ASW

Thanks BobbdyDog, I need to start combing all the forums vigorously! Just want snow so much! Interesting looking at what you've done. Quite a bit more snow in middle of October in 2009 and 2010 on the Tibetan Plateau - thats around 30-35 degrees north - than in 2011. Bearing in mind the SAI, I wonder how much snow at that latitude is "worth" in terms of reflectance/atmospheric disturbance value compared to snow between 60 - 50 N. Maybe that paper that I cant load has already explained this anyhow. Just so excited at potential this year..

Thanks, so much research out there! Afraid I'm struggling to open it, but I'll try later. I read what you were saying about the SAI - below 60 N; however, I just wonder what happens if we take it to an even further extreme and below say only below 50 N - basically Mongolia southwards. I think the amount of sunlight increases exponentially - well not quite that quick! - as we go towards the equator? I know a lot of years in October barely see anything below 50 N but I just wonder.

http://www.wetterzentrale.de/topkarten/fsavnnh.html Low pressure development around Mongolia seen here.

Nice work BFTV. Potential snow cover increasing down into the Mongolian steppe in the coming week as low pressure develops in the region with associated 850hpa temperatures of 0-10 C around the low. Most of Mongolia above 1500m so potentially good for snow cover there, south of Siberia. That brings me onto another Siberian snow cover point. I once read/in those journal papers that the further south snow falls and the earlier it occurs in October the better. According to this snow cover further south reflects more sunlight into the stratosphere and causes resultant warming/ozone formation. I will look into doing a correlation between amount of snow in October at relatively southern laltitudes in Asia - Mongolian, Tibetian Plateau etc - and winter cet. See if there's any difference.

Another point to make is that even if you get snow in western russia at this time of year it wont last long on the ground, because western russia is on average warmer than eastern russia. I think to bottle up all the cold in eastern siberia is a good thing, meaning that the cold pool won't get diluted by travelling west. Also, remember how scientific research has suggested its the southern extent of snow in October that's important - because southern snow can cause stratospheric warmings - not the longitudinal extent. Also, there is more precipitation in western russia than east during the winter. It snows north of moscow etc in november/december whereas the further east you go the drier it gets as the autumn progresses.

if we could see the North Sea freezing... Then maybe we would see the white stuff creeping ever closer, at an earlier date. I wonder if that ever happened during the little ice age.

Though would it not depend on where the vortex set up shop for the winter? If as suggested a mid atlantic high becomes prominent, in that situation do you not get the vortex over Scandi? If the vortex was stronger that could result in lower pressure over Scandi, creating a bigger presure gradient between the high and low pressure, forcing stronger northerly winds over us and a colder air mass...