Alert archive / Delaware / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 95, NWS Philadelphia/Mount Holly

July 1, 2020Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 1, 2020, 12:36 PM EDT for Sussex County, Delaware. It was in force for 54 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: Jul 1, 2020, 12:36 PM EDT (16:36 UTC)
Expired: Jul 1, 2020, 1:30 PM EDT
In force: 54 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Sussex County, DE

The radar

The Dover AFB radar (KDOX), 9 km from the middle of the area, began a volume at 16:37 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 1, 12:40 PM EDT	HAIL 0.25	Milford, DE	TIME ESTIMATED FROM RADAR.

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 12:00Z, 4.6 hours before the alert went out and 104 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: 706 J/kg
Mixed-layer CIN: -57 J/kg
Mixed-layer LCL: 1227 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 29 m²/s²
0-3 km storm-relative helicity: 42 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.4

Open this sounding in Storm Lab

The text

As transmitted.

598 
WUUS51 KPHI 011636
SVRPHI
DEC005-011730-
/O.NEW.KPHI.SV.W.0095.200701T1636Z-200701T1730Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
1236 PM EDT Wed Jul 1 2020

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northeastern Sussex County in southern Delaware...

* Until 130 PM EDT.

* At 1236 PM EDT, a severe thunderstorm was located near Ellendale,
  or 11 miles north of Georgetown, moving east at 20 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...
  Milford, Lewes, Milton, Ellendale, Henlopen Acres and Cape Henlopen
  State Park.

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.

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 3882 7552 3890 7549 3891 7547 3892 7541
      3895 7539 3894 7526 3884 7508 3870 7502
TIME...MOT...LOC 1636Z 282DEG 15KT 3886 7535 

HAIL...1.00IN
WIND...60MPH
 
$$

Gorse

2 follow-up statements

794 
WWUS51 KPHI 011657
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1257 PM EDT Wed Jul 1 2020

DEC005-011730-
/O.CON.KPHI.SV.W.0095.000000T0000Z-200701T1730Z/
Sussex DE-
1257 PM EDT Wed Jul 1 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 130 PM EDT
FOR NORTHEASTERN SUSSEX COUNTY...

At 1256 PM EDT, a severe thunderstorm was located near Milton, or 12 
miles northeast of Georgetown, moving east at 15 mph. Radar data 
shows a more focused area of potentially damaging winds near the 
Slaughter Beach area.

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...
Milford, Lewes, Milton, Ellendale, Henlopen Acres and Cape Henlopen
State Park.

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.

Frequent cloud to ground lightning is occurring with this storm. 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 3882 7552 3890 7549 3891 7547 3892 7541
      3895 7539 3894 7526 3884 7508 3870 7502
TIME...MOT...LOC 1656Z 283DEG 14KT 3883 7526 

HAIL...1.00IN
WIND...60MPH
 
$$

Gorse

915 
WWUS51 KPHI 011725
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
125 PM EDT Wed Jul 1 2020

DEC005-011735-
/O.EXP.KPHI.SV.W.0095.000000T0000Z-200701T1730Z/
Sussex DE-
125 PM EDT Wed Jul 1 2020

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN SUSSEX COUNTY
WILL EXPIRE AT 130 PM EDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty 
winds are possible and very heavy rain will occur with this 
thunderstorm.

LAT...LON 3882 7552 3890 7549 3891 7547 3892 7541
      3895 7539 3894 7526 3884 7508 3870 7502
TIME...MOT...LOC 1725Z 282DEG 15KT 3881 7512 

$$

Gorse

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 1, 12:15 PM EDT	Special Weather Statement	PHI	Sussex	45 min
Jul 1, 1:11 PM EDT	Areal Flood Warning	PHI	Kent, Sussex	3 hr
Jul 1, 4:57 PM EDT	Special Weather Statement	PHI	New Castle	48 min
Jul 1, 5:27 PM EDT	Areal Flood Advisory	PHI	New Castle	55 min
Jul 1, 5:37 PM EDT	Special Weather Statement	PHI	Kent	38 min
Jul 1, 6:03 PM EDT	Special Weather Statement	PHI	Kent	42 min
Jul 1, 7:04 PM EDT	Special Weather Statement	PHI	Kent	41 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.