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739 FXUS65 KBOU 182334 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 534 PM MDT Fri Jul 18 2025 .KEY MESSAGES... - Active pattern continues into the weekend, with scattered afternoon showers and storms each day, and a few severe storms possible Saturday afternoon/evening. - Higher chances for rain across the Front Range mountains and foothills. - Warmer and drier trend for early next week. - 90s continue for the lower elevations through the week. && .DISCUSSION /Through Friday/... Issued at 224 PM MDT Fri Jul 18 2025 Afternoon convection is currently underway across the higher elevations. Scattered high-based showers and storms will be possible through the evening, with gusty outflows to 40 mph possible across the foothills and plains, and slow moving storms may bring some localized heavy rainfall. Greater instability is expected for the northeastern corner of the state where slightly higher MLCAPE and modest shear would allow an isolated severe threat for large hail and severe gusts, but Colorado is just on the fringes of the greatest instability/moisture/shear line, keeping the threat limited. Cloud cover will help keep temperatures slightly above normal overnight. Southwest flow aloft will be in place Saturday, with increasing moisture expected across the forecast area. PWAT values ranging from 110-150% of normal are expected as an upper-level high over the southeast helps pull Gulf moisture into the region. While there are some slight discrepancies between models on how far west the moisture will make it, dewpoints in the mid 60s are expected on the east side of a dryline, MLCAPE between 2000-2400 J/kg, and 0-6 km bulk shear between 45-50 kts across the northern corner will support supercell development by the afternoon. The SPC has put us in a Slight Risk for severe weather (large hail and damaging winds) from Logan County eastward, with a Marginal west to I-25, which seems reasonable at this time. Depending on how far west the moisture makes it could lead to a few adjustments with the severe risk. The rest of the long term forecast period looks to remain fairly active, with afternoon mountain showers and storms possible each day, with some spilling onto the plains. Temperatures will remain in the 90s across the plains through the week as upper-level ridging over the central US amplifies. Light winds are expected under the ridge and decreasing moisture to start the week will slowly increase by mid-week as monsoonal moisture wraps around the persistent high. && .AVIATION /00Z TAFS through 00Z Sunday/... Issued at 534 PM MDT Fri Jul 18 2025 Scattered showers and storms have once again plagued the TAF sites with VRB winds gusting to around 30 kts. There is some backwash from the first round of storms, but that is being quickly replaced by more VRB winds from the southwest or west as the next batch of scattered showers/isolated storms works east. We think this will be the last round, so winds are expected to settle down post showers in the 02Z-03Z time frame. Then fairly normal diurnal winds expected for the rest of the night through 21Z Saturday. Another round of scattered showers and storms with VRB wind gusts to ~35 kts expected 21Z Saturday - 02Z Sunday. Ceilings are high with only light smoke/haze, and thus VFR conditions will persist through the period. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Bonner AVIATION...Barjenbruch