Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/27/14
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
230 PM MST TUE FEB 25 2014
.SYNOPSIS...
DRY WESTERLY FLOW IS EXPECTED TO CONTINUE INTO EARLY FRIDAY ACROSS
THE REGION...KEEPING TEMPERATURES ABOVE NORMAL...RISING INTO THE
UPPER 70S TO LOWER 80S EACH DAY ACROSS THE LOWER DESERTS...WITH
PERIODS OF HIGH CLOUDS PASSING OVERHEAD FROM TIME TO TIME. A
DRAMATIC CHANGE IN THE WEATHER IS THEN EXPECTED FROM LATE FRIDAY
INTO THE UPCOMING WEEKEND AS A STRONG...AND WET PACIFIC STORM MOVES
INTO THE DESERT SOUTHWEST. THIS STORM IS EXPECTED TO BRING
WIDESPREAD SIGNIFICANT RAINFALL...AND MUCH COOLER TEMPERATURES TO
THE REGION.
&&
.DISCUSSION...
SUBTROPICAL MOISTURE IN THE FORM OF MID AND HIGH CLOUDS CONTINUES TO
STREAM NORTHEASTWARD ACROSS SOUTHERN AZ AHEAD OF A WEAK VORT MAX
NORTH OF PUERTO PENASCO. LATEST RADAR IMAGERY SHOWS SOME WEAK ECHOES
ACROSS SE AZ AND HI-RES WRF GUIDANCE ALONG WITH THE HRRR SUGGEST
SPRINKLES MAY CLIP PORTIONS OF EASTERN MARICOPA...PINAL AND SOUTHERN
GILA COUNTIES THROUGH LATE THIS AFTERNOON. SOMEWHAT OF A CLEARING
TREND FROM WEST TO EAST IS ANTICIPATED OVERNIGHT...THOUGH AREAS OF
CIRRUS WILL STILL BE PREVALENT.
WEDNESDAY...SHORT-WAVE RIDGE BECOMES REESTABLISHED ACROSS THE DESERT
SOUTHWEST. LATEST MODEL CONSENSUS INDICATES THAT THICKER HIGH CLOUDS
ASSOCIATED WITH THE NEXT PACIFIC TROUGH WILL SLIDE THROUGH MAINLY
NORTHERN AZ IN THE AFTERNOON. THE INCREASED INSOLATION SHOULD YIELD
HIGH TEMPERATURES A FEW DEGREES WARMER THAN THOSE OBSERVED TUESDAY
AND STILL ABOVE NORMAL.
&&
.PREVIOUS DISCUSSION...
THURSDAY...
MODELS CONTINUE TO BRING A WEAK SHORTWAVE EASTWARD INTO THE GREAT
BASIN/4-CORNERS REGION DURING THE DAY ON THURSDAY. ALTHOUGH THE
LATEST MODEL RUNS STILL KEEP MOST OF THE MOISTURE AND DYNAMICS WELL
TO OUR NORTH...THE LATEST GEM AND EURO MODEL SUITES NOW ARE
FORECASTING A SLIGHT CHANCE FOR SPRINKLES...OR LIGHT SHOWERS OVER
THE HIGHEST ELEVATIONS OF SOUTHERN GILA COUNTY...AS THE CLOUD BASES
LOWER TO AROUND...OR JUST BELOW 10K FEET BRIEFLY ON THURSDAY.
THUS...HAVE INCREASED POPS OVER THAT REGION INTO THE SLIGHT CHANCE
RANGE TO REFLECT THESE CHANGES. HOWEVER...IT STILL APPEARS THAT THE
MAIN IMPACTS FROM THIS SYSTEM WILL BE ONLY TO BRING GUSTY WINDS TO
SOUTHEAST CA WEDNESDAY AFTERNOON AND EVENING...AND TO INCREASE
CLOUDINESS OVER THE REGION.
FRIDAY AND SATURDAY...
IT NOW APPEARS THAT IT IS ALMOST CERTAIN THAT WE WILL SEE A MAJOR
CHANGE IN THE WEATHER FROM FRIDAY ONWARD INTO THE UPCOMING WEEKEND.
IN FACT...ALL OF THE LATEST MODEL RUNS ARE EVEN MORE BULLISH WITH
THIS SYSTEM THEN THEY WERE ON PREVIOUS RUNS. THERE IS NOW EXCELLENT
AGREEMENT BETWEEN THE EURO...GFS...AND GEM THAT THIS SYSTEM...WHICH
IS NOW TRACKING EASTWARD ACROSS THE CENTRAL PACIFIC SOUTH OF THE
ALEUTIAN CHAIN...WILL NOW PICK UP COPIOUS AMOUNTS OF MOISTURE AS IT
INTERACTS WITH A VERY STRONG (180KT) PACIFIC JET THAT EXTENDS ALL
THE WAY EASTWARD FROM SOUTHERN JAPAN (130E) TO NORTHEAST OF HAWAII
(ABOUT 150W). ALL THREE MODELS NOW PUSH THE SYSTEM INLAND
EARLIER...INTO SOUTHERN CA BY FRIDAY MORNING...THEN SLOWLY ACROSS
OUR CWA FROM LATE FRIDAY INTO EARLY SUNDAY. LATEST GFS PWAT
FORECASTS NOW PUSH A PLUME OF 1 INCH OR GREATER PWATS INTO...AND
ACROSS OUR CWA LATE FRIDAY AND SATURDAY. BOTH THE GFS AND EURO
FORECAST SOUNDINGS FOR KPHX ARE NOW SHOWING A VERY DEEP NEARLY
SATURATED MOISTURE LAYER...ALL THE WAY FROM THE SFC TO 35K FEET
MOVING IN ON SATURDAY...WITH STRONG SW-LY WINDS THROUGH THE ENTIRE
COLUMN...SOMETHING WE DON/T SEE VERY OFTEN AROUND HERE.
ALL THREE MODELS HAVE ALSO GREATLY INCREASED THEIR QPF FORECASTS.
THEY NOW ARE FORECASTING STORM TOTAL RAINFALL AMOUNTS OF 0.25-0.50
OF AN INCH FOR THE LOWER ELEVATIONS OF SE CA AND SW AZ...0.75-1.25
INCH FOR JOSHUA TREE NB AND ACROSS THE LOWER ELEVATIONS OF
SOUTH-CENTRAL ARIZONA...AND 1 TO 2 INCHES ACROSS THE HIGHER TERRAIN
OF SOUTH-CENTRAL ARIZONA. ALTHOUGH WIDESPREAD HYDRO ISSUES ARE VERY
UNLIKELY...DUE TO THE VERY DRY ANTECEDENT CONDITIONS...THERE WOULD
BE LIKELY SOME SMALL STREAM AND URBAN FLOODING ISSUES IF THESE
RAINFALL AMOUNTS DUE VERIFY.
BASED ON THESE UPDATED FORECAST...I HAVE GREATLY INCREASED POPS
ACROSS OUR WESTERN ZONES LATE FRIDAY AND PUSHED POPS INTO THE LIKELY
TO CATEGORICAL RANGE FOR MUCH OF OUR CWA ON SATURDAY. IN
ADDITION...I HAVE LOWERED HIGH TEMPS FURTHER ACROSS SOUTH-CENTRAL
ARIZONA ON SATURDAY...INTO THE LOW TO MID 60S AS THE LIKELY STEADY
RAIN AND THICK CLOUD COVER SHOULD KEEP TEMPS WELL BELOW NORMAL...A
RATHER RAW AND WET DAY FOR A VERY BUSY SLATE OF OUTDOOR ACTIVITIES
THAT ARE PLANNED ACROSS THE GREATER PHX AREA. ON THE OTHER
HAND...SNOWFALL CONCERNS ACROSS OUR CWA APPEAR TO BE A
NON-ISSUE...AS THE SUBTROPICAL ORIGIN OF THE AIRMASS IS EXPECTED TO
KEEP SNOW LEVELS MAINLY AOA 7000FT. AHEAD OF THE SYSTEM...WE ALSO
NOW EXPECT STRONG SOUTH TO SOUTHWESTERLY WINDS ON FRIDAY AFTERNOON
ACROSS SOUTHEAST CA AND THE LOWER CO RIVER VALLEY...WITH WIND SPEEDS
APPROACHING ADVISORY CRITERIA AT SOME LOCATIONS.
SUNDAY THROUGH TUESDAY...
SOME LINGERING SHOWERS ARE LIKELY ON SUNDAY...AND MAYBE EVEN INTO
MONDAY ACROSS SOUTH-CENTRAL ARIZONA AS GENERAL TROUGHINESS HANGS
BACK OVER OUR REGION...BUT FURTHER SIGNIFICANT RAINFALL IS NOW
EXPECTED AT THIS TIME. NEXT TUESDAY SHOULD SEE WARMER...AND DRIER
CONDITIONS AS RIDGING ATTEMPTS TO REBUILD BACK OVER THE DESERT
SOUTHWEST.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
CONTINUED HIGH PRESSURE ALOFT TODAY INTO WEDNESDAY...HOWEVER IT WILL
BE A DIRTY RIDGE ALLOWING CONSIDERABLE MID/HI CLOUDS TO OVERSPREAD
THE TERMINALS. EXPECT SCT-BKN MID AND HI LEVEL DECKS FROM 12K FEET
ON UP NEXT 24 HOURS...WITH THE DEEPEST MOISTURE ACROSS THE CENTRAL
AZ DESERT TAF SITES. WINDS TO REMAIN QUITE LIGHT AND VARIABLE WITH
WEAK DIURNAL SIGNALS AT KIWA AND KPHX TODAY AND TONIGHT. NO AVIATION
CONCERNS NEXT 24 HOURS AT ANY AIRFIELD.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
A FAST MOVING DISTURBANCE PASSING BY TO THE NORTH WILL LEAD TO
AFTERNOON BREEZY CONDITIONS THURSDAY...AND CAUSE HUMIDITIES TO
BECOME ELEVATED WITH MOST DESERTS CLIMBING ABOVE 20 PERCENT.
OTHERWISE HIGH TEMPERATURES WILL STAY ABOVE SEASONAL NORMALS. HIGH
PRESSURE ALOFT WILL BRIEFLY RETURN FRIDAY FOR CONTINUED ABOVE NORMAL
HIGH TEMPERATURES...HOWEVER MOISTURE WILL INCREASE FROM THE WEST
AHEAD OF AN APPROACHING WET PACIFIC LOW PRESSURE SYSTEM...AND A
CHANCE OF SHOWERS WILL DEVELOP ACROSS THE WESTERN DESERTS DURING THE
AFTERNOON HOURS. BREEZY TO WINDY CONDITIONS WILL ALSO DEVELOP BY
AFTERNOON...ESPECIALLY FROM THE COLORADO RIVER VALLEY WESTWARD. MUCH
COOLER AND VERY MOIST AND UNSETTLED CONDITIONS ARE EXPECTED THIS
WEEKEND AS THE AFOREMENTIONED PACIFIC LOW MOVES EASTWARD AND ACROSS
THE AREA...BRINGING PERIODS OF RAIN OR RAIN SHOWERS TO BOTH THE
DESERTS AND HIGHER TERRAIN...BEGINNING FRIDAY NIGHT AND CONTINUING
ALL THE WAY INTO SUNDAY. BREEZY CONDITIONS WILL ACCOMPANY THIS
PASSING SYSTEM BOTH SATURDAY AND SUNDAY. ON MONDAY...A SOMEWHAT
DRIER NORTHWEST FLOW ALOFT WILL BUILD INTO THE AREA BEHIND THE
EXITING LOW PRESSURE SYSTEM...LEADING TO LESS WIND AND SLIGHT
WARMING WHICH WILL BRING HIGH TEMPERATURES BACK TOWARDS SEASONAL
NORMALS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
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DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...PERCHA
AVIATION...CB
FIRE WEATHER...CB
AREA FORECAST DISCUSSION
NWS TUCSON AZ
215 PM MST TUE FEB 25 2014
.SYNOPSIS...VARIABLE CLOUDS WITH A FEW SPRINKLES OR LIGHT SHOWERS
POSSIBLE INTO WEDNESDAY. A FEW MOUNTAIN SHOWERS POSSIBLE THURSDAY AS
A SYSTEM BRUSHES BY TO OUR NORTH. THEN...A STRONGER...WETTER AND
COOLER PACIFIC STORM SYSTEM WILL BRING GUSTY WINDS FRIDAY AND
SATURDAY WITH VALLEY RAIN AND MOUNTAIN SNOW OVER THE WEEKEND...ALONG
WITH MUCH COOLER TEMPERATURES.
&&
.DISCUSSION...INCREASING MID AND UPPER LEVEL MOISTURE IN SOUTHERLY
TO SOUTHWESTERLY FLOW HAS BROUGHT VIRGA AND SPRINKLES TO THE AREA
EARLY THIS AFTERNOON. SOUTHERLY TO SOUTHWESTERLY FLOW HAS PUSHED THE
PRECIPITABLE WATER UP TO AROUND .6 WITH .8 VALUES CREEPING INTO
NORTHERN SONORA. HRRR CONTINUES TO FOCUS BEST CHANCE OF MEASURABLE
PRECIP ACROSS SOUTHERN AREAS. VERY LIGHT QPF VALUES BUT SPRINKLES TO
LIGHT SHOWERS WILL BECOME MORE COMMON LATER THIS AFTERNOON AND
EVENING.
PARTIAL CLEARING FROM THE WEST IN THE EARLY MORNING HOURS...BUT WE
COULD STILL SEE A FEW SPRINKLES WEDNESDAY AS SOME MID LEVEL MOISTURE
REMAINS IN PLACE.
LATEST MODEL SUITES...ENSEMBLE MEANS AND MEASURE OF PREDICTABILITY
GREATLY INCREASING FOR THE WEEKEND SYSTEM. WE`LL START OUT WITH
GUSTY WINDS AND POTENTIAL BLOWING DUST ISSUES FRIDAY AFTERNOON AHEAD
OF THE SYSTEM.
SOME TIMING ISSUES BUT DECENT DYNAMICS AND ROBUST MOISTURE FIELDS
FROM A STRONG AND COOL PACIFIC STORM IS EXPECTED TO BRING OUR BEST
CHANCE OF SIGNIFICANT RAINFALL SINCE MID DECEMBER. ACTUALLY THIS
STORM LOOKS WETTER THAN THE DECEMBER STORMS...PERHAPS AS HEAVY AS
THE WET NOVEMBER SYSTEMS. STRONG UPSLOPE SHOULD INITIATE LIGHTER
SHOWER ACTIVITY EARLY SATURDAY. INITIAL IMPULSE LIFTS THROUGH
SATURDAY AFTERNOON FOLLOWED QUICKLY BY REINFORCING ENERGY SATURDAY
NIGHT. THE TRAJECTORY OF THIS REINFORCING ENERGY IS CURRENTLY
EXPECTED TO BULLSEYE SOUTHEAST ARIZONA SATURDAY NIGHT INTO SUNDAY
MORNING. IT`S EARLY BUT WE`LL LIKELY END UP WITH SOME WINTER
HEADLINES IN THE MOUNTAINS FOR EXCESSIVE SNOWFALL. SNOW LEVELS
FALLING TOWARD THE 6500 FT LEVEL SATURDAY NIGHT. EARLIEST ESTIMATES
OF QPF VALUES IN EXCESS OF 1/2 INCH IN VALLEYS WITH POTENTIAL OVER
AN INCH IN SOME LOCATIONS. HIGH CONFIDENCE FOR POP FORECAST WITH 70
IN VALLEYS AND 100 IN MOUNTAINS...BUT STILL MEDIUM CONFIDENCE FOR
HEAVY QPF VALUES.
&&
.AVIATION...FORECAST PERIOD THROUGH 27/00Z.
BKN-OVC CLOUDS AOA 10K FT AGL WILL CONTINUE ACROSS SE AZ THROUGH
26/09Z WITH PARTIAL CLEARING WED MORNING. SCT 6-8K FT ABOVE VALLEY
FLOORS AND OBSCURED MT TOPS IN ISOLD -SHRA ARE MOST LIKELY BTWN
26/00Z AND 26/06Z. SURFACE WIND GENERALLY LESS THAN 10 KTS THRU
26/21Z ALTHOUGH GUSTS 15-20 KTS PSBL NEAR -SHRA. WESTERLY WINDS
10-15KT WED AFT 26/21Z. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...SEVERAL DISTURBANCES WILL MOVE ACROSS THE REGION
OVER THE NEXT WEEK. THE FIRST TWO MAY BRING LIGHT SHOWERS THIS
EVENING INTO THURSDAY. ASSOCIATED PERIODS OF CLOUD COVER WILL KEEP
DAYTIME TEMPERATURES COOLER THAN OF LATE...ALTHOUGH THEY WILL REMAIN
ABOVE NORMAL. NIGHTTIME TEMPERATURES WILL ALSO BE ABOVE NORMAL THE
NEXT FEW NIGHTS.
WIDESPREAD SIGNIFICANT PRECIPITATION IS NOT EXPECTED UNTIL A
STRONGER PACIFIC STORM SYSTEM APPROACHES SOUTHERN ARIZONA LATE THIS
WEEK WITH THE BEST CHANCE FOR PRECIPITATION LOOKING LIKE SATURDAY.
BREEZY TO WINDY CONDITIONS ARE FORECAST IN ADVANCE OF THIS SYSTEM
FROM THURSDAY THROUGH SATURDAY AND COOLER TEMPERATURES WILL
ACCOMPANY THE PRECIPITATION THIS WEEKEND.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
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MEYER/DROZD
AREA FORECAST DISCUSSION
NWS TUCSON AZ
925 AM MST TUE FEB 25 2014
.SYNOPSIS...A PLUME OF TROPICAL MOISTURE WILL BRING AREAS OF LIGHT
SHOWERS OR SPRINKLES TO PARTS OF SOUTHEAST ARIZONA INTO WEDNESDAY.
IT WILL ALSO BE COOLER TODAY...ESPECIALLY FOR ANY AREAS THAT SEE THE
LIGHT PRECIPITATION. A FEW MOUNTAIN SHOWERS POSSIBLE THURSDAY AS A
SYSTEM BRUSHES BY TO OUR NORTH. THEN...A STRONGER AND COOLER PACIFIC
STORM SYSTEM WILL BRING VALLEY RAIN AND MOUNTAIN SNOW...MUCH COOLER
TEMPERATURES AND GUSTY WINDS THIS WEEKEND.
&&
.DISCUSSION...INCREASING MID AND UPPER LEVEL MOISTURE IN SOUTHERLY
TO SOUTHWESTERLY FLOW THIS MORNING. 12Z KTWC SOUNDING HAD A
PRECIPITABLE WATER OF .47 INCHES BUT LATEST BLENDED SATELLITE TRENDS
ARE OVER .5 WITH 1 INCH VALUES DOWN AROUND HERMOSILLO. WITH THE
UPWARD TREND EXPECTED TO CONTINUE WE WILL LIKELY APPROACH 3/4 OF
AN INCH LATER TODAY AND THIS EVENING. VERY LIGHT QPF VALUES BUT
SPRINKLES TO VERY LIGHT SHOWERS WILL BE COMMON AFTER 1 PM OR SO.
LATEST HRRR REFLECTS THIS WELL AND CURRENT FORECAST HANDLES THINGS
FINE. TEMPERATURE COLUMN SUPPORTS ANOTHER 80 TODAY BUT WITH THE
MOISTURE INCREASE AND LACK OF SOLAR INSOLATION SOMETHING IN THE
LOWER 70S IS MORE LIKELY.
LATEST MODEL TRENDS GREATLY INCREASING CONFIDENCE FOR WEEKEND
SYSTEM. 12Z NAM DOVETAILS NICELY INTO STRONG SYSTEM FOR OUR AREA
OVER THE WEEKEND ON 00Z ECMWF TRENDS. NEW GFS HAS A MORE SIGNIFICANT
MOISTURE FIELD FOR OUR PART OF THE STATE. WE WILL LIKELY HIT THE
WEEKEND FORECAST HARDER WITH THE AFTERNOON PACKAGE.
&&
.PREV DISCUSSION...FORECAST PROBLEMS FOR TODAY WILL BE THE POTENTIAL
FOR MEASURABLE RAIN AND HIGHS THIS AFTERNOON. SATELLITE IMAGERY THIS
MORNING SHOWED A SIGNIFICANT BATCH OF TROPICAL MOISTURE APPROACHING
THE AREA FROM THE SW. THIS MOISTURE WILL OVERSPREAD THE AREA THIS
MORNING. THE WEAK DISTURBANCE SEEN WELL OFF THE NRN BAJA COAST THIS
MORNING WILL MOVE ACROSS SRN AZ/NRN SONORA THIS AFTERNOON INTO THIS
EVENING. THE WEAK DYNAMICS ASSOCIATED WITH THIS DISTURBANCE WILL
PRODUCE LOTS OF VIRGA... SPRINKLES AND LIGHT MEASURABLE SHOWERS. QPF
VALUES WILL BE RATHER LIGHT...MOSTLY LESS THAN 0.05". COULD SEE UP
TO A TENTH IN THE HUACHUCAS AND CHIRICAHUAS. BEST CHANCES FOR
MEASURABLE WILL BE FROM TUCSON SOUTH AND EAST. THE OTHER MAIN
FORECAST PROBLEM OF THE DAY IS TEMPERATURES. LATEST MOS GUIDANCE
ALONG WITH 850-700 MB THICKNESS NUMBERS SUGGEST MUCH COOLER THAN
CURRENT FORECAST ESPECIALLY IN AREAS THAT WILL HAVE LOTS OF CLOUD
COVER AND LIGHT SHOWERS. THE LAST FIVE MOS GUIDANCE RUNS FROM GFS
MODEL HAVE BEEN GOING COOLER WITH EACH RUN. HAVE TO TAKE THAT IS
CONSIDERATION BUT NOT GO AS COLD AS THE GFS IS SUGGESTING THIS
AFTERNOON. FOR EXAMPLE 68 FOR TUCSON AND 66 FOR DOUGLAS. DECIDED TO
CUT HIGHS 4-8 DEGREES FROM INHERITED FORECAST IN AREAS WHERE PRECIP
IS POSSIBLE. WARM NATURE OF THIS MOISTURE WILL KEEP SNOW LEVELS
ABOVE MOUNTAIN PEAKS. LOT TO SAY FOR A LIGHT PRECIP EVENT...BUT ITS
BEEN AWHILE.
NEXT TROF WILL PASS THROUGH THE STATE ON THURSDAY...BRINGING A
SLIGHT CHANCE OF SHOWERS TO THE EAST CENTRAL MOUNTAINS.
SLIGHTLY WARMER FRIDAY AS SHORT WAVE RIDGE PASSES THROUGH IN ADVANCE
OF STRONGER PACIFIC STORM. THIS STORM WILL IMPACT THE AREA THIS
WEEKEND WITH WIDESPREAD VALLEY RAIN AND MOUNTAIN SNOW. AT THIS TIME
LOOKS LIKE SNOW LEVELS COULD BE AS LOW AS THE 6500-7000 FOOT LEVEL
WITH SIGNIFICANT AMOUNTS LIKELY. QPF VALUES COULD BE IN THE 0.20" TO
0.75" RANGE IN THE VALLEYS AND OVER AN INCH IN THE MOUNTAINS. STAY
TUNED AS THIS GETS FINE TUNED AS THE WEEK PROGRESSES. HIGHS THIS
WEEKEND WILL BE MUCH COOLER WITH HIGHS ON SATURDAY 8-11 DEGREES
COOLER THAN FRIDAY AND THEY WILL BE BELOW NORMAL FOR THE FIRST SINCE
THE FIRST 7 DAYS OF FEBRUARY.
&&
.AVIATION...FORECAST PERIOD THROUGH 26/18Z.
BKN-OVC CLOUDS AOA 10K FT AGL WILL CONTINUE ACROSS SE AZ THROUGH
26/09Z WITH PARTIAL CLEARING WED MORNING. SCT 6-8K FT ABOVE VALLEY
FLOORS AND OBSCURED MT TOPS IN ISOLD -SHRA ARE MOST LIKELY BTWN
25/21Z AND 26/06Z. SURFACE WIND GENERALLY LESS THAN 10 KTS THRU
26/18Z ALTHOUGH GUSTS 15-20 KTS PSBL NEAR -SHRA. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...SEVERAL DISTURBANCES WILL MOVE ACROSS THE REGION
OVER THE NEXT WEEK. THE FIRST TWO MAY BRING LIGHT SHOWERS TODAY INTO
THURSDAY. ASSOCIATED PERIODS OF CLOUD COVER WILL KEEP DAYTIME
TEMPERATURES COOLER THAN OF LATE...ALTHOUGH THEY WILL REMAIN ABOVE
NORMAL. NIGHTTIME TEMPERATURES WILL ALSO BE ABOVE NORMAL THE NEXT
FEW NIGHTS.
WIDESPREAD SIGNIFICANT PRECIPITATION IS NOT EXPECTED UNTIL A
STRONGER PACIFIC STORM SYSTEM APPROACHES SOUTHERN ARIZONA LATE THIS
WEEK WITH THE BEST CHANCE FOR PRECIPITATION LOOKING LIKE SATURDAY.
BREEZY CONDITIONS ARE FORECAST IN ADVANCE OF THIS SYSTEM FROM
THURSDAY THROUGH SATURDAY AND COOLER TEMPERATURES WILL ACCOMPANY
THE PRECIPITATION THIS WEEKEND.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
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MEYER/DROZD
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
910 AM MST TUE FEB 25 2014
.SYNOPSIS...
DRY WESTERLY FLOW IS EXPECTED TO CONTINUE INTO EARLY FRIDAY ACROSS
THE REGION...KEEPING TEMPERATURES ABOVE NORMAL...RISING INTO THE
UPPER 70S TO LOW 80S EACH DAY ACROSS THE LOWER DESERTS...WITH
PERIODS OF HIGH CLOUDS PASSING OVERHEAD FROM TIME TO TIME. A
DRAMATIC CHANGE IN THE WEATHER IS THEN EXPECTED FROM LATE FRIDAY
INTO THE UPCOMING WEEKEND AS A VERY STRONG...AND WET PACIFIC STORM
MOVES INTO THE DESERT SOUTHWEST. THIS STORM IS EXPECTED TO BRING
WIDESPREAD SIGNIFICANT RAINFALL...AND MUCH COOLER TEMPERATURES TO
THE REGION.
&&
.DISCUSSION...
SUBTROPICAL MOISTURE IN THE FORM OF MID AND HIGH CLOUDS CONTINUES TO
STREAM NORTHEASTWARD ACROSS SOUTHERN AZ AHEAD OF A WEAK VORT MAX
NEAR PUERTO PENASCO. LATEST RADAR IMAGERY SHOWS SOME WEAK ECHOES
ACROSS SE AZ AND HI-RES WRF GUIDANCE ALONG WITH THE HRRR SUGGEST
SPRINKLES MAY CLIP PORTIONS OF EASTERN MARICOPA...PINAL AND SOUTHERN
GILA COUNTIES. FORECAST HAS BEEN UPDATED THIS MORNING TO INCREASE
CLOUD COVER AND ADD THE MENTION OF SLIGHT CHANCE SPRINKLES THROUGH
LATE THIS AFTERNOON. OTHERWISE...THE FORECAST REMAIN IN GOOD SHAPE.
&&
.PREVIOUS DISCUSSION...
TODAY THROUGH WEDNESDAY NIGHT...
DRY WESTERLY FLOW ALOFT WILL CONTINUE OVER THE REGION RESULTING IN A
CONTINUATION OF UNSEASONABLY WARM TEMPERATURES ALONG WITH PERIODS OF
HIGH CLOUDS FROM TIME-TO-TIME...AND LIGHT WINDS.
THURSDAY...
MODELS CONTINUE TO BRING A WEAK SHORTWAVE EASTWARD INTO THE GREAT
BASIN/4-CORNERS REGION DURING THE DAY ON THURSDAY. ALTHOUGH THE
LATEST MODEL RUNS STILL KEEP MOST OF THE MOISTURE AND DYNAMICS WELL
TO OUR NORTH...THE LATEST GEM AND EURO MODEL SUITES NOW ARE
FORECASTING A SLIGHT CHANCE FOR SPRINKLES...OR LIGHT SHOWERS OVER
THE HIGHEST ELEVATIONS OF SOUTHERN GILA COUNTY...AS THE CLOUD BASES
LOWER TO AROUND...OR JUST BELOW 10K FEET BRIEFLY ON THURSDAY.
THUS...HAVE INCREASED POPS OVER THAT REGION INTO THE SLIGHT CHANCE
RANGE TO REFLECT THESE CHANGES. HOWEVER...IT STILL APPEARS THAT THE
MAIN IMPACTS FROM THIS SYSTEM WILL BE ONLY TO BRING GUSTY WINDS TO
SOUTHEAST CA WEDNESDAY AFTERNOON AND EVENING...AND TO INCREASE
CLOUDINESS OVER THE REGION.
FRIDAY AND SATURDAY...
IT NOW APPEARS THAT IT IS ALMOST CERTAIN THAT WE WILL SEE A MAJOR
CHANCE IN THE WEATHER FROM FRIDAY ONWARD INTO THE UPCOMING WEEKEND.
IN FACT...ALL OF THE LATEST MODEL RUNS ARE EVEN MORE BULLISH WITH
THIS SYSTEM THEN THEY WERE ON PREVIOUS RUNS. THERE IS NOW EXCELLENT
AGREEMENT BETWEEN THE EURO...GFS...AND GEM THAT THIS SYSTEM...WHICH
IS NOW TRACKING EASTWARD ACROSS THE CENTRAL PACIFIC SOUTH OF THE
ALEUTIAN CHAIN...WILL NOW PICK UP COPIOUS AMOUNTS OF MOISTURE AS IT
INTERACTS WITH A VERY STRONG (180KT) PACIFIC JET THAT EXTENDS ALL
THE WAY EASTWARD FROM SOUTHERN JAPAN (130E) TO NORTHEAST OF HAWAII
(ABOUT 150W). ALL THREE MODELS NOW PUSH THE SYSTEM INLAND
EARLIER...INTO SOUTHERN CA BY FRIDAY MORNING...THEN SLOWLY ACROSS
OUR CWA FROM LATE FRIDAY INTO EARLY SUNDAY. LATEST GFS PWAT
FORECASTS NOW PUSH A PLUME OF 1 INCH OR GREATER PWATS INTO...AND
ACROSS OUR CWA LATE FRIDAY AND SATURDAY. BOTH THE GFS AND EURO
FORECAST SOUNDINGS FOR KPHX ARE NOW SHOWING A VERY DEEP NEARLY
SATURATED MOISTURE LAYER...ALL THE WAY FROM THE SFC TO 35K FEET
MOVING IN ON SATURDAY...WITH STRONG SW-LY WINDS THROUGH THE ENTIRE
COLUMN...SOMETHING WE DON/T SEE VERY OFTEN AROUND HERE.
ALL THREE MODELS HAVE ALSO GREATLY INCREASED THEIR QPF FORECASTS.
THEY NOW ARE FORECASTING STORM TOTAL RAINFALL AMOUNTS OF 0.25-0.50
OF AN INCH FOR THE LOWER ELEVATIONS OF SE CA AND SW AZ...0.75-1.25
INCH FOR JOSHUA TREE NB AND ACROSS THE LOWER ELEVATIONS OF
SOUTH-CENTRAL ARIZONA...AND 1 TO 2 INCHES ACROSS THE HIGHER TERRAIN
OF SOUTH-CENTRAL ARIZONA. ALTHOUGH WIDESPREAD HYDRO ISSUES ARE VERY
UNLIKELY...DUE TO THE VERY DRY ANTECEDENT CONDITIONS...THERE WOULD
BE LIKELY SOME SMALL STREAM AND URBAN FLOODING ISSUES IF THESE
RAINFALL AMOUNTS DUE VERIFY.
BASED ON THESE UPDATED FORECAST...I HAVE GREATLY INCREASED POPS
ACROSS OUR WESTERN ZONES LATE FRIDAY AND PUSHED POPS INTO THE LIKELY
TO CATEGORICAL RANGE FOR MUCH OF OUR CWA ON SATURDAY. IN
ADDITION...I HAVE LOWERED HIGH TEMPS FURTHER ACROSS SOUTH-CENTRAL
ARIZONA ON SATURDAY...INTO THE LOW TO MID 60S AS THE LIKELY STEADY
RAIN AND THICK CLOUD COVER SHOULD KEEP TEMPS WELL BELOW NORMAL...A
RATHER RAW AND WET DAY FOR A VERY BUSY SLATE OF OUTDOOR ACTIVITIES
THAT ARE PLANNED ACROSS THE GREATER PHX AREA. ON THE OTHER
HAND...SNOWFALL CONCERNS ACROSS OUR CWA APPEAR TO BE A
NON-ISSUE...AS THE SUBTROPICAL ORIGIN OF THE AIRMASS IS EXPECTED TO
KEEP SNOW LEVELS MAINLY AOA 7000FT. AHEAD OF THE SYSTEM...WE ALSO
NOW EXPECT STRONG SOUTH TO SOUTHWESTERLY WINDS ON FRIDAY AFTERNOON
ACROSS SOUTHEAST CA AND THE LOWER CO RIVER VALLEY...WITH WIND SPEEDS
APPROACHING ADVISORY CRITERIA AT SOME LOCATIONS.
SUNDAY THROUGH TUESDAY...
SOME LINGERING SHOWERS ARE LIKELY ON SUNDAY...AND MAYBE EVEN INTO
MONDAY ACROSS SOUTH-CENTRAL ARIZONA AS GENERAL TROUGHINESS HANGS
BACK OVER OUR REGION...BUT FURTHER SIGNIFICANT RAINFALL IS NOW
EXPECTED AT THIS TIME. NEXT TUESDAY SHOULD SEE WARMER...AND DRIER
CONDITIONS AS RIDGING ATTEMPTS TO REBUILD BACK OVER THE DESERT
SOUTHWEST.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
CONTINUED HIGH PRESSURE ALOFT TODAY INTO WEDNESDAY...HOWEVER IT WILL
BE A DIRTY RIDGE ALLOWING CONSIDERABLE MID/HI CLOUDS TO OVERSPREAD
THE TERMINALS. EXPECT SCT-BKN MID AND HI LEVEL DECKS FROM 12K FEET
ON UP NEXT 24 HOURS...WITH THE DEEPEST MOISTURE ACROSS THE CENTRAL
AZ DESERT TAF SITES. WINDS TO REMAIN QUITE LIGHT AND VARIABLE WITH
WEAK DIURNAL SIGNALS AT KIWA AND KPHX TODAY AND TONIGHT. NO AVIATION
CONCERNS NEXT 24 HOURS AT ANY AIRFIELD.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
A FAST MOVING DISTURBANCE PASSING BY TO THE NORTH WILL LEAD TO
AFTERNOON BREEZY CONDITIONS THURSDAY...AND CAUSE HUMIDITIES TO
BECOME ELEVATED WITH MOST DESERTS CLIMBING ABOVE 20 PERCENT.
OTHERWISE HIGH TEMPERATURES WILL STAY ABOVE SEASONAL NORMALS. HIGH
PRESSURE ALOFT WILL BRIEFLY RETURN FRIDAY FOR CONTINUED ABOVE NORMAL
HIGH TEMPERATURES...HOWEVER MOISTURE WILL INCREASE FROM THE WEST
AHEAD OF AN APPROACHING WET PACIFIC LOW PRESSURE SYSTEM...AND A
CHANCE OF SHOWERS WILL DEVELOP ACROSS THE WESTERN DESERTS DURING THE
AFTERNOON HOURS. BREEZY TO WINDY CONDITIONS WILL ALSO DEVELOP BY
AFTERNOON...ESPECIALLY FROM THE COLORADO RIVER VALLEY WESTWARD. MUCH
COOLER AND VERY MOIST AND UNSETTLED CONDITIONS ARE EXPECTED THIS
WEEKEND AS THE AFOREMENTIONED PACIFIC LOW MOVES EASTWARD AND ACROSS
THE AREA...BRINGING PERIODS OF RAIN OR RAIN SHOWERS TO BOTH THE
DESERTS AND HIGHER TERRAIN...BEGINNING FRIDAY NIGHT AND CONTINUING
ALL THE WAY INTO SUNDAY. BREEZY CONDITIONS WILL ACCOMPANY THIS
PASSING SYSTEM BOTH SATURDAY AND SUNDAY. ON MONDAY...A SOMEWHAT
DRIER NORTHWEST FLOW ALOFT WILL BUILD INTO THE AREA BEHIND THE
EXITING LOW PRESSURE SYSTEM...LEADING TO LESS WIND AND SLIGHT
WARMING WHICH WILL BRING HIGH TEMPERATURES BACK TOWARDS SEASONAL
NORMALS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...PERCHA
AVIATION...CB
FIRE WEATHER...CB
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
252 PM MST TUE FEB 25 2014
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT)
ISSUED AT 252 PM MST TUE FEB 25 2014
SHORT TERM FORECAST THROUGH THIS EVENING IS BASED ON RAP MODEL TRENDS
THAT SNOW WILL EXPAND SOUTHWARD OVER ROUTT COUNTY EARLY THIS
AFTERNOON. AS OF 21Z...STEAMBOAT LAKE WEB CAM INDICATE THAT SNOW
HAS REACHED HAHNS PEAK VICINITY...BUT NO MOUNTAIN TOP OBSCURATION
NEAR STEAMBOAT SPRINGS. EXPECT THIS TO CHANGE WITHIN THE NEXT
COUPLE OF HOURS AS LEADING EDGE OF BAROCLINIC ZONE AND DECENT
GRADIENT NORTHWEST FLOW LEADS TO OROGRAPHIC SNOW OVER THE MT
ZIRKEL WILDERNESS AREA AND THE PARK RANGE. RAP MODEL INDICATES
RAIN/SNOW BAND MAY EXTEND AS FAR WEST AS MAYBELL AND MEEKER LATE
THIS AFTERNOON AS THE MOISTURE BAND SLIDES SOUTH AND EAST.
PRIMARY CONCERN IS THAT THE AMPLIFYING UPSTREAM RIDGE AXIS HAS
PINCHED OFF THE PACIFIC MOISTURE STREAM INTO NORTHWEST COLORADO...
THIS IS EVIDENT ON THE SATELLITE IMAGES. NOT SURE WHETHER THE
FORECASTED SNOW AMOUNTS FOR THE PARK RANGE WILL REACH THE UPPER
RANGE OF AROUND 7 INCHES...BUT RAP QPF STILL INDICATE THAT A FEW
INCHES OF SNOW REMAIN POSSIBLE. WITH SNOW OBSERVED AT RIVERTON
AND LANDER IN WEST CENTRAL WYOMING...GIVING CREDENCE THAT THE SNOW
IS ON THE WAY. LESSER AMOUNTS OF SNOW IS ANTICIPATED FOR THE FLAT
TOP MOUNTAINS AND GORE RANGE (VAIL PASS)...DO NOT THINK THAT AN
EXPANSION OF THE WINTER WEATHER ADVISORY IS NECESSARY. MOISTURE
STREAM SLIDES EAST AFTER MIDNIGHT WITH MID LEVEL DRY STABLE AIR
ADVECTING INTO NORTHWEST COLORADO...THIS WILL SHUT DOWN OROGRAPHIC
SNOW FAIRLY QUICKLY LATE TONIGHT.
FOR THE SERN HALF OF THE FORECAST AREA THROUGH TONIGHT...CLEAR AND
DRY WEATHER IS EXPECTED FOR THE NEXT 12 TO 18 HOURS.
WEST COAST RIDGE SHIFTS INLAND ON WEDNESDAY BUT BROAD ISENTROPIC
UPGLIDE WILL RESULT IN AN INCREASE OF MID/HIGH LEVEL CLOUDS FROM
THE SOUTHWEST. NAM AND GFS SHOWING HINTS OF MOUNTAIN TOP SPOTTY
SNOW WEDNESDAY AFTERNOON AND NIGHT. SOMETIMES THIS IS OVERDONE BUT
THE TREND WILL BE FOR INCREASING CLOUDS WITH CIRROSTRATUS EVOLVING
INTO ALTOSTRATUS. WITH THE INCREASED CLOUD COVER...EXPECT
RELATIVELY MILD CONDITIONS WEDNESDAY NIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 252 PM MST TUE FEB 25 2014
THE FORECAST AREA COMES UNDER THE INFLUENCE OF THE SUBTROPICAL JET
THROUGH THE WEEKEND. THIS TYPICALLY BRINGS BETTER MOISTURE BUT
MILDER TEMPERATURES WITH ASSOCIATED STORMS. BREEZY TO WINDY
CONDITIONS ARE EXPECTED IN THE MTNS AND HIGH VALLEYS...INTO THE
LOWER VALLEYS WITH SHOWERS.
THURSDAY...A TRANSIENT RIDGE PASSES IN THE EARLY AFTERNOON WITH
DEEPENING MOISTURE IN SW FLOW. 700MB SPECIFIC HUMIDITIES CLIMB TO
4 G/KG IN THE AFTERNOON. THERE IS SOME MODEL DISAGREEMENT ON
TEMPERATURES AND SNOW LEVELS. A COMPROMISE PUTS THE SNOW LEVELS
AROUND 7500FT/8500FT NORTH/SOUTH. THE DEEPEST MOISTURE IS IN THE
SOUTHERN-CENTRAL MTNS. MARGINAL INSTABILITY PRODUCES AREAS OF
STRONGER SHOWERS AND BRIEFLY LOWER SNOW LEVELS.
THURSDAY NIGHT...THE BEST FORCING OCCURS AS THE SUBTROPICAL JET
PUSHES INTO THE SOUTH THEN LIFTS INTO THE CENTRAL ZONES. SNOW
LEVELS LOWER INTO THE NORTHERN VALLEYS...TO 7500FT SOUTH.
FRIDAY IS A BRIEF BREAK UNDER AS A LOCAL RIDGE IS AMPLIFIED AHEAD
OF THE NEXT STRONG STORM BRINGING WARM ADVECTION. MOISTURE REMAINS
AT 4 G/KG SO SHOWERS INCREASE INTO THE AFTERNOON.
FRIDAY NIGHT-SATURDAY NIGHT...THE NEXT SUBTROPICAL JET STREAK LIFTS
THE EASTERN UTAH FRIDAY NIGHT THEN ACROSS WESTERN COLORADO ON
SATURDAY. AGAIN THERE IS A CONVECTIVE COMPONENT FRIDAY NIGHT INTO
SATURDAY. THERE IS AGAIN A CONVECTIVE COMPONENT TO THIS STORM.
SNOWFALL WILL FAVOR THE SOUTHERN AND CENTRAL MTNS. SNOW LEVELS
AROUND 7000FT. SATURDAY NIGHT IS TROUGH PASSAGE WITH NW FLOW
DEVELOPING. SNOW LEVEL DROPS TO AROUND 5000FT BUT WILL FAVOR THE
NW-FACING SLOPES OF THE COLORADO MTNS.
SUNDAY-TUESDAY...ARE NOW A FLAT ZONAL FLOW WITH THE POLAR FRONT
JET SETTLING INTO WYOMING THEN RAKING THE NORTH ON MONDAY. EXPECT
COOLER TEMPERATURES THROUGH THESE PERIODS WITH THE BEST SNOWFALL
FAVORING THE NORTHERN MTNS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 252 PM MST TUE FEB 25 2014
VFR PREVAILS AT ALL TAF SITES THROUGH THE PERIOD. THERE IS A 10 TO 20
PERCENT CHANCE OF -SN AT KASE AND KEGE BETWEEN 00Z AND 12Z
TONIGHT.
WIDESPREAD LIGHT SNOW IS EXPECTED EAST OF A LINE FROM DWX-KSBS-10E
KEGE-10E KASE FROM 20Z THIS AFTERNOON THROUGH 06Z THIS EVENING.
EXPECT MOUNTAIN OBSCURATIONS WITH LOW CIGS/VIS FROM LIGHT SNOW AND
FOG. SLOW IMPROVEMENT IS EXPECTED AFTER 06Z WITH NO MOUNTAIN
OBSCURATIONS AFTER 15Z.
MID/HIGH LEVEL CLOUDS INCREASE ON WEDNESDAY WITH ISOLATED MOUNTAIN
TOP FLURRIES. THIS SHOULD HAVE NO IMPACT AT MOUNTAIN AIRPORT
SITES.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 8 AM MST WEDNESDAY ABOVE 9000 FEET
FOR THE COZ004.
UT...NONE.
&&
$$
SHORT TERM...PF
LONG TERM...JOE
AVIATION...PF
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1032 PM MST MON FEB 24 2014
.UPDATE...
ISSUED AT 520 PM MST MON FEB 24 2014
UPDATED FORECAST TO END RED FLAG WARNING AND BLOWING DUST
ADVISORIES. ALSO BUMPED UP TIMING OF FRONT INTO SOUTHEAST COLORADO
TRENDING FORECAST TOWARDS THE FASTER HRRR. GUSTS IN NORTHEAST
COLORADO ARE AROUND 30-40KTS BEHIND THE FRONT...AND TEMPERATURES ARE IN
THE UPPER 20S. HRRR BRINGS THE FRONT THROUGH MOST OF SOUTHEAST
COLORADO BY 03Z...AND SHOULD BRING A STARK CHANGE ONCE IT BLOWS
THROUGH. GRIDS ATTEMPT TO FINE TUNE THESE DETAILS BETTER. -KT
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 252 PM MST MON FEB 24 2014
CURRENTLY...WESTERLY FLOW HAS ALLOWED FOR STRONG MIXING THIS
AFTERNOON ACROSS THE I-25 CORRIDOR. THIS HAS HELP TEMPERATURES RISE
INTO THE UPPER 60S TO LOWER 70S. WINDS ARE GUSTY...WITH GUSTS 25 TO
35 KTS SO FAR...ESPECIALLY OVER THE SOUTHERN I-25 CORRIDOR.
HUMIDITY VALUES ARE ALSO RUNNING AROUND 10 PERCENT AND EXTREME FIRE
DANGER IS PRESENT. HAVE NOT SEEN ANY REPORTS OF BLOWING DUST YET
BUT THERE WILL LIKELY BE SOME IN WIND PRONE AREAS...FROM PUEBLO TO
TRINIDAD. FURTHER EAST...CLOUDS AND LIGHT EASTERLY FLOW HAVE HELD
TEMPERATURES DOWN THIS AFTERNOON...WITH MID 40S FOR LA JUNTA AND
LAMAR. HOW WARM IT GETS DOWN THE FAR EASTERN ARKANSAS RIVER BASIN
WILL DEPEND ON CLEARING AND HOW FAR WESTERLIES PUSH THE WARMER AIR.
TONIGHT...A STRONG COLD FRONT CURRENTLY ENTERING NORTHERN COLORADO
WILL PROGRESS QUICKLY SOUTH ACROSS THE EASTERN PLAINS THIS EVENING.
EXPECT BREEZY NORTH WINDS BEHIND THE FRONT WHICH WILL ADVECT COLD
AIR INTO THE REGION. EXPECT TEMPERATURES TO FALL RAPIDLY BEHIND THE
FRONT. ONCE THE FRONT PASSES...EXPECT LOW LEVEL FLOW TO SWING
SOUTHEASTERLY. THIS WILL ALLOW LOW STRATUS AND FOG TO DEVELOP OVER
PORTIONS OF THE EASTERN PLAINS LATE TONIGHT INTO TUESDAY MORNING.
WHILE THE AIR MASS IS SHALLOW...PATCHY AREAS OF FREEZING DRIZZLE CAN
NOT BE RULED OUT AS WELL. ANY FOG OR FREEZING DRIZZLE COULD HAMPER
DRIVING CONDITIONS ACROSS EL PASO COUNTY...AND DOWN THE ARKANSAS
RIVER BASIN FOR TUESDAY MORNINGS COMMUTE. LIGHT SNOW IS EXPECTED TO
MOVE INTO THE CENTRAL MOUNTAINS AFTER MIDNIGHT WITH A QUICK INCH
POSSIBLE BY TUESDAY MORNING.
TUESDAY...THE MAIN FORECAST CHALLENGE WILL BE TEMPERATURES. HAVE
TRENDED AFTERNOON HIGHS DOWN WITH MOST AREAS STRUGGLING TO MAKE IT
OUT OF THE 30S ACROSS THE EASTERN PLAINS. THE EXCEPTION WILL LIKELY
BE THE LEE SLOPES OF THE EASTERN MOUNTAINS...WHERE SOME AFTERNOON
MIXING AND CLEARING OF CLOUD COVER WILL HELP BOOST HIGHS INTO THE
40S. IF CLOUDS CAN CLEAR...AND WE SEE BETTER AFTERNOON MIXING THAN
IS ANTICIPATED...AREAS OVER THE PLAINS COULD BE A BIT WARMER. BY
THE LATE AFTERNOON...ANOTHER COLD FRONT WILL PUSH SOUTH INTO EASTERN
COLORADO. ALL MODELS DEVELOP LIGHT PRECIPITATION ACROSS THE PALMER
DIVIDE BY MID AFTERNOON...AND SPREAD IT SOUTH INTO THE HIGHWAY 50
CORRIDOR BY SUNSET. AREAS OVER TELLER COUNTY WILL LIKELY SEE AN
INCH OR SO OF SNOW DURING THE LATE AFTERNOON. SNOW WILL BE LIGHT
OVER THE CENTRAL MOUNTAINS DURING THE MORNING HOURS AND PICK UP IN
INTENSITY DURING THE AFTERNOON. AN ADDITIONAL 1 TO 3 INCHES ARE
POSSIBLE BY TUESDAY EVENING FOR THE CENTRAL MOUNTAINS. MOZLEY
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 252 PM MST MON FEB 24 2014
...WEEKEND STORM STILL LOOKS GOOD...ESPECIALLY FOR THE CONTDVD...
TUESDAY NIGHT...
DISTURBANCE WILL BE MOVING ACROSS THE AREA AND WILL LIKELY BRING
SOME LIGHT SNOW TO AREAS GENERALLY NORTH OF A LINE FROM SALIDA TO
PUEBLO TO LAMAR. BEST CHANCE OF PRECIP WILL BE OVER THE CENTRAL MTNS
AND THE PIKES PEAK REGION. SNOWFALL AMOUNTS OVER THE C MTNS WILL BE
2-4" WITH 1-3" OVER TELLER COUNTY AND POSSIBLY AN INCH OR TWO OVER N
EL PASO COUNTY. THERE COULD BE SOME COMMUTING ISSUES IN EL PASO
COUNTY LATE TOMORROW AFTERNOON. THIS WILL BE A QUICK MOVING EVENT
AND BY SUNRISE WED WE SHOULD BE SEEING CLEARING SKIES OVER MOST OF
THE REGION.
WED-WED NITE...
AREA WILL BE IN-BETWEEN SYSTEMS. SNOW SHOWERS WILL BE POSSIBLE OVER
THE CONTDVD WITH OTHER AREAS DRY. TEMPS WED WILL BE
SEASONABLE...U40S/L50S PLAINS.
THU INTO EARLY FRI...
FIRST PACIFIC SYSTEM MOVES ACROSS REGION. SKIES WILL CLOUD UP DURING
THE DAY THU WITH PRECIP INCREASING OVER THE MTNS DURING THE DAY.
SNOW WILL PICK UP IN INTENSITY LATE THU OVER THE CONTDVD AND
COULD BE LOCALLY HEAVY AT TIMES THU NITE BEFORE DECREASING EARLY
FRIDAY. SOME PRECIP WILL BE POSSIBLE OVER THE PLAINS...WITH THE
BEST CHANCE OVER EL PASO AND THE FAR EASTERN PLAINS...ESPECIALLY
KIOWA COUNTY. TEMPS COULD BE TRICKY THURSDAY AS A BOUNDARY WILL
LIKELY LIE ACROSS THE PLAINS EXTENDING FROM ROUGHLY KIM TO
PUEBLO...AREAS E OF THIS LINE COULD SEE A CLOUDY COOL DAY WHILE
AREAS WEST OF THIS LINE MAY BE QUITE WARM...WINDY AND DRY...WITH FIRE
WX CONCERNS POSSIBLE ESPECIALLY DOWN ON THE RATON MESA.
LATE FRIDAY INTO EARLY SUNDAY...
A MORE SIGNIFICANT PACIFIC SYSTEM WILL MOVE ACROSS THE REGION. THIS
SYSTEM HAS THE POTENTIAL TO BRING HEAVY SNOWS TO THE CONTDVD
REGION...AND LATEST MODEL RUNS ARE STARTING TO SHOW MORE SIGNIF
QPF. HPC SHOWING 1-3" LIQUID OVER THE MTNS DURING THIS TIME. A
BETTER CHANCE OF PRECIP WILL OCCUR ON THE PLAINS SATURDAY/SAT NITE
AS MUCH COLDER AIR WILL BE MOVING INTO THE REGION AS THE PACIFIC
STORM MOVES ACROSS. THIS COMBO OF COLDER UPSLOPE AND FORCING ALOFT
SHOULD ALLOW FOR SOME SNOW ON THE PLAINS. BEST CHANCE WILL BE
NORTH OF HIWAY 50. I DO ANTICIPATE TRAVEL INTO THE MTNS THIS
WEEKEND WILL BE A BIT TEDIOUS...BUT THERE IS NOT MUCH WIND WITH
THIS SYSTEM SO BLOWING SNOW WILL BE LESS OF A CONCERN.
IT SHOULD BE NOTED THAT THE GFS IS MORE INTENSE WITH THIS SYSTEM
THEN THE LESS AMPLIFIED EC MODEL...HOWEVER BOTH MODELS HAVE GOOD QPF
FOR THE MTNS.
LOOKING A BIT BEYOND...GFS SHOWS ANOTHER SHARP TROUGH COMING ACROSS
LATE MONDAY INTO EARLY TUESDAY WHILE EC SHOWS A MUCH WEAKER SYSTEM.
LONG RANGE DISCUSSIONS WERE LEANING MORE TOWARDS THE EC GUIDANCE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1023 PM MST MON FEB 24 2014
STRATUS EVIDENT IN FOG PRODUCTS WILL BE SPREADING WESTWARD INTO
THE KCOS AND KPUB TERMINALS BETWEEN 06Z AND 07Z. CIGS WILL LIKELY
DROP INTO THE IFR CATEGORY BY 08Z...AND COULD EVEN HIT LIFR
CATEGORY TOWARDS 12Z. FORECAST WILL BE CHALLENGING TOMORROW WITH
REGARD TO TIMING OF THE CLEARING OF THE STRATUS. MODELS HINT AT
CIGS BREAKING BY 16Z...BUT WITH SOUTHEAST FLOW CONTINUING OPTED TO
HOLD ON TO IFR CIGS UNTIL 18Z. TIMING WILL LIKELY NEED TO BE
FINE TUNED FURTHER AS HIGH RES MODELS CONTINUE TO RESOLVE THE
SITUATION. ANOTHER COLD FRONT WILL BLAST SOUTHWARD ACROSS THE KCOS
TERMINAL AROUND 22Z AND THROUGH KPUB BY 23Z. NORTH WIND GUSTS TO
40 TO 45 KTS WILL BE POSSIBLE WITH FRONTAL PASSAGE. CIGS SHOULD
QUICKLY LOWER INTO THE MVFR CATEGORY WITH -SN POSSIBLE AT KCOS BY
00Z. ONLY LIGHT ACCUMULATIONS EXPECTED OVERNIGHT AT KCOS AND KPUB
TERMINALS...WITH AMOUNTS RANGING FROM A DUSTING TO 1/2 INCH.
KALS WILL REMAIN VFR WITH WINDS GENERALLY UNDER 10 KTS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KT
SHORT TERM...MOZLEY
LONG TERM...HODANISH
AVIATION...KT
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1252 PM EST TUE FEB 25 2014
.SYNOPSIS...
UNSEASONABLY COLD WEATHER WILL CONTINUE RIGHT INTO THIS WEEKEND.
THERE WILL BE A FEW OPPORTUNITIES FOR SOME SNOW SHOWERS...BUT NO
MAJOR STORMS ARE EXPECTED THIS WEEK AND DRY WEATHER WILL DOMINATE.
A MORE SIGNIFICANT STORM MAY AFFECT OUR REGION BY THE LATE PORTION
OF THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1250 PM UPDATE...
CURRENT FORECAST ON TRACK. CONTINUED RISK FOR A FEW FLURRIES/SNOW
SHOWERS AS SHORTWAVE SWINGS THROUGH BUT DRY AIR IN THE LOW LEVELS
WILL BE A LIMITING FACTOR.
PREVIOUS DISCUSSION...
CLOUDS HAVE OVERSPREAD THE REGION THIS MORNING AND WILL PERSIST
THROUGH THE AFTERNOON GIVEN ABUNDANT 850 MB RH. MID LEVEL
SHORTWAVE AND SFC TROF MOVES THROUGH THIS AFTERNOON AND WILL BRING
A FEW SNOW SHOWERS/FLURRIES. HOWEVER...AREAL COVERAGE SHOULD BE
LIMITED AS LOWEST LEVELS ARE QUITE DRY WITH DEWPOINTS WELL DOWN
INTO THE SINGLE NUMBERS AND LOW LEVEL LAPSE RATES ARE NOT QUITE AS
ROBUST AS YESTERDAY. HRRR SHOWING JUST A FEW LIGHT SNOW SHOWERS
THIS AFTERNOON AND WILL SCALE POPS BACK TO ISOLD. MAX TEMPS WILL
BE MOSTLY IN THE 20S TO AROUND 30 IN THE COASTAL PLAIN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
TONIGHT...A MORE AMPLIFIED NORTHERN STREAM SHORTWAVE WILL BE
APPROACHING FROM THE GREAT LAKES. WEAK RIDGING AHEAD OF THIS
FEATURE WILL RESULT IN MAINLY DRY CONDITIONS.
WEDNESDAY...THE MODELS ARE IN GENERAL AGREEMENT THAT LOW
PRESSURE EMERGING OFF THE MID ATLANTIC COAST WILL PASS WELL
SOUTHEAST OF THE BENCHMARK. THERE IS STILL A NORTHERN STREAM
SHORTWAVE...WHICH ALSO PRODUCES A WEAK SURFACE WAVE. THIS FEATURE
WILL HAVE LIMITED MOISTURE.
THIS SETS UP A BRIEF WINDOW WEDNESDAY MORNING INTO WEDNESDAY
AFTERNOON WHERE CONDITIONS ARE FAVORABLE ENOUGH WITHIN THE PRIME
SNOW GROWTH REGION TO GET DECENT SNOW ACCUMULATION. STILL THINKING
MOST OF SOUTHERN NEW ENGLAND WILL BE AN INCH OR LESS...WITH A FEW
SPOTS TOWARD CAPE COD AND THE ISLANDS SEEING UP TO 2 INCHES OR SO.
MANY OF THE SNOW SHOWERS WILL BE EXITING THE COAST BY MID TO LATE
AFTERNOON AS DRIER MID LEVEL AIR RUSHES INTO THE REGION.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
*/ HIGHLIGHTS...
- UNSEASONABLY COLD TEMPERATURES PREVAIL THROUGHOUT THE FORECAST
- LIGHT SNOW FOR THURSDAY UNDER BLUSTERY WINDS
- WIND CHILL ADVISORIES MAY BE NEEDED FOR FRIDAY MORNING
- ANOTHER SHOT OF LIGHT SNOW SATURDAY
- A MORE SIGNIFICANT STORM APPEARING LIKELY SUNDAY INTO MONDAY
*/ OVERVIEW AND MODEL PREFERENCE...
CONSIDERING THE PROXIMITY AND EVOLUTION OF THE POLAR LOW COMBINED
WITH WESTERN CONUS RIDGING...A PROGRESSIVE FLOW PATTERN IS FAVORED.
SOME UNCERTAINTY AS TO THE DOWNSTREAM RIDGE STRENGTH ASSOCIATED WITH
THE NORTH-CENTRAL ATLANTIC HIGH...YET ENSEMBLE MEMBERS IN GOOD
AGREEMENT OF A SLIGHTLY +NAO. ANTICIPATING AN ACTIVE WEATHER PATTERN
WITH TROUGHING PREFERRED OVER THE NE CONUS. GREATEST UNCERTAINTY
LIES IN INDIVIDUAL MORPHOLOGY OF DISTURBANCES AND SUBSEQUENT SURFACE
OUTCOMES. THOUGH A MODEL-WEIGHTED CONSENSUS BLEND APPROACH HAS BEEN
CONDUCTED WITH THIS FORECAST...WILL OUTLINE OVERALL CONFIDENCE IN
THE DISCUSSION BELOW.
*/ DAY-TO-DAY DETAILS...
WEDNESDAY NIGHT INTO THURSDAY NIGHT...
POLAR WAVE INVOKES A CLIPPER LOW ACROSS THE NORTHERN GREAT LAKES
INTO NORTHERN NEW ENGLAND. ATTENDANT ARCTIC FRONT IS THE FOCUS FOR
LIGHT SNOW ACTIVITY. CONSIDERING THE DISTURBANCE IS CUT-OFF FROM SUB-
TROPICAL MOISTURE AND IS MORE CONTINENTAL POLAR WITH REGARDS TO
AIRMASS...MAIN CONCERN IS UPON BLUSTERY WINDS AND ARCTIC AIR.
BOUNDARY LAYER MIXING POTENTIALLY ALL THE WAY TO H7 AHEAD OF THE
FRONT THURSDAY AND IMMEDIATELY IN WAKE OF THE FRONT BY THURSDAY
EVENING WILL ALLOW FOR THE MIX-DOWN OF 30 TO 40 MPH GUSTS AT THE
SURFACE /INITIALLY SOUTHWESTERLY TURNING WESTERLY BEHIND THE FRONT/.
COMBINING THIS ALONG WITH UNSEASONABLY COLD TEMPERATURES /H85 AROUND
-20C BY FRIDAY MORNING/ AND THERE IS MODERATE CONFIDENCE TOWARDS THE
ISSUANCE OF WIND CHILL ADVISORIES OVER THE NORTH AND WEST INTERIOR
HIGH TERRAIN /ESPECIALLY FOR THURSDAY NIGHT INTO FRIDAY MORNING/.
LOW CONFIDENCE TOWARDS THE NEED FOR WIND ADVISORIES...FEEL WIND
GUSTS WILL REMAIN BELOW THRESHOLDS. WINDS DIMINISH TOWARDS FRIDAY
MORNING.
LIKELY GALES OVER THE WATERS WITH THE NEED FOR FREEZING SPRAY
ADVISORIES WITH COLD OCEAN TEMPERATURES. HIGH CONFIDENCE. LOWS IN
THE SINGLE DIGITS WITH HIGHS IN THE LOW- TO MID-20S.
FRIDAY INTO FRIDAY NIGHT...
ARCTIC HIGH PRESSURE BUILDS OVER THE REGION WITH UNSEASONABLY COLD
AIR. WITH H85 TEMPERATURES AROUND -20C DURING THE DAY...EXPECTING
HIGHS AROUND THE UPPER-TEENS TO LOW 20S. POSSIBLE WIND CHILL
ADVISORIES FOR THE MORNING SHOULD DROP OFF AS SURFACE TEMPERATURES MODERATE
AND WINDS BECOME LIGHT AND VARIABLE.
WILL KEEP THE FORECAST PERIOD DRY. INCREASING CLOUDS LATE AHEAD OF
THE WEEKEND DISTURBANCE IN ADDITION TO SOUTHWEST FLOW ALOFT AND
MODERATING TEMPERATURE TREND WHICH WILL ALLOW FOR SLIGHTLY WARMER
OVERNIGHT LOWS.
SATURDAY INTO SATURDAY NIGHT...
WEAK PACIFIC WAVE DISTURBANCE ABLE TO TAP INTO GULF MOISTURE IS
SEEMINGLY DEAMPLIFIED UNDER THE WEIGHT OF A REINFORCING ARCTIC FRONT
AND ACCOMPANYING HIGH PRESSURE. NOT EXPECTING MUCH THREAT WITH THE
WEAK NATURE OF THE SYSTEM...SOME LIGHT SNOW POSSIBLE WITH THE
POTENTIAL OF OCEAN-EFFECT SNOWS IN WAKE OF THE ARCTIC FRONT...
OTHERWISE WILL SEE THE CONTINUANCE OF UNSEASONABLY COLD TEMPS.
SUNDAY AND BEYOND...
CONSIDERING ENSEMBLE MEANS...HAVE HIGH CONFIDENCE OF A LOW FROM THE
GULF COAST LIFTING NORTHWARD THROUGH THE OHIO RIVER VALLEY TOWARDS
THE SOUTH-COAST OF NEW ENGLAND. BUT VARIANCE AND SPREAD AMONG MODEL
SOLUTIONS IS STILL TOO HIGH TOWARDS KNOWING EXACT OUTCOMES. EVEN THE
DETERMINISTIC ECMWF HAS RUN-TO-RUN WOBBLES IN THE LOW TRACK AND
POSITION THAT MAKE FOR VARYING FORECASTS. WILL AWAIT BETTER MODEL
CONSENSUS BEFORE GOING ANY FURTHER ON THE DETAILS.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH WEDNESDAY NIGHT/...
THROUGH TONIGHT...HIGH CONFIDENCE. VFR. CIGS 040-080 WITH GUSTY
W/NW WINDS UP TO 25 KT THIS AFTERNOON. LOW PROB FOR A FEW FLURRIES
AND BRIEF MVFR VSBYS. CLEARING SKIES AND DIMINISHING WIND THIS
EVENING. MID LEVEL CLOUDS RETURN LATE TONIGHT.
WEDNESDAY...HIGH CONFIDENCE. MAINLY VFR...BUT A PERIOD OF MVFR
POSSIBLE AS SNOW SHOWERS MOVE THROUGH THE REGION DURING MORNING
AND EARLY AFTERNOON. LOW PROB OF BRIEF IFR IN ANY HEAVIER
SQUALLS. PARTIAL CLEARING AFT 18Z FROM WEST TO EAST. WEST WIND
GUSTS 20-25 KT DEVELOPING IN THE AFTERNOON.
WEDNESDAY NIGHT...HIGH CONFIDENCE. VFR.
KBOS TERMINAL...LOW CONFIDENCE IN ANY FLURRIES THIS AFTERNOON.
HIGHER CONFIDENCE FOR A PERIOD OF SNOW SHOWERS WEDNESDAY.
KBDL TERMINAL...LOW CONFIDENCE IN ANY FLURRIES THIS AFTERNOON.
HIGHER CONFIDENCE FOR A PERIOD OF SNOW SHOWERS WEDNESDAY.
OUTLOOK...THURSDAY THROUGH SATURDAY NIGHT...
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...MODERATE CONFIDENCE.
MVFR-IFR WITH -SN. SW WINDS GUSTING UP TO AROUND 35 KTS DURING THE
DAY THURSDAY...BACKING WESTERLY BY EVENING AND DIMINISHING TOWARDS
MORNING.
FRIDAY INTO FRIDAY NIGHT...MODERATE CONFIDENCE.
VFR. LIGHT AND VARIABLE WINDS. INCREASING MID- TO HIGH-CLOUDS LATE.
SATURDAY INTO SATURDAY NIGHT...MODERATE CONFIDENCE.
MVFR-IFR WITH -SN. BREEZY SOUTHWEST WINDS BACKING W/NW TOWARDS
EVENING.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
THROUGH WEDNESDAY...HIGH CONFIDENCE.
GUSTY WEST TO NORTHWEST WINDS CONTINUES ACROSS THE COASTAL WATERS.
SMALL CRAFT ADVISORIES WILL CONTINUE. PRESSURE GRADIENT IS A
LITTLE WEAKER TODAY...SO WILL DROP THE ADVISORIES FOR BOSTON
HARBOR AND NARRAGANSETT BAY. A BIT OF A LULL EXPECTED THIS
MORNING ACROSS THE OTHER NEAR SHORE WATERS...BUT NOT ENOUGH OF ONE
TO DROP THE ADVISORY COMPLETELY. WOULD JUST HAVE TO REISSUE ONE
LATER THIS MORNING AND AFTERNOON AS WINDS PICK UP AGAIN.
WINDS WILL EVENTUALLY DIMINISH BELOW 25 KT TONIGHT...BEFORE
INCREASING AGAIN WEDNESDAY. ROUGH SEAS WILL BE SLOWER TO SUBSIDE
TONIGHT...ESPECIALLY ACROSS THE OUTER COASTAL WATERS. INCREASING
WINDS SHOULD RESULT IN BUILDING SEAS FOR WEDNESDAY...ESPECIALLY
TOWARDS THE OUTER WATERS. AREAS OF FREEZING SPRAY EXPECTED.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY NIGHT...
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...HIGH CONFIDENCE.
SOUTHWEST GALES AHEAD OF A FRONT WITH WIND GUSTS UP TO 40 KTS...
CONTINUING WHILE BACKING WESTERLY WITH FRONTAL PASSAGE...GRADUALLY
DIMINISHING TOWARDS FRIDAY MORNING. COMBINED WITH SEAS AND COLD
OCEAN TEMPERATURES AND THERE IS THE LIKELY NEED FOR FREEZING SPRAY
ADVISORIES AS MODERATE FREEZING SPRAY IS ANTICIPATED. LIGHT SNOW
ALSO POSSIBLE WHICH MAY MAKE FOR VISIBILITY RESTRICTIONS ON THE
WATERS.
FRIDAY INTO FRIDAY NIGHT...MODERATE CONFIDENCE.
HIGH PRESSURE BUILDS OVER THE WATERS THROUGH THE DAY. BOTH THE
THREAT OF FREEZING SPRAY AND GALE-FORCE WINDS DROP TOWARDS MIDDAY.
SEAS ALLOWED TO DIMINISH. SMALL-CRAFT ADVISORIES LIKELY.
SATURDAY INTO SATURDAY NIGHT...MODERATE CONFIDENCE.
BREEZY SOUTHWEST FLOW TURNING W/NW WITH AN ARCTIC FRONTAL PASSAGE BY
EVENING. WINDS ARE ANTICIPATED TO REMAIN BELOW 25 KTS. SEAS LIKELY
TO AMPLIFY WITH FETCH. LIGHT SNOW ALSO POSSIBLE WHICH COULD MAKE FOR
VISIBILITY RESTRICTIONS ON THE WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR
ANZ230>237-251.
SMALL CRAFT ADVISORY UNTIL 1 AM EST WEDNESDAY FOR ANZ250-
254>256.
&&
$$
SYNOPSIS...BELK/SIPPRELL
NEAR TERM...KJC
SHORT TERM...BELK
LONG TERM...SIPPRELL
AVIATION...KJC/SIPPRELL
MARINE...BELK/SIPPRELL
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1008 AM EST TUE FEB 25 2014
.SYNOPSIS...
UNSEASONABLY COLD WEATHER WILL CONTINUE RIGHT INTO THIS WEEKEND.
THERE WILL BE A FEW OPPORTUNITIES FOR SOME SNOW SHOWERS...BUT NO
MAJOR STORMS ARE EXPECTED THIS WEEK AND DRY WEATHER WILL DOMINATE.
A MORE SIGNIFICANT STORM MAY AFFECT OUR REGION BY THE LATE PORTION
OF THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...
CLOUDS HAVE OVERSPREAD THE REGION THIS MORNING AND WILL PERSIST
THROUGH THE AFTERNOON GIVEN ABUNDANT 850 MB RH. MID LEVEL
SHORTWAVE AND SFC TROF MOVES THROUGH THIS AFTERNOON AND WILL
BRING A FEW SNOW SHOWERS/FLURRIES. HOWEVER...AREAL COVERAGE SHOULD
BE LIMITED AS LOWEST LEVELS ARE QUITE DRY WITH DEWPOINTS WELL DOWN
INTO THE SINGLE NUMBERS AND LOW LEVEL LAPSE RATES ARE NOT QUITE AS
ROBUST AS YESTERDAY. HRRR SHOWING JUST A FEW LIGHT SNOW SHOWERS
THIS AFTERNOON AND WILL SCALE POPS BACK TO ISOLD. MAX TEMPS WILL
BE MOSTLY IN THE 20S TO AROUND 30 IN THE COASTAL PLAIN.
PREVIOUS DISCUSSION...
25/00Z GUIDANCE SUITE IS IN GOOD AGREEMENT...SO SEE NO MAJOR
REASON TO DEVIATE MUCH FROM THE CONSENSUS PATTERN FOR TODAY.
ANOTHER FAST MOVING SHORTWAVE WILL BE MOVING THROUGH OUR REGION
LATER TODAY. THERE SHOULD BE ENOUGH LOW LEVEL MOISTURE FOR A
REPEAT OF DIURNAL STRATOCUMULUS CLOUDS DEVELOPING. WE STILL CANNOT
COMPLETELY RULE OUT A FEW INTERIOR FLURRIES/SNOW SHOWERS. THESE
WOULD BE MAINLY CONFINED CLOSE TO THE BERKSHIRES...WHERE THERE IS
SOME ADDITIONAL MOISTURE BEING PROVIDED FROM LAKE ONTARIO. DRY
AIR IN THE LOWEST LEVELS WILL BE A LIMITING FACTOR DESPITE STEEP
LOW LEVEL LAPSE RATES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
TONIGHT...A MORE AMPLIFIED NORTHERN STREAM SHORTWAVE WILL BE
APPROACHING FROM THE GREAT LAKES. WEAK RIDGING AHEAD OF THIS
FEATURE WILL RESULT IN MAINLY DRY CONDITIONS.
WEDNESDAY...THE MODELS ARE IN GENERAL AGREEMENT THAT LOW
PRESSURE EMERGING OFF THE MID ATLANTIC COAST WILL PASS WELL
SOUTHEAST OF THE BENCHMARK. THERE IS STILL A NORTHERN STREAM
SHORTWAVE...WHICH ALSO PRODUCES A WEAK SURFACE WAVE. THIS FEATURE
WILL HAVE LIMITED MOISTURE.
THIS SETS UP A BRIEF WINDOW WEDNESDAY MORNING INTO WEDNESDAY
AFTERNOON WHERE CONDITIONS ARE FAVORABLE ENOUGH WITHIN THE PRIME
SNOW GROWTH REGION TO GET DECENT SNOW ACCUMULATION. STILL THINKING
MOST OF SOUTHERN NEW ENGLAND WILL BE AN INCH OR LESS...WITH A FEW
SPOTS TOWARD CAPE COD AND THE ISLANDS SEEING UP TO 2 INCHES OR SO.
MANY OF THE SNOW SHOWERS WILL BE EXITING THE COAST BY MID TO LATE
AFTERNOON AS DRIER MID LEVEL AIR RUSHES INTO THE REGION.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
*/ HIGHLIGHTS...
- UNSEASONABLY COLD TEMPERATURES PREVAIL THROUGHOUT THE FORECAST
- LIGHT SNOW FOR THURSDAY UNDER BLUSTERY WINDS
- WIND CHILL ADVISORIES MAY BE NEEDED FOR FRIDAY MORNING
- ANOTHER SHOT OF LIGHT SNOW SATURDAY
- A MORE SIGNIFICANT STORM APPEARING LIKELY SUNDAY INTO MONDAY
*/ OVERVIEW AND MODEL PREFERENCE...
CONSIDERING THE PROXIMITY AND EVOLUTION OF THE POLAR LOW COMBINED
WITH WESTERN CONUS RIDGING...A PROGRESSIVE FLOW PATTERN IS FAVORED.
SOME UNCERTAINTY AS TO THE DOWNSTREAM RIDGE STRENGTH ASSOCIATED WITH
THE NORTH-CENTRAL ATLANTIC HIGH...YET ENSEMBLE MEMBERS IN GOOD
AGREEMENT OF A SLIGHTLY +NAO. ANTICIPATING AN ACTIVE WEATHER PATTERN
WITH TROUGHING PREFERRED OVER THE NE CONUS. GREATEST UNCERTAINTY
LIES IN INDIVIDUAL MORPHOLOGY OF DISTURBANCES AND SUBSEQUENT SURFACE
OUTCOMES. THOUGH A MODEL-WEIGHTED CONSENSUS BLEND APPROACH HAS BEEN
CONDUCTED WITH THIS FORECAST...WILL OUTLINE OVERALL CONFIDENCE IN
THE DISCUSSION BELOW.
*/ DAY-TO-DAY DETAILS...
WEDNESDAY NIGHT INTO THURSDAY NIGHT...
POLAR WAVE INVOKES A CLIPPER LOW ACROSS THE NORTHERN GREAT LAKES
INTO NORTHERN NEW ENGLAND. ATTENDANT ARCTIC FRONT IS THE FOCUS FOR
LIGHT SNOW ACTIVITY. CONSIDERING THE DISTURBANCE IS CUT-OFF FROM SUB-
TROPICAL MOISTURE AND IS MORE CONTINENTAL POLAR WITH REGARDS TO
AIRMASS...MAIN CONCERN IS UPON BLUSTERY WINDS AND ARCTIC AIR.
BOUNDARY LAYER MIXING POTENTIALLY ALL THE WAY TO H7 AHEAD OF THE
FRONT THURSDAY AND IMMEDIATELY IN WAKE OF THE FRONT BY THURSDAY
EVENING WILL ALLOW FOR THE MIX-DOWN OF 30 TO 40 MPH GUSTS AT THE
SURFACE /INITIALLY SOUTHWESTERLY TURNING WESTERLY BEHIND THE FRONT/.
COMBINING THIS ALONG WITH UNSEASONABLY COLD TEMPERATURES /H85 AROUND
-20C BY FRIDAY MORNING/ AND THERE IS MODERATE CONFIDENCE TOWARDS THE
ISSUANCE OF WIND CHILL ADVISORIES OVER THE NORTH AND WEST INTERIOR
HIGH TERRAIN /ESPECIALLY FOR THURSDAY NIGHT INTO FRIDAY MORNING/.
LOW CONFIDENCE TOWARDS THE NEED FOR WIND ADVISORIES...FEEL WIND
GUSTS WILL REMAIN BELOW THRESHOLDS. WINDS DIMINISH TOWARDS FRIDAY
MORNING.
LIKELY GALES OVER THE WATERS WITH THE NEED FOR FREEZING SPRAY
ADVISORIES WITH COLD OCEAN TEMPERATURES. HIGH CONFIDENCE. LOWS IN
THE SINGLE DIGITS WITH HIGHS IN THE LOW- TO MID-20S.
FRIDAY INTO FRIDAY NIGHT...
ARCTIC HIGH PRESSURE BUILDS OVER THE REGION WITH UNSEASONABLY COLD
AIR. WITH H85 TEMPERATURES AROUND -20C DURING THE DAY...EXPECTING
HIGHS AROUND THE UPPER-TEENS TO LOW 20S. POSSIBLE WIND CHILL
ADVISORIES FOR THE MORNING SHOULD DROP OFF AS SURFACE TEMPERATURES MODERATE
AND WINDS BECOME LIGHT AND VARIABLE.
WILL KEEP THE FORECAST PERIOD DRY. INCREASING CLOUDS LATE AHEAD OF
THE WEEKEND DISTURBANCE IN ADDITION TO SOUTHWEST FLOW ALOFT AND
MODERATING TEMPERATURE TREND WHICH WILL ALLOW FOR SLIGHTLY WARMER
OVERNIGHT LOWS.
SATURDAY INTO SATURDAY NIGHT...
WEAK PACIFIC WAVE DISTURBANCE ABLE TO TAP INTO GULF MOISTURE IS
SEEMINGLY DEAMPLIFIED UNDER THE WEIGHT OF A REINFORCING ARCTIC FRONT
AND ACCOMPANYING HIGH PRESSURE. NOT EXPECTING MUCH THREAT WITH THE
WEAK NATURE OF THE SYSTEM...SOME LIGHT SNOW POSSIBLE WITH THE
POTENTIAL OF OCEAN-EFFECT SNOWS IN WAKE OF THE ARCTIC FRONT...
OTHERWISE WILL SEE THE CONTINUANCE OF UNSEASONABLY COLD TEMPS.
SUNDAY AND BEYOND...
CONSIDERING ENSEMBLE MEANS...HAVE HIGH CONFIDENCE OF A LOW FROM THE
GULF COAST LIFTING NORTHWARD THROUGH THE OHIO RIVER VALLEY TOWARDS
THE SOUTH-COAST OF NEW ENGLAND. BUT VARIANCE AND SPREAD AMONG MODEL
SOLUTIONS IS STILL TOO HIGH TOWARDS KNOWING EXACT OUTCOMES. EVEN THE
DETERMINISTIC ECMWF HAS RUN-TO-RUN WOBBLES IN THE LOW TRACK AND
POSITION THAT MAKE FOR VARYING FORECASTS. WILL AWAIT BETTER MODEL
CONSENSUS BEFORE GOING ANY FURTHER ON THE DETAILS.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH WEDNESDAY/...
12Z UPDATE...
VFR. SCT-BKN CIGS 040-080 WITH GUSTY W/NW WINDS UP TO 30 KTS THE
STRONGEST OF WHICH WILL BE MID-MORNING INTO THIS EVENING. THERE IS
THE POTENTIAL FOR -SN AND HAVE GONE AHEAD WITH A TEMPO MENTION
ALONG WITH MVFR VSBYS. MAY BE GOING A BIT ABOVE AND BEYOND WITH
THIS MENTION. COULD POTENTIALLY SEE -SN...BUT HARDLY ANY VSBY
IMPACT SHOULD -SN BE JUST FLURRIES.
MODERATE CONFIDENCE WEDNESDAY...MAINLY DUE TO TIMING. A PERIOD OF
MVFR CIGS/VSBYS IS LIKELY DURING THE DAY IN SOME SNOW SHOWERS.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. MODERATE CONFIDENCE WITH
TEMPO -SN.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF. MODERATE CONFIDENCE WITH
TEMPO -SN.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY NIGHT...
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...MODERATE CONFIDENCE.
MVFR-IFR WITH -SN. SW WINDS GUSTING UP TO AROUND 35 KTS DURING THE
DAY THURSDAY...BACKING WESTERLY BY EVENING AND DIMINISHING TOWARDS
MORNING.
FRIDAY INTO FRIDAY NIGHT...MODERATE CONFIDENCE.
VFR. LIGHT AND VARIABLE WINDS. INCREASING MID- TO HIGH-CLOUDS LATE.
SATURDAY INTO SATURDAY NIGHT...MODERATE CONFIDENCE.
MVFR-IFR WITH -SN. BREEZY SOUTHWEST WINDS BACKING W/NW TOWARDS
EVENING.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
THROUGH WEDNESDAY...HIGH CONFIDENCE.
GUSTY WEST TO NORTHWEST WINDS CONTINUES ACROSS THE COASTAL WATERS.
SMALL CRAFT ADVISORIES WILL CONTINUE. PRESSURE GRADIENT IS A
LITTLE WEAKER TODAY...SO WILL DROP THE ADVISORIES FOR BOSTON
HARBOR AND NARRAGANSETT BAY. A BIT OF A LULL EXPECTED THIS
MORNING ACROSS THE OTHER NEAR SHORE WATERS...BUT NOT ENOUGH OF ONE
TO DROP THE ADVISORY COMPLETELY. WOULD JUST HAVE TO REISSUE ONE
LATER THIS MORNING AND AFTERNOON AS WINDS PICK UP AGAIN.
WINDS WILL EVENTUALLY DIMINISH BELOW 25 KT TONIGHT...BEFORE
INCREASING AGAIN WEDNESDAY. ROUGH SEAS WILL BE SLOWER TO SUBSIDE
TONIGHT...ESPECIALLY ACROSS THE OUTER COASTAL WATERS. INCREASING
WINDS SHOULD RESULT IN BUILDING SEAS FOR WEDNESDAY...ESPECIALLY
TOWARDS THE OUTER WATERS. AREAS OF FREEZING SPRAY EXPECTED.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY NIGHT...
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...HIGH CONFIDENCE.
SOUTHWEST GALES AHEAD OF A FRONT WITH WIND GUSTS UP TO 40 KTS...
CONTINUING WHILE BACKING WESTERLY WITH FRONTAL PASSAGE...GRADUALLY
DIMINISHING TOWARDS FRIDAY MORNING. COMBINED WITH SEAS AND COLD
OCEAN TEMPERATURES AND THERE IS THE LIKELY NEED FOR FREEZING SPRAY
ADVISORIES AS MODERATE FREEZING SPRAY IS ANTICIPATED. LIGHT SNOW
ALSO POSSIBLE WHICH MAY MAKE FOR VISIBILITY RESTRICTIONS ON THE
WATERS.
FRIDAY INTO FRIDAY NIGHT...MODERATE CONFIDENCE.
HIGH PRESSURE BUILDS OVER THE WATERS THROUGH THE DAY. BOTH THE
THREAT OF FREEZING SPRAY AND GALE-FORCE WINDS DROP TOWARDS MIDDAY.
SEAS ALLOWED TO DIMINISH. SMALL-CRAFT ADVISORIES LIKELY.
SATURDAY INTO SATURDAY NIGHT...MODERATE CONFIDENCE.
BREEZY SOUTHWEST FLOW TURNING W/NW WITH AN ARCTIC FRONTAL PASSAGE BY
EVENING. WINDS ARE ANTICIPATED TO REMAIN BELOW 25 KTS. SEAS LIKELY
TO AMPLIFY WITH FETCH. LIGHT SNOW ALSO POSSIBLE WHICH COULD MAKE FOR
VISIBILITY RESTRICTIONS ON THE WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR
ANZ230>237-251.
SMALL CRAFT ADVISORY UNTIL 1 AM EST WEDNESDAY FOR ANZ250-
254>256.
&&
$$
SYNOPSIS...BELK/SIPPRELL
NEAR TERM...BELK/KJC
SHORT TERM...BELK
LONG TERM...SIPPRELL
AVIATION...BELK/SIPPRELL
MARINE...BELK/SIPPRELL
AREA FORECAST DISCUSSION
NWS ALBANY NY
1234 AM EST TUE FEB 25 2014
.SYNOPSIS...
AN ARCTIC AIR MASS WILL BE IN PLACE THIS WEEK WITH BELOW NORMAL
TEMPERATURES. A SERIES OF DISTURBANCES ASSOCIATED WITH AN UPPER
LEVEL LOW WILL PRODUCE SCATTERED SNOW SHOWERS AND FLURRIES INTO THE
MID WEEK. A CLIPPER LOW ON WEDNESDAY WILL PRODUCE MORE WIDESPREAD
SNOW SHOWERS...AS IT PASSES ACROSS THE SOUTHERN QUEBEC AND NORTHERN
NEW YORK BORDER...WITH A REINFORCING SHOT OF ARCTIC AIR.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF MIDNIGHT EST...LAKE EFFECT SNOW SHOWERS HAVE BEEN SLOWLY
ORGANIZING SOMEWHAT BETTER OVER THE PAST FEW HOURS OVER PORTIONS
OF OSWEGO/ONEIDA COUNTIES...BUT STILL ARE MAINLY FRAGMENTED BANDS
FARTHER EAST ACROSS THE MOHAWK VALLEY INTO THE GREATER CAPITAL DISTRICT.
TRENDS IN THE HRRR AND HIRES WRF INDICATE THESE FRAGMENTED BANDS
WILL DRIFT SOUTH INTO SOUTHERN HERKIMER COUNTY...WHERE A LAKE
EFFECT SNOW ADVISORY REMAINS IN EFFECT. HOWEVER...THE LATEST MODEL
REFLECTIVITY TRENDS SHOW BANDS WEAKENING CONSIDERABLY AFTER 1 AM.
WILL LEAVE UP ADVISORY FOR NOW...BUT WILL MONITOR TRENDS FOR
POSSIBLE CANCELLATION BEFORE 6 AM.
INVERSION HEIGHTS ARE MARGINAL UPSTREAM AT KSYR/KRME/KUCA AT 6-7
KFT AGL WITH A 280-290 DEG LOW-LEVEL TRAJ. THE INSTABILITY CLASS
IS CONDITIONAL TO MODERATE WITH NARROW FRAGMENTED LAKE BANDS
EXTENDING DOWNSTREAM INTO THE WESTERN MOHAWK VALLEY. WILL
CONTINUE TO MENTION SLIGHT TO LOW CHC POPS MAINLY WEST OF THE
HUDSON RIVER VALLEY...EXCEPT HIGH CHANCE TO LIKELY POPS FOR THE
WESTERN MOHAWK VALLEY AND A PORTION OF THE SOUTHWEST ADIRONDACKS
WHERE LAKE EFFECT ACTIVITY WILL BE MORE PRONOUNCED.
H850 TEMPS WILL BE IN THE -17C TO -20C RANGE WITH THE COLD
ADVECTION IN THE WAKE OF THE SFC TROUGH. EXPECT LOWS TO BE IN THE
UPPER SINGLE DIGITS AND TEENS FROM THE CAPITAL DISTRICT SOUTH AND
EAST...WITH SINGLE DIGITS TO A FEW BELOW ZERO READINGS /SRN DACKS/ OVER
THE NRN TIER. BRISK W/NW WINDS WILL GENERATE WIND CHILLS 10 TO 15
BELOW ZERO OVER THE SRN DACKS...AND GENERALLY 5 BELOW TO 5 ABOVE
IN MOST OTHER LOCATIONS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
TUESDAY...ANY ORGANIZED LAKE EFFECT ACTIVITY DIMINISHES DUE TO THE
LOWERING INVERSION. HOWEVER...LAKE MOISTURE WILL STILL BE
UTILIZED...AS A WEAK MID LEVEL DISTURBANCE MAY FOCUS ISOLATED TO
SCATTERED SNOW SHOWERS AGAIN DURING DURING THE MORNING INTO THE
AFTERNOON...WITH THE BETTER CHANCE OF SNOWFALL IN THE AFTERNOON
ALONG THE WRN SPINE OF THE WRN DACKS...SRN GREENS...NRN-CNTRL
TACONICS AND BERKSHIRES. THE WESTERLY UPSLOPE SNOW SHOWERS AND
FLURRIES MAY PRODUCE LIGHT SNOW AMOUNTS OF A COATING TO AN INCH OR
TWO. H850 TEMPS WILL BE RUNNING 1 TO 2 STANDARD DEVIATIONS BELOW
NORMAL ACCORDING TO THE LATEST GEFS. TEMPS WILL STILL RUN ABOUT 10
DEGREES OR SO BELOW NORMAL. OUR FORECAST FAVORS THE COLD NAM MOS
MAX TEMPS WITH TEENS OVER THE SRN DACKS. LOWER TO M20S OVER THE
REST OF THE FCST AREA...EXCEPT U20S OVER THE MID HUDSON
VALLEY...SRN TACONICS...AND NW CT.
TUE NIGHT...A CLIPPER LOW APPROACHES FROM THE NRN GREAT LAKES
REGION...AND SE ONTARIO. THIS CLIPPER WILL TAP SOME LAKE EFFECT
MOISTURE...AS THE FLOW BACKS TO SOUTHWEST. THERE IS SOME SYNOPTIC
LIFT WITH THIS SYSTEM. OROGRAPHIC AND LOW-LEVEL CONVERGENCE MAY
PROMOTE A PERIOD OF LIGHT SNOW ESPECIALLY NORTH AND WEST OF THE
CAPITAL REGION. A BURST OF LAKE EFFECT OR LAKE ENHANCED SNOWFALL
MAY OCCUR OVER THE WRN DACKS/WRN MOHAWK VALLEY AROUND MIDNIGHT AND
THEREAFTER. 1-4 INCHES OF SNOWFALL MAY BE POSSIBLE...ESPECIALLY
OVER THE WRN DACKS BY WED MORNING. WITH THE WEAK THERMAL
ADVECTION...SLIGHT OR LOW CHANCES OF SNOW SHOWERS SPREAD EASTWARD
ACROSS THE FCST AREA AFTER MIDNIGHT. LOWS WILL RANGE FROM THE
SINGLE DIGITS OVER THE NW PORTION OF THE FCST AREA TO TEENS FROM
THE MOHAWK VALLEY/CAPITAL REGION SOUTH AND EAST.
WED-WED NIGHT...THE CLIPPER MOVES N/NE OF NRN NY OVER SRN QUEBEC
BY NOON. ANOTHER LOW PRESSURE SYSTEM FORMS WELL OFF THE MID
ATLANTIC COAST. A PERIOD OF SNOW SHOWERS OR LIGHT SNOW WILL IMPACT
THE REGION DURING THE MORNING INTO THE EARLY PM AHEAD OF THE
ARCTIC FRONT. CHC POPS WERE USED FOR THE ENTIRE AREA. SNOW ACCUMS
OF A COATING TO AN INCH WILL BE POSSIBLE. ARCTIC AIR POURS BACK
INTO THE REGION WITH H850 TEMPS FALLING TO -19C TO -23C OVER THE
FCST AREA...AND THE GEFS INDICATE THESE VALUES WILL BE 2 TO 3
STANDARD DEVIATIONS BELOW NORMAL. THE STRONG COLD ADVECTION SWEEPS
THROUGH BEFORE NIGHTFALL. AFTER HIGHS IN THE TEENS AND 20S WITH
BLUSTERY CONDITIONS...LOWS WILL BE ZERO TO 5 BELOW OVER THE SRN
DACKS AND PARTS OF THE LAKE GEORGE REGION....AND SINGLE DIGITS
ELSEWHERE. UPSLOPE AND LAKE EFFECT SNOW SHOWERS WILL CONTINUE IN
THE AFTERNOON...AND THEN TAPER SNOW SHOWERS NORTH AND WEST OF THE
TRI CITIES WITH ANOTHER DISTURBANCE APPROACHING FROM THE UPPER
GREAT LAKES REGION. WIND CHILLS VALUES MAY NOT HIT ADVISORY LEVELS
WED NIGHT DUE TO A WEAKENING WIND FIELD...BUT MAY HIT ADVISORY
LEVELS OVER SOME OF THE MTN ZONES THU NIGHT/FRI MORNING.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
A SERIES OF EMBEDDED SHORTWAVES WILL MOVE ABOUT THE BASE OF A LARGE
UPPER LEVEL TROUGH THAT WILL PROVIDE CHANCES OF SOME PRECIPITATION
THROUGHOUT THE EXTENDED PERIOD. THE UPPER LEVEL FLOW PATTERN WILL
BEGIN TO SLOWLY TRANSITION INTO A ZONAL PATTERN WITH COLD AIR STILL
IN PLACE AS WE GO THE THE END OF THE EXTENDED PERIOD.
THURSDAY INTO FRIDAY...COLD NORTHWESTERLY FLOW WITH BELOW AVERAGE
TEMPERATURES WITH T850 BETWEEN -20C TO -24C AND T925 TEMPS BETWEEN
-16C AND -20C WILL BE LOCKED INTO THE REGION. A NEGATIVE TILTED
SHORTWAVE TROUGH WITHIN THE UPPER LEVEL FLOW WITH THE AXIS OVER THE
NY/CANADA BORDER WILL PROVIDE THE CHANCE OF SNOW SHOWERS ESPECIALLY
AREAS NORTH AND WEST OF THE IMMEDIATE CAPITAL REGION NEAR THE UPPER
LEVEL TROUGH AS WE GO THURSDAY NIGHT INTO FRIDAY MORNING. A STEEP
GRADIENT IN ISOBARS WILL ALSO PRODUCE GUSTY NORTHWEST WINDS
WITH GUSTS NEAR 30 MPH POSSIBLE ESPECIALLY IN THE HIGHEST TERRAIN.
TEMPERATURES ON THURSDAY WILL RANGE FROM THE LOWER 20S TO UPPER 20S
WHICH WILL FALL TO LOWER TEENS IN THE HIGH TERRAIN TO NEAR 20 IN
VALLEY LOCATIONS ON FRIDAY. LOW TEMPERATURES ON THURSDAY WILL BE
VERY COLD WITH VALUES RANGING FROM 10 BELOW TO NEAR ZERO IN THE HIGH
TERRAIN TO AROUND ZERO TO 5 ABOVE FOR THE VALLEY AREAS.
FRIDAY NIGHT THROUGH MONDAY...COLD AIR FROM CANADA WITH
NORTHWESTERLY WINDS WILL CONTINUE WITH SERIES OF UPPER LEVEL TROUGHS
CONTINUING TO MOVE WEST TO EAST ACROSS OUR AREA WITH AREAS OF WEAK
HIGH PRESSURE IN BETWEEN THE PASSING DISTURBANCES AS THE UPPER LEVEL
WAVE OSCILLATES AROUND THE LARGE UPPER LEVEL LOW IN NORTHERN QUEBEC.
THE NEXT CHANCE OF SNOW SHOWERS ACCORDING TO THE LATEST 12Z MODELS
AND NUMERICAL GUIDANCE WILL BE DURING THE DAY ON SATURDAY AS ANOTHER
WAVE OF LOW PRESSURE MOVES RIGHT OVER OUR REGION ACCORDING TO THE
LATEST TRENDS. CHANCE OF SNOW SHOWERS WILL BE IN THE FORECAST AT
THIS TIME AS THE TRACK AND INTENSITY AGREEMENT BETWEEN THE MODELS
SHOW LOW CONFIDENCE AT THIS TIME. A SURFACE HIGH PRESSURE WILL WORK
INTO THE AREA ON SUNDAY GIVING TRANQUIL WEATHER CONDITIONS. AS WE GO
INTO MONDAY...THE MODELS DO DIFFER IN OUR NEXT WEATHER SYSTEM WITH
ITS TRACK AND INTENSITY. THIS WILL HAVE TO BE MONITORED WITH FUTURE
UPDATES TO THE FORECAST. HIGH TEMPERATURES FROM SATURDAY INTO MONDAY
WILL REMAIN BELOW AVERAGE WITH TEMPERATURES RANGING FROM THE MID
TEENS TO MID 20S. LOW TEMPERATURES WILL ALSO BE VERY COLD FOR THIS
TIME OF YEAR WITH TEMPERATURE 10 BELOW ZERO TO NEAR ZERO FOR THE
LAKE GEORGE SARATOGA REGION POINTS NORTH AND WEST AND ALSO IN THE
HIGH TERRAIN OF NEW ENGLAND AND WITH LOW TEMPERATURES OF 0 TO 5 IN
THE IMMEDIATE CAPITAL REGION AND VALLEY LOCATIONS.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AN UPPER LEVEL DISTURBANCE WILL PASS SOUTH OF THE REGION LATER THIS
MORNING INTO EARLY AFTERNOON.
MAINLY VFR CONDITIONS WITH CIGS AROUND 3500-5000 FEET ARE
EXPECTED AT THE TERMINALS THROUGH THE 24 HOUR PERIOD ENDING 06Z
WEDNESDAY. HOWEVER...THE COMBINATION OF SOME LAKE EFFECT
MOISTURE...AND ALSO THE AFOREMENTIONED UPPER LEVEL IMPULSE PASSING
SOUTH OF THE REGION...SHOULD ALLOW FOR AT LEAST SOME
ISOLATED/SCATTERED SNOW SHOWERS TO OCCUR THROUGH MUCH OF TUESDAY.
IN THE NEAR TERM...THE BAND OF SNOW SHOWERS CURRENTLY ACROSS THE
MOHAWK VALLEY REGION IS EXPECTED TO CONTINUE SHIFTING SLOWLY
SOUTH...AND WEAKEN. HOWEVER...A FEW FILAMENTS OF SNOW SHOWERS MAY
STILL REACH KALB AND KPSF THROUGH 08Z/TUE. THIS COULD LEAD TO BRIEF
REDUCTIONS IN VSBY INTO THE MVFR/IFR RANGE.
THEN...AFTER DAYBREAK...SNOW SHOWERS SHOULD INCREASE IN AREAL
COVERAGE ONCE AGAIN...PEAKING LATER THIS MORNING INTO THE MID
AFTERNOON. AGAIN...OVERALL COVERAGE SHOULD BE SCATTERED...BUT SHOULD
ANY IMPACT THE TAF SITES...VSBYS COULD DROP INTO THE IFR RANGE. THE
SNOW SHOWERS SHOULD DECREASE IN AREAL COVERAGE AFTER 20Z/TUE AS THE
DISTURBANCE STARTS TO MOVE AWAY FROM THE REGION...AND LAKE EFFECT
ACTIVITY DECREASES.
WEST-NORTHWEST WINDS WILL DECREASE SLIGHTLY TO AROUND 8-12 KT
THROUGH DAYBREAK...ALTHOUGH MAY STILL OCCASIONALLY GUST UP TO 15-20
KT...ESP AT KALB AND KPSF. WIND SPEEDS WILL INCREASE AGAIN BY MID
MORNING TUESDAY TO 10-15 KT WITH SOME GUSTS OF AROUND 25
KT...STRONGEST AT KALB AND KPSF DUE TO FUNNELING EFFECT DOWN THE
MOHAWK RIVER VALLEY.
OUTLOOK...
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. WINDY. CHANCE OF SHSN.
WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: MODERATE OPERATIONAL IMPACT. BREEZY. CHANCE OF SHSN.
THURSDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
&&
.HYDROLOGY...
AN ARCTIC AIR MASS WILL REMAIN ACROSS THE HYDRO SERVICE AREA FOR
THE ENTIRE WEEK WHICH WILL ALLOW ICE TO REFORM...THICKEN...AND
STRENGTHEN ON AREA RIVERS AND LAKES THROUGH THE WEEK. LIGHT
PRECIPITATION IS EXPECTED DURING THE WEEK...AND ANY THAT DOES
OCCUR WILL BE IN THE FORM OF SNOW SHOWERS OR LIGHT SNOW. NO HYDRO
IMPACTS ARE EXPECTED ON THE MAIN STEM RIVERS THE NEXT 5 DAYS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST EARLY THIS MORNING
FOR NYZ038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/WASULA
NEAR TERM...11/JPV/WASULA
SHORT TERM...WASULA
LONG TERM...LFM
AVIATION...KL/JPV
HYDROLOGY...11/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1213 AM EST TUE FEB 25 2014
.SYNOPSIS...
