000
FXUS61 KOKX 261139
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
739 AM EDT Wed Jul 26 2023
.SYNOPSIS...
High pressure will remain offshore this week, bringing heat and
humidity into the area from Thursday into Saturday. An upper
level disturbance will pass through late Thursday into Thursday
evening bringing potential severe weather. A cold frontal
passage is expected on Saturday, with Canadian high pressure
building in its wake for Sunday and remaining to the west into
early next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
As high clouds exit to the east, low clouds and fog remain in
place mostly NW of the NYC metro urban corridor. These should
burn off fairly quickly after sunrise, with mostly sunny skies
expected, just some sct afternoon Cut mainly from NYC
north/west.
Temps are running on the high side of the guidance, so have fcst
upper 80s and lower 90s across the area, hottest over urban NE
NJ. Can`t totally rule out the heat index briefly touching 95
at or near EWR, otherwise heat index values should remain close
to or only a little higher than actual temps, and below 95.
Some lead energy well in advance of an upper trough crossing the
Great Lakes may bring some mid level clouds into the region late
tonight. Some patchy low clouds and fog may also be possible
late but have not yet included these in the forecast. Low temps
tonight should be mostly in the 70s.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
Have replaced the heat advisory with an excessive heat
watch for most of NE NJ, and expanded the heat advisory to
include coastal SE CT and the south fork of Long Island. Both
hazards now run into early Friday evening.
Heat and humidity should ramp up quickly on Thu in SW flow
between the approaching shortwave and strong western Atlantic
ridging, with temps both days reaching the upper 90s to near
100 in urban NE NJ, and the lower/mid 90s elsewhere. Dewpoints
in the lower 70s to start each morning should decrease slightly
to the upper 60s from NYC north/west, but remain steady
elsewhere or even increase to the mid 70s along the coast. This
will yield max heat index values of just over 105 in the watch
area, 100-104 in most other urban areas and the valleys of
Orange County, and 95-100 elsewhere.
SW flow will become quite breezy along the south shore of Long
Island, with gusts to 30 mph likely in the afternoon.
Line of tstms with the approaching shortwave trough should
arrive during the late afternoon and evening hours. SPC has
placed the entire region in a slight risk for severe tstms, with
the main threat damaging wind, and the CSU-MLP 00Z Day 2
forecast shows even higher probabilities of damaging wind from
NYC north/west, centered over the lower Hudson Valley.
If the timing is earlier than fcst this may allow enough
convective debris clouds to overspread parts of the area and
dampen temps and heat index values by a few degrees.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Conditions will continue to be warm overnight Friday, with lows
in the 70s once again region-wide and although Saturday will be
hot again, it will be a few degrees cooler thanks to increasing
clouds due to an approaching cold front. Highs will range from
the upper 80s to lower 90s. Heat advisories may need to be
extended into Saturday as heat index values across much of Long
Island, NYC, NE NJ, and southern Connecticut will be in the
95-100 range.
Models are in fairly good agreement with the timing of the cold
front passage Saturday into Saturday evening, pushing offshore
by early Saturday night. However, there will still be some
timing differences in where and when showers and thunderstorms
will develop.
Thereafter, Canadian high pressure builds in at the surface for
Sunday and remains west of the area through Tuesday night.
Aloft, a trough will be in place for the Northeast and into the
Mid- Atlantic while a ridge builds over the Plains and Rockies.
This will introduce a cooler and drier airmass into the region
for Sunday onward. Highs are expected to be a couple of degrees
below normal while dew points drop into the 50s (possibly even
into the upper 40s if enough mixing and drier air move into NW
portions of the forecast area). Dew points may rise into the
lower to middle 60s by Tuesday afternoon.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
High pressure remains offshore.
Except for some patchy MVFR or lower fog/stratus for some
terminals outside of NYC into early this morning, mainly VFR
conditions are expected to prevail through the TAF period.
Another round of MVFR or lower fog/stratus is possible tonight,
again mainly outside the metro terminals, but there is a low
chance it may make its way even into these terminals.
Winds will be more S to SW around 10 kt for most terminals this
morning into the afternoon. Sea breezes look to shift winds
more to the SE for KTEB and KEWR. Winds diminish after sunset.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Occasional gusts between 15-20 kt possible this afternoon.
OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY...
Thursday: Possible showers and thunderstorms at times late afternoon
into evening with brief MVFR to IFR possible. Higher chances of
showers and thunderstorms near KSWF. If tstms develop, they
could become severe. Otherwise, VFR. SW wind gusts along coast
around 20 kt in the afternoon into evening.
Friday: Possible showers and thunderstorms at times afternoon
into evening with brief MVFR to IFR possible to the north and
west of NYC. Otherwise, VFR.
Saturday: Chance of showers and thunderstorms with MVFR to IFR
possible at times. Otherwise, VFR.
Sunday: VFR.
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 continues for Long Island Sound. The
US Coast Guard still indicates a large debris field caused by
recent flooding across New England.
Sub-SCA criteria is expected tonight through Wednesday night.
A persistent SW flow increases Thursday with gusts reaching SCA
levels on the ocean waters, the bays of Long Island, and the
far ern Sound. A few gusts to 35 kt may even be possible on the
ocean waters especially out east, and the 06Z HRRR signals
potential for a longer duration of 35-kt gusts late afternoon
and early evening Thu for the ocean E of Fire Island Inlet. Seas
per NWPS should build to 6-9 ft during this time as well.
SCA conditions should ramp down from late Thu night into Fri
morning. However, a brief period of 25 kt gusts is again
possible on Sat with passage of a cold front, and ocean seas up
to 5 ft expected as southerly flow increases ahead of the
approaching front.
Ocean seas then subside by late Sat night and remain below SCA
levels through Mon as winds become more NW.
&&
.HYDROLOGY...
Locally heavy rain is possible from late afternoon into early
evening Thu, which may cause minor nuisance and poor drainage
flooding.
&&
.TIDES/COASTAL FLOODING...
There is a low risk for the development of rip currents at the
ocean beaches Wednesday and a high risk, especially in the
afternoon, on Thursday.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...Heat Advisory from 11 AM Thursday to 9 PM EDT Friday for
CTZ005>012.
NY...Heat Advisory from 11 AM Thursday to 9 PM EDT Friday for
NYZ067>075-078>081-176>179.
High Rip Current Risk from Thursday afternoon through Thursday
evening for NYZ075-080-081-178-179.
NJ...Heat Advisory from 11 AM Thursday to 9 PM EDT Friday for
NJZ002.
Excessive Heat Watch from Thursday morning through Friday
evening for NJZ004-006-103>108.
MARINE...Small Craft Advisory from noon Thursday to midnight EDT
Thursday night for ANZ332-340-345.
Small Craft Advisory from 8 AM Thursday to 6 AM EDT Friday for
ANZ350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...BG/JP
NEAR TERM...BG
SHORT TERM...BG
LONG TERM...JP
AVIATION...JP
MARINE...BG/JP
HYDROLOGY...BG/JP
TIDES/COASTAL FLOODING...