FXUS61 KOKX 101927
AFDOKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
227 PM EST THU DEC 10 2009
.SYNOPSIS...
HIGH PRESSURE BUILDS INTO THE REGION THROUGH SATURDAY...AND MOVES
OFFSHORE SATURDAY NIGHT INTO SUNDAY. LOW PRESSURE PASSES TO THE
SOUTH SUNDAY NIGHT INTO MONDAY. ANOTHER LOW PRESSURE SYSTEM MAY
AFFECT THE REGION DURING THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD ADVECTION CONTINUES BEHIND A DEPARTING COLD FRONT TO THE EAST.
A GUSTY DOWNSLOPING WEST WIND SHOULD OFFSET ANY LAKES MOISTURE THAT
HEADS THIS WAY. SHOULD BE A PARTLY CLOUDY/MOSTLY SUNNY DAY. HIGH
TEMPS ACROSS MOST SPOTS HAVE ALREADY OCCURRED EARLY THIS MORNING.
WITH 900 MB TEMPS FORECAST TO DROP TO -8C DURING THE AFTERNOON...AND
CONSIDERING SOME COMPRESSIONAL HEATING VIA DOWNSLOPING...TEMPS ARE
EXPECTED TO BE ONLY IN THE 30S DURING THE AFTERNOON.
LOOKS LIKE WINDS WILL BE JUST SHORT OF ADVISORY CRITERIA...SO
WILL NOT ISSUE ANY ADVISORIES AT THIS TIME.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
COLD AIR CONTINUES TO POUR INTO THE REGION TONIGHT. EVEN WITH BREEZY
CONDITIONS...LOWS WILL STILL MANAGE TO RANGE FROM THE LOW 20S IN THE
CITY TO 10 TO 15 ACROSS THE NORTHERN TIER OF SUBURBS. PREFERRED THE
COLDER NAM MOS FOR LOWS WITH SOME DOWNWARD TWEAKS WHERE SNOW PACK
WILL LIKELY REMAIN. WILL ALLOW DAY SHIFT TO REASSESS THREAT OF
ADVISORY CRITERIA WINDS TONIGHT AS WINDS AT THE TOP OF THE MIXED
LAYER MAY BE JUST STRONG ENOUGH TO WARRANT AN ISSUANCE.
PLENTY OF SUNSHINE AND BREEZY AGAIN FOR FRIDAY...BUT COLDER THAN
NORMAL. 900 MB TEMPS FORECAST TO FALL TO -13C IN THE AFTERNOON. EVEN
CONSIDERING SOME COMPRESSIONAL HEATING AGAIN....HIGHS WILL PRIMARILY
BE IN THE 20S. SIDED WITH THE NAM MOS WITH DOWNWARD TWEAKS AGAIN.
THE AIR MASS MODERATES A LITTLE ON SATURDAY...BUT AT THE SAME
TIME...THE DEPTH OF THE BOUNDARY LAYER SHRINKS WITH SUBSIDENCE FROM
STRONGER HIGH PRESSURE. HIGHS ONLY 30 TO 35 WITH SUNNY SKIES AND
DIMINISHING WINDS.
GFS IS THE ONLY MODEL WHICH DEPICTS HIGH PRESSURE CENTER TO THE EAST
OF 70W WHILE THE REST OF THE GUIDANCE INCLUDING THE GFS ENSEMBLE
MEAN HAS IT POSITIONED OVER OR SOUTH OF SOUTHERN NEW ENGLAND. WILL
THEREFORE OPT FOR A SLOWER ARRIVAL OF MOISTURE ASSOCIATED WITH AN
APPROACHING SHORTWAVE...WITH PERHAPS SOME SURFACE REFLECTION IN THE
FORM OF AN INVERTED TROF EXTENDING NORTH FROM LOW PRESSURE
DEVELOPING TO THE SOUTH. WILL LIMIT POPS TO THE AFTERNOON HOURS AND
KEEP PRECIP TYPE SIMPLE THIS FAR OUT...WITH A RAIN/SNOW MIX NORTH OF
THE CITY AND RAIN ELSEWHERE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
SOME UNCERTAINTY REMAINS IN THE LONG TERM. THERE IS SOME MODEL
CONSENSUS HOWEVER THAT A WEAK LOW WILL PASS TO THE SOUTH WITH
PERHAPS AN INVERTED TROF EXTENDING NORTH TOWARDS THE REGION. IT
APPEARS CLOSE ENOUGH TO KEEP IN A CHANCE OF PRECIP. LOOKS LIKE RAIN
FOR THE CITY AND ISLAND...AND MIXED RAIN AND SNOW ELSEWHERE. AFTER A
SLIGHT CHANCE OF LINGERING PRECIP MONDAY MORNING...WEAK HIGH
PRESSURE BUILDS IN WITH DRY WEATHER MONDAY AND MONDAY NIGHT.
