Rain Shadow - A region that has a drier climate due to the existence of a mountain range nearby. In the US, the prevailing winds push weather systems from west to east. As these systems move into the mountains, much of the moisture in the system precipitates out, thereby leaving areas on the east side of the mountain range with little to no precipitation by the time the system moves in. This effect is evident in many areas downwind of any major mountain ranges in the western US.

Q Vectors - These vectors are calculated by meteorologists in order to find areas of the atmosphere with vertical ascent. They are an important tool because their interpretation allows meteorologists the ability to diagnose areas of lift in the vicinity of fronts as well as upper level jet streaks. Diagnosing lift is key to meteorologists because lift results in clouds and at times precipitation.

Cloud - Any visible mass of water droplets, ice crystals, or a mix of both that become suspended in the atmosphere. Fog is a cloud that forms at the ground, while cirrus clouds oftentimes form at around 40,000 feet.

Polar Vortex - The polar vortex is an area of low pressure that coincides with the pool of arctic air that encircles the North or South Pole. Each fall, the polar vortex begins to form due to decreasing daylight near the poles. By mid-winter it becomes more influential to the weather patterns in the mid-latitudes.

Lake Breeze/Sea Breeze - A sea or lake breeze develops due to temperature differences between the surface of the sea and land. Because water temperatures over a large body of water are more constant than land temperatures, a density gradient develops when the land heats up during the afternoon, thereby inducing a cool breeze that blows from the sea over the land. The opposite of a sea breeze is a land breeze. This occurs during calm nights when the land cools and becomes colder than the sea surface temperatures. A land breeze blows from the land out to sea.

Isobars - Isobars are lines on a weather map joining points that have the same air pressure at a given altitude. Isobars are typically drawn in for surface plots. When isobars are tightly packed, windy conditions can be expected.

Hydrometeor - Any product of condensation or deposition of atmospheric water vapor, whether formed in the free atmosphere or at the earth's surface. Sea spray blown into the air is also composed of hydrometeors. Raindrops, snowflakes, and all other types of precipitation qualify as hydrometeors.