FXUS61 KOKX 050254
AFDOKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
954 PM EST FRI DEC 4 2009
.SYNOPSIS...
HIGH PRESSURE TONIGHT GIVES WAY TO LOW PRESSURE TRACKING UP THE
EASTERN SEA BOARD SATURDAY AND SATURDAY NIGHT. HIGH PRESSURE
RETURNS ON SUNDAY AND SLIDES OFFSHORE ON MONDAY. A WEAK COLD FRONT
MOVES ACROSS THE AREA MONDAY EVENING...FOLLOWED BY ANOTHER AREA OF
HIGH PRESSURE. A COMPLEX STORM SYSTEM THEN AFFECTS THE AREA FOR
MIDWEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
CURRENT FORECAST FOR OVERNIGHT ON TRACK. TEMPS/DEWS IN A FEW
PLACES WERE OFF BY A FEW DEGREES...SO UPDATED THOSE TO BE MORE
REFLECTIVE OF CURRENT CONDITIONS. OTHERWISE...CLOUDS CONTINUE TO
INCREASE IN THE MID AND UPPER LEVELS EVIDENT BY THE WATER VAPOR
AND VISIBLE SATELLITE IMAGES AS LOW PRESSURE EJECTS FROM THE GULF
OF MEXICO. WITH THE INCREASING PRESSURE GRADIENT AND CANOPY OF
CLOUDS SLATED TO ARRIVE OVERNIGHT DO NOT EXPECT TEMPS TO DROP MORE
THAN 10-15F FROM AFTERNOON READINGS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
SURFACE LOW RIDES UP THE E COAST SAT...ALTHOUGH ANOMALIES FROM
THE ENSEMBLES ARE LOW /-1 STD/ THIS SYSTEM WILL BRING DECENT WINDS
AND NEARLY A HALF INCH OF RAINFALL. BIGGEST CHALLENGE IS THE
PRECIPITATION TYPE AS THIS WILL BE THE FIRST SNOWFALL OF THE
SEASON FOR THE TRI-STATE. HIGH CONFIDENCE IN RAIN AT THE ONSET
WITH A CHANGE OVER TO WET SNOW DURING THE AFTERNOON ACROSS ORANGE
COUNTY AND HIGHER ELEVATIONS. FARTHER E...A MIX WITH AND CHANGE
OVER TO SNOW IN NYC IS FORECAST DURING THE LATE AFTERNOON / EARLY
EVENING TIME FRAME. MEDIUM CONFIDENCE IN THE FORECAST FOR THE
METRO AREA.
WITH SFC TEMPS IN THE M-U 30S AND DEWPOINTS IN THE L30S LOOK FOR WET
BULB TEMPS TO STAY IN THE MID 30S. MODELS INDICATE AT BANDED PRECIP
OVER NYC AND LI...BUT THIS OCCURS WHEN THE ATMOSPHERE SUPPORTS
RA. THIS EQUATES TO HIGHEST RAINFALL AMOUNTS ACROSS LI. ANY SNOW
ACCUMULATION WILL BE CONFINED TO GRASSY SURFACES NW OF NYC WITH AN
INCH OR LESS PREDICTED. NYC/LI/NERN NJ/AND COASTAL CT NO SNOW
ACCUMULATION IS FORECAST AT THIS TIME DUE TO THE WARM GROUND. ROAD
TEMPERATURES REMAIN WARM SO HIGH CONFIDENCE IN NO SNOW
ACCUMULATION ON ROADS.
PRECIPITATION TAPERS OFF SATURDAY NIGHT FROM SW TO NE AS THE
SURFACE LOW MOVES NORTHEAST. BY THE PREDAWN...ALL AREAS WILL BE
DRY WITH THE POTENTIAL FOR SLICK BRIDGES AND OVERPASSES WHERE
TEMPERATURES FALL BELOW FREEZING AND ROAD SURFACES ARE WET.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
INITIAL TROUGH AND SFC LOW DEPARTS AS ZONAL FLOW PREVAILS. GENERAL
TROUGH BEGINS TO DIG ACROSS THE MID WEST BY MID WEEK WHICH AMPLIFIES
THE RIDGE OVER THE EAST. THIS RIDGE GETS KICKED OUT AS THE TROUGH
MOVES EASTWARD. UPPER LOW CLOSES OFF TO OUR NORTH BY THE END OF THE
WEEK AS COLDER AIR RETURNS.
