138
FXUS61 KOKX 131809
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
209 PM EDT Tue Aug 13 2024
.SYNOPSIS...
A series of weak surface troughs will move across the area
through Thursday. Weak high pressure will otherwise remain in
control through the end of the week. A weak frontal system
will slowly approach from the west from Friday night into
Monday.
&&
.NEAR TERM /THROUGH TONIGHT/...
Forecast on track with only minor adjustments to temperatures
and dew points to reflect the most recent observations and
trends of each into the afternoon.
The upper trough that moved through Monday evening will
continue pushing off the New England coast today. Broader
troughing will remain aloft over the northeast with high
pressure continuing to nose in from the west. There are no
organized shortwaves or areas of forcing compared to Monday, so
the forecast remains dry. Forecast soundings indicate fairly
deep mixing up to 4-6 kft. There is a thin layer of moisture at
the top of the mixed layer which should yield scattered clouds
in the afternoon. CAMs are simulating some light returns in the
simulated reflectivity fields, which may be more of a signal of
the cloud field rather than actual showers. Do not think there
will be measurable precip given the shallow moisture, shallow
instability, subsidence, and dry subcloud layer. However, a
sprinkle cannot be ruled out. Otherwise, highs will once again
be a few degrees below normal in the upper 70s and lower 80s.
Tonight will feature mostly clear skies with seasonably cool
temperatures in the upper 50s inland and lower to middle 60s
elsewhere.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
The broad upper trough will remain anchored over the region, but
there will likely be some retrogression of an upper low within
the trough Wednesday into Wednesday night. The models are
indicating the upper low will move from near the Maritimes
southwest towards Maine. The sensible weather over the Tri-State
should not change much, but there will likely more organized
shortwave energy rotating around the upper low, which may aid in
the development of a few showers for inland areas of the Lower
Hudson Valley and Connecticut Wednesday afternoon. Instability
still looks weak/shallow and have left mention of thunder out
of the forecast for now. Temperatures will moderate compared to
recent days with highs in the low to middle 80s across the
region, slightly above normal for this time of year.
Another round of shortwave energy aloft dives southward around
the upper low, which only slowly shifts east, late Thursday
into Thursday night. High pressure will remain just to the west
with the likelihood of a weak surface trough over the area on
Thursday afternoon/evening. Forcing and instability look to
maximize across eastern CT Thursday afternoon and evening,
supporting a bit higher probabilities (chance) for showers and
thunderstorms. Otherwise, isolated convection is possible
westward into the Lower Hudson Valley. Have left PoPs below 15
percent towards the coast and NYC for now as sea breezes may
stabilize the low levels to prevent convection from making it
that far south. Highs look seasonably warm in the lower to
middle 80s.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
Wx on Friday should be dry as shortwave ridging aloft slides
across. Then chances for showers/tstms increase going into the
weekend and early next week as a longer wave upper trough and
associated sfc frontal system approach. Its forward motion will
be slowed down by downstream ridging and also the passage of
Ernesto to the east on Sunday.
The frontal system may start to make some forward progress on
Monday, but still have chance PoP in the forecast as additional
shortwave energy drops into the longwave trough and keeps it
anchored in place to the west.
Temps on Fri and Mon should be slightly above normal, with near
normal temps this weekend.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
-- Changed Discussion --
A surface trough will linger over the area today. There could
be some sct-bkn mid level clouds at times this afternoon, with
flight cat remaining VFR.
NW flow around 5-10 kt gusting to 15-20 kt during the afternoon.
Winds become light out of the NW this evening then shift around
to the North late tonight and remain northerly through
Wednesday.
A late sea breeze attempts to develop this afternoon along
the immediate coast, and push northward to KLGA this evening.
Seabreezes likely to develop once again on Wednesday.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Low confidence on sea breeze timing at KJFK this afternoon. A
light SE-S sea breeze may make it to KLGA this evening.
OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY...
Wednesday through Friday: VFR.
Saturday through Sunday: Chance of showers with MVFR cond
possible.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
High pressure provides a weak pressure gradient and a light wind
regime overall through Thursday night. Seas will also remain well
below SCA levels.
The combination of an approaching frontal system Fri night into the
weekend along with building long period swells from Ernesto will
allow for ocean seas to build rapidly to SCA levels, going from 2 ft
late Fri afternoon to 5-6 ft by daybreak Sat, with some sets as high
as 7 ft Sat afternoon.
&&
.HYDROLOGY...
There are no hydrologic concerns through the end of the week.
It is too early to know what, if any, impacts may arise from an
approaching frontal system this weekend.
&&
.TIDES/COASTAL FLOODING...
There is a low rip current risk through Wednesday.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...BG/DS
NEAR TERM...DS/MW
SHORT TERM...DS
LONG TERM...BG
AVIATION...20
MARINE...BG/DS
HYDROLOGY...BG/DS
TIDES/COASTAL FLOODING...