000
FXUS61 KOKX 252329
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
729 PM EDT Mon Mar 25 2024
.SYNOPSIS...
A strong high pressure ridge over the area will gradually weaken
through Tuesday night, giving way at first to a maritime flow
around an ocean storm, and then to a weakening cold front
approaching late Tuesday night into Wednesday. Low pressure will
develop along the Atlantic seaboard on Thursday, eventually
tracking into the Canadian Maritimes over the weekend.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
-- Changed Discussion --
The fcst is on track. NE flow between the inland ridge and an
offshore storm will gradually diminish this evening. Meanwhile,
moistening in the H8-9 layer above a sfc-based inversion should
lead to an increase in low clouds, affecting SE CT and ern Long
Island at first toward midnight, then spreading eastward to most
of the rest of the CWA overnight. Low temps tonight will range
from 25-30 inland NW of NYC (a few degrees below normal), to the
lower 30s most elsewhere, to the mid 30s in/just outside NYC
(both near normal).-- End Changed Discussion --
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
Shallow moisture trapped under an inversion keeps us cloudy
through this time frame. Weak lift arriving from the east also
introduces slight chance of some light rain or drizzle over Long
Island and S CT mainly in the afternoon on Tue, then spreading
to the rest of the CWA with PoP increasing to 30-40%.
High temps in the maritime environment on Tue will be well below
normal, only in the 40s, while nighttime temps Tue night will be
a couple of degrees above normal.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Residual light rain and dz is expected on Wed. The models are
attempting to clear it out during the 2nd half of the day, but
this may be a case where the wetter NAM in the llvls is the
better soln. With weak wind fields in place and no strong lift
to produce pcpn, have kept the dz in the fcst all day except for
the extreme wrn portion of the cwa.
Wed ngt and Thu include a good deal of uncertainty despite the
fairly short time horizon. This is due to the upr trof and
pcpn chances ahead of the main low. This event, per the 12Z
models, resembles a pre minus the tropical moisture, with a
chance of a corridor of rain ahead of the main low. Timing of
this is Wed ngt into Thu, followed by more rain with the main
sfc low which should develop invof the Carolinas Thu and pass E
of the cwa Thu ngt into Fri. A round of rain is likely with this
main low, putting aside any large track deviations to the
right. Timing is centered on Thu and Thu eve. The consensus NBM
has about a 80-90 pop for most of the cwa, ern areas favored.
Stuck with these numbers for the fcst.
Winds on the back side of the sys develop Fri. With the track
and timing uncertainty comes the wind uncertainty as well. The
operational GFS is slower than the GEFS mean. Slower generally
equates to deeper in this case, with the slowest ensemble
members dropping the low around 975 SE of Cape Cod on Fri. The
mean at this time however has the low near downeast ME. CONSALL
was used for winds which brings a NW flow around 15-25 mph with
gusts around 35 mph, but there is room for upward adjustment.
If the storm wraps up further S, there could be some snow before
the sys exits. Right now this is a low prob, but if a 970s low
E of ACK materializes, would expect to see some snow in at
least portions of the cwa.
The flow flattens out over the weekend into Mon, but there is
still a chance for some bouts of rain with any energy embedded
in the flow. Low pops per the NBM, but the 12Z GFS is dry, and
the 12Z ECMWF is dry until late Mon.
The NBM was used for temps with minor adjustments.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
High pressure over the terminals slowly weakens into
Tuesday.
VFR through around midnight with MVFR ceilings spreading east
to west through early Tuesday morning. Ceilings slowly lower
through the day, but should remain MVFR into the evening. IFR is
possible at KGON late afternoon and evening. IFR is possible at
NYC terminals after 00z Wednesday, but have just gone SCT008
for now as confidence is low on timing and extent. There is also
a chance for light rain or drizzle late afternoon and evening,
especially east of NYC terminals.
