12:00 Noon, Thursday, December 31, 2015
It’s not every year that we get a week-long stretch that stays completely below freezing in the Front Range urban corridor. Today is Day 7 for Denver, Boulder, and Fort Collins (didn’t quite stay that cold in Colorado Springs). Although the cold spell did not bring any record cold, the persistence of the cold has been noticeable.
There is a chance that the temperature may nudge above freezing on New Years Day, it’s likely to get above freezing on Saturday, and near average for this time of year (40-45) by Sunday afternoon. Even Estes Park and Nederland might get up to the freezing mark this weekend. Dry weather is likely other than a few flurries in the mountains today.
The year will end wetter than average for many Front Range locations thanks mainly to a wet period from mid Spring to mid Summer.
Happy New Year!
12:20 PM, Thursday, December 24, 2015
The northern part of a Pacific storm system will increase clouds and the chances for snow on Christmas Day, especially in the mountains. The best chance for intermittent snow is Christmas afternoon through Saturday morning.
1-4 inches in the lower elevations. (Most areas will probably see 1-2, with locally up to 4 in and near the foothills.) Mountain accumulations should range 3-7 inches.
Temperatures on Saturday will struggle to make it to 20 even in the urban corridor, and Sunday morning will likely range 0-10.
The southern part of the storm system is stronger and is likely to bring significant snow to New Mexico late Saturday and Sunday, but the Front Range region should be mainly dry and cold.
12:30 PM, Wednesday, December 23, 2015
The lower elevations of the Front Range will be drier than the mountains, but there may be some accumulating snow on Christmas Day into the 26th. Slightly below average temperatures through Christmas will be replaced by even colder weather over the weekend.
Mountains: Expect snowy travel at times, especially at the passes. Christmas Eve day may see the best lull, especially during the morning and midday. Snow on Christmas Day is likely to shift south Saturday and Sunday with the New Mexico mountains getting the most over the weekend.
Front Range foothills, urban corridor, and plains:
Generally dry through Christmas Eve. As the storm to the west splits around Colorado, there is a small chance we may see some areas of snow by Christmas morning, and a better chance by late afternoon or overnight into the morning of Dec 26th. A major storm appears unlikely, but you may be dealing with snowy roads at times. Expect drier weather by late Saturday as the southern part of the storm intensifies and shifts its focus into New Mexico. Daytime temperatures over the weekend may struggle to reach the 20s even in the lower elevations.
Air travel: Minneapolis, Denver, and Salt Lake may be the only major hubs that deal with some snow today or through the weekend (maybe Chicago by the end of the weekend). Unusually warm, moist air over the central and eastern U.S. may impact air travel at times due to fog, rain, and even strong thunderstorms.
3:10 PM, Tuesday, December 22, 2015
This evening through Wednesday:
Mountain areas will continue to get snow, and although Wednesday should be less intense than today, expect winter travel conditions in places west of Denver and Cheyenne.
The cold front moved through the Front Range region Tuesday afternoon, and there is likely to be some areas of snow this evening. Many parts of the urban corridor will get little or no accumulation, but a few spots are likely to get a quick inch.
Christmas Eve-Christmas Day:
Christmas Eve Day is likely to be a lull in activity and may be a good day for travel throughout the central and southern Rockies and high plains. The next storm will begin impacting the area on Christmas Day with a good chance for more snow in the mountains, and some chance for areas of light snow along the Front Range.
The storm on Christmas Day is expected to split into two with the first part moving through eastern Wyoming into South Dakota. The second part of the storm is likely to be stronger and move through New Mexico late Saturday into Sunday. At this point it looks like the Colorado Springs-Denver-Boulder-Cheyenne region will be well north of the biggest impacts, but travel toward New Mexico might get rough by late Saturday.
Air travel: unusually warm weather will keep the snow and ice issues away from major air hubs in the central and eastern U.S., but some may be impacted by rain and fog. In fact Dallas and Chicago may have to deal with thunderstorms this coming weekend.
2:40 PM, Monday, December 21, 2015
The winter solstice is at 9:49 PM MST today, and it will behave like winter tonight and tomorrow along and west of the higher terrain. Generally unsettled weather is likely through Wednesday, with the bigger impacts along and west of the continental divide. A larger storm system may impact the region on Christmas weekend, but right now is looks like it will pass mainly south of Colorado.
Mountains and West:
Moist Pacific flow from the west will bring periods of snow and wind mainly along and west of the mountains this week, especially Tuesday. There may be a little lull around Christmas Eve before a storm system brings more snow on Christmas, but the main impacts this weekend may be in the mountains of southern Colorado and New Mexico.
Front Range and Plains:
Mostly dry, occasionally windy (especially Monday night near the foothills). Mild temperatures on Tuesday will be replaced with colder temperatures Tuesday evening (but not bitter cold). There aren’t any organized storms through Christmas Eve, but pieces of the western action move east and cause some brief snowy periods in some areas Tuesday evening or Wednesday. The storm system for Christmas Day through Sunday is one to watch, but it looks like the main impacts are likely to be south of Colorado Springs.
