000
FXUS61 KOKX 031040
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
640 AM EDT Wed Apr 3 2024
.SYNOPSIS...
A warm front continues to approach today while low pressure
strengthens to the southwest early today then passes over or
just south of the area this 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 /THROUGH THURSDAY/...
-- Changed Discussion --
Only minor changes have been made to the forecast with this
update to account for current observations and trends. Overall,
the forecast remains on track.
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.
Most 00Z model guidance is showing a strong LLJ anywhere from 60
to 70 kts at 925mb. Bufkit soundings show a pretty high
inversion with a lot of the strong winds from the LLJ both above
and below it, so its likely a lot of the strong winds will mix
down to the surface. Have issued a High Wind Warning 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.
An additional 2 to 2.5 inches of rainfall is expected this
morning through early Thursday with locally higher totals of
3-3.5 inches possible. The bulk of this rain will fall Wednesday
afternoon and evening. A period of higher rainfall rates will be
possible Wednesday evening and early night with most around
0.5"/hr. Higher rates of 0.75"/hr will be possible.The best
location for these higher rates will be in NE NJ, NYC metro and
LI. This is the same area that a Flood Watch has been issued
for. The 00Z HREF shows a 90% 10-km neighborhood probability of
at least 0.5"/hr with some areas of 20-40% of seeing 0.75"/hr.
SOme of the higher rates may be possible in isolated
thunderstorms and could be as high as 1"/hr. Poor drainage
flooding and urban low lying flooding is possible along with
minor river flooding across quick responding rivers. WPC has
upgraded NE NJ, the NYC metro and LI to a slight risk of
excessive rainfall.
Isolated 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, though some models are
showing isolated areas of higher MUCAPE. The Storm Prediction
Center has maintained the "general thunderstorm" area in their
outlook.
This low will also bring coastal flooding to the area. See
the tides/coastal flood section below.
As the low pulls 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.-- End Changed Discussion --
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY/...
A low with meander off of the New England coast Thursday night
into Friday as it gradually weakens. This will leave general
cloud cover in the area with a slight chance for rain showers
through Thursday night into the day on Friday. Winds will not
meet hazard criteria, but may be breezy at times with the low
meandering nearby.
&&
.LONG TERM /FRIDAY 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 Sun-Tue with sfc high pressure finally building in
and heights rising aloft. Siding more with slower ECMWF vs
faster GFS solution with a weakening upper ridge axis sliding
across, and 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 /12Z WEDNESDAY THROUGH SUNDAY/...
HIGH IMPACT AVIATION EVENT TODAY INTO TONIGHT...
A strengthening coastal storm approaches today and moves across or
just south of the region tonight into early Thursday.
Expect mainly IFR conditions with rain for much of the TAF period.
There could be occasional time windows of MVFR as well as lulls in
the rain. There is isolated thunderstorm potential this afternoon
into tonight.
Increasing easterly winds and wind gusts today through this evening.
Winds are generally 10-15 kt into early morning, 20-25 kt for the
rest of this morning, 25-30 kt this afternoon into evening. Gusts
likewise generally near 20-25 kt into early morning, 30-35 kt for
the rest of this morning, 40-45 kt much of this afternoon, 40-50 kt
late this afternoon into this evening.
Late tonight, winds generally become more NE and decrease to near 20-
25 kt with gusts decreasing to near 30-35 kt.
Low level easterly jet moves in late this afternoon into this
evening with winds of 50-55 kt at 2kft for the coastal terminals.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments likely through the TAF period for changing cigs/vis and
possible fluctuations in flight categories.
Gusts may fluctuate between occasional and frequent before becoming
prevailing by 09Z-12Z today.
Thunderstorms too low confidence in timing and location to put in
TAFs.
OUTLOOK FOR 06Z THURSDAY THROUGH SUNDAY...
Late Tonight: IFR or lower in rain. The rain could be mixed with wet
snow at KSWF. Winds generally become more NE and decrease to near 15-
20 kt with gusts decreasing to near 25-35 kt. Peak gust to 40 kt
possible.
