Tornadoes · United States · Virginia · 2020

EF0 tornado, Trinity, Virginia, August 1, 2020

This EF0 tornado ran 1.2 miles across Botetourt County on August 1, 2020, touching down at 6:25 PM EDT and reaching 75 yards wide. It killed nobody, and did $4,000 of property damage.

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.

  1. EF065 to 85 mphthis tornado

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

  2. EF186 to 110 mph

    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.

The record

Rating
EF0
Date
August 1, 2020
Touchdown
6:25 PM EDT (22:25 UTC)
Lifted
6:31 PM EDT (22:31 UTC)
On the ground
6 minutes
Path length
1.2 miles (1.9 km)
Path width
75 yards (69 m)
Deaths
0
Injuries
0
Property damage
$4,000
County
Botetourt County
Touchdown point
37.474, -79.967
Lift-off point
37.488, -79.957
Record number
2008011625-01

The damage survey

9 damage points were recorded along this path by NWS RNK, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 85 mph.

  • Location estimated from Drone footage.

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

What the Weather Service recorded

A weakly sheared, high instability day in August resulted in isolated storms that were able to produce damaging winds and an isolated tornado.

An isolated storm produced an EF0 tornado, resulting in a discontinuous path of damage with uprooted trees and small trees snapped aloft.

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

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

Issued (UTC)ExpiredProductOffice
22:35 UTC23:30 UTCSevere Thunderstorm WarningRNK
22:46 UTC23:30 UTCTornado WarningRNK
23:22 UTC00:00 UTCTornado WarningRNK

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 forecast that day

The Storm Prediction Center had this point in a Marginal Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 20:00 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 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.

Roanoke, VA (KRNK), 12:00Z

10.4 hours before the tornado, 51 km from the path. August 1, 2020.

Skew-T log-pSkew-T log-p diagram, Roanoke, VA at 12:00Z on 2020-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 4 joules per kilogram, CIN -134, lifted condensation level 747 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Roanoke, VA at 12:00Z on 2020-08-01The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 67 square meters per square second, 0 to 6 km bulk shear 24 knots.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
4 J/kg
Mixed-layer CIN
-134 J/kg
Surface CAPE
439 J/kg
Mixed-layer LCL
747 m above ground
0-6 km bulk shear
24 kt
0-1 km bulk shear
16 kt
0-1 km storm-relative helicity
67 m²/s²
0-3 km storm-relative helicity
136 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
4.2 K/km

Open this sounding in Storm Lab

Roanoke, VA (KRNK), 00:00Z

1.6 hours after it, 51 km from the path. August 2, 2020.

Skew-T log-pSkew-T log-p diagram, Roanoke, VA at 00:00Z on 2020-08-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 784 joules per kilogram, CIN -4, lifted condensation level 1219 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Roanoke, VA at 00:00Z on 2020-08-02The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 95 square meters per square second, 0 to 6 km bulk shear 33 knots.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
784 J/kg
Mixed-layer CIN
-4 J/kg
Surface CAPE
1753 J/kg
Mixed-layer LCL
1219 m above ground
0-6 km bulk shear
33 kt
0-1 km bulk shear
19 kt
0-1 km storm-relative helicity
95 m²/s²
0-3 km storm-relative helicity
119 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.9
0-3 km lapse rate
6.9 K/km

Open this sounding in Storm Lab

The surface observations

Roanoke Muni (ROA), 18 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
20:25 UTC140° 11 kt1013.2
20:30 UTC130° 10 kt1013.2
20:35 UTC140° 10 kt1013.2
20:40 UTC130° 9 kt1013.2
20:45 UTC120° 9 kt1013.2
20:50 UTC130° 9 kt1013.2
20:54 UTC8674140° 11 kt1012.9
20:55 UTC140° 11 kt1012.9
21:00 UTC130° 7 kt1012.9
21:05 UTC110° 10 kt1012.9
21:10 UTC120° 10 kt1012.9
21:15 UTC120° 10 kt1012.9
21:20 UTC120° 11 kt1012.9
21:25 UTC120° 10 kt1012.9
21:30 UTC130° 11 kt1013.2
21:35 UTC130° 11 kt1013.2
21:40 UTC120° 13 kt1013.2
21:45 UTC120° 11 kt1013.2
21:50 UTC130° 11 kt1013.2
21:54 UTC8574140° 12 kt1013.2
21:55 UTC130° 11 kt1013.2
22:00 UTC140° 11 kt1013.2
22:05 UTC130° 15 kt1013.5
22:10 UTC120° 13 kt1013.2
22:15 UTC150° 11 kt1013.2
22:20 UTC140° 14 kt1013.2
22:25 UTC140° 14 kt1012.9
22:30 UTC150° 11 kt1013.2
22:35 UTC150° 11 kt1013.2
22:40 UTC160° 11 kt1013.2
22:45 UTC 13 kt1013.2
22:50 UTC160° 11 kt1013.5
22:54 UTC8673170° 11 kt1013.5
22:55 UTC180° 11 kt1013.5
23:00 UTC170° 10 kt1013.5
23:05 UTC180° 10 kt1013.9
23:10 UTC180° 10 kt1013.9
23:15 UTC170° 9 kt1013.9
23:20 UTC180° 8 kt1013.9
23:25 UTC170° 8 kt1013.9
23:30 UTC170° 11 kt1013.5
23:35 UTC170° 8 kt1013.5
23:40 UTC180° 9 kt1013.5
23:45 UTC170° 8 kt1013.5
23:50 UTC180° 5 kt1013.5
23:54 UTC8572180° 6 kt1013.5
23:55 UTC170° 5 kt1013.5
00:00 UTC190° 8 kt1013.5
00:05 UTC170° 7 kt1013.5
00:10 UTC180° 5 kt1013.5
00:15 UTC190° 5 kt1013.5
00:20 UTC200° 4 kt1013.9

From the Iowa Environmental Mesonet's archive of airport observations.

The radar

The Roanoke radar (KFCX), 58 km away, was scanning. The volume nearest the touchdown began at 22:24 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.

What was reported nearby

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

Time (UTC)ReportWhereCountyRemark
22:35 UTCTORNADO3 Wsw FincastleBotetourt, VAMULTIPLE VIDEOS AND PHOTOS INDICATING A POSSIBLE TORNADO IN THE VICINITY OF BLACKSBURG ROAD BETWEEN HAYMAKERTOWN AND FINCASTLE IN BOTETOURT COUNTY.
23:26 UTCTSTM WND DMG1 W Eagle RockBotetourt, VAA TREE FELL ON TO A POWER LINE AT THE INTERSECTION OF FULL HOUSE ROAD AND GARRON ROAD NEAR EAGLE ROCK. TIME ESTIMATED BY RADAR.

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

This ground now

The live radar over the trackEvery 2020 tornado in VirginiaEvery tornado in Virginia since 1950Warnings in force in Virginia nowThe forecast where you are

The other tornadoes of August 1, 2020

1 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 14:42 PM CDTEF0Nueces, TX0.020

What this means

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.

Sources

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