157
FXUS65 KBOU 311118
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
518 AM MDT Mon Aug 31 2026

.KEY MESSAGES...

- Better precipitation chances today, with another round of
  afternoon/evening showers and storms, a few may become severe
  over the plains.

- Warmer and drier conditions expected from Tuesday through
  Friday.


&&

.DISCUSSION /Through Sunday/...
Issued at 215 AM MDT Mon Aug 31 2026

SW flow aloft will continue today thru tonight.  Water vapor
imagery shows one disturbance over nrn CO tonight which will move
away from the area this morning. Meanwhile, a secondary
disturbance embedded in the flow will move from nern AZ across wrn
CO late this aftn/early evening and into WY by late
evening/overnight. There will continue to be an influx of monsoon
moisture across the area with PW values up to 150% above normal.
Thus will see showers/tstms become likely by mid to late aftn over
the higher terrain. Across the plains, MLCAPE will be around 1000
j/kg with bulk shear up to 30 kts. Overall, there will be some
threat of wet microbursts from the stronger storms along with
marginal large hail. Best timing of tstms will be from late aftn
thru the mid evening hours. Storms will produce locally heavy rain
in some areas but they will be moving along as flow aloft
increases this evening. As for highs, readings will be near
seasonal normals.

On Tue, there will be a lingering chc of showers across the area in
the morning hours.  By aftn, drier air in SW flow aloft will move
into the area which will lead to lower chances for showers/tstms.
Highs will remain near seasonal normals.

For Wed and Thu, dry air in SW flow aloft will remain over the area
with only a low chc for aftn showers/tstms.  Temperatures will be
warmer as readings rise into the upper 80`s to lower 90s across the
plains.

By Fri thru next weekend, an upper level high build over the central
US as an upper level low resides over the Pacific NW.  This will
allow for the flow aloft to become more SSW.  Models eventually want
to advect some monsoon moisture, from the swrn US, into the higher
terrain by the weekend.  If that happens then there would be an
increasing chc for showers/tstms, mainly over the higher terrain.
Across the plains, expect above normal temps to continue with just a
slight chc of tstms next weekend.

&&

.AVIATION /12Z TAFS through 12Z Tuesday/...
Issued at 513 AM MDT Mon Aug 31 2026

Winds were S to SSW early this morning except at BJC which was
light and variable.  Winds at all three sites should trend to
light and variable in the 14z-15z time period.  By early aftn
winds will become easterly. Showers and tstms will develop after
21z and will linger thru early this evening. Brief gusty winds
from 35 to 45 mph will be possible.

After 01z still will have lingering showers and possibly a tstm
thru 05z with brief wind gusts from 25 to 35 mph.  After 05z
there will still be some widely sct -shra possible thru 09z so
have kept in a prob30. Winds by 01z will be NW and then transition
to S/SSW by 05z.

&&

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

&&

$$

DISCUSSION...RPK
AVIATION...RPK