Emerging Drought Areas Heading Into 2023: Southeast U.S., East Africa and Argentina

Current soil moisture anomalies and 3-month trend: The West and Central U.S. drought remain intact during late August while dryness across Western Canada was more intense (Fig. 1). A wet Southwest U.S. monsoon extended wet benefits into Northwest Mexico while Southeast Mexico was drier. A wetter trend was noted across the Interior East U.S. In South America a wet trend was observed in Northeast and Southwest/Southeast Brazil plus rare rains in Chile and Peru. The Europe drought strengthened and became historic. Dryness in Western and Central Russia also accelerated. An intense China drought emerged and extend to the Bay of Bengal nations. However, India endured a wet monsoon season especially across western sections. Parts of East Africa were wetter during the past 3 months while tropical East Africa was dry. Far southwest Africa is in drought. Parts of Southern Australia were drier the past 3 months.

August 2022 global SSTA discussion: A 3^rd surge of La Nina emerged in August (Fig. 2). Based on multivariate ENSO index (MEI), a La Nina climate is well into a 3^rd year. The cool phase of the Pacific decadal oscillation (-PDO) is disrupted by emergence of marine heatwave NEP22B off the U.S. and Baja California Coast. NEP22B is a break-off of marine heatwave NEP22A north and northeast of Hawaii. Emergence of negative Indian Ocean Dipole formed northwest of Australia in August. The North Atlantic is a mix of cool waters across the northern ocean while a very warm surge associated with the Gulf Stream extends from the U.S. East Coast to southwest Europe. In the deep tropics, the tropical North Atlantic (TNA) index is marginally warm.

The 3-month outlook: The outlook extending through the remainder of 2022 projects several new emerging drought areas (Fig. 3). The southeast quadrant is expected to develop a dry climate (after any inland traveling tropical cyclones). The dry climate is linked to La Nina. East Africa is likely to develop significant drought due to the influence of the -IOD pattern. The -IOD pattern soaks Eastern Australia. Another South America drought is on the way. This one is centered on Argentina to Southeast Brazil and should include Paraguay and Uruguay. The northern half of Brazil is wet. Drought expansion across a large region east of the Caspian Sea is expected during the last quarter of 2022. The China drought is likely to continue into 2023. There are some emerging wet zones. The Northwest U.S. turns quite wet enhanced by La Nina. The Europe drought is expected to ease due to an early wet autumn. Southeast Africa turns wet but unclear is whether that benefit extends to southwest Africa.

Fig. 1: August 2022 global soil moisture anomalies and 3-month trend.

Fig. 2: August 2022 global SSTA anomalies and some of the regions of influence on global climate.

Fig. 3: August 2022 global soil moisture anomalies and 3-month forecast.