000
FXUS61 KOKX 212347
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
647 PM EST Tue Nov 21 2023
.SYNOPSIS...
Low pressure will approach tonight, and track across the area on
Wed. High pressure then builds in during Thanksgiving Day and
remains in control through at least the first half of the
weekend. A low pressure system may impact the area Sunday into
Monday.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
-- Changed Discussion --
Updated the forecast for hourly temperatures and precip type,
particularly across Orange County near and north of I-84. Up to
around a half inch of snow has accumulated on colder surfaces as
of 6pm along with spotty freezing drizzle. Temperatures have
been slowly rising here over the past few hours and should
continue to slowly rise over the next couple of hours. Any
wintry precip accumulation from this point on should be minimal,
and a changeover to all rain can be expected by later this
evening.
A broad area of low pres is tracking thru the midwest. This
storm sys will spawn a developing low over near the DELMARVA
tngt, then track the low over the cwa on Wed. The modeling is
clustered very closely with the track of the low, with the
ECMWF, NAM, RGEM, and SREF mean all taking the low over LI.
The low is not progged to get very deep, with the feature around
1005 mb at 15Z per the consensus, but with the tight gradient due to
the high to the NE, there will be a decent wind field ahead of the
low. Based on modeled winds aloft, have issued a wind advy for ern
LI for gusts in the 45-50 mph range. Winds a little less
elsewhere, with gusts around 40 mph coastal areas, dropping to
25-30 mph well nw of NYC.
A wind driven rain is expected late tngt into Wed mrng with peak
winds coming during the period of heaviest rainfall. Again, the
modeling was in good agreement, so went with the WPC QPF. Around 2
inches of rain with the event, most of it falling overnight.
As the low tracks across the region 12-18Z Wed, winds will lighten
and most of the rain will taper off. Could be some lingering
sprinkles or light rain with the passage of the low, but there
should not be much on the back side with a big dry slot coming thru.
There should be some partial clearing late in the day, but
timeheights attm are not overly optimistic with stratus locked in
around 5000 ft.
For temps, based on the track of the low, much of the area expected
to be warm sectored tngt and Wed. Rising temps tngt into Wed, then
plateauing Wed aftn.-- End Changed Discussion --
&&
.SHORT TERM /WEDNESDAY NIGHT/...
Mainly dry wx is expected. There is a low chance that a few
sprinkles could work in from the lakes across the interior zones,
particularly in the first half of the night. The probability was too
low to included in the fcst attm. Otherwise, some caa but lingering
clouds should bring temps into the 30s and low 40s by sunrise. The
NBM looked reasonable under these conditions and was used for the
fcst.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
High pressure builds in during Thanksgiving Day with ridging aloft.
After a breezy start, winds slowly diminish through the rest of the
day. Deterministic NBM has been near the 75th-95th percentile for
high temperatures over the past several runs. With sunny conditions,
some downsloping contribution and 900mb temps progged at 3-4C, have
went with the 95th percentile with a few local adjustments. Highs
generally in the 50s.
High pressure then continues to remain in control through Saturday
with only a weak and dry cold front passing through at some point
late day/early evening Friday. Highs slightly below normal on
Friday, then even colder on Saturday with highs only near 40 in most
spots.
Weak low pressure off the Southeast coast heads north on Sunday,
passing just SE of the 40N/70W benchmark Monday morning. An inverted
trough extending north from the center of the low will bring some
moisture and lift to the forecast area with a chance of rain mainly
Sunday afternoon and night. Looking at GFS and ECMWF, thermal
profiles would support rain, however well north and west could see a
rain/snow mix until at some point perhaps during Sunday night when
thermal profiles warm up.
Likely dry for Monday and Tuesday as the storm heads farther away
east and weak high pressure fills in behind it through Tuesday.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
Low pressure approaches from the southwest tonight. The
low will track across the area Wednesday morning, passing to
the east by afternoon.
Ceilings will continue lowering to MVFR at the start of the
TAF period as rain overspreads the area. Ceilings likely lower
to IFR 03z-05z as the rain becomes moderate. Locally heavy
rainfall is possible overnight. Ceilings should slowly improve
to MVFR Wednesday morning, but may not improve to VFR until
Wednesday evening. There is also a chance for a brief period of
LIFR ceilings at outlying terminals when the low pressure moves
overhead Wednesday morning.
ESE winds will steadily increase through the night, increasing
to 10 to 20 kt with G25-35kt. The highest winds and gusts will
be at coastal terminals. A few gusts could come close to 40 kt
at KJFK, KISP, and KGON. As the low pressure moves across the
area in the morning, winds will diminish and may briefly become
light and variable. Winds then become WNW-NW in the afternoon 10
kt or less, continuing into the evening.
