5:45 AM MST, Friday, November 16, 2018
Expect a cold weekend with some snow around on Saturday, and sun returning on Sunday. A strong cold front should move north to south through the Front Range region this evening followed by low clouds. It may take until morning for the clouds and colder weather to get into the higher elevations. Temperatures on Saturday are likely to stay in the 20s all day throughout the Front Range urban corridor and then return to the 40s Sunday afternoon.
Initially the middle and upper parts of the atmosphere might be somewhat dry. That limits the cloud depth and the generation of larger snow crystals. So we may see some areas of light snow, snow grains, or freezing drizzle late tonight and early Saturday. On Saturday we are likely to transition to all snow where there is precipitation.
Accumulations are expected to be on the light side, with the highest amounts in the northern Front Range region, and little or nothing down in Colorado Springs.
3-5 inches: Cheyenne
2-4 inches: Fort Collins
1-3 inches Denver-Boulder metro
0-2 inches south of Denver
7 AM MST, Monday, November 12, 2018
The weekend storm was not only stronger than expected, but it took a path farther west of Colorado putting the Front Range region in stronger and much more persistent easterly upslope flow than had been expected. Many areas got on the order of 6 inches. In and along the lower foothills of Boulder County seemed to be the sweet spot where up to 15 inches fell. The Boulder Climate Station had 13.4″ of snow which contained 0.68″ of liquid.
For those who love snow, you had a pleasant surprise. For those who don’t, dry weather will rule this week after some Monday morning flurries. A return of afternoon temperatures in the 50s will be in place by Wednesday, so the snow will soon be history.
The next cold front and chance for snow is lurking for this weekend.
12:40 PM MST, Saturday, November 10, 2018
The initial cold front is through Cheyenne at noon. That front will likely move through the Denver metro area by mid afternoon and start turning it cooler. A colder push of air is likely this evening with clouds and the first snowflakes possible before midnight. Sunday is expected to remain below freezing all day.
Most accumulation is likely to occur between midnight tonight and noon Sunday. But intermittent snow with some minor additional accumulation will probably occur in some areas into late Sunday night.
Most likely accumulations:
3-7 inches: mountains, foothills and Palmer Divide
2-4 inches: Boulder, Broomfield, Denver, Castle Rock, Colorado Springs
dusting – 2 inches: DIA, Longmont, Fort Collins, Cheyenne
After a cold start to the week, it appears mild weather is on the way for Tuesday-Thursday.
3 PM MST, Friday, November 9, 2018
After a mild a windy Saturday, a strong cold front will move north to south through the Front Range region late Saturday afternoon and evening. Expect a cloudy and cold day Sunday with temperatures staying below freezing all day. Light accumulations of snow are likely, especially late Saturday night and Sunday morning.
3-5″ – Nederland, Eisenhower Tunnel, Estes Park, Palmer Divide region
1-3 inches – Denver-Boulder Metro, highest on west side.
Dusting – 2 inches – Cheyenne, Fort Collins, Weld County, Colorado Springs
3:30 PM MDT, Friday, November 2, 2018
A couple rounds of snow are likely this weekend in the high elevations near and west of the continental divide, with dry and seasonably mild weather for the Front Range foothills and plains. Saturday will likely be a little cooler than Sunday, but neither day will be cold compared to the seasonal average.
Snow is expected to cause some winter driving conditions at and near the high passes tonight. Then after a relative lull late Saturday into early Sunday there will probably be more high elevation snow develop on Sunday afternoon into Monday. The accumulations will be mainly near and west of the high peaks, but some accumulation will probably occur within a few miles to the east side of the continental divide. I expect very little in Nederland and Estes Park.
Next chance for the plains
After tonight the next fast moving Pacific storm system may bring some sprinkles or flurries to the lower elevations Monday. But the next real chance for snow in the lower foothills and plains appears to be Wednesday or Wednesday night. That will be updated as we get closer.
6:00 AM MDT, Tuesday, October 30, 2018
Intermittent precipitation during the day should be mainly snow above 7000 feet and mainly rain below 6000 feet, with rain changing to snow between 6000 and 7000 feet. During the late afternoon and evening northeasterly flow through a deep layer of the lower atmosphere will probably result in a period of steady precipitation changing over to snow at all elevations. Snow should end from Denver north late tonight, but may linger into morning for the Palmer Divide region and south.
Big variation can be expected from mountains to plains with this storm. Even on the plains you may not have to go very for to the east in northeastern Colorado to get little or no snow.
Above 7000 feet: 5-10 inches (locally 12″ in some areas south of I-70)
6000-7000 feet: 3-6 inches
Boulder, Broomfield, Denver (south & west suburbs), Colorado Springs: 2-4 inches
Fort Collins, Longmont, east Denver & DIA: 0-2 inches
Does it really almost always snow on Halloween?
Snow on Halloween is a reputation around here. The Boulder climate record shows that the phrase “almost always” is a bit of an exaggeration, but it’s easy to see where the snowy reputation comes from. In the last 30 years there has been measurable snow (at least 0.1 inch) five times on Halloween. But if we look at the week centered on Halloween (Oct 28-Nov 3) there has been measurable snow 16 out of the last 30 years, or 53% of the time. By comparison the 1-week periods that include Thanksgiving, Christmas, Presidents Day, and St Patrick’s Day all have about a 60% chance for measurable snow. So Halloween week does signal the ramp-up to winter season snow probability.
4:00 PM MDT, Monday, October 29, 2018
I’ll give a real update early tomorrow morning. This is a quick note to say that my snow forecast this morning might be a little too timid. If the current trend continues people in and along the Colorado foothills should be ready for some sloppy conditions tomorrow in the higher terrain, and late Tuesday into the overnight in the lower elevations near the foothills.