Alert archive / Delaware / Tornado Warnings in 2020

Tornado Warning 13, NWS Philadelphia/Mount Holly

August 4, 2020Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this tornado warning at Aug 4, 2020, 7:39 AM EDT for Sussex County, Delaware. It was in force for 36 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, 7:39 AM EDT (11:39 UTC)
Expired: Aug 4, 2020, 8:15 AM EDT
In force: 36 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.0 in

County Sussex County, DE

The radar

The Dover AFB radar (KDOX), 22 km from the middle of the area, began a volume at 11:42 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.

Issued	Product	Office	Lasted
Aug 4, 2:26 AM EDT	Tornado Watch	SPC	9 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 11.7 hours before the alert went out and 79 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: 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.

106 
WFUS51 KPHI 041139
TORPHI
DEC005-041215-
/O.NEW.KPHI.TO.W.0013.200804T1139Z-200804T1215Z/

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

The National Weather Service in Mount Holly NJ has issued a

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

* Until 815 AM EDT.
    
* At 739 AM EDT, a severe thunderstorm capable of producing a tornado
  was located near Parsonsburg, or 7 miles northeast of Salisbury,
  moving north 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...
  Georgetown, Laurel, Delmar, Ellendale, Sycamore and Greenwood. 

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 3882 7559 3880 7533 3845 7540 3845 7558
      3846 7558
TIME...MOT...LOC 1139Z 185DEG 45KT 3845 7549 

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

$$

SFJ

2 follow-up statements

963 
WWUS51 KPHI 041148
SVSPHI

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

DEC005-041215-
/O.CON.KPHI.TO.W.0013.000000T0000Z-200804T1215Z/
Sussex DE-
748 AM EDT Tue Aug 4 2020

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 815 AM EDT FOR
SOUTHWESTERN SUSSEX COUNTY...
    
At 748 AM EDT, a severe thunderstorm capable of producing a tornado
was located over Sycamore, or 9 miles southwest 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, Laurel, Ellendale, Sycamore and Greenwood. 

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 3882 7559 3880 7533 3850 7539 3850 7558
TIME...MOT...LOC 1148Z 182DEG 47KT 3859 7549 

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

$$

SFJ

710 
WWUS51 KPHI 041207
SVSPHI

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

DEC005-041217-
/O.EXP.KPHI.TO.W.0013.000000T0000Z-200804T1215Z/
Sussex DE-
807 AM EDT Tue Aug 4 2020

...THE TORNADO WARNING FOR SOUTHWESTERN SUSSEX COUNTY WILL EXPIRE AT
815 AM EDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning will be allowed to expire.

A Tornado Watch remains in effect until noon EDT for southern
Delaware.

LAT...LON 3882 7559 3880 7533 3850 7539 3850 7558
TIME...MOT...LOC 1207Z 185DEG 45KT 3881 7547 

$$

SFJ

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 4, 4:50 AM EDT	Tornado Warning	PHI	Sussex	25 min
Aug 4, 5:17 AM EDT	Areal Flood Advisory	PHI	New Castle	4 hr
Aug 4, 7:28 AM EDT	Flash Flood Warning	PHI	New Castle	3 hr
Aug 4, 7:51 AM EDT	Tornado Warning	PHI	Sussex	24 min
Aug 4, 8:15 AM EDT	Tornado Warning	PHI	Kent	45 min
Aug 4, 8:18 AM EDT	Tornado Warning	PHI	Sussex	27 min
Aug 4, 8:27 AM EDT	Tornado Warning	PHI	Kent	33 min
Aug 4, 8:56 AM EDT	Tornado Warning	PHI	Kent, New Castle	34 min
Aug 4, 8:58 AM EDT	Flash Flood Warning	PHI	Kent, New Castle, Sussex	3 hr
Aug 4, 9:06 AM EDT	River Flood Warning	PHI	New Castle	11 hr
Aug 4, 9:23 AM EDT	Flash Flood Warning	PHI	New Castle	4 hr
Aug 4, 9:23 AM EDT	Tornado Warning Tornado observed	PHI	New Castle	22 min
Aug 4, 10:02 AM EDT	Flash Flood Warning	PHI	New Castle	4 hr
Aug 4, 10:38 AM EDT	River Flood Warning	PHI	New Castle	14 hr
Aug 4, 12:27 PM EDT	River Flood Warning	PHI	New Castle	10 hr
Aug 4, 12:48 PM EDT	River Flood Warning	PHI	New Castle	24 hr
Aug 4, 1:59 PM EDT	Areal Flood Warning	PHI	New Castle	9 hr

Nearby

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