First, from the Danish Institute Centre for Ocean and Ice dataset of the region north of 80°, it's obvious that the Arctic polar area has not been exceptionally warm the past year versus previous periods. Indeed, as the 2010 graph reveals, the 2010 polar summer was one of the coldest compared to the long-term average (green curve) - see top of 2010 curve that has temperatures below the average summer period, close to the blue melt line. (click on images to enlarge)
Second, as the below Rutger's dataset reveals, the northern hemisphere snow coverage through the end of January 2011 is not exceptional. The 37-month average confirms that the alarmist idea that recent atmospheric "warm" conditions are holding loads of moisture ready to blanket the northern hemisphere is a bunch of bunk. Nothing extraordinary here, move along Mr./Ms. alarmist.
Finally, a graph of the precipitation rate for the northern hemisphere, generated from NOAA's National Centers for Environmental Prediction reanalysis dataset, shows a slow decline of precipitation rates over an extended period. It certainly does not indicate that recent year's winter precipitation was exceptionally high. As the matter of fact, the below graph suggests that the AGW hypothesis of a warming atmosphere holding more moisture that in turn causes more precipitation is suspect.
Although there have been specific regions in the northern hemisphere that have experienced large snowstorms the past few months, these exceptions happen every year in some part of the world during winter months. Based on the Arctic polar temperatures, and the level of snow coverage and trend of precipitation rates though, the alarmist claim that global warming in the Arctic is causing more snow and cold for more southern latitudes just does not hold any water, per the empirical data.
One other eye-opening graph comes from the good folks at www.climate4you.com. This graph plots the relative humidity at different atmospheric heights, which clearly shows that "global warming" is not causing relative humidity to increase as the AGW theory requires. (Hmmm...,or is this a graph of alarmist humility as their beloved theory disintegrates with every new data point?)
Update: Confirmed via email with Gorm of the Danish Institute Centre for Ocean and Ice that their Arctic temperatures are not extrapolated from regions outside of the Arctic area - unlike NASA, which extrapolates (calculates) temperatures from weather stations located 1,200 kilometers south of the Arctic. To put the NASA methodology in geographical context, they would calculate Toronto, Canada temperatures based on Myrtle Beach, South Carolina weather information, which is 1,200 km south of Toronto. Of the major world climate agencies, only NASA is dumb enough to perform this ludicrous 1,200 km extrapolation. It's the primary reason their Arctic temperatures are so off-the-wall bizarre.