U.S. Drought Monitor Update for October 12, 2021

According to the October 12, 2021, U.S. Drought Monitor, moderate to exceptional drought covers 39.6% of the United States including Puerto Rico, a slight decrease from last week’s 39.7%. The worst drought categories (extreme to exceptional drought) decreased from 19.3% last week to 18.6% this week. 

A strong high-pressure ridge dominated the eastern contiguous United States. Strong Pacific weather systems moved into the West and slowed down, creating an upper-level trough over the western contiguous United States in the upper-level circulation pattern. Some cutoff lows and troughs penetrated into the ridge and made slow progress as they moved into the eastern contiguous United States. Surface fronts and low-pressure systems associated with the upper-level systems, in general, moved slowly across the country. The weather systems brought above-normal precipitation to three areas of the United States: a swath from the Southwest to northern Plains, another swath from the central Plains to southern Great Lakes, and an area in the Southeast. 

The week was drier than normal across the Northeast, much of the southern and central Plains, and across the Far West. The trough/ridge pattern kept temperatures warmer than normal east of the Rockies with cooler-than-normal temperatures along the West Coast. Drought and abnormal dryness expanded or intensified in parts of the southern Plains and central High Plains. Drought or abnormal dryness contracted or decreased in intensity in parts of the Southwest, Pacific Northwest, Plains, and Midwest. Overall, contraction slightly exceeded expansion, with the nationwide moderate to exceptional drought area decreasing this week.

Abnormal dryness and drought are currently affecting over 116  million people across the United States including Puerto Rico—about 37.4% of the population.