Thin wispy fiberous cloud at high altitudes composed of ice particles?

Question

Thin wispy fiberous cloud at high altitudes composed of ice particles?

Answer 1

Cirrus clouds are high-level clouds which form above 20,000 feet (6,000 meters) and are usually composed of ice crystals. High-level clouds are typically thin and white in appearance, but can create an array of colors when the sun is low on the horizon. Cirrus generally occur in fair weather and point in the direction of air movement at their elevation.

http://www.srh.noaa.gov/jetstream/synopt...

Answer 2

Cirrus.

Sometimes called "mares' tails".

Answer 3

Cirrus is the singular, Cirri is the plural.