FALLS ARE
CENTERED DIRECTLY ON THE AREA TONIGHT WITH LIFT RAPIDLY INCREASING.
THIS WILL EVOLVE THE LOW-LEVEL FEATURES EASTWARD WITH COPIOUS
MOISTURE TRANSPORTED NORTH OF A 40-45 KT LOW-LEVEL JET. PRECIP FROM
THE NORTH IS EXPECTED TO QUICKLY MOVE SOUTH...WHILE NEW PRECIP
SHOULD DEVELOP JUST WEST OR OVER THE AREA THIS EVE. THE DEGREE OF
FORCING AND COOL ADVECTION IN THE NORTHEAST QUADRANT OF THE SYSTEM
WILL HELP TO COOL THE COLUMN FROM NORTH TO SOUTH FOR A TRANSITION OF
RAIN TO SNOW...AND THIS WILL BE ESPECIALLY TRUE DURING THE MID EVE
INTO EARLY OVERNIGHT AS THE MOST ROBUST FORCING MOVES IN. WOULD
EXPECT SOME AREAS OF NORTHERN ILLINOIS MAY JUST BEGIN AS SNOW OR
EXPERIENCE A VERY SHORT MIX. AS FOR AREAS ALONG AND SOUTH OF
I-80...A COUPLE/SEVERAL HOUR WINDOW OF RAIN WILL BE LIKELY FIRST
BEFORE TRANSITIONING TO A WET SNOW LATE THIS EVE INTO EARLY
OVERNIGHT. THAT TIME PERIOD AFTER TRANSITION AND INTO OVERNIGHT IS
MOST FAVORED FOR HEAVY SNOWFALL...WITH UPRIGHT INSTABILITY FORECAST
BY GLOBAL MODELS TO REACH INTO THE CENTRAL FORECAST AREA...WHICH
LINES UP WITH THE DEEPEST CONVERGENCE AND FOCUS NEAR I-80. THE
11.03Z SREF PROBABILITIES OF OVER ONE INCH PER HOUR SNOWFALL RATES
ARE TO 70 PERCENT WHICH IS IMPRESSIVE AND MAKE SENSE...AND WOULD NOT
BE SURPRISED TO SEE TEMPORARY TWO INCH PER HOUR OR HIGHER RATES LATE
THIS EVE INTO OVERNIGHT. THE WINDS LOOK TO REALLY RAMP UP OVERNIGHT
AROUND THE DEEPENING LOW...WITH 45 KT OF NORTHEAST FLOW ON THE NAM
AND GFS AT 1000-2000 FT. EVEN WITH THE WET SNOW...EXPECT THAT THE
BLOWING OF THE FALLING SNOW WILL CAUSE EVEN FURTHER REDUCED
VISIBILITY...AND EVEN TEMPORARY WHITE OUT CONDITIONS IN THE HEAVIEST
OF SNOWFALL RATES.
BY WEDNESDAY MORNING SNOW SHOULD BE ENDING FROM WEST TO
EAST...ALTHOUGH SOME PRETTY SOLID RATES COULD STILL BE OCCURRING IN
EASTERN AREAS...INCLUDING POSSIBLY CHICAGO INTO THE EARLY PARTS OF
THE MORNING COMMUTE. UNCERTAINTY ON END TIME OF SNOWFALL IS FAIRLY
HIGH...BUT THE WINDS SHOULD CONTINUE AND SO EXPECT IMPACTS...AND
THAT MAY BE ESPECIALLY TRUE NEAR THE LAKE SHORE WHERE THE WIND COULD
GUST TO 40-45 MPH. THAT IS WHY RUN HEADLINES THROUGH NOON.
WITH THE HIGH MOISTURE...AS DEPICTED BY MIXING RATIOS OF 4-6 G/KG
AND PWATS OF AROUND 0.75 IN...THERE SHOULD NOT BE TOO MUCH OF A
PROBLEM WITH SNOWFALL AMOUNTS IN THE MAXIMUM AREA TOPPING SIX
INCHES...EVEN WITH THE QUICK MOVEMENT OF THE SYSTEM AND LOW
SNOW-TO-LIQUID RATIOS. THE HIGHEST AMOUNTS COULD EXCEED 8 INCHES IN
ISOLATED AREAS...BUT AGAIN LIMITED DURATION SHOULD PREVENT THAT FROM
BEING TOO WIDESPREAD.
HEADLINES...
GIVEN RATES AND BLOWING OF THE FALLING SNOW...WITH BASICALLY A
DOWNPOUR OF SNOW WITH CONCURRENT GUSTS OF 30+ MPH...HAVE OPTED TO GO
WITH A WARNING FOR THE AREA WITH THE LONGEST DURATION OF SNOW....EVEN
THOUGH NOT EVERYWHERE WILL SEE SIX PLUS INCHES OF SNOW.
UNCERTAINTY OF SNOW DURATION IN THE FAR SOUTH LED TO CONTINUING
THE WATCH. FURTHER NORTH HAVE AN ADVISORY...AND DID NOT INCLUDE
ROCKFORD BECAUSE IT LOOKS LIKE SNOWFALL SHOULD HAVE ENDED BY MUCH
OF IF NOT THE ENTIRE WED MORNING COMMUTE. IT IS CERTAINLY POSSIBLE
ADJUSTMENTS TO THE NORTHERN END OF HEADLINES ARE MADE TODAY.
WEDNESDAY NIGHT AND THURSDAY...
NOT MUCH CHANGE MADE TO THIS PERIOD. WEDNESDAY NIGHT LOOKS TO BE
PRETTY CHILLY WITH THE FRESH SNOW COVER AND DIMINISHING WINDS...AND
IF THE SKY CAN REMAIN CLEAR THE LOWS MAY BE WITHIN FIVE DEGREES OF
RECORD LOWS FOR MARCH 13TH.
MTF
EXTENDED FORECAST...FRIDAY THROUGH TUESDAY...
210 PM CDT...
FOR THE EXTENDED FORECAST PERIOD...THE MAIN ISSUE WILL BE
TEMPERATURES ACROSS THE REGION. THE LONGER RANGE GUIDANCE IS
SUGGESTING THAT THE MAIN FEATURES OF INTEREST WILL BE A PAIR OF
CLIPPER DROPPING OUT OF NORTHERN ALBERTA AND TRACKING ACROSS THE
UPPER GREAT LAKES REGION. PERIODS OF WARMING WILL PRECEDE THE
CLIPPERS WITH HIGHS ON FRIDAY IN THE MIDDLE 40S TO LOWER 50S.
FOLLOWING A WEAK COLD FRONTAL PASSAGE ASSOCIATED WITH THE FIRST
CLIPPER WILL BRING TEMPS BACK TO BELOW NORMAL FOR SUNDAY WITH HIGHS
ONLY IN THE UPPER 20S TO MIDDLE 30S. TOWARD THE END OF THE FORECAST
PERIOD...THERE IS THE POTENTIAL FOR TEMPERATURES TO REACH INTO THE
LOWER 50S AHEAD OF THE SECOND CLIPPER. THERE MAY AND UP BEING SOME
TIMING CHANGES WITH THESE SYSTEMS AS WE GET CLOSER TO THE
EVENTS...BUT THE GENERAL SIGNAL IS FOR ABOVE NORMAL TEMPERATURES FOR
MUCH OF THE EXTENDED FORECAST PERIOD...WITH THE EXCEPTION OF THE
PERIOD FOLLOWING THE PASSAGE OF THE FIRST CLIPPER WHICH WILL BRING
BACK A DIP INTO BELOW NORMAL TEMPERATURE RANGES. AS FOR THE
PRECIPITATION OUTLOOK...THIS WILL BE HIGHLY DEPENDENT ON THE TRACKS
OF THE CLIPPERS...BUT AT THIS POINT...IT APPEARS THAT THEY WILL
TRACK TO FAR NORTH TO HAVE MUCH OF AN IMPACT ON NORTHERN ILLINOIS
AND NORTHWEST INDIANA. SO...WILL CARRY DRY FORECAST FOR MUCH OF THE
EXTENDED PERIOD...WITH ONLY SOME SLIGHT CHANCE POPS ON SUNDAY WITH
THE FROPA ASSOCIATED WITH THE PASSAGE OF THE FIRST CLIPPER.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* NORTHEAST WINDS INCREASING TODAY AND TONIGHT WITH GUSTS OF
30-35 KT LIKELY TONIGHT INTO WEDNESDAY MORNING.
* RAIN/SNOW MIX BY MID EVENING...RAPIDLY CHANGING OVER TO ALL SNOW
SOON THERE AFTER.
* RAPIDLY DETERIORATING CONDITIONS IN SNOW WITH VIS/CEILINGS
FALLING TO LIFR/VLIFR.
* PERIOD OF HEAVY SNOW WITH SIGNIFICANTLY REDUCED VIS LIKELY AFTER
MIDNIGHT.
* BLOWING SNOW OVERNIGHT INTO WEDNESDAY MORNING.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
VFR CONDITIONS AND AN INCREASING NORTHEAST WIND IN PLACE OVER THE
TERMINALS EARLY THIS AFTERNOON AS APPROACHING LOW TO THE SOUTHWEST
CONTINUES TO WORK ITS WAY TOWARDS THE AREA. WINDS WILL STEADILY
INCREASE THROUGH THE AFTERNOON AND EVENING WITH HIGHEST GUSTS
EXPECTED OVERNIGHT INTO WEDNESDAY MORNING. VFR CEILINGS WILL LOWER
THIS AFTERNOON BUT THEN QUICKLY DETERIORATE AS BETTER FORCING
ARRIVES THIS EVENING WITH MVFR CONDITIONS BECOMING IFR SOON THERE
AFTER...WITH THESE CEILINGS THEN LIKELY FOR MOST OF THE NIGHT. A
RAIN/SNOW MIX WILL SPREAD OVER THE TERMINALS THIS EVENING BUT
EXPECT A RAPID CHANGE OVER TO ALL SNOW BASICALLY WITHIN AN HOUR OF
ONSET. NO REAL CHANGES TO EXPECTED SNOW TONIGHT AND TIMING WITH
THE 6-10Z TIME FRAME STILL THE BEST TIME FOR MORE MODERATE TO
HEAVY SNOW. HAVE LEFT THE LOWEST VIS AT 1/2 MILE FOR ALL THE
TERMINAL SITES...BUT WITH THEM LIKELY OBSERVING PERIODS OF 1/4
MILE OR EVEN LESS AT TIMES. EXPECT THIS HEAVIER SNOW TO BE MORE
TIED TO CONVECTIVE ASPECTS...WITH UNCERTAINTY TO EXACT TIMING AND
DURATION OF THIS HEAVIER SNOW ASSOCIATED WITH THIS FEATURE.
MDW/GYY WOULD LIKELY HAVE THE BEST CHANCES FOR 1/4 MILE OR LESS
VISIBILITY AS WELL AS FOR A LONGER DURATION AS THIS WILL BE A MORE
FAVORED LOCATION FOR THE BEST SNOWFALL DEVELOPMENT. BUT ONCE
AGAIN...WITH SOME UNCERTAINTY REMAINING...HAVE OPTED TO LEAVE OUT
OF THE TAF AT THIS TIME BUT COULD SEE THIS LOWER VIS IN HEAVY SNOW
ADDED LATER THIS EVENING. BEST SNOW DEVELOPMENT SHOULD EXIT THE
TERMINALS BY EARLY WEDNESDAY MORNING...TAPERING OFF THROUGH THE
MORNING WITH A SLOW IMPROVING TREND WITH CEILINGS.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED/DIRECTION...AND RESULTANT
BLOWING SNOW.
* MEDIUM HIGH CONFIDENCE WITH RAIN/SNOW MIX TIMING AND CHANGE OVER
TO SNOW.
* MEDIUM CONFIDENCE WITH VIS/CEILING TRENDS.
* MEDIUM HIGH CONFIDENCE WITH HEAVY SNOW...LOW MEDIUM CONFIDENCE
WITH TIMING/DURATION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT...DRY/VFR.
* THURSDAY...DRY/VFR. GUSTY SOUTHWEST WINDS.
* FRIDAY...DRY/VFR. GUSTY WESTERLY WINDS.
* SATURDAY...DRY/VFR.
* SUNDAY...SLIGHT CHANCE OF SNOW.
* MONDAY...DRY/VFR.
&&
.MARINE...
210 PM CDT
LOW PRESSURE OVER THE CENTRAL PLAINS WILL CONTINUE TO DEEPEN AS IT
TRACKS EAST ACROSS SOUTHERN ILLINOIS TONIGHT AND INTO THE OHIO
VALLEY WEDNESDAY. AS THE LOW TRACKS SOUTH AND THEN SOUTHEAST OF THE
LAKE...HIGH PRESSURE WILL ALSO BUILD ACROSS THE UPPER GREAT LAKES
REGION...SETTING UP STRONG NORTH WINDS. THE COMBINATION OF A STRONG
GRADIENT AND STRONG COLD ADVECTION WILL LEAD TO WINDS QUICKLY
INCREASING TO GALES BY LATE THIS EVENING. THE LATEST GUIDANCE HAS
BEEN RELATIVELY CONSISTENT IN INDICATING THE POTENTIAL FOR HIGH END
GALES BY LATE WEDNESDAY MORNING AND EARLY AFTERNOON...WITH THE
STRONGEST GALES OVER THE SOUTHERN PORTIONS OF THE LAKE...INCLUDING
THE NEARSHORE WATERS. BY WEDNESDAY EVENING...THE HIGH PRESSURE WILL
BEGIN TO SPREAD ACROSS LAKE MICHIGAN ALLOWING WINDS TO SUBSIDE BELOW
GALE FORCE. BY THURSDAY NIGHT...THE HIGH WILL PUSH TO THE SOUTHEAST
OF THE LAKE AS A CLIPPER DROPS OUT OF NORTHERN ALBERTA AND SWINGS
JUST NORTH OF THE UPPER GREAT LAKES ON FRIDAY. WITH THE SFC HIGH
SAGGING OFF THE SERN COAST...A PERIOD OF SWLY WINDS WILL DEVELOP
AHEAD OF AN APPROACHING COLD FRONT TRAILING FROM THE CLIPPER.
ANTICIPATE A PERIOD OF BRISK SLY TO SWLY WINDS FOR THURSDAY NIGHT
THROUGH FRIDAY...BUT MORE GALES ARE NOT EXPECTED AT THIS TIME. AS
THE CLIPPER TURNS NEWD INTO QUEBEC...IT WILL DRAG A WEAK COLD FRONT
DOWN THE LAKE WITH ANOTHER ARCTIC HIGH BUILDING IN BEHIND THE
FRONT. 25-30KT NORTH WINDS WILL SET UP FOLLOWING THE FROPA FOR
SATURDAY NIGHT AND SUNDAY...BUT AS THE HIGH SPREADS ACROSS THE GREAT
LAKES SUNDAY NIGHT...WINDS SHOULD BECOME MORE LIGHT AND VARIABLE.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032...10 PM TUESDAY TO 1 PM WEDNESDAY.
WINTER STORM WARNING...ILZ033-ILZ039...1 AM WEDNESDAY TO 1 PM
WEDNESDAY.
WINTER WEATHER ADVISORY...ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012...10 PM TUESDAY TO 10 AM WEDNESDAY.
IN...WINTER STORM WARNING...INZ001-INZ002...10 PM TUESDAY TO 1 PM
WEDNESDAY.
WINTER STORM WARNING...INZ010-INZ011-INZ019...1 AM WEDNESDAY TO
1 PM WEDNESDAY.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...MIDNIGHT WEDNESDAY TO 10 PM
WEDNESDAY.
GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...MIDNIGHT WEDNESDAY TO 7 PM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
211 PM CDT TUE MAR 11 2014
.DISCUSSION...
1234 PM CDT
WINTER STORM UPDATE...
CONTINUING TO ASSESS 12Z MODEL DATA FOR IMPENDING WINTER STORM.
SURFACE OBSERVATION ANALYSIS SHOWS 996 MB LOW IN CENTRAL KS
ROUGHLY BETWEEN SLN AND HUT...NORTH OF LATEST RUN OF RAP MODEL.
TRENDS SO FAR SUPPORT THE AXIS OF HEAVIEST SNOW IN GOING FORECAST
AND HAVENT MADE ANY CHANGES TO THIS YET...WITH ONLY TWEAKS TO LATE
AFTERNOON POPS AS BAROCLINIC ZONE STARTS TO SHIFT SOUTH AND RAIN
COMMENCES IN FAR NORTHERN CWA. RAIN SHOULD QUICKLY FLIP OVER TO
SNOW THIS EVENING IN NORTHERN ILLINOIS AS COLDER AIR FILTERS IN
FROM THE NORTH.
OF BIGGEST CONCERN WITH THE SNOW LATE TONIGHT IS THE BAND OF VERY
STRONG 850-700 MB FGEN OVERLAID BY NEGATIVE EPV...AS WELL AS THE
PRESENCE OF 50-100 J/KG OF MUCAPE. THIS HIGHLIGHTS POTENTIAL FOR
CONVECTIVE SNOW BANDS AND RATES OF 2 INCHES PLUS PER HOUR
WHEREVER THIS SETS UP. KEEPING TOTALS IN CHECK WILL BE
PROGRESSIVE NATURE OF SYSTEM WITH MIDLEVEL TROUGH REMAINING
OPEN...SO WOULD ONLY EXPECT A FEW HOUR PERIOD WITH THE REALLY
HEAVY RATES IN ANY GIVEN AREA. NONETHELESS...COULD SEE SOME
ISOLATED TOTALS TO OR EVEN A BIT ABOVE 8 INCHES IN WARNING
AREA...WITH THIS MOST LIKELY TO OCCUR ROUGHLY ALONG AND A BIT EAST
OF I-55 CORRIDOR.
LIKELY BECAUSE OF BANDING POTENTIAL...HIGHER RES GUIDANCE SHOWING
A VERY SHARP CUTOFF TO PRECIP IN NORTHERN CWA...AND THINK THIS IS
OVERDONE...BUT THERE WILL BE A GRADIENT IN SNOW AMOUNTS ROUGHLY IN
LINE WITH GOING FORECAST. FARTHER SOUTH IN WATCH
AREA...UNCERTAINTY REMAINS OVER HOW FAST CHANGEOVER WILL OCCUR AND
HOW MUCH PRECIP WILL FALL AFTER CHANGEOVER...SO WILL MAKE A
DECISION ON HEADLINE FOR SOUTHEAST CWA WITH AFTERNOON ISSUANCE.
FINALLY...WINDS REMAIN A SIGNIFICANT CONCERN AS WELL LATE TONIGHT
INTO WEDNESDAY MORNING...WITH SOUNDINGS SUPPORTING NORTHERLY WIND
GUSTS TO 40+ MPH. THIS WILL EXACERBATE IMPACTS TO WEDS AM COMMUTE
EVEN AS SNOW WINDS DOWN.
RC/JEE
//PREV DISCUSSION...
343 AM CDT
THE TASTE OF SPRING YESTERDAY IS TRULY IN THE REAR VIEW MIRROR AS
THE FORECAST FOCUS WAS ON WINTER STORM SET TO IMPACT THE AREA
TONIGHT INTO EARLY WEDNESDAY. HAVE ISSUED A WINTER STORM WARNING
CENTERED ON THE I-80 CORRIDOR...AND THAT INCLUDES CHICAGO...FOR THE
COMBINATION OF HEAVY SNOWFALL RATES OF UP TO 2 INCHES PER
HOUR...SNOW TOTALS AROUND SIX INCHES...AND WIND WHIPPED SNOW
GREATLY REDUCING VISIBILITY. CONTINUE THE WATCH SOUTH OF THERE AND
AN ADVISORY TO THE NORTH.
THE PRIMARY UPPER LOW IS WELL-DEFINED THIS MORNING ACROSS WYOMING
AND ADVANCING SOUTHEAST WITH OVER 200M HEIGHT FALLS AT 300MB SAMPLED
LAST EVE. SECOND KEY SHORT WAVE IS DROPPING SOUTHWARD FROM MANITOBA.
THE PHASING OF THESE SYSTEMS IS ANTICIPATED TO OCCUR ACROSS THE
WESTERN GREAT LAKES OVERNIGHT INTO WEDNESDAY MORNING. AS OFTEN SEEN
WITH PHASING SYSTEMS...FORCING FOR LIFT AND HEAVY PRECIP IS EXPECTED
TO RAPIDLY INCREASE TONIGHT. NUMERICAL GUIDANCE HAS HAD SOME
PRONOUNCED DIFFERENCES AND THAT CONTINUED INTO THE 11.00Z AND
11.06Z CYCLES...BUT IT IS IMPORTANT TO NOTE THAT ALL GUIDANCE
DEPICT ALL THE INGREDIENTS FOR HEAVY SNOWFALL AND THAT ARE
CONSISTENT WITH A PHASING SYSTEM. HAVE PREFERRED THE GLOBAL GUIDANCE
SOLUTION OF MASS FIELDS AND TAKEN INTO ACCOUNT THE MRF AND LOCAL
HIGH RES MODELS IDEAS OF MESOSCALE VERY HEAVY SNOWFALL RATES AND
TIMING. BELIEVE THE MRF IS A LITTLE TOO ROBUST AND WIDESPREAD
WITH ITS HEAVIEST QPF...BUT AGAIN THE IDEA OF HEAVY SNOWFALL WITH
AMOUNTS EXCEEDING SIX INCHES IN AN AREA IS SUPPORTED.
TODAY...
THIS STILL LOOKS MAINLY DRY ACROSS THE FORECAST AREA WITH A VERY
SHARP MID-LEVEL STATIONARY FRONT SAMPLED ON LAST EVES RAOBS BECOMING
MORE ACTIVE AHEAD OF THE APPROACHING TROUGHS. EARLY MORNING RADAR
MOSAIC INDICATES PRECIP FROM SD THROUGH WESTERN WI. THIS SHOULD ONLY
INCH SOUTHWARD GRADUALLY TODAY. FRONTOGENESIS RESPONSE FROM EVEN THE
MOST SOUTH HIGH RESOLUTION GUIDANCE WOULD KEEP RAIN NORTH OF THE
AREA THROUGH MID-AFTERNOON. STILL SHOULD SEE PLENTY OF CLOUD
COVER AND WITH NORTHEAST WINDS INCREASING AHEAD OF CYCLOGENESIS IN
THE PLAINS...EXPECT THAT SURFACE TEMPERATURES WILL START TO LEVEL
OUT AROUND THE NOON HOUR AND THEN BEGIN TO GRADUALLY FALL. ONSHORE
FLOW INTO CHICAGO OFF THE ICE-COVERED LAKE MAY LEAD TO A MORE RAPID
FALL DOWNTOWN.
TONIGHT AND WEDNESDAY MORNING...
IN RESPONSE TO THE AFOREMENTIONED PHASING...MAXIMUM HEIGHT FALLS ARE
CENTERED DIRECTLY ON THE AREA TONIGHT WITH LIFT RAPIDLY INCREASING.
THIS WILL EVOLVE THE LOW-LEVEL FEATURES EASTWARD WITH COPIOUS
MOISTURE TRANSPORTED NORTH OF A 40-45 KT LOW-LEVEL JET. PRECIP FROM
THE NORTH IS EXPECTED TO QUICKLY MOVE SOUTH...WHILE NEW PRECIP
SHOULD DEVELOP JUST WEST OR OVER THE AREA THIS EVE. THE DEGREE OF
FORCING AND COOL ADVECTION IN THE NORTHEAST QUADRANT OF THE SYSTEM
WILL HELP TO COOL THE COLUMN FROM NORTH TO SOUTH FOR A TRANSITION OF
RAIN TO SNOW...AND THIS WILL BE ESPECIALLY TRUE DURING THE MID EVE
INTO EARLY OVERNIGHT AS THE MOST ROBUST FORCING MOVES IN. WOULD
EXPECT SOME AREAS OF NORTHERN ILLINOIS MAY JUST BEGIN AS SNOW OR
EXPERIENCE A VERY SHORT MIX. AS FOR AREAS ALONG AND SOUTH OF
I-80...A COUPLE/SEVERAL HOUR WINDOW OF RAIN WILL BE LIKELY FIRST
BEFORE TRANSITIONING TO A WET SNOW LATE THIS EVE INTO EARLY
OVERNIGHT. THAT TIME PERIOD AFTER TRANSITION AND INTO OVERNIGHT IS
MOST FAVORED FOR HEAVY SNOWFALL...WITH UPRIGHT INSTABILITY FORECAST
BY GLOBAL MODELS TO REACH INTO THE CENTRAL FORECAST AREA...WHICH
LINES UP WITH THE DEEPEST CONVERGENCE AND FOCUS NEAR I-80. THE
11.03Z SREF PROBABILITIES OF OVER ONE INCH PER HOUR SNOWFALL RATES
ARE TO 70 PERCENT WHICH IS IMPRESSIVE AND MAKE SENSE...AND WOULD NOT
BE SURPRISED TO SEE TEMPORARY TWO INCH PER HOUR OR HIGHER RATES LATE
THIS EVE INTO OVERNIGHT. THE WINDS LOOK TO REALLY RAMP UP OVERNIGHT
AROUND THE DEEPENING LOW...WITH 45 KT OF NORTHEAST FLOW ON THE NAM
AND GFS AT 1000-2000 FT. EVEN WITH THE WET SNOW...EXPECT THAT THE
BLOWING OF THE FALLING SNOW WILL CAUSE EVEN FURTHER REDUCED
VISIBILITY...AND EVEN TEMPORARY WHITE OUT CONDITIONS IN THE HEAVIEST
OF SNOWFALL RATES.
BY WEDNESDAY MORNING SNOW SHOULD BE ENDING FROM WEST TO
EAST...ALTHOUGH SOME PRETTY SOLID RATES COULD STILL BE OCCURRING IN
EASTERN AREAS...INCLUDING POSSIBLY CHICAGO INTO THE EARLY PARTS OF
THE MORNING COMMUTE. UNCERTAINTY ON END TIME OF SNOWFALL IS FAIRLY
HIGH...BUT THE WINDS SHOULD CONTINUE AND SO EXPECT IMPACTS...AND
THAT MAY BE ESPECIALLY TRUE NEAR THE LAKE SHORE WHERE THE WIND COULD
GUST TO 40-45 MPH. THAT IS WHY RUN HEADLINES THROUGH NOON.
WITH THE HIGH MOISTURE...AS DEPICTED BY MIXING RATIOS OF 4-6 G/KG
AND PWATS OF AROUND 0.75 IN...THERE SHOULD NOT BE TOO MUCH OF A
PROBLEM WITH SNOWFALL AMOUNTS IN THE MAXIMUM AREA TOPPING SIX
INCHES...EVEN WITH THE QUICK MOVEMENT OF THE SYSTEM AND LOW
SNOW-TO-LIQUID RATIOS. THE HIGHEST AMOUNTS COULD EXCEED 8 INCHES IN
ISOLATED AREAS...BUT AGAIN LIMITED DURATION SHOULD PREVENT THAT FROM
BEING TOO WIDESPREAD.
HEADLINES...
GIVEN RATES AND BLOWING OF THE FALLING SNOW...WITH BASICALLY A
DOWNPOUR OF SNOW WITH CONCURRENT GUSTS OF 30+ MPH...HAVE OPTED TO GO
WITH A WARNING FOR THE AREA WITH THE LONGEST DURATION OF SNOW....EVEN
THOUGH NOT EVERYWHERE WILL SEE SIX PLUS INCHES OF SNOW.
UNCERTAINTY OF SNOW DURATION IN THE FAR SOUTH LED TO CONTINUING
THE WATCH. FURTHER NORTH HAVE AN ADVISORY...AND DID NOT INCLUDE
ROCKFORD BECAUSE IT LOOKS LIKE SNOWFALL SHOULD HAVE ENDED BY MUCH
OF IF NOT THE ENTIRE WED MORNING COMMUTE. IT IS CERTAINLY POSSIBLE
ADJUSTMENTS TO THE NORTHERN END OF HEADLINES ARE MADE TODAY.
WEDNESDAY NIGHT AND THURSDAY...
NOT MUCH CHANGE MADE TO THIS PERIOD. WEDNESDAY NIGHT LOOKS TO BE
PRETTY CHILLY WITH THE FRESH SNOW COVER AND DIMINISHING WINDS...AND
IF THE SKY CAN REMAIN CLEAR THE LOWS MAY BE WITHIN FIVE DEGREES OF
RECORD LOWS FOR MARCH 13TH.
MTF
EXTENDED FORECAST...FRIDAY THROUGH TUESDAY...
210 PM CDT...
FOR THE EXTENDED FORECAST PERIOD...THE MAIN ISSUE WILL BE
TEMPERATURES ACROSS THE REGION. THE LONGER RANGE GUIDANCE IS
SUGGESTING THAT THE MAIN FEATURES OF INTEREST WILL BE A PAIR OF
CLIPPER DROPPING OUT OF NORTHERN ALBERTA AND TRACKING ACROSS THE
UPPER GREAT LAKES REGION. PERIODS OF WARMING WILL PRECEDE THE
CLIPPERS WITH HIGHS ON FRIDAY IN THE MIDDLE 40S TO LOWER 50S.
FOLLOWING A WEAK COLD FRONTAL PASSAGE ASSOCIATED WITH THE FIRST
CLIPPER WILL BRING TEMPS BACK TO BELOW NORMAL FOR SUNDAY WITH HIGHS
ONLY IN THE UPPER 20S TO MIDDLE 30S. TOWARD THE END OF THE FORECAST
PERIOD...THERE IS THE POTENTIAL FOR TEMPERATURES TO REACH INTO THE
LOWER 50S AHEAD OF THE SECOND CLIPPER. THERE MAY AND UP BEING SOME
TIMING CHANGES WITH THESE SYSTEMS AS WE GET CLOSER TO THE
EVENTS...BUT THE GENERAL SIGNAL IS FOR ABOVE NORMAL TEMPERATURES FOR
MUCH OF THE EXTENDED FORECAST PERIOD...WITH THE EXCEPTION OF THE
PERIOD FOLLOWING THE PASSAGE OF THE FIRST CLIPPER WHICH WILL BRING
BACK A DIP INTO BELOW NORMAL TEMPERATURE RANGES. AS FOR THE
PRECIPITATION OUTLOOK...THIS WILL BE HIGHLY DEPENDENT ON THE TRACKS
OF THE CLIPPERS...BUT AT THIS POINT...IT APPEARS THAT THEY WILL
TRACK TO FAR NORTH TO HAVE MUCH OF AN IMPACT ON NORTHERN ILLINOIS
AND NORTHWEST INDIANA. SO...WILL CARRY DRY FORECAST FOR MUCH OF THE
EXTENDED PERIOD...WITH ONLY SOME SLIGHT CHANCE POPS ON SUNDAY WITH
THE FROPA ASSOCIATED WITH THE PASSAGE OF THE FIRST CLIPPER.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* NORTHEAST WINDS INCREASING TODAY AND TONIGHT WITH GUSTS OF
30-35 KT LIKELY TONIGHT INTO WEDNESDAY MORNING.
* RAIN/SNOW MIX BY MID EVENING...RAPIDLY CHANGING OVER TO ALL SNOW
SOON THERE AFTER.
* RAPIDLY DETERIORATING CONDITIONS IN SNOW WITH VIS/CEILINGS
FALLING TO LIFR/VLIFR.
* PERIOD OF HEAVY SNOW WITH SIGNIFICANTLY REDUCED VIS LIKELY AFTER
MIDNIGHT.
* BLOWING SNOW OVERNIGHT INTO WEDNESDAY MORNING.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
VFR CONDITIONS AND AN INCREASING NORTHEAST WIND IN PLACE OVER THE
TERMINALS EARLY THIS AFTERNOON AS APPROACHING LOW TO THE SOUTHWEST
CONTINUES TO WORK ITS WAY TOWARDS THE AREA. WINDS WILL STEADILY
INCREASE THROUGH THE AFTERNOON AND EVENING WITH HIGHEST GUSTS
EXPECTED OVERNIGHT INTO WEDNESDAY MORNING. VFR CEILINGS WILL LOWER
THIS AFTERNOON BUT THEN QUICKLY DETERIORATE AS BETTER FORCING
ARRIVES THIS EVENING WITH MVFR CONDITIONS BECOMING IFR SOON THERE
AFTER...WITH THESE CEILINGS THEN LIKELY FOR MOST OF THE NIGHT. A
RAIN/SNOW MIX WILL SPREAD OVER THE TERMINALS THIS EVENING BUT
EXPECT A RAPID CHANGE OVER TO ALL SNOW BASICALLY WITHIN AN HOUR OF
ONSET. NO REAL CHANGES TO EXPECTED SNOW TONIGHT AND TIMING WITH
THE 6-10Z TIME FRAME STILL THE BEST TIME FOR MORE MODERATE TO
HEAVY SNOW. HAVE LEFT THE LOWEST VIS AT 1/2 MILE FOR ALL THE
TERMINAL SITES...BUT WITH THEM LIKELY OBSERVING PERIODS OF 1/4
MILE OR EVEN LESS AT TIMES. EXPECT THIS HEAVIER SNOW TO BE MORE
TIED TO CONVECTIVE ASPECTS...WITH UNCERTAINTY TO EXACT TIMING AND
DURATION OF THIS HEAVIER SNOW ASSOCIATED WITH THIS FEATURE.
MDW/GYY WOULD LIKELY HAVE THE BEST CHANCES FOR 1/4 MILE OR LESS
VISIBILITY AS WELL AS FOR A LONGER DURATION AS THIS WILL BE A MORE
FAVORED LOCATION FOR THE BEST SNOWFALL DEVELOPMENT. BUT ONCE
AGAIN...WITH SOME UNCERTAINTY REMAINING...HAVE OPTED TO LEAVE OUT
OF THE TAF AT THIS TIME BUT COULD SEE THIS LOWER VIS IN HEAVY SNOW
ADDED LATER THIS EVENING. BEST SNOW DEVELOPMENT SHOULD EXIT THE
TERMINALS BY EARLY WEDNESDAY MORNING...TAPERING OFF THROUGH THE
MORNING WITH A SLOW IMPROVING TREND WITH CEILINGS.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED/DIRECTION...AND RESULTANT
BLOWING SNOW.
* MEDIUM HIGH CONFIDENCE WITH RAIN/SNOW MIX TIMING AND CHANGE OVER
TO SNOW.
* MEDIUM CONFIDENCE WITH VIS/CEILING TRENDS.
* MEDIUM HIGH CONFIDENCE WITH HEAVY SNOW...LOW MEDIUM CONFIDENCE
WITH TIMING/DURATION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT...DRY/VFR.
* THURSDAY...DRY/VFR. GUSTY SOUTHWEST WINDS.
* FRIDAY...DRY/VFR. GUSTY WESTERLY WINDS.
* SATURDAY...DRY/VFR.
* SUNDAY...SLIGHT CHANCE OF SNOW.
* MONDAY...DRY/VFR.
&&
.MARINE...
210 PM CDT
LOW PRESSURE OVER THE CENTRAL PLAINS WILL CONTINUE TO DEEPEN AS IT
TRACKS EAST ACROSS SOUTHERN ILLINOIS TONIGHT AND INTO THE OHIO
VALLEY WEDNESDAY. AS THE LOW TRACKS SOUTH AND THEN SOUTHEAST OF THE
LAKE...HIGH PRESSURE WILL ALSO BUILD ACROSS THE UPPER GREAT LAKES
REGION...SETTING UP STRONG NORTH WINDS. THE COMBINATION OF A STRONG
GRADIENT AND STRONG COLD ADVECTION WILL LEAD TO WINDS QUICKLY
INCREASING TO GALES BY LATE THIS EVENING. THE LATEST GUIDANCE HAS
BEEN RELATIVELY CONSISTENT IN INDICATING THE POTENTIAL FOR HIGH END
GALES BY LATE WEDNESDAY MORNING AND EARLY AFTERNOON...WITH THE
STRONGEST GALES OVER THE SOUTHERN PORTIONS OF THE LAKE...INCLUDING
THE NEARSHORE WATERS. BY WEDNESDAY EVENING...THE HIGH PRESSURE WILL
BEGIN TO SPREAD ACROSS LAKE MICHIGAN ALLOWING WINDS TO SUBSIDE BELOW
GALE FORCE. BY THURSDAY NIGHT...THE HIGH WILL PUSH TO THE SOUTHEAST
OF THE LAKE AS A CLIPPER DROPS OUT OF NORTHERN ALBERTA AND SWINGS
JUST NORTH OF THE UPPER GREAT LAKES ON FRIDAY. WITH THE SFC HIGH
SAGGING OFF THE SERN COAST...A PERIOD OF SWLY WINDS WILL DEVELOP
AHEAD OF AN APPROACHING COLD FRONT TRAILING FROM THE CLIPPER.
ANTICIPATE A PERIOD OF BRISK SLY TO SWLY WINDS FOR THURSDAY NIGHT
THROUGH FRIDAY...BUT MORE GALES ARE NOT EXPECTED AT THIS TIME. AS
THE CLIPPER TURNS NEWD INTO QUEBEC...IT WILL DRAG A WEAK COLD FRONT
DOWN THE LAKE WITH ANOTHER ARCTIC HIGH BUILDING IN BEHIND THE
FRONT. 25-30KT NORTH WINDS WILL SET UP FOLLOWING THE FROPA FOR
SATURDAY NIGHT AND SUNDAY...BUT AS THE HIGH SPREADS ACROSS THE GREAT
LAKES SUNDAY NIGHT...WINDS SHOULD BECOME MORE LIGHT AND VARIABLE.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032...10 PM TUESDAY TO 1 PM WEDNESDAY.
WINTER WEATHER ADVISORY...ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012...10 PM TUESDAY TO 10 AM WEDNESDAY.
WINTER STORM WATCH...ILZ033-ILZ039...1 AM WEDNESDAY TO 1 PM
WEDNESDAY.
IN...WINTER STORM WARNING...INZ001-INZ002...10 PM TUESDAY TO 1 PM
WEDNESDAY.
WINTER STORM WATCH...INZ010-INZ011-INZ019...1 AM WEDNESDAY TO 1
PM WEDNESDAY.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...MIDNIGHT WEDNESDAY TO 9 PM WEDNESDAY.
GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...3 AM WEDNESDAY TO 4 PM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
125 PM CDT TUE MAR 11 2014
.DISCUSSION...
1234 PM CDT
WINTER STORM UPDATE...
CONTINUING TO ASSESS 12Z MODEL DATA FOR IMPENDING WINTER STORM.
SURFACE OBSERVATION ANALYSIS SHOWS 996 MB LOW IN CENTRAL KS
ROUGHLY BETWEEN SLN AND HUT...NORTH OF LATEST RUN OF RAP MODEL.
TRENDS SO FAR SUPPORT THE AXIS OF HEAVIEST SNOW IN GOING FORECAST
AND HAVENT MADE ANY CHANGES TO THIS YET...WITH ONLY TWEAKS TO LATE
AFTERNOON POPS AS BAROCLINIC ZONE STARTS TO SHIFT SOUTH AND RAIN
COMMENCES IN FAR NORTHERN CWA. RAIN SHOULD QUICKLY FLIP OVER TO
SNOW THIS EVENING IN NORTHERN ILLINOIS AS COLDER AIR FILTERS IN
FROM THE NORTH.
OF BIGGEST CONCERN WITH THE SNOW LATE TONIGHT IS THE BAND OF VERY
STRONG 850-700 MB FGEN OVERLAID BY NEGATIVE EPV...AS WELL AS THE
PRESENCE OF 50-100 J/KG OF MUCAPE. THIS HIGHLIGHTS POTENTIAL FOR
CONVECTIVE SNOW BANDS AND RATES OF 2 INCHES PLUS PER HOUR
WHEREVER THIS SETS UP. KEEPING TOTALS IN CHECK WILL BE
PROGRESSIVE NATURE OF SYSTEM WITH MIDLEVEL TROUGH REMAINING
OPEN...SO WOULD ONLY EXPECT A FEW HOUR PERIOD WITH THE REALLY
HEAVY RATES IN ANY GIVEN AREA. NONETHELESS...COULD SEE SOME
ISOLATED TOTALS TO OR EVEN A BIT ABOVE 8 INCHES IN WARNING
AREA...WITH THIS MOST LIKELY TO OCCUR ROUGHLY ALONG AND A BIT EAST
OF I-55 CORRIDOR.
LIKELY BECAUSE OF BANDING POTENTIAL...HIGHER RES GUIDANCE SHOWING
A VERY SHARP CUTOFF TO PRECIP IN NORTHERN CWA...AND THINK THIS IS
OVERDONE...BUT THERE WILL BE A GRADIENT IN SNOW AMOUNTS ROUGHLY IN
LINE WITH GOING FORECAST. FARTHER SOUTH IN WATCH
AREA...UNCERTAINTY REMAINS OVER HOW FAST CHANGEOVER WILL OCCUR AND
HOW MUCH PRECIP WILL FALL AFTER CHANGEOVER...SO WILL MAKE A
DECISION ON HEADLINE FOR SOUTHEAST CWA WITH AFTERNOON ISSUANCE.
FINALLY...WINDS REMAIN A SIGNIFICANT CONCERN AS WELL LATE TONIGHT
INTO WEDNESDAY MORNING...WITH SOUNDINGS SUPPORTING NORTHERLY WIND
GUSTS TO 40+ MPH. THIS WILL EXACERBATE IMPACTS TO WEDS AM COMMUTE
EVEN AS SNOW WINDS DOWN.
RC/JEE
//PREV DISCUSSION...
343 AM CDT
THE TASTE OF SPRING YESTERDAY IS TRULY IN THE REAR VIEW MIRROR AS
THE FORECAST FOCUS WAS ON WINTER STORM SET TO IMPACT THE AREA
TONIGHT INTO EARLY WEDNESDAY. HAVE ISSUED A WINTER STORM WARNING
CENTERED ON THE I-80 CORRIDOR...AND THAT INCLUDES CHICAGO...FOR THE
COMBINATION OF HEAVY SNOWFALL RATES OF UP TO 2 INCHES PER
HOUR...SNOW TOTALS AROUND SIX INCHES...AND WIND WHIPPED SNOW
GREATLY REDUCING VISIBILITY. CONTINUE THE WATCH SOUTH OF THERE AND
AN ADVISORY TO THE NORTH.
THE PRIMARY UPPER LOW IS WELL-DEFINED THIS MORNING ACROSS WYOMING
AND ADVANCING SOUTHEAST WITH OVER 200M HEIGHT FALLS AT 300MB SAMPLED
LAST EVE. SECOND KEY SHORT WAVE IS DROPPING SOUTHWARD FROM MANITOBA.
THE PHASING OF THESE SYSTEMS IS ANTICIPATED TO OCCUR ACROSS THE
WESTERN GREAT LAKES OVERNIGHT INTO WEDNESDAY MORNING. AS OFTEN SEEN
WITH PHASING SYSTEMS...FORCING FOR LIFT AND HEAVY PRECIP IS EXPECTED
TO RAPIDLY INCREASE TONIGHT. NUMERICAL GUIDANCE HAS HAD SOME
PRONOUNCED DIFFERENCES AND THAT CONTINUED INTO THE 11.00Z AND
11.06Z CYCLES...BUT IT IS IMPORTANT TO NOTE THAT ALL GUIDANCE
DEPICT ALL THE INGREDIENTS FOR HEAVY SNOWFALL AND THAT ARE
CONSISTENT WITH A PHASING SYSTEM. HAVE PREFERRED THE GLOBAL GUIDANCE
SOLUTION OF MASS FIELDS AND TAKEN INTO ACCOUNT THE MRF AND LOCAL
HIGH RES MODELS IDEAS OF MESOSCALE VERY HEAVY SNOWFALL RATES AND
TIMING. BELIEVE THE MRF IS A LITTLE TOO ROBUST AND WIDESPREAD
WITH ITS HEAVIEST QPF...BUT AGAIN THE IDEA OF HEAVY SNOWFALL WITH
AMOUNTS EXCEEDING SIX INCHES IN AN AREA IS SUPPORTED.
TODAY...
THIS STILL LOOKS MAINLY DRY ACROSS THE FORECAST AREA WITH A VERY
SHARP MID-LEVEL STATIONARY FRONT SAMPLED ON LAST EVES RAOBS BECOMING
MORE ACTIVE AHEAD OF THE APPROACHING TROUGHS. EARLY MORNING RADAR
MOSAIC INDICATES PRECIP FROM SD THROUGH WESTERN WI. THIS SHOULD ONLY
INCH SOUTHWARD GRADUALLY TODAY. FRONTOGENESIS RESPONSE FROM EVEN THE
MOST SOUTH HIGH RESOLUTION GUIDANCE WOULD KEEP RAIN NORTH OF THE
AREA THROUGH MID-AFTERNOON. STILL SHOULD SEE PLENTY OF CLOUD
COVER AND WITH NORTHEAST WINDS INCREASING AHEAD OF CYCLOGENESIS IN
THE PLAINS...EXPECT THAT SURFACE TEMPERATURES WILL START TO LEVEL
OUT AROUND THE NOON HOUR AND THEN BEGIN TO GRADUALLY FALL. ONSHORE
FLOW INTO CHICAGO OFF THE ICE-COVERED LAKE MAY LEAD TO A MORE RAPID
FALL DOWNTOWN.
TONIGHT AND WEDNESDAY MORNING...
IN RESPONSE TO THE AFOREMENTIONED PHASING...MAXIMUM HEIGHT FALLS ARE
CENTERED DIRECTLY ON THE AREA TONIGHT WITH LIFT RAPIDLY INCREASING.
THIS WILL EVOLVE THE LOW-LEVEL FEATURES EASTWARD WITH COPIOUS
MOISTURE TRANSPORTED NORTH OF A 40-45 KT LOW-LEVEL JET. PRECIP FROM
THE NORTH IS EXPECTED TO QUICKLY MOVE SOUTH...WHILE NEW PRECIP
SHOULD DEVELOP JUST WEST OR OVER THE AREA THIS EVE. THE DEGREE OF
FORCING AND COOL ADVECTION IN THE NORTHEAST QUADRANT OF THE SYSTEM
WILL HELP TO COOL THE COLUMN FROM NORTH TO SOUTH FOR A TRANSITION OF
RAIN TO SNOW...AND THIS WILL BE ESPECIALLY TRUE DURING THE MID EVE
INTO EARLY OVERNIGHT AS THE MOST ROBUST FORCING MOVES IN. WOULD
EXPECT SOME AREAS OF NORTHERN ILLINOIS MAY JUST BEGIN AS SNOW OR
EXPERIENCE A VERY SHORT MIX. AS FOR AREAS ALONG AND SOUTH OF
I-80...A COUPLE/SEVERAL HOUR WINDOW OF RAIN WILL BE LIKELY FIRST
BEFORE TRANSITIONING TO A WET SNOW LATE THIS EVE INTO EARLY
OVERNIGHT. THAT TIME PERIOD AFTER TRANSITION AND INTO OVERNIGHT IS
MOST FAVORED FOR HEAVY SNOWFALL...WITH UPRIGHT INSTABILITY FORECAST
BY GLOBAL MODELS TO REACH INTO THE CENTRAL FORECAST AREA...WHICH
LINES UP WITH THE DEEPEST CONVERGENCE AND FOCUS NEAR I-80. THE
11.03Z SREF PROBABILITIES OF OVER ONE INCH PER HOUR SNOWFALL RATES
ARE TO 70 PERCENT WHICH IS IMPRESSIVE AND MAKE SENSE...AND WOULD NOT
BE SURPRISED TO SEE TEMPORARY TWO INCH PER HOUR OR HIGHER RATES LATE
THIS EVE INTO OVERNIGHT. THE WINDS LOOK TO REALLY RAMP UP OVERNIGHT
AROUND THE DEEPENING LOW...WITH 45 KT OF NORTHEAST FLOW ON THE NAM
AND GFS AT 1000-2000 FT. EVEN WITH THE WET SNOW...EXPECT THAT THE
BLOWING OF THE FALLING SNOW WILL CAUSE EVEN FURTHER REDUCED
VISIBILITY...AND EVEN TEMPORARY WHITE OUT CONDITIONS IN THE HEAVIEST
OF SNOWFALL RATES.
BY WEDNESDAY MORNING SNOW SHOULD BE ENDING FROM WEST TO
EAST...ALTHOUGH SOME PRETTY SOLID RATES COULD STILL BE OCCURRING IN
EASTERN AREAS...INCLUDING POSSIBLY CHICAGO INTO THE EARLY PARTS OF
THE MORNING COMMUTE. UNCERTAINTY ON END TIME OF SNOWFALL IS FAIRLY
HIGH...BUT THE WINDS SHOULD CONTINUE AND SO EXPECT IMPACTS...AND
THAT MAY BE ESPECIALLY TRUE NEAR THE LAKE SHORE WHERE THE WIND COULD
GUST TO 40-45 MPH. THAT IS WHY RUN HEADLINES THROUGH NOON.
WITH THE HIGH MOISTURE...AS DEPICTED BY MIXING RATIOS OF 4-6 G/KG
AND PWATS OF AROUND 0.75 IN...THERE SHOULD NOT BE TOO MUCH OF A
PROBLEM WITH SNOWFALL AMOUNTS IN THE MAXIMUM AREA TOPPING SIX
INCHES...EVEN WITH THE QUICK MOVEMENT OF THE SYSTEM AND LOW
SNOW-TO-LIQUID RATIOS. THE HIGHEST AMOUNTS COULD EXCEED 8 INCHES IN
ISOLATED AREAS...BUT AGAIN LIMITED DURATION SHOULD PREVENT THAT FROM
BEING TOO WIDESPREAD.
HEADLINES...
GIVEN RATES AND BLOWING OF THE FALLING SNOW...WITH BASICALLY A
DOWNPOUR OF SNOW WITH CONCURRENT GUSTS OF 30+ MPH...HAVE OPTED TO GO
WITH A WARNING FOR THE AREA WITH THE LONGEST DURATION OF SNOW....EVEN
THOUGH NOT EVERYWHERE WILL SEE SIX PLUS INCHES OF SNOW.
UNCERTAINTY OF SNOW DURATION IN THE FAR SOUTH LED TO CONTINUING
THE WATCH. FURTHER NORTH HAVE AN ADVISORY...AND DID NOT INCLUDE
ROCKFORD BECAUSE IT LOOKS LIKE SNOWFALL SHOULD HAVE ENDED BY MUCH
OF IF NOT THE ENTIRE WED MORNING COMMUTE. IT IS CERTAINLY POSSIBLE
ADJUSTMENTS TO THE NORTHERN END OF HEADLINES ARE MADE TODAY.
WEDNESDAY NIGHT AND THURSDAY...
NOT MUCH CHANGE MADE TO THIS PERIOD. WEDNESDAY NIGHT LOOKS TO BE
PRETTY CHILLY WITH THE FRESH SNOW COVER AND DIMINISHING WINDS...AND
IF THE SKY CAN REMAIN CLEAR THE LOWS MAY BE WITHIN FIVE DEGREES OF
RECORD LOWS FOR MARCH 13TH.
MTF
EXTENDED PERIOD...FRIDAY THROUGH MONDAY...
AN AMPLIFIED LARGE SCALE UPPER LEVEL WEATHER PATTERN WILL REMAIN THE
MAIN STORY DURING THE EXTENDED PERIOD. THIS WILL LIKELY FEATURE
POSITIVE HEIGHT ANOMALIES ACROSS THE EASTERN PACIFIC AND THE PACIFIC
COAST OF THE CONUS...AND BELOW AVERAGE HEIGHTS ACROSS THE EASTERN
CONUS. ULTIMATELY THIS WILL RESULT IN BELOW AVERAGE TEMPERATURES
DURING MUCH OF THE EXTEND PERIOD.
IT APPEARS FRIDAY WILL BE THE WARMEST DAY OF THE EXTENDED. A CLIPPER
TYPE SYSTEM IS EXPECTED TO TRACK EASTWARD ACROSS THE UPPER GREAT
LAKES REGION ON FRIDAY...AND THIS SHOULD RESULT IN BREEZE...BUT
MILD...SOUTHWESTERLY FLOW ACROSS THE REGION. IT APPEARS TEMPERATURES
COULD WARM INTO THE 50S...BUT ANY REMAINING SNOW COVER FROM THE
SNOWFALL TONIGHT MAY HINDER THE MAGNITUDE OF WARMING SOME.
THIS WARM AIR WILL BE SHORT LIVED AS COLDER AIR WILL LIKELY BEGIN TO
SPILL BACK SOUTHWARD ACROSS THE AREA BY SATURDAY AS A COLD FRONT
DROPS ACROSS THE AREA. SOME LIGHT SNOW SHOWERS MAY ACCOMPANY THIS
COLDER AIR PUSH FRIDAY NIGHT. GUIDANCE IS HINTING AT DECENT SHORT
WAVE TROUGH DIGGING SOUTHEASTWARD ACROSS SOUTHERN WISCONSIN DURING
THIS TIME. IN SPITE OF THIS...I HAVE CHOSEN TO LEAVE THE FORECAST
DRY AT THIS TIME.
A VERY ACTIVE JET ACROSS THE PACIFIC WILL LIKELY CONTINUE TO DRIVE
DISTURBANCES EASTWARD ATOP A BUILDING WESTERN CONUS RIDGE INTO NEXT
WEEK. ALTHOUGH THE ACTUAL TIMING AND EVOLUTION OF THESE
DISTURBANCES IS HIGHLY UNCERTAIN AT THIS JUNCTURE...IT DOES APPEAR
THAT A NORTHWESTERLY UPPER LEVEL PATTERN ACROSS THE CENTRAL CONUS
COULD PRODUCE SOME ADDITIONAL CHANCES OF SNOW FOR PORTIONS OF THE
REGION LATER IN THE WEEKEND...DEPENDING ON THE ACTUALLY TRACK. WITH
THIS IN MIND...I HAVE LEFT SOME LOW END POPS IN FOR LATER IN THE
WEEKEND.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* NORTHEAST WINDS INCREASING TODAY AND TONIGHT WITH GUSTS OF
30-35 KT LIKELY TONIGHT INTO WEDNESDAY MORNING.
* RAIN/SNOW MIX BY MID EVENING...RAPIDLY CHANGING OVER TO ALL SNOW
SOON THERE AFTER.
* RAPIDLY DETERIORATING CONDITIONS IN SNOW WITH VIS/CEILINGS
FALLING TO LIFR/VLIFR.
* PERIOD OF HEAVY SNOW WITH SIGNIFICANTLY REDUCED VIS LIKELY AFTER
MIDNIGHT.
* BLOWING SNOW OVERNIGHT INTO WEDNESDAY MORNING.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
VFR CONDITIONS AND AN INCREASING NORTHEAST WIND IN PLACE OVER THE
TERMINALS EARLY THIS AFTERNOON AS APPROACHING LOW TO THE SOUTHWEST
CONTINUES TO WORK ITS WAY TOWARDS THE AREA. WINDS WILL STEADILY
INCREASE THROUGH THE AFTERNOON AND EVENING WITH HIGHEST GUSTS
EXPECTED OVERNIGHT INTO WEDNESDAY MORNING. VFR CEILINGS WILL LOWER
THIS AFTERNOON BUT THEN QUICKLY DETERIORATE AS BETTER FORCING
ARRIVES THIS EVENING WITH MVFR CONDITIONS BECOMING IFR SOON THERE
AFTER...WITH THESE CEILINGS THEN LIKELY FOR MOST OF THE NIGHT. A
RAIN/SNOW MIX WILL SPREAD OVER THE TERMINALS THIS EVENING BUT
EXPECT A RAPID CHANGE OVER TO ALL SNOW BASICALLY WITHIN AN HOUR OF
ONSET. NO REAL CHANGES TO EXPECTED SNOW TONIGHT AND TIMING WITH
THE 6-10Z TIME FRAME STILL THE BEST TIME FOR MORE MODERATE TO
HEAVY SNOW. HAVE LEFT THE LOWEST VIS AT 1/2 MILE FOR ALL THE
TERMINAL SITES...BUT WITH THEM LIKELY OBSERVING PERIODS OF 1/4
MILE OR EVEN LESS AT TIMES. EXPECT THIS HEAVIER SNOW TO BE MORE
TIED TO CONVECTIVE ASPECTS...WITH UNCERTAINTY TO EXACT TIMING AND
DURATION OF THIS HEAVIER SNOW ASSOCIATED WITH THIS FEATURE.
MDW/GYY WOULD LIKELY HAVE THE BEST CHANCES FOR 1/4 MILE OR LESS
VISIBILITY AS WELL AS FOR A LONGER DURATION AS THIS WILL BE A MORE
FAVORED LOCATION FOR THE BEST SNOWFALL DEVELOPMENT. BUT ONCE
AGAIN...WITH SOME UNCERTAINTY REMAINING...HAVE OPTED TO LEAVE OUT
OF THE TAF AT THIS TIME BUT COULD SEE THIS LOWER VIS IN HEAVY SNOW
ADDED LATER THIS EVENING. BEST SNOW DEVELOPMENT SHOULD EXIT THE
TERMINALS BY EARLY WEDNESDAY MORNING...TAPERING OFF THROUGH THE
MORNING WITH A SLOW IMPROVING TREND WITH CEILINGS.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED/DIRECTION...AND RESULTANT
BLOWING SNOW.
* MEDIUM HIGH CONFIDENCE WITH RAIN/SNOW MIX TIMING AND CHANGE OVER
TO SNOW.
* MEDIUM CONFIDENCE WITH VIS/CEILING TRENDS.
* MEDIUM HIGH CONFIDENCE WITH HEAVY SNOW...LOW MEDIUM CONFIDENCE
WITH TIMING/DURATION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT...DRY/VFR.
* THURSDAY...DRY/VFR. GUSTY SOUTHWEST WINDS.
* FRIDAY...DRY/VFR. GUSTY WESTERLY WINDS.
* SATURDAY...DRY/VFR.
* SUNDAY...SLIGHT CHANCE OF SNOW.
* MONDAY...DRY/VFR.
&&
.MARINE...
330 AM...LOW PRESSURE CURRENTLY OVER THE WESTERN PLAINS WILL MOVE
EAST TO SOUTHERN ILLINOIS LATE THIS EVENING AND THEN DEEPEN AS IT
REACHES NEW ENGLAND WEDNESDAY NIGHT. THE GRADIENT WILL TIGHTEN AS
THIS LOW PASSES SOUTH OF LAKE MICHIGAN WITH NORTHERLY WINDS STEADILY
INCREASING FROM THIS AFTERNOON INTO EARLY WEDNESDAY MORNING. GALES
APPEAR TO BEGIN LATE THIS EVENING AND INCREASE TO 45 KTS OVERNIGHT
AND CONTINUE THROUGH MIDDAY WEDNESDAY...SLOWLY DIMINISHING WEDNESDAY
AFTERNOON INTO WEDNESDAY EVENING. OTHER THAN TWEAKING WIND SPEEDS/
GUSTS UP...NO SIGNIFICANT CHANGES TO GOING FORECAST/GRIDS OR
HEADLINES. WINDS WILL QUICKLY DIMINISH WEDNESDAY NIGHT/EARLY
THURSDAY MORNING AS A RIDGE OF HIGH PRESSURE MOVES ACROSS THE LAKE.
WINDS THEN TURN SOUTHWESTERLY AND INCREASE TO 30 KTS AS LOW PRESSURE
MOVES ACROSS ONTARIO THURSDAY NIGHT AND FRIDAY...WITH A TRAILING
COLD FRONT FROM THIS LOW MOVING ACROSS THE WESTERN LAKES FRIDAY
AFTERNOON INTO FRIDAY EVENING.
VISIBLE SATELLITE IMAGERY FROM MONDAY SHOWS SOME OPEN WATER IN THE
ILLINOIS NEARSHORE ZONES AND HAVE ACCOUNTED FOR THIS WITH WAVE
HEIGHTS IN THIS MORNING/S FORECAST. HOWEVER...WITH THE EXPECTED
STRONG NORTHERLY WINDS...ICE IN THE OPEN WATERS IS EXPECTED TO BE
PUSHED BACK TO THE ILLINOIS SHORE TONIGHT. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032...10 PM TUESDAY TO 1 PM WEDNESDAY.
WINTER WEATHER ADVISORY...ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012...10 PM TUESDAY TO 10 AM WEDNESDAY.
WINTER STORM WATCH...ILZ033-ILZ039...1 AM WEDNESDAY TO 1 PM
WEDNESDAY.
IN...WINTER STORM WARNING...INZ001-INZ002...10 PM TUESDAY TO 1 PM
WEDNESDAY.
WINTER STORM WATCH...INZ010-INZ011-INZ019...1 AM WEDNESDAY TO 1
PM WEDNESDAY.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...MIDNIGHT WEDNESDAY TO 9 PM WEDNESDAY.
GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...3 AM WEDNESDAY TO 4 PM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1234 PM CDT TUE MAR 11 2014
.DISCUSSION...
1234 PM CDT
WINTER STORM UPDATE...
CONTINUING TO ASSESS 12Z MODEL DATA FOR IMPENDING WINTER STORM.
SURFACE OBSERVATION ANALYSIS SHOWS 996 MB LOW IN CENTRAL KS
ROUGHLY BETWEEN SLN AND HUT...NORTH OF LATEST RUN OF RAP MODEL.
TRENDS SO FAR SUPPORT THE AXIS OF HEAVIEST SNOW IN GOING FORECAST
AND HAVENT MADE ANY CHANGES TO THIS YET...WITH ONLY TWEAKS TO LATE
AFTERNOON POPS AS BAROCLINIC ZONE STARTS TO SHIFT SOUTH AND RAIN
COMMENCES IN FAR NORTHERN CWA. RAIN SHOULD QUICKLY FLIP OVER TO
SNOW THIS EVENING IN NORTHERN ILLINOIS AS COLDER AIR FILTERS IN
FROM THE NORTH.
OF BIGGEST CONCERN WITH THE SNOW LATE TONIGHT IS THE BAND OF VERY
STRONG 850-700 MB FGEN OVERLAID BY NEGATIVE EPV...AS WELL AS THE
PRESENCE OF 50-100 J/KG OF MUCAPE. THIS HIGHLIGHTS POTENTIAL FOR
CONVECTIVE SNOW BANDS AND RATES OF 2 INCHES PLUS PER HOUR
WHEREVER THIS SETS UP. KEEPING TOTALS IN CHECK WILL BE
PROGRESSIVE NATURE OF SYSTEM WITH MIDLEVEL TROUGH REMAINING
OPEN...SO WOULD ONLY EXPECT A FEW HOUR PERIOD WITH THE REALLY
HEAVY RATES IN ANY GIVEN AREA. NONETHELESS...COULD SEE SOME
ISOLATED TOTALS TO OR EVEN A BIT ABOVE 8 INCHES IN WARNING
AREA...WITH THIS MOST LIKELY TO OCCUR ROUGHLY ALONG AND A BIT EAST
OF I-55 CORRIDOR.
LIKELY BECAUSE OF BANDING POTENTIAL...HIGHER RES GUIDANCE SHOWING
A VERY SHARP CUTOFF TO PRECIP IN NORTHERN CWA...AND THINK THIS IS
OVERDONE...BUT THERE WILL BE A GRADIENT IN SNOW AMOUNTS ROUGHLY IN
LINE WITH GOING FORECAST. FARTHER SOUTH IN WATCH
AREA...UNCERTAINTY REMAINS OVER HOW FAST CHANGEOVER WILL OCCUR AND
HOW MUCH PRECIP WILL FALL AFTER CHANGEOVER...SO WILL MAKE A
DECISION ON HEADLINE FOR SOUTHEAST CWA WITH AFTERNOON ISSUANCE.
FINALLY...WINDS REMAIN A SIGNIFICANT CONCERN AS WELL LATE TONIGHT
INTO WEDNESDAY MORNING...WITH SOUNDINGS SUPPORTING NORTHERLY WIND
GUSTS TO 40+ MPH. THIS WILL EXACERBATE IMPACTS TO WEDS AM COMMUTE
EVEN AS SNOW WINDS DOWN.
RC/JEE
&&
.PREV DISCUSSION...
343 AM CDT
THE TASTE OF SPRING YESTERDAY IS TRULY IN THE REAR VIEW MIRROR AS
THE FORECAST FOCUS WAS ON WINTER STORM SET TO IMPACT THE AREA
TONIGHT INTO EARLY WEDNESDAY. HAVE ISSUED A WINTER STORM WARNING
CENTERED ON THE I-80 CORRIDOR...AND THAT INCLUDES CHICAGO...FOR THE
COMBINATION OF HEAVY SNOWFALL RATES OF UP TO 2 INCHES PER
HOUR...SNOW TOTALS AROUND SIX INCHES...AND WIND WHIPPED SNOW
GREATLY REDUCING VISIBILITY. CONTINUE THE WATCH SOUTH OF THERE AND
AN ADVISORY TO THE NORTH.
THE PRIMARY UPPER LOW IS WELL-DEFINED THIS MORNING ACROSS WYOMING
AND ADVANCING SOUTHEAST WITH OVER 200M HEIGHT FALLS AT 300MB SAMPLED
LAST EVE. SECOND KEY SHORT WAVE IS DROPPING SOUTHWARD FROM MANITOBA.
THE PHASING OF THESE SYSTEMS IS ANTICIPATED TO OCCUR ACROSS THE
WESTERN GREAT LAKES OVERNIGHT INTO WEDNESDAY MORNING. AS OFTEN SEEN
WITH PHASING SYSTEMS...FORCING FOR LIFT AND HEAVY PRECIP IS EXPECTED
TO RAPIDLY INCREASE TONIGHT. NUMERICAL GUIDANCE HAS HAD SOME
PRONOUNCED DIFFERENCES AND THAT CONTINUED INTO THE 11.00Z AND
11.06Z CYCLES...BUT IT IS IMPORTANT TO NOTE THAT ALL GUIDANCE
DEPICT ALL THE INGREDIENTS FOR HEAVY SNOWFALL AND THAT ARE
CONSISTENT WITH A PHASING SYSTEM. HAVE PREFERRED THE GLOBAL GUIDANCE
SOLUTION OF MASS FIELDS AND TAKEN INTO ACCOUNT THE MRF AND LOCAL
HIGH RES MODELS IDEAS OF MESOSCALE VERY HEAVY SNOWFALL RATES AND
TIMING. BELIEVE THE MRF IS A LITTLE TOO ROBUST AND WIDESPREAD
WITH ITS HEAVIEST QPF...BUT AGAIN THE IDEA OF HEAVY SNOWFALL WITH
AMOUNTS EXCEEDING SIX INCHES IN AN AREA IS SUPPORTED.
TODAY...
THIS STILL LOOKS MAINLY DRY ACROSS THE FORECAST AREA WITH A VERY
SHARP MID-LEVEL STATIONARY FRONT SAMPLED ON LAST EVES RAOBS BECOMING
MORE ACTIVE AHEAD OF THE APPROACHING TROUGHS. EARLY MORNING RADAR
MOSAIC INDICATES PRECIP FROM SD THROUGH WESTERN WI. THIS SHOULD ONLY
INCH SOUTHWARD GRADUALLY TODAY. FRONTOGENESIS RESPONSE FROM EVEN THE
MOST SOUTH HIGH RESOLUTION GUIDANCE WOULD KEEP RAIN NORTH OF THE
AREA THROUGH MID-AFTERNOON. STILL SHOULD SEE PLENTY OF CLOUD
COVER AND WITH NORTHEAST WINDS INCREASING AHEAD OF CYCLOGENESIS IN
THE PLAINS...EXPECT THAT SURFACE TEMPERATURES WILL START TO LEVEL
OUT AROUND THE NOON HOUR AND THEN BEGIN TO GRADUALLY FALL. ONSHORE
FLOW INTO CHICAGO OFF THE ICE-COVERED LAKE MAY LEAD TO A MORE RAPID
FALL DOWNTOWN.
TONIGHT AND WEDNESDAY MORNING...
IN RESPONSE TO THE AFOREMENTIONED PHASING...MAXIMUM HEIGHT FALLS ARE
CENTERED DIRECTLY ON THE AREA TONIGHT WITH LIFT RAPIDLY INCREASING.
THIS WILL EVOLVE THE LOW-LEVEL FEATURES EASTWARD WITH COPIOUS
MOISTURE TRANSPORTED NORTH OF A 40-45 KT LOW-LEVEL JET. PRECIP FROM
THE NORTH IS EXPECTED TO QUICKLY MOVE SOUTH...WHILE NEW PRECIP
SHOULD DEVELOP JUST WEST OR OVER THE AREA THIS EVE. THE DEGREE OF
FORCING AND COOL ADVECTION IN THE NORTHEAST QUADRANT OF THE SYSTEM
WILL HELP TO COOL THE COLUMN FROM NORTH TO SOUTH FOR A TRANSITION OF
RAIN TO SNOW...AND THIS WILL BE ESPECIALLY TRUE DURING THE MID EVE
INTO EARLY OVERNIGHT AS THE MOST ROBUST FORCING MOVES IN. WOULD
EXPECT SOME AREAS OF NORTHERN ILLINOIS MAY JUST BEGIN AS SNOW OR
EXPERIENCE A VERY SHORT MIX. AS FOR AREAS ALONG AND SOUTH OF
I-80...A COUPLE/SEVERAL HOUR WINDOW OF RAIN WILL BE LIKELY FIRST
BEFORE TRANSITIONING TO A WET SNOW LATE THIS EVE INTO EARLY
OVERNIGHT. THAT TIME PERIOD AFTER TRANSITION AND INTO OVERNIGHT IS
MOST FAVORED FOR HEAVY SNOWFALL...WITH UPRIGHT INSTABILITY FORECAST
BY GLOBAL MODELS TO REACH INTO THE CENTRAL FORECAST AREA...WHICH
LINES UP WITH THE DEEPEST CONVERGENCE AND FOCUS NEAR I-80. THE
11.03Z SREF PROBABILITIES OF OVER ONE INCH PER HOUR SNOWFALL RATES
ARE TO 70 PERCENT WHICH IS IMPRESSIVE AND MAKE SENSE...AND WOULD NOT
BE SURPRISED TO SEE TEMPORARY TWO INCH PER HOUR OR HIGHER RATES LATE
THIS EVE INTO OVERNIGHT. THE WINDS LOOK TO REALLY RAMP UP OVERNIGHT
AROUND THE DEEPENING LOW...WITH 45 KT OF NORTHEAST FLOW ON THE NAM
AND GFS AT 1000-2000 FT. EVEN WITH THE WET SNOW...EXPECT THAT THE
BLOWING OF THE FALLING SNOW WILL CAUSE EVEN FURTHER REDUCED
VISIBILITY...AND EVEN TEMPORARY WHITE OUT CONDITIONS IN THE HEAVIEST
OF SNOWFALL RATES.
BY WEDNESDAY MORNING SNOW SHOULD BE ENDING FROM WEST TO
EAST...ALTHOUGH SOME PRETTY SOLID RATES COULD STILL BE OCCURRING IN
EASTERN AREAS...INCLUDING POSSIBLY CHICAGO INTO THE EARLY PARTS OF
THE MORNING COMMUTE. UNCERTAINTY ON END TIME OF SNOWFALL IS FAIRLY
HIGH...BUT THE WINDS SHOULD CONTINUE AND SO EXPECT IMPACTS...AND
THAT MAY BE ESPECIALLY TRUE NEAR THE LAKE SHORE WHERE THE WIND COULD
GUST TO 40-45 MPH. THAT IS WHY RUN HEADLINES THROUGH NOON.
WITH THE HIGH MOISTURE...AS DEPICTED BY MIXING RATIOS OF 4-6 G/KG
AND PWATS OF AROUND 0.75 IN...THERE SHOULD NOT BE TOO MUCH OF A
PROBLEM WITH SNOWFALL AMOUNTS IN THE MAXIMUM AREA TOPPING SIX
INCHES...EVEN WITH THE QUICK MOVEMENT OF THE SYSTEM AND LOW
SNOW-TO-LIQUID RATIOS. THE HIGHEST AMOUNTS COULD EXCEED 8 INCHES IN
ISOLATED AREAS...BUT AGAIN LIMITED DURATION SHOULD PREVENT THAT FROM
BEING TOO WIDESPREAD.
HEADLINES...
GIVEN RATES AND BLOWING OF THE FALLING SNOW...WITH BASICALLY A
DOWNPOUR OF SNOW WITH CONCURRENT GUSTS OF 30+ MPH...HAVE OPTED TO GO
WITH A WARNING FOR THE AREA WITH THE LONGEST DURATION OF SNOW....EVEN
THOUGH NOT EVERYWHERE WILL SEE SIX PLUS INCHES OF SNOW.
UNCERTAINTY OF SNOW DURATION IN THE FAR SOUTH LED TO CONTINUING
THE WATCH. FURTHER NORTH HAVE AN ADVISORY...AND DID NOT INCLUDE
ROCKFORD BECAUSE IT LOOKS LIKE SNOWFALL SHOULD HAVE ENDED BY MUCH
OF IF NOT THE ENTIRE WED MORNING COMMUTE. IT IS CERTAINLY POSSIBLE
ADJUSTMENTS TO THE NORTHERN END OF HEADLINES ARE MADE TODAY.
WEDNESDAY NIGHT AND THURSDAY...
NOT MUCH CHANGE MADE TO THIS PERIOD. WEDNESDAY NIGHT LOOKS TO BE
PRETTY CHILLY WITH THE FRESH SNOW COVER AND DIMINISHING WINDS...AND
IF THE SKY CAN REMAIN CLEAR THE LOWS MAY BE WITHIN FIVE DEGREES OF
RECORD LOWS FOR MARCH 13TH.
MTF
EXTENDED PERIOD...FRIDAY THROUGH MONDAY...
AN AMPLIFIED LARGE SCALE UPPER LEVEL WEATHER PATTERN WILL REMAIN THE
MAIN STORY DURING THE EXTENDED PERIOD. THIS WILL LIKELY FEATURE
POSITIVE HEIGHT ANOMALIES ACROSS THE EASTERN PACIFIC AND THE PACIFIC
COAST OF THE CONUS...AND BELOW AVERAGE HEIGHTS ACROSS THE EASTERN
CONUS. ULTIMATELY THIS WILL RESULT IN BELOW AVERAGE TEMPERATURES
DURING MUCH OF THE EXTEND PERIOD.
IT APPEARS FRIDAY WILL BE THE WARMEST DAY OF THE EXTENDED. A CLIPPER
TYPE SYSTEM IS EXPECTED TO TRACK EASTWARD ACROSS THE UPPER GREAT
LAKES REGION ON FRIDAY...AND THIS SHOULD RESULT IN BREEZE...BUT
MILD...SOUTHWESTERLY FLOW ACROSS THE REGION. IT APPEARS TEMPERATURES
COULD WARM INTO THE 50S...BUT ANY REMAINING SNOW COVER FROM THE
SNOWFALL TONIGHT MAY HINDER THE MAGNITUDE OF WARMING SOME.
THIS WARM AIR WILL BE SHORT LIVED AS COLDER AIR WILL LIKELY BEGIN TO
SPILL BACK SOUTHWARD ACROSS THE AREA BY SATURDAY AS A COLD FRONT
DROPS ACROSS THE AREA. SOME LIGHT SNOW SHOWERS MAY ACCOMPANY THIS
COLDER AIR PUSH FRIDAY NIGHT. GUIDANCE IS HINTING AT DECENT SHORT
WAVE TROUGH DIGGING SOUTHEASTWARD ACROSS SOUTHERN WISCONSIN DURING
THIS TIME. IN SPITE OF THIS...I HAVE CHOSEN TO LEAVE THE FORECAST
DRY AT THIS TIME.
A VERY ACTIVE JET ACROSS THE PACIFIC WILL LIKELY CONTINUE TO DRIVE
DISTURBANCES EASTWARD ATOP A BUILDING WESTERN CONUS RIDGE INTO NEXT
WEEK. ALTHOUGH THE ACTUAL TIMING AND EVOLUTION OF THESE
DISTURBANCES IS HIGHLY UNCERTAIN AT THIS JUNCTURE...IT DOES APPEAR
THAT A NORTHWESTERLY UPPER LEVEL PATTERN ACROSS THE CENTRAL CONUS
COULD PRODUCE SOME ADDITIONAL CHANCES OF SNOW FOR PORTIONS OF THE
REGION LATER IN THE WEEKEND...DEPENDING ON THE ACTUALLY TRACK. WITH
THIS IN MIND...I HAVE LEFT SOME LOW END POPS IN FOR LATER IN THE
WEEKEND.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* GUSTY NORTHEAST WINDS 15-18 KTS THIS AFTERNOON.
* MIX OF LIGHT RAIN/LIGHT SNOW MID EVENING.
* SNOW DEVELOPING LATE EVENING WITH A PERIOD OF HEAVY SNOW AFTER
MIDNIGHT.
* BLOWING SNOW OVERNIGHT INTO WEDNESDAY MORNING.
* RAPIDLY DETERIORATING VIS/CIGS TO LIFR/VLIFR WITH SNOW.
* STRONG/GUSTY NORTHERLY WINDS OVERNIGHT INTO WEDNESDAY MORNING
WITH GUSTS 30-35 KTS POSSIBLE.
CMS/RODRIGUEZ
//DISCUSSION...UPDATED 12Z...
LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE EAST ACROSS
SOUTHERN ILLINOIS AND SOUTHERN INDIANA TONIGHT. LATEST 06Z
GUIDANCE CONTINUES TO SHOW AXIS OF HEAVIEST SNOW MOVING ACROSS
NORTH CENTRAL ILLINOIS DURING THE 06Z-12Z TIME PERIOD. WITH
CONFIDENCE INCREASING FOR THIS SOLUTION...HAVE MOVED TEMPO LOWER
CONDITIONS IN PREVIOUS FORECAST TO PREVAILING CONDITIONS FOR THE
SAME TIME PERIOD WITH THE 12Z TAFS. POSSIBLE FOR VISIBILITIES TO
DROP TO 1/4SM DURING THIS TIME WITH HEAVY SNOW WHICH COULD PRODUCE
SNOWFALL RATES OF 1 TO 2 INCHES PER HOUR. THE BAND WILL SHIFT EAST
TOWARD DAYBREAK WEDNESDAY...BUT LIGHT SNOW EXPECTED TO CONTINUE
THROUGH MID MORNING WEDNESDAY. INITIALLY THE SNOW MAY MIX WITH
RAIN AND BE RATHER WET BUT WILL BECOME DRIER AS COLDER AIR SPREADS
IN FROM THE NORTH. AS THIS HAPPENS...BLOWING SNOW WILL DEVELOP AND
WILL CONTINUE INTO WEDNESDAY MORNING. ALSO A SMALL POTENTIAL FOR A
FEW LIGHTNING STRIKES/THUNDERSNOW BUT TOO ISOLATED OF A CHANCE TO
INCLUDE IN THE FORECAST.
THE GRADIENT WILL QUICKLY TIGHTEN FROM EARLY/MID EVENING THROUGH
THE EARLY MORNING HOURS. NORTHERLY WINDS WILL LIKELY INCREASE INTO
THE 20-25KT RANGE WITH GUSTS INTO THE 30-35KT RANGE OVERNIGHT INTO
WEDNESDAY MORNING. WINDS WILL SLOWLY DIMINISH MID/LATE WEDNESDAY
MORNING INTO WEDNESDAY AFTERNOON.
IN THE SHORTER TERM...MID CLOUDS WILL CONTINUE TO LOWER THROUGH
THE DAY. AN AREA OF LIGHT RAIN WILL MOVE ACROSS SOUTHERN WISCONSIN
THIS AFTERNOON AND SLOWLY SAG INTO NORTHERN ILLINOIS TOWARD
EVENING. PRECIPITATION AMOUNTS WILL BE LIGHT AND BULK OF THIS
ACTIVITY SHOULD REMAIN NORTH OF THE TERMINALS...BUT DID INCLUDE
VICINITY MENTION AT RFD FOR THIS AFTERNOON. LIGHT/CALM WINDS TO
START WILL TURN NORTHEAST AND SLOWLY INCREASE THIS MORNING WITH
GUSTS INTO THE 14-18KT RANGE MID/LATE AFTERNOON. LIGHT FOG THIS
MORNING...MAINLY SOUTH OF THE TERMINALS WILL IMPROVE THROUGH MID/
LATE MORNING. CMS
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM FOR LIGHT RAIN/LIGHT SNOW THIS EVENING.
* HIGH FOR SNOW LATE THIS EVENING THROUGH WEDNESDAY MORNING...
MEDIUM FOR TIMING AND SPECIFIC TRENDS.
* HIGH FOR WINDS THROUGH THE PERIOD...MEDIUM ON TIMING/DIRECTIONS.
* HIGH FOR VFR THROUGH EARLY EVENING...MEDIUM ON CIG/VIS TRENDS
OVERNIGHT INTO WEDNESDAY MORNING.
CMS/RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT...DRY/VFR.
* THURSDAY...DRY/VFR. GUSTY SOUTHWEST WINDS.
* FRIDAY...DRY/VFR. GUSTY WESTERLY WINDS.
* SATURDAY...DRY/VFR.
* SUNDAY...SLIGHT CHANCE OF SNOW.
* MONDAY...DRY/VFR.
&&
.MARINE...
330 AM...LOW PRESSURE CURRENTLY OVER THE WESTERN PLAINS WILL MOVE
EAST TO SOUTHERN ILLINOIS LATE THIS EVENING AND THEN DEEPEN AS IT
REACHES NEW ENGLAND WEDNESDAY NIGHT. THE GRADIENT WILL TIGHTEN AS
THIS LOW PASSES SOUTH OF LAKE MICHIGAN WITH NORTHERLY WINDS STEADILY
INCREASING FROM THIS AFTERNOON INTO EARLY WEDNESDAY MORNING. GALES
APPEAR TO BEGIN LATE THIS EVENING AND INCREASE TO 45 KTS OVERNIGHT
AND CONTINUE THROUGH MIDDAY WEDNESDAY...SLOWLY DIMINISHING WEDNESDAY
AFTERNOON INTO WEDNESDAY EVENING. OTHER THAN TWEAKING WIND SPEEDS/
GUSTS UP...NO SIGNIFICANT CHANGES TO GOING FORECAST/GRIDS OR
HEADLINES. WINDS WILL QUICKLY DIMINISH WEDNESDAY NIGHT/EARLY
THURSDAY MORNING AS A RIDGE OF HIGH PRESSURE MOVES ACROSS THE LAKE.
WINDS THEN TURN SOUTHWESTERLY AND INCREASE TO 30 KTS AS LOW PRESSURE
MOVES ACROSS ONTARIO THURSDAY NIGHT AND FRIDAY...WITH A TRAILING
COLD FRONT FROM THIS LOW MOVING ACROSS THE WESTERN LAKES FRIDAY
AFTERNOON INTO FRIDAY EVENING.
VISIBLE SATELLITE IMAGERY FROM MONDAY SHOWS SOME OPEN WATER IN THE
ILLINOIS NEARSHORE ZONES AND HAVE ACCOUNTED FOR THIS WITH WAVE
HEIGHTS IN THIS MORNING/S FORECAST. HOWEVER...WITH THE EXPECTED
STRONG NORTHERLY WINDS...ICE IN THE OPEN WATERS IS EXPECTED TO BE
PUSHED BACK TO THE ILLINOIS SHORE TONIGHT. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032...10 PM TUESDAY TO 1 PM WEDNESDAY.
WINTER WEATHER ADVISORY...ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012...10 PM TUESDAY TO 10 AM WEDNESDAY.
WINTER STORM WATCH...ILZ033-ILZ039...1 AM WEDNESDAY TO 1 PM
WEDNESDAY.
IN...WINTER STORM WARNING...INZ001-INZ002...10 PM TUESDAY TO 1 PM
WEDNESDAY.
WINTER STORM WATCH...INZ010-INZ011-INZ019...1 AM WEDNESDAY TO 1
PM WEDNESDAY.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...MIDNIGHT WEDNESDAY TO 9 PM WEDNESDAY.
GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...3 AM WEDNESDAY TO 4 PM WEDNESDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS TOPEKA KS
ISSUED BY NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
326 PM CDT Tue Mar 11 2014
.SHORT TERM...(This Evening through Tonight)
Issued at 322 PM CDT TUE MAR 11 2014
Late this afternoon, surface boundary bisects the CWA stretching
just west of Wichita to the northeast to Topeka and further east
north of KMCI. Several convergence zones ahead this boundary, with
strongest axis stretching along the I-35/335 corridor. Will need to
watch for potential development of convection along this corridor
through 6pm as primary cold front moves east. Instability along and
head of this front remains meager, with RAP analysis only indicating
CAPE values 100-300 J/KG. If storms would happen to develop, the
main impact would be small hail with the longevity of convection
in the CWA minimal.
The other concern heading into the overnight hours will be strong
gradient winds. We`re already seeing advisory level winds in the
far NW portion of the CWA at this hour, and as the surface boundary
settles southeast, these strong gradient winds will swing through
the CWA. By midnight, sfc pressure gradient should begin to weaken
as the developing sfc low moves through the MO bootheel.
The shortwave responsible for these strong winds and increasing
precipitation chances is just beginning to enter the Western Plains
this afternoon. A linear band of mid-level frontogenesis across
NE/IA slopes back to western KS at 3pm. Short term model guidance
continues to suggest that this band will slowly move southeast this
evening. While the western flank of the mid-level lift should hold
together the further southeast it tracks, the eastern areas of
precip across NE/IA will dissipate as a new baroclinic zone is
reestablished further south across eastern KS and northern
Missouri. Precipitation should blossom shortly after 00Z along the
eastern edges of the CWA. Given the position of the shortwave and
how the wave pivots eastward, the majority of the heavy
precipitation should take place just east of the CWA. Latest
hopWRF, HRRR, RAP support the idea of a brief window of 3-5 hrs of a
rain/snow mixture bisecting the CWA with most of the activity
diminishing or moving east by 1am. Accumulations should remain light
given the warm grounds, but could see up to an inch of snow in some
spots where efficient rates can overtake boundary layer temps.
.LONG TERM...(Wednesday Night through Tuesday)
Issued at 322 PM CDT TUE MAR 11 2014
After the past two days, Wednesday will feel
chilly with temperatures rebounding into the upper 40s to lower
50s. Will watch for an increase in low-level clouds late morning,
as a secondary wave rotates southward into the area. A quick rebound
above normal is expected by Thursday and Friday ahead of yet another
shortwave pivoting through the southern Rockies. Temperatures on
Thursday will rebound into the 60s, with a front dropping southward
on Friday lowering readings a few degrees.
Saturday-Monday: The aforementioned shortwave should pass far enough
to the south Friday night to have minimal impact on the CWA leaving
conditions pleasant for Saturday. A slightly more amplified flow
pattern will drop colder air southward again on Sunday, but this
cooldown should last no longer than a day as increasing
southwesterly flow ushers above normal temperatures into the region
to begin next week. Have bumped up temperatures for Monday.
&&
.AVIATION...(For the 18Z TAFs through 18Z Wednesday Afternoon)
Issued at 1222 PM CDT TUE MAR 11 2014
Frontal boundary remains just northwest of the Manhattan terminal
this afternoon arching NE along the KS/NE state line. This
boundary will continue to sink southeast and reach the Topeka area
towards 22z. Winds will increase immediately behind this front
with sustained winds between 25-30 knots an occasional gusts
approaching 40 knots.
There appears to be two areas of precipitation that will move
through the region later this afternoon and tonight. Initial area
of precipitation dropping southeast of out SW Nebraska associated
with PV anomaly will gradually begin to merge with an intense
area of frontogenesis focused just east of the CWA. Have timed
initial development of rain around 00z, with a quick transition to
rain/snow or even completely to snow by 03z. The progressive
nature of the wave should force precipitation and associated MVFR to
IFR ceilings/VIS through the terminals by 06z. After that point,
we`ll see a gradual increase in ceilings, but winds will remain
breezy through the night.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY from 4 PM this afternoon to 1 AM CDT Wednesday FOR
KSZ011-012-022>024-026-036>040-054>056-058-059.
WIND ADVISORY until 10 PM CDT this evening FOR KSZ008>010-020-
021-034-035.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 1 AM CDT Wednesday FOR KSZ011-012-022>024-
026-036>040-054>056-058-059.
WIND ADVISORY until 10 PM CDT this evening FOR KSZ008>010-020-
021-034-035.
&&
$$
SHORT TERM...DUX
LONG TERM...DUX
AVIATION...DUX
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
101 PM CDT Tue Mar 11 2014
...Updated for aviation discussion...
.SYNOPSIS...
ISSUED AT 343 AM CDT TUE MAR 11 2014
Water vapor loop as of 08Z showed an impressive shortwave trough
continuing to dig southeastward into Utah. RAP analysis had a 400mb
potential vorticity (PV) anomaly extending from the base of the
trough near Great Salt Lake northeastward into eastern
Washington...suggesting a little more digging before the wave
translates eastward. Warmest temperatures in the lower troposphere
(850mb) were found across the High Plains of western Kansas into
West Texas (+17C at both North Platte and Dodge City; +20C at
Amarillo). The 08Z surface analysis showed a deepening surface low
centered near the western Nebraska-Kansas state border. Surface
winds continued to respond with overnight winds in the 10 to 13 knot
range, helping keep temperatures from dropping much. It was still in
the lower to mid 40s across much of the southwest and west central
Kansas region. Surface cold frontogenesis was noted across
northeastern Wyoming into the northern Nebraska Panhandle.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 343 AM CDT TUE MAR 11 2014
Moderate to high impact wind event this afternoon/evening is the
main forecast challenge and how to handle this event with headlines
(advisory vs. warning). Now that the forecast wind event is within
higher resolution short-term models (RAP13, for instance) temporal
range, we are gaining a bit higher confidence in the wind forecast.
As the surface low moves southeast into central Kansas, it will
continue to deepen down to about 995mb while surface
anticyclogenesis will ramp up across the northern Rockies and
adjacent High Plains. This will induce a very tight pressure
gradient across western Kansas by midday...and especially this
afternoon.
The combined effect of the pressure gradient and the
isallobaric wind due to pressure change, will likely lead to
sustained winds around 40 mph for areas along and west of Highway
283 corridor...especially in the 22-01Z time frame. Forecast
soundings off the NAM12 and RAP13 both show around 35 knots just off
the surface around 900mb at Dodge City at 21Z with mixing up to
800-825mb. The winds around 800-850mb will pick up quite a bit as
the north wind low level jet strengthens west of the low at this
level. For Dodge City, the 00Z forecast soundings support a high
wind event (40mph sustained and/or 58mph gusts) with 50 knots shown
by both the NAM12 and RAP13 at the top of the mixed layer (which by
that point will be due to vigorous cold advection). Based on this
information, we will upgrade to a High Wind Warning for US283
corridor (Ness City down to Englewood) west to the Colorado border.
Per collaboration with surrounding offices, we will also include
areas of blowing dust where the High Wind Warning will be in effect
and hit it pretty hard in the NPW product. As far as precipitation
goes, the only area expected to see any measurable precipitation
will be the I-70 corridor, and will carry around 50 POPs up there. A
few tenths of an inch of wet snow may accumulate during the 23-02Z
time frame in particular.
.LONG TERM...(Wednesday through Monday)
ISSUED AT 300 AM CDT TUE MAR 11 2014
Medium range models indicate an upper level shortwave breaking
away from a larger scale trough Wednesday as it digs southeast
across the Rockies, and developing into a closed off upper level
low across the Intermountain West. Meanwhile, a general westerly
flow aloft will prevail across the Western High Plains through the
end of the week. This will result in dry conditions persisting
across western Kansas through Thursday night with insufficient
low/mid level moisture present. The closed off upper level low in
the Desert Southwest is then expected to open up and push eastward
into the South Plains early Friday bringing marginal precip
chances to the Texas and Oklahoma panhandles based on the
projected track of the shortwave. Cannot rule out a slight chance
for light rain across extreme southern portions of southwest and
south central Kansas Friday as the upper level system skirts
across our southern fringe.
Much cooler temperatures are likely Wednesday as arctic air spills
southward into western Kansas in wake of a departing cold front. The
NAM/GFS/ECMWF show H85 temperatures dropping well below 0C across
central and western Kansas initially Tuesday night. A slight
rebound to around 0C across central Kansas to near 5C along the
Colorado border is expected Wednesday afternoon due to some
northwesterly downsloping developing. Expect highs up into the
upper 40s(F) to possibly the lower to mid 50s(F) under decreasing
cloud cover. A quick bounce back to warmer temperatures will occur
Thursday as the arctic high dips further south across Texas while
lee side troughing redevelops across eastern Colorado. This will
quickly return a southwesterly downslope flow to western Kansas
pushing H85 temperatures up into the lower to mid Teens(C) across
central and western Kansas. Highs will easily reach the 60s(F)
Thursday afternoon with near 70F not out of the question in some
locations. Another cold front is projected to push through western
Kansas early Friday once again dropping temperatures across the
area.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1242 PM CDT TUE MAR 11 2014
A strong upper level system will pass across western Kansas this
afternoon and evening. Strong north winds at 30-40kts will persist
though 03z in the wake of surface low pressure, before subsiding.
Blowing dust could restrict visbys to 4sm through 23z at GCK/DDC.
Some light rain or snow is likely at KHYS between 23 and 04z as
the upper level trough axis approaches, and this could restrict
visibilities to MVFR. MVFR CIGS can be expected after 22-23z at
HYS/GCK/DDC, before clearing develops after 4z in the wake of the
upper level system.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 59 28 53 26 / 20 20 0 0
GCK 57 27 52 24 / 20 20 0 0
EHA 59 28 50 28 / 10 10 0 0
LBL 62 27 52 25 / 10 10 0 0
HYS 48 28 52 24 / 60 60 0 0
P28 68 31 54 28 / 10 20 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING until 11 PM CDT /10 PM MDT/ this evening FOR
KSZ043>045-061>064-074>078-084>088.
WIND ADVISORY until 11 PM CDT this evening FOR KSZ046-065-066-
079>081-089-090.
WIND ADVISORY until 11 PM CDT this evening FOR KSZ030-031.
&&
$$
SYNOPSIS...Umscheid
SHORT TERM...Umscheid
LONG TERM...JJohnson
AVIATION...Finch
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
620 AM CDT Tue Mar 11 2014
...UPDATE TO AVIATION...
.SYNOPSIS...
ISSUED AT 343 AM CDT TUE MAR 11 2014
Water vapor loop as of 08Z showed an impressive shortwave trough
continuing to dig southeastward into Utah. RAP analysis had a 400mb
potential vorticity (PV) anomaly extending from the base of the
trough near Great Salt Lake northeastward into eastern
Washington...suggesting a little more digging before the wave
translates eastward. Warmest temperatures in the lower troposphere
(850mb) were found across the High Plains of western Kansas into
West Texas (+17C at both North Platte and Dodge City; +20C at
Amarillo). The 08Z surface analysis showed a deepening surface low
centered near the western Nebraska-Kansas state border. Surface
winds continued to respond with overnight winds in the 10 to 13 knot
range, helping keep temperatures from dropping much. It was still in
the lower to mid 40s across much of the southwest and west central
Kansas region. Surface cold frontogenesis was noted across
northeastern Wyoming into the northern Nebraska Panhandle.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 343 AM CDT TUE MAR 11 2014
Moderate to high impact wind event this afternoon/evening is the
main forecast challenge and how to handle this event with headlines
(advisory vs. warning). Now that the forecast wind event is within
higher resolution short-term models (RAP13, for instance) temporal
range, we are gaining a bit higher confidence in the wind forecast.
As the surface low moves southeast into central Kansas, it will
continue to deepen down to about 995mb while surface
anticyclogenesis will ramp up across the northern Rockies and
adjacent High Plains. This will induce a very tight pressure
gradient across western Kansas by midday...and especially this
afternoon.
The combined effect of the pressure gradient and the
isallobaric wind due to pressure change, will likely lead to
sustained winds around 40 mph for areas along and west of Highway
283 corridor...especially in the 22-01Z time frame. Forecast
soundings off the NAM12 and RAP13 both show around 35 knots just off
the surface around 900mb at Dodge City at 21Z with mixing up to
800-825mb. The winds around 800-850mb will pick up quite a bit as
the north wind low level jet strengthens west of the low at this
level. For Dodge City, the 00Z forecast soundings support a high
wind event (40mph sustained and/or 58mph gusts) with 50 knots shown
by both the NAM12 and RAP13 at the top of the mixed layer (which by
that point will be due to vigorous cold advection). Based on this
information, we will upgrade to a High Wind Warning for US283
corridor (Ness City down to Englewood) west to the Colorado border.
Per collaboration with surrounding offices, we will also include
areas of blowing dust where the High Wind Warning will be in effect
and hit it pretty hard in the NPW product. As far as precipitation
goes, the only area expected to see any measurable precipitation
will be the I-70 corridor, and will carry around 50 POPs up there. A
few tenths of an inch of wet snow may accumulate during the 23-02Z
time frame in particular.
.LONG TERM...(Wednesday through Monday)
ISSUED AT 300 AM CDT TUE MAR 11 2014
Medium range models indicate an upper level shortwave breaking
away from a larger scale trough Wednesday as it digs southeast
across the Rockies, and developing into a closed off upper level
low across the Intermountain West. Meanwhile, a general westerly
flow aloft will prevail across the Western High Plains through the
end of the week. This will result in dry conditions persisting
across western Kansas through Thursday night with insufficient
low/mid level moisture present. The closed off upper level low in
the Desert Southwest is then expected to open up and push eastward
into the South Plains early Friday bringing marginal precip
chances to the Texas and Oklahoma panhandles based on the
projected track of the shortwave. Cannot rule out a slight chance
for light rain across extreme southern portions of southwest and
south central Kansas Friday as the upper level system skirts
across our southern fringe.
Much cooler temperatures are likely Wednesday as arctic air spills
southward into western Kansas in wake of a departing cold front. The
NAM/GFS/ECMWF show H85 temperatures dropping well below 0C across
central and western Kansas initially Tuesday night. A slight
rebound to around 0C across central Kansas to near 5C along the
Colorado border is expected Wednesday afternoon due to some
northwesterly downsloping developing. Expect highs up into the
upper 40s(F) to possibly the lower to mid 50s(F) under decreasing
cloud cover. A quick bounce back to warmer temperatures will occur
Thursday as the arctic high dips further south across Texas while
lee side troughing redevelops across eastern Colorado. This will
quickly return a southwesterly downslope flow to western Kansas
pushing H85 temperatures up into the lower to mid Teens(C) across
central and western Kansas. Highs will easily reach the 60s(F)
Thursday afternoon with near 70F not out of the question in some
locations. Another cold front is projected to push through western
Kansas early Friday once again dropping temperatures across the
area.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
ISSUED AT 620 AM CDT TUE MAR 11 2014
VFR conditions will prevail at all TAF sites through early this
afternoon. Low level stratus is expected to develop behind a cold
front as it pushes across western Kansas this afternoon. MVFR
cigs will be possible late this afternoon into this evening at
all TAF sites as a result. Strong northerly winds will develop
behind the cold front this afternoon with sustained winds of 35 to
45kt and gusts up to 50kt. This may result in periods of blowing
dust reducing visibilities to MVFR in the vicinity of KGCK and
KDDC. Brief IFR vsbys cannot be ruled out. Light snow will be
possible in the vicinity of KHYS this evening which may result in
IFR vsbys in blowing snow. The winds will become more
northwesterly tonight while subsiding somewhat.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 59 27 51 26 / 20 20 0 0
GCK 56 25 50 24 / 20 20 0 0
EHA 63 27 48 28 / 10 10 0 0
LBL 64 26 50 25 / 10 10 0 0
HYS 55 27 50 24 / 40 50 0 0
P28 62 30 52 28 / 10 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING from 1 PM CDT /Noon MDT/ this afternoon to 11
PM CDT /10 PM MDT/ this evening FOR KSZ043>045-061>064-074>078-
084>088.
WIND ADVISORY from 1 PM this afternoon to 11 PM CDT this evening
FOR KSZ030-031-046-065-066-079>081-089-090.
&&
$$
SYNOPSIS...Umscheid
SHORT TERM...Umscheid
LONG TERM...JJohnson
AVIATION...JJohnson
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
344 AM CDT Tue Mar 11 2014
...Updated synopsis and short term sections...
.SYNOPSIS...
ISSUED AT 343 AM CDT TUE MAR 11 2014
Water vapor loop as of 08Z showed an impressive shortwave trough
continuing to dig southeastward into Utah. RAP analysis had a 400mb
potential vorticity (PV) anomaly extending from the base of the
trough near Great Salt Lake northeastward into eastern
Washington...suggesting a little more digging before the wave
translates eastward. Warmest temperatures in the lower troposphere
(850mb) were found across the High Plains of western Kansas into
West Texas (+17C at both North Platte and Dodge City; +20C at
Amarillo). The 08Z surface analysis showed a deepening surface low
centered near the western Nebraska-Kansas state border. Surface
winds continued to respond with overnight winds in the 10 to 13 knot
range, helping keep temperatures from dropping much. It was still in
the lower to mid 40s across much of the southwest and west central
Kansas region. Surface cold frontogenesis was noted across
northeastern Wyoming into the northern Nebraska Panhandle.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 343 AM CDT TUE MAR 11 2014
Moderate to high impact wind event this afternoon/evening is the
main forecast challenge and how to handle this event with headlines
(advisory vs. warning). Now that the forecast wind event is within
higher resolution short-term models (RAP13, for instance) temporal
range, we are gaining a bit higher confidence in the wind forecast.
As the surface low moves southeast into central Kansas, it will
continue to deepen down to about 995mb while surface
anticyclogenesis will ramp up across the northern Rockies and
adjacent High Plains. This will induce a very tight pressure
gradient across western Kansas by midday...and especially this
afternoon.
The combined effect of the pressure gradient and the
isallobaric wind due to pressure change, will likely lead to
sustained winds around 40 mph for areas along and west of Highway
283 corridor...especially in the 22-01Z time frame. Forecast
soundings off the NAM12 and RAP13 both show around 35 knots just off
the surface around 900mb at Dodge City at 21Z with mixing up to
800-825mb. The winds around 800-850mb will pick up quite a bit as
the north wind low level jet strengthens west of the low at this
level. For Dodge City, the 00Z forecast soundings support a high
wind event (40mph sustained and/or 58mph gusts) with 50 knots shown
by both the NAM12 and RAP13 at the top of the mixed layer (which by
that point will be due to vigorous cold advection). Based on this
information, we will upgrade to a High Wind Warning for US283
corridor (Ness City down to Englewood) west to the Colorado border.
Per collaboration with surrounding offices, we will also include
areas of blowing dust where the High Wind Warning will be in effect
and hit it pretty hard in the NPW product. As far as precipitation
goes, the only area expected to see any measurable precipitation
will be the I-70 corridor, and will carry around 50 POPs up there. A
few tenths of an inch of wet snow may accumulate during the 23-02Z
time frame in particular.
.LONG TERM...(Wednesday through Monday)
ISSUED AT 300 AM CDT TUE MAR 11 2014
Medium range models indicate an upper level shortwave breaking
away from a larger scale trough Wednesday as it digs southeast
across the Rockies, and developing into a closed off upper level
low across the Intermountain West. Meanwhile, a general westerly
flow aloft will prevail across the Western High Plains through the
end of the week. This will result in dry conditions persisting
across western Kansas through Thursday night with insufficient
low/mid level moisture present. The closed off upper level low in
the Desert Southwest is then expected to open up and push eastward
into the South Plains early Friday bringing marginal precip
chances to the Texas and Oklahoma panhandles based on the
projected track of the shortwave. Cannot rule out a slight chance
for light rain across extreme southern portions of southwest and
south central Kansas Friday as the upper level system skirts
across our southern fringe.
Much cooler temperatures are likely Wednesday as arctic air spills
southward into western Kansas in wake of a departing cold front. The
NAM/GFS/ECMWF show H85 temperatures dropping well below 0C across
central and western Kansas initially Tuesday night. A slight
rebound to around 0C across central Kansas to near 5C along the
Colorado border is expected Wednesday afternoon due to some
northwesterly downsloping developing. Expect highs up into the
upper 40s(F) to possibly the lower to mid 50s(F) under decreasing
cloud cover. A quick bounce back to warmer temperatures will occur
Thursday as the arctic high dips further south across Texas while
lee side troughing redevelops across eastern Colorado. This will
quickly return a southwesterly downslope flow to western Kansas
pushing H85 temperatures up into the lower to mid Teens(C) across
central and western Kansas. Highs will easily reach the 60s(F)
Thursday afternoon with near 70F not out of the question in some
locations. Another cold front is projected to push through western
Kansas early Friday once again dropping temperatures across the
area.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1219 AM CDT TUE MAR 11 2014
South to southwest winds overnight will gradually veer around to the
west-northwest by mid-morning. Winds will increase to around 20 to
25 knots sustained by midday and continue to ramp up to 28 to 32
knots sustained late afternoon from the north-northwest as a strong
cold front moves in. A few wind gusts will be around 45 knots or
higher between 21z Tuesday and 03z Wednesday with some MVFR ceilings
also moving in during this time. Up at HYS, light snow will likely
bring the flight category down to IFR for a few hours during the
early to mid evening hours. Snow accumulations are expected to be
minimal at less than an inch.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 59 27 51 26 / 20 20 0 0
GCK 56 25 50 24 / 20 20 0 0
EHA 63 27 48 28 / 10 10 0 0
LBL 64 26 50 25 / 10 10 0 0
HYS 55 27 50 24 / 40 50 0 0
P28 62 30 52 28 / 10 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING from 1 PM CDT /Noon MDT/ this afternoon to 11
PM CDT /10 PM MDT/ this evening FOR KSZ043>045-061>064-074>078-
084>088.
WIND ADVISORY from 1 PM this afternoon to 11 PM CDT this evening
FOR KSZ030-031-046-065-066-079>081-089-090.
&&
$$
SYNOPSIS...Umscheid
SHORT TERM...Umscheid
LONG TERM...JJohnson
AVIATION...Umscheid
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1120 PM EDT WED MAR 12 2014
.UPDATE...
ISSUED AT 1110 PM EDT WED MAR 12 2014
THE GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT RADAR TRENDS. NEARLY AN
INCH OF SNOW HAS FALLEN SO FAR THIS EVENING AT JKL WITH ABOUT AN INCH
REPORTED FROM A SPOTTER AT THORNTON IN LETCHER COUNTY. MOST OF THE
REMAINING SNOW SHOWERS OVERNIGHT SHOULD BE OVER THE NE COUNTIES AND
TO THE SOUTH AND EAST OF JKL OVERNIGHT. TEMPERATURES HAVE BEEN A BIT SLOWER
TO DROP OFF THIS EVENING THAN EXPECTED AND OPTED TO INCREASE MIN T A
DEGREE OR TWO ON AVERAGE. WE HAVE ISSUED AN SPS TO HIGHLIGHT THE
POTENTIAL FOR ROADS TO BECOME ICY OVERNIGHT WITH SCATTERED SNOW SHOWERS
AND POSSIBLY ANY LINGERING WATER FREEZING. THE WSW REMAINS IN EFFECT
FOR THE HIGHER TERRAIN NEAR THE VA BORDER. CONSIDERING THE SNOWFALL
AT JKL AND THE SPOTTER REPORT IN LETCHER COUNTY WE HAVE OPTED TO MOVE
THE REFERENCE IN THE WSW DOWN TO 2000 FEET. HOURLY GRIDS HAVE BEEN
FRESHENED UP.
UPDATE ISSUED AT 830 PM EDT WED MAR 12 2014
WIND GUSTS HAVE SLACKENED TO 30 MPH OR LESS AND THUS WE HAVE OPTED TO
CANCEL THE WIND ADVISORY EARLY. MOIST NORTHWEST FLOW IS BRINGING
SNOW SHOWERS TO MUCH OF THE REGION. SOME OF THE RIDGETOPS...PARTICULARLY
THOSE ABOVE 2000 FEET ARE BELOW FREEZING WITH THESE HIGHEST OF
ELEVATIONS NOW IN THE MID AND UPPER 20S. RADAR TRENDS AND THE 18Z NAM
SEEM TO FAVOR THE MOST PERSISTENT SNOW SHOWERS OVER THE FEW HOURS
NEAR OR JUST WEST OF JKL SOUTH INTO HARLAN AND LETCHER COUNTIES. THE
SFC LOW IS NOW CENTERED IN THE VICINITY OF NEW YORK CITY WITH COLDER AND
DRIER AIR ADVECTING SOUTH ON THE WEST SIDE OF THE LOW. AS THE SYSTEM
PULLS ON OFF FURTHER TO THE NORTH AND EAST...AND THE UPPER LEVEL
TROUGH EXITS TO THE EAST OVERNIGHT...SFC HIGH PRESSURE WILL BUILD
TOWARD THE REGION. THIS SHOULD LEAD TO A GRADUAL TAPERING OF THE SNOW
SHOWERS TO FLURRIES LATER ON TONIGHT INTO EARLY ON THURSDAY. AT THIS POINT...
THE INHERITED LOW TEMPERATURES LOOK FINE. HOURLY TEMPERATURE
AND DEWPOINT CURVES AS WELL AS WINDS HAVE BEEN ADJUSTED BASED ON
RECENT TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 315 PM EDT WED MAR 12 2014
18Z SFC ANALYSIS SHOWS THE DEEP LOW NOW OVER SOUTHWESTERN
PENNSYLVANIA WITH ITS COLD FRONT EAST OF KENTUCKY. THIS FRONT WAS
ACCOMPANIED AND TRAILED BY THE HIGHEST WINDS OF THE DAY WITH MANY
GUSTS TO 45 AND 50 MPH REPORTED IN ADDITION TO A 54 MPH GUST AT THE
KNOTT COUNTY MESONET. THE WINDS WILL CONTINUE GUSTY INTO THE EVENING
AS THE COLD AIR CONTINUES TO POUR INTO THIS PART OF THE STATE. THESE
WINDS ARE BRINGING IN THE SOON TO BE SUB FREEZING AIR WITH MID 30S
ALREADY NOTED IN THE NORTHWEST PARTS OF THE AREA WHILE MID 40S HOLD
IN THE FAR EAST...THOUGH BLACK MOUNTAIN IS DOWN TO 38 DEGREES.
DEWPOINTS ARE IN THE LOWER 30S NORTH TO THE UPPER 30S ACROSS THE
SOUTHEAST.
THE UPSLOPE FLOW IS KICKING IN ACROSS THE AREA AND WE CAN SEE THE
RAIN SHOWERS REDEVELOPING THROUGH THE HEART OF THE CWA. SOME FLURRIES
HAVE BEEN REPORTED WITH THESE HERE AT JKL...AND ALSO IN OUR NORTHERN
FRINGES...ON TRACK WITH EXPECTATIONS AND TIMING FROM THE LATEST HRRR.
THIS MODEL ALSO HAS BETTER REDEVELOPMENT OF SNOW TOWARD DUSK. AFTER
REVIEWING THE LATEST MODEL GUIDANCE...AND IN PARTICULAR THE
HRRR...HAVE DECIDED TO HOIST A WINTER WEATHER ADVISORY FOR THREE OF
OUR NORTHERN BORDER COUNTIES WITH VIRGINIA FOR A 1 TO 2 INCH SNOWFALL
MAINLY AT ELEVATIONS ABOVE 2500 FEET.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE DEEP LATE WINTER
TROUGH CROSSING THE OHIO VALLEY TONIGHT. THEY ALL HAVE ENERGY
WRAPPING IN HERE THROUGH 12Z THURSDAY BEFORE THE MASS OF IT PULLS
OFF THE EAST AND HEIGHTS QUICKLY RISE DURING THE DAY THURSDAY. THESE
HEIGHTS FLATTEN OUT LATER THURSDAY NIGHT AS A SHALLOW TROUGH MOVES
THIS WAY FROM THE NORTHERN PLAINS. WITH THIS GOOD AGREEMENT...AND THE
ONGOING WINTER STORM...HAVE LEANED MOST HEAVILY ON THE HIGHER
RESOLUTION NAM12 AND HRRR FOR WEATHER DETAILS.
SENSIBLE WEATHER WILL FEATURE THE UPSLOPE RAIN...CHANGING TO SNOW
LATE THIS AFTERNOON AND EARLY EVENING AND THEN CONTINUING THROUGH
THE EVENING FOR MOST LOCATIONS. THE SNOW WILL LINGER THE LONGEST IN
THE FAR EASTERN PARTS OF THE AREA THROUGH THE MIDDLE OF THE NIGHT.
LOOKING AT AN INCH OR LESS OF ACCUMULATION FOR MOST AREAS...WITH
THOSE HIGHER TOTALS MAINLY ON THE RIDGES. DO EXPECT NEARLY ALL SPOTS
TO GET A DUSTING OF SNOW EVEN IN THE VALLEYS...BUT THE LAG IN THE
COOLING OF THE ROADS SHOULD KEEP THEM MOSTLY CLEAR. THE FAR SOUTHEAST
PARTS OF THE CWA ARE A BIT DIFFERENT...THOUGH...AS THE UPSLOPE WILL
HOLD IN LONGER THERE...TEMPERATURES ARE DROPPING OFF QUICKER IN THE
HIGHER ELEVATIONS...THE HRRR IS HITTING THEM HARDEST WITH QPF...AND
THEY HAVE HIGHER ELEVATION WELL TRAVELED ROADS. FOR THESE REASONS
HAVE ISSUED A WSW FOR HARLAN...LETCHER...AND PIKE COUNTIES THROUGH
4Z...MATCHING UP WITH MRX IN WISE COUNTY.
THE SNOW WILL TAPER TO FLURRIES AND END LATE TONIGHT AND EARLY
THURSDAY MORNING FROM WEST TO EAST. TEMPERATURES WILL BOTTOM OUT IN
THE UPPER TEENS MOST PLACES BY DAWN WITH STILL ENOUGH OF A BREEZE TO
GENERATE WIND CHILLS IN THE SINGLE DIGITS OR NEAR ZERO ON THE HIGHEST
RIDGES. THE LOW CLOUDS WILL CLEAR OUR LATER THURSDAY MORNING WITH
SUNSHINE LIKELY EVAPORATING ANY OF THE SNOW FROM THIS SYSTEM BY MID
AFTERNOON DESPITE TEMPERATURES STRUGGLING TO GET TOO DEEP INTO THE
30S. A PARTLY CLOUDY SKY ON THURSDAY NIGHT WILL SET THE STAGE FOR A
MILDER NIGHT...BUT THIS WILL ALSO REPRESENT A DECENT RIDGE TO VALLEY
TEMPERATURE SPLIT SET UP.
USED A MODIFIED COLDER VERSION OF THE CONSSHORT FOR TEMPS DURING THE
NEXT 24 HOURS AND THEN FAVORED THE NAM12 DIURNAL CURVE WITH ADJUSTED
CONSALL MAX AND MIN T STARTING POINTS THROUGH FRIDAY MORNING. ALSO...
USED THE BCCONSSHORT FOR TD AND WINDS WITH THE CONSALL AFTER THE
FIRST 24 HOURS. THESE WERE MASSAGED FOR THE CURRENT CONDITIONS AND
TRENDS. AS FOR POPS...ENDED UP ON THE HIGH SIDE OF ALL GUIDANCE GIVEN
ITS POOR HISTORY OF PICKING UP ON LOW QPF UPSLOPE SNOW EVENTS.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 325 PM EDT WED MAR 12 2014
SPLIT FLOW PATTERN WILL BE IN PLACE AT THE BEGINNING OF THE LONG
TERM PORTION OF THE FORECAST WITH NEAR ZONAL FLOW ACROSS THE OH AND
TN VALLEYS. AT THE SURFACE HIGH PRESSURE WILL BE TO OUR SOUTHEAST
WITH SOUTHWEST LOW LEVEL FLOW ACROSS OUR AREA. AS A RESULT TEMPERATURES
WILL WARM NICELY WITH MAXIMUM TEMPERATURES ON FRIDAY 20 TO 25
DEGREES WARMER THAN ON THURSDAY.
AS WE MOVE INTO THE WEEKEND A SOUTHERN STREAM SHORT WAVE WILL EMERGE
FROM THE SOUTHERN PLAINS WITH THE ASSOCIATED SURFACE LOW TRACKING
ACROSS THE LOWER MS VALLEY AND THE SOUTHEAST UNITED STATES. AT THE
SAME TIME A NORTHERN STREAM SHORT WAVE WILL BE DROPPING SE FROM THE
NORTHERN PLAINS. THE COMBINED EFFECTS WILL BE TO BRING A CHANCE OF
PRECIPITATION TO THE AREA FOR THE WEEKEND. THERE WILL ONLY BE LOW
CHANCES OF PRECIPITATION ON SATURDAY...WITH PRECIPITATION CHANCES
PEAKING ON SUNDAY. TEMPERATURES WILL BE WARM ENOUGH THAT ANY
PRECIPITATION FROM FRIDAY NIGHT INTO SUNDAY WILL BE IN THE FORM OF
RAIN. ENOUGH COLD AIR LOOKS TO WORK INTO THE AREA ON THE BACKSIDE OF
THE SYSTEM SUNDAY NIGHT INTO EARLY MONDAY MORNING THAT PRECIPITATION
COULD END AS SNOW. THERE IS NOT GOOD MODEL AGREEMENT AT THIS POINT
IN TIME...BUT SOME LIGHT SNOW ACCUMULATION LOOKS POSSIBLE.
THERE IS POOR MODEL AGREEMENT AS WE MOVE INTO NEXT WEEK AND
CONFIDENCE IN THE VARIOUS MODEL SOLUTIONS DECREASES. AFTER A COLD
START TO THE WEEK...TEMPERATURES WILL WARM...BUT THE WHEN AND WHERE
OF THE NEXT SHORT WAVE TO AFFECT THE AREA ARE UNCERTAIN. FOR NOW
WILL KEEP THE WEATHER DRY THROUGH TUESDAY NIGHT...AND BRING A SLIGHT
CHANCE OF SHOWERS INTO THE FAR WESTERN PART OF THE FORECAST AREA ON
WEDNESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 835 PM EDT WED MAR 12 2014
MVFR AND OR IFR CIGS AND OCCASIONALLY VIS WILL AFFECT THE AREA INTO
THE EVENING BEHIND THE COLD FRONT AS AN UPPER LEVEL DISTURBANCE AND
UPSLOPE FLOW COMBINE TO BRING SNOW SHOWERS TO THE REGION. JKL AND
SJS WILL BE MOST AFFECTED BY THE SNOW SHOWERS. WINDS MAY GUST AS
HIGH AS 20 TO 30 KT THROUGH THE 3Z TO 6Z PERIOD BEFORE THE PRESSURE
GRADIENT SLACKENS. CEILINGS WILL GRADUALLY IMPROVE AFTER 6Z FROM WEST
TO EAST WITH VFR CONDITIONS POSSIBLE BY 15Z IN MOST AREAS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 4 AM EDT THURSDAY FOR KYZ088-118-
120.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...SBH
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
848 PM EDT WED MAR 12 2014
.UPDATE...
ISSUED AT 830 PM EDT WED MAR 12 2014
WIND GUSTS HAVE SLACKENED TO 30 MPH OR LESS AND THUS WE HAVE OPTED TO
CANCEL THE WIND ADVISORY EARLY. MOIST NORTHWEST FLOW IS BRINGING
SNOW SHOWERS TO MUCH OF THE REGION. SOME OF THE RIDGETOPS...PARTICULARLY
THOSE ABOVE 2000 FEET ARE BELOW FREEZING WITH THESE HIGHEST OF
ELEVATIONS NOW IN THE MID AND UPPER 20S. RADAR TRENDS AND THE 18Z NAM
SEEM TO FAVOR THE MOST PERSISTENT SNOW SHOWERS OVER THE FEW HOURS
NEAR OR JUST WEST OF JKL SOUTH INTO HARLAN AND LETCHER COUNTIES. THE
SFC LOW IS NOW CENTERED IN THE VICINITY OF NEW YORK CITY WITH COLDER AND
DRIER AIR ADVECTING SOUTH ON THE WEST SIDE OF THE LOW. AS THE SYSTEM
PULLS ON OFF FURTHER TO THE NORTH AND EAST...AND THE UPPER LEVEL
TROUGH EXITS TO THE EAST OVERNIGHT...SFC HIGH PRESSURE WILL BUILD
TOWARD THE REGION. THIS SHOULD LEAD TO A GRADUAL TAPERING OF THE SNOW
SHOWERS TO FLURRIES LATER ON TONIGHT INTO EARLY ON THURSDAY. AT THIS POINT...
THE INHERITED LOW TEMPERATURES LOOK FINE. HOURLY TEMPERATURE
AND DEWPOINT CURVES AS WELL AS WINDS HAVE BEEN ADJUSTED BASED ON
RECENT TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 315 PM EDT WED MAR 12 2014
18Z SFC ANALYSIS SHOWS THE DEEP LOW NOW OVER SOUTHWESTERN
PENNSYLVANIA WITH ITS COLD FRONT EAST OF KENTUCKY. THIS FRONT WAS
ACCOMPANIED AND TRAILED BY THE HIGHEST WINDS OF THE DAY WITH MANY
GUSTS TO 45 AND 50 MPH REPORTED IN ADDITION TO A 54 MPH GUST AT THE
KNOTT COUNTY MESONET. THE WINDS WILL CONTINUE GUSTY INTO THE EVENING
AS THE COLD AIR CONTINUES TO POUR INTO THIS PART OF THE STATE. THESE
WINDS ARE BRINGING IN THE SOON TO BE SUB FREEZING AIR WITH MID 30S
ALREADY NOTED IN THE NORTHWEST PARTS OF THE AREA WHILE MID 40S HOLD
IN THE FAR EAST...THOUGH BLACK MOUNTAIN IS DOWN TO 38 DEGREES.
DEWPOINTS ARE IN THE LOWER 30S NORTH TO THE UPPER 30S ACROSS THE
SOUTHEAST.
THE UPSLOPE FLOW IS KICKING IN ACROSS THE AREA AND WE CAN SEE THE
RAIN SHOWERS REDEVELOPING THROUGH THE HEART OF THE CWA. SOME FLURRIES
HAVE BEEN REPORTED WITH THESE HERE AT JKL...AND ALSO IN OUR NORTHERN
FRINGES...ON TRACK WITH EXPECTATIONS AND TIMING FROM THE LATEST HRRR.
THIS MODEL ALSO HAS BETTER REDEVELOPMENT OF SNOW TOWARD DUSK. AFTER
REVIEWING THE LATEST MODEL GUIDANCE...AND IN PARTICULAR THE
HRRR...HAVE DECIDED TO HOIST A WINTER WEATHER ADVISORY FOR THREE OF
OUR NORTHERN BORDER COUNTIES WITH VIRGINIA FOR A 1 TO 2 INCH SNOWFALL
MAINLY AT ELEVATIONS ABOVE 2500 FEET.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE DEEP LATE WINTER
TROUGH CROSSING THE OHIO VALLEY TONIGHT. THEY ALL HAVE ENERGY
WRAPPING IN HERE THROUGH 12Z THURSDAY BEFORE THE MASS OF IT PULLS
OFF THE EAST AND HEIGHTS QUICKLY RISE DURING THE DAY THURSDAY. THESE
HEIGHTS FLATTEN OUT LATER THURSDAY NIGHT AS A SHALLOW TROUGH MOVES
THIS WAY FROM THE NORTHERN PLAINS. WITH THIS GOOD AGREEMENT...AND THE
ONGOING WINTER STORM...HAVE LEANED MOST HEAVILY ON THE HIGHER
RESOLUTION NAM12 AND HRRR FOR WEATHER DETAILS.
SENSIBLE WEATHER WILL FEATURE THE UPSLOPE RAIN...CHANGING TO SNOW
LATE THIS AFTERNOON AND EARLY EVENING AND THEN CONTINUING THROUGH
THE EVENING FOR MOST LOCATIONS. THE SNOW WILL LINGER THE LONGEST IN
THE FAR EASTERN PARTS OF THE AREA THROUGH THE MIDDLE OF THE NIGHT.
LOOKING AT AN INCH OR LESS OF ACCUMULATION FOR MOST AREAS...WITH
THOSE HIGHER TOTALS MAINLY ON THE RIDGES. DO EXPECT NEARLY ALL SPOTS
TO GET A DUSTING OF SNOW EVEN IN THE VALLEYS...BUT THE LAG IN THE
COOLING OF THE ROADS SHOULD KEEP THEM MOSTLY CLEAR. THE FAR SOUTHEAST
PARTS OF THE CWA ARE A BIT DIFFERENT...THOUGH...AS THE UPSLOPE WILL
HOLD IN LONGER THERE...TEMPERATURES ARE DROPPING OFF QUICKER IN THE
HIGHER ELEVATIONS...THE HRRR IS HITTING THEM HARDEST WITH QPF...AND
THEY HAVE HIGHER ELEVATION WELL TRAVELED ROADS. FOR THESE REASONS
HAVE ISSUED A WSW FOR HARLAN...LETCHER...AND PIKE COUNTIES THROUGH
4Z...MATCHING UP WITH MRX IN WISE COUNTY.
THE SNOW WILL TAPER TO FLURRIES AND END LATE TONIGHT AND EARLY
THURSDAY MORNING FROM WEST TO EAST. TEMPERATURES WILL BOTTOM OUT IN
THE UPPER TEENS MOST PLACES BY DAWN WITH STILL ENOUGH OF A BREEZE TO
GENERATE WIND CHILLS IN THE SINGLE DIGITS OR NEAR ZERO ON THE HIGHEST
RIDGES. THE LOW CLOUDS WILL CLEAR OUR LATER THURSDAY MORNING WITH
SUNSHINE LIKELY EVAPORATING ANY OF THE SNOW FROM THIS SYSTEM BY MID
AFTERNOON DESPITE TEMPERATURES STRUGGLING TO GET TOO DEEP INTO THE
30S. A PARTLY CLOUDY SKY ON THURSDAY NIGHT WILL SET THE STAGE FOR A
MILDER NIGHT...BUT THIS WILL ALSO REPRESENT A DECENT RIDGE TO VALLEY
TEMPERATURE SPLIT SET UP.
USED A MODIFIED COLDER VERSION OF THE CONSSHORT FOR TEMPS DURING THE
NEXT 24 HOURS AND THEN FAVORED THE NAM12 DIURNAL CURVE WITH ADJUSTED
CONSALL MAX AND MIN T STARTING POINTS THROUGH FRIDAY MORNING. ALSO...
USED THE BCCONSSHORT FOR TD AND WINDS WITH THE CONSALL AFTER THE
FIRST 24 HOURS. THESE WERE MASSAGED FOR THE CURRENT CONDITIONS AND
TRENDS. AS FOR POPS...ENDED UP ON THE HIGH SIDE OF ALL GUIDANCE GIVEN
ITS POOR HISTORY OF PICKING UP ON LOW QPF UPSLOPE SNOW EVENTS.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 325 PM EDT WED MAR 12 2014
SPLIT FLOW PATTERN WILL BE IN PLACE AT THE BEGINNING OF THE LONG
TERM PORTION OF THE FORECAST WITH NEAR ZONAL FLOW ACROSS THE OH AND
TN VALLEYS. AT THE SURFACE HIGH PRESSURE WILL BE TO OUR SOUTHEAST
WITH SOUTHWEST LOW LEVEL FLOW ACROSS OUR AREA. AS A RESULT TEMPERATURES
WILL WARM NICELY WITH MAXIMUM TEMPERATURES ON FRIDAY 20 TO 25
DEGREES WARMER THAN ON THURSDAY.
AS WE MOVE INTO THE WEEKEND A SOUTHERN STREAM SHORT WAVE WILL EMERGE
FROM THE SOUTHERN PLAINS WITH THE ASSOCIATED SURFACE LOW TRACKING
ACROSS THE LOWER MS VALLEY AND THE SOUTHEAST UNITED STATES. AT THE
SAME TIME A NORTHERN STREAM SHORT WAVE WILL BE DROPPING SE FROM THE
NORTHERN PLAINS. THE COMBINED EFFECTS WILL BE TO BRING A CHANCE OF
PRECIPITATION TO THE AREA FOR THE WEEKEND. THERE WILL ONLY BE LOW
CHANCES OF PRECIPITATION ON SATURDAY...WITH PRECIPITATION CHANCES
PEAKING ON SUNDAY. TEMPERATURES WILL BE WARM ENOUGH THAT ANY
PRECIPITATION FROM FRIDAY NIGHT INTO SUNDAY WILL BE IN THE FORM OF
RAIN. ENOUGH COLD AIR LOOKS TO WORK INTO THE AREA ON THE BACKSIDE OF
THE SYSTEM SUNDAY NIGHT INTO EARLY MONDAY MORNING THAT PRECIPITATION
COULD END AS SNOW. THERE IS NOT GOOD MODEL AGREEMENT AT THIS POINT
IN TIME...BUT SOME LIGHT SNOW ACCUMULATION LOOKS POSSIBLE.
THERE IS POOR MODEL AGREEMENT AS WE MOVE INTO NEXT WEEK AND
CONFIDENCE IN THE VARIOUS MODEL SOLUTIONS DECREASES. AFTER A COLD
START TO THE WEEK...TEMPERATURES WILL WARM...BUT THE WHEN AND WHERE
OF THE NEXT SHORT WAVE TO AFFECT THE AREA ARE UNCERTAIN. FOR NOW
WILL KEEP THE WEATHER DRY THROUGH TUESDAY NIGHT...AND BRING A SLIGHT
CHANCE OF SHOWERS INTO THE FAR WESTERN PART OF THE FORECAST AREA ON
WEDNESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 835 PM EDT WED MAR 12 2014
MVFR AND OR IFR CIGS AND OCCASIONALLY VIS WILL AFFECT THE AREA INTO
THE EVENING BEHIND THE COLD FRONT AS AN UPPER LEVEL DISTURBANCE AND
UPSLOPE FLOW COMBINE TO BRING SNOW SHOWERS TO THE REGION. JKL AND
SJS WILL BE MOST AFFECTED BY THE SNOW SHOWERS. WINDS MAY GUST AS
HIGH AS 20 TO 30 KT THROUGH THE 3Z TO 6Z PERIOD BEFORE THE PRESSURE
GRADIENT SLACKENS. CEILINGS WILL GRADUALLY IMPROVE AFTER 6Z FROM WEST
TO EAST WITH VFR CONDITIONS POSSIBLE BY 15Z IN MOST AREAS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 4 AM EDT THURSDAY FOR KYZ088-118-
120.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...SBH
AVIATION...JP
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
725 PM EDT WED MAR 12 2014
.SYNOPSIS...
A VERY STRONG LOW PRESSURE CENTER AND ITS ASSOCIATED COLD FRONT WILL
PASS THROUGH THE MID-ATLANTIC STATES BY THIS EVENING. AN UPPER LEVEL
TROUGH WILL MOVE ACROSS THE AREA TONIGHT...THEN CANADIAN HIGH
PRESSURE WILL BUILD THROUGH THURSDAY NIGHT AND MOVE OFF THE COAST
FRIDAY. ANOTHER WEAK DISTURBANCE MOVES THROUGH TO START THE WEEKEND.
FOR THE SECOND HALF OF THE WEEKEND...HIGH PRESSURE WILL BUILD OVER
THE GREAT LAKES WHILE ANOTHER UPPER DISTURBANCE PASSES THROUGH THE
MID-ATLANTIC.
&&
.NEAR TERM /THROUGH THURSDAY/...
MUCH OF THE SEVERE THUNDERSTORM WATCH WAS CANCELLED WITH THE COLD
FRONT ALREADY PASSING THRU.
A STRONG PRESSURE SURGE BEHIND THE FRONT HAS BEEN ACCOMPANIED BY
WIDESPREAD WIND GUSTS OF GREATER THAN 45 MPH SO FAR. SEVERAL OBS
HAVE BEEN ON THE HIGH END OF WIND ADVISORY...THOUGH ONE PK WND
GUST REACHED HIGH WIND WARNING CRITERIA...MRB OF 61 MPH.
PREVIOUS DISCUSSION...
SEVERE THUNDERSTORM WATCH #28 HAS BEEN ISSUED FOR COUNTIES EAST OF
THE BLUE RIDGE EXCLUDING THE CENTRAL FOOTHILLS...WHERE THE NARROW
LINE OF CONVECTION ALONG THE FRONT HAS ALREADY PASSED THRU. PER
LATEST RADAR TRENDS AND HRRR SIM REFLECTIVITY FORECAST...EXPECT
THIS LINE TO INTENSIFY A BIT OVER THE NEXT COUPLE OF HRS AS IT
REACHES THE I-95 CORRIDOR AND CHESAPEAKE BAY. THE LINE SHOULD
CLEAR THE CHSPK BAY BETWEEN 730 PM AND 830 PM.
983/984 MB SFC LOW IS NOW IN SRN PA AND THIN CONVECTIVE LINE HAS
EVOLVED FROM THAT LOW SWD ACROSS WV...FAR SWRN VA...AND ERN TN.
CLOUDS ARE TRYING TO BREAK AHEAD OF THIS LINE BUT ARE HAVING
TROUBLE AT THE MOMENT NORTH OF THE VA/NC BORDER. EVEN WITH THE
CLOUD COVER...TEMPS AND DEWPOINTS HAVE SURGED...WITH TEMPS IN THE
MID/UPPER 60S AND DEWPOINTS IN THE 50S SOUTH OF THE FRONT. AN
EARLIER WIND SURGE LED TO 40-50 KNOT GUSTS IN LOUDOUN AND
MONTGOMERY COUNTIES...BUT THIS APPEARS TO HAVE SINCE SUBSIDED. THE
FRONT WILL PASS THROUGH THIS EVENING...USHERING IN MARKEDLY COLDER
AIR.
LETS GO THREAT BY THREAT. FIRST...THE STORM THREAT FOR THIS
AFTERNOON. THE LINE WILL CROSS THE CWA BETWEEN 3 PM AND 8 PM. SO FAR
THERE HAS BEEN LITTLE LIGHTNING IN THIS ACTIVITY AND WIND GUSTS HAVE
NOT REALLY BEEN ANY MORE SIGNIFICANT THAN THE GRADIENT WIND.
REGARDLESS...THIS ACTIVITY IS MOVING INTO A SLIGHTLY WARMER
ENVIRONMENT AS IT GETS HERE...SO IT WILL HAVE TO BE MONITORED. AND
AS WE HAVE SEEN...THE WINDS ARE STRONG ENOUGH ALREADY AS IT IS.
NEXT IS THE WIND THREAT. A WIND ADVISORY STARTS AT 6 PM AND HAS BEEN
EXPANDED TO INCLUDE THE ENTIRE FORECAST AREA. WINDS ARE ALREADY
WIDESPREAD GUSTING TO 25 TO 35 KNOTS AND THIS WILL PICK UP EVEN
FURTHER SINCE THE PRESSURE GRADIENT IS ACTUALLY STRONGER BEHIND THE
FRONT. SOME OF THE GUIDANCE INDICATES WIND GUSTS EXCEEDING 50 KNOTS
THIS EVENING...ESPECIALLY AT HIGHER ELEVATIONS. THEREFORE...THE
POTENTIAL FOR A SHORT-LEAD-TIME UPGRADE TO HIGH WIND WARNING DOES
EXIST BEHIND THE FRONT. WINDS WILL STAY QUITE GUSTY THROUGH THE
MORNING HOURS ON THURSDAY AND THEN VERY GRADUALLY SUBSIDE DURING THE
AFTERNOON.
SHARPLY COLDER TEMPERATURES AND WIND CHILLS ARE ANOTHER THREAT.
TEMPS SHOULD DROP 30-40 DEGREES IN ABOUT FOUR HOURS AS THE FRONT
PASSES...WITH LOWS TONIGHT RANGING FROM THE SINGLE DIGITS IN THE
HIGHLANDS...TO 20-25 EAST OF THE BLUE RIDGE. BETWEEN A LACK OF
RAIN...AND PLENTY OF WIND...THERE PROBABLY WILL NOT BE MUCH IN THE
WAY OF ICING PROBLEMS FOR THE MORNING COMMUTE. WIND CHILLS WILL BE
NO HIGHER THAN THE SINGLE DIGITS AREAWIDE...AND BELOW ZERO IN MANY
LOCATIONS IN THE HIGHLANDS AND NORTHERN MARYLAND. WIND CHILLS COULD
APPROACH 20 BELOW ZERO IN SPOTS IN THE HIGHLANDS. TEMPERATURES WILL
REMAIN NEAR OR BELOW FREEZING IN MOST AREAS ON THURSDAY.
UPSLOPE SNOW WILL DEVELOP WEST OF THE ALLEGHENY FRONT THIS EVENING
AND CONTINUE THROUGH MUCH OF THE NIGHT. CURRENT THINKING IS MAYBE A
COUPLE OF INCHES OF SNOW...BUT THAT AMOUNT COULD VARY GREATLY
DEPENDING ON THE LENGTH OF TIME SNOW OCCURS AND HOW QUICKLY TEMPS
FALL BELOW FREEZING BEHIND THE FRONT. A WINTER WEATHER ADVISORY
CANNOT BE RULED OUT FOR THESE AREAS. ELSEWHERE...SNOW CHANCES APPEAR
SMALL...IF ANY.
FOR DETAILS ON THE MARINE/COASTAL FLOOD/FIRE WEATHER THREATS...SEE
THEIR RESPECTIVE SECTIONS OF THIS DISCUSSION.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY/...
WINDS WILL DIMINISH THURSDAY EVENING AS HIGH PRESSURE MOVES
OVERHEAD. THE LIGHTER WINDS AND A MOSTLY CLEAR SKY SHOULD ALLOW
TEMPERATURES TO PLUMMET THURSDAY EVENING...WITH OVERNIGHT LOWS
GENERALLY AROUND 20 EXPECTED...EXCEPT 20 TO 25 IN THE INNER CITIES.
MILDER WEATHER IS EXPECTED FRIDAY AS COLD HIGH PRESSURE DEPARTS TO
THE EAST AND SOUTHERLY RETURN FLOW SETS UP. HIGHS IN THE 50S TO NEAR
60 ARE EXPECTED.
A COLD FRONT WILL APPROACH THE AREA FROM THE GREAT LAKES FRIDAY
NIGHT INTO SATURDAY...BUT AT THIS TIME DOES NOT APPEAR TO HAVE MUCH
MOISTURE WITH IT. THE BEST CHANCE OF PRECIPITATION WILL BE OVER THE
POTOMAC HIGHLANDS WHERE A FEW RAIN OR SNOW SHOWERS ARE POSSIBLE.
COLDER AIR LAGS BEHIND THE FRONT...SO SATURDAY SHOULD BE ANOTHER
MILD DAY WITH HIGH TEMPERATURES SIMILAR TO THAT OBSERVED ON FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
SUNDAY WILL LIKELY BE THE NICEST DAY OF THE LONG TERM PERIOD WITH
HIGH TEMPS NEAR 50 DEGREES...NEAR NORMAL FOR THIS TIME OF YEAR...AND
PARTLY SUNNY SKIES. HIGH PRESSURE OVER THE GREAT LAKES WILL KEEP
LIGHT WINDS OUT OF THE NORTH DURING THE DAY. THE FRONTAL BOUNDARY
THAT CROSSED OUR AREA SATURDAY WILL STALL OFF OF THE EAST COAST
SUNDAY NIGHT AND MODAL AGREEMENT IS VERY LOW ON WHAT WILL HAPPEN
NEXT.
UPPER LEVEL TROUGHING OVER THE GREAT LAKES SHOULD ENCOURAGE THE
FORMATION OF A LOW PRESSURE WAVE ALONG THE STALLED BOUNDARY OVER THE
GULF COAST. THIS WAVE SHOULD MOVE UP THE EAST COAST AS THE UPPER
LEVEL TROUGH LIFTS THROUGH THE BEGINNING OF THE WORKWEEK. TRACK AND
TIMING OF THIS COASTAL LOW IS STILL VERY UNCERTAIN...AS THERE IS
VERY HIGH VARIABILITY WITHIN ENSEMBLE MEMBERS OF GLOBAL MODELS.
TRACK WILL PLAY A LARGE ROLL IN PTYPE AND LOCAL IMPACTS. ASSUMING
THAT LOW TRACKS UP THE COAST AND WE REMAIN IN THE COLD SECTOR OF THE
STORM...WINTRY PRECIP IS A REALISTIC EXPECTATION. HAVE FORECAST
HIGHS NEAR 40 AND LOWS IN THE UPPER 20S FOR NEXT WEEK WITH LOW END
CHANCE POPS THROUGH THE ENTIRE BEGINNING OF THE WORKWEEK. HAVE
STARTED PTYPE AS RAIN AND INCLUDED POSSIBILITY OF SNOW OVERNIGHT
MONDAY TO ACCOUNT FOR UNCERTAINTY OF LOW TRACK AND DYNAMICS.
&&
.AVIATION /23Z WEDNESDAY THROUGH MONDAY/...
THIN LINE OF SHRA/POSSIBLE TSRA WILL MOVE THROUGH THE TERMINALS
BETWEEN 20 UTC AND 23 UTC. RELATIVELY BRIEF VSBY/CIG RESTRICTIONS
ARE LIKELY AS THIS LINE PASSES. BIG STORY FOR AVIATION WILL BE THE
GUSTY AND PERSISTENT WIND. WINDS OUT OF THE SOUTH WILL SHIFT OUT OF
THE WEST AND THEN NORTHWEST AS THE FRONT PASSES...AND LIKELY BECOME
EVEN GUSTIER THAN THEY HAVE BEEN. WIND GUSTS OVER 40 KTS ARE LIKELY
AT TIMES. WINDS WILL GRADUALLY SUBSIDE ON THURSDAY. ASIDE FROM THE
CONVECTIVE LINE...VFR CIGS/VSBYS ARE EXPECTED.
VFR CONDITIONS ARE EXPECTED THURSDAY NIGHT THROUGH SATURDAY...WITH
THE EXCEPTION OF TERMINALS OVER THE POTOMAC HIGHLANDS WHERE SUB-VFR
CONDITIONS ARE POSSIBLE IN RAIN OR SNOW SHOWERS. GUSTY NORTHWEST
WINDS OF 15 TO 20 KNOTS WITH GUSTS TO 25 KNOTS ARE EXPECTED THURSDAY
EVENING...BECOMING LIGHT AND VARIABLE AFTER MIDNIGHT. SOUTHERLY
WINDS AROUND 10 KNOTS ARE EXPECTED FRIDAY INTO FRIDAY NIGHT WITH
GUSTS TO 20 KNOTS POSSIBLE. WINDS THEN BECOME WEST AROUND 10 KNOTS
SATURDAY.
&&
.MARINE...
EXPANDED THE GALE WARNING TO ALL WATERS...STARTING EARLIER AND
ENDING LATER. GUSTS OVER 30 KNOTS ARE ALREADY HAPPENING AND WILL
CONTINUE AND EVEN INTENSIFY AS THE FRONT PASSES. GALE-LEVEL GUSTS
WILL CONTINUE THROUGH MOST OF THURSDAY...ESPECIALLY OVER THE MORE
OPEN WATERS OF THE LOWER TIDAL POTOMAC AND MARYLAND CHESAPEAKE BAY.
WINDS WILL GRADUALLY SUBSIDE DURING THE LATE AFTERNOON THURSDAY.
SCA CONDITIONS ARE EXPECTED THURSDAY EVENING IN A GUSTY NORTHWEST
FLOW. A BRIEF LULL IN WINDS IS FORECAST THROUGH FRIDAY
MORNING...WITH GUSTY SOUTHERLY FLOW BRINGING ANOTHER ROUND OF SCA
WINDS FRIDAY AFTERNOON AND EVENING...BEFORE WINDS SLACKEN OFF
OVERNIGHT FRIDAY NIGHT INTO SATURDAY MORNING.
A SMALL CRAFT ADVISORY MAY BE NECESSARY BEGINNING SUNDAY NIGHT AS
A COASTAL LOW MAY MOVE NEAR THE AREA.
&&
.FIRE WEATHER...
ABUNDANTLY DRY AIR WILL ACCOMPANY THE ARCTIC AIRMASS INVADING THE
AREA ON THURSDAY...WITH DEW POINTS BELOW ZERO EXPECTED. THIS WILL
RESULT IN RELATIVE HUMIDITY VALUES BOTTOMING OUT AT 20 TO 25 PERCENT
THURSDAY AFTERNOON...ESPECIALLY EAST OF THE BLUE RIDGE. THE DRY AND
WINDY CONDITIONS MAY RESULT IN AN ENHANCED FIRE SPREAD POTENTIAL. A
FIRE WEATHER WATCH HAS BEEN ISSUED FOR ALL OUR VIRGINIA COUNTIES
EAST OF THE BLUE RIDGE IN COORDINATION WITH NEIGHBORING OFFICES AND
FIRE OFFICIALS. THE REMAINDER OF THE AREA WILL BE FURTHER CONSIDERED
FOR SPS AND POTENTIAL FIRE WEATHER HEADLINES TONIGHT OR TOMORROW.
&&
.TIDES/COASTAL FLOODING...
COASTAL FLOOD ADVISORY HAS EXPIRED. WITH THE ANNAPOLIS BUOY
REMAINING JUST BELOW THRESHOLD DURING THE AFTN HIGH TIDE... COASTAL
FLOODING ELSEWHERE UNLIKELY.
WATER LEVELS WILL SHARPLY DECREASE FOLLOWING FRONTAL PASSAGE...AND
A NEGATIVE ANOMALY OVER ONE FOOT IS LIKELY BY THURSDAY AFTERNOON.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WIND ADVISORY UNTIL 11 AM EDT THURSDAY FOR DCZ001.
MD...WIND ADVISORY UNTIL 11 AM EDT THURSDAY FOR MDZ003>007-009>011-
013-014-016>018-501-502.
WIND CHILL ADVISORY FROM 11 PM THIS EVENING TO NOON EDT
THURSDAY FOR MDZ501-502.
VA...WIND ADVISORY UNTIL 11 AM EDT THURSDAY FOR VAZ025>031-036>040-
042-050>057-501>504.
WIND CHILL ADVISORY FROM 11 PM THIS EVENING TO NOON EDT
THURSDAY FOR VAZ503-504.
FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
AFTERNOON FOR VAZ036>040-042-050>057-501-502.
WV...WIND ADVISORY UNTIL 11 AM EDT THURSDAY FOR WVZ050>053-055-
501>506.
WIND CHILL ADVISORY FROM 11 PM THIS EVENING TO NOON EDT
THURSDAY FOR WVZ501>506.
MARINE...GALE WARNING UNTIL 8 PM EDT THURSDAY FOR ANZ530>534-537>543.
SMALL CRAFT ADVISORY FROM 11 AM TO 8 PM EDT THURSDAY FOR
ANZ535-536.
GALE WARNING UNTIL 11 AM EDT THURSDAY FOR ANZ535-536.
&&
$$
UPDATE...JRK
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1033 AM EDT TUE MAR 11 2014
.SYNOPSIS...
HIGH PRESSURE WILL PERSIST OVER THE SOUTHEASTERN STATES TODAY AS
LOW PRESSURE MOVES EAST ACROSS QUEBEC. STRONG LOW PRESSURE AND ITS
ASSOCIATED COLD FRONT WILL PASS THROUGH LATER WEDNESDAY INTO
WEDNESDAY NIGHT. HIGH PRESSURE WILL BUILD OVERHEAD THURSDAY BEFORE
MOVING OFF THE COAST FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
MRNG SFC ANALYSIS SHOWS HIPRES SITUATED EAST OF THE FL COAST WHILE
UPSTREAM LOPRES IS LOCATED OVER KANSAS. A DIFFUSE FRONTAL BOUNDARY
HAS BEEN STATIONARY FROM THE NRN MID-ATLANTIC STATES AND EXTENDS
WESTWARD BACK TOWARD THE CENTRAL PLAINS LOW. SWLY FLOW AHEAD OF
THE LOW AND ON THE BACKSIDE OF THE HIGH WILL DRAW WARMER AIR INTO
THE MID-ATLANTIC STATES THRU TNGT.
FOR THE SECOND CONSECUTIVE DAY...OROGRAPHIC MID AND HI CLOUDS
DEVELOPED TO THE LEE OF THE ALLEGHENY FRONT OVNGT AND CONTINUED
INTO THE MRNG. THE BIG QUESTION REMAINS HOW QUICKLY THESE CLOUDS
WILL DISSIPATE. LATEST RAP SHOWS MOISTURE AND WEAK ISENTROPIC LIFT IN
THE 700-400 MB LAYER PERSISTING THRU AT LEAST MID AFTN...THOUGH
DRIER AIR MAY ERODE CLOUDS IN CENTRAL VA AND SRN MD DURING THIS
TIME. FCST WAS UPDATED TO HOLD ON TO THESE MT WAVE CLOUDS LONGER
INTO THE AFTN...PARTICULARLY ACROSS THE NRN HALF OF THE CWA.
WHILE CLOUDS WILL LIMIT HEATING...DID NOT WANT TO LOWER MAX TEMP
FCST TOO MUCH WITH THE ALREADY WARM START TO THE DAY AND GIVEN
THAT EVEN A COUPLE OF HRS OF SUNSHINE LATER IN THE DAY WILL MIX
OUT THE SHALLOW NOCTURNAL BOUNDARY LAYER EVIDENT ON THE 12Z IAD
RAOB...RESULTING IN A QUICK JUMP IN TEMPS.
SFC BOUNDARY IS FCST TO STALL CLOSE TO THE POTOMAC RIVER TNGT. LGT
SELY FLOW SOUTH OF THE BOUNDARY WILL BE ACCOMPANIED BY MILDER
OVNGT TEMPS WHILE ELY ALONG AND COOLER CONDITIONS RESIDE ALONG AND
NORTH OF THE BOUNDARY. PRE-FRONTAL PRECIP IS EXPTECTED TO STAY
WEST OF THE AREA BEFORE SUNRISE WED.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
MIDWEEK SYSTEM FOR CWFA LOOKING INCRSGLY WARM AND CNVCTV...AS MDL
CONSENSUS TAKES TRACK OF SFC LOW N OF CWFA. /NAM STILL APPEARS TO BE
AN OUTLIER AND WAS NOT USED./ THEREFORE...AREA WL BE W/IN WM SECTOR
OF SYSTEM WED AS CDFNT ENTERS DURING PK HTG...WITH ALL THAT ENTAILS.
SFC LOW WL HV STRONG ASSOCD DYNAMICS...IN TERMS OF S/WV ENERGY...A
VIGOROUS WIND FIELD...AND BAROCLINICITY. SFC SYSTEM WL HV LIFT FM
RRQ NRN STREAM AND LFQ SRN STREAM UPR JETS. PLUS...A RAPID DROP IN
H5 HGTS WL ADD TO THE POTENCY OF THE ENVIRONMENT. THESE FACTORS WL
SUPPORT A STRENGTHENING LOW...WHICH WL BE NEAREST PTMC HIGHLANDS
NEAR 18Z.
AM THINKING THAT THERE WL BE AMPLE CLDCVR DURING THE MRNG...BUT ANY
BREAKS CUD LEAD TO INSTBY DUE TO AFTN DEWPTS INTO THE LWR 50S. GFS
PROGS A FEW HND JOULES OF CAPE BY THIS TIME...AS CDFNT/HGT FALLS
ENTER THE SCENE. THINK THAT THERE WL BE ENUF GOING FOR UPDRAFTS TO
DVLP...AND CANNOT PRECLUDE A MORE CONCENTRATED LINE OF SHRA/TSRA
/INSTEAD OF A MORE WIDESPREAD OCNL SHRA SITUATION/. WNDS BY THIS PT
ON THE ORDER OF 40-50 KT...WHICH CUD BE TRANSPORTED TO THE SFC IN
ANY SHRA/STORM. THEREFORE FEEL THAT THERES A RISK OF DMGG WND GUSTS.
ALREADY HV CHC TSRA IN GRIDS AND SVR RISK IN HWO. RAISED MAXT CLSR
TO 70F DC SWD IN RESPONSE TO WAA AHD OF FNT.
A RAPID DROP IN TEMPS IS STILL XPCTD WED NGT IN THE WAKE OF THE
FROPA. LTST INDICATIONS ARE THAT PCPN WL DEPART FIRST ACRS MUCH OF
THE AREA. THE STORY WL BE DIFF FOR THE WRN SLOPES OF THE APLCNS. HV
KEPT CAT POPS FOR OCNL SHSN. DONT BELIEVE SNW WL BE A BIG IMPACT
EVEN THERE.
THE BIGGER STORY WED NGT INTO THU MRNG WL BE THE WND FIELD AND
TEMPS...AS STRONG CAA WL SUPPORT MIXING OF 45 KT W/IN BNDRY LYR. HV
ONCE AGN BOOSTED WNDS IN THE GRIDS. SUSPECT A WND ADVY WL BE NCSRY
AT SOME PT...ALTHO PERHAPS NOT FOR THE ENTIRE CWFA. MOS CONSISTENT
W/ MIN-T THU MRNG IN THE TEENS AND 20S...MEANING ACTUAL TEMP DROPS
OF 40-50F-- AND THATS NOT FACTORING IN WND CHILL. ON TOP OF THE SNW
FOR THE MTNS...WND CHILL VALUES APPROACHING ADVY LVLS AS WELL.
IMPACT OF CAA IN FULL EFFECT THU. MAXT BEEN FAIRLY CONSISTENT FOR A
CPL CYCLES...SUGGESTING IT/LL BE A STRUGGLE TO RISE ABV FRZG ACRS
NRN MD AND W OF THE SHEN VLY. DO THINK THAT THE DOWNSLOPING FLOW WL
RIP APART ANY CLD DECK...SO WL HV AMPLE BUT INEFFECTUAL SUNSHN. ON
THE WRN SLOPES...SAME BASIC THEME AS HIPRES BLDS...BUT THE CLRG WL
BE A LTL DELAYED. STILL HV PTSUN AND A CHC SHSN FOR THE MRNG.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
SUNNY SKIES WILL ALLOW TEMPERATURES TO REBOUND NICELY FRIDAY FROM
LOWS IN THE LOWER TO MID 20S IN THE MORNING TO HIGHS IN THE 50S
DURING THE DAYTIME AS HIGH PRESSURE OVER THE SOUTHEASTERN US
STRETCHES UP INTO OUR AREA. SOUTHWEST FLOW WILL FILL IN AS THE HIGH
MOVES OFF THE CAROLINA COAST FRIDAY EVENING. LOWS SATURDAY MORNING
WILL BE IN THE 30S AND HIGH TEMPS ON SATURDAY AFTERNOON SHOULD REACH
INTO THE UPPER 50S TO LOWER 60S.
LOW PRESSURE LOCATED NORTH OF THE GREAT LAKES WILL CAUSE A WEAK COLD
FRONT TO SWING THROUGH THE MID ATLANTIC SATURDAY NIGHT. ASIDE FROM
SOME LIGHT PRECIP WEST OF THE BLUE RIDGE...LOCAL IMPACTS SHOULD BE
LIMITED TO INCREASED CLOUD COVER SATURDAY AFTERNOON AND A HIGH
TEMPERATURE ON SUNDAY IN THE LOWER 50S...5 TO 10 DEGREES COOLER THAN
THE HIGH ON SATURDAY.
AN UPPER LEVEL DISTURBANCE WILL APPROACH THE AREA OVERNIGHT
SUNDAY...BRINGING OUR BEST CHANCES OF PRECIP IN THE PERIOD. STILL
PLENTY OF UNCERTAINTY IN THE FORECAST...BUT A WINTRY MIX IS POSSIBLE
FOR SOME LOCATIONS IN THE EARLY MORNING HOURS ON MONDAY BEFORE PTYPE
SHOULD SWITCH OVER TO LIGHT RAIN FOR THE REST OF THE MORNING. COOL
AIR WILL FILL IN ONCE AGAIN BEHIND THIS FRONT AND HIGH TEMPERATURES
ON MONDAY WILL ONLY GET INTO THE 40S.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS TDA AND TNGT. LGT SWLY WINDS TDA WILL BECOME E/SE
TNGT.
FLGT RESTRICTIONS /MVFR-IFR/ LKLY WED...MAINLY AFTN-EVE...IN
RESPONSE TO LOPRES TRACKING N OF TERMINALS DRAGGING A CDFNT THRU. A
PROLONGED PD OF RESTRICTIONS LOOKING LESS LKLY THO...AS PCPN WL BE
SHOWERY IN NATURE. LWS ALSO LKLY BOTH AHD OF AND BHD FNT...AS 40-50
KT OF WND WL BE PRESENT 2000-3000 FT OFF THE GRND.
WINDY CONDS /NW 20G35-40KT/ WL CONT INTO THU...BUT WL GRDLY SUBSIDE
THRU THE AFTN. OTRW...VFR SHUD PREVAIL INTO THE WKND.
&&
.MARINE...
LGT WINDS TDA. WINDS BECOME SELY LATE TONIGHT. WIND GUSTS
APPROACH SCA CRITERIA CLOSE TO 12Z OVER THE MID CHSPK BAY BUT HAVE
CAPPED IT AT 15 KT AT THIS TIME WITH SUCH A MARGINAL SETUP.
SLY FLOW WL INCR WED AHD OF CDFNT. HV RAISED SCA FOR THE TIME BEING
DURING THE AFTN FOR ALL WATERS. HWVR...BEST RISK OF WNDS MIXING TO
SFC WL BE IN ASSOCIATION W/ CNVCTN...WHICH MAY REQUUIRE SMW/S
INSTEAD.
ONCE THE CDFNT CROSSES THE MARINE AREA WED NGT...WNDS WL VEER NWLY
AND PICK UP SGFNTLY. GDNC STILL SUGGESTING THAT GLW LKLY WED NGT...
LASTING INTO THU. BYD THAT...RAMP DOWN SCA CONDS XPCTD INTO FRI AS
HIPRES BLDS.
&&
.TIDES/COASTAL FLOODING...
TIDAL DEPARTURES ALREADY UP TO A FT ABV NORMAL. ELEVATED WATER LVLS
SHUD CONT THRU THE DAY TODAY...BUT SEE NO REASON WHY INCREASES SHUD
WIDEN. MDL GDNC CONCURS.
THE BEST PUSH OF SLY FLOW COMES WED...ESPECIALLY DURING THE MIDDAY
AND AFTN AHD OF A STRONG CDFNT. WHILE THE HIGHER OF THE TWO TIDE
CYCLES COMES AT NIGHT...THE DIFFERENCE IS ONLY A MATTER OF INCHES.
WOULD THINK THAT THE PM CYCLE WOULD STILL HAVE A HIGHER RISK...DUE
TO WHEN THE PUSH OF SLY FLOW ARRIVES. BEST ESTIMATE IS THAT MINOR
INUNDATION MAY RESULT.
EXPECT A BLOW OUT TO OCCUR WED NGT...BUT AM UNSURE HOW IT WL
INTERACT/BE TIMED COMPARED TO THE INCOMING TIDE CYCLE. REGARDLESS...
ONCE THE WED NGT TIDE PULLS OUT...WATER SHUD BE DRIVEN OUT...AND WL
BE TALKING ABOUT NEGATIVE WATER LVL DEPARTURES BY THU.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TO 6 PM EDT WEDNESDAY FOR
ANZ530>543.
&&
$$
SYNOPSIS...HTS
NEAR TERM...JRK
SHORT TERM...HTS
LONG TERM...CEB
AVIATION...JRK/HTS
MARINE...JRK/HTS
TIDES/COASTAL FLOODING...HTS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
110 PM EDT TUE MAR 11 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 509 AM EDT TUE MAR 11 2014
WV IMAGERY AND RUC ANALYSIS INDICATED MAINLY ZONAL MID/UPPER LEVEL
FLOW FROM THE NRN PLAINS THROUGH THE NE CONUS. A SHORTWAVE TROUGH
OVER NRN MANITOBA ON THE LEADING EDGE OF VERY COLD ARCTIC AIR IS
EXPECTED TO SLIDE TO THE SE AS A RIDGE BUILDS INTO WRN CANADA.
ANOTHER SHRTWV OVER SASK IS ALSO EXPECTED TO DIVE TOWARD THE UPPER
MS VALLEY AS THE PATTERN AMPLIFIES. AT THE SFC...A COLD FRONT
TRAILING LOW PRES OVER QUEBEC EXTENDED THROUGH NRN ONTARIO INTO SRN
MANITOBA. TO THE SOUTH...MILD CONDITIONS PREVAILED WITH READINGS
REMAINING IN THE UPPER 30S TO AROUND 40 FROM NRN MN AND NRN WI
THROUGH UPPER MI. EXTENSIVE MID/HIGH CLOUDS HAVE ALSO LIMITED
RADIATIONAL COOLING.
TODAY...THE COLD FRONT IS EXPECTED TO MOVE THROUGH LAKE SUPERIOR AND
UPPER MICHIGAN THIS MORNING BRINGING AN INITIAL INFLUX OF COLDER
AIR. SO...MAX DAYTIME READINGS ARE EXPECTED EARLY WITH TEMPS STEADY
OR SLOWLY FALLING DURING THE AFTERNOON. AS LOW LEVEL MOISTURE NORTH
OF LAKE SUPERIOR MOVES IN AND 850 MB TEMPS FALL TO AROUND -13C BY
00Z/WED...SOME LIGHT SNOW SHOWERS OR FLURRIES MAY BE POSSIBLE LATE
OVER THE NORTH AND WEST PORTIONS OF THE CWA.
TONIGHT...AS THE SASK SHRTWV MOVES TOWARD THE AREA MUCH COLDER
ARCTIC AIR WILL PUSH INTO THE REGION WITH 925 MB TEMPS DROPPING TO
AROUND -21C AND INCREASING WINDS VEERING FROM THE FROM THE NNW TO
NE. A PERIOD OF DEEPER MOISTURE ALONG WITH THE LOW LEVEL
INSTABILITY WILL FAVOR SOME LES FOR LOCATIONS DOWNWIND OF LAKE
SUPERIOR...ESPECIALLY WHERE UPSLOPE FLOW IS MAXIMIZED.
THE POSITION OF THE DGZ WILL ALSO BE MOST FAVORABLE FROM 06Z-12Z/WED.
SATELLITE IMAGERY FROM MON SHOWED ENOUGH BREAKS IN THE ICE COVER FOR
AT LEAST SOME HEAT/MOISTURE FLUX FROM THE LAKE TO SUPPORT LES. SINCE
THE ICE WILL STILL SIGNIFICANTLY REDUCE THE LES POTENTIAL...EXPECT
SNOWFALL AMOUNTS ONLY IN THE 1 TO 2 INCH RANGE...GREATEST OVER THE
HIGHER TERRAIN OF N CNTRL UPPER MI. THE NE WINDS WILL BE LESS
FAVORABLE FOR SNOW AT IWD...WITH THE HIGHER CHANCES/AMOUNTS FARTHER
TO THE WEST...OR FOR THE KEWEENAW WHERE LOW LEVEL CONV WILL BE MINIMAL.
OTHERWISE...THE MUCH COLDER AIR WITH LOWS NEAR ZERO AND WINDS OF 10
TO 20 MPH WILL PRODUCE WIND CHILLS FROM -10 TO -20 LATE TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 343 AM EDT TUE MAR 11 2014
HIGH PRESSURE OVER NORTHWEST ONTARIO WILL LEAD TO NORTHEAST LOW
LEVEL FLOW OVER THE UPPER GREAT LAKES REGION TO START THE
LONG TERM PERIOD. THIS NORTHEAST FLOW WILL BE PRODUCING UPSLOPE SNOW
SHOWERS ESPECIALLY IN NORTH CENTRAL UPPER MICHIGAN TONIGHT AND
EXPECT THOSE TO CONTINUE INTO WEDNESDAY. ALTHOUGH WINDS HAVE CREATED
SOME GAPS IN THE ICE NEAR THE SOUTHERN SHORELINE OF CENTRAL/EASTERN
LAKE SUPERIOR...NOT THINKING THAT THERE WILL BE TOO MUCH ASSISTANCE
TO THE UPSLOPE SNOW SHOWERS EVEN THOUGH 900MB TEMPS WILL BE AROUND
-22C. WITH INVERSION HEIGHTS ONLY AROUND 3-4KFT...WOULDN/T EXPECT
THE SNOW SHOWERS TO BE TOO STRONG AND ANY ADDITIONAL ACCUMULATIONS
SHOULD BE LIGHT WITH THE CLOUD BEING ABOVE THE DGZ. DID SLOWLY
DIMINISH THE SNOW SHOWER CHANCES THROUGH THE DAY AS THE MOISTURE
DEPTH BECOMES SHALLOW AND WINDS BACK TO THE NORTH-NORTHWEST. WITH
THE MODELS SHOWING THE MOISTURE REMAINING BELOW THE STRENGTHENING
INVERSION FROM THE HIGH MOVING OVER THE UPPER GREAT
LAKES...WONDERING IF CLOUDS WILL HOLD OVER THE AREA INTO THE
AFTERNOON (ESPECIALLY OVER THE NORTH CENTRAL). THE NORTHERLY WINDS
AND CLOUDS WILL LEAD TO A VERY COLD DAY ACROSS UPPER MICHIGAN...WITH
HIGHS IN THE UPPER SINGLE DIGITS TO MID TEENS.
STILL LOOKS TO BE A VERY COLD NIGHT ON WEDNESDAY NIGHT AS THE HIGH
SHIFTS SOUTHEAST ACROSS THE CWA. WILL CONTINUE TO SHOW THE COLDEST
VALUES OF -10F TO -18F OVER THE EAST HALF OF THE CWA AND THE SINGLE
DIGITS BELOW ZERO OVER THE WEST HALF. WOULD EXPECT THE TEMPERATURES
TO WARM OVER THE WEST TOWARDS MORNING AS RETURN FLOW DEVELOPS AND
MID CLOUDS BEGINNING TO MOVE IN UNDER WAA AHEAD OF THE NEXT CLIPPER
SYSTEM. GEM/ECMWF/NAM CONSISTENT ON SOME LIGHT PRECIPITATION MOVING
INTO THE WESTERN U.P. WITH THIS WAA ON THURSDAY MORNING. SINCE
THERE HAVE BEEN INDICATIONS OF THIS OVER THE LAST COUPLE OF
DAYS...WILL TREND VALUES UP TO CHANCES AND THEN DIMINISH THEM AS
THEY HEAD EAST OVER THE REST OF THE CWA DURING THE AFTERNOON. WHILE
EARLIER RUNS WERE INDICATING A LACK OF ICE CRYSTALS FOR THIS
PRECIPITATION...IT NOW APPEARS THAT THERE WILL BE ENOUGH MOISTURE
IN THE ICE CRYSTAL AREA TO SUPPORT ALL SNOW. AT THIS POINT...MIGHT
SEE UP TO A HALF INCH TOWARDS IRONWOOD AND THEN DIMINISHING AMOUNTS
HEADING EAST.
BEHIND THIS PRECIPITATION...FOCUS TURNS TO THE LOW CENTERED NEAR
LAKE WINNIPEG AT 18Z THURSDAY. THIS LOW WILL TRACK SOUTHEAST
THROUGH THE UPPER GREAT LAKES REGION LATE THURSDAY NIGHT INTO
FRIDAY. MODELS STILL DIFFERING ON THE SHORTWAVE...WHICH IS NOW
WELL OVER THE PACIFIC...WHICH IN-TURN CONTROLS THE TRACK OF THE LOW.
