If you read the SPC convective outlooks leading up to that event, you will notice several interesting things:
1.) SPC went 30% probabilistic on D3. That's anomalous.
2.) The Day 3 and Day 2 mentioned negative tilted upper low. . .in June. Red flag that we're dealing with a potent event.
3.) We closed well on this event: dynamics and instability. Had we had even an hour or two of legitimate, full sun then it would've been a top 10 tornado day in this region. To me, that event is the benchmark for non-tropical tornado days in these parts.