According to the January 16, 2024 U.S. Drought Monitor, moderate to exceptional drought covers 24.1% of the United States including Puerto Rico, a decrease from last week’s 26.7%. The worst drought categories (extreme to exceptional drought) decreased from 4.5% last week to 4.1%.
The atmospheric circulation over North America shifted during this U.S. Drought Monitor week (January 10–16). The upper-level ridge of previous weeks was replaced by a huge upper-level trough over virtually the entire continent. The trough funneled frigid arctic air into the contiguous U.S., resulting in much-below-normal temperatures for all of the country except the East Coast. The coldest air was in the central to northern Plains, which bore the brunt of the cold fronts.
A series of Pacific weather systems pummeled the Pacific Northwest with rain and wintry weather. As the systems moved east, they spread their blanket of above-normal precipitation from Oregon to Nebraska. East of the Rockies, they tapped Gulf of Mexico and Atlantic moisture to give the Midwest and much of the eastern contiguous U.S. above-normal precipitation. Strong winds accompanied the rain, snow, ice, and bone-chilling temperatures. Parts of the northern tier states from Washington to Minnesota, and most of the southern tier states from California to Alabama, were away from the main storm track, so these areas were drier than normal for the week.
High pressure dominated the Caribbean, keeping the week warmer and drier than normal in Puerto Rico and the U.S. Virgin Islands. Hawaii was mostly cooler than normal with a mixed precipitation anomaly pattern, while Alaska was mostly warmer than normal (except cooler than normal in the panhandle) with a mixed precipitation anomaly pattern. In the western Pacific, abnormal dryness and drought rapidly spread across Micronesia as the El Niño inhibited precipitation over the region. Drought or abnormal dryness contracted or was reduced in intensity over parts of the Pacific Northwest, central Rockies, and Hawaii, and much of the Mid-Mississippi Valley to the Appalachians.
Drought or abnormal dryness expanded or intensified in areas that have seen persistently dry conditions, especially in parts of the northern Rockies, Arizona, southern Texas, and Puerto Rico. Nationally, contraction was more than expansion, so the nationwide moderate to exceptional drought area decreased this week.
Abnormal dryness and drought are currently affecting over 96 million people across the United States including Puerto Rico—about 31.1% 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 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.
