000
FXUS61 KALY 270533
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
1230 AM EST WED FEB 27 2013
.SYNOPSIS…
A DOUBLE BARRELED LOW PRESSURE WILL APPROACH FROM THE OHIO VALLEY AS
WELL AS THE MID ATLANTIC REGION. THIS SYSTEM LOOKS TO BRING
SNOW…RAIN AND OR MIXED PRECIPITATION TO OUR REGION TONIGHT INTO
THURSDAY. AS THE STORM ONLY SLOWLY DRIFTS EASTWARD ACROSS OUR REGION
AND INTO NEW ENGLAND…ADDITIONAL LIGHT RAIN OR SNOW WILL BE
POSSIBLE WELL INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/…
AS OF 1230 AM EST…RADAR INDICATED THAT PRECIPITATION WAS WORKING
INTO THE GREATER CAPITAL DISTRICT. HOWEVER…RIGHT HERE AT OUR
OFFICE…IT JUST STARTED TO PRECIPITATE BUT IT IS SO LIGHT IT IS
HARD TO TELL WHAT TYPE IT IS YET. THIS SHIELD OF PRECIPITATION
SHOULD CONTINUE MARCHING NORTHWARD AND OVERSPREAD THE ENTIRE CWA BY
400 AM.
SO FAR…DUAL POL RADAR PRODUCTS AND GROUND OBSERVATIONS INDICATE
MOSTLY RAIN WAS FALLING IN THE VALLEY AREAS. HOWEVER…AT HIGHER
ELEVATIONS LOOK TO BE PICKING UP SLEET AND LARGE SNOW FLAKES. AS
PRECIPITATION INITIALLY FALLS INTO RELATIVELY DRY AIR…EVAPORATIVE
COOLING LOOKS TO COOL THE COLUMN DOWN A COUPLE OF DEGREES…PRETTY
CLOSE TO THE FREEZING MARK IN VALLEY LOCATIONS…FREEZING OR A BIT
BELOW HIGHER ELEVATIONS.
ADJUSTED HOURLY GRIDS AND SOME PTYPES BASED ON THIS ASSUMPTION BUT
OVERALL LEFT THE "BIG PICTURE" ALONE INCLUDING KEEPING ALL HEADLINES
IN TACT.
FOR THE OVERNIGHT…LOOK FOR PRECIPITATION…MOSTLY RAIN IN THE
VALLEYS…AT LEAST THROUGH THE CAPITAL DISTRICT…OCCASIONALLY
MIXING WITH SLEET AND OR SNOW. HIGHER ELEVATIONS ABOVE ABOUT 1500
FEET LOOK TO HAVE MORE SNOW…MIXED WITH SLEET THROUGH THE
NIGHT…ACCUMULATING UP TO SEVERAL INCHES BY DAWN.
SNOW WILL WILL BE HEAVY AT TIMES ACROSS THE EASTERN
CATSKILLS…SOUTHERN ADIRONDACKS…SOUTHERN VERMONT AND NORTHERN
BERKSHIRES…WHICH IS WHERE THE HIGHEST SNOW-LIQUID RATIOS HAVE BEEN
FORECAST.
OVERNIGHT LOWS WILL RANGE FROM THE MID 30S MID HUDSON VALLEY AND
LOWER LITCHFIELD…LOWER 30S MOST OTHER VALLEY LOCATIONS…25 TO 30
HIGHER TERRAIN AND THE UPPER HUDSON VALLEY NORTH OF SARATOGA
SPRINGS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/…
MODEL GUIDANCE HAS COME INTO BETTER CONSENSUS REGARDING THE
EVOLUTION OF THE SURFACE AND UPPER LEVEL PATTERN. IT NOW LOOKS LIKE
THE DOUBLE-BARREL LOW WILL MORE GRADUALLY LIFT NORTHWARD LATE
TONIGHT THROUGH WEDNESDAY AND CONSOLIDATE OVER WESTERN NY BY
WEDNESDAY NIGHT. THIS IS A MORE NORTHERLY POSITION COMPARED TO
PREVIOUS MODEL RUNS…WITH THE PRIMARY LOW BECOMING DOMINANT. THE
IMPLICATION FOR OUR AREA IS THAT WARM ENOUGH AIR WILL BE ABLE TO
WORK NORTHWARD AND ESPECIALLY INTO VALLEY LOCATIONS FOR SNOW TO
CHANGE TO RAIN WEDNESDAY MORNING…WITH RAIN CONTINUING THROUGH THE
DAY. EVEN FOR THE HIGHER TERRAIN SOUTH OF THE CAPITAL REGION WHERE
THERE WILL BE A COMPLEX MIX OF SNOW…SLEET…AND SOME POSSIBLE
FREEZING RAIN.
