000
FXUS61 KALY 080816
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
316 AM EST FRI FEB 8 2013
.SYNOPSIS…
ONE STORM WILL DECAY IN THE EASTERN GREAT LAKES THIS MORNING AS
ANOTHER MAJOR WINTER STORM DEVELOPS EXPLOSIVELY TODAY. IT WILL
MOVE FROM THE CAROLINA COAST TO THE GULF OF MAINE SATURDAY…BRINGING
SIGNIFICANT SNOW TO THE REGION. HIGH PRESSURE WILL BUILD FROM
QUEBEC TO THE EASTERN SEABOARD FOR THE REST OF THE WEEKEND…AND
SLIDE OFFSHORE SUNDAY NIGHT. ANOTHER STORM WILL MOVE FROM THE
UPPER GREAT LAKES INTO CENTRAL QUEBEC EARLY IN THE WEEK…DRAGGING
A SERIES OF FRONTS THROUGH OUR REGION AND BRINGING UNSETTLED
WEATHER MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/…
A POWERFUL WINTER STORM TO IMPACT THE REGION THROUGH TONIGHT…
AS OF 1AM CLOUDS HAVE OVERSPREAD REGION…SOME LIGHT SNOW OVER NORTHWEST
AREAS…TEMPERATURES TRENDING AS EXPECTED…FORECAST ON TRACK. NO
CHANGES TO GRIDS ANTICIPATED.
VERY DRY AIR REMAINS IN PLACE THUS FAR…WITH DEW POINTS IN THE
SINGLE DIGITS IN MOST PLACES. IT LOOKS TO REMAIN DRY THROUGH
MIDNIGHT FOR MOST AREAS EXCEPT FOR PERHAPS PORTIONS OF THE WESTERN
MOHAWK VALLEY AND ADIRONDACKS…WHERE THE COLUMN APPEARS TO BE MOISTENING
UP SUFFICIENTLY FOR SOME SPOTTY LIGHT SNOW TO DEVELOP. THE CHC
FOR LIGHT SNOW WILL INCREASE ACROSS THE ENTIRE REGION DURING THE
REMAINDER OF THE OVERNIGHT HOURS…BUT ANY ACCUMULATIONS OVERNIGHT
LOOK LIGHT…WITH JUST A COATING ACROSS MOST AREAS /WITH PERHAPS
AN INCH OR TWO ACROSS THE ADIRONDACKS…MOHAWK VALLEY AND SARATOGA
LAKE GEORGE REGION.
A WINTER STORM WARNING HAS BEEN ISSUED FOR THE MAJORITY OF THE
REGION. THE EXCEPTION IS LITCHFIELD COUNTY CONNECTICUT…WHERE A
BLIZZARD WARNING HAS BEEN ISSUED.
DESPITE THIS STORM BEING IN THE NEAR-TERM PERIOD…THE MODELS ARE
STILL NOT IN TOTAL AGREEMENT ON THE EXACT TRACK OF THE UPCOMING
STORM. THIS WILL HAVE AN IMPACT ON JUST HOW MUCH PRECIPITATION
OCCURS ACROSS OUR AREA. EVEN WITH THIS UNCERTAINTY…THERE STILL
IS ENOUGH OF A SIGNAL IN THE GUIDANCE TO HAVE THE CONFIDENCE TO
ISSUE WINTER STORM WARNINGS/BLIZZARD WARNINGS ACROSS THE FORECAST
AREA. SNOW RATIOS SHOULD BE AT LEAST CLIMO /12.5:1/ OR
GREATER…AS OPTIMAL SNOW CRYSTAL GROWTH IS EXPECTED…MAINLY
DURING FRIDAY NIGHT.
DURING THE DAYTIME ON FRIDAY…LIGHT SNOW WILL DEVELOP ACROSS MUCH
OF THE REGION DUE TO WARM AIR ADVECTION WELL OUT AHEAD OF THE
STORM THAT BEGINS TO RAPIDLY DEEPEN OFF THE MID ATLANTIC COAST.
SNOWFALL WILL BECOME MORE STEADY AND HEAVIER IN INTENSITY BY
LATE FRIDAY AFTERNOON…AS SOME ATLANTIC MOISTURE GETS INVOLVED.
