El Nino Link to Tornado Likelihood in Southern U.S.

The waters of the Pacific Ocean may provide some clues on what kind of tornado season will erupt across the southern U.S., according to a paper in the journal Nature Geoscience.

The study found that if the Pacific enters an El Nino phase, a warming of the ocean’s surface, there may be fewer destructive storms across the South. Likewise, if the ocean cools to a La Nina state, the number of twisters may rise.

“We can forecast how active the spring tornado season will be based on the state of El Nino or La Nina in December or even earlier,” lead author John Allen, a post-doctoral research scientist at the International Research Institute for Climate and Society at Columbia University, said in a statement Monday.

Strong La Ninas produced more tornadoes and hailstorms across the South, including Oklahoma and Texas. El Ninos had the opposite effect.

Such storms accounted for 37.2 percent of all insured losses in the U.S. from 1994 to 2013, according to the Insurance Information Institute in New York, second only to hurricanes and tropical storms.

The state of the Pacific cannot pinpoint where tornadoes will strike and there are other factors that can influence the formation of severe storms, the authors said. The link between El Nino and tornadoes is strongest in the South.