782
FXUS61 KOKX 130010
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
710 PM EST Wed Feb 12 2025
.SYNOPSIS...
Low pressure and its associated frontal system impact the area
tonight into Thursday. High pressure then builds in Thursday
night through Friday before shifting offshore early Saturday.
Another storm system then impacts the area later Saturday into
Sunday. High pressure slowly builds back in early next week. Low
pressure may impact the area for the middle of next week.
&&
.NEAR TERM /THROUGH THURSDAY/...
-- Changed Discussion --
Winter Weather Advisory remains in effect for the interior from
7pm this evening through 9am Thursday morning.
High pressure over southeast Quebec will continue to ridge down
into New England into early this evening. At the same time, low
pressure developing over the southeast will begin moving toward
the Tennessee and Ohio Valleys. The associated warm front will
also begin to approach from the Middle Atlantic. Warm advection
north of the warm front will increase this evening which will
lead to precipitation development from southwest to northeast.
The timing of the precip has not changed too much from the
previous forecast. Model guidance has continued to trend warmer
leading to a decrease in snow/sleet accumulation for the first
half of tonight. Followed thermal profiles closer to the NAM as
the GFS can tend to run too cold in regimes with increasing
warming aloft. Another factor that has been weighed into this
forecast package and has led to the decrease in snow/sleet
amounts is limited saturation in the snow growth zone.
There is some lingering dry air noted in soundings with much
of the lift the first part of tonight falling below this zone.
Some snow development is possible at the onset this evening
areawide, but it may begin as a mix with sleet or even just be
sleet for a period of time. Near the coast the precip will
quickly change to rain as warmer air moves in both at the
surface and aloft. The snow/sleet combo may continue inland a
few hours longer before strengthening S-SW winds bring in a
warm nose from around 5-10kft, which effectively ends the snow
and yields a transition to liquid. The depth of the cold below
the warm nose is not deep enough to refreeze any of the melted
snow to sleet. Therefore, interior locations may see a period of
freezing rain overnight which supports the ongoing Advisory.
Most of the area should be plain rain by day break Thursday
except for some of the usual colder locations well inland.
Temperatures should rise for the rest of the morning as the warm
front lifts to the north. It may take longest for it clear the
interior, but expect temperatures there to reach the low 40s by
afternoon. Rain continues Thursday morning, but should taper off
quickly from west to east late morning into the afternoon. The
trailing cold front should quickly pass through late in the day.
Temperatures peak in the 40s before starting to fall by evening
with the cold front passage.
Little to no snow/sleet accumulation expected across NYC
metro and the coast with an inch or less inland. Generally a
glaze of ice accretion is expected in the Advisory area.
Areas of fog are also possible late tonight into Thursday as
the warmer air moves over the lingering snow pack.-- End Changed Discussion --
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
Dry and breezy conditions expected Thursday night into Friday
as high pressure slowly builds into the area. Temperatures
Thursday night should fall into the 20s. High temperatures on
Friday will be much cooler compared to Thursday with readings
below normal in the mid to upper 30s.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Another amplifying southern branch storm system will lift out of
the Mid Mississippi Valley Saturday, tracking to the north and
west of the forecast area Saturday night into Sunday. At the
same time, the polar vortex descends south and east out of central
Canada. Shortwave energy out ahead of it interacts with the
aforementioned low with explosive deepening Sunday into Sunday
night. There is some uncertainty with how quickly the cold air
to start on Saturday retreats to the northeast, but strong
thermal forcing will produce widespread precipitation across the
area beginning Saturday afternoon and night. This will likely
begin as snow everywhere with a changeover from south to north
starting at the coast late afternoon with most locations
becoming all rain around or shortly after midnight. There could
be a few pockets of surface temperatures around freezing well
north and west of the NYC metro until around daybreak. Thus,
looking at the potential for an advisory level event inland
with a combination of snow and ice. Coastal locations are
expected to see a quicker changeover with perhaps a light
snowfall accumulation during the afternoon hours Saturday.
