EF1 tornado, Everton to Hickory Barren, Missouri, June 18, 2011

1. EF065 to 85 mph

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. EF186 to 110 mphthis tornado

   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

EF1

Date

June 18, 2011

Touchdown

11:35 PM CDT (04:35 UTC)

Lifted

11:50 PM CDT (04:50 UTC)

On the ground

15 minutes

Path length

10.9 miles (17.5 km)

Path width

200 yards (183 m)

Deaths

0

Injuries

0

Counties

Dade and Greene counties

Touchdown point

37.380, -93.650

Lift-off point

37.399, -93.453

Record number

1106182235-01

A frontal boundary across the area and an upper level disturbance moving across the central Plains into the Ozarks caused a cluster of strong to severe storms to develop. Storms produced high winds and large hail across the area.

A NWS survey team determined that an EF-1 tornado with winds estimated of 80 to 90 mph touched down about four miles northeast of Everton. The tornado had a path width of 100 yards and snapped and uprooted several trees for two miles before entering Greene County just west of the Sac River along Farm Road 130. The tornado had a total path length of 11 miles before lifting about six miles east of Walnut Grove in Greene County.

A NWS survey team determined that an EF-1 tornado with winds estimated of 80 to 90 mph touched down about four miles northeast of Everton and continued into Greene County. The tornado had a path width of 100 to 200 yards and continued for 9 miles snapping and uprooting several trees after entering Greene County just west of the Sac River along Farm Road 130. The tornado had a total path length of 11 miles before lifting about six miles east of Walnut Grove in Greene County.

A NWS survey team determined that an EF-1 tornado with winds estimated at 80 to 90 mph touched down about two miles southeast of Dadeville in eastern Dade County. This tornado had a path width of 100 yards and continued eastward into Polk County where it lifted about one mile south of Eudora. This tornado snapped and uprooted several trees and destroyed and outbuilding before entering Polk County.

Ground survey confirmed an EF-0 tornado produced 70 to 80 mph winds along an east southeast path between three miles southeast of Brighton, just north of the Greene County line, to Highway H in northern Greene County four miles south of Pleasant Hope. The tornado damaged trees as it entered Greene County and proceeded on an intermittent path damaging trees, destroying a metal barn and causing damage to siding and roofs on a few homes.

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

5 minutes of warning. NWS SGF issued a tornado warning for this county at 04:30 UTC, 5 minutes before the tornado touched down, in force until 04:54 UTC.

The county was under a severe thunderstorm watch, issued at 23:05 UTC and running to 09:00 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 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 01:00 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.

Springfield (SGF), 22 km from the path, in the two hours either side.

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

The Springfield radar (KSGF), 22 km away, was scanning. The volume nearest the touchdown began at 04:32 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 MissouriEvery tornado in Missouri since 1950Warnings in force in Missouri nowThe forecast where you are

10 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.