FXUS61 KALY 051132
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
632 AM EST SAT DEC 5 2009

.SYNOPSIS...
LOW PRESSURE WILL ORGANIZE ALONG THE CAROLINA COAST TODAY MOVING NORTHEAST
WELL OFFSHORE.  THIS LOW WILL PASS ABOUT 300 MILES SOUTHEAST OF
CAPE COD TONIGHT.  SUNDAY HIGH PRESSURE WILL BUILD EAST FROM THE
OHIO AND TENNESSEE VALLEYS TO THE ATLANTIC SEABOARD. SUNDAY NIGHT
IT WILL SLIDE OFFSHORE.  MONDAY A COLD FRONT WILL PUSH THROUGH THE
REGION AND BE FOLLOWED BY ANOTHER HIGH FROM THE MIDWEST FOR
TUESDAY. MIDWEEK A COMPLEX STORM SYSTEM WILL APPROACH FROM THE
SOUTHWEST.

&&

.NEAR TERM /UNTIL 1 PM THIS AFTERNOON/...
A SURFACE LOW IS ORGANIZING OFF THE CAROLINA COAST ATTM. ITS
FORCING IS ORGANIZED INTO TWO AREAS. THE FIRST THE ISENTROPIC LIFT
ASSOCIATED WITH THE WARM CONVEYOR BELT AND THE SURFACE THERMAL
RIBBON OFFSHORE...WHICH WILL REMAIN WELL SOUTH AND EAST OF OUR
REGION...BUT OVER TIME SUPPLY LOW LEVEL MOISTURE.  THE SECOND IS
THE UVM ASSOCIATED WITH AN APPROACHING OPEN 500HPA TROF.  ATTM THE
MID AND HIGH CLOUDS ALONG THE SEABOARD ARE ALREADY OVERSPREADING
THE REGION FROM THE SOUTHEAST AND HAVE GREATLY SLOWED THE DOWNWARD
DROP IN TEMPS THIS MORNING WHICH CURRENTLY ACROSS THE FCA ARE IN
MID 20S TO MID 30S. HWVR TEMPS AT H850 ARE WELL BLO 0C OVER FCA
AND AT 925HPA ARE AS WELL EXCEPT IN THE FAR SOUTHEAST...AND THESE
WILL BE BLO 0C WELL BFE ANY PCPN REACHES US. TEMPS AFTER 12UTC
SHOULD REMAIN COLD ENOUGH FOR ANY PCPN THAT MIGHT REACH SE FCA TO
FALL AS SNOW.

MEANWHILE BANDS OF ECHOES ARE "BLOOMING" ON THE RADAR AND ARE THE
RESULT OF MID LEVEL MOISTENING...YOU HAVE TO GO SOUTH TO THE
DELMARVA REGION TO FIND ANY PRECIP THAT REACHING THE GROUND ATTM. 

DURING THE MORNING CLOUDS WILL CONTINUE TO INCREASE FROM SE TO NW
AND THICKEN AND LOWER AS THIS SYSTEM DEVELOPS AND BEGINS MOVING
NORTHEAST. BY 18UTC THE SFC LOW IS 300 MILES EAST OF HAT...BUT THE
500 HPA TROF IS IN THE CENTRAL APPALACHIANS AND PROVIDING WEAK
UVM TO ALLOW CLOUDS TO SPREAD OVER ENTIRE FCA..AND LIGHT SNOW TO
OVERSPREAD THE AREAS FM I-88 SOUTH AND EAST. EMPHASIS ON LIGHT.

