Alert archive / New Jersey / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 128, NWS Philadelphia/Mount Holly

July 6, 2021Hunterdon County, Somerset County, Warren County, New Jersey; Bucks County, Lehigh County, Northampton County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 6, 2021, 5:55 PM EDT for Hunterdon County, Somerset County, Warren County, New Jersey; Bucks County, Lehigh County, Northampton County, Pennsylvania. It was in force for 65 min. 7 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, 5:55 PM EDT (21:55 UTC)
Expired: Jul 6, 2021, 7:00 PM EDT
In force: 65 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Hunterdon County, NJ, Somerset County, NJ, Warren County, NJ, Bucks County, PA, Lehigh County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 101 km from the middle of the area, began a volume at 21:58 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, 5:58 PM EDT	TSTM WND DMG	1 E Pen Argyl, PA	TREE DOWN. REPORT VIA SOCIAL MEDIA. T ESTIMATED FROM RADAR.
Jul 6, 6:17 PM EDT	HAIL 0.75	Whitehall Twp, PA
Jul 6, 6:19 PM EDT	TSTM WND DMG	Laurys Station, PA	TREE DOWN IN WIRES.
Jul 6, 6:20 PM EDT	HAIL 0.75	Bethlehem, PA
Jul 6, 6:24 PM EDT	HAIL 0.5	1 N Bethlehem Twp, PA	REPORT FROM MPING: HALF-INCH (0.50 IN.).
Jul 6, 7:00 PM EDT	TSTM WND DMG	Raritan, NJ	DAMAGE TO SEVEN PINE TREES. REPORT VIA SOCIAL MEDIA.
Jul 6, 7:00 PM EDT	NON-TSTM WND DMG	Raritan, NJ	DAMAGE TO SEVEN PINE TREES. REPORT VIA SOCIAL MEDIA.

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 12:00Z, 9.9 hours before the alert went out and 187 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: 230 J/kg
Mixed-layer CIN: -195 J/kg
Mixed-layer LCL: 1202 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 139 m²/s²
0-3 km storm-relative helicity: 184 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

342 
WUUS51 KPHI 062155
SVRPHI
NJC019-035-041-PAC017-077-095-062300-
/O.NEW.KPHI.SV.W.0128.210706T2155Z-210706T2300Z/

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

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Hunterdon County in northwestern New Jersey...
  Southwestern Warren County in northwestern New Jersey...
  Northwestern Somerset County in northern New Jersey...
  Northeastern Lehigh County in eastern Pennsylvania...
  Northwestern Bucks County in southeastern Pennsylvania...
  Northampton County in eastern Pennsylvania...

* Until 700 PM EDT.

* At 555 PM EDT, severe thunderstorms were located along a line
  extending from near Hope to near Belfast to Coffeetown, 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...
  Allentown, Easton, Somerville, Bethlehem, Bridgewater, Forks, Bound
  Brook, Manville, Northampton, Byram, Wilson, Bedminster,
  Washington, Hellertown, Nazareth, Bangor, Flemington, Tinicum, High
  Bridge and Pen Argyl.

This includes the following highways...
 Northeast Extension between mile markers 58 and 66.
 Interstate 78 in Pennsylvania between mile markers 58 and 76.
 Interstate 78 in New Jersey between mile markers 0 and 30.
 Interstate 287 in New Jersey between mile markers 14 and 20.

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 4057 7454 4037 7506 4065 7569 4081 7552
      4083 7538 4086 7532 4092 7507 4074 7483
      4074 7480
TIME...MOT...LOC 2155Z 283DEG 32KT 4087 7502 4080 7533 4067 7556 

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

Staarmann

4 follow-up statements

194 
WWUS51 KPHI 062207
SVSPHI

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

NJC019-035-041-PAC017-077-095-062300-
/O.CON.KPHI.SV.W.0128.000000T0000Z-210706T2300Z/
Hunterdon NJ-Warren NJ-Somerset NJ-Lehigh PA-Bucks PA-Northampton PA-
607 PM EDT Tue Jul 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR HUNTERDON...SOUTHWESTERN WARREN...NORTHWESTERN SOMERSET...
NORTHEASTERN LEHIGH...NORTH CENTRAL BUCKS AND NORTHAMPTON COUNTIES...

At 605 PM EDT, severe thunderstorms were located along a line
extending from near Oxford to Belfast to near Northampton, moving 
east at 35 mph. This storm has a history of producing quarter sized 
hail in Northampton County.

