Thank you both. Agreed, the tendrils are further south, maybe 200km. SST must be cooler or surface salinity fresher there. Perhaps as a result of all the MYI in the CAA last season?
edit: Concentration is a lot lower this year though.
I think there may have been some misbehavior from the Beaufort Gyre last summer which may have contributed to this. The SST gradient south of Newfoundland and Nova Scotia is substantially further S this year than in 2015 (and any other recent year).
At the same time, the area of mixing east of Newfoundland actually appears to be N of 2015. It looks like the SST changes also correspond to a substantial drop in salinity in the same region. While there have been consistent drops on the Scotian Shelf and the Grand Banks, it appears the largest change in 2019 has been on George's Bank, which has seen salinity drop 10% year over year (it has been fairly consistent until this year).
Besides the Beaufort Gyre's possible involvement it appears as though much of the NATL east of this gradient is substantially saltier than four years ago. Perhaps as the volume of warm water heading east / northeast increases, more of the freshwater input from Baffin / up north is kept closer to the continental shelf and the NE seaboard of North America? I don't know exactly what is going on but this is a pretty big change for a relatively low-latitude area that is bound to have significant impacts on sensible weather for both Eastern North America and Western Europe.
I would think the changes since 2015 (and year over year) may portend an impending summer that is even warmer than 2018 was over much of Europe.