John McGinley, Boulder County. December 2018 suffered from low precipitation unlike the previous two months. Only six inches of snow fell over the month with the biggest single event at 2.5 inches. The month was dominated by strong westerly flow and snow blow-off over the divide. This rarely results in big snowstorms. Winds were common, as they usually are, in December with 13 days at 40+mph and 3 over 60mph. Temperatures were right near normal with generally cool conditions in the first and last weeks and mild in the middle two weeks.

Precipitation: Snowfall was an abysmal 6.7 inches 33 percent below normal. The liquid equivalent was 0.33 inches. Two big events were 2.6 inches on Dec. 5-6 and 1.9 inches on New Year’s Eve.

Temperature: Average high was 32.1 degrees F with an average low of 17.3F This put the mean temperature 0.3 degrees below normal. This is the third month in a row colder than average. The warmest high was 47F on the 16th, the coldest high was 15F on the 28th. The coldest day had a low -8F on the 31st.

Winds: December was windy, with 13 days at 40+mph and three days over 60mph. Peak wind was 65mph on the 21st.

Other features: Lots of westerly flow, but very few strong storms. Cyclones went to our north and to the south, bypassing the Front Range.

Outlook for January: More westerly flow is likely through the first half of the month. In the second half we will open the door to some more significant storms. Temperatures will be slightly above normal. Normal highs are 34F and 15F. Precipitation typically comes as 16 inches of snow melting out to about an inch of moisture. It will be windy with 14 days at 40+mph and 5 of those days at 60+mph.