Flash floods in Texas have killed at least 107 people over the Fourth of July weekend, with more than 160 still missing.

Scholars and designers of early warning systems say that there are still huge gaps in our ability to predict flash floods and warn those at risk.

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.

Straighter, smoother streams flow more violently than those that meander due to a reduction in friction. Areas with steeper terrain can see water accelerate downhill at a much faster rate causing a more destructive flash flood than flatter, open areas.

In the Midwest, quarter-sized hail and an isolated tornado cannot be ruled out, while in the South, flood alerts are in effect for areas that were devastated by flash floods last week.

Search crews continued the grueling task of recovering the missing as more potential flash flooding threatened Texas Hill Country.

Back-to-back flooding disasters in recent years — in Texas, New Mexico and Kentucky, among many others — have showed that preparing for flash flooding is a new necessity as the planet warms. And there’s no more dangerous time for a flash flood than after dark;