Heads up if you're in the Hill Country or know someone who is. The threat for flash flooding in the areas devastated by last Friday's flooding have increased.

Betty Matteson’s four children, nine grandchildren and numerous great-grandchildren have squeezed into her Texas Hill Country home countless times since 1968.

The risk of the catastrophic flooding that struck Texas Hill Country as people slept on July 4 and left at least 120 dead was potentially underestimated by federal authorities, according to an ABC News analysis of Federal Emergency Management Agency data, satellite imagery and risk modeling.

The National Weather Service warned that the Guadalupe River could surge to nearly 15 feet—5 feet above flood stage—by Sunday afternoon.

Would a flood scale like those used for hurricanes and tornadoes have prompted different actions by Texas officals and the public before July 4th flooding?

Kerr County failed to secure a warning system, even as local officials remained aware of the risks and as billions of dollars were available for similar projects.

Ground search operations were suspended Sunday in Kerr County, Texas, where crews have continued to look for those still lost after catastrophic July 4 flooding.