000
FXUS61 KOKX 021449
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1049 AM EDT Tue Apr 2 2024
.SYNOPSIS...
A warm front approaches from the south and west through today.
A complex low pressure system moves through the region
Wednesday into Thursday morning, then meanders along the New
England coast through Friday night. This low moves east Saturday
through early next week as high pressure builds to the west.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Rain continues to overspread the area from west to east this
morning. The forecast is on track.
Models are in fairly good agreement with isentropic lift
increasing this morning into this afternoon as the weak low
ejects off the Delmarva peninsula. This will mean a period of
moderate rainfall for the area, which could be briefly heavy, at
times. This area of moderate rainfall will affect the western
half of the forecast area during the morning, and the eastern
half during the late morning and afternoon hours. The best
chances for this may occur in NE NJ, NYC metro and western LI
where the 00Z HREF indicated a 30-50% 10 km neighborhood
probability of seeing at least 0.25"/hr.
There may be a brief respite, or rainfall will be light for the
first half of tonight, before another batch of moderate rain
moves into western portions of the forecast area once again
late tonight into Wednesday morning.
A low level jet will gradually increase late tonight, with a
50-60 kt jet between 950 and 900 hPa developing over the CWA by
late Wednesday morning and afternoon. This will help in
enhancing the precipitation, along with introducing breezy
conditions toward daybreak and further lead to increasing winds
through the day on Wednesday. Easterly winds at daybreak
Wednesday will be 20 to 25 mph sustained with gusts up to 30
mph.
Clouds and rain will keep high temperatures below normal for
this time of year. Highs will only be in the upper 40s to around
50. Lows will once again be above normal due to cloud coverage,
ranging from the upper 30s to upper 40s.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/...
A strong coastal low develops Wednesday and moves east to
northeast Wednesday night into Thursday. This low will moderate
to occasionally heavy rainfall with a marginal flood threat
Wednesday. Minor urban and poor drainage flooding possible.
Easterly winds at daybreak Wednesday will be 20 to 25 mph
sustained, with gusts up to 30 mph. Winds will be east with the
highest gusts Wednesday afternoon into the evening. Winds could
be as high as 30 mph sustained, with peak gusts up to 50 mph.
Winds diminish and become northeast Wednesday night.
Clouds and rain will keep high temperatures below normal for
this time of year. Highs will only be in the upper 40s to around
50. Lows will once again be above normal due to cloud coverage,
ranging from the upper 30s to upper 40s.
Minor coastal flooding benchmarks may be approached Wednesday
morning at a few south shore back bay locations. A better chance
of reaching minor coastal flooding along the south shore will be
with the late Wednesday night/early Thursday morning high tide
cycle. Minor flooding will also be possible in the western Sound
during the early morning high tide cycle.
As the low passes over and then moves northeast of us Wednesday
night, strong 850mb cold advection takes place, but it will
likely not be enough to lead to any changeover in precip types,
with the exception of a few flakes mixed in in Orange and/or
Putnam Counties.
Wednesday night and early Thursday morning there will be a
chance for isolated thunder, with the best chances across
southern and eastern zones. It is in these zones that some
models suggest greater than 500 J/kg of MUCAPE. SBCAPE looks
low, and given the setup, any thunderstorms would be elevated.
The confidence of seeing thunderstorms is low, but there is
higher confidence we may see some over the ocean.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
No significant changes have been made to the long term forecast.
With a large upper low becoming closed and the upper trough
nearly cutoff, as an omega pattern sets up, the surface low
meanders along the New England coast into late in the weekend,
before shifting east as another trough digs along the eastern
Canadian coast. Dry weather is expected into Monday as high
pressure builds slowly in from the west.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
A few waves of low pressure approach along a front south of the
area during the TAF period. The stronger wave of low pressure
approaches late in the TAF period.
Rain will overspread the area today, with light to moderate
rain continuing into tonight. VFR/MVFR becoming IFR this
afternoon. IFR conditions will be mainly for ceilings, and will
stay through the remainder of the TAF period.