STEADY PRECIPITATION SHOULD CONTINUE THROUGH MUCH OF THE DAY…AS
THE SOUTHEASTERLY LOW LEVEL JET CONTINUES TO AID IN ATLANTIC
MOISTURE TRANSPORT. SNOW-LIQUID RATIOS WILL DECREASE SIGNIFICANTLY
FOR AREAS OUTSIDE THE HIGHEST ELEVATIONS…WHICH WILL LIMIT SNOW
ACCUMULATIONS STARTING LATE WEDNESDAY MORNING. THE RESULT IS A
RATHER COMPLICATED SNOWFALL FORECAST MAP WITH HIGHLY VARYING SNOW
ACCUMULATIONS…HEAVILY BASED ON ELEVATION AND TRANSITIONING
PRECIPITATION TYPES.
THE STRONGEST WINDS ACROSS THE ADVISORY AREA WILL START TO SUBSIDE
AROUND MID AFTERNOON…AS THE CORE OF THE LOW LEVEL JET SHIFTS NORTH
OF THE AREA.
SURFACE TEMPERATURES ARE EXPECTED TO RISE INTO THE UPPER 30S TO
AROUND 40 FOR MOST VALLEY LOCATIONS…WITH GENERALLY MID 30S OVER
THE HIGHER TERRAIN. THIS WILL MAKE FOR A RATHER WET SNOWFALL FOR
AREAS THAT RECEIVE ACCUMULATING SNOW.
THE SPRAWLING SYSTEM WILL BECOME VERTICALLY STACKED OVER WESTERN NEW
YORK WEDNESDAY NIGHT….WITH PRECIPITATION BECOMING MORE
INTERMITTENT AND LIGHTER AS THE FLOW TURNS MORE SOUTH-SOUTHWESTERLY
ALOFT WITH ATLANTIC MOISTURE FEED DIMINISHING. BOUNDARY LAYER
TEMPERATURES WILL CONTINUE TO SUPPORT RAIN IN THE LOWER ELEVATIONS
WEDNESDAY EVENING…WITH RAIN/SNOW IN THE HIGHER TERRAIN. SOME
COOLING ALOFT OVERNIGHT MAY ALLOW THE RAIN TO CHANGE BACK TO
SNOW/SLEET…BUT ANY ACCUMULATIONS WILL BE VERY LIGHT. A CHANGEOVER
TO PURE SNOW SHOULD OCCUR OVER THE HIGHER TERRAIN…WITH ADDITIONAL
LIGHT ACCUMULATIONS.
THE WINTER WEATHER HEADLINES EXPIRE BY SUNRISE THURSDAY
MORNING…ALTHOUGH LIGHT PRECIP WILL CONTINUE DURING THE DAY
THURSDAY THROUGH THURSDAY NIGHT. WITH LOW FILLING AND MEANDERING
EASTWARD ACROSS THE AREA IT WILL BE CONTINUED DREARY AND DAMP…WITH
OCCASIONAL HIGHER ELEVATION LIGHT SNOW AND LOWER ELEVATION RAIN.
WITH THE TRACK OF THE LOW MAINLY RIGHT OVER THE AREA…SURFACE
TEMPERATURES ARE AGAIN EXPECTED TO WARM TO WELL ABOVE FREEZING IN
VALLEY LOCATIONS ON THURSDAY WITH SLOW COOLING THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/…
THE LONG TERM PERIOD WILL BE DOMINATED BY A DRIER PERIOD TO START
OUT THE FIRST WEEK OF MARCH AS A BROAD UPPER-LEVEL TROUGH PERSISTS
ACROSS THE REGION.
AT THE START OF THE LONG TERM PERIOD…A BROAD UPPER-LEVEL TROUGH
WILL BE SITUATED ACROSS THE NORTHEAST…KEEPING CHANCES FOR
PRECIPITATION DURING THE DAY FRIDAY WITH MOSTLY CLOUDY SKIES…AS
SOME MOISTURE MAY BE THROWN BACK FAR ENOUGH WEST TO ALLOW FOR MAINLY
OROGRAPHICALLY-INDUCED SNOW SHOWERS IN THE HIGHER TERRAIN WITH
RAIN/SNOW SHOWERS IN VALLEY LOCATIONS. UNLIKE THE SYSTEM AFFECTING
THE SHORT TERM PERIOD…PRECIPITATION AMOUNTS LOOK TO BE LIGHT…BUT
A COUPLE OF INCHES OF SNOWFALL COULD FALL IN THE ADIRONDACKS AND
SOUTHERN GREENS.
