Alert archive / Delaware / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 233, NWS Philadelphia/Mount Holly

August 12, 2020Kent County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 12, 2020, 2:38 PM EDT for Kent County, Delaware. It was in force for 52 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 12, 2020, 2:38 PM EDT (18:38 UTC)
Expired: Aug 12, 2020, 3:30 PM EDT
In force: 52 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Kent County, DE

The radar

The Dover AFB radar (KDOX), 18 km from the middle of the area, began a volume at 18:37 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, 6.6 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1590 J/kg
Mixed-layer CIN: -21 J/kg
Mixed-layer LCL: 729 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 3 m²/s²
0-3 km storm-relative helicity: 17 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

035 
WUUS51 KPHI 121838
SVRPHI
DEC001-121930-
/O.NEW.KPHI.SV.W.0233.200812T1838Z-200812T1930Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
238 PM EDT Wed Aug 12 2020

The National Weather Service in Mount Holly NJ has issued a

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

* Until 330 PM EDT.

* At 238 PM EDT, a severe thunderstorm was located near Viola, or 7
  miles south of Dover, and is nearly stationary.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Dover, Milford, Harrington, Camden, Bowers, Woodside, Viola, Rising
  Sun-Lebanon, Rising Sun, Hazlettville, Dover Base Housing, Wyoming,
  Felton, Frederica, Houston, Magnolia, Rodney Village, Kent Acres,
  Riverview and Highland Acres.

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.

In addition to damaging winds, frequent cloud to ground lightning is 
occurring with this storm. Move indoors immediately. Remember, if 
you can hear thunder, you are close enough to be struck by lightning.

&&

LAT...LON 3891 7573 3916 7568 3913 7542 3895 7535
      3896 7539 3893 7540 3892 7542 3891 7545
TIME...MOT...LOC 1838Z 014DEG 4KT 3905 7551 

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

Gorse

2 follow-up statements

335 
WWUS51 KPHI 121857
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
257 PM EDT Wed Aug 12 2020

DEC001-121930-
/O.CON.KPHI.SV.W.0233.000000T0000Z-200812T1930Z/
Kent DE-
257 PM EDT Wed Aug 12 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 330 PM EDT
FOR SOUTHERN KENT COUNTY...

At 257 PM EDT, a severe thunderstorm was located near Viola, or 12
miles south of Dover, moving south at 10 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Dover, Milford, Harrington, Camden, Bowers, Woodside, Viola, Rising
Sun-Lebanon, Rising Sun, Hazlettville, Dover Base Housing, Wyoming,
Felton, Frederica, Houston, Magnolia, Rodney Village, Kent Acres,
Riverview and Highland Acres.

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.

Frequent cloud to ground lightning is occurring with this storm. Move
indoors immediately. Lightning is one of nature's leading killers.
Remember, if you can hear thunder, you are close enough to be struck
by lightning.

&&

LAT...LON 3891 7573 3916 7568 3913 7542 3895 7535
      3896 7539 3893 7540 3892 7542 3891 7545
TIME...MOT...LOC 1857Z 018DEG 9KT 3898 7554 

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

Gorse

274 
WWUS51 KPHI 121916
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
316 PM EDT Wed Aug 12 2020

DEC001-121930-
/O.CON.KPHI.SV.W.0233.000000T0000Z-200812T1930Z/
Kent DE-
316 PM EDT Wed Aug 12 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 330 PM EDT
FOR SOUTHERN KENT COUNTY...

At 316 PM EDT, a severe thunderstorm was located over Harrington, or
13 miles south of Dover, and is nearly stationary.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Milford, Harrington, Bowers, Viola, Felton, Frederica, Houston,
Riverview and Woodside East.

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 3891 7573 3906 7570 3906 7539 3895 7535
      3896 7539 3893 7540 3892 7542 3891 7545
TIME...MOT...LOC 1916Z 014DEG 4KT 3896 7555 

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

Gorse

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 12, 12:43 PM EDT	Areal Flood Advisory	PHI	New Castle	3 hr
Aug 12, 12:55 PM EDT	Areal Flood Advisory	PHI	Kent, New Castle	3 hr
Aug 12, 12:55 PM EDT	Special Weather Statement	PHI	Kent	35 min
Aug 12, 1:06 PM EDT	Flash Flood Warning	PHI	Kent, New Castle	3 hr
Aug 12, 1:37 PM EDT	Areal Flood Advisory	PHI	New Castle	3 hr
Aug 12, 1:54 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	51 min
Aug 12, 2:40 PM EDT	Flash Flood Warning	PHI	New Castle	3 hr
Aug 12, 3:06 PM EDT	Areal Flood Advisory	PHI	Kent, Sussex	3 hr
Aug 12, 3:15 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	45 min
Aug 12, 3:20 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	29 min
Aug 12, 3:31 PM EDT	Flash Flood Warning	PHI	Kent	3 hr
Aug 12, 3:46 PM EDT	Flash Flood Warning	PHI	Kent, Sussex	3 hr
Aug 12, 4:00 PM EDT	Special Weather Statement	PHI	Kent	30 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2020 Every 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.