267
FXUS65 KBOU 011833
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1233 PM MDT Sat Aug 1 2026

.KEY MESSAGES...

- Heat returns tomorrow, with temperatures reaching into the
  upper 90s and lower 100s on Sunday and Monday.

- Heat Advisory in effect for the I-25 corridor from Sunday
  through late Monday evening.

- Cooler for Tuesday and Wednesday, but warm and generally dry
  conditions will continue for the next several days.

&&

.DISCUSSION /Through Saturday/...
Issued at 1201 PM MDT Sat Aug 1 2026

Quiet weather and warm conditions are expected this afternoon.
Tomorrow, the thermal ridge will shift east over our area,
increasing 700mb temperatures around 4 to 6 degrees C. This, and
plenty of sunshine, will put surface temps in the mid 90s to
around 104 degrees across the plains Sunday afternoon. A Heat
Advisory will go into effect Sunday at noon for the I-25 corridor
and Weld County.

The temperatures on Monday are a bit trickier. The upper level
thermal ridge could remain over the area on Monday, keeping
temperatures well above normal for most of the area. However,
there is an upper level trough that`s forecast to develop and move
through the northern Great Plains and Canada on Monday. This will
develop a surface low to our north, which will drag a cold front
through our area sometime Monday. Models are trending earlier
with the cold front, now moving it into our northern counties
sometime late Monday morning into Monday afternoon, which could
definitely impact our highs on Monday, especially for our northern
plains counties. The earlier front timing could also impact the
northern extent of the Heat Advisory on Monday as well, but for
now we will leave the Advisory as is until we have higher
confidence in the timing. The NBM currently has a 25th to 75th
percentile spread in max temperatures of around 10 degrees
(mid/upper 80s to upper 90s) for areas along the CO/WY border, due
to that uncertainty with the front timing. High temperatures
south of a Boulder to Yuma line, should be less impacted by the
front given the current frontal timing, so we are more confident
in those highs reaching into the upper 90s to low 100s Monday
afternoon. But we`ll have to keep an eye on that front as we get
closer.

On Tuesday and Wednesday, that upper level high is expected to push
back westward. This combined with the surface front will give us a
brief reprieve from the above normal temperatures. The exact amount
of cooling for Tuesday is still uncertain, with ensemble members
ranging anywhere from the mid 60s to upper 90s. Most likely highs
look to be in the low 80s for the plains on Tuesday. On
Wednesday, temperatures will warm back closer to normal (around 90
degrees). The best chance for precip this week will be
along/behind the front and Tuesday and Wednesday afternoons as the
stronger subsidence moves off to the west and easterly surface
winds allow for some weak upslope. However, our "best chances" are
still only around 20% to 40%, as our moisture struggles to
recover. Temperatures will gradually warm for Thursday and Friday
as the thermal ridge inches closer to the area each afternoon.

&&

.AVIATION /18Z TAFS through 18Z Sunday/...
Issued at 1126 AM MDT Sat Aug 1 2026

VFR conditions are expected throughout the TAF period. Only a few
high clouds are likely today with winds generally east to ESE
throughout the afternoon. Tonight, winds will be southerly and
elevated- around 15 kts with some slightly higher gusts possible-
at KAPA and KDEN. Winds will be light and variable tomorrow
morning before turning to the east once again tomorrow afternoon.
Smoke will be aloft throughout much of this TAF period, but no
slant-wise visibility issues are currently expected.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from noon Sunday to 9 PM MDT Monday for COZ038>043.

&&

$$

DISCUSSION...AP
AVIATION...MV

NWS BOU Office Area Forecast Discussion