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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KOKX 231938
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
338 PM EDT Tue Apr 23 2024

.SYNOPSIS...
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A frontal system approaches tonight and moves across the area
on Wednesday. Strong high pressure then builds in Wednesday
night through the end of the week. Strong high pressure centered
over the region on Friday gradually shifts off shore into
Saturday then pushes farther south on Sunday as a low from the
western Great Lakes moves into Canada. This low brings a warm
front Saturday night into Sunday. We remain between low pressure
to the north and high pressure to the south through early next
week.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH WEDNESDAY/...
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High pressure continues to weaken through this evening as
Southerly flow increases ahead of an approaching frontal
system. Skies will start out clear but will increase, lower, and
thicken this evening into tonight as the frontal system and
associated shortwave trough move over the northeast. Most of the
night will be dry with a few showers possible in the early
morning as the associated warm front lifts north of the area.
Moisture and lift are limited and any of the showers look light.
In fact, most CAMs show the activity diminishing as it moves
eastward, likely due to dry low levels. Low temperatures tonight
will not be as cold as recent nights with lows in the 40s
across the region.

The warm front lifting north of the area in the morning will give
way to a WNW-WSW flow late morning into the afternoon. The trailing
cold front will quickly sweep across the area from NW to SE middle
to late afternoon. Forecast soundings are continuing to show some
surface instability. However, there are still hints of middle level
capping along with dry sub cloud. For these reasons, have continued
to leave thunder out of the forecast. Some isolated low topped
convection may still develop in the afternoon and could contain
gusty winds with the inverted V soundings/dry subcloud air. Dew
points should start mixing out in the afternoon, but a more
substantial drop in dew points is likely late in the afternoon
and evening. The westerly component and deep mixing should
allow temperatures to rise into the 60s across the entire area.
Wind gusts 25-30 mph are possible late in the day. Temperatures
could end up around 70 degrees in the NYC metro and urban NE NJ.
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&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
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Any lingering showers end by sunset with skies quickly becoming
clear. The main story for Wednesday night will be the much
colder air that settles over the region in response to a strong
high pressure building in from southeast Canada. Temperatures
are likely to fall into the upper 20s and lower 30s across the
interior and middle to upper 30s most elsewhere. Lows in the NYC
metro should fall close to 40 degrees. Winds will likely remain
up through the night although there is a short window early
Thursday morning just before sunrise for winds to lighten across
the interior. These areas have a higher probability for seeing
temperatures fall below freezing. Have issued a Freeze Watch for
interior S CT, Lower Hudson Valley, and W Passaic and W Bergen
from 3am through 9am Thursday. Frost will not occur due to the
dry air (dew points falling into the teens and low 20s).

Strong high pressure will then dominate the weather Thursday into
Thursday night. The center of the high settles overhead on Thursday
with winds becoming light. An unseasonably cool air mass in place
will lead to below normal temperatures in the 50s. Frost and freeze
conditions appear likely again Thursday night into Friday morning
with coldest readings inland. Modification of the air mass should
lead to more low level moisture and potential frost development.
Additional frost/freeze headlines may be needed. Lows range from the
low 30s inland to the middle and upper 30s near the coast.
-- End Changed Discussion --

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
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An Omega blocking pattern becomes established on Friday, as a
deep trough remains across eastern Canada into the northern
Atlantic, with another trough through the Rocky Mountain region
into the Plains, and a high amplitude ridge in between. As a
result, systems will be slow to move eastward into the beginning
of next week. And a northern Plains low will be slow to move
into the ridge Sunday into Monday.

With surface high pressure over the region moving offshore Saturday,
there is a lot of uncertainty with the development and movement of a
warm front Saturday night into Sunday, as ridging remains. This warm
from will be coming from a low in the western Great Lakes as it
moves into Canada to our north. Some isolated to spotty showers
could for along the warm front boundary Saturday evening into early
Sunday morning.

