Numerous strong tornadoes are wreaking havoc in Central and Southeastern U.S. this spring. Politicians and the media are blaming these storms on global warming. The real cause is that unusually persistent cold air masses are colliding with warm, moist Gulf air to produce wind shear which spawns tornadoes.
Meteorologist Dr. Roy Spencer (Principal Research Scientist at the University of Alabama and former Senior Scientist for Climate Studies at NASA’s Marshall Space Flight Center) opines: “To claim that global warming is causing more tornadoes is worse than speculative; it is directly opposite to the clear observational evidence.”
Dr. Spencer notes:
Very few thunderstorms produce tornadoes. In the hot and humid tropics, they are virtually unheard of. The reason why is that (unlike hurricanes) tornadoes require strong wind shear, which means wind speed increasing and changing direction with height in the lower atmosphere.
These conditions exist only when a cool air mass collides with a warm air mass. And the perfect conditions for this have existed this year as winter has refused to lose its grip on the western United States. So far for the month of May 2019, the average temperature across the U.S. is close to 2 degrees Fahrenheit below normal. (Source)
This year, the Northern Plains have been averaging 5-10 deg. F below normal due to cold air masses stretching from Michigan, through Colorado to California. It’s weather, not global warming. As Dr. Spencer notes, the number of strong to violent U.S. tornadoes has gone down from 60 in 1954 to 30 in 2018.
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