Gavin Hannah

I don't see the westerlies dominating this year. Even if we do have to endure them for a few weeks, I think the massive Siberian snow cover is going to come to our rescue. I'm looking for the Siberian High to move westwards and deliver the goods come mid - late December.

I agree, every time I see a northerly, I just know that all we will get is some cold days and nights with relatively little in the way of inland convection. Bring on the beasterly.

As it's still early in the season, it will be interesting to watch the Ice and see if it stalls (slow growth or minor melt) at all this month. If we continue at the pace currently being set, we could be way above 7 Million sqKM by the end of October.

Don't worry, it's still on the increase. The latest value: 6,162,905 km2 (October 7, 2013) http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

Ah I've misread the PDF. If I remember correctly, we got a major snow event on Dec 20 2009. I was positive this was preceded by a SSW. The PDF mentions the following .... I've obviously interpreted that as a SSW due to speed reading lol. Broke the 6 Million mark with sea ice. The latest value: 6,016,476 km2 (October 6, 2013) You need to go back to 2006 to find a year with more sea ice at this same date which recorded a value of 6,221,380 KM2 http://www.ijis.iarc.uaf.edu/seaice/extent/plot_v2.csv

The latest value: 5,931,507 km2 (October 5, 2013) Three 100K+ gains in a row. Not far from the 6 Million mark now. Should pass that tomorrow.

Doesn't appear to be any sport of PV forming just yet...At least, nothing that would signal a winters death for us.

So far, I've included snow and ice data, solar observation data and the Arctic Oscillation data. Here is some info on the North Atlantic Oscillation. http://www.windows2universe.org/earth/climate/images/nao_lg_gif_image.html Winter (December through March) Index of the NAO based on the difference of normalized sea level pressure (SLP) between Lisbon, Portugal and Stykkisholmur/Reykjavik, Iceland since 1864. The SLP anomalies at each station were normalized by division of each seasonal mean pressure by the long-term mean (1864 - 1983) standard deviation. Normalization is used to avoid the series being dominated by the greater variability of the norther station. During the positive phase of the NAO, a large pressure gradient across the North Atlantic creates strong winds that drive winter storms across the Atlantic and into Northern Europe. During the negative phase, there is on a small pressure gradient. Southern Europe and Africa receive weak winter storms while Northern Europe and the eastern United States are cold a dry. https://climatedataguide.ucar.edu/climate-data/hurrell-north-atlantic-oscillation-nao-index-station-based Current NAO Situation http://www.cpc.ncep.noaa.gov/products/precip/CWlink/ENSO/verf/new.nao.shtml Summary From the data posted so far, looking at the winter of 2010 specifically, we can take away the following observations. Sea Ice extent is down on the mid 20th century averages. (Relevant to Cohens Theory) Winter 10/11 saw a severely negative Arctic Oscillation. - Conducive to weak polar vortex. The NAO was also severely negative. - Ideal for cold blocking. The sun was spotless and in a minimum phase. Weak solar output compared with output during a maximum phase. Note: I'm ignoring SSW events in this summary as I can't find any references to one in the run up to winter 2010. I may have been thinking of the SSW that occurred in Dec 09 that led to the cold and snow event in Jan 2010. http://www.atmos-chem-phys-discuss.net/12/7243/2012/acpd-12-7243-2012-print.pdf

The latest value: 5,815,552 km2 (October 4, 2013) http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm Roughly, a gain of 130KM2 between the 3rd and 4th of October.... Not too shabby.

The Ice extent should continue to grow. However, there might be the odd stagnant day in October such as yesterday. Only 5K growth i believe. But as you say, the snow may very well shrink if the weather warms up over Siberia. Looking at the months forecast, I'd wager the snow levels will be higher by the end of October. What is of interest to me is where exactly will that snow be?? Will it be confined to East Russia / Asia, or will it be taking a higher latitude and spreading west?

