269
FXUS61 KOKX 052146
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
446 PM EST Wed Feb 5 2025
.SYNOPSIS...
-- Changed Discussion --
High pressure over the area this evening will give way to low
pressure that impacts the area late tonight into Thursday. The
low`s cold front passes through the waters late Thursday night
into early Friday morning followed by high pressure building into
the region through Friday night. Another area of low pressure
impacts the area Saturday night into Sunday. High pressure builds
back in Sunday night and Monday. A series of low pressure systems
pass near the area Monday night through Wednesday.-- End Changed Discussion --
&&
.NEAR TERM /THROUGH THURSDAY/...
-- Changed Discussion --
High pressure across the area this evening moves offshore with
increasing mid and high level clouds. Aloft, a fast, nearly
zonal flow will send a disturbance out of the Mid Mississippi
Valley this evening east across the Ohio and Tennessee Valleys
overnight. As it approaches Thursday morning, a weak secondary
low will take shape south of LI, passing to the east in the
afternoon. Warm advection precipitation will break out across
the area from SW to NE, approximately 5 to 8 am. It will begin
as snow everywhere for about a 2 to 3 hour period, then
transition over to rain. Far interior locations, may not
changeover to plain rain until early afternoon, and by that time
it will be mainly pockets of light rain and/or drizzle. Models
vary with how quickly the warm air comes in aloft, with the 12Z
NAM particularly aggressive, while the GFS and HREF solutions
hold on to the colder air a bit longer. We are talking about a
matter of 1-2 hours difference, but with a fast system that can
be significant. So a slightly colder solution, and a 1 to 2 inch
snowfall event may end up closer 3 or 4 inches. However, taking
a middle road approach, somewhere between the colder and warmer
solutions seems prudent at this time. However, with a strong SW
flow aloft, the warmer NAM solution is not out of play. Thus,
staying with a 1 to 2 inch snowfall with the higher end across
CT, the Lower Hudson Valley and NE NJ. Coastal locations as is
typical with these SE flow events often see the boundary layer
warm to above freezing before before that happens aloft. Thus,
across LI and the NYC metro, expect any freezing rain to be real
brief. Ice accretion amounts across the interior are expected
to range from a few hundredths of an inch to as much as a tenth
well north and west of the NYC metro. All winter advisories
remain in effect with no changes in timing. Highs will top out
in the mid 30s to around 40.-- End Changed Discussion --
&&
.SHORT TERM /THURSDAY NIGHT/...
-- Changed Discussion --
Behind the departing offshore low Thursday night, a cold
frontal passage will follow late as low pressure passes to the
north across eastern Canada. Skies will also be clearing with
temperatures remaining on the warm side in the lower to mid
30s. In fact, most locations will not drop below freezing until
Friday night. Any refreezing will be limited across far
interior locations.-- End Changed Discussion --
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
The long term period remains active with the upper flow nearly zonal
and as a series of shortwaves and weak, low amplitude, trough move
through the flow. Guidance remains in good agreement with the system
for Saturday night into Sunday, and fairly similar to the previous
forecast, and probabilities have been increased to near 100%. With
cold air in place a wintry mix of snow, freezing rain, and rain is
expected. However, there is some uncertainty with the track of the
low, and trends have been slightly farther to the north. With a more
northern track plain rain will be possible across metropolitan New
York City and across Long Island. Temperatures are non diurnal
Saturday night as the low tracks near the region, and the system`s
warm front nears coastal Long Island. A longer period of freezing
rain will be possible inland, and possibly closer to the coast, if
the warm front remains farther to the south. A cold airmass moves in
with building high pressure, and temperatures will be several
degrees below normal. With the cold airmass in place, and a series
of waves of low pressure tracking along a stationary frontal
boundary to the south, will bring the potential for a prolonged
period of snow late Monday night into Wednesday. There is a lot of
uncertainty with the track of these lows which will impact how far
north precipitation will extend and whether or not a mix will be
possible along the coast. With this uncertainty have used the
deterministic NBM for temperatures and precipitation types Monday
night through Wednesday.-- End Changed Discussion --
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
-- Changed Discussion --
Low pressure approaches from the west late tonight and Thursday
morning and exits northeast Friday evening.
