During the afternoon, multi-cell thunderstorm clusters developed along a warm front that was oriented from west to east along the Interstate 64 corridor. Surface dew points near and south of the front were in the lower 70's, which contributed to strong instability. Thunderstorm clusters moved eastward along the warm front, but they also developed southward into the strongest instability. Moderately strong deep-layer wind shear resulted in the formation of an organized mesoscale convective system accompanied by locally damaging winds, isolated large hail, and isolated street flooding. There was also an isolated tornado associated with a short-lived supercell structure. A second line of storms arrived late in the evening and continued overnight. This second line produced isolated street flooding.

Hail in GIBSON, INDIANA
From 11-MAY-16 16:32:00 to 11-MAY-16 16:32:00 (CST-6)
Location: OWENSVILLE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in PIKE, INDIANA
From 11-MAY-16 18:15:00 to 11-MAY-16 18:15:00 (EST-5)
Location: WINSLOW
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind gusts were estimated to at least 55 mph.

Thunderstorm Wind in PIKE, INDIANA
From 11-MAY-16 18:00:00 to 11-MAY-16 18:00:00 (EST-5)
Location: WINSLOW
Magnitude: 52.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A couple of power lines were down.

Thunderstorm Wind in GIBSON, INDIANA
From 11-MAY-16 16:16:00 to 11-MAY-16 16:25:00 (CST-6)
Location: OWENSVILLE
Magnitude: 61.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Four large trees were blown down on a residential street. A trained spotter reported debris was flying through the air. A barn roof was blown off. Some large tree limbs were blown down.

Tornado in WARRICK, INDIANA
From 11-MAY-16 16:58:00 to 11-MAY-16 16:58:00 (CST-6)
Location: LYNNVILLE
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported a very brief tornado just west of the Interlake State Recreation Area and east of Indiana Highway 61. No damage was located in this rural area.

Flood in GIBSON, INDIANA
From 11-MAY-16 16:40:00 to 11-MAY-16 18:00:00 (CST-6)
Location: OWENSVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported a few streets were underwater in Owensville, following three inches of rain during a severe thunderstorm.

Flood in POSEY, INDIANA
From 11-MAY-16 23:00:00 to 12-MAY-16 01:15:00 (CST-6)
Location: MT VERNON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Street flooding was reported in Mount Vernon, including flooding of the main streets.

Thunderstorm Wind in VANDERBURGH, INDIANA
From 11-MAY-16 16:38:00 to 11-MAY-16 16:38:00 (CST-6)
Location: EVANSVILLE
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Just southeast of Evansville, wind gusts from 50 to 60 mph were estimated in the Angel Mounds area.

Tornado in GIBSON, INDIANA
From 11-MAY-16 16:02:00 to 11-MAY-16 16:03:00 (CST-6)
Location: JOHNSON
Tornado F-scale: EF1
Property damage: 5.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Trees were snapped and uprooted. The tornado track ended on Indiana Route 165 about two miles west of Owensville. Maximum winds were estimated near 95 mph.

Thunderstorm Wind in VANDERBURGH, INDIANA
From 11-MAY-16 17:02:00 to 11-MAY-16 17:02:00 (CST-6)
Location: EVANSVILLE
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

For the second time in a half-hour, wind gusts from 50 to 60 mph were estimated in the Angel Mounds area.

Thunderstorm Wind in VANDERBURGH, INDIANA
From 11-MAY-16 16:17:00 to 11-MAY-16 16:25:00 (CST-6)
Location: MC CUTCHANVILLE
Magnitude: 62.00 MG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Broadcast Media

A swath of moderate tree damage occurred in the northern and western parts of the Evansville metro area. About three miles north of Evansville in Igleheart Park, many large oak trees were snapped, including some that were two to three feet in diameter. Several other tree limbs were downed, including some up to 15 feet long and three inches in diameter. On the north side of Evansville, a large tree fell on a house, causing minor to moderate damage. Just southwest of Evansville near the University of Southern Indiana, a fallen tree blocked a street and winds gusted to 71 mph. A couple miles northwest of McCutchanville, two-inch diameter tree limbs were blown down. The damaging winds occurred along a gust front just ahead of the leading edge of precipitation.