AN ARCTIC AIR MASS WILL BE IN PLACE THIS WEEK WITH BELOW NORMAL
TEMPERATURES. A SERIES OF DISTURBANCES ASSOCIATED WITH AN UPPER
LEVEL LOW WILL PRODUCE SCATTERED SNOW SHOWERS AND FLURRIES INTO THE
MID WEEK. A CLIPPER LOW ON WEDNESDAY WILL PRODUCE MORE WIDESPREAD
SNOW SHOWERS...AS IT PASSES ACROSS THE SOUTHERN QUEBEC AND NORTHERN
NEW YORK BORDER...WITH A REINFORCING SHOT OF ARCTIC AIR.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF MIDNIGHT EST...LAKE EFFECT SNOW SHOWERS HAVE BEEN SLOWLY
ORGANIZING SOMEWHAT BETTER OVER THE PAST FEW HOURS OVER PORTIONS
OF OSWEGO/ONEIDA COUNTIES...BUT STILL ARE MAINLY FRAGMENTED BANDS
FARTHER EAST ACROSS THE MOHAWK VALLEY INTO THE GREATER CAPITAL DISTRICT.
TRENDS IN THE HRRR AND HIRES WRF INDICATE THESE FRAGMENTED BANDS
WILL DRIFT SOUTH INTO SOUTHERN HERKIMER COUNTY...WHERE A LAKE
EFFECT SNOW ADVISORY REMAINS IN EFFECT. HOWEVER...THE LATEST MODEL
REFLECTIVITY TRENDS SHOW BANDS WEAKENING CONSIDERABLY AFTER 1 AM.
WILL LEAVE UP ADVISORY FOR NOW...BUT WILL MONITOR TRENDS FOR
POSSIBLE CANCELLATION BEFORE 6 AM.
INVERSION HEIGHTS ARE MARGINAL UPSTREAM AT KSYR/KRME/KUCA AT 6-7
KFT AGL WITH A 280-290 DEG LOW-LEVEL TRAJ. THE INSTABILITY CLASS
IS CONDITIONAL TO MODERATE WITH NARROW FRAGMENTED LAKE BANDS
EXTENDING DOWNSTREAM INTO THE WESTERN MOHAWK VALLEY. WILL
CONTINUE TO MENTION SLIGHT TO LOW CHC POPS MAINLY WEST OF THE
HUDSON RIVER VALLEY...EXCEPT HIGH CHANCE TO LIKELY POPS FOR THE
WESTERN MOHAWK VALLEY AND A PORTION OF THE SOUTHWEST ADIRONDACKS
WHERE LAKE EFFECT ACTIVITY WILL BE MORE PRONOUNCED.
H850 TEMPS WILL BE IN THE -17C TO -20C RANGE WITH THE COLD
ADVECTION IN THE WAKE OF THE SFC TROUGH. EXPECT LOWS TO BE IN THE
UPPER SINGLE DIGITS AND TEENS FROM THE CAPITAL DISTRICT SOUTH AND
EAST...WITH SINGLE DIGITS TO A FEW BELOW ZERO READINGS /SRN DACKS/ OVER
THE NRN TIER. BRISK W/NW WINDS WILL GENERATE WIND CHILLS 10 TO 15
BELOW ZERO OVER THE SRN DACKS...AND GENERALLY 5 BELOW TO 5 ABOVE
IN MOST OTHER LOCATIONS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
TUESDAY...ANY ORGANIZED LAKE EFFECT ACTIVITY DIMINISHES DUE TO THE
LOWERING INVERSION. HOWEVER...LAKE MOISTURE WILL STILL BE
UTILIZED...AS A WEAK MID LEVEL DISTURBANCE MAY FOCUS ISOLATED TO
SCATTERED SNOW SHOWERS AGAIN DURING DURING THE MORNING INTO THE
AFTERNOON...WITH THE BETTER CHANCE OF SNOWFALL IN THE AFTERNOON
ALONG THE WRN SPINE OF THE WRN DACKS...SRN GREENS...NRN-CNTRL
TACONICS AND BERKSHIRES. THE WESTERLY UPSLOPE SNOW SHOWERS AND
FLURRIES MAY PRODUCE LIGHT SNOW AMOUNTS OF A COATING TO AN INCH OR
TWO. H850 TEMPS WILL BE RUNNING 1 TO 2 STANDARD DEVIATIONS BELOW
NORMAL ACCORDING TO THE LATEST GEFS. TEMPS WILL STILL RUN ABOUT 10
DEGREES OR SO BELOW NORMAL. OUR FORECAST FAVORS THE COLD NAM MOS
MAX TEMPS WITH TEENS OVER THE SRN DACKS. LOWER TO M20S OVER THE
REST OF THE FCST AREA...EXCEPT U20S OVER THE MID HUDSON
VALLEY...SRN TACONICS...AND NW CT.
TUE NIGHT...A CLIPPER LOW APPROACHES FROM THE NRN GREAT LAKES
REGION...AND SE ONTARIO. THIS CLIPPER WILL TAP SOME LAKE EFFECT
MOISTURE...AS THE FLOW BACKS TO SOUTHWEST. THERE IS SOME SYNOPTIC
LIFT WITH THIS SYSTEM. OROGRAPHIC AND LOW-LEVEL CONVERGENCE MAY
PROMOTE A PERIOD OF LIGHT SNOW ESPECIALLY NORTH AND WEST OF THE
CAPITAL REGION. A BURST OF LAKE EFFECT OR LAKE ENHANCED SNOWFALL
MAY OCCUR OVER THE WRN DACKS/WRN MOHAWK VALLEY AROUND MIDNIGHT AND
THEREAFTER. 1-4 INCHES OF SNOWFALL MAY BE POSSIBLE...ESPECIALLY
OVER THE WRN DACKS BY WED MORNING. WITH THE WEAK THERMAL
ADVECTION...SLIGHT OR LOW CHANCES OF SNOW SHOWERS SPREAD EASTWARD
ACROSS THE FCST AREA AFTER MIDNIGHT. LOWS WILL RANGE FROM THE
SINGLE DIGITS OVER THE NW PORTION OF THE FCST AREA TO TEENS FROM
THE MOHAWK VALLEY/CAPITAL REGION SOUTH AND EAST.
WED-WED NIGHT...THE CLIPPER MOVES N/NE OF NRN NY OVER SRN QUEBEC
BY NOON. ANOTHER LOW PRESSURE SYSTEM FORMS WELL OFF THE MID
ATLANTIC COAST. A PERIOD OF SNOW SHOWERS OR LIGHT SNOW WILL IMPACT
THE REGION DURING THE MORNING INTO THE EARLY PM AHEAD OF THE
ARCTIC FRONT. CHC POPS WERE USED FOR THE ENTIRE AREA. SNOW ACCUMS
OF A COATING TO AN INCH WILL BE POSSIBLE. ARCTIC AIR POURS BACK
INTO THE REGION WITH H850 TEMPS FALLING TO -19C TO -23C OVER THE
FCST AREA...AND THE GEFS INDICATE THESE VALUES WILL BE 2 TO 3
STANDARD DEVIATIONS BELOW NORMAL. THE STRONG COLD ADVECTION SWEEPS
THROUGH BEFORE NIGHTFALL. AFTER HIGHS IN THE TEENS AND 20S WITH
BLUSTERY CONDITIONS...LOWS WILL BE ZERO TO 5 BELOW OVER THE SRN
DACKS AND PARTS OF THE LAKE GEORGE REGION....AND SINGLE DIGITS
ELSEWHERE. UPSLOPE AND LAKE EFFECT SNOW SHOWERS WILL CONTINUE IN
THE AFTERNOON...AND THEN TAPER SNOW SHOWERS NORTH AND WEST OF THE
TRI CITIES WITH ANOTHER DISTURBANCE APPROACHING FROM THE UPPER
GREAT LAKES REGION. WIND CHILLS VALUES MAY NOT HIT ADVISORY LEVELS
WED NIGHT DUE TO A WEAKENING WIND FIELD...BUT MAY HIT ADVISORY
LEVELS OVER SOME OF THE MTN ZONES THU NIGHT/FRI MORNING.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
A SERIES OF EMBEDDED SHORTWAVES WILL MOVE ABOUT THE BASE OF A LARGE
UPPER LEVEL TROUGH THAT WILL PROVIDE CHANCES OF SOME PRECIPITATION
THROUGHOUT THE EXTENDED PERIOD. THE UPPER LEVEL FLOW PATTERN WILL
BEGIN TO SLOWLY TRANSITION INTO A ZONAL PATTERN WITH COLD AIR STILL
IN PLACE AS WE GO THE THE END OF THE EXTENDED PERIOD.
THURSDAY INTO FRIDAY...COLD NORTHWESTERLY FLOW WITH BELOW AVERAGE
TEMPERATURES WITH T850 BETWEEN -20C TO -24C AND T925 TEMPS BETWEEN
-16C AND -20C WILL BE LOCKED INTO THE REGION. A NEGATIVE TILTED
SHORTWAVE TROUGH WITHIN THE UPPER LEVEL FLOW WITH THE AXIS OVER THE
NY/CANADA BORDER WILL PROVIDE THE CHANCE OF SNOW SHOWERS ESPECIALLY
AREAS NORTH AND WEST OF THE IMMEDIATE CAPITAL REGION NEAR THE UPPER
LEVEL TROUGH AS WE GO THURSDAY NIGHT INTO FRIDAY MORNING. A STEEP
GRADIENT IN ISOBARS WILL ALSO PRODUCE GUSTY NORTHWEST WINDS
WITH GUSTS NEAR 30 MPH POSSIBLE ESPECIALLY IN THE HIGHEST TERRAIN.
TEMPERATURES ON THURSDAY WILL RANGE FROM THE LOWER 20S TO UPPER 20S
WHICH WILL FALL TO LOWER TEENS IN THE HIGH TERRAIN TO NEAR 20 IN
VALLEY LOCATIONS ON FRIDAY. LOW TEMPERATURES ON THURSDAY WILL BE
VERY COLD WITH VALUES RANGING FROM 10 BELOW TO NEAR ZERO IN THE HIGH
TERRAIN TO AROUND ZERO TO 5 ABOVE FOR THE VALLEY AREAS.
FRIDAY NIGHT THROUGH MONDAY...COLD AIR FROM CANADA WITH
NORTHWESTERLY WINDS WILL CONTINUE WITH SERIES OF UPPER LEVEL TROUGHS
CONTINUING TO MOVE WEST TO EAST ACROSS OUR AREA WITH AREAS OF WEAK
HIGH PRESSURE IN BETWEEN THE PASSING DISTURBANCES AS THE UPPER LEVEL
WAVE OSCILLATES AROUND THE LARGE UPPER LEVEL LOW IN NORTHERN QUEBEC.
THE NEXT CHANCE OF SNOW SHOWERS ACCORDING TO THE LATEST 12Z MODELS
AND NUMERICAL GUIDANCE WILL BE DURING THE DAY ON SATURDAY AS ANOTHER
WAVE OF LOW PRESSURE MOVES RIGHT OVER OUR REGION ACCORDING TO THE
LATEST TRENDS. CHANCE OF SNOW SHOWERS WILL BE IN THE FORECAST AT
THIS TIME AS THE TRACK AND INTENSITY AGREEMENT BETWEEN THE MODELS
SHOW LOW CONFIDENCE AT THIS TIME. A SURFACE HIGH PRESSURE WILL WORK
INTO THE AREA ON SUNDAY GIVING TRANQUIL WEATHER CONDITIONS. AS WE GO
INTO MONDAY...THE MODELS DO DIFFER IN OUR NEXT WEATHER SYSTEM WITH
ITS TRACK AND INTENSITY. THIS WILL HAVE TO BE MONITORED WITH FUTURE
UPDATES TO THE FORECAST. HIGH TEMPERATURES FROM SATURDAY INTO MONDAY
WILL REMAIN BELOW AVERAGE WITH TEMPERATURES RANGING FROM THE MID
TEENS TO MID 20S. LOW TEMPERATURES WILL ALSO BE VERY COLD FOR THIS
TIME OF YEAR WITH TEMPERATURE 10 BELOW ZERO TO NEAR ZERO FOR THE
LAKE GEORGE SARATOGA REGION POINTS NORTH AND WEST AND ALSO IN THE
HIGH TERRAIN OF NEW ENGLAND AND WITH LOW TEMPERATURES OF 0 TO 5 IN
THE IMMEDIATE CAPITAL REGION AND VALLEY LOCATIONS.
&&
.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
MAINLY VFR CONDITIONS WITH CIGS AROUND 3500-5000 FEET ARE
EXPECTED AT THE TERMINALS THROUGH THE 24 HOUR PERIOD ENDING 00Z
WEDNESDAY. THE ONLY EXCEPTION WILL BE A LOW PROBABILITY FOR A
PASSING SNOW SHOWER OR TWO. SNOW SHOWERS HAVE BEEN DIMINISHING IN
COVERAGE THIS EVENING WITH LOSS OF DAYTIME HEATING.
HOWEVER...THERE IS STILL A CHANCE FOR A FEW LAKE ENHANCED SNOW
SHOWERS TONIGHT INTO EARLY TUESDAY MORNING. WILL MENTION VCSH AT
THE ALB/KPSF/KGFL TERMINALS TO ACCOUNT FOR THIS CHANCE. ANY SNOW
SHOWER COULD BRIEFLY RESULT IN MVFR/IFR CONDITIONS...BUT
PROBABILITY OF OCCURRENCE IS TOO LOW TO MENTION EXPLICITLY IN
TAFS.
WEST-NORTHWEST WINDS WILL INITIALLY BE AROUND 10-15 KT WITH GUSTS
TO 25 KT ESPECIALLY AT KALB/KPSF...WITH WIND SPEEDS DECREASING TO
AROUND 5-10 KT AFTER MIDNIGHT. WIND SPEEDS WILL INCREASE AGAIN BY
MID MORNING TUESDAY TO AROUND 10-15 KT WITH SOME GUSTS NEAR 20 KT.
OUTLOOK...
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. WINDY. CHANCE OF SHSN.
WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: MODERATE OPERATIONAL IMPACT. BREEZY. CHANCE OF SHSN.
THURSDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
&&
.HYDROLOGY...
AN ARCTIC AIR MASS WILL REMAIN ACROSS THE HYDRO SERVICE AREA FOR
THE ENTIRE WEEK WHICH WILL ALLOW ICE TO REFORM...THICKEN...AND
STRENGTHEN ON AREA RIVERS AND LAKES THROUGH THE WEEK. LIGHT
PRECIPITATION IS EXPECTED DURING THE WEEK...AND ANY THAT DOES
OCCUR WILL BE IN THE FORM OF SNOW SHOWERS OR LIGHT SNOW. NO HYDRO
IMPACTS ARE EXPECTED ON THE MAIN STEM RIVERS THE NEXT 5 DAYS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST EARLY THIS MORNING
FOR NYZ038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/WASULA
NEAR TERM...11/JPV/WASULA
SHORT TERM...WASULA
LONG TERM...LFM
AVIATION...JPV
HYDROLOGY...11/WASULA
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1031 AM EST TUE FEB 25 2014
.UPDATE...FOG HAS LIFTED BUT AREAS OF LOW CLOUDS CONTINUE
ESPECIALLY OVER OUR SOUTHERN ZONES. THESE CLOUDS ARE ERODING FROM
THE EDGES AS SURFACE HEATING CONTINUES. MADE SOME TWEAKS TO THE
SKY COVER GRIDS.
WE CURRENTLY HAVE 20 PERCENT SHOWER CHANCES IN THE FORECAST FOR
THE AFTERNOON HOURS. LOOKING AT THE LATEST SUITE OF GLOBAL
MODELS...THE VAST MAJORITY OF SHOWERS WILL BE TO THE EAST OF OUR
FORECAST AREA...PERHAPS CLIPPING HIGHLANDS COUNTY. THE HRRR ON THE
OTHER HAND DEVELOPS SHOWERS ALONG THE CONVERGENT BOUNDARY
ASSOCIATED WITH THE DECAYED FRONT. THIS BOUNDARY IS MOVING
SOUTHEAST THROUGH HILLSBOROUGH COUNTY NOW...SO EVEN IF SHOWERS DO
DEVELOP...IT SHOULD STAY DRY TO THE NORTH. FOR THIS
UPDATE...REMOVED RAIN CHANCES FROM MANATEE COUNTY NORTHWARD ALONG
THE COAST BUT LEFT SLIGHT CHANCES IN FROM LEE AND CHARLOTTE
COUNTIES NORTHEAST ACROSS DESOTO AND HIGHLANDS.
THE GRIDDED FORECAST DATABASE HAS BEEN UPDATED. THE TEXT ZONE
FORECASTS WILL BE OUT SHORTLY.
&&
.AVIATION...
CONDITIONS CONTINUE TO IMPROVE FOR KTPA...KPIE...KLAL...AND KSRQ AND
GENERAL VFR CONDITIONS CAN BE ANTICIPATED FOR THE REST OF THE DAY
AND EVENING. IMPROVEMENT HAS BEEN SLOWER FURTHER SOUTH TOWARD KPGD
AND KRSW. EXPECT IFR/MVFR RESTRICTIONS FOR THESE TERMINALS TO LIFT
BY MIDDAY WITH VFR THEN PREVAILING THROUGH THE EVENING. AREAS OF
CIG/VIS RESTRICTIONS ARE EXPECTED TO REDEVELOP AFTER MIDNIGHT INTO
THE FIRST FEW DAYLIGHT HOURS OF WEDNESDAY.
&&
.MARINE...
SOME PATCHY SEA FOG MAY BE OCCURRING JUST OFFSHORE BUT DEW POINT
TEMPERATURES HAVE FALLEN BELOW THE SEA SURFACE TEMPERATURES.
CHANCES ARE THAT MUCH OF WHAT WE SEE ON SATELLITE IMAGERY IS
SITTING ABOVE THE SURFACE AS A LOW STRATUS LAYER. THE GENERAL
TREND HAS BEEN FOR DECREASING COVERAGE SO WILL NOT INCLUDE FOG IN
THE UPDATE.
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/MARINE...JILLSON
AVIATION...MROCZKA
AREA FORECAST DISCUSSION
NWS MIAMI FL
1245 AM EST TUE FEB 25 2014
.AVIATION...
VFR CONDITIONS SHOULD PERSIST THROUGH THE BULK OF THE TAF PERIOD
WITH LIGHT WINDS. ALTHOUGH FOG IS CERTAINLY NOT OUT OF QUESTION
FOR TMB AND APF BY DAYBREAK TODAY...THE LATEST IR SATELLITE
IMAGERY CONTINUES TO SHOW PLENTY OF UPPER-LEVEL CLOUDS STREAMING
WEST TO EAST OVER THE AREA THAT WILL REDUCE THESE CHANCES. LATER
TODAY...THE BEST SHRA/TSTM CHANCES WILL REMAIN ALONG THE EAST
COAST SITES THROUGH THE AFTERNOON AND EARLY EVENING HOURS.
&&
.PREV DISCUSSION... /ISSUED 858 PM EST MON FEB 24 2014/
UPDATE...
MAINLY TRANQUIL CONDITIONS PREVAIL ACROSS THE REGION THIS EVENING.
BY THE EARLY MORNING HOURS PATCHY FOG IS EXPECTED ACROSS THE
REGION AGAIN...MAINLY ACROSS THE INTERIOR REGIONS AND WEST.
NO SIGNIFICANT CHANGES WERE REQUIRED TO THE FORECAST.
60
PREV DISCUSSION... /ISSUED 628 PM EST MON FEB 24 2014/
AVIATION...
CONDITIONS SHOULD BE MOSTLY QUIET TONIGHT, WITH THE EXCEPTION OF A
STRAY, LIGHT SHOWER THAT COULD DEVELOP. OTHERWISE, VFR CONDITIONS
FOR THE EASTERN TAF SITES. THE EXCEPTION MAY BE KTMB, WHERE SOME
SOME FOG COULD DEVELOP. HOWEVER, THE IS TOO MUCH UNCERTAINTY TO
PUT A MENTION IN THE TAF AT THIS TIME. ALSO, KAPF MAY SEE SOME
FOG. THERE IS A BETTER CHANCE FOR NAPLES, THUS A MENTION OF LIGHT
FOG IN THE TAF FOR TONIGHT. TOMORROW WILL SEE A CHANCE OF SHOWERS
AND MAYBE A THUNDERSTORM FOR THE EASTERN HALF OF SOUTH FLORIDA.
FOR NOW, JUST A VCSH TO REFLECT THIS. WINDS WILL GO LIGHT AND
VARIABLE TONIGHT. THEY MAY BE DELAYED IN PICKING UP OUT OF THE
WEST TO SOUTHWEST TOMORROW BETWEEN 5 AND 10 KTS. KFLL MAYBE THE
EXCEPTION WHERE A WEAK SEA BREEZE MAY BRING THE WINDS TO A MORE
SOUTH SOUTH EASTERLY DIRECTION BY LATE MORNING OR EARLY AFTERNOON.
PREV DISCUSSION... /ISSUED 246 PM EST MON FEB 24 2014/
DISCUSSION...
A WEAK COLD FRONT CURRENTLY DRAPED ACROSS NORTHERN FLORIDA IS
EXPECTED TO SLOWLY PUSH TO THE SOUTH THROUGH THE AFTERNOON AND
EVENING. AS IT DOES...A FEW SHOWERS AND POSSIBLY AN ISOLATED
THUNDERSTORM OR TWO MAY DEVELOP ACROSS MAINLY THE EAST COASTAL AREAS
ENHANCED BY A WEAK SEA BREEZE THAT MAY DEVELOP. LATEST HRRR WINDS
DEPICT A WEAK SEA BREEZE ALONG MAINLY THE BROWARD AND PALM BEACH
COUNTY COASTS.
MODELS DEPICT THE COLD FRONT AND ACCOMPANYING DEEPER MOISTURE FIELD
TO BECOME NEARLY STATIONARY ACROSS SOUTH FLORIDA THROUGH TUESDAY
WITH RAIN CHANCES REMAINING ALONG WITH LIGHT AND VARIABLE WINDS.
KEPT SLIGHT CHANCES FOR THUNDERSTORMS TUESDAY AFTERNOON ALONG THE
NORTHERN INTERIOR AND EAST COAST AS WELL WITH THE LINGERING BOUNDARY
IN THE AREA. BY TUESDAY NIGHT INTO EARLY WEDNESDAY...THE FRONT IS
EXPECTED TO BASICALLY WASH OUT IN PLACE. FLOW WILL THEN QUICKLY
BECOME SOUTHWEST AND INCREASE LATE WEDNESDAY OUT AHEAD OF ANOTHER
COLD FRONT POSITIONED ACROSS THE NORTHERN GULF OF MEXICO. THIS FRONT
LOOKS TO BE A BIT STRONGER THAN THE LAST ONE AND SHOULD PUSH THROUGH
SOUTH FLORIDA BY EARLY THURSDAY MORNING WITH BETTER CHANCES FOR
SHOWERS. DID NOT INCLUDE A THUNDER MENTION AT THIS TIME DUE TO THE
TIMING OF THE FRONT BEING DURING THE EARLY MORNING HOURS...ACCORDING
TO THE ECMWF. THE GFS SOLUTION IS A BIT SLOWER BRINGING THE FRONT
INTO SOUTH FLORIDA LATER IN THE AFTERNOON. IF THIS SOLUTION PANS
OUT...THE COMBINATION OF FRONTAL FORCING AND DAYTIME HEATING WOULD
YIELD THUNDERSTORM DEVELOPMENT. WILL NEED TO WATCH SUBSEQUENT MODEL
RUNS CLOSELY FOR TIMING CHANGES.
SHOWERS WILL LINGER THROUGH FRIDAY BEFORE DRY WEATHER RETURNS FOR
THE WEEKEND. UPPER RIDGING WILL THEN BUILD ACROSS THE AREA FROM THE
SOUTH KEEPING TEMPERATURES ABOVE NORMAL.
MARINE...
WINDS OF 10 KNOTS OR LESS ARE EXPECTED TO CONTINUE ACROSS THE
REGIONAL WATERS WITH SEAS OF 2 FEET OR LESS. A COLD FRONT IS
FORECAST TO AFFECT THE REGIONAL WATERS EARLY THURSDAY WITH AN
INCREASE IN WINDS AND SEAS EXPECTED. HOWEVER...HAZARDOUS SEAS ARE
NOT FORECAST FOR THIS PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 81 63 82 65 / 30 10 20 40
FORT LAUDERDALE 82 66 82 69 / 30 10 20 30
MIAMI 83 67 83 69 / 30 10 20 30
NAPLES 79 62 80 66 / 20 - 20 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...84/AK
AVIATION/RADAR...85/AG
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1044 PM EST WED FEB 26 2014
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE WELL OFFSHORE TONIGHT. A PRESSURE
RIDGE MOVING INTO THE AREA WILL DOMINATE THROUGH FRIDAY. AN UPPER-
LEVEL DISTURBANCE WILL BRING A CHANCE OF SHOWERS FRIDAY NIGHT
AND SATURDAY. THE NEXT FRONT WILL AFFECT OUR REGION EARLY NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
REMAINING SHOWERS HAVE MOVED TO THE COAST WITH CLEARING BEGINNING
TO ENTER THE CENTRAL MIDLANDS. UPPER LEVEL TROUGH CURRENTLY OVER
THE FORECAST AREA WILL SWING OFFSHORE OVER THE NEXT SEVERAL HOURS
AIDING IN PUSHING THE CLOUDS SOUTH OF THE AREA AND USHERING IN
COOLER AND DRIER AIR. TEMPERATURES HAVE ALREADY FALLEN INTO THE
MIDDLE 30S TO LOWER 40S AND OVERNIGHT LOWS REMAIN ON TRACK FOR THE
UPPER 20S TO AROUND 30 OVER THE WESTERN AND CENTRAL MIDLANDS WITH
LOWER 30S ELSEWHERE.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
THURSDAY THROUGH THURSDAY NIGHT...A BROAD UPPER TROUGH WILL MOVE
OVER THE EASTERN CONUS ON THURSDAY PROMOTING WEST-NORTHWESTERLY
FLOW ALOFT. AT THE SURFACE...LOW PRESSURE OVER THE GREAT LAKES
REGION WILL BRING A DRY REINFORCING COLD FRONT THROUGH THE MIDLANDS
AND CSRA DURING THE AFTERNOON/EVENING. TEMPERATURES WILL MAX OUT IN
THE UPPER 50S NORTH TO NEAR 60 SOUTH UNDER SUNNY SKIES AND DOWN SLOPE
FLOW. SURFACE WINDS WILL ROTATE FROM WESTERLY TO NORTHEASTERLY
BEHIND THE FRONT THURSDAY NIGHT AS HIGH PRESSURE BUILDS INTO THE
AREA. ANOTHER CHILLY NIGHT WITH LOWS IN THE MID 20S TO NEAR 30.
FRIDAY THROUGH FRIDAY NIGHT...THE UPPER TROUGH WILL BE OFF THE
COAST BY FRIDAY WITH UPPER FLOW BECOMING ZONAL. SURFACE HIGH
PRESSURE WILL SHIFT OVER THE MID-ATLANTIC AND WEDGE INTO THE
FORECAST AREA FOR FRIDAY. CLOUD COVER WILL INCREASE FRIDAY INTO
FRIDAY NIGHT. TEMPERATURES WILL MAX OUT IN THE UPPER 40S NORTH TO
MID 50S SOUTH. A WEAK SHORTWAVE TROUGH WILL BRING A CHANCE OF
PRECIPITATION FRIDAY NIGHT INTO EARLY SATURDAY. KEPT HIGHEST POPS
IN THE NORTHERN MIDLANDS WHERE BEST FORCING APPEARS TO BE. MOSTLY
CLOUDY SKIES OVERNIGHT WITH LOW TEMPERATURES IN THE LOWER 30S TO
NEAR 40.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
SHORTWAVE TROUGH WILL SHIFT EAST SATURDAY MORNING AS A WEAK UPPER
RIDGE BUILDS OVER THE SOUTHEAST CONUS THROUGH SUNDAY WITH DRY
WEATHER EXPECTED. LEANED TOWARD COOLER TEMPERATURE GUIDANCE ON
SATURDAY AS THE WEDGE MAY BE SLOW TO ERODE. WARM UP EXPECTED
SUNDAY AND MONDAY AHEAD OF THE NEXT APPROACHING SYSTEM. THE UPPER
RIDGE WILL SHIFT EAST MONDAY AS A TROUGH DEEPENS OVER THE CENTRAL
CONUS. THE ECMWF AND GFS APPEAR TO BE COMING INTO BETTER AGREEMENT
WITH THE NEXT SYSTEM. THE BEST CHANCE FOR PRECIPITATION LOOKS TO
BE MONDAY NIGHT INTO TUESDAY MORNING. COOLER TEMPERATURES
EXPECTED BEHIND THE FRONTAL PASSAGE FOR TUESDAY AND WEDNESDAY.
&&
.AVIATION /04Z THURSDAY THROUGH MONDAY/...
GENERAL DRYING HAS OCCURRED AS THE OFFSHORE FRONT SHIFTED FARTHER
EASTWARD. HOWEVER...CONTINUED HIGH LOW-LEVEL MOISTURE ASSOCIATED
WITH THE RECENT RAIN AND LIGHT WIND MAY HELP SUPPORT FOG DURING
THE EARLY MORNING HOURS. LIMITING FACTORS FOR FOG ARE WEAK DRY-
AIR ADVECTION AND LINGERING HIGH CLOUDINESS. THE GUIDANCE WAS
MIXED WITH THE SREF AND GFS MOS MAINTAINING MAINLY VFR CONDITIONS.
THE 23Z HRRR INDICATED PATCHES OF IFR FOG. USED THE NAM MOS AND
FORECASTED A PERIOD OF MVFR OR IFR FOG WITH THE MORE PESSIMISTIC
CONDITIONS CONFINED TO OGB WHERE THE LATEST ANALYSIS OF DEW POINT
TEMPERATURES AND RAINFALL AMOUNTS SUPPORTED HIGHER LOW-LEVEL
MOISTURE. HEATING AND MIXING WITH DRY-AIR ADVECTION SUPPORTED VFR
CONDITIONS BEGINNING 13 TO 14Z. WE HAVE HIGH CONFIDENCE WITH THE
VFR FORECAST AFTER 14Z.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
921 PM EST WED FEB 26 2014
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE WELL OFFSHORE TONIGHT. A PRESSURE
RIDGE MOVING INTO THE AREA WILL DOMINATE THROUGH FRIDAY. AN UPPER-
LEVEL DISTURBANCE WILL BRING A CHANCE OF SHOWERS FRIDAY NIGHT
AND SATURDAY. THE NEXT FRONT WILL AFFECT OUR REGION EARLY NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
CLEARING HAS BEGUN TO MOVE INTO THE WESTERN MIDLANDS AND WILL
EXTEND INTO THE CENTRAL MIDLANDS OVER THE NEXT COUPLE OF HOURS AND
EASTERN MIDLANDS LATE THIS EVENING. THIS WILL RESULT IN MOSTLY
CLEAR SKIES OVERNIGHT AND WITH COLD AIR ADVECTION OVERTAKING THE
FORECAST AREA PRODUCE GOOD RADIATIONAL COOLING. TEMPERATURES WILL
DROP SLOWLY BUT STEADILY AS THE CLOUD DISSIPATE WITH OVERNIGHT
LOWS RANGING FROM THE UPPER 20S OVER THE WESTERN MIDLANDS TO THE
LOWER 30S IN THE EASTERN MIDLANDS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
THURSDAY THROUGH THURSDAY NIGHT...A BROAD UPPER TROUGH WILL MOVE
OVER THE EASTERN CONUS ON THURSDAY PROMOTING WEST-NORTHWESTERLY
FLOW ALOFT. AT THE SURFACE...LOW PRESSURE OVER THE GREAT LAKES
REGION WILL BRING A DRY REINFORCING COLD FRONT THROUGH THE MIDLANDS
AND CSRA DURING THE AFTERNOON/EVENING. TEMPERATURES WILL MAX OUT IN
THE UPPER 50S NORTH TO NEAR 60 SOUTH UNDER SUNNY SKIES AND DOWN SLOPE
FLOW. SURFACE WINDS WILL ROTATE FROM WESTERLY TO NORTHEASTERLY
BEHIND THE FRONT THURSDAY NIGHT AS HIGH PRESSURE BUILDS INTO THE
AREA. ANOTHER CHILLY NIGHT WITH LOWS IN THE MID 20S TO NEAR 30.
FRIDAY THROUGH FRIDAY NIGHT...THE UPPER TROUGH WILL BE OFF THE
COAST BY FRIDAY WITH UPPER FLOW BECOMING ZONAL. SURFACE HIGH
PRESSURE WILL SHIFT OVER THE MID-ATLANTIC AND WEDGE INTO THE
FORECAST AREA FOR FRIDAY. CLOUD COVER WILL INCREASE FRIDAY INTO
FRIDAY NIGHT. TEMPERATURES WILL MAX OUT IN THE UPPER 40S NORTH TO
MID 50S SOUTH. A WEAK SHORTWAVE TROUGH WILL BRING A CHANCE OF
PRECIPITATION FRIDAY NIGHT INTO EARLY SATURDAY. KEPT HIGHEST POPS
IN THE NORTHERN MIDLANDS WHERE BEST FORCING APPEARS TO BE. MOSTLY
CLOUDY SKIES OVERNIGHT WITH LOW TEMPERATURES IN THE LOWER 30S TO
NEAR 40.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
SHORTWAVE TROUGH WILL SHIFT EAST SATURDAY MORNING AS A WEAK UPPER
RIDGE BUILDS OVER THE SOUTHEAST CONUS THROUGH SUNDAY WITH DRY
WEATHER EXPECTED. LEANED TOWARD COOLER TEMPERATURE GUIDANCE ON
SATURDAY AS THE WEDGE MAY BE SLOW TO ERODE. WARM UP EXPECTED
SUNDAY AND MONDAY AHEAD OF THE NEXT APPROACHING SYSTEM. THE UPPER
RIDGE WILL SHIFT EAST MONDAY AS A TROUGH DEEPENS OVER THE CENTRAL
CONUS. THE ECMWF AND GFS APPEAR TO BE COMING INTO BETTER AGREEMENT
WITH THE NEXT SYSTEM. THE BEST CHANCE FOR PRECIPITATION LOOKS TO
BE MONDAY NIGHT INTO TUESDAY MORNING. COOLER TEMPERATURES
EXPECTED BEHIND THE FRONTAL PASSAGE FOR TUESDAY AND WEDNESDAY.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
GENERAL DRYING HAS OCCURRED AS THE OFFSHORE FRONT SHIFTED FARTHER
EASTWARD. HOWEVER...CONTINUED HIGH LOW-LEVEL MOISTURE ASSOCIATED
WITH THE RECENT RAIN AND LIGHT WIND MAY HELP SUPPORT FOG DURING
THE EARLY MORNING HOURS. LIMITING FACTORS FOR FOG ARE WEAK DRY-
AIR ADVECTION AND LINGERING HIGH CLOUDINESS. THE GUIDANCE WAS
MIXED WITH THE SREF AND GFS MOS MAINTAINING MAINLY VFR CONDITIONS.
THE 23Z HRRR INDICATED PATCHES OF IFR FOG. USED THE NAM MOS AND
FORECASTED A PERIOD OF MVFR OR IFR FOG WITH THE MORE PESSIMISTIC
CONDITIONS CONFINED TO OGB WHERE THE LATEST ANALYSIS OF DEW POINT
TEMPERATURES AND RAINFALL AMOUNTS SUPPORTED HIGHER LOW-LEVEL
MOISTURE. HEATING AND MIXING WITH DRY-AIR ADVECTION SUPPORTED VFR
CONDITIONS BEGINNING 13 TO 14Z. WE HAVE HIGH CONFIDENCE WITH THE
VFR FORECAST AFTER 14Z.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1001 AM EST TUE FEB 25 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BE OVER THE AREA THROUGH TODAY. A GULF
COAST LOW PRESSURE SYSTEM WILL MOVE EAST THROUGH GEORGIA AND
FLORIDA TONIGHT INTO WEDNESDAY BRINGING A CHANCE OF RAIN TO
OUR AREA. DRY AND COOLER WEATHER IS EXPECTED THURSDAY AND FRIDAY
WITH ANOTHER CHANCE OF RAIN EARLY SATURDAY WITH A FAST MOVING
SYSTEM.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK SURFACE HIGH PRESSURE REMAINS OVER THE AREA TODAY AS A
DE-AMPLIFYING SHORTWAVE TROUGH MOVES EASTWARD ACROSS THE TENNESSEE
VALLEY AND CROSSES THE FORECAST AREA LATER TODAY. RADAR SHOWING
CLUSTER OF SHOWERS OVER NORTH GEORGIA MOVING TOWARD THE PIEDMONT
AND CSRA. AIR MASS IS RELATIVELY DRY IN THE LOW LEVELS SO EXPECT
PRECIPITATION TO DIMINISH TO THE EAST. LATEST HRRR GUIDANCE HOWEVER
SUGGESTS A FEW SHOWERS WILL MOVE INTO THE PIEDMONT AND POSSIBLY
MIDLANDS LATER THIS MORNING...SO INCREASED POPS TO CHANCE/SLIGHT
CHANCE WEST OF CAE...QPF WILL BE LIGHT. TEMPERATURES WILL BE
SLIGHTLY COOLER THAN ON MONDAY DUE TO THE INCREASING CLOUDS...IN
THE 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
CHANCES OF RAIN INCREASE TONIGHT AS BROAD UPPER TROUGH SINKS
ACROSS THE GREAT LAKES AND OHIO VALLEY REGION DRIVING A COLD FRONT
THROUGH THE FORECAST AREA EARLY WEDNESDAY MORNING BEFORE HIGH
PRESSURE BUILDS IN AT THE SURFACE BEHIND THE FRONT WEDNESDAY
AFTERNOON. WESTERLY LOW LEVEL FLOW AHEAD OF THE SHORTWAVE AND
FRONT IS FORECAST TO BACK MORE SOUTHWESTERLY THIS EVENING ALLOWING
FOR ATMOSPHERIC MOISTURE TO INCREASE WITH FLOW OFF THE WESTERN
GULF OF MEXICO. HOWEVER...THE TIME FRAME FOR SIGNIFICANT MOISTURE
TO MOVE INTO THE REGION BEFORE THE FRONT ARRIVES IS SHORT AND A
LIMITING FACTOR DESPITE MODERATE UPPER DYNAMICS ARRIVING AROUND
THE 12Z TIME FRAME AS THE NORTHERN AND SOUTHERN STREAM JETS COUPLE
TO PROVIDE STRONG OMEGA AND UPWARD VERTICAL MOTION OVER THE
FORECAST AREA.
HAVE INCREASED POPS A BIT TO LOW LIKELY ACROSS THE SOUTHEASTERN
MIDLANDS AND CSRA FROM LATE TONIGHT INTO WEDNESDAY MORNING WITH A
GRADIENT TO LOWER POPS TO THE NORTHWEST WHERE MOISTURE WILL NOT BE
AS GREAT. STILL FIGURE THE BEST TIME FRAME FOR HIGHEST POPS WILL
BE FROM 09Z-15Z WITH CHANCES OF RAIN DECREASING FROM NORTHWEST TO
SOUTHEAST THROUGH THE DAY WEDNESDAY. TEMPERATURES WILL BE MUCH
COOLER WEDNESDAY COMPARED TO TUESDAY WITH COLD ADVECTION TAKING
PLACE DURING THE DAY DESPITE SOME CLEARING SKIES BY AFTERNOON.
COOL AND DRY SURFACE HIGH PRESSURE BUILDS OVER THE AREA WEDNESDAY
NIGHT INTO THURSDAY PROVIDING DRY WEATHER AND BELOW NORMAL
TEMPERATURES. LOWS WEDNESDAY NIGHT WILL BE QUITE COOL AND THE
COLDEST WE HAVE SEEN IN A COUPLE OF WEEK AS TEMPERATURES FALL INTO
THE 20S. HIGHS ON THURSDAY UNDER MOSTLY SUNNY SKIES WILL BE IN THE
MID TO UPPER 50S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
MEDIUM RANGE GUIDANCE HAS REMAINED FAIRLY CONSISTENT SHOWING
ANOTHER FAST MOVING UPPER TROUGH CROSSING THE FORECAST AREA FRIDAY
NIGHT AND SATURDAY BRINGING ANOTHER CHANCE OF RAIN TO THE REGION.
THE TRACK OF THE SYSTEM AND ASSOCIATED MOISTURE APPEAR TO BE A BIT
FURTHER NORTH SO HAVE LOWERED POPS A BIT THIS PERIOD. MODEL TRENDS
OF A DEVELOPING STORM SYSTEM OVER THE PLAINS SUN/MON LEAD TO
SOUTHWESTERLY FLOW ALOFT OVER THE SOUTHEAST AND POSSIBLE WARM
ADVECTION IN THE LOWER LEVELS. HAVE TRENDED TEMPERATURES A BIT
WARMER ON THESE DAYS BUT IF TRENDS CONTINUE THESE TEMPERATURES MAY
NEED TO CONTINUE TO BE RAISED WARMER. HOWEVER THIS IS A LOW
CONFIDENCE FORECAST GIVEN PLENTY OF SPREAD IN THE ENSEMBLES AND
DIFFERENCES IN TIMING OF THE OPERATIONAL RUNS.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS STILL FORECAST THROUGH THE TAF PERIOD.
SCATTERED STRATO-CU AND MID LEVEL CLOUDS WILL SPREAD ACROSS THE
AREA THROUGH THE AFTERNOON. PATCHY LIGHT SHOWERS OVER THE UPSTATE
AND NORTH GEORGIA WILL WEAKEN AS THEY MOVE EAST INTO DRIER AIR
MASS. LATEST RAP AND NAM INDICATING BRIEF GUSTY WINDS WEST BEHIND
WEAK SHORT WAVE TROUGH THIS AFTERNOON.
INTO THE OVERNIGHT PERIOD...MODELS AND BUFKIT SOUNDINGS SHOWING
MOISTURE CONTINUING TO INCREASE IN THE MID LEVELS...WHICH SHOULD
HELP TO LOWER THE CEILINGS AND CAUSE THEM TO GO MORE BROKEN LATE
THIS EVENING AND OVERNIGHT...ALTHOUGH THEY SHOULD STILL REMAIN IN
THE VFR CATEGORY. MODELS ALSO BEGINNING TO INDICATE WEAK LIFT
ASSOCIATED WITH AN APPROACHING FRONT AFTER 06Z TONIGHT...WITH AN
INCREASING CHANCE FOR RAIN SHOWERS. HAVE INCLUDED 6SM -RA
BEGINNING AT 06Z AT AGS/DNL...AND AFTER 08Z AT CAE/CUB/OGB FOR
THIS INCREASED CHANCE FOR RAIN. CONFIDENCE NOT EXTREMELY HIGH YET
FOR ANY KIND OF SIGNIFICANT RAINFALL. WINDS WILL BE LIGHT AND
VARIABLE THROUGH 17Z...THEN BECOME WESTERLY AROUND 7 KNOTS FOR THE
AFTERNOON AND EARLY EVENING...THEN BACK TO LIGHT AND VARIABLE
AFTER SUNSET.
EXTENDED AVIATION OUTLOOK... WIDESPREAD MVFR...POSSIBLE
IFR...CONDITIONS EXPECTED BY WEDNESDAY MORNING THROUGH MID-DAY
WEDNESDAY ASSOCIATED WITH A FRONTAL SYSTEM CROSSING THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
810 AM EST TUE FEB 25 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BE OVER THE AREA THROUGH TODAY. A GULF
COAST LOW PRESSURE SYSTEM WILL MOVE EAST THROUGH GEORGIA AND
FLORIDA TONIGHT INTO WEDNESDAY BRINGING A CHANCE OF RAIN TO
OUR AREA. DRY AND COOLER WEATHER IS EXPECTED THURSDAY AND FRIDAY
WITH ANOTHER CHANCE OF RAIN EARLY SATURDAY WITH A FAST MOVING
SYSTEM.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK SURFACE HIGH PRESSURE REMAINS OVER THE AREA TODAY AS A
DE-AMPLIFYING SHORTWAVE TROUGH MOVES EASTWARD ACROSS THE TENNESSEE
VALLEY AND CROSSES THE FORECAST AREA LATER TODAY. RADAR SHOWING
CLUSTER OF SHOWERS OVER NORTH GEORGIA MOVING TOWARD THE PIEDMONT
AND CSRA. AIR MASS IS RELATIVELY DRY IN THE LOW LEVELS SO EXPECT
PRECIPITATION TO DIMINISH TO THE EAST. LATEST HRRR GUIDANCE HOWEVER
SUGGESTS A FEW SHOWERS WILL MOVE INTO THE PIEDMONT AND POSSIBLY
MIDLANDS LATER THIS MORNING...SO INCREASED POPS TO CHANCE/SLIGHT
CHANCE WEST OF CAE...QPF WILL BE LIGHT. TEMPERATURES WILL BE
SLIGHTLY COOLER THAN ON MONDAY DUE TO THE INCREASING CLOUDS...IN
THE 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
CHANCES OF RAIN INCREASE TONIGHT AS BROAD UPPER TROUGH SINKS
ACROSS THE GREAT LAKES AND OHIO VALLEY REGION DRIVING A COLD FRONT
THROUGH THE FORECAST AREA EARLY WEDNESDAY MORNING BEFORE HIGH
PRESSURE BUILDS IN AT THE SURFACE BEHIND THE FRONT WEDNESDAY
AFTERNOON. WESTERLY LOW LEVEL FLOW AHEAD OF THE SHORTWAVE AND
FRONT IS FORECAST TO BACK MORE SOUTHWESTERLY THIS EVENING ALLOWING
FOR ATMOSPHERIC MOISTURE TO INCREASE WITH FLOW OFF THE WESTERN
GULF OF MEXICO. HOWEVER...THE TIME FRAME FOR SIGNIFICANT MOISTURE
TO MOVE INTO THE REGION BEFORE THE FRONT ARRIVES IS SHORT AND A
LIMITING FACTOR DESPITE MODERATE UPPER DYNAMICS ARRIVING AROUND
THE 12Z TIME FRAME AS THE NORTHERN AND SOUTHERN STREAM JETS COUPLE
TO PROVIDE STRONG OMEGA AND UPWARD VERTICAL MOTION OVER THE
FORECAST AREA.
HAVE INCREASED POPS A BIT TO LOW LIKELY ACROSS THE SOUTHEASTERN
MIDLANDS AND CSRA FROM LATE TONIGHT INTO WEDNESDAY MORNING WITH A
GRADIENT TO LOWER POPS TO THE NORTHWEST WHERE MOISTURE WILL NOT BE
AS GREAT. STILL FIGURE THE BEST TIME FRAME FOR HIGHEST POPS WILL
BE FROM 09Z-15Z WITH CHANCES OF RAIN DECREASING FROM NORTHWEST TO
SOUTHEAST THROUGH THE DAY WEDNESDAY. TEMPERATURES WILL BE MUCH
COOLER WEDNESDAY COMPARED TO TUESDAY WITH COLD ADVECTION TAKING
PLACE DURING THE DAY DESPITE SOME CLEARING SKIES BY AFTERNOON.
COOL AND DRY SURFACE HIGH PRESSURE BUILDS OVER THE AREA WEDNESDAY
NIGHT INTO THURSDAY PROVIDING DRY WEATHER AND BELOW NORMAL
TEMPERATURES. LOWS WEDNESDAY NIGHT WILL BE QUITE COOL AND THE
COLDEST WE HAVE SEEN IN A COUPLE OF WEEK AS TEMPERATURES FALL INTO
THE 20S. HIGHS ON THURSDAY UNDER MOSTLY SUNNY SKIES WILL BE IN THE
MID TO UPPER 50S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
MEDIUM RANGE GUIDANCE HAS REMAINED FAIRLY CONSISTENT SHOWING
ANOTHER FAST MOVING UPPER TROUGH CROSSING THE FORECAST AREA FRIDAY
NIGHT AND SATURDAY BRINGING ANOTHER CHANCE OF RAIN TO THE REGION.
THE TRACK OF THE SYSTEM AND ASSOCIATED MOISTURE APPEAR TO BE A BIT
FURTHER NORTH SO HAVE LOWERED POPS A BIT THIS PERIOD. MODEL TRENDS
OF A DEVELOPING STORM SYSTEM OVER THE PLAINS SUN/MON LEAD TO
SOUTHWESTERLY FLOW ALOFT OVER THE SOUTHEAST AND POSSIBLE WARM
ADVECTION IN THE LOWER LEVELS. HAVE TRENDED TEMPERATURES A BIT
WARMER ON THESE DAYS BUT IF TRENDS CONTINUE THESE TEMPERATURES MAY
NEED TO CONTINUE TO BE RAISED WARMER. HOWEVER THIS IS A LOW
CONFIDENCE FORECAST GIVEN PLENTY OF SPREAD IN THE ENSEMBLES AND
DIFFERENCES IN TIMING OF THE OPERATIONAL RUNS.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS STILL FORECAST THROUGH THE TAF PERIOD.
HIGH CLOUDINESS WILL CONTINUE TO MOVE ACROSS THE REGION THROUGH THE
PERIOD AS WEAK UPPER LEVEL WAVES MOVE THROUGH THE MAIN FLOW ALOFT.
SOME MID-LEVEL MOISTURE WILL ATTEMPT TO MOVE EAST OF THE MOUNTAINS
THROUGH THE DAY...BUT DOWNSLOPING FLOW SHOULD HELP TO KEEP ANY LOW
AND MID CLOUDS SCATTERED AT BEST AND SHOULD HELP DISSIPATE ANY LIGHT
SHOWERS EAST OF THE MOUNTAINS. INTO THE OVERNIGHT PERIOD...MODELS
AND BUFKIT SOUNDINGS SHOWING MOISTURE CONTINUING TO INCREASE IN THE
MID LEVELS...WHICH SHOULD HELP TO LOWER THE CEILINGS AND CAUSE THEM
TO GO MORE BROKEN LATE THIS EVENING AND OVERNIGHT...ALTHOUGH THEY
SHOULD STILL REMAIN IN THE VFR CATEGORY. MODELS ALSO BEGINNING TO
INDICATE WEAK LIFT ASSOCIATED WITH AN APPROACHING FRONT AFTER 06Z
TONIGHT...WITH AN INCREASING CHANCE FOR RAIN SHOWERS. HAVE INCLUDED
6SM -RA BEGINNING AT 06Z AT AGS/DNL...AND AFTER 08Z AT CAE/CUB/OGB
FOR THIS INCREASED CHANCE FOR RAIN. CONFIDENCE NOT EXTREMELY HIGH
YET FOR ANY KIND OF SIGNIFICANT RAINFALL. WINDS WILL BE LIGHT AND
VARIABLE THROUGH 17Z...THEN BECOME WESTERLY AROUND 7 KNOTS FOR THE
AFTERNOON AND EARLY EVENING...THEN BACK TO LIGHT AND VARIABLE AFTER
SUNSET.
EXTENDED AVIATION OUTLOOK... WIDESPREAD MVFR...POSSIBLE
IFR...CONDITIONS EXPECTED BY WEDNESDAY MORNING THROUGH MID-DAY
WEDNESDAY ASSOCIATED WITH A FRONTAL SYSTEM CROSSING THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
646 AM EST TUE FEB 25 2014
.PREV DISCUSSION... /ISSUED 422 AM EST TUE FEB 25 2014/
SHORT TERM /TODAY THROUGH WEDNESDAY/...
SURFACE ARCTIC HIGH PRESSURE CONTINUES TO MOVE SOUTHEAST THROUGH THE
PLAIN STATES ATTM AND IS EXPECTED TO SURGE INTO THE REGION LATE TUES
NIGHT INTO EARLY WED. AT THE SAME TIME A WEAK DISTURBANCE WILL BE
ROTATING THROUGH THE SOUTHERN PERIPHERY OF THE LARGER VORTEX
DROPPING SOUTH INTO THE GREAT LAKES REGION. FORECAST CHALLENGE IS
TIMING WRT MOISTURE OVERRUNNING THE COLD AIR BEHIND THE FRONT AND
THE SMALL WINDOW OF OPPORTUNITY FOR SNOW OR A RASN MIX. FROM ROME
TO CARTERSVILLE TO GAINESVILLE....NAM AND GFS FORECAST SOUNDINGS
SHOW MODEST SATURATION BETWEEN 06Z AND 12Z WED AND TEMPS AT OR BELOW
FREEZING INDICATING A A RASN MIX AT THE ONSET AND CHANGING TO ALL
SNOW...ALBEIT LIGHT..BY 09Z AND ENDING BY 12Z. MODELS STRUGGLING TO
LIFT MOISTURE FURTHER NORTH ACROSS FAR NORTH GA...HOWEVER...MODEL
SOUNDINGS MUCH COLDER THERE SO WHATEVER PRECIP WOULD FALL SHOULD BE
ALL OR MOSTLY SNOW. ISENTROPIC ANALYSIS IN THE GFS AT THE 300K LEVEL
FROM 06Z TO 12Z DOES SHOW SOME LIFT WITHIN A SATURATED LAYER AOA
700MB SO PRECIP CERTAINLY CANNOT BE RULED OUT FAR NORTH GA.
OVERALL...ALL MODEL QPFS ARE VERY LIGHT...I.E. LESS THAN 0.1IN OF
LIQUID FOR MOST AREAS NORTH OF I20 SO TOTAL SNOW AMOUNTS SHOULD
REMAIN LESS THAN 0.5IN MOST LOCATIONS. HOWEVER..THAT DOESNT MEAN THE
THREAT IS NEGLIGIBLE. HAVE TENDED TO NOT BUY INTO GUIDANCE TEMPS
OVERNIGHT DURING THE PRECIP PERIOD DUE TO THE LIKELIHOOD OF
WETBULBING SO HAVE TRENDED TEMPS CLOSER TO THE WEBBULB TEMPS
OVERNIGHT WED. THIS METHOD DROPS THE FREEZING LINE DOWN TO THE
NORTH ATL METRO WITH THE ATL METRO HOVERING IN THE 33 TO 34 RANGE.
WITH THE PRECIP FALLING OVERNIGHT AND WETBULB TEMPS RIGHT AROUND
FREEZING...CANNOT RULE OUT SOME BLACK ICE PROBLEMS PARTICULARLY FAR
NORTH METRO AND ALL OF NORTH GA..BUT WILL HAVE TO WATCH FUTURE RUNS
TO GET A HANDLE OF THE TIMING OF COLDER AND DRIER AIR ADVANCEMENT
INTO THE REGION. FURTHER SOUTH IN THE I20 CORRIDOR THINK MOST
PRECIP WILL BE A COLD RAIN BUT HAVE KEPT A FLURRY/RAIN MIX IN FOR
THE ATL METRO FOR A 2 TO 3 HOUR PERIOD WHERE THAT CANNOT BE RULED
OUT GIVEN THE TEMP PROFILE DURING THE 09Z TO 12Z WINDOW. DO NOT
EXPECT ANY IMPACTS FROM THAT UNLESS THE COLD AIR ADVANCES A BIT
FASTER THAN CURRENT PROJECTIONS. DEF WORTH KEEPING AN EYE ON TO SEE
MODEL TRENDS.
SOUTH OF I20..PRECIP CHANCES ARE MUCH HIGHER AND IN THE LIKELY
CATEGORY THROUGH EARLY TO MID AM WED BEFORE CLEARING OUT AREA WIDE
BY EARLY AFTN.
STRONG NORTHWEST WINDS MOVING IN DURING THE DAY WEDNESDAY WITH 15 TO
20 DEGREE BELOW NORMAL TEMPS EXPECTED.
30
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
ARCTIC HIGH PRESSURE BUILDS INTO THE REGION BEHIND THE SHORT-TERM
FRONTAL PASSAGE...WITH TEMPERATURES NOTICEABLY COOLER THAN EARLIER
IN THE WEEK. THIS HIGH PRESSURE REMAINS IN PLACE THROUGH THE
LATTER HALF OF THE WEEK AHEAD OF THE NEXT DISTURBANCE MOVING IN
EARLY SATURDAY...WITH GRADUALLY WARMING TEMPERATURES EXTENDED
PERIOD MODEL CONSENSUS GENERALLY GOOD WITH THIS EARLY WEEKEND
SYSTEM...AND HAVE CONTINUED WITH CHANCE POPS ACROSS A LARGE
PORTION OF THE CWA FOR FRIDAY NIGHT INTO SATURDAY MORNING...WITH
THE BEST CHANCES IN FAR NW GA. HIGH PRESSURE RETURNS TO THE AREA
SUNDAY...AND IT IS AT THIS POINT THAT EXTENDED MODEL SOLUTIONS
DIVERGE AND UNCERTAINTY INCREASES. THE ECMWF PULLS THE FRONT
THROUGH THE STATE LATE SUNDAY NIGHT...WHILE THE GFS DELAYS THE
ONSET UNTIL LATE MONDAY NIGHT...AFTER THE EUROPEAN CLEARS THE
PRECIPITATION FROM THE AREA. HAVE GENERALLY GONE WITH CHANCE POPS
SUNDAY NIGHT THROUGH THE DAY TUESDAY TO ACCOUNT FOR THE VARIED
SOLUTIONS...AND EXPECT AS WE GET IN TO LATE WEEK THE DURATION THE
CHANCE POPS WITH THIS FRONT WILL DECREASE.
JUST AS THE MODELS DIFFER IN THE PRECIP TIMING FOR LATE WEEKEND
AND EARLY NEXT WEEK...SO DO THE TEMPERATURES. HAVE RAISED SUNDAY
TEMPERATURES A FEW DEGREES FROM THE PREVIOUS FORECAST TO ACCOUNT
FOR THE EXPECTED SOUTHERLY FLOW AHEAD OF THE FRONTAL PASSAGE AND
THICKNESSES SUPPORTIVE OF HIGHS IN THE MID TO UPPER 60S. EVEN THE
CURRENT FORECAST TEMPERATURES MAY BE TOO COOL.
31
&&
.AVIATION...
12Z UPDATE...
NO MAJOR CHANGES FROM PREVIOUS FORECAST THINKING. WAS TEMPTED TO
ADD VCSH OR A TEMPO GROUP IN FOR THE BAND OF RAIN MOVING EAST-SOUTHEAST
OUT OF ALABAMA INTO NORTH GA. LATEST HRRR RUNS EVAPORATE THAT AREA
QUICKLY AS IT IMPEDES UPON DRY AIR ALOFT OVER GA. PREVIOUS RUNS
MAINTAINED SOME SHOWER ACTIVITY INTO THE I20 CORRIDOR. HAVE TAKEN
MENTION OF RAIN OUT THIS MORNING THINKING THAT IT WILL DRY UP AS
THE HRRR SUGGESTS...BUT MAY HAVE LATER SHIFTS AMEND IF IT DOES NOT
AS QUICKLY. OVERALL...MODELS DID NOT HANDLE THAT AREA WELL. CIGS
INCREASE THROUGH THE DAY...PARTICULARLY AFTER 16Z TO 18Z FOR MOST
TAF SITES. CONTINUED WITH PROB30 SHRA INTO MOST LOCATIONS 23Z TO
00Z AND EXPECT A GRADUAL INCREASE IN SHOWER ACTIVITY PARTICULARLY
AFTER 06Z THROUGH 12Z WITH A PRIME PERIOD 08Z THRU 11Z. HAVE
INSERTED SHRA AS PREVAILING FOR ATL DURING THAT TIME...AM STILL
HESITANT TO PUT A RASN MIX IN FOR ATLANTA AS ATL SEEMS TO BE THE
SOUTHERN EXTENT WHERE THERE WOULD BE ANY OR EVEN A SLIGHT CHANCE
FOR THAT TO OCCUR BASED ON LATEST FORECAST SOUNDINGS. WILL WAIT TO
SEE LATER RUNS AS CONFIDENCE STILL LOW. RMG TO GVL APPEARS TO HAVE
A HIGHER PROB OF SEEING A RASN MIX ALTHOUGH TOTAL AMOUNTS WILL BE
LOWER. BEST WINDOW FOR THIS...IF IT OCCURS PER NAM AND GFS
SOUNDINGS..IS 08Z TO 11Z.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM ON PRECIP NOT MAKING IT TO ATL THIS MORNING.
MEDIUM ON CIGS AND TIMING OF PRECIP ONSET TONIGHT.
HIGH ALL OTHER ELEMENTS.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 67 35 51 27 / 10 60 50 5
ATLANTA 63 33 43 25 / 10 60 50 0
BLAIRSVILLE 57 30 41 20 / 40 30 20 0
CARTERSVILLE 61 32 42 21 / 20 50 30 0
COLUMBUS 70 43 48 28 / 5 80 70 5
GAINESVILLE 62 32 46 26 / 10 50 30 0
MACON 72 45 49 26 / 5 70 70 5
ROME 59 32 41 20 / 30 50 30 0
PEACHTREE CITY 64 35 46 22 / 10 70 50 0
VIDALIA 75 50 52 36 / 5 60 80 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...30
LONG TERM....31
AVIATION...30
AREA FORECAST DISCUSSION
NWS BOISE ID
948 AM MST TUE FEB 25 2014
.DISCUSSION...FRONT REMAINS STATIONARY JUST TO THE NORTH OF THE
CWA THIS MORNING. MOISTURE AND SHOWERS ALONG THE FRONT WILL
DECREASE AS AN UPPER RIDGE AXIS TO OUR WEST BUILDS INTO OUR AREA.
RADAR ALREADY SHOWING A DECREASING TREND IN SHOWER COVERAGE ACROSS
THE NORTH AND THAT TREND WILL CONTINUE THROUGH THE AFTERNOON.
MORNING UPDATE WILL INCLUDE LOWER POPS AND LOWER QPF AMOUNTS
TODAY.
&&
.AVIATION...EXPECT MVFR/LOCAL LIFR CONDITIONS IN RAIN AND SNOW
OVER THE WEST CENTRAL IDAHO AND BOISE MOUNTAINS AND THE HIGHER
TERRAIN OF BAKER COUNTY THIS MORNING. SNOW LEVEL WILL BE NEAR 5K
FT MSL. CONDITIONS WILL GRADUALLY IMPROVE THROUGH THE
AFTERNOON...WITH MAINLY VFR TONIGHT. ELSEWHERE VFR WILL PREVAIL
WITH BROKEN TO OVERCAST CEILINGS ABOVE 10K FT MSL. SURFACE WINDS
WILL BE LIGHT. WINDS ALOFT WILL BE NORTHWEST UP TO 25 KTS AT 10K
FT MSL.
&&
.PREV DISCUSSION...
SHORT TERM...TODAY THROUGH WEDNESDAY...UPDATED HIGH TEMPERATURES
AS MORNING WEATHER BALLOON SOUNDING INDICATED ANOTHER 3 TO 5
DEGREES OF WARMING BELOW 10K FT MSL. /END UPDATE/ DEEP MOISTURE
AXIS ACROSS OREGON AND CENTRAL IDAHO WILL COMBINE WITH AN UPPER
LEVEL TROUGH DROPPING THROUGH THE NORTHERN ROCKIES FOR NUMEROUS
SHOWERS ACROSS THE WEST CENTRAL MOUNTAINS MAINLY THIS MORNING.
CLOUDINESS WILL DECREASE ACROSS SOUTHERN AREAS SO EXPECT ANOTHER
MILD LATE AFTERNOON WITH HIGHS IN THE 50S TO AROUND 60. PWAT ARE
ABOVE NORMAL AT 0.50 INCHES VS 0.33 INCHES BUT AMOUNTS WON`T BE
ENOUGH FOR ANY HEADLINES...MORE LIKE A HIGH POP/LOW QPF EVENT. THE
MORNING SNOW LEVEL AROUND 5500 FEET WILL RESULT IN A RAIN/SNOW MIX
AT MCCALL FROM 5 TO 9 AM THEN CHANGE BACK TO RAIN BEFORE TAPERING
THIS EVENING. HRRR AND 0Z/6Z NAM KEEP BANDED SHOWERS GOING AT
VARIOUS LOCATIONS ACROSS NE OREGON OR CENTRAL IDAHO THIS AFTERNOON
SO HAVE SCATTERED SHOWERS LATER TODAY IN THE HIGHER TERRAIN OF THE
PAYETTE NF/BOISE NF AS WELL AS SOUTH PARTS OF THE WALLOWA WHITMAN
FOREST IN OREGON. AS THE UPPER LEVEL RIDGE MOVES OVER THE AREA
TONIGHT THROUGH WEDNESDAY MORNING EXPECT DRY WX. WEDNESDAY...IN
THE AFTERNOON OVER OREGON AND LATE AFTERNOON OVER THE SW IDAHO
MOUNTAINS THERE SHOULD BE ENOUGH MOISTURE AN LIFT AHEAD OF THE
NEXT INCOMING SYSTEM FOR LOW CHANCES OF RAIN...AND HIGH MOUNTAIN
SNOW ABOVE 6500-7200 FEET. TEMPERATURES PEAK WEDNESDAY AROUND 8-12
DEGREES ABOVE NORMAL.
LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...FORECAST REMAINS ON
TRACK FOR AN ACTIVE PATTERN THROUGH EARLY NEXT WEEK. THE FIRST ROUND
OF PRECIPITATION WILL BEGIN WEDNESDAY NIGHT THROUGH THURSDAY AS A
WEAK UPPER TROUGH MOVES ACROSS THE REGION FROM THE SOUTHWEST TO
NORTHEAST. SNOW LEVELS REMAIN ABOVE 6000 FEET FOR MODERATE SNOW
ACCUMULATIONS ON THE MOUNTAIN PEAKS. LIGHT RAIN AMOUNTS EXPECTED IN
THE VALLEYS. A BRIEF BREAK ON FRIDAY WILL BE FOLLOWED BY MORE
SHOWERS OVER THE WEEKEND AS AN UPPER LEVEL TROUGH CROSSES CALIFORNIA
AND MOVES OVER THE GREAT BASIN. A MAJORITY OF GUIDANCE FAVORS THE
WARMER ECMWF INCLUDING MOST OF THE GFS ENSEMBLES MAKING THE
OPERATIONAL GFS THE ODD MODEL OUT. THE UPPER LOW WEAKENS AND SPLITS
AS IT MOVES INLAND ACROSS CALIFORNIA ON FRIDAY. THE NORTHERN SPLIT
MOVES ACROSS THE REGION ON SATURDAY KEEPING THE ARCTIC COLD FRONT
NORTH AND EAST OF THE AREA. EXPECT PRECIPITATION ACROSS THE AREA
THROUGH MONDAY WITH THE MOUNTAINS BEST CHANCE FOR SNOW ON SUNDAY.
TEMPERATURES WILL BE NEAR NORMAL TO SLIGHTLY ABOVE NORMAL.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&
$$
WEATHER.GOV/BOISE
DISCUSSION...BW
AVIATION.....JT
PREV SHORT TERM...VM
PREV LONG TERM....JS
AREA FORECAST DISCUSSION...CORRECTED
NWS BOISE ID
327 AM MST TUE FEB 25 2014
.SHORT TERM...TODAY THROUGH WEDNESDAY...UPDATED HIGH TEMPERATURES
AS MORNING WEATHER BALLOON SOUNDING INDICATED ANOTHER 3 TO 5
DEGREES OF WARMING BELOW 10K FT MSL. /END UPDATE/ DEEP MOISTURE
AXIS ACROSS OREGON AND CENTRAL IDAHO WILL COMBINE WITH AN UPPER
LEVEL TROUGH DROPPING THROUGH THE NORTHERN ROCKIES FOR NUMEROUS
SHOWERS ACROSS THE WEST CENTRAL MOUNTAINS MAINLY THIS MORNING.
CLOUDINESS WILL DECREASE ACROSS SOUTHERN AREAS SO EXPECT ANOTHER
MILD LATE AFTERNOON WITH HIGHS IN THE 50S TO AROUND 60. PWAT ARE
ABOVE NORMAL AT 0.50 INCHES VS 0.33 INCHES BUT AMOUNTS WON`T BE
ENOUGH FOR ANY HEADLINES...MORE LIKE A HIGH POP/LOW QPF EVENT. THE
MORNING SNOW LEVEL AROUND 5500 FEET WILL RESULT IN A RAIN/SNOW MIX
AT MCCALL FROM 5 TO 9 AM THEN CHANGE BACK TO RAIN BEFORE TAPERING
THIS EVENING. HRRR AND 0Z/6Z NAM KEEP BANDED SHOWERS GOING AT
VARIOUS LOCATIONS ACROSS NE OREGON OR CENTRAL IDAHO THIS AFTERNOON
SO HAVE SCATTERED SHOWERS LATER TODAY IN THE HIGHER TERRAIN OF THE
PAYETTE NF/BOISE NF AS WELL AS SOUTH PARTS OF THE WALLOWA WHITMAN
FOREST IN OREGON. AS THE UPPER LEVEL RIDGE MOVES OVER THE AREA
TONIGHT THROUGH WEDNESDAY MORNING EXPECT DRY WX. WEDNESDAY...IN
THE AFTERNOON OVER OREGON AND LATE AFTERNOON OVER THE SW IDAHO
MOUNTAINS THERE SHOULD BE ENOUGH MOISTURE AN LIFT AHEAD OF THE
NEXT INCOMING SYSTEM FOR LOW CHANCES OF RAIN...AND HIGH MOUNTAIN
SNOW ABOVE 6500-7200 FEET. TEMPERATURES PEAK WEDNESDAY AROUND 8-12
DEGREES ABOVE NORMAL.
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...FORECAST REMAINS ON
TRACK FOR AN ACTIVE PATTERN THROUGH EARLY NEXT WEEK. THE FIRST ROUND
OF PRECIPITATION WILL BEGIN WEDNESDAY NIGHT THROUGH THURSDAY AS A
WEAK UPPER TROUGH MOVES ACROSS THE REGION FROM THE SOUTHWEST TO
NORTHEAST. SNOW LEVELS REMAIN ABOVE 6000 FEET FOR MODERATE SNOW
ACCUMULATIONS ON THE MOUNTAIN PEAKS. LIGHT RAIN AMOUNTS EXPECTED IN
THE VALLEYS. A BRIEF BREAK ON FRIDAY WILL BE FOLLOWED BY MORE
SHOWERS OVER THE WEEKEND AS AN UPPER LEVEL TROUGH CROSSES CALIFORNIA
AND MOVES OVER THE GREAT BASIN. A MAJORITY OF GUIDANCE FAVORS THE
WARMER ECMWF INCLUDING MOST OF THE GFS ENSEMBLES MAKING THE
OPERATIONAL GFS THE ODD MODEL OUT. THE UPPER LOW WEAKENS AND SPLITS
AS IT MOVES INLAND ACROSS CALIFORNIA ON FRIDAY. THE NORTHERN SPLIT
MOVES ACROSS THE REGION ON SATURDAY KEEPING THE ARCTIC COLD FRONT
NORTH AND EAST OF THE AREA. EXPECT PRECIPITATION ACROSS THE AREA
THROUGH MONDAY WITH THE MOUNTAINS BEST CHANCE FOR SNOW ON SUNDAY.
TEMPERATURES WILL BE NEAR NORMAL TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION...MVFR CONDITIONS IN RAIN AND SNOW MAINLY ACROSS THE WEST
CENTRAL AND BOISE MOUNTAINS OF IDAHO AND THE HIGHER TERRAIN OF BAKER
COUNTY TODAY. PRECIPITATION WILL BE MOSTLY RAIN EVEN AT KBKE AND
KMYL WITH A MIX OF RAIN AND SNOW POSSIBLE THROUGH 15Z.
ELSEWHERE...VFR CONDITIONS WITH BROKEN TO OVERCAST CEILINGS RANGING
FROM 5K-10K FEET AGL ALONG WITH AREAS OF MOUNTAIN OBSCURATION.
SURFACE WINDS 10-15 KTS FROM THE WEST-NORTHWEST. WINDS ALOFT WILL BE
WESTERLY AROUND 20 KNOTS UP THROUGH 10K FEET MSL.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&
$$
WEATHER.GOV/BOISE
SHORT TERM...VM
LONG TERM....JS
AVIATION.....JS
AREA FORECAST DISCUSSION...CORRECTED
NWS GOODLAND KS
200 PM MST TUE FEB 25 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 113 PM MST TUE FEB 25 2014
MAIN FOCUS IN THE SHORT TERM WAS TEMPERATURES TODAY THROUGH
TOMORROW AND PRECIPITATION THIS AFTERNOON AND OVERNIGHT. HIGH
TEMPERATURES THIS AFTERNOON WERE ADJUSTED SINCE SOME LOCATIONS
REACHED THEIR HIGHS AROUND 18/19Z. AFTER 18Z COLDER AIR MOVED INTO
NORTHERN LOCATIONS WHERE TEMPERATURES HAVE REMAINED FAIRLY
STAGNANT OR INCREASED BY A DEGREE OR TWO. PORTIONS OF NORTHWEST
KANSAS AND EASTERN COLORADO ALONG AND SOUTH OF I-70 HAVE SEEN
TEMPERATURES IN THE UPPER TEENS TO MID 20S...BUT THIS APPEARS TO
BE THE PEAK OF TODAY`S HIGH TEMPERATURES AS THE COLDER AIR BEGINS
TO MOVE IN. SNOW HAS DEVELOPED OVER SOUTHWEST NEBRASKA AND IS
MOVING INTO NORTHWEST KANSAS ASSOCIATED WITH A FAIRLY STRONG AREA
OF FRONTOGENESIS. AS THE SHORTWAVE TROUGH IN MONTANA CONTINUES TO
PUSH SOUTHEAST AND THE STRONG AREA OF FRONTOGENESIS MOVES
SOUTHEAST AND THEN SOUTH...SNOWFALL WILL CONTINUE THROUGH THE
EVENING OVER MOST OF THE TRI-STATE REGION. THIS WILL BE A QUICK
MOVING WAVE AND THE GFS...NAM...AND RAP ALL SHOW PRECIPITATION OUT
OF THE FORECAST AREA BY 06Z. SINCE THE SYSTEM MOVES QUICKLY...SNOW
ACCUMULATIONS WILL ONLY BE AROUND HALF AN INCH SOUTH AND EAST TO 2
INCHES NORTH AND NORTHWEST. CLOUD COVER WILL STICK AROUND A LITTLE
AFTER 06Z...WITH MOST OF THE CWA BEING CLEAR BY 15Z. LOWS TONIGHT
WILL DROP DOWN INTO THE SINGLE DIGITS AS HIGH PRESSURE SETTLES
INTO THE CWA. NORTHERN AREAS WILL SEE LOWS AROUND 1 DEGREE ABOVE
ZERO TO NEAR ZERO WHILE AREAS FURTHER SOUTH AND WEST WILL SEE LOWS
AROUND 5 TO 10 ABOVE ZERO.
AS SURFACE HIGH PRESSURE SLIDES EAST-SOUTHEAST...ANOTHER SHORTWAVE
TROUGH WILL MOVE THROUGH. NO PRECIPITATION IS EXPECTED WITH THE
NEXT TROUGH SINCE DRIER AIR MOVES IN SO HAVE KEPT THE FORECAST DRY
FOR TOMORROW. TEMPERATURES WILL BE DIVIDED WITH HIGHS OVER THE
NORTHERN HALF OF THE TRI-STATE REGION IN THE UPPER 30S TO NEAR 40
AND THE SOUTHERN HALF/SOUTH-SOUTHWEST PORTION OF THE TRI-STATE
REGION IN THE LOW TO MID 40S. MODELS MAY HAVE BEEN PICKING UP ON
THE SNOW COVER IN THE NORTHERN AREA OF THE CWA WHICH IS WHY THE
TEMPERATURES THERE ARE A BIT LOWER. USED A COMBINATION OF CONSALL
AND SREF FOR TOMORROW`S TEMPERATURES TO TREND THEM DOWNWARD IN THE
SOUTHERN PORTIONS OF THE CWA SINCE THEY SEEMED TO BE TOO HIGH TO
ACCOUNT FOR ANY SNOWFALL THOSE AREAS MIGHT RECEIVE TONIGHT. WEST
TO SOUTHWEST WINDS TOMORROW COULD ALSO BECOME BREEZY AROUND 18Z AS
THE SHORTWAVE TROUGH PASSES THROUGH AND DAYTIME MIXING
INCREASES...BUT ONLY HAVE SUSTAINED WINDS AROUND 10 TO 20 MPH
WITH GUSTS AROUND 25 TO 30 MPH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 224 AM MST TUE FEB 25 2014
WEDNESDAY NIGHT-THURSDAY...PROGRESSIVE SHORTWAVE RIDGE SHOULD HELP
KEEP DRY CONDITIONS IN PLACE THROUGH THESE PERIODS...WITH A SLIGHT
MODERATION OF THE AIR MASS OVER OUR CWA AS STATIONARY FRONT ALONG
FRONT RANGE LIFTS EAST WITH LEE TROUGH DEVELOPMENT. HIGH TEMPS
THURSDAY SHOULD BE NEAR NORMAL FOR WESTERN LOCATIONS (MID 40S TO
NEAR 50F)...WITH COOLER TEMPS IN THE MID/UPPER 30S FURTHER
NORTHEAST.
THURSDAY NIGHT-FRIDAY...NEXT IN A SERIES OF QUICK MOVING SHORTWAVE
TROUGHS WILL MOVE ACROSS THE REGION WITH ARCTIC AIR MASS DROPPING
BACK OVER WESTERN KS. BEST CHANCE FOR MEASURABLE SNOW APPEARS TO BE
LATE THURSDAY NIGHT THROUGH FRIDAY MORNING...WHEN MODELS ARE
ADVERTISING BETTER LARGE SCALE ASCENT. TIMING OF COLD FRONT IS A
LITTLE SLOWER WITH MAIN CAA FRIDAY AFTERNOON...WHICH MAY RESULT IN
QUITE A GRADIENT FROM THE NORTH-SOUTH OVER OUR CWA (LIKELY FALLING
TEMPS ACROSS THE NORTH).
FRIDAY NIGHT-TUESDAY...DESPITE DIFFERENCES IN THE LARGE SALE PATTERN
THROUGH THE EXTENDED PERIODS...MODELS HAVE COME INTO BETTER
AGREEMENT ON STUBBORN ARCTIC AIR MASS REMAINING IN PLACE OVER OUR
CWA...WITH ECMWF NOW TRENDING EVEN COLDER THAN THE LAST 3 RUNS OF
THE GFS. REGARDING LARGE SCALE PATTERN...ECMWF SHOWS MORE OF A
QUASI-ZONAL PATTERN WITH LOWER HEIGHTS SHIFTED SOUTH...WHILE GFS
SHOWS MORE OF A SPLIT FLOW PATTERN WITH THE NORTHERN STREAM HOLDING
MORE INFLUENCE OVER OUR CWA. EITHER SOLUTION FAVORS REINFORCING SHOTS
OF COLD ARCTIC AND AND PROLONGED BELOW NORMAL TEMPERATURES THROUGH AT
LEAST EARLY NEXT WEEK...ALONG WITH A SERIES OF QUICK MOVING
SHORTWAVES PASSING THROUGH THE REGION.
I TRENDED HIGH/LOW TEMPS DOWN TO ACCOUNT FOR THE COLDER PATTERN
CURRENT MODEL RUNS ARE ZEROING IN ON. EXPECTED CLOUD COVER
COMPLICATING HIGHS/LOWS...AND THERE ARE STILL DIFFERENCES BETWEEN
MODELS ON MAGNITUDE OF COOLING...SO I DID NOT FAVOR THE COLDEST
GUIDANCE DURING THIS UPDATE. THE TYPE OF AIR MASS CURRENTLY
ADVERTISED BY EVEN THE "WARMER" GFS WOULD SUPPORT OVERNIGHT LOWS IN
THE SINGLE DIGITS BELOW ZERO OVER PARTS OF OUR CWA DESPITE CLOUD
COVER (AND IF WE CLEAR OUT MUCH COLDER THAN THIS). CLOUDS COULD
LIMIT DAYTIME WARMING...AND ONGOING FORECAST OF TEENS-LOW 20S FOR
HIGHS MAY BE OPTIMISTIC. REGARDING PRECIP CHANCES...MANY OF THE
PERIODS IN THE EXTENDED HAVE SLIGHT CHANCE-CHANCE POPS...AND I DIDNT
SEE THE NEED TO REMOVE THESE BASED ON THE ACTIVE PATTERN ALOFT...AND
LINGERING BAROCLINIC ZONE ACROSS EASTERN COLORADO. BEST CHANCE FOR
MEASURABLE SNOW IN THESE PERIODS DOES APPEAR TO BE SAT-SAT NIGHT
WHEN A SLIGHTLY STRONGER SHORTWAVE TROUGH MOVES OUT OF THE SW US
ACROSS THE SOUTHERN PLAINS. THERE IS LITTLE IN THE WAY OF MOISTURE
RETURN/MOISTURE ADVECTION...SO ANY SNOWFALL WE SEE THROUGH THESE
PERIODS SHOULD BE ON THE LIGHT SIDE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1044 AM MST TUE FEB 25 2014
A STATIONARY BOUNDARY TO THE WEST OF THE TRI STATE AREA WILL
CONTINUE TO TO BRING OVERCAST CONDITIONS TO THE TRI STATE AREA. A
COLD FRONT WILL MOVE THROUGH THE HIGH PLAINS ABOUT 0Z...WHICH WILL
BRING SOME CHANCES FOR LIGHT SNOW SHOWERS TO BOTH TERMINALS. SOME
GUIDANCE HAS VISIBILITIES IN THE SNOW SHOWERS REDUCED INTO THE IFR
CATEGORY...BUT WAS NOT CONFIDENT ENOUGH AT THIS POINT TO DROP
VISIBILITIES QUITE YET IN THIS FORECAST.
SNOW SHOULD TAPER OFF AFTER 6Z...AND A HIGH PRESSURE WILL MOVE
INTO THE AREA TO PROVIDE VFR CONDITIONS AND DECREASING CLOUD COVER
FOR THE REST OF THE TAF PERIOD AFTER 10Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...ALW/JSL
LONG TERM...DR
AVIATION...MK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
157 PM MST TUE FEB 25 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 113 PM MST TUE FEB 25 2014
MAIN FOCUS IN THE SHORT TERM WAS TEMPERATURES TODAY THROUGH
TOMORROW AND PRECIPITATION THIS AFTERNOON AND OVERNIGHT. HIGH
TEMPERATURES THIS AFTERNOON WERE ADJUSTED SINCE SOME LOCATIONS
REACHED THEIR HIGHS AROUND 18/19Z. AFTER 18Z COLDER AIR MOVED INTO
NORTHERN LOCATIONS WHERE TEMPERATURES HAVE REMAINED FAIRLY
STAGNANT OR INCREASED BY A DEGREE OR TWO. PORTIONS OF NORTHWEST
KANSAS AND EASTERN COLORADO ALONG AND SOUTH OF I-70 HAVE SEEN
TEMPERATURES IN THE UPPER TEENS TO MID 20S...BUT THIS APPEARS TO
BE THE PEAK OF TODAY`S HIGH TEMPERATURES AS THE COLDER AIR BEGINS
TO MOVE IN. SNOW HAS DEVELOPED OVER SOUTHWEST NEBRASKA AND IS
MOVING INTO NORTHWEST KANSAS ASSOCIATED WITH A FAIRLY STRONG AREA
OF FRONTOGENESIS. AS THE SHORTWAVE TROUGH IN MONTANA CONTINUES TO
PUSH SOUTHEAST AND THE STRONG AREA OF FRONTOGENESIS MOVES
SOUTHEAST AND THEN SOUTH...SNOWFALL WILL CONTINUE THROUGH THE
EVENING OVER MOST OF THE TRI-STATE REGION. THIS WILL BE A QUICK
MOVING WAVE AND THE GFS...NAM...AND RAP ALL SHOW PRECIPITATION OUT
OF THE FORECAST AREA BY 06Z. SINCE THE SYSTEM MOVES QUICKLY...SNOW
ACCUMULATIONS WILL ONLY BE AROUND HALF AN INCH SOUTH AND EAST TO 2
INCHES NORTH AND NORTHWEST. CLOUD COVER WILL STICK AROUND A LITTLE
AFTER 06Z...WITH MOST OF THE CWA BEING CLEAR BY 15Z. LOWS TONIGHT
WILL DROP DOWN INTO THE SINGLE DIGITS AS HIGH PRESSURE SETTLES
INTO THE CWA. NORTHERN AREAS WILL SEE LOWS AROUND 1 DEGREE ABOVE
ZERO TO NEAR ZERO WHILE AREAS FURTHER SOUTH AND WEST WILL SEE LOWS
AROUND 5 TO 10 ABOVE ZERO.
AS SURFACE HIGH PRESSURE SLIDES EAST-SOUTHEAST...ANOTHER SHORTWAVE
TROUGH WILL MOVE THROUGH. NO PRECIPITATION IS EXPECTED WITH THE
NEXT TROUGH SINCE DRIER AIR MOVES IN SO HAVE KEPT THE FORECAST DRY
FOR TOMORROW. TEMPERATURES WILL BE DIVIDED WITH HIGHS OVER THE
NORTHERN HALF OF THE TRI-STATE REGION IN THE UPPER 30S TO NEAR 40
AND THE SOUTHERN HALF/SOUTH-SOUTHWEST PORTION OF THE TRI-STATE
REGION IN THE LOW TO MID 40S. MODELS MAY HAVE BEEN PICKING UP ON
THE SNOW COVER IN THE NORTHERN AREA OF THE CWA WHICH IS WHY THE
TEMPERATURES THERE ARE A BIT LOWER. USED A COMBINATION OF CONSALL
AND SREF FOR TOMORROW`S TEMPERATURES TO TREND THEM DOWNWARD IN THE
SOUTHERN PORTIONS OF THE CWA SINCE THEY SEEMED TO BE TOO HIGH TO
ACCOUNT FOR ANY SNOWFALL THOSE AREAS MIGHT RECEIVE TONIGHT. WEST
TO SOUTHWEST WINDS TOMORROW COULD ALSO BECOME BREEZY AROUND 18Z AS
THE SHORTWAVE TROUGH PASSES THROUGH AND DAYTIME MIXING INCREASES...BUT ONLY
HAVE SUSTAINED WINDS AROUND 10 TO 20 MPH WITH GUSTS AROUND 25 TO
30 MPH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 224 AM MST TUE FEB 25 2014
WEDNESDAY NIGHT-THURSDAY...PROGRESSIVE SHORTWAVE RIDGE SHOULD HELP
KEEP DRY CONDITIONS IN PLACE THROUGH THESE PERIODS...WITH A SLIGHT
MODERATION OF THE AIR MASS OVER OUR CWA AS STATIONARY FRONT ALONG
FRONT RANGE LIFTS EAST WITH LEE TROUGH DEVELOPMENT. HIGH TEMPS
THURSDAY SHOULD BE NEAR NORMAL FOR WESTERN LOCATIONS (MID 40S TO
NEAR 50F)...WITH COOLER TEMPS IN THE MID/UPPER 30S FURTHER
NORTHEAST.
THURSDAY NIGHT-FRIDAY...NEXT IN A SERIES OF QUICK MOVING SHORTWAVE
TROUGHS WILL MOVE ACROSS THE REGION WITH ARCTIC AIR MASS DROPPING
BACK OVER WESTERN KS. BEST CHANCE FOR MEASURABLE SNOW APPEARS TO BE
LATE THURSDAY NIGHT THROUGH FRIDAY MORNING...WHEN MODELS ARE
ADVERTISING BETTER LARGE SCALE ASCENT. TIMING OF COLD FRONT IS A
LITTLE SLOWER WITH MAIN CAA FRIDAY AFTERNOON...WHICH MAY RESULT IN
QUITE A GRADIENT FROM THE NORTH-SOUTH OVER OUR CWA (LIKELY FALLING
TEMPS ACROSS THE NORTH).
FRIDAY NIGHT-TUESDAY...DESPITE DIFFERENCES IN THE LARGE SALE PATTERN
THROUGH THE EXTENDED PERIODS...MODELS HAVE COME INTO BETTER
AGREEMENT ON STUBBORN ARCTIC AIR MASS REMAINING IN PLACE OVER OUR
CWA...WITH ECMWF NOW TRENDING EVEN COLDER THAN THE LAST 3 RUNS OF
THE GFS. REGARDING LARGE SCALE PATTERN...ECMWF SHOWS MORE OF A
QUASI-ZONAL PATTERN WITH LOWER HEIGHTS SHIFTED SOUTH...WHILE GFS
SHOWS MORE OF A SPLIT FLOW PATTERN WITH THE NORTHERN STREAM HOLDING
MORE INFLUENCE OVER OUR CWA. EITHER SOLUTION FAVORS REINFORCING SHOTS
OF COLD ARCTIC AND AND PROLONGED BELOW NORMAL TEMPERATURES THROUGH AT
LEAST EARLY NEXT WEEK...ALONG WITH A SERIES OF QUICK MOVING
SHORTWAVES PASSING THROUGH THE REGION.
I TRENDED HIGH/LOW TEMPS DOWN TO ACCOUNT FOR THE COLDER PATTERN
CURRENT MODEL RUNS ARE ZEROING IN ON. EXPECTED CLOUD COVER
COMPLICATING HIGHS/LOWS...AND THERE ARE STILL DIFFERENCES BETWEEN
MODELS ON MAGNITUDE OF COOLING...SO I DID NOT FAVOR THE COLDEST
GUIDANCE DURING THIS UPDATE. THE TYPE OF AIR MASS CURRENTLY
ADVERTISED BY EVEN THE "WARMER" GFS WOULD SUPPORT OVERNIGHT LOWS IN
THE SINGLE DIGITS BELOW ZERO OVER PARTS OF OUR CWA DESPITE CLOUD
COVER (AND IF WE CLEAR OUT MUCH COLDER THAN THIS). CLOUDS COULD
LIMIT DAYTIME WARMING...AND ONGOING FORECAST OF TEENS-LOW 20S FOR
HIGHS MAY BE OPTIMISTIC. REGARDING PRECIP CHANCES...MANY OF THE
PERIODS IN THE EXTENDED HAVE SLIGHT CHANCE-CHANCE POPS...AND I DIDNT
SEE THE NEED TO REMOVE THESE BASED ON THE ACTIVE PATTERN ALOFT...AND
LINGERING BAROCLINIC ZONE ACROSS EASTERN COLORADO. BEST CHANCE FOR
MEASURABLE SNOW IN THESE PERIODS DOES APPEAR TO BE SAT-SAT NIGHT
WHEN A SLIGHTLY STRONGER SHORTWAVE TROUGH MOVES OUT OF THE SW US
ACROSS THE SOUTHERN PLAINS. THERE IS LITTLE IN THE WAY OF MOISTURE
RETURN/MOISTURE ADVECTION...SO ANY SNOWFALL WE SEE THROUGH THESE
PERIODS SHOULD BE ON THE LIGHT SIDE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1044 AM MST TUE FEB 25 2014
A STATIONARY BOUNDARY TO THE WEST OF THE TRI STATE AREA WILL
CONTINUE TO TO BRING OVERCAST CONDITIONS TO THE TRI STATE AREA. A
COLD FRONT WILL MOVE THROUGH THE HIGH PLAINS ABOUT 0Z...WHICH WILL
BRING SOME CHANCES FOR LIGHT SNOW SHOWERS TO BOTH TERMINALS. SOME
GUIDANCE HAS VISIBILITIES IN THE SNOW SHOWERS REDUCED INTO THE IFR
CATEGORY...BUT WAS NOT CONFIDENT ENOUGH AT THIS POINT TO DROP
VISIBILITIES QUITE YET IN THIS FORECAST.
SNOW SHOULD TAPER OFF AFTER 6Z...AND A HIGH PRESSURE WILL MOVE
INTO THE AREA TO PROVIDE VFR CONDITIONS AND DECREASING CLOUD COVER
FOR THE REST OF THE TAF PERIOD AFTER 10Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...ALW/JSL
LONG TERM...DR
AVIATION...MK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
224 AM MST TUE FEB 25 2014
.UPDATE...
ISSUED AT 742 PM MST MON FEB 24 2014
JUST ISSUED AN UPDATE TO LOWER MINS WITH SOME LOCATIONS ALREADY
GETTING CLOSE TO THE FORECAST. COLD ADVECTION MORE AGGRESSIVE THAN WHAT
THE CURRENT MODEL OUTPUT IS SAYING. USING CURRENT READINGS AND THE
LATEST HRRR TO MAKE THE ADJUSTMENT.
UPDATE ISSUED AT 556 PM MST MON FEB 24 2014
JUST COMPLETED AN UPDATE. MAIN CHANGE WAS THE WINDS. COLD FRONT
GOING THROUGH THE AREA AT THIS TIME WITH STRONG 3 HOUR PRESSURE
RISES AND TIGHT GRADIENT BEHIND IT. SO WINDS WERE INCREASED INTO
THE BREEZY TO WINDY CATEGORY. BY MID EVENING THE WINDS SHOULD
DECREASE WITH LIGHTER WINDS AFTER MIDNIGHT. MINOR ADJUSTMENT WAS
ALSO MADE TO THE SKY COVER TO INCREASE IT A LITTLE FASTER THAN
WHAT THE GRIDS DEPICTED.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 215 PM MST MON FEB 24 2014
MAIN FOCUS FOR THE SHORT TERM TODAY IS THE TEMPERATURES AND
PRECIPITATION CHANCES OVERNIGHT AND TOMORROW. TEMPERATURES TODAY
HAVE RISEN INTO THE MID 30S OVER THE NORTHEAST PORTIONS OF THE CWA
WHILE FURTHER WEST TEMPERATURES HAVE RISEN INTO THE LOW 60S IN
FLAGLER COLORADO ASSOCIATED WITH A WARM FRONT IN EASTERN COLORADO. THE
NORTHEAST PORTION OF THE CWA WILL REMAIN ON THE COOL SIDE WITH
HIGHS IN THE LOW 20S WHILE THE WEST/SOUTHWEST PORTIONS OF THE CWA
COOL DOWN SIGNIFICANTLY FROM TODAY TO TOMORROW WITH HIGHS
STRUGGLING TO REACH 30 AS A BACK DOOR COLD FRONT MOVES THROUGH
OVERNIGHT. BEHIND THE COLD FRONT...CLOUD COVER WILL INCREASE AND
THERE WILL BE A CHANCE FOR SNOW FLURRIES MOVING IN FROM THE
NORTHEAST. FOR TEMPERATURES AND PRECIPITATION...WENT WITH A BLEND
OF NAM...SREF...AND HRRR. BUFKIT SOUNDINGS BECOME SATURATED
SLIGHTLY ABOVE THE SURFACE AND BECOME DRIER TOWARDS THE SURFACE.
SINCE THE TEMPERATURE PROFILE IS BELOW ZERO AND THE COLUMN IS
FAIRLY SATURATED...CHANGED PRECIPITATION TYPE TO FLURRIES FROM
FREEZING FOG...FROM THE PREVIOUS FORECAST...SINCE THIS SEEMS MORE
LIKELY. FLURRIES SHOULD TAPER OFF AROUND 12Z AS SURFACE HIGH
PRESSURE SLIDES INTO THE CWA.
THE PERIOD OF NO PRECIPITATION TOMORROW MORNING WILL BE RATHER
SHORT-LIVED AS THE NEXT COLD FRONT AND SHORT WAVE TROUGH MOVE
INTO THE CWA. 700MB FRONTOGENESIS SHOWS A DECENT AREA OF LIFT
TRAVERSING THE NORTHERN AND WESTERN PORTIONS OF THE CWA. INCLUDED
CHANCE POPS FOR SNOW STARTING AT 17Z IN EXTREME NORTHERN PORTIONS
OF THE CWA FROM NORTHERN YUMA COUNTY EAST TO NORTHERN RED WILLOW
COUNTY. AS THE AREA OF FRONTOGENESIS MOVES FROM NORTHEAST TO THE
SOUTH-SOUTHWEST...THE CHANCE OF SNOW WILL CONTINUE INTO TUESDAY
NIGHT. ACCUMULATIONS WILL BE AROUND A TENTH OF INCH SOUTH OF
HIGHWAY 36 TO AN INCH OVER AREAS NORTH OF HIGHWAY 36.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 224 AM MST TUE FEB 25 2014
THE ANTICIPATED PROLONGED PERIOD OF BELOW NORMAL TEMPERATURES IS
STILL ON TRACK FOR THIS WEEKEND INTO NEXT WEEK. UNFORTUNATELY...
MODEL DISAGREEMENT HAS INCREASED FOR THE 00Z SUITE OF MODEL GUIDANCE
SO CONFIDENCE IN TIMING OF PRECIPITATION CHANCES...TO WHAT EXTENT
THE TEMPERATURES WILL PLUNGE AND WHEN...IF AT ALL...A WARMING TREND
WILL BEGIN.
THERE WILL BE AT LEAST TWO CHANCES FOR PRECIPITATION IN THE EXTENDED
FORECAST PERIOD. THESE CHANCES COME AS TWO UPPER LEVEL DISTURBANCES
MOVE ACROSS THE HIGH PLAINS. THE FIRST DISTURBANCE PASSES THROUGH
FRIDAY INTO FRIDAY NIGHT. IT STILL APPEARS AS THOUGH THE MAIN LIFT
AND FORCING WITH THIS SYSTEM REMAINS TO THE SOUTH. HOWEVER...WITH A
STALLED FRONTAL BOUNDARY LINGERING SOMEWHERE ACROSS EAST COLORADO
AND WEST KANSAS...WOULD NOT BE SURPRISED IF THE LIFT ALONG THE FRONT
ALLOWED FOR SLIGHTLY HIGHER CHANCES OF PRECIPITATION. THE QUESTION
REMAINS OF WHERE EXACTLY THIS FRONTAL BOUNDARY WILL BE LOCATED.
THE SECOND UPPER LEVEL DISTURBANCE PASSES THROUGH SATURDAY INTO
SUNDAY. THE OVERALL SOLUTIONS FOR THIS SYSTEM HAVE CHANGED AND NOW
PROJECT A STRONG 500 MB TROUGH MOVING ONTO THE CALIFORNIA COAST
BEFORE WEAKENING AS IT CROSSES THE ROCKIES. THEN...THE WEAKER 500 MB
TROUGH BECOMES ENGULFED IN ANOTHER STRONGER 500 MB COMING SOUTHEAST
FROM CANADA AND EVENTUALLY MOVES THROUGH THE HIGH PLAINS AS A WEAKER
OPEN WAVE. WHILE PRECIPITATION CHANCES ARE STILL DECENT...THERE ARE
SOME CONCERNS THAT THIS SYSTEM COULD BYPASS THE REGION COMPLETELY.
MODEL DISAGREEMENT BECOMES A MUCH LARGER PROBLEM FROM SUNDAY NIGHT
ONWARDS. THE EUROPEAN BRINGS A RETURN TO ZONAL FLOW ACROSS THE
UNITED STATES. THIS TYPE OF PATTERN IS FAVORABLE FOR SOUTHWEST FLOW
AND WARMER TEMPERATURES TO RETURN. THE GFS KEEPS A LARGER UPPER
LEVEL TROUGH OVER THE PLAINS WITH ANOTHER STRONG ARCTIC HIGH MOVING
SOUTH...REINFORCING THE COLDER AIR. HAVE SIDED WITH THE GFS FOR THIS
RUN AS THE EUROPEAN HAS MADE A DRASTIC CHANGE FROM THE 00Z RUN
YESTERDAY. THEREFORE...KEPT THE COLDER AIR IN THE TRI-STATE AREA
WITH SLIGHT CHANCES FOR PRECIP AS SUGGESTED BY THE CR INITIALIZATION
PROCEDURE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1043 PM MST MON FEB 24 2014
EARLY IN THE PERIOD...KGLD WILL START OUT AT MVFR AND BECOME VFR
BY 12Z. THEN BOTH KGLD AND KMCK STAY VFR UNTIL EARLY AFTERNOON
WHEN MVFR CONDITIONS WILL DEVELOP AT KMCK. THOSE MVFR CONDITIONS
REMAIN UNTIL 02Z WHEN THE SNOW ENDS. AT KGLD...MVFR BEGINS NEAR
00Z AND WILL LAST TO ALMOST 06Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...ALW/JSL
LONG TERM...RRH
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1047 PM MST MON FEB 24 2014
.UPDATE...
ISSUED AT 742 PM MST MON FEB 24 2014
JUST ISSUED AN UPDATE TO LOWER MINS WITH SOME LOCATIONS ALREADY
GETTING CLOSE TO THE FORECAST. COLD ADVECTION MORE AGGRESSIVE THAN WHAT
THE CURRENT MODEL OUTPUT IS SAYING. USING CURRENT READINGS AND THE
LATEST HRRR TO MAKE THE ADJUSTMENT.
