000
FXUS61 KOKX 201732
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1232 PM EST Tue Feb 20 2024
.SYNOPSIS...
Canadian high pressure remains in control through Wednesday,
then weakens into Thursday. Low pressure approaches Thursday
night and passes through on Friday. High pressure follows for
the weekend, then a warm front passes through Sunday night,
which will be quickly followed by a weak cold front.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
The forecast is mainly on track this afternoon. The biggest
adjustment was to lower dewpoints a bit. The NBM 10th percentile
was blended in through the the early evening to capture the
current trend.
In the upper-levels, we start today with a long-wave trough and
polar jet situated to our north which will slide east of the
Canadian Maritimes tonight leaving us with weak upper-level
zonal flow on Wednesday. At the same time, a deepening shortwave
slides east across the SE US and offshore by midweek (with a
weak southern low shearing north towards the region).
At the surface, Canadian high pressure slides east across the NE US
on Tuesday and then slowly drifts east of the Canadian maritimes
Tuesday night thru Wednesday night, while nosing back SW across the
region. Meanwhile, an offshore low develops in response to the
shortwave over the Gulf Stream and slowly drifts NE (NW of Bermuda)
through mid week.
Dry conditions prevail thru the period with a continental polar
airmass Tuesday transitioning to a Canadian maritime airmass thru
midweek as the high shift northeast of us. Scattered cloud cover
appears likely to develop on Wednesday with onshore flow and nearby
low pressure offshore.
Temps will run several degrees below seasonable on Tuesday under the
southern periphery of the polar high with highs in the mid-30s.
Temperature will moderate closer towards seasonable on Wednesday
with maritime NE flow with highs near 40 degrees. Overnight Tuesday
temperatures under clear skies and light winds will drop into
the teens to 20s for most, near 30 for the NYC metro.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY/...
High pressure will gradually weaken Wednesday night and further lose
hold on Thursday as a frontal system approaches from the west. Cloud
cover will increase to broken then overcast west to east across the
area Thursday from the approaching system. Partly cloudy skies will
keep temperatures warmer Wednesday night with lows in the mid-20s
for most. Low-30s in the NYC metro. Highs on Wednesday will warm
into the low/mid-40s as warmer air surges in from southerly winds
ahead of the approaching frontal system. Things should stay dry
until Thursday evening/night.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A digging 500mb trough approaches from the west Thursday night. This
will help push a developing area of surface low pressure through the
forecast area during Friday. PoPs ramp up to likely late at night
into Friday morning with rain likely ending everywhere by the end of
the afternoon. Thermal profiles aloft are just cold enough to
support a mix of rain and snow should any precip fall before around
midnight across the northernmost zones. Temps aloft warm up
thereafter, and with a southerly flow, surface temps should remain
above freezing. High temperatures Friday 45-50.
Breezy for Friday night into Saturday as high pressure builds in
behind the departing storm which will be strengthening as it moves
through the Canadian maritimes. Colder, with highs on Saturday below
normal in the lower and middle 30s. The high pressure ridge shifts
through on Sunday with lighter winds and milder daytime temperatures.
A warm front approaches Sunday night. Moisture and lift with the
front may be just enough for some light precipitation, which would
be mainly rain with the exception of a wintry mix across the
northernmost zones during the evening hours before temperatures
aloft warm up behind the warm front. Kept PoPs at slight chance for
Sunday night. Weak high pressure keeps us dry on Monday with highs
above normal.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
-- Changed Discussion --
VFR with high pressure in control. There is a low potential of
high end MVFR from 12Z-18Z Wednesday, but confidence is not
high enough to include in TAFs at this time. Higher chances
along the coast.
NE winds becoming ENE after the morning push, then SE this
afternoon, remaining under 10kt. Winds throughout the day may
become light and variable at times at any terminal. Winds shift
toward the east tonight, still under 10 kt.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of wind shifts in the TAF may be off by 1-2 hours.
OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY...
Wednesday afternoon: VFR. Low chance for MVFR stratus near the
coast in the morning.
Wednesday night-Thursday: VFR.
Thursday night and Friday: MVFR or lower cond beginning mainly at
night, with rain becoming likely, possibly beginning as a wintry mix
at the onset at or near KSWF.
Friday night: VFR. NW winds G15-20kt.
Saturday: VFR. NW winds G20-25kt.
Sunday: VFR
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Sub-SCA conditions expected through Wednesday under influence
of high pressure. ESE ocean swells emanating from large offshore
low will build to SCA levels on the ocean waters Wednesday
Night and remaining into Thursday.
SCA conds continue on the ocean waters through Saturday night,
primarily due to swell, but gusts over 25kt are expected Friday
night into Saturday behind the passage of low pressure and a cold
front. This will bring advisory conditions to the non-ocean waters
as well during this period.
&&
.HYDROLOGY...
There are no hydrologic concerns through the beginning of next
week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JC/BR
NEAR TERM...BR/JT
SHORT TERM...BR
LONG TERM...JC
AVIATION...JP
MARINE...JC/BR
HYDROLOGY...JC/BR