February 6, 2013 Forecast Discussion

000
FXUS61 KALY 062350
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
650 PM EST WED FEB 6 2013

.SYNOPSIS…
HIGH PRESSURE OVER SOUTHERN CANADA WILL ALLOW FOR A
CLEAR AND COLD NIGHT TONIGHT. ALTHOUGH TOMORROW WILL BE DRY…SOME
LIGHT SNOW IS LIKELY TO BEGIN LATE TOMORROW NIGHT AS A UPPER LEVEL
TROUGH APPROACHES FROM THE WEST. A WIDESPREAD HEAVY SNOWFALL IS
EXPECTED FRIDAY AND FRIDAY NIGHT AS A STRONG LOW PRESSURE SYSTEM
DEVELOPS ALONG THE MID ATLANTIC COAST AND MOVES NORTHEAST.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/…
AS OF 645 PM EST…A STRONG AREA OF HIGH PRESSURE /AROUND
1035-1038 HPA/ OVER SOUTHERN CANADA WILL NOSE INTO THE REGION
OVERNIGHT. THIS WILL ALLOW SKIES TO CLEAR OUT AND WINDS TO BECOME
LIGHT ACROSS THE ENTIRE AREA…ALTHOUGH WINDS SHOULD REMAIN BRISK
ACROSS THE MOHAWK VALLEY/CAPITAL REGION AND BERKSHIRES THROUGH
THIS EVENING. GOOD RADIATIONAL COOLING WITH TAKE PLACE…ALLOWING
FOR A VERY COLD NIGHT…ESP IN AREAS THAT STILL HAVE A SNOW PACK.
OVERNIGHT LOWS WILL RANGE FROM NEARLY -20 DEGREES IN THE
ADIRONDACKS TO AROUND 10 IN THE POUGHKEEPSIE AREA. TEMPS IN THE
CAPITAL REGION WILL BE RIGHT AROUND ZERO TO 5 F.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/…

…WINTER STORM TO IMPACT THE REGION FRIDAY INTO FRIDAY NIGHT…

A WINTER STORM WATCH HAS BEEN EXPANDED TO INCLUDE THE ENTIRE
FORECAST AREA FOR THE POTENTIAL FOR HEAVY SNOWFALL FOR FRIDAY INTO
FRIDAY NIGHT.

HIGH PRESSURE WILL SLIDE TO THE EAST DURING THE DAY ON THURSDAY.
ALTHOUGH THE DAY WILL START OFF COLD AND DRY WITH CLEAR
SKIES…MID AND HIGH LEVEL CLOUDS WILL INCREASE DURING THE DAY. A
FEW SNOW SHOWERS ARE POSSIBLE ACROSS THE WESTERN ADIRONDACKS BY
LATE IN THE DAY AS A WARM FRONT ASSOCIATED WITH AN APPROACHING
NORTHERN STREAM SYSTEM. MAX TEMPS ON THURSDAY WILL BE
CHILLY…WITH TEENS TO 20S ACROSS THE AREA.

ON THURSDAY NIGHT…THE CHANCE FOR PRECIPITATION WILL INCREASE AS
THE NORTHERN STREAM SYSTEM HEADS TOWARDS THE EASTERN GREAT LAKES.
AT THE SAME TIME…A SOUTHERN STREAM SYSTEM WILL BE MOVING UP THE
CAROLINA COASTLINE. SOME WARM ADVECTION LIGHT SNOW IS POSSIBLE
DURING THE OVERNIGHT HOURS…ALTHOUGH THE BEST CHC WON/T BE UNTIL
LATE THURSDAY NIGHT INTO FRIDAY MORNING. WITH THE INCREASING
AMOUNTS OF CLOUDS AND POSSIBLE PRECIP…MIN TEMPS WON/T BE AS COLD
THURSDAY NIGHT…WITH TEENS ACROSS MUCH OF THE AREA.

