000
FXUS61 KOKX 200012
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
712 PM EST Tue Dec 19 2023
.SYNOPSIS...
High pressure will be the dominate weather feature through the
upcoming weekend. The high departs east of the area Christmas
Day into Tuesday of next week. A frontal system begins to
approach from the west for next Tuesday.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
-- Changed Discussion --
Slightly increased low temperatures and increased clouds this
evening. Otherwise, no other significant changes made. The
forecast is on track.
The middle and upper level trough will continue moving offshore
this evening. The trough is expected to become a cut-off low
about 200 miles south and east of Montauk by Wednesday morning.
Ridging will begin to take shape over the northeast on the
backside of this upper low allowing high pressure to move closer
to the region. The core of the high will remain over the
Appalachians. Lingering low level moisture diminishes later this
evening leading to eventual mostly clear skies. NW winds will
weaken but not completely go calm tonight. Lows will be in the
middle 20s inland and upper 20s to low 30s near the coast and
within the NYC Metro area.-- End Changed Discussion --
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/...
The offshore upper low will be slow to push further east, but
high pressure will continue to ridge into the region. This will
support mainly clear skies and lighter winds. Temperatures will
be in the lower to middle 40s, near normal for this time of
year.
A shortwave traversing across southeast Canada will help give the
offshore upper low a boost to the east. The shortwave will also
leave behind some energy in the northwest flow with a weak cold
front passage occurring by early Thursday morning. The atmosphere
is dry and will only signify a reinforcing shot of cool and dry
air. The high pressure center that was over the Appalachians
weakens Wednesday night with a new stronger high taking over
from southeast Canada. Mostly clear skies are expected Wednesday
night through Thursday. Lows Wednesday night will be in the 20s
inland and low 30s near the coast. Highs on Thursday will be
slightly below normal in the lower 40s.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Looking at the consensus of large scale numerical weather prediction
models, 250mb height and winds depict strong westerly jet across
Mexico and into Gulf Coast Thursday night into early next week. The
models depict this subtropical jet to be relatively the strongest
for next Tuesday. The local region stays in between the subtropical
and polar jet. The 250mb height pattern does not get too amplified
across the local area.
Surveying the large scale numerical weather prediction models for
the mid levels, the local area has ridging Thursday through Friday
night. Then the mid levels depict a shortwave trough moving in
Saturday through Saturday night. Shortwave departs thereafter with
ridging resuming Sunday into early next week.
The consensus of large scale numerical weather prediction models
also conveys a dominance of surface high pressure Thursday night
through Friday night. This will be followed by a relative slight
weakness trend with the high pressure for the weekend. Then, high
pressure strengthens and builds back in for late Sunday into early
Monday. High pressure then departs to the east for Monday into
Tuesday of next week.
A frontal system will be approaching the area towards the end of the
forecast period, next Tuesday but timing is quite uncertain as is
the overall forecast for next Tuesday. Therefore forecast confidence
will be low for next Tuesday.
The weather during the long term forecast period will have dry
conditions Thursday night through the weekend and much of Christmas
Day. The deterministic GFS and Canadian models show some light
precipitation across parts of the region within the Saturday
afternoon through Saturday night. However, NBM does not show any
precipitation, not until a 90th percentile is selected for the 24hr
precipitation forecast. So, POPs are only near 10 percent at most
for precipitation for this rain and/or snow shower activity. This is
not enough POPs to show up in the forecast and keeping consistent
with surrounding offices also keeping POPs near or less than 10
percent as well as keeping consistent with the previously issued
forecast, kept this dry solution for the local forecast region. Only
expecting an increase in clouds with the shortwave passage and brief
weakness in the surface pressure field for the weekend.
Late Monday night is when any POPs appear in the forecast, a slight
chance for rain showers ahead of the next frontal system. The
chances for rain showers increase next Tuesday. The low level winds
are forecast to be more southwest Monday into Tuesday, allowing for
a warm enough airmass to keep the precipitation type rain.
Temperatures in the long term forecast trend from colder than normal
to warmer than normal. Departures from normal stay less than 10
degrees for much of the long term period but next Monday night and
next Tuesday, forecast temperatures could be pretty close to 10
degrees above normal values.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
High pressure remains in place through the TAF period.
VFR conditions prevail through the TAF period. Winds will be NW
around 10 kt much of the TAF period.
Some terminals will have NW winds more in the 10-15 kt initially
this evening before subsiding overnight. Some gusts to near 20
kt are forecast this evening.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Gusts near 20 kt possible at KJFK and KTEB at times this
evening.
Gusts to near 20 kt at KLGA and KEWR maybe more occasional this
evening.
OUTLOOK FOR 00Z THURSDAY THROUGH SUNDAY...
Wednesday through Sunday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
-- Changed Discussion --
Winds on the waters should largely remain below 25 kt through
Thursday. Some of the offshore ocean waters could see a gust just
below 25 kt Wednesday night into early Thursday due to an offshore
low pressure. Waves on the LI Sound east of the mouth of the CT
River will likely stay elevated around 5 ft tonight. The SCA
here remains in effect until 11Z Wednesday. The 5 ft seas for
LI Sound east of the mouth of the CT river are more uncertain
for Wednesday so SCA for this marine zone does not extend
farther out in time than 11Z Wednesday. Seas on the ocean will
also remain elevated through Wednesday night, and potentially
into Thursday. The SCA has been extended here through 11Z
Thursday for now and likely will need to be extended further in
subsequent forecasts.
Overall, the long term marine forecast period from Thursday night
through the weekend will feature high pressure prevailing, allowing
for a weak pressure gradient and mostly below SCA conditions except
as mentioned below.
The only SCA potential will be for ocean seas Thursday night through
Friday evening. The ocean seas are forecast to be around 5 to 7 ft
Thursday night, 5 to 6 ft Friday, and then 4 to 5 ft Friday evening,
before subsiding to 3 to 4 ft late Friday night. The ocean seas are
forecast to remain below 5 ft through the weekend.
Otherwise, aside from the ocean Thursday night through Friday
evening, and the entire long term marine forecast period for non-
ocean waters, below SCA conditions are forecast.-- End Changed Discussion --
&&
.HYDROLOGY...
-- Changed Discussion --
Residual river flooding will linger into tonight for the Ramapo
River at Mahwah and Quinebaug River at Jewett City. Both rivers
should fall below flood stage late tonight. There will also be
lingering moderate to major flooding along the Passaic River
(warnings handled by WFO PHI).
No additional hydrologic impacts are expected through the upcoming
weekend.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 AM EST Wednesday for ANZ332.
Small Craft Advisory until 6 AM EST Thursday for ANZ350-353-
355.
&&
$$
SYNOPSIS...JM/DS
NEAR TERM...JM/DS
SHORT TERM...DS
LONG TERM...JM
AVIATION...BR
MARINE...JM/DS
HYDROLOGY...JM/DS