Alert archive / Delaware / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 263, NWS Philadelphia/Mount Holly

August 27, 2020Caroline County, Maryland; Kent County, Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 27, 2020, 7:25 PM EDT for Caroline County, Maryland; Kent County, Sussex County, Delaware. It was in force for 35 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 27, 2020, 7:25 PM EDT (23:25 UTC)
Expired
Aug 27, 2020, 8:00 PM EDT
In force
35 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

The radar

The Dover AFB radar (KDOX), 26 km from the middle of the area, began a volume at 23:27 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

Wallops Is Stn, VA (KWAL), launched 12:00Z, 11.4 hours before the alert went out and 105 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, Wallops Is Stn, VA at 12:00Z on 2020-08-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 553 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, Wallops Is Stn, VA at 12:00Z on 2020-08-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 77 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
553 J/kg
Mixed-layer CIN
-94 J/kg
Mixed-layer LCL
1289 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
77 m²/s²
0-3 km storm-relative helicity
197 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.5

Open this sounding in Storm Lab

The text

As transmitted.

950 
WUUS51 KPHI 272325
SVRPHI
DEC001-005-MDC011-280000-
/O.NEW.KPHI.SV.W.0263.200827T2325Z-200828T0000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
725 PM EDT Thu Aug 27 2020

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Central Sussex County in southern Delaware...
  Southern Kent County in central Delaware...
  Caroline County in eastern Maryland...

* Until 800 PM EDT.

* At 724 PM EDT, a cluster of severe thunderstorms were located near 
  Sandtown, or 14 miles southwest of Dover, moving east at 45 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Georgetown, Milford, Seaford, Denton, Harrington, Camden, Lewes,
  Federalsburg, Milton, Bridgeville, Greensboro, Ridgely, Ellendale,
  Bowers, Goldsboro, Woodside, Viola, Henlopen Acres, Smithville and
  Rising Sun-Lebanon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

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

&&

LAT...LON 3865 7571 3879 7593 3881 7590 3882 7590
      3884 7593 3886 7592 3888 7595 3889 7594
      3893 7595 3913 7563 3902 7508 3861 7503
TIME...MOT...LOC 2324Z 272DEG 39KT 3899 7569 

HAIL...<.75IN
WIND...60MPH
 
$$

NC
2 follow-up statements
042 
WWUS51 KPHI 272341
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
741 PM EDT Thu Aug 27 2020

MDC011-272351-
/O.CAN.KPHI.SV.W.0263.000000T0000Z-200828T0000Z/
Caroline MD-
741 PM EDT Thu Aug 27 2020

...THE SEVERE THUNDERSTORM WARNING FOR CAROLINE COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 3881 7572 3887 7571 3901 7564 3910 7545
      3902 7508 3864 7505
TIME...MOT...LOC 2341Z 272DEG 39KT 3898 7544 

$$

DEC001-005-280000-
/O.CON.KPHI.SV.W.0263.000000T0000Z-200828T0000Z/
Sussex DE-Kent DE-
741 PM EDT Thu Aug 27 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR NORTHERN SUSSEX AND SOUTHERN KENT COUNTIES...

At 741 PM EDT, a severe thunderstorm was located near Milford, or 12
miles south of Dover, moving east at 45 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Milford, Harrington, Lewes, Milton, Ellendale, Bowers, Viola,
Henlopen Acres, Cape Henlopen State Park, Big Stone Beach,
Andrewsville, Felton, Greenwood, Frederica, Houston, Dewey Beach,
Magnolia, Farmington and Riverview.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

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

&&

LAT...LON 3881 7572 3887 7571 3901 7564 3910 7545
      3902 7508 3864 7505
TIME...MOT...LOC 2341Z 272DEG 39KT 3898 7544 

HAIL...<.75IN
WIND...60MPH
 
$$

NC
351 
WWUS51 KPHI 272357
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
757 PM EDT Thu Aug 27 2020

DEC001-005-280007-
/O.EXP.KPHI.SV.W.0263.000000T0000Z-200828T0000Z/
Sussex DE-Kent DE-
757 PM EDT Thu Aug 27 2020

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN SUSSEX AND SOUTHERN
KENT COUNTIES WILL EXPIRE AT 800 PM EDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.  However gusty
winds are still possible with this thunderstorm.

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 3881 7572 3887 7571 3901 7564 3910 7545
      3902 7508 3864 7505
TIME...MOT...LOC 2357Z 272DEG 39KT 3897 7525 

$$

NC

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 27, 6:25 PM EDTSevere Thunderstorm WarningPHIKent, Queen Anne's, Talbot50 min
Aug 27, 7:12 PM EDTSpecial Weather StatementPHICaroline48 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2020Severe Thunderstorm Warnings in Maryland, 2020Every severe thunderstorm warning in 2020

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.