Alert archive / Delaware / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 147, NWS Philadelphia/Mount Holly

July 6, 2020Kent County, Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 6, 2020, 9:25 PM EDT for Kent County, Sussex County, Delaware. It was in force for 24 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 6, 2020, 9:25 PM EDT (01:25 UTC)
Expired: Jul 6, 2020, 9:49 PM EDT
In force: 24 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

The radar

The Dover AFB radar (KDOX), 20 km from the middle of the area, began a volume at 01:24 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.

Issued	Product	Office	Lasted
Jul 6, 1:38 PM EDT	Severe Thunderstorm Watch	SPC	9 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 1.4 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-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: 1831 J/kg
Mixed-layer CIN: -67 J/kg
Mixed-layer LCL: 1086 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 64 m²/s²
0-3 km storm-relative helicity: 74 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 4.1

Open this sounding in Storm Lab

The text

As transmitted.

298 
WUUS51 KPHI 070125
SVRPHI
DEC001-005-070230-
/O.NEW.KPHI.SV.W.0147.200707T0125Z-200707T0230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
925 PM EDT Mon Jul 6 2020

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Sussex County in southern Delaware...
  Southeastern Kent County in central Delaware...

* Until 1030 PM EDT.

* At 923 PM EDT, severe thunderstorms were located along a line
  extending from near Milford to Milton to Delmar, moving southeast
  at 20 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Georgetown, Milford, Seaford, Millsboro, Laurel, Lewes, Milton,
  Selbyville, Bridgeville, Delmar, Dagsboro, Millville, Ellendale,
  Henlopen Acres, Gumboro, Cape Henlopen State Park, Sycamore, Big
  Stone Beach, Long Neck and Ocean View.

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 large hail and damaging winds, frequent cloud to
ground lightning is occurring with these storms. Move indoors
immediately. Remember, if you can hear thunder, you are close enough
to be struck by lightning.

&&

LAT...LON 3846 7569 3850 7570 3861 7571 3879 7558
      3902 7550 3905 7532 3887 7519 3880 7502
      3863 7498 3845 7503 3846 7505 3845 7505
TIME...MOT...LOC 0123Z 294DEG 17KT 3897 7540 3878 7528 3842 7557 

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

Robertson

1 follow-up statement

141 
WWUS51 KPHI 070149
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
949 PM EDT Mon Jul 6 2020

DEC001-005-070157-
/O.CAN.KPHI.SV.W.0147.000000T0000Z-200707T0230Z/
Sussex DE-Kent DE-
949 PM EDT Mon Jul 6 2020

...THE SEVERE THUNDERSTORM WARNING FOR SUSSEX AND SOUTHEASTERN KENT
COUNTIES IS CANCELLED...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning has been cancelled.  However gusty winds and
heavy rain are still possible with these thunderstorms.

A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
central and southern Delaware.

LAT...LON 3846 7569 3850 7570 3861 7571 3879 7558
      3902 7550 3905 7532 3887 7519 3880 7502
      3863 7498 3845 7503 3846 7505 3845 7505
TIME...MOT...LOC 0145Z 294DEG 17KT 3893 7527 3874 7516 3838 7545 

$$

Robertson

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 6, 8:21 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	39 min
Jul 6, 8:41 PM EDT	Areal Flood Advisory	PHI	Kent, Sussex	2 hr
Jul 6, 8:53 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	37 min
Jul 6, 9:49 PM EDT	Special Weather Statement	PHI	Sussex	56 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.