Winds will increase to 10-15 kt with gusts developing in the
afternoon near 20 kt. Winds gradually pick up tonight, getting
more neat 15-20 kt sustained with gusts rising to near 25 kt.
Highest gusts will be along the coast.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of flight category changes today may be off by 2-4
hours.
Onset time of gusts this afternoon may be off by 1-3 hours.
OUTLOOK FOR 12Z WEDNESDAY THROUGH SATURDAY...
Wednesday: IFR or lower in rain. E-ENE G30-40 kt, strongest
across the coast in the afternoon and evening. The rain could be
mixed with wet snow at KSWF late Wednesday night. LLWS
possible.
Thursday: MVFR or lower with lingering rain, possibly mixed with wet
snow at KSWF. NW gusts 20-25 kt.
Friday: Mainly VFR. Slight chance of showers inland. NW G20 kt.
Saturday: Mainly VFR. NW G15-20 kt.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Increasing easterly flow on the harbor, western and central
ocean zones, the south shore bays, and western Sound have
prompted SCA for this afternoon. As easterly winds increase
later for eastern areas, SCA is not needed for today. As winds
continue to increase, a Gale Warning has been issued for the
western waters for tonight through the first half of Wednesday
night as a low level jet increases over the forecast area,
bringing winds of 35 to 40 kt. The Gale warning starts Wednesday
morning for the eastern waters, with a SCA in effect for
tonight. Waves increase beginning today and continuing into
tonight to 4 to 8 ft on the ocean, and 3 to 5 ft on the Sound
and into east portions of lower NY harbor.
Gale conditions look to be likely across all the waters
Wednesday, especially in the afternoon, and a Gale Warning has
been posted for Wednesday into Wednesday evening. As the low
begins to move east Wednesday night winds and seas will be
quickly diminishing with a period of SCA conditions into early
Thursday on the non-ocean waters, and SCA conditions remain on
the ocean waters through Friday, and possibly into Friday
evening. Conditions are then sub SCA late Friday night into
Saturday night.
&&
.HYDROLOGY...
Around 1.5 to 3 inches of rain is forecast today through
Thursday. There will be two rounds of more significant rainfall,
one today, with 0.5 to 0.75 inches possible, and another
Wednesday into Wednesday evening with 1 to 1.5 inches possible,
when moderate to briefly heavy rainfall is possible. There is a
marginal risk for excessive rainfall during Wednesday with poor
drainage flooding and urban and low lying flooding possible.
&&
.TIDES/COASTAL FLOODING...
Astronomically, by the middle of this week, we will be past the
halfway point between the full and the new moon cycles. There
will be an increase in the tidal levels around high tide. This
combined with a long period swell and increasing long fetch
easterly flow will lead to increased water piling.
Local minor flooding benchmarks may be reached, or just
touched, late tonight/early Wednesday morning along the South
Shore Back Bays. A higher chance to reach minor flooding will
be with the late Wednesday night/early Thursday morning high
tide cycle. Some moderate coastal flooding will be possible as
well. And minor flooding will also be possible across the
western Sound with the early Thursday morning high tide cycle.
We will need around 2.5 ft for minor coastal flood Wednesday
night/early Thursday in terms of surge and around 3.5 to 4 ft
for moderate coastal flood Wednesday night/early Thursday in
terms of surge.
Particularly it seems the South Shore Bays and parts of Western
LI Sound will have the highest of the surge with all the
easterly flow so these locations could see some moderate coastal
flooding Wednesday night/early Thursday morning.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 6 PM this evening to 6 AM EDT
Wednesday for ANZ331-332-340-350.
Gale Warning from 6 AM Wednesday to 2 AM EDT Thursday for
ANZ331-332-340-350.
Small Craft Advisory until 6 PM EDT this evening for ANZ335-
338-345-353-355.
Gale Warning from 6 PM this evening to 2 AM EDT Thursday for
ANZ335-338-345-353-355.
&&
$$
SYNOPSIS...JM/BR
NEAR TERM...BR/JT
SHORT TERM...BR
LONG TERM...
AVIATION...JMC/JM
MARINE...JM/BR
HYDROLOGY...JM/BR
TIDES/COASTAL FLOODING...