000
FXUS61 KOKX 171804
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
104 PM EST Sun Dec 17 2023
.SYNOPSIS...
Strong low pressure approaches from the south today and passes
through during Monday. In the wake of the exiting low, high
pressure builds in from the west through Wednesday, remaining in
place through late week.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Bands of light rain have been moving into and through portions
of the region this morning. Despite the shallow low level
moisture drizzle has not been observed, and are now mentioning
light rain.
Shallow moisture deepens through the day with ESE winds.
Isentropic lift was producing light rain. Mild conditions today
with highs in the mid 50s, which is about 10 degrees above
normal.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
Low pressure approaches from the south tonight as it deepens.
Models are still trying to resolve where the center of this
storm will be be by the time it gets near us - depicting a broad
storm center with two separate circulations. There`s at least
agreement that the northern circulation will likely pass through
the western half of the forecast area Monday morning, with the
southern circulation moving through the eastern half of the
forecast area Monday afternoon as it tries to merge with the
other. This will maintain the likelihood of rain into Monday
afternoon for most spots.
Rainfall could be heavy at times after early this evening into
Monday with anomalously high moisture for this time of year. It will
combine with strong lift from a low level jet and upward forcing in
the vicinity of both circulations. With elevated instability,
isolated thunder is still a possibility tonight through early Monday
afternoon. CAMs reflectivity forecast continue to show this
convective potential. No changes to the flood watch - see the
hydrology section below for more details.
As for strong winds, 925mb winds are still progged at 60-85kt along
with 55-70kt at 950mb over coastal sections late tonight into Monday
morning. Still looks like the low level inversion will be neutral to
weak, so thinking there`s potential for 60-70% of the 925mb winds to
mix down to the surface, especially in the heavier downpours. High
wind watches have now been upgraded to warnings. Wind advisories
remain unchanged from the previous forecast and are posted through
Monday morning. There remains a chance of advisory-level gusts
Monday afternoon with deeper mixing on a SW-W wind flow, but this
probably won`t last too long and didn`t have have enough confidence
to expand the advisory in time. Also did not have the confidence to
expand advisories westward based on progged track of the
aforementioned northern circulation by most models. NBM
probabilities of advisory and warning thresholds being met continue
to rise over the past few days, although feel that the warning
threshold probabilities are too low.
Mild for Monday with highs near 60 - approaching records for the
date in some areas. Winds subside Monday night, but remaining
on the breezy side. There will be a chance of showers after
midnight as a closed 500mb low approaches from the west and
another low pressure center is generated offshore.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
As surface low pressure exits well to the north, the parent upper
trough axis pivots through the area on Tuesday. While there will
be little remaining moisture, cyclonic curvature and frictional
effects in the lower levels may lead to a few lingering rain or
snow showers into the afternoon. Noticeably colder conditions
settle in as a blustery NW flow helps to advect in a colder air
mass and adds to the chill. Though highs get into the low to mid
40s Tuesday afternoon, apparent temps likely remain in the 30s for
much of the day.
Relaxing pressure gradient into midweek will allow winds to subside
by Wednesday, and a much drier regime develops in the system`s wake
as a strengthening surface high builds east. Ridging remains in
place through late week, maintaining dry, tranquil conditions, with
temperatures pretty close to normals.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
-- Changed Discussion --
HIGH IMPACT AVIATION EVENT TONIGHT INTO MONDAY...
Deepening low pressure tracks up the East Coast through Monday.
MVFR to IFR conditions across the area terminals through this
afternoon/evening. Widespread IFR tonight, possibly LIFR, with
steady rain developing toward 00Z Mon.
Easterly flow around 10 to 15 kt with gusts up to 20 kt through
this evening. Winds steadily ramp up tonight after 03Z Monday,
with strongest winds after 06Z Monday. SE winds increasing to
20-30kt G35-55kt, strongest along the coast. Slow improvement
late Monday morning through the afternoon, with winds gradually
decreasing in the afternoon and into the evening. Winds become
S/SW Monday morning then shift around to the west after 22z,
with showers also tapering off.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
The afternoon haze potential forecast at KEWR is YELLOW, which
implies slant range visibility 4-6SM outside of cloud.
IFR cigs possible into early afternoon with drizzle or mist.
Gusts today may be more occasional than frequent.
Isolated 50+ kt gusts late tonight into Monday morning, especially
at KJFK and KLGA.
OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
Monday: IFR, possibly LIFR in rain early. Isolated thunderstorm
possible in the morning. LLWS through the morning. SE winds
20-30kt gusting 35-50 kt before 15Z, strongest along the coast,
becoming S then SW to W diminishing late Monday afternoon and
night.
Tuesday: Chance of flurries mainly north and west of the NYC
terminals early, then a few rain or snow showers possible along the
coast during the afternoon. MVFR, possibly IFR, especially in any
snow showers. WNW G20-25kt in the afternoon.
Wednesday through Friday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Wind gusts on the non-ocean waters, especially near shore, have
increased to near 25 kt, and with winds and gusts increasing
have now issued a SCA for the non-ocean waters through this
afternoon. Otherwise, marginal SCA conditions continue on the
ocean waters.
