Forecast for the weekend and into next week: spring this weekend, winter next week

02/28/25 8:30am: Lets get back to some wx forecasting. Happy Friday, can't believe its the last day of February! Going to be nice and warm weather today and tomorrow before changes start to arrive by Sun and then a shift back to a more active wx pattern next week with a larger storm system slated to impact the state form Mon night through Tue night with rain/snow for both the mountains and front-range. Then possibly another storm for Thu into Fri but that is more uncertain. Overall uncertainty is high in the details. But here are some main points

• Sunny and warm across the state today and tomorrow with temps in the upper 60s for Den/Bou (40s for the mountains). Light wind as well everywhere.

• A weak storm system will move across southern CO late Sat night into Sun.... this will bring some rain/snow showers to southern CO: San Juans to Elks from 2am-5pm Sun: Trace-3" of snow in spots down there (most of the action south of I-70).

• For the north-central mountains just a few snow showers on Sun afternoon / evening, won't be much

• Then a larger disorganized trough moves in starting Mon afternoon / evening

• For the north-central mountains rounds of snow likely from 2pm Mon through 2am Wed (two waves of snow likely), generally looks like 6-12" of snow for the local ski areas in that time-frame with the highest amounts from Summit co east and most likely over the Front Range mountains (along/east of the Cont. Divide) uncertainty is high in details

• For Den/Bou and the front-range rain showers develop after 8pm Mon. Then a cold-front will move down the front-range on Tue am and change rain to snow. Looks like a decent chance for snow from about 2am-2pm Tue: Could be 2-5" for Den/Bou favoring the western and southern metro areas again (west of I-25) and foothills could get 3-8" in spots. Uncertainty is very high as GFS shows more downslope flow and much less snow (ECMWF has a good amount)

• Looking ahead snow showers linger in the mountains through Wed morning

• Then the forecast becomes much more uncertain for the end of next week. ECMWF (and GEM to some degree) show another storm system impacting CO from about 12am Thu through 11am Fri: possibly another round of moderate snow for the north-central mountains (heaviest on Thu night)

• And for Den/Bou and front-range maybe some more rain/snow or snow on Thu afternoon into Fri am (with best chances late Thu night as well), high uncertainty

First image loop shows the evolution of the forecast pattern over the next 8 days via 500mb vorticity / wind from latest GFS. Images 2 and 3 compare forecast total snowfall from now through 5am Wed (03/05) from latest ECMWF and GFS...take modeled snowfall amounts with big grain of salt, you can see there are some huge differences in the models right now.