Alert archive / New Jersey / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 166, NWS Philadelphia/Mount Holly

July 12, 20215 counties in New Jersey; Bucks County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 12, 2021, 3:08 PM EDT for 5 counties in New Jersey; Bucks County, Philadelphia County, Pennsylvania. It was in force for 67 min. 9 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: Jul 12, 2021, 3:08 PM EDT (19:08 UTC)
Expired: Jul 12, 2021, 4:15 PM EDT
In force: 67 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Burlington County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Ocean County, NJ, Bucks County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 37 km from the middle of the area, began a volume at 19:08 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 12, 3:10 PM EDT	TSTM WND DMG	Cinnaminson, NJ	WIRES DOWN IN CINNAMINSON. TIME ESTIMATED FROM RADAR AND DISPATCH REPORT.
Jul 12, 3:13 PM EDT	TSTM WND DMG	1 Sw Bordentown Twp, NJ	DOWNED WIRES AND POWER OUTAGES IN THE FIELDSBORO AREA AND NEAR DUNNS MILL ROAD. TIME ESTIMATED FROM RADAR.
Jul 12, 3:15 PM EDT	TSTM WND DMG	Florence, NJ	SCANNER REPORT OF DOWNED WIRES IN FLORENCE. TIME ESTIMATED FROM RADAR AND DISPATCH REPORT.
Jul 12, 3:16 PM EDT	TSTM WND DMG	2 Ne Columbus, NJ	DOWNED WIRES NEAR MILLENNIUM DRIVE. TIME ESTIMATED FROM RADAR.
Jul 12, 3:16 PM EDT	TSTM WND DMG	2 Sse Bordentown Twp, NJ	DOWNED WIRES NEAR OLD YORK ROAD. TIME ESTIMATED FROM RADAR.
Jul 12, 3:19 PM EDT	TSTM WND DMG	Jamesburg, NJ	MULTIPLE REPORTS OF WIRES DOWN AND POWER OUTAGES IN THE JAMESBURG AREA. TIME ESTIMATED FROM RADAR.
Jul 12, 3:23 PM EDT	TSTM WND DMG	Jamesburg, NJ	WIRES DOWN IN JAMESBURG. TIME ESTIMATED FROM RADAR.
Jul 12, 3:32 PM EDT	TSTM WND DMG	Spotswood, NJ	A COUPLE OF REPORTS OF DOWNED WIRES IN THE SPOTSWOOD AREA. TIME ESTIMATED FROM RADAR.
Jul 12, 3:52 PM EDT	TSTM WND DMG	1 Ne Bordentown Twp, NJ	DOWNED WIRES NEAR THORNTOWN LANE. 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

Brookhaven, NY (KOKX), launched 12:00Z, 7.1 hours before the alert went out and 170 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: 857 J/kg
Mixed-layer CIN: -57 J/kg
Mixed-layer LCL: 697 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 85 m²/s²
0-3 km storm-relative helicity: 114 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 2.4

Open this sounding in Storm Lab

The text

As transmitted.

454 
WUUS51 KPHI 121908
SVRPHI
NJC005-021-023-025-029-PAC017-101-122015-
/O.NEW.KPHI.SV.W.0166.210712T1908Z-210712T2015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
308 PM EDT Mon Jul 12 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northwestern Ocean County in southern New Jersey...
  Eastern Mercer County in central New Jersey...
  Northern Burlington County in southern New Jersey...
  Central Monmouth County in central New Jersey...
  Southern Middlesex County in northern New Jersey...
  Southeastern Bucks County in southeastern Pennsylvania...
  Northeastern Philadelphia County in southeastern Pennsylvania...

* Until 415 PM EDT.

* At 308 PM EDT, a severe thunderstorm was located over Cranbury, or 
  13 miles south of New Brunswick, moving northeast at 15 mph. Other 
  strong to potentially severe storms were located from Northeast 
  Philadelphia to Hamilton, and were nearly stationary.

  HAZARD...60 mph wind gusts and penny size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to roofs, siding, trees, and power lines is 
           possible.

* Locations impacted include...
  Philadelphia, Old Bridge, Bensalem, East Brunswick, Manalapan,
  Willingboro, Princeton, Florence, Burlington, Bristol, Matawan,
  Riverside, Palmyra, Jamesburg, Hightstown, Bordentown, Cranbury,
  Beverly, Tullytown and Allentown.

This includes the following highways...
 New Jersey Turnpike between exits 5 and 9.
 Pennsylvania Turnpike between mile markers 352 and 359.
 Interstate 95 in Pennsylvania between mile markers 30 and 40.
 Interstate 195 in New Jersey between mile markers 2 and 18.
 Interstate 295 in New Jersey between mile markers 44 and 58, and
between mile markers 63 and 69.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 4003 7448 3998 7501 3999 7503 4012 7503
      4017 7468 4037 7477 4039 7462 4037 7461
      4039 7459 4043 7422
TIME...MOT...LOC 1908Z 243DEG 14KT 4030 7450 

HAIL...0.75IN
WIND...60MPH
 
$$

CMS

4 follow-up statements

934 
WWUS51 KPHI 121925
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
325 PM EDT Mon Jul 12 2021

NJC005-021-023-025-029-PAC017-101-122015-
/O.CON.KPHI.SV.W.0166.000000T0000Z-210712T2015Z/
Ocean NJ-Mercer NJ-Burlington NJ-Monmouth NJ-Middlesex NJ-Bucks PA-
Philadelphia PA-
325 PM EDT Mon Jul 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM EDT
FOR NORTHWESTERN OCEAN...SOUTHEASTERN MERCER...NORTHERN BURLINGTON...
CENTRAL MONMOUTH...SOUTHERN MIDDLESEX...SOUTHEASTERN BUCKS AND
NORTHEASTERN PHILADELPHIA COUNTIES...

