Tornadoes · United States · Tennessee · 2017

EF0 tornado, Crump to Box Elder, Tennessee, August 31, 2017

From Crump to Box Elder, this EF0 tornado ran 1.3 miles across Hardin County on August 31, 2017, touching down at 3:07 PM CDT and reaching 50 yards wide. It killed nobody, and did $10,000 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 31, 2017
Touchdown
3:07 PM CDT (20:07 UTC)
Lifted
3:09 PM CDT (20:09 UTC)
On the ground
2 minutes
Path length
1.3 miles (2.0 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
Property damage
$10,000
County
Hardin County
Touchdown point
35.229, -88.341
Lift-off point
35.246, -88.351
Record number
1708311407-01

What the Weather Service recorded

The remnants of Harvey tracked across the Mid-South with heavy rain and gusty winds. There were several reports of flash flooding and a few tornadoes.

A weak tornado damaged irrigation equipment near Crump. Peak winds estimated at 60 mph.

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

The warnings

20 minutes of warning. NWS MEG issued a tornado warning for this county at 19:47 UTC, 20 minutes before the tornado touched down, in force until 20:30 UTC.

The county was under a tornado watch, issued at 16:15 UTC and running to 00:54 UTC.

Issued (UTC)ExpiredProductOffice
16:15 UTC00:54 UTCTornado WatchMEG
18:00 UTC19:42 UTCWind AdvisoryMEG
19:47 UTC20:30 UTCTornado WarningMEG
20:10 UTC20:38 UTCTornado WarningMEG
22:21 UTC04:15 UTCFlash Flood WarningMEG
23:08 UTC05:15 UTCFlash Flood WarningMEG

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 Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 19:57 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.

Little Rock, AR (KBYH), 12:00Z

8.1 hours before the tornado, 153 km from the path. August 31, 2017.

Skew-T log-pSkew-T log-p diagram, Little Rock, AR at 12:00Z on 2017-08-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 20 joules per kilogram, CIN -77, lifted condensation level 525 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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, Little Rock, AR at 12:00Z on 2017-08-31The 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 -15 square meters per square second, 0 to 6 km bulk shear 2 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
20 J/kg
Mixed-layer CIN
-77 J/kg
Surface CAPE
13 J/kg
Mixed-layer LCL
525 m above ground
0-6 km bulk shear
2 kt
0-1 km bulk shear
18 kt
0-1 km storm-relative helicity
-15 m²/s²
0-3 km storm-relative helicity
26 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.4 K/km

Open this sounding in Storm Lab

Little Rock, AR (KBYH), 00:00Z

3.9 hours after it, 153 km from the path. September 1, 2017.

Skew-T log-pSkew-T log-p diagram, Little Rock, AR at 00:00Z on 2017-09-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 150 joules per kilogram, CIN -3, lifted condensation level 824 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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, Little Rock, AR at 00:00Z on 2017-09-01The 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 65 square meters per square second, 0 to 6 km bulk shear 19 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
150 J/kg
Mixed-layer CIN
-3 J/kg
Surface CAPE
519 J/kg
Mixed-layer LCL
824 m above ground
0-6 km bulk shear
19 kt
0-1 km bulk shear
28 kt
0-1 km storm-relative helicity
65 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4
0-3 km lapse rate
6.5 K/km

Open this sounding in Storm Lab

The radar

The Memphis radar (KNQA), 139 km away, was scanning. The volume nearest the touchdown began at 20:03 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
20:16 UTCTORNADO5 Nw SavannahHardin, TNBRIEF TORNADO ALONG COFFEE LANDING ROAD. A SHED WAS DESTROYED.
20:30 UTCNON-TSTM WND DMGCoffee LandingHardin, TNONE SHED WAS DESTROYED.
20:30 UTCNON-TSTM WND DMGCoffee LandingHardin, TNSHED DESTROYED. POSSIBLE TORNADO.
20:30 UTCNON-TSTM WND DMGOlive HillHardin, TN3 HOMES WITH MINOR DAMAGE..ROOF AND PORCH..2 WERE MOBILE HOMES. SEVERAL TREES DOWN AND AT LEAST ONE UTILTY POLE. POSSIBLE TORNADO.
21:30 UTCNON-TSTM WND DMGOlive HillHardin, TN3 HOMES WITH MINOR DAMAGE..ROOF AND PORCH..2 WERE MOBILE HOMES. SEVERAL TREES DOWN AND AT LEAST ONE UTILTY POLE. POSSIBLE TORNADO.
21:30 UTCTORNADOOlive HillHardin, TN3 HOMES WITH MINOR DAMAGE..ROOF AND PORCH..2 WERE MOBILE HOMES. SEVERAL TREES DOWN AND AT LEAST ONE UTILTY POLE.

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

This ground now

The live radar over the trackEvery 2017 tornado in TennesseeEvery tornado in Tennessee since 1950Warnings in force in Tennessee nowThe forecast where you are

The other tornadoes of August 31, 2017

15 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 318:19 AM CDTEF0Phillips, AR1.750$15,000
August 3111:57 AM CDTEF0Benton, MS0.330$25,000
August 311:13 PM CDTEF0Lee, MS1.140
August 311:23 PM CDTEF1Itawamba, MS2.5150$150,000
August 311:43 PM CDTEF0Prentiss, MS0.330$50,000
August 313:40 PM CDTEF2Pickens, AL31.26006
August 314:19 PM CDTEF0Perry, TN0.350$10,000
August 314:37 PM CDTEF0Hardin, TN0.870$10,000
August 315:11 PM CDTEF0Maury, TN3.475$10,000
August 316:57 PM CDTEF1Bibb, AL6.5100
August 317:28 PM CDTEF1Bibb, AL0.6200
August 317:42 PM CDTEF0Bibb, AL0.335
August 318:58 PM CDTEF2Cullman, AL13.6300
August 3111:21 PM CDTEF1Davidson, TN0.675$25,000
August 3111:47 PM CDTEF0Davidson, TN0.950$15,000

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.