Moore, OK hail storm history

What the National Weather Service wrote

A severe weather outbreak impacted portions of central and eastern Oklahoma, as well as western-north Texas, on the 19th and into the 20th. This marked the third and final day of a multi-day severe weather sequence driven by a strong upper-level system across the Plains. The 19th featured multiple waves of supercell thunderstorms from the late morning through late evening, with the majority of activity posing a threat for large to very large hail and occasional wind damage. While three tornadoes also occurred across the WFO Norman Forecast Area, generally weak low-level wind shear precluded a greater concern for tornadoes during the episode, despite a favorable (supercell) storm mode along with strong instability and deep-layer wind shear. Flooding also became prevalent across southeastern Oklahoma due to repeated rounds of heavy thunderstorm activity over several hours.