And back here at home, millions of families in the American heartland are bracing for a burst of severe weather. Powerful winds, golf ball-sized hail and scanning the horizon for twisters. ABC's... See More
And back here at home, millions of families in the American heartland are bracing for a burst of severe weather. Powerful winds, golf ball-sized hail and scanning the horizon for twisters. ABC's meteorologist, ginger zee, with the new forecast. Reporter: Hail, smothering the heartland. The windshield is gone. Reporter: From Missouri to Texas, at least 45 reports of severe weather in the past 24 hours. Throwing rocks at you. Reporter: The hail so deep, it looks like snow. So big, it looks like golf balls. Tonight, this is the region under the gun. Hail, damaging winds and isolated tornadoes are the main threat. All of this, on the eve of the 40th anniversary of the infamous superoutbreak of 1974. One of the most violent tornado outbreaks in all recorded history. More than 140 twisters raked across the midwest, mid Mississippi valley and the southeast. We're watching a tornado watch in parts of Oklahoma, Kansas and Missouri. That's just tonight. The threat expands and intensifies as we go through the next 24 hours. So, this is for tomorrow. You're seeing that red area there, that includes Memphis, Little Rock, all the way up to places like St. Louis and Springfield. This would be large hail, damaging wind and isolated tornadoes. Diane, this is tomorrow afternoon and evening. We want everyone to be watching their local ABC stations for the very latest. All right, ginger. Thank you so much.
This transcript has been automatically generated and may not be 100% accurate.