Thursday, November 24, 2011

Winter 2011-2012 Update

Winter has not been slow to arrive, even if you think it has. The reason you probably think winter is starting slow is because of the October snowstorm in the Northeast. Let me remind you how that storm was a VERY VERY LUCKY break for the Northeast and has a very low chance of happening anytime soon under normal conditions.

Anyways, this is a briefing on how winter is moving along.
To be honest, it hasn't been starting slow. We  recorded last year O'Hare Airport, Chicago's first snowfall came on December 12th, and they ended up with a historic snowstorm. Just a little bit to tell you.

The La Nina has recently been rumored to be unusually weaker than last year. Well of course it's weaker- it was always expected to be weaker than last year, so the effects will not be just as strong. This leaves more space for other variables to intervene, which they have been doing at the snow lover's disadvantage. At this point in time, we are seeing how some indices will be moving towards better waters:

(Green text is good for snow lovers, red text is bad, yellow text could go either way.)

The PNA will be moving towards positive territory
The NAO will be moving towards more neutral territory rather than positive territory.
The EPO will be dipping into negative territory, then staying around neutral territory.
The AO will be sliding towards neutral territory, but then rebounding into positive territory.
The La Nina should sustain itself or move slightly more negative over the winter.

The big question, of course, is when will winter start to act like winter??
We have gotten some indications that the Arctic Oscillation (AO) will be tanking at some point. We cannot independently confirm this, but we are looking for the certain indices that may be looking at this potential.
Recently, the ECMWF received an upgrade that some have indicated are showing signs of improvement in the model. Again, we cannot independently confirm this, but the long range ECMWF does show the Aleutian Low in Alaska breaking down (see what that does by clicking here), which may give the US  a little taste of winter. The teleconnections are changing, so winter may be on its way!

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