738
FXUS61 KOKX 252001
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
401 PM EDT Tue Mar 25 2025
.SYNOPSIS...
A surface trough passes over the area tonight between low
pressures to our north and south. Another surface trough is
expected tomorrow afternoon/evening in response to a low exiting
to the northeast. High pressure builds in from the southwest
tomorrow night. High pressure slides offshore Thursday night as
a frontal boundary slowly approaches and stalls nearby into the
weekend. A series of disturbances will develop along a complex
frontal boundary to the west as a warm front lifts north of the
area Sunday night into Monday. The trailing cold front sweeps
through Monday night followed by high pressure building on
Tuesday.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
A weak surface low passes to our north in southern Quebec this
evening into tonight. At the same time, a surface low develops along
the mid-Atlantic coast this evening and tracks to our south over the
Atlantic Ocean tonight as it strengthens. This southern low develops
as an upper level trough amplifies over the Great Lakes and moves
towards the northeast as a closed upper-low develops and moves into
the Niagara Peninsula area tonight.
A surface trough passes tonight between the low to our north and to
our south. The strengthening low to our south will also pass close
enough to lead to slightly increased moisture across eastern zones
with PWATs to the east around 0.4-0.5". Given slightly higher
moisture, PVA aloft around the base of the amplifying trough, lift
from the surface trough, and the nearby pass of the low to the
south, we could see light rain overspread eastern Long Island and SE
CT tonight. Precip should be light enough that only trace amounts of
rain are expected.
W/SW winds this evening should continue to weaken into early tonight
before turning north in response to the surface trough passing and
low pressure moving more east to our south late tonight.
Low temps tonight will partially hinge on cloud cover which will be
higher southeast and lower southwest. Lows will be in the upper-30s
to lower-40s tonight from NYC metro and Long Island to S CT.
Interior S CT and the Lower Hudson Valley should cool to the low-30s
to upper-20s given lower cloud cover.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Tomorrow, an amplified upper-level trough will center itself over
the area with a closed upper-low very close to the CWA to our north.
A surface low will exit northeast tomorrow afternoon, dragging
another surface trough through the area.
Expecting scattered cloud cover with spotty shower coverage along
the surface trough in the interior that becomes more isolated
towards the southern coastlines. Showers should be aided by PVA from
the nearby upper-low Wednesday afternoon to evening. Not expecting
much if any accumulation with these showers, as they will be light.
However, temperatures will be colder on Wednesday which could lead
to some snow mixing in in the interior.
Strong WNW flow is expected tomorrow afternoon/evening under a
stronger pressure gradient from a low exiting northeast. Pretty
notable cold air advection aloft at 850mb and 700mb with the trough
bringing 500mb heights down over the area 530-538 mb, which returns
a height anomaly of around -20 dam. This should keep highs on
Wednesday around the low-50s to upper-40s. Near-seasonal to slightly
below seasonal values.
Cold air advection continues Wednesday night under clear skies as
high pressure moves in the the region from the southwest in response
to an exiting upper-level trough. With clear skies, light NW flow,
and cold air advection, should see better radiational cooling. Lows
Wednesday night will be in the mid-30s to mid-20s.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
High pressure settles nearby Thursday providing seasonably cool
conditions are temperatures are expected to run a bit below normal
for late March, despite a good amount of sunshine and a westerly
flow. There is some uncertainty around how high temperatures will
ultimately get during the late morning and afternoon on a westerly
wind. The air mass is cP in nature, but often this time of year with
the higher sun angle and downsloping winds temperatures can
overachieve. Thus would not be surprised if temperatures can get as
much as 5 degrees or so warmer than currently forecast. A frontal
boundary and a weak disturbance will then draw closer Thursday night
and ultimately pass through by Friday morning. There may be enough
mid level moisture down to around 5 kft that a few light showers or
a few sprinkles could work in during Thursday night, thus have some
coverage of slight chance PoPs. Otherwise, the expectation is that
is stays mainly dry Thursday night and through the day Friday.