UPDATE ISSUED AT 556 PM MST MON FEB 24 2014
JUST COMPLETED AN UPDATE. MAIN CHANGE WAS THE WINDS. COLD FRONT
GOING THROUGH THE AREA AT THIS TIME WITH STRONG 3 HOUR PRESSURE
RISES AND TIGHT GRADIENT BEHIND IT. SO WINDS WERE INCREASED INTO
THE BREEZY TO WINDY CATEGORY. BY MID EVENING THE WINDS SHOULD
DECREASE WITH LIGHTER WINDS AFTER MIDNIGHT. MINOR ADJUSTMENT WAS
ALSO MADE TO THE SKY COVER TO INCREASE IT A LITTLE FASTER THAN
WHAT THE GRIDS DEPICTED.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 215 PM MST MON FEB 24 2014
MAIN FOCUS FOR THE SHORT TERM TODAY IS THE TEMPERATURES AND
PRECIPITATION CHANCES OVERNIGHT AND TOMORROW. TEMPERATURES TODAY
HAVE RISEN INTO THE MID 30S OVER THE NORTHEAST PORTIONS OF THE CWA
WHILE FURTHER WEST TEMPERATURES HAVE RISEN INTO THE LOW 60S IN
FLAGLER COLORADO ASSOCIATED WITH A WARM FRONT IN EASTERN COLORADO. THE
NORTHEAST PORTION OF THE CWA WILL REMAIN ON THE COOL SIDE WITH
HIGHS IN THE LOW 20S WHILE THE WEST/SOUTHWEST PORTIONS OF THE CWA
COOL DOWN SIGNIFICANTLY FROM TODAY TO TOMORROW WITH HIGHS
STRUGGLING TO REACH 30 AS A BACK DOOR COLD FRONT MOVES THROUGH
OVERNIGHT. BEHIND THE COLD FRONT...CLOUD COVER WILL INCREASE AND
THERE WILL BE A CHANCE FOR SNOW FLURRIES MOVING IN FROM THE
NORTHEAST. FOR TEMPERATURES AND PRECIPITATION...WENT WITH A BLEND
OF NAM...SREF...AND HRRR. BUFKIT SOUNDINGS BECOME SATURATED
SLIGHTLY ABOVE THE SURFACE AND BECOME DRIER TOWARDS THE SURFACE.
SINCE THE TEMPERATURE PROFILE IS BELOW ZERO AND THE COLUMN IS
FAIRLY SATURATED...CHANGED PRECIPITATION TYPE TO FLURRIES FROM
FREEZING FOG...FROM THE PREVIOUS FORECAST...SINCE THIS SEEMS MORE
LIKELY. FLURRIES SHOULD TAPER OFF AROUND 12Z AS SURFACE HIGH
PRESSURE SLIDES INTO THE CWA.
THE PERIOD OF NO PRECIPITATION TOMORROW MORNING WILL BE RATHER
SHORT-LIVED AS THE NEXT COLD FRONT AND SHORT WAVE TROUGH MOVE
INTO THE CWA. 700MB FRONTOGENESIS SHOWS A DECENT AREA OF LIFT
TRAVERSING THE NORTHERN AND WESTERN PORTIONS OF THE CWA. INCLUDED
CHANCE POPS FOR SNOW STARTING AT 17Z IN EXTREME NORTHERN PORTIONS
OF THE CWA FROM NORTHERN YUMA COUNTY EAST TO NORTHERN RED WILLOW
COUNTY. AS THE AREA OF FRONTOGENESIS MOVES FROM NORTHEAST TO THE
SOUTH-SOUTHWEST...THE CHANCE OF SNOW WILL CONTINUE INTO TUESDAY
NIGHT. ACCUMULATIONS WILL BE AROUND A TENTH OF INCH SOUTH OF
HIGHWAY 36 TO AN INCH OVER AREAS NORTH OF HIGHWAY 36.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 305 AM MST MON FEB 24 2014
TUESDAY EVENING AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE AREA.
AHEAD OF THE TROUGH AXIS THE RIGHT ENTRANCE OF THE 500-300 MB JET
STREAK AND 700-300MB FRONTOGENESIS WILL MOVE OVER THE AREA. HAVE
NOTICED THE FRONTOGENESIS HAS STRENGTHENED IN THE LATEST MODEL RUNS
GIVING ADDED CONFIDENCE THAT SNOWFALL WILL DEVELOP. SOUNDINGS
ACROSS THE AREA CONTINUE TO SHOW THE DENDRITIC LAYER ONLY A FEW
THOUSAND FEET OFF THE GROUND. WITH A DEEPLY SATURATED ENVIRONMENT
AND THE DENDRITIC ZONE NEAR THE SURFACE...CONTINUE TO THINK THE
LARGE SCALE LIFT AHEAD OF THE TROUGH WILL ALLOW SNOWFALL TO
DEVELOP. DUE TO THE LOW DEW POINTS IN THE TEENS AM THINKING THE
SNOW WILL BE FAIRLY DRY. DUE TO THE QUICK PASSAGE OF THE TROUGH AM
THINKING SNOW ACCUMULATIONS WILL BE FAIRLY SMALL. AFTER MIDNIGHT
THE TROUGH WILL BE SOUTHEAST OF THE AREA. BEHIND THE TROUGH SKIES
WILL CLEAR AND WINDS WILL BECOME LIGHT...ALLOWING TEMPERATURES TO
FALL NEAR THE DEW POINT.
WEDNESDAY AND WEDNESDAY NIGHT A WARM FRONT WILL MOVE THROUGH THE
AREA DURING THE MORNING ALLOWING TEMPERATURES WARM TO NEAR
NORMAL. OVERNIGHT A COLD FRONT WILL MOVE INTO THE NORTHEAST PART OF
THE AREA...COOLING TEMPERATURES TO AROUND 10 DEGREES BEHIND IT.
THURSDAY THROUGH MONDAY WILL BE DOMINATED BY CHANCES FOR SNOW AS
SEVERAL UPPER LEVEL SHORT WAVE TROUGHS MOVE ACROSS THE AREA. THE
FIRST TROUGH WILL MOVE THROUGH THURSDAY NIGHT...WITH THE MAJORITY OF
THE LIFT FROM THE TROUGH REMAINING SOUTH OF THE AREA...HOWEVER
MODELS SHOW A LARGE PLUME OF 1000-500MB MOISTURE MOVING SOUTHEAST
OVER THE AREA AS THE SMALLER SCALE TROUGH MOVES THROUGH. FRIDAY
THERE MAY BE SOME LINGERING SNOW IN THE MORNING AS THE TROUGH MOVES
OUT OF THE AREA. FRIDAY NIGHT THROUGH THE WEEKEND THE LONG WAVE
TROUGH OVER THE NORTHERN PART OF THE COUNTRY CONTINUES TO DIRECT
1000-500MB MOISTURE OVER THE AREA...ALLOWING CHANCES FOR SNOW TO
CONTINUE THROUGH THE WEEKEND AS ANOTHER STRONGER TROUGH MOVES IN
FROM THE WEST. THIS STRONGER TROUGH WILL MOVE OVER THE AREA
SUNDAY. BY MONDAY THE TROUGH WILL BE EAST OF THE AREA CAUSING
CHANCES FOR SNOW TO COME TO AN END.
TEMPERATURES FOR THE PERIOD WILL BE NEAR TO BELOW NORMAL. THURSDAY
AND FRIDAY THE COLD FRONT WILL WOBBLE EAST TO WEST ACROSS THE AREA.
FRIDAY NIGHT THE FRONT WILL BE PUSHED EAST AS THE LONG WAVE TROUGH
OVER THE NORTHERN PLAINS MOVES SOUTHWARD. BEHIND THE FRONT MUCH
COOLER AIR WILL MOVE INTO THE AREA...WITH TEMPERATURES 10-20 DEGREES
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1043 PM MST MON FEB 24 2014
EARLY IN THE PERIOD...KGLD WILL START OUT AT MVFR AND BECOME VFR
BY 12Z. THEN BOTH KGLD AND KMCK STAY VFR UNTIL EARLY AFTERNOON
WHEN MVFR CONDITIONS WILL DEVELOP AT KMCK. THOSE MVFR CONDITIONS
REMAIN UNTIL 02Z WHEN THE SNOW ENDS. AT KGLD...MVFR BEGINS NEAR
00Z AND WILL LAST TO ALMOST 06Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...ALW/JSL
LONG TERM...JTL
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
212 PM EST TUE FEB 25 2014
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE TRACKS ACROSS THE MID ATLANTIC THIS
AFTERNOON. HIGH PRESSURE BRIEFLY BUILDS INTO THE AREA THIS
EVENING AHEAD OF ANOTHER QUICK MOVING TROUGH...WHICH TRACKS ACROSS
THE REGION WEDNESDAY MORNING. HIGH PRESSURE RETURNS WEDNESDAY
NIGHT AND THURSDAY. A STRONG COLD FRONT DROPS THROUGH THE REGION
THURSDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A MID-LEVEL TROUGH WILL MOVE ACROSS THE NORTHERN MID ATLANTIC
THIS AFTN. LATEST RUC SHOWS A COUPLE OF VORTICITY MAXES...DECENT
LIFT AND LO LVL MOISTURE...WILL SWING FM THE OH VALLEY EWRD ACRS
NRN VA/MD/DE THIS AFTN. BASED ON THIS SCENARIO...HAVE UPDATED TO A
SLGT CHC OF SNOW ACRS THE NRN THIRD OF THE AREA...GENERALLY ALNG
AND N OF A FARMVILLE...TO RICHMOND...TO MELFA LINE. NO
ACCUMULATION IS EXPECTED. THIS SLGT CHC WILL END FM W TO E FM ARND
MIDDAY THRU THE AFTN. WILL CONTINUE WITH A SLGT CHC OF -RA OVER
SE PORTIONS. CLOUD COVER WILL LIMIT HIGH TEMPERATURES...WITH LOW-
LEVEL THICKNESSES SUPPORTING UPPER 30S TO AROUND 40 NE...TO THE
UPPER 40S TO AROUND 50 SW.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
THE MID/UPPER LEVEL FLOW PATTERN REMAINS ZONAL TONIGHT INTO
WEDNESDAY. ANOTHER QUICK MOVING SHORTWAVE TROUGH RACES ACROSS THE
MID ATLANTIC REGION LATE TONIGHT INTO WEDNESDAY MORNING...AFTER HIGH
PRESSURE BRIEFLY RETURNS THIS EVENING. PARTIAL CLEARING THIS EVENING
WILL ALLOW LOWS TO DROP INTO THE MID 20S N...TO LOW 30S SE. CLOUDS
QUICKLY INCREASE AGAIN AFTER MIDNIGHT ALLOWING TEMPERATURES TO
BECOME STEADY.
THIS TROUGH IS A LITTLE MORE VIGOROUS AND DIGS SOMEWHAT FARTHER S.
STILL THE PATTERN IS VERY PROGRESSIVE AND LIMITED WITH RESPECT TO
MOISTURE...SO NOT MUCH MORE THAN A ~3HR WINDOW FOR PRECIP IS
EXPECTED. LOW-LEVEL THICKNESSES WILL BE RATHER COLD...SO MAINLY -SN
IS EXPECTED FROM THE SW PIEDMONT TO THE EASTERN SHORE...WITH A MIX
OF -RA/SN IN THE TIDEWATER AND NE NC...AND MAINLY -RA FOR THE
IMMEDIATE ATLANTIC COAST. ANY ACCUMULATION (GENERALLY 0.5IN OR
LESS) WILL BE CONFINED FROM THE NW PIEDMONT COUNTIES TO THE LOWER MD
EASTERN SHORE WHERE SURFACE TEMPERATURES WILL BE THE COLDEST. DRYING
QUICKLY OVERSPREADS THE AREA FROM WEST TO EAST WEDNESDAY AFTERNOON.
HIGHS SHOULD RANGE FROM THE MID 30S OVER THE LOWER MD EASTERN
SHORE...TO THE MID 40S FROM THE RIC METRO S AND W.
DRY AND BREEZY CONDITIONS DEVELOP THURSDAY AFTER A CHILLY MORNING.
HIGHS SHOULD RISE INTO THE MID 40S N...TO LOW 50S S...AFTER MORNING
LOWS IN THE MID TEENS TO LOW 20S. A GUSTY WSW WIND OF 15-20
MPH...WITH GUSTS TO 25 MPH IS EXPECTED DURING THE AFTERNOON.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
25/00Z ECMWF ALONG WITH THE 25/00Z AND 06Z GFS EACH BRING MOST OF
THE AKQ CWA INTO THE WARM SECTOR NEXT MONDAY. THIS WILL HAVE A
SIGNIFICANT IMPACT ON TEMPERATURE (POTENTIALLY MUCH WARMER) AND
PRECIP-TYPE I.E. A WINTRY MIX VERSUS ALL RAIN. CONTINUITY WILL BE
MAINTAINED AT THIS TIME (COOLER SOLUTION)...BUT IT IS WORTHWHILE TO
MENTION THAT CONFIDENCE IS LOW WITH RESPECT TO THE LATTER PORTION
OF THE EXTENDED PERIOD.
PREVIOUS DISCUSSION...
COLDER WITH BELOW NORMAL TEMPS. A SPLIT FLOW WILL LEAD TO QUICK
SYSTM MOVEMENTS AND PERIODIC PCPN CHCS THRU PRD. LEANED TOWARD THE
ECMWF WITH RESPECT TO SFC FEATURES.
CANADIAN HIGH PRESSURE KEEPS IT DRY BUT COLD FRIDAY. LOWS THURS
NIGHT IN THE L-M20S XCPT A FEW UPR TEENS NRMLY COLDER SPOTS. HIGHS
FRI M30S-L40S. NEXT IN A SERIES OF SRN STREAM S/W`S PROGGED TO TRACK
ACROSS THE SOUTHERN MID ATLNTC REGION FRI NIGHT AND SAT. LATEST MODEL
GUIDANCE WANTS TO SHEAR THE PCPN OUT AS IT CROSSES THE MTS FRI NIGHT
WHILE TRACKING AN AREA OF MSTR FROM SRN VA ACROSS THE CAROLINAS LATE
FRI NITE AND SAT MORN. UPSHOT HERE WILL BE YET ANTHR SYSTM WITH LGT
AMOUNTS OF QPF. P-TYPE ISSUES ARISE GIVEN SFC TMPS AOB FREEZING AND
CRITICAL THICKNESSES. WILL CARRY LOW CHC POPS FOR SNOW NWRN HALF OF
FA...A BUFFER ZONE OF SNOW/SLEET DOWN TO VA/NC BORDER WITH A RAIN
SLEET MIX ACROSS NC LATE FRI NITE. LOWS M20S-L30S. CHC LIQUID POPS
ACROSS SERN SCTNS OF FA WITH A BUFFER ZONE OF MIXED RAIN/SNOW FRTHR
NW SAT MORNING. PCPN ENDS MOST AREAS ARND NOON XCPT SOME LINGERING
RAIN CHCS AT THE COAST SAT AFTRN. HIGHS IN THE 40S.
ANTHR CANADIAN HIGH PRESSURE BUILDS INTO THE AREA SAT NIGHT THROUGH
SUNDAY NITE. DRY AND COLD WITH LOWS SAT NITE UPR TEENS-M20S. HIGHS
SUN M-U30S. LOWS SUN NIGHT IN THE 20S.
MODELS INDCTG ANTHR COMPLICATED SYSTM POISED TO MAKE A BEELINE FOR
THE MID ATLNTC RGN MONDAY. HIGH PRS TO THE NORTH ALLOWS FOR A WEDGE
TO SET UP AHEAD OF A MOISTURE LADEN SYSTM DVLPNG ACROSS THE DEEP
SOUTH. THE LOW PROGGED TO LIFT NORTH ACROSS THE RGN LATE MONDAY
ALONG WITH A COLD FRONTAL PASSAGE. MOISTURE PROGGED TO RIDE UP OVER
THE WEDGE PRODUCING A VARIETY OF WX ACROSS THE RGN SUN NITE AND MON
MORN WITH PCPN BCMG RAIN OVR ERN HALF OF FA MON. TO ERLY TO GET
SPECIFIC...BUT THIS SYSTM DOES BEAR WATCHING FOR THE PTNTL OF A
WINTER MIX OF PCPN SUNDAY NIGHT THROUGH MONDAY MORN. LOWS SUN NITE
25-30. HIGHS MON IN THE 30S AND 40S.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
AN UPPER LEVEL DISTURBANCE PASSING ACROSS NORTHERN VA HAS HELPED
TO THICKEN/LOWER CLOUD DECK ACROSS THE AREA AND GENERATE A BAND OF
LIGHT TO MODERATE SNOW ACROSS THE LOWER MD EASTERN SHORE. RADAR
TRENDS INDICATE THAT THE BAND WILL ONLY AFFECT KSBY THROUGH 20Z.
VIS SATELLITE SHOWS CLEARING BEHIND THE WAVE...SO EXPECT CEILINGS
ACROSS THE AREA TO LIFT/CLEAR BY THIS EVENING.
LOW PRESSURE DEVELOPS OFF THE SOUTHEAST COAST TUESDAY NIGHT INTO
WEDNESDAY MORNING...LIFTING OFFSHORE OF THE MID-ATLANTIC COAST
WEDNESDAY. THERE REMAINS THE POTENTIAL FOR A QUICK SHOT OF WINTRY
PRECIP OVER THE REGION LATE TUES NIGHT INTO EARLY WEDS MORNING.
ACCUMULATING SNOW IS EXPECT GENERALLY NORTH OF KRIC...INCLUDING
KSBY. ELSEWHERE...LIGHT RAIN WILL TRANSITION TO SNOW EARLY WEDS
MORNING. IFR CIGS/VSBYS APPEAR POSSIBLE ATTM EARLY WEDS MORNING AT
ALL TAF SITES. GUSTY NW WINDS ARE ALSO EXPECTED...ESPECIALLY NEAR
THE COAST. HIGH PRESSURE RETURNS WEDS AFTERNOON INTO THURSDAY
BEFORE A FAST MOVING CLIPPER COLD FRONT CROSSES THE REGION THURS.
&&
.MARINE...
HIGH PRESSURE BUILDS OVER THE WATERS TODAY...RESULTING IN SUB-SCA
CONDITIONS. SUB-SCA CONDITIONS CONTINUE INTO WEDS AS A COLD FRONT
APPROACHES FROM THE WEST. COLD FRONT WILL CROSS THE WATERS EARLY
WEDS AFTERNOON AS LOW PRESSURE LIFTS NEWD OFF THE SE COAST.
STRENGTHENING PRESSURE GRADIENT BTWN LOW PRESSURE OFF THE COAST AND
HIGH PRESSURE IN THE MIDWEST WILL COMBINE WITH CAA FOR POSSIBLE SCA
CONDITIONS WEDS AFTERNOON INTO WEDS EVENING. LOW-LEVEL WINDS LOOK
MARGINAL...BUT ANTICIPATE CAA TO BE STRONG ENOUGH TO PRODUCE SCA.
WILL HOLD OFF ON HEADLINES AS ITS LATE 3RD-EARLY 4TH PERIOD AND
CONDITIONS REMAIN MARGINAL. LOW PRESSURE LIFTS WELL OFFSHORE WEDS
NIGHT AS HIGH PRESSURE BUILDS IN FROM THE WEST. FLOW RETURNS TO THE
WSW THURS AS THE NEXT FRONT APPROACHES FROM THE WEST. FRONT WILL
CROSS THE WATERS LATE THURS. SCA CONDITIONS APPEAR LIKELY BEFORE THE
FRONT LATE WEDS MORNING AS THE GRADIENT STRENGTHENS...AND AFTER THE
FRONT AS CAA PRODUCES A STRONG NLY SURGE. HIGH PRESSURE QUICKLY
BUILDS OVER THE WATERS LATE THURS NIGHT...ENDING SCA CONDITIONS.
HIGH PRESSURE WILL REMAIN WEDGED OVER THE WATERS THROUGH THE
WEEKEND.
&&
.FIRE WEATHER...
PRECIPITATION HAS AVERAGED BELOW NORMAL DURING THE PAST WEEK.
ADDITIONALLY MINIMUM RH VALUES RANGED FROM 20-25% FROM THE EASTERN
VA PIEDMONT TO THE LOWER MD EASTERN SHORE SATURDAY AND SUNDAY...AND
FELL TO 15-20% MONDAY. THE ONLY EXCEPTIONS HAVE BEEN FAR SE VA AND
NE NC EAST OF THE CHOWAN RIVER. THIS HAS ALLOWED FINE FUELS TO DRY.
RAIN AND/OR SNOW IS POSSIBLE LATE TUESDAY NIGHT THROUGH WEDNESDAY
MORNING...WITH A LIGHT ACCUMULATION OF SNOW POSSIBLE FROM THE
NORTHERN NECK TO THE EASTERN SHORE. HOWEVER...PRECIPITATION AMOUNTS
WILL GENERALLY BE LESS THAN A TENTH OF AN INCH. DRY AIR QUICKLY
RETURNS WEDNESDAY AFTERNOON. BY THURSDAY AFTERNOON...MINIMUM RH
VALUES OF 15-25% ARE POSSIBLE ALONG WITH A SOUTHWEST WIND AROUND 15
MPH...WITH GUSTS TO 25 MPH AHEAD OF A COLD FRONT. THE NET RESULT IS
THE POTENTIAL FOR ENHANCED FIRE DANGER THURSDAY AFTERNOON. THE
PRIMARY QUESTION WILL BE WHETHER OR NOT THE PRESENCE OF DRY FINE
FUELS CAN OFFSET THE LIMITING FACTORS OF MOIST SOIL AND MOIST LARGER
FUELS. ADDITIONALLY...ENHANCED FIRE DANGER WILL BE ALL BUT
ELIMINATED ACROSS NE PORTIONS IF A LIGHT SNOW ACCUMULATION OCCURS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...AJZ/TMG
SHORT TERM...AJZ
LONG TERM...AJZ/MPR
AVIATION...SAM/DAP
MARINE...SAM
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
410 PM EST TUE FEB 25 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 400 PM EST TUE FEB 25 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A FAMILIAR PATTERN
FEATURING A DEEP UPR TROF OVER ERN NAMERICA DOWNSTREAM OF A RDG
ALONG THE W COAST. SHRTWV EMBEDDED IN THE NW FLOW IS STREAKING SEWD
THRU ONTARIO JUST N OF LK SUP. COLD FNT ASSOCIATED WITH THIS
DISTURBANCE HAS PASSED THRU THE CWA...AND H85 TEMPS AS LO AS -25C TO
-28C ARE PUSHING INTO UPR MI IN THE LLVL W FLOW. ALTHOUGH THERE IS A
GOOD DEAL OF ICE ON LK SUP...AREAS OF OPEN WATER OVER THE FAR WRN LK
AND OVER THE SCENTRAL E OF THE KEWEENAW HAVE ALLOWED A GOOD DEAL OF
LK CLD/SOME -SHSN TO FORM IN THE LLVL CAD. THE LK CLDS/SHSN APPEAR
TO BE MOST WDSPRD OVER THE NE HALF OF THE AREA CLOSER TO THE SHRTWV
PASSING THRU ONTARIO/ACCOMANPANYING DYNAMIC SUPPORT AND DEEPER MSTR.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE LK EFFECT CLD/SHSN
TRENDS AND TEMPS/NEED FOR WIND CHILL HEADLINES.
LATE THIS AFTN/TNGT...AS THE H925 FLOW VEERS MORE TO THE NW THRU 00Z
IN THE WAKE OF SHRTWV PASSING BY TO THE N...EXPECT LK EFFECT
CLDS/SHSN TO SPREAD FARTHER TO THE S AND INLAND IN THE PRESENCE OF
LENGTHENING DAYTIME HEATING DESPITE DNVA/DEEP LYR QVECTOR DVGC IN
THE WAKE OF THE SHRTWV PASSAGE. H85 THERMAL TROF WITH TEMPS DOWN TO
-28/-29C IS FCST TO SHIFT THRU THE CWA BTWN 06Z-12Z AS THE LLVL FLOW
BACKS TO THE W BTWN SFC HI PRES SINKING TOWARD THE MID MS RIVER
VALLEY AND NEXT VIGOROUS SHRTWV DROPPING SEWD THRU SCENTRAL CANADA.
WITH A PERIOD OF LARGER SCALE QVECTOR DVGC...EXPECT CLRG OVER THE
INTERIOR...ALLOWING SFC TEMPS TO FALL WELL BLO ZERO AND INTO THE
TEENS BLO ZERO AT SOME PLACES UNDER DRY AIRMASS WITH PWAT UNDER 0.10
INCH. ALTHOUGH THERE ARE QUESTIONS AS TO WHETHER SFC WINDS WL
CONSISTENTLY SATISFY THE 10 MPH SPEED THRESHOLD FOR A WIND CHILL
ADVY...PLAN TO ISSUE AN ADVY FOR THE COLDER NW HALF OF THE CWA WITH
FAIRLY SHARP PRES GRADIENT/H925 WINDS IN THE 20-30KT RANGE UNDER H85
THERMAL TROF ENHANCING MIXING. LK EFFECT CLDS/-SHSN WL SHIFT FM THE
NW WIND SN BELTS BACK INTO AREAS IMPACTED BY W WINDS LATE TNGT.
ABSENCE OF DGZ WITHIN VERY COLD AIRMASS AND ICE COVER WL LIMIT SN
ACCUMS.
WED...AREA OF DEEP LYR QVECTOR CNVGC IN ADVANCE OF SHRTWV/SFC LO
DIGGING SEWD THRU NW ONTARIO WL OVERSPREAD UPR MI NW-SE BY EARLY
AFTN. IN THE ABSENCE OF ANY SGNFT MSTR INFLOW...SUSPECT DRYNESS OF
ANTECEDENT AIRMASS WL BE A SGNFT IMPEDIMENT TO OUTBRREAK OF PCPN. AS
THE FLOW SHIFTS TO THE SW...THERE IS POTENTIAL FOR SOME LK
MOISTENING/ENHANCEMENT OFF OF LK MI. BUT EXTENSIVE/GROWING ICE COVER
OVER THE N HALF OF LK MI WL TEND TO MITIGATE THIS IMPACT. TENDED
TOWARD THE HIER CHC/LIKELY POPS OVER THE NE HALF OF THE CWA TOWARD
SHARPER ISENTROPIC ASCENT ON THE 270K SFC /NEAR H7/ AND ALSO LATE IN
THE DAY OVER THE W WITH EXPECTED ARRIVAL OF ENHANCED LLVL CNVGC
ASSOCIATED WITH COLD FNT ATTENDANT TO CLIPPER LO REACHING NE LK SUP
BY 00Z THU.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 409 PM EST TUE FEB 25 2014
ANOTHER WAVE FROM THE TROUGH OVER EASTERN CANADA WILL BE QUICKLY
DIVING SOUTHEAST ACROSS THE UPPER GREAT LAKES REGION ON WEDNESDAY
EVENING. A 1000MB LOW WILL BE DROPPING SOUTHEAST ACROSS
NORTHEASTERN LAKE SUPERIOR AND THEN INTENSIFYING TO 995MB AS IT
MOVES OVER THE GEORGIAN BAY BY 12Z THURSDAY. MODELS CONTINUE TO BE
FAIRLY CONSISTENT WITH THE TRACK/INTENSITY/TIMING OF THE
LOW...WHICH LENDS CONFIDENCE TO THE FORECAST...ESPECIALLY WITH THE
WINDS. THE COMBINATION OF COLD AIR ADVECTION AND STRONG PRESSURE
RISES (10MB/6HR) BEHIND THE LOW BETWEEN 06Z AND 15Z THURSDAY SHOULD
LEAD TO A PERIOD OF GUSTY WINDS ACROSS MUCH OF UPPER MICHIGAN. THE
WORST CONDITIONS WILL BE IN THE EXPOSED AREAS NEAR LAKE SUPERIOR
FROM ONTONAGON EASTWARD. OVER THE KEWEENAW AND THEN AREAS FROM
MARQUETTE EASTWARD...MODELS ARE SHOWING 925MB WINDS IN THE 35-45KT
RANGE WITH THE HIGHEST VALUES FROM THE TIP OF THE KEWEENAW TO ALGER
COUNTY. WITH THE PASSAGE OF THE COLD FRONT ON WEDNESDAY
EVENING...THINK THERE WILL BE A PERIOD OF LIGHT SNOW BUT
ACCUMULATIONS SHOULD BE LESS THAN .5IN IN MOST AREAS. ALTHOUGH THIS
WON/T AMOUNT TO MUCH...IT WILL LEAD TO SOME BLOWING/DRIFTING SNOW.
THE WORST CONDITIONS WILL AGAIN BE OVER THE KEWEENAW...WHICH
ALREADY HAS LARGE MOUNDS/DRIFTS ON THE EDGES OF ROADWAYS THAT SHOULD
EASILY REDEVELOP OVER THE ROADS WITH THE STRONG WINDS AND A LITTLE
BIT OF SNOW. FARTHER EAST...THERE HAS BEEN SOME LIGHT LAKE EFFECT
AND WITH ICE REDEVELOPING EAST OF THE KEWEENAW THERE SHOULD BE AN
OPEN/FLAT AREA FOR THE SNOW TO MOVE ACROSS AND IMPACT ALGER COUNTY.
WITH M-28 EXPOSED TO THE LAKE EAST AND BETTER ICE COVERAGE EAST OF
SHOT POINT...THINK THERE WILL BE A GOOD POTENTIAL FOR
BLOWING/DRIFTING SNOW CAUSING ISSUES ON THE ROAD THROUGH MUNISING.
THE COLD AIR RECENTLY HAS LEAD TO ICE SPREADING OVER THE OPEN AREAS
THE DEVELOPED A COUPLE DAYS AGO AND FORTUNATELY...THINK THIS WILL
LIMIT THE AMOUNT OF LAKE EFFECT WITH THE NORTHWEST WINDS BEHIND THE
LOW WED NIGHT INTO THURSDAY. ALSO...WITH A HIGH PRESSURE RIDGE
QUICKLY MOVING IN TO THE U.P. FROM WEST TO EAST THURSDAY MORNING
INTO THURSDAY AFTERNOON...IT SHOULD DO TWO THINGS. BRING DRIER AIR
AND LIMIT THE ANY LAKE EFFECT INTENSITY AND ALSO LEAD TO QUICKLY
WEAKENING WINDS.
WITH THE PRECIPITATION...WIND...AND ALSO COLD
TEMPERATURES...HEADLINES WILL LIKELY BE NEEDED OVER ALL OF UPPER
MICHIGAN WEDNESDAY NIGHT INTO THURSDAY MORNING. WIND CHILL
TEMPERATURES ARE CURRENTLY FORECAST IN THE -25 TO -40 DEGREE RANGE
AND PUTS SOME NORTHERN AREAS ON BORDERLINE WIND CHILL WARNING
CRITERIA. OTHERWISE...THINK THE ENTIRE U.P. WOULD NEED A WIND CHILL
ADVISORY. SECOND...WITH THE REDUCED VISIBILITIES NEAR LAKE SUPERIOR
FROM FALLING/BLOWING/DRIFTING SNOW...WILL LIKELY NEED AT LEAST A
WINTER WEATHER ADVISORY FOR THE KEWEENAW PENINSULA AND ALGER COUNTY.
THE WINDS AND VISIBILITIES WILL LIKELY PRODUCE BRIEF PERIODS OF
BLIZZARD CONDITIONS IN THE KEWEENAW...BUT WITH THE MODELS ONLY
SHOWING A PEAK PERIOD OF 6HRS OF THE WORST WINDS AND IT LARGELY
BEING OVERNIGHT BEFORE QUICKLY DIMINISHING...FEEL IMPACT WON/T
BE AS BAD AS PREVIOUS EVENT AND WON/T ISSUE A BLIZZARD WATCH. WINDS
WILL LIKELY BE WORSE OVER ALGER COUNTY...BUT THERE IS MORE
UNCERTAINTY WITH THE VISIBILITY ASPECT OF THE CRITERIA WITH THE
LIMITED SNOWFALL SINCE THE RA/FZRA FROM LAST THURSDAY NIGHT (ALONG
WITH GENERALLY NEW ICE UPSTREAM ON LAKE SUPERIOR AND LIMITED SNOW
COVER). THUS...THINK ANY BLIZZARD CONDITIONS WOULD BE PATCHY AND
WOULD SUPPORT MORE OF A WINTER WX ADVISORY.
STILL LOOKS TO BE A RECORD BREAKING COLD DAY ON THURSDAY...WITH
MODELS KEEPING MUCH OF THE AREA AROUND OR BELOW FREEZING FOR HIGHS.
THAT SEEMS PRETTY REASONABLE WITH THE POCKET OF COLD 850MB TEMPS
(-30C) DIRECTLY OVER THE AREA. THIS IS SIMILAR TO 850MB TEMPS FROM
JANUARY 27TH AND HIGHS THAT DAY WERE IN THE SINGLE DIGITS BELOW
ZERO OVER THE WEST AND AT OR JUST ABOVE FREEZING OVER THE EAST. AS
MENTIONED YESTERDAY...ALL-TIME COLDEST HIGH TEMP RECORDS FOR FEB
27TH ARE GENERALLY IN THE MID SINGLE DIGITS ABOVE ZERO (WITH AT
LEAST 6 DATING BACK BEFORE 1925). WITH COLD AIR IN PLACE AND A HIGH
PRESSURE RIDGE PRODUCING LIGHT WINDS...EXPECT A VERY COLD NIGHT
THURSDAY NIGHT AND WILL CONTINUE TO GO WITH THE LOW END OF GUIDANCE
WHICH PLACES MUCH OF THE AREA BETWEEN -15 AND -30 BELOW. THIS
ALSO HAS THE POTENTIAL FOR BEING RECORD LOWS AT SEVERAL
LOCATIONS...AS LONG AS THE HIGH CLOUDS DON/T COME IN TOO QUICKLY
FROM THE SOUTHWEST.
THE HIGH PRESSURE RIDGE WILL SLIDE EAST ON FRIDAY AS ANOTHER
SHORTWAVE ROUNDING THE EASTERN CANADA TROUGH APPROACHES. A WEAK
INVERTED TROUGH (FROM A LOW IN THE SOUTHERN PLAINS) WILL SLIDE
ACROSS THE AREA ON FRIDAY EVENING AND BRING THE POTENTIAL FOR LIGHT
SNOW. IT DOES APPEAR TO BE OUT AHEAD OF THE MAIN FORCING FROM THE
SHORTWAVE...SO UPPER LEVEL SUPPORT WILL BE LIMITED AND KEEP SNOW
ACCUMULATIONS GENERALLY UNDER AN INCH. MODELS VARY ON HOW MUCH COLD
AIR SPILLS IN BEHIND THIS TROUGH...BUT IT STILL LOOKS LIKE HIGHS ON
SATURDAY WILL BE WELL BELOW NORMAL AND AT OR JUST ABOVE ZERO. THERE
IS ALSO CONCERN FOR LAKE EFFECT SNOW WITH THE COLD AIR PRESENT...BUT
WOULD EXPECT MUCH OF THE LAKE TO BE FROZEN OVER WITH THE COLD AIR
OVER THE PREVIOUS COUPLE OF DAYS AND LIGHT WINDS THURSDAY NIGHT.
THEREFORE...WILL KEEP POPS FOR SATURDAY IN THE SLIGHT CHANCE AND LOW
END CHANCE CATEGORY FOR LOCATIONS NEAR LAKE SUPERIOR. HIGH PRESSURE
BUILDING IN SATURDAY NIGHT AND REMAINING INTO SUNDAY SHOULD LEAD TO
DRY CONDITIONS.
FOR THE FIRST PART OF NEXT WEEK...THE UPPER TROUGH IN EASTERN
CANADA DOES LOOK TO WEAKEN SOME AND BEGIN TO PULL NORTHEAST TOWARDS
THE END OF THE WORK WEEK. OUR CLOSE PROXIMITY TO THIS TROUGH WILL
KEEP THE MAIN STORM TRACK AND WARMER AIR WELL TO THE SOUTH OF THE
AREA...BUT WE COULD STILL SEE WEAK WAVES SLIDING THROUGH. WOULD
EXPECT LAKE SUPERIOR TO BE NEARLY ICE COVERED...SO WILL LIMIT ANY
MENTION OF LAKE EFFECT POPS TO SLIGHT CHANCES AT MOST. AS FOR
TEMPS...SHOULD SEE A SLOW/GRADUAL WARMING TREND THROUGH THE WORK
WEEK...BUT TEMPS WILL STILL BE WELL BELOW NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1237 PM EST TUE FEB 25 2014
CMX...GUSTY NW FLOW OF VERY COLD AIR WL RESULT IN LIFR CONDITIONS AT
THIS EXPOSED LOCATION THRU THIS EVNG. WITH SOME DECREASE IN WIND/
BLSN TNGT...EXPECT SOME IMPROVEMENT TO IFR CONDITIONS. AS THE FLOW
BACKS FURTHER TO THE SW ON WED AHEAD OF NEXT DISTURBANCE...THERE WL
LIKELY BE A PERIOD OF VFR CONDITIONS ON WED MRNG.
IWD...A WIND VEERING TO THE NW WL ALLOW SOME LK CLDS/SHSN TO BRING
MVFR CONDITIONS TO THIS LOCATION LATER THIS AFTN/THRU THE EVNG.
OTHERWISE...VFR CONDITONS WL PREDOMINATE.
SAW...MARGINAL MVFR TO VFR CIGS WL PREDOMINATE THRU THIS EVNG WITH A
NW FLOW OF VERY COLD AIR. AS THE FLOW BACKS TO THE W AND SW LATER
TNGT INTO WED...VFR WX WL RETURN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 PM EST TUE FEB 25 2014
NW WINDS UP TO 25-30 KTS LATE TODAY UNDER SHARP PRES GRADIENT
BETWEEN SFC HI OVER THE NCENTRAL PLAINS AND LO PRES IN EASTERN
ONTARIO WILL SLOWLY BACK TO THE SW ON WED AS THE HI MOVES INTO THE
MID MS RIVER VALLEY AND ANOTHER LO PRES SYSTEM DIVES SE INTO NW
ONTARIO. THERE MAY BE SOME GALE FORCE GUSTS TO 35 KTS OVER THE W
HALF OF THE LAKE WHERE FUNNELING OF THIS FLOW RESULTS IN SPEED
ENHANCEMENT. ONCE THE LO SHIFTS TO THE E OF THE LAKE ON WED NIGHT
AS THE PRES GRADIENT TIGHTENS AGAIN E OF HI PRES MOVING INTO THE
NORTHERN PLAINS...N GALES UP TO 35-45 KTS WILL DEVELOP OVER THE
ENTIRE LAKE. THE CLOSER APPROACH OF THE HI CENTER AND WEAKER PRES
GRADIENT WILL CAUSE THE GALES TO DIMINISH W TO E ON THU. ISSUED A
GALE WATCH FOR THE ENTIRE LAKE. EXPECT WINDS UNDER 25 KTS THE REST
OF THE FORECAST PERIOD WITH A RELATIVELY WEAK PRES GRADIENT
DOMINATING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY FROM MIDNIGHT EST /11 PM CST/ TONIGHT TO 10
AM EST /9 AM CST/ WEDNESDAY FOR MIZ001>005-009>011-084.
LAKE SUPERIOR...
GALE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY AFTERNOON
FOR LSZ243>245-248>251-264>267.
GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING FOR
LSZ162-240>242-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
400 PM EST TUE FEB 25 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 400 PM EST TUE FEB 25 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A FAMILIAR PATTERN
FEATURING A DEEP UPR TROF OVER ERN NAMERICA DOWNSTREAM OF A RDG
ALONG THE W COAST. SHRTWV EMBEDDED IN THE NW FLOW IS STREAKING SEWD
THRU ONTARIO JUST N OF LK SUP. COLD FNT ASSOCIATED WITH THIS
DISTURBANCE HAS PASSED THRU THE CWA...AND H85 TEMPS AS LO AS -25C TO
-28C ARE PUSHING INTO UPR MI IN THE LLVL W FLOW. ALTHOUGH THERE IS A
GOOD DEAL OF ICE ON LK SUP...AREAS OF OPEN WATER OVER THE FAR WRN LK
AND OVER THE SCENTRAL E OF THE KEWEENAW HAVE ALLOWED A GOOD DEAL OF
LK CLD/SOME -SHSN TO FORM IN THE LLVL CAD. THE LK CLDS/SHSN APPEAR
TO BE MOST WDSPRD OVER THE NE HALF OF THE AREA CLOSER TO THE SHRTWV
PASSING THRU ONTARIO/ACCOMANPANYING DYNAMIC SUPPORT AND DEEPER MSTR.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE LK EFFECT CLD/SHSN
TRENDS AND TEMPS/NEED FOR WIND CHILL HEADLINES.
LATE THIS AFTN/TNGT...AS THE H925 FLOW VEERS MORE TO THE NW THRU 00Z
IN THE WAKE OF SHRTWV PASSING BY TO THE N...EXPECT LK EFFECT
CLDS/SHSN TO SPREAD FARTHER TO THE S AND INLAND IN THE PRESENCE OF
LENGTHENING DAYTIME HEATING DESPITE DNVA/DEEP LYR QVECTOR DVGC IN
THE WAKE OF THE SHRTWV PASSAGE. H85 THERMAL TROF WITH TEMPS DOWN TO
-28/-29C IS FCST TO SHIFT THRU THE CWA BTWN 06Z-12Z AS THE LLVL FLOW
BACKS TO THE W BTWN SFC HI PRES SINKING TOWARD THE MID MS RIVER
VALLEY AND NEXT VIGOROUS SHRTWV DROPPING SEWD THRU SCENTRAL CANADA.
WITH A PERIOD OF LARGER SCALE QVECTOR DVGC...EXPECT CLRG OVER THE
INTERIOR...ALLOWING SFC TEMPS TO FALL WELL BLO ZERO AND INTO THE
TEENS BLO ZERO AT SOME PLACES UNDER DRY AIRMASS WITH PWAT UNDER 0.10
INCH. ALTHOUGH THERE ARE QUESTIONS AS TO WHETHER SFC WINDS WL
CONSISTENTLY SATISFY THE 10 MPH SPEED THRESHOLD FOR A WIND CHILL
ADVY...PLAN TO ISSUE AN ADVY FOR THE COLDER NW HALF OF THE CWA WITH
FAIRLY SHARP PRES GRADIENT/H925 WINDS IN THE 20-30KT RANGE UNDER H85
THERMAL TROF ENHANCING MIXING. LK EFFECT CLDS/-SHSN WL SHIFT FM THE
NW WIND SN BELTS BACK INTO AREAS IMPACTED BY W WINDS LATE TNGT.
ABSENCE OF DGZ WITHIN VERY COLD AIRMASS AND ICE COVER WL LIMIT SN
ACCUMS.
WED...AREA OF DEEP LYR QVECTOR CNVGC IN ADVANCE OF SHRTWV/SFC LO
DIGGING SEWD THRU NW ONTARIO WL OVERSPREAD UPR MI NW-SE BY EARLY
AFTN. IN THE ABSENCE OF ANY SGNFT MSTR INFLOW...SUSPECT DRYNESS OF
ANTECEDENT AIRMASS WL BE A SGNFT IMPEDIMENT TO OUTBRREAK OF PCPN. AS
THE FLOW SHIFTS TO THE SW...THERE IS POTENTIAL FOR SOME LK
MOISTENING/ENHANCEMENT OFF OF LK MI. BUT EXTENSIVE/GROWING ICE COVER
OVER THE N HALF OF LK MI WL TEND TO MITIGATE THIS IMPACT. TENDED
TOWARD THE HIER CHC/LIKELY POPS OVER THE NE HALF OF THE CWA TOWARD
SHARPER ISENTROPIC ASCENT ON THE 270K SFC /NEAR H7/ AND ALSO LATE IN
THE DAY OVER THE W WITH EXPECTED ARRIVAL OF ENHANCED LLVL CNVGC
ASSOCIATED WITH COLD FNT ATTENDANT TO CLIPPER LO REACHING NE LK SUP
BY 00Z THU.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 518 AM EST TUE FEB 25 2014
VERY COLD...LIGHT-MODERATE SNOW...AND VERY STRONG WINDS WILL BE THE
MAIN STORIES FOR THIS LONG TERM SECTION.
MULTIPLE SHORTWAVES SLIDING ACROSS THE AREA IN THE FAST 500MB W-NW
FLOW WILL RESULT IN A MOSTLY CLOUDY SKY FOR MUCH OF THE PERIOD...AND
GENERALLY LIGHT SNOW. SNOW WILL VARY SIGNIFICANTLY MAINLY DUE THE
THE NEARLY FROZEN...OR QUICKLY RE-FREEZING LAKE SUPERIOR.
WILL START OFF WEDNESDAY MORNING UNDER NW FLOW ALOFT...AND A SLIGHT
RIDGE AT THE SFC WITH DIMINISHING CHANCES OF LES. PLENTY OF CLOUDS
WILL REMAIN AS THE NEXT SFC LOW/SHORTWAVE NEAR FROM THE NW. THE
DEEPENING SFC LOW OVER CENTRAL ONTARIO AT 18Z WILL SINK ACROSS THE
KEWEENAW AND E LAKE SUPERIOR BY 00Z THURSDAY. INCREASING SW WINDS OF
10-20KTS AHEAD OF THE LOW WILL QUICKLY SHIFT BACK TO THE NW LATE
WEDNESDAY AFTERNOON INTO THE EARLY EVENING HOURS. THE MAIN 500MB LOW
WILL BE ABLE TO SINK TO NE LAKE SUPERIOR BY 06Z THURSDAY...WITH VERY
LOW 850MB TEMPS OF -30 TO -36C STRETCHING FROM W UPPER MI THROUGH
MUCH OF LAKE HURON. VERY STRONG WINDS WILL ALLOW FOR SIGNIFICANT
BLOWING AND DRIFTING SNOW ACROSS THE KEWEENAW PENINSULA BRIEFLY ON
SW WINDS EARLY WEDNESDAY AFTERNOON...AND THEN ON NW WINDS WEDNESDAY
NIGHT INTO THURSDAY MORNING WITH IMPRESSIVE MOMENTUM TRANSFER VALUES
OF NEAR 33-40KT. WITH THESE KIND OF WINDS WE COULD SEE NEAR BLIZZARD
CONDITIONS...DESPITE NEW SNOW OF GENERALLY 2IN OR LESS OVER THE
KEWEENAW PENINSULA AND E OF MARQUETTE ALONG M-28 THROUGH
MUNISING...AND THEN E TO GRAND MARAIS. LOW WIND CHILLS OF 20 TO NEAR
40 BELOW ZERO WILL BE POSSIBLE AS SFC TEMPS FALL INTO THE TEENS
BELOW ZERO OVER THE W HALF OF UPPER MI.
BITTERLY COLD CONDITIONS WILL CONTINUE THROUGH SUNDAY...WITH RECORD
BREAKING TEMPERATURES POSSIBLE THURSDAY THROUGH FRIDAY MORNING. AS A
RESULT...WILL KEEP THE MAINLY CHANCE POPS OR LESS BEYOND
THURSDAY...DUE TO THE UNKNOWN ICE BREAKAGE FROM THE STRONG WINDS
WEDNESDAY/THURSDAY...AND RE-FREEZING THAT COULD BE POSSIBLE IN THIS
VERY COLD AIRMASS. COLDEST MORNING LOOKS TO BE THURSDAY NIGHT/FRIDAY
MORNING...WITH TEMPS BOTTOMING OUT NEAR 25 BELOW OVER THE INTERIOR W
HALF. HOWEVER...WITH HIGH PRESSURE OVERHEAD...AND WINDS GENERALLY
5KTS OR LESS WIND CHILLS WILL STILL BE COLD BUT NOT QUITE AS DRASTIC.
THERE IS STILL ENOUGH VARIANCE IN THE MODELS FROM THE WEEKEND ON TO
RESULT IN A MORE MEDIUM TO LOWER CONFIDENCE IN THE FCST. WAS A
LITTLE CONCERNED WITH THE 24/18Z RUN OF THE GFS CAME IN WITH A
1020MB SFC LOW OVER THE E HALF OF UPPER MI AT 06Z SATURDAY. THE
25/00Z GFS SHOVED IT FARTHER TO THE S MUCH QUICKER. THEN THE LATEST
ECMWF CAME IN WITH A SOLUTION CLOSER TO THE ORIGINAL/SLOWER 24/18Z
GFS...WITH THE ORIGINAL PLAN WAS TO HAVE THE STRONG SFC HIGH SURGING
IN FROM S CANADA AND THE CENTRAL PLAINS. HAVE KEPT WITH A MODEL
BLEND IN THE ONGOING FCST...BUT AS NOTED CONFIDENCE IS
DIMINISHING...WITH SIGNIFICANT IMPLICATIONS TO SKY
COVER/TEMPS/WINDS/WIND CHILLS/AND WX. AT 12Z 850MB TEMPS OFF THE
ECMWF WENT FROM A CWA AVERAGE -30 TO -24C...WITH THE COLDEST AIR NOW
LIKELY STAYING N ACROSS ONTARIO. WILL KEEP THE MENTION OF COLD
TEMPS/LOW WIND CHILLS IN THE HWO.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1237 PM EST TUE FEB 25 2014
CMX...GUSTY NW FLOW OF VERY COLD AIR WL RESULT IN LIFR CONDITIONS AT
THIS EXPOSED LOCATION THRU THIS EVNG. WITH SOME DECREASE IN WIND/
BLSN TNGT...EXPECT SOME IMPROVEMENT TO IFR CONDITIONS. AS THE FLOW
BACKS FURTHER TO THE SW ON WED AHEAD OF NEXT DISTURBANCE...THERE WL
LIKELY BE A PERIOD OF VFR CONDITIONS ON WED MRNG.
IWD...A WIND VEERING TO THE NW WL ALLOW SOME LK CLDS/SHSN TO BRING
MVFR CONDITIONS TO THIS LOCATION LATER THIS AFTN/THRU THE EVNG.
OTHERWISE...VFR CONDITONS WL PREDOMINATE.
SAW...MARGINAL MVFR TO VFR CIGS WL PREDOMINATE THRU THIS EVNG WITH A
NW FLOW OF VERY COLD AIR. AS THE FLOW BACKS TO THE W AND SW LATER
TNGT INTO WED...VFR WX WL RETURN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 408 AM EST TUE FEB 25 2014
A FEW POCKETS OF FREEZING SPRAY WILL BE POSSIBLE WEDNESDAY INTO
THURSDAY MORNING ACROSS THE OPEN WATERS OF WESTERN LAKE SUPERIOR. A
FEW SOUTHWESTERLY GALE FORCE GUSTS TO 35 KNOTS ARE POSSIBLE AROUND
MID DAY WEDNESDAY ACROSS THE WEST HALF OF LAKE SUPERIOR. BEHIND A
LOW PRESSURE SYSTEM WEDNESDAY NIGHT THROUGH THURSDAY
MORNING...NORTHWESTERLY GALES TO 35 TO 40 KNOTS ARE EXPECTED OVER
MUCH OF LAKE SUPERIOR. A GALE WATCH MAY BE NEEDED FOR WEDNESDAY
NIGHT AND THURSDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY FROM MIDNIGHT EST /11 PM CST/ TONIGHT TO 10
AM EST /9 AM CST/ WEDNESDAY FOR MIZ001>005-009>011-084.
LAKE SUPERIOR...
GALE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY AFTERNOON
FOR LSZ243>245-248>251-264>267.
GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING FOR
LSZ162-240>242-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1159 PM EST MON FEB 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 357 PM EST MON FEB 24 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW PERSISTENT...COLD
NW FLOW DOMINATING THE GREAT LKS BTWN RDG ALONG THE W COAST AND
CLOSED LO OVER QUEBEC/TROF IN ERN NAMERICA. COMBINATION OF SHRTWV
EMBEDDED IN NW FLOW ALF...DEEPER MSTR SHOWN ON THE 12Z INL RAOB...
H85 TEMPS IN THE -18C TO -21C RANGE AND SOME OPEN WATER ON LK SUP
HAS RESULTED IN SOME GENERALLY LGT LES IN AREAS FAVORED BY THE LLVL
WNW FLOW. OVER THE INTERIOR...SOME DIURNAL CU/SC HAVE DVLPD IN
RATHER MOIST AIRMASS WITH INCRSG SUN ANGLE CAUSING SOME LLVL
DESTABILIZATION. BTWN THE SHRTWV MOVING THRU THE UPR LKS EARLY THIS
AFTN AND ANOTHER STRONGER DISTURBANCE STRETCHING FM NEAR LK WINNIPEG
INTO THE NRN PLAINS/ACCOMPANYING -SN MOVING THRU THE DAKOTAS...
SHRTWV RDG/AXIS OF DRIER MID LVL AIR IS BRINGING GENERALLY MOSUNNY
WX TO MUCH OF MN EXCEPT THE ARROWHEAD. YET ANOTHER SHRTWV IS
DROPPING SWD FM THE NW TERRITORIES OF CANADA INTO NRN SASKATCHEWAN/
MANITOBA.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE LES TRENDS AND TEMPS
ASSOCIATED WITH THE STEADY PARADE OF DISTURBANCES EMBEDDED IN NW
FLOW ALF.
TNGT...WITH APRCH AND PASSAGE OF SHRTWV RDG LATER THIS AFTN AND THIS
EVNG/ACCOMPANYING DEEP LYR QVECTOR DVGC AND SUBSIDENCE...EXPECT
LINGERING LES TO AT LEAST DIMINISH IN INTENSITY/COVERAGE FOR A TIME.
BUT AS SHRTWV NOW MOVING INTO THE NRN PLAINS SHIFTS TO THE SE
TNGT...AREA OF ACCOMPANYING DEEP LYR QVECTOR CNVGC/MORE MSTR AND SFC
COLD FNT ARE FCST TO IMPACT THE AREA MAINLY AFT MIDNGT. ALTHOUGH ALL
MODELS SHOW THE ACCOMPANYING SYNOPTIC SCALE PCPN PASSING TO THE S OF
THE CWA CLOSER TO CORE OF UPR DVGC ON CYC SIDE OF H3 JET MAX...
EXPECT AN INCRS IN LES COVERAGE NEAR LK SUP OVERNGT. TEMPS COULD
FALL OFF QUICKLY THIS EVNG OVER AT LEAST THE INTERIOR NEAR THE WI
BORDER AS AXIS OF DRIER AIR AT LEAST BRIEFLY MOVES OVHD BEFORE
THICKER CLDS ASSOCIATED WITH DISTURBANCE NEAR LK WINNIPEG ARRIVE
LATER.
TUE...WHILE THERE MAY BE SOME MID LVL DRYING/SUBSIDENCE EARLY ON TUE
WITH A PERIOD OF QVECTOR DVGC FOLLOWING THE DEPARTING DISTURBANCE...
SHRTWV NOW DROPPING S INTO SASKATCHEWAN/MANITOBA IS FCST TO BRING A
RETRUN OF MORE DYNAMIC SUPPORT/SOME DEEPER MSTR BY THE AFTN...
ESPECIALLY OVER THE NE HALF OF THE CWA. SO EXPECT INCRSG LES POPS
AGAIN IN THE WNW WIND SN BELTS NEAR THE LK. GIVEN H85 TEMPS FALLING
AOB -25C BY LATE IN THE DAY CAUSING THE NEAR ELIMINATION OF THE DGZ
AS WELL AS CONSIDERABLE ICE COVER OVER LK SUP...EXPECT SN AMOUNTS TO
BE RELATIVELY LIGHT. TUE WL BE ANOTHER UNSEASONABLY COLD DAY. TENDED
TOWARD THE LO END OF GUIDANCE FOR MAX TEMPS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 406 PM EST MON FEB 24 2014
THE FIRST IN A SERIES OF UPPER LEVEL DISTURBANCES THAT WILL BRING
COLDER AIR TO THE AREA WILL BE SWEEPING ACROSS UPPER MICHIGAN
TUESDAY AFTERNOON AND EARLY TUESDAY EVENING. THIS SHORTWAVE WILL
USHER IN SLIGHTLY COLDER 850MB TEMPS ON TUESDAY NIGHT (-28C) AND
WITH WINDS OUT OF THE NORTHWEST...WOULD EXPECT AT LEAST A BRIEF
PERIOD OF LIGHT TO MODERATE LAKE EFFECT SNOW IN THE NORTHWEST WINDS
SNOW BELTS DURING THE EVENING. BUT MODELS ARE SHOWING DRY AIR ABOVE
850MB MOVING IN QUICKLY AFTER 06Z WEDNESDAY...SO THAT SHOULD CUT OUT
THE INTENSITY HEADING INTO THE OVERNIGHT HOURS. GETTING A GOOD
HANDLE ON ICE COVER OVER THE WESTERN LAKE TODAY...WITH OPEN WATER
GENERALLY NORTHWEST OF A LINE FROM THE APOSTLE ISLANDS TO TERRACE
BAY ONTARIO. THAT GAP OF 30-40MI IS PLENTY TO SUPPORT LAKE EFFECT
CLOUDS AND SNOW...WHICH HAS BEEN SEEN THIS MORNING OVER WESTERN
UPPER MICHIGAN. THEREFORE...WILL CONTINUE TO SHOW LIKELY POPS IN
THE NORTHWEST WIND AREAS OVER THE WEST IN THE EVENING AND DIMINISH
SLIGHTLY OVERNIGHT WITH THE INCREASING DRY AIR AND BACKING WINDS
ASSOCIATED WITH A WEAK HIGH PRESSURE RIDGE. THE EAST IS A LITTLE
MORE COMPLICATED...SINCE THE ONLY POCKET OF OPEN WATER IS THE AREA
TO THE EAST OF THE KEWEENAW PENINSULA AND SOUTH TO MARQUETTE. WITH
THE NORTHWEST WINDS...THAT WOULD SUPPORT THE HIGHEST POPS/AMOUNTS
OVER ALGER COUNTY AND THINK FARTHER EAST INTO LUCE COUNTY (EVEN THE
EASTERN THIRD OF ALGER COUNTY) WOULD SEE LESS ACCUMULATION AND MORE
SCATTERED SNOW SHOWERS WITH THE AMOUNT OF ICE THE BANDS ORIGINATING
NORTHEAST OF ISLE ROYALE WOULD HAVE TO PASS OVER.
THE WEAK HIGH PRESSURE WILL SLIDE ACROSS THE U.P. LATE TUESDAY
NIGHT AND WEDNESDAY MORNING...AS THE NEXT SHORTWAVE AND LOW
PRESSURE SYSTEM DIVE SOUTHEAST OUT OF WESTERN ONTARIO WEDNESDAY
AFTERNOON AND ACROSS LAKE SUPERIOR AT 998MB ON WEDNESDAY EVENING.
THE BEST SNOW ASSOCIATED WITH THIS LOW AND SHORTWAVE WILL LIKELY BE
NEAR THE SURFACE LOW WITH THE LOWER LEVEL DRY AIR BEING PULL
NORTHEAST ACROSS UPPER MICHIGAN. ANY SYNOPTIC SNOW SHOULD BE LIGHT
AND ONLY CREATE A LIGHT DUSTING...MAINLY NEAR LAKE SUPERIOR. BUT
BEHIND THE LOW...EXPECT ANOTHER OPPORTUNITY FOR LAKE EFFECT SNOW IN
NORTHWEST TO NORTH-NORTHWEST WIND AREAS. THE 925MB WINDS WILL BE
FAIRLY STRONG (35KTS) BEHIND THE FRONT AND WILL LIKELY LIMIT THE
RESIDENCE TIME OVER THE 30-40MI STRETCH OF OPEN WATER. WOULD EXPECT
THIS TO LIMIT SNOWFALL AMOUNTS EVEN THOUGH DELTA-T VALUES ARE
NEARING 30-32 AND INVERSION HEIGHTS ARE BETWEEN 10-14KFT. ALTHOUGH
SNOW AMOUNTS MAY NOT BE TOO SIGNIFICANT...THINK THE PERIOD OF VERY
GUSTY NORTHWEST WINDS ON THE BACK SIDE OF THE LOW (GUSTS NEAR LAKE
SUPERIOR OF 30-40KTS NEAR LAKE SUPERIOR FROM ONTONAGON TO WHITEFISH
POINT) WILL CREATE A SIGNIFICANT CONCERN FOR WIDESPREAD BLOWING AND
DRIFTING SNOW. HAVE TRENDED WINDS UP 5-10KTS FOR THIS PERIOD WITH
THE CONSISTENCY IN THE MODELS ON THIS WINDY IDEA. WILL ALSO ADD A
MENTION OF THE POTENTIAL FOR CONSIDERABLE BLOWING AND DRIFTING SNOW
NEAR LAKE SUPERIOR IN THE HWO THAT WILL DEVELOP WEDNESDAY NIGHT
AND CONTINUE INTO THURSDAY MORNING. ADD FINE FLAKE SNOW FALLING WITH
THE BLOWING SNOW SHOULD EASILY CREATE VISIBILITIES OF 1/2MI OR
LESS IN THE KEWEENAW. THE GUSTY WINDS WILL COMBINE WITH TEMPERATURES
BELOW ZERO ON THURSDAY MORNING TO ALSO CREATE A CONCERN FOR WIND
CHILL HEADLINES FOR A GOOD PORTION OF UPPER MICHIGAN. CURRENT
FORECAST HAS WIND CHILL VALUES OF -25 TO -35 DEGREES AND WITH THE
POTENTIAL FOR BLOWING SNOW IT COULD EVENTUALLY BE TIED TOGETHER WITH
A WINTER WX ADVISORY.
ONCE AGAIN...A HIGH PRESSURE RIDGE (FROM A HIGH MOVING INTO THE
UPPER MISSISSIPPI VALLEY) WILL QUICKLY MOVE OVER UPPER MICHIGAN ON
THURSDAY AFTERNOON INTO THURSDAY NIGHT. THIS SHOULD RAPIDLY
DIMINISH WINDS OVER THE AREA DURING THE AFTERNOON. MODELS CONTINUE
TO SHOW HIGHS ONLY REACHING AROUND 0 DEGREES ON THURSDAY...WHICH
WOULD PUT SEVERAL COLD HIGH TEMPERATURE RECORDS IN JEOPARDY SINCE
MOST ARE IN THE MID SINGLE DIGITS ABOVE ZERO. FOR THE LONG PERIOD OF
RECORD SITES...MOST OF THOSE RECORDS DATE BACK TO THE LATE 1800S AND
EARLY 1900S. WOULD EXPECT SKIES TO CLEAR OUT AWAY FROM ANY LAKE
EFFECT NEAR LAKE SUPERIOR THURSDAY AFTERNOON AND CONTINUE INTO
THURSDAY NIGHT. THINK THIS WILL LEAD TO A VERY COLD NIGHT ACROSS THE
AREA AND WILL CONTINUE TO SHOW LOWS IN THE 10S TO MID 20S BELOW ZERO
(COLDEST INTERIOR COLD SPOTS).
ANOTHER SHORTWAVE WILL ROUND THE EASTERN CANADA UPPER TROUGH ON
FRIDAY AND DIVE SOUTHEAST ACROSS UPPER MICHIGAN FRIDAY NIGHT. THE
COLD AIR ASSOCIATED WITH THIS WAVE WILL LEAD TO ANOTHER DAY OF
HIGHS ABOUT 30 DEGREES BELOW NORMAL ON SATURDAY. LAKE EFFECT
POTENTIAL CONTINUES FRIDAY NIGHT INTO SATURDAY...BUT WORRIED THAT
THE VERY COLD TEMPS AND LIGHT WINDS ON THURSDAY NIGHT INTO FRIDAY
WILL LEAD TO A FAST ICE UP OF THE OPEN AREAS AND CUT OFF LAKE
EFFECT. WILL GO WITH SLIGHT AND LOW CHANCE POPS AT THIS POINT DUE TO
THE UNCERTAINTY. EXTENDED MODELS ARE SHOWING A TREND TOWARDS MORE
ZONAL FLOW AND GRADUALLY WARMING TEMPERATURES SUNDAY AND HEADING
INTO NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1158 PM EST MON FEB 24 2014
A COUPLE OF DISTURBANCES PASSING THRU THE AREA...ONE OVERNIGHT AND
THE SECOND THIS AFTN...WILL BRING AN UPTICK IN LAKE EFFECT SHSN AND
BLSN AT KIWD/KCMX...THOUGH THERE IS SOME CONCERN WITH HOW FAST ICE
MAY BE EXPANDING INTO THE OPEN WATER AREAS THAT DEVELOPED OVER WRN
LAKE SUPERIOR DUE TO STRONG WINDS OVER THE LAST SEVERAL DAYS.
ASSUMING ENOUGH OPEN WATER REMAINS...IFR CONDITIONS SHOULD DEVELOP
AT KCMX OVERNIGHT WITH IFR CONDITIONS MOST LIKELY TODAY IN
ASSOCIATION WITH SECOND DISTURBANCE. WHILE THERE MAY BE SOME
-SHSN/MVFR CONDITIONS LATER IN THE NIGHT AT KIWD...IFR CONDITIONS
WILL MORE LIKELY DEVELOP THIS AFTN AS WINDS VEER TOWARD THE NW WITH
SECOND DISTURBANCE. AT KSAW...DOWNSLOPE WESTERLY WINDS WILL WORK TO
MAINTAIN VFR CONDITIONS INTO THE MORNING. DAYTIME HEATING WILL THEN
LIKELY RESULT IN AN MVFR CIG DEVELOPING WITH THE ARRIVAL OF MORE
UNSTABLE AIR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 PM EST MON FEB 24 2014
WEST TO NORTHWEST WINDS OF 15-25KTS WILL CONTINUE TONIGHT THROUGH
TUESDAY NIGHT...BUT THEN BACK ON WEDNESDAY MORNING AHEAD OF AN
APPROACHING LOW PRESSURE SYSTEM. A TIGHTENING GRADIENT AHEAD OF
THAT LOW COULD LEAD TO A FEW GALE FORCE GUSTS TO 35KTS AROUND
MID-DAY WEDNESDAY. THEN AS THE LOW DROPS SOUTHEAST ACROSS EASTERN
LAKE SUPERIOR ON WEDNESDAY EVENING...EXPECT A RAPID SWITCH AND
INCREASE IN THE WINDS FROM THE NORTHWEST AND CURRENT THOUGHT IS
THAT MUCH OF THE LAKE WILL SEE GALE FORCE GUSTS TO 35-40KTS. A HIGH
PRESSURE RIDGE WILL QUICKLY MOVE OVER THE AREA THURSDAY
AFTERNOON/NIGHT AND WEAKEN THE WINDS. ANOTHER TROUGH MOVING THROUGH
ON FRIDAY NIGHT WILL INCREASE WINDS BACK TO 15-25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...SRF
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
559 PM CST WED FEB 26 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 220 PM CST WED FEB 26 2014
MAIN FORECAST CONCERN IN THE SHORT TERM IS STRONG WINDS AND THE
RESULTING BLOWING/DRIFTING SNOW EXPECTED ACROSS THE AREA THROUGH
THIS EVENING. LATEST SURFACE ANALYSIS AND OBS SHOW THE COLD FRONT
MOVING THROUGH THE NORTH HALF OF THE FORECAST AREA AT THE CURRENT
TIME... WITH A NICE WIND SHIFT FROM SOUTHWEST TO NORTHWEST BEHIND
THE FRONT. WE/RE SEEING STRONG SOUTHWEST WINDS... SUSTAINED NEAR
20KT WITH GUSTS TO AROUND 30KT AHEAD OF THE FRONT... AND NORTHWEST
WINDS OF AROUND 25KT WITH GUSTS OF 35KT IMMEDIATELY BEHIND THE
FRONT. HOWEVER... FORECAST SOUNDINGS FROM THE RAP AND NAM CONTINUE
TO SUGGEST THE BEST MIXING WITH POST FRONTAL COLD ADVECTION AND
SUBSIDENCE WILL OCCUR DURING THE EARLY EVENING ACROSS MOST OF THE
AREA... WITH 00-05Z LOOKING LIKE PRIME TIME FOR STRONG WINDS AND
POTENTIAL BLIZZARD CONDITIONS. THE HOPWRF MATCHES UP WITH THIS
TIMING QUITE WELL... AND HAS ENSEMBLE MEAN SUSTAINED WINDS OF AROUND
30 MPH AND GUSTS WELL IN EXCESS OF 40 MPH FOR A PERIOD OF SEVERAL
HOURS. LOCATIONS WHICH WILL SEE THE GREATEST IMPACT STILL LOOK TO BE
THE OPEN AREAS OVER THE WESTERN AND SOUTHERN PART OF THE AREA...
WHERE THE COMBINATION OF DEEP SNOW... STRONG WINDS... AND FAVORABLE
TERRAIN SHOULD LEAD TO WIDESPREAD LOW VISIBILITY AND SIGNIFICANT
DRIFTING SNOW. SOME LIGHT SNOW AND FLURRIES WILL SLIP THROUGH THE
NORTH/NORTHEAST PORTION OF THE AREA THROUGH THIS EVENING... BUT ANY
ACCUMULATION WILL BE VERY MINOR GIVEN THE EXTREMELY LIMITED MOISTURE
AHEAD OF THE SHORTWAVE AND COLD FRONT. THE PRESSURE GRADIENT LOOKS
TO QUICKLY RELAX OVERNIGHT INTO THURSDAY MORNING... SO WE SHOULD SEE
THE BLOWING/DRIFTING SETTLE DOWN FAIRLY QUICKLY AFTER MIDNIGHT. WILL
KEEP THE GOING HEADLINES IN PLACE... AS WELL AS THE TIMING... WHICH
STILL LOOKS TO ENCAPSULATE THE ENTIRETY OF THE EVENT. HOWEVER...
WIND CHILLS WILL BE PLUMMETING OVERNIGHT AS COLDER AIR ARRIVES.
ALTHOUGH WINDS WILL BE DYING OFF... THEY WILL STILL BE SUFFICIENT TO
PRODUCE VERY COLD WIND CHILLS... WHICH WILL PERSIST INTO THE DAY ON
THURSDAY. THE NORTHERN COUNTIES LOOK LIKE THEY WILL SEE WIDESPREAD
WIND CHILLS OF -35 TO -45... WHILE THE CENTRAL AND SOUTHERN PORTION
OF THE AREA WILL MAINLY BE IN THE -25 TO -35 RANGE. SO... ALTHOUGH
THE HEADLINES FOR BLOWING/DRIFTING SNOW WILL END OVERNIGHT... THEY
WILL BE REPLACED BY WIND CHILL HEADLINES THROUGH THURSDAY MORNING.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 220 PM CST WED FEB 26 2014
LONGER TERM TRENDS CONTINUE TO REMAIN COLD. TEMPERATURES ARE
EXPECTED TO REMAIN FAR BELOW NORMAL THROUGH THE ENTIRE PERIOD.
STANDARDIZED ANOMALIES FROM THE NAM AND GEFS CONTINUE TO SHOW H85
TEMPERATURES AROUND 2 TO 3 STANDARD DEVIATIONS BELOW
NORMAL...WHICH SHOULD CONTINUE TO YIELD 30 TO 40 DEGREES BELOW
NORMAL THROUGH MOST OF THE PERIOD. SOME INDICATIONS AT THE END OF
THE PERIOD...INTO NEXT WEEK...THE UPPER FLOW PATTERN MAY FLATTEN A
BIT OVER THE NORTHERN CONUS...ALLOWING SOME MODIFIED PACIFIC TYPE
AIR TO INTRUDE ACROSS THE NORTHERN PLAINS. THAT IS PRETTY FAR IN
THE FUTURE AND THE 12Z ECMWF IS THE MODEL MOST PROMINENT WITH THIS
OVERALL DEVELOPMENT.
A COUPLE OF SNOW CHANCES COME INTO PLAY...NAMELY FRIDAY AND
SATURDAY/SATURDAY NIGHT. MODELS TREND AN INVERTED TROUGH EAST
ACROSS THE CWA ON FRIDAY. BEST FORCING IS FOUND OVER THE SOUTHERN
CWA. WILL CONTINUE TO MENTION LIKELY POPS FOR THE SOUTHERN
THIRD OF THE AREA THEN. WILL HAVE TO MONITOR FOR DEVELOPMENT ON
THE NORTH END OF THE TROUGH AS WELL...BUT CONTINUE CHANCE POPS
THERE. THIS WOULD GENERATE AN INCH OR TWO OF ACCUMULATION TO THE
SOUTH BY FRIDAY EVENING. SHOULD BE A FLUFFY SNOW AND WINDS DO
INCREASE SOME IN THE WAKE OF THE TROUGH. AT THE PRESENT TIME THEY
DO NOT APPEAR TO BE STRONG ENOUGH TO GENERATE SIGNIFICANT
BLOWING/DRIFTING SNOW CONCERNS.
THE NEXT SNOW THREAT ARRIVES FOR SATURDAY AND SATURDAY NIGHT.
MODELS IN SOME DISAGREEMENT AS TO HOW FAR AND SNOW THREAT WOULD
BE AS LARGE COLD ARCTIC HIGH BUILDS SOUTHEAST OVER THE AREA INTO HE
WEEKEND. AT THE MOMENT THE BEST AGREEMENT REMAINS OVER FAR SOUTHERN
MINNESOTA FOR MEASURABLE SNOW AND WILL MENTION LIKELY POPS IN THAT
AREA.
WIND CHILL CONCERNS WILL CONTINUE INTO THE WEEKEND BUT WINDS
SHOULD GRADUALLY DIMINISH AS THE ARCTIC HIGH SETTLES CLOSE TO THE
CWA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 554 PM CST WED FEB 26 2014
HIGHLY VARIABLE CONDITIONS ONGOING AND RANGING FROM VFR TO LIFR
WITH BLSN. AS WINDS CONTINUE TO INCREASE A BIT EARLY THIS
EVENING...THINK A CONTINUATION OF DETERIORATING CONDITIONS WILL
PERSIST...THEN IMPROVE BY MID TO LATE EVENING AS WINDS SUBSIDE.
KMSP...VFR FOR THE MOST PART THROUGH THE PERIOD WITH BRIEF
INSTANCES OF MVFR CONDITIONS WITH BLOWING SNOW THIS EVENING.
NORTHWEST WIND GUSTS TO 35 KT WILL DECREASE THROUGH THE NIGHT AND
BECOME SOUTH LATE IN THE PERIOD.
/OUTLOOK FOR KMSP/
FRI...CHC MVFR WITH -SN. S WIND 5-10 KT BCMG NW.
SAT...VFR. NNW WIND 10 KT.
SUN...VFR. NW WIND 5 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR MNZ047-
048-054>070-073>078-082>085-091>093.
BLIZZARD WARNING UNTIL 3 AM CST THURSDAY FOR MNZ041-042-048-049-
055>059-065>069-073>077-082>085-091>093.
WIND CHILL WARNING FROM 3 AM TO NOON CST THURSDAY FOR MNZ041>045-
049>053.
WINTER WEATHER ADVISORY UNTIL 3 AM CST THURSDAY FOR MNZ043>045-
047-050>054-060>064-070-078.
WI...WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR
WIZ023>028.
WIND CHILL WARNING FROM 3 AM TO NOON CST THURSDAY FOR WIZ014>016.
WINTER WEATHER ADVISORY UNTIL 3 AM CST THURSDAY FOR WIZ014>016-
023>028.
&&
$$
SHORT TERM...TRH
LONG TERM...DWE
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1134 AM CST TUE FEB 25 2014
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 259 AM CST TUE FEB 25 2014
CLOUDS AND OCCASIONAL FLURRIES ARE LINGERING IN THE AREA. SUBJECTIVE
00Z UPPER AIR ANALYSIS INDICATES UPPER-LEVEL SHORTWAVE TROUGH NEAR
THE SD/ND BORDER...WITH 500MB HEIGHT FALLS UP TO 90M AHEAD OF IT IN
EASTERN SD. 08Z WATER VAPOR AND RAP 1.5 PVU PRESSURE INDICATE
STRONG UPPER-LEVEL TROUGH DIGGING THROUGH IA THIS MORNING...WITH
SECONDARY SHORTWAVE UPSTREAM IN NORTHERN MT. STRONGEST UPPER-LEVEL
JET EXTENDED FROM MT THROUGH WESTERN SD INTO EASTERN NEB/IA AND
EASTWARD ACROSS THE MID-ATLANTIC. MUCH COLDER AIR WAS FILTERING
INTO THE PLAINS IN WAKE OF THE TROUGH...WITH 850MB TEMPERATURES -20C
OR COLDER IN ND/MT AND UPPER TEENS BELOW ZERO SPILLING INTO SD.
MAIN FORECAST CONCERN IS POTENTIAL FOR LIGHT SNOW TO CLIP THE
SOUTHWEST CWA TODAY...THEN ONE MORE DAY OF MODERATE TEMPERATURES
BEFORE THE COLD AIR PLUNGES INTO THE PLAINS. WEAK LIFT IN THE
DENDRITIC ZONE WILL EXIT THE AREA BY THIS MORNING...AND FLURRIES
SHOULD END FOR A TIME. SECOND...WEAKER SHORTWAVE WILL SLIDE THROUGH
THE NORTHERN ROCKIES TOWARD WESTERN/CENTRAL NEB TODAY...WITH WEAK
FRONTOGENETIC BAND AROUND 700-650MB SETTING UP FROM WESTERN TO SOUTH
CENTRAL NEB THIS AFTERNOON. SHOULD SEE SNOW WITH THAT BAND...BUT
EASTERN EXTENT IS IN QUESTION AS BETTER SUPPORT REMAINS WEST OF THE
AREA...AND DRIER LOW-LEVEL AIR BELOW THE MORE SATURATED MID-LEVELS
MAY HINDER MEASURABLE SNOW. HAVE CONTINUED TO INDICATE SLIGHT CHANCE
OF SNOW IN SOUTHEAST NEB THIS AFTERNOON...TAPERING AWAY BY THIS
EVENING.
WESTERLY WINDS RETURN TO THE AREA ON WEDNESDAY. WHILE SNOW ON THE
GROUND WILL HINDER TEMPERATURES IN THE NORTHERN CWA...THE COUPLE OF
TENTHS THAT FELL ELSEWHERE ARE NOT LIKELY TO COUNTERACT THE
FAVORABLE MIXING WINDS. HAVE KEPT TEMPS ABOVE GUIDANCE IN THE 30S
ACROSS MOST OF THE AREA...AS THE LAST DAY THAT COULD RISE ABOVE
FREEZING FOR QUITE SOME TIME. REINFORCING COLD AIR ARRIVES ON
WEDNESDAY NIGHT/THURSDAY AS A COLD AND DRY HIGH PRESSURE SLIDES OUT
OF THE DAKOTAS/MN INTO WESTERN IA. MID-LEVEL WARM AIR ADVECTION IS
PROGGED TO DEVELOP ON THE WESTERN SIDE OF THE HIGH ON THURSDAY
NIGHT...BUT GIVEN DRY AIR FEEDING IN FROM THE EAST...BELIEVE PRECIP
WILL BE HELD AT BAY THROUGH 12Z FRIDAY. MODELS HAVE TRENDED IN THAT
DIRECTION AS WELL...WITH ALL SOLUTIONS BUT THE NAM NOW DRY FOR
THURSDAY NIGHT. HAVE REMOVED POPS ACROSS THE AREA.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 259 AM CST TUE FEB 25 2014
ALTHOUGH THERE IS A BRIEF ATTEMPT AT MODERATION ON FRIDAY...PATTERN
TURNS COLDER THROUGH THE WEEKEND/MONDAY...WITH MUCH BELOW
NORMAL TEMPERATURES AND CHANCES OF LIGHT SNOW PERSISTING.
GOOD AGREEMENT BETWEEN 00Z GFS/ECMWF IN A DECENT H7 LOW/TROUGH
MOVING ALONG KS BORDER FRIDAY BRINGING MODEST SNOW CHANCES TO MUCH
OF THE FA...ESPECIALLY CNTRL/SRN ZONES. AFTER THAT THE COLD AIR IS
REINFORCED OVER THE NRN/CENTRAL PLAINS AS SEVERAL LOBES PIVOT AROUND
HUDSON BAY LOW SENDING COLD HIGH PRESSURE SOUTHWARD. MEANWHILE...
THE MID LEVEL FLOW OVER THE PLAINS REMAINS MORE WRLY AND EVEN
SWRLY AT TIMES. THUS PERIODS OF SNOW CHANCES WILL
PERSIST...ALTHOUGH NO MAJOR SYSTEMS WERE CURRENTLY SUGGESTED FOR
FA BY 00Z MODELS. BASED ON 00Z RUNS OF GFS/ECMWF IT DOES APPEAR
SOMEWHAT OF A LULL POSSIBLE FRIDAY NIGHT OVER MUCH OF THE
AREA...SATURDAY ACROSS THE SOUTH AND THEN MOST OF THE REGION BY
MONDAY. PRECIPITATION MENTION DURING THOSE TIMES WAS KEPT MOSTLY
IN THE SLIGHT CHANCE CATEGORY...ALTHOUGH WITH MID LEVEL
TEMPERATURES FAVORABLE FOR ICE CRYSTAL GENERATION IT WOULD NOT
TAKE MUCH TO GENERATE AREAS OF LIGHT SNOW ANY OF THOSE PERIODS IF
MOISTURE IS PRESENT. WITH H85 TEMPERATURES OF -15 TO -25 FORECAST
TO SAG SWD THROUGH FA SAT/SUN...MAX TEMPERATURES MAY REMAIN IN
SINGLE DIGITS MANY AREAS SATURDAY AND POSSIBLY EVEN SUNDAY NRN
ZONES WITH MEX/ECE GUIDANCE POSSIBLY INFLUENCED BY CLIMO WITH
NORMAL HIGHS NOW APPROACHING OR EXCEEDING 40 DEGREES F. TRIMMED
BACK HIGHS A BIT SATURDAY/SUNDAY. LEFT LOWS MOSTLY ALONE FOR
NOW...SINGLE DIGITS EITHER SIDE OF ZERO F...AS CLOUD INFLUENCES
ENOUGH OF A THREAT WITH THE WEST OR POSSIBLY SW MID LEVEL FLOW
RIDING OVER COLD LOW LEVEL FLOW.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1130 AM CST TUE FEB 25 2014
A FEW MVFR CIGS AND VISIBILITIES ARE POSSIBLE AT KLNK INITIALLY AS
A BAND OF SNOW SLIDES SOUTH ACROSS THE TAF SITE. OTHERWISE...KOFK
AND KOMA SHOULD REMAIN VFR THROUGHOUT THE TAF CYCLE. HIGH PRESSURE
WILL BUILD SOUTHEAST ACROSS THE AREA OVERNIGHT. NORTHWEST SFC
WINDS WILL DIMINISH AND SKIES WILL CLEAR. SFC WINDS WILL TURN TO
THE SOUTHWEST LATE WEDNESDAY MORNING AND BECOME GUSTY TO NEAR 20
TO 25 KTS.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MAYES
LONG TERM...CHERMOK
AVIATION...KERN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
523 AM CST TUE FEB 25 2014
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 259 AM CST TUE FEB 25 2014
CLOUDS AND OCCASIONAL FLURRIES ARE LINGERING IN THE AREA. SUBJECTIVE
00Z UPPER AIR ANALYSIS INDICATES UPPER-LEVEL SHORTWAVE TROUGH NEAR
THE SD/ND BORDER...WITH 500MB HEIGHT FALLS UP TO 90M AHEAD OF IT IN
EASTERN SD. 08Z WATER VAPOR AND RAP 1.5 PVU PRESSURE INDICATE
STRONG UPPER-LEVEL TROUGH DIGGING THROUGH IA THIS MORNING...WITH
SECONDARY SHORTWAVE UPSTREAM IN NORTHERN MT. STRONGEST UPPER-LEVEL
JET EXTENDED FROM MT THROUGH WESTERN SD INTO EASTERN NEB/IA AND
EASTWARD ACROSS THE MID-ATLANTIC. MUCH COLDER AIR WAS FILTERING
INTO THE PLAINS IN WAKE OF THE TROUGH...WITH 850MB TEMPERATURES -20C
OR COLDER IN ND/MT AND UPPER TEENS BELOW ZERO SPILLING INTO SD.
MAIN FORECAST CONCERN IS POTENTIAL FOR LIGHT SNOW TO CLIP THE
SOUTHWEST CWA TODAY...THEN ONE MORE DAY OF MODERATE TEMPERATURES
BEFORE THE COLD AIR PLUNGES INTO THE PLAINS. WEAK LIFT IN THE
DENDRITIC ZONE WILL EXIT THE AREA BY THIS MORNING...AND FLURRIES
SHOULD END FOR A TIME. SECOND...WEAKER SHORTWAVE WILL SLIDE THROUGH
THE NORTHERN ROCKIES TOWARD WESTERN/CENTRAL NEB TODAY...WITH WEAK
FRONTOGENETIC BAND AROUND 700-650MB SETTING UP FROM WESTERN TO SOUTH
CENTRAL NEB THIS AFTERNOON. SHOULD SEE SNOW WITH THAT BAND...BUT
EASTERN EXTENT IS IN QUESTION AS BETTER SUPPORT REMAINS WEST OF THE
AREA...AND DRIER LOW-LEVEL AIR BELOW THE MORE SATURATED MID-LEVELS
MAY HINDER MEASURABLE SNOW. HAVE CONTINUED TO INDICATE SLIGHT CHANCE
OF SNOW IN SOUTHEAST NEB THIS AFTERNOON...TAPERING AWAY BY THIS
EVENING.
WESTERLY WINDS RETURN TO THE AREA ON WEDNESDAY. WHILE SNOW ON THE
GROUND WILL HINDER TEMPERATURES IN THE NORTHERN CWA...THE COUPLE OF
TENTHS THAT FELL ELSEWHERE ARE NOT LIKELY TO COUNTERACT THE
FAVORABLE MIXING WINDS. HAVE KEPT TEMPS ABOVE GUIDANCE IN THE 30S
ACROSS MOST OF THE AREA...AS THE LAST DAY THAT COULD RISE ABOVE
FREEZING FOR QUITE SOME TIME. REINFORCING COLD AIR ARRIVES ON
WEDNESDAY NIGHT/THURSDAY AS A COLD AND DRY HIGH PRESSURE SLIDES OUT
OF THE DAKOTAS/MN INTO WESTERN IA. MID-LEVEL WARM AIR ADVECTION IS
PROGGED TO DEVELOP ON THE WESTERN SIDE OF THE HIGH ON THURSDAY
NIGHT...BUT GIVEN DRY AIR FEEDING IN FROM THE EAST...BELIEVE PRECIP
WILL BE HELD AT BAY THROUGH 12Z FRIDAY. MODELS HAVE TRENDED IN THAT
DIRECTION AS WELL...WITH ALL SOLUTIONS BUT THE NAM NOW DRY FOR
THURSDAY NIGHT. HAVE REMOVED POPS ACROSS THE AREA.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 259 AM CST TUE FEB 25 2014
ALTHOUGH THERE IS A BRIEF ATTEMPT AT MODERATION ON FRIDAY...PATTERN
TURNS COLDER THROUGH THE WEEKEND/MONDAY...WITH MUCH BELOW
NORMAL TEMPERATURES AND CHANCES OF LIGHT SNOW PERSISTING.
GOOD AGREEMENT BETWEEN 00Z GFS/ECMWF IN A DECENT H7 LOW/TROUGH
MOVING ALONG KS BORDER FRIDAY BRINGING MODEST SNOW CHANCES TO MUCH
OF THE FA...ESPECIALLY CNTRL/SRN ZONES. AFTER THAT THE COLD AIR IS
REINFORCED OVER THE NRN/CENTRAL PLAINS AS SEVERAL LOBES PIVOT AROUND
HUDSON BAY LOW SENDING COLD HIGH PRESSURE SOUTHWARD. MEANWHILE...
THE MID LEVEL FLOW OVER THE PLAINS REMAINS MORE WRLY AND EVEN
SWRLY AT TIMES. THUS PERIODS OF SNOW CHANCES WILL
PERSIST...ALTHOUGH NO MAJOR SYSTEMS WERE CURRENTLY SUGGESTED FOR
FA BY 00Z MODELS. BASED ON 00Z RUNS OF GFS/ECMWF IT DOES APPEAR
SOMEWHAT OF A LULL POSSIBLE FRIDAY NIGHT OVER MUCH OF THE
AREA...SATURDAY ACROSS THE SOUTH AND THEN MOST OF THE REGION BY
MONDAY. PRECIPITATION MENTION DURING THOSE TIMES WAS KEPT MOSTLY
IN THE SLIGHT CHANCE CATEGORY...ALTHOUGH WITH MID LEVEL
TEMPERATURES FAVORABLE FOR ICE CRYSTAL GENERATION IT WOULD NOT
TAKE MUCH TO GENERATE AREAS OF LIGHT SNOW ANY OF THOSE PERIODS IF
MOISTURE IS PRESENT. WITH H85 TEMPERATURES OF -15 TO -25 FORECAST
TO SAG SWD THROUGH FA SAT/SUN...MAX TEMPERATURES MAY REMAIN IN
SINGLE DIGITS MANY AREAS SATURDAY AND POSSIBLY EVEN SUNDAY NRN
ZONES WITH MEX/ECE GUIDANCE POSSIBLY INFLUENCED BY CLIMO WITH
NORMAL HIGHS NOW APPROACHING OR EXCEEDING 40 DEGREES F. TRIMMED
BACK HIGHS A BIT SATURDAY/SUNDAY. LEFT LOWS MOSTLY ALONE FOR
NOW...SINGLE DIGITS EITHER SIDE OF ZERO F...AS CLOUD INFLUENCES
ENOUGH OF A THREAT WITH THE WEST OR POSSIBLY SW MID LEVEL FLOW
RIDING OVER COLD LOW LEVEL FLOW.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 520 AM CST TUE FEB 25 2014
AS HIGH PRESSURE BUILDS SOUTH INTO NRN NEBRASKA THIS MORNING MVFR
CIGS SHOULD CONTINUE TO CLEAR SOUTH OF KLNK/KOMA AND LIGHT SNOW
SHOULD ALSO END. HOWEVER...MID LEVEL CLOUDS...GENERALLY WITH ANY
CIGS ABV FL070...WILL SPREAD/DEVELOP ESE INTO ERN NEBR LATER THIS
MORNING THROUGH THIS AFTERNOON AS A DISTURBANCE MOVES ACROSS THE
STATE. SOME LIGHT SNOW COULD DEVELOP AS WELL...BUT INDICATIONS AT
12Z TAF ISSUANCE TIME WERE THAT ANY SIGNIFICANT IMPACT WOULD BE W
THROUGH S OF TAF SITES THUS NO MENTION WAS MADE.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MAYES
LONG TERM...CHERMOK
AVIATION...CHERMOK
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
300 AM CST TUE FEB 25 2014
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 259 AM CST TUE FEB 25 2014
CLOUDS AND OCCASIONAL FLURRIES ARE LINGERING IN THE AREA. SUBJECTIVE
00Z UPPER AIR ANALYSIS INDICATES UPPER-LEVEL SHORTWAVE TROUGH NEAR
THE SD/ND BORDER...WITH 500MB HEIGHT FALLS UP TO 90M AHEAD OF IT IN
EASTERN SD. 08Z WATER VAPOR AND RAP 1.5 PVU PRESSURE INDICATE
STRONG UPPER-LEVEL TROUGH DIGGING THROUGH IA THIS MORNING...WITH
SECONDARY SHORTWAVE UPSTREAM IN NORTHERN MT. STRONGEST UPPER-LEVEL
JET EXTENDED FROM MT THROUGH WESTERN SD INTO EASTERN NEB/IA AND
EASTWARD ACROSS THE MID-ATLANTIC. MUCH COLDER AIR WAS FILTERING
INTO THE PLAINS IN WAKE OF THE TROUGH...WITH 850MB TEMPERATURES -20C
OR COLDER IN ND/MT AND UPPER TEENS BELOW ZERO SPILLING INTO SD.
MAIN FORECAST CONCERN IS POTENTIAL FOR LIGHT SNOW TO CLIP THE
SOUTHWEST CWA TODAY...THEN ONE MORE DAY OF MODERATE TEMPERATURES
BEFORE THE COLD AIR PLUNGES INTO THE PLAINS. WEAK LIFT IN THE
DENDRITIC ZONE WILL EXIT THE AREA BY THIS MORNING...AND FLURRIES
SHOULD END FOR A TIME. SECOND...WEAKER SHORTWAVE WILL SLIDE THROUGH
THE NORTHERN ROCKIES TOWARD WESTERN/CENTRAL NEB TODAY...WITH WEAK
FRONTOGENETIC BAND AROUND 700-650MB SETTING UP FROM WESTERN TO SOUTH
CENTRAL NEB THIS AFTERNOON. SHOULD SEE SNOW WITH THAT BAND...BUT
EASTERN EXTENT IS IN QUESTION AS BETTER SUPPORT REMAINS WEST OF THE
AREA...AND DRIER LOW-LEVEL AIR BELOW THE MORE SATURATED MID-LEVELS
MAY HINDER MEASURABLE SNOW. HAVE CONTINUED TO INDICATE SLIGHT CHANCE
OF SNOW IN SOUTHEAST NEB THIS AFTERNOON...TAPERING AWAY BY THIS
EVENING.
WESTERLY WINDS RETURN TO THE AREA ON WEDNESDAY. WHILE SNOW ON THE
GROUND WILL HINDER TEMPERATURES IN THE NORTHERN CWA...THE COUPLE OF
TENTHS THAT FELL ELSEWHERE ARE NOT LIKELY TO COUNTERACT THE
FAVORABLE MIXING WINDS. HAVE KEPT TEMPS ABOVE GUIDANCE IN THE 30S
ACROSS MOST OF THE AREA...AS THE LAST DAY THAT COULD RISE ABOVE
FREEZING FOR QUITE SOME TIME. REINFORCING COLD AIR ARRIVES ON
WEDNESDAY NIGHT/THURSDAY AS A COLD AND DRY HIGH PRESSURE SLIDES OUT
OF THE DAKOTAS/MN INTO WESTERN IA. MID-LEVEL WARM AIR ADVECTION IS
PROGGED TO DEVELOP ON THE WESTERN SIDE OF THE HIGH ON THURSDAY
NIGHT...BUT GIVEN DRY AIR FEEDING IN FROM THE EAST...BELIEVE PRECIP
WILL BE HELD AT BAY THROUGH 12Z FRIDAY. MODELS HAVE TRENDED IN THAT
DIRECTION AS WELL...WITH ALL SOLUTIONS BUT THE NAM NOW DRY FOR
THURSDAY NIGHT. HAVE REMOVED POPS ACROSS THE AREA.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 259 AM CST TUE FEB 25 2014
ALTHOUGH THERE IS A BRIEF ATTEMPT AT MODERATION ON FRIDAY...PATTERN
TURNS COLDER THROUGH THE WEEKEND/MONDAY...WITH MUCH BELOW
NORMAL TEMPERATURES AND CHANCES OF LIGHT SNOW PERSISTING.
GOOD AGREEMENT BETWEEN 00Z GFS/ECMWF IN A DECENT H7 LOW/TROUGH
MOVING ALONG KS BORDER FRIDAY BRINGING MODEST SNOW CHANCES TO MUCH
OF THE FA...ESPECIALLY CNTRL/SRN ZONES. AFTER THAT THE COLD AIR IS
REINFORCED OVER THE NRN/CENTRAL PLAINS AS SEVERAL LOBES PIVOT AROUND
HUDSON BAY LOW SENDING COLD HIGH PRESSURE SOUTHWARD. MEANWHILE...
THE MID LEVEL FLOW OVER THE PLAINS REMAINS MORE WRLY AND EVEN
SWRLY AT TIMES. THUS PERIODS OF SNOW CHANCES WILL
PERSIST...ALTHOUGH NO MAJOR SYSTEMS WERE CURRENTLY SUGGESTED FOR
FA BY 00Z MODELS. BASED ON 00Z RUNS OF GFS/ECMWF IT DOES APPEAR
SOMEWHAT OF A LULL POSSIBLE FRIDAY NIGHT OVER MUCH OF THE
AREA...SATURDAY ACROSS THE SOUTH AND THEN MOST OF THE REGION BY
MONDAY. PRECIPITATION MENTION DURING THOSE TIMES WAS KEPT MOSTLY
IN THE SLIGHT CHANCE CATEGORY...ALTHOUGH WITH MID LEVEL
TEMPERATURES FAVORABLE FOR ICE CRYSTAL GENERATION IT WOULD NOT
TAKE MUCH TO GENERATE AREAS OF LIGHT SNOW ANY OF THOSE PERIODS IF
MOISTURE IS PRESENT. WITH H85 TEMPERATURES OF -15 TO -25 FORECAST
TO SAG SWD THROUGH FA SAT/SUN...MAX TEMPERATURES MAY REMAIN IN
SINGLE DIGITS MANY AREAS SATURDAY AND POSSIBLY EVEN SUNDAY NRN
ZONES WITH MEX/ECE GUIDANCE POSSIBLY INFLUENCED BY CLIMO WITH
NORMAL HIGHS NOW APPROACHING OR EXCEEDING 40 DEGREES F. TRIMMED
BACK HIGHS A BIT SATURDAY/SUNDAY. LEFT LOWS MOSTLY ALONE FOR
NOW...SINGLE DIGITS EITHER SIDE OF ZERO F...AS CLOUD INFLUENCES
ENOUGH OF A THREAT WITH THE WEST OR POSSIBLY SW MID LEVEL FLOW
RIDING OVER COLD LOW LEVEL FLOW.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1118 PM CST MON FEB 24 2014
MVFR CEILINGS WILL LINGER OVERNIGHT...ESPECIALLY AT KOFK AND KOMA.
SNOW SHOULD GRADUALLY END BUT SOME RESTRICTIONS MAY OCCUR UNTIL AT
LEAST 09Z. NORTH OR NORTHWEST WINDS CONTINUE TO INCREASE AS THE
COLD FRONT PUSHES SOUTHEASTWARD. WINDS WILL DECREASE TUESDAY
MORNING.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MAYES
LONG TERM...CHERMOK
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1220 PM EST TUE FEB 25 2014
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT OFF THE VIRGINIA COAST TODAY. A COLD
FRONT WILL MOVE ACROSS THE AREA TONIGHT INTO WEDNESDAY...BRINGING
SOME SHOWERS. COLD HIGH PRESSURE WILL BRING WELL BELOW NORMAL
TEMPERATURES FROM WEDNESDAY INTO THE WEEKEND. A SIGNIFICANT WARM-
UP IS POSSIBLE FOR EARLY NEXT WEEK...ALONG WITH INCREASING RAIN
CHANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 12:30 PM TUESDAY...TEMPERATURES HAVE JUMPED UP MUCH HIGHER
THAN EXPECTED ALONG THE COAST AS IT APPEARS THE DEVELOPING WARM
FRONT HAS PUSHED ASHORE. HAVE ADJUSTED FORECAST ACCORDINGLY. BASED
ON LATEST GUIDANCE AND TRENDS HAVE ALSO REMOVED SLIGHT CHANCE POPS
FOR LATER THIS AFTERNOON. ANTICIPATE MINIMAL TWEAKS TO THE
OVERNIGHT FORECAST WITH THE MID-AFTERNOON UPDATE. PREVIOUS
DISCUSSION FOLLOWS:
A RATHER COMPLEX 24 HOURS IS AHEAD OF US WEATHER WISE. SURFACE HIGH
PRESSURE IS MOVING OFF THE DELMARVA COAST THIS MORNING...WITH
VEERING WINDS ALREADY OBSERVED OFFSHORE AT THE FRYING PAN SHOALS
BUOY. WARM FRONTOGENESIS IS OCCURRING JUST OFFSHORE AS THE AIRMASS
QUICKLY MODIFIES OVER RELATIVELY WARM WATER TEMPS. UP AT 300 MB
THERE ARE TWO BRANCHES OF THE JET DISCERNIBLE: THE POLAR JET LIES
ACROSS THE CENTRAL APPALACHIANS AND MID-ATLANTIC REGION...WHILE
THE SUBTROPICAL JET COMES OUT OF NORTHERN MEXICO AND CROSSES THE
GULF COAST. CIRRUS CLOUDS COVERING THE CAROLINAS EARLY THIS
MORNING ARE DUE TO A WEAK DISTURBANCE IN THE SUBTROPICAL JET OVER
NORTHERN FLORIDA THAT SHOULD BE OFFSHORE IN THE NEXT FEW HOURS.
A SECOND SUBTROPICAL JET DISTURBANCE WILL MOVE THROUGH THE
SOUTHERN MS VALLEY THIS AFTERNOON. OUR OFFSHORE WARM FRONT WILL BE
DRAWN INLAND TODAY BY SURFACE PRESSURE FALLS OCCURRING AHEAD OF
THIS DISTURBANCE. WITH SEVERAL HOURS OF MOSTLY SUNNY SKIES
EXPECTED THIS MORNING THIS SHOULD ALLOW TEMPERATURES TO RISE INTO
THE 60S AND LOWER 70S BY EARLY AFTERNOON...WARMEST SOUTH OF
FLORENCE AND CONWAY. DURING THE MID AND LATE AFTERNOON MOISTURE
WILL INCREASE FROM THE WEST BETWEEN 850 AND 700 MB. COUPLED WITH
MODEST ISENTROPIC LIFT ALONG THE 295K THETA SURFACE THIS COULD
PRODUCE ISOLATED SHOWERS. POPS ARE LIMITED TO 20 PERCENT AND
MAINLY FOR COASTAL LOCATIONS.
