Arizona Public Service Co. says at least 4,000 customers in Scottsdale have lost power due to outages related to thunderstorms that dumped heavy rain on parts of the metro area.
Intermittent heavy rain in the metro area has slowed traffic and pooled water on some roadways.
The state Department of Transportation said in a Twitter post that motorists should avoid an Interstate 17 off-ramp in Phoenix because several cars were stalled by standing water.
A flash flood advisory is in effect in the Phoenix area where rain slowed traffic during the tail end of the Friday morning commute.
The National Weather Service says the advisory will be in effect until 11 a.m. and that radar and rain gauges indicate that runoff from thunderstorms will cause running water in washes and pooling of water in low spots.