discussion on 2023-10-23

000
FXUS61 KOKX 231103
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
703 AM EDT Mon Oct 23 2023

.SYNOPSIS...
High pressure builds in from the west today through tonight and
will start to move offshore Tuesday. High pressure continues to
build offshore Tuesday night through Wednesday night. High
pressure will remain offshore through the week. A weak cold
front approaches from the west by Saturday and moves through
Saturday night into Sunday morning.

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --Decreased clouds to better match with latest IR satellite
trends. Forecast overall remains on track.

Conditions remain dry today with more sun as high pressure
becomes a greater influence as it builds in from the Ohio
Valley.

For today, there will be high pressure building in from the
west. A weakening pressure gradient will lead to a less breezy
day. Winds will diminish towards early evening. Aloft, models
exhibit more ridging, and less cyclonic flow.

More sun and less clouds with less winds will lead to a
relatively warmer day than the previous day. Forecast highs
range more in the upper 50s to lower 60s.-- End Changed Discussion --

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
-- Changed Discussion --For tonight, high pressure moves overhead but with weak
shortwave aloft moving in and weakening ridging late, clouds
will increase. Winds however will continue to diminish and
become calm. Radiational cooling will occur but will not be the
most optimal with the clouds increasing late.

With some inconsistent trends over the last 24 hours, the low
temperature forecast has fluctuated as well as the frost
forecast for tonight. Much of the forecast lows are in the mid
30s to mid 40s. Forecast lows are in the upper 40s for NYC and
in the lower 30s for parts of Orange County. Cloud coverage has
exhibited a wide variance in the model forecast with some such
as the GFS, NAM and HRRR indicating mostly cloudy conditions
overnight into Tuesday morning.

Preference considering the uncertainty is to hold off on frost
advisory with this forecast package since confidence is lower on
this frost occurring. Still put in the forecast patchy and some
small areas of frost forming overnight, mainly across parts of
the interior to the north and west of NYC. Some locations with a
relatively higher chance to have frost formation include Orange
NY, Putnam NY, and parts of interior southern CT. Due to higher
cloud coverage, went more patchy with frost formation as opposed
to larger areas of frost. Overall confidence in frost low enough
to decide to hold off on issuing frost advisories.

Aloft, ridging resumes Tuesday. With mid level negative
vorticity advection behind the weak shortwave, clouds will
decrease. At the surface, high pressure will build more
southeast of the region. More SW winds develop in response. Warm
air advection is forecast. Went slightly higher than
MAV/MET/NBM combination with highs reaching more into the 60s.

The warming trend continues thereafter with lows Tuesday night
and Wednesday night getting relatively warmer than those of the
previous night. The daytime high temperatures forecast for
Wednesday were taken from the NBM which is leaning towards the
upper percentiles for the high temperature forecast, ranging
from the mid 60s to lower 70s. Low temperatures forecast Tuesday
night are in the mid 30s to low 50s and for Wednesday night are
in the low to upper 50s.-- End Changed Discussion --

.LONG TERM /THURSDAY THROUGH SUNDAY/...
Tranquil continues for Thursday onward as high pressure remains
offshore through the end of the week. With a continued southerly
flow, temperatures through the week are expected to be well above
normal.

Global guidance is coming into better agreement with a cold front
that is forecast to slowly approach the area from the mid-West on
Saturday. This front will move through Saturday night into Sunday
morning. However, the cold front looks to be week, and only light
amounts of rain are expected with it, with some solutions bringing
it through dry or mainly dry.

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
High pressure builds in from the west through today.

VFR. There is a low chance of high end MVFR ceilings at KSWF late
tonight.

A gusty NW flow continues until around 06Z, and then both sustained
winds and gusts gradually diminish. Gusts may become more occasional
after 04Z before ending 06Z to 09Z. Gusts may linger across the
metro terminals through 12Z. Winds become more northerly later this
afternoon. A light north to northeasterly flow develops tonight,
with the possibility of winds becoming light and variable
everywhere, but especially outside the metro terminals.

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

No unscheduled amendments expected. Gusts of around 20 kt may linger
to around 12Z.

OUTLOOK FOR 06Z TUESDAY THROUGH FRIDAY...

Tonight through Friday: VFR.

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

.MARINE...
-- Changed Discussion --SCA remains for the ocean waters this morning. The ocean SCA
remains in effect until 12PM this afternoon. Non-ocean waters
remain below SCA for this morning.

Conditions remain below SCA for this afternoon through
Wednesday night as the pressure gradient remains weak. High
pressure approaches the waters today into much of tonight and
eventually moves across the waters late tonight into early
Tuesday. The high then builds more offshore going into midweek.

Thereafter, with high pressure over the waters and a lack of a
pressure gradient, winds and seas are expected to remain below
SCA criteria through the beginning of the weekend.-- End Changed Discussion --

.HYDROLOGY...
No hydrologic impacts expected through the week.

.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until noon EDT today for ANZ350-353-355.-- End Changed Discussion --

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