Christmas week forecast update

12:30 PM MST, Tuesday, December 24, 2019

Lots of Pacific moisture over the last few days have produced high clouds, but little or no precipitation in the central Rockies. A more impressive area of Pacific moisture late Christmas Day and overnight will increase the likelihood of snow in the mountains and west, but the chances are still small for the eastern foothills and plains. A colder air mass late Friday and Saturday will bring the next chance for snow.

 

Mountains and West Slope

Expect 4-10″ at the high mountain passes and west-facing slopes, mainly Christmas afternoon and night. Another round of snow might arrive Friday afternoon, mainly for the southern Colorado mountains.

 

Front Range foothills and plains

There is a small chance for showery precipitation (snow or rain & snow) late Christmas Day or night, but the chance for accumulation is only about 10% in any one location. Temperatures should be cooler, but still average to above-average through Thursday.

 

On Friday there is a good chance for some snow in southeastern Colorado, mainly south of Colorado Springs. A cold front on Friday evening or Saturday morning will bring a chance for more widespread light snow. It is looking like the temperatures by Saturday and Sunday are likely to be a little below average for the first time in a while.

 

 

Mild solstice weekend, colder by Christmas

11:30 AM MST, Friday, December 20, 2019

The winter solstice is at 9:19 PM MST on Saturday, December 21st, but the weather this weekend will hardly be wintry. Dry weather with above average temperatures should be around through at least Monday. The Front Range urban corridor should get into the 50s, and maybe 60 during the days. There may be some high level cirrus clouds from time to time.

 

For Tuesday-Thursday there is a lot of Pacific storm action to the west of Colorado. But winds at most levels should have a westerly component, so precipitation in the eastern foothills and plains appears unlikely, and the chances for a white Christmas are low. There may be some high cloud cover at times and cooler temperatures. But very cold weather is not expected.

 

If you are traveling west Tuesday-Thursday, the chance for snow returns mainly at the high passes and west-facing slopes. There isn’t a big storm coming in, but be prepared for some winter travel in the high country, especially the San Juan region of southwestern Colorado.

Heavy mountain snow; some clouds and light snow lower elevations this weekend

12:15 PM MST, Thursday, December 12, 2019

A fetch of Pacific moisture and some embedded storms will bring a period of snowy weather in the mountains through Sunday, especially Friday night and Saturday. Well over a foot is likely near the divide. Watch out for winter travel at the high passes. 3-6 inches is possible as far east as Nederland.

 

For the lower foothills and eastern plains, colder weather is likely Saturday and Sunday with some periods of clouds and some light accumulations of snow.  The chance for intermittent snow exists throughout the weekend but there should be long dry periods too. Right now it looks like there are two periods to watch for snow. 1) On Saturday we may see the development of some narrow east-west bands extending from the mountains onto the plains. Accumulations will probably range from little or nothing to about and inch or two where those bands occur. It looks like there may be a better chance for accumulation north of Denver. 2) After a possible lull late Saturday and/or early Sunday there may be a general areas of clouds and light snow in eastern Colorado on Sunday as the main storm center moves east to the south of Colorado. A few inches could come with that round, with the best chances south of I-70.

 

It’s looking dry next week, maybe quite mild by late in the week.

Some rain and snow today

6 AM, Thursday, December 5, 2019

A minor storm passing through the Front Range region today will keep it generally cloudy with intermittent precipitation. Precipitation is likely to be mainly snow above 6000 feet, with minor accumulations of 0.5-3 inches. Below 6000 feet we are likely to see rain or rain mixed with snow, changing to snow later in the day. Accumulations in the lower elevations should vary from nothing to about an inch.

Temperatures are likely to hover in the 30s most of the day. Therefore, the rain won’t do much to melt the existing snow and ice, but it may further saturate the snow on the ground which will freeze tonight. The good news is that daytime temperatures should climb well above freezing Friday and Saturday. The next cold front and chance for minor snowfall is late Sunday or Monday.

Next storm: snow mountains, windy plains

8:30 AM MST, Thursday, November 28, 2019

Happy Thanksgiving!  Dry weather should continue along the Front Range into midday Friday. On Friday and Friday night much of the Colorado mountains will receive snow, with heavy amounts in the San Juan mountains. As a strong low pressure system heads up to the northern plains, there may be some squally showers in the eastern foothills and plains (snow or rain changing to snow) late Friday afternoon and night. Most of the Front Range urban corridor should get by with little or no accumulation, but some of the heavier squalls may produce an inch or two.

 

The main impact late Friday into Saturday for the Front Range will likely be strong wind gusts out of northwest (greater than 60 mph in some areas along the foothills). Hazardous blowing snow conditions are likely in some of the exposed areas of the foothills. In the lower elevations blowing snow can create local hazards, especially when the wind first arrives late Friday.

Update to snowstorm update

3:00 PM MST, Monday, November 25, 2019

Snow is developing quickly along the Front Range north of Denver and will continue spreading south through the evening. Be aware of rapidly changing conditions.

 

A number of forecast models become available in the early afternoon using the latest observations. Although the are no real changes to the big picture forecast, there is an update to the high end possibility. The chance for 20+ inches had increased to about a 1-in-4 chance in and near the foothills, mainly north of I-70.

Snowstorm update

11:40 AM MST, Monday, November 25, 2019

There are a few minor updates to the previous blog:

  • The storm is intensifying a little faster while still in western Colorado. This may help focus the highest accumulations in and near the foothills north of I-70, but significant accumulations are expected on the northeastern plains too.
  • East and southeast winds tonight (just above the surface) may favor Fort Collins and Cheyenne with the biggest snowfall rates. Northeast winds late tonight and tomorrow morning may shift the main focus to Boulder and the west side of Denver. Snow should taper off from northwest to southeast Tuesday afternoon and evening.
  • Blowing snow is likely to be an additional hazard, especially along and east of I-25.
  • Major impacts are likely through Tuesday at DIA.
  • I would not be surprised to see parts of I-25, I-76, and I-80 closed for a period of time in northeastern Colorado, southeastern Wyoming, and Nebraska.

 

Most likely accumulations

12-18 inches: Cheyenne, Fort Collins, Estes Park

9-15 inches: Boulder, Broomfield, Arvada, Golden

6-12 inches: DIA, Longmont, Denver, Aurora, Castle Rock

2-4 inches: Colorado Springs

Begins this afternoon in Cheyenne, late afternoon or early evening in Fort Collins, Boulder, and Denver.

Peak snowfall this evening through Tuesday morning, tapers off Tuesday afternoon and evening.

Wednesday-Sunday

  • Dry for the Front Range urban corridor Wednesday and Thursday
  • Some areas of snow, mainly light, in the mountains and the southern foothills on Thursday
    • Some moderate or heavy snow is possible in the San Juans of southwestern Colorado Thursday
  • Some areas of light snow or flurries possible along the Front Range Friday or Friday night
    • some local moderate or heavy snow possible near the higher passes of western Colorado Friday, especially the San Juans
    • valley rain or snow showers in western Colorado Friday
  • Probably dry Saturday-Sunday, but will update later in the week