VFR through late tonight. Low pressure brings MVFR cigs and -SN
between 9-10Z Thursday. IFR cigs expected by 12Z. Snow
transition to sleet and/or freezing rain around 13Z to 15Z.
Freezing rain has been dropped from KJFK, KLGA and KISP TAFs,
but kept in all other TAFs. Transition to rain will begin at
at terminals around 15 to 17Z, but may stay freezing rain at
KSWF. Precip to end 18-20Z. LIFR is possible, at times.
Following the precip ending, lower IFR/LIFR ceilings may linger
through 00Z with possible fog developing.
Winds are mainly around N 5 kts, though some sites are light and
variable. Will either remain light and variable into tonight or
around 5-7 kts from the NE/E. Winds pick up 5-10 kts E/SE late
tonight ahead of an approaching low pressure. During the event winds
will be S 5-10 kt. Following the precip ending, winds shift WSW.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments may be possible for the timing of category changes
and onset of snow Thursday morning and for p-type timing
changes.
.OUTLOOK FOR 21Z THURSDAY THROUGH SUNDAY...
Thursday night: VFR w/ chance of IFR if fog develops.
Friday: VFR. W winds G20-25kt.
Saturday: Chance of snow with IFR cond in the afternoon. Snow
changing to a wintry mix expected at night.
Sunday: Precip should change over to all rain by daybreak Sunday
except for KSWF. MVFR to IFR at times. Becoming VFR as precip ends
during Sunday afternoon.
Monday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
-- Changed Discussion --
High pressure over the area this evening will move offshore as
a frontal system approaches from the west. SE winds strengthen
after midnight with the potential for winds briefly closing in
on 25 kt for a few hours. Wind then diminish as weak low
pressure form close to the waters and heads east in the
afternoon. West winds strengthen Thursday night with gusts
increasing to 20 to 25 kt. A building southerly swell brings 5
ft seas into the ocean waters east of Moriches Inlet Thursday
afternoon and across the remaining ocean zones at night. Thus, a
SCA has been issued for all oceans waters, beginning Thursday
afternoon on the eastern waters and then the remaining ocean
waters at night.
Strong west to northwest flow, in the wake of a cold front, is
expected Friday with SCA conditions on all waters. With high
pressure quickly building in late Friday into Friday night gusts
fall below advisory levels on all the waters Friday evening,
with ocean seas elevated into late Friday night. Sub SCA
conditions will be on all the waters toward Saturday morning and
through the day Saturday as high pressure builds overhead. With
another low pressure system quickly approaching Saturday night
small craft conditions become likely on the ocean waters with an
increasing southerly flow, and continue through Sunday as the
low moves through the region. Small craft gusts will be marginal
on the Long Island Sound late Sunday. Ocean seas remain
elevated at SCA levels into Sunday night, and subside below by
Monday morning in a diminishing northwest flow as high pressure
builds. Monday sub SCA conditions are expected across all the
forecast waters.-- End Changed Discussion --
&&
.HYDROLOGY...
There are no hydrologic concerns through the forecast period.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...Winter Weather Advisory from 4 AM to 1 PM EST Thursday for
CTZ005>012.
NY...Winter Weather Advisory from 4 AM to 1 PM EST Thursday for
NYZ067>071.
Winter Weather Advisory from 4 AM to 11 AM EST Thursday for
NYZ072>075-078-080-176>179.
NJ...Winter Weather Advisory from 4 AM to 1 PM EST Thursday for
NJZ002-004-103>105-107.
Winter Weather Advisory from 4 AM to 11 AM EST Thursday for
NJZ006-106-108.
MARINE...Small Craft Advisory from 1 PM Thursday to 6 AM EST Friday for
ANZ350.
Small Craft Advisory from 6 PM Thursday to 6 AM EST Friday for
ANZ353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...MET/DW
NEAR TERM...DW
SHORT TERM...DW
LONG TERM...MET
AVIATION...BR
MARINE...MET/DW
HYDROLOGY...MET/DW