000
FXUS61 KOKX 221420
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1020 AM EDT Sun Oct 22 2023

.SYNOPSIS...
Strong low pressure in the Canadian Maritimes will gradually
move farther east into the Northern Atlantic today through
tonight and into early week. Meanwhile, across the local region
high pressure starts to build in from the west late tonight and
will continue to build in through early week. High pressure
will remain through the week. A weakening cold front should
approach from the west by Saturday.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Minor adjustments were made to account for current
observations. Otherwise, the forecast remains on track for
today.

Steep pressure gradient remains between low pressure northeast
of the region in the Canadian Maritimes and high pressure to the
west near the Western half of the Great Lakes. This will keep a
gusty westerly flow through the day although at less magnitude
than the previous day and night.

In the mid levels, a mid level vorticity maximum approaches and
eventually moves across during the evening hours. The associated
cyclonic flow aloft will make for increasing clouds today, with
mostly cloudy conditions expected this afternoon into tonight.
At the surface, a trough moves across at night, making for more
northerly component to the wind.

Daytime high temperatures forecast remain below normal, ranging
from the low to upper 50s, several degrees below normal.

Models indicate some light rain showers that may traverse
mainly northern portions of the region late in the afternoon
into the early evening but there will not be much moisture
available with the NW profile of wind through the troposphere.
POPs are only slight chance. CAMs vary in their depiction of
these showers as shown by discrete areas of higher reflectivity
traversing the region from north to south.

The pressure gradient weakens tonight with the low moving
farther away from the local region and the high pressure area to
the west getting closer. Less cyclonic flow is expected by late
tonight into early Monday, allowing for clouds to decrease.
With the winds staying up though, radiational cooling will be
mitigated. Forecast lows range from the low to upper 40s.
-- End Changed Discussion --

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
For Monday, high pressure will be more of an influence in the
region with greater subsidence and a further decrease of the
pressure gradient. Less gusty winds and more sun will lead to a
relatively warmer day. Forecast high temperatures are more in
the upper 50s to lower 60s, which will be closer to normal for
this time of year.

For Monday night, while surface high pressure builds overhead,
models depict a weak shortwave moving in at night. Models are
also indicating an increase in clouds during the night as well.
What once appeared as an optimal radiational cooling night is
now appearing more sub-optimal with the clouds mitigating some
of the radiational cooling. Took a blend of MOS and did not take
the coldest of the MOS because of this. Forecast lows still
range mainly in the mid 30s to upper 40s. Forecast lows still
have outlying areas and interior locations in the lower 30s.
Frost with low level saturation is forecast for north and west
of NYC and parts of the Pine Barrens but confidence is not high.
Parts of the Lower Hudson Valley have forecast temperatures
near freezing.

For Tuesday and Tuesday night, the airmass transitions to a
warmer airmass. More SW low level flow gets established. Models
indicate the shortwave trough to move southeast of the area with
more mid level negative vorticity advection and ridging aloft.
This will allow for less clouds. Forecast highs Tuesday get more
into the 60s with lows Tuesday night ranging from the low 40s
to low 50s. Expect some radiational cooling Tuesday night but
warmer temperatures are advecting aloft at 850mb, so low
temperatures will be limited by this as well as onshore surface
flow along the coast.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Tranquil weather expected from Wednesday onward as high pressure
remains offshore through midweek. Several dry days with sun can be
expected. With a continued southerly flow, temperatures through the
week are expected to be above normal.

Global guidance is not in as good agreement for next weekend. A cold
front is expected to slowly approach the area at the end of the week
into the beginning of next weekend. The GFS bring the front through
late Saturday into Saturday night, while the ECMWF and Canadian keep
the front to our north and west as it dissipates. However, in either
solution, it will remain generally dry, as the GFS frontal passage
is dry.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
Deep low pressure tracks slowly through the Maritimes today,
gradually weakening this afternoon. Meanwhile, high pressure
builds toward the region from the west.

Mainly VFR. MVFR CIGs possible at times KSWF and possibly KHPN.

Winds remain from the W to NW and gusty through the forecast.
Winds and gust gradually through daybreak. Some metro terminals
are SW, but they should shift more to the west early this
morning. Winds and gusts increase through the morning, becoming
more NW, around 310 magnetic. Winds and gusts diminish this
this evening. Gusts end around 09Z Monday, but may end a few
hours earlier for the outlying terminals and a few hours later
for the metro terminals.

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

Timing of winds becoming more NW, around 310 magnetic may be earlier
than forecast this afternoon.

No amendments expected.

OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY...

Monday: VFR. Gusty NW flow 15-20 kt in the morning.

Tuesday through Thursday: VFR.


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

&&

.MARINE...
Small craft advisory goes through tonight for all forecast
waters, ending at 6am Monday. Unsure exactly when within first
half of Monday, conditions drop below SCA thresholds.

SCA wind gusts will probably remain for most waters early
Monday, especially the ocean but by mid to late afternoon, would
expect all wind gusts to remain below SCA thresholds.

SCA seas expected to drop below SCA thresholds by late today for
the Long Island Sound but for the ocean, seas stay in SCA range
through tonight. SCA seas forecast to remain for part of the
ocean zones Monday morning with all marine zone seas below SCA for
Monday afternoon.

Below SCA conditions are forecast to remain in place Monday
night through Tuesday night with a weak pressure gradient in
place.

With high pressure over the waters and a lack of a pressure
gradient, winds and seas are expected to remain below SCA criteria
through end of the week.

&&

.HYDROLOGY...
Any rain showers through this evening expected to produce less
than a quarter of an inch of rain.

No hydrologic impacts expected through the week.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 AM EDT Monday for ANZ331-332-335-
     338-340-345-350-353-355.

&&

$$

SYNOPSIS...JM/JP
NEAR TERM...JM/BR
SHORT TERM...JM
LONG TERM...JP
AVIATION...JMC/JP
MARINE...JM/JP
HYDROLOGY...JM/JP