Area Forecast Discussion
Issued by NWS Albany, NY

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000
FXUS61 KALY 271421
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
921 AM EST SAT DEC 27 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE EASTERN SEABOARD WILL DRIFT OFFSHORE TODAY
AS A COLD FRONT APPROACHES FROM THE GREAT LAKES REGION. THE COLD
FRONT WILL CROSS THE REGION LATE TONIGHT AND SUNDAY MORNING WITH
RAIN SHOWERS AND SNOW SHOWERS OVER SOME HIGHER TERRAIN. SUNDAY
EVENING INTO MIDWEEK A VERY LARGE CANADIAN HIGH PRESSURE SYSTEM
WILL RIDGE INTO THE NORTHEAST WITH GENERALLY FAIR AND MORE
SEASONABLE TEMPERATURES TO END THE YEAR.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF 9 AM EDT...CLOUDS WERE PERSISTENT ACROSS THE NORTHERN TWO
THIRDS OF THE FA WITH MOSTLY SUNNY SKIES ACROSS THE SOUTHERN
THIRD OF THE FA. EXPECTING CLOUDS TO THIN FOR A TIME ACROSS
NORTHERN AREAS TODAY ALLOWING FOR PARTLY SUNNY CONDITIONS WHILE
SKIES REMAIN MOSTLY SUNNY SOUTH.

RIDGING WILL SHIFT EASTWARD OFF THE COAST TODAY AND TONIGHT
ALLOWING A LOW PRESSURE SYSTEM TO MOVE ACROSS THE REGION BRINGING
MAINLY RAIN SHOWERS TO THE AREA TONIGHT AND SUNDAY.

THE SURFACE HIGH CENTERED TO OUR SOUTH WILL SHIFT EASTWARD AND OFF
THE SOUTHEAST COAST THIS AFTERNOON AND TONIGHT. DEEP SOUTHWEST FLOW
WILL DEVELOP BETWEEN THE DEPARTING RIDGE AND THE ADVANCING TROUGH.
850 MB TEMPERATURES WILL RISE TODAY ESPECIALLY THIS AFTERNOON...SO
DESPITE CLOUD COVER TODAY WILL FEATURE ABOVE NORMAL TEMPERATURES
RANGING FROM THE UPPER 30S ACROSS PORTIONS OF THE SOUTHERN
ADIRONDACKS INTO THE LOWER 50S IN THE MID HUDSON VALLEY. THESE
VALUES WILL BE UP TO AROUND 15 DEGREES ABOVE NORMAL.

CHANCES FOR SHOWERS WILL INCREASE FROM NORTHWEST TO SOUTHEAST ACROSS
THE FORECAST AREA TONIGHT AS THE LOW LEVEL JET ASSOCIATED WITH THE
SYSTEM MOVES IN AND ACROSS THE REGION. CHANCES WILL BE GREATEST
TO THE NORTHWEST OF THE CAPITAL DISTRICT. IT MAY GET COLD ENOUGH
FOR SOME SNOW ACROSS PORTIONS OF THE SOUTHERN ADIRONDACKS LATE
TONIGHT...OTHERWISE RAIN SHOWERS ARE EXPECTED. OVERNIGHT READINGS
WILL BE VERY MILD WITH LOWS ONLY IN THE 30S. NORMAL LOWS THIS TIME
OF YEAR ARE GENERALLY FROM 10 TO 20 DEGREES ACROSS EAST CENTRAL
NEW YORK AND WESTERN NEW ENGLAND.

THE COLD FRONT`S SOUTHEAST PROGRESS WILL BE SLOWED BY PARALLEL FLOW
ALOFT. CHANCES FOR SHOWERS WILL GRADUALLY DECREASE FROM NORTH TO
SOUTH SUNDAY WITH CHANCES LINGERING ACROSS SOUTH OF THE CAPITAL
DISTRICT DURING THE AFTERNOON HOURS. SUNDAY WILL AGAIN FEATURE ABOVE
NORMAL TEMPERATURES BUT NOT AS MILD AS SATURDAY.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
DURING THIS PERIOD A FLAT 500HPA RIDGE IN A VERY FAST FLOW OVER
MUCH OF THE EASTERN UNITED STATES WILL FLATTEN AS A SERIES OF
SHORT WAVES KNOCK IT DOWN. MUCH FURTHER WEST IN A NW FLOW AT
500HPA...A MASSIVE 1055 SFC HIGH CENTER WILL DROP SE FM THE
CANADIAN ROCKIES. THIS HIGH WILL ALSO RIDGE AT THE SFC ACROSS THE
EASTERN BORDER REGIONS OF BOTH COUNTRIES. AS A RESULT A RELATIVELY
SHALLOW LAYER OF COLD AIR WILL SETTLE OVER THE NORTHEAST USA..AND
THICKEN AS THE WEEK PROGRESSES.  WHILE OVERALL THIS WILL BE A
QUIET AND MORE OR LESS DRY PERIOD THERE ARE A FEW MODEST FLIES IN
THE OINTMENT TO CONTEND WITH:

