Shelf Cloud - Also known as a roll cloud. A low, horizontal, sometimes wedge-shaped cloud formation associated with the leading edge of a thunderstorm's outflow winds or gust front. Shelf clouds normally stretch across the entire horizon as an organized line of storms approaches. When a shelf cloud is observed, prepare for a quick increase in winds. A severe line of storms can produce shelf clouds that indicate incoming straight-line winds of over 60 mph.

Mammatus Clouds - Cloud cover that has numerous rounded, smooth, sack-like protrusions hanging from the underside. Mammatus clouds are most commonly found in an anvil of a thunderstorm. Mammatus clouds can accompany severe thunderstorms, but they also occur often with non-severe thunderstorm activity.

Anabatic - refers to a rising wind flow, oftentimes climbing up a hill or mountainside. Anabatic winds are driven by localized heating at the surface, which creates a rising current of air due to the lower density that warmer air has.

Synoptic Scale - In meteorology this refers to the study of large scale systems that develop in the atmosphere. Major cyclones and their associated fronts are a commonly studied feature in synoptic meteorology. In order to be on the synoptic scale, a system must stretch across a distance of at least 600 miles.

Avalanche - A large mass of rapidly moving snow down a steep mountain slope. Most avalanches are triggered by the people that become victim to them. On average, around 150 people are killed by avalanches each year.

Bermuda high - A semi-permanent subtropical high over the North Atlantic. Can contribute to excessive heat and humidity in the southern and eastern US. The placement of this high is also the main steering force for hurricanes that develop in the Atlantic.

Doppler Effect - The shift in frequency that occurs when an object goes from moving towards an observer to away from an observer. Everyone has heard this when a police car drives by. As the police car is approaching, the siren will have a high pitch. Then when the police car begins moving away from you the pitch of the siren lowers. This effect is what weather radars use to calculate velocity.