Bottom line: Be prepared for areas of wintry travel on parts of I-70 west of Denver and I-80 west of Laramie this week. By the weekend, I-25 south toward New Mexico may have wintry travel.
First the good news. Dry and milder weather is in store for Friday afternoon through Saturday. Even Sunday should be nice for the foothills and plains, just a little cooler than Saturday. Mountain areas area likely to see areas of snow Sunday, probably making it messy for the high passes.
Now the not so good news. Gusty west winds may cause some blowing snow later tonight and Friday morning. This will likely be limited to the foothills and some local spots near the foothills. Watch for rapidly changing conditions over short distances.
1 PM, Tuesday, December 15, 2015
Although forecasts today are easily shown to be more accurate than as recent as 10 years ago, today’s storm reminds us that weather features are complex moving targets. Under and over-forecasting makes forecasting a compelling challenge, and keeps me humbled.
We knew it would intensify into a potent storm overnight, but the forecast position was a challenge. The most prolonged heavy snow occurs when the center of circulation passes to the south. We expected this one to pass through the Denver-Boulder area which would put the heaviest snow up in southern Wyoming. In reality, the primary circulation passed just south of Colorado Springs as it moved eastward. That put the Denver-Boulder-Fort Collins corridor in the sweet spot (or sour spot if you’re a snow scrooge). Cheyenne got it too, but it wasn’t so unexpected there.
There is mainly light snow left as of 1PM except for a few pockets of moderate snow mainly east of I-25. That should continue to taper off and end later this afternoon and evening.
12:15 PM, Monday, December 14, 2015
Expect accumulating snow late tonight and on Tuesday morning to impact ground and air travel. The highest impacts are likely in the Cheyenne area and on the northeastern plains of Colorado, with moderate impacts for the Denver-Boulder-Fort Collins corridor, and minor impacts in Colorado Springs.
Monday Evening: the chance for snow increases in mountains , especially in southern Wyoming and central Colorado.
Late tonight and Tuesday morning: main snowy period for the Front Range and adjacent plains. Increasing winds on the Colorado plains and in the Cheyenne area. 3-9 AM will be probably be the peak snowfall period.
Tuesday afternoon: snow tapers off from west to east. Maybe some significant snow and blowing snow out east on the high plains of northeastern Colorado.
Mountains: generally 6-12 inches, highest accumulations in north-central Colorado (around Vail Pass and Steamboat). Nederland is likely to be on the lower end of that range.
Cheyenne area: 5-8 inches, blowing snow.
Metro Denver-Boulder-Fort Collins: 2-5 inches. Blowing snow, especially east of I-25. A slight shift in track could result in little or nothing, or add a few more inches, but that appears to be a very small chance at this point.
Colorado Springs: 0-2 inches
Bottom line: A paralyzing storm is not expected, but winter travel conditions are expected by Tuesday morning. The worst conditions won’t necessarily be in and near the foothills.
3:20 PM, Sunday, December 13, 2015
Another fast-moving winter storm will become more intense as it moves eastward from Colorado into the Great Plains late Monday night and Tuesday. The current expected track puts the greatest risk for a period of heavy snow and wind in eastern Wyoming (including Cheyenne), with lower risk of heavy snow in the Denver-Boulder-Fort Collins corridor, and very low risk from Colorado Springs south.
Will update tomorrow. Right now most probable looks like:
- Cheyenne: about 6 inches, locally up to 10, with blowing snow, peak snowfall rates early Tuesday
- Denver-Boulder-Fort Collins: 1-4 inches, mainly Tuesday morning
- Colorado Springs: 0-2 inches
The annual Geminid meteor shower peaks in the pre-dawn hours on Monday. It’s one of the two best meteor showers of the year (the other being the Perseids in August).
12:15 PM, Friday, December 11, 2015
A intensifying storm system will track through Colorado tonight and become a potent storm as it moves east of the Front Range Saturday afternoon. The Front Range region will likely see at least a period of snow Saturday, and a generally cloudy and cold day.
Mountain accumulation Friday-Saturday: 6-10 inches near the continental divide, 3-6 inches foothills (including Nederland)
Lower elevation accumulations (mainly Saturday, maybe a little Friday night):
- 60% chance for 2-5 inches (including Colo Springs-Denver-Boulder-Fort Collins- Cheyenne)
- 20% chance of more than 5 inches due to a period of localized heavy snow (in a small portion of the area)
- 20% chance of less than 2 inches (a little greater chance for this outcome in Colorado Springs).
Why are strong storms not producing big snows?
We have been in a pattern since early November of intense storm systems that do most of their intensification as they pull east of the Front Range. This limits the “upslope” flow and most of the region gets a relatively minor snowfall, while a small portion (not necessarily near the foothills) gets a period of intense snow. One of these times we might get surprised with widespread heavy snow, but I don’t think it’s this time.
Another strong storm system is due in the area late Monday, but once again it may not be the kind to produce widespread high impact snow. But it’s still worth watching.