According to the June 13, 2023 U.S. Drought Monitor, moderate to exceptional drought covers 20.9% of the United States including Puerto Rico, an increase from last week’s 18.3%. The worst drought categories (extreme to exceptional drought) decreased from 2.0% last week to 1.8%.
This U.S. Drought Monitor week (June 7-13) was characterized by a convoluted upper-level circulation pattern over North America. A strong upper-level ridge of high pressure maintained its grip across central portions of North America, with its core extending from central Canada into the north-central portions of the contiguous U.S. Strong troughs of low pressure moved around the ridge in a complicated dance, rotating from the west, to its north, and then to the east of the ridge. Some troughs undercut the ridge as they moved across the southwestern states and into the central states, while another huge low-pressure system became anchored over the Great Lakes.
The ridge kept temperatures warmer than normal over the Pacific Northwest to northern Plains. The eastern troughs and closed low sent cold fronts across the eastern half of the contiguous U.S., resulting in a cooler-than-normal week for much of the region from the central Plains to the East Coast; only the Gulf of Mexico coast averaged near to warmer than normal. The southwestern troughs were responsible for cooler-than-normal air over the Southwest to the central Plains.
A northerly flow over the Upper Mississippi Valley directed cool, dry, and smoky Canadian air into the northern and eastern states. Showers and thunderstorms were generated by the troughs and fronts, but precipitation was above normal for the week only in certain areas. These areas included parts of California to the Pacific Northwest, the northern Rockies, western parts of the northern and central Plains, and a few areas in the southern Plains, Lower Mississippi Valley, Southeast, and Northeast.
Large parts of the contiguous U.S. from the Mississippi Valley to East Coast, parts of the Southwest, Plains, and West Coast, and other parts of the Pacific Northwest, had a drier-than-normal week. Drought or abnormal dryness contracted or was reduced in intensity in areas that were wetter than normal, especially in parts of the West and western portions of the Great Plains. But drought or abnormal dryness expanded or intensified where it continued to dry, especially in parts of the Pacific Northwest, large areas along and east of the Mississippi River, and parts of Hawaii and the Caribbean. Nationally, expansion exceeded contraction, with the nationwide moderate to exceptional drought area increasing this week.
Abnormal dryness and drought are currently affecting over 170 million people across the United States including Puerto Rico—about 54.8% of the population.
In addition to Drought.gov, you can find further information on the current drought on this week’s Drought Monitor update at the National Drought Mitigation Center.
The most recent U.S. Drought Outlook is available from NOAA’s Climate Prediction Center. The U.S. Department of Agriculture’s World Agriculture Outlook Board also provides information about the drought’s influence on crops and livestock.