Biblical storm hits region as golf ball-sized hail destroy homes and seven tornado warnings issued

Hailstones the size of golf balls and destructive wind gusts battered northern and central Arizona, United States in an unusual storm sweeping through. And now it is expected to bring tornado threats and potential flash flooding. The National Weather Service issued numerous warnings as severe thunderstorms travelled across the state overnight Tuesday and into Wednesday, urging residents to take shelter and stay clear of windows as damaging two to three-inch (5-7.6-centimetre) hail struck the region. Hailstones hammered people's roofs, smashed windows and dented vehicles. Tornado watches were declared for several areas - the first the state has experienced since October 2010. Warm, humid air pushing north is fuelling storms rolling in off the California coast. Shifting winds can cause them to rotate, creating the conditions for tornadoes, explained Ryan Bernhart, a National Weather Service meteorologist in Flagstaff. "This is very unusual for this area at this time of the year," Bernhart said. Powerful winds brought down trees in Flagstaff and Mesa, with some crashing onto walls and carports. Several dozen ponderosa pines over 30 feet (9 metres) tall collapsed in the Coconino National Forest, northwest of Flagstaff. "These are not small trees that are down," Bernhart said. "These are pretty strong trees that had been knocked down." The biggest danger to the Phoenix metro area is intense rainfall and flash flooding tonight and Thursday morning, said Mark O'Malley, a meteorologist at the National Weather Service office in Phoenix. As a result, seven tornado warnings have been issued, with NWS reps telling local media: "We typically issue a tornado warning somewhere in northern AZ just about every year, but today we’ve already issued seven, which is pretty rare."