Westminster, Colorado 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

488
FXUS65 KBOU 292039
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
239 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 /18Z TAFS through 18Z Tuesday/...
Issued at 1225 PM MDT Mon Jun 29 2026

Wind direction will once again be a bit tricky this afternoon. Winds
are currently gusting up to 30KT at KAPA from the southwest. At
KDEN, winds are E-ESE at the moment, and KBJC is experiencing NE
winds. Much like yesterday, there is a circulation situated
between KAPA and KDEN, and there are two possible scenarios. The
first scenario, and the one that high-res models have favored over
the last couple afternoons, is that southwesterly winds aloft mix
down to the surface across the entire Denver metro area. However,
model guidance has a tendency to struggle with cyclone days due
to overmixing. The second scenario would involve a cyclone
continuing to be reinforced over the next few hours, which would
eventually bring winds around counterclockwise to the NE at KDEN
around 21Z. Winds will transition to SSW drainage flow by 06Z, and
start out S-SSE tomorrow morning.

Smoke concentrations from the wildfires in western CO and the
Southwest U.S. have remained relatively low through this morning and
there have not been impacts to slant-range visibility at this time.
However, this could quickly change as plumes evolve and smoke
continues to be advected northeast. Smoke concentrations are
projected to increase around 00Z, as the sun angle lowers,
possibly impacting slant-range visibility through dusk.

&&

.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.

Red Flag Warning until 9 PM MDT this evening for COZ212>214-216.

Red Flag Warning until 7 PM MDT this evening for COZ241-246-247.

&&

$$

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