Extratropical Highlights – March 2022

 

1. Northern Hemisphere

The 500-hPa circulation features during March resembled wintertime La Niña and Tropical/Northern Hemisphere teleconnection patterns (Figs. E7, E9).  Strong above-average height anomalies were observed over Scandinavia and moderate above-average heights were observed over the North Pacific and Atlantic Oceans, eastern Russia, and across southern Eurasia, and below-average height anomalies were observed over Newfoundland, southern Europe, and central Russia (Fig. E9).

The main land-surface temperature signals during March included above-average temperatures for western North America, eastern U.S., western Europe, Scandinavia, eastern Russia, and much of Asia, and below-average temperatures were observed for regions south of the Black Sea (Fig. E1).   The main precipitation signals during March were above-average rainfall totals in parts of North America and southern and eastern Eurasia and below-average rainfall totals along coastal U.S. states and Europe (Fig. E3).

 

a. North America

The anomalous height pattern for March matched with canonical wintertime La Niña and Tropical/Northern Hemisphere teleconnection patterns (Figs. E7, E9).  The predominantly off-shore above-average height anomalies ushered in above-average temperatures for much of Alaska, the U.S. West Coast, Eastern Seaboard, Midwest, and Southeast, while much of central North America observed near-normal temperatures for the month of March (Fig. E1).  Drier than average conditions were observed for the U.S. Coastal areas, to include most of the West Coast, Gulf States, and Eastern Seaboard, and above-average rainfall was observed in the U.S. Midwest, parts of the Southeast, Florida, and Pacific Northwest (Figs. E3, E6).  While the Midwest observed rainfall greater than the 90th percentile of occurrences (Fig. E5) which led to at least a Class 1 improvement in drought for much of the Great Lakes region (Drought Monitor not shown), several states in the western U.S. observed significant departures from normal, including California which recorded rainfall in the lowest 25th percentile of occurrences (Figs. E3, E5, E6).

 

b. Eurasia

The 500-hPa height pattern for March featured above-average heights across much of Asia and eastern Russia which ushered in above-average temperatures for those same areas (Figs. E1, E9).  Significant above-average temperatures were observed across most of Asia and eastern Russia with some areas reaching the 90th percentile of occurrences (Fig. E1).  Drier than average conditions were observed in Europe where rainfall for the month of March was in the lowest 10th percentile of occurrences, and above-average rainfall was observed across much of Spain, east and west of the Caspian Sea, the Tian Shan Mountains, central Siberia, along the coastal regions adjacent to the Yellow Sea and East China Sea, and eastern Russia (Fig. E3).  Precipitation anomalies were in the 70th and 90th percentile for these areas (Fig. E3).

 

2. Southern Hemisphere

The 500-hPa height pattern for the month of March featured an anomalous wave-train with above-average heights in the South Pacific Ocean near New Zealand and west of Chile, and in the South Atlantic Ocean over South Sandwich Island (Fig. E15).  Below-average heights were observed over the South Pacific Ocean near the Antarctic Circle and Southern Ocean, east of Argentina, and north of Wilkes Land, Antarctica (Fig. E15).  Above-average land-surface temperature anomalies were observed for New Zealand and northern Australia with these regions reaching the 90th percentile of occurrences (Fig. E1).  Above-average rainfall was recorded for western Columbia, northern and southeastern Brazil, southern and central regions in Africa, and along the southeastern flanks of Australia, and below-average rainfall was observed in central Brazil, southern Chile and Argentina, Gabon and Ethiopia in Africa, and northern Australia (Fig. E3).  The South African monsoon season runs from October to April. After a rather dry February, observed rainfall during March was above-average for most of the region and with some areas reaching the 80th percentile of occurrences (Figs. E3, E4).