It's not all that unusual to see large temperature changes driven by strong cold fronts this time of year. Even though it is technically still summer, the sun isn't as strong as it was in early August. The early pushes of cooler air are becoming stronger and larger in extent. The polar jet stream is starting to become a more dominating force driving mid latitude systems the US and Canada much faster and with more punch. The front forecast to push through the Great Lakes late Wednesday/early Thursday is a prime example.
HUGE temperature contrast along the front.
Incidentally, last year almost to the day, we had a similar cold front and huge temperature contrast. We went from 96 and 95 to 62 in under 48 hours!
Atmosphere is very buoyant.
Precipitable water values are well over 2 inches!
Jet stream winds are very strong. Right-rear quadrant of the jet streak (diverging air aloft) over the mid-west will enhance the severe storms as they pass over Indiana and western Ohio.
Storm Prediction Center continues to show a slight risk for severe storms into northwestern Ohio for late Wednesday and early Thursday.
At this writing, line of storms should pass through northern Ohio between midnight Thursday and Thursday at 6am.
Temperatures will fall into the upper 50s and lower 60s Saturday.
The cool push of air is very strong and will envelop the northern 2/3rds of the US.