Alert archive / New Jersey / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 138, NWS Philadelphia/Mount Holly

July 6, 20216 counties in New Jersey; Bucks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 6, 2021, 9:29 PM EDT for 6 counties in New Jersey; Bucks County, Pennsylvania. It was in force for 61 min. 2 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 6, 2021, 9:29 PM EDT (01:29 UTC)
Expired: Jul 6, 2021, 10:30 PM EDT
In force: 61 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

Counties Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Morris County, NJ, Somerset County, NJ, Bucks County, PA

The radar

The Philadelphia radar (KDIX), 65 km from the middle of the area, began a volume at 01:28 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 6, 9:31 PM EDT	HAIL 1	3 Nw Pennington, NJ	MPING REPORT.
Jul 6, 9:40 PM EDT	HAIL 0.5	Washington Crossing, PA	REPORT FROM MPING: HALF-INCH (0.50 IN.).

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 6, 1:32 PM EDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 1.5 hours before the alert went out and 125 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: 1647 J/kg
Mixed-layer CIN: -86 J/kg
Mixed-layer LCL: 876 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: 93 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 3.3

Open this sounding in Storm Lab

The text

As transmitted.

932 
WUUS51 KPHI 070129
SVRPHI
NJC019-021-023-025-027-035-PAC017-070230-
/O.NEW.KPHI.SV.W.0138.210707T0129Z-210707T0230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
929 PM EDT Tue Jul 6 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southeastern Hunterdon County in northwestern New Jersey...
  Southeastern Morris County in northern New Jersey...
  Mercer County in central New Jersey...
  Somerset County in northern New Jersey...
  Monmouth County in central New Jersey...
  Middlesex County in northern New Jersey...
  East central Bucks County in southeastern Pennsylvania...

* Until 1030 PM EDT.

* At 929 PM EDT, severe thunderstorms were located along a line
  extending from Madison to White House Station to near New Hope,
  moving east at 35 mph.

  HAZARD...60 mph wind gusts and half dollar 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...
  New Brunswick, Perth Amboy, Long Branch, Morristown, Asbury Park,
  Somerville, Sandy Hook, Somerset, Edison, Middletown, Old Bridge,
  Howell, East Brunswick, Bridgewater, South Brunswick, Sayreville,
  North Brunswick, Marlboro, Manalapan and Ewing.

This includes the following highways...
 New Jersey Turnpike between exits 8A and 13.
 Interstate 78 in New Jersey between mile markers 28 and 42.
 Interstate 195 in New Jersey between mile markers 28 and 34.
 Interstate 295 in New Jersey between mile markers 65 and 75.
 Interstate 287 in New Jersey between mile markers 0 and 31, and
between mile markers 34 and 35.
 Garden State Parkway between mile markers 97 and 134.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should move immediately to shelter inside a strong building. Stay
away from windows.

In addition to large hail and damaging winds, frequent cloud to
ground lightning is occurring with these storms. Move indoors
immediately. 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 4013 7402 4029 7498 4059 7480 4082 7441
      4082 7434 4079 7437 4074 7437 4067 7446
      4065 7440 4060 7446 4060 7421 4056 7421
      4050 7428 4047 7427 4044 7420 4045 7413
      4041 7398 4048 7402 4048 7401 4043 7397
TIME...MOT...LOC 0129Z 268DEG 29KT 4075 7444 4060 7475 4036 7489 

HAIL...1.25IN
WIND...60MPH
 
$$

Staarmann

2 follow-up statements

331 
WWUS51 KPHI 070153
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
953 PM EDT Tue Jul 6 2021

NJC027-070202-
/O.CAN.KPHI.SV.W.0138.000000T0000Z-210707T0230Z/
Morris NJ-
953 PM EDT Tue Jul 6 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN MORRIS COUNTY IS
CANCELLED...

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

LAT...LON 4013 7402 4029 7498 4059 7480 4067 7446
      4065 7441 4060 7446 4060 7421 4056 7421
      4055 7425 4050 7428 4047 7427 4044 7420
      4045 7413 4041 7403 4046 7401 4041 7399
      4042 7398 4048 7402 4043 7397
TIME...MOT...LOC 0152Z 276DEG 36KT 4063 7442 4034 7414 4029 7469 

$$

NJC019-021-023-025-035-PAC017-070230-
/O.CON.KPHI.SV.W.0138.000000T0000Z-210707T0230Z/
Hunterdon NJ-Mercer NJ-Somerset NJ-Monmouth NJ-Middlesex NJ-Bucks PA-
953 PM EDT Tue Jul 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 PM EDT
FOR SOUTHEASTERN HUNTERDON...MERCER...SOMERSET...MONMOUTH...MIDDLESEX
AND EAST CENTRAL BUCKS COUNTIES...

At 952 PM EDT, severe thunderstorms were located along a line
extending from Plainfield to Lincroft to near Lawrenceville, moving
east at 40 mph.

HAZARD...60 mph wind gusts and half dollar 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...
New Brunswick, Perth Amboy, Long Branch, Asbury Park, Somerville,
Sandy Hook, Somerset, Edison, Middletown, Old Bridge, Howell, East
Brunswick, Bridgewater, South Brunswick, Sayreville, North Brunswick,
Marlboro, Manalapan, Ewing and Carteret.

