Global Soil Moisture Anomaly Analysis Reveals Dramatic Dryness North/South America While Much of Eurasia is Wet

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In North America nearly the entire continent trended drier during SEP/OCT/NOV most notably across the Southwest U.S., Great Basin and California. Additional drying took place in Alaska and much of Canada. The catalyst to the drier climate is the warm SSTA pattern either side of North America promoting anomalous dry/warm high pressure. The Southeast U.S. wet pattern was fueled by tropical cyclone activity. Central America also reversed much wetter due to late season tropical cyclones.

Fig. 1: The global NOAA/CPC global soil moisture anomaly analysis for November 2020 and annotated 3-month soil moisture change.

Discussion: A dramatic difference in soil moisture anomaly pattern between the dry Americas and wet Eurasia (Fig. 1).

In North America nearly the entire continent trended drier during SEP/OCT/NOV most notably across the Southwest U.S., Great Basin and California. Additional drying took place in Alaska and much of Canada. The catalyst to the drier climate is the warm SSTA pattern either side of North America promoting anomalous dry/warm high pressure. The Southeast U.S. wet pattern was fueled by tropical cyclone activity. Central America also reversed much wetter due to late season tropical cyclones.

In South America the Chilean drought re-intensifies. Dryness across northeast Argentina, eastern Paraguay and southeast Brazil also intensified each key crop areas. Slowly, the northwestern South America drought is eroding. A much wetter regime was apparent across far southern Argentina.

Remarkably, there is little change to a widely variable (mostly wet) soil moisture regime across Africa. In Australia dryness lingers although slightly less intense for southwest and northeast Australia. Interestingly, the Australia Bureau of Meteorology indicates the southwest Australia conditions are wetter. Western Indonesia trends wetter the past 90 days.

The Europe soil moisture regime is mostly unchanged except for wetter conditions for U.K. and Portugal. The most dramatic regime (and trend) is a profound drought condition in the Black Sea region stretching to South-central Russia and Kazakhstan. Northern Russia trends slightly drier. Across East and South Asia wet soil conditions dominate and the trend the past 90 days is wetter especially Northeast China and Coastal Southeast Asia.