Tornado Watch Definition Geography

The worst-hit region in the United States, called „Tornado Alley,” includes the Great Plains states of Kansas, Nebraska, and the Dakotas, as well as parts of Texas. Large-scale weather tends to converge in this region, making tornadoes more likely. Even so, „we still don`t know why some thunderstorms cause tornadoes and others don`t,” tornado chaser Tim Samaras said in early 2013. Samaras was a scientist and member of National Geographic who was killed by a tornado on May 31, 2013 in El Reno, Oklahoma. (Read „The Last Chase” in National Geographic magazine.) Brooks adds, „It`s not entirely clear that increasing tornado turnaround times [forecasts] will benefit the public, because we don`t know how people will react to this information.” Many people, for example, ignore the current tornado watches because they think the threat is unlikely. A tornado is a rapidly rotating column of air under a storm cloud. The term is believed to come from the Spanish tronada, which means thunderstorm. However, alternative etymologies have been derived from various Spanish and French words meaning „to turn”. Common names for a tornado are twister and cloud funnel. The biblical „whirlwind” was probably a tornado. In situations where the CPS has identified a high „high risk” or „moderate risk” of strong convective storms in and around the observation area, the term „particularly hazardous situation” (PDS) may be included in the monitoring product to emphasize the high confidence of forecasters that atmospheric conditions are the development of multiple strong to violent tornadoes (rated EF2-EF5 on the enhanced Fujita scale). support significant damage or outright destruction of property and serious injury or death caused by high winds and projectile debris, as well as the possibility of destructive straight winds and hail from mother supercells. (Tornadoes that occur in these situations can develop during the storm`s maturation phase as part of a typical mesocyclonic tornadogenesis at low levels or by accelerated mesocyclonic maturation generated early in thunderstorm development from sufficient wind shear and very high convective potential energy values [CAPE].) [6] [7] PDS tornado clocks – which account for ~3% of all tornado clocks per year in the United States based on SPC monitoring averages between 1996 and 2005 – generally indicate the likelihood of a major tornado outbreak, although they can be issued when there is a significant threat of isolated intense tornadoes.

The SPC (then National Severe Storms Forecast Center) devised the word PDS for use in Tornado watches in 1981; SPC and the National Weather Service have since applied it to other watches and warnings (including tornado warnings, severe weather warnings and warnings, flash flood warnings and red flag warnings) to highlight an exceptionally high risk to life and property. [6] [8] A tornado clock (SAME code: TOA) is a monitoring product of severe weather events issued by national weather forecasting agencies when weather conditions are favorable for the development of severe thunderstorms that can produce tornadoes. [1] In addition to the potential for tornado development, thunderstorms that develop in the viewing area may contain hail, straight winds, intense rain and/or flooding, which pose a similar risk of damage to the associated tornado hazard. A tornado watch does not mean that a tornado is active or will occur, only that favorable conditions increase the likelihood of such an event. A watch should not be confused with a tornado warning. A tornado clock indicates that atmospheric conditions observed in and near the viewing area have created a significant risk to the development and intensification of severe convective thunderstorms that can create tornadoes and are typically emitted before severe weather begins. If severe weather did occur, a severe weather or tornado warning would be issued. Residents and travellers in the guard area are advised to take safety precautions immediately prior to the arrival of storms. Tornado monitoring is not necessary to issue an alert.

Tornado warnings are sometimes issued when a tornado clock is not active (i.e., when a severe thunderstorm wake is active or when tornado development conditions are not expected to be large enough to require monitoring), when a severe thunderstorm has a confirmed tornado or has developed a strong rotation. A tornado clock may replace an existing severe thunderstorm clock, if not part of it, if the conditions initially thought to be slightly conducive to tornado development have evolved to allow for a greater risk of tornado formation.

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