Tornadoes · United States · Colorado · 2016

EF0 tornado, Otis Stansfield Arpt, Colorado, September 2, 2016

This EF0 tornado ran 0.0 miles across Washington County on September 2, 2016, touching down at 4:05 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
September 2, 2016
Touchdown
4:05 PM MDT (22:05 UTC)
Path length
0.0 miles (0.0 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
County
Washington County
Touchdown point
40.220, -102.870
Lift-off point
40.220, -102.870
Record number
1609021605-01

What the Weather Service recorded

Severe thunderstorms produced a brief tornado in Washington County and hail up to nickel size in Logan County.

A tornado touched down briefly but no damage was observed.

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.

Issued (UTC)ExpiredProductOffice
21:46 UTC22:30 UTCSevere Thunderstorm WarningBOU
22:07 UTC22:30 UTCTornado 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 Marginal Risk. The outlook in force was issued at 19:47 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), 12:00Z

10.1 hours before the tornado, 50 km from the path. September 2, 2016.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2016-09-02Temperature 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 -81309, lifted condensation level 2206 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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, Denver, CO at 12:00Z on 2016-09-02The 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 80 square meters per square second, 0 to 6 km bulk shear 23 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
0 J/kg
Mixed-layer CIN
-81309 J/kg
Surface CAPE
200 J/kg
Mixed-layer LCL
2206 m above ground
0-6 km bulk shear
23 kt
0-1 km bulk shear
17 kt
0-1 km storm-relative helicity
80 m²/s²
0-3 km storm-relative helicity
29 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.9 K/km

Open this sounding in Storm Lab

Denver, CO (KDEN), 00:00Z

1.9 hours after it, 50 km from the path. September 3, 2016.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 00:00Z on 2016-09-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 26 joules per kilogram, CIN -66, lifted condensation level 2607 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, Denver, CO at 00:00Z on 2016-09-03The 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 37 square meters per square second, 0 to 6 km bulk shear 42 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
26 J/kg
Mixed-layer CIN
-66 J/kg
Surface CAPE
431 J/kg
Mixed-layer LCL
2607 m above ground
0-6 km bulk shear
42 kt
0-1 km bulk shear
9 kt
0-1 km storm-relative helicity
37 m²/s²
0-3 km storm-relative helicity
64 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
9.2 K/km

Open this sounding in Storm Lab

The surface observations

Akron/Washington Co (AKO), 30 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
20:05 UTC200° 8 kt1017.3
20:10 UTC180° 5 kt1016.9
20:15 UTC160° 11 kt1016.9
20:20 UTC200° 4 kt1016.9
20:25 UTC140° 10 kt1016.9
20:30 UTC200° 7 kt1016.6
20:35 UTC190° 7 kt1016.6
20:40 UTC150° 9 kt1016.6
20:45 UTC130° 8 kt1016.3
20:50 UTC160° 18 kt1016.9-RA
20:51 UTC75.259150° 15 kt251016.9-TSRA
20:53 UTC7359130° 16 kt271016.9+TSRA
20:55 UTC7058 6 kt271016.9+TSRA
20:57 UTC6857 1017.3+TSRA
21:00 UTC 1016.6+RA
21:05 UTC 1016.3-RA
21:06 UTC665840° 14 kt171016.3-TSRA
21:10 UTC 1015.9-RA
21:13 UTC665940° 9 kt1015.9TS
21:15 UTC 1015.9
21:20 UTC50° 9 kt1015.9
21:24 UTC706050° 8 kt1015.9VCTS
21:25 UTC50° 8 kt1015.9
21:26 UTC706050° 8 kt1015.6
21:30 UTC40° 6 kt1015.6
21:35 UTC60° 5 kt1015.6
21:40 UTC70° 6 kt1015.6
21:43 UTC796280° 6 kt1015.6VCTS
21:45 UTC70° 7 kt1015.6
21:50 UTC130° 15 kt1015.2
21:53 UTC796190° 11 kt221015.2
21:55 UTC 1015.2
22:00 UTC70° 9 kt1014.9
22:05 UTC110° 5 kt1015.2
22:10 UTC170° 9 kt1015.2
22:15 UTC160° 16 kt1015.2
22:20 UTC150° 15 kt1015.2
22:25 UTC120° 5 kt1014.9
22:30 UTC150° 11 kt181014.9
22:35 UTC130° 8 kt1014.9
22:40 UTC130° 7 kt1014.9
22:45 UTC60° 13 kt201014.9
22:50 UTC50° 7 kt1014.9
22:53 UTC776340° 18 kt231014.9
22:55 UTC 1014.9
23:00 UTC50° 7 kt1014.9
23:05 UTC 161014.9
23:10 UTC50° 8 kt1014.9
23:15 UTC 1014.9
23:20 UTC 1014.9
23:25 UTC 1014.9
23:30 UTC 1014.9
23:35 UTC 1014.9
23:40 UTC 1014.9
23:45 UTC60° 16 kt1014.9
23:50 UTC50° 13 kt1014.9
23:53 UTC756250° 12 kt201014.9
23:55 UTC40° 12 kt1014.9
00:00 UTC 1014.9

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

The radar

The Goodland radar (KGLD), 138 km away, was scanning. The volume nearest the touchdown began at 22:06 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
21:07 UTCHAIL 0.88SterlingLogan, CO
22:05 UTCTORNADO7 Ne OtisWashington, CO
22:40 UTCTSTM WND GST 607 Sw ClarkvilleYuma, COPEA SIZE HAIL ALSO REPORTED.
23:00 UTCFUNNEL CLOUD9 Sse ClarkvilleYuma, COLOCATION ESTIMATED.
00:50 UTCHEAVY RAIN 5.56 Wnw WaunetaYuma, COREPORT FORWARDED TO THE OFFICE VIA NWSCHAT FROM EMERGENCY MANAGER.

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 ColoradoEvery tornado in Colorado since 1950Warnings in force in Colorado nowThe forecast where you are

The other tornadoes of September 2, 2016

5 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
September 23:50 AM EDTEF1Liberty, GA4.8650
September 25:12 AM EDTEF1Chatham, GA1.4350
September 29:20 PM EDTEF1Carteret, NC0.150$150,000
September 29:23 PM EDTEF1Carteret, NC0.350$75,000
September 21:02 AM EDTEF0Dare, NC0.1253$250,000

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.