This week’s U.S. Drought Monitor saw changes to over 30 states. Record-breaking heat in the Northwest, Great Basin, and Northeast led to expansions of drought conditions. Meanwhile, multiple rounds of heavy rain across the Central U.S. led to large-scale improvements, and intense rainfall along the Gulf Coast led to the reduction or removal of lingering pockets of abnormal dryness.
High Plains
The same stalled frontal boundary that affected the Lower Midwest this week also brought widespread rain to the region with the largest totals (2 to 8-plus inches) falling over eastern Kansas and eastern Nebraska. One-category improvements were made in southeast Kansas, eastern and north central Nebraska, and parts of North Dakota as short-term rainfall deficits decreased and streamflow and soil moisture improved. In Colorado, improvements were made to small areas of exceptional (D4) and extreme (D3) drought as recent rainfall has helped chip away at shorter term deficits.
Hydrological and ecological drought, which generally occur on longer time scales, remain a concern. In areas that missed out on the heaviest rain, drought continues to impact the region with cattle producers feeling the brunt of the impacts. The USDA reports that 90% of South Dakota and 66% of North Dakota’s topsoil moisture is short to very short, leading to forage shortages. Producers from Wyoming eastward across the Dakotas are having to make tough decisions as to what to do with cattle, with many selling entire herds. In response to the worsening conditions, extreme drought (D3) expanded in South Dakota and parts of Wyoming where supported by increasing rainfall deficits, declining soil moisture and streamflow, and vegetation stress.
South
A band of substantial rain (6 to 10-plus inches) fell from West Texas to northeast Oklahoma, leading to large areas of one-category improvements as well as some smaller areas of two-category improvements as short-term rainfall deficits, soil moisture, and streamflow improved. Drought and abnormal dryness remain in areas where indicators still show dryness at longer timescales. A re-evaluation next week will help determine the full effect of the rainfall.
Midwest
A stalled frontal boundary brought widespread, heavy rain (3 to 10-plus inches) and flash flooding to parts of the lower Midwest. The excess moisture led to a general one-category improvement to drought conditions as short-term rainfall deficits decreased and streamflow and soil moisture improved. In the Upper Midwest, which mostly missed out on the heaviest rain, drought remains a concern. In Minnesota, the U.S. Department of Agriculture (USDA) reports as of June 27, that 75% of the state’s topsoil moisture is short to very short, meaning that it’s significantly less than what is required for normal plant development. While crops can still improve with additional rain, the damage has already been done to pastures. Abnormal dryness (D0) expanded in Minnesota and moderate drought (D1) expanded in northern Illinois.
West
Unprecedented heat in the Northwest, combined with another week of dry weather, led to worsening drought conditions across the region. This week, high temperatures ranged from 20 to 30 degrees above normal, breaking multiple records. The excess heat greatly increased evaporative demand, further drying out soils and vegetation, and worsening conditions. Many areas in the Northwest saw one-category degradations, including expansions of severe (D2) and extreme (D3) drought. Conditions in the Southwest remained unchanged, except for the expansion of D3 in central Arizona. Much of the West is classified as severe drought or worse.
Notable impacts include increased wildlife encounters in California, Nevada, and Utah, as drought has driven snakes and/or bears in search of food and water into urban areas in those states. In Montana, fishing restrictions have been put in place on many rivers due to low flows and warm waters. Drought-stricken ranchers are selling cattle due to poor forage conditions and a lack of feed. On top of this, grasshoppers have been denuding trees and competing with cattle for food. So far, at least eight national forests in the West now have fire restrictions.
Looking ahead
The National Weather Service Weather Prediction Center forecast for the next five days (July 1 to 4) shows that the prolonged heat wave is expected to continue across the interior sections of the Northwest and Northern Rockies and move into the Northern High Plains. In the East, a cold front is forecast to bring relief from the hot, muggy weather in the Northeast, Mid-Atlantic, and Southeast. As the front moves through the region, these areas can expect moderate to heavy rainfall and an increased chance of severe weather.
Moving into next week, the Climate Prediction Center six-to-10 day outlook (valid July 6-10) favors above normal temperatures across the West, Northern and Central Plains, Midwest, and Northeast. Below normal temperatures are most likely across the South, Southeast, and Alaska. Below normal precipitation is expected to continue across much of the west and Northern Plains, while above normal precipitation is favored across most of the rest of the Lower 48 and Alaska.
