PHOENIX, Arizona — Rain from monsoon storms overwhelmed parts of Flagstaff on Sunday. Also, there was a possibility of more flooding on Monday.

According to the Weather Channel, between 1½ and 2½ inches of rain fell in about an hour, trapping vehicles on roads and blowing out power to traffic lights.

A flash flood warning went into effect that lasted through the evening. The downpour swelled the banks of the Agua Fria River and prompted a flash flood warning in Black Canyon City, less than 13 miles from the Maricopa County line.

A shelter was opened by the Red Cross at Sinagua Middle School and drivers on State Route 89A also faced weather-related delays.

Down the road Monday, light rain fell on Phoenix during the early commuter rush hours. There was a possibility of thunderstorms in the evening, the National Weather Service said.

The high in the state’s capital was expected to reach 104 degrees under mostly cloudy skies.

Temperatures are expected to be higher as the week goes on — by Saturday it could be as hot as 109 degrees. On Sunday it might be 112 degrees.

Last week, the Valley had 3 days of monsoon storms.