Cloud Types - Knowing the cloud types that you may see in the backcountry and the types of atmospheric conditions they indicate will help you to predict the weather more accurately.

High Clouds (20,000 ft)
	Cirrus Clouds - Cirrus clouds are characterized by high ice crystals, pumped high in the sky by a vortex, blown ahead by high winds. They generally bring good weather if winds are from W NW to N. Precipitation is likely within 20 to 30 hours if winds steady from NE E to S. They warn of a coming storm if coming from the southwest.
	Cirrostratus Clouds - Cirrostratus "halo" clouds are actually ice crystals that produce the "halo" effect. Precipitation is likely within 15 to 25 hours if winds steady from NE E to S, or sooner if winds SE to S. Other wind directions bring overcast skies.
	Cirrocumulus Clouds - Cirrocumulus clouds are characterized by high ice crystals. Precipitation is likely in 15-20 hours if wind NE to S. If found in early Summer A.M. skies, brings afternoon thunder showers. Other wind directions bring overcast skies.

Mid-level Clouds (6500 - 20,000 ft)
	Altostratus Clouds - Altostratus clouds make the sun seem to appear to be behind heavily frosted glass. Altostratus clouds are likely to bring precipitation within 10 to 15 hours if wind is steady NE to S. Other wind directions bring overcast skies.
	Altocumulus Clouds - Altocumulus clouds are a mixture of water and ice clouds. They are likely to bring precipitation within 15 to 20 hours if wind is steady NE to S. Other wind directions bring overcast skies.
	Cumulonimbus "Mamma" Clouds - Cumulonimbus mamma clouds are low to middle clouds that may follow severe weather. These clouds do not form tornadoes as often thought. They are, however, associated with severe wind squalls, hail, heavy precipitation, and thunderstorms. Often shaped like an anvil, these are also known as thunderheads.

Low-level Clouds (0 - 6500 ft)
	Stratus Clouds - Winds from NE to S may bring heavy precipitation. Other winds may only bring light drizzle or an overcast sky.
	Nimbostratus Clouds - Rain or snow clouds. Precipitation of long duration if winds from NE to S, or shorter duration if winds are from SW W to N.
	Stratocumulus Clouds - Stratocumulus clouds are an immediate indicator of bad weather from a sprinkle to heavy precipitation. If these clouds are at the head of a cold front, gusty winds or thunder showers may follow.
	Cumulus Clouds - Cumulus clouds are generally low clouds and known as "fair weather" clouds unless they begin to show vertical growth. If vertical development is shown, cumulonimbus or rain clouds can form and bring thunderstorms quickly.