Extremely Foggy

It doesn't generally snow in California's Central Valley in winter, and it doesn't usually get cold enough for bridges to ice up. The winter hazard here is Tule Fog, which forms on still, cold nights. The layer isn't very thick - the light of a full moon has no trouble filtering through to the ground - but visibility can be extremely limited. On this December 15th night, car and train headlights materialized out of the fog less than 600 feet away, and dark objects were invisible less than 100 feet away. The 45 second time exposure that produced this image brings out details that were imperceptable at the time, such as the fence line in the distance. Through this soup, the intermediate signals at Cannon, CA near Suisun-Fairfield project their beams. Hope the crews have enough time to see them before they fly by.