000
FXUS61 KALY 260017
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
718 PM EST TUE FEB 25 2014
.SYNOPSIS…
A CLIPPER LOW WILL APPROACH THE REGION TONIGHT FROM THE NORTHERN
GREAT LAKES REGION AND SOUTHEAST ONTARIO. IT WILL BRING SNOW
SHOWERS TO THE REGION TOMORROW…AS IT MOVE ACROSS SOUTHERN QUEBEC
…WITH A REINFORCING SHOT OF ARCTIC AIR THEREAFTER. ANOTHER
CLIPPER WILL BRING A CHANCE OF SNOW SHOWERS ON THURSDAY WITH SOME
BITTERLY COLD AIR FOR EASTERN NEW YORK AND WESTERN NEW ENGLAND
THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/…
AS OF 700 PM…WINDS AND SCATTERED SNOW SHOWERS WERE DIMINISHING
ACROSS THE REGION WITH THE LOSS OF DIURNAL HEATING. PREVIOUS
FORECAST WAS IN GOOD SHAPE AND HAVE ONLY MADE SOME MINOR ADJUSTMENTS
TO THE HOURLY TEMP/DEWPOINT GRIDS.
.PREVIOUS DISCUSSION…
AS OF 358 PM EST…THE NORTHEAST CONTINUES TO BE UNDER THE
INFLUENCE OF A BROAD MID AND UPPER LEVEL TROUGH TODAY INTO THE
MIDDLE AND LATTER PORTIONS OF THE WEEK. A WEAK MID LEVEL VORT MAX
HAS KICKED OFF SOME DIFFUSE AND CELLULAR SNOW SHOWERS AND FLURRIES
ACROSS THE FCST AREA THIS AFTERNOON. MOST OF THESE SNOW SHOWERS
WILL PRODUCE LITTLE OR NO ACCUMULATIONS…OR A COATING TO A FEW
TENTHS OF AN INCH AT BEST. THE STEEP LOW AND MID LEVEL LAPSE RATES
DUE TO THE COLD POOL ALOFT HAVE ALLOWED THESE CELLULAR SNOW
SHOWERS AND FLURRIES TO FORM…AND THEY SHOULD DIMINISH TOWARDS
SUNSET.
THE ATTENTION NEXT SHIFTS TO THE CLIPPER LOW APPROACHING FROM SRN
ONTARIO…AND LAKE SUPERIOR THIS AFTERNOON. IT WILL CONTINUE TO
QUICKLY MOVE TO THE E/NE TONIGHT AND WILL BE NEAR THE SE
ONTARIO…AND NRN NY BORDER BY DAYBREAK TOMORROW. THEIR WILL BE
WEAK WARM ADVECTION AHEAD OF THE CLIPPER…AS THE LOW LEVEL FLOW
BACKS TO THE SOUTHWEST. SOME LAKE ONTARIO LOW-LEVEL MOISTURE WILL
BE UTILIZED…AND THE CHANCES OF SNOW SHOWERS/LIGHT SNOW INCREASE
SHORTLY BEFORE MIDNIGHT OVER THE SRN DACKS REGION…AND THEN
SPREAD E/SE GRADUALLY OVER THE REST OF THE FCST AREA. THE BEST QG
LIFT…AND LOW-LEVEL CONVERGENCE WILL BE NEAR THE CLIPPER CYCLONE.
SOME OROGRAPHIC ENHANCEMENT MAY OCCUR OVER THE WRN DACKS. THE GFS
INDICATES THE BEST BURST OF LAKE ENHANCED SNOWFALL WILL BE OVER
HERKIMER/HAMILTON COUNTIES WITH AN INCH OR TWO OVERNIGHT. POPS
WERE INCREASED TO HIGH CHC AND LIKELY VALUES THERE PRIOR TO
DAYBREAK WITH CHC AND SLIGHT CHC VALUES FURTHER DOWNSTREAM OVER
THE REST OF THE FCST AREA. DUSTINGS TO A QUARTER OF AN INCH OF
SNOW ARE EXPECTED IN MOST OTHER LOCATIONS.
