Have we any idea what is forcing the warm air? Is it the tropics? The Gulf Stream?
I smell another change happening and I can't figure out what the proximate cause is.
Maybe the persisting ridge which has been in north of Scandinavia is directing all excess heat and moisture to northern latitudes.
Whole of northern Europe has been in heatwave for a few months, being +10-20 Celsius above normal. All rain has been diverted to arctic ocean for over 3 months. The arctic sea coast has been in tropical temperatures for some weeks now, without the rain for actual tropical climate.
I think the ice is probably melting from below. There is not enough research done from below the surface, and I don't think analysis from air is sufficient.
Baltic sea SST anomaly is off the charts (from climate reanalyzer), more than +6 Celsius. After the jet stream changes the pattern soon, as is in the GFS forecast, all that heat from north will continue to be released to northern latitudes as the ground, lakes and sea cool down.
Maybe I'm doing gross assumptions