Winds and seas then ramp up tonight into Monday. The Storm
Warning continues for all waters tonight through Monday
morning. Best chance of storm force winds will be late tonight
through the first half of Monday morning. Thereafter, gales
should prevail in the afternoon. Ocean seas peaking roughly in
the 16-21 ft range with 5-10 waves on Long Island Sound. Winds
should fall below 25kt by the end of Monday night, however seas
will remain elevated above 5 ft on the ocean.
In the wake of exiting low pressure, NW flow on Tuesday may continue
to produce gusts upwards of 25 kt on most waters, before subsiding
Tuesday night. High pressure allows more tranquil winds mid to late
week, though ocean seas will remain elevated, at or above 5 ft
through Friday.
&&
.HYDROLOGY...
A total of 2 to 4 inches of rainfall is expected through Monday
afternoon, with most of this falling from late evening tonight
through Monday morning. Locally higher amounts are possible, and the
greater amounts are expected to fall generally north and west of
NYC. Widespread minor urban/poor drainage/river flooding can be
expected with localized to scattered flash flooding possible.
Moderate river flooding is becoming more probable for small rivers
and streams in NE NJ and the Lower Hudson Valley, and there`s even
at least a chance that major flooding occurs over the typically
quick-responding rivers in NE NJ.
Otherwise, no hydrologic issues expected mid to late next week.
&&
.TIDES/COASTAL FLOODING...
Coastal flood warnings issued for southern Queens, southern and
eastern portions of LI and coastal CT as widespread moderate
coastal flooding is likely with the daytime high tide cycle on
Monday. There is potential for locally major flood thresholds
to be reaches for southern Queens, SW LI and twin forks, if
windshift occurs near or after the time of high tide. Elsewhere
minor to moderate coastal flood potential is increasing, where
coastal flood watches have been issued. This includes the
tidally affected rivers, particularly Hudson and Hackensack
rivers, where the surge is favored to be forced upstream by the
strong southerly flow.
Peak surge of 3 1/2 to 5 ft will likely be between high tidal
cycles Monday morning. A later timing of windshift closer to
the early Monday afternoon time of high tide will be critical to
the potential for major flood thresholds to be reached or
exceeded. There is still spread in exact storm track and
intensity as it moves up the coast. A track more to the west
and/or slower would place the area more squarely under the
strongest winds and increase the threat for locally major
coastal flooding for the most vulnerable southern Queens, SW and
E LI portions of the area. A more easterly and/or farther east
track would lessen the threat. More clarity on these scenarios
likely over the next 24 hrs.
In addition, heavy rainfall and/or runoff coinciding with the
Sunday Night and Monday afternoon high tides will exacerbate
street and property flooding issues along the coast and tidally
affected rivers.
Along the ocean beachfront, potential exists for 12+ ft
breakers Sunday overnight into Monday, which combined with
elevated water levels, will likely result in widespread dune
erosion and scattered overwashes.
Finally, minor coastal flooding possible with tonight`s high
tide mainly for southern Queens, SW LI and coastal Westchester
and SW CT.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Flood Watch from 5 PM EST this afternoon through Monday
afternoon for CTZ005>007-009>011.
Wind Advisory from midnight tonight to noon EST Monday for
CTZ005>007.
High Wind Warning from midnight tonight to noon EST Monday for
CTZ008>012.
Coastal Flood Warning from 10 PM this evening to 6 PM EST
Monday for CTZ009>012.
NY...Flood Watch from 5 PM EST this afternoon through Monday
afternoon for NYZ067>075-176-178.
Wind Advisory from midnight tonight to noon EST Monday for
NYZ071>074.
High Wind Warning from midnight tonight to noon EST Monday for
NYZ075-078>081-176>179.
Coastal Flood Warning from 10 PM this evening to 6 PM EST
Monday for NYZ071.
Coastal Flood Watch from 9 PM EST this evening through Monday
afternoon for NYZ074-075.
Coastal Flood Watch from 10 PM EST this evening through Monday
afternoon for NYZ073-078-176-177.
Coastal Flood Warning from 11 PM this evening to 6 PM EST
Monday for NYZ079-081.
Coastal Flood Warning from 9 PM this evening to 6 PM EST
Monday for NYZ080-178-179.
NJ...Flood Watch from 5 PM EST this afternoon through Monday
afternoon for NJZ002-004-006-103>108.
Wind Advisory from midnight tonight to noon EST Monday for
NJZ006.
Coastal Flood Watch from 9 PM EST this evening through Monday
afternoon for NJZ006-104-106-108.
MARINE...Small Craft Advisory until 6 PM EST this evening for ANZ331-
332-335-338-340-345-350-353-355.
Storm Warning from 6 PM this evening to 1 PM EST Monday for
ANZ331-332-335-338-340-345-350-353-355.
&&
$$
SYNOPSIS...JC/MET
NEAR TERM...JC/MET
SHORT TERM...JC/MET
LONG TERM...JP
AVIATION...20
MARINE...JC/MET
HYDROLOGY...JC