Highway 52 Storm Cell – Two and Half Minutes Lightning Strikes. This is Lightning thunderstorm east of hwy287 on hwy 52, Boulder County ,Colorado. 08-15-2010. This is a layered image equal to about a 2 1/2 minute exposure. Lightning Facts: Approximately 494,000 cloud to ground lightning flashes occur in Colorado every year. Colorado ranks 26th in the nation (Ron Holle, Global Atmospherics, quoted from the Rocky Mountain News, 30th June, […] […]