A deep return flow sets up for late in the upcoming weekend and
temperatures initially below normal through Saturday quickly rise to
as much as 10-15 degrees above normal Saturday night into the
beginning of next week. The warmest day looks to be Monday with the
western interior and the NYC metro warming into the low-80s, while
the rest of the region will be in the upper-to-mid 70s. Used the NBM
guidance through the extended period with the exception of POPs. A
weak low will attempt to bring more slight chance POPs to the area
on Tuesday with a cold front. Frost headlines look less likely
Friday night with the exception of the far interior.
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&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
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Weak off shore high pressure weakens tonight as a frontal
system slowly approaches from the Great Lakes and moves through
late in the day Wednesday.

Generally VFR through the TAF period. A chance of showers late
tonight/toward early Wednesday morning. There is a low chance, low
confidence, of MVFR in the showers. Best chances for any MVFR
conditions look to be between 10Z and 14Z Wednesday for the city
terminals. Even higher chances for MVFR ceilings for eastern
terminals, but still not high enough for prevailing conditions.
Added a TEMPO group for MVFR conditions for KISP and KGON. Best
timing would be between 13Z and 17Z Wednesday.

S to SE winds this afternoon and evening at 10 to around 15 kt with
gusts 20 to 25 kt. Any SE winds should shift more to the S
late this afternoon into early this evening before
gradually weakening tonight. Winds then increases again early
Wednesday morning and shift to the SW at 10 to 15 kt with gusts 20
to 25 kt. A shift to the W is expected by mid Wednesday
morning then WNW by late morning/early afternoon.


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

Gusts may be more occasional.

There is uncertainty in exact timing of shift to the S for terminals
with a SE wind. Most likely time frame is after 22Z today.


OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY...

Wednesday: VFR, SW winds 10-15G20-25kt, becoming W-NW in the
afternoon, then northerly late at night 5 to 10kt.

Thursday-Saturday: VFR.

Sunday: VFR. Low chance of MVFR in showers.

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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Strengthening S flow continues into tonight. A southerly jet
along the Jersey shore up into the NY Bight and lower NY Bay
will gust over 25 kt into this evening, so will have an SCA
continue there. SCA conditions then expand eastward across the
ocean later tonight into Wednesday with gusts up to 25 kt and
seas 5-7 ft. Winds will start weakening Wednesday night and
especially Thursday, but ocean seas will remain elevated. The
SCA remains in effect on the ocean through Wednesday night, but
may need to be extended into Thursday.

A weakening pressure gradient will otherwise lead to conditions
below SCA levels through the end of the week. High pressure
remains in control Saturday, moving offshore Saturday night,
with conditions below SCA levels through the weekend.
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&&

.FIRE WEATHER...
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SPS remains for NE NJ and Lower Hudson Valley through 8 pm
for elevated fire spread given combo of RH 25-30 percent and S
winds gusting to around 20-25 mph.

RH will be higher for the first half of Wednesday, but increasing
W winds in the afternoon will lead to falling RH values. A
wetting rainfall is not expected. Elevated fire spread
conditions may present themselves for NE NJ in the later parts
of the afternoon/early evening as gusts 25-30 mph occur and RH
values fall into the lower to middle 30s.

Min RH values will be in the lower 20s on Thursday, but winds
will be light and largely under 10 mph.
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&&

.HYDROLOGY...
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No hydrologic concerns through early next week.
-- End Changed Discussion --

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...Freeze Watch from late Wednesday night through Thursday
     morning for CTZ005>008.
NY...Freeze Watch from late Wednesday night through Thursday
     morning for NYZ067>070.
NJ...Freeze Watch from late Wednesday night through Thursday
     morning for NJZ002-103.
MARINE...Small Craft Advisory until midnight EDT tonight for ANZ338.
     Small Craft Advisory from 5 AM Wednesday to 6 AM EDT Thursday
     for ANZ350.
     Small Craft Advisory from midnight tonight to 6 AM EDT
     Thursday for ANZ353.
     Small Craft Advisory until 6 AM EDT Thursday for ANZ355.
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&&

$$

SYNOPSIS...BR/DS
NEAR TERM...DS
SHORT TERM...DS
LONG TERM...BR
AVIATION...JP
MARINE...BR/DS
FIRE WEATHER...DS
HYDROLOGY...BR/DS