441
FXUS65 KBOU 161755
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1155 AM MDT Sat Aug 16 2025

.KEY MESSAGES...

- Scattered storms are expected today with strong, gusty outflow
  winds a threat from these storms.

- Near normal temperatures will occur this weekend before
  temperatures slowly climb each day during next work week.

- Drier weather is expected Sunday through most of next week
  although isolated showers and storms may still develop each day.


&&

.DISCUSSION /Through Friday/...
Issued at 203 PM MDT Fri Aug 15 2025

Latest satellite imagery shows moisture wrapping around the
periphery of the ridge centered over the Central CONUS and into
western and central Colorado. This has aided in kicking off diurnal
convection over the high country in areas where the SPC
mesoanalysis shows around 500 J/kg of surface-based CAPE in place.
Temperatures across the plains have climbed into the 90s, but
low-level moisture is sparse and ACARS soundings still show about
100 J/kg of CIN in place to overcome for convection to begin.
Dewpoint depressions are quite large, especially along the urban
corridor and adjacent plains where values between 45F to 55F are
widespread. This will lead to potential for a few things as the
day progresses. First, as storms move off of the higher terrain
and over the capped environment, there is potential for strong
microbursts or outflows to occur as storms begin to collapse as
they move over the lower elevations, causing gusts upwards of 45
to 55 mph to occur. Or, if the cap manages to be overcome, these
storms may persist onto the lower elevations and simply produce
microbursts or gusty outflows as evaporative cooling will be
efficient in this environment, and as seen yesterday, it won`t
take much to get some strong gusts out of passing showers or weak
storms. Shear is limited across the forecast area, and generally
MLCAPE values should remain below 500 J/kg across the plains, with
some greater instability expected for areas along the Wyoming and
Nebraska panhandle (from eastern Weld County to the NE border)
where some higher dewpoints are also in place. The SPC has a
marginal risk in place for these locations where isolated severe
wind gusts or large hail will be possible. Overnight temperatures
will be mild tonight, with upper 50s to mid-60s expected for the
plains and lower foothills, mid 40s for the mountain valleys.

Similar conditions are expected on Saturday with slightly higher
low-level moisture in place that should keep any gusty outflows
or microbursts a little weaker than what we see today.
Temperatures will be a few degrees cooler than today as well, but
still climb into the 90s for the majority of the plains. Shear is
still lacking, so any afternoon convection that forms is expected
to remain sub-severe.

Another warming and drying trend will kick off on Sunday and
continue through the forecast period while Colorado sits
underneath another building ridge. By Wednesday, ensembles show
precipitable water values dropping to around 90% of normal and
700mb temperatures increase to around 17C, making for another hot
and dry week. Fortunately, winds are generally expected to remain
light under the ridge which will help keep any critical fire
weather conditions from developing.

&&

.AVIATION /18Z TAFS through 18Z Sunday/...
Issued at 1127 AM MDT Sat Aug 16 2025

Current light and variable winds should be settling into a
more northeasterly regime for the next few hours at KDEN/KAPA,
slightly more easterly at KBJC. A little more moisture is in
place today and despite some cloudy skies this morning, convection
is still on track to initiate over the higher terrain early this
afternoon bringing potential for some gusty outflows to impact all
TAF sites through the early evening. Gusts between 25 to 35kts
will be possible with storms today. The only question is whether this
morning`s cloudy conditions may push back the timing of expected
impacts by an hour or two, especially at KDEN where ACARS
soundings still show a hefty cap in place late this morning.

Winds are expected to transition to drainage for the overnight
hours tonight and become light and variable for Sunday morning.
Hi-res guidance shows little agreement on what wind directions
will do tomorrow, so have opted to go for a diurnal pattern for
the TAF. Fortunately, winds should remain light (generally under
10kts) through the afternoon tomorrow.

&&

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

&&

$$

DISCUSSION...Bonner
AVIATION...Bonner