National Weather Service Forecast Discussion |
Thornton Weather Forecast Today's Forecast Story |
918 FXUS65 KBOU 150908 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 308 AM MDT Sun Mar 15 2026 .KEY MESSAGES... - Much colder temperatures today with light snow ending over the plains this morning. Gusty winds with areas of blowing dust and elevated fire weather concerns will impact the plains. - In the mountains, snow will taper off this morning but gusty winds will produce some blowing snow over the higher passes. - Save for light mountain snow showers Monday, a steady warming and drying trend will take hold through the week. Fire weather concerns may return to the lower elevations as early as Tuesday. - We`re continuing to monitor the potential for record-breaking March heat by late week. && .UPDATE... Issued at 301 AM MDT Sun Mar 15 2026 Strong cold front has moved across all of the plains early this morning with a band of heavier snow across the Palmer Divide out towards the Limon area. Overall should see a gradually end to snow from north to south by sunrise as much drier air moves in from the north. Mtn areas will still see some light snow thru the day with gusty winds producing some blowing snow over the higher passes. Very windy conditions will continue over the plains this morning, however, latest data suggest the strongest winds will occur thru noon and then decrease this aftn. && .DISCUSSION /Through Saturday/... Issued at 928 PM MDT Sat Mar 14 2026 Our extended period of Chinook winds is coming to an end as a strong cold front, located near Chugwater WY as of 0930 PM MDT, rips south overnight. The front looks to reach the Fort Collins area near 1130 PM, and Denver closer to 1 AM MDT. A sharp temperature drop of around 15 degrees in 30 minutes can be expected, with temperatures falling to around freezing shortly after the frontal passage, and with gusts 35-55 mph impacting all of the lower elevations. Behind it, convective snow showers will produce a short window of snow for most areas along the urban corridor, although with how quickly the bulk of the moisture will move through, accumulations will be quite limited. For the most part, the I-25 corridor stands to see a dusting to an inch, although localized accumulations of 1-3" remain possible generally from Denver south and mainly into the Palmer Divide. More considerable travel impacts are anticipated in our mountains between midnight and sunrise, when a period of locally intense snow squalls will lead to brief 2-3"/hr snowfall rates coinciding with strong winds exceeding 60 mph at times, bringing potential for whiteout conditions for most of the major mountain travel corridors. Snow will have largely tapered off by sunrise Sunday, however occasional light snow may linger through Sunday evening for most areas, with little to no additional accumulation. Sunday will be a cold and blustery day regionwide, with highs only slightly rising above freezing for the warmest locations in the plains and urban corridor. Post-frontal winds from the north will remain steady and rather strong, particularly east of the I-25 corridor, gusting 50-55 mph, and potentially close to 70 mph at times in the vicinity of the I-70 plains corridor. A window of elevated fire weather conditions is likely for the plains in the afternoon as humidity lowers to near 25%, with the locations of concern delineated by those areas that receive little/no snow early this morning (more likely for the rural plains). Sunday night will be the coldest of the week, as lows drop into the teens to low 20`s for the plains and urban corridor respectively, and into the single digits and teens for most mountain communities. Monday will bring warmer temperatures to the region with approximately 15-20 degrees of warming. A few snow showers may continue in the mountains thanks to a secondary surge of mid-level moisture embedded in the northwesterly flow aloft. Only light accumulations are expected for the higher elevations, with limited to no travel impacts. Unfortunately, fire weather concerns look to resurface as early as Tuesday as low-level winds and well-mixed conditions return, under continued warming. Some question as to just how dry we get, and the spatial extent of such conditions, but our northern tier of counties appears most susceptible to locally critical fire. As we`ve been advertising for some time now, highly anomalous upper-level ridging will become increasingly dominant across the southwestern US and Intermountain West late week and into the weekend, leading to temperatures climbing to 20-30 degrees above normal as we enter the weekend. We`re still a ways out to be able to iron out the finer details (exact highs, likelihood of reaching/exceeding monthly records, and exact timing of the peak of the heat), but a prolonged stretch of highs at or above 80F does appear increasingly likely for this time period across much of our lower elevations. && .AVIATION /06Z TAFS through 06Z Monday/... Issued at 1116 PM MDT Sat Mar 14 2026 A stg cold front will move across the area between 06z and 07z with gusty north winds from 40 to 50 mph. There will be a period of light snow between 07z and 11z, however, any accumulation will be very light. Ceilings will drop down to 4000 ft with visibility mainly in the 3-5 mile range with the snow. By 11z, the snow threat shoould end with ceilings between 6000 and 8000 ft. Gusty north winds will continue with a few gusts up to 50 mph. Winds should start to slowly decrease by 18z with gusts from 30-35 mph thru 22z. After 22z winds will become more NE and gradually decrease thru 02z. Ceilings will remain in the 6000-8000 range thru Sun evening. && .BOU WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 9 AM MDT this morning for COZ031- 033-034. High Wind Warning until 3 PM MDT this afternoon for COZ040>051. && $$ UPDATE...RPK DISCUSSION...BRQ AVIATION...RPK