Tropical Storm Rosa neared Mexico's Baja California Peninsula on Monday, spreading heavy rains that were projected to extend into a drenching of the U.S. Southwest, including Arizona.
FULL FORECAST: Track latest storm, rainfall expectations
How much rain will Arizona see?
The U.S. National Hurricane Center said the center of Rosa, which was a hurricane until late Sunday, should hit Baja California and Sonora state late Monday, bringing 3 to 6 inches of rain.
It's then expected to move quickly northwestward as it weakens, bringing 2 to 4 inches of rain to central and southern Arizona and 1 to 2 inches to the rest of the desert Southwest, Central Rockies and Great Basin. Some isolated areas might be more.
LIVE RADAR: Track storm activity around Arizona
Rosa had maximum sustained winds of 45 mph early Monday and was centered about 90 miles west-southwest of Punta Eugenia in Mexico. It was heading north-northeast at 12 mph.
Watches and warnings
The National Weather Service earlier announced flash flood watches through Wednesday for areas including southern Nevada, southeastern California, southwestern and central Utah and the western two-thirds of Arizona.
Forecasts call for heavy rainfall in the watch areas, which include Las Vegas, Phoenix and Salt Lake City, with possible flooding in slot canyons and normally dry washes and a potential for landslides and debris flows from recent wildfire burn scars.
Parts of southern Arizona, including Yuma, saw major flooding as early as Sunday as Rosa began moving in.
Meanwhile, Tropical Storm Sergio was growing in the Pacific and could become a hurricane force Monday, though it posed no immediate threat to land.
Tropical systems in Arizona
Arizona has had about 10 tropical systems get within a couple hundred miles of the Valley since the 1960s.
Remnant moisture from Tropical Storm Norbert was the last major tropical system to impact the Valley, with record rainfall in September 2014.
MAP: Where to find sand and bags for Valley storm flooding
That system left hundreds of homes flooded and cars submerged on our freeways.
