Orographic Lifting - The forced rising of air that occurs when winds run into a mountain or any area with notably higher terrain. When moist air pushes against and rises up a mountain, the air cools adiabatically, resulting in clouds and precipitation. This is the reason why higher elevations in the mountains will see greater amounts of precipitation.

Windward - The side of an object facing the wind. For example, if the wind is blowing in from the west, an object's west facing side would be the windward side. Conversely, the east side of the object would be the leeward side.

Rain - Precipitation that falls to earth in liquid drops that are greater than 0.5 mm in diameter. Liquid drops that are smaller than .5 mm are categorized as drizzle. The largest raindrop that has ever been measured occurred in September of 1995 in Brazil as well as in July of 1999 in the Marshall Islands. At both these sites the raindrops were measured at a whopping 8.6 mm (.338 in) diameter!

Freezing Drizzle - A drizzle that falls as a liquid but then freezes into a light glaze or rime upon contact with the cold ground. Freezing drizzle is different than freezing rain because it accumulates at a much slower rate. Freezing drizzle tends to be localized and not widespread, which makes it more difficult to predict.

Greenhouse effect - The term that describes how the Earth receives solar radiation and how it is essentially trapped in the Earth's atmosphere. The incoming solar radiation is absorbed at the surface and then radiates back up to space in the form of infrared radiation. However, the greenhouse gases in the atmosphere absorb some of this outgoing radiation and then re-radiate it back down to the surface. The higher the concentration of greenhouse gases, the more magnified this effect becomes.

Terminal Velocity - The maximum velocity that can be reached for a falling object. Terminal velocity is reached when the downward force of gravity and the upward force of air resistance become equal to each other. An object's fall speed becomes constant once it reaches terminal velocity. The terminal velocity of most raindrops is around 20 mph, while large hailstones have terminal velocities that can exceed 100 mph!

Drought - An extended period of abnormally dry weather that creates shortfalls in the amount of surface and/or subsurface water. Droughts have major impacts on agriculture and can have major socioeconomic consequences as well.