361
FXUS61 KOKX 061154
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
654 AM EST Mon Jan 6 2025
.SYNOPSIS...
Low pressure tracks through the Mid Atlantic today, passing to the
south and offshore tonight. High pressure then slowly builds in from
the west through Friday. An area of low pressure then passes to
our south this weekend.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Surface low centered near the KY/TN border this morning slides
east today, passing through the Mid Atlantic and offshore by this
evening. Ahead of it, WAA has allowed snow to break out in parts
of Pennsylvania and southern New Jersey, and this will attempt
to work into parts of the local Tri State through late morning.
The low is progged to pass well south of the area though, slipping
off the Delmarva or just south of it this evening.
The local area will lie on the northern periphery of this system and
its moisture field. Surface observations indicate the snow has
made it as far north and east as southeast PA and south central
NJ as of 1130Z, and should continue to creep closer through the
morning hours. This brings the light snow into northeast NJ and
NYC over the next several hours, likely between 9 am and 11 am,
then falling intermittently through the afternoon as it slides
east into Long Island, but struggles to gain additional latitude.
Forecast remains on track and previous discussion follows.
Latest hi res guidance continues to offer up to a tenth of an inch
of liquid on the high side for portions of the area, though the mean
around the NYC metro (where QPF is maximized) sits around five
hundredths, as does this forecast. Some interior locales likely
remain entirely dry from this event. Sounding profiles support SLRs
between 10 and 15 to 1. With this, a coating up to an inch still
looks reasonable for much of the NYC metro, western Long Island,
and NE NJ. Far southwestern portions of this area (Union NJ,
Staten Island, Brooklyn and southern Queens) look to have the
best chance at seeing an inch. Reasonable worst case in these
locales up to two inches. Farther north, little to no accumulation
is expected with perhaps just some passing flurries, or remaining
dry entirely, especially north and east of I-287 and into southern
CT. Given temperatures near or sub freezing through the event, snow
shouldn`t have an issue sticking on untreated surfaces where it
does fall if the intensity is there. Will monitor observational
trends this morning and may hoist a SPS to cover any possible
travel impacts in affected zones if warranted.
Any snow tapers by late afternoon or early evening, then dry
with increasing NW winds overnight as the low pulls away and
deepens. Temperatures fall back into the teens for most, and
the lower 20s around the NYC metro.-- End Changed Discussion --
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
Brisk and remaining cold through midweek.
As the low moves farther offshore Tuesday, surface high
pressure centered over the Plains begins to build east. This
will not only reinforce the cold air mass in place, but maintain
a tight pressure gradient between the high and sprawling low
pressure anchored over far eastern Canada. With it, a blustery NW
flow can be expected through midweek. Gusts on Tuesday look to
fall just shy of advisory criteria, as of now, with peak forecast
gusts generally in the 40 to 45 mph range. Similar conditions
can be expected on Wednesday, with dry conditions absent a stray
flurry or snow shower inland.
Temperatures, while not record breaking, will run about 10 degrees
below normal and keep most at or below the freezing mark through the
period. Add the wind component and the region likely see wind
chills persistently in the single digits and teens in this period.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
High pressure continues to slowly build in from the west on
Thursday, weakening as it finally shifts through the region Friday
into Friday night. Dry through his period with below normal
temperatures, although Friday`s highs will at least be warming
closer to normal levels. Gusty NW flow continues on Thursday with a
tight pressure gradient in place. Wind chills early Thursday morning
may range 5 above to 5 below zero.
Global models continue to show low pressure emerging off the east
coast to our south during Saturday and passing south of the 40N/70W
benchmark Saturday night into Sunday morning. The GFS is quickest
among the 00z models with the 500mb trough axis becoming negatively
tilted and thus farthest north with the storm center. Have nudged
PoPs downward a little from the previous forecast, but not as far
low as the 01z NBM as there`s still plenty of time to see if the
progressive/suppressed trend continues. The current forecast has dry
weather for Sunday with weak high pressure in place.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
Low pressure will pass to the south today.
VFR with lowering cigs this morning. IFR possible in steadier light
snow at the NYC terminals mostly from 16Z-19Z, otherwise mainly
MVFR during this period, improving back to VFR shortly thereafter.
Westerly to variable winds veer to NW-N with onset of light snow
and, then northerly much of the afternoon. Speeds generally 10kt or
less through the daytime hours. NNW flow increases with frequent
gusts after 01Z.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Winds potentially go light and variable at times or prevail mostly N-
NE from approx 14z-18z. Snow onset/end may be off by 1-2 hours.
Tempo MVFR cigs possible before 16z. Chance that IFR doesn`t occur.
Chance that snow doesn`t occur at KTEB and KLGA.
OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY...
Tuesday through Thursday: VFR. Gusts at or above 35kt at times.
Friday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Brief reprieve in conditions on all waters today, before winds ramp
back up again tonight. SCA conditions return to all waters
overnight into Tuesday as NW flow increases and gusts exceed 25
kt. Given the winds, cold air, and water temps, not out of the
question there could also be some light freezing spray, mainly
on the LI Sound and immediate nearshore ocean waters.
A Gale Watch remains in place for all waters Tuesday into Wednesday
due a strong pressure gradient and several shots of cold air moving
across the relatively warmer waters. Strong low pressure will reside
across the Canadian Maritimes during this period with high pressure
building in from the west. Gales likely linger into Thursday,
especially for the ocean waters, and may continue into Thursday
night.
&&
.HYDROLOGY...
No significant hydrologic issues anticipated through this weekend.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Gale Watch from Tuesday morning through Wednesday afternoon
for ANZ331-332-335-338-340-345-350-353-355.
&&
$$
SYNOPSIS...JC/DR
NEAR TERM...DR
SHORT TERM...DR
LONG TERM...JC
AVIATION...JC
MARINE...JC/DR
HYDROLOGY...JC/DR