489
FXUS65 KBOU 300533
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1133 PM MDT Mon Jun 29 2026

.KEY MESSAGES...

- Elevated to critical fire weather conditions will be present in
  the high country through Wednesday due to warm, dry and windy
  conditions.

- Little change in the forecast pattern through the next several
  days. The only exception will be for a chance of thunderstorms
  over the plains on Tuesday.

- A couple strong storms possible across far northeastern Colorado
  Tuesday afternoon/evening.

&&

.DISCUSSION /Through Monday/...
Issued at 151 PM MDT Mon Jun 29 2026

After several consecutive forecast shifts with largely the same
synoptic pattern in place across the region, I`ve just about run
out of adjectives to describe this relentless period of hot/dry,
critical fire weather conditions that have had a grip over much of
the region over the last several days. Unfortunately, there`s
still little reason to believe any significant change is in store
over the next week or so... and critical fire weather conditions
will be the theme of this forecast discussion and the subsequent
Fire Wx section further below.

Water vapor satellite and RAP analysis data shows a strong
shortwave trough lifting into eastern Wyoming this afternoon, with
a very dry airmass over most of Colorado. This is further
confirmed by surface data from across our higher elevations, where
stronger subsidence has mixed out dew points into the single
digits to as low as -12F at Vail Pass. Gusty winds are also a
common sight across the region, associated with the 500mb speed
max that is starting to depart the area. Critical fire weather
conditions are widespread across the higher elevations. Meanwhile,
it`s two distinct stories for the lower elevations. A pronounced
Denver cyclone is spinning pretty close to TDEN/KFTG, with weaker
easterly/northeasterly flow on the north side of this feature.
Gusty southwesterly winds have been observed across the southern
Denver metro, Palmer Divide, and Lincoln county with RH falling as
low to the single digits. We should see a another gradient across
the metro/plains with high temperatures this afternoon in the
mid/upper 80s on the cool side of the boundary, and upper 80s to
mid 90s to the south.

The next shortwave embedded in the southwesterly flow aloft will
track across the region tomorrow. Gradual lee cyclogenesis should
allow southeasterly flow to develop across the plains, leading to
some slow moisture advection/moisture return for most of the lower
elevations. It will take a while for surface dew points to return
to the 40s to 50s meaning that instability will be slow to develop
across the far eastern plains during the day. However, it appears
we`ll destabilize just enough for a few storms to develop with the
passing shortwave. With southwesterly flow aloft, there should be
roughly about 30-45kt of deep layer shear to work with, and I
suppose there`s a chance for a strong storm or two during the
evening hours.

Beyond that, there`s little else new to discuss. West-
southwesterly flow aloft is expected to continue for the next
several days as the broad trough over the western CONUS slowly
weakens and a strong upper high sits across the Ohio Valley and
Mid-Atlantic. A few shortwaves track through the region but
largely look to be dry. Warmer temperatures are likely to end the
week, with mid 90s possible on Friday. Both of these two features
do eventually look like they`ll weaken closer to next weekend,
though the general thought is that ridging will build back over
the region as we approach next week.

&&

.AVIATION /06Z TAFS through 06Z Wednesday/...
Issued at 1125 PM MDT Mon Jun 29 2026

Winds will be SE to S overnight and continue thru 16Z on Tue.
Winds by late morning will increase at APA and DIA with gusts
from 25 to 30 mph after 19z. At BJC will keep winds SE but speeds
will be lighter. By 21Z, there will be widely sct high based
showers. With mid level flow still decent brief gusts from 40 to
50 mph certainly can`t be ruled out.  As far as smoke, will keep
it in the tafs as skies will remain hazy. For Tue evening, winds
may turn more north for a few hours at BJC and DIA before shifting
to drainage in the 03z-05z timeframe.

&&

.FIRE WEATHER...
Issued at 151 PM MDT Mon Jun 29 2026

Critical fire weather conditions remain possible/likely each
afternoon this week, especially over the higher elevations. Dry
subsident flow has led to RH really tanking across the high
country along/south of I-70, where RH has fallen into the single
digits. Deeper mixing along the Palmer Divide and plains has also
allowed gusty winds to develop and mix out the little remaining
surface moisture there. Though fuels were a bit more marginal
there, the combination of ~5% RH and gusts of 35-45 mph earlier
was enough to pull the trigger on a Red Flag Warning for the rest
of the afternoon.

As winds aloft slowly decrease over the next couple of days,
critical fire weather conditions are expected to gradually
contract a bit. Still most of the higher elevations are expected
to see critical fire weather conditions on Tuesday, and again on
both Wednesday and Thursday. There is considerably less confidence
in the wind forecasts by Thursday and Friday as the pattern begins
to (very slowly) break down with winds aloft continuing to weaken.
While it is likely that additional Fire Weather highlights are
needed, it is also likely that these will largely be confined to
the high mountains and mountain valleys where wind gusts can more
easily mix down. It`s also possible that daytime heating is
eventually affected by increasing smoke concentrations aloft could
impact daytime heating and subsequently mixing/wind gust
potential... but this is far too uncertain to introduce to the
official forecast at this time.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from noon to 9 PM MDT Tuesday for COZ211>214-
216>218.

&&

$$

DISCUSSION...Hiris
AVIATION...RPK
FIRE WEATHER...Hiris

NWS BOU Office Area Forecast Discussion