Tornadoes · United States · Tennessee · 2020

EF0 tornado, Bending Chestnut, Tennessee, September 1, 2020

This EF0 tornado ran 2.8 miles across Williamson County on September 1, 2020, touching down at 4:28 PM CDT and reaching 25 yards wide. It killed nobody, and did $5,000 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
September 1, 2020
Touchdown
4:28 PM CDT (21:28 UTC)
Lifted
4:35 PM CDT (21:35 UTC)
On the ground
7 minutes
Path length
2.8 miles (4.5 km)
Path width
25 yards (23 m)
Deaths
0
Injuries
0
Property damage
$5,000
County
Williamson County
Touchdown point
35.862, -87.137
Lift-off point
35.864, -87.088
Record number
2009011528-01

The damage survey

11 damage points were recorded along this path by NWS OHX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 75 mph.

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 line of severe thunderstorms moved through Middle Tennessee on the afternoon of September 1st. A weak, brief tornado developed in Williamson County with wind damage and flash flooding reports across Middle TN.

Drone video footage provided by NashSevereWx, reports from emergency management, and radar data all indicated a brief EF-0 tornado touched down in far southwestern Williamson County along Green Chapel Road blowing down several trees. The tornado continued east and caused more minor tree damage on North Lick Creek Road and Bending Chestnut Road at I-840 before becoming outflow dominant straightline winds.

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

The warnings

0 minutes of warning. NWS OHX issued a tornado warning for this county at 21:28 UTC, 0 minutes before the tornado touched down, in force until 22:00 UTC.

Issued (UTC)ExpiredProductOffice
21:22 UTC22:00 UTCSevere Thunderstorm WarningOHX
21:28 UTC22:00 UTCTornado WarningOHX
21:57 UTC22:30 UTCSevere Thunderstorm WarningOHX
22:16 UTC01:15 UTCFlood AdvisoryOHX
22:27 UTC02:45 UTCFlash Flood WarningOHX
22:53 UTC03:15 UTCFlash Flood WarningOHX

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. The outlook in force was issued at 19:40 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.

Nashville Metro, TN (KBNA), 12:00Z

9.5 hours before the tornado, 55 km from the path. September 1, 2020.

Skew-T log-pSkew-T log-p diagram, Nashville Metro, TN at 12:00Z on 2020-09-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 69 joules per kilogram, CIN -31, lifted condensation level 570 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, Nashville Metro, TN at 12:00Z on 2020-09-01The 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 42 square meters per square second, 0 to 6 km bulk shear 18 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
69 J/kg
Mixed-layer CIN
-31 J/kg
Surface CAPE
122 J/kg
Mixed-layer LCL
570 m above ground
0-6 km bulk shear
18 kt
0-1 km bulk shear
12 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
62 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.5 K/km

Open this sounding in Storm Lab

Nashville Metro, TN (KBNA), 00:00Z

2.5 hours after it, 55 km from the path. September 2, 2020.

Skew-T log-pSkew-T log-p diagram, Nashville Metro, TN at 00:00Z on 2020-09-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 428 joules per kilogram, CIN -80, lifted condensation level 889 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, Nashville Metro, TN at 00:00Z on 2020-09-02The 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 48 square meters per square second, 0 to 6 km bulk shear 38 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
428 J/kg
Mixed-layer CIN
-80 J/kg
Surface CAPE
189 J/kg
Mixed-layer LCL
889 m above ground
0-6 km bulk shear
38 kt
0-1 km bulk shear
11 kt
0-1 km storm-relative helicity
48 m²/s²
0-3 km storm-relative helicity
92 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.4
0-3 km lapse rate
4.4 K/km

Open this sounding in Storm Lab

The radar

The Nashville radar (KOHX), 65 km away, was scanning. The volume nearest the touchdown began at 21:28 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
21:24 UTCTSTM WND DMG4 N FlyWilliamson, TNREPORT OF TREES DOWN ON NORTH LUCK CREEK RD IN THE PRIMM SPRINGS AREA.
21:24 UTCTSTM WND DMG9 S FairviewWilliamson, TNREPORT OF TREES AND POWER LINES DOWN ON NORTH LICK CREEK RD IN THE PRIMM SPRINGS AREA.
21:28 UTCTORNADO8 S FairviewWilliamson, TNA BRIEF EF-0 TORNADO TOUCHED DOWN IN FAR SOUTHWESTERN WILLIAMSON COUNTY CAUSING MOSTLY TREE DAMAGE ON GREEN CHAPEL ROAD. THE TORNADO CONTINUED EAST AND CAUSED MINOR TREE DAMAGE ON NORTH LICK CREEK ROAD. DRONE FOOTAGE FRO
21:55 UTCTSTM WND DMG5 W FranklinWilliamson, TNTSPOTTER REPORT OF A TREE DOWN IN BLOSSOM PARK
22:12 UTCTSTM WND DMG7 E Thompson'S StationWilliamson, TNTREE DOWN AT PULLTIGHT HILL RD AND CROSS KEYS RD
22:16 UTCFLASH FLOOD1 S FranklinWilliamson, TNREPORT OF WATER COVERING ROADS AT INTERSECTION OF SOUTHWINDS DRIVE AND KENNEDY COURT.
22:20 UTCFLASH FLOOD1 Ne FranklinWilliamson, TNWATER COVERING ASPEN ROAD AND JORDAN ROAD INTERSECTION. WATER ON RUSH STREET AS WELL.
22:22 UTCFLASH FLOOD3 Wsw ArringtonWilliamson, TNESTIMATED 3 TO 6 OF WATER ON RAOADS AT INTERSECTION OF ARNO AND PEYTONSVILLE TRINITY ROADS.
22:22 UTCFLASH FLOOD3 Wsw ArringtonWilliamson, TNESTIMATED 3 TO 6 OF WATER ON ROADS AT INTERSECTION OF ARNO AND PEYTONSVILLE TRINITY ROADS.
22:45 UTCFLASH FLOODNolensvilleWilliamson, TNINTERSECTION OF NOLENSVILLE RD AND CLOVERCROFT RD IS IMPASSABLE.
22:56 UTCFLASH FLOOD3 Ne La VergneRutherford, TNTSPOTTER REPORT OF STREET FLOODING OCCURING BETWEEN SAND HILL CEMETERY AND SMYRNA AIRPORT
23:23 UTCFLASH FLOOD2 Wnw NolensvilleWilliamson, TNTSPOTTER REPORT OF THE NOLENSVILLE REC CENTER PARKING LOT UNDER WATER.
23:30 UTCFLASH FLOOD1 W NolensvilleWilliamson, TNTSPOTTER REPORT OF BITTOCKS CREEK THAT FLOWS THROUGH BENT CREEK IN NOLENSVILLE WELL OUT OF ITS BANKS

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 TennesseeEvery tornado in Tennessee since 1950Warnings in force in Tennessee nowThe forecast where you are

The other tornadoes of September 1, 2020

6 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
September 11:59 PM CDTEF1Conway, AR3.2100$100,000
September 12:13 PM CDTEF0Faulkner, AR3.250
September 13:07 PM CDTEF2Cleburne, AR5.3150$50,000
September 14:14 PM CDTEF0Pemiscot, MO2.150
September 15:24 PM CDTEF0Lake, TN2.150
September 17:10 PM CDTUnratedHall, TX0.030

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.