Droughts show improvement, but reservoir storage still a concern

Between October 2023 and February 2024, drought coverage across the Lower 48 States dipped from 40% to 19%, according to the U.S. Drought Monitor. The improvement was related to El Niño, a periodic warming of the central and eastern equatorial Pacific Ocean, and a corresponding active storm track across the United States. During the winter of 2023-24, the area experiencing the greatest decrease in drought coverage and intensity generally extended eastward from the central and southern Great Plains. However, a few areas, including the northern tier of the western United States, missed out on the cold-season bounty, leaving high-elevation snowpack significantly below average by early spring in much of Montana, Washington and northern sections of Idaho and Wyoming.

Heading into the 2024 warm season, there are a few areas of concern related to spring and summer water supplies. First, statewide reservoir storage is below average for this time of year in New Mexico and Washington. Second, National Weather Service outlooks indicate the likelihood of drier-than-normal spring weather in parts of the Northwest and Southwest, with expectations for drought development or persistence. Key areas that may be affected by spring drought include portions of Arizona, New Mexico and Texas, as well as the nation’s northern tier from the northern Rockies into the upper Great Lakes region. However, weather and water-supply outlooks are more optimistic in many other areas of the country, including California, where recent storms have boosted the Sierra Nevada snowpack to above-average levels. Prior to 2022-23 and 2023-24, the last time the Sierra Nevada snowpack ended two consecutive seasons with near- or above-average water equivalency was 2015-16 and 2016-17.

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