EF1 tornado, Crabapple, Pennsylvania, July 29, 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

July 29, 2021

Touchdown

6:00 PM EDT (22:00 UTC)

Lifted

6:05 PM EDT (22:05 UTC)

On the ground

5 minutes

Path length

2.8 miles (4.5 km)

Path width

200 yards (183 m)

Deaths

0

Injuries

0

Property damage

$100,000

County

Greene County

Touchdown point

39.962, -80.516

Lift-off point

39.932, -80.480

Record number

2107291600-01

A shortwave passage during the morning of July 29th spread mainly non-severe showers and thunderstorms across the region during the morning and midday hours. However, a discrete cell along the back edge of the morning activity was able to develop an EF1 tornado along the Fayette-Westmoreland County border. This was a preview of what was to follow. ||In the wake of this morning activity, instability was able to build as partial clearing occurred. Additional thunderstorms were able to develop in association with a prefrontal trough. These storms were able to take advantage of deep shear, especially in the lower levels. A cross-boundary component to this shear allowed discrete supercells to form during the mid and late afternoon hours. Storm motions were favorable for the ingestion of streamwise vorticity, allowing for rotating storms, and the development of additional tornadoes in southwest Pennsylvania and eastern Ohio. Three additional tornadoes occurred in southwest Pennsylvania, causing generally tree and light structural damage. Thankfully, no injuries were reported. A few other damaging wind reports were received as well.

An EF-1 tornado damaged a rural portion of extreme western Greene|County during the early evening of July 29th. The affected area |was just south of State Gamelands No. 302, in a region of |rough terrain characterized by dense wooded areas, mixed with open|farm land and gas well production infrastructure.||Damage from this tornado was confined to mainly hardwood trees in|the wooded areas. The tornado snapped a number of small trees, |uprooted several larger ones, and downed numerous large branches |over the course of its nearly 3 mile track. The initial damage |occurred at the bridge crossing Enlow Fork on the Pennsylvania |side of the MarkWest Majorsville Station. As the storm tracked to |the southeast, it reached peak intensity along Day Road, where |considerable tree damage was noted from an adjacent hill, |extending down into a deep ravine. Several large trees were |uprooted along with many smaller ones snapped. The tornado's maximum wind speed of 105 MPH was estimated in this area. Sporadic tree damage was noted as the tornado moved southeast and crossed Fry Hill Road, Scott Hill Road, and finally along the southern spur of |Day Road once again (just southeast of the Veterans Road fork).||This is the eighth documented tornado to impact Greene County |since 1950, and is the first since October 2nd 2018. In addition, |this marks the 8th tornado confirmed within the NWS Pittsburgh |forecast area from the July 29th outbreak, the most in a single |event since May 1st 2017, when seven tornadoes were recorded|over northwest Pennsylvania.

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

12 minutes of warning. NWS PBZ issued a tornado warning for this county at 21:48 UTC, 12 minutes before the tornado touched down, in force until 22:15 UTC.

The county was under a severe thunderstorm watch, issued at 19:16 UTC and running to 00:39 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 Slight Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:53 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 Pittsburgh radar (KPBZ), 69 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

36 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.