THIS EVENING THE BEST PRESSURE FALLS WILL SHIFT OFFSHORE AS A MUCH
STRONGER POLAR JET DISTURBANCE APPROACHES FROM THE NORTHWEST. THIS
WILL TAKE THE WARM FRONT ACROSS EAST-CENTRAL NORTH CAROLINA AND
PUSH IT SOUTHWARD AS A COLD FRONT BEHIND A DEEPENING SURFACE LOW
OFFSHORE...WITH COOLER AIR SURGING SOUTHWARD TO THE SANTEE RIVER
OVERNIGHT. ISENTROPIC FIELDS INDICATE LITTLE POTENTIAL FOR
PRECIPITATION DURING THE EVENING HOURS...HOWEVER INCREASING LIFT
AGAIN ALONG THE 295K THETA SURFACE VERY LATE TONIGHT SHOULD
PRODUCE AN AREA OF SHOWERS ACROSS SOUTH CAROLINA SPREADING TO THE
NC/SC COAST BY DAYBREAK.
BOTH THE 06Z GFS AND NAM LOOK WARMER WITH DAYTIME TEMPS TODAY THAN
THEIR 00Z COUNTERPARTS DID. THE INTER MODEL DIFFERENCES BETWEEN THE
NEW GFS AND NAM HAVE DECREASED RELATIVE TO THE LARGER DIFFERENCES
DISPLAYED ON THE 00Z RUNS WHERE THE GFS APPEARED MUCH TOO COLD.
BASED ON THIS TREND AND THE LATEST FEW RUNS OF THE RUC I HAVE
RAISED HIGH TEMP FORECASTS TODAY...EXPANDING THE AREA OF LOWER 70S
IN THE KINGSTREE-GEORGETOWN-CONWAY AREA THIS AFTERNOON. UPPER 60S
ARE FORECAST FOR MOST AREAS EAST OF I-95 AND SOUTH OF
ELIZABETHTOWN. LOWER TO MID 60S ARE STILL EXPECTED NORTH OF
FLORENCE...DILLON... ELIZABETHTOWN AND WATHA.
FOR TONIGHT: THE 00Z NAM MODEL APPEARS TO HAVE A BETTER HANDLE ON
THE DEVELOPMENT AND MOVEMENT OF THE WARM FRONT TODAY AND THE
OFFSHORE LOW TONIGHT. THE NAM`S MAX/MIN TEMPERATURES ALSO APPEAR
BETTER THAN THE GFS... ALTHOUGH IT IS CURIOUS WHY BOTH THE NAM AND
GFS MOS PRODUCTS ARE SO COOL WITH HIGHS TODAY GIVEN RAW MODELS
RUNNING SEVERAL DEGREES WARMER. MY FORECAST HIGHS ARE WARMER THAN
NAM OR GFS MOS... PARTICULARLY NEAR THE COAST.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...COLD FRONT WILL BE DRAPED ALONG OR JUST
SOUTH AND OFFSHORE OF THE CWA AT THE START OF THE PERIOD. MOST
DIFFICULT PART OF THE FORECAST WILL BE HOW THE INTERACTION OF THIS
BOUNDARY AND SOME ENHANCED MOISTURE RETURN WILL AFFECT THE CWA
WITH RAINFALL ON WEDNESDAY. THE COLD FRONT WILL MOVE ONLY VERY
SLOWLY SOUTHWARD AS THE REGION REMAINS BENEATH THE BASE OF THE
EASTERN TROUGH...THUS FLOW BECOMES NEARLY BOUNDARY-PARALLEL ON
WEDNESDAY. AS THIS FRONT STALLS NEAR THE AREA...MOISTURE INCREASES
ALONG IT...AND SOME WEAK LIFT DUE TO MID-LEVEL IMPULSES WILL TRY
TO SPAWN SOME POST-FRONTAL RAINFALL ACROSS THE CWA. NAM/GFS ARE
WETTER AND IN BETTER AGREEMENT THAN THE ECMWF...SO WILL LEAN MORE
ON THESE MODELS FOR PRECIP POTENTIAL ON WEDNESDAY. THE BEST
CHANCES FOR PRECIP WILL BE ALONG THE SE THIRD OF THE CWA...CLOSEST
TO THE BOUNDARY AND WHERE ISENTROPIC LIFT FROM 290-300K IS
FOCUSED...BUT SREF PROBS SUGGEST AT LEAST 60% 12-HR CHANCE OF 0.01
QPF ACROSS THE ENTIRE CWA. INHERITED POP HAS LIKELY ACROSS THE
EAST WITH HIGH-CHC WEST...AND WILL BUMP THESE NUMBERS BUT KEEP
WITHIN THE SAME CATEGORIES FOR WEDNESDAY. HIGHEST CHANCES WILL BE
WED MORNING INTO THE AFTN...DROPPING FROM NW TO SE THROUGH THE EVE
AS THE FRONT DRIFTS SLOWLY AWAY AND THE MID-LEVEL IMPULSE PUSHES
EASTWARD.
WHILE THE WEAK CAA...CLOUDS...AND RAIN WILL KEEP TEMPS WEDNESDAY
WELL BELOW NORMAL...AROUND 50 FOR HIGHS...SKY CONDITIONS WILL
CLEAR RAPIDLY WED NIGHT. AT THE SAME TIME...HIGH PRESSURE FROM THE
WEST WILL CONTINUE TO RIDGE TOWARDS THE AREA. A RELATIVELY WEAK
PRESSURE GRADIENT WED NIGHT WILL LEAVE ONLY LIGHT NORTH WINDS
AHEAD OF THIS HIGH PRESSURE...WHICH COMBINED WITH CLEARING SKY
CONDITIONS WILL CREATE A COLD NIGHT INTO THU MORNING...AND EXPECT
NEARLY THE ENTIRE AREA TO FALL BELOW FREEZING...WITH MID 20S
POSSIBLE IN THE TYPICALLY COLDER SPOTS.
SUBTLE AIR MASS MODIFICATION OCCURS THURSDAY THANKS TO SURFACE
HIGH PRESSURE RIDGE AXIS BULGING UP TOWARDS THE MID-ATLANTIC. THIS
WILL BE SOMEWHAT OFFSET BY CONTINUED LOW THICKNESSES SOUTH OF THE
COLD 5H VORTEX ACROSS NEW ENGLAND...AND THUS WHILE THURSDAY WILL
BE WARMER THAN WEDNESDAY...TEMPS WILL STAY BELOW NORMAL...RISING
ONLY INTO THE MID 50S...WITH A FEW UPPER 50S POSSIBLE NEAR THE
SOUTH SANTEE RIVER. A RENEWED SURGE OF COLD AIR IS NOW PROGGED FOR
THURSDAY NIGHT AS A SECONDARY DRY COLD FRONT CROSSES AHEAD OF
ARCTIC HIGH PRESSURE DROPPING OUT OF CANADA. THIS WILL CREATE A
COLD AND BREEZY NIGHT THURSDAY NIGHT...AS LOW DROP ONCE AGAIN TO
FREEZING OR BELOW...WITH EVEN COLDER APPARENT TEMPS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 AM TUESDAY...COLD TO START THE EXTENDED AS ARCTIC HIGH
PRESSURE DEVELOPS INTO A WEDGE ALONG THE EAST COAST. THIS WILL
CREATE COOL NE WINDS INTO THE FIRST HALF OF THE WKND...WITH TEMPS
REMAINING SOLIDLY BELOW CLIMO FOR THE END OF FEBRUARY. WHILE
GUIDANCE HAS BEEN ADVERTISING A SOUTHERN STREAM LOW FOR SEVERAL
DAYS NOW...THIS FEATURE HAS BECOME LESS INTENSE...AND NOW THE
SURFACE REFLECTION HAS BASICALLY DISAPPEARED THANKS TO WEAKER MID-
LEVEL FORCING AND BAROCLINIC INSTABILITY. STILL...THERE IS AT
LEAST DECENT POTENTIAL FOR SOME SHOWERS ON SATURDAY BENEATH THE
MID-LEVEL IMPULSE...BUT OVERALL QPF LOOKS LIMITED.
ADDITIONALLY...WITH THE COOL AIR IN PLACE WITHIN THE WEDGE...THIS
OVERRUNNING SCENARIO MAY PROMOTE A MIXED P-TYPE EVENT...ESPECIALLY
WELL INLAND. TEMPS WILL BE MARGINAL AT-BEST FOR ANYTHING OTHER
THAN THAT LIQUID...AND WILL KEEP -RW AS WX TYPE FOR NOW...BUT
THERE IS AT LEAST A SMALL CHANCE FOR SOME FROZEN PRECIP FRIDAY
NIGHT/SAT AM.
GUIDANCE DIFFERS CONSIDERABLY INTO THE BEGINNING OF NEXT WEEK. GFS
BREAKS DOWN THE WEDGE QUICKLY AS MID-LEVEL RIDGING
DEVELOPS...CENTERED OFF THE FLORIDA COAST. ECMWF SHOWS A SIMILAR
PROCESS BUT WITH A SLOWER TEMPORAL EVOLUTION. THIS CAUSES 15+
DEGREE TEMP DIFFERENCES IN THE FORECASTS FOR NEXT WEEK. A QUICK
GLANCE AT SOME OF THE ENSEMBLES SUGGESTS THAT THE OP-GFS IS WELL
TOO WARM AS IT IS ON THE HIGH SIDE OF ALL ITS ENSEMBLE
THICKNESSES. STILL...THE UPPER PATTERN FAVORS WEDGE BREAKDOWN AND
AT LEAST A MARGINAL WARMUP SUN/MON...SO WILL BUMP TEMPS TOWARDS
AND ABOVE CLIMO FOR EARLY NEXT WEEK. A MORE IMPRESSIVE LOW
PRESSURE SYSTEM MAY APPROACH MONDAY...AND WILL KEEP INHERITED CHC
POP ATTM.
&&
.AVIATION /18Z TUESDAY THROUGH SATURDAY/...
AS OF 18Z...VISIBLE SATELLITE IMAGERY SHOWS LOW AND MID LEVEL CLOUDS
APPROACHING FROM THE WEST ASSOCIATED WITH A NARROW BAND OF
ISENTROPIC LIFT. WILL MENTION VCSH FOR ALL TERMS AS RADAR SHOWS SOME
VERY LIGHT RETURNS OFF TO OUR WEST...BUT ANY -RA THAT DOES DEVELOP
SHOULD HAVE LIMITED AVIATION IMPACTS. EXPECT VFR THROUGH THE AFTN
HOURS WITH WEST-SOUTHWEST WINDS AROUND 10 KTS. THE PATTERN WILL
QUICKLY CHANGE THIS EVENING AS LOW PRESSURE DEVELOPS OFF THE NC/VA
COAST. THIS LOW WILL PUSH A COLD FRONT THROUGH OUR CWA TONIGHT AS
SURFACE WINDS SHIFT FROM WEST TO NORTHEAST. THE LATEST NAM SOUNDINGS
SUPPORT AT LEAST MVFR CIGS DEVELOPING ACROSS MUCH OF THE AREA BY
DAYBREAK. CIGS AT THE COASTAL TERMS MAY DROP BELOW 1KFT...BUT SINCE
CONFIDENCE IS LOW ATTM...WILL JUST MENTION SCT IFR STRATUS WITH MVFR
CIGS. BY 12Z...RAIN WILL BECOME MORE WIDESPREAD WITH ANOTHER ROUND
OF MOIST ISENTROPIC LIFT AS THE FRONT LINGERS TO OUR SOUTH.
EXTENDED OUTLOOK...VFR THURSDAY AND FRIDAY. CHANCE OF RAIN/MVFR ON
SATURDAY. VFR SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 12:30 PM TUESDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:
SEASONS WILL CHANGE AT LEAST TWICE ACROSS THE COASTAL WATERS TODAY
AS A FRONT WAVERS ACROSS THE AREA. A WARM FRONT DEVELOPING ACROSS
THE COASTAL WATERS SHOULD PUSH INLAND LATER THIS MORNING...WITH
EAST WINDS VEERING TO THE SOUTH. WINDS SPEEDS WILL INCREASE TO
10-15 KNOTS AS DIRECTIONS CONTINUE TO VEER SOUTHWESTERLY DURING
THE AFTERNOON. THIS VEERING SHOULD BE IN RESPONSE TO FALLING
PRESSURES AS LOW PRESSURE DEVELOPS ALONG THE COAST TODAY...THEN
OFFSHORE THIS EVENING. CLOCKWISE WINDS BLOWING AROUND THIS LOW
SHOULD PUSH THE WARM FRONT BACK SOUTHWARD AS A COLD FRONT THIS
EVENING. THE FRONT MAY PRESS ALL THE WAY TO THE SANTEE
RIVER...WITH NORTH TO NORTHEAST WINDS STRONGEST ACROSS THE NC
WATERS CLOSEST TO THE POSITION OF THE LOW.
SEAS CURRENTLY RANGE FROM 2-3 FEET WITH DOMINANT PERIODS AROUND 9
SECONDS IN SOUTHEAST SWELL. A SMALL SHORT PERIOD CHOP WILL DEVELOP
IN THE SOUTH-SOUTHWEST WIND BEHIND THE WARM FRONT...WITH CONFUSED
SEAS FOR A PERIOD THIS EVENING AS WINDS SHIFT TO THE NORTH AS THE
FRONT IS PUSHED ACROSS AGAIN. TOTAL SEA HEIGHTS WILL PROBABLY NOT
EXCEED 4 FEET AT ANY POINT THROUGH TONIGHT.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...COLD FRONT MOVING OFFSHORE AT THE START OF
THE PERIOD WILL DRIFT SOUTH OF THE AREA INTO THURSDAY...WITH
NORTHERLY WINDS INCREASING TO 15-20 KTS...AND REMAINING AT THESE
SPEEDS INTO THURSDAY MORNING. THESE WINDS WILL EASE AND BACK TO
THE SW ON THURSDAY AS A RIDGE OF HIGH PRESSURE BRIEFLY ENVELOPS
THE AREA...BUT WILL QUICKLY RETURN TO THE NORTH AT 15-20 KTS AT
THE END OF THE PERIOD AS A SECOND COLD SURGE MOVES ACROSS THE
WATERS. EVEN THOUGH WINDS WILL BE GUSTY ON WEDNESDAY...THE
NORTHERLY COMPONENT WILL INHIBIT SUBSTANTIAL WAVE GROWTH...AND
THUS SEAS WILL RISE TO PEAK AT 3-5 FT WEDNESDAY EVE...BEFORE
FALLING BACK TO 1-3 FT DURING THURSDAY. RENEWED AMPLIFICATION IS
EXPECTED AT THE END OF THE SHORT TERM AS THE WINDS ONCE AGAIN RISE
FROM THE NORTH...WITH WAVE HEIGHTS BECOMING 2-4 FT BY FRIDAY
MORNING.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 300 AM TUESDAY...DEVELOPING WEDGE OF HIGH PRESSURE EXTENDING
DOWN THE EAST COAST WILL CREATE A PROLONGED PERIOD OF NE WINDS
OVER THE COASTAL WATERS...AND CAUTIONARY STATEMENTS MAY BE
REQUIRED ON FRIDAY. STRENGTHENING WEDGE FRIDAY FORCES A PINCHED
PRESSURE GRADIENT...AND NE WINDS RISE TO AROUND 20 KTS ALL OF
FRIDAY...DRIVING SEAS UP TO 4-5 FT...EXCEPT SW OF BRUNSWICK COUNTY
WHERE THE WAVE SHADOW REGION WILL PERMIT ONLY MUCH SMALLER WAVE
HEIGHTS. GRADIENT WILL EASE AT LEAST MARGINALLY ON
SATURDAY...ALLOWING NE WINDS TO FALL TO 10-15 KTS...WITH SEAS
FOLLOWING TO 2-4 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...REK/TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...BJR
MARINE...REK/TRA/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
923 AM EST TUE FEB 25 2014
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT OFF THE VIRGINIA COAST TODAY. A COLD
FRONT WILL MOVE ACROSS THE AREA TONIGHT INTO WEDNESDAY...BRINGING
SOME SHOWERS. COLD HIGH PRESSURE WILL BRING WELL BELOW NORMAL
TEMPERATURES FROM WEDNESDAY INTO THE WEEKEND. A SIGNIFICANT WARM-
UP IS POSSIBLE FOR EARLY NEXT WEEK...ALONG WITH INCREASING RAIN
CHANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 9:30 AM TUESDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:
A RATHER COMPLEX 24 HOURS IS AHEAD OF US WEATHER WISE. SURFACE HIGH
PRESSURE IS MOVING OFF THE DELMARVA COAST THIS MORNING...WITH
VEERING WINDS ALREADY OBSERVED OFFSHORE AT THE FRYING PAN SHOALS
BUOY. WARM FRONTOGENESIS IS OCCURRING JUST OFFSHORE AS THE AIRMASS
QUICKLY MODIFIES OVER RELATIVELY WARM WATER TEMPS. UP AT 300 MB
THERE ARE TWO BRANCHES OF THE JET DISCERNIBLE: THE POLAR JET LIES
ACROSS THE CENTRAL APPALACHIANS AND MID-ATLANTIC REGION...WHILE
THE SUBTROPICAL JET COMES OUT OF NORTHERN MEXICO AND CROSSES THE
GULF COAST. CIRRUS CLOUDS COVERING THE CAROLINAS EARLY THIS
MORNING ARE DUE TO A WEAK DISTURBANCE IN THE SUBTROPICAL JET OVER
NORTHERN FLORIDA THAT SHOULD BE OFFSHORE IN THE NEXT FEW HOURS.
A SECOND SUBTROPICAL JET DISTURBANCE WILL MOVE THROUGH THE
SOUTHERN MS VALLEY THIS AFTERNOON. OUR OFFSHORE WARM FRONT WILL BE
DRAWN INLAND TODAY BY SURFACE PRESSURE FALLS OCCURRING AHEAD OF
THIS DISTURBANCE. WITH SEVERAL HOURS OF MOSTLY SUNNY SKIES
EXPECTED THIS MORNING THIS SHOULD ALLOW TEMPERATURES TO RISE INTO
THE 60S AND LOWER 70S BY EARLY AFTERNOON...WARMEST SOUTH OF
FLORENCE AND CONWAY. DURING THE MID AND LATE AFTERNOON MOISTURE
WILL INCREASE FROM THE WEST BETWEEN 850 AND 700 MB. COUPLED WITH
MODEST ISENTROPIC LIFT ALONG THE 295K THETA SURFACE THIS COULD
PRODUCE ISOLATED SHOWERS. POPS ARE LIMITED TO 20 PERCENT AND
MAINLY FOR COASTAL LOCATIONS.
THIS EVENING THE BEST PRESSURE FALLS WILL SHIFT OFFSHORE AS A MUCH
STRONGER POLAR JET DISTURBANCE APPROACHES FROM THE NORTHWEST. THIS
WILL TAKE THE WARM FRONT ACROSS EAST-CENTRAL NORTH CAROLINA AND
PUSH IT SOUTHWARD AS A COLD FRONT BEHIND A DEEPENING SURFACE LOW
OFFSHORE...WITH COOLER AIR SURGING SOUTHWARD TO THE SANTEE RIVER
OVERNIGHT. ISENTROPIC FIELDS INDICATE LITTLE POTENTIAL FOR
PRECIPITATION DURING THE EVENING HOURS...HOWEVER INCREASING LIFT
AGAIN ALONG THE 295K THETA SURFACE VERY LATE TONIGHT SHOULD
PRODUCE AN AREA OF SHOWERS ACROSS SOUTH CAROLINA SPREADING TO THE
NC/SC COAST BY DAYBREAK.
BOTH THE 06Z GFS AND NAM LOOK WARMER WITH DAYTIME TEMPS TODAY THAN
THEIR 00Z COUNTERPARTS DID. THE INTER MODEL DIFFERENCES BETWEEN THE
NEW GFS AND NAM HAVE DECREASED RELATIVE TO THE LARGER DIFFERENCES
DISPLAYED ON THE 00Z RUNS WHERE THE GFS APPEARED MUCH TOO COLD.
BASED ON THIS TREND AND THE LATEST FEW RUNS OF THE RUC I HAVE
RAISED HIGH TEMP FORECASTS TODAY...EXPANDING THE AREA OF LOWER 70S
IN THE KINGSTREE-GEORGETOWN-CONWAY AREA THIS AFTERNOON. UPPER 60S
ARE FORECAST FOR MOST AREAS EAST OF I-95 AND SOUTH OF
ELIZABETHTOWN. LOWER TO MID 60S ARE STILL EXPECTED NORTH OF
FLORENCE...DILLON... ELIZABETHTOWN AND WATHA.
FOR TONIGHT: THE 00Z NAM MODEL APPEARS TO HAVE A BETTER HANDLE ON
THE DEVELOPMENT AND MOVEMENT OF THE WARM FRONT TODAY AND THE
OFFSHORE LOW TONIGHT. THE NAM`S MAX/MIN TEMPERATURES ALSO APPEAR
BETTER THAN THE GFS... ALTHOUGH IT IS CURIOUS WHY BOTH THE NAM AND
GFS MOS PRODUCTS ARE SO COOL WITH HIGHS TODAY GIVEN RAW MODELS
RUNNING SEVERAL DEGREES WARMER. MY FORECAST HIGHS ARE WARMER THAN
NAM OR GFS MOS... PARTICULARLY NEAR THE COAST.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...COLD FRONT WILL BE DRAPED ALONG OR JUST
SOUTH AND OFFSHORE OF THE CWA AT THE START OF THE PERIOD. MOST
DIFFICULT PART OF THE FORECAST WILL BE HOW THE INTERACTION OF THIS
BOUNDARY AND SOME ENHANCED MOISTURE RETURN WILL AFFECT THE CWA
WITH RAINFALL ON WEDNESDAY. THE COLD FRONT WILL MOVE ONLY VERY
SLOWLY SOUTHWARD AS THE REGION REMAINS BENEATH THE BASE OF THE
EASTERN TROUGH...THUS FLOW BECOMES NEARLY BOUNDARY-PARALLEL ON
WEDNESDAY. AS THIS FRONT STALLS NEAR THE AREA...MOISTURE INCREASES
ALONG IT...AND SOME WEAK LIFT DUE TO MID-LEVEL IMPULSES WILL TRY
TO SPAWN SOME POST-FRONTAL RAINFALL ACROSS THE CWA. NAM/GFS ARE
WETTER AND IN BETTER AGREEMENT THAN THE ECMWF...SO WILL LEAN MORE
ON THESE MODELS FOR PRECIP POTENTIAL ON WEDNESDAY. THE BEST
CHANCES FOR PRECIP WILL BE ALONG THE SE THIRD OF THE CWA...CLOSEST
TO THE BOUNDARY AND WHERE ISENTROPIC LIFT FROM 290-300K IS
FOCUSED...BUT SREF PROBS SUGGEST AT LEAST 60% 12-HR CHANCE OF 0.01
QPF ACROSS THE ENTIRE CWA. INHERITED POP HAS LIKELY ACROSS THE
EAST WITH HIGH-CHC WEST...AND WILL BUMP THESE NUMBERS BUT KEEP
WITHIN THE SAME CATEGORIES FOR WEDNESDAY. HIGHEST CHANCES WILL BE
WED MORNING INTO THE AFTN...DROPPING FROM NW TO SE THROUGH THE EVE
AS THE FRONT DRIFTS SLOWLY AWAY AND THE MID-LEVEL IMPULSE PUSHES
EASTWARD.
WHILE THE WEAK CAA...CLOUDS...AND RAIN WILL KEEP TEMPS WEDNESDAY
WELL BELOW NORMAL...AROUND 50 FOR HIGHS...SKY CONDITIONS WILL
CLEAR RAPIDLY WED NIGHT. AT THE SAME TIME...HIGH PRESSURE FROM THE
WEST WILL CONTINUE TO RIDGE TOWARDS THE AREA. A RELATIVELY WEAK
PRESSURE GRADIENT WED NIGHT WILL LEAVE ONLY LIGHT NORTH WINDS
AHEAD OF THIS HIGH PRESSURE...WHICH COMBINED WITH CLEARING SKY
CONDITIONS WILL CREATE A COLD NIGHT INTO THU MORNING...AND EXPECT
NEARLY THE ENTIRE AREA TO FALL BELOW FREEZING...WITH MID 20S
POSSIBLE IN THE TYPICALLY COLDER SPOTS.
SUBTLE AIR MASS MODIFICATION OCCURS THURSDAY THANKS TO SURFACE
HIGH PRESSURE RIDGE AXIS BULGING UP TOWARDS THE MID-ATLANTIC. THIS
WILL BE SOMEWHAT OFFSET BY CONTINUED LOW THICKNESSES SOUTH OF THE
COLD 5H VORTEX ACROSS NEW ENGLAND...AND THUS WHILE THURSDAY WILL
BE WARMER THAN WEDNESDAY...TEMPS WILL STAY BELOW NORMAL...RISING
ONLY INTO THE MID 50S...WITH A FEW UPPER 50S POSSIBLE NEAR THE
SOUTH SANTEE RIVER. A RENEWED SURGE OF COLD AIR IS NOW PROGGED FOR
THURSDAY NIGHT AS A SECONDARY DRY COLD FRONT CROSSES AHEAD OF
ARCTIC HIGH PRESSURE DROPPING OUT OF CANADA. THIS WILL CREATE A
COLD AND BREEZY NIGHT THURSDAY NIGHT...AS LOW DROP ONCE AGAIN TO
FREEZING OR BELOW...WITH EVEN COLDER APPARENT TEMPS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 300 AM TUESDAY...COLD TO START THE EXTENDED AS ARCTIC HIGH
PRESSURE DEVELOPS INTO A WEDGE ALONG THE EAST COAST. THIS WILL
CREATE COOL NE WINDS INTO THE FIRST HALF OF THE WKND...WITH TEMPS
REMAINING SOLIDLY BELOW CLIMO FOR THE END OF FEBRUARY. WHILE
GUIDANCE HAS BEEN ADVERTISING A SOUTHERN STREAM LOW FOR SEVERAL
DAYS NOW...THIS FEATURE HAS BECOME LESS INTENSE...AND NOW THE
SURFACE REFLECTION HAS BASICALLY DISAPPEARED THANKS TO WEAKER MID-
LEVEL FORCING AND BAROCLINIC INSTABILITY. STILL...THERE IS AT
LEAST DECENT POTENTIAL FOR SOME SHOWERS ON SATURDAY BENEATH THE
MID-LEVEL IMPULSE...BUT OVERALL QPF LOOKS LIMITED.
ADDITIONALLY...WITH THE COOL AIR IN PLACE WITHIN THE WEDGE...THIS
OVERRUNNING SCENARIO MAY PROMOTE A MIXED P-TYPE EVENT...ESPECIALLY
WELL INLAND. TEMPS WILL BE MARGINAL AT-BEST FOR ANYTHING OTHER
THAN THAT LIQUID...AND WILL KEEP -RW AS WX TYPE FOR NOW...BUT
THERE IS AT LEAST A SMALL CHANCE FOR SOME FROZEN PRECIP FRIDAY
NIGHT/SAT AM.
GUIDANCE DIFFERS CONSIDERABLY INTO THE BEGINNING OF NEXT WEEK. GFS
BREAKS DOWN THE WEDGE QUICKLY AS MID-LEVEL RIDGING
DEVELOPS...CENTERED OFF THE FLORIDA COAST. ECMWF SHOWS A SIMILAR
PROCESS BUT WITH A SLOWER TEMPORAL EVOLUTION. THIS CAUSES 15+
DEGREE TEMP DIFFERENCES IN THE FORECASTS FOR NEXT WEEK. A QUICK
GLANCE AT SOME OF THE ENSEMBLES SUGGESTS THAT THE OP-GFS IS WELL
TOO WARM AS IT IS ON THE HIGH SIDE OF ALL ITS ENSEMBLE
THICKNESSES. STILL...THE UPPER PATTERN FAVORS WEDGE BREAKDOWN AND
AT LEAST A MARGINAL WARMUP SUN/MON...SO WILL BUMP TEMPS TOWARDS
AND ABOVE CLIMO FOR EARLY NEXT WEEK. A MORE IMPRESSIVE LOW
PRESSURE SYSTEM MAY APPROACH MONDAY...AND WILL KEEP INHERITED CHC
POP ATTM.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
OF 12Z...CURRENTLY VFR CONDITIONS PREVAIL ACROSS THE CWA WITH MID
TO HIGH CLOUDS MOVING OVERHEAD. LIGHT AND VARIABLE WINDS WILL
SHIFT TO THE SOUTH AND THEN SOUTHWEST BY MIDDAY AS A DEVELOPING
WARM FRONT OFFSHORE MOVES NORTHWARD. TIME-HEIGHT ANALYSIS SHOWS
INCREASING LOW TO MID LEVEL MOISTURE THIS AFTERNOON...AND WILL
KEEP VCSH FOR THE COASTAL SITES AS AN ISOLATED SHOWER CANNOT BE
RULED OUT. EXPECT SOUTHWEST WINDS AROUND 10 KTS THROUGH THE
AFTERNOON HOURS. THIS PATTERN WILL QUICKLY CHANGE THIS EVENING AS
LOW PRESSURE DEVELOPS OFF THE NC/VA COAST. THE WINDS OVERNIGHT
WILL BECOME N-NE ON THE BACK SIDE OF THIS LOW. LOW CLOUDS AND RAIN
CHANCES WILL INCREASE TOWARD DAYBREAK AS THE COLD FRONT REMAINS
DRAPED JUST TO OUR SOUTH. KFLO/KLBT MAY SEE MVFR CIGS DEVELOP BY
THE END OF THE VALID PERIOD AS A REGION OF ISENTROPIC LIFT AND -RA
SPREADS INTO OUR INLAND ZONES.
EXTENDED OUTLOOK...RAIN WITH MVFR CIGS ON WEDNESDAY. VFR THURSDAY
AND FRIDAY. CHANCE OF RAIN/MVFR ON SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 9:30 AM TUESDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:
SEASONS WILL CHANGE AT LEAST TWICE ACROSS THE COASTAL WATERS TODAY
AS A FRONT WAVERS ACROSS THE AREA. A WARM FRONT DEVELOPING ACROSS
THE COASTAL WATERS SHOULD PUSH INLAND LATER THIS MORNING...WITH
EAST WINDS VEERING TO THE SOUTH. WINDS SPEEDS WILL INCREASE TO
10-15 KNOTS AS DIRECTIONS CONTINUE TO VEER SOUTHWESTERLY DURING
THE AFTERNOON. THIS VEERING SHOULD BE IN RESPONSE TO FALLING
PRESSURES AS LOW PRESSURE DEVELOPS ALONG THE COAST TODAY...THEN
OFFSHORE THIS EVENING. CLOCKWISE WINDS BLOWING AROUND THIS LOW
SHOULD PUSH THE WARM FRONT BACK SOUTHWARD AS A COLD FRONT THIS
EVENING. THE FRONT MAY PRESS ALL THE WAY TO THE SANTEE
RIVER...WITH NORTH TO NORTHEAST WINDS STRONGEST ACROSS THE NC
WATERS CLOSEST TO THE POSITION OF THE LOW.
SEAS CURRENTLY RANGE FROM 2-3 FEET WITH DOMINANT PERIODS AROUND 9
SECONDS IN SOUTHEAST SWELL. A SMALL SHORT PERIOD CHOP WILL DEVELOP
IN THE SOUTH-SOUTHWEST WIND BEHIND THE WARM FRONT...WITH CONFUSED
SEAS FOR A PERIOD THIS EVENING AS WINDS SHIFT TO THE NORTH AS THE
FRONT IS PUSHED ACROSS AGAIN. TOTAL SEA HEIGHTS WILL PROBABLY NOT
EXCEED 4 FEET AT ANY POINT THROUGH TONIGHT.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...COLD FRONT MOVING OFFSHORE AT THE START OF
THE PERIOD WILL DRIFT SOUTH OF THE AREA INTO THURSDAY...WITH
NORTHERLY WINDS INCREASING TO 15-20 KTS...AND REMAINING AT THESE
SPEEDS INTO THURSDAY MORNING. THESE WINDS WILL EASE AND BACK TO
THE SW ON THURSDAY AS A RIDGE OF HIGH PRESSURE BRIEFLY ENVELOPS
THE AREA...BUT WILL QUICKLY RETURN TO THE NORTH AT 15-20 KTS AT
THE END OF THE PERIOD AS A SECOND COLD SURGE MOVES ACROSS THE
WATERS. EVEN THOUGH WINDS WILL BE GUSTY ON WEDNESDAY...THE
NORTHERLY COMPONENT WILL INHIBIT SUBSTANTIAL WAVE GROWTH...AND
THUS SEAS WILL RISE TO PEAK AT 3-5 FT WEDNESDAY EVE...BEFORE
FALLING BACK TO 1-3 FT DURING THURSDAY. RENEWED AMPLIFICATION IS
EXPECTED AT THE END OF THE SHORT TERM AS THE WINDS ONCE AGAIN RISE
FROM THE NORTH...WITH WAVE HEIGHTS BECOMING 2-4 FT BY FRIDAY
MORNING.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 300 AM TUESDAY...DEVELOPING WEDGE OF HIGH PRESSURE EXTENDING
DOWN THE EAST COAST WILL CREATE A PROLONGED PERIOD OF NE WINDS
OVER THE COASTAL WATERS...AND CAUTIONARY STATEMENTS MAY BE
REQUIRED ON FRIDAY. STRENGTHENING WEDGE FRIDAY FORCES A PINCHED
PRESSURE GRADIENT...AND NE WINDS RISE TO AROUND 20 KTS ALL OF
FRIDAY...DRIVING SEAS UP TO 4-5 FT...EXCEPT SW OF BRUNSWICK COUNTY
WHERE THE WAVE SHADOW REGION WILL PERMIT ONLY MUCH SMALLER WAVE
HEIGHTS. GRADIENT WILL EASE AT LEAST MARGINALLY ON
SATURDAY...ALLOWING NE WINDS TO FALL TO 10-15 KTS...WITH SEAS
FOLLOWING TO 2-4 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...REK/TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...TRA
MARINE...REK/TRA/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
636 AM EST TUE FEB 25 2014
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT OFF THE VIRGINIA COAST TODAY. A COLD FRONT
WILL MOVE ACROSS THE AREA TONIGHT INTO WEDNESDAY BRINGING SOME
SHOWERS. COLD HIGH PRESSURE WILL BRING WELL BELOW NORMAL
TEMPERATURES WEDNESDAY AND INTO THE WEEKEND. A SIGNIFICANT WARM-UP
IS POSSIBLE FOR EARLY NEXT WEEK...ALONG WITH INCREASING RAIN CHANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 63AM TUESDAY...A RATHER COMPLEX 24 HOURS IS AHEAD OF US
WEATHERWISE. SURFACE HIGH PRESSURE IS MOVING OFF THE DELMARVA COAST
THIS MORNING...WITH VEERING WINDS ALREADY OBSERVED OFFSHORE AT THE
FRYING PAN SHOALS BUOY. WARM FRONTOGENESIS IS OCCURRING JUST
OFFSHORE AS THE AIRMASS QUICKLY MODIFIES OVER RELATIVELY WARM WATER
TEMPS. UP AT 300 MB THERE ARE TWO BRANCHES OF THE JET DISCERNIBLE:
THE POLAR JET LIES ACROSS THE CENTRAL APPALACHIANS AND MID-ATLANTIC
REGION...WHILE THE SUBTROPICAL JET COMES OUT OF NORTHERN MEXICO AND
CROSSES THE GULF COAST. CIRRUS CLOUDS COVERING THE CAROLINAS EARLY
THIS MORNING ARE DUE TO A WEAK DISTURBANCE IN THE SUBTROPICAL JET
OVER NORTHERN FLORIDA THAT SHOULD BE OFFSHORE IN THE NEXT FEW HOURS.
A SECOND SUBTROPICAL JET DISTURBANCE WILL MOVE THROUGH THE SOUTHERN
MS VALLEY THIS AFTERNOON. OUR OFFSHORE WARM FRONT WILL BE DRAWN
INLAND TODAY BY SURFACE PRESSURE FALLS OCCURRING AHEAD OF THIS
DISTURBANCE. WITH SEVERAL HOURS OF MOSTLY SUNNY SKIES EXPECTED THIS
MORNING THIS SHOULD ALLOW TEMPERATURES TO RISE INTO THE 60S AND
LOWER 70S BY EARLY AFTERNOON...WARMEST SOUTH OF FLORENCE AND CONWAY.
DURING THE MID AND LATE AFTERNOON MOISTURE WILL INCREASE FROM THE
WEST BETWEEN 850 AND 700 MB. COUPLED WITH MODEST ISENTROPIC LIFT
ALONG THE 295K THETA SURFACE THIS COULD PRODUCE ISOLATED SHOWERS.
POPS ARE LIMITED TO 20 PERCENT AND MAINLY FOR COASTAL LOCATIONS.
THIS EVENING THE BEST PRESSURE FALLS WILL SHIFT OFFSHORE AS A MUCH
STRONGER POLAR JET DISTURBANCE APPROACHES FROM THE NORTHWEST. THIS
WILL TAKE THE WARM FRONT ACROSS EAST-CENTRAL NORTH CAROLINA AND PUSH
IT SOUTHWARD AS A COLD FRONT BEHIND A DEEPENING SURFACE LOW
OFFSHORE...WITH COOLER AIR SURGING SOUTHWARD TO THE SANTEE RIVER
OVERNIGHT. ISENTROPIC FIELDS INDICATE LITTLE POTENTIAL FOR
PRECIPITATION DURING THE EVENING HOURS...HOWEVER INCREASING LIFT
AGAIN ALONG THE 295K THETA SURFACE VERY LATE TONIGHT SHOULD PRODUCE
AN AREA OF SHOWERS ACROSS SOUTH CAROLINA SPREADING TO THE NC/SC
COAST BY DAYBREAK.
BOTH THE 06Z GFS AND NAM LOOK WARMER WITH DAYTIME TEMPS TODAY THAN
THEIR 00Z COUNTERPARTS DID. THE INTERMODEL DIFFERENCES BETWEEN THE
NEW GFS AND NAM HAVE DECREASED RELATIVE TO THE LARGER DIFFERENCES
DISPLAYED ON THE 00Z RUNS WHERE THE GFS APPEARED MUCH TOO COLD.
BASED ON THIS TREND AND THE LATEST FEW RUNS OF THE RUC I HAVE RAISED
HIGH TEMP FORECASTS TODAY...EXPANDING THE AREA OF LOWER 70S IN THE
KINGSTREE-GEORGETOWN-CONWAY AREA THIS AFTERNOON. UPPER 60S ARE
FORECAST FOR MOST AREAS EAST OF I-95 AND SOUTH OF ELIZABETHTOWN.
LOWER TO MID 60S ARE STILL EXPECTED NORTH OF FLORENCE...DILLON...
ELIZABETHTOWN AND WATHA.
FOR TONIGHT: THE 00Z NAM MODEL APPEARS TO HAVE A BETTER HANDLE ON
THE DEVELOPMENT AND MOVEMENT OF THE WARM FRONT TODAY AND THE
OFFSHORE LOW TONIGHT. THE NAM`S MAX/MIN TEMPERATURES ALSO APPEAR
BETTER THAN THE GFS... ALTHOUGH IT IS CURIOUS WHY BOTH THE NAM AND
GFS MOS PRODUCTS ARE SO COOL WITH HIGHS TODAY GIVEN RAW MODELS
RUNNING SEVERAL DEGREES WARMER. MY FORECAST HIGHS ARE WARMER THAN
NAM OR GFS MOS... PARTICULARLY NEAR THE COAST.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...COLD FRONT WILL BE DRAPED ALONG OR JUST SOUTH
AND OFFSHORE OF THE CWA AT THE START OF THE PERIOD. MOST DIFFICULT
PART OF THE FORECAST WILL BE HOW THE INTERACTION OF THIS BOUNDARY
AND SOME ENHANCED MOISTURE RETURN WILL AFFECT THE CWA WITH RAINFALL
ON WEDNESDAY. THE COLD FRONT WILL MOVE ONLY VERY SLOWLY SOUTHWARD AS
THE REGION REMAINS BENEATH THE BASE OF THE EASTERN TROUGH...THUS
FLOW BECOMES NEARLY BOUNDARY-PARALLEL ON WEDNESDAY. AS THIS FRONT
STALLS NEAR THE AREA...MOISTURE INCREASES ALONG IT...AND SOME WEAK
LIFT DUE TO MID-LEVEL IMPULSES WILL TRY TO SPAWN SOME POST-FRONTAL
RAINFALL ACROSS THE CWA. NAM/GFS ARE WETTER AND IN BETTER AGREEMENT
THAN THE ECMWF...SO WILL LEAN MORE ON THESE MODELS FOR PRECIP
POTENTIAL ON WEDNESDAY. THE BEST CHANCES FOR PRECIP WILL BE ALONG
THE SE THIRD OF THE CWA...CLOSEST TO THE BOUNDARY AND WHERE
ISENTROPIC LIFT FROM 290-300K IS FOCUSED...BUT SREF PROBS SUGGEST AT
LEAST 60% 12-HR CHANCE OF 0.01 QPF ACROSS THE ENTIRE CWA. INHERITED
POP HAS LIKELY ACROSS THE EAST WITH HIGH-CHC WEST...AND WILL BUMP
THESE NUMBERS BUT KEEP WITHIN THE SAME CATEGORIES FOR WEDNESDAY.
HIGHEST CHANCES WILL BE WED MORNING INTO THE AFTN...DROPPING FROM NW
TO SE THROUGH THE EVE AS THE FRONT DRIFTS SLOWLY AWAY AND THE
MID-LEVEL IMPULSE PUSHES EASTWARD.
WHILE THE WEAK CAA...CLOUDS...AND RAIN WILL KEEP TEMPS WEDNESDAY
WELL BELOW NORMAL...AROUND 50 FOR HIGHS...SKY CONDITIONS WILL CLEAR
RAPIDLY WED NIGHT. AT THE SAME TIME...HIGH PRESSURE FROM THE WEST
WILL CONTINUE TO RIDGE TOWARDS THE AREA. A RELATIVELY WEAK PRESSURE
GRADIENT WED NIGHT WILL LEAVE ONLY LIGHT NORTH WINDS AHEAD OF THIS
HIGH PRESSURE...WHICH COMBINED WITH CLEARING SKY CONDITIONS WILL
CREATE A COLD NIGHT INTO THU MORNING...AND EXPECT NEARLY THE ENTIRE
AREA TO FALL BELOW FREEZING...WITH MID 20S POSSIBLE IN THE TYPICALLY
COLDER SPOTS.
SUBTLE AIR MASS MODIFICATION OCCURS THURSDAY THANKS TO SURFACE HIGH
PRESSURE RIDGE AXIS BULGING UP TOWARDS THE MID-ATLANTIC. THIS WILL
BE SOMEWHAT OFFSET BY CONTINUED LOW THICKNESSES SOUTH OF THE COLD 5H
VORTEX ACROSS NEW ENGLAND...AND THUS WHILE THURSDAY WILL BE WARMER
THAN WEDNESDAY...TEMPS WILL STAY BELOW NORMAL...RISING ONLY INTO THE
MID 50S...WITH A FEW UPPER 50S POSSIBLE NEAR THE SOUTH SANTEE RIVER.
A RENEWED SURGE OF COLD AIR IS NOW PROGGED FOR THURSDAY NIGHT AS A
SECONDARY DRY COLD FRONT CROSSES AHEAD OF ARCTIC HIGH PRESSURE
DROPPING OUT OF CANADA. THIS WILL CREATE A COLD AND BREEZY NIGHT
THURSDAY NIGHT...AS LOW DROP ONCE AGAIN TO FREEZING OR BELOW...WITH
EVEN COLDER APPARENT TEMPS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 300 AM TUESDAY...COLD TO START THE EXTENDED AS ARCTIC HIGH
PRESSURE DEVELOPS INTO A WEDGE ALONG THE EAST COAST. THIS WILL
CREATE COOL NE WINDS INTO THE FIRST HALF OF THE WKND...WITH TEMPS
REMAINING SOLIDLY BELOW CLIMO FOR THE END OF FEBRUARY. WHILE
GUIDANCE HAS BEEN ADVERTISING A SOUTHERN STREAM LOW FOR SEVERAL DAYS
NOW...THIS FEATURE HAS BECOME LESS INTENSE...AND NOW THE SURFACE
REFLECTION HAS BASICALLY DISAPPEARED THANKS TO WEAKER MID-LEVEL
FORCING AND BAROCLINIC INSTABILITY. STILL...THERE IS AT LEAST DECENT
POTENTIAL FOR SOME SHOWERS ON SATURDAY BENEATH THE MID-LEVEL
IMPULSE...BUT OVERALL QPF LOOKS LIMITED. ADDITIONALLY...WITH THE
COOL AIR IN PLACE WITHIN THE WEDGE...THIS OVERRUNNING SCENARIO MAY
PROMOTE A MIXED P-TYPE EVENT...ESPECIALLY WELL INLAND. TEMPS WILL BE
MARGINAL AT-BEST FOR ANYTHING OTHER THAN THAT LIQUID...AND WILL KEEP
-RW AS WX TYPE FOR NOW...BUT THERE IS AT LEAST A SMALL CHANCE FOR
SOME FROZEN PRECIP FRIDAY NIGHT/SAT AM.
GUIDANCE DIFFERS CONSIDERABLY INTO THE BEGINNING OF NEXT WEEK. GFS
BREAKS DOWN THE WEDGE QUICKLY AS MID-LEVEL RIDGING
DEVELOPS...CENTERED OFF THE FLORIDA COAST. ECMWF SHOWS A SIMILAR
PROCESS BUT WITH A SLOWER TEMPORAL EVOLUTION. THIS CAUSES 15+ DEGREE
TEMP DIFFERENCES IN THE FORECASTS FOR NEXT WEEK. A QUICK GLANCE AT
SOME OF THE ENSEMBLES SUGGESTS THAT THE OP-GFS IS WELL TOO WARM AS
IT IS ON THE HIGH SIDE OF ALL ITS ENSEMBLE THICKNESSES. STILL...THE
UPPER PATTERN FAVORS WEDGE BREAKDOWN AND AT LEAST A MARGINAL WARMUP
SUN/MON...SO WILL BUMP TEMPS TOWARDS AND ABOVE CLIMO FOR EARLY NEXT
WEEK. A MORE IMPRESSIVE LOW PRESSURE SYSTEM MAY APPROACH
MONDAY...AND WILL KEEP INHERITED CHC POP ATTM.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
OF 12Z...CURRENTLY VFR CONDITIONS PREVAIL ACROSS THE CWA WITH MID TO
HIGH CLOUDS MOVING OVERHEAD. LIGHT AND VARIABLE WINDS WILL SHIFT TO
THE SOUTH AND THEN SOUTHWEST BY MIDDAY AS A DEVELOPING WARM FRONT
OFFSHORE MOVES NORTHWARD. TIME-HEIGHT ANALYSIS SHOWS INCREASING LOW
TO MID LEVEL MOISTURE THIS AFTERNOON...AND WILL KEEP VCSH FOR THE
COASTAL SITES AS AN ISOLATED SHOWER CANNOT BE RULED OUT. EXPECT
SOUTHWEST WINDS AROUND 10 KTS THROUGH THE AFTERNOON HOURS. THIS
PATTERN WILL QUICKLY CHANGE THIS EVENING AS LOW PRESSURE DEVELOPS
OFF THE NC/VA COAST. THE WINDS OVERNIGHT WILL BECOME N-NE ON THE
BACK SIDE OF THIS LOW. LOW CLOUDS AND RAIN CHANCES WILL INCREASE
TOWARD DAYBREAK AS THE COLD FRONT REMAINS DRAPED JUST TO OUR SOUTH.
KFLO/KLBT MAY SEE MVFR CIGS DEVELOP BY THE END OF THE VALID PERIOD
AS A REGION OF ISENTROPIC LIFT AND -RA SPREADS INTO OUR INLAND ZONES.
EXTENDED OUTLOOK...RAIN WITH MVFR CIGS ON WEDNESDAY. VFR THURSDAY
AND FRIDAY. CHANCE OF RAIN/MVFR ON SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM TUESDAY...SEASONS WILL CHANGE AT LEAST TWICE ACROSS
THE COASTAL WATERS TODAY AS A FRONT WAVERS ACROSS THE AREA. A WARM
FRONT DEVELOPING ACROSS THE COASTAL WATERS SHOULD PUSH INLAND LATER
THIS MORNING...WITH EAST WINDS VEERING TO THE SOUTH. WINDS
SPEEDS WILL INCREASE TO 10-15 KNOTS AS DIRECTIONS CONTINUE TO VEER
SOUTHWESTERLY DURING THE AFTERNOON. THIS VEERING SHOULD BE IN
RESPONSE TO FALLING PRESSURES AS LOW PRESSURE DEVELOPS ALONG THE
COAST TODAY...THEN OFFSHORE THIS EVENING. CLOCKWISE WINDS BLOWING
AROUND THIS LOW SHOULD PUSH THE WARM FRONT BACK SOUTHWARD AS A COLD
FRONT THIS EVENING. THE FRONT MAY PRESS ALL THE WAY TO THE SANTEE
RIVER...WITH NORTH TO NORTHEAST WINDS STRONGEST ACROSS THE NC WATERS
CLOSEST TO THE POSITION OF THE LOW.
SEAS CURRENTLY RANGE FROM 2-3 FEET WITH DOMINANT PERIODS AROUND 9
SECONDS IN SOUTHEAST SWELL. A SMALL SHORT PERIOD CHOP WILL DEVELOP
IN THE SOUTH-SOUTHWEST WIND BEHIND THE WARM FRONT...WITH CONFUSED
SEAS FOR A PERIOD THIS EVENING AS WINDS SHIFT TO THE NORTH AS THE
FRONT IS PUSHED ACROSS AGAIN. TOTAL SEA HEIGHTS WILL PROBABLY NOT
EXCEED 4 FEET AT ANY POINT THROUGH TONIGHT.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...COLD FRONT MOVING OFFSHORE AT THE START OF
THE PERIOD WILL DRIFT SOUTH OF THE AREA INTO THURSDAY...WITH
NORTHERLY WINDS INCREASING TO 15-20 KTS...AND REMAINING AT THESE
SPEEDS INTO THURSDAY MORNING. THESE WINDS WILL EASE AND BACK TO THE
SW ON THURSDAY AS A RIDGE OF HIGH PRESSURE BRIEFLY ENVELOPS THE
AREA...BUT WILL QUICKLY RETURN TO THE NORTH AT 15-20 KTS AT THE END
OF THE PERIOD AS A SECOND COLD SURGE MOVES ACROSS THE WATERS. EVEN
THOUGH WINDS WILL BE GUSTY ON WEDNESDAY...THE NORTHERLY COMPONENT
WILL INHIBIT SUBSTANTIAL WAVE GROWTH...AND THUS SEAS WILL RISE TO
PEAK AT 3-5 FT WEDNESDAY EVE...BEFORE FALLING BACK TO 1-3 FT DURING
THURSDAY. RENEWED AMPLIFICATION IS EXPECTED AT THE END OF THE SHORT
TERM AS THE WINDS ONCE AGAIN RISE FROM THE NORTH...WITH WAVE HEIGHTS
BECOMING 2-4 FT BY FRIDAY MORNING.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 300 AM TUESDAY...DEVELOPING WEDGE OF HIGH PRESSURE EXTENDING
DOWN THE EAST COAST WILL CREATE A PROLONGED PERIOD OF NE WINDS OVER
THE COASTAL WATERS...AND CAUTIONARY STATEMENTS MAY BE REQUIRED ON
FRIDAY. STRENGTHENING WEDGE FRIDAY FORCES A PINCHED PRESSURE
GRADIENT...AND NE WINDS RISE TO AROUND 20 KTS ALL OF
FRIDAY...DRIVING SEAS UP TO 4-5 FT...EXCEPT SW OF BRUNSWICK COUNTY
WHERE THE WAVE SHADOW REGION WILL PERMIT ONLY MUCH SMALLER WAVE
HEIGHTS. GRADIENT WILL EASE AT LEAST MARGINALLY ON
SATURDAY...ALLOWING NE WINDS TO FALL TO 10-15 KTS...WITH SEAS
FOLLOWING TO 2-4 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1253 PM CST TUE FEB 25 2014
.UPDATE...
ISSUED AT 1253 PM CST TUE FEB 25 2014
NO SIGNIFICANT CHANGES TO FORECAST WITH COLD CONDITIONS AND SUNNY
SKIES CONTINUING. WILL CONTINUE TO LOOK FOR AREAS NEEDING WIND
CHILL ADVISORY TONIGHT AS WELL AS POSSIBLE WIND ADVISORY FOR
EASTERN AREAS TOMORROW.
UPDATE ISSUED AT 1010 AM CST TUE FEB 25 2014
MAIN CHANGES FOR UPDATE WERE TO DECREASE SKY COVER AND ALLOW THE
WIND CHILL ADVISORY TO EXPIRE. WIND CHILLS VALUES HAD COME UP MOST
AREAS AND THE COLDEST NORTHERN LOCATIONS CONTINUE TO SEE GRADUALLY
INCREASING TEMPS...THOUGH A COLD DAY STILL EXPECTED WITH SINGLE
DIGIT HIGHS. MAIN CONCERNS LOOKING FORWARD ARE WIND CHILLS AGAIN
TONIGHT AND STRONGER WINDS ON WEDNESDAY...PARTICULARLY ACROSS THE
EAST.
UPDATE ISSUED AT 637 AM CST TUE FEB 25 2014
THE CURRENT FORECAST IS ON TRACK. NO MAJOR UPDATES WERE REQUIRED.
ONLY ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 308 AM CST TUE FEB 25 2014
THE MAIN FORECAST CONCERN WILL BE WIND CHILL HEADLINES. EARLY
MORNING SURFACE ANALYSIS SHOWS SURFACE HIGH PRESSURE STRETCHING
FROM EASTERN MONTANA INTO SOUTHEAST SOUTH DAKOTA. TEMPERATURES
EARLY THIS MORNING WERE IN THE SINGLE DIGITS AND TEENS BELOW ZERO
WITH WINDS OF 5 TO 10 MPH. THIS HAS DROPPED WIND CHILLS INTO
ADVISORY LEVELS ACROSS MUCH OF WESTERN AND CENTRAL NORTH
DAKOTA...THE EXCEPTION BEING FAR WEST CENTRAL NORTH DAKOTA WHERE
WINDS REMAIN WEAKEST.
THE FAR SOUTHWEST HAS ALSO SEEN AN INCREASE IN MID AND HIGH LEVEL
CLOUDS EARLY THIS MORNING HELPING TEMPERATURES GAIN A FEW DEGREES
OVER THE PAST COUPLE OF HOURS. NOT CONFIDENT THAT TREND WILL
CONTINUE SINCE THE LATEST HRRR SUGGESTS THE CLOUDS WILL SINK SOUTH
AGAIN THIS MORNING. OVERALL...THE WIND CHILL HEADLINE IS STILL
SUPPORTED BY THE LATEST OBSERVATIONS AND WILL NOT MAKE ANY CHANGES
TO IT.
WIND CHILLS WILL AGAIN BE THE MAIN CONCERN TONIGHT WITH LOWS OF 5
TO 15 BELOW AND WIND SPEEDS OF 10 MPH...INCREASING TO NEAR 20 MPH
OVERNIGHT. THIS AGAIN DROPS WIND CHILLS IN THE 25 TO 35 BELOW
RANGE ACROSS MUCH OF THE NORTH AND EAST. WILL KEEP THINGS SIMPLE
AND NOT ISSUE ADDITIONAL HEADLINES...BUT EXPECT LATER SHIFTS WILL
LIKELY NEED TO CONSIDER THAT POSSIBILITY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 308 AM CST TUE FEB 25 2014
THE MAIN HIGHLIGHTS FOR THE EXTENDED WILL BE THE WELL BELOW NORMAL
TEMPERATURES AND SNOW CHANCES THIS WEEKEND. MODELS ARE IN FAIRLY
GOOD AGREEMENT SO USED A BLEND FOR THIS PACKAGE.
WEDNESDAY STILL LOOKS TO BE THE WARMEST DAY OF THE WEEK WITH HIGHS
GENERALLY FROM THE TEENS EAST TO THE MID 20S SOUTHWEST.
HOWEVER...IT WILL ALSO BE THE WINDIEST DAY OF THE PERIOD AS HIGH
PRESSURE SURGES INTO THE REGION. SNOW FROM MONDAY`S EVENT COMBINED
WITH THESE WINDS SHOULD GENERATE PATCHY TO AREAS OF BLOWING
SNOW...MAINLY ON WEDNESDAY AFTERNOON. WINDS WILL DECREASE RAPIDLY
WEDNESDAY NIGHT AS HIGH PRESSURE SETTLES ACROSS THE REGION. COLD
AND DRY CONDITIONS WILL CONTINUE ACROSS THE REGION THURSDAY AS
HIGH PRESSURE SHIFTS EAST OF THE REGION.
BY FRIDAY...A REINFORCING COLD FRONT WILL PUSH THROUGH THE
NORTHERN PLAINS...WITH A BAROCLINIC ZONE SETTING UP OVER
SOUTHWESTERN NORTH DAKOTA. THIS WILL GENERATE A SLIGHT CHANCE FOR
SNOW OVER SOUTHWESTERN NORTH DAKOTA FRIDAY INTO FRIDAY NIGHT.
A SHORTWAVE ROTATING OVER THE NORTHERN ROCKIES AND INTO THE
NORTHERN PLAINS THIS WEEKEND IS PROGGED TO LIFT THE SNOW CHANCES
NORTH SATURDAY AND SUNDAY. HOWEVER...GIVEN THE WEAK UPPER LEVEL
FORCING...SNOW AMOUNTS ARE EXPECTED TO REMAIN FAIRLY LIGHT.
AS THE UPPER WAVE DEPARTS THE STATE MONDAY...DRY CONDITIONS ARE
EXPECTED BY THE BEGINNING OF THE NEXT WORK WEEK. COLD TEMPERATURE
ARE FORECAST TO CONTINUE AS WELL WITH HIGHS IN THE SINGLE DIGITS
ABOVE ZERO.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1253 PM CST TUE FEB 25 2014
VFR CONDITIONS EXPECTED AT ALL SITES AS HIGH PRESSURE AND CLEAR
SKIES DOMINATE INTO WEDNESDAY. STRONGER WINDS WILL DEVELOP ON
WEDNESDAY...ESPECIALLY ACROSS THE EAST.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JNS
SHORT TERM...CK
LONG TERM...TM
AVIATION...JNS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1010 AM CST TUE FEB 25 2014
.UPDATE...
ISSUED AT 1010 AM CST TUE FEB 25 2014
MAIN CHANGES FOR UPDATE WERE TO DECREASE SKY COVER AND ALLOW THE
WIND CHILL ADVISORY TO EXPIRE. WIND CHILLS VALUES HAD COME UP MOST
AREAS AND THE COLDEST NORTHERN LOCATIONS CONTINUE TO SEE GRADUALLY
INCREASING TEMPS...THOUGH A COLD DAY STILL EXPECTED WITH SINGLE
DIGIT HIGHS. MAIN CONCERNS LOOKING FORWARD ARE WIND CHILLS AGAIN
TONIGHT AND STRONGER WINDS ON WEDNESDAY...PARTICULARLY ACROSS THE
EAST.
UPDATE ISSUED AT 637 AM CST TUE FEB 25 2014
THE CURRENT FORECAST IS ON TRACK. NO MAJOR UPDATES WERE REQUIRED.
ONLY ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 308 AM CST TUE FEB 25 2014
THE MAIN FORECAST CONCERN WILL BE WIND CHILL HEADLINES. EARLY
MORNING SURFACE ANALYSIS SHOWS SURFACE HIGH PRESSURE STRETCHING
FROM EASTERN MONTANA INTO SOUTHEAST SOUTH DAKOTA. TEMPERATURES
EARLY THIS MORNING WERE IN THE SINGLE DIGITS AND TEENS BELOW ZERO
WITH WINDS OF 5 TO 10 MPH. THIS HAS DROPPED WIND CHILLS INTO
ADVISORY LEVELS ACROSS MUCH OF WESTERN AND CENTRAL NORTH
DAKOTA...THE EXCEPTION BEING FAR WEST CENTRAL NORTH DAKOTA WHERE
WINDS REMAIN WEAKEST.
THE FAR SOUTHWEST HAS ALSO SEEN AN INCREASE IN MID AND HIGH LEVEL
CLOUDS EARLY THIS MORNING HELPING TEMPERATURES GAIN A FEW DEGREES
OVER THE PAST COUPLE OF HOURS. NOT CONFIDENT THAT TREND WILL
CONTINUE SINCE THE LATEST HRRR SUGGESTS THE CLOUDS WILL SINK SOUTH
AGAIN THIS MORNING. OVERALL...THE WIND CHILL HEADLINE IS STILL
SUPPORTED BY THE LATEST OBSERVATIONS AND WILL NOT MAKE ANY CHANGES
TO IT.
WIND CHILLS WILL AGAIN BE THE MAIN CONCERN TONIGHT WITH LOWS OF 5
TO 15 BELOW AND WIND SPEEDS OF 10 MPH...INCREASING TO NEAR 20 MPH
OVERNIGHT. THIS AGAIN DROPS WIND CHILLS IN THE 25 TO 35 BELOW
RANGE ACROSS MUCH OF THE NORTH AND EAST. WILL KEEP THINGS SIMPLE
AND NOT ISSUE ADDITIONAL HEADLINES...BUT EXPECT LATER SHIFTS WILL
LIKELY NEED TO CONSIDER THAT POSSIBILITY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 308 AM CST TUE FEB 25 2014
THE MAIN HIGHLIGHTS FOR THE EXTENDED WILL BE THE WELL BELOW NORMAL
TEMPERATURES AND SNOW CHANCES THIS WEEKEND. MODELS ARE IN FAIRLY
GOOD AGREEMENT SO USED A BLEND FOR THIS PACKAGE.
WEDNESDAY STILL LOOKS TO BE THE WARMEST DAY OF THE WEEK WITH HIGHS
GENERALLY FROM THE TEENS EAST TO THE MID 20S SOUTHWEST.
HOWEVER...IT WILL ALSO BE THE WINDIEST DAY OF THE PERIOD AS HIGH
PRESSURE SURGES INTO THE REGION. SNOW FROM MONDAY`S EVENT COMBINED
WITH THESE WINDS SHOULD GENERATE PATCHY TO AREAS OF BLOWING
SNOW...MAINLY ON WEDNESDAY AFTERNOON. WINDS WILL DECREASE RAPIDLY
WEDNESDAY NIGHT AS HIGH PRESSURE SETTLES ACROSS THE REGION. COLD
AND DRY CONDITIONS WILL CONTINUE ACROSS THE REGION THURSDAY AS
HIGH PRESSURE SHIFTS EAST OF THE REGION.
BY FRIDAY...A REINFORCING COLD FRONT WILL PUSH THROUGH THE
NORTHERN PLAINS...WITH A BAROCLINIC ZONE SETTING UP OVER
SOUTHWESTERN NORTH DAKOTA. THIS WILL GENERATE A SLIGHT CHANCE FOR
SNOW OVER SOUTHWESTERN NORTH DAKOTA FRIDAY INTO FRIDAY NIGHT.
A SHORTWAVE ROTATING OVER THE NORTHERN ROCKIES AND INTO THE
NORTHERN PLAINS THIS WEEKEND IS PROGGED TO LIFT THE SNOW CHANCES
NORTH SATURDAY AND SUNDAY. HOWEVER...GIVEN THE WEAK UPPER LEVEL
FORCING...SNOW AMOUNTS ARE EXPECTED TO REMAIN FAIRLY LIGHT.
AS THE UPPER WAVE DEPARTS THE STATE MONDAY...DRY CONDITIONS ARE
EXPECTED BY THE BEGINNING OF THE NEXT WORK WEEK. COLD TEMPERATURE
ARE FORECAST TO CONTINUE AS WELL WITH HIGHS IN THE SINGLE DIGITS
ABOVE ZERO.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 637 AM CST TUE FEB 25 2014
EARLY MORNING SATELLITE IMAGERY SHOWS VFR CONDITIONS ACROSS NORTH
DAKOTA. WILL CARRY VFR AT ALL TERMINAL LOCATIONS...HOWEVER HAVE
SOME CONCERN CLOUDS COULD DEVELOP TODAY AS A BAND OF H925-H85
MOISTURE MOVES ACROSS NORTH DAKOTA. THE HRRR EVEN SUGGESTS THERE
IS SOME POTENTIAL FOR MVFR CEILINGS FROM LATE MORNING INTO THE
AFTERNOON ACROSS THE WEST...POSSIBLY IMPACTING WILLISTON AND
DICKINSON. HAVE FORECAST SCATTERED CLOUDS AROUND 3500 FT...BUT DID
NOT NOT CARRY A CEILING SINCE FORECAST SOUNDINGS SUGGEST ANY
AVAILABLE MOISTURE SHOULD BE SHALLOW. WINDS WILL START LIGHT...BUT
WILL INCREASE FROM FROM THE NORTHWEST LATER THIS MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JNS
SHORT TERM...CK
LONG TERM...TM
AVIATION...CK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
638 AM CST TUE FEB 25 2014
.UPDATE...
ISSUED AT 637 AM CST TUE FEB 25 2014
THE CURRENT FORECAST IS ON TRACK. NO MAJOR UPDATES WERE REQUIRED.
ONLY ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 308 AM CST TUE FEB 25 2014
THE MAIN FORECAST CONCERN WILL BE WIND CHILL HEADLINES. EARLY
MORNING SURFACE ANALYSIS SHOWS SURFACE HIGH PRESSURE STRETCHING
FROM EASTERN MONTANA INTO SOUTHEAST SOUTH DAKOTA. TEMPERATURES
EARLY THIS MORNING WERE IN THE SINGLE DIGITS AND TEENS BELOW ZERO
WITH WINDS OF 5 TO 10 MPH. THIS HAS DROPPED WIND CHILLS INTO
ADVISORY LEVELS ACROSS MUCH OF WESTERN AND CENTRAL NORTH
DAKOTA...THE EXCEPTION BEING FAR WEST CENTRAL NORTH DAKOTA WHERE
WINDS REMAIN WEAKEST.
THE FAR SOUTHWEST HAS ALSO SEEN AN INCREASE IN MID AND HIGH LEVEL
CLOUDS EARLY THIS MORNING HELPING TEMPERATURES GAIN A FEW DEGREES
OVER THE PAST COUPLE OF HOURS. NOT CONFIDENT THAT TREND WILL
CONTINUE SINCE THE LATEST HRRR SUGGESTS THE CLOUDS WILL SINK SOUTH
AGAIN THIS MORNING. OVERALL...THE WIND CHILL HEADLINE IS STILL
SUPPORTED BY THE LATEST OBSERVATIONS AND WILL NOT MAKE ANY CHANGES
TO IT.
WIND CHILLS WILL AGAIN BE THE MAIN CONCERN TONIGHT WITH LOWS OF 5
TO 15 BELOW AND WIND SPEEDS OF 10 MPH...INCREASING TO NEAR 20 MPH
OVERNIGHT. THIS AGAIN DROPS WIND CHILLS IN THE 25 TO 35 BELOW
RANGE ACROSS MUCH OF THE NORTH AND EAST. WILL KEEP THINGS SIMPLE
AND NOT ISSUE ADDITIONAL HEADLINES...BUT EXPECT LATER SHIFTS WILL
LIKELY NEED TO CONSIDER THAT POSSIBILITY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 308 AM CST TUE FEB 25 2014
THE MAIN HIGHLIGHTS FOR THE EXTENDED WILL BE THE WELL BELOW NORMAL
TEMPERATURES AND SNOW CHANCES THIS WEEKEND. MODELS ARE IN FAIRLY
GOOD AGREEMENT SO USED A BLEND FOR THIS PACKAGE.
WEDNESDAY STILL LOOKS TO BE THE WARMEST DAY OF THE WEEK WITH HIGHS
GENERALLY FROM THE TEENS EAST TO THE MID 20S SOUTHWEST.
HOWEVER...IT WILL ALSO BE THE WINDIEST DAY OF THE PERIOD AS HIGH
PRESSURE SURGES INTO THE REGION. SNOW FROM MONDAY`S EVENT COMBINED
WITH THESE WINDS SHOULD GENERATE PATCHY TO AREAS OF BLOWING
SNOW...MAINLY ON WEDNESDAY AFTERNOON. WINDS WILL DECREASE RAPIDLY
WEDNESDAY NIGHT AS HIGH PRESSURE SETTLES ACROSS THE REGION. COLD
AND DRY CONDITIONS WILL CONTINUE ACROSS THE REGION THURSDAY AS
HIGH PRESSURE SHIFTS EAST OF THE REGION.
BY FRIDAY...A REINFORCING COLD FRONT WILL PUSH THROUGH THE
NORTHERN PLAINS...WITH A BAROCLINIC ZONE SETTING UP OVER
SOUTHWESTERN NORTH DAKOTA. THIS WILL GENERATE A SLIGHT CHANCE FOR
SNOW OVER SOUTHWESTERN NORTH DAKOTA FRIDAY INTO FRIDAY NIGHT.
A SHORTWAVE ROTATING OVER THE NORTHERN ROCKIES AND INTO THE
NORTHERN PLAINS THIS WEEKEND IS PROGGED TO LIFT THE SNOW CHANCES
NORTH SATURDAY AND SUNDAY. HOWEVER...GIVEN THE WEAK UPPER LEVEL
FORCING...SNOW AMOUNTS ARE EXPECTED TO REMAIN FAIRLY LIGHT.
AS THE UPPER WAVE DEPARTS THE STATE MONDAY...DRY CONDITIONS ARE
EXPECTED BY THE BEGINNING OF THE NEXT WORK WEEK. COLD TEMPERATURE
ARE FORECAST TO CONTINUE AS WELL WITH HIGHS IN THE SINGLE DIGITS
ABOVE ZERO.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 637 AM CST TUE FEB 25 2014
EARLY MORNING SATELLITE IMAGERY SHOWS VFR CONDITIONS ACROSS NORTH
DAKOTA. WILL CARRY VFR AT ALL TERMINAL LOCATIONS...HOWEVER HAVE
SOME CONCERN CLOUDS COULD DEVELOP TODAY AS A BAND OF H925-H85
MOISTURE MOVES ACROSS NORTH DAKOTA. THE HRRR EVEN SUGGESTS THERE
IS SOME POTENTIAL FOR MVFR CEILINGS FROM LATE MORNING INTO THE
AFTERNOON ACROSS THE WEST...POSSIBLY IMPACTING WILLISTON AND
DICKINSON. HAVE FORECAST SCATTERED CLOUDS AROUND 3500 FT...BUT DID
NOT NOT CARRY A CEILING SINCE FORECAST SOUNDINGS SUGGEST ANY
AVAILABLE MOISTURE SHOULD BE SHALLOW. WINDS WILL START LIGHT...BUT
WILL INCREASE FROM FROM THE NORTHWEST LATER THIS MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM CST /9 AM MST/ THIS MORNING FOR
NDZ001>005-009>013-018>023-025-033>037-040>048-050-051.
&&
$$
UPDATE...TM
SHORT TERM...CK
LONG TERM...TM
AVIATION...CK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
308 AM CST TUE FEB 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 308 AM CST TUE FEB 25 2014
THE MAIN FORECAST CONCERN WILL BE WIND CHILL HEADLINES. EARLY
MORNING SURFACE ANALYSIS SHOWS SURFACE HIGH PRESSURE STRETCHING
FROM EASTERN MONTANA INTO SOUTHEAST SOUTH DAKOTA. TEMPERATURES
EARLY THIS MORNING WERE IN THE SINGLE DIGITS AND TEENS BELOW ZERO
WITH WINDS OF 5 TO 10 MPH. THIS HAS DROPPED WIND CHILLS INTO
ADVISORY LEVELS ACROSS MUCH OF WESTERN AND CENTRAL NORTH
DAKOTA...THE EXCEPTION BEING FAR WEST CENTRAL NORTH DAKOTA WHERE
WINDS REMAIN WEAKEST.
THE FAR SOUTHWEST HAS ALSO SEEN AN INCREASE IN MID AND HIGH LEVEL
CLOUDS EARLY THIS MORNING HELPING TEMPERATURES GAIN A FEW DEGREES
OVER THE PAST COUPLE OF HOURS. NOT CONFIDENT THAT TREND WILL
CONTINUE SINCE THE LATEST HRRR SUGGESTS THE CLOUDS WILL SINK SOUTH
AGAIN THIS MORNING. OVERALL...THE WIND CHILL HEADLINE IS STILL
SUPPORTED BY THE LATEST OBSERVATIONS AND WILL NOT MAKE ANY CHANGES
TO IT.
WIND CHILLS WILL AGAIN BE THE MAIN CONCERN TONIGHT WITH LOWS OF 5
TO 15 BELOW AND WIND SPEEDS OF 10 MPH...INCREASING TO NEAR 20 MPH
OVERNIGHT. THIS AGAIN DROPS WIND CHILLS IN THE 25 TO 35 BELOW
RANGE ACROSS MUCH OF THE NORTH AND EAST. WILL KEEP THINGS SIMPLE
AND NOT ISSUE ADDITIONAL HEADLINES...BUT EXPECT LATER SHIFTS WILL
LIKELY NEED TO CONSIDER THAT POSSIBILITY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 308 AM CST TUE FEB 25 2014
THE MAIN HIGHLIGHTS FOR THE EXTENDED WILL BE THE WELL BELOW NORMAL
TEMPERATURES AND SNOW CHANCES THIS WEEKEND. MODELS ARE IN FAIRLY
GOOD AGREEMENT SO USED A BLEND FOR THIS PACKAGE.
WEDNESDAY STILL LOOKS TO BE THE WARMEST DAY OF THE WEEK WITH HIGHS
GENERALLY FROM THE TEENS EAST TO THE MID 20S SOUTHWEST.
HOWEVER...IT WILL ALSO BE THE WINDIEST DAY OF THE PERIOD AS HIGH
PRESSURE SURGES INTO THE REGION. SNOW FROM MONDAY`S EVENT COMBINED
WITH THESE WINDS SHOULD GENERATE PATCHY TO AREAS OF BLOWING
SNOW...MAINLY ON WEDNESDAY AFTERNOON. WINDS WILL DECREASE RAPIDLY
WEDNESDAY NIGHT AS HIGH PRESSURE SETTLES ACROSS THE REGION. COLD
AND DRY CONDITIONS WILL CONTINUE ACROSS THE REGION THURSDAY AS
HIGH PRESSURE SHIFTS EAST OF THE REGION.
BY FRIDAY...A REINFORCING COLD FRONT WILL PUSH THROUGH THE
NORTHERN PLAINS...WITH A BAROCLINIC ZONE SETTING UP OVER
SOUTHWESTERN NORTH DAKOTA. THIS WILL GENERATE A SLIGHT CHANCE FOR
SNOW OVER SOUTHWESTERN NORTH DAKOTA FRIDAY INTO FRIDAY NIGHT.
A SHORTWAVE ROTATING OVER THE NORTHERN ROCKIES AND INTO THE
NORTHERN PLAINS THIS WEEKEND IS PROGGED TO LIFT THE SNOW CHANCES
NORTH SATURDAY AND SUNDAY. HOWEVER...GIVEN THE WEAK UPPER LEVEL
FORCING...SNOW AMOUNTS ARE EXPECTED TO REMAIN FAIRLY LIGHT.
AS THE UPPER WAVE DEPARTS THE STATE MONDAY...DRY CONDITIONS ARE
EXPECTED BY THE BEGINNING OF THE NEXT WORK WEEK. COLD TEMPERATURE
ARE FORECAST TO CONTINUE AS WELL WITH HIGHS IN THE SINGLE DIGITS
ABOVE ZERO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 308 AM CST TUE FEB 25 2014
EARLY MORNING SATELLITE IMAGERY SHOWS VFR CONDITIONS WITH MAINLY
CLEAR SKIES ACROSS THE TAF LOCATIONS. EXPECT VFR CONDITIONS TO
REMAIN IN PLACE...HOWEVER SCATTERED TO BROKEN CLOUDS AROUND 3500
FT ACROSS SOUTHERN SASKATCHEWAN / MANITOBA COULD MOVE INTO
NORTHERN AERODROMES BY 12Z...WORKING THEIR WAY SOUTH THROUGH THE
MORNING. WILL SHOW THE CLOUDS PROGRESSION ACROSS THE TAF
LOCATIONS...WITH MAINLY CLEAR SKIES PREVAILING ONCE THEY EXIT.
WINDS SHOULD BE LIGHT THIS MORNING...BUT WILL BECOME MORE STEADY
FROM THE NORTHWEST AFTER SUNRISE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM CST /9 AM MST/ THIS MORNING FOR
NDZ001>005-009>013-018>023-025-033>037-040>048-050-051.
&&
$$
SHORT TERM...CK
LONG TERM...TM
AVIATION...CK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1245 AM CST TUE FEB 25 2014
.UPDATE...
ISSUED AT 1245 AM CST TUE FEB 25 2014
EARLY MORNING SURFACE ANALYSIS SHOWED HIGH PRESSURE STRETCHING
FROM EASTERN MONTANA INTO CENTRAL SOUTH SOUTH DAKOTA. WINDS HAVE
BECOME LIGHT DUE TO THE PLACEMENT OF THE RIDGE AXIS...HOWEVER
DUE TO VERY COLD TEMPERATURES...WIND CHILLS ARE STILL REACHING
ADVISORY LEVELS. THE EXCEPTION REMAINS IN THE FAR WEST CENTRAL
PORTION OF THE STATE IN THE HEART OF THE RIDGE AXIS WHERE WINDS
ARE WEAKEST. DID NOT MAKE ANY ADJUSTMENTS TO THE WIND CHILL
ADVISORY SINCE IT STILL LOOKS APPROPRIATELY PLACED.
MADE MINOR ADJUSTMENTS TO CLOUDS OVERNIGHT WITH MID AND HIGH LEVEL
CLOUDS MOVING ACROSS SOUTHWEST NORTH DAKOTA. THIS IS PICKED UP
WELL BY THE LATEST HRRR WHICH SUGGESTS THINNING CLOUDS AGAIN AFTER
SUNRISE TUESDAY.
UPDATE ISSUED AT 829 PM CST MON FEB 24 2014
LATEST SURFACE ANALYSIS AND SATELLITE IMAGERY SHOWS GENERALLY
CLEAR SKIES ACROSS WESTERN AND CENTRAL NORTH DAKOTA. TEMPERATURES
ARE COOLING MUCH QUICKER ACROSS THE NORTHWEST WITH CROSBY ALREADY
AT 11 BELOW. UPSTREAM DEW POINTS NEAR 20 BELOW AND ADJUSTED MIN
TEMPERATURES IN THE UPPER TEENS BELOW ZERO OVERNIGHT FOR THE
NORTH. THIS RESULTED IN THE EXPANSION OF THE WIND CHILL
ADVISORY...NOW COVERING DIVIDE AND WILLIAMS COUNTIES. FARTHER
UPSTREAM...SCT/BKN CLOUDS AT 4000FT TO 5000FT IN CENTRAL
SASKATCHEWAN AND MANITOBA ARE SLIDING SOUTHEAST IN ASSOCIATION
WITH A WEAK SURFACE COLD FRONT AND AN H85 COLD POCKET. A LINEAR
EXTRAPOLATION WOULD PUT THIS AREA OF CLOUDS INTO OUR NORTHERN
ZONES BETWEEN 10Z AND 12Z TUESDAY. THIS MAY POSSIBLY WARM
TEMPERATURES ABOVE WIND CHILL ADVISORY CRITERIA AND WILL PASS THIS
ONTO THE MID SHIFT. ELSEWHERE...COOLED TEMPERATURES A FEW MORE
DEGREES OVERNIGHT WITH WIND CHILL ADVISORY TEMPERATURES SOLIDLY IN
PLACE EXCEPT IN THE FAR WEST. UPDATES TO THE TEXT PRODUCTS
FORTHCOMING.
UPDATE ISSUED AT 553 PM CST MON FEB 24 2014
THE LATEST WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH NOW INTO THE
JAMES RIVER VALLEY WITH THE TAIL END OF VERTICAL MOTION/LIGHT SNOW
OVER OAKES. THE CURRENT POP GRIDS HAVE THIS HANDLED WELL AS THE
PRECIPITATION WILL END WITHIN THE NEXT HOUR OR TWO. SKY CONDITION
IS TRENDING MOSTLY CLEAR UPSTREAM. AN H85 COLD POCKET/TROUGH
ASSOCIATED WITH -24C TEMPERATURES NORTH OF MANITOBA WILL SAG SOUTH
INTO NORTHERN NORTH DAKOTA AFTER MIDNIGHT...AND INTO SOUTH CENTRAL
BY MID TUESDAY MORNING. LAPSE RATES IN THE 925MB-H85 LAYER ARE
WEAK...BUT TIME HEIGHT/RH CROSS SECTIONS SHOW A BRIEF PERIOD/3 HRS
OF PARTLY CLOUDY TO MOSTLY CLOUDY CONDITIONS TUESDAY MORNING.
UPSTREAM OBS IN CENTRAL SASKATCHEWAN AND MANITOBA CONFIRM THIS.
THE CURRENT WIND CHILL ADVISORY IS ON TRACK AND WILL MONITOR THIS
EVENING...BUT NOT EXPECTING ANY SIGNIFICANT CHANGES TO CURRENT
FORECAST.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 307 PM CST MON FEB 24 2014
MAIN FORECAST ISSUES ARE LIGHT SNOW AFFECTING THE SOUTHEAST
THROUGH LATE AFTERNOON AND CONTINUED COLD CONDITIONS OVERNIGHT. WV
IMAGERY SHOWED SHORTWAVE IN NORTHWEST FLOW MOVING ACROSS ND THIS
AFTERNOON WITH WEAK INVERTED SURFACE TROUGH NUDGING INTO
SOUTH CENTRAL ND SUPPORTING AREA OF LIGHT SNOW. VIS IMAGERY SHOWS
BACK EDGE OF CLOUD COVER STEADILY PROGRESSING SOUTHEASTWARD WITH
CLEAR SKIES NOW OVER MUCH OF WESTERN AND NORTHERN ND.
ANY LINGERING SNOW SHOULD QUICKLY DEPART THE SOUTHEAST BY EARLY
EVENING. ACCUMULATIONS HAVE BEEN LIGHT...GENERALLY LESS THAN AN
INCH DESPITE SURFACE OBS SHOWING VISIBILITY DOWN TO A MILE FOR
SEVERAL HOURS. TONIGHT...SURFACE RIDGE BUILDS IN FROM THE
NORTHWEST WITH SURFACE WINDS MOST AREAS 10 TO 15 MPH...A LITTLE
LIGHTER ACROSS THE WEST. WIND CHILL VALUES MOST AREAS FALL INTO
THE ADVISORY CATEGORY...SO HAVE ISSUED A WIND CHILL ADVISORY FOR
ALL BUT WEST CENTRAL AND NORTHWEST SECTIONS.
DRY AND COLD CONDITIONS CONTINUE ON TUESDAY AS SURFACE HIGH CENTER
SINKS TO EASTERN MONTANA/WESTERN ND DURING THE DAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 307 PM CST MON FEB 24 2014
THE MAIN FORECAST ISSUES DURING THE LONG TERM PERIOD ARE
TEMPERATURES AND WIND CHILLS...WITH THE EXCEPTION OF A WARMER AND
WINDIER DAY ON WEDNESDAY.
ON TUESDAY NIGHT AN ARCTIC HIGH PRESSURE DOME WILL BE EXITING THE
AREA TO THE SOUTHEAST AS A CLIPPER LOW PRESSURE SYSTEM NEAR HUDSON
BAY DROPS SOUTHEAST QUICKLY...DRAGGING A COLD FRONT SOUTH ACROSS
NORTH DAKOTA DURING THE DAYTIME WEDNESDAY. AHEAD OF THE COLD
FRONT...SOUTHWEST WINDS WILL INCREASE AND ALLOW SOME WARM ADVECTION
INTO THE STATE. TEMPERATURES SHOULD BE ABLE TO RECOVER TO NEAR 10
ABOVE IN THE TURTLE MOUNTAINS...REACH THE TEENS ALONG AND EAST OF
THE MISSOURI RIVER...AND MAKE IT INTO THE 20S SOUTH AND WEST OF THE
MISSOURI RIVER. THE SOUTHWEST WINDS WILL INCREASE AND BECOME
NORTHWEST AT 15 TO 25 MPH SOUTHWEST - AND NORTHWEST AT 25 TO 30 MPH
IN CENTRAL NORTH DAKOTA. BLOWING SNOW MAY BE AN ISSUE WEDNESDAY
AFTERNOON FROM THE TURTLE MOUNTAINS THROUGH THE JAMES RIVER BASIN.
WITH THE EXCEPTION OF THE BRIEF WARM-UP ON WEDNESDAY...TEMPERATURES
WILL REMAIN WELL BELOW NORMAL THROUGH THE PERIOD AS A LARGE UPPER
TROUGH CONTINUES TO PROVIDE A STEADY STREAM OF ARCTIC AIR INTO NORTH
DAKOTA. CONSIDERING WINDS AND OVERNIGHT/EARLY MORNING
TEMPERATURES...SATURDAY MORNING AND SUNDAY MORNING ARE STILL
FORECAST TO BE THE COLDEST PERIODS...WITH WIND CHILLS OF 40 BELOW OR
COLDER ACROSS THE NORTHERN COUNTIES. WIND CHILL HEADLINES WILL
LIKELY BE NEEDED OTHER DAYS AS WELL.
SNOW CHANCES THROUGH MOST OF THE PERIOD WILL BE LOW...WITH THE
EXCEPTION OF SATURDAY NIGHT IN THE FAR SOUTHWEST AND SOUTH
CENTRAL...WHERE SOME LIGHT AMOUNTS ARE POSSIBLE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1245 AM CST TUE FEB 25 2014
EARLY MORNING SATELLITE IMAGERY SHOWS VFR CONDITIONS WITH MAINLY
CLEAR SKIES ACROSS THE TAF LOCATIONS. GENERALLY EXPECT VFR
CONDITIONS TO REMAIN IN PLACE...HOWEVER SCATTERED TO BROKEN
CLOUDS AROUND 3500 FT ACROSS SOUTHERN SASKATCHEWAN / MANITOBA WILL
MOVE INTO NORTHERN AERODROMES BY 12Z...WORKING THEIR WAY SOUTH
THROUGH THE MORNING. WILL SHOW THE CLOUDS PROGRESSION ACROSS THE
TAF LOCATIONS...WITH MAINLY CLEAR SKIES PREVAILING ONCE THEY EXIT.
WINDS SHOULD BE LIGHT THIS MORNING...BUT WILL BECOME MORE STEADY
FROM THE NORTHWEST AFTER SUNRISE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM CST /9 AM MST/ THIS MORNING FOR
NDZ001>005-009>013-018>023-025-033>037-040>048-050-051.
&&
$$
UPDATE...CK
SHORT TERM...JNS
LONG TERM...JV
AVIATION...CK
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
855 AM EST TUE FEB 25 2014
.SYNOPSIS...
UPPER LEVEL DISTURBANCE CROSSES FIRST THING THIS MORNING. ARCTIC
FRONTS CROSS TONIGHT AND THURSDAY. WEAK LOW PRESSURE CROSSES ON
SATURDAY. A STRONGER LOW PRESSURE SYSTEM APPROACHES ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
945 AM UPDATE...
OVERACHIEVER THIS MORNING WITH NUMEROUS 2 INCH REPORTS WITH
NUMEROUS ACCIDENTS ACROSS SE OH AND N WV. ISSUED A WINTER WX
ADVISORY FOR 1 TO 3 INCHES OF SNOW AND HIGH IMPACT TO TRAVEL GIVEN
MORNING COMMUTE. SOME LOCAL HIGHER AMOUNTS DEFINITELY POSSIBLE
ALONG US 33 ROUTE AND ALONG I79 CORRIDOR. ISSUED SPS I64 COUNTIES
IN NE KY/C WV FOR UP TO AN INCH JUST N OF I64 CORRIDOR. NEAR TERM
MODELS HAVE LOW BALLED THE QPF COMPARED TO WHAT HAS ACTUALLY OCCUR
ED. THEY ALSO HAVE NOT BEEN FAR ENOUGH S WITH TRACK OF THIS BAND
OF SN. HOPING THIS TRACKS MORE E THAN S NEXT HR TO KEEP IT OUT OF
HTS AND CRW. ALL OF THIS SHOULD TAPER OFF BY 16Z.
PREV DISCN...
UPPER LEVEL SYSTEM IMPACTING NRN PORTION OF THE AREA EARLY THIS
MORNING AS RR ENTRANCE REGION OF JET AND FRONTOGENETIC FORCING CROSS
IN THE BAROCLINIC ZONE AROUND 12Z. AREA RADAR SHOWED THAT
PRECIPITATION WAS NOT YET REACHING THE GROUND SAVE FOR THE HIGHER
TERRAIN OF NRN WV. THIS SHOULD CHANGE TOWARD DAWN AS LOW LEVELS
EVENTUALLY MOISTEN.
WITH THE DRY AIR AT THE START...AND THE FAST PACE OF THE MI AND
UPPER LEVEL SYSTEM...AMNTS WILL BE LIMITED...MAINTAINED PREVIOUS
FCST OF LESS THAN AN INCH NRN LOWLANDS...1-2 INCHES IN THE NRN WV
MOUNTAINS WHERE THE SNOW WAS ALREADY REACHING THE GROUND.
ARCTIC FRONT DRIVEN BY UPPER LEVEL S/W TROUGH AND A MUCH MORE STOUT
JET MAX...CROSSES TONIGHT. UPSLOPE SNOW WILL SET UP OVERNIGHT IN
THE COLD ADVECTION BEHIND THE FRONT. FRONTOGENETIC FORCING EARLY ON
MAY GENERATE AN AREA OF SNOW UPSTREAM THAT MOVES INTO SRN PORTIONS
OF THE FCST AREA FROM THE W. IF THE POTENTIAL FOR THIS FEATURE TO
PRODUCE ACCUMULATING SNOW INCREASES...THEN AN ADVISORY FOR SNOW MAY
BE NEEDED FOR THE SRN LOWLANDS. HWO MENTION CONTINUES. THX JKL AND
MRX FOR COORD ON THIS.
BLENDED IN MET FOR HIGHS TODAY AND BIAS CORRECTED MET FOR LOWS
TONIGHT...CONTINUING THE COLDER TREND. SLOWED FALL OF TEMPERATURES
TONIGHT UNTIL LATER AS THE FRONT GOES BY.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
TRANSITION TO A QUIETER...BUT MUCH COLDER PATTERN IN THE SHORT TERM.
INITIAL COLD FRONT PUSHING EAST THROUGH CWA AT BEGINNING OF
PERIOD...WITH LIGHT SNOW SHOWERS LINGERING...MAINLY ACROSS MOUNTAIN
ZONES FOR REMAINDER OF DAY WEDNESDAY...WITH ONLY LIGHT ADDITIONAL
ACCUMULATIONS EXPECTED. THIS WILL BE THE FIRST SHOT OF COLD
AIR...WITH 850MB TEMPS DIPPING TO AROUND -16C THURSDAY MORNING. MADE
LITTLE CHANGES TO PREVIOUS LOW TEMPERATURE FORECAST THURSDAY
MORNING...WHICH PLACES MANY LOWLAND COUNTIES IN THE LOWER
TEENS...AND SINGLE DIGITS TO BELOW ZERO ACROSS THE MOUNTAINS. A
SECONDARY FRONTAL BOUNDARY WILL PUSH ACROSS THE AREA ON THURSDAY.
BULK OF PRECIPITATION WILL REMAIN TO THE NORTH OF THE CWA...ALTHOUGH
NORTHERN ZONES COULD SEE A FEW FLURRIES WITH PASSAGE. WITH FRONTAL
PASSAGE...MUCH COLDER AIR WILL MOVE INTO THE AREA...WITH 850MB TEMPS
DIPPING DOWN TO AROUND -22C. AS A RESULT...ELECTED TO LOWER
TEMPERATURES SIGNIFICANTLY FRIDAY MORNING FROM PREVIOUS
FORECAST...PLACING MANY MOUNTAINOUS LOCATIONS BELOW ZERO...WITH
SINGLE DIGITS ACROSS THE LOWLANDS...CONSIDERING COLDER AIR
MASS...ALONG WITH FAVORABLE RADIATIONAL COOLING CONDITIONS.
WITH THE COLDER AIR IN PLACE...NORTHERN MOUNTAIN ZONES MAY NEED WIND
CHILL HEADLINES BOTH THURSDAY AND FRIDAY MORNINGS. AT THIS
POINT...DOESNT APPEAR TO BE NECESSARY ACROSS LOWLANDS. WILL CONTINUE
TO HIGHLIGHT IN THE HWO.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH PRESSURE WILL BE IN CONTROL THURSDAY NIGHT INTO FRIDAY WITH DRY
AND COOL CONDITIONS.
MODELS BRING A MID LEVEL SHORTWAVE EMBEDDED IN THE SOUTHERN STREAM
FRIDAY NIGHT INTO SATURDAY. ADJUSTED CHANCE POPS ACROSS THE AREA
WITH THIS FEATURE. WITH THE GFS AND ECMWF SHOWING FREEZING LINE AT
H85 ACROSS AND SOUTH OF OUR CWA...WONT BE SURPRISED TO SEE PCPN
FALLING AS SNOW. THIS SHORTWAVE EXITS SATURDAY WITH LINGERING SNOW
SHOWERS OVER THE EASTERN MOUNTAINS THROUGH AT LEAST SATURDAY
AFTERNOON.
BROAD SURFACE HIGH PRESSURE BUILD FROM THE UPPER CENTRAL
PLAINS...SOUTHEAST ACROSS THE OH VALLEY INTO WV SATURDAY NIGHT INTO
SUNDAY. WITH ZONAL FLOW EXPECTED ALOFT...THE AREA SHOULD STAY
RELATIVELY DRY SATURDAY NIGHT INTO SUNDAY.
THE FORECAST CHALLENGE ARRIVE WITH THE NEXT LOW PRESSURE SYSTEM.
BOTH THE GFS AND ECMWF BRING A SURFACE LOW PRESSURE CROSSING OUR CWA
DIAGONALLY FROM SOUTHWEST TO NORTHEAST SUNDAY OR MONDAY. THE PROBLEM
IS THAT THE ECMWF IS ABOUT 24 HOURS FASTER THAN THE GFS. TRIED TO
COMPROMISE IN BETWEEN BOTH SOLUTION IN TERMS OF POPS. EITHER
WAY...STRONG SOUTHWEST FLOW IS EXPECTED AHEAD OF THE LOW TO BRING
WARM AIR ADVECTION AND STRONG GUSTY WINDS. BOTH MODELS INDICATE 60
TO 70 KNOTS AT H85. AS MANY SPRING LOW SYSTEMS BRINGING STRONG
SOUTHWEST FLOW...EXPECT WARMER THAN GUIDANCE TEMPERATURES WITH THIS
SYSTEM. WENT WITH HPC WHICH IS WARMER THAN ALL AVAILABLE GUIDANCE
WITH THIS LOW. IN TERMS OF POPS...LEANED TOWARDS THE GFS SLOWER
SOLUTION AND INTRODUCED LIKELY POPS ON MONDAY.
TWEAKED HPC GUIDANCE FOR TEMPERATURES THROUGH THE PERIOD.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
AN UPPER LEVEL SYSTEM WAS BRINGING SNOW FROM THE MIDDLE OHIO VALLEY
EWD TO THE NORTHERN WV MOUNTAINS...AFFECTING THE NORTHERN 3 TAF
SITES...EARLY THIS MORNING. SNOW WILL CONTINUE TO BRING IFR VSBY AT
TIMES THIS MORNING. EXPECT 3-4 HOURS OF IFR VSBY IN SNOW...EXCEPT
UP TO 6 HRS EKN...IMPROVING TO MVFR AROUND 18Z TODAY THERE. EXPECT
MAINLY MVFR CIGS ALTHOUGH BRIEF IFR CIGS ARE POSSIBLE. FARTHER
S...EXPECT VFR WITH STRATOCU 4-5 KFT.
RETURN TO VFR N SHOULD BE AROUND MIDDAY...EXCEPT EKN...WHERE
IMPROVEMENT TO VFR VSBY TAKES UNTIL AROUND 20Z TODAY...MVFR STRATOCU
MAY HANG ON THERE THROUGHOUT THE TAF PERIOD. FARTHER S...STRATOCU
VANISHES LATER THIS AFTERNOON BUT RETURNS LATE TONIGHT...AS AN
ARCTIC FRONT ARRIVES FROM THE NW. THIS SHOULD RESULT IN MVFR IN
SNOW ALL SITES E OF THE OHIO RIVER BY DAWN WED...EVEN IFR AT BKW.
LIGHT W TO NW SFC FLOW BECOMES A BIT GUSTY DURING THE DAY
TODAY...BEFORE DIMINISHING A BIT THIS EVENING. SFC FLOW WILL
INCREASE AGAIN BEHIND THE COLD FRONT OVERNIGHT TONIGHT. LIGHT TO
MODERATE W FLOW ALOFT BECOMES LIGHT W TUE AFTERNOON...AND THEN
BEGINS TO STRENGTHEN FROM THE NW OVERNIGHT TONIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF LIGHT SNOW AND ASSOCIATED
CATEGORY CHANGES MAY VARY. IFR CIGS COULD NOT BE RULED OUT N THIS
MORNING. EKN CIGS MAY IMPROVE TO VFR FOR A TIME THIS EVENING.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EST 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY M M M M M M H H H H H H
PKB CONSISTENCY L L H H H H H H H H H H
CKB CONSISTENCY H H L H L H H H H H H H
AFTER 12Z WEDNESDAY...
BRIEF IFR POSSIBLE INTO EARLY WEDNESDAY IN SNOW BEHIND AN ARCTIC
FRONT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
WVZ007>011-016>020-028>032-038>040-046-047.
OH...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
OHZ075-076-083>087.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/SL
NEAR TERM...TRM/30
SHORT TERM...SL
LONG TERM...ARJ
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
555 AM EST TUE FEB 25 2014
.SYNOPSIS...
UPPER LEVEL DISTURBANCE CROSSES FIRST THING THIS MORNING. ARCTIC
FRONTS CROSS TONIGHT AND THURSDAY. WEAK LOW PRESSURE CROSSES ON
SATURDAY. A STRONGER LOW PRESSURE SYSTEM APPROACHES ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
545 AM UPDATE...
ADJUSTED POPS SLIGHTLY SWD / EARLIER AND HAVE SLIGHTLY HIGHER SNOW
AMNTS THIS MORNING. GILMER CO SCHOOLS REPORTED A COATING AT 415
AM. FCST OTHERWISE ON TRACK.
PREV DISCN...
UPPER LEVEL SYSTEM IMPACTING NRN PORTION OF THE AREA EARLY THIS
MORNING AS RR ENTRANCE REGION OF JET AND FRONTOGENETIC FORCING CROSS
IN THE BAROCLINIC ZONE AROUND 12Z. AREA RADAR SHOWED THAT
PRECIPITATION WAS NOT YET REACHING THE GROUND SAVE FOR THE HIGHER
TERRAIN OF NRN WV. THIS SHOULD CHANGE TOWARD DAWN AS LOW LEVELS
EVENTUALLY MOISTEN.
WITH THE DRY AIR AT THE START...AND THE FAST PACE OF THE MI AND
UPPER LEVEL SYSTEM...AMNTS WILL BE LIMITED...MAINTAINED PREVIOUS
FCST OF LESS THAN AN INCH NRN LOWLANDS...1-2 INCHES IN THE NRN WV
MOUNTAINS WHERE THE SNOW WAS ALREADY REACHING THE GROUND.
ARCTIC FRONT DRIVEN BY UPPER LEVEL S/W TROUGH AND A MUCH MORE STOUT
JET MAX...CROSSES TONIGHT. UPSLOPE SNOW WILL SET UP OVERNIGHT IN
THE COLD ADVECTION BEHIND THE FRONT. FRONTOGENETIC FORCING EARLY ON
MAY GENERATE AN AREA OF SNOW UPSTREAM THAT MOVES INTO SRN PORTIONS
OF THE FCST AREA FROM THE W. IF THE POTENTIAL FOR THIS FEATURE TO
PRODUCE ACCUMULATING SNOW INCREASES...THEN AN ADVISORY FOR SNOW MAY
BE NEEDED FOR THE SRN LOWLANDS. HWO MENTION CONTINUES. THX JKL AND
MRX FOR COORD ON THIS.
BLENDED IN MET FOR HIGHS TODAY AND BIAS CORRECTED MET FOR LOWS
TONIGHT...CONTINUING THE COLDER TREND. SLOWED FALL OF TEMPERATURES
TONIGHT UNTIL LATER AS THE FRONT GOES BY.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
TRANSITION TO A QUIETER...BUT MUCH COLDER PATTERN IN THE SHORT TERM.