&&

.SHORT TERM /1 PM THIS AFTERNOON THROUGH SUNDAY NIGHT/...
THIS AFTERNOON AND TONIGHT THE FCA ARE RECEIVES A GLANCING BLOW ON
THE BACK EDGE OF THIS STORM SYSTEM. WE ARE ON A TIGHT GRADIENT OF
QPF AND THERE IS STILL CONSIDERABLE SPREAD IN THE MODELS. THE
GEM/GFS ARE ON THE WET SIDE BRINGING THE QUARTER INCH LIQUID EQUIV
LINE AS FAR INLAND AS SE VT/BERKS/COLUMBIA CO/ AND THE CATSKILLS
WITH A HALF INCH IN AS FAR AS SOUTH DUTCHESS AND MUCH OF LITCHFIELD
CO.  THE RGNL GEM IS SLIGHTLY EAST OF THE GFS...BUT THEY ARE IN THE
SAME CAMP.  THE NAM IS CONSIDERABLY DRIER WITH THE TENTH INCH LINE
TO SVT/BERKS/CATSKILLS AND 0.25 IN LITCHFIELD.

MEANWHILE THE 21UTC SREFS PRODUCE NOTHING BUT SPREAD...AT ALB QPF
RANGES FROM A FLAKE TO A HALF INCH. GIVEN THIS AND THE TENDENCY
THAT THE NAM HAS BEEN PRETTY DECENT OF LATE I DON'T QUITE THINK IT
SHOULD BE THROWN OUT ENTIRELY.  WILL DEVELOP QPF AND HENCE SNOW
AMOUNTS FROM 3 WAY BLEND OF GEM RGNL/NAM AND GFS...WHICH IS ALSO
IN LINE WITH WINTER WEATHER DESK AND NOT MUCH DIFFERENCE IN
CURRENT FCST.  WITH POTENTIAL FOR A FEW INCHES IN FAR SOUTHEAST
FCA...WILL ISSUE WWA FOR LITCHFIELD...SOUTHERN BERKSHIRE...EASTERN
OR ALL OF DUTCHESS...WILL REFINE LOCATION AND AMOUNTS BASED ON HOW
QPF FALLS OUT OF GRIDS. WHILE THIS IS BLOW FORMAL ADVISORY
CRITERIA...THIS IS FIRST SIGNIFICANT EVENT AND WILL GO WITH THE
HEADLINE TO HIGHLIGHT THIS.

500HPA TROF MOVES OFFSHORE TONIGHT AND SHUTS THE PRECIPITATION OFF
OVERNIGHT. SFC LOW WELL EAST OF FCA IN N ATLC SUNDAY BUT 500 HPA
TROF CUTS OFF AND STORM DEEPENS AS SFC HIGH PUSHES EAST TWRD RGN
FM OHIO AND TENNESSEE VLY.  CREATES A GRADIENT AND A BREEZY SUNDAY
OVER FCA. RGN IS ON NORTH SIDE OF SFC HIGH. LATE SUNDAY A
SECONDARY FRONT APPROACHES THE SAINT LAWRENCE VALLEY AND DROPS
SOUTH INTO REGION SUNDAY NIGHT. THIS FRONT ALONG WITH SOME WEAK
500HPA SHORT WAVES ACTS A FOCUS FOR CLOUDS TO OVERSPREAD REGION
MAINLY NORTH AND A FOCUS OF LAKE EFFECT -SHSN BAND INTO THE
WESTERN ADIRONDACKS. WHILE CONDITIONS ARE NOT OPTIMAL FOR LAKE
RESPONSE AND BOUNDARY LEVEL WINDS TURN N-NE BEHIND THE FRONT..THEY WILL
BE SUFFICIENT FOR GARDEN VARIETY -SHSN SUN NIGHT IN WESTERN
ADIRONDACKS.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
HIGH PRESSURE SHIFTS EAST INTO THE ATLANTIC AS A CLIPPER TYPE
LOW MOVES FROM THE MIDWEST ACROSS THE EASTERN GREAT LAKES AND
ACROSS THE REGION MONDAY TO OFF NEW ENGLAND BY LATE MONDAY
NIGHT. ONLY A LIMITED AMOUNT OF MOISTURE IS AVAILABLE TO THIS
SUGGESTING AN INCH OR TWO OF SNOW...PERHAPS A BIT MORE WITH
SOME LAKE ENHANCEMENT ACROSS HERKIMER...HAMILTON...MAYBE 
FULTON COUNTIES. THAT IS FOLLOWED BY A BRIEF PAUSE ON TUESDAY
WITH A POSSIBILITY OF SOME LINGERING LAKE EFFECT SNOW ACROSS
THE NORTHWEST PART OF OUR AREA...WHILE FARTHER SOUTH AND EAST
CLOUDS MAY BREAK ENOUGH FOR SOME SUNNY INTERVALS...ESPECIALLY
IN THE MID HUDSON REGION OF NEW YORK. HIGHS TUESDAY WILL RANGE
FROM THE LOW 30S ACROSS THE ADIRONDACKS AND SOUTHERN VERMONT 
TO THE LOW 40S IN THE HUDSON VALLEY SOUTH OF ALBANY. 

