000
FXUS61 KOKX 022229
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
629 PM EDT Tue Apr 2 2024
.SYNOPSIS...
A warm front continues to slowly approach from the south tonight.
Low pressure forms and strengthens to the southwest early Wednesday
and then moves over or just south of the area Wednesday evening
through Thursday morning. The low will drift slowly east of New
England later this week into Saturday, with high pressure building
in early next week.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
A warm front will continue to slowly approach from our south tonight
as strong surface and upper low slowly spins in place over the
Great Lakes. Widespread light to moderate rain can be seen on
radar and is the first of two heavier rounds of rain our area
will see over the next 36 hours. Through tonight an additional
0.5 to 1 inches of rain is possible, with rates mainly around
0.10 to 0.20 inches per hour. See hydrology section below.
Easterly flow will continue and strengthen overnight. Gusts along
the coast will likely reach 30 to 35 mph. Temperatures don`t drop
too much overnight with the strong easterly flow, rain and cloud
cover. Expect lows in the upper 30s to low 40s.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/...
Upper level low and associated surface low continue to spin in
place over the Great Lakes Wednesday through Wednesday night.
Low pressure then forms along a frontal boundary near the Mid-
Atlantic extending southeast of the low over the Great Lakes.
This low looks to strengthen and pass over or just south of our
area deepening to around 985mb. This low will bring another
round of moderate to locally heavy rain as well as high winds.
Model winds have increased over the past few runs and have bumped
forecast winds up. Both the 12z NAM and GFS show 65 to 75 kt at
925mb. Bufkit soundings show no real inversion in place with mean
boundary layer winds around 50 kt at several coastal locations. Have
issued a High Wind Watch for all of Long Island, NYC, coastal CT and
southern Westchester and Hudson Counties. In these areas, expecting
a period from mainly Wednesday afternoon through the first half of
Wednesday night where wind gusts could potentially reach 60 mph.
Elsewhere (except Orange County and Western Passaic County) have
issued a Wind Advisory for 45 to 50 mph wind gusts.
As previously mentioned, this low will also bring another round of
moderate to locally heavy rain to the area, as well as the potential
for isolated thunderstorms. See hydrology section below. Any
thunderstorms are expected to remain below severe criteria as
instability is real marginal. MUCAPE values will likely only be up
to a few hundred J/kg. The Storm Prediction Center has
maintained the "general thunderstorm" area in their outlook.
This low will also bring coastal flooding to the area. See
tides/coastal flood section below.
As the low pull away, cold air gets wrapped up into the system
and precip may end as a wintry mix across far northern and
western locations. At this time, there is potential for snow and
sleet to mix in. There will likely be little to no accumulation
due to marginal surface temperatures.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A blocky pattern will persist through the period courtesy of a
developing omega block over the CONUS and southern/central Canada.
Its eastern leg (the upper low associated with this week`s storm)
will be moving across Thu night, accompanied by snow/rain showers
especially in the evening. Another fairly good chance for showers
will come on Friday as a mid level vort max trailing the upper low
moves across. This disturbance will have some low level instability
to work with as model fcst sounding show steep sfc-H7 lapse rates
and available moisture above the LCL, so have bumped up NBM PoP to
at least 30 percent throughout, and while fcst does not include this
could not entirely rule out some isolated thunder and/or
graupel/small hail with some of this activity.
Another vort max pinwheeling around the slow moving upper low E of
New England should bring another chance for showers on Sat mainly
across S CT and ern Long Island. Then fair and milder wx likely for
Mon with sfc high pressure finally building in and heights rising
aloft. Siding more with slower ECMWF vs solution with a weakening
upper ridge axis sliding across, with some mid level shortwave
energy riding atop the ridge axis in the afternoon. This means there
could be a fair amt of bkn high clouds present during the time of
the solar eclipse in the afternoon.
Temps a few degrees below normal Thu night through Sat should
moderate to near normal on Sunday, then warm up to a few degrees
above normal Mon-Tue, with highs in the lower/mid 60s both days.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
A developing low pres sys will impact the area thru Wed, passing
across the region Wed night into Thu.
Rain thru this eve with mainly IFR. Breaks to lighter rain and BR
then late tngt into Wed, then heavier rain develops during the day
Wed. Mainly IFR thru the TAF period.
E winds will increase tngt, strengthening significantly on Wed.
Peak gusts to around 50 kt possible aft 18Z Wed across the NYC and
coastal terminals. Winds less further inland.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments possible thru the TAF period for changing cigs/vis.
Winds at 1000 ft around 50kt Wed aftn and eve.
OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY...
Rest of Wednesday: IFR or lower in rain. The rain could be mixed
with wet snow at KSWF late Wednesday night. E winds with peak gusts
around 50 kt possible. Winds 50kt or more at 2k ft.
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. NW flow with gusts
around 25kt.
Saturday: MVFR possible with N flow.
Sunday: VFR with N flow.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
Winds will be increasing tonight and a Gale Warning is in effect for
the ocean waters, South Shore Bays, NY harbor and the western most
Sound zone. Wind gusts up to 35 kt are expected, with waves on the
ocean waters building to 7-9 ft. A Storm Warning is then in effect
starting Wednesday morning on all waters. Strong low pressure will
pass over or just south of the waters and bring a period of 50 kt
wind gusts, mainly from Wednesday afternoon through he first half
of Wednesday night. Waves on the ocean waters likely reach 15 to 17
ft on the ocean waters and 9 to 11 ft across the Sound.
