981
FXUS65 KBOU 301742
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1142 AM MDT Tue Jun 30 2026

.KEY MESSAGES...

- Critical fire weather conditions will be present in the high
  country today due to warm, dry and windy conditions.

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

- Mainly dry Wednesday through Friday with elevated to critical
  fire conditions across much of the area.

&&

.DISCUSSION /Through Monday/...
Issued at 224 AM MDT Tue Jun 30 2026

SW flow aloft will continue as a disturbance moves from the Great
Basin into Wyoming by tonight.  At the sfc, the low level flow will
become S/SSE across the plains as a lee trough develops along the
I-25 Corridor. Eventually, low level moisture will begin to
increase over the plains by late aftn into the evening hours with
MLCAPE ranging from 1500-2000 kg over the far nern plains by
evening. Overall, will see a chc of high based showers/isold tstms
by late aftn over nrn portions of the I-25 corridor which will
move northeast. DCAPE values will be in the 1000-1500 range and
with decent mid level flow may see brief gusty winds of 50-55 mph
with some of the higher based activity. Meanwhile, as this
activity moves into better MLCAPE by this evening, may see a few
svr storms over the far nern plains. Across the higher terrain,
it will remain dry. Highs this aftn over nern CO will be in the
upper 80`s to lower 90`s.

For Wed thru Fri, the flow aloft will continue from the SW but be
weaker. Overall, still don`t see much moisture embedded in the
flow so the higher terrain will likely remain dry. Across the
plains, a sfc lee trough will remain over the plains. Although
there will be some low level moisture and favorable CAPE, over
portions of the plains, there is still a decent cap. Thus any tstm
activity will probably be rather isold. Highs across the plains
will be in the upper 80`s to mid 90`s each day.

Looking ahead to the 4th of July, the flow aloft will become more
westerly as a weak system moves across the nrn Rockies. This may
allow for a cool front to move across nern CO Fri night into Sat.
Depending on how much low level moisture there is behind this
front, will determine tstm chances across nern CO during the
aftn/evening hours. For now have kept pops in the 20-30% range.
Across the higher terrain it looks mainly dry.

By Sun, an upper level high will begin to build over the srn Rockies.
Some subtropical may begin to move into the area which may lead to a
slight chc of storms over the area.

&&

.AVIATION /18Z TAFS through 18Z Wednesday/...
Issued at 1132 AM MDT Tue Jun 30 2026

Broad southeasterly flow is in place, though we should gradually
see the development of a lee cyclone or some sort of shear zone
across the metro over the next few hours. This shear/convergence
zone may also be the focal point for a few high-based showers
later this afternoon... and an eventual wind shift, whether from
outflow boundaries or from the cyclone, is likely at the terminals
between 21-01z. Until then, gusty southeast winds (at times ~30kt)
are likely to continue.

Forecast confidence decreases this evening, as winds look to
eventually shift to the north or northwest. There should be a
gradual increase in smoke this evening due to fires across
southern/southwestern Colorado, and HRRR smoke guidance would at
least indicate the potential of some slant-range visby issues
through sunset.

Winds will eventually shift to drainage overnight tonight, before
trying to settle back into a easterly component tomorrow. There
may be additional smoke issues again during the 12-17z period
tomorrow but currently not enough confidence to include in the
TAF.

&&

.FIRE WEATHER...
Issued at 224 AM MDT Tue Jun 30 2026

Critical fire conditions will remain over the higher terrain this
afternoon into the early evening hours as gusty southwest winds
and low humidity levels will continue.

For Wednesday, the flow aloft will weaken, however, humidity
levels will be low across much of the area. Looking at data, it
appears areas along and south of I-70 over the higher terrain will
still see gusty winds up frm 30-35 mph. In addition, areas over
the Palmer Divide may see gusty winds south winds so have issued a
Fire Weather Watch for these areas. Elsewhere elevated fire
conditions will be in place.

Looking ahead to Thursday and Friday, it will remain very warm
and dry with low humidity levels both days. However, winds will be
lighter. Thus most areas will have elevated fire conditions with
critical fire conditions becoming more localized.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 9 PM MDT this evening for COZ211>214-
216>218.

Fire Weather Watch from Wednesday afternoon through Wednesday
evening for COZ212-214-216-241.

&&

$$

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

NWS BOU Office Area Forecast Discussion