At 325 PM EDT, a severe thunderstorm was located over Whittingham, 
or 10 miles south of New Brunswick, moving northeast at 15 mph. 
Other strong to potentially severe storms extended from Northeast 
Philadelphia to Cream Ridge, and were nearly stationary.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Philadelphia, Old Bridge, Bensalem, East Brunswick, Manalapan,
Willingboro, Florence, Burlington, Bristol, Matawan, Riverside,
Palmyra, Jamesburg, Hightstown, Bordentown, Cranbury, Beverly,
Tullytown, Allentown and Roosevelt.

This includes the following highways...
 New Jersey Turnpike between exits 5 and 9.
 Pennsylvania Turnpike between mile markers 352 and 359.
 Interstate 95 in Pennsylvania between mile markers 30 and 40.
 Interstate 195 in New Jersey between mile markers 2 and 18.
 Interstate 295 in New Jersey between mile markers 44 and 58, and
between mile markers 63 and 67.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 4003 7448 3998 7501 3999 7503 4012 7503
      4017 7468 4026 7472 4039 7459 4043 7422
TIME...MOT...LOC 1925Z 243DEG 14KT 4033 7442 

HAIL...0.75IN
WIND...60MPH
 
$$

CMS

235 
WWUS51 KPHI 121943
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
343 PM EDT Mon Jul 12 2021

NJC005-021-023-025-029-PAC017-101-122015-
/O.CON.KPHI.SV.W.0166.000000T0000Z-210712T2015Z/
Ocean NJ-Mercer NJ-Burlington NJ-Monmouth NJ-Middlesex NJ-Bucks PA-
Philadelphia PA-
343 PM EDT Mon Jul 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM EDT
FOR NORTHWESTERN OCEAN...SOUTHEASTERN MERCER...NORTHERN BURLINGTON...
CENTRAL MONMOUTH...SOUTHERN MIDDLESEX...SOUTHEASTERN BUCKS AND
NORTHEASTERN PHILADELPHIA COUNTIES...

At 343 PM EDT, a severe thunderstorm was located over Old Bridge, or 
7 miles southeast of New Brunswick, moving northeast at 20 mph. 
Other strong to potentially severe storms were located from 
Northeast Philadelphia to Cream Ridge, and were nearly stationary.

HAZARD...60 mph wind gusts and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Philadelphia, Old Bridge, Bensalem, East Brunswick, Manalapan,
Willingboro, Florence, Burlington, Bristol, Matawan, Riverside,
Palmyra, Jamesburg, Hightstown, Bordentown, Cranbury, Beverly,
Tullytown, Allentown and Roosevelt.

This includes the following highways...
 New Jersey Turnpike between exits 5 and 9.
 Pennsylvania Turnpike between mile markers 352 and 359.
 Interstate 95 in Pennsylvania between mile markers 30 and 40.
 Interstate 195 in New Jersey between mile markers 2 and 18.
 Interstate 295 in New Jersey between mile markers 44 and 58, and
between mile markers 63 and 64.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 4003 7448 3998 7501 3999 7503 4012 7503
      4017 7468 4023 7471 4040 7446 4043 7422
TIME...MOT...LOC 1943Z 227DEG 16KT 4040 7434 

HAIL...0.88IN
WIND...60MPH
 
$$

CMS

991 
WWUS51 KPHI 122000
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
400 PM EDT Mon Jul 12 2021

NJC023-122010-
/O.CAN.KPHI.SV.W.0166.000000T0000Z-210712T2015Z/
Middlesex NJ-
400 PM EDT Mon Jul 12 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN MIDDLESEX COUNTY IS
CANCELLED...

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

A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
southern and central New Jersey...and southeastern Pennsylvania.

LAT...LON 4003 7448 3998 7501 3999 7503 4012 7503
      4017 7468 4018 7438
TIME...MOT...LOC 2000Z 241DEG 7KT 4008 7494 4012 7447 

$$

NJC005-021-025-029-PAC017-101-122015-
/O.CON.KPHI.SV.W.0166.000000T0000Z-210712T2015Z/
Ocean NJ-Mercer NJ-Burlington NJ-Monmouth NJ-Bucks PA-
Philadelphia PA-
400 PM EDT Mon Jul 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM EDT
FOR NORTHWESTERN OCEAN...SOUTH CENTRAL MERCER...NORTHERN
BURLINGTON...SOUTHWESTERN MONMOUTH...SOUTHEASTERN BUCKS AND
NORTHEASTERN PHILADELPHIA COUNTIES...