This includes the following highways...
 New Jersey Turnpike between exits 8A and 13.
 Interstate 78 in New Jersey between mile markers 36 and 42.
 Interstate 195 in New Jersey between mile markers 28 and 34.
 Interstate 295 in New Jersey between mile markers 65 and 75.
 Interstate 287 in New Jersey between mile markers 0 and 20.
 Garden State Parkway between mile markers 97 and 134.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should seek shelter inside a well-built structure and away from
windows.

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 4013 7402 4029 7498 4059 7480 4067 7446
      4065 7441 4060 7446 4060 7421 4056 7421
      4055 7425 4050 7428 4047 7427 4044 7420
      4045 7413 4041 7403 4046 7401 4041 7399
      4042 7398 4048 7402 4043 7397
TIME...MOT...LOC 0152Z 276DEG 36KT 4063 7442 4034 7414 4029 7469 

HAIL...1.25IN
WIND...60MPH
 
$$

Staarmann

600 
WWUS51 KPHI 070215
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1015 PM EDT Tue Jul 6 2021

NJC019-PAC017-070225-
/O.CAN.KPHI.SV.W.0138.000000T0000Z-210707T0230Z/
Hunterdon NJ-Bucks PA-
1015 PM EDT Tue Jul 6 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN HUNTERDON AND
EAST CENTRAL BUCKS COUNTIES IS CANCELLED...

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

LAT...LON 4041 7399 4041 7397 4013 7402 4026 7483
      4032 7489 4060 7446 4060 7421 4056 7421
      4055 7425 4050 7428 4047 7427 4044 7420
      4045 7413 4041 7403 4047 7401 4043 7397
TIME...MOT...LOC 0215Z 307DEG 23KT 4025 7395 4029 7475 

$$

NJC021-023-025-035-070230-
/O.CON.KPHI.SV.W.0138.000000T0000Z-210707T0230Z/
Mercer NJ-Somerset NJ-Monmouth NJ-Middlesex NJ-
1015 PM EDT Tue Jul 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 PM EDT
FOR MERCER...SOUTHEASTERN SOMERSET...MONMOUTH AND MIDDLESEX
COUNTIES...

At 1015 PM EDT, severe thunderstorms were located along a line
extending from near Elberon to Lawrenceville, moving southeast 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...
New Brunswick, Perth Amboy, Long Branch, Asbury Park, Sandy Hook,
Somerset, Edison, Middletown, Old Bridge, Howell, East Brunswick,
South Brunswick, Sayreville, North Brunswick, Marlboro, Manalapan,
Ewing, Carteret, Tinton Falls and Holmdel.

This includes the following highways...
 New Jersey Turnpike between exits 8A and 13.
 Interstate 195 in New Jersey between mile markers 28 and 34.
 Interstate 295 in New Jersey between mile markers 65 and 75.
 Interstate 287 in New Jersey between mile markers 0 and 11.
 Garden State Parkway between mile markers 97 and 134.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should seek shelter inside a well-built structure and away from
windows.

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 4041 7399 4041 7397 4013 7402 4026 7483
      4032 7489 4060 7446 4060 7421 4056 7421
      4055 7425 4050 7428 4047 7427 4044 7420
      4045 7413 4041 7403 4047 7401 4043 7397
TIME...MOT...LOC 0215Z 307DEG 23KT 4025 7395 4029 7475 

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 6, 8:03 PM EDT	Special Weather Statement	PHI	Burlington, Ocean	42 min
Jul 6, 8:11 PM EDT	Special Marine Warning	PHI		82 min
Jul 6, 8:24 PM EDT	Special Marine Warning	PHI		2 hr
Jul 6, 8:29 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Warren	46 min
Jul 6, 8:37 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Middlesex, Monmouth, Morris, Somerset	53 min
Jul 6, 8:50 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Monmouth, Somerset	40 min
Jul 6, 9:04 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Somerset	41 min
Jul 6, 9:10 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Middlesex, Monmouth, Morris, Somerset and 1 more	2 hr
Jul 6, 9:37 PM EDT	Special Marine Warning	PHI		113 min
Jul 6, 9:48 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean	57 min
Jul 6, 10:21 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden	39 min
Jul 6, 10:50 PM EDT	Areal Flood Advisory	PHI	Monmouth, Ocean	2 hr
Jul 6, 10:54 PM EDT	Special Weather Statement	PHI	Burlington	51 min
Jul 6, 11:11 PM EDT	Special Weather Statement	PHI	Burlington	19 min
Jul 6, 11:30 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Ocean	45 min
Jul 6, 11:39 PM EDT	Special Marine Warning	PHI		66 min
Jul 6, 11:55 PM EDT	Special Weather Statement	PHI	Monmouth	50 min
Jul 7, 12:01 AM EDT	Areal Flood Advisory	PHI	Middlesex, Monmouth	71 min
Jul 7, 12:10 AM EDT	Special Marine Warning	PHI		95 min
Jul 7, 11:19 AM EDT	Tropical Storm Watch	PHI	Atlantic, Burlington, Cape May, Monmouth, Ocean	18 hr
Jul 7, 3:32 PM EDT	Flash Flood Watch	PHI	Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 10 more	42 hr
Jul 6, 8:16 PM EDT	Special Weather Statement	PHI	Lehigh	29 min
Jul 6, 10:08 PM EDT	Special Weather Statement	PHI	Philadelphia	37 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.