Tornadoes · United States · Utah · 2010

EF0 tornado, (4hv)Hanksville to (Hve)Hanksville Arpt, Utah, October 6, 2010

From (4hv)Hanksville to (Hve)Hanksville Arpt, this EF0 tornado ran 1.2 miles across Wayne County on October 6, 2010, touching down at 2:00 PM MDT and reaching 10 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
October 6, 2010
Touchdown
2:00 PM MDT (20:00 UTC)
Lifted
2:05 PM MDT (20:05 UTC)
On the ground
5 minutes
Path length
1.2 miles (2.0 km)
Path width
10 yards (9 m)
Deaths
0
Injuries
0
County
Wayne County
Touchdown point
38.280, -110.280
Lift-off point
38.285, -110.258
Record number
1010061400-01

What the Weather Service recorded

With a nearly stationary upper level low over California, large amounts of moisture spread into Utah. This allowed numerous showers and thunderstorms to develop across the state, with severe thunderstorms developing primarily across southern and eastern Utah, and widespread flooding occurring across southern Utah.

An EF0 tornado touched down west of Canyonlands National Park, at the south end of Robbers Roost Flat. Approximately 30 juniper trees were either snapped or uprooted by the tornado. No monetary damage occurred as the tornado occurred in a rural area and no trees fell on the nearby dirt road, so no cleanup was necessary.

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.

The county was under a tornado watch, issued at 16:29 UTC and running to 22:12 UTC.

Issued (UTC)ExpiredProductOffice
15:54 UTC15:15 UTCFlood WarningSLC
16:29 UTC22:12 UTCTornado WatchSLC
18:45 UTC19:45 UTCSevere Thunderstorm WarningSLC
19:47 UTC20:30 UTCSevere Thunderstorm WarningSLC
20:29 UTC21:15 UTCSevere Thunderstorm WarningSLC

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 19:38 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.

Grand Junction, CO (KGJT), 12:00Z

8.0 hours before the tornado, 180 km from the path. October 6, 2010.

Skew-T log-pSkew-T log-p diagram, Grand Junction, CO at 12:00Z on 2010-10-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 145 joules per kilogram, CIN -68, lifted condensation level 1023 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 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, Grand Junction, CO at 12:00Z on 2010-10-06The 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 47 square meters per square second, 0 to 6 km bulk shear 33 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
145 J/kg
Mixed-layer CIN
-68 J/kg
Surface CAPE
239 J/kg
Mixed-layer LCL
1023 m above ground
0-6 km bulk shear
33 kt
0-1 km bulk shear
17 kt
0-1 km storm-relative helicity
47 m²/s²
0-3 km storm-relative helicity
61 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
6.1 K/km

Open this sounding in Storm Lab

Grand Junction, CO (KGJT), 00:00Z

4.0 hours after it, 180 km from the path. October 7, 2010.

Skew-T log-pSkew-T log-p diagram, Grand Junction, CO at 00:00Z on 2010-10-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 17 joules per kilogram, CIN -73, lifted condensation level 1413 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, Grand Junction, CO at 00:00Z on 2010-10-07The 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 -157 square meters per square second, 0 to 6 km bulk shear 24 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
17 J/kg
Mixed-layer CIN
-73 J/kg
Surface CAPE
46 J/kg
Mixed-layer LCL
1413 m above ground
0-6 km bulk shear
24 kt
0-1 km bulk shear
36 kt
0-1 km storm-relative helicity
-157 m²/s²
0-3 km storm-relative helicity
-129 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
6.4 K/km

Open this sounding in Storm Lab

The radar

The Grand Junction radar (KGJX), 198 km away, was scanning. The volume nearest the touchdown began at 20:01 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
19:45 UTCFLOOD5 Nw Goblin ValleyEmery, UTROAD TO LITTLE WILD HORSE CANYON WASHED OUT.
20:00 UTCTORNADO23 Wsw Canyonlands NpWayne, UT25-30 JUNIPER TREES SNAPPED OVER OR UPROOTED. BASED ON PICTURES AND DESCRIPTION OF DAMAGE...INITIAL RATING IS EF0.

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

This ground now

The live radar over the trackEvery 2010 tornado in UtahEvery tornado in Utah since 1950Warnings in force in Utah nowThe forecast where you are

The other tornadoes of October 6, 2010

11 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
October 61:50 AM MSTEF2Coconino, AZ14.8400
October 64:55 AM MSTEF2Coconino, AZ4.9400
October 65:07 AM MSTEF2Coconino, AZ26.05007$1.0 million
October 65:54 AM MSTEF3Coconino, AZ30.1800$400,000
October 66:50 AM MSTEF2Coconino, AZ18.6600
October 68:29 AM MSTEF1Coconino, AZ0.7100
October 69:10 AM MSTEF1Coconino, AZ1.1100
October 610:30 AM MSTEF0Yavapai, AZ4.050
October 611:15 AM MSTEF3Coconino, AZ4.01,100$200,000
October 612:10 PM MSTEF0Coconino, AZ3.8200
October 612:20 PM MSTEF0Coconino, AZ1.7100

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.