A look at the Wed/Thu storm system and some cold low temps last night

01/27/25 8:45am: Morning, its Monday. Another cold January morning out there but we have a nice warm up on the way over the next couple days before the next, southern track storm system impacts the state Wed/Thu.

First it was cold last night. Here are some notable low temps this morning:

Fraser Flat: -25

Walden: -18

Gunnison: -18

11 Mile Res (southeast of Fairplay): -16

La Salle (southeast of Greeley): -5

Frisco: -3

Alamosa: -2

Edwards: -2

Rocky Mtn Arsenal (Denver): 6

Westminster (my house): 8

Looking ahead: a nice warm up for Den/Bou and the front-range Today through most of Wed with temps getting back up into the upper 40s / low 50s. It will be nice across the north-central mountains as well through Wed am.

Then attention turns to the large upper-level low currently spinning to the southwest of CO (over parts of CA and AZ today). The big question is exactly where is this low going to track and how far north does the main circulation get on Wed into Thu....this will determine how far north the snow will fall on Wed into Thu...

Right now southern CO / San Juans and southeast CO from Springs south are favored for snow... Maybe some for Den/Bou and parts of the local mountains.

Some light snow moves back into the San Juans (Telluride, Silverton and towards Wolf Creek, etc) after 11pm this evening and continuing through the day Tue with 1-5" of new snowfall for some of the ski areas down there, favoring the western San Juans initially.

Then as the main low moves across northern NM / southern CO on Wed into Thu this will bring a round of snow to parts of southern CO and the front-range mostly from 5am Wed through 5pm Thu. Uncertainty is high in the details: San Juans and Sangres will likely get an additional 6-12" of new snow. SLV / Alamosa, parts of southeast CO from Springs across Pueblo to Trinidad will also get some good snowfall, likely 2-8" in spots.

For Den/Bou and the northern front-range uncertainty is high but a chance for some snow showers mostly on Wed night into Thu am, best chances from Denver south with a chance for Trace-2" in spots (maybe up to 2-4" for the Palmer Divide and southern foothills).

Parts of the north-central mountains mostly south of I-70 and parts of the southern Front Range mountains (mostly from Breck south) could get some snow on Wed into Thu as well: maybe: 1-3" in a few spots but uncertainty is high there as well.

First image loops shows the evolution of the pattern via 500mb vorticity / wind over the next 5 days (from now through Fri) from latest GFS...will all depend on where that low tracks. Second image shows low temps (min-T) since midnight across the state. Third image shows forecast precp-type/rate, mslp at 5pm Wed from GFS showing the southern track low. Images 4 and 5 compare forecast total snowfall from now through 11pm Fri from latest GFS and NWS Blend of Models, take snow amounts with big grain of salt, details need to be worked out still.