December 2017 Climate Summary Now Available

Widespread Dryness Leads to Drought Expansion

Precipitation was scarce throughout much of the High Plains during December, especially in Colorado and Kansas. Numerous locations had a top 10 driest December on record and these conditions were, in large part, a continuation of dryness since around mid-October. These dry conditions have contributed to widespread below-normal snowfall across the region, particularly in the Rockies of Colorado where the snowpack season was off to an abysmal start. A combination of these factors led to the expansion of abnormally dry conditions and drought during December, according to the U.S. Drought Monitor. While drought impacts tend to be minimal this time of year, dry soils and below-normal precipitation during winter often lead to impacts during the spring. The only state in the region that was spared from dry conditions was Wyoming, where above-normal precipitation continued to boost snowpack. As for temperatures, most of the region had normal to slightly above normal temperatures for December on the whole; however, early to mid-December was extremely warm while late December was extremely cold.

Warm, dry, and windy conditions also contributed to the spread of wildfires in December, which is outside the typical fire season in the High Plains. The most notable fire was the Legion Lake Fire, which burned over 54,000 acres and became the third largest on record in both the Black Hills and the state of South Dakota. The fire ravaged Custer State Park and threatened wildlife, such as bison, deer, and elk. The fire also damaged fences, trails, and roads, forcing the park to close temporarily to make repairs. According to Darren Clabo, South Dakota State Fire Meteorologist, the Legion Lake Fire behaved more like a summer fire in that there was high crown mortality and areas were burned beneath the overstory on the surface. Clabo stated that the ongoing drought in the area likely played a role in the large number of acres burned because heavier fuel types would have to be dry enough to burn, and that would only happen if there had been a prolonged period of precipitation deficits.

For more information on temperature, precipitation, and impacts from climate in December in the High Plains region, please see the link to the full PDF of the summary: https://hprcc.unl.edu/climatesummaries.php