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New Paper: Ocean Cycle Controls Tornado Activity, Not CO2

The Hockey Schtick

A new study finds that the severity and locations of tornadoes is strongly influenced by the natural Pacific Decadal Oscillation, with more severe tornadoes occurring during the warm phase and fewer during the cold phase.

The cold phase of the ~60-year Pacific Decadal Oscillation [PDO] started in the year 2000, and would explain why the US is currently experiencing the fewest tornadoes on record, and why higher CO2 is correlated with fewer severe tornadoes.

The US is currently experiencing the fewest tornadoes on record
Increased CO2 has nothing to do with tornadoes

Pacific Ocean Temperature Influences Tornado Activity in US

Oct. 17, 2013 — Meteorologists often use information about warm and cold fronts to determine whether a tornado will occur in a particular area. Now, a University of Missouri researcher has found that the temperature of the Pacific Ocean could help scientists predict the type and location of tornado activity in the U.S.
Laurel McCoy, an atmospheric science graduate student at the MU School of Natural Resources, and Tony Lupo, professor and chair of atmospheric science in the College of Agriculture, Food and Natural Resources, surveyed 56,457 tornado-like events from 1950 to 2011. They found that when surface sea temperatures were warmer than average, the U.S. experienced 20.3 percent more tornadoes that were rated EF-2 to EF-5 on the Enhanced Fuijta (EF) scale. (The EF scale rates the strength of tornadoes based on the damage they cause. The scale has six category rankings from zero to five.)

McCoy and Lupo found that the tornadoes that occurred when surface sea temperatures were above average were usually located to the west and north of tornado alley, an area in the Midwestern part of the U.S. that experiences more tornadoes than any other area. McCoy also found that when sea surface temperatures were cooler, more tornadoes tracked from southern states, like Alabama, into Tennessee, Illinois and Indiana.

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