1) SUN EVNG THE DEPARTING CDFNT WILL DRIFT S FM THE I95 CORRIDOR...BUT
KEEP CLOUDS OVER THE SE PORTIONS OF THE FCA FOR SVRL HOURS AND POSSIBLY
A SCT EVNG -SHRA IN THE FAR SE.

2) SUN NT A SECONDARY CDFNT FRONT WILL DROP SOUTH ACROSS THE
FCA..BUT GENERALLY WASH OUT..IT MAY TRIGGER A SCT -SNSH OVERNIGHT
N & W OF ALB.

3) GIVEN THE INITIALLY SHALLOW COLD AIR MASS EARLY IN THE
PERIOD...THERE WILL BE CONSIDERABLE VEERING OF THE FLOW WITH N-NE
SFC WINDS BCMG W-NW BY H850PA. THIS ALONG WITH THE PASSING OF AN
ASSORTMENT OF JET MAXES/VORT MAXES WILL RESULTS IN VARYING DEGREES
OF CLOUDINESS AMONG THE MODEL SUITE...BUT ALL IN ALL A PARTLY CLOUDY
REGIME WITH MORE OR LESS AT TIMES.

4) MON NT INTO TUES THE MAJOR BAROCLINIC ZONE LIES FM THE
CAROLINA PIEDMONT NE WARD.  EARLY TUES A CSTL LOW FORMS ALONG THIS
BOUNDARY OFF HAT..AND MOVES ENE. THE GFS/GEM/ECMWF KEEP THIS
SYSTEM ANY ASSOC PCPN JUST S OF FCA ALTHOUGH SOME CLOUDS ARE
LIKELY ACROSS S TIER ASSOC WITH IT.  THE NAM HAS THE WHOLE SYSTEM
ABOUT 100 MILES FURTHER N WITH CLOUDS ACROSS S HALF OF FCST AND
CHC -SN ACROSS S MOST AREAS.  THE TREND AMONG THE REST OF THE MDLS
HAS BEEN TWRD A FURTHER S TRACK THE LAST TWO RUNS...AND FOR NOW
WILL KEEP IT S OF RGN.

5) THE LAST ITEM IS A 500HPA SHORT WV MVNG INTO GRTLKS TUES...AND
AN E-W ARCTIC CDFNT MVNG S THROUGH FCA TUES NT. BESIDES A
REINFORCING TREND TWRD COLD AND NR NORMAL TEMPS...IT WILL ACT TO
TURN THE FLOW TO A W-NW ACROSS THE GRTLKS AND RESULT IN A
DEVELOPING LK RESPONSE TWRD THE END OF THE PERIOD. THIS WILL BE
MAINLY AN INCRG THREAT OF -SHSN TUES NT IN W FCA AS WELL AS INCR
CLOUDS...BUT IT MAY BCMG MORE SIG IN THE EFP.

OVERALL A PERIOD FEATURING VRBL CLOUDS...A RETURN TO NEAR NORMAL
TEMPS...MAINLY DRY...WITH A FEW LOW CHC INTERVALS OF -SHSN. ALL AN
ALL A QUIET WEATHER PERIOD TO END THE YEAR.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
DURING THE FIRST PART OF THE EFP A SERIES OF 500HPA SHORT WVS
CARVE A BROAD TROF OVER THE NORTHEAST...WITH A CUTOFF EAST OF
HUDSONS BAY. BY THE END THE 500HPA FLOW BCMS ZONAL YET AGAIN.

