weathafella Posted September 18, 2012 Share Posted September 18, 2012 Those of you who have followed my posts over the past 10 years on the boards and the prior 5 on irc know that I have a snow cover fetish. Last year, an interloper used this same thread title and ran with it. No disrespect intended but people should at least change the wording. This year, I decided to wait until was reasonably sure that the ice melt which in the north polar regions has been unprecedented this year was over. There has been a pretty robust increase in ice today so now we begin. This picture will auto update I think so progress will be apparent in the first post of the thread. If you're like me and put alot of credence to autumnal snow cover, you'll follow this closely. Dr. Judah Cohen of MIT has done some great work correlating Siberian snow cover in October with stronger winter seasonal snows in the eastern US. Here's hoping it happens! Link to comment Share on other sites More sharing options...
mnweather Posted September 18, 2012 Share Posted September 18, 2012 Is there a correlation with other parts of the country as well? Link to comment Share on other sites More sharing options...
ineedsnow Posted September 18, 2012 Share Posted September 18, 2012 heres to hoping it builds quick! Link to comment Share on other sites More sharing options...
Poimen Posted September 18, 2012 Share Posted September 18, 2012 Thanks, weathafella. Been coming around looking for this thread the past few days knowing you would post sooner or later. Link to comment Share on other sites More sharing options...
weathafella Posted September 18, 2012 Author Share Posted September 18, 2012 Is there a correlation with other parts of the country as well? I'm not 100% sure but I think Cohen's work implies a favorable NAO in winter with a robust Siberian snow cover in October. Link to comment Share on other sites More sharing options...
SpartyOn Posted September 18, 2012 Share Posted September 18, 2012 The N American Continent is in desperate need of a moderate winter. Things need to balance out. Link to comment Share on other sites More sharing options...
nwohweather Posted September 18, 2012 Share Posted September 18, 2012 The N American Continent is in desperate need of a moderate winter. Things need to balance out. It will come either in the winter or spring. We saw 2 years ago the biggest switch ever from La Nino to El Nino and the result was pure chaos, just look at April of 2011 Link to comment Share on other sites More sharing options...
Juliancolton Posted September 18, 2012 Share Posted September 18, 2012 New to ice watching so how can I find daily progress? Is it just a guess based on the map? Thanks in advance. Link to comment Share on other sites More sharing options...
andyhb Posted September 18, 2012 Share Posted September 18, 2012 You mean La Nina... Link to comment Share on other sites More sharing options...
Quixotic1 Posted September 18, 2012 Share Posted September 18, 2012 You mean La Nina... El nina. Good start weatherfella. Been waitin' on this. Link to comment Share on other sites More sharing options...
phlwx Posted September 18, 2012 Share Posted September 18, 2012 the interloper cursed winter last year. Link to comment Share on other sites More sharing options...
am19psu Posted September 18, 2012 Share Posted September 18, 2012 the interloper cursed winter last year. Long live the interloper! Link to comment Share on other sites More sharing options...
SVT450R Posted September 18, 2012 Share Posted September 18, 2012 New to ice watching so how can I find daily progress? Is it just a guess based on the map? Thanks in advance. http://www.americanwx.com/bb/index.php/topic/156-arctic-sea-ice-extent/page__st__7560 https://sites.google.com/site/arcticseaicegraphs/ Link to comment Share on other sites More sharing options...
donsutherland1 Posted September 18, 2012 Share Posted September 18, 2012 Dr. Judah Cohen of MIT has done some great work correlating Siberian snow cover in October with stronger winter seasonal snows in the eastern US. For those who are interested, Dr. Cohen's paper can be found at: http://www.nws.noaa.gov/ost/climate/STIP/FY11CTBSeminars/jcohen_062211.pdf Here's hoping it happens! I strongly agree. Have a happy New Year, Jerry. Link to comment Share on other sites More sharing options...
radarman Posted September 18, 2012 Share Posted September 18, 2012 I'm not 100% sure but I think Cohen's work implies a favorable NAO in winter with a robust Siberian snow cover in October. The primary correlation was with the AO, although the AO and NAO are correlated as well of course. In any case, here's to a rapidly building cryosphere and strong upward wave-activity flux! Link to comment Share on other sites More sharing options...
Huffwx Posted September 18, 2012 Share Posted September 18, 2012 It's a special time when old man winter starts the ice progression thread! Best wishes to all for a great winter. Link to comment Share on other sites More sharing options...
Mallow Posted September 18, 2012 Share Posted September 18, 2012 I'm not 100% sure but I think Cohen's work implies a favorable NAO in winter with a robust Siberian snow cover in October. More specifically, a large change in snowcover during the month of October is what is especially well-correlated to the winter AO/NAO. Link to comment Share on other sites More sharing options...
SVT450R Posted September 19, 2012 Share Posted September 19, 2012 Link to comment Share on other sites More sharing options...
weathafella Posted September 19, 2012 Author Share Posted September 19, 2012 For those who are interested, Dr. Cohen's paper can be found at: http://www.nws.noaa.gov/ost/climate/STIP/FY11CTBSeminars/jcohen_062211.pdf I strongly agree. Have a happy New Year, Jerry. Thank you Don. And thank you for teaching all of us again and again. I hope you are well and perhaps this year there can be some nic additions to the digital snow museum. Link to comment Share on other sites More sharing options...
