Tornadoes · United States · Oklahoma · 1997

F0 tornado, Roff, Oklahoma, May 25, 1997

This F0 tornado ran 0.5 miles across Pontotoc County on May 25, 1997, touching down at 7:58 PM CDT and reaching 30 yards wide. It killed nobody, and did $3,000 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 25, 1997
Touchdown
7:58 PM CDT (00:58 UTC)
Path length
0.5 miles (0.8 km)
Path width
30 yards (27 m)
Deaths
0
Injuries
0
Property damage
$3,000
County
Pontotoc County
Touchdown point
34.630, -96.700
Lift-off point
34.630, -96.700
Record number
1018

What the Weather Service recorded

Summary of events of the afternoon and evening of May 25, 1997:Severe thunderstorms developed during the afternoon in central Oklahoma and spread into southern Oklahoma during the late afternoon and evening. In all, thirteen tornadoes were confirmed, including an F2 tornado that tracked for 6 miles through McClain County southwest of Purcell. Some minor injuries were reported with one of the tornadoes, but no fatalities or serious injuries occurred. Reports of 3-inch hail, severe straight-line winds, and lightning damage were also received.One particularly strong supercell storm tracked across central Oklahoma, reaching its maximum strength and producing 3 tornadoes and extensive straight-line wind damage over Grady and McClain Counties. What follows here is an excerpt from a damage survey conducted by a National Weather Service meteorologist on May 26th, the day after the storm. "A large severe thunderstorm moved through northern and central Grady County into central and southern McClain County during the late afternoon on Sunday, 25 May 1997. Several reports were received immediately after the storm indicating significant wind damage, especially in southern McClain County southwest of Purcell. There also were numerous confirmed tornado sightings by storm spotters, chasers, local emergency management officials, and local residents.Findings indicate that 3 tornadoes occurred in this area. Most of the damage, and all of the significant structural damage, resulted from the first two tornadoes. Widespread tree damage in some areas, especially in McClain County, was attributed to straight-line winds.The first tornado, rated F1, began 3 miles northeast of Tabler at 15:14 CST and tracked just south of due east for about 2.5 miles before dissipating 2.5 miles SSW of Middleberg at 15:24 CST. Structural damage was confined to a dairy farm near the beginning of the track; otherwise, this tornado remained over mostly open country.The second and more significant tornado, rated F2, began 5 miles east of Criner, or 7 miles WSW of downtown Purcell, in southern McClain County. The beginning time of this tornado is less certain but is believed to be near or just after 16:00 CST. This tornado also tracked just south of due east for 6 miles, ending about 4 miles NW of Wayne or 4 miles S of downtown Purcell at around 16:24 CST. Numerous power lines were downed, prompting the temporary closing of both Highways 24 and 74 for a time Sunday evening. At least 18 dwellings, including mobile homes and permanent dwellings, were destroyed or suffered major damage. This probably was a multiple-vortex tornado, at least in its latter stages, based on eyewitness reports. A third small tornado, rated F0, formed around 16:32 CST and lasted about one or two minutes. It damaged an outbuilding and a few trees 2 miles NNE of Wayne in Southern McClain County, about 4 miles east of where the second tornado ended. No one was killed or seriously injured by any of the tornadoes, but several minor injuries were reported. "The remaining 10 tornadoes were associated with other severe thunderstorms, mainly across central and southern Oklahoma. The strongest of these occurred south of Duncan in Stephens County at 17:36 CST. Spotter and damage reports rated this as an F1 tornado. The remaining 9 tornadoes were all rated F0 and resulted in little or no damage. In chronological order, these tornadoes occurred on the Caddo Comanche County line between Cyril and Fletcher (16:27CST), south of Maysville in Garvin County (17:28 CST), east of Joy in Murray County (18:07 CST), south of Stratford in Garvin County (18:13 CST), east of Roff in Pontotoc County (18:53 CST), northeast of Mill Creek in Johnston County (19:20 CST), west-northwest of Madill in Marshall County, (19:43 CST), north of Tupelo in Coal County (19:48 CST), and northwest of Newkirk in Kay County (21:10 CST). Severe straight-line winds were estimated at up to 80 mph (southwest of Fittstown in Pontotoc County). Wind damage from thunderstorm winds occurred north of Tabler in Grady County, southwest of Purcell in McClain County, in Wynnewood in Garvin County, west of Hardy in Kay County, and west of Antlers in Pushmataha County. Hail up to 3 inches in diameter fell south of Stratford in Garvin County, and lightning damage was reported south of Duncan in Stephens County. See preceding individual Storm Data entries for further details and additional reports.

A tornado unroofed a barn and downed a swath of trees.

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

The warnings

31 minutes of warning. NWS OUN issued a tornado warning for this county at 00:27 UTC, 31 minutes before the tornado touched down, in force until 01:15 UTC.

Issued (UTC)ExpiredProductOffice
12:25 UTC13:00 UTCSevere Thunderstorm WarningOUN
23:31 UTC00:30 UTCSevere Thunderstorm WarningOUN
00:15 UTC01:15 UTCSevere Thunderstorm WarningOUN
00:27 UTC01:15 UTCTornado WarningOUN
01:05 UTC02:00 UTCTornado WarningOUN

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 Moderate Risk. The outlook in force was issued at 05:51 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.