HIGH PRESSURE BUILDS TO THE SOUTH SUNDAY...THEN PASSES OFF THE COAST
SUNDAY NIGHT AND MONDAY. DRY THIS TIME FRAME...WITH NEAR TO SLIGHTLY
BELOW NORMAL TEMPS EXPECTED. WEAK TROUGH AND ASSOCIATED SFC LOW MOVE
ACROSS THE REGION MONDAY NIGHT AND EARLY TUESDAY. LITTLE QPF WITH
THIS SYSTEM AS MOISTURE LACKING AND LIFT LOOKS WEAK. NEXT HIGH
BUILDS TUESDAY INTO WEDNESDAY. MUCH STRONGER STORM THEN APPROACHES
AHEAD OF AFOREMENTIONED UPPER TROUGH BY WEDNESDAY AND WEDNESDAY
NIGHT. PRIMARY LOW PASSES ACROSS GRTLKS REGION REMAINING TO THE
WEST...AND THIS HAS BEEN A CONSISTENT GLOBAL MODEL SOLUTION FOR
SEVERAL RUNS NOW. AS SUCH...WARMER SCENARIO EXPECTED...BUT SOME SNOW
INCLUDED IN GRIDS DUE TO SFC TEMPS. WOULD NOT BE SURPRISED IF LESS
SNOW IS INCLUDED IN THE FORECAST AS WE GET CLOSER TO THE STORM. STAY
TUNED.
BEHIND THE LOW...GUSTY SW TO W WINDS EXPECTED WITH COLDER TEMPS TO
END THE WEEK. WINDS BEGIN TO ABATE LATER FRIDAY.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
VFR THROUGH AT LEAST 14Z. MODERATE TO HIGH CONFIDENCE OF ONSET OF
RAIN/MVFR CONDS AT AREA TERMS BETWEEN 15Z AND 18Z...EARLIEST AT
SOUTHERN TERMS. PROFILES LOOK TO BE COLD ENOUGH AT THE START OF
PRECIP TO BE -SN AT KSWF. EXPECT CHANGEOVER TO -SN AT ALL TERMS
BEFORE PRECIP ENDS...BUT TIMING IS TRICKY THIS FAR OUT. IT COULD
BE AN HOUR OR TWO EARLIER OR LATER THAN WHAT IS FORECAST.
WINDS WILL VEER TO THE RIGHT OF 310 AT NYC TERMS BETWEEN 02Z AND
04Z...BUT SPEEDS REMAIN BLO 10KT UNTIL SAT MORNING.
OUTLOOK 00Z SAT THROUGH WED...
SAT NIGHT...IFR/LIFR IN SNOW...IMPROVING AFT MIDNIGHT.
SUN-TUE...VFR.
WED...SUB-VFR...WIND/RAIN
&&
.MARINE...
WINDS AND SEAS PICK UP SATURDAY AS LOW PRESSURE APPROACHES SO SCA
HOISTED FOR ALL AREAS. THE SURFACE LOW DEEPENS AS IT PASSES AND
WITH THE TIGHTER PRESSURE GRADIENT...WINDS COULD REACH GALES OVER
THE OCEAN SATURDAY NIGHT. HOISTED A GALE WATCH FOR THE
AFOREMENTIONED OCEAN ZONES WITH AN SCA CONTINUING FOR THE HARBOR AND
BAYS SATURDAY NIGHT.
WINDS DIMINISH ALLOWING SEAS TO SUBSIDE SUNDAY...THEN TRANQUIL
CONDITIONS EXPECTED ACROSS THE AREA WATERS SUNDAY NIGHT THROUGH
TUESDAY. CONDITIONS DETERIORATE WEDNESDAY AS MUCH STRONGER STORMS
APPROACHES.
&&
.HYDROLOGY...
A 1/4 TO 1/2 INCH OF LIQUID EQUIVALENT IS POSSIBLE WITH A COASTAL
LOW PRESSURE SYSTEM SATURDAY AND SATURDAY NIGHT. HIGHEST AMOUNTS
WILL BE ACROSS SE CT AND EASTERN LONG ISLAND...SOME OF THAT IN
THE FORM OF SNOW. NO HYDROLOGIC IMPACT IS EXPECTED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM SATURDAY TO 6 AM EST SUNDAY
FOR ANZ330-335-338-340-345.
GALE WATCH FROM SATURDAY EVENING THROUGH LATE SATURDAY NIGHT
FOR ANZ350-353-355.
SMALL CRAFT ADVISORY FROM 10 AM TO 6 PM EST SATURDAY FOR
ANZ350-353-355.
&&
$$
