Alert archive / Delaware / Tornado Warnings in 2020

Tornado Warning 20, NWS Philadelphia/Mount Holly

August 4, 2020Kent County, New Castle County, Delaware; Cecil County, Maryland

NWS Philadelphia/Mount Holly issued this tornado warning at Aug 4, 2020, 8:56 AM EDT for Kent County, New Castle County, Delaware; Cecil County, Maryland. It was in force for 34 min. 4 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 4, 2020, 8:56 AM EDT (12:56 UTC)
Expired
Aug 4, 2020, 9:30 AM EDT
In force
34 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.0 in

Counties Kent County, DE, New Castle County, DE, Cecil County, MD

The radar

The Dover AFB radar (KDOX), 56 km from the middle of the area, began a volume at 13:00 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 4, 8:58 AM EDTTORNADO1 W Dover, DEPICTURE ON SOCIAL MEDIA SHOWS SNAPPED POWER POLES AND SEVERAL LIMBS DOWN ON ROUTE 8 AT BENNINGTON STREET IN DOVER. TDS CONFIRMS A TORNADO OCCURRED IN THIS AREA, AND THERE ARE REPORTS OF DAMAGE FARTHER NORTH AS WELL. TIME ESTIMATED FROM RADAR.
Aug 4, 9:09 AM EDTTORNADOSmyrna, DECORRECTS PREVIOUS TORNADO REPORT FROM SMYRNA. EMERGENCY MANAGEMENT REPORTS DAMAGE FROM A TORNADO ALONG ROUTE 13 IN SYMRNA. TDS CONFIRMED TORNADO. A NEARBY DOT WIND SENSOR RECORDED A WIND GUST OF 96 MPH. TIME ESTIMATED FROM RADAR.
Aug 4, 9:09 AM EDTTORNADOSmyrna, DEEMERGENCY MANAGEMENT REPORTS DAMAGE FROM A TORNADO ALONG ROUTE 13 IN SYMRNA. TDS CONFIRMED TORNADO. TIME ESTIMATED FROM RADAR.
Aug 4, 9:19 AM EDTTORNADOTownsend, DEEMERGENCY MANAGEMENT REPORTS MULTIPLE HOMES DAMAGED BY A TORNADO ALONG DUMBUSH ROAD IN TOWNSEND. 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 4, 2:26 AM EDTTornado WatchSPC9 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 0.9 hours before the alert went out and 155 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 2020-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 472 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 2020-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 254 square meters per square second.1939587897Sfc1 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
472 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
648 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
254 m²/s²
0-3 km storm-relative helicity
273 m²/s²
Significant tornado parameter
0.8
Supercell composite
2.9

Open this sounding in Storm Lab

The text

As transmitted.

416 
WFUS51 KPHI 041256
TORPHI
DEC001-003-MDC015-041330-
/O.NEW.KPHI.TO.W.0020.200804T1256Z-200804T1330Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Mount Holly NJ
856 AM EDT Tue Aug 4 2020

The National Weather Service in Mount Holly NJ has issued a

* Tornado Warning for...
  Southwestern New Castle County in northern Delaware...
  Northwestern Kent County in central Delaware...
  Eastern Cecil County in northeastern Maryland...

* Until 930 AM EDT.
    
* At 856 AM EDT, a severe thunderstorm capable of producing a tornado
  was located over Dover Base Housing, or over Dover, moving
  northwest at 50 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* Locations impacted include...
  Dover, Middletown, Smyrna, Camden, Clayton, Cheswold, Warwick,
  Rising Sun-Lebanon, Port Penn, Dover Base Housing, Dover Speedway,
  Green Spring, Rising Sun, Townsend, Wyoming, Odessa, Kenton,
  Magnolia, 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.

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 3944 7582 3953 7557 3908 7541 3906 7554
TIME...MOT...LOC 1256Z 157DEG 44KT 3913 7551 

TORNADO...RADAR INDICATED
HAIL...0.00IN

$$

SFJ
3 follow-up statements
357 
WWUS51 KPHI 041303
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
903 AM EDT Tue Aug 4 2020

DEC001-003-MDC015-041330-
/O.CON.KPHI.TO.W.0020.000000T0000Z-200804T1330Z/
New Castle DE-Kent DE-Cecil MD-
903 AM EDT Tue Aug 4 2020

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 930 AM EDT FOR
SOUTHWESTERN NEW CASTLE...NORTHWESTERN KENT AND EASTERN CECIL
COUNTIES...
    
At 903 AM EDT, a severe thunderstorm capable of producing a tornado
was located over Cheswold, or near Dover, moving northwest at 40 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

Locations impacted include...
Dover, Middletown, Smyrna, Clayton, Cheswold, Warwick, Green Spring,
Dover Speedway, Townsend, Odessa, Kenton, Leipsic and Chambersville.

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.

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 3944 7582 3951 7562 3917 7549 3913 7559
TIME...MOT...LOC 1303Z 155DEG 35KT 3920 7557 

TORNADO...RADAR INDICATED
HAIL...0.00IN

$$

SFJ
986 
WWUS51 KPHI 041308
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
908 AM EDT Tue Aug 4 2020

DEC001-003-MDC015-041330-
/O.CON.KPHI.TO.W.0020.000000T0000Z-200804T1330Z/
New Castle DE-Kent DE-Cecil MD-
908 AM EDT Tue Aug 4 2020

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 930 AM EDT FOR
SOUTHWESTERN NEW CASTLE...NORTHWESTERN KENT AND EASTERN CECIL
COUNTIES...
        
