000
FXUS61 KALY 240231
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
931 PM EST MON NOV 23 2009

.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM POSITIONED OFF THE MID ATLANTIC COAST 
WILL CONTINUE TO TRACK NORTHEASTWARD TONIGHT...AND WILL PASS EAST OF 
CAPE COD ON TUESDAY. A MOIST ONSHORE FLOW WILL RESULT IN MAINLY 
LIGHT RAIN OR DRIZZLE ACROSS PORTIONS OF THE REGION TONIGHT INTO 
EARLY TUESDAY MORNING...ESPECIALLY SOUTH AND EAST OF ALBANY. WEAK 
HIGH PRESSURE WILL BUILD IN ON TUESDAY...WITH TRANQUIL CONDITIONS 
PERSISTING INTO WEDNESDAY.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
CLOUDS CONTINUE TO ADVANCE NORTH...ALONG WITH PATCHES OF LIGHT
RAIN AND DRIZZLE. BASED ON BOUNDARY LAYER FLOW...AND CURRENT RADAR
TRENDS...UPPED RAIN CHANCES IN SOUTHERN VT A BIT. CLOUD COVER AND
PRECIPITATION...ALONG WITH LIGHT WINDS...SUGGESTS THAT MINIMUM
TEMPERATURES SHOULD BE A DEGREE OR TWO WARMER THAN CURRENT
FORECAST. OTHERWISE...NO OTHER CHANGES.

PREV AFD BELOW...

AS OF 315 PM...A NORTHEAST ONSHORE FLOW RESULTING IN STRATUS CLOUDS 
ENCOMPASSING THE ENTIRE FORECAST AREA. THE MAIN SFC WAVE IS RATHER 
WEAK AND POSITIONED WELL TO OUR SOUTH AND EAST...HOWEVER A 1032MB 
AREA OF HIGH PRESSURE OVER SOUTHERN QUEBEC IS PROVIDING THE 
NORTHEAST FLOW. SO FAR MAIN EFFECT HAS BEEN INCREASING CLOUD 
COVER...HOWEVER THERE WILL BE A BETTER CHANCE FOR SOME RAIN TONIGHT 
AS WEAK ISENTROPIC LIFT ON THE 290K SURFACE LIFTS NORTHWARD ACROSS 
MAINLY SOUTHERN AREAS. FORECAST SOUNDINGS SHOWING DRY LAYER 
PERSISTING ALOFT WITH LOW LEVELS MOISTENING...SO THERE WILL BE SOME 
DRIZZLE AROUND AS WELL. WILL MENTION LIKELY POPS SOUTH AND EAST OF 
ALBANY...WITH CHANCE ACROSS CENTRAL AREAS. PORTIONS OF THE 
ADIRONDACKS WILL REMAIN DRY. FORCING WEAKENS AFTER MIDNIGHT...SO 
WILL GO WITH JUST CHANCE POPS FOR THE SECOND HALF OF THE NIGHT. DUE 
TO EXTENSIVE CLOUD COVER MIN TEMPS WILL BE AROUND 5-10 DEGREES ABOVE 
AVG.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 345 PM...NORTHEAST ONSHORE FLOW STILL EXPECTED TO PERSIST
THROUGH TUE MORNING...ALTHOUGH WILL BE WEAKENING. ALSO...NO
DISCERNIBLE FORCING WILL BE PRESENT SO WILL ONLY MENTION LOW
CHANCE POPS IN THE MORNING...WHICH SHOULD BE EITHER LIGHT RAIN OR
DRIZZLE. LACK OF ANY SUBSTANTIAL DRYING/MIXING WILL RESULT IN
CLOUD COVER PERSISTING INTO THE AFTERNOON. SOME BREAKS IN THE
CLOUDS MAY OCCUR VERY LATE IN THE DAY...BUT APPRECIABLE WARMING
WILL LIKELY NOT TAKE PLACE SINCE SUNSET IS AROUND 430 PM.
SO...WILL UNDERCUT BOTH MAV/MET GUIDANCE BY A FEW DEGREES FOR MAX
TEMPS.

TUE NIGHT AND WED SHOULD BE TRANQUIL WITH WEAK HIGH PRESSURE IN 
CONTROL. AGAIN...THE MAIN CHALLENGE WILL BE DETERMINING TEMPS WITH 
VARYING CLOUD COVER. IT APPEARS THAT THERE WILL BE A GRADUAL 
CLEARING TREND TUE NIGHT...WITH MOST AREAS SEEING APPRECIABLE BREAKS 
IN CLOUD COVER SO WILL LEAN TOWARDS COOLER MAV GUIDANCE FOR MIN 
TEMPS. WED WILL BE A MILD DAY WITH A RETURN SOUTHERLY FLOW 
DEVELOPING...AS HIGH PRESSURE DRIFTS TO OUR EAST. AT THIS POINT 
EXPECTING AT LEAST A MIX OF SUN AND CLOUDS AND TEMPS SHOULD RESPOND 
BY WARMING INTO THE LOWER TO MID 50S IN MOST LOCATIONS.

