Hail in Delaware County, Oklahoma

Strong to severe thunderstorms developed across eastern Oklahoma during the early evening of the 25th, north of a warm front near the Red River, as an upper level disturbance approached the region from the west. The atmosphere north of the warm front across eastern Oklahoma became moderately unstable during the afternoon and early evening, and the deep-layer wind shear was strong with the approach of the upper level disturbance. Some of the thunderstorms were able to develop into supercells due to the favorable combination of instability and wind shear. Large hail up to tennis ball size occurred with the strongest thunderstorms, as well as isolated damaging wind.