According to the January 2, 2024 U.S. Drought Monitor, moderate to exceptional drought covers 27.6% of the United States including Puerto Rico, an increase from last week’s 27.1%. The worst drought categories (extreme to exceptional drought) slightly decreased from 5.4% last week to 5.3%.
A strong ridge of high pressure dominated the upper-level atmospheric circulation across most of the contiguous U.S., especially in the West, during this U.S. Drought Monitor (USDM) week (December 27–January 2). But equally-powerful troughs of low pressure competed against the ridge. One upper-level low-pressure system dominated the eastern contiguous U.S. during the first half of the week, while a couple weaker ones moved across the ridge to the north and a couple others undercut the ridge by moving across it in the south. The ridge kept most of the contiguous U.S. dry, with warmer-than-normal temperatures along the West Coast and across the northern states.
The troughs brought near- or cooler-than-normal weekly temperatures to the Southwest and across the Gulf of Mexico states. The ridge blocked the moisture supply to the troughs so they were generally moisture-starved and created above-normal precipitation in only a few areas—along the California coast, in small parts of the northern Plains to Midwest, and from the Carolinas to Northeast.
High pressure dominated Hawaii and the Caribbean, so the week was drier than normal in Hawaii, Puerto Rico, and the U.S. Virgin Islands.
Drought or abnormal dryness contracted or was reduced in intensity over parts of New Mexico, the central Great Plains, southern Great Lakes, and southern Appalachians to Mid-Atlantic states. Drought or abnormal dryness expanded or intensified in areas that have seen persistently dry conditions, especially in parts of the West, Ohio Valley, and southern Plains to eastern Gulf of Mexico coast.
Nationally, expansion was more than contraction, so the nationwide moderate to exceptional drought area increased this week. Abnormal dryness and drought are currently affecting over 122 million people across the United States including Puerto Rico—about 39.3% 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 as well as 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 and the U.S. Department of Agriculture provides information about the drought’s influence on crops and livestock.
For additional drought information, follow #DroughtMonitor on Facebook and Twitter.
