870
FXUS65 KBOU 161126
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
526 AM MDT Thu Jul 16 2026

.KEY MESSAGES...

- Hot weather continues through this weekend, peaking again toward
  Sunday. Elevated fire weather conditions across most of the
  area, although we`ll stay shy of any Red Flag criteria.

- Monsoonal moisture is lacking through Saturday with only
  isolated to scattered afternoon/early evening storms in the
  mountains. Dry plains.

- More significant monsoonal moisture and cooler temperatures are
  still on course to arrive early next week, along with a threat
  of locally heavy rainfall.

&&

.DISCUSSION /Through Wednesday/...
Issued at 211 AM MDT Thu Jul 16 2026

Well, it`s been a roughly a week of the same pattern here across
Colorado... but it does look like we`re getting closer to a
notable surge of monsoon moisture across the region.

A broad ridge remains in place across the central CONUS this
morning, and should remain there today before slowly redeveloping
near or north of our CWA by the end of this week. The core of the
mid-level thermal ridge remains just to the north/northwest of the
forecast area, and 700mb temperatures approach 20C the next couple
of days across the high country. That should lead to high
temperatures reaching the mid to upper 80s across the high
mountain valleys the next couple of days, with low to mid 90s
likely across the I-25 corridor.

While water vapor satellite shows a pronounced plume of moisture
stretching across Arizona and Utah, most of Colorado remains on
the edge of the deeper moisture today. Still, there should be
enough moisture along with sufficient daytime heating for some
scattered showers and thunderstorms, mainly over the higher
elevations along and south of I-70. Increasing subsidence as the
ridge builds back over the area will limit coverage of
showers/storms on Friday and Saturday, though a couple stray
showers are still possible both days.

Sunday looks to be the warmest day of the upcoming week as the
ridge remains almost directly overhead, and mid-level temperatures
warm a couple degC as a result. There`s widespread agreement for
upper 90s temperatures to return to the lower elevations, and it
wouldn`t be surprising to see a couple >100F readings across the
I-25 corridor. Some guidance holds onto similar temperatures for
Monday as well.

Sunday into early next week will also be a transition towards a
much more active pattern across Colorado. As the ridge weakens a
bit and slides off to the east, that should allow for the broad
area of monsoonal moisture to finally push into this half of the
state. As the day shift noted in the previous discussion, this
plume of moisture is, well, rather moist. ECMWF ensemble mean
precipitable water... along with 700mb specific humidity values
exceed the 99th percentile (and at times fall outside the model
climatology) across northern Colorado by mid-week next week, with
rather high probabilities of >0.50" of precipitation falling
across the mountains by this time next week. Given weak winds
aloft, locally heavy rainfall is possible (if not likely)
somewhere in our forecast area in this type of setup. Of course,
the heavy rain potential on any given day will be driven by a lot
of mesoscale factors that we simply won`t have a good handle on
for a few more days. We`ll continue to watch the pattern change
closely until then.

&&

.AVIATION /12Z TAFS through 12Z Friday/...
Issued at 525 AM MDT Thu Jul 16 2026

VFR conditions are expected through the TAF period. Drainage winds
should become light and variable for a couple of hours later this
morning, before settling on an easterly direction by the early
afternoon. A period of gustier southeasterly winds is possible
during the evening, before typical drainage flow establishes after
06z tonight.

&&

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

&&

$$

DISCUSSION...Hiris
AVIATION...Hiris

NWS BOU Office Area Forecast Discussion