Alert archive / Delaware / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 140, NWS Philadelphia/Mount Holly

July 6, 2020New Castle County, Delaware; Cecil County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 6, 2020, 6:37 PM EDT for New Castle County, Delaware; Cecil County, Maryland. It was in force for 53 min. 2 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, 6:37 PM EDT (22:37 UTC)
Expired: Jul 6, 2020, 7:30 PM EDT
In force: 53 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties New Castle County, DE, Cecil County, MD

The radar

The Dover AFB radar (KDOX), 72 km from the middle of the area, began a volume at 22:38 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, 6:54 PM EDT	HAIL 0.5	3 Sw Summit Bridge, DE	MPING REPORT.
Jul 6, 7:00 PM EDT	TSTM WND DMG	1 W Odessa, DE	DOWNED TREE LIMBS AND WIRES NEAR BRICK MILL ROAD AND DOVE RUN BOULEVARD IN ODESSA. 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 10.6 hours before the alert went out and 155 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: 1250 J/kg
Mixed-layer CIN: -133 J/kg
Mixed-layer LCL: 1150 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 62 m²/s²
0-3 km storm-relative helicity: 57 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

648 
WUUS51 KPHI 062237
SVRPHI
DEC003-MDC015-062330-
/O.NEW.KPHI.SV.W.0140.200706T2237Z-200706T2330Z/

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

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southwestern New Castle County in northern Delaware...
  Southeastern Cecil County in northeastern Maryland...

* Until 730 PM EDT.

* At 637 PM EDT, a severe thunderstorm was located over Mount
  Pleasant, or near Middletown, moving southeast at 10 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Minor damage to vehicles is possible. Wind damage to 
           roofs, siding, trees, and power lines is possible.

* Locations impacted include...
  Middletown, Warwick, Mount Pleasant, Cayots, Bohemias Mills,
  Townsend, Chesapeake City and Odessa.

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

&&

LAT...LON 3956 7568 3949 7556 3938 7554 3932 7575
      3933 7576 3938 7577 3938 7580 3952 7591
TIME...MOT...LOC 2237Z 317DEG 8KT 3951 7570 

HAIL...1.00IN
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, 3:16 AM EDT	Heat Advisory	PHI	New Castle	12 hr
Jul 6, 12:52 PM EDT	Flash Flood Watch	PHI	New Castle	8 hr
Jul 6, 5:43 PM EDT	Areal Flood Advisory	PHI	New Castle	3 hr
Jul 6, 6:00 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	60 min
Jul 6, 6:13 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	48 min
Jul 6, 7:41 PM EDT	Severe Thunderstorm Warning	PHI	Kent, New Castle, Sussex	64 min
Jul 6, 7:48 PM EDT	Areal Flood Advisory	PHI	Kent, New Castle	117 min
Jul 6, 4:49 PM EDT	Special Weather Statement	PHI	Cecil	56 min
Jul 6, 5:14 PM EDT	Severe Thunderstorm Warning	PHI	Cecil	61 min
Jul 6, 7:03 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Kent, Queen Anne's	42 min
Jul 6, 7:23 PM EDT	Tornado Warning	PHI	Caroline, Kent, Queen Anne's	19 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.