Stratospheric warming returns to Siberia in 12+ days. Risk of arctic air generating in Eurasia returns. If so, where does the air mass travel? The midday (Jan. 31) suggests the air mass evolves and may want to travel cross-polar into North America. The risk is still low but increasing for potential important cold in the U.S. Feb. 18-24.

Extremes are ahead as February arrives. Featured is extreme heat risk in Argentina with an attendant dry climate. Parts of Australia have observed a much hotter than normal mid-summer and the heat becomes more extreme into early February. Mostly dry and mild this week in Europe but a vigorous storm track returns next week. The second cold outbreak of winter so far is heading for China during the medium range.