GFS HAS CONSISTENTLY BEEN THE FARTHEST NORTH (ALONG WITH RECENT RUNS
OF THE UKMET) AND RUNNING THE LOW ALONG THE NORTH SHORE OF LAKE
SUPERIOR...WHILE THE ECMWF TRACKS THE LOW ALONG THE SOUTH SHORE. THE
GEM HAS BEEN BOUNCING BETWEEN THE TWO OVER THE LAST COUPLE DAYS. ALL
IN ALL...THESE DIFFERENCES WON/T HAVE TOO MUCH OF AN AFFECT ON THE
LAND CWA PRECIPITATION...SINCE THE WAA PRECIP WILL BE OVER NORTHEAST
LAKE SUPERIOR AND ONTARIO THURSDAY NIGHT. UNFORTUNATELY FOR THOSE
LOOKING FOR ANOTHER REALLY WARM DAY...IT APPEARS THAT THE WARM AIR
ALOFT WILL MOVE THROUGH ON THURSDAY NIGHT AND THEN AREA WILL SEE
COLDER AIR MOVING IN THROUGH THE DAY. THUS...EXPECT THE WARMEST
TEMPS ON FRIDAY TO BE NEAR LAKE MICHIGAN AND IN THE UPPER 30S TO
AROUND 40.
WITH THE DIFFERENCES IN THE TRACK OF THE LOW...THERE ARE ALSO
DIFFERENCES IN THE ARRIVAL OF THE SECONDARY COLD FRONT AND
NORTHERLY WINDS. COULD BE A LITTLE BREEZY OUT OF THE WEST ON
FRIDAY BEFORE THIS ARRIVES...WITH WINDS TURNING TO THE NORTHWEST AND
EVENTUALLY NORTHERLY ON FRIDAY NIGHT. EXPECT SOME PRECIPITATION
ASSOCIATED WITH THIS COLD SURGE AND WITH SOME GAPS STARTING TO SHOW
IN THE ICE NEAR THE APOSTLE ISLANDS...THERE COULD EVEN BE SOME LAKE
ENHANCED/EFFECT SNOW FRIDAY NIGHT INTO SATURDAY. DIFFICULT TO GO
WITH MUCH MORE THAN SLIGHT/CHANCE POPS WITH THE AMOUNT OF ICE COVER
AND POTENTIAL CHANGES OVER THE NEXT SEVERAL DAYS...SO WILL FOLLOW A
SIMILAR IDEA AS THE PREVIOUS SHIFT. THAT PUTS CHANCES OVER THE
FAVORED NORTHWEST AREAS IN THE WEST ON FRIDAY NIGHT AND THEN
TRANSITION TO TRADITIONAL NORTHWEST-NORTHERLY WIND AREAS FOR
SATURDAY. WITH A HIGH PRESSURE RIDGE NOSING SOUTH FROM ONTARIO ON
SATURDAY NIGHT AND SUNDAY...EXPECT DRIER AIR TO MOVE IN AND HAVE
DIMINISHED POPS HEADING INTO SUNDAY (EVENTHOUGH 850MB TEMPS REMAIN
AROUND -17C). WITH THE COLD TEMPS ALOFT...SHOULD BE 10-20 DEGREES
BELOW NORMAL FOR HIGHS THIS WEEKEND. DEPENDING ON HOW QUICKLY SKIES
CLEAR OUT ON SATURDAY NIGHT...THERE IS THE POTENTIAL FOR SUB ZERO
LOWS OVER MUCH OF THE AREA AND HAVE TRENDED VALUES DOWN A COUPLE
DEGREES. THE COLDEST NIGHT WILL BE SUNDAY NIGHT AS THE AREA OF HIGH
PRESSURE MOVES OVER THE CWA. SINGLE DIGITS BELOW ZERO SEEMS LIKE A
GOOD START AT THIS POINT...BUT WOULDN/T BE SURPRISED TO SEE SOME
COLD SPOTS IN THE TEENS BELOW ZERO. THE HIGH IS EXPECTED TO SHIFT
EAST ON MONDAY...BUT IT/S INFLUENCE WILL REMAIN AND KEEP THE AREA
DRY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 110 PM EDT TUE MAR 11 2014
THE RETURN OF COLD AND MOIST LOW LEVEL AIR AIDED BY SOME DAYTIME
HEATING/DESTABILIZATION WILL CONTINUE THE MVFR STRATOCU DECK AT ALL
3 LOCATIONS THROUGH WEDNESDAY MORNING. THE APPROACH OF A DISTURBANCE
EMBEDDED IN THE NW FLOW ALOFT THIS EVNG WILL BRING SOME SHSN TO THE
AREA. THE COMBINATION OF VERY COLD AIR OVER EVEN LIMITED GAPS IN THE
LAKE SUPERIOR ICE COVER AND UPSLOPE INTO SAW SHOULD PRODUCE SOME
-SHSN. DRIER AIR STARTS TO COME IN BY LATE WED MORNING AND SHOULD
SCATTER OUT THE CLOUDS AT IWD AND CMX AND PUT THEM BOTH INTO VFR
LATE WED MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 509 AM EDT TUE MAR 11 2014
A COLD FRONT WILL MOVE THROUGH THE AREA TODAY WITH NW TO N WINDS
INCREASING TO 20 TO 30 KNOTS OVER ERN LAKE SUPERIOR THIS AFTERNOON
INTO TONIGHT. WINDS WILL DIMINISH WED INTO WED NIGHT AS HIGH
PRES BUILDS OVER THE NRN LAKES. WINDS WILL REMAIN AT OR BELOW 20
KNOTS UNTIL FRIDAY WHEN ANOTHER LOW PRES SYSTEM JUST TO THE NORTH OF
LAKE SUPERIOR BRINGS WEST AND NORTHWEST WINDS OF 20 TO 30 KNOTS AS
IT MOVES THROUGH THE REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
740 AM EDT TUE MAR 11 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 509 AM EDT TUE MAR 11 2014
WV IMAGERY AND RUC ANALYSIS INDICATED MAINLY ZONAL MID/UPPER LEVEL
FLOW FROM THE NRN PLAINS THROUGH THE NE CONUS. A SHORTWAVE TROUGH
OVER NRN MANITOBA ON THE LEADING EDGE OF VERY COLD ARCTIC AIR IS
EXPECTED TO SLIDE TO THE SE AS A RIDGE BUILDS INTO WRN CANADA.
ANOTHER SHRTWV OVER SASK IS ALSO EXPECTED TO DIVE TOWARD THE UPPER
MS VALLEY AS THE PATTERN AMPLIFIES. AT THE SFC...A COLD FRONT
TRAILING LOW PRES OVER QUEBEC EXTENDED THROUGH NRN ONTARIO INTO SRN
MANITOBA. TO THE SOUTH...MILD CONDITIONS PREVAILED WITH READINGS
REMAINING IN THE UPPER 30S TO AROUND 40 FROM NRN MN AND NRN WI
THROUGH UPPER MI. EXTENSIVE MID/HIGH CLOUDS HAVE ALSO LIMITED
RADIATIONAL COOLING.
TODAY...THE COLD FRONT IS EXPECTED TO MOVE THROUGH LAKE SUPERIOR AND
UPPER MICHIGAN THIS MORNING BRINGING AN INITIAL INFLUX OF COLDER
AIR. SO...MAX DAYTIME READINGS ARE EXPECTED EARLY WITH TEMPS STEADY
OR SLOWLY FALLING DURING THE AFTERNOON. AS LOW LEVEL MOISTURE NORTH
OF LAKE SUPERIOR MOVES IN AND 850 MB TEMPS FALL TO AROUND -13C BY
00Z/WED...SOME LIGHT SNOW SHOWERS OR FLURRIES MAY BE POSSIBLE LATE
OVER THE NORTH AND WEST PORTIONS OF THE CWA.
TONIGHT...AS THE SASK SHRTWV MOVES TOWARD THE AREA MUCH COLDER
ARCTIC AIR WILL PUSH INTO THE REGION WITH 925 MB TEMPS DROPPING TO
AROUND -21C AND INCREASING WINDS VEERING FROM THE FROM THE NNW TO
NE. A PERIOD OF DEEPER MOISTURE ALONG WITH THE LOW LEVEL
INSTABILITY WILL FAVOR SOME LES FOR LOCATIONS DOWNWIND OF LAKE
SUPERIOR...ESPECIALLY WHERE UPSLOPE FLOW IS MAXIMIZED.
THE POSITION OF THE DGZ WILL ALSO BE MOST FAVORABLE FROM 06Z-12Z/WED.
SATELLITE IMAGERY FROM MON SHOWED ENOUGH BREAKS IN THE ICE COVER FOR
AT LEAST SOME HEAT/MOISTURE FLUX FROM THE LAKE TO SUPPORT LES. SINCE
THE ICE WILL STILL SIGNIFICANTLY REDUCE THE LES POTENTIAL...EXPECT
SNOWFALL AMOUNTS ONLY IN THE 1 TO 2 INCH RANGE...GREATEST OVER THE
HIGHER TERRAIN OF N CNTRL UPPER MI. THE NE WINDS WILL BE LESS
FAVORABLE FOR SNOW AT IWD...WITH THE HIGHER CHANCES/AMOUNTS FARTHER
TO THE WEST...OR FOR THE KEWEENAW WHERE LOW LEVEL CONV WILL BE MINIMAL.
OTHERWISE...THE MUCH COLDER AIR WITH LOWS NEAR ZERO AND WINDS OF 10
TO 20 MPH WILL PRODUCE WIND CHILLS FROM -10 TO -20 LATE TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 343 AM EDT TUE MAR 11 2014
HIGH PRESSURE OVER NORTHWEST ONTARIO WILL LEAD TO NORTHEAST LOW
LEVEL FLOW OVER THE UPPER GREAT LAKES REGION TO START THE
LONG TERM PERIOD. THIS NORTHEAST FLOW WILL BE PRODUCING UPSLOPE SNOW
SHOWERS ESPECIALLY IN NORTH CENTRAL UPPER MICHIGAN TONIGHT AND
EXPECT THOSE TO CONTINUE INTO WEDNESDAY. ALTHOUGH WINDS HAVE CREATED
SOME GAPS IN THE ICE NEAR THE SOUTHERN SHORELINE OF CENTRAL/EASTERN
LAKE SUPERIOR...NOT THINKING THAT THERE WILL BE TOO MUCH ASSISTANCE
TO THE UPSLOPE SNOW SHOWERS EVEN THOUGH 900MB TEMPS WILL BE AROUND
-22C. WITH INVERSION HEIGHTS ONLY AROUND 3-4KFT...WOULDN/T EXPECT
THE SNOW SHOWERS TO BE TOO STRONG AND ANY ADDITIONAL ACCUMULATIONS
SHOULD BE LIGHT WITH THE CLOUD BEING ABOVE THE DGZ. DID SLOWLY
DIMINISH THE SNOW SHOWER CHANCES THROUGH THE DAY AS THE MOISTURE
DEPTH BECOMES SHALLOW AND WINDS BACK TO THE NORTH-NORTHWEST. WITH
THE MODELS SHOWING THE MOISTURE REMAINING BELOW THE STRENGTHENING
INVERSION FROM THE HIGH MOVING OVER THE UPPER GREAT
LAKES...WONDERING IF CLOUDS WILL HOLD OVER THE AREA INTO THE
AFTERNOON (ESPECIALLY OVER THE NORTH CENTRAL). THE NORTHERLY WINDS
AND CLOUDS WILL LEAD TO A VERY COLD DAY ACROSS UPPER MICHIGAN...WITH
HIGHS IN THE UPPER SINGLE DIGITS TO MID TEENS.
STILL LOOKS TO BE A VERY COLD NIGHT ON WEDNESDAY NIGHT AS THE HIGH
SHIFTS SOUTHEAST ACROSS THE CWA. WILL CONTINUE TO SHOW THE COLDEST
VALUES OF -10F TO -18F OVER THE EAST HALF OF THE CWA AND THE SINGLE
DIGITS BELOW ZERO OVER THE WEST HALF. WOULD EXPECT THE TEMPERATURES
TO WARM OVER THE WEST TOWARDS MORNING AS RETURN FLOW DEVELOPS AND
MID CLOUDS BEGINNING TO MOVE IN UNDER WAA AHEAD OF THE NEXT CLIPPER
SYSTEM. GEM/ECMWF/NAM CONSISTENT ON SOME LIGHT PRECIPITATION MOVING
INTO THE WESTERN U.P. WITH THIS WAA ON THURSDAY MORNING. SINCE
THERE HAVE BEEN INDICATIONS OF THIS OVER THE LAST COUPLE OF
DAYS...WILL TREND VALUES UP TO CHANCES AND THEN DIMINISH THEM AS
THEY HEAD EAST OVER THE REST OF THE CWA DURING THE AFTERNOON. WHILE
EARLIER RUNS WERE INDICATING A LACK OF ICE CRYSTALS FOR THIS
PRECIPITATION...IT NOW APPEARS THAT THERE WILL BE ENOUGH MOISTURE
IN THE ICE CRYSTAL AREA TO SUPPORT ALL SNOW. AT THIS POINT...MIGHT
SEE UP TO A HALF INCH TOWARDS IRONWOOD AND THEN DIMINISHING AMOUNTS
HEADING EAST.
BEHIND THIS PRECIPITATION...FOCUS TURNS TO THE LOW CENTERED NEAR
LAKE WINNIPEG AT 18Z THURSDAY. THIS LOW WILL TRACK SOUTHEAST
THROUGH THE UPPER GREAT LAKES REGION LATE THURSDAY NIGHT INTO
FRIDAY. MODELS STILL DIFFERING ON THE SHORTWAVE...WHICH IS NOW
WELL OVER THE PACIFIC...WHICH IN-TURN CONTROLS THE TRACK OF THE LOW.
GFS HAS CONSISTENTLY BEEN THE FARTHEST NORTH (ALONG WITH RECENT RUNS
OF THE UKMET) AND RUNNING THE LOW ALONG THE NORTH SHORE OF LAKE
SUPERIOR...WHILE THE ECMWF TRACKS THE LOW ALONG THE SOUTH SHORE. THE
GEM HAS BEEN BOUNCING BETWEEN THE TWO OVER THE LAST COUPLE DAYS. ALL
IN ALL...THESE DIFFERENCES WON/T HAVE TOO MUCH OF AN AFFECT ON THE
LAND CWA PRECIPITATION...SINCE THE WAA PRECIP WILL BE OVER NORTHEAST
LAKE SUPERIOR AND ONTARIO THURSDAY NIGHT. UNFORTUNATELY FOR THOSE
LOOKING FOR ANOTHER REALLY WARM DAY...IT APPEARS THAT THE WARM AIR
ALOFT WILL MOVE THROUGH ON THURSDAY NIGHT AND THEN AREA WILL SEE
COLDER AIR MOVING IN THROUGH THE DAY. THUS...EXPECT THE WARMEST
TEMPS ON FRIDAY TO BE NEAR LAKE MICHIGAN AND IN THE UPPER 30S TO
AROUND 40.
WITH THE DIFFERENCES IN THE TRACK OF THE LOW...THERE ARE ALSO
DIFFERENCES IN THE ARRIVAL OF THE SECONDARY COLD FRONT AND
NORTHERLY WINDS. COULD BE A LITTLE BREEZY OUT OF THE WEST ON
FRIDAY BEFORE THIS ARRIVES...WITH WINDS TURNING TO THE NORTHWEST AND
EVENTUALLY NORTHERLY ON FRIDAY NIGHT. EXPECT SOME PRECIPITATION
ASSOCIATED WITH THIS COLD SURGE AND WITH SOME GAPS STARTING TO SHOW
IN THE ICE NEAR THE APOSTLE ISLANDS...THERE COULD EVEN BE SOME LAKE
ENHANCED/EFFECT SNOW FRIDAY NIGHT INTO SATURDAY. DIFFICULT TO GO
WITH MUCH MORE THAN SLIGHT/CHANCE POPS WITH THE AMOUNT OF ICE COVER
AND POTENTIAL CHANGES OVER THE NEXT SEVERAL DAYS...SO WILL FOLLOW A
SIMILAR IDEA AS THE PREVIOUS SHIFT. THAT PUTS CHANCES OVER THE
FAVORED NORTHWEST AREAS IN THE WEST ON FRIDAY NIGHT AND THEN
TRANSITION TO TRADITIONAL NORTHWEST-NORTHERLY WIND AREAS FOR
SATURDAY. WITH A HIGH PRESSURE RIDGE NOSING SOUTH FROM ONTARIO ON
SATURDAY NIGHT AND SUNDAY...EXPECT DRIER AIR TO MOVE IN AND HAVE
DIMINISHED POPS HEADING INTO SUNDAY (EVENTHOUGH 850MB TEMPS REMAIN
AROUND -17C). WITH THE COLD TEMPS ALOFT...SHOULD BE 10-20 DEGREES
BELOW NORMAL FOR HIGHS THIS WEEKEND. DEPENDING ON HOW QUICKLY SKIES
CLEAR OUT ON SATURDAY NIGHT...THERE IS THE POTENTIAL FOR SUB ZERO
LOWS OVER MUCH OF THE AREA AND HAVE TRENDED VALUES DOWN A COUPLE
DEGREES. THE COLDEST NIGHT WILL BE SUNDAY NIGHT AS THE AREA OF HIGH
PRESSURE MOVES OVER THE CWA. SINGLE DIGITS BELOW ZERO SEEMS LIKE A
GOOD START AT THIS POINT...BUT WOULDN/T BE SURPRISED TO SEE SOME
COLD SPOTS IN THE TEENS BELOW ZERO. THE HIGH IS EXPECTED TO SHIFT
EAST ON MONDAY...BUT IT/S INFLUENCE WILL REMAIN AND KEEP THE AREA
DRY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 739 AM EDT TUE MAR 11 2014
A COLD FRONT WILL PASS THROUGH UPPER MI THIS MORNING. THE RETURN OF
COLDER AND MOISTER LOW LEVEL AIR AIDED BY SOME DAYTIME
HEATING/DESTABILIZATION SHOULD RESULT IN AN MVFR SC DECK AT ALL 3
LOCATIONS BY THIS AFTERNOON. THE APPROACH OF A DISTURBANCE EMBEDDED
IN THE NW FLOW ALOFT THIS EVNG MAY BRING SOME SHSN TO THE AREA...
ESPECIALLY AT IWD WHICH WL BE CLOSER TO THE TRACK OF THIS SYSTEM.
THE COMBINATION OF VERY COLD AIR OVER EVEN LIMITED GAPS IN THE LAKE
SUPERIOR ICE COVER AND UPSLOPE INTO SAW SHOULD PRODUCE SOME -SHSN.
HOWEVER...NOT CONFIDENT THAT CONDITIONS WILL DROP ANY LOWER THAN
MVFR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 509 AM EDT TUE MAR 11 2014
A COLD FRONT WILL MOVE THROUGH THE AREA TODAY WITH NW TO N WINDS
INCREASING TO 20 TO 30 KNOTS OVER ERN LAKE SUPERIOR THIS AFTERNOON
INTO TONIGHT. WINDS WILL DIMINISH WED INTO WED NIGHT AS HIGH
PRES BUILDS OVER THE NRN LAKES. WINDS WILL REMAIN AT OR BELOW 20
KNOTS UNTIL FRIDAY WHEN ANOTHER LOW PRES SYSTEM JUST TO THE NORTH OF
LAKE SUPERIOR BRINGS WEST AND NORTHWEST WINDS OF 20 TO 30 KNOTS AS
IT MOVES THROUGH THE REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
513 AM EDT TUE MAR 11 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 509 AM EDT TUE MAR 11 2014
WV IMAGERY AND RUC ANALYSIS INDICATED MAINLY ZONAL MID/UPPER LEVEL
FLOW FROM THE NRN PLAINS THROUGH THE NE CONUS. A SHORTWAVE TROUGH
OVER NRN MANITOBA ON THE LEADING EDGE OF VERY COLD ARCTIC AIR IS
EXPECTED TO SLIDE TO THE SE AS A RIDGE BUILDS INTO WRN CANADA.
ANOTHER SHRTWV OVER SASK IS ALSO EXPECTED TO DIVE TOWARD THE UPPER
MS VALLEY AS THE PATTERN AMPLIFIES. AT THE SFC...A COLD FRONT
TRAILING LOW PRES OVER QUEBEC EXTENDED THROUGH NRN ONTARIO INTO SRN
MANITOBA. TO THE SOUTH...MILD CONDITIONS PREVAILED WITH READINGS
REMAINING IN THE UPPER 30S TO AROUND 40 FROM NRN MN AND NRN WI
THROUGH UPPER MI. EXTENSIVE MID/HIGH CLOUDS HAVE ALSO LIMITED
RADIATIONAL COOLING.
TODAY...THE COLD FRONT IS EXPECTED TO MOVE THROUGH LAKE SUPERIOR AND
UPPER MICHIGAN THIS MORNING BRINGING AN INITIAL INFLUX OF COLDER
AIR. SO...MAX DAYTIME READINGS ARE EXPECTED EARLY WITH TEMPS STEADY
OR SLOWLY FALLING DURING THE AFTERNOON. AS LOW LEVEL MOISTURE NORTH
OF LAKE SUPERIOR MOVES IN AND 850 MB TEMPS FALL TO AROUND -13C BY
00Z/WED...SOME LIGHT SNOW SHOWERS OR FLURRIES MAY BE POSSIBLE LATE
OVER THE NORTH AND WEST PORTIONS OF THE CWA.
TONIGHT...AS THE SASK SHRTWV MOVES TOWARD THE AREA MUCH COLDER
ARCTIC AIR WILL PUSH INTO THE REGION WITH 925 MB TEMPS DROPPING TO
AROUND -21C AND INCREASING WINDS VEERING FROM THE FROM THE NNW TO
NE. A PERIOD OF DEEPER MOISTURE ALONG WITH THE LOW LEVEL
INSTABILITY WILL FAVOR SOME LES FOR LOCATIONS DOWNWIND OF LAKE
SUPERIOR...ESPECIALLY WHERE UPSLOPE FLOW IS MAXIMIZED.
THE POSITION OF THE DGZ WILL ALSO BE MOST FAVORABLE FROM 06Z-12Z/WED.
SATELLITE IMAGERY FROM MON SHOWED ENOUGH BREAKS IN THE ICE COVER FOR
AT LEAST SOME HEAT/MOISTURE FLUX FROM THE LAKE TO SUPPORT LES. SINCE
THE ICE WILL STILL SIGNIFICANTLY REDUCE THE LES POTENTIAL...EXPECT
SNOWFALL AMOUNTS ONLY IN THE 1 TO 2 INCH RANGE...GREATEST OVER THE
HIGHER TERRAIN OF N CNTRL UPPER MI. THE NE WINDS WILL BE LESS
FAVORABLE FOR SNOW AT IWD...WITH THE HIGHER CHANCES/AMOUNTS FARTHER
TO THE WEST...OR FOR THE KEWEENAW WHERE LOW LEVEL CONV WILL BE MINIMAL.
OTHERWISE...THE MUCH COLDER AIR WITH LOWS NEAR ZERO AND WINDS OF 10
TO 20 MPH WILL PRODUCE WIND CHILLS FROM -10 TO -20 LATE TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 343 AM EDT TUE MAR 11 2014
HIGH PRESSURE OVER NORTHWEST ONTARIO WILL LEAD TO NORTHEAST LOW
LEVEL FLOW OVER THE UPPER GREAT LAKES REGION TO START THE
LONG TERM PERIOD. THIS NORTHEAST FLOW WILL BE PRODUCING UPSLOPE SNOW
SHOWERS ESPECIALLY IN NORTH CENTRAL UPPER MICHIGAN TONIGHT AND
EXPECT THOSE TO CONTINUE INTO WEDNESDAY. ALTHOUGH WINDS HAVE CREATED
SOME GAPS IN THE ICE NEAR THE SOUTHERN SHORELINE OF CENTRAL/EASTERN
LAKE SUPERIOR...NOT THINKING THAT THERE WILL BE TOO MUCH ASSISTANCE
TO THE UPSLOPE SNOW SHOWERS EVEN THOUGH 900MB TEMPS WILL BE AROUND
-22C. WITH INVERSION HEIGHTS ONLY AROUND 3-4KFT...WOULDN/T EXPECT
THE SNOW SHOWERS TO BE TOO STRONG AND ANY ADDITIONAL ACCUMULATIONS
SHOULD BE LIGHT WITH THE CLOUD BEING ABOVE THE DGZ. DID SLOWLY
DIMINISH THE SNOW SHOWER CHANCES THROUGH THE DAY AS THE MOISTURE
DEPTH BECOMES SHALLOW AND WINDS BACK TO THE NORTH-NORTHWEST. WITH
THE MODELS SHOWING THE MOISTURE REMAINING BELOW THE STRENGTHENING
INVERSION FROM THE HIGH MOVING OVER THE UPPER GREAT
LAKES...WONDERING IF CLOUDS WILL HOLD OVER THE AREA INTO THE
AFTERNOON (ESPECIALLY OVER THE NORTH CENTRAL). THE NORTHERLY WINDS
AND CLOUDS WILL LEAD TO A VERY COLD DAY ACROSS UPPER MICHIGAN...WITH
HIGHS IN THE UPPER SINGLE DIGITS TO MID TEENS.
STILL LOOKS TO BE A VERY COLD NIGHT ON WEDNESDAY NIGHT AS THE HIGH
SHIFTS SOUTHEAST ACROSS THE CWA. WILL CONTINUE TO SHOW THE COLDEST
VALUES OF -10F TO -18F OVER THE EAST HALF OF THE CWA AND THE SINGLE
DIGITS BELOW ZERO OVER THE WEST HALF. WOULD EXPECT THE TEMPERATURES
TO WARM OVER THE WEST TOWARDS MORNING AS RETURN FLOW DEVELOPS AND
MID CLOUDS BEGINNING TO MOVE IN UNDER WAA AHEAD OF THE NEXT CLIPPER
SYSTEM. GEM/ECMWF/NAM CONSISTENT ON SOME LIGHT PRECIPITATION MOVING
INTO THE WESTERN U.P. WITH THIS WAA ON THURSDAY MORNING. SINCE
THERE HAVE BEEN INDICATIONS OF THIS OVER THE LAST COUPLE OF
DAYS...WILL TREND VALUES UP TO CHANCES AND THEN DIMINISH THEM AS
THEY HEAD EAST OVER THE REST OF THE CWA DURING THE AFTERNOON. WHILE
EARLIER RUNS WERE INDICATING A LACK OF ICE CRYSTALS FOR THIS
PRECIPITATION...IT NOW APPEARS THAT THERE WILL BE ENOUGH MOISTURE
IN THE ICE CRYSTAL AREA TO SUPPORT ALL SNOW. AT THIS POINT...MIGHT
SEE UP TO A HALF INCH TOWARDS IRONWOOD AND THEN DIMINISHING AMOUNTS
HEADING EAST.
BEHIND THIS PRECIPITATION...FOCUS TURNS TO THE LOW CENTERED NEAR
LAKE WINNIPEG AT 18Z THURSDAY. THIS LOW WILL TRACK SOUTHEAST
THROUGH THE UPPER GREAT LAKES REGION LATE THURSDAY NIGHT INTO
FRIDAY. MODELS STILL DIFFERING ON THE SHORTWAVE...WHICH IS NOW
WELL OVER THE PACIFIC...WHICH IN-TURN CONTROLS THE TRACK OF THE LOW.
GFS HAS CONSISTENTLY BEEN THE FARTHEST NORTH (ALONG WITH RECENT RUNS
OF THE UKMET) AND RUNNING THE LOW ALONG THE NORTH SHORE OF LAKE
SUPERIOR...WHILE THE ECMWF TRACKS THE LOW ALONG THE SOUTH SHORE. THE
GEM HAS BEEN BOUNCING BETWEEN THE TWO OVER THE LAST COUPLE DAYS. ALL
IN ALL...THESE DIFFERENCES WON/T HAVE TOO MUCH OF AN AFFECT ON THE
LAND CWA PRECIPITATION...SINCE THE WAA PRECIP WILL BE OVER NORTHEAST
LAKE SUPERIOR AND ONTARIO THURSDAY NIGHT. UNFORTUNATELY FOR THOSE
LOOKING FOR ANOTHER REALLY WARM DAY...IT APPEARS THAT THE WARM AIR
ALOFT WILL MOVE THROUGH ON THURSDAY NIGHT AND THEN AREA WILL SEE
COLDER AIR MOVING IN THROUGH THE DAY. THUS...EXPECT THE WARMEST
TEMPS ON FRIDAY TO BE NEAR LAKE MICHIGAN AND IN THE UPPER 30S TO
AROUND 40.
WITH THE DIFFERENCES IN THE TRACK OF THE LOW...THERE ARE ALSO
DIFFERENCES IN THE ARRIVAL OF THE SECONDARY COLD FRONT AND
NORTHERLY WINDS. COULD BE A LITTLE BREEZY OUT OF THE WEST ON
FRIDAY BEFORE THIS ARRIVES...WITH WINDS TURNING TO THE NORTHWEST AND
EVENTUALLY NORTHERLY ON FRIDAY NIGHT. EXPECT SOME PRECIPITATION
ASSOCIATED WITH THIS COLD SURGE AND WITH SOME GAPS STARTING TO SHOW
IN THE ICE NEAR THE APOSTLE ISLANDS...THERE COULD EVEN BE SOME LAKE
ENHANCED/EFFECT SNOW FRIDAY NIGHT INTO SATURDAY. DIFFICULT TO GO
WITH MUCH MORE THAN SLIGHT/CHANCE POPS WITH THE AMOUNT OF ICE COVER
AND POTENTIAL CHANGES OVER THE NEXT SEVERAL DAYS...SO WILL FOLLOW A
SIMILAR IDEA AS THE PREVIOUS SHIFT. THAT PUTS CHANCES OVER THE
FAVORED NORTHWEST AREAS IN THE WEST ON FRIDAY NIGHT AND THEN
TRANSITION TO TRADITIONAL NORTHWEST-NORTHERLY WIND AREAS FOR
SATURDAY. WITH A HIGH PRESSURE RIDGE NOSING SOUTH FROM ONTARIO ON
SATURDAY NIGHT AND SUNDAY...EXPECT DRIER AIR TO MOVE IN AND HAVE
DIMINISHED POPS HEADING INTO SUNDAY (EVENTHOUGH 850MB TEMPS REMAIN
AROUND -17C). WITH THE COLD TEMPS ALOFT...SHOULD BE 10-20 DEGREES
BELOW NORMAL FOR HIGHS THIS WEEKEND. DEPENDING ON HOW QUICKLY SKIES
CLEAR OUT ON SATURDAY NIGHT...THERE IS THE POTENTIAL FOR SUB ZERO
LOWS OVER MUCH OF THE AREA AND HAVE TRENDED VALUES DOWN A COUPLE
DEGREES. THE COLDEST NIGHT WILL BE SUNDAY NIGHT AS THE AREA OF HIGH
PRESSURE MOVES OVER THE CWA. SINGLE DIGITS BELOW ZERO SEEMS LIKE A
GOOD START AT THIS POINT...BUT WOULDN/T BE SURPRISED TO SEE SOME
COLD SPOTS IN THE TEENS BELOW ZERO. THE HIGH IS EXPECTED TO SHIFT
EAST ON MONDAY...BUT IT/S INFLUENCE WILL REMAIN AND KEEP THE AREA
DRY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 121 AM EDT TUE MAR 11 2014
WITH LLVL DRY AIR IN PLACE AND SOME HI CLDS/STEADY WINDS LIMITING
THE DIURNAL FALL OF TEMP...EXPECT VFR CONDITIONS TO DOMINATE AT ALL
3 TAFS SITES THRU SUNRISE. A COLD FRONT WL PASS THRU UPR MI ON TUE
MRNG. THE RETURN OF COLDER AND MOISTER LLVL AIR AIDED BY SOME
DAYTIME HEATING/DESTABILIZATION SHOULD RESULT IN AN MVFR SC DECK AT
ALL 3 LOCATIONS BY TUE AFTN. THE APRCH OF A DISTURBANCE EMBEDDED IN
THE NW FLOW ALOFT THIS EVNG MAY BRING SOME SHSN TO THE AREA...
ESPECIALLY AT IWD WHICH WL BE CLOSER TO THE TRACK OF THIS SYSTEM.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 509 AM EDT TUE MAR 11 2014
A COLD FRONT WILL MOVE THROUGH THE AREA TODAY WITH NW TO N WINDS
INCREASING TO 20 TO 30 KNOTS OVER ERN LAKE SUPERIOR THIS AFTERNOON
INTO TONIGHT. WINDS WILL DIMINISH WED INTO WED NIGHT AS HIGH
PRES BUILDS OVER THE NRN LAKES. WINDS WILL REMAIN AT OR BELOW 20
KNOTS UNTIL FRIDAY WHEN ANOTHER LOW PRES SYSTEM JUST TO THE NORTH OF
LAKE SUPERIOR BRINGS WEST AND NORTHWEST WINDS OF 20 TO 30 KNOTS AS
IT MOVES THROUGH THE REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DULUTH MN
320 PM CDT TUE MAR 11 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY AFTERNOON)
ISSUED AT 315 PM CDT TUE MAR 11 2014
MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND SKY COVER AND
SUBSEQUENT LAKE EFFECT SNOW SHOWERS ALONG THE SOUTH SHORE FROM
DULUTH TO ASHLAND TO MONTREAL TONIGHT...ALONG WITH FALLING
TEMPERATURES ACROSS THE NRN COUNTIES UNDER MOSTLY CLEAR SKIES
EARLY WED MORNING.
WEAK SFC COLD FRONT CONTINUES TO SLIDE TO THE SOUTH ACROSS NRN MN
AS HIGH PRESSURE BUILDS IN NORTH OF THE FRONT OVER CENTRAL
MANITOBA AND WRN ONTARIO. A TIGHT SFC PRES GRADIENT HAS DEVELOPED
OVER THE REGION WHICH HAS ALLOWED W/NW WINDS TO INCREASE AND
BECOME GUSTY THIS AFTERNOON. AREA OBSERVATIONS HAVE INDICATED
SUSTAINED WINDS AROUND 10 TO 15 MPH AND GUSTS 20 TO 25 MPH.
THE AIR MASS IS FAIRLY DRY OVER THE NORTHLAND AND MOST OF THE MID
AND HIGH LEVEL CLOUDS FROM THIS MORNING HAVE DISSIPATED THIS
AFTERNOON. AN AREA OF MID LEVEL STRATO-CU HAS DEVELOPED OVER THE
ARROWHEAD...BUT SHOULD MIX OUT BY THE EVENING. THE SFC HIGH TO THE
NORTH WILL SHIFT TO THE SOUTH AND SE TONIGHT AND BECOME POSITIONED
JUST NORTH OF THE ARROWHEAD IN WRN ONTARIO WHICH WILL COMBINE WITH
A STRENGTHENING AREA OF LOW PRESSURE OVER THE SRN GREAT LAKES
REGION TO PRODUCE A MODEST NE WIND OVER WRN LAKE SUPERIOR. THE
COLD AIR ASSOCIATED WITH THE HIGH WILL ADVECT OVER THE RELATIVELY
WARMER LAKE AND PRODUCE SCATTERED LAKE EFFECT SNOW SHOWERS FROM
THE TWIN PORTS TO THE GOGEBIC RANGE DURING THE LATE EVENING AND
OVERNIGHT HOURS. 850MB TEMPS WILL BE ROUGHLY -19 TO -22 DEG
C...WITH LAKE TEMPS AROUND 1 TO 2 DEG C. THIS SHOULD ALLOW BL
LAPSE RATES TO SUPPORT LES. HOWEVER...THE DEPTH OF THE LAYER MIGHT
BE AN INHIBITING FACTOR WITH BDY LAYER HEIGHTS AROUND 4K FT.
RECENT WARMING AND STRONG WINDS HAVE ALLOWED MUCH OF THE LAKE TO
LOSE ITS SOLID ICE COVER...SO WITH MUCH OF WRN LAKE SUPERIOR
OPEN...CONDITIONS ARE NOW SLIGHTLY MORE FAVORABLE AS WELL. THE
CHANCE FOR LES WILL BE FLEETING AS DRIER AIR MOVES IN BY MID-LATE
WED MORNING. SNOW AMTS WILL GENERALLY BE A HALF INCH OR
LESS...WITH SOME LOCATIONS AROUND OR JUST ABOVE AN INCH FROM
DOUGLAS TO IRON COUNTY.
TEMPERATURES WILL DROP FAIRLY RAPIDLY TONIGHT UNDER AREAS THAT SEE
MOSTLY CLEAR SKIES. THE BEST CHANCE FOR SUSTAINED SIGNIFICANT
CLEARING WILL CONTINUE TO BE ACROSS THE NORTH AND OVER THE WRN
COUNTIES. AREAS TO THE EAST AND SE WILL BE UNDER THE INFLUENCE OF
LE CLOUDS. THE COLDEST AIR WILL BE ACROSS THE NORTH WHERE TEMPS
WILL DIP INTO THE SINGLE DIGITS AND TEENS BELOW ZERO. LIGHT NW
WINDS WILL PRODUCE WIND CHILL VALUES AROUND -15 TO -20.
TEMPERATURES WILL HAVE A DIFFICULT TIME WARMING DURING THE DAY
TOMORROW WITH THE COLD AIR MASS IN PLACE. HOWEVER...A WAA PATTERN
WILL DEVELOP FROM WEST TO EAST GOING INTO THE LATE AFTERNOON
PERIOD. LOOK FOR HIGHS TOMORROW TO TOP OUT IN THE UPPER TEENS AND
LOWER TO MID 20S. SHOULD SEE SKIES CLEAR OFF EARLY WED AFTERNOON
BEFORE ANOTHER MID-HIGH DECK OF CLOUDS MOVES IN FROM THE WEST BY
THE LATE AFTERNOON PERIOD.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 315 PM CDT TUE MAR 11 2014
SEVERAL SHORTWAVES WILL IMPACT THE NORTHLAND THROUGH THE EXTENDED
PERIOD BRINGING CHANCES FOR LIGHT SNOW...BUT NO SIGNIFICANT SNOWFALL
IS EXPECTED AT THIS TIME.
A PERIOD OF STRONG WAA WILL OCCUR WEDNESDAY NIGHT AND BRING A CHANCE
FOR MAINLY LIGHT SNOW FROM WEST TO EAST ACROSS THE NORTHLAND. THE
NAM IS MOST BULLISH WITH PRECIPITATION AMOUNTS AND WE LEANED TOWARD
IT AND INCREASED POPS/SNOW AMOUNTS. IT LOOKS LIKE A HALF TO AROUND
ONE INCH OF SNOW WILL OCCUR WITH THE WAA. SOUNDINGS LOOK SUPPORTIVE
FOR FREEZING DRIZZLE AS WELL...BUT THE BETTER LIFT WILL BE WITH THE
INITIAL SURGE OF WAA AND WE DO NOT EXPECT MUCH TO OCCUR AFTER THE
MAIN AREA OF PRECIPITATION MOVES THROUGH. THURSDAY LOOKS TO BE MILD
AND WE KEPT HIGHS IN THE FORTIES...WHICH IS ON THE HIGH END OF MOST
GUIDANCE. RECENT MODEL GUIDANCE HAS BEEN TOO COOL OVER THE PAST
COUPLE DAYS WHEN TEMPS HAVE BEEN MILD.
A LOW WILL MOVE ACROSS FAR NORTHERN MINNESOTA OVER EASTERN LAKE
SUPERIOR THURSDAY NIGHT...USHERING IN COOLER AIR. THERE WILL BE A
CHANCE FOR LIGHT SNOW WITH THIS FEATURE...BUT AMOUNTS WILL BE LIGHT
THURSDAY NIGHT INTO FRIDAY. HIGHS FRIDAY WILL RANGE FROM THE MID
THIRTIES TO LOWER FORTIES.
THERE WILL BE A CHANCE FOR SOME LAKE EFFECT SNOW SATURDAY...AND
DEPENDING ON THE EXTENT OF OPEN WATER...SOME MEASURABLE SNOW IS
LOOKING MORE LIKELY ALONG THE SOUTH SHORE. COOLER HIGHS IN THE
TWENTIES ARE EXPECTED SATURDAY/SUNDAY. THE ECMWF CONTINUES TO WAFFLE
FROM RUN TO RUN SUNDAY NIGHT WITH AN AREA OF LOW PRESSURE. IT HAS
GONE BACK TO BRINGING A CHANCE FOR SNOW TO OUR SOUTHERN CWA...BUT WE
KEPT THE FORECAST DRY UNTIL BETTER CONTINUITY OCCURS.
THERE WILL BE A CHANCE FOR SNOW EARLY NEXT WEEK AS ANOTHER SHORTWAVE
MOVES THROUGH THE REGION. HIGHS MONDAY WILL BE IN THE MID TWENTIES
TO LOWER THIRTIES...WITH LOWER TO MID THIRTIES TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1244 PM CDT TUE MAR 11 2014
COLD AIR ADVECTION WILL OCCUR TODAY/TONIGHT WITH A SHORTWAVE
MOVING THROUGH AS WELL TONIGHT. STRATOCU HAS DEVELOPED OVER FAR
NORTHERN MINNESOTA/NORTHWEST ONTARIO. WE EXPECT SCATTERED TO
BROKEN CLOUDS FROM 2500-3500 TO MOVE INTO MOST TAF SITES THIS
AFTERNOON INTO TONIGHT...WITH A FEW PERIODS OF LIGHT SNOW OR
FLURRIES. THE RAP HAS DONE AN OK JOB DEPICTING THE CLOUDS...BUT
DOES SEEM TO BE OVERDOING THE COVERAGE. THE LOWER CLOUDS WILL
DISSIPATE FROM NORTH TO SOUTH LATER TONIGHT INTO WEDNESDAY
MORNING.
GUSTY NORTH-NORTHWEST WINDS WILL OCCUR THIS AFTERNOON...THEN WILL
DIMINISH TONIGHT. WINDS WILL VEER TO EAST-NORTHEAST. THERE IS MORE
OPEN WATER OVER LAKE SUPERIOR PER MODIS IMAGERY...AND THAT SHOULD
ALLOW MORE LAKE CLOUDS/SNOW TO DEVELOP TONIGHT WITH THE COLD AIR
MOVING IN. AS WINDS TURN MORE EASTERLY LATE TONIGHT...A BETTER
CHANCE FOR SOME LES/CLOUDS WILL OCCUR IN KDLH.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 4 20 9 43 / 30 10 60 10
INL -8 19 12 44 / 10 10 60 10
BRD 7 23 15 47 / 10 10 50 0
HYR 3 19 6 44 / 20 10 50 10
ASX 3 13 4 46 / 40 20 50 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...BJT
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1246 PM CDT TUE MAR 11 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 345 AM CDT TUE MAR 11 2014
AT 345AM/0845Z...THERE WAS A LOW PRESSURE SYSTEM IN THE
CENTRAL/SOUTHERN PLAINS. ITS ASSOCIATED BAND OF PCPN NORTH OF THE
LOW...STRETCHING FROM WEST TO EAST...WAS MOVING THROUGH SOUTH
DAKOTA. MUCH OF THE UPPER MIDWEST AND NORTHERN PLAINS HAD BKN/OVC
CLOUD COVER...MOSTLY FROM MID/HIGH CLOUDS. ANOTHER LOW PRESSURE
SYSTEM WAS OVER WESTERN QUEBEC. A COLD FRONT EXTENDED WESTWARD
FROM THE QUEBEC LOW TO SOUTHERN MANITOBA AND SASKATCHEWAN. THERE
WAS CONSIDERABLY COLDER AIR...AIR OF ARCTIC ORIGINS...BEHIND THE
COLD FRONT. MUCH OF ONTARIO...MANITOBA...AND SASKATCHEWAN HAD
BKN/OVC LOW LEVEL CLOUD COVER. THE NORTHLAND HAD TEMPERATURES
RANGING FROM THE UPPER 30S ACROSS THE SOUTHERN FORECAST AREA TO
THE UPPER 20S ACROSS THE NORTHERN FORECAST AREA. THERE WERE WNW TO
NW WINDS OF ABOUT 5 TO 10 MPH.
TODAY...THE PLAINS LOW PRESSURE SYSTEM WILL SHIFT EAST TO
MISSOURI. ITS BAND OF PCPN IS EXPECTED TO REMAIN JUST SOUTH OF
THE FORECAST AREA. THE ASSOCIATED MID/HIGH CLOUDS SHOULD CONTINUE
TO COVER MUCH OF THE FORECAST AREA THROUGH THIS MORNING...BUT THEN
BEGIN TO SCATTER AND SHIFT SOUTH THIS AFTERNOON. WHILE WE WILL
LIKELY BEGIN TO DITCH THE MID/HIGH CLOUDS....THE LOW CLOUDS IN
CANADA WILL LIKELY SPREAD BEGIN TO SPREAD INTO THE FORECAST AREA
LATE THIS MORNING AND THIS AFTERNOON AS THE CANADIAN COLD FRONT
MOVES GRADUALLY MOVES SOUTH THROUGH THE FORECAST AREA. THERE COULD
BE SOME SNOW FLURRIES THIS AFTERNOON...AT LEAST ACROSS THE
NORTHERN FORECAST AREA. THE LATEST MODEL GUIDANCE SUGGESTED WARMER
TEMPERATURES FOR THE SOUTHERN FORECAST AREA...SO I INCREASED THE
HIGH TEMPERATURES TODAY SINCE THOSE MODELS ARE IN DECENT
AGREEMENT. THE HIGHS WILL BE SLIGHTLY BELOW NORMAL TODAY.
TONIGHT...THE ARCTIC AIR WILL CONTINUE TO POUR INTO THE NORTHLAND.
THE NORTHERLY WINDS OVER WESTERN LAKE SUPERIOR WILL STRENGTHEN
AND BECOME NNE TO ENE. CONSIDERING THAT THERE IS A LOT MORE OPEN
WATER NOW DUE TO THE RECENT WARM WEATHER...THE COLD FLOW OVER THE
LAKE WILL RESULT IN SOME DECENT CHANCES FOR LAKE EFFECT SNOW. I
INCREASED THE PCPN CHANCES ACROSS NW WISCONSIN...THE TWIN PORTS
AREA...AND FOR THE ST. CROIX RIVER VALLEY AREA. MOST OF THE MODELS
DO NOT APPEAR TO BE PICKING UP ON THE LAKE EFFECT SNOW
THREAT...BUT THE NAM12 AND SREF ARE DOING MUCH BETTER HANDLING
THIS. SOME AREAS WILL LIKELY GET ABOUT A HALF TO A FULL INCH. MORE
IS POSSIBLE...BUT I THINK WE WILL GET A BETTER IDEA OF THE THREAT
WHEN THIS TIMEFRAME COMES INTO VIEW FOR MORE OF THE HIGH
RESOLUTION MODELS. THE BEST PERIOD OF LAKE EFFECT SNOW APPEARS TO
BE FROM ABOUT 9 PM TO 3 AM. THIS IS WHEN OVERALL MOISTURE IN THE
FLOW OVER THE LAKE LOOKS TO BE BEST...AND THEN DRIER AIR WILL
BEGIN TO MOVE INTO THE REGION VERY LATE TONIGHT. HIGH PRESSURE
WILL BEGIN TO MOVE OUT OF CANADA AND INTO NORTHERN MINNESOTA AFTER
MIDNIGHT. THE MODELS ARE IN PRETTY GOOD AGREEMENT THAT THERE WILL
BE CLEARING ACROSS THE WESTERN AND NORTHERN FORECAST AREA...AND
DECREASING WINDS. THIS WILL LIKELY ALLOW TEMPERATURES TO QUICKLY
FALL AROUND AND SHORTLY BEFORE DAWN WEDNESDAY...ESPECIALLY ACROSS
FAR NORTHERN MINNESOTA. I DECREASED THE OVERNIGHT LOW
TEMPERATURES. THE FORECAST NOW HAS A RANGE OF MID TO UPPER SINGLE
DIGITS ACROSS THE SOUTHERN FORECAST AREA...TO THE MID TO UPPER
SINGLE DIGITS BELOW ZERO ACROSS THE NORTHERN FORECAST AREA.
WEDNESDAY...THE HIGH PRESSURE WILL MOVE THROUGH THE REGION. THIS
WILL CUT OFF THE THREAT OF LAKE EFFECT SNOW AS THE WINDS OVER
WESTERN LAKE SUPERIOR LIGHTEN. MUCH OF THE FORECAST AREA WILL
LIKELY SEE PLENTY OF SUNSHINE DURING THE MIDDLE OF THE DAY. THIS
WILL HELP BOLSTER THE TEMPERATURES...BUT I DID LOWER THE HIGHS A
BIT BASED ON THE LATEST MODELS BEING MUCH COLDER THAN THE PREVIOUS
FORECAST. A STRONG WARM FRONT WILL MOVE INTO THE NORTHERN PLAINS
AND SOUTH CENTRAL CANADA WEDNESDAY...BRINGING WITH IT WARM AND
MORE MOIST AIR OF PACIFIC ORIGINS. THERE COULD BE SOME LIGHT PCPN
THAT DEVELOPS ACROSS THE WESTERN FORECAST BY THE LATE
AFTERNOON...BUT SINCE ONLY THE GFS WAS THIS QUICK AT BRINGING IN
THE PCPN...I DECIDED TO KEEP THE AFTERNOON FORECAST DRY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 345 AM CDT TUE MAR 11 2014
HAVE INCREASED TO BROADBRUSH HIGH CHANCE POPS WED NIGHT/THURS
MORNING AS A WARM FRONT/MID LEVEL OMEGA TRANSLATES EAST ACROSS
THE NORTHLAND...TRIGGERING A BRIEF WINDOW OF LIGHT SNOW SHOWERS.
ACCUMULATIONS WILL BE MINIMAL...GENERALLY A HALF TO ONE INCH.
THERE WILL BE A BRIEF BREAK IN THE PRECIPITATION THURSDAY AS THE
WARM SECTOR PUSHES ACROSS THE FORECAST AREA...ALLOWING FOR TEMPS
TO WARM WELL INTO THE 40S AND POSSIBLY SOME 50S.
LATEST MODELS SHOW SLIGHT DIFFERENCES IN TRACK AND TIMING...BUT
ARE IN OVERALL GOOD AGREEMENT THAT A SHORT WAVE WITH CLOSED
H85/SFC LOW DROPS OUT OF CANADA AND TRACKS ACROSS THE WESTERN
GREAT LAKES REGION THURS NIGHT/FRIDAY. AT THIS TIME...MODELS
SUGGEST THERE IS A LACK OF MOISTURE ACCOMPANYING THE ASSOCIATED
COLD FRONT PASSAGE...WITH THE BEST CHANCE FOR AN INCH OR TWO OF
SNOW NEAR THE LOW CENTER ALONG THE INTERNATIONAL BORDER/MN
ARROWHEAD ZONES. HOWEVER...INSTABILITY SNOW SHOWERS WILL BE COMMON
IN THE COLD AIR MASS BEHIND THE DEPARTING SYSTEM FRIDAY/FRIDAY
NIGHT.
LONG RANGE MODELS ARE IN GOOD AGREEMENT THAT AN AREA OF
CANADIAN HIGH PRESSURE BUILDS INTO THE REGION SATURDAY...SETTLING
OVER THE WESTERN GREAT LAKES SUNDAY. AS THE HIGH DEPARTS TO THE
EAST MONDAY...IT WILL BE REPLACED BY UPPER LEVEL RIDGING AND A
WARM SOUTHERLY FLOW FOUND AHEAD OF AN DEEPENING LOW PRESSURE
SYSTEM IN THE DAKOTAS. ALTHOUGH THERE ARE SIGNIFICANT DIFFERENCES
IN STRENGTH AND TRACK OF THE LOW...THERE IS AGREEMENT THAT THIS
ORGANIZED SYSTEM DIGS ACROSS THE UPPER PLAINS AND TRACKS OVER THE
NORTHLAND DURING THE FIRST HALF OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1244 PM CDT TUE MAR 11 2014
COLD AIR ADVECTION WILL OCCUR TODAY/TONIGHT WITH A SHORTWAVE
MOVING THROUGH AS WELL TONIGHT. STRATOCU HAS DEVELOPED OVER FAR
NORTHERN MINNESOTA/NORTHWEST ONTARIO. WE EXPECT SCATTERED TO
BROKEN CLOUDS FROM 2500-3500 TO MOVE INTO MOST TAF SITES THIS
AFTERNOON INTO TONIGHT...WITH A FEW PERIODS OF LIGHT SNOW OR
FLURRIES. THE RAP HAS DONE AN OK JOB DEPICTING THE CLOUDS...BUT
DOES SEEM TO BE OVERDOING THE COVERAGE. THE LOWER CLOUDS WILL
DISSIPATE FROM NORTH TO SOUTH LATER TONIGHT INTO WEDNESDAY
MORNING.
GUSTY NORTH-NORTHWEST WINDS WILL OCCUR THIS AFTERNOON...THEN WILL
DIMINISH TONIGHT. WINDS WILL VEER TO EAST-NORTHEAST. THERE IS MORE
OPEN WATER OVER LAKE SUPERIOR PER MODIS IMAGERY...AND THAT SHOULD
ALLOW MORE LAKE CLOUDS/SNOW TO DEVELOP TONIGHT WITH THE COLD AIR
MOVING IN. AS WINDS TURN MORE EASTERLY LATE TONIGHT...A BETTER
CHANCE FOR SOME LES/CLOUDS WILL OCCUR IN KDLH.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 34 4 19 10 / 10 30 10 50
INL 27 -9 19 15 / 20 10 0 50
BRD 36 7 23 15 / 10 10 10 40
HYR 36 3 17 8 / 10 20 10 40
ASX 37 3 13 4 / 10 30 20 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM...GRANING
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1204 PM CDT TUE MAR 11 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT TUE MAR 11 2014
MOST SIGNIFICANT PRECIPITATION OVER THE NEXT 7 DAYS WILL FALL WITHIN
THE NEXT 12 HRS OF THIS DISCUSSION AS AN IMPRESSIVE FRONTGENETICALLY
DRIVEN BAND OF PRECIP BLOSSOMS ACROSS THE SOUTHERN HALF OF THE CWA
THIS MORNING. HIRES MODELS CONTINUE TO BE TOO COOL WITH THE LOW
LEVEL THERMAL FIELDS...AND THUS THEIR PTYPE ALGORITHMS ARE LIKELY
OVERDOING THE SNOWFALL ACROSS THE REGION DURING THE INITIAL
DEVELOPMENT EARLY THIS MORNING. HOWEVER...BUFR FORECAST SOUNDINGS
SHOW TREMENDOUS LIFT ALONG THE LOW/MID LEVEL FRONT AS INFERRED FROM
THE SHARP WIND SHIFT WITHIN THE H850-700 LAYER. ASIDE FROM THE
LOWEST FEW HUNDRED METERS THE ENTIRE SOUNDING IS BELOW FREEZING...SO
ANTICIPATING THAT THE RAIN WILL CHANGE OVER TO A RAIN SNOW MIX
AROUND 6-7AM...AND THEN QUICKLY OVER TO HEAVY WET SNOW AROUND MID
MORNING ACROSS SOUTHERN MN.
SNOW RATIOS WILL BE IN THE MID-SINGLE DIGITS...BUT QPF SHOULD EASILY
MANAGE AROUND 0.20 TO 0.30 YIELDING SNOWFALL TOTALS OF 1-2 INCHES
UNDER THE HEAVIEST BAND OF SNOW. AT THIS POINT THE RAP 11.07 PLACES
THIS HEAVY BAND FROM CANBY MN EASTWARD THROUGH THE SOUTHERN
METRO...AND THEREFORE ALL THE HIRES MODELS THAT USE THE RAP FOR
THEIR INITIAL BOUNDARY CONDITIONS ARE SUBCONSCIOUSLY DRAWN TO THIS
CONCLUSION. HOWEVER...THE H850-700MB FGEN...WHICH AS OF EARLY THIS
MORNING MATCHES UP NICELY WITH THE ONGOING PRECIP...SHIFTS SOUTHEAST
FROM CANBY TO MANKATO AND OWATONNA. BASED ON THAT DIAGNOSTIC
TOOL...EXPECT THE PRECIP TO FALL TOWARD THE SOUTHERN SIDE OF THE
CURRENT MODEL GENERATED QPF FIELD. AT THIS POINT NOT ANTICIPATING
ANY ADVISORY CRITERIA SNOWFALL AMOUNTS...BUT EXPECT HEAVY WET SNOW
WITH 1/2 TO 1/4 MI VISIBILITY POSSIBLE AT TIMES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 345 AM CDT TUE MAR 11 2014
LOOKING AHEAD...COLD AIR WILL SURGE SOUTHWARD BEHIND THIS SYSTEM AS
IT STRENGTHENS INTO A MAJOR STORM OVER NEW ENGLAND. CLOSER TO HOME
TEMPERATURES WILL FALL BELOW FREEZING TONIGHT AND REMAIN THERE UNTIL
THURSDAY WHEN THE NEXT SHOT OF LEE-SIDE WARM AIR SPREADS ACROSS THE
REGION. THIS WILL BRING TEMPERATURES INTO THE 40S ONCE AGAIN...WITH
50S IN WESTERN MN. THERE IS A CHANCE FOR SOME LIGHT PRECIP AHEAD OF
THIS WARM AIR ADVECTION...MAINLY ALONG THE ST CROIX RIVER VALLEY.
THIS WARMUP WILL BE SHORT LIVED AS COLD AIR SPREADS SOUTHWARD AND
LASTS INTO NEXT WEEK. NO SIGNIFICANT PRECIPITATION IS EXPECTED UNTIL
THE NEXT STORM SYSTEM ARRIVES ON TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1155 AM CDT TUE MAR 11 2014
RAIN/SNOW HAS SHIFTED SOUTH OF THE TAF SITES FOR THE REMAINDER OF
THE PERIOD. VFR CONDITIONS EXPECTED THROUGH THE AFTERNOON...WITH
PERHAPS SOME LOWER CIGS DEVELOPING THIS EVENING AS THE UPPER
TROUGH SWINGS SOUTHEAST. MENTIONED SOME MVFR CIGS DEVELOPING INTO
WEST CENTRAL WISCONSIN IN THE 03Z-04Z PERIOD. THIS MAY BE A BIT
FAST BUT MODELS ARE SUGGESTING DEVELOPMENT INTO THE EVENING. WILL
KEEP THE VFR CIGS FARTHER TO THE WEST INTO MINNESOTA...BUT
CONFIDENCE IS NOT THAT HIGH...ESPECIALLY TOWARD KSTC/KMSP.
DETERMINISTIC MODELS CONTINUE TO SUGGEST INVERTED TROUGH
DEVELOPMENT ALONG THE MN/WI BORDER AREA. WILL HAVE TO MONITOR HOW
AR WEST THIS OCCUR. OTHERWISE...MAINLY MID/HIGH LEVEL CLOUDS
THROUGH THE DAY WED. NORTHERLY FLOW MUCH OF THE AFTERNOON...WITH
SOME GUSTS 15-20KTS PSBL. THE NORTH WIND CONTINUE INTO WED BUT
SHOULD DIMINISH DURING THE DAY AS THE HIGH DROPS IN.
KMSP...
VFR CONDS EXPECTED INTO THE EVENING. SOME THREAT OF MVFR CIGS
DEVELOPING INTO THE COMING EVENING...WITH BEST CHANCES EAST OF THE
AIRPORT. NORTH WINDS THROUGH MOST OF THE PERIOD...BECOMING MORE
WEST LATER WED AFTERNOON AS THE SURFACE RIDGE MOVES IN.
/OUTLOOK FOR KMSP/
WED NIGHT...VFR. CHC MVFR CIG -SN. W TO SW WIND 8 KTS.
THU...VFR. SW WIND 5-10 KTS.
FRI...VFR. W 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...JRB
AVIATION...DWE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
704 AM CDT TUE MAR 11 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT TUE MAR 11 2014
MOST SIGNIFICANT PRECIPITATION OVER THE NEXT 7 DAYS WILL FALL WITHIN
THE NEXT 12 HRS OF THIS DISCUSSION AS AN IMPRESSIVE FRONTGENETICALLY
DRIVEN BAND OF PRECIP BLOSSOMS ACROSS THE SOUTHERN HALF OF THE CWA
THIS MORNING. HIRES MODELS CONTINUE TO BE TOO COOL WITH THE LOW
LEVEL THERMAL FIELDS...AND THUS THEIR PTYPE ALGORITHMS ARE LIKELY
OVERDOING THE SNOWFALL ACROSS THE REGION DURING THE INITIAL
DEVELOPMENT EARLY THIS MORNING. HOWEVER...BUFR FORECAST SOUNDINGS
SHOW TREMENDOUS LIFT ALONG THE LOW/MID LEVEL FRONT AS INFERRED FROM
THE SHARP WIND SHIFT WITHIN THE H850-700 LAYER. ASIDE FROM THE
LOWEST FEW HUNDRED METERS THE ENTIRE SOUNDING IS BELOW FREEZING...SO
ANTICIPATING THAT THE RAIN WILL CHANGE OVER TO A RAIN SNOW MIX
AROUND 6-7AM...AND THEN QUICKLY OVER TO HEAVY WET SNOW AROUND MID
MORNING ACROSS SOUTHERN MN.
SNOW RATIOS WILL BE IN THE MID-SINGLE DIGITS...BUT QPF SHOULD EASILY
MANAGE AROUND 0.20 TO 0.30 YIELDING SNOWFALL TOTALS OF 1-2 INCHES
UNDER THE HEAVIEST BAND OF SNOW. AT THIS POINT THE RAP 11.07 PLACES
THIS HEAVY BAND FROM CANBY MN EASTWARD THROUGH THE SOUTHERN
METRO...AND THEREFORE ALL THE HIRES MODELS THAT USE THE RAP FOR
THEIR INITIAL BOUNDARY CONDITIONS ARE SUBCONSCIOUSLY DRAWN TO THIS
CONCLUSION. HOWEVER...THE H850-700MB FGEN...WHICH AS OF EARLY THIS
MORNING MATCHES UP NICELY WITH THE ONGOING PRECIP...SHIFTS SOUTHEAST
FROM CANBY TO MANKATO AND OWATONNA. BASED ON THAT DIAGNOSTIC
TOOL...EXPECT THE PRECIP TO FALL TOWARD THE SOUTHERN SIDE OF THE
CURRENT MODEL GENERATED QPF FIELD. AT THIS POINT NOT ANTICIPATING
ANY ADVISORY CRITERIA SNOWFALL AMOUNTS...BUT EXPECT HEAVY WET SNOW
WITH 1/2 TO 1/4 MI VISIBILITY POSSIBLE AT TIMES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 345 AM CDT TUE MAR 11 2014
LOOKING AHEAD...COLD AIR WILL SURGE SOUTHWARD BEHIND THIS SYSTEM AS
IT STRENGTHENS INTO A MAJOR STORM OVER NEW ENGLAND. CLOSER TO HOME
TEMPERATURES WILL FALL BELOW FREEZING TONIGHT AND REMAIN THERE UNTIL
THURSDAY WHEN THE NEXT SHOT OF LEE-SIDE WARM AIR SPREADS ACROSS THE
REGION. THIS WILL BRING TEMPERATURES INTO THE 40S ONCE AGAIN...WITH
50S IN WESTERN MN. THERE IS A CHANCE FOR SOME LIGHT PRECIP AHEAD OF
THIS WARM AIR ADVECTION...MAINLY ALONG THE ST CROIX RIVER VALLEY.
THIS WARMUP WILL BE SHORT LIVED AS COLD AIR SPREADS SOUTHWARD AND
LASTS INTO NEXT WEEK. NO SIGNIFICANT PRECIPITATION IS EXPECTED UNTIL
THE NEXT STORM SYSTEM ARRIVES ON TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 626 AM CDT TUE MAR 11 2014
BESIDES KRWF...THE SNOW SHOULD LARGELY MISS THE TAF SITES. IT`S
EVEN UNCLEAR HOW MUCH SNOW WILL MIX WITH THE RAIN AT KRWF. MVFR
CEILINGS ARE STILL LIKELY ACROSS SOUTHERN MN AND WEST CENTRAL WI
TODAY WITH THE LIGHT RAIN...ESPECIALLY THIS MORNING AND EARLY
AFTERNOON. AIRPORTS SHOULD RETURN TO VFR LATE THIS AFTERNOON AFTER
THE PRECIP CLEARS THE AREA...WITH A POSSIBLE RETURN OF MVFR
CEILINGS. OVERALL...WEATHER IMPACTS WILL NOT BE GREAT TODAY EVEN
WITH THE PRECIP MOVING THROUGH.
KMSP...
WITH THE HEAVIER PRECIP GOING SOUTH OF THE AIRPORT AND THE
TEMPERATURE HOLDING STEADY IN THE MID TO UPPER 30S...WE THINK SNOW
IS LOOKING LESS LIKELY TODAY - PERHAPS JUST ONE HOUR OF A
RAIN/SNOW MIX LATE THIS MORNING. THE SNOW SHOULDN`T BE HEAVY
ENOUGH TO ACCUMULATE AND IT MAY NOT OCCUR AT ALL. MVFR CEILINGS
ARE JUST TO THE WEST OF THE AIRPORT...BUT BASES SHOULD REMAIN
ABOVE 2000 FT.
/OUTLOOK FOR KMSP/
WED...VFR. N WIND 8 KTS BCMG W.
THU...VFR. SW WIND 5-10 KTS.
FRI...VFR. W 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...JRB
AVIATION...CLF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
346 AM CDT TUE MAR 11 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT TUE MAR 11 2014
MOST SIGNIFICANT PRECIPITATION OVER THE NEXT 7 DAYS WILL FALL WITHIN
THE NEXT 12 HRS OF THIS DISCUSSION AS AN IMPRESSIVE FRONTGENETICALLY
DRIVEN BAND OF PRECIP BLOSSOMS ACROSS THE SOUTHERN HALF OF THE CWA
THIS MORNING. HIRES MODELS CONTINUE TO BE TOO COOL WITH THE LOW
LEVEL THERMAL FIELDS...AND THUS THEIR PTYPE ALGORITHMS ARE LIKELY
OVERDOING THE SNOWFALL ACROSS THE REGION DURING THE INITIAL
DEVELOPMENT EARLY THIS MORNING. HOWEVER...BUFR FORECAST SOUNDINGS
SHOW TREMENDOUS LIFT ALONG THE LOW/MID LEVEL FRONT AS INFERRED FROM
THE SHARP WIND SHIFT WITHIN THE H850-700 LAYER. ASIDE FROM THE
LOWEST FEW HUNDRED METERS THE ENTIRE SOUNDING IS BELOW FREEZING...SO
ANTICIPATING THAT THE RAIN WILL CHANGE OVER TO A RAIN SNOW MIX
AROUND 6-7AM...AND THEN QUICKLY OVER TO HEAVY WET SNOW AROUND MID
MORNING ACROSS SOUTHERN MN.
SNOW RATIOS WILL BE IN THE MID-SINGLE DIGITS...BUT QPF SHOULD EASILY
MANAGE AROUND 0.20 TO 0.30 YIELDING SNOWFALL TOTALS OF 1-2 INCHES
UNDER THE HEAVIEST BAND OF SNOW. AT THIS POINT THE RAP 11.07 PLACES
THIS HEAVY BAND FROM CANBY MN EASTWARD THROUGH THE SOUTHERN
METRO...AND THEREFORE ALL THE HIRES MODELS THAT USE THE RAP FOR
THEIR INITIAL BOUNDARY CONDITIONS ARE SUBCONSCIOUSLY DRAWN TO THIS
CONCLUSION. HOWEVER...THE H850-700MB FGEN...WHICH AS OF EARLY THIS
MORNING MATCHES UP NICELY WITH THE ONGOING PRECIP...SHIFTS SOUTHEAST
FROM CANBY TO MANKATO AND OWATONNA. BASED ON THAT DIAGNOSTIC
TOOL...EXPECT THE PRECIP TO FALL TOWARD THE SOUTHERN SIDE OF THE
CURRENT MODEL GENERATED QPF FIELD. AT THIS POINT NOT ANTICIPATING
ANY ADVISORY CRITERIA SNOWFALL AMOUNTS...BUT EXPECT HEAVY WET SNOW
WITH 1/2 TO 1/4 MI VISIBILITY POSSIBLE AT TIMES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 345 AM CDT TUE MAR 11 2014
LOOKING AHEAD...COLD AIR WILL SURGE SOUTHWARD BEHIND THIS SYSTEM AS
IT STRENGTHENS INTO A MAJOR STORM OVER NEW ENGLAND. CLOSER TO HOME
TEMPERATURES WILL FALL BELOW FREEZING TONIGHT AND REMAIN THERE UNTIL
THURSDAY WHEN THE NEXT SHOT OF LEE-SIDE WARM AIR SPREADS ACROSS THE
REGION. THIS WILL BRING TEMPERATURES INTO THE 40S ONCE AGAIN...WITH
50S IN WESTERN MN. THERE IS A CHANCE FOR SOME LIGHT PRECIP AHEAD OF
THIS WARM AIR ADVECTION...MAINLY ALONG THE ST CROIX RIVER VALLEY.
THIS WARMUP WILL BE SHORT LIVED AS COLD AIR SPREADS SOUTHWARD AND
LASTS INTO NEXT WEEK. NO SIGNIFICANT PRECIPITATION IS EXPECTED UNTIL
THE NEXT STORM SYSTEM ARRIVES ON TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1045 PM CDT MON MAR 10 2014
A NARROW BAND OF LIGHT RAIN WILL ENTER WEST CENTRAL MN NEAR THE
START OF THE TAFS AND WORK ESE INTO THE TWIN CITIES BEFORE
DAYBREAK AND INTO KEAU AROUND DAYBREAK. IT STILL LOOKS LIKE
KAXN...KSTC AND KRNH ARE GOING TO BE ON THE NORTHERN EDGE OF THE
PRECIPITATION SHIELD. KMSP AND KEAU ARE A LITTLE MORE IN LINE TO
RECEIVE A FEW HOURS OF RAIN AND SNOW. KRWF REMAINS THE SITE FOR
A FEW INCHES OF SNOW ACCUMULATION TUESDAY MORNING AS THE BAND OF
PRECIPITATION SINKS INTO SOUTHERN MINNESOTA. CEILINGS ARE EXPECTED
TO BECOME MVFR IN THE RAIN/SNOW MIX WITH MVFR OR LOWER VSBY. THE
BACK EDGE OF THE PRECIPITATION WILL MOVE SE OF THE TAF SITES EARLY
IN THE AFTERNOON WITH CEILINGS FORECAST BACK TO VFR. LIGHT WINDS
OVERNIGHT BECOMING N TO NW AT 12-15 KNOTS BY TUESDAY AFTERNOON
WITH GUSTS FROM 20 TO 25 KNOTS. WINDS DIMINISHING TUESDAY EVENING.
KMSP...LIGHT RAIN STILL EXPECTED TO BEGIN IN THE 09Z-10Z PERIOD
AND THEN MIX WITH SNOW AROUND 12Z WITH A PERIOD OF LIGHT SNOW
DURING THE MORNING. ACCUMULATIONS WILL BE LIGHT AND LESS THAN AN
INCH. IMPROVED CEILINGS TO VFR IN THE WAKE OF THE SNOW FOR TUESDAY
AFTERNOON. NORTHWEST WINDS WILL BE ON THE INCREASE AS WELL DURING
THE AFTERNOON WITH GUSTS TO AROUND 20 KNOTS.
/OUTLOOK FOR KMSP/
WED...VFR. N WIND 8 KTS BCMG W.
THU...VFR. SW WIND 5-10 KTS.
FRI...VFR. W 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...JRB
AVIATION...RAH
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1255 PM CDT TUE MAR 11 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM CDT TUE MAR 11 2014
THE MODEL CONSENSUS SHOWS A STRONG AREA OF 700-500MB
FRONTOGENESIS DEVELOPING ACROSS NERN NEB AROUND 18Z TODAY. THIS
FGEN IS EXPECTED TO PRODUCE A FAIRLY STRONG BAND OF WET SNOW WITH
HOURLY LIQUID RATES OF UP TO 0.10 INCHES. THE NAM RADAR PRODUCT
SHOWS THIS BAND SETTING UP FROM AROUND CHAMBERS TO BROKEN BOW AT
21Z WHICH MOVES QUICKLY EAST OF THE FCST AREA BY 00Z. THE NAM HAS
BEEN WOBBLING SOMEWHAT BUT THE CONCEPT OF FOLDED THETA E AND DEEP
LIFT IN THE DENDRITIC GROWTH ZONE CONTINUES. THE 05Z RAP MODEL
SETS IT UP FROM ONEILL TO SUTHERLAND. THE 00Z ECM FOLLOWS THE NAM
WHICH MATCHES THE MODEL CONSENSUS.
IN GENERAL...THE MODELS ARE CLUSTERING AROUND 0.20 INCHES OF LIQUID
FOR THIS EVENT ALONG HIGHWAY 83 BUT THEN SPREAD OUT TO THE EAST AS
SOME SIGNAL A WETTER EVENT AND OTHERS DRIER. THE MEDIAN QPF IN
CUSTER COUNTY LOOKS TO BE AROUND 0.30 INCHES.
GIVEN THE STRONG LIFT DEVELOPING...IT IS EXPECTED THERE WILL BE A
PERIOD OF MODERATE TO HEAVY SNOW DEVELOPING LASTING 1 OR 2 HOURS AT
THE MOST. THIS IS ABOUT A 6 HOUR PCPN EVENT WHICH EXITS THE FCST
AREA BY AROUND 00Z. THERE IS A SHORT PERIOD OF RAIN BEFORE CHANGE
OVER TO SNOW IN THE GFS AND NAM MODELS. H700MB TEMPERATURES COOL
VERY RAPIDLY BEHIND THE COLD FRONT MARKING THE ONSET OF PCPN AND
DEEP LIFT WILL AID THE DYNAMIC COOLING PROCESS.
AN 8 TO 1 SNOW WATER RATIO WAS USED UP NORTH DURING THE MORNING
HOURS WHICH WAS REDUCED TO 5 TO 1 DURING THE AFTERNOON. TEMPERATURES
FALL TO THE LOW TO MID 30S DURING THE HEAVIEST SNOW AND THEN WARM UP
ONCE THE SNOW LETS UP OR ENDS. THIS PRODUCED 1 TO 2 INCHES OF WET
SNOW.
THERE IS NO REASON TO UNDER ESTIMATE A SPRING STORM DURING THE 2ND
WEEK OF MARCH AND THE SYSTEM FORECAST TO DEVELOP TODAY IS EXPECTED
TO PRODUCE STRONG NORTH WINDS AS THE SFC LOW DEEPENS ACROSS EAST
CENTRAL KANSAS. ALL MODELS SHOW 500M AGL WINDS INCREASING TO OVER
30 KT WHICH TRANSLATES TO 30 MPH AT THE SFC. THE NAM...GFS
GUIDANCE...HRRR AND RAP MODELS ALL SHOW GUSTS TO NEAR 50 MPH
DEVELOPING ACROSS CNTL NEB NORTH OF THE SFC LOW LOCATED ACROSS KS
BY NOON TODAY. H850 WINDS INCREASE TO 45 TO 55 KT. THE WIND
FORECAST IS A CONSENSUS OF MODEL GUIDANCE OUTPUT AND DETERMINISTIC
SOLNS WHICH FOLLOWS THE MIDDLE ROAD. THE GFS AND THE ECM SPREAD
THESE STRONGER WINDS FURTHER NORTH AND WEST THAN THE OTHER MODELS.
A WEAK DISTURBANCE IS SHOWN BY THE MODELS TO MOVE ACROSS THE FCST
AREA TONIGHT. THIS COULD PRODUCE SNOW FLURRIES OR PERHAPS ISOLATED
SNOW SHOWER ACTIVITY AS IT TRANSLATES EAST ACROSS THE FCST AREA.
LAPSE RATES STEEPEN AND REMAIN MOIST SUPPORTING THIS FORECAST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 339 AM CDT TUE MAR 11 2014
THE SYSTEM BRINGING THE SNOW AND WIND TO THE FORECAST AREA TODAY AND
TONIGHT WILL MOVE EAST AND BE PAST THE LOCAL AREA BY 12Z WEDNESDAY.
THIS WILL PUT NEBRASKA UNDER SUBSIDENT AIR WEDNESDAY AND WITH DRY
AIR ADVECTING IN EXPECTING MOSTLY SUNNY SKIES. ALTHOUGH NOT
EXPECTING ADVISORY LEVEL WINDS WEDNESDAY...SIGNALS ARE COMING
TOGETHER FOR A BREEZY DAY. MODELS ARE SHOWING A SECONDARY PV MAX
DROPPING SOUTH ACROSS CENTRAL NEBRASKA THROUGH THE DAY...TO HELP
ENHANCE WINDS ALOFT AND WITH STEEP SURFACE TO 700MB LAPSE RATES
CONFIDENCE INCREASES ON BREEZY CONDITIONS. SOUNDINGS SHOW THE MIXED
LAYER BETWEEN 700MB AND 800MB AND LOOKING AT MAXIMUM WINDS IN THAT
LAYER UP TO 35KTS SO DECIDED TO INCREASE WINDS DURING THE DAY.
TEMPERATURES ALOFT DON/T CHANGE SIGNIFICANTLY ON WEDNESDAY SO
LOOKING AT AN ADIABATIC PROFILE...HIGHS WOULD BE IN THE 40S FOR MOST
LOCATIONS. HOWEVER...MODELS HAVE BEEN CONSISTENTLY A BIT COOL FOR
TEMPERATURES AND WITH SUNNY SKIES THINK MOST AREAS WILL WARM A BIT
MORE THAN THE DETERMINISTIC MODELS ARE INDICATING.
DRY WEATHER IS EXPECTED THROUGH FRIDAY NIGHT AS NO SIGNIFICANT
SYSTEMS ARE SET TO MOVE ACROSS THE CENTRAL PLAINS. AN UPPER LEVEL
LOW WILL STAY FAIRLY STATIONARY OVER THE SOUTHWEST THROUGH
FRIDAY...WHILE THE NORTHERN STREAM WILL KEEP NORTHWEST FLOW ACROSS
THE AREA. THERE WILL BE AN APPROACHING SHORTWAVE TROUGH ON THURSDAY
AS IT WILL BE MOVING OVER THE NORTHERN ROCKIES. THERE IS A BIT OF
UNCERTAINTY ON HOW AMPLIFIED THIS SHORTWAVE TROUGH WILL BE...WHICH
IMPACTS HOW STRONG THE SURFACE LOW WILL BECOME AND THEN HOW MUCH
WARM AIR CAN BE PULLED NORTHWARD. TOOK A MIDDLE OF THE ROAD APPROACH
FOR HIGH TEMPERATURES THURSDAY...WITH FORECAST HIGHS IN THE UPPER
50S AND 60S. IF THE SYSTEM BECOMES A BIT STRONGER...TEMPERATURES
WILL LIKELY NEED TO BE RAISED FOR THURSDAY.
THE COLD FRONT ASSOCIATED WITH THIS UPPER LEVEL SYSTEM WILL PASS
ACROSS NEBRASKA THURSDAY AFTERNOON AND EVENING. ALTHOUGH THERE
CONTINUES TO BE QUITE A BIT OF DISAGREEMENT IN MODEL SOLUTIONS ON
WHERE THE MAIN ENERGY WITH THIS SYSTEM WILL PASS...IT DOES APPEAR
FAIRLY CERTAIN THAT IT WILL BE WELL NORTH OF THE FORECAST AREA. WITH
THE MAJORITY OF THE MOISTURE ACROSS THE NORTH STAYING NEAR THE LOW
CENTER...FOR PRECIPITATION TO OCCUR WOULD NEED A MOISTURE SOURCE
FROM THE SOUTH TO GET THIS TO HAPPEN AS THE FRONT MOVES THROUGH.
HOWEVER THE UPPER LOW TO THE SOUTHWEST WILL LIKELY PROHIBIT MUCH
MOISTURE TRANSPORT INTO THE AREA FROM THE SOUTH. ONE THING THAT
DOES LOOK POSSIBLE IS STRONG WINDS THURSDAY NIGHT. WITH THE AREA
STAYING IN A LOCATION WITH DRY AIR...WHEN THE AIRMASS BECOMES
SUBSIDENT BEHIND THE FRONT...DOWNWARD MOTION WILL BE PROMOTED.
ALTHOUGH TIMING IS NIGHT...WHICH ISN/T AS FAVORABLE FOR STRONGER
WINDS...WILL NEED TO CONTINUE TO WATCH THIS TIME-FRAME IN THE NEXT
FEW DAYS CONCERNING WINDS.
THE MODELS REALLY BEGIN TO DIVERGE BEGINNING SATURDAY AS THEY SEEM
TO BE HAVING PROBLEMS HANDLING THE SOUTHWEST UPPER LOW. ONE THING
THEY DO ALL AGREE ON IS THAT STRONG RIDGING WILL BUILD
IN...SOMEWHERE ACROSS THE WESTERN HALF OF THE COUNTRY INTO THE FIRST
PART OF NEXT WEEK.
DESPITE THE MODEL DIFFERENCES...THEY ALSO ARE INDICATING THE PATTERN
ALOFT BECOMING MORE AMPLIFIED AND DIG A SHORTWAVE TROUGH SOUTH ALONG
THE LEE-SIDE OF THE ROCKY MOUNTAINS OVER THE WEEKEND. CONTINUE TO
HAVE PRECIPITATION CHANCES THROUGH MUCH OF THE WEEKEND...WITH BOTH
RAIN AND SNOW LOOKING POSSIBLE. TEMPERATURE PROFILES SHOW
PRECIPITATION TYPE AS RAIN ON SATURDAY...THEN SWITCHING TO RAIN/SNOW
AND SNOW SATURDAY NIGHT...THEN BACK TO RAIN ON SUNDAY. THIS MAY NOT
BE REAL LIKELY...AS THERE WON/T BE THAT GREAT AMOUNT OF TIME WITH
RAIN AND SNOW...BUT WITH CONCERN OVER TIMING AND LOCATION OF THE
PRECIPITATION...DID NOT HAVE THE CONFIDENCE YET TO NAIL DOWN A
PARTICULAR PRECIPITATION TYPE.
THE VERY END OF THE FORECAST PERIOD LOOKS INTERESTING...WITH A
STRONG COLD FRONT TO PASS MONDAY NIGHT AND TUESDAY. DYNAMICS WITH
THIS SYSTEM ARE PRETTY STRONG...WHICH COULD LEAD TO VERY WARM
TEMPERATURES MONDAY...THEN CHANCES FOR PRECIPITATION MONDAY NIGHT
AND TUESDAY...AND STRONG WINDS TUESDAY. DIDN/T GO TOO WARM WITH
TEMPERATURES FOR MONDAY AT THIS TIME AS CONFIDENCE ON FORECASTING
THE HIGHS THE DETERMINISTIC MODELS SHOW AT THIS TIME IS QUITE
LOW...BUT IT BEARS WATCHING OVER THE COMING DAYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1252 PM CDT TUE MAR 11 2014
COLD FRONT IS THROUGH THE AREA......WITH NORTHERLY WIND GUSTS IN
THE 20 TO 35 KT RANGE. PRECIP CHANCES CONTINUE THIS
AFTERNOON...WITH HEAVIER MOISTURE CHANCES ACROSS SW NEB. TEMPS
ARE IN THE MID 30S...SO PRECIP TYPE IS A MIX OF RAIN AND SNOW OR
ALL SNOW. CONDITIONS WILL START TO IMPROVE ACROSS THE
NORTH...LATER THIS AFTERNOON INTO THE EVENING. MEANWHILE FUTHER
SOUTH...LIGHT RAIN/DRIZZLE WILL CHANGE OVER TO MORE SNOW AS A BAND
DEVELOPS FOR THE AFTERNOON. BY THIS EVENING THIS BAND WILL SHIFT
SOUTH. MVFR/IFR CONDITIONS WILL IMPROVE TO VFR OVERNIGHT ALTHOUGH
A WEAK DISTURBANCE WILL BRING A SLGHT CHC FOR FLURRIES/SPRINKLES
EARLY TONIGHT ACROSS MUCH OF THE AREA. TOMORROW VFR AND BREEZY
CONDITIONS CAN BE ANTICIPATED.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 8 PM CDT /7 PM MDT/ THIS EVENING FOR
NEZ025>029-036>038-057>059-069>071.
