John McGinley, Peak to Peak. October 2019: After a warm summer-like September, October wasted no time in establishing a winter like weather pattern with high-amplitude troughs setting up over the western half of the nation. Colorado was impacted by a series of polar air-masses that brought record low temperatures and heavier than normal snow. It seemed like more of a winter month as even the winds blasted the Peak to Peak region frequently. It was certainly one for the record books as we reached the lowest temperature ever seen in the month of October (at least in the 54 year record), had the lowest mean temperature of any October, had snow 2.5 times normal, had 50% more windy days. Are you ready for November?

Precipitation: Total was 1.9 inches with 28.2 inches of snow. Not near the record of 49.7 inches received in Oct 2006, but still respectable compared to the average of 11 inches. Biggest snow day was 9 inches on the 24th. The big story however, was the multi-day events from Oct 20-24 and Oct 27-30 each dropping over 10 inches.

Temperature: Quite a contrast here compared to previous months. We were 6.5 degrees below the normal mean temperature of 41.7 setting a record for the coldest October. The low of -7F on the 30th was the coldest observed in any October. The previous record was -2F. Warmest high temperature was 68F on the 4th; coldest high was 12F on the 30th. 

Winds:  Nine windy days (40+ mph) were recorded with two days with winds over 70mph (Oct 20th, 22nd). In more exposed locations winds topped 100mph causing some damage.

Other Features: The counterpoint to our cold events are the warm and extremely dry conditions on the west coast produced by down sloping winds forced by cold high pressure systems over the Great Basin. Sadly, we are seeing another devastating fall fire season in California.

Outlook: November is the first of the big four winter-like months. Conditions get decidedly cooler with more snow likely. The climate norms show an average high of 41F and an average low of 21F. We will see 1.13 inches of liquid and 18 inches of snow. Winds crank up with 11 windy days and two extremely windy days. Our long range models are hinting at an eastward shift of the west coast ridge during the first half of the month. We’ll still have some polar airmasses, but the severity will be much reduced with slightly warmer temperatures and minimal snow. By week three look for frequent bouts of westerly flow, strong winds, and over-the-Divide snow flurries. Overall it looks like a dry month.

(Originally published in the November 7, 2019, print edition of The Mountain-Ear.)