EF0 tornado, Lexington Arpt, Nebraska, June 1, 2011

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.

Rating

EF0

Date

June 1, 2011

Touchdown

6:22 PM CDT (23:22 UTC)

Lifted

6:23 PM CDT (23:23 UTC)

On the ground

1 minutes

Path length

0.1 miles (0.2 km)

Path width

15 yards (14 m)

Deaths

0

Injuries

0

County

Dawson County

Touchdown point

40.780, -99.819

Lift-off point

40.780, -99.817

Record number

1106011722-01

Less than 48 hours after a line of damaging winds marched across much of South Central Nebraska, another widespread round of severe weather targeted primarily the southwest quadrant of the area on this Wednesday, mainly south of Interstate 80 and west of state Highway 10 in the vicinity of a surface warm front. Duration-wise, this was one of the most prolific severe weather events of the 2011 season, with convective warnings in effect for parts of the area for over 9 straight hours from around 4 PM to 130 AM CDT. Storm report highlights included numerous instances of large hail from quarter to baseball size, an estimated wind gust to 80 MPH, and a brief EF0 tornado west of Lexington. Many areas also measured 1-2 inches of rain in a short time, with one storm sending a few inches of water running through an Elm Creek grocery store.||This event essentially consisted of multiple, splitting supercell storms developing and tracking over the same areas. The first supercells developed just west and southwest of the area around 4 PM CDT and soon pushed into Dawson and Furnas Counties. These and other storms pounded the area for a few hours into the early evening, featuring the brief tornado near Lexington, and baseball size hail near Cozad. Following a brief lull in areal coverage of severe storms, considerable redevelopment took place between 8 PM and 10 PM CDT, with these storms also remaining severe as they evolved over the next few hours. Although most activity weakened or moved out of the area by midnight, one last supercell dropped golf ball size hail in northern Buffalo County shortly before 1 AM CDT. ||Although the mesoscale environment was supportive of severe weather, the long-lasting nature of this event was somewhat unexpected given a lack of large-scale forcing. The mid-levels featured only subtle, weak shortwave energy, well downstream from a powerful trough centered along the Pacific Northwest coast. However, deep-layer vertical wind shear around 40 knots, in combination with high mixed-layer CAPE values of 2500-4000 J/kg at the onset of the event made for a very conducive supercell environment. The primary instigator for multiple rounds of supercells was a persistent southerly low-level jet impinging over the north side of an effective surface warm front stretched from southwest Nebraska to east central Kansas. Winds along the nose of this jet at the 850-millibar level accelerated to 50 knots during the evening. This created very strong low-level wind shear and a mesoscale environment quite favorable for tornadoes. A review of radar data suggests that multiple storm-scale interactions, along with the outflow-dominant nature of some supercells likely spared South Central Nebraska from a more significant tornado threat.

A brief rope tornado was reported in the Darr interchange area. No damage was reported.

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

20 minutes of warning. NWS GID issued a tornado warning for this county at 23:02 UTC, 20 minutes before the tornado touched down, in force until 23:30 UTC.

The county was under a tornado watch, issued at 21:45 UTC and running to 05:00 UTC.

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 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 19:45 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 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.

The Grand Island radar (KUEX), 127 km away, was scanning. The volume nearest the touchdown began at 23:21 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.

Local storm reports within 60 km of the path, in the three hours either side.

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

The live radar over the trackEvery 2011 tornado in NebraskaEvery tornado in Nebraska since 1950Warnings in force in Nebraska nowThe forecast where you are

11 more were confirmed in the United States that day.

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.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.