591
FXUS61 KOKX 291818
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
218 PM EDT Mon Apr 29 2024

.SYNOPSIS...
A back door cold front moves through the region this evening,
and becomes nearly stationary into Tuesday. A frontal wave then
moves through the area Tuesday night into Wednesday, with high
pressure returning thereafter for the end of the week. Another
frontal system is expected for the weekend.

&&

.NEAR TERM /THROUGH TUESDAY/...
Temperatures along the coast have peaked as sea breezes were
moving northward, while inland temperatures have risen into the
mid 80s. Cumulus have developed along the sea breezes and
inland, across northern New Jersey and into New York City mixed
layer CAPE of around 500 J/kg has developed along with surface
based instability. Slightly increased the probabilities of
precipitation in these areas with CAMs showing development of
convection possible as sea breeze boundaries and backdoor cold
front pushes into the region. Limiting factor will be the ridge
axis moving toward the area with dry upper levels and
subsidence.

Ridging continues to build in aloft over the eastern CONUS,
with the axis expected to be overhead sometime early Tuesday.

Today will be the warmest day of the year so far, with some
humidity too, with dew points into the lower 60s, and highs into
the lower to mid 80s for most. Bit of a tricky temperature
forecast with the timing of the front, sea breezes and any
clouds this morning being huge factors. The thinking is that
skies will be mostly sunny this morning and temps will rise
quickly with decent mixing in a northwest flow. Once the sea
breezes kick in, temperatures will drop as always this time of
the year. Long Island, coastal CT and portions of NYC and
northeast NJ will likely see their highs in the early afternoon.

With sea breeze boundaries and some energy rounding the base of
the ridge aloft, some afternoon convection is possible as
SBCAPE values will be around 500-1000 J/kg for NYC north and
west. Have added a slight chance of thunder to the forecast. The
CAMs are in pretty good agreement with the location of any
convection being NYC north and west.

Thicker cloud cover returns tonight with a moist onshore flow.
lows will be in the upper 40s in the eastern half of the area
and mid 50s in the western half.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
A frontal boundary likely remains just south of the area through
Tuesday night. As previously mentioned, the upper ridge axis will
pass overhead early Tuesday. A shortwave then approaches with
associated surface frontal wave Tuesday night. This will bring the
next shot of rain to the area with chances Tuesday evening through
the first half of Wednesday. Capped at 50% PoP for now, with the
most likely period being Tuesday night. There is also a slight
chance of thunder. High pressure starts building in from the north
and east Wednesday night.

Temperatures will be cooler on Tuesday and Wednesday than they
will be today, but still at or above normal for late April/early
May.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
No major changes were made to the forecast Thursday through the
upcoming weekend

*Key Points*

*Dry conditions expected Thursday and Friday.

*The next frontal system may impact the area for the upcoming
weekend, bringing the next chance of showers.

*Temperatures will continue running slightly above normal.

Shortwave troughing that will be moving across the region Wednesday
pushes offshore on Thursday. Upper ridging will reestablish itself
over the eastern states to end the week. Another upper trough then
lifts north out of the intermountain west on Friday, then up into
the Great Lakes over the weekend. This will send another weakening
frontal system into the area Saturday into Sunday. The modeling has
been slowing down the timing for the ridge axis to weaken or shift
east. This has also slowed down when higher probabilities for
showers exist across the region. It may take until late Saturday or
Saturday night for the ridge to weaken enough to allow the front to
enter the area. Showers are possible late Saturday into Saturday
night. Model spread increases further for Sunday with several
solutions showing ridging trying to return and the front
dissipating. There are also solutions showing the ridge moving to
the western Atlantic on Sunday with a larger upper trough trying to
edge closer to the east coast, which would act on the front to bring
higher chances of showers. Maintained the chance of showers on
Sunday based on the latest NBM. Did not include thunder as there is
too much uncertainty with the mesoscale environment at this time
range.

Temperatures Thursday and Friday will reach the lower to middle 60s
near the coast with onshore component to the wind. Further inland,
highs should reach the lower to potentially middle 70s.
Highs are much more uncertain this weekend with NBM box and whisker
plots showing ranges of highs from the lower 60s to the upper 70s,
especially away from the immediate coast. This is likely due to the
aforementioned uncertainties with cloud cover, potential showers,
and proximity of the front.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
A back door cold front approaches this afternoon and moves
through this evening.

VFR through at least 01-03z for most spots before lowering to IFR
soon thereafter. A few showers are possible late this afternoon and
early this evening and an isolated shower or thunderstorm cannot be
ruled out. Have VCSH in the TAFs to reflect this potential, mainly
for NYC metro and Lower Hudson Valley terminals. IFR conditions will
prevail early Tuesday morning with conditions to improving to MVFR
mid to late Tuesday morning.

SE-S winds this afternoon around 10kt or less. Winds then begin to
back to the ESE-E this evening and then E overnight. E-ENE winds for
Tuesday.

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

A shower, possibly a thunderstorm, may occur approx 20-01z.

OUTLOOK FOR 18Z TUESDAY THROUGH SATURDAY...

Tuesday aftn: MVFR, possibly VFR at times.

Tuesday night: Lowering to IFR with showers possible.

Wednesday: IFR early, improving to MVFR with showers possible.

Thursday-Saturday: VFR.

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

&&

.MARINE...
No changes to the winds and seas at this time.

Given a weak pressure gradient over the area for several days,
winds and waves will remain below Small Craft Advisory criteria
through the first half of the weekend.

&&

.HYDROLOGY...
There are no hydrologic concerns through the weekend.

&&

.CLIMATE...
Here are the record high temperatures for Monday, April 29:

EWR: 91/1974
BDR: 86/2017
NYC: 89/1974
LGA: 88/2017*
JFK: 85/2017
ISP: 85/2017

*Also occurred in previous years

&&

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

&&

$$

SYNOPSIS...DS/JT
NEAR TERM...MET/JT
SHORT TERM...JT
LONG TERM...DS
AVIATION...JC
MARINE...DS/MET/JT
HYDROLOGY...DS/JT
CLIMATE...