Extratropical Highlights - June 2026

 

1. Northern Hemisphere

June 2026 featured a strongly amplified 500-hPa circulation pattern, highlighted by anomalous ridging across Europe and central Eurasia (Fig. E9). This Eurasian ridge was part of a larger hemispheric wave pattern, with additional ridging over parts of Canada and the North Pacific, and a pronounced negative height anomaly near the Arctic. The main land surface temperature signals include above average temperatures across Europe and Russia (Fig. E1). The main precipitation signals include below average rainfall across Europe and above average rainfall across the European Plain and the Central U.S. (Fig. E3).

 

a. North America

The 500-hPa circulation pattern across North America featured widespread near normal heights with slightly above average heights in localized areas such as the U.S. Southeast, West Coast, and Southern Alaska (Fig. E9). Above average temperatures were recorded across most of the southern U.S. and southern Alaska where most areas reached the highest 70th percentile of occurrences (Fig. E1). Across the U.S. Southwest temperatures were recorded in the highest 90th percentile of occurrences (Fig. E1). Above average precipitation was recorded across the U.S. Central Plains and Mississippi Valley where much of the area reached the highest 70th percentile of occurrences (Fig. E3). June is the typical month for an early onset of the Southwestern Monsoon. Precipitation totals were above average across the Southwest with many areas reaching the highest 80th percentile of occurrences (Figs. E5, E6).

 

b. Eurasia

The 500-hPa circulation pattern across Eurasia in June featured widespread ridging with in particular, modestly amplified ridging over Europe and strongly amplified ridging over Russia (Fig. E9). The amplified ridging pattern ushered in widespread above average temperatures. Many areas across Europe and Russia recorded temperatures in the highest 90th percentile of occurrences (Fig. E1). Above average precipitation was recorded across the European Plain where many areas reached the highest 90th percentile of occurrences (Fig. E3).

 

2. Southern Hemisphere

The 500-hPa circulation pattern during June exhibited an annular mode which featured anomalous ridging encircling a center of troughing over the South Pole (Fig. E1). Across most of South America, Africa, and Australia, temperatures were above average with southern Africa and southern Australia, in particular, recording temperatures in the highest 90th percentile of occurrences (Fig. E1). Drier than average conditions were recorded across eastern South America and northeastern Australia (Figs. E3, E4).