National Weather Service Forecast Discussion |
Thornton Weather Forecast Today's Forecast Story |
555 FXUS65 KBOU 250523 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 1023 PM MST Wed Dec 24 2025 .KEY MESSAGES... - Warm and dry for the plains through Friday with record high temperatures likely - The mountains will see light snow with the valleys seeing light rain/snow showers Thursday into Friday. - Increased fire danger Friday for the foothills and portions of the urban corridor. - A widespread snow possible for our whole forecast area Saturday night into Sunday with light amounts. Much colder temperatures expected to accompany the snow. && .DISCUSSION /Through Wednesday/... Issued at 214 PM MST Wed Dec 24 2025 Record or near-record highs are forecast on Christmas Day with most of the urban corridor seeing highs in the upper 60s to low 70s. The record high in Denver is 69 set in 2005 and that will likely (70% chance) be tied or broken. In the mountains, it will be mild with a chance of snow as a trough will approach Colorado from the west. The Park Range may get 2-5" of snow from these brief but intense snow showers that are expected. Other locations along the western slope of the Front Range mountains may see 1-3". Otherwise, a mountain wave will setup over the Front Range mountains late tonight and will last through much of the day Thursday. This wave will produce gusts between 50-60 mph over most of the mountains and foothills with some higher values in the windy locations of Boulder and Larimer Counties. On Friday, a similar weather pattern will be in place. Highs will be similarly warm with record highs possible. Drier air will move into our forecast area which will limit the snow potential in the mountains. However, a couple inches of additional snow accumulation is possible in the Park Range as the best moisture will stay that far north. The mild and dry conditions Thursday and Friday along with the gusty mountain wave will lead to elevated to near-critical fire weather conditions especially on Friday. This is discussed in detail in the fire weather section below. A strong positively-tilted trough will move into western Colorado on Saturday. There will be cold air advection in the low levels which will lead to cooler temperatures on Saturday (but still above normal). On Saturday night, a cold front associated with this trough will move through our forecast area. This will drop temperatures significantly with highs on Sunday potentially staying in the 20s across lower elevations. There will be a brief period of an over-running snow event Saturday night into Sunday across the plains and foothills. Southwesterly flow aloft with good mid-level frontogenesis will develop a couple bands of snow. Models have been trending toward higher QPF amounts for this system roughly in the 0.15-0.25" range for the Denver metro. The confidence of a light snow is increasing with a broad range of forecast values from 1-4" of snow across the I-25 corridor with the higher values being closer to the Palmer Divide due to upslope, northeasterly flow. In the mountains and foothills, higher amounts are expected potentially exceeding 6" above 10,000 feet. Sunday night will be cold due to fresh snow cover and clearing skies. Lows could reach the single digits across the plains. The pattern returns to warm and dry for the majority of next work week. && .AVIATION /06Z TAFS through 06Z Friday/... Issued at 1020 PM MST Wed Dec 24 2025 Winds will remaon drainage overnight thru Thursday morning. In the 19Z-20Z time period winds will become WSW at APA, North at DIA and West at BJC. By 23Z winds will become light NW or WNW and then switch to drainage by 02z Thu evening. VFR conditions will remain in place thru the period. && .FIRE WEATHER... Issued at 214 PM MST Wed Dec 24 2025 Thursday will be windy in the Front Range mountains and foothills with gusts between 50-60 mph. Winds will be lighter across the plains with gusts mainly staying below 25 mph. The exception to that are locations near the Cheyenne Ridge and Palmer Divide where gusts could reach 35 mph. Relative humidity is expected to increase as moisture from an approaching low pressure system will move into Colorado. Minimum relative humidity is expected to stay above 20 percent across all of our forecast area. Some pockets of elevated fire weather conditions may develop in the lower foothills and near the Cheyenne Ridge but no critical conditions are expected. Drier air will move in on Friday along with mild conditions. Minimum relative humidity will drop to 10-15% in the lower foothills and adjacent plains. Gusty winds will accompany the dry air and near-critical fire weather conditions are expected for the lower foothills and I-25 corridor. The magnitude of the wind gusts are in question so no fire weather highlights were issued at this time. Wind gusts may reach close to 50 mph in those locations or, if the mountain wave stays at higher elevations, gusts could stay around 25-35 mph. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Danielson AVIATION...RPK FIRE WEATHER...Danielson