Norman, OK (KOUN), 00:00Z

1.0 hours before the tornado, 92 km from the path. May 26, 1997.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 00:00Z on 1997-05-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 360 joules per kilogram, CIN -169, lifted condensation level 1368 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, Norman, OK at 00:00Z on 1997-05-26The 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 82 square meters per square second, 0 to 6 km bulk shear 56 knots.19395878Sfc1 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
360 J/kg
Mixed-layer CIN
-169 J/kg
Surface CAPE
1195 J/kg
Mixed-layer LCL
1368 m above ground
0-6 km bulk shear
56 kt
0-1 km bulk shear
13 kt
0-1 km storm-relative helicity
82 m²/s²
0-3 km storm-relative helicity
124 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4
0-3 km lapse rate
5.4 K/km

Open this sounding in Storm Lab

Norman, OK (KOUN), 12:00Z

11.0 hours after it, 92 km from the path. May 26, 1997.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 12:00Z on 1997-05-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 62 joules per kilogram, CIN -359, lifted condensation level 2056 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, Norman, OK at 12:00Z on 1997-05-26The 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 37 square meters per square second, 0 to 6 km bulk shear 39 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
62 J/kg
Mixed-layer CIN
-359 J/kg
Surface CAPE
1812 J/kg
Mixed-layer LCL
2056 m above ground
0-6 km bulk shear
39 kt
0-1 km bulk shear
7 kt
0-1 km storm-relative helicity
37 m²/s²
0-3 km storm-relative helicity
53 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.2
0-3 km lapse rate
5.2 K/km

Open this sounding in Storm Lab

The radar

The Norman radar (KTLX), 94 km away, was scanning. The volume nearest the touchdown began at 01:00 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 1997 tornado in OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are

The other tornadoes of May 25, 1997

52 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 2512:55 PM CDTF0Coles, IL0.110
May 254:14 PM CDTF1Grady, OK2.573$20,000
May 254:15 PM CDTF0Scott, KS2.050
May 254:20 PM CDTF0Barton, KS3.0100
May 254:25 PM CDTF0Russell, KS1.0100$20,000
May 254:29 PM CDTF0Finney, KS0.530$10,000
May 254:30 PM CDTF0Finney, KS0.530
May 254:44 PM CDTF0Trego, KS0.550
May 255:52 PM EDTF0Arlington, VA1.073$100,000
May 255:00 PM CDTF2McClain, OK6.01,3202$900,000
May 255:10 PM CDTF0Barton, KS1.0100
May 255:16 PM CDTF0Barton, KS1.0100
May 255:27 PM CDTF0Comanche, OK0.123
May 255:27 PM CDTF0Caddo, OK0.123
May 255:32 PM CDTF0McClain, OK0.220$1,000
May 255:35 PM CDTF0Ellsworth, KS0.550
May 255:36 PM CDTF0Ellsworth, KS1.0100
May 255:01 PM MDTF0Weld, CO0.150
May 257:20 PM EDTF1Cecil, MD0.5100$250,000
May 256:28 PM CDTF0Garvin, OK0.123
May 256:30 PM CDTF0Ellsworth, KS0.550
May 256:36 PM CDTF1Stephens, OK0.550$50,000
May 257:00 PM CDTF0Kingman, KS0.550
May 257:01 PM CDTF0Harper, KS1.050
May 257:07 PM CDTF0Murray, OK0.123
May 257:13 PM CDTF0Garvin, OK0.123
May 257:23 PM CDTF0Madison, AL0.230
May 257:24 PM CDTF1Montague, TX0.530$10,000
May 257:35 PM CDTF0Harper, KS0.550
May 257:35 PM CDTF0Reno, KS2.0100$250,000
May 257:36 PM CDTF0Harvey, KS1.050
May 257:48 PM CDTF0Harper, KS1.050
May 258:20 PM CDTF0Johnston, OK0.123
May 258:23 PM CDTF1Harvey, KS1.0100$70,000
May 258:34 PM CDTF0Montague, TX0.123
May 258:35 PM CDTF2Sumner, KS8.01,700$1.9 million
May 258:36 PM CDTF2Cooke, TX1.073$100,000
May 258:39 PM CDTF0Montague, TX0.123
May 258:43 PM CDTF0Marshall, OK0.123
May 258:48 PM CDTF0Coal, OK0.123
May 258:50 PM CDTF0Wabaunsee, KS0.123
May 259:00 PM CDTF0Sumner, KS9.0100
May 259:10 PM CDTF0Cooke, TX0.530
May 259:22 PM CDTF0Butler, KS0.550
May 259:39 PM CDTF1Cooke, TX3.050
May 259:40 PM CDTF0Butler, KS1.050
May 259:41 PM CDTF0Cooke, TX0.123
May 259:58 PM CDTF0Butler, KS0.550
May 2510:10 PM CDTF0Kay, OK0.150
May 2510:11 PM CDTF0Cooke, TX2.040
May 2510:43 PM CDTF0Greenwood, KS0.550
May 2512:20 AM CDTF0St. Clair, MO0.110$500,000

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.