AS THE UPPER-LEVEL LOW SLOWLY EXITS THROUGH THE WEEKEND…IT LOOKS
THAT MUCH OF THE FORECAST AREA WILL BE DRY BUT UNDER CONTINUED
MOSTLY CLOUDY SKIES.
DRY CONDITIONS LOOK TO CONTINUE INTO EARLY NEXT WEEK WITH WEAK HIGH
PRESSURE BUILDING IN THE LOW-LEVELS. HAVE CONFINED SLIGHT CHANCE
POPS TO THE ADIRONDACKS HOWEVER AS THE UPPER-LEVEL TROUGH THAT
SLOWLY EXITED THE REGION DURING THE WEEKEND MOLDS INTO MORE OF A
LONGWAVE TROUGH…RESULTING IN A BROAD RETROGRADING TROUGH ACROSS
THE EASTERN THIRD OF THE CONUS…WITH WEAK IMPULSES ROTATING DOWN
THROUGH SOUTHERN CANADA PROVIDING ENOUGH LIFT FOR SOME WIDELY
SCATTERED SNOW SHOWERS. THIS WEATHER PATTERN LOOKS TO PERSIST
THROUGH THE MIDDLE OF NEXT WEEK…BEFORE LONG RANGE GUIDANCE HINTS
AT SOME PACIFIC ENERGY KICKING THE LONGWAVE TROUGH OUT OF THE REGION.
TEMPERATURES THROUGH THE LONG TERM PERIOD WILL BE NEAR NORMAL WITH
GENERALLY IN THE UPPER 20S TO UPPER 30S AND LOWS IN THE SINGLE
DIGITS/TEENS IN HIGHER TERRAIN TO LOWER 20S IN THE HUDSON VALLEY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/…
A COMPLEX STORM SYSTEM WILL IMPACT THE REGION TONIGHT THROUGH
WEDNESDAY…AS HIGH PRESSURE MOVES EAST OF THE REGION THIS AFTERNOON.
VFR CONDITIONS ARE EXPECTED PRIOR TO MIDNIGHT…AS CLOUDS THICKEN
AND LOWER THIS EVENING. SOME STRATUS BTWN 3.5-4.5 KFT WILL
CONTINUE TO DRIFT IN OVER THE REGION BENEATH THE HIGH CLOUDS.
A STRATUS DECK SHOULD FORM ALONG THE LEADING EDGE OF THE WARM
ADVECTION PCPN LATER THIS EVENING. THE THERMAL ADVECTION PCPN
ARRIVES AHEAD OF A SECONDARY LOW PRESSURE SYSTEM BTWN 05Z-09Z FROM
SOUTH TO NORTH ACROSS THE REGION. THE INITIAL SURGE OF PCPN MAY
COOL THE COLUMN DOWN FOR SNOW AT KPOU/KALB/KPSF/KGFL. EXPECT
WIDESPREAD IFR/LIFR CONDITIONS TO IMPACT THE TERMINALS IN THE
SNOW. THE GFS/NAM MODEL SOUNDINGS INDICATE A RAPID TRANSITION TO
RAIN AT KPOU BTWN 07Z- 10Z…THEN NORTH TO KALB BY 13Z. WE
FOLLOWED CLOSE TO THIS TREND IN THE TAFS THERE. KPSF AND KGFL ARE
EXPECTED TO HAVE A MIXTURE OF RAIN AND SNOW BY THE LATE MORNING.
WIDESPREAD IFR CIGS/VSBYS ARE EXPECTED IN RAIN THROUGH THE
AFTERNOON AT ALL THE SITES.
THE WINDS WILL BE SE TO NE AT 5-10 KTS OVERNIGHT INTO WED
MORNING. THE LOW-LEVEL JET AT 2 KFT AGL WILL INCREASE FROM THE
E/SE AT 40-50 KTS AT POU TO KPSF BTWN 07Z-09Z. LLWS GROUPS WERE
ADDED FROM THAT TIME UNTIL 16Z/WED. KALB IS A LITTLE UNCERTAIN IN
THE IMPACT OF ANY WIND SHEAR…SO WE WILL CONTINUE TO MONITOR.
