Forecast for the week: some storms today, turning more active: wetter and cooler by Fri into next week

08/18/25 9am: Morning, its Monday. We have some weather to talk about. Better thunderstorm chances for the front-range and eastern plains today as a little short-wave rotates up across the state (part of a dirty ridge). Then back to hot and mostly dry conditions for Tue-Thu. Then we are looking at a pattern change for the end of August into September with cooler and wetter conditions.

I see a more active pattern (in terms of better rainfall chances) with cooler temps overall from about this Friday, August 22nd through about Wed Aug 27th. Hard to pin down details but several cold-fronts for the front-range (starting this Thu night) and deeper / monsoon like moisture for the mountains (jet stream looks active as well).

First, did any of you get a little rain for the late night thunderstorms that moved through parts of the front-range (closer to Boulder) around 2am-4am last night? Some thunder and lightning in spots and a brief rain.

Anyway for Den/Bou and the front-range today a chance for scattered thunderstorms primarily from 2pm-7pm today. Storms will first form in the foothills west / southwest of Denver and along the Palmer Divide after 1pm and then spread east. Best chances for storms today will be from Denver south and east (PD and along/east of I-25 after 3pm). More isolated further northwest (closer to Boulder, etc).

In the mountains today, most of the thunderstorm action will be southeast of a line from Hoosier Pass to Wolf Creek: so parts of Collegiate Range, SLV, Sangres and towards Pikes peak has a chance for some storms 1pm-8pm. Otherwise not much coverage further north (for Eagle, Summit, Grand counties etc, just isolated storms after 2pm).

For tomorrow just some storms for the front-range mountains and foothills along/east of the Cont. Divide from RMNP to Pikes Peak to La Veta pass from 1pm-7pm.

Just very isolated storms tomorrow for Den/Bou and also for central mountains, most areas stay dry, warming up.

Then hot and dry for most of Wed and Thu. A cold-front will move down the front-range on Thu evening but likely not much storm activity initially (maybe some after 6pm on Thu).

But then a much better chance for rounds of afternoon storms starting Fri and continuing into Sat and Sun.

Better rain chances for the mountains (north and south) especially starting Sat and Sun continuing into next week.

Pattern next week will favor cooler and wetter weather for the front-range from Sun-Wed. Rounds of afternoon storms, high temps only in the low 80s for Den/Bou, with 60s in the mountains. More on all that later.

Later today, likely this evening I'll be posting my seasonal snowfall and temperature forecast for the winter for Colorado, so stay tuned for that.

First image loop shows forecast radar over the next 48hrs (6am this morning through 6am Wed) from latest HRRR model. Second image loop shows the evolution of the weather pattern via 700-300mb RH from now through Aug 27th....you can see the dry air (brown initially) turning to a much wetter (green) pattern with waves moving through starting this weekend. Images 3-5 show forecast 24hr liquid precip for Fri, Sat, Sun (ending the next morning at 6am each day), take with grain of salt but shows a much wetter pattern on tap coming up. Fingers crossed!