Alert archive / New Jersey / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 100, NWS Philadelphia/Mount Holly

June 21, 20214 counties in Pennsylvania; New Castle County, Delaware; 5 counties in New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 21, 2021, 7:12 PM EDT for 4 counties in Pennsylvania; New Castle County, Delaware; 5 counties in New Jersey. It was in force for 48 min. 11 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: Jun 21, 2021, 7:12 PM EDT (23:12 UTC)
Expired: Jun 21, 2021, 8:00 PM EDT
In force: 48 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties New Castle County, DE, Burlington County, NJ, Camden County, NJ, Cumberland County, NJ, Gloucester County, NJ, Salem County, NJ, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 70 km from the middle of the area, began a volume at 23:13 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
Jun 21, 7:13 PM EDT	TSTM WND DMG	1 N Paoli, PA	DOWNED TREE ON VALLEY ROAD. TIME ESTIMATED FROM RADAR.
Jun 21, 7:13 PM EDT	TSTM WND DMG	2 Nne Willistown Twp, PA	DOWNED TREE ON GOSHEN ROAD. TIME ESTIMATED FROM RADAR.
Jun 21, 7:13 PM EDT	TSTM WND DMG	New Castle, DE	DOWNED WIRES NEAR SECOND STREET. TIME ESTIMATED FROM RADAR.
Jun 21, 7:15 PM EDT	TSTM WND DMG	Glendale, DE	SEVERAL REPORTS OF DOWNED TREE LIMBS AND POWER LINES IN THE AREA. TIME ESTIMATED FROM RADAR.
Jun 21, 7:20 PM EDT	TSTM WND DMG	1 Ne Pennsville, NJ	REPORT OF A TREE DOWN INTO A HOUSE. TIME ESTIMATED FROM RADAR.
Jun 21, 7:27 PM EDT	TSTM WND DMG	2 Ne Pennsville, NJ	DOWNED TREE ON INTERSTATE 295 NORTHBOUND NEAR EXIT 1. SEVERAL REPORTS OF POWER LINES DOWN IN THE AREA AS WELL. TIME ESTIMATED FROM RADAR.
Jun 21, 7:27 PM EDT	MARINE TSTM WIND 52	4 Ssw Elsinboro Twp, NJ
Jun 21, 7:29 PM EDT	TSTM WND DMG	2 Nne Mcdonough, DE	DOWNED POWER LINES NEAR PORT PENN ROAD. TIME ESTIMATED FROM RADAR.
Jun 21, 7:30 PM EDT	TSTM WND DMG	3 Nnw Woodstown, NJ	MEDIUM-SIZE TREE DOWN AT THE INTERSECTION OF AUBURN ROAD AND SHARPTOWN-AUBURN ROAD. TIME ESTIMATED FROM RADAR.
Jun 21, 7:45 PM EDT	TSTM WND DMG	1 Ssw Philadelphia, PA	FEW TREES DOWN IN THE BELLA VISTA AREA OF PHILADELPHIA. TIME ESTIMATED FROM RADAR.
Jun 21, 7:50 PM EDT	TSTM WND GST 70	Gloucester Twp, NJ	MEASURED FROM A PERSONAL WEATHER STATION. TIME ESTIMATED.

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
Jun 21, 4:33 PM EDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 11.2 hours before the alert went out and 199 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: 525 J/kg
Mixed-layer CIN: -38 J/kg
Mixed-layer LCL: 630 m above ground
0-6 km bulk shear: 7 kt
0-1 km storm-relative helicity: 4 m²/s²
0-3 km storm-relative helicity: -14 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

112 
WUUS51 KPHI 212312
SVRPHI
DEC003-NJC005-007-011-015-033-PAC029-045-091-101-220000-
/O.NEW.KPHI.SV.W.0100.210621T2312Z-210622T0000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
712 PM EDT Mon Jun 21 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northern New Castle County in northern Delaware...
  Northern Cumberland County in southern New Jersey...
  Salem County in southern New Jersey...
  Camden County in southern New Jersey...
  Gloucester County in southern New Jersey...
  West central Burlington County in southern New Jersey...
  Southeastern Montgomery County in southeastern Pennsylvania...
  Southeastern Chester County in southeastern Pennsylvania...
  Philadelphia County in southeastern Pennsylvania...
  Delaware County in southeastern Pennsylvania...

* Until 800 PM EDT.