INITIAL COLD FRONT PUSHING EAST THROUGH CWA AT BEGINNING OF
PERIOD...WITH LIGHT SNOW SHOWERS LINGERING...MAINLY ACROSS MOUNTAIN
ZONES FOR REMAINDER OF DAY WEDNESDAY...WITH ONLY LIGHT ADDITIONAL
ACCUMULATIONS EXPECTED. THIS WILL BE THE FIRST SHOT OF COLD
AIR...WITH 850MB TEMPS DIPPING TO AROUND -16C THURSDAY MORNING. MADE
LITTLE CHANGES TO PREVIOUS LOW TEMPERATURE FORECAST THURSDAY
MORNING...WHICH PLACES MANY LOWLAND COUNTIES IN THE LOWER
TEENS...AND SINGLE DIGITS TO BELOW ZERO ACROSS THE MOUNTAINS. A
SECONDARY FRONTAL BOUNDARY WILL PUSH ACROSS THE AREA ON THURSDAY.
BULK OF PRECIPITATION WILL REMAIN TO THE NORTH OF THE CWA...ALTHOUGH
NORTHERN ZONES COULD SEE A FEW FLURRIES WITH PASSAGE. WITH FRONTAL
PASSAGE...MUCH COLDER AIR WILL MOVE INTO THE AREA...WITH 850MB TEMPS
DIPPING DOWN TO AROUND -22C. AS A RESULT...ELECTED TO LOWER
TEMPERATURES SIGNIFICANTLY FRIDAY MORNING FROM PREVIOUS
FORECAST...PLACING MANY MOUNTAINOUS LOCATIONS BELOW ZERO...WITH
SINGLE DIGITS ACROSS THE LOWLANDS...CONSIDERING COLDER AIR
MASS...ALONG WITH FAVORABLE RADIATIONAL COOLING CONDITIONS.
WITH THE COLDER AIR IN PLACE...NORTHERN MOUNTAIN ZONES MAY NEED WIND
CHILL HEADLINES BOTH THURSDAY AND FRIDAY MORNINGS. AT THIS
POINT...DOESNT APPEAR TO BE NECESSARY ACROSS LOWLANDS. WILL CONTINUE
TO HIGHLIGHT IN THE HWO.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH PRESSURE WILL BE IN CONTROL THURSDAY NIGHT INTO FRIDAY WITH DRY
AND COOL CONDITIONS.
MODELS BRING A MID LEVEL SHORTWAVE EMBEDDED IN THE SOUTHERN STREAM
FRIDAY NIGHT INTO SATURDAY. ADJUSTED CHANCE POPS ACROSS THE AREA
WITH THIS FEATURE. WITH THE GFS AND ECMWF SHOWING FREEZING LINE AT
H85 ACROSS AND SOUTH OF OUR CWA...WONT BE SURPRISED TO SEE PCPN
FALLING AS SNOW. THIS SHORTWAVE EXITS SATURDAY WITH LINGERING SNOW
SHOWERS OVER THE EASTERN MOUNTAINS THROUGH AT LEAST SATURDAY
AFTERNOON.
BROAD SURFACE HIGH PRESSURE BUILD FROM THE UPPER CENTRAL
PLAINS...SOUTHEAST ACROSS THE OH VALLEY INTO WV SATURDAY NIGHT INTO
SUNDAY. WITH ZONAL FLOW EXPECTED ALOFT...THE AREA SHOULD STAY
RELATIVELY DRY SATURDAY NIGHT INTO SUNDAY.
THE FORECAST CHALLENGE ARRIVE WITH THE NEXT LOW PRESSURE SYSTEM.
BOTH THE GFS AND ECMWF BRING A SURFACE LOW PRESSURE CROSSING OUR CWA
DIAGONALLY FROM SOUTHWEST TO NORTHEAST SUNDAY OR MONDAY. THE PROBLEM
IS THAT THE ECMWF IS ABOUT 24 HOURS FASTER THAN THE GFS. TRIED TO
COMPROMISE IN BETWEEN BOTH SOLUTION IN TERMS OF POPS. EITHER
WAY...STRONG SOUTHWEST FLOW IS EXPECTED AHEAD OF THE LOW TO BRING
WARM AIR ADVECTION AND STRONG GUSTY WINDS. BOTH MODELS INDICATE 60
TO 70 KNOTS AT H85. AS MANY SPRING LOW SYSTEMS BRINGING STRONG
SOUTHWEST FLOW...EXPECT WARMER THAN GUIDANCE TEMPERATURES WITH THIS
SYSTEM. WENT WITH HPC WHICH IS WARMER THAN ALL AVAILABLE GUIDANCE
WITH THIS LOW. IN TERMS OF POPS...LEANED TOWARDS THE GFS SLOWER
SOLUTION AND INTRODUCED LIKELY POPS ON MONDAY.
TWEAKED HPC GUIDANCE FOR TEMPERATURES THROUGH THE PERIOD.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AN UPPER LEVEL SYSTEM WAS BRINGING SNOW FROM THE MIDDLE OHIO VALLEY
EWD TO THE NORTHERN WV MOUNTAINS...AFFECTING THE NORTHERN 3 TAF
SITES...EARLY THIS MORNING. SNOW WILL CONTINUE TO BRING IFR VSBY AT
TIMES THIS MORNING. EXPECT 3-4 HOURS OF IFR VSBY IN SNOW...EXCEPT
UP TO 6 HRS EKN...IMPROVING TO MVFR AROUND 18Z TODAY THERE. EXPECT
MAINLY MVFR CIGS ALTHOUGH BRIEF IFR CIGS ARE POSSIBLE. FARTHER
S...EXPECT VFR WITH STRATOCU 4-5 KFT.
RETURN TO VFR N SHOULD BE AROUND MIDDAY...EXCEPT EKN...WHERE
IMPROVEMENT TO VFR VSBY TAKES UNTIL AROUND 20Z TODAY...MVFR STRATOCU
MAY HANG ON THERE THROUGHOUT THE TAF PERIOD. FARTHER S...STRATOCU
VANISHES LATER THIS AFTERNOON BUT RETURNS LATE TONIGHT...AS AN
ARCTIC FRONT ARRIVES FROM THE NW. THIS SHOULD RESULT IN MVFR IN
SNOW ALL SITES E OF THE OHIO RIVER BY DAWN WED...EVEN IFR AT BKW.
LIGHT W TO NW SFC FLOW BECOMES A BIT GUSTY DURING THE DAY
TODAY...BEFORE DIMINISHING A BIT THIS EVENING. SFC FLOW WILL
INCREASE AGAIN BEHIND THE COLD FRONT OVERNIGHT TONIGHT. LIGHT TO
MODERATE W FLOW ALOFT BECOMES LIGHT W TUE AFTERNOON...AND THEN
BEGINS TO STRENGTHEN FROM THE NW OVERNIGHT TONIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF LIGHT SNOW AND ASSOCIATED
CATEGORY CHANGES MAY VARY. IFR CIGS COULD NOT BE RULED OUT N THIS
MORNING. EKN CIGS MAY IMPROVE TO VFR FOR A TIME THIS EVENING.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY M M L M M M M M M H H H
PKB CONSISTENCY M M M L L M H H H H H H
CKB CONSISTENCY M M M M M L M L H H H H
AFTER 12Z WEDNESDAY...
BRIEF IFR POSSIBLE INTO EARLY WEDNESDAY IN SNOW BEHIND AN ARCTIC
FRONT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/SL
NEAR TERM...TRM
SHORT TERM...SL
LONG TERM...ARJ
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
352 AM EST TUE FEB 25 2014
.SYNOPSIS...
UPPER LEVEL DISTURBANCE CROSSES FIRST THING THIS MORNING. ARCTIC
FRONTS CROSS TONIGHT AND THURSDAY. WEAK LOW PRESSURE CROSSES ON
SATURDAY. A STRONGER LOW PRESSURE SYSTEM APPROACHES ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPPER LEVEL SYSTEM IMPACTING NRN PORTION OF THE AREA EARLY THIS
MORNING AS RR ENTRANCE REGION OF JET AND FRONTOGENETIC FORCING CROSS
IN THE BAROCLINIC ZONE AROUND 12Z. AREA RADAR SHOWED THAT
PRECIPITATION WAS NOT YET REACHING THE GROUND SAVE FOR THE HIGHER
TERRAIN OF NRN WV. THIS SHOULD CHANGE TOWARD DAWN AS LOW LEVELS
EVENTUALLY MOISTEN.
WITH THE DRY AIR AT THE START...AND THE FAST PACE OF THE MI AND
UPPER LEVEL SYSTEM...AMNTS WILL BE LIMITED...MAINTAINED PREVIOUS
FCST OF LESS THAN AN INCH NRN LOWLANDS...1-2 INCHES IN THE NRN WV
MOUNTAINS WHERE THE SNOW WAS ALREADY REACHING THE GROUND.
ARCTIC FRONT DRIVEN BY UPPER LEVEL S/W TROUGH AND A MUCH MORE STOUT
JET MAX...CROSSES TONIGHT. UPSLOPE SNOW WILL SET UP OVERNIGHT IN
THE COLD ADVECTION BEHIND THE FRONT. FRONTOGENETIC FORCING EARLY ON
MAY GENERATE AN AREA OF SNOW UPSTREAM THAT MOVES INTO SRN PORTIONS
OF THE FCST AREA FROM THE W. IF THE POTENTIAL FOR THIS FEATURE TO
PRODUCE ACCUMULATING SNOW INCREASES...THEN AN ADVISORY FOR SNOW MAY
BE NEEDED FOR THE SRN LOWLANDS. HWO MENTION CONTINUES. THX JKL AND
MRX FOR COORD ON THIS.
BLENDED IN MET FOR HIGHS TODAY AND BIAS CORRECTED MET FOR LOWS
TONIGHT...CONTINUING THE COLDER TREND. SLOWED FALL OF TEMPERATURES
TONIGHT UNTIL LATER AS THE FRONT GOES BY.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
TRANSITION TO A QUIETER...BUT MUCH COLDER PATTERN IN THE SHORT TERM.
INITIAL COLD FRONT PUSHING EAST THROUGH CWA AT BEGINNING OF
PERIOD...WITH LIGHT SNOW SHOWERS LINGERING...MAINLY ACROSS MOUNTAIN
ZONES FOR REMAINDER OF DAY WEDNESDAY...WITH ONLY LIGHT ADDITIONAL
ACCUMULATIONS EXPECTED. THIS WILL BE THE FIRST SHOT OF COLD
AIR...WITH 850MB TEMPS DIPPING TO AROUND -16C THURSDAY MORNING. MADE
LITTLE CHANGES TO PREVIOUS LOW TEMPERATURE FORECAST THURSDAY
MORNING...WHICH PLACES MANY LOWLAND COUNTIES IN THE LOWER
TEENS...AND SINGLE DIGITS TO BELOW ZERO ACROSS THE MOUNTAINS. A
SECONDARY FRONTAL BOUNDARY WILL PUSH ACROSS THE AREA ON THURSDAY.
BULK OF PRECIPITATION WILL REMAIN TO THE NORTH OF THE CWA...ALTHOUGH
NORTHERN ZONES COULD SEE A FEW FLURRIES WITH PASSAGE. WITH FRONTAL
PASSAGE...MUCH COLDER AIR WILL MOVE INTO THE AREA...WITH 850MB TEMPS
DIPPING DOWN TO AROUND -22C. AS A RESULT...ELECTED TO LOWER
TEMPERATURES SIGNIFICANTLY FRIDAY MORNING FROM PREVIOUS
FORECAST...PLACING MANY MOUNTAINOUS LOCATIONS BELOW ZERO...WITH
SINGLE DIGITS ACROSS THE LOWLANDS...CONSIDERING COLDER AIR
MASS...ALONG WITH FAVORABLE RADIATIONAL COOLING CONDITIONS.
WITH THE COLDER AIR IN PLACE...NORTHERN MOUNTAIN ZONES MAY NEED WIND
CHILL HEADLINES BOTH THURSDAY AND FRIDAY MORNINGS. AT THIS
POINT...DOESNT APPEAR TO BE NECESSARY ACROSS LOWLANDS. WILL CONTINUE
TO HIGHLIGHT IN THE HWO.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH PRESSURE WILL BE IN CONTROL THURSDAY NIGHT INTO FRIDAY WITH DRY
AND COOL CONDITIONS.
MODELS BRING A MID LEVEL SHORTWAVE EMBEDDED IN THE SOUTHERN STREAM
FRIDAY NIGHT INTO SATURDAY. ADJUSTED CHANCE POPS ACROSS THE AREA
WITH THIS FEATURE. WITH THE GFS AND ECMWF SHOWING FREEZING LINE AT
H85 ACROSS AND SOUTH OF OUR CWA...WONT BE SURPRISED TO SEE PCPN
FALLING AS SNOW. THIS SHORTWAVE EXITS SATURDAY WITH LINGERING SNOW
SHOWERS OVER THE EASTERN MOUNTAINS THROUGH AT LEAST SATURDAY
AFTERNOON.
BROAD SURFACE HIGH PRESSURE BUILD FROM THE UPPER CENTRAL
PLAINS...SOUTHEAST ACROSS THE OH VALLEY INTO WV SATURDAY NIGHT INTO
SUNDAY. WITH ZONAL FLOW EXPECTED ALOFT...THE AREA SHOULD STAY
RELATIVELY DRY SATURDAY NIGHT INTO SUNDAY.
THE FORECAST CHALLENGE ARRIVE WITH THE NEXT LOW PRESSURE SYSTEM.
BOTH THE GFS AND ECMWF BRING A SURFACE LOW PRESSURE CROSSING OUR CWA
DIAGONALLY FROM SOUTHWEST TO NORTHEAST SUNDAY OR MONDAY. THE PROBLEM
IS THAT THE ECMWF IS ABOUT 24 HOURS FASTER THAN THE GFS. TRIED TO
COMPROMISE IN BETWEEN BOTH SOLUTION IN TERMS OF POPS. EITHER
WAY...STRONG SOUTHWEST FLOW IS EXPECTED AHEAD OF THE LOW TO BRING
WARM AIR ADVECTION AND STRONG GUSTY WINDS. BOTH MODELS INDICATE 60
TO 70 KNOTS AT H85. AS MANY SPRING LOW SYSTEMS BRINGING STRONG
SOUTHWEST FLOW...EXPECT WARMER THAN GUIDANCE TEMPERATURES WITH THIS
SYSTEM. WENT WITH HPC WHICH IS WARMER THAN ALL AVAILABLE GUIDANCE
WITH THIS LOW. IN TERMS OF POPS...LEANED TOWARDS THE GFS SLOWER
SOLUTION AND INTRODUCED LIKELY POPS ON MONDAY.
TWEAKED HPC GUIDANCE FOR TEMPERATURES THROUGH THE PERIOD.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
AN UPPER LEVEL SYSTEM WILL BRING SNOW FROM THE MIDDLE OHIO VALLEY
EWD TO THE NORTHERN WV MOUNTAINS...AFFECTING THE NORTHERN 3 TAF
SITES EARLY TUE MORNING. SNOW IS LIKELY TO BRING IFR VSBY BEGINNING
NEAR 12Z TUE...A LITTLE EARLIER PKB AND A LITTLE LATER EKN. EXPECT
3-4 HOURS OF IFR VSBY IN SNOW...EXCEPT UP TO 6 HRS EKN...IMPROVING
TO MVFR AROUND 18Z TUE THERE. EXPECT MAINLY MVFR CIGS ALTHOUGH
BRIEF IFR CIGS ARE POSSIBLE. FARTHER S...EXPECT VFR WITH STRATOCU
4-5 KFT.
RETURN TO VFR N SHOULD BE AROUND MIDDAY...EXCEPT EKN...WHERE
IMPROVEMENT TO VFR VSBY TAKES UNTIL AROUND 20Z TUE...MVFR STRATOCU
MAY HANG ON THERE THROUGHOUT THE TAF PERIOD. FARTHER S...STRATOCU
VANISHES LATER TUE AFTERNOON BUT RETURNS LATE TUE NT...AS AN ARCTIC
FRONT ARRIVES FROM THE NW.
LIGHT W TO NW SFC FLOW BECOMES A BIT GUSTY DURING THE DAY
TUE...BEFORE DIMINISHING A BIT TUE NT. LIGHT TO MODERATE W FLOW
ALOFT BECOMES LIGHT W TUE AFTERNOON...AND THEN BEGINS TO STRENGTHEN
FROM THE NW LATE TUE NT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM HIGH.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF LIGHT SNOW AND ASSOCIATED
CATEGORY CHANGES MAY VARY. IFR CIGS COULD NOT BE RULED OUT N TUE
MORNING. EKN CIGS MAY IMPROVE TO VFR FOR A TIME TUE EVENING.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE TUE 02/25/14
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
CRW CONSISTENCY H H H H H H H M M M H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H M
EKN CONSISTENCY H H H H H M M M M M M M
PKB CONSISTENCY H H H L L M M M M M M H
CKB CONSISTENCY H H H H H M M M M M M L
AFTER 06Z WEDNESDAY...
BRIEF IFR POSSIBLE OVERNIGHT TUESDAY NIGHT INTO EARLY WEDNESDAY IN
SNOW ASSOCIATED WITH AN ARCTIC FRONT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/SL
NEAR TERM...TRM
SHORT TERM...SL
LONG TERM...ARJ
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS NORMAN OK
1003 PM CST WED FEB 26 2014
.DISCUSSION...
MINIMUM TEMPERATURES WERE LOWERED SLIGHTLY BASED ON THE RUC TO
BETTER REFLECT LOCAL CONDITIONS ON A DRY, LIGHT-WIND NIGHT.
OTHERWISE THE BIG WARM-UP TOMORROW AND FRIDAY IS UNCHANGED.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 16 54 37 67 / 0 0 10 10
HOBART OK 17 55 36 69 / 0 0 10 10
WICHITA FALLS TX 19 57 39 77 / 0 0 10 10
GAGE OK 20 55 36 64 / 0 0 10 10
PONCA CITY OK 15 46 32 59 / 0 0 20 20
DURANT OK 21 54 36 69 / 0 0 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
09/25
AREA FORECAST DISCUSSION
NWS TULSA OK
941 PM CST WED FEB 26 2014
.DISCUSSION...
WITH CLEAR SKIES AND LIGHT WINDS...TEMPERATURES HAVE ALREADY
FALLEN TO NEAR THE FORECAST LOWS IN SOME PLACES. THE LATEST RUNS
OF THE HRRR HAVE SHOWN THIS TREND WELL...AND THEY SUGGEST THAT
TEMPERATURES WILL HOLD NEARLY STEADY FOR MUCH OF THE REST OF THE
NIGHT. A LIGHT WEST TO SOUTHWEST WIND MAY HOLD THE OFFICIAL
TEMPERATURE AT TUL UP SOME MOST OF THE NIGHT...BUT A WIND SHIFT TO
THE NORTH MAY ALLOW FOR A QUICK FALL AT SUNRISE TO THE FORECAST
LOWS. AS A RESULT...THE CURRENT FORECAST LOOKS GOOD AND NO UPDATE
IS NEEDED AT THIS TIME.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...20
LONG TERM....05
PLATE
AREA FORECAST DISCUSSION...UPDATED
NWS PORTLAND OR
614 AM PST TUE FEB 25 2014
.SYNOPSIS...HIGH PRESSURE ALOFT CENTERED OVER THE PACIFIC NORTHWEST
WILL STRENGTHEN TODAY AS A DEEP LOW PRESSURE SYSTEM REMAINS WELL
OFFSHORE AND MUCH COLDER NORTH FLOW ALOFT RESIDES OVER THE NORTHERN
ROCKIES. OFFSHORE LOW-LEVEL FLOW THROUGH THE COLUMBIA GORGE WILL
CONTINUE THROUGH TONIGHT...THEN GRADUALLY WEAKEN WEDNESDAY. RESIDUAL
COLD AIR NEAR HOOD RIVER AND IN THE UPPER HOOD RIVER VALLEY TODAY
WILL MAINTAIN THREAT OF MIXED PRECIPITATION THIS MORNING. THE RIDGE
SHIFTS TO THE EAST WEDNESDAY AS AN UPPER LOW SWINGS TOWARD SOUTHWEST
OREGON. RAIN SPREADS INTO THE SOUTH ZONES WEDNESDAY EVENING THEN
EXPANDS NORTH WEDNESDAY NIGHT. A LOW PRESSURE AREA REMAINS PARKED OFF
THE NRN CALIFORNIA COAST THURSDAY AND FRIDAY WITH THE BEST THREAT OF
PRECIPITATION OVER THE SOUTH. UNSETTLED AND POSSIBLY QUITE COOL
WEATHER WILL RETURN FOR THE COMING WEEKEND.
&&
UPDATED MARINE DISCUSSION
.SHORT TERM...TUESDAY THROUGH THURSDAY...A RATHER COMPLEX LARGE-SCALE
PATTERN CONTINUES OVER THE PAC NW TODAY. THE MAIN FEATURES OF NOTE
EARLY THIS MORNING INCLUDE AN ELONGATED FRONTAL ZONE ASSOCIATED WITH
A LOW OUT NEAR 44N 145W AND A 500 MB RIDGE AXIS CENTERED OVER WRN
WASHINGTON AND OREGON. HOWEVER...THE RIDGE IS NOT STRONG ENOUGH TO
PREVENT MOISTURE FROM SPREADING NWD IN THE SLY FLOW ALOFT. WATER
VAPOR IMAGERY SHOWS A CONVERGENT BAND OF MOISTURE OVER NRN OREGON AND
SRN WA. COMPLICATING MATTERS IS COLD NLY FLOW DIVING INTO ERN WA. THE
END RESULT IS OFFSHORE LOW-LEVEL FLOW THROUGH THE COLUMBIA GORGE. A
SENSOR IN CORBETT REGISTERED WIND GUSTS TO NEAR 70 MPH BETWEEN 9 AND
10Z. TEMPERATURES IN THE UPPER HOOD RIVER VALLEY WERE RUNNING CLOSE
TO FREEZING JUST BEFORE 10Z.
THE 03Z RUN OF THE HRRR SHOWS THE MOISTURE BAND DRIFTING N OF THE
COLUMBIA RIVER BY 14Z. WILL NEED TO KEEP A MENTION OF MIXED PRECIP
NEAR K4S2 AND IN THE UPPER HOOD RIVER VALLEY THIS MORNING. NAM
SOUNDING FOR A POINT NEAR K4S2 SHOWS A FREEZING-RAIN PROFILE AT 17Z.
HOWEVER...IT APPEARS THE MODEL IS TOO COLD AT THE SURFACE COMPARED TO
CURRENT READINGS. ALL IN ALL...PRECIP IS EXPECTED TO DIMINISH ACROSS
THE NRN ZONES AS THE DAY PROGRESSES. NAM MAINTAINS ABOUT -8 TO -10 MB
KTTD-KDLS GRADIENT TODAY. LOCAL WIND STUDY SUGGESTS WIND GUSTS 65-75
MPH ARE LIKELY AT THE MOST WIND-PRONE AREAS AT THE WEST END OF THE
COLUMBIA GORGE WITH THAT GRADIENT MAGNITUDE. QUITE A CONTRAST IN HIGH
TEMPS TODAY AS WELL. K4S2 WILL BE LUCKY TO REACH 40 DEG WHILE THE SRN
INTERIOR VALLEYS WILL BE IN THE LOW 60S.
TONIGHT AND WED LOOK TO BE DRY AS THE H5 RIDGE STRENGTHENS A BIT IN
RESPONSE TO THE DEEPENING LOW PRES OUT NEAR 140W. THE AIR MASS WILL
BE RATHER MILD AND MOIST IN THE LOWER LEVELS...LEADING TO LOWLAND FOG
TONIGHT. THE OFFSHORE LOW-LEVEL FLOW STARTS TO WANE WED AS THE COLDER
AIR IS FORCED FURTHER EAST. THE NEXT BATCH OF PRECIP ENTERS SW OREGON
WED AFTERNOON AND REACHES THE SWRN ZONES LATE WED AFTERNOON OR WED
EVENING. MODELS DIFFER ON THE UPPER LOW PLACEMENT ...WITH THE ECMWF
FURTHER N...OFF THE SRN OREGON COAST...COMPARED TO THE GFS. MODELS
ARE DEPICTING SOME SORT OF DEFORMATION ZONE SETTING UP WED NIGHT THEN
DRIFTING N INTO SRN WA BY 18Z THU. BUMPED UP POPS WED NIGHT...
ESPECIALLY OVER THE SRN HALF OF THE AREA. MAY NEED TO INCREASE THEM
EVEN MORE SHOULD MODELS MAINTAIN THEIR CURRENT TRENDS. WEISHAAR
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
THURSDAY NIGHT THROUGH MONDAY...SPLIT FLOW WILL PREVAIL THROUGH THE
PERIOD. EXPECT NEAR NORMAL TEMPERATURES AND PRECIPITATION THROUGH
FRIDAY AS A WEAK UPPER LEVEL LOW PRESSURE SYSTEM MOVES INTO THE
REGION AND DISSIPATES THURSDAY NIGHT. A MORE ORGANIZED UPPER LOW
OFFSHORE WILL APPROACH THE AREA FRIDAY...HOWEVER IT LOOKS TO BE
PUSHED SOUTHWARD INTO SOUTHWESTERN OREGON/NORTHERN CALIFORNIA BY A
DEVELOPING UPPER TROUGH/SHORT WAVE THAT WILL DIVE SOUTH OUT OF
CANADA. THIS UPPER TROUGH WILL NEED TO BE MONITORED. AT THIS TIME
MODELS ARE IN FAIR AGREEMENT THAT THE UPPER TROUGH WILL BRING A SURGE
OF COLD AIR INTO THE CWA VIA THE COLUMBIA GORGE LATE FRIDAY INTO
SATURDAY. IN ADDITION...BOTH THE ECMWF AND TO A LESSER EXTENT THE GFS
DEVELOP A SURFACE LOW OFFSHORE FRIDAY NIGHT...FURTHER INDUCING COLD
OFFSHORE FLOW AND POTENTIALLY ENTRAINING MOISTURE FROM THE
AFOREMENTIONED UPPER LOW TO THE SOUTH AND ADVECTING IT NORTHWARD. ALL
IN ALL...THERE IS POTENTIAL FOR SNOW OR FREEZING RAIN SATURDAY
THROUGH MONDAY FROM PDX EAST INTO THE GORGE. HOWEVER... PLENTY OF
UNCERTAINTY REMAINS. FORECASTER CONFIDENCE IS VERY LOW AT THIS TIME
ABOUT WHETHER TEMPERATURES WILL IN FACT BE COLD ENOUGH... OR IF THE
COLD AIR AND MOISTURE WILL BE COINCIDENT. BB
&&
.AVIATION...MOSTLY VFR CONDITIONS EARLY THIS MORNING EXCEPT FOR
PATCHY MVFR TO IFR CIGS IN THE CENTRAL AND SOUTHERN WILLAMETTE
VALLEY AND ALONG THE COLUMBIA RIVER NEAR KKLS. THE IFR CONDITIONS
HAVE BEEN FAIRLY ISOLATED TO VCNTY OF KEUG SO FAR. EXPECT IFR
CONDITIONS TO CONTINUE THERE THROUGH THIS MORNING. DEW POINT
DEPRESSIONS SUGGEST THAT OTHER VALLEY LOCATIONS WILL SEE SOME FOG
AND HAVE TEMPORARY MVFR-IFR CONDITIONS THIS MORNING...ESPECIALLY
WHERE THERE IS CALM WINDS. HIGH CLOUDS STREAMING OVER SHOULD
MINIMIZE RADIATION COOLING AND DO NOT EXPECT THE FOG TO BE
WIDESPREAD.
EAST WINDS WILL DOMINATE TODAY AND TONIGHT WITH
NORTHERLY WINDS THROUGH THE CENTRAL WILLAMETTE VALLEY. THE WINDS
WILL BE GUSTY NEAR KTTD WITH GUSTS OF 40 KT LIKELY THIS AFTERNOON
AND EVENING. THE WINDS SHOULD KEEP MOST AREAS VFR EXCEPT FOR THE
MORE SHELTERED AREAS LIKE KEUG...KHIO AND KKLS WHERE THERE WILL BE
PERIODS OF REDUCED VSBYS DUE TO FOG THIS MORNING AND POSSIBLY
AGAIN LATE TONIGHT.
KPDX AND APPROACHES...VFR CONDITIONS EXPECTED TODAY. EAST WINDS AT
THE AIRPORT TODAY WITH POSSIBLE GUSTS UP TO 25 KT THIS AFTERNOON
AND EVENING. HARTLEY
&&
.MARINE UPDATE...EAST WINDS ARE STRONGER AROUND THE COLUMBIA RIVER
ENTRANCE AREA AS BUOY #29 HAS BEEN REPORTING WINDS OF 15 TO 20 KT
WITH GUSTS TO CLOSE TO 30 KT. ALTHOUGH THESE WINDS ARE PROBABLY NOT
WIDESPREAD...THINK THEY WILL BE ENOUGH FAR REACHING TO JUSTIFY A
SMALL CRAFT ADVISORY. THE STRONGEST WINDS WILL BE AROUND THE
ENTRANCE OF THE COLUMBIA RIVER AND NORTHWARD.
PREVIOUS MARINE DISCUSSION...HIGH PRESSURE INLAND COMBINED WITH LOW
PRESSURE OVER THE NE PACIFIC HAS RESULTED IN EAST TO SOUTHEAST WINDS
OVER THE WATERS. THE OFFSHORE WINDS ARE STRONGEST TO THE NORTH
ESPECIALLY NEAR THE ENTRANCE OF THE COLUMBIA RIVER. THE SURFACE
PRESSURE GRADIENT WILL CONTINUE TO STRENGTHEN TODAY AND AREAS NORTH
OF CANNON BEACH MAY HAVE AN OCCASIONAL GUST TO 25 KT. DO NOT THINK
THAT THESE GUSTS WILL BE WIDESPREAD OR FREQUENT ENOUGH TO WARRANT AN
ADVISORY..BUT WILL MONITOR THE WINDS CLOSELY IN CASE AN UPDATE IS
NECESSARY.
SEAS BECOME COMPLICATED TUESDAY THROUGH THURSDAY AS MULTIPLE LOWS
WEST AND SOUTHWEST OF THE WATERS WILL GENERATE A VARIETY OF SWELL
TRAINS THROUGH THE WATERS. THE SWELL HEIGHTS OF THE INDIVIDUAL
TRAINS ARE GENERALLY LESS THAN 5 FEET. OVERALL WAVE HEIGHTS WILL
GENERALLY BE BETWEEN 6 AND 9 FEET TONIGHT THROUGH THURSDAY
COMPILED BY A LONG PERIOD SW SWELL AND A SHORTER PERIOD W SWELL.
THE SEAS IN THE SOUTHERN WATERS MAY BE SLIGHTLY STRONGER AND AN
ADVISORY FOR SEAS MAY BE NECESSARY FOR AREAS SOUTH OF CASCADE HEAD
WEDNESDAY AND WEDNESDAY NIGHT. HARTLEY
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 PM THIS EVENING FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
OUT 60 NM.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS PORTLAND OR
208 AM PST TUE FEB 25 2014
.SYNOPSIS...HIGH PRESSURE ALOFT CENTERED OVER THE PACIFIC NORTHWEST
WILL STRENGTHEN TODAY AS A DEEP LOW PRESSURE SYSTEM REMAINS WELL
OFFSHORE AND MUCH COLDER NORTH FLOW ALOFT RESIDES OVER THE NORTHERN
ROCKIES. OFFSHORE LOW-LEVEL FLOW THROUGH THE COLUMBIA GORGE WIL
CONTINUE THROUGH TONIGHT...THEN GRADUALLY WEAKEN WEDNESDAY. RESIDUAL
COLD AIR NEAR HOOD RIVER AND IN THE UPPER HOOD RIVER VALLEY TODAY
WILL MAINTAIN THREAT OF MIXED PRECIPITATION THIS MORNING. THE RIDGE
SHIFTS TO THE EAST WEDNESDAY AS AN UPPER LOW SWINGS TOWARD SOUTHWEST
OREGON. RAIN SPREADS INTO THE SOUTH ZONES WEDNESDAY EVENING THEN
EXPANDS NORTH WEDNESDAY NIGHT. A LOW PRESSURE AREA REMAINS PARKED OFF
THE NRN CALIFORNIA COAST THURSDAY AND FRIDAY WITH THE BEST THREAT OF
PRECIPITATION OVER THE SOUTH. UNSETTLED AND POSSIBLY QUITE COOL
WEATHER WILL RETURN FOR THE COMING WEEKEND.
&&
.SHORT TERM...TUESDAY THROUGH THURSDAY...A RATHER COMPLEX LARGE-SCALE
PATTERN CONTINUES OVER THE PAC NW TODAY. THE MAIN FEATURES OF NOTE
EARLY THIS MORNING INCLUDE AN ELONGATED FRONTAL ZONE ASSOCIATED WITH
A LOW OUT NEAR 44N 145W AND A 500 MB RIDGE AXIS CENTERED OVER WRN
WASHINGTON AND OREGON. HOWEVER...THE RIDGE IS NOT STRONG ENOUGH TO
PREVENT MOISTURE FROM SPREADING NWD IN THE SLY FLOW ALOFT. WATER
VAPOR IMAGERY SHOWS A CONVERGENT BAND OF MOISTURE OVER NRN OREGON AND
SRN WA. COMPLICATING MATTERS IS COLD NLY FLOW DIVING INTO ERN WA. THE
END RESULT IS OFFSHORE LOW-LEVEL FLOW THROUGH THE COLUMBIA GORGE. A
SENSOR IN CORBETT REGISTERED WIND GUSTS TO NEAR 70 MPH BETWEEN 9 AND
10Z. TEMPERATURES IN THE UPPER HOOD RIVER VALLEY WERE RUNNING CLOSE
TO FREEZING JUST BEFORE 10Z.
THE 03Z RUN OF THE HRRR SHOWS THE MOISTURE BAND DRIFTING N OF THE
COLUMBIA RIVER BY 14Z. WILL NEED TO KEEP A MENTION OF MIXED PRECIP
NEAR K4S2 AND IN THE UPPER HOOD RIVER VALLEY THIS MORNING. NAM
SOUNDING FOR A POINT NEAR K4S2 SHOWS A FREEZING-RAIN PROFILE AT 17Z.
HOWEVER...IT APPEARS THE MODEL IS TOO COLD AT THE SURFACE COMPARED TO
CURRENT READINGS. ALL IN ALL...PRECIP IS EXPECTED TO DIMINISH ACROSS
THE NRN ZONES AS THE DAY PROGRESSES. NAM MAINTAINS ABOUT -8 TO -10 MB
KTTD-KDLS GRADIENT TODAY. LOCAL WIND STUDY SUGGESTS WIND GUSTS 65-75
MPH ARE LIKELY AT THE MOST WIND-PRONE AREAS AT THE WEST END OF THE
COLUMBIA GORGE WITH THAT GRADIENT MAGNITUDE. QUITE A CONTRAST IN HIGH
TEMPS TODAY AS WELL. K4S2 WILL BE LUCKY TO REACH 40 DEG WHILE THE SRN
INTERIOR VALLEYS WILL BE IN THE LOW 60S.
TONIGHT AND WED LOOK TO BE DRY AS THE H5 RIDGE STRENGTHENS A BIT IN
RESPONSE TO THE DEEPENING LOW PRES OUT NEAR 140W. THE AIR MASS WILL
BE RATHER MILD AND MOIST IN THE LOWER LEVELS...LEADING TO LOWLAND FOG
TONIGHT. THE OFFSHORE LOW-LEVEL FLOW STARTS TO WANE WED AS THE COLDER
AIR IS FORCED FURTHER EAST. THE NEXT BATCH OF PRECIP ENTERS SW OREGON
WED AFTERNOON AND REACHES THE SWRN ZONES LATE WED AFTERNOON OR WED
EVENING. MODELS DIFFER ON THE UPPER LOW PLACEMENT ...WITH THE ECMWF
FURTHER N...OFF THE SRN OREGON COAST...COMPARED TO THE GFS. MODELS
ARE DEPICTING SOME SORT OF DEFORMATION ZONE SETTING UP WED NIGHT THEN
DRIFTING N INTO SRN WA BY 18Z THU. BUMPED UP POPS WED NIGHT...
ESPECIALLY OVER THE SRN HALF OF THE AREA. MAY NEED TO INCREASE THEM
EVEN MORE SHOULD MODELS MAINTAIN THEIR CURRENT TRENDS. WEISHAAR
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
THURSDAY NIGHT THROUGH MONDAY...SPLIT FLOW WILL PREVAIL THROUGH THE
PERIOD. EXPECT NEAR NORMAL TEMPERATURES AND PRECIPITATION THROUGH
FRIDAY AS A WEAK UPPER LEVEL LOW PRESSURE SYSTEM MOVES INTO THE
REGION AND DISSIPATES THURSDAY NIGHT. A MORE ORGANIZED UPPER LOW
OFFSHORE WILL APPROACH THE AREA FRIDAY...HOWEVER IT LOOKS TO BE
PUSHED SOUTHWARD INTO SOUTHWESTERN OREGON/NORTHERN CALIFORNIA BY A
DEVELOPING UPPER TROUGH/SHORT WAVE THAT WILL DIVE SOUTH OUT OF
CANADA. THIS UPPER TROUGH WILL NEED TO BE MONITORED. AT THIS TIME
MODELS ARE IN FAIR AGREEMENT THAT THE UPPER TROUGH WILL BRING A SURGE
OF COLD AIR INTO THE CWA VIA THE COLUMBIA GORGE LATE FRIDAY INTO
SATURDAY. IN ADDITION...BOTH THE ECMWF AND TO A LESSER EXTENT THE GFS
DEVELOP A SURFACE LOW OFFSHORE FRIDAY NIGHT...FURTHER INDUCING COLD
OFFSHORE FLOW AND POTENTIALLY ENTRAINING MOISTURE FROM THE
AFOREMENTIONED UPPER LOW TO THE SOUTH AND ADVECTING IT NORTHWARD. ALL
IN ALL...THERE IS POTENTIAL FOR SNOW OR FREEZING RAIN SATURDAY
THROUGH MONDAY FROM PDX EAST INTO THE GORGE. HOWEVER... PLENTY OF
UNCERTAINTY REMAINS. FORECASTER CONFIDENCE IS VERY LOW AT THIS TIME
ABOUT WHETHER TEMPERATURES WILL IN FACT BE COLD ENOUGH... OR IF THE
COLD AIR AND MOISTURE WILL BE COINCIDENT. BB
&&
.AVIATION...MOSTLY VFR CONDITIONS EARLY THIS MORNING EXCEPT FOR
PATCHY MVFR TO IFR CIGS IN THE CENTRAL AND SOUTHERN WILLAMETTE
VALLEY AND ALONG THE COLUMBIA RIVER NEAR KKLS. THE IFR CONDITIONS
HAVE BEEN FAIRLY ISOLATED TO VCNTY OF KEUG SO FAR. EXPECT IFR
CONDITIONS TO CONTINUE THERE THROUGH THIS MORNING. DEW POINT
DEPRESSIONS SUGGEST THAT OTHER VALLEY LOCATIONS WILL SEE SOME FOG
AND HAVE TEMPORARY MVFR-IFR CONDITIONS THIS MORNING...ESPECIALLY
WHERE THERE IS CALM WINDS. HIGH CLOUDS STREAMING OVER SHOULD
MINIMIZE RADIATION COOLING AND DO NOT EXPECT THE FOG TO BE
WIDESPREAD.
EAST WINDS WILL DOMINATE TODAY AND TONIGHT WITH
NORTHERLY WINDS THROUGH THE CENTRAL WILLAMETTE VALLEY. THE WINDS
WILL BE GUSTY NEAR KTTD WITH GUSTS OF 40 KT LIKELY THIS AFTERNOON
AND EVENING. THE WINDS SHOULD KEEP MOST AREAS VFR EXCEPT FOR THE
MORE SHELTERED AREAS LIKE KEUG...KHIO AND KKLS WHERE THERE WILL BE
PERIODS OF REDUCED VSBYS DUE TO FOG THIS MORNING AND POSSIBLY
AGAIN LATE TONIGHT.
KPDX AND APPROACHES...VFR CONDITIONS EXPECTED TODAY. EAST WINDS AT
THE AIRPORT TODAY WITH POSSIBLE GUSTS UP TO 25 KT THIS AFTERNOON
AND EVENING. HARTLEY
&&
.MARINE...HIGH PRESSURE INLAND COMBINED WITH LOW PRESSURE OVER THE NE
PACIFIC HAS RESULTED IN EAST TO SOUTHEAST WINDS OVER THE WATERS.
THE OFFSHORE WINDS ARE STRONGEST TO THE NORTH ESPECIALLY NEAR THE
ENTRANCE OF THE COLUMBIA RIVER. THE SURFACE PRESSURE GRADIENT WILL
CONTINUE TO STRENGTHEN TODAY AND AREAS NORTH OF CANNON BEACH MAY
HAVE AN OCCASIONAL GUST TO 25 KT. DO NOT THINK THAT THESE GUSTS
WILL BE WIDESPREAD OR FREQUENT ENOUGH TO WARRANT AN ADVISORY..BUT
WILL MONITOR THE WINDS CLOSELY IN CASE AN UPDATE IS NECESSARY.
SEAS BECOME COMPLICATED TUESDAY THROUGH THURSDAY AS MULTIPLE LOWS
WEST AND SOUTHWEST OF THE WATERS WILL GENERATE A VARIETY OF SWELL
TRAINS THROUGH THE WATERS. THE SWELL HEIGHTS OF THE INDIVIDUAL
TRAINS ARE GENERALLY LESS THAN 5 FEET. OVERALL WAVE HEIGHTS WILL
GENERALLY BE BETWEEN 6 AND 9 FEET TONIGHT THROUGH THURSDAY
COMPILED BY A LONG PERIOD SW SWELL AND A SHORTER PERIOD W SWELL.
THE SEAS IN THE SOUTHERN WATERS MAY BE SLIGHTLY STRONGER AND AN
ADVISORY FOR SEAS MAY BE NECESSARY FOR AREAS SOUTH OF CASCADE HEAD
WEDNESDAY AND WEDNESDAY NIGHT. HARTLEY
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1113 PM CST MON FEB 24 2014
.DISCUSSION...
UPDATED FOR 06Z AVIATION DISCUSSION
&&
.PREV DISCUSSION... /ISSUED 923 PM CST MON FEB 24 2014/
UPDATE...
CLOUDS HAVE DEVELOPED QUICKLY OVER ARKANSAS THIS EVENING AS WARM
AIR IS OVERRUNNING THE COLDER AIR AT THE SFC. THE CLOUDS HAVE
PUSHED EAST AND NOW COVER MUCH OF THE MIDSOUTH. THE WEAK OVERRUNNING
PATTERN WILL PRODUCE AREAS OF LIGHT RAIN OVER MAINLY NORTH
MISSISSIPPI OVERNIGHT. TEMPERATURES HAVE EITHER HELD STEADY OR
HAVE GONE UP A COUPLE OF DEGREES SINCE THE CLOUDS HAVE PUSHED IN.
WILL UPDATE TO REMOVE MENTION OF SNOW AS TEMPERATURES WILL REMAIN
WELL ABOVE FREEZING AT AND ABOVE THE SFC TO KEEP PRECIPITATION
RAIN. WILL ALSO ADJUST SKY CONDITIONS TO CLOUDY. WILL KEEP 20 POPS
FROM MEMPHIS SOUTHWARD BUT LATEST HRRR INDICATES THAT MORE
DEVELOPMENT COULD OCCUR THAN OTHER MODELS ARE SUGGESTING. IF IT
PANS OUT THEN HIGHER POPS MAY BE NEEDED. WILL CONTINUE TO MONITOR
AND FUTURE UPDATES MAY BE NEEDED.
KRM
DISCUSSION... /ISSUED 329 PM CST MON FEB 24 2014/
TEMPERATURES ACROSS THE MIDSOUTH RANGE FROM THE MIDDLE 40S TO
MIDDLE 50S AROUND 10 TO 15 DEGREES COOLER THAN THEY WERE AT THIS
TIME YESTERDAY. MOST OF THE MIDSOUTH HAS SEEN ABUNDANT SUNSHINE
DURING THE DAY TODAY...BUT HIGH CLOUDS ARE NOW OVERSPREADING NORTH
MISSISSIPPI. SKIES WILL TURN MOSTLY CLOUDY ACROSS MOST OF THE
REGION OVERNIGHT KEEPING TEMPERATURES FROM COOLING QUITE AS MUCH
AS LAST NIGHT. MORNING LOWS TOMORROW WILL BE IN THE 30S ACROSS
MOST OF THE REGION...AND ABOVE FREEZING FOR THE SOUTHERN HALF OF
THE FORECAST AREA INCLUDING THE MEMPHIS METRO AREA.
TOMORROW...SURFACE WINDS WILL SHIFT MORE EASTERLY WITH WEST TO
NORTHWEST FLOW SETTING UP ALOFT. A STRONG MID LEVEL DISTURBANCE
WILL TRACK FROM NORTH TEXAS ACROSS ARKANSAS INTO NORTH MISSISSIPPI
LATE TOMORROW THROUGH EARLY WEDNESDAY. THERE IS SOME QUESTION
REGARDING HOW MUCH MOISTURE WILL STILL BE AVAILABLE LATE TUESDAY
NIGHT WHEN SUBFREEZING TEMPERATURES ARRIVE...ESPECIALLY IN WEST
TENNESSEE...THE MISSOURI BOOTHEEL AND NORTHEAST ARKANSAS FOR
FROZEN PRECIPITATION...BUT AT LEAST A BRIEF PERIOD OF SNOW OR A
RAIN SNOW MIX LOOKS POSSIBLE AREA WIDE. THE BEST CHANCE OF
ACCUMULATING SNOW LOOKS TO BE ACROSS NORTH MISSISSIPPI...BUT HERE
TEMPERATURES COLD ENOUGH FOR SNOW WILL NOT LIKELY ARRIVE UNTIL
WELL AFTER MIDNIGHT...OR EVEN UNTIL AROUND SUNRISE. DO NOT
ANTICIPATE THE NEED FOR ANY WINTER STORM
WARNINGS/WATCHES/ADVISORIES AT THIS TIME. HPC WINTER WEATHER
PRODUCTS DO NOT INCLUDE ANY FREEZING OR FROZEN PRECIPITATION.
MODELS LIQUID EQUIVALENT PRECIPITATION IS GENERALLY ONE TENTH OF
AN INCH OR LESS WHICH SHOULD NOT TRANSLATE TO MORE THAN A DUSTING
OF SNOW...AND THAT IS IN A BEST CASE SCENARIO WHERE ALL
PRECIPITATION FALLS AS SNOW AND IT DOES NOT MELT.
SURFACE HIGH PRESSURE WILL BUILD IN QUICKLY ON WEDNESDAY.
CONSIDERABLE SUNSHINE IS LIKELY BY THE EARLY AFTERNOON HOURS...BUT
NORTHERLY WIND WILL CURB AFTERNOON HIGHS KEEPING ALL OF THE
MIDSOUTH IN THE 30S...AND THE COLDEST LOCATIONS BELOW FREEZING.
THURSDAY WILL BEGIN VERY COLD WITH TEMPERATURES GENERALLY BETWEEN
15 AND 25 DEGREES BUT WARM INTO THE MID TO UPPER 40S DURING THE
AFTERNOON.
ANOTHER CHANCE OF PRECIPITATION WILL MOVE IN FRIDAY...GUIDANCE
SUGGESTS MULTIPLE PHASE CHANGES BETWEEN RAIN AND SNOW...OR A MIX
OF THE TWO AS TEMPERATURES WARM DURING THE DAY AND THEN COOL OFF
AGAIN FRIDAY NIGHT. THE OVERALL PATTERN LOOKS FAIRLY GOOD FOR A
MIDSOUTH SNOWFALL. A SURFACE LOW WILL TRACK FROM NORTH TEXAS
ACROSS CENTRAL ARKANSAS...BUT AT THIS TIME THICKNESSES DO NOT
SUPPORT ALL SNOW AND ACTUALLY RISE BY 30 METERS OR SO FROM MIDDAY
FRIDAY THROUGH MIDNIGHT. THE ECMWF SOLUTION IS EVEN WARMER THAN
THE GFS AND WOULD RESULT IN ALL RAIN.
SATURDAY LOOKS DRY WITH HIGHS RANGING FROM THE UPPER 30S TO UPPER
40S ACROSS MOST OF THE REGION. YET ANOTHER BRIEF CHANCE OF SNOW IS
IN THE FORECAST EARLY SUNDAY..MAINLY ACROSS NORTHERN...AREAS IF
MOISTURE ARRIVES BEFORE TEMPERATURES WARM. HIGHS SUNDAY SHOULD BE
WELL ABOVE FREEZING SO ANY SNOW THAT DOES FALL WILL MELT QUICKLY.
EARLY NEXT WEEK LOOKS WARMER AND RAINY.
&&
.AVIATION...
06Z TAF CYCLE
A DECK OF STRATOCU WILL CONTINUE ACROSS THE MIDSOUTH OVERNIGHT.
EXPECT CIGS TO REMAIN VFR IN THE 3500-4500FT RANGE OVERNIGHT WITH
A FEW SHRAS AT KMEM AND KTUP. THERE IS SOME RISK OF MVFR CIGS AT
KMEM LATER TONIGHT BUT NOT CONFIDENT ENOUGH TO MENTION IN TAFS
ATTM. AS DRY AIR MOVES IN FROM THE NORTH ON TUESDAY CLOUDS WILL
CLEAR OUT OF KJBR AND KMKL WHILE REMAINING AT KMEM AND KTUP.
WINDS WILL GENERALLY BE NE AT 5 KTS OVERNIGHT INCREASING TO 8-10
KTS TUESDAY...AND TO 10-14 KTS TUESDAY EVENING.
SJM
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 40 54 29 36 / 20 10 60 10
MKL 34 50 24 32 / 10 10 40 0
JBR 34 49 25 34 / 10 10 40 0
TUP 40 57 32 39 / 20 10 60 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
903 PM CST WED FEB 26 2014
.UPDATE...
WE HAVE UPDATED THE FORECAST TO REMOVE THE MENTION OF
PRECIPITATION THROUGH THE REMINDER OF TONIGHT. RADAR ECHOES
CONTINUE TO DECREASE ACROSS SOUTH CENTRAL TEXAS THIS EVENING AS
DRIER AIR IN THE LOW-LEVELS AND MID-LEVEL SUBSIDENCE SPREAD INTO
THE REGION. WE HAVE ALSO REDUCED CLOUD COVER ACROSS MOST AREAS...
ALTHOUGH LOW CLOUDS MAY PERSIST THROUGH TONIGHT ALONG THE RIO
GRANDE. WE HAVE LOWERED TEMPERATURES A FEW DEGREES ACROSS PORTIONS
OF THE HILL COUNTRY AND ADJACENT I-35 CORRIDOR AS DEW POINTS WILL
DROP INTO THE TEENS OVERNIGHT. WE/LL NEED TO MONITOR LLANO...
BURNET AND WILLIAMSON COUNTIES AS THE RUC13 SUGGESTS LOWS MAY DROP
INTO THE MID 20S. WE HAVE ALSO LOWERED TEMPERATURES A DEGREE OR
TWO ALONG THE HIGHWAY 77 CORRIDOR AS DRIER AIR...LIGHT WINDS AND
DECREASING CLOUD COVER ARE EXPECTED OVER THIS REGION. OTHERWISE...
MINOR CHANGES WERE MADE TO THE WINDS AND DEW POINTS BASED ON THE
LATEST OBSERVATIONAL TRENDS.
&&
.PREV DISCUSSION... /ISSUED 527 PM CST WED FEB 26 2014/
AVIATION...
AN AREA OF DRIZZLE/LIGHT RAIN MAINLY ALONG AND SOUTH OF HIGHWAY 90...
WILL CONTINUE TO PUSH TO THE SOUTHEAST THROUGH THIS EVENING. BY
00Z THURSDAY...THIS ACTIVITY SHOULD BE PUSHING OVER THE COASTAL
PLAINS AREA...WHILE NORTHERLY LOW LEVEL WINDS BRING DRIER AIR TO
THE REGION. SURFACE HIGH PRESSURE SYSTEM OVER EAST TEXAS LATE THIS
AFTERNOON/EARLY EVENING WILL PUSH TO THE SOUTHEAST LATE TONIGHT
INTO THURSDAY. THIS WILL RESULT IN THE RETURN OF SOUTHERLY FLOW
ACROSS THE RIO GRANDE PLAINS WITH NORTH/NORTHEASTERLY WINDS ACROSS
THE EASTERN TWO-THIRDS OF SOUTH CENTRAL TEXAS OVERNIGHT AND EARLY
THURSDAY. SOUTHERLY WINDS ARE EXPECTED TO DOMINATE THE AREA
THURSDAY AFTERNOON AS SURFACE HIGH PUSHES TO THE EAST. COULD SEE
UPPER END MVFR CONDITIONS ACROSS KSAT AND KSSF OVERNIGHT DUE TO
CEILINGS OF 5 KFT. OTHERWISE...VFR EXPECTED ACROSS THE ENTIRE FORECAST
AREA BY 12Z THURSDAY THROUGH THE REMAINDER OF THE FORECAST CYCLE.
PREV DISCUSSION... /ISSUED 320 PM CST WED FEB 26 2014/
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...
THE UPPER LEVEL PATTERN THIS MORNING SHOWED A LARGE AMPLITUDE
TROUGH EXTENDING FROM THE GREAT LAKES TO NORTHEAST TEXAS AND A
SECOND TROUGH MOVING ACROSS NORTHERN MEXICO. THIS SECOND FEATURE
IS PULLING MID-LEVEL MOISTURE FROM THE TROPICS ACROSS MEXICO INTO
TEXAS. THE 700 TO 300 MB FLOW ACROSS TEXAS IS SLIGHTLY ANTICYCLONIC.
AT THE SURFACE THE COLD FRONT HAS MOVED SOUTH OF TEXAS AND WINDS
ARE FROM THE NORTH. COLDER...DRIER AIR IS DROPPING INTO OUR CWA.
PRECIPITATION WILL BE ENDING THIS EVENING FROM NORTHWEST TO
SOUTHEAST. WHERE THERE IS PRECIPITATION THIS EVENING..TEMPERATURES
WILL BE ABOVE FREEZING AND IT SHOULD BE ALL RAIN. LOW TEMPERATURES
OVERNIGHT WILL DROP TO FREEZING OR BELOW OVER THE HILL COUNTRY AND
ADJACENT AREAS FROM CONCAN TO LA GRANGE. MOST OF THE SAN ANTONIO
METRO AREA WILL BE ABOVE FREEZING WITH ONLY THE EXTREME NORTHERN
PORTION OF THE AREA DROPPING TO OR BELOW 32. A WARMING TREND WILL
BEGIN THURSDAY WITH THE SURFACE WINDS TURNING TO THE SOUTHEAST BY
THE AFTERNOON.
LONG TERM (FRIDAY THROUGH WEDNESDAY)...
AN UPPER LEVEL RIDGE WILL BUILD OVER THE SOUTHERN PLAINS FOR THE
END OF THE WEEK. THE LOW LEVEL FLOW WILL REMAIN FROM THE SOUTHEAST
MAKING FRIDAY AND SATURDAY QUITE WARM. SATURDAY MORNING THE
SOUTHEASTERLY FLOW MAY PRODUCE PATCHY DRIZZLE ACROSS THE THE
SOUTHEASTERN PART OF THE CWA AS FAR NORTH AS I-35. SUNDAY ANOTHER
COLD FRONT WILL MOVE THROUGH BRINGING A CHANCE FOR SHOWERS AND
THUNDERSTORMS SUNDAY AND MONDAY. IT WILL ALSO BRING ANOTHER ROUND
OF COLD AIR WITH FREEZING TEMPERATURES POSSIBLE AGAIN IN THE HILL
COUNTRY TUESDAY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 32 63 46 78 59 / - 0 - - -
AUSTIN BERGSTROM INTL AIRPORT 28 60 41 76 55 / - 0 - - -
NEW BRAUNFELS MUNI AIRPORT 32 61 42 76 57 / - 0 - - -
BURNET MUNI AIRPORT 27 60 42 77 53 / - 0 - - -
DEL RIO INTL AIRPORT 36 65 45 81 56 / - - 0 - -
GEORGETOWN MUNI AIRPORT 28 60 42 75 55 / - 0 - - -
HONDO MUNI AIRPORT 34 64 42 81 54 / - 0 - - -
SAN MARCOS MUNI AIRPORT 31 60 42 75 57 / - 0 - - -
LA GRANGE - FAYETTE REGIONAL 30 58 44 72 60 / - - 10 - -
SAN ANTONIO INTL AIRPORT 33 65 47 80 60 / - 0 - - -
STINSON MUNI AIRPORT 35 64 45 79 58 / - 0 - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...17
SYNOPTIC/GRIDS...24
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
333 PM CST TUE FEB 25 2014
.DISCUSSION...
FRONT IS NOW PUSHING INTO NRN PORTIONS OF SE TX. SHOULD BE BETWEEN
I-10 AND THE COAST AROUND MIDNIGHT AND OFF THE BEACHES BY 4AM
(EFFECTIVELY ENDING SEA FOG ISSUES FOR A FEW DAYS). STARTING TO
SEE SOME SCT PRECIP DEVELOP ACROSS S PARTS OF THE AREA AND EXPECT
IT TO GRADUALLY INCREASE IN COVERAGE AHEAD OF, AND ESPECIALLY
BEHIND, THE FRONT. HRRR MODEL AND TO A DEGREE NAM12 HAS DONE
FAIRLY WELL WITH RAINFALL DEPICTION (OR LACK THEREOF) SO FAR TODAY
AND SHORT TERM FCST WAS TRENDED THAT WAY. GFS/ECMWF HAVE BEEN
HORRIBLY OVERDONE BOTH IN COVERAGE & AMOUNTS UP TO THIS TIME.
PERIODS OF PRECIP WILL LIKELY CONTINUE THRU WED IN ASSOCIATION
WITH H85 FRONT AND UPPER IMPULSES RIDING FURTHER OVERHEAD IN THE
WRLY FLOW ALOFT. CONSIDERING STRONG CAA, CLOUDINESS AND PRECIP THE HIGHS
FOR THE 24 HOUR PERIOD WILL OCCUR AROUND MIDNIGHT FOLLOWED BY
FALLING AND/OR STEADY TEMPS IN THE 40S WED. RAIN SHOULD TAPER OFF
WED EVENING.
COOL WX CONTINUES THURS BUT ONSHORE WIND WILL BE RESUMING AS HIGH
PRES MOVES EAST AND NEXT SHORTWAVE STARTS DIGGING SEWD DOWN THE
4-CORNERS AREA. THIS DISTURBANCE ISN`T AS IMPRESSIVE AS PREVIOUS
DAYS AND DON`T ANTICIPATE MUCH OF AN IMPACT HERE AS IT MOVES ALONG
THE RED RIVER FRIDAY...AS BEST ENERGY WILL BE WELL NORTH AND A
CAP SHOULD BE IN PLACE. FURTHER LOWERED POPS.
WARMING TREND CONTINUES THRU THE WEEKEND WITH ONSHORE FLOW IN
PLACE. APPEARS THAT WE`LL PROBABLY HAVE ANOTHER COASTAL FOG EVENT
BUT LOOKS LIKE MARDI GRAS PARADES SHOULD OTHERWISE BE DRY PRIOR TO
MID TO LATE SUNDAY AFTN. NEXT STORM SYSTEM APPROACHES FROM THE
WEST LATE IN THE WEEKEND AND KEPT 20-40% POPS IN PLACE SUN AFTN/NIGHT
AHEAD OF THE NEXT FRONT THAT`LL BE MOVING THRU SUNDAY NIGHT OR
MONDAY. KNOCKED TEMPS DOWN EARLY NEXT WEEK (MAYBE NOT ENOUGH) AS
1040+MB HIGH DROPS INTO THE PLAINS. 47
&&
.MARINE...
SEA FOG WILL CONTINUE OVER THE GULF WATERS THIS AFTERNOON. AM
EXPECTING THE FOG TO REDEVELOP AND BECOME DENSE OVER THE BAYS LATER
THIS AFTERNOON AND EVENING. THE FOG WILL CLEAR OUT BETWEEN MIDNIGHT
AND SUNRISE AS A COLD FRONT PUSHES THROUGH THE BAYS AND OFF THE
COAST. THE MODELS HAVE BEEN FAIRLY CONSISTENT THE PAST FEW DAYS AND
AM FAIRLY CONFIDENT ON THE TIMING. EXPECT THE FRONT TO MOVE THROUGH
THE BAYS BY AROUND 3 AM AND THEN BEYOND 20 NM OFFSHORE BY 4 AM. THE
12Z MODEL RUN AND GUIDANCE FROM THIS MORNING FORECASTED SLIGHTLY
HIGHER WINDS...INDICATING THAT SMALL CRAFT ADVISORIES ARE LIKELY FOR
THE GULF WATERS AND MATAGORDA BAY. WOULD NOT BE SURPRISED IF WINDS
INCREASE TO BETWEEN 20 AND 25 KNOTS FOR AT LEAST MOST OF THE LOWER
PART OF GALVESTON BAY...ALSO. EXPECT THE NORTHEASTERLY WINDS TO
DIMINISH WEDNESDAY NIGHT AND THURSDAY. ANOTHER FOG EVENT MAY DEVELOP
BY LATE THIS WEEK AS ONSHORE REDEVELOPS. 40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 43 43 33 57 42 / 70 60 20 10 10
HOUSTON (IAH) 49 49 36 59 43 / 70 70 30 10 10
GALVESTON (GLS) 54 54 42 55 53 / 70 60 40 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...DENSE FOG ADVISORY UNTIL 4 AM CST WEDNESDAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20
TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
557 AM CST TUE FEB 25 2014
.DISCUSSION...
SEE 12Z AVIATION DISCUSSION.
&&
.AVIATION...
A WEAK BOUNDARY EXTENDS EAST TO WEST ACROSS TEXAS TO A WEAK AREA
OF LOW PRESSURE OVER SOUTHWEST TEXAS. WATER VAPOR IMAGERY SHOWS A
DISTURBANCE APPROACHING SOUTHEAST TEXAS SO FEEL LIFT WILL INCREASE
AND COUPLED WITH ABUNDANT LOW LEVEL MOISTURE SHOULD ALLOW FOR AT
LEAST SCT SHRA TODAY. LEANED A BIT TOWARD THE HRRR BUT IT LOOKS A
BIT OVERDONE. LIFR/IFR CONDS TO PREVAIL FOR MUCH OF THE MORNING
WITH SOME IMPROVEMENT IN THE AFTN. A COLD FRONT WILL CROSS THE
AREA TONIGHT. ADDED TSRA FOR LATE AFTN/TONIGHT AS INSTABILITY
INCREASES. MODELS ALL ON THE SAME PAGE FOR A STEADY WIDESPREAD
RAIN ON WED MORNING AS ANOTHER DISTURBANCE INTERACTS WITH THE 850
MB BOUNDARY. 43
&&
.PREV DISCUSSION... /ISSUED 456 AM CST TUE FEB 25 2014/
DISCUSSION...
FOG HAS FORMED THIS MORNING ACROSS THE AREA WITH IT BEING MOST
DENSE ACROSS THE SOUTHERN HALF OF THE CWA. A WARM FRONT REMAINS
JUST SOUTH OF THE DALLAS- FORT WORTH AREA NEAR CORSICANA THIS
MORNING. AT 500MB A SHORTWAVE WAS ANALYZED AND IS FORECASTED TO
PUSH OFF TOWARDS THE SOUTHEAST TODAY WITH A SECONDARY SHORTWAVE
EXPECTED TO DROP DOWN THIS AFTERNOON INTO MONTANA. THIS SECONDARY
SHORTWAVE WILL DROP FAR ENOUGH SOUTH TO PUSH A FRONT THROUGH THE
AREA AROUND MIDNIGHT WEDNESDAY MORNING. WITH THE FRONTAL PASSAGE
WILL COME THE CHANCE OF RAIN. EARLY MORNING AMDAR SOUNDINGS SHOWS
A BREAKABLE CAP IN PLACE AT 800MB WITH THE SOUNDING SATURATED
BELOW 800MB. PWAT VALUES ARE ALREADY AROUND 1.3" ACCORDING TO THE
GPS MET SITE AND ARE FORECASTED TO RISE TO AROUND 1.60" AS
SUPPORTED BY THE NAM AND GFS. DURING THE AFTERNOON TODAY POCKETS
OF PVA WILL BE MOVING ACROSS THE AREA WHICH SHOULD HELP TO PROVIDE
SOME LIFT. WIDESPREAD LIFT WILL DEVELOP AS THE FRONT APPROACHES
AND WITH INSTABILITY AND MOISTURE IN PLACE RAIN LOOKS LIKELY LATE
TUESDAY NIGHT INTO WEDNESDAY MORNING. THE ONLY THING LACKING
INITIALLY TUESDAY AFTERNOON IS SUPPORT FROM THE UPPER LEVEL JET.
TUESDAY AFTERNOON THE UPPER LEVEL JET WILL TAKE ON AN ANTICYCLONIC
CURVATURE. WITH SOUTHEAST TEXAS BEING ON THE RIGHT SIDE OF THE JET
THIS WOULD FAVOR UPPER LEVEL CONVERGENCE.
THE BEST CHANCE OF RAIN LOOKS TO COME WEDNESDAY MORNING AS A
PLETHORA OF ITEMS START TO COME INTO PHASE. THE SHORTWAVE
MENTIONED ABOVE WILL INITIALLY DIVE TO THE SOUTH BEFORE HEADING
OFF TO THE EAST ALLOWING THE 850MB FRONT TO SLOW DOWN AND/ OR
STALL OVER SOUTHEAST TEXAS. THE SUBTROPICAL JET WILL ALSO LOOSE
ITS ANTICYCLONIC CURVATURE AND BEGIN TO STRENGTHEN AND MOVE OFF TO
THE EAST. THIS WOULD PUT SOUTHEAST TEXAS IN A RRQ OR DIVERGENT
REGION. PWAT VALUES ALSO REMAIN AROUND THE 1.50" MARK. AVERAGE PWAT
VALUES FOR THIS TIME OF YEAR IS ABOUT 1.15" FOR SOUTHEAST TEXAS.
TWO STANDARD DEVIATIONS ABOVE NORMAL IS AROUND 1.60". MOST OF THE
RAINFALL WILL LIKELY OCCUR WHERE THE 850MB FRONT STALLS. THE ECMWF
STALLS THE 850 FRONT IN OUR NORTHERN ZONES WEDNESDAY MORNING
BEFORE WASHING IT OUT. THE NAM AND GFS FOLLOW CLOSELY WITH THE
ECMWF.
THURSDAY MORNING LOOKS TO BE COLD AS SURFACE HIGH PRESSURE SETTLES
OVERHEAD. AS OF NOW LOOKS THAT CLOUDS WILL HANG AROUND WHICH
SHOULD HELP KEEP TEMPERATURES UP A BIT. THURSDAY AFTERNOON SURFACE
HIGH PRESSURE WILL BEGIN TO QUICKLY PULL OFF TO THE EAST AS THE
NEXT UPPER LEVEL DISTURBANCE APPROACHES THE SOUTHERN CALIFORNIA
COAST. THE GFS HOLDS UP THE DISTURBANCE WHILE THE ECMWF KEEPS A
MORE PROGRESSIVE PATTERN. THE MORE PROGRESSIVE EURO ALSO PUSHES A
FRONT THROUGH MONDAY MORNING WHILE THE GFS HOLDS THE FRONT OFF TO
LATE MONDAY EARLY TUESDAY MORNING. FOR NOW HAVE LEANED TOWARDS THE
ECMWF WHICH HAS PERFORMED WELL THIS WINTER. 23
MARINE...
WARM MOIST FLOWING OVER RELATIVELY COOL SHELF WATERS WILL MAINTAIN
PERIODS OF SEA FOG TODAY INTO THIS EVENING. PLATFORMS OFFSHORE
CONTINUE TO REPORT DENSE FOG SO WILL MAINTAIN THE DENSE FOG ADVISORY
FOR ALL WATERS THROUGH 18Z. A COLD FRONT WILL CROSS THE COASTAL
WATERS EARLY WEDNESDAY MORNING. AN ABRUPT WIND SHIFT SHOULD END THE
SEA FOG. WINDS WILL QUICKLY INCREASE AND A SMALL CRAFT ADVISORY WILL
LIKELY BE REQUIRED FOR WEDNESDAY. THE GRADIENT IS EXPECTED TO WEAKEN
WED NIGHT INTO THURSDAY. ONSHORE WINDS RETURN ON THURSDAY AND
WILL PERSIST THROUGH THE WEEKEND. WIND SPEEDS WILL GRADUALLY
INCREASE TOWARD THE END OF THE WEEK WITH MODERATE TO STRONG
ONSHORE WINDS EXPECTED NEXT WEEKEND. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 69 43 45 34 58 / 70 70 60 30 10
HOUSTON (IAH) 70 47 49 37 59 / 70 70 70 30 10
GALVESTON (GLS) 69 53 54 42 57 / 60 70 70 40 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR THE
FOLLOWING ZONES: BRAZORIA...CHAMBERS...FORT BEND...
GALVESTON...HARRIS...JACKSON...LIBERTY...MATAGORDA...
WHARTON.
GM...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...23
AVIATION/MARINE...43
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
919 PM CST WED FEB 26 2014
.UPDATE...
SCATTERED SNOW SHOWERS WILL ACCOMPANY THE ARCTIC FRONT...THEN
DECREASING CLOUDS DURING THE EARLY MORNING HOURS. HRRR SHOWING
RELATIVELY SMALL WINDOW OF SNOW SHOWER LATE EVENING TO AROUND
1 AM. HRRR RADAR REFLECTIVITY FORECAST SEEMS TO HAVE A GOOD
HANDLE ON THIS.
NO CHANGE TO WIND CHILL ADVISORY.
&&
.AVIATION/06Z TAFS/...
HRRR SHOWING RELATIVELY SMALL WINDOW OF SNOW SHOWER LATE EVENING
TO AROUND 1 AM. HRRR RADAR REFLECTIVITY FORECAST SEEMS TO HAVE A
GOOD HANDLE ON THIS. THIS ASSOCIATED WITH NEXT ARCTIC BOUNDARY AND
POTENT SHORTWAVE MOVING FROM NORTHERN WISCONSIN INTO LOWER
MICHIGAN. VFR CONDITIONS WILL BE PREVALENT MOST OF THIS PERIOD
BUT EXPECT AND AREA OF MVFR CIGS WITH THE FRONT AND ALSO LOCALIZED
MVFR TO BRIEF IFR VSBYS WITH SNOW SHOWERS. BRISK NORTHWEST WINDS
BEHIND THE FRONT.
&&
.PREV DISCUSSION... /ISSUED 242 PM CST WED FEB 26 2014/
TONIGHT AND THURSDAY - CONFIDENCE...MEDIUM
MAIN FOCUS ON THE BITTER COLD. EVENING FORECAST ISSUE WILL BE SHSN
DEVELOPMENT. SHORTWAVE ENERGY SHIFTS FROM NRN WI TO THE EASTERN LAKES.
LOW LEVEL FRONTOGENETICAL FORCING WITH RENEWED ARCTIC SURGE ALONG WITH
STEEP LOW LEVEL LAPSE RATES...SHOULD BE ENOUGH TO GENERATE A FEW-SCT
SHSN. NAM HI-RES AND HRRR BOTH AND 4KM SPC WRF ALL SHOW THIS DEVELOPMENT
THIS EVENING WITH ANY LINGERING PRECIP WRAPPING UP AROUND 6Z. ONLY A
FEW TENTHS OR SO AND SOME BLOWING TO GO ALONG WITH IT. STRONG COLD
ADVECTION SURGE AFTER 6Z CONTINUES INTO MIDDAY WITH 925 TEMPS
BOTTOMING OUT AROUND -22 TO -25C BETWEEN 12 AND 18Z. WITH AIRMASS
WELL MIXED TEMPS WILL NOT BOTTOM OUT TO THAT POTENTIAL BUT TEMPS
WILL DROP BY PURE ADVECTION. THIS IN CONCERT WITH TIGHT PRESSURE
GRADIENT WILL ALLOW WIND CHILL ADVISORY CRITERIA TO BE MET ONCE
AGAIN...SO HAVE HOISTED ONE FROM 09-18Z.
THURSDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
HIGH PRESSURE WILL SLIDE ACROSS THE AREA...WITH THE CENTER OF THE
HIGH PASSING OVER THE DUBUQUE AREA EARLY IN THE EVENING. BY 6AM
FRIDAY MORNING THE HIGH IS OVER ERN OH/WRN PA WITH THE LOW LEVEL
FLOW STARTING TO PICK UP ACROSS THE FORECAST AREA. THIS HAS BEEN
A TRICKY PERIOD WITH RESPECT TO LOW TEMPS DUE TO THE POTENTIAL FOR
STRONG RADIATIONAL COOLING. THE GFS HAS BEEN THE MOST AGGRESSIVE
OVER THE LAST FEW DAYS AND CONTINUES TO BE THE EXTREME.
WARM ADVECTION HEADING TOWARD THE AREA WILL CAUSE HIGH CLOUDS TO
SPREAD IN FROM THE WEST AFTER MIDNIGHT. JUST HOW COLD WE CAN GET
BEFORE THAT BLANKET ARRIVES IS THE BIGGEST QUESTION. THE GUIDANCE
IS NOW SUGGESTING THE COLDEST READINGS WILL BE ALONG AND JUST WEST
OF THE KETTLE MORAINE SPINE IN SOUTHEAST WISCONSIN. THE HILLS OUT
WEST OF MADISON MAY NOT TANK TOO LOW DUE TO THE EXPECTED CLOUDS
AND BREEZE KICKING IN. IN GENERAL...HAVE BACKED OFF A BIT ON WHAT
WE HAD GOING...BUT STILL WELL BELOW ZERO MOST PLACES. FAVORED
COLD SPOTS IN LOW AREAS COULD GET SURPRISINGLY COLD.
FRIDAY AND FRIDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM.
THE WARM ADVECTION MENTIONED ABOVE WILL ARRIVE AHEAD OF AN
INVERTED TROF THAT WILL ENTER WESTERN WISCONSIN FRIDAY AFTERNOON.
SNOW SHOULD BEGIN TO SPREAD INTO THE WEST TOWARD LATE MORNING AND
THE REST OF THE FORECAST AREA DURING THE DAY AND CONTINUE THROUGH
THE EVENING BEFORE EXITING TO THE EAST AFTER MIDNIGHT. WE COULD
SEE 2 TO 3 INCHES OF DRY SNOW WITH THIS.
SATURDAY INTO SUNDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM.
THE OVERALL FLOW WILL HAVE BECOME ZONAL BY SATURDAY WITH A FEW
RIPPLES MOVING THROUGH THE AREA...MAINLY AFFECTING FAR SOUTHERN
WISCONSIN. TEMPERATURES WILL ALSO MODIFY...OR WARM...FROM THEIR
DEEP CHILL...BUT STILL REMAIN BELOW NORMAL. AT THE SURFACE HIGH
PRESSURE WILL STRETCH FROM THE NORTHERN PLAINS INTO THE GREAT
LAKES. THE WEAK MID LEVEL SHORT WAVES MOVING THROUGH WILL ONLY
BRING CHANCES OF SOME FAIRLY LIGHT SNOW. NOTHING MAJOR...BUT WE/LL
HAVE A CHANCE FOR SNOW MAINLY FROM SATURDAY AFTERNOON INTO
SUNDAY...TAPERING OFF OR ENDING BY SUNDAY NIGHT.
MONDAY AND MONDAY...FORECAST CONFIDENCE IS MEDIUM.
THE HIGH OVER THE PLAINS IS EXPECTED TO DRIFT INTO THE AREA...BUT
THE GFS AND ECMWF DIFFER ON THE SPEED/STRENGTH/PLACEMENT OF THAT
HIGH BY MONDAY NIGHT. EITHER WAY...IT LOOKS DRY.
AVIATION/00Z TAFS/...HRRR/NAM HI-RES AND OTHER SYNOPTIC MODELS
SHOWING RELATIVELY SMALL WINDOW OF SHSN POTENTIAL THIS EVENING. THIS
ASSOCIATED WITH NEXT ARCTIC BOUNDARY AND POTENT SHORTWAVE MOVING
FROM NRN WI INTO LOWER MI. VFR CONDITIONS WILL BE PREVALENT MOST OF
THIS PERIOD BUT EXPECT LOCALIZED VSBYS/CIGS TO DROP TO MAINLY MVFR
WITH ANY SHSN THAT DEVELOP OR ADVECT IN. THIS WOULD MOSTLY BE IN THE
01Z-06Z TIME FRAME.
MARINE...DECIDED TO HOIST A GALE WARNING FOR MIDNIGHT THROUGH NOON.
SEEING PRETTY DECENT SIGNALS ON BUFKIT FOR A PERIOD OF GALES IN THE
WAKE OF THE LATEST ARCTIC FRONT COMING THROUGH THIS EVENING. THE GOING
SMALL CRAFT WILL LEAD UP TO THE GALE WARNING AND THEN WILL LIKELY BE
NEEDED FOR A WHILE AT THE CONCLUSION OF THE GALE WARNING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR WIZ046-
047-051-052-056>060-062>072.
LM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR LMZ643>646.
GALE WARNING UNTIL NOON CST THURSDAY FOR LMZ643>646.
&&
$$
UPDATE...HENTZ
TONIGHT/THURSDAY AND AVIATION/MARINE...COLLAR
THURSDAY NIGHT THROUGH WEDNESDAY...DAVIS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
548 PM CST WED FEB 26 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 314 PM CST WED FEB 26 2014
THE MAIN FOCUS FOR TONIGHT INTO TOMORROW IS WITH THE BLOWING SNOW
TONIGHT FOLLOWED BY COLD WIND CHILLS TOMORROW MORNING.
CURRENTLY...GUSTY SOUTHWEST WINDS ARE OCCURRING THROUGH MUCH OF
THE REGION AS A SURFACE LOW PROPAGATES EAST ACROSS THE UPPER GREAT
LAKES. THE STRONGEST WINDS HAVE BEEN ACROSS THE TYPICAL AREAS IN
SOUTHEAST MINNESOTA AND NORTHEAST IOWA WHERE SOME BLOWING AND
DRIFTING SNOW HAS ALREADY REDUCED VISIBILITIES INTO THE 1 TO 2SM
RANGE. AS THE MAIN MID LEVEL CLOSED LOW DROPS TO THE SOUTHEAST
ACROSS ONTARIO AND A COLD FRONT MOVES THROUGH THE REGION
TONIGHT...THE GRADIENT WILL TIGHTEN UP AS COLDER AIR GETS ADVECTED
IN FROM THE NORTHWEST WITH SOME LIGHT SNOW ALSO OCCURRING.
UPSTREAM OBSERVATIONS AND FORECAST SOUNDINGS FROM THE 26.12Z
NAM/GFS AND THE 26.18Z RAP SUGGEST THAT WINDS WILL COME AROUND TO
THE NORTHWEST AFTER THE FROPA AND QUICKLY INCREASE WITH SUSTAINED
WINDS IN THE 20 TO 30 MPH RANGE AND GUSTS AROUND 40 MPH FOR THIS
EVENING. THIS WILL LEAD TO MORE WIDESPREAD BLOWING AND DRIFTING
SNOW...PARTICULARLY IN SOUTHEAST MINNESOTA...NORTHEAST IOWA AND
NORTH CENTRAL WISCONSIN WHERE THE WINDS WILL BE THE HIGHEST AND
THE SNOW PACK IS THE EASIEST TO BE PUSHED AROUND.
BECAUSE OF THIS...THE MAIN CONCERN WAS WITH WHETHER THE ADVISORY
NEEDED TO BE UPGRADED TO A BLIZZARD WARNING AND ALSO WHETHER THE
ADVISORY NEEDED TO BE EXPANDED EAST AT ALL. CONFIDENCE IS NOT HIGH
ENOUGH TO GO THE BLIZZARD ROUTE AT THIS POINT BECAUSE THERE HAS
NOT BEEN A RECENT ACCUMULATING SNOW TO BLOW AROUND OVER THE TOP OF
THE OLDER SNOW PACK. SO...WHILE SNOW WILL BLOW AND CAUSE SOME
REDUCED VISIBILITIES AND SNOW COVERED ROADS...CONFIDENCE IS NOT
HIGH ENOUGH TO THINK THAT THERE WILL BE WIDESPREAD ROAD CLOSURES
AND WHITEOUT CONDITIONS.
AS THE FRONT MOVES OFF TO THE EAST...THE COLDER AIR WILL COME INTO
THE REGION AND...WHEN COMBINED WITH THE STILL GUSTY WINDS...WILL
CAUSE WIND CHILLS TO DROP DOWN INTO THE 20 TO 35 DEGREES BELOW
ZERO RANGE LATE TONIGHT THROUGH TOMORROW MORNING. TOYED WITH THE
NEED FOR A WIND CHILL WARNING...BUT BASED ON THE FORECAST...WIND
CHILLS ONLY DROP TO 35 BELOW ACROSS PORTIONS OF SE MN/NE IA/NC WI
FOR A BRIEF PERIOD TOMORROW MORNING. THUS...WENT WITH AN ADVISORY
FROM 3AM THROUGH NOON TOMORROW.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 314 PM CST WED FEB 26 2014
THE MAIN FOCUS THROUGH THE EXTENDED PERIOD IS ON THE TWO MAIN
CHANCES FOR SNOW WHICH COME ON FRIDAY AND THEN ON
SATURDAY/SATURDAY NIGHT.
THE FRIDAY SYSTEM IS SHOWING GOOD CONTINUITY IN REGARD TO
TIMING...BUT HAS SOME DIFFERENCES IN STRENGTH BETWEEN THE 26.12Z
NAM/GFS/ECMWF. THIS SNOW IS STRICTLY COMING FROM TWO FORMS OF LOW
LEVEL FORCING...THE FIRST BEING 850MB WARM AIR ADVECTION AND THEN
A FRONTOGENETIC BAND THAT APPEARS TO BE THE STRONGEST AROUND
700MB. THE INITIAL WEST TO EAST BAND OF SNOW APPEARS TO DEVELOP
ALONG THE NOSE OF THE STRONGEST LOW LEVEL WARM AIR ADVECTION
FRIDAY MORNING/EARLY AFTERNOON WITH THE FRONTOGENESIS
STRENGTHENING ALONG A SOUTHWEST TO NORTHEAST BAND FRIDAY
AFTERNOON. THE HIGHER RESOLUTION 26.12Z NAM IS COMING IN WITH SOME
STRONGER LOW LEVEL LIFT AND IS PRODUCING SOME HIGHER PRECIPITATION
TOTALS WHILE THE 26.12Z GFS/ECMWF AS WEAKER AND HAVE ABOUT HALF OF
THE QPF THAT THE NAM HAS. WITH SNOW RATIOS LOOKING LIKE THEY WILL
BE AROUND 17:1...THE GOING FORECAST OF 1 TO 4 INCHES STILL LOOKS
GOOD...BUT TRENDS WILL HAVE TO BE WATCHED FOR WHETHER THIS
FRONTOGENESIS ENDS UP BEING STRONG ENOUGH TO PRODUCE SOME LOCALLY
HIGHER AMOUNTS. THE 26.15Z SREF PLUMES SHOW THAT MOST OF THE
MEMBERS...INCLUDING THE MEAN...ARE IN THE 1 TO 4 INCH RANGE...BUT
THERE ARE SOME MEMBERS THAT ARE PUSHING THAT 6 INCH THRESHOLD.
THE NEXT ROUND OF SNOW WILL COME ON SATURDAY AND SATURDAY NIGHT
THANKS TO SOME BROAD MID LEVEL TROUGHING DIGGING DOWN INTO THE
UPPER MISSISSIPPI RIVER VALLEY AND A TIGHTENING LOW TO MID LEVEL
TEMPERATURE GRADIENT THAT LEADS TO SOME WEAK TO MODERATE
FRONTOGENESIS. STILL SOME DIFFERING OPINIONS BETWEEN THE 26.12Z
GFS/ECMWF/GEM WITH WHERE THIS SNOW ENDS UP TRACKING...BUT THE
HIGHEST PROBABILITIES LIE ACROSS NORTHEAST IOWA INTO FAR SOUTHWEST
WISCONSIN.
BEYOND THIS...THE COLD CONTINUES THROUGH THE EARLY PART OF NEXT
WEEK WITH SOME POSSIBLE LOW LEVEL WARMING COMING ON WEDNESDAY.
THE 26.12Z ECMWF SUGGESTS THAT A SYSTEM COULD COME THROUGH ON
TUESDAY/WEDNESDAY AND BRING SOME LIGHT SNOW ACROSS SOUTHEAST
MINNESOTA AND WESTERN WISCONSIN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 547 PM CST WED FEB 26 2014
A COLD FRONT...CURRENTLY LOCATED OVER THE TWIN CITIES...WILL MOVE
QUICKLY SOUTHEAST THROUGH THE AREA THIS EVENING. ALONG AND ABOUT
3 HOURS BEHIND THIS FRONT...THE CEILINGS WILL DROP INTO THE 2 TO
3K FOOT RANGE...AND THEN SKIES WILL QUICKLY CLEAR. IN ADDITION...
THERE MAY BE A BRIEF SNOW SHOWER.
AHEAD OF THIS FRONT...THE SUSTAINED WEST WINDS WILL BE IN THE 20
T0 30 KNOT RANGE WITH WIND GUSTS TO 40 KNOTS...AND THEN SHIFT TO
NORTHWEST BETWEEN 27.01Z AND 27.02Z AT BOTH TAF SITES. THERE WILL
BE LITTLE CHANGE IN THE WIND SPEEDS AFTER THE FRONTAL PASSAGE.
BLOWING SNOW ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA WILL
RANGE FROM 2 TO 4 MILES. THERE MAY BE EVEN A FEW VISIBILITIES AS
LOW AS A MILE. AS THE PRESSURE GRADIENT WEAKENS OVERNIGHT...THE
BLOWING SNOW WILL COME TO AN END ACROSS THIS AREA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL 3 AM CST THURSDAY FOR WIZ017-029.
WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR WIZ017-
029-032>034-041>044-053>055-061.
MN...WINTER WEATHER ADVISORY UNTIL 3 AM CST THURSDAY FOR MNZ079-086-
087-094-095.
WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR MNZ079-
086>088-094>096.
IA...WINTER WEATHER ADVISORY UNTIL 3 AM CST THURSDAY FOR IAZ008>010-
018-019-029.
WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR
IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
316 AM CST TUE FEB 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 315 AM CST TUE FEB 25 2014
MAIN FORECAST CONCERNS THIS PACKAGE...COLD TEMPERATURES AND NEED FOR
WIND CHILL HEADLINES TONIGHT.
DATA ANALYSIS AT 06Z HAD COLD...CANADIAN HIGH PRESSURE OVER THE
DAKOTAS WITH RIDGING ACROSS IA/IL. WV IMAGERY SHOWED THE SHORTWAVE
NEAR A KDLH-KDBQ LINE MOVING QUICKLY EAST ACROSS THE UPPER MIDWEST.
AREA RADARS SHOWING THE -SN WEST OF THIS LINE DISSIPATING/ENDING
RATHER QUICKLY EARLY THIS MORNING. TEMPS ACROSS THE AREA AS OF 06Z
MOSTLY IN THE ZERO TO 10F ABOVE RANGE. CLEARING SKIES BEHIND THE
SHORTWAVE ALREADY SPREADING INTO SOUTHWEST MN AND KMSP AREA...WITH
TEMPS FALLING TO ZERO TO -10F RANGE AND WIND CHILLS -15 TO -30.
25.00Z MODELS INITIALIZED QUITE WELL AND OFFER SIMILAR SOLUTIONS FOR
TODAY AND TONIGHT AS THE NEXT ONE DROPS ACROSS THE REGION THIS
AFTERNOON/EVENING. TREND FAVORS A TIGHTENING COMPROMISE CONSENSUS
ON THE TIMING/ STRENGTH OF THESE FEATURES. CHECK OF OBS VS. MODEL
DATA AT 06Z SHOWED MODELS TO BE GOOD WITH THE -SN MOVING/
DISSIPATING ACROSS THE AREA EARLY THIS MORNING. PER WV IMAGERY
MODELS APPEARED GOOD WITH THE SHORTWAVE DETAILS OVER NOAM/EASTERN
PAC...WITH NO ONE MODEL LOOKING BETTER THAN THE OTHERS. MODEL 850MB
RH PROGS DOING A DECENT JOB WITH THE DECREASING CLOUDS SPREADING
SOUTHEAST ACROSS MN EARLY THIS MORNING...WHILE ALL MODELS WERE TOO
ROBUST WITH THE POST- TROUGH 925MB MOISTURE ACROSS MUCH OF MN/
NEARBY AREAS. GIVEN THE TIGHT CONSENSUS...FAVORED A MODEL/ENSEMBLE
BLEND WITH SHORT-TERM FCST CONFIDENCE ON THE GOOD SIDE.
FOR THE SHORT TERM...ROUNDS OF LOW LEVEL COLD ADVECTION WILL SPREAD
ACROSS THE AREA THIS MORNING BEHIND DEPARTING WAVE NUMBER ONE AND
THIS EVENING BEHIND WAVE/TROUGH NUMBER TWO. FOLLOWING SO CLOSELY
BEHIND THE STRONGER WAVE FROM EARLY THIS MORNING...THE SECOND
SHORTWAVE HAS LIMITED MOISTURE ABOVE 850MB TO WORK WITH AND
TODAY/TONIGHT CONTINUE TO TREND DRY. SOME STEEPER LOW LEVEL LAPSE
RATES WITH MIXING TO 900-875MB INDICATED FOR THIS AFTERNOON...ALONG
WITH SOME 925MB MOISTURE. SCT STRATO-CU EXPECTED ACROSS THE AREA FOR
THE MID/LATE AFTERNOON HOURS. SOME STRONGER WINDS ACROSS MUCH OF THE
AREA FOR THIS AFTERNOON WITH A TIGHTER PRESSURE GRADIENT AND THE
DEEPER MIXING. CONTINUED THE MENTION OF SOME BLOWING/DRIFTING SNOW
ESPECIALLY ACROSS THE OPEN AREAS OF SOUTHEAST MN/NORTHEAST IA.
LOW TEMPS TRICKY TONIGHT. COLDEST OF THE LOW LEVEL AIR MOVES
ACROSS THE FCST AREA AROUND 06Z WITH 925MB TEMPS IN THE -21C TO
-23C RANGE...WITH LOW LEVEL WARM ADVECTION SPREADING INTO THE AREA
BY 12Z. MDT GRADIENT WINDS OF 10-15MPH LOOK TO REMAIN OVER THE
THRU MIDNIGHT...ONLY DIMINISHING LATE AS A WEAK SFC RIDGE AXIS
SLIDES ACROSS THE AREA. MIXED 925MB TEMPS WOULD ONLY SUPPORT LOWS
IN THE ZERO TO -10F RANGE...BUT WITH MOSTLY CLEAR SKIES AND
POTENTIAL FOR SOME DECOUPLING LATE...LEFT LOWS MOSTLY IN THE -10F
TO -15F RANGE. SUB ZERO TEMPS COMBINED WITH THE WINDS OF 10-15MPH
PRODUCE WIDESPREAD WIND CHILLS IN THE -20 TO -35 RANGE LATE THIS
EVENING THRU MUCH OF WED MORNING THUS WILL BE ISSUED A WIND CHILL
ADVISORY FOR 03Z TO 17Z WED. USED THE BLEND OF GUIDANCE HIGHS/LOWS
FOR TODAY/TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 315 AM CST TUE FEB 25 2014
MAIN FORECAST CONCERNS FOR WEDNESDAY THROUGH THURSDAY NIGHT...
CONTINUED COLD TEMPERATURES...-SN CHANCES WED AFTERNOON/EVENING.
MODEL RUNS OF 25.00Z REMAIN IN RATHER GOOD AND IMPROVING AGREEMENT
FOR THE WED THRU THU NIGHT PERIOD. TREND IS STRONGER WITH A
SHORTWAVE TROUGH TO DROP ACROSS THE GREAT LAKES WED AFTERNOON/NIGHT
AND DRIVE ANOTHER ARCTIC FRONT SOUTH ACROSS THE REGION. GIVEN THE
TIGHT AND TIGHTENING MODEL CONSENSUS...FCST CONFIDENCE IN THE WED
THRU THU NIGHT PERIOD IS GOOD.
THIS NEXT STRONGER SHORTWAVE TROUGH DROPS SOUTH TOWARD LK SUPERIOR
WED WITH FALLING SFC PRESSURES AND A TIGHTENING PRESSURE GRADIENT AS
THE SFC TROUGH WITH THE SHORTWAVE MOVES SOUTH INTO THE REGION.
RATHER STRONG 925-850MB WARM ADVECTION SPREADS ACROSS THE FCST
AREA WED WITH 925MB TEMPS WARMING INTO THE -10C TO -14C RANGE BY
LATE AFTERNOON. TIGHTER PRESSURE GRADIENT LOOKS TO RESULT IN WEST
TO SOUTHWEST WINDS OF 15-30MPH AND GUSTY FOR THE
AFTERNOON...RESULTING IN WHAT SHOULD BE GOOD MIXING AND A DIURNAL
TEMP RISE OF AS MUCH AS 30F OR MORE AT SOME LOCATIONS. ENOUGH WIND
FOR BLOWING/DRIFTING SNOW AGAIN IN THE OPEN COUNTRY AREAS WED
AFTERNOON/EVENING. WITH DITCHES ALREADY FULL OF DRIFTED
SNOW...SOME ROADS LIKELY TO BE IMPACTED BY ANY DRIFTING WED
AFTERNOON. WIND CHILLS WILL REMAIN IN THE -20 TO -35 RANGE MUCH OF
THE MORNING WITH THE TEMP RISE BEING OFFSET BY THE INCREASING
WINDS. WIND CHILLS DONT LOOK TO RISE ABOVE -20 UNTIL TEMPS WARM TO
AROUND +5F. SOME INCREASE OF 925-700MB MOISTURE INDICATED WITH
APPROACH/PASSING OF THE LOWER LEVEL TROUGH/FRONT WED
AFTERNOON/EVENING. MORE SATURATION INDICATED IN THE COOLER COLUMN
OVER THE NORTHEAST END OF THE FCST AREA AND INCLUDED A SMALL -SN/
FLURRY CHANCE THOSE AREAS WED AFTERNOON/EVENING. ARCTIC AIR SURGES
BACK INTO THE AREA WED NIGHT BEHIND THIS TROUGH/FRONT WITH 925MB
TEMPS BACK IN THE -24C TO -28C RANGE BY 12Z THU. GRADIENT WINDS IN
THE 10-20MPH RANGE WED NIGHT...TO KEEP THE BOUNDARY LAYER MIXED
AND LOWS FROM BOTTOMING OUT TOO FAR...BUT SENDS WIND CHILLS BACK
INTO THE -20 TO -35 RANGE BY 12Z THU WITH ANOTHER WIND CHILL
ADVISORY NEEDED LATE WED NIGHT/THU MORNING.
LOW LEVEL COLD ADVECTION CONTINUES THU WITH LITTLE DIURNAL TEMP
RECOVERY. MIXED 925MB TEMPS ONLY SUPPORT MOST HIGHS IN THE ZERO TO
+5F RANGE THU. CENTER OF THE ARCTIC HIGH SETTLES ACROSS THE AREA THU
NIGHT. SOME 850MB WARM ADVECTION PROGGED TO SPREAD IN LATE THU
NIGHT...BUT STRONG RADIATIONAL COOLING EXPECTED WED NIGHT WITH A
DECOUPLED BOUNDARY LAYER AND CLEAR/MOSTLY CLEAR SKIES AND THE ARCTIC
AIRMASS OVER THE AREA. SOME LOWS IN THE NORMALLY COLDER SHELTERED
LOCATIONS OF CENTRAL/NORTH CENTRAL WI COULD APPROACH -30F. SOME
INCREASE OF CLOUDS WEST OF THE MS RIVER LATE THU NIGHT MAY KEEP LOWS
A BIT WARMER THERE. ALL IN ALL...FAVORED A BLEND OF THE GUIDANCE
HIGHS/LOWS FOR WED THRU THU NIGHT BUT DID TREND TOWARD COLDER OF
GUIDANCE LOWS THU NIGHT ALONG/NORTHEAST OF I-94.
FOR FRIDAY THROUGH MONDAY.../DAYS 4 TO 7/...
MAIN FORECAST CONCERNS THIS PERIOD...SNOW CHANCES FRI/SUN/MON...
COLD TEMPERATURES THRU THE PERIOD.
MEDIUM RANGE MODEL RUNS OF 25.00Z IN SURPRISINGLY GOOD AGREEMENT FRI
INTO SAT NIGHT AS THE PATTERN TRANSITIONS TO MORE WESTERLY THRU SAT
THEN TOWARD SOUTHWESTERLY OVER THE CENTRAL CONUS SAT NIGHT. MODEL
DIFFERENCES INCREASE THRU SUN/MON WITH STRENGTH/TIMING OF SHORTWAVE
TROUGHS THRU THE FLOW AND ACROSS THE CENTRAL CONUS. RUN-TO-RUN
CONSISTENCY ON THE LOWER SIDE BY SUN/MON SO NO ONE MODEL LOOKS
FAVORED OVER THE OTHERS. SIDED WITH THE MODEL/ENSEMBLE CONSENSUS...
WITH FCST CONFIDENCE IN -SN CHANCES AVERAGE FRI/SAT THEN BELOW
AVERAGE SUN/MON. CONFIDENCE IS GOOD FOR TEMPS TO REMAIN BELOW NORMAL.
AN INCREASE OF MOISTURE...FROM THE SYSTEM THAT COMES INTO CA WED/WED
NIGHT...ACCOMPANIES THE LOWER LEVEL WARM ADVECTION THAT SPREADS
ACROSS THE AREA FRI...MORE ROBUST IN THE GFS/CAN-GEM SOLUTIONS. 20-
35 PERCENT -SN CHANCES ACROSS MAINLY THE SOUTH HALF OF THE FCST AREA
ON FRI LOOK REASONABLE. SOME MOISTURE FROM THE SYSTEM THAT CRASHES
ONSHORE INTO CA FRI/FRI NIGHT LOOKS TO OVERRUN THE COLD DOME OVER
THE AREA ALREADY FRI AFTERNOON/NIGHT. SMALL -SN CHANCES THESE
PERIODS ALSO REASONABLE FOR NOW PENDING A BETTER CONSENSUS ON WHAT
ARE DAY 5 DETAILS. BY DAYS 6/7 MODEL DIFFERENCES WOULD HAVE LARGE
IMPACTS ON THE SENSIBLE WEATHER. FASTER ECMWF WOULD LIMIT -SN
CHANCES TO SUN WITH ARCTIC HIGH PRESSURE BUILDING BACK IN FOR MON.
SLOWER GFS WOULD KEEP -SN IN THE FCST BOTH SUN/MON...WITH SOME
MODERATION OF TEMPS THESE PERIODS. AGAIN WITH NO ONE MODEL FAVORITE
AND LOWER CONFIDENCE BY SUN/MON STAYED WITH THE MODEL/ENSEMBLE
CONSENSUS FOR BOTH TEMPS AND -SN CHANCES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1136 PM CST MON FEB 24 2014
THE LIGHT SNOW WITH THE SHORT WAVE TROUGH HAS BEEN HOLDING TOGETHER
THIS EVENING AND MAKING STEADY EASTWARD PROGRESS. THE VISIBILITY IN
THE SNOW BRIEFLY DROPS DOWN TO MVFR FOR A COUPLE OF HOURS WHILE THE
CEILINGS ARE A LITTLE MORE VARIABLE...EITHER STAYING VFR OR ALSO
DIPPING TO MVFR. WILL SHOW THE SNOW MOVING OUT OF KRST SHORTLY AFTER
06Z AND AROUND 08Z AT KLSE WHICH IS VERY SIMILAR TO THE TRENDS OF
THE LATEST COUPLE RUNS OF THE HRRR WHICH SEEMS TO HAVE A PRETTY GOOD
HANDLE ON THE SNOW. IR SATELLITE SHOWS THE BACK EDGE OF THE CLOUDS
ALREADY ABOUT HALF TO THREE QUARTERS OF THE WAY ACROSS MINNESOTA.
WILL SHOW THE CLOUDS CLEARING OUT OF KRST BEFORE 12Z AND JUST AFTER
AT KLSE...BUT CONCERNED THAT THESE TRENDS COULD BE TOO SLOW. ONCE
THE CLOUDS CLEAR OUT...VFR CONDITIONS FOR THE REST OF THE PERIOD
WITH NORTHWEST WINDS BETWEEN 10 AND 15 KNOTS AS HIGH PRESSURE SLIDES
SOUTHEAST FROM THE CANADIAN ROCKIES INTO THE MIDWEST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY FROM 8 PM THIS EVENING TO 11 AM CST
WEDNESDAY FOR WIZ017-029-032>034-041>044-053>055-061.
MN...WIND CHILL ADVISORY FROM 8 PM THIS EVENING TO 11 AM CST
WEDNESDAY FOR MNZ079-086>088-094>096.
