PHOENIX – Parts of the Southwest were getting a second soaking Wednesday, a day after monsoon rains swamped the desert region, stranding drivers, flooding streets and prompting water rescues.

Forecasters warned of the potential of more flooding in six states – Arizona, New Mexico, Colorado, Nevada, Utah and California, particularly in washes and streams.

Rain was falling in the Four Corners region but there were no reports of flooding or mudslides. More intense monsoon rain was expected in that area through Friday, according to the National Weather Service.

Flood watches in effect covered large swaths of desert and forests and cities such as Phoenix, Las Vegas, Tucson and Albuquerque. There was some flooding in the Arizona border city of Nogales.

Meteorologist Ken Drozd said more than an inch of rain fell on the U.S. side of the border along with 2 inches on the Mexico side, overwhelming washes and some streets. Fire officials, however, said the water was receding by late afternoon and traffic was moving normally.

A flash-flood watch remained in effect until late Wednesday night for the Phoenix metro area and parts of Maricopa, Pinal and Gila counties – meaning flooding was possible in washes, creeks and drainage areas.

Just over a month ago in Phoenix, residents were swapping social media photos of boiling temperature readings. Now, images of flooded streets and dark skies were being shared after a storm dropped 2 inches of rain in an hour in some spots Tuesday.

The rains bring some relief to crews fighting wildfires but also the potential for mudslides in areas blackened by flames. Because of the moisture, forest managers have been allowing wildfires to burn in areas where they didn’t threaten structures or public safety.

While there are fears that lightning could spark new blazes and strong winds could fan them, flooding remained the main threat, according to the National Weather Service in Flagstaff, Arizona.

The weather wreaked havoc on Tuesday evening’s commute. Flooding closed an Interstate 17 underpass in Phoenix for five hours and firefighters rescued a man sitting atop his flooded car on the metro Phoenix thoroughfare.

Arizona Department of Transportation spokesman Steve Elliott said pumps were overwhelmed by 3 inches of rain that fell within about a half-hour at an interchange where the freeway dips below street level.