National Weather Service Forecast Discussion |
Thornton Weather Forecast Today's Forecast Story |
597 FXUS65 KBOU 301126 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 526 AM MDT Tue Jun 30 2026 .KEY MESSAGES... - Critical fire weather conditions will be present in the high country today due to warm, dry and windy conditions. - A couple strong storms possible across far northeastern Colorado late this afternoon/evening. - Mainly dry Wednesday through Friday with elevated to critical fire conditions across much of the area. && .DISCUSSION /Through Monday/... Issued at 224 AM MDT Tue Jun 30 2026 SW flow aloft will continue as a disturbance moves from the Great Basin into Wyoming by tonight. At the sfc, the low level flow will become S/SSE across the plains as a lee trough develops along the I-25 Corridor. Eventually, low level moisture will begin to increase over the plains by late aftn into the evening hours with MLCAPE ranging from 1500-2000 kg over the far nern plains by evening. Overall, will see a chc of high based showers/isold tstms by late aftn over nrn portions of the I-25 corridor which will move northeast. DCAPE values will be in the 1000-1500 range and with decent mid level flow may see brief gusty winds of 50-55 mph with some of the higher based activity. Meanwhile, as this activity moves into better MLCAPE by this evening, may see a few svr storms over the far nern plains. Across the higher terrain, it will remain dry. Highs this aftn over nern CO will be in the upper 80`s to lower 90`s. For Wed thru Fri, the flow aloft will continue from the SW but be weaker. Overall, still don`t see much moisture embedded in the flow so the higher terrain will likely remain dry. Across the plains, a sfc lee trogh will remain over the plains. Although there will be some low level moisture and favorable CAPE, over portions of the plains, there is still a decent cap. Thus any tstm activity will probably be rather isold. Highs across the plains will be in the upper 80`s to mid 90`s each day. Looking ahead to the 4th of July, the flow aloft will become more westerly as a weak system moves across the nrn Rockies. This may allow for a cool front to move across nern CO Fri night into Sat. Depending on how much low level moisture there is behind this front, will determine tstm chances across nern CO during the aftn/evening hours. For now have kept pops in the 20-30% range. Across the higher terrain it looks mainly dry. By Sun, an upper level high will begin to build over the srn Rockies. Some subtropical may begin to move into the area which may lead to a slight chc of storms over the area. && .AVIATION /12Z TAFS through 12Z Wednesday/... Issued at 519 AM MDT Tue Jun 30 2026 Winds were SE/S earlly this morning and will gradually increase in the 15z-16z range with gusts up to 25 mph at APA and DIA. By 18z expect gusty SE/S winds at APA/DIA with gusts from 30 to 35 mph. BJC will have lighter winds. From 21z to 00Z there will be widely scattered high based showers with possibly an isold tstm. With decent mid level flow over the area brief wind gusts up to 50 mph may occur but overall coverage will be limited. By early evening, may see an ENE wind shift at DIA with south winds at APA. BJC will go to more northerly. Between 03z and 05z expect drainage winds to develp. As far as smoke will continue to see hazy skies thru tonight. && .FIRE WEATHER... Issued at 224 AM MDT Tue Jun 30 2026 Critical fire conditions will remain over the higher terrain this afternoon into the early evening hours as gusty southwest winds and low humiditity levels will continue. For Wednesday, the flow aloft will weaken, however, humidity levels will be low across much of the area. Looking at data, it appears areas along and south of I-70 over the higher terrain will still see gusty winds up frm 30-35 mph. In addition, areas over the Palmer Divide may see gusty winds south winds so have issued a Fire Weather Watch for these areas. Eslewhere elevated fire conditions will be in place. Looking ahead to Thursday and Friday, it will remain very warm and dry with low humidity levels both days. However, winds will be lighter. Thus most areas will have elevated fire conditions with critical fire conditions becoming more localized. && .BOU WATCHES/WARNINGS/ADVISORIES... Red Flag Warning from noon today to 9 PM MDT this evening for COZ211>214-216>218. Fire Weather Watch from Wednesday afternoon through Wednesday evening for COZ212-214-216-241. && $$ DISCUSSION...RPK AVIATION...RPK FIRE WEATHER...RPK