A towering wall of dust swept across the Phoenix metropolitan area late Monday, turning daylight to near darkness and cutting visibility to a quarter-mile. The haboob, generated by collapsing thunderstorms, was followed by heavy rain and lightning that rattled much of central Arizona. The storm knocked out electricity to roughly 39,000 customers statewide, according to PowerOutage.us, with outages peaking near 57,000 earlier in the evening. Wind gusts reached 67 mph in Chandler, toppling trees and darkening traffic signals in several East Valley communities. Phoenix Sky Harbor International Airport halted departures and arrivals under a Federal Aviation Administration ground stop that lasted until 6:30 p.m. Two flights were canceled, 82 were delayed and Allegiant Flight 2285 was diverted to Las Vegas. Once operations resumed, most flights were running 15-to-30 minutes late. The National Weather Service issued multiple dust-storm and severe-thunderstorm warnings across Maricopa and Pinal counties, while state transportation officials urged motorists to “Pull Aside, Stay Alive.” Forecasters put rain odds for the metro area at 40% on Tuesday before drier conditions return later in the week.