FARMERSBURG, Ind. (WTWO/WAWV) – Clouds.  They can be beautiful.  Threatening.  Producing snow, thunderstorms and tornadoes.  Lets take a look at the most common cloud types. Special clouds include contrails made by jets.  They’re clouds, because they’re made of water droplets condensed from water vapor in the jet exhaust. Contrails can provide information about moisture layers. Mammatus clouds consist of altocumulus, cirrus, cumulonimbus and other clouds with pouch-like shapes hanging out of the bottom.  Cold air in the clouds sinks, forming the pouches. This cloud tells us severe weather may be on the way. Orographic clouds are shaped by mountains or hills forcing air to move over or around them.  They can be formed by sea breezes and can appear as lines where two air masses meet. An early indicator for possible afternoon thunderstorms. Lenticular clouds are shaped like lenses or UFO’s.  Shaped by hilly terrain or the way air is rising over flat ground.  These offer no weather predictions.Low clouds include cumulus clouds.  Fluffy, white cotton balls.  Beautiful in sunsets and the many sizes and shapes can create some fun images.We call them fair weather clouds.Stratus clouds look like thin, white sheets.  So thin they seldom produce precipitation.  These can appear as fog in the mountains or hills. Fair, but gloomy. Cumulonimbus clouds grow on hots days as warm, wet air rises very high.  These appear to be towering. Watch out for rain, hail, and tornadoes.