Upper level trough currently centered over northern NV is forecast to move slowly east across CO on Tuesday and Wednesday. Lots of mid level moisture out ahead of trough causing clouds and some light rain across western CO today, with some showers possible across the foothills as well. Rain amounts expected to be on the light side today. Heaviest rain expected to be Tuesday and Wednesday as upper trough moves through the state. Some isolated thunderstorms are possible, but mostly showers and light to moderate rain is expected. Rain amounts look to be in the 0.25 to 0.75 inches over the mountains and foothills, with 0.10 to 0.50 across the Urban Corridor and Plains. Heavier amounts are possible where thunderstorms pass. Snow level looks to remain above 12,000 ft, although small hail is possible in thunderstorms. Showers remain possible Thursday through Saturday, mostly in the afternoon as atmosphere remains relatively moist and slightly unstable, so isolated thunderstorms also possible.

Models predict an upper ridge will rebuild over the Pacific Northwest this weekend, which will create a dry and mild northerly flow over CO from Sunday into next week, so next week is expected to be sunny and mild across the state.

Next chance for precip looks to be the following weekend as an upper trough is forecast to move into the Great Basin and eventually across CO. Long range models indicate this to be our first chance for snow at lower elevations, although still a long ways out, so would not bet on this just yet.

Update Tuesday Sep 25

Upper level low with a closed circulation currently located in east central UT. Models forecast this upper level feature to move slowly east into west central CO this evening and then stall out in this location through Thursday, then eventually diminish and move east of CO on Friday. Thus, band of precip associated with the upper low currently in western CO, and a deformation band out ahead of the upper low currently along the foothills causing showers and isolated thunderstorms to develop in a moist and slightly unstable atmosphere. General trend will be for showers and thunderstorms to increase in coverage and intensity this afternoon and evening, then diminish overnight, although some activity may persist overnight, especially across north central and northeast CO. We should see a repeat of today on Wednesday with activity increasing during the afternoon and evening hours, and diminish Wednesday night, although activity may persist across the Plains on Wednesday night.

Models consistent in predicting 0.50 to 1.0 inches of precip for most foothill areas Tuesday-Wednesday. Snow level according to models should be around 11,000 to 12,000 ft, although snow level may lower to near 10,000 ft in heavier showers and thunderstorms. Any accumulations should remain above 11,000 ft where 2-6 inches of snow is possible.

Atmosphere looks to remain moist and slightly unstable Thursday through Sunday, so afternoon and evening showers will be psosible each day, although precip amounts expected to be lighter than Tuesday and Wednesday. Models then forecast a dry and mild pattern for early next week Monday through Wednesday. The latter part of next week under some debate now, as latest models bring an upper low into the Great Basin late next week, which may bring some moisture into CO. Will have to wait and see how models handle this progression.