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.

A Christian all-girls camp in central Texas said on Monday that 27 campers and counselors were among those who perished in the catastrophic flooding over the July 4 weekend, while emergency responders still searching for dozens of missing people faced the prospect of more heavy rains and thunderstorms.