Alert archive / New Jersey / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 199, NWS Philadelphia/Mount Holly

July 17, 20215 counties in New Jersey; 4 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 17, 2021, 9:48 PM EDT for 5 counties in New Jersey; 4 counties in Pennsylvania. It was in force for 42 min. 10 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 17, 2021, 9:48 PM EDT (01:48 UTC)
Expired: Jul 17, 2021, 10:30 PM EDT
In force: 42 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

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

The radar

The Philadelphia radar (KDIX), 53 km from the middle of the area, began a volume at 01:50 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 17, 10:02 PM EDT	TSTM WND DMG	Cherry Hill Twp, NJ	SOME TREES BLOWN DOWN IN A CHERRY HILL NEIGHBORHOOD.
Jul 17, 10:05 PM EDT	TSTM WND DMG	Tacony, PA	REPORT FROM MPING: TREES UPROOTED OR SNAPPED; TIME ESTIMATED FROM RADAR.
Jul 17, 10:10 PM EDT	TSTM WND DMG	Delran, NJ	SEVERAL LARGE LIMBS BLOWN DOWN. TIME ESTIMATED FROM RADAR.
Jul 17, 10:14 PM EDT	TSTM WND DMG	Edgewater Park, NJ	NUMEROUS LIMBS DOWN AND POWER OUTAGE IN EDGEWATER PARK. TIME ESTIMATED FROM RADAR. REPORT RELAYED FROM NWS EMPLOYEE.
Jul 17, 10:20 PM EDT	TSTM WND DMG	3 N Mount Laurel, NJ	REPORT FROM MPING: TREES UPROOTED OR SNAPPED; TIME ESTIMATED FROM RADAR.
Jul 17, 10:20 PM EDT	TSTM WND DMG	Burlington, NJ	SEVERAL LARGE TREE LIMBS BLOWN DOWN IN BURLINGTON.
Jul 17, 10:25 PM EDT	TORNADO	2 Nw Jobstown, NJ	NWS STORM SURVEY CONFIRMED A TORNADO BEGAN AT 10:25 PM EDT JUST EAST OF THE ROUTE 206 AND COLUMBUS-JOBSTOWN ROAD INTERSECTION. A NARROW, DISCONTINUOUS, PATH OF TREE DAMAGE CONTINUED FOR 7.9 MILES, ENDING NEAR JACOBSTOWN, NJ. THE TORNADO DISSIPATED AROUND 10:36
Jul 17, 10:26 PM EDT	TSTM WND DMG	2 Nw Jobstown, NJ	SEVERAL TREES UPROOTED AND ROADS BLOCKED IN A NEIGHBORHOOD IN SOUTH COLUMBUS. TIME ESTIMATED FROM RADAR.
Jul 17, 10:27 PM EDT	TSTM WND DMG	Evesham Twp, NJ	SEVERAL TREES WERE DOWNED IN EVESHAM TWP. TIME ESTIMATED FROM RADAR.
Jul 17, 10:32 PM EDT	TSTM WND DMG	3 Ssw Chesterfield, NJ	LARGE TREE SNAPPED AND SEVERAL LARGE LIMBS DOWN. TIME ESTIMATED FROM RADAR.

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
Jul 17, 1:13 PM EDT	Severe Thunderstorm Watch	SPC	10 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 1.8 hours before the alert went out and 213 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: 1431 J/kg
Mixed-layer CIN: -48 J/kg
Mixed-layer LCL: 988 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 26 m²/s²
0-3 km storm-relative helicity: 54 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.6

Open this sounding in Storm Lab

The text

As transmitted.

444 
WUUS51 KPHI 180148
SVRPHI
NJC005-007-015-021-033-PAC017-045-091-101-180230-
/O.NEW.KPHI.SV.W.0199.210718T0148Z-210718T0230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
948 PM EDT Sat Jul 17 2021

The National Weather Service in Mount Holly NJ has issued a

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

* Until 1030 PM EDT.

* At 947 PM EDT, severe thunderstorms were located along a line
  extending from Roxborough to Philadelphia International Airport to
  near Carneys Point, moving east at 35 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, Trenton, Camden, Gloucester City, Cherry Hill,
  Bensalem, Evesham, Mount Laurel, Ewing, Willingboro, Deptford,
  Voorhees, Medford, West Deptford, Glassboro, Lindenwold,
  Pennsville, Lumberton, Florence and Bellmawr.

