FXUS61 KALY 101737
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
1237 PM EST THU DEC 10 2009

.SYNOPSIS...
AN AREA OF DEEP LOW PRESSURE OVER THE EASTERN GREAT LAKES...
WILL MOVE NORTHEAST ACROSS EASTERN CANADA THROUGH TODAY. WHILE
ANOTHER AREA OF DEEP LOW PRESSURE ALONG THE NEW ENGLAND COAST
MOVES TOWARD THE CANADIAN MARITIMES. STRONG AND GUSTY WESTERLY
WINDS WILL DEVELOP ACROSS THE REGION WILL CONTINUE INTO
SATURDAY USHERING IN A COLD AIR MASS. AS THE COLDER AIR MOVES
ACROSS THE RELATIVELY WARMER WATER OF LAKE ONTARIO...LAKE EFFECT
SNOW WILL DEVELOP OVERNIGHT AND CONTINUE INTO EARLY SATURDAY
IMPACTING THE WESTERN ADIRONDACKS. SIGNIFICANT SNOWFALL IS
EXPECTED.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1145 AM EST...QUICK UPDATE WITH WELL ESTABLISHED LAKE BAND OFF
LAKE ONTARIO WITH A 255-260 LOW LEVEL TRAJECTORY. BAND IS
IMPACTING LOCATIONS NORTH OF ROUTE 28 IN EXTREME NRN HERKIMER AND
EXTREME NW HAMILTON COUNTIES. CURRENT FORECAST HANDLES THIS
FEATURE WELL WITH LAKE EFFECT SNOW WARNING CONTINUING. SNOW RATES
COULD EXCEED 2 INCHES AN HOUR OCCASIONALLY WITH 35+DBZ RETURNS OFF
KTYX.

FURTHER SOUTH...WE HAVE SEEN SOME LAKE ERIE LAKE RETURNS IMPACTING
THE MOHAWK RIVER VALLEY...NRN REACHES OF THE CAPITAL REGION...AND
SRN VT. THE ACTIVITY IS MORE CELLULAR/DIFFUSE NOW...BUT WE
INCREASED THE POPS TO HIGH CHANCE AND LIKELY VALUES NORTH OF THE
CAPITAL REGION...ACROSS THE HIGHER TERRAIN OF SRN VT...AND WEST
DOWN THE MOHAWK RIVER VALLEY. WE INCREASED TO SLIGHT CHANCE AND
LOW CHANCES FURTHER SOUTH. WE INCREASED THE WIND GUSTS TO 35-40
MPH BASED ON BUFKIT PROFILES...AND GROUND TRUTH FROM THE CAPITAL
REGION NORTH AND WEST.

TEMPS LOOK ON TRACK WITH MAXES IN THE 20S ACROSS THE MTNS...AND
LOWER TO MID 30S ELSEWHERE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
THE MAIN EVENT THIS PERIOD WILL BE THE LAKE EFFECT SNOW EVENT
NOSING INTO THE SOUTHERN ADIRONDACKS. THE BAND WILL AFFECT EXTREME
NORTHERN HERKIMER AND HAMILTON COUNTIES TODAY AND INTO
TONIGHT. AS MEAN WIND FLOW GRADUALLY TURNS MORE WESTERLY TONIGHT
THROUGH TOMORROW NIGHT...THE BAND WILL GRADUALLY SHIFT SOUTH. BY
SATURDAY MORNING THE WINDS WILL DIMINISH AND TURN MORE
NORTHWEST...AND SOME SCATTERED SNOW SHOWER ACTIVITY COULD THEN
PUSH THROUGH THE ENTIRE MOHAWK VALLEY...INCLUDING THE CAPITAL
DISTRICT DURING THE DAY SATURDAY.  

