Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 161, NWS Philadelphia/Mount Holly

July 9, 2021Delaware County, Philadelphia County, Pennsylvania; Camden County, Gloucester County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 9, 2021, 7:17 PM EDT for Delaware County, Philadelphia County, Pennsylvania; Camden County, Gloucester County, New Jersey. It was in force for 23 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 9, 2021, 7:17 PM EDT (23:17 UTC)
Expired: Jul 9, 2021, 7:40 PM EDT
In force: 23 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Camden County, NJ, Gloucester County, NJ, Delaware County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 66 km from the middle of the area, began a volume at 23:17 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.

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 11.3 hours before the alert went out and 212 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 712 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 57 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.

931 
WUUS51 KPHI 092317
SVRPHI
NJC007-015-PAC045-101-100000-
/O.NEW.KPHI.SV.W.0161.210709T2317Z-210710T0000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
717 PM EDT Fri Jul 9 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northwestern Camden County in southern New Jersey...
  Northwestern Gloucester County in southern New Jersey...
  Southwestern Philadelphia County in southeastern Pennsylvania...
  Southeastern Delaware County in southeastern Pennsylvania...

* Until 800 PM EDT.

* At 717 PM EDT, a severe thunderstorm was located over Gibbstown, or
  10 miles southwest of Gloucester City, moving east at 25 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...
  Philadelphia, Camden, Gloucester City, Cherry Hill, Deptford,
  Voorhees, West Deptford, Lindenwold, Bellmawr, Woodbury, Berlin,
  Folcroft, Paulsboro, Magnolia, Westville, Woodbury Heights,
  National Park, Swedesboro, Brooklawn and Audubon Park.

This includes the following highways...
 New Jersey Turnpike between exits 2 and 3.
 Interstate 95 in Pennsylvania between mile markers 9 and 21.
 Interstate 76 in Pennsylvania between mile markers 346 and 351.
 Interstate 76 in New Jersey between mile markers 0 and 3.
 Interstate 295 in New Jersey between mile markers 9 and 35.
 Interstate 676 in New Jersey between mile markers 0 and 3.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3974 7538 3980 7540 3994 7522 3996 7502
      3981 7490 3980 7491
TIME...MOT...LOC 2317Z 253DEG 20KT 3980 7529 

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

Staarmann

2 follow-up statements

722 
WWUS51 KPHI 092335
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
735 PM EDT Fri Jul 9 2021

PAC045-092345-
/O.CAN.KPHI.SV.W.0161.000000T0000Z-210710T0000Z/
Delaware PA-
735 PM EDT Fri Jul 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN DELAWARE COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 3975 7527 3982 7526 3990 7518 3996 7502
      3981 7490 3980 7491
TIME...MOT...LOC 2335Z 253DEG 20KT 3983 7516 

$$

NJC007-015-PAC101-100000-
/O.CON.KPHI.SV.W.0161.000000T0000Z-210710T0000Z/
Camden NJ-Gloucester NJ-Philadelphia PA-
735 PM EDT Fri Jul 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR NORTHWESTERN CAMDEN...NORTH CENTRAL GLOUCESTER AND SOUTH CENTRAL
PHILADELPHIA COUNTIES...

At 735 PM EDT, a severe thunderstorm was located over Deptford, or
near Gloucester City, moving east 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...
Philadelphia, Camden, Gloucester City, Cherry Hill, Deptford,
Voorhees, West Deptford, Lindenwold, Bellmawr, Woodbury, Berlin,
Paulsboro, Magnolia, Westville, Woodbury Heights, National Park,
Brooklawn, Audubon Park, Barclay-Kingston and Cherry Hill Mall.

