discussion on 2023-11-26

000
FXUS61 KOKX 261602 CCA
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
938 AM EST Sun Nov 26 2023

.SYNOPSIS...
High pressure continues to slowly move off the New England coast
today. Low pressure then impacts the area late today, tonight, and
into early Monday morning. High pressure slowly builds into the
region Monday through Tuesday night, and noses in from the south
on Wednesday, and then weakens as low pressure passes to the
north. The high, centered to our south and east, remains in
control through at least early Friday. Low pressure impacts the
area late Friday into the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --A weak surface low is beginning to take shape off Cape Hatteras
this morning, and will gradually deepen as it works its way up
the coast today, tracking over the region tonight. Ahead of this,
increasing SE winds should help temperatures rebound from the cold
start and highs should get close to 50 this afternoon along the
coast. Nudged PoPs up a tad late this afternoon as some of the
latest CAMs are indicating the rain could develop by 20Z or 21Z in
parts of the area. Otherwise, forecast remains on track and previous
discussion follows.

Large upper trough will be approaching from central Canada and
the central United States today and passing through the region
today, with the trough axis passing offshore by 12Z Monday.
Southern energy phasing with the trough will developing a low
off the North Carolina coast and as the upper trough become
negative tonight the low will be deepening and tracking along
the coast. With the progressive nature of the trough the surface
low quickly passes through the region tonight, and will be well
to the north Monday. With strong isentropic forcing developing
this afternoon ahead of the deepening low precipitation chances
will be increasing from the south. Precipitation will be
possible by late in the day. And, with the strong lift and an
increasing low level jet, a period of moderate to heavy rainfall
will be possible tonight. With the quick moving system rainfall
amounts have lowered a little from previous forecast cycles.-- End Changed Discussion --

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Rain will be quickly ending across the east and northeast
portion of the region early Monday as the surface low wraps up
and tracks to the northeast and north. Gusty winds, and a cold
airmass moving into the region will be the main effects in the
wake of the low Monday through Tuesday night, as the low
continues to deepen across eastern Canada and high pressure
builds to the west. Also, with cyclonic flow continuing a weak
surface trough will be rotating into the region late Monday
night into Tuesday, and with a strong westerly flow, with
moisture coming off Lake Erie, and cold air in place a few
flurries will be possible across the interior during Tuesday,
and have added this to the forecast.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Guidance is generally in agreement Wednesday through the first
half of Friday. The long term period starts off with high
pressure nosing in from the south as the flow becomes zonal
aloft. The high quickly gets suppressed to the south as low
pressure passes well to our north as it tracks through Canada.
The high remains centered to our south and east through early
Friday and results in a long period of southwesterly flow. This
will allow for a warming trend. High temperatures on Wednesday
will be in the mid 30s to low 40s and by Friday they will be in
the upper 40s to mid 50s. Long Island and the CT coast will be
on the warmer side of this range each day due to the flow off
the warmer waters.

Late Friday and into the weekend is where the model spread
starts to increase. There is agreement on an upper level low
moving on the west coast from the Pacific and then opening up as
it digs down into the southwest CONUS. This shortwave then
lifts through the central CONUS towards our area. The
disagreement is in the associated surface low, with difference
in strength, timing and location. Ended up going a bit lower
than the NBM with the PoPs due to low confidence. PoPs start
Friday afternoon and peak Friday night, with lingering PoPs
through the weekend. At this time, thermal profiles show an all
plain rain event. The NBM currently shows a 10-15% chance of 1
inch of rain during any 24 hour period during this event.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
High pressure shifts farther offshore today. Low pressure
impacts the area tonight into Monday morning.

Mainly VFR this morning with MVFR bkn025-bkn030 developing this
afternoon. MVFR becomes widespread this evening as rain
develops. IFR likely develops 01-03z with the rain becoming
moderate overnight. The rain will quickly end from southwest to
northeast early Monday morning with conditions improving to
MVFR and then VFR around day break Monday.

