638
FXUS61 KOKX 292342
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
742 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 will bring a shortwave
and 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, with a few slipping south
into the local area. This activity should remain relatively
limited and weak as cloud cover continues to thicken 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.

Scattered to areas of showers and thunderstorms continue to
track eastward across the lower Hudson Valley and New Jersey,
extending back into eastern and central Pennsylvania. Made some
minor adjustments to the probabilities based on current radar
and HRRR, which is bringing an area of showers through the
region overnight. Unsure what thunder activity will be
remaining as the area moves into a more stable environment
later this evening and overnight.

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 /00Z THURSDAY THROUGH MONDAY/...
Low pressure passes through tonight, followed by a post frontal
trough lingering on Thursday. High pressure builds Thursday night.

Widespread SHRA with some embedded TSRA 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. Mainly
MVFR conditions become more likely late night and into the AM push,
with a low chance of locally IFR conditions. SHRA comes to an end
from 13-16Z, west to east. Improvement to VFR by mid-day for the NYC
terminals with additional pop-up showers possible mainly after 20Z.

Wind shifts N tonight for all terminals behind the passing low
pressure with speeds under 10 kt. Wind remains N with some gusts
upwards of 20kt for Thursday. Any gusts should end towards the Thu
evening push.

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

Amendments may be needed for changing conditions through the night
with showers and any embedded thunder. Brief IFR conditions are
possible with this activity but not reflected in TAFs.

OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY...

Thursday night: Brief MVFR cond possible in the evening, otherwise
VFR.

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 guidance 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/MET
SHORT TERM...DR
LONG TERM...MET
AVIATION...JE
MARINE...DR/MET
HYDROLOGY...DR/MET
TIDES/COASTAL FLOODING...MET