okx-afd on 2025-04-16

755
FXUS61 KOKX 161934 CCA
AFDOKX

Area Forecast Discussion...CORRECTED
National Weather Service New York NY
334 PM EDT Wed Apr 16 2025

.SYNOPSIS...
A series of weak surface troughs move through the area into
Thursday. High pressure then builds overhead Thursday night
and then offshore on Friday. A warm front lifts north of the
area late Friday into Friday night. A cold front moves through
Saturday night into Sunday morning followed by brief high
pressure. Then, a frontal system impacts the region late Monday
through late Tuesday. High pressure then follows into Wednesday.

.NEAR TERM /THROUGH THURSDAY/...
-- Changed Discussion --An upper trough will continue pushing offshore tonight. Closed
low over southeast Canada will also continue to spin as it
slowly lifts towards the Maritimes into Thursday. This pattern
will keep the region between building high pressure to the west
and the aforementioned low pressure to our northeast. The low
begins to weaken as it moves over the Maritimes late Thursday
allowing the high pressure to begin settling over the area.

Breezy WNW winds will continue tonight although the 25-35 mph
gusts occurring for much of the day will weaken this evening.
Gusts 20-25 mph are possible the first half of the night, but
should weaken further early Thursday morning. The boundary does
not decouple with the gradient in place so sustained winds will
likely remain up and be around 10 mph for most spots. Moisture
trapped beneath a subsidence inversion around 4-5 kft diminishes
overnight. The broken stratocu associated with the subsidence
inversion should scatter out leading to mostly clear skies
overnight. Lows will fall into the middle 30s inland and upper
30s and low 40s closer to the coast. Frost is not expected where
the growing season has begun due to the winds remaining up and
temperatures struggling to fall into the mid 30s.

WNW-NW flow will continue on Thursday, but the air mass begins
to moderate. Mixing does not appear as deep, but models have
struggled all year with the depth of the mixed layer and
resulting winds. Thursday looks like another day where winds
will likely be a bit stronger than modeled, which will also lead
to slightly warmer temperatures. Have gone closer to the NBM
90th percentile for temperatures, which yields highs in the
lower 60s for most spots. Sustained winds 10-15 mph with gusts
20-25 mph look likely, especially in the late morning and
afternoon. Winds will start subsiding late in the day as the
pressure gradient relaxes due to the high pressure nearing the
region. Mostly clear skies are expected for Thursday.-- End Changed Discussion --

.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
-- Changed Discussion --Ridging will build both aloft and at the surface Thursday night.
Winds should be weak under clear skies and a dry air mass. This
will set the stage for ideal radiational cooling conditions
outside the NYC metro. Lows look to fall into the lower 30s
inland and middle to upper 30s most elsewhere. Temperatures will
likely remain in the 40s in the NYC metro. The LI Pine Barrens
should also bottom out around 30 degrees, where the growing
season has already begun. Some patchy frost has been included
here for now, but confidence in widespread freezing temperatures
is low for any headline at this time.

Ridging will continue to build over the eastern US on Friday.
The surface high will shift offshore through the day setting up
a southerly return flow. A weak shortwave is expected to
traverse around the periphery of the ridge which should send a
warm front towards the area late in the day. The lower levels
should remain dry, but mid and upper level moisture increase in
the afternoon. Model consensus PoPs have largely remained around
20 percent across the interior late in the day, but overall
mainly dry conditions will continue. The southerly flow will
hold temperatures close to seasonable levels across Long Island
and Southern CT. Temperatures across portions of NYC, NE NJ, and
Lower Hudson Valley should rise into the middle and upper 60s.-- End Changed Discussion --

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Key Messages:

* Warm temperatures Friday night into Saturday with highs in
the 70s to low-80s.

* Slight chance of showers ahead of cold front Saturday evening
into early Saturday night.

* Average temperatures and dry weather into Sunday under brief high
pressure.

* Additional showers possible late Monday into late Tuesday with a
frontal system, but uncertainty remains.

An upper-level ridge will be in place Friday night into
Saturday with a warm front moving north of the area. This keeps
us warm- sectored Friday night into Saturday with strong warm
air advection. Lows will much warmer Friday night, as a result,
in the mid-50s to upper-40s. Well above average highs are
expected on Saturday in the low-80s to 70s. Mainly dry weather
on Friday night, but that may change by late Saturday into
Saturday night.