A WEAKENING PIECE OF ENERGY BREAKING OFF FROM THE MAIN UPPER LEVEL 
TROF ACROSS THE MIDWEST...WILL LIFT NORTHEASTWARD ACROSS THE GREAT 
LAKES REGION WED NIGHT. NOT MUCH MOISTURE TO WORK WITH AND FORCING 
WILL BE WEAK...SO WILL ONLY MENTION CHANCE POPS WEST OF THE HUDSON 
RIVER. MIN TEMPS SHOULD BE ABOVE FREEZING ACROSS THE AREA WITH 
INCREASING CLOUDS AND A LIGHT SOUTHERLY BREEZE.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
CONSENSUS CONTINUES TO BUILD REGARDING THE BLACK FRIDAY COASTAL 
STORM...THUS HAVE GONE WITH HPC'S SOLUTION.  AT THE PRESENT TIME... 
IT APPEARS COLD AIR WILL BE TOO LIMITED TO WARRANT SNOW IN THE LOWER 
AND SOUTHERN REACHES OF OUR FORECAST AREA.  INDEED...A LOOK AT SFC- 
500 MB THICKNESSES INDICATES SUB-540 VALUES DON'T MOVE IN UNTIL VERY 
LATE IN THE GAME.  THE EASTERLY WIND FLOW NORTH OF THE APPROACHING 
LOW THURSDAY LOW WILL ACTUALLY BE BRINGING IN SLIGHTLY MODIFIED 
AIR...SO THAT OVERNIGHT LOWS THURSDAY NIGHT ARE EXPECTED TO STAY 
ABOVE FREEZING EXCEPT IN THE ADIRONDACKS...WHERE A MOSTLY SNOW EVENT 
IS EXPECTED.  TEMPERATURES WON'T LIFT MUCH ON FRIDAY WITH THE CLOUDS 
AND THE PRECIP...BUT HIGHS AROUND 40 IN THE HUDSON VALLEY ARE 
EXPECTED...WHICH ALMOST CERTAINLY SUGGESTS AN ALL-RAIN EVENT THERE 
THROUGH FRIDAY.  ELSEWHERE...A MIX IS EXPECTED...AND IT WOULD BE 
DIFFICULT TO ENVISION ANY SIGNIFICANT ACCUMULATIONS EXCEPT IN THE 
MOUNTAINS...DESPITE THE GFS'S SUGGESTED SIGNIFICANT QPFS...WHICH 
TOTAL MAINLY BETWEEN AN INCH AND 1.50 INCHES FOR THE EVENT.  SO... 
FOR MOST OF US...THIS IS NOW LOOKING LIKE MORE OF A SIGNIFICANT RAIN 
EVENT.

BEYOND FRIDAY...SNOW WILL BECOME THE MORE DOMINANT WEATHER FEATURE 
ON SATURDAY AS THE LOW MOVES UP THROUGH MAINE AND THE CANADIAN 
MARITIMES...AND THE PRECIPITATION BECOMES LIGHTER AND MORE SHOWERY 
DUE TO A NORTHWESTERLY FLOW AND BACK-END LAKE ENHANCEMENT.  POPS 
DECREASE RAPIDLY THROUGH SATURDAY NIGHT AS HIGH PRESSURE RIDGES IN 
FROM THE SOUTHEASTERN U.S....AND WINDS TURN MORE SOUTHWESTERLY.

LOW PRESSURE FROM SOUTHWESTERN CANADA WILL TRACK TO THE GREAT LAKES 
THROUGH MONDAY...BRINGING OUR NEXT CHC FOR SIGNIFICANT PRECIP...AND 
THE ATMOSPHERE LOOKS COLD ENOUGH THAT THIS STORM COULD WIND UP 
BRINGING THE FIRST SIGNIFICANT SNOWS FOR MUCH OF THE REGION.

&&

.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
SCATTERED RADAR ECHOES CLOSE TO BUT MOSTLY EAST OF THE AIRPORTS AT 
2315Z.  CARRYING VCSH AT GFL AND ALB.  EXPECTING LITTLE MORE THAN 
-DZ AT POU OVERNIGHT.  CONDITIONS EXPECTED TO DROP TO MVFR CIG/VSBY 
AT ALL 3 AIRPORTS THIS EVENING...BEFORE RETURNING TO VFR SHORTLY 
AFTER DAYBREAK TUE AS A HIGH PRESSURE RIDGE BUILDING DOWN THE 
EASTERN SEABOARD WINS THE DAY.  SURFACE WINDS WILL BE LIGHT AND 
VARIABLE...WITH WINDS AT 2000 FEET BEYOND 20 KTS EXPECTED ONLY AT 
POU.  NO WIND SHEAR ISSUES.
   
OUTLOOK... 
TUE NGT-THANKSGIVING DAY...VFR...NO SIG WX. 
THU NGT-FRI...VFR TO MVFR/IFR...RAIN LIKELY.
FRI NGT-SAT...CHC -SHRA/-SHRASN...THEN GRADUALLY IMPROVING TO VFR.

&&

.HYDROLOGY...
RAINFALL AMOUNT ARE EXPECTED TO BE AROUND ONE TENTH OF AN INCH OR 
LESS ACROSS THE AREA TONIGHT...MAINLY SOUTH AND EAST OF ALBANY. THIS 
AMOUNT OF RAINFALL WILL HAVE VERY LITTLE IMPACT ON RIVERS AND 
STREAMS. THE NEXT CHANCE OF WIDESPREAD PRECIPITATION WILL BE FROM 
LATE THURSDAY NIGHT INTO THE WEEKEND...AS A POTENTIALLY STRONG STORM 
MAY IMPACT THE REGION. SIGNIFICANT PRECIPITATION IS POSSIBLE BUT 
PRECIP AMOUNTS AND TYPE ARE HIGHLY UNCERTAIN 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...NONE.
NY...NONE.
MA...NONE.
VT...NONE.

&&

$$
SYNOPSIS...NAS
NEAR TERM...NAS