Tornadoes · United States · Kansas · 2011
EF0 tornado, Densmore to Almena, Kansas, June 20, 2011
From Densmore to Almena, this EF0 tornado ran 1.6 miles across Norton County on June 20, 2011, touching down at 2:35 PM CDT and reaching 20 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 20, 2011
- Touchdown
- 2:35 PM CDT (19:35 UTC)
- Lifted
- 2:40 PM CDT (19:40 UTC)
- On the ground
- 5 minutes
- Path length
- 1.6 miles (2.5 km)
- Path width
- 20 yards (18 m)
- Deaths
- 0
- Injuries
- 0
- County
- Norton County
- Touchdown point
- 39.839, -99.647
- Lift-off point
- 39.857, -99.629
- Record number
- 1106201335-01
What the Weather Service recorded
A strong, slow-moving low pressure system moved across northwest Kansas during the afternoon, resulting in over a dozen tornadoes, some strong and long-lived. The strongest tornadoes occurred over Graham and Norton counties. Other reports of baseball sized hail were received.
Observer located 7 miles south of Norton viewing a tornado to their east. This location agrees with that of a storm chaser who saw a dusty tornado to his south at the same time. There is no known damage.
Four utility poles were broken, and other minor damage occurred nearby, as this brief tornado moved northeast.
Dusty tornado reported southeast of Almena. No known damage.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
9 minutes of warning. NWS GLD issued a tornado warning for this county at 19:26 UTC, 9 minutes before the tornado touched down, in force until 20:00 UTC.
The county was under a tornado watch, issued at 18:03 UTC and running to 00:50 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 12:53 UTC | 14:00 UTC | Severe Thunderstorm Warning | GLD |
| 13:41 UTC | 18:03 UTC | Severe Thunderstorm Watch | GLD |
| 18:03 UTC | 00:50 UTC | Tornado Watch | GLD |
| 18:26 UTC | 19:30 UTC | Tornado Warning | GLD |
| 19:03 UTC | 19:30 UTC | Tornado Warning | GLD |
| 19:26 UTC | 20:00 UTC | Tornado Warning | GLD |
| 19:57 UTC | 20:15 UTC | Tornado Warning | GLD |
| 22:57 UTC | 22:58 UTC | Tornado Warning | GLD |
| 23:25 UTC | 00:30 UTC | Tornado Warning | GLD |
| 00:50 UTC | 03:33 UTC | Tornado Watch | GLD |
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 16:04 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.
N. Platte/Lee Bi, NE (KLBF), 12:00Z
7.6 hours before the tornado, 164 km from the path. June 20, 2011.
- Mixed-layer CAPE
- 163 J/kg
- Mixed-layer CIN
- -253 J/kg
- Surface CAPE
- 75 J/kg
- Mixed-layer LCL
- 570 m above ground
- 0-6 km bulk shear
- 51 kt
- 0-1 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 159 m²/s²
- 0-3 km storm-relative helicity
- 34 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.5
- 0-3 km lapse rate
- 4.2 K/km
N. Platte/Lee Bi, NE (KLBF), 00:00Z
4.4 hours after it, 164 km from the path. June 21, 2011.
- Mixed-layer CAPE
- 109 J/kg
- Mixed-layer CIN
- -135 J/kg
- Surface CAPE
- 185 J/kg
- Mixed-layer LCL
- 552 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- 271 m²/s²
- 0-3 km storm-relative helicity
- 471 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
- 0-3 km lapse rate
- 5.1 K/km
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 |
|---|---|---|---|---|
| 18:55 UTC | TORNADO | 6 S Edmond | Graham, KS | 2 TORNADOES MOVING EAST CROSSING HWY 283 AT THIS TIME. |
| 18:57 UTC | HAIL 2.5 | 8 N Penokee | Graham, KS | WINDOWS ALL GONE ON WEST SIDE OF THE HOUSE. WINDS ESTIMATED AT 60MPH. |
| 19:00 UTC | TORNADO | 9 N Hill City | Graham, KS | LARGE TORNADO NOW BEING REPORT NEAR HWY 283. |
| 19:15 UTC | TORNADO | 7 Sse Norton | Norton, KS | PUBLIC AT 7 MILES SOUTH OF NORTON VIEWING TORNADO TO HIS/HER EAST. |
