A strong shortwave trough moved east-southeastward out of the Great Lakes region on July 29. An associated, strengthening surface low also tracked out of the Great Lakes and into upstate New York. A warm front associated with this low moved through most of New Jersey and eastern Pennsylvania during the late morning and early afternoon hours. This front, combined with the remains of widespread convection to the west from the previous overnight and morning hours, brought significant cloud cover to the eastern mid-Atlantic for much of the day on the 29th. This was mainly in the form of mid and high level cloud cover, however, and temperatures still warmed to near seasonal levels behind the warm front, allowing moderate to strong instability to build. Meanwhile, the robust surface and upper level disturbances approaching the region brought both strong forcing and unseasonably strong wind shear. By mid-afternoon, an unusually favorable convective environment existed over eastern Pennsylvania and New Jersey.
The result of this environment was a rare tornado outbreak across the area. Initially, during the mid-afternoon hours, mixed convective modes over east-central Pennsylvania produced a couple instances of damaging wind and brief tornadoes as storms attempted to overcome cloud cover and some light stratiform rain in the area. With time, as storms moved into better instability and a less contaminated environment over far eastern Pennsylvania and New Jersey, they took on more supercellular structures. Multiple cyclic supercells would go on to produce several tornadoes, three of them strong (EF2+) over eastern Pennsylvania and New Jersey. Convection persisted past the sunset hour with little to no loss in intensity due to the strong forcing. The only thing that put an end to the outbreak was the coastline, as storms moved offshore towards 9 to 10PM local time. Even offshore, one supercell continued to exhibit strong rotation and likely produced a strong waterspout for tens of miles over the Atlantic.
Fortunately, and miraculously, no serious injuries or loss of life occurred as a result of this outbreak. With the passage of a cold front late on the evening of the 29th, cooler, drier, and much less active weather would grace the region for several days as clean-up efforts began.

Tornado in LEHIGH, PENNSYLVANIA
From 29-JUL-21 15:05:00 to 29-JUL-21 15:09:00 (EST-5)
Location: STINES CORNER
Tornado F-scale: EF1
Property damage: 0.00K
Reported by: NWS Storm Survey

The tornado which began in western Albany Twp, Berks County, continued into Lehigh County. It tracked between between Kunkels Mill Rd and Red Rd near the far
southern tip of Lynn Twp. Mostly minor crop and
tree damage was observed in this area, but with a continued clear
convergent pattern. A resident on Red Rd filmed the tornado as it
passed to his south. The tornado passed through an open field before
crossing Rhoads Rd, where tree and minor roofing damage were
sustained. East of Rhoads Rd, a number of trees were snapped and
uprooted as the tornado approached New Smithville Rd. The tornado
crossed Golden Key Rd, uprooting a few more trees, before
dissipating in a field prior to reaching Loch Valley Rd in
Weisenberg Twp. The extent of tree damage both near the start of the
path in Berks County and in the New Smithville Rd area merited an EF1
rating.

Tornado in BERKS, PENNSYLVANIA
From 29-JUL-21 15:04:00 to 29-JUL-21 15:05:00 (EST-5)
Location: STONY RUN
Tornado F-scale: EF1
Property damage: 0.00K
Reported by: NWS Storm Survey

A tornado touched down near Turkey Rd in Kempton, Albany Twp, Berks
County, PA, just west of the border with Lehigh County. About 15
trees were uprooted in the area of Turkey Rd with a convergent
damage pattern noted in multiple nearby corn fields. The tornado then continued eastward into Lehigh County after only about one minute in Berks County.

Tornado in LEHIGH, PENNSYLVANIA
From 29-JUL-21 15:25:00 to 29-JUL-21 15:29:00 (EST-5)
Location: EMERALD
Tornado F-scale: EF1
Reported by: NWS Storm Survey

This tornado initially caused considerable tree damage on
Welshtown Road and Skeet Club Lane including mutliple uprooted
hardwood trees. It continued on the grounds of Northern Lehigh
High School in Slatington. Several trees were snapped or uprooted
at the atletic fields of the high school, with most of the
snapping occurring high up in the trees. A wooden dugout on the
school's baseball field lost its roof, and some unanchored metal
bleachers were tossed. Damage was mostly blown in a similar west
to east direction, but there was some evidence of convergence
especially in tree damage in the area. In a neighborhood east of
the high school, a tree was snapped about one third of the way up
the trunk. At the Slatington Airport, an airplane hangar door was
blown out and there was tree damage on the airport property.
Damage became more unidirectional near the airport as the
circulation likely gusted out. Little if any damage occurred east
of the airport property, and that is where the tornado path is
estimated to have ended.

