National Weather Service Forecast Discussion |
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945 FXUS65 KBOU 040617 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 1217 AM MDT Sun Oct 4 2026 .KEY MESSAGES... - Dry and unseasonably warm weather for the week ahead. Record/near record warmth on Monday. - A few showers possible Tuesday as a weak disturbance moves across. && .DISCUSSION /Through Saturday/... Issued at 1049 PM MDT Sat Oct 3 2026 An upper level high will be centered over the Great Basin on Sun and then will weaken some on Mon. Cross-sections show just enough mid level moisture with favorable lapse rates to allow for isold high based showers mainly over Park county Sun aftn. Otherwise it will be dry with above normal temperatures. On Mon, once again there is some mid level moisture embedded in weak NW flow aloft. As a result, can`t rule out isold high based showers over the high terrain. Meanwhile, with rising 850-700 mb temps along with downslope low level flow, highs will be near record highs across portions of the plains as readings reach the mid 80`s to around 90. On Tue, a weak disturbance may affect the area with some increase in mid level moisture. Thus may see a slightly better chc of high based showers/isold tstms over the higher in the aftn. Over nern CO, it will remain dry with highs remaining 10 to 15 degrees above normal. By Wed, the flow aloft will remain weak WNW. The ECMWF still shows some lingering mid level moisture over the higher terrain while the GFS doesn`t. Overall, any high based shower activity should be rather isold. Once again highs will be 10 to 15 degrees above normal. For Thu and Fri, the flow aloft will become more zonal by Fri with mainly dry conditions expected. Highs both days will continue 10 to 15 degrees above normal over much of the area. By next Sat, the flow aloft will increase from the WSW as an upper level trough develops over the Pacific NW. Meanwhile, there are significant disagreements between the ECMWF and GFS as to where this system will be by late Sun. The ECMWF intensifies the upper level trough and keeps it near the West Coast while the GFS moves it quickly into the nrn Rockies and Great Basin. At this point, really hard to say which solution will pan out. However, it looks warm and dry on Sat with highs from 10 to 15 degrees above normal. For Sun, there could be a chc of precip in the mtns late in the day based on the faster GFS solution. Meanwhile, will likely see another day of above normal temperatures as well. && .AVIATION /06Z TAFS through 06Z Monday/... Issued at 1134 PM MDT Sat Oct 3 2026 Weak upslope flow has allowed for a broken to overcast deck of 6,000 to 7,000 foot AGL clouds to develop over the foothills and spread into the TAF sites. Winds are gradually becoming more southerly and with that, expecting these to become less pronounced over the next few hours, with KBJC likely holding onto them the longest, as winds there are expected to hold onto a more southeasterly component slightly longer than KDEN/KAPA. For the rest of tonight, winds should settle into a south- southeasterly flow and remain under 10 kts before we see speeds start to gradually strengthen between 10Z-12Z. By 14Z to 15Z, KDEN and KAPA will have potential for some 20-25 kt gusts for a few hours, before speeds start to slacken around 17Z to 18Z. There is potential for KDEN to see a few hours of northeasterly winds (