FXUS61 KOKX 081337
AFDOKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
837 AM EST TUE DEC 8 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVER THE AREA TODAY...AND THEN SLIDE EAST
OF THE AREA TONIGHT AS STRENGTHENING LOW PRESSURE MOVES ACROSS THE
PLAINS STATES INTO THE MID MISSISSIPPI VALLEY AND GREAT LAKES
REGIONS. A SECONDARY LOW DEVELOPING OVER THE MID ATLANTIC REGION
ALONG AN APPROACHING WARM FRONT WEDNESDAY MORNING WILL PASS
CLOSE TO THE AREA DURING WEDNESDAY AFTERNOON...THEN MOVE INTO NEW
ENGLAND WEDNESDAY NIGHT. HIGH PRESSURE WILL RETURN FOR THE REST OF
THE WORK WEEK...BUT ANOTHER STORM COULD IMPACT THE AREA
THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE WILL BUILD OVER THE AREA TODAY FROM THE WEST.
CLOUDS ASSOCIATED WITH SHORTWAVE PASSING TO THE NORTH MAY THIN
OUT FOR A TIME TODAY...BUT SHOULD AGAIN INCREASE THIS AFTERNOON
AS HIGH/MID LEVEL MOISTURE SPILLS OVER UPPER RIDGE AXIS
APPROACHING WELL IN ADVANCE OF DEVELOPING LOW PRESSURE OVER THE
PLAINS STATES. HIGHS WILL BE A TOUCH BELOW GUIDANCE AND ALSO
SEVERAL DEGREES BELOW NORMAL...BUT CERTAINLY NOT UNUSUAL FOR EARLY
DECEMBER...WITH MID/UPPER 30S WELL INLAND AND LOWER 40S FOR NYC
METRO AND COASTAL SECTIONS.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
ALL ATTENTION THEN TURNS TO THE COMPLEX STORM SYSTEM LIFTING NE
TONIGHT FROM THE PLAINS INTO THE MID MISSISSIPPI VALLEY AND THEN
INTO THE GREAT LAKES REGION...WITH A SECONDARY LOW DEVELOPING OVER
THE MID ATLANTIC REGION BY MORNING. ASSOCIATED PRECIP SHOULD
MOVE IN AFTER MIDNIGHT AND LAST INTO MUCH OF WED...AND P-TYPE
FORECAST WILL BE RATHER CHALLENGING...FIRST DUE TO BOUNDARY LAYER
TEMPS...THEN ALSO AS MID LEVELS WARM UP VIA STRONG S-SW FLOW
ALOFT VERY LATE TONIGHT INTO WED. THE SYNOPTIC HIGH RETREATS NE
TONIGHT...BUT WITH COLD AIR DAMMING REMAINING ACROSS THE
INTERIOR...SO THINK TEMPS INLAND AFTER BOTTOMING OUT IN THE UPPER
20S/LOWER 30S WILL BE SLOW TO RISE LATE TONIGHT/WED MORNING
DESPITE STRENGTHENING EASTERLY FLOW. SO...INITIAL P-TYPE SHOULD
BE SNOW FOR MUCH OF THE INTERIOR...AND RAIN FOR NYC METRO...LONG
ISLAND AND IMMEDIATE COASTAL CT. SEVERAL INCHES OF ACCUMULATING
SNOW ARE EXPECTED LATE TONIGHT...ESPECIALLY FOR INTERIOR PORTIONS
OF THE LOWER HUDSON VALLEY...SO WINTER WX ADVISORIES WILL BE
ISSUED THERE FOR LATE TONIGHT INTO WED MORNING...AND IT IS STILL
POSSIBLE THAT ORANGE AND WESTERN PASSAIC COUNTIES MAY EVENTUALLY
REQUIRE A WINTER STORM WARNING IF PRECIP REMAINS HEAVY ENOUGH
BEFORE WARMING TAKES PLACE AND/OR IF WARMING TAKES PLACE LATER
THAN FORECAST. MEANWHILE...HAVE NOT YET ISSUED ADVISORIES ATTM
FARTHER EAST INTO CT DUE TO LATER TIMING OF PRECIP...PLUS LESSER
CERTAINTY OF BOUNDARY LAYER TEMPS AND THEREFORE AMOUNTS OF FROZEN
AND/OR FREEZING PRECIP.
AS FOR WARMING VERY LATE TONIGHT INTO WED...STILL PREFER COLDER
BOUNDARY LAYER TEMPS PER A NAM/MAV BLEND. GFS MAY BE A LITTLE TOO
QUICK TO WARM UP ALOFT IN THE MORNING DUE TO DYNAMIC COOLING VIA
STRONG LIFT...WHILE NAM MAY BE A LITTLE TOO COLD PER USUAL BIAS...