&&
$$
SHORT TERM...CDC
LONG TERM...BROOKS
AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
623 AM CDT TUE MAR 11 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM CDT TUE MAR 11 2014
THE MODEL CONSENSUS SHOWS A STRONG AREA OF 700-500MB
FRONTOGENESIS DEVELOPING ACROSS NERN NEB AROUND 18Z TODAY. THIS
FGEN IS EXPECTED TO PRODUCE A FAIRLY STRONG BAND OF WET SNOW WITH
HOURLY LIQUID RATES OF UP TO 0.10 INCHES. THE NAM RADAR PRODUCT
SHOWS THIS BAND SETTING UP FROM AROUND CHAMBERS TO BROKEN BOW AT
21Z WHICH MOVES QUICKLY EAST OF THE FCST AREA BY 00Z. THE NAM HAS
BEEN WOBBLING SOMEWHAT BUT THE CONCEPT OF FOLDED THETA E AND DEEP
LIFT IN THE DENDRITIC GROWTH ZONE CONTINUES. THE 05Z RAP MODEL
SETS IT UP FROM ONEILL TO SUTHERLAND. THE 00Z ECM FOLLOWS THE NAM
WHICH MATCHES THE MODEL CONSENSUS.
IN GENERAL...THE MODELS ARE CLUSTERING AROUND 0.20 INCHES OF LIQUID
FOR THIS EVENT ALONG HIGHWAY 83 BUT THEN SPREAD OUT TO THE EAST AS
SOME SIGNAL A WETTER EVENT AND OTHERS DRIER. THE MEDIAN QPF IN
CUSTER COUNTY LOOKS TO BE AROUND 0.30 INCHES.
GIVEN THE STRONG LIFT DEVELOPING...IT IS EXPECTED THERE WILL BE A
PERIOD OF MODERATE TO HEAVY SNOW DEVELOPING LASTING 1 OR 2 HOURS AT
THE MOST. THIS IS ABOUT A 6 HOUR PCPN EVENT WHICH EXITS THE FCST
AREA BY AROUND 00Z. THERE IS A SHORT PERIOD OF RAIN BEFORE CHANGE
OVER TO SNOW IN THE GFS AND NAM MODELS. H700MB TEMPERATURES COOL
VERY RAPIDLY BEHIND THE COLD FRONT MARKING THE ONSET OF PCPN AND
DEEP LIFT WILL AID THE DYNAMIC COOLING PROCESS.
AN 8 TO 1 SNOW WATER RATIO WAS USED UP NORTH DURING THE MORNING
HOURS WHICH WAS REDUCED TO 5 TO 1 DURING THE AFTERNOON. TEMPERATURES
FALL TO THE LOW TO MID 30S DURING THE HEAVIEST SNOW AND THEN WARM UP
ONCE THE SNOW LETS UP OR ENDS. THIS PRODUCED 1 TO 2 INCHES OF WET
SNOW.
THERE IS NO REASON TO UNDER ESTIMATE A SPRING STORM DURING THE 2ND
WEEK OF MARCH AND THE SYSTEM FORECAST TO DEVELOP TODAY IS EXPECTED
TO PRODUCE STRONG NORTH WINDS AS THE SFC LOW DEEPENS ACROSS EAST
CENTRAL KANSAS. ALL MODELS SHOW 500M AGL WINDS INCREASING TO OVER
30 KT WHICH TRANSLATES TO 30 MPH AT THE SFC. THE NAM...GFS
GUIDANCE...HRRR AND RAP MODELS ALL SHOW GUSTS TO NEAR 50 MPH
DEVELOPING ACROSS CNTL NEB NORTH OF THE SFC LOW LOCATED ACROSS KS
BY NOON TODAY. H850 WINDS INCREASE TO 45 TO 55 KT. THE WIND
FORECAST IS A CONSENSUS OF MODEL GUIDANCE OUTPUT AND DETERMINISTIC
SOLNS WHICH FOLLOWS THE MIDDLE ROAD. THE GFS AND THE ECM SPREAD
THESE STRONGER WINDS FURTHER NORTH AND WEST THAN THE OTHER MODELS.
A WEAK DISTURBANCE IS SHOWN BY THE MODELS TO MOVE ACROSS THE FCST
AREA TONIGHT. THIS COULD PRODUCE SNOW FLURRIES OR PERHAPS ISOLATED
SNOW SHOWER ACTIVITY AS IT TRANSLATES EAST ACROSS THE FCST AREA.
LAPSE RATES STEEPEN AND REMAIN MOIST SUPPORTING THIS FORECAST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 339 AM CDT TUE MAR 11 2014
THE SYSTEM BRINGING THE SNOW AND WIND TO THE FORECAST AREA TODAY AND
TONIGHT WILL MOVE EAST AND BE PAST THE LOCAL AREA BY 12Z WEDNESDAY.
THIS WILL PUT NEBRASKA UNDER SUBSIDENT AIR WEDNESDAY AND WITH DRY
AIR ADVECTING IN EXPECTING MOSTLY SUNNY SKIES. ALTHOUGH NOT
EXPECTING ADVISORY LEVEL WINDS WEDNESDAY...SIGNALS ARE COMING
TOGETHER FOR A BREEZY DAY. MODELS ARE SHOWING A SECONDARY PV MAX
DROPPING SOUTH ACROSS CENTRAL NEBRASKA THROUGH THE DAY...TO HELP
ENHANCE WINDS ALOFT AND WITH STEEP SURFACE TO 700MB LAPSE RATES
CONFIDENCE INCREASES ON BREEZY CONDITIONS. SOUNDINGS SHOW THE MIXED
LAYER BETWEEN 700MB AND 800MB AND LOOKING AT MAXIMUM WINDS IN THAT
LAYER UP TO 35KTS SO DECIDED TO INCREASE WINDS DURING THE DAY.
TEMPERATURES ALOFT DON/T CHANGE SIGNIFICANTLY ON WEDNESDAY SO
LOOKING AT AN ADIABATIC PROFILE...HIGHS WOULD BE IN THE 40S FOR MOST
LOCATIONS. HOWEVER...MODELS HAVE BEEN CONSISTENTLY A BIT COOL FOR
TEMPERATURES AND WITH SUNNY SKIES THINK MOST AREAS WILL WARM A BIT
MORE THAN THE DETERMINISTIC MODELS ARE INDICATING.
DRY WEATHER IS EXPECTED THROUGH FRIDAY NIGHT AS NO SIGNIFICANT
SYSTEMS ARE SET TO MOVE ACROSS THE CENTRAL PLAINS. AN UPPER LEVEL
LOW WILL STAY FAIRLY STATIONARY OVER THE SOUTHWEST THROUGH
FRIDAY...WHILE THE NORTHERN STREAM WILL KEEP NORTHWEST FLOW ACROSS
THE AREA. THERE WILL BE AN APPROACHING SHORTWAVE TROUGH ON THURSDAY
AS IT WILL BE MOVING OVER THE NORTHERN ROCKIES. THERE IS A BIT OF
UNCERTAINTY ON HOW AMPLIFIED THIS SHORTWAVE TROUGH WILL BE...WHICH
IMPACTS HOW STRONG THE SURFACE LOW WILL BECOME AND THEN HOW MUCH
WARM AIR CAN BE PULLED NORTHWARD. TOOK A MIDDLE OF THE ROAD APPROACH
FOR HIGH TEMPERATURES THURSDAY...WITH FORECAST HIGHS IN THE UPPER
50S AND 60S. IF THE SYSTEM BECOMES A BIT STRONGER...TEMPERATURES
WILL LIKELY NEED TO BE RAISED FOR THURSDAY.
THE COLD FRONT ASSOCIATED WITH THIS UPPER LEVEL SYSTEM WILL PASS
ACROSS NEBRASKA THURSDAY AFTERNOON AND EVENING. ALTHOUGH THERE
CONTINUES TO BE QUITE A BIT OF DISAGREEMENT IN MODEL SOLUTIONS ON
WHERE THE MAIN ENERGY WITH THIS SYSTEM WILL PASS...IT DOES APPEAR
FAIRLY CERTAIN THAT IT WILL BE WELL NORTH OF THE FORECAST AREA. WITH
THE MAJORITY OF THE MOISTURE ACROSS THE NORTH STAYING NEAR THE LOW
CENTER...FOR PRECIPITATION TO OCCUR WOULD NEED A MOISTURE SOURCE
FROM THE SOUTH TO GET THIS TO HAPPEN AS THE FRONT MOVES THROUGH.
HOWEVER THE UPPER LOW TO THE SOUTHWEST WILL LIKELY PROHIBIT MUCH
MOISTURE TRANSPORT INTO THE AREA FROM THE SOUTH. ONE THING THAT
DOES LOOK POSSIBLE IS STRONG WINDS THURSDAY NIGHT. WITH THE AREA
STAYING IN A LOCATION WITH DRY AIR...WHEN THE AIRMASS BECOMES
SUBSIDENT BEHIND THE FRONT...DOWNWARD MOTION WILL BE PROMOTED.
ALTHOUGH TIMING IS NIGHT...WHICH ISN/T AS FAVORABLE FOR STRONGER
WINDS...WILL NEED TO CONTINUE TO WATCH THIS TIME-FRAME IN THE NEXT
FEW DAYS CONCERNING WINDS.
THE MODELS REALLY BEGIN TO DIVERGE BEGINNING SATURDAY AS THEY SEEM
TO BE HAVING PROBLEMS HANDLING THE SOUTHWEST UPPER LOW. ONE THING
THEY DO ALL AGREE ON IS THAT STRONG RIDGING WILL BUILD
IN...SOMEWHERE ACROSS THE WESTERN HALF OF THE COUNTRY INTO THE FIRST
PART OF NEXT WEEK.
DESPITE THE MODEL DIFFERENCES...THEY ALSO ARE INDICATING THE PATTERN
ALOFT BECOMING MORE AMPLIFIED AND DIG A SHORTWAVE TROUGH SOUTH ALONG
THE LEE-SIDE OF THE ROCKY MOUNTAINS OVER THE WEEKEND. CONTINUE TO
HAVE PRECIPITATION CHANCES THROUGH MUCH OF THE WEEKEND...WITH BOTH
RAIN AND SNOW LOOKING POSSIBLE. TEMPERATURE PROFILES SHOW
PRECIPITATION TYPE AS RAIN ON SATURDAY...THEN SWITCHING TO RAIN/SNOW
AND SNOW SATURDAY NIGHT...THEN BACK TO RAIN ON SUNDAY. THIS MAY NOT
BE REAL LIKELY...AS THERE WON/T BE THAT GREAT AMOUNT OF TIME WITH
RAIN AND SNOW...BUT WITH CONCERN OVER TIMING AND LOCATION OF THE
PRECIPITATION...DID NOT HAVE THE CONFIDENCE YET TO NAIL DOWN A
PARTICULAR PRECIPITATION TYPE.
THE VERY END OF THE FORECAST PERIOD LOOKS INTERESTING...WITH A
STRONG COLD FRONT TO PASS MONDAY NIGHT AND TUESDAY. DYNAMICS WITH
THIS SYSTEM ARE PRETTY STRONG...WHICH COULD LEAD TO VERY WARM
TEMPERATURES MONDAY...THEN CHANCES FOR PRECIPITATION MONDAY NIGHT
AND TUESDAY...AND STRONG WINDS TUESDAY. DIDN/T GO TOO WARM WITH
TEMPERATURES FOR MONDAY AT THIS TIME AS CONFIDENCE ON FORECASTING
THE HIGHS THE DETERMINISTIC MODELS SHOW AT THIS TIME IS QUITE
LOW...BUT IT BEARS WATCHING OVER THE COMING DAYS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 621 AM CDT TUE MAR 11 2014
AS A STORM SYSTEM MAKES ITS WAY THROUGH THE CENTRAL PLAINS...WIND
350-020 AT 17-27G30-35KT. BY 00Z...THE WIND IS EXPECTED TO LOSE ITS
GUSTINESS WITH SUSTAINED WIND DECREASING TO 12KT. WIDESPREAD
RAIN...CHANGING TO SNOW...IS EXPECTED IN NORTHERN NEBRASKA BY 14Z
AND WILL SPREAD TO CENTRAL AND SOUTHWEST NEBRASKA BY 17Z. VISIBILITY
AS LOW AS 1/2SM CAN BE EXPECTED WITH CEILING 700-1500 FEET AGL. SNOW
WILL END BY LATE AFTERNOON.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 10 AM CDT /9 AM MDT/ THIS MORNING TO 8 PM CDT
/7 PM MDT/ THIS EVENING FOR NEZ025>029-036>038-057>059-069>071.
&&
$$
SHORT TERM...CDC
LONG TERM...BROOKS
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
339 AM CDT TUE MAR 11 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM CDT TUE MAR 11 2014
THE MODEL CONSENSUS SHOWS A STRONG AREA OF 700-500MB
FRONTOGENESIS DEVELOPING ACROSS NERN NEB AROUND 18Z TODAY. THIS
FGEN IS EXPECTED TO PRODUCE A FAIRLY STRONG BAND OF WET SNOW WITH
HOURLY LIQUID RATES OF UP TO 0.10 INCHES. THE NAM RADAR PRODUCT
SHOWS THIS BAND SETTING UP FROM AROUND CHAMBERS TO BROKEN BOW AT
21Z WHICH MOVES QUICKLY EAST OF THE FCST AREA BY 00Z. THE NAM HAS
BEEN WOBBLING SOMEWHAT BUT THE CONCEPT OF FOLDED THETA E AND DEEP
LIFT IN THE DENDRITIC GROWTH ZONE CONTINUES. THE 05Z RAP MODEL
SETS IT UP FROM ONEILL TO SUTHERLAND. THE 00Z ECM FOLLOWS THE NAM
WHICH MATCHES THE MODEL CONSENSUS.
IN GENERAL...THE MODELS ARE CLUSTERING AROUND 0.20 INCHES OF LIQUID
FOR THIS EVENT ALONG HIGHWAY 83 BUT THEN SPREAD OUT TO THE EAST AS
SOME SIGNAL A WETTER EVENT AND OTHERS DRIER. THE MEDIAN QPF IN
CUSTER COUNTY LOOKS TO BE AROUND 0.30 INCHES.
GIVEN THE STRONG LIFT DEVELOPING...IT IS EXPECTED THERE WILL BE A
PERIOD OF MODERATE TO HEAVY SNOW DEVELOPING LASTING 1 OR 2 HOURS AT
THE MOST. THIS IS ABOUT A 6 HOUR PCPN EVENT WHICH EXITS THE FCST
AREA BY AROUND 00Z. THERE IS A SHORT PERIOD OF RAIN BEFORE CHANGE
OVER TO SNOW IN THE GFS AND NAM MODELS. H700MB TEMPERATURES COOL
VERY RAPIDLY BEHIND THE COLD FRONT MARKING THE ONSET OF PCPN AND
DEEP LIFT WILL AID THE DYNAMIC COOLING PROCESS.
AN 8 TO 1 SNOW WATER RATIO WAS USED UP NORTH DURING THE MORNING
HOURS WHICH WAS REDUCED TO 5 TO 1 DURING THE AFTERNOON. TEMPERATURES
FALL TO THE LOW TO MID 30S DURING THE HEAVIEST SNOW AND THEN WARM UP
ONCE THE SNOW LETS UP OR ENDS. THIS PRODUCED 1 TO 2 INCHES OF WET
SNOW.
THERE IS NO REASON TO UNDER ESTIMATE A SPRING STORM DURING THE 2ND
WEEK OF MARCH AND THE SYSTEM FORECAST TO DEVELOP TODAY IS EXPECTED
TO PRODUCE STRONG NORTH WINDS AS THE SFC LOW DEEPENS ACROSS EAST
CENTRAL KANSAS. ALL MODELS SHOW 500M AGL WINDS INCREASING TO OVER
30 KT WHICH TRANSLATES TO 30 MPH AT THE SFC. THE NAM...GFS
GUIDANCE...HRRR AND RAP MODELS ALL SHOW GUSTS TO NEAR 50 MPH
DEVELOPING ACROSS CNTL NEB NORTH OF THE SFC LOW LOCATED ACROSS KS
BY NOON TODAY. H850 WINDS INCREASE TO 45 TO 55 KT. THE WIND
FORECAST IS A CONSENSUS OF MODEL GUIDANCE OUTPUT AND DETERMINISTIC
SOLNS WHICH FOLLOWS THE MIDDLE ROAD. THE GFS AND THE ECM SPREAD
THESE STRONGER WINDS FURTHER NORTH AND WEST THAN THE OTHER MODELS.
A WEAK DISTURBANCE IS SHOWN BY THE MODELS TO MOVE ACROSS THE FCST
AREA TONIGHT. THIS COULD PRODUCE SNOW FLURRIES OR PERHAPS ISOLATED
SNOW SHOWER ACTIVITY AS IT TRANSLATES EAST ACROSS THE FCST AREA.
LAPSE RATES STEEPEN AND REMAIN MOIST SUPPORTING THIS FORECAST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 339 AM CDT TUE MAR 11 2014
THE SYSTEM BRINGING THE SNOW AND WIND TO THE FORECAST AREA TODAY AND
TONIGHT WILL MOVE EAST AND BE PAST THE LOCAL AREA BY 12Z WEDNESDAY.
THIS WILL PUT NEBRASKA UNDER SUBSIDENT AIR WEDNESDAY AND WITH DRY
AIR ADVECTING IN EXPECTING MOSTLY SUNNY SKIES. ALTHOUGH NOT
EXPECTING ADVISORY LEVEL WINDS WEDNESDAY...SIGNALS ARE COMING
TOGETHER FOR A BREEZY DAY. MODELS ARE SHOWING A SECONDARY PV MAX
DROPPING SOUTH ACROSS CENTRAL NEBRASKA THROUGH THE DAY...TO HELP
ENHANCE WINDS ALOFT AND WITH STEEP SURFACE TO 700MB LAPSE RATES
CONFIDENCE INCREASES ON BREEZY CONDITIONS. SOUNDINGS SHOW THE MIXED
LAYER BETWEEN 700MB AND 800MB AND LOOKING AT MAXIMUM WINDS IN THAT
LAYER UP TO 35KTS SO DECIDED TO INCREASE WINDS DURING THE DAY.
TEMPERATURES ALOFT DON/T CHANGE SIGNIFICANTLY ON WEDNESDAY SO
LOOKING AT AN ADIABATIC PROFILE...HIGHS WOULD BE IN THE 40S FOR MOST
LOCATIONS. HOWEVER...MODELS HAVE BEEN CONSISTENTLY A BIT COOL FOR
TEMPERATURES AND WITH SUNNY SKIES THINK MOST AREAS WILL WARM A BIT
MORE THAN THE DETERMINISTIC MODELS ARE INDICATING.
DRY WEATHER IS EXPECTED THROUGH FRIDAY NIGHT AS NO SIGNIFICANT
SYSTEMS ARE SET TO MOVE ACROSS THE CENTRAL PLAINS. AN UPPER LEVEL
LOW WILL STAY FAIRLY STATIONARY OVER THE SOUTHWEST THROUGH
FRIDAY...WHILE THE NORTHERN STREAM WILL KEEP NORTHWEST FLOW ACROSS
THE AREA. THERE WILL BE AN APPROACHING SHORTWAVE TROUGH ON THURSDAY
AS IT WILL BE MOVING OVER THE NORTHERN ROCKIES. THERE IS A BIT OF
UNCERTAINTY ON HOW AMPLIFIED THIS SHORTWAVE TROUGH WILL BE...WHICH
IMPACTS HOW STRONG THE SURFACE LOW WILL BECOME AND THEN HOW MUCH
WARM AIR CAN BE PULLED NORTHWARD. TOOK A MIDDLE OF THE ROAD APPROACH
FOR HIGH TEMPERATURES THURSDAY...WITH FORECAST HIGHS IN THE UPPER
50S AND 60S. IF THE SYSTEM BECOMES A BIT STRONGER...TEMPERATURES
WILL LIKELY NEED TO BE RAISED FOR THURSDAY.
THE COLD FRONT ASSOCIATED WITH THIS UPPER LEVEL SYSTEM WILL PASS
ACROSS NEBRASKA THURSDAY AFTERNOON AND EVENING. ALTHOUGH THERE
CONTINUES TO BE QUITE A BIT OF DISAGREEMENT IN MODEL SOLUTIONS ON
WHERE THE MAIN ENERGY WITH THIS SYSTEM WILL PASS...IT DOES APPEAR
FAIRLY CERTAIN THAT IT WILL BE WELL NORTH OF THE FORECAST AREA. WITH
THE MAJORITY OF THE MOISTURE ACROSS THE NORTH STAYING NEAR THE LOW
CENTER...FOR PRECIPITATION TO OCCUR WOULD NEED A MOISTURE SOURCE
FROM THE SOUTH TO GET THIS TO HAPPEN AS THE FRONT MOVES THROUGH.
HOWEVER THE UPPER LOW TO THE SOUTHWEST WILL LIKELY PROHIBIT MUCH
MOISTURE TRANSPORT INTO THE AREA FROM THE SOUTH. ONE THING THAT
DOES LOOK POSSIBLE IS STRONG WINDS THURSDAY NIGHT. WITH THE AREA
STAYING IN A LOCATION WITH DRY AIR...WHEN THE AIRMASS BECOMES
SUBSIDENT BEHIND THE FRONT...DOWNWARD MOTION WILL BE PROMOTED.
ALTHOUGH TIMING IS NIGHT...WHICH ISN/T AS FAVORABLE FOR STRONGER
WINDS...WILL NEED TO CONTINUE TO WATCH THIS TIME-FRAME IN THE NEXT
FEW DAYS CONCERNING WINDS.
THE MODELS REALLY BEGIN TO DIVERGE BEGINNING SATURDAY AS THEY SEEM
TO BE HAVING PROBLEMS HANDLING THE SOUTHWEST UPPER LOW. ONE THING
THEY DO ALL AGREE ON IS THAT STRONG RIDGING WILL BUILD
IN...SOMEWHERE ACROSS THE WESTERN HALF OF THE COUNTRY INTO THE FIRST
PART OF NEXT WEEK.
DESPITE THE MODEL DIFFERENCES...THEY ALSO ARE INDICATING THE PATTERN
ALOFT BECOMING MORE AMPLIFIED AND DIG A SHORTWAVE TROUGH SOUTH ALONG
THE LEE-SIDE OF THE ROCKY MOUNTAINS OVER THE WEEKEND. CONTINUE TO
HAVE PRECIPITATION CHANCES THROUGH MUCH OF THE WEEKEND...WITH BOTH
RAIN AND SNOW LOOKING POSSIBLE. TEMPERATURE PROFILES SHOW
PRECIPITATION TYPE AS RAIN ON SATURDAY...THEN SWITCHING TO RAIN/SNOW
AND SNOW SATURDAY NIGHT...THEN BACK TO RAIN ON SUNDAY. THIS MAY NOT
BE REAL LIKELY...AS THERE WON/T BE THAT GREAT AMOUNT OF TIME WITH
RAIN AND SNOW...BUT WITH CONCERN OVER TIMING AND LOCATION OF THE
PRECIPITATION...DID NOT HAVE THE CONFIDENCE YET TO NAIL DOWN A
PARTICULAR PRECIPITATION TYPE.
THE VERY END OF THE FORECAST PERIOD LOOKS INTERESTING...WITH A
STRONG COLD FRONT TO PASS MONDAY NIGHT AND TUESDAY. DYNAMICS WITH
THIS SYSTEM ARE PRETTY STRONG...WHICH COULD LEAD TO VERY WARM
TEMPERATURES MONDAY...THEN CHANCES FOR PRECIPITATION MONDAY NIGHT
AND TUESDAY...AND STRONG WINDS TUESDAY. DIDN/T GO TOO WARM WITH
TEMPERATURES FOR MONDAY AT THIS TIME AS CONFIDENCE ON FORECASTING
THE HIGHS THE DETERMINISTIC MODELS SHOW AT THIS TIME IS QUITE
LOW...BUT IT BEARS WATCHING OVER THE COMING DAYS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1220 AM CDT TUE MAR 11 2014
A BANDED AREA OF IFR/LIFR IN SNOW IS EXPECTED TO DEVELOP ACROSS
THE NORTH TOWARD 12Z TUESDAY. THIS BAND OF IFR/LIFR IS EXPECTED
MOVE SOUTH THROUGH THE FCST AREA DURING THE LATE MORNING AND
AFTERNOON WITH FLIGHT CONDITIONS IMPROVING IN THE NORTH DURING THE
AFTN.
SCATTERED MVFR IS POSSIBLE TUESDAY EVENING AS A WEAK DISTURBANCE
MOVES ACROSS THE FCST AREA. ISOLATED FLURRIES MAY ACCOMPANY THE
DISTURBANCE AND PRODUCE MVFR CIGS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 10 AM CDT /9 AM MDT/ THIS MORNING TO 8 PM CDT
/7 PM MDT/ THIS EVENING FOR NEZ025>029-036>038-057>059-069>071.
&&
$$
SHORT TERM...CDC
LONG TERM...BROOKS
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1247 AM CDT TUE MAR 11 2014
.UPDATE...
ISSUED AT 1247 AM CDT TUE MAR 11 2014
THERE IS NO REASON TO UNDER ESTIMATE A SPRING STORM DURING THE 2ND
WEEK OF MARCH AND THE SYSTEM FORECAST TO DEVELOP TODAY IS EXPECTED
TO PRODUCE STRONG NORTH WINDS AS THE SFC LOW DEEPENS ACROSS EAST
CENTRAL KANSAS. ALL MODELS SHOW 500M AGL WINDS INCREASING TO OVER
30 KT WHICH TRANSLATES TO 30 MPH AT THE SFC. THE NAM...GFS
GUIDANCE...HRRR AND RAP MODELS ALL SHOW GUSTS TO NEAR 50 MPH
DEVELOPING ACROSS CNTL NEB NORTH OF THE SFC LOW LOCATED ACROSS KS
BY NOON TODAY. H850 WINDS INCREASE TO 45 TO 55 KT. THE WIND
FORECAST IS A CONSENSUS OF MODEL GUIDANCE OUTPUT AND DETERMINISTIC
SOLNS WHICH FOLLOWS THE MIDDLE ROAD. THE GFS SPREADS THESE STRONGER
WINDS FURTHER NORTH AND WEST THAN THE OTHER MODELS.
A WIND ADVISORY IS IN PLACE TODAY FOR PARTS OF SWRN AND SCNTL NEB.
UPDATE ISSUED AT 1220 AM CDT TUE MAR 11 2014
A WIND ADVISORY WILL BE ISSUED SHORTLY FOR SCNTL AND SWRN NEB.
UPDATE ISSUED AT 636 PM CDT MON MAR 10 2014
THE 18Z RUNS OF THE NAM AND GFS ARE GETTING MORE AGRESSIVE WITH
THE FGEN DROPPING INTO NCNTL NEB EARLY TUESDAY. THE GFS IS FARTHER
WEST FOCUSING ACROSS NWRN NEB WHILE THE NAM FAVORS PINE RIDGE AND
THE WRN SANDHILLS. THE NAM ACTUALLY PRODUCES OVER 1/2 INCH OF
QPF IN THAT REGION AS FOLDED THETA E DEVELOPS ALONG WITH DEEP
LIFT IN THE SNOW GROWTH ZONE...-12C TO -18C. THE RAIN CHANGES
QUICKLY TO SNOW ACROSS THE NORTHWEST DURING THE EARLY MORNING
HOURS IN THIS ZONE OF DEEP LIFT.
A NEW FORECAST IS OUT WHICH AFFECTS THE AREAS ALONG AND NORTH OF
NEBRASKA HIGHWAY 2 WEST OF THEDFORD. THE FORECAST ADDS WEIGHT TO
THE GFS AND NAM QPF FORECAST BUT STILL BLENDS THE SREF AND THE DRIER
ECM AND GEM RUNS INTO THE FORECAST FOR 2 TO 3 INCHES OF SNOW ACROSS
THE NORTH.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 334 PM CDT MON MAR 10 2014
PRIMARY FOCUS IN THE SHORT TERM PERIODS IS TWO FOLD...FIRST BEING
PRECIPITATION ASSOCIATED WITH A TROUGH AND ATTENDANT COLD FRONT.
THE SECOND IS GUSTY NORTHERLY WINDS ALONG AND BEHIND THE PASSING
FRONT. MILD LOWS ARE ANTICIPATED ONCE AGAIN TONIGHT AS DEEPENING
LOW PRESSURE ATOP THE WESTERN HIGH PLAINS CONTINUES TO ADVECT H85
TEMPS OF GREATER THAN 15C ACROSS THE REGION AND EFFECTIVELY MIX THE
LOWER TROPOSPHERE. LOWS TONIGHT WILL REMAIN ABOVE 0C FOR MOST
LOCATIONS. FRONT BARRELS THROUGH THE CENTRAL PLAINS EARLY ON
TUESDAY...WITH THE LEADING EDGE SOUTHEAST OF THE FORECAST AREA BY
15Z AT THE LATEST. LATEST GUIDANCE CONTINUES TO INDICATE A SHORT
PERIOD OF FAVORABLE MID-LEVEL FRONTOGENESIS WHEN SATURATION IS
PRESENT IN THE DGZ. ALSO SHOWN IS A PERIOD OF CONVECTIVE
ENHANCEMENT. RAIN CHANGING OVER TO SNOW IS LIKELY OVER MUCH OF THE
FORECAST AREA AS THE MIDLEVEL FORCING SLIDES NORTHWEST TO SOUTHEAST
THROUGH THE DAY. THE BAND IS SHOWN TO FALL APART ACROSS CENTRAL AND
SOUTHEASTERN PORTIONS OF THE CWA THOUGH. FRONTOLYSIS IS SHOWN TO
OCCUR AS THE TROUGH BECOMES LESS DEFINED AND UPPER JET DYNAMICS
WEAKEN. ALSO PROBLEMATIC TO THE FORECAST IS THE EXPECTED TIMING OF
THE CHANGE OVER TO SNOW. THE BRUNT OF THE COLD AIR SIGNIFICANTLY
LAGS THE FRONT...AND WITH THE RECENT WARM SPELL...SNOW THAT DOES
FALL MAY STRUGGLE TO ACCUMULATE. ATTM...THE FORECAST FAVORS UP TO
AN INCH OF SNOW ACROSS OUR NORTHERN ZONES ON GRASSY SURFACES...BUT
ACROSS MUCH THE CENTRAL CWA AND POINTS SOUTH...A MIX OF RAIN AND
SNOW IS LIKELY...WITH LITTLE TO NO ACCUMULATION. CAA AND DRYING
RAPIDLY TAKE HOLD LATE AFTERNOON...PRECIPITATION WILL FOLLOW
SUIT...ENDING FROM NORTHWEST TO SOUTHEAST. POSSIBLY OF GREATER
CONCERN IS THE PROJECTED WIND ASSOCIATED WITH THIS SYSTEM.
ATTM...NUMERICAL GUIDANCE IS AT OR CLOSE TO WIND ADVISORY CRITERIA
FOR KBBW...KLBF...AND KIML. DEBATED SERIOUSLY WHETHER OR NOT TO
ISSUE A WIND ADVISORY FOR THE SOUTHERN...SOUTHWEST AND FAR
SOUTHEASTERN ZONES TO ACCOUNT FOR THE FROPA AND THE APPROACH OF A PV
MAX...BUT FOR NOW WILL HOLD OFF AND WAIT FOR THE LATEST GUIDANCE
THIS EVENING AS CONFIDENCE WAS NOT YET 100 PERCENT DO TO THE MORNING
TIMING OF THE FRONT.
THE PRESENCE OF CLOUDS AND COLD AIR ADVECTION THROUGH THE DAY
TUESDAY WILL KEEP TEMPERATURES BELOW NORMAL...WITH AN ATYPICAL
DIURNAL CURVE. HIGHS ACROSS OUR SOUTHERN ZONES WILL BE REACHED
EARLY IN THE DAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 343 PM CDT MON MAR 10 2014
AS THE COLD AIRMASS PUSHES INTO THE GULF OF MEXICO THURSDAY...RETURN
FLOW FROM THE TEXAS GULF COAST WILL BRING MOISTURE INTO SOUTHERN AND
EASTERN NEBRASKA. AT THE SAME TIME...FLOW FROM THE PACIFIC NORTHWEST
ACROSS THE ROCKIES WILL BRING DECENT MID LEVEL MOISTURE INTO
NORTHERN AND WESTERN NEBRASKA. AS A RESULT OF THIS...THERE WILL BE
PRETTY DECENT MOISTURE ACROSS THE CENTRAL AND NORTHERN PLAINS WITH
PRECIPITABLE WATER VALUES OF 0.35-0.45 INCH...THOUGH IT IS
CONCENTRATED IN THE MID-TROPOSPHERIC LAYERS. A SURFACE FRONT THEN
PUNCHES THROUGH NEBRASKA AND STALLS ACROSS KANSAS. THE FRONT THEN
LIFTS BACK TO THE NORTHEAST INTO NORTH CENTRAL AND NORTHEAST
NEBRASKA. THE STRONGEST UPWARD MOTION IS EXPECTED TO BE IN NORTHERN
AND EASTERN NEBRASKA OVER THE STATIONARY FRONT.
TEMPERATURES WILL BE VERY WARM IN CENTRAL AND WESTERN NEBRASKA AND
MUCH WARMER THAN THEY WILL BE IN NORTHEAST NEBRASKA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1220 AM CDT TUE MAR 11 2014
A BANDED AREA OF IFR/LIFR IN SNOW IS EXPECTED TO DEVELOP ACROSS
THE NORTH TOWARD 12Z TUESDAY. THIS BAND OF IFR/LIFR IS EXPECTED
MOVE SOUTH THROUGH THE FCST AREA DURING THE LATE MORNING AND
AFTERNOON WITH FLIGHT CONDITIONS IMPROVING IN THE NORTH DURING THE
AFTN.
SCATTERED MVFR IS POSSIBLE TUESDAY EVENING AS A WEAK DISTURBANCE
MOVES ACROSS THE FCST AREA. ISOLATED FLURRIES MAY ACCOMPANY THE
DISTURBANCE AND PRODUCE MVFR CIGS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 10 AM CDT /9 AM MDT/ THIS MORNING TO 8 PM CDT
/7 PM MDT/ THIS EVENING FOR NEZ025>029-036>038-057>059-069>071.
&&
$$
UPDATE...CDC
SHORT TERM...JACOBS
LONG TERM...SPRINGER
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
729 PM EDT WED MAR 12 2014
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE AREA TONIGHT. MUCH COLDER
TEMPERATURES ARE EXPECTED THURSDAY AND FRIDAY AS CANADIAN HIGH
PRESSURE BUILDS ACROSS THE AREA. A GRADUAL WARMING TREND WILL OCCUR
OVER THE WEEKEND. A LOW PRESSURE SYSTEM MAY BRING UNSETTLED WEATHER
BY EARLY NEXT WEEK. HIGH PRESSURE BUILDS INTO THE AREA TUESDAY
THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 730 PM WEDNESDAY...A WELL DEFINED COLD FRONT IS SLAMMING
EASTWARD ACROSS THE TWO CAROLINAS THIS EVENING. DEEP CONVECTION
INCLUDING SEVERE THUNDERSTORMS IS CONFINED TO CENTRAL AND NORTHERN
NORTH CAROLINA AND POINTS NORTH WHERE MESOANALYSIS FIELDS INDICATE A
STRONGER DEGREE OF SURFACE CONVERGENCE ONGOING. ACTUAL SURFACE (OR
ELEVATED) INSTABILITY IS MINIMAL (LESS THAN 500 J/KG) ANYWHERE...BUT
UPPER LEVEL DYNAMICS INCREASE THE FARTHER NORTH YOU TRAVEL MAKING
CONVECTION MORE LIKELY AND MORE SIGNIFICANT.
FOR OUR PORTION OF THE CAROLINAS THE SIGNIFICANT CONVECTION SHOULD
REMAIN NORTH OF HERE. A TRAILING LINE OF SHALLOW CONVECTIVE SHOWERS
WILL SHOOT OVERHEAD...REACHING FLORENCE AND THE INTERSTATE 95
CORRIDOR AROUND 00Z/8 PM EDT...AND THE COAST ONLY 2-3 HOURS LATER.
RADAR COMPOSITES SHOW WIDE BREAKS IN THE LINE CURRENTLY ALTHOUGH THE
20Z RUC IN PARTICULAR SHOWED A MORE SOLID LINE DEVELOPING TOWARD THE
COAST IN A FEW HOURS. FORECAST POPS RANGE FROM 20-40 PERCENT.
SOUTHWEST SURFACE WINDS AHEAD OF THE LINE 15-25 MPH WILL SHIFT TO
THE NORTHWEST AS THE FRONT CROSSES. FORECAST SOUNDINGS FROM
VIRTUALLY ANY MODEL SHOW STRONG COLD ADVECTION DEVELOPING IN THE
01-03Z TIME FRAME WITH LOW-LEVEL THERMAL PROFILES BECOMING DRY
ADIABATIC DESPITE THE TIME OF DAY. WINDS JUST 1000 FEET UP SHOULD
INCREASE TO 35 KNOTS WITH 40 KNOT WINDS LURKING JUST ABOVE 2000
FEET. THESE WINDS ARE TECHNICALLY WITHIN THE SURFACE-BASED MIXED
LAYER AND ARE THEREFORE FAIR GAME TO MIX DOWN IN GUSTS. THIS IS THE
CONTINUING JUSTIFICATION FOR THE WIND ADVISORY.
SKIES WILL BECOME CLEAR OVERNIGHT WITH COLD ADVECTION DROPPING 850
MB TEMPS DOWN TO -8C TO -9C BY SUNRISE. STEEP LOW-LEVEL THERMAL
PROFILES WILL CONTINUE OVERNIGHT DUE TO THE COLD ADVECTION AND
STRONG WINDS...AND LOWS SHOULD "ONLY" FALL INTO THE MID TO UPPER 30S
DESPITE THE BITTERLY COLD CONDITIONS ALOFT.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 230 PM WEDNESDAY...BIG CHANGES AT THE ONSET OF THE SHORT TERM
PERIOD IN THE WAKE OF THE PASSAGE OF A STRONG COLD FRONT.
TEMPERATURES WILL ONCE AGAIN DROP BELOW CLIMATOLOGY. IN FACT...THU/S
HIGH TEMPS WILL RANGE SEVERAL CATEGORIES BELOW NORMAL. SLIGHTLY
WARMER TEMPS AS LOW-LEVEL THICKNESS NUDGES UPWARD AND THE AIR-MASS
MODIFIES FRIDAY. TIME-HEIGHT CROSS SECTIONS SHOW A VERY DRY COLUMN
IN PLACE WITH STRONG SUBSIDENCE THROUGH THE DAY ON THURSDAY. SOME
MOISTURE INCREASES ALOFT LATE FRIDAY BUT OVERALL SKIES WILL BE CLEAR
TO MOSTLY CLEAR THROUGH THE BULK OF THE SHORT TERM PERIOD. OTHER-
WISE...MOMENTUM TRANSFER WILL RESULT IN WINDY WEST TO NORTHWEST FLOW
THURSDAY...ESPECIALLY ACROSS THE NC ZONES. WINDS ARE EXPECTED TO
DECOUPLE THURSDAY EVENING WITH CLEAR SKIES SUPPORTING RADIATIONAL
COOLING. THUS MINS THURSDAY NIGHT WILL BE IN THE UPPER 20S WITH THE
COOL SPOTS DOWN INTO THE MID 20S. MUCH WARMER OVERNIGHT TEMPS ARE
EXPECTED BY FRIDAY NIGHT WITH WEAK SOUTHERLY FLOW AND INCREASING
HIGH CLOUDS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 230 PM WEDNESDAY...A WEAK SURFACE PRESSURE PATTERN ON SATURDAY
WITH HIGH PRESSURE WELL OFF THE COAST PAIRED WITH ZONAL MID LEVEL
FLOW ON SATURDAY. EXPECT SEASONABLE TEMPS BUT ALSO PERHAPS
INCREASING CLOUD COVER IN THE LOW LEVEL WAA. UPPER PATTERN BECOMES
QUITE COMPLEX BY SUNDAY WITH THREE JET STREAM BRANCHES. ONE WILL BE
AROUND POLAR VORTEX OVER HUDSON BAY...THE SECOND AROUND A CUTOFF
OVER MEXICO...AND THE THIRD DIVING ACROSS THE PLAINS AND OHIO
VALLEY. THE MEDIAN JET STREAM WILL BE THE MOST INSTRUMENTAL LOCALLY
AS IT GENERATES LOW PRESSURE ALONG A COLD FRONT SUNDAY NIGHT INTO
MONDAY. THERE DOES APPEAR TO BE AN APPRECIABLE INFLUX OF ATLANTIC
AND GOMEX MOISTURE PRECEDING THIS SETUP LEADING TO SOME FAIRLY GOOD
RAINFALL CHANCES AND PERHAPS AMOUNTS. ONE THING THAT DOES LOOK
DIFFERENT IN THE EXTENDED IS THE CLEANLINESS OF THE FROPA. THE
BOUNDARY WAS PREVIOUSLY PROGGED TO LINGER AND KEEP THE WEATHER
UNSETTLED WHEREAS NOW IT MAY BLOW THROUGH AND ALLOW GOOD DRYING BY
TUESDAY AFTER BRINGING A MONDAY AND MONDAY NIGHT THAT WILL BE COLDER
THAN PREVIOUSLY PORTRAYED.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 00Z...EXPECT VFR TO PREVAIL THROUGH THE VALID TAF
PERIOD...THOUGH CANNOT ENTIRELY RULE OUT A BRIEF PERIOD THIS
EVENING OF MVFR DUE TO LOW VISIBILITIES IN HEAVY RAINFALL.
VFR PREVAILS ACROSS THE AREA THIS EVENING WITH MID TO HIGH CLOUDS
AND SOUTHWEST WINDS AOB 15 KTS WITH GUSTS NEAR 25 KTS. AN
APPROACHING COLD FRONT CONTINUES TO PUSH TOWARDS THE AREA...WITH A
LINE OF SHRA/TSRA AND GUSTY WINDS JUST AHEAD OF IT. EXPECT ONLY
SHOWERS TO AFFECT OUR TERMINALS WHILE TSRA REMAIN NORTH OF OUR AREA.
WITH THE LINE MOVING THROUGH...COULD SEE GUSTS UP TO 40 KTS. BEHIND
THE FRONT...FEW/SCT CLOUDS WILL LINGER BEFORE SKIES BECOME CLEAR BY
THE LATE OVERNIGHT HOURS. STRONG WEST-NORTHWEST WINDS WILL
INFILTRATE IN BEHIND THE FRONT AS STRONG COLD AIR ADVECTION TAKES
PLACE. ON THURSDAY...VFR PREVAILS WITH NEARLY CLEAR SKIES AND
PERSISTENT GUSTY NORTHWEST WINDS...WITH GUSTS SUBSIDING TOWARDS THE
END OF THE VALID PERIOD.
EXTENDED OUTLOOK...VFR EXPECTED FRIDAY. CHANCE OF SHOWERS ON
SATURDAY. UNSETTLE WEATHER SUNDAY INTO MONDAY WITH INTERMITTENT RAIN
AND POSSIBLE MVFR/IFR CONDITIONS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 730 PM WEDNESDAY...A POWERFUL COLD FRONT WILL MOVE OFFSHORE
BETWEEN 9 PM AND MIDNIGHT...ACCOMPANIED BY A BROKEN LINE OF SHOWERS.
SOUTHWEST WINDS 15-25 KNOTS AHEAD OF THE FRONT WILL VEER TO THE
NORTHWEST AND INCREASE TO 20-30 KNOTS WITH GALE-FORCE GUSTS EXPECTED
TO DEVELOP FOR AT LEAST SEVERAL HOURS LATE THIS EVENING INTO THE
EARLY MORNING HOURS THURSDAY. SEAS CURRENTLY MEASURED AT 8 FEET AT
THE FRYING PAN SHOALS BUOY AND 6 FEET AT THE CAPE FEAR HARBOR BUOY
WILL PROBABLY INCREASE BY ANOTHER 1-3 FEET BY MIDNIGHT...BUT SHOULD
BEGIN TO SUBSIDE LATE TONIGHT AS FETCH LENGTHS SHORTEN WITH THE
INCREASINGLY OFFSHORE WIND DIRECTION.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 PM WEDNESDAY...STRONG OFFSHORE FLOW THURSDAY MORNING WILL
GRADUALLY DIMINISH ACROSS THE COASTAL WATERS THURSDAY NIGHT AS THE
FLOW VEERS FROM THE WNW TO A NNE DIRECTION. LIGHT/VARIABLE FLOW WITH
SURFACE RIDGE IN THE VICINITY FRIDAY MORNING WILL BECOME SOUTHERLY
BY FRIDAY AFTERNOON AS THE RIDGE AXIS SHIFTS OFFSHORE. SW WINDS WILL
INCREASE TO 10-15 KT (CLOSER TO 15 KT CAPE FEAR) FRIDAY NIGHT. A
LARGE RANGE OF SEAS WILL EXIST THURSDAY WITH A STRONG OFFSHORE
TRAJECTORY. SEAS WILL BE HIGHEST OFF CAPE FEAR WHERE THE FETCH IS A
LITTLE LONGER. SEAS WILL QUICKLY SUBSIDE LATE THURSDAY NIGHT INTO
FRIDAY MORNING AS THE AFOREMENTIONED RIDGE TAKES CONTROL. A NICE
BOATING DAY FRIDAY WITH ATYPICAL OCEAN CONDITIONS FOR MARCH UNDER
RIDGE OF HIGH PRESSURE.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 230 PM WEDNESDAY...SOUTHWESTERLY RETURN FLOW MORE TYPICAL OF
THE WARM SEASON ON SATURDAY AS HIGH PRESSURE SITS WELL OFF THE
COAST. CHANGES EXPECTED HOWEVER AS COLD FRONT APPROACHING FROM THE
NW AND A COMPLEX FLOW PATTERN ALOFT EVOLVES. SURFACE LOW APPROACHES
FROM THE WEST AS IT CUTS ACROSS THE GULF STATES ON SUNDAY...POSSIBLY
HANGING UP THE FRONT THIS FAR EAST RIGHT OVER THE REGION LEADING TO
SOME UNCERTAINTY AS TO HOW SUNDAYS WINDS WILL PAN OUT. FROPA IS
SLATED FOR SUNDAY NIGHT LEADING TO A MODERATE NORTHERLY WIND ON
MONDAY AS THE HIGH BUILDS IN. NO ADVISORIES EXPECTED THROUGH THE
PERIOD. THE BEST CHANCE FOR SOME 5 FT SEAS LOOKS LIKE MONDAY BUT THE
OFFSHORE FLOW WILL KEEP THEM RELATIVELY CONFINED TO OUTER WATERS
WHILE WAVE SHADOWING LEADING TO SMALLER SEAS NEAR SHORE PRECLUDES
SCEC HEADLINES.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...WIND ADVISORY UNTIL 6 AM EDT THURSDAY FOR SCZ017-023-024-032-
033-039-053>056.
NC...WIND ADVISORY UNTIL 6 AM EDT THURSDAY FOR NCZ087-096-099-
105>110.
FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
AFTERNOON FOR NCZ087-096-099-105>110.
MARINE...GALE WARNING UNTIL 6 PM EDT THURSDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...SRP
LONG TERM...MBB
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
659 PM EDT WED MAR 12 2014
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE AREA TONIGHT. MUCH COLDER
TEMPERATURES ARE EXPECTED THURSDAY AND FRIDAY AS CANADIAN HIGH
PRESSURE BUILDS ACROSS THE AREA. A GRADUAL WARMING TREND WILL OCCUR
OVER THE WEEKEND. A LOW PRESSURE SYSTEM MAY BRING UNSETTLED WEATHER
BY EARLY NEXT WEEK. HIGH PRESSURE BUILDS INTO THE AREA TUESDAY
THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 730 PM WEDNESDAY...A WELL DEFINED COLD FRONT IS SLAMMING
EASTWARD ACROSS THE TWO CAROLINAS THIS EVENING. DEEP CONVECTION
INCLUDING SEVERE THUNDERSTORMS IS CONFINED TO CENTRAL AND NORTHERN
NORTH CAROLINA AND POINTS NORTH WHERE MESOANALYSIS FIELDS INDICATE A
STRONGER DEGREE OF SURFACE CONVERGENCE ONGOING. ACTUAL SURFACE (OR
ELEVATED) INSTABILITY IS MINIMAL (LESS THAN 500 J/KG) ANYWHERE...BUT
UPPER LEVEL DYNAMICS INCREASE THE FARTHER NORTH YOU TRAVEL MAKING
CONVECTION MORE LIKELY AND MORE SIGNIFICANT.
FOR OUR PORTION OF THE CAROLINAS THE SIGNIFICANT CONVECTION SHOULD
REMAIN NORTH OF HERE. A TRAILING LINE OF SHALLOW CONVECTIVE SHOWERS
WILL SHOOT OVERHEAD...REACHING FLORENCE AND THE INTERSTATE 95
CORRIDOR AROUND 00Z/8 PM EDT...AND THE COAST ONLY 2-3 HOURS LATER.
RADAR COMPOSITES SHOW WIDE BREAKS IN THE LINE CURRENTLY ALTHOUGH THE
20Z RUC IN PARTICULAR SHOWED A MORE SOLID LINE DEVELOPING TOWARD THE
COAST IN A FEW HOURS. FORECAST POPS RANGE FROM 20-40 PERCENT.
SOUTHWEST SURFACE WINDS AHEAD OF THE LINE 15-25 MPH WILL SHIFT TO
THE NORTHWEST AS THE FRONT CROSSES. FORECAST SOUNDINGS FROM
VIRTUALLY ANY MODEL SHOW STRONG COLD ADVECTION DEVELOPING IN THE
01-03Z TIME FRAME WITH LOW-LEVEL THERMAL PROFILES BECOMING DRY
ADIABATIC DESPITE THE TIME OF DAY. WINDS JUST 1000 FEET UP SHOULD
INCREASE TO 35 KNOTS WITH 40 KNOT WINDS LURKING JUST ABOVE 2000
FEET. THESE WINDS ARE TECHNICALLY WITHIN THE SURFACE-BASED MIXED
LAYER AND ARE THEREFORE FAIR GAME TO MIX DOWN IN GUSTS. THIS IS THE
CONTINUING JUSTIFICATION FOR THE WIND ADVISORY.
SKIES WILL BECOME CLEAR OVERNIGHT WITH COLD ADVECTION DROPPING 850
MB TEMPS DOWN TO -8C TO -9C BY SUNRISE. STEEP LOW-LEVEL THERMAL
PROFILES WILL CONTINUE OVERNIGHT DUE TO THE COLD ADVECTION AND
STRONG WINDS...AND LOWS SHOULD "ONLY" FALL INTO THE MID TO UPPER 30S
DESPITE THE BITTERLY COLD CONDITIONS ALOFT.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 PM WEDNESDAY...BIG CHANGES AT THE ONSET OF THE SHORT TERM
PERIOD IN THE WAKE OF THE PASSAGE OF A STRONG COLD FRONT.
TEMPERATURES WILL ONCE AGAIN DROP BELOW CLIMATOLOGY. IN FACT...THU/S
HIGH TEMPS WILL RANGE SEVERAL CATEGORIES BELOW NORMAL. SLIGHTLY
WARMER TEMPS AS LOW-LEVEL THICKNESS NUDGES UPWARD AND THE AIR-MASS
MODIFIES FRIDAY. TIME-HEIGHT CROSS SECTIONS SHOW A VERY DRY COLUMN
IN PLACE WITH STRONG SUBSIDENCE THROUGH THE DAY ON THURSDAY. SOME
MOISTURE INCREASES ALOFT LATE FRIDAY BUT OVERALL SKIES WILL BE CLEAR
TO MOSTLY CLEAR THROUGH THE BULK OF THE SHORT TERM PERIOD. OTHER-
WISE...MOMENTUM TRANSFER WILL RESULT IN WINDY WEST TO NORTHWEST FLOW
THURSDAY...ESPECIALLY ACROSS THE NC ZONES. WINDS ARE EXPECTED TO
DECOUPLE THURSDAY EVENING WITH CLEAR SKIES SUPPORTING RADIATIONAL
COOLING. THUS MINS THURSDAY NIGHT WILL BE IN THE UPPER 20S WITH THE
COOL SPOTS DOWN INTO THE MID 20S. MUCH WARMER OVERNIGHT TEMPS ARE
EXPECTED BY FRIDAY NIGHT WITH WEAK SOUTHERLY FLOW AND INCREASING
HIGH CLOUDS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 230 PM WEDNESDAY...A WEAK SURFACE PRESSURE PATTERN ON SATURDAY
WITH HIGH PRESSURE WELL OFF THE COAST PAIRED WITH ZONAL MID LEVEL
FLOW ON SATURDAY. EXPECT SEASONABLE TEMPS BUT ALSO PERHAPS
INCREASING CLOUD COVER IN THE LOW LEVEL WAA. UPPER PATTERN BECOMES
QUITE COMPLEX BY SUNDAY WITH THREE JET STREAM BRANCHES. ONE WILL BE
AROUND POLAR VORTEX OVER HUDSON BAY...THE SECOND AROUND A CUTOFF
OVER MEXICO...AND THE THIRD DIVING ACROSS THE PLAINS AND OHIO
VALLEY. THE MEDIAN JET STREAM WILL BE THE MOST INSTRUMENTAL LOCALLY
AS IT GENERATES LOW PRESSURE ALONG A COLD FRONT SUNDAY NIGHT INTO
MONDAY. THERE DOES APPEAR TO BE AN APPRECIABLE INFLUX OF ATLANTIC
AND GOMEX MOISTURE PRECEDING THIS SETUP LEADING TO SOME FAIRLY GOOD
RAINFALL CHANCES AND PERHAPS AMOUNTS. ONE THING THAT DOES LOOK
DIFFERENT IN THE EXTENDED IS THE CLEANLINESS OF THE FROPA. THE
BOUNDARY WAS PREVIOUSLY PROGGED TO LINGER AND KEEP THE WEATHER
UNSETTLED WHEREAS NOW IT MAY BLOW THROUGH AND ALLOW GOOD DRYING BY
TUESDAY AFTER BRINGING A MONDAY AND MONDAY NIGHT THAT WILL BE COLDER
THAN PREVIOUSLY PORTRAYED.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...ISOLATED PATCHES OF SHOWERS ARE POSSIBLE THIS
AFTERNOON...HOWEVER COVERAGE ONLY WARRANTS A VCSH MENTION. SOUTHWEST
WINDS WILL INCREASE THROUGH THE AFTERNOON HOURS AS LOW PRESSURE AND
A STRONG COLD FRONT APPROACH THE REGION. THE NAM IS HINTING AT A
SMALL BAND OF SHOWERS ALONG THE FRONT THIS EVENING...AND HAVE ADDED
A TEMPO GROUP FOR SHOWERS ALONG THE COAST. POST FRONTAL...LOOK FOR
STRONG WEST NORTHWEST WINDS WITH THE STRONG COLD AIR ADVECTION. VFR
CONDITIONS WILL PREVAIL THROUGH THE OVERNIGHT HOURS INTO THURSDAY
WITH A CONTINUED GUSTY NORTHWEST WIND.
EXTENDED OUTLOOK...VFR EXPECTED THURSDAY AND FRIDAY. CHANCE OF
SHOWERS ON SATURDAY. UNSETTLE WEATHER SUNDAY INTO MONDAY WITH
INTERMITTENT RAIN AND POSSIBLE MVFR/IFR CONDITIONS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 730 PM WEDNESDAY...A POWERFUL COLD FRONT WILL MOVE OFFSHORE
BETWEEN 9 PM AND MIDNIGHT...ACCOMPANIED BY A BROKEN LINE OF SHOWERS.
SOUTHWEST WINDS 15-25 KNOTS AHEAD OF THE FRONT WILL VEER TO THE
NORTHWEST AND INCREASE TO 20-30 KNOTS WITH GALE-FORCE GUSTS EXPECTED
TO DEVELOP FOR AT LEAST SEVERAL HOURS LATE THIS EVENING INTO THE
EARLY MORNING HOURS THURSDAY. SEAS CURRENTLY MEASURED AT 8 FEET AT
THE FRYING PAN SHOALS BUOY AND 6 FEET AT THE CAPE FEAR HARBOR BUOY
WILL PROBABLY INCREASE BY ANOTHER 1-3 FEET BY MIDNIGHT...BUT SHOULD
BEGIN TO SUBSIDE LATE TONIGHT AS FETCH LENGTHS SHORTEN WITH THE
INCREASINGLY OFFSHORE WIND DIRECTION.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 PM WEDNESDAY...STRONG OFFSHORE FLOW THURSDAY MORNING WILL
GRADUALLY DIMINISH ACROSS THE COASTAL WATERS THURSDAY NIGHT AS THE
FLOW VEERS FROM THE WNW TO A NNE DIRECTION. LIGHT/VARIABLE FLOW WITH
SURFACE RIDGE IN THE VICINITY FRIDAY MORNING WILL BECOME SOUTHERLY
BY FRIDAY AFTERNOON AS THE RIDGE AXIS SHIFTS OFFSHORE. SW WINDS WILL
INCREASE TO 10-15 KT (CLOSER TO 15 KT CAPE FEAR) FRIDAY NIGHT. A
LARGE RANGE OF SEAS WILL EXIST THURSDAY WITH A STRONG OFFSHORE
TRAJECTORY. SEAS WILL BE HIGHEST OFF CAPE FEAR WHERE THE FETCH IS A
LITTLE LONGER. SEAS WILL QUICKLY SUBSIDE LATE THURSDAY NIGHT INTO
FRIDAY MORNING AS THE AFOREMENTIONED RIDGE TAKES CONTROL. A NICE
BOATING DAY FRIDAY WITH ATYPICAL OCEAN CONDITIONS FOR MARCH UNDER
RIDGE OF HIGH PRESSURE.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 230 PM WEDNESDAY...SOUTHWESTERLY RETURN FLOW MORE TYPICAL OF
THE WARM SEASON ON SATURDAY AS HIGH PRESSURE SITS WELL OFF THE
COAST. CHANGES EXPECTED HOWEVER AS COLD FRONT APPROACHING FROM THE
NW AND A COMPLEX FLOW PATTERN ALOFT EVOLVES. SURFACE LOW APPROACHES
FROM THE WEST AS IT CUTS ACROSS THE GULF STATES ON SUNDAY...POSSIBLY
HANGING UP THE FRONT THIS FAR EAST RIGHT OVER THE REGION LEADING TO
SOME UNCERTAINTY AS TO HOW SUNDAYS WINDS WILL PAN OUT. FROPA IS
SLATED FOR SUNDAY NIGHT LEADING TO A MODERATE NORTHERLY WIND ON
MONDAY AS THE HIGH BUILDS IN. NO ADVISORIES EXPECTED THROUGH THE
PERIOD. THE BEST CHANCE FOR SOME 5 FT SEAS LOOKS LIKE MONDAY BUT THE
OFFSHORE FLOW WILL KEEP THEM RELATIVELY CONFINED TO OUTER WATERS
WHILE WAVE SHADOWING LEADING TO SMALLER SEAS NEAR SHORE PRECLUDES
SCEC HEADLINES.
&&
.FIRE...
AS OF 230 PM WEDNESDAY...GUSTY WINDS THURSDAY IN THE POST-FRONTAL
REGIME RESULTING FROM THE PRESSURE GRADIENT AND MOMENTUM TRANSFER
WILL BE CLOSE TO RED FLAG CRITERIA ACROSS A PORTION OF THE FORECAST
AREA (WINDS STRONGEST ACROSS THE NC ZONES). MEANWHILE...MIXING WILL
ALLOW DRIER CONDITIONS ALOFT TO FILTER TO THE SURFACE RESULTING IN
VERY LOW RELATIVE HUMIDITY DURING THE DAY. RECENT RAINFALL DID NOT
CONTRIBUTE MUCH TO FUEL MOISTURES PER NFDRS LOCATIONS...HOWEVER THE
COOL MID-MARCH TEMPERATURES EXPECTED THURSDAY ARE NOT SUPPORTIVE OF
IGNITION. PER COORDINATION...PLAN ON ISSUING A FIRE DANGER STATEMENT
FOR THE SC ZONES TO HEIGHTEN AWARENESS OF THE CONDITIONS FOR
WILDFIRES. GIVEN WINDS ARE EXPECTED TO BE A LITTLE STRONGER ACROSS
OUR NC ZONES PER COORDINATION WILL ISSUE A FIRE WEATHER WATCH
GENERALLY FROM 15-22Z THURSDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...WIND ADVISORY UNTIL 6 AM EDT THURSDAY FOR SCZ017-023-024-032-
033-039-053>056.
NC...WIND ADVISORY UNTIL 6 AM EDT THURSDAY FOR NCZ087-096-099-
105>110.
FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
AFTERNOON FOR NCZ087-096-099-105>110.
MARINE...GALE WARNING UNTIL 6 PM EDT THURSDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...SRP
LONG TERM...MBB
AVIATION...HDL/SHK
FIRE WEATHER...SRP
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1016 PM CDT WED MAR 12 2014
.UPDATE...
ISSUED AT 1016 PM CDT WED MAR 12 2014
LATEST SATELLITE LOOP SHOWS A CLEAR SKY ACROSS WESTERN AND CENTRAL
NORTH DAKOTA. THE HRRR ADVERTISES SOME POTENTIAL OF FOG IN THE
JAMES RIVER VALLEY OVERNIGHT WHERE TEMPERATURES AND DEWPOINTS ARE
ALREADY THE SAME AND RH IS 100 PERCENT. CANNOT RULE THIS OUT AND
HAVE ADDED THIS IN THE GRIDS. WARM AIR ADVECTION CONTINUES
OVERNIGHT INTO THURSDAY MORNING. NO SIGNIFICANT ADJUSTMENTS THIS
UPDATE AS THE FOREACST ELEMENTS REMAIN IN GOOD SHAPE.
UPDATE ISSUED AT 641 PM CDT WED MAR 12 2014
A LOW PRESSURE TROUGH HAS MOVED THOUGH ALL BUT THE FAR EASTERN
PORTIONS OF CENTRAL NORTH DAKOTA. WIND HAS JUST SHIFTED WESTERLY
AT JAMESTOWN. WEST TO NORTHWEST WINDS GUSTING TO AROUND 30 MPH
ACROSS THE REMAINDER OF THE FORECAST AREA. EXPECT WINDS TO
DIMINISH WITHIN THE NEXT HOUR OR TWO. OTHERWISE MAINLY CLEAR SKIES
EXPECTED TONIGHT. MADE SOME MINOR ADJUSTMENTS TO SKY COVER GRIDS
TO ACCOUNT FOR CLOUDS MOVING OUT OF THE EASTERN CWA. ALSO SLOWED
THE DIURNAL DROP IN TEMPERATURES A BIT THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 405 PM CDT WED MAR 12 2014
BENIGN WEATHER WILL CONTINUE OVERNIGHT INTO THURSDAY WITH UPPER
RIDGING TO THE WEST AND MILD WESTERLY FLOW. HYDRO ISSUES CONTINUE
TO BE THE MAIN OPERATIONAL FOCUS AND A DETAILED DISCUSSION IS
INCLUDED BELOW.
EXPECT EVEN WARMER TEMPERATURES ON THURSDAY WITH HIGHS IN THE
LOWER 40S NORTH AND MID/UPPER 50S SOUTH. THERE IS A LOW
PROBABILITY OF A FEW SPRINKLES OR FLURRIES THURSDAY MORNING ACROSS
THE FAR NORTH AND HAVE OPTED NOT TO INCLUDE IN FORECAST GRIDS AT
THIS TIME.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 405 PM CDT WED MAR 12 2014
A BRIEF COOL DOWN ON SATURDAY FOLLOWED BY A RETURN TO NEAR TO
ABOVE NORMAL TEMPERATURES WILL HIGHLIGHT THE EXTENDED FORECAST.
THE 12 UTC DETERMINISTIC AND ENSEMBLE SUITE ARE IN GOOD AGREEMENT
ON A STRONG COLD FRONT PROPAGATING ACROSS NORTH DAKOTA THROUGH THE
DAY ON FRIDAY WITH A COLD 1037 MB SURFACE HIGH BUILDING INTO THE
NORTHERN PLAINS ON SATURDAY. AS A RESULT...HIGHS ON SATURDAY WILL
RANGE FROM AROUND 20 ACROSS THE TURTLE MOUNTAINS TO THE UPPER 30S
FAR SOUTHWEST. THERE IS SOME UNCERTAINTY ON HOW FAR EAST
PRECIPITATION ASSOCIATED WITH THE LOW LEVEL BAROCLINIC ZONE ON THE
WESTERN PERIPHERY OF THE HIGH WILL BE ABLE TO DEVELOP WITH DRY
EASTERLY FLOW FROM THE HIGH. FOR NOW...FOLLOWED THE 12 UTC
GFS/ECMWF WHICH KEEP THE PRECIPITATION FURTHEST WEST. RETURN
FLOW IS EXPECTED TO COMMENCE ON SUNDAY WITH A WARMING TREND
BENEATH A BROAD UPPER LEVEL RIDGE INTO MONDAY. THE MODELS DO BEGIN
TO DIVERGE A BIT TUESDAY ONWARD IN REGARDS TO THE POTENTIAL BREAK
DOWN OF THE RIDGE MID NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 641 PM CDT WED MAR 12 2014
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. NORTHWEST WINDS 20 TO
30 MPH EARLY THIS EVENING SHOULD SUBSIDE QUICKLY. OTHERWISE MAINLY
CLEAR THROUGH THE PERIOD WITH INCREASING WINDS ONCE AGAIN THURSDAY
AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 405 PM CDT WED MAR 12 2014
MULTIPLE FLOOD HEADLINES REMAIN IN EFFECT ACROSS THE MISSOURI
BASIN AS ICE CONTINUES TO CONTRIBUTE TO PROBLEMATIC HIGH WATER ON
MANY AREA RIVERS AND STREAMS. THIS INCLUDES THE CANNONBALL
RIVER...CEDAR CREEK...HEART RIVER...LITTLE MISSOURI RIVER AND THE
MISSOURI RIVER ABOVE LAKE SAKAKAWEA. ELEVATED AND FLUCTUATING
WATER LEVELS ARE LIKELY TO CONTINUE UNTIL THE CHANNELS BECOME ICE
FREE. THE LACK OF ADDITIONAL FORECAST PRECIPITATION TO INCREASE
FLOWS AND MOVE THE ICE DOWNSTREAM SUGGESTS ICE IMPACTS COULD BE
PROLONGED INTO THE WEEKEND FOR SOME LOCATIONS. THE MISSOURI RIVER
IN THE BISMARCK/MANDAN VICINITY WILL HAVE TO BE CLOSELY MONITORED
OVER THE COMING DAYS FOR ICE JAM POTENTIAL AS SIGNIFICANT AMOUNTS
OF LOCAL ICE REMAINS IN THE CHANNEL...WITH ADDITIONAL ICE
CONTRIBUTIONS FROM THE HEART AND KNIFE RIVERS. RUNOFF IS ALSO
LIKELY TO INCREASE ACROSS THE SOURIS BASIN...HOWEVER...INITIAL
INDICATIONS ARE THAT SLIGHTLY DRIER SOILS ARE ALLOWING FOR GREATER
INFILTRATION.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM /AVIATION...RP KINNEY
LONG TERM/HYDROLOGY...AYD
AVIATION...MM
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1229 PM CDT TUE MAR 11 2014
.UPDATE...
ISSUED AT 1018 AM CDT TUE MAR 11 2014
HAVE UPDATED TO CUT EXPECTED SNOW AMOUNTS...LARGELY FOR LACK OF
COOLING BUT ALSO FOR LESS PRECIPITATION EXPECTED OVER OUR
SOUTHEAST CORNER...THAT IS NORTHWEST IOWA AWAY FROM THE NORTHERN
STATE BORDER. THE WEAKNESS OF THE COOLING IS ALLOWING ACCUMULATING
SNOW TO FALL ONLY IN THE AREAS OF HEAVIER PRECIPITATION...AND
THERE IS NOT MUCH OF THAT GOING TO BE LEFT. THE EXCEPTION IS FROM
NORTH OF BROOKINGS INTO LINCOLN COUNTY MN WHERE THERE HAVE BEEN
SOME ACCUMULATIONS ON ROADS...BUT EVEN THERE THE PRECIPITATION
WILL MOVE OUT SOON. A REPORT FROM MARSHALL MINNESOTA INDICATED
0.37 INCH OF PRECIPITATION AND NO SNOW. HAVE ALSO CUT
PRECIPITATION MENTION OUT FOR THIS EVENING FAR SOUTHEAST.
TEMPERATURES WILL DO NOTHING EXCITING WITH THE CLOUD COVER AND
STIFF NORTHERLY BREEZE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 424 AM CDT TUE MAR 11 2014
COMPLEX FORECAST TODAY AS A BAND OF PRECIPITATION MOVES SOUTHEAST
ACROSS THE CWA. AS OF 4 AM THIS BAND IS ALONG AND NORTH OF HIGHWAY
14. THIS MATCHES WELL WITH A STRONG AREA OF MID LEVEL FRONTOGENESIS.
DECENT INSTABILITY ABOVE THE FRONT...THUS NOT SURPRISED BY THE HIGH
REFLECTIVITY CURRENTLY ON RADAR. BOUNDARY LAYER REMAINS QUITE
WARM...AND THUS PRECIPITATION TYPE IS CURRENTLY RAIN. THIS FIRST
AREA OF FRONTOGENESIS SHIFTS SOUTH THIS MORNING...BUT ALSO BEGINS TO
WEAKEN. THIS OCCURS AS THE MAIN WAVE EJECTS OUT OF THE
ROCKIES...WITH THE BEST QG FORCING SOUTH OF THE MISSOURI RIVER. THUS
MAKES SENSE THAT WE SEE FRONTOGENESIS INTENSIFY AGAIN SOUTH OF
INTERSTATE 90 AS MODELS SHOW. SO EXPECT WE SEE THE MODERATE TO HEAVY
BAND ALONG HIGHWAY 14 SLOWLY WEAKEN THIS MORNING AS IT MOVES
SOUTH...THEN INTENSIFY AGAIN THIS AFTERNOON SOUTH OF INTERSTATE 90
AS THE FRONT STRENGTHENS AND INTERACTS WITH THE UPPER WAVE. PRETTY
LARGE UNCERTAINTY ON HOW MUCH THE BAND WEAKENS THIS MORNING...AND
HOW QUICKLY IT INTENSIFIES THIS AFTERNOON. THIS IS IMPORTANT NOT
ONLY FOR QPF...BUT ALSO PRECIPITATION TYPE.
IF PRECIPITATION STAYS ON THE LIGHTER SIDE...IT WILL LIKELY STAY
MAINLY RAIN. ONLY EXPECTING A CHANGEOVER TO SNOW DUE TO DYNAMIC
COOLING IN THE HEAVIEST PRECIPITATION. SO IF THIS HEAVIER BAND
WEAKENS ENOUGH...OUR SNOW FORECAST COULD BE IN TROUBLE. THE LATEST
06Z NAM AND HRRR AND RAP DO SHOW THIS MORE PRONOUNCED WEAKENING...SO
WILL HAVE TO KEEP AN EYE ON THIS. EVEN AS THE BAND INTENSIFIES SOUTH
OF INTERSTATE 90 THIS AFTERNOON...BOUNDARY LAYER COULD BE WARM
ENOUGH TO KEEP THINGS RAIN...OR JUST A WET NON ACCUMULATING SNOW. SO
FOR NOW...WILL KEEP 1 TO 2 INCHES IN THE FORECAST FOR MOST OF THE
CWA...BUT WILL NEED TO MONITOR TEMPERATURE TRENDS THROUGH THE DAY.
FOLLOWED CLOSE TO THE ARW AND NAM FOR TIMING...WITH THE BAND
IMPACTING INTERSTATE 90 MID TO LATE MORNING...AND NORTHWEST IOWA
LATE MORNING INTO THE AFTERNOON. SKIES WILL STAY MOSTLY CLOUDY
TONIGHT...AND AS A SECONDARY WAVE DROP SOUTH...COULD SEE SOME
SCATTERED SNOW SHOWERS DEVELOP AFTER MIDNIGHT. BASED ON LATEST MODEL
RUNS DID SHIFT THIS SNOW SHOWER AREA FURTHER WEST FROM THE PREVIOUS
FORECAST...CENTERED MORE BETWEEN THE JAMES RIVER AND INTERSTATE 29
CORRIDOR.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 424 AM CDT TUE MAR 11 2014
FOR THE MEDIUM RANGE...HAVE SIDED CLOSER TO A BLEND OF THE
CANADIAN/GFS AND ECMWF. OPTED TO EXCLUDE THE NAM AS IT SEEMED TO BE
THE OUTLIER IN TERMS OF THE PROGRESSION OF SYSTEMS AND SEEMED TO BE
SLOWER THAN THE OTHER SOLUTIONS. MODELS SUGGEST BAND OF LIGHT SNOW
SHOWERS EARLY ON WEDNESDAY THOUGH SATURATION IN THE DENDRITIC LAYER
APPEARS TO BE A SIGNIFICANT ISSUE. MODEL SOUNDINGS VARY FROM
SOLUTION TO SOLUTION...BUT IN GENERAL...ALL HINT AT ONLY A LIMITED
AMOUNT OF THE DENDRITIC LAYER SATURATING AND WITH THE WARMER AIR
BEGINNING TO RETURN IT APPEARS AS THOUGH THE CHANCE OF DEVELOPING
THROUGHOUT THE MORNING DECREASES WITH TIME. HAVE KEPT LOW CHANCE
POPS THROUGH THE EARLY MORNING HOURS...BUT DROPPED TO FLURRIES IN
THE LATE MORNING IF ANYTHING IS LEFT BY THEN. EXPECT NICE WARMING
WEDNESDAY INTO THURSDAY...HOWEVER STRATUS MAY LINGER AHEAD OF THE
WARM FRONT ACROSS THE EASTERN CWA ON WEDNESDAY LIMITING WARMING
POTENTIAL. WARMED HIGHS ON THURSDAY WITH CLEAR SKIES AND NICE
SOUTHWEST FLOW ALOFT RESULTING IN 925 HPA TEMPS WARMING INTO THE
10-13C RANGE.
COLD FRONT MOVES THROUGH THE AREA ON THURSDAY NIGHT. SHORT WAVE
MOVES THROUGH MINNESOTA LATE THURSDAY NIGHT INTO FRIDAY. FOR THE
MOST PART...IT APPEARS AS THOUGH THE WAVE IS FOCUSED EAST OF THE
FORECAST AREA...SO LEFT FORECAST DRY FOR THE TIME BEING. BACK DOOR
COLD FRONT MOVES INTO THE UPPER MIDWEST FRIDAY NIGHT. FRONT WORKS
BACK TO THE WEST ON SATURDAY...WITH COOL NORTHEAST FLOW EAST OF THE
FRONT. A SERIES OF SHORT WAVES APPEAR TO MOVE THROUGH THE AREA ON
SATURDAY NEAR THE FRONT...POTENTIALLY CREATING SOME LIGHT RAIN/SNOW
DEPENDING WHICH SIDE OF THE FRONT A PARTICULAR LOCATION IS ON. THE
FRONT BEGINS TO SHIFT EAST ACROSS THE REGION ON SUNDAY LEADING TO A
WARMING TREND. STRONG SOUTHERLY FLOW DEVELOPS ON MONDAY...LEADING A
WARM BUT WINDY DAY. INCREASED WINDS ON MONDAY COMPARED TO THE
GUIDANCE BUT MAY NOT HAVE INCREASED ENOUGH WITH 20-30 KNOTS OF FLOW
THROUGH THE AFTERNOON HOURS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1229 PM CDT TUE MAR 11 2014
SOUTHEAST OF MJQ/FSD/YKN LINE WIDESPREAD CEILINGS 1-3K FEET AND
AREAS OF VISIBILITIES 3-5SM IN -RASN WILL IMPROVE FROM THE
NORTHWEST BY 12/00Z TO VFR WITH A FEW AREAS OF CEILINGS 1-3K FEET.
OVER THE NORTHERN AND WESTERN PARTS OF THE FORECAST
AREA...GENERALLY VFR...BUT A FEW AREAS OF CEILINGS 1-3K FEET
MAINLY BEFORE 12/00Z AND AFTER 12/06Z.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...
SHORT TERM...CHENARD
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1018 AM CDT TUE MAR 11 2014
.UPDATE...
ISSUED AT 1018 AM CDT TUE MAR 11 2014
HAVE UPDATED TO CUT EXPECTED SNOW AMOUNTS...LARGELY FOR LACK OF
COOLING BUT ALSO FOR LESS PRECIPITATION EXPECTED OVER OUR
SOUTHEAST CORNER...THAT IS NORTHWEST IOWA AWAY FROM THE NORTHERN
STATE BORDER. THE WEAKNESS OF THE COOLING IS ALLOWING ACCUMULATING
SNOW TO FALL ONLY IN THE AREAS OF HEAVIER PRECIPITATION...AND
THERE IS NOT MUCH OF THAT GOING TO BE LEFT. THE EXCEPTION IS FROM
NORTH OF BROOKINGS INTO LINCOLN COUNTY MN WHERE THERE HAVE BEEN
SOME ACCUMULATIONS ON ROADS...BUT EVEN THERE THE PRECIPITATION
WILL MOVE OUT SOON. A REPORT FROM MARSHALL MINNESOTA INDICATED
0.37 INCH OF PRECIPITATION AND NO SNOW. HAVE ALSO CUT
PRECIPITATION MENTION OUT FOR THIS EVENING FAR SOUTHEAST.
TEMPERATURES WILL DO NOTHING EXCITING WITH THE CLOUD COVER AND
STIFF NORTHERLY BREEZE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 424 AM CDT TUE MAR 11 2014
COMPLEX FORECAST TODAY AS A BAND OF PRECIPITATION MOVES SOUTHEAST
ACROSS THE CWA. AS OF 4 AM THIS BAND IS ALONG AND NORTH OF HIGHWAY
14. THIS MATCHES WELL WITH A STRONG AREA OF MID LEVEL FRONTOGENESIS.
DECENT INSTABILITY ABOVE THE FRONT...THUS NOT SURPRISED BY THE HIGH
REFLECTIVITY CURRENTLY ON RADAR. BOUNDARY LAYER REMAINS QUITE
WARM...AND THUS PRECIPITATION TYPE IS CURRENTLY RAIN. THIS FIRST
AREA OF FRONTOGENESIS SHIFTS SOUTH THIS MORNING...BUT ALSO BEGINS TO
WEAKEN. THIS OCCURS AS THE MAIN WAVE EJECTS OUT OF THE
ROCKIES...WITH THE BEST QG FORCING SOUTH OF THE MISSOURI RIVER. THUS
MAKES SENSE THAT WE SEE FRONTOGENESIS INTENSIFY AGAIN SOUTH OF
INTERSTATE 90 AS MODELS SHOW. SO EXPECT WE SEE THE MODERATE TO HEAVY
BAND ALONG HIGHWAY 14 SLOWLY WEAKEN THIS MORNING AS IT MOVES
SOUTH...THEN INTENSIFY AGAIN THIS AFTERNOON SOUTH OF INTERSTATE 90
AS THE FRONT STRENGTHENS AND INTERACTS WITH THE UPPER WAVE. PRETTY
LARGE UNCERTAINTY ON HOW MUCH THE BAND WEAKENS THIS MORNING...AND
HOW QUICKLY IT INTENSIFIES THIS AFTERNOON. THIS IS IMPORTANT NOT
ONLY FOR QPF...BUT ALSO PRECIPITATION TYPE.
IF PRECIPITATION STAYS ON THE LIGHTER SIDE...IT WILL LIKELY STAY
MAINLY RAIN. ONLY EXPECTING A CHANGEOVER TO SNOW DUE TO DYNAMIC
COOLING IN THE HEAVIEST PRECIPITATION. SO IF THIS HEAVIER BAND
WEAKENS ENOUGH...OUR SNOW FORECAST COULD BE IN TROUBLE. THE LATEST
06Z NAM AND HRRR AND RAP DO SHOW THIS MORE PRONOUNCED WEAKENING...SO
WILL HAVE TO KEEP AN EYE ON THIS. EVEN AS THE BAND INTENSIFIES SOUTH
OF INTERSTATE 90 THIS AFTERNOON...BOUNDARY LAYER COULD BE WARM
ENOUGH TO KEEP THINGS RAIN...OR JUST A WET NON ACCUMULATING SNOW. SO
FOR NOW...WILL KEEP 1 TO 2 INCHES IN THE FORECAST FOR MOST OF THE
CWA...BUT WILL NEED TO MONITOR TEMPERATURE TRENDS THROUGH THE DAY.
FOLLOWED CLOSE TO THE ARW AND NAM FOR TIMING...WITH THE BAND
IMPACTING INTERSTATE 90 MID TO LATE MORNING...AND NORTHWEST IOWA
LATE MORNING INTO THE AFTERNOON. SKIES WILL STAY MOSTLY CLOUDY
TONIGHT...AND AS A SECONDARY WAVE DROP SOUTH...COULD SEE SOME
SCATTERED SNOW SHOWERS DEVELOP AFTER MIDNIGHT. BASED ON LATEST MODEL
RUNS DID SHIFT THIS SNOW SHOWER AREA FURTHER WEST FROM THE PREVIOUS
FORECAST...CENTERED MORE BETWEEN THE JAMES RIVER AND INTERSTATE 29
CORRIDOR.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 424 AM CDT TUE MAR 11 2014
FOR THE MEDIUM RANGE...HAVE SIDED CLOSER TO A BLEND OF THE
CANADIAN/GFS AND ECMWF. OPTED TO EXCLUDE THE NAM AS IT SEEMED TO BE
THE OUTLIER IN TERMS OF THE PROGRESSION OF SYSTEMS AND SEEMED TO BE
SLOWER THAN THE OTHER SOLUTIONS. MODELS SUGGEST BAND OF LIGHT SNOW
SHOWERS EARLY ON WEDNESDAY THOUGH SATURATION IN THE DENDRITIC LAYER
APPEARS TO BE A SIGNIFICANT ISSUE. MODEL SOUNDINGS VARY FROM
SOLUTION TO SOLUTION...BUT IN GENERAL...ALL HINT AT ONLY A LIMITED
AMOUNT OF THE DENDRITIC LAYER SATURATING AND WITH THE WARMER AIR
BEGINNING TO RETURN IT APPEARS AS THOUGH THE CHANCE OF DEVELOPING
THROUGHOUT THE MORNING DECREASES WITH TIME. HAVE KEPT LOW CHANCE
POPS THROUGH THE EARLY MORNING HOURS...BUT DROPPED TO FLURRIES IN
THE LATE MORNING IF ANYTHING IS LEFT BY THEN. EXPECT NICE WARMING
WEDNESDAY INTO THURSDAY...HOWEVER STRATUS MAY LINGER AHEAD OF THE
WARM FRONT ACROSS THE EASTERN CWA ON WEDNESDAY LIMITING WARMING
POTENTIAL. WARMED HIGHS ON THURSDAY WITH CLEAR SKIES AND NICE
SOUTHWEST FLOW ALOFT RESULTING IN 925 HPA TEMPS WARMING INTO THE
10-13C RANGE.
