FXUS61 KALY 271543
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
1043 AM EST FRI NOV 27 2009
.SYNOPSIS...
A COMPLEX STORM SYSTEM WILL IMPACT THE NORTHEAST THIS
AFTERNOON INTO SATURDAY WITH UNSETTLED WEATHER INCLUDING RAIN...SOME
SNOW ACROSS THE HIGHER ELEVATIONS...AND STRONG GUSTY WINDS. THE
STORM WILL MOVE INTO THE CANADIAN MARITIMES SATURDAY INTO
SUNDAY...WITH HIGH PRESSURE BUILDING IN FROM THE SOUTHEAST WITH
DIMINISHING WINDS AND TRANQUIL WEATHER.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HAVE UPDATED THE GRIDS TO ACCOUNT FOR LATEST T/TD OBS AND TRENDS.
REGIONAL RADAR MOSAIC SHOWS STEADY LIGHT RAIN ACROSS OUR NEW
ENGLAND COUNTIES...BUT THIS RAINFALL IS MAKING LITTLE WESTWARD
PROGRESS. AT THE SAME TIME...LIGHT PRECIP ACROSS CNY DUE TO PVA
ROTATING AROUND THE UPPER LOW ACROSS ONTARIO IS DRYING UP AS IT
APPROACHES OUR WESTERN ZONES. THE RESULT HAS BEEN LITTLE PRECIP
ACROSS THE MAJORITY OF THE CWA...INCLUDING THE CAPITAL REGION...SO
HAVE LOWERED POPS IN THESE AREAS THROUGH THE MID AFTN. HAVE ALSO
LOWERED POPS TO CHC FOR THE SOUTHERN CATSKILLS FOR THE LATE
AFTN/EVE HOURS...AS THE LATEST 12 UTC NAM...AS WELL AS
EXTRAPOLATING LATEST RADAR RETURNS...SHOWS LITTLE PRECIP FOR THE
SOUTHERN CATSKILLS FOR LATER TODAY.
PRECIP WILL MAINLY BE IN THE FORM OF RAIN EARLY AS TEMPS ARE
HOLDING FROM THE MID 30S TO LOWER 40S. HOWEVER...PRECIP WILL BEGIN
TO TRANSITION TO SNOW ACROSS ELEVATIONS GREATER THAN 1500 FEET BY
THIS EVENING AS COLDER AIR WORKS INTO THE REGION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
FOR TONIGHT...THE FREEZING LEVEL CONTINUES TO LOWER AND MOST IF NOT
ALL OF THE FA WILL SEE A CHANGEOVER TO SNOW AS LOW DEEPENS TO
BETWEEN 970 AND 980 HPA SOMEWHERE BTWN DOWNEAST MAINE AND
NORTHEAST PORTIONS OF THE CANADIAN MARITIMES...BUT BY THIS TIME
THE QPF ACRS FA IS DECREASING RAPIDLY WITH QPF AMOUNTS GENERALLY A
TENTH TO A QUARTER OF AN INCH. THUS ACCUMULATING SNOWS APPEAR TO
BE LIMITED TO GENERALLY 1 TO 3 INCHES MAINLY ACROSS THE NORTHERN
MOUNTAINS. THE ONE CERTAINTY FOR FRIDAY NIGHT IS THAT CONDITIONS
WILL BECOME VERY WINDY ACROSS FA AND PRESSURE GRADIENT APPEARS TO
TIGHTEN EVEN FURTHER WITH SUBSEQUENT MODEL RUNS. ISALLOBARIC
COUPLET CONTINUES TO BE IMPRESSIVE WITH +6 TO -8 ON NAM AND +4 TO
-13 ON GFS AT 12Z SATURDAY. IN ADDITION 0-30 MB AGL WINDS CONTINUE
TO STRENGTHEN WITH NAM NOW INDICATING FLAGS ABOVE 50 KTS ACRS MUCH
OF THE EASTERN CATSKILLS AS WELL AS PORTIONS OF THE SOUTHERN
ADIRONDACKS...BERKSHIRES AND SOUTHERN GREEN MOUNTAINS BETWEEN 06Z
AND 18Z SAT. IT LOOKS AS THOUGH THESE AREAS WILL SEE GUSTS OVER
58 MPH AND HAVE ISSUED A HIGH WIND WARNING FROM 6 PM THIS EVENING
UNTIL 6 PM SATURDAY FOR THESE AREAS. ELSEWHERE MOST AREAS LOOK TO
HAVE GUSTS OVER 40 KNOTS...SO HAVE ISSUED A WIND ADVISORY FOR THE
REMAINING ZONES FOR THE SAME TIME PERIOD. ALSO CONCERNED ABOUT
CHANNELED FLOW IN E-W ORIENTED VALLEYS SUCH AS THE MOHAWK AND
CATSKILL CREEK DRAINAGE...BUT HAVE NOT INCLUDED THESE AREAS IN THE
WARNING AT THIS TIME...BUT THEY WILL NEED TO BE MONITORED CLOSELY.
