Severe Thunderstorm Warning 67, NWS New York, NY

Area Forecast Discussion
National Weather Service New York NY
332 PM EDT Fri Aug 7 2026

.WHAT HAS CHANGED...
Severe Thunderstorm Watch has been issued for NYC metro, NE NJ,
Lower Hudson Valley, Fairfield, and Nassau County until 9 pm.

Heat Advisory has been extended through 8pm Saturday for coastal
CT and Southern Westchester. No additional changes to the heat
advisory have been made.

&&

.KEY MESSAGES...
1) Hot & humid conditions persist through at least Saturday. The
heat will continue into Sunday and Monday, but lower humidity will
reduce most high heat index concerns.

2) Scattered showers and thunderstorms this afternoon and evening
will bring the risk for isolated to scattered instances of
damaging winds and isolated heavy downpours/flash flooding.

3) Chances for showers and thunderstorms continue most
afternoons/evenings through the middle of next week.

&&

.DISCUSSION...
.KEY MESSAGE 1...
An anomalously strong subtropical ridge will gradually break down
into the weekend as the westerlies once again drop back into the
area.

Deep SSW flow from Gulf/Sub-tropic origin will continue a very warm
and more notably a very humid airmass across the region through at
least Saturday.

Daytime highs will run 3 to 7 degrees above normal, well below
records, but the high humidity (mid to upper 70s Tds) will make it
feel quite uncomfortable. Heat index values today have been able to
solidly get into heat advisory criteria. Max heat index values have
been in the upper 90s to 104 across much of the area.

With approaching shortwave on Saturday, perhaps more in the way of
convective debris, and some subtle indication of Tds being slightly
lower (lower to mid 70s). This appears to have heat indices slightly
lower in the mid 90s to lower 100s for NYC, NJ metro, and LI, with
lower to mid 90s interior. Enough confidence in another day of mid
90 heat indices to extend the heat advisory into NYC, NE NJ, LI,
S Westchester, and coastal southern Connecticut.

Better signal for lowering TDs (upper 60s/lower 70s) for Sunday into
Monday in wake of a weak cold front. So although temps will likely
remain very warm in the upper 80s/lower 90s, HI's will likely fall
back into the lower 90s to 95. Heat advisories may need to be
extended for NE NJ, NYC Metro, and LI, but marginal at this
point.

Heat indices may perk back up into the mid to upper 90s on Tuesday
ahead of next approaching series of northern stream shortwaves and
cold front, before a general signal for a cool down to more
seasonable temps for middle of next week.

.KEY MESSAGE 2...
An anomalous ridge to our east over the west will gradually
lose influence over our region as heights fall today into
tomorrow. Simultaneously, a surface trough will approach the
area today and stall into tonight. This will be the main focus
for precipitation today.

We're anticipating isolated showers and thunderstorms to develop
around 3 to 6 PM, mainly focused along sea breeze boundaries. Then,
a surface trough will move into the area into the evening. This will
lead to a scattered to broken line of showers and thunderstorms
developing and tracking west to east across the western half of the
CWA 6 PM to 10 PM. Following 10 PM, the thunderstorms will lose
intensity as they track across eastern portions of the area, mainly
leading to light to moderate showers with a secondary line of light
precipitation possibly transitioning across the area into the first
half of the night.

The primary focus will be through the afternoon and evening for a
severe and flash flood threat. SPC carries a slight risk for severe
thunderstorms across the NYC metro and into points west and north of
NYC. A Severe Thunderstorm Watch has also been issued through 9
PM for the NYC metro, NE NJ, Lower Hudson Valley, Fairfield,
and Nassau County. The primary concern will be for damaging
winds with wind gusts in excess of 60 mph.

CAMs have the near-storm environment looking very juicy with SBCAPE
values between 3000-4000 J/kg with some isolated spots of 4500
J/kg possible. Bulk Wind Shear isn't very high, but certainly
sufficient enough to support the strong thunderstorm development
and maintenance around 25-35 kt in some spots. PWATs will
exceed 2 inches and even near 2.5 inches and 0-3km lapse rates
will range from 8.5 to 9 C/km. All of these parameters point to
optimal conditions for downbursts. 12Z CAMs also carry 1000+
DCAPE values, to further support a damaging wind threat. All of
these values become far less optimal across eastern sections of
our area.

