According to the November 7, 2023 U.S. Drought Monitor, moderate to exceptional drought covers 31.5% of the United States including Puerto Rico, an increase from last week’s 30.7%. The worst drought categories (extreme to exceptional drought) increased from 6.6% last week to 7.2%.
The atmospheric circulation over the contiguous U.S. during this U.S. Drought Monitor week (November 1–7) consisted of an upper-level ridge of high pressure across the western half of the CONUS and an upper-level trough of low pressure over the eastern half of the country. This pattern resulted in warmer-than-normal weekly temperatures over the West and into the central Plains, with colder-than-normal weekly temperatures to the East. Pacific weather systems brought above-normal precipitation to the Pacific Northwest as they moved ashore. But the overall jet-stream flow was westerly and this kept the storm track mostly across the northern states. The weather systems were dried out as they moved across the Rockies, and the overall atmospheric circulation pattern blocked Gulf of Mexico and Atlantic moisture. Thus, the cold fronts that moved east of the Rockies brought mostly dry air masses behind them. Consequently, little to no precipitation fell across the Southwest and most of the country east of the Rockies. The North Pacific High-Pressure system kept Hawaii drier than normal. Most of Puerto Rico was drier than normal for the week, while a mixed precipitation anomaly pattern occurred over Alaska and the U.S. Virgin Islands.
Drought or abnormal dryness contracted or was reduced in intensity in parts of the Pacific Northwest and northern Plains. But another dry week prompted expansion or intensification of drought and abnormal dryness in parts of the Southwest, areas from the Mississippi River to the Gulf and East Coast, and in Hawaii.
Nationally, expansion exceeded contraction, so the nationwide moderate to exceptional drought area increased this week. Abnormal dryness and drought are currently affecting over 159 million people across the United States including Puerto Rico—about 51.1% of the population.
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.