At 400 PM EDT, severe thunderstorms were located along a line
extending from Beverly to near Six Flags Theme Park, moving northeast
at 10 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Philadelphia, Bensalem, Willingboro, Florence, Burlington, Bristol,
Riverside, Palmyra, Bordentown, Beverly, Tullytown, Allentown,
Wrightstown, Florence-Roebling, Six Flags Theme Park, Northeast
Philadelphia, Jacksonville, Georgetown, Crosswicks and Andalusia.

This includes the following highways...
 New Jersey Turnpike between exits 5 and 7A.
 Pennsylvania Turnpike between mile markers 352 and 359.
 Interstate 95 in Pennsylvania between mile markers 30 and 40.
 Interstate 195 in New Jersey between mile markers 13 and 18.
 Interstate 295 in New Jersey between mile markers 44 and 58.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Frequent cloud to ground lightning is occurring with these storms.
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 these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4003 7448 3998 7501 3999 7503 4012 7503
      4017 7468 4018 7438
TIME...MOT...LOC 2000Z 241DEG 7KT 4008 7494 4012 7447 

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

CMS

184 
WWUS51 KPHI 122007
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
407 PM EDT Mon Jul 12 2021

NJC005-021-025-029-PAC017-101-122017-
/O.EXP.KPHI.SV.W.0166.000000T0000Z-210712T2015Z/
Ocean NJ-Mercer NJ-Burlington NJ-Monmouth NJ-Bucks PA-
Philadelphia PA-
407 PM EDT Mon Jul 12 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN OCEAN...SOUTH
CENTRAL MERCER...NORTHERN BURLINGTON...SOUTHWESTERN MONMOUTH...
SOUTHEASTERN BUCKS AND NORTHEASTERN PHILADELPHIA COUNTIES WILL EXPIRE
AT 415 PM EDT...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However, gusty 
winds and heavy rain are still possible with these thunderstorms.

A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
southern and central New Jersey...and southeastern Pennsylvania.

LAT...LON 4003 7448 3998 7501 3999 7503 4012 7503
      4017 7468 4018 7438
TIME...MOT...LOC 2007Z 243DEG 14KT 4009 7492 4013 7445 

$$

CMS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 12, 1:59 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden	3 hr
Jul 12, 2:12 PM EDT	Flash Flood Warning Emergency	PHI	Burlington	7 hr
Jul 12, 2:20 PM EDT	Areal Flood Advisory	PHI	Mercer, Middlesex, Monmouth	3 hr
Jul 12, 2:37 PM EDT	Flash Flood Warning	PHI	Mercer, Middlesex, Monmouth	93 min
Jul 12, 3:31 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex, Monmouth	41 min
Jul 12, 4:26 PM EDT	Special Marine Warning	PHI		2 hr
Jul 12, 4:33 PM EDT	Severe Thunderstorm Warning	PHI	Monmouth, Ocean	42 min
Jul 12, 4:52 PM EDT	Areal Flood Advisory	PHI	Monmouth, Ocean	98 min
Jul 12, 5:08 PM EDT	Areal Flood Advisory	PHI	Sussex	5 hr
Jul 12, 5:08 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Mercer	67 min
Jul 12, 5:26 PM EDT	Areal Flood Advisory	PHI	Camden	2 hr
Jul 12, 5:36 PM EDT	Special Weather Statement	PHI	Sussex	24 min
Jul 12, 5:41 PM EDT	Areal Flood Advisory	PHI	Burlington	83 min
Jul 12, 5:57 PM EDT	Severe Thunderstorm Warning	PHI	Morris, Sussex	63 min
Jul 12, 6:01 PM EDT	Flash Flood Warning	PHI	Camden	102 min
Jul 12, 6:08 PM EDT	Areal Flood Advisory	PHI	Morris	98 min
Jul 12, 6:43 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester	93 min
Jul 12, 6:52 PM EDT	Severe Thunderstorm Warning	PHI	Morris, Sussex	34 min
Jul 12, 7:00 PM EDT	Areal Flood Advisory	PHI	Gloucester, Salem	112 min
Jul 12, 7:06 PM EDT	Severe Thunderstorm Warning	PHI	Salem	69 min
Jul 12, 7:11 PM EDT	Flash Flood Warning	PHI	Morris, Sussex	35 min
Jul 12, 7:33 PM EDT	Special Marine Warning	PHI		58 min
Jul 11, 10:21 PM EDT	Severe Thunderstorm Warning	PHI	Berks	24 min
Jul 11, 10:22 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Carbon, Lehigh, Monroe, Northampton	38 min
Jul 12, 2:28 PM EDT	Areal Flood Advisory	PHI	Chester	3 hr
Jul 12, 4:16 PM EDT	Areal Flood Advisory	PHI	Bucks, Montgomery, Philadelphia	114 min
Jul 12, 5:41 PM EDT	Severe Thunderstorm Warning	PHI	Chester	34 min
Jul 12, 6:18 PM EDT	Flash Flood Warning	PHI	Delaware	84 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.