For Sunday, the area gets into the warm sector as low pressure
passes to the north and west with a gusty southerly flow, especially
for coastal locations. There is even a low chance at this time
for an embedded thunderstorms just south of the area in warm
conveyor belt showers. This will be refined as we get closer to
the event. Highs on Sunday in the warm sector are forecast to
get will into the 40s and possibly the lower 50s across NYC and
LI. A strong cold front will then pass through late Sunday
afternoon and evening. There are some timing issues with the 12Z
operational runs with the GFS being the fastest. At this time,
saw no reason to defer from the NBM. More importantly, a piece
of arctic air associated with the polar vortex dropping across
the Great Lakes Sunday night into Monday will bring in a much
colder airmass for the first half of next week. This will be
accompanied by a gusty WNW flow Sunday night into Tuesday. Highs
will top out in the upper 20s to lower 30s with lows getting
into the teens for Tuesday and Wednesday mornings. Leaned a bit
colder than the NBM based on 2m temps in many of the operational
runs and the magnitude of the cold air coming down with 85h
temps over the area on Tuesday around -20C.
Cold high pressure builds in for Wednesday with some uncertainty
with the southern branch storm track. The GFS is aggressive in
taking low pressure up the east coast late Wednesday. This
hinges on the amount of energy left in the northern branch back
across the Great Lakes and the amount of phasing and/or interaction
between the two stream. However, it is much too early to have
any certainty at this point in time, but something to watch. For
the time, there are low chances for snow late Wednesday.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
A developing low along the southeastern coast approaches the region
tonight, and passes thru the area on Thursday.
VFR is possible at the start of the TAF period, with MVFR ceilings
expected to develop soon after. MVFR with a period of sleet and snow
early this evening, and transitioning to plain rain from south to
north 04Z through 08Z with IFR, possibly LIFR manly in fog with
lowered ceilings. At KSWF a period of freezing rain is possible
before going over to plain rain early Thursday morning. Timing of
the precipitation type changeover is uncertain and may be later than
forecast. Once precipitation ends conditions will fairly quickly
return to VFR late Thursday afternoon.
Less than 1 inch of snow/sleet accumulation expected north of New
York City, with little to none along the coast. A glaze of ice is
possible at KSWF.
NE/E flow flow tonight likely becomes L/V as the low tracks through
the terminals, then W/NW behind the low. Gusts to around 30 kt
expected late Thu.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments likely for changing flight categories thru the TAF
period. Timing of changeover to plain rain uncertain with amendments
likely.
Little to no snow/sleet accums expected this evening.
Peak gusts to around 30 kt possible late Thu.
.OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY...
Thursday night: VFR. W/NW gusts 25 to 30 kt, occasional gusts up to
35 kt along the coast.
Friday: VFR. NW wind gusts to 30 kt during the day.
Saturday - Sunday: Low pres could bring a wintry mix changing to
rain mainly late Sat into Sun. The rain could be locally hvy.
LLWS possible along with IFR.
Monday: VFR with gusty W flow.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
E flow continues to increase tonight leading to SCA conditions
on all waters. The flow on the non-ocean waters should decrease
below SCA levels Thursday morning, but continue to be strong
enough for 25 kt gusts on the ocean. Ocean seas will also remain
elevated during day Thursday. NW flow then increases Thursday
night leading to gales on the ocean and the likelihood of
another round of SCA conditions on the non-ocean waters. Have
issued a Gale Warning for Thursday night on the ocean. Since
there is currently an SCA for tonight on the non- ocean with a
lull in the strongest flow Thursday, have held off on any
advisory on the non-ocean for Thursday night at this time. Winds
should remain at SCA levels Friday, but should start weaken
through the afternoon. Seas will remain elevated.
