000
FXUS61 KOKX 221721
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
121 PM EDT Fri Sep 22 2023
.SYNOPSIS...
High pressure will shift east towards Nova Scotia today and then
will move southeast of Nova Scotia out into the Atlantic
tonight. Meanwhile, a potential tropical storm takes shape off
the southeast coast and moves inland over North Carolina.
Moisture associated with this area of low pressure will work
northward and impact the area over the weekend and into early
next week. Behind it, high pressure builds south out of Canada
for mid- week.
For the latest forecasts on Potential Tropical Storm 16, refer to
the National Hurricane Center at www.nhc.noaa.gov and/or the NWS
New York office`s tropical page at weather.gov/okx/tropical
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Forecast still remains on track with minimal adjustments to
the forecast to account for current observations and trends.
High pressure moves farther away from the region today. Clouds
well out in advance of an approaching low are advancing
northward into the region today, decreasing total sunshine in
the afternoon.
Winds will be increasing out of the east, and along with the
extra clouds, will keep temperatures below normal. Winds will
become more gusty this afternoon, especially along the coast.
Max temperatures were a combination of MAV, MET and NBM, with
values ranging from the upper 60s to lower 70s.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
Main focus will be the increasing pressure gradient and
rainfall across the region in response to the approach of a
post-tropical low. The National Hurricane Center shows a
potential tropical storm transitioning to a post tropical
depression as it gets within relative closer proximity to the
local region. Please refer to the National Hurricane Center for
the latest track and intensity forecast of this low.
Winds appear to be too low for wind advisory across the local
region and rainfall while it could be heavy at times, appears
mostly as a long fused gradual rainfall event spread across from
late tonight through the entire weekend with a potential lull
Saturday night. So, flood chances are low.
The increasing gusty easterly flow Friday night will achieve a
maximum Saturday into early Sunday with wind gusts up to near 30
to 40 mph mainly. Some locally higher gusts to near 45 mph could
very well occur. Winds start to decrease more Sunday night.
Rainfall increases in response to increased jet dynamics this
weekend and approach of cutoff upper level low as well as the
post tropical low from the south. Rainfall intensities look to
remain below 1 inch in 1 hour. Rainfall will be more gradual.
Elevated instability conveyed by some models across the area
with near 0 to slightly negative Showalter Indices this
weekend, but kept mention of thunderstorms just isolated or a
slight chance.
Minimal diurnal temperature range is forecast. Lows at night
mostly in the mid 50s to near 60. Highs during day Saturday only
in the mid 50s to lower 60s and for Sunday in the low to mid
60s.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
By Monday, the low pressure system will gradually weaken and slowly
slide eastward as it passes south of the area. With the low still in
the vicinity of the region, expect additional rainfall on Monday,
and possibly even into Tuesday, depending on how long it takes this
system to exit and if/how it interacts with an upper level shortwave
passing through at the time. We are then expecting drier conditions
mid-week as Canadian high pressure noses south, holding temperatures
down a bit below normal values through mid next week. Another chance
of rain comes Thursday into Friday, however chances remain rather
low at this point.
&&
.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --
*High impact aviation weather likely Saturday*
High pressure gradually slides east this afternoon with VFR
conditions. Coastal low pressure well south of the region will
move inland over the Carolinas tonight and start to lift
northward with rain and MVFR conditions developing after 08z
Saturday....IFR expected to develop by 15z. The rain will
become more widespread and moderate to locally heavy after 12z.
Rain should become showery in nature Saturday afternoon and
evening.
E winds increase to 10-15kt with gusts to 25kt this afternoon.
The gusty east winds are expected to remain much of the night
and into Saturday with gusts to 35 kt possible by
midday. Strongest winds likely at coastal terminals points
east. Winds should decrease slightly toward Sat evening.
LLWS remains a possibility, but confidence is too low to
include in the TAFs at this time. Best chances for LLWS will be
across the coastal terminals and points east.
.NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of MVFR or lower cigs may be off by an hour or two late
tonight into Saturday morning.
Amendments likely Saturday for changing flight categories.
OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...
18z Saturday and Sunday: MVFR or lower likely in rain with
possible embedded thunder. Gusty winds to 30kt possible,
Monday: Mainly VFR. MVFR possible in showers.
Tuesday: Mainly VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Conditions become more rough on the waters during the day today
starting with the ocean as well as NY Harbor and the South
Shore Bays, and all waters tonight. SCA begins 8am this morning
for all ocean zones and SCA begins at 12pm this afternoon for NY
Harbor and South Shore Bays. Tonight, all waters are in SCA.
For Saturday and Saturday night, gales are expected across the
ocean and will be possible for non-ocean waters. Gale warning in
effect for Saturday and Saturday night across the ocean and a
gale watch is in effect for the same time period for the non-
ocean waters. Gales could very well linger on Sunday and then
more of SCA level conditions are forecast Sunday night.
SCA conditions remain on the ocean waters through at least Monday
night with winds and seas above criteria. Conditions start to fall
below SCA criteria on Tuesday, then remain below SCA through mid-
week.
&&
.HYDROLOGY...
Storm total rainfall of near 2 to 3 inches forecast for much of
the region from late tonight through Sunday night. Maximum
hourly rates appear to be mainly around a quarter to half inch.
There will be a low chance for flash flooding especially for any
locations that get locally more than 3 inches and if those
locations are poor drainage and low-lying.
&&
.TIDES/COASTAL FLOODING...
There is a high rip current risk for all Atlantic facing beaches
through Saturday early evening with building onshore waves with
long period swell from mainly the east.
A high surf advisory has been issued for all coastal zones of
Long Island, including the ocean shorelines of Brooklyn and
Queens for Saturday into early Saturday evening. Breaking waves
of 6 to 11 ft are forecast.
This will likely lead to beach erosion. There will also be
potential for coastal flooding across high tide cycles this
weekend and possibly into early next week.
Localized moderate coastal flooding will be possible for some
shorelines of the bays of Central and Eastern LI as well.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...Coastal Flood Advisory from 4 PM to 8 PM EDT Saturday for
CTZ009.
NY...Coastal Flood Advisory from 4 PM to 8 PM EDT Saturday for
NYZ071.
Coastal Flood Advisory from 1 PM to 5 PM EDT Saturday for
NYZ074.
High Risk for Rip Currents through Sunday evening for NYZ075-080-
081-178-179.
High Surf Advisory from 6 AM Saturday to 11 AM EDT Sunday for
NYZ075-080-081-178-179.
Coastal Flood Advisory from 1 PM to 7 PM EDT Saturday for
NYZ178-179.
NJ...Coastal Flood Advisory from 1 PM to 5 PM EDT Saturday for
NJZ006-106-108.
MARINE...Small Craft Advisory from 6 PM this evening to 6 AM EDT
Saturday for ANZ331-332-335-340.
Gale Watch from Saturday morning through late Saturday night
for ANZ331-332-335-338-340-345.
Small Craft Advisory until 6 AM EDT Saturday for ANZ338-345-
350-353-355.
Gale Warning from 6 AM Saturday to 6 AM EDT Sunday for ANZ350-
353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...BC/JM
NEAR TERM...JM/BR
SHORT TERM...JM
LONG TERM...BC
AVIATION...IRD
MARINE...BC/JM
HYDROLOGY...BC/JM
TIDES/COASTAL FLOODING...