000
FXUS61 KOKX 181731
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1231 PM EST Thu Jan 18 2024
.SYNOPSIS...
High pressure centered to the south slides offshore this
afternoon. Low pressure develops along the Mid Atlantic coast
tonight and passes east of the area on Friday. High pressure
builds south of the region through the beginning of next week,
then over the Atlantic for the middle of the week.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Have been receiving some reports of some flurries or very light
snow across portions of NE NJ and the NYC metro. Not
anticipating anything more than flurries at this point given the
dry dew points and dry low levels but it would not be out of the
question a few locations pick up a very light coating.
Mostly cloudy to overcast conditions will continue through the
rest of the afternoon as a weak disturbance approaches. The
disturbance moves away from the area late afternoon, so any
lingering flurries should end before the evening.
High temperatures should reach the upper 20s inland and low 30s
near the coast.
Tonight, shortwave energy rounding the trough aloft swings east
and begins to spur cyclogenesis off the Carolina coast. It`s
possible a few flurries or light snow develops toward daybreak,
though with dry air to contend with, this may hold off until
later in the morning. Temperatures overnight fall back into the
20s.-- End Changed Discussion --
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
Surface low pressure spins up off the Mid-Atlantic into Friday,
passing south and east of the region through the day. Meanwhile
an upper level low embedded in a trough over the Great Lakes
begins to interact with the surface low. This likely creates an
inverted surface trough over much of the Mid-Atlantic which will
help bring in moisture from the offshore low pressure. Forcing
from the upper level jet will aid lift along the inverted trough
at the surface which should allow for a shield of light snow to
develop over much of the area by Friday morning.
By mid-morning, much of the area should be enveloped in a light
snow. This snow continues through the day as the surface low pushes
to the east. Unlike recent events, profiles support all snow
down to the coast, with surface temperatures in the 20s and
lower 30s, and sufficient deep layered cold air aloft. The exact
placement and intensity of the offshore low and associated
inverted trough over the area plays a crucial role in the amount
of snow that falls over the area. There may be a relatively
sharp north to south cutoff of precipitation as subsidence and
dry air north of the surface trough may limit snowfall.
Additionally, any banding within the inverted trough may
locally enhance snowfall during the afternoon on Friday. Light
snow continues into late day or early evening, and impacts are
expected for the PM commute with falling snow and reduced
visibilities.
QPF is expected to be light, generally under a quarter inch
total, and thus, accumulations should be light, with 2-3 inches
across the NYC metro and Long Island, and 1-2 inches for the
Lower Hudson Valley and Southern Connecticut. While a relatively
minor event, whether by snowfall or travel impacts to the
Friday evening commute, a Winter Weather Advisory may eventually
be needed for portions of the area. Given the marginal
snowfall, and that the event is still just over a day out from
beginning, opted to hold off any any headlines to allow the day
shift to reevaluate.
Conditions dry as the low pulls away Friday night, another
round of arctic air filters in from the northwest. Lows Friday
night and into Saturday morning will once again be in the teens
most places. Wind chills Saturday morning may once again be in
the single digits to near 0 for inland areas.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
A mid 1040s high centered near Omaha on Sat builds S of the area
thru Tue. It will be cold over the weekend with temps blw average.
NW winds will keep wind chills in the single digits and teens on
Sat, with wind chills dropping blw zero Sat ngt in the outlying
areas. Temps aloft warm a bit on Sun, so slightly warmer but highs
still likely aob freezing and wind chills in the teens and 20s. The
NBM was followed.
Heights rise Mon thru Wed with a further warming trend. By Tue,
projected highs are a degree or two abv normal. Some rain is
possible late Tue and Wed as GOMEX moisture begins to feed nwd into
the region. This setup could produce a wintry mix at times across
the interior, particularly Tue ngt. The NBM was followed.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
-- Changed Discussion --
High pressure will pass off to the south today. Low pressure
passes offshore Friday.
VFR through most of tonight. There is a chance of MVFR in snow
flurries only through about 19z today. Snow then develops in
the 10-14Z Friday time period, with IFR likely by around 14Z.
Snow is expected through the day on Friday.
WSW winds generally around 10kt with a few gusts up to the
lower 20kt possible this early afternoon. Winds will then go
light and variable for a time tonight before becoming NE less
that 10kt early Friday morning. Winds increase to around 10kt
during the day Friday.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
A few gusts up to the lower 20kt possible early afternoon along
with MVFR in light snow.
Amendments likely with flight category changes early Friday
morning.
OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY...
Friday Afternoon...MVFR to IFR with snow ending in the early
evening. Isolated NE-N wind gusts 20kt possible in the
afternoon and at night.
Saturday-Sunday...Mainly VFR. N-NW wind gusts 25-30 kt Saturday and
20-25 kt on Sunday.
Monday...VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
Monday...VFR.
Tuesday...VFR. Slight chance of rain/snow north and west of NYC
terminals.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
SCA is now only in effect for the ocean east of Moriches Inlet
through the afternoon. Sub SCA conditions are then expected on
all waters by this evening, persisting through Friday morning.
SCA conditions may redevelop Friday afternoon on the ocean with
gusts 25-30 kt.
A sca will most likely be needed on the ocean over the weekend, and
possible on the protected waters with mrgnl winds. A period sub-sca
cond late mon ngt into Tue, then winds and waves increase again late
Mon into Tue, before subsiding again by Tue ngt.
&&
.HYDROLOGY...
No hydrologic impacts are expected through the forecast period.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 4 PM EST this afternoon for ANZ350.
&&
$$
SYNOPSIS...JMC/DR
NEAR TERM...DR/DS
SHORT TERM...DR
LONG TERM...JMC
AVIATION...JT
MARINE...JMC/DR
HYDROLOGY...JMC/DR