BASED ON THE PREDICTED INSTABILITY AND MOISTURE...SOME LOCALIZED
AREAS IN HERKIMER AND HAMILTON COUNTIES WILL PROBABLY NEED A
YARD/METER STICK TO MEASURE THE SNOW BY SATURDAY MORNING. THE LAKE
IS RELATIVELY WARM...AND BOUNDARY LAYER AIR WILL BE SO
COLD...-12C AND COLDER...INSTABILITY WILL BE IMPRESSIVE...AND IDEAL
DENDRITIC GROWTH SHOULD OCCUR. INLAND PENETRATION OF THE BAND INTO
HAMILTON COUNTY IN QUESTION...BUT WILL MONITOR REAL-TIME TRENDS
AND LATEST DATA AS IT HAPPENS. FOR NOW...SUGGESTING BAND NOSES
WELL INTO HAMILTON COUNTY...BUT AGAIN...PERIODIC ADJUSTMENTS MAY
BE NECESSARY THROUGHOUT THE EVOLUTION OF THIS LAKE EFFECT SNOW
EVENT.

OUTSIDE OF THE LAKE EFFECT BAND...MOSTLY CLOUDY TO CLOUDY SKY
SHOULD PREVAIL...WITH AGAIN...SOME INTERVALS OF BREAKS DUE TO SOME
LOCALIZED DOWNSLOPING IN THE VALLEYS. IT WILL BE BREEZY TO
WINDY...WITH SOME GUSTS IN HIGHER ELEVATIONS AND CHANNELED VALLEYS
OVER 40 MPH THIS AFTERNOON AND FRIDAY AFTERNOON. EVEN AT
NIGHT...THE WINDS SHOULD NOT DIMINISH TOO MUCH...AND SOME GUSTS
SHOULD EXCEED 35 MPH LOCALLY. THE CORE OF THE STRONGEST WINDS IS
PREDICTED TO BE NORTH AND WEST OF OUR REGION...SO WITH SOME GUSTS
JUST BELOW ADVISORY CRITERIA THROUGH FRIDAY...NO WIND HEADLINES
AT THIS TIME...BUT IT WILL BE CLOSE.

WITH HIGHS IN THE 20S MANY AREAS FRIDAY...AND LOWS TONIGHT AND
FRIDAY NIGHT IN THE TEENS TO LOWER 20S...SINGLE NUMBERS IN
MOUNTAINS...THE ADDED GUSTY WINDS WILL MAKE IT REALLY FEEL LIKE
WINTER. HIGH PRESSURE BUILDS IN ON SATURDAY AND WINDS DIMINISH...
WITH THE POTENTIAL LAKE EFFECT SNOW SHOWER ACTIVITY POSSIBLE
PUSHING THROUGH THE MOHAWK VALLEY. SOME WEAK WARM ADVECTION ALSO
BEGINS LATER SATURDAY. HIGHS SATURDAY IN THE 20S TO LOWER 30S. FOR
NOW JUST ISOLATED SNOW SHOWERS IN FORECAST...UNTIL EVOLUTION OF
LAKE EFFECT BAND CAN BE SEEN FRIDAY AND FRIDAY NIGHT.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
SUN/SUN NT...BOTH THE 00Z/10 ECMWF AND GFS DEPICT A POTENTIAL 
INTERACTION BETWEEN A NORTHERN STREAM SHORTWAVE APPROACHING FROM THE 
W...AND A SOUTHERN STREAM FEATURE PASSING E FROM THE OH VALLEY 
TOWARD THE MID ATL COAST. AT THIS TIME...BOTH MODELS INDICATE LITTLE 
IF ANY INTERACTION BETWEEN THE TWO. HOWEVER...GIVEN PAST HISTORY OF 
DISTURBANCES WITHIN THE SOUTHERN STREAM TRACKING FURTHER N THAN 
INITIALLY INDICATED BY MODELS...WILL NEED TO WATCH THIS CLOSELY...AS 
THERE IS SOME POTENTIAL FOR AT LEAST MOISTURE FROM THE SOUTHERN 
STREAM FEATURE TO BECOME ENTRAINED NORTHWARD. AT THIS TIME...WILL 
INDICATE CHC FOR SNOW SHOWERS ACROSS THE ENTIRE REGION. 
OTHERWISE...EXPECT MAX TEMPS TO GENERALLY REMAIN IN THE LOWER/MID 
30S WITHIN VALLEYS...AND 20S ACROSS THE HIGHER TERRAIN...WITH MINS 
SUN NT/MON AM MAINLY IN THE 20S...EXCEPT FOR TEENS ACROSS THE 
WESTERN DACKS.

