841
FXUS61 KOKX 252002
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
402 PM EDT Fri Sep 25 2020

.SYNOPSIS...

Remnants of Beta is expected to pass south of Long Island Saturday
as an upper level shortwave moves through southern New York. Weak
high pressure based in the Western Atlantic will remain across the
region Sunday through Monday.  Meanwhile, a very weak low pressure
system will be passing offshore. A cold front approaches Monday
night into Tuesday, moving in Tuesday and across the area late
Tuesday night into Wednesday. The front may slow down and stall near
the region Wednesday night into Thursday with a greater push of the
front offshore by next Friday.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...

Trough over the Mid-Atlantic promotes south winds which bring
moisture from the remnants of Beta locally into Long Island and
southern Connecticut. Could see a situation tonight similar to
last night where after midnight patchy fog should form initially
in the interior portions of Long Island and along the
Connecticut coast then gradually spread throughout the forecast
area. Over head clouds may hold dense fog at bay but with dew
points in the low 60s the possibility can not be ruled out.
Ambient temperatures hover in the low 60s as well prior to
sunrise. Any fog that does form should begin to dissipate
shortly after sunrise between 12-15Z.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...

Cloudy day expected Saturday mainly stemming from the outer low
moisture level from Beta. This main plume of moisture enters the
area early to mid Saturday as a warm front. Precipitable water
values increase to around 1.5 inches meaning there`s a slight chance
of rain from isentropic showers throughout the day. In the afternoon
temperatures should reach the low to mid 70s despite the cloud cover.

Clouds remain into the overnight hours and with the elevated
moisture could see another round of patchy fog in the overnight.
Temperatures overnight will be slightly higher than the previous
night in the mid 60s to start the day.

There is a moderate risk of rip currents at the Atlantic Ocean
beaches on Saturday due to a continued E-SE swell.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...

Ridge based well out into Western Atlantic across the region with
high surface at the surface to close out the weekend and into
Monday. A weak shortwave in combination with a very weak low passing
offshore will make for some isolated to scattered rain shower
activity Sunday through Sunday Night. The higher PVA and strongest
dynamics move across Monday.

Shortwave and strongest dynamics pass east of the region Monday
night into early Tuesday before another longer shortwave associated
with the cold front approach. Strongest dynamics with the front and
trough aloft move in Tuesday night into Wednesday. On the larger
scale, a large trough in the upper levels remains across the Ohio
and Tennessee Valleys mid to late in the week. The result at the
surface will be a slower progression of the front, with it lingering
near the region Wednesday into Thursday. Stronger positive vorticity
advection heading into next Friday with a deeper trough will push
the front farther offshore.

In terms of weather, showers remain in the forecast through much of
the long term. Likely POPS Tuesday night into Wednesday morning show
when the strongest dynamics with cold front moving across from a
model consensus. However, models do exhibit quite a difference in
surface and mid level height fields and associated surface
precipitation with vast differences in timing between the ECMWF and
the GFS.

Temperatures overall are forecast to be several degrees above normal
Sunday through Tuesday and closer to normal thereafter.

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
High pressure will remain over the Atlantic through Saturday.
Meanwhile, a dissipating low will move off the mid-atlantic
coast.

Mainly VFR today. S-SW flow around 5-10 kt are expected this
afternoon. KEWR/KTEB should shift SE late afternoon, with
speeds at KJFK around 10 kt.

Patchy IFR fog is possible tonight, mainly across the outlying
terminals. NYC terminals could see some conditions fall to MVFR.
CIGs in the 3-4k ft range move in towards daybreak on Sat, and
are expected to lower closer to 2 kft closer 14z.

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

Moderate confidence on winds today. Uncertainty on Saturday with
respect to how low the cigs will be.

.OUTLOOK FOR 18Z SATURDAY THROUGH TUESDAY...
.Saturday through Sunday...Chance of late night/early morning fog
with IFR conditions. VFR/MVFR cigs expected.
.Sunday night...Chance of MVFR conditions with any showers
late.
.Monday and Tuesday...Chance of MVFR conditions with any
showers or isolated afternoon tstms. S-SW winds G20-25kt.
.Wednesday...Mainly VFR.

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

&&

.MARINE...

Light southwest winds 5-10kts through the near term with waves 2 to
3 feet. Winds pick up slightly over the ocean waters Sunday as
the remnant low of Beta moves south of Long Island.

SCA level winds forecast across mainly the ocean with the cold front
passage Tuesday night into early Wednesday. SCA levels seas on the
ocean Tuesday night through Thursday.


&&

.HYDROLOGY...
No hydrologic impacts are anticipated at this time through the
forecast period.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.

&&

$$
SYNOPSIS...DJ/JM
NEAR TERM...DJ
SHORT TERM...DJ
LONG TERM...JM
AVIATION...BC
MARINE...DJ/JM
HYDROLOGY...DJ/JM

NWS OKX Office Area Forecast Discussion