a close up of clouds in the sky

Mount Tam's fog wave. This day's fog is a bit thicker than those days when you can kind of see the road leading up to the mountain (Panoramic Highway). But the shape of the fog looks quite interesting still. Fog Wave here happens during the summer. As the valleys begin to cool off around 3-4 PM, the cold Pacific air gets drawn to the interior. Seas and rivers of fog cascade down the Coast Range North and South of San Francisco.