This winter has seen a series of unusual weather hit the Arctic in general, it has been much warmer than average in the high Arctic since October though there have also been some periods of extreme cold, especially in western Greenland but also new high temperature records have been set in the east and north.

There has also been a succession of heavy storms hitting Greenland. Starting in October these storms have dropped a lot more snow than average over Greenland, particularly on the eastern side and in the south. This increasing mass has not gone unnoticed and we have received a number of questions about it, so here we attempt to summarise what we know and can infer about the winter 2016-2017 and what it might mean to the overall surface mass balance year 2016-2017.

The surface mass balance year goes from September to August, with most of the snow falling between September and May (known as the accumulation season) and melt generally dominating June-August (known as the ablation season). The accumulation season got off to a flying start in October, when a series of large storms hit the east coast of Greenland dropping 264mm of rain in the main town of Tasiilaq in 25 days, compared to the average for October of 83mm for the whole of October. Most of the precipitation from these storms fell as rain at lower levels but as this freezes in the surface snow over the ice sheet it still adds ice to the ice sheet. However, these storms also meant that Autumn was record warm in east Greenland with all DMI weather stations on the east coast recording the warmest or second warmest October on record. These records stretch back to 1873 in some places on the east coast.

The October storms boosted the accumulation of snow over the ice sheet far above what is normal for the time of year as we see in the curve below, though since December, the amount of snow falling over the ice sheet has followed a more normal pattern.