Low pressure that brought a warm front through the area will
eventually track into eastern Quebec bringing a cold front
through the area Saturday night into Sunday morning. This will
bring a quick chance of showers and bring down temperatures on
Sunday. Previously, there was quite a bit of disagreement on the
cold front timing, with some guidance bringing it in Saturday
night and other guidance bringing the cold front in on Sunday
night or even Monday night. Now the 12Z GFS/GDPS/ECMWF are in
agreement on the front pushing through by or during Sunday
morning. It appears a longwave trough moving in through southern
Canada will help push this front all the way through and to the
south of our area. It looks like the 13Z deterministic NBM was
still in favor of the later timing of the front, so blended in
some NBM 50th for highs to steer away from this bias.

This brings Sunday`s highs down into the 60s. Its important to
note that there is still a chance, although smaller now, that
the front could come in later than Sunday morning. Should this
occur, such as what the 12Z ICON thinks, would lead to warmer
temperatures on Sunday that currently forecast.

PWATs climb to 1.4-1.5" ahead of the cold front Saturday evening
and early night with increased dewpoints. Isolated to scattered
light showers are possible during this timeframe before
moisture drops fast in response to the approaching and passing
cold front.

Monday through Wednesday is filled with much uncertainty. All
available 12Z guidance diverges and brings different solutions.
In general, late Monday through late Tuesday a frontal system
is expected to impact us and bring a chance for showers. Timing,
placement, and magnitude still vary. Some guidance bring a low
over the area, others have a low pass northwest with another low
developing at the coast along a front. Went with a general NBM
blend for this time frame. High pressure will likely settle in
following the frontal system, which would be timed for
Wednesday.

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
High pressure builds in from the west through Thursday, and settles
just to the south Thursday night.

VFR through the TAF period.

WNW/W winds continue through the forecast period. Gusts generally 25
to 30 kt over the next couple of hours. By early this evening the
winds may become a bit more NW and begin to diminish some. The metro
terminals are expected to hold onto to gusts through the night, but
closer to 15 to 20 kt. However, these may end up being more
occasional at times rather than prevailing. Outlying terminals are
expected to lose gusts altogether for at least a portion of the
night, more likely after 05z.

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

No unscheduled amendments expected.

.OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...

Thursday afternoon: VFR. WNW winds G20-25kt.

Friday: Mainly VFR. Chance of showers late afternoon and night,
mainly for the NW interior. S winds G15-20kt.

Saturday: Mainly VFR. Chance of showers, mainly NW interior. SW
winds G20-25kt.

Sunday: VFR. NW wind gusts 15-20 kt possible.

Monday: Sub VFR possible in showers.

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

.MARINE...
Gusty WNW winds will continue on the waters tonight, but
should begin subsiding below 25 kt on the non ocean waters. SCA
gusts may continue on the ocean until late tonight. Ocean seas
will also gradually subside below 5 ft by day break Thursday. No
changes were made to the ongoing SCA headlines. Winds may still
gust 15-20 kt on Thursday, but will remain below SCA levels.
Weak flow Thursday night into early Friday will continue to lead
to conditions below SCA levels. Winds and seas begin building
late Friday with potential of SCA conditions Friday evening.
These conditions will continue through Saturday evening.

Thereafter, winds will be below SCA levels on all waters. Waves
on ocean waters climb to 6-8 feet Friday night and remain there
through Saturday. Saturday night, ocean waters may have 5 ft
waves linger through Sunday afternoon before dropping below 5
ft. Thereafter, waves will be below SCA levels on all waters.

.FIRE WEATHER...
An SPS will be issued this evening for Thursday for the Lower
Hudson Valley, New York City Metro, and Long Island due to
an elevated threat of wildfire spread. This is collaborated
with neighboring WFOs and NY State land manager due to drying
fuels, gusty WNW-NW winds 20-25 mph, and RH values falling to
25-30 percent.

.HYDROLOGY...
There are no hydrologic concerns through the middle of next
week.

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 2 AM EDT Thursday for ANZ331-332-
335-338-340-345.
Small Craft Advisory until 6 AM EDT Thursday for ANZ350-353-
355.

SYNOPSIS...BR/DS
NEAR TERM...DS
SHORT TERM...DS
LONG TERM...BR
AVIATION...JE
MARINE...BR/DS
FIRE WEATHER...
HYDROLOGY...BR/DS