WidreMann Posted October 4, 2013 Share Posted October 4, 2013 All in Siberia. North American looks pretty crappy. Link to comment Share on other sites More sharing options...
free_man Posted October 4, 2013 Share Posted October 4, 2013 Some great increases already and as many have alluded to it looks like we will have a great pattern to continue the increases. increasing the great in every great increase Link to comment Share on other sites More sharing options...
free_man Posted October 4, 2013 Share Posted October 4, 2013 All in Siberia. North American looks pretty crappy. Looks great Link to comment Share on other sites More sharing options...
Mallow Posted October 4, 2013 Share Posted October 4, 2013 All in Siberia. North American looks pretty crappy. The increase in Siberia (and Eurasia in general) is where it matters for the winter AO. Link to comment Share on other sites More sharing options...
WidreMann Posted October 4, 2013 Share Posted October 4, 2013 The increase in Siberia (and Eurasia in general) is where it matters for the winter AO. Do we want it to be this expansive so early? I thought that was the point of the research. Link to comment Share on other sites More sharing options...
wxmx Posted October 4, 2013 Share Posted October 4, 2013 Do we want it to be this expansive so early? I thought that was the point of the research. http://www.americanwx.com/bb/index.php/topic/41113-and-we-begin/#entry2419012 Link to comment Share on other sites More sharing options...
Mallow Posted October 4, 2013 Share Posted October 4, 2013 Do we want it to be this expansive so early? I thought that was the point of the research. In addition to what wxmx linked, the gains are what really matter. I prefer it to start below average (south of 60N) because that makes bigger gains easier, but there are cases where the snow advance index was high even though we started the month above normal. A lot of this is because the standard deviation of snowcover over Eurasia at the end of October is much higher than at the beginning. We did start the month above normal this year. Link to comment Share on other sites More sharing options...
NJwinter23 Posted October 4, 2013 Share Posted October 4, 2013 While it may be creating the above average snow cover across northern russia and expansive ice coverage currently, I believe we would want to see that vortex position over northern russia change going through Oct. Iv you look at years with impressive SAI, they had blocking over those regions in Oct. i'd post some esrl images, but our government blows. Link to comment Share on other sites More sharing options...
Snow_Miser Posted October 7, 2013 Share Posted October 7, 2013 Updated comparison between the 1st of this month and now. Today on the left, October 1st on the right. Link to comment Share on other sites More sharing options...
cfbaggett Posted October 8, 2013 Share Posted October 8, 2013 Here's the Eurasian snowcover (between 30 and 60 degrees North) for the first 7 days of October. The SAI has a small sample size (1998 to present). Within that sample, I don't believe there are any years that have started as anomalously high as this year. I think we are in unprecedented territory in regard to the SAI. Link to comment Share on other sites More sharing options...
Sunny and Warm Posted October 8, 2013 Share Posted October 8, 2013 Here's the Eurasian snowcover (between 30 and 60 degrees North) for the first 7 days of October. The SAI has a small sample size (1998 to present). Within that sample, I don't believe there are any years that have started as anomalously high as this year. I think we are in unprecedented territory in regard to the SAI. where did you find that product? thanks Link to comment Share on other sites More sharing options...
KokomoWX Posted October 8, 2013 Share Posted October 8, 2013 where did you find that product? thanks I messaged him about it too. He responded indicating he took the raw data and made it himself. I hope he shares an updated one in a few weeks. Link to comment Share on other sites More sharing options...
The_Global_Warmer Posted October 10, 2013 Share Posted October 10, 2013 Eurasian Topography. Look at those valleys, bet they get tons of cold pouring in off the arctic basin. Link to comment Share on other sites More sharing options...
ORH_wxman Posted October 11, 2013 Share Posted October 11, 2013 I messaged him about it too. He responded indicating he took the raw data and made it himself. I hope he shares an updated one in a few weeks. He did a few updates last year using the same data and home-made graph. I agree, the graphs are nice. Link to comment Share on other sites More sharing options...
Snow_Miser Posted October 13, 2013 Share Posted October 13, 2013 2013 is well ahead of 2012 in terms of Eurasian snowpack and SIE. It's behind though in NA snowpack. Link to comment Share on other sites More sharing options...
cfbaggett Posted October 14, 2013 Share Posted October 14, 2013 Here's an update for this year's SAI. Our areal extent anomalies are still running above normal, so we'll need a huge end to October to have a positive SAI this year. That being said, there are probably other physical mechanisms at play with such a large snow extent to begin the month. This year is eerily similar to 2002. Snowcover in 2002 also got off to a quick start. Also, in the eastern US, October was two-faced: blowtorch to begin the month and deep cold anomalies to end the month. I'd happily take a repeat of 2002-03. Link to comment Share on other sites More sharing options...
Mallow Posted October 14, 2013 Share Posted October 14, 2013 Here's an update for this year's SAI. Our areal extent anomalies are still running above normal, so we'll need a huge end to October to have a positive SAI this year. That being said, there are probably other physical mechanisms at play with such a large snow extent to begin the month. This year is eerily similar to 2002. Snowcover in 2002 also got off to a quick start. Also, in the eastern US, October was two-faced: blowtorch to begin the month and deep cold anomalies to end the month. I'd happily take a repeat of 2002-03. Thanks for the update! Link to comment Share on other sites More sharing options...
sebastiaan1973 Posted October 14, 2013 Share Posted October 14, 2013 It seems impossible to get a better SAI than 2009 and 2012, due to the 'high start'. More importantly is the physical reasoning behind the SAI, the cooling effect. In my opinion it's only a good thing too start as soon as possible with that. Anyway, coming days more snowfall south of 65N, so we can expect an increase. Link to comment Share on other sites More sharing options...
