Expires:No;;341242 FXUS65 KBOU 272338 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 438 PM MST Sat Dec 27 2025 .KEY MESSAGES... - A cold front will bring below freezing temperatures to the forecast area Sunday morning. - Mountain snow continues into early Sunday morning. The heaviest snow will be in the Park and Gore Ranges where a Winter Storm Warning is in effect. Moderate amounts are expected across the Front Range mountains with a Winter Weather Advisory in effect. - Uncertainty in the snow amounts for the lower elevations from tonight into Sunday morning. Anticipate T-2" of snow expected on the east side of the I-25 corridor and 1-3" on the west side of the I-25 corridor. && .DISCUSSION /Through Saturday/... Issued at 255 PM MST Sat Dec 27 2025 Current water vapor imagery shows a stream of Pacific moisture moving into the high country, with snow showers ongoing in the Park Range and northern Front Range mountains. We expect snow to become more widespread this afternoon/evening as favorable orographics ahead of an approaching shortwave trough will promote light to moderate snowfall through tomorrow morning. Short and long range guidance still favor strong frontogenesis later today and overnight, which will create snowbands and promote localized heavy snowfall at times, particularly in the Park Range. Areas of blowing snow will be a concern, especially across high passes as winds could gust up to 50 mph. With reduced visiblities and slick roads, expect difficult to hazardous travel this evening through Sunday morning. Still think total accumulations will range between 8-18" in the Park and northern Gore Range and 4-12" along the Front Range, with highest accumulations north of I-70. For the plains, the trend is not our friend unfortunately as expected snowfall amounts have decreased in the last 24 hours. A strong cold front is progged to enter our forecast area this evening and tonight, bringing gusty north/northeasterly winds and colder temperatures. Ahead of this front, light rain and rain/snow mix will occur before the cold air overcomes warm temperatures and allow light snowfall. Most short range guidance have all trended towards a slightly warmer and drier airmass at the lower levels, with total snowfall accumulations between trace to a couple tenths, and best area for snowfall across the Palmer Divide. However, long range guidance has held relatively steady in areas along the lower foothills/plains receiving a couple of inches by Sunday. Most likely, the northern and eastern plains will receive a dusting to an inch of snow by late Sunday morning. Due to favorable upsloping and frontogenetical forcing, the Denver metro, western urban corridor, and Palmer Divide could see slightly more accumulations. Lastly, any banded snowfall will create localized higher amounts (up to 2-3"). As temperatures are expected to dip below freezing tonight and Sunday morning, expect slick roads wherever precipitation falls. Snow will gradually end late Sunday morning. Temperatures will stay below freezing throughout the day, with low 30s as expected highs across the plains, and single digits to mid teens for the high country. Quieter conditions are expected Monday and through the rest of the week. Ensemble guidance has continued to indicate Colorado on the eastern edge of an upper level ridge with a surface high pressure settling over the western United States. With weak northwest flow aloft, dry and warming conditions will prevail. Monday and Tuesday will see near seasonal temperatures, with highs in the 40s both days across the plains. Then, as the axis of the upper level ridge shifts over Colorado towards the later half of the week, temperatures should warm up to the mid-to-high 50s. Despite dry conditions allowing relative humidity values to drop to 20% almost each day, recent precipitation and relatively light winds should keep fire weather concerns at bay. However, can't rule out localized elevated fire weather conditions, particularly in areas that don't receive precipitation. Our next chance of precipitation comes towards the end of the week/weekend, as ensemble solutions show an upper level trough trekking over northern Colorado. As of right now, the bulk of the precipitation is expected to be confined to the high country. However, will continue to monitor for any changes. && .AVIATION /00Z TAFS through 00Z Monday/... Issued at 431 PM MST Sat Dec 27 2025 Cold front still expected to arrive close to 06z tonight, with some stratus filling in behind the front. Recent trends are drier across the metro tonight into Sunday AM but there should be a mix of SCT/BKN 020-040 along with a few bands of light snow. There could be periods of MVFR or IFR conditions through about 15z before a gradual clearing is anticipated. Gusty NNE winds are expected with the cold front initially, with some sort of northerly component continuing through the day Sunday. && .BOU WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning until 5 AM MST Sunday for COZ031. Winter Weather Advisory until 11 AM MST Sunday for COZ033-034. && $$ DISCUSSION...MAI AVIATION...Hiris