Severe weather in Oklahoma has left four people dead, including a 12-year-old boy and his mother, officials say.

Additional heavy rain is expected across the Plains this week. With streams already swollen and the ground saturated, that leaves the area at risk of additional flooding.

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.