Weather Alerts for New York

This map shows recent moisture content over North America. Bright and colored areas show high moisture (ie, clouds); brown indicates very little moisture present; black indicates no moisture.

Weather Topic: What are Altostratus Clouds?

Home - Education - Cloud Types - Altostratus Clouds

Next Topic: Cirrocumulus Clouds

Altostratus clouds form at mid to high-level altitudes (between 2 and 7 km) and are created by a warm, stable air mass which causes water vapor to condense as it rise through the atmosphere. Usually altostratus clouds are featureless sheets characterized by a uniform color.

In some cases, wind punching through the cloud formation may give it a waved appearance, called altostratus undulatus. Altostratus clouds are commonly seen with other cloud formations accompanying them.

Next Topic: Cirrocumulus Clouds

Weather Topic: What are Cirrostratus Clouds?

Home - Education - Cloud Types - Cirrostratus Clouds

Next Topic: Cirrus Clouds

Cirrostratus clouds are high, thin clouds that form above 20,000 feet and are made mostly of ice crystals. They sometimes look like giant feathers, horse tails, or curls of hair in the sky. These clouds are pushed by the jet stream and can move at high speeds reaching 100 mph.

What do they indicate?
They indicate that a precipitation is likely within 24 hours.

Next Topic: Cirrus Clouds