Mallow Posted October 14, 2013 Share Posted October 14, 2013 It seems impossible to get a better SAI than 2009 and 2012, due to the 'high start'. More importantly is the physical reasoning behind the SAI, the cooling effect. In my opinion it's only a good thing too start as soon as possible with that. Anyway, coming days more snowfall south of 65N, so we can expect an increase. The October SAI is better-correlated with the winter AO than just plain old average October snowcover (that was Cohen's original index on the topic, in fact). Link to comment Share on other sites More sharing options...
NJwinter23 Posted October 14, 2013 Share Posted October 14, 2013 It seems impossible to get a better SAI than 2009 and 2012, due to the 'high start'. More importantly is the physical reasoning behind the SAI, the cooling effect. In my opinion it's only a good thing too start as soon as possible with that. Anyway, coming days more snowfall south of 65N, so we can expect an increase. The reason why later October is important is because the state of the polar vortex formation. Furthermore, advancement south of 60N has a lot to do with greater amount of sunlight being reflected back from the albedo of snow cover --> stronger Siberian/Mongolian high forming --> stronger wave flux to the stratosphere Link to comment Share on other sites More sharing options...
vortmax Posted October 15, 2013 Share Posted October 15, 2013 The reason why later October is important is because the state of the polar vortex formation. Furthermore, advancement south of 60N has a lot to do with greater amount of sunlight being reflected back from the albedo of snow cover --> stronger Siberian/Mongolian high forming --> stronger wave flux to the stratosphere Is there a way to measure the state of the polar vortex in November and how this year's SAI affected it (compared to previous years)? Link to comment Share on other sites More sharing options...
Snow_Miser Posted October 15, 2013 Share Posted October 15, 2013 Updated comparison between October 14 and October 1. Link to comment Share on other sites More sharing options...
Sunny and Warm Posted October 15, 2013 Share Posted October 15, 2013 lots more ice as well. In an earlier post, I inserted a graph of the arctic temps about 80N. It is now averaging below zero F in that area (below average as well) and obviously spilling into the remainder of the arctic. Will be interesting to see how the weather responds as we get further into the season. The Oct/Nov temp couplet in the States has been a killer the last several years. Link to comment Share on other sites More sharing options...
GaWx Posted October 15, 2013 Share Posted October 15, 2013 lots more ice as well. In an earlier post, I inserted a graph of the arctic temps about 80N. It is now averaging below zero F in that area (below average as well) and obviously spilling into the remainder of the arctic. Will be interesting to see how the weather responds as we get further into the season. The Oct/Nov temp couplet in the States has been a killer the last several years. I wonder if the increased ice/cold Arctic reduces the chance for a very dominant -AO this winter vs. if the ice hadn't expanded so much vs. 2012. Link to comment Share on other sites More sharing options...
The_Global_Warmer Posted October 16, 2013 Share Posted October 16, 2013 I wonder if the increased ice/cold Arctic reduces the chance for a very dominant -AO this winter vs. if the ice hadn't expanded so much vs. 2012. I don't think so. The new ice is very thin. The heat exchange to help slow down the Westerlies and pump up ridges is in full force. Link to comment Share on other sites More sharing options...
vortmax Posted October 17, 2013 Share Posted October 17, 2013 Is there a way to measure the state of the polar vortex in November and how this year's SAI affected it (compared to previous years)? Anyone? Link to comment Share on other sites More sharing options...
Snow_Miser Posted October 17, 2013 Share Posted October 17, 2013 I might be wrong about this, but I'm not particularly thrilled about the ridging on the Ensembles over Eurasia. I would imagine that would be pretty poor for the SAI. Link to comment Share on other sites More sharing options...
Snow_Miser Posted October 20, 2013 Share Posted October 20, 2013 Liking how the Euro is bringing more troughing south of 60 N in Eurasia in the short to medium range. Link to comment Share on other sites More sharing options...
cfbaggett Posted October 21, 2013 Share Posted October 21, 2013 SAI updated. Unless we see a very extensive growth in snowcover to end the month, the SAI is pointing toward a +AO winter. Link to comment Share on other sites More sharing options...
GaWx Posted October 21, 2013 Share Posted October 21, 2013 SAI updated. Unless we see a very extensive growth in snowcover to end the month, the SAI is pointing toward a +AO winter. Agreed. Ironically, the 2013 SAI is currently partially being hurt by there being so much snow near the end of Sep. and during the first few days of Oct. as that has caused the sloped line to start at almost 2 million sq. km. The other three years started at under 1/2 million sq. km. Had 2013 also started around 1/2 million sq. km, the 2013 current slope would have been much higher than it is and a good bit higher than 2007. Isn't it sort of counterintuitive that just starting the month with "too much" snow, via causing the SAI indicator to be lower than it otherwise would have been, will reduce the prospects for a good (-AO) winter? Does it make sense that above average late Sep. to very early Oct. snow hurts the SAI? Link to comment Share on other sites More sharing options...
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