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537 FXUS65 KBOU 051741 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 1141 AM MDT Wed Aug 5 2026 .KEY MESSAGES... - Red Flag Warning today for the northern mountains and high valleys. - Elevated to critical fire weather conditions likely to persist across the high mountain valleys through the weekend. - Slightly warmer today before temperatures gradually warm back to the triple digits by the weekend. && .DISCUSSION /Through Tuesday/... Issued at 210 AM MDT Wed Aug 5 2026 The cold front did not disappoint in bringing some relief from the heat on Tuesday. We will see one more day of sub 90s today before the upper level ridge pushes slightly east, centering itself over the Four Corners and Great Basin for the rest of the week. This all-too-familiar pattern will be responsible for another hot and dry week, with temperatures still expected to gradually warm each day, with the urban corridor reaching the mid to upper 90s by Thursday. The main concern for today will be with increasing northwesterly flow bringing gusty winds to the higher elevations where very low relative humidity will be in place (single digits). A Red Flag Warning is in effect for the northern mountains and high valleys from 12 PM to 7 PM today. Across the lower elevations, early morning fog and low clouds will help keep cooler temperatures (mid to upper 70s) in place across the far eastern plains, with mid to upper 80s expected for the urban corridor. Northerly flow from an early morning surface cyclone is expected to bring some low clouds and potentially some fog into the urban corridor near sunrise. This is expected to clear out through the morning, but this could keep temperatures a few degrees cooler than forecast if it sticks around longer than expected. While smoke will remain across the area today, conditions should improve slightly compared to yesterday before another surge of heavier concentrations arrives by Wednesday morning. Precipitation chances continue to look bleak under the persistent ridge, with dry conditions expected through most of the forecast period. The next opportunity for measurable precipitation arrives Sunday afternoon as PWATs increase to near-normal values over the mountains. Even then, precipitation amounts are expected to remain light, with only a few hundredths possible for the mountains from I-70 southward. && .AVIATION /18Z TAFS through 18Z Thursday/... Issued at 1116 AM MDT Wed Aug 5 2026 Current observations show winds gradually turning north/northeast as the cyclone continues east of the terminals. Typical diurnal wind pattern expected throughout the day with winds transitioning to southeast and then drainage by tonight. With the low stratus clearing in the past hour, no ceiling issues expected for the rest of the day. However, smoke today may cause slant-wise visibility issues this afternoon/evening. Tomorrow morning, low stratus will form again, but will likely stay east of all terminals. However, with dewpoint depressions decreasing we could see haze in the morning. Guidance has continued to indicate smoke concentration increasing by mid-morning, which will likely cause more visibility issues throughout the day. && .FIRE WEATHER... Issued at 210 AM MDT Wed Aug 5 2026 Dry and windy conditions are expected across the mountains and high valleys today, where single digit relative humidity will coincide with 25-35 mph gusts. A Red Flag Warning is in effect for the northern mountains and high valleys from 12 PM to 7 PM today. While winds are expected to slacken a bit on Thursday, very dry conditions are expected to persist through the week, spreading eastward onto the lower elevations by Thursday afternoon. Elevated fire weather conditions are expected to persist across the higher elevations through the week, with localized areas of critical fire weather conditions. Winds are largely expected to remain below critical thresholds across the plains, but single digit to low teens RH is expected each afternoon for the majority of our lower elevations, which will create some limited and localized elevated to critical fire weather conditions each afternoon this week. && .BOU WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 7 PM MDT this evening for COZ211>214-217- 218. && $$ DISCUSSION...9 AVIATION...MAI FIRE WEATHER...9