MEANWHILE A MUCH STRONGER SYSTEM...SUPPORTED BY AN UPPER TROF...
MOVES FROM THE SOUTHERN ROCKIES TO THE PLAINS ON TUESDAY AND
TO THE MIDWEST TUESDAY NIGHT AS IT DEEPENS. AT THE SAME TIME 
A SURFACE LOW IS FORECAST TO DEVELOP NEAR CAPE HATTERAS. THESE
TWO SYSTEMS WILL BEGIN TO INFLUENCE OUR WEATHER LATE TUESDAY
NIGHT. THE ECM MODEL IS A LITTLE FASTER THAN THE GFS IN 
STARTING THE PRECIP. BOTH MODELS FEATURE A SOUTHEASTERLY 
LOW LEVEL JET WHICH WILL FEED WARMTH AND MOISTURE IN FROM
OFF THE GULF STREAM. THE STORM WILL START OUT AS SNOW...
MIX WITH AND TURN TO RAIN FROM ALBANY SOUTH AND EAST...
THEN TURN BACK TO SNOW AS COLDER AIR RETURNS. THIS STORM 
HAS THE POTENTIAL TO BRING A WARNING CATEGORY SNOWFALL TO
THE REGION FROM THE CATSKILLS...CAPITAL DISTRICT...AND 
BERKSHIRES NORTH...WITH THE HEAVIEST SNOWFALL FROM THE
CENTRAL ADIRONDACKS EAST INTO THE MOUNTAINS OF SOUTHERN
VERMONT. IT WILL ALSO GET QUITE BREEZY STARTING MIDDAY 
THURSDAY...WHICH COULD HAMPER SNOW REMOVAL EFFORTS...AS
THE STORM DEEPENS AND THE GRADIENT INCREASES BETWEEN IT 
AND HIGH PRESSURE OVER THE DEEP SOUTH. MUCH COLDER AIR
WILL BE BROUGHT INTO THE REGION FROM CENTRAL CANADA AS
THE STORM SLOWLY LIFTS NORTHEAST ACROSS THE MARITIMES
THURSDAY NIGHT WITH TEMPERATURES DIPPING INTO THE SINGLES
ACROSS THE ADIRONDACKS...THE LOW 20S IN THE HUDSON VALLEY
     AND THE TEENS ELSEWHERE. FRIDAY WILL BE COLD AND BLUSTERY
WITH LAKE EFFECT SNOW LIKELY FOR THE FIRST PART OF THE DAY
WHICH IS LIKELY TO MIGRATE NORTHWARD AS WINDS SHIFT AROUND
TO SSW BY EVENING...BUT BEFORE THEN WE MAY EXPERIENCE 
LONG LAKE AXIS PARALLEL WINDS...WHICH WOULD BE LIKELY 
TO FORM A BAND EXTENDING INTO HERKIMER...HAMILTON...
FULTON...AND POSSIBLY MONTGOMERY COUNTIES ON FRIDAY. 

