discussion on 2023-05-16

000
FXUS61 KOKX 170013
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
813 PM EDT Tue May 16 2023

.SYNOPSIS...
A cold front approaches this evening and passes through the
area during the early morning hours Wednesday. High pressure
then builds in from the northwest through midweek, before
building offshore Thursday afternoon through Friday. A frontal
system impacts the area Saturday. High pressure begins to build
Sunday and remains in play Monday and Tuesday.

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
-- Changed Discussion --The fcst is on track this eve. An amplifying upper trough
across eastern Canada and the Northeast will send a cold front
across the area later tonight with a shot of much cooler air to
follow for the mid week period. Gusty SW winds become NW
following a cold frontal passage after midnight. This will be a
dry frontal passage as this system is moisture starved as a
frontal wave passes to the south off the Mid Atlantic coast.

The cold advection behind the front occurs late enough that lows
will only drop to near normal, ranging from the upper 40s
inland, to the lower and mid 50s along the coast.-- End Changed Discussion --

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Following a cold frontal passage, high pressure over the Great
Lakes will build south and east through Wednesday night. A gusty
NW flow on Wednesday (up to 25 mph) will combine with a very dry
airmass (Min RH around 20 percent) to produce an elevated risk
of fire spread. See Fire Weather section below for additional
details.

Highs Wednesday will be a few degrees below normal with readings
in the 60s.

A much colder night on Wednesday night along with diminishing
N winds will allow temperatures to drop into the lower and
middles 30s inland and across the Pine Barrens Region of LI,
with the 40s elsewhere. There is enough uncertainty with how
quickly the winds fall off and the low RH to hold off on any
frost/freeze headlines at this time. For lows, used a blend of
the colder MET/MAV MOS with the warmer NBM.

.LONG TERM /THURSDAY THROUGH TUESDAY/...
High pressure takes over on Thursday leading to clear skies and
no POPs. Highs remain similar to Wednesday with dewpoints still
on the dry side. Thursday night the high pressure shifts shore,
returning a 5-10 kt southerly flow. This will prevent some
radiational cooling and raise dewpoints. The warm air advection
really takes hold as max temps increase from low/mid-60s on
Thursday to mid-60s/low-70s on Friday. Used mainly NBM for this
as it picked up on the effects of the southerly flow well. High
pressure continues to lose influence into the day on Friday,
with slight lowering of heights. This will be complimented by
increasing clouds on Friday.

This weekend will be largely influenced by a frontal system
that still has some timing discrepancies associated with it. The
12Z GFS has rain starting early in the morning while the 12Z
ECMWF has rain starting by the afternoon. The frontal system
will be influenced by an upper-low helping to force the system
while moisture is also being fed in ahead of the front up from a
disturbance off the Atlantic coast with southerly winds. Went
with NBM POPs which keeps a chance of rain through Saturday and
drops POPs for Sunday. This timing is a little earlier than the
prior forecast and is still subject to adjustments.

Late Sunday into next week a surface high sets up over Quebec
and Nova Scotia with an associated inverted surface ridge, that
extends down the coast into our area. This will lead to pressure
height increases to begin next week allowing for dry weather to
return with seasonal temperatures.

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
VFR.

A cold front approaches and moves through the terminals late this
evening into tonight. High pressure builds in from the northwest
late tonight through Wednesday.

WSW wind diminish with any gusts ending around or soon after
sunset. Winds then shift to the NW with the passage of a cold
front. Toward Wednesday morning winds become more northerly with
gusts developing. There is some uncertainty with the timing of
the wind shifts to NW and N tonight, and may be +/- 1 to 2
hours. NW to N winds increase during Wednesday with peak gusts
25 to 30kt possible in the afternoon. As winds and gusts
diminish late in the day winds shift back to N.

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

No unscheduled amendments expected. Some uncertainty with the
timing of the frontal passage and may be +/- 1 to 2 hours. Peak
gusts 25 to 30 kt possible Wednesday afternoon.

OUTLOOK FOR 00Z THURSDAY THROUGH SUNDAY...

Wednesday night: VFR. N wind 10-15kt, gusts around 20kt, and
ending during the evening.

Thursday and Friday: VFR.

Saturday: Chance of MVFR in showers, mainly late in the day.

Sunday: Chance MVFR in early showers, then VFR.

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

.MARINE...
-- Changed Discussion --Winds will diminish this evening as a cold front approaches
from the NW. SCA hazards will drop from west to east tonight,
with the two easternmost ocean zones dropping last at 4am.
Behind the cold front late tonight, there is the possibility of
short period of gusts up to 25 kt. Thus, have held off issuing a
SCA behind the cold front. High pressure then builds in from
the NW with sub-SCA conditions to follow for the mid week.

Conditions will remain below SCA through Friday night. Waves on
the ocean water build in response to a strengthening S to SE
flow, with 5 ft seas possible by late morning Saturday into the
afternoon. Waves diminish late Saturday night into Sunday
afternoon. Conditions will be below SCA on Monday.-- End Changed Discussion --

.FIRE WEATHER...
-- Changed Discussion --A Red Flag Warning is in effect for CT for Wednesday.

For northeast NJ, NYC, Long Island and the Lower Hudson Valley
an SPS is in effect through Wednesday.

Given antecedent dry conditions along with Min RH values as low
as 20 percent and a gusty flow at 20-25 kt, there is an
elevated potential for fire spread through Wednesday.-- End Changed Discussion --

.HYDROLOGY...
There are no hydrologic concerns through early next week.

.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --CT...Red Flag Warning from 8 AM to 8 PM EDT Wednesday for
CTZ005>012.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 4 AM EDT Wednesday for ANZ350-353.
Small Craft Advisory until 11 PM EDT this evening for ANZ355.-- End Changed Discussion --