The threat of heavy rain is “slight” for this weekend, but with the ground fully saturated in Kerr County even small amounts of rainfall could cause flooding.

Thirteen people are dead and more than 20 people unaccounted for after heavy rain lashed Texas, leading to "catastrophic" flooding. Children are among the dead, and about 23 campers from a summer camp in the area, Camp Mystic, are unaccounted for, said Lt. Gov. Dan Patrick, who has taken on the duties of acting governor.

Using Fredericksburg as a proxy for the region, the average July rainfall over the last about 40 years is 2.2 inches. But most of the time, July seems to be closer to either extreme, whether it’s less than an inch or more than four.