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766 FXUS65 KBOU 070839 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 239 AM MDT Mon Sep 7 2026 .KEY MESSAGES... - Better chance for showers and thunderstorms this afternoon with locally heavy rain in a few areas across the plains. - Temperatures will remain very warm, with only slight cool down Tuesday and Wednesday. - Chance of afternoon thunderstorms mainly Palmer Divide and east central plains on Tuesday, - Warmer and drier for Thursday and Friday. - Some potential for a brief cooldown next weekend. && .DISCUSSION /Through Sunday/... Issued at 233 AM MDT Mon Sep 7 2026 A upper level trough will move across the nrn Rockies today thru tonight with SW flow aloft across the area. Monsoon moisture will be embedded in the flow with PW values 150 to 175 percent above normal. MLCAPE will be around 1000 j/kg from the Palmer Divide across the far ern plains this aftn with lower values further west. Overall, will see a good chance of showers/tstms this aftn thru the evening hours, especially across the plains. There is enough shear for an isold svr storm or two where the highest MLCAPE will exist this aftn. In addition, with decent PW`s some locally heavy rainfall will be possible as well. Highs this aftn will be in the upper 80`s to mid 90`s across the plains. On Tue, the flow aloft will become more westerly as a wek cool front moves across the plains. There will still be some monsoon moisture embedded in the flow, however, PW values will decrease, especially across the nrn half of the area. Best chc for showers/tstms will be over the Palmer Divide and sern areas of the plains. MLCAPE is fcst to be in the 500-800 j/kg range, however, shear will be better so can`t rule out an isold svr storm over the Palmer Divide. Highs across the plains will be in the 85 to 90 degree range. For Wed, the flow aloft will become more WNW as a surge of cooler air moves across late Tue night into Wed morning. This will lead mainly dry conditions with highs across nern CO in the upper 70`s to mid 80`s. Looking ahead to Thu and Fri, the flow aloft will be mainly zonal with minimal moisture embedded in the flow. As a result, expect mainly dry conditions both days with warmer temperatures as readings over nern CO rise back into the upper 80`s to lower 90s. For next weekend, the flow aloft will remain zonal on Sat as another weak front moves across. As a result, highs will drop back into the 80`s across the plains. Meanwhile, will leave in a slight chc for aftn tstms across the area. On Sun, the flow aloft will become more SW as an upper level trough moves into the nrn Rockies. The GFS is faster with moving a cold front across the area during the day while the ECMWF is slower. With SW flow aloft and upper level trough still to the NW of the area, ECMWF probably has a better handle on timing of front. Thus may see highs reach the upper 80`s to lower 90`s over nern CO on Sun before it reaches the area Sun night. && .AVIATION /06Z TAFS through 06Z Tuesday/... Issued at 1112 PM MDT Sun Sep 6 2026 An outflow boundary from earlier tstms near the foothills has moved across with a wind shift to the W/WSW. These winds should become more SSW/S by 07z at APA/DIA with WNW winds at BJC. On Mon, winds will be light and variable by 13z and then trend to more easterly at BJC and DIA by 17z. At APA, winds will be from the NW by 19z. There will be a chc of showers/tstms by 22z which will linger thru 02z Mon evening. For now have kept a prob30 between 22z and 02z with brief gusty winds up to 35 mph possible. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...RPK AVIATION...RPK