At 908 AM EDT, a confirmed tornado was located over Smyrna, or 8
miles northwest of Dover, moving north at 50 mph.

HAZARD...Damaging tornado.

SOURCE...Radar confirmed tornado.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

Locations impacted include...
Middletown, Smyrna, Clayton, Cheswold, Warwick, Green Spring,
Townsend, Odessa, Kenton, Leipsic and Chambersville.

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.

To repeat, a tornado has been confirmed. TAKE COVER NOW! Move to a
basement or an interior room on the lowest floor of a sturdy
building. Avoid windows. If you are outdoors, in a mobile home, or in
a vehicle, move to the closest substantial shelter and protect
yourself from flying debris.

&&

LAT...LON 3944 7582 3951 7562 3922 7551 3918 7562
      3919 7564
TIME...MOT...LOC 1308Z 159DEG 43KT 3926 7559 

TORNADO...OBSERVED
HAIL...0.00IN

$$

SFJ
071 
WWUS51 KPHI 041318
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
918 AM EDT Tue Aug 4 2020

DEC001-041328-
/O.CAN.KPHI.TO.W.0020.000000T0000Z-200804T1330Z/
Kent DE-
918 AM EDT Tue Aug 4 2020

...THE TORNADO WARNING FOR NORTHWESTERN KENT COUNTY IS CANCELLED...
    
The tornadic thunderstorm which prompted the warning has !moved out 
of the warned area. Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until noon EDT for central and
northern Delaware...and northeastern Maryland.

LAT...LON 3944 7582 3951 7562 3934 7555 3932 7557
      3929 7568 3930 7572
TIME...MOT...LOC 1318Z 157DEG 44KT 3938 7565 

$$

DEC003-MDC015-041330-
/O.CON.KPHI.TO.W.0020.000000T0000Z-200804T1330Z/
New Castle DE-Cecil MD-
918 AM EDT Tue Aug 4 2020

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 930 AM EDT FOR
SOUTHWESTERN NEW CASTLE AND EASTERN CECIL COUNTIES...
        
At 918 AM EDT, a confirmed tornado was located near Green Spring, or
near Middletown, moving northwest at 50 mph.

HAZARD...Damaging tornado.

SOURCE...Radar confirmed tornado.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

Locations impacted include...
Middletown, Smyrna, Clayton, Warwick, Green Spring, Townsend, Odessa
and Chambersville.

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.

To repeat, a tornado has been confirmed. TAKE COVER NOW! Move to a
basement or an interior room on the lowest floor of a sturdy
building. Avoid windows. If you are outdoors, in a mobile home, or in
a vehicle, move to the closest substantial shelter and protect
yourself from flying debris.

&&

LAT...LON 3944 7582 3951 7562 3934 7555 3932 7557
      3929 7568 3930 7572
TIME...MOT...LOC 1318Z 157DEG 44KT 3938 7565 

TORNADO...OBSERVED
HAIL...0.00IN

$$

SFJ

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 4, 4:50 AM EDTTornado WarningPHISussex25 min
Aug 4, 5:17 AM EDTAreal Flood AdvisoryPHINew Castle4 hr
Aug 4, 7:28 AM EDTFlash Flood WarningPHINew Castle3 hr
Aug 4, 7:39 AM EDTTornado WarningPHISussex36 min
Aug 4, 7:51 AM EDTTornado WarningPHISussex24 min
Aug 4, 8:15 AM EDTTornado WarningPHIKent45 min
Aug 4, 8:18 AM EDTTornado WarningPHISussex27 min
Aug 4, 8:27 AM EDTTornado WarningPHIKent33 min
Aug 4, 8:58 AM EDTFlash Flood WarningPHIKent, New Castle, Sussex3 hr
Aug 4, 9:06 AM EDTRiver Flood WarningPHINew Castle11 hr
Aug 4, 9:23 AM EDTFlash Flood WarningPHINew Castle4 hr
Aug 4, 9:23 AM EDTTornado Warning Tornado observedPHINew Castle22 min
Aug 4, 10:02 AM EDTFlash Flood WarningPHINew Castle4 hr
Aug 4, 10:38 AM EDTRiver Flood WarningPHINew Castle14 hr
Aug 4, 12:27 PM EDTRiver Flood WarningPHINew Castle10 hr
Aug 4, 12:48 PM EDTRiver Flood WarningPHINew Castle24 hr
Aug 4, 1:59 PM EDTAreal Flood WarningPHINew Castle9 hr
Aug 4, 1:33 AM EDTAreal Flood AdvisoryPHICaroline, Kent, Queen Anne's, Talbot4 hr
Aug 4, 2:10 AM EDTFlash Flood WarningPHICaroline, Kent, Queen Anne's, Talbot4 hr
Aug 4, 6:55 AM EDTTornado WarningPHIKent, Queen Anne's35 min
Aug 4, 7:22 AM EDTTornado WarningPHIKent, Queen Anne's23 min
Aug 4, 7:50 AM EDTFlash Flood WarningPHICaroline, Kent, Queen Anne's, Talbot4 hr
Aug 4, 8:13 AM EDTTornado WarningPHIKent, Queen Anne's, Talbot26 min
Aug 4, 8:50 AM EDTFlash Flood WarningPHICaroline, Cecil, Kent, Queen Anne's4 hr

Nearby

Tornado Warnings in Delaware, 2020Tornado Warnings in Maryland, 2020Every tornado warning in 2020Tornadoes 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.