A Benefit of the Drought: Fewer Tornadoes
The heat waves across much of the country have caused droughts and wildfires, but they also have reduced the number of tornadoes. About 300 tornadoes have hit the United States since mid-April, which is the fewest number in about 60 years and one-third the average, according to the National Oceanic and Atmospheric Administration (NOAA). Tornadoes cannot emerge unless there are thunderstorms, says NOAA's National Severe Storms Laboratory Research Meteorologist Harold Brooks.
The clash of two weather systems during severe storms helps tornadoes form, but this year a high-pressure system continues to hover over the middle of the United States with little precipitation and the system has pushed the jet stream north. In 2011, the weather system was nearly the opposite of current conditions, leading to more than 1,690 tornadoes and record flooding that generated more than $28 billion in damage, says NOAA. This year, more than 700 tornadoes have touched down in the United States, killing 68 people, but NOAA does not have damage estimates as yet.