| 19:20 UTC | TSTM WND DMG | 8 N Hill City | Graham, KS | MULTIPLE POWER LINES DOWN. |
| 19:30 UTC | TORNADO | 2 Ssw Calvert | Norton, KS | TRAINED SPOTTER LOCATED 6 N NORTON REPORTING SMALLER TORNADO OUT AHEAD OF MAIN TORNADO LOOKING TO SOUTHEAST. |
| 19:30 UTC | TORNADO | 6 N Norton | Norton, KS | TRAINED SPOTTER LOCATED 6 N NORTON REPORTING SMALLER TORNADO OUT AHEAD OF MAIN TORNADO LOOKING TO SOUTHEAST. |
| 19:39 UTC | HAIL 0.88 | Norton | Norton, KS | |
| 19:41 UTC | TORNADO | Almena | Norton, KS | |
| 19:50 UTC | TORNADO | 2 Nw Long Island | Phillips, KS | LAW ENFORCEMENT REPORTS TORNADO 2 MILES NORTHWEST OF LONG ISLAND MOVING NORTHEAST. |
| 19:50 UTC | TORNADO | 4 Nw Long Island | Phillips, KS | DELAYED REPORT OF LIKELY TORNADO DAMAGE TO FARM BUILDINGS. |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2011 tornado in KansasEvery tornado in Kansas since 1950Warnings in force in Kansas nowThe forecast where you are
The other tornadoes of June 20, 2011
37 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| June 20 | 4:59 AM CDT | EF1 | Mahaska, IA | 0.3 | 75 | $150,000 | ||
| June 20 | 6:14 AM CDT | EF0 | Kankakee, IL | 2.4 | 100 | $100,000 | ||
| June 20 | 12:55 PM CDT | EF0 | Gove, KS | 1.1 | 25 | |||
| June 20 | 1:00 PM CDT | EF0 | Gove, KS | 2.7 | 25 | |||
| June 20 | 1:12 PM CDT | EF0 | Graham, KS | 4.8 | 25 | |||
| June 20 | 1:54 PM CDT | EF3 | Graham, KS | 11.9 | 600 | $6.0 million | ||
| June 20 | 1:57 PM CDT | EF1 | Graham, KS | 0.6 | 25 | $500,000 | ||
| June 20 | 2:04 PM CDT | EF1 | Graham, KS | 0.9 | 25 | $500,000 | ||
| June 20 | 2:15 PM CDT | EF0 | Norton, KS | 1.8 | 20 | |||
| June 20 | 2:22 PM CDT | EF0 | McLean, ND | 0.3 | 10 | |||
| June 20 | 2:25 PM CDT | EF3 | Norton, KS | 3.9 | 100 | $350,000 | ||
| June 20 | 2:26 PM CDT | EF1 | Norton, KS | 0.3 | 25 | $10,000 | ||
| June 20 | 2:30 PM CDT | EF2 | Norton, KS | 4.0 | 75 | $300,000 | ||
| June 20 | 2:41 PM CDT | EF3 | Norton, KS | 8.4 | 100 | $10 million | ||
| June 20 | 2:42 PM CDT | EF0 | Morton, ND | 0.3 | 30 | |||
| June 20 | 3:00 PM CDT | EF1 | Harlan, NE | 12.5 | 100 | $250,000 | ||
| June 20 | 3:35 PM CDT | EF0 | Phelps, NE | 4.8 | 300 | $750,000 | ||
| June 20 | 3:51 PM CDT | EF2 | Buffalo, NE | 4.0 | 440 | 1 | $750,000 | |
| June 20 | 4:09 PM CDT | EF3 | Buffalo, NE | 10.0 | 1,320 | $6.0 million | ||
| June 20 | 4:35 PM CDT | EF0 | Buffalo, NE | 3.6 | 50 | |||
| June 20 | 4:46 PM CDT | EF2 | Sherman, NE | 2.5 | 200 | $100,000 | ||
| June 20 | 5:05 PM CDT | EF0 | Howard, NE | 0.1 | 50 | $80,000 | ||
| June 20 | 5:25 PM CDT | EF2 | Hamilton, NE | 9.4 | 440 | $2.5 million | ||
| June 20 | 5:27 PM CDT | EF0 | Sheridan, KS | 0.5 | 10 | |||
| June 20 | 5:35 PM CDT | EF1 | Valley, NE | 1.0 | 100 | $50,000 | ||
| June 20 | 5:40 PM CDT | EF2 | York, NE | 15.3 | 440 | $3.5 million | ||
| June 20 | 6:02 PM CDT | EF3 | Polk, NE | 9.5 | 880 | $4.0 million | ||
| June 20 | 6:25 PM CDT | EF0 | Decatur, KS | 0.5 | 10 | |||
| June 20 | 6:44 PM CDT | EF0 | Norton, KS | 0.5 | 10 | |||
| June 20 | 6:45 PM CDT | EF0 | Decatur, KS | 0.5 | 10 | |||
| June 20 | 7:27 PM CDT | EF1 | Pierce, NE | 12.0 | 400 | |||
| June 20 | 8:00 PM CDT | EF1 | Dodge, NE | 6.5 | 700 | $280,000 | ||
| June 20 | 8:09 PM CDT | EF1 | Washington, NE | 7.3 | 850 | |||
| June 20 | 8:45 PM CDT | EF1 | Monona, IA | 7.1 | 300 | |||
| June 20 | 8:46 PM CDT | EF0 | Stephens, TX | 0.0 | 30 | |||
| June 20 | 9:40 PM CDT | EF0 | Plymouth, IA | 0.9 | 100 | $20,000 | ||
| June 20 | 11:22 PM CDT | EF1 | Kossuth, IA | 1.2 | 75 | $200,000 |
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.