Alert archive / Delaware / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 207, NWS Philadelphia/Mount Holly

August 6, 2020Kent County, New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 6, 2020, 6:49 AM EDT for Kent County, New Castle County, Delaware. It was in force for 41 min. 5 reports 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 6, 2020, 6:49 AM EDT (10:49 UTC)
Expired
Aug 6, 2020, 7:30 AM EDT
In force
41 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
1.0 in
Wind
70.0 mph

Counties Kent County, DE, New Castle County, DE

The radar

The Dover AFB radar (KDOX), 31 km from the middle of the area, began a volume at 10:52 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 6, 6:52 AM EDTTSTM WND DMG3 Nnw Felton, DEDOWNED WIRES REPORTED NEAR FELTON. TIME ESTIMATED FROM RADAR.
Aug 6, 6:58 AM EDTTSTM WND DMG2 Wsw Clayton, DESEVERAL REPORTS OF TREES AND WIRES DOWN NEAR MILLINGTON ROAD IN WESTERN KENT COUNTY. TIME ESTIMATED FROM RADAR.
Aug 6, 6:58 AM EDTTSTM WND DMG3 Sse Smyrna, DESEVERAL REPORTS OF TREES AND WIRES DOWN SOUTH OF SMYRNA EASTWARD TO THE LEIPSIC AREA. TIME ESTIMATED FROM RADAR.
Aug 6, 7:01 AM EDTTSTM WND DMGClayton, DEDOWNED TREES AND WIRES NEAR AND SOUTH OF CLAYTON. TIME ESTIMATED FROM RADAR.
Aug 6, 7:06 AM EDTTSTM WND DMG2 N Leipsic, DESEVERAL REPORTS OF DOWNED POWER LINES IN THE LEIPSIC AREA. TIME ESTIMATED FROM RADAR.

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

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 10.8 hours before the alert went out and 130 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 2020-08-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1920 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 00:00Z on 2020-08-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -6 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
1920 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
772 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
-6 m²/s²
0-3 km storm-relative helicity
20 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

699 
WUUS51 KPHI 061049
SVRPHI
DEC001-003-061130-
/O.NEW.KPHI.SV.W.0207.200806T1049Z-200806T1130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
649 AM EDT Thu Aug 6 2020

The National Weather Service in Mount Holly NJ has issued a

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

* Until 730 AM EDT.

* At 648 AM EDT, severe thunderstorms were located along a line
  extending from near Green Spring to near Sandtown, moving east at
  25 mph.

  HAZARD...70 mph wind gusts and quarter size hail.

  SOURCE...Law enforcement.

  IMPACT...Minor damage to vehicles is possible. Expect considerable 
           tree damage. Wind damage is also likely to mobile homes, 
           roofs, and outbuildings.

* Locations impacted include...
  Dover, Smyrna, Milford, Harrington, Camden, Clayton, Cheswold,
  Bowers, Woodside, Viola, Hartly, Rising Sun-Lebanon, Woodland
  Beach, Hazlettville, Delaney Corner, Dover Base Housing, Dover
  Speedway, Sandtown, Green Spring and Rising Sun.

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 these storms. Move indoors
immediately. Remember, if you can hear thunder, you are close enough
to be struck by lightning.

&&

LAT...LON 3940 7577 3944 7549 3898 7523 3895 7532
      3896 7539 3892 7541 3890 7549 3890 7572
TIME...MOT...LOC 1048Z 262DEG 21KT 3934 7570 3899 7569 

HAIL...1.00IN
WIND...70MPH
 
$$

CMS
2 follow-up statements
015 
WWUS51 KPHI 061106
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
706 AM EDT Thu Aug 6 2020

DEC001-003-061130-
/O.CON.KPHI.SV.W.0207.000000T0000Z-200806T1130Z/
New Castle DE-Kent DE-
706 AM EDT Thu Aug 6 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 AM EDT
FOR SOUTHWESTERN NEW CASTLE AND KENT COUNTIES...

At 705 AM EDT, severe thunderstorms were located along a line
extending from near Green Spring to near Viola, moving east at 25
mph.

HAZARD...70 mph wind gusts and quarter size hail.

SOURCE...Law enforcement. Reports of wires down have been received 
         near and south of Townsend.

IMPACT...Minor damage to vehicles is possible. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings.

Locations impacted include...
Dover, Smyrna, Milford, Harrington, Camden, Clayton, Cheswold,
Bowers, Woodside, Viola, Hartly, Rising Sun-Lebanon, Woodland Beach,
Hazlettville, Delaney Corner, Dover Base Housing, Dover Speedway,
Sandtown, Green Spring and Rising Sun.

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 these storms.
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 3940 7577 3944 7549 3898 7523 3895 7532
      3896 7539 3892 7541 3890 7549 3890 7572
TIME...MOT...LOC 1105Z 262DEG 21KT 3935 7558 3900 7557 

HAIL...1.00IN
WIND...70MPH
 
$$

CMS
000 
WWUS51 KPHI 061125
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
725 AM EDT Thu Aug 6 2020

DEC001-003-061135-
/O.EXP.KPHI.SV.W.0207.000000T0000Z-200806T1130Z/
New Castle DE-Kent DE-
725 AM EDT Thu Aug 6 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN NEW CASTLE AND
KENT COUNTIES WILL EXPIRE AT 730 AM EDT...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.  However, gusty 
winds and heavy rain are still possible with these thunderstorms.

LAT...LON 3940 7577 3944 7549 3898 7523 3895 7532
      3896 7539 3892 7541 3890 7549 3890 7572
TIME...MOT...LOC 1125Z 262DEG 21KT 3936 7545 3901 7544 

$$

CMS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 6, 3:37 AM EDTFlash Flood WatchPHIKent, New Castle, Sussex44 hr
Aug 6, 6:13 AM EDTSevere Thunderstorm WarningPHIKent, New Castle, Sussex62 min
Aug 6, 6:43 AM EDTAreal Flood AdvisoryPHIKent, New Castle3 hr
Aug 6, 7:13 AM EDTFlash Flood WarningPHIKent, New Castle3 hr
Aug 6, 7:13 AM EDTSevere Thunderstorm WarningPHIKent, Sussex47 min
Aug 6, 7:18 AM EDTSevere Thunderstorm WarningPHIKent, New Castle42 min
Aug 6, 7:46 AM EDTSpecial Weather StatementPHISussex29 min
Aug 6, 8:16 AM EDTSevere Thunderstorm WarningPHISussex44 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.