000
FXUS61 KOKX 111206
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
706 AM EST Sun Feb 11 2024
.SYNOPSIS...
Weak high pressure builds in from the west through Monday morning,
then gives way to deepening low pressure approaching from the
southwest. A secondary low develops near the Delmarva Tuesday
morning and passes south and east of Long Island during the
day. High pressure returns Wednesday into Thursday before a
Clipper low passes through Thursday night into Friday. Another
low may impact the region over the weekend.
&&
.NEAR TERM /THROUGH TONIGHT/...
Some drier, cooler air starting to filter in on a light NW flow
behind a weak cold front. That being said, it is still around
20 degrees above normal at this hour.
Weak high pressure builds in from the west today following an
early morning cold frontal passage. Cold advection behind the
front is rather weak, and while somewhat cooler today, highs
will top out around 50. This is still about 10 degrees above
normal. High level clouds streaming out ahead of a deepening
upper trough out over the Southern Plains will keep it a mostly
cloudy day.
Some clearing tonight with a light NW-N flow will allow for a
cooler night, with lows ranging from the upper 20s inland and
across the Pine Barrens Region of LI, to the upper 30s across
the NYC metro.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
*Confidence remains medium to high across the interior for a
warning level snow event (>= 6 inches) late Monday night into
Tuesday. Winter Storm Watch remains up for interior portions of
NE NJ, the Lower Hudson Valley, and interior southern CT.
* A plowable, advisory level snow is possible for Southern
Westchester, coastal CT and portions of NE NJ west of the I-95
corridor.
* Uncertainty remains on the exact track of the deepening low
and timing of transition to snow in the NYC metro and Long
Island corridor.
Weak high pressure will be across the area to start on Monday
with even some sunshine before high level clouds arrive later
in the afternoon. It will still be mild with highs getting up
into the upper 40s.
Model guidance overall has changed little the last 24h as deepening
low pressure approaches from the SW late Monday, with secondary
low development near the Delmarva Tuesday morning. The low then
tracks to the south and east of LI during the day, passing near
the 40N...70W benchmark. There have been some slight northward
trends in the ECMWF and GFS guidance and without a damming high
in place to the north, much of the area will initially start
off as rain. Some of the colder guidance like the Canadian and
NAM keep coastal locations largely snow, but there is lower
confidence in these solutions. The easterly flow at the onset
will allow for some warmer maritime air to work in across the
area, especially coastal locations. The GFS has also been
persistent in showing a strong mid level warm nose that even
briefly pokes into some of the interior locations before going
over to all snow from NW to SE the second half of Monday night.
Coastal locations will be the last to turnover with NYC and Long
Island likely not happening until after daybreak. The changeover
looks to happen fairly quickly inland with the potential for 6
or more inches. Closer to the coast, the best chance for
advisory level snows will be coastal CT and portions of NE NJ
west of the I-95 corridor. For the NYC metro and Long Island,
the changeover looks to be late enough to only produce minor
accumulations of around an inch.
An important point of emphasis with this setup is that any
minor north-south adjustments in track will impact the amount
of snowfall across the region. Lower amounts can be expected
with a northward shift, and higher amounts at the coast with a
more southern track.
The precipitation will start after midnight from SW to NE,
becoming heaviest in the pre-dawn hours and continuing through
the morning, ending from west to east in the afternoon.
Northerly winds will gust between 25 and 35 mph on Tuesday,
with a few higher gusts to around 40 mph along the immediate
coastline. This combined with heavy snow could limit
visibilities to less than 1/2 mile. However, a limiting factor
for the blowing and drifting will be that this looks to be a
mainly wet snow. Temperatures across the interior will drop into
the lower 30 by daybreak Tuesday, and the mid to upper 30s
along the coast. So this is not a very cold airmass in place and
will limit how quickly the snow starts accumulating.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
High pressure builds into the region behind the departing low with
dry conditions through Thursday and temperatures slightly below
normal to normal for the remainder of the week and into the weekend.