The boundary will ultimately stall either over the region or just
south of the area Friday night and into the start of the weekend.
This will lead to another shower / sprinkle chance Friday night into
early Saturday morning, and thus carry chance to slight chance PoPs
through the timeframe and into the day Saturday. A southern branch
feature / shortwave then approaches for Saturday night into Sunday
morning. The ECMWF has been slower with the approach of this feature
compared to the GFS guidance. This should reintroduce the relatively
higher chance of shower activity for Saturday into a portion of
Sunday. The question for Sunday then becomes as the low pressure
attempts to develop off to the west, will this help get the warm
front north of the area late in the weekend. Based on the time of
year, this may get delayed or may not even occur. Another shortwave
originating out of the Pacific branch of the jet stream then
approaches and should develop or redevelop low pressure further east
towards Monday. Depending on how far east things progress will
ultimately determine how unsettled it will be to begin next week.
For now have likely PoPs for a portion of Sunday night, and carry
chance PoPs for much of the area into MondaY.
The entire complex frontal system and any subsequent waves of low
pressure should progress off the coast into Monday night, with a
drier NNW flow regime as Canadian high pressure builds in for
Tuesday. Overall forecast confidence is below average through the
entire long term period with multiple questions around low level
boundary positioning, and mid level shortwave timing
inconsistencies.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
Weak low pressure passes well to our southeast late tonight.
Weak high pressure builds in Wednesday.
VFR is expected through the end of the TAF period.
W to SW flow today with gusts to around 25 kt, with local sea
breezes moving through KJFK late (after 22Z) and possibly KGON. Sea
breezes have already moved through KISP, and KBDR. Occasional gusts
up to 30 kt are possible for the remainder of the afternoon. Gusts
diminish after 22Z-23Z, with sustained winds becoming light from the
NW tonight. W winds expected Wednesday morning, starting off at 5 to
10 kt, but increasing to 10 to 15 kt by late morning into the
afternoon.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Occasional gusts around 30 kt are possible this afternoon.
.OUTLOOK FOR 00Z WEDNESDAY THROUGH SUNDAY...
Wednesday: VFR. Afternoon W/NW wind gusts up to around 20 kt.
Thursday: VFR.
Friday: VFR. W wind gusts 15-20 kt.
Saturday: VFR during the day, MVFR possible at night. E to SE wind
gusts 15 to 20 kt.
Sunday: MVFR or lower possible in light rain. E to SE
wind gusts 15 to 20 kt.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
There is one remaining SCA on the eastern ocean. SSE swell above 5
ft will remain on the eastern ocean until later tonight, then the
SCA will expire. Winds and seas then remain below SCA criteria Wed
and Wed night.
No advisories are anticipated across the coastal waters later this
week. Sub advisory conditions are anticipated to last through much
of the weekend with peak winds out on the ocean approaching 20 kt at
times Saturday through Sunday. Small craft conditions may return on
the ocean towards Sunday night.
&&
.FIRE WEATHER...
WNW winds will be similar in strength to that observed on Tuesday or
slightly weaker while relative humidities will be slightly higher
than observed on Tuesday. This should translate to reduced fire
weather concerns on Wednesday, but there is still some small concern
for increased brush fire risk given fuels have already had a day to
dry out from the higher winds observed on Tuesday. This will also be
the case if RH drops lower than forecasts or winds become stronger
than forecast.
&&
.HYDROLOGY...
No hydrologic impacts are expected through the upcoming weekend.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 11 PM EDT this evening for ANZ350.
Small Craft Advisory until 4 PM EDT this afternoon for ANZ353-
355.
&&
$$
SYNOPSIS...JE/BR
NEAR TERM...BR
SHORT TERM...BR
LONG TERM...JE
AVIATION...JP
MARINE...JE/BR
FIRE WEATHER...
HYDROLOGY...JE/BR
NWS OKX Office Area Forecast Discussion
