Lack of snow cover is helping to propel a mild climate across Europe. However, a colder change may be on the way in the extended range. Stratospheric warming propelling an arctic air mass in Canada and into the East U.S. during early December shifts westward to Asia during the next 2-3 weeks. The emerging stratospheric warming over Asia will cause a cold air mass to initiate across Northern Asia into early next week.

The wet weather pattern has shifted to Brazil during early December. Heavy rain was observed across Northern Chile to northwestern Argentina during the past week. The 10-day outlook equally combining GFS and ECM reveals wet weather shifts to Paraguay and eastward. Recently developed dryness in Argentina continues.

Snowfall forecasts by NBM indicate moderate to heavy snow across the Upper Midwest, Great Lakes, and Interior Northeast States today through tomorrow. More snow although not as heavy extends across the North-central U.S. to the Interior Northeast States later this week. More snow is likely from the Ohio Valley across the Northeast States this weekend. The ongoing snowfall leaves deep snow cover for the Midwest to the Northeast by middle of next week (Fig. 6). The deepening snow enhances arctic air presence peaking in strength early next week across the PJM System.

ECM indicates potential for flooding rainfall during the middle third of December across Eastern Bolivia, Paraguay, and Southwest/Southeast Brazil. The rain may abate in the 11-15-day period. The 24-hour change indicates a significant increase in rainfall for Paraguay and eastward. The culprit is an intensifying upper trough extending from east of Argentina northwestward into Brazil during much of the next 2 weeks.