HOWEVER…A WIND SHEAR GROUP WAS ADDED AT KGFL IN THE LATE
MORNING.
OUTLOOK…
WED…MVFR/IFR. PERIODS OF RAIN.
WED NIGHT…MVFR/IFR. RAIN/SNOW LIKELY
MAINLY IN THE EVENING.
THU-FRI…VFR/MVFR. CHC -SHSN/-SHRA.
SAT-SUN…VFR. NO SIG WX.
&&
.HYDROLOGY…
A SLOW MOVING STORM SYSTEM IS EXPECTED TO BRING A HALF TO GREATER
THAN AN INCH OF LIQUID EQUIVALENT QPF TO THE AREA WITH SNOW…RAIN
AND OR MIXED PRECIPITATION. THE BEST CHANCE FOR RAIN WILL BE IN
VALLEY LOCATIONS WEDNESDAY INTO WEDNESDAY NIGHT. TEMPERATURES ARE
ONLY EXPECTED RISE INTO THE UPPER 30S TO LOWER 40S FOR HIGHS ON
WEDNESDAY…SO EVEN WHERE IT RAINS SNOW MELT AND RUNOFF WILL NOT BE
EXTREME. THERE COULD BE SOME MINOR FLOODING OF POOR DRAINAGE
LOCATIONS…ESPECIALLY WITH FROZEN GROUND. OTHERWISE…MOST AREAS
WITH A SNOW PACK WILL EITHER SEE THE SNOW PACK GROW OR WILL HAVE
RAIN/MIXED PRECIP SOAK IN WITH TEMPERATURES MAINLY IN THE 30S. SO
RUNOFF WILL GENERALLY BE LIMITED TO THE SOUTHEAST HALF OF THE AREA.
THE HEAVIEST QPF IS EXPECTED OVER THE HIGHER TERRAIN…ESPECIALLY
EAST-SOUTHEAST FACING SLOPES/FOOTHILLS…ALTHOUGH THE MAJORITY OF
THE PRECIP SHOULD FALL AS A MIX INCLUDING SNOW WHICH WILL LIMIT
RUNOFF POTENTIAL THERE.
PRECIPITATION COULD CHANGE BACK TO SNOW OR SLEET LATE WEDNESDAY
NIGHT INTO THURSDAY MORNING AS THE STORM SYSTEM SLOWLY DRIFTS
EASTWARD ACROSS THE AREA…BUT COULD CHANGE BACK TO RAIN IN VALLEY
LOCATIONS BY THURSDAY AFTERNOON AS SURFACE TEMPERATURES WARM. LIGHT
RAIN/SNOW COULD LINGER INTO FRIDAY.
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…WINTER WEATHER ADVISORY UNTIL 6 AM EST THURSDAY FOR NYZ032-
038>041-047-048-051-083.
WINTER STORM WARNING UNTIL 6 AM EST THURSDAY FOR NYZ033-042-
058-063-082.
WIND ADVISORY FROM 5 AM EARLY THIS MORNING TO 3 PM EST THIS
AFTERNOON FOR NYZ054.
MA…WINTER WEATHER ADVISORY UNTIL 6 AM EST THURSDAY FOR MAZ025.
WINTER STORM WARNING UNTIL 6 AM EST THURSDAY FOR MAZ001.
WIND ADVISORY FROM 5 AM EARLY THIS MORNING TO 3 PM EST THIS
AFTERNOON FOR MAZ001.
VT…WINTER STORM WARNING UNTIL 6 AM EST THURSDAY FOR VTZ013>015.
WIND ADVISORY FROM 5 AM EARLY THIS MORNING TO 3 PM EST THIS
AFTERNOON FOR VTZ013-014.
&&
$$
SYNOPSIS…HWJIV
NEAR TERM…HWJIV/NAS
SHORT TERM…JPV
LONG TERM…IRL
AVIATION…WASULA
HYDROLOGY…JPV
000
FXUS61 KALY 270223
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
923 PM EST TUE FEB 26 2013
.SYNOPSIS…
HIGH PRESSURE WILL SHIFT NORTHEASTWARD INTO THE CANADIAN MARITIMES
TONIGHT…AS A COMPLEX LOW PRESSURE SYSTEM APPROACHES FROM THE OHIO
VALLEY AND MID ATLANTIC REGION. THIS SYSTEM LOOKS TO BRING
SNOW…RAIN AND OR MIXED PRECIPITATION TO OUR REGION TONIGHT INTO
THURSDAY. AS THE STORM ONLY SLOWLY DRIFTS EASTWARD ACROSS OUR REGION
AND INTO NEW ENGLAND…ADDITIONAL LIGHT RAIN OR SNOW WILL BE
POSSIBLE WELL INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/…
BASED ON LATEST RADAR AND SATELLITE TRENDS…FORECAST AND ONSET OF
PRECIPITATION LOOK TO BE ON TRACK. TWEAKED TEMPERATURES AND POPS TO
BETTER REFLECT CURRENT OBSERVATIONS AND TRENDS.
