Tornadoes · United States · Colorado · 2015

EF0 tornado, Vona to Stratton, Colorado, June 5, 2015

From Vona to Stratton, this EF0 tornado ran 2.0 miles across Kit Carson County on June 5, 2015, touching down at 6:45 PM MDT and reaching 150 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 mphthis tornado

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

  2. EF186 to 110 mph

    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
EF0
Date
June 5, 2015
Touchdown
6:45 PM MDT (00:45 UTC)
Lifted
6:53 PM MDT (00:53 UTC)
On the ground
8 minutes
Path length
2.0 miles (3.2 km)
Path width
150 yards (137 m)
Deaths
0
Injuries
0
County
Kit Carson County
Touchdown point
39.510, -102.591
Lift-off point
39.522, -102.558
Record number
1506051845-01

What the Weather Service recorded

Late in the afternoon through evening a series of strong to severe storms moved across East Central Colorado producing tornadoes, large hail and flash flooding. One tornado was reported north of Vona and another south of Kirk. The largest hail reported was two inches in diameter south of Cope. Due to the slow storm motion and heavy rainfall, flash flooding occurred 8 WSW of Idalia just south of Highway 34 northeast to the Highway 36/385 intersection. In this area roads were impassable due to water over them. There was also significant field flooding and a trailer house near the Highway 26/385 intersection was surrounded by water almost touching the structure. Estimated wind gusts of 85 mph laid over pine trees and bent a radio tower west of Kanorado in Colorado.

Law enforcement and trained spotters reported a large tornado over open fields about 9 miles north of Vona. No damage was reported.

A storm chaser reported a large tornado crossing the road about a mile in front of him about 12 miles north of Stratton. No damage was relayed to the National Weather Service.

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

The warnings

27 minutes of warning. NWS GLD issued a tornado warning for this county at 00:18 UTC, 27 minutes before the tornado touched down, in force until 00:45 UTC.

The county was under a tornado watch, issued at 22:44 UTC and running to 02:04 UTC.

Issued (UTC)ExpiredProductOffice
07:12 UTC08:15 UTCSevere Thunderstorm WarningGLD
09:29 UTC13:30 UTCFlash Flood WarningGLD
22:44 UTC23:30 UTCTornado WarningGLD
22:44 UTC02:04 UTCTornado WatchGLD
22:49 UTC23:15 UTCSevere Thunderstorm WarningGLD
23:06 UTC04:29 UTCFlash Flood WatchGLD
23:15 UTC00:00 UTCTornado WarningGLD
23:19 UTC23:45 UTCTornado WarningGLD
23:45 UTC00:15 UTCTornado WarningGLD
23:56 UTC00:45 UTCSevere Thunderstorm WarningGLD
00:14 UTC00:29 UTCTornado WarningGLD
00:18 UTC00:49 UTCSevere Thunderstorm WarningGLD
00:18 UTC00:45 UTCTornado WarningGLD
00:24 UTC03:30 UTCFlash Flood WarningGLD
00:38 UTC01:30 UTCTornado WarningGLD
00:39 UTC01:04 UTCTornado WarningGLD
01:21 UTC04:15 UTCFlash Flood WarningGLD

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 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 19:28 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.

Denver, CO (KDEN), 00:00Z

0.8 hours before the tornado, 69 km from the path. June 6, 2015.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 00:00Z on 2015-06-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -85126, lifted condensation level 1609 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 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, Denver, CO at 00:00Z on 2015-06-06The 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 -1 square meters per square second, 0 to 6 km bulk shear 40 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
0 J/kg
Mixed-layer CIN
-85126 J/kg
Surface CAPE
1286 J/kg
Mixed-layer LCL
1609 m above ground
0-6 km bulk shear
40 kt
0-1 km bulk shear
7 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
122 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.4
0-3 km lapse rate
7.6 K/km

