2. Cirrus, delicate, not increasing, abundant but not forming a continuous 



layer ^0 



3. Cirrus of anvil clouds, usually dense 30 



4. Cirrus, increasing, generally in the form of hooks ending in a point or 



in a small tuft -- ^^ 



5. Cirrus (often in polar bands) or cirrostratus advancing over the sky 



but not more tlian 45° above the horizon 30 



6. Cirrus (often in polar bands) or cirrostratus advancing over the sky and 



more tlian 45° above the horizon 31 



7. Veil of cirrostratus ccnering the whole sky 31 



8. Cirrostratus not increasing and not covering the whole sky 31 



9. Cirrocumulus predominating, associated with a small quantity of cirrus, 31 



20 