JUST A FEW INCHES WILL LIKELY OCCUR THROUGH FRIDAY AFTERNOON…BUT
THE MAIN SHOW IS STILL YET TO COME.
AS THE LOW BOMBS OUT OFF THE JERSEY SHORE FRIDAY EVENING…FRONTOGENESIS
WILL LEAD TO A PERIOD OF MODERATE TO HEAVY SNOW ACROSS OUR
AREA…ESPECIALLY OUR NEW ENGLAND ZONES…WHERE MESOSCALE BANDING
WILL LIKELY TAKE PLACE. SNOW RATES ON FRIDAY EVENING WILL EXCEED
ONE INCH PER HOUR IN MANY AREAS…AND PARTS OF
BERKSHIRE/LITCHFIELD COUNTY MAY EVEN SEE SNOW RATES OF UP TO THREE
INCHES PER HOUR AT TIMES.
850 HPA U WIND ANOMALIES WILL BE ABOUT 2 TO 5 STD BELOW NORMAL.
THIS WILL ALLOW FOR A STRONG FETCH OF EASTERN FLOW ACROSS OUR
REGION…TRANSPORTING PLENTY OF ATLANTIC MOISTURE INTO THE AREA.
WITH THE DEVELOPING LOW…NE WINDS WILL BECOME STRONG DURING THE
OVERNIGHT HOURS…ESP ACROSS LITCHFIELD COUNTY. A SEVERAL HOUR
PERIOD OF WIND GUSTS OF 30-35 MPH…ALONG WITH HEAVY
SNOWFALL…LOOKS OT OCCUR ACROSS LITCHFIELD…WHICH IS WHY A
BLIZZARD WARNING HAS BEEN ISSUED. ELSEWHERE…WIND GUSTS OF 15 TO
30 MPH ARE POSSIBLE…WHICH MAY ALLOW FOR SOME BLOWING AND
DRIFTING OF THE SNOW ACROSS THE REMAINDER OF OUR AREA AS WELL.
SNOWFALL WILL WIND DOWN AROUND SUNRISE ON SATURDAY…ALTHOUGH
LINGERING SNOW SHOWERS COULD KEEP UP UNTIL NEARLY NOON ACROSS OUR
FAR EASTERN AREAS.
THE BIGGEST QUESTION IS HOW MUCH TOTAL SNOW WILL OCCUR. WE HAVE
SIDED GENERALLY WITH THE 00Z/12Z ECMWF QPF…AS THE ECMWF HAS BEEN
FAIRLY CONSISTENT FROM RUN TO RUN. THE ECMWF HAS ALSO BEEN
GENERALLY IN THE MIDDLE REGARDING THE STORM TRACK BETWEEN THE 12Z
GFS MODEL…WHICH IS TOO FAR EAST…AND THE 12Z NAM…WHICH IS
MUCH TOO FAR WEST. THE 12Z NAM IS CERTAINLY WELL OVERDONE WITH
IT/S QPF ACROSS OUR AREA. THE 09Z SREF GUIDANCE WOULD SUGGEST THAT
THE 00Z/12Z ECMWF LOOKS ON TRACK WITH BOTH IT/S TRACK AND EXPECTED
QPF AS WELL.
OUR CURRENT FORECAST CALLS FOR 8-12 INCHES OUR NORTHERN/NORTHWESTERN
ZONES…AROUND 10-12 INCHES ACROSS THE CAPITAL REGION/SCHOHARIE
VALLEY…10-16 INCHES ACROSS THE EASTERN CATSKILLS/MID HUDSON
VALLEY…12-16 INCHES ACROSS THE TACONICS AND SRN VT…12-18
INCHES ACROSS THE BERKSHIRES…AND 15-25 INCHES ACROSS LITCHFIELD
COUNTY.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/…
BY SAT MORNING MAJOR WINTER STORM HAS BOMBED OUT…AND IS VERTICAL
SOUTH OF CAPE COD…MOVING OUT TO SEA. SOME COLD CONVEYOR BELT
LIGHT SNOW WILL LINGER INTO THE MORNING HOURS. SFC HIGH AND LOW
POSITIONS AND MAV GUIDANCE WOULD SUGGEST SOME FURTHER LINGERING
-SN IN CAPITAL REGION IN HUDSON MOHAWK CONVERGENCE. WHAT SNOW THAT
REMAINS WILL EXIT THE REGION BY MIDDAY. MUCH OF THE DAY A STRONG
SFC WIND GRADIENT WILL BE OVER THE RGN WITH 10-20MPH SFC WINDS AND
HIGHER GUSTS. THIS DRIVES A SHORT LIVED SURGE OF ARCTIC AIR INTO
THE FCA.
