March 2, 2012 Forecast Discussion

000
FXUS61 KALY 030350
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
1050 PM EST FRI MAR 2 2012

.SYNOPSIS…
A LOW PRESSURE SYSTEM WILL APPROACH AND MOVE ACROSS THE REGION
TONIGHT AND SATURDAY. A WINTRY MIX OF PRECIPITATION WILL OCCUR
ACROSS A PORTION OF THE AREA TONIGHT WITH A CHANGEOVER TO RAIN.
COLDER AIR WILL BE USHERED IN ON BRISK AND GUSTY WINDS IN THE
WAKE OF THE SYSTEM. ON MONDAY…HIGH PRESSURE WILL BUILD IN OVER
THE EASTERN UNITED STATES…AND DRIFT TO THE SEABOARD BY MIDWEEK.

&&

.NEAR TERM /THROUGH SATURDAY/…
MIXED PRECIPITATION OVERSPREADING FORECAST AREA. HAVE HAD REPORTS
OF SNOW…SLEET…FREEZING RAIN AND RAIN THIS EVENING. ONLY MINOR
CHANGES TO FORECAST MAINLY FOR TEMPERATURES AND P-TYPE.

EXPANDED THE WINTER WEATHER ADVISORY AND STARTED IT EARLY FOR
FREEZING RAIN THREAT. ADDED THE EASTERN CATSKILLS…NORTHERN AND
CENTRAL TACONICS AND NORTHERN LITCHFIELD COUNTY. PLUS STARTED THE
ADVISORY AT 03Z/SATURDAY. CONCERN IS FOR THE P-TYPE AT ONSET OF
PRECIPITATION AS TEMPERATURES ARE IN THE UPPER 20S TO LOWER 30S
MAINLY ACROSS THE HIGHER TERRAIN. TIMING OF THE PRECIPITATION WAS
ON TRACK ONLY MINOR ADJUSTMENT MADE. DID UPDATE THE WEATHER GRIDS
USING A BLEND OF THE NAM AND GFS FOR THE THERMAL PROFILE. AREAS
THAT EXPECT THE FREEZING RAIN THE LONGEST ARE THE LOCATIONS PRONE
TO IT ACROSS A PORTION OF THE SOUTHERN ADIRONDACKS AND SOUTHERN
VERMONT. WHERE SNOW OCCURS WHICH WOULD BE MAINLY ACROSS THE
NORTHERN PORTION OF THE FORECAST AREA LOOKING AT UP TO AN INCH. AS
FOR THE ICE ACCRETION UP TO A TENTH IS EXPECTED.

TEMPERATURES SHOULD RISE EVERYWHERE TOWARD SUNRISE SATURDAY…AND
THEN RISE MORE RAPIDLY THROUGH THE MORNING. SO…ANY MIXED
PRECIPITATION SHOULD CHANGE TO RAIN EVERYWHERE…WITH ADVISORY
AREAS CHANGING TO RAIN THE LATEST. ONCE THE RAIN ENDS…THE
STRENGTHENING SURFACE LOW WILL EXIT AND WINDS WILL SHIFT TO WEST
TO NORTHWEST. AS THE SURFACE LOW DEEPENS RAPIDLY…THE PRESSURE
GRADIENT WILL TIGHTEN AND THE WINDS COULD FLIRT WITH ADVISORY
CRITERIA IN NORTHERN AREAS…BUT THE MAIN CORE OF THE WIND LOOKS
TO TRACK THROUGH THE ST LAWRENCE VALLEY…SO CAPPING GUSTS AT 45
MPH IN NORTHERN AREAS…AND IT WILL ALSO BE BREEZY/WINDY IN ALL
AREAS.

DEPENDING ON WHEN THE CLOUDS EXIT…SOME SUNSHINE AND WIND SHOULD
AID IN DECENT MIXING…HELPING TEMPERATURES TO REACH THE 40S TO
LOWER 50S.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/…
DEEPER COLD AIR LOOKS DELAYED UNTIL THE UPPER IMPULSE TRACKS EAST
OF THE REGION MONDAY AND BEYOND…BUT GRADUAL COLD ADVECTION
SHOULD OCCUR SUNDAY THROUGH MONDAY. MEAN UPPER TROUGH AXIS SHOULD
BE ALONG THE GREAT LAKES AND GRADUALLY COOLING BOUNDARY LAYER
TEMPERATURES COULD SUPPORT SOME LAKE EFFECT SNOW SHOWER ACTIVITY
IN THE WESTERN MOHAWK VALLEY AND SOUTHERN ADIRONDACKS.

