It happened a while back, but it's one of those interesting details that make what's happening in the Arctic so unique. In August we saw something that hasn't been recorded before (not on that scale, that is): the detachment of large parts of the ice pack. In October the opposite happened.
In the East Siberian and Laptev Seas freezing started on the coasts before the ice pack had expanded far enough to reach them first. For a couple of days, the freezing on both sides caused a large pool of open water surrounded by ice on all sides:
In a way the detachment had something to do with this event, as a lot of ice floes that had been part of the little ice pack were still bobbing around (just not enough to show up on the Uni Bremen sea ice concentration maps), making freezing easier near the coast. But of course, the main reason for this to happen is the fact that the edge of the ice pack was so far North. I think bilateral freezing on this scale is a first.
So the East Siberian and Laptev Seas froze over relatively quickly, the Beaufort Sea was behind on schedule (causing a nice new record anomaly dip), but is now filling up nicely, Baffin Bay and the Kara/Barentsz Sea are late, late, late (as can be seen on the regional graphs page of the ASI Graphs website). I will soon start to compare those regions, but in the meantime I have extended the concentration maps on the aforementioned ASI Graphs website with November, so you can compare to previous years yourself.