John McGinley, Peak to Peak.  January 2018 continued the warm, dry and windy conditions seen in December. The month was notable not only for the 21 windy (40mph+) days but for their intensity, with several days of gusts between 80-100 mph in locations throughout the foothills. Many a tree came down and some folks suffered roof damage. The culprit was the continued northwest flow brought on by a warm west coast ridge and a super cold eastern trough.

This pattern keeps us flirting with cold arctic air on the plains, low pressure troughs just east of the Rockies, and higher pressure over the Great Basin. The combination creates perfect conditions for intense winds. Unfortunately, it is a dry flow accounting for our paltry 0.75 inches of liquid and 10 inches of snow for the month. The only “big” event we had was a 7-8 inch snow on the 21st. At night the windy conditions don’t allow for the typical radiational cooling, so our lows were much above normal, making the month’s average temperature 6 degrees above normal. We had seven days where the temperature never went below freezing, unheard of when you think of the old days.

Precipitation: Total for the month was 0.75 inches, 0.17 inches below normal. Snow totaled 9.5 inches, 6 inches below normal.

January precipitation is highly variable, so this kind of deficit is not rare.

Temperature: Average high for the month was 37.6 and the average low was 23.2. The former was 3 degrees above normal and the latter was an astounding 9 degrees above normal. Combining the high and low we saw a mean temperature 6 degrees above normal, putting this month in the top 15% of warm Januarys. Highest temperature for the month was 50F on the 19th and the lowest low was 1F on the 15th and 16th. Can you believe a January that didn’t go below zero?

Winds: As we said upfront winds were again the big story for the month. 21 days went over 40mph with 5 days 60mph or over.

This put the month in the top 8% of all windy Januaries. My peak wind for the month was 82mph on the morning of the 28th, however several reports of 90-100mph were common in the Peak to Peak region.

Other features: The West Coast upper level ridge continues to be a persistent feature that has continued into the winter months.

This makes for dry and warm conditions in the western US and cold arctic conditions in the eastern US. The Front Range is right on the boundary between these airmasses and for the most part, the foothills have escaped the real cold by pretty much staying above it.

Outlook for February: We are already a week into February and have seen bit of light snow. It looks like we may see a stormy period between the 10-13th. After that the western ridge is showing signs of weakening and there may be Pacific systems in the offing. The temperatures will remain warmer than normal and precipitation will be at or slightly below normal. The long-term outlook for spring is for drought conditions in Colorado.

(Originally published in the February 15, 2018, print edition of The Mountain-Ear.)