ON FRIDAY…THE SOUTHERN STREAM SYSTEM WILL BECOME THE DOMINATE
LOW…AS THE TWO SYSTEMS PHASE DURING THE DAY. THE SYSTEM WILL
UNDERGO RAPIDLY CYCLOGENESIS AND QUICKLY DEEPEN. THE CLOSING OFF
OF THE HPA 500 LOW WILL ALSO SLOW THE SYSTEM DOWN SOMEWHAT…ESP
DURING FRIDAY NIGHT.

WE WILL START TO SEE WARM ADVECTION PRECIP ACROSS OUR AREA DURING
THE DAY FRIDAY WELL OUT AHEAD OF THE DEVELOPING STORM OFF THE
DELMARVA AND THE APPROACHING LOW ACROSS THE EASTERN GREAT LAKES.
HOWEVER…THIS PRECIP LOOKS MAINLY LIGHT…AS THE HEAVIEST WARM
ADVECTION MAY ACTUALLY WIND UP NORTHWEST OF OUR AREA. SNOWFALL
RATES WON/T BE TOO HIGH DURING THE DAY ON FRIDAY. HOWEVER…THE
SNOW WILL BECOME MORE STEADY BY LATE AFTERNOON AS THE STORMS
PHASES…BUT ONLY A FEW INCHES OF SNOWFALL WILL LIKELY OCCUR
THROUGH FRIDAY AFTERNOON.

THE REAL HEAVY ACCUMULATING SNOW WILL GET GOING ON FRIDAY
EVENING…AS THE STORM CONTINUES TO DEEPEN OFF THE NJ SHORE TO THE
SOUTH OF LONG ISLAND. THE DETERMINISTIC GFS/GGEM/ECWMF AND GEFS
ALL SHOW A POWERFUL 850 HPA JET IN PLACE…TRANSPORTING PLENTY OF
ATLANTIC MOISTURE INTO OUR AREA. THE 12Z GEFS SHOW 850 HPA U WIND
ANOMALIES OF 2 TO 5 STD BELOW NORMAL. THIS SUGGESTS A SIGNIFICANTLY
STRONG FLOW INTO OUR AREA. MOST DETERMINISTIC GUIDANCE…AS WELL
AS THE 12Z GEFS MEAN…SHOW AROUND 1.00 INCH OF LIQUID EQUIVALENT
ACROSS MUCH OF OUR AREA…WITH SOME HIGHER AMOUNTS ACROSS THE HIGH
TERRAIN AND WESTERN NEW ENGLAND. THE 12Z NAM WAS DISCOUNTED…AS
IT SEEMS TO GO A LITTLE TOO NUTS WITH THE QPF…ESP ACROSS NEW
ENGLAND. THE 18Z NAM SEEM TO FIT BETTER WITH THE OTHER
DETERMINISTIC GUIDANCE.

AS A RESULT…SNOW RATES ON FRIDAY EVENING CAN EASILY EXCEED ONE
INCH PER HOUR…AND MAY REACH TWO INCHES PER HOUR AT TIMES…ESP
ACROSS WESTERN NEW ENGLAND…WHERE SOME MESOSCALE SNOW BANDING
WILL BE POSSIBLE. WINDS MAY ALSO START TO PICK UP /A FEW GUSTS OF
20-40 MPH/ ACROSS OUR HIGH TERRAIN EASTERN AREAS ON FRIDAY NIGHT
AS THE STORM DEEPENS…ALTHOUGH THE BEST GUSTS LOOK TO REMAIN
ALONG THE COAST TO THE EAST OF OUR AREA.

