Alert archive / Maryland / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 239, NWS Philadelphia/Mount Holly

August 9, 2021Caroline County, Queen Anne's County, Maryland; Kent County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 9, 2021, 5:12 PM EDT for Caroline County, Queen Anne's County, Maryland; Kent County, Delaware. It was in force for 20 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 9, 2021, 5:12 PM EDT (21:12 UTC)
Expired
Aug 9, 2021, 5:32 PM EDT
In force
20 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Kent County, DE, Caroline County, MD, Queen Anne's County, MD

The radar

The Dover AFB radar (KDOX), 35 km from the middle of the area, began a volume at 21:11 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, 9.2 hours before the alert went out and 128 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 2021-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 927 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 2021-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 25 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
927 J/kg
Mixed-layer CIN
-47 J/kg
Mixed-layer LCL
869 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
25 m²/s²
0-3 km storm-relative helicity
18 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

473 
WUUS51 KPHI 092112
SVRPHI
DEC001-MDC011-035-092200-
/O.NEW.KPHI.SV.W.0239.210809T2112Z-210809T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
512 PM EDT Mon Aug 9 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  West central Kent County in central Delaware...
  East central Queen Anne's County in northeastern Maryland...
  Northeastern Caroline County in eastern Maryland...

* Until 600 PM EDT.

* At 512 PM EDT, a severe thunderstorm was located over Goldsboro, or
  14 miles east of Centerville, moving northeast at 10 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Minor damage to vehicles is possible. Wind damage to 
           roofs, siding, trees, and power lines is possible.

* Locations impacted include...
  Goldsboro, Woodside, Viola, Hartly, Hazlettville, Sandtown, Felton,
  Kenton, Henderson, Marydel, Templeville and Riverview.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3898 7579 3908 7587 3925 7568 3896 7550
TIME...MOT...LOC 2112Z 229DEG 7KT 3907 7579 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

SFJ
1 follow-up statement
813 
WWUS51 KPHI 092132
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
532 PM EDT Mon Aug 9 2021

DEC001-MDC011-035-092141-
/O.CAN.KPHI.SV.W.0239.000000T0000Z-210809T2200Z/
Kent DE-Queen Anne's MD-Caroline MD-
532 PM EDT Mon Aug 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL KENT...EAST
CENTRAL QUEEN ANNE'S AND NORTHEASTERN CAROLINE COUNTIES IS
CANCELLED...
                
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 has been cancelled.  However gusty winds are
still possible with this thunderstorm.

LAT...LON 3898 7579 3908 7587 3925 7568 3896 7550
TIME...MOT...LOC 2129Z 229DEG 7KT 3910 7575 

$$

SFJ

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 9, 2:41 PM EDTAreal Flood AdvisoryPHICaroline, Kent, Queen Anne's3 hr
Aug 9, 4:35 PM EDTSevere Thunderstorm WarningPHICaroline40 min
Aug 9, 4:59 PM EDTFlash Flood WarningPHICaroline, Queen Anne's79 min
Aug 9, 2:10 PM EDTSpecial Weather StatementPHISussex50 min
Aug 9, 3:01 PM EDTFlash Flood WarningPHIKent, Sussex2 hr
Aug 9, 3:43 PM EDTExcessive Heat WatchPHINew Castle12 hr
Aug 9, 4:36 PM EDTAreal Flood AdvisoryPHINew Castle104 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2021Severe Thunderstorm Warnings in Delaware, 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.