MODELS THEN DIFFER IN HOW NORTHERN AND SOUTHERN STREAM ENERGY IS
HANDLED...BOTH IN TIMING AND PHASING (OR LACK OF). WHERE AND WHEN
RESULTANT LOW PRESSURE TRACKS IS THEREFORE UNCERTAIN...MAKING
TUESDAY AND WEDNESDAY A LOW CONFIDENCE FORECAST. ECMWF AND GGEM
CONTINUE TO FAVOR A WEAKER AND MORE PROGRESSIVE NORTHERN STREAM LOW
AFFECTING THE AREA ON TUESDAY...WHILE THE GFS AND PARALLEL GFS ARE
TRENDING TOWARDS A STRONGER COASTAL LOW DEVELOPING TO OUR SOUTH AND
PASSING OVER (PARALLEL) OR EAST OF THE 40/70 BENCHMARK WEDNESDAY
MORNING. WILL THEREFORE LEAVE THIS PART OF FORECAST AS IS WITH
SLIGHT CHC TO CHC POPS THROUGH THE PERIOD AND MIXED PRECIP TYPE.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
THE POLAR JET WILL REMAIN ANCHORED OVER THE NYC METRO AREA THRU FRI.
STRONG W WINDS WILL THEREFORE CONTINUE WITH VFR CIGS/VSBY.
TAF COMMENTS (FORECASTER INSIGHT ON TIMING, CONFIDENCE, TRENDS AND GROUND OPS)
KEWR...OCNL GUSTS TO 40 KT AFT 23Z. PREVAILING WINDS/GUSTS
MAY BE NEED TO BE INCREASED IN TAF AFT 00Z TO ABOUT 27025G35KT IF
WEAK INVERSION FAILS TO BE A LIMITING FACTOR.
KEWR HOURLY WIND FORECAST
ALL WIND DIRECTIONS ARE TRUE...ADD 13 DEGREES FOR MAGNETIC
10/18Z 28022G30KT
10/19Z 28022G31KT
10/20Z 28021G31KT
10/21Z 28020G31KT
10/22Z 27019G32KT
10/23Z 27019G36KT
11/00Z 27019G37KT
11/01Z 27020G37KT
11/02Z 27020G36KT
11/03Z 27021G35KT
11/04Z 27021G34KT
11/05Z 28020G33KT
KJFK...OCNL GUSTS TO 40 KT AFT 23Z.
KLGA...OCNL GUSTS TO 40 KT AFT 23Z.
KTEB...OCNL GUSTS TO 35 KT AFT 23Z.
KHPN...PREVAILING WINDS/GUSTS MAY BE NEED TO BE INCREASED IN
TAF AFT 00Z IF WEAK INVERSION FAILS TO BE A LIMITING FACTOR.
KSWF...PREVAILING WINDS/GUSTS MAY BE NEED TO BE INCREASED IN
TAF AFT 00Z IF WEAK INVERSION FAILS TO BE A LIMITING FACTOR.
KISP...PREVAILING WINDS/GUSTS MAY BE NEED TO BE INCREASED IN
TAF AFT 00Z IF WEAK INVERSION FAILS TO BE A LIMITING FACTOR.
KBDR...PREVAILING WINDS/GUSTS MAY BE NEED TO BE INCREASED IN
TAF AFT 00Z IF WEAK INVERSION FAILS TO BE A LIMITING FACTOR.
KGON...PREVAILING WINDS/GUSTS MAY BE NEED TO BE INCREASED IN
TAF AFT 00Z IF WEAK INVERSION FAILS TO BE A LIMITING FACTOR.
OUTLOOK 00Z SAT THROUGH TUE...
FRI NGT...VFR. WINDS DIMINISHING LATE TO 15-25KT.