Winds drop below Gale criteria by Thursday morning, with lingering
SCA criteria. SCA cond mainly in the form of elevated ocean
seas should persist into Thu night-Fri night. Some gusts up to
25 kt are also possible in NW flow Fri afternoon and early
evening on most waters, and later into Fri night on the ocean.
&&
.HYDROLOGY...
An additional 2 to 3 inches of rainfall is expected tonight through
early Thursday. The bulk of this rain will come mainly in two
rounds, one that is ongoing through this evening and another
Wednesday afternoon through Wednesday evening. Rainfall rates
with the round on Wednesday will be mainly 0.25 to 0.5 inch per
hour rates, with locally 0.75 to 1.0 inches per hour in any
thunderstorms. Poor drainage flooding and urban low lying
flooding is possible along with minor river flooding across
quick responding rivers. The WPC has maintained a marginal risk
of excessive rainfall.
&&
.TIDES/COASTAL FLOODING...
-- Changed Discussion --
Local minor flooding benchmarks may be reached, or just
touched, late tonight/early Wednesday morning along the South
Shore Back Bays.
Around 2.5-3.0 ft of surge is needed for minor coastal flood
Wed aft/eve and around 3.5 to 4 ft for moderate coastal
flooding. With easterly winds ramp up through gale to storm
force during the time of high tide, as well as building wave
action, widespread moderate coastal flood thresholds are likely
to be eclipsed along the southern and eastern bays of LI and
along W LI Sound. Elsewhere widespread minor coastal flooding
likely. In addition, the combination of heavy rain and elevated
water levels on Wednesday afternoon into evening may cause
localized flash flooding along some shoreline roads and
properties.
Easterly winds gradually subside late Wed night as low pressure
moves over the area, and then switch to NW gales behind the low
Thu AM. High easterly swells will likely inhibit drainage,
particularly bay areas, bringing potential for widespread
moderate flooding (locally major flooding for southern and
eastern bays of LI) late Wednesday Night into early Thu morning.
The coverage and areas of greatest coastal flood impact will be
highly dependent on track of low pressure, and timing of
windshift from easterly SCA/Gales to northwest gales. Forecast
is based on a 75th percentile of Stevens, blended with ETSS,
STOFS guidance, which applies a bit of margin for safety. This
will be refined over the next 24 hours.
Along the oceanfront, breaking waves of 6 to 10 ft Wednesday
into Thursday morning, along with elevated water levels, will
result in widespread beach flooding and erosion. Scattered areas
of dune erosion with localized overwashes are likely during the
times of high tide Wed afternoon into Thursday morning.
Along LI Sound, breaking waves of 3 to 7 ft Wednesday evening,
along with elevated water levels, will result in beach erosion
with damage to shoreline structures possible. Wave splashover
over bulkheads and seawalls will likely exacerbate flooding of
shoreline roadways and properties. Similarly threat exists for
the twin forks of LI, with breaking waves of 4 to 8 ft
Wednesday evening and Thursday morning.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...Wind Advisory from 11 AM Wednesday to 5 AM EDT Thursday for
CTZ005>008.
High Wind Watch from Wednesday morning through late Wednesday
night for CTZ009>012.
Coastal Flood Warning from 4 PM Wednesday to 10 AM EDT
Thursday for CTZ009-010.
Coastal Flood Watch from late Wednesday night through Thursday
morning for CTZ011-012.
NY...Wind Advisory from 11 AM Wednesday to 5 AM EDT Thursday for
NYZ068>070.
High Wind Watch from Wednesday morning through late Wednesday
night for NYZ071>075-078>081-176>179.
Coastal Flood Warning from 4 PM Wednesday to 10 AM EDT
Thursday for NYZ071-073-078-176-177.
Coastal Flood Advisory from 2 PM Wednesday to 7 AM EDT
Thursday for NYZ072-074-075.
Coastal Flood Warning from 2 PM Wednesday to noon EDT Thursday
for NYZ079>081-179.
Coastal Flood Advisory from 2 PM to 7 PM EDT Wednesday for
NYZ178.
Coastal Flood Warning from 3 AM to 7 AM EDT Thursday for
NYZ178.
NJ...Wind Advisory from 11 AM Wednesday to 5 AM EDT Thursday for
NJZ004-103>108.
High Wind Watch from Wednesday morning through late Wednesday
night for NJZ006.
Coastal Flood Advisory from 2 PM Wednesday to 7 AM EDT
Thursday for NJZ006-104-106-108.
MARINE...Small Craft Advisory until 6 AM EDT Wednesday for ANZ331-332-
340.
Storm Warning from 6 AM Wednesday to 2 AM EDT Thursday for
ANZ331-332-335-338-340-345-350-353-355.
Gale Warning until 6 AM EDT Wednesday for ANZ335-338-345-350-
353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...BG/JT
NEAR TERM...JT
SHORT TERM...JT
LONG TERM...BG
AVIATION...JMC
MARINE...BG/JT
HYDROLOGY...BG/JT
TIDES/COASTAL FLOODING...NV