NE-E winds to start will gradually become SE this afternoon
around 10 kt. Winds increase through this evening, peaking at
12-17 kt. There may be some gusts at KISP, KBDR, and KGON, 25-30
kt overnight. The low pressure will pass directly overhead
leading to a period of a low confidence wind forecast around
04z-08z, especially at NYC terminals. As the low pulls away,
winds eventually become W and start to increase again early
Monday.

Higher confidence in LLWS farther east and have added in the TAF
for KBDR, KISP and KGON 03z-08z. Less confidence farther west
but can not completely rule out a brief period of LLWS at KJFK
and KLGA.

 ...NY Metro(KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

Timing of lowering ceilings to MVFR late morning/early afternoon
may be off by 1-2 hours and lowering to IFR may be off by 1-3
hours.

Low confidence wind direction forecast around 04z-08z due to
the track of low pressure.

OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY...

Mon: Improvement to VFR in the morning. WNW wind 15-20kt, G25-30kt.

Tue: VFR. W wind 15-20kt, G25-35kt.

Wed: VFR. SW wind 10-15kt, G20kt.

Thu: VFR. W wind 10-15kt, G20kt.

Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90

&&

.MARINE...
High pressure will be moving further off the New England coast
today as a deepening low off the North Carolina coast tracks
toward the region by late in the day and then across the
forecast waters tonight, moving quickly to the northeast late
tonight into Monday. Small craft advisory conditions are
expected to develop across all but the New York Harbor waters
tonight, and then in the wake of the low Monday, SCA conditions
are also expected on New York Harbor. There may be a break of a
few hours when conditions are below advisory levels late tonight
as the low tracks through the waters. However, with the brief
break, and then winds and wave increasing in a westerly flow
have issued a SCA for all but the New York Harbor beginning
tonight and continuing through Monday night, and then including
New York Harbor Monday through Monday night.

As the low tracks northerly into eastern Canada Monday through
Tuesday, and deepens, the pressure gradient across the forecast
waters will be increases as high pressure also builds slowly to
the west. Small craft advisory conditions will remain on the
forecast waters Tuesday and Tuesday night, and there is a chance
that gusts reach gale force on the ocean waters Tuesday
afternoon into Tuesday evening, and possibly on the Long Island
bays and Long Island Sound for a few hours Tuesday evening.

SCA conditions continue Wednesday through at least Thursday as
the area remains in between high pressure to the south and low
pressure to the north. 25 to 30 kt gusts are possible across all
waters during this time period except the NY Harbor and the
western LI Sound. On the ocean waters, waves will be 4 to 6 ft.
Sub SCA conditions then expected through the weekend, although
the forecast winds and waves can trend higher with low pressure
impacting the area.

&&

.HYDROLOGY...
A period of locally heavy rainfall is possible late this evening
into tonight. While the risk for flash flooding is low, nuisance
flooding of urban and poor drainage areas is a possibility. Total
rainfall into early Monday morning generally ranges from a half
inch to one inch.

There are no hydrologic concerns Tuesday through the weekend at
this time.

&&

.TIDES/COASTAL FLOODING...
Astronomical tides will be increasing into early next week due
to a full moon early Monday morning. Water levels should fall
just below minor benchmarks during the this mornings high tide
for a few vulnerable locations across the south shore back bays
of Nassau, the NY Harbor and along coastal Fairfield.

Minor coastal flooding looks more likely for the south shore back
bays of Nassau and Queens, the Lower NY Harbor and the bays along
the SE coast of Long Island with the Monday morning high tide. A
quickly developing low pressure may help bring enough of a surge
(only around 0.50-0.75 ft needed) to reach minor benchmarks.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 6 PM this evening to 6 AM EST
     Tuesday for ANZ331-332-335-340-345-350-353-355.
     Small Craft Advisory from 6 AM Monday to 6 AM EST Tuesday for
     ANZ338.

&&

$$

SYNOPSIS...MET/JT
NEAR TERM...DR/MET
SHORT TERM...MET
LONG TERM...JT
AVIATION...DS/JT
MARINE...MET/JT
HYDROLOGY...MET/JT
TIDES/COASTAL FLOODING...