PHOENIX -- A major Pacific storm is moving into Arizona with heavy rain spreading across the greater Phoenix area and heavy snow pounding the higher elevations of the state.

Waves of rain will continue to move through the Valley until Tuesday morning, with the heaviest rain falling on the higher terrain north and east of Phoenix. Places such as Black Canyon City, Carefree, Cave Creek and Globe could end up with more than 2 inches of rain by midday Tuesday.

The National Weather Service has issued a flash flood watch for Maricopa County during the overnight hours due to the anticipated heavy rainfall.

Meanwhile, the Northern, Mogollon Rim and White mountains are bracing for total snow accumulations of 12-24 inches above 6,000-7,000 feet. Strong winds accompanying the snow may result in blizzard conditions along Interstate 40 in the Flagstaff area, where a blizzard warning is in effect through Tuesday morning.

The storm will quickly clear out of most of the state during the day Tuesday with sunshine returning to the Valley by afternoon. Temperatures will remain chilly with a forecast high in Phoenix of 58 degrees.