December 2009 Climate Summary

For a printable version of the climate summary which includes more figures, data tables, and state summaries, click here. 

Region Breakdown

December 2009 was cold and wet across the much of the High Plains Region. Moisture was variable across the Region this month as precipitation totals of 25% of normal or less were common across areas of southern Kansas, western Wyoming, and western North Dakota while locations such as Nebraska and South Dakota received over 400% of normal precipitation. Meanwhile, each state in the Region had monthly average temperature departures as low as 8˚F to 10˚F (4.4˚C to 5.5˚C) below normal. There were also isolated pockets greater than 10˚F (5.5˚C) below normal.

This month’s cold location was Lodgepole, NE which had its second coldest December on record with an average temperature of 18.5˚F (-7.5˚C). While the average temperature for the month was 11˚F (6.1˚C) below normal it was not enough to beat the old record that occurred in 1983 when Lodgepole had an average temperature of only 13.8˚F (-10.1˚C).

Precipitation Summary

December 2009 was extremely wet across the Region as areas of Kansas, Nebraska, and South Dakota received record breaking snowfall. Two major snowstorms hit the Region this month. The first occurred December 7-9 and the second occurred December 23-26. Not only did each storm drop over a foot of snow in locations across Kansas, Nebraska, North Dakota, and South Dakota, but high winds coupled with the snowfall created blizzard and white out conditions. In addition, these storms caused school closures, highway closures, power outages, and travel delays.

While many monthly records were broken this month, there were two locations which crushed their old December records, Norfolk, NE and Sioux City, SD. In addition to breaking several daily snowfall totals, Norfolk broke its December snowfall and snow depth records. Norfolk received 30.4 inches (77.22 cm) of snow which beat out the old record of 19.1 inches (48.51 cm) received in 1968. The snow depth record of 17 inches (43.18 cm), also recorded in 1968, was broken when the snow depth was 19 inches (48.26 cm) from December 27-31. Sioux City also broke daily snowfall records, the December snowfall record, and the December snow depth record. Sioux City received 34.0 inches (86.36 cm) of snowfall which easily beat the old record of 22.6 inches (57.40 cm) recorded in 2008. By the end of the month the snow depth was 20 inches (50.80 cm) which topped the old record of 16 inches (40.64 cm) which also occurred in 2008.

In contrast to the record breaking snow, areas including southern Kansas, portions of Wyoming, and western North Dakota were dry. Liberal, KS, which received no precipitation this month, tied for the driest December on record (1893-2009). These dry conditions have led to the development of abnormally dry conditions in western North Dakota and western Wyoming.

Climate Outlook

El Niño conditions were present this month and are expected to continue and last through Spring 2010. The temperature outlook indicates a higher probability of above normal temperatures for the Dakotas, Nebraska, Wyoming, northern Kansas, and the northern half of Colorado. Equal chances of above, near, or below normal temperatures are predicted elsewhere. The precipitation outlook indicates a higher probability of above normal precipitation for most of Kansas, the majority of Colorado, southwestern Nebraska, and a very small portion of southeast Wyoming. Only a very small portion of the northwest corner of Wyoming has a higher probability of below normal precipitation. Equal chances of above, near, or below normal precipitation are predicted elsewhere in the Region. The seasonal outlooks combine the effects of long-term trends, soil moisture, and when applicable, the El Niño Southern Oscillation (ENSO) cycle. More information about these forecasts can be found here.

Drought Watch

There were minor changes to the U.S. Drought Monitor for the High Plains Region this month. South Dakota, Nebraska, and Kansas remained drought free and abnormal dryness (D0) and moderate drought (D1) conditions remained largely the same across Colorado. However, abnormally dry (D0) conditions have developed in western Wyoming and western North Dakota, due to a low snowpack and low precipitation totals over the past few months, respectively. According to the U.S. Seasonal Drought Outlook released December 19th, the drought conditions in the southwest corner of Colorado are expected to improve while drought conditions are expected to develop in northeast Wyoming and northwest North Dakota through March 2010.