AT THE SFC A SERIES OF CDFNTS DROP S INTO THE RGN...ACTING AS A
FOCUS OF LK EFFECT RESPONSE. THE FIRST IS WED...MAINLY INTO THE W
ADRDKS. THE SECOND E-W CDFNT IS ACCOMP BY A STRONG 500 HPA SHORT
WV THAT DROPS S INTO THE MHWK VLY THU NT. THIS WILL RESULT IN YET
ANOTHER ENHANCED LK EFFECT PERIOD INTO THE W ADRDKS. WHILE THERE
WILL BE LK EFFECT -SHSN INTO THE W ADRDKS OFF AND ON THROUGH THE
PERIOD...AMNTS SHOULD REMAIN MODEST.

ELSEWHERE OTHER THAN STRAY -SHSN WITH THE FRONTAL PASSAGES IT
SHOULD BE DRY AND WITH SEASONABLE TEMPS...VRBL CLOUDS N AND PC
CONDS S. BY THE END OF THE PERIOD THE CDFNT IS STALLED E-W ACROSS
NYS AD BEGINS TO BCM THE FOCUS FOR WAA CLOUDS THAT ARE SPILLING
INTO THE STATE IN THE FAST ZONAL 500HPA.

ECMWF/GFS/WPC IN AGREEMENT DURING THIS PERIOD AND WILL POPULATE
GRIDS WITH HPC AND ADJUST FOR LK EFFECT. HWVR JUST BYND OF THEY SPREAD
WILDLY WITH NEXT SYSTEM.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL SHIFT EASTWARD WITH THE CENTER OF THE SURFACE HIGH
SHIFTING OFFSHORE THE SOUTHEAST COAST THIS AFTERNOON AND EVENING
AS A LOW PRESSURE SYSTEM APPROACHES. THE SURFACE LOW WILL WELL MODELED
TO MOVE ACROSS THE GREAT LAKES REGION INTO EASTERN CANADA TODAY AND
TONIGHT DRAGGING ITS ASSOCIATED COLD FRONT INTO THE REGION. ALOFT
SOUTHWEST FLOW WILL DEVELOP BETWEEN THE DEPARTING RIDGE AND THE
ADVANCING TROUGH. LOWER LEVEL CLOUDS HAVE SPREAD SOUTHWARD AND ARE
IMPACTING KGFL...KALB AND KPSF. THESE CLOUDS SHOULD LINGER WELL
INTO THE AFTERNOON WITH THEM BREAKING UP AS WE HEAD INT THE
EVENING FOR A PERIOD. CIRRUS CLOUDS WILL CONTINUE OT STREAM OVER KPOU.
CLOUDS COVER WILL SPREAD BACK ACROSS THE AREA AS THE LOW PRESSURE
AND COLD FRONT APPROACHES WITH CHANCES FOR SHOWERS INCREASE FROM
NORTHWEST TO SOUTHEAST ACROSS THE FORECAST AREA TONIGHT AS THE LOW
LEVEL JET ASSOCIATED WITH THE SYSTEM MOVES IN AND ACROSS THE
REGION. CHANCES WILL BE GREATEST TO THE NORTHWEST OF THE CAPITAL
DISTRICT. MVFR CONDITIONS ARE NOT EXPECTED UNTIL LATE IN THE TAF
PERIOD.

LIGHT SOUTH-SOUTHWEST FLOW DEVELOPS TODAY WITH A MORE WESTERLY
FLOW AT KPSF.

OUTLOOK...
SUN NIGHT-WED: NO OPERATIONAL IMPACT.  NO SIG WX.

&&

.HYDROLOGY...
RIVER LEVELS ARE NOW RECEDING ACROSS THE REGION...AND WILL
CONTINUE TO DO SO FOR THE NEXT WEEK.

A COLD FRONT IS EXPECTED TO BRING RAIN SHOWERS WITH A MIX OF RAIN/SNOW
ACROSS HIGHER ELEVATIONS LATE TNGT INTO SUN MRNG. QPF WITH THIS
EVENT WILL BE ON THE ORDER OF 0.10 TO 0.40 INCH...GENERALLY
INSIGNIFICANT AMOUNTS TO RIVER FLOWS.

GENERALLY DRY CONDITIONS...AND COLDER TEMPERATURES...ARE EXPECTED
INTO AT LEAST EARLY NEXT WEEK. BY THEN END OF THE PERIOD WITH
DECREASING FLOWS AND NORMAL TEMPS ICE MAY BEGIN TO FORM.

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...IAA/11
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...IAA
HYDROLOGY...SNYDER






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