Special Marine Warning 93, NWS Philadelphia/Mount Holly

Area Forecast Discussion
National Weather Service Mount Holly NJ
241 PM EDT Sat Jul 18 2026

.WHAT HAS CHANGED...
A Tornado Watch has been issued for the entire region through 9
PM tonight. A Flood Watch also remains in effect for portions of
the region through late tonight.

&&

.KEY MESSAGES...
1. Widespread severe weather as well as flash flooding remains
anticipated for the remainder of today into tonight.

2. Lingering smoke from Canadian wildfires will be swept away
by late today. Hot temperatures and high dew points will also
make conditions uncomfortable.

3. Mainly fair and dry weather is expected for Sunday through Monday
before the next chance for showers and thunderstorms returns
on Tuesday.

&&

.DISCUSSION...
KEY MESSAGE 1...Widespread severe weather as well as flash
flooding remains anticipated for the remainder of today into
tonight.

Bottom line up front: There remains an elevated threat for
widespread severe weather and flash flooding for the remainder
of today into tonight. A Tornado Watch has been issued for the
entire region through 9 PM tonight. A Flood Watch remains in
effect for a large portion of the area from the urban corridor
northward until 2 AM tonight. The area remains in an Enhanced
risk from SPC for severe weather. This means that instances of
severe weather are likely to be fairly widespread across the
area compared to the more typical scattered coverage that we
often see. The primary threats are damaging winds as well as
tornadoes, with potential for a stronger tornado, potentially as
strong as an EF2.

Getting into the weeds, low pressure will be moving into
portions of eastern Ontario and southern Quebec by late
today. A warm front pushed through earlier with an initial round
of showers and storms and will be followed by a cold front
later tonight.

ML CAPE values look to really surge this afternoon as well
aided by very high dew points. CAPE should max out at least in
the 1500-2500 range with the potential for it to even go 3000+
depending on how warm we get. In addition, deep layer shear
looks to be 40-50 knots with strong low level shear and turning
of the winds as well. The anomalously high dew points expected
will also help LCL values get quite low with PWAT values progged
to surge to over 2.2 inches. This all means that the second
round of storms this afternoon into the evening will be easily
capable of producing damaging winds and torrential rainfall
leading to flash flooding.

Expect convection to take the form of multi-cell clusters
and/or line segments with the potential for embedded supercells.
A few tornadoes will also be possible. In fact the SPC has much
of the area in a relatively rarely issued for this area 5% risk
of tornadoes, and has highlighted most of our forecast areas
with the potential for an EF2 tornado.

In terms of the heavy rainfall and associated flash flood
threat, this looks to be highest from northern Delaware to
northern parts of South Jersey on northward where we have the
Flood Watch in effect. Given the very high PWATs described
above, storms will be capable of producing rain amounts of 2-3
inches within a period of just 1-2 hours. The flood threat will
be greatest for urban, low lying areas, and areas near streams
and creeks. Areas that get hit hard repeatedly by the multiple
rounds of convection will also be particularly vulnerable. And
in fact there will be the potential for a final round of
convection to move through later this evening just ahead of the
actual cold front.

Showers/storms should finally wind down heading into the
overnight period tonight as the cold front pushes through.

KEY MESSAGE 2...Lingering smoke from Canadian wildfires will be
swept away by late today. Hot temperatures and high dew points will
also make conditions uncomfortable.

Smoke from the Canadian wildfires remains in the region early
this afternoon. However, the developing southerly flow should
start to push the smoke out by late this afternoon into this
evening. Expected convection may also help improve things.

With the southerly flow though, temperatures and dew points
ramp up. Generally expect highs in the 80s with heat indices of
over 90 for much of the area with the potential for heat indices
to hit near 100 to 105 near and south of around Philly where
highs will range from the upper 80s to mid 90s. A Heat Advisory
has been issued for portions of the eastern shore of Maryland
and southern Delaware where 105 or greater heat indices are
occurring. Further north, lingering smoke and cloud cover/precip
look to hold temps down just enough to prevent advisory
criteria from being reached.