REASONING BEHIND THE HEADLINES DISCUSSED IN PREV DISC BELOW…
THE FOLLOWING HEADLINES HAVE BEEN ISSUED AS THE SYSTEM APPROACHES
TONIGHT. WINTER STORM WARNINGS HAVE BEEN POSTED FOR MUCH OF THE
SOUTHERN ADIRONDACKS….EASTERN CATSKILLS…AS WELL AS SOUTHERN
VERMONT AND NORTHERN BERKSHIRES. DUE TO EAST-SOUTHEAST DOWNSLOPE
EFFECTS…THE WARNING FOR BENNINGTON COUNTY AND NORTHERN BERKSHIRE
COUNTY IS FOR ELEVATIONS ABOVE 1500 FT.
WINTER WEATHER ADVISORIES HAVE BEEN POSTED FOR THE MOHAWK
VALLEY…NORTHERN HERKIMER COUNTY…THE SCHOHARIE
VALLEY…HELDERBERGS…AND FOOTHILLS OF THE SOUTHEAST ADIRONDACKS.
THE ADVISORY IS FOR SNOWFALL AT ELEVATIONS ABOVE 750 FEET.
WIND ADVISORIES HAVE ALSO BEEN ISSUED FOR STRONG EAST-SOUTHEAST
WINDS IN FAVORED AREAS OF THE SOUTHERN GREEN MOUNTAINS IN
VERMONT…THE NORTHERN BERKSHIRES AND EASTERN RENSSELAER COUNTY.
ELSEWHERE…FOR THE HUDSON VALLEY…TACONICS…AND LITCHFIELD
HILLS…ONLY A COATING TO A FEW INCHES OF SNOW IS EXPECTED TONIGHT
INTO EARLY WEDNESDAY…BEFORE CHANGING OVER TO RAIN AS WARMER AIR
WORK INTO LOWER ELEVATIONS.
IN TERMS OF TIMING…PRECIPITATION IS EXPECTED TO BEGIN THIS
EVENING…MAINLY SOUTH OF ALBANY INITIALLY THEN RAPIDLY SPREADING
NORTHWARD ENCOMPASSING THE ENTIRE AREA AFTER MIDNIGHT AS ISENTROPIC
LIFT INCREASES SUBSTANTIALLY…AS THE DOUBLE-BARREL LOW LIFTS
NORTHWARD INTO INDIANA/OHIO TO PENNSYLVANIA. AIDING MOISTURE
TRANSPORT WILL BE A STRENGTHENING E-SE LOW LEVEL JET OF 50+ KT
AROUND 925-850MB…AS HIGH PRESSURE SETTLES IN ACROSS THE CANADIAN
MARITIMES. DUE TO TEMPERATURES WARMING INTO THE UPPER 30S TO LOWER
40S IN MOST VALLEY LOCATIONS TODAY AND CLOUDS QUICKLY
THICKENING…IT WILL BE WARM ENOUGH FOR THE PRECIP TO START BRIEFLY
AS RAIN THEN CHANGE TO SNOW AS EVAPORATIONAL COOLING OCCURS. A
PERIOD OF SNOW IS EXPECTED FOR MUCH OF THE AREA LATE
TONIGHT…BEFORE WARMING STARTS TO OCCUR BY WEDNESDAY MORNING
ESPECIALLY ACROSS SOUTHERN AREAS.
