377
FXUS61 KOKX 021841
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
141 PM EST Sun Feb 2 2025
.SYNOPSIS...
High pressure moves northeast of the region into the Gulf of
Maine today, then passes southeast of the Canadian Maritimes
tonight. Meanwhile, a frontal system approaches from the north
and west, with an associated warm front moving in tonight. The
front lifts north of the area on Monday, followed by a cold
front Monday night. High pressure returns Tuesday into early
Wednesday. A complex frontal system will approach on Wednesday
and impact the area from Wednesday afternoon into Thursday
night. High pressure will return on Friday, then another frontal
system should arrive by Saturday.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
A Winter Weather Advisory has been issued for interior southern
CT.
A warm front with the frontal system moves in tonight.
Precipitation is expected, mainly in the form of snow but some
slight warming in the low levels late tonight will allow for
more of a rain/snow mix along the coast. Otherwise, for the
interior, an all snow event is expected, where near 1 to 2
inches of snow is forecast across the Lower Hudson Valley and 2
to 4 inches across southern CT. Less than 1 inch of snow is
expected along the coast. Latest 12z guidance came in with an
upward trend in QPF and also continuing the very subtle trend in
a deeper shortwave. Also, there is decent agreement on a 1-3
hour window where lift is maximized in the DGZ based on model
soundings. QPF totals around 0.25 inches across southern CT
combined with 11-13:1 SLRs resulted in right around 3 inches of
expected snowfall. Vertical forcing with mid level positive
vorticity advection and low level omega increase for the first
half of tonight. Forcing wanes second half of tonight with low
pressure wave and front exiting the region. Precipitation
expected to end before sunrise Monday. As the forcing wanes the
mid levels dry out a bit and precip could potentially end as
some lingering freezing drizzle for the locations that are still
below freezing at the surface.
High pressure north of the region early today and associated
subsidence will allow for light winds. Then, flow becomes more
southerly later today and a frontal system approaches from the
north and west. Clouds will continue to increase during the day,
especially in the afternoon.-- End Changed Discussion --
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Precipitation shifts east of the region Monday morning and the
warm front will move farther northeast of the region. More low
level warm air advection on SW flow will make for warmer than
normal temperatures Monday. Went with NBM for the high
temperatures which leans more towards the cooler side of MOS
guidance due to the abundance of clouds expected for Monday.
Mainly dry conditions forecast Monday through Tuesday night.
A cold front moves across Monday night. Temperatures forecast
to be above normal through early Tuesday. Then temperatures
trend colder with cold air advection increasing Tuesday
afternoon into Tuesday night. Models indicate 850mb temperatures
falling down to near -10 to -12 degrees C during this
timeframe.
Warm front continues move farther away northeast from the local
area Monday. A cold front will eventually approach from the
north and west late Monday. This cold front moves across Monday
night. Less moisture associated with this frontal passage and
outside of perhaps a sprinkle or very light rain shower for
eastern parts of the region, dry conditions are expected to
prevail. Clouds will remain abundant.
For Tuesday, behind the cold front, a new high pressure area
will start to build in from the north and west. Dry conditions
are expected with temperatures still above normal as cold air
advection does not establish until Tuesday afternoon. Highs for
the day will likely be set in the morning with decreasing
temperatures in the afternoon. Gusty NW flow develops during the
day. Tuesday night lows will be relatively colder and below
normal. NW flow continues but will eventually become less gusty.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Fast zonal flow aloft with embedded shortwaves will impact the
area during mid to late week. NBM still running faster than
deterministic global model guidance with PoP daytime Wed, with
chance for some light snow in the afternoon mainly late. Then as
the sys approaches, expect light snow Wed evening to transition
to a wintry mix late Wed night, then to all rain across NYC
metro and Long Island early Thu morning, most of the area except
well inland by late morning, and throughout by afternoon. Light
accumulations of snow/sleet throughout, followed by some ice
accretion outside of the immediate NYC area but especially
inland, are possible.
Rain through the day on Thu should taper off Thu night as the
flow aloft amplifies and sends a cold front through late at
night, with dry cond for Fri into Fri night as post-frontal
strong high pressure moves across.
Another frontal system will approach this weekend, with timing
mainly from late say Sat into Sat night. Temps sfc/aloft appear
cold enough at the onset for mainly snow at least the first part
of Sat night, then a wintry mix may be possible for the NYC
metro area and Long Island late Sat night.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
A weak low passes thru the region tngt. A cold front approaches
from the W on Mon.
MVFR cigs will continue to roll in from the ocean this aftn. Aft
22Z, the next sys approaching from the W begins to impact the
area. Snow is expected to develop, mainly aft 00Z. A period of
moderate snow possible mainly aft 02Z, except possibly earlier
KSWF. Some mixing with rain at the coasts, with perhaps a
complete changeover to rain KJFK and KISP.
The pcpn ends generally aft 4-6Z, then MVFR or lower may linger
thru Mon mrng. Improvement to VFR aft 14-15Z Mon.
Winds mainly blw 10kt thru the TAF period.
Snow accumulations expected:
KSWF/KHPN: 2-3 inches.
KTEB: 1-2 inches.
KBDR/KGON: Around 2 inches.
KEWR/KLGA: Around 1/2 inch.
KJFK/ISP: Little/no accumulation.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Snowfall amounts could change based on the changeover to rain.
.OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
Rest of Monday: VFR.
Tuesday: VFR with NW flow 20-30kt.
Wednesday: VFR with light winds.
Thursday: MVFR or lower possible in rain or a wintry mix.
Friday: VFR with NW flow.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
Conditions should remain below small craft advisory thresholds
on all waters through Monday with a weakening pressure gradient
in place.
The next chance for SCA conditions will be Monday night and
Tue when a cold front passes through. These conditions may
linger into Tue night on the ocean. The non-ocean waters could
see some gusts up to 25 kt.
Longer term, minimal SCA cond (seas 5 ft and wind gusts 25 kt)
may be possible on the ern ocean waters from Thu afternoon into
daytime Fri with a passing frontal system.
&&
.HYDROLOGY...
There are no hydrologic concerns through the week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...Winter Weather Advisory from 6 PM this evening to 7 AM EST
Monday for CTZ005>008.
NY...None.
NJ...None.
MARINE...None.-- End Changed Discussion --
&&
$$
SYNOPSIS...BG/JM
NEAR TERM...JM/JT
SHORT TERM...JM
LONG TERM...BG
AVIATION...JMC
MARINE...BG/JM
HYDROLOGY...BG/JM