The National Weather Service is warning that heavy rains beginning Saturday evening could trigger flash flooding across already saturated parts of the U.S. Southwest, with the threat expected to persist through Monday.
Some areas could see as much as 4 inches (10 centimeters) of rain, falling on a region that has endured a deadly autumn of soaking storms driven by a series of weather systems. The latest round of weather follows a string of rescues Friday in Arizona and Nevada, where several people were pulled from floodwaters.
"It's not going to take much rainfall to be impactful at all in some of these locations just because of how saturated they are," said Allison Santorelli, a meteorologist with the Weather Prediction Center in College Park, Maryland.
Flood watches have been posted for nearly all of Arizona, along with parts of southern Utah, southwestern Colorado, western New Mexico and a portion of southern Nevada. The watches cover the Four Corners region, the sparsely populated area where Arizona, Colorado, New Mexico and Utah meet, which has been hit especially hard by recent rains. Santorelli said the weekend storms were expected to produce both flash flooding and flooding along small streams.
The Phoenix Fire Department said in a post on X that crews rescued people from four vehicles stranded on flooded streets Friday night. In nearby Scottsdale, fire Capt. Dave Folio said on Facebook that firefighters were rescuing a person from one vehicle in floodwater when a second vehicle carrying two people drove into the same water and also had to be rescued.
Folio said in a video posted on Facebook that as little as 2 inches (5 centimeters) of water can "sweep your vehicle off its wheels," noting that the vehicles involved were sitting in 3 to 4 feet (0.9 to 1.2 meters) of water.
In Henderson, Nevada, just outside Las Vegas, crews carried out three swift-water rescues during a downpour Friday afternoon, according to a city spokesperson. One person was pulled from the roof of a vehicle stuck in floodwaters, two others were rescued after their vehicle was swept off the roadway, and a person rescued from a wash went into cardiac arrest and later died at a hospital.
Meanwhile, in Bullhead City, Arizona, along the California border, heavy rain Friday left water, rocks and debris scattered across streets and forced parks to close, the city said in posts on Facebook.
Officials across the region urged residents to take the flood watches seriously, particularly given how little additional rain is needed to cause problems on ground already saturated by weeks of storms.
