Get ready, as more severe storms are expected to move into Oklahoma Monday night after flooding and tornado warnings over the weekend. >> Go to the KOCO weather page | Get KOCO on the Go | Subscribe to KOCO 5's YouTube channelSign up for our Newsletters11:20 a.

Millions in the Upper Midwest face the possibility of a severe thunderstorm outbreak Monday—the start of several days of extreme weather threats across the country this week.

A slow-moving, active storm system brought heavy rain, large hail and tornadoes to parts of Texas and Oklahoma and left three people dead as severe weather warnings Sunday continue to threaten parts of the south-central and Midwest U.