FOR THE MOST PART...WE INITIALIZED THE GRIDS WITH GMOS.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
HIGH AND MIDLEVEL CLOUDS HAVE OVERSPREAD THE REGION LAST EVENING
AS A FAST SOUTHERN STREAM FLOW MOVES UP THE EASTERN SEABOARD. 
CLOUDS WILL LOWER FROM SOUTH TO NORTH AFTER DAYBREAK THIS MORNING 
WITH MVFR CIG/VISBY SETTING IN AT KPOU SHORTLY BEFORE NOON WITH 
LIGHT SNOW AND MIST...AT KALB BY EARLY AFTERNOON...AND AT KGFL BY
LATE AFTERNOON. CONDITIONS ARE LIKELY TO DETERIORATE TO IFR SOUTH OF 
ALBANY BY LATE AFTERNOON...THEN IMPROVE SOME LATE IN THE EVENING AS 
THE STORM MOVES AWAY TO THE EAST. CONDITIONS WILL IMPROVE TO VFR 
AROUND 06Z SUNDAY. WINDS WILL BE LIGHT FROM THE NORTH OR CALM
AROUND DAYBREAK...THEN INCREASE TO BETWEEN 5 AND 8 KNOTS BY LATE 
MORNING...AND TO BETWEEN 6 AND 12 KNOTS BY LATE THIS EVENING. 

OUTLOOK...
SUN-TUE...VFR. NO SIG WX.
WED...MVFR. CHC -RASN.

&&

.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED OVER THE NEXT 5 DAYS. RIVERS WILL
CONTINUE TO RECEDE FROM THE RAINFALL THURSDAY WITH SEVERAL DAYS OF
COLD WEATHER. THE MAIN PTYPE WILL BE SNOW FROM THE OCEAN LOW ON
SATURDAY WITH GENERALLY A TENTH TO FOUR TENTHS OF AN INCH OF
LIQUID EQUIVALENT.

A MORE INTENSE STORM WILL AFFECT THE REGION LATE TUESDAY NIGHT
INTO WEDNESDAY NIGHT. THIS STORM WILL BRING A MIX OF SNOW AND 
RAIN TO THE REGION...WITH MOSTLY SNOW FROM THE ALBANY AREA NORTH.
SOUTH OF THE ALBANY AREA THE STORM IS FORECAST TO START AS SNOW
WITH AN INCH OR TWO ACCUMULATION BEFORE IT MIXES WITH AND CHANGES
TO RAIN...WITH TOTALS UP TO AN INCH ACROSS OUR SOUTHERN ZONES. 
THIS WILL BRING ABOUT SIGNIFICANT WITHIN BANKS RISES ON THE 
RIVERS IN THIS AREA...INCLUDING THE LOWER PORTIONS OF THE 
HOUSATONIC ALONG WITH THE STILL...SHEPAUG...AND POMPERAUG
RIVERS IN CONNECTICUT AND THE TENMILE...RONDOUT...AND WAPPINGERS
IN NEW YORK STATE. FARTHER NORTH...AND WEST...THE COMBINATION
OF MORE SNOW AND LESS RAIN WOULD TEND TO RESULT IN LITTLE OR
NO EFFECT ON STREAMFLOWS. 

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...WINTER WEATHER ADVISORY FROM 11 AM THIS MORNING TO 1 AM EST 
     SUNDAY FOR CTZ001-013.
NY...WINTER WEATHER ADVISORY FROM 11 AM THIS MORNING TO 1 AM EST 
     SUNDAY FOR NYZ065-066.
MA...WINTER WEATHER ADVISORY FROM 11 AM THIS MORNING TO 1 AM EST 
     SUNDAY FOR MAZ001-025.
VT...NONE.

&&

$$
SYNOPSIS...SNYDER
NEAR TERM...SNYDER
SHORT TERM...SNYDER
LONG TERM...RCK
AVIATION...RCK
HYDROLOGY...RCK