This document summarizes different mechanisms for cloud and precipitation formation. It discusses how adiabatic temperature changes cause air to cool and condense as it rises upward or expands. It also describes how orographic lifting can cause the windward sides of mountains to receive more rain, while rain shadows form on the leeward sides. Finally, it mentions how frontal wedging occurs when warm and cold air masses collide at a front.

1. Clouds and precipitation
By: Nate Mann

2. Adiabatic temperature changes and
expansion and cooling
• This happens when air is compressed or
allowed to expand
• As you travel up ward the atmospheric
pressure decreases
• If a parcel of air rises high enough it will cool
to its dew point
http://www.bio-
world.com/productinfo/4_71_557_730/4501/
Advanced-Thermometer-with-RS-Output.html

3. Orographic lifting
• Rainiest places are mostly on wind ward sides of
mountains
• Rain shadow deserts can occur on lee ward sides
of mountains
• If air descends it cools adiabatically
http://www.examiner.com/outdoorsman-in-salt-
lake-city/understanding-why-utah-has-the-
greatest-snow-on-earth-part-1-orographic-lifting

4. Frontal wedge
• A mass of cool and warm air collide making a
front
• Whether fronts are associated with specific
storm systems
http://www.geo.hunter.cuny.edu/~tbw/wc.note
s/4.moisture.atm.stability/frontal_wedging.ht
m