La Niña Arrives, Likely to Exacerbate Southern Drought

La Niña is here. But unlike the El Niño that preceded it, this climate event is expected to be weak and short-lived, the National Oceanic and Atmospheric Administration said Thursday.

But that doesn’t mean the U.S. won’t see some of the typical impacts of a La Niña; forecasters expect it to tilt the odds in favor of warmer, drier conditions across the already drought-stricken southern portions of the country and wetter, cooler conditions across some of the northern regions.

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These shifts change where heat is pumped into the tropical atmosphere, which has knock-on effects throughout the global atmosphere, impacting weather conditions thousands of miles away, including in the U.S. In particular, El Niño tends to favor cooler, wetter conditions across the southern tier of the U.S., while La Niña flips the script and favors warmer and drier weather there.

Drought conditions already stretch from Southern California to northern New Mexico and from eastern Texas and Oklahoma into the western Carolinas. The most intense drought — reaching the two highest categories on the U.S. Drought Monitor — is in central and southern California and northern Alabama and Georgia.