A new study has found that more tornadoes may originate in long
line storms than previously thought. Many people think that the
tornadoes form in isolated super cells, but a new study suggests that as many as 18% of tornadoes arise from line storms. The researchers studied data from 3,800 tornadoes during the 1998 to 200 period. An article on Live Science reports on the study's findings:
The conventional wisdom is that the tornado threat goes down when the
cells merge into 100-mile-long line storms. But Trapp’s team found this
to be wrong, especially beyond the Alley. For example, about half of
Indiana’s 20 tornadoes a year come from line storms.
Nationwide, 79 percent of tornadoes arise out of cells, whereas 18
percent form from line storms, according to the study, which was
supported by the National Science Foundation and reported in the
February issue of the journal Weather and Forecasting.
The SPC keeps track of U.S. tornadoes on its Monthly Tornado Statistics webpage. The site also includes a list of deadly tornadoes and the number of people killed by them. Last year the United States experienced 1,722 tornadoes -- the most ever recorded in a single year.
