Tornadoes · United States · Wyoming · 1989

F0 tornado, Johnson County, Wyoming, June 8, 1989

This F0 tornado ran 0.5 miles across Johnson County on June 8, 1989, touching down at 3:05 PM MDT and reaching 50 yards wide. It killed nobody.

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
June 8, 1989
Touchdown
3:05 PM MDT (21:05 UTC)
Path length
0.5 miles (0.8 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
County
Johnson County
Touchdown point
44.050, -106.280
Record number
507

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
20:09 UTC21:00 UTCTornado WarningCYS

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 General Thunderstorms Risk. The outlook in force was issued at 08:23 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.

Lander/Hunt Fiel, WY (KLND), 12:00Z

9.1 hours before the tornado, 238 km from the path. June 8, 1989.

Skew-T log-pSkew-T log-p diagram, Lander/Hunt Fiel, WY at 12:00Z on 1989-06-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 88 joules per kilogram, CIN -116, lifted condensation level 831 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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, Lander/Hunt Fiel, WY at 12:00Z on 1989-06-08The 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 9 square meters per square second, 0 to 6 km bulk shear 9 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
88 J/kg
Mixed-layer CIN
-116 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
831 m above ground
0-6 km bulk shear
9 kt
0-1 km bulk shear
6 kt
0-1 km storm-relative helicity
9 m²/s²
0-3 km storm-relative helicity
20 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.5 K/km

Open this sounding in Storm Lab

The surface observations

Gillette (GCC), 68 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
20:00 UTC734850° 4 kt
21:00 UTC7147100° 4 kt
22:00 UTC7546350° 4 kt
23:00 UTC744650° 5 kt

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

This ground now

The live radar over the trackEvery 1989 tornado in WyomingEvery tornado in Wyoming since 1950Warnings in force in Wyoming nowThe forecast where you are

The other tornadoes of June 8, 1989

25 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 86:04 AM CDTF2Iberville Parish, LA10.077230$500,000 to $5 million
June 86:06 AM CDTF0Escambia, FL0.210$50,000 to $500,000
June 86:30 AM CDTF2West Baton Rouge Parish, LA9.56060$500,000 to $5 million
June 87:00 AM CDTF2Livingston Parish, LA4.050$5,000 to $50,000
June 87:00 AM CDTF1Iberville Parish, LA2.550$5,000 to $50,000
June 87:25 AM CDTF1East Baton Rouge Parish, LA8.0771$50,000 to $500,000
June 87:46 AM CDTF0Bay, FL0.210
June 87:50 AM CDTF1Saint Helena Parish, LA2.040$50,000 to $500,000
June 87:57 AM CDTF1Livingston Parish, LA5.040$5,000 to $50,000
June 88:15 AM CDTF1Tangipahoa Parish, LA2.5401$50,000 to $500,000
June 89:51 AM CDTF1Baldwin, AL2.02010$500,000 to $5 million
June 89:55 AM CDTF0Baldwin, AL0.310
June 810:00 AM CDTF1Escambia, FL0.2101$5,000 to $50,000
June 810:45 AM CDTF1Jones, MS0.870$5,000 to $50,000
June 82:00 PM CDTF0Okaloosa, FL0.210$50,000 to $500,000
June 85:30 PM EDTF0Franklin, FL0.210
June 85:00 PM CDTF1Lauderdale, MS0.550$5,000 to $50,000
June 86:00 PM EDTF2Franklin, FL3.030034$500,000 to $5 million
June 86:05 PM EDTF0Franklin, FL0.210
June 84:15 PM MDTF1Arapahoe, CO0.120$50,000 to $500,000
June 87:30 PM EDTF1Wakulla, FL1.0301$5,000 to $50,000
June 85:45 PM MDTF0Santa Fe, NM2.023
June 86:12 PM MDTF1Santa Fe, NM5.050
June 88:50 PM EDTF1Mitchell, GA1.050$5,000 to $50,000
June 87:59 PM CDTF0Mobile, AL0.310

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.