Alert archive / Delaware / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 283, NWS Philadelphia/Mount Holly

August 29, 2020Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 29, 2020, 2:38 PM EDT for Sussex County, Delaware. It was in force for 26 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 29, 2020, 2:38 PM EDT (18:38 UTC)
Expired: Aug 29, 2020, 3:04 PM EDT
In force: 26 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

County Sussex County, DE

The radar

The Dover AFB radar (KDOX), 26 km from the middle of the area, began a volume at 18:39 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 76 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: 886 J/kg
Mixed-layer CIN: -24 J/kg
Mixed-layer LCL: 555 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 177 m²/s²
0-3 km storm-relative helicity: 186 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 48.8

Open this sounding in Storm Lab

The text

As transmitted.

913 
WUUS51 KPHI 291838
SVRPHI
DEC005-291930-
/O.NEW.KPHI.SV.W.0283.200829T1838Z-200829T1930Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
238 PM EDT Sat Aug 29 2020

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southwestern Sussex County in southern Delaware...

* Until 330 PM EDT.

* At 237 PM EDT, a severe thunderstorm was located near Sharptown, or
  10 miles east of Hurlock, moving east at 30 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Georgetown, Seaford, Millsboro, Laurel, Sycamore, Blades and
  Bethel.

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.

To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in Mount Holly NJ.

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

&&

LAT...LON 3862 7570 3874 7536 3854 7527 3851 7570
TIME...MOT...LOC 1837Z 254DEG 25KT 3857 7568 

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

MPS

1 follow-up statement

304 
WWUS51 KPHI 291904
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
304 PM EDT Sat Aug 29 2020

DEC005-291914-
/O.CAN.KPHI.SV.W.0283.000000T0000Z-200829T1930Z/
Sussex DE-
304 PM EDT Sat Aug 29 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN SUSSEX COUNTY 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.

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 3862 7570 3874 7536 3854 7527 3851 7570
TIME...MOT...LOC 1902Z 254DEG 25KT 3862 7544 

$$

MPS

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 29, 12:58 AM EDT	Special Weather Statement	PHI	Sussex	32 min
Aug 29, 8:16 AM EDT	Areal Flood Advisory	PHI	Kent, Sussex	4 hr
Aug 29, 2:02 PM EDT	Areal Flood Advisory	PHI	Kent, Sussex	3 hr
Aug 29, 2:49 PM EDT	Special Weather Statement	PHI	New Castle	41 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.