Lets focus on the Eastern NW passage where there was more snowfall:
What happens with more snowfall has long lasting implications for sea ice. First we have greater cooling of top of sea when it falls in autumn, the snow floats doesn't melt, acts like a proxy ice cover, and accelerates the grey ice sea ice genesis. This creates more rapid onset of fast ice. Now, lets fast forward to its effect to this early summer, many months later from October-November just past. EOSDIS
pictures of June 29, 2015 and 16 are marked upper left corner. But the great deal of snow during winter of 2015-16 affected sea ice morphology, and therefore its current cooler summer weather.
Look carefully where the snow remains in 2016 and you will inherently find more sea ice, because snow help made it, and also created a buffer slowing its melt. But the larger implication is the local early summer weather snow and greater sea ice extent created, cooler, and also strangely but so, thinner sea ice. Winds of 2015 in the same area as on this GIF animation were dry, there was less snowfall, which happened more on the western European side of the Arctic which happens to have far less sea ice extent on its coastal shores. 2015 sea ice eventually became thicker when formed, but open water Polynyas in 2015 were much larger because there was a great deal of wind from the North (not unusual) keeping top of sea water from forming ice . In late spring 2015, the land warmed quicker, local weather was equally warmer and residual July snow footprint far lesser. WD June 30,2016