Alert archive / New Jersey / Special Marine Warnings in 2026

Special Marine Warning 13, NWS Philadelphia/Mount Holly

April 1, 2026

NWS Philadelphia/Mount Holly issued this special marine warning at Apr 1, 2026, 10:39 PM EDT. It was in force for 55 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Apr 1, 2026, 10:39 PM EDT (02:39 UTC)
Expired
Apr 1, 2026, 11:34 PM EDT
In force
55 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.0 in
Wind
34.0 mph

The radar

The Philadelphia radar (KDIX), 58 km from the middle of the area, began a volume at 02:41 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 2.7 hours before the alert went out and 209 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Brookhaven, NY at 00:00Z on 2026-04-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 00:00Z on 2026-04-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -42 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1066 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
-42 m²/s²
0-3 km storm-relative helicity
71 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

314 
WHUS51 KPHI 020239
SMWPHI
ANZ451>453-472-473-020345-
/O.NEW.KPHI.MA.W.0013.260402T0239Z-260402T0345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mount Holly NJ
1039 PM EDT Wed Apr 1 2026

The National Weather Service in Mount Holly NJ has issued a

* Special Marine Warning for...
  Coastal waters from Manasquan Inlet to Cape May NJ out 20 nm...
  Outer waters from Little Egg Inlet to Cape May NJ out 20 to 40
  nm...

* Until 1145 PM EDT.

* At 1039 PM EDT, strong thunderstorms were located along a line
  extending from 11 nm northwest of Atlantic City to near The Lump,
  moving east at 25 knots.

  HAZARD...Wind gusts 34 knots or greater.

  SOURCE...Radar.

  IMPACT...Small craft could be damaged in briefly higher winds and 
           suddenly higher waves.

* Locations impacted include...
  Atlantic City, Little Egg Reef, Atlantic City Reef, Ship Bottom,
  Great Egg Inlet, Garden State South Reef, Great Egg Reef, Ocean
  City Reef, Beach Haven, North Beach Haven, The Lump, Garden State
  North Reef, Little Egg Inlet, Buoy Ge, Brigantine, and Sea Isle
  City.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor until hazardous weather passes.

Frequent lightning is occurring with these storms. If caught on the
open water, stay below deck if possible and keep away from ungrounded
metal objects.

&&

LAT...LON 3903 7395 3903 7470 3948 7469 3944 7465
      3938 7466 3938 7464 3947 7450 3956 7459
      3960 7459 3962 7449 3960 7439 3964 7435
      3969 7395
TIME...MOT...LOC 0239Z 261DEG 27KT 3954 7461 3911 7458 

HAIL...0.00IN
WIND...>34KTS

$$

MJL
1 follow-up statement
335 
FZUS71 KPHI 020334
MWSPHI

Marine Weather Statement
National Weather Service Mount Holly NJ
1134 PM EDT Wed Apr 1 2026

ANZ451>453-472-473-020344-
/O.CAN.KPHI.MA.W.0013.000000T0000Z-260402T0345Z/
1134 PM EDT Wed Apr 1 2026

...THE SPECIAL MARINE WARNING IS CANCELLED...

The affected areas were... 
Coastal waters from Manasquan Inlet to Cape May NJ out 20 nm...
Outer waters from Little Egg Inlet to Cape May NJ out 20 to 40 nm...

The thunderstorms have weakened and no longer pose a significant
threat to boaters.

LAT...LON 3903 7395 3903 7470 3948 7469 3944 7465
      3938 7466 3938 7464 3947 7450 3956 7459
      3960 7459 3962 7449 3960 7439 3964 7435
      3969 7395
TIME...MOT...LOC 0332Z 261DEG 27KT 3960 7410 3917 7407 

$$

MJL

What forecasters said that day

The local office's own words before this special marine warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Philadelphia/Mount Holly wrote its last area forecast discussion before this special marine warning went out at Apr 1, 7:31 PM EDT, 3 hours 8 minutes earlier. Its key messages:

  • 1. A cold front crosses the region through this evening. Showers and some thunderstorms will accompany the front, with some severe thunderstorm risk this evening. 2. A warm front lifts north through the region Thursday night into Friday, and then a strong cold front passes through this weekend with colder temperatures for the start of the new work week.
Area forecast discussion, Apr 1, 7:31 PM EDT, 3 hours 8 minutes before
Area Forecast Discussion
National Weather Service Mount Holly NJ
731 PM EDT Wed Apr 1 2026

.WHAT HAS CHANGED...
The main severe thunderstorm risk is mainly across portions of
Delmarva to far southern New Jersey.

&&

.KEY MESSAGES...
1. A cold front crosses the region through this evening. Showers
and some thunderstorms will accompany the front, with some severe
thunderstorm risk this evening.

2. A warm front lifts north through the region Thursday night
into Friday, and then a strong cold front passes through this
weekend with colder temperatures for the start of the new work
week.

&&

.DISCUSSION...
KEY MESSAGE 1...A cold front crosses the region through this evening.
Showers and some thunderstorms will accompany the front, with
some severe thunderstorm risk this evening.

