7/18/17 Drought Monitor - Northern Plains Drought Intensifies, Wheat And Pasture Burning Up

[hatrack]

Locally heavy rains fell in southern parts of the High Plains, with over 3 inches reported at several stations in southeast Colorado and southern Nebraska. A few stations in the Dakotas and Kansas received an inch or more of rain this week, but the showers and thunderstorms were spotty and amounts varied significantly. Most stations in the region were drier than normal this week with many receiving a tenth of an inch of rain, if any. With daily temperatures exceeding 90 degrees F, the 7-day average maximum temperature was above 90 in a band from Montana to Kansas. The excessive heat increased evapotranspiration, as reflected in the extreme ESI and EDDI values, and further dried soils which were already parched. According to July 17 USDA reports, topsoil and subsoil moisture was short to very short across 88%/80% (topsoil/subsoil) of Montana, 85%/79% of South Dakota, 65%/58% of North Dakota, 65%/57% of Nebraska, and 62%/58% of Wyoming.

The heat and dryness have ravaged crops, with 61% of the spring wheat crop in poor to very poor condition in Montana and 40% in North Dakota. In South Dakota, 74% of the spring wheat was in poor to very poor condition, 38% of the corn crop, 33% of soybeans, and 45% of sorghum. The pasture and rangeland statistics (in poor to very poor condition) were 74% for North Dakota, 68% for South Dakota, 58% for Montana, and 26% for Nebraska. As noted by the North Dakota State Climatologist, the spotty rains might have been enough to green-up the vegetation, but not enough to increase the vegetative volume.

Reports from the field include many reports of extensive drop damage, livestock water holes drying up, and cattle losing weight due to poor or nonexistent grazing land. The South Dakota State Climatologist reported that corn is in tasseling stage now; under drought stress, this can lead to an 8% yield loss per day, which is the highest rate of yield loss of any crop stage.

The agricultural impacts were compounded by low streamflows. According to the Bureau of Indian Affairs, the Ft. Peck and Ft. Belknap Tribes in Montana declared disaster emergencies in June that remain in effect; the Rocky Boy's reservation, south of Havre, is experiencing drastic water shortages; and several Tribes in the eastern part of Montana have enacted burn bans.

With many indicators, such as SPI, EDDI, ESI, and soil moisture, converging to exceptionally dry conditions, spots of D4 were added to the USDM depiction in Montana and North Dakota. D0-D3 were expanded in the Dakotas with collateral expansion in adjacent states (Nebraska, Iowa, and Minnesota). D0-D1 were expanded in Nebraska and Kansas, but D0-D1 were trimmed in other parts of Nebraska and Kansas where an inch to several inches of rain fell.