MON-MON NT...SOME LINGERING SNOW SHOWERS ARE POSSIBLE EARLY 
MON...OTHERWISE WILL INDICATE MAINLY CHC POPS ACROSS FAR NW AREAS 
WHERE ADDITIONAL LAKE EFFECT IS POSSIBLE. EXPECT MAXES TO REACH THE 
MID/UPPER 30S IN VALLEY REGIONS...EXCEPT POSSIBLY THE LOWER 40S 
WITHIN THE MID HUDSON VALLEY...WITH OVERNIGHT MINS MON NT/TUE AM 
MAINLY IN THE 20S.

TUE-WED NT...A SERIES OF NORTHERN STREAM /CLIPPER LIKE/ DISTURBANCES 
MAY PRODUCE SOME LIGHT SNOW/SNOW SHOWERS TUE...ESP ACROSS NORTHERN 
AREAS...WHERE CHC POPS ARE INDICATED. OTHERWISE...MAINLY SLIGHT CHC 
POPS. EXPECT TEMPS TO FALL BELOW SEASONAL LEVELS...ESP TUE NT INTO 
WED.

&&

.AVIATION /18Z THURSDAY THROUGH MONDAY/...
WITH THE LAKE EFFECT MACHINE IN FULL SWING BEHIND WEDNESDAY'S 
SYSTEM...GFL AND ALB CAN EXPECT FLURRIES TO ABOUND.  BKN-OVC CIGS 
THROUGHOUT THE PERIOD SHOULD BE IN MAINLY THE 4000-5000 FOOT RANGE.  
THE HEAVIEST SNOWS WILL BE WEST OF GFL THROUGH THE OVERNIGHT INTO 
FRIDAY.  BUT...WE HAVE A TEMPO FOR BARELY MVFR UNTIL 22Z TODAY JUST 
IN CASE A BAND OR TWO SHOULD MEANDER ITS WAY AS FAR EAST AS THE 
AIRPORT.  OTHERWISE...WE ARE LOOKING AT VFR CONDITIONS FOR 
ALL...WITH NO FOG ISSUES.  WIND SHEAR WILL ALSO NOT BE AN ISSUE... 
WITH RELATIVELY STRONG WESTERLY WINDS AT THE SURFACE...AND HIGHEST 
WINDS AT THE 2000-FOOT LEVEL ONLY AROUND 40 KNOTS.

OUTLOOK...
FRI PM-SAT...WINDY.  VFR...CHC MVFR AT GFL IN LAKE EFFECT -SHSN.
SAT NGT-SUN...VFR...NO SIG WX.
SUN NGT-MON...MAINLY VFR...CHC -SHSN.

&&

.HYDROLOGY...
WE WILL STAY COLD ENOUGH FOR LITTLE OR NO SNOW MELT.
OTHERWISE...NO HYDRO PROBLEMS ARE FORESEEN FOR THE NEXT WEEK.

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...LAKE EFFECT SNOW WARNING UNTIL 7 AM EST SATURDAY FOR NYZ032-
     033.
MA...NONE.
VT...NONE.

&&

$$
SYNOPSIS...NAS/WASULA
NEAR TERM...WASULA 
SHORT TERM...NAS 
LONG TERM...KL 
AVIATION...ELH
HYDROLOGY...KL/NAS