000
FXUS61 KOKX 202351
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
651 PM EST Thu Feb 20 2020

.SYNOPSIS...
High pressure over the Central States will be in control through
Friday. The high pressure settles south of the area Friday night
into much of the weekend and then offshore Sunday night. A
frontal system approaches early next week with the passage of a
weak low near the area Tuesday into Tuesday night. Another
frontal system approaches Wednesday and moves near the region
Wednesday night into Thursday.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Some slight adjustments were made to the forecast grids to
increase clouds this evening with otherwise just a few degrees
adjustments to near term temperatures and dewpoints to better
match observed trends. The forecast overall is on track.

A middle and upper level trough axis approaches this evening and
moves across the Tri-State overnight. The approaching trough
axis will push the strong upper level jet streak offshore
tonight. This will effectively take the middle and upper level
moisture with it and begin clearing skies from north to south
overnight. A weak surface trough associated with the upper
trough may develop some stratocu as it passes. Subcloud layer
looks too dry to support any flurries, so have left out of the
forecast.

A reinforcing shot of cold air moves in tonight once the trough
axis swings across. Cold and dry advection take place
overnight under a northerly flow, which may increase winds a
bit especially near the coast. A few gusts to 25 mph cannot be
ruled out. Temperatures will fall well into the teens for most
locations, with the NYC Metro falling to around 20 degrees.
Wind chills will be in the single digits for most locations
early Friday morning.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
A surface and upper ridge axis build over the region on Friday.
The atmosphere is dry from the surface to the upper levels with
strong subsidence from the ridging. Dry and chilly conditions
are expected on Friday with temperatures ranging from around 30
degrees inland to the middle 30s near the coast, 5 to 10 degrees
below normal for this time of year.

Clear skies continue Friday night with the ridge axis shifting
offshore and the core of the surface high building to our
south. Winds will shift to a W-SW direction around the high
pressure, beginning the process of moderating temperatures. Have
gone on the warmer side of guidance with lows Friday night due
to the developing southwest flow. Outlying locations stand the
best chance at radiational cooling and temperatures.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Looking at 250mb wind speed, the local region for the weekend will
be in between northern and southern branches of the upper level
jet. The jet bends more early next week with more SW meridional
component flow developing and traversing the local area.

Left front quad of upper level jet moves in early Tuesday and whole
upper level jet amplifies and strengthens Tuesday night into
Wednesday with the local region again being in left front quad of a
strong jet streak. The jet streak will still be over the area
Wednesday night into early Thursday and then the jet streak
shifts east of the region for the remainder of Thursday.

Mid level pattern exhibits quasi-zonal flow for the weekend with
more amplified increasing meridional flow for much of next week.

At the surface, high pressure will be anchored in the Southeast US
for Saturday through Sunday and then will move eastward off the
Southeast into the Atlantic Ocean Sunday night. Dry weather is
expected through the weekend.

A more unsettled weather pattern develops next week because of the
more active jet and its close proximity to the region. One low
pressure system will be making its way towards the region Monday
into Monday night. The parent low of the system tracks well west and
weakens with another small low that will be moving nearby Tuesday
into Tuesday night. There will be some shortwave positive vorticity
advection in the mid levels Tuesday. Synoptic pattern keeps the
region warmer so this upcoming precipitation event will be in
the form of rain. The rain Tuesday into Tuesday night will be
mainly light to moderate.

For Wednesday, the region gets a brief lull in rain with the region
being in between low pressure systems. This next one will be
moving in from the south and west Wednesday night into Thursday
and could potentially be a stronger system but with a track of
the low across western parts of the region, mainly rain is
expected once again with a chance of a wintry mix across the
interior. A lot of uncertainty with this second system as it is
about a week ahead in time so models may very well fluctuate
from run to run with its depiction of the strength, position and
track of the parent low associated with the system.

Temperatures overall through much of the long term are forecast to
be several degrees above normal.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
High pressure remains across the terminals through the forecast
period with VFR conditions.

Mid and high level clouds this evening will clear the area
after 04z. SKC the remaining part of the TAF period.

Winds generally NW-N around 10 kts tonight. Gusts develop late
tonight up to 20 kt, and continue into early Friday morning.
Gusts may be more occasional than frequent. During Friday the
winds back W and SW, and remain under 10 kt.

.OUTLOOK FOR 00Z SATURDAY THROUGH TUESDAY...
.Friday night through Sunday night...VFR.
.Monday...VFR during the day. A chance of rain with MVFR or
lower Monday night.
.Tuesday...Rain likely with MVFR or lower.

&&

.MARINE...
An increasing pressure gradient on the waters will increase
winds through the night. The winds on the ocean waters should
come close to 25 kt in gusts. The SCA remains in effect from 05z
to 17z Friday. However, the strongest winds look to occur early
Friday morning and the advisory may be cancelled sooner than
17z. Air temperatures dropping into the low 20s early Friday
morning combined with the stronger winds on the ocean bring a
chance for light freezing spray. Otherwise, sub-SCA conditions
are forecast through Friday night.

Outside of some marginal SCA gusts on Saturday across the
ocean, sub-SCA conditions are expected for the weekend through
Tuesday across the waters. SCA seas are possible on the ocean
Tuesday night.

&&

.HYDROLOGY...
No hydrologic issues are expected through Monday.

Widespread rainfall is forecast Tuesday into Tuesday night with
potential for around 1 inch but confidence is low on exact amounts.
With rain expected to be spread out over a long period of time, no
hydrologic issues are expected. Too much uncertainty to assess any
potential issues with the second system next week yet.

&&

.EQUIPMENT...
NYC NOAA Weather Radio Station KWO35 (162.55 MHz) is still
operating at reduced power.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from midnight tonight to noon EST Friday
     for ANZ350-353-355.

&&

$$
SYNOPSIS...JM/DS
NEAR TERM...JM/DS
SHORT TERM...DS
LONG TERM...JM
AVIATION...IRD
MARINE...JM/DS
HYDROLOGY...JM/DS
EQUIPMENT...

NWS OKX Office Area Forecast Discussion