Thunderstorm Definitions and Safety
According to the National Weather Service (NWS), a thunderstorm occurs when an
observer hears thunder, Radar observers use the intensity of the radar echo to distinguish
between rain showers and thunderstorms. Lightning detection networks routinely track
cloud-to-ground flashes, and therefore thunderstorms. Thunderstorms arise when clouds
develop sufficient upward motion and are cold enough to provide the ingredients (ice and supercooled water) to generate and separate electrical charges within the
cloud. The cumulonimbus cloud is the perfect lightning and
thunder factory, earning its nickname, "thunderhead."
Thunderstorms are like nature's heat pumps. At the very top of giant thunderstorms, air temperatures can sometimes drop to below -100
|Important Definitions You Should Know:|
|Watch: Conditions are favorable for the development of a severe weather event in or near the watch area. Prepare for the possibility of severe weather.||Warning: A severe weather event is imminent of occurring in the warned area. It is time to take action! Put preparedness plans into action.|
If a warning is issued
for your area you need to move immediately to a substantial building or
shelter. Stay away from windows. If a tornado warning is in
effect move to the lowest floor of your home. Go to an interior room
(such as a closet or bathroom) and cover your head and body.
Back to Thunderstorms and
Associated Weather Phenomena.
By definition, the National Weather Service classifies a thunderstorm as severe if it contains hail of three-quarter inches or larger, and/or wind gusts of 58 mph or higher, and/or a tornado. Severe thunderstorm watches, meaning conditions are suitable for severe thunderstorm development during the next several hours, are issued for areas several hundred miles on a side by the NWS Storm Prediction Center in Norman, Oklahoma. A severe thunderstorm warning is issued by the local NWS office, usually for a county or several counties over an hour or so, based on spotter reports or radar indications of conditions exceeding severe levels. If there is a distinct threat or actual observation of a tornado, a tornado warning is issued. Tornadic storms also produce hail, downbursts, and lightning, and those hazards should be likewise considered.
Are you interested in helping the NWS in
Riverton fulfill its mission of protecting lives and property across western
and central Wyoming? Check out our
spotter training schedule and join the team. Reports from certified
spotters can be of immense help in making warning decisions. These
spotters are also eligible to participate in as an
Martner, Brooks E. Wyoming Climate Atlas, University of Nebraska Press 1986.
Lyons, Walter A. Ph.D. The Handy Weather Answer Book,Visible Ink Press, 1997
If a warning is issued for your area you need to move immediately to a substantial building or shelter. Stay away from windows. If a tornado warning is in effect move to the lowest floor of your home. Go to an interior room (such as a closet or bathroom) and cover your head and body.
Back to Thunderstorms and Associated Weather Phenomena.