Alert archive / Delaware / Tornado Warnings in 2020

Tornado Warning 14, NWS Philadelphia/Mount Holly

August 4, 2020Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this tornado warning at Aug 4, 2020, 7:51 AM EDT for 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
Aug 4, 2020, 7:51 AM EDT (11:51 UTC)
Expired
Aug 4, 2020, 8:15 AM EDT
In force
24 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

County Sussex County, DE

The radar

The Dover AFB radar (KDOX), 29 km from the middle of the area, began a volume at 11:55 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.

IssuedProductOfficeLasted
Aug 4, 2:26 AM EDTTornado WatchSPC9 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 11.9 hours before the alert went out and 73 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 2020-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 920 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 2020-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 59 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
920 J/kg
Mixed-layer CIN
-35 J/kg
Mixed-layer LCL
841 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
59 m²/s²
0-3 km storm-relative helicity
75 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.5

Open this sounding in Storm Lab

The text

As transmitted.

767 
WFUS51 KPHI 041151
TORPHI
DEC005-041215-
/O.NEW.KPHI.TO.W.0014.200804T1151Z-200804T1215Z/

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

The National Weather Service in Mount Holly NJ has issued a

* Tornado Warning for...
  Central Sussex County in southern Delaware...

* Until 815 AM EDT.
    
* At 751 AM EDT, a severe thunderstorm capable of producing a tornado
  was located near Selbyville, or 13 miles northwest of Ocean City,
  moving north at 55 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...
  Georgetown, Millsboro, Lewes, Milton, Dagsboro, Gumboro and
  Frankford.

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 3846 7541 3884 7539 3884 7512 3845 7524
      3845 7538
TIME...MOT...LOC 1151Z 182DEG 47KT 3845 7530 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

SFJ
1 follow-up statement
180 
WWUS51 KPHI 041200
SVSPHI

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

DEC005-041215-
/O.CON.KPHI.TO.W.0014.000000T0000Z-200804T1215Z/
Sussex DE-
800 AM EDT Tue Aug 4 2020

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 815 AM EDT FOR CENTRAL
SUSSEX COUNTY...
    
At 800 AM EDT, a severe thunderstorm capable of producing a tornado
was located over Millsboro, or 9 miles southeast of Georgetown,
moving north at 55 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...
Georgetown, Millsboro, Lewes, Milton, Dagsboro and Frankford. 

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 3850 7540 3884 7539 3884 7512 3849 7523
      3848 7523
TIME...MOT...LOC 1200Z 182DEG 47KT 3858 7529 

TORNADO...RADAR INDICATED
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, 8:15 AM EDTTornado WarningPHIKent45 min
Aug 4, 8:18 AM EDTTornado WarningPHISussex27 min
Aug 4, 8:27 AM EDTTornado WarningPHIKent33 min
Aug 4, 8:56 AM EDTTornado WarningPHIKent, New Castle34 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

Nearby

Tornado Warnings in Delaware, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.