Hi guys, Following the discussion on here regarding the links between UK winters and the Eurasian snow buildup in autumn, I've decided to open a comparison topic. Specifically, we'll be comparing this years run up to winter with some of the previous autumn/winter data. As the weeks progress, I will add to this thread. Please contribute anything if you feel I've missed anything. Solar Situation More data plots available here. http://sidc.oma.be/sunspot-index-graphics/sidc_graphics.php 2010 Snow & Ice 2011 Snow & Ice 2012 Snow & Ice 2013 Snow & Ice October 4th October 4th October 4th October 3rd Ice: 5,696,935 KM2 Ice: 5,045,982 KM2 Ice: 3,927,099 KM2 Ice: 5,675,521 KM2 October 27th October 27th October 27th Ice: 7,751,957 KM2 Ice: 7,688,250 KM2 Ice: 7,169,323 KM2 November 20th November 10th November 13th Ice: 9,575,789 KM2 Ice: 8,861,284 KM2 Ice: 8,714,262 KM2 November 26th November 26th November 26th Ice: 9,920,062 KM2 Ice: 10,163,067 KM2 Ice: 10,050,317 KM2 December 1st December 1st December 1st Ice: 10,281,787 KM2 Ice: 10,505,579 KM2 Ice: 10,487,669 KM2 Arctic Oscillation Links: http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm http://www.natice.noaa.gov/ims/ http://www.nc-climate.ncsu.edu/climate/patterns/NAO.html http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/month_ao_index.shtml Personal Thought. Looking at the IMS images, its apparent that although October 10 started off with a higher Ice Extent value, both 2011, and 2012 saw 1st December kick off ahead of 2010. Taking into account what happened in 2010, If I remember correctly, there was a SSW event 6 weeks prior to the widespread snow event. (Chiono could perhaps confirm this) and if I recall correctly, a SSW can weaken the polar vortex which could go some way to explaining why the Ice extent slowed its advance compared with both 2011 and 2012. The AO index also shows a very negative index value for the winter of 2010/11. 500mb Height Anomalies During a Negative AO So if i'm correct about there being a SSW in 2010, then coupled with a severely negative AO, then the conditions were just perfect for the snow and cold event which ensued. Throw in a spotless sun and you could say it was the 'perfect storm'.

Dont quote me on that lol. Chiono is the best person to ask.

I believe an extensive snow cover over russia/east europe also acts as a feedback mechanism. Raising the chances of a SSW event. As Feb91 said, there are more knowledgable members here who can expand on this.

It's like night and day the difference in snow cover. I have a good feeling that we will benefit from this upcoming period.

On the same wavelength as you! I would love for us to have some very pleasant autumnal weather and then come end of Nov, start of Dec, BLAM! An instant switch to winter wonderland.

Well the East European / Russian snow cover is waaaaay above normal atm. Latest IMS images uploaded in the Snow and Ice Thread. Lots of positive anomalies .

Yet more snow gains!! Yesterdays Todays

October has the potential to deliver to some surprise cold and snow. Personally, the idea of HP over us for much of October would lead me to see this as a remote possibility. I mentioned several months back that it's better to get the HP/Euro now (sep-october) as it keeps things cold and snowy in Russia / East Europe. If Cohens' theory pans out, we will reap the rewards in winter. Perhaps another Nov/Dec blast???

Found this on Metcheck.com. http://www.metcheck.com/UK/article.asp?ID=367&Article=Winter+2013+-+Another+Beast? Thoughts? I was of the impression that the pattern DID change to allow the Jet to finally head north which gave us our decent summer...?

The current Euro high is projected to last a few weeks yet which is good for Russia and East Europe. Lots of cold and snow. Scandinavia will flux more depending on how the HP waxes and wanes.

The current set up looks like ensuring that large parts of Russia and east Europe will continue to feel the chill with the HP set up over the UK / near continent. A big boon for us cold lovers eagerly watching the advancing snow cover across Russia.

I can't delete the image lol, Never mind, that was still yesterdays IMS image.....lol.

The siberian side of the arctic is looking very gd. The north american side is below average but like every year, its down to weather patterns. I believe northern hemispher snow cover is in the positive overall, which is the crucial thing. We need good buildup of snow and for it to advance west this month.

The latest value: 5,608,684 km2 (October 1, 2013) http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm Check out the climb the red line is making. Looking very steep.

This forum needs a trend tally to keep track of how many runs favour blocking and how many favour mobile patterns. Id put my money on 50 - 50 lol.