538
FXUS61 KOKX 042245
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
545 PM EST Tue Mar 4 2025
.SYNOPSIS...
-- Changed Discussion --
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 nearby on Saturday. Another low pressure system
should pass well to the south on Sunday as weak high pressure
moves in through early next week.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
-- Changed Discussion --
Only minor adjustments made with this update based on the latest
obs and trends. The forecast is mainly on track.
Weak warm advection tonight increases toward Wednesday morning,
and temperatures are expected to be non diurnal, falling off
into late tonight, and then holding steady or slowly rising.
With a rather dry column and little forcing do not expect any
showers through tonight.-- End Changed Discussion --
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Deep low pressure still expected to pass well to the northwest
of the region. passing through the Great Lakes and into southern
Canada, Wednesday into Wednesday night. With some increase in
isentropic lift Wednesday morning there may be a few scattered
showers that move through. However, the area should remain dry
until the pre frontal trough approaches by midday. The system
will be slow moving with a highly amplified trough and upstream
ridge. The warm front may just briefly move through late
Wednesday afternoon and be quickly followed by the cold front.
Cams are showing a developing line of showers with embedded
thunderstorms. Any thunderstorms will be elevated as a low level
cap is in place. Any with limited instability and CAPE,
thunderstorms may be more isolated. With a strong marine
influence thunderstorms east of NYC and across southern
Connecticut may be more isolated or may not even occur.The
strong southerly flow will bring increased moisture with
precipitable water values up to 1.25 inches Wednesday evening,
and continues to mention moderate to briefly heavy rain, with
rainfall rates up to 1/2 inch an hour, and possibly up to 1
inch per hour. If the heavy rainfall occurs isolated nuisance
urban and poor drainage flooding will be possible. Showers will
continue once the pre frontal trough moves through.
Strong winds are also possible with this system, but with a
strong inversion not sure how much mixing will happen, and
winds and gusts are likely to remain below wind advisory levels.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
High pressure begins to build in slowly during Thursday, however a
cyclonic flow aloft with some moisture lingers as a mid level trough
shifts through. Only a chance of showers with the overall highest
probabilities being north and east of the city and generally in the
morning. Winds will shift westerly and increase more noticeably in
the afternoon. Thinking is that this downsloping flow combined with
partial sunshine and delayed cold air advection will allow for high
temperatures to be warmer than deterministic NBM numbers. Went
closer to the NBM 75th percentile, which is a few degrees warmer.
Highs generally in the 50s.
Winds increase further Thursday night with steepening of the
pressure gradient, then winds slowly diminish during Friday. W to NW
gusts 30-35 mph are expected at night with a few gusts near 40 mph
possible. Gusts then gradually lower to 20-25 mph by the end of
Friday afternoon. Friday will be mostly sunny with highs mostly 45-
50.
Models have trended weaker and farther south with a trough and weak
low center Friday night into Saturday morning. Have gone with a dry
forecast, but still can`t completely rule out a sprinkle or flurry
during this period. Mostly sunny otherwise for Saturday afternoon
with highs in the middle and upper 40s. Model consensus then keeps a
stronger area of low pressure and associated precip well to our
south on Sunday.
A fast flow aloft brings uncertainty regarding the timing and
strength of weak clipper-type lows or troughs potentially shifting
nearby during the Sunday night through Monday period. In any case,
moisture is limited, so will go with a dry forecast for the time
being. Ridging at the surface and aloft with a SW flow then brings
us milder weather for Tuesday.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
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 afternoon - 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
&&
.MARINE...
With a frontal system impacting the waters Wednesday and
Wednesday night a strong southerly flow will continue tonight,
and possibly increase Wednesday into Wednesday night. With the
cold ocean waters mixing of higher winds aloft will be limited,
and have discontinued the gale watch for Long Island Sound and
the Long Island eastern bays, and issued a SCA Wednesday into
Wednesday night. The strongest winds will be over the near shore
ocean waters and continues the gale warning for the ocean, and
added the Long Island south shore bays, and New York Harbor. The
Harbor may be more marginal, and duration may be shorter than
the warning with gusts diminishing Wednesday evening.
SCA conds for the ocean on Thursday as seas remain elevated.
Winds pick up, and by the end of the day, some of the non-ocean
waters could see gusts near 25 kt. A steepening pressure
gradient will increase sustained winds and gusts across all
waters Thursday night before gradually subsiding through the day
Friday. A good chance of W to NW Gales on the ocean for
Thursday night into at least Friday morning. Gales possible
Thursday night elsewhere, with confidence at least high enough
to leave a mention in the HWO.
Sub-SCA conds for the non-ocean waters for Friday night, but
advisory thresholds will probably still be met on the ocean as winds
and seas take longer to subside. Sub-advisory conditions will be
likely for the upcoming weekend, but winds and seas on the ocean
could be close to criteria at times.
&&
.HYDROLOGY...
A frontal system impacting the region Wednesday and Wednesday night
should produce QPF of 1/2 up to 1 inch, with locally higher
amounts possible. Higher totals are 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.
No hydrological impacts are expected Thursday through early next
week.
&&
.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 8-10 ft are forecast late Wednesday into
Wednesday night along the oceanfront, with beach flooding and
erosion possible.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 6 AM Wednesday to 4 AM EST Thursday
for ANZ331-332-335-340.
Gale Warning from 6 AM to 10 PM EST Wednesday for ANZ338.
Gale Warning from 6 AM Wednesday to 4 AM EST Thursday for
ANZ345-350-353-355.
Small Craft Advisory until 6 AM EST Wednesday for ANZ350-353-
355.
&&
$$
SYNOPSIS...JC/MET
NEAR TERM...MET
SHORT TERM...MET
LONG TERM...JC
AVIATION...JE
MARINE...JC/MET
HYDROLOGY...JC/MET
TIDES/COASTAL FLOODING...