-> sterke aanwijzing voor een negatieve AO deze winter
There was a huge jump in snowcover today due to a storm in Europe. Europe will remain stormy the next 48 hours. There's only 4 more days to record, and I would put 50-50 odds that we'll match or exceed 2009. This is a really strong signal for a negative AO this winter. SAI and AO have a 0.86 correlation according to Cohen's paper.
Another important aspect of this year's advance is that we had overall higher daily extents than in 2009. (The y-intercept is higher.) I presume that this will strengthen the signal of the SAI due to the enhanced albedo effect.
Given this SAI signal, the persistently negative AO/NAO this fall, and the warm/cold/warm tripole in the Atlantic, blocking and cold air intrustions should be frequent this winter. With a weak El Nino signal out of the Pacific, the blocking is critical.
http://www.americanwx.com/bb/index.php/topic/34743-winter-2012-2013/page__st__2730#entry1821542
Quote selectie