Monsoon thunderstorms swept across the Phoenix metropolitan area on Thursday night, cutting electricity to thousands of customers and turning major roads into flood zones. The National Weather Service reported localized rainfall of more than half an inch in Scottsdale and Sun City West, with downburst winds reaching 40–50 mph. By late evening, standing water up to two feet deep was reported along Interstate 17 in the North-North-East Valley, prompting officials to warn motorists to pull aside if necessary and to avoid water-covered roadways. The weather agency continued to track storms producing additional downpours across Surprise, Apache Junction and surrounding communities. Severe weather began earlier in the day when the National Weather Service posted a series of severe-thunderstorm and flood advisories for Yavapai County, followed by flash-flood warnings for Gila County and for parts of Phoenix’s north and east suburbs that remained in effect until after midnight. A separate flash-flood watch was issued for Friday for the Grand Canyon area, Marble and Glen Canyons—including recent wildfire burn scars—because of the potential for debris flows. Forecasters expect another round of storms Friday evening, maintaining an elevated risk of flash flooding across central and northern Arizona. Authorities urged residents to monitor updated forecasts, secure outdoor power sources and avoid driving through flooded washes and underpasses.