114
FXUS61 KOKX 121149
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
749 AM EDT Sun May 12 2024

.SYNOPSIS...
A frontal system approaches this morning and passes south and east
of the area later today. High pressure returns Sunday night. A warm
front passes north of the area Monday. High pressure moves
offshore Tuesday with low pressure approaching from the west. An
area of low pressure passes south of the area Wednesday and
then southeast of the area Wednesday night into Thursday. Weak
high pressure then follows going into Friday before another low
approaches for the start of next weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
The forecast remains on track. No changes were made with this
update. The arrival of a line of rain remains on time and
should pick up in areas west and south of the NYC metro soon.

A weak frontal system is approaching the area this morning with a
midlevel shortwave and passing through late morning into early
afternoon. Light showers have already developed along an occluded
front in western portions of the CWA and will weaken before
dissipating as they track east. Areas around the NYC metro and west
and south of the NYC metro could see totals around or just below
0.25" with amounts quickly tapering east and north of the NYC metro.
Even though lift along the occluded front will be weak, we will
still see increased moisture and positive vorticity advection
associated with the midlevel shortwave. The east end and east CT may
see no rain at all today.

The atmosphere will be mostly stable, so no thunderstorms are
expected, however, a few isolated showers are possible in S CT and
LI this afternoon, based on the latest CAMs. High pressure tries to
build in the wake of the weakened exiting low this afternoon, so
subsidence will really be working against the development of these
afternoon showers, but may be aided by lingering midlevel moisture
and energy associated with the exiting shortwave.

A fairly deep shortwave trough passing over today will limit highs
to the mid-50s, which is about 10-15 degrees below seasonal
averages.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
Heights will rise Sunday night as the upper trough continues
departing to the east. Surface high pressure will be in place
leading to mostly dry conditions. Clouds should slowly diminish
through the night with mostly clear to partly cloudy skies by early
Monday morning. Another chilly night is expected with lows in the
40s.

A ridge will continue to build on Monday leading to noticeably
warmer weather compared to Sunday with highs in the low/mid-60s
to the east with onshore flow and western inland areas in the
upper-60s to low-70s. A warm front will also be skirting the
area to the north, extending from a low in Canada. This warm
front could lead to a few showers that dissipate as they track
north to south. Confidence in the showers occurring, though, is
low due to the riding aloft and surface high pressure working
against them. PWATs around 1-1.2" will be in place, though.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
From the analysis of some large scale deterministic weather
prediction forecast models, the following features are noted.

In the mid levels, the local area appears to be in between a trough
and a ridge. The trough is over SE Canada and the ridge is southeast
of the area, based in the Atlantic. The ridge moves farther east
Tuesday night into Wednesday with a trough moving in. The center of
the trough moves across either Wednesday night or Thursday. There
are model differences resolving this feature.

For Thursday night through Friday night, the local area is shown to
be in between troughs in the mid levels, with some brief ridging.
Next trough moves in for the start of next weekend.

At the surface, a warm front moves farther north of the area Tuesday
with low pressure developing along a cold front to the west. There
are multiple areas of low pressure developing along this front.
Eventually, there is one main low that is forecast to move south of
Long Island Wednesday and then farther out into the Atlantic
Wednesday night into Thursday. There are model differences in their
depiction of the low and its translational speed.

Chances for rain showers increase Tuesday, with rain showers
expected to be widespread across the area by Tuesday night and
continuing into Wednesday. Chances for rain showers remain for
Wednesday night with a slight chance of rain showers Thursday. Rain
could be moderate to possibly heavy at times Tuesday night into
Wednesday. With colder air aloft and some elevated instability
potentially, there could be a few embedded thunderstorms. Just left
the thunderstorms as slight chance in terms of their probability.

By Thursday night and Friday, high pressure starts to build in from
the north and east, which will maintain mainly dry conditions
through much of Friday night.

The next low provides the next chances for rain starting out next
weekend.

Temperatures in the daytime look to average above normal Tuesday,
below normal Wednesday, close to normal Thursday and Friday, and
below normal again next Saturday.
-- End Changed Discussion --

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
A weakening frontal system moves in today. Weak high pressure
returns later today and lasts through the rest of the TAF period.

Some rain showers are expected with this frontal system with
higher chances for NYC terminals, KHPN and KSWF and lesser
chances for KISP and KBDR as well as KGON. Highest chances for
rain occur before 14Z this morning. Chances for additional rain
showers still present late this morning into this afternoon but
confidence lower on these so difficult to narrow down time and
location of these in TAFs. No mention of showers for KGON as
for that terminal, probabilities for showers are too low.

Conditions will be mainly MVFR this morning and then gradually
improve to VFR this afternoon, especially for the latter half.
VFR then remains tonight into early Monday.

There will likely be some MVFR continuing this afternoon but
overall mainly VFR conditions are expected this afternoon
through tonight.

Wind speeds at or less than 10 kt expected during the TAF
period. Wind direction overall southerly on average becoming
more SW late tonight into early Monday.

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

MVFR timing could vary from TAF by a few hours. Some fluctuation
between VFR and MVFR possible.

OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY...

Monday: VFR.

Tuesday: MVFR or lower possible in mainly afternoon showers. S
winds gusts near 15-20kt coastal terminals.

Tuesday night: MVFR or lower likely in showers. S wind gusts
near 15kt coastal terminals.

Wednesday: MVFR or lower still likely in showers and possible
t-storms. SE wind gusts 15-20kt, becoming NE late day and at
night.

Wednesday night: Chance of showers and MVFR. NE wind gusts
15-20kt.

Thursday: Mainly VFR.

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

&&

.MARINE...
-- Changed Discussion --
Winds are expected to remain below SCA conditions for the entirety
of Sunday. Monday evening/early night may briefly reach 5 feet
before dropping back down to 4 feet.

Long term marine from Tuesday through Thursday night, initially
below SCA conditions expected Tuesday into Tuesday night. Then,
SCA conditions become probable Wednesday into Wednesday night
which could very well linger into Thursday, especially on the
ocean.
-- End Changed Discussion --

&&

.HYDROLOGY...
No hydrologic impacts expected through next week.

&&

.TIDES/COASTAL FLOODING...
No coastal flooding is anticipated as astronomical tide levels
continue subsiding into early next week.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.

&&

$$

SYNOPSIS...JM/BR
NEAR TERM...BR
SHORT TERM...BR
LONG TERM...JM
AVIATION...JM
MARINE...JM/BR
HYDROLOGY...JM/BR
TIDES/COASTAL FLOODING...