EF0 tornado, Carlinburg to Thurston, Kentucky, June 11, 2009

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 11, 2009

Touchdown

5:02 PM CDT (22:02 UTC)

Lifted

5:10 PM CDT (22:10 UTC)

On the ground

8 minutes

Path length

3.0 miles (4.8 km)

Path width

150 yards (137 m)

Deaths

0

Injuries

0

Crop damage

$13,000

Counties

Henderson, Daviess and Spencer counties

Touchdown point

37.889, -87.318

Lift-off point

37.877, -87.266

Record number

0906111602-02

Thunderstorms quickly formed across the Lower Wabash Valley and northwest Kentucky in the vicinity of an eastward moving upper level disturbance. The boundary layer air mass in this region was characterized by temperatures in the lower 80's and dew points in the lower 70's. The combination of a moist low level environment, slightly backed wind flow along a northwest to southeast oriented warm front, and at least 40 knots of deep westerly shear promoted semi-discrete supercells with large hail, damaging winds, and isolated tornadoes.

Thunderstorms quickly formed across the Lower Wabash Valley and northwest Kentucky in the vicinity of an eastward moving upper level disturbance. The boundary layer air mass in this region was characterized by temperatures in the lower 80's and dew points in the lower 70's. The combination of a moist low level environment, slightly backed wind flow along a northwest to southeast oriented warm front, and at least 40 knots of deep westerly shear promoted semi-discrete supercells with large hail, damaging winds, and isolated tornadoes.

One tree and dozens of tree limbs were blown down in a tree row in the center of a very large field. The damage was in agricultural bottomland of the Ohio River. Peak winds in this portion of the track were near 65 mph. The tornado continued into Daviess County.

This weak tornado continued from Henderson County into northwest Daviess County. The tornado remained over agricultural river bottomland. Only some crops were damaged. One-foot high corn was blown down and whipped around by winds estimated around 75 mph. The tornado continued across the Ohio River into Spencer County, Indiana.

This weak tornado continued from Daviess County, Kentucky across the Ohio River into Spencer County. The tornado remained over agricultural river bottomland, causing damage to corn crops and small tree limbs. Peak winds were estimated near 65 mph on this portion of the track.

There were multiple reports of a brief tornado touchdown near the intersection of Highways 405 and 1831. Some tree limbs were down.

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

11 minutes of warning. NWS PAH issued a tornado warning for this county at 21:51 UTC, 11 minutes before the tornado touched down, in force until 22:15 UTC.

The county was under a tornado watch, issued at 21:52 UTC and running to 23:43 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. The outlook in force was issued at 20:02 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.

Owensboro/Daviess (OWB), 19 km from the path, in the two hours either side.

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

The Evansville,IN radar (KVWX), 57 km away, was scanning. The volume nearest the touchdown began at 21:59 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 2009 tornado in KentuckyEvery tornado in Kentucky since 1950Warnings in force in Kentucky nowThe forecast where you are

5 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.