ON SATURDAY...THE LOW BECOMES VERTICALLY STACKED AND OCCLUDED
OVER NORTHERN PORTIONS OF THE CANADIAN MARITIMES WITH STRONG
PRESSURE GRADIENT STILL IN PLACE ACROSS MUCH OF FA UNTIL LATE IN
THE DAY WHEN IT STARTS TO SLACKEN. HIGHER MIXING HEIGHTS OVER 3
KFT IN SOME AREAS EXIST SATURDAY MORNING THAN TONIGHT WHICH WILL
GIVE WINDS AN EVEN BETTER CHANCE TO MIX DOWN. ANY LINGERING PCPN
WILL BE TAPERING OFF BY AFTERNOON. LOW LEVEL WIND FIELDS WILL
STILL BE STRONG ESPECIALLY DURING THE MORNING...BUT EXPECT SOME
SUBSIDENCE/DOWN SLOPING DURING THE AFTERNOON. ANY UPSLOPE SNOW
LOOKS TO BE CONFINED TO THE NORTHERN PORTIONS OF THE SOUTHERN
ADIRONDACKS AND THE SOUTHERN GREEN MOUNTAINS. HIGHS WILL BE IN THE
MID 30S TO MID 40S.
ON SATURDAY NIGHT...ANY LINGERING SNOW SHOWERS EXPECTED TO BE
CONFINED TO THE NORTHERN HALF OF THE FA WITH THE SNOW ENDING LAST
ACROSS THE WESTERN ADIRONDACKS WHERE A LITTLE LAKE ENHANCEMENT IS
POSSIBLE. FOR NOW WILL JUST GO WITH CHANCE POPS. LOWS SATURDAY
NIGHT EXPECTED TO BE IN THE MID 20S TO LOWER 30S.
SUNDAY...LOOKS DRY AS HIGH PRESSURE BUILDS INTO FA WITH HIGHS IN
THE UPPER 30S TO AROUND 50 AND MUCH LESS WIND. CLOUDS WILL
INCREASE AGAIN ESPECIALLY DURING THE AFTERNOON AHEAD OF THE NEXT
SHORT WAVE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
TRENDS IN THE GLOBAL MODELS AND FORECASTER DISCUSSIONS CONTINUE TO
FAVOR A FRONTAL PASSAGE ON MONDAY. HOWEVER...QUESTIONS REMAIN JUST
HOW EXTENSIVE THE PRECIP SHIELD WILL BE AND DID NOT WANT TO GO
LIKELY POPS AT THIS TIME. IN ADDITION...THERE ARE TRENDS POINTING
TOWARD MORE ANAFRONT CHARACTERISTICS AS MAIN UPPER JET REMAINS
BEHIND THE SURFACE FRONTAL ZONE. EITHER WAY...BAROCLINICITY
INCREASES SUNDAY NIGHT INTO MONDAY FROM THE TENNESSEE AND OHIO
VALLEY INTO NEW ENGLAND. THERMAL PROFILES REMAIN A CHALLENGE AS
THIS ROUND OF THE MODEL SUITES SUGGEST MAINLY SNOW FOR THE DACKS
WITH A RAIN/SNOW LINE ACROSS THE MOHAWK RIVER AND CAPITAL REGION
WITH MAINLY RAIN SOUTH AND EAST OF CAPITAL REGION. A FEW INCHES OF
SNOW ARE POSSIBLE BUT WILL AWAIT CONTINUED TRENDS BEFORE
HIGHLIGHTING THIS POTENTIAL INTO THE HWO THIS MORNING.
IN THE WAKE OF THE FRONTAL PASSAGE...COLD ADVECTION COMMENCES WITH
AVERAGE 850MB TEMPS DROPPING TOWARD -10C. THIS WILL BE SURE TO
ACTIVATE LAKE ONTARIO FOR ADDITIONAL LAKE EFFECT SNOW FOR PORTIONS
OF THE DACKS AND MOHAWK VALLEY. GLOBAL MODELS DIVERGE FROM HERE AS
ECMWF SHORT WAVE ENERGY EITHER DIGS A BIT AND MOVES ACROSS THE
REGION OR THE GFS IDEA OF A FLATTER WAVE. IT SEEMS...WHATEVER MOVES
THROUGH THE FLOW...THIS LEADS INTO A PERIOD OF WARM ADVECTION FOR
THE MID WEEK PERIOD WITH THE CHANCE FOR A LITTLE OVERRUNNING
EVENT.
