National Weather Service Forecast Discussion |
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102 FXUS65 KBOU 181007 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 307 AM MST Sun Jan 18 2026 .KEY MESSAGES... - Light snow expected this evening through early Monday morning, possibly leading to poor travel conditions for Monday morning. - Otherwise more tranquil weather Tuesday onward. Still dry through much of the week ahead. && .UPDATE... Issued at 305 AM MST Sun Jan 18 2026 Only a few minor changes to the forecast for today and tomorrow. Winds were increased in portions of the foothills for the next couple of hours. The stronger winds currently extend as far east as KBJC, with gusts around 30 to 40 mph. These gusty winds are expected to retreat westward into the mountains starting around 4AM. A cold front will move south out of Canada early this morning, moving into northern Colorado by this evening. Snow chances start in our northern plains and mountains around 5PM, increasing and pushing south as we go into the overnight hours. Models continue to show decent conditions for the development of light snow today, including weak frontogenesis, lift from the right entrance region of the upper jet, increasing moisture in the column, and weak upslope flow. Because of this, confidence has increased in the potential for light snow accumulations across the I-25 corridor, metro, and eastern plains. PoPs were increased starting Sunday afternoon and continuing into late Monday morning, with a peak in chances overnight Sunday into early Monday. Snow amounts remain generally the same as the previous package, with amounts around a trace to 2 inches for much of our area. I will say, there is still quite a bit of uncertainty in the potential development and location of heavier snow bands. If a heavier snow band does develop, we could see localized areas with higher snow amounts (closer to 3 inches). Denver snow totals are currently sitting around half an inch to an inch for this event, which could lead to difficult travel conditions for the Monday morning commute. && .DISCUSSION /Through Saturday/... Issued at 215 PM MST Sat Jan 17 2026 Exceptionally dry air has moved across our forecast area with dew points down to -19 F across the plains. Despite the cool conditions, relative humidity has fallen to as low as 11 percent. Conditions have met red flag criteria across the majority of the plains. Winds will weaken quickly right before sunset and the Red Flag Warning may be able to be canceled a bit early. Brief ridging aloft will move over Colorado on Sunday leading to a mild day. Downslope winds will allow high temperatures to reach the low 50s across the plains. A quick-moving through will pass through northeast Colorado late Sunday night. There will be PVA and low level frontogenesis that will combine to create lift. A band or two of snow will form across northeast Colorado late Sunday evening. This system will not have much moisture with it but snow ratios will be favorable due to a relatively deep dendritic growth zone. NBM had PoPs and QPF that were too low so those values were increased. The forecast snowfall is between a trace and 2" for the majority of the I-25 corridor, eastern plains, and foothills. The mountains may see a bit more snowfall and the far northeast plains by Nebraska may see no accumulation. The snow may lead to poor travel conditions Monday morning due to snow-covered and slick roads. The northwesterly flow aloft will continue throughout the rest of the work week. Minor shortwave troughs may bring very light snow a couple more times throughout the week. Temperatures will go back and forth between 5-10 F above normal to 5-10 below normal. No other significant impacts are expected. && .AVIATION /06Z TAFS through 06Z Monday/... Issued at 1040 PM MST Sat Jan 17 2026 Southwest winds at KDEN and KAPA will turn more westerly over the next couple of hours. Winds at KDEN will continue to veer into the afternoon, turning WNW by the early morning, N by the late morning, and NNE by the early afternoon. Winds at KAPA will follow a similar pattern to KDEN, but will likely have a few hours of variable winds in the morning before turning north. KBJC is currently gusting out of the west around 24kts. This will continue through much of the overnight period, before the stronger winds start to retreat back towards the mountains around 11Z, leaving variable light winds with occasional westerly gusts for the rest of the morning. A weak cold front will move into the area in the evening turning winds more ENE for the rest of this TAF package. Ceilings will start to drop in the evening as well, approaching MVFR CIGs around 6Z, give or take an hour. Snow showers are expected around 6Z as well. With these snow showers, we could see drops in visiblities(~2sm) and lower cloud decks(approaching 1000ft). && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...AP DISCUSSION...Danielson AVIATION...AP