A warm front lifting across the Ohio Valley during the morning brought into the area a very unstable airmass. Numerous thunderstorms developed during the afternoon and evening. The environment was favorable for large hail and damaging winds. However, a few boundaries helped to produce localized favorable conditions for tornadoes. In addition, some storms occurred repeatedly over the same areas, causing an increased risk for flash flooding and flooding to occur.

Hail in CLERMONT, OHIO
From 01-MAY-12 17:25:00 to 01-MAY-12 17:29:00 (EST-5)
Location: BATAVIA
Magnitude: 1.00 
Reported by: Public

Thunderstorm Wind in CLERMONT, OHIO
From 01-MAY-12 17:27:00 to 01-MAY-12 17:31:00 (EST-5)
Location: GOSHEN
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A tree fell on the roof of a house due to damaging thunderstorm winds.

Hail in CLINTON, OHIO
From 01-MAY-12 17:24:00 to 01-MAY-12 17:28:00 (EST-5)
Location: WILMINGTON
Magnitude: 1.00 
Reported by: NWS Employee

Hail in ROSS, OHIO
From 01-MAY-12 17:55:00 to 01-MAY-12 17:59:00 (EST-5)
Location: CHILLICOTHE
Magnitude: 1.75 
Reported by: Trained Spotter

Hail in ROSS, OHIO
From 01-MAY-12 18:00:00 to 01-MAY-12 18:04:00 (EST-5)
Location: CHILLICOTHE
Magnitude: 1.00 
Reported by: Public

Thunderstorm Wind in ADAMS, OHIO
From 01-MAY-12 18:25:00 to 01-MAY-12 18:29:00 (EST-5)
Location: PEEBLES
Magnitude: 50.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Department of Highways

Trees were reported down due to damaging thunderstorm winds.

Hail in ADAMS, OHIO
From 01-MAY-12 18:27:00 to 01-MAY-12 18:31:00 (EST-5)
Location: PEEBLES
Magnitude: 0.88 
Reported by: Trained Spotter

Hail in PIKE, OHIO
From 01-MAY-12 18:20:00 to 01-MAY-12 18:24:00 (EST-5)
Location: WAVERLY
Magnitude: 1.75 
Reported by: Trained Spotter

Thunderstorm Wind in SCIOTO, OHIO
From 01-MAY-12 18:40:00 to 01-MAY-12 18:44:00 (EST-5)
Location: RARDEN
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Six trees were reported down on roads in the area due to damaging thunderstorm winds.

Thunderstorm Wind in PIKE, OHIO
From 01-MAY-12 18:45:00 to 01-MAY-12 18:49:00 (EST-5)
Location: PIKETON
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Several trees were reported down due to damaging thunderstorm winds.

Hail in SCIOTO, OHIO
From 01-MAY-12 18:56:00 to 01-MAY-12 19:00:00 (EST-5)
Location: SOUTH WEBSTER
Magnitude: 1.25 
Reported by: Broadcast Media

Flash Flood in HAMILTON, OHIO
From 01-MAY-12 17:05:00 to 01-MAY-12 18:05:00 (EST-5)
Location: WYOMING
Flood cause: Heavy Rain
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Water one foot deep was flowing over a road due to heavy rainfall. Other high water was also reported in the area.

Heavy Rain in CLARK, OHIO
From 01-MAY-12 18:05:00 to 01-MAY-12 19:00:00 (EST-5)
Location: SPRINGFIELD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Water was reported over a roadway due to heavy rainfall.

Flash Flood in BUTLER, OHIO
From 01-MAY-12 22:00:00 to 02-MAY-12 00:00:00 (EST-5)
Location: OKEANA
Flood cause: Heavy Rain
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Water at least 2 feet deep was reported flowing through portions of Morgan Township.

Flash Flood in HAMILTON, OHIO
From 02-MAY-12 01:00:00 to 02-MAY-12 02:00:00 (EST-5)
Location: TWIGHTWEE
Flood cause: Heavy Rain
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Department of Highways

Water around one foot deep was flowing off a hillside onto Kemper Road near Loveland Road due to heavy rainfall.

Flash Flood in HIGHLAND, OHIO
From 01-MAY-12 23:30:00 to 02-MAY-12 00:30:00 (EST-5)
Location: CAREYTOWN
Flood cause: Heavy Rain
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A foot of water was reported flowing over Powell Road.

Tornado in WARREN, OHIO
From 01-MAY-12 17:20:00 to 01-MAY-12 17:21:00 (EST-5)
Location: LEBANON WARREN CO AR
Tornado F-scale: EF0
Property damage: 5.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

The brief tornado touched down and caused damage to one structure, auto damage, and damage to outdoor furniture. Based on the damage surveyed, the maximum estimated wind speed of this tornado was 80 miles per hour.

