According to the September 17, 2024 U.S. Drought Monitor (USDM), moderate to exceptional drought covers 29.8% of the United States including Puerto Rico, an increase from last week’s 28.8%. The worst drought categories (extreme to exceptional drought) increased from 2.0% last week to 2.3%.
A ridge of high pressure tried to maintain its grip across the contiguous U.S. (CONUS) during this USDM week (September 11–17), but it was assaulted from the west by upper-level troughs of low pressure and by tropical systems in the south and east. The ridge generally inhibited precipitation and worked to keep temperatures warmer than normal. But cold fronts and surface low-pressure systems associated with the western troughs brought above-normal precipitation to parts of the Pacific Northwest, Great Basin, and northern Rockies and Plains, as well as cooler-than-normal temperatures to the West Coast states.
Meanwhile, Hurricane Francine and its remnants barreled into the central Gulf of Mexico coast, bringing wetter- and cooler-than-normal weather to the Gulf Coast states and as far north as the Mid-Mississippi Valley. Near the end of the USDM week, Potential Tropical Cyclone 8 (PTC-8) did the same as it moved ashore in the Carolinas. Aside from these wet areas, much of the CONUS was drier than normal, with large parts of the Southwest, southern Plains to Great Lakes, and Northeast regions receiving no precipitation.
The Great Plains and Great Lakes to the Northeast regions ended up warmer than normal, with the warmest temperature anomalies occurring in the northern Plains to the Upper Mississippi Valley. Alaska was warmer than normal with a mixed precipitation anomaly pattern. In Hawaii, the Big Island was mostly wetter than normal whereas the other main islands were drier than normal. A ridge brought warmer- and drier-than-normal weather to Puerto Rico while the U.S. Virgin Islands had a wet week.
Drought and abnormal dryness contracted in the South under Francine’s rains and in the northern Rockies, but expanded or intensified in the Plains, Midwest, Northeast, and parts of South Carolina missed by the rains of PTC-8.
Nationally, expansion was more than contraction, so the nationwide moderate to exceptional drought area percentage increased this week. Abnormal dryness and drought are currently affecting over 168 million people across the United States including Puerto Rico—about 54.2% 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.
