675
FXUS61 KOKX 161744
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1244 PM EST Thu Jan 16 2025
.SYNOPSIS...
A weakening frontal system approaches from the west today and
passes through the area tonight. High pressure will then briefly
return for Friday. Another frontal system passes through on
Saturday. Thereafter, frontal waves move by the area Sunday into
the beginning of next week. A strong arctic high pressure
system builds into the area through the middle of next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Forecast on track into the afternoon.
An upper trough swings across the area this evening. Ahead of
the trough is an area of light snow and flurries that has been
approaching. The air over the area is dry and have only seen
some flurries observed so far across portions of the interior.
The chance for snow showers and/or flurries increase into the
afternoon and evening. There appears to be a better alignment
with forcing and an increase in moisture across central and
eastern Long Island this evening. The CAMs continue to hint at a
a slight increase in coverage of light snow here.
Liquid equivalent amounts for this event are forecast to be
light with mainly a couple of hundredths of an inch or less,
except a bit more possible across central and eastern LI. Most
spots will just see a tenth or two of snow, but there is a
chance for a little bit more across central/eastern Long Island,
with as much as an inch across the twin forks of LI.
Daytime highs will be in the upper 20s inland to the lower 30s
at the coast, whatever does fall should accumulate. Any
lingering snow shower activity will then come to an end towards
midnight. Lows by daybreak Friday will be mainly in the 20s
with a few upper teens inland.-- End Changed Discussion --
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
For Friday, a ridge of high pressure aloft and at the surface
moves across the area. It will be warmer with highs in the upper
30s to around 40 with a light westerly flow. This will be
short-lived with a fast upper flow in the northern branch of
the polar jet. The next amplifying trough over central Canada
and the northern plains will race east, sending a frontal system
toward the area on Saturday with the associated cold front
passing through at night. Rain showers will break out across the
area Saturday afternoon. There is a possibility that snow could
briefly mix in at the onset across the higher elevations well
north and west of the area. No accumulation is expected with
temperatures getting into the 40s. Southerly winds in the afternoon
may gust 20 to 25 mph, highest along the coast. Rainfall amounts
of a 0.25" or less are expected with the highest across far
eastern LI and SE CT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
The cold front pushes through the area Saturday night with a weak
central low pressure wave developing along the front, off the Mid-
Atlantic coast. The center of this low looks to pass south and east
of the area into Sunday morning with mainly dry condition expected
through the first half of the day. By Sunday afternoon, a secondary
low pressure system develops downstream of a mid-level shortwave
swinging around the base of the trough which is positioned over the
Great Lakes. Guidance has come into better agreement that this low
pressure system looks to remain fairly weak and once again pass
south and east of the area through Sunday night into early Monday.
The ECMWF and GFS have portions of the area being impacted by the
northern edge of the precipitation shield with the potential for
some light snow, mainly for the coastal areas. The CMC has
consistently showed a stronger low that approaches the coastline,
resulting in more widespread precipitation with rain along the coast
and a mix of rain and snow inland. Opted to keep PoPs at a high end
chance (40-50 percent) with a chance of rain and snow showers for
much of the coast to account for the uncertainty.
The low moves northeast of the area by the afternoon on Monday with
a strong arctic high pressure system building into the center of the
US. This high pressure will gradually build eastward through the
middle of the week but will make for gusty NW flow with a relatively
tight pressure gradient over the area. Persistent CAA is expected
through the week with winds 10-20 mph and gusts upwards of 25-30
mph. This CAA and high pressure will allow for temperatures to drop
dramatically into midweek. High temperatures Monday will be only in
the middle to upper 20s. Highs by Tuesday will be in the teens with
the coast possible approaching 20 degrees. Lows will be in the
single digits Monday and Tuesday night with temperatures slowly
moderating later in the week.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
-- Changed Discussion --
A frontal system approaches from the west and moves offshore
tonight, passing south and east late tonight. High pressure
builds back in for Friday.
Generally VFR, with MVFR likely in snow showers late afternoon
into this evening. With chance probabilities have maintained the
PROB30. There is a low chance of brief IFR conditions with the
snow from the NYC terminals and west. Little to no accumulation
expected, one to two tenths of an inch. Light snow and lowered
conditions may be an hour earlier than forecast. Also, better
chances of IFR will be at KISP and KGON this evening as low
pressure develops south of Long Island.
Winds SW 10-14 kt this afternoon, may occasionally gust to near
20 kt at the coast. Winds become westerly later this evening,
and then NW around 10 kt after the snow ends.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Snow showers may begin an hour earlier than forecast. Amendments
possibly if conditions lower to IFR 00Z to 03Z. Occasional
gusts this afternoon near 20 kt, mainly at KJFK.
.OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY...
Friday afternoon: VFR.
Saturday: MVFR or lower at times with rain likely, possible snow at
night. S wind gusts around 20 kt during the day.
Sunday: Chance for MVFR or lower at times with increasing chances of
snow, with rain/snow mix for coastal terminals late day into the
evening.
Monday: Mainly VFR. Possible snow early morning with MVFR or
lower possible. NW wind gusts near 20 kt.
Tuesday:VFR. W wind gusts around 20 kt.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Sub-SCA conditions are forecast across the waters through
Friday night before a frontal system approaches on Saturday.
Southerly winds ahead of the associated cold front will likely
bring SCA conditions to the ocean waters with seas building to
4 to 6 ft and wind gusts up to 30 kt.
Seas around 5 ft may linger into Saturday evening, but sub-SCA
conditions are expected shortly thereafter on all waters Saturday
night. Waves then build on the ocean Sunday afternoon bringing
SCA through at least Monday night. For the non-ocean zones, wind
gusts near 20 kt should result in generally sub-SCA conditions
during this timeframe, but stray gusts to near or over 25kt
can`t be entirely ruled out.
Persistent winds above 15 kt with a frigid airmass in place may
result in the potential for freezing spray, especially on the ocean
where wave heights will be more elevated, as early as Sunday night
and continuing into the day on Monday.
&&
.HYDROLOGY...
No hydrologic impacts are expected into the middle of next
week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...DW/MW
NEAR TERM...DS/DW
SHORT TERM...DW
LONG TERM...MW
AVIATION...MET
MARINE...DW/MW
HYDROLOGY...DW/MW