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

SOURCE...Trained weather spotters.

IMPACT...Minor damage to vehicles is possible. Wind damage to roofs, 
         siding, trees, and power lines is possible.

Locations impacted include...
Allentown, Easton, Somerville, Bethlehem, Bridgewater, Forks, Bound
Brook, Manville, Northampton, Byram, Wilson, Washington, Hellertown,
Nazareth, Bangor, Flemington, Tinicum, High Bridge, Pen Argyl and
Wind Gap.

This includes the following highways...
 Northeast Extension between mile markers 62 and 66.
 Interstate 78 in Pennsylvania between mile markers 63 and 76.
 Interstate 78 in New Jersey between mile markers 0 and 30.
 Interstate 287 in New Jersey between mile markers 14 and 20.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEEK SHELTER NOW inside a sturdy structure and stay away from 
windows.
 
Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4057 7454 4037 7506 4069 7565 4081 7552
      4083 7538 4086 7532 4092 7507 4074 7483
      4074 7480
TIME...MOT...LOC 2205Z 282DEG 32KT 4080 7495 4079 7525 4066 7548 

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

Staarmann

023 
WWUS51 KPHI 062226
SVSPHI

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

NJC019-035-041-PAC017-077-095-062300-
/O.CON.KPHI.SV.W.0128.000000T0000Z-210706T2300Z/
Hunterdon NJ-Warren NJ-Somerset NJ-Lehigh PA-Bucks PA-Northampton PA-
626 PM EDT Tue Jul 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR HUNTERDON...SOUTHWESTERN WARREN...NORTHWESTERN SOMERSET...
NORTHEASTERN LEHIGH...NORTH CENTRAL BUCKS AND NORTHAMPTON COUNTIES...

At 625 PM EDT, severe thunderstorms were located along a line
extending from near Long Valley to Clinton to near Bethlehem, moving
east at 40 mph.

HAZARD...70 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Minor damage to vehicles is possible. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings.

Locations impacted include...
Allentown, Easton, Somerville, Bethlehem, Bridgewater, Forks, Bound
Brook, Manville, Northampton, Byram, Wilson, Washington, Hellertown,
Nazareth, Bangor, Flemington, Tinicum, High Bridge, Pen Argyl and
Wind Gap.

This includes the following highways...
 Northeast Extension between mile markers 62 and 66.
 Interstate 78 in Pennsylvania between mile markers 63 and 76.
 Interstate 78 in New Jersey between mile markers 0 and 30.
 Interstate 287 in New Jersey between mile markers 14 and 20.

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.

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

&&

LAT...LON 4057 7454 4037 7506 4069 7565 4081 7552
      4083 7538 4086 7532 4089 7520 4085 7497
      4074 7483 4074 7480
TIME...MOT...LOC 2225Z 286DEG 35KT 4076 7482 4063 7494 4065 7534 

HAIL...1.00IN
WIND...70MPH
 
$$

Staarmann

421 
WWUS51 KPHI 062243
SVSPHI

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

PAC077-062253-
/O.CAN.KPHI.SV.W.0128.000000T0000Z-210706T2300Z/
Lehigh PA-
643 PM EDT Tue Jul 6 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN LEHIGH 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 1000 PM EDT for
northern and northwestern New Jersey...and eastern and southeastern
Pennsylvania.

LAT...LON 4057 7454 4037 7506 4064 7534 4073 7533
      4078 7525 4084 7519 4080 7491 4074 7483
      4074 7480
TIME...MOT...LOC 2243Z 282DEG 32KT 4073 7463 4060 7475 4064 7517 

$$

NJC019-035-041-PAC017-095-062300-
/O.CON.KPHI.SV.W.0128.000000T0000Z-210706T2300Z/
Hunterdon NJ-Warren NJ-Somerset NJ-Bucks PA-Northampton PA-
643 PM EDT Tue Jul 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR HUNTERDON...SOUTHWESTERN WARREN...NORTHWESTERN SOMERSET...NORTH
CENTRAL BUCKS AND SOUTHEASTERN NORTHAMPTON COUNTIES...

At 643 PM EDT, severe thunderstorms were located along a line
extending from Peapack And Gladstone to White House Station to Alpha,
moving east at 35 mph.

HAZARD...70 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Minor damage to vehicles is possible. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings.

Locations impacted include...
Easton, Somerville, Bethlehem, Bridgewater, Forks, Bound Brook,
Manville, Byram, Wilson, Washington, Nazareth, Flemington, Tinicum,
High Bridge, Clinton, Belvidere, Harmony, Oxford, Alpha and Glen
Gardner.

