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And we begin


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We slowed down the last few days, but there was a nice rebound today as snow cover started to extend westward. If the GFS is right, we should expand to 6.5 to 7.0 million km^2 by the end of the month. Several storms are progged in western Eurasia. We will probably fall just a little short of the 2009 trend line.

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We slowed down the last few days, but there was a nice rebound today as snow cover started to extend westward. If the GFS is right, we should expand to 6.5 to 7.0 million km^2 by the end of the month. Several storms are progged in western Eurasia. We will probably fall just a little short of the 2009 trend line.

Appreciate all of the updates. That's a sweet graph you've come up with to quantify the Cohen SAI

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Snow is focused mostly in western Canada and eastern Siberia...the other sides of the pole from us. That's a bad sign.

Eurasia is actually where we want it the most. Siberia is doing well overall, but western Eurasia was lagging a tad until some big gains today....looks to really continue for the next several days too. That is a good sign.

Here is the latest of a few papers on this:

http://www.nws.noaa.gov/ost/climate/STIP/FY11CTBSeminars/jcohen_062211.pdf

the original one by Cohen:

http://web.mit.edu/~jlcohen/www/papers/Cohen_SaitoGRL03.pdf

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Appreciate the updates. Are the years ranked in a paper or online somewhere?

Judah Cohen's 2011 paper: A new index for more accurate winter predictions

He has nice graphs back to the mid-70s. 1976 and 2009 stand out like sore thumbs. Now, barring a complete 'meltdown', it appears that 2012 will join them.

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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.

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post-7423-0-33247800-1351378714_thumb.jp

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.

excellent increase today, just a thing of beauty

and I note that in the great years like 02' and 09', there was a big buildup in western Russia into Europe, just like what is going on now

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We'll test that theory this winter. I think we'll see a very negative AO. Solar max/min is overhyped.

Regardless, although we're near a solar max (likely into 2013 and maybe early 2014), it is so weak that the activity is more typical of the midpoint between the max and min.

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Uh, ok. You do know warmer air causes more snowfall and thin ice? Some "fightin" words.

II have a question for you and the forum in general. If warmer air causes more snowfall and more snowfall generally results in colder temp.'s due to a higher albedo, might the Earth have a self-limiting mechanism to prevent runaway global warming at least for awhile?

Food for thought!

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