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, 2001) […]