769
FXUS61 KOKX 041727
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1227 PM EST Tue Mar 4 2025
.SYNOPSIS...
High pressure off the Mid Atlantic coast will slowly move
farther offshore through tonight. As strong low pressure moves
northeast through the upper Great Lakes region on Wednesday, a
pre-frontal trough will approach and move across in the
afternoon and evening, followed by a cold front late Wednesday
night into Thursday morning. The front will move farther to the
east Thursday night, with high pressure gradually building in
and passing to the south through Friday. A weak frontal system
then passes through on Saturday. Another low pressure system
should pass well to the south on Sunday as weak high pressure
moves in through early next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
A cloud deck associated with mid level WAA has overspread the
region, and updated cloud cover to reflect this. Despite the
clouds, today should be noticeably milder via SW-S return flow
around the offshore high, with highs in the lower 50s from NYC
north/west, and mid/upper 40s across Long Island and S CT where
there sill be more marine influence.
A few showers well in advance of the approaching frontal system
could approach areas well NW of NYC late tonight. Low temps
will range from the lower 40s across NYC metro and Long Island,
to the mid/upper 30s elsewhere. Those lows may occur around
midnight, with temps holding steady or slowly rising overnight
with continued WAA.-- End Changed Discussion --
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
As the strong low tracks to our northwest, a pre-frontal trough
will approach and then pass through from Wed into Wed evening.
Light overrunning rainfall expected in the morning and early
afternoon from NYC north/west, then deep strong lift combines
with anomalous moisture to bring a period of moderate to locally
heavy rain as the pre-frontal trough moves across. Strong
southerly flow will bring in a plume of moisture characterized
by PW around 1.25 inches and sfc dewpoints in the upper
40s/lower 50s. Rainfall rates over 1/2 inch an hour could lead
to some nuisance urban and poor drainage flooding. Some rumbles
of thunder may be possible in the evening from the NYC metro
area west, then again late at night across ern Long Island/CT as
additional rain bands move up from the south with a weak wave
of low pressure developing along the pre-frontal trough.
Strong winds are also possible with this system. LLJ peaks over
the area Wed night with 60-70 knot speed max between 900-950
mb. A strong sfc-based inversion will be in place, and the
question will be how much of this can mix down. Taking 50-60%
of the 925 LLJ leaves us just short of wind advisory criteria
over NYC, Long Island, and coastal CT, with peak gusts over 40
mph.
After the pre-frontal trough moves east, still expect chance of
showers into Thu with the passing cold front and lagging upper
trough/low level cyclonic flow, especially across Long Island
and S CT. Winds shift W after cold fropa but the pressure
gradient looks to remain weak until late day or early evening
as winds veer NW and increase to 15-25 mph with gusts 25-35 mph.
Temps on thu remain mild, with highs in the 50s, then falling
back to the upper 30s to mid 30s Thu night.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
Key Points:
* Windy conditions are expected to continue on Friday,
especially in the morning and early afternoon.
* A weak frontal system passes across the area on Saturday, but
mainly dry conditions are expected.
* Another low pressure system is expected to pass well to the
south on Sunday, but dry conditions should prevail into early
next week.
Deep low pressure will spin across the Canadian Maritimes on
Friday as high pressure builds towards the region. The
pressure gradient is quite steep, especially Friday morning
supporting continued potential for gusts 30-35 mph. The gradient
begins to relax in the afternoon and especially Friday night
allowing winds and gusts to weaken considerably compared to the
morning. High temperatures will be slightly above normal in the
middle to upper 40s for most spots with around 50 in the NYC/NJ
metro.
A flat shortwave and associated weak low/frontal system rapidly
approach Friday night and pass across the region the first half
of Saturday. There is very little forcing and limited moisture
to support precip development. Have maintained a slight chance
Saturday morning for now, but it is possible that nothing more
than a few sprinkles occur with clearing conditions in the
afternoon. High temperatures look similar to Friday.
Most of the models have been in good agreement on a southern
stream low pressure passing well to our south on Sunday. The
latest ECMWF, UKMET, CMC, and ICON as well as much of their
ensembles continue to agree with this scenario. Earlier runs of
the GFS (12z and 18z March 3rd) shifted much further north due
to phasing with the northern stream. This scenario would bring
potential impacts to the region. However. the latest 00z GFS has
shifted back to the south, keeping the streams separated
allowing the low to pass off the Carolina coast. Have continued
follow a consensus excluding the GFS which yields PoPs below 15
percent. The passage of the northern stream trough at some point
Sunday could increase clouds, but conditions should remain dry.
