Mountain Breeze - A wind pattern that develops during the night due to differential cooling on the mountain compared to nearby valleys. The mountain cools faster than the valleys in the evening. This cool, dense air blows down the mountainsides into the valleys. The opposite occurs during the day, which produces an upslope wind known as the valley breeze.

Equinox - Time of year when day and night are nearly equal in length. The equinoxes signal a transitional time of year. In the northern hemisphere, the autumnal equinox is the transition season that leads up to winter. Conversely, the vernal equinox is the transition season of spring that leads to summer. On the equator, the sun can be seen directly overhead at noon on the day of an equinox.

CAPE - An important term used to describe how unstable the atmosphere is. CAPE is an acronym for Convective Available Potential Energy. CAPE is a measure of potential energy in the atmosphere. The greater the CAPE is, the stronger a thunderstorm will be if one develops. The presence of CAPE alone does not mean thunderstorms will develop, as other factors must be overcome for the energy potential to be realized.

Anemometer - An instrument that measures wind speed. The strongest wind speed ever recorded by an anemometer was 253 mph during the passage of a cyclone on Barrow Island, Australia back in April of 1996.

Hectopascal - The standard measurement for atmospheric pressure now adopted by the World Meteorological Organization for global weather charts. The millibar is still however a commonly used unit for measuring pressure. Conveniently, millibars are actually equal to hectopascals. The global average for sea level pressure is 1013 hectopascals or millibars.

Stratopause - The boundary or transition layer between the stratosphere and mesosphere. The stratopause is located around 30 miles above the surface of the earth.

Nephophobia - The irrational fear of clouds. This is derived from the Greek word for clouds, which is nephos.