SO USED A BLEND ALOFT TO GRADUALLY BRING A CHANGEOVER TO MIXED
PRECIP AND THEN RAIN ACROSS THE INTERIOR...WITH A PERIOD OF
FREEZING RAIN POSSIBLE MAINLY ACROSS INTERIOR SOUTHEAST NY.
P-TYPE REMAINS ESPECIALLY UNCERTAIN FOR INTERIOR SOUTHERN CT...
WHERE SFC TEMPS COULD REMAIN COLD ENOUGH TO ALLOW FOR A LONGER
PERIOD OF FROZEN/FREEZING PRECIP IF A COASTAL FRONT SETS UP AND/OR
IF SECONDARY LOW PRESSURE TRACKS FARTHER OFFSHORE THAN EXPECTED.
STAY TUNED.
PRECIP SHOULD WIND DOWN DURING WED AFTERNOON AS THE SECONDARY LOW
PASSES OVER OR JUST SE OF THE AREA. GFS WITH ITS LOW TRACK RIGHT
OVER THE AREA MAY NOT BE KEYING IN ENOUGH ON OFFSHORE BAROCLINIC
ZONE...WHILE NAM MAY NOT KEYING IN ENOUGH ON LAND/SEA TEMP
DIFFERENCE. WESTERLY FLOW SHOULD PICK UP AFTER A COLD FRONTAL
PASSAGE WED EVENING AS THE PRIMARY LOW LIFTS FROM THE UPPER
GREAT LAKES INTO ONTARIO/QUEBEC. WHILE PRESSURE GRADIENT WILL BE
TIGHTENING...BIGGEST PRESSURE RISES AND STRONGEST DOWNWARD MOTION
VIA 500 MB NCVA ARE NOT FOCUSED ON THE AREA...SO THINK WINDS WILL
REMAIN SHY OF ADVISORY CRITERIA. SOME LAKE MOISTURE MAY BE
TRANSPORTED INTO THE AREA AS WELL...WHICH PROBABLY RESULTS IN NOT
MUCH MORE THAN SOME CLOUDS.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
HIGH PRESSURE WILL BUILD INTO THE CWA BEHIND THE DEPARTING LOW....
AND REMAIN THROUGH SATURDAY NIGHT...PROVIDING FAIR AND DRY
CONDITIONS...BUT WITH GUSTY W WINDS CONTINUING THU INTO FRI.
IT WILL BE COOL...WITH HIGHS ONLY REACHING THE UPPER 30S AND
LOWER 40S...WITH OVERNIGHT LOWS FALLING INTO THE TEENS AND 20S.
AN AREA OF LOW PRESSURE MAY IMPACT THE CWA SAT NIGHT INTO
SUNDAY...AND THERE IS SOME DISAGREEMENT AMONG THE FORECAST MODELS
AS TO THE EXACT TRACK THIS LOW TAKE...AND JUST HOW CLOSE IT WILL
COME. FOR NOW WILL CARRY JUST SLIGHT CHANCE POP SAT NIGHT...AND
INCREASE TO CHANCE POP DURING SUNDAY. HIGH PRESSURE SHOULD RETURN
SUNDAY NIGHT INTO MON.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
HIGH PRESSURE BUILDS OVER THE AREA TODAY...WITH A HIGH IMPACT
COASTAL LOW TONIGHT THROUGH WEDNESDAY.
WINDS SHOULD FLUCTUATE BETWEEN 300-330 THROUGH 19Z. AN OCCASIONAL
GUST TO 15-16KT WILL BE POSSIBLE THIS MORNING. EXPECT
MVFR-IFR/PRECIPITATION TO BEGIN WHEN WINDS PICK UP OVERNIGHT. MAINLY
RAIN...THOUGH SNOW AT KSWF AND RASN MIX TO START AT KHPN.
TAF COMMENTS (FORECASTER INSIGHT ON TIMING, CONFIDENCE, TRENDS AND GROUND OPS)
KEWR...NO UNSCHEDULED AMENDMENTS EXPECTED. WIND COMMENTS
ABOVE.
KEWR HOURLY WIND FORECAST
ALL WIND DIRECTIONS ARE TRUE...ADD 13 DEGREES FOR MAGNETIC
08/12Z 30008KT
08/13Z 31008KT
08/14Z 32009KT
08/15Z 33009KT
08/16Z 33007KT
08/17Z 33006KT
08/18Z 33005KT
08/19Z 33005KT
08/20Z 33004KT
08/21Z 32005KT
08/22Z 34004KT
08/23Z 01004KT
KJFK...NO UNSCHEDULED AMENDMENTS EXPECTED. WIND COMMENTS
ABOVE.
