A warm and very humid air mass was in place over the mid-Atlantic on July 17. A warm front which had sagged south into the region on the night of the 16th pushed back to the north on the morning of the 17th. Meanwhile, a cold front slowly approached by evening, with a pre-frontal surface trough ahead of it. The presence of multiple synoptic and mesoscale boundaries led to a highly complex convective evolution. Several areas and multiple rounds of convection affected the eastern mid-Atlantic over about a 12 hour period from early afternoon on the 17th to a little after midnight on the 18th. With shear falling in the weak to moderate range, convection mainly took the form of multi-cellular and linear clusters, though some semi-discrete supercellular structures were noted at times. A number of storms became severe with damaging wind. A weak tornado was confirmed in Burlington County, NJ in association with a line of thunderstorms in the later evening. Areas of heavy rain and flash flooding also occurred due to the widespread and at times slow moving nature of the convection. Eventually, by later in the night, the approach of the cold front and significant overturning of the atmosphere from the day's convection caused remaining activity to weaken and shift offshore.

Thunderstorm Wind in HUNTERDON, NEW JERSEY
From 17-JUL-21 12:15:00 to 17-JUL-21 12:15:00 (EST-5)
Location: ROSEMONT
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

A tree was downed on NJ-29. All lanes were closed. Time estimated from radar.

Thunderstorm Wind in HUNTERDON, NEW JERSEY
From 17-JUL-21 16:10:00 to 17-JUL-21 16:10:00 (EST-5)
Location: FLEMINGTON
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A tree and wires were downed across a road in Flemington. Time estimated from radar.

Thunderstorm Wind in BURLINGTON, NEW JERSEY
From 17-JUL-21 19:55:00 to 17-JUL-21 19:55:00 (EST-5)
Location: MT HOLLY HALL FLD
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Measured by cwop station ew8027.

Thunderstorm Wind in HUNTERDON, NEW JERSEY
From 17-JUL-21 13:15:00 to 17-JUL-21 13:15:00 (EST-5)
Location: FAIRMOUNT
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: State Official

Trees were reported down in Tewksbury Twp. Time estimated from radar.

Thunderstorm Wind in HUNTERDON, NEW JERSEY
From 17-JUL-21 12:15:00 to 17-JUL-21 12:15:00 (EST-5)
Location: SERGEANTSVILLE
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: State Official

Trees were reported down around Delaware Twp. Time estimated from radar.

Thunderstorm Wind in HUNTERDON, NEW JERSEY
From 17-JUL-21 16:30:00 to 17-JUL-21 16:30:00 (EST-5)
Location: READINGTON ARPT
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: State Official

A downed tree blocked a road. Time estimated from radar.

Thunderstorm Wind in HUNTERDON, NEW JERSEY
From 17-JUL-21 17:15:00 to 17-JUL-21 17:15:00 (EST-5)
Location: LEBANON
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A tree and wires were downed. Time estimated from radar.

Thunderstorm Wind in HUNTERDON, NEW JERSEY
From 17-JUL-21 18:30:00 to 17-JUL-21 18:30:00 (EST-5)
Location: RINGOES
Magnitude: 50.00 EG
Crop damage: 0.00K
Reported by: Public

A tree was blown down into a house. Time estimated from radar.

Thunderstorm Wind in BURLINGTON, NEW JERSEY
From 17-JUL-21 19:25:00 to 17-JUL-21 19:25:00 (EST-5)
Location: FAIRVIEW
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Several trees were blown down. Time estimated from radar.

Thunderstorm Wind in BURLINGTON, NEW JERSEY
From 17-JUL-21 21:10:00 to 17-JUL-21 21:10:00 (EST-5)
Location: RIVERSIDE
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Several large limbs were blown down. Time estimated from radar.

Thunderstorm Wind in BURLINGTON, NEW JERSEY
From 17-JUL-21 21:14:00 to 17-JUL-21 21:14:00 (EST-5)
Location: BEVERLY
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Numerous tree limbs were down with power outages reported in Edgewater Park. Time estimated from radar. Public report relayed by off duty NWS employee.