Open this sounding in Storm Lab

Denver, CO (KDEN), 12:00Z

11.2 hours after it, 69 km from the path. June 6, 2015.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2015-06-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -75617, lifted condensation level 1624 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 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, Denver, CO at 12:00Z on 2015-06-06The 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 0 square meters per square second, 0 to 6 km bulk shear 37 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
0 J/kg
Mixed-layer CIN
-75617 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1624 m above ground
0-6 km bulk shear
37 kt
0-1 km bulk shear
7 kt
0-1 km storm-relative helicity
0 m²/s²
0-3 km storm-relative helicity
48 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.1 K/km

Open this sounding in Storm Lab

The surface observations

Burlington (ITR), 39 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
22:53 UTC7864110° 13 kt1016.3
23:31 UTC776390° 14 kt1014.9TS
23:53 UTC7265110° 11 kt1015.6TSRA
00:20 UTC6964320° 9 kt141016.9+TSRA
00:28 UTC6562300° 10 kt231019+TSRA FG
00:49 UTC64.457.260° 10 kt141017.6TSRA
00:53 UTC645860° 11 kt151017.3-TSRA
01:01 UTC635850° 17 kt1017.3TS
01:12 UTC655770° 11 kt161017.3VCTS
01:21 UTC6757160° 8 kt1017.6
01:53 UTC7055 3 kt1018.3

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

The radar

The Goodland radar (KGLD), 77 km away, was scanning. The volume nearest the touchdown began at 00:42 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
22:08 UTCHAIL 0.882 Nnw ThurmanWashington, CO
23:01 UTCTORNADO4 Ssw Arickaree SchoolWashington, COLARGE CONE TORNADO ON GROUND PERSISTED FOR 7 MINUTES BEFORE BECOMING RAIN WRAPPED.
23:09 UTCHAIL 212 S CopeKit Carson, COAVERAGE SIZE OF THE HAIL WAS NICKEL.
23:20 UTCTORNADO9 N VonaKit Carson, COSHERIFF OFFICER REPORTED A LARGE TORNADO NORTH OF VONA. LOCATION ESTIMATED BY RADAR.
23:20 UTCTORNADO9 N VonaKit Carson, COLARGE CONE TORANDO OBSERVED NORTH OF VONA. LOCATION ESTIMATED BY RADAR.
23:45 UTCTORNADO9 S KirkKit Carson, COLARGE TORNADO CROSSED THE ROAD ONE MILE IN FRONT OF CHASER.
00:00 UTCHAIL 1.25KirkYuma, CO
00:42 UTCTSTM WND DMG1 Wsw KanoradoKit Carson, CO5 LARGE TREES LAID OVER DUE TO POSSIBLE TORNADO. TIME AND LOCATION ESTIMATED BY RADAR.
01:12 UTCFLASH FLOODBurlingtonKit Carson, COWATER OVER ROADS IN BURLINGTON.
01:15 UTCFLASH FLOOD8 Wsw IdaliaYuma, COLARGE AREA OF RAIDLY RUSH WATER OVER COUNTY RD V SOUTH OF RT 35. ROAD IMPASSABLE. SIGNIFICANT FIELD FLOODING IN AREA.
02:12 UTCFLASH FLOOD2 Ne IdaliaYuma, COMOBILE HOME OBSERVED COMPLETELY SURROUNDED BY WATER JUST NW OF INTERSECTION OF HWY 36 AND HWY 385. WATER TOUCHING ALL SIDES OF STRUCTURE. FIELDS FLOODED IN AREA.

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

This ground now

The live radar over the trackEvery 2015 tornado in ColoradoEvery tornado in Colorado since 1950Warnings in force in Colorado nowThe forecast where you are

The other tornadoes of June 5, 2015

7 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 53:24 AM MDTEF2Kit Carson, CO1.5300$30,000
June 51:13 PM MDTEF1Elbert, CO0.650
June 53:15 PM PDTEF1Mineral, NV1.540
June 54:54 PM MDTEF0Washington, CO0.1100
June 56:20 PM MDTEF0Kit Carson, CO4.5150
June 59:24 PM CDTEF0Logan, KS8.6100
June 59:30 PM CDTEF0Logan, KS0.110

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.