Sunday and Monday
The weather over Colorado has been perfect on Friday and Saturday, and this perfect weather will continue on Sunday and Monday.
During Sunday and Monday, expect sunny skies and no precipitation. The only less-than-perfect weather will be over the mountains of the northern continental divide (near Longs Peak) where there will be gusty winds on Sunday of up to 40-50mph.
Tuesday and Wednesday
Moisture from Tropical Storm Paine will move from Baja toward Colorado.
Tuesday’s weather should stay dry for most of the state, though we’ll see more clouds and there could be afternoon, evening, or overnight showers as the moisture approaches.
These showers could stick around through Wednesday morning and/or during the day on Wednesday. It’s a bit too soon to have high confidence in this forecast, so stay tuned. The southern mountains will likely see the most showers while the central and northern mountains may stay on the drier side.
Late-week snow storm?
All mid-range weather forecast models predict that a cold storm will head toward Colorado on Friday and Saturday.
Ahead of this storm, Thursday looks windy and potentially dry for most mountains. Please pay attention to the wildfire risk. Dry, windy air is the perfect environment for a few embers to turn into a massive blaze.
The leading edge of the cold air should hit Colorado sometime between Thursday night and Friday afternoon. Temperatures should be cold enough on Friday and Saturday for snow to accumulate down to 10,000 feet, and perhaps down to 9,000 feet.
Behind the scenes - ensemble forecasts
Because the storm is still many days away, we cannot have high confidence in the exact track and temperature of the storm. If it drops a bit further south, most mountains would see significant snow. If the storm stays further north, the central and northern mountains may only get a dusting to a few inches.
To see many possibilities for the storm, we should look at the ensemble forecast, which shows multiple forecasts from one model. Each forecast is the result of small tweaks made to the model.
The forecast below is for snowfall for the next week, predicted by 22 ensemble forecasts of the GFS model. By my rough count, about 13 of the forecasts show the chance for 6+ inches of snow for most mountains, with 9 forecasts showing much less snow.
A count of 13 snowy forecasts versus 22 total forecasts equals a 59% chance of the Colorado mountains getting a somewhat significant snow storm on Friday and Saturday.
The European ensemble forecast (which I can’t show due to licensing restrictions) yields similar odds (about 60%) for 6+ inches of snow across Colorado later this week.
What we do know about the storm
I have high confidence that we’ll see a storm from Thursday night through at least Saturday, and that this storm will bring cooler air with snow falling down to at least 10,000 feet.
What we don’t know about the storm
I have low confidence about the total snowfall from the storm. Odds are slightly better than 50/50 that many mountains see 6+ inches of snow. The best chances for higher amounts will likely be in the northern mountains.
Planning something for next weekend (Sep 24-25)?
Next weekend looks to be on the chillier side with snow on the ground at high-elevation, at least for northern Colorado. Central and southern Colorado may revert to drier and warmer weather if the storm moves quickly to the east.
A similar storm to the one later this week may hit Colorado later the following week, around September 30th (+/- a few days). Winter is a comin’!
Shameless Plug - Consider upgrading to OpenSnow All-Access
If you’re looking for a way to support OpenSnow and get useful additional insight this winter, consider signing up for the All-Access Pass.
This pass gives you access to:
- 10-day forecasts
- Custom alerts to know about upcoming powder days
- Time-lapse webcams for tracking exactly when fresh snow has fallen
- Email delivery of the Colorado Daily Snow as soon as it’s published
All of this costs just $19 for one full year (365 days) and helps to support OpenSnow so that we can spend money and time to further improve our website and mobile apps. I’d love to count you as an All-Access member!
Thanks for reading and getting excited about winter!
Announcement - Heli Ski Event in Denver on October 6
Join me in Denver on Thursday, October 6th to learn more about heli-skiing with Canadian Mountain Holidays (CMH). I'll talk about my previous trips with CMH, they will show a premiere of their new short film, and refreshments will be served! This is always a fun event, so if you're interested in taking a heli ski trip this season or sometime soon, I hope you can make it! Please RSVP here: http://opsw.co/CMHDenverOct62016
Announcement - New Hiking Weather App!
I have been dreaming of building a weather forecasting app for hikers for years, and we finally had the time and funds to start the effort at the beginning of this summer.
The app provides hourly forecasts for each 14,000 foot peak in Colorado, including the chance of lightning, precipitation, summit temperature, and summit wind speed.
Also, and I find this super cool, the app shows recent Instagram pictures taken near each mountain. You can quickly see the trail conditions (is there snow?) by looking at these recent pictures.
This is version 1.0 of the app, and for now it is exclusively available as an app for iPhone. If you have an iPhone, and you like to hike 14ers, I would be thankful if you would download the app, play with it, leave a (hopefully positive) review, and send us lots of feedback to [email protected].
We have big plans for OpenSummit, and your feedback at this very early stage will be incredibly helpful. While we will be focusing most of our time on OpenSnow during the winter, we will take your feedback, improve OpenSummit over the next 6 months, and hope to have even more features ready for next spring.
Download the app here: http://opsw.co/OpenSummitapp