According to the May 30, 2023 U.S. Drought Monitor, moderate to exceptional drought covers 15.8% of the United States including Puerto Rico, a decrease from last week’s 16.1%. The worst drought categories (extreme to exceptional drought) decreased from 3.1% last week to 2.7%.
The upper-level circulation over the contiguous U.S. during this U.S. Drought Monitor week (May 24-30) was dominated by three features: a trough over the West, a ridge that extended from the southern Plains to the Great Lakes, and a cutoff low over the Southeast. This pattern resulted in targeted areas of precipitation, some of it heavy, while large parts of the contiguous U.S. received little to no precipitation.
Pacific weather systems moved across the West, but their fronts stalled out when they ran into the ridge over the Plains. The northwesterly flow associated with the trough inhibited precipitation across parts of the West, so the week was wetter than normal only from the Great Basin to the northern Rockies.
A southerly flow over the Plains was created between the western trough and the ridge further to the east. This flow funneled Gulf of Mexico moisture into the Plains. The moisture fed thunderstorms and weather complexes that developed along the stalled-out fronts and dry lines, resulting in above-normal precipitation across western portions of the Great Plains from Texas to Montana. Several inches of rain fell with some of these thunderstorms, resulting in localized flooding.
The ridge inhibited precipitation, so a large part of the country from the Mississippi River to the Northeast received little to no precipitation. The exception to this was the Southeast, where the cutoff low pulled in Gulf and Atlantic moisture to spread above-normal precipitation across much of Florida and the Carolinas to the Appalachians. Weekly temperatures averaged cooler than normal from the southern Plains to the East Coast, but they were warmer than normal across the northern Plains and northern parts of the West.
Abnormal dryness or drought spread across a large part of the Midwest and Northeast, and in parts of the Pacific Northwest, Puerto Rico, and Hawaii. Drought or abnormal dryness contracted or reduced in intensity across the Florida peninsula, across large areas in the western Great Plains, and in northwest Puerto Rico. Nationally, contraction exceeded expansion, with the nationwide moderate-to-exceptional drought area decreasing this week.
Abnormal dryness and drought are currently affecting over 124 million people across the United States including Puerto Rico—about 40.1% 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.
