Alert archive / New Jersey / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 55, NWS Philadelphia/Mount Holly

June 4, 20214 counties in New Jersey; Bucks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 4, 2021, 3:23 PM EDT for 4 counties in New Jersey; Bucks County, Pennsylvania. It was in force for 67 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: Jun 4, 2021, 3:23 PM EDT (19:23 UTC)
Expired: Jun 4, 2021, 4:30 PM EDT
In force: 67 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

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

The radar

The Philadelphia radar (KDIX), 62 km from the middle of the area, began a volume at 19:23 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 4, 3:53 PM EDT	TSTM WND DMG	1 Nne East Brunswick, NJ	DOWNED TREE ON WIRES NEAR SUNSET BOULEVARD. TIME ESTIMATED FROM RADAR.
Jun 4, 4:03 PM EDT	TSTM WND GST 54	Woodbridge, NJ

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 4, 3:09 PM EDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 7.4 hours before the alert went out and 134 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: 233 J/kg
Mixed-layer CIN: -50 J/kg
Mixed-layer LCL: 526 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 30 m²/s²
0-3 km storm-relative helicity: 95 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

240 
WUUS51 KPHI 041923
SVRPHI
NJC019-021-023-035-PAC017-042030-
/O.NEW.KPHI.SV.W.0055.210604T1923Z-210604T2030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
323 PM EDT Fri Jun 4 2021

The National Weather Service in Mount Holly NJ has issued a

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

* Until 430 PM EDT.

* At 322 PM EDT, a severe thunderstorm was located over Skillman, or
  12 miles southwest of Somerville, moving southeast 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...
  New Brunswick, Perth Amboy, Somerville, Somerset, Edison, Old
  Bridge, East Brunswick, Bridgewater, South Brunswick, Sayreville,
  North Brunswick, Ewing, Carteret, Middlesex, Princeton, Bound
  Brook, Manville, Jamesburg, Hightstown and Cranbury.

People at the Middlesex County Mega Site should seek safe shelter
immediately!

This includes the following highways...
 New Jersey Turnpike between exits 8A and 12.
 Interstate 295 in New Jersey between mile markers 67 and 75.
 Interstate 287 in New Jersey between mile markers 0 and 18.
 Garden State Parkway between mile markers 121 and 134.

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 4056 7421 4055 7425 4050 7426 4050 7428
      4047 7427 4045 7423 4027 7441 4026 7444
      4027 7494 4060 7478 4062 7443 4060 7446
      4061 7431 4059 7429 4059 7420
TIME...MOT...LOC 1922Z 293DEG 27KT 4042 7475 

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

Davis

3 follow-up statements

676 
WWUS51 KPHI 041942
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
342 PM EDT Fri Jun 4 2021

NJC019-PAC017-041952-
/O.CAN.KPHI.SV.W.0055.000000T0000Z-210604T2030Z/
Hunterdon NJ-Bucks PA-
342 PM EDT Fri Jun 4 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN HUNTERDON AND
SOUTHEASTERN BUCKS COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
central and northern New Jersey.

LAT...LON 4056 7421 4055 7425 4050 7426 4050 7428
      4047 7427 4045 7423 4027 7441 4026 7444
      4027 7476 4060 7468 4062 7443 4060 7446
      4061 7431 4059 7429 4059 7420
TIME...MOT...LOC 1942Z 293DEG 27KT 4036 7457 

$$

NJC021-023-035-042030-
/O.CON.KPHI.SV.W.0055.000000T0000Z-210604T2030Z/
Mercer NJ-Somerset NJ-Middlesex NJ-
342 PM EDT Fri Jun 4 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM EDT
FOR CENTRAL MERCER...SOUTHERN SOMERSET AND MIDDLESEX COUNTIES...

At 342 PM EDT, a severe thunderstorm was located over Princeton
Meadows, or 10 miles southwest of New Brunswick, moving southeast 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...
New Brunswick, Perth Amboy, Somerville, Somerset, Edison, Old Bridge,
East Brunswick, Bridgewater, South Brunswick, Sayreville, North
Brunswick, Carteret, Middlesex, Princeton, Bound Brook, Manville,
Jamesburg, Hightstown, Cranbury and Rocky Hill.

People at the Middlesex County Mega Site should seek safe shelter
immediately!

This includes the following highways...
 New Jersey Turnpike between exits 8A and 12.
 Interstate 295 in New Jersey between mile markers 67 and 70.
 Interstate 287 in New Jersey between mile markers 0 and 18.
 Garden State Parkway between mile markers 121 and 134.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4056 7421 4055 7425 4050 7426 4050 7428
      4047 7427 4045 7423 4027 7441 4026 7444
      4027 7476 4060 7468 4062 7443 4060 7446
      4061 7431 4059 7429 4059 7420
TIME...MOT...LOC 1942Z 293DEG 27KT 4036 7457 

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

Davis

249 
WWUS51 KPHI 042005
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
405 PM EDT Fri Jun 4 2021

NJC021-023-035-042030-
/O.CON.KPHI.SV.W.0055.000000T0000Z-210604T2030Z/
Mercer NJ-Somerset NJ-Middlesex NJ-
405 PM EDT Fri Jun 4 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM EDT
FOR EAST CENTRAL MERCER...SOUTHEASTERN SOMERSET AND MIDDLESEX
COUNTIES...

