Thick, pea soup fog. Blue skies with whipped cream clouds. A hazy blanket above the central valley. Dark nimbus towers with rolling thunder and flashing bolts. High elevation cirrus ice clouds and mountain-influenced UFO and fishbone clouds. Our summer vacation included cloud-watching across California.coastal fog

We road tripped across our state west-to-east, coast-to-the Eastern Sierra. As we traveled, we watched the diverse California landscape changing and observed how the land affects the clouds; how the Earth and sky are connected.

We awoke in the cool fog of the Mendocino coast. Light drizzle dampened the tent as we packed up to head inland. Living on the coast, we are used to the fog – especially in the summer – when the warm, moist air flows over the cold ocean surface, the air is cooled from below, and condenses into liquid fog droplets.

Traveling east on highway 20, climbing over the coastal range, we quickly left the fog. Our cloud observations switched to watching buoyant blobs of fluffy white cumulous clouds appear invisibly over the highest peaks. As the sun warms the rolling hills, the air rises, meets the cooler air above, and the water vapor condenses into liquid droplets. These transforming white puffs are a parent’s gift on a road trip – great for inspiring stories in the sky.

cumulous cloudsWe reached the flat expanse of the central valley, grateful for a blanket of stratus clouds above that filtered out some the hot August sun. We passed fields and tractors stirring up dust, and talked about how water vapor attaches to small particles – called nuclei – and tiny liquid droplets form around each dust particle to build clouds.

Climbing into the Sierra foothills, the sky cleared to a celeste blue, with scattered cumulous animals transforming on the horizon. Over the pass, into the afternoon, the sky changed again. On the north shore of Lake Tahoe, growing cumulous turrets became thunderhead nimbus clouds. Lightning and pounding rain convinced us it was not a good time for swimming and kayaking on the lake.

The high country of the Eastern Sierra Nevada provided the grand finale for our cloud-watching travels. Cirrus feather-clouds made of ice crystals dominated the sky. UFO-shaped “lenticular” altocumulous clouds and fishbone “vertebratus” cirrus formed from the mountain influence. Contrails from jets created long-lasting spider web patterns.

At the end of the trip, we circled back to Santa Cruz, comforted by the coastal fog and morning drizzles that nourish the redwoods and keep us cool.