Tornadoes · United States · Wyoming · 2016

EF1 tornado, Gillette to Rozet, Wyoming, August 7, 2016

From Gillette to Rozet, this EF1 tornado ran 1.5 miles across Campbell County on August 7, 2016, touching down at 7:55 PM MDT and reaching 365 yards wide. It killed nobody.

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 mph

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

  2. EF186 to 110 mphthis tornado

    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
EF1
Date
August 7, 2016
Touchdown
7:55 PM MDT (01:55 UTC)
Lifted
7:59 PM MDT (01:59 UTC)
On the ground
4 minutes
Path length
1.5 miles (2.4 km)
Path width
365 yards (334 m)
Deaths
0
Injuries
0
County
Campbell County
Touchdown point
44.289, -105.364
Lift-off point
44.297, -105.335
Record number
1608071955-01

What the Weather Service recorded

A severe thunderstorm tracked eastward across central Campbell County, producing hail and gusty winds east of Gillette. A tornado briefly touched down near Rozet.

About a dozen homes in the Freedom Hills subdivision were damaged by a EF-1 tornado. A fifth wheel camper was rolled down a hill.

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

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.

Issued (UTC)ExpiredProductOffice
00:50 UTC01:30 UTCSevere Thunderstorm WarningUNR
01:47 UTC02:15 UTCSevere Thunderstorm WarningUNR

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 01:00 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.

Rapid City, SD (KRAP), 00:00Z

1.9 hours before the tornado, 198 km from the path. August 8, 2016.

Skew-T log-pSkew-T log-p diagram, Rapid City, SD at 00:00Z on 2016-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 966 joules per kilogram, CIN -124, lifted condensation level 1514 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, Rapid City, SD at 00:00Z on 2016-08-08The 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 72 square meters per square second, 0 to 6 km bulk shear 34 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
966 J/kg
Mixed-layer CIN
-124 J/kg
Surface CAPE
1773 J/kg
Mixed-layer LCL
1514 m above ground
0-6 km bulk shear
34 kt
0-1 km bulk shear
9 kt
0-1 km storm-relative helicity
72 m²/s²
0-3 km storm-relative helicity
55 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.7
0-3 km lapse rate
7.5 K/km

Open this sounding in Storm Lab

Rapid City, SD (KRAP), 12:00Z

10.1 hours after it, 198 km from the path. August 8, 2016.

Skew-T log-pSkew-T log-p diagram, Rapid City, SD at 12:00Z on 2016-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 80 joules per kilogram, CIN -340, lifted condensation level 1984 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, Rapid City, SD at 12:00Z on 2016-08-08The 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 36 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
80 J/kg
Mixed-layer CIN
-340 J/kg
Surface CAPE
91 J/kg
Mixed-layer LCL
1984 m above ground
0-6 km bulk shear
29 kt
0-1 km bulk shear
26 kt
0-1 km storm-relative helicity
36 m²/s²
0-3 km storm-relative helicity
14 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.1 K/km

Open this sounding in Storm Lab

The surface observations

Gillette (GCC), 16 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
23:55 UTC130° 12 kt
00:00 UTC130° 14 kt
00:05 UTC140° 12 kt
00:10 UTC140° 14 kt
00:15 UTC140° 13 kt
00:20 UTC130° 11 kt
00:25 UTC150° 12 kt
00:30 UTC160° 11 kt1010.8
00:33 UTC8648160° 11 kt1010.8VCTS
00:35 UTC150° 9 kt
00:40 UTC140° 9 kt
00:45 UTC140° 7 kt
00:50 UTC150° 7 kt1010.8
00:53 UTC8453160° 8 kt1011.2TS
00:55 UTC150° 9 kt-RA
01:00 UTC150° 12 kt-RA
01:05 UTC100° 6 kt1011.2RA
01:10 UTC 1011.5RA
01:12 UTC69.860.8240° 24 kt1010.8+TSRA
01:15 UTC +RA
01:16 UTC6760240° 14 kt331012.2+TSRA
01:20 UTC0° 0 kt+RA FG
01:25 UTC6660 1011.9-TSRA
01:29 UTC676080° 10 kt1012.5-TSRA
01:30 UTC70° 10 kt1012.2RA
01:35 UTC10° 9 kt14RA
01:37 UTC725740° 16 kt331012.9+TSRA
01:40 UTC +RA
01:44 UTC6561340° 19 kt321012.5-TSRA BR
01:45 UTC -RA BR
01:50 UTC64.459310° 18 kt291012.2VCTS -RA
01:53 UTC6459300° 19 kt281012.5VCTS -RA
01:55 UTC -RA
02:00 UTC6459320° 14 kt261013.5VCTS
02:05 UTC300° 10 kt
02:10 UTC310° 12 kt1014.2
02:15 UTC340° 14 kt
02:20 UTC30° 12 kt
02:25 UTC30° 14 kt
02:28 UTC646030° 14 kt1011.9
02:30 UTC20° 13 kt1012.2
02:35 UTC10° 11 kt
02:40 UTC20° 9 kt
02:45 UTC10° 6 kt1012.9
02:50 UTC80° 5 kt1013.2
02:53 UTC6461100° 3 kt1012.9
02:55 UTC120° 3 kt
03:00 UTC0° 0 kt
03:05 UTC0° 0 kt
03:10 UTC0° 0 kt1012.9
03:15 UTC0° 0 kt
03:20 UTC0° 0 kt
03:25 UTC0° 0 kt
03:30 UTC0° 0 kt1012.9
03:35 UTC10° 8 kt
03:40 UTC20° 4 kt
03:45 UTC20° 5 kt
03:50 UTC40° 4 kt1013.9
03:53 UTC6561 3 kt1013.9

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

The radar

The Rapid City radar (KUDX), 202 km away, was scanning. The volume nearest the touchdown began at 01:54 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
00:40 UTCTSTM WND GST 5016 Wsw Downtown GillettCampbell, WY
01:24 UTCTSTM WND GST 502 Ene WestonCampbell, WY
01:55 UTCTSTM WND DMG7 E Downtown GilletteCampbell, WYABOUT A DOZEN HOMES SUSTAINED DAMAGE FROM GUSTY WINDS.
01:55 UTCTSTM WND DMG7 E Downtown GilletteCampbell, WYMOBILE HOME ROOF BLOWN OFF...CAMPERS TURNED OVER... POWER LINES DOWN
01:55 UTCTSTM WND DMG7 E Downtown GilletteCampbell, WY
01:55 UTCTORNADO7 E Downtown GilletteCampbell, WYPRELIMINARY EF1 TORNADO DAMAGED ABOUT A DOZEN HOMES IN THE FREEDOM HILLS SUBDIVISION ABOUT 1 -2 MILES EAST OF WYODAK SUNDAY NIGHT.
02:05 UTCTSTM WND GST 564 Ese RozetCampbell, WY
02:05 UTCHAIL 14 Ese RozetCampbell, WY

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

This ground now

The live radar over the trackEvery 2016 tornado in WyomingEvery tornado in Wyoming since 1950Warnings in force in Wyoming nowThe forecast where you are

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.