THE SKIES WILL PARTIALLY CLEAR EARLY THIS EVENING…THEN INCREASE
QUICKLY AHEAD OF THE CLIPPER AND THE SFC CYCLONE PASSING EAST OF
THE CAROLINAS. LOWS WILL BE IN THE LOWER TO MID TEENS FROM THE
CAPITAL DISTRICT SOUTH AND EAST…AND SINGLE DIGITS TO THE NORTH
AND WEST…AND OVER THE ERN CATSKILLS…AND BERKSHIRES.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/…
TOMORROW…THE CLIPPER MOVES N/NE OVER SE QUEBEC BY THE EARLY
AFTERNOON…AND THE COLD/ARCTIC FRONT TO SYSTEM SWINGS ACROSS THE
REGION WITH SCT SNOW SHOWERS AND PERHAPS AN ISOLD SNOW SQUALL IN
THE LATE MORNING INTO THE EARLY PM. STRONG CONVERGENCE WITH THE
BOUNDARY WILL PROMOTE THE EMBEDDED HEAVIER SNOW SHOWERS AND
PERHAPS SQUALLS. THE LATEST HIRESWRF LAYER COMPOSITE REF PRODUCT
SHOWS THE BEST SNOW SHOWERS OF 20+ DBZ IMPACTING THE
TACONICS…WRN NEW ENGLAND AND THE MID HUDSON VALLEY IN THE 1500
UTC TO 1700 UTC TIME FRAME. SNOW ACCUMULATIONS WITH THE ARCTIC
FRONT WILL RANGE FROM A COATING TO AN INCH WITH LOCALIZED HIGHER
AMOUNTS OF A FEW INCHES. THE H850 TEMPS CRASH AGAIN TO -19C TO
-23C OVER THE FCST AREA BY THE LATE PM. IT WILL ALSO BECOME WINDY
IN THE WAKE OF THE FRONT WITH UPSLOPE SNOW SHOWERS POSSIBLE OVER
THE TACONICS…BERKSHIRES…AND SRN GREENS. THE LAKE EFFECT
EXTENSION INTO THE WRN DACKS LOOKS LIKE IT WILL BE LIMITED BY
DRIER AIR FILTERING IN…AND A LOWERING INVERSION BY NIGHTFALL.
SNOW ACCUMULATIONS OF 2-4 INCHES ARE EXPECTED TUE NIGHT THRU WED
FOR NRN HERKIMER AND PARTS OF HAMILTON COUNTY. LESS THAN AN INCH
IN THE HUDSON RIVER VALLEY…CT RIVER VALLEY…CNTRL-SRN
TACONICS…AND NW CT…AND 1-2 INCHES IN MOST OTHER LOCATIONS. A
BLEND OF THE NAM MOS AND GFS MOS MAX TEMPS WERE USED WITH A
SHADING CLOSER TO THE COLDER NAM MOS NUMBERS WITH HIGHS IN THE
TEENS OVER THE SRN DACKS…WRN MOHAWK VALLEY…SRN GREENS AND
PARTS OF THE CATSKILLS…AND LOWER TO MID 20S AND MOST OTHER
LOCATIONS.
WED NIGHT…THE BLUSTERY W/NW WINDS WILL LIKELY DIMINISH PRIOR TO
MIDNIGHT…AS A MICRO RIDGE OF SFC HIGH PRESSURE BUILDS IN FROM THE
SOUTH AHEAD OF THE NEXT CLIPPER QUICKLY APPROACHING FROM SE ONTARIO
AND THE ERN GREAT LAKES REGION. WIND CHILLS/APPARENT TEMPS JUST
FALL SHORT OF ADVISORY LEVELS OVER THE SRN DACKS REGION. LOWS WILL
BE IN THE SINGLE DIGITS…EXCEPT SOME ZERO TO 5 BELOW READINGS
OVER THE SRN DACKS…LAKE GEORGE REGION…AND SRN GREENS. THE
THREAT FOR SOME LIGHT SNOW OR SNOW SHOWERS INCREASES OVER THE WRN
DACKS PRIOR TO SUNRISE.