Funnel Cloud in NORTHAMPTON, PENNSYLVANIA
From 29-JUL-21 15:58:00 to 29-JUL-21 15:58:00 (EST-5)
Location: FARMINGTON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A photo was submitted via social media of a funnel cloud just north of Center Valley.

Thunderstorm Wind in LEHIGH, PENNSYLVANIA
From 29-JUL-21 15:08:00 to 29-JUL-21 15:08:00 (EST-5)
Location: LYNNPORT
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Trees and wires were downed. Time estimated by radar.

Thunderstorm Wind in BUCKS, PENNSYLVANIA
From 29-JUL-21 16:11:00 to 29-JUL-21 16:11:00 (EST-5)
Location: QUAKERTOWN
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Several trees were downed in Quakertown. This storm would go on to produce multiple tornadoes. Time estimated from radar.

Thunderstorm Wind in LEHIGH, PENNSYLVANIA
From 29-JUL-21 15:05:00 to 29-JUL-21 15:05:00 (EST-5)
Location: STINES CORNER
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Utility poles were reported down in the area.

Thunderstorm Wind in BUCKS, PENNSYLVANIA
From 29-JUL-21 16:50:00 to 29-JUL-21 16:50:00 (EST-5)
Location: MECHANICSVILLE
Magnitude: 60.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Widespread tree damage and minor damage to some structures was reported in Buckingham Twp.

Thunderstorm Wind in BUCKS, PENNSYLVANIA
From 29-JUL-21 16:30:00 to 29-JUL-21 16:30:00 (EST-5)
Location: OTTSVILLE
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Trees or limbs blocked Fretz Valley Rd, Geigel Hill Rd, and Creamery Rd. Time estimated from radar.

Thunderstorm Wind in LEHIGH, PENNSYLVANIA
From 29-JUL-21 15:14:00 to 29-JUL-21 15:14:00 (EST-5)
Location: HYNEMANSVILLE
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Trees and wires were downed on Route 863, and the road was closed. Time estimated from radar.

Tornado in BUCKS, PENNSYLVANIA
From 29-JUL-21 16:40:00 to 29-JUL-21 16:45:00 (EST-5)
Location: WISMER
Tornado F-scale: EF1
Reported by: NWS Storm Survey

Tree damage began in the area of Bradshaw Rd in Plumstead Twp in
Bucks County, where a few sizable limbs were downed and a couple
of larger but weakened trees were snapped. The tornado then
entered a cornfield near the intersection of Ferry Rd and Point
Pleasant Pike. Some degree of convergence was noted in a narrow
path of downed corn, though it was not overly strong. In addition,
some trees adjacent to and southeast of the cornfield were also
damaged. The damage became more substantial with a clearer
rotation signature observed in the area of Ridgeview Dr, where a
number of trees were snapped, favoring higher elevation areas
along a ridge line. The snapping and shearing of trees in that
area and the nature of the debris field strongly indicated
tornadic damage, with the magnitude of damage meriting an EF1
rating. The tornado continued southeastward through Carversville
Rd and to the area of Long Ln in Buckingham Twp. Several
residences along and near Long Ln sustained tree damage. The
tornado impacted Maximuck's Farm Market on Long Ln, where
greenhouses sustained roof damage and some uplift of their frames.
Some convergence was also noted in crop fields on the property.
Just southeast of the greenhouses, a barn on the property was
heavily damaged with a partial collapse of its walls. However,
just beyond the barn, a large stretch of cornfields and a tree
line beyond the cornfields were left untouched, indicating the
tornado lifted near the damaged barn.