SNOW WILL WILL BE HEAVY AT TIMES ACROSS THE EASTERN
CATSKILLS…SOUTHERN ADIRONDACKS…SOUTHERN VERMONT AND NORTHERN
BERKSHIRES…WHICH IS WHERE THE HIGHEST SNOW-LIQUID RATIOS HAVE BEEN
FORECAST.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/…
MODEL GUIDANCE HAS COME INTO BETTER CONSENSUS REGARDING THE
EVOLUTION OF THE SURFACE AND UPPER LEVEL PATTERN. IT NOW LOOKS LIKE
THE DOUBLE-BARREL LOW WILL MORE GRADUALLY LIFT NORTHWARD LATE
TONIGHT THROUGH WEDNESDAY AND CONSOLIDATE OVER WESTERN NY BY
WEDNESDAY NIGHT. THIS IS A MORE NORTHERLY POSITION COMPARED TO
PREVIOUS MODEL RUNS…WITH THE PRIMARY LOW BECOMING DOMINANT. THE
IMPLICATION FOR OUR AREA IS THAT WARM ENOUGH AIR WILL BE ABLE TO
WORK NORTHWARD AND ESPECIALLY INTO VALLEY LOCATIONS FOR SNOW TO
CHANGE TO RAIN WEDNESDAY MORNING…WITH RAIN CONTINUING THROUGH THE
DAY. EVEN FOR THE HIGHER TERRAIN SOUTH OF THE CAPITAL REGION WHERE
THERE WILL BE A COMPLEX MIX OF SNOW…SLEET…AND SOME POSSIBLE
FREEZING RAIN.
STEADY PRECIPITATION SHOULD CONTINUE THROUGH MUCH OF THE DAY…AS
THE SOUTHEASTERLY LOW LEVEL JET CONTINUES TO AID IN ATLANTIC
MOISTURE TRANSPORT. SNOW-LIQUID RATIOS WILL DECREASE SIGNIFICANTLY
FOR AREAS OUTSIDE THE HIGHEST ELEVATIONS…WHICH WILL LIMIT SNOW
ACCUMULATIONS STARTING LATE WEDNESDAY MORNING. THE RESULT IS A
RATHER COMPLICATED SNOWFALL FORECAST MAP WITH HIGHLY VARYING SNOW
ACCUMULATIONS…HEAVILY BASED ON ELEVATION AND TRANSITIONING
PRECIPITATION TYPES.
THE STRONGEST WINDS ACROSS THE ADVISORY AREA WILL START TO SUBSIDE
AROUND MID AFTERNOON…AS THE CORE OF THE LOW LEVEL JET SHIFTS NORTH
OF THE AREA.
SURFACE TEMPERATURES ARE EXPECTED TO RISE INTO THE UPPER 30S TO
AROUND 40 FOR MOST VALLEY LOCATIONS…WITH GENERALLY MID 30S OVER
THE HIGHER TERRAIN. THIS WILL MAKE FOR A RATHER WET SNOWFALL FOR
AREAS THAT RECEIVE ACCUMULATING SNOW.
THE SPRAWLING SYSTEM WILL BECOME VERTICALLY STACKED OVER WESTERN NEW
YORK WEDNESDAY NIGHT….WITH PRECIPITATION BECOMING MORE
INTERMITTENT AND LIGHTER AS THE FLOW TURNS MORE SOUTH-SOUTHWESTERLY
ALOFT WITH ATLANTIC MOISTURE FEED DIMINISHING. BOUNDARY LAYER
TEMPERATURES WILL CONTINUE TO SUPPORT RAIN IN THE LOWER ELEVATIONS
WEDNESDAY EVENING…WITH RAIN/SNOW IN THE HIGHER TERRAIN. SOME
COOLING ALOFT OVERNIGHT MAY ALLOW THE RAIN TO CHANGE BACK TO
SNOW/SLEET…BUT ANY ACCUMULATIONS WILL BE VERY LIGHT. A CHANGEOVER
TO PURE SNOW SHOULD OCCUR OVER THE HIGHER TERRAIN…WITH ADDITIONAL
LIGHT ACCUMULATIONS.
THE WINTER WEATHER HEADLINES EXPIRE BY SUNRISE THURSDAY
MORNING…ALTHOUGH LIGHT PRECIP WILL CONTINUE DURING THE DAY
THURSDAY THROUGH THURSDAY NIGHT. WITH LOW FILLING AND MEANDERING
EASTWARD ACROSS THE AREA IT WILL BE CONTINUED DREARY AND DAMP…WITH
OCCASIONAL HIGHER ELEVATION LIGHT SNOW AND LOWER ELEVATION RAIN.
WITH THE TRACK OF THE LOW MAINLY RIGHT OVER THE AREA…SURFACE
TEMPERATURES ARE AGAIN EXPECTED TO WARM TO WELL ABOVE FREEZING IN
VALLEY LOCATIONS ON THURSDAY WITH SLOW COOLING THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/…
THE LONG TERM PERIOD WILL BE DOMINATED BY A DRIER PERIOD TO START
OUT THE FIRST WEEK OF MARCH AS A BROAD UPPER-LEVEL TROUGH PERSISTS
ACROSS THE REGION.