THE SNOW WILL BEGIN TO WIND DOWN TOWARDS DAYBREAK SATURDAY…AS
THE STORM WINDS UP JUST EAST OF NANTUCKET. AT LEAST 9 INCHES LOOKS
POSSIBLE ACROSS OUR ENTIRE AREA…WHICH IS WHY THE WATCH HAS BEEN
POSTED FOR OUR ENTIRE AREA. HIGH TERRAIN OF BERKSHIRE/LITCHFIELD
COUNTY MAY SEE THE HIGHEST AMOUNTS…WITH AROUND A FOOT AND A HALF
POSSIBLE IN THESE AREAS.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/…
SATURDAY…LATEST 12Z/06 ECMWF CONTINUES TO BE MUCH SLOWER THAN
OTHER GLOBAL MODELS AND THEIR ENSEMBLE SUITES. WILL HEDGE A BIT
FASTER THAN THIS…BUT STILL KEEP SOME LIKELY POPS THROUGH SAT AM
ACROSS EASTERN AREAS…WITH CHC POPS ELSEWHERE…TAPERING TO SLIGHT
CHC BY LATE IN THE DAY IN ALL AREAS. ADDITIONAL LIGHT TO MODERATE
ACCUMS COULD OCCUR ACROSS EXTREME EASTERN AREAS SAT AM…WITH
PERHAPS MINOR ACCUMS ELSEWHERE. OTHERWISE…EXPECT WINDY
CONDITIONS…WITH GRADUAL LATE DAY CLEARING. SOME AREAS OF
BLOWING/DRIFTING OF SNOW WILL LIKELY OCCUR THROUGHOUT THE DAY. FOR
MAX TEMPS…EXPECT MAINLY LOWER/MID 20S WITHIN MUCH OF THE HUDSON
RIVER VALLEY…WITH TEENS ACROSS HIGHER ELEVATIONS AND NORTHERN
AREAS.

SAT NT…GIVEN THE EXPECTATION OF A DEEP SNOWPACK ACROSS MUCH OF THE
REGION…AND A RIDGE OF HIGH PRESSURE SLOWLY CRESTING
OVERHEAD…EXPECT VERY COLD TEMPS LATE SAT NT/EARLY SUN AM. HAVE
UNDERCUT ALL GUIDANCE…WITH WIDESPREAD SINGLE DIGITS ABOVE AND
BELOW ZERO…WITH SOME MINS FALLING INTO THE -10 TO -15 RANGE ACROSS
PORTIONS OF THE ADIRONDACKS. WINDS SHOULD BE DECREASING…SO NOT
ANTICIPATING WIND CHILL ISSUES AT THIS TIME.

SUNDAY-SUNDAY NIGHT…HIGH PRESSURE RIDGE SLIDES BY…AND EVENTUALLY
EAST OF REGION. THIS SHOULD BRING GENERALLY SUNNY SKIES FOR
SUNDAY…WITH CLEAR SKIES INITIALLY SUNDAY EVENING…THEN FOLLOWED
BY INCREASING CLOUDS LATE SUNDAY NIGHT IN ADVANCE OF A SURGE OF MID
LEVEL WARM ADVECTION AHEAD OF NEXT SYSTEM APPROACHING FROM THE WEST.
FOR TEMPS…AGAIN HAVE UNDERCUT MOST MOS…WITH SUNDAY MAX TEMPS
ONLY REACHING THE MID/UPPER 20S IN MOST AREAS…EXCEPT FOR SOME
LOWER 30S ACROSS PORTIONS OF THE MID HUDSON VALLEY REGION AND LOWER
ELEVATIONS IN NW CT. MIN TEMPS FOR SUN NT/MON AM SHOULD BE
EARLY…WITH WIDESPREAD SINGLE DIGITS AND LOWER TEENS. TEMPS MAY
RISE LATER AT NIGHT AS CLOUDS INCREASE…AND WINDS SHIFT INTO THE
SOUTH.

MON-MON NT…AS SYSTEM APPROACHES FROM GREAT LAKES REGION…STRONG
MID LEVEL WARM ADVECTION WILL LEAD TO CLOUDS AND
PRECIPITATION…PROBABLY STARTING MONDAY MORNING. THERMAL PROFILES
SUGGEST PRECIP SHOULD START AS SNOW…THEN MAY TRANSITION TO A
WINTRY MIX OF SLEET/FREEZING RAIN AND RAIN MON AFTERNOON AND
EVENING…BEFORE CHANGING BACK TO SNOW SHOWERS LATE MON NT/EARLY TUE
AS MID LEVEL COOL ONCE AGAIN. WILL INCLUDE CHC POPS…AND ALSO
MENTION IN HWOALY FOR CHC OF FREEZING RAIN FOR MON. HAVE UNDERCUT
MEX MOS FOR MONDAY MAXES…WITH WIDESPREAD 30S EXPECTED…POSSIBLY
BRIEFLY APPROACHING 40 ACROSS PORTIONS OF THE MID HUDSON VALLEY
REGION. MON NT MINS SHOULD FALL INTO THE 20S TO LOWER 30S BY
DAYBREAK TUE.

