discussion on 2024-02-21

000
FXUS61 KOKX 211136
AFDOKX

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

.SYNOPSIS...
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.

&&

.NEAR TERM /THROUGH TONIGHT/...
Only minor changed were made to temperatures and dewpoints in
this update to account for current observations and trends.
Otherwise, the forecast remains on track.

The morning starts off with surface high pressure in control,
keeping us dry for the day. Situated over the Canadian Maritimes, it
is nosing in from northeast to southwest and shall remain in control
for the day today. 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.
The low and associated onshore flow may increase cloud cover for
southern and eastern parts of the area this afternoon and evening.
High temperatures will be near seasonable in the upper-30s to lower-
40s.

Sky cover will remain partly cloudy 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 low-30s.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
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.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
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.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --High pressure remains in place.

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

Light NE winds, increasing and bcmg more east by 13-14z. Winds
continue 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...BR
SHORT TERM...BR
LONG TERM...JC
AVIATION...JC
MARINE...JC/BR
HYDROLOGY...JC/BR