IA...WIND CHILL ADVISORY FROM 8 PM THIS EVENING TO 11 AM CST
WEDNESDAY FOR IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION.....04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1136 PM CST MON FEB 24 2014
.SHORT TERM...(TONIGHT AND TUESDAY)
ISSUED AT 215 PM CST MON FEB 24 2014
WATERVAPOR SATELLITE IMAGERY DEPICTING A SHORTWAVE TRACKING
SOUTHEAST OVER THE NORTHERN PLAINS. A BAND OF SNOW EXTENDS FROM THE
PLAINS INTO WESTERN IA...FOCUSED ALONG A REGION OF LOW LEVEL
FRONTOGENETICS. HRRR/RAP13/NAM12 KEEP THE MAIN BODY OF SNOW ON A
SOUTHEAST TRACK...ACROSS WESTERN/SOUTHERN IA. SOME LIGHT SNOW
ASSOCIATED WITH THE SHORTWAVE OVER SD THOUGH...AND EXPECT THIS TO
WORK OVER THE FORECAST AREA THIS EVENING...EXITING OVERNIGHT. COULD
BE SOME MINOR ACCUMS...GENERALLY LESS THAN 1/2 INCH...SOUTH OF I-90.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 215 PM CST MON FEB 24 2014
ARCTIC AIR WILL TAKE UP RESIDENCE ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY YET AGAIN...BRINGING BITTER TO DANGEROUSLY COLD TEMPERATURES.
ECMWF 850 MB TEMP ANOMALIES RUN FROM -2 TO -3 THROUGH THE WEEK.
AMPLIFIED UPPER LEVEL RIDGE OVER THE WEST COAST WILL GIVE ARCTIC AIR
EASY ACCESS SOUTH...AND ALSO PROVIDE AN AVENUE FOR VARIOUS BITS OF
UPPER LEVEL ENERGY. WITH A SFC HIGH EXPECTED TO BE OVERHEAD TUE/THU
NIGHTS...WED/FRI MORNINGS LOOK TO BE THE COLDEST OF THE WEEK. ANY
KIND OF STIRRING IN THE WINDS WILL MAKE IT FEEL 10 TO 15 DEGREES
COLDER. WIND CHILL ADVISORIES WILL BE NEEDED FOR WED/THU MORNING.
WINDS MUCH LESS FRI MORNING - SO SOME UNCERTAINTY FOR AN ADV THERE.
ANY WAY YOU LOOK AT IT...FEBRUARY IS GOING TO END ON A VERY COLD
NOTE.
THERE IS SOME HOPE BY THE END OF THE WEEKEND...AS UPPER LEVEL
TROUGHING IS EXPECTED TO PUSH INTO THE WEST COAST...WHICH WOULD HELP
BREAK DOWN THE RIDGE. OUR FLOW WOULD BECOME A BIT MORE ZONAL...
PUSHING THE VERY COLD AIR BACK NORTH. TEMPS WOULD MODERATE A
BIT...BUT STILL STAY BELOW NORMAL.
AS FOR PCPN CHANCES...GFS/ECMWF/NAM IN DECENT CONSENSUS WITH TAKING
PIECES OF SHORTWAVE ENERGY EITHER NORTH OR SOUTH OF THE HEART OF THE
FORECAST AREA. SOME GLANCING BLOWS ARE POSSIBLE...AND WITH
VARIABILITY IN THIS KIND OF FLOW...PLACEMENT AND TIMING OF ANY FEATURE
COULD CHANGE.
FIRST SHORTWAVE THAT COULD BRING SOME LIGHT SNOW COMES WED
NIGHT...WITH ALL THE MODELS DRIVING A TROUGH ACROSS THE NORTHERN
GREAT LAKES. GOOD AMOUNT OF QG CONVERGENCE IN THE 850-300 MB
LAYER...HOLDING MOSTLY ACROSS NORTHERN PORTIONS OF MN/WI. DECENT
SWATH OF LOW LEVEL WARM AIR ADVECTION SWEEPING AHEAD OF THE
ASSOCIATED COLD FRONT DURING THE DAY WED. ENOUGH DYNAMICS FOR
SNOW...BUT SATURATION IS GOING TO BE A LIMITING FACTOR. RH FIELDS
AND NORTHEAST-SOUTHWEST RUNNING X-SECTIONS SHOW A DEARTH OF
MOISTURE...EITHER CONFINED TO THE MID LEVELS...OR BELOW 850 MB. NOT
FAVORABLE FOR PCPN PRODUCTION. THAT SAID...LOCATIONS ALONG AND
NORTH/EAST OF I-94 SHOULD AT LEAST HAVE A SHOT FOR SOME LIGHT
SNOW/FLURRIES. ACCUMS WOULD BE MINIMAL.
BOTH MODELS WANT TO BRING A SHORTWAVE WEST-EAST OVER THE SOUTHERN
PLAINS FRI. NOT MUCH IMPACT FROM THIS FEATURE ITSELF...BUT WARM AIR
ADVECTION AND A DEFORMATION REGION NORTH OF THE WAVE COULD RESULT IN
SOME LIGHT SNOW FOR NORTHEAST IA/SOUTHERN WI. ANOTHER SHORTWAVE IS
SLATED TO DRIVE ACROSS IA SAT NIGHT/SUN...WHICH COULD BRING SOME
LIGHT SNOW TO AREAS SOUTH OF I-90. WILL SIDE WITH CONSENSUS POPS FOR
NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1136 PM CST MON FEB 24 2014
THE LIGHT SNOW WITH THE SHORT WAVE TROUGH HAS BEEN HOLDING
TOGETHER THIS EVENING AND MAKING STEADY EASTWARD PROGRESS. THE
VISIBILITY IN THE SNOW BRIEFLY DROPS DOWN TO MVFR FOR A COUPLE OF
HOURS WHILE THE CEILINGS ARE A LITTLE MORE VARIABLE...EITHER
STAYING VFR OR ALSO DIPPING TO MVFR. WILL SHOW THE SNOW MOVING OUT
OF KRST SHORTLY AFTER 06Z AND AROUND 08Z AT KLSE WHICH IS VERY
SIMILAR TO THE TRENDS OF THE LATEST COUPLE RUNS OF THE HRRR WHICH
SEEMS TO HAVE A PRETTY GOOD HANDLE ON THE SNOW. IR SATELLITE SHOWS
THE BACK EDGE OF THE CLOUDS ALREADY ABOUT HALF TO THREE QUARTERS
OF THE WAY ACROSS MINNESOTA. WILL SHOW THE CLOUDS CLEARING OUT OF
KRST BEFORE 12Z AND JUST AFTER AT KLSE...BUT CONCERNED THAT THESE
TRENDS COULD BE TOO SLOW. ONCE THE CLOUDS CLEAR OUT...VFR
CONDITIONS FOR THE REST OF THE PERIOD WITH NORTHWEST WINDS BETWEEN
10 AND 15 KNOTS AS HIGH PRESSURE SLIDES SOUTHEAST FROM THE
CANADIAN ROCKIES INTO THE MIDWEST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1023 PM MST MON FEB 24 2014
.UPDATE...
ISSUED AT 714 PM MST MON FEB 24 2014
HAD TO DO AN UPDATE ON MIN TEMPERATURES THIS EVENING...ESPECIALLY
EAST OF THE LARAMIE RANGE. TEMPERATURES AT THE OFFICE HERE IN
CHEYENNE ALREADY AT 9 AND DROPPING WITH SINGLE DIGITS IN THE
PANHANDLE. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 345 PM MST MON FEB 24 2014
FRONT HAS PASSED ACROSS THE PLAINS WITH NORTHERLY WINDS AND LOW
CLOUDS FILLING IN BEHIND IT. THERE WAS A DRAMATIC DROP IN TEMPS
ALONG THE COLORADO BORDER WITH THE FROPA...AS PREFRONTAL
DOWNSLOPING WESTERLY WINDS WERE REPLACED BY THE COLD NORTHERLIES.
SOME LIGHT SNOW HAS BEEN REPORTED AT CHADRON OVER THE PAST FEW
HOURS WITH GENERALLY DEEPER LAYER LIFT STRETCHING FROM THE
NORTHERN PANHANDLE OFF TO THE NORTHEAST. COULD BE SOME LIGHT SNOW
SHOWERS ACROSS THE PLAINS OVERNIGHT WITH LLVL LIFT...BUT
ACCUMULATIONS WILL BE REALLY LIGHT. THE OTHER STORY THIS AFTN IS
THAT THE WINDS HAVE FINALLY WEAKENED ACROSS THE ARLINGTON AREA AND
LARAMIE VALLEY. STILL COULD BE SOME GUSTS TO 40-50 MPH THROUGH
SUNSET BUT WITH RAPID PRESSURE RISES TO THE EAST OF THE LARAMIE
RANGE AND THE 700MB CAG-CPR GRADIENT DROPPING TO 40 METERS BY 12Z
TUES...NOT EXPECTING THE STRONG WESTERLY WINDS TO RETURN TO THE
WIND PRONE AREAS THROUGH AT LEAST THE SHORT TERM.
THE MODELS STILL SHOW A SHORTWAVE DROPPING SOUTHEASTWARD FROM
MONTANA INTO NEBRASKA DURING THE DAY ON TUESDAY. THERE WILL BE
ABOUT A 6-HR PERIOD FROM LATE TUESDAY MORNING INTO THE AFTERNOON
THAT SNOW WILL BE LIKELY ACROSS THE CWA. THIS IS SHAPING UP TO BE
A WIDESPREAD LIGHT SNOWFALL EVENT...WITH MANY LOWER ELEVATION
LOCATIONS GETTING 1 TO 4 INCHES. THE SHORT DURATION OF THE EVENT
ALONG WITH WEAKER UPWARD MOTION THROUGH THE LOW AND MID LEVELS
(COMPARED TO THIS PAST WEEKEND EVENT) SHOULD KEEP MOST AREAS BELOW
ADVISORY LEVEL AMOUNTS. THE MTNS WILL GENERALLY SEE 5 TO 7 INCHES.
SNOW QUICKLY ENDS BY EVENING AS SUBSIDENCE KICKS IN BEHIND THE
SHORTWAVE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 345 PM MST MON FEB 24 2014
THE MEDIUM RANGE WILL BE CONSIST OF THE TALE OF TWO AIR MASSES. THE
FIRST AIR MASS WILL YIELD A RELATIVELY BENIGN PERIOD WEDNESDAY AND
THURSDAY AS NORTHWEST FLOW DRIES AND BECOMES LESS CYCLONIC. AT THE
SFC...THE QUASISTATIONARY BOUNDARY WILL RETREAT TO THE EAST BOTH OF
THESE DAYS AS WELL. SO ALTHOUGH SOMEWHAT BREEZY...EXPECT MOSTLY DRY
CONDITIONS TO PREVAIL FOR BOTH DAYS WITH HIGH TEMPERATURES GENERALLY
IN THE 40S OVR SE WY AND 30S OVR THE WRN NEBRASKA PANHANDLE.
THIS ALL WILL BEGIN TO CHANGE ON THURSDAY AS SHORTWAVE ENERGY DIVES
SOUTHEAST THRU THE FOUR CORNERS. MOISTURE ASSOCIATED WITH THIS FTR
WILL BRING A RETURN TO PRECIP CHANCES AREAS ALONG AND WEST OF THE
LARAMIE RANGE. ADDITIONALLY...SFC PRESSURE FALLS TO THE SOUTH
COMBINED WITH THE NEXT ARCTIC PINWHEELING AROUND THE HUDSON BAY LOW
WILL RESULT IN STRONG LLVL CAA AND RESULTANT FROPA. 12Z MODELS ARE
CONSISTENT IN FROPA TIMING OCCURRING FRIDAY MORNING. THIS COLD FRONT
WILL AGAIN PULL UP STATIONARY NR THE DIVIDE AS THE ARCTIC AIR MASS
HANGS UP ON THE TERRAIN. ALOFT...WEST/SOUTHWEST FLOW FILLED WITH
PACIFIC MOISTURE WILL PERSISTENTLY OVER-RUN THIS LLVL COLD DOME
SETTING THE STAGE FOR WHAT LOOKS TO BE A SNOWY PERIOD BEGINNING LATE
THURSDAY THROUGH SATURDAY NIGHT. DETAILS ARE STILL TOO BLURRY TO
START TALKING ABOUT ACCUMULATIONS JUST YET...BUT GIVEN THE EVENTS
LONG DURATION WOULD EXPECT MODERATE SNOW AMOUNTS AT A MINIMUM. HAVE
CONTINUED TO BOOST SNOW CHANCES DURING THIS PERIOD PRETTY MUCH
AREA-WIDE AS CONFIDENCE GROWS. THE OTHER IMPACT FROM FROPA WILL BE
THE VERY COLD AIR ASSOCIATED WITH THE ARCTIC AIR MASS. AREAS
NORTHEAST OF THE NORTH PLATTE RIVER VALLEY WILL ONLY REACH THE LOWER
20S ON FRIDAY AND SINGLE DIGITS ON SATURDAY AND SUNDAY.
THE PATTERN WILL BECOME LESS ACTIVE AND MORE ZONAL FOR LATE IN THE
WEEKEND AND EARLY NEXT WEEK. HOWEVER...DID KEEP SMALL SNOW CHANCES
GOING FOR THIS LATTER PERIODS AS THE MODELS ARE STILL MEANDERING
THAT BOUNDARY IN THE VICINITY OF THE FRONT RANGE. TEMPERATURES TRY
TO EVER SO SLOWLY WARM MONDAY...BUT WILL STILL REMAIN BELOW
SEASONAL AVERAGES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY EVENING)
ISSUED AT 1017 PM MST MON FEB 24 2014
TRICKY FORECAST CONTINUES OVERNIGHT. WINDS ARE PRETTY MUCH CALM
HERE AT KCYS WITH SOUTHEASTERLY WINDS JUST TO OUR SOUTH AND OVER
AT KLAR. SHOULD OUR WINDS TURN SOUTHEAST HERE AT KCYS...WE WILL GO
DOWN ONCE AGAIN IN UPSLOPING FLOW. HRRR KEEPS LOWER CEILINGS DOWN
ON THE COLORADO SIDE OF THE WYO HILL...BUT DO THINK THERE IS A
SMALL WINDOW WHERE KCYS COULD SEE A SOUTHEAST WIND FOR A TIME.
ADDED TEMPO IFR CONDITIONS HERE AT KCYS BASED ON THESE WINDS. SOME
MVFR OUT IN THE PANHANDLE NEAR CHADRON AND SIDNEY OVERNIGHT.
ATTENTION TURNS TO LOWERING CONDITIONS TUESDAY AS SNOW BECOMES
WIDESPREAD. BEING OBSERVED ON MOSAIC RADAR RIGHT NOW OVER
SOUTHWESTERN MONTANA AND NORTHWESTERN WYOMING. THIS IS FROM A
DISTURBANCE THAT WILL RIDE DOWN ALONG THE FRONT TO OUR WEST. DO
THINK MOST AIRPORTS WILL SEE A PERIOD OF IFR CONDITIONS TUESDAY
MID MORNING THROUGH THE AFTERNOON HOURS.
&&
.FIRE WEATHER...
ISSUED AT 345 PM MST MON FEB 24 2014
NO FIRE WEATHER CONCERNS THROUGH THE END OF THE WEEK. WIDESPREAD
SNOW COVER STILL EXISTS ACROSS MUCH OF THE NEBRASKA PANHANDLE.
ANOTHER ROUND OF SNOW IS EXPECTED TUESDAY MORNING THROUGH THE
EVENING. TEMPERATURES WILL GENERALLY BE BELOW NORMAL THROUGH THE
UPCOMING WEEKEND.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLAYCOMB
SHORT TERM...FINCH
LONG TERM...HAHN
AVIATION...CLAYCOMB
FIRE WEATHER...FINCH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
324 AM EST THU FEB 27 2014
.UPDATE...
THE SYNOPSIS...NEAR TERM...AND SHORT TERM SECTIONS HAVE BEEN UPDATED
BELOW.
&&
.SYNOPSIS...
ISSUED AT 324 AM EST THU FEB 27 2014
A COLD FRONT WILL USHER IN ANOTHER ROUND OF ARCTIC AIR TODAY.
ANOTHER FRONT WILL BRING CHANCES FOR SNOW FRIDAY NIGHT INTO
SATURDAY...BUT A MORE POTENT SYSTEM WILL BRING A WINTRY MIX OF
PRECIPITATION SATURDAY NIGHT INTO MONDAY. TEMPERATURES WILL BE BELOW
AVERAGE FOR THE NEXT WEEK.
&&
.NEAR TERM /TODAY/...
ISSUED AT 324 AM EST THU FEB 27 2014
COLD FRONT REMAINS TO THE WEST AT THIS MOMENT AND TEMPERATURES
ACROSS CENTRAL INDIANA ARE RISING AHEAD OF THE FRONT. FRONT WILL BE
THROUGH THE AREA BY THE START OF THE TODAY PERIOD /7 AM/...BUT THE
QUESTION IS HOW MUCH OF THE COLD AIR WILL HAVE LOWERED TEMPERATURES
FROM THEIR RELATIVELY HIGHER LEVELS AT THE MOMENT.
FEEL THAT A BLEND OF MODELS CAPTURES CURRENT TRENDS BEST AND WILL
USE FOR TEMPERATURE FORECASTS TODAY. TEMPERATURES WILL FALL SOME
THIS MORNING IN THE STRONG COLD ADVECTION BEFORE REBOUNDING SOME
THIS AFTERNOON WITH SOME SUNSHINE EXPECTED. USING THE MODEL BLEND
FOR HIGHS ENDS UP CLOSE TO THE MET MOS.
THERE ARE SOME CLOUDS NEAR THE FRONT ITSELF AND BEHIND THE FRONT IN
THE COLD ADVECTION. THESE WILL DIMINISH THROUGH THE DAY AS CORE OF
COLD AIR BEGINS TO MOVE OFF TO THE EAST. PARTLY TO MOSTLY SUNNY WILL
COVER IT.
GUSTY WINDS AND A FEW FLURRIES ACCOMPANY THE FRONT. FLURRIES SHOULD
BE OUT OF THE AREA BY 12Z...BUT GUSTY WINDS WILL CONTINUE TODAY
ESPECIALLY THIS MORNING.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 324 AM EST THU FEB 27 2014
FOCUS IS ON PRECIPITATION CHANCES THROUGH THE PERIOD. MODELS ARE
CLOSE ENOUGH THAT A BLEND CAN BE USED.
HIGH PRESSURE WILL PROVIDE MOSTLY CLEAR SKIES TONIGHT ALONG WITH
LIGHT /BUT NOT CALM/ WINDS. THESE WILL ALLOW A COLD NIGHT...BUT FEEL
THAT MAV MOS IS JUST TOO COLD WITH NO SNOW COVER AND SOME LIGHT
WINDS. WENT CLOSER TO MET MOS.
CLOUDS WILL INCREASE ON FRIDAY AHEAD OF THE NEXT SYSTEM. MOST AREAS
WILL REMAIN DRY AS FORCING DOES NOT ARRIVE UNTIL LATE IN THE DAY.
TRIMMED BACK SLIGHT CHANCE POPS TO JUST THE FAR SOUTHWEST FORECAST
AREA...AND ONLY WENT WITH THEM AFTER 21Z. WENT WARMER THAN THE
CONTINUED COLD MAV MOS...CLOSER TO THE MET.
FORCING FRIDAY NIGHT DOES NOT LOOK AS GOOD TODAY AS IT DID
YESTERDAY. BETTER FORCING LOOKS TO BE CLOSER TO AN UPPER TROUGH THAT
MOVES ACROSS KENTUCKY AND TENNESSEE. THUS CUT POPS BACK TO CHANCE
CATEGORY NORTH WHILE KEEPING LOW LIKELY POPS SOUTH. WENT SNOW AS
PRECIPITATION TYPE...BUT WOULD NOT BE SURPRISED TO SEE A LITTLE RAIN
AT ONSET ACROSS THE FAR SOUTH.
ON SATURDAY A COLD FRONT WILL MOVE INTO THE AREA...BUT LITTLE
FORCING IS AROUND WITH IT. THUS CONTINUED THE SLIGHT CHANCE POPS.
COLD AIR WILL NOT MOVE IN RIGHT BEHIND THE FRONT...SO READINGS WILL
HAVE A CHANCE TO GET RELATIVELY WARM. WENT WITH A MODEL BLEND.
GOOD FRONTOGENETICAL FORCING DEVELOPS BEHIND THE FRONT SATURDAY
NIGHT ALONG WITH FORCING FROM AN UPPER JET. WENT LIKELY POPS ALL
AREAS. PRECIPITATION TYPE COMES INTO QUESTION WITH WARMER AIR AT THE
SURFACE INITIALLY FOLLOWED BY HOW MUCH WARM AIR WORKS IN ALOFT
OVERNIGHT. WITH PLENTY OF UNCERTAINTY AROUND...DECIDED TO KEEP
MAINLY SNOW NORTH...AND MIX OF FREEZING RAIN AND SNOW SOUTH.
/SREF SHOWS A GOOD EXAMPLE OF THIS UNCERTAINTY. 03Z SREF MEAN SHOWS
SURFACE TEMPERATURES ABOVE 32 THROUGH MUCH OF THE NIGHT ACROSS MUCH
OF CENTRAL INDIANA. OTHER MODELS ARE COLDER AND LOOK REASONABLE
GIVEN EXPECTED LOCATION OF UPPER JET ENTRANCE REGION AND
FRONTOGENETICAL FORCING/.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
ISSUED AT 212 AM EST THU FEB 27 2014
MODELS ARE ACTUALLY FAIRLY CLOSE ON THE SYNOPTIC SCALE AND ALLBLEND
INITIALIZATIONS REFLECT WELL THE TRENDS OF THE LARGE SYSTEM
PROJECTED TO MOVE THROUGH THE REGION SUNDAY AND SUNDAY NIGHT.
THE FOCUS OF THIS PERIOD COMES DOWN TO PRECIPITATION TYPE SUNDAY
AND SUNDAY NIGHT AND IT COMES DOWN TO TEMPERATURES/THICKNESSES
WHICH AS OF LATE HAVE BEEN TRENDING COLDER. AS OF THIS MODEL RUN
THIS MEANS BETTER CHANCES FOR SNOW AS OPPOSED TO FREEZING RAIN OR
SLEET. BEST CHANCE FOR SNOW LIES ACROSS THE NORTHERN HALF OF THE
COUNTY WARNING AREA...BUT A WARM INTRUSION TO OUR SOUTH COULD STILL
BRING CHANCES FOR SLEET AND FREEZING RAIN (SOUTH OF I-70) INTO THE
FORECAST.
DEVELOPED FORECAST TOWARD THIS COLDER TREND HOWEVER WITHOUT
COMPLETELY FLIP-FLOPPING BACK AND FORTH BETWEEN FREEZING RAIN AND
SNOW. THE NORTHERN COUNTIES LOOK LIKE AN ALL SNOW EVENT...WHILE
AROUND I-70 APPEARS SNOW WILL BE THE MAIN PRECIP-TYPE WITH CHANCES
FOR SLEET OR FREEZING RAIN POSSIBLE AT TIMES. AND THEN FOR THE
SOUTHERN TIER OF COUNTIES SLEET OR FREEZING RAIN WITH POSSIBLY SOME
CHANCES FOR SNOW LOOK TO BE THE PRECIP-TYPE.
THIS EVENT SHOULD BE WINDING DOWN ON MONDAY...WITH ONLY LOW CHANCES
FOR SNOW POSSIBLE BY THEN AS IT LOOKS EVEN COLDER. TUESDAY AND
WEDNESDAY LOOK DRY AS COLD HIGH PRESSURE BUILDS BACK OVER THE
REGION. WEDNESDAY NIGHT INTO THURSDAY A WEAK UPPER WAVE LOOKS TO
MOVE ACROSS THE REGION WITH SMALL CHANCES FOR SNOW POSSIBLE.
&&
.AVIATION /DISCUSSION FOR 270600Z TAF ISSUANCE/...
ISSUED AT 320 AM EST THU FEB 27 2014
0820Z UPDATE...NO CHANGES NEEDED AT THIS TIME. PREVIOUS DISCUSSION
FOLLOWS.
VFR CONDITIONS EXPECTED THROUGHOUT THE FORECAST PERIOD.
INITIAL IMPACTS WILL COME AS A SHARP COLD FRONT TRACKS THROUGH THE
FORECAST AREA LATE TONIGHT. RAP MODEL SOUNDINGS CONTINUE TO SUPPORT
A BRIEF PERIOD OF LOW LEVEL WIND SHEAR PRIOR TO THE FRONTAL PASSAGE
AS A LOW LEVEL JET ROTATES THROUGH THE REGION. THE FRONT WILL CROSS
THE TERMINALS BETWEEN 08Z AND 11Z FROM NORTHWEST TO SOUTHEAST...WITH
NORTHWEST WIND GUSTS COMMENCING IMMEDIATELY BEHIND THE FRONT AS COLD
ADVECTION ESTABLISHES. TIMING OF THE STRONGEST WIND GUSTS...POSSIBLY
AS HIGH AS 35KT...WILL BE IN THE COUPLE OF HOURS DIRECTLY BEHIND THE
FRONTAL PASSAGE ROUGHLY BETWEEN 09-13Z. MOISTURE IS LIMITED WITH THE
FRONT...BUT MODEL SOUNDINGS AND RH PROGS DO FAVOR SOME VFR STRATOCU
ACCOMPANYING THE BOUNDARY. POTENTIAL EVEN EXIST FOR A FEW FLURRIES.
STRONG HIGH PRESSURE WILL BRING A RETURN TO MOSTLY CLEAR SKIES
SHORTLY AFTER DAYBREAK. WINDS WILL CONTINUE TO GUST AT 25 TO 30KT
THROUGH MIDDAY...SLOWLY DIMINISHING DURING THE AFTERNOON AS THE
SURFACE PRESSURE GRADIENT RELAXES. OTHER THAN SOME PASSING
CIRRUS...CLEAR SKIES WILL CONTINUE INTO THURSDAY NIGHT AS THE HIGH
SETTLES OVER THE REGION.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....SMF
AVIATION...RYAN/SMF
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
321 AM EST THU FEB 27 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 227 PM EST WED FEB 26 2014
AN INACTIVE COLD FRONT IS EXPECTED TO MOVER THROUGH THE AREA LATE
TONIGHT. IN THE WAKE OF THIS FRONT...HIGH PRESSURE WILL BUILD INTO
THE AREA INTO FRIDAY. AN UPPER DISTURBANCE IS EXPECTED TO MOVE
THROUGH FRIDAY NIGHT INTO SATURDAY. A STRONGER SYSTEM WILL AFFECT
THE AREA LATE IN THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 956 PM EST WED FEB 26 2014
UPSTREAM OBSERVATIONS SUGGEST WE CAN EXPECT A PERIOD OF STRONGER
WIND GUSTS AT LEAST IN THE 20-30KT RANGE LATER TONIGHT AS THE
FRONT MOVES THROUGH THE AREA IF NOT SLIGHTLY STRONGER. HAVE ADDED
THIS AS WELL AS A ZONE OF INCREASED CLOUD COVER AS THE FRONT
PASSES THROUGH THE AREA.
SOME SNOW SHOWERS OBSERVED UPSTREAM BUT MAJORITY OF DATA SUGGESTS
THESE WILL LARGELY STAY TO THE NORTH OF THE FORECAST AREA. PERHAPS
SOME FLURRIES COULD OCCUR BUT EXPECT LITTLE MORE THAN THAT.
PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 227 PM EST WED FEB 26 2014
COLD FRONT CURRENTLY DROPPING SOUTHEAST THROUGH THE NORTHERN PLAINS
IS EXPECTED TO MOVE INTO THE LOCAL AREA DURING THE EARLY MORNING
HOURS OF THURSDAY. AIR MASS IS QUITE DRY...SO FRONT SHOULD BE
INACTIVE FOR THE MOST PART...ALTHOUGH THERE COULD BE A NARROW AREA
OF LOWER CLOUD IN THE VICINITY OF THE FRONT.
WARM ADVECTION AHEAD OF THE FRONT LOOKS PRETTY STRONG...SO NOT
EXPECTING MUCH OF A TEMPERATURE FALL UNTIL THE FRONT PASSES DURING
THE PRE DAWN HOURS OF THURSDAY. THE GFS MOS LOWS TONIGHT LOOK
REASONABLE OVER THE NORTHWEST ZONES...BUT WILL RAISE THE LOWS SOME
ELSEWHERE DUE TO THE LATE ARRIVAL OF THE FRONT.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
ISSUED AT 227 PM EST WED FEB 26 2014
MODEL DATA INDICATE THE UPPER FLOW IS EXPECTED TO FLATTEN OUT DURING
THIS PERIOD...WITH HEIGHTS RISING QUITE A BIT BY SATURDAY AS RIDGING
DEVELOP OVER THE GULF COAST STATES IN RESPONSE TO TROUGHING
DEVELOPING OVER THE WESTERN PARTS OF THE COUNTRY.
MAIN ITEM OF INTEREST DURING THIS PERIOD IS AN UPPER DISTURBANCE
THAT IS EXPECTED TO MOVE ACROSS THE LOCAL AREA AROUND FRIDAY NIGHT.
OPERATIONAL MODELS SUGGEST THE MAIN PRECIPITATION THREAT WILL HOLD
OFF UNTIL FRIDAY NIGHT...ALTHOUGH THERE ARE QUITE A FEW ENSEMBLES
THAT SUGGEST THIS MAY BE TOO SLOW. WILL BRING IN SOME CHANCE POPS TO
THE WEST CENTRAL AND SOUTHWEST ZONES BY FRIDAY AFTERNOON TO COVER
THE POTENTIAL FOR THE FASTER SOLUTIONS.
LIKELY POPS STILL LOOK OK FOR FRIDAY NIGHT...GIVEN THE 40-45 KT LOW
LEVEL JET OVERHEAD. QPF SHOULD BE FAIRLY LIGHT AS THERE DOESN/T SEEM
TO BE A LOT OF MOISTURE ADVECTION.
MOST OF THE PRECIPITATION THREAT LOOKS TO BE OVER BY SUNRISE
SATURDAY AT THIS TIME...BUT WITH A WAVY FRONTAL SYSTEM
NEARBY...HESITANT TO KEEP SATURDAY DRY. WILL GO WITH SMALL CHANCE
POPS ON SATURDAY.
GIVEN THE STRONG WARM ADVECTION ALOFT WITH THE LOW LEVEL
JET...LEANING MORE TOWARDS A MIXED PRECIPITATION EVENT FRIDAY NIGHT
INTO SATURDAY RATHER THAN JUST SNOW.
PROGGED LOW LEVEL THICKNESSES SUGGEST THE GFS MOS TEMPERATURES
GUIDANCE IS PROBABLY TOO COLD BY FRIDAY AND FRIDAY NIGHT. WILL NUDGE
UP THE GUIDANCE ABOUT A CATEGORY IN THOSE PERIODS. OTHER PERIODS
LOOK OK.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
ISSUED AT 212 AM EST THU FEB 27 2014
MODELS ARE ACTUALLY FAIRLY CLOSE ON THE SYNOPTIC SCALE AND ALLBLEND
INITIALIZATIONS REFLECT WELL THE TRENDS OF THE LARGE SYSTEM
PROJECTED TO MOVE THROUGH THE REGION SUNDAY AND SUNDAY NIGHT.
THE FOCUS OF THIS PERIOD COMES DOWN TO PRECIPITATION TYPE SUNDAY
AND SUNDAY NIGHT AND IT COMES DOWN TO TEMPERATURES/THICKNESSES
WHICH AS OF LATE HAVE BEEN TRENDING COLDER. AS OF THIS MODEL RUN
THIS MEANS BETTER CHANCES FOR SNOW AS OPPOSED TO FREEZING RAIN OR
SLEET. BEST CHANCE FOR SNOW LIES ACROSS THE NORTHERN HALF OF THE
COUNTY WARNING AREA...BUT A WARM INTRUSION TO OUR SOUTH COULD STILL
BRING CHANCES FOR SLEET AND FREEZING RAIN (SOUTH OF I-70) INTO THE
FORECAST.
DEVELOPED FORECAST TOWARD THIS COLDER TREND HOWEVER WITHOUT COMPLETELY
FLIP-FLOPPING BACK AND FORTH BETWEEN FREEZING RAIN AND SNOW. THE
NORTHERN COUNTIES LOOK LIKE AN ALL SNOW EVENT...WHILE AROUND I-70
APPEARS SNOW WILL BE THE MAIN PRECIP-TYPE WITH CHANCES FOR SLEET
OR FREEZING RAIN POSSIBLE AT TIMES. AND THEN FOR THE SOUTHERN TIER
OF COUNTIES SLEET OR FREEZING RAIN WITH POSSIBLY SOME CHANCES FOR
SNOW LOOK TO BE THE PRECIP-TYPE.
THIS EVENT SHOULD BE WINDING DOWN ON MONDAY...WITH ONLY LOW CHANCES
FOR SNOW POSSIBLE BY THEN AS IT LOOKS EVEN COLDER. TUESDAY AND
WEDNESDAY LOOK DRY AS COLD HIGH PRESSURE BUILDS BACK OVER THE
REGION. WEDNESDAY NIGHT INTO THURSDAY A WEAK UPPER WAVE LOOKS TO
MOVE ACROSS THE REGION WITH SMALL CHANCES FOR SNOW POSSIBLE.
&&
.AVIATION /DISCUSSION FOR 270600Z TAF ISSUANCE/...
ISSUED AT 320 AM EST THU FEB 27 2014
0820Z UPDATE...NO CHANGES NEEDED AT THIS TIME. PREVIOUS DISCUSSION
FOLLOWS.
VFR CONDITIONS EXPECTED THROUGHOUT THE FORECAST PERIOD.
INITIAL IMPACTS WILL COME AS A SHARP COLD FRONT TRACKS THROUGH THE
FORECAST AREA LATE TONIGHT. RAP MODEL SOUNDINGS CONTINUE TO SUPPORT
A BRIEF PERIOD OF LOW LEVEL WIND SHEAR PRIOR TO THE FRONTAL PASSAGE
AS A LOW LEVEL JET ROTATES THROUGH THE REGION. THE FRONT WILL CROSS
THE TERMINALS BETWEEN 08Z AND 11Z FROM NORTHWEST TO SOUTHEAST...WITH
NORTHWEST WIND GUSTS COMMENCING IMMEDIATELY BEHIND THE FRONT AS COLD
ADVECTION ESTABLISHES. TIMING OF THE STRONGEST WIND GUSTS...POSSIBLY
AS HIGH AS 35KT...WILL BE IN THE COUPLE OF HOURS DIRECTLY BEHIND THE
FRONTAL PASSAGE ROUGHLY BETWEEN 09-13Z. MOISTURE IS LIMITED WITH THE
FRONT...BUT MODEL SOUNDINGS AND RH PROGS DO FAVOR SOME VFR STRATOCU
ACCOMPANYING THE BOUNDARY. POTENTIAL EVEN EXIST FOR A FEW FLURRIES.
STRONG HIGH PRESSURE WILL BRING A RETURN TO MOSTLY CLEAR SKIES
SHORTLY AFTER DAYBREAK. WINDS WILL CONTINUE TO GUST AT 25 TO 30KT
THROUGH MIDDAY...SLOWLY DIMINISHING DURING THE AFTERNOON AS THE
SURFACE PRESSURE GRADIENT RELAXES. OTHER THAN SOME PASSING
CIRRUS...CLEAR SKIES WILL CONTINUE INTO THURSDAY NIGHT AS THE HIGH
SETTLES OVER THE REGION.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS/NIELD
SHORT TERM...JAS
LONG TERM....SMF
AVIATION...SMF
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
218 AM EST THU FEB 27 2014
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 227 PM EST WED FEB 26 2014
AN INACTIVE COLD FRONT IS EXPECTED TO MOVER THROUGH THE AREA LATE
TONIGHT. IN THE WAKE OF THIS FRONT...HIGH PRESSURE WILL BUILD INTO
THE AREA INTO FRIDAY. AN UPPER DISTURBANCE IS EXPECTED TO MOVE
THROUGH FRIDAY NIGHT INTO SATURDAY. A STRONGER SYSTEM WILL AFFECT
THE AREA LATE IN THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 956 PM EST WED FEB 26 2014
UPSTREAM OBSERVATIONS SUGGEST WE CAN EXPECT A PERIOD OF STRONGER
WIND GUSTS AT LEAST IN THE 20-30KT RANGE LATER TONIGHT AS THE
FRONT MOVES THROUGH THE AREA IF NOT SLIGHTLY STRONGER. HAVE ADDED
THIS AS WELL AS A ZONE OF INCREASED CLOUD COVER AS THE FRONT
PASSES THROUGH THE AREA.
SOME SNOW SHOWERS OBSERVED UPSTREAM BUT MAJORITY OF DATA SUGGESTS
THESE WILL LARGELY STAY TO THE NORTH OF THE FORECAST AREA. PERHAPS
SOME FLURRIES COULD OCCUR BUT EXPECT LITTLE MORE THAN THAT.
PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 227 PM EST WED FEB 26 2014
COLD FRONT CURRENTLY DROPPING SOUTHEAST THROUGH THE NORTHERN PLAINS
IS EXPECTED TO MOVE INTO THE LOCAL AREA DURING THE EARLY MORNING
HOURS OF THURSDAY. AIR MASS IS QUITE DRY...SO FRONT SHOULD BE
INACTIVE FOR THE MOST PART...ALTHOUGH THERE COULD BE A NARROW AREA
OF LOWER CLOUD IN THE VICINITY OF THE FRONT.
WARM ADVECTION AHEAD OF THE FRONT LOOKS PRETTY STRONG...SO NOT
EXPECTING MUCH OF A TEMPERATURE FALL UNTIL THE FRONT PASSES DURING
THE PRE DAWN HOURS OF THURSDAY. THE GFS MOS LOWS TONIGHT LOOK
REASONABLE OVER THE NORTHWEST ZONES...BUT WILL RAISE THE LOWS SOME
ELSEWHERE DUE TO THE LATE ARRIVAL OF THE FRONT.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
ISSUED AT 227 PM EST WED FEB 26 2014
MODEL DATA INDICATE THE UPPER FLOW IS EXPECTED TO FLATTEN OUT DURING
THIS PERIOD...WITH HEIGHTS RISING QUITE A BIT BY SATURDAY AS RIDGING
DEVELOP OVER THE GULF COAST STATES IN RESPONSE TO TROUGHING
DEVELOPING OVER THE WESTERN PARTS OF THE COUNTRY.
MAIN ITEM OF INTEREST DURING THIS PERIOD IS AN UPPER DISTURBANCE
THAT IS EXPECTED TO MOVE ACROSS THE LOCAL AREA AROUND FRIDAY NIGHT.
OPERATIONAL MODELS SUGGEST THE MAIN PRECIPITATION THREAT WILL HOLD
OFF UNTIL FRIDAY NIGHT...ALTHOUGH THERE ARE QUITE A FEW ENSEMBLES
THAT SUGGEST THIS MAY BE TOO SLOW. WILL BRING IN SOME CHANCE POPS TO
THE WEST CENTRAL AND SOUTHWEST ZONES BY FRIDAY AFTERNOON TO COVER
THE POTENTIAL FOR THE FASTER SOLUTIONS.
LIKELY POPS STILL LOOK OK FOR FRIDAY NIGHT...GIVEN THE 40-45 KT LOW
LEVEL JET OVERHEAD. QPF SHOULD BE FAIRLY LIGHT AS THERE DOESN/T SEEM
TO BE A LOT OF MOISTURE ADVECTION.
MOST OF THE PRECIPITATION THREAT LOOKS TO BE OVER BY SUNRISE
SATURDAY AT THIS TIME...BUT WITH A WAVY FRONTAL SYSTEM
NEARBY...HESITANT TO KEEP SATURDAY DRY. WILL GO WITH SMALL CHANCE
POPS ON SATURDAY.
GIVEN THE STRONG WARM ADVECTION ALOFT WITH THE LOW LEVEL
JET...LEANING MORE TOWARDS A MIXED PRECIPITATION EVENT FRIDAY NIGHT
INTO SATURDAY RATHER THAN JUST SNOW.
PROGGED LOW LEVEL THICKNESSES SUGGEST THE GFS MOS TEMPERATURES
GUIDANCE IS PROBABLY TOO COLD BY FRIDAY AND FRIDAY NIGHT. WILL NUDGE
UP THE GUIDANCE ABOUT A CATEGORY IN THOSE PERIODS. OTHER PERIODS
LOOK OK.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
ISSUED AT 212 AM EST THU FEB 27 2014
MODELS ARE ACTUALLY FAIRLY CLOSE ON THE SYNOPTIC SCALE AND ALLBLEND
INITIALIZATIONS REFLECT WELL THE TRENDS OF THE LARGE SYSTEM
PROJECTED TO MOVE THROUGH THE REGION SUNDAY AND SUNDAY NIGHT.
THE FOCUS OF THIS PERIOD COMES DOWN TO PRECIPITATION TYPE SUNDAY
AND SUNDAY NIGHT AND IT COMES DOWN TO TEMPERATURES/THICKNESSES
WHICH AS OF LATE HAVE BEEN TRENDING COLDER. AS OF THIS MODEL RUN
THIS MEANS BETTER CHANCES FOR SNOW AS OPPOSED TO FREEZING RAIN OR
SLEET. BEST CHANCE FOR SNOW LIES ACROSS THE NORTHERN HALF OF THE
COUNTY WARNING AREA...BUT A WARM INTRUSION TO OUR SOUTH COULD STILL
BRING CHANCES FOR SLEET AND FREEZING RAIN (SOUTH OF I-70) INTO THE
FORECAST.
DEVELOPED FORECAST TOWARD THIS COLDER TREND HOWEVER WITHOUT COMPLETELY
FLIP-FLOPPING BACK AND FORTH BETWEEN FREEZING RAIN AND SNOW. THE
NORTHERN COUNTIES LOOK LIKE AN ALL SNOW EVENT...WHILE AROUND I-70
APPEARS SNOW WILL BE THE MAIN PRECIP-TYPE WITH CHANCES FOR SLEET
OR FREEZING RAIN POSSIBLE AT TIMES. AND THEN FOR THE SOUTHERN TIER
OF COUNTIES SLEET OR FREEZING RAIN WITH POSSIBLY SOME CHANCES FOR
SNOW LOOK TO BE THE PRECIP-TYPE.
THIS EVENT SHOULD BE WINDING DOWN ON MONDAY...WITH ONLY LOW CHANCES
FOR SNOW POSSIBLE BY THEN AS IT LOOKS EVEN COLDER. TUESDAY AND
WEDNESDAY LOOK DRY AS COLD HIGH PRESSURE BUILDS BACK OVER THE
REGION. WEDNESDAY NIGHT INTO THURSDAY A WEAK UPPER WAVE LOOKS TO
MOVE ACROSS THE REGION WITH SMALL CHANCES FOR SNOW POSSIBLE.
&&
.AVIATION /DISCUSSION FOR 270600Z TAF ISSUANCE/...
ISSUED AT 1128 PM EST WED FEB 26 2014
VFR CONDITIONS EXPECTED THROUGHOUT THE FORECAST PERIOD.
INITIAL IMPACTS WILL COME AS A SHARP COLD FRONT TRACKS THROUGH THE
FORECAST AREA LATE TONIGHT. RAP MODEL SOUNDINGS CONTINUE TO SUPPORT
A BRIEF PERIOD OF LOW LEVEL WIND SHEAR PRIOR TO THE FRONTAL PASSAGE
AS A LOW LEVEL JET ROTATES THROUGH THE REGION. THE FRONT WILL CROSS
THE TERMINALS BETWEEN 08Z AND 11Z FROM NORTHWEST TO SOUTHEAST...WITH
NORTHWEST WIND GUSTS COMMENCING IMMEDIATELY BEHIND THE FRONT AS COLD
ADVECTION ESTABLISHES. TIMING OF THE STRONGEST WIND GUSTS...POSSIBLY
AS HIGH AS 35KT...WILL BE IN THE COUPLE OF HOURS DIRECTLY BEHIND THE
FRONTAL PASSAGE ROUGHLY BETWEEN 09-13Z. MOISTURE IS LIMITED WITH THE
FRONT...BUT MODEL SOUNDINGS AND RH PROGS DO FAVOR SOME VFR STRATOCU
ACCOMPANYING THE BOUNDARY. POTENTIAL EVEN EXIST FOR A FEW FLURRIES.
STRONG HIGH PRESSURE WILL BRING A RETURN TO MOSTLY CLEAR SKIES
SHORTLY AFTER DAYBREAK. WINDS WILL CONTINUE TO GUST AT 25 TO 30KT
THROUGH MIDDAY...SLOWLY DIMINISHING DURING THE AFTERNOON AS THE
SURFACE PRESSURE GRADIENT RELAXES. OTHER THAN SOME PASSING
CIRRUS...CLEAR SKIES WILL CONTINUE INTO THURSDAY NIGHT AS THE HIGH
SETTLES OVER THE REGION.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS/NIELD
SHORT TERM...JAS
LONG TERM....SMF
AVIATION...RYAN
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
1128 PM EST WED FEB 26 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 227 PM EST WED FEB 26 2014
AN INACTIVE COLD FRONT IS EXPECTED TO MOVER THROUGH THE AREA LATE
TONIGHT. IN THE WAKE OF THIS FRONT...HIGH PRESSURE WILL BUILD INTO
THE AREA INTO FRIDAY. AN UPPER DISTURBANCE IS EXPECTED TO MOVE
THROUGH FRIDAY NIGHT INTO SATURDAY. A STRONGER SYSTEM WILL AFFECT
THE AREA LATE IN THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 956 PM EST WED FEB 26 2014
UPSTREAM OBSERVATIONS SUGGEST WE CAN EXPECT A PERIOD OF STRONGER
WIND GUSTS AT LEAST IN THE 20-30KT RANGE LATER TONIGHT AS THE
FRONT MOVES THROUGH THE AREA IF NOT SLIGHTLY STRONGER. HAVE ADDED
THIS AS WELL AS A ZONE OF INCREASED CLOUD COVER AS THE FRONT
PASSES THROUGH THE AREA.
SOME SNOW SHOWERS OBSERVED UPSTREAM BUT MAJORITY OF DATA SUGGESTS
THESE WILL LARGELY STAY TO THE NORTH OF THE FORECAST AREA. PERHAPS
SOME FLURRIES COULD OCCUR BUT EXPECT LITTLE MORE THAN THAT.
PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 227 PM EST WED FEB 26 2014
COLD FRONT CURRENTLY DROPPING SOUTHEAST THROUGH THE NORTHERN PLAINS
IS EXPECTED TO MOVE INTO THE LOCAL AREA DURING THE EARLY MORNING
HOURS OF THURSDAY. AIR MASS IS QUITE DRY...SO FRONT SHOULD BE
INACTIVE FOR THE MOST PART...ALTHOUGH THERE COULD BE A NARROW AREA
OF LOWER CLOUD IN THE VICINITY OF THE FRONT.
WARM ADVECTION AHEAD OF THE FRONT LOOKS PRETTY STRONG...SO NOT
EXPECTING MUCH OF A TEMPERATURE FALL UNTIL THE FRONT PASSES DURING
THE PRE DAWN HOURS OF THURSDAY. THE GFS MOS LOWS TONIGHT LOOK
REASONABLE OVER THE NORTHWEST ZONES...BUT WILL RAISE THE LOWS SOME
ELSEWHERE DUE TO THE LATE ARRIVAL OF THE FRONT.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
ISSUED AT 227 PM EST WED FEB 26 2014
MODEL DATA INDICATE THE UPPER FLOW IS EXPECTED TO FLATTEN OUT DURING
THIS PERIOD...WITH HEIGHTS RISING QUITE A BIT BY SATURDAY AS RIDGING
DEVELOP OVER THE GULF COAST STATES IN RESPONSE TO TROUGHING
DEVELOPING OVER THE WESTERN PARTS OF THE COUNTRY.
MAIN ITEM OF INTEREST DURING THIS PERIOD IS AN UPPER DISTURBANCE
THAT IS EXPECTED TO MOVE ACROSS THE LOCAL AREA AROUND FRIDAY NIGHT.
OPERATIONAL MODELS SUGGEST THE MAIN PRECIPITATION THREAT WILL HOLD
OFF UNTIL FRIDAY NIGHT...ALTHOUGH THERE ARE QUITE A FEW ENSEMBLES
THAT SUGGEST THIS MAY BE TOO SLOW. WILL BRING IN SOME CHANCE POPS TO
THE WEST CENTRAL AND SOUTHWEST ZONES BY FRIDAY AFTERNOON TO COVER
THE POTENTIAL FOR THE FASTER SOLUTIONS.
LIKELY POPS STILL LOOK OK FOR FRIDAY NIGHT...GIVEN THE 40-45 KT LOW
LEVEL JET OVERHEAD. QPF SHOULD BE FAIRLY LIGHT AS THERE DOESN/T SEEM
TO BE A LOT OF MOISTURE ADVECTION.
MOST OF THE PRECIPITATION THREAT LOOKS TO BE OVER BY SUNRISE
SATURDAY AT THIS TIME...BUT WITH A WAVY FRONTAL SYSTEM
NEARBY...HESITANT TO KEEP SATURDAY DRY. WILL GO WITH SMALL CHANCE
POPS ON SATURDAY.
GIVEN THE STRONG WARM ADVECTION ALOFT WITH THE LOW LEVEL
JET...LEANING MORE TOWARDS A MIXED PRECIPITATION EVENT FRIDAY NIGHT
INTO SATURDAY RATHER THAN JUST SNOW.
PROGGED LOW LEVEL THICKNESSES SUGGEST THE GFS MOS TEMPERATURES
GUIDANCE IS PROBABLY TOO COLD BY FRIDAY AND FRIDAY NIGHT. WILL NUDGE
UP THE GUIDANCE ABOUT A CATEGORY IN THOSE PERIODS. OTHER PERIODS
LOOK OK.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ISSUED AT 152 PM EST WED FEB 26 2014
ON THE SYNOPTIC SCALE THE MODELS ARE FAIRLY CLOSE. REGIONAL
INITIALIZATION NOT BAD FOR TEMPS AND POPS.
FORECAST PROBLEM IS PRECIPITATION TYPE THIS WEEKEND. UNCERTAINTY
VERY GREAT. MODEL ERRORS THAT ARE SMALL OBJECTIVELY WOULD HAVE HUGE
IMPACT.
MODELS HAVE SLOWLY BEEN GETTING COLDER FROM ONE RUN TO THE NEXT.
CONSIDERING THIS AND LATEST TEMPERATURE CROSS
SECTIONS...NORTHERN COUNTIES SHOULD SEE ONLY SNOW.
SAME METHODOLOGY MAKES SNOW SINGLE MOST LIKELY SINGLE ELEMENT
CENTRAL COUNTIES. HOWEVER...CERTAINLY A CHANCE OF FREEZING RAIN
THERE.
IN THE SOUTH WITH ITS STRONGER WARM INTRUSION WILL SAY FREEZING RAIN
OR SNOW. VERY POSSIBLE SAME SPOT COULD GET BOTH IN SAME PERIOD
DEPENDING ON EXACT DEVELOPMENT OF THE INTRUSION.
WONT HAVE SLEET ANYWHERE. IT COULD CERTAINLY HAPPEN. BUT FOR A HIGH
LEAD TIME INCLUDING SLEET WITH FREEZING RAIN AND SNOW INCREASES
COMPLICATION WITHOUT ADDING MUCH VALUE.
&&
.AVIATION /DISCUSSION FOR 270600Z TAF ISSUANCE/...
ISSUED AT 1128 PM EST WED FEB 26 2014
VFR CONDITIONS EXPECTED THROUGHOUT THE FORECAST PERIOD.
INITIAL IMPACTS WILL COME AS A SHARP COLD FRONT TRACKS THROUGH THE
FORECAST AREA LATE TONIGHT. RAP MODEL SOUNDINGS CONTINUE TO SUPPORT
A BRIEF PERIOD OF LOW LEVEL WIND SHEAR PRIOR TO THE FRONTAL PASSAGE
AS A LOW LEVEL JET ROTATES THROUGH THE REGION. THE FRONT WILL CROSS
THE TERMINALS BETWEEN 08Z AND 11Z FROM NORTHWEST TO SOUTHEAST...WITH
NORTHWEST WIND GUSTS COMMENCING IMMEDIATELY BEHIND THE FRONT AS COLD
ADVECTION ESTABLISHES. TIMING OF THE STRONGEST WIND GUSTS...POSSIBLY
AS HIGH AS 35KT...WILL BE IN THE COUPLE OF HOURS DIRECTLY BEHIND THE
FRONTAL PASSAGE ROUGHLY BETWEEN 09-13Z. MOISTURE IS LIMITED WITH THE
FRONT...BUT MODEL SOUNDINGS AND RH PROGS DO FAVOR SOME VFR STRATOCU
ACCOMPANYING THE BOUNDARY. POTENTIAL EVEN EXIST FOR A FEW FLURRIES.
STRONG HIGH PRESSURE WILL BRING A RETURN TO MOSTLY CLEAR SKIES
SHORTLY AFTER DAYBREAK. WINDS WILL CONTINUE TO GUST AT 25 TO 30KT
THROUGH MIDDAY...SLOWLY DIMINISHING DURING THE AFTERNOON AS THE
SURFACE PRESSURE GRADIENT RELAXES. OTHER THAN SOME PASSING
CIRRUS...CLEAR SKIES WILL CONTINUE INTO THURSDAY NIGHT AS THE HIGH
SETTLES OVER THE REGION.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS/NIELD
SHORT TERM...JAS
LONG TERM...JK
AVIATION...RYAN
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...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
1148 PM CST WED FEB 26 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 220 PM CST WED FEB 26 2014
MAIN FORECAST CONCERN IN THE SHORT TERM IS STRONG WINDS AND THE
RESULTING BLOWING/DRIFTING SNOW EXPECTED ACROSS THE AREA THROUGH
THIS EVENING. LATEST SURFACE ANALYSIS AND OBS SHOW THE COLD FRONT
MOVING THROUGH THE NORTH HALF OF THE FORECAST AREA AT THE CURRENT
TIME... WITH A NICE WIND SHIFT FROM SOUTHWEST TO NORTHWEST BEHIND
THE FRONT. WE/RE SEEING STRONG SOUTHWEST WINDS... SUSTAINED NEAR
20KT WITH GUSTS TO AROUND 30KT AHEAD OF THE FRONT... AND NORTHWEST
WINDS OF AROUND 25KT WITH GUSTS OF 35KT IMMEDIATELY BEHIND THE
FRONT. HOWEVER... FORECAST SOUNDINGS FROM THE RAP AND NAM CONTINUE
TO SUGGEST THE BEST MIXING WITH POST FRONTAL COLD ADVECTION AND
SUBSIDENCE WILL OCCUR DURING THE EARLY EVENING ACROSS MOST OF THE
AREA... WITH 00-05Z LOOKING LIKE PRIME TIME FOR STRONG WINDS AND
POTENTIAL BLIZZARD CONDITIONS. THE HOPWRF MATCHES UP WITH THIS
TIMING QUITE WELL... AND HAS ENSEMBLE MEAN SUSTAINED WINDS OF
AROUND 30 MPH AND GUSTS WELL IN EXCESS OF 40 MPH FOR A PERIOD OF
SEVERAL HOURS. LOCATIONS WHICH WILL SEE THE GREATEST IMPACT STILL
LOOK TO BE THE OPEN AREAS OVER THE WESTERN AND SOUTHERN PART OF
THE AREA... WHERE THE COMBINATION OF DEEP SNOW... STRONG WINDS...
AND FAVORABLE TERRAIN SHOULD LEAD TO WIDESPREAD LOW VISIBILITY AND
SIGNIFICANT DRIFTING SNOW. SOME LIGHT SNOW AND FLURRIES WILL SLIP
THROUGH THE NORTH/NORTHEAST PORTION OF THE AREA THROUGH THIS
EVENING... BUT ANY ACCUMULATION WILL BE VERY MINOR GIVEN THE
EXTREMELY LIMITED MOISTURE AHEAD OF THE SHORTWAVE AND COLD FRONT.
THE PRESSURE GRADIENT LOOKS TO QUICKLY RELAX OVERNIGHT INTO
THURSDAY MORNING... SO WE SHOULD SEE THE BLOWING/DRIFTING SETTLE
DOWN FAIRLY QUICKLY AFTER MIDNIGHT. WILL KEEP THE GOING HEADLINES
IN PLACE... AS WELL AS THE TIMING... WHICH STILL LOOKS TO
ENCAPSULATE THE ENTIRETY OF THE EVENT. HOWEVER... WIND CHILLS WILL
BE PLUMMETING OVERNIGHT AS COLDER AIR ARRIVES. ALTHOUGH WINDS WILL
BE DYING OFF... THEY WILL STILL BE SUFFICIENT TO PRODUCE VERY COLD
WIND CHILLS... WHICH WILL PERSIST INTO THE DAY ON THURSDAY. THE
NORTHERN COUNTIES LOOK LIKE THEY WILL SEE WIDESPREAD WIND CHILLS
OF -35 TO -45... WHILE THE CENTRAL AND SOUTHERN PORTION OF THE
AREA WILL MAINLY BE IN THE -25 TO -35 RANGE. SO... ALTHOUGH THE
HEADLINES FOR BLOWING/DRIFTING SNOW WILL END OVERNIGHT... THEY
WILL BE REPLACED BY WIND CHILL HEADLINES THROUGH THURSDAY MORNING.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 220 PM CST WED FEB 26 2014
LONGER TERM TRENDS CONTINUE TO REMAIN COLD. TEMPERATURES ARE
EXPECTED TO REMAIN FAR BELOW NORMAL THROUGH THE ENTIRE PERIOD.
STANDARDIZED ANOMALIES FROM THE NAM AND GEFS CONTINUE TO SHOW H85
TEMPERATURES AROUND 2 TO 3 STANDARD DEVIATIONS BELOW
NORMAL...WHICH SHOULD CONTINUE TO YIELD 30 TO 40 DEGREES BELOW
NORMAL THROUGH MOST OF THE PERIOD. SOME INDICATIONS AT THE END OF
THE PERIOD...INTO NEXT WEEK...THE UPPER FLOW PATTERN MAY FLATTEN A
BIT OVER THE NORTHERN CONUS...ALLOWING SOME MODIFIED PACIFIC TYPE
AIR TO INTRUDE ACROSS THE NORTHERN PLAINS. THAT IS PRETTY FAR IN
THE FUTURE AND THE 12Z ECMWF IS THE MODEL MOST PROMINENT WITH THIS
OVERALL DEVELOPMENT.
A COUPLE OF SNOW CHANCES COME INTO PLAY...NAMELY FRIDAY AND
SATURDAY/SATURDAY NIGHT. MODELS TREND AN INVERTED TROUGH EAST
ACROSS THE CWA ON FRIDAY. BEST FORCING IS FOUND OVER THE SOUTHERN
CWA. WILL CONTINUE TO MENTION LIKELY POPS FOR THE SOUTHERN
THIRD OF THE AREA THEN. WILL HAVE TO MONITOR FOR DEVELOPMENT ON
THE NORTH END OF THE TROUGH AS WELL...BUT CONTINUE CHANCE POPS
THERE. THIS WOULD GENERATE AN INCH OR TWO OF ACCUMULATION TO THE
SOUTH BY FRIDAY EVENING. SHOULD BE A FLUFFY SNOW AND WINDS DO
INCREASE SOME IN THE WAKE OF THE TROUGH. AT THE PRESENT TIME THEY
DO NOT APPEAR TO BE STRONG ENOUGH TO GENERATE SIGNIFICANT
BLOWING/DRIFTING SNOW CONCERNS.
THE NEXT SNOW THREAT ARRIVES FOR SATURDAY AND SATURDAY NIGHT.
MODELS IN SOME DISAGREEMENT AS TO HOW FAR AND SNOW THREAT WOULD
BE AS LARGE COLD ARCTIC HIGH BUILDS SOUTHEAST OVER THE AREA INTO HE
WEEKEND. AT THE MOMENT THE BEST AGREEMENT REMAINS OVER FAR SOUTHERN
MINNESOTA FOR MEASURABLE SNOW AND WILL MENTION LIKELY POPS IN THAT
AREA.
WIND CHILL CONCERNS WILL CONTINUE INTO THE WEEKEND BUT WINDS
SHOULD GRADUALLY DIMINISH AS THE ARCTIC HIGH SETTLES CLOSE TO THE
CWA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1144 PM CST WED FEB 26 2014
BLOWING SNOW CONCERNS ARE WANING AS WINDS ARE SUBSIDING. VFR
EXPECTED FOR THE REST OF THE PERIOD WITH NORTHWEST WINDS BECOMING
5-10 KT EARLY THURSDAY MORNING...LIGHT/VARIABLE IN THE AFTERNOON...
THEN SOUTH/SOUTHEAST 5 KT THURSDAY EVENING.
KMSP...VFR. DIMINISHING NORTHWEST WINDS WILL BECOME SOUTH/SOUTHEAST
BY LATE THURSDAY AFTERNOON.
/OUTLOOK FOR KMSP/
FRI...CHC MVFR WITH -SN. S WIND 5-10 KT BCMG NW.
SAT...VFR. NNW WIND 10 KT.
SUN...VFR. NW WIND 5 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR MNZ047-
048-054>070-073>078-082>085-091>093.
BLIZZARD WARNING UNTIL 3 AM CST THURSDAY FOR MNZ041-042-048-049-
055>059-065>069-073>077-082>085-091>093.
WIND CHILL WARNING FROM 3 AM TO NOON CST THURSDAY FOR MNZ041>045-
049>053.
WINTER WEATHER ADVISORY UNTIL 3 AM CST THURSDAY FOR MNZ043>045-
047-050>054-060>064-070-078.
WI...WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR
WIZ023>028.
WIND CHILL WARNING FROM 3 AM TO NOON CST THURSDAY FOR WIZ014>016.
WINTER WEATHER ADVISORY UNTIL 3 AM CST THURSDAY FOR WIZ014>016-
023>028.
&&
$$
SHORT TERM...TRH
LONG TERM...DWE
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS TULSA OK
1132 PM CST WED FEB 26 2014
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
CLEAR SKIES AND LIGHT WINDS WILL REMAIN COMMON ACROSS EASTERN
OKLAHOMA AND NORTHWEST ARKANSAS OVERNIGHT TONIGHT AND INTO THE
AFTERNOON HOURS THURSDAY. A FRONTAL BOUNDARY IS EXPECTED TO MOVE
INTO THE REGION DURING THE DAY THURSDAY...WITH VARIABLE WIND
DIRECTIONS INTO THE AFTERNOON HOURS BEFORE A SOUTH SOUTHEASTERLY
WIND DEVELOPS. SCATTERED/BROKEN HIGHS CLOUDS LOOK TO MOVE IN
TOWARD THE END OF THE TAF PERIOD. VFR CONDITIONS ARE SHOULD
CONTINUE THROUGH THE PERIOD AT ALL TAF SITES.
&&
.PREV DISCUSSION... /ISSUED 941 PM CST WED FEB 26 2014/
DISCUSSION...
WITH CLEAR SKIES AND LIGHT WINDS...TEMPERATURES HAVE ALREADY
FALLEN TO NEAR THE FORECAST LOWS IN SOME PLACES. THE LATEST RUNS
OF THE HRRR HAVE SHOWN THIS TREND WELL...AND THEY SUGGEST THAT
TEMPERATURES WILL HOLD NEARLY STEADY FOR MUCH OF THE REST OF THE
NIGHT. A LIGHT WEST TO SOUTHWEST WIND MAY HOLD THE OFFICIAL
TEMPERATURE AT TUL UP SOME MOST OF THE NIGHT...BUT A WIND SHIFT TO
THE NORTH MAY ALLOW FOR A QUICK FALL AT SUNRISE TO THE FORECAST
LOWS. AS A RESULT...THE CURRENT FORECAST LOOKS GOOD AND NO UPDATE
IS NEEDED AT THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 21 50 38 58 / 0 0 20 40
FSM 21 51 33 53 / 0 0 10 40
MLC 19 53 40 62 / 0 0 10 30
BVO 16 49 31 53 / 0 0 20 40
FYV 14 45 29 48 / 0 0 10 50
BYV 19 44 28 45 / 0 0 0 50
MKO 19 50 34 58 / 0 0 10 40
MIO 18 45 30 49 / 0 0 10 50
F10 21 50 37 60 / 0 0 10 30
HHW 20 51 37 65 / 0 0 10 30
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...20
AREA FORECAST DISCUSSION
NWS NORMAN OK
1056 PM CST WED FEB 26 2014
.DISCUSSION...
06 TAF DISCUSSION BELOW.
&&
.AVIATION...
VFR CONDITIONS THROUGHOUT THE TAF PERIOD WITH HIGH AND MID CLOUDS
INCREASING THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 1003 PM CST WED FEB 26 2014/
DISCUSSION...
MINIMUM TEMPERATURES WERE LOWERED SLIGHTLY BASED ON THE RUC TO
BETTER REFLECT LOCAL CONDITIONS ON A DRY, LIGHT-WIND NIGHT.
OTHERWISE THE BIG WARM-UP TOMORROW AND FRIDAY IS UNCHANGED.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 16 54 37 67 / 0 0 10 10
HOBART OK 17 55 36 69 / 0 0 10 10
WICHITA FALLS TX 19 57 39 77 / 0 0 10 10
GAGE OK 20 55 36 64 / 0 0 10 10
PONCA CITY OK 15 46 32 59 / 0 0 20 20
DURANT OK 21 54 36 69 / 0 0 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
09/25/25
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
315 AM EST THU FEB 27 2014
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH FRIDAY...BEFORE AN
UPPER LEVEL DISTURBANCE CROSSES THE FROM THE WEST ON SATURDAY. ANOTHER
WARMING AREA OF HIGH PRESSURE WILL BUILD INTO THE AREA LATE SATURDAY
AND LINGER UNTIL A COLD FRONT APPROACHES ON MONDAY AND BRINGS
WIDESPREAD PRECIPITATION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM EST...SFC FRONT HAS NOW PUSHED SOUTH OF THE CWFA
WITH DEWPOINTS HAVING DROPPED INTO THE TEENS OVER MOST OF OUR OBS
SITES...AND CONTINUING TO DROP SLOWLY. WATER VAPOR IMAGERY SHOWS THE
BROAD TROUGH HAS ALSO DIPPED THRU THE AREA WITH VERY DRY MID-UPPER
LEVELS. FOR THE MOST PART THIS WILL RESULT IN CLEAR SKIES LASTING
THRU THE DAY. COMBINED WITH SOME DEGREE OF DOWNSLOPING...HAVE LEANED
TEMPS IN FAVOR OF BIAS CORRECTED MOS.
HOWEVER...EARLY THIS MORNING A PATCH OF LOW STRATUS HAVE FORMED OVER
THE PIEDMONT NEAR CHARLOTTE POSSIBLY DUE TO LLVL CONVERGENCE DUE TO
THE SFC FRONT AND/OR WEAK LEE TROUGH. THIS IS BEING BEST HANDLED BY
THE HRRR RUNS...WHICH BASICALLY SHOW THE CLOUDS EXPANDING MAINLY
EAST/SOUTH FROM THEIR INITIAL SIZE IN LLVL SWLY FLOW AND WITH DRIER
AIR FILTERING IN FROM THE NORTH. PLACEMENT ON THE HRRR OR RAP IS NOT
PERFECT SO I DREW IN SOME CLOUDS AND TIMED THE MOVEMENT/DISSIPATION
BASED ON THE MODELS. THEY APPEAR TO BE RAPIDLY DISSOLVED BY SOLAR
WARMING AND MIXING AFTER SUNRISE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 200 AM EST THURSDAY...SFC HIGH PRESSURE WILL BUILD ACROSS THE
DELMARVA REGION DURING THE DAY ON FRIDAY...WITH A PRONOUNCED WEDGE
RIDGE EXTENDED SOUTHWEST ALONG THE EAST SLOPES OF THE BLUE RIDGE. AS
THE AIRMASS WILL BE VERY DRY OVER THE REGION...NO CLOUD COVER IS
EXPECTED TO ACCOMPANY THE COLD AIR DAMMING DURING THE DAY ON
FRIDAY...THOUGH THERE WILL BE SOME INCREASING HIGH CLOUDS LATE IN
THE DAY ASSOCIATED WITH AN APPROACHING SHORT WAVE. EVEN WITH SUNNY
SKIES...HIGH TEMPERATURES SHOULD RUN AROUND 10 DEGREES BELOW NORMAL.
A COMPACT...STRONGLY ADVECTIVE SHORT WAVE WILL CROSS THE REGION
FRIDAY NIGHT AND EARLY SATURDAY. THE MID LEVEL ASCENT AND FORCING
WITH THE WAVE IS IMPRESSIVE...THOUGH THE BAND OF FORCING IS RATHER
NARROW. THE DRY LLVLS WILL TAKE A WHILE TO SATURATE. HOWEVER...
STRONG LLVL UPGLIDE WILL DEVELOP OVERNIGHT OVER THE NE PIEDMONT OF
SC AND THE WRN PIEDMONT OF NC. THIS WILL HELP TO SATURATE THE LLVLS
AND WILL LIKELY CONTRIBUTE TO HIGHER PCPN AMOUNTS IN THIS AREA. EVEN
SO...THE SREF MEAN FOR THE PIEDMONT ZONES IS AROUND A TENTH OF AN
INCH OF LIQUID. THE NC MTNS SHOULD ALSO SEE MORE PCPN FOR THE SIMPLE
FACT THAT THEY ARE HIGHER AND THERE WON/T BE AS MUCH DRY LLVL AIR TO
OVERCOME.
THE PCPN SHOULD FALL AS LIGHT SNOW INITIALLY OVER THE NC MTNS AND
NORTH OF I-40...TRANSITIONING TO A PERIOD OF FREEZING RAIN BEFORE
ENDING AROUND SUNRISE. MUCH LIKE THE PREVIOUS SHIFT...MY SNOW
AMOUNTS ARE BELOW ADVISORY CRITERIA OVER THE NC MTNS AND WRN
FOOTHILLS. FREEZING RAIN ACCUMULATIONS REMAIN QUITE
LIGHT...GENERALLY A COUPLE HUNDREDTHS OF AN INCH ACROSS THE CENTRAL
NC MTNS AND THE NC FOOTHILLS AND THE PIEDMONT ZONES NORTH OF
CHARLOTTE. AS THE PCPN AMOUNTS ARE LOOKING A LITTLE HEAVIER OVER THE
ERN ZONES...IT IS POSSIBLE THAT A FREEZING RAIN OR WINTER WX
ADVISORY MAY BE NEEDED FRI NIGHT FOR ICY SPOTS PRIMARILY ON ELEVATED
SFCS. SINCE MY CONFIDENCE OF AN ADVISORY IS IN THE 30 PERCENT
RANGE...I/LL ADD A MENTION OF THIS TO THE HWO.
FINALLY...WITH HIGH PRESSURE OVERHEAD SATURDAY NIGHT AND A MOIST
BOUNDARY LAYER...BUFKIT SOUNDINGS STRONGLY IMPLY THAT FOG WILL
DEVELOP ACROSS MUCH OF THE REGION.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 2 AM EST THURSDAY...THE MEDIUM RANGE FCST PICKS UP AT 12Z ON
SUNDAY WITH UPPER RIDGING OVER THE GULF OF MEXICO AND SE CONUS AND A
SOUTHERN STREAM UPPER TROF OVER THE SW CONUS. AS WE MOVE INTO
MONDAY...HEIGHTS BEGIN TO LOWER AGAIN AS THE UPPER TROF APPROACHES
THE FCST AREA AND EVENTUALLY PHASES BACK WITH THE NORTHERN STREAM BY
LATE MONDAY. THE MODELS INDICATE THAT SOME DEGREE OF UPPER TROFINESS
WILL MAINTAIN ITSELF OVER THE REGION THRU TUES AND INTO WED WITH THE
LATEST 00Z RUN OF THE GFS BEING SLOWER TO LIFT THE TROF ON WED AND
MAINTAINING A MORE AMPLIFIED SYSTEM COMPARED TO THE ECMWF. THE NEXT
FEATURE OF INTEREST APPEARS TO BE ANOTHER SOUTHERN STREAM H5
SHORTWAVE THAT APPROACHES THE CWFA BY THE END OF THE MEDIUM RANGE
NEXT THURS.
AT THE SFC...THE MODELS APPEAR TO BE COMING INTO BETTER AGREEMENT
WITH REGARDS TO THE EVOLUTION OF THE SYNOPTIC PATTERN ESPECIALLY FOR
THE LATTER HALF OF THE MEDIUM RANGE. WEAK BERMUDA HIGH PRESSURE WILL
BE CENTERED TO OUR EAST ON SUN WITH WEAK AND WARMING SLY LOW LVL
FLOW. BY EARLY MON...THE MODELS SPIN UP A LOW OVER THE SOUTHERN MISS
RIVER VALLEY AND MOVE IT OVER THE CWFA BY MON AFTERNOON AND THEN
WELL OFFSHORE BY EARLY TUES. IN THE LOWS WAKE...DRIER CANADIAN HIGH
PRESSURE SPREADS OVER THE REGION ON TUES AND REMAINS IN PLACE THRU
WED. TEMPS WILL START OUT WELL ABOVE NORMAL ON SUNDAY WITH HIGHS IN
THE UPPER 60S FOR THE LOWER ELEVATIONS AND UPPER 50S TO MID 60S FOR
THE HIGHER TERRAIN. BY WED...I ANTICIPATE VALUES WILL COOL BACK DOWN
BELOW CLIMATOLOGY.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
AT KCLT...LOW VFR OR HIGH MVFR STRATUS WILL LIKELY PERSIST THRU
SUNRISE IN LLVL CONVERGENCE ZONE RESULTING FROM LEE TROFING AND
FRONTAL BDY TO THE SOUTH...QUICKLY DISSIPATING ONCE THE SUN FALLS ON
THE CLOUDS. MAIN CONCERN OTHERWISE IS WINDS...ALSO BEING AFFECTED BY
THE LEE TROF TODAY. WINDS STARTING OUT NE EARLY THIS MRNG WOULD THEN
FAVOR NW QUADRANT AFTER DIURNAL MIXING BEGINS...BUT THE TROF IS
LIKELY TO KEEP THEM BACKED TO WNW...POSSIBLY EVEN TO WSW BRIEFLY
AROUND MIDDAY. THEY SHOULD VEER TO NORTHERLY AGAIN TONIGHT.
ELSEWHERE...SKC EXCEPT WHERE LOW STRATUS LINGERS THRU DAYBREAK.
WINDS WILL PREVAIL N TO NW THIS MRNG BUT STAND TO BE AFFECTED BY LEE
TROF OVER THE PIEDMONT TODAY...BRINGING THEM SWLY FOR A TIME.
FREQUENT GUSTS OF 25-30 KT LIKELY AT HIGH MTN ELEVATIONS. SOME
GUSTING LIKELY AT KAVL/KHKY ALSO...THOUGH REMAINING MORE MODERATE
AND LESS FREQUENT. GUSTS WOULD FAVOR NWLY AT ALL SITES. LIGHTER
NORTHERLY WINDS WILL RETURN THIS EVENING.
OUTLOOK...VFR THRU FRI. PRECIPITATION AND SOME RESTRICTIONS ARE
POSSIBLE BEGINNING LATE FRI NIGHT...WITH A LIGHT WINTRY MIX POSSIBLE
MAINLY OVER WRN NC. VFR CONDITIONS SHOULD RETURN SUNDAY...BUT A
FRONTAL SYSTEM WILL LIKELY BRING WIDESPREAD SHOWERS AND SOME
RESTRICTIONS MONDAY.
CONFIDENCE TABLE...
08-14Z 14-20Z 20-02Z 02-08Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.FIRE WEATHER...
FIRE DANGER STATEMENT WILL REMAIN IN EFFECT TODAY WITH RH VALUES
DIPPING WELL INTO THE TEENS AND MODERATE WINDS THROUGHOUT THE AREA.
WINDS ARE PARTICULARLY CONCERNING ONLY IN THE NRN MTNS...WHERE 850MB
FLOW IS A BIT STRONGER. RIDGETOPS MIGHT SEE SUSTAINED SPEEDS 30-35
MPH...WITH GUSTS TO THAT RANGE EVEN IN LOWER ELEVATIONS. SOME
GUSTING LIKELY THROUGHOUT THE MTNS/FOOTHILLS...UP TO AROUND 20 MPH.
COORDINATION WITH FIRE AGENCIES BY DAY SHIFT TODAY MAY RESULT IN RED
FLAG WARNING BEING ISSUED...ESPECIALLY ALONG THE BLUE RIDGE NORTH OF
THE FRENCH BROAD VALLEY.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...WIMBERLEY
SHORT TERM...MCAVOY
LONG TERM...JPT
AVIATION...WIMBERLEY
FIRE WEATHER...WIMBERLEY
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1131 PM CST WED FEB 26 2014
.AVIATION...
/06Z TAFS/
CLEARING CONTINUES OVERNIGHT AS DRIER AIR FROM THE NORTH SPREADS
ACROSS SOUTH CENTRAL TEXAS. WINDS WILL BE LIGHT WITH A NORTHERLY
COMPONENT OVER THE EASTERN TWO-THIRDS OF SOUTH CENTRAL TEXAS. OVER
THE RIO GRANDE...LIGHT SOUTHERLY WINDS WILL PREVAIL THROUGH THURSDAY.
UPPER END MVFR CONDITIONS ARE EXPECTED ACROSS KSAT AND KSSF
OVERNIGHT THROUGH EARLY THURSDAY MORNING DUE VISIBILITY OF 5SM.
OTHERWISE...VFR CONDITIONS EXPECTED FOR MUCH OF THE FORECAST PERIOD.
SOUTHERLY FLOW RETURNS THURSDAY AFTERNOON ACROSS THE REGION AS
SURFACE HIGH PRESSURE SYSTEM OVER EAST TEXAS MOVES PUSHES EASTWARD.
&&
.PREV DISCUSSION... /ISSUED 903 PM CST WED FEB 26 2014/
UPDATE...
WE HAVE UPDATED THE FORECAST TO REMOVE THE MENTION OF
PRECIPITATION THROUGH THE REMINDER OF TONIGHT. RADAR ECHOES
CONTINUE TO DECREASE ACROSS SOUTH CENTRAL TEXAS THIS EVENING AS
DRIER AIR IN THE LOW-LEVELS AND MID-LEVEL SUBSIDENCE SPREAD INTO
THE REGION. WE HAVE ALSO REDUCED CLOUD COVER ACROSS MOST AREAS...
ALTHOUGH LOW CLOUDS MAY PERSIST THROUGH TONIGHT ALONG THE RIO
GRANDE. WE HAVE LOWERED TEMPERATURES A FEW DEGREES ACROSS PORTIONS
OF THE HILL COUNTRY AND ADJACENT I-35 CORRIDOR AS DEW POINTS WILL
DROP INTO THE TEENS OVERNIGHT. WE/LL NEED TO MONITOR LLANO...
BURNET AND WILLIAMSON COUNTIES AS THE RUC13 SUGGESTS LOWS MAY DROP
INTO THE MID 20S. WE HAVE ALSO LOWERED TEMPERATURES A DEGREE OR
TWO ALONG THE HIGHWAY 77 CORRIDOR AS DRIER AIR...LIGHT WINDS AND
DECREASING CLOUD COVER ARE EXPECTED OVER THIS REGION. OTHERWISE...
MINOR CHANGES WERE MADE TO THE WINDS AND DEW POINTS BASED ON THE
LATEST OBSERVATIONAL TRENDS.
PREV DISCUSSION... /ISSUED 527 PM CST WED FEB 26 2014/
AVIATION...
AN AREA OF DRIZZLE/LIGHT RAIN MAINLY ALONG AND SOUTH OF HIGHWAY 90...
WILL CONTINUE TO PUSH TO THE SOUTHEAST THROUGH THIS EVENING. BY
00Z THURSDAY...THIS ACTIVITY SHOULD BE PUSHING OVER THE COASTAL
PLAINS AREA...WHILE NORTHERLY LOW LEVEL WINDS BRING DRIER AIR TO
THE REGION. SURFACE HIGH PRESSURE SYSTEM OVER EAST TEXAS LATE THIS
AFTERNOON/EARLY EVENING WILL PUSH TO THE SOUTHEAST LATE TONIGHT
INTO THURSDAY. THIS WILL RESULT IN THE RETURN OF SOUTHERLY FLOW
ACROSS THE RIO GRANDE PLAINS WITH NORTH/NORTHEASTERLY WINDS ACROSS
THE EASTERN TWO-THIRDS OF SOUTH CENTRAL TEXAS OVERNIGHT AND EARLY
THURSDAY. SOUTHERLY WINDS ARE EXPECTED TO DOMINATE THE AREA
THURSDAY AFTERNOON AS SURFACE HIGH PUSHES TO THE EAST. COULD SEE
UPPER END MVFR CONDITIONS ACROSS KSAT AND KSSF OVERNIGHT DUE TO
CEILINGS OF 5 KFT. OTHERWISE...VFR EXPECTED ACROSS THE ENTIRE FORECAST
AREA BY 12Z THURSDAY THROUGH THE REMAINDER OF THE FORECAST CYCLE.
PREV DISCUSSION... /ISSUED 320 PM CST WED FEB 26 2014/
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...
THE UPPER LEVEL PATTERN THIS MORNING SHOWED A LARGE AMPLITUDE
TROUGH EXTENDING FROM THE GREAT LAKES TO NORTHEAST TEXAS AND A
SECOND TROUGH MOVING ACROSS NORTHERN MEXICO. THIS SECOND FEATURE
IS PULLING MID-LEVEL MOISTURE FROM THE TROPICS ACROSS MEXICO INTO
TEXAS. THE 700 TO 300 MB FLOW ACROSS TEXAS IS SLIGHTLY ANTICYCLONIC.
AT THE SURFACE THE COLD FRONT HAS MOVED SOUTH OF TEXAS AND WINDS
ARE FROM THE NORTH. COLDER...DRIER AIR IS DROPPING INTO OUR CWA.
PRECIPITATION WILL BE ENDING THIS EVENING FROM NORTHWEST TO
SOUTHEAST. WHERE THERE IS PRECIPITATION THIS EVENING..TEMPERATURES
WILL BE ABOVE FREEZING AND IT SHOULD BE ALL RAIN. LOW TEMPERATURES
OVERNIGHT WILL DROP TO FREEZING OR BELOW OVER THE HILL COUNTRY AND
ADJACENT AREAS FROM CONCAN TO LA GRANGE. MOST OF THE SAN ANTONIO
METRO AREA WILL BE ABOVE FREEZING WITH ONLY THE EXTREME NORTHERN
PORTION OF THE AREA DROPPING TO OR BELOW 32. A WARMING TREND WILL
BEGIN THURSDAY WITH THE SURFACE WINDS TURNING TO THE SOUTHEAST BY
THE AFTERNOON.
LONG TERM (FRIDAY THROUGH WEDNESDAY)...
AN UPPER LEVEL RIDGE WILL BUILD OVER THE SOUTHERN PLAINS FOR THE
END OF THE WEEK. THE LOW LEVEL FLOW WILL REMAIN FROM THE SOUTHEAST
MAKING FRIDAY AND SATURDAY QUITE WARM. SATURDAY MORNING THE
SOUTHEASTERLY FLOW MAY PRODUCE PATCHY DRIZZLE ACROSS THE THE
SOUTHEASTERN PART OF THE CWA AS FAR NORTH AS I-35. SUNDAY ANOTHER
COLD FRONT WILL MOVE THROUGH BRINGING A CHANCE FOR SHOWERS AND
THUNDERSTORMS SUNDAY AND MONDAY. IT WILL ALSO BRING ANOTHER ROUND
OF COLD AIR WITH FREEZING TEMPERATURES POSSIBLE AGAIN IN THE HILL
COUNTRY TUESDAY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 32 63 46 78 59 / - 0 - - -
AUSTIN BERGSTROM INTL AIRPORT 28 60 41 76 55 / - 0 - - -
NEW BRAUNFELS MUNI AIRPORT 32 61 42 76 57 / - 0 - - -
BURNET MUNI AIRPORT 27 60 42 77 53 / - 0 - - -
DEL RIO INTL AIRPORT 36 65 45 81 56 / - - 0 - -
GEORGETOWN MUNI AIRPORT 28 60 42 75 55 / - 0 - - -
HONDO MUNI AIRPORT 34 64 42 81 54 / - 0 - - -
SAN MARCOS MUNI AIRPORT 31 60 42 75 57 / - 0 - - -
LA GRANGE - FAYETTE REGIONAL 30 58 44 72 60 / - - 10 - -
SAN ANTONIO INTL AIRPORT 33 65 47 80 60 / - 0 - - -
STINSON MUNI AIRPORT 35 64 45 79 58 / - 0 - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...17
SYNOPTIC/GRIDS...24
AREA FORECAST DISCUSSION
NWS TAUNTON MA
640 AM EST THU FEB 27 2014
.SYNOPSIS...
AN ARCTIC FRONT WILL BRING A CHANCE OF SNOW SHOWERS AND SQUALLS
THURSDAY AFTERNOON FOLLOWED BY BITTER COLD THURSDAY NIGHT INTO
FRIDAY WITH WIND CHILLS DROPPING WELL BELOW ZERO. LIGHT SNOW IS
AGAIN POSSIBLE SATURDAY INTO SUNDAY...FOLLOWED BY A SIGNIFICANT
WINTER STORM CENTERED AROUND MONDAY. UNSEASONABLY COLD AND DRY
CONDITIONS CONTINUE THROUGH THE END OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
7 AM UPDATE...
ECHO SIMILAR SENTIMENTS TO THE PREVIOUS DISCUSSION.
OVER THE PAST FEW DAYS THERE HAVE BEEN INSTANCES IN WHERE THE
NEAR-TERM MESOSCALE GUIDANCE HAS BEEN ROBUST WITH PRECIPITATION
AND RADAR SIMULATION OUTPUT ONLY TO BE OVERDONE DUE TO THE
ABUNDANCE OF DRY AIR ACROSS THE REGION. SUCH GUIDANCE PRESENTLY
HINTS AT STEEP LAPSE-RATES TO H7 UNDERGOING DYNAMIC COOLING AHEAD
OF THE ARCTIC FRONT...SUGGESTING SNOW SHOWERS/SQUALLS INTO THIS
AFTERNOON. SIGNIFICANT CAPE VALUES UP TO AROUND 100 J/KG COUPLED
WITH INVERTED-V PROFILES NEAR THE SURFACE HINT AT THE POTENTIAL OF
VERY GUSTY WINDS.
FEEL A LEVEL OF HESITATION CONCERNING SIGNIFICANT SNOW ACTIVITY.
THE BETTER CHANCES MAY BE E/SE WITH THE SOUTHERLY FETCH OF
MOISTURE OFF THE ATLANTIC /THUS GIVING VALUE TO THE HRRR RADAR
REFLECTIVITY SIMULATIONS/. HAVE HIGH CONFIDENCE THAT LAPSE RATES
WILL STEEPEN ALLOWING FOR THE EFFECTIVE MIX-DOWN OF FASTER
MOMENTUM TO THE SURFACE. EXPECT GUSTY SW WINDS DURING THE DAY.
PREVIOUS DISCUSSION...
MID LEVEL CLOUDS STARTING TO MOVE OVER PORTIONS OF WESTERN
MA...SOUTHERN NH AND NORTHERN CT. TEMPERATURES HAVE SUSPENDED
THEIR FREEFALL AT LOCATIONS BENEATH THESE CLOUDS...AT LEAST FOR
NOW. WILL STILL NEED TO WATCH TEMPERATURES THIS MORNING FOR
FURTHER TWEAKS.
AS FOR THE REST OF TODAY...AM RATHER CONFLICTED OVER THIS
FORECAST. ON ONE HAND...THERE ARE MANY FACTORS WHICH WOULD ARGUE
FOR AT LEAST SCATTERED SNOW SHOWERS...WITH SNOW SQUALLS NOT OUT OF
THE QUESTION. THERE IS PLENTY OF SYNOPTIC LIFT ALONG AND AHEAD OF
AN ARCTIC FRONT WHICH SHOULD CROSS OUR REGION LATER TODAY. THE KEY
MISSING INGREDIENT IS LOW LEVEL MOISTURE.
OBSERVED DEW POINT DEPRESSIONS ARE BETWEEN 10-20 DEGREES
FAHRENHEIT. OF THE 27/00Z GUIDANCE...ONLY THE GFS IS BULLISH
ENOUGH TO MOISTEN THE LOW LEVELS WHERE SIGNIFICANT ACCUMULATING
SNOW BECOMES A REAL POSSIBILITY. GIVEN THE AMOUNT OF LOW LEVEL DRY
AIR...KEPT ONLY SCATTERED SNOW SHOWERS TODAY. STILL EXPECTING
GENERALLY LESS THAN 1 INCH OF SNOW...WHERE IT SNOWS AT ALL. SHOULD
STRONGER SQUALLS DEVELOP...UP TO 2 INCHES OF SNOW WOULD BE
POSSIBLE AT THOSE LOCATIONS.
AN ARCTIC FRONT SHOULD RACE ACROSS SOUTHERN NEW ENGLAND BY LATE
THIS AFTERNOON. THIS WILL MEAN GUSTY SOUTHWEST TO WEST WINDS.
TEMPERATURES SHOULD BE SLIGHTLY LOWER TODAY THAN YESTERDAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
TONIGHT...
A FEW LINGERING FLURRIES OR SNOW SHOWERS POSSIBLE EARLY...THEN
CLEARING SKIES. ARCTIC FRONT CONTINUES TO MOVE OFFSHORE AS STRONG
COLD AIR ADVECTION DEVELOPS. GUSTY WEST WINDS CONTINUE THROUGH
THIS EVENING...THEN DIMINISH. TEMPERATURES WILL NOT QUITE PLUMMET
DUE TO THE STRONGER WINDS. WILL NEED A WIND ADVISORY FOR PORTIONS
OF WESTERN AND CENTRAL MA...MAINLY ACROSS THE HIGHER TERRAIN. WIND
CHILLS WILL BE FAIRLY LOW ACROSS PORTIONS OF SOUTHERN NH AS
WELL...JUST NOT LOW ENOUGH TO MEET THE CRITERIA FOR AN ADVISORY.
VERY IMPRESSIVE FOR THIS LATE IN THE WINTER SEASON.
FRIDAY...
SLIGHT COLD AIR ADVECTION CONTINUES FRIDAY...BUT WILL BE COMPETING
WITH AN INCREASING SUN ANGLE. IT LOOKS LIKE A TOSS-UP... SO STAYED
FAIRLY CLOSE TO THE MOS GUIDANCE. DRY WITH PLENTY OF SUNSHINE.
GUSTY WINDS REDEVELOP FROM MID MORNING INTO MID AFTERNOON.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
*/ HIGHLIGHTS...
- UNSEASONABLY COLD TEMPERATURES PREVAIL THROUGHOUT THE FORECAST
- LIGHT SNOW SHOWERS SATURDAY INTO SUNDAY
- A SIGNIFICANT WINTER STORM LIKELY AROUND MONDAY
- COLD ARCTIC AIR RETURNS FOR THE REMAINDER OF THE WEEK
*/ OVERVIEW AND MODEL PREFERENCE...
UNSEASONABLY COLD CONDITIONS AND AN ACTIVE WEATHER PATTERN THROUGH
THE CONFLUENT FLOW ALONG THE BASE OF THE POLAR LOW ACROSS EASTERN
CANADA PREVAILS OVER THE NORTHEASTERN CONUS THROUGH /PERHAPS/ MID-
MARCH. IT DOES NOT APPEAR CONDITIONS WILL WARM ANYTIME SOON.
27.0Z GUIDANCE EXHIBITS TIGHTER CLUSTERING TOWARDS ENSEMBLE MEANS
FOR THE ANTICIPATED WINTER STORM CENTERED AROUND MONDAY. SENSIBLE
WEATHER DETAILS REMAIN HIGHLY UNCERTAIN ROUGHLY 5-DAYS OUT IN THE
FORECAST...NEVERTHELESS TOOK A CONSENSUS BLEND AND HAVE OUTLINED
CONFIDENCE /IN BROAD TERMS/ THROUGHOUT THE DISCUSSION BELOW.
*/ DAY-TO-DAY DETAILS...
FRIDAY NIGHT INTO SUNDAY...
UNSEASONABLY COLD CONDITIONS CONTINUE. MAIN FORECAST CONCERN IS A
CHANCE OF LIGHT SNOW SHOWERS SATURDAY INTO SUNDAY ALONG A COLD FRONT.
MODERATE CONFIDENCE FORECAST. CLIPPER-LOW AIRMASS WITH CONTINENTAL-
POLAR CHARACTERISTICS. BEST DYNAMICS/LIFT WELL NORTH...PARENT WITH
THE LOW. AS THE FRONT SAGS SOUTH...IT BEGINS TO LATCH INTO SOUTHERN-
STREAM SUB-TROPICAL FLOW. YET LIFT IS LIMITED BY PARALLEL-FLOW ALONG
THE FRONT /LESSER CONVERGENCE/. LOW-LEVEL F-GEN WILL LIKELY BE THE
MAIN FORCING MECHANISM TO YIELD LIGHT SNOW-SHOWER ACTIVITY /PERHAPS
SUPPRESSED ENTIRELY BY THE NEIGHBORING INFLUENCE OF HIGH PRESSURE/.
CHANCE POPS WARRANTED. VERY LIGHT SNOW ACCUMS. DO NOT ANTICIPATE
MUCH IN THE WAY OF IMPACTS.
OTHERWISE...PERHAPS MILD FOR SATURDAY WITH HIGHS AROUND THE LOW- TO
MID-30S AS H85 TEMPS AVERAGE AROUND -5C. MOSTLY CLEAR CONDITIONS
EXPECTED...AND WITH HIGH FEBRUARY SUN-ANGLE IT WILL LIKELY FEEL
SLIGHTLY WARMER. BREEZY SOUTHWEST FLOW AHEAD OF THE FRONT INTO
MIDDAY SUNDAY WHEN ITS PASSAGE IS ANTICIPATED.
SUNDAY NIGHT INTO MONDAY NIGHT...
NORTHERN AND SOUTHERN STREAM IMPULSES CONVERGE /PERHAPS PHASING/ AND
STRETCH THROUGH THE CONFLUENT AND PROGRESSIVE NEAR-ZONAL FLOW ALONG
THE SOUTHERN-PERIPHERY OF THE HUDSON BAY POLAR VORTEX. AN ELONGATED
AREA OF SURFACE LOW PRESSURE IS INVOKED ALONG THE COLD FRONT NOW
STALLED SOUTH OF THE NEW ENGLAND COASTLINE IN REGIONS OF BETTER
BAROCLINICITY RESULTING IN THE LIKELY SETUP OF A SIGNIFICANT WINTER
STORM.
AN OVER-RUNNING EVENT WITH A FRONT-END THUMP CENTERED AROUND MONDAY.
CONSIDERING THE TIGHTER CLUSTERING AND SIMILAR STRENGTH OF 27.0Z
GUIDANCE...INCREASING CONFIDENCE OF STRONG E/NE WINDS OFF THE COLDER
WATERS OF THE GULF OF MAINE COMBINED WITH AGEOSTROPHIC/ISALLOBARIC
UNDERCUTTING DRAINAGE FLOW SOUTHWARD WILL YIELD A VERY TIGHT NORTH-
TO-SOUTH GRADIENT OF SNOW-WINTRY MIX-RAIN. NORTH OF THIS GRADIENT
THE COMBINATION OF ISENTROPIC ASCENT AND H8-6 CONVERGENCE/F-GEN
FORCING OF THE WCB BENEATH STRONG REGIONS OF DIVERGENCE /RRQ OF THE
UPPER-LEVEL JET/ WILL YIELD DEEP-LAYER ASCENT THRU BETTER DENDRITIC
SNOW-GROWTH REGIONS GENERATING ROUGHLY WEST-TO-EAST MESOSCALE SNOW-
BANDING WITH 1-2 INCH PER HOUR SNOWFALL RATES POSSIBLE. WILL HAVE
TO ALSO MONITOR FOR THE POTENTIAL DEVELOPMENT OF A COASTAL FRONT
AS WELL AS THE LONG-FETCH OF THE EASTERLY JET...WHETHER WE WILL
SEE LOCALIZED CONVERGENCE /PERHAPS AGAINST THE HIGHER TERRAIN AS
WELL/.
SOME COASTAL CONCERNS AS TIDES WILL BE NOTABLY HIGH DURING THE TIME
OF STORM PASSAGE. NOON-TIME HIGH TIDE FOR BOSTON ON MONDAY IS AT 11
FEET. THE COMBINATION OF PERHAPS STRONG E/NE FLOW WITH HIGH TIDE
COULD RESULT IN MINOR COASTAL CONCERNS...ALBEIT THE SHORT RESIDENCE
TIME MAY MEAN LITTLE IF ANY IMPACT AT ALL. LOW TIDE MONDAY EVENING
AS THE LOW LIFTS AND DEEPENS ACROSS THE GULF OF MAINE.
STILL CAUTIOUS AS THE ABOVE DISCUSSION IS BROADLY SPEAKING WITH
REGARDS TO TRENDS BASED ON THE TIGHT CLUSTERING OF DETERMINISTIC
SOLUTIONS AS NOTED ABOVE. STILL CONTINUED UNCERTAINTY IN SPECIFIC
SENSIBLE WEATHER DETAILS. THERE IS NOT ENOUGH CONFIDENCE TO STATE
SPECIFICALLY WHERE OR WHEN IMPACTS WILL BE FELT. VARIANCE IN
ENSEMBLE MEMBERS WITH DETERMINISTIC SOLUTIONS LENDS TO SIGNIFICANT
SPATIAL AND TEMPORAL DIFFERENCES. NOTHING IS CERTAIN. SLIGHT WOBBLES
IN BOTH LOW AND FRONTAL POSITIONS IN PROXIMITY TO THE SOUTH-COAST OF
NEW ENGLAND CONTINUE TO EXIST. THERE ARE ALSO PERHAPS ISSUES BETWEEN
THE INTERACTION/PHASING OF NORTHERN- AND SOUTHERN-STREAM IMPULSES.
AS A FINAL NOTE...CIPS ANALOG GUIDANCE BASED ON THE 27.0Z GFS HAS
THE MEAN SNOWFALL BASED ON THE TOP ANALOGS ALONG THE SOUTHERN-TIER
OF NEW ENGLAND STRETCHING BACK INTO PA WITH A GREATER THAN 40
PERCENT CONFIDENCE-LEVEL OF SEEING 6 OR MORE INCHES. THIS ADDS TO
THE OVERALL FORECAST-CONFIDENCE OF A SIGNIFICANT WINTER-STORM
IMPACT.
TUESDAY AND BEYOND...
192- AND 264-HR CIPS ANALOG GUIDANCE ALONG WITH THE 8-DAY CANADIAN
COMPOSITE CONTINUE TO EXHIBIT BELOW-NORMAL CONDITIONS AS A STRONG
NEGATIVE HEIGHT ANOMALY PERSISTS OVER THE HUDSON BAY REGION. BETTER
AGREEMENT IN A STRONG ARCTIC HIGH PRESSURE BUILDING SOUTH INTO NEW
ENGLAND WITH SOME VERY COLD AIR INTO THE END OF THE WEEK.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH FRIDAY/...HIGH CONFIDENCE.
VFR. -SHSN BY THIS AFTERNOON SOME OF WHICH WILL BE MODERATE.
HIGHER CONFIDENCE FOR E/SE SHORELINE TERMINALS. MINOR SNOW ACCUMS.
MAY SEE TEMPO MVFR-IFR IMPACTS. NOT ENOUGH CONFIDENCE THOUGH TO
MENTION IN TAFS AS ACTIVITY WILL BE HIT-OR-MISS. GUSTY SW WINDS UP
TO AROUND 30 KTS ESPECIALLY FOR SOUTH-SHORELINE TERMINALS.
ACTIVITY DIMINISHES OVERNIGHT AS THE ARCTIC FRONT SWEEPS THROUGH
AND WINDS BACK W/NW BECOMING QUIET BY FRIDAY.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. BEST CHANCE FOR SNOW
ACTIVITY IS AROUND 19-23Z.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK...FRIDAY NIGHT THROUGH MONDAY NIGHT...
FRIDAY NIGHT INTO SUNDAY...HIGH CONFIDENCE.
MOSTLY VFR. SOME -SHSN POSSIBLE AHEAD OF A COLD FRONT WHICH WILL
SLIDE THRU THE TERMINALS SUNDAY. BLUSTERY SW WINDS ALONG AND AHEAD
POSSIBLE.
SUNDAY NIGHT INTO MONDAY NIGHT...MODERATE CONFIDENCE.
CONDITIONS DETERIORATING WITH ONSET OF WINTER STORM. IFR-VLIFR
LIKELY. BLUSTERY E/NE POSSIBLE BACKING W/NW WITH STORM DEPARTURE.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
THROUGH FRIDAY...HIGH CONFIDENCE.
GALE WARNINGS POSTED FOR ALL SOUTHERN NEW ENGLAND COASTAL WATERS
EXCEPT BOSTON HARBOR AND NARRAGANSETT BAY. SMALL CRAFT ADVISORIES
POSTED FOR THOSE WATERS. A FREEZING SPRAY ADVISORY CONTINUES.
W/SW WINDS WILL INCREASE THIS AFTERNOON AHEAD OF AN ARCTIC FRONT.