AT THE START OF THE LONG TERM PERIOD…A BROAD UPPER-LEVEL TROUGH
WILL BE SITUATED ACROSS THE NORTHEAST…KEEPING CHANCES FOR
PRECIPITATION DURING THE DAY FRIDAY WITH MOSTLY CLOUDY SKIES…AS
SOME MOISTURE MAY BE THROWN BACK FAR ENOUGH WEST TO ALLOW FOR MAINLY
OROGRAPHICALLY-INDUCED SNOW SHOWERS IN THE HIGHER TERRAIN WITH
RAIN/SNOW SHOWERS IN VALLEY LOCATIONS. UNLIKE THE SYSTEM AFFECTING
THE SHORT TERM PERIOD…PRECIPITATION AMOUNTS LOOK TO BE LIGHT…BUT
A COUPLE OF INCHES OF SNOWFALL COULD FALL IN THE ADIRONDACKS AND
SOUTHERN GREENS.
AS THE UPPER-LEVEL LOW SLOWLY EXITS THROUGH THE WEEKEND…IT LOOKS
THAT MUCH OF THE FORECAST AREA WILL BE DRY BUT UNDER CONTINUED
MOSTLY CLOUDY SKIES.
DRY CONDITIONS LOOK TO CONTINUE INTO EARLY NEXT WEEK WITH WEAK HIGH
PRESSURE BUILDING IN THE LOW-LEVELS. HAVE CONFINED SLIGHT CHANCE
POPS TO THE ADIRONDACKS HOWEVER AS THE UPPER-LEVEL TROUGH THAT
SLOWLY EXITED THE REGION DURING THE WEEKEND MOLDS INTO MORE OF A
LONGWAVE TROUGH…RESULTING IN A BROAD RETROGRADING TROUGH ACROSS
THE EASTERN THIRD OF THE CONUS…WITH WEAK IMPULSES ROTATING DOWN
THROUGH SOUTHERN CANADA PROVIDING ENOUGH LIFT FOR SOME WIDELY
SCATTERED SNOW SHOWERS. THIS WEATHER PATTERN LOOKS TO PERSIST
THROUGH THE MIDDLE OF NEXT WEEK…BEFORE LONG RANGE GUIDANCE HINTS
AT SOME PACIFIC ENERGY KICKING THE LONGWAVE TROUGH OUT OF THE REGION.
TEMPERATURES THROUGH THE LONG TERM PERIOD WILL BE NEAR NORMAL WITH
GENERALLY IN THE UPPER 20S TO UPPER 30S AND LOWS IN THE SINGLE
DIGITS/TEENS IN HIGHER TERRAIN TO LOWER 20S IN THE HUDSON VALLEY.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/…
A COMPLEX STORM SYSTEM WILL IMPACT THE REGION TONIGHT THROUGH
WEDNESDAY…AS HIGH PRESSURE MOVES EAST OF THE REGION THIS AFTERNOON.
VFR CONDITIONS ARE EXPECTED PRIOR TO MIDNIGHT…AS CLOUDS THICKEN
AND LOWER THIS EVENING. SOME STRATUS BTWN 3.5-4.5 KFT WILL
CONTINUE TO DRIFT IN OVER THE REGION BENEATH THE HIGH CLOUDS.
A STRATUS DECK SHOULD FORM ALONG THE LEADING EDGE OF THE WARM
ADVECTION PCPN LATER THIS EVENING. THE THERMAL ADVECTION PCPN
ARRIVES AHEAD OF A SECONDARY LOW PRESSURE SYSTEM BTWN 05Z-09Z FROM
SOUTH TO NORTH ACROSS THE REGION. THE INITIAL SURGE OF PCPN MAY
COOL THE COLUMN DOWN FOR SNOW AT KPOU/KALB/KPSF/KGFL. EXPECT
WIDESPREAD IFR/LIFR CONDITIONS TO IMPACT THE TERMINALS IN THE
SNOW. THE GFS/NAM MODEL SOUNDINGS INDICATE A RAPID TRANSITION TO
RAIN AT KPOU BTWN 07Z- 10Z…THEN NORTH TO KALB BY 13Z. WE
FOLLOWED CLOSE TO THIS TREND IN THE TAFS THERE. KPSF AND KGFL ARE
EXPECTED TO HAVE A MIXTURE OF RAIN AND SNOW BY THE LATE MORNING.