THU-THU NIGHT….CLIPPER NUMBER TWO IN AS MANY DAYS IMPACTS THE
REGION WITH A ROUND OF SNOW SHOWERS/LIGHT SNOW. THE ARCTIC FRONT
WITH THIS CLIPPER LOOKS EVEN STRONGER THAN ITS PREDECESSOR. THIS
CLIPPER DIVES A LITTLE FURTHER SOUTH OVER NRN NEW ENGLAND…AND THEN
INTO THE GULF OF MAINE. THE BEST MOISTURE CONVERGENCE LOOKS LIKE IT
WILL BE OVER THE WRN DACKS AGAIN…WHERE A FEW INCHES OF SNOW LOOK
LIKELY. MOST OTHER LOCATIONS WILL RECEIVE A DUSTING TO AN INCH. THE
WIND FIELDS STRENGTHEN IN THE WAKE OF THE CLIPPER WITH SW WINDS
SHIFTING TO THE WEST WITH THE FRONTAL PASSAGE IN THE AFTERNOON. WEST
WINDS OF 15 TO 25 MPH WITH SOME GUSTS TO 35 TO 40 MPH WILL BE
POSSIBLE DUE TO FUNNELING DOWN THE MOHAWK VALLEY INTO THE CAPITAL
REGION INTO THE CNTRL TACONICS…AND BERKSHIRES. THESE GUSTY WINDS
ARE ALSO EXPECTED IN THE ERN AND NRN CATSKILLS. HIGHS WILL GENERALLY
BE IN THE TEENS TO M20S WITH A FEW U20S IN THE MID HUDSON
VALLEY…AND NW CT. THE GFS HAS H850 TEMPS FALL TO -21C TO -26C OVER
THE ERN NY AND WRN NEW ENGLAND. THESE H850 TEMPS ARE 2 TO 3 STANDARD
DEVIATIONS COLDER THAN NORMAL BASED ON THE LATEST GEFS. LOWS WILL BE
ZERO TO 5 ABOVE FROM THE CAPITAL REGION SOUTH AND EAST…AND ZERO TO
10 BELOW TO THE NORTH AND WEST…WITH A FEW 10 TO 15 BELOW READINGS
OVER THE SRN DACKS. WIND CHILLS MAY HIT ADVISORY CRITERIA OVER THE
HIGHER TERRAIN. WE WILL CONTINUE TO MENTION IN THE HWO.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/…
WELL BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE LONG TERM
PORTION OF THE FORECAST.
A LARGE LOW PRESSURE WILL RESIDE OVER EASTERN CANADA (POLAR
VORTEX)…WITH AN ANOMALOUS AND ELONGATED RIDGE ANCHORED OVER THE
WESTERN CONUS…EXTENDED NORTHWARD TO ALASKA…TO CONTINUE TO SHIP A
SLEW OF ARCTIC AIR INTO MIDWEST AND EASTERN USA. THE POLAR VORTEX
WILL LIFT NORTH AND WEAKEN A LITTLE BY LATE IN THE WEEKEND.
HIGH PRESSURE ON FRIDAY WILL PROVIDE PLENTY OF SUNSHINE TO THE
REGION ALONG WITH A BITING BREEZE.
THEN…A CLIPPER ON SATURDAY LOOKS TO BRING LIGHT SNOW OR SNOW
SHOWERS TO MAINLY THE CAPITAL REGION ON NORTHWARD.
THIS CLIPPER MOVES ON BY…FOLLOWED BY ANOTHER ARCTIC AIR MASS
DROPPING H850 TEMPS BACK DOWN TO AS LOW AS AROUND -25C BY SUNDAY
MORNING! THERE WILL BE SOME WIND TO GO ALONG WITH IT…AS LOW
PRESSURE DEEPENS AS IT ENTERS THE GULF OF MAINE.
BY SUNDAY NIGHT…AS THE AFOREMENTIONED POLAR VORTEX LIFTS NORTH AND
WEAKENS A LITTLE…ATTENTION TURNS TO THE SOUTHERN JETSTREAM. UP
UNTIL THIS POINT…THIS HAS BEEN HELD WELL TO OUR SOUTH. BY
SUNDAY NIGHT…A STRONG BAROCLINIC ZONE WILL BE SETTING UP TO OUR
SOUTH AND IT LOOKS AS IF A STORM…OR A SERIES OF STORMS WILL RIDE
ALONG WITH BAROCLINIC ZONE SUNDAY NIGHT POSSIBLY INTO TUESDAY.
