Tornadoes (continued)The central U.S. contains a unique
mix of topography and weather factors that combine to create these
ferocious weather systems. The most favorable situation for these
storms to develop is during the months of April through June when there
is the most contrast between air masses in the central United States.
The region of highest concentration is that of "tornado alley", a
region that stretches from eastern Nebraska through central Kansas and
Oklahoma in to the panhandle of Texas. The tornado season varies with
latitude, with the southeastern U.S. season from January through
March and the north central states during July through
September. On April 3, 1974 148 tornadoes struck 13 states
leaving a swath of death and destruction across the U.S.[
Figure 8.30 Tornado risk in the United States Tornadoes are categorized on the
basis of their destruction by the Enhanced Fujita
scale. The scale assigns a tornado a 'rating' based on estimated wind speeds and related damage. Several damage indicators, e.g., trees, motels, strip malls are used to estimate wind speeds and classify the tornado. [
Figure 8.31 Get inside a tornado.
Learn more about the destructive effect of tornadoes by "Digging Deeper: The April 27, 2011 Southern USA Tornado Outbreak".
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