024
FXUS61 KOKX 140032
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
732 PM EST Thu Feb 13 2025
.SYNOPSIS...
-- Changed Discussion --
Deepening low pressure will track across Canadian Maritimes
through Friday night, while high pressure gradually builds in from
the west. High pressure over the area Saturday morning quickly
gives way to a storm system approaching from the mid section of
the country. The associated warm front approaches Saturday into
Saturday night. Deepening low pressure will then track to the
north and west of the area Sunday, with a secondary coastal low
developing nearby. A strong cold frontal passage follows Sunday
afternoon into early evening. High pressure then slowly builds
back in early next week. Low pressure may impact the area mid
week.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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A secondary cold front will pass through eastern portions of
the forecast area within the hour. There could even be a few
sprinkles. A strong WNW flow and will persist through the night
as deepening low pressure lifts up into the Canadian Maritimes.
Gusts will generally be 25-30 kt overnight with a few higher
gusts possible.
The main limiting factor for gust magnitude is the overnight
timing and weak llvl lapse rates. As a result, the fcst keeps
winds just blw advy lvls, but the numbers have been increased
fairly substantially abv the model guidance - particularly the
NBM. The grids indicate an initial surge in the 00-04Z range,
then settling down slightly into the mrng. This initial surge is
where we could have some isold advy lvl gusts.
Otherwise, skies will clear this eve with dry air and subsidence.
Upstream stratus might hold together to produce some sct 3-4kft
clouds overnight, but downsloping should limit coverage.
With a well mixed bl, the NBM temps seems reasonable with local
adjustments.-- End Changed Discussion --
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
Windy and dry or Fri with deep subsidence and a dry airmass.
Increasing mid and high clouds in the aftn. With this setup,
increased winds abv the blended guidance. H85 in the NAM roughly
45kt, slightly less in the GFS. As a result, gusts to around 40 mph
seems reasonable attm.
Winds do decrease significantly Fri eve and ngt as a 1030s high
ridges across the region. Fairly thick mid and high clouds however
from the next sys approaching, so this should limit radiational
cooling potential.
Fro Fri and Fri ngt went close to the NBM for temps which produces
highs in the 30s and lows in the teens and 20s.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Another amplified southern branch storm system will impact the
area Saturday afternoon into Sunday. Low pressure over the Mid
Mississippi Valley will be preceded by strong thermal forcing
that moves into the area Saturday ahead of the associated warm
front. There has clearly been a colder trend in the guidance
over the last couple of days with probabilities increasing both
with the NBM and long range ensemble forecast system (EPS,
GEFS, and GEPS) for an advisory level snowfall event for CT,
the Lower Hudson Valley, and interior NE NJ. Even the 12Z GFS
and NAM show this potential across NYC and LI before a changeover
to all rain. However, confidence is lower for coastal locations
due to retreating and weakening high pressure and an onshore
southerly component. Typically, these ingredients don`t fair
well for a significant winter precipitation event. However,
these type of systems of late with decent thermal forcing have
provided accumulating snow before the elevated warm nose comes
in aloft. There is no doubt the precipitation will change over
to rain with a deep-layered strengthening W/SW flow ahead of the
amplifying southern branch upper trough. How quickly that
happens will be key to the amount of snow. In addition, there
now looks to the potential for significant icing across the
interior once the precipitation changes over rain. The surface
warm front is poised to stay south of the area through Saturday
night and arrives along the coast Sunday morning. However, it
now looks like the approaching upper forcing will result in the
quicker development of a secondary low along the coast Sunday in
close proximity to the area. While this will not inhibit the
warm air from arriving aloft, it will likely slow down the
erosion of the low-level cold air across some of the interior,
especially across northern portions of the Lower Hudson Valley
and northern portions of Fairfield and New Haven counties in SW
CT. These locations have the potential for a tenth of an inch or
more of ice accretion. The combination of snow and ice could
also necessitate a Winter Storm Watch within the next 24h for
some of these locations, and at the very least Winter Weather
Advisories.