THE 12Z GFS OPERATIONAL MODEL KEPT MUCH OF THE MOISTURE WITH A LOW
PRESSURE TO THE SOUTH OF ALBANY WHILE THE GFS ENSEMBLE TRACKED IT
LITTLE NORTH. THE 12Z EUROPEAN MODEL HAS TRENDED A LITTLE FURTHER
SOUTH WITH A MILLER-B TYPE STORM AS WELL…TRACKING IT OFF THE
DELMARVA PENINSULA.
IT IS WAY TOO EARLY TO DETERMINE ANY MEANINGFUL TRENDS…BUT THE
SIGNALS ARE THERE FOR YET ANOTHER POTENTIAL SNOWSTORM FROM LATE
SUNDAY NIGHT INTO EARLY TUESDAY. WE WILL ADDRESS THIS POSSIBILITY IN
OUR HAZARDOUS WEATHER OUTLOOK (HWO) FOR NOW. WE ASSIGNED 30-50 SNOW
POPS SUNDAY NIGHT…50 SNOW POPS EVERYWHERE FOR MONDAY.
SNOW SHOWERS COULD LINGER BEHIND THE SOUTHERN STORM LIKELY THE
RESULT OF YET ANOTHER ARCTIC FRONT COMING IN ON THE HEELS OF THE
STORM FOR LATE MONDAY INTO TUESDAY.
LOOK FOR HIGH TEMPERATURES GENERALLY IN THE 20S SOUTH/TEENS NORTH
THROUGHOUT THE PERIOD…POSSIBLY POPPING INTO THE LOWER 30S SOUTH OF
ALBANY SATURDAY AS WE DO PICK UP A BRIEF SOUTHERLY BREEZE AHEAD OF
THE ARCTIC COLD FRONT. OVERNIGHT LOWS WILL GENERALLY AVERAGE -10 TO
AROUND ZERO NORTH…5 TO 15 SOUTH. THESE VALUES WILL BE CLOSE TO 10
DEGREES COLDER THAN NORMAL.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/…
MAINLY VFR FLIGHT CONDITIONS WILL PREVAIL THROUGHOUT THE TAF PERIOD
ENDING AT 00Z THURSDAY AT THE KGFL/KALB/KPOU/KPSF TAF SITES.
WINDS HAVE DIMINISHED TO 10 KTS OR LESS AT THE TAF SITES TO START
THE TAF PERIOD…ALONG WITH THE CLOUDS AND SCT SNOW SHOWERS. HAVE
KEPT VCSH IN THE KALB/KGFL/KPSF TAF SITES THROUGH AROUND 03Z/04Z
WITH MAINLY BKN CLOUD COVER. MAINLY CLEAR SKIES THEREAFTER BUT SKIES
WILL BECOME BKN AGAIN AFTER AROUND 10Z AS AN ARCTIC COLD FRONT
ASSOCIATED WITH A CLIPPER SYSTEM APPROACHES FROM THE WEST. ONCE
AGAIN THIS SYSTEM LOOKS MOISTURE STARVED…SO FOR NOW HAVE ONLY
RE-INTRODUCED VCSH ALONG WITH VFR CIGS BETWEEN 10Z/11Z AND 14Z/15Z.
AT THIS POINT THE THREAT FOR MVFR CONDITIONS WAS UNDER 50 PERCENT…
AND THREAT OF IFR CIGS/VSBY DUE TO SNOW SHOWERS LOOKS VERY LOW
(UNDER 25 PERCENT).
AS USUAL…IF FLYING LATER TONIGHT OR TOMORROW MORNING…WE
ENCOURAGE YOU TO CHECK BACK FOR ANY UPDATES REGARDING THE AVIATION
DISCUSSION AND TAFS.
OUTLOOK…
WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: MODERATE OPERATIONAL IMPACT.WINDY. CHANCE OF SHSN.
THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT.WINDY. NO SIG WX.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. NO SIG WX.
SATURDAY:MODERATE OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
SUNDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
&&
.HYDROLOGY…
NO HYDRO IMPACTS ARE EXPECTED ON THE MAIN STEM RIVERS THE NEXT 5
DAYS. 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 FROM
CLIPPER LOWS OR LAKE EFFECT.
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…NONE.
MA…NONE.
VT…NONE.
&&
$$
SYNOPSIS…11/WASULA
NEAR TERM…GJM/WASULA
SHORT TERM…WASULA
LONG TERM…HWJIV
AVIATION…GJM
HYDROLOGY…11/WASULA