THIS FRONT WILL MOVE EAST OF ALL OF THE WATERS BY LATE THIS
EVENING. GALES ARE LIKELY AS THE COLDER AIRMASS MOVES OVER THE
WATERS. GALE FORCE WINDS GRADUALLY DIMINISH FROM WEST TO EAST
LATE TONIGHT INTO FRIDAY. WILL HAVE TO REPLACE THE GALE WARNINGS
WITH SMALL CRAFT ADVISORIES WHEN THE TIME COMES LATE TONIGHT INTO
FRIDAY.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY NIGHT...
FRIDAY NIGHT INTO SUNDAY...MODERATE CONFIDENCE.
HIGH PRES MOVES OUT AS A COLD FRONT SLIDES SOUTH AND STALLS ACROSS
THE SOUTHERN WATERS SUNDAY. CHANCE OF LIGHT SNOW SHOWERS. PERHAPS
SOME BLUSTERY SW WINDS AHEAD OF THE FRONT...COULD SEE WAVES KICK UP
IN EXCESS OF 5 FEET ON THE OUTER WATERS.
SUNDAY NIGHT INTO MONDAY NIGHT...MODERATE CONFIDENCE.
WINTER STORM. WILL SEE INCREASING E/NE WINDS WITH THE APPROACH OF
THE STORM BACKING W/NW WITH DEPARTURE. SEAS POTENTIALLY BUILDING 10-
12 FEET ON THE OUTER WATERS. IMPACTS DUE TO A MIX OF PRECIPITATION
TYPES.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...WIND CHILL ADVISORY FROM 10 PM THIS EVENING TO 9 AM EST FRIDAY
FOR MAZ002>004-008-009.
NH...NONE.
RI...NONE.
MARINE...FREEZING SPRAY ADVISORY FROM 7 PM THIS EVENING TO 9 AM EST
FRIDAY FOR ANZ231>235-237-250-251-254>256.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 4 AM EST FRIDAY FOR
ANZ231>235-237.
SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 10 AM EST
FRIDAY FOR ANZ230.
SMALL CRAFT ADVISORY FROM NOON TODAY TO 10 AM EST FRIDAY FOR
ANZ236.
GALE WARNING FROM 6 PM THIS EVENING TO 6 AM EST FRIDAY FOR
ANZ250-254.
GALE WARNING FROM 8 PM THIS EVENING TO 4 AM EST FRIDAY FOR
ANZ251.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 6 AM EST FRIDAY FOR
ANZ255-256.
&&
$$
SYNOPSIS...BELK/SIPPRELL
NEAR TERM...BELK/SIPPRELL
SHORT TERM...BELK
LONG TERM...SIPPRELL
AVIATION...BELK/SIPPRELL
MARINE...BELK/SIPPRELL
AREA FORECAST DISCUSSION
NWS MIAMI FL
956 AM EST THU FEB 27 2014
.UPDATE...
NO CHANGES WERE NECESSARY TO CURRENT FORECAST. CLOUDY SKIES WILL
PREVAIL TODAY AS THE FRONTAL BOUNDARY CONTINUES MOVING SOUTH. AT THIS
MOMENT...IT IS LOCATED ACROSS THE LAKE OKEECHOBEE REGION. A FEW
SPOTTY AND WEAK SHOWERS ARE DEVELOPING MAINLY ACROSS THE LOCAL
ATLANTIC AND GULF WATERS. THIS TREND WILL CONTINUE THROUGH THE
DAY. LATEST HRRR RUN CONTINUES TO SHOW THIS ACTIVITY AND AN
INCREASE IN PRECIPITATION TOWARDS THE EVENING AS A MOISTURE SURGE
LOCATED ACROSS THE GULF MOVES THROUGH SOUTH FLORIDA.
&&
.PREV DISCUSSION... /ISSUED 627 AM EST THU FEB 27 2014/
AVIATION...
THE TAF SITES WILL SEE THE WINDS SLOWLY SWING FROM WEST EARLY THIS
MORNING TO NORTHWEST AS THE MORNING PROGRESSES AND THE COLD FRONT
MOVES THROUGH THE AREA. KAPF ALREADY NW AND SHOULD REMAIN THAT WAY
ALL DAY, WITH KMIA AREA SITES BECOMING NW BY MIDDAY. WIND SPEEDS
WILL REMAIN 10-12 KNOTS TODAY. MVFR CEILINGS WILL PREVAIL BOTH
AHEAD AND BEHIND THE FRONT TODAY, WITH THE POTENTIAL FOR CEILINGS
BELOW 2000 FT AFTER 16Z BEHIND THE FRONT AS PLENTY OF DEEP
MOISTURE REMAINS. SHOWER ACTIVITY WILL BE LIMITED THIS MORNING
THROUGH MIDDAY, WITH SCATTERED SHOWERS POSSIBLE AGAIN THIS
AFTERNOON. NOT ENOUGH CONFIDENCE TO PUT IN TAF OTHER THAN A VCSH
MENTION. BAXTER/MOLLEDA
PREV DISCUSSION... /ISSUED 312 AM EST THU FEB 27 2014/
.BRIEF INTERRUPTION IN OUR NICE WEATHER TODAY, BUT SUNSHINE
RETURNS FOR THE WEEKEND AHEAD; CONTINUED SEASONABLY WARM...
DISCUSSION...A WEAKENING COLD FRONT JUST NORTH OF LAKE
OKEECHOBEE WILL SAG SOUTHEASTWARD ACROSS OUR LOCAL AREA LATE THIS
AFTERNOON-EVENING. SURFACE WINDS ARE CURRENTLY SOUTHWESTERLY AHEAD
OF THE FRONT, SO LITTLE CONVERGENCE WILL OCCUR WITH ITS PASSAGE.
SEA BREEZES WON`T HELP EITHER, AS LOW LEVEL WINDS WILL BE TOO
STRONG AND HEATING WILL BE LESS COMPARED TO RECENT. GIVEN THIS
AND LIMITED INSTABILITY DUE TO EXTENSIVE CLOUDINESS, ALONG WITH
CURRENT RADAR TRENDS, HAVE LOWERED POPS TO SCATTERED CATEGORY
TODAY-TONIGHT. HAVE ALSO REMOVED TSTORMS FROM THE FORECAST GIVEN
THE ABOVE AND THIS IS IN LINE WITH SPC.
FRIDAY LOOKS TO BE A DAY OF GRADUAL IMPROVEMENT FROM NW TO SE AS
DRIER AIR SLOWLY SPREADS IN FROM THE NW. THE HIGHEST SHOWER
CHANCES WILL BE SOUTHEAST, BUT THE LATEST CONSENSUS SHOWS IT DRY
FROM THE GULF COAST TO THE LAKE OKEECHOBEE REGION.
TEMPS WILL BE SLIGHTLY COOLER TODAY-FRIDAY, ALONG WITH DECREASING
HUMIDITY. DEWPOINTS ARE STILL AROUND 70F ACROSS SOUTH FL, BUT
HAVE FALLEN OFF TO AROUND 60F AT TAMPA. THIS DRIER AIR WILL SPREAD
INTO SOUTH FLORIDA TODAY-FRIDAY, ALLOWING FOR NOTICEABLY COOLER
NIGHTS. DAYTIME HIGHS WILL BE IN THE 70S AT MOST LOCALES TODAY-
FRIDAY BEFORE WARMING BACK INTO THE 80S THIS WEEKEND AND INTO
EARLY NEXT WEEK. HIGH PRESSURE BUILDING IN AT ALL LEVELS ALONG
WITH SUFFICIENTLY LOW RH`S THROUGH THE COLUMN SUGGESTS THAT
SUNSHINE WILL BE IN FULL FORCE THIS WEEKEND INTO EARLY NEXT WEEK.
BOTH GFS AND ECMWF SHOW A FAIRLY WEAK COLD FRONT MOVING ACROSS
SOUTH FL DURING THE MIDDLE PART OF NEXT WEEK, BUT SOMETHING TO
WATCH FOR LATE NEXT WEEK IS A STRONG SHORTWAVE SHOWN BY BOTH
GFS/ECMWF INTO THE GULF OF MEXICO, WHICH EVENTUALLY SPAWNS
AN INTENSE OCEAN STORM OVER THE ATLANTIC. THIS COULD RESULT IN AN
ACTIVE COLD FRONT MOVING ACROSS THE FLORIDA PENINSULA...SOMETHING
TO WATCH FOR TSTORM POTENTIAL DOWN THE ROAD.
MARINE...SW WINDS HAVE INCREASED OVER THE MARINE AREA WITH WINDS
PREVAILING AT 15-20 KT. WINDS PEAK THIS MORNING THEN GRADUALLY
SUBSIDE. NWPS SHOWS SEAS SIG WAVE HEIGHTS PEAKING AT 4 FT TODAY.
WINDS/SEAS THEN SUBSIDE FRIDAY AND INTO THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 77 57 78 61 / 50 40 20 -
FORT LAUDERDALE 79 62 76 65 / 50 40 40 -
MIAMI 80 62 78 66 / 50 40 40 -
NAPLES 73 54 74 59 / 40 30 10 -
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...17/ERA
AVIATION/RADAR...59/RM
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
905 AM EST THU FEB 27 2014
.UPDATE (REST OF TODAY AND TONIGHT)...
14Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN UPPER LEVEL PATTERN
DOMINATED BY RIDGING OVER THE CONTINENTAL DIVIDE...FOLLOWED
DOWNSTREAM BY A LARGE LONGWAVE TROUGH IN CONTROL OF MUCH OF THE
EASTERN HALF OF THE NATION. A POTENT AND VERY COLD LOBE OF ENERGY
WITHIN THIS TROUGH IS PASSING OVER THE GREAT LAKES THIS MORNING WITH
H5 HEIGHTS OF 485-490DM AND 850MB TEMPS AS LOW AS -30. THAT IS COLD
FOR THIS LATE IN FEBRUARY...EVEN FOR THE GREAT LAKES REGION. WE WILL
SEE JUST A QUICK GLANCING COOL DOWN THE NEXT DAY OR 2 BEFORE A QUICK
REBOUND IN TEMPS DURING THE UPCOMING WEEKEND.
AT THE SURFACE...WEAK COLD FRONT IS NOW ANALYZED OVER SOUTH
FLORIDA...THROUGH ALL OF OUR FORECAST ZONES. WINDS HAVE SHIFTED
NORTH AND NORTHWEST ACROSS THE ENTIRE REGION WITH A COOLER AIRMASS
FILTERING SOUTHWARD. TEMPERATURES ARE CURRENTLY IN THE 40S TO THE
NORTH OF I-4...RANGING TO THE 50S THROUGH CENTRAL FLORIDA AND IN THE
60S DOWN TOWARD FORT MYERS. COLD AIR ADVECTION AND ABUNDANT CLOUD
COVER WILL SLOW THE DIURNAL TEMP RISE AND MAKE TODAY THE COOLEST DAY
OF THE WEEK FOR MOST LOCATIONS.
OUR REGION RESIDES ON THE SOUTHERN PERIPHERY OF THE LONGWAVE TROUGH
WITHIN A FAST WESTERLY FLOW CONTAINING SEVERAL WEAK IMPULSES
STREAMING ACROSS THE GULF OF MEXICO. PLENTY OF LEFT OVER COLUMN
MOISTURE WILL ALLOW THESE IMPULSES ALONG WITH A FAVORABLE DIVERGENT
UPPER JET STRUCTURE TO PROVIDE A FEW PERIODS LIGHT SHOWERS THROUGH
THIS EVENING TO THE FORECAST AREA. THE FIRST IMPULSE THIS MORNING
WILL ALIGN WITH THIS JET TO PROVIDE THE BEST CHANCES FOR LIGHT
SHOWERS TO THE NORTH OF THE I-4 CORRIDOR...WITH THE SUBSEQUENT
FOLLOWING IMPULSES TRENDING MAINLY SOUTH OF THE TAMPA BAY AREA BY
THE EVENING HOURS ALONG WITH THE MORE EFFICIENT UPPER DIVERGENCE.
THIS TREND IS SHOWN BY THE LATEST RAP/HRRR GUIDANCE...ALONG WITH THE
GLOBAL GFS/ECMWF GUIDANCE. DUE TO THIS CONSENSUS AND SUPPORTING
SATELLITE TRENDS...THE FORECAST HAS BEEN TRENDED TOWARD THIS
PHILOSOPHY. THE WEAKNESS OF EACH IMPULSE...MEANS THAT THEIR SYNOPTIC
INFLUENCES WILL BE HIGHLY DEPENDENT ON JUST HOW WELL EACH OF THE NWP
GUIDANCE MEMBERS INITIALIZE. WILL BE WATCHING CLOSELY THROUGH THE
DAY TO FIND THOSE MEMBERS INITIALIZING THE CENTRAL GULF REGION THE
BEST...AND CONTINUE TO TREND TIMING/LOCATION OF THE SHOWER BATCHES
THROUGH THE NEXT 12-18 HOURS.
BY THE SECOND HALF OF TONIGHT...MOST OF THE SYNOPTIC SUPPORT FOR
LIFT ALONG WITH THE BEST COLUMN MOISTURE DEPARTS TO THE EAST OF
THE FORECAST AREA. WILL SHOW ANY LINGERING SHOWER CHANCES ENDING
OVER THE SOUTHERN ZONES. SURFACE HIGH PRESSURE WILL BE BUILDING IN
FROM THE NORTH WITH A COOL AND DRY AIRMASS BECOMING STRONGLY
ESTABLISHED FROM TAMPA BAY NORTHWARD. A FAVORABLE DRAINAGE FLOW
PATTERN LOOKS TO BRING ENOUGH COLD AIR SOUTHWARD THAT WE ARE
CONCERNED WITH TEMPS LATE NIGHT APPROACHING...OR EVEN DROPPING BELOW
FREEZING FOR A FEW HOURS ACROSS PARTS OF LEVY COUNTY. A FREEZE WATCH
IS CURRENTLY UP FOR LEVY COUNTY...AND WILL BE LOOKING CLOSELY AT THE
12Z GUIDANCE LATER THIS MORNING TO DETERMINE IF THE LIKELIHOOD OF
SUB-FREEZING TEMPS IS HIGH ENOUGH TO WARRANT AND UPGRADE TO A FREEZE
WARNING. IN TERMS OF FROST...THE DEWPOINT DEPRESSION IN THE MOS
GUIDANCE IS ALMOST TOO GREAT (5-7 DEGREES) TO SUPPORT MUCH FROST
FORMATION ACROSS LEVY COUNTY. HOWEVER...IF WE END UP DE-COUPLING THE
BOUNDARY LAYER LATE AT NIGHT...THEN THIS DIFFERENCE MAY END UP BEING
LESS. SLIGHTLY BETTER CHANCES FOR PATCHY FROST MAY ACTUALLY EXIST
SOUTH OF THE FREEZE WATCH ACROSS CITRUS/SUMTER AND HERNANDO COUNTIES
WHERE TEMPS ARE EXPECTED TO STAY JUST ABOVE FREEZING...BUT THE DRY
AIR INTRUSION WILL BE LESS. WILL ALSO LOOK AT THIS POTENTIAL...AND
WILL LIKELY ADD FROST INTO THE GRIDS FURTHER SOUTH THAN IS CURRENTLY
FORECAST WITH THE AFTERNOON PACKAGE. THE REST OF THE FORECAST AREA
WILL SEE LOW TEMPS IN THE 40S ACROSS CENTRAL FLORIDA AND INTO THE
LOWER/MID 50S DOWN TOWARD CHARLOTTE/LEE COUNTIES.
AFTER THE COOL START...FRIDAY WILL BEGIN A SEVERAL DAY STRETCH OF
FAIR WEATHER AND QUICKLY MODERATING TEMPERATURES. A GREAT LOOKING
WEEKEND IN TERMS OF SENSIBLE WEATHER APPEARS IN STORE.
&&
.AVIATION...
EXPECT LINGERING MVFR CIGS THROUGH THE MORNING ACROSS ALL TERMINALS.
WITH A SOME LIGHT SHOWERS MOVING SOUTH TODAY TERMINALS SOUTH OF SRQ
COULD SEE PERIODS OF MVFR CIGS EXTEND THROUGH THIS AFTERNOON. LIGHT
RAIN MAY PERSIST SOUTH OF TAMPA BAY THROUGH THE EVENING HOURS.
&&
.MARINE...
WINDS SHOULD GRADUALLY DIMINISH BELOW HEADLINE CRITERIA FOR ALL
AREAS INTO THE AFTERNOON AND EVENING HOURS. HIGH PRESSURE BUILDING
IN FROM THE NORTH TONIGHT AND FRIDAY WILL SET UP A PERIOD OF
GENERALLY LIGHT WINDS AND SEAS FOR THE UPCOMING WEEKEND. THE NEXT
POTENTIAL FOR A FRONTAL PASSAGE AND STRONGER WINDS/SEAS LOOKS TO
ARRIVE DURING NEXT TUESDAY AND TUESDAY NIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 63 47 69 56 / 30 10 0 0
FMY 73 56 75 57 / 30 20 10 0
GIF 66 48 73 55 / 30 10 0 0
SRQ 65 48 68 53 / 30 10 0 0
BKV 62 37 70 44 / 30 10 0 0
SPG 63 53 69 60 / 30 10 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...FREEZE WATCH FROM LATE TONIGHT THROUGH FRIDAY MORNING FOR
COASTAL LEVY-INLAND LEVY.
GULF WATERS...NONE.
&&
$$
UPDATE/MARINE...MROCZKA
AVIATION...BARRON
AREA FORECAST DISCUSSION
NWS PORTLAND OR
252 AM PST THU FEB 27 2014
.SYNOPSIS...A WEAK UPPER LOW JUST OFF THE SOUTH OREGON COAST EARLY
THIS MORNING WILL CONTINUE TO WEAKEN DURING THE DAY. A NARROW UPPER
LEVEL RIDGE DEVELOPS OVER THE FORECAST AREA TONIGHT. A COMPLEX
PATTERN DEVELOPS FRIDAY...WITH AN UPPER LOW OFF THE CENTRAL
CALIFORNIA COAST AND A COLD UPPER TROUGH IN CANADA. SOME OF THE COLD
CANADIAN AIR WILL SEEP SOUTH FROM THE CENTRAL WASHINGTON COLUMBIA
BASIN...REACHING THE COLUMBIA GORGE AND SOUTH WASHINGTON CASCADES
FRIDAY NIGHT. THIS COLD AIR LINGERS SATURDAY...FOR A THREAT OF
WINTER-TYPE PRECIPITATION TO THE CENTRAL COLUMBIA GORGE AND UPPER
HOOD RIVER VALLEY. MILDER WEST FLOW ALOFT FORCES THE COLD AIR EAST
BEGINNING SUNDAY. A WETTER AND MILDER PATTERN IS EXPECTED EARLY NEXT
WEEK.
&&
.SHORT TERM...THURSDAY THROUGH SATURDAY...LARGE-SCALE PATTERN EARLY
THIS MORNING INCLUDES A NARROW 500 MB RIDGE AXIS EXTENDING FROM
ALASKA THROUGH NWRN WA AND INTO NERN NV. THERE IS ALSO AN UPPER LOW
NEARING THE SRN OREGON COAST AND ANOTHER DEVELOPING LOW OUT AROUND
40N 150W. WATER VAPOR IMAGERY WOULD SUGGEST THAT THERE ARE TWO LOW
PRES CENTERS ASSOCIATED WITH THE TROUGH OFF THE SRN OREGON AND
CALIFORNIA COAST. STRONG JET WRAPPING AROUND AN APPARENT LOW CENTER
IN N CENTRAL CALIFORNIA...WITH ANOTHER CIRCULATION NEAR K4BK. DESPITE
DEEP SLY DIFFLUENT FLOW ALOFT PRECIP ACROSS THE FORECAST AREA HAS
BEEN RATHER MEAGER. KRTX DUAL-POL DOPPLER RADAR AT 10Z SHOWED A FEW
SHOWERS MOVING THROUGH THE SRN PART OF THE FORECAST AREA...PRIMARILY
THE CENTRAL OREGON COAST RANGE AND THE CENTRAL CASCADES AND
FOOTHILLS. THE 03Z HRRR COMPOSITE REFLECTIVITY LOOP VALID 10Z SEEMED
TO HAVE THE RIGHT IDEA BUT APPEARS TO BE A LITTLE OVERDONE.
MODELS STILL INSIST SOME SORT OF DEFORMATION ZONE WILL SET UP OVER
THE AREA THIS MORNING. THE UPPER LOW STALLS ALONG THE S OREGON COAST
TODAY AND FILLS. PRECIP WANES THIS AFTERNOON AND EVENING AS THE
DEFORMATION ZONE LOSES DEFINITION AND 500 MB HIGH PRES REBOUNDS. LEFT
CHANCE POPS 00Z-06Z FRI...WITH THE BEST CHANCES TO THE NORTH CLOSEST
TO WHATEVER IS LEFT OF THE DEFORMATION ZONE. COMPLICATED UPPER AIR
PATTERN EVOLVES LATER TONIGHT. GFS AND ECMWF HAVE A FAIRLY DEEP UPPER
LOW SITUATED NEAR 37N 132W AND A LARGE ELONGATED COLD UPPER TROUGH
OVER CENTRAL CANADA...WITH THE FORECAST AREA CAUGHT BETWEEN THESE TWO
FEATURES. COLD AIR ASSOCIATED WITH AN ARCTIC BOUNDARY ALONG THE
SLOPES OF THE ROCKIES STARTS TO SEEP INTO THE CENTRAL WASHINGTON
COLUMBIA BASIN LATE TONIGHT...BUT MORE SO FRI. ECMWF BRINGS MORE OF
THE COLD AIR SOUTHWARD ALONG THE ERN WA CASCADE SLOPES AND INTO THE
COLUMBIA GORGE. BY 00Z SAT THE ECMWF 0C 850 MB ISOTHERM IS NEAR KDLS
WHILE THE 0C GFS 850 ISOTHERM IS A LITTLE MORE NORTH.
ALL IN ALL...MUCH OF FRI WILL BE DRY. MOISTURE ASSOCIATED WITH THE
NRN CAL LOW STARTS TO WORK ITS WAY NORTHWARD LATE FRI AFTERNOON FOR A
MENTION OF SLIGHT CHANCE POPS ACROSS THE FAR SOUTH. THE PRIMARY
SHORT-TERM CONCERN WILL BE THE FRI NIGHT THROUGH SAT NIGHT PERIOD.
BOTH THE GFS AND ECMWF BRING A LITTLE MORE OF THE ARCTIC AIR THROUGH
THE COLUMBIA GORGE...WITH THE ECMWF A LITTLE MORE AGRESSIVE. THE
ECMWF HAS ABOUT -6C 850 MB TEMPS AT KDLS 12Z SAT WHILE THE GFS IS -2
TO -4C. BELIEVE THE NAM IS WAY TOO COLD AS A MODEL SOUNDING FOR KPDX
INDICATES SNOW SAT MORNING THEN TRANSITIONING TO -FZRA IN THE
AFTERNOON. GFS SOUNDING SEEMS MORE REALISTIC WITH POSSIBLY SOME
RAIN/SNOW MIX SAT MORNING THEN GOING TO ALL RAIN IN THE AFTERNOON.
NOT LOOKING AT MUCH IN THE WAY OF QPF FRI NIGHT AND SAT. TROUBLE
AREAS WILL BE FROM KCZK-K4S2 AND THE UPPER HOOD RIVER VALLEY.
WEISHAAR
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...ECMWF HANGS ON TO THE
COLD AIR MUCH LONGER THAN THE GFS. BY SUN MORNING THE GFS HAS THE
COLD AIR RETREATING TO THE EAST IN RESPONSE TO STRONG WLY FLOW ALOFT
TRYING TO PUSH INTO THE AREA. EVEN IF THE GFS IS TOO FAST ERADICATING
THE COLD AIR...BELIEVE THE SNOW AND ICE THREAT FOR THE CENTRAL GORGE
AND UPPER HOOD RIVER VALLEY ENDS LATE SUN OR SUN EVENING.
HOWEVER...PLENTY OF UNCERTAINTY WITH THIS PATTERN...BUT LATEST MODEL
TRENDS ARE SUGGESTING WHAT COLD AIR MAKES IT INTO THE GORGE WILL NOT
AS COLD OR PERSISTENT AS PREVIOUS RUNS DEPICTED. GUSTY EAST WIND WILL
CONTINUE TO FUNNEL THE COLD AIR FROM THE COLUMBIA BASIN EAST OF THE
CASCADES THROUGH THE GORGE LATE SATURDAY THROUGH SUN NIGHT. THE GFS
AND ECMWF HAVE MAJOR DISCREPANCIES REGARDING THE LOCATION OF THE MILD
WESTERLIES AND WHAT HAPPENS WITH THE COLD CANADIAN LOW. THE ECMWF
SHOWS THE COLD UPPER LOW RETROGRADING FURTHER WEST TO JUST N OF
VANCOUVER ISLAND BY 18Z MON WHILE THE GFS ATTEMPTS TO HAVE A FLAT
UPPER RIDGE BUILD OVER THE REGION. BIGGEST QUESTION IS HOW FAST THE
WESTERLIES BREAK THROUGH. ABOUT THE ONLY CONFIDENT DETAIL IS THAT THE
FIRST PART OF NEXT WEEK LOOKS RATHER WET. WEISHAAR
.AVIATION...12Z TAFS...FRONTAL SYSTEM APPROACHING FROM SOUTH IS
ONLY PRODUCING SPOTTY LIGHT RAIN AT THIS POINT...MAINLY NEAR KEUG.
AS A RESULT VFR CONDITIONS PREVAIL WITH CIGS GENERALLY ABOVE 5000
FEET. AREA OF STEADIER LIGHT RAIN IS EXPECTED TO SPREAD NORTH
ACROSS THE FORECAST AREA THIS MORNING...POSSIBLY RESULTING IN
BRIEF MVFR CONDITIONS. EAST WINDS CONTINUE TO GUST 20-30 KT NEAR
KTTD...THIS SHOULD COME TO AN END AS THE OCCLUDED FRONT PUSHES
NORTH ACROSS THE PDX METRO. AFTER THAT...LIGHT S-SW FLOW MAY HAVE
ENOUGH ONSHORE COMPONENT TO RESULT IN AREAS IFR ALONG THE COAST.
OTHERWISE RESIDUAL MOISTURE AND WEAK INSTABILITY WILL LEAD TO
AREAS OF MVFR INLAND THIS AFTERNOON WITH SCATTERED -SHRA...
TAPERING OFF THIS EVENING.
KPDX AND APPROACHES...VFR LIKELY TO PREVAIL THROUGH 16Z-18Z...
THEN INCREASING ODDS OF MVFR IN AREAS OF MORNING -RA AND SCATTERED
SHOWERS IN THE AFTERNOON. GUSTY EAST WINDS NEAR THE WEST END OF
THE COLUMBIA GORGE WILL EASE THROUGHOUT THE DAY. WEAGLE
&&
.MARINE...LOW PRESSURE OFF THE NORTHERN CALIFORNIA COAST CONTINUES
TO FILL AS IT DRIFTS NORTH INTO THE OREGON WATERS. LIGHT TO
MODERATE EAST WINDS WILL SHIFT SOUTHERLY BEHIND AN OCCLUDED FRONT
THIS MORNING...BUT WINDS SHOULD REMAIN MODERATE BEHIND THE FRONT.
THERE MAY BE A GUST OR TWO TO 25 KT...BUT LIKELY NOT WIDESPREAD
ENOUGH TO WARRANT A SMALL CRAFT ADVISORY. SEAS WILL BE A BIT
CONFUSED TODAY...WITH A COMBINATION OF LONGER PERIOD WESTERLY
SWELL AND SHORTER PERIOD SOUTHERLY SWELL. HOWEVER COMBINED SEA
HEIGHTS ARE EXPECTED TO REMAIN BELOW 10 FEET. SMALL CRAFT ADVISORY
FOR ROUGH BAR THIS AFTERNOON...MAINLY DUE TO THE VERY STRONG EBB
CURRENT ASSOCIATED WITH THE NEW MOON.
IN THE LONGER TERM...THE VERY ACTIVE PACIFIC STORM TRACK WILL
CONTINUE TO FOCUS ON CALIFORNIA. EVENTUALLY W-SW SWELL FROM ALL
THIS ACTIVITY WILL AFFECT OUR WATERS...LATER IN THE WEEKEND AND
INTO EARLY NEXT WEEK. WEAGLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM
1 PM TO 5 PM PST THIS AFTERNOON.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
657 AM EST THU FEB 27 2014
.SYNOPSIS...
A SHARP COLD FRONT WILL SWEEP THROUGH THE AREA TODAY...REINFORCING
THE ARCTIC AIR MASS OVER PENNSYLVANIA. A SOUTHERN STREAM
SHORTWAVE WILL LIFT TOWARD PA LATE THIS WEEKEND. THE ASSOCIATED
SFC LOW WILL LIKELY TRACK JUST SOUTH OF PA...PRODUCING SIGNIFICANT
WINTRY PRECIPITATION ACROSS THE REGION SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NEAR TERM MDL DATA INDICATES A BIT OF LIGHT SNOW WILL WORK INTO
THE NW MTNS BY ARND DAWN...IN RESPONSE TO ARRIVAL OF SWRLY LL JET
AND ASSOC WEAK WAA. A SHARP UPPER TROF AND REINFORCING SHOT OF
ARCTIC AIR WILL BLAST THRU THE AREA LATER TODAY...ACCOMPANIED BY
SNOW SHOWERS AND SQUALLS...MAINLY OVR NORTHERN PA. STEEP LOWER
TROPOSPHERIC LAPSE RATES ALONG WITH A GOOD ISALLOBARIC COMPONENT
AND SFC BASED CAPES UP TO 150 J/KG POINT TOWARD THE LIKELIHOOD OF
SNOW SQUALLS LATE THIS MORNING AND AFTERNOON ACROSS THE NORTHERN
HALF OF THE STATE. LATEST RAP AND NAMPARA SIMULATED REFLECTIVITY
NOW PICKING UP ON THE SQUALL THREAT WITH A NARROW BAND OF HIGHER
RETURNS ALONG THE COLD FRONT...WHICH SHOULD ARRIVE OVER THE NW
MTNS BY LATE MORNING AND EXIT THE EASTERN COUNTIES BY 21Z. SFC
TEMPS SHOULD BE WELL BELOW FREEZING...SO THREAT OF A FLASH FREEZE
APPEARS MINIMAL. HOWEVER...LOW VISIBILITIES AND A QUICK INCH OR SO
OF ACCUMULATION IS LIKELY OVER AREAS ESPECIALLY NORTH OF I80.
THE OTHER CONCERN WILL BE DANGEROUS WCHILLS...AS STRONG WINDS
COMBINE WITH FALLING TEMPS DURING THE AFTN. STRONG SUBSIDENCE AND
SFC PRES RISES INDICATED DURING THE AFTN...WHEN BUFKIT SOUNDINGS
SUPPORT GUSTS TO NEAR 40KTS. HAVE ISSUED WIND CHILL ADVISORY FOR
THE ALLEGHENY PLATEAU STARTING LATE THIS AFTN...WHEN APPARENT
TEMPS BEGIN TO APPROACH -15F. MDL SOUNDINGS DO INDICATE THE
LIKELIHOOD OF A FEW GUSTS THIS AFTN IN EXCESS OF 40KTS...MAINLY
OVR THE LAURELS/SC MTNS. HOWEVER...BIG STORY WILL BE THE COLD...SO
WILL INCLUDE MENTION OF WGUSTS IN THE WCHILL ADV AND NOT ISSUE A
SEPARATE WIND ADV ATTM.
MAX TEMPS THIS AFTERNOON SHOULD RANGE FROM ONLY 10 ABOVE ACROSS
THE NW MTNS TO THE MID TO UPPER 20S SOUTHEAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CORE OF THE COLDEST AIR ROTATES THRU CENTRAL PA TONIGHT WITH 8H
TEMPS DIPPING TO BTWN -20C AND -24C. THIS BONE DRY ARCTIC AIR MASS
WILL GATHER LITTLE MOISTURE FROM THE MOSTLY FROZEN GRT LKS.
THUS...EXPECT VERY LITTLE IN THE WAY OF POST-FRONTAL SNOW
SHOWERS. HAVE INCLUDED ONLY A SLGHT CHC OF MEASURABLE SNOW THIS
EVENING ACROSS WARREN CO. THIS ARCTIC AIR MASS WILL BE ACCOMPANIED
BY A GUSTY NW WIND DURING THE EVENING. HOWEVER...ARRIVAL OF HIGH
PRES TOWARDS DAWN SHOULD CAUSE THE WIND TO RELENT. THE DIMINISHING
WIND...CLEARING SKIES AND SNOW COVER SHOULD ALLOW TEMPS TO FALL
WELL BLW ZERO ACROSS THE ALLEGHENY PLATEAU AND TO NEAR ZERO ACROSS
THE SUSQ VALLEY. NO RECORD LOWS EXPECTED DUE TO A FRIGID MORNING
BACK IN 1934.
MSUNNY SKIES AND LGT WIND ASSOC WITH SFC HIGH PRESSURE SYSTEM WILL
MAKE CONDITIONS FEEL LESS HARSH ON FRIDAY. HOWEVER...ENSEMBLE MEAN
925TEMPS OF ARND -15C SHOULD SUPPORT MAX TEMPS NO BETTER THAN THE
TEENS TO NR 20F...ARND 25F BELOW NORMAL FOR LATE FEBRUARY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
DEEP UPPER TROF IS PROGGED TO RAPIDLY LIFT OUT BY SATURDAY...ALLOWING
MILDER AIR TO WORK INTO THE STATE. PLENTY OF CLOUDS SHOULD
ACCOMPANY THE RETURN OF MILDER WX SAT AND PERHAPS A BIT OF VERY
LGT SNOW...AS SOUTHERLY FLOW OVERRUNS RETREATING ARCTIC AIR MASS.
BLEND OF LATEST MED RANGE QPF SUGGEST ANY ACCUMS WOULD BE VERY
LIGHT AND CONFINED TO THE NW MTNS.
NORTHERN STREAM SHORTWAVE PASSING N OF THE GRT LKS WILL PUSH A
DYING COLD FRONT THRU CENTRAL PA SAT NIGHT. A FEW -SHSN MAY
ACCOMPANY PASSAGE OF THIS FRONT OVR THE N MTNS...WHILE AIR MASS
ACTUALLY BECOMES MILD ENOUGH FOR EITHER -SHRA OR -SHSN OVER SOUTH.
CONSALL AND OPER EC BOTH SUPPORT MILD TEMPS SAT NIGHT ACROSS
SOUTHERN PA...WITH READINGS ONLY FALLING TO ARND 32F.
FOCUS OF THE MED RANGE FCST REMAINS ON SOUTHERN STREAM DISTURBANCE
LIFTING TOWARD PA LATE IN THE WEEKEND. CONFIDENCE CONTINUES TO
INCREASE IN A SIGNIFICANT BOUT OF WINTRY PRECIP FOR MUCH OF
CENTRAL PA SUNDAY INTO MONDAY...AS PLUME OF GULF OF MEX MOISTURE
OVERRUNS A QUASI-STATIONARY BNDRY JUST S OF THE MASON DIXON. BOTH
GEFS AND OPER EC/CMC SUGGEST THERE WILL BE A NARROW SWATH OF
GREATER THAN AN INCH PRECIP ACROSS CENTRAL OR SOUTHERN PA. BEST
CHC FOR SIGNIFICANT SNOW STILL APPEARS TO BE ACROSS CENTRAL/NORTHERN
PA...WITH A GREATER CHC OF A WINTRY MIX OR RAIN IN THE SOUTH.
BULK OF MED RANGE GUIDANCE INDICATES FAIR AND COLD WX TUE/WED...AS
LG SFC HIGH PRES SYSTEM BUILDS SE TOWARDS PA FROM CENTRAL CANADA.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
27/12Z...ARCTIC FRONT MOVG THRU NW OH WILL CONT TO SURGE EWD ACRS
THE AIRSPACE BY LATE THIS AFTN. -SHSN BREAKING OUT NOW ACRS NWRN PA
WITH VIS RUNNING BTWN 1-3SM. FINAL CHANGES FOR THE 12Z SCHEDULED
ISSUANCE INCLUDED INC WND GUSTS AND ADDING 15/16Z TEMPO FOR SNSQ
AT BFD..DROPPING VIS TO 1/4SM. THIS MAY OCCUR AT OTHER WRN/CNTRL
STIES BTWN 16-19Z.
27/09Z...VERY MINOR CHANGES TO TIMING OF SHSN/SNSQ ASSOCD WITH
ARCTIC FROPA...WHICH IS CURRENTLY NEAR DTW. MVFR CIGS INVADING
BFD WITH WINDS PICKING UP ACRS WRN SXNS.
27/06Z...VFR CONDITIONS EXPECTED THRU 12Z. ARCTIC FROPA WILL BLAST
THRU THE AIRSPACE BTWN 13-21Z ACCOMPANIED BY SNOW SHOWERS AND
LCL/BRIEF +SHSN/SNSQ. REDUCTIONS TO VIS /IFR CATG OR LOWER/ ARE
LKLY OVR THE WRN/CNTRL TAF SITES WITH THE LOWER VISBYS PERSISTING
THE LONGEST AT JST/BFD INTO THE AFTN. STRONG GUSTY WND SHFT FROM
WSW TO WNW WILL ALSO OCCUR WITH PEAK GUSTS AROUND 30KTS...WHICH
COULD CONTRIBUTE TO LOWER VIS IN AREAS OF BLSN. KEPT VIS AT MVFR
INTO THE MDT/LNS VCNTY BUT GIVEN SHARPNESS/INSTABILITY ALONG THE
REINFORCING ARCTIC FRONT..CANT RULE OUT A BRIEF IFR RESTRICTION
HERE. DOWNSLOPE FLOW IN THE WAKE OF THE FRONT SHOULD BRING ALL
SITES E OF THE MTS BACK TO VFR WHILE MVFR CIGS/OCNL -SHSN LINGER
ACRS WRN SXNS. SFC HIGH PRES BUILDS INTO THE REGION TNGT ALLOWING
WINDS TO SUBSIDE INTO FRI MORNING.
OUTLOOK...
FRI...VFR.
SAT...VFR TRENDING LOWER INTO SAT NGT IN -SN.
SUN-MON...MVFR/IFR LKLY IN SN AND/OR MIXED PCPN.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 3 PM THIS AFTERNOON TO 10 AM EST
FRIDAY FOR PAZ004>006-010>012-017-018-024-033-037-041-042.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
619 AM EST THU FEB 27 2014
.SYNOPSIS...
A SHARP COLD FRONT WILL SWEEP THROUGH THE AREA TODAY...REINFORCING
THE ARCTIC AIR MASS OVER PENNSYLVANIA. A SOUTHERN STREAM
SHORTWAVE WILL LIFT TOWARD PA LATE THIS WEEKEND. THE ASSOCIATED
SFC LOW WILL LIKELY TRACK JUST SOUTH OF PA...PRODUCING SIGNIFICANT
WINTRY PRECIPITATION ACROSS THE REGION SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NEAR TERM MDL DATA INDICATES A BIT OF LIGHT SNOW WILL WORK INTO
THE NW MTNS BY ARND DAWN...IN RESPONSE TO ARRIVAL OF SWRLY LL JET
AND ASSOC WEAK WAA. A SHARP UPPER TROF AND REINFORCING SHOT OF
ARCTIC AIR WILL BLAST THRU THE AREA LATER TODAY...ACCOMPANIED BY
SNOW SHOWERS AND SQUALLS...MAINLY OVR NORTHERN PA. STEEP LOWER
TROPOSPHERIC LAPSE RATES ALONG WITH A GOOD ISALLOBARIC COMPONENT
AND SFC BASED CAPES UP TO 150 J/KG POINT TOWARD THE LIKELIHOOD OF
SNOW SQUALLS LATE THIS MORNING AND AFTERNOON ACROSS THE NORTHERN
HALF OF THE STATE. LATEST RAP AND NAMPARA SIMULATED REFLECTIVITY
NOW PICKING UP ON THE SQUALL THREAT WITH A NARROW BAND OF HIGHER
RETURNS ALONG THE COLD FRONT...WHICH SHOULD ARRIVE OVER THE NW
MTNS BY LATE MORNING AND EXIT THE EASTERN COUNTIES BY 21Z. SFC
TEMPS SHOULD BE WELL BELOW FREEZING...SO THREAT OF A FLASH FREEZE
APPEARS MINIMAL. HOWEVER...LOW VISIBILITIES AND A QUICK INCH OR SO
OF ACCUMULATION IS LIKELY OVER AREAS ESPECIALLY NORTH OF I80.
THE OTHER CONCERN WILL BE DANGEROUS WCHILLS...AS STRONG WINDS
COMBINE WITH FALLING TEMPS DURING THE AFTN. STRONG SUBSIDENCE AND
SFC PRES RISES INDICATED DURING THE AFTN...WHEN BUFKIT SOUNDINGS
SUPPORT GUSTS TO NEAR 40KTS. HAVE ISSUED WIND CHILL ADVISORY FOR
THE ALLEGHENY PLATEAU STARTING LATE THIS AFTN...WHEN APPARENT
TEMPS BEGIN TO APPROACH -15F. MDL SOUNDINGS DO INDICATE THE
LIKELIHOOD OF A FEW GUSTS THIS AFTN IN EXCESS OF 40KTS...MAINLY
OVR THE LAURELS/SC MTNS. HOWEVER...BIG STORY WILL BE THE COLD...SO
WILL INCLUDE MENTION OF WGUSTS IN THE WCHILL ADV AND NOT ISSUE A
SEPARATE WIND ADV ATTM.
MAX TEMPS THIS AFTERNOON SHOULD RANGE FROM ONLY 10 ABOVE ACROSS
THE NW MTNS TO THE MID TO UPPER 20S SOUTHEAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CORE OF THE COLDEST AIR ROTATES THRU CENTRAL PA TONIGHT WITH 8H
TEMPS DIPPING TO BTWN -20C AND -24C. THIS BONE DRY ARCTIC AIR MASS
WILL GATHER LITTLE MOISTURE FROM THE MOSTLY FROZEN GRT LKS.
THUS...EXPECT VERY LITTLE IN THE WAY OF POST-FRONTAL SNOW
SHOWERS. HAVE INCLUDED ONLY A SLGHT CHC OF MEASURABLE SNOW THIS
EVENING ACROSS WARREN CO. THIS ARCTIC AIR MASS WILL BE ACCOMPANIED
BY A GUSTY NW WIND DURING THE EVENING. HOWEVER...ARRIVAL OF HIGH
PRES TOWARDS DAWN SHOULD CAUSE THE WIND TO RELENT. THE DIMINISHING
WIND...CLEARING SKIES AND SNOW COVER SHOULD ALLOW TEMPS TO FALL
WELL BLW ZERO ACROSS THE ALLEGHENY PLATEAU AND TO NEAR ZERO ACROSS
THE SUSQ VALLEY. NO RECORD LOWS EXPECTED DUE TO A FRIGID MORNING
BACK IN 1934.
MSUNNY SKIES AND LGT WIND ASSOC WITH SFC HIGH PRESSURE SYSTEM WILL
MAKE CONDITIONS FEEL LESS HARSH ON FRIDAY. HOWEVER...ENSEMBLE MEAN
925TEMPS OF ARND -15C SHOULD SUPPORT MAX TEMPS NO BETTER THAN THE
TEENS TO NR 20F...ARND 25F BELOW NORMAL FOR LATE FEBRUARY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
DEEP UPPER TROF IS PROGGED TO RAPIDLY LIFT OUT BY SATURDAY...ALLOWING
MILDER AIR TO WORK INTO THE STATE. PLENTY OF CLOUDS SHOULD
ACCOMPANY THE RETURN OF MILDER WX SAT AND PERHAPS A BIT OF VERY
LGT SNOW...AS SOUTHERLY FLOW OVERRUNS RETREATING ARCTIC AIR MASS.
BLEND OF LATEST MED RANGE QPF SUGGEST ANY ACCUMS WOULD BE VERY
LIGHT AND CONFINED TO THE NW MTNS.
NORTHERN STREAM SHORTWAVE PASSING N OF THE GRT LKS WILL PUSH A
DYING COLD FRONT THRU CENTRAL PA SAT NIGHT. A FEW -SHSN MAY
ACCOMPANY PASSAGE OF THIS FRONT OVR THE N MTNS...WHILE AIR MASS
ACTUALLY BECOMES MILD ENOUGH FOR EITHER -SHRA OR -SHSN OVER SOUTH.
CONSALL AND OPER EC BOTH SUPPORT MILD TEMPS SAT NIGHT ACROSS
SOUTHERN PA...WITH READINGS ONLY FALLING TO ARND 32F.
FOCUS OF THE MED RANGE FCST REMAINS ON SOUTHERN STREAM DISTURBANCE
LIFTING TOWARD PA LATE IN THE WEEKEND. CONFIDENCE CONTINUES TO
INCREASE IN A SIGNIFICANT BOUT OF WINTRY PRECIP FOR MUCH OF
CENTRAL PA SUNDAY INTO MONDAY...AS PLUME OF GULF OF MEX MOISTURE
OVERRUNS A QUASI-STATIONARY BNDRY JUST S OF THE MASON DIXON. BOTH
GEFS AND OPER EC/CMC SUGGEST THERE WILL BE A NARROW SWATH OF
GREATER THAN AN INCH PRECIP ACROSS CENTRAL OR SOUTHERN PA. BEST
CHC FOR SIGNIFICANT SNOW STILL APPEARS TO BE ACROSS CENTRAL/NORTHERN
PA...WITH A GREATER CHC OF A WINTRY MIX OR RAIN IN THE SOUTH.
BULK OF MED RANGE GUIDANCE INDICATES FAIR AND COLD WX TUE/WED...AS
LG SFC HIGH PRES SYSTEM BUILDS SE TOWARDS PA FROM CENTRAL CANADA.
&&
.AVIATION /11Z THURSDAY THROUGH MONDAY/...
27/09Z...VERY MINOR CHANGES TO TIMING OF SHSN/SNSQ ASSOCD WITH
ARCTIC FROPA...WHICH IS CURRENTLY NEAR DTW. MVFR CIGS INVADING
BFD WITH WINDS PICKING UP ACRS WRN SXNS.
27/06Z...VFR CONDITIONS EXPECTED THRU 12Z. ARCTIC FROPA WILL BLAST
THRU THE AIRSPACE BTWN 13-21Z ACCOMPANIED BY SNOW SHOWERS AND
LCL/BRIEF +SHSN/SNSQ. REDUCTIONS TO VIS /IFR CATG OR LOWER/ ARE
LKLY OVR THE WRN/CNTRL TAF SITES WITH THE LOWER VISBYS PERSISTING
THE LONGEST AT JST/BFD INTO THE AFTN. STRONG GUSTY WND SHFT FROM
WSW TO WNW WILL ALSO OCCUR WITH PEAK GUSTS AROUND 30KTS...WHICH
COULD CONTRIBUTE TO LOWER VIS IN AREAS OF BLSN. KEPT VIS AT MVFR
INTO THE MDT/LNS VCNTY BUT GIVEN SHARPNESS/INSTABILITY ALONG THE
REINFORCING ARCTIC FRONT..CANT RULE OUT A BRIEF IFR RESTRICTION
HERE. DOWNSLOPE FLOW IN THE WAKE OF THE FRONT SHOULD BRING ALL
SITES E OF THE MTS BACK TO VFR WHILE MVFR CIGS/OCNL -SHSN LINGER
ACRS WRN SXNS. SFC HIGH PRES BUILDS INTO THE REGION TNGT ALLOWING
WINDS TO SUBSIDE INTO FRI MORNING.
OUTLOOK...
FRI...VFR.
SAT...VFR TRENDING LOWER INTO SAT NGT IN -SN.
SUN-MON...MVFR/IFR LKLY IN SN AND/OR MIXED PCPN.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 3 PM THIS AFTERNOON TO 10 AM EST
FRIDAY FOR PAZ004>006-010>012-017-018-024-033-037-041-042.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
532 AM EST THU FEB 27 2014
.SYNOPSIS...
A SHARP COLD FRONT WILL SWEEP THROUGH THE AREA TODAY...REINFORCING
THE ARCTIC AIR MASS OVER PENNSYLVANIA. A SOUTHERN STREAM
SHORTWAVE WILL LIFT TOWARD PA LATE THIS WEEKEND. THE ASSOCIATED
SFC LOW WILL LIKELY TRACK JUST SOUTH OF PA...PRODUCING SIGNIFICANT
WINTRY PRECIPITATION ACROSS THE REGION SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NEAR TERM MDL DATA INDICATES A BIT OF LIGHT SNOW WILL WORK INTO
THE NW MTNS BY ARND DAWN...IN RESPONSE TO ARRIVAL OF SWRLY LL JET
AND ASSOC WEAK WAA. A SHARP UPPER TROF AND REINFORCING SHOT OF
ARCTIC AIR WILL BLAST THRU THE AREA LATER TODAY...ACCOMPANIED BY
SNOW SHOWERS AND SQUALLS...MAINLY OVR NORTHERN PA. STEEP LOWER
TROPOSPHERIC LAPSE RATES ALONG WITH A GOOD ISALLOBARIC COMPONENT
AND SFC BASED CAPES UP TO 150 J/KG POINT TOWARD THE LIKELIHOOD OF
SNOW SQUALLS LATE THIS MORNING AND AFTERNOON ACROSS THE NORTHERN
HALF OF THE STATE. LATEST RAP AND NAMPARA SIMULATED REFLECTIVITY
NOW PICKING UP ON THE SQUALL THREAT WITH A NARROW BAND OF HIGHER
RETURNS ALONG THE COLD FRONT...WHICH SHOULD ARRIVE OVER THE NW
MTNS BY LATE MORNING AND EXIT THE EASTERN COUNTIES BY 21Z. SFC
TEMPS SHOULD BE WELL BELOW FREEZING...SO THREAT OF A FLASH FREEZE
APPEARS MINIMAL. HOWEVER...LOW VISIBILITIES AND A QUICK INCH OR SO
OF ACCUMULATION IS LIKELY OVER AREAS ESPECIALLY NORTH OF I80.
THE OTHER CONCERN WILL BE DANGEROUS WCHILLS...AS STRONG WINDS
COMBINE WITH FALLING TEMPS DURING THE AFTN. STRONG SUBSIDENCE AND
SFC PRES RISES INDICATED DURING THE AFTN...WHEN BUFKIT SOUNDINGS
SUPPORT GUSTS TO NEAR 40KTS. HAVE ISSUED WIND CHILL ADVISORY FOR
THE ALLEGHENY PLATEAU STARTING LATE THIS AFTN...WHEN APPARENT
TEMPS BEGIN TO APPROACH -15F. MDL SOUNDINGS DO INDICATE THE
LIKELIHOOD OF A FEW GUSTS THIS AFTN IN EXCESS OF 40KTS...MAINLY
OVR THE LAURELS/SC MTNS. HOWEVER...BIG STORY WILL BE THE COLD...SO
WILL INCLUDE MENTION OF WGUSTS IN THE WCHILL ADV AND NOT ISSUE A
SEPARATE WIND ADV ATTM.
MAX TEMPS THIS AFTERNOON SHOULD RANGE FROM ONLY 10 ABOVE ACROSS
THE NW MTNS TO THE MID TO UPPER 20S SOUTHEAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CORE OF THE COLDEST AIR ROTATES THRU CENTRAL PA TONIGHT WITH 8H
TEMPS DIPPING TO BTWN -20C AND -24C. THIS BONE DRY ARCTIC AIR MASS
WILL GATHER LITTLE MOISTURE FROM THE MOSTLY FROZEN GRT LKS.
THUS...EXPECT VERY LITTLE IN THE WAY OF POST-FRONTAL SNOW
SHOWERS. HAVE INCLUDED ONLY A SLGHT CHC OF MEASURABLE SNOW THIS
EVENING ACROSS WARREN CO. THIS ARCTIC AIR MASS WILL BE ACCOMPANIED
BY A GUSTY NW WIND DURING THE EVENING. HOWEVER...ARRIVAL OF HIGH
PRES TOWARDS DAWN SHOULD CAUSE THE WIND TO RELENT. THE DIMINISHING
WIND...CLEARING SKIES AND SNOW COVER SHOULD ALLOW TEMPS TO FALL
WELL BLW ZERO ACROSS THE ALLEGHENY PLATEAU AND TO NEAR ZERO ACROSS
THE SUSQ VALLEY. NO RECORD LOWS EXPECTED DUE TO A FRIGID MORNING
BACK IN 1934.
MSUNNY SKIES AND LGT WIND ASSOC WITH SFC HIGH PRESSURE SYSTEM WILL
MAKE CONDITIONS FEEL LESS HARSH ON FRIDAY. HOWEVER...ENSEMBLE MEAN
925TEMPS OF ARND -15C SHOULD SUPPORT MAX TEMPS NO BETTER THAN THE
TEENS TO NR 20F...ARND 25F BELOW NORMAL FOR LATE FEBRUARY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
DEEP UPPER TROF IS PROGGED TO RAPIDLY LIFT OUT BY SATURDAY...ALLOWING
MILDER AIR TO WORK INTO THE STATE. PLENTY OF CLOUDS SHOULD
ACCOMPANY THE RETURN OF MILDER WX SAT AND PERHAPS A BIT OF VERY
LGT SNOW...AS SOUTHERLY FLOW OVERRUNS RETREATING ARCTIC AIR MASS.
BLEND OF LATEST MED RANGE QPF SUGGEST ANY ACCUMS WOULD BE VERY
LIGHT AND CONFINED TO THE NW MTNS.
NORTHERN STREAM SHORTWAVE PASSING N OF THE GRT LKS WILL PUSH A
DYING COLD FRONT THRU CENTRAL PA SAT NIGHT. A FEW -SHSN MAY
ACCOMPANY PASSAGE OF THIS FRONT OVR THE N MTNS...WHILE AIR MASS
ACTUALLY BECOMES MILD ENOUGH FOR EITHER -SHRA OR -SHSN OVER SOUTH.
CONSALL AND OPER EC BOTH SUPPORT MILD TEMPS SAT NIGHT ACROSS
SOUTHERN PA...WITH READINGS ONLY FALLING TO ARND 32F.
FOCUS OF THE MED RANGE FCST REMAINS ON SOUTHERN STREAM DISTURBANCE
LIFTING TOWARD PA LATE IN THE WEEKEND. CONFIDENCE CONTINUES TO
INCREASE IN A SIGNIFICANT BOUT OF WINTRY PRECIP FOR MUCH OF
CENTRAL PA SUNDAY INTO MONDAY...AS PLUME OF GULF OF MEX MOISTURE
OVERRUNS A QUASI-STATIONARY BNDRY JUST S OF THE MASON DIXON. BOTH
GEFS AND OPER EC/CMC SUGGEST THERE WILL BE A NARROW SWATH OF
GREATER THAN AN INCH PRECIP ACROSS CENTRAL OR SOUTHERN PA. BEST
CHC FOR SIGNIFICANT SNOW STILL APPEARS TO BE ACROSS CENTRAL/NORTHERN
PA...WITH A GREATER CHC OF A WINTRY MIX OR RAIN IN THE SOUTH.
BULK OF MED RANGE GUIDANCE INDICATES FAIR AND COLD WX TUE/WED...AS
LG SFC HIGH PRES SYSTEM BUILDS SE TOWARDS PA FROM CENTRAL CANADA.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
27/09Z...VERY MINOR CHANGES TO TIMING OF SHSN/SNSQ ASSOCD WITH
ARCTIC FROPA...WHICH IS CURRENTLY NEAR DTW. MVFR CIGS INVADING
BFD WITH WINDS PICKING UP ACRS WRN SXNS.
27/06Z...VFR CONDITIONS EXPECTED THRU 12Z. ARCTIC FROPA WILL BLAST
THRU THE AIRSPACE BTWN 13-21Z ACCOMPANIED BY SNOW SHOWERS AND
LCL/BRIEF +SHSN/SNSQ. REDUCTIONS TO VIS /IFR CATG OR LOWER/ ARE
LKLY OVR THE WRN/CNTRL TAF SITES WITH THE LOWER VISBYS PERSISTING
THE LONGEST AT JST/BFD INTO THE AFTN. STRONG GUSTY WND SHFT FROM
WSW TO WNW WILL ALSO OCCUR WITH PEAK GUSTS AROUND 30KTS...WHICH
COULD CONTRIBUTE TO LOWER VIS IN AREAS OF BLSN. KEPT VIS AT MVFR
INTO THE MDT/LNS VCNTY BUT GIVEN SHARPNESS/INSTABILITY ALONG THE
REINFORCING ARCTIC FRONT..CANT RULE OUT A BRIEF IFR RESTRICTION
HERE. DOWNSLOPE FLOW IN THE WAKE OF THE FRONT SHOULD BRING ALL
SITES E OF THE MTS BACK TO VFR WHILE MVFR CIGS/OCNL -SHSN LINGER
ACRS WRN SXNS. SFC HIGH PRES BUILDS INTO THE REGION TNGT ALLOWING
WINDS TO SUBSIDE INTO FRI MORNING.
OUTLOOK...
FRI...VFR.
SAT...VFR TRENDING LOWER INTO SAT NGT IN -SN.
SUN-MON...MVFR/IFR LKLY IN SN AND/OR MIXED PCPN.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 3 PM THIS AFTERNOON TO 10 AM EST
FRIDAY FOR PAZ004>006-010>012-017-018-024-033-037-041-042.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
527 AM EST THU FEB 27 2014
.SYNOPSIS...
A SHARP COLD FRONT WILL SWEEP THROUGH THE AREA TODAY...REINFORCING
THE ARCTIC AIR MASS OVER PENNSYLVANIA. A SOUTHERN STREAM
SHORTWAVE WILL LIFT TOWARD PA LATE THIS WEEKEND. THE ASSOCIATED
SFC LOW WILL LIKELY TRACK JUST SOUTH OF PA...PRODUCING SIGNIFICANT
WINTRY PRECIPITATION ACROSS THE REGION SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NEAR TERM MDL DATA INDICATES A BIT OF LIGHT SNOW WILL WORK INTO
THE NW MTNS BY ARND DAWN...IN RESPONSE TO ARRIVAL OF SWRLY LL JET
AND ASSOC WEAK WAA. A SHARP UPPER TROF AND REINFORCING SHOT OF
ARCTIC AIR WILL BLAST THRU THE AREA LATER TODAY...ACCOMPANIED BY
SNOW SHOWERS AND SQUALLS...MAINLY OVR NORTHERN PA. STEEP LOWER
TROPOSPHERIC LAPSE RATES ALONG WITH A GOOD ISALLOBARIC COMPONENT
AND SFC BASED CAPES UP TO 150 J/KG POINT TOWARD THE LIKELIHOOD OF
SNOW SQUALLS LATE THIS MORNING AND AFTERNOON ACROSS THE NORTHERN
HALF OF THE STATE. LATEST RAP AND NAMPARA SIMULATED REFLECTIVITY
NOW PICKING UP ON THE SQUALL THREAT WITH A NARROW BAND OF HIGHER
RETURNS ALONG THE COLD FRONT...WHICH SHOULD ARRIVE OVER THE NW
MTNS BY LATE MORNING AND EXIT THE EASTERN COUNTIES BY 21Z. SFC
TEMPS SHOULD BE WELL BELOW FREEZING...SO THREAT OF A FLASH FREEZE
APPEARS MINIMAL. HOWEVER...LOW VISIBILITIES AND A QUICK INCH OR SO
OF ACCUMULATION IS LIKELY OVER AREAS ESPECIALLY NORTH OF I80.
THE OTHER CONCERN WILL BE DANGEROUS WCHILLS...AS STRONG WINDS
COMBINE WITH FALLING TEMPS DURING THE AFTN. STRONG SUBSIDENCE AND
SFC PRES RISES INDICATED DURING THE AFTN...WHEN BUFKIT SOUNDINGS
SUPPORT GUSTS TO NEAR 40KTS. HAVE ISSUED WIND CHILL ADVISORY FOR
THE ALLEGHENY PLATEAU STARTING LATE THIS AFTN...WHEN APPARENT
TEMPS BEGIN TO APPROACH -15F. MDL SOUNDINGS DO INDICATE THE
LIKELIHOOD OF A FEW GUSTS THIS AFTN IN EXCESS OF 40KTS...MAINLY
OVR THE LAURELS/SC MTNS. HOWEVER...BIG STORY WILL BE THE COLD...SO
WILL INCLUDE MENTION OF WGUSTS IN THE WCHILL ADV AND NOT ISSUE A
SEPARATE WIND ADV ATTM.
MAX TEMPS THIS AFTERNOON SHOULD RANGE FROM ONLY 10 ABOVE ACROSS
THE NW MTNS TO THE MID TO UPPER 20S SOUTHEAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CORE OF THE COLDEST AIR ROTATES THRU CENTRAL PA TONIGHT WITH 8H
TEMPS DIPPING TO BTWN -20C AND -24C. THIS BONE DRY ARCTIC AIR MASS
WILL GATHER LITTLE MOISTURE FROM THE MOSTLY FROZEN GRT LKS.
THUS...EXPECT VERY LITTLE IN THE WAY OF POST-FRONTAL SNOW
SHOWERS. HAVE INCLUDED ONLY A SLGHT CHC OF MEASURABLE SNOW THIS
EVENING ACROSS WARREN CO. THIS ARCTIC AIR MASS WILL BE ACCOMPANIED
BY A GUSTY NW WIND DURING THE EVENING. HOWEVER...ARRIVAL OF HIGH
PRES TOWARDS DAWN SHOULD CAUSE THE WIND TO RELENT. THE DIMINISHING
WIND...CLEARING SKIES AND SNOW COVER SHOULD ALLOW TEMPS TO FALL
WELL BLW ZERO ACROSS THE ALLEGHENY PLATEAU AND TO NEAR ZERO ACROSS
THE SUSQ VALLEY. NO RECORD LOWS EXPECTED DUE TO A FRIGID MORNING
BACK IN 1934.
MSUNNY SKIES AND LGT WIND ASSOC WITH SFC HIGH PRESSURE SYSTEM WILL
MAKE CONDITIONS FEEL LESS HARSH ON FRIDAY. HOWEVER...ENSEMBLE MEAN
925TEMPS OF ARND -15C SHOULD SUPPORT MAX TEMPS NO BETTER THAN THE
TEENS TO NR 20F...ARND 25F BELOW NORMAL FOR LATE FEBRUARY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
DEEP UPPER TROF IS PROGGED TO RAPIDLY LIFT OUT BY SATURDAY...ALLOWING
MILDER AIR TO WORK INTO THE STATE. PLENTY OF CLOUDS SHOULD
ACCOMPANY THE RETURN OF MILDER WX SAT AND PERHAPS A BIT OF VERY
LGT SNOW...AS SOUTHERLY FLOW OVERRUNS RETREATING ARCTIC AIR MASS.
BLEND OF LATEST MED RANGE QPF SUGGEST ANY ACCUMS WOULD BE VERY
LIGHT AND CONFINED TO THE NW MTNS.
NORTHERN STREAM SHORTWAVE PASSING N OF THE GRT LKS WILL PUSH A
DYING COLD FRONT THRU CENTRAL PA SAT NIGHT. A FEW -SHSN MAY
ACCOMPANY PASSAGE OF THIS FRONT OVR THE N MTNS...WHILE AIR MASS
ACTUALLY BECOMES MILD ENOUGH FOR EITHER -SHRA OR -SHSN OVER SOUTH.
CONSALL AND OPER EC BOTH SUPPORT MILD TEMPS SAT NIGHT ACROSS
SOUTHERN PA...WITH READINGS ONLY FALLING TO ARND 32F.
FOCUS OF THE MED RANGE FCST REMAINS ON SOUTHERN STREAM DISTURBANCE
LIFTING TOWARD PA LATE IN THE WEEKEND. CONFIDENCE CONTINUES TO
INCREASE IN A SIGNIFICANT BOUT OF WINTRY PRECIP FOR MUCH OF
CENTRAL PA SUNDAY INTO MONDAY...AS PLUME OF GULF OF MEX MOISTURE
OVERRUNS A QUASI-STATIONARY BNDRY JUST S OF THE MASON DIXON. BOTH
GEFS AND OPER EC/CMC SUGGEST THERE WILL BE A NARROW SWATH OF
GREATER THAN AN INCH PRECIP ACROSS CENTRAL OR SOUTHERN PA. BEST
CHC FOR SIGNIFICANT SNOW STILL APPEARS TO BE ACROSS CENTRAL/NORTHERN
PA...WITH A GREATER CHC OF A WINTRY MIX OR RAIN IN THE SOUTH.
BULK OF MED RANGE GUIDANCE INDICATES FAIR AND COLD WX TUE/WED...AS
LG SFC HIGH PRES SYSTEM BUILDS SE TOWARDS PA FROM CENTRAL CANADA.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
27/06Z...VFR CONDITIONS EXPECTED THRU 12Z. ARCTIC FROPA WILL BLAST
THRU THE AIRSPACE BTWN 13-21Z ACCOMPANIED BY SNOW SHOWERS AND
LCL/BRIEF +SHSN/SNSQ. REDUCTIONS TO VIS /IFR CATG OR LOWER/ ARE
LKLY OVR THE WRN/CNTRL TAF SITES WITH THE LOWER VISBYS PERSISTING
THE LONGEST AT JST/BFD INTO THE AFTN. STRONG GUSTY WND SHFT FROM
WSW TO WNW WILL ALSO OCCUR WITH PEAK GUSTS AROUND 30KTS...WHICH
COULD CONTRIBUTE TO LOWER VIS IN AREAS OF BLSN. KEPT VIS AT MVFR
INTO THE MDT/LNS VCNTY BUT GIVEN SHARPNESS/INSTABILITY ALONG THE
REINFORCING ARCTIC FRONT..CANT RULE OUT A BRIEF IFR RESTRICTION
HERE. DOWNSLOPE FLOW IN THE WAKE OF THE FRONT SHOULD BRING ALL
SITES E OF THE MTS BACK TO VFR WHILE MVFR CIGS/OCNL -SHSN LINGER
ACRS WRN SXNS. SFC HIGH PRES BUILDS INTO THE REGION TNGT ALLOWING
WINDS TO SUBSIDE INTO FRI MORNING.
OUTLOOK...
FRI...VFR.
SAT...VFR TRENDING LOWER INTO SAT NGT IN -SN.
SUN-MON...MVFR/IFR LKLY IN SN AND/OR MIXED PCPN.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 3 PM THIS AFTERNOON TO 10 AM EST
FRIDAY FOR PAZ004>006-010>012-017-018-024-033-037-041-042.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
624 AM EST THU FEB 27 2014
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH FRIDAY...BEFORE AN
UPPER LEVEL DISTURBANCE CROSSES THE FROM THE WEST ON SATURDAY. ANOTHER
WARMING AREA OF HIGH PRESSURE WILL BUILD INTO THE AREA LATE SATURDAY
AND LINGER UNTIL A COLD FRONT APPROACHES ON MONDAY AND BRINGS
WIDESPREAD PRECIPITATION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM EST...SFC FRONT HAS PUSHED WELL SOUTH OF THE CWFA
BRINGING DEWPOINTS INTO THE LOWER 20S AND TEENS AT MOST OBS SITES.
VALUES HAVE BEEN STEADY OVER THE PAST COUPLE HOURS BUT SHOULD DROP
ONCE AGAIN AFTER DAYBREAK WITH MIXING GETTING UNDERWAY.
PATCHY LOW STRATUS ARE PRESENT OVER THE ERN UPSTATE AND THE SE SIDE
OF THE CHARLOTTE METRO...BUT ARE BEING FORCED SOUTH/EAST BY THE
DRYING COMING FROM THE NORTH AND THE LIGHT SWLY LLVL FLOW. THESE
HAVE BEEN REASONABLY WELL HANDLED BY THE HRRR OVERNIGHT...AND THIS
MODEL INDICATES THEY WILL DIMINISH RAPIDLY AFTER SUNRISE.
WATER VAPOR IMAGERY SHOWS BROAD TROUGH HAS DIPPED THRU THE AREA WITH
VERY DRY MID-UPPER LEVELS. THIS WILL RESULT IN CLEAR SKIES LASTING
THRU THE DAY. AS THIS WILL COMBINE WITH SOME DEGREE OF
DOWNSLOPING...HAVE LEANED TEMPS IN FAVOR OF BIAS CORRECTED MOS BOTH
TODAY AND TONIGHT.
06Z MODELS FAVOR SLIGHTLY LIGHTER WINDS TODAY WHICH LEADS THEM TO
ALSO FAVOR SLIGHTLY WARMER TEMPERATURES...BUT I THINK CURRENT VALUES
LOOK GOOD BEING ON THE WARM END ALREADY. THE IMPACT ON THE FIRE WX
FCST WOULD BE MINIMAL ANYWAY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 200 AM EST THURSDAY...SFC HIGH PRESSURE WILL BUILD ACROSS THE
DELMARVA REGION DURING THE DAY ON FRIDAY...WITH A PRONOUNCED WEDGE
RIDGE EXTENDED SOUTHWEST ALONG THE EAST SLOPES OF THE BLUE RIDGE. AS
THE AIRMASS WILL BE VERY DRY OVER THE REGION...NO CLOUD COVER IS
EXPECTED TO ACCOMPANY THE COLD AIR DAMMING DURING THE DAY ON
FRIDAY...THOUGH THERE WILL BE SOME INCREASING HIGH CLOUDS LATE IN
THE DAY ASSOCIATED WITH AN APPROACHING SHORT WAVE. EVEN WITH SUNNY
SKIES...HIGH TEMPERATURES SHOULD RUN AROUND 10 DEGREES BELOW NORMAL.
A COMPACT...STRONGLY ADVECTIVE SHORT WAVE WILL CROSS THE REGION
FRIDAY NIGHT AND EARLY SATURDAY. THE MID LEVEL ASCENT AND FORCING
WITH THE WAVE IS IMPRESSIVE...THOUGH THE BAND OF FORCING IS RATHER
NARROW. THE DRY LLVLS WILL TAKE A WHILE TO SATURATE. HOWEVER...
STRONG LLVL UPGLIDE WILL DEVELOP OVERNIGHT OVER THE NE PIEDMONT OF
SC AND THE WRN PIEDMONT OF NC. THIS WILL HELP TO SATURATE THE LLVLS
AND WILL LIKELY CONTRIBUTE TO HIGHER PCPN AMOUNTS IN THIS AREA. EVEN
SO...THE SREF MEAN FOR THE PIEDMONT ZONES IS AROUND A TENTH OF AN
INCH OF LIQUID. THE NC MTNS SHOULD ALSO SEE MORE PCPN FOR THE SIMPLE
FACT THAT THEY ARE HIGHER AND THERE WON/T BE AS MUCH DRY LLVL AIR TO
OVERCOME.
THE PCPN SHOULD FALL AS LIGHT SNOW INITIALLY OVER THE NC MTNS AND
NORTH OF I-40...TRANSITIONING TO A PERIOD OF FREEZING RAIN BEFORE
ENDING AROUND SUNRISE. MUCH LIKE THE PREVIOUS SHIFT...MY SNOW
AMOUNTS ARE BELOW ADVISORY CRITERIA OVER THE NC MTNS AND WRN
FOOTHILLS. FREEZING RAIN ACCUMULATIONS REMAIN QUITE
LIGHT...GENERALLY A COUPLE HUNDREDTHS OF AN INCH ACROSS THE CENTRAL
NC MTNS AND THE NC FOOTHILLS AND THE PIEDMONT ZONES NORTH OF
CHARLOTTE. AS THE PCPN AMOUNTS ARE LOOKING A LITTLE HEAVIER OVER THE
ERN ZONES...IT IS POSSIBLE THAT A FREEZING RAIN OR WINTER WX
ADVISORY MAY BE NEEDED FRI NIGHT FOR ICY SPOTS PRIMARILY ON ELEVATED
SFCS. SINCE MY CONFIDENCE OF AN ADVISORY IS IN THE 30 PERCENT
RANGE...I/LL ADD A MENTION OF THIS TO THE HWO.
FINALLY...WITH HIGH PRESSURE OVERHEAD SATURDAY NIGHT AND A MOIST
BOUNDARY LAYER...BUFKIT SOUNDINGS STRONGLY IMPLY THAT FOG WILL
DEVELOP ACROSS MUCH OF THE REGION.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 2 AM EST THURSDAY...THE MEDIUM RANGE FCST PICKS UP AT 12Z ON
SUNDAY WITH UPPER RIDGING OVER THE GULF OF MEXICO AND SE CONUS AND A
SOUTHERN STREAM UPPER TROF OVER THE SW CONUS. AS WE MOVE INTO
MONDAY...HEIGHTS BEGIN TO LOWER AGAIN AS THE UPPER TROF APPROACHES
THE FCST AREA AND EVENTUALLY PHASES BACK WITH THE NORTHERN STREAM BY
LATE MONDAY. THE MODELS INDICATE THAT SOME DEGREE OF UPPER TROFINESS
WILL MAINTAIN ITSELF OVER THE REGION THRU TUES AND INTO WED WITH THE
LATEST 00Z RUN OF THE GFS BEING SLOWER TO LIFT THE TROF ON WED AND
MAINTAINING A MORE AMPLIFIED SYSTEM COMPARED TO THE ECMWF. THE NEXT
FEATURE OF INTEREST APPEARS TO BE ANOTHER SOUTHERN STREAM H5
SHORTWAVE THAT APPROACHES THE CWFA BY THE END OF THE MEDIUM RANGE
NEXT THURS.
AT THE SFC...THE MODELS APPEAR TO BE COMING INTO BETTER AGREEMENT
WITH REGARDS TO THE EVOLUTION OF THE SYNOPTIC PATTERN ESPECIALLY FOR
THE LATTER HALF OF THE MEDIUM RANGE. WEAK BERMUDA HIGH PRESSURE WILL
BE CENTERED TO OUR EAST ON SUN WITH WEAK AND WARMING SLY LOW LVL
FLOW. BY EARLY MON...THE MODELS SPIN UP A LOW OVER THE SOUTHERN MISS
RIVER VALLEY AND MOVE IT OVER THE CWFA BY MON AFTERNOON AND THEN
WELL OFFSHORE BY EARLY TUES. IN THE LOWS WAKE...DRIER CANADIAN HIGH
PRESSURE SPREADS OVER THE REGION ON TUES AND REMAINS IN PLACE THRU
WED. TEMPS WILL START OUT WELL ABOVE NORMAL ON SUNDAY WITH HIGHS IN
THE UPPER 60S FOR THE LOWER ELEVATIONS AND UPPER 50S TO MID 60S FOR
THE HIGHER TERRAIN. BY WED...I ANTICIPATE VALUES WILL COOL BACK DOWN
BELOW CLIMATOLOGY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AT KCLT...LOW VFR STRATUS ARE EXPECTED TO QUICKLY DISSIPATE ONCE THE
SUN FALLS ON THE CLOUDS AND MIXING GETS GOING...WITH ALL TRACE OF
THEM GONE BY 15Z. MAIN CONCERN OTHERWISE IS WINDS...ALSO BEING
AFFECTED BY THE LEE TROF TODAY. WINDS STARTING OUT NE EARLY THIS
MRNG WOULD THEN FAVOR NW QUADRANT AFTER DIURNAL MIXING BEGINS...BUT
THE TROF IS LIKELY TO KEEP THEM BACKED TO WNW...POSSIBLY GOING WSW
AT TIMES AROUND MIDDAY. THEY SHOULD VEER TO NORTHERLY AGAIN TONIGHT.
ELSEWHERE...SKC EXCEPT FOR STRATUS OVER THE LOWER PIEDMONT WHICH
WILL DISSIPATE BY MID MORNING. WINDS WILL PREVAIL N TO NW THIS MRNG
BUT STAND TO BE AFFECTED BY LEE TROF OVER THE PIEDMONT
TODAY...BRINGING THEM SWLY FOR A TIME. FREQUENT GUSTS OF 25-30 KT
LIKELY AT HIGH MTN ELEVATIONS. SOME GUSTING LIKELY AT KAVL/KHKY
ALSO...THOUGH REMAINING MORE MODERATE AND LESS FREQUENT. GUSTS WOULD
FAVOR NWLY AT ALL SITES. LIGHTER NORTHERLY WINDS WILL RETURN THIS
EVENING.
OUTLOOK...VFR THRU FRIDAY. PRECIPITATION AND SOME RESTRICTIONS ARE
POSSIBLE BEGINNING LATE FRIDAY NIGHT...WITH A LIGHT WINTRY MIX
RESULTING MAINLY OVER WRN NC SATURDAY. VFR CONDITIONS SHOULD RETURN
SUNDAY...BUT A FRONTAL SYSTEM WILL LIKELY BRING WIDESPREAD SHOWERS
AND SOME RESTRICTIONS MONDAY.
CONFIDENCE TABLE...
11-17Z 17-23Z 23-05Z 05-11Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.FIRE WEATHER...
FIRE DANGER STATEMENT WILL REMAIN IN EFFECT TODAY WITH RH VALUES
DIPPING WELL INTO THE TEENS AND MODERATE WINDS THROUGHOUT THE AREA.
WINDS ARE PARTICULARLY CONCERNING ONLY IN THE NRN MTNS...WHERE 850MB
FLOW IS A BIT STRONGER. RIDGETOPS MIGHT SEE SUSTAINED SPEEDS 30-35
MPH...WITH GUSTS TO THAT RANGE EVEN IN LOWER ELEVATIONS. SOME
GUSTING LIKELY THROUGHOUT THE MTNS/FOOTHILLS...UP TO AROUND 20 MPH.
COORDINATION WITH FIRE AGENCIES BY DAY SHIFT TODAY MAY RESULT IN RED
FLAG WARNING BEING ISSUED...ESPECIALLY ALONG THE BLUE RIDGE NORTH OF
THE FRENCH BROAD VALLEY.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...WIMBERLEY
SHORT TERM...MCAVOY
LONG TERM...JPT
AVIATION...WIMBERLEY
FIRE WEATHER...WIMBERLEY
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
1024 AM PST Thu Feb 27 2014
.Synopsis...
Wet weather continues into the weekend. Accumulating mountain
snow will contribute to trans-Sierra travel difficulties today
and also with the next storm wave Friday into Saturday. Isolated
to scattered thunderstorms remain a possibility this morning and
into the early afternoon, then again on Friday. Drivers should be
cautious due to slick roads from snow and rain.
&&
.Discussion...
The shortwave which moved through overnight is splitting, with
energy heading into Oregon and into Nevada. Eastern Pacific
ridging will build in behind, bringing a more stable atmosphere
with warmer air aloft. Some convection is still possible for the
next several hours, though. The HRRR and WRF models are still
showing some CAPE around 100-200 j/kg on the eastern side of the
Sacramento Valley, and into the lower foothills until around 2 pm.
There could be some heavier showers and can`t rule out some isolated
thunderstorms developing in that area before precipitation winds
down in the late afternoon.
Main concern otherwise is snow showers in the mountains through
the rest of the afternoon. A Winter Weather Advisory remains in
effect until 4 pm for the mountains of western Plumas
County/Lassen Park and the northern Sierra above 6000 feet. Snow
amounts so far range from around 4 to 9 inches across interstate
80 from Kingvale eastward to Donner Pass, with chain restrictions
currently still in place. Ski resorts have seen greater amounts,
from around 9 inches up to 19 inches of new snow reported over
some higher peaks. Some additional accumulation of around 1 to 2
inches are possible before the storm ends in the early evening.
After a brief lull tonight, the next storm takes aim at Northern
California. Precipitation amounts at this point look roughly
similar to what we saw with this last storm, although the more
southward track could bring lesser amounts to northern locations
such as in Shasta County mountains. 24 Hour totals (till 4 am)
with this last storm there were around .75 to over 2.50 inches,
and may be about half as much for Friday into early Saturday. The
central and southern Sacramento Valley ranged from low amounts
around Stockton (around .15 inches) to more than an inch, and
Downtown Sacramento had .41 inches as of 4 am. These southerly
Valley spots could see up to an inch or more. Afternoon
thunderstorms are also a concern on Friday. In terms of snow,
motorists should be prepared for wintry driving conditions
returning by early Friday morning. EK
&&
.Extended Discussion (Monday through Thursday)
Nearly zonal flow with weak embedded waves over interior northern
CA Sunday into Monday with a chance for some light showers mainly
over the northern half of the forecast area. A reinforcing wave
impacts northern CA Wednesday and Thursday with a chance of
showers and snow levels around 6000 ft. Expect some breezy
southerly winds ahead of this wave, especially over the Sierra.
JClapp
&&
.Aviation...
Upr trof movg thru this mrng. Flow alf vrs to NWly tda as wk upr
rdg movs thru then backs to SWly ovngt as nxt Pac stm movs thru
Fri into Sat. For Cntrl Vly, mnly VFR tda/tngt exc isold MVFR poss
in shwrs or br. Omtns, areas MVFR/IFR with isold LIFR tda with
impvg conds tngt. Sn lvls 055-065. Conds dtrtg acrs Intr NorCal
aft 10-12z Fri. Lcl Sly sfc wnd gsts up to 30 kts poss in Cntrl
Vly tda and SW-S sfc wnd gsts up to 40 kts ovr hyr mtn trrn.
&&
.STO Watches/Warnings/Advisories...
winter weather advisory until 4 pm pst this afternoon above 6000
feet in the west slope northern sierra nevada...western plumas
county/lassen park.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1004 AM MST THU FEB 27 2014
.UPDATE...
&&
.SHORT TERM...PRECIPITATION SLOW TO DEVELOP AND/OR SPREAD INTO
THE MOUNTAINS...WEB CAMS INDICATING MID LEVEL CLOUDS BEGINNING TO
SPREAD OVER THE AREA. THERE MAY BE SOME LIGHT SNOW OR FLURRIES
OVER THE HIGHER PEAKS. LATEST MODELS...INCLUDING THE RAP AND HRRR
ARE SLOW IN GENERATING THE PRECIPITATION ACROSS THE
MOUNTAINS...UNTIL ABOUT 20Z. SOME PRECIPITATION CURRENTLY ACROSS
THE WEST SLOPE SHOULD BE HEADING INTO THE MOUNTAINS IN THE NEXT
FEW HOURS. WILL DELAY THE HIGHER MOUNTAIN POPS TILL 20Z. REST OF
FORECASTS SEEM ON TRACK AS MOISTURE AND INSTABILITY INCREASE
THROUGH THE AFTERNOON WITH APPROACHING SYSTEM. WILL MAINTAIN THE
ISOLATED THUNDER DUE TO THE INSTABILITY. AND THERE ARE CURRENTLY
SOME STRIKES ACROSS NEVADA INDICATING A FAIRLY UNSTABLE SYSTEM.
CURRENT MOUNTAIN ADVISORY STILL ON TRACK FOR TONIGHT WITH BEST
DYNAMICS...INSTABILITY AND OROGRAPHICS. MODELS STILL SHOW ABOUT 4
TO 8 INCHES THROUGH 5AM FRIDAY. SOME LOCATIONS ALONG WEST FACING
SLOPES COULD RECEIVE HIGHER AMOUNTS. ALSO THE POTENTIAL FOR
BLOWING SNOW WITH GUSTS ABOVE TIMBERLINE INCREASING TO AROUND 60
MPH TONIGHT. DRY CONDITIONS FOR THE PLAINS THROUGH THIS
AFTERNOON...THEN PERHAPS A SLIGHT CHANCE OF RAIN OR SNOW THIS
EVENING WITH INCREASING MID LEVEL ASCENT AND INSTABILITY.
.AVIATION...LATEST MODELS NOW INDICATING WINDS TO WEAKEN BY 19Z AND
BECOME MORE SOUTHEAST AT KDEN AND KAPA AND WEST TO NORTHWEST AT
KBJC WITH THE DEVELOPMENT OF A WEAK CYCLONE NORTH OF DIA. AT THIS
TIME THERE ARE NO SIGNS OF THE CYCLONE DEVELOPING. FOR NOW WILL
CONTINUE THE TREND OF THE CURRENT TAFS WITH A WEST SOUTHWEST
DIRECTION THROUGH TONIGHT. STILL SOME CHANCE OF CEILINGS AROUND
7000 FEET AGL BETWEEN 23Z AND 03Z. NO PRECIPITATION EXPECTED DUE
TO DRIER DOWNSLOPE COMPONENT...THOUGH A FEW RAIN OR SNOW SHOWERS
COULD DEVELOP ALONG THE PALMER DIVIDE SOUTH OF KAPA. ENHANCED
DRAINAGE OVERNIGHT WITH MORE WESTERLY COMPONENT AT KBJC WITH
POSSIBLE GUSTS TO 30 KTS.
&&
.PREV DISCUSSION... /ISSUED 241 AM MST THU FEB 27 2014/
SHORT TERM...THE RIDGE AXIS TO THE WEST OF COLORADO THIS MORNING
WILL FLATTEN OUT AS IT SHIFTS EASTWARD....FOLLOWED BY A WEAK UPPER
LEVEL TROUGH MOVING ACROSS NORTHERN COLORADO TONIGHT. NOT MUCH IN
THE WAY OF SNOWFALL FOR THE MOUNTAINS THIS MORNING...THEN COVERAGE
WILL INCREASE WEST OF THE CONTINENTAL DIVIDE...ESPECIALLY AFTER
21Z. FCST SOUNDINGS SHOW FAIRLY DECENT INSTBY THIS AFTN SO WENT
AHEAD AN ADDED ISOLATED THUNDER IN THE MOUNTAINS AS WELL. THE
URBAN CORRIDOR AND NORTHEAST PLAINS WILL BE QUITE MILD TODAY WITH
HIGHS IN THE 50S. A SURFACE TROUGH WILL BE OVER ERN CO WITH THE
PRESSURE GRADIENT INCREASING ALONG THE FOOTHILLS...WHICH WILL
ENHANCE THE DOWNSLOPE ALONG THE URBAN CORRIDOR AND HELP TO WARM THINGS
UP. MID AND UPPER LEVEL QG ASCENT IS RELATIVELY WEAK WITH THIS
SYSTEM AS IT PASSES ACROSS COLORADO LATE THIS AFTN AND TONIGHT.
THE MDLS TO PAINT SOME QPF ACROSS NERN CO THIS AFTN AND
TONIGHT...MAINLY NORTH AND EAST OF DENVER SO SLGT CHC POPS THERE.
NOT SURE IF DOWNSLOPE OR INSTBY WILL WIN OUT ALONG THE URBAN
CORRIDOR BUT SIDED WITH THE DRY SOLUTION AND NO POPS FOR NOW. IN
THE MOUNTAINS...SPATIAL CROSS-SECTIONS SHOW DEEP MOISTURE AND GOOD
OROGRAPHIC WIND COMPONENT AT 700 MB...25-35KTS. ENOUGH POTENTIAL
FOR SNOW AND WIND TO GO WITH A WINTER WEATHER ADVISORY FOR SNOW
AND BLOWING SNOW FOR ZONES 31..33 AND 34 TONIGHT. SNOW AMOUNTS
GENERALLY 4 TO 6 INCHES BUT SOME AREAS COULD GET 8-10 INCHES.
DOWNSLOPE WINDS DEVELOP AND MID LEVEL SUBSIDENCE INCREASING
FOLLOWING THE PASSAGE OF THE TROUGH AXIS. NO WIND HIGHLIGHTS BUT
WILL ADD AREAS OF BLOWING SNOW WITH GUSTS OF 50-60 MPH ABOVE
TIMBERLINE AND EXPOSED EASTERN SLOPE.
LONG TERM...FRIDAY THROUGH WEDNESDAY...NORTHWEST FLOW ALOFT WILL BE
OVER COLORADO FRIDAY AS A TROUGH MOVES EAST OF THE REGION. COULD BE
SOME LINGERING LIGHT SNOW EARLY FRIDAY OVER THE MOUNTAINS AND FAR
NORTHEAST CORNER. WILL HAVE LOW POPS IN THE FORECAST FOR THIS.
ANOTHER COLD FRONT WILL BACK INTO NORTHEAST COLORADO DURING THE DAY
FRIDAY. IT WILL BE MILD PRIOR TO THE FRONT AND EXPECT HIGHS TO CLIMB
IN TO THE LOWER 50S BEFORE THE FRONTAL PASSAGE.
LARGE PACIFIC LOW WILL MOVE ONTO THE WEST COAST LATE FRIDAY NIGHT. A
MOIST SOUTHWEST FLOW ALOFT WILL TRANSPORT MOISTURE TO COLORADO. WILL
BE ENOUGH MOISTURE TO PRODUCE LIGHT SNOW. HOWEVER...WIND DIRECTION
WILL BE SOUTH-SOUTHWEST...PARALLEL TO THE MOUNTAINS. THIS IS NOT
FAVORABLE FOR OROGRAPHIC LIFT. ALSO THE LACK OF ANY LARGE SCALE
FORCING SHOULD KEEP SNOW LIGHT FRIDAY NIGHT. FOR THE NORTHEAST
PLAINS...AS THE COLD AIR SEEPS INTO THE AREA...MAY SEE LIGHT SNOW OR
FREEZING DRIZZLE LATE FRIDAY NIGHT.
SATURDAY AND SATURDAY NIGHT...LIFT FROM THE TROUGH...JET STREAM AND
INCREASING INSTABILITY WILL CAUSE SNOW TO INCREASE THROUGH THE DAY
AND INTO THE EVENING OVER THE MOUNTAINS. SOME OF THE SNOW COULD
SPREAD ONTO THE PLAINS...ESPECIALLY NORTH. AREAS OF HEAVY MOUNTAIN
SNOW WILL BE POSSIBLE SATURDAY AFTERNOON AND EVENING. THIS WHEN THE
BEST INSTABILITY WILL OCCUR.
TRICKY FORECAST FOR THE FRONT RANGE SATURDAY AND SATURDAY NIGHT...AS
THE COLD AIR DEEPENS...CAN`T RULE OUT A LAYER OF SATURATED AIR NEAR
THE SURFACE THAT COULD PRODUCE FREEZING DRIZZLE. DEPENDING ON HOW
MUCH MOISTURE AND PACIFIC AIR MAKES IT OVER THE MOUNTAINS...SNOW OR
EVEN FREEZING RAIN WILL BE POSSIBLE OVER PARTS OF NORTHEAST
COLORADO. PRECIPITATION TYPE WILL ALSO DEPEND ON SURFACE
TEMPERATURES. FEELING THE MODELS DO NOT HAVE A GOOD HANDLE ON THE
WHERE THE COLD AIR WILL END UP. CLOCKWISE FLOW AROUND A STRONG
SURFACE HIGH OVER THE NORTHERN PLAINS IS EXPECTED TO PRODUCE A
DENVER CYCLONE SATURDAY. DOWNSLOPE SOUTHERLY FLOW OFF THE PALMER
DIVIDER MAY KEEP TEMPERATURES ABOVE FREEZING...WHILE NORTHERLY AND
EASTERLY FLOW DENVER ON NORTH SHOULD PULL IN THE ARCTIC AIR. WILL
HAVE HIGHS FROM AROUND 10 DEGREES OVER THE NORTHEAST CORNER TO MID
40S ALONG THE PALMER DIVIDE. IF ANY MIXED OR FREEZING PRECIPITATION
OCCURS...IT WILL ALL CHANGE TO SNOW BY SATURDAY NIGHT.
ON SUNDAY...SNOW WILL BE ON THE DECREASE SUNDAY AS THE STORM SYSTEM
MOVES EAST OF THE REGION. STRONG ARCTIC HIGH WILL REMAIN EAST OF
COLORADO. THIS WILL KEEP LOW LEVEL FLOW EASTERLY AND PREVENT MUCH
WARMING. LOWERED HIGHS INTO THE TEENS OVER THE FAR NORTHEAST TO MID
30S NEAR THE SOUTHERN FOOTHILLS FOR SUNDAY.
FOR NEXT WEEK...A QUIET WEST TO NORTHWEST FLOW ALOFT WILL PREVAIL.
MODELS SHOWING ENOUGH MOISTURE EMBEDDED IN THE FLOW ALOFT TO KEEP
LOW POPS OVER THE MOUNTAINS. THERE IS A WEAK WAVE PASSING OVER THE
ROCKIES AROUND TUESDAY. NUDGED POPS UPWARDS FOR THIS. EXPECT THE
FRONT RANGE AND EASTERN PLAINS TO REMAIN DRY UNDER THIS PATTERN.
TEMPERATURES WILL BE TRICKY MONDAY AS THE ARCTIC AIR RETREATS.
EVENTUALLY THE COLD AIR WILL BE PUSH OUT OF THE STATE AND
TEMPERATURES WILL BE NEAR NORMAL COME TUESDAY AND WEDNESDAY.
AVIATION...VFR CIGS/VSBYS OVER THE NEXT 24 HOURS. COULD SEE OCNL
BKN CIGS 6-8KFT AGL DEVELOPING 23Z-03Z THIS EVENING...THEN THE
MID LEVEL CLOUDS SHOULD SCT OUT. WSWLY SFC WINDS FOR MUCH OF THE
PERIOD. WINDS MAY SHIFT WEST-NORTHWEST THIS EVENING IS SFC LOW
SHIFTS MORE SOUTH AND EAST. FOR NOW WL STICK WITH WSWLY WINDS
OVER THE NEXT 24 HOURS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 5 AM MST
FRIDAY FOR COZ031-033-034.
&&
$$
SHORT TERM...D-L
LONG TERM....MEIER
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1253 PM EST THU FEB 27 2014
.SYNOPSIS...
A COLD FRONT OVER THE EASTERN GREAT LAKES WILL MOVE THROUGH THE
REGION TODAY. AN ARCTIC HIGH PRESSURE SYSTEM WILL BUILD INTO THE
REGION ON FRIDAY AND THEN LIFT NORTHEAST ON SATURDAY. ANOTHER COLD
FRONT WILL MOVE THROUGH THE FORECAST AREA EARLY SUNDAY BEFORE
STALLING TO OUR SOUTH LATER ON SUNDAY. AN ARCTIC HIGH PRESSURE RIDGE
IS FORECAST TO BUILD OVER NEARBY CANADA AS WAVES OF LOW PRESSURE
FORM AND RIDE ALONG THE STALLED FRONTAL BOUNDARY LATER SUNDAY INTO
MONDAY NIGHT. THE ARCTIC HIGH PRESSURE SYSTEM ITSELF WILL THEN
BUILD SOUTHEAST INTO THE NORTHERN PLAINS ON TUESDAY AND THE GREAT
LAKES ON WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A QUICK UPDATE TO ACCOUNT FOR FLURRIES MOVING ACROSS SOUTHERN NJ.
GIVEN DEW POINT DEPRESSIONS OF 15 TO 20 DEGREES, DO NOT EXPECT ANY
ACCUMULATIONS, BUT THE SNOW SHOWERS COULD CONTINUE THROUGH MID DAY.
NO MAJOR CHANGES TO THE NEAR TERM GRIDS WITH THE 830 UPDATE.
EARLIER CLOUD COVER ACROSS DELMARVA AND SOUTHERN NJ IS BEGINNING
TO SCATTER OUT. THE COLD FRONT IS JUST MOVING INTO NORTHWEST PA
NOW. AT IT`S CURRENT SPEED, IT WOULD REACH SE PA BY 4 PM, BUT THIS
IS BASED ON LIMITED SAMPLING, AND IT SHOULD BE SPEEDING UP
THROUGH THE DAY, SO HAVE STAYED CLOSE TO THE PREVIOUS FORECAST FOR
NOW.
PREVIOUS DISCUSSION...ANOTHER COLD FRONT WILL CROSS THE REGION
TODAY AS AN AREA OF LOW PRESSURE MOVES OUT OF THE GREAT LAKES
REGION AND ACROSS THE NORTHEAST AND COULD BRING SCATTERED SNOW
SHOWERS/FLURRIES TO THE AREA. A POTENT SHORT WAVE/VORT MAX WILL
SWING ACROSS THE NORTHERN PART OF THE AREA AROUND MIDDAY TODAY,
WHILE LOW LEVEL LAPSE RATES INCREASE SIGNIFICANTLY, ESPECIALLY
ACROSS THE NORTHERN HALF OF THE AREA. THE LIMITING FACTOR WILL BE
THE MOISTURE AS LOW LEVEL MOISTURE IS RATHER LACKING EXCEPT ACROSS
THE NORTHERN THIRD OF THE AREA. THE GREATEST POTENTIAL FOR SNOW
SHOWERS WILL BE ACROSS THE NORTHERN THIRD OF THE AREA WHERE THE
GREATEST LIFT/INSTABILITY AND MOISTURE CONVERGE, SO WE WILL HAVE
THE GREATEST POPS HERE. WE DECIDED TO INPUT ISOLATED SNOW
SHOWERS/FLURRIES EVEN AS FAR DOWN AS NORTHERN DELMARVA AND
SOUTHERN NEW JERSEY. ANY SNOW SHOWERS THAT DO DEVELOP AND MAKE
THEIR WAY ACROSS THE AREA COULD PUT DOWN A QUICK COATING TO AN
INCH, ESPECIALLY ACROSS THE HIGHER ELEVATIONS ACROSS OUR WESTERN
AND NORTHERN ZONES. THE BEST TIME PERIOD FOR SHOWERS/FLURRIES TO
OCCUR WOULD BE FROM AROUND NOONTIME THROUGH JUST BEFORE SUNSET.
WINDS TODAY WILL BECOME QUITE GUSTY, ESPECIALLY BEHIND THE COLD
FRONT. WINDS AT THE TOP OF THE MIXING LAYER ARE FORECAST AROUND
40-50 KNOTS, BUT THIS IS AROUND 750-800 MB, SO WE ARE NOT CONFIDENT
WE WILL MIX THIS HIGH. HOWEVER, WINDS WITHIN THE LOWEST 2000-3000
FEET ARE STILL AROUND 35 KNOTS, SO WE COULD STILL SEE WIND GUSTS
35-40 MPH. IT IS POSSIBLE THAT AN OCCASIONAL WIND GUST AROUND 45 MPH
COULD OCCUR FOR AN HOUR OR TWO THIS AFTERNOON, BUT CONFIDENCE IN
OCCURRENCE AND FREQUENCY IS NOT HIGH ENOUGH TO WARRANT AN ADVISORY
AT THIS TIME.
TEMPERATURES WILL REMAIN COLD, ABOUT 15-20 DEGREES BELOW NORMAL, AND
WHEN THE WINDS INCREASE DURING THE DAY, IT WILL FEEL A LOT COLDER. A
BLEND OF MAV/MET MOS, MOSGUIDE, AND ECMWF WAS TAKEN FOR DAYTIME
HIGHS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
ANY SHOWERS/FLURRIES THAT OCCUR DURING THE DAY ARE EXPECTED TO
DIMINISH OR MOVE OUT OF THE AREA AS THE FRONT MOVES OFFSHORE AND THE
SHORT WAVE/VORT MAX PULLS AWAY FROM THE AREA THIS EVENING. WINDS
WILL REMAIN GUSTY FOR THE EVENING BEFORE DROPPING OFF OVERNIGHT.
HOWEVER, THERE SHOULD STILL BE A STEADY BREEZE OVERNIGHT.
TEMPERATURES OVERNIGHT ARE EXPECTED TO BECOME QUITE COLD AND WILL BE
20-25 DEGREES BELOW NORMAL. IN FACT, WE COULD BE APPROACHING RECORD
LOWS FOR SOME CLIMATE SITES OVERNIGHT. WIND CHILLS WILL BE LOW
OVERNIGHT INTO FRIDAY MORNING WITH THE LOW TEMPERATURES AND STRONG
WINDS, REACHING INTO THE SINGLE DIGITS TO MINUS SINGLE DIGITS
EVERYWHERE EXCEPT THE POCONOS WHERE WIND CHILLS COULD REACH -15 TO
-20. THEREFORE WE HAVE ISSUED A WIND CHILL ADVISORY FOR CARBON AND
MONROE, PENNSYLVANIA OVERNIGHT THURSDAY INTO FRIDAY MORNING.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AN IMPACTING WINTER WEATHER EVENT IS STILL EXPECTED TO AFFECT OUR
FORECAST AREA FROM SUNDAY INTO MONDAY WITH A PROBABLE 24 HOUR
CONCENTRATION CENTERED AROUND SUNDAY NIGHT AND MONDAY DAY.
CONFIDENCE ABOUT PTYPE REMAINS LOW, BUT CONFIDENCE ABOUT AN EVENT
AFFECTING OUR AREA REMAINS HIGHER THAN AVERAGE AT THIS TEMPORAL FCST
JUNCTURE. THE TWO STRONGEST CIPS ANALOGS OFF THE 12Z GFS RUN BOTH
HAD MIXED PCPN WINTER STORM CRITERIA EVENTS IN OUR CWA. WHILE
NOTHING IS EVER SET IN STONE THIS FAR OUT IN TIME, IT WOULD BE
PRACTICAL FOR ANYONE INVOLVED WITH WINTER WEATHER MITIGATION TO USE
THE NEXT SEVERAL DAYS TO GET PREPARED.
