000
FXUS61 KOKX 221718
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
118 PM EDT Mon May 22 2023
.SYNOPSIS...
A backdoor cold front moves across the area this morning, then
stalls in the lower Hudson Valley to western Long Island before
dissipating this evening. High pressure will be in control
tonight through Tuesday night. A cold front moves through
Wednesday afternoon into Wednesday evening. High pressure
returns late week, potentially remaining in place through the
weekend as an area of low pressure meanders south of the region.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
Forecast generally on track. Just a minor adjustment to nudge
the POPs a bit closer to NYC, but over all, no significant
changes to the forecast.
A backdoor cold front remains in the vicinity of the NY/PA
border, and extends eastward across the Lower Hudson Valley into
LI Sound and across eastern Long Island. This front is not
expected to move much today. Soundings indicate developing
instability across the lower Hudson Valley this afternoon, along
with CAPE up to 200-400 J/kg, and weak lift. Inland cumulus are
expected to be widespread and a few will deepen to produce
light rain, and possibly thunder. Showers end early this evening
with the loss of heating and as the frontal boundary
dissipates.-- End Changed Discussion --
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
Once the stalled frontal boundary dissipates high pressure
centered across northern New England into eastern Canada will
remain across the region tonight through Tuesday night. A light
east flow around the high will keep temperatures below seasonal
normals tonight through Tuesday night.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Surface high pressure shifts offshore to start the period,
ahead of an approaching cold front currently progged to pass
through during the late afternoon and early evening hours on
Wednesday. The onshore flow will limit daytime heating along the
coast, where highs remain in the 60s. Inland, a mild SW flow
likely allows some areas to achieve the upper 70s.
With limited moisture, not anticipating a widespread rainfall
from the fropa, though a few scattered showers potentially make
it into the region as the front sinks south, with highest
chances of seeing across the interior. Also can`t rule out an
isolated thunderstorm, especially across the Lower Hudson Valley
where model soundings indicate some weak instability in the
late afternoon.
Conditions dry out Wednesday night behind the front, with a
1030 mb high building in from the northwest once again. Blustery
conditions may persist into Thursday with the tightened
pressure gradient, generally gusts up to 25 mph. Blended in the
NBM 90th percentile for winds late Wed night into Thursday due
to this possibility.
On the tail end of the departing trough, an H5 low cuts off and
meanders near or over the Southeast US into the holiday
weekend. Global guidance continues to vary with solutions run to
run, so nothing set in stone just yet with regard to
precipitation. Still, the trend with the 00z ensemble suite has
been drier for the local region, so capped PoPs at lower chance
(30%) much of the weekend. Temperatures will be near normal, if
not just below it, for much of the period, with highs in the 60s
and 70s.
Other than previously noted changes, national blended guidance was
followed for this update.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
-- Changed Discussion --
A backdoor cold front stalls nearby into the evening before
dissipating tonight. High pressure builds across the terminals late
tonight into Tuesday.
Conditions should remain VFR through the TAF period. There is a low
chance for MVFR ceilings early Tuesday morning. Confidence is not
high enough to include in the TAF at this time. There is also a
chance for isolated showers for Lower Hudson Valley terminals,
mainly KSWF, late afternoon and early evening.
NE winds become ESE-SE this afternoon 10-13 kt. Winds weaken this
evening into tonight and back to the E and NE. Outlying terminals
should go light and variable. An E-SE wind develops Tuesday morning,
becoming SE in the afternoon.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of wind shift to the ESE-SE may be off by 1-2 hours.
The afternoon KJFK, KLGA, KEWR haze potential forecast is
YELLOW...which implies slant range visibility 4-6SM outside of cloud.
Low chance of MVFR ceilings late tonight into early Tuesday morning.
OUTLOOK FOR 18Z TUESDAY THROUGH SATURDAY...
Tuesday PM: VFR
Wednesday: Mainly VFR. Chance of showers afternoon and evening.
N wind G15-20 kt at night.
Thursday-Friday: VFR. N wind G20-25 kt on Thursday.
Saturday: Chance of showers and MVFR. NE wind G15-20 kt possible.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Seas were up to a foot lower on the ocean waters than forecast
and adjusted downward early this morning. Seas will increase
with an increasing northeast flow mid to late morning as a
backdoor cold front moves into the waters and stalls across the
western waters this afternoon. Easterly winds may briefly gust
to near 25 kt on the ocean waters east of Moriches Inlet this
afternoon. Otherwise, high pressure will be in control and winds
and seas will remain below SCA levels across the forecast
waters through Tuesday night.
Increasing northerly flow behind a frontal passage Wednesday evening
may allow winds to gust up to 25 kt late Wednesday night through
Thursday morning, especially on the ocean. Ocean seas may hang near
5 ft through the day Thursday before subsiding below SCA criteria.
The pressure gradient and winds weaken by Thursday evening, with sub-
advisory conditions expected on all waters thereafter into the
weekend.
&&
.HYDROLOGY...
No hydrologic impacts expected through the weekend.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...DR/MET
NEAR TERM...BC/MET
SHORT TERM...MET
LONG TERM...DR
AVIATION...DS
MARINE...DR/MET
HYDROLOGY...DR/MET