Alert archive / Delaware / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 72, NWS Philadelphia/Mount Holly

June 9, 2021Kent County, Sussex County, Delaware; Caroline County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 9, 2021, 4:37 PM EDT for Kent County, Sussex County, Delaware; Caroline County, Maryland. It was in force for 27 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
Jun 9, 2021, 4:37 PM EDT (20:37 UTC)
Expired
Jun 9, 2021, 5:04 PM EDT
In force
27 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), 29 km from the middle of the area, began a volume at 20:37 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, 8.6 hours before the alert went out and 81 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 2021-06-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 795 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 2021-06-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 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
795 J/kg
Mixed-layer CIN
-87 J/kg
Mixed-layer LCL
967 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
31 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

066 
WUUS51 KPHI 092037
SVRPHI
DEC001-005-MDC011-092115-
/O.NEW.KPHI.SV.W.0072.210609T2037Z-210609T2115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
437 PM EDT Wed Jun 9 2021

The National Weather Service in Mount Holly NJ has issued a

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

* Until 515 PM EDT.

* At 436 PM EDT, a severe thunderstorm was located near Seaford, or 9
  miles east of Hurlock, moving southwest 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...
  Seaford, Denton, Laurel, Harrington, Federalsburg, Bridgeville,
  Delmar, Smithville, Agner, Sycamore, Andrewsville, Blades,
  Greenwood, Bethel and Farmington.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3846 7560 3846 7569 3864 7571 3869 7577
      3868 7578 3868 7580 3887 7587 3893 7555
      3857 7539 3845 7555
TIME...MOT...LOC 2036Z 047DEG 24KT 3864 7570 

HAIL...0.75IN
WIND...60MPH
 
$$

Davis
2 follow-up statements
645 
WWUS51 KPHI 092055
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
455 PM EDT Wed Jun 9 2021

DEC001-005-MDC011-092115-
/O.CON.KPHI.SV.W.0072.000000T0000Z-210609T2115Z/
Sussex DE-Kent DE-Caroline MD-
455 PM EDT Wed Jun 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM EDT
FOR SOUTHWESTERN SUSSEX...SOUTHWESTERN KENT AND SOUTHEASTERN CAROLINE
COUNTIES...

At 454 PM EDT, a severe thunderstorm was located near Vienna, or near
Hurlock, moving southwest at 30 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...
Seaford, Laurel, Federalsburg, Bridgeville, Delmar, Agner,
Smithville, Andrewsville, Blades and Bethel.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3846 7560 3846 7569 3864 7571 3869 7577
      3868 7578 3868 7580 3884 7586 3889 7563
      3849 7550 3845 7555
TIME...MOT...LOC 2054Z 047DEG 24KT 3855 7582 

HAIL...0.75IN
WIND...60MPH
 
$$

Davis
499 
WWUS51 KPHI 092104
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
504 PM EDT Wed Jun 9 2021

DEC001-005-MDC011-092113-
/O.CAN.KPHI.SV.W.0072.000000T0000Z-210609T2115Z/
Sussex DE-Kent DE-Caroline MD-
504 PM EDT Wed Jun 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN SUSSEX...
SOUTHWESTERN KENT AND SOUTHEASTERN 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 heavy rain is
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 3846 7560 3846 7569 3864 7571 3869 7577
      3868 7578 3868 7580 3884 7586 3889 7563
      3849 7550 3845 7555
TIME...MOT...LOC 2102Z 047DEG 24KT 3851 7588 

$$

Fitzsimmons

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 8, 8:15 PM EDTSpecial Weather StatementPHISussex45 min
Jun 9, 7:54 AM EDTRiver Flood WarningPHINew Castle5 hr
Jun 9, 1:35 PM EDTSpecial Weather StatementPHINew Castle25 min
Jun 9, 2:07 PM EDTSevere Thunderstorm WarningPHINew Castle23 min
Jun 9, 2:21 PM EDTFlash Flood WarningPHINew Castle73 min
Jun 9, 2:26 PM EDTSevere Thunderstorm WarningPHIKent64 min
Jun 9, 2:28 PM EDTSevere Thunderstorm WarningPHISussex62 min
Jun 9, 3:11 PM EDTSevere Thunderstorm WarningPHISussex64 min
Jun 9, 3:24 PM EDTAreal Flood AdvisoryPHISussex3 hr
Jun 9, 4:32 PM EDTAreal Flood AdvisoryPHISussex108 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.