Eskimo Joe Posted September 19, 2012 Share Posted September 19, 2012 For those who are interested, Dr. Cohen's paper can be found at: http://www.nws.noaa....ohen_062211.pdf I strongly agree. Have a happy New Year, Jerry. What a read, thanks for sharing Don. I was taking a look at the graphics and it seems that a cold winter in the eastern US / Canada occurs when snow cover is especially prevalent across Scandinavia and central Siberia. EDIT: This should be pinned. Link to comment Share on other sites More sharing options...
weathafella Posted September 20, 2012 Author Share Posted September 20, 2012 Nice start of the Siberian snow cover fwiw. Probably still transient but maybe not with the AK vortex that wrecked our winter last year migrating southwest? All speculation and probably wrong but it's fun to think about. Link to comment Share on other sites More sharing options...
Mallow Posted September 20, 2012 Share Posted September 20, 2012 Nice start of the Siberian snow cover fwiw. Probably still transient but maybe not with the AK vortex that wrecked our winter last year migrating southwest? All speculation and probably wrong but it's fun to think about. Actually we kinda want snowcover to start off below normal in Siberia for October. Cohen's latest paper, as I mentioned earlier, shows a much stronger correlation with the change in snowcover during the month of October than the average snowcover for the month. http://web.mit.edu/jlcohen/www/papers/CohenandJones_GRL11.pdf Link to comment Share on other sites More sharing options...
griteater Posted September 20, 2012 Share Posted September 20, 2012 Actually we kinda want snowcover to start off below normal in Siberia for October. Cohen's latest paper, as I mentioned earlier, shows a much stronger correlation with the change in snowcover during the month of October than the average snowcover for the month. http://web.mit.edu/j...Jones_GRL11.pdf Does Cohen, or anyone else ever make an official prediction on the AO in November after all of the October snowcover data is in? We can make assumptions, but it would be nice to see a prediction based on the actual calculated October SAI, etc. Link to comment Share on other sites More sharing options...
HM Posted September 20, 2012 Share Posted September 20, 2012 Actually we kinda want snowcover to start off below normal in Siberia for October. Cohen's latest paper, as I mentioned earlier, shows a much stronger correlation with the change in snowcover during the month of October than the average snowcover for the month. http://web.mit.edu/j...Jones_GRL11.pdf While that's certainly implied, I think you are jumping the gun a bit here. The real important thing is the rapid acceleration of snow cover that sufficiently affects temperature and circulation along/south of 60°N in Eurasia. Southern areas are more likely to see this gain or acceleration later in the month, of course, so that may possibly explain why the change in snow cover is more correlated. In the end, all that matters is that the snow cover affects the circulation. Pardon my use of memory here (I don't have the data in front of me at the moment) but I think a great example of starting off well below normal and accelerating quickly in the week 40-44 time frame was 1994-95. However, if you check the actual temperatures and wind over Asia, it clearly was insufficient at affecting circulation. Link to comment Share on other sites More sharing options...
Ed Lizard Posted September 20, 2012 Share Posted September 20, 2012 Which is the chicken and which is the egg. Is the rapidly building Eurasian snowcover a sign of a pattern favorable for a negative AO? If it was snowcover, and not rate of change of snowcover, I'd think snowcover was the chicken, but rate of change sounds more like the egg. Link to comment Share on other sites More sharing options...
radarman Posted September 20, 2012 Share Posted September 20, 2012 Which is the chicken and which is the egg. Is the rapidly building Eurasian snowcover a sign of a pattern favorable for a negative AO? If it was snowcover, and not rate of change of snowcover, I'd think snowcover was the chicken, but rate of change sounds more like the egg. Although much of his work deals with correlations, he has postulated some causal mechanisms focused around the effects of albedo change. Even in the recent paper referenced above, there does seem to be some skepticism on his part about why the correlation to the SAI is better than the SCE, and HM summarized the reasons for that a bit. When Cohen adds stuff like this "Assuming that the high albedo of snow cover is one if not the most important snow characteristic that influences the overlying atmosphere..." I think it's fair to say he believes it to be the chicken. Link to comment Share on other sites More sharing options...
MillzPirate Posted September 20, 2012 Share Posted September 20, 2012 Any update on the number total of expanse? Seems like last year it was updated daily to include gains Link to comment Share on other sites More sharing options...
Mallow Posted September 20, 2012 Share Posted September 20, 2012 Although much of his work deals with correlations, he has postulated some causal mechanisms focused around the effects of albedo change. Even in the recent paper referenced above, there does seem to be some skepticism on his part about why the correlation to the SAI is better than the SCE, and HM summarized the reasons for that a bit. When Cohen adds stuff like this "Assuming that the high albedo of snow cover is one if not the most important snow characteristic that influences the overlying atmosphere..." I think it's fair to say he believes it to be the chicken. This. The fact is, the SAI is better correlated to the winter AO than the SCE. Whatever the reasons, that's just what the data shows. It's not a perfect correlation, so there are exceptions (of course), but unless you can show me your own index based on, say, southern Siberian snow cover that has an even better correlation than the SAI, I'm sticking with the SAI. So, yes, I am rooting for low snowcover anomalies at the beginning of October, and high at the end. In other words, we don't fully understand the physics, but we have the statistics. So unless you understand the physics well enough to discriminate such details (and beat the statistics), you're not going to convince me to go against the statistics. Link to comment Share on other sites More sharing options...
Chaser25973 Posted September 20, 2012 Share Posted September 20, 2012 Here's where we were in September of 2007: Here's where we are today: Shall I pixel count? Link to comment Share on other sites More sharing options...
Analog96 Posted September 20, 2012 Share Posted September 20, 2012 Here's where we were in September of 2007: Here's where we are today: Shall I pixel count? Don't need to. We are a lot higher today. But why did you pick 2007? Link to comment Share on other sites More sharing options...
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