000
FXUS61 KOKX 231731
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
131 PM EDT Sun Jul 23 2023
.SYNOPSIS...
Weak high pressure remains in place today. A weak low pressure
system may pass nearby to the south Monday night into Tuesday.
Weak high pressure remains in control through late next week. A
frontal system may impact the region next weekend.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Isolated showers and thunderstorms have developed across the
higher terrain of northeastern Pennsylvania and into
northwestern New Jersey with weak surface convergence and
surface based instability and CAPE of 500 to just over 1000
J/kg. CAMs have developed the convection, and bring weakening
storms into the region this afternoon into early this evening.
Updated to add slight chance probabilities and used coverage
wording. Otherwise updated for the current conditions. Mixing of
some lower dew points aloft was occurring once again today,
though they are not expected to be as low as yesterday. Highs
will once again be seasonable.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
Broad upper trough remains in place across the eastern US
through Tuesday night, though gradually flattening through the
period. A weak shortwave trough approaches Monday afternoon into
early Monday night. Some showers and thunderstorms are possible
with this feature, bringing just a slight chance for portions
of New York City, but the best chances remain north and west of
the city. The shortwave is expected to weaken as it heads east,
so do not expect precipitation to head much farther east than
the Hudson River.
The ECMWF continues to develop a weak low pressure along an old
frontal boundary Monday night. Bring in some slight chance POPs
across mainly Long Island for this possibility, though there is
a great deal of uncertainty with this feature as other models
are much weaker or much less organized.
Temperatures continue to be seasonable through the period.
Humidity levels increase to more typical levels as well.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Surface high pressure over the Atlantic builds over the East Coast
mid to late week, resulting in fairly quiet weather with increasing
temperatures. A frontal system may impact the area by the weekend,
bringing a return to rain chances, and helping to break the heat.
Heights climb on Wed as ridging aloft builds. This should keep the
region warm and dry through the day, with highs in the upper 80s to
lower 90s. By late week, ensemble means prog 850mb temperatures
around 20C, which should mix down into the upper 80s and 90s at the
surface away from the immediate coastline. NBM v4.1 probabilities of
90F have increased, now exceeding 95% for the urban metro both Thu
and Fri, with a low non zero chance of 100F (~10%). Coupled with a
moist SW flow, dew points rise into the low to mid 70s, apparent Ts
likely reach the mid 90s both days, with some areas topping 100F at
times. Should this hold, it would bring us to our first heat
headlines of the season, though still some time to fine tune these
details.
The ridge may start to get suppressed into the weekend as a trough
attempts to drop south out of Canada. Still condisderable
disagreement amongst the globals at this stage, but rain chances
increase ahead of a potential leading frontal system by Sat.
Followed the national blend of models for this update, with subtle
adjustments.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
-- Changed Discussion --
Weak high pressure remains over the region today then slides
offshore tonight.
Generally looking at VFR conditions through the TAF period. A few
isolated showers have developed over eastern PA and should weaken as
they approach the local terminals. Have opted to leave the forecast
dry this afternoon, however can not rule out an isolated shower,
mainly across KEWR/KTEB and points west. A slightly better chance
for showers/thunderstorms is expected Monday afternoon. Have
included a PROB30 for TSRA at KSWF for the afternoon, however with
slightly less confidence further east, have not included PROB30s
anywhere else.
Winds are generally light early this afternoon with with sea breeze
developing at the coastal terminals. Speeds will increase to around
10 kt by mid afternoon. Winds lighten this evening, going SW
overnight, before becoming southerly once again Monday afternoon.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of wind shifts with seabreeze development may vary by 1-2
hours and could be variable at times.
Can not rule out an isolated showers, especially at KEWR and KTEB
both today and Monday afternoon.
OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
Monday afternoon and Tuesday: VFR. A slight chance of a late
day showers/tstms at the NYC metro terminals and northwest.
Wednesday through Thursday: Mainly VFR.
Friday: Mainly VFR, A slight chance of an afternoon thunderstorm.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
A Marine Weather Statement remains in effect for Long Island
Sound. The National Weather Service in coordination with the
United States Coast Guard have received reports of a large
debris field across Long Island Sound, caused by recent flooding
across New England.
Made minor changes to the winds, especially across the ocean
waters, which are a few knots higher than was forecast.
Otherwise, no changes were made to seas/waves.
Sub-SCA conditions are expected with a weak pressure gradient
over the area through at least Thursday. Increasing winds and
seas on Friday may produce SCA conds on ocean waters.
&&
.HYDROLOGY...
No significant widespread rainfall is expected through mid week next
week.
&&
.TIDES/COASTAL FLOODING...
There is a low rip current risk for today with weak flow and
seas less than 3 ft. The rip current risk for Monday is moderate
as the surf height increases to around 3 ft and a stronger flow
is expected.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JP/DR
NEAR TERM...JP/MET
SHORT TERM...JP
LONG TERM...DR
AVIATION...BC
MARINE...JP/DR/MET
HYDROLOGY...JP/DR
TIDES/COASTAL FLOODING...