Alert archive / Delaware / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 263, NWS Philadelphia/Mount Holly

August 13, 2021Kent County, Sussex County, Delaware; Caroline County, Queen Anne's County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 13, 2021, 7:12 PM EDT for Kent County, Sussex County, Delaware; Caroline County, Queen Anne's County, Maryland. It was in force for 33 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 13, 2021, 7:12 PM EDT (23:12 UTC)
Expired
Aug 13, 2021, 7:45 PM EDT
In force
33 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, Queen Anne's County, MD

The radar

The Dover AFB radar (KDOX), 24 km from the middle of the area, began a volume at 23:15 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 13, 1:11 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 11.2 hours before the alert went out and 117 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 2021-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 809 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 2021-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 square meters per square second.1939Sfc1 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
809 J/kg
Mixed-layer CIN
-190 J/kg
Mixed-layer LCL
1510 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
32 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

390 
WUUS51 KPHI 132312
SVRPHI
DEC001-005-MDC011-035-132345-
/O.NEW.KPHI.SV.W.0263.210813T2312Z-210813T2345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
712 PM EDT Fri Aug 13 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  North central Sussex County in southern Delaware...
  Kent County in central Delaware...
  Eastern Queen Anne's County in northeastern Maryland...
  Northeastern Caroline County in eastern Maryland...

* Until 745 PM EDT.

* At 712 PM EDT, a severe thunderstorm was located over Sandtown, or
  12 miles southwest of Dover, moving east at 25 mph.

  HAZARD...60 mph wind gusts and penny size hail.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Dover, Milford, Denton, Harrington, Camden, Greensboro, Bowers,
  Goldsboro, Woodside, Viola, Hartly, Rising Sun-Lebanon,
  Hazlettville, Dover Base Housing, Dover Speedway, Sandtown,
  Andrewsville, Rising Sun, Wyoming and Felton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3887 7589 3921 7578 3918 7535 3891 7533
      3887 7557 3884 7572
TIME...MOT...LOC 2312Z 270DEG 22KT 3905 7571 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

NC
1 follow-up statement
780 
WWUS51 KPHI 132331
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
731 PM EDT Fri Aug 13 2021

MDC011-035-132340-
/O.CAN.KPHI.SV.W.0263.000000T0000Z-210813T2345Z/
Queen Anne's MD-Caroline MD-
731 PM EDT Fri Aug 13 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN QUEEN ANNE'S AND
NORTHEASTERN CAROLINE COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area.  Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
eastern Maryland.

LAT...LON 3921 7575 3918 7535 3891 7533 3884 7573
TIME...MOT...LOC 2330Z 270DEG 22KT 3905 7556 

$$

DEC001-005-132345-
/O.CON.KPHI.SV.W.0263.000000T0000Z-210813T2345Z/
Sussex DE-Kent DE-
731 PM EDT Fri Aug 13 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT
FOR NORTH CENTRAL SUSSEX AND KENT COUNTIES...

At 730 PM EDT, a severe thunderstorm was located over Viola, or 7
miles south of Dover, moving east at 25 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

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

Locations impacted include...
Dover, Milford, Harrington, Camden, Bowers, Woodside, Viola, Hartly,
Rising Sun-Lebanon, Hazlettville, Dover Base Housing, Dover Speedway,
Sandtown, Andrewsville, Rising Sun, Wyoming, Felton, Frederica,
Houston and Magnolia.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3921 7575 3918 7535 3891 7533 3884 7573
TIME...MOT...LOC 2330Z 270DEG 22KT 3905 7556 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

NC

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 13, 3:21 PM EDTSpecial Weather StatementPHISussex24 min
Aug 13, 6:04 PM EDTSpecial Weather StatementPHISussex26 min
Aug 13, 6:45 PM EDTSevere Thunderstorm WarningPHIKent30 min
Aug 13, 6:47 PM EDTSpecial Weather StatementPHISussex43 min
Aug 13, 6:53 PM EDTSevere Thunderstorm WarningPHISussex37 min
Aug 13, 7:30 PM EDTSpecial Weather StatementPHISussex45 min
Aug 13, 7:43 PM EDTSevere Thunderstorm WarningPHIKent, Sussex47 min
Aug 13, 7:57 PM EDTAreal Flood AdvisoryPHIKent, Sussex93 min
Aug 13, 6:02 PM EDTSpecial Weather StatementPHIKent, Queen Anne's58 min
Aug 13, 6:29 PM EDTSpecial Weather StatementPHICaroline31 min
Aug 13, 6:29 PM EDTSevere Thunderstorm WarningPHIQueen Anne's, Talbot25 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2021Severe Thunderstorm Warnings in Maryland, 2021Every severe thunderstorm warning in 2021

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.