always changing shapes
giant thunderhead clouds
produce thunderstorms with lightning, hail, wind, or heavy rain
look thin, wispy, and feathery
tall, dark, and billowing
overcast
looks like cotton: fluffy tops with dark bottms
often seen in clear skies and mean fair weather
fog
highest cloud in the sky
thick blanket of gray layers
signal fair weather, but can turn into showers and thunderstorms
usually bring drizzle or light falling snow
made up of ice crystals
