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459 FXUS65 KBOU 132033 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 233 PM MDT Fri Mar 13 2026 .KEY MESSAGES... - Gusty west winds, strongest Saturday, and warm/dry weather will sustain critical fire weather conditions for the plains/I-25 corridor through Saturday. The mountain valleys will see elevated fire weather conditions. - Difficult travel expected in the mountains Saturday night into Sunday morning due to snow and blowing snow. - A cold front Saturday night will bring sub-freezing temperatures with strong north winds and light snow to the lower elevations. - Rapid warming begins Monday into Tuesday, potentially culminating in record-breaking temperatures mid to late next week. && .DISCUSSION /Through Friday/... Issued at 212 PM MDT Fri Mar 13 2026 A shallow cold front pushed across the northeast plains this morning with east-northeast winds behind it. Unfortunately, this pushed smoke from the large Nebraska fires into northeast Colorado. Visibility in Greeley and Fort Morgan decreased to as low as 1 mile with poor air quality. Sunshine has allowed temperatures across northeast Colorado to warm into the 60s which has improved mixing and visibility and air quality as well. With the improved mixing, west winds will increase soon and the smoke will leave northeast Colorado. The Red Flag Warning is on track today. The fire weather conditions are discussed further in the fire weather section below. The High Wind Warning for this morning was allowed to expire at noon as wind speeds have decreased below warning criteria. Wind gusts up to 65 mph are possible across the mountains and foothills throughout the rest of the day. Otherwise, temperatures will be roughly 15 degrees above normal today. On Saturday, winds aloft will turn to due west and will increase in speed ahead of a digging shortwave trough over Idaho and Wyoming. Looking at cross sections, there does not appear to be much of a stable layer/inversion or a strong mean state critical layer. However, there will be strong gradient winds that will develop across the vast majority of our forecast area. With such warm and dry conditions, soundings show a very deep boundary layer which will be able to mix down the stronger winds aloft. Winds in the mountains and foothills will gust up to 70 mph and winds across the I-25 corridor and plains will gust up to 55 mph. Both areas are currently forecast to be just below High Wind Warning criteria but if there is confidence in higher winds than currently forecast, a High Wind Warning may be needed. Temperatures will be well above normal (15-20 degrees) with highs in the low to mid 70s across the plains. For all those who will be recreating outside tomorrow, the winds may make for a poor experience despite the pleasant temperatures. The aforementioned shortwave trough will move into Colorado Saturday night. This will have a surface cold front associated with it that will have an extremely sharp temperature gradient and strong winds behind it. Temperatures may drop 15 degrees in 10 minutes behind this front. The front will also provide forcing for a couple of bands of precipitation to form across the plains. This precipitation may briefly fall as rain before quickly transitioning over to snow for the rest of the event. Of note, the vast majority of ensemble members from all global models have accumulating snow in Denver. With that being said, only a trace to 1" of snow is expected for the Denver metro with minimal impacts to travel conditions. The Palmer Divide may have larger impacts as more snow is expected to fall there. The Palmer Divide is expected to see 1-4" of snow and with strong winds behind the front, some blowing and drifting snow may be possible. Those traveling along I-25 over the Palmer Divide may experience poor travel conditions late Saturday night. As for the mountains, the trough will bring a quick and somewhat intense round of snow Saturday evening through Sunday morning. The strong west-northwest winds will create great orographic flow for the northern mountains of Colorado. 4-10" is expected mainly above 8,500 feet. With winds gusting to 65 mph, whiteout conditions are possible Saturday night and hazardous travel conditions are expected. The snow will come to an end quickly Sunday morning but blowing snow may still linger. The Winter Weather Advisory was extended to 6pm Saturday through Sunday at 9am. The next impact will be high winds Sunday. Gusts could reach 60 mph right behind the cold front late Saturday night across the plains. Then, early Sunday morning through the afternoon, strong northerly 700 mb winds will mix down to the surface, thanks to strong cold air advection, and create high winds across the eastern plains of Colorado. A High Wind Warning was issued for the eastern plains and Palmer Divide from 4am through 6pm for gusts up to 65 mph. There may be blowing dust in areas that do not receive much snow Saturday night. Quieter weather will move in Monday and Tuesday as a ridge aloft moves overhead. Later next week may end up being one of the more significant recording breaking warm weather periods for Colorado. 500 mb temperatures may reach above 591 dm over western Colorado Thursday through Saturday. The ensemble guidance shows the 50th percentile is in the mid 80s for highs in Denver for the weekend of March 21/22. If optimal downslope winds were to occur one of those days, Denver could hit 90 degrees, which some ensemble members do indicate is a real possibility. The earliest 90 in a calendar year for Denver is April 30th. To even come close to that would be very significant. Regardless of getting close to 90 degrees, breaking the all time warmest March high temperature for Denver of 84 seems likely. && .AVIATION /18Z TAFS through 18Z Saturday/... Issued at 158 PM MDT Fri Mar 13 2026 Models keep the strong westerlies going at DIA through the afternoon into the early evening hours. Will go with gusts as high as 35 knots through about 00Z. Models do eventually go to true drainage directions right after 06Z with fairly weak speeds. On Saturday, strong westerlies winds are expected again by about 18Z. There will be no ceiling issues. && .FIRE WEATHER... Issued at 212 PM MDT Fri Mar 13 2026 Many locations across the plains are reaching Red Flag criteria this afternoon. A mountain wave cloud is reducing temperatures slightly which is helping us avoid more severe fire weather conditions but there will be an extended period of critical fire weather conditions through the evening. Another Red Flag Warning is in place for Saturday. The question for Saturday will not be whether it will be critical fire weather conditions or not. The question will be whether there will be extremely critical fire weather conditions or not. Some of the more recent high resolution guidance leaves the door open for extremely critical fire weather conditions for the western I-25 corridor. Some guidance suggests winds could gust up to 80 mph in Boulder and Golden during the afternoon, the warmest and driest part of the day. If there is better confidence in these wind gusts with later forecast updates, it is possible our office could decide to go with a PDS Red Flag Warning for Boulder and Jefferson Counties. However, there is not enough confidence in the strength of the winds to increase the wording. Nonetheless, this will be a high end fire danger event for our forecast area. && .BOU WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 6 PM Saturday to 9 AM MDT Sunday for COZ031-033-034. Red Flag Warning until 8 PM MDT this evening for COZ238>251. Red Flag Warning from 11 AM to 9 PM MDT Saturday for COZ238>251. High Wind Watch from late Saturday night through Sunday afternoon for COZ041-042-044>051. && $$ DISCUSSION...Danielson AVIATION...RPK FIRE WEATHER...Danielson