Alert archive / New Jersey / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 310, NWS Philadelphia/Mount Holly

September 23, 20214 counties in New Jersey; 4 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Sep 23, 2021, 1:13 PM EDT for 4 counties in New Jersey; 4 counties in Pennsylvania. It was in force for 47 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: Sep 23, 2021, 1:13 PM EDT (17:13 UTC)
Expired: Sep 23, 2021, 2:00 PM EDT
In force: 47 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Salem County, NJ, Bucks County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 63 km from the middle of the area, began a volume at 17:13 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.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 5.2 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: 103 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 687 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 249 m²/s²
0-3 km storm-relative helicity: 201 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.1

Open this sounding in Storm Lab

The text

As transmitted.

789 
WUUS51 KPHI 231713
SVRPHI
NJC005-007-015-033-PAC017-045-091-101-231800-
/O.NEW.KPHI.SV.W.0310.210923T1713Z-210923T1800Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
113 PM EDT Thu Sep 23 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  East central Salem County in southern New Jersey...
  Northwestern Camden County in southern New Jersey...
  Northwestern Gloucester County in southern New Jersey...
  Northwestern Burlington County in southern New Jersey...
  Southeastern Montgomery County in southeastern Pennsylvania...
  South central Bucks County in southeastern Pennsylvania...
  Philadelphia County in southeastern Pennsylvania...
  Eastern Delaware County in southeastern Pennsylvania...

* Until 200 PM EDT.

* At 113 PM EDT, severe thunderstorms were located along a line
  extending from Roxborough to Paulsboro to near Glassboro, moving
  northeast at 30 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, Bensalem,
  Evesham, Mount Laurel, Norristown, Deptford, Voorhees, West
  Deptford, Glassboro, Lindenwold, Lansdale, East Norriton, Bellmawr,
  Yeadon, Woodbury, Pitman and Doylestown.

This includes the following highways...
 New Jersey Turnpike between exits 2 and 4.
 Pennsylvania Turnpike between mile markers 331 and 353.
 Northeast Extension between mile markers 21 and 24.
 Interstate 95 in Pennsylvania between mile markers 8 and 36.
 Interstate 76 in Pennsylvania between mile markers 331 and 351.
 Interstate 76 in New Jersey between mile markers 0 and 3.
 Interstate 295 in New Jersey between mile markers 14 and 40.
 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 7 and 9, and
between mile markers 14 and 19.
 Atlantic City Expressway between mile markers 42 and 44.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4036 7506 4015 7494 3986 7490 3955 7521
      3974 7532 4006 7535 4038 7522
TIME...MOT...LOC 1713Z 212DEG 27KT 3999 7523 3983 7523 3966 7515 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Staarmann

2 follow-up statements

401 
WWUS51 KPHI 231729
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
129 PM EDT Thu Sep 23 2021

PAC045-231739-
/O.CAN.KPHI.SV.W.0310.000000T0000Z-210923T1800Z/
Delaware PA-
129 PM EDT Thu Sep 23 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN DELAWARE COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

LAT...LON 3957 7519 3986 7525 3987 7521 3988 7526
      3990 7526 3994 7524 3997 7525 3997 7528
      4013 7532 4038 7522 4036 7506 4015 7494
      3986 7490
TIME...MOT...LOC 1729Z 211DEG 27KT 4017 7518 3993 7515 3974 7510 

$$

NJC005-007-015-033-PAC017-091-101-231800-
/O.CON.KPHI.SV.W.0310.000000T0000Z-210923T1800Z/
Salem NJ-Camden NJ-Gloucester NJ-Burlington NJ-Montgomery PA-
Bucks PA-Philadelphia PA-
129 PM EDT Thu Sep 23 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 200 PM EDT
FOR EAST CENTRAL SALEM...NORTHWESTERN CAMDEN...NORTH CENTRAL
GLOUCESTER...NORTHWESTERN BURLINGTON...SOUTHEASTERN MONTGOMERY...
SOUTH CENTRAL BUCKS AND PHILADELPHIA COUNTIES...

At 129 PM EDT, severe thunderstorms were located along a line
extending from near Ambler to near Ben Franklin Bridge to Pitman,
moving northeast at 30 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, Bensalem,
Evesham, Mount Laurel, Deptford, Voorhees, West Deptford, Glassboro,
Lindenwold, Lansdale, East Norriton, Bellmawr, Yeadon, Woodbury,
Pitman, Doylestown and Clayton.

This includes the following highways...
 New Jersey Turnpike between exits 3 and 4.
 Pennsylvania Turnpike between mile markers 332 and 353.
 Northeast Extension between mile markers 21 and 24.
 Interstate 95 in Pennsylvania between mile markers 13 and 36.
 Interstate 76 in Pennsylvania between mile markers 333 and 351.
 Interstate 76 in New Jersey between mile markers 0 and 3.
 Interstate 295 in New Jersey between mile markers 19 and 40.
 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 18 and 19.
 Atlantic City Expressway between mile markers 42 and 44.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3957 7519 3986 7525 3987 7521 3988 7526
      3990 7526 3994 7524 3997 7525 3997 7528
      4013 7532 4038 7522 4036 7506 4015 7494
      3986 7490
TIME...MOT...LOC 1729Z 211DEG 27KT 4017 7518 3993 7515 3974 7510 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Staarmann

535 
WWUS51 KPHI 231743
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
143 PM EDT Thu Sep 23 2021

NJC033-231753-
/O.CAN.KPHI.SV.W.0310.000000T0000Z-210923T1800Z/
Salem NJ-
143 PM EDT Thu Sep 23 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL SALEM COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

