May 14, 2013

Weather Whiplash

Weather Whiplash in the Midwest: a 70° warm-up in just one day

It's weather whiplash says underground's weather historian Christopher C. Burt in his latest post. After record May cold and snows hit the Great Lakes over the weekend, a ferocious May heat wave is in full bloom today. Several cities are poised to experience their greatest 1-day May temperature swing on record today. Chicago bottomed out at 36° on Monday morning, and this afternoon's high is predicted to be 88°--a spectacular 52° change in temperature in just one day. The all-time record for a one-day warm-up in the Windy City during May is 50°, set May 1, 1992. A 50°+ temperature swing is also expected in Minneapolis, where the high today is predicted to be 94°, coming on the heels of a 41° low Monday morning. The most dramatic "Weather Whiplash", though, came in Aberdeen, South Dakota, where the mercury hit 22° on May 12, then shot up to 92° on May 13--an astonishing 70° rise in just one day! 


Weather Whiplash in the Southeast: 3.4" of rain after an extreme drought




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.

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