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918 FXUS65 KBOU 301141 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 441 AM MST Tue Dec 30 2025 .KEY MESSAGES... - Warming trend through Wednesday with dry and mostly sunny conditions. - Light snow expected for the mountains Thursday afternoon through Friday, favoring the Park Range. - The lower elevations will remain warm and dry through the weekend. && .UPDATE... Issued at 240 AM MST Tue Dec 30 2025 Weak northwesterly flow aloft will be in place over the CWA today and tonight with an upper ridge to the immediate southwest and west of Colorado. The cooler air has moved off to east with high temperatures expected to warm to a bit above seasonal normals today. Little to no cloudiness is expected today. Will make minor grid changes to temperatures only. && .DISCUSSION /Through Monday/... Issued at 108 PM MST Mon Dec 29 2025 A cool airmass remains firmly in place today, easily giving us our coldest day of the upcoming week, with much of the lower elevations surrounding the Denver metro and South Platte River Valley still in the 30`s as they sit below a lingering inversion. That cold air will begin to scour out notably on Tuesday as high pressure over the western CONUS encroaches on Colorado, including in our mountains. The high valleys, although not quite as cold as this morning when they saw temperatures dip into the -10 to -20F range, will remain cold tonight with the coldest locations dropping below zero. Meanwhile the lower elevations should climb into the low to mid 50`s, with abundant sun throughout the region. Temperatures will continue to warm into Wednesday as high pressure expands eastward. Expect continued dry conditions will only a modest increase in cloud cover. Dry and much warmer than normal conditions will extend all the way through this weekend for our plains and urban corridor, with very minor day-to-day temperature fluctuations. Conversely, the mountains will have a more distinct change come Thursday afternoon into Friday, when a transition to westerly flow aloft and the emergence of a weak shortwave most prominent at the 700b level will boost moisture and bring some light snowfall. Beyond the increased moisture and modest orographic flow, there will be little in the way of synoptic support to enhance snowfall, so accumulations and travel impacts should be relatively minor. The Park Range will again be favored in this pattern, with approximately a 75% chance of exceeding 4" of snow. Those probabilities drop to less than 10% for the I-70 corridor. Forecast confidence for the high country in particular decreases considerably for the weekend and beyond with many mixed signals in ensemble guidance. && .AVIATION /12Z TAFS through 12Z Wednesday/... Issued at 439 AM MST Tue Dec 30 2025 Models continue to show weak, normal diurnal wind patterns at DIA today and tonight. There will be no ceiling issues. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...66 DISCUSSION...BRQ AVIATION...66