Alert archive / Delaware / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 292, NWS Philadelphia/Mount Holly

September 3, 2020Kent County, Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Sep 3, 2020, 10:14 PM EDT for Kent County, Sussex County, Delaware. It was in force for 61 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: Sep 3, 2020, 10:14 PM EDT (02:14 UTC)
Expired: Sep 3, 2020, 11:15 PM EDT
In force: 61 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

Counties Kent County, DE, Sussex County, DE

The radar

The Dover AFB radar (KDOX), 9 km from the middle of the area, began a volume at 02:15 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

Time	Report	Where	Remark
Sep 3, 10:52 PM EDT	MARINE TSTM WIND 48	2 Wnw Lewes, DE	WEATHERFLOW SITE XLEW.

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, 2.2 hours before the alert went out and 100 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: 2304 J/kg
Mixed-layer CIN: -40 J/kg
Mixed-layer LCL: 905 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 135 m²/s²
0-3 km storm-relative helicity: 178 m²/s²
Significant tornado parameter: 1.7
Supercell composite: 8.5

Open this sounding in Storm Lab

The text

As transmitted.

365 
WUUS51 KPHI 040214
SVRPHI
DEC001-005-040315-
/O.NEW.KPHI.SV.W.0292.200904T0214Z-200904T0315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
1014 PM EDT Thu Sep 3 2020

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northern Sussex County in southern Delaware...
  Southeastern Kent County in central Delaware...

* Until 1115 PM EDT.

* At 1014 PM EDT, a severe thunderstorm was located over Milford, or
  14 miles north of Georgetown, moving east at 25 mph.

  HAZARD...60 mph wind gusts and penny size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to roofs, siding, trees, and power lines is 
           possible.

* Locations impacted include...
  Georgetown, Milford, Lewes, Milton, Ellendale, Henlopen Acres, Cape
  Henlopen State Park, Long Neck, Greenwood, Houston and Dewey Beach.

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.

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

For your protection move to an interior room on the lowest floor of a
building.

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 3878 7562 3899 7550 3900 7529 3884 7520
      3881 7508 3857 7505
TIME...MOT...LOC 0214Z 288DEG 21KT 3889 7545 

TORNADO...POSSIBLE
HAIL...0.75IN
WIND...60MPH
 
$$

Staarmann

3 follow-up statements

895 
WWUS51 KPHI 040234
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1034 PM EDT Thu Sep 3 2020

DEC001-005-040315-
/O.CON.KPHI.SV.W.0292.000000T0000Z-200904T0315Z/
Sussex DE-Kent DE-
1034 PM EDT Thu Sep 3 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1115 PM EDT
FOR NORTHERN SUSSEX AND SOUTHEASTERN KENT COUNTIES...

At 1033 PM EDT, severe thunderstorms were located along a line
extending from 8 miles north of Lewes to near Milton to Georgetown, 
moving southeast at 30 mph. Another line of storms is also 
approaching the warned area from the northwest.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Georgetown, Milford, Lewes, Milton, Ellendale, Henlopen Acres, Cape
Henlopen State Park, Long Neck, Greenwood, Houston and Dewey Beach.

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.

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

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 3878 7562 3899 7550 3900 7529 3884 7520
      3881 7508 3857 7505
TIME...MOT...LOC 0233Z 296DEG 26KT 3890 7520 3878 7527 3870 7539 

TORNADO...POSSIBLE
HAIL...0.75IN
WIND...60MPH
 
$$

Staarmann

253 
WWUS51 KPHI 040259
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1059 PM EDT Thu Sep 3 2020

DEC001-040309-
/O.CAN.KPHI.SV.W.0292.000000T0000Z-200904T0315Z/
Kent DE-
1059 PM EDT Thu Sep 3 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN KENT COUNTY IS
CANCELLED...

The storms which prompted the warning have  moved out of the warned 
area. Therefore, the warning has been cancelled.

LAT...LON 3878 7562 3884 7559 3884 7555 3890 7549
      3892 7541 3896 7539 3895 7537 3896 7536
      3895 7532 3900 7533 3900 7529 3884 7520
      3881 7508 3857 7505
TIME...MOT...LOC 0259Z 288DEG 21KT 3885 7502 3873 7509 3865 7521 

$$

DEC005-040315-
/O.CON.KPHI.SV.W.0292.000000T0000Z-200904T0315Z/
Sussex DE-
1059 PM EDT Thu Sep 3 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1115 PM EDT
FOR CENTRAL SUSSEX COUNTY...

At 1059 PM EDT, severe thunderstorms were located along a line
extending from near Cape Henlopen State Park to Henlopen Acres to 6
miles northeast of Millsboro, moving east at 25 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Georgetown, Milford, Lewes, Milton, Ellendale, Henlopen Acres, Cape
Henlopen State Park, Long Neck, Greenwood and Dewey Beach.

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.

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

&&

LAT...LON 3878 7562 3884 7559 3884 7555 3890 7549
      3892 7541 3896 7539 3895 7537 3896 7536
      3895 7532 3900 7533 3900 7529 3884 7520
      3881 7508 3857 7505
TIME...MOT...LOC 0259Z 288DEG 21KT 3885 7502 3873 7509 3865 7521 

TORNADO...POSSIBLE
HAIL...0.75IN
WIND...60MPH
 
$$

NC

671 
WWUS51 KPHI 040310
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1110 PM EDT Thu Sep 3 2020

DEC005-040320-
/O.EXP.KPHI.SV.W.0292.000000T0000Z-200904T0315Z/
Sussex DE-
1110 PM EDT Thu Sep 3 2020

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL SUSSEX COUNTY WILL
EXPIRE AT 1115 PM EDT...
    
The storms which prompted the warning have weakened below severe
limits, and have exited the warned area. Therefore, the warning will
be allowed to expire.  However gusty winds and heavy rain are still
possible with these thunderstorms.

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 3878 7562 3884 7559 3884 7555 3890 7549
      3892 7541 3896 7539 3895 7537 3896 7536
      3895 7532 3900 7533 3900 7529 3884 7520
      3881 7508 3857 7505
TIME...MOT...LOC 0310Z 288DEG 21KT 3883 7495 3871 7502 3863 7514 

$$

NC

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 3, 10:02 PM EDT	Special Weather Statement	PHI	Kent	28 min
Sep 4, 12:59 AM EDT	Special Weather Statement	PHI	Kent	46 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2020 Every 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.