255
FXUS61 KOKX 151740
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
140 PM EDT Tue Apr 15 2025
.SYNOPSIS...
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A series of weak surface troughs move through this afternoon
through Wednesday. High pressure starts to gradually build in
Wednesday night, remaining in control through Thursday night. A
frontal system approaches Friday and may impact the area from
Friday night through Saturday night. High pressure returns for
Sunday. Another frontal system may impact the area late Monday.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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The frontal boundary is moving a bit slower than previously
progged, but it does pivot through and gets clear of eastern
portions of the area this afternoon. Sfc analysis is a bit
convoluted with the depiction most likely indicating a cold
front followed immediately by a strong sfc trough / area of
convergence. Not much activity expected reflectivity / shower
wise for a few hours, then late this afternoon (towards 20z or
so) widely scattered to isolated showers and thundershowers/storms
attempt to pivot through. The expectation is that the stronger
sub- severe and isolated severe storms would remain primarily
north of the area where the slightly steeper lapse rates exist.
CAMs suggesting widely scattered to isolated shower activity
overall. Cooling aloft will steepen lapse rates and allow
instability to increase a bit. When these showers first move
into the area it looks like they will likely not be able to
produce any thunder because of a mid- level cap evident in model
fx soundings around 600mb. This cap is just below the -10C to-
20C layer. Once this cap weakens by 20z or so, then about 100 to
200 J/kg of CAPE will be available in the
-10C to -20C layer and isolated thunder would be possible. With
a dry sub-cloud layer and strong mid- level flow, any stronger
showers or thunderstorms should be able to mix down with
primarily 35 to 40 kt gusts. Small hail or graupel is also
possible.
Outside of any showers or thunderstorms, the synoptic winds
themselves will be very gusty. Deep mixing is seen in model
soundings in strong CAA. The deepest mixing occurs in the western
half of the area before and approaching sunset and expecting
the highest wind gusts here. Cannot completely rule out an
isolated 45 kt gust where a strong thunderstorm develops. But
this should be the exception rather than the rule. High
temperatures this afternoon reach the 60s.-- End Changed Discussion --
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
Cyclonic flow aloft continues through Wednesday. At the surface a
series of weak troughs will move through. No precipitation is
expected from these features. Gusty winds expected again
Wednesday, but closer to 30 to 35 mph. Heights start rising
aloft Wednesday night with ridging aloft and high pressure
moving in at the surface. Light winds and clear skies expected
by Thursday night, so went straight CONSMOS guidance for now.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
A weakening ridge in the upper levels will push east of the area
Friday, while at the surface high pressure will be situated to the
south off the mid-Atlantic coast with a surface ridge axis extending
from it northward into southern Quebec. This will allow a
warm front to lift north Friday night and will be be the next
chance for precipitation. However, only light amounts of rain for
Friday night are expected at this time. The associated cold front is
expected to move through on Saturday night, with a secondary cold
front possibly moving through late Saturday night into early Sunday
morning. High pressure builds in behind the cold fronts for
the rest of Sunday.
With a building ridge moving into the region Thursday and a warm
front lifting north Friday night, a warming trend through the period
is expected. Temperatures in the 50s and 60s on Thursday will rise
into the 60s and 70s by Saturday for most areas. Cooler conditions
are expected along coastal areas. Cold air advection after the
passage of the cold front will temperatures back to near seasonable
levels for Sunday and Monday.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
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A cold front moves across the terminals this afternoon.
High pressure then gradually builds in through Wednesday.
VFR through the TAF period.
W-SW winds increase this afternoon to 15-20 kt with gusts
25-30 kt. Winds will then settle to the W becoming 15-25 kt
with gusts 30-35 kt, mainly 20z-01z. Showers are possible this
afternoon and early evening, which may contain stronger wind
gusts to 40-45 kt, especially from the NYC metro terminals on
NW. Have handled this potential with a PROB30, mainly from
19z-23z. The shower potential diminishes by 01z.
W-WNW winds will remain gusty overnight, 25-30 kt, although some
outlying terminals could see gusts briefly end or weaken early
Wednesday morning. WNW winds around 20 kt with gusts around 30 kt
expected on Wednesday.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Gusts 40-45 kt possible in scattered showers 19z-23z. An
isolated thunderstorm also possible 20z-23z.
Sustained winds and gusts likely weaken somewhat overnight, but
gusts could still reach 30 kt at times.
.OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY...
Wednesday Afternoon-Night: VFR. WNW winds G25-30kt in the afternoon
and early evening, diminishing at night.
Thursday: VFR. NW winds G15-20kt.
Friday: Mainly VFR. Chance of showers late afternoon and night,
mainly inland. S winds G15-20kt.
Saturday: Mainly VFR. Chance of showers, mainly inland. SW winds G20-
25kt.
Sunday: VFR. NW wind gusts 15-20 kt possible.
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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Have upgraded small craft advisories to Gale Warning, primarily
for gale force gusts during portions of this evening and
tonight. Small craft conditions developing quickly this
afternoon and ramp up to gales during the evening. Still a
tricky wind forecast in terms of the total duration of gales
beginning very late this afternoon and not only through tonight,
but even into Wednesday. For now only have the Gale warning
going through 10z, but this can be re-evaluated later.
Meanwhile, gusts on land could reach just below 40 kt around
western Long Island, NYC, northeast NJ and souther Westchester.
Any inversion weakens through this afternoon and stronger gusts
will be able to mix down over the open waters by tonight. There
looks to be at least 3 to 4 hours where gales are expected.
There remains the potential for short fused Marine Weather
Statements with any low top convection that attempts to get
going late this afternoon and early this evening..
Gusts continue into Wednesday but may be more marginal in terms
of gales, at least more marginal at times. Into Wednesday night
some waters will be hovering around SCA criteria, although peak
gusts do lower. Sub- SCA conditions become more prevalent later
Thursday into Thursday night.
Waves are expected to remain below SCA criteria through the
first half of Friday night but build to 4 to 6 ft late Friday to
around daybreak Saturday on the ocean. Waves continue to build to
4 to 8 ft by Saturday afternoon on a southerly flow ahead
of an approaching cold front. Waves slowly diminish thereafter
through Sunday, with all ocean zones below 5 ft by late Sunday
morning into Sunday afternoon.
Winds will remain below 25 kt through Friday, are expected to gust
25 to 30 kt kt by late Friday night into Saturday on the ocean
waters as a frontal system approaches from the west. Winds on the
ocean fall below 25 kt for Saturday night into Sunday. There is a
chance that non-ocean waters reach SCA gusts on Saturday.-- End Changed Discussion --
&&
.HYDROLOGY...
There are no hydrologic concerns through the start of next week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
NY...None.
NJ...None.
MARINE...Gale Warning until 6 AM EDT Wednesday for ANZ331-332-335-338-
340-345-350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...JP/JT
NEAR TERM...JE/JT
SHORT TERM...JT
LONG TERM...JP
AVIATION...DS
MARINE...JE/JP/JT
HYDROLOGY...JP/JT