okx-afd on 2025-04-09

343
FXUS61 KOKX 091536
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1136 AM EDT Wed Apr 9 2025

.SYNOPSIS...
-- Changed Discussion --High pressure through Thursday will give way to a broad area of
low pressure from Friday into the weekend. A transitory high
pressure ridge will build in on Monday. Another frontal system
may impact the area on Tuesday.-- End Changed Discussion --

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --Zonal flow aloft for the period with high pressure centered to our
south over the Mid-Atlantic, shifting offshore this afternoon. High
confidence in a dry and sunny day today that won`t feel as cold as
it did yesterday as temperatures will be a little warmer in most
cases with lighter winds.

Clouds increase tonight, helping prevent temperatures falling as low
as they did this morning. No frost/freeze headlines needed. NBM with
some minor local adjustments looked good for temps.-- End Changed Discussion --

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
Main story for the short term period will be rainfall for Friday and
Friday night, but right now potential impacts look rather limited.
Before then, a mostly cloudy but mainly dry day for Thursday.

Good agreement among the models for a digging 500mb trough to our
west Thursday night into Friday with a closing upper low that slowly
shifts east, eventually passing through this weekend. Attendant
surface low strengthens over the Mid-Atlantic Friday into Friday
night and likely shifts offshore to our south late at night. There
appears to be at least some chance of rainfall Thursday night
through Friday morning, followed by rain becoming likely generally
SW to NE across the forecast area Friday afternoon into night. Looks
like the period with the highest potential for impacts is during the
late night hours when lift could be enhanced via an east to west
oriented low level jet and perhaps some synoptic scale lift with an
approaching left exit region of an upper jet streak. Mitigating
factors for heavy rain include modest PWAT values during this time
and no strong signals for either convection occurring or for flash
flood guidance values being reached. NBM probability for 1 inch of
rainfall in a 6-hour period during Friday night is only around 10%
and has been this way for a few days now. With that said, individual
deterministic guidance from the 00z suite shows better chances of
reaching this threshold somewhere within or near the forecast area.
WPC maintains a marginal (5%) risk for flash flooding to occur here
during this period.

Models are in good agreement that the pressure gradient doesn`t get
tight enough for wind concerns at this time. The strength of the low
level jet doesn`t look too concerning either, especially with a
strong low level inversion. It will nevertheless probably be breezy
for coastal areas for both day and night. NBM looked good for
temperatures through the short term period.

.LONG TERM /SATURDAY THROUGH TUESDAY/...
The large low pressure system impacting the area into Saturday
morning should begin to push eastward with most of the heavier
precipitation ending by Saturday afternoon. The large upper level
trough that the low pressure was forced by will meander over the
East Coast through at least Sunday night. This overhead trough will
allow for the surface low pressure system, at this point centered
east of the area, to slowly occlude. The added cool air aloft will
provide for the chance for additional light rain showers through
Sunday, though any showers may end up being more scattered with some
breaks of sun.

Accompanied with the overhead trough will be temperatures that will
be largely below average. High temperatures on Saturday will only be
in the upper 40s to near 50. Some subtle moderation is expected for
Sunday with highs in the middle to possibly upper 50s.

The trough pushes to the east on Monday with a ridge forcing surface
high pressure to build in. This will result in both dry conditions
with warming temperatures through Tuesday. Highs Monday will be in
the 60s to near 70 possible for the NYC metro, with temperatures on
Tuesday in the upper 60s to low 70s for the NYC metro and NE NJ.

Another frontal system looks to impact the area as the primary low
passes to the north of the area sometime on Tuesday. This may bring
another chance of showers before the cold front ushers in cooler air
once again for Wednesday.

.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --High pressure builds into the region then slides offshore later
today.

VFR.

NW/WNW winds continue with decreasing speeds through 18Z. Wind
directions shift to the W, then SW this afternoon as the high
pressure pushes offshore. Winds become light and variable later
this evening into early Thursday morning.

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

Gusts may be more occasional through 19Z.

.OUTLOOK FOR 12Z THURSDAY THROUGH SATURDAY...

Thursday: Mainly VFR through much of the day, MVFR possible late in
the afternoon and overnight with a chance of showers.

Friday: MVFR likely with IFR possible in showers. E-SE wind
gusts 15-20 kt possible.

Saturday: MVFR or lower possible. Chance of showers. E-SE wind gusts
15-20 kt possible.

Sunday: VFR. Low end chance of an MVFR shower.

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 and seas diminish today. SCA allowed to expire for the
eastern ocean waters as seas have just come below 5 ft, and all
other zones will be prevailing below criteria through Thursday.

Next chance of SCA cond arrives late Thursday night, becoming
likely for Fri with the approach of low pressure and persisting
into Sat with ocean seas 5-8 feet expected. Any 25-kt gusts Sat
morning should diminish by afternoon. Ocean seas will remain
above 5 ft through at least Sunday night.-- End Changed Discussion --

.HYDROLOGY...
-- Changed Discussion --Rainfall from Fri afternoon through Sat afternoon of 1-2 inches
should lead to only limited minor impact.-- End Changed Discussion --

.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --CT...None.
NY...None.
NJ...None.
MARINE...None.-- End Changed Discussion --

SYNOPSIS...JC/BG/MW
NEAR TERM...JC/BG
SHORT TERM...JC
LONG TERM...MW
AVIATION...MW/JMC
MARINE...JC/BG/MW
HYDROLOGY...BG