240
FXUS61 KOKX 010738
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
338 AM EDT Wed May 1 2024

.SYNOPSIS...
A weak frontal wave pushes offshore early this morning with
high pressure returning this afternoon into tonight. Another
weak frontal system passes across the area Thursday, followed by
high pressure Friday into early Saturday. A weak frontal system
approaches Saturday and passes through late in the weekend or
early next week. A warm front approaches late Tuesday.

&&

.NEAR TERM /THROUGH TONIGHT/...
A weak frontal wave continues to push east of the area early
this morning. A few light showers remain across southern CT and
Long Island that will slowly translate east through 5 am. These
showers should push east of the area and diminish shortly after
sunrise.

A progressive and flat ridge will slide across New England
today with weak high pressure at the surface. Lingering clouds
this morning should give way to some sunshine, especially late
morning into the afternoon. Light NE flow to begin the day
should give way to a SE flow in the afternoon. There are hints
in some of the guidance for a passing shower in the afternoon
across interior CT. Feel this may be overdone, but did keep a
bit more cloud cover in this part of the region. Temperatures
are bit of a challenge again, but the usual warmer locations in
NE NJ, Lower Hudson Valley, and parts of NYC should be able to
reach the middle to upper 70s. Onshore flow should keep
locations further east a bit lower with highs in the middle to
upper 60s.

Some low clouds make a return tonight leading to mostly cloudy
conditions. The ridge axis slides to the east overnight with
another shortwave beginning to swing across northern New
England towards Thursday morning. Lows range from the middle to
upper 40s across Long Island and southeast Connecticut to lower
50s from the NYC metro on NW.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
The shortwave moving across northern New England will send a
weak frontal wave across the region on Thursday. The energy and
lift from the shortwave passes to our north and east, so not
anticipating any showers. The main forecast challenge on
Thursday will be with high temperatures and the timing of a wind
shift associated with the frontal wave. The faster guidance
would allow the winds to become more westerly in the afternoon,
especially away from the immediate coast, giving temperatures a
boost.

The NBM deterministic and statistical guidance are once again
running at or below the 25th percentile of the NBM for highs
on Thursday. The NBM deterministic and stational guidance have
verified too cool recently, especially in regimes where there is
a deeper mixing and a westerly downslope component to the wind.
Think this is another good case to blend in some of the warmer
values in the 50th percentile of the NBM for locations away from
the immediate coast. While the air mass is not as warm as
Monday, using the 50th percentile of the NBM verified well.
Forecast highs on Thursday are in the lower to middle 80s across
the Lower Hudson Valley, NE NJ, and much of the NYC metro.
Further east, highs are in the upper 60s to middle 70s. The 75th
percentile of the NBM is depicting even warmer highs in the
upper 80s for some of the warmer spots. These are possible if
the flow goes westerly several hours sooner. Warmer conditions
may also occur over Long Island and southern CT if the flow ends
up more westerly than anticipated in the afternoon.

High pressure builds across New England Thursday night and
should remain in control through Friday night. There is some
uncertainty regarding any stratus development for Thursday night
into Friday morning as an ENE flow off develops. Will go with
increasing clouds, but keep the forecast mostly cloudy for now.
At least partial clearing is expected Friday afternoon, but this
will be short-lived as clouds begin increasing again from west
to east Friday night ahead of the next frontal system and
shortwave energy. Temperatures Friday should end up close to
seasonable levels.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
An upper level ridge builds over the area on Saturday as high
pressure continues to nose down from our northeast. A weak
frontal system approaches from the west and continues to weaken
as it runs into the high. This creates a bit of a tricky PoP
forecast for Saturday, but continued previous thinking of
keeping much of Saturday dry as the upper level ridge axis
doesn`t pass through until Saturday evening. Slight chance to
chance PoPs Saturday afternoon for western locations, with
increasing PoPs through the night, becoming likely after
midnight. PoPs then continue through Sunday night. There are
some hints from the latest guidance of increased convergence
from an inverted trough/strengthening low as the system moves
through Sunday evening. This would bring a period of some
heavier rain to the area. Current NBM probabilities of seeing 1
inch or more with this event are 20 to 15 percent from west to
east, with the 90th percentile PQPF over 48 hours showing 1.5 to
1 inch from west to east.

Dry conditions are expected by early Monday morning. Brief, weak
high pressure builds in, with a weak cold front/surface trough
potentially passing through Monday evening. Heights rise aloft
slightly on Monday and expecting mostly sunny skies. This combined
with a light westerly flow should lead to some above normal
temperatures Monday. Went closer to the NBM 50th percentile as the
deterministic was closer to the 25th percentile. This gives
widespread low to mid 70s across the area.

A warm front approaches the area late Tuesday. There remains
uncertainty as to whether the warm front will remain nearby or
lift to the north late Tuesday and will thus affect
temperatures across the area. Mid level energy from the west
will attempt to break down any riding in the mid levels.

&&

.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
Weak high pressure remains in control today. Weak low pressure
approaches from the north and west tonight.

Scattered showers early this morning now east of NYC termianls.
Mainly MVFR cigs for NYC terminals and MVFR to IFR elsewhere.
Improvement to MVFR then VFR during the mid-morning hours. MVFR
cigs should take longer to improve east of NYC terminals.

N winds mostly 10 kt or less (strongest at KLGA). Late
morning/afternoon S-SE sea breezes expected at all the terminals
but KSWF.

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

AMD possible for fluctuating cigs this morning.

Low confidence in MVFR. Cigs may be mostly VFR this morning or
become VFR earlier than TAF timing.

OUTLOOK FOR 06Z THURSDAY THROUGH SUNDAY...

Wednesday night: MVFR cigs possible.

Thursday through Friday: VFR.

Saturday: Mainly VFR. Chance of showers and MVFR cond in the
afternoon and at night.

Sunday...Chance of MVFR or lower in showers. ESE winds G15-20kt.

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

OUTLOOK FOR 06Z THURSDAY THROUGH SUNDAY...

Wednesday night: MVFR cigs possible.

Thursday through Friday: VFR.

Saturday: Mainly VFR. Chance of showers and MVFR cond in the
afternoon and at night.

Sunday...Chance of MVFR or lower in showers. ESE winds G15-20kt.

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

&&

.MARINE...
A weak pressure gradient remains in place, with an extended
period of conditions below SCA levels through early next week.
Seas may reach 3-4 feet late Sunday into Monday with a weak frontal
system moving through.

&&

.HYDROLOGY...
There are currently no hydrologic concerns through early next
week.

&&

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

&&

$$

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