Deep moisture and rain moving into CO now. Active pattern with rain/snow through the weekend into next week

10/10/25 8:45am: Good morning, happy Friday! Its already raining in the mountains. Look at that deep moisture plume moving into CO from the southwest (tapping into that Pacific moisture). Its also pretty warm as expected. For example looking at mountain station observations, temps are in the upper 30s near/above 12k ft (same with the dewpoints), so all rain.

First round of rain is underway and rotating across central CO now. This first batch will lift north through mid-morning and then likely a break in the action before the next round this afternoon.

Next more significant round of rain for western and southern CO (and parts of the central mountains) will be from 2pm-11pm today (Friday).

For Den/Bou and the front-range also looks like a better chance for some scattered rain showers and weak thunderstorms from 4pm-10pm today, best chances in/near the foothills.

Rain will continue overnight in the San Juans up to the Elks.

Then the next round of heavier rain is expected primarily from 6am-6pm Saturday with heaviest rain expected along/south of I-70 and over southern / western CO again (but central mountains will also get rain showers).

Den/Bou and the front-range will also have another chance for rain showers on Sat: 11am-5pm, best chances from Palmer Divide south.

Then model show a third round of rain/snow associated with a cold-front moving across north-central CO on Sun morning primarily from 4am-12pm on Sun....

On Sun am the snow-level will drop to 9k ft with some snow for parts of northwest CO and the north-central mountains, favoring areas from near Steamboat to the Flat Tops (maybe 1-5" of new snow in those areas by Sun mid-day).

Higher parts of the north-central mountains around Eagle, Summit, Grand counties will also get a little bit of snow at higher elevations on Sun am (but only 1-3" in a few spots).

Looking ahead, I see a pretty active weather pattern for next week:

Models show another surge of tropical like moisture coming up from the south on Mon night into Tue afternoon, with some heavier rain for parts of the state (and high snow-levels again), favoring southwest CO / San Juans

Then by next Wed/Thu and towards the weekend (10/15 through 10/21), models show a series of colder storms, coming in on more of a northwest flow pattern and will likely bring in some measurable snow for the north-central mountains towards the end of next week and into the weekend. It will remain active.

That is all for now. Below is some of my post from last night talking about why the snow-level is so high and some other main points about the storm

First image shows latest regional satellite loop over the southwest U.S. Second image is current composite radar over the state. Third image is latest surface map over the state showing current temps, dewpt, wind-speed and precip. Image 4 shows forecast total liquid precip from now through 6am Sun from latest HRRR, image 5 is equivalent but for total snow (note that the heavier precip and snow for northwest CO, near Steamboat, etc is expected to come in early Sun morning with the third part of the storm system).

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From 10/09 pm:

"I just don't see much snow and the main issue is that the models are forecasting wet-bulb freezing temp to rise to nearly 14-15k Fri night into Sat and really through most of the event until Sun am. Wet bulb temp takes into account T and RH and is crucial for determining the snow-level.

So with that in mind most of the models only show a little bit of snow overall, mostly above 13k ft. Parts of the western San Juans (upper Weminuche Wilderness with the 14ers) may get 3-9" of snow way up high. Models also show some snow across upper parts of Elks, Sawatch, Gore, Tenmile Ranges from Fri evening through Sun am, but only 1-5" in spots (mostly above 13k).

Anyway, forecast is on track. There will be a round of heavy rain over western / southwestern CO tomorrow: 6am-9pm. Then another round of Saturday: 12am-10pm. There could be 2-4" of rain for parts of the southern / western San Juans.

Won't be nearly as intense for most of the rest of the north-central mountains but some rain Fri afternoon and Sat afternoon.

Some areas that may not get much rain include Den/Bou and the front-range, eastern plains. As well as areas like SLV / Alamosa and even the very middle of Summit Co (including Frisco, Silverthorne, Dillon)...these areas do not do well with southwest flow (too much downslope)....so the forecast will trend towards cloudy with some showers at times, but not much for those areas (but some rain at times)

Otherwise pretty rainy for western and southern CO from say Vail west and south (especially from Aspen south). Also very rainy for areas near Moab and eastern UT, etc."