EF1 tornado, Edison to Buckmanville, Pennsylvania, September 1, 2021

1. EF065 to 85 mph

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. EF186 to 110 mphthis tornado

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. EF2111 to 135 mph

   Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

4. EF3136 to 165 mph

   Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

5. EF4166 to 200 mph

   Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

6. EF5over 200 mph

   Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

7. Unrated

   The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

Rating

EF1

Date

September 1, 2021

Touchdown

5:59 PM EDT (21:59 UTC)

Lifted

6:06 PM EDT (22:06 UTC)

On the ground

7 minutes

Path length

4.3 miles (6.9 km)

Path width

300 yards (274 m)

Deaths

0

Injuries

0

County

Bucks County

Touchdown point

40.270, -75.110

Lift-off point

40.327, -75.077

Record number

2109011559-01

47 damage points were recorded along this path by NWS PHI, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF2. The highest wind the damage implies is 132 mph.

• Relatively small trees snapped.
• Roof damage at veterinary hospital.
• Decent size limbs with at least one small uproot
• May be a mix of flooding damage and wind damage in this area.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

The remnants of Hurricane Ida impacted the mid-Atlantic on September 1, 2021. As it moved northward, Ida began transitioning to a strong mid-latitude cyclone with pronounced frontal features, but with continued tropical moisture. On a regional level, the remnants of Ida became one of the most severe natural disasters in US history, due to a combination of several tornadoes, some of them strong, as well as catastrophic flooding over a large and densely populated area. The severe weather threat unfolded as the system's developing warm front lifted northward from the Delmarva region into Pennsylvania and New Jersey. South of the warm front, partial clearing and moderate to strong instability developed. Meanwhile, very strong shear and forcing, along with tropical moisture, were present within the warm sector. The result was widespread convection in the form of both supercell and quasi-linear thunderstorms. A number of storms became severe across the region, producing several tornadoes and other instances of wind damage. This continued an exceptionally active stretch of high end severe weather in the region, coming barely a month after the tornado outbreak of July 29.

The storm which produced a strong tornado in Montgomery County, |PA, cycled and produced another tornado in Bucks County, PA. |Damage began near in the area of Neshaminy Creek between Valley Rd|and Pebble Hill Rd in Doylestown. The tornado tracked north- |northeast from there, producing a consistent path of damage. |Damage was mainly confined to trees and was fairly extensive at |times, with much of the path length being heavily wooded. Numerous|hardwood and softwood trees were snapped and uprooted along the |path. Damage was strongly suggestive of tornadic winds, and a |tornado debris signature was also evident on radar. The heaviest |damage occurred near and along a stretch of Edison- Furlong Rd. |Extensive tree damage occurred along that road and a number of its|cross streets. Several utility poles were snapped in this area. |Tree damage along nearby Swamp Rd was also significant. The |tornado continued but began to lose intensity as it approached |Route 202, with sporadic tree damage observed on Mill Rd. Gradual |weakening continued and the tornado appeared to lift entirely in |the area of Burnt House Hill Rd. The extent of tree damage |suggested maximum winds of around 100 mph. No injuries were |reported as a result of this tornado.

A tornado embedded within a squall line developed several miles |southeast of the storm which produced a tornado in Buckingham |Township. Tornadic damage was first observed in the vicinity of |Stoneybrook Rd at Eagle Rd, near Jericho Creek. The tornado |tracked northeastward from there. It passed over the Jericho |National Golf Club, and sporadic tree damage mainly consisting of |uproots and large limbs snapped was observed in a path throughout |the golf course. It then moved over the adjacent Brownsburg Park, |where additional tree damage was observed and several soccer goals|were observed flipped in various directions. The tornado then |began to approach the Delaware River. Some minor tree damage was |observed along River Rd. However, the tornado appeared to lift |just slightly before reaching the Delaware River, with no apparent|damage on Pebbletown Rd just prior to the river. Throughout its |path, the tree damage produced by this tornado was fairly |sporadic, and it may have been discontinuous. Noticeable wind |damage was also observed for at least a mile east of the tornado |track, especially near its endpoint close to the Delaware River. |This is believed to be straight line wind damage, which is |corroborated by radar data, occurring around the rear flank |downdraft region of the tornadic circulation. However, the exact |length and width of the tornadic circulation is somewhat uncertain|due to the surrounding areas of straight line wind damage.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

25 minutes of warning. NWS PHI issued a tornado warning for this county at 21:34 UTC, 25 minutes before the tornado touched down, in force until 22:00 UTC.

The county was under a tornado watch, issued at 16:41 UTC and running to 01:54 UTC.

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The Storm Prediction Center had this point in a Enhanced Risk, with a 0.10 chance of a tornado within 25 miles. The outlook in force was issued at 19:46 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

The Philadelphia radar (KDIX), 70 km away, was scanning. The volume nearest the touchdown began at 22:00 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

Local storm reports within 60 km of the path, in the three hours either side.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

The live radar over the trackEvery 2021 tornado in PennsylvaniaEvery tornado in Pennsylvania since 1950Warnings in force in Pennsylvania nowThe forecast where you are

10 more were confirmed in the United States that day.

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.