Courtesy of VAISALA

Lightning seemed to dominate the Tucson landscape last night. That's why today I contacted local lightning expert Ron Holle to find out more about it.

Holle works with VAISALA, which owns and operates the U.S. National Lightning Detection Network. From its Tucson offices, the company's network of sensors records in real-time every lightning stroke in the continental United States.

According to Holle, there were 7,522 cloud-to-ground strokes of lightning Sunday in the map's display area. He explains strokes are not the same as lightning flashes. In fact, there are several strokes in a single flash of lightning.

The map's strokes are color-coded by time, starting at noon and continuing through midnight. The majority of yesterday's strokes — 3,961 of them — are depicted in light green on this map, meaning they occurred between 6 p.m. and 8 p.m.

To learn more about lightning, check out this chat Holle had with Arizona Daily Star readers earlier this summer.