238
FXUS61 KOKX 222219
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
619 PM EDT Wed May 22 2024

.SYNOPSIS...
High pressure remains in control the rest of today. A cold front
approaches late tonight and slowly moves through the area on
Thursday, moving offshore sometime early Friday morning. Weak
high pressure builds on Friday. A weak low passes through the area
late Saturday into early Sunday. A deep low pressure system
tracks through the Great Lakes and into Canada late Sunday through
Tuesday with the system`s warm front passing north Monday and its
associated cold front moving through Tuesday into Wednesday.

&&

.NEAR TERM /THROUGH THURSDAY/...
Minor changes were made with this update to POPs and
temperatures. Based on radar, the storms near the Orange county
line have dissipated, so have dropped POPs altogether for the
next few hours. They pick back up only for far western edges of
the CWA in response to a line of storms currently moving through
Central PA. While most of these are expected to break up, its
possible some of them could still reach the western edges of our
CWA before dissipating around 9pm. All POPs after midnight
remain unchanged from the original forecast. Temperatures were
also slightly adjusted this evening and tonight based on current
observations and trends.

A mid-level low, embedded in the broader upper level trough over the
western US, lifts north of the Great Lakes tonight. The associated
surface low will also pass well to our north and west, but will send
a cold front towards our area. Ahead of the front, a S/SW flow has
brought in a hot and humid airmass with 850mb temps around 16 to 18C
and surface dewpoints in the low to mid 60s for most. Moisture will
continue to increase ahead of the front tonight, with guidance
showing pwats peaking around 1.60 inches tonight into early
Thursday. These pwat values are over the 90% moving average for the
12z 05/23 sounding at OKX per the SPC Sounding Climatology Page.

Some showers and thunderstorms have fired up west of the area along
and ahead of a pre frontal trough. Some of this activity could make
it into western portions of the area overnight, mainly north and
west of NYC, but is not expected to be severe with a lack of
shear. The better chances for showers and thunderstorms for our
area will be as the cold front starts to slowly move through
the area Thursday morning. PoPs have trended earlier in the day
with a shift in timing in the 12z CAMs. Given the environment,
with MLCAPE values around 1000-1500 J/kg and 0-6 km shear
increasing to around 35-40 kt, some storms could become strong
to severe. The SPC continues to outline the area in a "marginal"
risk of severe weather, with large hail and damaging winds
being the main threat. Given the high pwats, any thunderstorms
could also produce heavy downpours. At this time, there are no
flooding concerns.

Given the activity in the morning, it will be difficult to
destabilize again for the afternoon and we will likely see just
lingering showers as the front continues to sag through the
area. However, if we end up seeing less or no activity in the
morning, the stronger showers/thunderstorms could be in the
afternoon. For this reason, have left chance of thunder through
the day Thursday.

&&

.SHORT TERM /THURSDAY NIGHT/...
With the front slowly sagging south, a chance of showers and
thunderstorms continue through Thursday night, mainly for the
southern half of the area. The front likely finally passes south
early Friday morning. With plenty of clouds around, above normal low
temperatures are expected. If the front moves through northern
locations a bit quicker and they get under some clearing, some of
these locations could drop lower than the upper 50s.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A cold front exits Friday morning with any lingering precip quickly
exiting with the front. The cold front will not help cool things
down much, with afternoon temperatures still expected to reach the
mid-80s to mid-70s. The front will, however, help dry us out,
reducing any chances for showers or thunderstorms. Sunny to mostly
sunny conditions are expected on Friday.

Zonal flow will remain aloft through the weekend with above normal
temperatures and occasional shortwaves. Moisture will increase late
Saturday with a returning southerly flow. Shower chances will
increase with it late Saturday into Saturday night with slighter
better chances for a few thunderstorms in the western interior
developing along a passing warm front.

Rain chances increase early Monday into Monday night then linger in
the forecast through Wednesday. A Great Lakes low will lead to a
stalled boundary that will pass as a warm front on Monday, then
bring a cold front Tuesday or Wednesday as it tracks into Canada
and/or New England. The warm front will bring us into the warm
sector of the system and bring a chance for thunderstorms across the
area late Monday into early Tuesday. The pressure gradient front the
low passing to the north may lead to breezy conditions late Monday
into early Tuesday. Guidance varies somewhat on the timing and
location of this system so have kept chance POPs throughout Tuesday
and Wednesday. Temperatures will be closer to seasonal Monday
through mid-week aided by an approaching and deepening trough.

&&

.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
Weak surface high pressure will remain just offshore tonight,
then drift farther out to seas late tonight into Thursday as a
cold front approaches.

VFR with sea breezes now in at all coastal/metro terminals.
Winds sustained up to 15 kt at KJFK/KLGA, and a few gusts 15-20
kt possible at KEWR/KTEB/KLGA/KHPN.

Winds diminish to under 10 kt tonight. Weakening convection
moving in from the west could impact KSWF late this evening with
thunder possible there or nearby, then some passing showers
farther east overnight.

Main shower/tstm impact from the NYC metros north/west now
looks to be in the morning from about 12Z-16Z give/take an hour,
reaching KBDR/KISP from 13Z-17Z. MVFR cond likely and brief IFR
vsby possible with this activity, and gusty winds and some hail
also possible with the stronger cells. Before that, some low
stratus and fog with IFR cond expected at KBDR/KISP/KGON late
tonight into Thu morning.

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

No unscheduled AMD expected.

OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY...

Thursday afternoon: Showers/tstms with IFR cond and gusty winds
possible especially for KSWF/KHPN.

Thursday night: Chance of showers and possibly a tstm, with MVFR
cond possible.

Friday: VFR.

Saturday: Chance of afternoon/evening showers and possibly a
tstm, with VFR cond possible.

Sunday: Mainly VFR.

Monday: Chance of showers and possibly a tstm, with MVFR
cond possible.

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

&&

.MARINE...
Winds and waves will generally remain below SCA criteria through
Thursday night, with wind gusts potentially briefly reaching 25 kt
this evening. A cold front approaches late tonight and slowly moves
through the area on Thursday. Some showers and thunderstorms ahead
and along the front are possible tonight through Thursday night,
with the highest chances being Thursday morning/early afternoon.

Sub-SCA conditions are then expected through Monday night.

&&

.HYDROLOGY...
Thunderstorms are possible tonight through Thursday, with potential
for heavy downpours mainly during Thursday morning/early afternoon.
At this time, no hydrologic impacts are expected through the middle
of next week.

&&

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

&&

$$

SYNOPSIS...BR/JT
NEAR TERM...BR/JT
SHORT TERM...JT
LONG TERM...BR
AVIATION...BG
MARINE...BR/JT
HYDROLOGY...BR/JT