Tornado watches marked Arizona’s first since October 2010
Severe thunderstorms swept through northern and central Arizona overnight Tuesday and into Wednesday, bringing hail the size of golf balls, damaging wind gusts, tornado risks and possible flash flooding. The National Weather Service issued multiple warnings and encouraged people to seek shelter and stay away from windows as the storms moved through the state.
Damaging hail ranging from 2 to 3 inches (5 to 7.6 centimeters) pummeled roofs, shattered windows and dented cars. Strong winds toppled trees in Flagstaff and Mesa, with some landing on walls and carports.
Tornado watches were issued for multiple areas of Arizona, the first the state had seen since October 2010. The watches came as changing winds added the possibility of tornadoes to the hail and wind already produced by the storms.
Ryan Bernhart, a National Weather Service meteorologist in Flagstaff, said warm, moist air moving north fueled storms coming off the California coast. Changing winds can make storms spin, creating conditions for tornadoes, Bernhart said.
Bernhart described the combination as unusual for the region and the season. “This is very unusual for this area at this time of the year,” he said.
The wind damage extended into the Coconino National Forest northwest of Flagstaff, where a few dozen ponderosa pines taller than 30 feet (9 meters) fell. Bernhart emphasized the scale of the trees that toppled. “These are not small trees that are down,” he said. “These are pretty strong trees that had been knocked down.”
The greatest threat to the Phoenix metro area was heavy rainfall and flash flooding, said Mark O’Malley, a meteorologist at the National Weather Service office in Phoenix. O’Malley said the danger would peak that night and Thursday morning.