I've been watching the open water down the eastern side of the Antarctic Peninsula. I said the cause of that was most likely strong westerly winds.
If you look at the sea ice concentration on the western Antarctic Peninsula you can see the effect of these westerly winds.
Towards the end of September 2016 the ice edge is compacted as the sea ice is pushed against the Peninsula.
The westerly winds (from bottom left to top right) compress the sea ice against the land (left hand side of the Antarctic Peninsula). This also creates open water on the eastern (right hand side ) of the Peninsula as the sea ice is pushed away from the land.
You can see the very sharp ice edge on the west, and the open open water in the MODIS satellite imagery.
The sea ice concentration anomaly for September 2016 shows that on both sides of the Antarctic Peninsula the westerly winds have reduced the amount of ice we would expect to observe by up to ~40%. On the west side because the sea ice is compressed, on the east side because the sea ice is being pushed away from the land.
This is just late winter weather.
There are a lot of Antarctic research stations on the west of the Antarctic Peninsula, including Rothera, the largest British Base. If the winds maintain the westerly direction then I can imagine it could be slow to resupply the base this season. There is time for it to change. According to the published schedule the ship is not due to arrive until 27 November 2016.
A slow resupply is not uncommon and I have been on at least one unsuccessful resupply voyage in my career. I took the picture below on 11 December 2004 under similar conditions.