000
FXUS61 KOKX 031744
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
144 PM EDT Wed May 3 2023
.SYNOPSIS...
Low pressure remains over the region before shifting offshore
late tonight into Thursday morning. A surface trough may linger
nearby on Thursday before high pressure starts to build in
Thursday night into Friday. The high pressure will then be
in control into the beginning of next week
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Plenty of cumulus across the region this afternoon, though
most have remained dry so far. Scattered showers that have
developed over much of Pennsylvania and Upstate NY should pivot
into the area this afternoon. A few rumbles of thunder and
small hail remain possible with any shower over the interior,
though haven`t yet seen this materialize elsewhere. Lesser
shower activity is expected over eastern Long Island and
southeast CT, and may even stay dry into the evening. Forecast
remains on track and previous discussion follows.
Anomalous closed upper low with 500 mb heights 2-3 standard
deviations below normal will continue to spin over the northeast
today. The center of the upper low begins to move towards the
coast this afternoon and evening. A broad surface low pressure
will linger over the area into this evening.
The greatest coverage from hi-res data looks to be around the
NYC metro/Hudson River corridor west into northeast New Jersey
and the Lower Hudson Valley. Shower coverage appears less
further east across Long Island and southeastern Connecticut due
to weaker lift and less middle level moisture. Steep low level
lapse rates along with the cold pocket aloft may yield a few
hundred J/Kg of SBCAPE, mainly north and west of the NYC metro.
Isolated thunderstorms are possible which may contain small
hail. Rainfall amounts will be light overall although some
isolated spots could see a few tenths in a heavier downpour.
Highs will only reach the middle and upper 50s, several degrees
below normal for this time of year.
The upper low and associated surface low move offshore tonight.
Showers are possible, especially along and near an inverted trough
that may set up NW of the offshore low. Overall coverage should be
isolated to scattered, especially overnight. Lows will be in the
lower to middle 40s.-- End Changed Discussion --
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
The low pressure system continues moving further offshore on
Thursday. However, cyclonic flow will remain aloft. Several
pieces of energy are likely to rotate around the upper low. A
surface trough should also be nearby. These features will
combine to keep mostly cloudy conditions in place with scattered
showers developing in the afternoon. Lapse rates are not as
steep and little to no CAPE is present in forecast soundings.
Highs will continue below normal in the middle to upper 50s.
Any lingering showers in the evening quickly diminish with loss
of daytime heating. Otherwise, high pressure begins to build in
from the north and west Thursday night. Mostly cloudy conditions
persist with lows in the 40s. High pressure continues building
in on Friday. The region will still lie on the outer periphery
of the upper low, which should be over the North Atlantic. There
will likely be enough middle level moisture to support mostly
cloudy skies. A shower is also possible in the afternoon as some
energy may persist on the backside of the offshore low. Highs
begin to moderate, but still should be below normal in the upper
50s to lower 60s.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
The area remains positioned between a departing midlevel trough
to the east and an amplifying midlevel ridge to the west by the
weekend. This pattern remains fairly steady with weak
disturbances embedded in the flow passing by through the long
term before the mid- level flow become more zonal by Tuesday to
Wednesday of next week.
At the surface, a weak surface high pressure builds into the
area over the weekend and persists through at least Monday.
This will result in fairly dry conditions with mostly clear to
partly cloudy skies during this timeframe. Temperatures will be
on a gradual warming trend with highs on Saturday in the mid-60s
gradually warming up to the mid 70s by Tuesday.
Pieces of energy continue to rotate around the backside of the
large wave trough to the east by the middle of next week which
may try to merge with other weak disturbances approaching the
area from the west. This may result in some weak low pressure
system impacting the area by late Tuesday or Wednesday of next
week.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Broad area of low pressure remains over the area through the TAF
period.
3-4kft cigs have moved into the NYC metro area. So we will be
on the border of MVFR and VFR for much of the day. In addition,
some scattered showers will be possible throughout the day.
Shower activity is expected to increase after 15Z with the most
numerous showers over the westernmost and NYC terminals. Showers
should begin to diminish into the evening but may linger
through 2-3Z . More widespread MVFR ceilings develop overnight
into Thursday morning.
WSW to SW winds at around 10 kt today. Winds veer to the NW and
N tonight and into the morning on Thursday at less than 10 kt.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments may be needed today with the terminals between VFR
and MVFR conditions. Uncertainty remains as to the extent of
shower coverage throughout the day, however, the western most
terminals (including NYC) should see the most of the activity.
OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY...
Thursday: Mainly VFR. Chance of showers with MVFR conditions at
times.
Friday: VFR. Chance of showers during the day. Light winds.
Saturday and Sunday: VFR. W/NW flow under 10 kt.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
-- Changed Discussion --
Conditions on the waters will be sub-SCA through tonight.
Winds on the eastern waters may increase Thursday and could reach
around 20 kt in the afternoon. Seas may also build close to 5 ft
east or Moriches Inlet from an offshore low pressure late Thursday
into Thursday night. Any elevated seas quickly subside Friday
morning with sub-SCA conditions elsewhere.
Sub-SCA conditions are expected on all waters Friday night through
the weekend.-- End Changed Discussion --
&&
.HYDROLOGY...
Residual minor flooding along the Passaic River at Little Falls
is forecast to continue into this afternoon before falling below
flood stage. Otherwise, no additional hydrologic impacts are
expected through early next week.
&&
.TIDES/COASTAL FLOODING...
Astronomical tides are increasing into the end of the week with
the approach of a full moon on Friday. The most vulnerable
locations along the south shore back bays, lower NY Harbor, and
Western Long Island Sound could see minor flooding benchmarks
touched with Thursday evenings high tide.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None.
NY...None.
NJ...None.
MARINE...None.-- End Changed Discussion --
&&
$$
SYNOPSIS...DS/MW
NEAR TERM...DR
SHORT TERM...DS
LONG TERM...MW
AVIATION...BC
MARINE...DS/MW
HYDROLOGY...DS/MW
TIDES/COASTAL FLOODING...