IN WAKE OF DEPARTING STORM SATURDAY NIGHT SHARP 500HPA RIDGE WILL
BUILD OVER THE EASTERN STATES FOR THE WEEKEND…AS SFC HIGH BUILDS
FROM QB INTO EASTERN GRTLKS SAT…AND TO THE SEABOARD SUNDAY. WITH
SURGE OF ARCTIC AIR HIGHS SAT WILL BE IN 20S WITH SOME TEENS NORTH
AND NEAR 30 FAR SE. WITH FRESH SNOW COVER…CLEAR SKIES AND SFC
HIGH SETTLING IN OVERHEAD SAT NIGHT…WINDS SHOULD BECOME LT
OVERNIGHT AND TEMPS WILL PLUNGE TO NEAR ZERO SOUTH AND TO 20
BELOW UP NORTH.
SUNDAY A MODERATION TREND WILL BEGIN AS 500HPA AND SFC HIGH AXIS
ARE OVER RGN. SHOULD BE A BRIGHT SUNNY COLD DAY WITH TEMPS
REBOUNDING TO 20S TO LOW 30S.
SUNDAY NIGHT SFC HIGH AND 500 HPA RIDGE MOVE OFFSHORE. CUTOFF
500HPA AND ITS VERTICAL SFC LOW MOVES THROUGH THE WESTERN GRTLKS
AND INTO QB MONDAY. OTHER THAN A PASSING SHORT WV FCA IS WELL
OUTSIDE MOST OF UPR DYNAMICS…BUT IS IMPACTED BY SERIES OF SFC
FRONTS MONDAY. WITH STRONG WAA AHEAD OF WMFNT AND IN RETURN FLOW
OF DEPARTING SFC HIGH TEMPS WILL REBOUND SHARPLY. PCPN WILL START
AS -SN BUT SHOULD QUICKLY BCM MIXED AND CHANGE TO -SHRA IN ALL
AREAS. GUID TEMPS REACH 40S IN MOST AREAS MONDAY. GIVEN EXTENSIVE SNOW
COVER…THIS MAY BE TOO AGGRESSIVE AND WILL TAKE THEM BACK A FEW
DEGREES. THIS WILL ENHANCE THE CHC OF A FEW HOUR PERIOD OF -ZR/IP
MONDAY BFE PCPN CHANGES TO RN WITH SUCH A COLD BOUNDARY LAYER.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/…
THIS WILL BE TYPICAL UPSTATE NY FEB WEATHER WITH VRBL CLOUDS
-SHSN PARTICULARLY NW FCA…NR TO SLIGHTLY ABV NORMAL TEMPS. A FAST
ZONAL 500HPA FLOW WITH A SERIES OF PASSING 500HPA SHORT WVS. WK CD
ADVECTION DOMINATES THE PERIOD WITH A LK EFFECT RESPONSE MAINLY
TUE FM TUG HILL INTO W PTNS OF FCA AS SFC FLOW IS FAVORABLE AND
STRONG 500HPA TROF PASSES THROUGH. WEAK SFC HIGH PRESSURE SETS UP
OVER RGN FOR REMAINDER OF EFP. BUT IN WLY FLOW WITH A FEW WEAK
500HPA SHORT WVS SCT FLURRIES WILL PERSIST REGION WIDE. AT THE END
OF THE FCST PERIOD A MORE SIGNIFICANT FRONTAL BOUNDARY BEGINS TO
SET UP FROM ST LAWRENCE VLY THRU E GRTLKS BACK INTO MIDWEST. WILL
POPULATE WITH MIDNIGHT SHIFT HPC…ADJUST FOR LK EFFECT TUES.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/…
POWERFUL WINTER STORM WILL IMPACT THE REGION FRIDAY INTO EARLY
SATURDAY.
