Area Forecast Discussion
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
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608 FXUS65 KBOU 212325 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 525 PM MDT Wed Oct 21 2026 .KEY MESSAGES... - Warm and dry conditions continue across the lower elevations for the next few days, with scattered light rain and snow showers across the higher elevations. - Cooler, more unsettled weather returns this weekend across the forecast area. - At least a brief warm-up likely sometime early next week. && .DISCUSSION /Through Wednesday/... Issued at 131 PM MDT Wed Oct 21 2026 The upper level ridging over the area is moving east away from the area today as an upper level trough begins to move onto the West Coast. The upper trough will slowly progress eastward towards the area through Friday. On Friday, models are showing a piece of the trough breaking off and developing an upper low over the Desert Southwest, while the parent trough moves off to our northeast. This upper low is then expected to move towards our area through the weekend. This means that we`ll stay in south/southwest flow aloft through the end of the week, bringing moisture into the area. Models are showing PW values around 200% to 350% of normal for much of the area by Thursday. Southwest winds tend to favor precipitation in SW Colorado, versus our forecast area, but we could still see some weaker orographic lift with this setup. With the influx of moisture we are expecting precip chances to increase this evening in the higher terrain, with showers continuing on and off through early Friday. Temperatures will be well above normal through Friday, putting snow levels around 12,000 to 13,500ft. So, most of the activity over the next couple of days will likely be rain, with some snow showers for our highest elevations. The better precip chances will remain in the mountains, but CAMs are trying to bring some showers onto the plains. There is potential for a Denver cyclone tomorrow afternoon, which could allow for weak surface convergence. This, along with the potential for a weak upper disturbance, could be enough with the moisture present for a few showers and storms in the plains Thursday afternoon and evening. On Friday, 700mb to 500mb winds increase over the area. Mostly clear skies and some QG subsidence could allow for these stronger winds to mix towards the surface Friday afternoon. Winds gusts around 30 to 40mph are forecast along and south of I-76 and east of downtown. A strong cold front will move into the CWA late Friday into Saturday. The front will drop temperatures behind it, leaving near to below normal highs for the weekend and early next week. The secondary upper level trough is forecast to approach the area Saturday and Sunday, moving over the area on Monday. Convergence along the front and upper level support from the approaching trough will bring higher rain chances for the plains this weekend. Right now, the highest chance for heavier rainfall amounts is in our southeastern counties, where moisture/PWs will likely be higher. Precip chances will decrease on Monday, with drier conditions expected for the start of next week. Monday will mark the start of a gradual warming trend, although there is potential for a front on Wednesday to bring temperature back down a few degrees. && .AVIATION /00Z TAFS through 00Z Friday/... Issued at 520 PM MDT Wed Oct 21 2026 VFR conditions are expected to prevail for all terminals through the TAF period, although temporary CIGS with bases 070-080 will be possible (30-50% chance) starting near 21Z Thu as mid-level moisture and high-based SHRA move into the area. T-storm potential appears lower (though nonzero - about 20%), so have limited to mention of showers in TAFs at this time. As for winds, KDEN and KAPA will eventually shift to a more southerly direction near 03Z this evening. Latest guidance is now as optimistic about a notable reduction in speeds with this shift, so latest TAF package retains gusts 12-15 kts for those terminals through most of the overnight period. However, it does appear increasingly likely that these will weaken earlier than previously advertised Thu AM (~11-13Z), with a more southwesterly shift and speeds falling well below 10 kts. This will be transient, with breezier southerly flow anticipated to return later in the afternoon. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...AP AVIATION...BRQ