10/12/26 9:20am: Morning, its Monday. Aside from the much needed rain/snow with the approaching big upper-level low, we are finally going to get some chilly temps, some more proper mid-October temps.

Below I show some meteograms for both Boulder (for Den/Bou) and for Berthoud Pass (representing the north-central mountains). The bar graphs show daily max/min temps over the next 7 days. The other images show Max/Min 6Hr 2M Temp. + QPF + Snow (temps and precip / snow amounts every 6-hours).

For Boulder you can see high temps will only be in the low 50s Wed and then only the mid-40s on Thu and it looks like it could get below freezing (low of 28 from ECMWF) by Fri am.

There is also a chance for either a rain/snow mix or all snow falling for parts of the front-range lower elevations (Den/Bou) by early Fri am (so heads up there).

Snow looks likely in the foothills (above 6500ft) by late Wed night into Thu and through the day Thu into Fri am. Could be several inches of snow up higher in the foothills (heads up there).

If you look at the Berthoud Pass meteograms, it shows temps in the mid-30s on Wed then high temps only in the 20s on Thu with snow falling. And from the ECMWF meteogram: the potential for 6-10"+ of snow at Berthoud pass by Thu night.

Still looking at a juicy event overall: latest models runs have 0.50" to 1.50"+ liquid for much of northern CO, including the front-range (Den/Bou) and adjacent mountains. Latest ECMWF has > 2" in spots, GFS has more like 0.50" to 1.00" favoring areas north, so we shall see.

The other thing I'm seeing this morning is it looks like the main upper-level low is slowing down or will stall out a bit and now appears biggest impacts for the front-range (and deepest upslope) will be from Wed pm through Thu pm now.

But also some rain and upslope developing by Tue night. So likely a more prolonged event from 6pm Tue through 3am Fri now (biggest impacts Wed into Thu).

That is all for now, I'm getting excited for a big weather change, we need it!

See my forecast from last night for more details and statewide maps. Later tonight I'll likely post a preliminary snowfall forecast map (and we will look at the model data).