07/13/26 8pm: Hi. Good to see some stronger signals showing up in the model data for the return of some deeper monsoon moisture and much better rain chances across the state especially in the 07/18 to 07/25 timeframe with some rain for the mountains before this. Also fun to look at some new model data via WeatherBell.

Informative to look at the ECMWF Ensemble chicklet charts for 24hr accumulated precip, comparing previous model runs to the very latest model runs. When you line up the valid-time (the day into the future) you can see strong signals across a wide run of ensemble members and this gives more confidence in the event occurring.

Below I show the charts for Boulder (front-range), Berthoud (central mountains) and Wolf Creek Pass (southwest CO / San Juans) and you can clearly see the signals increasing for rain.

Now one thing to keep in mind is: we are dealing with convection / thunderstorms and it is hard to predict exactly where the strongest cores will be and the heaviest rain will fall and we know it can be very hit or miss with heavy rain right next to dry. But we use the ensemble signals to indicate when better rain chances will occur.

Basically once the moisture is in place we are looking at afternoon storms in the mountains from 12pm-8pm and the plains generally from 1pm-9pm each day.

For the north-central mountains (including Eagle, Summit, Grand, ClearCreek, IPW, RMNP, etc) better chances for isolated to scattered storms Wed to Fri initially. But then the best chances will likely be from Sat 07/18 to Sat 07/25 (peaking early next week, Mon/Tue looks juicy).

For the south-central / southwest mountains and San Juans initially a good chance for scattered storms Wed-Fri (even a few tomorrow), you can see the separate box for this for Wolf Creek Pass. Then a good chance for afternoon storms from 07/19-07/24 each afternoon (could start as early as 11am some days).

For Den/Bou and the front-range it will take a bit longer for the deeper moisture to move in, but best chances appear to be from 07/20 to 07/25 (Mon-Sat next week), could be some heavier rain Mon, Tue and Wed afternoons we shall see, fingers crossed. We won't know the details until this weekend.

Lastly I also include forecast total liquid precip from now through next Wed (07/22) from latest NWS Blend of Models for the entire southwest region. Take amounts with a big grain of salt (it will not fall like this) but gives an idea of where has the best chances for heavy rain will be, it will still be hit or miss thunderstorms, you know the game!

Also look at how big the signals are for AZ and parts of NM, they will have even better monsoon flow down there (as usual with the North American Monsoon).

But you can see we have better rain chances coming up and I'm stoked on that, fingers crossed.

Questions?

First chart is for Berthoud Pass, second for Wolf Creek Pass and third for Boulder (I added some labels and boxes for better viewing, it will nice to use these going forward, especially for snow-storms).