Alert archive / Delaware / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 271, NWS Philadelphia/Mount Holly

August 28, 2020Kent County, New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 28, 2020, 3:21 PM EDT for Kent County, New Castle County, Delaware. It was in force for 24 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 28, 2020, 3:21 PM EDT (19:21 UTC)
Expired
Aug 28, 2020, 3:45 PM EDT
In force
24 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
2.0 in
Wind
70.0 mph

Counties Kent County, DE, New Castle County, DE

The radar

The Dover AFB radar (KDOX), 49 km from the middle of the area, began a volume at 19:23 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.

What was reported inside it

TimeReportWhereRemark
Aug 28, 3:25 PM EDTTSTM WND DMGWoodland Beach, DEDOWNED TREE LIMBS AND POWER LINES REPORTED IN THE WOODLAND BEACH AREA. TIME ESTIMATED FROM RADAR.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Aug 28, 1:37 PM EDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 7.4 hours before the alert went out and 148 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 2020-08-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 264 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 2020-08-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 44 square meters per square second.193958Sfc1 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
264 J/kg
Mixed-layer CIN
-171 J/kg
Mixed-layer LCL
1367 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
44 m²/s²
0-3 km storm-relative helicity
104 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

594 
WUUS51 KPHI 281921
SVRPHI
DEC001-003-281945-
/O.NEW.KPHI.SV.W.0271.200828T1921Z-200828T1945Z/

BULLETIN - EAS ACTIVATION REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
321 PM EDT Fri Aug 28 2020

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  South central New Castle County in northern Delaware...
  Northeastern Kent County in central Delaware...

* Until 345 PM EDT.

* At 320 PM EDT, a severe thunderstorm was located near Smyrna, or 10
  miles north of Dover, moving east at 30 mph.

  HAZARD...Two inch hail and 70 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           considerable tree damage. Wind damage is also likely to 
           mobile homes, roofs, and outbuildings.

* Locations impacted include...
  Dover, Smyrna, Clayton, Cheswold, Woodland Beach, Little Creek and
  Leipsic.

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.

Prepare immediately for large hail and damaging winds. People outside
should move immediately to shelter inside a strong building. Stay
away from windows.

In addition to large hail and 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 3926 7565 3940 7555 3936 7547 3926 7539
      3917 7538 3911 7540
TIME...MOT...LOC 1920Z 290DEG 26KT 3931 7555 

HAIL...2.00IN
WIND...70MPH
 
$$

Staarmann
2 follow-up statements
370 
WWUS51 KPHI 281934
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
334 PM EDT Fri Aug 28 2020

DEC003-281943-
/O.CAN.KPHI.SV.W.0271.000000T0000Z-200828T1945Z/
New Castle DE-
334 PM EDT Fri Aug 28 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL NEW CASTLE
COUNTY IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
central Delaware.

LAT...LON 3934 7545 3926 7539 3917 7538 3911 7540
      3923 7561 3925 7563 3926 7563
TIME...MOT...LOC 1933Z 293DEG 25KT 3926 7546 

$$

DEC001-281945-
/O.CON.KPHI.SV.W.0271.000000T0000Z-200828T1945Z/
Kent DE-
334 PM EDT Fri Aug 28 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM EDT
FOR NORTHEASTERN KENT COUNTY...

At 333 PM EDT, a severe thunderstorm was located near Woodland Beach,
or 7 miles northeast of Dover, moving southeast at 30 mph.

HAZARD...Two inch hail and 70 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect 
         considerable tree damage. Wind damage is also likely to 
         mobile homes, roofs, and outbuildings.

Locations impacted include...
Dover, Cheswold, Little Creek and Leipsic. 

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.

Prepare immediately for large hail and damaging winds. People outside
should seek shelter inside a well-built structure and away from
windows.

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 3934 7545 3926 7539 3917 7538 3911 7540
      3923 7561 3925 7563 3926 7563
TIME...MOT...LOC 1933Z 293DEG 25KT 3926 7546 

HAIL...2.00IN
WIND...70MPH
 
$$

Staarmann
242 
WWUS51 KPHI 281942
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
342 PM EDT Fri Aug 28 2020

DEC001-281952-
/O.EXP.KPHI.SV.W.0271.000000T0000Z-200828T1945Z/
Kent DE-
342 PM EDT Fri Aug 28 2020

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN KENT COUNTY WILL
EXPIRE AT 345 PM EDT...
        
The storm which prompted the warning has moved out of the area over 
Delaware Bay. Therefore, the warning will be allowed to expire.

A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
central Delaware.

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 3934 7545 3926 7539 3917 7538 3911 7540
      3923 7561 3925 7563 3926 7563
TIME...MOT...LOC 1942Z 290DEG 25KT 3924 7540 

$$

Staarmann

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 28, 1:53 PM EDTSevere Thunderstorm WarningPHINew Castle52 min
Aug 28, 2:40 PM EDTSevere Thunderstorm WarningPHIKent, New Castle50 min
Aug 28, 3:15 PM EDTSpecial Weather StatementPHINew Castle30 min
Aug 28, 3:41 PM EDTSpecial Weather StatementPHINew Castle34 min
Aug 28, 3:52 PM EDTSevere Thunderstorm WarningPHINew Castle53 min
Aug 28, 4:01 PM EDTSevere Thunderstorm WarningPHINew Castle44 min
Aug 28, 4:39 PM EDTSevere Thunderstorm WarningPHIKent, New Castle66 min
Aug 28, 5:40 PM EDTSpecial Weather StatementPHIKent35 min
Aug 28, 6:17 PM EDTSevere Thunderstorm WarningPHIKent, Sussex43 min
Aug 28, 7:53 PM EDTSpecial Weather StatementPHISussex37 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2020Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.