Kerr County leaders say new Flash Flood Warning sirens are now active along parts of the Guadalupe River after last year's deadly floods.

The warning for Pearl River County is in effect until 4:30 p.m., while the advisory for St. Tammany Parish expires at 5 p.m.

Waymo recently recalled thousands of vehicles for a software issue with flood navigation, after one vehicle in San Antonio was swept into a creek.

New York City was pummeled with heavy rain and thunderstorms, leaving stranded drivers forced to seek refuge atop their cars amid the violent flash flooding. Wild footage showed cars being overwhelmed as a deluge of rain and 60-mph winds battered the city late Wednesday.

A flash flood warning continued for Atlanta, Druid Hills, and Emory in Georgia, on Wednesday as per the National Weather Service.

Flash floods happen when a huge amount of water rushes into an area faster than the ground, rivers, or drainage systems can handle it. Unlike regular floods, which can build over hours or days, flash floods can form within minutes after intense rain.

Heavy rains caused flash flooding across southern Oahu, Hawaii, on Friday afternoon, May 15, snarling traffic on major highways and prompting road closures and warnings from local authorities.