THEN CUT OFF 4-CORNERS CONUS LOW EJECTS INTO TEXAS AND GULF OF
MEXICO LATER IN THE WEEK. AS ONE WOULD EXPECTED...A VARIETY OF
SOLUTIONS AND WE WILL ONLY PLACE SLIGHT CHANCE POPS AT THIS TIME.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
IFR CONDITIONS PREVAIL THIS MORNING...ESPECIALLY WITH RESPECT TO
RADIATIONAL FOG WHICH HAS RESULTED IN 1/4SM VIS WHICH WILL CONTINUE
FOR THE NEXT COUPLE OF HOURS. AS SEEN ON THE RADAR
MOSAIC...REFLECTIVITIES COVERAGE REMAINS OVER CENTRAL NY AND
ADDITIONAL SHOWER ACTIVITY COMING NORTHWARD INTO ADJACENT WESTERN
NEW ENGLAND. AS THIS STORM CONTINUES TO INTENSIFY OFF THE MID
ATLANTIC COAST...PRECIPITATION WILL INCREASE IN COVERAGE THROUGH
THIS FRIDAY MORNING KEEPING MVFR/IFR CONDITIONS WHICH SHOULD BE
MAINLY FROM CIGS.
WINDS WILL BECOME MORE PROBLEMATIC LATE TODAY INTO TONIGHT WITH AN
INCREASED WEST-NORTHWEST WIND FLOW. WILL CONTINUE WITH LLWS TONIGHT
WITH SFC WIND GUSTS BETWEEN 25-35 KTS TO START.
OUTLOOK...
SAT-SAT NGT...MVFR/IFR...-SHRA CHG TO -SHSNRA. LLWS. WINDY.
SUN...VFR. NO SIG WX.
SUN NT-MON...MVFR/IFR. -RA/-SN.
TUE...VFR/MVFR. CHC -SHRA/-SHSN.
&&
.HYDROLOGY...
WIDESPREAD PRECIPITATION EXPECTED FROM TODAY THROUGH SATURDAY...AS
A STRONG STORM IS EXPECTED TO IMPACT THE REGION. THERE IS STILL A
HIGH AMOUNT OF UNCERTAINTY WITH REGARDS TO THE EVOLUTION OF THE
STORM AND ASSOCIATED QPF. QPF AMOUNTS LOOK TO BE SOMEWHERE FROM
JUST BELOW A HALF INCH TO JUST OVER AN INCH AND FOR NOW HAVE
HIGHEST AMOUNTS ACROSS NORTHERN PORTION OF HSA. DEPENDING ON HOW
THE STORM EVOLVES...SOME OF THE PRECIP MAY FALL AS SNOW AS
WELL...ESPECIALLY ACROSS THE HIGHER ELEVATIONS. AT THIS TIME IT
APPEARS SOME RISES OF AROUND 1 TO 2 FEET WILL OCCUR ON RIVERS BUT
THEY SHOULD REMAIN WELL WITHIN THEIR BANKS. THE PRECIPITATION WILL
START TO TAPER OFF BY SATURDAY AFTERNOON AS THE STORM PULLS AWAY
INTO THE CANADIAN MARITIMES. WEAK HIGH PRESSURE IS EXPECTED TO
RESULT IN DRY CONDITIONS ON SUNDAY.
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...WIND ADVISORY FROM 6 PM THIS EVENING TO 6 PM EST SATURDAY FOR
CTZ001-013.
NY...HIGH WIND WARNING FROM 6 PM THIS EVENING TO 6 PM EST SATURDAY
FOR NYZ033-042-047-051-058-063-082.
WIND ADVISORY FROM 6 PM THIS EVENING TO 6 PM EST SATURDAY FOR
NYZ032-038>041-043-048>050-052>054-059>061-064>066-083-
084.
MA...HIGH WIND WARNING FROM 6 PM THIS EVENING TO 6 PM EST SATURDAY
FOR MAZ001-025.
VT...HIGH WIND WARNING FROM 6 PM THIS EVENING TO 6 PM EST SATURDAY
FOR VTZ013-014.
WIND ADVISORY FROM 6 PM THIS EVENING TO 6 PM EST SATURDAY FOR
VTZ015.
&&
$$
SYNOPSIS...FRUGIS/11
NEAR TERM...FRUGIS
SHORT TERM...11
LONG TERM...BGM
AVIATION...BGM
HYDROLOGY...11
