Summer preview concludes - Big Weekend cooldown

The East and South might be baking under an early summer-like heat wave, but colder weather will spread across the U.S. this weekend.

The TemperatureRadar is showing most places east of the Rockies in the 80s with a few 90s in the Mid-Atlantic today. These hot temperatures are interacting with a slow-moving storm system to produce more severe storms across the Northeast and part of the Midwest and the Ohio Valley.

This is just a small preview of the big changes ahead. A storm system moving out of western Canada will drag a potent cold front across the Plains late Friday and Saturday before moving into the East and South on Sunday.

The WeatherRadar shows this system producing heavy rain and thunderstorms along its path. In the wake, a significantly colder air mass will settle southward across the U.S. Afternoon highs on Saturday will only be in the 50s and 60s across the southern Plains, while Minneapolis will be in the 40s and Chicago will barely hit 50s.

By Sunday, the East and South will only be in the 50s and 60s. This is in stark contrast to the 80s and 90s expected today.