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH SUNRISE AT THE
KGFL/KALB/KPSF/KPOU TAF SITES. RADAR ECHOES/SNOW CURRENTLY SHOWN ON
THE KENX RADAR DO NOT APPEAR TO BE REACHING THE SURFACE IN A
WIDESPREAD WAY. NOT SURPRISING SINCE DEWPOINT ARE STILL IN THE
SINGLE NUMBERS IN MOST PLACES. THIS SNOW IS ASSOCIATED WITH THE
UPPER LEVEL TROF/WEAK SURFACE LOW MOVING THROUGH THE GREAT LAKES AND
WILL HAVE THE GREATEST IMPACT AT KGFL WHERE VFR/MVFR CONDITIONS
POSSIBLE THROUGH 10Z…AND MVFR/IFR CONDITIONS STARTING AROUND 10Z.
OTHERWISE…EXPECT MAINLY VFR CONDITIONS AT KALB/KPOU/KPSF THROUGH
SUNRISE WITH MVFR CONDITIONS POSSIBLE AFTER 10Z.
AFTER SUNRISE THE SNOW ASSOCIATED WITH THE DEVELOPING STRONG COASTAL
LOW WILL BEGIN TO OVERSPREAD THE REGION AND TAF SITES…BY 14Z/15Z
EXPECT ALL TAF SITES TO LOWER TO IFR CONDITIONS IN LIGHT SNOW…WITH
CONDITIONS FURTHER DETERIORATING TO LIFR/VLIFR IN MODERATE TO HEAVY
SNOW LATE FRIDAY AFTERNOON AND EVENING. THOSE CONDITIONS SHOULD
PERSIST THROUGH THE END OF THE TAF PERIOD (06Z SATURDAY).
WINDS WILL REMAIN NORTHEAST TO EAST THROUGH SUNRISE AT LESS THAN 10
KTS…THEN INCREASE TO 8 TO 12 KT FRI MORNING…AND 10-15 KT BY LATE
FRIDAY AFTN AND EVENING WITH GUST OF 20 TO 25 KTS.
OUTLOOK…
LATE FRI NIGHT. IFR/LIFR WITH MODERATE TO HEAVY SNOW.
SAT…MVFR/VFR…CHC -SN.
SAT NIGHT-SUN NIGHT…VFR…NO SIG WX.
MON-MON NIGHT…MVFR/IFR. CHC -SN/-PL/-FZRA CHANGING TO -RA.
TUE…VFR/MVFR. SLIGHT CHC -SHRA/-SHSN.
&&
.HYDROLOGY…
WIDESPREAD HYDRO PROBLEMS ARE NOT ANTICIPATED OVER THE NEXT FEW
DAYS AS OUR COLD WEATHER CONTINUES WITH ALL PRECIPITATION TOMORROW
INTO TOMORROW NIGHT 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 THROUGH
THE WEEKEND.
EARLY NEXT WEEK…DAYTIME TEMPERATURES MAY RISE ABOVE
FREEZING…ALONG WITH THE POSSIBILITY FOR A LIGHT WINTRY MIX ON
MONDAY. THESE TEMPERATURES MAY ALLOW FOR SOME SNOW MELT…AND A SLOW DOWN ON
THE DEVELOPMENT OF ICE…BUT NO HYDRO ISSUES ARE ANTICIPATED AT
THIS TIME.
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…BLIZZARD WARNING FROM 6 AM THIS MORNING TO NOON EST SATURDAY
FOR CTZ001-013.
NY…WINTER STORM WARNING FROM 6 AM THIS MORNING TO NOON EST
SATURDAY FOR NYZ032-033-038>043-047>054-058>061-063>066-
082>084.
MA…WINTER STORM WARNING FROM 6 AM THIS MORNING TO NOON EST
SATURDAY FOR MAZ001-025.
VT…WINTER STORM WARNING FROM 6 AM THIS MORNING TO NOON EST
SATURDAY FOR VTZ013>015.
&&
$$
SYNOPSIS…SNYDER
NEAR TERM…FRUGIS/KL/GJM
SHORT TERM…SNYDER
LONG TERM…SNYDER
AVIATION…GJM
HYDROLOGY…SNYDER