NW winds around 10 kt this evening for NYC and Lower Hudson
Valley terminals. Further east, NE winds 10-15 kt with gusts
20-25 kt. Any gusts for NYC terminals are expected to be
occasional. Otherwise, NNE-NE winds are expected into Tuesday,
generally 10-15 kt. Wind speeds may begin to fall below 10 kt
Tuesday evening.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Any gusts at KJFK and KLGA this evening will be occasional.
Timing of MVFR ceilings overnight may be off by 1-3 hours.
OUTLOOK FOR 00Z WEDNESDAY THROUGH SATURDAY...
Tuesday Night: IFR possible with a chance of light rain or
drizzle.
Wednesday: MVFR to IFR with areas of of light rain or drizzle.
Thursday: IFR with rain likely.
Friday: MVFR early, becoming VFR in the afternoon. Chance of rain
early. NW wind gusts 20-25 kt possible.
Saturday: VFR. NW wind gusts 20-25 kt possible.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
SCA remains in effect for all but NY Harbor and the
western/central Sound per latest obs showing NE flow gusting
25-30 kt near shore or at some of the offshore buoys. and seas
6-9 ft at the buoys, and likely 5-6 ft on the non ocean waters E
of Orient. These conds likely to persist into this evening on
the bays of Long Island. Persistent NE flow on the ocean and
far ern Sound likely to last into Tue morning, then winds there
should gradually diminish Tue afternoon and night, with seas
following suit Tue night.
Light winds Wed and Thu, then increasing winds Thu ngt and Fri.
Seas on the ocean 3-5 ft on the ocean Wed and Thu. Gales are
possible on Fri. SCA will be needed on the ocean Sat, and will
be possible elsewhere.
&&
.HYDROLOGY...
Potential for hydrologic impacts late Wed night into Fri with a
general 1-3 inches of rain possible. Some higher amounts will be
possible depending on how the sys develops.
&&
.TIDES/COASTAL FLOODING...
The combination of high astronomical tides and swell/tidal
piling should bring multiple rounds of minor coastal flooding
the the high tide cycles tonight into Tue night. Advisories
remain in effect for the high tide cycle tonight and daytime Tue
for S Nassau and also S Fairfield/Westchester where water
levels will be well into the minor category, with statements
most elsewhere as water levels tough or approach minor
thresholds. Only exception will be along the SE CT coast and NE
Suffolk where water levels most likely fall short.
Forecast based on the higher of the bias-corrected Stevens
NYHOPS 50th percentile and a Stevens/ETSS blend, which both do
well in these types of situations.
Tue night could be a repeat performance. Did not lower water
levels from model fcst as was done with the previous forecast
as these types of events actually tend to hang on for at least
one high tide cycle longer than fcst.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...Coastal Flood Advisory from 11 PM this evening to 3 AM EDT
Tuesday for CTZ009.
Coastal Flood Advisory from noon to 3 PM EDT Tuesday for
CTZ009.
NY...Coastal Flood Advisory from 11 PM this evening to 3 AM EDT
Tuesday for NYZ071-073-176-177.
Coastal Flood Advisory from noon to 3 PM EDT Tuesday for
NYZ071-073-176-177.
Coastal Flood Advisory until 1 AM EDT Tuesday for NYZ179.
Coastal Flood Advisory from 8 AM to 1 PM EDT Tuesday for
NYZ179.
NJ...None.
MARINE...Small Craft Advisory until 6 PM EDT Tuesday for ANZ332.
Small Craft Advisory until midnight EDT tonight for ANZ340-345.
Small Craft Advisory until 6 AM EDT Wednesday for ANZ350-353-
355.-- End Changed Discussion --
&&
$$
SYNOPSIS...JMC/BG
NEAR TERM...JMC/BG
SHORT TERM...BG
LONG TERM...JMC
AVIATION...DS
MARINE...JMC/BG
HYDROLOGY...JMC
TIDES/COASTAL FLOODING...