Alert archive / Delaware / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 201, NWS Philadelphia/Mount Holly

July 17, 2021Kent County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 17, 2021, 10:55 PM EDT for Kent County, Delaware. It was in force for 50 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
Jul 17, 2021, 10:55 PM EDT (02:55 UTC)
Expired
Jul 17, 2021, 11:45 PM EDT
In force
50 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Kent County, DE

The radar

The Dover AFB radar (KDOX), 24 km from the middle of the area, began a volume at 02:56 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
Jul 17, 1:13 PM EDTSevere Thunderstorm WatchSPC10 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 2.9 hours before the alert went out and 123 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 00:00Z on 2021-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1997 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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 00:00Z on 2021-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 59 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
1997 J/kg
Mixed-layer CIN
-29 J/kg
Mixed-layer LCL
1118 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
59 m²/s²
0-3 km storm-relative helicity
74 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

073 
WUUS51 KPHI 180255
SVRPHI
DEC001-180345-
/O.NEW.KPHI.SV.W.0201.210718T0255Z-210718T0345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
1055 PM EDT Sat Jul 17 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Kent County in central Delaware...

* Until 1145 PM EDT.

* At 1055 PM EDT, severe thunderstorms were located along a line
  extending from near Woodland Beach to Hazlettville to near
  Andrewsville, moving northeast at 25 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...
  Dover, Milford, Harrington, Camden, Cheswold, Bowers, Woodside,
  Viola, Rising Sun-Lebanon, Woodland Beach, Hazlettville, Dover Base
  Housing, Dover Speedway, Sandtown, Andrewsville, Rising Sun, Big
  Stone Beach, Wyoming, Felton and Frederica.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3909 7574 3935 7548 3930 7535 3899 7523
      3895 7535 3896 7539 3893 7540 3883 7569
      3883 7572
TIME...MOT...LOC 0255Z 235DEG 23KT 3929 7544 3909 7566 3891 7567 

HAIL...1.00IN
WIND...60MPH
 
$$

Staarmann
2 follow-up statements
565 
WWUS51 KPHI 180313
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1113 PM EDT Sat Jul 17 2021

DEC001-180345-
/O.CON.KPHI.SV.W.0201.000000T0000Z-210718T0345Z/
Kent DE-
1113 PM EDT Sat Jul 17 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1145 PM EDT
FOR EASTERN KENT COUNTY...

At 1113 PM EDT, severe thunderstorms were located along a line
extending from 6 miles southeast of Woodland Beach to Bowers to near
Milford, moving east at 30 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...
Dover, Milford, Camden, Bowers, Woodside, Rising Sun-Lebanon,
Woodland Beach, Rising Sun, Dover Base Housing, Big Stone Beach,
Dover Speedway, Wyoming, Frederica, Houston, Magnolia, Little Creek,
Leipsic, Rodney Village, Kent Acres and Riverview.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3907 7557 3930 7551 3935 7548 3930 7535
      3899 7523 3895 7535 3896 7539 3893 7540
      3888 7554
TIME...MOT...LOC 0313Z 249DEG 25KT 3926 7539 3906 7542 3893 7546 

HAIL...1.00IN
WIND...60MPH
 
$$

Staarmann
282 
WWUS51 KPHI 180327
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1127 PM EDT Sat Jul 17 2021

DEC001-180345-
/O.CON.KPHI.SV.W.0201.000000T0000Z-210718T0345Z/
Kent DE-
1127 PM EDT Sat Jul 17 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1145 PM EDT
FOR EAST CENTRAL KENT COUNTY...

At 1126 PM EDT, a severe thunderstorm was located over Big Stone
Beach, or 14 miles southeast of Dover, moving east at 20 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...
Bowers and Big Stone Beach. 

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 3905 7544 3912 7528 3899 7523 3898 7525
      3895 7534 3896 7538 3896 7539 3895 7540
TIME...MOT...LOC 0326Z 254DEG 20KT 3901 7533 

HAIL...1.00IN
WIND...60MPH
 
$$

Staarmann

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 17, 8:40 PM EDTSpecial Weather StatementPHIKent35 min
Jul 17, 9:25 PM EDTAreal Flood AdvisoryPHINew Castle2 hr
Jul 17, 9:27 PM EDTSevere Thunderstorm WarningPHINew Castle48 min
Jul 17, 9:36 PM EDTFlash Flood WarningPHINew Castle2 hr
Jul 17, 10:36 PM EDTSpecial Weather StatementPHIKent24 min
Jul 17, 10:54 PM EDTAreal Flood AdvisoryPHIKent48 min

Nearby

Severe 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.