By Bill Kappel
The El Niño pattern was in full effect in December, with temperatures and precipitation above normal around the Palmer Divide. During El Niño patterns, the storm track over the southern U.S. becomes stronger and more active. This often brings a series of storms through California and the southwestern U.S. and along the southern Plains and Gulf Coast. At the same time this allows warm air to move into the central Plains and Ohio Valley, which bottles up the cold air in Canada. Therefore, cold air outbreaks are less common. And this December we didn’t see any Arctic fronts move through. This was the opposite of 2022, when some very cold air moved in the week before Christmas.
The month started out with some light snow each of the first three days, although temperatures were only slightly below average. During the period, 2-4 inches of snow fell, with highs reaching the 30s each afternoon. Mild conditions moved in soon after, with highs reaching near daily record levels in the mid- to upper 60s on the 6th. As is normal, this was ahead of a storm system that was approaching the region from the west. This storm brought a quick change in the weather starting the morning of the 8th, with areas of snow showers increasing to snow and blowing snow during the day and continuing into the early morning of the 9th. This storm brought another 4-8 inches of snow to the region over the two-day period. Temperatures were cooler as well, with highs reaching the mid-20s on the 9th and overnight lows in the single digits above and below zero.
Another change moved in for a few days, but this time temperatures didn’t warm up as much, only reaching normal levels in the 30s and 40s before another quick-moving storm brought 1-4 inches of snow to the area and cooler temperatures on the 13th. Of course, the nice part about each of these snowfalls during the first two weeks of the month helped get us in the Christmas spirit with plenty of fresh snow on the ground. However, a longer streak of mild and dry conditions then moved back in from the 15th through the 22nd. Temperatures peaked on the 19th, with highs reaching the upper 50s to low 60s.
However, this pattern began to break down just in time for Christmas with a large area of low pressure developing over eastern Colorado and slowing moving into Kansas and Nebraska. Initially this storm brought a couple inches of snow into Christmas. Then a brief break occurred on Christmas Day before the storm continued to intensify to our east. At the same time, the storm took an unusual pattern and retrograded back to the west. This produced a prolonged period of strong northerly flow and moisture in the region from Christmas night through the morning of the 27th. This snow came in waves with a good period of heavy snow and wind the morning of the 26th and a second period of heavier snow and wind during the afternoon and evening of the 26th.
There were a couple of unique aspects with this storm. First, its northerly flow meant that the topography of the Palmer Divide was very important in developing snowfall and keeping temperatures cold enough for snow. This meant areas to our north around Denver and to our south in Colorado Springs received very little snowfall and in some cases rain showers. The other aspect was the location of the low-pressure system to our east. This left us right on the far western edge of the storm, and therefore areas farther east received more snowfall and areas farther west much less. The dividing line was right around I-25, with areas to the east picking up 6-10 inches and areas to the west only a couple inches at most. During this period, temperatures were cool as well, with highs below freezing and lows touching zero on Christmas morning.
After this storm departed, conditions were quiet and sunny heading into New Year’s weekend. Temperatures responded, climbing from the 30s on the 28th to the 40s on the 29th and the 50s on the 30th.
A look ahead
January can see the coldest temperatures of the year, but there is often a proverbial “January thaw” where mild temperatures make brief appearances. Of course, that’s been the case all winter so far, so hopefully this January will see a shift in the overall pattern to cold and snowy conditions. Unfortunately, precipitation is usually on the low side, with amounts generally less than an inch. The month experiences numerous sunny and windy days, with quick shots of snow in between.
December 2023 Weather Statistics
Average High 43.2° (-0.5°). 43.7 100-year return frequency value max 50.5° min 32.6°
Average Low 19.4° (+6.1°) 13.3 100-year return frequency value max 22.4° min 5.4°
Monthly Precipitation 1.51” (+0.50”, 44% above normal) 100-year return frequency value max 2.82” min 0.00”
Monthly Snowfall 27.2” (+9.5”, 45% above normal)
Highest Temperature 66° on the 5th
Lowest Temperature 0° on the 25th
Season to Date Snow 41.7” (+2.2”) (the snow season is from Oct 1 to Sept 30)
Season to Date Precip. 26.38” (+4.09”) (the precipitation season, Jan 1 to Dec 31)
Heating Degree Days 1046 (-239) 1285
Cooling Degree Days 0 (0)
Bill Kappel is a meteorologist and Tri-Lakes resident. He can be reached at billkappel@ocn.me.
Other Weather articles
- November Weather Wrap (12/5/2024)
- October Weather Wrap (11/2/2024)
- September Weather Wrap (10/5/2024)
- 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)