WIDESPREAD IFR CIGS/VSBYS ARE EXPECTED IN RAIN THROUGH THE
AFTERNOON AT ALL THE SITES.
THE WINDS WILL BE SE TO NE AT 5-10 KTS OVERNIGHT INTO WED
MORNING. THE LOW-LEVEL JET AT 2 KFT AGL WILL INCREASE FROM THE
E/SE AT 40-50 KTS AT POU TO KPSF BTWN 07Z-09Z. LLWS GROUPS WERE
ADDED FROM THAT TIME UNTIL 16Z/WED. KALB IS A LITTLE UNCERTAIN IN
THE IMPACT OF ANY WIND SHEAR…SO WE WILL CONTINUE TO MONITOR.
HOWEVER…A WIND SHEAR GROUP WAS ADDED AT KGFL IN THE LATE
MORNING.
OUTLOOK…
WED…MVFR/IFR. PERIODS OF RAIN.
WED NIGHT…MVFR/IFR. RAIN/SNOW LIKELY
MAINLY IN THE EVENING.
THU-FRI…VFR/MVFR. CHC -SHSN/-SHRA.
SAT-SUN…VFR. NO SIG WX.
&&
.HYDROLOGY…
A SLOW MOVING STORM SYSTEM IS EXPECTED TO BRING A HALF TO GREATER
THAN AN INCH OF LIQUID EQUIVALENT QPF TO THE AREA WITH SNOW…RAIN
AND OR MIXED PRECIPITATION. THE BEST CHANCE FOR RAIN WILL BE IN
VALLEY LOCATIONS WEDNESDAY INTO WEDNESDAY NIGHT. TEMPERATURES ARE
ONLY EXPECTED RISE INTO THE UPPER 30S TO LOWER 40S FOR HIGHS ON
WEDNESDAY…SO EVEN WHERE IT RAINS SNOW MELT AND RUNOFF WILL NOT BE
EXTREME. THERE COULD BE SOME MINOR FLOODING OF POOR DRAINAGE
LOCATIONS…ESPECIALLY WITH FROZEN GROUND. OTHERWISE…MOST AREAS
WITH A SNOW PACK WILL EITHER SEE THE SNOW PACK GROW OR WILL HAVE
RAIN/MIXED PRECIP SOAK IN WITH TEMPERATURES MAINLY IN THE 30S. SO
RUNOFF WILL GENERALLY BE LIMITED TO THE SOUTHEAST HALF OF THE AREA.
THE HEAVIEST QPF IS EXPECTED OVER THE HIGHER TERRAIN…ESPECIALLY
EAST-SOUTHEAST FACING SLOPES/FOOTHILLS…ALTHOUGH THE MAJORITY OF
THE PRECIP SHOULD FALL AS A MIX INCLUDING SNOW WHICH WILL LIMIT
RUNOFF POTENTIAL THERE.
PRECIPITATION COULD CHANGE BACK TO SNOW OR SLEET LATE WEDNESDAY
NIGHT INTO THURSDAY MORNING AS THE STORM SYSTEM SLOWLY DRIFTS
EASTWARD ACROSS THE AREA…BUT COULD CHANGE BACK TO RAIN IN VALLEY
LOCATIONS BY THURSDAY AFTERNOON AS SURFACE TEMPERATURES WARM. LIGHT
RAIN/SNOW COULD LINGER INTO FRIDAY.
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…WINTER WEATHER ADVISORY UNTIL 6 AM EST THURSDAY FOR NYZ032-
038>041-047-048-051-083.
WINTER STORM WARNING UNTIL 6 AM EST THURSDAY FOR NYZ033-042-
058-063-082.
WIND ADVISORY FROM 5 AM TO 3 PM EST WEDNESDAY FOR NYZ054.
MA…WINTER WEATHER ADVISORY UNTIL 6 AM EST THURSDAY FOR MAZ025.
WINTER STORM WARNING UNTIL 6 AM EST THURSDAY FOR MAZ001.
WIND ADVISORY FROM 5 AM TO 3 PM EST WEDNESDAY FOR MAZ001.
VT…WINTER STORM WARNING UNTIL 6 AM EST THURSDAY FOR VTZ013>015.
WIND ADVISORY FROM 5 AM TO 3 PM EST WEDNESDAY FOR VTZ013-014.
&&
$$
SYNOPSIS…IRL/NAS/JPV
NEAR TERM…NAS/JPV
SHORT TERM…JPV
LONG TERM…IRL
AVIATION…WASULA
HYDROLOGY…JPV