Tornadoes are not a primary concern for today. However, with some
low-level turning of winds hinted in model soundings with some
pockets of higher ESRH, an isolated tornado or two can not be
ruled out.

Strong thunderstorms and downpours are expected. Isolated flash
flooding is possible. WPC carries a Slight risk for this across
ares west of NYC with a Marginal east. 1-2"/hr rainfall rates
are possible with peak rates up to 2.5"/hr, mainly for areas N &
W of NYC. However, its important to consider storm motion which
should be fast enough to reduce the concern for more widespread
or significant flash flood concerns.

.KEY MESSAGE 3...
Saturday into Tuesday, the flow aloft becomes more zonal. During
this period, several shortwaves embedded in the zonal flow aloft
with bring through numerous surface troughs or quasi-cold fronts.
These will support more daily rain chances for afternoons and
evenings most days into the beginning of next week. The only
exception is Sunday which appears drier. Coverage in showers and
thunderstorms each day will vary, but for now we're not
anticipating concern for severe weather. WPC carries another
marginal ERO for northern interior sections of the CWA on
Saturday.

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
A trough of low pressure will remain nearly stationary across the
region into Saturday.

Mainly VFR. Showers and thunderstorms are expected to develop
late this afternoon into the evening. The highest chances are
for the terminals in the vicinity of the NYC metro on NW.
MVFR or lower possible in this activity and there may also be a
brief wind shift to the W or NW and gusts in excess of 35 kt in
the strongest storms.

Conditions should remain VFR tonight, although there is a chance for
brief MVFR or lower at some outlying terminals overnight. Have
included this potential at HPN, SWF, and GON.

S-SSW winds this afternoon around 10 kt. Terminals north of sea
breeze boundaries may remain variable or light W-WNW. Winds will
weaken outside of showers/storms this evening, likely becoming light
and variable at most terminals overnight. W winds increase Saturday
morning with potential sea breezes for coastal terminals in the
afternoon.

 ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments possible for TSRA timing into this evening.

Wind direction could be variable after TSRA passes this evening.

Adjustments to PROB30 TSRA timing Saturday afternoon and evening
possible.

.OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...

Saturday Afternoon-Night: Mainly VFR. Chance of showers and
thunderstorms in the afternoon and evening. SW gusts 15-20 kt
possible in the afternoon.

Sunday-Monday: VFR. Isolated shower/thunderstorm possible well NW of
NYC terminals Monday evening.

Tuesday-Wednesday: Mainly VFR. Low probability of showers and
thunderstorms in the afternoon and evening.

Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90

&&

.MARINE...
A persistent SW flow of 10 to 15 kt with gusts up 20 kt on the
ocean waters late afternoon and evening through Sat. Occasional
gusts to 25 kt possible near entrance to NY Harbor with coastal
jet formation each late afternoon/evening, which could have
ocean seas building to 3-5 ft during these times.

Sub-SCA conditions continue Sunday into mid week next week.

Rip Currents: Persistent SW flow and associated wind waves will
lead to a moderate rip current risk today and Saturday.
Potential for rip current risk to increase to high late
afternoon and evening today with coastal jet development and
increase in breaking waves to 3 to 4 ft, particularly for NYC
and western LI beaches.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory until 8 PM EDT this evening for CTZ005>008.
     Air Quality Alert until 11 PM EDT this evening for CTZ007>012.
     Heat Advisory until 8 PM EDT Saturday for CTZ009>012.
NY...Heat Advisory until 8 PM EDT this evening for NYZ067>070.
     Air Quality Alert until 11 PM EDT this evening for NYZ069>075-
     078>081-176>179.
     Heat Advisory until 8 PM EDT Saturday for NYZ071>075-078>081-
     176>179.
NJ...Heat Advisory until 8 PM EDT Saturday for NJZ002-004-006-
     103>108.
MARINE...None.

&&

DISCUSSION...BR
AVIATION...DS
MARINE...BR

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>