000
FXUS61 KOKX 211956
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
356 PM EDT Mon Aug 21 2023
.SYNOPSIS...
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A cold front will pass through the area this evening, followed
by high pressure building in from the northwest through Wednesday.
A frontal system will then impact the area Thursday night into
Friday. Behind this, high pressure gradually builds in from the
Great Lakes this weekend.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
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A cold front will work across the area early this evening with
perhaps an isolated shower, mainly across CT and eastern LI.
While MUCAPES inland are 500-1000 J/KG, there is limited
moisture and this is reflected by much lower MLCAPE values. In
fact, the best moisture flux convergence is along the coast
where there is a weak trough lingering and some hybrid seabreeze
influence. Regardless, any isolated shower will be brief with
little fanfare.
More importantly, the upper trough across the NE will amplify
the next 24-36h, sending in a cooler, drier airmass.
Temperatures will be several degrees below normal after tonight
through midweek. Northerly winds behind the cold front will
ramp up late with gusts up to 20 mph.
Lows by daybreak will range from around 60 inland, to the mid
and upper 60s along the coast. This is right around normal.-- End Changed Discussion --
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
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Dry, cool conditions will prevail for late August with daytime
highs both Tue and Wed struggling to get to 80, with nighttime
lows from the lower/mid 50s inland, to around 60 at the coast
(cooler across Pine Barren region of LI).
The upper trough will dig along the New England coast through
Tuesday night as surface high pressure builds in from the Great
Lakes. Northerly winds may gusts up to 20 mph for the first half
of Tuesday before diminishing with the approach of the high.
The high settles over the are Wednesday with a weak return flow
and seabreezes in the afternoon.-- End Changed Discussion --
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
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Surface high pressure slides offshore to start the period, with
return southerly flow setting up on Thursday. Meanwhile, a sprawling
H500 ridge situated over the Central US retrogrades into the
Southern Plains mid to late week, allowing a northern branch
shortwave to slide southeast out of Canada and toward the region.
This will send a frontal system through late Thursday through Friday,
before high pressure returns once again this weekend.
Dew pts climb with the return flow, and forecast PWATs rise to near
2 inches by late Thursday. Rain chances increase along with it as a
warm front approaches from the south and west. While this doesn`t
appear to be a washout, scattered showers are possible by the
evening hours, with chances lingering overnight into Friday. The
high available moisture will at least allow for the possibility of
heavy downpours. Trimmed PoPs just a bit with inherent uncertainty
in timing at this point, but still maintained likelies (~60%) for a
period Thu night into Friday morning. The surface low likely passes
to the north across New England on Friday, with an attendant cold
front sweeping through late in the day. Depending on the timing and
position of these surface features, there may be enough
destabilization Friday to allow for additional showers and a few
thunderstorms ahead of the fropa, but severe threat looks limited at
this point. The front clears east of the region by Saturday, with
high pressure sinking south through the Great Lakes. This should
allow largely dry, seasonable conditions for the final weekend of
August. Other than already noted, followed the national blend of
models for this update.-- End Changed Discussion --
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
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A weak cold front passes through this evening.
VFR. Very slight chance of -shra this afternoon early evening hours
well north and east of NYC terminals, but they are too low to
include in the TAFs except for KGON. The cold front is expected to
move through with a 22Z to 00Z timeframe for the metro terminals.
NW Winds 10-15 kt this evening becoming N tonight behind the front.
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. Its important to note sea breeze
development has struggled this afternoon due to stronger than
expected NW gradient flow. The exception has been KBDR where a
localized SW wind has been occurring. It`s not out of the question
local sea breezes meander a few hours this evening. This is
especially true for KBDR/KISP/KGON and across Long Island where for
KISP, the sea breeze remains just south of the terminal but within
5km of the airport. For this reason a TEMPO group remains.
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 remains uncertainty with wind direction at coastal terminals
given the strength and resiliency of offshore gradient.
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...
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After a cold frontal passage this evening, northerly winds will
increasing to 15 to 20 kt, but forecast to remain below SCA
criteria. Seas on the ocean will increase to 3 to 4 ft overnight
into Tuesday morning. Thereafter, winds and seas will diminish
with high pressure building across the waters into Wednesday.
Increasing southerly flow ahead of a frontal system may produce
gusts around 25 kt on the ocean waters Thursday evening through
Friday. Ocean seas build to around 5 ft during this time in
response, and may remain elevated into early Saturday.
Thereafter, sub SCA conditions expected through the weekend on all
waters.-- End Changed Discussion --
&&
.HYDROLOGY...
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A frontal system will bring showers and a few thunderstorms to the
region late Thursday through Friday evening. Locally heavy downpours
are possible, and this could lead to nuisance flooding of urban and
poor drainage areas.-- End Changed Discussion --
&&
.TIDES/COASTAL FLOODING...
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A low rip current risk continues for all Atlantic-facing beaches
Tuesday and Wednesday with surf height under 2 ft.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...DR/DW
NEAR TERM...DW
SHORT TERM...DW
LONG TERM...DR
AVIATION...IRD
MARINE...DR/DW
HYDROLOGY...DR/DW
TIDES/COASTAL FLOODING...DR