Issued by NWS Upton, NY
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Versions:
774
FXUS61 KOKX 030748
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
348 AM EDT Thu Apr 3 2025
.SYNOPSIS...
A warm front will lift across the area this morning. A cold front
then slowly moves through tonight into Friday. The front returns
as a warm front Saturday into Saturday night. A slow moving cold
front passes through the region Sunday into Monday. A broad area
of high pressure then builds south of the region through the
middle of the next week.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A warm front located over the Delmarva will lift towards the area
early this morning. Areas of light rain and/or drizzle are
possible before day break. The front should continue moving
north through the morning as a strengthening low level jet helps
lift it across the area. A line of convection over the Ohio
Valley and western PA early this morning will weaken as it
moves eastward. Its remnants will then pass through the area
mid to late morning. Lift is weak and there is little to no
instability available. Will continue to indicate a chance of
showers this morning and a brief moderate to locally heavy
downpour is possible. The showers will move through any given
location quickly, limiting amounts and impacts.
Another concern this morning will be potential of fog
development. The best chance of fog development appears to be
after day break as the warm front lifts north of the area
allowing warmer air to advect over the colder waters surrounding
Long Island. Areas of fog are likely by mid morning and some
locally dense fog is also possible. One negating factor is from
fairly strong low level flow helping to keep the air mixed
preventing visibilities from dropping to one quarter mile or
less.
The warm front should reside well north of the area this
afternoon. Some breaks in the clouds are possible west of the
NYC metro, but the rest of the area should remain mostly cloudy
to overcast. Some fog may persist across portions of eastern
Long Island and southeastern Connecticut as well. There are no
notable shortwaves or areas of enhanced forcing in the
afternoon, so will cap PoPs off at slight chance (20 percent).
Gusty S-SSW winds are likely, especially near the coast, with
winds 15-20 mph gusting 25-30 mph at times.
Temperatures should be able to reach the lower 70s across NE NJ,
Lower Hudson Valley and parts of NYC may touch 70 degrees this
afternoon. Elsewhere, highs should remain in the 60s with parts of
eastern Long Island and southeast Connecticut struggling to rise
above 60.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
A cold front and associated middle level energy should enter
the area late this evening into the overnight. An upper level
jet streak will also pass to the north with the region lying in
the right entrance region, favorable for some enhanced synoptic
lift. Guidance hints at a few showers with the cold front
passage. There is little to no instability available and based
on the latest trends, SPC has moved the marginal risk southwest
of our area. A rumble of thunder cannot be ruled out, but feel
coverage is limited to include for the evening. The cold front
passes south of Long Island overnight. The aforementioned lift
from the upper jet and middle level energy will combine to
produce a band of showers north of the cold front as moisture
overruns the boundary. These showers may end up most widespread
across the southern half of the area after midnight and continue
through day break. The lift wanes after day break and any
lingering showers should diminish by mid Friday morning.
Rainfall from these showers may be briefly moderate with
amounts around a few tenths.
High pressure over southeastern Canada ridges down through
the northeast Friday afternoon supporting dry conditions.
Middle and upper level moisture will continue traversing around
the periphery of a western Atlantic ridge residing to our south
through Friday night. A few breaks are possible Friday
afternoon, but overall skies remain mostly cloudy. Highs on
Friday will be in the lower to middle 60s under a light
downsloping NW flow.
Surface ridging quickly retreats Friday night allowing the
boundary to our south to begin lifting north towards the
area. This occurs as the ridge axis aloft begins to shift to
our east and upper troughing to our west starts to translate
towards the region. Much of the energy associated with the
trough as well as lift from the upper jet reside well to our
north and west. However, there should be overrunning north of
the warm front supporting mainly light rain development through
the day. The rain likely continues into a portion of Saturday
night, potentially tapering off late as the warm front begins
to lift north of the area into early Sunday morning. Have
capped model consensus PoPs off at likely for now given the
strongest warm advection and larger scale lift will be to our
north. Highs on Saturday will be slightly below normal in the
lower 50s.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
The models were generally in good agreement in the extended, so
the blended approach was used.
Periods of rain Sun into Mon as a slow moving cdfnt comes thru.
Sun will be the warmest day of the fcst period with the thermal
ridge over the area. Instability appears limited attm, and the
GFS is putting out minimal amounts of convective pcpn. As a
result, have not included tstm chances with this fcst.
