Forecast for the next storm system: warm southwest flow event from Wed to Fri, favoring the San Juans / southern CO

10/18/26 10:30am: Hi, I hope you are having a good Sunday morning. Let's take a look at what we can expect with our next storm system that will impact parts of the state from Wed afternoon through Fri afternoon. We are looking at a southwest flow event with warm temps, favoring the San Juans.

Models show an upper-level low approaching the Great Basin (near the UT/AZ border) on Wed into Thu. But the storm tracks keep the main low west of CO (moving it from central Utah into WY on Thu/Fri). So this will keep CO under strong southwest flow with the biggest impacts over western / southwest CO, with limited impacts further east.

So we are looking at another big round of rain (and snow up high) for southwest CO, favoring the San Juans primarily from 12pm Wed through 6pm Thu. With biggest impacts / (main wave), Thu afternoon into Fri am. Even prior to this some lighter rain/snow showers move into western CO / San Juans after 12pm Tue.

Models show the potential for 2-3" of liquid precip over southwest CO, so there could be some flooding concerns in the San Juans on Wed, Thu and Fri, so heads up there.

Now the thing is we are looking at relatively warm temps especially Tue/ Wed into Thu. So initially we are looking at the snow-levels mostly above 12k ft through Thu am. Then the snow-level may drop to 10,500ft by Thu night into Fri. So some snow accum for parts of the San Juans, southern Elks, southern Sawatch and Grand Mesa areas but will be limited and much higher up.

North-central mountains will get some rain/snow mostly from 12pm Thu through 6pm Fri but it will be more limited and showery (some precip accum). High snow-levels as I mentioned. Best chances will be south of I-70 and west of Vail Pass.

And unfortunately with the forecast strong southwest flow aloft (and at the mid-levels) likely very little to no rain for Den/Bou and the front-range (too much southwest downslope flow). Best chance for a few showers would be on Thu afternoon / evening (at least turning cloudy).

Rain/snow showers could linger in the mountains into Sat am, then it will likely clear out.

Looking ahead, Next storm system arrives around Oct26th/27th but that could be a repeat of this one: strong southwest flow favoring southern CO, we shall see.

First image shows forecast total liquid precip from now through 12am Sat from very latest (06z) ECMWF model (take amounts with a big grain of salt, it will change some). Second image shows the overall storm track / flow with this next storm system. Image 3 shows forecast precip-type/rate at 3pm Thu from latest ECMWF model.