THERE SHOULD BE JUST SOME PERIODS OF CLOUDS AND MAYBE A FLURRY IN
MOST OTHER AREAS. WITH THE PERIODS OF CLOUDS AND THE GRADUAL
COOLING…HIGHS SUNDAY IN THE UPPER 30S TO MID 40S…SOME MID TO
UPPER 20S IN THE SOUTHERN ADIRONDACKS. HIGHS MONDAY IN THE
30S…WITH LOWER TO MID 20S IN THE SOUTHERN ADIRONDACKS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/…
STRONG HIGH PRESSURE WILL BE PASSING OVER THE REGION FOR MONDAY
NIGHT INTO TUESDAY. THIS SHOULD PROMOTE PLENTY OF
SUBSIDENCE…WHICH WILL KEEP SKIES MAINLY CLEAR AND WINDS LIGHT.
GOOD RADIATIONAL COOLING WILL TAKE PLACE ON MON NIGHT…WHICH WILL
MAKE FOR A VERY COLD NIGHT. MIN TEMPS LOOK TO RANGE FROM THE LOW
TEENS IN THE HUDSON VALLEY TO NEAR -10 DEGREES F ACROSS THE CENTRAL
ADIRONDACKS. TEMPS ON TUESDAY WILL BE A LITTLE WARMER THAN
MONDAY…BUT STILL CLOSE TO NORMAL WITH 30S FOR MOST AREAS.

THE HIGH WILL START TO SHIFT EASTWARD OFF THE COAST FOR TUESDAY
NIGHT INTO WEDNESDAY…BUT SHOULD STILL REMAIN CLOSE ENOUGH TO KEEP
THINGS DRY. STRONG RIDGING WILL DEVELOP OVER THE EASTERN
SEABOARD…AND THE S-SW FLOW AROUND THIS SFC HIGH WILL PROMOTE
PLENTY OF WARM AIR IN BEING PULLED INTO THE REGION. MIN TEMPS ON
TUESDAY NIGHT WILL STILL GET BELOW FREEZING IN MOST AREAS WITH THE
MAINLY CLEAR SKIES…BUT HIGHS ON WEDNESDAY WILL BE ABOVE NORMAL AND
CONSIDERABLY WARMER THAN EARLIER IN THE WEEK…WITH HIGHS NEARING 50
FOR MOST PLACES.

A COLD FRONT WILL BE APPROACHING FOR THE LATE WEEK PERIOD…BUT THE
MODELS ARE DISAGREEING ON ITS EXACT TIMING. THE 12 UTC GFS WAS
FASTER THAN THE 00 UTC ECMWF AND 12 UTC GGEM…AND THE 12 UTC GEFS
ALSO SHOWS SOME SPREAD REGARDING TIMING AND QPF. FOR NOW…WE HAVE
SIDED WITH THE ECMWF/GGEM SOLUTION…AND WILL DELAY MOST OF THE
PRECIP UNTIL MAINLY FRIDAY WITH CHC POPS…AS OPPOSED TO BRING IT
THROUGH ON THURSDAY AS THE GFS SUGGESTS. IT/S POSSIBLE THAT EVEN
FRIDAY COULD BE DRY IF THE RIDGE HOLDS STRONG…AND TEMPS WILL
CONTINUE TO BE ABOVE NORMAL. ONCE THE STORM DOES AFFECT US….IT
SHOULD TRACK WELL TO OUR NORTHWEST…WITH ONLY THE COLD FRONT
CROSSING OUR AREA…SO PRECIP SHOULD BE ALL LIQUID…ESP CONSIDERING
HOW WARM IT WILL BE AHEAD OF THE BOUNDARY. HAVE CONTINUED TO GO
ABOVE GUIDANCE FOR TEMPS FOR THURSDAY/THURSDAY NIGHT…WITH THE
EXPECTATION OF THE FRONT CROSSING SOMETIME FOR FRIDAY INTO FRIDAY
NIGHT AT THE EARLIEST.

