EF0 tornado, Harrisonville, Missouri, June 8, 2010

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 8, 2010

Touchdown

5:39 PM CDT (22:39 UTC)

Lifted

5:44 PM CDT (22:44 UTC)

On the ground

5 minutes

Path length

2.1 miles (3.4 km)

Path width

20 yards (18 m)

Deaths

0

Injuries

0

Property damage

$10,000

County

Cass County

Touchdown point

38.640, -94.350

Lift-off point

38.639, -94.313

Record number

1006081639-01

In the wake of morning thunderstorms, afternoon sunshine heated an already very humid airmass over west central Missouri and eastern Kansas on Tuesday, June 8 2010, creating a very unstable atmosphere over the region. A slow moving cold front reached a Wichita to Kansas City line by late afternoon, rapidly igniting a long line of strong, slow moving thunderstorms. While the threat of damaging winds and large hail were diminished by the vast number of storms that developed along the front, excessive rainfall quickly became a concern. Training, or repeated thunderstorms tracking over the same area, deluged portions of the Kansas City metro into Cass County. Areas from Overland Park, to Grandview, to Lee's Summit, southward to Peculiar, Pleasant Hill, and adjacent communities, were hit especially hard as two and a half to four inches of rain fell in just a couple hours. Interstate 435 near the Kansas/Missouri state line was turned into a river at rush hour, with water rescues conducted near Cleveland, Missouri to the southeast. In addition to the torrential rainfall, these storms were prolific lightning producers, with nearly continuous cloud to ground lightning, observed well into the early evening hours. National lightning detection network counts, showed total cloud to ground lightning strikes well into the tens of thousands, but thankfully no damage was reported.||The only severe weather observed in the region, was with one of the first storms that developed in western Johnson County Kansas. This long lived supercell storm tracked southeast into Cass county, and began to show signs of organized rotation as it tracked toward Harrisonville, prompting the issuance of a tornado warning. A brief tornado touched down along the south side of Harrisonville, producing roof and tree damage to a church carport, a commercial business, and a number of trees at nearby residences.

Storm survey and eye witness accounts, confirm that an EF0 tornado touched down at 17:39 CST a little over one half mile south of Harrisonville. The tornado traveled around 2 miles to the east, before lifting at 17: 44 CST. A church had a roof blown off. There was also minor damage to a commercial building, and a number of trees were also damaged.

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

0 minutes of warning. NWS EAX issued a tornado warning for this county at 22:39 UTC, 0 minutes before the tornado touched down, in force until 23:00 UTC.

The county was under a tornado watch, issued at 19:39 UTC and running to 01:48 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 20:01 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.

Lee s Summit (LXT), 36 km from the path, in the two hours either side.

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

The Pleasant Hill radar (KEAX), 20 km away, was scanning. The volume nearest the touchdown began at 22:41 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 2010 tornado in MissouriEvery tornado in Missouri since 1950Warnings in force in Missouri nowThe forecast where you are

8 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.