000
FXUS61 KOKX 280300
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1000 PM EST Sat Jan 27 2024
.SYNOPSIS...
Weak high pressure over the area will retreat to the northeast
tonight as low pressure approaches from the Tennessee Valley.
This low will weaken west of the Appalachians Sunday morning
while a new low forms along the Mid Atlantic coast and then
passes south and east of Long Island Sunday afternoon and
night, and south of Nova Scotia on Monday. High building from
the north Monday night will then remain in control through much
of the week, with an Alberta Clipper low passing to the west
Tuesday night into Wednesday. Another low may approach later in
the week into next weekend.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
-- Changed Discussion --
Main adjustment with this update was to delay the onset time of
PoPs as well as the timing of when rain becomes likely for most
areas by a few hours.
As sfc high pressure retreats tonight and an upper ridge axis
also moves east precip could arrive as early as shortly after midnight
W of NYC, then spread eastward overnight. Thermal profiles
support rain at the onset, then as the column cools should
become marginally supportive of snow across the interior. Temps
currently mostly in the 40s will eventually drop into the 30s
in all spots tonight, and to near freezing well NW of NYC.-- End Changed Discussion --
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
A tricky fcst across the interior as far as snowfall amts are
concerned. Think much of the interior will see a period of wet
snow mainly in the morning, but with marginal thermal profiles
and slow warming aloft snow ratios are very unlikely to be 10:1.
Most likely scenario is for a snowfall of 1-3 inches inland,
with the higher amts mostly in the higher elevations, and a
coating to an inch possible from W Passaic/W Bergen across
Rockland/N Westchester and across the coastal CT zones away from
the immediate shoreline, with little to no accumulation farther
south where precip should be primarily rain. Worst case
scenario looks to be an advy criteria snowfall of 2-4 inches,
especially for the I-84 corridor.
Mid level drying/warming arriving during Sunday afternoon and
evening should shut off the steadier/heavier precip, with any
snow changing mostly to light rain, with perhaps a transitional
pd of light freezing rain occurring in the highest elevations
of Orange and W Passaic.
As the sfc low passes E of Long Island Sunday night into Monday,
colder air wrapping around on the back side of the low should
allow any lingering precip to change back to snow or a rain/snow
mix, but with little to no subsequent accumulation.
Diurnal temp range will be fairly small, with highs on Sunday
mainly 35-40, lows 30-35 Sunday night, and highs on Monday in
the upper 30s and lower 40s.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
The long term period will feature mainly dry conditions with
normal to above normal temperatures.
Heights start to rise aloft Monday night while high pressure at
the surface noses in from the north. This high will continue
to sink south and remain in control through at least the middle
of the week. In the meantime, a clipper low and associated upper
low will pass to our west. At this time, our area looks to
remain dry with any precip from the low staying farther west,
but if the high trends weaker there is some potential for some
light rain/snow for far western locations.
Towards the end of the week the model spread starts to increase
a bit. There is signal for an upper level trough to approach
from the north and become closed over or near the area with an
associated surface low passing through. This brings the
potential again for light precipitation, but there is not much
moisture at all with this system. The Canadian has been showing
a different solution, with that late week upper level trough
being much less amplified as it approaches from the north. This
in turn could allow the earlier clipper low to strengthen closer
to the coast than the other guidance is showing. This solution
is the outlier right now and would just bring a higher chance of
rain and gusty winds.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
Low pressure approaching from the southwest overnight. The low
will pass south of the area on Sunday.
Primarily MVFR conditions for the next few hours. Flight
categories will then lower to IFR after around 08Z as
precipitation advances in from the SW. This is primarily a rain
forecast for all but KSWF, which at this time will feature a
rain/snow mix. For KSWF, this is a close call as temperatures
are very marginal. Should it stay mainly a wet snow, there is
the potential for a few inches. Temperatures will generally be
above freezing.
Winds mostly light and variable or with some easterly component,
becoming more NE-ENE late tonight into Sunday morning, increasing
to 10-15kt G20-25kt by 18Z Sunday. Highest winds/gusts will be
along the coast.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments are likely late tonight into Sunday for changing
flight categories and timing of strongest winds.
OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY...
Sunday night: IFR likely in rain. Potential for snow or a
rain/snow mix at KSWF. NE-N winds 10-20G20-30kt, highest along
the coast.
Monday: MVFR or lower. Chance of rain and snow in the morning. N
winds 15G20-25kt.
Tuesday through Thursday: VFR.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Gale warning issued for the ocean waters for daytime Sunday, as
E flow increases to 25-30G35-40kt in the afternoon as low
pressure develops along the Mid Atlantic coast. Winds will back
NE-N Sunday night, with the area of gales shifting E, so the
gale warning continues E of Moriches Inlet into Sunday night,
and may eventually need extension into Monday morning. Ocean
seas will peak at 6-10 ft during this time frame as well.
SCA issued for all other waters into Sunday night or Monday as
NE-E flow gusts to 25-30 kt and seas on the far ern Sound
build to 3-5 ft.
SCA conditions will linger on the ocean waters thereafter into
Tue night.
The next chance for a SCA looks to be at the end of the week
into next weekend, with low pressure dropping down from the
north.
&&
.HYDROLOGY...
Liquid equivalent amounts of 3/4 to around 1 inch are still
expected late tonight night into Sunday. Some of this will be
in the form of snow inland. No hydrologic impacts expected
attm.
&&
.TIDES/COASTAL FLOODING...
At this time, there are no plans to issue coastal flood
headlines. The wind forcing associated with the coastal storm
that will impact the area Sunday into Monday looks to be offset
from the time of high tide on Sunday. That being said, water
levels may encroach minor benchmarks, but confidence is too low
at this time to issue a statement.
While E-NE winds on Sunday veer around the N Sunday night into
Monday, a prolonged easterly swell as evidenced in much of the
guidance maintains waters levels 2 to as much a 3 ft above
normal into Tuesday. This will result in tidal piling and could
increase the chances of minor coastal flooding heading into
Monday. The limiting factors at this time would be offshore flow
and lowering astronomical tides.
Bottom line, still cannot rule out need for statements or
advisories along the south shore bays of Long Island and along
the western Sound for the high tide cycles Sunday into Monday.
Generally 2 1/2 ft of surge are needed for minor coastal
flooding, and 3 1/2 ft for moderate flooding. Potential for
dune erosion is low and localized.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from noon Sunday to noon EST Monday for
ANZ331.
Small Craft Advisory from noon Sunday to 6 PM EST Monday for
ANZ332-338-340-345.
Small Craft Advisory from noon Sunday to 6 AM EST Monday for
ANZ335.
Gale Warning from 6 AM Sunday to noon EST Monday for ANZ350.
Gale Warning from 6 AM to 6 PM EST Sunday for ANZ353-355.
&&
$$
SYNOPSIS...BG/JT
NEAR TERM...JC/BG
SHORT TERM...BG
LONG TERM...JT
AVIATION...JC
MARINE...BG/JT
HYDROLOGY...BG/JT
TIDES/COASTAL FLOODING...