-- Discussion containing changed information from previous version are highlighted. --
168
FXUS61 KOKX 210846
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
446 AM EDT Tue May 21 2024

.SYNOPSIS...
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High pressure will be in control through Wednesday. Offshore
high pressure going into midweek gives way to an approaching
cold front Thursday. The cold front moves across Thursday night
and stalls south of the region as waves of low pressure track
along the stationary front. Another cold front moves across the
region Saturday. Another frontal system affects the area early
next week.
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&&

.NEAR TERM /THROUGH TONIGHT/...
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High pressure slowly pushes off the East Coast today, but
remains over the area enough to keep the area dry. An upper level
ridge pushes east, but flattens as a an upper level shortwave
over the Great Lakes region moves east, passing well north of
the area.

Any stratus and fog will burn off early this morning, allowing
for a mostly sunny day. With full sun, today will be a warm day,
especially for the interior, where a southwesterly flow advects
a warm and increasingly more humid air mass today. Continued the
trend of blending the 50th percentile with the deterministic
NBM, which gives high temperatures in the middle 80s for
northeast New Jersey and the Lower Hudson Valley. Elsewhere,
temperatures in the 70s to near 80 can be expected, with the
immediate shore seeing upper 60s for highs thanks to onshore
flow and relatively cooler ocean temperatures. Dew points will
rise into the upper 50s to middle 60s. Lows tonight will only
drop to the 60s across New York City, northeast New Jersey, and
the Lower Hudson Valley. Elsewhere, lows in the 50s can be
expected.

There may be another round of stratus and fog, moving in from
the east. However, confidence was not high enough to include in
the forecast, but some guidance is pointing to this scenario
once again.
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&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
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The high slowly moves east on Wednesday allowing a pre-frontal
trough to approach during the day. However, much, if not all the
area, will remain dry. There is just a slight chance for showers
and thunderstorms for the extreme western portion of Orange
County on Wednesday.

Continued well above normal temperatures for Wednesday and
Thursday, with highs in the middle to upper 80s away from the
coast (approaching 90 for northeast New Jersey). The coast will
see temperatures range from the upper 60s to lower 80s for
highs on Wednesday, and a couple of degrees warmer on Thursday.

High pressure will eventually give way to an approaching cold front
Wednesday night into Thursday. The parent low attached to this front
will be weakening as it moves farther north of the Great
Lakes leading to a weakening of the cold front.

There will be a chance for showers and thunderstorms out ahead
and along the cold front for Thursday into Thursday night. The
cold front is forecast to move across Thursday night. Chances
for showers and thunderstorms decrease late Thursday night after
the cold frontal passage.

There is potential for some thunderstorms to be strong to severe
with the cold front with forecast surface CAPE values of
1000-2000 J/kg and forecast 0-6 km AGL bulk shear of 30 to 35
kt. Right now, coverage is expected to be isolated to scattered
of, mainly for points north and west of New York City. No
hydrologic concerns at this time as showers and thunderstorms
will be fast moving, really limiting total rainfall
accumulations.

The Storm Prediction Center has placed the entire area in a
marginal risk for severe thunderstorms,
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&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
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There is currently a lot of uncertainty through the extended period
with timing of a cold frontal passage Thursday night, and where this
front will eventually stall. Waves of low pressure are expected to
track along the stationary front which may bring a chance pf
precipitation, showers, and potentially thunderstorms, to the area.
Near upper level zonal flow will bring a more amplified trough north
of the Great Lakes and into southeastern Canada Saturday into
Saturday night, with another cold front approaching the region
before weakening. Then for early next week an even more amplified
trough will pass through the Great Lakes and northeast bringing a
surface low across the region. While there are chances for
precipitation during most of the extended period there will also be
periods of dry weather.
With the uncertainties have followed the NBM probabilities.
Otherwise, a warm airmass will remain across the region with
temperatures above normal Thursday night into the beginning of next
week.
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&&

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
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Weak surface high pressure remains over the area through Wednesday,
then begins to move into the western Atlantic late Wednesday night
into Thursday morning.

IFR to LIFR stratus and fog remain across most of the area, except
for the New Jersey terminals and will slowly improve from west to
east this morning. Timing of improvement to VFR is uncertain, and
will likely take longer at KISP and KGON. There is a low chance that
KGON remains MVFR through the afternoon.

What remains uncertain is:

1- How far inland does the stratus get? KEWR and KTEB may be briefly
impacted, but not KSWF.

2- How low do vsbys fall? Areas of fog were reducing visibilities to
under 1 sm, mainly east of the New York City terminals.

3- Timing of improving conditions to VFR Tuesday morning. Expect a
return to VFR between 14-18Z Tuesday. VFR then remains into later
Tuesday night when stratus likely develops once again.

A light S flow prevails through the forecast period, however winds
will be light and variable at a few locations overnight. Winds
speeds increase to around 10kt on Tuesday. Sea breeze enhancements
are expected once again Tuesday afternoon.

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

Uncertain that the stratus will develop at KEWR and KTEB. Timing of
improving conditions at KLGA may be earlier than forecast, and take
a little longer at KJFK.


OUTLOOK FOR 06Z WEDNESDAY THROUGH SATURDAY...

Late tonight-Wednesday: Mainly VFR. becoming IFR east of the NYC
terminals, and possibly at the NYC terminals. Becoming VFR during
Wednesday morning. IFR is possible again late Wednesday night,
mainly east of the NYC terminals.

Thursday: Improving to VFR in the morning, then a chance of
afternoon and evening MVFR with showers and thunderstorms.

Friday: VFR.

Saturday: Generally VFR. A chance of showers with MVFR.

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

.MARINE...
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Dense fog over the bays and the eastern sound and eastern ocean
zones continue this morning, with improvement still expected
after 11 am. There may be another round of fog tonight, but not
enough confidence to mention fog on the waters at this time.

Otherwise, sub-advisory conditions are expected across all
waters through Thursday. However, this afternoon and Wednesday
afternoons are likely to see a coastal jet produce gusts up to
20-25 kt, especially on Wednesday, and seas of 3 to 4 ft in the
NY Bight along with seas possibly touching 5 ft.

Winds and seas will be below SCA levels across the forecast waters
Thursday night through Saturday night.
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&&

.HYDROLOGY...
No hydrologic impacts expected through the forecast period.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
NY...None.
NJ...None.
MARINE...Dense Fog Advisory until 11 AM EDT this morning for ANZ332-340-
     350.
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&&

$$

SYNOPSIS...JP
NEAR TERM...JP
SHORT TERM...JP
LONG TERM...MET
AVIATION...MET
MARINE...JP/MET
HYDROLOGY...JP/MET