Nationwide
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A robust Southwestern monsoon circulation delivered drought-easing rainfall. Still, it sparked localized flash flooding across large sections of the Four Corners states and the southern Great Basin. Critically dry conditions persisted across northern California and the Northwest. In the driest areas, wildfires—some sparked by lightning—dotted the landscape, with containment of some blazes hampered by high temperatures, low humidity levels, erratic winds, and abundant fuels.
Farther east, another round of blistering heat across the northern Plains further stressed rangeland, pastures, and a variety of summer crops. The central and southern Plains also experienced some hot weather, although mostly adequate soil moisture reserves tempered agricultural impacts.
Meanwhile, mostly dry weather covered the Midwest, continuing a trend that had developed in mid-July. Short-term dryness was not yet a concern in the previously well-watered lower Midwest. However, reproductive corn and soybeans in drier areas of the upper Midwest were subjected to increasing levels of stress, especially as temperatures began to rise. Elsewhere, Southeastern rain—which maintained abundant moisture reserves for pastures and summer crops—primarily fell from the Mississippi Delta to the southern Atlantic Coast.
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The West
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Further expansion of moderate to exceptional drought (D1 to D4) was introduced in parts of California and the Northwest, as agricultural, wildfire, and water supply impacts continued to mount. Oregon’s third-largest wildfire in modern history, the Bootleg Fire, has burned more than 410,000 acres of timber and brush, but was more than 50 percent contained.
California’s largest active blaze, the Dixie Fire, has scorched nearly 220,000 acres only about 15 miles northeast of the town of Paradise, which was devastated by the Camp Fire in 2018. Washington continued to lead the country in several drought-related agricultural categories, according to the U.S. Department of Agriculture, including topsoil moisture rated very short to short (99 percent on July 25), as well as very poor to poor ratings for rangeland and pastures (97 percent) and spring wheat (88 percent).
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In addition to Washington, at least two-thirds of the rangeland and pastures were rated very poor to poor on July 25 in Montana (91 percent), Arizona (82 percent), Oregon (80 percent), and Utah (69 percent). Montana rivaled Washington for agricultural drought severity, with topsoil moisture rated 97 percent very short to short and a nation-leading 70 percent of its barley rated very poor to poor. Farther south, however, an active monsoon circulation delivered drought relief in the form of diurnal showers and thunderstorms, some heavy. Up to one category of improvement was introduced in parts of Arizona, New Mexico, southwestern Colorado, and southern sections of Utah and Nevada.
In Arizona, Tucson received more rain in 6 days (4.20 inches fell from July 20-25) than during all of 2020, when annual precipitation of 4.17 inches was the lowest on record. Despite the positive effect of monsoonal showers on surface conditions (e.g., improved vegetation health, topsoil moisture, and streamflow), serious long-term, underlying drought persisted, with obvious impacts on groundwater and reservoirs.
The surface elevation of Lake Mead, on the Colorado River behind Hoover Dam, fell to a new record low—1,067.59 feet above sea level—on July 23. In Utah, the surface elevation of the Great Salt Lake fell below 4,191.4 feet in late July, breaking the previous record low set in 1963.
The High Plains
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Drought’s footprint remained rather limited across Kansas, eastern Colorado, and southern Nebraska. Farther north and west, however, worsening drought impacts were observed across much of Wyoming and the Dakotas.
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According to the U.S. Department of Agriculture, topsoil moisture on July 25 was rated 87 percent very short to short in North Dakota, along with 82 percent in South Dakota and 79 percent in Wyoming. Rangeland and pastures were rated at least 60 percent very poor to poor in Wyoming and the Dakotas, led by North Dakota at 85 percent. On July 25, North Dakota was the national leader in oats rated very poor to poor (56 percent), along with soybeans (41 percent) and corn (39 percent).
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Among major production states, South Dakota led the nation in sorghum rated very poor to poor (31 percent). Nationally, the U.S. spring wheat crop was rated just 9 percent good to excellent and 66 percent very poor to poor on July 25, the lowest overall condition at this time of year since July 25, 1988, when the crop was categorized as 4 percent good to excellent and 72 percent very poor to poor.
Harvest was underway for drought-ravaged crops on the High Plains; 3 percent of the spring wheat had been cut by July 25. Periodic extreme heat on the northern Plains has greatly aggravated drought impacts. During the most recent heatwave, high temperatures in South Dakota on July 27 soared to 108°F in Pierre and 107°F in Rapid City. In the latter location, that represented the highest temperature since August 29, 2012. — UNL Drought Monitor
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