000
FXUS61 KOKX 161139
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
639 AM EST Sat Dec 16 2023
.SYNOPSIS...
High pressure over the region shifts east tonight. Strong low
pressure then approaches from the south on Sunday with its
center passing northward through or just west of the Tri-State
Area on Monday. In the wake of the exiting low, high pressure builds
in from the west through Wednesday, remaining in place into
late next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
The forecast is mainly on track. Minor adjustments made mainly
to hourly temperatures and dewpoints for the next few hours.
High pressure builds in at the surface and aloft today. Sunshine
mixes with some cirrus this morning with more in the way of
clouds this afternoon. High temperatures will be around 50,
which is about 5 degrees above normal.
Easterly winds for tonight as the high pressure center moves through
the southern Canadian Maritimes. This will increase low level
moisture and bring cloudy conditions across the region. Models show
a push of isentropic lift from the SE towards daybreak, so with
fairly shallow moisture in place, maybe some light rain or drizzle
will be possible late at night. Turbulent mixing near the top of the
mixed layer looks sufficient to preclude fog formation. The cloud
cover will keep keep low temperatures above normal.-- End Changed Discussion --
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
-- Changed Discussion --
Low pressure over the Southeast on Sunday shifts north and deepens
with help of some phasing energy aloft. The center of the low passes
over us or just off to our west on Monday as it continues to
strengthen and head north towards SE Canada. Rain chances increase
through the morning, with rain likely in the afternoon. The rain
could be heavy at times Sunday night into Monday morning as a low
level jet interacts with an anomalously moist air mass. Models
continue show a little instability during this time as well. CAMs
also show a convective line potentially reaching some portions of
the forecast area late Sunday night/early Monday morning. So with
upward forcing from both the llj and near the deepening low center,
a thunderstorm with heavy downpours cannot be ruled out. Flooding
impacts will be possible starting late Sunday night and lasting into
Monday. Have held off on issuing a Flood Watch at this time as
forecast rain amounts have lowered slightly from the previous
forecast. Additionally, the highest rain amounts would generally
occur along and just west of the storm center track, which
potentially ends up just west of the forecast area. Impacts wouldn`t
begin until late Sunday night, so will allow the next shift to
assess new guidance before making any decisions. See the hydrology
section for more details. Rain will still be possible during Monday,
with generally lowering chances through the day. It`ll be quite mild
with high temperatures mostly 55-60. Some record high temperatures
will be approached.
There is at least more confidence regarding wind impacts for this
event. 925mb winds are progged at 60-85kt along with 55-70kt at
950mb over coastal sections late Sunday night/early Monday morning.
It appears that the low level inversion will be at least a little
weaker than with this past Sunday-Monday`s storm as temps aloft
would be cooler with SE winds instead of S-SW like the previous
system. Thinking there`s potential for 60-70% of the 925mb winds to
mix down to the surface, especially in the heavier downpours. After
collaboration with the surrounding offices, have issued high wind
watches and wind advisories as models continue to show a strong llj,
heavy downpour potential, and a storm track that would promote wind
headlines for these zones. Unlike the previous storm, NBM
probabilities of 45+ mph gusts have been increasing as we get closer
to the event - increasing the forecast confidence. Even with the llj
out of the picture by late Monday morning, the rest of Monday should
still be at least breezy as SW to W winds gusts to 30-40mph.-- End Changed Discussion --
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Surface low pressure tracks well north into the St. Lawrence River
Valley to start the period, as the parent upper trough axis swings
east, allowing colder air to work into the region.
Tapering precipitation Monday night into early Tuesday, though
lingering flurries or snow showers are possible through Tue
afternoon as a blustery NW flow helps to advect in a colder air
mass. Otherwise, a much drier regime develops in the system`s wake
as a strengthening surface high builds east. Ridging largely remains
in place through late week, maintaining the dry, tranquil conditions.
Tuesday appears to be the coldest day of the period under CAA, with
highs otherwise in the 40s for most, or near normal for the time of
year.
&&
.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
VFR through early this evening, MVFR cigs look to develop after
03-06Z Sunday for the coastal terminals under easterly flow,
expanding to the interior terminals as the night progresses.
WNW flow under 10 kt early this morning at the metro terminals,
and light and variable at the outlying terminals. Winds remain
at or under 10 kt this afternoon, becoming northerly, then easterly.
Lowering cigs after 00Z Sun, and patchy drizzle possible by late
Sun AM.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
The afternoon haze potential forecast is YELLOW, which implies slant
range visibility 4-6SM outside of cloud.
There is uncertainty in the onset timing of MVFR cigs. IFR cigs
possible after 9Z Sun.
