721
FXUS61 KOKX 071721
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
121 PM 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/...
While it will not rain very hard today, expect periods of mainly
light rain and patchy fog as multiple waves of low pressure
pass to the south along with upper jet energy. The highest
chance will be along coastal locations where another couple of
tenths of an inch are possible, less amounts north and west.
Periods of rain will linger into this evening, primarily along
the coast, ending from west to east. Far eastern LI and
southeast CT, the rain could linger to around midnight. 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 /18Z MONDAY THROUGH SATURDAY/...
-- Changed Discussion --
Waves of low pressure move along a stationary front south of
the area through this evening. A secondary cold front moves
across the terminals late tonight with high pressure gradually
building in on Tuesday.
Mainly IFR through early this evening with periods of light
rain. There may be some fluctuations in flight categories at
times with conditions briefly becoming MVFR, but overall IFR
should prevail. The light rain should end this evening with
flight categories remaining IFR until the cold front passage
late tonight. Confidence is low for the occurrence of lower
visibilities tonight (MVFR or IFR). Improvement to VFR will
occur late tonight, prevailing through Tuesday.
NE winds 5-10 kt through this afternoon. Winds will veer to
the N and remain under 10 kt this evening and then shift to the
W-NW late tonight behind the cold front passage. W-NW winds
quickly increase early Tuesday, becoming 15-25 kt with gusts
30-35 kt. Peak gusts around 40 kt possible.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Fluctuating visibilities and ceilings possible through this
evening. Low chance for visibilities to fall to IFR.
Timing of improvement to VFR late tonight may be off by
1 to 3 hours.
Timing of wind shift behind the cold front tonight may
be off by 1-3 hours.
Peak gusts on Tuesday around 40 kt.
.OUTLOOK FOR 18Z TUESDAY THROUGH SATURDAY...
Tuesday Afternoon-Night: VFR. NW wind gusts 25-35 kt through
early evening, diminishing overnight.
Wednesday: VFR.
Thursday: MVFR possible late with a chance of showers.
Friday: IFR possible with showers likely. E-SE wind gusts
15-20 kt possible.
Saturday: MVFR or lower possible. Chance of showers. E-SE 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...
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/DW
SHORT TERM...MET
LONG TERM...BR
AVIATION...DS
MARINE...BR/MET
HYDROLOGY...BR/MET