000
FXUS61 KOKX 051140 CCA
AFDOKX
Area Forecast Discussion...CORRECTED
National Weather Service New York NY
640 AM EST Tue Dec 5 2023
.SYNOPSIS...
Weak high pressure builds in today, eventually dissipating as
low pressure develops well south and east of the area on
Wednesday. High pressure moves in Thursday and weakens Thursday night. This
high pressure area moves offshore Friday into Friday night. High
pressure offshore builds offshore Saturday. Offshore high pressure
area moves farther away farther out into Atlantic Saturday night. A
strong frontal system approaches from the west Sunday with an
associated cold front moving across Sunday night. High pressure
returns for early next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
Some minor adjustments were made to temperatures, dewpoints, and
cloud coverage to better match observed trends. Forecast overall
remains on track.
Low pressure associated with an upper-level shortwave pushes
offshore with weak ridging expected today in between as a
deepening trough approaches from the west. A surface high
pressure will build in along with the ridge. This should allow
for partly to mostly sunny skies today. Northwest winds will
gradually weaken throughout the day as the pressure gradient
weakens with high pressure building in. General northwesterly
flow with cold air advection also happening aloft will limit
afternoon highs to the low-40s.
A trough will deepen and track towards the eastern US tonight,
advecting mid-level moisture back in this evening, increasing
cloud cover. The deepening trough, which is centered more to
our south, with initiate cyclogenesis off of the North Carolina
coast. With a weak pressure gradient in place and strong cold
air advection (despite increased cloud cover) we should see cold
temperatures tonight. Interior areas below freezing in the
upper-20s with coastal areas at or near freezing. The only
exceptions are in the LI Pine Barrens which may dip into the
mid/upper-20s and the NYC metro in the mid-30s.
&&
.SHORT TERM /WEDNESDAY/...
A strengthening surface low will move into the open Atlantic
well to our south on Wednesday. The pressure gradient will
however increase north winds primarily for coastal areas where
wind gusts increasing to 20-25 mph late Wednesday into Wednesday
night. Several CAMs show a surface trough trying to kick up some
isolated precip along the northern fringes of the low pressure
system to our south. This could also be helped synoptically as
we will be situated in the left exit region of an approaching
jet streak oriented NW to SE to our northwest. Any precip that
does occur will be light and likely occur in the morning to
early afternoon. With high temperatures only in the low-40s to
upper-30s, both rain and snow showers will be possible depending
on what time the shower passes through. Regardless, precip
chances will be low and any that do do occur should remain
isolated. The best chances will be on eastern LI and in SE CT
since these areas will be closest to the surface trough`s axis.
BY late Wednesday afternoon, any remaining precip (if any)
should have cleared and moved south, with clouds beginning to
clear with dry air being advected in from the north.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Rain looking more likely for the latter half of the upcoming
weekend, with gusty winds, potentially up to near 40 mph.
Uncertainty stems from timing and pressure differences with the
frontal system for this so changes are likely with subsequent
forecasts.
Forecast relatively coldest day Thursday and warmest day Sunday. The
jet stream will still be positioned south of the region Wednesday
night and then more across the local region for Thursday night. The
jet levels overall exhibit a ridging pattern Thursday through the
first half of the weekend and then a strong southerly jet develops
Saturday night. The strong southerly jet approaches for Sunday. The
cold airmass over the area Wednesday night into Thursday will
gradually moderate and further exhibit increasing temperatures
on average with warm air advection this weekend. High temperatures
decline Monday back towards normal values for this time of year.
From large scale forecast models, the mid levels convey the trough
axis moving well out into the Atlantic Wednesday night. At the
surface, the pressure gradient will still be rather steep so gusty
NW flow can be expected along the coast Wednesday night. While most
of the gusts will be Wednesday evening in the 15 to 20 mph range,
locations along the coast could reach up to 25 mph for Wednesday
evening for gusts. There could even be some gusts up to near 20 mph
for these locations overnight.
There will be a steady ridging trend in the mid levels for Thursday
through Friday night. The ridge axis in the large scale forecast
models depict the mid level ridge axis right over the local area for
early Saturday.
The pressure gradient at the surface relaxes but does not totally
weaken Thursday into Thursday night. The pressure gradient weakens
more Friday into Friday night. While some gusts up to near 20 mph
can be expected, especially along the coast, for Thursday into
Thursday evening, no further gusts are expected thereafter through
Friday night.
For the first half of the weekend, large scale forecast models
convey a trough diving southward into Texas, with resulting upstream
ridging across the Eastern US. The ridge axis will be shifting east
of the local area. At the surface, high pressure will be offshore
Saturday and will move farther offshore Saturday night. Meanwhile, a
parent low approaching the Great Lakes is forecast to intensify.
For the latter half of the weekend, the large scale models show a
deep mid level trough approaching from the southwest. At the
surface, a frontal system approaches from the west with parent low
continuing to strengthen into the Great Lakes. The frontal system
and its associated cold front move across Sunday night, which
is shown later in ECMWF model compared with the Canadian model
with GFS exhibiting the most rapid speed of the front.
High pressure then returns for early next week as it builds in from
the west. Forecast models show mid level SW flow after trough exits.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
Surface high pressure slowly builds in overnight through Tuesday,
and remains Tuesday night.
VFR.
NW winds 10-15kt, at the metro terminals, and less than 10kt at
the outlying terminals overnight. Winds veer N late in the day
into Tuesday evening.
...NY Metro(KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Broken 4,000 ft bases late this afternoon or evening could drop to
MVFR, but is less likely so has been excluded from the TAFs for now.
OUTLOOK FOR 12Z WEDNESDAY THROUGH SATURDAY...
Wednesday: Mainly VFR, slight chance of MVFR with rain/snow showers
east of the New York City terminals in the morning. NNW gusts near
20kt afternoon into night, mainly coastal terminals.
Thursday-Saturday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Buoy 44097 increased with wave heights over last 1-2 hours. This in
combination with anticipated gusts near 25 kt over next few hours
along with near 5 ft seas in the ocean waters south of Montauk, put
up a short fused SCA until 10am this morning for the Moriches Inlet
to Montauk Point ocean zone. Otherwise, for other zones, any SCA
level gusts only expected to be occasional and mostly below SCA
thresholds. So for other marine zones outside of Moriches to
Montauk, overall below SCA conditions are expected.
Diminishing winds and waves later today and tonight means sub-
SCA conditions. Sub-SCA conditions will persist through
Wednesday afternoon.
Potential for SCA wind gusts on ocean Wednesday night with otherwise
sub-SCA conditions for Thursday through Saturday night.
&&
.HYDROLOGY...
No hydrologic impacts expected through this weekend.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 10 AM EST this morning for ANZ350.
&&
$$
SYNOPSIS...BR
NEAR TERM...JM/BR
SHORT TERM...BR
LONG TERM...JM
AVIATION...BR
MARINE...JM/BR
HYDROLOGY...JM/BR