* Astronomy

Global winds could explain record rains, tornadoes

Two talks at a scientific conference this week will propose a common root for an enormous deluge in western Tennessee in May 2010, and a historic outbreak of tornadoes centred on Alabama in April 2011.
Both events seem to be linked to a relatively rare coupling between the polar and the subtropical jet streams, says Jonathan Martin, a University of Wisconsin-Madison professor of atmospheric and oceanic sciences.
But the fascinating part is that the change originates in the western Pacific, about 9,000 miles away from the intense storms in the U.S. midsection, Martin says.
The mechanism that causes the storms originates during spring or fall when organized complexes of tropical thunderstorms over Indonesia push the subtropical jet stream north, causing it to merge with the polar jet stream.
Read more