A very moist and unstable air mass combined with a cold front dropping south into the Ohio Valley to produce numerous areas of convection. The threats from these storms included large hail, damaging thunderstorm winds, and flash flooding.

Hail in HARDIN, OHIO
From 18-JUL-12 13:24:00 to 18-JUL-12 13:28:00 (EST-5)
Location: FORAKER
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in MADISON, OHIO
From 18-JUL-12 12:52:00 to 18-JUL-12 12:56:00 (EST-5)
Location: LONDON
Magnitude: 0.88 
Reported by: Trained Spotter

Hail in WARREN, OHIO
From 18-JUL-12 14:23:00 to 18-JUL-12 14:27:00 (EST-5)
Location: LELAN
Magnitude: 0.88 
Reported by: NWS Employee

Hail in HAMILTON, OHIO
From 18-JUL-12 15:15:00 to 18-JUL-12 15:19:00 (EST-5)
Location: MADEIRA
Magnitude: 1.25 
Reported by: Trained Spotter

Hail in HAMILTON, OHIO
From 18-JUL-12 15:24:00 to 18-JUL-12 15:28:00 (EST-5)
Location: HARRISON
Magnitude: 0.75 
Reported by: Public

Hail in CLERMONT, OHIO
From 18-JUL-12 15:10:00 to 18-JUL-12 15:25:00 (EST-5)
Location: LOVELAND
Magnitude: 1.00 
Reported by: Amateur Radio

The hail lasted for 15 minutes.

Thunderstorm Wind in HAMILTON, OHIO
From 18-JUL-12 15:35:00 to 18-JUL-12 15:39:00 (EST-5)
Location: WHITE WATER PARK
Magnitude: 50.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Several large trees fell into buildings due to thunderstorm winds.

Thunderstorm Wind in HAMILTON, OHIO
From 18-JUL-12 15:35:00 to 18-JUL-12 15:39:00 (EST-5)
Location: DELHI
Magnitude: 52.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Public

Trees were downed near Saylor Park due to damaging thunderstorm winds.

Thunderstorm Wind in HAMILTON, OHIO
From 18-JUL-12 15:35:00 to 18-JUL-12 15:36:00 (EST-5)
Location: DENT
Magnitude: 55.00 MG
Reported by: Trained Spotter

Flash Flood in HAMILTON, OHIO
From 18-JUL-12 16:15:00 to 18-JUL-12 16:45:00 (EST-5)
Location: CINCINNATI
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Public

Vehicles were reported trapped in high water due to heavy rainfall near Gest Street and Dalton Avenue.

Thunderstorm Wind in MONTGOMERY, OHIO
From 18-JUL-12 13:41:00 to 18-JUL-12 13:45:00 (EST-5)
Location: WEST CARROLLTON
Magnitude: 50.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Some 3 to 5 inch diameter limbs were downed due to damaging thunderstorm winds.

Thunderstorm Wind in AUGLAIZE, OHIO
From 18-JUL-12 13:08:00 to 18-JUL-12 13:12:00 (EST-5)
Location: LOCK TWO
Magnitude: 50.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A few 6 inch diameter limbs were reported down north of New Bremen due to damaging thunderstorm winds.

Heavy Rain in LOGAN, OHIO
From 18-JUL-12 14:01:00 to 18-JUL-12 14:31:00 (EST-5)
Location: BELLEFONTAINE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

There were reports of minor street flooding near the center of Bellefontaine town due to heavy rainfall.

Thunderstorm Wind in CLERMONT, OHIO
From 18-JUL-12 15:21:00 to 18-JUL-12 15:25:00 (EST-5)
Location: WITHAMSVILLE
Magnitude: 50.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Public

A large section of a tree was snapped off its base off of Glen Este-Withamsville Road due to damaging thunderstorm winds.

Thunderstorm Wind in CLERMONT, OHIO
From 18-JUL-12 15:35:00 to 18-JUL-12 15:39:00 (EST-5)
Location: AMELIA
Magnitude: 50.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trees and limbs were downed north of Amelia due to damaging thunderstorm winds.

Thunderstorm Wind in HAMILTON, OHIO
From 18-JUL-12 15:37:00 to 18-JUL-12 15:41:00 (EST-5)
Location: MACK
Magnitude: 50.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Public

Siding damage occurred to a house in Bridgetown due to thunderstorm winds.