TUE-WED…EXPECT MAINLY FAIR CONDITIONS…ALTHOUGH SOME LINGERING
SNOW SHOWERS AND/OR LAKE EFFECT COULD OCCUR TUE. TUE MAX TEMPS
SHOULD REACH THE 30S TO LOWER 40S TUE…THEN TEENS AND 20S FOR TUE
NT/WED. FOR WED…EXPECT MAXES TO ONLY REACH THE 30S IN MOST AREAS.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/…
HIGH PRESSURE WILL DOMINATE THE LOCAL WEATHER AHEAD OF AN
APPROACHING POWERFUL STORM SYSTEM THROUGH THURSDAY.

TONIGHT INTO THURSDAY…SKIES WILL REMAIN CLEAR THROUGH THIS EVENING
BEFORE SOME HIGH AND MID LEVEL CLOUDS GRADUALLY FILTER IN FROM
THE WEST AHEAD OF AN APPROACHING POWERFUL STORM SYSTEM. MID LEVEL
CLOUDS WILL CONTINUE TO THICKEN DURING THE DAY THURSDAY AS UPPER-
LEVEL MOISTURE INCREASES AHEAD OF THE SYSTEM.

WEST TO NORTHWEST WINDS OF 8-12 KT…AND SOME GUSTS OF 15-25 KT
WILL REMAIN POSSIBLE AT KALB AND KPSF THROUGH AROUND 04Z/THU…BEFORE
BECOMING LIGHT AND VARIABLE. ELSEWHERE…WINDS WILL BE LIGHT AND
VARIABLE GENERALLY LESS THAN 7 KNOTS THROUGH 00Z/FRI.

OUTLOOK…
THU NGT-FRI NIGHT. MVFR/IFR WITH SNOW POSSIBLY HEAVY AT TIMES.
SAT…MVFR/IFR BECOMING VFR…CHC -SN IN MORNING. WINDY.
SAT NIGHT-SUN NT…VFR…NO SIG WX.
MON…CHC -SN/-PL/-FZRA CHANGING TO -RA.

&&

.HYDROLOGY…
WIDESPREAD HYDRO PROBLEMS ARE NOT ANTICIPATED OVER THE NEXT FEW
DAYS AS OUR COLD WEATHER CONTINUES WITH ANY PRECIPITATION IN THE
FORM OF SNOW.

SOME RIVER AND STREAM GAGES ARE EXPERIENCING ICE EFFECTS. ICE
WILL CONTINUE TO FORM AND THICKEN ON ALL BODIES OF WATER.

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 STORM WATCH FROM FRIDAY MORNING THROUGH LATE FRIDAY
NIGHT FOR CTZ001-013.
NY…WINTER STORM WATCH FROM FRIDAY MORNING THROUGH LATE FRIDAY
NIGHT FOR NYZ032-033-038>043-047>054-058>061-063>066-
082>084.
MA…WINTER STORM WATCH FROM FRIDAY MORNING THROUGH LATE FRIDAY
NIGHT FOR MAZ001-025.
VT…WINTER STORM WATCH FROM FRIDAY MORNING THROUGH LATE FRIDAY
NIGHT FOR VTZ013>015.

&&

$$
SYNOPSIS…FRUGIS
NEAR TERM…KL/FRUGIS
SHORT TERM…FRUGIS
LONG TERM…KL
AVIATION…KL/IRL
HYDROLOGY…FRUGIS/GJM

Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-ShareAlike 3.0 License