Tornado in BUCKS, PENNSYLVANIA
From 29-JUL-21 16:59:00 to 29-JUL-21 17:01:00 (EST-5)
Location: NEW HOPE
Tornado F-scale: EF2
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

The supercell storm which produced a tornado in Plumstead Twp in Bucks County
cycled and produced another tornado beginning in New Hope in
Bucks County, Pennsylvania. Tree damage began near River Rd just
west of the Delaware River, with a portion of River Rd closed and
impassable due to downed trees. The tornado then began to cross the Delaware River enroute to Mercer County, New Jersey.

Tornado in PHILADELPHIA, PENNSYLVANIA
From 29-JUL-21 18:04:00 to 29-JUL-21 18:06:00 (EST-5)
Location: BYBERRY
Tornado F-scale: EF3
Crop damage: 0.00K
Reported by: NWS Storm Survey

An EF3 tornado better known for its impacts it Bucks County, PA began briefly in Philadelphia County, PA. The tornado touched down near Southampton Road, Kelvin Avenue, and Trevose Road where it uprooted and blew down large limbs from a
few softwood and hardwood trees. The tornado then moved into Bucks County, with trees uprooted at the county line.

Tornado in BUCKS, PENNSYLVANIA
From 29-JUL-21 18:06:00 to 29-JUL-21 18:12:00 (EST-5)
Location: BELMONT HILLS
Tornado F-scale: EF3
Crop damage: 0.00K
Reported by: NWS Storm Survey

