February 11, 2013 Forecast Discussion

000
FXUS61 KALY 112028
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
328 PM EST MON FEB 11 2013

.SYNOPSIS…
ONE COLD FRONT WILL CROSS THE REGION THIS EVENING…AND ANOTHER
OVERNIGHT. IN THEIR WAKE TONIGHT AND TUESDAY…A COOLER MOIST
WESTERLY FLOW WILL COVER THE REGION WITH SOME SHOWERS OF RAIN OR
SNOW…AND SOME LAKE EFFECT INTO THE WESTERN ADIRONDACKS. WEAK
HIGH PRESSURE WILL CREST ACROSS THE REGION TUESDAY NIGHT AND
EARLY WEDNESDAY. WEDNESDAY NIGHT A STORM WILL MOVE NORTHEAST FROM
DELMARVA…BRINGING CLOUDS AND THE THREAT OF SOME SNOW TO
SOUTHERN PARTS OF THE REGION.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/…
CDFNT JUST W OF ART-SYR LINE AT 3PM. TEMPS ABV FREEZING IN ALL AREAS
AND UNTIL FROPA. PCPN HAS ENDED. WWA HAS BEEN TERMINATED. SCT
-SHRA AND -SHSN WILL ACCOMP CFP THIS EVENING PARTICULARLY W PTNS
OF FCA. AT THE SFC 1ST CDFNT MOVES ACROSS FCA DURING THE EVENING
HRS. OVERNIGHT A SECONDARY CDFNT CROSS THE RGN. MORE SIGNIFICANT
FACTOR WILL BE A MOIST SLIGHTLY UNSTABLE W-NW FLOW ACROSS THE RGN
AS THE 500HPA CUTOFF AND ITS TRAILING TROF TRANSIT THE RGN TNGT.
MAINLY VRBL CLOUDS…SCT -SHRA/SHSN AND A MODEST LK EFFECT
ENHANCEMENT OF SHOWER ACTIVITY IN N AND W FA OVERNIGHT.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/…
INCRG AGREEMENT IN THE MODEL SUITE IN THIS FCST PERIOD. GEM/NAM/GFS DRAG
500HPA TRO THROUGH THE REGION TUES MORNING…AND THE 500HPA CUT OFF
TO THE MARITIMES BY TUES AFTN. SCT -SHRA/SHSN AND A MODEST LK EFFECT
ENHANCEMENT OF SHOWER ACTIVITY IN N AND W FA CONT MUCH OF TUES.

TUES NT AND WED MORNING WK 500HPA RIDGE AND BUBBLE SFC HIGH CROSS
FA. THEN THINGS GET INTERESTING…AGAIN.

WED AFTN AND NT A FAST MOVING SOUTHERN STREAM SHORT WV MOVES FM
OHIO VLY TO THE COAST…INTERACTING WITH THE BAROCLINIC ZONE
ACROSS THE SOUTHERN STATES…LOW PRESSURE DEVELOPS IN GULF COAST
STATES MOVING TO HAT BY EVENING THEN NE…PASSING SVRL HUNDRED MILES
S OF CAPE COD. THIS BRINGS CLOUDS TO ALL OF FCA EXCEPT FAR
NW. LIGHT SNOW TO FAR S TIER OF ZNS FROM ULSTER TO LITCHFIELD
COUNTY…A SUB ADVISORY TYPE SNOW EVENT ON THE ORDER OF A DUSTING
TO A COUPLE OF INCHES. WE HAVE AGREEMENT IN GENERAL WITH THE
GEM/GFS/HPC. THE NAM IS CLOSER TO COAST WITH STORM TRACK AND MORE
AGGRESSIVE WITH MORE QPF WHILE 00UTC ECMWF TAKING IT FURTHER SOUTH
AND MISSING FCA WITH PCPN.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/…
FCA REMAINS IN FAST 500HPA FLOW WITH SVRL SHORT WVS RACING ACROSS
FCA. THE FIRST OF THESE THU NT AND FRI IS A CLIPPER TYPE SYSTEM
ACCOMP BY SOME -SHSN/-SHRN AND ENHANCED BY LAKE RESPONSE OVER W PRTNS OF
FCA. THU AND FRI WILL BRING ABV NORMAL TEMPS…IN THE WAKE OF THE
FRI CDFNT AND CAA TEMPS WILL COOL TO BLO NORMS FOR REST OF EFP.

DURING THE WEEKEND A SERIES OF 500HPA SHORT WVS WILL CARVE A FULL
LATITUDE TROF OVER THE EASTERN THIRD OF THE NATION. THE MODEL
SUITE EVOLVES ALONG SEVERAL PATHWAYS.

