Radar data can estimate rainfall to a fairly accurate amount. The rain data in the case of the deadly tragedy that unfolded in the Texas Hill Country last weekend shows exactly why the area around Camp Mystic and the Guadalupe River, outside of San Antonio, had such a raging flash flood.

At least 80 people are dead after heavy rain led to "catastrophic" flooding in Texas. At least 41 people were missing statewide as of late Sunday afternoon, officials said. Kerr County was hit the hardest,