LLWS likely overnight as winds reach 45-50 kt at 2kft.
...NY Metro(KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments likely for lowering flight categories this evening.
Timing of IFR may be delayed by 1-2 hours.
A few gusts overnight, especially at KJFK, could approach 40kt.
Timing of diminish winds Wednesday morning could be off by 1-2
hours. Timing of wind shift to the WNW-NW late Wednesday
morning/early Wednesday afternoon may be off by 1-2 hours.
OUTLOOK FOR 00Z THURSDAY THROUGH SUNDAY...
Wed Night: Chance of MVFR early, then VFR. NW wind gusts 15-20 kt
possible late at night/early Thursday morning.
Thu: VFR with NW winds 10-15 kt with gusts around 20kt. Locally
higher gusts possible.
Fri-Sat: VFR.
Sun: Mainly VFR. Chance of MVFR in showers late.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
-- Changed Discussion --
Gales are still expected tngt into Wed as low pres tracks across LI.
Warnings continue on all waters. Winds will diminish from W to
E during the day Wed, with sca seas lingering on the ocean thru
Wed ngt.
The pressure gradient increases again on Thursday with SCA
conditions on the ocean, and in the morning, possibly on some of the
non-ocean waters as well. Winds and seas diminish through Thursday
night with seas prevailing below 5 ft by Friday morning. Sub-
advisory conditions then continue through Sunday with the exception
of a period of 25kt+ gusts on the ocean Friday night behind a cold
front passage.-- End Changed Discussion --
&&
.HYDROLOGY...
Around 2 inches of rain is expected thru Wed mrng. Rainfall rates in
the mdt to locally hvy range at times. Ponding, as well as some
minor urban and poor drainage flooding, can be expected. Flash
flooding is not expected attm due to a lack of sustained hvy
rainfall rates.
There are no hydrologic concerns Wednesday night through early next
week.
&&
.TIDES/COASTAL FLOODING...
No changes to current headlines with most of the area under a
coastal flood advisory for the early morning high tide cycle
Wednesday. Statements are in effect for New Haven and New
London Counties in CT and Manhattan for a more localized flood
threat.
There will be an increase in surge tonight into Wednesday
morning due to a strengthening SE flow. There is some
uncertainty with the timing of the max surge and how close to
high tide it occurs. Used a blend of ETSS, ESTOFS and the 50th
percentile of the NYHOPS and then added a few tenths in some
locations the higher NYHOPS (Steven`s) guidance due to
increased SE flow lining up closer to the time of high tide.
In addition, wave action across the ocean front and south shore
of CT in conjunction with heavy rain could enhance water levels
some with the potential for localized moderate flooding.
Surge forecasts are mostly in the 2 to 2.5 ft range with some
locally higher surges up to 3 ft. Parts of the South Shore Bays
and Western LI Sound Shorelines have the higher end of the
surge, more in the 2.5 to 3 ft range.
The early Wednesday morning high tide cycle will be the main
tide cycle of concern with regards to coastal flooding as winds
become more westerly for the next high tide cycle. However,
while this will preclude most additional minor coastal flooding,
some residual minor coastal flooding will still be possible
along the south shore backs bays of Nassau and Suffolk during
the time of high tide Wednesday aft/eve. This would most likely
be localized in nature and due to water levels having some
difficulty draining due to a SE swell.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...Coastal Flood Advisory from 5 AM to 11 AM EST Wednesday for
CTZ009-010.
NY...Coastal Flood Advisory from 5 AM to 11 AM EST Wednesday for
NYZ071-073.
Coastal Flood Advisory from 1 AM to 7 AM EST Wednesday for
NYZ074-075-178-179.
Coastal Flood Advisory from 4 AM to 10 AM EST Wednesday for
NYZ078-079-176-177.
Wind Advisory from midnight tonight to 10 AM EST Wednesday for
NYZ079-081.
Coastal Flood Advisory from 3 AM to 9 AM EST Wednesday for
NYZ080-081.
NJ...Coastal Flood Advisory from 1 AM to 7 AM EST Wednesday for
NJZ006-106-108.
MARINE...Gale Warning until 1 PM EST Wednesday for ANZ331-332-340-350-
353.
Gale Warning until 7 AM EST Wednesday for ANZ335-338-345-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...JMC/JC
NEAR TERM...JMC/JC
SHORT TERM...JMC
LONG TERM...JC
AVIATION...DS
MARINE...JMC/JC
HYDROLOGY...JMC/JC
TIDES/COASTAL FLOODING...