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.

Smog - The first definition of smog was a mixture of smoke and fog in the atmosphere which reduces visibility. Over time smog has now changed its meaning to restricted visibility due to pollution emitted from human activities. A type of smog known as photochemical smog, common to heavily populated areas, forms when UV light from the sun reacts with low level pollutants such as nitrogen oxides. On hot days this reaction can create ozone gas at the surface which is dangerous to humans.

Exosphere - The Exosphere is the outermost layer of the atmosphere. It extends from the top of the thermosphere and is 6,200 miles thick. In this layer, atoms and molecules escape into space and satellites orbit the earth. Some scientists place the outer reaches of the exosphere about 120,000 miles from the earths surface, making it near the half way point to the moon.

Insolation - Insolation is the amount of solar radiation that reaches the earth and the atmosphere. The amount of insolation at a specific location varies due to the length of day and the angle of the sun. During the winter in the northern hemisphere, the shorter days compiled with the lower angle of the sun results in much lower insolation compared to what is received during the summer months.