discussion on 2024-03-18

000
FXUS61 KOKX 181442
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1042 AM EDT Mon Mar 18 2024

.SYNOPSIS...
Deepening low pressure will track slowly east across eastern Canada
to start the week. A series of weak cold fronts and/or troughs will
swing through the area through tonight. Low pressure brings
another cold front through the area on Wednesday. High pressure
briefly returns Thursday into Thursday night. The high gives
way to another potential low pressure system for the upcoming
weekend.

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --Forecast remains on track with only minor adjustments to the
hourly temperatures dewpoints, and cloud cover to reflect the
most recent observations and trends.

Deepening low pressure over extreme Southeastern Canada and the
Canadian Maritimes will continue to slowly push northeast with
the local area remaining in its northwest flow. A series of weak
cold fronts associated with the low pressure push through today
allowing for reinforced colder air to advect into the area.
Skies will remain partly cloudy during much of the day with
highs in the upper 40s and low 50s.

The weak cold fronts push through by evening, also allowing for an
increase in wind gusts as the pressure gradient tightens over the
area. Gusts tonight could approach 20-25 mph with low dropping into
the low to middle 30s for most and upper 20s for interior areas.-- End Changed Discussion --

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
By Tuesday, high pressure attempts to build into the area from the
southwest allowing for the pressure gradient to remain fairly tight
over the area. Skies will remain fairly clear with a WNW wind 15-20
mph with gusts up to 30 mph. The associated CAA from the wind will
prevent temperatures from rising above the middle to possibly upper
40s.

Another piece of energy embedded in the mid-level trough overhead
approaches from the northwest. This causes a surface low to develop
and swing through the area on Wednesday. A chance of showers will be
possible with the low pressure and cold frontal passage during the
day, especially for areas to the north.

Behind this low pressure, high pressure looks to quickly move in
from the west so winds will likely increase substantially Wednesday
night and into early Thursday with gusts 30-35 mph possible.

.LONG TERM /THURSDAY THROUGH SUNDAY/...
No major changes were made to the forecast Thursday into the
upcoming weekend.

A large upper trough and closed low near New England to start
Thursday will give way to a somewhat zonal flow or weak ridge by
Friday. Another breezy day is expected Thursday as high pressure
builds into the area. Highs should be below normal in the lower to
middle 40s. The high settles over the area Thursday night leading to
a cold night with lows in the 20s for much of the area.

The forecast become highly uncertain for late Friday into the
weekend. There is a large amount of spread among both the
deterministic runs and their associated ensembles heading into the
weekend. The large scale pattern appears to be decent agreement with
another closed low spinning over southern Canada and a southern
stream wave traversing across the southeast on Friday. Difference
are quite large with the amplitude of the southern stream wave and
whether our not there will be any interaction with the northern
stream troughing associated with the aforementioned upper low. There
should be a low pressure developing near or along the southeast
coast Friday into Friday night. The GFS is the most aggressive model
taking this low NNE just off the coast into Saturday. The GFS also
has some interaction with the northern stream trough. There are some
ensemble members that agree with this scenario, but the large
majority of the guidance has the northern stream suppressing the
southern stream, which would keep the low much further south into
Sunday. In this scenario, there may just be a brief window for
precip with a cold front before high pressure attempts to build back
in from the north. Have remained persistent with the previous
forecast of chance PoPs (30-40 percent) Friday night into Saturday,
which are consistent with the NBM. Any rain Friday night into early
Saturday could mix with some wet snow for the interior. Otherwise,
plain rain would be the PTYPE elsewhere if precip were to develop.

Temperatures should continue slightly below normal Friday into the
weekend.

.AVIATION /15Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --VFR through the TAF period.

WNW-NW winds becoming 10-15 kt with gusts 20-25 kt into the
afternoon. Gusts should end this evening around 00-02z, with a
WNW-NW flow continuing overnight around 10 kt or less. Gusts
around 20 kt will return Tuesday morning after day break.

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

Gusts may only be ocnl thru 17Z, especially KTEB.

Gusts could linger an hour or two longer this evening.

OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY...

Tuesday: VFR. WNW gusts G20-25kt.

Wednesday: Mainly VFR. Slight chance of rain inland, possibly mixed
with snow. W winds 10-20 kt with gusts 25-30 kt.

Thursday: VFR. WNW winds 15-20 kt with gusts near 25-30 kt.

Friday: Mainly VFR. Chance of MVFR and rain at night with a
rain/snow mix inland.

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

.MARINE...
Marginal gusts to near 25 kt are possible today but should remain
isolated enough to not warrant a SCA on the waters. Winds then
increase tonight to more frequent gusts to 25kt on the ocean so a
SCA is in effect beginning this evening for the ocean. Gusts to 25-
30kt persist on Tuesday for the ocean with wave heights near 5 feet.
The non-ocean waters may occasionally gust to 25kt.

There may be a brief lull in SCA conditions on the waters Tuesday
night before wind gusts on Wednesday promote SCA conditions again on
the ocean, eventually expanding to the non-ocean waters by Wednesday
afternoon. By Wednesday evening, winds should be 25-30kt across all
waters.

SCA conditions will persist on the waters Thursday. There is
also a chance for a few gusts to gale force on the offshore
ocean waters east of Moriches Inlet. It appears marginal at this
time so will hold off on mentioning in the HWO. Winds will then
fall below SCA levels Thursday night and will remain there on
Friday. Ocean seas should subside below 5 ft Thursday night.

.FIRE WEATHER...
Drier conditions are expected today with the minimum relative
humidity 30 to 40 percent, with a west wind 10 to 15 mph, and gusts
20 to 25 mph. An SPS has been issued for the state of CT for
elevated fire weather concerns. This was coordinated with state
partners.

Tuesday and Thursday minimum relative humidity will again range from
25 to 30 percent, with Wednesday`s 35 to 45 percent. Gusty westerly
winds are expected during the day Tuesday through Thursday. The
highest winds and gusts are expected Thursday with winds 15 to 20
mph and gusts 25 to 30 mph.

.HYDROLOGY...
No hydrologic impacts are expected through the forecast period.

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 6 PM this evening to 6 PM EDT
Tuesday for ANZ350-353-355.

SYNOPSIS...DS/MW
NEAR TERM...JC/MW
SHORT TERM...MW
LONG TERM...DS
AVIATION...JMC/DS
MARINE...DS/MW
FIRE WEATHER...
HYDROLOGY...DS/MW