SAT...HI PRES BUILDS NWD OVER THE REGION WITH 15-25KT WINDS
DIMINISHING BY EVE.
SUN...VFR WITH LGT WINDS IN THE MRNG. LOW PRES BRINGS CHC FOR MIXED
PCPN TO RA COAST WITH SN TO A MIX INTERIOR LATE SUN INTO SUN NGT.
MVFR OR LWR POSSIBLE.
MON...PERIODS OF MVFR POSSIBLE.
TUE...SUB VFR POSSIBLE AS LOW PRES APPROACHES.
&&
.MARINE...
STEEP LOW LEVEL LAPSE RATES AND DOWNWARD MOTION WILL ALLOW A FAIR
AMOUNT OF MOMENTUM TRANSPORT FROM ALOFT BEHIND DEPARTING COLD FRONT.
WESTERLY GALES ARE THEREFORE EXPECTED ON THE OCEAN WATERS AND
EASTERN LONG ISLAND SOUND THROUGH AT LEAST FRI AND QUITE POSSIBLY
INTO FRI NIGHT. THINK OTHER WATERS WILL ALSO SEE GALES ESPECIALLY
NEAR SHORE THROUGH TONIGHT...BUT CERTAINTY WANES THEREAFTER. AT ANY
RATE...SCA CONDITIONS ARE LIKELY TO CONTINUE THEREAFTER ON ALL
WATERS THROUGH SAT...AND POSSIBLY INTO SAT NIGHT E OF MORICHES INLET
AS WINDS AND SEAS THERE WILL BE SLOWER TO SUBSIDE.
OCEAN SEAS ARE CURRENTLY RUNNING UP TO 3 FT HIGHER THAN WAVEWATCH...
AND EXPECT THIS WILL REMAIN THE CASE THROUGH SAT NIGHT GIVEN STRONG
W FLOW. THIS WILL YIELD MAINLY 10-14 FT SEAS TODAY AND ABOUT 9-12 FT
TONIGHT THROUGH FRI...THEN SLOWLY DIMINISHING SAT INTO SAT NIGHT.
SEAS COULD ALSO BUILD AS HIGH AS 8-9 FT IN PORTIONS OF EASTERN LONG
ISLAND SOUND TONIGHT INTO FRI EVENING.
WE ARE STILL DEALING WITH RESIDUAL STORM SURGE ON LONG ISLAND
SOUND...SO IT APPEARS QUITE UNLIKELY THAT WATER LEVELS WILL DROP TO
LOW WATER ADVISORY CRITERIA OF 1.8 FT BELOW MLLW...AND THE CURRENT
ADVISORY WILL BE CANCELED. STRONG WESTERLY FLOW COULD EVENTUALLY DO
THE TRICK FOR LATER LOW TIDE CYCLES ESPECIALLY ON WESTERN LONG
ISLAND SOUND...AND WE WILL MONITOR MAGNITUDE OF NEGATIVE DEPARTURES
TODAY BEFORE DECIDING ON ANY ADVISORIES FOR TONIGHT.
HIGH PRESSURE WILL BUILD OVER THE WATERS ON SUNDAY...WITH QUIET
CONDITIONS. A COMPLEX SCENARIO WILL THEN UNFOLD FROM SUNDAY NIGHT
THROUGH WED. A WARM FRONT WILL IMPACT THE WATERS DURING THE FIRST
PART OF THE PERIOD...WITH A COLD FRONT FOLLOWING BY WED.
BETWEEN THESE TWO SYSTEMS...THE DEVELOPMENT OF LOW PRESSURE OVER THE
REGION IS POSSIBLE. EXPECT PERIODS OF SCA CONDITIONS...WITH GALES
POSSIBLE IF THE LOW DEVELOPS.
&&
.HYDROLOGY...
DRY WEATHER OVER THE NEXT FEW DAYS WILL ALLOW ANY RIVERS/STREAMS
TO RECEDE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...GALE WARNING UNTIL 6 AM EST FRIDAY FOR ANZ335-338-345.
GALE WARNING UNTIL 6 PM EST FRIDAY FOR ANZ330-340-350-353-355.
&&
$$
SYNOPSIS...JC
NEAR TERM...JC/PW
SHORT TERM...JC
LONG TERM...JC
AVIATION...JMC
MARINE...BG
HYDROLOGY...JC
