Sferics - Radio waves that are produced in the atmosphere by lightning strikes. When lightning strikes, a disturbance in the electric field occurs, which results in a radio wave being emitted. This concept is used in ground-based lightning detection systems.

Trowal - An acronym for "trough of warm air aloft." It is usually a similar type of frontal structure as is found in the vicinity of an occluded frontal boundary. Organized areas of precipitation can be expected in this region.

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.

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

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.

Trowal - An acronym for "trough of warm air aloft." It is usually a similar type of frontal structure as is found in the vicinity of an occluded frontal boundary. Organized areas of precipitation can be expected in this region.

Severe Thunderstorm Warning - One is issued when either a severe thunderstorm is indicated by the WSR-88D radar imagery or via spotter reports. In order for a thunderstorm to be considered severe one or more of the following parameters must be reached: quarter sized diameter hail or larger, 58 mph or greater winds, isolated tornadoes. When a severe thunderstorm approaches people in the affected area should seek shelter immediately.