Increasing tornado outbreaks--Is climate change responsible?

[OKIsItJustMe]

http://engineering.columbia.edu/news/tornado-outbreaks-climate-change

[font face=Serif][font size=5]Increasing tornado outbreaks—Is climate change responsible?[/font]

[font size=4] Study raises new questions about what climate change will do to tornado outbreaks and what is responsible for recent trends[/font]

[font size=3] Tornadoes and severe thunderstorms kill people and damage property every year. Estimated U.S. insured losses due to severe thunderstorms in the first half of 2016 were $8.5 billion. The largest U.S. impacts of tornadoes result from tornado outbreaks, sequences of tornadoes that occur in close succession. Last spring a research team led by Michael Tippett, associate professor of applied physics and applied mathematics at Columbia Engineering, published a study showing that the average number of tornadoes during outbreaks—large-scale weather events that can last one to three days and span huge regions—has risen since 1954. But they were not sure why.

In a new paper, published December 1 in Science via First Release, the researchers looked at increasing trends in the severity of tornado outbreaks where they measured severity by the number of tornadoes per outbreak. They found that these trends are increasing fastest for the most extreme outbreaks. While they saw changes in meteorological quantities that are consistent with these upward trends, the meteorological trends were not the ones expected under climate change.

“This study raises new questions about what climate change will do to severe thunderstorms and what is responsible for recent trends,” says Tippett, who is also a member of the Data Science Institute and the Columbia Initiative on Extreme Weather and Climate. “The fact that we don’t see the presently understood meteorological signature of global warming in changing outbreak statistics leaves two possibilities: either the recent increases are not due to a warming climate, or a warming climate has implications for tornado activity that we don’t understand. This is an unexpected finding.”

The researchers used two NOAA datasets, one containing tornado reports and the other observation-based estimates of meteorological quantities associated with tornado outbreaks. “Other researchers have focused on tornado reports without considering the meteorological environments,” notes Chiara Lepore, associate research scientist at the Lamont-Doherty Earth Observatory, who is a coauthor of the paper. “The meteorological data provide an independent check on the tornado reports and let us check for what would be expected under climate change.”


[font size=1]Annual 20th, 40th, 60th and 80th percentiles of the number of E/F1+ tornadoes per outbreak (6 or more E/F1+ tornadoes), 1954-2015 (solid lines), and quantile regression fits to 1965-2015 assuming linear growth in time (dashed lines).
—Figure by Michael Tippett[/font]

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Posted: Dec. 1, 2016[/font][/font]

[TheMastersNemesis]

1. No It's God's Will. Only Jesus Can Save Us. Pray Pray Pray.

[HassleCat]

2. Pray for a reinforced basement.

And a week's worth of canned food.

[Warpy]

3. People get told they're getting hit by tornadoes because of gay people

in California and Mulims in the upper midwest and all those heathens of all types in New York City and they buy it. None of them ever seems to have any questions about their deity's lousy aim.

Peak tornado season in the deep south is December, then again in spring.