LAT...LON 3967 7509 3970 7513 3989 7519 3999 7521
      4007 7517 4025 7527 4038 7522 4036 7506
      4015 7494 3986 7490
TIME...MOT...LOC 1743Z 211DEG 27KT 4030 7514 4002 7508 3980 7506 

$$

NJC005-007-015-PAC017-091-101-231800-
/O.CON.KPHI.SV.W.0310.000000T0000Z-210923T1800Z/
Camden NJ-Gloucester NJ-Burlington NJ-Montgomery PA-Bucks PA-
Philadelphia PA-
143 PM EDT Thu Sep 23 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 200 PM EDT
FOR NORTHWESTERN CAMDEN...NORTH CENTRAL GLOUCESTER...NORTHWESTERN
BURLINGTON...EAST CENTRAL MONTGOMERY...SOUTH CENTRAL BUCKS AND
PHILADELPHIA COUNTIES...

At 143 PM EDT, severe thunderstorms were located along a line
extending from Doylestown to Wissinoming to near Turnersville, moving
northeast at 30 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, Bensalem,
Evesham, Mount Laurel, Deptford, Voorhees, Glassboro, Lindenwold,
Lansdale, Bellmawr, Woodbury, Pitman, Doylestown, Clayton, Riverside,
Berlin and Palmyra.

This includes the following highways...
 New Jersey Turnpike between exits 3 and 4.
 Pennsylvania Turnpike between mile markers 338 and 353.
 Interstate 95 in Pennsylvania between mile markers 15 and 36.
 Interstate 76 in Pennsylvania between mile markers 340 and 345, and
between mile markers 347 and 351.
 Interstate 76 in New Jersey between mile markers 0 and 3.
 Interstate 295 in New Jersey between mile markers 23 and 40.
 Interstate 676 in Pennsylvania between mile markers 0 and 1.
 Interstate 676 in New Jersey between mile markers 0 and 4.
 Atlantic City Expressway between mile markers 42 and 44.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3967 7509 3970 7513 3989 7519 3999 7521
      4007 7517 4025 7527 4038 7522 4036 7506
      4015 7494 3986 7490
TIME...MOT...LOC 1743Z 211DEG 27KT 4030 7514 4002 7508 3980 7506 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Staarmann

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 22, 8:43 PM EDT	Gale Warning	PHI		18 hr
Sep 23, 9:12 AM EDT	Coastal Flood Advisory	PHI	Burlington, Camden, Gloucester	10 hr
Sep 23, 11:33 AM EDT	Areal Flood Advisory	PHI	Cumberland, Gloucester, Salem	3 hr
Sep 23, 11:57 AM EDT	Flash Flood Warning	PHI	Gloucester, Salem	3 hr
Sep 23, 12:12 PM EDT	Severe Thunderstorm Warning	PHI	Gloucester, Salem	48 min
Sep 23, 12:54 PM EDT	Special Weather Statement	PHI	Gloucester	51 min
Sep 23, 12:56 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Hunterdon, Mercer, Warren	3 hr
Sep 23, 1:42 PM EDT	Flash Flood Warning	PHI	Burlington, Camden, Gloucester	4 hr
Sep 23, 1:58 PM EDT	Special Weather Statement	PHI	Camden, Hunterdon	32 min
Sep 23, 2:37 PM EDT	Areal Flood Advisory	PHI	Burlington, Hunterdon, Mercer, Middlesex, Monmouth, Morris and 3 more	3 hr
Sep 23, 2:47 PM EDT	Special Weather Statement	PHI	Hunterdon, Mercer	28 min
Sep 23, 2:52 PM EDT	Special Weather Statement	PHI	Camden	23 min
Sep 23, 3:13 PM EDT	Special Weather Statement	PHI	Mercer, Somerset	32 min
Sep 23, 3:16 PM EDT	Special Weather Statement	PHI	Burlington	29 min
Sep 23, 3:23 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset	52 min
Sep 23, 3:26 PM EDT	Flash Flood Warning	PHI	Burlington, Hunterdon, Mercer, Middlesex, Morris, Somerset	2 hr
Sep 23, 3:50 PM EDT	Special Weather Statement	PHI	Burlington	25 min
Sep 23, 4:21 PM EDT	Areal Flood Advisory	PHI	Middlesex, Monmouth, Morris, Ocean, Somerset, Sussex	15 min
Sep 23, 4:36 PM EDT	Flash Flood Warning	PHI	Middlesex, Monmouth, Morris, Somerset, Sussex	3 hr
Sep 23, 5:00 PM EDT	Special Weather Statement	PHI	Monmouth	30 min
Sep 23, 10:52 AM EDT	Areal Flood Advisory	PHI	Chester	3 hr
Sep 23, 11:40 AM EDT	Areal Flood Advisory	PHI	Berks, Bucks, Carbon, Lehigh, Montgomery, Northampton	3 hr
Sep 23, 12:28 PM EDT	Flash Flood Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	4 hr
Sep 23, 12:57 PM EDT	Special Weather Statement	PHI	Bucks	33 min
Sep 23, 1:48 PM EDT	River Flood Warning	PHI	Chester	5 hr
Sep 23, 4:26 PM EDT	Areal Flood Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	80 min
Sep 23, 7:18 PM EDT	Areal Flood Warning	PHI	Berks, Montgomery	36 min

Nearby

Severe Thunderstorm Warnings in New Jersey, 2021 Severe Thunderstorm Warnings in Pennsylvania, 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.