Some latest model data for the Thu-Sat storm, looking potent

04/15/25 8:50pm: Lets take a look at some of the latest model data for the Thu night through Sat night storm system....its looking like a classic April snow-storm for much of the state, including Den/Bou and the front-range.

Models are in better agreement and showing a more favorable track with the main low dropping into UT from the northwest, then moving from near the 4-corners across northern NM and then bending back northeast towards KS...this will produce a good shot of cold upslope along the front-range (Den/Bou) and even heavier snow over the mountains (lots of lift with this one and cold-air for mid-April). Also looks like much of southern CO will get some good rain and snow as well during the second half of the event.

First, still expecting a round of scattered rain/snow showers for the mountains after 12pm tomorrow continuing into Thu morning (Trace-2" in spots)

Here are some trends I'm seeing with the Thu through Sat storm system

• Main impacts will be from 6pm Thu through 6pm Sat (two waves, heaviest Fri am)

• Looks like a pretty juicy event with models showing generally 0.5" to 1.0" of liquid precip for Den/Bou and the front-range and 0.75" to 2.0" of liquid precip for the mountains and foothills (mostly as snow)

• It now looks like the cold air moves into the front-range sooner rather than later, with likely a change over to all snow in Den/Bou/Ft.Collins between 9-11pm Thu then heavy snow likely from 11pm Thu through 5am Sat and snow may linger through Sat evening depending on the storm track

• Snow amounts are uncertain for the front-range but looks like Den/Bou and the urban corridor could get 2-6" of snow with 4-10"+ for the foothills. GFS shows heaviest snow further south (towards Springs), ECMWF on the other hand has it further north (Den to Ft. Collins)

• Look like much of the north-central mountains are going to get some very heavy snow from 6am Fri through 6pm Sat...many of the models now show 8-16"+ of new snow for the ski areas, mountain passes and higher terrain, favoring areas west of Vail Pass and along/south of I-70, secondarily over the Front Range mountains (along/east of the Cont. Divide)...hard to say where that bullseye will be

• Also looks like very heavy snow in spots from Aspen to CB to especially Silverton and Telluride and even Wolf Creek will also likely get 10-20" of new snow with up to 2ft in spots (likely favoring western San Juans but hard to pin down at moment)

• Southeast CO from Pueblo to Trinidad will be favored for heaviest snow from 11pm Fri through 6am Sun (also some good snowfall down there)

• Looking ahead more snow expected for the north-central mountains from 3pm Mon through 12pm Tue (with some good snow accum as well, more on that later)

First image shows the upper-level low in a good spot at 6pm Fri from latest ECMWF (look how the big trough is tilting forward: positive, that is always good for the front-range in terms of rain/snow). Image 2 shows forecast total liquid precip from now through 6am Sun from latest NWS Blend of Models, shows overall trends. Images 3-5 compare forecast total snowfall from now through 6am Sun from latest ECMWF, ICON and GFS, take amounts with big grain of salt as details will change.