034
FXUS65 KBOU 280818
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
218 AM MDT Fri Aug 28 2026

.KEY MESSAGES...

- Isolated/scattered high based showers/storms Friday with gusty
  winds.

- Temperatures return to the 90s Friday and Saturday across the
  plains.

- Thunderstorm coverage increases for late Saturday through
  Monday.

&&

.DISCUSSION /Through Thursday/...
Issued at 137 AM MDT Fri Aug 28 2026

An upper level ridge remains centered near the Arizona/New Mexico
border early this morning, leaving most of Colorado in weak
wester/northwesterly flow aloft. This ridge is expected to slowly
shift eastward over the next several days with few other synoptic
scale features of note.

The plume of better monsoon moisture will remain well off to the
west and northwest today. Modest mid-level moisture combined with
deep mixing will lead to widely scattered showers and
thunderstorms this afternoon, though most of the convection should
be weak given only meager instability. Most forecast soundings
show inverted-V profiles across most of the I-25 corridor, and
gusty outflow winds will be the main hazard this afternoon and
evening. Meanwhile, it`ll be another hot day today as 700mb
temperatures climb back to 16-18C. High temperatures should reach
the low to mid 90s across most of the lower elevations.

Saturday features more of the same, with the flow aloft backing to
the west-southwest. Models generally try to increase moisture
aloft a bit, with precipitable water values settling near an inch
across most of the I-25 corridor, with more anomalous PW across
northern/northwestern Colorado. Guidance generally tries to
develop a more organized band of showers and thunderstorms close
to the Wyoming border, associated with a weak mid-level shortwave
and cold front. The ECMWF remains a bit more bullish with this
potential compared to the rest of tonight`s guidance, though even
the more aggressive solutions don`t have much in the way of
rainfall outside of the northern mountains/North Park.

Moisture increases a little bit more on Sunday, with another weak
shortwave racing through the southwesterly flow aloft. Surface
moisture will remain a limiting factor with dew points in the 40s
leading to meager CAPE values across most of the forecast area.
Another, perhaps better defined shortwave moves through on Monday
and will likely provide our best chance of rainfall, though sfc
moisture/instability will again be a bit of a question mark.

By mid-week, most of the remaining moisture aloft sinks off to the
south, meaning that near/above normal temperatures and generally
dry conditions are forecast through the rest of the period.

&&

.AVIATION /06Z TAFS through 06Z Saturday/...
Issued at 1137 PM MDT Thu Aug 27 2026

VFR conditions are expected through the TAF period. Drainage winds
are established at DEN/APA and should continue through the
overnight hours.

A little more uncertainty with both the prevailing winds and
convective potential for Friday. Statistical guidance follows a
typical diurnal pattern, with a gradual clockwise turn to the
winds during the morning hours before settling on a light
north/northeast by the early afternoon. Scattered high-based
showers will likely complicate this a bit, with inverted-V
soundings favoring gusty high-based convection during most of the
afternoon and evening. Have kept the PROB30 with only a few minor
adjustments at this point.

Once convection diminishes during the evening, we should see a
quick return to drainage flow for Friday night into Saturday.

&&

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

&&

$$

DISCUSSION...Hiris
AVIATION...Hiris