Alert archive / Delaware / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 146, NWS Philadelphia/Mount Holly

July 6, 2020Kent County, Sussex County, Delaware; Caroline County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 6, 2020, 8:53 PM EDT for Kent County, Sussex County, Delaware; Caroline County, Maryland. It was in force for 37 min. 3 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: Jul 6, 2020, 8:53 PM EDT (00:53 UTC)
Expired: Jul 6, 2020, 9:30 PM EDT
In force: 37 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Kent County, DE, Sussex County, DE, Caroline County, MD

The radar

The Dover AFB radar (KDOX), 20 km from the middle of the area, began a volume at 00:53 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
Jul 6, 9:00 PM EDT	TSTM WND DMG	3 E Seaford, DE	DOWNED TREE AND POWER LINES NEAR HOLLEY VALLEY ROAD IN SEAFORD. TIME ESTIMATED FROM RADAR.
Jul 6, 9:03 PM EDT	TSTM WND DMG	3 Se Bridgeville, DE	DOWNED TREE LIMB AND POWER LINES NEAR RITCHIE LANE IN BRIDGEVILLE. TIME ESTIMATED FROM RADAR.
Jul 6, 9:03 PM EDT	TSTM WND DMG	4 Ene Seaford, DE	DOWNED WIRES ON CONCORD POND ROAD. 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.

Issued	Product	Office	Lasted
Jul 6, 1:38 PM EDT	Severe Thunderstorm Watch	SPC	9 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 0.9 hours before the alert went out and 84 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: 1831 J/kg
Mixed-layer CIN: -67 J/kg
Mixed-layer LCL: 1086 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 64 m²/s²
0-3 km storm-relative helicity: 74 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 4.1

Open this sounding in Storm Lab

The text

As transmitted.

416 
WUUS51 KPHI 070053
SVRPHI
DEC001-005-MDC011-070130-
/O.NEW.KPHI.SV.W.0146.200707T0053Z-200707T0130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
853 PM EDT Mon Jul 6 2020

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Sussex County in southern Delaware...
  Southeastern Kent County in central Delaware...
  Southeastern Caroline County in eastern Maryland...

* Until 930 PM EDT.

* At 851 PM EDT, severe thunderstorms were located along a line
  extending from near Viola to near Ellendale to near Sharptown,
  moving southeast at 30 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Georgetown, Milford, Seaford, Millsboro, Laurel, Harrington, Lewes,
  Milton, Bridgeville, Delmar, Dagsboro, Millville, Ellendale, Viola,
  Gumboro, Andrewsville, Sycamore, Big Stone Beach, Long Neck and
  Felton.

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.

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

&&

LAT...LON 3846 7569 3849 7570 3864 7571 3870 7578
      3873 7577 3882 7567 3904 7563 3906 7530
      3858 7507 3845 7526
TIME...MOT...LOC 0051Z 303DEG 25KT 3899 7555 3876 7543 3857 7567 

HAIL...<.75IN
WIND...60MPH
 
$$

Robertson

1 follow-up statement

917 
WWUS51 KPHI 070111
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
911 PM EDT Mon Jul 6 2020

MDC011-070119-
/O.CAN.KPHI.SV.W.0146.000000T0000Z-200707T0130Z/
Caroline MD-
911 PM EDT Mon Jul 6 2020

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

The storms which prompted the warning have weakened and moved out of 
the warned area. Therefore, the warning has been cancelled. However 
gusty winds and heavy rain are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
central and southern Delaware.

LAT...LON 3846 7569 3867 7571 3886 7558 3901 7558
      3905 7530 3858 7506 3845 7526
TIME...MOT...LOC 0109Z 293DEG 22KT 3898 7544 3880 7532 3844 7558 

$$

DEC001-005-070130-
/O.CON.KPHI.SV.W.0146.000000T0000Z-200707T0130Z/
Sussex DE-Kent DE-
911 PM EDT Mon Jul 6 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 930 PM EDT
FOR SUSSEX AND SOUTHEASTERN KENT COUNTIES...

At 909 PM EDT, severe thunderstorms were located along a line
extending from near Milford to Milton to Delmar, moving southeast at
25 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Georgetown, Milford, Seaford, Millsboro, Laurel, Harrington, Lewes,
Milton, Bridgeville, Delmar, Dagsboro, Millville, Ellendale, Gumboro,
Sycamore, Big Stone Beach, Long Neck, Felton, Blades 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.

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

&&

LAT...LON 3846 7569 3867 7571 3886 7558 3901 7558
      3905 7530 3858 7506 3845 7526
TIME...MOT...LOC 0109Z 293DEG 22KT 3898 7544 3880 7532 3844 7558 

HAIL...<.75IN
WIND...60MPH
 
$$

Robertson

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 6, 8:21 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	39 min
Jul 6, 8:41 PM EDT	Areal Flood Advisory	PHI	Kent, Sussex	2 hr
Jul 6, 9:25 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	24 min
Jul 6, 9:49 PM EDT	Special Weather Statement	PHI	Sussex	56 min
Jul 7, 5:21 PM EDT	Areal Flood Advisory	PHI	Caroline, Talbot	55 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2020 Severe Thunderstorm Warnings in Maryland, 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.