A large area of severe thunderstorms is forecast into Tuesday night and will overlap areas in the Ohio, Tennessee and middle Mississippi valleys that were hit by deadly and damaging storms, forecasters say.

Severe weather leaves 28 dead, including at least 19 in storm-battered Kentucky. Storms Friday afternoon tore roofs off buildings, ripped bricks off of siding and downed trees and power lines.

Strong to severe storms possible overnight. Storms could bring damaging winds and large hail.

The National Weather Service and AccuWeather both warn of severe weather that could affect the Southeast region, though forecasts remain uncertain.

By Tuesday, more than four million will be under the highest risk of severe storms and tornadoes across central and eastern Oklahoma and into the Ozarks. Officials are warning of "significant multi-hazard severe weather including tornadoes - some potentially strong to intense - very large hail and severe winds".

Severe storms are expected to erupt across a wide swath of Texas late Monday — from the Dallas-Fort Worth area to East Texas.

A round of strong to severe storms starts the day as a warm front lifts northeastward. Warm and unstable air surges in behind this warm front with southern Kentucky hitting the 80s. Low pressure then rolls from west to east across the lower Ohio Valley. This puts Kentucky in the warm sector, leading to rounds of strong to severe storms.

University of Maryland, College Park officials said possible severe weather will delay the outdoor commencement ceremony.