Many thunderstorms form under those conditions, which never come close to producing tornadoes. Even when the large-scale environment is quite favorable for tornadoes, not every storm spawns one. Instead, tornadoes form via complicated storm-scale processes which depend on the interaction of the storm's internal dynamical structure including its forward and rear flank gust fronts see below with the influx of buoyant, sheared air immediately around and under the rotating updraft mesocyclone within the storm.
In fact, recent theories suggest that the temperature and moisture characteristics of the rear flank downdraft of a supercell are very important in spawning a tornado. Although prediction of the exact location and intensity of tornadoes is difficult, atmospheric conditions associated with the formation of the parent severe storms often are well-forecast.
Once thunderstorms develop, the National Weather Service's WSRD Doppler radar is used to evaluate severe weather and tornadic radar signatures in order to make short-term predictions of tornado occurrence. If a tornado is suspected, a tornado warning is issued for the affected area. However, while Doppler radar can interrogate severe storms very well, it cannot always detect the small-scale processes that actually lead to tornadogenesis.
Therefore, trained storm spotters, public officials, and the media also are vital in the warning process by gathering, relaying, and disseminating pertinent observed weather information. This partnership facilitates the proper detection and warning of tornadoes for the general public.
Damage results from the strong winds within a tornado. The degree of damage and speed of these winds vary widely, depending on the intensity of the tornado.
The Fujita Scale is designed to assess damage produced by tornadoes, then estimate associated wind speeds by assigning an "F" rating. The scale ranges from F0 weak tornado with winds up to 72 mph to F5 very violent tornado with winds around mph. The vast majority of tornadoes range from F0-F3. All tornadoes produce damage, but the most violent ones can cause automobiles to become airborne, rip homes to shreds, and turn broken glass and other debris into lethal missiles.
The biggest tornado threat to human beings is from flying debris in the wind. It is important to note that straight-line winds from a thunderstorm can do damage similar to an F0 or F1 tornado.
What is the smallest, largest, and average size? Tornadoes can vary significantly in size and intensity. Thus, the easiest way to answer this question is to assess the size of the damage path. However, the term "average" can be misleading, since the majority of tornadoes are small compared to the infrequent large events. With this said, the typical tornado damage path is about one or two miles, with a width of around 50 yards.
The largest tornado path widths can exceed one mile, while the smallest widths can be less than 10 yards. In addition, nine of the 10 worst individual tornadoes were spawned during April, May or June. The reason why tornadoes are more common in spring compared to other months is because the required atmospheric ingredients come together more often this time of year. Tornado outbreaks occur when a storm system propelled by a strong, southward dip in the jet stream punches into the Plains, Midwest or South.
This is accompanied by warm and humid air flowing northward out of the Gulf of Mexico. The jet stream provides deep wind shear, or changing wind speed and direction with height, supportive of rotating supercell thunderstorms. If wind shear is particularly strong in the first few thousand feet near the surface, these supercells would more likely produce tornadoes. Historically, the greatest threat of tornadic thunderstorms has migrated from the South into parts of the Plains and Midwest as we advance through April, May and June.
For example, the potential for tornadoes in the South is much lower in June compared to April. Although moisture is abundant across the southern region in late spring, the strong jet stream needed to help make conditions favorable for tornadic thunderstorms moves northward toward the Canadian border. Daily 26 Today. Tornado Alley gets so many tornadoes because the weather conditions in the area are favorable for tornado development.
The conditions are:. Tornado Alley , while not a geographically defined region, is a colloquial term used by the media to describe the area in the United States where the most violent tornadoes frequently occur.
Fawbush and Captain Robert C. Miller in their study of weather events in Texas, Colorado, and Nebraska. Other scientists and researchers call the same area the Great Plains tornado belt, while climatologists and storm chasers also recognize that tornadoes are prevalent in the area. The nickname Tornado Alley gained more media traction when it became a headline of a New York Times article on recent tornado activity in the country.
The exact boundaries of Tornado Alley are not clearly defined, as they vary according to the frequency, intensity, and events per unit area.
But generally, the area spans across the south-central United States, between the Rocky Mountains and the Appalachian Mountains. The states that make up Tornado Alley primarily include:. The data is based on tornado occurrences within a year period from to Below is a table with the top 10 US states with the highest average number of tornadoes recorded. After you read it, keep scrolling for some interesting information about tornadoes that affected each of these 10 states.
This may explain why it experiences the most tornado activity than any other state within the region. Texas is largely flat land and has a very high temperature at day time. Wind speed also consistently changes in the area. These conditions make Texas the perfect location for thunderstorm and tornado formation. The Sunflower State, also known as the Heartland of America, ranks second nationally in the average number of tornadoes per year.
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