9:30 AM, Sunday, December 30, 2018

After a mild Sunday, Monday will bring very cold weather and some snow. The best chance for accumulation along the Front Range urban corridor will be south of a line from Lyons to Longmont to DIA. Although a big storm is not expected, you should be prepared for some winter driving conditions in the mountains and in the Denver-Boulder area on Monday.

Accumulation

0-1 inch: Fort Collins, Greeley, Longmont

1-3 inches: Cheyenne, northeast Denver & DIA, Colorado Springs

2-4 inches: Boulder, Broomfield, west and south sides of Denver, Castle Rock

3-6 inches foothills and Palmer Divide of Douglas, Jefferson, and Boulder counties

Mild, then very cold, then mild

Mild weather today will be replaced by temperatures on Monday that fail to make it to 20 degrees. It will probably be around zero in Denver-Boulder around the time that the new year arrives. By New Year’s morning temperatures are likely to range from 0 to -10 along the Front Range (coldest in areas that have snow cover).  But then by the Thursday-Saturday period dry, unseasonably mild, and occasionally windy weather will be in place.

11:30 AM MST, Friday, December 28, 2018

The cold will let up a bit by Sunday ahead of another cold front Sunday night that should bring more cold weather New Year’s Eve and New Year’s Day. No major storms are expected to impact the Front Range Region during the weekend, but some light snow amounts may accompany the arrival of the next cold spell Sunday night or Monday.

Temperature

December did not bring any temperature extremes (either warm or cold). Although tonight will probably be the coldest of the season so far for the Front Range and eastern plains, it won’t be anything remarkable for this time of year.

By Sunday we should see temperatures near or even a little above average (40s for most of the Front Range urban corridor). The the next cold air mass Sunday night should keep daytime temperatures no warmer than the 20s for New Year’s Eve and New Year’s Day, and New Year’s morning will probably see a range of 0-10 for most locations in the urban corridor.

Snow

A relatively weak storm system with the next cold front will probably bring some light snow amounts Sunday night or Monday for the mountains and the urban corridor. Right now it’s looking pretty minor. I will update on Sunday.

Warm spell ahead

Beginning on January 2nd it appears we may enter a multi-day stretch of dry and unseasonably mild weather. But as is often the case with warm weather in January, we will have to watch for the potential for some windy periods.

7 AM MST, Wednesday, December 26, 2018

Cold weather will be in place through Saturday, with temperatures even in the lower elevations likely to stay below freezing all day Thursday and Friday.

A storm system moving to the south of Colorado and then intensifying out on the Great Plains will mostly miss the Front Range and the urban corridor. The best chance for accumulating snow tonight and early Thursday will be in the south suburbs of Denver and the Palmer Divide region, but even here the amounts will likely be less than 2 inches where it does snow. From Denver northward, 0 to 1 inch will likely be the range, with 0 most likely in Longmont, Fort Collins, and Greeley.

Light snow amounts are likely today and tonight in the higher mountains.

The only area with significant winter weather is out on the high plains near the border with Kansas and Nebraska. Around 6-10 inches of snow and blowing snow may make travel difficult late tonight and early Thursday for people traveling west toward the Front Range on I-70, I-76, and I-80.

There is a small chance for flurries or areas of light snow Friday, but that is more likely along the southern Front Range (south of Pueblo).

8:45 AM MST, Sunday, December 23, 2018

The main considerations for the weather over the next week are:

1. Dry weather is expected for the eastern foothills and plains through Christmas afternoon (snow on Christmas Eve over the mountains and high passes).
2. A period of colder & unsettled weather is likely Wednesday to Saturday (and maybe through New Years Day).
3. A major snowstorm for the Front Range region the day after Christmas is unlikely, but there will probably be a couple minor snowfalls beginning the 26th.

Now through Christmas

A weak Pacific storm moving through the central Rockies on Christmas Eve will have little impact on the weather of the eastern foothills and plains. In fact Christmas Eve may be the milder of the next 7 days for the Front Range region. For the West Slope, areas of light snow are likely on Christmas Eve, with some moderate amounts of 6-10 inches at the high passes. Drier weather is expected on Christmas in the mountains.

After Christmas

A large but not particularly strong storm system is expected to move south of Colorado on the 26th. It is forecast to have a north-south orientation which results mainly southerly winds at first and then switching mainly to northerly. The result is very little easterly “upslope” flow that is more conducive to snow.  So right now the expectation is for minor snowfall and colder temperatures for the Front Range region on Wednesday or Wednesday night.

Farther east on the high plains (around the Nebraska and northwest Kansas border) a period of heavier snow and wind is more likely late Wednesday or Wednesday night which could make travel difficult. There may even be some rain or sleet at the start.

Another cold front and round of widespread clouds and snow appears to be on the way for the late Thursday through early Saturday period.

6 AM MST, Friday, December 21, 2018

The winter solstice occurs today at 3:23 PM MST, but it won’t feel a lot like winter. Today should feature above-average temperatures with some gusty chinook wind at times.

Christmas weekend

Some minor snowfall is expected for the mountains tonight into early Saturday. For the eastern foothills and plains some clouds and localized light snow might occur Saturday morning. Most areas will probably stay dry, and where it does snow it would be minor. Cooler temperatures, more typical of this time of year, are expected Saturday and Sunday.

Other than that small chance for light snow or flurries Saturday morning, dry weather is likely through Christmas morning for the eastern foothills and plains, along with slightly milder temperatures by Christmas Eve. There may be some minor snowfall again in the mountains and high passes on Christmas Eve. The next storm system that may bring widespread snow across the region is due late on Christmas Day or overnight.

Wintry weather pattern by Wednesday

A switch to colder than average weather is likely to begin late Tuesday (Christmas Day) or early Wednesday and last until the next weekend. It look like clouds and snow may usher in that cold period by Wednesday morning (possibly as early as Tuesday afternoon). The magnitude and timing of the snow will need to be updated as we get closer. For now, be prepared for some wintry travel after Christmas, but generally good travel weather in the local region before Christmas.

6 AM MST, Wednesday, December 12, 2018

The weather

A cold front later today will bring in a day of cooler weather before mild weather returns on Friday. Some light snow amounts are likely in the mountains this evening, but for the eastern foothills and plains little or no snow is expected. Other than the brief cool down to near average temperatures tonight and Thursday, the next week is likely to see mainly dry weather with above average temperatures throughout the region. Gusty winds are likely to develop today ahead of and following the front.

Geminid meteor shower

The Geminids, on the night of December 13-14th, are one of the two best meteor showers of the year (the other being the Perseids in mid August). This year the half-moon will set before midnight, so the best time to watch is between midnight and daybreak. The chance for clear skies is good, but we always have to watch for the development of high level ice crystal clouds along and just downwind of the high mountains.