Wunderground.com - 4/12/13, Dr. Jeff Masters
The extreme 2012 drought in the Central Great Plains of the U.S. was more intense than any drought since record keeping began in 1895, says a new NOAA assessment of the historic drought, released Thursday. However, the study was unable to pinpoint the cause of the drought. Other major global droughts in recent years have been linked to global warming and/or natural variation in patterns of sea surface temperatures, but these factors were seemingly not important in causing the drought of 2012, said the team of 19 atmospheric scientists, led by Martin Hoerling of the NOAA Modeling, Analysis, Predictions and Projections Program (MAPP). Their study attributed the drought to a random natural variation in the jet stream, which caused it to become "stuck" far to the north in Canada. Since rain-bearing low pressure systems travel along the jet stream, the northwards displacement of the jet stream resulted in abnormally dry conditions over the Central U.S. "This is one of those events that comes along once every couple hundreds of years," said Hoerling.
Link: Wunderground.com