KEY MESSAGE 3...Mainly fair and dry weather is expected for Sunday
through Monday before the next chance for showers and thunderstorms
returns on Tuesday.

Sunday is shaping up to feature sunshine with both lower
temperatures and lower humidity levels as a high pressure system
builds in. Generally expect highs ranging from the 70s to near 80
over our northern zones over NE PA into NW NJ with low to mid 80s
near the urban corridor and mid to upper 80s over portions of our
eastern MD shore counties and southern Delaware. Dew points will be
much lower compared to Saturday so the heat indices will be close to
the actual air temperatures.

High pressure remains in control for Monday with temperature and
humidity levels remaining similar to Sunday. It remains mainly sunny
on Monday with light winds. Beyond Monday, it turns unsettled. The
next frontal system approaches Tuesday with increasing humidity
returning ahead of it and showers/storms likely Tuesday into Tuesday
night as the system moves through. This is still several days out
but it's worth noting that WPC and SPC are already indicating
threats for heavy rainfall and flash flooding as well as severe
storms. Highs on Tuesday are generally in the 80s with heat indices
in the upper 80s to mid 90s from around the urban corridor extending
southward. It's possible some showers and storms linger into
Wednesday but the general trend should be towards improving
conditions, especially by late day.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Remainder of Today...Several waves of SHRA/TSRA continuing,
with sub-VFR conditions. Stronger TSRA will be capable of brief
wind gusts in excess of 50 kt. Outside of TSRA, some lingering
FU has kept VSBYs low but is gradually improving. Winds will be
out of the S-SW around 10 kts. Low confidence.

Tonight...Sub-VFR conds in lingering SHRA/TSRA through 02-04Z
then improving to VFR. Winds turning from west-southwest to
northwest, around 5-10 kts. Low confidence.

Sunday...VFR. Northwest winds around 10 kts. High confidence.

Outlook...

Sunday night through Monday...VFR. No significant weather.

Tuesday through Wednesday...Sub-VFR conditions possible in
SHRA/TSRA.

Thursday...VFR. No significant weather.

&&

.MARINE...
Winds shift more south-southwest and increase ahead of a strong
cold front today. A Small Craft Advisory is in effect for all
near shore ocean zones and continues until midnight tonight for
our southern two zones off the coast of Delaware and adjacent
to the Delaware Bay. Farther north, the SCA runs until 4 AM
Sunday. Expect winds gusting to around 30 knots with seas
getting up to 5-6 foot range.

A Tornado Watch is also in effect for all near shore coastal
waters as well as the Delware Bay through 9 PM this evening.
Waterspouts will be possible with strong to severe thunderstorms
in addition to wind gusts potentially over 50 kts and
lightning.

Outlook...

Sunday through Monday...Conditions are expected to remain below SCA
criteria.

Tuesday through Wednesday...Winds and seas likely approach SCA
criteria by late day Tuesday and could linger through Wednesday
night.

Thursday...Conditions are expected to remain below SCA criteria.

Rip Currents...

For today, south winds strengthen to around 15-20 MPH (with the
exception of Monmouth County where winds will be a bit
lighter). Winds will have an onshore component for Cape May
County, Atlantic County, and Ocean County in NJ and be more
shore parallel for the Delaware Beaches and Monmouth County
beaches. Ended up going a MODERATE risk for rip currents where
the winds are strongest and where there is an onshore component
(Cape May, Atlantic, Ocean), with a LOW risk elsewhere (Monmouth
and Sussex). Breaking waves start around 1 to 2 feet, but
gradually increase through the day to around 2 to 3 feet. The
wave period will be around 8 seconds. Given lower wave heights
and a short to medium period, thinking a high risk is not
necessary at this time.

For Sunday, winds turn offshore, becoming northwesterly up to 10
MPH. Still a medium period swell with wave heights around 2 feet
as well. All of this will result in a LOW risk for rip currents
at all beaches.