OUTLOOK FOR 06Z SUNDAY THROUGH WEDNESDAY...
Late tonight: MVFR cigs developing, with a slight chance of light
rain or drizzle toward Sunday morning.
Sunday: Rain with MVFR to IFR conds. E winds G20-25kt along the
coast.
Sunday night and Monday: IFR to LIFR in rain, possibly heavy at
times. Isolated thunderstorms possible. SE winds G30-45kt along the
coast, becoming S Monday afternoon G25-30kt, and then SW to W
diminishing late Monday afternoon and night. LLWS late Sunday night
into Monday morning, with 2Kft winds 70-85kt possible.
Tuesday: Chance of a few flurries or snow showers mainly north and
west of the NYC terminals. MVFR, possibly IFR, especially in any
snow showers.
Wednesday: 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 --
Relatively tranquil conditions will continue on all waters today
and tonight. Winds and seas then ramp up on Sunday, but more so
Sunday night into Monday. After collaboration with the
surrounding offices, have issued a Storm Watch for all waters.
The strongest winds are likely to occur late at night Sunday
into Monday morning, but as per local policy, have issued the
watch starting Sunday evening. Marginal SCA conds will be
possible on the ocean during Sunday, but decided to hold off on
issuing an advisory as conditions will deteriorate in the
following period. Additionally, gales are still probable on most
waters Monday afternoon. Wave heights on the ocean peaking at
16-21ft Monday.
Beyond Monday night model guidance spread increases. This leads to a
low confidence win forecast Tuesday through Thursday. At this time,
winds are forecast to remain below 25 kt, but SCA conditions
continue on the ocean waters with elevated wave heights. Waves by
the Race in eastern LI sound could be up to near 10ft.
Winds lower Monday night as low pressure pulls away from the region,
and gusts may fall below 25 kt for a period into Tuesday morning.
These likely return Tuesday afternoon with enhanced NW flow, before
subsiding once again everywhere Tuesday night. Thereafter, sub SCA
conditions are expected on non ocean waters as high pressure remains
in control through late week. Seas will likely remain elevated above
SCA criteria on the ocean waters into late next week.-- End Changed Discussion --
&&
.HYDROLOGY...
-- Changed Discussion --
Any rain that occurs Sunday morning will be light. Rain is then
expected Sunday afternoon and continues into Monday. The rain
is expected to be moderate, with periods of heavy rain Sunday
night (mainly late) into Monday morning. A widespread 2 to 3
inches of rain is expected with locally higher amounts possible.
There`s a good chance of minor urban and smaller river/stream
flooding, but still a low chance of flash flooding. With that
said, the areas that would be more prone to flash flooding would
be NE NJ into the Lower Hudson Valley. Flooding impacts are
more likely to begin late Sunday night into Monday.
Residual riverine flooding is possible Tuesday in the wake of
exiting low pressure, otherwise, no hydrologic issues expected
mid to late next week.-- End Changed Discussion --
&&
.TIDES/COASTAL FLOODING...
Coastal flood watches will likely be issued later today for
much of southern Queens, southern and eastern portions of LI and
coastal CT as potential has increased for more widespread
moderate coastal flooding with the daytime high tide cycle on
Monday. Elsewhere minor to moderate coastal flood potential is
increasing.
Along the ocean beachfront, potential exists for 12+ ft
breakers Sunday overnight into Monday, which combined with
elevated water levels, would result in widespread dune erosion
and scattered overwashes along the ocean shores.
There is still a good bit of spread in the storm surge guidance
for Monday afternoon, due to spread in exact storm track and
intensity as it moves up the coast. A track more to the west
would place the area more squarely under the strongest winds and
increase the threat for widespread moderate to locally major
coastal flooding for the most vulnerable portions of the area.
A more easterly track would lessen the threat. More clarity on
these scenarios likely over the next 24 to 36 hrs.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Wind Advisory from midnight Sunday night to noon EST Monday
for CTZ005>007.
High Wind Watch from late Sunday night through Monday morning
for CTZ008>012.
NY...Wind Advisory from midnight Sunday night to noon EST Monday
for NYZ071>074.
High Wind Watch from late Sunday night through Monday morning
for NYZ075-078>081-176>179.
NJ...Wind Advisory from midnight Sunday night to noon EST Monday
for NJZ006.
MARINE...Storm Watch from Sunday evening through Monday afternoon for
ANZ331-332-335-338-340-345-350-353-355.
&&
$$
SYNOPSIS...JC/DR
NEAR TERM...JC
SHORT TERM...JC
LONG TERM...DR
AVIATION...DR
MARINE...JC/DR
HYDROLOGY...JC/DR
TIDES/COASTAL FLOODING...