The same effect happens up in Scotland in the Western Highlands (forget the name of the condition that causes it) when the wind blows off the Atlantic. Few days ago it was 6c down South in London area, up in the Highlands which is only about 1000 miles from Iceland the temp was 18c (a record)Living at the base of the Rockies in Denver I've learned that winter warm temps means lots of wind as fronts are preceded by winds blowing down the mtns and warming as they drop. Last weekend was 67 Sat, 75 Sun, winds around 20 mph gusts to 35; Monday we got 3-6" snow, temps dropped to -5F by Wed morning. Rode both days of the weekend, spent the past couple cleaning the bike. I'll ride down to about 40F but not on snow/ice.