Thursday: MVFR or lower with lingering rain, possibly mixed with wet
snow at KSWF. NW gusts near 20 kt.
Friday: Mainly VFR. Slight chance of showers. NW flow with gusts
15-20kt.
Saturday: MVFR possible with northerly gusts near 20-25 kt.
Sunday: VFR with northerly gusts near 20 kt.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
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 mainly in the form of elevated ocean
seas persisting 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 2.5 inches of rainfall is expected this
morning through early Thursday with locally higher totals of
3-3.5 inches possible. The bulk of this rain will fall Wednesday
afternoon and evening. A period of higher rainfall rates will be
possible Wednesday evening and early night with most around
0.5"/hr. Higher rates of 0.75"/hr will be possible.The best
location for these higher rates will be in NE NJ, NYC metro and
LI. This is the same area that a Flood Watch has been issued
for. The 00Z HREF shows a 90% 10-km neighborhood probability of
at least 0.5"/hr with some areas of 20-40% of seeing 0.75"/hr.
SOme of the higher rates may be possible in isolated
thunderstorms and could be as high as 1"/hr. Poor drainage
flooding and urban low lying flooding is possible along with
minor river flooding across quick responding rivers. WPC has
upgraded NE NJ, the NYC metro and LI to a slight risk of
excessive rainfall.
&&
.TIDES/COASTAL FLOODING...
Local minor flooding benchmarks may be reached, or just touched,
late tonight/early Wednesday morning along the Long Island south
shore back bays.
Around 2.5-3 ft of surge is needed for minor coastal flood Wed
aft/eve and around 3.5-4 ft for moderate coastal flooding.
With easterly winds ramping 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 Long Island and
along the western 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 for the southern and eastern
bays of Long Island) late Wednesday night into early Thu
morning. The coverage and areas of greatest coastal flood
impact will be highly dependent on track of the low, and timing
of the wind shift 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 6-10 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 Long Island Sound, breaking waves of 3-7 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. A similar threat
exists for the twin forks, with breaking waves of 4-8 ft
Wednesday evening and Thursday morning.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...Wind Advisory from 11 AM this morning to 6 AM EDT Thursday for
CTZ005>008.
High Wind Warning from 11 AM this morning to 6 AM EDT Thursday
for CTZ009>012.
Coastal Flood Warning from 4 PM this afternoon to 10 AM EDT
Thursday for CTZ009-010.
Coastal Flood Watch from late tonight through Thursday morning
for CTZ011-012.
NY...Wind Advisory from 11 AM this morning to 6 AM EDT Thursday for
NYZ068>070.
High Wind Warning from 11 AM this morning to 6 AM EDT Thursday
for NYZ071>075-078>081-176>179.
Coastal Flood Warning from 4 PM this afternoon to 10 AM EDT
Thursday for NYZ071-073-078-176-177.
Flood Watch from 4 PM EDT this afternoon through late Thursday
night for NYZ072>075-078>081-176>179.
Coastal Flood Advisory from 2 PM this afternoon to 7 AM EDT
Thursday for NYZ072-074-075.
Coastal Flood Warning from 2 PM this afternoon to noon EDT
Thursday for NYZ079>081-179.
Coastal Flood Advisory from 2 PM this afternoon to 7 PM EDT
this evening for NYZ178.
Coastal Flood Warning from 3 AM to 7 AM EDT Thursday for
NYZ178.
NJ...Wind Advisory from 11 AM this morning to 6 AM EDT Thursday for
NJZ004-103>108.
High Wind Warning from 11 AM this morning to 6 AM EDT Thursday
for NJZ006.
Flood Watch from 4 PM EDT this afternoon through late Thursday
night for NJZ002-004-006-103>108.
Coastal Flood Advisory from 2 PM this afternoon to 7 AM EDT
Thursday for NJZ006-104-106-108.
MARINE...Storm Warning until 6 AM EDT Thursday for ANZ331-332-335-338-
340-345-350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...BR
NEAR TERM...BR
SHORT TERM...BR
LONG TERM...BG
AVIATION...JM
MARINE...BG/BR
HYDROLOGY...BG/BR
TIDES/COASTAL FLOODING...