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132 FXUS65 KBOU 101821 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 1221 PM MDT Mon Aug 10 2026 .KEY MESSAGES... - Very warm temperatures to continue through Tuesday, then start to cool Wednesday and fall below normal Thursday. - Another round of high-based virga showers today. Wind gusts of30-45 mph are possible from the showers. - Slight chance for strong to severe thunderstorms over far northeast Colorado late this afternoon and evening. - Monsoon moisture becomes plentiful beginning Wednesday bringing daily rounds of showers and thunderstorms through the rest week and weekend. Locally heavy rainfall and localized flooding are possible. && .DISCUSSION /Through Monday/... Issued at 1217 PM MDT Mon Aug 10 2026 The upper level ridge will continue to dominate the weather today and tomorrow, before a pattern change brings relatively cooler temperatures and increased chances in precipitation chances beginning Wednesday. Today will be similar to what we have been seeing over the weekend, with temperatures in the mid-to-upper 90s and scattered showers and thunderstorms for the mountains and plains. Current satellite imagery shows that cumulus has developed, with virga showers already popping up across mountains and portions of the I-25 corridor. ACARS soundings still show a very dry airmass at the low-levels, so expect most of the showers to produce little to no rainfall for the plains. However, with the increase in moisture, a few of the stronger storms likely will produce light rainfall amounts. SPC mesoanalysis page has DCAPE values ranging from 900-1300 J/kg, so gusty winds of 30-45 mph (a few could be stronger) will be a concern this afternoon/evening. As these storms track east later this afternoon/evening, they will be tapping into a better environment (better low-level moisture, and increased instability) that could support strong to severe storms. CAMs this morning favor storms becoming more linear as they reach the eastern plains, closer to Logan/Washington counties. Outflow gusts of 60-70 mph are possible, with a lower threat for hail. SPC upgraded portions of the eastern plains to a Slight Risk (2/5) for this reason. Tuesday will be similar, with hot temperatures in the mid/upper 90s and high-based showers and thunderstorms in the afternoon. However, instability does not look as favorable, so only expecting outflow gusts up to 35 mph with isolated stronger. We should see a bit more storms having rain reach the ground due continued increase in mid- level moisture. Guidance has this mostly confined to the mountains and high valleys due to better moisture availability. By Wednesday, the upper level ridge will weaken and shift east as a weak shortwave embedded in the flow will traverse the region Wednesday evening/night. Southwest flow aloft will advect monsoonal moisture into the region, where our mountains will receive more widespread showers and thunderstorms. For the plains, scattered showers/thunderstorms will occur, with the possibility of some becoming strong-to-severe, particularly for the eastern plains. Modeled Skew-T soundings show very favorable shear profiles, with decent instability. SPC introduced a Slight Risk (2/5) for this reason, which seems reasonable at this time. Steep low/mid-level lapse rates will support strong outflow winds, however there is also a hail threat. Precipitable water values are expected to get up to 1- 1.3", so any strong storm has the ability to produce localized flooding concerns. Storm motion should be fast, so widespread flooding will not be a concern as of right now. For Thursday, more monsoonal moisture will arrive, with precipitable water values increasing to 120-170% of normal. The upper level shortwave will continue to trek across Colorado Thursday morning, providing lift needed to generate more widespread beneficial rainfall for the plains. Modeled soundings depict a favorable profile for efficient precipitation (above average PWAT, deep warm cloud layer, moist vertical profile) thus there is a higher threat for flooding. WPC has a Slight Risk for excessive rainfall for much of the mountains, I-25 Corridor, and plains for this reason. Friday and into the weekend, ensemble guidance continues to look promising in keeping the upper level ridge out our southeast. This will keep us relatively cool (highs in the 80s) with daily chances of afternoon showers and thunderstorms. && .AVIATION /18Z TAFS through 18Z Tuesday/... Issued at 1142 AM MDT Mon Aug 10 2026 Latest radar scans show some weak showers have started to move off the foothills early this afternoon. So far, no microbursts or significant outflows have been observed. This is expected to change in the next few hours as instability increases and DCAPE values gradually increase as well. While the best timing for gusty outflows/microbursts continues to be from 21Z to 1Z, there is still a nonzero chance for this to occur slightly sooner, and continue through 1Z to 2Z this evening. Strong to severe storms will be possible over the northeastern corner of Colorado this evening that may send some easterly outflows towards the TAF sites which may delay the southward wind transition, but exact timing and location of said storms will heavily determine the wind direction. Due to low confidence in these two things, have not accounted for them in the current TAF, but there could be a few hours of variable winds before the southerly winds take hold for the overnight hours. Smoke has not cleared out nearly as much as anticipated this morning, so FU has been reintroduced to the TAF for the remainder of the day. Guidance continues to show this diminishing but with how much smoke is currently out there, we do expect slant range visibility to be impacted while the heavier concentrations persist. For tomorrow, expecting a fairly normal diurnal wind pattern through the morning, with drainage winds becoming light and variable for a few hours before turning to the NE by around 17Z-18Z before returning to the north due to potential showers passing across Larimer/Weld Counties. A PROB30 has been introduced for potential for gusty outflows from passing showers by 21Z. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...MAI AVIATION...9