According to the September 24, 2024 U.S. Drought Monitor (USDM), moderate to exceptional drought covers 28.5% of the United States including Puerto Rico, a decrease from last week’s 29.8%. The worst drought categories (extreme to exceptional drought) increased from 2.3% last week to 2.6%.
The upper-level circulation across the contiguous U.S. (CONUS) during this USDM week (September 18–24) seemed like a slow dance between low-pressure troughs and a strong high-pressure ridge. A complex of troughs dominated the West while the ridge hung on over the southern Plains to Northeast. Warmer-than-normal temperatures were associated with the ridge, while the week was near to cooler than normal over much of the West. The western trough complex slowly moved into the central states, pushing the ridge eastward ahead of it. As the western trough complex pushed eastward, surface lows and cold fronts that were associated with it generated above-normal precipitation across parts of the Southwest to Montana, and from Colorado and New Mexico to the southern Great Lakes. To complicate matters, as last week ended, the remnants of Potential Tropical Cyclone 8 had merged with another low-pressure trough over the Southeast. This eastern trough started this week over the East Coast, but it was reluctantly pushed out over the Atlantic as everything else moved eastward. A surface low and frontal system associated with the eastern trough brought above-normal rain to the Mid-Atlantic states early in the week.
The rest of the CONUS was drier than normal for the week. These dry areas included much of the West, most of the southern and northern Great Plains, the Lower Mississippi Valley to Southeast, and eastern Great Lakes to New England. Outside of the CONUS, eastern parts of Alaska were wetter than normal with near to warmer-than-normal temperatures, while western parts were cooler and drier than normal. Most of Hawaii was drier than normal, while drier- and warmer-than-normal conditions dominated Puerto Rico and the U.S. Virgin Islands.
Drought and abnormal dryness contracted in Montana, from the New Mexico area to southern Lake Michigan, and in Virginia where above-normal precipitation fell. But drought or abnormal dryness developed, expanded, or intensified where it continued dry, especially in parts of Wyoming, Texas, the Upper-Midwest and northern Plains, the Tennessee Valley to Appalachians, and much of the Northeast.
Nationally, contraction was more than expansion, so the nationwide moderate to exceptional drought area percentage decreased this week. But the worst drought conditions (extreme to exceptional drought) increased in area this week. Abnormal dryness and drought are currently affecting over 201 million people across the United States including Puerto Rico—about 64.6% 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 X.
