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100 FXUS65 KBOU 181114 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 514 AM MDT Thu Jun 18 2026 .KEY MESSAGES... - Elevated fire weather conditions in the mountains and valleys today and Friday with critical conditions expected on Saturday. - Strong to severe storms possible across the eastern plains on Saturday. - Scattered coverage of showers and storms on Sunday and Monday. && .DISCUSSION /Through Wednesday/... Issued at 218 AM MDT Thu Jun 18 2026 Relatively quiet weather expected today as northwest flow aloft decreases as the upper level ridge begins shifting east. With the passage of the cold front, temperatures today should be cooler than yesterday, with the plains reaching up to the mid-upper 80s by the afternoon. Elevated fire weather conditions are possible for the mountains and high valleys. However, due to the expected marginal conditions (winds generally at or under 25 mph) have opted out of any highlights. There could be gusts up to 30-35 mph, particularly across the southern Front Range mountains, but they should be short in duration. Temperatures will begin warming again on Friday, with highs in the upper 80s, and possibly low 90s for portions of the eastern plains. Another round of elevated fire weather conditions is possible for the mountains and North Park. However, with relatively weak flow aloft, winds should remain under 25 mph. For the plains, with some mid-level moisture advecting into the region, there could be an isolated shower/weak thunderstorm, mainly near the Palmer Divide area in the late afternoon. Saturday is looking to be an active day, with increasing fire weather concerns over the mountains and strong-to-severe thunderstorms for the plains. The upper level ridge will flatten due to an incoming shortwave trough. This will allow winds across the high terrain to strengthen, with westerly winds gusting up to 45 mph throughout the afternoon. With the expected low relative humidity values, have issued a Fire Weather Watch for the mountains and high valleys. However, it is important to note that the northern Front Range mountains, Park Range, and North Park may not see RH values down to 15% due to the incoming system advecting moisture into the region. Will be watching closely on the evolution of the shortwave, as an earlier arrival of the system could keep those areas out of fire weather highlights for Saturday. For the plains, temperatures should once again warm up to the 90s by the afternoon. With the arrival of the shortwave, showers and thunderstorms are possible, with strong to severe storms becoming increasingly likely for our eastern plains where a dry line will set up. Modeled Skew-T soundings how MLCAPE up to 3000 J/kg, with decent 0-6 Km bulk shear promoting good updrafts in storms. SPC has portions of our plains in a Marginal (1/5) and Slight (2/5) risk, which seems reasonable at this time. Guidance continues to favor multiple shortwaves passing through towards the beginning of next week. This will provide daily chances of showers and thunderstorms throughout the week, mainly for the foothills and plains. Seasonal temperatures are expected for the first half of the week, with highs in the low-to-mid 80s. && .AVIATION /12Z TAFS through 12Z Friday/... Issued at 502 AM MDT Thu Jun 18 2026 VFR conditions expected through the TAF period. Winds are currently from the south/southeast at DEN and APA (light and VRB at BJC). Expect this to continue for the next few hours before winds strengthen (8-15 kts) with the development of a cyclone. APA should remain southeast to east throughout the day while BJC becomes northeast for the majority of the afternoon and evening. DEN will likely vary from southeast to northeast in the afternoon. As the cyclone evolves, stronger southerly winds (15-20 kts) are expected at DEN and APA sometime between 02Z-04Z. BJC should remain light and transition to more northwesterly flow. && .BOU WATCHES/WARNINGS/ADVISORIES... Fire Weather Watch from Saturday afternoon through Saturday evening for COZ211>214-217-218. && $$ DISCUSSION...MAI AVIATION...MAI