000
FXUS61 KOKX 211745
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
145 PM EDT Mon Aug 21 2023
.SYNOPSIS...
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A pre-frontal trough will remain along the coast this afternoon,
then followed by an early evening cold frontal passage. High
pressure will build in through mid week. A frontal system will
then impact the area Thursday night into Saturday, followed
by the return of high pressure on Sunday.-- End Changed Discussion --
&&
.NEAR TERM /THROUGH TONIGHT/...
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Minor adjustments were made with this update, mainly with cloud
cover, which may vary between partly and mostly sunny.
A pre-frontal trough will remain along the coast this afternoon
with a W/NW flow, except SW along portions of the coast due to
a seabreeze influence. A cold front lagging behind will hold off
until early this evening, bringing isolated to widely sct
showers to parts of the Hudson Valley, S CT, and ern Long
Island. SPC has those areas in a general thunder outlook but
instability on fcst soundings looks too meager for thunder
mention.
Temps today should reach 90 in most of NYC and NE NJ, and reach
the mid and upper 80s elsewhere. Combined with afternoon
dewpoints in the mid 60s, heat index values should stay close
to actual temps.
As the cold front moves through this evening, winds should shift
N and increase to 10-15 mph, highest in the metro areas and
along the coast. Lows tonight should be mostly in the 60s,
perhaps some upper 50s in the interior valleys.-- End Changed Discussion --
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
High pressure will gradually build from the NW through the
period, with comfortable temps/humidity, with highs both days
75-80. Lows Tue night under mostly clear skies and light winds
should range from 60-65 in/near NYC, to the 50s elsewhere,
getting as low as 50 in the Long Island Pine Barrens region and
in some interior valley spots.
Skies should be mostly clear through much of the period. Mid
level clouds could be on the increase from NYC west Wed
afternoon as a mid level vort max well in advance of a sfc warm
front over the Midwest approaches in NW flow aloft.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
High pressure remains in place on Thursday, keeping us dry.
However, clouds will begin to increase as it pushes east and
loses its influence into the day on Friday. High temperatures
will reach the mid/upper 70s on Thu, and upper 70s/lower 80s on
Fri.
A frontal system will impact us Friday into Saturday with an
upper level trough remaining in place through the weekend.
Ahead of the system, southerly winds pick up, helping advect
higher dewpoints into the region. The 00Z GFS provides PW around
2.15" across a large portion of the area that is expected to
pass through Friday night/Saturday morning. The ECMWF has the
front a little earlier on Thursday night into Friday morning
and is also showing PW signals topping off around 2.10". SPC`s
sounding climatology page show a max moving average of 2.04"
during this timeframe. Worth keeping an eye on to see how it
trends closer towards the near term. It`s also worth noting that
timing and placement of the front and PoP may still change as
the 00Z GFS and 00Z ECMWF, as well as other guidance, still
vary.
&&
.AVIATION /17Z MONDAY THROUGH FRIDAY/...
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A weak cold front passes through this afternoon into the early
evening.
VFR. Slight chance of -shra this afternoon into the early
evening hours mainly north and east of NYC terminals, but they
are too low to include in most TAFs except KGON.
W to WNW winds around 5 to 10 kt increase to around 10 kt this
afternoon. The cold front is expected to move through mid to
late afternoon, with a 22Z to 00Z timeframe for the metro
terminals. Gusts of 15 to 20 kt are expected, but may be more
occasional and/or for a shorter time than is forecast. A few
higher gusts are possible along the immediate coast.
There is the potential for seabreezes to move through KJFK,
KISP, KBDR, and KGON. However, there is some uncertainty with
timing and wind direction, with the highest uncertainty for
KISP, where a TEMPO was added to reflect the uncertainty and
potential for the sea breeze to stall just south of the
terminal.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Gusts may be more occasional for a couple of hours behind the
cold front passage in the late afternoon on Monday.
There is uncertainty with wind direction at coastal terminals
given the strength and resiliency of offshore gradient. Best
chance would be KJFK, KBDR and KGON. There is a very low chance
that it moves through KLGA, but at this time, it is not
expected.
OUTLOOK FOR 18Z TUESDAY THROUGH SATURDAY...
Tuesday through Thursday: VFR.
Friday: Chance of shwrs and tstms. MVFR or lower possible at
times.
Saturday: VFR.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
After a cold frontal passage this evening, a brief period of
marginal SCA conds may be possible on the outer ocean waters S
of Montauk, with ocnl gusts up to 25 kt and sea possibly nearing
5 ft Tue AM. Due to the marginal nature and limited coverage of
these conditions, have not issued SCA.
Marginal SCA cond may be possible late Thu night into Fri on the
ocean waters, as S flow ahead of an approaching frontal system
increases to 15-20 kt with a few gusts up to 25 kt.
&&
.HYDROLOGY...
A frontal system will bring showers and some thunderstorms Friday
into Saturday, with some concerns for isolated heavier
rainfall.
&&
.TIDES/COASTAL FLOODING...
A low rip current risk continues for today and Tuesday.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
UPDATE...DW
AVIATION...IRD