okx-afd on 2024-11-26

251
FXUS61 KOKX 261219
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
719 AM EST Tue Nov 26 2024

.SYNOPSIS...
-- Changed Discussion --After a frontal passage today, the next system to impact the
area will be low pressure on Thanksgiving. The low lifts up
into the Canadian Maritimes on Friday, getting absorbed into a
much broader area of low pressure over eastern Canada this
weekend into early next week. At the same time, polar high
pressure over the Northern Plains builds southeast into the
Mississippi and Tennessee Valleys.-- End Changed Discussion --

.NEAR TERM /THROUGH WEDNESDAY/...
-- Changed Discussion --Leading edge of showers working into western portions of the
Lower Hudson Valley and interior NE NJ. There are also some
patched of light rain out ahead of the main band.

Low pres was centered E of Lake Huron this mrng, with a cold
front extending roughly swd thru PA and WV. Rain will overspread
the forecast area today, exiting in the aftn with the fropa.
It should be dry with rapidly clearing skies by sunset at the
latest. Went with the NBM for temps, although there is some
concern the initial wrmfnt may not clear all of CT. If this
turns out to be the case, potential for a 10 degree bust on
highs there.

With mainly skc tngt, the only thing holding back temps is the
wly component wind. Stuck with the NBM for now, but if
decoupling occurs expect colder numbers particularly outlying
areas.

Subtropical Pacific tap produces thickening mid and high clouds
on Wed. Good chance that it will be ovc by late aftn. No pcpn
however with subsidence and dry llvls. Temps close to climo.-- End Changed Discussion --

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
The models continue to converge on a Thanksgiving soln for the
next area of low pres to impact the cwa. The 00Z ECMWF and GFS
follow a similar track and timing, taking the low over or near
the cwa 12-18Z. The ECMWF is stronger and slightly further N,
whereas the weaker lows in the GEM, GFS, and NAM are better
clustered. The fcst follows the same thinking, with pcpn
breaking out late Wed ngt, lasting into Thanksgiving and
tapering off in the eve, if not earlier. Based on the current
track, primarily rain with some snow mainly interior at the
onset. Any swd shift in the track would bring more snow. Kept
temps closer to the 2m raw model blend numbers with pcpn and
clouds keeping things colder, especially interior. The low draws
colder air into the area Thu ngt as the pcpn ends, and the NBM
was used for lows.

.LONG TERM /FRIDAY THROUGH MONDAY/...
**Key Points**

*Much colder air begins to arrive on Friday and will ultimately lead
to well below normal temperatures to end Meteorological Fall and
beginning of Meteorological Winter.

The combination of a polar vortex across eastern Canada and a broad
upper trough amplifying across the eastern U.S, will send an
anomalously cold airmass into the region this weekend into early
next week. Highs and lows during this period will be about 7 to 10
degrees below normal. Once we get past the warmest day Friday (3 to
5 degrees below normal), highs are forecast to be in the upper 30s
to lower 40s, with lows mainly in 20s. Used the National Blend of
Models (NBM). Box and whisker plots not showing much range between
the 25th and 25th percentiles. The breezy westerly flow during
this time period will make it feel even colder with apparent
temperatures dropping into the teens during the nighttime hours.

As for precipitation, it looks generally dry. NBM pops show low
chances for precipitation across coastal area Friday afternoon and
night, and again on Sunday. Aired on the drier side and undercut NBM
PoPs. The chances seems to be partly related to the GEFS and EPS
members overdoing the area of cold advection precipitation over the
waters, but there are also multiple amplifying shortwaves during
this time, the most noticeable being on Sunday. Any development of
low pressure looks to be well offshore at this time.

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --Low pressure passing to our north will push a warm front through the
area this morning, quickly followed by a cold frontal passage
late morning/early afternoon. High pressure will then builds in
from the west tonight into Wednesday.

Expect a period of MVFR/IFR this morning with showers along and
ahead of an approaching cold front. Becoming VFR behind the cold
front, but MVFR may linger 1-2 hours.

Winds E/SE 5-10kt to start will become SW 10-15kt this morning
following a warm frontal passage, then WNW 10-15kt G20-25kt
behind the cold front. Winds subside this evening. Gusts will
linger the longest at the coastal terminals.

...NY Metro (KEWR/KLGA/KJFK/KTEB)TAF Uncertainty...

Amendments are likely through about 19Z with changing ceiling
categories and wind shifts as multiple fronts pass through the
area.

OUTLOOK FOR 12Z WEDNESDAY THROUGH SATURDAY...

Wednesday: VFR.

Wednesday night: Chance of rain with MVFR late, except chance
rain/snow at KSWF.

Thursday: Rain with IFR cond likely, possibly a rain/snow mix early
at KSWF. E-NE winds G20kt in the afternoon, becoming NW at night.

Friday: VFR. NW winds G20kt.

Saturday: VFR. W winds G20-25kt.

Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --

.MARINE...
Winds increase ahead of the cdfnt today, with a sca remaining
in effect on the ocean. All areas likely to hit sca criteria
behind the fropa this aftn into tngt. A sca is in effect. Cond
improve on Wed, then a sca is likely for Thanksgiving with low
pres tracking near the waters. There remains a chc for gales
with the sys, but the latest data suggests this prob is too low
to include in the hwo attm.

A tight pressure gradient between low pressure across eastern Canada
and high pressure to the southwest will produce a prolonged period
of westerly flow at 20 to 25 kt. Seas on the ocean are forecast to
range from 3 to 6 ft during this time, highest in the waters east of
Moriches Inlet, due a greater fetch. SCA conditions are likely on
the ocean waters.

.HYDROLOGY...
No hydrologic impacts are expected into next week.

.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from noon today to 6 AM EST Wednesday for
ANZ331-332-335-338-340-345.
Small Craft Advisory until 6 AM EST Wednesday for ANZ350-353-
355.-- End Changed Discussion --

SYNOPSIS...JMC/DW
NEAR TERM...JMC/DW
SHORT TERM...JMC
LONG TERM...DW
AVIATION...DW/MW
MARINE...JMC/DW
HYDROLOGY...JMC/DW