270
FXUS61 KOKX 222026
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
326 PM EST Sun Dec 22 2024
.SYNOPSIS...
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High pressure will be in control through Monday. A weak
clipper system system approaches Monday night and moves through
on Tuesday. High pressure builds into the area Tuesday night and
remains in control through the end of the week. A frontal
system to the west slowly approaches next weekend.-- End Changed Discussion --
&&
.NEAR TERM /THROUGH MONDAY/...
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Arctic air mass remain over the Tri-State area tonight. The
associated high pressure will continue to settle overhead
through day break Monday. The pressure gradient will relax this
evening, but the boundary layer may take some time to
completely decouple across Long Island and southern Connecticut
since the center of the high pressure will be located across
eastern PA and upstate NY. Winds should drop off across these
locations after 06z as the center of the high moves overhead.
Ideal radiational cooling conditions will occur tonight, initially
west and then spread east towards early Monday morning. This will
allow temperatures to drop off significantly across the interior
where some locations could fall close to or just below zero. These
conditions should also yield lows close to 0 across the Long Island
Pine Barrens. Elsewhere, low temperatures will be in the single
digits to around 10 degrees. The NYC metro will stay a bit warmer
in the mid teens. Used a blend of MOS guidance with local
adjustments based on previous experience with similar patterns
across the area. The only record that could potentially be
approached or tied is at ISP where the previous record low is 8
set in 1989 (forecast low is 9 degrees).
High pressure remains in control on Monday. Temperatures will
begin to moderate with warm advection beginning to take place
in the lower levels. Ridging also builds overhead through the
day. Temperatures should reach the middle and upper 20s away
from the coast and low 30s near the coast and NYC metro. These
temperatures are still around 10 degrees below normal.-- End Changed Discussion --
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY/...
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A progressive mid level shortwave and associated weak clipper
system approach Monday night allowing high pressure to move
offshore. The clipper will then quickly pass across the region
late Monday night into Tuesday.
The bulk of the forcing will pass north of the area, but there
will be a band of light snow moving in from the west towards
day break Tuesday. Temperatures may fall the first half of
Monday night and then remain largely steady in the mid to upper
20s. Temperatures should then slowly rise early Tuesday morning
as the associated warm front lifts north of the area. Thermal
profiles are supportive of all light snow down to the coast
initially. The light snow will be short-lived at any given
location due to the narrow corridor of forcing. The guidance has
also been showing the light snow diminish in coverage as it
moves east of the NYC metro. If any precip lingers near the
coast by mid morning some rain could mix in with the snow. This
will not be a significant event and any snowfall accumulation
will be light and a few tenths, highest NW of the NYC metro.
The low pressure associated with the clipper system transfers to
the coast in the afternoon setting up a W-WNW flow, which will
bring improving conditions. Temperatures should also rebound to
seasonable levels in the upper 30s inland and low 40s near the
coast.-- End Changed Discussion --
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
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Upper level shortwave will continue to push east of New
England Tuesday night, with upper level riding over the eastern
Great Lakes moving toward the Northeast. At the same time,
surface high pressure continues building in, with the center of
high pressure over southern Quebec.
The center of the high meanders over southern Quebec through
the end of the week, slowly drifting northeast by the weekend.
This allows a frontal system to approach during the weekend, but
it`s expected to remain west of the area through the time
frame. Dry conditions are therefore expected through the end of
the week, with slight chance of precipitation by late Friday
night into Saturday. Chances for precipitation slowly increase
late Saturday through Sunday with the slow approach of the
frontal system.
A very slow warm up is expected through the week into the weekend.
Temperatures start out seasonably chilly, with highs in the 30s to
around 40 on Wednesday with highs a few degrees above normal by
Sunday (highs generally in the upper 30s to middle 40s).-- End Changed Discussion --
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
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High pressure builds across the terminals through Monday. A
frontal system approaches from the west late Monday, passing on
Christmas Eve (Tue).
VFR through the TAF period.
NW/NNW winds 10-15 kt for the next few hours. Gusts have now
gone occasional and will drop all together shortly. Winds drop
below 10 kts this evening. Light NW or VRB flow tonight into
tomorrow morning as high pressure centers overhead. Winds
gradually shift out of the S Monday afternoon with high clouds
increasing in the late afternoon/evening.
...NY Metro (KEWR/KLGA/KJFK/KTEB)TAF Uncertainty...
No amendments expected.
OUTLOOK FOR 21Z MONDAY THROUGH FRIDAY...
Monday night-Tuesday: Chance of MVFR in light snow/light rain mix,
mainly into Tuesday morning.
Wednesday-Friday: VFR.
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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The pressure gradient will weaken tonight as high pressure
builds over the waters. The high then remains in control into
Monday evening. A weak clipper system passes across the waters
late Monday night into Tuesday. High pressure then returns
through the end of the week. Winds and seas will remain below
SCA levels through the week.-- End Changed Discussion --
&&
.HYDROLOGY...
There are no hydrologic concerns through next weekend.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JP/DS
NEAR TERM...DS
SHORT TERM...DS
LONG TERM...JP
AVIATION...BR
MARINE...JP/DS
HYDROLOGY...JP/DS