Weekly High Plains Drought Update - December 21, 2017

Persistent Dryness Leads to Expansion of Drought, Abnormally Dry Conditions

It was another dry week across a large portion of the High Plains region, leading to additional expansion of abnormally dry (D0) and moderate drought (D1) conditions on the U.S. Drought Monitor map. With the exception of northern and central Wyoming and pockets of North Dakota, much of the region received less than 50 percent of normal precipitation over the past 7 days. According to the December 19, 2017 U.S. Drought Monitor, the area experiencing abnormal dryness or drought (D0-D4) increased from about 77 percent to 81 percent. Part of this increase can be attributed to the expansion of D0 in southeastern Wyoming, western Nebraska, and extreme southeastern Nebraska/northeastern Kansas. As a result of this expansion, the entire state of Kansas is now in D0 or worse. D1 was also expanded eastward to include more of western Colorado where snowpack continues to suffer. As of December 21st, statewide Snow Water Equivalent (SWE) was only 48%, with southern basins in Colorado faring the worst. Temperatures continued to be above normal this past week throughout the entire region, particularly across the Dakotas where they exceeded 12°F above normal in some places. The depiction of drought in the western Dakotas where drought has persisted since the early summer remained unchanged this week.

A major pattern change is on tap for the next week, with colder air arriving before the Christmas holiday for much of the High Plains. According to the 6-10 day outlook, confidence is high that below-normal temperatures will occur throughout the High Plains, with the exception of southwestern Wyoming and the southwestern half of Colorado. In fact, extreme southwestern Colorado is expected to have above-normal temperatures, which will not help the snowpack situation. Wetter conditions are expected throughout a large part of the region except for the northeastern half of North Dakota and western Colorado. Below-normal precipitation is favored for extreme northeastern North Dakota. The 7-day Quantitative Precipitation Forecast indicates higher amounts of precipitation in the Rockies in western Wyoming and northern Colorado, as well as southeastern Wyoming. Much of Nebraska, southern South Dakota, and northern Kansas are expected to receive up to a quarter inch of precipitation as a storm system is expected to impact the region over the next few days.

Note: Due to the University of Nebraska winter break shutdown, the HPRCC will not publish a drought update next week. However, a U.S. Drought Monitor map will be published, so please visit the U.S. Drought Monitor website for changes in drought conditions: http://droughtmonitor.unl.edu/