COLD FRONT MOVES THROUGH THE AREA ON THURSDAY NIGHT. SHORT WAVE
MOVES THROUGH MINNESOTA LATE THURSDAY NIGHT INTO FRIDAY. FOR THE
MOST PART...IT APPEARS AS THOUGH THE WAVE IS FOCUSED EAST OF THE
FORECAST AREA...SO LEFT FORECAST DRY FOR THE TIME BEING. BACK DOOR
COLD FRONT MOVES INTO THE UPPER MIDWEST FRIDAY NIGHT. FRONT WORKS
BACK TO THE WEST ON SATURDAY...WITH COOL NORTHEAST FLOW EAST OF THE
FRONT. A SERIES OF SHORT WAVES APPEAR TO MOVE THROUGH THE AREA ON
SATURDAY NEAR THE FRONT...POTENTIALLY CREATING SOME LIGHT RAIN/SNOW
DEPENDING WHICH SIDE OF THE FRONT A PARTICULAR LOCATION IS ON. THE
FRONT BEGINS TO SHIFT EAST ACROSS THE REGION ON SUNDAY LEADING TO A
WARMING TREND. STRONG SOUTHERLY FLOW DEVELOPS ON MONDAY...LEADING A
WARM BUT WINDY DAY. INCREASED WINDS ON MONDAY COMPARED TO THE
GUIDANCE BUT MAY NOT HAVE INCREASED ENOUGH WITH 20-30 KNOTS OF FLOW
THROUGH THE AFTERNOON HOURS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 637 AM CDT TUE MAR 11 2014
COMPLEX AND MESSY AVIATION DAY ACROSS THE AREA TODAY. AREA OF RAIN
WILL SHIFT SOUTH ACROSS THE REGION TODAY...MIXING WITH SNOW AT TIMES.
VISIBILITY IS GENERALLY VFR...BUT WOULD EXPECT DROPS INTO THE MVFR
AND IFR RANGE WHEN AND IF SNOW MIXES IN. THE BAND OF PRECIPITATION IS
EXPECTED TO INTENSIFY THIS AFTERNOON SOUTH OF INTERSTATE 90...THUS
KSUX SEEMS TO HAVE TEH GREATEST POTENTIAL OF DROPPING INTO THE LIFR
RANGE IN A HEAVIER SNOW BURST...ALTHOUGH CONFIDENCE IN THIS REMAINS
PRETTY LOW. OTHERWISE IFR TO MVFR STRATUS IS CURRENTLY EXPANDING
ACROSS MUCH OF THE AREA. EXPECT TO SEE A RETURN TO VFR BEHIND THE
FRONT LATER TODAY FROM NORTH TO SOUTH...ALTHOUGH EXACTLY HOW QUICKLY
THIS AFTERNOON AND EVENING IS UNCERTAIN. ANOTHER ROUND OF SCATTERED
SNOW SHOWERS MAY ENTER THE AREA TOWARDS 12Z...WITH THE GREATEST
CHANCE AROUND KHON.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...
SHORT TERM...CHENARD
LONG TERM...
AVIATION...CHENARD
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
645 AM CDT TUE MAR 11 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 424 AM CDT TUE MAR 11 2014
COMPLEX FORECAST TODAY AS A BAND OF PRECIPITATION MOVES SOUTHEAST
ACROSS THE CWA. AS OF 4 AM THIS BAND IS ALONG AND NORTH OF HIGHWAY
14. THIS MATCHES WELL WITH A STRONG AREA OF MID LEVEL FRONTOGENESIS.
DECENT INSTABILITY ABOVE THE FRONT...THUS NOT SURPRISED BY THE HIGH
REFLECTIVITY CURRENTLY ON RADAR. BOUNDARY LAYER REMAINS QUITE
WARM...AND THUS PRECIPITATION TYPE IS CURRENTLY RAIN. THIS FIRST
AREA OF FRONTOGENESIS SHIFTS SOUTH THIS MORNING...BUT ALSO BEGINS TO
WEAKEN. THIS OCCURS AS THE MAIN WAVE EJECTS OUT OF THE
ROCKIES...WITH THE BEST QG FORCING SOUTH OF THE MISSOURI RIVER. THUS
MAKES SENSE THAT WE SEE FRONTOGENESIS INTENSIFY AGAIN SOUTH OF
INTERSTATE 90 AS MODELS SHOW. SO EXPECT WE SEE THE MODERATE TO HEAVY
BAND ALONG HIGHWAY 14 SLOWLY WEAKEN THIS MORNING AS IT MOVES
SOUTH...THEN INTENSIFY AGAIN THIS AFTERNOON SOUTH OF INTERSTATE 90
AS THE FRONT STRENGTHENS AND INTERACTS WITH THE UPPER WAVE. PRETTY
LARGE UNCERTAINTY ON HOW MUCH THE BAND WEAKENS THIS MORNING...AND
HOW QUICKLY IT INTENSIFIES THIS AFTERNOON. THIS IS IMPORTANT NOT
ONLY FOR QPF...BUT ALSO PRECIPITATION TYPE.
IF PRECIPITATION STAYS ON THE LIGHTER SIDE...IT WILL LIKELY STAY
MAINLY RAIN. ONLY EXPECTING A CHANGEOVER TO SNOW DUE TO DYNAMIC
COOLING IN THE HEAVIEST PRECIPITATION. SO IF THIS HEAVIER BAND
WEAKENS ENOUGH...OUR SNOW FORECAST COULD BE IN TROUBLE. THE LATEST
06Z NAM AND HRRR AND RAP DO SHOW THIS MORE PRONOUNCED WEAKENING...SO
WILL HAVE TO KEEP AN EYE ON THIS. EVEN AS THE BAND INTENSIFIES SOUTH
OF INTERSTATE 90 THIS AFTERNOON...BOUNDARY LAYER COULD BE WARM
ENOUGH TO KEEP THINGS RAIN...OR JUST A WET NON ACCUMULATING SNOW. SO
FOR NOW...WILL KEEP 1 TO 2 INCHES IN THE FORECAST FOR MOST OF THE
CWA...BUT WILL NEED TO MONITOR TEMPERATURE TRENDS THROUGH THE DAY.
FOLLOWED CLOSE TO THE ARW AND NAM FOR TIMING...WITH THE BAND
IMPACTING INTERSTATE 90 MID TO LATE MORNING...AND NORTHWEST IOWA
LATE MORNING INTO THE AFTERNOON. SKIES WILL STAY MOSTLY CLOUDY
TONIGHT...AND AS A SECONDARY WAVE DROP SOUTH...COULD SEE SOME
SCATTERED SNOW SHOWERS DEVELOP AFTER MIDNIGHT. BASED ON LATEST MODEL
RUNS DID SHIFT THIS SNOW SHOWER AREA FURTHER WEST FROM THE PREVIOUS
FORECAST...CENTERED MORE BETWEEN THE JAMES RIVER AND INTERSTATE 29
CORRIDOR.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 424 AM CDT TUE MAR 11 2014
FOR THE MEDIUM RANGE...HAVE SIDED CLOSER TO A BLEND OF THE
CANADIAN/GFS AND ECMWF. OPTED TO EXCLUDE THE NAM AS IT SEEMED TO BE
THE OUTLIER IN TERMS OF THE PROGRESSION OF SYSTEMS AND SEEMED TO BE
SLOWER THAN THE OTHER SOLUTIONS. MODELS SUGGEST BAND OF LIGHT SNOW
SHOWERS EARLY ON WEDNESDAY THOUGH SATURATION IN THE DENDRITIC LAYER
APPEARS TO BE A SIGNIFICANT ISSUE. MODEL SOUNDINGS VARY FROM
SOLUTION TO SOLUTION...BUT IN GENERAL...ALL HINT AT ONLY A LIMITED
AMOUNT OF THE DENDRITIC LAYER SATURATING AND WITH THE WARMER AIR
BEGINNING TO RETURN IT APPEARS AS THOUGH THE CHANCE OF DEVELOPING
THROUGHOUT THE MORNING DECREASES WITH TIME. HAVE KEPT LOW CHANCE
POPS THROUGH THE EARLY MORNING HOURS...BUT DROPPED TO FLURRIES IN
THE LATE MORNING IF ANYTHING IS LEFT BY THEN. EXPECT NICE WARMING
WEDNESDAY INTO THURSDAY...HOWEVER STRATUS MAY LINGER AHEAD OF THE
WARM FRONT ACROSS THE EASTERN CWA ON WEDNESDAY LIMITING WARMING
POTENTIAL. WARMED HIGHS ON THURSDAY WITH CLEAR SKIES AND NICE
SOUTHWEST FLOW ALOFT RESULTING IN 925 HPA TEMPS WARMING INTO THE
10-13C RANGE.
COLD FRONT MOVES THROUGH THE AREA ON THURSDAY NIGHT. SHORT WAVE
MOVES THROUGH MINNESOTA LATE THURSDAY NIGHT INTO FRIDAY. FOR THE
MOST PART...IT APPEARS AS THOUGH THE WAVE IS FOCUSED EAST OF THE
FORECAST AREA...SO LEFT FORECAST DRY FOR THE TIME BEING. BACK DOOR
COLD FRONT MOVES INTO THE UPPER MIDWEST FRIDAY NIGHT. FRONT WORKS
BACK TO THE WEST ON SATURDAY...WITH COOL NORTHEAST FLOW EAST OF THE
FRONT. A SERIES OF SHORT WAVES APPEAR TO MOVE THROUGH THE AREA ON
SATURDAY NEAR THE FRONT...POTENTIALLY CREATING SOME LIGHT RAIN/SNOW
DEPENDING WHICH SIDE OF THE FRONT A PARTICULAR LOCATION IS ON. THE
FRONT BEGINS TO SHIFT EAST ACROSS THE REGION ON SUNDAY LEADING TO A
WARMING TREND. STRONG SOUTHERLY FLOW DEVELOPS ON MONDAY...LEADING A
WARM BUT WINDY DAY. INCREASED WINDS ON MONDAY COMPARED TO THE
GUIDANCE BUT MAY NOT HAVE INCREASED ENOUGH WITH 20-30 KNOTS OF FLOW
THROUGH THE AFTERNOON HOURS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 637 AM CDT TUE MAR 11 2014
COMPLEX AND MESSY AVIATION DAY ACROSS THE AREA TODAY. AREA OF RAIN
WILL SHIFT SOUTH ACROSS THE REGION TODAY...MIXING WITH SNOW AT TIMES.
VISIBILITY IS GENERALLY VFR...BUT WOULD EXPECT DROPS INTO THE MVFR
AND IFR RANGE WHEN AND IF SNOW MIXES IN. THE BAND OF PRECIPITATION IS
EXPECTED TO INTENSIFY THIS AFTERNOON SOUTH OF INTERSTATE 90...THUS
KSUX SEEMS TO HAVE TEH GREATEST POTENTIAL OF DROPPING INTO THE LIFR
RANGE IN A HEAVIER SNOW BURST...ALTHOUGH CONFIDENCE IN THIS REMAINS
PRETTY LOW. OTHERWISE IFR TO MVFR STRATUS IS CURRENTLY EXPANDING
ACROSS MUCH OF THE AREA. EXPECT TO SEE A RETURN TO VFR BEHIND THE
FRONT LATER TODAY FROM NORTH TO SOUTH...ALTHOUGH EXACTLY HOW QUICKLY
THIS AFTERNOON AND EVENING IS UNCERTAIN. ANOTHER ROUND OF SCATTERED
SNOW SHOWERS MAY ENTER THE AREA TOWARDS 12Z...WITH THE GREATEST
CHANCE AROUND KHON.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...
AVIATION...CHENARD
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
425 AM CDT TUE MAR 11 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 424 AM CDT TUE MAR 11 2014
COMPLEX FORECAST TODAY AS A BAND OF PRECIPITATION MOVES SOUTHEAST
ACROSS THE CWA. AS OF 4 AM THIS BAND IS ALONG AND NORTH OF HIGHWAY
14. THIS MATCHES WELL WITH A STRONG AREA OF MID LEVEL FRONTOGENESIS.
DECENT INSTABILITY ABOVE THE FRONT...THUS NOT SURPRISED BY THE HIGH
REFLECTIVITY CURRENTLY ON RADAR. BOUNDARY LAYER REMAINS QUITE
WARM...AND THUS PRECIPITATION TYPE IS CURRENTLY RAIN. THIS FIRST
AREA OF FRONTOGENESIS SHIFTS SOUTH THIS MORNING...BUT ALSO BEGINS TO
WEAKEN. THIS OCCURS AS THE MAIN WAVE EJECTS OUT OF THE
ROCKIES...WITH THE BEST QG FORCING SOUTH OF THE MISSOURI RIVER. THUS
MAKES SENSE THAT WE SEE FRONTOGENESIS INTENSIFY AGAIN SOUTH OF
INTERSTATE 90 AS MODELS SHOW. SO EXPECT WE SEE THE MODERATE TO HEAVY
BAND ALONG HIGHWAY 14 SLOWLY WEAKEN THIS MORNING AS IT MOVES
SOUTH...THEN INTENSIFY AGAIN THIS AFTERNOON SOUTH OF INTERSTATE 90
AS THE FRONT STRENGTHENS AND INTERACTS WITH THE UPPER WAVE. PRETTY
LARGE UNCERTAINTY ON HOW MUCH THE BAND WEAKENS THIS MORNING...AND
HOW QUICKLY IT INTENSIFIES THIS AFTERNOON. THIS IS IMPORTANT NOT
ONLY FOR QPF...BUT ALSO PRECIPITATION TYPE.
IF PRECIPITATION STAYS ON THE LIGHTER SIDE...IT WILL LIKELY STAY
MAINLY RAIN. ONLY EXPECTING A CHANGEOVER TO SNOW DUE TO DYNAMIC
COOLING IN THE HEAVIEST PRECIPITATION. SO IF THIS HEAVIER BAND
WEAKENS ENOUGH...OUR SNOW FORECAST COULD BE IN TROUBLE. THE LATEST
06Z NAM AND HRRR AND RAP DO SHOW THIS MORE PRONOUNCED WEAKENING...SO
WILL HAVE TO KEEP AN EYE ON THIS. EVEN AS THE BAND INTENSIFIES SOUTH
OF INTERSTATE 90 THIS AFTERNOON...BOUNDARY LAYER COULD BE WARM
ENOUGH TO KEEP THINGS RAIN...OR JUST A WET NON ACCUMULATING SNOW. SO
FOR NOW...WILL KEEP 1 TO 2 INCHES IN THE FORECAST FOR MOST OF THE
CWA...BUT WILL NEED TO MONITOR TEMPERATURE TRENDS THROUGH THE DAY.
FOLLOWED CLOSE TO THE ARW AND NAM FOR TIMING...WITH THE BAND
IMPACTING INTERSTATE 90 MID TO LATE MORNING...AND NORTHWEST IOWA
LATE MORNING INTO THE AFTERNOON. SKIES WILL STAY MOSTLY CLOUDY
TONIGHT...AND AS A SECONDARY WAVE DROP SOUTH...COULD SEE SOME
SCATTERED SNOW SHOWERS DEVELOP AFTER MIDNIGHT. BASED ON LATEST MODEL
RUNS DID SHIFT THIS SNOW SHOWER AREA FURTHER WEST FROM THE PREVIOUS
FORECAST...CENTERED MORE BETWEEN THE JAMES RIVER AND INTERSTATE 29
CORRIDOR.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 424 AM CDT TUE MAR 11 2014
FOR THE MEDIUM RANGE...HAVE SIDED CLOSER TO A BLEND OF THE
CANADIAN/GFS AND ECMWF. OPTED TO EXCLUDE THE NAM AS IT SEEMED TO BE
THE OUTLIER IN TERMS OF THE PROGRESSION OF SYSTEMS AND SEEMED TO BE
SLOWER THAN THE OTHER SOLUTIONS. MODELS SUGGEST BAND OF LIGHT SNOW
SHOWERS EARLY ON WEDNESDAY THOUGH SATURATION IN THE DENDRITIC LAYER
APPEARS TO BE A SIGNIFICANT ISSUE. MODEL SOUNDINGS VARY FROM
SOLUTION TO SOLUTION...BUT IN GENERAL...ALL HINT AT ONLY A LIMITED
AMOUNT OF THE DENDRITIC LAYER SATURATING AND WITH THE WARMER AIR
BEGINNING TO RETURN IT APPEARS AS THOUGH THE CHANCE OF DEVELOPING
THROUGHOUT THE MORNING DECREASES WITH TIME. HAVE KEPT LOW CHANCE
POPS THROUGH THE EARLY MORNING HOURS...BUT DROPPED TO FLURRIES IN
THE LATE MORNING IF ANYTHING IS LEFT BY THEN. EXPECT NICE WARMING
WEDNESDAY INTO THURSDAY...HOWEVER STRATUS MAY LINGER AHEAD OF THE
WARM FRONT ACROSS THE EASTERN CWA ON WEDNESDAY LIMITING WARMING
POTENTIAL. WARMED HIGHS ON THURSDAY WITH CLEAR SKIES AND NICE
SOUTHWEST FLOW ALOFT RESULTING IN 925 HPA TEMPS WARMING INTO THE
10-13C RANGE.
COLD FRONT MOVES THROUGH THE AREA ON THURSDAY NIGHT. SHORT WAVE
MOVES THROUGH MINNESOTA LATE THURSDAY NIGHT INTO FRIDAY. FOR THE
MOST PART...IT APPEARS AS THOUGH THE WAVE IS FOCUSED EAST OF THE
FORECAST AREA...SO LEFT FORECAST DRY FOR THE TIME BEING. BACK DOOR
COLD FRONT MOVES INTO THE UPPER MIDWEST FRIDAY NIGHT. FRONT WORKS
BACK TO THE WEST ON SATURDAY...WITH COOL NORTHEAST FLOW EAST OF THE
FRONT. A SERIES OF SHORT WAVES APPEAR TO MOVE THROUGH THE AREA ON
SATURDAY NEAR THE FRONT...POTENTIALLY CREATING SOME LIGHT RAIN/SNOW
DEPENDING WHICH SIDE OF THE FRONT A PARTICULAR LOCATION IS ON. THE
FRONT BEGINS TO SHIFT EAST ACROSS THE REGION ON SUNDAY LEADING TO A
WARMING TREND. STRONG SOUTHERLY FLOW DEVELOPS ON MONDAY...LEADING A
WARM BUT WINDY DAY. INCREASED WINDS ON MONDAY COMPARED TO THE
GUIDANCE BUT MAY NOT HAVE INCREASED ENOUGH WITH 20-30 KNOTS OF FLOW
THROUGH THE AFTERNOON HOURS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1034 PM CDT MON MAR 10 2014
VFR CONDITIONS ACROSS THE AREA AT THE START OF THE PERIOD WILL
DIMINISH INTO MVFR-IFR CATEGORY BY 12Z ALONG THE HIGHWAY 14 CORRIDOR
AS A BAND OF RAIN/SNOW DEVELOPS ACROSS THAT AREA. THE BAND OF PRECIP
WILL THEN TRACK SOUTH SOUTHEAST ACROSS THE REMINDER OF THE FORECAST
AREA THROUGH THE DAY TUESDAY. EXPECT THE LIGHT RAIN TO TRANSITION
FAIRLY QUICKLY TO A RAIN AND SNOW MIX THEN TO ENTIRELY SNOW AS THE
PRECIPITATION INTENSITY PICKS UP WITH STRONG LIFT ALOFT.
MVFR CEILINGS ARE EXPECTED TO BECOME WIDESPREAD WITH THE ARRIVAL OF
PRECIPITATION...WITH MVFR-IFR VISIBILITY IN SNOW. PERIODS OF IFR
CEILINGS AND LIFR VISIBILITY LIKELY IN HEAVIEST SNOW BANDS...THOUGH
LOWEST CONDITIONS ONLY EXPECTED TO LAST FOR 2-3 HOURS AT ANY ONE
LOCATION. WINDS WILL ALSO BE ON THE INCREASE FROM THE NORTH DURING
THE DAYTIME ON TUESDAY WITH GUSTS CLOSE TO 30 KT LIKELY. THIS COULD
CAUSE A LITTLE FURTHER REDUCTION IN VISIBILITY WHILE THE SNOW IS
FALLING...BUT BLOWING SNOW IS NOT EXPECTED TO BE AN ISSUE ONCE THE
SNOW IS ON THE GROUND DUE TO EXPECTED WET NATURE OF THIS SNOWFALL.
IMPROVEMENT BACK INTO VFR CATEGORY EXPECTED INTO FAR NORTHWEST PART
OF THE AREA AROUND KHON BY EARLY TUESDAY AFTERNOON...WITH IMPROVING
CONDITIONS EXPANDING NORTHWEST TO SOUTHEAST THROUGH THE AFTERNOON AND
EARLY EVENING HOURS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...
AVIATION...JH
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1253 PM CDT TUE MAR 11 2014
.UPDATE...
UPDATED FOR 18Z AVIATION DISCUSSION. ALSO REMOVED OKLAHOMA PANHANDLE
AND NORTH CENTRAL AND NORTHEAST TEXAS PANHANDLE COUNTIES FROM THE RED
FLAG WARNING. HIGH TEMPERATURES WERE ALSO INCREASED OVER MUCH OF THE
AREA.
&&
.AVIATION.../18Z TAFS/
NO SIGNIFICANT CHANGES WERE MADE TO THE 18Z TAF FORECAST AS WIND
GUSTS AND BLOWING DUST APPEAR TO BE THE MAIN FORECAST CHALLENGES.
NORTHWEST TO MOSTLY NORTH WINDS WITH GUSTS UP TO 50KTS CAN BE
EXPECTED AT ALL TAF LOCATIONS THROUGH 06Z. AN AVIATION WEATHER
WARNING IS IN EFFECT UNTIL 1AM.
THERE IS SOME CONCERN THAT MVFR CEILINGS MAY DEVELOP AS THE COLD
FRONT MOVES SOUTH...BUT NOT CONFIDENT ENOUGH TO INCLUDE AT THIS TIME.
WITH ANY BLDU THAT OCCURS...VISIBILITIES WILL DECREASE AND COULD DROP
SIGNIFICANTLY. AS AN EXAMPLE...PERRYTON, TEXAS IS CURRENTLY REPORTING
1 3/4SM. NORTHERLY SURFACE WINDS WILL DECREASE AFTER 06Z WITH GUSTS
STILL UP TO 30KTS NOT OUT OF THE QUESTION.
KNS
&&
.FIRE WEATHER...
CRITICAL FIRE WEATHER CONCERNS REMAIN FOR AREAS SOUTH OF A LINE FROM
DALHART TO CANADIAN WHICH IS SOUTH OF A COLD FRONT BEGINNING TO MOVE
ACROSS THE FAR NORTHERN PANHANDLES.
BEHIND THIS FRONT...RH VALUES HAVE BEEN ABLE TO RECOVER THUS CRITICAL
FIRE WEATHER CONDITIONS ARE NO LONGER ANTICIPATED AND THE RED FLAG
WARNING HAS BEEN CANCELLED FOR ALL OF THE OKLAHOMA PANHANDLE AS WELL
AS SHERMAN...HANSFORD..OCHILTREE...AND LIPSCOMB COUNTIES. A FIRE
DANGER STATEMENT HAS REPLACED THE CANCELLED RED FLAG WARNING FOR
THESE COUNTIES.
FOR THE REST OF THIS AFTERNOON AND EVENING...CRITICAL FIRE WEATHER
CONCERNS WILL REMAIN ESPECIALLY ACROSS THE SOUTHERN TEXAS PANHANDLE.
AS THE COLD FRONT SINKS SOUTH...THE COUNTIES BEHIND THE FRONT WILL
SEE RELATIVE HUMIDITIES INCREASE BUT WINDS WILL ALSO INCREASE AS
WELL. THE WORST CRITICAL FIRE WEATHER CONDITIONS ARE FORECAST TO BE
ACROSS THE SOUTHWEST TEXAS PANHANDLE WHERE THE LOWEST RH VALUES WILL
RESIDE (COUPLED WITH STRONG WINDS EXPECTED TO INCREASE).
KNS/JJ
&&
.DISCUSSION...
HIGH TEMPERATURES WERE INCREASED ACROSS THE ENTIRE AREA AND
ESPECIALLY ACROSS THE SOUTHERN TEXAS PANHANDLE WITH MID TO UPPER 70S
AND A FEW 80S EXPECTED. BEHIND THE COLD FRONT ACROSS THE OKLAHOMA
PANHANDLE AND FAR NORTHERN TEXAS PANHANDLE...HIGH TEMPERATURES WERE
INCREASED 1 TO 3 DEGREES BASED ON CURRENT TRENDS ALTHOUGH NOT
EXPECTING TOO MUCH MORE OF AN INCREASE AS THE COLD FRONT MOVES
THROUGH THESE AREAS.
ALL OTHER WEATHER PARAMETERS WERE TWEAKED BASED ON CURRENT TRENDS.
CLK/KNS
&&
.PREV DISCUSSION... /ISSUED 1030 AM CDT TUE MAR 11 2014/
FIRE WEATHER...
BIG CONCERN THIS AFTERNOON IS ON FIRE WEATHER POTENTIAL. DUE TO
SOUTHWEST WINDS BEHIND A SURFACE TROUGH, OVERNIGHT RELATIVE HUMIDITY
RECOVERIES WERE VERY POOR FOR LOCATIONS ON THE CAPROCK WITH RELATIVE
HUMIDITY VALUES ONLY CLIMBING UP TO 35%. SEVERAL LOCATIONS EVEN
STAYED BELOW 30% ALL NIGHT. RECOVERIES WERE SLIGHTLY HIGHER AHEAD OF
THE SURFACE TROUGH ACROSS THE EASTERN PANHANDLES WHERE RELATIVE
HUMIDITY VALUES RANGED BETWEEN 50 AND 80%. WHAT THIS ESSENTIALLY
MEANS IS THAT FINE FUEL MOISTURE NEVER HAD A CHANCE TO MOISTEN AT ALL
FOR MOST LOCATIONS OVERNIGHT. RELATIVE HUMIDITY VALUES WILL CONTINUE
TO REMAIN VERY LOW FOR MUCH OF THE DAY UNTIL A COLD FRONT PASSES
THROUGH LATER TODAY. SPEAKING OF THE COLD FRONT, IT CURRENTLY
STRETCHES FROM NEAR HILL CITY, KS TO GARDEN CITY, KS TO SPRINGFIELD,
CO. THIS FRONT WILL ENTER OUR FORECAST AREA AFTER 11 AM, AND MOVE
SOUTHWARD THROUGH THE AFTERNOON.
APPROXIMATE COLD FRONT TIMING:
GUYMON: 1 PM
DALHART AND PERRYTON: 1-2 PM
DUMAS, BORGER, AND PAMPA: 3-4 PM
AMARILLO: 4-5 PM
SHAMROCK: 5-6 PM
HEREFORD: 6-7 PM
ONE OF THE BIGGEST QUESTION MARKS IS HOW STRONG WINDS WILL BE THIS
AFTERNOON AHEAD OF THE FRONT. RAW RUC AND NAM SOUNDINGS SUGGEST
MARGINAL WINDS FOR RED FLAG CONDITIONS IN OUR AREA. HOWEVER, PREFER
THE HIGHER MET AND MAV WINDS (WHICH IS CURRENTLY IN THE FORECAST) AS
MOS GUIDANCE TENDS TO DO RELATIVELY WELL ON THESE DOWNSLOPE WIND
DAYS. WILL LEAVE THE RED FLAG WARNING IN TACT, BUT OUR HIGHEST
CONFIDENCE FOR SEEING CRITICAL FIRE WEATHER CONDITIONS WILL BE SOUTH
OF A CLAYTON TO CANADIAN LINE.
THE ROLLER COASTER RIDE OF FUEL MOISTURE OVER THE LAST MONTH IS
CLEARLY SEEN IN TEXAS FOREST SERVICE ENERGY RELEASE COMPONENT (ERC)
DATA. AFTER LAST WEEK`S MOISTURE, WE HAVE QUICKLY DRIED OUT AGAIN. IN
FACT, FORECAST ERC VALUES TODAY ARE 67 AT BOOTLEG, 62 AT CEDAR, AND
60 AT WHEELER. THESE VALUES ARE GETTING VERY CLOSE TO THE 90%
PERCENTILE, AT WHICH LOCAL RESEARCH SUGGESTS SIGNIFICANT FIRE
POTENTIAL BECOMES AN INCREASING CONCERN. WITH THESE DRYING FUELS AND
A LITTLE MORE FAVORABLE FIRE WEATHER CONDITIONS, IT`S NOT A BIG
SURPRISE THAT WE SAW A SLIGHT UPTICK IN INITIAL ATTACK ACTIVITY
YESTERDAY. TFS SIGNIFICANT FIRE POTENTIAL MATRICES SHOW A MODERATE TO
NEAR HIGH POTENTIAL FOR SIGNIFICANT FIRE TODAY, ESPECIALLY ACROSS THE
FAR SOUTHWESTERN TEXAS PANHANDLE. THE AXIS OF A BROAD 850 MB THERMAL
RIDGE WILL STRETCH FROM NORTHEASTERN NEW MEXICO INTO THE SOUTHWESTERN
TEXAS PANHANDLE INTO THE SOUTH PLAINS. THE ALIGNMENT OF THE STRONGEST
LOW-/MID-LEVEL WINDS WILL GENERALLY OCCUR ALONG AND SOUTH OF THIS
AXIS. IT IS ALSO IN THESE LOCATIONS THAT TEMPERATURES WILL BE 5 TO 15
DEGREES ABOVE NORMAL, WHICH ALSO SUPPORTS HIGHER FIRE DANGER PER
LOCAL RESEARCH. THEREFORE, BASED ON FUELS AND WEATHER, THE HIGHEST
PROBABILITIES (AND THEY ARE STILL ON THE LOW SIDE) OF SIGNIFICANT
FIRE WEATHER POTENTIAL WILL REMAIN SOUTH AND WEST OF A HEREFORD TO
HAPPY LINE. DESPITE THIS, FIRE OFFICIALS AND EMERGENCY MANAGERS
SHOULD REMAIN ON HEIGHTENED ALERT, ESPECIALLY CONSIDERING THAT WINDS
WILL SHIFT FROM THE NORTHWEST TO THE NORTH AND INCREASE SUBSTANTIALLY
(GUSTS UP TO 60 MPH) BEHIND THE COLD FRONT LATER THIS AFTERNOON AND
EVENING. THIS WILL BE OF UTMOST IMPORTANCE IN THE EVENT OF ANY FIRE
STARTS OR ONGOING FIRES BEFORE THEN!
JACKSON
&&
.PREV DISCUSSION... /ISSUED 641 AM CDT TUE MAR 11 2014/
AVIATION...
12Z TAFS...WEST WINDS INITIALLY THIS MORNING WILL VEER TO THE
NORTHWEST BY MID TO LATE MORNING AND INCREASE TO 20-25 KTS WITH GUSTS
OF 30-35 KTS. A COLD FRONT WILL WORK SOUTH THROUGH THE AREA THIS
AFTERNOON...WITH WINDS TURNING TO THE NORTH BEHIND THE FRONT AND
INCREASING TO NEAR 35 KTS WITH GUSTS TO AROUND 50 KTS POSSIBLE. SOME
VSBY REDUCTIONS WILL BE POSSIBLE FROM BLDU BEHIND THE FRONT THIS
AFTERNOON AND EVENING. WINDS WILL DECREASE FROM NORTH TO SOUTH LATE
THIS EVENING AND OVERNIGHT. OUTSIDE OF ANY BLDU...VFR CONDITIONS ARE
EXPECTED. AN AVIATION WEATHER WARNING IS IN EFFECT FOR KAMA FROM 22Z
TODAY THROUGH 06Z WEDNESDAY FOR THE STRONG WINDS.
KB
&&
.PREV DISCUSSION... /ISSUED 406 AM CDT TUE MAR 11 2014/
DISCUSSION...
UPPER LEVEL SHORT WAVE TROUGH OVER WYOMING NOW WILL ELONGATE AND
SPLIT AS IT DIVES SOUTH THROUGH COLORADO AND KANSAS TODAY. A
POWERFUL COLD FRONT WILL BLAST ITS WAY SOUTH ACROSS THE PANHANDLES
THIS AFTERNOON AND EVENING IN ASSOCIATION WITH THE PASSAGE OF THE
SHORT WAVE TROUGH. SURFACE PRESSURE GRADIENT IS VERY TIGHT BETWEEN
LOW PRESSURE OVER NORTH CENTRAL TEXAS AND HIGH PRESSURE OVER
WYOMING BY LATE THIS AFTERNOON AND EARLY THIS EVENING. THIS TIGHT
PRESSURE GRADIENT IS EXPECTED TO BRING NORTH WINDS OF 30 TO 40 MILES
AN HOUR ACROSS THE PANHANDLES WITH GUST TO AROUND 60 MILES AN HOUR
IN SOME SPOTS. HAVE GONE AHEAD AND TURNED THE HIGH WIND WATCH INTO
A HIGH WIND WARNING FOR MUCH OF THE CWA. ONLY THE FAR EAST CENTRAL
AND SOUTHEAST TEXAS PANHANDLE WILL BE IN A WIND ADVISORY. BLOWING
DUST MAY ALSO REDUCE VISIBILITIES TO ONE MILE OR LESS AT TIMES. RED
FLAG WARNING CRITERIA IS ALSO EXPECTED TO BE MET ACROSS THE CWA
TODAY AS RELATIVE HUMIDITY VALUES DROP TO 15 PERCENT OR BELOW AHEAD
AND JUST BEHIND THE COLD FRONT. THE WIND SHIFT AND SUDDEN INCREASE
IN THE WIND WILL ALSO CAUSE UNPREDICTABLE FIRE BEHAVIOR SHOULD A
FIRE START.
WINDS WILL SLOWLY DECREASE AFTER MIDNIGHT AND SHOULD BE BELOW 20 MPH
BY MID MORNING ON WEDNESDAY.
THE MODELS STILL WANT TO PAINT SOME VERY LIGHT QPF...MAINLY ACROSS
THE NORTHERN CWA...THURSDAY NIGHT INTO FRIDAY IN ASSOCIATION WITH
THE SECOND SHORT WAVE TROUGH APPROACHING FROM THE WEST. FOR NOW
WILL LEAVE THE FORECAST DRY AS IT LOOKS LIKE MOISTURE WILL BE
LACKING.
THE NEXT SYSTEM TO AFFECT THE PANHANDLES WILL ARRIVE BY THE SECOND
HALF OF THE WEEKEND. THIS SYSTEM SLIDES SOUTHEAST ON THE EAST SIDE
OF A WEST COAST RIDGE AND IT INTENSIFIES AS IT MOVES INTO THE
SOUTHERN HIGH PLAINS. AGAIN...THE MODELS WANT CHANGE THEIR TUNE
SINCE IT IS A NEW DAY. THEREFORE...WILL NOT INSERT ANY PRECIP FOR
LATE NEXT WEEKEND AT THIS TIME.
.FIRE WEATHER...
CRITICAL FIRE WEATHER CONDITIONS WILL BE FOUND ACROSS THE
PANHANDLES TODAY AND THIS EVENING. LOWEST AFTERNOON RELATIVE
HUMIDITY VALUES WILL GET DOWN INTO THE 5 TO 15 PERCENT RANGE
ACROSS MUCH OF THE PANHANDLES. RELATIVE HUMIDITY VALUES WILL
START TO RECOVER SOME BEHIND A COLD ACROSS THE OKLAHOMA
PANHANDLE AND THE NORTHERN TEXAS PANHANDLE BY MID AFTERNOON...
BUT WINDS WILL BE INCREASING BEHIND THE COLD FRONT SO ANY
ONGOING FIRES COULD HAVE ERRATIC BEHAVIOR DUE TO THE SHIFTING
WINDS WITH THE FRONT.
WINDS WILL DECREASE SLOWLY AFTER MIDNIGHT TONIGHT AND THEY
WILL BE BELOW 15 MPH BY AROUND MID MORNING ON WEDNESDAY.
ELEVATED FIRE WEATHER CONDITIONS WILL BE POSSIBLE ACROSS THE
PANHANDLES AGAIN ON THURSDAY AS SOUTHWEST WINDS INCREASE AND
RELATIVE HUMIDITY VALUES DROP.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...HIGH WIND WARNING UNTIL 1 AM CDT WEDNESDAY FOR THE FOLLOWING
ZONES: CARSON...DALLAM...DEAF SMITH...GRAY...HANSFORD...
HARTLEY...HUTCHINSON...LIPSCOMB...MOORE...OCHILTREE...
OLDHAM...POTTER...RANDALL...ROBERTS...SHERMAN.
RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES: ARMSTRONG...CARSON...COLLINGSWORTH...DALLAM...DEAF
SMITH...DONLEY...GRAY...HARTLEY...HEMPHILL...HUTCHINSON...
MOORE...OLDHAM...POTTER...RANDALL...ROBERTS...WHEELER.
WIND ADVISORY UNTIL 1 AM CDT WEDNESDAY FOR THE FOLLOWING ZONES:
ARMSTRONG...COLLINGSWORTH...DONLEY...HEMPHILL...WHEELER.
OK...HIGH WIND WARNING UNTIL 1 AM CDT WEDNESDAY FOR THE FOLLOWING
ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
KNS/CLK/JJ
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1224 PM CDT TUE MAR 11 2014
.UPDATE...
INITIAL MIXING THIS PRODUCED SLIGHTLY STRONGER WINDS THAN
EXPECTED...MAINLY FROM DENVER CITY THROUGH LUBBOCK TOWARD FLOYDADA
AND SILVERTON...WHERE LOW END ADVISORY CRITERIA WAS SEEN AT TIMES.
SODAR AT REESE CENTER SHOWING WINDS ALOFT WEAKENING SOME WHILE AT
THE SFC INITIAL WIND SHIFT AHEAD OF THE STRONG COLD FRONT STILL
BACK FURTHER TO THE NORTH SHOULD PRODUCE A WEAKNESS IN THE
PRESSURE GRADIENT THAT ALSO POINTS TO WINDS DECREASING INTO THE
FCST WIND SPEED RANGE BY EARLY AFTN. AS A RESULT WILL NOT MAKE ANY
CHANGES TO THE FIRST PERIOD FCST ATTM.
&&
.AVIATION...
GUSTY WEST WINDS TO BECOME NW THIS AFTN THEN NORTH THIS EVENING
PRETTY MUCH AS EXPECTED. BLOWING DUST AT KLBB CAME EARLIER AND
DENSER THAN INITIALLY EXPECTED...BUT APPEARS WINDS WILL WEAKEN
JUST ENOUGH EARLY IN THE PERIOD TO SEE SFC VSBY INCREASE TO 5SM OR
GREATER BEFORE COMING BACK DOWN THIS EVENING BEHIND THE STRONG
COLD FRONT.
&&
.PREV DISCUSSION... /ISSUED 700 AM CDT TUE MAR 11 2014/
AVIATION...
GUSTY WEST TO NORTHWEST WINDS ARE EXPECTED FOR MOST OF THE DAY
TODAY. PATCHY BLDU MAY CAUSE LOCAL VSBY REDUCTIONS. THIS
EVENING...A STRONG COLD FRONT WILL QUICKLY PASS THROUGH THE AREA.
SUSTAINED WIND SPEEDS COULD APPROACH 30 KTS AT EITHER OR BOTH
TERMINALS AND REQUIRE AN AIRPORT WEATHER WARNING. ALSO...THERE
WILL LIKELY BE A PERIOD OF HIGHER DUST CONCENTRATIONS WHICH COULD
RESULT IN MVFR VSBYS AT KLBB. WINDS WILL SLOWLY DECREASE WEDNESDAY
MORNING AND THE DUST WILL SETTLE. VFR CONDITIONS ARE EXPECTED FOR
THE REMAINDER OF THE FORECAST.
PREV DISCUSSION... /ISSUED 403 AM CDT TUE MAR 11 2014/
SHORT TERM...
THE STAGE IS SET FOR A EARLY SPRING STRONG WIND/BLOWING DUST AND
FIRE WEATHER EVENT TODAY AND TONIGHT. 3 AM SAT IMAGERY AND UPPER-AIR
ANALYSIS SHOW A SHARP SHORTWAVE MOVING QUICKLY THROUGH THE
INTER-MOUNTAIN WEST. THIS WAVE WILL MOVE ROUGHLY EWD INTO THE
CENTRAL PLAINS TODAY...PLACING THE CWA ON THE SRN FLANK OF THE
MID-LVL JET MAX WITHIN THE BASE OF THE TROUGH. IN ADDITION...A WEAK
SFC TROUGH EXTENDING SWD FROM A LOW IN FAR NE COLO THROUGH THE WRN
PANHANDLES INTO ERN NM WILL DEEPEN AND MOVE EAST TODAY. TIGHTENING
THE SFC PRESSURE GRADIENT WHILE WINDS SWING AROUND TO THE WEST THEN
W-NW. FINALLY...A STRONG COLD FRONT IS MOVING INTO NRN COLO AND WRN
NE...THIS FRONT WILL BE THE MAIN DRIVER OF STRONG WINDS THIS
EVENING/TONIGHT...MORE ON THAT LATER.
WINDS ARE EXPECTED TO PICK UP PRETTY QUICKLY THIS MORNING...THE WEST
TEXAS SODAR AT REESE CENTER ALREADY SHOWS 30+ KTS AT 500 FT AGL.
WHILE WE DO HAVE SOME SHALLOW MOISTURE IN PLACE ACROSS THE ERN CWA
THIS MORNING...UNFORTUNATELY...THIS MOISTURE WILL BE SCOURED OUT
QUICKLY AND CRITICAL FIRE WEATHER CONDITIONS COULD DEVELOP BEFORE
NOON /SEE DISCUSSION BELOW/. IN GENERAL...WE EXPECT WINDS TO RISE
INTO THE 25 TO 35 MPH RANGE ACROSS THE AREA TODAY...SLIGHTLY
LOWER IN THE ROLLING PLAINS AND SLIGHTLY MORE ACROSS THE W-SW.
THESE WINDS WILL LIKELY REMAIN JUST BELOW ADVISORY LEVELS BUT
SHOULD BE SUFFICIENT TO LOFT SOME PATCHY BLOWING DUST. TEMPS WILL
BE QUITE WARM FOR MOST OF THE AREA...WITH HIGHS IN THE
80S...PERHAPS PUSHING 90F IN THE SRN ROLLING PLAINS...WHILE CAA
COMING IN FROM THE NW SHOULD KEEP TEMPS IN THE 70S ACROSS THE FAR
SW TX PANHANDLE AND WRN SPLNS.
LATE THIS AFTERNOON...ATTENTION WILL TURN TO THE COLD FRONT WHICH IS
EXPECTED TO BE BARRELING SOUTH THROUGH THE PANHANDLES. WHILE
GUIDANCE IS IN GOOD AGREEMENT THAT THE FRONT/S PROGRESS WILL BE
QUICKER IN THE EAST...LAGGING IN THE WEST...THERE IS STILL A FEW
HOURS OF DISAGREEMENT IN THE TIMING OF THE FRONT. WE ARE FAVORING
THE HIGH-RES GUIDANCE FROM THE RAP AND THE TTU-WRF...WHICH SHOWS THE
FRONT ENTERING CHILDRESS COUNTY AROUND 23 UTC...AND PARMER COUNTY
AROUND 00 UTC. BUT OF COURSE THE ACTUAL FROPA COULD VARY A COUPLE
HOURS EITHER WAY. AS NOTED PREVIOUSLY...MODELS ARE SHOWING VERY
IMPRESSIVE PRESSURE RISES BEHIND THE FRONT THIS EVENING. OBJECTIVE
GUIDANCE SUGGESTS THAT WIND SPEEDS COULD REACH HIGH WIND CRITERIA
/SUSTAINED SPEED OF AT LEAST 40 MPH AND/OR GUSTS IN EXCESS OF 57
MPH/ ACROSS THE NRN HALF OF THE FA. WE ARE A LITTLE SKEPTICAL THAT
WE WILL SEE SUSTAINED HIGH WINDS IN THE LOWER TERRAIN OF THE ROLLING
PLAINS...BUT WE ARE PLANNING ON EXTENDING THE HIGH WIND WATCH SOUTH
AND EAST ACROSS MUCH OF THE CAPROCK....WITH SOLID ADVISORY-LEVEL
WINDS EXPECTED ELSEWHERE.
SOMEWHAT INTERESTINGLY...THERE IS A PRONOUNCED WEAKNESS PROGGED IN
THE 800-700MB WIND FIELD ACROSS MUCH OF OUR AREA AROUND 0Z. THIS
SHOULD NOT HAVE MUCH OF AN IMPACT ON THE OVERALL FCST BUT DEPENDING
ON THE TIMING OF THE FRONT...IT COULD LEAD TO A SHORT-DURATION LULL
IN GUSTY WINDS BEFORE A BIG INCREASE WITH THE FROPA.
AS FOR BLOWING DUST...WE ARE LOOKING FOR A CONCENTRATION OF DIRT AND
REDUCTION IN VISIBILITY ALONG AND IMMEDIATELY IN THE WAKE OF THE
FRONT...BUT WE DON/T HAVE ANY STRONG INDICATIONS AT THIS TIME THAT
VISIBILITIES WILL DROP TO ADVISORY OR DUST STORM LEVELS. THIS IS
PARTLY DUE TO THE WIND DIRECTION AND OUR EXPECTATION THAT THE FRONT
WILL MOVE THROUGH AFTER PEAK MIXING. IF THE FRONT IS FASTER/STRONGER
THAN EXPECTED...THEN DENSE BLOWING DUST MAY BE A GREATER CONCERN.
LONG TERM...
AFTER THE ACTIVE SHORT TERM...THE EXTENDED FORECAST SEEMS RELATIVELY
BENIGN BY COMPARISON. GUSTY NORTHERLY WINDS EARLY WEDNESDAY WILL
GRADUALLY WEAKEN THROUGH THE DAY AS THE PRESSURE GRADIENT RELAXES
AND SURFACE RIDGING SETTLES SQUARELY OVER WEST TEXAS. IT WILL BE
CONSIDERABLY COOLER BEHIND THIS EVENINGS FROPA...WITH HIGHS ON
WEDNESDAY TOPPING OUT AROUND 10 DEGREES BELOW MID-MARCH AVERAGES.
SHORTWAVE RIDGING ALOFT WILL FOLLOW ON THURSDAY WHICH WHEN COUPLED
WITH RETURN FLOW ON THE BACK SIDE OF THE DEPARTING SURFACE RIDGE AND
RENEWED SURFACE TROUGHING IN THE LEE OF THE ROCKIES WILL MEAN BREEZY
SOUTHERLY WINDS WITH TEMPERATURES RECOVERING TO NEAR AVERAGE.
ATTENTION WILL THEN TURN WEST TO A CUTOFF UPPER LOW THAT WILL HANG
OUT OVER THE GREAT BASIN MID-WEEK. THIS UPPER LOW WILL GET KICKED
EASTWARD LATE WEEK AS JET ENERGY MOVES INTO THE PACIFIC NORTHWEST.
THERE REMAINS SOME TIMING DIFFERENCES...BUT WHAT IS LEFT OF THE
UPPER LOW WILL RACE ACROSS THE SOUTH PLAINS FRIDAY OR FRIDAY NIGHT.
UNFORTUNATELY...THIS SYSTEM WILL NOT HAVE MUCH IN THE WAY OF
LOW-LEVEL MOISTURE TO WORK WITH...BUT THE GFS AND ECMWF DO CONTINUE
TO PAINT POCKETS OF VERY LIGHT QPF SOMEWHERE IN OR NEAR THE CWA.
GIVEN THIS SIGNAL...WE WOULD NOT BE SURPRISED TO SEE A FEW SPRINKLES
OR LIGHT SHOWERS...BUT THE CHANCE OF MEASURABLE RAIN STILL APPEARS
LOW AND WE HAVE MAINTAINED POPS AROUND 10 PERCENT. THE TIMING
UNCERTAINTY WITH THE PASSING WAVE DOES ALSO CREATE LOWER CONFIDENCE
ON WHEN THE ASSOCIATED FROPA WILL OCCUR. A QUICKER SYSTEM/FRONT
COULD MEAN TEMPERATURES A LITTLE COOLER THAN WHAT IS CURRENTLY
DEPICTED IN THE FORECAST...THOUGH EITHER WAY THE SYSTEM WILL NOT
HAVE MUCH COOL AIR TO WORK WITH.
THE FIRST HALF OF THE WEEKEND WILL START OUT ON THE MILD SIDE...WITH
HIGHS EXPECTED TO TOP OUT IN THE 60S AND LOWER 70S. HOWEVER...A
SHORTWAVE TROUGH IS PROGGED TO DIVE SOUTH-SOUTHEASTWARD TOWARD THE
REGION SATURDAY NIGHT. AT A MINIMUM...THIS DISTURBANCE SHOULD HELP
DRIVE A DECENT COLD FRONT THROUGH...DROPPING TEMPERATURES BACK BELOW
AVERAGE FOR THE SECOND HALF OF THE WEEKEND. LESS CERTAIN IS EXACTLY
WHAT LONGITUDE THIS DISTURBANCE PASSES AND THUS WHETHER OR NOT IT
CAN BRING A WINDOW FOR PRECIPITATION CHANCES TO THE SOUTH PLAINS.
THE MOST RECENT ECMWF HAS TRENDED BACK FURTHER WEST AND
WETTER...WHILE THE GFS TRACK IS MORE EASTWARD WHICH WOULD LIKELY BE
DRY FOR THE SOUTH PLAINS. WE HAVE MAINTAINED SILENT POPS AROUND 10
PERCENT FOR NOW AND WILL WAIT TO MAKE A MOVE ONE WAY OR THE OTHER UNTIL
THE NWP CAN COME INTO BETTER AGREEMENT. REGARDLESS...WARMER AND
DRY WEATHER SHOULD KICK OFF EARLY NEXT WEEK AS THE UPPER TROUGH
DEPARTS AND SOUTHERLY TO SOUTHWESTERLY SURFACE FLOW REDEVELOPS.
FIRE WEATHER...
LATEST INDICATIONS ARE THAT CRITICAL FIRE WEATHER CONDITIONS WILL
DEVELOP ACROSS THE ENTIRE SOUTH PLAINS AREA TODAY AND WE WILL EXPAND
AND UPGRADE THE WATCH TO A RED FLAG WARNING FOR OUR WHOLE CWA.
DESPITE HIGH RH VALUES ACROSS THE EASTERN SOUTH PLAINS AND ROLLING
PLAINS EARLY THIS MORNING...VERY DRY AIR WILL SPREAD EAST RESULTING
IN RH VALUES DROPPING UNDER 15 PERCENT BY 10 AM FOR MANY AREAS...AND
INTO THE SINGLE DIGITS ACROSS THE ENTIRE AREA THIS AFTERNOON. WHILE
WIND SPEEDS MAY BE ON THE LOW END OF CRITERIA ACROSS THE ERN ROLLING
PLAINS...IT APPEARS THAT WIND SPEEDS AND RH VALUES WILL SUPPORT AN
EXTREMELY CRITICAL DANGER FOR MUCH OF THE SOUTHWEST AND SOUTHERN
SOUTH PLAINS. WINDS MAY RELAX FOR A PERIOD AROUND 6 TO 7 PM...BUT
THE PASSAGE OF A STRONG COLD FRONT IN THE EVENING WILL BRING AN
ABRUPT WIND SHIFT TO THE NORTH AND MUCH STRONGER WINDS SPEEDS.
ALTHOUGH COOLING TEMPS AND RISING RH VALUES WILL BEGIN TO REDUCE
THE FIRE DANGER...WE WILL KEEP THE RED FLAG WARNING GOING THROUGH
9 PM CDT DUE TO THIS STRONG FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 71 25 52 24 60 / 0 0 0 0 0
TULIA 76 28 54 25 63 / 0 0 0 0 0
PLAINVIEW 77 29 55 26 63 / 0 0 0 0 0
LEVELLAND 78 30 54 26 63 / 0 0 0 0 0
LUBBOCK 80 32 56 28 64 / 0 0 0 0 0
DENVER CITY 80 31 55 25 61 / 0 0 0 0 0
BROWNFIELD 81 33 56 26 63 / 0 0 0 0 0
CHILDRESS 83 34 58 31 65 / 0 0 0 0 0
SPUR 85 35 58 30 65 / 0 0 0 0 0
ASPERMONT 88 36 58 29 65 / 0 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 10 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES: TXZ021>044.
WIND ADVISORY FROM 7 PM THIS EVENING TO 3 AM CDT WEDNESDAY FOR
THE FOLLOWING ZONES: TXZ021>044.
&&
$$
07
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1101 AM CDT TUE MAR 11 2014
.UPDATE...
LOW CLOUDS ALONG AND EAST OF I-35 WILL CONTINUE TO DISSIPATE
THROUGH MIDDAY WITH GENERALLY MOSTLY SUNNY SKIES DURING THE AFTERNOON.
SURFACE LOW PRESSURE NEAR GAGE OKLAHOMA WILL CONTINUE TO DEEPEN
AND WINDS ACROSS THE REGION WILL INCREASE. STILL EXPECT A DRYLINE
TO MOVE INTO THE WESTERN TWO TIER OF COUNTIES WITH BRISK SOUTHWEST
TO WEST WINDS DURING THE AFTERNOON. DUE TO THE DRIER AIR OUT WEST
AND AREA WINDS INCREASING...THE FIRE DANGER WILL BE HIGH GENERALLY
WEST OF I-35/I-35E AND DOES WARRANT THE CURRENT GRASS FIRE DANGER
STATEMENT. IF SUSTAIN WINDS INCREASE ABOVE 20 MPH FOR A FEW
HOURS...THEN WE WOULD LIKELY UPGRADE TO A RED FLAG WARNING FOR
SOME COUNTIES THROUGH THE REMAINDER OF THE AFTERNOON.
ONE MAJOR FIRE WEATHER CONCERN WOULD BE IF A WILDFIRE STARTED
JUST AHEAD OF FROPA. THIS WOULD CREATE A VERY DANGEROUS SITUATION
FOR FIREFIGHTERS DURING INITIAL ATTACK AS THE FRONTAL WIND SHIFT
WOULD SIGNIFICANTLY CHANGE THE FIRE/S MOVEMENT AND PROGRESSION.
CURRENT WIND ADVISORY TIMING LOOKS GOOD AND WILL ONLY MODIFY ITS
WORDING TO CLEARLY STATE THE TIMING OF THE FRONT AND ARRIVAL OF
THE STRONG WINDS. 75
&&
.AVIATION...
MID CLOUD HAS DISSIPATED OVER METROPLEX AND I CAN NOW SEE THE
STRATUS. ONE PATCH OF IFR CLOUDS IS MOVING NORTH INTO THE
SOUTHERN METROPLEX...AND HAVE ADDED A TEMPO FOR IFR CEILINGS THIS
MORNING. WITH STRONG SOUTHWEST FLOW JUST ABOVE THE
INVERSION...FEEL THAT WITH A BIT OF SUN THIS MORNING STRATUS WILL
QUICKLY MIX OUT AND SKIES WILL REMAIN CLEAR REST OF THE TAF
PERIOD.
WACO IFR WILL BE MORE PERSISTENT AND TAKE A COUPLE OF MORE HOURS
TO DISSIPATE...THEN THEY WILL ALSO REMAIN VFR FOR THE REST OF THE
TAF PERIOD.
STRONG COLD FRONT STILL PROGGED IN AROUND 10 PM/03Z FOR
METROPLEX...AND IT IS MOVING FAST ENOUGH THAT WACO WILL SEE IT
DURING THE SAME HOUR. WINDS WILL INCREASE SIGNIFICANTLY AN HOUR
OR TWO AFTER FROPA...BUT FORTUNATELY THEY WILL BE FROM THE NORTH
NORTHWEST AND NOT TOTALLY CROSS TO THE RUNWAYS. WINDS WILL LIKELY
REMAIN STRONG THROUGH MORNING...AND SLOWLY DIMINISH WEDNESDAY
BECOMING LIGHT AFTER SUNSET. 84
&&
.PREV UPDATE...
.UPDATE...
EARLY MORNING REGIONAL RADARS SHOWED SOME VERY LIGHT RAINFALL OVER
CENTRAL TEXAS...EXTENDING AS FAR NORTH AS A HILLSBORO TO ATHENS
LINE. THESE RAIN SHOWERS WERE ORIENTED ON THE NORTHERN PERIPHERY
OF A VORTICITY LOBE ASSOCIATED WITH AN UPPER LOW...ROUGHLY
CENTERED OVER AUSTIN ACCORDING TO 08Z WATER VAPOR SATELLITE
IMAGERY. 08Z SURFACE ANALYSIS SHOWED MILD TEMPERATURES ACROSS
NORTH AND CENTRAL TEXAS WITH MOST LOCATIONS HOLDING UP IN THE MID
TO UPPER 50S. 08Z OBJECTIVE ANALYSIS SHOWED RELATIVELY STRONG LEE
SIDE CYCLOGENESIS OVER THE SOUTHERN HIGH PLAINS WITH 3 HR PRESSURE
FALLS OF AROUND 4 MB NEAR AN ELONGATED AREA OF LOW PRESSURE OF 997
MB OVER THE OK AND TX PANHANDLES.
TODAY...THE PREVIOUS QUICK AFD WAS APPENDED BELOW. IN GENERAL OVER
THE NEXT 24 TO 36 HRS THE REGION IS EXPECTED TO BE AFFECTED BY A
DYNAMIC LOW PRESSURE SYSTEM WHICH WILL LEAD TO FIRE WEATHER DANGER
AND STRONG WIND CONCERNS FOR NORTH AND CENTRAL TEXAS. THE PRIMARY
UPPER LEVEL FEATURE DRIVING THESE CONDITIONS IS A STRONG SHORTWAVE
TROUGH OBSERVED OVER UTAH...MOVING EAST-SOUTHEAST PER WATER VAPOR
SATELLITE IMAGERY. 00Z UPPER AIR ANALYSIS OBSERVED A STRONG JET
STREAK IN EXCESS OF 100 KTS AT THE 250 MB LEVEL AT THE BASE OF
THIS TROUGH. THIS JET STREAK WAS LIKELY LOCATED OVER THE CENTRAL
AND SOUTHERN CONUS ROCKIES EARLY THIS MORNING...AIDING IN THE
STRONG LEE SIDE SURFACE CYCLOGENESIS OBSERVED ACROSS THE OK AND TX
PANHANDLES.
THE STRONG UPPER LEVEL TROUGH IS EXPECTED TO MOVE EAST OVER THE
CENTRAL PLAINS TODAY...DRIVING THE SURFACE CYCLONE EAST-SOUTHEAST
TOWARDS NORTH TX THIS AFTERNOON. OUT AHEAD OF THE FRONT...WINDS
ARE EXPECTED TO BECOME BREEZY AND SOUTH-SOUTHWESTERLY AT 15 TO 20
MPH. ALL GUIDANCE INDICATES AN H850 THERMAL RIDGE ORIENTED ALONG
AND SOUTH OF THE SURFACE CYCLONE...BUT THE STRENGTH OF THE THERMAL
RIDGE VARIES MODEL TO MODEL. HIGHER RESOLUTION MODEL GUIDANCE
GENERALLY FAVORS A STRONGER THERMAL RIDGE...SO THE HIGH
TEMPERATURE FORECAST FOR TODAY WAS BASED ON THE HIGH END OF THE
SPECTRUM OF AVAILABLE GUIDANCE. WENT AHEAD WITH HIGHS JUST ABOVE
90 DEGREES NEAR BRECKENRIDGE AND GRAHAM...AND IN THE MID TO UPPER
80S FOR MOST LOCATIONS ALONG AND WEST OF THE INTERSTATE 35
CORRIDOR. TO THE EAST...HIGHS WILL GENERALLY TOP OUT IN THE LOWER
80S TODAY...A BIT FARTHER REMOVED FROM THE DRIEST AIR AND STRONG
THERMAL RIDGE NEAR THE SURFACE LOW.
LOOKING AT FIRE WEATHER CONCERNS...ASSUMING HIGHS TOP OUT IN THE
MID 80S TO JUST ABOVE 90 DEGREES WEST OF INTERSTATE 35 AS
EXPECTED...GRASSY/FINE FUEL TEMPERATURES WILL GET QUITE WARM THIS
AFTERNOON. WINDS OF 15 TO 20 MPH COMBINED WITH AFTERNOON RELATIVE
HUMIDITY VALUES BELOW 30 PERCENT SUPPORT AT LEAST A HIGH FIRE
WEATHER DANGER ALONG AND WEST OF THE INTERSTATE 35 CORRIDOR...AND
A GRASS FIRE DANGER STATEMENT HAS BEEN ISSUED FOR THESE LOCATIONS
AS A RESULT. CRITICAL TO EXTREME FIRE WEATHER DANGER IS POSSIBLE
THIS AFTERNOON...BUT DEPENDENT UP ON THE STRENGTH OF WINDS AND
POSITION OF THE DRYLINE.
MOST MODEL GUIDANCE KEEPS WINDS BELOW RED FLAG WARNING CRITERIA
THIS AFTERNOON OVER THE WESTERN CWA. THIS IS PARTLY BECAUSE MODELS
HAVE A PART OF THE ELONGATED SURFACE LOW PRESSURE LOCATED VERY
NEAR WICHITA FALLS...GENERALLY REDUCING THE PRESSURE GRADIENT
FORCE THAT WOULD OTHERWISE ACCELERATE WINDS THE ADDITIONAL 5 TO 10
MPH NECESSARY TO REACH RED FLAG WARNING CRITERIA. HOWEVER IF THE
SURFACE LOW IS A BIT FARTHER NORTH...LIKE THE RAP AND HRRR
ADVERTISED AT THE TIME OF THIS DISCUSSION...EXTREME FIRE WEATHER
DANGER MAY BE REALIZED THIS AFTERNOON AND A RED FLAG WARNING MAY
NEED TO BE ISSUED.
THE HRRR IN PARTICULAR SHOWED A STRONG DRYLINE PUNCH INTO THE
WESTERN CWA...WITH THE DRYLINE PUSHING AS FAR EAST AS A JACKSBORO
TO LAMPASAS LINE BY 21Z. THE HRRR INCREASES WESTERLY WINDS AT THE
SURFACE TO 20 TO 25 KTS...OR STRONG ENOUGH FOR CRITICAL/EXTREME
FIRE DANGER WITH RELATIVE HUMIDITY VALUES CRASHING INTO THE SINGLE
DIGITS WEST OF THE DRYLINE. IF THESE HRRR CONDITIONS ARE
REALIZED...A RED FLAG WARNING WOULD CERTAINLY BE WARRANTED BECAUSE
ANY GRASS-FIRE IGNITED WOULD BE VERY DIFFICULT...IF NOT
IMPOSSIBLE...TO CONTROL. THIS IS DEFINITELY A WORST CASE
SCENARIO...AND IS NOT SUPPORTED BY ANY OTHER GUIDANCE AT THIS
TIME. REGARDLESS...THIS BEARS WATCHING CLOSELY THROUGHOUT THE DAY
AS THE HRRR WAS ALSO THE MOST RECENT GUIDANCE AVAILABLE AT THE
TIME OF THIS DISCUSSION.
THIS EVENING AND OVERNIGHT...THE SURFACE CYCLONE WILL CONTINUE
EAST THIS EVENING...WITH A STRONG COLD FRONT DROPPING SOUTH ACROSS
THE REGION IN ITS WAKE. WHILE MODELS DO NOT AGREE ON THE EXACT
TIMING OF THE FRONT YET...ALL MODELS AGREE THAT THE FRONT WILL BE
VERY FAST MOVING ONCE IT CROSSES THE RED RIVER THIS EVENING. WINDS
WILL SHIFT QUICKLY AROUND TO THE NORTH BEHIND THE FRONT...AND PICK
UP TO AT LEAST 20 MPH GUSTING ABOVE 30 MPH JUST BEHIND ITS LEADING
EDGE. WINDS ARE EXPECTED TO INCREASE IN INTENSITY BY ABOUT 10 MPH
OR SO AN HOUR OR TWO BEHIND THE INITIAL FRONTAL PASSAGE. SUSTAINED
WINDS OF 30 MPH...GUSTING TO 45 MPH AT TIMES ARE EXPECTED AT PEAK
INTENSITY OVERNIGHT.
CONFIDENCE IN STRONG WINDS IS VERY HIGH AT THIS TIME AS ALL MODEL
GUIDANCE SHOWS AT LEAST A 50 KT JET AT THE 850 MB LEVEL OVER THE
CWA BEHIND THE FRONT TONIGHT. HIGHER RESOLUTION GUIDANCE INDICATES
55 TO 60 KT JET FROM 09 TO 12Z OVER THE CWA WELL BEHIND THE FRONT.
WENT AHEAD WITH A WIND ADVISORY FOR THE ENTIRE CWA FROM 10 PM THIS
EVENING THROUGH 1 PM WEDNESDAY AS THIS APPEARED TO BE THE BEST
WINDOW FOR NORTH WINDS EXCEEDING 25 MPH OR GUSTING ABOVE 40 MPH.
THE START OR END TIMES OF THIS ADVISORY WILL LIKELY BE ADJUSTED BY
LATER SHIFTS AS THE EXACT TIMING OF THE FRONT IS BETTER RESOLVED.
WEDNESDAY AND THURSDAY...WEDNESDAY WILL START OFF WITH THE WIND
ADVISORY STILL IN EFFECT AS NORTH WINDS HOLD UP AROUND 25 MPH
GUSTING TO 40 MPH JUST AFTER SUNRISE...AND THEN SLOWLY DIMINISH
TO AROUND 20 MPH JUST AFTER NOON. WEDNESDAY WILL BE MUCH COOLER
WITH HIGHS GENERALLY HOLDING IN THE MID 50S WITH STRONG COLD AIR
ADVECTION IN PLACE. SKIES ARE EXPECTED TO STAY MOSTLY SUNNY ON
WEDNESDAY...WHICH WILL AT LEAST TAKE SOME OF THE BITE OUT OF THE
COOL...BREEZY AIR. HOWEVER...WINDS ARE EXPECTED TO BECOME LIGHT
AND VARIABLE BY EARLY THURSDAY MORNING...UNDER MOSTLY CLEAR SKIES.
THIS WILL BRING MANY LOCATIONS DOWN BELOW FREEZING WEDNESDAY
NIGHT...WITH THE EXCEPTION OF URBANIZED AREAS WHICH WILL STAY
WARMER DUE TO THE ABSORPTION OF SUNSHINE THROUGHOUT THE DAY ON
WEDNESDAY. LIGHT WINDS WILL BECOME SOUTHERLY ON THURSDAY AS
TEMPERATURES WARM INTO THE 60S.
FRIDAY AND FRIDAY NIGHT...MODELS CONTINUE TO INDICATE A RELATIVELY
COMPACT BUT STRONG SHORTWAVE TROUGH WILL MOVE OVER NORTH TEXAS
FRIDAY AFTERNOON OR EVENING. BOTH THE GFS AND ECMWF WERE
ADVERTISING SOME LIGHT QPF AMOUNTS ASSOCIATED WITH THIS TROUGH
WHICH IS DIFFERENT FROM PREVIOUS DAYS. THINK THE QPF
AMOUNTS...ALTHOUGH LIGHT...ARE STILL OPTIMISTIC BECAUSE TONIGHT`S
FRONT IS EXPECTED TO PLOW SOUTH ALL THE WAY ACROSS THE WESTERN
GULF OF MEXICO...EFFECTIVELY STUNTING OUR PRIMARY MECHANISM TO
RECHARGE THE LOWER TROPOSPHERE WITH WATER VAPOR.
THE SHORTWAVE TROUGH ITSELF IS EXPECTED TO ORIGINATE FROM THE
TROUGH THAT SENDS THE STRONG FRONT SOUTH ACROSS THE REGION
TONIGHT. IT IS EXPECTED TO BREAK OFF THE MAIN TROUGH AND REMAIN
QUASI-STEADY OVER THE SOUTHWESTERN CONUS FOR A COUPLE OF DAYS
BEFORE MOVING EAST WITH THE NEXT NORTHERN STREAM SHORTWAVE TROUGH
THURSDAY NIGHT INTO FRIDAY. THE ONLY REASON THIS MATTERS AT ALL IS
BECAUSE IT IS NOT LIKELY TO BE ASSOCIATED WITH A PLUME OF SOUTHERN
PACIFIC MOISTURE...SO THE ORIGIN OF THE RAPID MOISTENING OF THE
GFS AND ECMWF OUT AHEAD OF THE TROUGH IS A BIT OF A MYSTERY AT
THIS TIME. GRANTED...LIFT ASSOCIATED WITH THE TROUGH IS EXPECTED
TO BE STRONG...SO DYNAMIC LIFT...COOLING AND SATURATION FROM THE
BOTTOM UP...IS POSSIBLE.
WENT AHEAD WITH SOME 20 POPS FRIDAY AFTERNOON AND EVENING ACROSS
THE FAR EASTERN CWA DUE TO UNCERTAINTY REGARDING THE SOURCE REGION
OF MOISTURE FOR THE GFS AND ECMWF POP/QPF FORECAST. IF MOISTURE IS
JUST BEING UNDERESTIMATED IN GENERAL...POPS AND QPF MAY HAVE TO BE
BUMPED WEST IN LATER FORECASTS.
NEXT WEEKEND...A STRONG UPPER LEVEL TROUGH IS EXPECTED TO MOVE
FROM THE NORTHWEST CONUS SOUTHEAST TOWARDS THE SOUTHERN PLAINS
DURING THIS TIME. THE GFS CONTINUES TO BRING THIS TROUGH OVER
NORTH TX...OR JUST OFF TO THE SOUTHWEST. IN GENERAL...RESULTING
IN A WETTER FORECAST THAN IF THE TROUGH REMAINS TO THE NORTH OF
THE CWA. YESTERDAY THE OPERATIONAL GFS HAD ALMOST NO ENSEMBLE
SUPPORT FOR THIS SOLUTION...SO IT WAS LARGELY DISCOUNTED. HOWEVER
TODAY...ABOUT HALF OF THE GFS ENSEMBLE MEMBERS AGREE WITH THIS
SOLUTION...AND THE OPERATIONAL CANADIAN AND ECMWF HAVE SORT OF
COME ON BOARD AS WELL. /SORT OF/ IS USED BECAUSE THERE ARE SOME
FAIRLY LARGE TIMING AND STRENGTH DISCREPANCIES BETWEEN THESE
MODELS.
HOWEVER THE FORECAST TRACK OF THE UPPER TROUGH SEEMS TO BE THE
MAIN DIFFERENCE DICTATING A WET VERSUS DRY FORECAST...SO IT IS
GOOD TO SEE MODELS TRENDING TOWARDS A MORE SOUTHERLY TRACK AT THIS
TIME. QPF AMOUNTS ARE NOT VERY HIGH IN ANY OF THESE
SOLUTIONS...MOSTLY BECAUSE IN ALL SOLUTIONS THE UPPER TROUGH IS
POSITIVELY TILTED UNTIL IT MOVES EAST OF THE SOUTH PLAINS.
BUT...BEGGARS CANT BE CHOOSERS...AND WE REALLY NEED SOME RAIN...SO
WILL CONTINUE TO WATCH THE EVOLUTION OF THIS WEEKENDS TROUGH
CLOSELY IN THE COMING DAYS AND HOPE FOR THE BEST.
CAVANAUGH
&&
.PREV DISCUSSION... /ISSUED 328 AM CDT TUE MAR 11 2014/
IN THE SHORT TERM FORECAST THERE ARE TWO PRIMARY CONCERNS:
1. FIRE WEATHER DANGER WEST OF INTERSTATE 35 THIS AFTERNOON.
2. STRONG WINDS BEHIND A COLD FRONT LATE THIS EVENING THROUGH
WEDNESDAY MORNING.
WITH REGARDS TO FIRE WEATHER DANGER: WILL HOLD OFF ON ISSUING A
RED FLAG WARNING AT THIS TIME. FIRE WEATHER DANGER WILL BE HIGH TO
VERY HIGH WEST OF INTERSTATE 35 THIS AFTERNOON. CRITICAL OR
EXTREME FIRE WEATHER DANGER IS POSSIBLE FOR LOCATIONS GENERALLY
ALONG AND WEST OF A JACKSBORO TO LAMPASAS LINE IF WINDS ARE
STRONGER THAN FORECAST THIS AFTERNOON. LEVEL OF CONFIDENCE IN
HIGH FIRE DANGER IS HIGH. LEVEL OF CONFIDENCE IN EXTREME FIRE
WEATHER DANGER IS LOW.
WITH REGARDS TO THE STRONG WINDS BEHIND A COLD FRONT TONIGHT.
NORTH WINDS OF 25 TO 30 MPH...GUSTING TO 40 TO 45 MPH AT TIMES ARE
EXPECTED BEHIND THE COLD FRONT THROUGH SUNRISE. WINDS WILL BEGIN
TO DIMINISH IN INTENSITY FROM SUNRISE TO NOON ON WEDNESDAY. THE
LEVEL OF CONFIDENCE IN THESE STRONG WINDS IS HIGH...THEREFORE A
WIND ADVISORY WILL BE ISSUED FOR THE ENTIRE CWA FROM 10 PM THIS
EVENING TO NOON ON WEDNESDAY.
A FULL DISCUSSION INCLUDING REASONING AND THE REMAINDER OF THE
FORECAST WILL BE ISSUED LATER THIS MORNING.
CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 85 42 57 36 62 / 5 0 0 0 0
WACO, TX 82 41 58 33 60 / 5 0 0 0 0
PARIS, TX 80 41 54 32 61 / 0 0 0 0 0
DENTON, TX 85 39 57 31 63 / 5 0 0 0 0
MCKINNEY, TX 83 39 56 31 63 / 5 0 0 0 0
DALLAS, TX 84 43 57 38 62 / 5 0 0 0 0
TERRELL, TX 81 42 57 33 60 / 5 0 0 0 0
CORSICANA, TX 81 44 57 35 60 / 5 0 0 0 0
TEMPLE, TX 82 42 59 33 60 / 5 0 0 0 0
MINERAL WELLS, TX 88 38 56 33 62 / 0 0 0 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 10 PM THIS EVENING TO 1 PM CDT WEDNESDAY FOR
TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175.
&&
$$
/75
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1030 AM CDT TUE MAR 11 2014
.FIRE WEATHER...
BIG CONCERN THIS AFTERNOON IS ON FIRE WEATHER POTENTIAL. DUE TO
SOUTHWEST WINDS BEHIND A SURFACE TROUGH, OVERNIGHT RELATIVE HUMIDITY
RECOVERIES WERE VERY POOR FOR LOCATIONS ON THE CAPROCK WITH RELATIVE
HUMIDITY VALUES ONLY CLIMBING UP TO 35%. SEVERAL LOCATIONS EVEN
STAYED BELOW 30% ALL NIGHT. RECOVERIES WERE SLIGHTLY HIGHER AHEAD OF
THE SURFACE TROUGH ACROSS THE EASTERN PANHANDLES WHERE RELATIVE
HUMIDITY VALUES RANGED BETWEEN 50 AND 80%. WHAT THIS ESSENTIALLY
MEANS IS THAT FINE FUEL MOISTURE NEVER HAD A CHANCE TO MOISTEN AT ALL
FOR MOST LOCATIONS OVERNIGHT. RELATIVE HUMIDITY VALUES WILL CONTINUE
TO REMAIN VERY LOW FOR MUCH OF THE DAY UNTIL A COLD FRONT PASSES
THROUGH LATER TODAY. SPEAKING OF THE COLD FRONT, IT CURRENTLY
STRETCHES FROM NEAR HILL CITY, KS TO GARDEN CITY, KS TO SPRINGFIELD,
CO. THIS FRONT WILL ENTER OUR FORECAST AREA AFTER 11 AM, AND MOVE
SOUTHWARD THROUGH THE AFTERNOON.
APPROXIMATE COLD FRONT TIMING:
GUYMON: 1 PM
DALHART AND PERRYTON: 1-2 PM
DUMAS, BORGER, AND PAMPA: 3-4 PM
AMARILLO: 4-5 PM
SHAMROCK: 5-6 PM
HEREFORD: 6-7 PM
ONE OF THE BIGGEST QUESTION MARKS IS HOW STRONG WINDS WILL BE THIS
AFTERNOON AHEAD OF THE FRONT. RAW RUC AND NAM SOUNDINGS SUGGEST
MARGINAL WINDS FOR RED FLAG CONDITIONS IN OUR AREA. HOWEVER, PREFER
THE HIGHER MET AND MAV WINDS (WHICH IS CURRENTLY IN THE FORECAST) AS
MOS GUIDANCE TENDS TO DO RELATIVELY WELL ON THESE DOWNSLOPE WIND
DAYS. WILL LEAVE THE RED FLAG WARNING IN TACT, BUT OUR HIGHEST
CONFIDENCE FOR SEEING CRITICAL FIRE WEATHER CONDITIONS WILL BE SOUTH
OF A CLAYTON TO CANADIAN LINE.
THE ROLLER COASTER RIDE OF FUEL MOISTURE OVER THE LAST MONTH IS
CLEARLY SEEN IN TEXAS FOREST SERVICE ENERGY RELEASE COMPONENT (ERC)
DATA. AFTER LAST WEEK`S MOISTURE, WE HAVE QUICKLY DRIED OUT AGAIN. IN
FACT, FORECAST ERC VALUES TODAY ARE 67 AT BOOTLEG, 62 AT CEDAR, AND
60 AT WHEELER. THESE VALUES ARE GETTING VERY CLOSE TO THE 90%
PERCENTILE, AT WHICH LOCAL RESEARCH SUGGESTS SIGNIFICANT FIRE
POTENTIAL BECOMES AN INCREASING CONCERN. WITH THESE DRYING FUELS AND
A LITTLE MORE FAVORABLE FIRE WEATHER CONDITIONS, IT`S NOT A BIG
SURPRISE THAT WE SAW A SLIGHT UPTICK IN INITIAL ATTACK ACTIVITY
YESTERDAY. TFS SIGNIFICANT FIRE POTENTIAL MATRICES SHOW A MODERATE TO
NEAR HIGH POTENTIAL FOR SIGNIFICANT FIRE TODAY, ESPECIALLY ACROSS THE
FAR SOUTHWESTERN TEXAS PANHANDLE. THE AXIS OF A BROAD 850 MB THERMAL
RIDGE WILL STRETCH FROM NORTHEASTERN NEW MEXICO INTO THE SOUTHWESTERN
TEXAS PANHANDLE INTO THE SOUTH PLAINS. THE ALIGNMENT OF THE STRONGEST
LOW-/MID-LEVEL WINDS WILL GENERALLY OCCUR ALONG AND SOUTH OF THIS
AXIS. IT IS ALSO IN THESE LOCATIONS THAT TEMPERATURES WILL BE 5 TO 15
DEGREES ABOVE NORMAL, WHICH ALSO SUPPORTS HIGHER FIRE DANGER PER
LOCAL RESEARCH. THEREFORE, BASED ON FUELS AND WEATHER, THE HIGHEST
PROBABILITIES (AND THEY ARE STILL ON THE LOW SIDE) OF SIGNIFICANT
FIRE WEATHER POTENTIAL WILL REMAIN SOUTH AND WEST OF A HEREFORD TO
HAPPY LINE. DESPITE THIS, FIRE OFFICIALS AND EMERGENCY MANAGERS
SHOULD REMAIN ON HEIGHTENED ALERT, ESPECIALLY CONSIDERING THAT WINDS
WILL SHIFT FROM THE NORTHWEST TO THE NORTH AND INCREASE SUBSTANTIALLY
(GUSTS UP TO 60 MPH) BEHIND THE COLD FRONT LATER THIS AFTERNOON AND
EVENING. THIS WILL BE OF UTMOST IMPORTANCE IN THE EVENT OF ANY FIRE
STARTS OR ONGOING FIRES BEFORE THEN!
JACKSON
&&
.PREV DISCUSSION... /ISSUED 641 AM CDT TUE MAR 11 2014/
AVIATION...
12Z TAFS...WEST WINDS INITIALLY THIS MORNING WILL VEER TO THE
NORTHWEST BY MID TO LATE MORNING AND INCREASE TO 20-25 KTS WITH GUSTS
OF 30-35 KTS. A COLD FRONT WILL WORK SOUTH THROUGH THE AREA THIS
AFTERNOON...WITH WINDS TURNING TO THE NORTH BEHIND THE FRONT AND
INCREASING TO NEAR 35 KTS WITH GUSTS TO AROUND 50 KTS POSSIBLE. SOME
VSBY REDUCTIONS WILL BE POSSIBLE FROM BLDU BEHIND THE FRONT THIS
AFTERNOON AND EVENING. WINDS WILL DECREASE FROM NORTH TO SOUTH LATE
THIS EVENING AND OVERNIGHT. OUTSIDE OF ANY BLDU...VFR CONDITIONS ARE
EXPECTED. AN AVIATION WEATHER WARNING IS IN EFFECT FOR KAMA FROM 22Z
TODAY THROUGH 06Z WEDNESDAY FOR THE STRONG WINDS.
KB
PREV DISCUSSION... /ISSUED 406 AM CDT TUE MAR 11 2014/
DISCUSSION...
UPPER LEVEL SHORT WAVE TROUGH OVER WYOMING NOW WILL ELONGATE AND
SPLIT AS IT DIVES SOUTH THROUGH COLORADO AND KANSAS TODAY. A
POWERFUL COLD FRONT WILL BLAST ITS WAY SOUTH ACROSS THE PANHANDLES
THIS AFTERNOON AND EVENING IN ASSOCIATION WITH THE PASSAGE OF THE
SHORT WAVE TROUGH. SURFACE PRESSURE GRADIENT IS VERY TIGHT BETWEEN
LOW PRESSURE OVER NORTH CENTRAL TEXAS AND HIGH PRESSURE OVER
WYOMING BY LATE THIS AFTERNOON AND EARLY THIS EVENING. THIS TIGHT
PRESSURE GRADIENT IS EXPECTED TO BRING NORTH WINDS OF 30 TO 40 MILES
AN HOUR ACROSS THE PANHANDLES WITH GUST TO AROUND 60 MILES AN HOUR
IN SOME SPOTS. HAVE GONE AHEAD AND TURNED THE HIGH WIND WATCH INTO
A HIGH WIND WARNING FOR MUCH OF THE CWA. ONLY THE FAR EAST CENTRAL
AND SOUTHEAST TEXAS PANHANDLE WILL BE IN A WIND ADVISORY. BLOWING
DUST MAY ALSO REDUCE VISIBILITIES TO ONE MILE OR LESS AT TIMES. RED
FLAG WARNING CRITERIA IS ALSO EXPECTED TO BE MET ACROSS THE CWA
TODAY AS RELATIVE HUMIDITY VALUES DROP TO 15 PERCENT OR BELOW AHEAD
AND JUST BEHIND THE COLD FRONT. THE WIND SHIFT AND SUDDEN INCREASE
IN THE WIND WILL ALSO CAUSE UNPREDICTABLE FIRE BEHAVIOR SHOULD A
FIRE START.
WINDS WILL SLOWLY DECREASE AFTER MIDNIGHT AND SHOULD BE BELOW 20 MPH
BY MID MORNING ON WEDNESDAY.
THE MODELS STILL WANT TO PAINT SOME VERY LIGHT QPF...MAINLY ACROSS
THE NORTHERN CWA...THURSDAY NIGHT INTO FRIDAY IN ASSOCIATION WITH
THE SECOND SHORT WAVE TROUGH APPROACHING FROM THE WEST. FOR NOW
WILL LEAVE THE FORECAST DRY AS IT LOOKS LIKE MOISTURE WILL BE
LACKING.
THE NEXT SYSTEM TO AFFECT THE PANHANDLES WILL ARRIVE BY THE SECOND
HALF OF THE WEEKEND. THIS SYSTEM SLIDES SOUTHEAST ON THE EAST SIDE
OF A WEST COAST RIDGE AND IT INTENSIFIES AS IT MOVES INTO THE
SOUTHERN HIGH PLAINS. AGAIN...THE MODELS WANT CHANGE THEIR TUNE
SINCE IT IS A NEW DAY. THEREFORE...WILL NOT INSERT ANY PRECIP FOR
LATE NEXT WEEKEND AT THIS TIME.
