-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KOKX 201920
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
320 PM EDT Sat Apr 20 2024

.SYNOPSIS...
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A cold front moves offshore early this evening. High pressure then
builds in through early next week before giving way to a frontal
system on Wednesday. High pressure then builds in through
Friday, followed by another frontal system next weekend.
-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
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Mid and upper level shortwave swings across New England early
this evening sending a cold front across the region. The
earlier pre-frontal trough continues to shift to the east
although it may linger near the southeast coasts as more of an
onshore component/sea breeze slows it down. Otherwise, westerly
flow has allowed temperatures to rise well into the 60s for much
of the area with some lower 70s in the usual warmer spots. Some
coastal locations will be a bit cooler with some onshore
component.

The cold front will sweep across the area late this afternoon
and early evening. There may be a few wind gusts 25-30 mph with
the frontal passage, but these are expected to be brief. Most
places will remain dry, but CAMs continue to hint at a few
showers developing across eastern CT and the east end of Long
Island early in the evening. There may be a bit more organized
convergence here with some weak CAPE to support this activity. A
slight to chance PoP seems reasonable in this set up. Any
showers will quickly diminish after sunset with the front
offshore and drier air making its way out east.

High pressure over the central states begins to build in tonight.
Mostly clear skies are expected along with colder and drier air.
The boundary layer will initially be mixed before starting to
decouple, especially inland, early Sunday morning. Temperatures
should fall into the middle 30s inland and upper 30s and lower
40s most elsewhere. There may be some patchy frost for inland
areas, but dew points in the 20s should prevent any widespread
frost development. Therefore, no Frost Advisory has been issued
at this time.
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&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
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High pressure and dry conditions will prevail Sunday through
Monday. A large upper level low will settle over southeast
Canada on Sunday carving out broad troughing across the eastern
US. A southern stream shortwave along the base of the trough
will develop a wave of low pressure along the southeast coast
through the day. A strong upper jet streak is also expected to
lie near New England, which will help to draw up middle and
upper level moisture to the north of the low. As a result,
increasing clouds will occurs Sunday morning leading to mostly
cloudy conditions for the area. Highs will end up below normal
in the 50s.

The jet streak pushes east Sunday evening allowing the southern
low to move out into the Atlantic. Clouds will decrease from
northwest to southeast leading to mostly clear skies overnight.
Another chilly night is in store with lows in the middle to
upper 30s inland and lower 40s closer to the coast. A dry
atmosphere will lead to sunny conditions on Monday with highs a
bit warmer than Sunday, but still below normal in the lower 60s.
-- End Changed Discussion --


&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
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Zonal flow aloft for Monday night and Tuesday with surface high
pressure in control of the weather, keeping us dry through the
period. Possibly some patchy frost early Tuesday morning well
NW of the city and in the Pine Barrens. High temperatures
Tuesday afternoon will be a few degrees below normal.

500mb trough digs towards the Northeast Tuesday night into
Wednesday, with a surface low center passing to our north. Shower
chances begin late at night, then showers become likely on
Wednesday with the passage of an associated cold front. High
pressure then begins to build back in behind the storm system
Thursday night and remains in control through Friday. Dry during
this time, and high temperatures both days will be a few
degrees below normal.

Models differ on the timing of the next low pressure system, which
could impact the weather next weekend. They at least agree that
a surface low heading into the Great Lakes will run into mid-
level ridging. This will help weaken the system and keep its
center to our north this weekend, with the best chance of
showers arriving with the leading warm front and trailing cold
front. Will go with a chance of showers starting mainly Saturday
afternoon, but we might be able to get through the daytime
hours of Saturday without seeing any showers. High temperatures
remaining a few degrees below normal.
-- End Changed Discussion --

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
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A cold front moves across the terminals into early this evening.
High pressure then builds in tonight and Sunday.

Rain has ended, and VFR conditions have largely returned. Exception
is KGON, which may hold on to LIFR cigs for another hour or two
before improvement. Then, VFR at all sites thru the TAF period.

Increasing SW or WSW flow veers NW toward 00Z Sun with frontal
passage. Gusts 20 to 25 kt develop between now and then, and
likely persist into the first half of the night before subsiding.
Direction backs W or WNW on Sunday with 10G20kt redeveloping by
early afternoon.

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

Timing of wind shift may be off by an hour or two.

Gusts may be more occasional on Sunday.

OUTLOOK FOR 18Z SUNDAY THROUGH THURSDAY...

Sunday PM: VFR. WNW 10G15-20kt.

Monday and Tuesday: VFR.

Wednesday: MVFR or lower with showers. S winds 10-15G20-25kt
in the afternoon/evening, becoming NW at night.

Thursday: VFR. Gusty NW flow.

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

&&

.MARINE...
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A cold front moves across the waters late this evening. There
may be a few gusts close to 25 kt on the NY Harbor, western
Sound and western Ocean with the passage of the front.
Otherwise, winds and seas will remain below SCA levels. High
pressure will otherwise build tonight through Monday. Winds and
seas are expected to remain below SCA levels given the
relatively weak pressure gradient.

High pressure should keep conditions at sub-advisory levels
through at least Tuesday morning, then gusts to 25 kt could be
possible on the ocean waters west of Fire Island Inlet in the
afternoon. The pressure gradient tightens with slowly increasing
winds Tuesday night into Wednesday, increasing the likelihood
of SCA conditions across all ocean waters during this period.
Seas on a southerly flow build up to around 5 ft on Wednesday. A
cold front then passes through, and SCA conds will still be
likely on the ocean Wednesday night. Offshore winds diminish on
Thursday along with subsiding seas. Sub-advisory conditions are
therefore anticipated by the end of the day.
-- End Changed Discussion --

&&

.HYDROLOGY...
No hydrologic impacts expected through next week.

&&

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

&&

$$

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