Snowfall map for the Fri to Sun storm

01/23/25 8:45pm: Alright, here is my preliminary total snowfall map for the Fri to Sun storm system. I will say uncertainty in the details remains high this evening as its a complex flow pattern with this storm. I'll let the map mostly speak for itself.

Initially starting tomorrow afternoon the focus for snowfall will be over northern / northwest CO (Park Range to Medicine Bow Range).

Then as the jet-stream sags south with an upper-level low moving in well to the west of CO...this will put the focus with best cold air, moisture and lift onto the front-range: looks like a good southeast upslope event for the northern front-range (Den/Bou/Ft.Collins) on Fri night into Sat

For this first part of the storm system with the southeast flow, not a great wind-flow pattern for the north-central mountains near Grand, Summit, Eagle counties etc so lighter snow Fri into Sat for the mountains. Then as the flow turns more westerly on Sat evening into Sun better snowfall accumulation for the ski areas / I-70 mountain corridor

General timing: For the north-central mountains snow from 2pm Fri to 5pm Sun. Generally 3-10" for the local ski areas with highest amounts along/east of the Cont. Divide. Highest amounts overall expected in northern IPW to RMNP to Cameron Pass, up to 14" in spots there (also Park Range north of Steamboat up to 14" as well, with heavier snow on the front-side of the system)

For Den/Bou/Ft.Collins, foothills and the front-range looks like a good chance for snow from 12am Sat to 2am Sun with heaviest snowfall Sat mid-morning through afternoon. Generally 2-6" for Den/Bou with highest amounts north of I-70 and west of I-25 and closer to Ft. Collins. Foothills can expect 4-12" with highest amounts in Boulder and Larimer county foothills. It will be cold on Sat with high temps in the low 20s.

Even though this part of the storm system through Sun pm won't bring much snow to southern CO...eventually the big low to our west will move east and bring a round of heavy snow to much of southern CO likely in the next Tue/Wed timeframe (6-12" in spots next week).

First image is my initial snowfall map from now through 5pm Sun. Images 3 and 4 compare forecast total snowfall from latest ECMWF and GFS models (take amounts with grain of salt). Fourth image loop shows the complex flow pattern with this storm via 700mb temps/wind from ECMWF over the next 7 days (static image valid at 2pm Sat).