National Weather Service Forecast Discussion |
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071 FXUS65 KBOU 100032 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 632 PM MDT Fri Oct 9 2026 .KEY MESSAGES... - Unseasonably warm through at least Sunday. - Mainly dry weather continues, with only isolated to scatteredshowers (15-30% coverage) and a couple weak storms over themountains through Sunday. Any precipitation would be light. - Elevated fire weather conditions as southwest breezes increase,especially by Saturday. - Pattern change next week, with cooler temperatures finallyarriving by Tuesday. Main precipitation chances hold off untilthe middle of next week, but even then much uncertainty. && .DISCUSSION /Through Friday/... Issued at 125 PM MDT Fri Oct 9 2026 Satellite imagery shows a weak shortwave trough near the Utah/Colorado border. This combined with developing cumulus clouds over the mountains and limited moisture, means isolated high- based showers are still on track for this afternoon and early evening. On Saturday, the ridging that`s been over the region will finally transition southeastward and be centered over the Southern Plains. Southwest flow aloft will prevail behind the ridge and ahead of an upper level trough over the Pacific Northwest. Warm temperatures will continue Saturday. Due to the increasing flow aloft, breezy southwest winds are expected for Saturday. Like the past few days, isolated to scattered high-based showers are expected over the mountains, with light precipitation amounts at most. The upper level trough dives south across the western states Sunday and Monday while remnants from Hurricane Rachel lift north across the Desert Southwest and Great Basin. Widespread rain is expected across the Great Basin and Desert Southwest, even reaching parts of western Colorado. However, models are in good agreement that any precipitation associated with the upper level trough and remnants of Hurricane Rachel will stay well west of the forecast area. The mountains could see isolated to scattered showers Sunday due to increased moisture and instability. Temperatures will stay well above normal Sunday with highs in the upper 70s to mid 80s. Come Monday, the temperature forecast becomes highly uncertain over northeast Colorado. Surface low pressure deepens over southeast Colorado and drags a backdoor cold front into northeast Colorado. The timing of this front will impact Monday`s temperature forecast. The NAM indicates an early arrival for the cold front over the northeast plains with temperatures struggling to reach 60F. Meanwhile, the ECMWF is slower and shows temperatures reaching the mid 80s over the northeast plains. For Tuesday through Friday, precipitation timing and chances remain uncertain due to model differences regarding the placement and track of the ejecting upper level low. Latest trends suggest a slower eastward progression of the trough. Thus, Tuesday is looking drier. Temperatures will be cooler and closer to normal with highs in the mid 60s to lower 70s over northeast Colorado. Given the 12Z GFS and ECMWF, Tuesday night through Wednesday night is on track to be the best time period for precipitation as the upper level low begins to lift across the region.There is still tremendous model uncertainty for Thursday and Friday. Models agree cooler air will remain over the western states with temperatures at or slightly below normal. As far as precipitation chances go, low PoPs in the forecast seem on track given the large amount of uncertainty. && .AVIATION /00Z TAFS through 00Z Sunday/... Issued at 542 PM MDT Fri Oct 9 2026 VFR conditions expected through the TAF period. Expecting to see wind speeds continue to slacken over the next hour, with an easterly progression of the shear zone that has been in place west of KDEN/KAPA in the next hour to bring winds around to the NW. Winds are expected to settle into a SSW flow for the overnight hours at KDEN/KAPA (by 3-5Z), but there could be a brief period of light and variable winds behind the boundary or a gradual counterclockwise turn before they settle in. KBJC is expected to maintain more of a SW to westerly flow for the overnight hours. For Saturday, winds should start to turn to the SW around 19/20Z at KDEN, slightly sooner at KAPA. Forecast soundings show DCAPE approaching 1,000 J/kg in the afternoon that would bring potential for some passing virga showers (gusty winds with no precipitation) beginning around 21Z. A PROB30 has been introduced at KDEN and KBJC from 21Z-24Z to account for some gusty outflows from any virga that could move across the TAF sites, with winds between 20-25 kts possible if they do move overhead. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...BM AVIATION...9