U.S. Drought: Weekly Report for February 20, 2024

According to the February 20, 2024 U.S. Drought Monitor (USDM), moderate to exceptional drought covers 16.6% of the United States including Puerto Rico, an increase from last week’s 16.3%. The worst drought categories (extreme to exceptional drought) decreased slightly from 1.3% last week to 1.2%.

An atmospheric river of Pacific storm systems slammed parts of the West Coast with heavy precipitation during this U.S. Drought Monitor week (February 14–20). The weather systems dried out as they crossed the western mountains, then produced anemic precipitation amounts east of the Rockies. Parts of the Midwest and Northeast received limited precipitation amounts from passing cold fronts, and heavier rain fell along the Texas coast and across Florida from another frontal system, but much of the country east of the Rockies, as well as the southwestern U.S., received little to no precipitation. The weather systems distorted the upper-level circulation over the contiguous U.S., which otherwise consisted of a high-pressure ridge over western North America and a low-pressure trough over the east. The end result of this distortion was a temperature anomaly pattern that consisted of warmer-than-normal weekly temperatures in the Upper Midwest and parts of the interior West, and below-normal temperatures in the Pacific Northwest, Rockies, and southern tier states, with near-normal temperatures elsewhere. An upper-level ridge over the Caribbean brought generally dry and warmer-than-normal weather to Puerto Rico and the U.S. Virgin Islands, while ridges also kept Alaska mostly drier and warmer than normal and Hawaii drier than normal this week. 

Drought or abnormal dryness expanded or intensified this week in parts of the Pacific Northwest, northern Rockies, northern Plains, Upper Midwest, Middle Mississippi Valley, Rio Grande Valley, eastern North Carolina, and much of Hawaii. Drought or abnormal dryness contracted or reduced in intensity in parts of the Four Corners states and Lower Mississippi Valley. Nationally, expansion was slightly more than contraction, so the nationwide moderate to exceptional drought area increased this week.

Abnormal dryness and drought are currently affecting over 58 million people across the United States including Puerto Rico—about 18.7% of the population.