As for temperatures, overnight lows Saturday morning will be in
the teens inland to the lower/mid 20s along the coast. Temperatures
will then be slow to rise and may not go above freezing until
late afternoon/early evening along the coast, and as late as
Sunday morning for the far interior. Temperatures on Sunday
then rise up into the upper 30s inland and upper 40s along the
coast.
Following a cold frontal passage Sunday afternoon and evening,
a much colder airmass arrives for next week. In fact, the NBM
has continued to trend down the last 24h and will continue to
go slightly colder at this time. A piece of arctic air associated
with a polar vortex drops across the Great Lakes Sunday night
into Monday. This will be accompanied by a gusty WNW flow Sunday
night into Tuesday. Highs will top out generally in the 20s with
lows in the single digits to teens beginning Tuesday morning,
Winds chill values will be as low as the single digits at night
and in the teens during the daytime.
Cold high pressure builds in for Wednesday with some uncertainty
with the southern branch storm track. Long term models differ
in the timing and track of low pressure passing to the south
late Wednesday into Thursday. There are low chances for snow
at this time.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
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High pressure builds into the region tonight through Friday.
VFR, except IFR at KGON until around 01Z, then VFR.
Gusty W/NW winds through tonight, with occasional peak gusts to
around 35 kt this evening. Sustained winds and gusts diminish
late tonight into Friday morning, then increase again to 25-30
kt after 14z. Then by late afternoon Friday winds and gusts
diminish, with gusts possibly ending by 00Z Saturday.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Peak gusts around 35 kt possible this evening.
.OUTLOOK FOR 00Z SATURDAY THROUGH TUESDAY...
Friday Night: VFR.
Saturday-Saturday Night: VFR early, the IFR in snow in the
afternoon. The snow should transition to rain along the coast in
the evening, and inland at night. A wintry mix may remain
inland through the night.
Sunday: IFR or lower. Rain with a chance of freezing rain inland in
the morning. LLWS possible. S Gusts 20-25 kt.
Monday: VFR with WNW wind gusts 30-35 kt.
Tuesday: VFR with WNW wind gusts 20-25 kt.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Fog decreases and winds increase this eve as low pres pulls away.
The dense fog advy has been canceled, and the gale wrng has been
expanded to all waters. Gales are expected thru Fri, with winds and
seas decreasing rapidly late Fri and Fri ngt.
High pressure on Saturday morning gives way to another storm
system Saturday afternoon into Sunday. SCA conditions are
forecast to redevelop on the ocean waters late Saturday night
and across all waters Sunday in a strengthening southerly flow
ahead of an approaching cold front and deepening low pressure
passing to the northwest. However, behind a strong cold frontal
passage late Sunday afternoon into evening, a westerly gale
will be possible across all waters Sunday night into Monday.
&&
.HYDROLOGY...
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While there are no significant hydrologic concerns at this time,
this will need to be watched over the next couple of days with
the potential for 1.25 to 1.75" of liquid equivalent Saturday
into Sunday morning. Some of this will fall in the form of snow
and ice before transitioning to all rain. The liquid equivalent
of the existing snowpack is about 0.25 to 0.75". However, this
is not all expected to rapidly melt and some of it will be
absorbed by the additional snowfall on Saturday. Gridded
flash flood guidance over a 6hr period is generally above 2
inches with the exception of NE NJ. Minor flooding of some of
the quicker responding rivers and streams is possible. WPC does
have the area under a marginal risk for excessive rainfall.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Gale Warning until 4 PM EST Friday for ANZ331-332-335-338-340-
345-350-353-355.
&&
$$
SYNOPSIS...JMC/DW
NEAR TERM...JMC/DW
SHORT TERM...JMC
LONG TERM...DW
AVIATION...MET
MARINE...JMC/DW
HYDROLOGY...JMC/DW