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.