Tornadoes · United States · Wyoming · 2015

EF0 tornado, Douglas, Wyoming, June 16, 2015

Name: EF0 tornado, Douglas, Wyoming, June 16, 2015
Start: 2015-06-16T21:03:00.000Z
End: 2015-06-16T21:05:00.000Z
Location: Douglas, Wyoming

This EF0 tornado ran 1.0 miles across Converse County on June 16, 2015, touching down at 3:03 PM MDT and reaching 35 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.

EF065 to 85 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
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.
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.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
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: June 16, 2015
Touchdown: 3:03 PM MDT (21:03 UTC)
Lifted: 3:05 PM MDT (21:05 UTC)
On the ground: 2 minutes
Path length: 1.0 miles (1.6 km)
Path width: 35 yards (32 m)
Deaths: 0
Injuries: 0
County: Converse County
Touchdown point: 42.760, -105.774
Lift-off point: 42.760, -105.754
Record number: 1506161503-01

What the Weather Service recorded

Afternoon and early evening thunderstorms produced strong winds, funnel cloud, weak tornado, and numerous reports of large hail across portions of east central and southeast Wyoming.

An EF0 tornado touched down in open country just east of Box Elder Creek and was on the ground for two minutes before it lifted. No damage was reported.

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. One was issued for the county at another hour that day.

The county was under a severe thunderstorm watch, issued at 20:03 UTC and running to 03:00 UTC.

Issued (UTC)	Expired	Product	Office
20:03 UTC	03:00 UTC	Severe Thunderstorm Watch	CYS
21:00 UTC	21:45 UTC	Severe Thunderstorm Warning	CYS
21:11 UTC	21:45 UTC	Tornado Warning	CYS
21:41 UTC	22:16 UTC	Severe Thunderstorm Warning	CYS
22:43 UTC	23:30 UTC	Severe Thunderstorm Warning	CYS
00:03 UTC	00:30 UTC	Severe Thunderstorm Warning	CYS

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 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:46 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.

Riverton, WY (KRIW), 12:00Z

9.1 hours before the tornado, 217 km from the path. June 16, 2015.

Skew-T log-p

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.

Hodograph

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: 0 J/kg
Mixed-layer CIN: -86253 J/kg
Surface CAPE: 1 J/kg
Mixed-layer LCL: 1048 m above ground
0-6 km bulk shear: 58 kt
0-1 km bulk shear: 14 kt
0-1 km storm-relative helicity: 132 m²/s²
0-3 km storm-relative helicity: 155 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0
0-3 km lapse rate: 4.7 K/km

Open this sounding in Storm Lab

Riverton, WY (KRIW), 00:00Z

2.9 hours after it, 217 km from the path. June 17, 2015.

Skew-T log-p

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.

Hodograph

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: -80808 J/kg
Surface CAPE: 767 J/kg
Mixed-layer LCL: 2255 m above ground
0-6 km bulk shear: 59 kt
0-1 km bulk shear: 17 kt
0-1 km storm-relative helicity: 155 m²/s²
0-3 km storm-relative helicity: 330 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1
0-3 km lapse rate: 7.9 K/km

Open this sounding in Storm Lab

The surface observations

Douglas/Converse County Airport (DGW), 31 km from the path, in the two hours either side.

Time (UTC)	Temp (°F)	Dew point (°F)	Wind	Gust (kt)	Pressure (mb)	Weather
19:53 UTC	78	56	10° 7 kt		1017.6
20:53 UTC	73	57	20° 12 kt		1016.6	VCTS
21:23 UTC	67	59	50° 16 kt		1015.9	-TSRA
21:53 UTC	65	59	10° 11 kt	21	1016.9	VCTS -RA
22:30 UTC	65	57	40° 9 kt		1017.6
22:40 UTC	64	56	50° 11 kt		1017.6	-TSRA
22:53 UTC	64	57	40° 10 kt		1017.6	-TSRA

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

The radar

The Cheyenne radar (KCYS), 196 km away, was scanning. The volume nearest the touchdown began at 21:02 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)	Report	Where	County	Remark
21:03 UTC	TORNADO	20 W Douglas	Converse, WY	TORNADO WAS ON THE GROUND FOR 2 MINUTES.
21:03 UTC	TORNADO	20 W Douglas	Converse, WY
21:22 UTC	HAIL 1.75	17 W Douglas	Converse, WY	HAIL OCCURRED NEAR NATURAL BRIDGE.
21:26 UTC	HAIL 0.5	1 Sw Douglas	Converse, WY
22:45 UTC	HAIL 1.75	Douglas	Converse, WY	LATE REPORT.

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

This ground now

The live radar over the track Every 2015 tornado in Wyoming Every tornado in Wyoming since 1950 Warnings in force in Wyoming now The forecast where you are

The other tornadoes of June 16, 2015

1 more were confirmed in the United States that day.

Date	Time	Rating	Where	Path (mi)	Width (yd)	Deaths	Injuries	Damage
June 16	2:00 PM MDT	EF0	Uintah, UT	1.0	50

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.