Alert archive / Delaware / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 320, NWS Philadelphia/Mount Holly

August 20, 2026Kent County, Sussex County, Delaware; Caroline County, Talbot County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 20, 2026, 6:57 PM EDT for Kent County, Sussex County, Delaware; Caroline County, Talbot County, Maryland. It was in force for 48 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
Aug 20, 2026, 6:57 PM EDT (22:57 UTC)
Expired
Aug 20, 2026, 7:45 PM EDT
In force
48 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Kent County, DE, Sussex County, DE, Caroline County, MD, Talbot County, MD

The radar

The Dover AFB radar (KDOX), 33 km from the middle of the area, began a volume at 22:59 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 watch it was issued in

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

IssuedProductOfficeLasted
Aug 20, 2:31 PM EDTSevere Thunderstorm WatchSPC7 hr
Aug 20, 2:58 PM EDTTornado WatchSPC7 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 11.0 hours before the alert went out and 146 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 2026-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 97 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 2026-08-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 115 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
97 J/kg
Mixed-layer CIN
-72 J/kg
Mixed-layer LCL
1192 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
115 m²/s²
0-3 km storm-relative helicity
230 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted.

842 
WUUS51 KPHI 202257
SVRPHI
DEC001-005-MDC011-041-202345-
/O.NEW.KPHI.SV.W.0320.260820T2257Z-260820T2345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
Issued by National Weather Service New York NY
657 PM EDT Thu Aug 20 2026

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Sussex County in southern Delaware...
  Southwestern Kent County in central Delaware...
  Southeastern Talbot County in eastern Maryland...
  Caroline County in eastern Maryland...

* Until 745 PM EDT.

* At 656 PM EDT, a severe thunderstorm was located over Preston, or
  near Hurlock, moving east at 35 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to trees and power lines.

* Locations impacted include...
  Georgetown, Milford, Seaford, Denton, Millsboro, Laurel,
  Harrington, Lewes, Federalsburg, Milton, Bridgeville, Delmar,
  Preston, Ellendale, and Gumboro.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1000 PM EDT for central and
southern Delaware...and eastern Maryland.

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

A Tornado Watch remains in effect until 1000 PM EDT for central and
southern Delaware...and eastern Maryland.

&&

LAT...LON 3846 7569 3863 7571 3869 7576 3868 7580
      3870 7580 3871 7584 3869 7588 3870 7590
      3868 7592 3868 7594 3859 7600 3857 7602
      3858 7605 3895 7586 3893 7526 3882 7518
      3845 7530
TIME...MOT...LOC 2256Z 278DEG 32KT 3870 7591 

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

$$

DeSilva
2 follow-up statements
908 
WWUS51 KPHI 202317
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
Issued by National Weather Service New York NY
717 PM EDT Thu Aug 20 2026

DEC001-MDC041-202326-
/O.CAN.KPHI.SV.W.0320.000000T0000Z-260820T2345Z/
Kent DE-Talbot MD-
717 PM EDT Thu Aug 20 2026

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN KENT AND
SOUTHEASTERN TALBOT COUNTIES IS CANCELLED...

The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 1000 PM EDT for central and
southern Delaware...and eastern Maryland.

LAT...LON 3846 7569 3863 7571 3869 7576 3868 7580
      3870 7580 3871 7584 3869 7588 3870 7590
      3868 7592 3868 7594 3878 7584 3883 7567
      3884 7556 3885 7555 3882 7518 3845 7530
TIME...MOT...LOC 2316Z 272DEG 32KT 3867 7568 

$$

DEC005-MDC011-202345-
/O.CON.KPHI.SV.W.0320.000000T0000Z-260820T2345Z/
Sussex DE-Caroline MD-
717 PM EDT Thu Aug 20 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT
FOR SUSSEX AND SOUTHEASTERN CAROLINE COUNTIES...

At 716 PM EDT, a severe thunderstorm was located near Seaford, or 10
miles east of Hurlock, moving east at 35 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to trees and power lines.

Locations impacted include...
Georgetown, Seaford, Millsboro, Laurel, Lewes, Federalsburg, Milton,
Bridgeville, Delmar, Preston, Ellendale, Gumboro, Smithville, Agner,
and Sycamore.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1000 PM EDT for central and
southern Delaware...and eastern Maryland.

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

&&

LAT...LON 3846 7569 3863 7571 3869 7576 3868 7580
      3870 7580 3871 7584 3869 7588 3870 7590
      3868 7592 3868 7594 3878 7584 3883 7567
      3884 7556 3885 7555 3882 7518 3845 7530
TIME...MOT...LOC 2316Z 272DEG 32KT 3867 7568 

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

$$

DeSilva
069 
WWUS51 KPHI 202340
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
Issued by National Weather Service New York NY
740 PM EDT Thu Aug 20 2026

DEC005-MDC011-202350-
/O.EXP.KPHI.SV.W.0320.000000T0000Z-260820T2345Z/
Sussex DE-Caroline MD-
740 PM EDT Thu Aug 20 2026

...THE SEVERE THUNDERSTORM WARNING FOR SUSSEX AND SOUTHEASTERN
CAROLINE COUNTIES WILL EXPIRE AT 745 PM EDT...

The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.

A Tornado Watch remains in effect until 1000 PM EDT for central and
southern Delaware...and eastern Maryland.

LAT...LON 3846 7569 3863 7571 3869 7576 3868 7580
      3870 7580 3871 7584 3869 7588 3870 7590
      3868 7592 3868 7594 3878 7584 3883 7567
      3884 7556 3885 7555 3882 7518 3845 7530
TIME...MOT...LOC 2340Z 278DEG 32KT 3864 7541 

$$

DeSilva

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 20, 4:16 PM EDTTornado WarningPHIKent29 min
Aug 20, 4:50 PM EDTSevere Thunderstorm Warning Considerable damage threatPHINew Castle40 min
Aug 20, 5:27 PM EDTSevere Thunderstorm Warning Considerable damage threatPHINew Castle48 min
Aug 20, 5:39 PM EDTFlash Flood WarningPHINew Castle4 hr
Aug 20, 5:39 PM EDTTornado WarningPHIKent36 min
Aug 20, 5:40 PM EDTSevere Thunderstorm WarningPHIKent50 min
Aug 20, 6:03 PM EDTTornado WarningPHIKent42 min
Aug 20, 6:09 PM EDTSevere Thunderstorm WarningPHIKent, New Castle51 min
Aug 20, 6:13 PM EDTSevere Thunderstorm WarningPHINew Castle47 min
Aug 20, 6:21 PM EDTSevere Thunderstorm WarningPHIKent, Sussex39 min
Aug 20, 6:53 PM EDTFlash Flood Warning Considerable damage threatPHIKent105 min
Aug 20, 2:43 PM EDTTornado WarningPHIKent, Queen Anne's32 min
Aug 20, 5:05 PM EDTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's, Talbot40 min
Aug 20, 5:30 PM EDTTornado WarningPHIKent, Queen Anne's30 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2026Severe Thunderstorm Warnings in Maryland, 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.