Active pattern for parts of the state over the next 5 days. Here is a look at the forecast details for the next 48hrs. Flooding concerns in southwest CO.

10/21/26 8am: Quite a bit of weather to talk about, but lets focus in on the next 48hrs. Models show a complex forecast with multiple waves. Uncertainty in the details in high as we head towards Sat.

Still looking at a big precip event for western / southwestern CO (heavy rain with snow above 12k ft) from about 3pm today (Wed) through 6am Fri with multiple waves and some flooding concerns in parts of the San Juans.

Much of southwest CO (south of a line from Telluride to Lake City) is under a Flash Flood Watch from 12pm today through 12pm Thu (this includes Durango, Cortez, Silverton, Pagosa Springs, Wolf Creek Pass, etc), those areas could get 2-4" of rain by Fri am (more Sat/Sun as well).

Also looks like there will be some snow accum, mostly above 12k ft, from 6am Thu through 6am Fri (snow level may drop to 11k by late Thu / early Fri). There could be 8-16"+ for part of the upper San Juans.

The north-central mountains (I-70 corridor) will also have rounds of rain the next several day (snow above 12k). First wave from about 5pm this evening through 2am Thu. Second wave from about 10am Thu through 3am Fri.

Looks like parts of the Elks and upper Ten Mile Range, upper Gore, etc will get some snow late tonight 1-4", and more snow Thu into Fri, additional 1-4", mostly above 12k ft (snow level could drop below 11k ft by Thu night).

Den/Bou and the front-range is still looking at much lower precip amounts overall (too much downslope flow): best chance for some rain showers initially will be 3pm-11pm on Thu (best chances in/near the foothills and Palmer Divide).

Then really the best chances overall for Den/Bou and the front-range to see some rain will be during the second part of the storm system from 6pm Sat to 6am Sun.

And as of this morning, chances for snow in Den/Bou (front-range) on Sun into Mon seem diminished based on latest storm track...but the details are very murky right now. GFS still shows a cold-front interacting with the big low on Sun into Mon with more precip, ECMWF has it all north of CO by Sun pm into Mon, so who knows.

So you can see the main waves will be approx:

First wave:

3pm Wed to 2am Thu

Second wave:

9am Thu to 3am Fri

Then a second storm system will bring more rain/snow to much of the state (favoring the western CO and the mountains).

Third wave:

12pm Sat to 12pm Sun

Then depending on model run: possibly more rain/snow Sun night into Mon but that is very uncertain

That is all for now.

First image loop show forecast total liquid precip (rain / melted snow) over the next 48hrs (6am this morning to 6am Fri) from latest HRRR. Second image shows forecast total snowfall over the next 48hrs (through 6am Fri) from latest HRRR, take amounts with a grain of salt. Third image shows where the current Flash Flood Watches are. Fourth image shows forecast total liquid precip from now through Tue am from latest NWS Blend of Models...you can see somewhat of a donut hole over northeast CO, sigh.