The air mass on Sunday looks much cooler with highs below
normal in the upper 30s to lower 40s. The upper trough axis
shifts offshore early next week with high pressure building to
our south. Temperatures on Monday likely moderate, but still
remain below normal in the lower to middle 40s.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
-- Changed Discussion --
High pressure is pushing offshore as a storm system slowly
approaches through Wednesday morning.
VFR through about 12Z Wednesday, with MVFR developing toward 12-14Z.
MVFR is then likely with the chance of IFR, especially at some of
the northwest terminals late Wednesday morning. Also, light rain
cannot be ruled out, especially northwest of the NYC metro late
Wednesday morning into the early afternoon. This was handled with
tempo groups for -RA.
S winds 10-15 kt with some gusts to 20-25 kt this afternoon. Gusts
will drop off 22Z-00Z. S winds should briefly weaken tonight before
increasing and becoming gusty Wednesday morning.
LLWS is likely at all terminals late tonight into Wednesday.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments likely with regard to the timing of lowering flight
categories Wednesday morning.
.OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY...
Wednesday and Wednesday night: MVFR becoming IFR, rain prevails in
the afternoon and evening. Isolated thunderstorms possible. LLWS. S
winds increasing to 15-25 kt with some gusts around 40 kt,
especially south coastal terminals. Peak winds occur for the late
afternoon and evening. Winds subside gradually late Wednesday night.
Thursday: Mainly VFR. Gusty WNW winds developing in the afternoon,
increasing to 15-20 kt G25-35 kt
Friday: VFR. W winds G25-30kt.
Saturday: VFR with W winds G15-20kt possible.
Sunday: VFR with NW / W winds.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Minor updates to the winds and gusts this morning to reflect
current conditions and trends.
SCA remains in effect for the ocean waters for this afternoon
and tonight. A developing long fetch S flow should increase to
20 kt with some gusts up to 25 kt by afternoon, also building
ocean seas to 5 ft. Gusts may abate Tue night as a low level
inversion develops, but sustained flow near 20 kt should
maintain hazardous ocean seas of 5-6 ft.
Have upgraded the Gale Watch to a Gale Warning on the ocean
waters as S winds should increase to 25-30 kt and some gusts
over 35 kt. Gale Watch remains in effect for the non ocean
waters as there is still some uncertainty as to whether these
stronger winds will make it there as well. Meanwhile ocean seas
should build to 7-10 ft by evening and peak at 8-12 ft by
midnight.
Winds should subside for most of daytime Thu, then increase in
the evening with a steepening pressure gradient. Gales are
possible on the ocean waters Thu night into Fri morning, with
SCA conditions on the remaining waters.
Winds begin subsiding Fri afternoon and should be below SCA
levels Fri night. Seas will also be subsiding through Fri night,
but could remain around 5 ft E of Fire Island Inlet through
early Sat. Conditions should then remain below SCA levels on
Sat.
&&
.HYDROLOGY...
A frontal system impacting the region Wednesday and Wednesday night
should produce QPF of 3/4 to 1 1/4 inch, with the higher totals
expected inland. Rainfall rates could approach 1/2 inch per hour
in spots at the time of heaviest rainfall, which could lead to
nuisance urban and poor drainage flooding.
&&
.TIDES/COASTAL FLOODING...
Astronomical tides will remain low through the end of the week.
Intensifying southerly flow ahead of a strong storm system will
increase tide levels during the Wednesday night/early Thursday
morning high tide. Surge of 1.5 to 3 ft is needed to reach
minor flooding benchmarks. The strongest winds may actually
occur before high tide, limiting the surge somewhat during high
tide. Most locations should remain at or below action stage.
However, some of the most vulnerable locations across the south
shore back bays and western Sound could touch minor flooding
benchmarks.
Large breaking waves 8-12 ft are forecast Wednesday into
Wednesday night along the oceanfront, with beach flooding
possible.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None.
NY...None.
NJ...None.
MARINE...Gale Watch from Wednesday afternoon through late Wednesday
night for ANZ331-332-335-338-340-345.
Small Craft Advisory until 6 AM EST Wednesday for ANZ350-353-
355.
Gale Warning from 6 AM Wednesday to 4 AM EST Thursday for
ANZ350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...BG/DS
NEAR TERM...BG/MET
SHORT TERM...BG
LONG TERM...BG/DS
AVIATION...JE
MARINE...BG/DS
HYDROLOGY...BG/DS
TIDES/COASTAL FLOODING...