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641 FXUS65 KBOU 052311 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 511 PM MDT Wed Aug 5 2026 .KEY MESSAGES... - Red Flag Warning today for the northern mountains and high valleys. - Elevated and locally critical fire weather conditions likely to persist for the high mountain valleys through the weekend. - Temperatures will gradually warm up this week, with highs back into the upper 90s to around 103 for the plains this weekend. && .DISCUSSION /Through Wednesday/... Issued at 1226 PM MDT Wed Aug 5 2026 Mostly dry conditions are expected for the rest of the afternoon. Temperatures will be warmer than yesterday, but will remain below normal. There is a low chance for a few showers and thunderstorms to develop to the southeast of our forecast area tonight as weak disturbance moves through aloft. An isolated shower or two could make there way far enough northwest to move into Lincoln County, but impacts to our forecast area are not expected. Temperatures will continue to warm tomorrow into the weekend. The upper level high will build north and east over the four corners region, sitting over the area through Sunday. As a result, temperatures will go back above normal, with highs reaching into the mid 90s to around 103 across the plains for the weekend. DENs record high on Saturday will be out of reach, with a current record of 105 set in 1878, but we could go for the record high on Sunday. The current forecast has a high of 99 on Sunday and the current record for August 9th is 98 degrees set in 2021. Along with heat, the upper level ridge will bring northwest mid and upper level winds, which will continuously bring smoke from fires in the Pacific NW into the area aloft through the end of the week. The upper level high does start to shift a bit more to the west Sunday into early next week. Models are hinting at a return of moisture sometime Sunday into the middle of next week. As the high shifts and weakens slightly, moisture could flow from the Pacific into the forecast area aloft, bringing PWs back to near or above normal by early next week. With the weakening of the ridge, a few upper level disturbances will have the potential to move across the area starting on Sunday. The weak lift associated with the disturbances could be enough to trigger a few showers and storms in the higher terrain on Sunday, with rain chances moving east into the plains sometime late Monday into the middle of next week. We`ll also see a gradual cooling trend next week as moisture increases, sky cover increases, and the ridge weakens. && .AVIATION /00Z TAFS through 00Z Friday/... Issued at 504 PM MDT Wed Aug 5 2026 Winds are gradually transitioning to the east and will continue to turn southeast before returning to drainage by 07Z. No ceiling issues expected throughout the TAF period. However, smoke today may cause slant-wise visibility issues through the evening. Similar wind pattern expected tomorrow with no ceiling issues anticipated. However, we will get another push of smoke by 17Z/18Z which will likely put us in ILS conditions. && .BOU WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 7 PM MDT this evening for COZ211>214-217- 218. && $$ DISCUSSION...AP AVIATION...MAI