000
FXUS61 KOKX 211323
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
923 AM EDT Mon Aug 21 2023
.SYNOPSIS...
A pre-frontal trough will move over the area today as high
pressure weakens over the Atlantic. A cold front will move
through this evening, followed by high pressure from Tuesday
through Thursday. A frontal system will impact the area Friday
into Saturday. High pressure will return on Sunday.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Minor adjustments were made with this update. Plenty of high
level cloud cover, so have bumped that up a bit as well. Have
held on to highs, but these may need some adjustment depending
on the extent of the cloud cover.
A pre-frontal trough will move through today, with light W flow
shifting NW by afternoon. A cold front lagging behind will hold
off until late day and 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 /14Z MONDAY THROUGH FRIDAY/...
A weak cold front passes through this afternoon into the early
evening.
VFR. Slight chance of shra/tstm this afternoon into the early
evening hours, 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.
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 KJFK with the
possibility of a seabreeze moving through around 17Z. There is
a very low chance that it moves through KLGA, but at this time,
it is not expected.
OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY...
Tuesday through Thursday: VFR.
Friday: Chance of shwrs and tstms. MVFR or lower possible at
times.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90
&&
.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.
&&
$$
SYNOPSIS...BG/BR
NEAR TERM...BG/DW
SHORT TERM...BG
LONG TERM...BR
AVIATION...JP
MARINE...BR
HYDROLOGY...BG/BR
TIDES/COASTAL FLOODING...