* At 711 PM EDT, a cluster of severe thunderstorms were located over 
  western Chester County near Kennett Square, moving east at 40 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, Wilmington, Vineland, Newark, Millville,
  Bridgeton, Gloucester City, Cherry Hill, Evesham, Mount Laurel,
  Chester, Deptford, Voorhees, West Deptford, Glassboro, Lindenwold,
  Hammonton, Pennsville and Bellmawr.

People at the Burlington County Mega Site, and Gloucester County Mega
Site should seek safe shelter immediately!

This includes the following highways...
 New Jersey Turnpike between exits 1 and 4.
 Pennsylvania Turnpike between mile markers 322 and 325.
 Interstate 95 in Pennsylvania between mile markers 0 and 29.
 Interstate 95 in Delaware between mile markers 2 and 23.
 Interstate 76 in Pennsylvania between mile markers 327 and 351.
 Interstate 76 in New Jersey between mile markers 0 and 3.
 Interstate 295 in New Jersey between mile markers 0 and 38.
 Interstate 676 in Pennsylvania between mile markers 0 and 1.
 Interstate 676 in New Jersey between mile markers 0 and 4.
 Interstate 476 in Pennsylvania between mile markers 0 and 17.
 Atlantic City Expressway between mile markers 30 and 44.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4008 7550 4009 7542 4006 7507 3974 7470
      3972 7472 3973 7473 3952 7499 3950 7496
      3942 7504 3933 7534 3938 7544 3962 7578
TIME...MOT...LOC 2311Z 275DEG 33KT 3972 7567 

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

NC

1 follow-up statement

974 
WWUS51 KPHI 212351
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
751 PM EDT Mon Jun 21 2021

DEC003-NJC005-007-011-015-033-PAC029-045-091-101-220001-
/O.EXP.KPHI.SV.W.0100.000000T0000Z-210622T0000Z/
New Castle DE-Cumberland NJ-Salem NJ-Camden NJ-Gloucester NJ-
Burlington NJ-Montgomery PA-Chester PA-Philadelphia PA-Delaware PA-
751 PM EDT Mon Jun 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN NEW CASTLE...NORTHERN
CUMBERLAND...SALEM...CAMDEN...GLOUCESTER...WEST CENTRAL BURLINGTON...
SOUTHEASTERN MONTGOMERY...SOUTHEASTERN CHESTER...PHILADELPHIA AND
DELAWARE COUNTIES WILL EXPIRE AT 800 PM EDT...
                
The stormd which prompted the warning habr 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 still possible with these thunderstorms.

A Severe Thunderstorm Watch remains in effect until midnight EDT for
northern Delaware...southern New Jersey...and southeastern
Pennsylvania.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Mount Holly NJ.

LAT...LON 4008 7550 4009 7542 4006 7507 3974 7470
      3972 7472 3973 7473 3952 7499 3950 7496
      3942 7504 3933 7534 3938 7544 3962 7578
TIME...MOT...LOC 2351Z 275DEG 33KT 3969 7521 

$$

NC

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 20, 9:27 PM EDT	Special Weather Statement	PHI	Schuylkill	33 min
Jun 20, 9:55 PM EDT	Special Weather Statement	PHI	Lebanon	35 min
Jun 20, 10:04 PM EDT	Areal Flood Advisory	PHI	Berks	86 min
Jun 20, 10:27 PM EDT	Special Weather Statement	PHI	Berks	33 min
Jun 21, 4:35 AM EDT	Heat Advisory	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	15 hr
Jun 21, 6:08 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh	52 min
Jun 21, 6:21 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware	54 min
Jun 21, 7:02 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Carbon, Lehigh, Northampton	43 min
Jun 21, 7:38 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Lehigh, Monroe, Northampton	52 min
Jun 21, 6:47 PM EDT	Severe Thunderstorm Warning	PHI	Kent, New Castle	58 min
Jun 21, 7:43 PM EDT	Severe Thunderstorm Warning	PHI	Kent, New Castle, Sussex	47 min
Jun 21, 7:24 PM EDT	Special Marine Warning	PHI		66 min
Jun 21, 7:55 PM EDT	Special Weather Statement	PHI	Atlantic, Burlington, Camden, Mercer, Ocean	50 min

Nearby

Severe Thunderstorm Warnings in New Jersey, 2021 Severe Thunderstorm Warnings in Pennsylvania, 2021 Severe Thunderstorm Warnings in Delaware, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.