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000
FXUS61 KOKX 251139
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
739 AM EDT Sun Oct 25 2020

.SYNOPSIS...
High pressure over New England starts the period. A
surface low pressure system passes well to the south Sunday night,
and then east of the area on Monday followed by another cold front
approaching on Tuesday. A Mid Atlantic ridge settles in to the south
through mid week while a weak shortwave trough passes east into
Quebec to the north. A frontal system arrives into the Northeast
late in the week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
The forecast is on track this morning with only minor
adjustments made to account for current observational trends.
Temperatures have stayed up at many locations with winds slow to
diminish, while dewpoints have dropped in the low to mid 30s
across the board.

The day starts out dry, as the cold front that
passed through the area Saturday has stalled well to the
southeast. Northwest winds are beginning to diminish as the
pressure gradient has relaxed and a 1028mb surface high settles
in across New England. Ridging is building to the south along
its eastern periphery, and extending into the area, allowing for
some mid level dry air to remain in place over the CWA.

At the same time, GOES-16 6.19um water vapor channel depicts
shortwave energy currently moving across GA/SC, with high level
moisture streaming to the northeast. High clouds are already
filtering into the area in advance of this system from the
southwest. A surface low is also developing near the SC/NC
border in association with the shortwave. Deep southwest flow
aloft will continue to advect moisture north through the day on
Sunday as the shortwave and surface low head northeast along the
stalled front. Model soundings/time heights indicate that cloud
cover will increase and lower into Sunday evening. Light
precipitation should begin later Sunday afternoon as the
southerly moisture advection erodes the mid level dry air. The
question is how long does that take. Current thinking is
precipitation onset across the southwestern sections of the CWA
near 18Z-21Z, which is broadly supported by the most recent
global models. Hi-res models are trending a few hours earlier
into northeast NJ. Precipitation with this event should remain
light overall, as best synoptic forcing remains well to the
north and there is some mid level dry air locally to overcome at
the onset. 00Z models are in better agreement tonight on the
evolution of this event with respect to track of the surface
low and associated precp shield impacting the area. Have trended
PoPs up just a bit, particularly for 23Z-00Z period to likely
across most of the CWA, but still below NBM PoPs, which are a
hair higher.

High temperatures will be cool on Sunday, in the low to mid
50s, with a combination of the cool airmass in place to start,
then tempered by increased cloud cover later in the day.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
Precipitation continues into Sunday evening and spreads north and
east across the area, as the surface low passes well south of LI and
heads northeast by Monday morning. Any lingering precipitation ends
on Monday morning as the low pulls away. Precipitation totals
of around 0.1-0.25 inches are expected areawide, with the
highest amounts in northeastern NJ. The steadiest period for
precipitation to occur is the period between about 06Z and 12Z
Monday morning, but again, expecting it to be on the light side.

Cloud cover will remain in place through much of the rest of Monday
into Monday evening however, as another cold front approaches from
the west. Easterly flow at the surface for much of the day Monday
will keep cloud cover and drizzle potential in place into the
afternoon, and have that reflected in the latest NDFD grids.
Temperatures will be be a few degrees warmer than on Sunday, in the
upper 50s to lower 60s, but still cool given the plentiful cloud
cover and precipitation.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
The synoptic scale trough aloft with southwest flow overhead
continues to bring moisture in from the southern states through
midweek. Short wave impulses along this trough combined with the
elevated precipitable water values around 1.10 to 1.30 inches
make for light rain chances on both Tuesday and Wednesday.

The weather pattern become quite active late Wednesday into
Thursday. A jet enhanced frontal system over the Great Lakes enters
northern New York Thursday. At the same time tropical moisture from
TS Zeta is advected into southern New York as noted by the
1.75-2.00 inch PWATs. As these two systems meet expect
widespread moderate to heavy rainfall throughout the East Coast
lingering into Friday. The upper level trough then shifts east
and offshore as we head into the weekend. Models show a 1030mb
high pressure system building in behind with dew points in the
30s meaning an environmental regime change is possible next
weekend.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
High pressure builds over the area from the northwest through
this morning. A surface trough and warm front along the mid
Atlantic coast approaches from the south late this afternoon.

VFR through the rest of tonight and this morning. MVFR ceilings
may develop between 00-03Z Monday at all terminals.

NE winds today, shifting more toward the E this afternoon and
evening. Wind speeds will be 10-15 kt for coastal terminals, 10
kt or less for terminals away from the coast.

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

No unscheduled amendments expected. Amendments are possible
toward 00Z Monday as ceilings begin to lower.


.OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY...
.Monday...MVFR or lower conditions and -RA.
.Tuesday...MVFR possible with a chance of showers.
.Wednesday-Thursday...MVFR or lower possible in chance of -RA.

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

&&

.MARINE...
Seas on the ocean waters will diminish somewhat today, and may
briefly fall below 5 ft late this afternoon into early evening as
swells from departing Epsilon no longer affect the waters. Waves
build again tonight in response to strengthening easterly flow ahead
of the an approaching low pressure system that is forecast to pass
south of the waters. Waves increase to 5 to 7 ft tonight into Monday
morning, slowly diminishing through the afternoon. With 5+ ft waves
expected through the day Monday, the SCA was extended in time to 6
pm Monday.

Winds will remain below 25 kt Sunday with high pressure over the
waters retreating into southern Canada. Winds increase tonight and
may touch 25 kt at times on the ocean waters late tonight into early
Monday morning. Elsewhere, winds should remain below 25 kt.

Waves then range mainly from 3-4 feet over the ocean with light east
to northeast winds through Wednesday. Late Wednesday southwest winds
develop as the remnants of Depression 28 enter the marine zones. SCA
criteria is possible Friday as waves of 6-7 feet with wind gusts of
25 kts over the ocean waters owing to the system making its closest
approach.

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

&&

.HYDROLOGY...
No hydrologic concerns through Wednesday. Heavy rain is
possible Thursday with the arrival of tropical moisture.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 PM EDT Monday for ANZ350-353-355.

&&

$$
SYNOPSIS...DJ/DBR
NEAR TERM...DBR
SHORT TERM...DBR
LONG TERM...DJ/DBR
AVIATION...JP
MARINE...DJ/JP
HYDROLOGY...DJ/DBR