Severe weather in Minco has brought hailstones as large as golf balls and is set to track into the Oklahoma City metro. The storm's core is expected to move over Union City and toward Mustang and Yukon, and the storm could drop tennis ball-sized hail. The severe storm also prompted a tornado warning for Grady, Oklahoma, Cleveland, Canadian and McClain counties until 7:15 p.m. KOCO 5 Field Meteorologist Michael Armstrong showed hail visibly bouncing off the street in front of First Alert Storm Command. The weather team has been certified Most Accurate Forecast in Oklahoma City for 13 consecutive years.