Area Forecast Discussion Issued by NWS Upton, NY
000
FXUS61 KOKX 232350
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
750 PM EDT Mon May 23 2022
.SYNOPSIS...
High pressure over the area will slide offshore late Tuesday
into Tuesday night, and then remain offshore through the end of
the week. A slow moving low pressure system will affect the area
for the weekend.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Forecast is on track with only minor changes needed.
Surface high pressure, centered near the Great Lakes, continues
to build into the region as it slides east. Expecting to keep a
decent amount of cloud cover tonight with increasing mid-level
moisture as a shortwave passes nearby. CAMs try and introduce
light rain for a period overnight as the disturbance tracks just
to our south, though low-levels appear too dry to support much
reaching the ground. Given this and limited moisture
convergence, maintained a dry forecast overnight, though an
isolated, spotty sprinkle is possible.
After a sultry weekend, temperatures have returned to near
seasonable levels for late May, and this continues into
mid week. Forecast lows tonight will generally bottom out in
the 50s, to near 60 around the metro.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
The weak flow regime continues on Tuesday as the region remains
stuck between lower pressures over the Southeast, and the high
to our north. Winds veer easterly/southeasterly early in the day
as the center of surface high pressure slips off the coast of
New England and the Canadian Maritimes. With the onshore flow
and elevated mid- level moisture, expecting more clouds than
sun, which should inhibit temperatures during the day. 850 temps
fall from around 10C Monday, to 5-6C on Tuesday. Coupled with
the clouds, onshore flow, and cooler air aloft, expecting high
temps to top out a few degrees cooler than Monday, generally
around 70 for most. Dry conditions continue Tuesday night into
Wed AM, with lows falling into the 50s. Didn`t stray far from
NBM deterministic for this forecast.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Tranquil conditions expected through Wednesday night and
possibly into Thursday as the center of high pressure off the
New England coast slowly drifts east over the north Atlantic.
Aloft, zonal flow transitions to a building ridge. Despite the
building ridge an onshore flow thanks to a developing maritime
air mass during this time frame will keep temperatures at or a
few degrees below normal.
Some uncertainty exists for Thursday morning with a weak low or
inverted trough off the Mid Atlantic coast that may drift
northward Wednesday night into Thursday morning. Most
deterministic models have this feature in one form or another,
but whether this makes it into the area with some light
precipitation, or perhaps low stratus and drizzle (GFS forecast
soundings suggest a very dry layer at around 950-900 hPa) is
still unknown. Capped PoP at slight chance for Thursday due to
the uncertainty.
Thereafter, more significant uncertainty exists in the
deterministic models with the advance eastward of a cold front
from the Midwest on Thursday vs the potential for a low to cut
off over the Plains states along the frontal boundary as it
moves slowly toward the region into the weekend. The frontal
boundary will remain to the north and west during this scenario,
with prolonged onshore flow, cooler than normal temperatures,
and chances for precipitation from Friday through the weekend.
The ECMWF and GFS ensembles show a few members with weak areas
of low pressure at the surface that remain to the west into
Saturday night, lending credence to the cutoff. So, will lean
more towards the more pessimistic outcome for this time period,
but a total washout is not expected at this time. Given the
onshore flow, lowered temperatures a degree or two below NBM for
Friday and Saturday, which end up around normal for this time
of year.
The cutoff could still be plaguing the area Monday, situated to the
southeast over the Mid Atlantic region. However, there is still
a good deal of uncertainty this far out and stuck with NBM for
this time frame.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
VFR as high pressure builds to the north.
Winds should diminish this evening and settle in on a ENE to NE
bearing before midnight. Flow should become more easterly after
daybreak Tue, then SE closer to 10 kt in the afternoon.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
No unscheduled AMD expected.
.OUTLOOK FOR 00Z WEDNESDAY THROUGH SATURDAY...
.Tuesday night through Wednesday night...VFR.
.Thursday through Saturday...MVFR or lower possible at times in
any showers. A tstm also possible NW of the NYC metros on Thu.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
Winds and waves are expected to remain below SCA criteria
through Thursday night with a weak pressure gradient in place.
Waves build on a prolonged southerly flow over the ocean waters,
with 5 ft waves expected late Thursday night into Friday, which
could remain elevated into Saturday. Winds will remain below 25
kt through Thursday night. Gusts to around 25 kt are possible
on the ocean waters toward Friday afternoon given the approach
of a frontal system or low pressure from the west.
&&
.HYDROLOGY...
A frontal system will likely bring rain to the area late this week,
but there is too much uncertainty this far out in time in
determining any hydrological impacts, if any.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JP/DR
NEAR TERM...JP/DR
SHORT TERM...DR
LONG TERM...JP
AVIATION...BG
MARINE...JP/DR
HYDROLOGY...JP/DR