&&

.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/…
MVFR CONDITIONS DUE TO CEILINGS EXPECTED TO LOWER TO IFR FOR BOTH
CEILINGS AND VISIBILITY AS PRECIPITATION MOVES IN AS A WARM FRONT
APPROACHES. P-TYPE IN AN ISSUE. AT KPOU RAIN. AT KALB…A MIX TO
START CHANGING TO RAIN. KGFL IS TOUGH EXCEPT SNOW TO START AND
TEMPERATURE TO DROP TO FREEZING OR BELOW RESULTING IN FREEZING
RAIN FOR MUCH OF THE OVERNIGHT AS WARMER AIR WORKS IN WAY IN
ALOFT. A CHANGEOVER TO RAIN IS EXPECTED BEFORE THE PRECIPITATION
ENDS SATURDAY MORNING. AN IMPROVEMENT TO VFR CONDITIONS IS
EXPECTED BY EARLY AFTERNOON IN THE WAKE OF THE COLD/OCCLUDED
FRONT.

LOW PRESSURE SYSTEM COLD/OCCLUDED FRONT BLAST THROUGH ON SATURDAY.
WILL HAVE EAST TO SOUTHEAST FLOW AHEAD OF THE SYSTEM`S WARM FRONT
WITH WINDS SHIFTING TO SOUTH THEN SOUTHWEST TO WEST AS COLD/OCCLUDED
FRONT SWINGS THROUGH.

HAVE KEPT LOW LEVEL WIND SHEAR IN TAFS FOR LATE EVENING THROUGH
EARLY SATURDAY MORNING…AS A SOUTHEAST LOW LEVEL JET MOVES OVER
THE AREA.

OUTLOOK…
SAT NIGHT…VFR. WINDY.
SAT NIGHT-MON…VFR. BREEZY.
MON NIGHT-WED…VFR. NO SIG WX.

&&

.HYDROLOGY…
NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT WEEK. THERE WILL BE
0.30 TO 0.50 INCH QPF…MAINLY AS RAIN IN MOST AREAS FRIDAY NIGHT
INTO SAT…BUT A PORTION OF THAT WILL BEGIN AS SNOW…SLEET AND
SOME LIGHT FREEZING RAIN IN THE HIGHER TERRAIN AND AREAS NORTH OF
CAPITAL DISTRICT.

SNOW MELT AND SOME RUNOFF MAY RESULT IN WITHIN BANK RISES OVER
THE WEEKEND. CONDITIONS WILL TURN QUITE COLD SATURDAY NIGHT INTO
MONDAY…ENDING ANY SNOW MELT SATURDAY NIGHT. THERE WILL BE
SCATTERED LIGHT SNOW AND RAIN SHOWERS MAINLY WEST OVER THE
WEEKEND. IT WILL BE DRY LATE MONDAY INTO FRIDAY WITH ABOVE TO MUCH
ABOVE NORMAL TEMPERATURES FROM WEDNESDAY TO FRIDAY. SNOW MELT WILL
INCREASE LATE IN THE WEEK AS A RESULT BUT WILL NOT BE SUFFICIENT
TO RESULT IN ANYTHING MORE THAN MODEST INCREASE IN FLOW RATES AND
RIVER LEVELS.

FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES…INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS…PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.

&&

.ALY WATCHES/WARNINGS/ADVISORIES…
CT…WINTER WEATHER ADVISORY UNTIL 10 AM EST SATURDAY FOR CTZ001.
NY…WINTER WEATHER ADVISORY UNTIL 10 AM EST SATURDAY FOR NYZ032-
033-038>043-047-048-051-054-058-061-063-082>084.
MA…WINTER WEATHER ADVISORY UNTIL 10 AM EST SATURDAY FOR MAZ001-
025.
VT…WINTER WEATHER ADVISORY UNTIL 10 AM EST SATURDAY FOR
VTZ013>015.

&&

$$
SYNOPSIS…IAA/NAS
NEAR TERM…IAA/NAS
SHORT TERM…NAS
LONG TERM…FRUGIS
AVIATION…IAA/JPV
HYDROLOGY…NAS

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