I live on Princeton Road, just 5 minutes from Downtown Hamilton, Ohio, in Butler County. I saw a bright flash of green light on the northwestern horizon, towards New Miami. It was very close. I thought it was a transistor blowing, or powerlines coming down. I also saw a blackness backlit by lightning, but I don't know if it was a funnel cloud or a tornado, but there was a black mass in the sky, backlit by lightning. This was at app. 9:40pm EST.

i also live in hamilton about 3 min away from princton rd. on miami st. off of heaton st.  i did not see the green light but i did see the black mass

I saw the same thing here on the west side of hamilton. what you saw was a nicely sized wall cloud. possibly a funnel.