Tornado in WARREN, OHIO
From 01-MAY-12 17:24:00 to 01-MAY-12 17:25:00 (EST-5)
Location: GENNTOWN
Tornado F-scale: EF0
Property damage: 10.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

The tornado touched down and uprooted or snapped about 10 to 15 trees. Minor structural damage also occurred. Based on the damage surveyed, the maximum estimated wind speed of this tornado was 80 miles per hour.

Thunderstorm Wind in DARKE, OHIO
From 01-MAY-12 16:29:00 to 01-MAY-12 16:30:00 (EST-5)
Location: NEW MADISON
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Several trees were reported down due to damaging thunderstorm winds.

Hail in HAMILTON, OHIO
From 01-MAY-12 16:29:00 to 01-MAY-12 16:33:00 (EST-5)
Location: WHITE OAK
Magnitude: 1.75 
Reported by: Broadcast Media

Hail in HAMILTON, OHIO
From 01-MAY-12 16:45:00 to 01-MAY-12 16:49:00 (EST-5)
Location: WYOMING
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in HAMILTON, OHIO
From 01-MAY-12 16:55:00 to 01-MAY-12 16:59:00 (EST-5)
Location: DEER PARK
Magnitude: 1.75 
Reported by: Trained Spotter

Hail in HAMILTON, OHIO
From 01-MAY-12 16:32:00 to 01-MAY-12 16:36:00 (EST-5)
Location: DENT
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in PICKAWAY, OHIO
From 01-MAY-12 17:43:00 to 01-MAY-12 17:47:00 (EST-5)
Location: WILLIAMSPORT
Magnitude: 0.75 
Reported by: Trained Spotter

Hail in HAMILTON, OHIO
From 01-MAY-12 16:45:00 to 01-MAY-12 16:49:00 (EST-5)
Location: CINCINNATI
Magnitude: 1.75 
Reported by: Public

Hail in DARKE, OHIO
From 01-MAY-12 16:35:00 to 01-MAY-12 16:39:00 (EST-5)
Location: ARCANUM
Magnitude: 1.75 
Reported by: Trained Spotter

Hail in DARKE, OHIO
From 01-MAY-12 16:40:00 to 01-MAY-12 16:44:00 (EST-5)
Location: ARCANUM
Magnitude: 1.00 
Reported by: Emergency Manager

Hail in HIGHLAND, OHIO
From 01-MAY-12 17:06:00 to 01-MAY-12 17:10:00 (EST-5)
Location: NEW MARKET
Magnitude: 1.00 
Property damage: 10.00K
Reported by: Public

Hail damage occurred to cars.

Flash Flood in HAMILTON, OHIO
From 01-MAY-12 19:25:00 to 01-MAY-12 20:25:00 (EST-5)
Location: SHARONVILLE
Flood cause: Heavy Rain
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Flooding of roads and properties were reported in the area due to heavy rain.

Flash Flood in HAMILTON, OHIO
From 01-MAY-12 18:00:00 to 01-MAY-12 21:00:00 (EST-5)
Location: WHITE WATER PARK
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Department of Highways

Heavy rainfall caused flash flooding in the area. High water was reported flowing over Lawrenceburg Road in Miami Township. Almost a foot of water was flowing across the road near the intersection of Harrison Avenue and Wesselman Road. Another road in the area was closed due to high water. A foot of water was reported flowing over Mount Hope Road.

Hail in ROSS, OHIO
From 01-MAY-12 18:00:00 to 01-MAY-12 18:04:00 (EST-5)
Location: CHILLICOTHE
Magnitude: 5.00 
Reported by: Public

A picture was taken of a 5 inch hailstone next to a ruler for measurement.

Hail in CLINTON, OHIO
From 01-MAY-12 17:18:00 to 01-MAY-12 17:24:00 (EST-5)
Location: WILMINGTON
Magnitude: 0.88 
Reported by: NWS Employee

Flash Flood in CLERMONT, OHIO
From 01-MAY-12 23:37:00 to 02-MAY-12 00:37:00 (EST-5)
Location: GOSHEN
Flood cause: Heavy Rain
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A woman was trapped in her car in flood waters caused by heavy rain.

Flash Flood in HIGHLAND, OHIO
From 02-MAY-12 00:00:00 to 02-MAY-12 01:00:00 (EST-5)
Location: HILLSBORO
Flood cause: Heavy Rain
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Very high water was reported over Route 62 and Highway 50 due to heavy rain.