Thunderstorm Wind in BURLINGTON, NEW JERSEY
From 17-JUL-21 21:20:00 to 17-JUL-21 21:20:00 (EST-5)
Location: BURLINGTON
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Several large tree limbs were downed in Burlington.

Thunderstorm Wind in BURLINGTON, NEW JERSEY
From 17-JUL-21 19:20:00 to 17-JUL-21 19:20:00 (EST-5)
Location: MT HOLLY ARPT
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Several large trees were downed. Time estimated from radar.

Funnel Cloud in MIDDLESEX, NEW JERSEY
From 17-JUL-21 14:07:00 to 17-JUL-21 14:07:00 (EST-5)
Location: AVENEL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Pictures and video were received of a funnel cloud and well-defined mesocyclone. No damage was reported from the area and there were no indications a tornado touchdown occurred.

Thunderstorm Wind in HUNTERDON, NEW JERSEY
From 17-JUL-21 12:35:00 to 17-JUL-21 12:35:00 (EST-5)
Location: FLEMINGTON
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: State Official

Trees were reported down around Raritan Twp. Time estimated from radar.

Thunderstorm Wind in HUNTERDON, NEW JERSEY
From 17-JUL-21 13:00:00 to 17-JUL-21 13:00:00 (EST-5)
Location: LEBANON
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: State Official

Trees were reported down in Lebanon and Clinton Twps. Time estimated from radar.

Hail in MIDDLESEX, NEW JERSEY
From 17-JUL-21 14:31:00 to 17-JUL-21 14:31:00 (EST-5)
Location: HOPELAWN
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in HUNTERDON, NEW JERSEY
From 17-JUL-21 17:43:00 to 17-JUL-21 17:43:00 (EST-5)
Location: MT AIRY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in HUNTERDON, NEW JERSEY
From 17-JUL-21 18:20:00 to 17-JUL-21 18:20:00 (EST-5)
Location: MT AIRY
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A few trees were snapped. Time estimated from radar.

Thunderstorm Wind in BURLINGTON, NEW JERSEY
From 17-JUL-21 21:20:00 to 17-JUL-21 21:20:00 (EST-5)
Location: HARTFORD
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

An mPing report of a tree or large limbs down.

Thunderstorm Wind in BURLINGTON, NEW JERSEY
From 17-JUL-21 21:32:00 to 17-JUL-21 21:32:00 (EST-5)
Location: GEORGETOWN
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A large tree was snapped and several large limbs were downed. Time estimated from radar.

Thunderstorm Wind in CAMDEN, NEW JERSEY
From 17-JUL-21 21:02:00 to 17-JUL-21 21:02:00 (EST-5)
Location: WESTMONT
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A few trees were blown down in a Cherry Hill neighborhood.

Thunderstorm Wind in BURLINGTON, NEW JERSEY
From 17-JUL-21 21:27:00 to 17-JUL-21 21:27:00 (EST-5)
Location: MARLTON
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: State Official

Several trees were downed in Evesham Twp. Time estimated from radar.

Thunderstorm Wind in HUNTERDON, NEW JERSEY
From 17-JUL-21 18:35:00 to 17-JUL-21 18:35:00 (EST-5)
Location: CLINTON
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

A tree was downed on I-78. Time estimated from radar.

Tornado in BURLINGTON, NEW JERSEY
From 17-JUL-21 21:25:00 to 17-JUL-21 21:36:00 (EST-5)
Location: JOBSTOWN ARPT
Tornado F-scale: EF1
Crop damage: 0.00K
Reported by: NWS Storm Survey

A narrow, discontinuous, path of tree damage began just east of
the Route 206 and Columbus-Jobstown Road intersection. This is 1
mile northeast of the Burlington County Fairgrounds. Significant
tree damage was observed in a neighborhood north of Columbus-
Jobstown Road. From there, several large limbs were snapped off on
Island Road. One tree was uprooted and one was snapped on
Juliustown-Georgetown Road. An additional tree was snapped on NJ
Route 68. Numerous large limbs were blown on powerlines on Monmouth
Road near Tilghmans Corner. Scattered tree damage was observed in
Jacobstown in North Hanover Township. The tornado dissipated
before the Ocean County line.