A cut-off loop in jet stream caused the May-1st snowstorm
After reading his previous article, I was idly wondering if increasing oscillations in the jet stream would cause loops to break off. In a weird bit of synchronicity his next article is about a loop that broke off a couple weeks ago.
The remarkable storm that brought record-breaking May snows and cold to the Midwest last week continues to spin over the Southeast U.S. The storm is unleashing flooding rains, bringing a case of "Weather Whiplash" to Georgia: flooding where extreme drought had existed just a few months ago.
The storm formed when a loop in the jet stream of extreme amplitude got cut off from the main flow of the jet over the weekend, forming a "cutoff low" that is now slowly spinning down as it drifts east over the Southeast U.S. On Sunday, the storm dumped 3.4" of rain on Atlanta, Georgia--that city's sixth heaviest May calendar day rain storm since record keeping began in 1878. Remarkably, the rains were also able to bring rivers in Central Georgia above flood stage. This portion of the country was in "exceptional drought"--the worst category of drought--at the beginning of 2013.
http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2399
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http://www.wunderground.com/blog/weatherhistorian/comment.html?entrynum=153