For specific beach forecasts, visit weather.gov/beach/phi

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Flood Watch until 2 AM EDT Sunday for PAZ054-055-060>062-070-
     071-101>106.
NJ...Flood Watch until 2 AM EDT Sunday for NJZ001-007>010-012>020-
     026-027.
DE...Flood Watch until 2 AM EDT Sunday for DEZ001.
     Heat Advisory until 8 PM EDT this evening for DEZ003.
MD...Heat Advisory until 8 PM EDT this evening for MDZ015-019-020.
MARINE...Small Craft Advisory until 4 AM EDT Sunday for ANZ450>453.
     Small Craft Advisory until midnight EDT tonight for ANZ454-455.

&&

DISCUSSION...AKL/Guzzo
AVIATION...AKL/Guzzo
MARINE...AKL/Guzzo

Hazardous Weather Outlook
National Weather Service Mount Holly NJ
507 AM EDT Sat Jul 18 2026

MDZ015-019-020-190915-
Queen Annes-Talbot-Caroline-
507 AM EDT Sat Jul 18 2026

...HEAT ADVISORY IN EFFECT FROM NOON TODAY TO 8 PM EDT THIS
EVENING...

This Hazardous Weather Outlook is for northeast Maryland.

.DAY ONE...Today and tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Heat Advisory.

Thunderstorms may produce severe weather and flash flooding
today.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

Thunderstorms may produce severe weather and flash flooding
Tuesday and Wednesday.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

MDZ012-190915-
Kent MD-
507 AM EDT Sat Jul 18 2026

This Hazardous Weather Outlook is for northeast Maryland.

.DAY ONE...Today and tonight.

Thunderstorms may produce severe weather and flash flooding
today.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

Thunderstorms may produce severe weather and flash flooding
Tuesday and Wednesday.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

Preliminary Local Storm Report
National Weather Service Mount Holly NJ
220 PM EDT Sat Jul 18 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0212 PM     Flood            Laurence Harbor         40.46N 74.25W
07/18/2026                   Middlesex          NJ   Dept of Highways

            NJDOT reported flooding on NJ 35 Both
            Directions At CR 689/Lawrence Pkwy (Old
            Bridge Twp), All lanes closed northbound;
            All lanes closed southbound.

&&

MJL

Preliminary Local Storm Report
National Weather Service Mount Holly NJ
229 PM EDT Sat Jul 18 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0221 PM     Flood            1 SW Cheesequake        40.42N 74.30W
07/18/2026                   Middlesex          NJ   Dept of Highways

            NJDOT reported flooding on US 9 Northbound
            At Jake Brown Rd (Old Bridge Twp), All lanes
            closed.

&&

MJL

Preliminary Local Storm Report
National Weather Service Mount Holly NJ
234 PM EDT Sat Jul 18 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0233 PM     Flood            1 ESE South River       40.45N 74.37W
07/18/2026                   Middlesex          NJ   Trained Spotter

            Trained spotter reported Whitehead Ave in
            South River closed due to flooding.

&&

MJL

Preliminary Local Storm Report
National Weather Service Mount Holly NJ
249 PM EDT Sat Jul 18 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0156 PM     Flood            Metuchen                40.54N 74.36W
07/18/2026                   Middlesex          NJ   Dept of Highways

            NJDOT reported flooding on NJ 27 Both
            Directions North of CR 501/Amboy Ave
            (Metuchen), 1 right lane of 2 lanes closed
            northbound; 1 right lane of 2 lanes closed
            southbound.

&&

MJL

<!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>

Preliminary Local Storm Report
National Weather Service Mount Holly NJ
304 PM EDT Sat Jul 18 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0250 PM     Flood            1 N Spotswood           40.41N 74.39W
07/18/2026                   Middlesex          NJ   Newspaper

            Local news site reported flooding on Old
            Stage Road and Summerhill Road.

&&

MJL