Alert archive / Delaware / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 145, NWS Philadelphia/Mount Holly

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

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 6, 2020, 8:21 PM EDT for Kent County, Sussex County, Delaware; Caroline County, Talbot County, Maryland. It was in force for 39 min. 5 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, 8:21 PM EDT (00:21 UTC)
Expired: Jul 6, 2020, 9:00 PM EDT
In force: 39 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, Talbot County, MD

The radar

The Dover AFB radar (KDOX), 35 km from the middle of the area, began a volume at 00:21 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, 8:28 PM EDT	TSTM WND DMG	1 Nnw Trappe, MD	STATE HIGHWAY 565 NORTHBOUND PAST BACKTOWN ROAD IN TRAPPE WAS CLOSED FROM WIND-BLOWN DEBRIS. TIME ESTIMATED FROM RADAR.
Jul 6, 8:46 PM EDT	TSTM WND GST 59	2 Sse Greenwood, DE
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, 0.4 hours before the alert went out and 90 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.

688 
WUUS51 KPHI 070021
SVRPHI
DEC001-005-MDC011-041-070100-
/O.NEW.KPHI.SV.W.0145.200707T0021Z-200707T0100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
821 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 Talbot County in eastern Maryland...
  Southern Caroline County in eastern Maryland...

* Until 900 PM EDT.

* At 819 PM EDT, severe thunderstorms were located along a line
  extending from near Hazlettville to near Andrewsville to near
  Oxford, 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, Laurel, Harrington, Federalsburg,
  Milton, Bridgeville, Trappe, Preston, Ellendale, Bowers,
  Smithville, Rising Sun-Lebanon, Agner, Choptank, Dover Base
  Housing, Windyhill, Rising Sun and Sycamore.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3864 7571 3869 7577 3868 7580 3871 7584
      3868 7593 3857 7602 3859 7606 3860 7606
      3863 7608 3864 7615 3867 7617 3880 7565
      3913 7550 3901 7527 3854 7531 3846 7561
      3846 7569
TIME...MOT...LOC 0019Z 313DEG 27KT 3910 7560 3882 7567 3867 7625 

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, 8:41 PM EDT	Areal Flood Advisory	PHI	Kent, Sussex	2 hr
Jul 6, 8:53 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	37 min
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.