031
FXUS61 KOKX 200255
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
955 PM EST Sun Jan 19 2025

.SYNOPSIS...
Deepening low pressure off the Mid Atlantic coast will quickly
pass to the east of the area tonight and up into the Canadian
Maritimes by daybreak Monday. An arctic airmass will then build
in through mid week with high pressure building in from the west.
High pressure moves overhead Wednesday night into Thursday and
then offshore thereafter. A frontal system passes offshore Friday
before another high builds in from the west for next weekend.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Made some slight adjustments with POPs and weather for snow.
South Fork changing over to snow now. Heaviest of snow across
mainly Southern Connecticut New Haven to New London and Suffolk
County Long Island for late this evening. Snow mostly light to
the west but still continuing into late this evening.

For interior NE NJ, Lower Hudson Valley and interior SW CT,
thinking there is potential for some snowfall totals near 8
inches within this region. Lower end of snowfall range for
southern coasts of Long Island, mostly in the 3 to 4 inch
range.

The low will pass quickly to the east this evening and up into
the Canadian Maritimes by daybreak Monday.

Liquid equivalent amounts on average area expected to range
from 0.4 to 0.6" with some localized enhancements. Ratios will
vary quite a bit at the start with temperatures in 30s, but at
some point should get into the 15-10:1 range as temperatures
fall. Expect snowfall amounts of 3 to 5 inches along the coast
and 5 to 8 inches across the interior. Still no changes are
planned to the hazards at this time. The snow will become light
and end around midnight for NYC and points north and west and 3
to 4 am far eastern areas.

Temperatures will tumble into the upper teens to around 20 by
daybreak with N-NW winds gusting 20 to 25 mph, possibly up to
30 mph. Wind Chill values fall into the single digits overnight
and possibly as low as zero for the interior. These values fall
short of Cold Weather Advisory (-5F at the coast and -10F
inland).

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
Low pressure strengthens as it moves northeast into the Canadian
Maritimes with strong high pressure moving in from the west. This
tight pressure gradient will keep a gusty westerly flow, with cold
aid advection increasing.

Weather will be dry and very cold. Temperatures expected to be well
below normal.

Arctic airmass encompasses the area with NW winds ushering in colder
air. There will be strong cold air advection. Any leftover snowmelt
will refreeze and lead to slippery conditions for any untreated
surfaces. Temperatures forecast in single digits to lower teens
for morning with wind chills several degrees colder. Max temperatures
forecast only in the low to upper 20s. Went below MOS for the
high temperatures. With gusty westerly flow continuing, wind
chills will be at most, mainly within the lower teens on Monday.

For Monday night, the cold air advection continues. The westerly
gusty flow continues as well. Forecast lows are in the single digits
to lower teens for much of the area. The minimum wind chills are
mostly below zero with some locations near -5 to -10 degrees
towards early Tuesday morning.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Mainly dry and very cold to start Tuesday through Thursday, with
some moderation of the airmass Friday into next weekend.

Main upper jet remains south of the region Tuesday through Friday,
with then a return to more zonal flow.  Main trough in mid levels
remains over the Northeast Tuesday into Wednesday and then another
trough develops, moves in latter half of the week but more zonal for
next weekend.

Looks like the core of this arctic airmass will be across the local
region Tuesday through Wednesday. Strong high pressure will continue
to slowly build in from the west and move overhead Wednesday night
into Thursday. Gusty westerly flow Tuesday will subside Tuesday
night into Wednesday. Winds become nearly calm Wednesday night and
change direction to more SW.

The strong high pressure will still have its core to the west of the
region Tuesday night into Wednesday but a passing wave of low
pressure far offshore may result in brief snow to far southeast
parts of the region. Some models are indicating the far southeast
portions of the region on the northern fringe of the precipitation
from the low. Chances are low for any snow and expecting mainly
dry conditions to prevail.

Forecast highs are only in the teens Tuesday and get closer to 20
for Wednesday. Max wind chills Tuesday mostly in single digits and
then more in the teens for Wednesday. Lows Tuesday night mostly in
the single digits and then for Wednesday night interior is mostly in
single digits with coast mostly near 10. Minimum wind chills Tuesday
night below zero for most areas, and a greater fraction getting near
-5 to -10 degrees, locally near -15 degrees for isolated locations.

Low pressure system passes offshore Thursday night and then farther
out into the Atlantic Friday into next weekend. There could be some
snow across far southeastern sections of the region, just a slight
chance, with otherwise dry conditions continuing.

Across the local area, another high pressure area builds in from the
west for Friday into next weekend. Mainly dry weather conditions are
expected.

The airmass is forecast to moderate Thursday and thereafter into
next weekend. High temperatures forecast return to mostly mid to
upper 20s much of the area Thursday, but southeast sections lower
30s. Then forecast highs Friday lower 30s areawide and then rising
more within the 30s for next weekend.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
High pressure builds in as low pressure pushes east of the area
tonight.

MVFR to IFR conditions will improve through the rest of the
night as low pressure moves east, away from the area. High
pressure builds with gusty winds behind the low, generally
around 25 kt. Gusts may drop off briefly prior to and just after
daybreak, but are expected to return Monday.

Expected Snowfall Accumulations:

NYC terminals, BDR, ISP: 3-6" HPN: 4-8" SWF: 5-8"

 ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

Amendments likely for changing flight categories in snow.
Gusts of 25 to around 30 kt.

.OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY...

Monday night: VFR. NW winds diminishing with gusts up to 25 kt
early in the evening.

Tuesday: VFR. W wind gusts around 20 kt.

Wednesday: Chance of MVFR or lower in -SN, particularly coastal
terminals.

Thursday: VFR.

Friday: Mainly VFR, Chance of MVFR in light snow.

Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90

&&

.MARINE...
Deepening low pressure passes to the east of the waters this
evening and then up into the Canadian Maritimes by daybreak.
Arctic high pressure will begin to build in from west. This will
is a strong N/NW flow overnight with gusts on all waters
25-30kt on Monday.

SCA conditions continue on the ocean Monday night. Wind gusts
will be marginal for SCA for non-ocean marine zones Monday
night. Some lingering SCA conditions possible on the ocean
Tuesday with otherwise mainly sub-SCA conditions Tuesday onward
through Friday night. Some potential SCA conditions on the
ocean Tuesday night and Friday night.

Freezing spray potential for some of the waters Monday through
Monday night.

&&

.HYDROLOGY...
No hydrologic issues are anticipated through Saturday.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Winter Storm Warning until 4 AM EST Monday for CTZ005>008.
     Winter Weather Advisory until 4 AM EST Monday for CTZ009>012.
NY...Winter Storm Warning until 4 AM EST Monday for NYZ067>070.
     Winter Weather Advisory until 4 AM EST Monday for NYZ071>075-
     078>081-176>179.
NJ...Winter Storm Warning until 4 AM EST Monday for NJZ002-004-
     103>105-107.
     Winter Weather Advisory until 4 AM EST Monday for NJZ006-106-
     108.
MARINE...Small Craft Advisory until 6 PM EST Monday for ANZ331-332-335-
     338-340-345.
     Small Craft Advisory until 7 AM EST Tuesday for ANZ350-353-355.

&&

$$

SYNOPSIS...DW/JM
NEAR TERM...JM/DW
SHORT TERM...JM/DW
LONG TERM...JMC/JM
AVIATION...JP
MARINE...JM/DW
HYDROLOGY...JM/DW