According to the October 17, 2023 U.S. Drought Monitor, moderate to exceptional drought covers 33.2% of the United States including Puerto Rico, a decrease from last week’s 33.6%. The worst drought categories (extreme to exceptional drought) decreased from 7.5% last week to 7.3%.
The atmospheric circulation over the contiguous U.S. during this U.S. Drought Monitor (USDM) week (October 11–17) consisted of an upper-level ridge of high pressure across the western contiguous U.S. that extended from the Southwest into central Canada. Upper-level troughs of low pressure were located across Alaska and over the east coast of North America stretching from eastern Canada to Florida. The ridge brought warmer-than-normal weekly temperatures to parts of the West, while the eastern trough kept temperatures cooler than normal for much of the contiguous U.S. east of the Rockies. The ridge generally inhibited precipitation.
A Pacific weather system undercut the ridge, with its cold front and surface low pressure bringing above-normal precipitation to coastal areas of the Pacific Northwest and in a band stretching from Wyoming to the Great Lakes. Another low-pressure system and its cold front spread above-normal precipitation across parts of the Southeast. Otherwise, much of the West, southern and northern Plains, Lower Mississippi to Ohio Valleys, and New England were drier than normal.
Subtropical high pressure kept Hawaii, Puerto Rico, and the U.S. Virgin Islands drier than normal this week. Above-normal precipitation contracted drought or reduced its intensity in the Pacific Northwest, central Plains to western Great Lakes, and along the Gulf of Mexico coast. But continued dry conditions expanded or intensified abnormal dryness and drought in parts of Hawaii and the southern Plains, and from the Lower and Mid-Mississippi Valley to southern Appalachians.
Nationally, contraction exceeded expansion for the contiguous U.S., so the nationwide moderate to exceptional drought area decreased this week. Abnormal dryness and drought are currently affecting over 151 million people across the United States including Puerto Rico—about 48.6% 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 Twitter.
