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827 FXUS65 KBOU 212355 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 555 PM MDT Tue Oct 21 2025 .KEY MESSAGES... - Potential for some showers Thursday into Friday, with best chances in the mountains and across the Palmer Divide. - Potential for an impactful system Sunday and Monday of next week. Most likely impacts will be strong winds and mountain snowfall. && .DISCUSSION /Through Tuesday/... Issued at 318 PM MDT Tue Oct 21 2025 Skies will remain clear into Wednesday except for a few transient wave clouds. As the upper ridge and surface high drift eastward, winds on Wednesday may be even lighter than today`s, with little change in temperature. With clear skies, dry air, and light winds, cold spots should radiate well, so we lowered mountain valley temperatures. Most of the plains should be above freezing though, and those colder spots have had hard freezes already. Thursday will turn a little more active across the state, as a weak shortwave drifts into southwest Colorado during the day, then meanders across the southern half of the state Thursday night into Friday. This system looks fairly warm (snow levels generally AOA 9kft) and moisture starved, but is slow moving enough to at least produce some modest QPF/Snow across mainly the I-70 mountains through Friday. Forecast snow amounts are generally in the 1-4" range for the higher peaks, most of which falls Thursday afternoon into Thursday night. There could be a few showers that drift into the lower elevations, but any meaningful rainfall looks unlikely. Brief, weak ridging will attempt to develop on Saturday as the previous trough closes off into a weak upper low and stalls over the southern Great Plains. Mild temperatures are expected with highs near 70F for the Denver metro. We should see a transition towards a more active pattern for the end of the weekend into early next week, with one or more shortwaves rippling through increasingly strong west/northwest flow aloft. There`s a good signal across ensemble guidance for a brief shot of mountain snow late Sunday through most of Monday. There are a handful of ensemble members (