Extratropical Highlights - March 2026

 

1. Northern Hemisphere

The 500-hPa circulation during March featured a nearly concentric band of above average heights over the middle latitudes around below average heights over the high latitudes (Fig. E9). The main land-surface temperature signals include above average temperatures for the lower half of North America and Eurasia, and below average temperatures for the upper half of North America (Fig. E1). The main land-surface precipitation signals include drier than average conditions in parts of Europe and across the United States, and wetter than average conditions in northern Russia (Fig. E3).

 

a. North America

The height pattern across North America was split with below average heights across Alaska and Canada, and above average heights across the contiguous United States (Fig. E9). Temperatures were below average across Alaska and Canada, under the anomalous troughing, with many areas reaching the lowest 10th percentile of occurrences (Fig. E1). Across the contiguous United States, temperatures were above average and reached the highest 90th percentile of occurrences (Fig. E1). Drier than average conditions were recorded across most of the contiguous United States and the Alaska South Coast, where many areas reached the driest 10th percentile of occurrences, and wetter than average conditions were recorded in the Great Lakes region and the Alaska Panhandle (Fig. E3).

 

b. Eurasia

The 500-hPa height pattern was predominantly above normal across most of Eurasia with the exception of the central Siberian Plateau where height anomalies were below average (Fig. E9). Warmer than average temperatures followed the enhanced ridging pattern with many areas reaching the warmest 90th percentile of occurrences (Fig. E1). Drier than average conditions were recorded across Northern Europe where many areas reached the lowest 10th percentile of occurrences (Figs. E3, E4).

 

2. Southern Hemisphere

The 500-hPa height field featured a wavetrain pattern of weak to moderate anomalous circulation features (Fig. E15). Temperatures were above normal across most of South America and below normal for northern Australia (Fig. E1). Drier than average conditions were recorded for Argentina and continue for Brazil, and wetter than average conditions were recorded across the Andes, Chile, and central Australia (Figs. E3, E4). The South African monsoon season runs from October to April. Following a drier than average February, March rainfall totals approached the highest 90th percentile of occurrences, indicating above normal rainfall during the month (Fig. E4).