Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 74, NWS Philadelphia/Mount Holly

June 23, 2020Chester County, Delaware County, Pennsylvania; New Castle County, Delaware; Gloucester County, Salem County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 23, 2020, 6:12 PM EDT for Chester County, Delaware County, Pennsylvania; New Castle County, Delaware; Gloucester County, Salem County, New Jersey. It was in force for 48 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
Jun 23, 2020, 6:12 PM EDT (22:12 UTC)
Expired
Jun 23, 2020, 7:00 PM EDT
In force
48 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties New Castle County, DE, Gloucester County, NJ, Salem County, NJ, Chester County, PA, Delaware County, PA

The radar

The Philadelphia radar (KDIX), 105 km from the middle of the area, began a volume at 22:14 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

TimeReportWhereRemark
Jun 23, 6:16 PM EDTHAIL 0.71 Se Brookside, DEPEA TO DIME SIZE HAIL.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 10.2 hours before the alert went out and 178 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-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 2020-06-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 9 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2020-06-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 41 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
9 J/kg
Mixed-layer CIN
-145 J/kg
Mixed-layer LCL
1155 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
41 m²/s²
0-3 km storm-relative helicity
100 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

976 
WUUS51 KPHI 232212
SVRPHI
DEC003-NJC015-033-PAC029-045-232300-
/O.NEW.KPHI.SV.W.0074.200623T2212Z-200623T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
612 PM EDT Tue Jun 23 2020

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northern New Castle County in northern Delaware...
  Northwestern Salem County in southern New Jersey...
  Northwestern Gloucester County in southern New Jersey...
  Southeastern Chester County in southeastern Pennsylvania...
  Southwestern Delaware County in southeastern Pennsylvania...

* Until 700 PM EDT.

* At 611 PM EDT, a severe thunderstorm was located over Bear, or near
  Newark, moving northeast 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...
  Wilmington, Newark, Elkton, Chester, Pennsville, Westtown, Carneys
  Point, Elsmere, New Castle, Penns Grove, Newport, Arden, Stanton,
  Cheyney, North Star, Glasgow, Bear, Talleyville, Wilmington Manor
  and Elam.

This includes the following highways...
 Interstate 95 in Pennsylvania between mile markers 0 and 4.
 Interstate 95 in Delaware between mile markers 0 and 23.
 Interstate 295 in New Jersey mile marker 0 and near mile marker 14.

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.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3998 7557 3981 7530 3955 7571 3960 7579
      3969 7579
TIME...MOT...LOC 2211Z 220DEG 19KT 3965 7571 

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

Staarmann
2 follow-up statements
534 
WWUS51 KPHI 232236
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
636 PM EDT Tue Jun 23 2020

DEC003-NJC015-033-PAC029-045-232300-
/O.CON.KPHI.SV.W.0074.000000T0000Z-200623T2300Z/
New Castle DE-Salem NJ-Gloucester NJ-Chester PA-Delaware PA-
636 PM EDT Tue Jun 23 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR NORTHERN NEW CASTLE...NORTHWESTERN SALEM...NORTHWESTERN
GLOUCESTER...SOUTHEASTERN CHESTER AND SOUTHWESTERN DELAWARE
COUNTIES...

At 636 PM EDT, a severe thunderstorm was located over Stanton, or
near Newark, moving northeast at 15 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...
Wilmington, Newark, Chester, Westtown, Carneys Point, Elsmere, New
Castle, Penns Grove, Newport, Arden, Stanton, Cheyney, Talleyville,
Wilmington Manor, Elam, Pike Creek, Chelsea, Ashland, Greenville and
Chester Township.

This includes the following highways...
 Interstate 95 in Pennsylvania between mile markers 0 and 4.
 Interstate 95 in Delaware between mile markers 3 and 23.

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.

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.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3998 7557 3981 7530 3962 7565 3964 7573
      3969 7576
TIME...MOT...LOC 2236Z 222DEG 13KT 3968 7567 

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

Staarmann
093 
WWUS51 KPHI 232253
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
653 PM EDT Tue Jun 23 2020

DEC003-NJC015-033-PAC029-045-232303-
/O.EXP.KPHI.SV.W.0074.000000T0000Z-200623T2300Z/
New Castle DE-Salem NJ-Gloucester NJ-Chester PA-Delaware PA-
653 PM EDT Tue Jun 23 2020

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN NEW CASTLE...
NORTHWESTERN SALEM...NORTHWESTERN GLOUCESTER...SOUTHEASTERN CHESTER
AND SOUTHWESTERN DELAWARE COUNTIES WILL EXPIRE AT 700 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 small 
hail, gusty winds, and heavy rain are still possible with this 
thunderstorm.

LAT...LON 3998 7557 3981 7530 3962 7565 3964 7573
      3969 7576
TIME...MOT...LOC 2253Z 220DEG 19KT 3974 7561 

$$

Staarmann

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 22, 9:18 PM EDTAreal Flood AdvisoryPHIBucks3 hr
Jun 23, 7:09 PM EDTSpecial Weather StatementPHIDelaware36 min
Jun 22, 8:48 PM EDTSpecial Weather StatementPHIMercer42 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2020Severe Thunderstorm Warnings in New Jersey, 2020Severe Thunderstorm Warnings in Delaware, 2020Every 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.