535
FXUS61 KOKX 291954
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
354 PM EDT Wed May 29 2024

.SYNOPSIS...
A cold front and area of low pressure pass through tonight with a
surface trough lingering nearby on Thursday. High pressure builds
in Friday and Saturday then slowly weakens beginning on Sunday
into the start of next week. A couple of weak disturbances move
around the western side of the high Sunday night, and late Tuesday
into Wednesday.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Upper trough swinging into the Northeast today will bring a
shortwave an associated frontal system through the region into
tonight.

Scattered showers on the leading edge of the cold pool have
been pulsing in the Hudson Valley this afternoon, with a few
slipping south into the local area. This activity should remain
relatively limited and weak as cloud cover continues to thicken
into late day ahead of the approaching trough. This will
eventually bring a cold front and attendant wave of low pressure
through the region this evening and tonight, when the bulk of
the precipitation is expected.

Bands of showers and thunderstorms are already apparent on radars
to the west in Pennsylvania, and this will expand and push east
into this evening as main forcing from the shortwave arrives.
Parameters appear to limit a severe threat, with relatively weak
CAPE under 1000 J/kg and light unidirectional shear. Still, a
few thunderstorms embedded in the activity could lead to
locally heavy downpours. Latest CAMs highlight the potential for
these downpours to quickly drop an inch or two in just a couple
of hours, with the threat window primarily between 8 pm and 2
am. Should placement of this occur over the metro, nuisance
flooding is certainly a possibility, particularly in urban NE
NJ. Fortunately, 3 hr FFG values and local stream headwater
guidance is relatively high, which should mitigate more widespread
flash and riverine flooding. WPC has the entire region outlined
in a marginal risk for excessive rainfall, which seems
reasonable given the potential but localized threat. Outside of
these convective elements, overall QPF should average between a
quarter and three quarters of an inch through tonight.

Additional showers and a few thunderstorms rotate through the
region overnight into Thursday morning as the axis shifts east,
with the steadiest showers pushing into Long Island and
southern Connecticut by daybreak.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
Wet start to Thursday, particularly east of the Hudson, with
showers and perhaps a few thunderstorms lingering as the shortwave
axis moves through and a surface trough hangs back through the
region. Along with the cyclonic flow, the cold pool overhead
will likely maintain a low chance of a few pop up showers anywhere
locally into the afternoon.

Northerly flow behind the system will usher in a bit cooler
air, and with the cloud cover, should keep temperatures limited
into the low to mid 70s for most during the afternoon.
Conditions dry out entirely Thursday night as surface high
pressure builds into the Ohio Valley, setting up overnight lows
into the 40s in the coldest locales with a light northerly wind.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
No significant changes to the forecast, as generally dry
weather dominates with high pressure in control. Daytime
temperatures will be slightly above seasonal normals going into
the beginning of meteorological summer June 1, then modify
Sunday into the middle of next week as a return flow sets up.
Overnight lows will be near normal Friday night and Saturday
night, and then be a few degrees warmer Sunday night through
Tuesday night.

Strong upper ridging builds into the east coast Friday through
Saturday, then moves into the western Atlantic Sunday and weakens.
Meanwhile weak shortwaves will be approaching late Sunday with
another late Tuesday into Wednesday. Any showers and thunderstorms
with the waves will be scattered, and mainly across the western and
northern areas.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
A low pressure system approaches this evening and passes
through overnight.

VFR this afternoon into this evening. Pop-up showers developing
mainly near KSWF may approach the NYC terminals this afternoon.
By 00Z, widespread SHRA with embedded TSRA becomes likely for
the NYC terminals, gradually spreading east overnight. Best
chance for TSRA from 00-06Z for much of the terminals. KGON best
chance for SHRA and TSRA after 06Z. SHRA continues through the
night and into early morning. MVFR or locally IFR conditions
become more likely late night and into the AM push. SHRA comes
to an end from 13-16Z, west to east. Improvement to VFR likely
by mid-day for the NYC terminals with additional pop-up showers
possible after 20Z.

Generally a N/NW flow around 10 kt away from the coastal
terminals where sea breezes are allowing for a more SSW flow
around 10 kt. Wind shifts N tonight for all terminals behind
the passing low pressure remaining at 10kt or less. Wind remains
N with some gusts upwards of 20kt for Thursday.

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

No unscheduled AMD expected through late this afternoon.
Amendments may be needed for timing of SHRA or TSRA this evening
into the overnight. Locally and briefly lower categories are
possible with this activity.

OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...

Thursday: Mainly VFR for NYC terminals. Slight chance of
showers with MVFR cond possible in the afternoon. VFR at night.

Friday through Sunday: VFR.

Monday: Mainly VFR. Low chance of rain showers.

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

&&

.MARINE...
Sub-advisory conditions persist through Sunday. An increasing SW
flow during the day Sunday may allow ocean seas east of Moriches
Inlet to build to near 5 feet Sunday night. Then with a weakening
flow seas fall below 5 feet Monday. Otherwise, winds and seas across
the forecast waters remain below advisory into the beginning of next
week.

&&

.HYDROLOGY...
A general quarter to three quarters of an inch of rain is
expected through tonight, but locally heavy downpours with any
thunderstorms could quickly produce an inch or two and lead to
nuisance flooding, especially in the urban metro and northeast
New Jersey. Flash flood and headwater guidance is relatively
high and any potential flood threat would likely be localized.

No hydrologic impacts are expected Friday through the remainder of
the forecast period.

&&

.TIDES/COASTAL FLOODING...
There is a low risk for rip current development at the ocean beaches
Thursday and Friday.

&&

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

&&

$$

SYNOPSIS...DR/MET
NEAR TERM...DR
SHORT TERM...DR
LONG TERM...MET
AVIATION...MW
MARINE...DR/MET
HYDROLOGY...DR/MET
TIDES/COASTAL FLOODING...MET