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000
FXUS61 KOKX 230227
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1027 PM EDT Thu Oct 22 2020

.SYNOPSIS...
A mild, humid airmass will remain in place through the end of the
week. A cold front will move through on Saturday, followed by high
pressure building to the north Saturday night into Sunday. A
frontal system will then impact the area through the middle of
next week.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
High pressure along the New England coast will keep the area
under a light, moist southerly flow. Areas of fog, and possibly
drizzle, along the coast will expand north and west across the
interior overnight.

Because guidance is mixed in supporting the development of
widespread 1/4sm vis or less, a dense fog advy has not been
issued. This does not rule out the potential for dense fog to
develop tngt, along with the need for a possible short fused
advy.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
A drier llvl airmass will attempt to gather across ME tngt,
then advect swwd into or close to the fcst area thru Fri. The
latest progs suggests it may at least reach the far ern portion
of the cwa. Confidence is low however with this amount of
precision. The modeling then indicates that even this wedge of
dry air will be overcome by the continual moist onshore flow Fri
ngt.

Therefore, fog and dz is expected late into Fri mrng, then some
sprinkles or patchy dz for the rest of the day west of this dry
air slug. Fog and dz is then expected to expand again Fri ngt
across the entire area. Time heights indicate a little
subsidence Fri ngt, so this may have some impact on the coverage
of fog and dz. As a result, went only with patchy in the fcst
for now.

For temps, if we were to mix down from h85 highs would be near
80. But this is not the case, and despite the warm temps aloft,
highs in the mid 60s are expected. The NBM was used with the
typical local adjustments thru the period.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Little overall change in the upper air pattern as the mean
upper trough across the Northern Plains and Upper Midwest
gradually translates slowly east through the period. This
will mean above normal heights and ridging across the western
Atlantic and eastern seaboard. Global models are generally
pointing to a pattern change toward the end of period as the
upper trough works into the northeast quarter of the country.

The biggest change in the extended is the handling of the
frontal system that impacts the area late Sunday night through
mid week. There is had been good agreement in the prior days
runs with a cold frontal passage on Tuesday, followed by high
pressure for the second half of the week. Both the 12Z ECMWF and
GFS now stall the front across area Tuesday with the potential
for multiple frontal waves traversing the region with rain
Tuesday night into Wednesday. The ECMWF is much quicker in
sending the front southward on Wednesday and drying conditions
out, while the GFS continues to load up with southern branch
energy as a closed upper moving into to the Lower Mississippi
shears out to the northeast. Complex interaction between
northern branch shortwave energy dropping into the mean trough
and the interaction with the aforementioned closed upper low
emerging from the Southern Plains will likely result in several
different solutions in coming days until the guidance locks onto
a solution. The GGEM is completely at odds with the both the
GFS and ECMWF, but does interestingly stall another boundary mid
week. Bottom line, forecast is more of a consensus of the ECMWF
and GFS. Thus, looking at inclement weather with a chance of
showers/rain late Sunday night through middle of the week.
Timing will be better resolved as the event approaches.

Prior to then, a dry cold frontal passage on Saturday will be
followed a quick shot of cool air on Sunday before moderating
back to just above seasonable levels for much of the period.
Unseasonably cold air looks to arrive late next week.

&&

.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
High pressure will remain over the terminals through Friday
morning, and drift east Friday afternoon as a cold front
approaches.

IFR to LIFR will remain through the overnight hours into early
Friday morning. Conditions will be improving slowly to MVFR
Friday morning, then remain MVFR through the remainder of the
forecast.

Winds remain light and variable to near calm until Friday
morning when a light SE flow develops.


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

Uncertainty with the timing and flight category changes through
Friday. Amendments for fluctuations in flight categories
through Friday. Low confidence forecast.


.OUTLOOK FOR 00Z SATURDAY THROUGH TUESDAY...
.Friday night...MVFR with IFR at times.
.Saturday...MVFR becoming VFR in the afternoon.
.Sunday...VFR. N winds G15-20kt AM push.
.Sunday night-Tuesday...Chance of showers with MVFR possible.

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

&&

.MARINE...
A dense fog advisory has been issued for all waters as moist S
winds traverse the cooler waters with fog forecast to expand
through the night.

Swells from Epsilon have arrived and a SCA remains in effect
thru Saturday night on the ocean. Areas of fog will result in
low vis at times thru Fri ngt on all waters.

Long period swells will be highest Friday night through Saturday
night, then gradually subsiding Sunday through Tuesday. There
will be gusts up to 20 kt on the ocean waters late Saturday
night through Sunday as strong high pressure passes to the
north and low pressure approaches from the southwest.

Please refer to National Hurricane Center products for further
details on Epsilon.

&&

.HYDROLOGY...
No hydrologic impacts are expected thru the forecast period.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Dense Fog Advisory until 10 AM EDT Friday for ANZ330-335-338-
     340-345.
     Dense Fog Advisory until 10 AM EDT Friday for ANZ350-353-355.
     Small Craft Advisory until 6 AM EDT Sunday for ANZ350-353-355.

&&

$$