A strong upr low begins to drop into the area late Mon into Tue.
The GFS suggests a weak low may spin up along the offshore
frontal boundary as it does. This would produce better chances
for additional pcpn late Mon thru Tue across the cwa,
particularly ern areas. The 00Z ECMWF does not support this
soln.
Regardless of whether low pres develops offshore, the upr low
itself should be capable of producing some shwrs with dpva and
steep lapse rates. Isold tstms with small hail possible in this
setup.
H85 drops to -10C or colder by Wed, keeping the middle of the
week somewhat cool, although deep mixing should offset somewhat
the cold airmass. Still, the guidance looks too warm during the
day, likely trending towards climo. Since we are at Day 7 with
Wed, elected to stick with the NBM for now. However, expect a
downward trend in the numbers unless somehow the pattern does
not shift as advertised over the last several days.
Most of the cwa will likely see some subfreezing temps either Tue
ngt or Wed ngt, or both. How cold will depend on wind and residual
stratocu.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
A warm front passes through this morning. A cold front reaches
the area tngt.
Conditions are expected to continue to deteriorate overnight to
IFR/LIFR in low clouds, fog, and light rain or drizzle. There
will also be a chance of showers into today. Improvement today
in the warm sector will be mainly confined to the NYC and Lower
Hudson Valley terminals this afternoon. The eastern terminals
will likely remain IFR/LIFR through the day, and lasting into
tngt.
Chances for additional showers and possibly a tstm tngt, but
probs and coverage too low to include in the TAFs attm.
SE winds becoming S/SW with the passage of the warm front
this morning. Gusts overnight will be more persistent along the
coast and may for a time drop off or be less frequent. Gusts
likely return in the warm sector this afternoon. Winds lighten
tngt invof the front.
LLWS expected today with S-SW winds 45-55 kt at 2kft.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Wind gusts late afternoon/early evening may be occasional.
Amendments for flight category changes likely thru this
morning.
Low confidence visibility forecast this morning. KJFK could
remain IFR/LIFR through this afternoon.
.OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY...
Late Tonight: Sct shwrs and possibly a tstm with a cold frontal
passage. Wind direction vrb with the front in the area.
Friday: Chance of MVFR in showers, especially in the morning
along the coast.
Saturday: MVFR to IFR with showers likely. E wind gusts 15-20kt.
Sunday: IFR in the morning, becoming MVFR. A chance of showers.
SW gusts 15-20 kt possible.
Monday: MVFR with a chance of showers, mainly in the morning.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
Areas of fog are likely to develop this morning and may continue
on portions of the waters into the afternoon, especially near
eastern Long Island. There is also a chance for the fog to
become dense at times. Confidence in the extent of any dense fog
is low at this time and have held off on an Advisory for now.
As a warm front lifts across the waters this morning, expect
sustained S winds 20-25 kt with gusts 25-30 kt on the ocean
waters. Sustained winds may be slightly weaker on the LI Sound,
LI Bays, and NY Harbor, but gusts up to 25 kt appear likely
this morning into the early evening. Have expanded the SCA to
include all of the Sound, LI Bays, and NY Harbor beginning 12z
and running it through 00z Friday. Winds on the waters will
weaken tonight with gusts to 25 kt remaining possible east of
Moriches Inlet. Ocean seas 5 to 8 ft expected today and will
slowly subside tonight. 5 ft seas likely linger east of Moriches
inlet on Friday morning so the SCA will run through 18z there.
Winds will remain below SCA levels Friday through Saturday night.
Seas may build close to 5 ft on the ocean late Saturday into
Saturday night as another warm front approaches.
The ocean will likely need a SCA for Sun and Mon, primarily for
seas, with a front passing thru the waters. Winds elsewhere blw SCA
lvls attm. Strengthening wly flow may require a SCA for all waters
Tue into Wed.
&&
.HYDROLOGY...
No hydrologic impacts expected through the middle of next week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 8 AM this morning to 8 PM EDT this
evening for ANZ331-332-335-338-340-345.
Small Craft Advisory until 2 PM EDT Friday for ANZ350.
Small Craft Advisory until 6 AM EDT Friday for ANZ353-355.
&&
$$
SYNOPSIS...JMC/DS
NEAR TERM...DS
SHORT TERM...DS
LONG TERM...JMC
AVIATION...JMC
MARINE...JMC/DS
HYDROLOGY...JMC/DS