147
FXUS61 KOKX 021739
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
139 PM EDT Tue Jul 2 2024
.SYNOPSIS...
High pressure builds across the area today, and offshore on
Wednesday. The high will then give way to an approaching weak
frontal system Wednesday Night into Thursday, which lingers
nearby into Friday. A warm front will approach Friday night and
lift through Saturday morning, followed by a cold front
Saturday afternoon and night. This front may linger nearby into
early next week.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Forecast remains on track with no significant changes to the
forecast.
Heights aloft build as shortwave energy moves east. At the
surface, high pressure overhead slides offshore late in the
day. Seasonable temps (lower to mid 80s) today with mostly sunny
skies (just a few high-based Cu and a bit of cirrus filtering
in late), deep mixing, and offshore flow giving way to afternoon
coastal sea breezes.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
Shortwave upper ridging thru Wednesday gradually flattens Wed Night
into Thu as a shortwave tracks through the Great Lakes and then
southern Canada. At the surface, high pressure slides offshore
Wed, with a weak frontal system approaching Wed Night into Thu.
Potential for a bit of radiational cooling (patchy fog) tonight
for outlying areas with light winds, with limiting factor being
cirrus advecting in aloft with a weak lead shortwave energy
over ridge.
Return flow strengthens Wed as high pressure moves offshore and
gradient tightens ahead of frontal system well to the west. Fair
conditions (sun may be filtered by high clouds) and moderately
strong hybrid synoptic/seabreeze development likely. This will
result in increasing humidity levels and near seasonable temps in
the upper 70s/lower 80s along the coast to mid 80s to the west of
the Hudson River.
Upper ridging flattens, with a weak frontal system approaching Wed
Night into Thu. Warm and muggy conditions Wed night in return flow.
Weak shortwave/vort energy moving through the upper flow may be
trigger for scattered shower development in vicinity of weak front
in a moist environment on Thu. Cloud cover, weak mid-level lapse
rates, weak instability/capping, and weak surface convergence point
to limited deep convection and thunder potential. Certainly not a
washout, but potential for a few showers, particularly aft/eve.
Otherwise, very warm and humid conditions with continued WAA (lower
80s coast to mid to upper 80s NYC metro and areas N&W).
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Forecast continues to follow the NBM for the most part, except temps
may be slightly warmer and dewpoints slightly less where latest
extended MOS guidance suggests. A quasi-zonal pattern that will be
in place to begin the period becomes more amplified, with a longwave
trough setting up over the Northern Plains and upper Midwest, and a
strengthening Western Atlantic ridge. As this occurs initially, the
frontal boundary that approaches during mid week should stall nearby
Thu night/Fri, then as a sfc low moves across the upper Great Lakes,
a leading warm front should approach Fri night and lift through on
Sat.
Temps through much of the period should remain similar, with highs
reaching the 80s to lower 90s, and lows mostly from the upper 60s to
mid 70s. Humidity levels will be highest on Sat, making it the least
comfortable day in terms of heat index values, which should approach
95 in spots in NE NJ on Fri and surpass 95 over most of the urban
corridor of NE NJ on Sat. Fcst temps that day are mot quite as warm
as the other days in the long term period, but a slight increase
(not out of the the question if there is more sunshine than
fcst) would bring 95+ heat index values to parts of NYC and
some areas north/west in the lower Hudson Valley.
With multiple frontal boundaries impacting the area through Sat
night and then the last of these lingering into early next week, the
forecast carries at least chance PoP for mainly diurnal convection
through the period, though forced nighttime convection may also
continue through Fri night into Sat AM ahead of the lifting
warm front.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
-- Changed Discussion --
VFR. Light onshore SE-SW winds 10kt or less through this evening.
Light and variable winds overnight. Winds pick up S-SW 10-15kt
Wed afternoon.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
No unscheduled AMD expected.
OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY...
18Z Wednesday: VFR. SE winds G20kt late.
Thursday: VFR for much of the day, then MVFR or lower cond
possible with any late day or nighttime showers/tstms.
Friday through Sunday: MVFR or lower cond possible at times
with chance of showers/tstms.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
High pressure builds across the area today with sub-SCA
conditions. Southerly flow strengthens a bit on Wednesday with
the high departing to the east and a weak frontal system
approaching from the west. Marginal SCA gusts possible Wed
aft/eve and Thu aft/eve at entrance to NY Harbor and western
Great South Bay with coastal jet development. Ocean seas may
approaching 5 ft in this area Thu. Sub advisory conditions for
the remainder of the waters.
Potential for minimal SCA conditions on the ocean E of Fire
Island Inlet this weekend, as long fetch S flow increases to 20
kt, with some gusts up to 25 kt and seas building to 5 ft.
&&
.HYDROLOGY...
A frontal system will approach Thursday into Friday, and
possibly linger into the weekend. Additional frontal boundaries
will affect the region into early next week. It is still too
soon to determine the risk of any hydrological impacts from
these multiple frontal boundaries affecting the area late this
week into early next week.
&&
.TIDES/COASTAL FLOODING...
There will be a generally low rip current risk today with 1 to 2 ft
S wind waves and SE swell, but could be locally moderate due to
large tidal range.
There will be a moderate risk for rip currents developing for the
NYC and western LI ocean beaches Wednesday aft/eve with late day
coastal jet and wind wave enhancement, with a low to moderate
risk for the Suffolk ocean beaches.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...BG/NV
NEAR TERM...BC/NV
SHORT TERM...NV
LONG TERM...BG
AVIATION...BG
MARINE...IRD
HYDROLOGY...BG/NV
TIDES/COASTAL FLOODING...