At 405 PM EDT, a severe thunderstorm was located over Yorketown, or
14 miles south of New Brunswick, moving southeast at 30 mph.

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...
New Brunswick, Perth Amboy, Somerset, Edison, Old Bridge, East
Brunswick, South Brunswick, Sayreville, North Brunswick, Carteret,
Jamesburg, Hightstown, Cranbury, Princeton Meadows, Colonia,
Brownville, Dayton, North Brunswick Township, Clearbrook Park and
Whittingham.

People at the Middlesex County Mega Site should seek safe shelter
immediately!

This includes the following highways...
 New Jersey Turnpike between exits 8A and 12.
 Interstate 287 in New Jersey between mile markers 0 and 8.
 Garden State Parkway between mile markers 121 and 134.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4055 7425 4050 7426 4050 7428 4047 7427
      4045 7423 4027 7441 4026 7458 4044 7457
      4060 7445 4061 7431 4059 7429 4059 7421
      4056 7421
TIME...MOT...LOC 2005Z 293DEG 27KT 4029 7436 

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

Davis

188 
WWUS51 KPHI 042024
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
424 PM EDT Fri Jun 4 2021

NJC021-023-035-042033-
/O.EXP.KPHI.SV.W.0055.000000T0000Z-210604T2030Z/
Mercer NJ-Somerset NJ-Middlesex NJ-
424 PM EDT Fri Jun 4 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL MERCER...
SOUTHEASTERN SOMERSET AND MIDDLESEX COUNTIES WILL EXPIRE AT 430 PM
EDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.  However gusty
winds and heavy rain are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
northern and central New Jersey.

LAT...LON 4055 7425 4050 7426 4050 7428 4047 7427
      4045 7423 4027 7441 4026 7458 4044 7457
      4060 7445 4061 7431 4059 7429 4059 7421
      4056 7421
TIME...MOT...LOC 2023Z 293DEG 27KT 4024 7420 

$$

Davis

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 3, 8:14 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex, Monmouth, Ocean	19 min
Jun 3, 8:44 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer, Middlesex, Monmouth	30 min
Jun 3, 8:55 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex, Monmouth	10 min
Jun 4, 1:07 PM EDT	Special Weather Statement	PHI	Sussex	38 min
Jun 4, 1:45 PM EDT	Areal Flood Advisory	PHI	Warren	97 min
Jun 4, 1:49 PM EDT	Severe Thunderstorm Warning	PHI	Sussex, Warren	41 min
Jun 4, 2:43 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Middlesex, Morris, Somerset, Sussex, Warren	62 min
Jun 4, 2:49 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Middlesex, Morris, Somerset, Sussex, Warren	70 min
Jun 4, 3:16 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Hunterdon, Mercer, Middlesex, Monmouth and 1 more	98 min
Jun 4, 3:18 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer	42 min
Jun 4, 3:46 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Mercer	44 min
Jun 4, 4:12 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean	63 min
Jun 4, 4:20 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Gloucester	40 min
Jun 4, 4:22 PM EDT	Special Marine Warning	PHI		53 min
Jun 4, 4:23 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Ocean	52 min
Jun 4, 4:30 PM EDT	Areal Flood Advisory	PHI	Middlesex, Monmouth, Ocean	63 min
Jun 4, 5:09 PM EDT	Special Marine Warning	PHI		2 hr
Jun 4, 5:12 PM EDT	Severe Thunderstorm Warning	PHI	Ocean	18 min
Jun 4, 5:32 PM EDT	Special Marine Warning	PHI		58 min
Jun 4, 6:18 PM EDT	Special Weather Statement	PHI	Atlantic	42 min
Jun 4, 6:27 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Cape May, Cumberland	48 min
Jun 4, 7:13 PM EDT	Special Marine Warning	PHI		62 min
Jun 4, 1:02 PM EDT	Special Weather Statement	PHI	Lehigh	28 min
Jun 4, 1:29 PM EDT	Areal Flood Advisory	PHI	Berks, Lehigh	2 hr
Jun 4, 2:21 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Lehigh, Montgomery	21 min
Jun 4, 2:24 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery	51 min
Jun 4, 2:27 PM EDT	Severe Thunderstorm Warning	PHI	Berks	48 min
Jun 4, 3:14 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery, Philadelphia	46 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.