826
FXUS65 KBOU 221850
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1250 PM MDT Sat Aug 22 2026

- Highest coverage of showers and storms expected today, along
  with a few severe storms and locally heavy rainfall this
  afternoon and evening.

- Scattered afternoon and evening showers and storms through
  Thursday. A risk of a couple severe storms each day.

- Temperatures settling back closer to (but still above) normal
  for Tuesday and Wednesday.

- Gradual drying end of next week, with a trend to more summer
  heat through next weekend.

&&

.DISCUSSION /Through Saturday/...
Issued at 1249 PM MDT Sat Aug 22 2026

Satellite and radar shows pretty healthy convection developing
across the Front Range Mountains and Foothills, while the airmass
is still somewhat stable (per ACARS and SPC analysis) but
increasingly moist over the plains. The increased moisture on the
plains is being reinforced by a couple westerly moving surges,
and dewpoints have held in the upper 50s and lower 60s east and
north of Denver. The latest surge coming back through Elbert
County will likely boost values over the Palmer Divide this
afternoon, especially as we develop a surface cyclone in vicinity
of Douglas or western Elbert County. That will aid moisture
convergence and potential for convective initiation there, along
with a risk of a landspout. Otherwise, stronger storms today will
be capable of hail and strong winds, along with locally heavy
rainfall as precipitable water (PW) values climb to 150-170% of
normal and low level moisture remains abundant over the plains. As
per typical, we still think the highest threat of strongest
storms would be along/east of the convergence zone associated with
the developing cyclone and points northward along/just east of
I-25 - essentially covering all of the plains. A couple severe
storms are likely due to MLCAPE increasing to 1200-2000 J/kg. Bulk
shear is weak and less than 25-30 kts, however, so majority of
the severe storms would tend to be pulse (brief). Storm motion
will be rather slow at 15 mph or less given lack of flow aloft,
which will lead to at least some minor flooding threats in a few
spots. Overall progression will eventually be to the east across
the plains into late evening, with potential for a generally
weaker subsequent batch or two of storms behind the initial
stronger ones that would have access to more instability.

We still expect some gradual clearing overnight, but patchy
stratus/fog possible across the plains given the very moist
airmass.

On Sunday, there is some drying noted as flow aloft turns a bit
more westerly. However, we`re not convinced we`ll erode all the
low level moisture across the plains. Even in the mountains we`ll
still see enough to spark scattered thunderstorms, and then those
storms will likely intensify as they move onto the plains as they
encounter a richer, more unstable airmass. Bulk shear profiles are
still marginal, but a couple severe storms will be possible given
sufficient MLCAPE of 1000-1800 J/kg. Similar weather conditions
will likely persist into Monday with little change in the overall
pattern, moisture, and instability profiles. Temperatures will be
rather warm yet, with highs in the 90-95 degree range over the
I-25 Corridor and plains.

There is better agreement of a weak backdoor cool front or two for
Tuesday and Wednesday, offering up a few degrees of cooling and
potentially more active weather over the Front Range and plains.

Thursday and Friday are shaping up to be transition days into a
drier and warmer environment with progressively less storm
coverage, especially by Friday.

Ensembles are consistent showing a return of summer heat for next
weekend, with highs pushing into the mid 90s (30% chance of upper
90s) for the I-25 Corridor and plains as a stronger zonal flow
aloft develops. That would also lead to increasing fire danger as
we begin our journey toward autumn breezes. Unfortunately,
temperatures will feel more like mid summer and humidities will
drop in the drier westerly flow.

&&

.AVIATION /18Z TAFS through 18Z Sunday/...
Issued at 1131 AM MDT Sat Aug 22 2026

A boundary currently to the east of DEN and APA will continue to
move westward towards each of those terminals. It now appears
likely the boundary will get close enough to both of those
terminals to bring stronger easterly winds than previously
forecast. East winds could gust to around 20 knots. There is a
slight chance (20%), however, that a DCVZ develops just to the
east of DEN and APA that keeps winds more out of the northeast
with lighter speeds.

Storms are expected to develop this afternoon with the earliest
possible storms at 19Z at BJC and 20Z at DEN and APA. The most
likely time for storms to impact all terminals is between 22-02Z.
Strong outflow winds are likely with gusts 40-45 knots. It is even
possible (20%) that severe gusts above 50 knots occur at DEN or
APA. Besides winds, there is a chance (40%) that visibility will
be reduced to 2-4 miles and ceilings drop to 4,000-6,000 feet if a
storm were to move directly overhead.

In the evening, southerly winds are likely to develop at DEN and
APA with a small chance rain showers move overhead with little
impact. Drainage winds are expected for much of the night at all
terminals.

Normal wind patterns are expected throughout the day on Sunday.
There will be less low level moisture in place and coverage of
showers and storms will be lower as a result. However, an outflow
boundary or two is still expected to impact the terminals late
tomorrow afternoon and early evening.

&&

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

&&

$$

DISCUSSION...20
AVIATION...Danielson

NWS BOU Office Area Forecast Discussion