Download
1 / 48
480 likes | 662 Views
High clouds. >23,000 ft. cirr- (“curl of hair”) ice crystals generally occur in fair weather and point in direction of air movement at their elevation. Cirrocumulus : clouds in long rows of puffy clouds; often precursor to precipitation. “mackerel sky”. cirrocumulus. Cirrostratus.
E N D
High clouds • >23,000 ft. • cirr- (“curl of hair”) • ice crystals • generally occur in fair weather and point in direction of air movement at their elevation
Cirrocumulus: clouds in long rows of puffy clouds; often precursor to precipitation
Cirrostratus • Broad layer of air lifted by large scale convergence; transparent enough to see sun or moon • “halo” may form from refraction of light by ice crystals • will thicken and lower if warm front is approaching
Middle Clouds • 6500-20,000 ft. • alto- • ice crystals and water droplets
Altocumulus • can be parallel bands or rounded masses; can distinguish from cirrocumulus because part of them is usually shaded • form by convection in an unstable layer aloft • may suggest an approaching cold front • Hold hand at arm’s length, clouds are thumbnail size
Altostratus • Absence of shadows • Sun or moon is bright spot behind clouds, no halo
Low Clouds • <6500 ft. • strat- • water droplets
stratocumulus • Low, lumpy layer of rounded masses, rolls, sometimes with clear sky between • Hold hand at arm’s length, clouds are fist-size
