913
FXUS65 KBOU 260038
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
638 PM MDT Thu Jun 25 2026

.KEY MESSAGES...

- Scattered showers and a few thunderstorms this afternoon and
  evening. A few strong to severe storms still possible later this
  evening across the plains.

- Widespread and prolonged critical fire weather conditions will
  be present in the high country this weekend as warm, dry and
  windy conditions develop.

- All areas will trend warmer and drier this weekend, with little
  change into next week.

&&

.DISCUSSION /Through Thursday/...
Issued at 106 PM MDT Thu Jun 25 2026

Quite the change across the forecast area compared to this time
yesterday. Stratus/stratocumulus remains entrenched across most of
the foothills and plains early this afternoon, with weak upslope
flow still noted across the I-25 corridor. Temperatures are still
in the mid to upper 60s, and are only expected to warm into the
low to mid 70s by later this afternoon. Meanwhile, scattered
showers and a couple weak thunderstorms are ongoing across the
forecast area at this time. The main cluster of showers appears to
be associated with a departing weak shortwave, which is expected
to push out of the CWA within the next couple of hours.

Still, this doesn`t mean the storm potential is completely over
anywhere across the lower elevations. There`s still modest
instability (MLCAPE between 500-1000 J/kg) across portions of the
I-25 corridor and Palmer Divide, with 30-40kt of deep layer shear.
The HRRR is rather insistent on dropping a stronger storm or two
out of Wyoming by about 6-7 PM this evening, which could pose at
least a marginal hail/wind threat... especially if we manage to
clear out and warm into the mid/upper 70s. We`ll see how
convection evolves out of far northern Colorado/souther Wyoming
later this afternoon.

We`ll start to get into a warmer and drier pattern tomorrow as
broad southwesterly flow aloft develops ahead of a large upper
trough dropping into the Pacific Northwest. Another weak shortwave
is expected to move across the forecast area during the day.
Though moisture does begin to decrease, there still should be
sufficient instability for widely scattered showers and
thunderstorms to develop during the afternoon hours. Any stronger
storms would be capable of producing hail and gusty winds, along
with briefly heavy rain.

Moisture will be quick to scour out this weekend as the mid-level
southwesterly flow strengthens and warmer air pushes into the
region. Temperatures will likely return to the 90s across the
plains with above normal temperatures also expected across the
high country. Fire weather will be the main concern this weekend
and is detailed more in the Fire section of this AFD.

While another weak cold front may bring some modest relief to the
region sometime Sunday or Monday, the overall pattern is not
expected to change significantly next week. A broad upper trough
is expected to remain in place over the northwestern CONUS, with a
large ridge anchored across the Ohio Valley. Moisture should
eventually try to work back into the region, but in general the
forecast looks warm and dry as we get into early July.

&&

.AVIATION /00Z TAFS through 00Z Saturday/...
Issued at 637 PM MDT Thu Jun 25 2026

Current radar imagery shows a line of strong to severe storms moving
southeast from Wyoming and entering northern Colorado. It is
becoming increasingly likely that this line of thunderstorms, or
what becomes of it, will at least graze KDEN around 03Z-04Z.
Although it looks like the main thunderstorm threat for this evening
will be associated with the aforementioned line, it is also possible
that the outflow of these thunderstorms could trigger showers or
storms closer to KBJC and KAPA. Therefore, we have decided to extend
the PROB30 until 05Z-06Z for the three airports.

Winds are NE at the moment and it looks like an approaching outflow
boundary will reinforce that direction over the next hour, with
additional variable outflow gusts possible through midnight. MVFR
ceilings are going to be possible after 06Z tonight given the
moisture in place and shower activity expected. There is also a 30%
chance for patchy clouds below 1,000ft AGL, especially close to
sunrise (10Z-12Z), but we have opted to keep a mention of fog or a
SCT008 group out of the TAF for now due to uncertainty regarding
the amount of coverage. It is also worth mentioning that smoke
aloft from the wildfires in Utah may impact slantwise visibility
at times.

Afternoon showers and perhaps isolated thunderstorms seem likely (25-
30% chance) again tomorrow afternoon between 20Z and 01Z. High-res
models show at least high-based showers developing early to mid-
afternoon.

&&

.FIRE WEATHER...
Issued at 106 PM MDT Thu Jun 25 2026

Fire weather conditions will remain subdued today with scattered
showers and a few thunderstorms continuing into the afternoon and
evening hours. Most locations across the forecast area have seen
wetting precipitation, with several areas seeing significant
rainfall over the past 24 hours.

A significant increase in fire danger is expected by this weekend
across the high country, despite the decent wetting rain today
(generally 0.1-0.3" in Middle Park/North Park). Broad
southwesterly flow is expected to develop this weekend, with
sustained speeds likely reaching 20-30 mph with a few gusts up to
50 mph across favored terrain on Saturday, where a Fire Weather
Watch remains in effect.

Little change is expected on Sunday and Monday, though a very weak
cold front could bring marginally better humidity values to the
region. Critical fire weather conditions are likely to continue
across most of the higher elevations. We did consider issuing
additional Fire Weather highlights (or simply extending the time
of the existing watch), but have left the current headlines as is
for now.

Regardless, any new fire starts across the high country, whether
lightning- induced or otherwise, will be susceptible to rapid
spread over the weekend. Users are encouraged to check and follow
the existing city/county fire restrictions across Colorado.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Saturday morning through Saturday
evening for COZ211>214-217-218.

&&

$$

DISCUSSION...Hiris
AVIATION...AA
FIRE WEATHER...Hiris

NWS BOU Office Area Forecast Discussion