720
FXUS65 KBOU 040002
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
602 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 southeasterly 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 /00Z TAFS through 00Z Saturday/...
Issued at 558 PM MDT Thu Sep 3 2026

VFR conditions expected through the TAF period. Winds will stay
east/southeasterly with ~20kt gusts for the next several hours. By
04Z, winds should start turning more southerly, eventually reaching
drainage and staying there overnight and into the early morning.
Around 16Z, winds will turn northerly and then continue in a
clockwise direction, becoming east/southeasterly by 18Z. Some
uncertainty remains with the wind patterns at KAPA. While most
models trend towards a southwest to southeast shift between 15-18Z,
there`s a slight (<30%) chance that winds could follow a more
typical diurnal pattern.

For the afternoon, east/southeast flow should prevail. We expect a
bit more moisture aloft tomorrow, which could allow for some
scattered convection, although confidence remains low for
precipitation (15-30%). If a high-based shower does form over the
airport, gusty outflow winds of 20-30kt are expected. Following
current model guidance, we`ve started the PROB30 at 23Z and extended
it to 03Z Saturday. Once any showers/gusty outflows move out of the
area, winds should turn towards the southwest and stay there
overnight.

&&

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

&&

$$

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