Tornadoes · United States · Kansas · 1997

F0 tornado, Bennington to Verdi, Kansas, May 7, 1997

From Bennington to Verdi, this F0 tornado ran 5.0 miles across Ottawa County on May 7, 1997, touching down at 5:06 PM CDT and reaching 23 yards wide. It killed nobody, and did $30,000 of property damage.

The rating scale

Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  1. F040 to 72 mphthis tornado

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

  2. F173 to 112 mph

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. F2113 to 157 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. F3158 to 206 mph

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. F4207 to 260 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. F5261 to 318 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
F0
Date
May 7, 1997
Touchdown
5:06 PM CDT (22:06 UTC)
Path length
5.0 miles (8.0 km)
Path width
23 yards (21 m)
Deaths
0
Injuries
0
Property damage
$30,000
County
Ottawa County
Touchdown point
39.080, -97.530
Lift-off point
38.980, -97.500
Record number
141

What the Weather Service recorded

A tornado touched down briefly at several locations along a five mile path. It produced most of its damage 5 to 6 miles southeast of Bennington where it tore off shingles and blew out windows on one house and damaged two barns, including some of the farm machinery inside. The tornado also knocked over several trees.

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

The warnings

8 minutes of warning. NWS TOP issued a tornado warning for this county at 21:58 UTC, 8 minutes before the tornado touched down, in force until 22:30 UTC.

Issued (UTC)ExpiredProductOffice
21:20 UTC22:10 UTCSevere Thunderstorm WarningTOP
21:58 UTC22:30 UTCTornado WarningTOP
22:31 UTC23:05 UTCSevere Thunderstorm WarningTOP

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. The outlook in force was issued at 05:59 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.

Topeka, KS (KTOP), 12:00Z

10.1 hours before the tornado, 162 km from the path. May 7, 1997.

Skew-T log-pSkew-T log-p diagram, Topeka, KS at 12:00Z on 1997-05-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 463 joules per kilogram, CIN -188, lifted condensation level 833 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, Topeka, KS at 12:00Z on 1997-05-07The 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 310 square meters per square second, 0 to 6 km bulk shear 29 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
463 J/kg
Mixed-layer CIN
-188 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
833 m above ground
0-6 km bulk shear
29 kt
0-1 km bulk shear
39 kt
0-1 km storm-relative helicity
310 m²/s²
0-3 km storm-relative helicity
415 m²/s²
Significant tornado parameter
0.0
Supercell composite
5.6
0-3 km lapse rate
4.0 K/km

Open this sounding in Storm Lab

Topeka, KS (KTOP), 00:00Z

1.9 hours after it, 162 km from the path. May 8, 1997.

Skew-T log-pSkew-T log-p diagram, Topeka, KS at 00:00Z on 1997-05-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1465 joules per kilogram, CIN -2, lifted condensation level 785 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, Topeka, KS at 00:00Z on 1997-05-08The 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 208 square meters per square second, 0 to 6 km bulk shear 34 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
1465 J/kg
Mixed-layer CIN
-2 J/kg
Surface CAPE
1320 J/kg
Mixed-layer LCL
785 m above ground
0-6 km bulk shear
34 kt
0-1 km bulk shear
26 kt
0-1 km storm-relative helicity
208 m²/s²
0-3 km storm-relative helicity
298 m²/s²
Significant tornado parameter
1.9
Supercell composite
9.7
0-3 km lapse rate
5.9 K/km

Open this sounding in Storm Lab

The surface observations

Salina (SLN), 29 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
20:53 UTC8166190° 17 kt221009.1
21:53 UTC8065200° 17 kt241007.1
22:53 UTC7767190° 5 kt1007.8
23:09 UTC73.462.650° 14 kt211007.5
23:21 UTC69.860.880° 15 kt211006.8
23:37 UTC66.264.410° 22 kt291008.1
23:45 UTC64.462.620° 28 kt381007.8

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

This ground now

The live radar over the trackEvery 1997 tornado in KansasEvery tornado in Kansas since 1950Warnings in force in Kansas nowThe forecast where you are

The other tornadoes of May 7, 1997

16 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 74:08 PM CDTF0Lancaster, NE1.220
May 74:12 PM CDTF0Lancaster, NE1.820
May 74:14 PM CDTF0Gage, NE2.020
May 74:20 PM CDTF1Lancaster, NE4.0100$300,000
May 74:31 PM CDTF0Lancaster, NE2.520
May 77:00 PM CDTF0Grant, OK2.050$3,000
May 77:09 PM CDTF0Morris, KS0.123
May 77:39 PM CDTF0Gray, TX0.223
May 77:52 PM CDTF0Carson, TX0.523
May 77:52 PM CDTF0Grant, OK0.123
May 77:53 PM CDTF0Grant, OK0.123
May 77:58 PM CDTF0Kay, OK0.123
May 78:10 PM CDTF0Gray, TX1.050
May 79:05 PM CDTF0Wheeler, TX0.123
May 79:37 PM CDTF0Osage, OK0.130
May 710:02 PM CDTF0Osage, OK0.130

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.