okx-afd on 2025-01-28

209
FXUS61 KOKX 282111
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
411 PM EST Tue Jan 28 2025

.SYNOPSIS...
-- Changed Discussion --A fast moving low will track east across the Great Lakes tonight
and then pass to the north on Wednesday, dragging a cold front
through the area in the afternoon. High pressure briefly builds
in on Thursday followed by low pressure and its associated
frontal system Friday into Friday night. High pressure should
largely remain in control this weekend into early next week, but
there is a chance for a quick moving frontal system Sunday.-- End Changed Discussion --

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
-- Changed Discussion --Another fast moving clipper low will track east across the Great
Lakes tonight and into upstate NY by daybreak. This will allow
the cold front that past to the south earlier today to return
quickly north as a warm front this evening and then well to the
north later tonight. Guidance has trended north with the
overrunning snow ahead of the warm front with only a slight
chance this evening across far northern portions of the Lower
Hudson Valley and interior southern CT. Anything that does fall
will be light with possibly a light coating across some
locations.

With weak surface ridging moving in early this evening ahead of
the low and warm front, winds will fall off quickly and
temperatures will drop off into the 20s for all but the NYC
metro. However, a strengthening southerly behind the warm front
will allow temperatures to begin to rise around midnight with
most locations above freezing by daybreak except for the far
interior.-- End Changed Discussion --

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
-- Changed Discussion --Low pressure passes to the north on Wednesday sending a cold
front through the area in the afternoon. Temperatures get into
the lower to mid 40s late morning into early afternoon. This
will be very similar to what we saw on Tuesday with scattered
showers along and ahead of the cold front and increasing west
winds with gusts 35 to 45 mph. Model upper air soundings shows
deep mixing during the day with 30 to 40 kt average winds in the
mixed layer and 50-60 kt at the top of the layer (near 700 mb).
However, have held back on a wind advisory as it seems unlikely
to bring the strongest winds all the way down, but like Tuesday
a few isolated gusts to 40 kt (46 mph) will be possible. This
will be reevaluated later tonight with the 00Z model guidance.

In addition, with the warmer mixed layer much of the showers
will be in the form rain, with possibly rain/snow mix across the
higher elevations north and west of NYC. Snow squalls seem
unlikely due to the mix and would not be as much of a factor
with warm surface temperatures. Temperatures behind the front
may drop off by as much as 5 degrees, but not expecting
temperatures at or below freezing until the evening.

Gusty NW winds diminish some Wednesday evening, but likely stay
up much of the night. Lows by daybreak Thursday will range from
the upper teens inland to the lower 20s at the coast. This is a
few degrees below normal. Wind chill values will fall into the
upper single digits to lower teens after midnight.-- End Changed Discussion --

.LONG TERM /THURSDAY THROUGH TUESDAY/...
-- Changed Discussion --The synoptic pattern to start the long term consists of an
upper level low moving out of the SW US on Thursday and
weakening into an open wave by the time it reaches the Ohio
Valley on Friday. The weakening wave will pass overhead late
Friday into Friday night and then offshore Saturday. The flow
aloft will then remain zonal this weekend into early next week.
There is potential of a weak shortwave passage within the zonal
flow sometime late Sunday into early Monday.

A surface ridge moves over the region Thursday and then offshore
Thursday night. The models over the last several days were having a
difficult time with the confluent flow across New England and the
northward extent of the weakening shortwave. The last few model
cycles have come into better agreement on the confluence weakening
Thursday night allowing the parent low pressure to track either to
our northwest or nearly over the area Friday into Friday night. The
modeled pattern only supports a wintry mix of freezing rain and
sleet at the onset late Thursday night into early Friday morning.
The highest probability for this brief wintry mix lies north and
west of the NYC metro, where surface temperatures may take longest
to rise above freezing. Elsewhere, increasing warm advection and SW
flow will support temperatures warm enough for plain rain. Any
wintry mix across the interior will transition to a cold rain by mid
morning on Friday. The exact track of the low will ultimately
determine how warm temperatures reach on Friday, but the latest NBM
deterministic has temperatures rising into the 40s in the afternoon
areawide. Precip should quickly taper off Friday evening with
limited chances for a few snow showers as the low moves offshore.
Total liquid equivalent amounts range from one around a quarter inch
inland to one half to three quarters closer to the coast.

High pressure returns Saturday and pushes offshore on Sunday.
The next frontal system moves through late Sunday into Sunday night.
Models differ on the amplitude of the associated shortwave with the
GFS the most amplified and the ECMWF the weakest. Capped PoPs off at
chance given the differences, which is lower than the NBM across
interior CT. High pressure then returns early next week.

Near normal temperatures Thursday will become above normal on
Friday. Below normal temperatures return Saturday behind the first
frontal system before becoming above normal again Sunday and Monday.-- End Changed Discussion --

.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
-- Changed Discussion --VFR as a cold front to the south returns north as a warm front
tonight, as low pressure moves out of the upper Great Lakes and into
upstate NY and New England daytime Wed.

NW winds at 21Z were in process of diminishing to 10-15kt with gusts
either side of 20 kt. These winds should quickly fall to under 10 kt
by about 23Z.

Winds tonight then become light/vrb as the front returns north,
then S 5-10 kt overnight and SW 10-15G20-25kt after about 14Z.
Speeds/gusts may be higher than that at the metros and along the
coast.

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

No unscheduled AMD expected.

.OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY...

Wednesday afternoon: WSW winds G30-35kt. Chance of rain/snow
showers with brief IFR cond at KSWF, MVFR cond elsewhere.

Wednesday night: Cold fropa with VFR and winds shifting NW
G25-30kt, diminishing to G20-25kt after midnight.

Thursday: VFR. NW winds G20kt in the morning.

Friday: Rain likely with MVFR or lower cond, changing to light
snow after midnight before ending. SW winds G20kt NYC
metro/coast.

Saturday: Becoming VFR in the morning. NW winds G20kt until
around midday.

Sunday: Chance MVFR or lower cond mainly at night, with snow
changing to freezing rain/sleet at KSWF, and rain/snow/sleet
NYC metros/coast.

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

.MARINE...
-- Changed Discussion --Gale warning in effect for all water Wednesday.

There will be short period of sub-SCA conditions this evening,
but this will be short-lived as an approaching frontal system
will result in a W/SW gale developing toward daybreak Wednesday
and then becoming NW and persisting into the first half of
Wednesday night on the ocean waters. For the non-ocean waters
gales will be a bit shorter ending toward evening.

Conditions will remain below SCA levels on the waters Thursday into
Thursday night. Low pressure and its associated frontal system
impact the waters Friday into Friday night with the next chance of
SCA conditions. SCA winds and seas may linger on the ocean Saturday
morning followed by conditions below SCA Saturday night into Sunday.-- End Changed Discussion --

.HYDROLOGY...
-- Changed Discussion --
There are no hydrologic concerns through early next week.-- End Changed Discussion --

.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 PM EST this evening for ANZ331-
332-335-338-340-345.
Gale Warning from 6 AM to 6 PM EST Wednesday for ANZ331-332-
335-338-340-345.
Small Craft Advisory until 6 AM EST Wednesday for ANZ350-353-
355.
Gale Warning from 6 AM Wednesday to 1 AM EST Thursday for
ANZ350-353-355.-- End Changed Discussion --

SYNOPSIS...DS/DW
NEAR TERM...DW
SHORT TERM...DW
LONG TERM...DS
AVIATION...BG
MARINE...DS/DW
HYDROLOGY...DS/DW