A quick moving clipper system is expected to pass north of the
region Thursday night into Friday, which could result in some rain
or snow showers. Another low pressure system may impact the
region over the weekend. At this time, this second low appears
to have more precipitation with it than the Thursday
night/Friday event, however its a bit early to get into any
details on precip amounts and p- types.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
High pressure will builds into the region today and tonight.
VFR conditions expected through the TAF period.
A NW flow is expected today with wind speeds 10kt or less. There is
a chance that winds may shift more to the W for mid to late
afternoon, but confidence is low.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
No unscheduled amendments expected.
OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY...
Monday...VFR.
Monday night...IFR or lower conditions likely. At KSWF/KHPN,
rain or a snow/rain mix, changing to all snow after midnight.
Elsewhere, rain possibly mixing with snow late. NE winds 10-15
G20-25 kt late, highest NYC metro/coast.
Tuesday...IFR or lower cond likely. Precip changing to all snow by
late morning. Snow tapering off from W-E during the afternoon, with
cond possibly becoming VFR late. NE-N winds 15-20 G25-30kt, becoming
NW in the afternoon.
Tuesday night through Wednesday night...VFR. NW winds 10-15G20kt
daytime, and 10-15G20kt at night.
Thursday: Mainly VFR. W winds 10-15G20kt.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Swell/seas of 3 to 4 ft on the ocean slowly subside today with
light NW winds (less than 10 kt)as weak high pressure builds in
from the west. Tranquil conditions then continue into Monday.
NE winds increase Monday night ahead of an approaching deepening
low pressure system from the southwest. The low then passes
just south and east of the ocean waters on Tuesday. This will
allow winds to reach gales on the ocean on Tuesday. Thus, a
gale watch remains in effect for the ocean waters. Otherwise,
SCA conditions are likely for the remaining waters with even
occasional gale force gusts being possible.
Small crafts are likely to continue on the ocean waters into
Thursday with a tight pressure gradient over the area between the
departing low and approaching high pressure. Conditions eventually
fall below SCA levels late Thursday through Friday, however another
round of small crafts are possible over the weekend with another low
pressure system passing over or nearby the area waters.
&&
.HYDROLOGY...
There are no hydrologic issues expected at this time.
&&
.TIDES/COASTAL FLOODING...
Minor coastal flooding will be possible across multiple high cycles
through Monday night. A long-running statement remains in
effect for the western Sound as water levels with each high tide
may touch or barely surpass thresholds at Stamford and/or Bridgeport.
Advisories are in effect for the next two AM high cycles for S
Nassau.
Per blend of bias-corrected Stevens NYHOPS/ETSS/ESTOFS guidance, a
storm passing through Mon night-Tue has potential to produce
moderate flooding on the western Sound, the Long Island south shore
bays of SW Suffolk/Nassau, and lower NY Harbor, and minor flooding
elsewhere. Winds will be backing N around the time of high tide
which could keep levels from touching moderate benchmarks on the
Sound/Harbor. Have not yet issued coastal flood watches for this
time frame because of that, and also to avoid confusion with ongoing
earlier minor flooding.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Winter Storm Watch from late Monday night through Tuesday
afternoon for CTZ005>008.
NY...Winter Storm Watch from late Monday night through Tuesday
afternoon for NYZ067>070.
Coastal Flood Advisory until 11 AM EST this morning for NYZ179.
Coastal Flood Advisory from 8 AM to noon EST Monday for NYZ179.
NJ...Winter Storm Watch from late Monday night through Tuesday
afternoon for NJZ002-103.
MARINE...Gale Watch from Tuesday morning through Tuesday afternoon for
ANZ350-353-355.
&&
$$
SYNOPSIS...BC/DW
NEAR TERM...DW
SHORT TERM...DW
LONG TERM...BC
AVIATION...BC
MARINE...BC/DW
HYDROLOGY...BC/DW
TIDES/COASTAL FLOODING...