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SPECIAL COVERAGE: Living With Wildfires: San Diego Firestorm 10 Years Later

San Diego Researcher Says La Niña May Be Factor In Deadly Tornados

A tornado moves across western Iowa on June 5, 2010.

Credit: NOAA

Above: A tornado moves across western Iowa on June 5, 2010.


A San Diego researcher says La Niña may be partially to blame for the deadly tornado outbreak in the South and Midwest. More than 450 people have died in recent weeks from some of the largest and most powerful twisters on record.

More than 450 people have died in recent weeks from some of the largest and most powerful tornadoes ever recorded. The latest was on Sunday, when a super cell ripped through Joplin, Missouri killing 117 people.

Top 10 Deadliest Documented Tornadoes Events In U.S.

  1. March 18, 1925 - Category F5 - Missouri, Illinois, Indiana. 695 deaths
  2. May 6, 1840 - (Category unknown) - Mississippi, Louisiana. 317 deaths
  3. May 27, 1896 - Category F4 - Missouri, Illinois. 255 deaths
  4. April 5, 1936 - Category F5 - Mississippi - 216 deaths
  5. April 6, 1936 - Category F4 - Georgia - 203 deaths
  6. April 9, 1947 - Category F5 - Texas, Kansas, Oklahoma - 181 deaths
  7. April 24, 1908 - Category F4 - Louisiana, Mississippi - 143 deaths
  8. June 12, 1899 - Category F5 - Wisconsin - 117 deaths
  9. May 22, 2011 - Category F4 - Joplin, Misouri. 117 deaths (as of May 24)
  10. June 8, 1953 - Category F5 - Mississippi - 115 deaths

Source: NOAA

Scientists say it's the deadliest tornado season since 1925, when 695 people were killed in storms that raged through Missouri, Illinois and Indiana, according to the National Oceanographic and Atmospheric Administration (NOAA).

Tim Barnett, a researcher at Scripps Institution of Oceanography said it’s difficult to pinpoint blame for the extreme weather events.

“Part of it may be due to the La Niña that’s just dying in the equatorial Pacific Ocean. That was very strong this year, very strong.”

La Niña is a climate pattern that cools parts of the Pacific Ocean and typically pushes the jet stream north and west. Shifting weather patterns, combined with warm, moist air are the main ingredients for the killer storms.

NOAA officials estimate nearly 1,000 tornadoes have touched down so far this year -- double the total of a typical year. And 50 tornadoes have been fatal, compared to about 20 in an average year.

"In the future we expect that there will be an increase in certain extreme events due to climate change,” said Barnett.

Barnett said within 20-25 years, rising global temperatures will provide more energy to drive destructive storms on a regular basis.

In San Diego, climate change is expected to cause rising sea levels and prolonged heat weaves.

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