@Rob, Given the large abnormality of snow coverage over the hymalayas this year, how much of the abnormal snow coverage for the northern hemisphere is due to that and how much to the arctic. Clearly there is way more snow coverage than last year but then last year was exceptionally early snow melt.

Bit off topic, I assume that the cryosphere today graphs are based upon faulty readings lately, or has there been an amazing recovery of ice. If its faulty data, why are they updating the graphs with the faulty data?

Forgive what might be a stupid question, but does anyone think its strange that the surface air temperature anomaly in the forcasts maps above have the northern part of Alaska and Canada at 20C above normal for the next 7 days, and that although the artic ice next to those bits are high, there only about 10c higher than normal. So does that mean that their is no snow/ice on those bits of Canada and Alaska, and if so is that normal for this time of the year.

Chris, the problem with dropping out the out layers in your analysis is that you are only dropping them from the most recent 8 year data points. To be valid you should perform the same criteria to all four of the 8 year time periods. That is the greatest drop and rise for the specified 8 year period should be dropped for each.