This raises a question I have pondered, brought about by the detailed behaviour of melt in Beaufort. I expect near open water condition by September, but I wonder if there will be a stall in extent losses in Beaufort on the way to that state.
Beaufort extent started to fall on 20 April 2016 which seems to be the earliest in the short record of AMSR2 and the longer record of NSIDC Extent (I can't use the latter at the moment due to a satellite sensor failure).
Since then there has been an overall collapse of extent, however this has not been equal on all of the ice edge. Most of the loss has been towards the Chukchi Sea, while polewards the retreat of the ice edge has been limited, or has not happened at all.
In the following graphic I have marked the ice edge in red for a succession of days through May using images from Bremen University AMSR2. The final image shows an overlay of Cryosat 2 thickness in late April, with the band of thick ice (red patches) showing where the multi year ice is. The caveat here is that we don't know how that ice moved through May.
For ease of viewing I reproduce the final frame of the above animated gif below.
What the above shows is that recent losses of extent have mainly happened due to the progression of the ice edge along the Alaskan coast, within a few weeks there will be no more ice left to melt in this direction and the ice edge will then need to spread towards the pole. To do so it will need to pass through the multi year ice, and this may reduce the rate of losses.
However, I don't see this presence of multi year ice as able to cause the sort of prolonged stall seen through June of last year. ASCAT is a satellite radar system, the different backscatter of first year ice and multi year ice (due to dielectric constants) means that this can be used to spot the concentration of multi year ice.
Here is ASCAT from CERSAT on 1 May 2015. Showing a strong presence of multi year ice (green) in Beaufort.
While ASCAT from 1 May 2015 shows a far weaker presence than in 2016 at the same time.
Note that ASCAT detection of multi year ice is impaired by surface melt. However the difference shown above is supported by comparison using earlier dates in winter when there is no surface melt.
If continued the current trend of loss brings Beaufort extent to zero at the end of July, however it may not continue, a reduction of loss rate is possible within the coming weeks. Despite this I still expect Beaufort to be either totally ice free, or almost so, by September, and possibly earlier.