277
FXUS65 KBOU 211753
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1153 AM MDT Sun Jun 21 2026

.KEY MESSAGES...

- Strong to severe storms possible across the far eastern plains
  today. Otherwise, temperatures holding steady with elevated fire
  weather conditions in the high country and some patchy smoke
  aloft from wildfires in Utah.

- Increasing coverage of afternoon thunderstorms early to mid
  week, with continued potential for severe thunderstorms,
  especially in the plains.

- Slightly moderated temperatures midweek, with drier and warmer
  weather returning for the weekend.

- Elevated to at times locally critical fire weather conditions
  will persist much of the week in the high country.

&&

.DISCUSSION /Through Saturday/...
Issued at 105 AM MDT Sun Jun 21 2026

Stratus has become relatively widespread across the lower
elevations in the wake of yesterday`s front, though should largely
remain elevated enough to keep any dense fog patchy in nature,
more prevalent over the higher elevations of the Pawnee
Grasslands. Cross-sections point to a fairly early mixing of
westerly and southwesterly flow this morning which should help
dissipate lingering stratus shortly after sunrise. Mostly elevated
smoke will also be present at times today, stemming from ongoing
wildfire activity in western Utah.

Today`s convective forecast remains on track, with a modest
dryline progged to settle in our eastern plains and allow for an
axis of greater instability this afternoon/evening across our
easternmost tier of counties. Shear doesn`t appear to be overly
impressive, but a few pockets up to around 40 kts look to be
present in the plains. Wind and hail will be the primary severe
weather threats in the plains today. Farther west, drier air will
be in place through ~500mb under weakly subsident flow, hindering
instability and precipitation chances. Some virga and isolated
showers will be more likely for the urban corridor, along with a
few gusty outflows. Temperatures look to hold steady under the
subsident pattern. In the mountains, lingering breezy and dry
conditions will sustain elevated to near-critical fire weather
conditions.

Another weak shortwave arrives Monday, with the dryline
experiencing a westward nudge and PW values climbing to between
0.80-1.00" for most of the plains. Despite a slight cooldown,
elevated dewpoints will promote increased instability and thus
greater thunderstorm coverage for the lower elevations, including
the I-25 corridor. Still, the higher potential for severe
convection will remain over the rural plains. In the high country,
gusty west winds resulting from strengthening zonal flow will lead
to near-critical and potentially critical fire weather conditions
for some locations.

Moist easterly flow will remain anchored in place Tuesday into
Wednesday, maintaining at least scattered afternoon showers and
thunderstorms for most of the area as well as cooler temperatures
despite some height rises aloft. Precipitation chances for the
urban corridor look to be the highest during this period, and may
extend into Thursday depending on how quickly the pattern evolves.

A warming and drying trend is favored as we head towards the
weekend, with ensemble means indicating healthy potential for
temperatures climbing into the mid/upper 90`s for the lower
elevations by Saturday.

&&

.AVIATION /18Z TAFS through 18Z Monday/...
Issued at 1145 AM MDT Sun Jun 21 2026

Current observations as of 1745z show some stronger W to NW winds
starting to mix down to the surface at KBJC and KDEN with KBJC
recently reporting a 24kt wind gust. Earlier smoke from wildfires
in Utah has become less dense as the morning has progressed.

This afternoon, we expect strong NW to N winds with gusts up to
20-25 kts at all three TAF sites. There is a low chance for some
virga and stronger outflow winds given DCAPE values around 1000
J/kg (mainly for KAPA and KDEN). KAPA has the highest chance of
this, so have now included a prob30 there for this afternoon.

Winds are expected to turn to drainage this evening with even a
brief period of light and vrb winds possible overnight for KAPA
and KBJC. Wildfire smoke could return tomorrow morning between
06z and 12z, potentially impacting slantwise visibility at times,
but currently looks to have minimal near surface impacts. Tomorrow
afternoon should be similar to this afternoon with strong NW
winds gusting to about 20 kts by about 18z to 19z. There will be a
slightly higher chance than this afternoon for showers and
thunderstorms by late afternoon which may need to be included in
future updates.

&&

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

&&

$$

DISCUSSION...BRQ
AVIATION...MV

NWS BOU Office Area Forecast Discussion