According to the June 27, 2023 U.S. Drought Monitor, moderate to exceptional drought covers 22.6% of the United States including Puerto Rico, a slight decrease from last week’s 22.7%. The worst drought categories (extreme to exceptional drought) increased slightly from 2.1% last week to 2.2%.
A distorted upper-level circulation pattern continued over North America during this U.S. Drought Monitor week (June 21–27). Such a pattern is termed highly meridional and consists of several parts. The first was a strong upper-level ridge of high pressure that stretched across North America, from Mexico to eastern Canada.
The ridge was responsible for the heat wave in Texas and above-normal temperatures in the Great Lakes. It was part of a trio of ridges over the Western Hemisphere. Another extended from Hawaii to western Canada and the third stretched from Bermuda to the Caribbean. These ridges were associated with warmer- and drier-than-normal weather over Hawaii, Puerto Rico, and the U.S. Virgin Islands. Upper-level troughs of low pressure were situated between these ridges over the western and eastern contiguous U.S. These troughs were responsible for a cooler-than-normal week over the western contiguous U.S. and Southeast to Mid-Atlantic states.
Weather systems moved through the western trough and penetrated into the central contiguous U.S. ridge. Showers and thunderstorms associated with them generated above-normal precipitation, as well as bouts of severe weather, across parts of the northern Rockies and much of the northern Plains and western portions of the central Plains. An upper-level low-pressure system became cut off from the jet-stream flow and slowly rotated across the southeastern contiguous U.S. to Ohio Valley during the first half of the week.
A cold front and surface low-pressure system associated with it brought above-normal precipitation and some severe weather to much of the Southeast and Atlantic Coast. But other areas not affected by these weather systems continued to be dry. Below-normal precipitation dominated the week across much of the West, southern Plains to Mid-Mississippi Valley, and parts of Alabama and Mississippi.
Drought or abnormal dryness contracted or was reduced in intensity in areas that were wetter than normal, especially in parts of the northern Rockies to northern Plains, western portions of the central and southern Plains, Tennessee Valley, and Mid-Atlantic to Northeast. But drought or abnormal dryness expanded or intensified where it continued to dry, especially across parts of the Pacific Northwest, southern Plains, and Mid-Mississippi to Ohio Valleys.
Nationally, contraction barely exceeded expansion, with the nationwide moderate to exceptional drought area slightly decreasing this week. Abnormal dryness and drought are currently affecting over 173 million people across the United States including Puerto Rico—about 55.6% of the population
The full U.S. Drought Monitor weekly update is available from Drought.gov.
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.
For additional drought information, follow #DroughtMonitor on Facebook and Twitter.
