By Bill Kappel
October was again warmer than average with below-normal precipitation. Almost the entire month saw quiet and dry weather, with exceptions at the beginning and end. Overall for the year, we are still above normal from a precipitation perspective, so hopefully that will continue through the winter and spring. And given that we have an El Niño pattern set up in the Pacific, there is a higher-than-normal chance of above-normal snowfall, especially later into winter and through the spring. Let’s hope this pattern plays out.
The other nice aspect of the quiet weather most of the month was that the sunny skies, warm days, and cool nights were perfect for the development of fall colors. This resulted in a nice progression of fall colors as we moved through the month and no storms or strong winds coming through to freeze the leaves or blow them away too quickly.
The month started off mild with highs in the mid-70s on the 1st and 2nd. This warmth also helped to produce some last remnants of summer-type weather, with thunderstorms developing during the late afternoon and early evening of the 2nd. These produced some quick rainfall accumulations of nearly a half inch in spots. However, for most of us, this was our last measurable precipitation for several weeks until the 28th. The only exception were some showers of both rain and snow at times from the afternoon of the 11th off and on through the morning of the 13th. This was an extended dry period even for a time of the year when quiet weather conditions are common.
The quiet pattern was finally broken starting on the 26th and continuing through the 29th. The first change was signified by a cold front that blew through during the late afternoon of the 26th bringing cooler air, low clouds, fog, and a few flurries. After this initial push, cool and quiet weather took hold on the 27th before a stronger push of cold air and moisture moved in on the 28th. This second, stronger cold front was overrun by moisture and lifted aloft. This allowed the atmosphere to moisten up and, when combined with the upslope flow, produced widespread snow from the 28th through the afternoon of the 29th.
Temperatures were well below normal as well with highs dropping from the low 70s on the 26th to the low 40s on the 27th and low 30s on the 28th. Bands of snow began to develop during the afternoon of the 28th and continued off and on through the 29th. This system was different than our typical snow events because it was driven by strong winds and rising motion high in the atmosphere combined with cold air at the surface. This resulted in a wide range of snowfall totals over relatively short distances. Temperatures were coldest on the 29th through the morning of the 30th, as highs struggled to reach 20 degrees and morning lows dipped all the way to the single digits above and below on the 30th. Sunshine returned to end the month, but the clear skies and lingering snow meant a cold start to each day, and also kept afternoon temperatures below average through Halloween.
A look ahead
November is generally dry and cool around the region. We usually get several light snowfalls interspersed with sunny skies. Gusty winds commonly develop on a couple of days as the jet stream becomes more active and directly affects Colorado. High temperatures average in the upper 40s early in the month to low 40s by the end with overnight lows often dipping into the teens and single digits.
October 2023 Weather Statistics
Average High 62.0° (+2.5°) 100-year return frequency value max 67.7° min 50.7°
Average Low 31.2° (+1.9°) 100-year return frequency value max 36.8° min 26.4°
Monthly Precipitation 0.41” (-1.12”) 100-year return frequency value max 4.63” min 0.18”
Monthly Snowfall 3.6” (-7.4”)
Highest Temperature 78° on the 20th
Lowest Temperature -1° on the 30th
Season to Date Snow 3.6” (-7.4”) (the snow season, Oct 1 to Sept 30)
Season to Date Precip. 24.26” (+2.74”) (the precipitation season, Jan 1 to Dec 31)
Heating Degree Days 570
Cooling Degree Days 0
Bill Kappel can be reached at billkappel@ocn.me.
Other Weather articles
- September Weather Wrap (10/3/2024)
- August Weather Wrap (9/7/2024)
- July Weather Wrap (8/3/2024)
- June Weather Wrap (7/6/2024)
- May Weather Wrap (6/1/2024)
- April Weather Wrap (5/4/2024)
- March Weather Wrap (4/6/2024)
- February Weather Wrap (3/2/2024)
- January Weather Wrap (2/3/2024)
- December Weather Wrap (1/6/2024)