Tornadoes · United States · Pennsylvania · 2026
EF0 tornado, Chester County, Pennsylvania, August 20, 2026
This EF0 tornado ran 0.2 miles across Chester County on August 20, 2026, touching down at 5:40 PM EDT and reaching 30 yards wide. It killed nobody.
Preliminary. This is NWS PHI's damage survey, filed in the Damage Assessment Toolkit. The rating, the path and the casualties are the survey's and can change while it is revised. The Storm Prediction Center compiles the official record of 2026 from these surveys and publishes it in the spring of 2027; this page moves to that tornado's permanent address when it does.
The rating scale
Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.
EF065 to 85 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
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.
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.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
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.
The survey
- Rating, as surveyed
- EF0, preliminary
- Date
- August 20, 2026
- Touchdown
- 5:40 PM EDT (21:40 UTC)
- Path length
- 0.2 miles (0.3 km)
- Path width
- 30 yards (27 m)
- Deaths
- 0
- Injuries
- 0
- County
- Chester County
- Touchdown point
- 40.018, -75.675
- Lift-off point
- 40.017, -75.672
- Highest wind the damage implies
- 70 mph
- Surveyed by
- NWS PHI
- Survey last edited
- August 24, 2026
- Record number
- None yet. SPC numbers 2026 in the spring of 2027.
The damage survey
4 damage points were recorded along this path by NWS PHI, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 70 mph.
Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.
The air that afternoon
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.
Washington/Dulle, VA (KIAD), 12:00Z
9.7 hours before the tornado, 190 km from the path. August 20, 2026.
- Mixed-layer CAPE
- 97 J/kg
- Mixed-layer CIN
- -72 J/kg
- Surface CAPE
- 178 J/kg
- Mixed-layer LCL
- 1192 m above ground
- 0-6 km bulk shear
- 47 kt
- 0-1 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- 115 m²/s²
- 0-3 km storm-relative helicity
- 230 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -0.0
- 0-3 km lapse rate
- 5.5 K/km
The surface observations
West Chester (OQN), 9 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 00:00 UTC |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The Philadelphia radar (KDIX), 108 km away, was scanning. The volume nearest the touchdown began at 21:38 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.
This ground now
The live radar over the trackEvery 2026 tornado in PennsylvaniaEvery tornado in Pennsylvania since 1950Warnings in force in Pennsylvania nowThe forecast where you are
The other tornadoes of August 20, 2026
10 more have been surveyed in the United States that day, so far.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| August 20 | 4:09 PM EDT | EF1 | Kent, DE | 3.2 | 100 | |||
| August 20 | 4:24 PM EDT | EF2 | York, PA | 1.1 | 100 | 1 | ||
| August 20 | 4:30 PM EDT | EF1 | Lancaster, PA | 3.0 | 100 | |||
| August 20 | 4:37 PM EDT | EF0 | Lancaster, PA | 0.3 | 75 | |||
| August 20 | 4:38 PM EDT | EF0 | Lancaster, PA | 0.5 | 125 | |||
| August 20 | 3:51 PM CDT | EF0 | Baldwin, AL | 2.9 | 150 | |||
| August 20 | 5:41 PM EDT | EF1 | Queen Anne's, MD | 0.5 | 70 | |||
| August 20 | 5:54 PM EDT | EF1 | Kent, DE | 1.3 | 60 | |||
| August 20 | 6:02 PM EDT | EF0 | Kent, DE | 0.6 | 100 | |||
| August 20 | 7:27 PM CDT | EF0 | Hutchinson, SD | 0.1 | 25 |
What this means
Ratings are the survey's, read off the damage rather than measured; the rating scale is above. A survey can be revised, so the rating, the path and the casualties can all still change.
Sources
NWS Damage Assessment Toolkit, the record the survey teams file from the damage, and NOAA Storm Prediction Center storm reports. Neither is the official database for 2026, which SPC publishes in the spring of 2027.