THE GFS EVOLVES A MAJOR NEGATIVELY TILTED TROF IN THE EAST WITH
BOMBOGENISUS OFF THE EASTERN SEABOARD SAT NT INTO SUN…AND A
MAJOR STORM. THE TRACK IS HATTERAS TO DELMARVA…THEN 300 MILES SOUTH
OF CAPE COD. THIS IS FARTHER SOUTH AND EAST THAN THE RECENT STORM.
THE FCA TAKES A GLANCING BLOW WITH LT SNOW ONLY. THE ECMWF DEVELOPS
THE SYSTEM EVEN FURTHER SOUTH AND EAST…WITH A GLANCING BLOW
CONFINED TO THE FAR MOST SE FCA. THE GEM TRACK IS I-95 INSIDE THE
BENCHMARK AND SUGGESTS A MAJOR SNOW EVENT HERE. AT THIS POINT
THE GEM IS THE OUTLIER. THE GFS ENSEMBLE HAS 3 MEMBERS WITH A
SIGNIFICANT EVENT AT ALB…A FEW WITH A TENTH OR SO QPF…AND THE
REST ARE FLAT LINES. HPC HAS NO POPS WEST OF ALB FOR THIS
EVENT…AND A TRACK CLOSE TO THE GFS.

IN THIS SYSTEMS WAKE A FULL LATITUDE 500HPA TROF SETS UP ALONG
THE EAST COAST…AND ARCTIC HIGH PRESSURE PLUNGES SOUTH FROM
HUDSON BAY CANADA. STRONG CAA WILL IMPACT FCA…FOR REST OF
EFP…TEMPS WILL BE 5-10 DEG BLO NORMAL AND SHORT WVS AND NW FLOW
ACROSS GRTLKS WILL RESULT IN USUAL DOWNWIND LK RESPONSE INTO FCA
WITH SCT TO MORE NUMEROUS -SHSN W.

WILL POPULATE EFP WITH GMOS/GFS.

&&

.AVIATION /21Z MONDAY THROUGH SATURDAY/…
STEADY PRECIPITATION HAS ENDED. SHOWERS ARE DEVELOPING TO THE WEST
AND SCATTERED SHOWERS COULD BE AROUND KALB…KGFL AND KPSF THROUGH
THIS AFTERNOON…BUT COVERAGE NOT ENOUGH FOR A TEMPO. SOME PATCHY
FOG COULD LINGER AT KGFL AND KPSF DUE TO THE LIGHT WINDS AND THE
MOISTURE ON THE SNOW PACK. STRONG WINDS AT AROUND 2000 FEET WILL
CREATE SOME WIND SHEAR AT KGFL AND KPSF FOR PART OF THIS
AFTERNOON…UNTIL THE WINDS ALOFT WEAKEN A BIT AND THE SURFACE WINDS
AT KGFL AND KPSF INCREASE.

ADDITIONAL SCATTERED RAIN AND SNOW SHOWERS ARE POSSIBLE WITH A COLD
FRONTAL PASSAGE AROUND AND AFTER MIDNIGHT. THE CHANCES FOR
SCATTERED RAIN AND SNOW SHOWERS SHOULD END BY DAYBREAK. PUTTING VCSH
IN KGFL…KALB AND KPSF OVERNIGHT INTO THE EARLY MORNING HOURS.

CEILINGS SHOULD BECOME VFR BEFORE 12Z…AND CONTINUE THROUGH 18Z
TOMORROW. VISIBILITIES SHOULD BE VFR AS WELL…OUTSIDE OF ANY RAIN
OR SNOW SHOWERS DURING THE EARLY MORNING HOURS.

SOUTH WINDS AT 10 TO 15 KT AT KALB WILL CONTINUE INTO THIS
EVENING…WHILE KGFL…KPSF AND KPOU HAVE LIGHT WINDS BECOMING SOUTH
AT 10 KT OR SO THIS AFTERNOON. WINDS WILL SHIFT TO SOUTHWEST AND
WEST BY DAYBREAK. THEN…TOMORROW MORNING…WINDS SHOULD BECOME WEST
AND INCREASE TO 10 TO 15 KT AT ALL SITES WITH GUSTS AROUND 25 KT.

OUTLOOK…
TUE…VFR/MVFR. CHC -SHSN KGFL…KALB AND KPSF.
WED…VFR. NO SIG WX.
WED NIGHT…MAINLY VFR. CHC -SN KPOU. OTHERWISE SLIGHT CHC.
THU…VFR. NO SIG WX.
FRI-SAT…VFR/MVFR. CHC -SN AND -RA.

&&

.HYDROLOGY…
NO HYDRO PROBLEMS ARE EXPECTED THE NEXT 5 DAYS.

TEMPERATURES WILL BE 5 DEGREES OR SO ABV NORMAL TILL THE WEEKEND
BUT WILL BE COOL ENOUGH TO PREVENT ANY NOTICEABLE SNOW MELT. THERE`S
A POTENTIAL FOR 0.1 TO 0.3 QPF LATE SAT AND SUNDAY…MAINLY SOUTH
AND EAST…BUT THIS WILL FALL AS SNOW IF IT OCCURS.

MUCH COLDER ARCTIC AIR WILL MOVE INTO THE REGION DURING THE
WEEKEND…AND ICE WILL BEGIN TO FORM OR THICKEN.

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…SNYDER
NEAR TERM…SNYDER
SHORT TERM…SNYDER
LONG TERM…SNYDER
AVIATION…NAS
HYDROLOGY…SNYDER

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