205 
FXUS65 KBOU 041802
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1202 PM MDT Sun Oct 4 2026

.KEY MESSAGES...

- Dry and unseasonably warm through at least Saturday, with
  record/near record warmth on Monday.

- Isolated showers possible (15-30% chance) most afternoons for
  the higher elevations, highest Tue. Precipitation, if any, will
  be highly localized.
 
&&

.DISCUSSION /Through Sunday/...
Issued at 1200 PM MDT Sun Oct 4 2026

A ridge-dominated pattern will result in an uncharacteristically
warm week through at least Saturday, featuring departures from
normal of up to 15-20 degrees across the lowlands both Monday and
Tuesday. Today, a southerly and easterly low-level post-frontal flow
pattern together with the more western ridge axis placement will 
see us "only" climb into the upper 70's to lower 80's in the 
plains. A modest amount of mid-level moisture trapped beneath the 
ridge may support an isolated shower this afternoon in and around
Park County, but given the lack of forcing, any precipitation 
would be light.

The ridge nudges eastward Monday, with the return of subsident
flow and a light downslope wind component pushing temperatures to
near daily records for many. It's probable (>75% chance) that we 
will register a few 90F+ readings across portions of the urban 
corridor and South Platte River Valley. Once again, a spotty light
afternoon shower can't be ruled out for parts of the high country
with lingering moisture around.

Come Tuesday we'll see a slight relaxation of the ridge, with 
height falls leading to modest cooling aloft and thus marginally 
unstable conditions in the high country. This should allow for a 
minor uptick in afternoon showers over the mountains, and perhaps 
a weak thunderstorm or two. Elsewhere, moisture will be much too 
limited to support any precipitation, although a little more cloud
cover can be expected. With surface winds taking on a more 
upslope component, temperatures look to cool a couple of degrees 
over the plains/urban corridor, but will remain plenty warm.

General flattening of the ridge Wednesday through Saturday may 
allow for a few degrees of additional cooling, however ensembles 
remain locked-in on the continuation of well above normal 
temperatures. It appears we'll hold on to sufficient mid-level 
moisture to support slight chances (10-25%) of an afternoon shower
in the high country essentially each day under a more westerly 
flow pattern.

There is broad agreement among both deterministic and ensemble
guidance in the development of longwave troughing across the 
Intermountain West over the weekend, with a resultant pattern
change for Colorado come Sunday or Monday as said trough pushes
east. Forecast uncertainty skyrockets starting Sunday, with
continued variability in trough amplitude and speed among the
range of available guidance. Cluster analysis using the 10/4 0Z
guidance favors the slower solutions by roughly 2:1. Whatever the
case, run-to-run trends suggest a rising potential for widespread
precipitation in the October 11-13 period, accompanied by a 
notable cooldown. As is typical with these flow patterns, impacts
would be favored earlier for our mountains versus the lower
elevations, so the current forecast does introduce higher PoPs for
the high country beginning Sunday.

&&

.AVIATION /18Z TAFS through 18Z Monday/...
Issued at 1128 AM MDT Sun Oct 4 2026

VFR conditions expected through the TAF period. Light and variable 
winds expected for the next couple of hours, though with a westerly 
component favored. By 20Z, winds should turn northeasterly and stay 
there for a few hours before turning back to the south. KDEN and 
KAPA may see some more gusty southerly winds (~15-20 kts) between 
00Z and 05Z, after which winds should settle into drainage for the 
overnight hours. Another period of light and variable winds is 
expected in the morning, around 16-20Z, with winds settling into a 
northeast pattern again after that. Skies should remain clear 
through the TAF period.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...BRQ
AVIATION...AGS