The heavy showers have caused Flash Flood Warnings across Central Texas and prompted officials to close low-water crossings, roads and parks.

A flash flood is a rapid rise of water along a stream or in a low-lying urban area, the National Weather Service said. Flash flooding can result from slow-moving thunderstorms, from numerous thunderstorms that develop repeatedly over the same area, or from heavy rains associated with tropical cyclones.

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.

Communities in rural Vermont face damaged homes and washed-out roads after heavy rainfall caused flash flooding.

Dangerous flash floods stranded motorists and left roadways under water. Some outdoor activities were canceled as communities scurried to keep pace with the rising waters.

The National Weather Service in Pueblo issued a flash flood warning Saturday evening for Costilla and Huerfano counties in southern Colorado. The impacted area is about 35 miles north of the New Mexico state line.

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.

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.