176
FXUS61 KOKX 272027
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
327 PM EST Wed Nov 27 2024
.SYNOPSIS...
-- Changed Discussion --
High pressure continues to shift offshore tonight. A low pressure
system will impact the area on Thanksgiving Day. The low departs to
the northeast Thursday and we will then be in between broad low
pressure to our northeast and a polar high building into the
Mississippi and Tennessee Valleys through mid next week.-- End Changed Discussion --
&&
.NEAR TERM /THROUGH THURSDAY/...
-- Changed Discussion --
High pressure is now offshore to our south and will continue to move
east through tonight. Heights will rise aloft a bit early tonight in
response to an approaching digging trough. Light winds expected
overnight, with winds becoming southerly around midnight and then
southeasterly. Plenty of cloud cover will be around ahead of the
next system, so lows will be in the mid 30s to low 40s.
A low pressure system will impact the area on Thanksgiving Day. The
low approaches from the southwest under a shortwave embedded in
a broader upper level trough. The low will deepen as it tracks
over the area. There is now great agreement across the global
guidance and CAMs that the low moves directly over the area,
from NYC and northeastward through southern CT. This supports a
warmer overall solution. This will be an all rain event for most
of the area, with rain starting after midnight, becoming
widespread and moderate by Thanksgiving morning and then
tapering off in the late afternoon. A storm total of about 0.75
to 1.00 inches is expected. Rates are expected to remain under
0.25 in/hr for most, but isolated instances of 0.50 in/hr are
possible. No flooding is expected. With this track now farther
north, a rumble of thunder can not be ruled out over the Twin
Forks or eastern CT with the potential for very weak
instability.
Snow or a rain/snow mix is still possible across the far northern
interior of the Lower Hudson Valley and northeast NJ at the onset.
Given how marginal surface temps are, any accumulation will likely
be confined to far northwestern Orange County. Forecast
accumulations are mainly under or around an inch. A changeover to
all rain for these areas is expected by noon.
With the low moving overhead, there will likely be increasing winds
and gusts Thanksgiving morning, followed by a bit of a lull period
into the afternoon. The strongest winds will then happen behind the
low, with sustained winds late Thursday afternoon about 15 mph with
gusts 25 to 30 mph.-- End Changed Discussion --
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
-- Changed Discussion --
Dry conditions are expected by Thanksgiving Night as the low is
progged to be in the Gulf of Maine by then. The area will then be in
between broad low pressure to our northeast and a polar high
building into the Mississippi and Tennessee Valleys. A breezy NW-W
flow will usher in a drier and colder airmass to the area through
the Short Term period. Highs on Friday will be in the 40s and Friday
night most places will fall below freezing. With 10 to 15 mph winds
Friday night, wind chill values will be down in the teens and low
20s.-- End Changed Discussion --
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
A longwave upper trough will dominate over eastern North America
through the period, with a continental polar air mass moving in as
high pressure slowly builds southeast from the Plains states toward
the Southeast, and weak sfc troughing remaining E of the Mid
Atlantic. Temperatures will be generally 5-10 degrees below the
seasonal average through the period, and a W-NW flow will dominate,
becoming gusty at times during the day. Wind chills should run about
7-10 degrees colder than air temperatures at times, bottoming out in
the teens/lower 20s each night and top out from the mid 20s to lower
30s each daytime.-- End Changed Discussion --
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
-- Changed Discussion --
Low pressure approaches tonight, impacting the terminals on
Thanksgiving.
VFR until around 09z. Conditions will then quickly lower to MVFR in
developing rain with IFR quickly following through day break and the
rest of Thanksgiving morning. There is a chance of some wet snow
mixed in at the onset at KSWF, but no accumulation is expected.
Conditions will remain IFR to start the afternoon before improving
to MVFR as the low pressure departs to the east, with VFR likely
towards sunset.
W-SW winds will begin weakening this evening. Light and variable
winds expected after 00z will then transition to an increasing NE-E
flow early Thanksgiving morning.
Lower confidence wind direction forecast after 15z due to some
uncertainty on the track of the low pressure. Winds may become more
SE or even S for a time if the low tracks just north of NYC and
coastal terminals. However, winds likely remain NE-E if the low
tracks just south of the terminals. Once the low passes east in the
afternoon, winds will shift to the W-NW and become gusty 20-25k.
...NY Metro (KEWR/KLGA/KJFK/KTEB)TAF Uncertainty...
Timing of lower flight categories and onset of rain may be off by 1-
2 hours late tonight/early Thanksgiving morning.
Amendments likely to wind direction forecast mid to late
Thanksgiving morning into early afternoon, which is highly dependent
on the track of the low pressure.
OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...
Thursday Afternoon-Night: Rain with IFR conditions to start, then
gradually improving conditions to MVFR and then VFR late in the day
and evening. Winds become WNW-NW late in the afternoon and evening,
gusting 20-25 kt.
Friday: VFR. W-WSW wind gusts 15-20 kt.
Saturday-Sunday: VFR. W wind gusts 20-25 kt.
Monday: VFR. NW wind gusts 15-20 kt.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
-- Changed Discussion --
Quiet conditions are expected on the waters tonight with high
pressure in control. Winds and waves ramp up Thanksgiving morning as
low pressure is set to impact the area. Between about 7am and 11am
the low will be centered just to our southwest and winds will be
SE/E and start to increase as the low deepens. There will then
likely be a 2-3 hour period where the low is overhead and winds will
actually weaken a bit. The highest winds are expected when the low
is northeast of the area. This is when W/NW winds will be sustained
20 to 25 knots with gusts 25 to 30 knots. Gusts could occasionally
gust up to 35 knots over the ocean waters. Winds fall below SCA
criteria likely by Friday morning. A SCA is now in effect for the
ocean waters, the South Shore Bays, Peconic and Gardiners Bays and
the eastern Sound from 10am Thursday until 6am Friday. All other
waters, the SCA is in effect from 1pm Thursday until 4am Friday.
With the area in a tight pressure gradient as high pressure builds
in through the weekend, gusty conditions continue. Mainly below SCA,
but conditions could be marginal SCA on the ocean waters by Friday
night.
Marginal SCA cond likely on all ocean waters Sat into Sat night,
with seas up to 5 ft and wind gusts up to 25 kt. These cond could
linger on the outer waters E of Fire Island Inlet into Sunday. Cond
on Monday will only be just below SCA criteria on the ocean, with
gusts up to 20 kt and seas up to 4 ft. Cond on the non ocean waters
will also not be too far behind from Sat through Mon, with gusts up
to 20 kt.-- End Changed Discussion --
&&
.HYDROLOGY...
-- Changed Discussion --
Low pressure will bring 0.75 to 1.00 inches of rain to the area on
Thanksgiving Day over a 12 to 18 hour period. No hydrologic impacts
are expected.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 1 PM Thursday to 4 AM EST Friday for
ANZ331-335-338.
Small Craft Advisory from 10 AM Thursday to 6 AM EST Friday
for ANZ332-340-345-350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...BG/JT
NEAR TERM...JT
SHORT TERM...JT
LONG TERM...BG
AVIATION...DS
MARINE...BG/JT
HYDROLOGY...BG/JT