FIRE WEATHER...
CRITICAL FIRE WEATHER CONDITIONS WILL BE FOUND ACROSS THE
PANHANDLES TODAY AND THIS EVENING. LOWEST AFTERNOON RELATIVE
HUMIDITY VALUES WILL GET DOWN INTO THE 5 TO 15 PERCENT RANGE
ACROSS MUCH OF THE PANHANDLES. RELATIVE HUMIDITY VALUES WILL
START TO RECOVER SOME BEHIND A COLD ACROSS THE OKLAHOMA
PANHANDLE AND THE NORTHERN TEXAS PANHANDLE BY MID AFTERNOON...
BUT WINDS WILL BE INCREASING BEHIND THE COLD FRONT SO ANY
ONGOING FIRES COULD HAVE ERRATIC BEHAVIOR DUE TO THE SHIFTING
WINDS WITH THE FRONT.
WINDS WILL DECREASE SLOWLY AFTER MIDNIGHT TONIGHT AND THEY
WILL BE BELOW 15 MPH BY AROUND MID MORNING ON WEDNESDAY.
ELEVATED FIRE WEATHER CONDITIONS WILL BE POSSIBLE ACROSS THE
PANHANDLES AGAIN ON THURSDAY AS SOUTHWEST WINDS INCREASE AND
RELATIVE HUMIDITY VALUES DROP.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...HIGH WIND WARNING FROM 1 PM THIS AFTERNOON TO 1 AM CDT WEDNESDAY
FOR THE FOLLOWING ZONES: CARSON...DALLAM...DEAF SMITH...
GRAY...HANSFORD...HARTLEY...HUTCHINSON...LIPSCOMB...MOORE...
OCHILTREE...OLDHAM...POTTER...RANDALL...ROBERTS...SHERMAN.
RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES: ARMSTRONG...CARSON...COLLINGSWORTH...DALLAM...DEAF
SMITH...DONLEY...GRAY...HANSFORD...HARTLEY...HEMPHILL...
HUTCHINSON...LIPSCOMB...MOORE...OCHILTREE...OLDHAM...
POTTER...RANDALL...ROBERTS...SHERMAN...WHEELER.
WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 1 AM CDT WEDNESDAY FOR
THE FOLLOWING ZONES: ARMSTRONG...COLLINGSWORTH...DONLEY...
HEMPHILL...WHEELER.
OK...HIGH WIND WARNING FROM 1 PM THIS AFTERNOON TO 1 AM CDT WEDNESDAY
FOR THE FOLLOWING ZONES: BEAVER...CIMARRON...TEXAS.
RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
700 AM CDT TUE MAR 11 2014
.AVIATION...
GUSTY WEST TO NORTHWEST WINDS ARE EXPECTED FOR MOST OF THE DAY
TODAY. PATCHY BLDU MAY CAUSE LOCAL VSBY REDUCTIONS. THIS
EVENING...A STRONG COLD FRONT WILL QUICKLY PASS THROUGH THE AREA.
SUSTAINED WIND SPEEDS COULD APPROACH 30 KTS AT EITHER OR BOTH
TERMINALS AND REQUIRE AN AIRPORT WEATHER WARNING. ALSO...THERE
WILL LIKELY BE A PERIOD OF HIGHER DUST CONCENTRATIONS WHICH COULD
RESULT IN MVFR VSBYS AT KLBB. WINDS WILL SLOWLY DECREASE WEDNESDAY
MORNING AND THE DUST WILL SETTLE. VFR CONDITIONS ARE EXPECTED FOR
THE REMAINDER OF THE FORECAST.
&&
.PREV DISCUSSION... /ISSUED 403 AM CDT TUE MAR 11 2014/
SHORT TERM...
THE STAGE IS SET FOR A EARLY SPRING STRONG WIND/BLOWING DUST AND
FIRE WEATHER EVENT TODAY AND TONIGHT. 3 AM SAT IMAGERY AND UPPER-AIR
ANALYSIS SHOW A SHARP SHORTWAVE MOVING QUICKLY THROUGH THE
INTER-MOUNTAIN WEST. THIS WAVE WILL MOVE ROUGHLY EWD INTO THE
CENTRAL PLAINS TODAY...PLACING THE CWA ON THE SRN FLANK OF THE
MID-LVL JET MAX WITHIN THE BASE OF THE TROUGH. IN ADDITION...A WEAK
SFC TROUGH EXTENDING SWD FROM A LOW IN FAR NE COLO THROUGH THE WRN
PANHANDLES INTO ERN NM WILL DEEPEN AND MOVE EAST TODAY. TIGHTENING
THE SFC PRESSURE GRADIENT WHILE WINDS SWING AROUND TO THE WEST THEN
W-NW. FINALLY...A STRONG COLD FRONT IS MOVING INTO NRN COLO AND WRN
NE...THIS FRONT WILL BE THE MAIN DRIVER OF STRONG WINDS THIS
EVENING/TONIGHT...MORE ON THAT LATER.
WINDS ARE EXPECTED TO PICK UP PRETTY QUICKLY THIS MORNING...THE WEST
TEXAS SODAR AT REESE CENTER ALREADY SHOWS 30+ KTS AT 500 FT AGL.
WHILE WE DO HAVE SOME SHALLOW MOISTURE IN PLACE ACROSS THE ERN CWA
THIS MORNING...UNFORTUNATELY...THIS MOISTURE WILL BE SCOURED OUT
QUICKLY AND CRITICAL FIRE WEATHER CONDITIONS COULD DEVELOP BEFORE
NOON /SEE DISCUSSION BELOW/. IN GENERAL...WE EXPECT WINDS TO RISE
INTO THE 25 TO 35 MPH RANGE ACROSS THE AREA TODAY...SLIGHTLY
LOWER IN THE ROLLING PLAINS AND SLIGHTLY MORE ACROSS THE W-SW.
THESE WINDS WILL LIKELY REMAIN JUST BELOW ADVISORY LEVELS BUT
SHOULD BE SUFFICIENT TO LOFT SOME PATCHY BLOWING DUST. TEMPS WILL
BE QUITE WARM FOR MOST OF THE AREA...WITH HIGHS IN THE
80S...PERHAPS PUSHING 90F IN THE SRN ROLLING PLAINS...WHILE CAA
COMING IN FROM THE NW SHOULD KEEP TEMPS IN THE 70S ACROSS THE FAR
SW TX PANHANDLE AND WRN SPLNS.
LATE THIS AFTERNOON...ATTENTION WILL TURN TO THE COLD FRONT WHICH IS
EXPECTED TO BE BARRELING SOUTH THROUGH THE PANHANDLES. WHILE
GUIDANCE IS IN GOOD AGREEMENT THAT THE FRONT/S PROGRESS WILL BE
QUICKER IN THE EAST...LAGGING IN THE WEST...THERE IS STILL A FEW
HOURS OF DISAGREEMENT IN THE TIMING OF THE FRONT. WE ARE FAVORING
THE HIGH-RES GUIDANCE FROM THE RAP AND THE TTU-WRF...WHICH SHOWS THE
FRONT ENTERING CHILDRESS COUNTY AROUND 23 UTC...AND PARMER COUNTY
AROUND 00 UTC. BUT OF COURSE THE ACTUAL FROPA COULD VARY A COUPLE
HOURS EITHER WAY. AS NOTED PREVIOUSLY...MODELS ARE SHOWING VERY
IMPRESSIVE PRESSURE RISES BEHIND THE FRONT THIS EVENING. OBJECTIVE
GUIDANCE SUGGESTS THAT WIND SPEEDS COULD REACH HIGH WIND CRITERIA
/SUSTAINED SPEED OF AT LEAST 40 MPH AND/OR GUSTS IN EXCESS OF 57
MPH/ ACROSS THE NRN HALF OF THE FA. WE ARE A LITTLE SKEPTICAL THAT
WE WILL SEE SUSTAINED HIGH WINDS IN THE LOWER TERRAIN OF THE ROLLING
PLAINS...BUT WE ARE PLANNING ON EXTENDING THE HIGH WIND WATCH SOUTH
AND EAST ACROSS MUCH OF THE CAPROCK....WITH SOLID ADVISORY-LEVEL
WINDS EXPECTED ELSEWHERE.
SOMEWHAT INTERESTINGLY...THERE IS A PRONOUNCED WEAKNESS PROGGED IN
THE 800-700MB WIND FIELD ACROSS MUCH OF OUR AREA AROUND 0Z. THIS
SHOULD NOT HAVE MUCH OF AN IMPACT ON THE OVERALL FCST BUT DEPENDING
ON THE TIMING OF THE FRONT...IT COULD LEAD TO A SHORT-DURATION LULL
IN GUSTY WINDS BEFORE A BIG INCREASE WITH THE FROPA.
AS FOR BLOWING DUST...WE ARE LOOKING FOR A CONCENTRATION OF DIRT AND
REDUCTION IN VISIBILITY ALONG AND IMMEDIATELY IN THE WAKE OF THE
FRONT...BUT WE DON/T HAVE ANY STRONG INDICATIONS AT THIS TIME THAT
VISIBILITIES WILL DROP TO ADVISORY OR DUST STORM LEVELS. THIS IS
PARTLY DUE TO THE WIND DIRECTION AND OUR EXPECTATION THAT THE FRONT
WILL MOVE THROUGH AFTER PEAK MIXING. IF THE FRONT IS FASTER/STRONGER
THAN EXPECTED...THEN DENSE BLOWING DUST MAY BE A GREATER CONCERN.
LONG TERM...
AFTER THE ACTIVE SHORT TERM...THE EXTENDED FORECAST SEEMS RELATIVELY
BENIGN BY COMPARISON. GUSTY NORTHERLY WINDS EARLY WEDNESDAY WILL
GRADUALLY WEAKEN THROUGH THE DAY AS THE PRESSURE GRADIENT RELAXES
AND SURFACE RIDGING SETTLES SQUARELY OVER WEST TEXAS. IT WILL BE
CONSIDERABLY COOLER BEHIND THIS EVENINGS FROPA...WITH HIGHS ON
WEDNESDAY TOPPING OUT AROUND 10 DEGREES BELOW MID-MARCH AVERAGES.
SHORTWAVE RIDGING ALOFT WILL FOLLOW ON THURSDAY WHICH WHEN COUPLED
WITH RETURN FLOW ON THE BACK SIDE OF THE DEPARTING SURFACE RIDGE AND
RENEWED SURFACE TROUGHING IN THE LEE OF THE ROCKIES WILL MEAN BREEZY
SOUTHERLY WINDS WITH TEMPERATURES RECOVERING TO NEAR AVERAGE.
ATTENTION WILL THEN TURN WEST TO A CUTOFF UPPER LOW THAT WILL HANG
OUT OVER THE GREAT BASIN MID-WEEK. THIS UPPER LOW WILL GET KICKED
EASTWARD LATE WEEK AS JET ENERGY MOVES INTO THE PACIFIC NORTHWEST.
THERE REMAINS SOME TIMING DIFFERENCES...BUT WHAT IS LEFT OF THE
UPPER LOW WILL RACE ACROSS THE SOUTH PLAINS FRIDAY OR FRIDAY NIGHT.
UNFORTUNATELY...THIS SYSTEM WILL NOT HAVE MUCH IN THE WAY OF
LOW-LEVEL MOISTURE TO WORK WITH...BUT THE GFS AND ECMWF DO CONTINUE
TO PAINT POCKETS OF VERY LIGHT QPF SOMEWHERE IN OR NEAR THE CWA.
GIVEN THIS SIGNAL...WE WOULD NOT BE SURPRISED TO SEE A FEW SPRINKLES
OR LIGHT SHOWERS...BUT THE CHANCE OF MEASURABLE RAIN STILL APPEARS
LOW AND WE HAVE MAINTAINED POPS AROUND 10 PERCENT. THE TIMING
UNCERTAINTY WITH THE PASSING WAVE DOES ALSO CREATE LOWER CONFIDENCE
ON WHEN THE ASSOCIATED FROPA WILL OCCUR. A QUICKER SYSTEM/FRONT
COULD MEAN TEMPERATURES A LITTLE COOLER THAN WHAT IS CURRENTLY
DEPICTED IN THE FORECAST...THOUGH EITHER WAY THE SYSTEM WILL NOT
HAVE MUCH COOL AIR TO WORK WITH.
THE FIRST HALF OF THE WEEKEND WILL START OUT ON THE MILD SIDE...WITH
HIGHS EXPECTED TO TOP OUT IN THE 60S AND LOWER 70S. HOWEVER...A
SHORTWAVE TROUGH IS PROGGED TO DIVE SOUTH-SOUTHEASTWARD TOWARD THE
REGION SATURDAY NIGHT. AT A MINIMUM...THIS DISTURBANCE SHOULD HELP
DRIVE A DECENT COLD FRONT THROUGH...DROPPING TEMPERATURES BACK BELOW
AVERAGE FOR THE SECOND HALF OF THE WEEKEND. LESS CERTAIN IS EXACTLY
WHAT LONGITUDE THIS DISTURBANCE PASSES AND THUS WHETHER OR NOT IT
CAN BRING A WINDOW FOR PRECIPITATION CHANCES TO THE SOUTH PLAINS.
THE MOST RECENT ECMWF HAS TRENDED BACK FURTHER WEST AND
WETTER...WHILE THE GFS TRACK IS MORE EASTWARD WHICH WOULD LIKELY BE
DRY FOR THE SOUTH PLAINS. WE HAVE MAINTAINED SILENT POPS AROUND 10
PERCENT FOR NOW AND WILL WAIT TO MAKE A MOVE ONE WAY OR THE OTHER UNTIL
THE NWP CAN COME INTO BETTER AGREEMENT. REGARDLESS...WARMER AND
DRY WEATHER SHOULD KICK OFF EARLY NEXT WEEK AS THE UPPER TROUGH
DEPARTS AND SOUTHERLY TO SOUTHWESTERLY SURFACE FLOW REDEVELOPS.
FIRE WEATHER...
LATEST INDICATIONS ARE THAT CRITICAL FIRE WEATHER CONDITIONS WILL
DEVELOP ACROSS THE ENTIRE SOUTH PLAINS AREA TODAY AND WE WILL EXPAND
AND UPGRADE THE WATCH TO A RED FLAG WARNING FOR OUR WHOLE CWA.
DESPITE HIGH RH VALUES ACROSS THE EASTERN SOUTH PLAINS AND ROLLING
PLAINS EARLY THIS MORNING...VERY DRY AIR WILL SPREAD EAST RESULTING
IN RH VALUES DROPPING UNDER 15 PERCENT BY 10 AM FOR MANY AREAS...AND
INTO THE SINGLE DIGITS ACROSS THE ENTIRE AREA THIS AFTERNOON. WHILE
WIND SPEEDS MAY BE ON THE LOW END OF CRITERIA ACROSS THE ERN ROLLING
PLAINS...IT APPEARS THAT WIND SPEEDS AND RH VALUES WILL SUPPORT AN
EXTREMELY CRITICAL DANGER FOR MUCH OF THE SOUTHWEST AND SOUTHERN
SOUTH PLAINS. WINDS MAY RELAX FOR A PERIOD AROUND 6 TO 7 PM...BUT
THE PASSAGE OF A STRONG COLD FRONT IN THE EVENING WILL BRING AN
ABRUPT WIND SHIFT TO THE NORTH AND MUCH STRONGER WINDS SPEEDS.
ALTHOUGH COOLING TEMPS AND RISING RH VALUES WILL BEGIN TO REDUCE
THE FIRE DANGER...WE WILL KEEP THE RED FLAG WARNING GOING THROUGH
9 PM CDT DUE TO THIS STRONG FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 71 25 52 24 60 / 0 0 0 0 0
TULIA 76 28 54 25 63 / 0 0 0 0 0
PLAINVIEW 77 29 55 26 63 / 0 0 0 0 0
LEVELLAND 78 30 54 26 63 / 0 0 0 0 0
LUBBOCK 81 32 56 29 64 / 0 0 0 0 0
DENVER CITY 80 31 55 25 61 / 0 0 0 0 0
BROWNFIELD 81 33 56 26 63 / 0 0 0 0 0
CHILDRESS 83 34 58 31 65 / 0 0 0 0 0
SPUR 85 35 58 30 65 / 0 0 0 0 0
ASPERMONT 88 36 58 29 65 / 0 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 11 AM THIS MORNING TO 10 PM CDT THIS
EVENING FOR THE FOLLOWING ZONES: TXZ021>044.
WIND ADVISORY FROM 7 PM THIS EVENING TO 3 AM CDT WEDNESDAY FOR
THE FOLLOWING ZONES: TXZ021>044.
&&
$$
33/23
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
624 AM CDT TUE MAR 11 2014
.AVIATION...
MID CLOUD HAS DISSIPATED OVER METROPLEX AND I CAN NOW SEE THE
STRATUS. ONE PATCH OF IFR CLOUDS IS MOVING NORTH INTO THE
SOUTHERN METROPLEX...AND HAVE ADDED A TEMPO FOR IFR CEILINGS THIS
MORNING. WITH STRONG SOUTHWEST FLOW JUST ABOVE THE
INVERSION...FEEL THAT WITH A BIT OF SUN THIS MORNING STRATUS WILL
QUICKLY MIX OUT AND SKIES WILL REMAIN CLEAR REST OF THE TAF
PERIOD.
WACO IFR WILL BE MORE PERSISTENT AND TAKE A COUPLE OF MORE HOURS
TO DISSIPATE...THEN THEY WILL ALSO REMAIN VFR FOR THE REST OF THE
TAF PERIOD.
STRONG COLD FRONT STILL PROGGED IN AROUND 10 PM/03Z FOR
METROPLEX...AND IT IS MOVING FAST ENOUGH THAT WACO WILL SEE IT
DURING THE SAME HOUR. WINDS WILL INCREASE SIGNIFICANTLY AN HOUR
OR TWO AFTER FROPA...BUT FORTUNATELY THEY WILL BE FROM THE NORTH
NORTHWEST AND NOT TOTALLY CROSS TO THE RUNWAYS. WINDS WILL LIKELY
REMAIN STRONG THROUGH MORNING...AND SLOWLY DIMINISH WEDNESDAY
BECOMING LIGHT AFTER SUNSET. 84
&&
.UPDATE...
EARLY MORNING REGIONAL RADARS SHOWED SOME VERY LIGHT RAINFALL OVER
CENTRAL TEXAS...EXTENDING AS FAR NORTH AS A HILLSBORO TO ATHENS
LINE. THESE RAIN SHOWERS WERE ORIENTED ON THE NORTHERN PERIPHERY
OF A VORTICITY LOBE ASSOCIATED WITH AN UPPER LOW...ROUGHLY
CENTERED OVER AUSTIN ACCORDING TO 08Z WATER VAPOR SATELLITE
IMAGERY. 08Z SURFACE ANALYSIS SHOWED MILD TEMPERATURES ACROSS
NORTH AND CENTRAL TEXAS WITH MOST LOCATIONS HOLDING UP IN THE MID
TO UPPER 50S. 08Z OBJECTIVE ANALYSIS SHOWED RELATIVELY STRONG LEE
SIDE CYCLOGENESIS OVER THE SOUTHERN HIGH PLAINS WITH 3 HR PRESSURE
FALLS OF AROUND 4 MB NEAR AN ELONGATED AREA OF LOW PRESSURE OF 997
MB OVER THE OK AND TX PANHANDLES.
TODAY...THE PREVIOUS QUICK AFD WAS APPENDED BELOW. IN GENERAL OVER
THE NEXT 24 TO 36 HRS THE REGION IS EXPECTED TO BE AFFECTED BY A
DYNAMIC LOW PRESSURE SYSTEM WHICH WILL LEAD TO FIRE WEATHER DANGER
AND STRONG WIND CONCERNS FOR NORTH AND CENTRAL TEXAS. THE PRIMARY
UPPER LEVEL FEATURE DRIVING THESE CONDITIONS IS A STRONG SHORTWAVE
TROUGH OBSERVED OVER UTAH...MOVING EAST-SOUTHEAST PER WATER VAPOR
SATELLITE IMAGERY. 00Z UPPER AIR ANALYSIS OBSERVED A STRONG JET
STREAK IN EXCESS OF 100 KTS AT THE 250 MB LEVEL AT THE BASE OF
THIS TROUGH. THIS JET STREAK WAS LIKELY LOCATED OVER THE CENTRAL
AND SOUTHERN CONUS ROCKIES EARLY THIS MORNING...AIDING IN THE
STRONG LEE SIDE SURFACE CYCLOGENESIS OBSERVED ACROSS THE OK AND TX
PANHANDLES.
THE STRONG UPPER LEVEL TROUGH IS EXPECTED TO MOVE EAST OVER THE
CENTRAL PLAINS TODAY...DRIVING THE SURFACE CYCLONE EAST-SOUTHEAST
TOWARDS NORTH TX THIS AFTERNOON. OUT AHEAD OF THE FRONT...WINDS
ARE EXPECTED TO BECOME BREEZY AND SOUTH-SOUTHWESTERLY AT 15 TO 20
MPH. ALL GUIDANCE INDICATES AN H850 THERMAL RIDGE ORIENTED ALONG
AND SOUTH OF THE SURFACE CYCLONE...BUT THE STRENGTH OF THE THERMAL
RIDGE VARIES MODEL TO MODEL. HIGHER RESOLUTION MODEL GUIDANCE
GENERALLY FAVORS A STRONGER THERMAL RIDGE...SO THE HIGH
TEMPERATURE FORECAST FOR TODAY WAS BASED ON THE HIGH END OF THE
SPECTRUM OF AVAILABLE GUIDANCE. WENT AHEAD WITH HIGHS JUST ABOVE
90 DEGREES NEAR BRECKENRIDGE AND GRAHAM...AND IN THE MID TO UPPER
80S FOR MOST LOCATIONS ALONG AND WEST OF THE INTERSTATE 35
CORRIDOR. TO THE EAST...HIGHS WILL GENERALLY TOP OUT IN THE LOWER
80S TODAY...A BIT FARTHER REMOVED FROM THE DRIEST AIR AND STRONG
THERMAL RIDGE NEAR THE SURFACE LOW.
LOOKING AT FIRE WEATHER CONCERNS...ASSUMING HIGHS TOP OUT IN THE
MID 80S TO JUST ABOVE 90 DEGREES WEST OF INTERSTATE 35 AS
EXPECTED...GRASSY/FINE FUEL TEMPERATURES WILL GET QUITE WARM THIS
AFTERNOON. WINDS OF 15 TO 20 MPH COMBINED WITH AFTERNOON RELATIVE
HUMIDITY VALUES BELOW 30 PERCENT SUPPORT AT LEAST A HIGH FIRE
WEATHER DANGER ALONG AND WEST OF THE INTERSTATE 35 CORRIDOR...AND
A GRASS FIRE DANGER STATEMENT HAS BEEN ISSUED FOR THESE LOCATIONS
AS A RESULT. CRITICAL TO EXTREME FIRE WEATHER DANGER IS POSSIBLE
THIS AFTERNOON...BUT DEPENDENT UP ON THE STRENGTH OF WINDS AND
POSITION OF THE DRYLINE.
MOST MODEL GUIDANCE KEEPS WINDS BELOW RED FLAG WARNING CRITERIA
THIS AFTERNOON OVER THE WESTERN CWA. THIS IS PARTLY BECAUSE MODELS
HAVE A PART OF THE ELONGATED SURFACE LOW PRESSURE LOCATED VERY
NEAR WICHITA FALLS...GENERALLY REDUCING THE PRESSURE GRADIENT
FORCE THAT WOULD OTHERWISE ACCELERATE WINDS THE ADDITIONAL 5 TO 10
MPH NECESSARY TO REACH RED FLAG WARNING CRITERIA. HOWEVER IF THE
SURFACE LOW IS A BIT FARTHER NORTH...LIKE THE RAP AND HRRR
ADVERTISED AT THE TIME OF THIS DISCUSSION...EXTREME FIRE WEATHER
DANGER MAY BE REALIZED THIS AFTERNOON AND A RED FLAG WARNING MAY
NEED TO BE ISSUED.
THE HRRR IN PARTICULAR SHOWED A STRONG DRYLINE PUNCH INTO THE
WESTERN CWA...WITH THE DRYLINE PUSHING AS FAR EAST AS A JACKSBORO
TO LAMPASAS LINE BY 21Z. THE HRRR INCREASES WESTERLY WINDS AT THE
SURFACE TO 20 TO 25 KTS...OR STRONG ENOUGH FOR CRITICAL/EXTREME
FIRE DANGER WITH RELATIVE HUMIDITY VALUES CRASHING INTO THE SINGLE
DIGITS WEST OF THE DRYLINE. IF THESE HRRR CONDITIONS ARE
REALIZED...A RED FLAG WARNING WOULD CERTAINLY BE WARRANTED BECAUSE
ANY GRASS-FIRE IGNITED WOULD BE VERY DIFFICULT...IF NOT
IMPOSSIBLE...TO CONTROL. THIS IS DEFINITELY A WORST CASE
SCENARIO...AND IS NOT SUPPORTED BY ANY OTHER GUIDANCE AT THIS
TIME. REGARDLESS...THIS BEARS WATCHING CLOSELY THROUGHOUT THE DAY
AS THE HRRR WAS ALSO THE MOST RECENT GUIDANCE AVAILABLE AT THE
TIME OF THIS DISCUSSION.
THIS EVENING AND OVERNIGHT...THE SURFACE CYCLONE WILL CONTINUE
EAST THIS EVENING...WITH A STRONG COLD FRONT DROPPING SOUTH ACROSS
THE REGION IN ITS WAKE. WHILE MODELS DO NOT AGREE ON THE EXACT
TIMING OF THE FRONT YET...ALL MODELS AGREE THAT THE FRONT WILL BE
VERY FAST MOVING ONCE IT CROSSES THE RED RIVER THIS EVENING. WINDS
WILL SHIFT QUICKLY AROUND TO THE NORTH BEHIND THE FRONT...AND PICK
UP TO AT LEAST 20 MPH GUSTING ABOVE 30 MPH JUST BEHIND ITS LEADING
EDGE. WINDS ARE EXPECTED TO INCREASE IN INTENSITY BY ABOUT 10 MPH
OR SO AN HOUR OR TWO BEHIND THE INITIAL FRONTAL PASSAGE. SUSTAINED
WINDS OF 30 MPH...GUSTING TO 45 MPH AT TIMES ARE EXPECTED AT PEAK
INTENSITY OVERNIGHT.
CONFIDENCE IN STRONG WINDS IS VERY HIGH AT THIS TIME AS ALL MODEL
GUIDANCE SHOWS AT LEAST A 50 KT JET AT THE 850 MB LEVEL OVER THE
CWA BEHIND THE FRONT TONIGHT. HIGHER RESOLUTION GUIDANCE INDICATES
55 TO 60 KT JET FROM 09 TO 12Z OVER THE CWA WELL BEHIND THE FRONT.
WENT AHEAD WITH A WIND ADVISORY FOR THE ENTIRE CWA FROM 10 PM THIS
EVENING THROUGH 1 PM WEDNESDAY AS THIS APPEARED TO BE THE BEST
WINDOW FOR NORTH WINDS EXCEEDING 25 MPH OR GUSTING ABOVE 40 MPH.
THE START OR END TIMES OF THIS ADVISORY WILL LIKELY BE ADJUSTED BY
LATER SHIFTS AS THE EXACT TIMING OF THE FRONT IS BETTER RESOLVED.
WEDNESDAY AND THURSDAY...WEDNESDAY WILL START OFF WITH THE WIND
ADVISORY STILL IN EFFECT AS NORTH WINDS HOLD UP AROUND 25 MPH
GUSTING TO 40 MPH JUST AFTER SUNRISE...AND THEN SLOWLY DIMINISH
TO AROUND 20 MPH JUST AFTER NOON. WEDNESDAY WILL BE MUCH COOLER
WITH HIGHS GENERALLY HOLDING IN THE MID 50S WITH STRONG COLD AIR
ADVECTION IN PLACE. SKIES ARE EXPECTED TO STAY MOSTLY SUNNY ON
WEDNESDAY...WHICH WILL AT LEAST TAKE SOME OF THE BITE OUT OF THE
COOL...BREEZY AIR. HOWEVER...WINDS ARE EXPECTED TO BECOME LIGHT
AND VARIABLE BY EARLY THURSDAY MORNING...UNDER MOSTLY CLEAR SKIES.
THIS WILL BRING MANY LOCATIONS DOWN BELOW FREEZING WEDNESDAY
NIGHT...WITH THE EXCEPTION OF URBANIZED AREAS WHICH WILL STAY
WARMER DUE TO THE ABSORPTION OF SUNSHINE THROUGHOUT THE DAY ON
WEDNESDAY. LIGHT WINDS WILL BECOME SOUTHERLY ON THURSDAY AS
TEMPERATURES WARM INTO THE 60S.
FRIDAY AND FRIDAY NIGHT...MODELS CONTINUE TO INDICATE A RELATIVELY
COMPACT BUT STRONG SHORTWAVE TROUGH WILL MOVE OVER NORTH TEXAS
FRIDAY AFTERNOON OR EVENING. BOTH THE GFS AND ECMWF WERE
ADVERTISING SOME LIGHT QPF AMOUNTS ASSOCIATED WITH THIS TROUGH
WHICH IS DIFFERENT FROM PREVIOUS DAYS. THINK THE QPF
AMOUNTS...ALTHOUGH LIGHT...ARE STILL OPTIMISTIC BECAUSE TONIGHT`S
FRONT IS EXPECTED TO PLOW SOUTH ALL THE WAY ACROSS THE WESTERN
GULF OF MEXICO...EFFECTIVELY STUNTING OUR PRIMARY MECHANISM TO
RECHARGE THE LOWER TROPOSPHERE WITH WATER VAPOR.
THE SHORTWAVE TROUGH ITSELF IS EXPECTED TO ORIGINATE FROM THE
TROUGH THAT SENDS THE STRONG FRONT SOUTH ACROSS THE REGION
TONIGHT. IT IS EXPECTED TO BREAK OFF THE MAIN TROUGH AND REMAIN
QUASI-STEADY OVER THE SOUTHWESTERN CONUS FOR A COUPLE OF DAYS
BEFORE MOVING EAST WITH THE NEXT NORTHERN STREAM SHORTWAVE TROUGH
THURSDAY NIGHT INTO FRIDAY. THE ONLY REASON THIS MATTERS AT ALL IS
BECAUSE IT IS NOT LIKELY TO BE ASSOCIATED WITH A PLUME OF SOUTHERN
PACIFIC MOISTURE...SO THE ORIGIN OF THE RAPID MOISTENING OF THE
GFS AND ECMWF OUT AHEAD OF THE TROUGH IS A BIT OF A MYSTERY AT
THIS TIME. GRANTED...LIFT ASSOCIATED WITH THE TROUGH IS EXPECTED
TO BE STRONG...SO DYNAMIC LIFT...COOLING AND SATURATION FROM THE
BOTTOM UP...IS POSSIBLE.
WENT AHEAD WITH SOME 20 POPS FRIDAY AFTERNOON AND EVENING ACROSS
THE FAR EASTERN CWA DUE TO UNCERTAINTY REGARDING THE SOURCE REGION
OF MOISTURE FOR THE GFS AND ECMWF POP/QPF FORECAST. IF MOISTURE IS
JUST BEING UNDERESTIMATED IN GENERAL...POPS AND QPF MAY HAVE TO BE
BUMPED WEST IN LATER FORECASTS.
NEXT WEEKEND...A STRONG UPPER LEVEL TROUGH IS EXPECTED TO MOVE
FROM THE NORTHWEST CONUS SOUTHEAST TOWARDS THE SOUTHERN PLAINS
DURING THIS TIME. THE GFS CONTINUES TO BRING THIS TROUGH OVER
NORTH TX...OR JUST OFF TO THE SOUTHWEST. IN GENERAL...RESULTING
IN A WETTER FORECAST THAN IF THE TROUGH REMAINS TO THE NORTH OF
THE CWA. YESTERDAY THE OPERATIONAL GFS HAD ALMOST NO ENSEMBLE
SUPPORT FOR THIS SOLUTION...SO IT WAS LARGELY DISCOUNTED. HOWEVER
TODAY...ABOUT HALF OF THE GFS ENSEMBLE MEMBERS AGREE WITH THIS
SOLUTION...AND THE OPERATIONAL CANADIAN AND ECMWF HAVE SORT OF
COME ON BOARD AS WELL. /SORT OF/ IS USED BECAUSE THERE ARE SOME
FAIRLY LARGE TIMING AND STRENGTH DISCREPANCIES BETWEEN THESE
MODELS.
HOWEVER THE FORECAST TRACK OF THE UPPER TROUGH SEEMS TO BE THE
MAIN DIFFERENCE DICTATING A WET VERSUS DRY FORECAST...SO IT IS
GOOD TO SEE MODELS TRENDING TOWARDS A MORE SOUTHERLY TRACK AT THIS
TIME. QPF AMOUNTS ARE NOT VERY HIGH IN ANY OF THESE
SOLUTIONS...MOSTLY BECAUSE IN ALL SOLUTIONS THE UPPER TROUGH IS
POSITIVELY TILTED UNTIL IT MOVES EAST OF THE SOUTH PLAINS.
BUT...BEGGARS CANT BE CHOOSERS...AND WE REALLY NEED SOME RAIN...SO
WILL CONTINUE TO WATCH THE EVOLUTION OF THIS WEEKENDS TROUGH
CLOSELY IN THE COMING DAYS AND HOPE FOR THE BEST.
CAVANAUGH
&&
.PREV DISCUSSION... /ISSUED 328 AM CDT TUE MAR 11 2014/
IN THE SHORT TERM FORECAST THERE ARE TWO PRIMARY CONCERNS:
1. FIRE WEATHER DANGER WEST OF INTERSTATE 35 THIS AFTERNOON.
2. STRONG WINDS BEHIND A COLD FRONT LATE THIS EVENING THROUGH
WEDNESDAY MORNING.
WITH REGARDS TO FIRE WEATHER DANGER: WILL HOLD OFF ON ISSUING A
RED FLAG WARNING AT THIS TIME. FIRE WEATHER DANGER WILL BE HIGH TO
VERY HIGH WEST OF INTERSTATE 35 THIS AFTERNOON. CRITICAL OR
EXTREME FIRE WEATHER DANGER IS POSSIBLE FOR LOCATIONS GENERALLY
ALONG AND WEST OF A JACKSBORO TO LAMPASAS LINE IF WINDS ARE
STRONGER THAN FORECAST THIS AFTERNOON. LEVEL OF CONFIDENCE IN
HIGH FIRE DANGER IS HIGH. LEVEL OF CONFIDENCE IN EXTREME FIRE
WEATHER DANGER IS LOW.
WITH REGARDS TO THE STRONG WINDS BEHIND A COLD FRONT TONIGHT.
NORTH WINDS OF 25 TO 30 MPH...GUSTING TO 40 TO 45 MPH AT TIMES ARE
EXPECTED BEHIND THE COLD FRONT THROUGH SUNRISE. WINDS WILL BEGIN
TO DIMINISH IN INTENSITY FROM SUNRISE TO NOON ON WEDNESDAY. THE
LEVEL OF CONFIDENCE IN THESE STRONG WINDS IS HIGH...THEREFORE A
WIND ADVISORY WILL BE ISSUED FOR THE ENTIRE CWA FROM 10 PM THIS
EVENING TO NOON ON WEDNESDAY.
A FULL DISCUSSION INCLUDING REASONING AND THE REMAINDER OF THE
FORECAST WILL BE ISSUED LATER THIS MORNING.
CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 85 42 57 36 62 / 5 0 0 0 0
WACO, TX 82 41 58 33 60 / 5 0 0 0 0
PARIS, TX 80 41 54 32 61 / 0 0 0 0 0
DENTON, TX 85 39 57 31 63 / 5 0 0 0 0
MCKINNEY, TX 83 39 56 31 63 / 5 0 0 0 0
DALLAS, TX 84 43 57 38 62 / 5 0 0 0 0
TERRELL, TX 81 42 57 33 60 / 5 0 0 0 0
CORSICANA, TX 81 44 57 35 60 / 10 0 0 0 0
TEMPLE, TX 82 42 59 33 60 / 5 0 0 0 0
MINERAL WELLS, TX 88 38 56 33 62 / 0 0 0 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 10 PM THIS EVENING TO 1 PM CDT WEDNESDAY FOR
TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175.
&&
$$
/
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
457 AM CDT TUE MAR 11 2014
.UPDATE...
EARLY MORNING REGIONAL RADARS SHOWED SOME VERY LIGHT RAINFALL OVER
CENTRAL TEXAS...EXTENDING AS FAR NORTH AS A HILLSBORO TO ATHENS
LINE. THESE RAIN SHOWERS WERE ORIENTED ON THE NORTHERN PERIPHERY
OF A VORTICITY LOBE ASSOCIATED WITH AN UPPER LOW...ROUGHLY
CENTERED OVER AUSTIN ACCORDING TO 08Z WATER VAPOR SATELLITE
IMAGERY. 08Z SURFACE ANALYSIS SHOWED MILD TEMPERATURES ACROSS
NORTH AND CENTRAL TEXAS WITH MOST LOCATIONS HOLDING UP IN THE MID
TO UPPER 50S. 08Z OBJECTIVE ANALYSIS SHOWED RELATIVELY STRONG LEE
SIDE CYCLOGENESIS OVER THE SOUTHERN HIGH PLAINS WITH 3 HR PRESSURE
FALLS OF AROUND 4 MB NEAR AN ELONGATED AREA OF LOW PRESSURE OF 997
MB OVER THE OK AND TX PANHANDLES.
TODAY...THE PREVIOUS QUICK AFD WAS APPENDED BELOW. IN GENERAL OVER
THE NEXT 24 TO 36 HRS THE REGION IS EXPECTED TO BE AFFECTED BY A
DYNAMIC LOW PRESSURE SYSTEM WHICH WILL LEAD TO FIRE WEATHER DANGER
AND STRONG WIND CONCERNS FOR NORTH AND CENTRAL TEXAS. THE PRIMARY
UPPER LEVEL FEATURE DRIVING THESE CONDITIONS IS A STRONG SHORTWAVE
TROUGH OBSERVED OVER UTAH...MOVING EAST-SOUTHEAST PER WATER VAPOR
SATELLITE IMAGERY. 00Z UPPER AIR ANALYSIS OBSERVED A STRONG JET
STREAK IN EXCESS OF 100 KTS AT THE 250 MB LEVEL AT THE BASE OF
THIS TROUGH. THIS JET STREAK WAS LIKELY LOCATED OVER THE CENTRAL
AND SOUTHERN CONUS ROCKIES EARLY THIS MORNING...AIDING IN THE
STRONG LEE SIDE SURFACE CYCLOGENESIS OBSERVED ACROSS THE OK AND TX
PANHANDLES.
THE STRONG UPPER LEVEL TROUGH IS EXPECTED TO MOVE EAST OVER THE
CENTRAL PLAINS TODAY...DRIVING THE SURFACE CYCLONE EAST-SOUTHEAST
TOWARDS NORTH TX THIS AFTERNOON. OUT AHEAD OF THE FRONT...WINDS
ARE EXPECTED TO BECOME BREEZY AND SOUTH-SOUTHWESTERLY AT 15 TO 20
MPH. ALL GUIDANCE INDICATES AN H850 THERMAL RIDGE ORIENTED ALONG
AND SOUTH OF THE SURFACE CYCLONE...BUT THE STRENGTH OF THE THERMAL
RIDGE VARIES MODEL TO MODEL. HIGHER RESOLUTION MODEL GUIDANCE
GENERALLY FAVORS A STRONGER THERMAL RIDGE...SO THE HIGH
TEMPERATURE FORECAST FOR TODAY WAS BASED ON THE HIGH END OF THE
SPECTRUM OF AVAILABLE GUIDANCE. WENT AHEAD WITH HIGHS JUST ABOVE
90 DEGREES NEAR BRECKENRIDGE AND GRAHAM...AND IN THE MID TO UPPER
80S FOR MOST LOCATIONS ALONG AND WEST OF THE INTERSTATE 35
CORRIDOR. TO THE EAST...HIGHS WILL GENERALLY TOP OUT IN THE LOWER
80S TODAY...A BIT FARTHER REMOVED FROM THE DRIEST AIR AND STRONG
THERMAL RIDGE NEAR THE SURFACE LOW.
LOOKING AT FIRE WEATHER CONCERNS...ASSUMING HIGHS TOP OUT IN THE
MID 80S TO JUST ABOVE 90 DEGREES WEST OF INTERSTATE 35 AS
EXPECTED...GRASSY/FINE FUEL TEMPERATURES WILL GET QUITE WARM THIS
AFTERNOON. WINDS OF 15 TO 20 MPH COMBINED WITH AFTERNOON RELATIVE
HUMIDITY VALUES BELOW 30 PERCENT SUPPORT AT LEAST A HIGH FIRE
WEATHER DANGER ALONG AND WEST OF THE INTERSTATE 35 CORRIDOR...AND
A GRASS FIRE DANGER STATEMENT HAS BEEN ISSUED FOR THESE LOCATIONS
AS A RESULT. CRITICAL TO EXTREME FIRE WEATHER DANGER IS POSSIBLE
THIS AFTERNOON...BUT DEPENDENT UP ON THE STRENGTH OF WINDS AND
POSITION OF THE DRYLINE.
MOST MODEL GUIDANCE KEEPS WINDS BELOW RED FLAG WARNING CRITERIA
THIS AFTERNOON OVER THE WESTERN CWA. THIS IS PARTLY BECAUSE MODELS
HAVE A PART OF THE ELONGATED SURFACE LOW PRESSURE LOCATED VERY
NEAR WICHITA FALLS...GENERALLY REDUCING THE PRESSURE GRADIENT
FORCE THAT WOULD OTHERWISE ACCELERATE WINDS THE ADDITIONAL 5 TO 10
MPH NECESSARY TO REACH RED FLAG WARNING CRITERIA. HOWEVER IF THE
SURFACE LOW IS A BIT FARTHER NORTH...LIKE THE RAP AND HRRR
ADVERTISED AT THE TIME OF THIS DISCUSSION...EXTREME FIRE WEATHER
DANGER MAY BE REALIZED THIS AFTERNOON AND A RED FLAG WARNING MAY
NEED TO BE ISSUED.
THE HRRR IN PARTICULAR SHOWED A STRONG DRYLINE PUNCH INTO THE
WESTERN CWA...WITH THE DRYLINE PUSHING AS FAR EAST AS A JACKSBORO
TO LAMPASAS LINE BY 21Z. THE HRRR INCREASES WESTERLY WINDS AT THE
SURFACE TO 20 TO 25 KTS...OR STRONG ENOUGH FOR CRITICAL/EXTREME
FIRE DANGER WITH RELATIVE HUMIDITY VALUES CRASHING INTO THE SINGLE
DIGITS WEST OF THE DRYLINE. IF THESE HRRR CONDITIONS ARE
REALIZED...A RED FLAG WARNING WOULD CERTAINLY BE WARRANTED BECAUSE
ANY GRASS-FIRE IGNITED WOULD BE VERY DIFFICULT...IF NOT
IMPOSSIBLE...TO CONTROL. THIS IS DEFINITELY A WORST CASE
SCENARIO...AND IS NOT SUPPORTED BY ANY OTHER GUIDANCE AT THIS
TIME. REGARDLESS...THIS BEARS WATCHING CLOSELY THROUGHOUT THE DAY
AS THE HRRR WAS ALSO THE MOST RECENT GUIDANCE AVAILABLE AT THE
TIME OF THIS DISCUSSION.
THIS EVENING AND OVERNIGHT...THE SURFACE CYCLONE WILL CONTINUE
EAST THIS EVENING...WITH A STRONG COLD FRONT DROPPING SOUTH ACROSS
THE REGION IN ITS WAKE. WHILE MODELS DO NOT AGREE ON THE EXACT
TIMING OF THE FRONT YET...ALL MODELS AGREE THAT THE FRONT WILL BE
VERY FAST MOVING ONCE IT CROSSES THE RED RIVER THIS EVENING. WINDS
WILL SHIFT QUICKLY AROUND TO THE NORTH BEHIND THE FRONT...AND PICK
UP TO AT LEAST 20 MPH GUSTING ABOVE 30 MPH JUST BEHIND ITS LEADING
EDGE. WINDS ARE EXPECTED TO INCREASE IN INTENSITY BY ABOUT 10 MPH
OR SO AN HOUR OR TWO BEHIND THE INITIAL FRONTAL PASSAGE. SUSTAINED
WINDS OF 30 MPH...GUSTING TO 45 MPH AT TIMES ARE EXPECTED AT PEAK
INTENSITY OVERNIGHT.
CONFIDENCE IN STRONG WINDS IS VERY HIGH AT THIS TIME AS ALL MODEL
GUIDANCE SHOWS AT LEAST A 50 KT JET AT THE 850 MB LEVEL OVER THE
CWA BEHIND THE FRONT TONIGHT. HIGHER RESOLUTION GUIDANCE INDICATES
55 TO 60 KT JET FROM 09 TO 12Z OVER THE CWA WELL BEHIND THE FRONT.
WENT AHEAD WITH A WIND ADVISORY FOR THE ENTIRE CWA FROM 10 PM THIS
EVENING THROUGH 1 PM WEDNESDAY AS THIS APPEARED TO BE THE BEST
WINDOW FOR NORTH WINDS EXCEEDING 25 MPH OR GUSTING ABOVE 40 MPH.
THE START OR END TIMES OF THIS ADVISORY WILL LIKELY BE ADJUSTED BY
LATER SHIFTS AS THE EXACT TIMING OF THE FRONT IS BETTER RESOLVED.
WEDNESDAY AND THURSDAY...WEDNESDAY WILL START OFF WITH THE WIND
ADVISORY STILL IN EFFECT AS NORTH WINDS HOLD UP AROUND 25 MPH
GUSTING TO 40 MPH JUST AFTER SUNRISE...AND THEN SLOWLY DIMINISH
TO AROUND 20 MPH JUST AFTER NOON. WEDNESDAY WILL BE MUCH COOLER
WITH HIGHS GENERALLY HOLDING IN THE MID 50S WITH STRONG COLD AIR
ADVECTION IN PLACE. SKIES ARE EXPECTED TO STAY MOSTLY SUNNY ON
WEDNESDAY...WHICH WILL AT LEAST TAKE SOME OF THE BITE OUT OF THE
COOL...BREEZY AIR. HOWEVER...WINDS ARE EXPECTED TO BECOME LIGHT
AND VARIABLE BY EARLY THURSDAY MORNING...UNDER MOSTLY CLEAR SKIES.
THIS WILL BRING MANY LOCATIONS DOWN BELOW FREEZING WEDNESDAY
NIGHT...WITH THE EXCEPTION OF URBANIZED AREAS WHICH WILL STAY
WARMER DUE TO THE ABSORPTION OF SUNSHINE THROUGHOUT THE DAY ON
WEDNESDAY. LIGHT WINDS WILL BECOME SOUTHERLY ON THURSDAY AS
TEMPERATURES WARM INTO THE 60S.
FRIDAY AND FRIDAY NIGHT...MODELS CONTINUE TO INDICATE A RELATIVELY
COMPACT BUT STRONG SHORTWAVE TROUGH WILL MOVE OVER NORTH TEXAS
FRIDAY AFTERNOON OR EVENING. BOTH THE GFS AND ECMWF WERE
ADVERTISING SOME LIGHT QPF AMOUNTS ASSOCIATED WITH THIS TROUGH
WHICH IS DIFFERENT FROM PREVIOUS DAYS. THINK THE QPF
AMOUNTS...ALTHOUGH LIGHT...ARE STILL OPTIMISTIC BECAUSE TONIGHT`S
FRONT IS EXPECTED TO PLOW SOUTH ALL THE WAY ACROSS THE WESTERN
GULF OF MEXICO...EFFECTIVELY STUNTING OUR PRIMARY MECHANISM TO
RECHARGE THE LOWER TROPOSPHERE WITH WATER VAPOR.
THE SHORTWAVE TROUGH ITSELF IS EXPECTED TO ORIGINATE FROM THE
TROUGH THAT SENDS THE STRONG FRONT SOUTH ACROSS THE REGION
TONIGHT. IT IS EXPECTED TO BREAK OFF THE MAIN TROUGH AND REMAIN
QUASI-STEADY OVER THE SOUTHWESTERN CONUS FOR A COUPLE OF DAYS
BEFORE MOVING EAST WITH THE NEXT NORTHERN STREAM SHORTWAVE TROUGH
THURSDAY NIGHT INTO FRIDAY. THE ONLY REASON THIS MATTERS AT ALL IS
BECAUSE IT IS NOT LIKELY TO BE ASSOCIATED WITH A PLUME OF SOUTHERN
PACIFIC MOISTURE...SO THE ORIGIN OF THE RAPID MOISTENING OF THE
GFS AND ECMWF OUT AHEAD OF THE TROUGH IS A BIT OF A MYSTERY AT
THIS TIME. GRANTED...LIFT ASSOCIATED WITH THE TROUGH IS EXPECTED
TO BE STRONG...SO DYNAMIC LIFT...COOLING AND SATURATION FROM THE
BOTTOM UP...IS POSSIBLE.
WENT AHEAD WITH SOME 20 POPS FRIDAY AFTERNOON AND EVENING ACROSS
THE FAR EASTERN CWA DUE TO UNCERTAINTY REGARDING THE SOURCE REGION
OF MOISTURE FOR THE GFS AND ECMWF POP/QPF FORECAST. IF MOISTURE IS
JUST BEING UNDERESTIMATED IN GENERAL...POPS AND QPF MAY HAVE TO BE
BUMPED WEST IN LATER FORECASTS.
NEXT WEEKEND...A STRONG UPPER LEVEL TROUGH IS EXPECTED TO MOVE
FROM THE NORTHWEST CONUS SOUTHEAST TOWARDS THE SOUTHERN PLAINS
DURING THIS TIME. THE GFS CONTINUES TO BRING THIS TROUGH OVER
NORTH TX...OR JUST OFF TO THE SOUTHWEST. IN GENERAL...RESULTING
IN A WETTER FORECAST THAN IF THE TROUGH REMAINS TO THE NORTH OF
THE CWA. YESTERDAY THE OPERATIONAL GFS HAD ALMOST NO ENSEMBLE
SUPPORT FOR THIS SOLUTION...SO IT WAS LARGELY DISCOUNTED. HOWEVER
TODAY...ABOUT HALF OF THE GFS ENSEMBLE MEMBERS AGREE WITH THIS
SOLUTION...AND THE OPERATIONAL CANADIAN AND ECMWF HAVE SORT OF
COME ON BOARD AS WELL. /SORT OF/ IS USED BECAUSE THERE ARE SOME
FAIRLY LARGE TIMING AND STRENGTH DISCREPANCIES BETWEEN THESE
MODELS.
HOWEVER THE FORECAST TRACK OF THE UPPER TROUGH SEEMS TO BE THE
MAIN DIFFERENCE DICTATING A WET VERSUS DRY FORECAST...SO IT IS
GOOD TO SEE MODELS TRENDING TOWARDS A MORE SOUTHERLY TRACK AT THIS
TIME. QPF AMOUNTS ARE NOT VERY HIGH IN ANY OF THESE
SOLUTIONS...MOSTLY BECAUSE IN ALL SOLUTIONS THE UPPER TROUGH IS
POSITIVELY TILTED UNTIL IT MOVES EAST OF THE SOUTH PLAINS.
BUT...BEGGARS CANT BE CHOOSERS...AND WE REALLY NEED SOME RAIN...SO
WILL CONTINUE TO WATCH THE EVOLUTION OF THIS WEEKENDS TROUGH
CLOSELY IN THE COMING DAYS AND HOPE FOR THE BEST.
CAVANAUGH
&&
.PREV DISCUSSION... /ISSUED 328 AM CDT TUE MAR 11 2014/
IN THE SHORT TERM FORECAST THERE ARE TWO PRIMARY CONCERNS:
1. FIRE WEATHER DANGER WEST OF INTERSTATE 35 THIS AFTERNOON.
2. STRONG WINDS BEHIND A COLD FRONT LATE THIS EVENING THROUGH
WEDNESDAY MORNING.
WITH REGARDS TO FIRE WEATHER DANGER: WILL HOLD OFF ON ISSUING A
RED FLAG WARNING AT THIS TIME. FIRE WEATHER DANGER WILL BE HIGH TO
VERY HIGH WEST OF INTERSTATE 35 THIS AFTERNOON. CRITICAL OR
EXTREME FIRE WEATHER DANGER IS POSSIBLE FOR LOCATIONS GENERALLY
ALONG AND WEST OF A JACKSBORO TO LAMPASAS LINE IF WINDS ARE
STRONGER THAN FORECAST THIS AFTERNOON. LEVEL OF CONFIDENCE IN
HIGH FIRE DANGER IS HIGH. LEVEL OF CONFIDENCE IN EXTREME FIRE
WEATHER DANGER IS LOW.
WITH REGARDS TO THE STRONG WINDS BEHIND A COLD FRONT TONIGHT.
NORTH WINDS OF 25 TO 30 MPH...GUSTING TO 40 TO 45 MPH AT TIMES ARE
EXPECTED BEHIND THE COLD FRONT THROUGH SUNRISE. WINDS WILL BEGIN
TO DIMINISH IN INTENSITY FROM SUNRISE TO NOON ON WEDNESDAY. THE
LEVEL OF CONFIDENCE IN THESE STRONG WINDS IS HIGH...THEREFORE A
WIND ADVISORY WILL BE ISSUED FOR THE ENTIRE CWA FROM 10 PM THIS
EVENING TO NOON ON WEDNESDAY.
A FULL DISCUSSION INCLUDING REASONING AND THE REMAINDER OF THE
FORECAST WILL BE ISSUED LATER THIS MORNING.
CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 85 42 57 36 62 / 5 0 0 0 0
WACO, TX 82 41 58 33 60 / 5 0 0 0 0
PARIS, TX 80 41 54 32 61 / 0 0 0 0 0
DENTON, TX 85 39 57 31 63 / 5 0 0 0 0
MCKINNEY, TX 83 39 56 31 63 / 5 0 0 0 0
DALLAS, TX 84 43 57 38 62 / 5 0 0 0 0
TERRELL, TX 81 42 57 33 60 / 5 0 0 0 0
CORSICANA, TX 81 44 57 35 60 / 10 0 0 0 0
TEMPLE, TX 82 42 59 33 60 / 5 0 0 0 0
MINERAL WELLS, TX 88 38 56 33 62 / 0 0 0 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 10 PM THIS EVENING TO 1 PM CDT WEDNESDAY FOR
TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175.
&&
$$
/
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
403 AM CDT TUE MAR 11 2014
.SHORT TERM...
THE STAGE IS SET FOR A EARLY SPRING STRONG WIND/BLOWING DUST AND
FIRE WEATHER EVENT TODAY AND TONIGHT. 3 AM SAT IMAGERY AND UPPER-AIR
ANALYSIS SHOW A SHARP SHORTWAVE MOVING QUICKLY THROUGH THE
INTER-MOUNTAIN WEST. THIS WAVE WILL MOVE ROUGHLY EWD INTO THE
CENTRAL PLAINS TODAY...PLACING THE CWA ON THE SRN FLANK OF THE
MID-LVL JET MAX WITHIN THE BASE OF THE TROUGH. IN ADDITION...A WEAK
SFC TROUGH EXTENDING SWD FROM A LOW IN FAR NE COLO THROUGH THE WRN
PANHANDLES INTO ERN NM WILL DEEPEN AND MOVE EAST TODAY. TIGHTENING
THE SFC PRESSURE GRADIENT WHILE WINDS SWING AROUND TO THE WEST THEN
W-NW. FINALLY...A STRONG COLD FRONT IS MOVING INTO NRN COLO AND WRN
NE...THIS FRONT WILL BE THE MAIN DRIVER OF STRONG WINDS THIS
EVENING/TONIGHT...MORE ON THAT LATER.
WINDS ARE EXPECTED TO PICK UP PRETTY QUICKLY THIS MORNING...THE WEST
TEXAS SODAR AT REESE CENTER ALREADY SHOWS 30+ KTS AT 500 FT AGL.
WHILE WE DO HAVE SOME SHALLOW MOISTURE IN PLACE ACROSS THE ERN CWA
THIS MORNING...UNFORTUNATELY...THIS MOISTURE WILL BE SCOURED OUT
QUICKLY AND CRITICAL FIRE WEATHER CONDITIONS COULD DEVELOP BEFORE
NOON /SEE DISCUSSION BELOW/. IN GENERAL...WE EXPECT WINDS TO RISE
INTO THE 25 TO 35 MPH RANGE ACROSS THE AREA TODAY...SLIGHTLY
LOWER IN THE ROLLING PLAINS AND SLIGHTLY MORE ACROSS THE W-SW.
THESE WINDS WILL LIKELY REMAIN JUST BELOW ADVISORY LEVELS BUT
SHOULD BE SUFFICIENT TO LOFT SOME PATCHY BLOWING DUST. TEMPS WILL
BE QUITE WARM FOR MOST OF THE AREA...WITH HIGHS IN THE
80S...PERHAPS PUSHING 90F IN THE SRN ROLLING PLAINS...WHILE CAA
COMING IN FROM THE NW SHOULD KEEP TEMPS IN THE 70S ACROSS THE FAR
SW TX PANHANDLE AND WRN SPLNS.
LATE THIS AFTERNOON...ATTENTION WILL TURN TO THE COLD FRONT WHICH IS
EXPECTED TO BE BARRELING SOUTH THROUGH THE PANHANDLES. WHILE
GUIDANCE IS IN GOOD AGREEMENT THAT THE FRONT/S PROGRESS WILL BE
QUICKER IN THE EAST...LAGGING IN THE WEST...THERE IS STILL A FEW
HOURS OF DISAGREEMENT IN THE TIMING OF THE FRONT. WE ARE FAVORING
THE HIGH-RES GUIDANCE FROM THE RAP AND THE TTU-WRF...WHICH SHOWS THE
FRONT ENTERING CHILDRESS COUNTY AROUND 23 UTC...AND PARMER COUNTY
AROUND 00 UTC. BUT OF COURSE THE ACTUAL FROPA COULD VARY A COUPLE
HOURS EITHER WAY. AS NOTED PREVIOUSLY...MODELS ARE SHOWING VERY
IMPRESSIVE PRESSURE RISES BEHIND THE FRONT THIS EVENING. OBJECTIVE
GUIDANCE SUGGESTS THAT WIND SPEEDS COULD REACH HIGH WIND CRITERIA
/SUSTAINED SPEED OF AT LEAST 40 MPH AND/OR GUSTS IN EXCESS OF 57
MPH/ ACROSS THE NRN HALF OF THE FA. WE ARE A LITTLE SKEPTICAL THAT
WE WILL SEE SUSTAINED HIGH WINDS IN THE LOWER TERRAIN OF THE ROLLING
PLAINS...BUT WE ARE PLANNING ON EXTENDING THE HIGH WIND WATCH SOUTH
AND EAST ACROSS MUCH OF THE CAPROCK....WITH SOLID ADVISORY-LEVEL
WINDS EXPECTED ELSEWHERE.
SOMEWHAT INTERESTINGLY...THERE IS A PRONOUNCED WEAKNESS PROGGED IN
THE 800-700MB WIND FIELD ACROSS MUCH OF OUR AREA AROUND 0Z. THIS
SHOULD NOT HAVE MUCH OF AN IMPACT ON THE OVERALL FCST BUT DEPENDING
ON THE TIMING OF THE FRONT...IT COULD LEAD TO A SHORT-DURATION LULL
IN GUSTY WINDS BEFORE A BIG INCREASE WITH THE FROPA.
AS FOR BLOWING DUST...WE ARE LOOKING FOR A CONCENTRATION OF DIRT AND
REDUCTION IN VISIBILITY ALONG AND IMMEDIATELY IN THE WAKE OF THE
FRONT...BUT WE DON/T HAVE ANY STRONG INDICATIONS AT THIS TIME THAT
VISIBILITIES WILL DROP TO ADVISORY OR DUST STORM LEVELS. THIS IS
PARTLY DUE TO THE WIND DIRECTION AND OUR EXPECTATION THAT THE FRONT
WILL MOVE THROUGH AFTER PEAK MIXING. IF THE FRONT IS FASTER/STRONGER
THAN EXPECTED...THEN DENSE BLOWING DUST MAY BE A GREATER CONCERN.
&&
.LONG TERM...
AFTER THE ACTIVE SHORT TERM...THE EXTENDED FORECAST SEEMS RELATIVELY
BENIGN BY COMPARISON. GUSTY NORTHERLY WINDS EARLY WEDNESDAY WILL
GRADUALLY WEAKEN THROUGH THE DAY AS THE PRESSURE GRADIENT RELAXES
AND SURFACE RIDGING SETTLES SQUARELY OVER WEST TEXAS. IT WILL BE
CONSIDERABLY COOLER BEHIND THIS EVENINGS FROPA...WITH HIGHS ON
WEDNESDAY TOPPING OUT AROUND 10 DEGREES BELOW MID-MARCH AVERAGES.
SHORTWAVE RIDGING ALOFT WILL FOLLOW ON THURSDAY WHICH WHEN COUPLED
WITH RETURN FLOW ON THE BACK SIDE OF THE DEPARTING SURFACE RIDGE AND
RENEWED SURFACE TROUGHING IN THE LEE OF THE ROCKIES WILL MEAN BREEZY
SOUTHERLY WINDS WITH TEMPERATURES RECOVERING TO NEAR AVERAGE.
ATTENTION WILL THEN TURN WEST TO A CUTOFF UPPER LOW THAT WILL HANG
OUT OVER THE GREAT BASIN MID-WEEK. THIS UPPER LOW WILL GET KICKED
EASTWARD LATE WEEK AS JET ENERGY MOVES INTO THE PACIFIC NORTHWEST.
THERE REMAINS SOME TIMING DIFFERENCES...BUT WHAT IS LEFT OF THE
UPPER LOW WILL RACE ACROSS THE SOUTH PLAINS FRIDAY OR FRIDAY NIGHT.
UNFORTUNATELY...THIS SYSTEM WILL NOT HAVE MUCH IN THE WAY OF
LOW-LEVEL MOISTURE TO WORK WITH...BUT THE GFS AND ECMWF DO CONTINUE
TO PAINT POCKETS OF VERY LIGHT QPF SOMEWHERE IN OR NEAR THE CWA.
GIVEN THIS SIGNAL...WE WOULD NOT BE SURPRISED TO SEE A FEW SPRINKLES
OR LIGHT SHOWERS...BUT THE CHANCE OF MEASURABLE RAIN STILL APPEARS
LOW AND WE HAVE MAINTAINED POPS AROUND 10 PERCENT. THE TIMING
UNCERTAINTY WITH THE PASSING WAVE DOES ALSO CREATE LOWER CONFIDENCE
ON WHEN THE ASSOCIATED FROPA WILL OCCUR. A QUICKER SYSTEM/FRONT
COULD MEAN TEMPERATURES A LITTLE COOLER THAN WHAT IS CURRENTLY
DEPICTED IN THE FORECAST...THOUGH EITHER WAY THE SYSTEM WILL NOT
HAVE MUCH COOL AIR TO WORK WITH.
THE FIRST HALF OF THE WEEKEND WILL START OUT ON THE MILD SIDE...WITH
HIGHS EXPECTED TO TOP OUT IN THE 60S AND LOWER 70S. HOWEVER...A
SHORTWAVE TROUGH IS PROGGED TO DIVE SOUTH-SOUTHEASTWARD TOWARD THE
REGION SATURDAY NIGHT. AT A MINIMUM...THIS DISTURBANCE SHOULD HELP
DRIVE A DECENT COLD FRONT THROUGH...DROPPING TEMPERATURES BACK BELOW
AVERAGE FOR THE SECOND HALF OF THE WEEKEND. LESS CERTAIN IS EXACTLY
WHAT LONGITUDE THIS DISTURBANCE PASSES AND THUS WHETHER OR NOT IT
CAN BRING A WINDOW FOR PRECIPITATION CHANCES TO THE SOUTH PLAINS.
THE MOST RECENT ECMWF HAS TRENDED BACK FURTHER WEST AND
WETTER...WHILE THE GFS TRACK IS MORE EASTWARD WHICH WOULD LIKELY BE
DRY FOR THE SOUTH PLAINS. WE HAVE MAINTAINED SILENT POPS AROUND 10
PERCENT FOR NOW AND WILL WAIT TO MAKE A MOVE ONE WAY OR THE OTHER UNTIL
THE NWP CAN COME INTO BETTER AGREEMENT. REGARDLESS...WARMER AND
DRY WEATHER SHOULD KICK OFF EARLY NEXT WEEK AS THE UPPER TROUGH
DEPARTS AND SOUTHERLY TO SOUTHWESTERLY SURFACE FLOW REDEVELOPS.
&&
.FIRE WEATHER...
LATEST INDICATIONS ARE THAT CRITICAL FIRE WEATHER CONDITIONS WILL
DEVELOP ACROSS THE ENTIRE SOUTH PLAINS AREA TODAY AND WE WILL EXPAND
AND UPGRADE THE WATCH TO A RED FLAG WARNING FOR OUR WHOLE CWA.
DESPITE HIGH RH VALUES ACROSS THE EASTERN SOUTH PLAINS AND ROLLING
PLAINS EARLY THIS MORNING...VERY DRY AIR WILL SPREAD EAST RESULTING
IN RH VALUES DROPPING UNDER 15 PERCENT BY 10 AM FOR MANY AREAS...AND
INTO THE SINGLE DIGITS ACROSS THE ENTIRE AREA THIS AFTERNOON. WHILE
WIND SPEEDS MAY BE ON THE LOW END OF CRITERIA ACROSS THE ERN ROLLING
PLAINS...IT APPEARS THAT WIND SPEEDS AND RH VALUES WILL SUPPORT AN
EXTREMELY CRITICAL DANGER FOR MUCH OF THE SOUTHWEST AND SOUTHERN
SOUTH PLAINS. WINDS MAY RELAX FOR A PERIOD AROUND 6 TO 7 PM...BUT
THE PASSAGE OF A STRONG COLD FRONT IN THE EVENING WILL BRING AN
ABRUPT WIND SHIFT TO THE NORTH AND MUCH STRONGER WINDS SPEEDS.
ALTHOUGH COOLING TEMPS AND RISING RH VALUES WILL BEGIN TO REDUCE
THE FIRE DANGER...WE WILL KEEP THE RED FLAG WARNING GOING THROUGH
9 PM CDT DUE TO THIS STRONG FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 71 25 52 24 60 / 0 0 0 0 0
TULIA 76 28 54 25 63 / 0 0 0 0 0
PLAINVIEW 77 29 55 26 63 / 0 0 0 0 0
LEVELLAND 78 30 54 26 63 / 0 0 0 0 0
LUBBOCK 80 32 56 28 64 / 0 0 0 0 0
DENVER CITY 80 31 55 25 61 / 0 0 0 0 0
BROWNFIELD 81 33 56 26 63 / 0 0 0 0 0
CHILDRESS 83 34 58 31 65 / 0 0 0 0 0
SPUR 85 35 58 30 65 / 0 0 0 0 0
ASPERMONT 88 36 58 29 65 / 0 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM NOON CDT TODAY THROUGH THIS EVENING FOR
THE FOLLOWING ZONES: TXZ021>024-027>031-033>044.
HIGH WIND WATCH FROM THIS EVENING THROUGH LATE TONIGHT FOR THE
FOLLOWING ZONES: TXZ021>023-027-028.
&&
$$
33/23
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1058 PM PDT Mon Mar 10 2014
.SYNOPSIS...
Rain and snow will be ending overnight Monday. Quieter weather is
expected through Thursday. A weak weather front will bring light
rain to the area on Friday, with another chance of rain late
Sunday into next Monday.
&&
.DISCUSSION...
Made some updates to the forecast for this evening into tonight. I
trimmed out showers in the Spokane/Coeur d`Alene area and up much
of the Northern Panhandle. The surface low has pushed well into
Montana with the stratiform precip winding down across much of the
Central Panhandle Mountains (although some snow can be expected
over Lookout Pass this evening). The Spokane/Coeur d`Alene areas
did not see enough warming in the afternoon to achieve our
convective temperature; however, areas to the north and west are
seeing isolated showers developing. Temperatures are a bit too
cold for lightening with these showers, but thermal profiles are
more conducive for thunderstorms in the southeast from the
Northeast Blue Mtns to the Camas Prairie. Showers and
thunderstorms are expected to diminish this evening with skies
clearing. /SVH
&&
.AVIATION...
06Z TAFS: Showers across the region are beginning to wind down this
evening. Clearing skies will result in fog and low stratus in the
mountain valleys. Models are doing a poor job handling the moisture
near the surface, so forecast confidence is low with fog/stratus
tonight. KGEG, KSFF, KCOE, KPUW and KLWS will all see the potential
for some fog tonight with varying vis restrictions from LIFR to MVFR
possible. Drier air filtering in from Canada is expected to limit
the extent of low clouds, especially across the basin. /SVH
&&
.PREV DISCUSSION... /ISSUED 453 PM PDT Mon Mar 10 2014/
DISCUSSION...
Tonight...cold pool and its associated instability located behind
a passing cold front all exit to the southeast and east tonight.
Small scale triggers rotating around the edges of a small scale
low pressure area nested in this same cooler air will act as
triggers. Additionally there is an increase in instability due to
surface heating allowed by sun breaks across parts of the
lowlands between the east side of the Cascades and the Idaho
Panhandle. For all these reasons and a number of HRRR model runs
depicting just such a scenario the forecast holds onto showers
along with very low wet bulb zero heights allowing for a typical
spring rain/snow/graupel/soft-hail mix of precipitation for
mid-slope down to valley and lowland locations with the expectation
that any accumulation associated with most intense convective
cells will be on the order of minutes rather than hours if at all.
Thunderstorm mention remains southeast third of Washington and
southern half of North Idaho into early evening with idea that
they will be weak, low topped, single or multicell type with
potential to produce heavy rain and small soft hail/collapsed snow
and gusty wind. Storm motion should be southeast at about 25-35
mph. /Pelatti
Tuesday through next Monday: High pressure builds into the area on
Tuesday for drier conditions. We will likely see some late
night/morning fog and low clouds in the valleys, but otherwise
should be nice weather. A minor weather system clips by to our
north on Wednesday evening but we don`t expect much weather from
this, other than some perhaps some mountain wind.
The next real good chance of precipitation arrives on Friday. This
system has a decent moisture tap. But the westerly flow will keep
the precipitation largely confined to the Cascades and Panhandle
mountains. ECMWF is slightly slower and wetter than the GFS. Snow
levels will remain high (6000` south, 5000` north) so there will
be little if any impact from this system. Does not look like
enough rain to cause any flooding concerns.
The weather system on it`s heels looks a little more formidable.
This wave has a narrow but well-defined moisture plume associated
with it. Initially it looks impressive with heavy rain pointed
into Vancouver Island and NW Washington. But as it moves eastward,
the GFS model spins up a low along this front well to our south
(west of San Francisco). This cuts off the moisture supply and we
are left with a dying frontal passage. The ECMWF meanwhile doesn`t
show this, and has a more consolidated wet front moving through on
Sunday night.
Temperatures ahead of this front have the potential to be the
warmest of the season so far, nearing 60F in the Spokane area. But
it won`t take much change in the timing to render a cooler and
wetter day for Sunday than currently forecast. Snow levels will
be very high (7000-8000`) so the passes will be all rain. The snow
levels lower by Monday morning and continue to lower during the
day. RJ
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 30 48 27 53 32 55 / 10 0 0 0 0 0
Coeur d`Alene 29 47 26 52 30 54 / 10 0 0 0 0 0
Pullman 32 48 28 54 34 55 / 50 0 0 0 0 0
Lewiston 35 54 33 60 36 62 / 40 0 0 0 0 0
Colville 29 53 26 54 27 55 / 20 0 0 0 0 0
Sandpoint 28 45 24 47 28 50 / 10 0 0 0 10 10
Kellogg 30 45 29 49 31 50 / 40 10 0 0 0 0
Moses Lake 32 55 30 57 33 60 / 10 0 0 0 0 0
Wenatchee 32 53 32 55 33 57 / 10 0 0 0 0 0
Omak 28 52 28 53 30 56 / 20 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
309 PM CDT TUE MAR 11 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 309 PM CDT TUE MAR 11 2014
THE MAIN FOCUS THROUGH TOMORROW IS WITH HOW FAST THE BAND OF
PRECIPITATION SHIFTS TO THE SOUTH TONIGHT FOLLOWED BY SNOW SHOWER
CHANCES TOMORROW MORNING ALONG WITH HOW COLD IT WILL BE.
SURFACE/LOW LEVEL TEMPERATURES PROVED TO BE A TAD TOO WARM TODAY
TO CAUSE MUCH IF ANY SNOW TO DEVELOP ALONG THE BAND OF
PRECIPITATION. 11.17Z RAP SOUNDINGS CONTINUE TO SHOW THAT THE LOW
LEVELS SHOULD STAY WARM ENOUGH INTO THIS EVENING TO MAINLY YIELD
RAIN WITH A BRIEF TRANSITION TO SNOW ON THE BACK/NORTH SIDE OF
THE BAND. THE 17.12Z HRRR/RAP SHOW THIS BAND GETTING SOUTH OF
DUBUQUE BY MID EVENING.
AS A DEEPENING SURFACE LOW TRACKS TO THE SOUTHEAST OF THE REGION
OVERNIGHT INTO TOMORROW MORNING...AN INVERTED SURFACE TROUGH WILL
ROTATE FROM EAST TO WEST ACROSS THE REGION AS A SHORT WAVE MID
LEVEL TROUGH DROPS DOWN FROM ONTARIO. WITH COLDER AIR MOVING IN
WITH THIS TROUGH A SATURATED LAYER SHOULD DEVELOP IN THE
ICE NUCLEATION ZONE BELOW -8C WITH JUST ENOUGH LIFT FROM THE
SURFACE TROUGH TO PRODUCE SOME SNOW SHOWERS. 11.12Z WRF-ARW/NMM
REFLECTIVITY GUIDANCE SHOWS A BAND OF SNOW SHOWERS DEVELOPING IN
EASTERN WISCONSIN OVERNIGHT AND TRACKING TO THE SOUTHWEST THROUGH
THE REGION TOMORROW MORNING. SUBSIDENCE THEN TAKES OVER AND SHOULD
HELP TO CLEAR SKIES OUT A BIT GOING INTO THE AFTERNOON...BUT
TEMPERATURES WILL STRUGGLE TO CLIMB MUCH WITH 850MB TEMPERATURES
AROUND -15C.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 309 PM CDT TUE MAR 11 2014
THE NEXT CHANCE FOR SOME LIGHT SNOW COMES IN ON WEDNESDAY
NIGHT/EARLY THURSDAY MORNING AS A RIDGE OF HIGH PRESSURE PUSHES TO
THE EAST AND SOME LOW LEVEL WARM AIR ADVECTION SWINGS THROUGH THE
REGION. THERE ARE SOME DIFFERING OPINIONS BETWEEN THE 11.12Z
NAM/GFS/ECMWF/GEM WITH THIS BAND AND HOW STRONG THE WAA WILL BE.
THE GFS IS THE FASTEST WITH HAVING THE SNOW COME IN ON WEDNESDAY
EVENING WHILE THE NAM IS A TAD SLOWER AND STRONGER WITH THE WAA
AND PRODUCES A LITTLE MORE QPF. THE ECMWF/GEM ARE BOTH MUCH WEAKER
WITH THIS SYSTEM AND HARDLY SHOW ANY QPF AT ALL...SO THERE IS SOME
UNCERTAINTY WITH WHETHER ANYTHING WILL OCCUR FROM THIS. COBB DATA
FROM THE GFS/NAM WOULD SAY A HALF INCH OF ACCUMULATION OR LESS IF
THE SNOW DOES OCCUR.
TEMPERATURES WILL CLIMB BACK TOWARD NORMAL THURSDAY WITH
SOUTHWESTERLY SURFACE WINDS. A WEAK COLD FRONT WILL COME THROUGH
ON FRIDAY THOUGH TEMPERATURES SHOULD NOT DROP MUCH UNTIL THE
WEEKEND COMES AND NORTHWESTERLY FLOW ALOFT SETS UP. REMOVED THE
CHANCES FOR PRECIPITATION ON SUNDAY AS IT LOOKS LIKE THE SHORT
WAVE TROUGH DIVING SOUTH OUT OF SOUTH CENTRAL CANADA WILL RUN TO
THE WEST OF THE REGION. THE BETTER CHANCES APPEAR TO COME ON
TUESDAY AS THE 11.12Z ECMWF BRINGS A SYSTEM OUT OF THE PLAINS AND
TO THE SOUTH OF THE UPPER MISSISSIPPI RIVER VALLEY. THE 11.12Z GFS
IS MUCH FURTHER TO THE NORTH WITH THIS SYSTEM AND WOULD BRING
WARMER AIR INTO THE REGION. QUITE A BIT OF UNCERTAINTY OUT
THERE...BUT ENOUGH TO WARRANT SOME CHANCES FOR PRECIPITATION ON
TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1225 PM CDT TUE MAR 11 2014
A BAND OF -RA...AND A LITTLE -SN...WITH MVFR/LCL IFR CIGS/VSBYS WILL
CONTINUE TO SINK SOUTH ACROSS THE AREA EARLY THIS AFTERNOON. THIS
BAND LOOKS TO CLEAR THE TAF SITES BETWEEN 18-20Z WITH THE NORTH
WINDS BRINGING IN DRIER LOW LEVEL AIR...VFR VSBYS AND CIGS RISING
INTO THE 6K-10K FT RANGE. GENERALLY GOOD VFR CONDITIONS THEN
EXPECTED FOR MID TO LATE AFTERNOON INTO THE OVERNIGHT HOURS. ANOTHER
WEATHER DISTURBANCE WILL DROP ACROSS THE AREA LATE TONIGHT AND EARLY
WEDNESDAY MORNING. A PERIOD OF MVFR CIGS AND SCT FLURRIES/-SHSN
EXPECTED TO ACCOMPANY THIS DISTURBANCE ACROSS THE AREA...MAINLY
BETWEEN 09Z-15Z WED. SUBSIDENCE/DRYING BEHIND THIS FEATURE THEN
LOOKS TO DECREASE THE CLOUDS WITH VFR CONDITIONS FOR LATER WED
MORNING AND WED AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS ALBANY NY
204 AM EDT THU MAR 13 2014
.SYNOPSIS...
AS A STRONG STORM SYSTEM MOVES AWAY FROM THE
REGION...SNOW WILL TAPER TO SCATTERED SNOW SHOWERS AND FLURRIES FOR
TODAY...ALONG WITH GUSTY WINDS AND VERY COLD TEMPERATURES. HIGH
PRESSURE WILL ALLOW FOR A DRY BUT FRIGID NIGHT TONIGHT. MODERATING
TEMPERATURES WILL RETURN TO THE REGION FOR FRIDAY AND
SATURDAY...BEFORE YET ANOTHER SHOT OF COLD AIR MOVES INTO THE REGION
FOR SUNDAY AND EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 204 AM EDT...A STRONG AREA OF SURFACE LOW PRESSURE /AROUND
980 HPA/ IS NOW SITUATED NEAR CAPE COD AND IS CONTINUING TO
QUICKLY MOVE TOWARDS THE NORTHEAST. SOME WRAP AROUND AND
DEFORMATION SNOW IS OCCURRING ACROSS OUR REGION...MAINLY OVER THE
MOHAWK VALLEY...CAPITAL REGION AND WESTERN NEW ENGLAND. PERIODS OF
LIGHT SNOW LOOK TO CONTINUE FOR THE NEXT FEW HOURS...WITH
ADDITIONAL ACCUMULATION OF A COATING TO UP TO AN INCH OR TWO. BOTH
OUR LOCAL HIRESWRF AND THE 3KM HRRR ALL SHOW VERY LIGHT SNOW
SHOWERS CONTINUING FOR A FEW HOURS...BUT SHOULD BE WINDING DOWN
LATER IN THE NIGHT. WINTER STORM WARNINGS/WINTER WEATHER
ADVISORIES WILL CONTINUE FOR NOW...BUT LIKELY BE ABLE TO BE
CANCELLED LATER THIS MORNING AS SNOW WINDS DOWN.
OTHERWISE...SNOW WILL TAPER OFFF BY DAYBREAK WITH JUST SOME
LINGERING SNOW SHOWERS/FLURRIES...MAINLY FOR THE UPSLOPE FAVORED
AREAS OF THE ADIRONDACKS AND SRN GREEN MOUNTAINS. TEMPS WILL
CONTINUE TO RAPIDLY FALL OVERNIGHT...AS STRONG N-NW WINDS USHER IN
MUCH COLDER AIR. TEMPS WILL FALL INTO THE SINGLE DIGITS TO LOW
TEENS OVER THE ENTIRE AREA. ALONG WITH N-NW WINDS OF 10 TO 20 MPH GUSTING
UP TO 30 MPH...THIS WILL ALLOW FOR SOME COLD WIND CHILLS...WITH
VALUES APPROACHING -15 TO -20 DEGREES OVER THE HIGH TERRAIN. SOME
BLOWING/DRIFTING OF SNOW WILL OCCUR ACROSS THE ADIRONDACKS AS WELL.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
SOME SNOW SHOWERS ARE EXPECTED ON THURSDAY...WITH LITTLE IF ANY
ADDITIONAL ACCUMULATIONS. THE WIND WILL CONTINUE TO GUST OUT OF THE
NORTHWEST 35-40 MPH. SOME SUNSHINE SHOULD RETURN BY AFTERNOON.
BLOWING AND LOCALIZED DRIFTING SNOW WILL CONTINUE TO A PROBLEM FOR
THE MORNING FOR THE ADIRONDACKS. THE WIND WILL RELAX BY LATE IN THE DAY.
WITH H850 TEMPERATURES DOWN TO -20C TO -24C...EVEN WITH THE MARCH
SUNSHINE...TEMPERATURES ON THURSDAY WILL STRUGGLE TO GET OUT OF
THE TEENS FROM THE CAPITAL REGION NORTHWARD...LOWER TO MID 20S TO
THE LEE OF THE CATSKILLS AND LITCHFIELD COUNTY.
HIGH PRESSURE WILL CREST TO OUR SOUTH THURSDAY NIGHT. THE
COMBINATION OF FRESH SNOW (MAINLY ALBANY NORTHWARD) AND GENERALLY A
MAINLY CLEAR SKY AND LIGHT WIND SHOULD ALLOW FOR GOOD RADIATIONAL
COOLING. SINCE TEMPERATURES WILL START OUT UNSEASONABLY COLD...THEY
WILL ONLY GET COLDER THURSDAY. THEY LOOK TO TUMBLE ZERO TO 10 BELOW
NORTH OF ALBANY...ZERO TO 10 ABOVE ALBANY SOUTH. THESE VALUES WILL
BE CLOSE TO...BUT NOT QUITE RECORD LOWS FOR FRIDAY MORNING.
FRIDAY...THE WIND WILL TURN SOUTHERLY AHEAD OF AN ONCOMING CLIPPER
SYSTEM. THE SOUTHERLY WIND ALONG WITH A SUNNY START TO THE DAY WILL
ALLOW TEMPERATURES TO BOUNCE BACK INTO THE 30S...STILL SHORT OF
NORMAL BUT MODERATING.
THE CLIPPER SYSTEM LOOKS MOISTURE STARVED...BUT COULD BRING SOME
SNOW SHOWERS TO MAINLY OUR NORTHERN AREAS...WITH SNOWFALL AMOUNTS OF
NO MORE THAN A COATING TO TWO INCHES MAINLY FRIDAY NIGHT. CLOUDS...
