A climate expert has attributed the increase in the number and severity of US tornadoes and severe storms in 2011 to a change in weather patterns.
The researcher, from Kansas State University, credits the increased tornado production this year to jet stream patterns in the upper atmosphere. The patterns have created synoptic events such as the April tornado outbreak in Alabama and recent tornado in Joplin, Missouri. While these events are not unprecedented, they are significant, he said.
“We have these good historical precedents for specific synoptic events, but they’re starting to come more frequently together. That’s what is very interesting, is that this weather system seems to be getting more variable.”Read more at Kansas State University