The tornado which began in Philadelphia County crossed into Bucks County, where it would produce the majority of its impacts. After crossing the county line, the tornado continued between Trevose Road and Peyton Street
where additional tree damage occurred before crossing Lukens
Street. The tornado then very briefly crossed back into
Philadelphia County at the northern tip of Poquessing Valley Park
where a few trees were uprooted. The tornado then crossed back
into Trevose in Bucks County where it caused some minor cosmetic
damage to some homes in the Beechwood Estates neighborhood and
blew down several sections of vinyl fencing. Several small trees
were also snapped or uprooted in and just south and east of the
residential neighborhood.
As the tornado approached Somerton Road, it began intensifying
and widening substantially as it moved into the Metropolitan
Industrial Center. Numerous softwood and hardwood trees were
snapped or uprooted in the SUEZ Water Company property southwest
of and along Somerton Road. Five wooden power poles were snapped
near the ground along Somerton Road as well at the northern end of
the SUEZ property. All seven warehouse buildings in the
industrial complex northeast of Somerton Road sustained at least
minor damage, with the most significant occurring to the Northtec
building. Numerous roof mounted HVAC units were shifted or blown
off of a few of the buildings in the industrial complex. Open bay
doors in the western- most building caused a non-load bearing
interior wall to collapse. A sedan was lifted and flipped over in
the Northtec parking lot and a steel flag pole bearing a flag
flattened completely to the ground. The Northtec building
sustained substantial structural damage where large sections of
roofing material were removed. Additionally, numerous exterior
paneling was blown off, garage bay doors were blown out, a few
windows were blown out, and at least two large HVAC units were
blown off of the building. Numerous softwood and hardwood trees
were uprooted or snapped in the industrial complex and immediately
adjacent areas.
A cellphone tower adjacent to the industrial complex had all of
the antennas blown off, but the tower itself did not collapse.
Southeast of the industrial complex, minor cosmetic damage
occurred to some homes along Carter Road in a residential
neighborhood. Tree damage associated with the tornado occurred
along Carter Road and Sussex Road north of Buckfield Terrace. This
was the area where the tornado circulation reached its widest
extent of around three tenths of a mile. As the tornado neared and
crossed the Pennsylvania Turnpike (I- 276), an overhead roadway
information sign was blown off and a portion of it landed
downstream nearly a half mile away. Just north of the turnpike,
minor cosmetic damage occurred to a hotel building where a tree
was also uprooted in the parking lot. A large billboard was blown
over just north of the turnpike and south of Street Road. A small
utility building nearby had its roof blown off. The northern- most
extent of the damage occurred on the Toscana 52 restaurant
property where the tornado blew down some chain link fencing and
uprooted a few small trees in the parking lot.
The tornado continued east-northeastward across Street Road
toward the Faulkner car dealership complex where it began
intensifying and somewhat narrowing its path of damage. The four
dealership showrooms sustained significant damage where most
windows were blown out and at least some roofing material was
blown off. The most significant damage occurred to the Buick/GMC
showroom where most of the roofing material was blown off, all
windows and doors were blown out, and exterior walls exhibited
fracturing due to stress from the wind. Roof HVAC units of this
building were tossed into the parking lot behind the building. All
of the dealership signs near the main road were destroyed. Scores
of new and used vehicles sustained significant damage from flying
debris or from being pushed or tossed trough the air.
The tornado continued toward the dealership's main service garage
where the most significant damage occurred. The southwestern
portion of the building was destroyed with most exterior walls
collapsing completely and all roofing material blown off. Interior
walls mostly remained standing. Roof HVAC units were tossed off
of the building with one unit landing nearly 200 yards downstream
of the building. Damage sustained to the building decreased
somewhat toward the eastern end of it where portions of the
exterior walls were damaged and almost all garage bay doors were
blown out. The wind rushing through the garage area carried
debris, car parts, and tools well away from the structure
downstream. Some vehicles near the main garage building were
completely destroyed from large pieces of flying debris or from
being tossed and dropped back onto the ground. A small pickup
truck was crushed from a collapsed exterior wall. Five people
reportedly sustained minor injuries at the dealership complex.
The tornado continued east-northeast toward the Weisser Homes
mobile home park and into an area of trees which sustained
significant damage. Most tree canopies and limbs were completely
stripped from the still standing or snapped trunks of hardwood
trees in this area. A large storage container filled with car
parts from the service garage parking lot upstream was lofted into
the air and dropped into this area of trees. An uninhabited
mobile home model was lifted and completely destroyed at the
mobile home park. Another double-wide mobile home had a large
portion of its roof blown off. Several other mobile home sustained
varying degrees of damage as well. A large amount of various
debris from the dealership complex landed in this mobile home
park. Numerous softwood and hardwood trees near and just
downstream of this area were snapped or uprooted along Old Lincoln
Highway.
At this stage, the tornado damage path narrowed considerably and
intensity weakened significantly as it crossed Old Lincoln Highway
and moved toward the Lowe's and Walmart shopping centers on Route
1. The tornado passed over these shopping centers, but no
structural damage was noted to these structures. Numerous small
trees were snapped and uprooted in the large parking lot area and
line of trees just north of the Bensalem turnpike interchange.
Some exit ramp signs were blown down in the interchange area.
The tornado damage became somewhat discontinuous as it continued
east-southeast into Bensalem across Route 1 and toward a
residential neighborhood. Several homes in the neighborhood
sustained loss of some roofing material and other cosmetic damage
in addition to some tree damage. The tornado continued across
Rockhill Road and along Richlieu Road toward the Christian Life
Center where several trees were snapped or uprooted. The church's
steeple had some paneling blown off, but the steeple itself was
not damaged otherwise. The tornado continued weakening as it
crossed Galloway Road then dissipated in the Bensalem Township
Community Park where some minor tree damage occurred.
No known serious injuries or fatalities occurred from this
tornado.

Tornado in PHILADELPHIA, PENNSYLVANIA
From 29-JUL-21 18:07:00 to 29-JUL-21 18:08:00 (EST-5)
Location: BUSTLETON
Tornado F-scale: EF0
Crop damage: 0.00K
Reported by: NWS Storm Survey

A brief tornado occurred in the Bustleton section of Northeast
Philadelphia. Damage was first observed near Grant Ave at the
Grant Gardens apartment complex, where some minor loss of roofing
material was noted and debris was tossed in a chaotic manner
consistent with tornadic winds. The tornado moved east-southeast
across Roosevelt Blvd. Continued minor structural damage was noted
along a narrow path, mainly consisting of sporadic losses of
siding and insulation. Minor tree damage was also noted. One
building also had ceiling tiles pulled downward with insulation
removed in a car park area, a strong indicator of tornadic
pressure gradient forces. Near Blue Glass Rd, a couple of slightly
larger trees had their trunks snapped, and winds of around 80 mph
likely occurred in that area. The damage path ended near there,
however, after a track length of only around half a mile. Radar
data indicates this was an anticyclonic tornado.