AND SOUTHERLY FLOW WILL ALLOW FOR NOT NEARLY AS COLD A NIGHT FRIDAY
NIGHT...WITH LOWS RANGING FROM THE LOWER 30S IN THE CAPITAL
REGION...TO 20S MOST OTHER PLACES.
SATURDAY...THE COLD FRONT PORTION OF THE CLIPPER MOVES THROUGH ON
SATURDAY. H850 TEMPERATURES WILL BE JUST A LITTLE UNDER 0C SO WITH
GOOD MIXING AND SOME LIMITED SUNSHINE...TEMPERATURES LOOK TO REACH
AROUND 50 IN THE MID HUDSON VALLEY/LOWER LITCHFIELD AND 40S MOST
OTHER PLACES...EXCEPT 30S ACROSS THE ADIRONDACKS AND SOUTHERN
GREENS. IT MIGHT GET JUST COLD ENOUGH TO INDUCE SOME LAKE ENHANCED
SHOWERS OF RAIN OR SNOW...MAINLY ACROSS THE ADIRONDACKS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A RELATIVELY QUITE BUT COLD WEATHER PERIOD EXPECTED SATURDAY NIGHT
THROUGH WEDNESDAY. MODELS NOW FORECAST THE LOW PRESSURE SYSTEM TO
MOVE OFF THE COAST WELL TO OUR SOUTH SUNDAY NIGHT AND MONDAY WITH NO
PCPN MAKING IT INTO OUR AREA. THE ONLY OTHER SYSTEM EXPECTED TO
AFFECT THE REGION WILL BE A COLD FRONT LATE SATURDAY NIGHT INTO
SUNDAY MORNING...AND THEN A CLIPPER SYSTEM MOVING ACROSS SOUTHERN
CANADA MAY BRING SOME PCPN TO THE REGION TUESDAY NIGHT INTO
WEDNESDAY. HAVE ONLY FORECAST CHANCE POPS WITH THESE SYSTEM AS THE
MOVE THROUGH.
BELOW NORMAL TEMPS WILL BE THE RULE DURING THIS PERIOD. LOWS
SATURDAY NIGHT WILL BE IN THE TEENS TO MID 20S. HIGHS SUNDAY IN THE
20S OVER THE ADIRONDACKS AND UPPER 20S TO THE 30S ELSEWHERE. LOWS
SUNDAY NIGHT IN THE ZERO TO 5 BELOW RANGE OVER THE ADIRONDACKS...AND
SINGLE DIGITS TO MID TEENS ELSEWHERE. HIGHS MONDAY IN THE UPPER
TEENS TO NEAR 30S. LOWS MONDAY NIGHT NEAR ZERO OVER THE ADIRONDACKS
AND SINGLE DIGITS AND TEENS ELSEWHERE. HIGHS TUESDAY IN THE MID 20S
TO MID 30S. LOWS TUESDAY NIGHT IN THE UPPER SINGLE DIGITS TO LOWER
20S. HIGHS WEDNESDAY IN THE 30S.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
COLDER AIR CONTINUES TO POUR INTO THE REGION AS A DEEP LOW MOVES
NORTHEASTWARD UP THE NEW ENGLAND COAST. THE PRECIPITATION HAS
CHANGED TO ALL SNOW WITH THE HEAVY PRECIPITATION OFF TO THE EAST.
LIGHT SNOW WILL PERSIST ACROSS MUCH OF THE AREA THROUGH THE EARLY
MORNING HOURS AS THE UPPER TROUGH ASSOCIATED WITH THE LOW SWINGS
OVERHEAD THIS MORNING. RIDGING WILL BEGIN TO BUILD IN AT THE SURFACE
THIS AFTERNOON WITH HEIGHTS ALOFT BEGINNING TO RISE THIS EVENING.
LOOKING AT MAINLY MVFR CONDITIONS AT THE TAF SITES EARLY THIS
MORNING WITH IFR CONDITIONS AT TIMES DUE TO VISIBILITIES/SNOW AT
KALB...KPSF AND KGFL. MVFR CONDITIONS SHOULD LINGER A BIT LONGER AT
KGFL...OTHERWISE VFR CONDITIONS ARE EXPECTED BY SUNRISE. CLOUD COVER
WILL DECREASE DURING THE AFTERNOON ESPECIALLY LATE. MOSTLY CLEAR
SKIES ARE EXPECTED THIS EVENING.
THE PRESSURE GRADIENT ACROSS THE REGION WILL BE VERY TIGHT TODAY
BETWEEN THE DEPARTING LOW AND THE ADVANCING RIDGE. NORTHWESTERLY
WINDS OF 15 TO 20 KNOTS ARE EXPECTED WITH GUSTS OF 25 TO 30 KNOTS.
THE WINDS WILL BEGIN TO WEAKEN EARLY THIS EVENING.
OUTLOOK...
FRI NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
SAT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN.
SAT NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
SUN: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
SUN NIGHT-MON: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.HYDROLOGY...
ALL LOCATIONS ACROSS THE HSA ARE NOW BELOW FREEZING. MOST
PRECIPITATION HAS ENDED AS WELL...WITH JUST A FEW LINGERING AREAS
OF LIGHT SNOW OR SNOW SHOWERS FOR THIS MORNING. AS A RESULT...ANY
RUNOFF SHOULD EITHER SLOW DOWN SIGIFNICANTLY OR END. MANY RIVERS
AND STREAMS SAW SOME RISES DUE TO THE PRECIPITATION...BUT NONE
CAME CLOSE TO FLOOD STAGE...AND THERE WAS LITTLE ICE BREAKUP AND
MOVEMENT. RIVERS SHOULD SOON CREST...AND BEGIN TO SLOWLY RECEDE
FOR THE NEXT FEW DAYS.
COLD WEATHER WILL BE IN PLACE FOR TODAY INTO FRIDAY WITH TEMPERATURES
BELOW NORMAL. DAYTIME TEMPERATURES WILL RETURN TO NEAR NORMAL ON
SATURDAY WITH 40S FOR MOST AREAS...BUT WITH OVERNIGHT LOWS
DROPPING BELOW FREEZING...ANY SNOW MELT SHOULD BE SLOW AND NOT
CAUSE ANY HYDROLOGIC ISSUES. COLDER TEMPERATURES WILL RETURN ONCE
AGAIN FOR SUNDAY AND INTO EARLY NEXT WEEK.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 11 AM EDT THIS MORNING FOR
CTZ001-013.
NY...WINTER WEATHER ADVISORY UNTIL 11 AM EDT THIS MORNING FOR
NYZ049-050-052>054-058>061-063>066.
WINTER STORM WARNING UNTIL 11 AM EDT THIS MORNING FOR NYZ032-
033-038>043-047-048-051-082>084.
MA...WINTER WEATHER ADVISORY UNTIL 11 AM EDT THIS MORNING FOR
MAZ001-025.
VT...WINTER STORM WARNING UNTIL 11 AM EDT THIS MORNING FOR
VTZ013>015.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...HWJIV
LONG TERM...GJM
AVIATION...IAA
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS JACKSON KY
148 AM EDT THU MAR 13 2014
.UPDATE...
ISSUED AT 141 AM EDT THU MAR 13 2014
BASED ON CURRENT RADAR TRENDS...SNOW SEEMS TO BE EXITING THE REGION
AT A FASTER RATE THAN WAS ORIGINALLY FORECASTED. THE SAME IS TRUE
FOR CLOUD COVER. SOME LIGHT RETURNS ARE STILL MOVING INTO THE SW CWA
FROM CENTRAL KY...BUT KSME ASOS HAS YET TO PICK UP ON ANY ACTIVITY
FROM THESE RETURNS...SO EXPECT IT IS MAINLY FLURRIES. AS A
RESULT...UPDATED SKY...POPS...AND WEATHER THROUGH THE REMAINDER OF
THE NIGHT...WITH SNOW EXITING THE REGION OVER THE NEXT FEW HOURS. MAY
END UP NEEDING TO UPDATE AGAIN IN A COUPLE HOURS TO RID OF SNOW
COMPLETELY IF THIS CURRENT RATE OF EXIT CONTINUES. HOWEVER...WITH
SOME CLOUD COVER REMAINING ACROSS THE REGION /AND THOSE RETURNS
SHOWING UP OVER THE SW/...IT IS POSSIBLE THAT SOME REDEVELOPMENT COULD
STILL OCCUR. OTHERWISE...LOADED IN THE LATEST TEMP...WIND...AND DEW
POINT OBSERVATIONS TO THE CURRENT FORECAST...BUT EVERYTHING SEEMS TO
BE VERY WELL ON TRACK WITH THE ONGOING CONDITIONS.
UPDATE ISSUED AT 1110 PM EDT WED MAR 12 2014
THE GRIDS HAVE BEEN FRESHENED UP BASED ON RECENT RADAR TRENDS. NEARLY AN
INCH OF SNOW HAS FALLEN SO FAR THIS EVENING AT JKL WITH ABOUT AN INCH
REPORTED FROM A SPOTTER AT THORNTON IN LETCHER COUNTY. MOST OF THE
REMAINING SNOW SHOWERS OVERNIGHT SHOULD BE OVER THE NE COUNTIES AND
TO THE SOUTH AND EAST OF JKL OVERNIGHT. TEMPERATURES HAVE BEEN A BIT SLOWER
TO DROP OFF THIS EVENING THAN EXPECTED AND OPTED TO INCREASE MIN T A
DEGREE OR TWO ON AVERAGE. WE HAVE ISSUED AN SPS TO HIGHLIGHT THE
POTENTIAL FOR ROADS TO BECOME ICY OVERNIGHT WITH SCATTERED SNOW SHOWERS
AND POSSIBLY ANY LINGERING WATER FREEZING. THE WSW REMAINS IN EFFECT
FOR THE HIGHER TERRAIN NEAR THE VA BORDER. CONSIDERING THE SNOWFALL
AT JKL AND THE SPOTTER REPORT IN LETCHER COUNTY WE HAVE OPTED TO MOVE
THE REFERENCE IN THE WSW DOWN TO 2000 FEET. HOURLY GRIDS HAVE BEEN
FRESHENED UP.
UPDATE ISSUED AT 830 PM EDT WED MAR 12 2014
WIND GUSTS HAVE SLACKENED TO 30 MPH OR LESS AND THUS WE HAVE OPTED TO
CANCEL THE WIND ADVISORY EARLY. MOIST NORTHWEST FLOW IS BRINGING
SNOW SHOWERS TO MUCH OF THE REGION. SOME OF THE RIDGETOPS...PARTICULARLY
THOSE ABOVE 2000 FEET ARE BELOW FREEZING WITH THESE HIGHEST OF
ELEVATIONS NOW IN THE MID AND UPPER 20S. RADAR TRENDS AND THE 18Z NAM
SEEM TO FAVOR THE MOST PERSISTENT SNOW SHOWERS OVER THE FEW HOURS
NEAR OR JUST WEST OF JKL SOUTH INTO HARLAN AND LETCHER COUNTIES. THE
SFC LOW IS NOW CENTERED IN THE VICINITY OF NEW YORK CITY WITH COLDER AND
DRIER AIR ADVECTING SOUTH ON THE WEST SIDE OF THE LOW. AS THE SYSTEM
PULLS ON OFF FURTHER TO THE NORTH AND EAST...AND THE UPPER LEVEL
TROUGH EXITS TO THE EAST OVERNIGHT...SFC HIGH PRESSURE WILL BUILD
TOWARD THE REGION. THIS SHOULD LEAD TO A GRADUAL TAPERING OF THE SNOW
SHOWERS TO FLURRIES LATER ON TONIGHT INTO EARLY ON THURSDAY. AT THIS POINT...
THE INHERITED LOW TEMPERATURES LOOK FINE. HOURLY TEMPERATURE
AND DEWPOINT CURVES AS WELL AS WINDS HAVE BEEN ADJUSTED BASED ON
RECENT TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 315 PM EDT WED MAR 12 2014
18Z SFC ANALYSIS SHOWS THE DEEP LOW NOW OVER SOUTHWESTERN
PENNSYLVANIA WITH ITS COLD FRONT EAST OF KENTUCKY. THIS FRONT WAS
ACCOMPANIED AND TRAILED BY THE HIGHEST WINDS OF THE DAY WITH MANY
GUSTS TO 45 AND 50 MPH REPORTED IN ADDITION TO A 54 MPH GUST AT THE
KNOTT COUNTY MESONET. THE WINDS WILL CONTINUE GUSTY INTO THE EVENING
AS THE COLD AIR CONTINUES TO POUR INTO THIS PART OF THE STATE. THESE
WINDS ARE BRINGING IN THE SOON TO BE SUB FREEZING AIR WITH MID 30S
ALREADY NOTED IN THE NORTHWEST PARTS OF THE AREA WHILE MID 40S HOLD
IN THE FAR EAST...THOUGH BLACK MOUNTAIN IS DOWN TO 38 DEGREES.
DEWPOINTS ARE IN THE LOWER 30S NORTH TO THE UPPER 30S ACROSS THE
SOUTHEAST.
THE UPSLOPE FLOW IS KICKING IN ACROSS THE AREA AND WE CAN SEE THE
RAIN SHOWERS REDEVELOPING THROUGH THE HEART OF THE CWA. SOME FLURRIES
HAVE BEEN REPORTED WITH THESE HERE AT JKL...AND ALSO IN OUR NORTHERN
FRINGES...ON TRACK WITH EXPECTATIONS AND TIMING FROM THE LATEST HRRR.
THIS MODEL ALSO HAS BETTER REDEVELOPMENT OF SNOW TOWARD DUSK. AFTER
REVIEWING THE LATEST MODEL GUIDANCE...AND IN PARTICULAR THE
HRRR...HAVE DECIDED TO HOIST A WINTER WEATHER ADVISORY FOR THREE OF
OUR NORTHERN BORDER COUNTIES WITH VIRGINIA FOR A 1 TO 2 INCH SNOWFALL
MAINLY AT ELEVATIONS ABOVE 2500 FEET.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE DEEP LATE WINTER
TROUGH CROSSING THE OHIO VALLEY TONIGHT. THEY ALL HAVE ENERGY
WRAPPING IN HERE THROUGH 12Z THURSDAY BEFORE THE MASS OF IT PULLS
OFF THE EAST AND HEIGHTS QUICKLY RISE DURING THE DAY THURSDAY. THESE
HEIGHTS FLATTEN OUT LATER THURSDAY NIGHT AS A SHALLOW TROUGH MOVES
THIS WAY FROM THE NORTHERN PLAINS. WITH THIS GOOD AGREEMENT...AND THE
ONGOING WINTER STORM...HAVE LEANED MOST HEAVILY ON THE HIGHER
RESOLUTION NAM12 AND HRRR FOR WEATHER DETAILS.
SENSIBLE WEATHER WILL FEATURE THE UPSLOPE RAIN...CHANGING TO SNOW
LATE THIS AFTERNOON AND EARLY EVENING AND THEN CONTINUING THROUGH
THE EVENING FOR MOST LOCATIONS. THE SNOW WILL LINGER THE LONGEST IN
THE FAR EASTERN PARTS OF THE AREA THROUGH THE MIDDLE OF THE NIGHT.
LOOKING AT AN INCH OR LESS OF ACCUMULATION FOR MOST AREAS...WITH
THOSE HIGHER TOTALS MAINLY ON THE RIDGES. DO EXPECT NEARLY ALL SPOTS
TO GET A DUSTING OF SNOW EVEN IN THE VALLEYS...BUT THE LAG IN THE
COOLING OF THE ROADS SHOULD KEEP THEM MOSTLY CLEAR. THE FAR SOUTHEAST
PARTS OF THE CWA ARE A BIT DIFFERENT...THOUGH...AS THE UPSLOPE WILL
HOLD IN LONGER THERE...TEMPERATURES ARE DROPPING OFF QUICKER IN THE
HIGHER ELEVATIONS...THE HRRR IS HITTING THEM HARDEST WITH QPF...AND
THEY HAVE HIGHER ELEVATION WELL TRAVELED ROADS. FOR THESE REASONS
HAVE ISSUED A WSW FOR HARLAN...LETCHER...AND PIKE COUNTIES THROUGH
4Z...MATCHING UP WITH MRX IN WISE COUNTY.
THE SNOW WILL TAPER TO FLURRIES AND END LATE TONIGHT AND EARLY
THURSDAY MORNING FROM WEST TO EAST. TEMPERATURES WILL BOTTOM OUT IN
THE UPPER TEENS MOST PLACES BY DAWN WITH STILL ENOUGH OF A BREEZE TO
GENERATE WIND CHILLS IN THE SINGLE DIGITS OR NEAR ZERO ON THE HIGHEST
RIDGES. THE LOW CLOUDS WILL CLEAR OUR LATER THURSDAY MORNING WITH
SUNSHINE LIKELY EVAPORATING ANY OF THE SNOW FROM THIS SYSTEM BY MID
AFTERNOON DESPITE TEMPERATURES STRUGGLING TO GET TOO DEEP INTO THE
30S. A PARTLY CLOUDY SKY ON THURSDAY NIGHT WILL SET THE STAGE FOR A
MILDER NIGHT...BUT THIS WILL ALSO REPRESENT A DECENT RIDGE TO VALLEY
TEMPERATURE SPLIT SET UP.
USED A MODIFIED COLDER VERSION OF THE CONSSHORT FOR TEMPS DURING THE
NEXT 24 HOURS AND THEN FAVORED THE NAM12 DIURNAL CURVE WITH ADJUSTED
CONSALL MAX AND MIN T STARTING POINTS THROUGH FRIDAY MORNING. ALSO...
USED THE BCCONSSHORT FOR TD AND WINDS WITH THE CONSALL AFTER THE
FIRST 24 HOURS. THESE WERE MASSAGED FOR THE CURRENT CONDITIONS AND
TRENDS. AS FOR POPS...ENDED UP ON THE HIGH SIDE OF ALL GUIDANCE GIVEN
ITS POOR HISTORY OF PICKING UP ON LOW QPF UPSLOPE SNOW EVENTS.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 325 PM EDT WED MAR 12 2014
SPLIT FLOW PATTERN WILL BE IN PLACE AT THE BEGINNING OF THE LONG
TERM PORTION OF THE FORECAST WITH NEAR ZONAL FLOW ACROSS THE OH AND
TN VALLEYS. AT THE SURFACE HIGH PRESSURE WILL BE TO OUR SOUTHEAST
WITH SOUTHWEST LOW LEVEL FLOW ACROSS OUR AREA. AS A RESULT TEMPERATURES
WILL WARM NICELY WITH MAXIMUM TEMPERATURES ON FRIDAY 20 TO 25
DEGREES WARMER THAN ON THURSDAY.
AS WE MOVE INTO THE WEEKEND A SOUTHERN STREAM SHORT WAVE WILL EMERGE
FROM THE SOUTHERN PLAINS WITH THE ASSOCIATED SURFACE LOW TRACKING
ACROSS THE LOWER MS VALLEY AND THE SOUTHEAST UNITED STATES. AT THE
SAME TIME A NORTHERN STREAM SHORT WAVE WILL BE DROPPING SE FROM THE
NORTHERN PLAINS. THE COMBINED EFFECTS WILL BE TO BRING A CHANCE OF
PRECIPITATION TO THE AREA FOR THE WEEKEND. THERE WILL ONLY BE LOW
CHANCES OF PRECIPITATION ON SATURDAY...WITH PRECIPITATION CHANCES
PEAKING ON SUNDAY. TEMPERATURES WILL BE WARM ENOUGH THAT ANY
PRECIPITATION FROM FRIDAY NIGHT INTO SUNDAY WILL BE IN THE FORM OF
RAIN. ENOUGH COLD AIR LOOKS TO WORK INTO THE AREA ON THE BACKSIDE OF
THE SYSTEM SUNDAY NIGHT INTO EARLY MONDAY MORNING THAT PRECIPITATION
COULD END AS SNOW. THERE IS NOT GOOD MODEL AGREEMENT AT THIS POINT
IN TIME...BUT SOME LIGHT SNOW ACCUMULATION LOOKS POSSIBLE.
THERE IS POOR MODEL AGREEMENT AS WE MOVE INTO NEXT WEEK AND
CONFIDENCE IN THE VARIOUS MODEL SOLUTIONS DECREASES. AFTER A COLD
START TO THE WEEK...TEMPERATURES WILL WARM...BUT THE WHEN AND WHERE
OF THE NEXT SHORT WAVE TO AFFECT THE AREA ARE UNCERTAIN. FOR NOW
WILL KEEP THE WEATHER DRY THROUGH TUESDAY NIGHT...AND BRING A SLIGHT
CHANCE OF SHOWERS INTO THE FAR WESTERN PART OF THE FORECAST AREA ON
WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 147 AM EDT THU MAR 13 2014
SNOW IS CONTINUING TO EXIT THE REGION AT A FASTER SPEED THAN WAS
ORIGINALLY ANTICIPATED. THE SAME IS TRUE FOR CLOUD COVER...WITH WHAT
IS LEFT OF THE CIGS ACROSS THE REGION BEGINNING TO LIFT TO MVFR AND VFR
LEVELS. THERE ARE STILL SOME RETURNS SHOWING UP OVER THE SW PORTION
OF THE CWA...INCLUDING KSME AND KLOZ...THOUGH ASOS/S ARE NOT PICKING
UP ON ANY SNOWFALL. HOWEVER...SOME REDEVELOPING SNOW SHOWERS COULD
NOT BE RULED OUT HERE OVER THE NEXT FEW HOURS...SO DID MAKE MENTION
OF A TEMPO GROUP TO ACCOUNT FOR THIS. KJKL SEEMS TO BE IN A CLEAR
SLOT...WHILE KSJS IS NOW SNOW FREE BUT WILL CONTINUE TO SEE THE
AFFECTS OF SOME OF THE LLVL CLOUDS FOR ANOTHER COUPLE OF HOURS. HOW
QUICKLY THESE CLOUDS CONTINUE TO LIFT AND MOVE OUT WILL DETERMINE IF
AN UPDATE TO THE ONGOING FORECAST WILL NEED TO BE MADE FOR KSJS.
OTHERWISE...HIGH PRESSURE WILL CONTINUE TO BUILD IN THROUGH THE
LATE NIGHT/MORNING...WITH WINDS CALMING...CLOUDS SCATTERING
OUT...AND DRY VFR CONDITIONS PREVAILING FOR THE REST OF THE FORECAST
PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR
KYZ088-118-120.
&&
$$
UPDATE...JMW
SHORT TERM...GREIF
LONG TERM...SBH
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
439 AM CDT THU MAR 13 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 436 AM CDT THU MAR 13 2014
FROM A STRICTLY TEMPERATURE/SKY COVER STANDPOINT...TODAY IS GOING
TO BE ANOTHER SPRING-FEVER SETUP WITH HIGHS CLIMBING RIGHT UP TO
AROUND 70 DEGREES IN ALL AREAS UNDER ESSENTIALLY WALL-TO-WALL
SUNSHINE. HOWEVER...FOR THOSE WITH POTENTIAL CONCERNS OF ENHANCED
FIRE DANGER THIS IS REALLY THE ONLY FLY IN THE OINTMENT...AND IN FACT
CONDITIONS HAVE BEEN DEEMED SEVERE ENOUGH TO JUSTIFY A CWA-WIDE
RED FLAG WARNING FOR THIS AFTERNOON. PLEASE REFER TO THE SEPARATE
FIRE SECTION BELOW FOR MUCH MORE DETAIL ON THESE ISSUES.
STARTING OFF WITH THE HERE AND NOW...11-3.9 MICRON SATELLITE
IMAGERY CONFIRMS THAT THERE ARE VIRTUALLY NO CLOUDS
TO SPEAK OF WHATSOEVER EARLY THIS MORNING...NOT ONLY WITHIN THE CWA
BUT ALSO EXTENDING SEVERAL HUNDRED MILES IN NEARLY ALL DIRECTIONS.
WATER VAPOR SATELLITE IMAGERY AND SHORT TERM MODEL DATA DEPICT THE
LOCAL AREA TO BE UNDER THE INFLUENCE OF DRY NORTHWESTERLY
FLOW/SUBTLE SHORTWAVE RIDGING OF A RIDGE AXIS CENTERED FROM
WYOMING-ONTARIO. MEANWHILE...A NEARLY STALLED-OUT MID LEVEL CLOSED
LOW CONTINUES CHURNING OVER SOUTHERN CA/NV. PUT ANOTHER WAY...THE
CENTRAL PLAINS IS UNDER AN UPPER LEVEL WIND MINIMUM IN BETWEEN THE
PRIMARY SPLIT UPPER JET STREAMS...WITH THE NORTHERN BRANCH
EXTENDING ACROSS THE CANADIAN BORDER AREA AND THEN SOUTHWARD
ACROSS THE GREAT LAKES...WHILE THE SOUTHERN BRANCH SNAKES ACROSS
THE SOUTHERN TIER OF THE CONUS. AT THE SURFACE...A FAIRLY WEAK
PRESSURE GRADIENT REGIME IS IN PLACE ACROSS THE AREA...WITH THE
CENTRAL PLAINS GENERALLY POSITIONED BETWEEN A TX RIDGE AXIS...AND
A LOW PRESSURE SYSTEM CENTERED WAY TO THE NORTH OVER SOUTH CENTRAL
CANADA. AS A RESULT...THE GENERAL PREVAILING BREEZE EARLY THIS
MORNING IS SOME VARIATION OF WESTERLY WITH SPEEDS ONLY 5-10 MPH.
DESPITE THESE LIGHT WESTERLY BREEZES...THE PRESENCE OF CLEAR SKIES
AND DRY AIR HAS ALLOWED A FAIRLY EFFICIENT TEMPERATURE DROP...AND
CURRENTLY HAVE MORNING LOW TEMPERATURES AIMED INTO THE 25-28 RANGE
ACROSS MOST OF THE AREA.
GETTING INTO THE DAYTIME HOURS TODAY...THE MID/UPPER LEVEL SCENE
INVOLVES A CONTINUATION OF THE AREA REMAINING IN BETWEEN THE
PRIMARY JET AXES...ALTHOUGH SLOWLY BUT SURELY FLOW WILL TRANSITION
FROM MORE NORTHWESTERLY TO MORE QUASI-ZONAL AS BOTH BRANCHES OF
THE JET SEND LOW AMPLITUDE SHORTWAVE TROUGHS EASTWARD AND
SOUTHEASTWARD TOWARD THE CENTRAL PLAINS. DESPITE THIS...BOTH
FORECAST SOUNDINGS AND PLAN-VIEW RELATIVE HUMIDITY PROGS SHOW A
REMARKABLY DRY DEEP-LAYER AIRMASS...AND OTHER THAN MAYBE A VERY
LIMITED COVERAGE OF THIN HIGH CIRRUS THIS AFTERNOON...WIDESPREAD
SUNSHINE IS DEFINITELY IN STORE. AT THE SURFACE...THE PRESSURE
GRADIENT WILL SHARPEN UP A BIT AS THE DAY GOES ON...IN RESPONSE TO
THE AFOREMENTIONED SOUTHERN CANADA LOW PRESSURE SYSTEM MIGRATING
DOWN TO NEAR THE NORTHERN TIP OF MN BY LATE AFTERNOON/EARLY
EVENING. AS THIS OCCURS...A TRAILING TROUGH AXIS WILL SHARPEN FROM
THE DAKOTAS SOUTH-SOUTHWESTWARD INTO EASTERN CO...OR GENERALLY
REMAINING JUST WEST OF THE CWA. WITHIN THIS PRESSURE FIELD...A
COUPLE OF MODEST LOWER-LEVEL WIND MAXIMUMS EVIDENT AT 850
MILLIBARS WILL SET UP...ONE MORE SOUTHWESTERLY AND EXTENDING FROM
SOUTH CENTRAL KS TO SOUTHEAST NEB...AND THE OTHER MORE WESTERLY
AND EXTENDING WEST-EAST ACROSS CENTRAL NEB. THANKS TO VERY DEEP
MIXING UP INTO THE 800-750MB LEVEL...IT WON/T TAKE MUCH TO
GENERATE SUSTAINED 15-20 MPH BREEZES WITH GUSTS TO AROUND 25 MPH
ACROSS MOST OF THE CWA FROM THE LATE-MORNING TO LATE-AFTERNOON
HOURS...WITH A BIT OF A LIGHTER WIND REGIME FOCUSING NEAR THE
SURFACE TROUGH AXIS IN THE FAR SOUTHWESTERN CWA...ESPECIALLY
AROUND FURNAS COUNTY. IN OTHER WORDS...IT WILL BE A BIT BREEZY
MUCH OF THE DAY BUT OVERLY WINDY. TEMP-WISE...AFTER HAVING DECENT
LUCK THE LAST FEW DAYS BLENDING THE 00Z NAM WITH A RECENT RAP13
RUN TO DERIVE HIGHS...TOOK THE SAME APPROACH FOR TODAY...WHICH
YIELDS GENERALLY A 1-3 DEGREE INCREASE IN MOST AREAS...NOW PUTTING
MOST PLACES SOMEWHERE IN THE 68-73 RANGE. IN CONTRAST...DEWPOINTS
WERE LOWERED SEVERAL DEGREES FROM PREVIOUS FORECAST...THUS PLAYING
INTO THE HIGH FIRE DANGER OUTLINED BELOW.
GETTING INTO THIS EVENING/TONIGHT BEYOND 00Z/7PM...THE PRIMARY
NORTHERN STREAM MOISTURE-STARVED MID LEVEL SHORTWAVE TROUGH WILL
SWING PRIMARILY ACROSS THE DAKOTAS-MN...AND ONLY GIVING THE LOCAL
AREA A GLANCING BLOW. DESPITE THIS DISTURBANCE MOVING
THROUGH...EXPECTING NO MORE THAN A SLIGHT INCREASE IN HIGH
CLOUDS...AND STILL AVERAGING MOSTLY CLEAR THROUGH THE NIGHT. THIS
DISTURBANCE WILL MAKE ITSELF A BIT MORE OBVIOUS DOWN AT THE
SURFACE...AS A MODEST COLD FRONT MAKES ITS WAY ACROSS THE CWA FROM
NORTHWEST-SOUTHEAST AS THE NIGHT GOES ON. INITIALLY BEFORE
MIDNIGHT...MOST PLACES WILL HOLD ONTO A WEST TO SOUTHWEST BREEZE
GENERALLY 5-15 MPH...BUT THEN AS THE FRONT MOVES THROUGH BREEZES
WILL SWITCH NORTHWESTERLY AT GENERALLY 10-15 MPH...WITH A BRIEF
PERIOD OF GUSTINESS TO AROUND 20 MPH LIKELY IN THE WAKE OF THIS
BOUNDARY...WHICH SHOULD CLEAR EVEN THE FAR SOUTHEAST CWA BY A FEW
HOURS BEFORE SUNRISE. TEMP-WISE...DESPITE DECENT MIXING BEHIND THE
PASSING COLD FRONT...THERE IS JUST ENOUGH LOW LEVEL COLD AIR
ADVECTION THAT WOULD EXPECT TO SEE A DECENT TEMPERATURE DROP
MAINLY LATE IN THE NIGHT/TOWARD SUNRISE FRIDAY MORNING. AS A
RESULT...ONLY TWEAKED PREVIOUS LOW TEMPS A FEW DEGREES MAINLY
DOWNWARD...WITH THE MAJORITY OF THE CWA AIMED INTO THE 31-35
RANGE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 436 AM CDT THU MAR 13 2014
GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC AND SREF-MEAN ALL
SUGGEST QUASI-ZONAL TO NORTHWESTERLY MID TO UPPER TROPOSPHERIC FLOW
WILL PERSIST OVER THE CENTRAL PLAINS DURING MUCH OF THE LONG TERM
FORECAST PERIOD. A MID-TROPOSPHERIC SHORT WAVE IS EXPECTED TO MOVE
ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY THURSDAY
NIGHT INTO FRIDAY...BUT ANY APPRECIABLE OMEGA IN ASSOCIATION THIS SHORT
WAVE SHOULD REMAIN WELL NORTHEAST OF OUR AREA. ANOTHER
MID-TROPOSPHERIC SHORT WAVE IS THEN EXPECTED TO MOVE EAST ACROSS THE
SOUTHERN PLAINS SATURDAY INTO SATURDAY NIGHT. A TRAILING
MID-TROPOSPHERIC PERTURBATION IS THEN EXPECTED TO MOVE SOUTHEAST
ACROSS THE CENTRAL HIGH PLAINS SATURDAY NIGHT INTO SUNDAY...WITH
THIS PERTURBATION EXPECTED TO EVENTUALLY MERGE WITH THE PRIMARY
MID-TROPOSPHERIC SHORT WAVE OVER THE SOUTHERN PLAINS DURING THE DAY
SUNDAY. AT THIS TIME IT APPEARS ANY APPRECIABLE OMEGA IN ASSOCIATION
WITH THE SHORT WAVE MOVING OVER THE SOUTHERN PLAINS WILL REMAIN WILL
SOUTH OF OUR AREA. WEAK OMEGA IN ASSOCIATION WITH TRAILING
PERTURBATION MAY BE JUST ENOUGH TO PROMOTE LIGHT PRECIPITATION ACROSS
PORTIONS OF OUR AREA SATURDAY NIGHT...A SOLUTION SUPPORTED BY QPF
FIELDS FROM NAM...EC AND SREF-MEAN. GIVEN THIS IS A QUICK-MOVING
CLIPPER WITH MODEST OMEGA AND QUESTIONABLE MID TO LOWER TROPOSPHERIC
MOISTURE...OPTED TO GO NO HIGHER THAN ~20% POPS ACROSS THE CWA
SATURDAY NIGHT. THAT BEING SAID...IT IS WORTH NOTING THAT THE NAM
AND SREF-MEAN BOTH SUGGEST THIS PERTURBATION WILL ACTUALLY STRENGTHEN
RATHER DRAMATICALLY OVER THE CENTRAL HIGH PLAINS...THUS RESULTING IN
AN AREA OF SURFACE CYCLOGENESIS OVER NORTHEASTERN NEBRASKA SUNDAY
NIGHT. ALTHOUGH THIS PERTURBATION...AND ASSOCIATED SURFACE LOW IF
REALIZED...ARE NOT EXPECTED TO LINGER NEAR THE AREA VERY LONG...BOTH
THE NAM AND SREF-MEAN SUGGEST THE INCREASING SOUTHEASTERLY LOWER
TROPOSPHERIC FLOW WILL RESULT IN A HEALTHY DOSE OF LOWER
TROPOSPHERIC THERMAL AND MOISTURE ADVECTION...WITH A BRIEF BUT
SUBSTANTIAL AXIS OF ISENTROPIC UPGLIDE NEAR THE 290K
SURFACE...RESEMBLING A TROWAL EXTENDING FROM SOUTHERN MISSOURI INTO
SOUTHEASTERN NEBRASKA AND THEN BACK INTO NORTH CENTRAL
KANSAS...LIKELY GRAZING OUR SOUTHEASTERN CWA. QPF FIELDS FROM
THE NAM RESPOND BY PRESENTING A BAND OF HEAVY PRECIPITATION OVER OUR
SOUTHEAST...WITH LIQUID PRECIPITATION AMOUNTS IN THE 0.25-0.50"
RANGE. CONTEMPLATED GOING WITH A HIGHER POP ACROSS OUR SOUTHEAST AS
A RESULT...BUT SINCE THE NAM AND SREF-MEAN ARE THE ONLY MODELS
SUGGESTING SUCH A SETUP...AND SINCE THE NAM IS THE ONLY MODEL
PRODUCING SUCH COPIOUS AMOUNTS OF PRECIPITATION...AND SINCE THE
OPERATIONAL GFS AND EC BOTH SUGGEST DRY CONDITIONS OR VERY LIGHT
PRECIPITATION ACROSS OUR SOUTHEAST...OPTED TO KEEP OUR SOUTHEAST IN
THE SAME ~20% POP BOAT AS THE REST OF THE CWA. CERTAINLY SOMETHING
TO MONITOR THROUGH THE NEXT FEW DAYS.
FORECAST PROXIMITY SOUNDINGS FROM THE ACROSS THE CWA...PER THE NAM
AND OPERATIONAL GFS...SUGGEST THE LOWER TROPOSPHERE WILL REMAIN WARM
ENOUGH FOR RAIN TO START SATURDAY NIGHT...BUT WILL EVENTUALLY COOL
TO SUPPORT SNOW PRODUCTION BY EARLY SUNDAY MORNING. GIVEN ALL
THIS..WENT AHEAD WITH A MIX OF RAIN AND SNOW IN THE OFFICIAL
FORECAST FOR SATURDAY NIGHT.
AS FOR THE REST OF THE LONG TERM FORECAST PERIOD...THERE ARE
INDICATIONS OF A LONGWAVE MID TROPOSPHERIC TROUGH SETTING UP OVER
THE WESTERN CONUS BY EARLY NEXT WEEK. MID TROPOSPHERIC THERMAL
ADVECTION...OR PERHAPS PERIODIC MID TROPOSPHERIC PERTURBATIONS
EJECTING FROM THE PRIMARY TROUGH AXIS...COULD PROMOTE JUST ENOUGH
OMEGA FOR PRECIPITATION PRODUCTION OVER THE AREA EARLY NEXT
WEEK...BUT AT THIS TIME THE PROBABILITY OF ACCURATELY PREDICTING
SUCH ACTIVITY IS TOO LOW TO JUSTIFY POPS. A DRY FORECAST HAS BEEN
PRESENTED SUNDAY AND BEYOND AS A RESULT.
LITTLE CHANGE IN THE LOWER TROPOSPHERIC AIR MASS SHOULD PROMOTE
AFTERNOON TEMPERATURE READINGS GENERALLY IN THE 50S AND 60S FRIDAY
AND SATURDAY. THE INTRUSION OF A COOLER LOWER TROPOSPHERIC AIR
MASS SHOULD THEN PROVIDE HIGHS IN THE 40S AND LOW 50S ON
SUNDAY...WITH HIGHS REBOUNDING INTO THE 50S AND 60S TO FINISH THE
FORECAST PERIOD. OVERNIGHT LOWS IN THE 20S AND 30S ARE EXPECTED FOR
THE MOST PART DURING THE LONG TERM FORECAST PERIOD.
&&
.AVIATION...(FOR THE 06Z KGRI TAF THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1253 AM CDT THU MAR 13 2014
CONFIDENCE REMAINS QUITE HIGH IN VFR CEILING/VISIBILITY THROUGH
THE NEXT 24 HOURS...AS THE AIRMASS THROUGH A DEEP LAYER OF THE
TROPOSPHERE REMAINS VERY DRY AND IN FACT SKIES SHOULD ESSENTIALLY
REMAIN CLEAR THE ENTIRE TIME. AS FOR SURFACE WINDS...THERE WILL
REALLY BE 3 DISTINCT REGIMES. STARTING OFF NOW THROUGH LATE
MORNING...DIRECTION WILL AVERAGE WESTERLY AT SPEEDS UNDER 10KT.
THEN...MUCH LIKE ON WEDNESDAY...THE LATE MORNING THROUGH LATE
AFTERNOON HOUR WILL FEATURE A DECENT UPSWING IN WIND SPEEDS...BUT
THIS TIME OUT OF THE SOUTHWEST WITH SUSTAINED SPEEDS UP INTO THE
15-20KT RANGE AND GUST POTENTIAL AT LEAST 20-25KT. BY EARLY
THURSDAY EVENING...BREEZES WILL AGAIN DIE BACK DOWN TO SUSTAINED
VALUES AROUND 10KT...BUT TOWARD THE VERY END OF THE PERIOD THE
LEADING EDGES OF A WEAK COLD FRONT WILL TURN DIRECTION
NORTHWESTERLY.
&&
.FIRE WEATHER...
ISSUED AT 436 AM CDT THU MAR 13 2014
AS HAS BEEN ADVERTISED FOR A FEW DAYS NOW...TODAY CONTINUES TO
LOOK MORE AND MORE LIKE THE OVERALL-WORST DAY THIS WEEK FOR FIRE
DANGER ACROSS THE AREA (SINCE SUNDAY OF COURSE)...AND AS A RESULT
A CWA-WIDE RED FLAG WARNING HAS BEEN ISSUED FOR THIS AFTERNOON
THROUGH 00Z/7PM. BEFORE GOING ON...WANT TO BRIEFLY REMIND THAT
FOR OUR CWA CRITICAL FIRE THRESHOLDS ARE THE OVERLAP OF SUSTAINED
WINDS AND/OR GUSTS OF 20/25 MPH AND RELATIVE HUMIDITY (RH) OF 20
PERCENT OR LESS FOR 3+ HOURS...IN THE PRESENCE OF VERY DRY
VEGETATION (FUELS).
IN TODAY/S CASE...ITS REALLY THE LOW RH COMPONENT OF THE EQUATION
THAT HAS TIPPED THE SCALES TOWARD RED FLAG WARNING
ISSUANCE...WITH WIND SPEEDS LOOKING A BIT MORE MARGINAL. AS A
RESULT OF BUMPING UP HIGH TEMPERATURES A FEW DEGREES AND ALSO
LOWERING AFTERNOON DEWPOINTS AT LEAST A FEW DEGREES...WIDESPREAD
RH VALUES DOWN INTO THE 10-17 PERCENT RANGE ARE FORECAST FOR THIS
AFTERNOON. ALTHOUGH THIS IS ALREADY SOLIDLY INTO CRITICAL
TERRITORY..ITS WORTH NOTING THAT HIGH-RES SHORT TERM MODELS SUCH
AS THE RAP13 AND HRRR SUGGEST THAT SOME PLACES COULD SEE RH
VALUES DROP A FEW PERCENTAGE POINTS LOWER YET...AND THIS WILL NEED
MONITORED. AS FOR THE WIND ASPECT OF THE SITUATION...THINGS ARE A
BIT MORE IFFY AS SUSTAINED WINDS ARE CURRENTLY EXPECTED TO PREVAIL
FROM THE SOUTHWEST AT MAINLY 15-20 MPH IN MOST AREAS...OR
GENERALLY JUST BELOW CRITICAL THRESHOLDS. HOWEVER...GIVEN THE
PRESENCE OF DEEP MIXING UP INTO THE 800-750 MILLIBAR LEVEL PER
VARIOUS FORECAST SOUNDINGS...FEEL THAT POTENTIAL IS PRETTY HIGH
FOR SEMI-FREQUENT GUSTS OF 25+ MPH TO MATERIALIZE...ESPECIALLY
ACROSS NORTHERN AND EASTERN PORTIONS OF THE NEBRASKA CWA AND ALSO
MOST KS ZONES. HOWEVER...THANKS TO THE PRESENCE OF A LOW LEVEL
TROUGH AXIS STRETCHING EAST-NORTHEAST OUT OF EAST-CENTRAL
CO...SOMEWHAT LIGHTER BREEZES ARE EXPECTED WITHIN A HANDFUL OF
COUNTIES IN THE SOUTHWESTERN CWA...ESPECIALLY FURNAS COUNTY WHERE
EVEN GUSTS COULD STRUGGLE TO CONSISTENTLY EXCEED 15-20 MPH.
DESPITE SOMEWHAT OF A WIND-MINIMUM IN THIS SOUTHWESTERN
AREA...HAVE OPTED TO ERR ON THE SIDE OF CAUTION GIVEN SUCH LOW
RELATIVE HUMIDITY VALUES AND DRY FUELS..AND JUST INCLUDE THE
ENTIRE CWA IN THE RED FLAG WARNING.
LOOKING AHEAD TO FRIDAY...AFTERNOON TEMPERATURE READINGS GENERALLY
IN THE LOWER 60S WILL WORK IN CONCERT WITH DEW POINT READINGS IN
THE LOWER 20S TO PROMOTE RELATIVE HUMIDITY READINGS NEAR 20%
ACROSS MUCH OF THE CWA FRIDAY AFTERNOON. THANKFULLY...A DECREASING
LOWER TROPOSPHERIC PRESSURE GRADIENT SHOULD PROMOTE AN AFTERNOON
SURFACE WIND OF ONLY 5-10 MPH. AS A RESULT...CRITICAL FIRE WEATHER
CONDITIONS ARE NOT EXPECTED...AND GIVEN THE VERY LIGHT LOWER
TROPOSPHERIC WIND FIELD...WILL ALSO HOLD OFF FROM ANY FIRE WEATHER
MENTION IN THE HWO.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS
EVENING FOR NEZ039>041-046>049-060>064-072>077-082>087.
KS...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS
EVENING FOR KSZ005>007-017>019.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...BRYANT
AVIATION...PFANNKUCH
FIRE WEATHER...PFANNKUCH/BRYANT
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1245 AM CDT THU MAR 13 2014
.UPDATE...
ISSUED AT 1245 AM CDT THU MAR 13 2014
WARM AIR ADVECTION CONTINUES ACROSS WESTERN AND CENTRAL NORTH
DAKOTA WITH WEAK 3HR SURFACE PRESSURE FALLS. SATELLITE IMAGERY
CONTINUES TO SHOW A MOSTLY CLEAR SKY. PATCHY FOG POSSIBLE IN THE
JAMES RIVER VALLEY AND WILL CONTINUE WITH THIS THOUGHT FROM
PREVIOUS DISCUSSION. ONLY UPDATE WAS TO POPULATE HOURLY SENSIBLE
WEATHER ELEMENTS WITH TRENDS WELL HANDLED FROM EARLIER FORECASTS.
FOR HYDROLOGY...WE HAVE ISSUED A FLOOD WARNING FOR THE BEAVER CREEK
NEAR LINTON WITH MINOR FLOODING OCCURRING AND MODERATE FLOODING
EXPECTED BEFORE DAYBREAK THURSDAY. PLEASE SEE WWW.WEATHER.GOV/BIS
FOR FURTHER DETAILS.
UPDATE ISSUED AT 1016 PM CDT WED MAR 12 2014
LATEST SATELLITE LOOP SHOWS A CLEAR SKY ACROSS WESTERN AND CENTRAL
NORTH DAKOTA. THE HRRR ADVERTISES SOME POTENTIAL OF FOG IN THE
JAMES RIVER VALLEY OVERNIGHT WHERE TEMPERATURES AND DEWPOINTS ARE
ALREADY THE SAME AND RH IS 100 PERCENT. CANNOT RULE THIS OUT AND
HAVE ADDED THIS IN THE GRIDS. WARM AIR ADVECTION CONTINUES
OVERNIGHT INTO THURSDAY MORNING. NO SIGNIFICANT ADJUSTMENTS THIS
UPDATE AS THE FOREACST ELEMENTS REMAIN IN GOOD SHAPE.
UPDATE ISSUED AT 641 PM CDT WED MAR 12 2014
A LOW PRESSURE TROUGH HAS MOVED THOUGH ALL BUT THE FAR EASTERN
PORTIONS OF CENTRAL NORTH DAKOTA. WIND HAS JUST SHIFTED WESTERLY
AT JAMESTOWN. WEST TO NORTHWEST WINDS GUSTING TO AROUND 30 MPH
ACROSS THE REMAINDER OF THE FORECAST AREA. EXPECT WINDS TO
DIMINISH WITHIN THE NEXT HOUR OR TWO. OTHERWISE MAINLY CLEAR SKIES
EXPECTED TONIGHT. MADE SOME MINOR ADJUSTMENTS TO SKY COVER GRIDS
TO ACCOUNT FOR CLOUDS MOVING OUT OF THE EASTERN CWA. ALSO SLOWED
THE DIURNAL DROP IN TEMPERATURES A BIT THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 405 PM CDT WED MAR 12 2014
BENIGN WEATHER WILL CONTINUE OVERNIGHT INTO THURSDAY WITH UPPER
RIDGING TO THE WEST AND MILD WESTERLY FLOW. HYDRO ISSUES CONTINUE
TO BE THE MAIN OPERATIONAL FOCUS AND A DETAILED DISCUSSION IS
INCLUDED BELOW.
EXPECT EVEN WARMER TEMPERATURES ON THURSDAY WITH HIGHS IN THE
LOWER 40S NORTH AND MID/UPPER 50S SOUTH. THERE IS A LOW
PROBABILITY OF A FEW SPRINKLES OR FLURRIES THURSDAY MORNING ACROSS
THE FAR NORTH AND HAVE OPTED NOT TO INCLUDE IN FORECAST GRIDS AT
THIS TIME.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 405 PM CDT WED MAR 12 2014
A BRIEF COOL DOWN ON SATURDAY FOLLOWED BY A RETURN TO NEAR TO
ABOVE NORMAL TEMPERATURES WILL HIGHLIGHT THE EXTENDED FORECAST.
THE 12 UTC DETERMINISTIC AND ENSEMBLE SUITE ARE IN GOOD AGREEMENT
ON A STRONG COLD FRONT PROPAGATING ACROSS NORTH DAKOTA THROUGH THE
DAY ON FRIDAY WITH A COLD 1037 MB SURFACE HIGH BUILDING INTO THE
NORTHERN PLAINS ON SATURDAY. AS A RESULT...HIGHS ON SATURDAY WILL
RANGE FROM AROUND 20 ACROSS THE TURTLE MOUNTAINS TO THE UPPER 30S
FAR SOUTHWEST. THERE IS SOME UNCERTAINTY ON HOW FAR EAST
PRECIPITATION ASSOCIATED WITH THE LOW LEVEL BAROCLINIC ZONE ON THE
WESTERN PERIPHERY OF THE HIGH WILL BE ABLE TO DEVELOP WITH DRY
EASTERLY FLOW FROM THE HIGH. FOR NOW...FOLLOWED THE 12 UTC
GFS/ECMWF WHICH KEEP THE PRECIPITATION FURTHEST WEST. RETURN
FLOW IS EXPECTED TO COMMENCE ON SUNDAY WITH A WARMING TREND
BENEATH A BROAD UPPER LEVEL RIDGE INTO MONDAY. THE MODELS DO BEGIN
TO DIVERGE A BIT TUESDAY ONWARD IN REGARDS TO THE POTENTIAL BREAK
DOWN OF THE RIDGE MID NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1245 AM CDT THU MAR 13 2014
VFR CIGS/VSBYS THROUGH THE TAF PERIOD. A COLD FRONT WILL PASS
THROUGH THE NORTHERN TERMINALS...KMOT/KISN IN THE MORNING BETWEEN
12Z AND 15Z THURSDAY...AND BETWEEN 18Z AND 21Z THURSDAY FOR
KDIK/KBIS/KJMS. EXPECTING SCT MID LEVEL CLOUDS WITH WINDS SHIFTING
TO THE NORTHWEST BETWEEN 15KT AND 30KT.
&&
.HYDROLOGY...
ISSUED AT 1245 AM CDT THU MAR 13 2014
MULTIPLE FLOOD HEADLINES REMAIN IN EFFECT ACROSS THE MISSOURI
BASIN AS ICE CONTINUES TO CONTRIBUTE TO PROBLEMATIC HIGH WATER ON
MANY AREA RIVERS AND STREAMS.
THIS INCLUDES BEAVER CREEK NEAR LINTON...CANNONBALL RIVER...CEDAR
CREEK...HEART RIVER...LITTLE MISSOURI RIVER AND THE MISSOURI RIVER
ABOVE LAKE SAKAKAWEA. ELEVATED AND FLUCTUATING WATER LEVELS ARE
LIKELY TO CONTINUE UNTIL THE CHANNELS BECOME ICE FREE. THE LACK OF
ADDITIONAL FORECAST PRECIPITATION TO INCREASE FLOWS AND MOVE THE
ICE DOWNSTREAM SUGGESTS ICE IMPACTS COULD BE PROLONGED INTO THE
WEEKEND FOR SOME LOCATIONS.
THE MISSOURI RIVER IN THE BISMARCK/MANDAN VICINITY WILL HAVE TO
BE CLOSELY MONITORED OVER THE COMING DAYS FOR ICE JAM POTENTIAL AS
SIGNIFICANT AMOUNTS OF LOCAL ICE REMAINS IN THE CHANNEL...WITH
ADDITIONAL ICE CONTRIBUTIONS FROM THE HEART AND KNIFE RIVERS.
RUNOFF IS ALSO LIKELY TO INCREASE ACROSS THE SOURIS
BASIN...HOWEVER...INITIAL INDICATIONS ARE THAT SLIGHTLY DRIER
SOILS ARE ALLOWING FOR GREATER INFILTRATION.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM ...RP KINNEY
LONG TERM/HYDROLOGY...AYD/KS
AVIATION...KS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
340 AM CDT THU MAR 13 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM CDT THU MAR 13 2014
AT 3 AM...A WARM FRONT WAS LOCATED OVER WESTERN MINNESOTA.
THE COMBINATION OF 280 TO 290K ISENTROPIC LIFT AND STRONG 900 TO
800 MB FRONTOGENETIC LIFT WAS PRODUCING A 6 TO 8K DECK OF CLOUDS
ALONG AND WEST OF THE INTERSTATE 35 CORRIDOR. THERE WERE EVEN A
FEW REPORTS OF 2K FOOT CLOUDS BRIEFLY AT MASON CITY. THESE CLOUDS
WERE HELPING TO RISE TEMPERATURES INTO THE LOWER AND MID 30S.
MEANWHILE WHERE SKIES WERE STILL CLEAR...TEMPERATURES RANGE FROM
THE SINGLE DIGITS TO MID TEENS.
TODAY - THE WARM FRONT WILL MOVE EAST ACROSS THE FORECAST AREA.
AT MOST LOCATIONS...THE NAM AND GFS SOUNDINGS BECOME VERY
SATURATED BELOW 900 MB LATE THIS MORNING AND AFTERNOON. MEANWHILE
BOTH THE RAP HAS THIS LAYER DRY. NORMALLY...THE GFS AND NAM HAVE
PROBLEMS IN THIS SYNOPTIC SITUATION WHERE YOU HAVE STRONG WARM
AIR ADVECTION GOING UP AN OVER A SNOW PACK. WHILE THIS CAN
OCCUR...A SIMILAR SIGNAL IS SHOWING UP IN THE BUFKIT SOUNDINGS AT
BOTH FAIRMONT AND REDWOOD FALLS AND NEITHER LOCATION HAS ANY LOW
CLOUDS. DUE TO THE LOW LEVELS BEING DRIER THAN EXPECTED REMOVED
THE MENTION OF FREEZING DRIZZLE AND SNOW FOR MUCH OF THE AREA THIS
MORNING. THE ONLY PLACE THAT A MENTION OF FLURRIES WAS KEPT IN WAS
OVER IN CENTRAL WISCONSIN WHERE THE ARW HINTS THAT THERE MAY BE
SOME VERY LIGHT PRECIPITATION AROUND 13.15Z.
TONIGHT - THE 13.00Z MODELS ARE IN GOOD AGREEMENT THAT A SHORT
WAVE TROUGH AND COLD FRONT WILL MOVE SOUTHEAST THROUGH THE
REGION. THE AIR MASS AHEAD OF THIS FRONT IS VERY DRY DUE TO
THE DOWN SLOPED AIR BEING BROUGHT INTO THE AREA FROM THE NORTHERN
PLAINS. AS A RESULT...ONLY EXPECT SOME CLOUDS ASSOCIATED WITH
THIS SYSTEM.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 339 AM CDT THU MAR 13 2014
FROM FRIDAY INTO FRIDAY EVENING...THE 13.00Z MODELS ARE IN GOOD
AGREEMENT THAT A SECONDARY FRONT WILL REMAIN STATIONARY OVER
NORTHERN MINNESOTA AND NORTHERN WISCONSIN. AT THE SAME TIME...A
SERIES OF WEAK SHORT WAVES WILL BE MOVING ALONG THIS BOUNDARY. THE
COLD FRONT LOOKS CLOSE ENOUGH TO CLARK AND TAYLOR COUNTIES TO
WARRANT A SLIGHT CHANCE OF SNOW.
ON SATURDAY AND SATURDAY NIGHT...THE COLD FRONT WILL MOVE SOUTH
THROUGH THE FORECAST AREA. THE GFS HAS THE STRONGEST COLD AIR
ADVECTION IN THE WAKE OF THIS FRONT. MEANWHILE THE NAM HAS THE
WEAKEST COLD AIR ADVECTION. THE ECMWF WAS A NICE COMPROMISE
BETWEEN THE TWO...SO TRENDED TOWARD IT FOR TEMPERATURES. THERE
LOOKS TO BE ENOUGH LIFT AND MOISTURE NORTH OF INTERSTATE 94 FOR
A MENTION OF SOME LIGHT SNOW. MEANWHILE DURING THE AFTERNOON AND
EVENING...BOTH THE NAM AND ECMWF SUGGEST SOME WEAK TO MODERATE
CYCLOGENESIS TAKING PLACE ACROSS WESTERN AND SOUTHERN IOWA. THE
285 AND 290K ISENTROPIC SURFACES BECOME SATURATED ENOUGH TO
SUGGEST THE POSSIBILITY THAT A BAND OF SNOW COULD DEVELOP EITHER
ON THE INTERSTATE 90 CORRIDOR /ECMWF/ OR ACROSS NORTHEAST IOWA AND
SOUTHWEST WISCONSIN /GFS...GEM...AND NAM/. SINCE THIS IS A
RELATIVELY NEW DEVELOPMENT IN THE MODELS...OPTED TO GO WITH THE
BETTER SNOW CHANCES IN AREAS WHERE THERE WAS THE BEST MODEL
CONSENSUS.
FROM SUNDAY NIGHT INTO TUESDAY...THE MODELS CONTINUE TO STRUGGLE
ON TRACK AND TIMING OF A SERIES OF SYSTEMS MOVING THROUGH THE
REGION. SINCE THERE HAS BEEN VERY LITTLE RUN TO RUN
CONSISTENCY...JUST STAYED WITH THE MODEL CONSENSUS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1001 PM CDT WED MAR 12 2014
FOCUS CONTINUES TO BE ON A WARM FRONT NEARING WESTERN MINNESOTA
MARCHING EASTWARD. EXPECT CLOUDS TO INCREASE WITH CEILINGS
LOWERING AS THIS FRONT APPROACHES THE TAF SITES. A 4 HOUR PERIOD
BETWEEN 10-16Z OF MVFR CEILINGS REMAINS LIKELY. ANY PRECIPITATION
THAT SHOULD FALL FROM THESE CLOUDS LOOKS TO WAIT UNTIL AFTER 12Z
AND OCCUR EAST OF LSE. CLOUDS SHOULD SCATTER/CLEAR OUT DURING THE
LATE MORNING AND AFTERNOON HOURS WITH THE WARM FRONTAL PASSAGE.
SOUTH TO SOUTHWEST WINDS WILL PICK UP AS WELL...PERHAPS GUSTING 15
TO 20 KT BY LATE IN THE DAY AT RST. EXPECT THE GUSTS TO DIMINISH
DURING THE EVENING AT RST AS NOCTURNAL COOLING SETS IN...THOUGH A
10-15 KT SUSTAINED BREEZE IS LIKELY TO CONTINUE. MEANWHILE...AT
LSE...NOCTURNAL COOLING DIMINISHING WINDS IN THE VALLEY WILL
COMBINE WITH STRONGER WINDS ABOVE THE SURFACE TO PRODUCE LOW LEVEL
WIND SHEAR AFTER 03Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1020 AM EDT THU MAR 13 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 340 AM EDT THU MAR 13 2014
THE TRANSITIONAL PATTERN WILL CONTINUE TO CREATE WIDE
SWINGS IN THE WEATHER THROUGH THE FORECAST PERIOD. TODAY
TEMPERATURES WILL RUN SEVERAL DEGREES BELOW NORMAL IN THE WAKE OF
YESTERDAYS COLD FRONTAL PASSAGE. HIGH PRESSURE SLIDING TO THE EAST
WILL ALLOW WARM TEMPERATURES TO RETURN FOR FRIDAY BUT THE
DEVELOPMENT OF ANOTHER UPPER RIDGE WEST/UPPER TROUGH EAST PATTERN
SETS UP...BRINGING SPORADIC LOW CHANCES FOR PRECIPITATION AS WELL AS
TEMPERATURES SWINGING FROM WELL BELOW NORMAL TO NEAR/JUST ABOVE
NORMAL NEARLY DAILY THROUGH THE PERIOD.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1005 AM EDT THU MAR 13 2014
SATELLITE INDICATED MOSTLY CLEAR SKIES ACROSS OUR REGION...WHILE AN
AREA OF CLOUDS OVER NORTHWEST ILLINOIS WAS EXPANDING VERY SLOWLY
EASTWARD. AT THE PRESENT RATE OF MOVEMENT IT WILL BE HARD PRESSED TO
REACH OUR FAR NORTHWEST BY 18Z...SO WILL BACK OFF ON SKY COVER A
LITTLE KEEPING MOST AREAS MOSTLY SUNNY WELL INTO THIS AFTERNOON. THE
MODELS INDICATE NORTHERN SECTIONS MAY BECOME PARTLY CLOUDY THIS
AFTERNOON AND WILL STILL INDICATE THIS SOMEWHAT...BUT LESS CLOUDS
THAN THE PREVIOUS FORECAST.
CONCERNING TEMPERATURES...WARM ADVECTION WILL BE INCREASING THIS
AFTERNOON AS SURFACE RIDGE OVER OUR AREA MOVES EASTWARD. GIVEN MARCH
SUN AND THAT RAP SURFACE TEMPERATURES ARE A LITTLE WARMER WILL RAISE
HIGHS MOST AREAS A DEGREE OR TWO LATER TODAY. THERE WILL BE A SHARP
TEMPERATURE GRADIENT TODAY WITH HIGHS RANGING FROM THE LOWER 30S
RANDOLPH COUNTY TO THE MID AND UPPER 40S FAR SOUTHWEST.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 340 AM EDT THU MAR 13 2014
HIGH PRESSURE SLIDES TO THE EAST TONIGHT AND WARM ADVECTION GETS
GOING. TEMPERATURES WILL LIKELY DROP A BIT EARLY BUT THEN STEADY OUT
AND EVEN START TO CLIMB BY MORNING. FRIDAY WITH WARM ADVECTION AND
UPPER RIDGING IN PLACE EXPECT TO SEE SIGNIFICANT WARMING AND WENT
WITH THE WARMER MAV NUMBERS FOR HIGHS IN THE MID 50S TO LOWER 60S.
FRIDAY NIGHT A COLD FRONT WILL MOVE THROUGH THE AREA. FRIDAY NIGHT/S
FRONTAL PASSAGE IS LOOKING DRIER THIS SET OF MODEL RUNS...WITH NAM
AND GFS NO LONGER CARRYING ANY QPF ACROSS THE FORECAST AREA.
OPERATIONAL GFS SHOWING VIRTUALLY NO FORCING WITH THE WASHED OUT
FRONT AND Q VECTOR DIVERGENCE ALOFT IMPLYING SOME SINKING MOTION.
MOS NUMBERS ARE NOW DRY FOR MAV AND MET AS WELL. HOWEVER...ENSEMBLES
ARE STILL SHOWING SOME VARIABILITY AND ENSEMBLE MOS NUMBERS ARE
SHOWING ANYWHERE FROM DRY TO HIGH CHANCE POPS. WITH THAT KIND OF
VARIABILITY PREFER NOT TO GO TOTALLY DRY AND KEEP A SLIGHT CHANCE
GOING ACROSS THE EASTERN COUNTIES FOR NOW. THERMAL PROFILES ARE WARM
ENOUGH FOR PRECIP TO BE RAIN SHOULD IT OCCUR.
SATURDAY FAIRLY NEUTRAL ADVECTION WILL BE IN PLACE BUT 850 MB
TEMPERATURES DON/T CLIMB MUCH ABOVE ZERO. WITH PARTLY CLOUDY SKIES
AND TEMPERATURES ALOFT SEVERAL DEGREES COOLER THAN FRIDAY WENT WITH
THE COOLER MET NUMBERS FOR SATURDAY HIGHS IN THE MID 40S TO UPPER
50S.
SATURDAY NIGHT MODELS ARE STARTING TO KEY IN ON A WARM FRONT FORMING
SOUTH OF THE AREA. THIS COULD BRING IN RAIN TO THE SOUTHERN COUNTIES
LATE AND WENT WITH POPS BETWEEN THE MAV AND MET.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY NIGHT/...
ISSUED AT 351 AM EDT THU MAR 13 2014
MODELS CONTINUE TO SHOW INCONSISTENCIES THROUGH THE LONG TERM
PERIOD. LATEST INITIALIZATION SEEMS TO FAVOR THE WETTER EURO
THOUGH BY KEEPING PRECIP CHANCES OVER THE SOUTHERN PORTIONS OF THE
FORECAST AREA ON SUNDAY AS A LOW PASSES OVER THE DEEP SOUTH. AFTER
DRY CONDITIONS ON MONDAY...THE PATTERN BECOMES A TAD MORE ACTIVE
AROUND MID-WEEK WITH A BROAD UPPER LOW BRINGING PRECIP CHANCES FOR
TUESDAY AND WEDNESDAY. RAIN WILL BE THE PREDOMINANT PRECIP TYPE.
MEANWHILE...THE WARM SECTOR OF A SURFACE LOW WILL RESULT IN HIGH
TEMPS TOPPING OFF IN THE UPPER 50S BY THE SECOND HALF OF THE
EXTENDED PERIOD.
&&
.AVIATION /DISCUSSION FOR THE 131500Z KIND TAF UPDATE/...
ISSUED AT 1020 AM EDT THU MAR 13 2014
SURFACE RIDGE EXPECTED TO PASS OFF TO THE EAST OF KIND OVER THE NEXT
FEW HOURS...RESULTING IN SURFACE WINDS BECOMING 190-220 DEGREES. NO
SIGNIFICANT CHANGES MADE TO THE FORECAST AT THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.
VFR CONDITIONS WILL PREVAIL FOR DURATION OF TAF PERIOD WITH STRONG
SUBSIDENCE IN PLACE. WARM AIR ADVECTION WILL RESULT IN AN INCREASE
IN MID AND HIGH CLOUDS THIS AFTERNOON...BUT NOTHING THAT WILL
AFFECT FLIGHT CONDITIONS. THERE WILL BE A WIND SHIFT THIS MORNING
TO THE SOUTHWEST AND A GRADUAL INCREASE IN SPEEDS THROUGH THE
COURSE OF TAF PERIOD. SUSTAINED SPEEDS WILL INCREASE TO 22 KTS AT
KIND BY END OF THIS TAF PERIOD.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...JH
SHORT TERM...CP
LONG TERM....TDUD
AVIATION...TDUD/JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1005 AM EDT THU MAR 13 2014
.UPDATE...
NEAR TERM FOR THE REST OF TODAY HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 340 AM EDT THU MAR 13 2014
THE TRANSITIONAL PATTERN WILL CONTINUE TO CREATE WIDE
SWINGS IN THE WEATHER THROUGH THE FORECAST PERIOD. TODAY
TEMPERATURES WILL RUN SEVERAL DEGREES BELOW NORMAL IN THE WAKE OF
YESTERDAYS COLD FRONTAL PASSAGE. HIGH PRESSURE SLIDING TO THE EAST
WILL ALLOW WARM TEMPERATURES TO RETURN FOR FRIDAY BUT THE
DEVELOPMENT OF ANOTHER UPPER RIDGE WEST/UPPER TROUGH EAST PATTERN
SETS UP...BRINGING SPORADIC LOW CHANCES FOR PRECIPITATION AS WELL AS
TEMPERATURES SWINGING FROM WELL BELOW NORMAL TO NEAR/JUST ABOVE
NORMAL NEARLY DAILY THROUGH THE PERIOD.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1005 AM EDT THU MAR 13 2014
SATELLITE INDICATED MOSTLY CLEAR SKIES ACROSS OUR REGION...WHILE AN
AREA OF CLOUDS OVER NORTHWEST ILLINOIS WAS EXPANDING VERY SLOWLY
EASTWARD. AT THE PRESENT RATE OF MOVEMENT IT WILL BE HARD PRESSED TO
REACH OUR FAR NORTHWEST BY 18Z...SO WILL BACK OFF ON SKY COVER A
LITTLE KEEPING MOST AREAS MOSTLY SUNNY WELL INTO THIS AFTERNOON. THE
MODELS INDICATE NORTHERN SECTIONS MAY BECOME PARTLY CLOUDY THIS
AFTERNOON AND WILL STILL INDICATE THIS SOMEWHAT...BUT LESS CLOUDS
THAN THE PREVIOUS FORECAST.
CONCERNING TEMPERATURES...WARM ADVECTION WILL BE INCREASING THIS
AFTERNOON AS SURFACE RIDGE OVER OUR AREA MOVES EASTWARD. GIVEN MARCH
SUN AND THAT RAP SURFACE TEMPERATURES ARE A LITTLE WARMER WILL RAISE
HIGHS MOST AREAS A DEGREE OR TWO LATER TODAY. THERE WILL BE A SHARP
TEMPERATURE GRADIENT TODAY WITH HIGHS RANGING FROM THE LOWER 30S
RANDOLPH COUNTY TO THE MID AND UPPER 40S FAR SOUTHWEST.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 340 AM EDT THU MAR 13 2014
HIGH PRESSURE SLIDES TO THE EAST TONIGHT AND WARM ADVECTION GETS
GOING. TEMPERATURES WILL LIKELY DROP A BIT EARLY BUT THEN STEADY OUT
AND EVEN START TO CLIMB BY MORNING. FRIDAY WITH WARM ADVECTION AND
UPPER RIDGING IN PLACE EXPECT TO SEE SIGNIFICANT WARMING AND WENT
WITH THE WARMER MAV NUMBERS FOR HIGHS IN THE MID 50S TO LOWER 60S.
FRIDAY NIGHT A COLD FRONT WILL MOVE THROUGH THE AREA. FRIDAY NIGHT/S
FRONTAL PASSAGE IS LOOKING DRIER THIS SET OF MODEL RUNS...WITH NAM
AND GFS NO LONGER CARRYING ANY QPF ACROSS THE FORECAST AREA.
OPERATIONAL GFS SHOWING VIRTUALLY NO FORCING WITH THE WASHED OUT
FRONT AND Q VECTOR DIVERGENCE ALOFT IMPLYING SOME SINKING MOTION.
MOS NUMBERS ARE NOW DRY FOR MAV AND MET AS WELL. HOWEVER...ENSEMBLES
ARE STILL SHOWING SOME VARIABILITY AND ENSEMBLE MOS NUMBERS ARE
SHOWING ANYWHERE FROM DRY TO HIGH CHANCE POPS. WITH THAT KIND OF
VARIABILITY PREFER NOT TO GO TOTALLY DRY AND KEEP A SLIGHT CHANCE
GOING ACROSS THE EASTERN COUNTIES FOR NOW. THERMAL PROFILES ARE WARM
ENOUGH FOR PRECIP TO BE RAIN SHOULD IT OCCUR.
SATURDAY FAIRLY NEUTRAL ADVECTION WILL BE IN PLACE BUT 850 MB
TEMPERATURES DON/T CLIMB MUCH ABOVE ZERO. WITH PARTLY CLOUDY SKIES
AND TEMPERATURES ALOFT SEVERAL DEGREES COOLER THAN FRIDAY WENT WITH
THE COOLER MET NUMBERS FOR SATURDAY HIGHS IN THE MID 40S TO UPPER
50S.
SATURDAY NIGHT MODELS ARE STARTING TO KEY IN ON A WARM FRONT FORMING
SOUTH OF THE AREA. THIS COULD BRING IN RAIN TO THE SOUTHERN COUNTIES
LATE AND WENT WITH POPS BETWEEN THE MAV AND MET.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY NIGHT/...
ISSUED AT 351 AM EDT THU MAR 13 2014
MODELS CONTINUE TO SHOW INCONSISTENCIES THROUGH THE LONG TERM
PERIOD. LATEST INITIALIZATION SEEMS TO FAVOR THE WETTER EURO
THOUGH BY KEEPING PRECIP CHANCES OVER THE SOUTHERN PORTIONS OF THE
FORECAST AREA ON SUNDAY AS A LOW PASSES OVER THE DEEP SOUTH. AFTER
DRY CONDITIONS ON MONDAY...THE PATTERN BECOMES A TAD MORE ACTIVE
AROUND MID-WEEK WITH A BROAD UPPER LOW BRINGING PRECIP CHANCES FOR
TUESDAY AND WEDNESDAY. RAIN WILL BE THE PREDOMINANT PRECIP TYPE.
MEANWHILE...THE WARM SECTOR OF A SURFACE LOW WILL RESULT IN HIGH
TEMPS TOPPING OFF IN THE UPPER 50S BY THE SECOND HALF OF THE
EXTENDED PERIOD.
&&
.AVIATION /DISCUSSION FOR THE 13/1200Z TAF ISSUANCE/...
ISSUED AT 714 AM EDT THU MAR 13 2014
VFR CONDITIONS WILL PREVAIL FOR DURATION OF TAF PERIOD WITH STRONG
SUBSIDENCE IN PLACE. WARM AIR ADVECTION WILL RESULT IN AN INCREASE
IN MID AND HIGH CLOUDS THIS AFTERNOON...BUT NOTHING THAT WILL
AFFECT FLIGHT CONDITIONS. THERE WILL BE A WIND SHIFT THIS MORNING
TO THE SOUTHWEST AND A GRADUAL INCREASE IN SPEEDS THROUGH THE
COURSE OF TAF PERIOD. SUSTAINED SPEEDS WILL INCREASE TO 22 KTS AT
KIND BY END OF THIS TAF PERIOD.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...JH
SHORT TERM...CP
LONG TERM....TDUD
AVIATION...TDUD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
549 AM CDT THU MAR 13 2014
.UPDATED FOR 12Z AVIATION DISCUSSION...
ISSUED AT 531 AM CDT THU MAR 13 2014
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 332 AM CDT THU MAR 13 2014
MAIN ITEM OF INTEREST IN THE SHORT TERM IS THE HIGH TEMPERATURE
FORECAST THIS AFTERNOON. EARLY MORNING WATER VAPOR IMAGERY TOGETHER
WITH 500MB HEIGHTS AND WINDS IDENTIFIED A SHORTWAVE JUST NORTH OF
THE IDAHO PANHANDLE...WITH ITS SURFACE REFLECTION LOCATED ACROSS
CENTRAL ALBERTA. OVER THE NEXT 24 HOURS THIS PV ANOMALY AND SURFACE
LOW WILL RACE EAST SOUTHEASTWARD AND SHOULD BE LOCATED SOMEWHERE
OVER LAKE SUPERIOR BY FRIDAY MORNING. AS THIS HAPPENS...THE THERMAL
RIDGE AHEAD OF THIS WAVE WILL MOVE ACROSS THE UPPER MIDWEST THIS
AFTERNOON...AND SOUTHWEST WINDS TOGETHER WITH CLEAR SKIES SHOULD
MAXIMIZE THE BOUNDARY LAYER HEATING POTENTIAL THIS AFTERNOON.
THEREFORE HAVE GONE ON THE HIGH END OF GUIDANCE FOR
TEMPERATURES...WITH A FEW 60S EXPECTED IN SOUTHWEST MN...MID TO
UPPER 40S ALONG THE MISSISSIPPI RIVER VALLEY...AND LOWER 40S IN
WESTERN WI. A TRAILING COLD FRONT WILL MOVE THROUGH THE REGION
THURSDAY NIGHT...SO HAVE INCREASED THE WINDS THROUGH FRIDAY MORNING.
FORECAST SOUNDINGS SHOW SOME BOUNDARY LAYER MOISTURE AND POTENTIAL
FOR DRIZZLE...BUT FEEL THE MOISTURE IS OVERDONE AND EXPECTING MORE
OF A LOW STRATUS SCENARIO THAN FALLING PRECIP.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 332 AM CDT THU MAR 13 2014
CONFIDENCE THROUGHOUT THE LONG TERM IS BELOW AVERAGE...
PARTICULARLY IN THE LATER PERIODS. THE MODEL SPREAD IS UNUSUALLY
LARGE DUE IN PART TO THE COMPLICATED FLOW PATTERN AND SUBTLE
DIFFERENCES IN IT THAT PLAY A BIG ROLE IN HOW THINGS DEVELOP
DOWNSTREAM. FOR THE MOST PART...THESE DISTURBANCES ARE FAIRLY
WEAK WHICH SHOULD MITIGATE CONSIDERABLE MODEL JUMPS. HOWEVER...A
MORE SIGNIFICANT SYSTEM MAY BE EMERGING SOMETIME EARLY TO MID NEXT
WEEK AS THE FLOW SHIFTS TO MORE OF A WSW-SW REGIME. GIVEN THE
CURRENT SET OF MODEL SOLUTIONS...IT WILL PROBABLY TAKE SEVERAL
MORE RUNS BEFORE WE BEGIN TO SEE CONVERGENCE TOWARD A COMMON
SOLUTION.
MORE SPECIFICALLY...SEVERAL POTENTIAL PRECIP MAKERS WILL BE
TRAVERSING THE MPX CWA IN THE LONG TERM BEGINNING FRIDAY. CAA
ALLOWING FOR STEEP LOW LEVEL LAPSE RATES WILL BRING AN OPPORTUNITY
FOR SPRINKLES OR FLURRIES ACROSS CENTRAL MN AND NWRN WI THROUGH
AFTERNOON. MOST OF THE PROFILE IS ABOVE -15C...SO THINKING MORE
SPRINKLES THAN FLURRIES. MODELS ALSO TEND TO OVERDO THE DEPTH OF
MOISTURE IN THESE SCENARIOS...SO DO NOT THINK CHANCES OF ANYTHING
MEASURABLE ARE IMPRESSIVE.
ANOTHER QUICK-MOVING DISTURBANCE WILL SLIDE SOUTHEAST ACROSS
SOUTHWESTERN MN FRIDAY NIGHT/SATURDAY AND COULD BRING SOME LIGHT
SNOW TO THESE AREAS. THIS TOO WILL BRING LITTLE OR NO ACCUMULATION.
A STRONGER SYSTEM OVER SOUTHERN CANADA WILL PUSH A WARM FRONT
EASTWARD SUNDAY NIGHT/MONDAY AND COULD PRODUCE A BIT OF LIGHT
SNOW. GFS IS PRETTY BULLISH WITH QPF WHEREAS ECMWF AND GEM ARE
MORE SUBDUED. PREFER THE MORE SUBDUED SOLUTION WITH THE GULF OF
MEXICO CUT OFF.
BY EARLY NEXT WEEK...THE EVOLUTION OF THE ECMWF IS CONSIDERABLY
SLOWER THAN THE GFS. THIS ALLOWS FOR A MORE WESTERLY TRACKED...
DEEPER SYSTEM TO EMERGE OVER THE MIDWEST TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 531 AM CDT THU MAR 13 2014
MVFR/IFR CEILINGS ARE DEVELOPING ALONG THE WARM FRONT IN NORTH
CENTRAL MN AND COULD AFFECT AXN/STC THIS MORNING. FOR NOW JUST
HAVE SCT CIGS...BUT MAY HAVE TO AMEND FOR BKN IF THEY CONTINUE TO
DEVELOP TO THE SOUTHWEST. BOTH THE NAM AND RAP INDICATE LOW LEVEL
MOISTURE SURGING ACROSS THE REGION LATER TONIGHT AS A COLD FRONT
SWEEPS THROUGH. AGAIN HANDLED THIS WITH A SCT GROUP...BUT COULD
SEE MVFR CIGS.
KMSP...
AT THIS TIME FEEL THAT THE STRATUS WILL REMAIN NORTH OF MSP
TODAY WITH VFR CONDITIONS THROUGHOUT. WSW WINDS GUST 15-20KTS AT
TIMES THIS AFTERNOON. WILL HAVE TO WATCH THE TRENDS WITH THE POST
FRONTAL CEILINGS COMING DOWN LATER TONIGHT.
/OUTLOOK FOR KMSP/
SAT...VFR. WINDS NNE AT 5-10KTS.
SUN...VFR. WINDS E AT 5-10KTS.
MON...VFR. WINDS N AT 05KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...BORGHOFF
AVIATION...JRB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
622 AM CDT THU MAR 13 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 436 AM CDT THU MAR 13 2014
FROM A STRICTLY TEMPERATURE/SKY COVER STANDPOINT...TODAY IS GOING
TO BE ANOTHER SPRING-FEVER SETUP WITH HIGHS CLIMBING RIGHT UP TO
AROUND 70 DEGREES IN ALL AREAS UNDER ESSENTIALLY WALL-TO-WALL
SUNSHINE. HOWEVER...FOR THOSE WITH POTENTIAL CONCERNS OF ENHANCED
FIRE DANGER THIS IS REALLY THE ONLY FLY IN THE OINTMENT...AND IN FACT
CONDITIONS HAVE BEEN DEEMED SEVERE ENOUGH TO JUSTIFY A CWA-WIDE
RED FLAG WARNING FOR THIS AFTERNOON. PLEASE REFER TO THE SEPARATE
FIRE SECTION BELOW FOR MUCH MORE DETAIL ON THESE ISSUES.
STARTING OFF WITH THE HERE AND NOW...11-3.9 MICRON SATELLITE
IMAGERY CONFIRMS THAT THERE ARE VIRTUALLY NO CLOUDS
TO SPEAK OF WHATSOEVER EARLY THIS MORNING...NOT ONLY WITHIN THE CWA
BUT ALSO EXTENDING SEVERAL HUNDRED MILES IN NEARLY ALL DIRECTIONS.
WATER VAPOR SATELLITE IMAGERY AND SHORT TERM MODEL DATA DEPICT THE
LOCAL AREA TO BE UNDER THE INFLUENCE OF DRY NORTHWESTERLY
FLOW/SUBTLE SHORTWAVE RIDGING OF A RIDGE AXIS CENTERED FROM
WYOMING-ONTARIO. MEANWHILE...A NEARLY STALLED-OUT MID LEVEL CLOSED
LOW CONTINUES CHURNING OVER SOUTHERN CA/NV. PUT ANOTHER WAY...THE
CENTRAL PLAINS IS UNDER AN UPPER LEVEL WIND MINIMUM IN BETWEEN THE
PRIMARY SPLIT UPPER JET STREAMS...WITH THE NORTHERN BRANCH
EXTENDING ACROSS THE CANADIAN BORDER AREA AND THEN SOUTHWARD
ACROSS THE GREAT LAKES...WHILE THE SOUTHERN BRANCH SNAKES ACROSS
THE SOUTHERN TIER OF THE CONUS. AT THE SURFACE...A FAIRLY WEAK
PRESSURE GRADIENT REGIME IS IN PLACE ACROSS THE AREA...WITH THE
CENTRAL PLAINS GENERALLY POSITIONED BETWEEN A TX RIDGE AXIS...AND
A LOW PRESSURE SYSTEM CENTERED WAY TO THE NORTH OVER SOUTH CENTRAL
CANADA. AS A RESULT...THE GENERAL PREVAILING BREEZE EARLY THIS
MORNING IS SOME VARIATION OF WESTERLY WITH SPEEDS ONLY 5-10 MPH.
DESPITE THESE LIGHT WESTERLY BREEZES...THE PRESENCE OF CLEAR SKIES
AND DRY AIR HAS ALLOWED A FAIRLY EFFICIENT TEMPERATURE DROP...AND
CURRENTLY HAVE MORNING LOW TEMPERATURES AIMED INTO THE 25-28 RANGE
ACROSS MOST OF THE AREA.
