Norman, OK hail storm history

What the National Weather Service wrote

Multiple rounds of severe weather produced reports of thunderstorm wind, large hail and flash flooding across central into southern Oklahoma on the 4th into the early morning hours of the 5th. The first convective episode began just after midnight on the 4th when a (strong) warm air advection pattern commenced across central into southern Oklahoma. Initial activity slowly organized into a line of storms, progressing across central and southern Oklahoma. Reports of small hail and thunderstorm wind damage occurred. Localized heavy rainfall from the southern Oklahoma City Metropolitan area into southeast Oklahoma also fostered flash flooding. A briefly organized thunderstorm occurred behind this complex (across the Oklahoma City Metropolitan area) and produced a few reports of large hail towards sunrise. By the evening, a second round of organized convection developed across the eastern two-thirds of Oklahoma, fostered by the approach of a more substantial upper wave (i.e., increased deep-layer wind shear combined with continued strong instability). Additional damaging wind and large hail reports were observed with this round, along with renewed concern for localized flash flooding, especially across the southern suburbs of the Oklahoma City Metropolitan area.