078
FXUS61 KOKX 230208
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1008 PM EDT Wed May 22 2024

.SYNOPSIS...
A cold front approaches overnight and slowly moves through the
area Thursday and Thursday night, 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 TODAY/...
Did not have to adjust PoPs as convection moving out of NE PA
and into the Mid and Lower Hudson Valley weakens and stratifies,
although a few showers could scrape far northern and
northwestern locations for a couple of hours. Thus POPs after
midnight remain unchanged from the original forecast. Basically
stuck with the fx database with only slight adjustments to
temps, dew points and clouds based on latest satellite 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 warm 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.

The next best chance / likelihood for showers and thunderstorms
will be as the cold front starts to slowly move through the
area Thursday morning. 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 marginally
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 reinitiate convection.
We will likely see just a few 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 /TONIGHT THROUGH FRIDAY/...
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 NIGHT THROUGH TUESDAY/...
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 /02Z THURSDAY THROUGH MONDAY/...
Weak surface high pressure will drift farther out to seas overnight
into Thursday as a cold front approaches. The cold front slowly
pushes through Thursday night.

Winds will remain under 10 kt overnight with many inland terminals
getting being closer to 5 kt. Weakening convection moving in from
the west could yield a shower or two for KSWF. Any showers will be
less likely to move further east into the city and eastern terminals
into the early portion of the overnight.

Main shower/tstm impact from the NYC metros north/west looks to
be in the morning from about 13Z-16Z give/take an hour, reaching
KBDR/KISP from 14Z-17Z. MVFR cond likely and brief IFR vsby
possible with this activity, and gusty winds and some hail
cannot be ruled out with any stronger storms. Before that, some
low stratus and fog with IFR cond expected at KBDR/KISP/KGON for
the overnight into Thu morning.


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

No unscheduled AMD expected through 06z. Amendments may be
needed towards the Thu morning push if thunderstorm activity
arrives earlier than expected.

OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY...

Thursday night: Chance of showers and possibly a tstm, especially
for the evening, 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...JE/JT
SHORT TERM...JT
LONG TERM...BR
AVIATION...JE
MARINE...BR/JT
HYDROLOGY...BR/JT