000
FXUS61 KOKX 140032
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
732 PM EST Wed Dec 13 2023
.SYNOPSIS...
Strong high pressure will build in from the west through
tonight and remain in control through Friday. Another high from
southeast Canada will build in on Saturday, then move offshore
southeast of the Canadian Maritimes on Sunday. A developing
strong low developing to the south will begin to approach Sunday
night, then move nearby Monday and eventually to the northeast
Monday night. The low and associated frontal system may linger
nearby into Tuesday into Wednesday of next week.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
-- Changed Discussion --
The forecast is on track with only minor changes needed.
Previous discussion follows.
A sfc trough off to the NW fcst to move through late today or
early this evening before the strong sfc high to the west builds
in tonight. As this occurs winds should finally pick up out of
the NW, with gusts 20-25 mph into this evening especially in the
NYC metro area, in coastal sections and in the higher
elevations. A few lake effect streamers may make it down into
parts of the area tonight (SE CT this evening, and the lower
Hudson Valley and nearby parts of NJ/CT after midnight) and
have fcst only isolated PoP and brief mostly cloudy skies with
these. Otherwise mostly clear and dry for tonight, with low
temps ranging near 30 in NYC, to around 20 well NW of NYC and in
the Long Island pine barrens. Wind chills in the 20s this
evening should get as low as the lower 20s in/around NYC, to the
teens most elsewhere.-- End Changed Discussion --
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY/...
A mostly sunny day expected on Thu with temps near or just
below normal expected, with highs in the lower 40s per GFS MOS.
A gusty NW wind in the morning should start to back W in the
late afternoon and at night as the center of the high remains
inland from the OH valley to the Mid Atlantic region, and
weakens slightly as a sfc trough moves into New England.
Ridging aloft will be building across across Thu night into
Fri, which in combination with the sfc trough and downslope W
flow should lead to milder temps daytime Fri. After one more
cold night with lows from the lower/mid 30s invof NYC to the 20s
elsewhere, highs on Fri under mostly sunny skies should range
from 50-55, which is close to 10 degrees above normal in spots.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Main points here in the long term: First, a potentially
significant coastal storm appears near the local region for
Sunday night and into Monday of next week. There is potential
for gusty winds, heavy rain, as well as coastal flooding.
Second, there appears to be some chance of snow mixing in behind
this coastal low for late Monday night into Wednesday of next
week, mainly across the interior. It is difficult to narrow down
the lower and upper limits of the rainfall and wind gusts, but
overall there is potential for a few inches of rainfall and
gusts 35-50 mph.
Flattened mid level ridge moves in Friday night into Saturday,
and then moves offshore for the rest of the weekend. Multiple
shortwave troughs approach for Sunday and a large shortwave gets
amplified Sunday night through Monday as it approaches the
region. Models further phase together with northern and
approaching southern shortwaves with further amplification of
the approaching shortwave. From model consensus, it appears the
trough will take some time before its axis moves across the
local area, which appears to be more in the Tuesday timeframe.
The trough may not make much eastward progress going into the
middle of next week.
At the surface, high pressure builds in through the first half
of the upcoming weekend and then shifts out into the Atlantic
Sunday into Monday. Two areas of low pressure to the west will
be in play. One weak low pressure wave from the Tennessee Valley
will be moving east and interacting with a low developing
across the Southeast US. The low in the Southeast further
develops and approaches the region, moving northward Sunday
through Monday. It is uncertain how much northward progress this
low makes Monday but the models are coherent in showing that
this low gets closer and eventually directly over the local area
more towards Monday night. Then late Monday night into early
Tuesday, this low eventually moves northeast of the region. The
low and associated occluded front may linger nearby Tuesday and
even into midweek.
The uncertainty is growing in the Sunday through Tuesday
timeframe. Models in the mid and upper levels are depicting
multiple waves making for this more uncertain forecast coming up
for the latter half of the weekend and into early next week.
Deterministic runs of models showing variance between solutions
with different times of initialization making for differences in
terms of pressure, winds, and rainfall between each run. The
forecast used a blend of the previous forecast and national
blend of guidance for PoP and for winds used multiple blends of
guidance as well as the previous forecast. Due to the
uncertainty, do not have high enough confidence of impacts
regarding winds and flooding (less than 30% chance) to mention
in HWO.
Temperatures overall are forecast to be near normal Friday
night, and then above normal for the weekend and into Monday
with a trend closer to normal thereafter.
&&
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
A cold front quickly passes east as high pressure builds into
the region tonight.
VFR through the TAF period.
NW winds 5 to 15 kt this evening. Gusts to around 20 kt will
diminish through the evening, and may become occasional before
ending between 03Z-07Z. However, there is some uncertainty in
ending time of gusts and they may end a few hours before this
time frame. NW winds generally around 10 kt on Thursday and
shift more to the SW Thursday afternoon into the early evening
hours.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Ending time of gusts is uncertain, and therefore, some
amendments are possible.
OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY...
Thursday Night: VFR.
Sunday: MVFR possible with a chance of showers by mid or late
afternoon. Gusty E-SE winds possible along the coast.
Sunday night and Monday: MVFR or lower in rain. Gusty E-SE winds
possible along the coast. Winds may shift to SW or W Monday
afternoon.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Winds on the harbor and western Sound now look to come in under
25 kt, so have cancelled the SCA there. Farther east, SCA
continues into at least tonight, as winds shift NW and pick up
going into this evening, with gusts up to 30 kt on the ern
ocean waters and up to 25 kt elsewhere, while ocean seas peak at
5-6 ft.
SCA has also been extended for the ocean E of Fire Island Inlet,
where gusts up to 25 kt should linger into the early morning.
As winds back W to WSW Thu afternoon/evening, winds and seas
should increase late Thu night into daytime Fri especially E of
Fire Island Inlet, with gusts 25-30 kt and seas 5-6 ft. These
conds should subside by Fri evening.
Overall chances for SCA increase latter half of this weekend,
with chance for gales Monday and Monday night. The chances for
gales attm are less than 30 percent.
For Friday night through Saturday night, conditions are forecast
to remain below SCA thresholds on all area forecast waters.
Then, the ocean will increase with winds and waves Sunday, with
potential for SCA level conditions further increasing going into
Sunday night.
Non-ocean waters have below SCA conditions Sunday and Sunday
night forecast, but those waters too could get SCA level wind
gusts Sunday night. For Monday, all waters have potential for
SCA level wind gusts with SCA conditions becoming likely on the
ocean as the ocean seas forecast to continue to build,
potentially up to near 10 ft. For Monday night, forecast winds
further increase with gusts to gales on the ocean with non-ocean
waters forecast to stay with SCA level gusts.
&&
.HYDROLOGY...
A prolonged rainfall event is forecast Sunday through Monday
night. Bulk of forecast rain appears to be more focused in the
Sunday night through Monday timeframe, when rain could become
heavy at times. Flooding will be possible but still early to
determine exact extent and magnitude.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 AM EST Thursday for ANZ331-332-
340-355.
Small Craft Advisory until 10 AM EST Thursday for ANZ350-353.
&&
$$
SYNOPSIS...BG/JM
NEAR TERM...BG/JP
SHORT TERM...BG
LONG TERM...JM
AVIATION...JP
MARINE...BG/JM
HYDROLOGY...JM