Drought expansion in Montana
Much of Montana and parts of the Dakotas, Nebraska, and Kansas had no rain this week; some areas have been drier than normal for the last 2 to 3 months; and some drought indicators reflect dryness for the last 12 months. D3-D4 were expanded in northeast Montana, and D3 expanded in northwest South Dakota and was added in southeast South Dakota, where the Standardized Precipitation Index (SPI) was consistently at those dry levels for the last 1 to 9 months. D1-D4 expanded in northwest North Dakota where the SPI was consistently at those dry levels for the last 1-6 months. D0-D2 expanded across much of Nebraska, with collateral expansion of D1-D2 in adjacent South Dakota, D1 in adjacent Iowa, and D0-D1 in southeast Wyoming, and D0 expanded in parts of eastern Kansas and northeast Colorado, due to 30-90 day precipitation deficits and high evapotranspiration caused by excessive heat. Governors provided much-needed response to the dire drought impacts.
Montana Gov. Steve Bullock issued an executive order declaring a drought disaster in 28 counties and five Indian reservations in the eastern part of the state. Nebraska Gov. Pete Ricketts issued an emergency proclamation, allowing the state Emergency Management Agency to address unmet drought needs, particularly those related to wildfires. According to July 23rd USDA reports, 92% of the topsoil moisture and 88% of the subsoil moisture were rated short or very short in Montana, 82%/81% of the topsoil/subsoil moisture was short or very short in South Dakota, 71%/66% in Nebraska, 67%/62% in North Dakota, 61%/58% in Wyoming, and 45%/41% in Colorado. More than half of the pasture and rangeland were rated in poor to very poor condition in North Dakota (75%), South Dakota (73%), and Montana (56%). In South Dakota, 37% of the corn crop, 34% of soybeans, 57% of sorghum, and 76% of the spring wheat were in poor to very poor condition. In North Dakota, 23% of the corn crop and 39% of the spring wheat were in poor to very poor condition. In Montana, 55% of the spring wheat was in poor to very poor condition. According to media reports, as of July 25th, the Lodgepole Complex wildfire in Montana was the largest wildfire in the CONUS.
D0 … Abnormally Dry … used for areas showing dryness but not yet in drought, or for areas recovering from drought.
Drought Intensity Categories
D1 … Moderate Drought
D2 … Severe Drought
D3 … Extreme Drought
D4 … Exceptional Drought
Drought or Dryness Types
S … Short-Term, typically <6 months (e.g. agricultural, grasslands)
L … Long-Term, typically >6 months (e.g. hydrology, ecology)
Source: U.S. Drought Monitor