9:00 AM, Friday, February 23, 2018
Colder than average weather, but not extreme cold, should be with us through the weekend. Snow is likely by this evening in the Front Range urban corridor, possibly early enough to have some impact on the evening commute.
A broad upper level trough in the West has kept it cold and is sending occasional disturbances through the Front Range region. Snow last night was quite minor in most places except a portion of northern Jefferson County where about 4 inches fell in a short period around Arvada and Wheat Ridge.
Another disturbance is likely to result in widespread minor accumulations (mainly from Denver northward) late this afternoon and evening. But once again some narrow bands of heavier snow oriented southwest-northeast can result in 1-4 inches very quickly for a subset of the area. Watch for rapidly changes conditions.
The weekend should be mainly dry (except some snow in mountain areas). Temperatures will remain below average, although they may rise above freezing along the Front Range. No dramatic warm-ups are likely over the next 5 days
Noon, Tuesday, February 20, 2018
Cold weather will continue all week, but less extreme after Wednesday. Some intervals with clouds and flurries are possible late today and again Thursday afternoon into Friday.
Boulder got down to -6 this morning eclipsing the old record of -1 set in 1918. DIA got down to at least -3 from what I can tell which was not a new record. DIA is often one of the coldest locations in the Denver area, but low clouds hung on a little longer out there preventing ideal radiational cooling.
Tonight the record is -2 in Denver (1955) and +4 in Boulder (1911). In both cases they are the warmest record lows in February (and in Boulder’s case the only one above zero). There is a chance of getting down to the record tonight, especially in Boulder.
Today’s record low maximum temperatures are 16 in Denver (1911) and 17 in Boulder (1918). It’s possible we will stay colder than that in at least one location.
Cold and unsettle this week
The record cold will pass, but below average temperatures will continue for the rest of the week.
A storm system to our west is close enough to result in some periods of clouds and light snow at times through the week. Late today is one period where some light snow or flurries are possible, with very minor accumulations of a half-inch or less, mainly south of Larimer County.
Another period when the chance of light snow or flurries increases is late Thursday through Friday. That too looks minor.
The good news is that the mountains of Utah and southern Colorado, where the snowpack is well below average, are finally getting some. It’s not enough to erase the snow deficit, but it helps. In northern Colorado the mountain snowpack is not as bad, and they are getting some snow too this week.
11:30 AM, Monday, February 19, 2018
Expect snowy conditions to continue (and maybe get worse) through this evening from metro Denver northward with very cold weather through Tuesday.
The periods of intermittent light snow should continue through the night. More important is the likelihood for narrow southwest-northeast bands of heavy snow late this afternoon and evening. These bands parallel the jet stream and may only be 10-15 miles wide but a hundred miles long, so conditions can vary greatly over short distances. Most of the best local scale models are predicting a main band stretched from the north and west sides of metro Denver to Weld County. I don’t completely trust the forecast of a specific location, but a period of heavier snow in a small area somewhere from metro Denver northward seems likely.
Total accumulations through Tuesday morning from metro Denver north are likely to be 2-4 inches in most areas, with 4-6 associated with the heavier bands late this afternoon and evening. Colorado Springs will likely be south of the main action.
Many parts of the Front Range urban corridor may not see temperatures rise above 20 until Wednesday. Nights will probably be in the single digits, and if there is partial clearing Tuesday night some of the normally cold spots might slip below 0. Even though it won’t be as cold later this week, we will probably remain a below average with some potential for more cloudy intervals and light snow.
Noon, Sunday, February 18, 2018
The 3-day weekend will end much colder than the first two days, with some snow, mainly north of Colorado Springs. The cold surge is already through Casper, WY and is likely to slide down the Front Range tonight. There may be some light snow or freezing drizzle by Monday morning, and a better chance for snow along with even colder air Monday afternoon and night.
Widespread accumulations of 1-4 inches can be expected from the Denver area northward, but there will probably be some narrow southwest-northeast bands of heavier snow resulting in some areas getting 3-6 inches, mainly Monday afternoon or night. With temperature in the 20s and maybe even colder by late day Monday, expect wintry road conditions.
As you go south from Denver the chance for snow decreases, with just a small chance for accumulations in Colorado Springs and Pueblo. Snowy conditions are likely at many of the high passes as well. North and west of Cheyenne heavy snow and wind may force some road closures.
Very cold weather will continue through Tuesday.
11:45 AM, Thursday, February 15, 2018
It’s already a bit cooler, and a more distinct cold front is north of Cheyenne around noon on Thursday and should move south through the Front Range region from mid afternoon through early evening. Other than the continued snowfall in the high elevations near the continental divide, the cold front is not expected to bring precipitation of consequence to the lower foothills and plains. Most parts of the Front Range urban corridor will stay dry, but there could be some minor snowfall this evening (most models suggest the best chance for that is south of I-70). Be careful if you are heading west over the high passes.
Friday should be a dry and cool day.
Enjoy generally dry and mild weather Saturday and Sunday, but watch for some areas of gusty Chinook winds near the foothills.
The different models have been calling for a switch back to winter by Monday. Some model runs have even suggested a significant snowfall along the Front Range, with others show a rather minor snowfall. For now you should expect Monday to be the cold day of the weekend with at least some snow. I’ll have to re-assess the snow chances as we get closer to Monday.
6:00 AM, Monday, February 12, 2018
A storm that is moving south through the western United States as it weakens will have minor impacts in the Front Range region today. Expect a cloudy day with temperatures remaining below freezing. There may be some flurries or a period of light snow, but accumulations should range from zero in some places to an inch in others.
Tuesday and Wednesday should bring dry and milder weather. The next chance of snow arrives on Thursday.
5:00 PM, Friday, February 9, 2018
Even colder air will push south through eastern Colorado by Saturday keeping temperatures far below freezing (maybe no better than low 20s). Accumulating snow is likely Saturday throughout the Front Range region. It should be mainly light intensity, but some local bands of higher intensity could occur too. Most parts of the foothills and plains will likely see 1-3 inches. There could be a few local spots with a little more than 3. Near the continental divide up to 6 inches can be expected.
Although these aren’t very big amounts, given the cold, icy roads are likely. It appears late morning through evening might be the most likely time for accumulations.
Heads up: right now (5 PM Friday) there are some narrow east-west bands of snow developing in northern Colorado. I don’t expect much tonight, but be prepared for some localized areas of light accumulation.