749
FXUS65 KBOU 031942
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
142 PM MDT Thu Sep 3 2026

.KEY MESSAGES...

- Warm and mainly dry conditions through Saturday, with isolated
  afternoon showers/storms favoring the high country.

- Increasing moisture Sunday/Monday with a rise in shower/storm
  coverage, including for the lower elevations.

- Warm temperatures favored to continue next week, with at least
  isolated to scattered showers and storms most afternoons.

&&

.DISCUSSION /Through Thursday/...
Issued at 138 PM MDT Thu Sep 3 2026

Notably drier conditions are in place across the region today,
leading to a break in our recent pattern of afternoon and evening
convection. ACARS soundings from KDEN depict the moisture-starved
profile well, and although a minority of CAMs insist on producing a
few weak high-based showers this evening, this seems rather unlikely
with water vapor imagery showing a pronounced dry slot over southern
Colorado progressing slowly northward. Even if mid-level moisture is
sufficient, high bases and dry near-surface conditions should
restrict any such activity to virga.

Changes into Friday will be subtle. Around 0.5C of warming at 700mb,
along with a less defined Denver cyclone signature and mostly sunny
conditions through mid afternoon will allow for a few degrees of
warming, pushing highs into the mid 90`s for the lower elevations. A
minor southerly shift in flow aloft will be enough to draw up some
modest moisture, with precipitation chances creeping back into the
forecast. These will generally be confined to the high country,
particularly along and south of I-70 where southerly flow is most
orographically favorable, though a few late afternoon showers could
drift into the adjacent plains while weakening. There won`t be much
forcing to sustain activity for very long.

The southerly moisture stream will continue into Saturday as we
remain on the western periphery of a slowly expanding ridge to our
east, resulting in largely isolated high-based showers and a little
better coverage in the mountains. Come Sunday the ridge looks to
flatten slightly, with a corresponding turn to southesterly flow
aloft, helping to work in just enough low-level moisture to allow
for moderately unstable conditions and a return to more scattered
afternoon and evening showers and thunderstorms both Sunday and
Monday, including for the plains and urban corridor. There will be
little effect on temperatures however, with low pressure remaining
well to our northwest and subsident flow east of the Front Range
keeping temperatures 5-10 degrees above normal for the date.

Past Monday, there`s increased variability in ensemble members and
thus more uncertainty in the forecast, although the overall picture
doesn`t appear drastically different to the near term. Broadly, high
pressure looks to prevail over the central US plains, with troughing
to our west maintaining some form of SW to W flow aloft. Above
average temperatures remain favored to persist through much of the
week independent of the exact strength/placement of the ridge, and
the flow pattern would support at least isolated to scattered
shower/storm coverage most days for the plains and mountains
respectively, albeit with uncertainty as far as which days would
bring the higher coverage.

&&

.AVIATION /18Z TAFS through 18Z Friday/...
Issued at 1217 PM MDT Thu Sep 3 2026

VFR conditions are expected through the TAF period. Winds are
becoming more light and variable, and will stay that way for the
next couple hours. By around 21Z, an easterly wind regime will
settle over the area, and winds should remain east/southeast for
much of the afternoon and evening, with some gustiness (15-20kt).
Once the sun goes down, we expect winds to start turning southerly,
reaching drainage by about 07Z. An easterly pattern is expected
again tomorrow morning and afternoon, with winds becoming
northeasterly around 18Z and southeasterly by 21Z.

Currently, CAMs suggest convection tomorrow starting around 22/23Z.
While convective conditions tomorrow look to be better than today,
confidence is still low (10-15%) on any precipitation. High-based
showers with the potential for gusty winds (20-30kt) would be the
main concern, so we`ve added in a Prob30 for 22-24Z. There`s some
uncertainty on the exact timing, but following current model
guidance, it looks like any convection tomorrow would be a late
evening event (23Z-02Z), so we expect to continue the Prob30 in the
00Z TAF.

&&

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

&&

$$

DISCUSSION...BRQ
AVIATION...AGS/MAI