406
FXUS61 KOKX 071133
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
733 AM EDT Mon Apr 7 2025
.SYNOPSIS...
Waves of low pressure move along a stalled frontal boundary to
our south through this evening. A secondary cold front will move
across the area late tonight into early Tuesday followed by high
pressure building in from the west through Wednesday. The high
moves offshore Wednesday night. A slow moving frontal system will
likely affect the region late Thursday into next weekend.
&&
.NEAR TERM /THROUGH TONIGHT/...
Updated for current conditions. Removed the mention of snow
inland as low levels have remained warmer than forecast. Also,
adjusted probabilities to increase to near 100% with the
steadiest rain.
A stalled frontal boundary to the south of Long Island will
have a series of waves moving along it into this evening. The
waves are in association with an amplifying northern stream
upper trough that tracks slowly eastward. Temperatures have
trended warmer, and snow is no longer expected inland. Periods
of rain will continue into this evening, ending late as the
upper trough pushes the system south and east of the area. Also,
a strong cold front will begin to move into the region late
tonight/toward Tuesday morning in association of another low
tracking across upstate New York and New England.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
A strong cold front will move across the region Tuesday morning
with strong cold advection behind the front, and a strong
pressure gradient as low pressure moving off the northern
New England coast deepens, and high pressure builds to the
west. Low level winds increase to 30 to 40 kt with deep mixing
allowing for strong and gusty winds especially during Tuesday
afternoon. Used a blend of the NBM 90th percentile and the
higher MAV guidance for both the sustained winds and the gusts.
With the higher guidance, both sustained winds, and gusts remain
under wind advisory criteria. However, with the initial onset
of the strongest winds there is the potential for a few
locations along the coast to be near wind advisory criteria for
a brief period of time. Winds will then subside fairly quickly
Tuesday evening as the cold advection weakens and high pressure
builds closer to the area.
A cold airmass will be ushered in with the cold front and
below freezing temperatures are expected across the region, and
will be 10+ degrees below normal. The dry airmass and winds
remaining up Tuesday night will prevent frost formation,
however, a freeze warning is possible for Tuesday night where
the growing season has begun as of April 1st (NYC metro, Nassau
County, Hudson County, eastern Essex and eastern Union
Counties).
Tranquil weather will remain into Wednesday as the high builds
over the area.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Not much has change with regards to the long term forecast.
Brief shortwave ridging into Thu, with modified polar high building
in and across into Wed Night, will bring potential for sub-freezing
conditions outside of NYC proper Wed Night. Frost headlines may be
needed for NYC/NY metro suburbs where growing season has started,
given lighter winds and anticipated mid/upper-30 lows in these areas
Wednesday night. However, a second freeze Wed night seems less
likely. Temps generally 5 to 10 degrees below seasonable for Wed
Night.
Deep SW flow aloft amplifies Thu as a couple of PAC shortwaves dive
through the central plains towards the SE US Thu into Fri, setting
up an anomalous longitudinally deep east coast trough late week into
the weekend. Models also coming into better agreement with a
potential 3-4 std below normal 500mb upper low developing over the
Tennessee River Valley as northern stream shortwave phases in,
eventually lifting into the NE US through the weekend. At the
surface a resultant Mid-Mississippi River Valley/Ohio Valley low and
associated frontal system likely approaches the region late Thu/Thu
Night, and then likely stalls near the region Fri thru the weekend
as it becomes aligned with the N/S deepening east coast trough. This
culminates in developing southern low pressure tracking up the coast
through the weekend in response to the upper low.
Models trending into better agreement in the synoptics, but still
inherent 5-7 day model spread in location/amplitude of trough
development and timing/location/intensity of closed low development,
due to the interdependency on the interaction of several shortwaves.
This of course, will affect the exact location of the resultant
stalling frontal system, and track of coastal low.
Overall, confidence is increasing on unsettled conditions Fri into
next weekend, with potential for a period or periods of heavy rain
based on synoptic setup and potential sub-tropical moisture
connection. Given the increased confidence in this occurring, WPC has
issued a Marginal Risk for Excessive Rainfall on Day 5 (12Z Fri-12Z
Sat). Its possible, however, the timing of this marginal could
change to Saturday or be issued for both Fri & Sat, given the
general consensus of models having the highest PWATs around Fri
Night. Have increased POPs to likely for Fri night as a result.
Overall though, predictability on rainfall details is inherently low
at this timeframe (see hydrology section), with increasing detail as
the week progresses.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
A stationary front remains south of the area today as a wave of low
pressure track through the area along this boundary. The wave of low
pressure exits east tonight with a cold front pushing through
tonight. High pressure sets in tomorrow.
Conditions this morning will be MVFR dropping to IFR, then remaining
IFR most of the day. Brief periods of LIFR are possible. Light rain
lasts until 00Z. Following the end of the rain, IFR, with possible
LIFR, may stick around until 6-9Z. The winds pick thereafter,
brining things back to VFR. VFR remains into Tuesday. Snow mixing
with rain has been removed from KSWF due to temperatures being
warmer than anticipated. It is now all -RA.
Winds NE 5-10 kt today. Winds turn N this evening around 5 kt or
light and variable. WInds later tonight become WNW behind a passing
cold front and quickly increase in speed. 15-20 kt, G 20-25 kt by
early tomorrow morning becoming 20-25 kt, G 30-35 mid/late morning
into afternoon tomorrow.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments likely for changing flight categories today.
Timing of flight category improvements tonight is low confidence.
Whenever winds pick up following a cold frontal passage is when
categories are expected to begin improvement.
.OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY...
Tuesday Night: VFR. Winds diminish into the night.
Wednesday-Thursday: VFR.
Friday: VFR-MVFR with a chance of showers.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
No changes to winds and seas at this time.
A SCA continues on the ocean waters east of Moriches Inlet
through early this evening as south to southeast swells keep
seas elevated. Across the waters from Fire Island Inlet to
Moriches Inlet seas may at times near 5 feet this morning with
the swells, however, with mainly the eastern portion of the zone
being affected, and the infrequency of higher seas, have not
issued an advisory for these waters. Ocean seas may build to SCA
levels late tonight into Tuesday morning, however, with
increasing winds and gusts in the wake of a cold frontal
passage, reaching to gale force across all the waters by Tuesday
afternoon have continued the gale watch from Tuesday morning
through early Tuesday evening. Once gale gusts end a period of
SCA gusts will be possible on the non ocean waters through
Tuesday evening. On the ocean waters once gales end SCA
conditions will continue into Wednesday morning.
Winds are waves are expected to remain below SCA criteria
Wednesday night through Friday night. Waves on ocean zones could
climb 5-6 feet on Saturday.
&&
.HYDROLOGY...
There are no hydrologic concerns through Thursday.
Low predictability on hydrologic concerns for late week/next
weekend with potential for a long duration rain event Friday-Sat
Night period. NBM probs are showing a 25-35% prob for 1" in 24
hrs and 5- 10% prob of 2" in 24 hours during the Fri-Sat Night
period.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Gale Watch from Tuesday morning through Tuesday evening for
ANZ331-332-335-338-340-345-350-353-355.
Small Craft Advisory until 8 PM EDT this evening for ANZ350.
&&
$$
SYNOPSIS...BR/MET
NEAR TERM...MET
SHORT TERM...MET
LONG TERM...BR
AVIATION...BR
MARINE...BR/MET
HYDROLOGY...BR/MET