Northwest Cloud formations Northwest Cloud formations Geology 252: The Earth and its Weather Ron Kleinknecht
High Clouds (Cirrus) C H Etymology : Latin, Tendril, flexible appendage Height: Above 10,000 ft. (3 km) to ~ 60,000 ft. (18 km). Tropopause Ice crystals Forms: –mares tails, hooks, filaments & strands –cirrofractus –cirrostratus –cirrocumulus (mackerel sky)
Mares’ tails over Whistler
Cirrus with strands, filaments and hooks
Cirrus with more strands and filaments
Cirrus (Stratus?)
Sun Dog (parahelia) Through Cirrostratus
Sundog in Perspective
Cirrocumulus (Mackerel Sky)
Cirrus and Stratus at Sunset
Alto, (high) mid- level clouds (Cm) Height: Between 6,500 ft. (2 km) and 25,000 ft. (8 km) Forms: –Altocumulus –Altostratus
Altocumulus
Altostratus and Cumulus Congestus over Orcas Island
Winter Altostratus over South Bellingham
Layers of Cirrus, Altostratus and ?
Low Clouds (C L ) Height: ground to 6,500 ft. (2 km) Forms: –Fog –cumulus –stratus –Nimbostratus (rain) –cumulonimbus (rain/storm) Base starts low but can develop up to tropopause
October Cumulus with Moderate Vertical Development
Dissipating Cumulonimbus
Summer Stratocumulus July 2001
Late Summer Stratus with Fog Lifting
Stratocumulus over the Bay at Summer Sunset July 2001
Altocumulus at night: Sailors’ delight or warning?
Where is the Virga?
Weather Dragons Come Out
Looking for the green flash