Sub-SCA conditions may linger into early evening Friday for the
eastern ocean waters, otherwise high pressure builds in through
Saturday morning before giving way to another storm system
Saturday afternoon into Sunday. SCA conditions are forecast to
redevelop on the ocean waters late Saturday night and across
all waters Sunday in a strengthening southerly flow ahead of an
approaching cold front and deepening low pressure passing to the
northwest. Gales are possible on the ocean Sunday afternoon,
but temperature profiles may be too inverted to mix down gale
force winds to the surface. However, behind a strong cold frontal
passage late Sunday afternoon into evening, a westerly gale will
be possible across all waters Sunday night into Monday.
&&
.HYDROLOGY...
There are no hydrologic concerns through the period.
&&
.TIDES/COASTAL FLOODING...
With a recent full moon and increasing easterly to
southeasterly flow, this will allow for building waves and
increase the surge tonight into early Thursday. Result will be
higher total water levels across the coast. Surge models have
trended a few tenths of a foot higher than the previous day.
Minor coastal flooding is expected for much of the coastline
early Thursday as forecast surge reaches around 2 feet.
The total water level forecast for early Thursday reaches or
exceeds minor flood benchmarks for much of the coastline. The
total water level forecast took a blend of ETSS, ESTOFS, 50th
and 95th NY HOPS ensemble surge guidance. Wanted to go above the
average due to anticipated extra surge. Plus, previous high
tide cycle earlier today with respect to the NY HOPS surge
ensemble, ended up verifying more within the upper bounds of
that ensemble.
Have issued coastal flood advisories where total water level
forecast exceeds minor coastal flood benchmarks by at least a
few tenths of a foot. The total water level in some locations
within the advisory may approach close to respective moderate
coastal flood benchmarks such as within some parts of the South
Shore Bays but all coastline forecasts at this time for early
Thursday high tide are below moderate coastal flood benchmarks.
Have issued coastal flood statements where total water level
forecast approaches to just touches respective minor coastal
flood benchmarks.
Concerning erosion, just minor beach erosion expected with
some minor beach flooding but dune erosion is not expected. The
ocean waves are forecast to increase to 6 to 9 ft late tonight
into early Thursday but will not be breaking directly against
coast. The strongest winds tonight into early Thursday will be
more easterly and not as perpendicular to the shoreline. When
the winds become more southerly Thursday and more perpendicular
to the shoreline, they will be decreasing.
Winds further become westerly behind a cold front Thursday
afternoon, and that will really decrease the surge. Subsequent
high tide cycles are not expected to have any coastal flooding
for late Thursday through Friday night.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Winter Weather Advisory until 9 AM EST Thursday for CTZ005>008.
Coastal Flood Advisory from 9 AM to 2 PM EST Thursday for
CTZ009.
NY...Winter Weather Advisory until 9 AM EST Thursday for NYZ067>070.
Coastal Flood Advisory from 9 AM to 2 PM EST Thursday for
NYZ071.
Coastal Flood Advisory from 6 AM to 11 AM EST Thursday for
NYZ074-075.
Coastal Flood Advisory from 6 AM to noon EST Thursday for
NYZ178-179.
NJ...Winter Weather Advisory until 9 AM EST Thursday for NJZ002-103.
Coastal Flood Advisory from 6 AM to 11 AM EST Thursday for
NJZ006-106-108.
MARINE...Small Craft Advisory until 6 AM EST Thursday for ANZ331-332-
335-338-340-345.
Small Craft Advisory until 6 PM EST Thursday for ANZ350-353-
355.
Gale Warning from 6 PM Thursday to 6 AM EST Friday for ANZ350-
353-355.
&&
$$
SYNOPSIS...DS/DW
NEAR TERM...DS/DW
SHORT TERM...DS
LONG TERM...DW
AVIATION...MET
MARINE...DS/DW
HYDROLOGY...DS/DW
TIDES/COASTAL FLOODING...JM