This includes the following highways...
 Interstate 78 in Pennsylvania between mile markers 70 and 76.
 Interstate 78 in New Jersey between mile markers 0 and 30.
 Interstate 287 in New Jersey between mile markers 14 and 20.

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.

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

&&

LAT...LON 4057 7454 4037 7506 4064 7534 4073 7533
      4078 7525 4084 7519 4080 7491 4074 7483
      4074 7480
TIME...MOT...LOC 2243Z 282DEG 32KT 4073 7463 4060 7475 4064 7517 

HAIL...1.00IN
WIND...70MPH
 
$$

Staarmann

408 
WWUS51 KPHI 062253
SVSPHI

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

PAC095-062303-
/O.CAN.KPHI.SV.W.0128.000000T0000Z-210706T2300Z/
Northampton PA-
653 PM EDT Tue Jul 6 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN NORTHAMPTON
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 1000 PM EDT for
northern and northwestern New Jersey...and eastern and southeastern
Pennsylvania.

LAT...LON 4057 7454 4037 7506 4060 7521 4063 7519
      4065 7520 4068 7517 4068 7520 4073 7518
      4075 7519 4078 7517 4077 7513 4082 7508
      4080 7491 4074 7483 4074 7480
TIME...MOT...LOC 2253Z 283DEG 26KT 4051 7472 4060 7490 4058 7512 

$$

NJC019-035-041-PAC017-062300-
/O.CON.KPHI.SV.W.0128.000000T0000Z-210706T2300Z/
Hunterdon NJ-Warren NJ-Somerset NJ-Bucks PA-
653 PM EDT Tue Jul 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR HUNTERDON...SOUTHWESTERN WARREN...NORTHWESTERN SOMERSET AND NORTH
CENTRAL BUCKS COUNTIES...

At 653 PM EDT, severe thunderstorms were located along a line
extending from Flagtown to near Clinton to Milford, moving east at 30
mph. This storm has a history of producing wind damage.

HAZARD...70 mph wind gusts and quarter size hail.

SOURCE...Public.

IMPACT...Minor damage to vehicles is possible. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings.

Locations impacted include...
Somerville, Bridgewater, Bound Brook, Manville, Byram, Washington,
Flemington, Tinicum, High Bridge, Clinton, Harmony, Oxford, Alpha,
Glen Gardner, Hampton, Frenchtown, Lebanon, Milford, Califon and
Bloomsbury.

This includes the following highways...
 Interstate 78 in New Jersey between mile markers 0 and 30.
 Interstate 287 in New Jersey between mile markers 14 and 20.

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.

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

&&

LAT...LON 4057 7454 4037 7506 4060 7521 4063 7519
      4065 7520 4068 7517 4068 7520 4073 7518
      4075 7519 4078 7517 4077 7513 4082 7508
      4080 7491 4074 7483 4074 7480
TIME...MOT...LOC 2253Z 283DEG 26KT 4051 7472 4060 7490 4058 7512 

HAIL...1.00IN
WIND...70MPH
 
$$

Staarmann

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 6, 3:53 AM EDT	Small Craft Advisory	PHI		22 hr
Jul 6, 5:11 PM EDT	Severe Thunderstorm Warning	PHI	Burlington	49 min
Jul 6, 5:15 PM EDT	Severe Thunderstorm Warning	PHI	Morris, Sussex, Warren	60 min
Jul 6, 5:46 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Morris, Somerset, Sussex, Warren	59 min
Jul 6, 6:13 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden	31 min
Jul 6, 6:17 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Middlesex, Monmouth, Somerset	58 min
Jul 6, 6:33 PM EDT	Special Marine Warning	PHI		117 min
Jul 6, 6:41 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Monmouth, Somerset	64 min
Jul 6, 7:01 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Hunterdon, Mercer, Middlesex, Monmouth, Ocean and 1 more	59 min
Jul 6, 7:59 PM EDT	Severe Thunderstorm Warning	PHI	Mercer, Middlesex, Monmouth, Ocean, Somerset	61 min
Jul 6, 4:23 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Montgomery	52 min
Jul 6, 4:29 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Monroe	76 min
Jul 6, 5:08 PM EDT	Special Weather Statement	PHI	Carbon	37 min
Jul 6, 5:34 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	41 min
Jul 6, 7:50 PM EDT	Special Weather Statement	PHI	Lehigh	25 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.