AS FAR AS THE MODELING IS GOING WITH THIS EVENT, THE OPERATION ECMWF
REMAINS THE WARMEST, ALTHOUGH IT DID TREND SLIGHTLY COLDER FROM THE
DAY RUN AND ITS ENSEMBLE MEAN IS SLIGHTLY COLDER BY MONDAY
EVENING. ITS DIFFERENCE FROM THE OTHER MODELS IS A SLIGHTLY
FARTHER NORTH PV IN EASTERN CANADA (LESS OF A NEARBY SFC RIDGE)
AND HANGING BACK MORE ENERGY IN WESTERN CANADA. BOTH PERMIT A
SLIGHTLY STRONGER TROF TO TRAVERSE THE CONUS AND BRING SLIGHTLY
WARMER AIR INTO OUR CWA. THE GFS ENSEMBLE CLUSTERING HAS ABOUT A
40 PERCENT SUPPORT OF THIS WARMER SOLUTION. THE ECMWF HAS DONE A
PRETTY CONSISTENT JOB OF "LOCKING IN" AT ABOUT 96 HOURS AND INWARD
THIS WINTER. THIS WILL MAKE TODAY`S 12Z RUN ONE TO WATCH TO SEE
THERMALLY WHO BLINKS FIRST.
AS FAR AS THE TIMING AND THE SEQUENCE OF EVENTS THEY ARE GETTING
CLOSER. THIS EVENT IS COMPACTING WHICH IS LOGICAL, ITS RARE FOR PCPN
EVENTS TO LAST LONGER THAN 24 HOURS AND IF SO, THERE IS USUALLY AT
LEAST A 6 TO 12 HOUR BREAK BETWEEN WAVES. THE SECOND LOW IN THE
WAVE TRAIN IS TRENDING WEAKER AND NOT A DURATION STRETCHER. WHILE
THERMALLY THE MODELS ARE DIFFERENT, THE SEQUENCE OF EVENTS ARE
SIMILAR, AS COLDER AIR FILTERS SOUTHWARD, PLACES THAT ARE WARM
ENOUGH ALOFT (BECAUSE OF AN 850MB OR SO WARM INTRUSION) FOR NOT
SNOW WOULD/COULD GO FREEZING RAIN TO SLEET AND THEN SNOW. ALL
LOCALES SHOULD END AS SNOW AND OUR FAR NORTHERN CWA COULD LIKELY
REMAIN ALL SNOW. QPF AMOUNTS ARE TRENDING DOWNWARD, BUT OVER ONE
INCH WATER EQUIVALENTS ARE STILL FORECAST WITHIN OUR CWA (NOT THRUT,
THERE IS A NORTH VS SOUTH DIFFERENCE THAT WE DO NOT HAVE THE SKILL
TO CHOOSE AT THIS POINT). WE ALL CAN DO THE MATH AS TO HOW MUCH
SNOW THAT WOULD BE IF ITS THE ONLY PTYPE.
AS FAR AS THE INITIALIZATION GOES, THE PV IN CENTRAL CANADA IS
SLIGHTLY WEST OF THE MODELING SOLUTIONS. WILL THIS ULTIMATELY LEAD
TO THE EURO SOLUTION BEING CLOSER? AT 850MB AND 925MB THERE WERE NO
BIG DISCREPANCIES NOTED.
AS FOR THE PARTICULARS, WE GET THE IMPRESSION THAT ON FRIDAY MANY
PEOPLE METAPHORICALLY WILL BE TELLING METEOROLOGICAL WINTER TO
NOT HAVE THE DOOR HIT IT ON THE WAY OUT. HIGH TEMPERATURES ARE
GOING TO AVERAGE AN ASTONISHING 25 DEGREES LOWER THAN AVERAGE,
COMPARABLE TO THE DEPARTURES WE SAW ON JANUARY 7TH. IF THERE IS
ANY SAVING GRACE, SUNSHINE SHOULD PREVAIL, THE "NORMALS" ARE
HIGHER AND WINDS SHOULD BE RELATIVELY LIGHT. STAT GUIDANCE LOOKS
TOO LOW BASED ON AFTN FCST 925MB TEMPS. THE ONE WAY THEY MIGHT
WORK IS IF WINDS ARE VERY LIGHT AS THE AIR MASS IS WARMING ITS WAY
DOWNWARD.
THE HIGH PRESSURE SYSTEM MOVES OFFSHORE ON FRIDAY NIGHT AND RETURN
FLOW MOISTURE AT MID AND HIGH LEVELS IS FORECAST TO RETURN. THIS
REDUCES THE CONFIDENCE IN MIN TEMPS AND WE HAVE NOT DIFFERED MUCH
FROM CONTINUITY OR STAT GUIDANCE.
KIND OF A DIRTIER MOISTURE DAY ON SATURDAY ACROSS OUR CWA AS
RELATIVELY WARMER AIR RETURNS. COUPLED WITH SOME SHEARING PVA ITS
THE REASON WE KEPT LOW CHANCE POPS. GIVEN LIGHT PCPN INTENSITY IF
IT OCCURS AT ALL, WE HAVE SOME MENTION OF A LIQUID PTYPE.
THEN ON SATURDAY NIGHT POPS ARE MENTIONED JUST FAR NORTHWEST, IN
CLOSER PROXIMITY TO APPROACHING COLD FRONT. CLOUDINESS IS
EXPECTED TO KEEP MIN TEMPERATURES HIGHER.
THE COLD FRONT STARTS MOVING THROUGH OUR CWA ON SUNDAY. HERE THERE A
RE MODELING DIFFERENCES AS TO HOW QUICKLY WILL PCPN ALONG THE WAVE
ARRIVE. GIVEN THE ANTECEDENT WARM BOUNDARY LAYER TEMPS, WE KEPT PCPN
PRIMARILY AS RAIN FROM THE PHL NORTHWEST SUBURBS AND RARITAN VALLEY
SOUTHEAST AND SNOW NORTHWEST. ECMWF MOS IS 10 TO 15 DEGREES WARMER
THAN GFS MOS WITH MAX TEMPS DUE TO BOTH ITS SLOWER CFP AND FASTER
STALLING. WE USED THE UKMET AS THE ARBITRATOR AND HAVE GONE ABOVE
MEXMOS STAT GUIDANCE FOR HIGHS. PRESENT THINKING IS THAT PCPN
THAT DOES OCCUR DURING THIS PERIOD WOULD BE ON THE LIGHTER SIDE.
THEN THE FORECAST BECOMES COMPLICATED AS COLDER AIR SEEPS IN
SOUTHWARD AS THE WAVES OF LOW PRESSURE MOVE CLOSER TO OUR CWA. THE
PRECIPITATION EVENT SHOULD BE INTENSIFYING AS WE GO THROUGH THE
NIGHT AND INTO MONDAY. POPS ARE PEAKED ON MONDAY WHERE ALL THE
MODELS CONVERGE. HERE WE ARE LEANING TOWARD THE COLDER MODELING
SOLUTIONS. SO ITS BASICALLY ALL SNOW FOR OUR NORTHWEST THIRD, SNOW
AND SOME SLEET IN THE PHILADELPHIA SUBURBS INTO THE RARITAN VALLEY,
A RATHER UGLY TRANSITIONAL MIXTURE OF RAIN, FREEZING RAIN TO SLEET
AND SNOW ALONG AND AROUND THE I95 CORRIDOR AND A LATER TRANSITION
NEAR THE COAST. THIS EVENT SHOULD BE ENDING ON MONDAY NIGHT.
TUESDAY AND WEDNESDAY ARE KEPT DRY WITH TEMPERATURES EXPECTED TO
REMAIN WELL BELOW NORMAL. METEOROLOGICAL WINTER STILL CAN NOT
FIND THAT DOOR.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
SCATTERED SHSN CONTINUE ACROSS THE REGION, RESULTING IN BRIEF MVFR
CONDITIONS. A MORE SIGNIFICANT LINE OF SHSN IS CURRENTLY IN
CENTRAL PA SLIDING EAST. IT SHOULD ENTER OUR AREA AROUND 21Z,
HOWEVER HIGH RES MODELS SUCH AS THE HRRR SHOW THE SOUTHERN END OF
THE LINE ERODING AS IT APPROACHES THE REGION. THUS, ONLY EXPECT
ABE AND RDG TO BE AFFECTED AT THIS TIME, BUT WILL BE WATCHING FOR
POSSIBLE IMPACTS TO TTN, PNE, AND PHL. THIS LINE OF SHSN IS WITH
THE COLD FRONT, SO ALSO EXPECT AN ABRUPT SHIFT TO WESTERLY, THEN
NORTHWESTERLY WINDS THROUGH THE SAME TIME PERIOD. WINDS SHOULD
DIMINISH A FEW HOURS AFTER SUNSET AND STAY LIGHT THROUGH THE
REMAINDER OF THE TAF PERIOD. VFR CONDITIONS ARE ALSO EXPECTED
BEHIND THE FRONT THROUGH THE REMAINDER OF THE TAF PERIOD.
OUTLOOK...
FRIDAY AND FRIDAY NIGHT...VFR CONDITIONS EXPECTED.
SATURDAY...VFR CONDITIONS EXPECTED, POSSIBLY MVFR DURING THE
AFTERNOON NW AIRPORTS AND TERMINALS.
SATURDAY NIGHT...MVFR VSBYS EXPECTED AND MVFR TO IFR CIGS EXPECTED.
SUNDAY INTO MONDAY...A PROTRACTED WINTER WEATHER EVENT IS OUTLOOKED
WITH MVFR TO IFR CONDITIONS EXPECTED TO CONTINUE. WHILE CONFIDENCE
ABOUT PCPN TYPE TIMING IS LOW, MOST OF THE AIRPORTS AND TERMINALS
ARE CURRENTLY OUTLOOKED TO BE AFFECTED BY THIS SYSTEM.
&&
.MARINE...
THE GALE WARNING REMAINS IN PLACE ACROSS THE WATERS AS WINDS WILL BE
INCREASING BEHIND A COLD FRONT THAT WILL CROSS THE AREA THIS
AFTERNOON. THE STRONGEST WINDS ARE EXPECTED LATE THIS AFTERNOON INTO
THIS EVENING AND WIND GUSTS COULD RETURN TO ADVISORY LEVELS
OVERNIGHT INTO FRIDAY MORNING. HOWEVER, WE WILL LEAVE THE ENDING
TIME OF 6 AM FRIDAY FOR THE GALE WARNING AND LET LATER SHIFTS
CONVERT THE GALE WARNING TO SMALL CRAFT ADVISORIES WHEN THE TIME
COMES.
WITH THE COLD TEMPERATURES EXPECTED OVERNIGHT INTO FRIDAY MORNING
COMBINED WITH THE GUSTY WINDS, MODERATE FREEZING SPRAY IS EXPECTED
TO DEVELOP. THEREFORE A FREEZING SPRAY ADVISORY HAS BEEN ISSUED FOR
ALL WATERS OVERNIGHT INTO FRIDAY MORNING.
OUTLOOK...
FRIDAY...WINDS AND SEAS WILL DIMINISH THROUGH THE DAY AND FALL BELOW
SMALL CRAFT ADVISORY CRITERIA. SOME MODERATE FREEZING SPRAY IS
LIKELY TO CONTINUE ON FRIDAY MORNING AND IS COVERED IN THE PRESENT
ADVISORY.
FRIDAY NIGHT THROUGH SUNDAY...WINDS AND SEAS ARE EXPECTED TO REMAIN
BELOW SMALL CRAFT ADVISORY CRITERIA.
SUNDAY NIGHT AND MONDAY...SMALL CRAFT ADVISORY CRITERIA CONDITIONS
ARE FORECAST TO RETURN ALONG WITH A WINTRY MIX OF PRECIPITATION.
&&
.FIRE WEATHER...
RELATIVE HUMIDITY LEVELS WILL DROP INTO THE 20S TO NEAR 30 PERCENT
FOR PORTIONS CENTRAL/SOUTHERN NEW JERSEY, EASTERN PENNSYLVANIA, AND
THE DELMARVA REGION THIS AFTERNOON. ALSO WINDS WILL BE VERY WINDY
TODAY. HOWEVER, WITH THE AMOUNT OF PRECIPITATION OUR AREA HAS HAD
THE LAST COUPLE OF WEEKS, FUEL MOISTURE CONTENT SHOULD BE HIGH
ENOUGH TO NEGATE THE NEED FOR ANY RED FLAG HEADLINES, ESPECIALLY
WHERE ANY SNOW COVER REMAINS.
LATEST OBSERVATIONS SHOW DEW POINT TEMPERATURES A BIT HIGHER THAN
PREVIOUSLY FORECAST. THUS, SHOULD APPROACH BUT NOT QUITE MEET THE
RH CRITERION TODAY.
&&
.TIDES/COASTAL FLOODING...
A LOW WATER ADVISORY HAS BEEN ISSUED FOR MARINE AREA WATERS FOR THE
LOW TIDE CYCLE TONIGHT. A SPS WILL ALSO BE ISSUED FOR THE TIDAL
SECTIONS OF THE DELAWARE RIVER FOR THE SAME LOW TIDE CYCLE. GOOD
MODELING CONSENSUS ABOUT BLOW OUT TIDES OCCURRING TONIGHT. THERE IS
DIVERGENCE WITH THE SUBSEQUENT LOW TIDE CYCLE DURING THE SECOND HALF
OF THE DAY ON FRIDAY. BY THEN THE WINDS ARE FORECAST TO BE
RELATIVELY LIGHT FOR AT LEAST SIX HOURS. WE REALIZE THAT THERE IS A
LAGGING EFFECT DUE TO STRONGER WINDS FARTHER OFFSHORE, BUT
CONFIDENCE IS TOO LOW AT THIS POINT TO GO BEYOND THIS LOW TIDE
CYCLE WITH THE ADVISORY.
&&
.CLIMATE...
RECORD LOW TEMPERATURES FOR THE 27TH AND 28TH. IT DOES NOT APPEAR
THAT THESE RECORDS WILL BE IN JEOPARDY TODAY, BUT A FEW LOCATIONS
HAVE A CHANCE ON THE 28TH.
FEBRUARY 28TH
ATLANTIC CITY...2 DEGREES IN 1934
PHILADELPHIA....9 DEGREES IN 1934
WILMINGTON.....-5 DEGREES IN 1934
ALLENTOWN.....-10 DEGREES IN 1934
TRENTON.........1 DEGREE IN 1934
GEORGETOWN......8 DEGREES IN 1950
READING.........3 DEGREES IN 1934
MOUNT POCONO..-15 DEGREES IN 1907
PHILADELPHIA HAD ITS 12TH CALENDAR DAY OF MEASURABLE SNOW SO FAR
THIS SEASON YESTERDAY. THIS TIES THE MOST CALENDAR DAYS WITH AT
LEAST AN INCH OF SNOW SINCE THE WINTER OF 1977-78. THE NEXT ONE
CHRONOLOGICALLY ON THE LIST IS THE RECORD HOLDING WINTER OF
1917-18 WITH 17 DAYS.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WIND CHILL ADVISORY FROM 11 PM THIS EVENING TO 9 AM EST FRIDAY
FOR PAZ054-055.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...LOW WATER ADVISORY FROM 11 PM THIS EVENING TO 4 AM EST FRIDAY
FOR ANZ450>455.
FREEZING SPRAY ADVISORY FROM 11 PM THIS EVENING TO 9 AM EST
FRIDAY FOR ANZ430-431-450>455.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 6 AM EST FRIDAY FOR
ANZ430-431-450>455.
LOW WATER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM EST FRIDAY
FOR ANZ430-431.
&&
$$
SYNOPSIS...GIGI/MEOLA
NEAR TERM...JOHNSON/ROBERTSON
SHORT TERM...ROBERTSON
LONG TERM...GIGI
AVIATION...GIGI/JOHNSON/MEOLA
MARINE...GIGI/ROBERTSON/MEOLA
FIRE WEATHER...
TIDES/COASTAL FLOODING...
CLIMATE...
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
400 PM EST THU FEB 27 2014
.SYNOPSIS...
20Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN UPPER LEVEL PATTERN
DOMINATED BY RIDGING OVER THE CONTINENTAL DIVIDE...FOLLOWED
DOWNSTREAM BY A LARGE LONGWAVE TROUGH IN CONTROL OF MUCH OF THE
EASTERN HALF OF THE NATION. A POTENT AND VERY COLD LOBE OF ENERGY
WITHIN THIS TROUGH IS PASSING OVER THE GREAT LAKES WITH H5 HEIGHTS
OF 485-490DM AND 850MB TEMPS AS LOW AS -30. THAT IS COLD FOR THIS
LATE IN FEBRUARY...EVEN FOR THE GREAT LAKES REGION. WE WILL SEE JUST
A QUICK GLANCING COOL DOWN FOR THE NEXT DAY BEFORE A QUICK REBOUND
IN TEMPS OCCURS DURING THE UPCOMING WEEKEND. OUR FORECAST AREA
RESIDES AT THE BASE OF THE EASTERN CONUS TROUGH WITHIN A BROAD
CYCLONIC FLOW REGIME. WV IMAGERY SHOWS A PLUME OF MID/UPPER LEVEL
MOISTURE STREAMING ACROSS THE EASTERN GULF AND OVER FLORIDA AHEAD OF
THE TROUGH AXIS. A SERIES OF WEAK IMPULSES CAN BE SEEN WITHIN THE
FLOW CROSSING THE GULF...AND THIS ENERGY WILL COMPLICATE OUR
FORECAST FOR THE EVENING IN TERMS OF JUST WHERE AND WHEN ANOTHER
ROUND OF SHOWERS WILL OCCUR FOR THE CENTRAL AND SOUTHERN ZONES.
AT THE SURFACE...WEAK COLD FRONT IS ANALYZED OVER SOUTH FLORIDA...
SOUTH OF ALL OUR FORECAST ZONES. TEMPERATURES ARE COOLER THAN WE
HAVE EXPERIENCED OVER THE PAST WEEK OR 2 WITH 50S FAR NORTH RANGING
TO THE LOWER 60S CENTRAL...AND UP TO AROUND 70 FAR SOUTH. REGIONAL
RADAR IS BEGINNING TO PICK UP ON AN EXPANDING AREA OF SHOWERS OFF
THE WEST-CENTRAL/SOUTHWEST FLORIDA COAST WHICH IS EXPECTED TO EXPAND
TOWARD THE COAST THE NEXT COUPLE OF HOURS.
&&
.SHORT TERM (TONIGHT THROUGH SUNDAY)...
TONIGHT...
FORECAST DILEMMA FOR THE FIRST HALF OF THE NIGHT IS JUST HOW FAR
NORTH THE INFLUENCE OF THE APPROACHING SHORTWAVE IMPULSES WILL
ALLOW FOR SHOWERS. THE RAP/HRRR GUIDANCE ALONG WITH LOCAL HIRES
GUIDANCE HAS BEEN INSISTENT ALL DAY ON A FINAL BATCH OF RAIN/SHOWERS
ARRIVING LATE AFTERNOON INTO THE EVENING OVER THE SOUTHERN HALF OF
THE AREA. WE SAW THE COOLING COLD TOPS ON SATELLITE OUT OVER THE
CENTRAL GULF THE PAST FEW HOURS...AND NOW FINALLY THIS DEVELOPMENT
IS COMING INTO RANGE OF THE LAND BASED RADARS. LOOKING MORE AND MORE
LIKE THE GUIDANCE MENTIONED ABOVE IS ON THE RIGHT TRACK...AND A
SHOWERY EVENING APPEARS ON TAP FOR THE SOUTHERN HALF OF THE AREA.
THE QUESTION IS WHETHER OR NOT THE TAMPA BAY AREA EASTWARD ALONG THE
I-4 CORRIDOR WILL GET INTO THIS BATCH OF SHOWERS OR IF THE CUT-OFF
WILL BE AROUND MANATEE/HARDEE COUNTIES. WILL KEEP AT LEAST A LOW END
CHANCE FOR SHOWERS INTO PINELLAS/HILLSBOROUGH/NORTHERN POLK FOR THE
EVENING HOURS...WITH HIGHER RAIN CHANCES FURTHER SOUTH. INITIAL
FORECAST WAS FOR HIGH END CHANCE 50% POPS FOR THESE SOUTHERN ZONES
WITH SOME UNCERTAINTY AS TO JUST HOW MUCH SYNOPTIC SUPPORT THE
SHORTWAVES WOULD PROVIDE. NOW THAT THERE INFLUENCE IS BECOMING MORE
CERTAIN...WILL BE RAISING POPS TO LIKELY THIS EVENING SOUTH OF THE
BAY AREA.
BY THE SECOND HALF OF TONIGHT...MOST OF THE SYNOPTIC SUPPORT FOR
LIFT ALONG WITH THE BEST COLUMN MOISTURE DEPARTS TO THE EAST OF THE
FORECAST AREA. WILL SHOW ANY LINGERING SHOWER CHANCES ENDING OVER
THE SOUTHERN ZONES BEFORE DAWN. SURFACE HIGH PRESSURE WILL BE
BUILDING IN FROM THE NORTH WITH A COOL AND DRY AIRMASS BECOMING
STRONGLY ESTABLISHED FROM TAMPA BAY NORTHWARD. A FAVORABLE DRAINAGE
FLOW PATTERN LOOKS TO BRING ENOUGH COLD AIR SOUTHWARD THAT WE ARE
CONCERNED WITH TEMPS LATE NIGHT APPROACHING...OR EVEN DROPPING BELOW
FREEZING FOR A FEW HOURS ACROSS PARTS OF LEVY COUNTY. AS A RESULT
THE FREEZE WATCH HAS BEEN UPGRADE TO A FREEZE WARNING. IN TERMS OF
FROST...THE DEWPOINT DEPRESSION IN THE MOS GUIDANCE IS ALMOST TOO
LARGE (5-7 DEGREES) TO SUPPORT MUCH FROST FORMATION ACROSS LEVY
COUNTY. HOWEVER...NORMALLY THIS DEPRESSION IS LESS RIGHT AT GROUND
LEVEL AND WILL ALLOW FOR FROST DEVELOPMENT IN THE GRIDS TO GO ALONG
WITH THE FREEZE. SLIGHTLY BETTER CONDITIONS FOR AREAS OF FROST MAY
ACTUALLY EXIST SOUTH OF THE FREEZE WARNING ACROSS CITRUS/SUMTER AND
HERNANDO COUNTIES WHERE TEMPS ARE EXPECTED TO ACTUALLY STAY JUST
ABOVE FREEZING...BUT WHERE THE DRY AIR INTRUSION WILL BE LESS.
YES...IT IS POSSIBLE TO HAVE FROST WITH 2-M TEMPS ABOVE FREEZING. A
FROST ADVISORY HAS BEEN ISSUED FOR CITRUS AND HERNANDO COUNTIES FOR
LATE TONIGHT. THE REST OF THE FORECAST AREA WILL SEE LOW TEMPS IN
THE 40S ACROSS CENTRAL FLORIDA AND INTO THE LOWER/MID 50S DOWN
TOWARD CHARLOTTE/LEE COUNTIES.
FRIDAY/FRIDAY NIGHT...
A PLEASANT LATE FEBRUARY DAY IN STORE FOR THE FINAL DAY OF THE WORK
WEEK. EXPECTING PLENTY OF SUNSHINE AND LIGHT WINDS AS COLUMN
MOISTURE CONTINUES TO DECREASE AND SURFACE RIDGING BECOMES FIRMLY
ESTABLISHED FROM THE NORTH. STILL WILL SEE A FEW PASSING IMPULSES
ALOFT...BUT WITH VERY LITTLE LEFT OVER MOISTURE...HAVE NO RAIN
CHANCES IN THE FORECAST. TEMPERATURES WILL WARM AFTER THE COOL START
INTO THE 70S FOR MOST LOCATIONS. ONLY EXCEPTIONS WILL BE OVER THE
FAR NORTHERN ZONES...AND ALONG THE COAST FROM MANATEE COUNTY
NORTHWARD WHERE DEVELOPING AFTERNOON SEA-BREEZES WILL BRING COOLER
AIR OFF THE SHELF WATERS BACK ONSHORE. LOW TEMPS WILL STILL BE COOL
FRIDAY NIGHT...BUT DO NOT HAVE ANY CONCERNS FOR FREEZES OR FROST FOR
ANY OF OUR ZONES. GENERALLY LOOKING FOR LOWER TO MIDDLE 40S NORTH OF
I-4...AND UPPER 40S TO LOWER 50S FURTHER SOUTH.
SATURDAY/SUNDAY...
THE WARMING TREND CONTINUES. HEIGHTS WILL BE RISING THROUGH THE DAY
ON SATURDAY WITH MORE ABUNDANT SUNSHINE. LOCATIONS AWAY FROM THE
COAST FROM I-4 SOUTHWARD WILL BE FLIRTING WITH 80 DEGREES WHILE
FURTHER NORTH 70S WILL BE COMMON. ONCE AGAIN...TEMPERATURES MAY FALL
BACK THROUGH THE 70S DURING THE AFTERNOON ALONG THE IMMEDIATE COAST
WITH WINDS BECOMING LOCALLY ONSHORE. MORE OF THE SAME FOR SUNDAY. A
VERY NICE LOOKING WEEKEND IN TERMS OF SENSIBLE WEATHER IN STORE.
&&
.LONG TERM (MONDAY THROUGH NEXT THURSDAY)...
MEDIUM RANGE GUIDANCE IS IN FAIRLY GOOD AGREEMENT THROUGH THE LONG
TERM PERIOD. HIGH PRESSURE WILL HOLD IN PLACE ACROSS THE AREA
THROUGH MONDAY. A WEAKENING COLD FRONT WILL THEN SHIFT SOUTHWARD
THROUGH THE REGION MONDAY NIGHT WITH HIGH PRESSURE THEN BUILDING
NORTH OF THE STATE TUESDAY THROUGH WEDNESDAY. MODEL SOLUTIONS THEN
BEGIN TO DIVERGE SLIGHTLY WITH RESPECT TO THE TIMING OF THE NEXT
STORM SYSTEM...WHICH COULD POTENTIALLY BE A STRONG ONE...FOR THE END
OF THE UPCOMING WORK WEEK. AS FOR FORECAST DETAILS...WILL SHOW RAIN
CHANCES MONDAY NIGHT AND TUESDAY IN ASSOCIATION WITH THE WEAKENING
COLD FRONT MOVING THROUGH. WILL ALSO INDICATE RAIN CHANCES WEDNESDAY
THROUGH THURSDAY ASSOCIATED WITH THE NEXT STORM SYSTEM THAT WILL
MOVE INTO THE AREA. TEMPERATURES ARE EXPECTED TO RUN NEAR TO
SLIGHTLY ABOVE NORMAL LEVELS THROUGH THE PERIOD.
&&
.AVIATION...
MVFR CIGS ACROSS TERMINALS CONTINUE TO LINGER OVER THE CENTRAL
PENINSULA. DRIER IS SLOWLY FILTERING SOUTH...BUT WILL NOT REACH THE
NORTHERN SITES UNTIL LATE THIS EVENING. ADDITIONALLY...GUIDANCE
CONTINUES TO HINT AT SHOWERS PUSHING INLAND FROM THE GULF BY THIS
EVENING AFFECTING SITES FROM SRQ SOUTHWARD THROUGH AROUND 04Z. WILL
UPDATE WITH PREVAILING/TEMPO -RA OR RA GROUPS AS NEEDED BUT FOR THE
18Z FORECAST WILL ONLY MENTION VCSH. DRIER AIR EXPECTED TO PUSH
THROUGH THE REGION BY TOMORROW MORNING WITH VFR PREVAILING.
&&
.MARINE...
HIGH PRESSURE WILL BUILD OVER THE EASTERN GULF OF MEXICO TONIGHT AND
REMAIN IN PLACE THROUGH THE UPCOMING WEEKEND. WINDS AND SEAS SHOULD
REMAIN BELOW HEADLINE CRITERIA THROUGH THE PERIOD. WINDS WILL SHIFT
ONSHORE NEAR THE COAST EACH OF THE NEXT SEVERAL AFTERNOONS AS LOCAL
SEA-BREEZES DEVELOP. THE NEXT COLD FRONT AND POTENTIAL FOR
CAUTIONARY OR ADVISORY LEVEL WINDS AND SEAS IS NOT EXPECTED TO
ARRIVE UNTIL NEXT TUESDAY OR TUESDAY NIGHT.
&&
.FIRE WEATHER...
PERIODS OF SHOWERS OVER THE CENTRAL AND SOUTHERN ZONES WILL END
OVERNIGHT AS A MUCH DRIER AIRMASS ARRIVES FROM THE NORTH. THIS DRIER
AIRMASS WILL COMBINE WITH MODERATING TEMPERATURES ON FRIDAY TO
PRODUCE WIDESPREAD RELATIVE HUMIDITY VALUES AT OR BELOW CRITICAL
LEVELS FOR THE AFTERNOON HOURS. ALTHOUGH THE RELATIVE HUMIDITY WILL
BE LOW...ERC VALUES AND WINDS WILL BE BELOW CRITICAL THRESHOLDS AND
NO RED FLAG CONDITIONS ARE ANTICIPATED. INLAND AREAS MAY ONCE AGAIN
BRIEFLY APPROACH CRITICAL LEVELS OF RELATIVE HUMIDITY ON SATURDAY
AFTERNOON ONCE AGAIN...BUT LIGHT WINDS AND LOW ERC VALUES SHOULD
PREVENT ANY RED FLAG CONDITIONS. LOCATIONS ALONG AND CLOSE TO THE
COAST SHOULD EXPECT A WIND SHIFT TO THE WEST OR NORTHWEST EACH
AFTERNOON THE NEXT SEVERAL DAYS AS LOCAL SEA BREEZES DEVELOP.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 46 69 52 75 / 30 0 0 0
FMY 55 75 55 80 / 60 10 0 0
GIF 48 72 51 78 / 30 0 0 0
SRQ 48 69 51 74 / 60 0 0 0
BKV 35 71 42 77 / 10 0 0 0
SPG 52 69 55 74 / 30 0 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...FROST ADVISORY FROM 2 AM TO 8 AM EST FRIDAY FOR COASTAL
CITRUS-COASTAL HERNANDO-INLAND CITRUS-INLAND HERNANDO.
FREEZE WARNING FROM 2 AM TO 8 AM EST FRIDAY FOR COASTAL
LEVY-INLAND LEVY.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM...JELSEMA
AVIATION...BARRON
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
217 PM EST THU FEB 27 2014
.SYNOPSIS...
HIGH PRESSURE BUILDS IN TONIGHT SERVING UP A COLD NIGHT. THE NEXT
UPPER LEVEL DISTURBANCE BRINGS SNOW SHOWERS SATURDAY. LOW PRESSURE
RIDING UP THE OHIO VALLEY WILL PRODUCE ACCUMULATING SNOW SUNDAY INTO
MONDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
SNOW SHOWERS...SQUALLS...AND WINDS WILL SLOWLY DECREASE THIS
AFTERNOON AS MID LEVEL ENERGY EXITS E. RADAR SHOULD BE PCPN FREE
BEFORE 0Z. IF YOU BELIEVE THE LATEST HRRR SIMULATED REFLECTIVITY
BETWEEN 22-23Z.
A COLD NIGHT ON TAP FOR THE REGION. WIND CHILL VALUES FALL INTO
ADVISORY RANGE /-10 TO -20F/ BY THIS EVENING. H8 TEMPS DROP TO -24C
BY 12Z FRIDAY WITH HIGH PRESSURE BUILDING IN FROM THE GREAT LAKES.
WITH JUXTAPOSITION OF SFC ANTICYCLONE AND CONTINUED SNOWPACK ACROSS
NORTHERN COUNTIES WOULD NOT BE SURPRISED TO SEE MIN T FALL CLOSE TO
-10 ACROSS JEFFERSON WWRD TO FOREST. RIGHT NOW...SIDED WITH VALUES
AROUND -5F PER WINDS WILL STAY UP MOST OF THE NIGHT AND NOT BECOMING
LIGHT UNTIL AFTER MIDNIGHT.
BL TEMPS UNDERGO STRONG WARM ADVECTION /+10C IN 12HRS/ WHICH ALLOWS
FOR A NICE RECOVERY FROM SUB ZERO MORNING READINGS. WITH H8 TEMPS
AROUND -8C TO -14C COUPLED WITH FULL SUNSHINE WE STILL WON`T MANAGE
TO GET ABOVE 30F ANYWHERE. COMMUNITIES ALONG AND NORTH OF I-80 WILL
REMAIN IN THE TEENS. NOT THE BEST WAY TO CLOSE OUT FEBRUARY...BUT
GIVEN WE WERE -4F BELOW NORMAL FOR THE MONTH...THIS SHOULD NOT BE A
SURPRISE. IT APPEARS WE WON/T MAKE THE TOP 20 COLDEST FEBRUARY/S
AT PITTSBURGH BASED ON AVERAGE MEAN TEMPERATURE.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
BENIGN WEATHER FRIDAY NIGHT HOWEVER MID AND UPPER LEVEL MOISTURE
WILL BE APPROACHING FROM THE WEST AHEAD OF THE NEXT SHORT WAVE
TROUGH. STILL EXPECT A LIGHT QPF EVENT SAT WITH AREA OF HIGHEST
POPS CONFINED ACROSS I-80 WHERE DYNAMICS ARE BETTER FOR INCREASED
SNOW SHOWER COVERAGE. NOT EXPECTING MORE THAN AN INCH OF
ACCUMULATION IN THE AFOREMENTIONED AREA.
BAROCLINIC ZONE STALLS OUT ALONG THE OHIO RIVER E ALONG THE MASON
DIXON LINE AS STEERING FLOW ALOFT ORIENTS PARALLEL TO IT. LOT OF
CLOUDS ARE PREDICTED THROUGH THE WEEKEND AS MOISTURE TRAIN EXISTS IN
THE WSW FLOW ALL THE WAY BACK TO THE SOUTHERN PLAINS. ANY PCPN SUN
MORNING WILL BE FLURRIES OR LIGHT SNOW SHOWERS...HOWEVER AS THE DAY
PROGRESSES MODEST ISENTROPIC UPGLIDE AND POSITIVE PRESSURE ADVECTION
WILL INCREASE AREAL COVERAGE OF SNOW AND INTENSITY. ECMWF SEEMS
HIGH WITH QPF AND SIDED MORE WITH GFS WHICH IS ALIGNED WITH
PREVIOUS FORECAST. ANY ACCUMULATIONS WILL BE LIGHT WITH A FEW
INCHES POSSIBLE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
QUESTIONS REMAIN REGARDING THE MUCH ASKED AND MUCH HYPED WINTER
STORM POISED TO AFFECT THE AREA EARLY NEXT WEEK. DIFFERENCES REMAIN
AMONGST NCEP SUITE WITH SLIGHT WOBBLING WITHIN ENSEMBLE MEANS.
GREATEST CERTAINTY AT THIS POINT IS SNOW NORTH OF I-70 WHERE THERMAL
PROFILES REMAIN COLD ENOUGH. EVEN NORTHERN MOST TRACK KEEPS PTYPE
ALL SNOW. FARTHER SOUTH IT REMAINS IFFY GIVEN PLACEMENT OF SURFACE
CYCLONE. LATEST RUN OF 12Z ECMWF HAS ARRIVED COOLER WITH SOUTHWARD
PLACEMENT OF LOW PRESSURE. IN SITUATIONS LIKE THIS SLIGHT
ADJUSTMENTS ARE PRUDENT TO KEEP FORECAST CONSISTENCY. GIVEN THIS
WINTER MOST WEATHER SYSTEMS HAVE OVER ACHIEVED AND TRENDED COLDER AS
THE EVENT DREW CLOSER...OUR CURRENT PROJECTION OF MOSTLY SNOW LOOKS
GOOD. DID ADD A PERIOD OF SNOW AND SLEET ACROSS THE FAR SOUTHERN
ROW OF COUNTIES SUNDAY NIGHT SINCE WARM LAYER ALOFT TEMPERATURE FROM
BOTH GFS AND ECMWF SUPPORT THIS.
DETERMINISTIC MODELS PULL PRECIP FROM THE FORECAST BY MONDAY
NIGHT...HAVE KEPT IN CHANCE POPS MONDAY NIGHT INTO TUESDAY MORNING
WITH ENSEMBLES INDICATING SNOW MAY HANG AROUND A BIT LONGER.
HIGH PRESSURE WILL MOVE OVER THE WESTERN GREAT LAKES BY TUESDAY...AND
SLOWLY DRIFT TO THE EAST ON WEDNESDAY...ALLOWING FOR DRY
CONDITIONS. A RETURN TO NORMAL TEMPERATURES IS NOT SEEN IN THE
EXTENDED FORECAST...WITH READINGS REMAINING 15 TO 20 DEGREES BELOW
NORMAL.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
SNOW SQUALLS CONTINUE TO IMPACT MOST...IF NOT ALL...OF THE TAF
SITES THIS AFTERNOON AS THE ARCTIC FRONT CROSSES. EXPECT RAPID
FLUCTUATIONS FROM MVFR TO LIFR IN THESE BANDS AND HAVE TRIED TO
HANDLE THESE WITH TEMPO GROUPS THROUGH THE NEXT COUPLE OF HOURS
BASED OFF OF THE RADAR. A GRADUAL IMPROVEMENT SHOULD BE SEEN TO
MVFR AND VFR THROUGH THE LATE AFTERNOON ALTHOUGH CEILINGS MAY HOLD
ON A BIT LONGER WITH SUCH STRONG COLD ADVECTION TAKING PLACE. NONE
OF THE MODELS CARRY MVFR BEYOND 21Z BUT THIS MAY NEED TO BE
ADJUSTED.
IN ADDITION TO THE SNOW...WIND GUSTS WILL CONTINUE TO BE IN THE
30-35KT RANGE THROUGH THIS AFTERNOON WITH THIS FRONTAL
PASSAGE...DECREASING TOWARDS SUNSET TONIGHT AS HIGH PRESSURE
BEGINS TO BUILD TO THE EAST. HIGH PRESSURE SHOULD HELP TO SCATTER
OUT CLOUDS AND RETURN VFR CONDITIONS TO MOST LOCATIONS OVERNIGHT
TONIGHT AND FOR FRIDAY.
.OUTLOOK..../THURSDAY NIGHT THROUGH TUESDAY/...
MULTIPLE DISTURBANCES ARE EXPECTED TO SPAWN WIDESPREAD
RESTRICTIONS SATURDAY THROUGH MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST FRIDAY
FOR MDZ001.
OH...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST FRIDAY
FOR OHZ040-041.
PA...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST FRIDAY
FOR PAZ007>009-013>016-022-023-074-076.
WV...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST FRIDAY
FOR WVZ023-041.
&&
$$
.SYNOPSIS...34
.NEAR TERM...98
.SHORT TERM...98
.LONG TERM...98/33
.AVIATION...34
AREA FORECAST DISCUSSION
NWS BILLINGS MT
315 PM MST THU FEB 27 2014
.SHORT TERM...VALID FOR FRI AND SAT...
INGREDIENTS CONTINUE TO COME TOGETHER FOR A DANGEROUS WINTER
STORM TONIGHT THROUGH SAT NIGHT. AT 21Z...ARCTIC FRONT WAS SURGING
S THROUGH SOUTHERN ALBERTA. MOISTURE MOVING INTO THE AREA FROM W
MT WAS GENERATING LIGHT SHOWERS OVER AREAS W AND N OF KBIL PER
RADAR IMAGERY AND OBSERVATIONS. MODELS WERE IN GOOD AGREEMENT IN
BRINGING THE FRONT INTO THE AREA EARLY THIS EVENING AND SLIDING IT
S THROUGH THE AREA TONIGHT. A BAND OF STRONG FRONTOGENESIS WILL
ACCOMPANY THE FRONT AND ISENTROPIC LIFT WILL DEVELOP OVER THE
WESTERN ZONES. SNOW WILL OVERSPREAD THE AREA FROM W TO E TONIGHT.
NOTED THE HRRR AND SREF HINTED AT SOME POSSIBLE FREEZING RAIN
EARLY IN THE EVENING BEFORE A CHANGEOVER TO SNOW...BUT RAP
SOUNDINGS SHOWED A QUICK WET BULB DOWN ONCE THE PRECIPITATION
BEGINS SO WILL NOT INCLUDE IT IN THE FORECAST AT THIS TIME. ALSO
SOUNDINGS SUPPORTED ICE DEVELOPMENT IN THE CLOUDS SO RESULT SHOULD
BE A RATHER QUICK CHANGEOVER TO SNOW THIS EVENING. GOOD DENDRITIC
GROWTH WILL ACCOMPANY THE LIFT AND MOISTURE RESULTING IN SEVERAL
INCHES OF SNOW ACCUMULATION OVERNIGHT WEST OF ROSEBUD COUNTY. IT
WILL BECOME WINDY OVERNIGHT DUE TO THE FRONTAL PASSAGE AND AREAS
LIKE JUDITH GAP AND KLVM COULD SEE NEAR WHITEOUT CONDITIONS.
TEMPERATURES BY FRI MORNING WILL BE IN THE SINGLE DIGITS ABOVE AND
BELOW ZERO.
STRONG ISENTROPIC LIFT WILL OVERSPREAD THE REGION FRIDAY AND
CONTINUE THROUGH SAT...BEFORE DIMINISHING SAT NIGHT. SHORTWAVE
ENERGY PASSING BY TO THE S OF THE AREA WILL AID IN GENERATING
THE ISENTROPIC LIFT. THE FRONTOGENESIS BAND WILL BE ALONG THE
MOUNTAINS AND FOOTHILLS ON FRI AND WILL MOVE S OF THE AREA FRI
NIGHT. STRONG JET DIVERGENCE WILL AID THE LIFT OVER THE AREA FRI
INTO SAT AS WELL. EXPECT AREAS OF BLOWING SNOW OVER THE REGION ON
FRI DUE TO WINDY CONDITIONS. THE BEST DENDRITIC GROWTH WILL SINK S
AND SW DURING THE DAY ON FRI AND WILL BE OVER THE FAR SW FRI NIGHT
AND SAT. SEVERAL INCHES OF SNOW WILL CONTINUE W OF ROSEBUD COUNTY
ON FRI WITH HIGHER ACCUMULATIONS IN THE MOUNTAINS. FRI NIGHT AND
SAT WILL HAVE SIMILAR ACCUMULATIONS. WINDS WILL BE LOWER FOR FRI
NIGHT AND SAT WITH LESS OF A THREAT OF BLOWING SNOW. SNOW WILL
WIND DOWN SAT NIGHT AS LIFT DECREASES OVER THE AREA.
HIGHS WILL BE IN THE SINGLE DIGITS AND TEENS ON FRI AND LOWS WILL
BE IN THE TEENS BELOW ZERO FRI NIGHT. TEMPERATURES WILL NOT RISE
ABOVE ZERO FOR SAT AND WILL BE VERY COLD SAT NIGHT AS 850 MB
TEMPERATURES APPROACH -30 DEGREES C. EXPECT DANGEROUS WIND CHILLS
ACROSS THE AREA FROM FRI ONWARD.
WILL CONTINUE THE WARNING FOR AREAS W OF ROSEBUD COUNTY FOR
MULTIPLE STORM IMPACTS...AND WILL ISSUE AN ADVISORY FOR THE
EASTERN ZONES...EXCEPT FOR FALLON COUNTY WHERE SNOW AMOUNTS WILL
BE LIGHT. ARTHUR
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
BITTERLY COLD TEMPERATURES AND WIND CHILLS WILL CONTINUE SUNDAY
INTO MONDAY BEFORE A MODERATION IN TEMPERATURES ARRIVES TUESDAY.
MODELS ARE IN FAIRLY GOOD AGREEMENT IN KEEPING A 500MB UPPER LOW
AND ASSOCIATED VORTICITY AREA OVER BRITISH COLUMBIA SUNDAY AND
MONDAY. THIS WILL RESULT IN AN UPPER LEVEL FLOW FROM THE
WEST/NORTHWEST KEEPING A MOIST PACIFIC FLOW ACROSS THE FORECAST
AREA. AT THE SURFACE...A STRONG BAROCLINIC ZONE WILL BE SITUATED
ACROSS THE ENTIRE EASTERN SLOPES OF THE ROCKY MOUNTAINS. ALTHOUGH
THE STRONG DYNAMICS FROM THIS CURRENT STORM WILL MAINLY BE OUT OF
THE AREA THERE WILL STILL BE CHANCES FOR SNOW SHOWERS BOTH DAYS.
TEMPERATURES WILL REMAIN BELOW ZERO DURING THE DAY SUNDAY BUT A
SLIGHT MODERATION WILL BE POSSIBLE MONDAY.
MODELS TRY TO QUICKLY RETREAT THE ARCTIC AIR BY TUESDAY WITH
READINGS WELL UP INTO THE 40S. HOWEVER...GIVEN EXPECTED SNOW COVER
WILL KEEP READINGS IN THE 20S AND 30S ACROSS THE AREA. HIGH
TEMPERATURES THIS TIME OF YEAR CAN BE DIFFICULT...ESPECIALLY WITH
SNOW COVER...AS STRONG EARLY MARCH SUN ANGLE CAN QUICKLY BOOST
TEMPERATURES FOR A FEW HOURS. IN ADDITION... WILL NEED TO WATCH
THE POSSIBILITY OF BLOWING SNOW AS SOME BRIEF GAP AND/OR DRAINAGE
WINDS MAY BE GUSTY AS THE ARCTIC RETREATS. AFTER SUNDAY...NO
STRONG STORM SYSTEM LOOKS TO IMPACT THE FORECAST AREA UNTIL NEAR
THE END OF NEXT WEEK AS MODELS BRING THE POSSIBILITY OF MORE SNOW.
HOOLEY
&&
.AVIATION...
SNOW WILL BEGIN ALONG AND WEST OF A KSHR-KBIL-ROUNDUP LINE BY 06Z
AND AREAS EAST BETWEEN 06Z AND 12Z. VFR FLIGHT CONDITIONS WILL
PREVAIL EARLY THIS EVENING BUT WILL BEGIN TO DETERIORATE BY MID
EVENING AS A STRONG ARCTIC FRONT MOVES THROUGH THE FORECAST AREA.
SNOW...HEAVY AT TIMES...WILL RESULT IN WIDESPREAD IFR TO LIFR
CONDITIONS AFTER 06Z. THESE CONDITIONS WILL CONTINUE THROUGH
SATURDAY. THE MOUNTAINS WILL BE OBSCURED. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
FRI SAT SUN MON TUE WED THU
-----------------------------------------------------------
BIL 008/009 912/909 917/905 916/015 007/032 015/037 023/030
++/S ++/S 73/S 33/S 23/S 32/S 22/S
LVM 010/015 908/903 914/006 912/024 013/035 017/039 027/036
++/S ++/S 74/S 43/S 33/S 42/S 33/S
HDN 007/012 913/905 919/901 918/014 002/030 013/034 020/029
++/S ++/S 73/S 33/S 22/S 32/S 22/S
MLS 002/005 915/909 920/902 919/008 000/026 011/031 017/023
66/S 77/S 52/S 22/S 12/S 22/S 22/S
4BQ 004/010 910/903 919/002 918/011 003/027 013/035 017/027
77/S 9+/S 62/S 22/S 12/S 21/B 12/S
BHK 902/002 917/908 921/901 920/005 903/022 015/031 012/022
45/S 56/S 42/S 22/S 12/S 21/B 12/S
SHR 014/015 909/901 914/005 915/019 008/035 016/039 020/035
9+/S ++/S 73/S 32/S 22/S 32/S 12/S
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER STORM WARNING IN EFFECT UNTIL 6 AM MST SUNDAY FOR
ZONES 28>30-34-35-39>42-57-63>65-67-68.
WINTER WEATHER ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO 6
AM MST SUNDAY FOR ZONES 31-32-36-37.
WINTER STORM WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 6 AM
MST SUNDAY FOR ZONES 38-58.
WINTER STORM WARNING IN EFFECT FROM 9 PM THIS EVENING TO 6 AM
MST SUNDAY FOR ZONES 56-66.
WY...WINTER STORM WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 6 AM
MST SUNDAY FOR ZONES 98-99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS ELKO NV
811 AM PST THU FEB 27 2014
.SYNOPSIS...THE RUMBLE OF THUNDER WILL BE POSSIBLE AS TWO
SEPARATE PACIFIC STORM SYSTEMS BRING MUCH NEEDED RAIN AND SNOW TO
NEVADA...THE FIRST ONE TODAY...AND THE SECOND ONE FRIDAY THROUGH
SATURDAY.
&&
.UPDATE...DID A QUICK UPDATE THIS MORNING WITH REGARDS TO SNOW
LEVEL...QPF...SNOW AMOUNTS...AND WEATHER GRIDS. 3KM HRRR AND NEW
SNOW SQUALL TOOL ARE PINGING AREAS OF LIGHT TO MODERATE SNOW SHOWERS
ACROSS PORTIONS OF CENTRAL AND EAST-CENTRAL NEVADA THIS
MORNING...AS WELL AS FURTHER NORTH IN PORTIONS OF ELKO COUNTY.
HAVE LOWERED SNOW LEVELS SLIGHTLY AND INCREASED QPF AND SNOW
AMOUNTS TO REFLECT QUICK HITTING SNOW SHOWERS THROUGH 18Z THIS
MORNING. SNOW LEVELS APPEAR TO BE AROUND THE 55000 TO 6000 FOOT
MARK...WITH ACCUMULATIONS OF AN INCH POSSIBLE IN LOCALIZED AREAS. TEXT
PRODUCTS WILL BE SENT SHORTLY...ALL OTHER GRIDS LOOK GOOD.
&&
.PREV DISCUSSION... /ISSUED AT 207 AM /
SHORT TERM...TODAY THROUGH SATURDAY. MOISTURE IS ATTACKING THE
SIERRAS AT THIS TIME WITH A COUPLE STRONG CONVECTIVE RAIN BANDS
ON THE SACRAMENTO SIDE NOTED ON RADAR. SHOWERS BEGAN TO SPILL
OVER THE SIERRA EAST SIDE AROUND MIDNIGHT DENOTED BY LIGHT RAIN AT
RENO FALLON AND LOVELOCK. EXPECTED TIME OF ARRIVAL AT ELKO IS
BETWEEN 3AM AND 4AM. AS OF 2 AM PST...TEMPERATURES ARE VERY WARM
IN THE 40S ALL AROUND AND ONLY CLOUD BANDING EAST OF BATTLE
MOUNTAIN. TWO DISTINCT SHORTWAVES WILL SPIN OFF THE PARENT PACIFIC
UPPER LOW FEATURE AND AFFECT THE GREAT BASIN. THE FIRST WILL
AFFECT THE STATE TODAY AND TONIGHT TO PROVIDE MUCH NEEDED
RAINFALL IN THE VALLEYS WITH MOUNTAIN SNOW ESSENTIALLY TIED UP
ABOVE 6000 FEET. NO MAJOR IMPACTS EXPECTED. THE SECOND SYSTEM
WILL ENTER THE GREAT BASIN DOMAIN FRIDAY AND LAST LONGER WHICH
WILL ALLOW COLDER AIR TO SLIDE IN FROM THE NORTH BEFORE THE
PRECIPITATION EXITS. THERE IS POTENTIAL FOR SOME IMPACTS FROM THIS
SYSTEM AS THE WEEKEND PROGRESSES.
TODAY. PRECIPITATION WILL SPREAD TO ALL PARTS OF THE STATE...WITH
LESSER CHANCES FOR PRECIPITATION FOR AREAS EAST OF THE RUBY
MOUNTAINS UNTIL THE AFTERNOON. ONCE THE UPPER LOW MOVES ONSHORE
EARLY THIS MORNING...THE CENTER OF THE LOW WILL SKIP THROUGH NORTHERN
CALIFORNIA AND OREGON AND MELD NORTHEAST INTO THE NORTHERN FLOW. THE
SPEED OF THE PASSING LOW WILL PROVIDE A ROBUST SOUTHWEST FLOW FOR
THE LKN CWFA AND THUNDERSTORM ACTIVITY WILL BE POSSIBLE AS THE
TROUGH AXIS PASSES OVER THE STATE EARLY IN THE AFTERNOON. MODEL QPF IS
GENEROUS HOWEVER THERE WILL BE SIERRA SHADOWING EFFECT TO DEAL
WITH. AREAS TO THE NORTH MAY NOT RECEIVE AS MUCH PRECIPITATION
EARLY. THERE MAY BE SOME RUMBLES OF THUNDER NEAR TONOPAH LATE IN
THE MORNING HOWEVER THE MOIST CORE AND INSTABILITY FAVORS EAST
CENTRAL NEVADA IN THE AFTERNOON. RAIN MAY MIX WITH SNOW IN THE
AFTERNOON AS SNOW LEVELS WILL BE LOWERING FROM 7000 FEET DOWN TO
AROUND 6000 FEET. LITTLE SNOW ACCUMULATION IS EXPECTED BELOW 6000
FEET HOWEVER AREAS AROUND 6500 FEET MAY RECEIVE UP TO 4 INCHES OF
SNOW ALL TOTAL TODAY. GUSTY WINDS TO 30 MPH ARE EXPECTED ACROSS
MUCH OF THE GREAT BASIN. HIGH TEMPERATURES WILL BE IN THE 50S.
TONIGHT. A WEAK HIGH PRESSURE RIDGE WILL BEGIN TO MOVE ACROSS THE
GREAT BASIN. SHOWERS WILL BE TAPERING OFF SOUTH TO NORTH AS
ANOTHER WEATHER MAKER GATHERS STRENGTH OUT OVER THE PACIFIC. SNOW
LEVELS WILL BE DROPPING TO AROUND 5500 FEET HOWEVER LITTLE SNOW
ACCUMULATION IS EXPECTED WITH THE EXPECTED DIMINISHING OF THE
SHOWER ACTIVITY. LOW TEMPERATURES WILL RANGE FROM THE MID 20S TO
THE MID 30S.
FRIDAY THROUGH SATURDAY. ANOTHER TROUGH OF LOW PRESSURE WILL MOVE
DOWN THE COAST OF CALIFORNIA FRIDAY AND MOVE ONSHORE OVER SOUTHERN
CALIFORNIA SATURDAY AFTERNOON. THE TRACK OF THIS LOW IS MUCH
FARTHER SOUTH THAN THE PREVIOUS ONE AND AS EARLY AS FRIDAY
MORNING...EXTREME AMOUNTS OF MOISTURE WILL BE SPREADING INTO
SOUTHERN CALIFORNIA AND BANKING UP AGAINST ALL MOUNTAIN RANGES
NEAR THE CALIFORNIA BORDER WITH NEVADA. THE MORE SOUTHERN
TRAJECTORY WILL ALLOW A STRONG INFLUX OF MOISTURE INTO CENTRAL
NEVADA WITH THE POTENTIAL FOR STRONG FLASH-FLOOD PRODUCING
THUNDERSTORMS SOUTH OF HIGHWAY 50. THERE MAY BE SOME RUMBLES OF
THUNDER NEAR TONOPAH LATE IN THE MORNING HOWEVER THE MOIST CORE
AND INSTABILITY AGAIN FAVORS EAST CENTRAL NEVADA IN THE AFTERNOON.
SNOW WILL BEGIN SPREADING ACROSS WESTERN NEVADA AROUND DAYBREAK
FRIDAY AND SPREAD TO ALL PARTS OF THE STATE BY FRIDAY AFTERNOON.
IMPACTS WILL BE GREATEST FOR AREAS SOUTH OF HIGHWAY 50 FROM FRIDAY
AFTERNOON THROUGH FRIDAY EVENING...FOLLOWED BY NORTHERN NEVADA
FRIDAY MIDNIGHT THROUGH SATURDAY MORNING. ELEVATIONS ABOVE 6000
FEET COULD RECEIVE ONE HALF FOOT OF SNOW. SNOW LEVELS WILL BE
DIPPING DOWN TO AROUND 5500 FEET EARLY SATURDAY SO SEVERAL INCHES
OF SNOW IS POSSIBLE AT THAT LEVEL...ESPECIALLY ACROSS NORTHEAST
NEVADA. LOW TEMPERATURES WILL BE IN THE 30S. HIGH TEMPERATURES
WILL RANGE FROM THE MID 40S TO AROUND 50.
LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY. WEAK TROF WITH SEVERAL
EMBEDDED SHORTWAVES OVER NEVADA WILL KEEP SHOWERS CONTINUING ACROSS
THE CWA SATURDAY NIGHT. MODELS HAVE A WEAK DIRTY RIDGE FOR ZONAL
FLOW OVER THE CWA SUNDAY THROUGH TUESDAY. WITH DOWNSLOPE CONDITIONS
DUE TO THE STRONG WESTERLY FLOW ALOFT...EXPECT SHOWERS WILL BE
MAINLY CONFINED TO THE WEST FACING SLOPES OF THE MOUNTAINS. THEN BY
WEDNESDAY...MODELS IN GENERAL AGREEMENT WITH BUILDING A RIDGE OVER
NEVADA AHEAD OF THE NEXT DIGGING UPSTREAM SYSTEM...THUS PUSHING THE
LOW LEVEL MOISTURE BRIEFLY NORTH OF NEVADA. WITH THE CWA UNDER A
ZONAL WESTERLY FLOW...TEMPERATURES WILL REMAIN 5 TO 10 DEGREES ABOVE
NORMAL THROUGH THE PERIOD.
AVIATION...RAIN SHOWERS...HEAVY AT TIMES...ARE EXPECTED TO
DEVELOP AT KWMC AND KTPH AROUND 11Z SPREADING ACROSS THE ENTIRE
AREA BY LATE THURSDAY MORNING. EXPECT POSSIBLE MVFR CONDITIONS IN
HEAVY SHOWERS FROM LOWERED CIGS/VIS. GUSTY WINDS TO 30 MPH WILL
DEVELOP BY THIS AFTERNOON.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
86/96
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
517 PM EST THU FEB 27 2014
.SYNOPSIS...
A REINFORCING THE ARCTIC AIR MASS WILL SPREAD OVER PENNSYLVANIA
TONIGHT WITH BITTERLY COLD WIND CHILLS OVER MUCH OF CENTRAL PA
THROUGH FRIDAY MORNING. SOME MODERATION IS EXPECTED ON SATURDAY
AS HIGH PRESSURE MOVES EAST OF THE REGION...AND THE FRONT LIFTS
NORTHWARD. IT WILL WAGGLE SOUTH AGAIN ON SUNDAY AHEAD OF A
MOIST SOUTHERN STREAM STORM SYSTEM THAT IS EXPECTED TO MOVE SOUTH
OF PA ON MONDAY. SIGNIFICANT WINTRY PRECIPITATION IS EXPECTED
ACROSS THE REGION SUNDAY INTO MONDAY...FOLLOWED BY FAIR AND
CONTINUED COLD WEATHER FOR TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
MOST INTENSE/ORGANIZED SNOW SQUALL ACTIVITY HAS RAPIDLY LIFTED
INTO THE POCONO PLATEAU AND TOWARD THE CATSKILLS REGION NY BY MID
AFTERNOON...BUT NUMEROUS SNOW SHOWERS WITH BRIEF SNOW BURSTS
CONTINUE ACROSS CENTRAL PA THANKS TO STEEP LOW LEVEL LAPSE RATES
AND SFC BASED CAPES UP TO 200 J/KG. RUC13 AND NAM12 DIAGNOSTICS
INDICATE RAPID DISSIPATION OF SNOW SHOWERS THROUGH 21/22Z FOLLOWED
BY CLEARING FOR MUCH OF CENTRAL AND SOUTH CENTRAL PA AS HIGH
PRESSURE BUILDS IN FROM THE OHIO VALLEY. LAKE CLOUDS SHOULD HANG
INTO EARLY FRIDAY MORNING ACROSS THE NORTH AND ESPECIALLY NORTHWEST.
MAIN CONCERN TONIGHT IS FOR DANGEROUS WIND CHILLS...AS STRONG
WINDS COMBINE WITH FALLING TEMPS DURING THIS AFTERNOON AND
EVENING. GOING WIND CHILL ADVISORY IN GOOD SHAPE TONIGHT INTO
TOMORROW. BUFKIT SOUNDINGS SUPPORT GUSTS UP TO 40KTS.
MIN TEMPS TONIGHT WILL DROP WELL BELOW ZERO UP NORTH...WITH -10F
TO -15F EXPECTED. SINGLE DIGITS BELOW ZERO WILL AFFECT THE LAUREL
HIGHLANDS...CENTRAL MOUNTAINS...ENDLESS MOUNTAINS AND LYCOMING
VALLEY...ZERO TO 5 ABOVE ELSEWHERE ACROSS SOUTH CENTRAL MOUNTAINS
AND LOWER SUSQ. EXTREMELY COLD FOR THIS TIME OF YEAR...BUT NO
RECORD LOWS EXPECTED DUE TO A FRIGID MORNING BACK IN 1934.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
ARCTIC SFC HIGH PRESSURE WILL REMAIN THE MAIN PLAYER FRIDAY AND
FRIDAY NIGHT FOR PA...WITH THE SFC HIGH MOVING WELL OFFSHORE BY
SATURDAY MORNING INTRODUCING A BRIEF MODERATING SPELL FOR SATURDAY.
MOSTLY SUNNY SKIES WITH LIGHT SFC WINDS ARE EXPECTED ON SATURDAY...
WHICH WILL BE MUCH MORE TOLERABLE TO FRIDAY CONDITIONS.
ENSEMBLE MEAN 925TEMPS OF ARND -15C WILL SUPPORT MAX TEMPS NO
BETTER THAN THE TEENS TO NR 20F...ARND 25F BELOW NORMAL FOR LATE
FEBRUARY.
FRIDAY NIGHT SHOULD REMAIN DRY...BUT WITH SOME INCREASING HIGH
CLOUDS LATE IN THE RETURN FLOW AROUND THE DEPARTING OFFSHORE SFC
HIGH. RESULTING MIN TEMPS WILL BE SOME 15 TO AS MUCH AS 20F WARMER
SATURDAY MORNING.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
ON SAT...STORM OF INTEREST FOR LATE WEEKEND/EARLY NEXT WEEK WILL
BEGIN WORKING ITS WAY FROM THE CALIF COAST EASTWARD. OVER PA...
FAST AND NEARLY ZONAL FLOW ALOFT AS SPOKES OF COLDER AIR ROTATING
AROUND A LOW ANCHORED NEAR HUDSON BAY GET SHUNTED TO OUR NORTH.
ONE NOTABLE SHORTWAVE SLIDING EASTWARD ACROSS S CANADA WILL DRAG A
SURFACE COLD FRONT THROUGH PA SAT NIGHT. AHEAD OF THAT...SOME
MILDER AIR WILL WORK INTO THE STATE ALONG WITH PLENTY OF CLOUDS.
A BIT OF LIGHT SNOW ALSO POSS...EMPHASIS ON LIGHT AS QPF AT BEST
IS JUST A FEW HUNDREDTHS...AND CONFINED TO THE NW MTNS AS SW FLOW
OVERRUNS RETREATING ARCTIC AIR MASS.
NORTHERN STREAM SHORTWAVE PASSING N OF THE GRT LKS WILL PUSH A
DYING COLD FRONT THRU CENTRAL PA SAT NIGHT. SCT LIGHT SNOW MAY
ACCOMPANY PASSAGE OF THIS FRONT MAINLY OVR THE N MTNS...WHILE AIR
MASS ACTUALLY BECOMES MILD ENOUGH FOR EITHER -SHRA OR -SHSN OVER
SOUTH. QPF AGAIN REMAINS LIGHT...A TENTH OF AN INCH OR LESS AT
BEST ALONG NY BORDER. ERODING FRONTAL BOUNDARY BECOMES STATIONARY
NEAR THE MASON DIXON LINE...ALLOWING MILDER AIR TO REMAIN IN PLACE
SOUTH OF IT ACROSS PORTIONS OF S PA...WITH READINGS ONLY FALLING
TO ARND 32F IN THE LOWER SUSQ.
REMNANTS OF THIS OLD FRONTAL BOUNDARY COMBINED WITH SOUTHERN
STREAM ENERGY WILL BECOME THE FOCUS FOR MID RANGE. MODEL GUIDANCE
IN QUITE GOOD AGREEMENT ON A SOUTHERN STREAM DISTURBANCE LIFTING
TOWARD PA LATE IN THE WEEKEND. CONFIDENCE CONTINUES TO INCREASE IN
A SIGNIFICANT BOUT OF WINTRY PRECIP FOR MUCH OF CENTRAL PA LATER
SUNDAY INTO MONDAY...AS PLUME OF GULF OF MEX MOISTURE OVERRUNS A
QUASI-STATIONARY BNDRY JUST S OF THE MASON DIXON. BOTH GEFS AND
OPER EC/CMC CONTINUE TO SUGGEST THERE WILL BE A NARROW SWATH OF
GREATER THAN AN INCH PRECIP ACROSS CENTRAL OR SOUTHERN PA...MAYBE
SLIDING JUST A BIT FURTHER SOUTH THAN PREV RUNS. BEST CHC FOR
SIGNIFICANT SNOW APPEARS TO BE ACROSS CENTRAL/PARTS OF NORTHERN
PA...WITH A GREATER CHC OF A WINTRY MIX OR EVEN A PERIOD OF RAIN
IN THE SOUTH /AND MUCH LOWER SNOW ACCUMS/...BEFORE COLDER AIR
AT LOWER LEVELS BEGINS TO SLIDE IN FROM THE NORTH TOWARD THE END
OF THE EVENT BRINGING BETTER CHANCES FOR PRECIP TO END AS A PERIOD
OF SNOW ON MONDAY.
MIDWEEK WILL BRING FAIR AND COLD WX /AROUND 15F BELOW NORMAL ALONG
WITH MORNING LOWS BACK INTO SINGLE DIGITS/ AS LARGE SFC HIGH PRES
SYSTEM BUILDS SE TOWARDS PA FROM CENTRAL CANADA. LATE WEEK LOOKS
TO BRING A BIT OF RELIEF FROM THE VERY CHILLY WEATHER AS COLDER
AIR RETREATS BACK TO THE NORTH AS WARMER SOUTHWEST FLOW HELPS TO
NUDGE TEMPS BACK TOWARD...YET STILL SLIGHTLY BELOW...NORMAL.
HEADING INTO NEXT WEEKEND...GFS/ECMWF SUGGESTING ANOTHER SOUTHERN
STREAM WAVE PROGGED TO IMPACT MAINLY SOUTHEAST STATES BEFORE
SLIDING OFF CAROLINA COAST.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
AS EXPECTED...RATHER ACTIVE SNOW SHOWERS MADE IT INTO THE LOWER
SUSQUEHANNA VALLEY THIS AFT...JUST TOOK A LITTLE LONGER TO GET
THERE.
MAIN CHANGE TO 21Z TAF PACKAGE WAS TO KEEP MENTION OF SNOW SHOWERS
AND GUSTY WINDS FURTHER OUT TO 01Z NOW...INSTEAD OF 23Z.
MOST OF THE HEAVIER SNOW SHOWERS NOW ACROSS THE SOUTHERN PART OF
THE STATE.
EARLIER DISCUSSION BELOW.
SNOW SHOWERS WILL CONTINUE TO DISSIPATE THIS AFTERNOON AND EVENING
AS INSTABILITY DECREASES. GUSTY WINDS WILL PERSIST INTO EARLY
EVENING...CONDITIONS WILL IMPROVE SIGNIFICANTLY BY 00Z. DOWNSLOPE
FLOW IN THE WAKE OF THE FRONT SHOULD BRING ALL SITES E OF THE MTS
BACK TO VFR WHILE MVFR CIGS/OCNL -SHSN LINGER ACRS WRN SXNS.
SFC HIGH PRES BUILDS INTO THE REGION TNGT ALLOWING WINDS TO
SUBSIDE INTO FRI MORNING.
OUTLOOK...
SAT...VFR TRENDING LOWER INTO SAT NGT IN -SN.
SUN-MON...MVFR/IFR LKLY IN SN AND/OR MIXED PCPN.
TUE-WED...MVFR POSS NW...VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM EST FRIDAY FOR PAZ004>006-
010>012-017-018-024-033-037-041-042.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD/RXR
AVIATION...DEVOIR/MARTIN/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
437 PM EST THU FEB 27 2014
.SYNOPSIS...
A REINFORCING THE ARCTIC AIR MASS WILL SPREAD OVER PENNSYLVANIA
TONIGHT WITH BITTERLY COLD WIND CHILLS OVER MUCH OF CENTRAL PA
THROUGH FRIDAY MORNING. SOME MODERATION IS EXPECTED ON SATURDAY
AS HIGH PRESSURE MOVES EAST OF THE REGION...AND THE FRONT LIFTS
NORTHWARD. IT WILL WAGGLE SOUTH AGAIN ON SUNDAY AHEAD OF A
MOIST SOUTHERN STREAM STORM SYSTEM THAT IS EXPECTED TO MOVE SOUTH
OF PA ON MONDAY. SIGNIFICANT WINTRY PRECIPITATION IS EXPECTED ACROSS
THE REGION SUNDAY INTO MONDAY...FOLLOWED BY FAIR AND CONTINUED
COLD WEATHER FOR TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
MOST INTENSE/ORGANIZED SNOW SQUALL ACTIVITY HAS RAPIDLY LIFTED
INTO THE POCONO PLATEAU AND TOWARD THE CATSKILLS REGION NY BY MID
AFTERNOON...BUT NUMEROUS SNOW SHOWERS WITH BRIEF SNOW BURSTS
CONTINUE ACROSS CENTRAL PA THANKS TO STEEP LOW LEVEL LAPSE RATES
AND SFC BASED CAPES UP TO 200 J/KG. RUC13 AND NAM12 DIAGNOSTICS
INDICATE RAPID DISSIPATION OF SNOW SHOWERS THROUGH 21/22Z FOLLOWED
BY CLEARING FOR MUCH OF CENTRAL AND SOUTH CENTRAL PA AS HIGH
PRESSURE BUILDS IN FROM THE OHIO VALLEY. LAKE CLOUDS SHOULD HANG
INTO EARLY FRIDAY MORNING ACROSS THE NORTH AND ESPECIALLY NORTHWEST.
MAIN CONCERN TONIGHT IS FOR DANGEROUS WIND CHILLS...AS STRONG
WINDS COMBINE WITH FALLING TEMPS DURING THIS AFTERNOON AND
EVENING. GOING WIND CHILL ADVISORY IN GOOD SHAPE TONIGHT INTO
TOMORROW. BUFKIT SOUNDINGS SUPPORT GUSTS UP TO 40KTS.
MIN TEMPS TONIGHT WILL DROP WELL BELOW ZERO UP NORTH...WITH -10F
TO -15F EXPECTED. SINGLE DIGITS BELOW ZERO WILL AFFECT THE LAUREL
HIGHLANDS...CENTRAL MOUNTAINS...ENDLESS MOUNTAINS AND LYCOMING
VALLEY...ZERO TO 5 ABOVE ELSEWHERE ACROSS SOUTH CENTRAL MOUNTAINS
AND LOWER SUSQ. EXTREMELY COLD FOR THIS TIME OF YEAR...BUT NO RECORD
LOWS EXPECTED DUE TO A FRIGID MORNING BACK IN 1934.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
ARCTIC SFC HIGH PRESSURE WILL REMAIN THE MAIN PLAYER FRIDAY AND
FRIDAY NIGHT FOR PA...WITH THE SFC HIGH MOVING WELL OFFSHORE BY
SATURDAY MORNING INTRODUCING A BRIEF MODERATING SPELL FOR SATURDAY.
MOSTLY SUNNY SKIES WITH LIGHT SFC WINDS ARE EXPECTED ON SATURDAY...
WHICH WILL BE MUCH MORE TOLERABLE TO FRIDAY CONDITIONS.
ENSEMBLE MEAN 925TEMPS OF ARND -15C WILL SUPPORT MAX TEMPS NO
BETTER THAN THE TEENS TO NR 20F...ARND 25F BELOW NORMAL FOR LATE
FEBRUARY.
FRIDAY NIGHT SHOULD REMAIN DRY...BUT WITH SOME INCREASING HIGH
CLOUDS LATE IN THE RETURN FLOW AROUND THE DEPARTING OFFSHORE SFC
HIGH. RESULTING MIN TEMPS WILL BE SOME 15 TO AS MUCH AS 20F WARMER
SATURDAY MORNING.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
ON SAT...STORM OF INTEREST FOR LATE WEEKEND/EARLY NEXT WEEK WILL
BEGIN WORKING ITS WAY FROM THE CALIF COAST EASTWARD. OVER PA...
FAST AND NEARLY ZONAL FLOW ALOFT AS SPOKES OF COLDER AIR ROTATING
AROUND A LOW ANCHORED NEAR HUDSON BAY GET SHUNTED TO OUR NORTH.
ONE NOTABLE SHORTWAVE SLIDING EASTWARD ACROSS S CANADA WILL DRAG A
SURFACE COLD FRONT THROUGH PA SAT NIGHT. AHEAD OF THAT...SOME
MILDER AIR WILL WORK INTO THE STATE ALONG WITH PLENTY OF CLOUDS.
A BIT OF LIGHT SNOW ALSO POSS...EMPHASIS ON LIGHT AS QPF AT BEST
IS JUST A FEW HUNDREDTHS...AND CONFINED TO THE NW MTNS AS SW FLOW
OVERRUNS RETREATING ARCTIC AIR MASS.
NORTHERN STREAM SHORTWAVE PASSING N OF THE GRT LKS WILL PUSH A
DYING COLD FRONT THRU CENTRAL PA SAT NIGHT. SCT LIGHT SNOW MAY
ACCOMPANY PASSAGE OF THIS FRONT MAINLY OVR THE N MTNS...WHILE AIR
MASS ACTUALLY BECOMES MILD ENOUGH FOR EITHER -SHRA OR -SHSN OVER
SOUTH. QPF AGAIN REMAINS LIGHT...A TENTH OF AN INCH OR LESS AT
BEST ALONG NY BORDER. ERODING FRONTAL BOUNDARY BECOMES STATIONARY
NEAR THE MASON DIXON LINE...ALLOWING MILDER AIR TO REMAIN IN PLACE
SOUTH OF IT ACROSS PORTIONS OF S PA...WITH READINGS ONLY FALLING
TO ARND 32F IN THE LOWER SUSQ.
REMNANTS OF THIS OLD FRONTAL BOUNDARY COMBINED WITH SOUTHERN
STREAM ENERGY WILL BECOME THE FOCUS FOR MID RANGE. MODEL GUIDANCE
IN QUITE GOOD AGREEMENT ON A SOUTHERN STREAM DISTURBANCE LIFTING
TOWARD PA LATE IN THE WEEKEND. CONFIDENCE CONTINUES TO INCREASE IN
A SIGNIFICANT BOUT OF WINTRY PRECIP FOR MUCH OF CENTRAL PA LATER
SUNDAY INTO MONDAY...AS PLUME OF GULF OF MEX MOISTURE OVERRUNS A
QUASI-STATIONARY BNDRY JUST S OF THE MASON DIXON. BOTH GEFS AND
OPER EC/CMC CONTINUE TO SUGGEST THERE WILL BE A NARROW SWATH OF
GREATER THAN AN INCH PRECIP ACROSS CENTRAL OR SOUTHERN PA...MAYBE
SLIDING JUST A BIT FURTHER SOUTH THAN PREV RUNS. BEST CHC FOR
SIGNIFICANT SNOW APPEARS TO BE ACROSS CENTRAL/PARTS OF NORTHERN
PA...WITH A GREATER CHC OF A WINTRY MIX OR EVEN A PERIOD OF RAIN
IN THE SOUTH /AND MUCH LOWER SNOW ACCUMS/...BEFORE COLDER AIR
AT LOWER LEVELS BEGINS TO SLIDE IN FROM THE NORTH TOWARD THE END
OF THE EVENT BRINGING BETTER CHANCES FOR PRECIP TO END AS A PERIOD
OF SNOW ON MONDAY.
MIDWEEK WILL BRING FAIR AND COLD WX /AROUND 15F BELOW NORMAL ALONG
WITH MORNING LOWS BACK INTO SINGLE DIGITS/ AS LARGE SFC HIGH PRES
SYSTEM BUILDS SE TOWARDS PA FROM CENTRAL CANADA. LATE WEEK LOOKS
TO BRING A BIT OF RELIEF FROM THE VERY CHILLY WEATHER AS COLDER
AIR RETREATS BACK TO THE NORTH AS WARMER SOUTHWEST FLOW HELPS TO
NUDGE TEMPS BACK TOWARD...YET STILL SLIGHTLY BELOW...NORMAL.
HEADING INTO NEXT WEEKEND...GFS/ECMWF SUGGESTING ANOTHER SOUTHERN
STREAM WAVE PROGGED TO IMPACT MAINLY SOUTHEAST STATES BEFORE
SLIDING OFF CAROLINA COAST.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
SNOW SHOWERS WILL CONTINUE TO DISSIPATE THIS AFTERNOON AND EVENING
AS INSTABILITY DECREASES. GUSTY WINDS WILL PERSIST INTO EARLY
EVENING...CONDITIONS WILL IMPROVE SIGNIFICANTLY BY 00Z. DOWNSLOPE
FLOW IN THE WAKE OF THE FRONT SHOULD BRING ALL SITES E OF THE MTS
BACK TO VFR WHILE MVFR CIGS/OCNL -SHSN LINGER ACRS WRN SXNS.
SFC HIGH PRES BUILDS INTO THE REGION TNGT ALLOWING WINDS TO
SUBSIDE INTO FRI MORNING.
OUTLOOK...
FRI...VFR.
SAT...VFR TRENDING LOWER INTO SAT NGT IN -SN.
SUN-MON...MVFR/IFR LKLY IN SN AND/OR MIXED PCPN.
TUE-WED...MVFR POSS NW...VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM EST FRIDAY FOR PAZ004>006-
010>012-017-018-024-033-037-041-042.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD/RXR
AVIATION...DEVOIR/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
303 PM EST THU FEB 27 2014
.SYNOPSIS...
A REINFORCING THE ARCTIC AIR MASS WILL SPREAD OVER PENNSYLVANIA
TONIGHT WITH BITTERLY COLD WIND CHILLS OVER MUCH OF CENTRAL PA
THROUGH FRIDAY MORNING. SOME MODERATION IS EXPECTED ON SATURDAY
AS HIGH PRESSURE MOVES EAST OF THE REGION...AND THE FRONT LIFTS
NORTHWARD. IT WILL WAGGLE SOUTH AGAIN ON SUNDAY AHEAD OF A
MOIST SOUTHERN STREAM STORM SYSTEM THAT IS EXPECTED TO MOVE SOUTH
OF PA ON MONDAY. SIGNIFICANT WINTRY PRECIPITATION IS EXPECTED ACROSS
THE REGION SUNDAY INTO MONDAY...FOLLOWED BY FAIR AND CONTINUED
COLD WEATHER FOR TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
MOST INTENSE/ORGANIZED SNOW SQUALL ACTIVITY HAS RAPIDLY LIFTED
INTO THE POCONO PLATEAU AND TOWARD THE CATSKILLS REGION NY BY MID
AFTERNOON...BUT NUMEROUS SNOW SHOWERS WITH BRIEF SNOW BURSTS
CONTINUE ACROSS CENTRAL PA THANKS TO STEEP LOW LEVEL LAPSE RATES
AND SFC BASED CAPES UP TO 200 J/KG. RUC13 AND NAM12 DIAGNOSTICS
INDICATE RAPID DISSIPATION OF SNOW SHOWERS THROUGH 21/22Z FOLLOWED
BY CLEARING FOR MUCH OF CENTRAL AND SOUTH CENTRAL PA AS HIGH
PRESSURE BUILDS IN FROM THE OHIO VALLEY. LAKE CLOUDS SHOULD HANG
INTO EARLY FRIDAY MORNING ACROSS THE NORTH AND ESPECIALLY NORTHWEST.
MAIN CONCERN TONIGHT IS FOR DANGEROUS WIND CHILLS...AS STRONG
WINDS COMBINE WITH FALLING TEMPS DURING THIS AFTERNOON AND
EVENING. GOING WIND CHILL ADVISORY IN GOOD SHAPE TONIGHT INTO
TOMORROW. BUFKIT SOUNDINGS SUPPORT GUSTS UP TO 40KTS.
MIN TEMPS TONIGHT WILL DROP WELL BELOW ZERO UP NORTH...WITH -10F
TO -15F EXPECTED. SINGLE DIGITS BELOW ZERO WILL AFFECT THE LAUREL
HIGHLANDS...CENTRAL MOUNTAINS...ENDLESS MOUNTAINS AND LYCOMING
VALLEY...ZERO TO 5 ABOVE ELSEWHERE ACROSS SOUTH CENTRAL MOUNTAINS
AND LOWER SUSQ. EXTREMELY COLD FOR THIS TIME OF YEAR...BUT NO RECORD
LOWS EXPECTED DUE TO A FRIGID MORNING BACK IN 1934.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
ARCTIC SFC HIGH PRESSURE WILL REMAIN THE MAIN PLAYER FRIDAY AND
FRIDAY NIGHT FOR PA...WITH THE SFC HIGH MOVING WELL OFFSHORE BY
SATURDAY MORNING INTRODUCING A BRIEF MODERATING SPELL FOR SATURDAY.
MOSTLY SUNNY SKIES WITH LIGHT SFC WINDS ARE EXPECTED ON SATURDAY...
WHICH WILL BE MUCH MORE TOLERABLE TO FRIDAY CONDITIONS.
ENSEMBLE MEAN 925TEMPS OF ARND -15C WILL SUPPORT MAX TEMPS NO
BETTER THAN THE TEENS TO NR 20F...ARND 25F BELOW NORMAL FOR LATE
FEBRUARY.
FRIDAY NIGHT SHOULD REMAIN DRY...BUT WITH SOME INCREASING HIGH
CLOUDS LATE IN THE RETURN FLOW AROUND THE DEPARTING OFFSHORE SFC
HIGH. RESULTING MIN TEMPS WILL BE SOME 15 TO AS MUCH AS 20F WARMER
SATURDAY MORNING.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
DEEP UPPER TROF IS PROGGED TO RAPIDLY LIFT OUT BY SATURDAY...
ALLOWING MILDER AIR TO WORK INTO THE STATE. PLENTY OF CLOUDS
SHOULD ACCOMPANY THE RETURN OF MILDER WX SAT AND PERHAPS A BIT OF
VERY LGT SNOW...AS SOUTHERLY FLOW OVERRUNS RETREATING ARCTIC AIR
MASS. BLEND OF LATEST MED RANGE QPF SUGGEST ANY ACCUMS WOULD BE
VERY LIGHT AND CONFINED TO THE NW MTNS.
NORTHERN STREAM SHORTWAVE PASSING N OF THE GRT LKS WILL PUSH A
DYING COLD FRONT THRU CENTRAL PA SAT NIGHT. A FEW -SHSN MAY
ACCOMPANY PASSAGE OF THIS FRONT OVR THE N MTNS...WHILE AIR MASS
ACTUALLY BECOMES MILD ENOUGH FOR EITHER -SHRA OR -SHSN OVER SOUTH.
CONSALL AND OPER EC BOTH SUPPORT MILD TEMPS SAT NIGHT ACROSS
SOUTHERN PA...WITH READINGS ONLY FALLING TO ARND 32F.
FOCUS OF THE MED RANGE FCST REMAINS ON SOUTHERN STREAM DISTURBANCE
LIFTING TOWARD PA LATE IN THE WEEKEND. CONFIDENCE CONTINUES TO
INCREASE IN A SIGNIFICANT BOUT OF WINTRY PRECIP FOR MUCH OF
CENTRAL PA SUNDAY INTO MONDAY...AS PLUME OF GULF OF MEX MOISTURE
OVERRUNS A QUASI-STATIONARY BNDRY JUST S OF THE MASON DIXON. BOTH
GEFS AND OPER EC/CMC SUGGEST THERE WILL BE A NARROW SWATH OF
GREATER THAN AN INCH PRECIP ACROSS CENTRAL OR SOUTHERN PA. BEST
CHC FOR SIGNIFICANT SNOW STILL APPEARS TO BE ACROSS CENTRAL/NORTHERN
PA...WITH A GREATER CHC OF A WINTRY MIX OR RAIN IN THE SOUTH.
BULK OF MED RANGE GUIDANCE INDICATES FAIR AND COLD WX TUE/WED...AS
LG SFC HIGH PRES SYSTEM BUILDS SE TOWARDS PA FROM CENTRAL CANADA.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
SNOW SHOWERS WILL CONTINUE TO DISSIPATE THIS AFTERNOON AND EVENING
AS INSTABILITY DECREASES. GUSTY WINDS WILL PERSIST INTO EARLY
EVENING...CONDITIONS WILL IMPROVE SIGNIFICANTLY BY 00Z. DOWNSLOPE
FLOW IN THE WAKE OF THE FRONT SHOULD BRING ALL SITES E OF THE MTS
BACK TO VFR WHILE MVFR CIGS/OCNL -SHSN LINGER ACRS WRN SXNS.
SFC HIGH PRES BUILDS INTO THE REGION TNGT ALLOWING WINDS TO
SUBSIDE INTO FRI MORNING.
OUTLOOK...
FRI...VFR.
SAT...VFR TRENDING LOWER INTO SAT NGT IN -SN.
SUN-MON...MVFR/IFR LKLY IN SN AND/OR MIXED PCPN.
TUE-WED...MVFR POSS NW...VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM EST FRIDAY FOR PAZ004>006-
010>012-017-018-024-033-037-041-042.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD
AVIATION...DEVOIR/RXR
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1247 PM CST THU FEB 27 2014
.DISCUSSION...OVERCAST CLOUD DECK CONTINUES TO EXPAND EASTWARD AND
IS SHOWING NO SIGNS OF ERODING YET. UPDATED CLOUD COVER ACROSS
CENTRAL AND WESTERN AREAS FOR AFTERNOON AND LOWERED TEMPS A
CATEGORY ACROSS THIS AREA.
&&
.PREV DISCUSSION... /ISSUED 1128 AM CST THU FEB 27 2014/
DISCUSSION...UPDATE FOR 18Z AVIATION.
AVIATION...OVC DECK RANGING FROM 3000-4000 FEET ALONG AND WEST OF
A BKS-ALI-COT LINE. RUC13 AND NAM12 SOUNDINGS SHOWING A GRADUAL
ERODING OF THIS DECK LATER IN THE AFTERNOON...POSSIBLY BECOMING
SCT. OTHERWISE ACROSS EASTERN AREAS MAINLY CLR SKIES. NE TO E
WINDS 5-12 KTS ACROSS EASTERN AREAS BECOMING SE THIS AFTERNOON.
BKN MVFR DECK MAY DEVELOP ACROSS EASTERN AREAS EARLY FRI MORNING.
IN ADDITION...MAY BE SOME PATCHY FOG RESULTING IN IFR TO MVFR
VISIBILITIES FROM ALI-VCT TOWARDS SUNRISE FRI MORNING.
PREV DISCUSSION... /ISSUED 923 AM CST THU FEB 27 2014/
DISCUSSION...OVERCAST CLOUD DECK AROUND 2500-3000 FEET PERSISTS
OUT ACROSS THE WESTERN BRUSH COUNTRY AND RIO GRANDE PLAINS. NAM12
AND GFS TIME SERIES INDICATE THE OVERCAST LAYER IS THIN...AND BOTH
INSIST THE DECK WILL SCATTER OUT LATE THIS AFTERNOON. UNTIL THIS
HAPPENS...INCREASED CLOUD IN THE FORECAST THROUGH THE REMAINDER OF
THE MORNING AND EARLY AFTERNOON ACROSS THIS REGION...THEN SHOWED
PARTLY CLOUDY TO MOSTLY CLEAR SKIES DEVELOPING LATE AFTERNOON INTO
THE EVENING. ALSO LOWERED FORECAST HIGHS BY A COUPLE OF DECREES.
REST OF THE FORECAST ACROSS EASTERN AREAS LOOKS IN GOOD SHAPE AND
NO CHANGES WERE MADE.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 57 51 80 66 80 / 0 10 10 10 10
VICTORIA 57 46 76 64 79 / 0 10 10 10 10
LAREDO 58 55 85 64 89 / 0 0 10 10 10
ALICE 58 49 84 64 84 / 0 10 10 10 10
ROCKPORT 54 52 75 65 75 / 0 10 10 10 10
COTULLA 57 46 82 60 85 / 0 0 10 10 10
KINGSVILLE 58 50 83 66 83 / 0 10 10 10 10
NAVY CORPUS 54 52 74 65 76 / 0 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
JR/76...SHORT TERM
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1128 AM CST THU FEB 27 2014
.DISCUSSION...UPDATE FOR 18Z AVIATION.
&&
.AVIATION...OVC DECK RANGING FROM 3000-4000 FEET ALONG AND WEST OF
A BKS-ALI-COT LINE. RUC13 AND NAM12 SOUNDINGS SHOWING A GRADUAL
ERODING OF THIS DECK LATER IN THE AFTERNOON...POSSIBLY BECOMING
SCT. OTHERWISE ACROSS EASTERN AREAS MAINLY CLR SKIES. NE TO E
WINDS 5-12 KTS ACROSS EASTERN AREAS BECOMING SE THIS AFTERNOON.
BKN MVFR DECK MAY DEVELOP ACROSS EASTERN AREAS EARLY FRI MORNING.
IN ADDITION...MAY BE SOME PATCHY FOG RESULTING IN IFR TO MVFR
VISIBILITIES FROM ALI-VCT TOWARDS SUNRISE FRI MORNING.
&&
.PREV DISCUSSION... /ISSUED 923 AM CST THU FEB 27 2014/
DISCUSSION...OVERCAST CLOUD DECK AROUND 2500-3000 FEET PERSISTS
OUT ACROSS THE WESTERN BRUSH COUNTRY AND RIO GRANDE PLAINS. NAM12
AND GFS TIME SERIES INDICATE THE OVERCAST LAYER IS THIN...AND BOTH
INSIST THE DECK WILL SCATTER OUT LATE THIS AFTERNOON. UNTIL THIS
HAPPENS...INCREASED CLOUD IN THE FORECAST THROUGH THE REMAINDER OF
THE MORNING AND EARLY AFTERNOON ACROSS THIS REGION...THEN SHOWED
PARTLY CLOUDY TO MOSTLY CLEAR SKIES DEVELOPING LATE AFTERNOON INTO
THE EVENING. ALSO LOWERED FORECAST HIGHS BY A COUPLE OF DECREES.
REST OF THE FORECAST ACROSS EASTERN AREAS LOOKS IN GOOD SHAPE AND
NO CHANGES WERE MADE.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 57 51 80 66 80 / 0 10 10 10 10
VICTORIA 57 46 76 64 79 / 0 10 10 10 10
LAREDO 62 55 85 64 89 / 0 0 10 10 10
ALICE 60 49 84 64 84 / 0 10 10 10 10
ROCKPORT 54 52 75 65 75 / 0 10 10 10 10
COTULLA 61 46 82 60 85 / 0 0 10 10 10
KINGSVILLE 60 50 83 66 83 / 0 10 10 10 10
NAVY CORPUS 54 52 74 65 76 / 0 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
JR/76...AVIATION
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
330 PM CST THU FEB 27 2014
.TONIGHT - CONFIDENCE...MEDIUM
MAIN CONCERN IS EXTENT OF TEMP DROPOFF BEFORE CLOUDS INCREASE LATER
IN THE NIGHT. VERY DRY AIRMASS IS SETTLING ACROSS SRN WI. DEW POINTS
INTO THE MINUS TEENS. 2 METER TEMPS...ESP THE GFS...HAVE REALLY
BACKED OFF ON THE LOWS. MEANWHILE THE RAP WITH A STRONG INVERSION IS
A LOW OF -31 AT KMSN. MEANWHILE THE NAM SHOWS MORE OF AN ISOTHERMAL
SETUP WITH WARMER LOWS. DROPPED LOWS A BIT MORE THAN PRIOR FORECAST
ESPECIALLY IN WESTERN CWA DUE TO THE VERY LOW DEWPOINTS AND IDEAL
RADIATIONAL SETUP WITH LIGHT WIND/CLEAR SKY REGIME FOR MUCH OF THE
NIGHT WITH THE PROXIMITY OF SURFACE HIGH. WAA CLOUDS INCREASE LATER
IN THE NIGHT...BUT THESE CLOUDS ARE STILL A LONG WAYS OFF IN SD/NEB.
EXPECT THE INITIAL SOUTHERLY RETURN 925 FLOW LATER TONIGHT TO NOT
MIX DOWN TO WARRANT WIND CHILL HEADLINE CONCERNS...ESP WITH ANY
MIXING LIKELY TO COINCIDE WITH THE CLOUD INCREASE AND SUBSEQUENT SFC
TEMP MODIFICATION. SO CONFIDENCE IN WIND CHILL CRITERIA BEING MET
FOR ANY LENGTH OF TIME IN THE WESTERN CWA IS QUITE LOW AT THIS TIME.
.FRIDAY - CONFIDENCE...MEDIUM
HIGH SHIFTS EAST AND 850/925 WAA WILL BE WELL UNDERWAY AHEAD OF NEXT
SYSTEM. FORCING MECHANISMS ARE QUESTIONABLE. VERY LITTLE IN THE WAY
OF VORTICITY TO LATCH ONTO...FLOW BECOMES MORE WESTERLY. UPPER JET
DYNAMICS ARE FAIRLY WEAK. THERE IS A HINT OF LOWER LEVEL
FRONTOGENESIS AND WEAK TO MODERATE ISENTROPIC ASCENT WITH INCREASING
SATURATION IN THE NORTHWEST CWA AS THE AFTERNOON WEARS ON. SO WILL
KEY HIGHEST POPS THERE.
.FRIDAY NIGHT...FORECAST CONFIDENCE - MEDIUM.
WEAKENING MID-LEVEL SHORT WAVE AND LOW LEVEL WARM AIR ADVECTION
SHOULD RESULT IN A PERIOD OF -SN OVER MOST OF THE AREA FRIDAY NIGHT.
SYSTEM WILL BE WEAKENING AS IT MOVES THROUGH BUT ENOUGH COLUMN
MOISTURE AND SYNOPTIC SCALE LIFT TO SQUEEZE OUT THE LIGHT PRECIP.
EXPECT -SN TO SPREAD INTO WESTERN CWA DURING THE EARLY
EVENING...EVENTUALLY CLEARING THE EASTERN AREAS BY LATE IN THE
NIGHT. SNOW LIQUID RATIOS AROUND 14 TO 1 BUT DENDRITES SHOULD REMAIN
SMALL. HENCE LOOKING AT ONE HALF INCH TO 2 INCH AMOUNTS WITH THE
HIGHEST TOTALS IN THE NORTH AND WEST.
.SATURDAY AND SATURDAY NIGHT...FORECAST CONFIDENCE - MEDIUM.
BRIEF LULL IN PRECIPITATION EXPECTED LATER FRIDAY NIGHT INTO
SATURDAY MORNING BEFORE NEXT PERIOD OF -SN DEVELOPS. ALL SHORT TERM
GUIDANCE SHOWS SOUTHERN WISCONSIN AFFECTED BY RIGHT ENTRANCE REGION
OF PASSING UPPER JET SATURDAY AFTN AND EVENING. WITH LOW LEVEL
BAROCLINIC ZONE REMAINING NEARBY...WEAK WARM AIR ADVECTION LOWERS
CONDENSATION PRESSURE DEFICITS RAPIDLY TO LESS THAN 10MB WITH WEAK
ISENTROPIC OMEGA. MORE OF THE CLOUD BEARING LAYER WILL BE IN A
FAVORABLE DENDRITIC SNOW GROWTH REGION FOR A TIME. WITH SLIGHTLY
HIGHER SNOW LIQUID RATIOS EXPECTED AND BETTER ENHANCED
FORCING...THINKING POTENTIAL FOR 2 TO 4 INCH SNOWFALL OVER MOST OF
THE AREA SATURDAY AFTN AND EVENING.
.SUNDAY...FORECAST CONFIDENCE - LOW.
SYNOPTIC SCALE FORCING SLIDES OFF TO THE EAST LATE SATURDAY NIGHT
HOWEVER LATEST NAM TRYING TO SHOW A PERIOD OF ONSHORE WINDS AS
MESOSCALE LOW PRESSURE TROUGH MOVES WWD ACROSS LAKE MI INTO FAR
EASTERN WI ON SUNDAY. GFS DOES NOT SHOW THIS FEATURE WITH WEAKER
ONSHORE WINDS AND POTENTIAL LAKE EFFECT REMAINING FARTHER SOUTH OVER
NORTHEAST IL. TOO MUCH UNCERTAINTY TO LEAN ONE WAY OR THE OTHER.
FOR NOW WILL KEEP SMALL POPS FOR -SHSN IN FOR SUNDAY. EXPANDING LAKE
ICE OVER NEARSHORE AND WESTERN OPEN WATERS WILL ALSO HELP TO CUT
BACK ON LAKE EFFECT.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. FORECAST CONFIDENCE -
MEDIUM TRENDING TOWARD LOW.
MORE ZONAL FLOW AT THE MID-LEVELS CONTINUES INTO EARLY NEXT WEEK
WITH SLIGHT WARMING IN SURFACE TEMPERATURES. ZONAL FLOW AND DRIER
AIR ASSOCIATED WITH SPRAWLING HIGH PRESSURE OVER THE NORTHERN PLAINS
HELPS TO DIVERT DEVELOPING LOW PRESSURE SYSTEM TO THE SOUTHEAST OF
WISCONSIN SUNDAY NIGHT AND MONDAY. HOWEVER MAY BE A PERIOD OF
NORTHEAST WINDS ON BACKSIDE OF LOW MOVING ACROSS TN VALLEY REGION.
GFS FORECAST SOUNDINGS FOR MONDAY SHOW MINIMAL LOW LEVEL MOISTURE
AND WEAKER LOW TO MID LEVEL FLOW...SO FOR NOW WL AVOID ADDING
THREAT OF LAKE EFFECT TO EASTERN AREAS EXCEPT IN THE FAR SOUTHEAST.
LOW PRESSURE SYSTEM AFFECTING EAST COAST REGION EARLY NEXT WEEK WILL
RESULT IN MID-LEVEL STEERING FLOW BECOMING MORE NORTHWEST FOR A
TIME. THIS CARRIES SPRAWLING HIGH PRESSURE SYSTEM FROM THE NORTHERN
PLAINS GRADUALLY EWD ACROSS WESTERN GREAT LAKES REGION ON TUESDAY.
HOWEVER AGREEMENT IN MEDIUM RANGE GUIDANCE IN WEAK TROUGH MOVING
SOUTHEAST ACROSS WI IN THE MONDAY NIGHT/TUE TIME FRAME...SO WL NEED
TO CONTINUE SMALL POPS FOR -SN. CLOUDS FROM THIS SYSTEM WILL ALSO
PREVENT RADIATIONAL COOLING AND BITTER COLD TEMPS MON NGT.
HIGH EVENTUALLY MOVES OFF TO THE EAST BY WEDNESDAY. MEDIUM RANGE
GUIDANCE DIVERGES AT THIS POINT AS ECMWF TURNS A BIT MORE WEST TO
SOUTHWEST AT THE MID-LEVELS AHEAD OF NEXT APPROACHING DISTURBANCE.
DGEX ALSO IN THIS CAMP WHILE GFS STEERING FLOW REMAINS MORE
NORTHWEST AND COLDER. BOTH DGEX AND ECMWF AGRESSIVE ON BRINGING
SURGE OF WARM AIR ADVECTION QPF INTO THE AREA LATER WED/WED
NGT...WHILE GFS SLOWER. NO MATTER...ALL MEDIUM RANGE GUIDANCE IN
AGREEMENT ON STRONGER MID-LEVEL TROUGH MOVING THROUGH THE REGION IN
THE THU/THU NGT TIME FRAME...SO MOST LATER PERIODS WL LIKELY HAVE
LOW POPS FOR -SN.
GFS 5-DAY 500H HEIGHTS RUNNING AROUND 100METERS BELOW NORMAL NEXT
SEVERAL DAYS BUT BEGIN TO SLOWLY MODERATE SO THAT BY THE SECOND WEEK
OF MARCH 500H HEIGHTS ACTUALLY AROUND NORMAL. HENCE WILL REMAIN
COLD AND BELOW NORMAL THROUGH THE EXTENDED FORECAST PERIOD BUT
RECORD COLD NOT EXPECTED.
&&
.AVIATION/00Z TAFS/...VFR MOSTLY SKC EXPECTED INTO THIS EVENING.
WILL START TO SEE SOME WAA MID CLOUDS RETURN LATER TONIGHT THROUGH
FRIDAY MORNING. ANY SNOW WITH NEXT SYSTEM EXPECTED TO HOLD OFF UNTIL
FRIDAY EVENING FOR THE TAF SITES. EXPECT MVFR CIGS/VSBYS TO INCREASE
ACROSS SRN WI DURING FRIDAY EVENING PER NAM MOS CIG FCST AND BUFKIT
LOW LEVEL SATURATION TRENDS.
&&
.MARINE...GRADIENT WILL TIGHTEN BACK UP AS HIGH SHIFTS EAST AND SSE
FLOW DEVELOPS BETWEEN THE DEPARTED HIGH AND APPROACHING LOW. HOISTED
SMALL CRAFT FOR GUSTY SSE WINDS FROM MID MORNING THROUGH LATE
AFTERNOON.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 9 AM TO 6 PM CST FRIDAY
FOR LMZ643>646.
&&
$$
TONIGHT/FRIDAY AND AVIATION/MARINE...PC
FRIDAY NIGHT THROUGH THURSDAY...MBK