Extratropical Highlights –June 2025

 

1. Northern Hemisphere

The 500-hPa circulation pattern during June featured above average height anomalies over the North Pacific Ocean, Europe, and central Russia, and below average height anomalies over the Greenland Sea (Fig. E9). The main land surface temperature signals include above average temperatures across Europe and central Russia (Fig. E1). The main precipitation signals include below average rainfall across Europe and above average rainfall in northern Russia (Fig. E3).

 

a. North America

The 500-hPa circulation pattern across North America featured a slight tilt toward above average heights for both the eastern and western coastal regions and near normal anomalies across Alaska and the central regions of Canada and North America (Fig. E9). Over the Hudson Bay and the Canadian Maritime, a slight tilt toward below average height anomalies was recorded during June (Fig. E9). Above average temperatures were recorded in the Eastern and Western U.S. with many areas reaching the highest 70th percentile of occurrences (Fig. E1). Drier than average conditions were recorded in the Pacific Northwest and along the Eastern Seaboard, while wetter than average conditions were recorded for the Southwest and Central Plains (Figs. E3, E5, E6). June is the typical month for an early onset of the Southwestern Monsoon. Precipitation totals for the monsoon region were above average for New Mexico and near average for Arizona (Figs. E5, E6).

 

b. Eurasia

The 500-hPa circulation pattern across Eurasia in June featured strongly above average height anomalies over Europe, moderately above average height anomalies over central Russia, and weakly below average height anomalies over Scandinavia and eastern Russia (Fig. E9). Temperatures were well above average across Europe and central Asia with many regions reaching the highest 90th percentile of occurrences (Fig. E1). Drier than average conditions were recorded across Europe with many areas reaching the lowest 10th percentile of occurrences (Fig. E3). Across northern Russia, wetter than average conditions were recorded with many areas reaching the highest 90th percentile of occurrences (Figs. E3, E4).

 

2. Southern Hemisphere

The 500-hPa circulation pattern during June featured an anomalous wavetrain with above average anomalies over the southern extent of the Pacific Ocean, below average anomalies over the Southern Ocean off the coast of Marie Byrd Land, above average anomalies over continental Antarctica, below average anomalies over the Southern Ocean off the coast of Queen Maud Land, and above average anomalies over the southern extent of the Indian Ocean (Fig. E1). Temperatures were slightly warmer than average along the Andes Mountain Range and slightly cooler than average in southern Brazil, South America (Fig. E1). Temperatures were slightly warmer than normal across Mozambique and the Cape of Good Hope in Africa (Fig. E1). Warmer than average conditions were recorded in the southern half of Western Australia where some areas reached the highest 90th percentile of occurrences (Fig. E1). Across North Australia and Queensland, cooler than average conditions were recorded (Fig. E1). Across northern Brazil and southern Argentina, drier than average conditions were recorded with several areas reaching the lowest 10th percentile, and continuing drought conditions in Northeast Brazil (Figs. E3, E4). Rainfall was below average in the western and eastern regions of Australia (Figs. E3, E4).