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066 FXUS65 KBOU 201802 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 1202 PM MDT Thu Aug 20 2026 .KEY MESSAGES... - Warmer and drier conditions expected today, with isolated showers/storms in the mountains. - Slight increase in afternoon showers/storms on Friday, with a few capable of producing gusty outflows. - Monsoon moisture returns this weekend and holds into early next week, with increasing chance of storms. - The urban corridor will continue to see afternoon highs in the 90s through the weekend, with temperatures climbing into the upper 90s on Friday. && .DISCUSSION /Through Wednesday/... Issued at 128 AM MDT Thu Aug 20 2026 Slightly warmer temperatures are expected today as another upper- level ridge builds over the Four Corners. Isolated showers and storms will be possible in the mountains, generally for areas south of I-70. Widespread highs in the 90s are expected across the plains, where mostly clear skies and light winds will prevail. Friday will be slightly warmer, with afternoon high temps expected to warm into the mid to upper 90s along the urban corridor, as the ridge shifts slightly eastward. The current forecast high at KDEN is 97 degrees, which puts us within two degrees of tying the daily record high temperature (99F set in 2023) currently in place. Mid-level moisture looks to wrap around the ridge that will increase enough to see isolated to scattered high-based showers and storms develop along the higher terrain in the afternoon, with potential for a few capable of producing strong to severe gusts if they can manage to make it onto the lower elevations, as forecast soundings show DCAPE values ranging from 1200 to 1600 J/kg. Any precipitation that manages to reach the ground is expected to be very light, with just a few hundredths of an inch at best. By Saturday, ensembles show precipitable water values increase across the forecast area, though the ECMWF is slightly more bullish than the GFS, with values ranging from 140-180% of normal compared to 100-160%, respectively. PWATs are expected to remain elevated through the weekend that will keep decent chances for showers and storms each afternoon, especially for the mountains. A shortwave is expected to move along the northern tier Sunday and Monday that will flatten the ridge for at least a few days, bringing more zonal flow aloft and a few days of slightly cooler temperatures, with daily afternoon shower/storm potential remaining into the start of next week. && .AVIATION /18Z TAFS through 18Z Friday/... Issued at 1159 AM MDT Thu Aug 20 2026 Skies are mostly clear across the region with the exception of a few cumulus clouds over the central mountains of Colorado. The chance for showers in the vicinity of the airports today is near zero. We expect winds over the area to remain northeasterly through most of the afternoon and gradually shift to the southeast around 01Z. For tonight, drainage S/SSW flow will be in place at KDEN and KAPA, and a light WSW (