This includes the following highways...
 New Jersey Turnpike between exits 1 and 7A.
 Pennsylvania Turnpike between mile markers 340 and 359.
 Interstate 95 in Pennsylvania between mile markers 9 and 40.
 Interstate 76 in Pennsylvania between mile markers 338 and 351.
 Interstate 76 in New Jersey between mile markers 0 and 3.
 Interstate 195 in New Jersey between mile markers 0 and 3.
 Interstate 295 in New Jersey between mile markers 4 and 73, and
between mile markers 75 and 76.
 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 31 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 3961 7488 3958 7557 3985 7532 4015 7517
      4034 7468 4005 7465
TIME...MOT...LOC 0147Z 248DEG 30KT 4000 7521 3988 7524 3966 7544 

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

Staarmann

1 follow-up statement

235 
WWUS51 KPHI 180204
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1004 PM EDT Sat Jul 17 2021

NJC005-007-015-021-033-PAC017-045-091-101-180230-
/O.CON.KPHI.SV.W.0199.000000T0000Z-210718T0230Z/
Salem NJ-Camden NJ-Mercer NJ-Gloucester NJ-Burlington NJ-
Montgomery PA-Bucks PA-Philadelphia PA-Delaware PA-
1004 PM EDT Sat Jul 17 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 PM EDT
FOR NORTHERN SALEM...CAMDEN...CENTRAL MERCER...GLOUCESTER...
NORTHWESTERN BURLINGTON...SOUTHEASTERN MONTGOMERY...SOUTHEASTERN
BUCKS...PHILADELPHIA AND SOUTHEASTERN DELAWARE COUNTIES...

At 1003 PM EDT, severe thunderstorms were located along a line
extending from Feasterville-Trevose to Cherry Hill Mall to Woodstown,
moving east at 40 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, Trenton, Camden, Gloucester City, Cherry Hill,
Bensalem, Evesham, Mount Laurel, Ewing, Willingboro, Deptford,
Voorhees, Medford, West Deptford, Glassboro, Lindenwold, Pennsville,
Lumberton, Florence and Bellmawr.

This includes the following highways...
 New Jersey Turnpike between exits 1 and 7A.
 Pennsylvania Turnpike between mile markers 340 and 359.
 Interstate 95 in Pennsylvania between mile markers 9 and 40.
 Interstate 76 in Pennsylvania between mile markers 338 and 351.
 Interstate 76 in New Jersey between mile markers 0 and 3.
 Interstate 195 in New Jersey between mile markers 0 and 3.
 Interstate 295 in New Jersey between mile markers 4 and 73, and
between mile markers 75 and 76.
 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 31 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 3961 7488 3958 7557 3985 7532 4015 7517
      4034 7468 4005 7465
TIME...MOT...LOC 0203Z 247DEG 33KT 4013 7498 3994 7503 3967 7535 

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

Staarmann

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 8:00 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Mercer, Monmouth	45 min
Jul 17, 8:09 PM EDT	Flash Flood Warning	PHI	Mercer, Somerset	4 hr
Jul 17, 8:35 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Gloucester	40 min
Jul 17, 8:36 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean, Somerset	54 min
Jul 17, 8:46 PM EDT	Special Marine Warning	PHI		59 min
Jul 17, 8:53 PM EDT	Areal Flood Advisory	PHI	Mercer, Middlesex, Monmouth	3 hr
Jul 17, 9:25 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester, Salem	2 hr
Jul 17, 9:27 PM EDT	Severe Thunderstorm Warning	PHI	Gloucester, Salem	48 min
Jul 17, 9:30 PM EDT	Severe Thunderstorm Warning	PHI	Cape May	29 min
Jul 17, 9:36 PM EDT	Flash Flood Warning	PHI	Camden, Gloucester, Salem	2 hr
Jul 17, 9:44 PM EDT	Special Marine Warning	PHI		61 min
Jul 17, 10:21 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean	54 min
Jul 17, 10:22 PM EDT	Tornado Warning	PHI	Burlington, Monmouth, Ocean	23 min
Jul 17, 10:27 PM EDT	Special Weather Statement	PHI	Burlington, Camden	33 min
Jul 17, 10:38 PM EDT	Tornado Warning	PHI	Burlington, Monmouth, Ocean	16 min
Jul 17, 10:43 PM EDT	Flash Flood Warning	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean	79 min
Jul 17, 10:47 PM EDT	Special Marine Warning	PHI		118 min
Jul 17, 10:51 PM EDT	Special Marine Warning	PHI		114 min
Jul 17, 11:07 PM EDT	Special Weather Statement	PHI	Middlesex	38 min
Jul 17, 11:08 PM EDT	Areal Flood Warning	PHI	Hunterdon	12 hr
Jul 17, 11:11 PM EDT	Special Weather Statement	PHI	Monmouth, Ocean	34 min
Jul 17, 11:20 PM EDT	Special Marine Warning	PHI		115 min
Jul 17, 11:26 PM EDT	Areal Flood Warning	PHI	Somerset	10 hr
Jul 18, 2:41 AM EDT	Areal Flood Warning	PHI	Mercer	4 hr
Jul 18, 3:48 AM EDT	River Flood Warning	PHI	Mercer	3 hr
Jul 18, 9:08 AM EDT	Areal Flood Warning	PHI	Somerset	2 hr
Jul 18, 11:03 AM EDT	River Flood Warning	PHI	Middlesex, Somerset	88 min
Jul 17, 8:44 PM EDT	Areal Flood Advisory	PHI	Chester, Montgomery	82 min
Jul 17, 8:57 PM EDT	Severe Thunderstorm Warning	PHI	Chester	48 min
Jul 17, 9:15 PM EDT	Areal Flood Advisory	PHI	Delaware, Montgomery, Philadelphia	2 hr

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.