Alert archive / Delaware / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 203, NWS Philadelphia/Mount Holly

July 18, 2026Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 18, 2026, 7:09 PM EDT for Sussex County, Delaware. It was in force for 8 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
Jul 18, 2026, 7:09 PM EDT (23:09 UTC)
Expired
Jul 18, 2026, 7:17 PM EDT
In force
8 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

County Sussex County, DE

The radar

The Dover AFB radar (KDOX), 50 km from the middle of the area, began a volume at 23:09 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jul 18, 1:55 PM EDTTornado WatchSPC6 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 11.2 hours before the alert went out and 212 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, Washington/Dulle, VA at 12:00Z on 2026-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1396 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2026-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 126 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
1396 J/kg
Mixed-layer CIN
-112 J/kg
Mixed-layer LCL
936 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
126 m²/s²
0-3 km storm-relative helicity
131 m²/s²
Significant tornado parameter
0.4
Supercell composite
5.1

Open this sounding in Storm Lab

The text

As transmitted.

817 
WUUS51 KPHI 182309
SVRPHI
DEC005-182330-
/O.NEW.KPHI.SV.W.0203.260718T2309Z-260718T2330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
709 PM EDT Sat Jul 18 2026

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southeastern Sussex County in southern Delaware...

* Until 730 PM EDT.

* At 709 PM EDT, a severe thunderstorm was located near Millville, or
  14 miles north of Ocean City, moving east at 35 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Damage to roofs, siding, trees, and power lines is 
           possible.

* Locations impacted include...
  Millville, Long Neck, Ocean View, South Bethany, and Dewey Beach.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 900 PM EDT for southern
Delaware.

For your protection move to an interior room on the lowest floor of a
building.

To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in Mount Holly NJ.

A Tornado Watch remains in effect until 900 PM EDT for southern
Delaware.

&&

LAT...LON 3845 7503 3846 7505 3845 7505 3845 7512
      3869 7516 3872 7486 3845 7483
TIME...MOT...LOC 2309Z 263DEG 31KT 3857 7503 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

MPS
1 follow-up statement
109 
WWUS51 KPHI 182317
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
717 PM EDT Sat Jul 18 2026

DEC005-182327-
/O.CAN.KPHI.SV.W.0203.000000T0000Z-260718T2330Z/
Sussex DE-
717 PM EDT Sat Jul 18 2026

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN SUSSEX COUNTY IS
CANCELLED...

The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 900 PM EDT for southern
Delaware.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Mount Holly NJ.

LAT...LON 3845 7503 3846 7505 3845 7505 3845 7512
      3869 7516 3872 7486 3845 7483
TIME...MOT...LOC 2315Z 263DEG 31KT 3858 7494 

$$

MPS

What forecasters said that day

The local office's own words before this severe thunderstorm 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 severe thunderstorm warning went out at Jul 18, 4:19 PM EDT, 2 hours 50 minutes earlier. Its 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.
Area forecast discussion, Jul 18, 4:19 PM EDT, 2 hours 50 minutes before
Area Forecast Discussion
National Weather Service Mount Holly NJ
419 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 /20Z 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 Sunday, winds turn offshore, becoming northwesterly up to
10 MPH. A medium period swell with wave heights in the surf zone
around 2 feet or less. All of this will result in a LOW risk
for rip currents at all beaches.

For Monday, winds turn back onshore, but remain around 10 MPH.
Medium period swell with wave heights around 2 feet or less
continuing. As a result, the rip current risk will remain LOW
for Monday 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, Jul 18, 5:07 AM EDT, 14 hours 2 minutes before
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.

In the hours before

Local storm report, Jul 18, 6:48 PM EDT, 21 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
648 PM EDT Sat Jul 18 2026

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

0642 PM     Marine Tstm Wind 2 NNW Sea Isle City     39.18N 74.70W
07/18/2026  M47 MPH          ANZ453             NJ   Buoy

            Ludlam Bay buoy.

&&

Hoeflich
Local storm report, Jul 18, 6:53 PM EDT, 16 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
653 PM EDT Sat Jul 18 2026

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

0649 PM     Marine Tstm Wind 2 NE Strathmere         39.22N 74.63W
07/18/2026  M44 MPH          ANZ453             NJ   Mesonet

            Ocean City South Beach mesonet.

&&

Hoeflich
Local storm report, Jul 18, 7:03 PM EDT, 6 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
703 PM EDT Sat Jul 18 2026

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

0451 PM     Tstm Wnd Dmg     1 S Betterton           39.36N 76.06W
07/18/2026                   Kent               MD   911 Call Center

            Reports of trees and wires down around
            Betterton. Time estimated by radar.

&&

MJL
Local storm report, Jul 18, 7:05 PM EDT, 4 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
705 PM EDT Sat Jul 18 2026

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

0705 PM     Marine Tstm Wind 1 NNW Lewes             38.79N 75.14W
07/18/2026  M63 MPH          ANZ431             DE   Mesonet

            Lewes Mesonet.

&&

Hoeflich
Local storm report, Jul 18, 7:07 PM EDT, 2 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
707 PM EDT Sat Jul 18 2026

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

0702 PM     Marine Tstm Wind Indian Beach            38.69N 75.08W
07/18/2026  M53 MPH          ANZ455             DE   Mesonet

            Dewey Beach mesonet.

&&

Hoeflich
Local storm report, Jul 18, 7:09 PM EDT, 0 minutes before
Preliminary Local Storm Report
National Weather Service Mount Holly NJ
709 PM EDT Sat Jul 18 2026

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

0618 PM     Marine Tstm Wind 8 W Cape May Point      38.95N 75.11W
07/18/2026  M42 MPH          ANZ431             NJ   Buoy

            Brandywine Shoal Light.

&&

Hoeflich

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 18, 2:12 AM EDTHeat AdvisoryPHISussex17 hr
Jul 18, 5:14 PM EDTSevere Thunderstorm WarningPHIKent, New Castle61 min
Jul 18, 5:26 PM EDTSevere Thunderstorm Warning Destructive damage threatPHIKent, Sussex49 min
Jul 18, 6:16 PM EDTSevere Thunderstorm WarningPHISussex44 min
Jul 18, 6:27 PM EDTTornado WarningPHISussex33 min
Jul 18, 6:40 PM EDTSevere Thunderstorm Warning Considerable damage threatPHIKent, Sussex36 min
Jul 18, 6:54 PM EDTSevere Thunderstorm WarningPHISussex22 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2026Every severe thunderstorm 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.