The upper-level circulation over the contiguous U.S. during this U.S. Drought Monitor week (May 24-30) was dominated by three features: a trough over the West, a ridge that extended from the southern Plains to the Great Lakes, and a cutoff low over the Southeast.
A southerly flow over the Plains was created between the western trough and eastern ridge. This flow funneled Gulf of Mexico moisture across the Plains. The moisture fed thunderstorms and weather complexes that developed along the stalled-out fronts and dry lines, resulting in above-normal precipitation across western portions of the Great Plains from Texas to Montana.
Locally heavy rain fell over western parts of the High Plains region while eastern parts had a dry week. Continued dry conditions in the eastern portions of the region resulted in expansion of abnormal dryness or moderate drought in the Dakotas, abnormal dryness to extreme drought in eastern Kansas, and severe to exceptional drought in eastern Nebraska.
Based on May 28 USDA data, 69% of the winter wheat crop in Kansas and 51% in Nebraska was in poor to very poor condition, and more than 40% of the topsoil moisture was short or very short in Nebraska (57%), Kansas (50%), and South Dakota (46%). More than two-thirds of the subsoil moisture was short or very short in Nebraska (75%) and Kansas (68%).
Some rain fell at the northwest and southeast ends of the Midwest region this week, but most of the region received no precipitation. D0 expanded across most of the region; D1 grew in Illinois, Iowa, and Missouri; D2 (severe drought) expanded in Iowa and Missouri; and D3 grew in Missouri. Soils rapidly dried across the Midwest.
As of May 28, USDA data revealed more than half of the topsoil moisture was short or very short in Iowa (50%), Missouri (62%), and Michigan (68%), and 40% or more was short or very short in Wisconsin (45%), Ohio (45%), Illinois (42%), and Indiana (40%).
U.S. Drought Monitor
