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Severe Storms (not including Hurricanes)

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By studying the network of weather stations across the US, researchers have found a couple of interesting results — the biggest storms recorded in a given year are increasing in strength, and the frequency of extreme storms is also increasing.

Map of U.S. showing results of the trends of the biggest storms of each year as recorded by weather stations across the U.S.
The above figure shows the results of the trends of the biggest storms of each year as recorded by weather stations across the US, and you can see that although the pattern is somewhat complex, the general story here is that big storms are getting bigger.

In addition, the frequency of extreme storms is also increasing. An extreme storm is one where the rate of precipitation exceeds by a certain amount the long-term mean rate of precipitation for a given site (so an extreme storm in a wet region like the northeast US has a much higher precipitation rate than an extreme storm for a drier region). So you might be asking yourselves whether these results translate into more frequent, massive hurricanes slamming into Florida. This is a somewhat controversial topic. The consensus answer is that with a warmer atmosphere, hurricanes will become more powerful, but not necessarily more frequent. Still, as we will see in Module 11, this poses a great threat to coastal communities.

Map of U.S. showing results of the trends in the frequency of extreme storms as recorded by weather stations across the U.S.
The figure above shows the results of the trends in the frequency of extreme storms as recorded by weather stations across the US, and you can see that the overwhelming pattern is one more frequent extreme events.

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