The region remains embedded within modestly enhanced southwesterly
flow aloft. A belt of 50 kt 500 mb winds will shift eastward
over the region this evening. At the surface, a cold front
continues to settle southward. It will cross the region this
evening before stalling near Delmarva on Thursday.

MLCAPE of 500-1000 J/kg from near Philadelphia southward with
the highest values in Delmarva. 0-6 km Bulk Shear values of
30-40 kt are in place. Some convection sliding across Delmarva
has shown some strengthening. The greatest DCAPE is across
parts of Delmarva to far southern New Jersey. A few stronger
convective cores could be severe this evening with locally
damaging winds the main threat. The severe risk is highest over
Delmarva to far southern NJ due to the overlap of the greatest
instability and also DCAPE. The severe threat diminishes
significantly north of the southward advancing cold front.

Some lingering showers should then occur through much of the
night in the wake of the front. Low temperatures are expected to
be in the 40s for most of the region, with 50s in Delmarva
where the front will move through the latest.

A much colder airmass is anticipated to settle southward
overnight and especially on Thursday in the wake of the front,
though if the front stalls over southern portions of the area a
tight temperature gradient will exist near it. Highs are
generally expected to be in the 40s to mid 50s across most of
eastern PA and NJ, with 60s in portions of Delaware and the
Eastern Shore of Maryland depending on where exactly the front
sets up.

KEY MESSAGE 2...A warm front lifts north through the region
Thursday night into Friday, and then a strong cold front passes
through this weekend with colder temperatures for the start of
the new work week.

Strong low pressure over the Midwest Thursday evening will lift
to the northeast into the Upper Great Lakes and the southeast
portion of the Province of Ontario Thursday night and Friday
morning. This will pull the stationary boundary south of the
area north as a warm front, and this warm front should clear the
northern zones by midday Friday or so. Some light rain is
possible with its passage, and with increasing low level
moisture, there may be some patchy fog. The low over southern
Canada passes through eastern Canada Friday and Friday night.

Strong warm air advection will be underway for Friday and
Saturday with temperatures returning to well above normal
levels. Highs will top off in the 70s to low 80s both days.

A new area of low pressure organizes and develops over the
Midwest Friday and Friday night. This low lifts towards the
Great Lakes and southern central Canada Saturday and Saturday
night. Another warm front lifts north through the region, and
this may touch off some showers and perhaps a thunderstorm
Saturday afternoon and Saturday night.

As low pressure continues to track to the north and east,
passing through southern Canada, it will drag a strong cold
front through the region on Sunday. Widespread showers, perhaps
a few thunderstorms, will develop with its passage. The showers
should knock temperatures down by some 10 degrees or so compared
to Saturday, as highs will be in the 60s to around 70.

Strong cold air advection develops behind the passage of the
front Sunday night. Highs will only be in the mid to upper 50s
for most of the area, and in the upper 40s in the southern
Poconos, Monday and Tuesday. These temperatures are several
degrees below normal for this time of the year.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Tonight....VFR ceilings expand then lower to MVFR. Ceilings are
expected to lower to IFR overnight from south to north. Some
showers and thunderstorms from west to east through about 05z,
then some showers should linger overnight. The greatest chance
for some thunderstorms looks to be from about the PHL metro area
on southward. Winds becoming north to northeast around 10 knots,
with some gusts 15-20 knots especially overnight. Low confidence.

Thursday...IFR ceilings may improve to MVFR. A few showers possible
especially through the morning, and some drizzle cannot be ruled
out. East-northeast winds 10-15 knots with some gusts 20-25 knots.
Low confidence.

Outlook...

Thursday night...Sub-VFR likely in low stratus, BR, and DZ.

Friday through Friday night...Primarily VFR.

Saturday through Saturday night...Primarily VFR, but sub-VFR
possible in any SHRA.

Sunday through Sunday night...Sub-VFR in SHRA and/or TSRA.

Monday...VFR expected.

&&

.MARINE...
Small Craft Advisory for the northern to central Atlantic
coastal waters of New Jersey through Thursday evening. Seas are
still elevated across the northern waters but are slowly
subsiding this evening, then a wind shift out of the north and
northeast occurs through tonight and increases with some gusts
up to 30 knots and seas building again.

Some thunderstorms could bring gusty winds and reduced visibilities
this evening.

Outlook...

Thursday night...SCA conditions likely, mostly for elevated
seas on the New Jersey ocean waters. Sub-SCA conditions
elsewhere.

Friday through Friday night...A period of SCA conditions
possible Friday afternoon and evening as winds ramp up and seas
build to around 5 feet.

Saturday through Saturday night...Sub-SCA conditions Saturday,
then SCA conditions likely Saturday night

Sunday through Sunday night...SCA conditions likely with a
brief period of gale force winds possible Sunday afternoon.
Winds diminish to sub-SCA levels Sunday night, but seas remain
elevated. Visibility restrictions in showers expected.

Monday...Sub-SCA conditions likely.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory until midnight EDT Thursday night for
     ANZ450>452.

