Tornadoes · United States · Colorado · 2012

EF0 tornado, Bennett, Colorado, June 15, 2012

This EF0 tornado ran 0.1 miles across Adams County on June 15, 2012, touching down at 2:56 PM MDT and reaching 50 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 15, 2012
Touchdown
2:56 PM MDT (20:56 UTC)
Lifted
3:06 PM MDT (21:06 UTC)
On the ground
10 minutes
Path length
0.1 miles (0.2 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
County
Adams County
Touchdown point
39.770, -104.420
Lift-off point
39.770, -104.420
Record number
1206151456-01

What the Weather Service recorded

A severe thunderstorm produced hail from quarter to half dollar size in Douglas and Jefferson Counties. A weak short lived tornado touched down in Adams County. In Lincoln County, a trained spotter measured a peak wind gust to 64 mph.

A weak tornado touched down but did no damage.

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 19:40 UTC and running to 00:07 UTC.

Issued (UTC)ExpiredProductOffice
19:40 UTC00:07 UTCSevere Thunderstorm WatchBOU
20:33 UTC21:15 UTCSevere Thunderstorm WarningBOU
21:02 UTC21:30 UTCTornado WarningBOU
21:52 UTC22:30 UTCSevere Thunderstorm WarningBOU

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. The outlook in force was issued at 20:11 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 (KDNR), 12:00Z

8.9 hours before the tornado, 102 km from the path. June 15, 2012.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2012-06-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 7 joules per kilogram, CIN -278, lifted condensation level 1830 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, Denver, CO at 12:00Z on 2012-06-15The 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 -227 square meters per square second, 0 to 6 km bulk shear 12 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
7 J/kg
Mixed-layer CIN
-278 J/kg
Surface CAPE
228 J/kg
Mixed-layer LCL
1830 m above ground
0-6 km bulk shear
12 kt
0-1 km bulk shear
39 kt
0-1 km storm-relative helicity
-227 m²/s²
0-3 km storm-relative helicity
9 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
6.7 K/km

Open this sounding in Storm Lab

Denver, CO (KDNR), 00:00Z

3.1 hours after it, 102 km from the path. June 16, 2012.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 00:00Z on 2012-06-16Temperature 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 -73057, lifted condensation level 3455 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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, Denver, CO at 00:00Z on 2012-06-16The 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 19 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
0 J/kg
Mixed-layer CIN
-73057 J/kg
Surface CAPE
240 J/kg
Mixed-layer LCL
3455 m above ground
0-6 km bulk shear
19 kt
0-1 km bulk shear
8 kt
0-1 km storm-relative helicity
0 m²/s²
0-3 km storm-relative helicity
21 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0
0-3 km lapse rate
8.2 K/km

Open this sounding in Storm Lab

The surface observations

Front Range (FTG), 11 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
19:11 UTC80.650140° 23 kt281016.3
19:31 UTC82.450150° 17 kt251016.3
19:49 UTC82.450140° 14 kt231016.3
19:51 UTC82.450150° 14 kt201016.3
20:11 UTC80.650140° 15 kt191016.6
20:30 UTC80.650130° 12 kt151016.3
20:50 UTC80.650140° 10 kt1016.3
20:59 UTC80.648.290° 10 kt211016.9-TSRAGR
21:10 UTC66.246.4200° 14 kt251017.6+FC -TSRAGR
21:11 UTC69.844.6240° 21 kt251017.6+TSRA
21:21 UTC66.244.6260° 25 kt461017.9+TSRA
21:31 UTC69.837.4300° 26 kt461018.3TSRA
21:47 UTC69.848.2150° 20 kt251018.3-TSRA
21:51 UTC69.846.4160° 20 kt251018.3-TSRA
22:11 UTC71.641140° 19 kt1016.9-VCTSRA
22:23 UTC73.44190° 19 kt381015.6VCTS
22:30 UTC71.641120° 15 kt251015.6
22:50 UTC73.441130° 14 kt1016.3

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

The radar

The Denver radar (KFTG), 11 km away, was scanning. The volume nearest the touchdown began at 20:57 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
20:18 UTCHAIL 1Highlands RanchDouglas, CO
20:23 UTCHAIL 1.25Highlands RanchDouglas, CO
21:06 UTCTORNADO1 N BennettAdams, COWEAK TORNADO IN OPEN FIELD ON GROUND FOR 10 MINUTES. NO DAMAGE REPORTED.

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

This ground now

The live radar over the trackEvery 2012 tornado in ColoradoEvery tornado in Colorado since 1950Warnings in force in Colorado 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.