-NAO Causes U.S. and Europe Storms Including Early Season Chill for Europe

Updated Europe/Western Russia winter 2024-25 outlook issued today.

Fig. 1-2: High impact storms are focused on the 6-10-day period affecting the U.S. and Europe.

Discussion: Storm system emerges in Western Texas early next week (Fig. 1). The storm (all rain) drifts to the Midwest States by early Tuesday. Severe thunderstorms roll across the Mid-south. By mid-next week, a hurricane slams the west coast of Florida while a winter storm develops in the North-central U.S. Blizzard conditions generate over the Dakotas. By Thursday, snow (and rain) persists across the Upper Midwest. More snow for the Upper Midwest late in the 6-10-day period.

In Europe, an upper trough brings snow to Northern Europe to reverse the lack of early season snow in that region this weekend (Fig. 2). By Monday, a wintery feel with wind is emerging across U.K., North-central Europe, and Northeast Eurasia. A mid-next week rainstorm emerges over West-central Europe with trailing cold air that could cause some snow in U.K. and possibly as far south as Northern Spain. Ahead of the storm, windy and mild weather for Eastern Europe. By late next week, a line of squalls rolls across Eastern Europe while much of Europe turns unseasonably chilly. The European chill across the entire region by late in the 6-10-day period, continues in the 11-15-day period.

Recent forecasts have indicated the wet weather across Brazil during the next 7-10 days would shift southward to Northeast Argentina/Southeast Brazil in the 8-14/11-15-day period. However, a forecast change is indicated by GFS and ECM (Fig. 3) from overnight. Forecast models maintain the wet weather across Brazil continues in the extended range. Wet weather of the past several weeks has eroded the Brazil drought while rains previous to that time weakened Argentina drought (Fig. 4).

Fig. 3-4: Percent of normal rainfall over the next 15 days across Brazil and daily soil moisture anomalies for South America.