KLGA...NO UNSCHEDULED AMENDMENTS EXPECTED. WIND COMMENTS
ABOVE.
KTEB...NO UNSCHEDULED AMENDMENTS EXPECTED. WIND COMMENTS
ABOVE.
KHPN...NO UNSCHEDULED AMENDMENTS EXPECTED. WIND COMMENTS
ABOVE.
KSWF...NO UNSCHEDULED AMENDMENTS EXPECTED. WIND COMMENTS
ABOVE.
KISP...NO UNSCHEDULED AMENDMENTS EXPECTED. WIND COMMENTS
ABOVE.
KBDR...NO UNSCHEDULED AMENDMENTS EXPECTED. WIND COMMENTS
ABOVE.
KGON...NO UNSCHEDULED AMENDMENTS EXPECTED. WIND COMMENTS
ABOVE.
OUTLOOK 06Z WEDNESDAY THROUGH SATURDAY...
WEDNESDAY...MVFR/IFR. STRONG AND VERY GUSTY EAST-NORTHEAST WINDS
INTO THE AFTERNOON. KSWF - SNOW IN THE MORNING CHANGING TO RAIN IN
THE AFTERNOON...WITH A 2-4 HR PERIOD OF SLEET/FREEZING RAIN DURING
THE TRANSITION AROUND MIDDAY. KHPN/KTEB ANY SNOW/RAIN SNOW MIX
CHANGES TO RAIN BY MID MORNING.
WEDNESDAY NIGHT...BECOMING VFR EARLY WITH GUSTY WSW WINDS
DEVELOPING.
THURSDAY-FRIDAY...VFR WITH GUSTY W WINDS.
FRIDAY NIGHT-VFR WITH DIMINISHING WINDS.
SATURDAY...SUB VFR POSSIBLE.
&&
.MARINE...
WILL HOLD OFF ON A SHORT-FUSED SCA FOR THE OCEAN WATERS AS GUSTS AND
SEAS ARE AT SMALL CRAFT LEVELS AS OF 08Z. WITH PRESSURE GRADIENT
RELAXING...FEEL THAT SCA CONDITIONS WOULD NOT LAST TOO MUCH PAST
11Z. WITH ENOUGH CONFIDENCE...HAVE UPGRADED GALE WATCH TO GALE
WARNING ACROSS ALL WATERS...AND EXTENDED THE WARNING ON THE OCEAN
ZONES THROUGH WEDNESDAY NIGHT. SINCE IT WILL BE A QUICK RAMP UP TO
GALE CONDITIONS LATE IN THE TONIGHT PERIOD...HAVE OPTED TO NOT
PRECEDE THE WARNING WITH A SMALL CRAFT ADVISORY WITHIN THE SAME
FORECAST PERIOD. SOUND/HARBOR/BAYS MAY NEED THE GALE WARNING
EXTENDED THROUGH WEDNESDAY NIGHT...BUT NOT ENOUGH CONFIDENCE TO
EXTEND THESE AREAS AT THIS TIME.
WITH A PROLONGED PERIOD OF A TIGHT PRESSURE GRADIENT BETWEEN THE
DEPARTING LOW TO THE NORTHEAST...AND HIGH PRESSURE BUILDING IN FROM
THE WEST...GALES AT LEAST OVER THE OCEAN WATERS MAY LAST ALL THE WAY
THROUGH FRIDAY EVENING. AT THE LEAST...SMALL CRAFT CONDITIONS WILL
OTHERWISE PREVAIL INTO FRIDAY NIGHT. AFTER RELATIVELY QUIETER
CONDITIONS ON SATURDAY...WINDS AND SEAS MAY BUILD AGAIN SATURDAY
NIGHT AND SUNDAY WITH THE POTENTIAL OF A COASTAL STORM AFFECTING THE
REGION.
&&
.HYDROLOGY...
ABOUT 1.5 INCHES LIQUID EQUIVALENT PRECIPITATION IS FORECAST FOR
TUESDAY NIGHT THROUGH WEDNESDAY...WITH LOCALLY HIGHER AMOUNTS
POSSIBLE. MINOR URBAN FLOODING WOULD BE THE MOST LIKELY IMPACT.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST
WEDNESDAY FOR NYZ067>070.
NJ...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST
WEDNESDAY FOR NJZ002.
MARINE...GALE WARNING FROM 3 AM TO 6 PM EST WEDNESDAY FOR ANZ330-335-
338-340-345.
GALE WARNING FROM 3 AM WEDNESDAY TO 6 AM EST THURSDAY FOR
ANZ350-353-355.
&&
$$
