062
FXUS61 KOKX 152058
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
358 PM EST Sun Dec 15 2024
.SYNOPSIS...
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A weakening disturbance moves across the area tonight through Monday
followed by a quick moving frontal system Monday night into Tuesday
morning. Weak high pressure moves in briefly Tuesday night into early
Wednesday. Next frontal system moves in Wednesday afternoon into
Wednesday night. Its associated cold front moves east of the region
Thursday. High pressure returns Thursday night through Friday but
its center stays north of the region. Low pressure areas approach
from the Great Lakes and offshore in the Atlantic for next
weekend.-- End Changed Discussion --
&&
.NEAR TERM /THROUGH MONDAY/...
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Mid level shortwave with weak surface reflection approaches from the
west tonight and passes through on Monday. Associated precip becomes
likely towards midnight with the best overall chances overnight into
the first half of Monday morning. There will still be a good chance
of precip however during the afternoon in some areas - particularly
near the coast where low level warm advection will be greater.
A brief window of wet-bulbing due to erosion of lingering dry air
supports an onset of light snow across the interior of the Lower
Hudson Valley, interior NE NJ, and into interior CT. An elevated
warm nose will be pushing through at the same time with above-
freezing temps in this layer reaching the entire forecast area by
the end of the night. Since this warm layer is at a low altitude,
there will be very little time for anything falling to refreeze into
sleet. So while can`t rule out a little sleet, thinking is that the
precip types for this event will be rain, freezing rain and snow.
For the interior areas, after thermal profiles no longer support
snow or when mid levels dry out and preclude snow as a potential
precip type, 2-meter temperatures will be slowly rising, however
ground temps may take some time to respond given the recent stretch
of cold weather. This will extend the threat of freezing rain well
into Monday morning. Further south towards the NYC metro, Long
Island, and coastal CT, plain rain is expected.
No changes to the Winter Weather Advisory, but while precip may be
lighter farther east within the advisory area, it only takes trace
amounts of freezing rain to cause hazardous travel. Still not enough
confidence to extend the advisory farther east into Northern New
London as precip probably holds off till daybreak and looks to be
more spotty in nature. Will continue to mention the ice potential
here in the HWO specifically during the morning commute.
Snowfall amounts are light - under 3 inches, and ice accumulations
anywhere from a light glaze to several hundredths of an inch.-- End Changed Discussion --
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY/...
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The next system will be quick to follow the departing shortwave. A
cold front associated low pressure tracking east through Canada
approaches Monday night and passes through during Tuesday morning.
Thermal profiles will be warm enough everywhere for rain. The rain
associated with the front will overspread the area Monday night and
quickly sweep off to the east Tuesday morning. Rainfall amounts are
around one quarter inch since the system is progressive and the
majority of the more organized forcing passes to the NW. Becoming
mostly sunny Tuesday afternoon. With west winds and 900mb temps
progged at 4-5C in the afternoon, went a couple degrees above NBM
for high temperatures. Highs around 60 for NE NJ, NYC and much of
LI, and upper 50s for most other areas.-- End Changed Discussion --
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
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An active pattern in place towards mid and through late week. Taking
a look at 250mb, strong upper jet streak north of the region Tuesday
night into Wednesday. This moves across the local area Wednesday
night into Thursday. Then, jet streak dives farther south Friday
into next weekend, setting up south of the region.
At 500mb, the upper pattern transitions from zonal Tuesday night to
a trough Wednesday night into Thursday. Then, briefly quasi-zonal
Thursday night before a longer wavelength trough sets up in the
region Friday into next weekend.
Surface pressure gradient not that tight Tuesday night through
Friday night. The pressure gradient tightens next weekend with
offshore developing low pressure and strengthening high pressure
moving in from the west. There is possibility for low and high
pressure to strengthen more than forecast for next weekend.
Regarding temperatures, overall decreasing trend. Colder airmass for
next weekend.
Regarding precipitation, mainly a rain event for Wednesday into
early Thursday. Potential for more snow Friday into the weekend.
However, models not really showing any significant phasing or
strength of low pressure. Might be more occasional snow shower
activity for Friday into next weekend.-- End Changed Discussion --
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
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Strong high pressure remains off the New England Coast tonight as a
disturbance approaches. A warm front slowly approaches from the
south Monday.
Ceilings lower toward 3 kft this evening, and MVFR ceilings become
likely towards 00Z. Ceilings continue to lower through the night
with IFR likely by 12Z Monday. Brief periods of LIFR are possible
from early to mid Monday morning. Visibilities during the time frame
will generally be MVFR for the city terminals, with brief periods of
2 SM or lower at times. Outlying terminals will see low end IFR,
with brief periods of LIFR at times.
Light snow develops at KSWF 03-05Z, expanding eastward as light rain
into city terminals around 05-07Z. The light snow at KSWF will
change to light freezing rain after 12Z before changing to plain
rain around noon.
Several hundredths of an inch of ice along with snow under 1 inch
expected at KSWF.
ENE-ESE flow is expected through the TAF period. Speeds will remain
under 10 kt, but may at times be around 10 kt.
...NY Metro (KEWR/KLGA/KJFK/KTEB)TAF Uncertainty...
MVFR timing may be off by 1-3 hours. Timing of IFR Monday morning
may be off by 1-3 hours.
OUTLOOK FOR 18Z SUNDAY THROUGH THURSDAY...
Monday Afternoon: IFR with rain likely.
Monday Night-Tuesday: IFR and rain. The rain ends in the morning
afternoon with conditions returning to VFR. S-SW gusts 15-20 kt late
Monday night into Tuesday morning, becoming W Tues afternoon.
Wednesday-Wednesday night: VFR early becoming MVFR-IFR with rain by
evening into the night. NW gusts 15-20 kt possible late Wednesday
night.
Thursday: Mainly VFR. NW gusts 15-25kt.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
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Conditions will remain below SCA levels on the waters through
Monday. Advisory level winds and seas look likely on the ocean as
early as late in the day Monday, and lasting through Tuesday as the
next frontal system moves across the waters. As for the other
waters, gusts of around 25kt gusts anticipated late Monday night
into Tuesday morning. SCAs have been issued accordingly.
Outside of the ocean, below SCA conditions are forecast Tuesday
night through Friday night. Wind gusts forecast stay below SCA
levels for the same time period. However, there will be chances for
SCA level wind gusts for all waters Thursday into Thursday
evening behind a cold front, with cold air advection.
The ocean is forecast to have lingering SCA level seas Tuesday night
as well as Wednesday night through Thursday. In addition, some
eastern portions of the ocean could have SCA seas Thursday night.
Sub-SCA forecast for ocean on Friday. Some eastern portions of the
ocean could again have SCA seas Friday night.-- End Changed Discussion --
&&
.HYDROLOGY...
There are no hydrologic concerns through next weekend.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...Winter Weather Advisory from 1 AM to 11 AM EST Monday for
CTZ005>007.
NY...Winter Weather Advisory from 10 PM this evening to 11 AM EST
Monday for NYZ067>070.
NJ...Winter Weather Advisory from 10 PM this evening to 11 AM EST
Monday for NJZ002.
MARINE...Small Craft Advisory from midnight Monday night to noon EST
Tuesday for ANZ331-332-335-340-345.
Small Craft Advisory from midnight Monday night to 6 AM EST
Tuesday for ANZ338.
Small Craft Advisory from 4 PM Monday to 6 PM EST Tuesday for
ANZ350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...JC/JM
NEAR TERM...JC
SHORT TERM...JC
LONG TERM...JM
AVIATION...JP
MARINE...JC/JM
HYDROLOGY...JC/JM