We have seen major changes in the polar regions with small warming.
The arctic is expected to be 5-9C warmer by 2100. Most of that will be in April, May, and October.
I think if global weather patterns change it will be when the high lat oceans are much warmer. When arctic circle snow cover melts in April and is gone by May.
Who knows.
But I have no doubt methane will start rising much faster over the next decade