El Niño shifts U.S. drought patterns, easing in South and West

During meteorological autumn (September-November 2023), drought coverage across the Lower 48 states was nearly steady, ranging from 36%-40%, according to the U.S. Drought Monitor. However, there was significant regional variability, with Southeastern flash drought contrasting with an improving drought situation across large sections of the Great Plains, as well as an area stretching from the Pacific Northwest into the upper Midwest.

In recent weeks, El Niño, a phenomenon appearing for the first time since 2018-2019 and marked by unusually warm water in the central and eastern equatorial Pacific Ocean, appears to be finally taking the reins of North American weather patterns. Notably, late-autumn and early-winter storm systems have produced heavy, drought-easing rain in the South, especially in the Gulf Coast States. Heavy winter precipitation in the Deep South is typical during El Niño, due to an amplified subtropical jet stream, and winter forecasts from the National Weather Service’s Climate Prediction Center indicate Southeastern wetness is likely to continue into early 2024. At the same time, parts of the northern U.S. have experienced unusually dry weather in recent weeks, also emblematic of El Niño. Elsewhere, the western U.S. is heading into winter with significantly less drought coverage than a year ago.

By the end of November, drought covered less than one-third (28%) of the 11-state Western region, down from 69% a year ago. That change is evident in water storage, with California — currently free of drought — reporting statewide storage in 154 key reservoirs nearly doubling (from 68 to 125% of the historical average) during the 12-month period ending Oct. 31, 2023.

Brad Rippey is an agricultural meteorologist in the U.S. Department of Agriculture’s Office of the Chief Economist.