Oddest Trough Over Europe

Wei was the first one who pointed out the European cold wave to me, last week:

W.: The Chinese media says it's cold in Europe.

M.: (looking at model output) Hmmm. These temperatures look OK to me!

But what do I know? I'm not trying to survive under snow drifts in the Balkan mountains, or anything....

Apparently it's a terrible time in Europe, and some people are blaming a breakdown in the Arctic Oscillation (AO), which heretofore has been protecting Europe from the cold. Some people have been blaming the AO for California's dry weather. I hope they're right, and that AO has suffered a terrible accident.

But whatever is going on in Europe, it's left a very-odd-looking trough over the continent.