FXUS65 KBOU 161135 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 535 AM MDT Sat Aug 16 2025 .KEY MESSAGES... - Scattered storms are expected today with strong, gusty outflow winds a threat from these storms. - Near normal temperatures will occur this weekend before temperatures slowly climb each day during next work week. - Drier weather is expected Sunday through most of next week although isolated showers and storms may still develop each day. && .DISCUSSION /Through Friday/... Issued at 203 PM MDT Fri Aug 15 2025 Latest satellite imagery shows moisture wrapping around the periphery of the ridge centered over the Central CONUS and into western and central Colorado. This has aided in kicking off diurnal convection over the high country in areas where the SPC mesoanalysis shows around 500 J/kg of surface-based CAPE in place. Temperatures across the plains have climbed into the 90s, but low-level moisture is sparse and ACARS soundings still show about 100 J/kg of CIN in place to overcome for convection to begin. Dewpoint depressions are quite large, especially along the urban corridor and adjacent plains where values between 45F to 55F are widespread. This will lead to potential for a few things as the day progresses. First, as storms move off of the higher terrain and over the capped environment, there is potential for strong microbursts or outflows to occur as storms begin to collapse as they move over the lower elevations, causing gusts upwards of 45 to 55 mph to occur. Or, if the cap manages to be overcome, these storms may persist onto the lower elevations and simply produce microbursts or gusty outflows as evaporative cooling will be efficient in this environment, and as seen yesterday, it won't take much to get some strong gusts out of passing showers or weak storms. Shear is limited across the forecast area, and generally MLCAPE values should remain below 500 J/kg across the plains, with some greater instability expected for areas along the Wyoming and Nebraska panhandle (from eastern Weld County to the NE border) where some higher dewpoints are also in place. The SPC has a marginal risk in place for these locations where isolated severe wind gusts or large hail will be possible. Overnight temperatures will be mild tonight, with upper 50s to mid-60s expected for the plains and lower foothills, mid 40s for the mountain valleys. Similar conditions are expected on Saturday with slightly higher low-level moisture in place that should keep any gusty outflows or microbursts a little weaker than what we see today. Temperatures will be a few degrees cooler than today as well, but still climb into the 90s for the majority of the plains. Shear is still lacking, so any afternoon convection that forms is expected to remain sub-severe. Another warming and drying trend will kick off on Sunday and continue through the forecast period while Colorado sits underneath another building ridge. By Wednesday, ensembles show precipitable water values dropping to around 90% of normal and 700mb temperatures increase to around 17C, making for another hot and dry week. Fortunately, winds are generally expected to remain light under the ridge which will help keep any critical fire weather conditions from developing. && .AVIATION /12Z TAFS through 12Z Sunday/... Issued at 522 AM MDT Sat Aug 16 2025 The main concern will once again be afternoon thunderstorms that will produce strong wind gusts. It is likely that all terminals will be impacted by gusty outflow winds so a TEMPO was included at each site. Wind gusts could reach 35 knots at all terminals. The convection will be slightly earlier than normal today with a 19Z start time at BJC and 20Z start time at DEN and APA. Winds will likely stay more northwesterly during the evening before they return to drainage overnight. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Bonner AVIATION...Danielson