396
FXUS65 KBOU 241125
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
525 AM MDT Mon Aug 24 2026

.KEY MESSAGES...

- Scattered afternoon and evening showers and storms through
  Thursday. A few storms could become severe, particularly for the
  eastern plains.

- Slightly cooler with near normal temperatures for Tuesday and
  Wednesday.

- Gradual drying and hotter temperatures by the end of the week
  and through next weekend.

&&

.DISCUSSION /Through Sunday/...
Issued at 305 AM MDT Mon Aug 24 2026

Current surface observations show breezy winds (30-40 mph) across
the Front Range mountains due to increased flow aloft. Expect breezy
winds to continue throughout the morning, particularly off the
Cheyenne Ridge. With a slight decrease in moisture due to the
west/northwest flow aloft, shower and thunderstorm coverage may be
more limited today. However, CAMs still favor convection
initiating around 1/2 PM across the Front Range mountains, and
tracking east onto the I-25 Corridor and adjacent plains. Model
Skew-T soundings favor the inverted-v profile with DCAPE values
reaching up to 1200- 1400 J/kg. This means any high-based storm
that does develop is capable of producing strong outflow winds.
Most gusts should stay below severe limits (40-55 mph), but can`t
rule out a few 60-65 mph gusts.

In addition, there is a conditional severe weather threat for the
far northeastern plains later in the afternoon/evening. CAMs favor
thunderstorms to develop along a dryline in the wake of a surface
trough. Models continue to disagree where the dryline sets up,
but if it can recede into the far northeastern plains, a few
supercells could impact that area. With better shear/instability
profiles, hail and strong winds will be the main threats.

On Tuesday, a weak cold front will move through the area, which will
bring more seasonable temperatures. Forecasted highs should get up
to the high 80s across the plains. Another round of scattered
showers and thunderstorms expected to develop in the afternoon.
The severe threat does not look that impressive, as overall
instability looks limited compared to farther east in Nebraska and
Kansas. However, these high-based storms still could produce
strong outflow winds, as DCAPE values should get up to 1200-1300
J/kg.

The "cooler" temperatures should last through Wednesday, with highs
reaching up to the mid-to-high 80s across the plains. Afternoon
showers and thunderstorms expected again for the high terrain and
plains. Modeled soundings show more favorable shear profiles, which
would support a few strong/severe storms for the I-25 Corridor and
adjacent plains.

For the later half of the week, ensemble guidance favors heat
rebuilding over the area, with temperatures reaching back up the mid-
90s by Friday and Saturday. The upper level ridge shoddily slide
back west, which will start cutting off our moisture coming into
the region. However, there should still be enough moisture to
support isolated-to-scattered afternoon thunderstorms. By the end
of the weekend, guidance does hint at the upper level ridge
weakening and shifting east due to a shortwave trough entering
the Pacific northwest. With west/southwest flow aloft, moisture
should begin filtering in again, with increase in shower and
thunderstorm activity towards the beginning of next week.

&&

.AVIATION /12Z TAFS through 12Z Tuesday/...
Issued at 518 AM MDT Mon Aug 24 2026

VFR conditions expected through the TAF period. Winds are
currently from drainage to a light westerly flow (VRB at APA).
These light winds, generally under 8-10 kts, will gradually turn
to the northeast by the early afternoon. CAMs are still in
agreement of convection initiating off the high terrain by around
19Z before spilling onto the plains, affecting BJC by 20Z and
DEN/APA by 21Z. Gusty outflows of 30-40 kts is possible with any
storm that develops. There is still hints of showers lingering in
the evening hours (between 00Z and 03Z) so have kept the PROB30 in
the TAF.

There is some uncertainty with wind direction behind the storms
this evening. For now, chose what most guidance had (southwest) to
account for outflow winds from any outflow from the west, with
drainage taking over after. However, winds could be from the
southeast instead. Overnight, there could be low clouds affecting
DEN, between 09Z and 16Z. However, due to low confidence and lack
of model agreement, have kept it out of the TAF for now.

&&

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

&&

$$

DISCUSSION...MAI
AVIATION...MAI

NWS BOU Office Area Forecast Discussion