Overshooting Top Detections Identify Period of Frequent Severe Weather 5/19/2010

The overshooting top (OT) detection product detected a period of frequent severe weather reports for the 19 May 2010 event. Initially the cloud top brightness temperatures were too warm (> 217.5 K) for the algorithm to detect OT signatures between the time of the first reported tornado at 2028 UTC and 2210 UTC. Our first OT detection occurred at 2210 UTC and these continued throughout the duration of the severe weather event across Oklahoma. Though it may have seemed to the forecasters here at the HWT that the OT product did not have much value over radar based severe storm signals, 31 of the 37 severe storm reports in Oklahoma occurred on or after 2210 UTC. See the graphic below for an accumulated plot of OT detections from 12UTC on the 19th to 12 UTC on the 20th.