This includes the following highways...
 New Jersey Turnpike near exit 3.
 Interstate 95 in Pennsylvania between mile markers 16 and 18.
 Interstate 76 in Pennsylvania near mile marker 351.
 Interstate 76 in New Jersey between mile markers 0 and 3.
 Interstate 295 in New Jersey between mile markers 18 and 35.
 Interstate 676 in New Jersey between mile markers 0 and 1.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3975 7527 3982 7526 3990 7518 3996 7502
      3981 7490 3980 7491
TIME...MOT...LOC 2335Z 253DEG 20KT 3983 7516 

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

Staarmann

330 
WWUS51 KPHI 092340
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
740 PM EDT Fri Jul 9 2021

NJC007-015-PAC101-092349-
/O.CAN.KPHI.SV.W.0161.000000T0000Z-210710T0000Z/
Camden NJ-Gloucester NJ-Philadelphia PA-
740 PM EDT Fri Jul 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN CAMDEN...NORTH
CENTRAL GLOUCESTER AND SOUTH CENTRAL PHILADELPHIA COUNTIES IS
CANCELLED...
                
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 has been cancelled.  However heavy rain is
still possible with this thunderstorm.

LAT...LON 3975 7527 3982 7526 3990 7518 3996 7502
      3981 7490 3980 7491
TIME...MOT...LOC 2338Z 253DEG 20KT 3984 7513 

$$

Staarmann

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 9, 2:05 AM EDT	Areal Flood Advisory	PHI	Philadelphia	8 hr
Jul 9, 4:44 AM EDT	Areal Flood Advisory	PHI	Bucks, Philadelphia	5 hr
Jul 9, 5:17 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware	43 min
Jul 9, 6:55 PM EDT	Special Weather Statement	PHI	Carbon	35 min
Jul 9, 7:07 PM EDT	Areal Flood Advisory	PHI	Carbon, Lehigh, Monroe, Northampton	3 hr
Jul 9, 7:31 PM EDT	Special Weather Statement	PHI	Northampton	29 min
Jul 9, 7:39 PM EDT	Areal Flood Advisory	PHI	Monroe, Northampton	2 hr
Jul 8, 10:25 PM EDT	Areal Flood Advisory	PHI	Cape May, Cumberland	7 hr
Jul 8, 11:02 PM EDT	Special Marine Warning	PHI		88 min
Jul 8, 11:59 PM EDT	Areal Flood Advisory	PHI	Salem	5 hr
Jul 9, 12:07 AM EDT	Special Marine Warning	PHI		53 min
Jul 9, 12:08 AM EDT	Areal Flood Advisory	PHI	Atlantic, Camden, Gloucester	6 hr
Jul 9, 12:25 AM EDT	Special Marine Warning	PHI		95 min
Jul 9, 1:34 AM EDT	Special Marine Warning	PHI		86 min
Jul 9, 1:49 AM EDT	Special Marine Warning	PHI		26 min
Jul 9, 2:50 AM EDT	Tornado Warning	PHI	Atlantic, Cape May, Cumberland	25 min
Jul 9, 2:53 AM EDT	Special Marine Warning	PHI		68 min
Jul 9, 3:38 AM EDT	Tornado Warning	PHI	Atlantic, Burlington, Ocean	18 min
Jul 9, 3:51 AM EDT	Special Marine Warning	PHI		84 min
Jul 9, 4:08 AM EDT	Gale Warning	PHI		3 hr
Jul 9, 4:41 AM EDT	Tornado Warning	PHI	Monmouth, Ocean	34 min
Jul 9, 4:54 AM EDT	Areal Flood Advisory	PHI	Morris, Somerset	5 hr
Jul 9, 4:58 AM EDT	Special Marine Warning	PHI		39 min
Jul 9, 5:34 PM EDT	Areal Flood Advisory	PHI	Sussex, Warren	2 hr
Jul 9, 6:19 PM EDT	Severe Thunderstorm Warning	PHI	Salem	41 min
Jul 9, 6:24 PM EDT	Special Marine Warning	PHI		66 min
Jul 9, 6:50 PM EDT	Areal Flood Advisory	PHI	Gloucester, Salem	2 hr
Jul 9, 6:57 PM EDT	Severe Thunderstorm Warning	PHI	Cumberland, Gloucester, Salem	63 min
Jul 9, 7:43 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Camden, Cape May, Cumberland, Gloucester, Salem	62 min
Jul 9, 7:46 PM EDT	Areal Flood Advisory	PHI	Atlantic, Camden, Cumberland, Gloucester, Salem	108 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2021 Severe Thunderstorm Warnings in New Jersey, 2021 Every severe thunderstorm warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.