discussion on 2024-02-21

000
FXUS61 KOKX 211513
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1013 AM EST Wed Feb 21 2024

.SYNOPSIS...
-- Changed Discussion --High pressure noses in from our northeast today and weakens
tomorrow morning. A frontal system will move across the area
late Thursday night into Friday, followed by high pressure
building in for the start of the weekend. High pressure then
remains in control through the weekend. A warm front passes
through Sunday night, followed by a weak cold front Monday
morning. Another warm front then approaches from the south
during Tuesday.-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --Only adjustments / tweaks were made to clouds and temps / dew
points for this update. Adjusted cloud cover to better align
with near term guidance and satellite observations. Used a MAV /
MET blend for daytime maxes with only a degree or two variation
from previous fx with respect to afternoon max temps.

High pressure situated over the Canadian Maritimes continues to
attempt nose in from northeast to southwest ,and shall remain
in control for this afternoon. Simultaneously, a low pressure
system will pass to our southeast and east far offshore. This is
not enough to bring any impacts to land other than influence
more onshore easterly flow between 5-10 mph, more pronounced for
eastern and southern areas. Visible satellite continues to show
a strat-cumulus layer around 030 kft. This is supported by
latest ceiling obs and OKX sounding from earlier this morning
showing high RH in the vicinity of this layer. The low and
associated onshore flow keeps some cloud cover in place for
southern and eastern parts of the area the afternoon and
evening. High temperatures will be near seasonable, just a touch
below perhaps with upper 30s to lower 40s for daytime maxes.

Look for partly cloudy skies tonight as high pressure slowly
loses hold in the region. The cloud cover will reduce the chance
for significant radiational cooling tonight. Lows will be in
the 20s for most with the NYC metro area in the lower 30s.-- End Changed Discussion --

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
-- Changed Discussion --As the low well offshore tracks northward to our east, it
pushes the high pressure system out of the Canadian Maritimes
and out into the open North Atlantic. As high pressure loses
control in the region another low pressure system complemented
with a mid-level shortwave approaches from the west.

For the start of Thursday, this low-pressure system is situated
over the Central Plains, tracking east into the Ohio River
Valley. As it approaches, clouds will increase Thursday
afternoon and evening west to east with southerly flow
increasing ahead of the system`s arrival. The increased
southerly flow will allow slightly warmer surface temperatures
on Thursday with highs in the low-40s area-wide.

The southern branch of the jet stream has a zonal structure on
Thursday to our south and west, but dips south in the form of an
upper-level trough on Friday. This puts the mid-Atlantic and
northeast to be in the left exit region of the jet. In response,
the low pressure system will follow this pattern and track
somewhat over the region or directly to the south, most 00Z
models have the center of the system relatively close to the
area on Friday then tracking east and north east of the area on
Friday night into Saturday morning as it exits.

Precipitation will likely start late Thursday night and clear
out Friday night. At the onset, some light snow or rain/snow may
occur in the interior areas. Given onshore flow with warming
temperatures, it won`t last long with very little if any
accumulation. This is looking like mainly a rain even. Event
totals are forecasted to be around a quarter inch over the
course of 36 hours.

Temperatures will be in the 30s as the event starts, but will
warm into the mid/upper-40s mid-event on Friday afternoon. A
cold front will move in as the system exits Friday night
bringing in drier and colder air with lows Friday night in the
low/mid-20s for most. Breezy, northwest winds will follow the
front Friday night and to start the day on Saturday.-- End Changed Discussion --

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
-- Changed Discussion --High pressure will slowly build in on Saturday as the flow
aloft will be cyclonic. The surface pressure gradient will still
be somewhat tight, so gusty NW winds will make temperatures in
the mid to upper 30s in the afternoon feel about 10 degrees
colder. Winds then subside Saturday night into Sunday morning as
the surface ridge shifts into the region. A return SW flow then
develops for the afternoon, and this will help push high
temperatures back to near normal at 40-45.

A warm front approaches Sunday night. Moisture and lift with
the front may be just enough for some light precipitation, which
would be mainly rain with the exception of a wintry mix at
least at the onset across the northernmost zones. A cold front
then follows Monday morning, ending the threat of precip. Kept
PoPs at slight chance for Sunday night into Monday morning. Dry
otherwise for Monday with highs 50-55. Weak high pressure gives
way to an approaching warm front from the SW on Tuesday. Rain
chances begin in the morning, but become more likely in the
afternoon and night.-- End Changed Discussion --

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --High pressure remains in place.

VFR, but a chance of MVFR as cigs average 3000-3500 ft. These
between 025 and 035cigs may be stubborn to scatter until late
aft/eve, with potential re- development tonight.

Winds will be light easterly, veering to ESE in the aftn. Winds
becoming light E/NE or variable this eve.

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

Cigs potentially prevail or temporarily fall to 2500-3000 ft
today. If cigs lower to MVFR, timing/occurrence of a return to
VFR this afternoon may be off by a couple of hours. Tempo MVFR
may not occur this evening, but there`s also a chance that MVFR
prevails this evening.

The afternoon haze potential forecast is YELLOW...which implies
slant range visibility 4-6SM outside of cloud.

OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY...

Thursday: VFR. Chance of MVFR in the morning.

Thursday night and Friday: MVFR/IFR conds likely develop in rain,
possibly beginning as a wintry mix at the onset at KSWF.

Friday night: VFR. NW winds G15-20kt.

Saturday: VFR. NW winds G20-25kt.

Sunday: VFR

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

&&

.MARINE...
Although high pressure is leading to quiet conditions over the
waters, a long period southeasterly swell will move in Wednesday
night from strong offshore low pressure. A Small Craft Advisory is
now in effect for Wednesday night for the ocean waters. This
advisory will likely be extended as the swell sticks around for
several days. Wave heights on the ocean waters will reach 5 to 8
feet by Thursday.

SCA conditions continue on the ocean waters through Saturday,
primarily due to swell, but gusts over 25kt are expected into
Saturday behind the passage of low pressure and a cold front. This
will bring advisory conditions to the non-ocean waters as well. Sub-
SCA conditions likely return during Saturday night and last into
most of Sunday as high pressure moves across the area with subsiding
winds and seas.

&&

.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 from 10 PM this evening to 7 PM EST
     Thursday for ANZ350-353-355.

&&

$$

SYNOPSIS...JC/BR
NEAR TERM...JE/BR
SHORT TERM...BR
LONG TERM...JC
AVIATION...JC/MET
MARINE...JC/JE/BR
HYDROLOGY...JC/BR