Civil Dawn - The time of morning at which the sun is 6 degrees below the horizon. At this time, there is enough light for objects to be distinguishable and for outdoor activities to commence.

Bolide - Is an especially brilliant meteor that explodes upon reaching the earth's atmosphere. They are brighter than magnitude -4, which is about the same magnitude of the planet Venus.

Fahrenheit - Temperature scale developed by the German-born scientist Daniel Gabriel Fahrenheit. The Fahrenheit scale bases the boiling point of water at 212 and the freezing point at 32. The U.S. and a few Caribbean countries still use the Fahrenheit scale. All other countries use the Celcius scale.

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.

Noctilucent Clouds - These are a type of cloud that is extremely rare and found very high in the atmosphere. The base of these clouds is typically around 200,000 feet. They are seen as wavy, thin, bluish-white clouds and are best seen at twilight in polar latitudes. The word Noctilucent is derived from the latin word that means "night-shining.'

Hard Freeze - A hard freeze occurs When temperatures fall below 28 degrees for a period of four or more hours. A hard freeze kills most vegetation and marks the official end of the growing season.

Derecho - A widespread and usually fast-moving complex of thunderstorms that produce damaging straight-line winds. These systems are long lived, as the swath of wind damage associated with them extends for hundreds of miles. Wind gusts can range from 60 to over 100 mph in a derecho.