U.S. Drought: Weekly Report for November 12, 2024

According to the November 12, 2024 U.S. Drought Monitor (USDM), moderate to exceptional drought covers 41.7% of the United States including Puerto Rico, a decrease from last week’s 43.4%. The worst drought categories (extreme to exceptional drought) slightly increased from 4.0% last week to 4.1%.

The upper-level circulation pattern over the contiguous U.S. (CONUS) during this USDM week (November 6–12) consisted of a battle between a ridge of high pressure that dominated much of the CONUS and southern Canada, on the one hand, and low-pressure systems that made inroads into the western CONUS, on the other hand. The ridge kept temperatures warmer than normal, especially east of the Rockies, and precipitation below normal for much of the CONUS for most of the week. An upper-level trough of low pressure punched into the ridge in the West and became a cutoff low, spending much of the week moving very slowly over the southwestern CONUS. The low brought cooler-than-normal temperatures to the southwestern fourth of the nation. A southerly flow ahead of the low tapped Gulf of Mexico moisture, which fed above-normal precipitation that fell across New Mexico and northern Texas to parts of the Dakotas. Temperatures were below freezing, so the precipitation fell as heavy snow over parts of New Mexico and Colorado. Meanwhile, surface cold fronts and low-pressure systems moved across the eastern CONUS. They were weakened by the high-pressure ridge, but were still able to produce areas of above-normal precipitation from the Lower Mississippi Valley to Ohio Valley and across parts of the coastal Southeast. The eastern ridge also caused Hurricane Rafael to meander over the Gulf of Mexico, sparing the nation another hurricane landfall, until it weakened into a remnant low. As the week ended, another upper-level weather system began entering the West, bringing mountain snow to the Cascades and Sierra Nevada. 

Alaska was mostly drier than normal, while Puerto Rico and the U.S. Virgin Islands had a wetter-than-normal week. A cold front brought rain to parts of Hawaii, but most of the state had a drier-than-normal week.        

Drought and abnormal dryness contracted or reduced in intensity from the central and southern Rockies to the Ohio and Lower Mississippi Valleys, and over parts of Georgia and South Carolina, where above-normal precipitation fell. It expanded or increased in intensity across parts of southern California to southern Texas, and over parts of the Southeast to the Northeast, where the weather continued dry and, in the east, warmer than normal. Nationally, contraction was more than expansion, so the nationwide moderate to exceptional drought area percentage decreased this week, although the area experiencing extreme to exceptional drought increased.

Abnormal dryness and drought are currently affecting over 237 million people across the United States including Puerto Rico—about 76.4% of the population.