GETTING INTO THE DAYTIME HOURS TODAY...THE MID/UPPER LEVEL SCENE
INVOLVES A CONTINUATION OF THE AREA REMAINING IN BETWEEN THE
PRIMARY JET AXES...ALTHOUGH SLOWLY BUT SURELY FLOW WILL TRANSITION
FROM MORE NORTHWESTERLY TO MORE QUASI-ZONAL AS BOTH BRANCHES OF
THE JET SEND LOW AMPLITUDE SHORTWAVE TROUGHS EASTWARD AND
SOUTHEASTWARD TOWARD THE CENTRAL PLAINS. DESPITE THIS...BOTH
FORECAST SOUNDINGS AND PLAN-VIEW RELATIVE HUMIDITY PROGS SHOW A
REMARKABLY DRY DEEP-LAYER AIRMASS...AND OTHER THAN MAYBE A VERY
LIMITED COVERAGE OF THIN HIGH CIRRUS THIS AFTERNOON...WIDESPREAD
SUNSHINE IS DEFINITELY IN STORE. AT THE SURFACE...THE PRESSURE
GRADIENT WILL SHARPEN UP A BIT AS THE DAY GOES ON...IN RESPONSE TO
THE AFOREMENTIONED SOUTHERN CANADA LOW PRESSURE SYSTEM MIGRATING
DOWN TO NEAR THE NORTHERN TIP OF MN BY LATE AFTERNOON/EARLY
EVENING. AS THIS OCCURS...A TRAILING TROUGH AXIS WILL SHARPEN FROM
THE DAKOTAS SOUTH-SOUTHWESTWARD INTO EASTERN CO...OR GENERALLY
REMAINING JUST WEST OF THE CWA. WITHIN THIS PRESSURE FIELD...A
COUPLE OF MODEST LOWER-LEVEL WIND MAXIMUMS EVIDENT AT 850
MILLIBARS WILL SET UP...ONE MORE SOUTHWESTERLY AND EXTENDING FROM
SOUTH CENTRAL KS TO SOUTHEAST NEB...AND THE OTHER MORE WESTERLY
AND EXTENDING WEST-EAST ACROSS CENTRAL NEB. THANKS TO VERY DEEP
MIXING UP INTO THE 800-750MB LEVEL...IT WON/T TAKE MUCH TO
GENERATE SUSTAINED 15-20 MPH BREEZES WITH GUSTS TO AROUND 25 MPH
ACROSS MOST OF THE CWA FROM THE LATE-MORNING TO LATE-AFTERNOON
HOURS...WITH A BIT OF A LIGHTER WIND REGIME FOCUSING NEAR THE
SURFACE TROUGH AXIS IN THE FAR SOUTHWESTERN CWA...ESPECIALLY
AROUND FURNAS COUNTY. IN OTHER WORDS...IT WILL BE A BIT BREEZY
MUCH OF THE DAY BUT OVERLY WINDY. TEMP-WISE...AFTER HAVING DECENT
LUCK THE LAST FEW DAYS BLENDING THE 00Z NAM WITH A RECENT RAP13
RUN TO DERIVE HIGHS...TOOK THE SAME APPROACH FOR TODAY...WHICH
YIELDS GENERALLY A 1-3 DEGREE INCREASE IN MOST AREAS...NOW PUTTING
MOST PLACES SOMEWHERE IN THE 68-73 RANGE. IN CONTRAST...DEWPOINTS
WERE LOWERED SEVERAL DEGREES FROM PREVIOUS FORECAST...THUS PLAYING
INTO THE HIGH FIRE DANGER OUTLINED BELOW.
GETTING INTO THIS EVENING/TONIGHT BEYOND 00Z/7PM...THE PRIMARY
NORTHERN STREAM MOISTURE-STARVED MID LEVEL SHORTWAVE TROUGH WILL
SWING PRIMARILY ACROSS THE DAKOTAS-MN...AND ONLY GIVING THE LOCAL
AREA A GLANCING BLOW. DESPITE THIS DISTURBANCE MOVING
THROUGH...EXPECTING NO MORE THAN A SLIGHT INCREASE IN HIGH
CLOUDS...AND STILL AVERAGING MOSTLY CLEAR THROUGH THE NIGHT. THIS
DISTURBANCE WILL MAKE ITSELF A BIT MORE OBVIOUS DOWN AT THE
SURFACE...AS A MODEST COLD FRONT MAKES ITS WAY ACROSS THE CWA FROM
NORTHWEST-SOUTHEAST AS THE NIGHT GOES ON. INITIALLY BEFORE
MIDNIGHT...MOST PLACES WILL HOLD ONTO A WEST TO SOUTHWEST BREEZE
GENERALLY 5-15 MPH...BUT THEN AS THE FRONT MOVES THROUGH BREEZES
WILL SWITCH NORTHWESTERLY AT GENERALLY 10-15 MPH...WITH A BRIEF
PERIOD OF GUSTINESS TO AROUND 20 MPH LIKELY IN THE WAKE OF THIS
BOUNDARY...WHICH SHOULD CLEAR EVEN THE FAR SOUTHEAST CWA BY A FEW
HOURS BEFORE SUNRISE. TEMP-WISE...DESPITE DECENT MIXING BEHIND THE
PASSING COLD FRONT...THERE IS JUST ENOUGH LOW LEVEL COLD AIR
ADVECTION THAT WOULD EXPECT TO SEE A DECENT TEMPERATURE DROP
MAINLY LATE IN THE NIGHT/TOWARD SUNRISE FRIDAY MORNING. AS A
RESULT...ONLY TWEAKED PREVIOUS LOW TEMPS A FEW DEGREES MAINLY
DOWNWARD...WITH THE MAJORITY OF THE CWA AIMED INTO THE 31-35
RANGE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 436 AM CDT THU MAR 13 2014
GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC AND SREF-MEAN ALL
SUGGEST QUASI-ZONAL TO NORTHWESTERLY MID TO UPPER TROPOSPHERIC FLOW
WILL PERSIST OVER THE CENTRAL PLAINS DURING MUCH OF THE LONG TERM
FORECAST PERIOD. A MID-TROPOSPHERIC SHORT WAVE IS EXPECTED TO MOVE
ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY THURSDAY
NIGHT INTO FRIDAY...BUT ANY APPRECIABLE OMEGA IN ASSOCIATION THIS SHORT
WAVE SHOULD REMAIN WELL NORTHEAST OF OUR AREA. ANOTHER
MID-TROPOSPHERIC SHORT WAVE IS THEN EXPECTED TO MOVE EAST ACROSS THE
SOUTHERN PLAINS SATURDAY INTO SATURDAY NIGHT. A TRAILING
MID-TROPOSPHERIC PERTURBATION IS THEN EXPECTED TO MOVE SOUTHEAST
ACROSS THE CENTRAL HIGH PLAINS SATURDAY NIGHT INTO SUNDAY...WITH
THIS PERTURBATION EXPECTED TO EVENTUALLY MERGE WITH THE PRIMARY
MID-TROPOSPHERIC SHORT WAVE OVER THE SOUTHERN PLAINS DURING THE DAY
SUNDAY. AT THIS TIME IT APPEARS ANY APPRECIABLE OMEGA IN ASSOCIATION
WITH THE SHORT WAVE MOVING OVER THE SOUTHERN PLAINS WILL REMAIN WILL
SOUTH OF OUR AREA. WEAK OMEGA IN ASSOCIATION WITH TRAILING
PERTURBATION MAY BE JUST ENOUGH TO PROMOTE LIGHT PRECIPITATION ACROSS
PORTIONS OF OUR AREA SATURDAY NIGHT...A SOLUTION SUPPORTED BY QPF
FIELDS FROM NAM...EC AND SREF-MEAN. GIVEN THIS IS A QUICK-MOVING
CLIPPER WITH MODEST OMEGA AND QUESTIONABLE MID TO LOWER TROPOSPHERIC
MOISTURE...OPTED TO GO NO HIGHER THAN ~20% POPS ACROSS THE CWA
SATURDAY NIGHT. THAT BEING SAID...IT IS WORTH NOTING THAT THE NAM
AND SREF-MEAN BOTH SUGGEST THIS PERTURBATION WILL ACTUALLY STRENGTHEN
RATHER DRAMATICALLY OVER THE CENTRAL HIGH PLAINS...THUS RESULTING IN
AN AREA OF SURFACE CYCLOGENESIS OVER NORTHEASTERN NEBRASKA SUNDAY
NIGHT. ALTHOUGH THIS PERTURBATION...AND ASSOCIATED SURFACE LOW IF
REALIZED...ARE NOT EXPECTED TO LINGER NEAR THE AREA VERY LONG...BOTH
THE NAM AND SREF-MEAN SUGGEST THE INCREASING SOUTHEASTERLY LOWER
TROPOSPHERIC FLOW WILL RESULT IN A HEALTHY DOSE OF LOWER
TROPOSPHERIC THERMAL AND MOISTURE ADVECTION...WITH A BRIEF BUT
SUBSTANTIAL AXIS OF ISENTROPIC UPGLIDE NEAR THE 290K
SURFACE...RESEMBLING A TROWAL EXTENDING FROM SOUTHERN MISSOURI INTO
SOUTHEASTERN NEBRASKA AND THEN BACK INTO NORTH CENTRAL
KANSAS...LIKELY GRAZING OUR SOUTHEASTERN CWA. QPF FIELDS FROM
THE NAM RESPOND BY PRESENTING A BAND OF HEAVY PRECIPITATION OVER OUR
SOUTHEAST...WITH LIQUID PRECIPITATION AMOUNTS IN THE 0.25-0.50"
RANGE. CONTEMPLATED GOING WITH A HIGHER POP ACROSS OUR SOUTHEAST AS
A RESULT...BUT SINCE THE NAM AND SREF-MEAN ARE THE ONLY MODELS
SUGGESTING SUCH A SETUP...AND SINCE THE NAM IS THE ONLY MODEL
PRODUCING SUCH COPIOUS AMOUNTS OF PRECIPITATION...AND SINCE THE
OPERATIONAL GFS AND EC BOTH SUGGEST DRY CONDITIONS OR VERY LIGHT
PRECIPITATION ACROSS OUR SOUTHEAST...OPTED TO KEEP OUR SOUTHEAST IN
THE SAME ~20% POP BOAT AS THE REST OF THE CWA. CERTAINLY SOMETHING
TO MONITOR THROUGH THE NEXT FEW DAYS.
FORECAST PROXIMITY SOUNDINGS FROM THE ACROSS THE CWA...PER THE NAM
AND OPERATIONAL GFS...SUGGEST THE LOWER TROPOSPHERE WILL REMAIN WARM
ENOUGH FOR RAIN TO START SATURDAY NIGHT...BUT WILL EVENTUALLY COOL
TO SUPPORT SNOW PRODUCTION BY EARLY SUNDAY MORNING. GIVEN ALL
THIS..WENT AHEAD WITH A MIX OF RAIN AND SNOW IN THE OFFICIAL
FORECAST FOR SATURDAY NIGHT.
AS FOR THE REST OF THE LONG TERM FORECAST PERIOD...THERE ARE
INDICATIONS OF A LONGWAVE MID TROPOSPHERIC TROUGH SETTING UP OVER
THE WESTERN CONUS BY EARLY NEXT WEEK. MID TROPOSPHERIC THERMAL
ADVECTION...OR PERHAPS PERIODIC MID TROPOSPHERIC PERTURBATIONS
EJECTING FROM THE PRIMARY TROUGH AXIS...COULD PROMOTE JUST ENOUGH
OMEGA FOR PRECIPITATION PRODUCTION OVER THE AREA EARLY NEXT
WEEK...BUT AT THIS TIME THE PROBABILITY OF ACCURATELY PREDICTING
SUCH ACTIVITY IS TOO LOW TO JUSTIFY POPS. A DRY FORECAST HAS BEEN
PRESENTED SUNDAY AND BEYOND AS A RESULT.
LITTLE CHANGE IN THE LOWER TROPOSPHERIC AIR MASS SHOULD PROMOTE
AFTERNOON TEMPERATURE READINGS GENERALLY IN THE 50S AND 60S FRIDAY
AND SATURDAY. THE INTRUSION OF A COOLER LOWER TROPOSPHERIC AIR
MASS SHOULD THEN PROVIDE HIGHS IN THE 40S AND LOW 50S ON
SUNDAY...WITH HIGHS REBOUNDING INTO THE 50S AND 60S TO FINISH THE
FORECAST PERIOD. OVERNIGHT LOWS IN THE 20S AND 30S ARE EXPECTED FOR
THE MOST PART DURING THE LONG TERM FORECAST PERIOD.
&&
.AVIATION...(FOR THE 12Z KGRI TAF THROUGH 12Z FRIDAY MORNING)
ISSUED AT 620 AM CDT THU MAR 13 2014
CONFIDENCE REMAINS QUITE HIGH IN VFR CEILING/VISIBILITY THROUGH
THE NEXT 24 HOURS...AS THE AIRMASS THROUGH A DEEP LAYER OF THE
TROPOSPHERE REMAINS VERY DRY AND IN FACT SKIES SHOULD ESSENTIALLY
REMAIN CLEAR THE ENTIRE TIME WITH ONLY A FEW PASSING HIGH CLOUDS
MAINLY TONIGHT. AS FOR SURFACE WINDS...THERE WILL REALLY BE 3
DISTINCT REGIMES. STARTING OFF NOW THROUGH LATE MORNING...DIRECTION
WILL AVERAGE WESTERLY AT SPEEDS UNDER 10KT. THEN...THE LATE
MORNING THROUGH LATE AFTERNOON HOUR WILL FEATURE A DECENT UPSWING
IN WIND SPEEDS...BUT THIS TIME OUT OF THE SOUTHWEST WITH SUSTAINED
SPEEDS UP INTO THE 15-20KT RANGE AND GUST POTENTIAL AT LEAST
20-25KT. BY EARLY THIS EVENING...BREEZES WILL AGAIN DIE BACK DOWN
TO SUSTAINED VALUES AROUND 10KT...BUT THEN OVERNIGHT A COLD FRONT
WILL PASS THROUGH RESULTING IN A SWITCH TO NORTHWESTERLY BREEZES
SUSTAINED AROUND 12 KT MAINLY AFTER 06Z. ALTHOUGH NOT FORMALLY
INCLUDED IN THE TAF YET...AT LEAST A BRIEF PERIOD OF GUSTS 20+KT
COULD ACCOMPANY THIS FRONTAL PASSAGE.
&&
.FIRE WEATHER...
ISSUED AT 436 AM CDT THU MAR 13 2014
AS HAS BEEN ADVERTISED FOR A FEW DAYS NOW...TODAY CONTINUES TO
LOOK MORE AND MORE LIKE THE OVERALL-WORST DAY THIS WEEK FOR FIRE
DANGER ACROSS THE AREA (SINCE SUNDAY OF COURSE)...AND AS A RESULT
A CWA-WIDE RED FLAG WARNING HAS BEEN ISSUED FOR THIS AFTERNOON
THROUGH 00Z/7PM. BEFORE GOING ON...WANT TO BRIEFLY REMIND THAT
FOR OUR CWA CRITICAL FIRE THRESHOLDS ARE THE OVERLAP OF SUSTAINED
WINDS AND/OR GUSTS OF 20/25 MPH AND RELATIVE HUMIDITY (RH) OF 20
PERCENT OR LESS FOR 3+ HOURS...IN THE PRESENCE OF VERY DRY
VEGETATION (FUELS).
IN TODAY/S CASE...ITS REALLY THE LOW RH COMPONENT OF THE EQUATION
THAT HAS TIPPED THE SCALES TOWARD RED FLAG WARNING
ISSUANCE...WITH WIND SPEEDS LOOKING A BIT MORE MARGINAL. AS A
RESULT OF BUMPING UP HIGH TEMPERATURES A FEW DEGREES AND ALSO
LOWERING AFTERNOON DEWPOINTS AT LEAST A FEW DEGREES...WIDESPREAD
RH VALUES DOWN INTO THE 10-17 PERCENT RANGE ARE FORECAST FOR THIS
AFTERNOON. ALTHOUGH THIS IS ALREADY SOLIDLY INTO CRITICAL
TERRITORY..ITS WORTH NOTING THAT HIGH-RES SHORT TERM MODELS SUCH
AS THE RAP13 AND HRRR SUGGEST THAT SOME PLACES COULD SEE RH
VALUES DROP A FEW PERCENTAGE POINTS LOWER YET...AND THIS WILL NEED
MONITORED. AS FOR THE WIND ASPECT OF THE SITUATION...THINGS ARE A
BIT MORE IFFY AS SUSTAINED WINDS ARE CURRENTLY EXPECTED TO PREVAIL
FROM THE SOUTHWEST AT MAINLY 15-20 MPH IN MOST AREAS...OR
GENERALLY JUST BELOW CRITICAL THRESHOLDS. HOWEVER...GIVEN THE
PRESENCE OF DEEP MIXING UP INTO THE 800-750 MILLIBAR LEVEL PER
VARIOUS FORECAST SOUNDINGS...FEEL THAT POTENTIAL IS PRETTY HIGH
FOR SEMI-FREQUENT GUSTS OF 25+ MPH TO MATERIALIZE...ESPECIALLY
ACROSS NORTHERN AND EASTERN PORTIONS OF THE NEBRASKA CWA AND ALSO
MOST KS ZONES. HOWEVER...THANKS TO THE PRESENCE OF A LOW LEVEL
TROUGH AXIS STRETCHING EAST-NORTHEAST OUT OF EAST-CENTRAL
CO...SOMEWHAT LIGHTER BREEZES ARE EXPECTED WITHIN A HANDFUL OF
COUNTIES IN THE SOUTHWESTERN CWA...ESPECIALLY FURNAS COUNTY WHERE
EVEN GUSTS COULD STRUGGLE TO CONSISTENTLY EXCEED 15-20 MPH.
DESPITE SOMEWHAT OF A WIND-MINIMUM IN THIS SOUTHWESTERN
AREA...HAVE OPTED TO ERR ON THE SIDE OF CAUTION GIVEN SUCH LOW
RELATIVE HUMIDITY VALUES AND DRY FUELS..AND JUST INCLUDE THE
ENTIRE CWA IN THE RED FLAG WARNING.
LOOKING AHEAD TO FRIDAY...AFTERNOON TEMPERATURE READINGS GENERALLY
IN THE LOWER 60S WILL WORK IN CONCERT WITH DEW POINT READINGS IN
THE LOWER 20S TO PROMOTE RELATIVE HUMIDITY READINGS NEAR 20%
ACROSS MUCH OF THE CWA FRIDAY AFTERNOON. THANKFULLY...A DECREASING
LOWER TROPOSPHERIC PRESSURE GRADIENT SHOULD PROMOTE AN AFTERNOON
SURFACE WIND OF ONLY 5-10 MPH. AS A RESULT...CRITICAL FIRE WEATHER
CONDITIONS ARE NOT EXPECTED...AND GIVEN THE VERY LIGHT LOWER
TROPOSPHERIC WIND FIELD...WILL ALSO HOLD OFF FROM ANY FIRE WEATHER
MENTION IN THE HWO.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS
EVENING FOR NEZ039>041-046>049-060>064-072>077-082>087.
KS...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS
EVENING FOR KSZ005>007-017>019.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...BRYANT
AVIATION...PFANNKUCH
FIRE WEATHER...PFANNKUCH/BRYANT
AREA FORECAST DISCUSSION
NWS MEDFORD OR
845 AM PDT THU MAR 13 2014
.SHORT TERM...HIGH PRESSURE WILL REMAIN OVER THE AREA TODAY. SOME
AREAS OF SHALLOW FOG DEVELOPED EARLY THIS MORNING IN THE COQUILLE
VALLEY, UMPQUA VALLEY, GRANTS PASS AREA AND ILLINOIS VALLEY. THE
FOG IS EXPECTED TO BURN OFF LATE THIS MORNING. THEN EXPECT MAINLY
SUNNY AND WARM CONDITIONS TODAY. HAVE ADDED PATCHY MORNING FOG AND
HAVE RAISED TEMPERATURES SLIGHTLY FOR THE AFTERNOON. OTHERWISE
THE FORECAST REMAINS ON TRACK. HIGH CLOUDS ARE EXPECTED TO
INCREASE OVER THE AREA THIS EVENING INTO TONIGHT AS A LOW PRESSURE
CENTER MOVES INLAND WELL TO THE NORTH. THIS SYSTEM WILL BRING A
WEAK WARM FRONT INTO NORTHWEST PORTIONS OF THE AREA. THE WARM
FRONT WILL BRING SOME LIGHT RAIN INTO THE AREA LATE TONIGHT AND
FRIDAY MORNING. THEN A WEAK COLD FRONT PUSHES ACROSS THE AREA
FRIDAY AFTERNOON AND EXPECT SOME LIGHT SHOWERS IN MOIST NORTHWEST
FLOW, MAINLY ALONG THE CASCADES AND WESTWARD IN OREGON.
&&
.AVIATION...
BASED ON THE 13/12Z TAF CYCLE...ASIDE FROM MVFR/IFR
CEILINGS AND/OR VISIBILITIES ALONG THE COAST THIS MORNING...VFR
CONDITIONS WILL PREVAIL THROUGH THIS EVENING. THE ONLY EXCEPTION
INLAND WILL BE SOME BRIEF IFR/MVFR VISIBILITIES IN PATCHY FOG
THROUGH 17Z NEAR ROSEBURG AND IN GRANTS PASS AREA AND INTO THE
ILLINOIS VALLEY. A WEAK FRONT WILL BRING INCREASING HIGH AND MID
LEVEL CLOUDS LATE THIS AFTERNOON INTO THIS EVENING AND THERE IS A
CHANCE THAT CIGS LOWER TO MVFR AT THE COAST AND UMPQUA BASIN LATE
TONIGHT. ELSEWHERE VFR CONDITIONS WILL PREVAIL FOR THE NEXT 24
HOURS.
&&
.MARINE...THE LATEST OB AT BUOY 15 SHOWS GUSTY NORTH WINDS, BUT SO
FAR HAVE REMAINED BELOW SMALL CRAFT. THE RAP 13 APPEARS TO BE
HANDLING THIS WELL AND HAVE LEANED TOWARDS THIS SOLUTION THROUGH
THIS MORNING. WINDS ARE EXPECTED TO DECREASE THIS AFTERNOON AS
OFFSHORE HIGH PRESSURE WEAKENS. MODERATE WEST SWELL IS EXPECTED TO
PERSIST THIS MORNING, THEN SHOULD SUBSIDE THIS AFTERNOON. THE WAVE
WATCH BULLETIN APPEARS A BIT UNDERDONE WITH THE WAVE HEIGHT AND HAVE
LEANED TOWARDS THE SWAN SOLUTION, THIS HAVE EXTENDED THE END TIME OF
THE SMALL CRAFT FOR SEAS UNTIL 11 AM PDT. A COLD FRONT WILL MOVE
THROUGH THE WATERS FRIDAY. WINDS AND WIND DRIVEN SEAS WILL INCREASE
OVER THE NORTHERN PART OF THE REGION AHEAD OF THE FRONT FRIDAY
MORNING, BUT ARE EXPECTED TO REMAIN BELOW SMALL CRAFT. THE WAVE
WATCH AND ENP WAVE MODELS ARE IN SIMILAR AGREEMENT SHOWING ANOTHER
ROUND OF MODERATE WESTERLY SWELL WILL DEVELOPING LATE SATURDAY
NIGHT...PEAKING OUT SUNDAY AFTERNOON THEN GRADUALLY SUBSIDING SUNDAY
NIGHT. THE GFS AND EC DIFFER WITH THE TIMING AND STRENGTH OF THE
NEXT COLD FRONT MONDAY. THE EC IS STRONGER AND GFS IS WEAKER AND
SLOWER. FOR NOW WENT WITH A BLEND BETWEEN THE TWO FOR THE WIND
FORECAST. -PETRUCELLI
&&
.PREV DISCUSSION... /ISSUED 259 AM PDT THU MAR 13 2014/
SHORT TERM...THE FLOW WILL TURN ONSHORE ACROSS THE WEST SIDE
TODAY AS THE UPPER RIDGE THAT`S BEEN OVER THE AREA FOR THE LAST
FEW DAYS WEAKENS AND MOVES EAST. EVEN THOUGH WE HAVE SOME HIGH
CLOUD OVER THE WEST SIDE THIS MORNING, WE WILL PROBABLY SEE MORE
LOW CLOUD AND FOG DEVELOP IN THE UMPQUA AND ILLINOIS BASINS AS
TEMP/DEWPOINT SPREADS ARE LOW AND THESE AREAS ARE PRONE TO SUCH
OCCURRENCES. IT IS ALREADY STARTING TO HAPPEN ALONG THE COOS
COAST, PER SATELLITE. LIKE YESTERDAY, THIS SHOULD BURN OFF BY MID
MORNING, PERHAPS LASTING LONGER AT THE COAST THOUGH. DON`T THINK
IT WILL HAPPEN IN THE ROGUE VALLEY, AND THE CURRENT FORECAST
LOOKS ABOUT RIGHT IN THAT REGARD.
ASIDE FROM THE MORNING CLOUD/FOG, MOST OF US WILL ONLY SEE SOME
HIGH CLOUD TODAY, BUT THERE IS A PRETTY OBVIOUS AREA OF MARINE
STRATUS JUST OUTSIDE OUR MARINE WATERS THIS MORNING WHICH WILL BE
APPROACHING THE COAST THIS AFTERNOON AND MOVING ONSHORE TONIGHT.
THIS PUSH WILL MEAN MUCH COOLER WEATHER TODAY AT THE COAST THAN WE
SAW YESTERDAY. SOME OF THIS COOLING WILL ALSO BE FELT IN THE
UMPQUA BASIN, BUT THE REST OF THE WEST SIDE WILL JUST SEE A FEW
DEGREES OF COOLING - HARDLY NOTICEABLE. THE EAST SIDE AND NORTHERN
CALIFORNIA WILL LIKELY BE A TOUCH WARMER THAN YESTERDAY.
A SHORTWAVE TROUGH MOVES BY TO THE NORTH TOMORROW. WITH MUCH OF
ITS DYNAMICS NORTH OF US, THE BULK OF THE RAIN WILL ALSO BE TO
OUR NORTH. WE WILL LIKELY SEE SOME RAIN OVER THE NORTH COAST,
UMPQUA BASIN, AND INTO THE NORTH CASCADES TOMORROW. IT`S NOT A
PARTICULARLY WET SYSTEM, BUT I DID RAISE POPS AND QPF IN THESE
AREAS. THE REST OF US COULD SEE SOME RAIN, BUT MUCH LESS
PROBABILITY THAN NORTHERN AREAS.
THE SYSTEM WILL BE A QUICK HITTER WITH THE CHANCE FOR RAIN ENDING
QUICKLY FRIDAY NIGHT. THEN A RIDGE SPRINGS UP OVER THE PACNW WHICH
WILL BRING ANOTHER ROUND OF SUNNY AND WARM WEATHER THIS WEEKEND.
HIGHS LOOK TO BE EVEN WARMER THAN OUR LAST EPISODE WITH AT LEAST
LOW 70S FOR HIGHS BY SUNDAY IN THE WEST SIDE VALLEYS. THE EXTENDED
IS STILL LOOKING POTENTIALLY UNSETTLED, BUT CONFIDENCE IN MODEL
SOLUTIONS REMAINS LOW. THE PREVIOUS EXTENDED DISCUSSION IS STILL
TRUE, AND IT FOLLOWS FOR REFERENCE. -WRIGHT
LONG TERM...SUNDAY THROUGH WEDNESDAY NIGHT...MODELS START OUT
IN TIGHT AGREEMENT ON SUNDAY...THEN WANDER OFF IN MANY DIRECTIONS.
BY MONDAY MORNING THE GFS HAS A DEEP TROUGH OFFSHORE WHILE THE
ECMWF HAS A WEAK RIDGE IN THE SAME LOCATION. FROM THERE CONFIDENCE
DECREASES FURTHER AS THE ENSEMBLE PLOTS ARE ALL OVER THE PLACE...WITH
NO SINGLE PLOT LIKE ANY OTHER PLOT. WITH THIS IN MIND WE HAVE GONE
WITH NEAR CLIMO POPS FOR THE REMAINDER OF THE EXTENDED. SVEN
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PDT THIS
MORNING FOR PZZ350-356-370-376.
$$
CC
AREA FORECAST DISCUSSION
NWS MEDFORD OR
259 AM PDT THU MAR 13 2014
.SHORT TERM...THE FLOW WILL TURN ONSHORE ACROSS THE WEST SIDE
TODAY AS THE UPPER RIDGE THAT`S BEEN OVER THE AREA FOR THE LAST
FEW DAYS WEAKENS AND MOVES EAST. EVEN THOUGH WE HAVE SOME HIGH
CLOUD OVER THE WEST SIDE THIS MORNING, WE WILL PROBABLY SEE MORE
LOW CLOUD AND FOG DEVELOP IN THE UMPQUA AND ILLINOIS BASINS AS
TEMP/DEWPOINT SPREADS ARE LOW AND THESE AREAS ARE PRONE TO SUCH
OCCURRENCES. IT IS ALREADY STARTING TO HAPPEN ALONG THE COOS
COAST, PER SATELLITE. LIKE YESTERDAY, THIS SHOULD BURN OFF BY MID
MORNING, PERHAPS LASTING LONGER AT THE COAST THOUGH. DON`T THINK
IT WILL HAPPEN IN THE ROGUE VALLEY, AND THE CURRENT FORECAST
LOOKS ABOUT RIGHT IN THAT REGARD.
ASIDE FROM THE MORNING CLOUD/FOG, MOST OF US WILL ONLY SEE SOME
HIGH CLOUD TODAY, BUT THERE IS A PRETTY OBVIOUS AREA OF MARINE
STRATUS JUST OUTSIDE OUR MARINE WATERS THIS MORNING WHICH WILL BE
APPROACHING THE COAST THIS AFTERNOON AND MOVING ONSHORE TONIGHT.
THIS PUSH WILL MEAN MUCH COOLER WEATHER TODAY AT THE COAST THAN WE
SAW YESTERDAY. SOME OF THIS COOLING WILL ALSO BE FELT IN THE
UMPQUA BASIN, BUT THE REST OF THE WEST SIDE WILL JUST SEE A FEW
DEGREES OF COOLING - HARDLY NOTICEABLE. THE EAST SIDE AND NORTHERN
CALIFORNIA WILL LIKELY BE A TOUCH WARMER THAN YESTERDAY.
A SHORTWAVE TROUGH MOVES BY TO THE NORTH TOMORROW. WITH MUCH OF
ITS DYNAMICS NORTH OF US, THE BULK OF THE RAIN WILL ALSO BE TO
OUR NORTH. WE WILL LIKELY SEE SOME RAIN OVER THE NORTH COAST,
UMPQUA BASIN, AND INTO THE NORTH CASCADES TOMORROW. IT`S NOT A
PARTICULARLY WET SYSTEM, BUT I DID RAISE POPS AND QPF IN THESE
AREAS. THE REST OF US COULD SEE SOME RAIN, BUT MUCH LESS
PROBABILITY THAN NORTHERN AREAS.
THE SYSTEM WILL BE A QUICK HITTER WITH THE CHANCE FOR RAIN ENDING
QUICKLY FRIDAY NIGHT. THEN A RIDGE SPRINGS UP OVER THE PACNW WHICH
WILL BRING ANOTHER ROUND OF SUNNY AND WARM WEATHER THIS WEEKEND.
HIGHS LOOK TO BE EVEN WARMER THAN OUR LAST EPISODE WITH AT LEAST
LOW 70S FOR HIGHS BY SUNDAY IN THE WEST SIDE VALLEYS. THE EXTENDED
IS STILL LOOKING POTENTIALLY UNSETTLED, BUT CONFIDENCE IN MODEL
SOLUTIONS REMAINS LOW. THE PREVIOUS EXTENDED DISCUSSION IS STILL
TRUE, AND IT FOLLOWS FOR REFERENCE. -WRIGHT
LONG TERM...SUNDAY THROUGH WEDNESDAY NIGHT...MODELS START OUT
IN TIGHT AGREEMENT ON SUNDAY...THEN WANDER OFF IN MANY DIRECTIONS.
BY MONDAY MORNING THE GFS HAS A DEEP TROUGH OFFSHORE WHILE THE
ECMWF HAS A WEAK RIDGE IN THE SAME LOCATION. FROM THERE CONFIDENCE
DECREASES FURTHER AS THE ENSEMBLE PLOTS ARE ALL OVER THE PLACE...WITH
NO SINGLE PLOT LIKE ANY OTHER PLOT. WITH THIS IN MIND WE HAVE GONE
WITH NEAR CLIMO POPS FOR THE REMAINDER OF THE EXTENDED. SVEN
&&
.AVIATION...BASED ON THE 13/06Z TAF CYCLE...ASIDE FROM MVFR/IFR
CEILINGS AND/OR VISIBILITIES ALONG THE COAST AND IN THE UMPQUA BASIN
OVERNIGHT AND INTO TOMORROW MORNING...VFR CONDITIONS WILL PREVAIL. AN
APPROACHING WEAK FRONT WILL INCREASE CLOUDINESS AND WINDS LATE
THURSDAY...BUT NO SIGNIFICANT IMPACTS ARE EXPECTED.
&&
.MARINE...THE LATEST OB AT BOUY 15 SHOWS GUSTY NORTH WINDS, BUT SO
FAR HAVE REMAINED BELOW SMALL CRAFT. THE RAP 13 APPEARS TO BE
HANDLING THIS WELL AND HAVE LEANED TOWARDS THIS SOLUTION THROUGH
THIS MORNING. WINDS ARE EXPECTED TO DECREASE THIS AFTERNOON AS
OFFSHORE HIGH PRESSURE WEAKENS. MODERATE WEST SWELL IS EXPECTED TO
PERSIST THIS MORNING, THEN SHOULD SUBSIDE THIS AFTERNOON. THE WAVE
WATCH BULLETIN APPEARS A BIT UNDERDONE WITH THE WAVE HEIGHT AND HAVE
LEANED TOWARDS THE SWAN SOLUTION, THIS HAVE EXTENDED THE END TIME OF
THE SMALL CRAFT FOR SEAS UNTIL 11 AM PDT. A COLD FRONT WILL MOVE
THROUGH THE WATERS FRIDAY. WINDS AND WIND DRIVEN SEAS WILL INCREASE
OVER THE NORTHERN PART OF THE REGION AHEAD OF THE FRONT FRIDAY
MORNING, BUT ARE EXPECTED TO REMAIN BELOW SMALL CRAFT. THE WAVE
WATCH AND ENP WAVE MODELS ARE IN SIMILAR AGREEMENT SHOWING ANOTHER
ROUND OF MODERATE WESTERLY SWELL WILL DEVELOPING LATE SATURDAY
NIGHT...PEAKING OUT SUNDAY AFTERNOON THEN GRADUALLY SUBSIDING SUNDAY
NIGHT. THE GFS AND EC DIFFER WITH THE TIMING AND STRENGTH OF THE
NEXT COLD FRONT MONDAY. THE EC IS STRONGER AND GFS IS WEAKER AND
SLOWER. FOR NOW WENT WITH A BLEND BETWEEN THE TWO FOR THE WIND
FORECAST. -PETRUCELLI
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL
11 AM PDT THIS MORNING FOR PZZ350-356-370-376.
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
616 AM CDT THU MAR 13 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM CDT THU MAR 13 2014
AT 3 AM...A WARM FRONT WAS LOCATED OVER WESTERN MINNESOTA.
THE COMBINATION OF 280 TO 290K ISENTROPIC LIFT AND STRONG 900 TO
800 MB FRONTOGENETIC LIFT WAS PRODUCING A 6 TO 8K DECK OF CLOUDS
ALONG AND WEST OF THE INTERSTATE 35 CORRIDOR. THERE WERE EVEN A
FEW REPORTS OF 2K FOOT CLOUDS BRIEFLY AT MASON CITY. THESE CLOUDS
WERE HELPING TO RISE TEMPERATURES INTO THE LOWER AND MID 30S.
MEANWHILE WHERE SKIES WERE STILL CLEAR...TEMPERATURES RANGE FROM
THE SINGLE DIGITS TO MID TEENS.
TODAY - THE WARM FRONT WILL MOVE EAST ACROSS THE FORECAST AREA.
AT MOST LOCATIONS...THE NAM AND GFS SOUNDINGS BECOME VERY
SATURATED BELOW 900 MB LATE THIS MORNING AND AFTERNOON. MEANWHILE
BOTH THE RAP HAS THIS LAYER DRY. NORMALLY...THE GFS AND NAM HAVE
PROBLEMS IN THIS SYNOPTIC SITUATION WHERE YOU HAVE STRONG WARM
AIR ADVECTION GOING UP AN OVER A SNOW PACK. WHILE THIS CAN
OCCUR...A SIMILAR SIGNAL IS SHOWING UP IN THE BUFKIT SOUNDINGS AT
BOTH FAIRMONT AND REDWOOD FALLS AND NEITHER LOCATION HAS ANY LOW
CLOUDS. DUE TO THE LOW LEVELS BEING DRIER THAN EXPECTED REMOVED
THE MENTION OF FREEZING DRIZZLE AND SNOW FOR MUCH OF THE AREA THIS
MORNING. THE ONLY PLACE THAT A MENTION OF FLURRIES WAS KEPT IN WAS
OVER IN CENTRAL WISCONSIN WHERE THE ARW HINTS THAT THERE MAY BE
SOME VERY LIGHT PRECIPITATION AROUND 13.15Z.
TONIGHT - THE 13.00Z MODELS ARE IN GOOD AGREEMENT THAT A SHORT
WAVE TROUGH AND COLD FRONT WILL MOVE SOUTHEAST THROUGH THE
REGION. THE AIR MASS AHEAD OF THIS FRONT IS VERY DRY DUE TO
THE DOWN SLOPED AIR BEING BROUGHT INTO THE AREA FROM THE NORTHERN
PLAINS. AS A RESULT...ONLY EXPECT SOME CLOUDS ASSOCIATED WITH
THIS SYSTEM.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 339 AM CDT THU MAR 13 2014
FROM FRIDAY INTO FRIDAY EVENING...THE 13.00Z MODELS ARE IN GOOD
AGREEMENT THAT A SECONDARY FRONT WILL REMAIN STATIONARY OVER
NORTHERN MINNESOTA AND NORTHERN WISCONSIN. AT THE SAME TIME...A
SERIES OF WEAK SHORT WAVES WILL BE MOVING ALONG THIS BOUNDARY. THE
COLD FRONT LOOKS CLOSE ENOUGH TO CLARK AND TAYLOR COUNTIES TO
WARRANT A SLIGHT CHANCE OF SNOW.
ON SATURDAY AND SATURDAY NIGHT...THE COLD FRONT WILL MOVE SOUTH
THROUGH THE FORECAST AREA. THE GFS HAS THE STRONGEST COLD AIR
ADVECTION IN THE WAKE OF THIS FRONT. MEANWHILE THE NAM HAS THE
WEAKEST COLD AIR ADVECTION. THE ECMWF WAS A NICE COMPROMISE
BETWEEN THE TWO...SO TRENDED TOWARD IT FOR TEMPERATURES. THERE
LOOKS TO BE ENOUGH LIFT AND MOISTURE NORTH OF INTERSTATE 94 FOR
A MENTION OF SOME LIGHT SNOW. MEANWHILE DURING THE AFTERNOON AND
EVENING...BOTH THE NAM AND ECMWF SUGGEST SOME WEAK TO MODERATE
CYCLOGENESIS TAKING PLACE ACROSS WESTERN AND SOUTHERN IOWA. THE
285 AND 290K ISENTROPIC SURFACES BECOME SATURATED ENOUGH TO
SUGGEST THE POSSIBILITY THAT A BAND OF SNOW COULD DEVELOP EITHER
ON THE INTERSTATE 90 CORRIDOR /ECMWF/ OR ACROSS NORTHEAST IOWA AND
SOUTHWEST WISCONSIN /GFS...GEM...AND NAM/. SINCE THIS IS A
RELATIVELY NEW DEVELOPMENT IN THE MODELS...OPTED TO GO WITH THE
BETTER SNOW CHANCES IN AREAS WHERE THERE WAS THE BEST MODEL
CONSENSUS.
FROM SUNDAY NIGHT INTO TUESDAY...THE MODELS CONTINUE TO STRUGGLE
ON TRACK AND TIMING OF A SERIES OF SYSTEMS MOVING THROUGH THE
REGION. SINCE THERE HAS BEEN VERY LITTLE RUN TO RUN
CONSISTENCY...JUST STAYED WITH THE MODEL CONSENSUS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 616 AM CDT THU MAR 13 2014
BAND OF VFR CLOUDS AHEAD OF THE APPROACHING FRONT WILL CONTINUE TO
MOVE EAST AND SHOULD CLEAR OUT OF BOTH TAF SITES BY MID MORNING.
EXPECT TO SEE SOUTH TO SOUTHWEST WINDS BETWEEN 10 AND 15 KNOTS
BEHIND THE WARM FRONT. AS THE WARM AIR COMES IN ALOFT...THE
INVERSION SHOULD REMAIN IN PLACE THROUGH THE DAY. THUS WITH VERY
LIMITED MIXING...NOT EXPECTING TO SEE MUCH IN THE WAY FOR GUSTS
TODAY. THE 13.06Z NAM CONTINUES TO SHOW THE POTENTIAL FOR SOME
WIND SHEAR TONIGHT AT KLSE. HOWEVER...THE 13.06Z GFS DOES NOT
INCREASE THE WINDS ALOFT QUITE AS MUCH AS THE NAM AND WOULD KEEP
THE SPEEDS JUST UNDER WIND SHEAR CRITERIA. CONFIDENCE THAT THIS
WILL OCCUR IS NOT VERY HIGH...ESPECIALLY WITH THE NAM HAVING A
BIAS OF BEING TOO STRONG WITH WIND SPEEDS...BUT SINCE IT WAS
ALREADY IN THE FORECAST...WILL LEAVE IT FOR NOW. THE WIND SHEAR
WILL END OVERNIGHT AS THE FIRST OF TWO COLD FRONT MOVES THROUGH
AND SWINGS THE SURFACE WINDS AROUND TO THE NORTHWEST WITH WIND
SPEEDS ALOFT DIMINISHING ENOUGH TO DROP THIS FROM THE FORECAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1237 PM EDT THU MAR 13 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 340 AM EDT THU MAR 13 2014
THE TRANSITIONAL PATTERN WILL CONTINUE TO CREATE WIDE
SWINGS IN THE WEATHER THROUGH THE FORECAST PERIOD. TODAY
TEMPERATURES WILL RUN SEVERAL DEGREES BELOW NORMAL IN THE WAKE OF
YESTERDAYS COLD FRONTAL PASSAGE. HIGH PRESSURE SLIDING TO THE EAST
WILL ALLOW WARM TEMPERATURES TO RETURN FOR FRIDAY BUT THE
DEVELOPMENT OF ANOTHER UPPER RIDGE WEST/UPPER TROUGH EAST PATTERN
SETS UP...BRINGING SPORADIC LOW CHANCES FOR PRECIPITATION AS WELL AS
TEMPERATURES SWINGING FROM WELL BELOW NORMAL TO NEAR/JUST ABOVE
NORMAL NEARLY DAILY THROUGH THE PERIOD.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1005 AM EDT THU MAR 13 2014
SATELLITE INDICATED MOSTLY CLEAR SKIES ACROSS OUR REGION...WHILE AN
AREA OF CLOUDS OVER NORTHWEST ILLINOIS WAS EXPANDING VERY SLOWLY
EASTWARD. AT THE PRESENT RATE OF MOVEMENT IT WILL BE HARD PRESSED TO
REACH OUR FAR NORTHWEST BY 18Z...SO WILL BACK OFF ON SKY COVER A
LITTLE KEEPING MOST AREAS MOSTLY SUNNY WELL INTO THIS AFTERNOON. THE
MODELS INDICATE NORTHERN SECTIONS MAY BECOME PARTLY CLOUDY THIS
AFTERNOON AND WILL STILL INDICATE THIS SOMEWHAT...BUT LESS CLOUDS
THAN THE PREVIOUS FORECAST.
CONCERNING TEMPERATURES...WARM ADVECTION WILL BE INCREASING THIS
AFTERNOON AS SURFACE RIDGE OVER OUR AREA MOVES EASTWARD. GIVEN MARCH
SUN AND THAT RAP SURFACE TEMPERATURES ARE A LITTLE WARMER WILL RAISE
HIGHS MOST AREAS A DEGREE OR TWO LATER TODAY. THERE WILL BE A SHARP
TEMPERATURE GRADIENT TODAY WITH HIGHS RANGING FROM THE LOWER 30S
RANDOLPH COUNTY TO THE MID AND UPPER 40S FAR SOUTHWEST.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 340 AM EDT THU MAR 13 2014
HIGH PRESSURE SLIDES TO THE EAST TONIGHT AND WARM ADVECTION GETS
GOING. TEMPERATURES WILL LIKELY DROP A BIT EARLY BUT THEN STEADY OUT
AND EVEN START TO CLIMB BY MORNING. FRIDAY WITH WARM ADVECTION AND
UPPER RIDGING IN PLACE EXPECT TO SEE SIGNIFICANT WARMING AND WENT
WITH THE WARMER MAV NUMBERS FOR HIGHS IN THE MID 50S TO LOWER 60S.
FRIDAY NIGHT A COLD FRONT WILL MOVE THROUGH THE AREA. FRIDAY NIGHT/S
FRONTAL PASSAGE IS LOOKING DRIER THIS SET OF MODEL RUNS...WITH NAM
AND GFS NO LONGER CARRYING ANY QPF ACROSS THE FORECAST AREA.
OPERATIONAL GFS SHOWING VIRTUALLY NO FORCING WITH THE WASHED OUT
FRONT AND Q VECTOR DIVERGENCE ALOFT IMPLYING SOME SINKING MOTION.
MOS NUMBERS ARE NOW DRY FOR MAV AND MET AS WELL. HOWEVER...ENSEMBLES
ARE STILL SHOWING SOME VARIABILITY AND ENSEMBLE MOS NUMBERS ARE
SHOWING ANYWHERE FROM DRY TO HIGH CHANCE POPS. WITH THAT KIND OF
VARIABILITY PREFER NOT TO GO TOTALLY DRY AND KEEP A SLIGHT CHANCE
GOING ACROSS THE EASTERN COUNTIES FOR NOW. THERMAL PROFILES ARE WARM
ENOUGH FOR PRECIP TO BE RAIN SHOULD IT OCCUR.
SATURDAY FAIRLY NEUTRAL ADVECTION WILL BE IN PLACE BUT 850 MB
TEMPERATURES DON/T CLIMB MUCH ABOVE ZERO. WITH PARTLY CLOUDY SKIES
AND TEMPERATURES ALOFT SEVERAL DEGREES COOLER THAN FRIDAY WENT WITH
THE COOLER MET NUMBERS FOR SATURDAY HIGHS IN THE MID 40S TO UPPER
50S.
SATURDAY NIGHT MODELS ARE STARTING TO KEY IN ON A WARM FRONT FORMING
SOUTH OF THE AREA. THIS COULD BRING IN RAIN TO THE SOUTHERN COUNTIES
LATE AND WENT WITH POPS BETWEEN THE MAV AND MET.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY NIGHT/...
ISSUED AT 351 AM EDT THU MAR 13 2014
MODELS CONTINUE TO SHOW INCONSISTENCIES THROUGH THE LONG TERM
PERIOD. LATEST INITIALIZATION SEEMS TO FAVOR THE WETTER EURO
THOUGH BY KEEPING PRECIP CHANCES OVER THE SOUTHERN PORTIONS OF THE
FORECAST AREA ON SUNDAY AS A LOW PASSES OVER THE DEEP SOUTH. AFTER
DRY CONDITIONS ON MONDAY...THE PATTERN BECOMES A TAD MORE ACTIVE
AROUND MID-WEEK WITH A BROAD UPPER LOW BRINGING PRECIP CHANCES FOR
TUESDAY AND WEDNESDAY. RAIN WILL BE THE PREDOMINANT PRECIP TYPE.
MEANWHILE...THE WARM SECTOR OF A SURFACE LOW WILL RESULT IN HIGH
TEMPS TOPPING OFF IN THE UPPER 50S BY THE SECOND HALF OF THE
EXTENDED PERIOD.
&&
.AVIATION /DISCUSSION FOR THE 131800Z TAFS/...
ISSUED AT 1237 PM EDT THU MAR 13 2014
SMALL AREA OF MVFR CEILINGS AROUND 020 CURRENTLY LOCATED ALONG THE
ILLINOIS/INDIANA STATE LINE HAS BEEN DRIFTING EAST THROUGHOUT THE
MORNING HOURS. SATELLITE SHOWS THESE CEILINGS HAVE BEEN RAPIDLY
DISSIPATING OVER THE PAST HOUR OR SO...SO NOT EXPECTING ANY
PROLONGED MVFR CEILINGS AT THE TAF SITES THIS AFTERNOON.
DOES APPEAR THERE WILL BE A PERIOD LATER THIS AFTERNOON/EARLY
EVENING OF CEILINGS ABOVE 050.
SURFACE WINDS SHOULD SETTLE AROUND 180-200 DEGREES AT 8-11 KTS THIS
AFTERNOON AS SURFACE RIDGE PASSES OFF TO THE EAST.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...JH
SHORT TERM...CP
LONG TERM....TDUD
AVIATION...JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
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AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
324 PM EDT THU MAR 13 2014
LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/HYDRO
.SYNOPSIS...
ISSUED AT 323 PM EDT THU MAR 13 2014
A CLIPPER TYPE SURFACE LOW WILL TRACK NORTH OF LAKE SUPERIOR
TONIGHT THEN HEAD EAST TOWARD SOUTHERN QUEBEC FRIDAY NIGHT. THAT
WILL BRING A STRONG WARM FRONT THROUGH THE AREA EARLY FRIDAY
MORNING. TEMPERATURES MAY ACTUALLY RISE OVERNIGHT AS THE MUCH
WARMER AIR SURGES IN. THE COLD FRONT TRAILING THE SYSTEM WILL
CROSS SOUTHWEST LOWER MICHIGAN FRIDAY AFTERNOON BRINGING THE COLD
AIR BACK INTO THE REGION THROUGH THE WEEKEND. THERE COULD BE A
PERIOD OF MIXED LIGHT RAIN AND LIGHT SNOW FRIDAY AFTERNOON THAT
WOULD TURN TO FLURRIES FRIDAY NIGHT AS THE COLD AIR COMES IN.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 323 PM EDT THU MAR 13 2014
THE MAIN ISSUE WITH THIS FORECAST IS JUST HOW WARM DOES IT GET
FRIDAY AS YET ANOTHER STRONG SURGE OF WARM AIR MOVES IN OVER OUR
DEEP SNOW COVER. THERE IS THE POTENTIAL FOR SOME SPRINKLES OR
FLURRIES NEAR AND NORTH OF ROUTE 10 THIS EVENING JUST AHEAD OF THE
WARM FRONT. ALSO A BETTER SHOT AT LIGHT PRECIPITATION FRIDAY
AFTERNOON INTO EARLY SATURDAY AS THE COLD AIR COMES BACK IN ONCE
AGAIN.
CURRENT RADAR LOOPS SHOW SNOW FALLING FROM A MID CLOUD DECK OVER
EASTERN LAKE MICHIGAN HOWEVER THE AIR BELOW THIS IS VERY DRY SO I
DO NOT BELIEVE THIS CAN REACH THE GROUND. I DID NOT PUT POP FOR
THIS SINCE EVEN IF IT DOES HAPPEN IT WOULD NOT BE MEASURABLE.
THE NEXT ISSUE IS TEMPERATURES... JUST WHAT WILL THEY DO?
CURRENTLY WE HAVE TEMPERATURES IN THE 50S IN IOWA AND EVEN IN
EASTERN WISCONSIN LOWER 30S ARE COMMON. DEW POINTS ARE IN THE MID
30S WEST OF THE MISSISSIPPI RIVER. ALL OF THIS IS HEADING TOWARD
SOUTHWEST LOWER MICHIGAN. ALSO GIVEN THE 35 TO 50 KNOT WINDS
OVERNIGHT IN THE 1000 TO 3000 FT AGL LAYER... IT WOULD SEEM TO ME
TEMPERATURES MUST RISE OVERNIGHT... SO THAT IS WHAT I HAVE IN THE
GRIDS. THE RAP AND HRRR OUTGOING LONGWAVE RADIATION FORECAST
SUGGESTS WHAT THE NAM INDICATES THAT THE LOW CLOUDS WILL LIKELY
STAY NEAR AND NORTH OF ROUTE 10 OVERNIGHT.
FRIDAY WILL SEE ANOTHER ONE OF THOSE SURGE WARM UPS... EVEN WITH
THE SNOW COVER THE BOUNDARY LAYER IS SO WARM (925 MB TEMP REACHED
45F BY 12Z OVER GRR) I HAVE TO BELIEVE HIGHS WILL BE BETWEEN 45
AND 50 BUT I WENT CONSERVATIVE WITH HIGHS IN THE MID 40S.
THERE IS A SHORTWAVE WITH THE COLD FRONT AND MOISTURE WHILE STILL
SHALLOW IS DEEP ENOUGH FOR THE DGZ TO ACTIVATE A LITTLE LIGHT
PRECIPITATION FRIDAY EVENING INTO EARLY SATURDAY. NOTHING MUCH
THROUGH... MOSTLY LESS THAN .05 QPF.
THE LOW LEVEL MOISTURE HANGS IN THERE INTO SATURDAY EVENING AS A
SYSTEM GOES BY TO OUR SOUTH SO THERE IS A CHANCE OF FLURRIES
SATURDAY BUT TEMPERATURES WILL MOSTLY BE IN THE LOWER TO MID 30S
DURING THE DAY. SOME CLEARING AND MUCH COLDER BY SUNDAY MORNING AS
AN ARCTIC HIGH MOVES IN FROM.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 323 PM EDT THU MAR 13 2014
A SOUTHERN STREAM SYSTEM MOVING ACROSS THE DEEP SOUTH WILL HELP TO
DRAW DOWN COLDER AIR FROM CANADA SUNDAY AND MONDAY. AFTER THAT A
DEVELOPING PLAINS LOW WILL MOVE EAST. LATEST ECMWF AND GFS SHOW THE
LOW MOVING OVER SOUTHEAST WISCONSIN TUESDAY/TUESDAY NIGHT. THE ECMWF
IS THE FARTHEST NORTHWEST WITH THE TRACK. THIS TRACK WOULD RESULT IN
WARMER AIR MOVING OVER THE CWA. WE HAVE A MIX OF RAIN AND SNOW IN
THE GRIDS AND THAT SEEMS LIKE A GOOD POSSIBILITY THIS FAR OUT GIVEN
THICKNESS VALUES IN NEAR 548DAM. AS THE SYSTEM OCCLUDES
WEDNESDAY...COLDER AIR WILL BEGIN TO MOVE INTO THE WRN CWA...SO WE
CHANGED THE MIXED PCPN BACK TO SNOW WEDNESDAY AFTERNOON. COLDER AIR
THEN REMAINS ENTRENCHED OVER THE CWA THROUGH THE REST OF THE PERIOD.
CERTAINLY LOOKS LIKE TEMPS WILL REMAIN WELL BELOW NORMAL THROUGH THE
PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 134 PM EDT THU MAR 13 2014
HIGHER DEWPOINTS WILL MOVE INTO LOWER MICHIGAN AFTER SUNSET. AS
THIS OCCURS, WE`LL LIKELY SEE SOME STRATOCU DEVELOP. WE ONLY WENT
SCATTERED WITH IT, BUT I WOULDN`T BE SURPRISED TO SEE IT BECOME A
BROKEN CIG AROUND 1500 FEET. VISIBILITIES WILL ALSO DECREASE A
BIT. HOWEVER, INCREASING WINDS WILL HELP TO MITIGATE THAT AND SO
VISIBILITIES LIKELY WON`T FALL BELOW 5SM BR.
&&
.HYDROLOGY...
ISSUED AT 323 PM EDT THU MAR 13 2014
THE PERIODS OF WARMER TEMPERATURE WITH LIMITED RAIN MIXED WITH COLD
SNAPS OF LATE HAS RESULTED IN A DECREASE IN ICE DEPTH ON RIVERS AND
HAS DECREASED THE MOISTURE TRAPED IN THE SNOW PACK. CURRENT SNOW
WATER EQUIVALENT VALUES ARE GENERALLY IN THE 2 TO 4 INCH RANGE. THIS
WEATHER PATTERN IS EXPECTED TO CONTINUE THROUGH THE NEXT WEEK...
WHICH SHOULD LOWER THE CHANCES FOR ICE JAM FORMATION AND FLOODING AS
WE PROGRESS INTO SPRING.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...93
AVIATION...93
HYDROLOGY...63
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1220 PM CDT THU MAR 13 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 436 AM CDT THU MAR 13 2014
FROM A STRICTLY TEMPERATURE/SKY COVER STANDPOINT...TODAY IS GOING
TO BE ANOTHER SPRING-FEVER SETUP WITH HIGHS CLIMBING RIGHT UP TO
AROUND 70 DEGREES IN ALL AREAS UNDER ESSENTIALLY WALL-TO-WALL
SUNSHINE. HOWEVER...FOR THOSE WITH POTENTIAL CONCERNS OF ENHANCED
FIRE DANGER THIS IS REALLY THE ONLY FLY IN THE OINTMENT...AND IN FACT
CONDITIONS HAVE BEEN DEEMED SEVERE ENOUGH TO JUSTIFY A CWA-WIDE
RED FLAG WARNING FOR THIS AFTERNOON. PLEASE REFER TO THE SEPARATE
FIRE SECTION BELOW FOR MUCH MORE DETAIL ON THESE ISSUES.
STARTING OFF WITH THE HERE AND NOW...11-3.9 MICRON SATELLITE
IMAGERY CONFIRMS THAT THERE ARE VIRTUALLY NO CLOUDS
TO SPEAK OF WHATSOEVER EARLY THIS MORNING...NOT ONLY WITHIN THE CWA
BUT ALSO EXTENDING SEVERAL HUNDRED MILES IN NEARLY ALL DIRECTIONS.
WATER VAPOR SATELLITE IMAGERY AND SHORT TERM MODEL DATA DEPICT THE
LOCAL AREA TO BE UNDER THE INFLUENCE OF DRY NORTHWESTERLY
FLOW/SUBTLE SHORTWAVE RIDGING OF A RIDGE AXIS CENTERED FROM
WYOMING-ONTARIO. MEANWHILE...A NEARLY STALLED-OUT MID LEVEL CLOSED
LOW CONTINUES CHURNING OVER SOUTHERN CA/NV. PUT ANOTHER WAY...THE
CENTRAL PLAINS IS UNDER AN UPPER LEVEL WIND MINIMUM IN BETWEEN THE
PRIMARY SPLIT UPPER JET STREAMS...WITH THE NORTHERN BRANCH
EXTENDING ACROSS THE CANADIAN BORDER AREA AND THEN SOUTHWARD
ACROSS THE GREAT LAKES...WHILE THE SOUTHERN BRANCH SNAKES ACROSS
THE SOUTHERN TIER OF THE CONUS. AT THE SURFACE...A FAIRLY WEAK
PRESSURE GRADIENT REGIME IS IN PLACE ACROSS THE AREA...WITH THE
CENTRAL PLAINS GENERALLY POSITIONED BETWEEN A TX RIDGE AXIS...AND
A LOW PRESSURE SYSTEM CENTERED WAY TO THE NORTH OVER SOUTH CENTRAL
CANADA. AS A RESULT...THE GENERAL PREVAILING BREEZE EARLY THIS
MORNING IS SOME VARIATION OF WESTERLY WITH SPEEDS ONLY 5-10 MPH.
DESPITE THESE LIGHT WESTERLY BREEZES...THE PRESENCE OF CLEAR SKIES
AND DRY AIR HAS ALLOWED A FAIRLY EFFICIENT TEMPERATURE DROP...AND
CURRENTLY HAVE MORNING LOW TEMPERATURES AIMED INTO THE 25-28 RANGE
ACROSS MOST OF THE AREA.
GETTING INTO THE DAYTIME HOURS TODAY...THE MID/UPPER LEVEL SCENE
INVOLVES A CONTINUATION OF THE AREA REMAINING IN BETWEEN THE
PRIMARY JET AXES...ALTHOUGH SLOWLY BUT SURELY FLOW WILL TRANSITION
FROM MORE NORTHWESTERLY TO MORE QUASI-ZONAL AS BOTH BRANCHES OF
THE JET SEND LOW AMPLITUDE SHORTWAVE TROUGHS EASTWARD AND
SOUTHEASTWARD TOWARD THE CENTRAL PLAINS. DESPITE THIS...BOTH
FORECAST SOUNDINGS AND PLAN-VIEW RELATIVE HUMIDITY PROGS SHOW A
REMARKABLY DRY DEEP-LAYER AIRMASS...AND OTHER THAN MAYBE A VERY
LIMITED COVERAGE OF THIN HIGH CIRRUS THIS AFTERNOON...WIDESPREAD
SUNSHINE IS DEFINITELY IN STORE. AT THE SURFACE...THE PRESSURE
GRADIENT WILL SHARPEN UP A BIT AS THE DAY GOES ON...IN RESPONSE TO
THE AFOREMENTIONED SOUTHERN CANADA LOW PRESSURE SYSTEM MIGRATING
DOWN TO NEAR THE NORTHERN TIP OF MN BY LATE AFTERNOON/EARLY
EVENING. AS THIS OCCURS...A TRAILING TROUGH AXIS WILL SHARPEN FROM
THE DAKOTAS SOUTH-SOUTHWESTWARD INTO EASTERN CO...OR GENERALLY
REMAINING JUST WEST OF THE CWA. WITHIN THIS PRESSURE FIELD...A
COUPLE OF MODEST LOWER-LEVEL WIND MAXIMUMS EVIDENT AT 850
MILLIBARS WILL SET UP...ONE MORE SOUTHWESTERLY AND EXTENDING FROM
SOUTH CENTRAL KS TO SOUTHEAST NEB...AND THE OTHER MORE WESTERLY
AND EXTENDING WEST-EAST ACROSS CENTRAL NEB. THANKS TO VERY DEEP
MIXING UP INTO THE 800-750MB LEVEL...IT WON/T TAKE MUCH TO
GENERATE SUSTAINED 15-20 MPH BREEZES WITH GUSTS TO AROUND 25 MPH
ACROSS MOST OF THE CWA FROM THE LATE-MORNING TO LATE-AFTERNOON
HOURS...WITH A BIT OF A LIGHTER WIND REGIME FOCUSING NEAR THE
SURFACE TROUGH AXIS IN THE FAR SOUTHWESTERN CWA...ESPECIALLY
AROUND FURNAS COUNTY. IN OTHER WORDS...IT WILL BE A BIT BREEZY
MUCH OF THE DAY BUT OVERLY WINDY. TEMP-WISE...AFTER HAVING DECENT
LUCK THE LAST FEW DAYS BLENDING THE 00Z NAM WITH A RECENT RAP13
RUN TO DERIVE HIGHS...TOOK THE SAME APPROACH FOR TODAY...WHICH
YIELDS GENERALLY A 1-3 DEGREE INCREASE IN MOST AREAS...NOW PUTTING
MOST PLACES SOMEWHERE IN THE 68-73 RANGE. IN CONTRAST...DEWPOINTS
WERE LOWERED SEVERAL DEGREES FROM PREVIOUS FORECAST...THUS PLAYING
INTO THE HIGH FIRE DANGER OUTLINED BELOW.
GETTING INTO THIS EVENING/TONIGHT BEYOND 00Z/7PM...THE PRIMARY
NORTHERN STREAM MOISTURE-STARVED MID LEVEL SHORTWAVE TROUGH WILL
SWING PRIMARILY ACROSS THE DAKOTAS-MN...AND ONLY GIVING THE LOCAL
AREA A GLANCING BLOW. DESPITE THIS DISTURBANCE MOVING
THROUGH...EXPECTING NO MORE THAN A SLIGHT INCREASE IN HIGH
CLOUDS...AND STILL AVERAGING MOSTLY CLEAR THROUGH THE NIGHT. THIS
DISTURBANCE WILL MAKE ITSELF A BIT MORE OBVIOUS DOWN AT THE
SURFACE...AS A MODEST COLD FRONT MAKES ITS WAY ACROSS THE CWA FROM
NORTHWEST-SOUTHEAST AS THE NIGHT GOES ON. INITIALLY BEFORE
MIDNIGHT...MOST PLACES WILL HOLD ONTO A WEST TO SOUTHWEST BREEZE
GENERALLY 5-15 MPH...BUT THEN AS THE FRONT MOVES THROUGH BREEZES
WILL SWITCH NORTHWESTERLY AT GENERALLY 10-15 MPH...WITH A BRIEF
PERIOD OF GUSTINESS TO AROUND 20 MPH LIKELY IN THE WAKE OF THIS
BOUNDARY...WHICH SHOULD CLEAR EVEN THE FAR SOUTHEAST CWA BY A FEW
HOURS BEFORE SUNRISE. TEMP-WISE...DESPITE DECENT MIXING BEHIND THE
PASSING COLD FRONT...THERE IS JUST ENOUGH LOW LEVEL COLD AIR
ADVECTION THAT WOULD EXPECT TO SEE A DECENT TEMPERATURE DROP
MAINLY LATE IN THE NIGHT/TOWARD SUNRISE FRIDAY MORNING. AS A
RESULT...ONLY TWEAKED PREVIOUS LOW TEMPS A FEW DEGREES MAINLY
DOWNWARD...WITH THE MAJORITY OF THE CWA AIMED INTO THE 31-35
RANGE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 436 AM CDT THU MAR 13 2014
GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC AND SREF-MEAN ALL
SUGGEST QUASI-ZONAL TO NORTHWESTERLY MID TO UPPER TROPOSPHERIC FLOW
WILL PERSIST OVER THE CENTRAL PLAINS DURING MUCH OF THE LONG TERM
FORECAST PERIOD. A MID-TROPOSPHERIC SHORT WAVE IS EXPECTED TO MOVE
ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY THURSDAY
NIGHT INTO FRIDAY...BUT ANY APPRECIABLE OMEGA IN ASSOCIATION THIS SHORT
WAVE SHOULD REMAIN WELL NORTHEAST OF OUR AREA. ANOTHER
MID-TROPOSPHERIC SHORT WAVE IS THEN EXPECTED TO MOVE EAST ACROSS THE
SOUTHERN PLAINS SATURDAY INTO SATURDAY NIGHT. A TRAILING
MID-TROPOSPHERIC PERTURBATION IS THEN EXPECTED TO MOVE SOUTHEAST
ACROSS THE CENTRAL HIGH PLAINS SATURDAY NIGHT INTO SUNDAY...WITH
THIS PERTURBATION EXPECTED TO EVENTUALLY MERGE WITH THE PRIMARY
MID-TROPOSPHERIC SHORT WAVE OVER THE SOUTHERN PLAINS DURING THE DAY
SUNDAY. AT THIS TIME IT APPEARS ANY APPRECIABLE OMEGA IN ASSOCIATION
WITH THE SHORT WAVE MOVING OVER THE SOUTHERN PLAINS WILL REMAIN WILL
SOUTH OF OUR AREA. WEAK OMEGA IN ASSOCIATION WITH TRAILING
PERTURBATION MAY BE JUST ENOUGH TO PROMOTE LIGHT PRECIPITATION ACROSS
PORTIONS OF OUR AREA SATURDAY NIGHT...A SOLUTION SUPPORTED BY QPF
FIELDS FROM NAM...EC AND SREF-MEAN. GIVEN THIS IS A QUICK-MOVING
CLIPPER WITH MODEST OMEGA AND QUESTIONABLE MID TO LOWER TROPOSPHERIC
MOISTURE...OPTED TO GO NO HIGHER THAN ~20% POPS ACROSS THE CWA
SATURDAY NIGHT. THAT BEING SAID...IT IS WORTH NOTING THAT THE NAM
AND SREF-MEAN BOTH SUGGEST THIS PERTURBATION WILL ACTUALLY STRENGTHEN
RATHER DRAMATICALLY OVER THE CENTRAL HIGH PLAINS...THUS RESULTING IN
AN AREA OF SURFACE CYCLOGENESIS OVER NORTHEASTERN NEBRASKA SUNDAY
NIGHT. ALTHOUGH THIS PERTURBATION...AND ASSOCIATED SURFACE LOW IF
REALIZED...ARE NOT EXPECTED TO LINGER NEAR THE AREA VERY LONG...BOTH
THE NAM AND SREF-MEAN SUGGEST THE INCREASING SOUTHEASTERLY LOWER
TROPOSPHERIC FLOW WILL RESULT IN A HEALTHY DOSE OF LOWER
TROPOSPHERIC THERMAL AND MOISTURE ADVECTION...WITH A BRIEF BUT
SUBSTANTIAL AXIS OF ISENTROPIC UPGLIDE NEAR THE 290K
SURFACE...RESEMBLING A TROWAL EXTENDING FROM SOUTHERN MISSOURI INTO
SOUTHEASTERN NEBRASKA AND THEN BACK INTO NORTH CENTRAL
KANSAS...LIKELY GRAZING OUR SOUTHEASTERN CWA. QPF FIELDS FROM
THE NAM RESPOND BY PRESENTING A BAND OF HEAVY PRECIPITATION OVER OUR
SOUTHEAST...WITH LIQUID PRECIPITATION AMOUNTS IN THE 0.25-0.50"
RANGE. CONTEMPLATED GOING WITH A HIGHER POP ACROSS OUR SOUTHEAST AS
A RESULT...BUT SINCE THE NAM AND SREF-MEAN ARE THE ONLY MODELS
SUGGESTING SUCH A SETUP...AND SINCE THE NAM IS THE ONLY MODEL
PRODUCING SUCH COPIOUS AMOUNTS OF PRECIPITATION...AND SINCE THE
OPERATIONAL GFS AND EC BOTH SUGGEST DRY CONDITIONS OR VERY LIGHT
PRECIPITATION ACROSS OUR SOUTHEAST...OPTED TO KEEP OUR SOUTHEAST IN
THE SAME ~20% POP BOAT AS THE REST OF THE CWA. CERTAINLY SOMETHING
TO MONITOR THROUGH THE NEXT FEW DAYS.
FORECAST PROXIMITY SOUNDINGS FROM THE ACROSS THE CWA...PER THE NAM
AND OPERATIONAL GFS...SUGGEST THE LOWER TROPOSPHERE WILL REMAIN WARM
ENOUGH FOR RAIN TO START SATURDAY NIGHT...BUT WILL EVENTUALLY COOL
TO SUPPORT SNOW PRODUCTION BY EARLY SUNDAY MORNING. GIVEN ALL
THIS..WENT AHEAD WITH A MIX OF RAIN AND SNOW IN THE OFFICIAL
FORECAST FOR SATURDAY NIGHT.
AS FOR THE REST OF THE LONG TERM FORECAST PERIOD...THERE ARE
INDICATIONS OF A LONGWAVE MID TROPOSPHERIC TROUGH SETTING UP OVER
THE WESTERN CONUS BY EARLY NEXT WEEK. MID TROPOSPHERIC THERMAL
ADVECTION...OR PERHAPS PERIODIC MID TROPOSPHERIC PERTURBATIONS
EJECTING FROM THE PRIMARY TROUGH AXIS...COULD PROMOTE JUST ENOUGH
OMEGA FOR PRECIPITATION PRODUCTION OVER THE AREA EARLY NEXT
WEEK...BUT AT THIS TIME THE PROBABILITY OF ACCURATELY PREDICTING
SUCH ACTIVITY IS TOO LOW TO JUSTIFY POPS. A DRY FORECAST HAS BEEN
PRESENTED SUNDAY AND BEYOND AS A RESULT.
LITTLE CHANGE IN THE LOWER TROPOSPHERIC AIR MASS SHOULD PROMOTE
AFTERNOON TEMPERATURE READINGS GENERALLY IN THE 50S AND 60S FRIDAY
AND SATURDAY. THE INTRUSION OF A COOLER LOWER TROPOSPHERIC AIR
MASS SHOULD THEN PROVIDE HIGHS IN THE 40S AND LOW 50S ON
SUNDAY...WITH HIGHS REBOUNDING INTO THE 50S AND 60S TO FINISH THE
FORECAST PERIOD. OVERNIGHT LOWS IN THE 20S AND 30S ARE EXPECTED FOR
THE MOST PART DURING THE LONG TERM FORECAST PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1220 PM CDT THU MAR 13 2014
EXPECT CLEAR SKIES THROUGH THE PERIOD. A WEAK SURFACE TROUGH WILL
MOVE THROUGH THE AREA AND TURN WINDS FROM SOUTHWEST THIS EVENING
TO NORTHWEST OVERNIGHT.
&&
.FIRE WEATHER...
ISSUED AT 436 AM CDT THU MAR 13 2014
AS HAS BEEN ADVERTISED FOR A FEW DAYS NOW...TODAY CONTINUES TO
LOOK MORE AND MORE LIKE THE OVERALL-WORST DAY THIS WEEK FOR FIRE
DANGER ACROSS THE AREA (SINCE SUNDAY OF COURSE)...AND AS A RESULT
A CWA-WIDE RED FLAG WARNING HAS BEEN ISSUED FOR THIS AFTERNOON
THROUGH 00Z/7PM. BEFORE GOING ON...WANT TO BRIEFLY REMIND THAT
FOR OUR CWA CRITICAL FIRE THRESHOLDS ARE THE OVERLAP OF SUSTAINED
WINDS AND/OR GUSTS OF 20/25 MPH AND RELATIVE HUMIDITY (RH) OF 20
PERCENT OR LESS FOR 3+ HOURS...IN THE PRESENCE OF VERY DRY
VEGETATION (FUELS).
IN TODAY/S CASE...ITS REALLY THE LOW RH COMPONENT OF THE EQUATION
THAT HAS TIPPED THE SCALES TOWARD RED FLAG WARNING
ISSUANCE...WITH WIND SPEEDS LOOKING A BIT MORE MARGINAL. AS A
RESULT OF BUMPING UP HIGH TEMPERATURES A FEW DEGREES AND ALSO
LOWERING AFTERNOON DEWPOINTS AT LEAST A FEW DEGREES...WIDESPREAD
RH VALUES DOWN INTO THE 10-17 PERCENT RANGE ARE FORECAST FOR THIS
AFTERNOON. ALTHOUGH THIS IS ALREADY SOLIDLY INTO CRITICAL
TERRITORY..ITS WORTH NOTING THAT HIGH-RES SHORT TERM MODELS SUCH
AS THE RAP13 AND HRRR SUGGEST THAT SOME PLACES COULD SEE RH
VALUES DROP A FEW PERCENTAGE POINTS LOWER YET...AND THIS WILL NEED
MONITORED. AS FOR THE WIND ASPECT OF THE SITUATION...THINGS ARE A
BIT MORE IFFY AS SUSTAINED WINDS ARE CURRENTLY EXPECTED TO PREVAIL
FROM THE SOUTHWEST AT MAINLY 15-20 MPH IN MOST AREAS...OR
GENERALLY JUST BELOW CRITICAL THRESHOLDS. HOWEVER...GIVEN THE
PRESENCE OF DEEP MIXING UP INTO THE 800-750 MILLIBAR LEVEL PER
VARIOUS FORECAST SOUNDINGS...FEEL THAT POTENTIAL IS PRETTY HIGH
FOR SEMI-FREQUENT GUSTS OF 25+ MPH TO MATERIALIZE...ESPECIALLY
ACROSS NORTHERN AND EASTERN PORTIONS OF THE NEBRASKA CWA AND ALSO
MOST KS ZONES. HOWEVER...THANKS TO THE PRESENCE OF A LOW LEVEL
TROUGH AXIS STRETCHING EAST-NORTHEAST OUT OF EAST-CENTRAL
CO...SOMEWHAT LIGHTER BREEZES ARE EXPECTED WITHIN A HANDFUL OF
COUNTIES IN THE SOUTHWESTERN CWA...ESPECIALLY FURNAS COUNTY WHERE
EVEN GUSTS COULD STRUGGLE TO CONSISTENTLY EXCEED 15-20 MPH.
DESPITE SOMEWHAT OF A WIND-MINIMUM IN THIS SOUTHWESTERN
AREA...HAVE OPTED TO ERR ON THE SIDE OF CAUTION GIVEN SUCH LOW
RELATIVE HUMIDITY VALUES AND DRY FUELS..AND JUST INCLUDE THE
ENTIRE CWA IN THE RED FLAG WARNING.
LOOKING AHEAD TO FRIDAY...AFTERNOON TEMPERATURE READINGS GENERALLY
IN THE LOWER 60S WILL WORK IN CONCERT WITH DEW POINT READINGS IN
THE LOWER 20S TO PROMOTE RELATIVE HUMIDITY READINGS NEAR 20%
ACROSS MUCH OF THE CWA FRIDAY AFTERNOON. THANKFULLY...A DECREASING
LOWER TROPOSPHERIC PRESSURE GRADIENT SHOULD PROMOTE AN AFTERNOON
SURFACE WIND OF ONLY 5-10 MPH. AS A RESULT...CRITICAL FIRE WEATHER
CONDITIONS ARE NOT EXPECTED...AND GIVEN THE VERY LIGHT LOWER
TROPOSPHERIC WIND FIELD...WILL ALSO HOLD OFF FROM ANY FIRE WEATHER
MENTION IN THE HWO.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR NEZ039>041-
046>049-060>064-072>077-082>087.
KS...RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR KSZ005>007-
017>019.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...BRYANT
AVIATION...JCB
FIRE WEATHER...PFANNKUCH/BRYANT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1224 PM CDT THU MAR 13 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM CDT THU MAR 13 2014
AT 3 AM...A WARM FRONT WAS LOCATED OVER WESTERN MINNESOTA.
THE COMBINATION OF 280 TO 290K ISENTROPIC LIFT AND STRONG 900 TO
800 MB FRONTOGENETIC LIFT WAS PRODUCING A 6 TO 8K DECK OF CLOUDS
ALONG AND WEST OF THE INTERSTATE 35 CORRIDOR. THERE WERE EVEN A
FEW REPORTS OF 2K FOOT CLOUDS BRIEFLY AT MASON CITY. THESE CLOUDS
WERE HELPING TO RISE TEMPERATURES INTO THE LOWER AND MID 30S.
MEANWHILE WHERE SKIES WERE STILL CLEAR...TEMPERATURES RANGE FROM
THE SINGLE DIGITS TO MID TEENS.
TODAY - THE WARM FRONT WILL MOVE EAST ACROSS THE FORECAST AREA.
AT MOST LOCATIONS...THE NAM AND GFS SOUNDINGS BECOME VERY
SATURATED BELOW 900 MB LATE THIS MORNING AND AFTERNOON. MEANWHILE
BOTH THE RAP HAS THIS LAYER DRY. NORMALLY...THE GFS AND NAM HAVE
PROBLEMS IN THIS SYNOPTIC SITUATION WHERE YOU HAVE STRONG WARM
AIR ADVECTION GOING UP AN OVER A SNOW PACK. WHILE THIS CAN
OCCUR...A SIMILAR SIGNAL IS SHOWING UP IN THE BUFKIT SOUNDINGS AT
BOTH FAIRMONT AND REDWOOD FALLS AND NEITHER LOCATION HAS ANY LOW
CLOUDS. DUE TO THE LOW LEVELS BEING DRIER THAN EXPECTED REMOVED
THE MENTION OF FREEZING DRIZZLE AND SNOW FOR MUCH OF THE AREA THIS
MORNING. THE ONLY PLACE THAT A MENTION OF FLURRIES WAS KEPT IN WAS
OVER IN CENTRAL WISCONSIN WHERE THE ARW HINTS THAT THERE MAY BE
SOME VERY LIGHT PRECIPITATION AROUND 13.15Z.
TONIGHT - THE 13.00Z MODELS ARE IN GOOD AGREEMENT THAT A SHORT
WAVE TROUGH AND COLD FRONT WILL MOVE SOUTHEAST THROUGH THE
REGION. THE AIR MASS AHEAD OF THIS FRONT IS VERY DRY DUE TO
THE DOWN SLOPED AIR BEING BROUGHT INTO THE AREA FROM THE NORTHERN
PLAINS. AS A RESULT...ONLY EXPECT SOME CLOUDS ASSOCIATED WITH
THIS SYSTEM.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 339 AM CDT THU MAR 13 2014
FROM FRIDAY INTO FRIDAY EVENING...THE 13.00Z MODELS ARE IN GOOD
AGREEMENT THAT A SECONDARY FRONT WILL REMAIN STATIONARY OVER
NORTHERN MINNESOTA AND NORTHERN WISCONSIN. AT THE SAME TIME...A
SERIES OF WEAK SHORT WAVES WILL BE MOVING ALONG THIS BOUNDARY. THE
COLD FRONT LOOKS CLOSE ENOUGH TO CLARK AND TAYLOR COUNTIES TO
WARRANT A SLIGHT CHANCE OF SNOW.
ON SATURDAY AND SATURDAY NIGHT...THE COLD FRONT WILL MOVE SOUTH
THROUGH THE FORECAST AREA. THE GFS HAS THE STRONGEST COLD AIR
ADVECTION IN THE WAKE OF THIS FRONT. MEANWHILE THE NAM HAS THE
WEAKEST COLD AIR ADVECTION. THE ECMWF WAS A NICE COMPROMISE
BETWEEN THE TWO...SO TRENDED TOWARD IT FOR TEMPERATURES. THERE
LOOKS TO BE ENOUGH LIFT AND MOISTURE NORTH OF INTERSTATE 94 FOR
A MENTION OF SOME LIGHT SNOW. MEANWHILE DURING THE AFTERNOON AND
EVENING...BOTH THE NAM AND ECMWF SUGGEST SOME WEAK TO MODERATE
CYCLOGENESIS TAKING PLACE ACROSS WESTERN AND SOUTHERN IOWA. THE
285 AND 290K ISENTROPIC SURFACES BECOME SATURATED ENOUGH TO
SUGGEST THE POSSIBILITY THAT A BAND OF SNOW COULD DEVELOP EITHER
ON THE INTERSTATE 90 CORRIDOR /ECMWF/ OR ACROSS NORTHEAST IOWA AND
SOUTHWEST WISCONSIN /GFS...GEM...AND NAM/. SINCE THIS IS A
RELATIVELY NEW DEVELOPMENT IN THE MODELS...OPTED TO GO WITH THE
BETTER SNOW CHANCES IN AREAS WHERE THERE WAS THE BEST MODEL
CONSENSUS.
FROM SUNDAY NIGHT INTO TUESDAY...THE MODELS CONTINUE TO STRUGGLE
ON TRACK AND TIMING OF A SERIES OF SYSTEMS MOVING THROUGH THE
REGION. SINCE THERE HAS BEEN VERY LITTLE RUN TO RUN
CONSISTENCY...JUST STAYED WITH THE MODEL CONSENSUS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1224 PM CDT THU MAR 13 2014
GOOD VFR CONDITIONS AS FAR AS CIGS/VSBYS...WITH SOUTH WINDS IN THE
10-15KT RANGE...WILL PREVAIL ACROSS THE TAF SITES THIS AFTERNOON AND
TONIGHT. WINDS AROUND 2K FT AGL WILL BE IN THE 40KT RANGE DURING THE
MID EVENING INTO OVERNIGHT HOURS...AHEAD OF AN APPROACHING COLD
FRONT. THESE WINDS WITH SOUTH SFC WINDS AROUND 10KTS AT KLSE...WILL
LEAVE LLWS MENTION IN KLSE TAF FOR THE 03Z-09Z PERIOD. SFC FRONT
WILL PUSH ACROSS THE AREA LATER TONIGHT...SWINGING THE WINDS AROUND
TO WEST-NORTHWEST ALONG WITH LIGHTER 925MB WINDS.
COOLING BEHIND THE FRONT WILL PRODUCE SOME DEEPER MIXING...AND GUSTY
WINDS AT SITE LIKE KRST BY MID MORNING. SIGNAL FOR INCREASING LOWER
LEVEL MOISTURE TO SPREAD SOUTHEAST ACROSS THE TAF SITES FRI MORNING
BEHIND THE FRONT. HOWEVER...WITH WHAT WILL BE A LOT OF DRIER LOW
LEVEL AIR TO OVERCOME AND THE DEEPER MIXING...ONLY CARRIED SCT020-
025 CLOUDS IN THE TAFS AFTER 14-15Z FRI MORNING AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM....BOYNE
AVIATION.....RRS