&&

DISCUSSION...Cooper/Gorse/MPS
AVIATION...Cooper/Gorse/MPS
MARINE...Cooper/Gorse/MPS
Hazardous weather outlook, Apr 1, 5:07 AM EDT, 17 hours 32 minutes before
Hazardous Weather Outlook
National Weather Service Mount Holly NJ
507 AM EDT Wed Apr 1 2026

MDZ012-015-019-020-020915-
Kent MD-Queen Annes-Talbot-Caroline-
507 AM EDT Wed Apr 1 2026

This Hazardous Weather Outlook is for northeast Maryland.

.DAY ONE...Today and tonight.

Isolated strong to severe storms are possible this afternoon and
evening with the primary threat being damaging wind gusts.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

In the hours before

Local storm report, Apr 1, 7:55 PM EDT, 2 hours 44 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
755 PM EDT Wed Apr 1 2026

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

0739 PM     Tstm Wnd Gst     1 N Smyrna              39.32N 75.61W
04/01/2026  M41 MPH          New Castle         DE   Dept of Highways

            DelDOT station at DEMA EOC.

&&

Staarmann
Local storm report, Apr 1, 8:40 PM EDT, 1 hour 59 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
840 PM EDT Wed Apr 1 2026

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

0815 PM     Tstm Wnd Gst     2 WSW Stow Creek Twp    39.44N 75.38W
04/01/2026  M44 MPH          Cumberland         NJ   Mesonet

            NJWxNet Mesonet station Greenwich.

&&

Staarmann
Local storm report, Apr 1, 9:15 PM EDT, 1 hour 24 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
915 PM EDT Wed Apr 1 2026

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

0730 PM     Tstm Wnd Dmg     Clayton                 39.30N 75.63W
04/01/2026                   Kent               DE   911 Call Center

            Tree down onto a house in the Clayton Courts
            neighborhood. Time estimated from radar.

&&

Staarmann
Local storm report, Apr 1, 9:17 PM EDT, 1 hour 22 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
917 PM EDT Wed Apr 1 2026

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

0730 PM     Tstm Wnd Dmg     Clayton                 39.29N 75.63W
04/01/2026                   Kent               DE   911 Call Center

            Several reports of large trees and power
            lines down in Clayton. Time estimated from
            radar.

&&

Staarmann
Local storm report, Apr 1, 9:18 PM EDT, 1 hour 21 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
918 PM EDT Wed Apr 1 2026

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

0734 PM     Tstm Wnd Dmg     Smyrna                  39.30N 75.60W
04/01/2026                   Kent               DE   911 Call Center

            Several reports of large trees and power
            lines down in Smyrna. Time estimated from
            radar.

&&

Staarmann
Local storm report, Apr 1, 9:23 PM EDT, 1 hour 16 minutes before
Preliminary Local Storm Report...Summary
National Weather Service Mount Holly NJ
923 PM EDT Wed Apr 1 2026

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

0730 PM     Tstm Wnd Dmg     Clayton                 39.29N 75.63W
04/01/2026                   Kent               DE   911 Call Center

            Several reports of large trees and power
            lines down in Clayton. Time estimated from
            radar.

0730 PM     Tstm Wnd Dmg     Clayton                 39.30N 75.63W
04/01/2026                   Kent               DE   911 Call Center

            Tree down onto a house in the Clayton Courts
            neighborhood. Time estimated from radar.

0734 PM     Tstm Wnd Dmg     Smyrna                  39.30N 75.60W
04/01/2026                   Kent               DE   911 Call Center

            Several reports of large trees and power
            lines down in Smyrna. Time estimated from
            radar.

0735 PM     Tstm Wnd Gst     1 SW Clayton            39.28N 75.65W
04/01/2026  M42 MPH          Kent               DE   Mesonet

            Wunderground station KDECLAYT7.

0739 PM     Tstm Wnd Gst     1 N Smyrna              39.32N 75.61W
04/01/2026  M41 MPH          New Castle         DE   Dept of Highways

            DelDOT station at DEMA EOC.

0745 PM     Tstm Wnd Gst     1 N Smyrna              39.32N 75.61W
04/01/2026  M41 MPH          New Castle         DE   Mesonet

            Wudnerground station KDESMYRN24.

0815 PM     Tstm Wnd Gst     2 WSW Stow Creek Twp    39.44N 75.38W
04/01/2026  M44 MPH          Cumberland         NJ   Mesonet

            NJWxNet Mesonet station Greenwich.

&&

Staarmann

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 1, 8:00 PM EDTSevere Thunderstorm WarningPHICumberland, Salem45 min
Apr 1, 11:33 PM EDTSpecial Marine WarningPHI42 min
Apr 2, 5:26 PM EDTMarine Dense Fog AdvisoryPHI21 hr
Apr 1, 11:24 PM EDTSevere Thunderstorm WarningPHISussex36 min
Apr 1, 11:27 PM EDTSevere Thunderstorm WarningPHIKent, Sussex33 min
Apr 1, 11:46 PM EDTSevere Thunderstorm WarningPHISussex14 min

Nearby

Special Marine Warnings in New Jersey, 2026Every special marine warning in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.