685
FXUS65 KBOU 251909
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
109 PM MDT Sat Jul 25 2026

.KEY MESSAGES...

- Record or near record heat this weekend

- Heat Advisory for the I-25 Corridor today, expanding to all of
  the plains for Sunday as heat builds

- Scattered afternoon/evening thunderstorms this weekend,
  mostnumerous over the higher terrain

- Increasing chances for thunderstorms with locally heavy rain
  Monday, Tuesday, and Wednesday.

&&

.DISCUSSION /Through Saturday/...
Issued at 109 PM MDT Sat Jul 25 2026

It`s a hot day, with temperatures already in the 95-102F range.
Scattered thunderstorms will continue to develop over the higher
terrain and spread eastward. Precipitable water values are 0.90
to 1.25 (in) across the plains, so heavy rain is possible from the
thunderstorms. Gusty outflow winds up to 50 mph are also possible
near the storms. The upper level high will remain centered over
the Central Rockies through Sunday. This will lead to a very warm
night and hot temperatures again Sunday, possibly a couple degrees
warmer. Some recorded highs today and Sunday will likely be tied
or broken.The airmass dries a little Sunday, but enough moisture
will be present for isolated to scattered thunderstorms. Coverage
should be slightly less than today`s.

Monday`s forecast will be more challenging and uncertain as a
shortwave trough lifts northeast across Colorado while the center
of the upper level high is nudged south. We`ll see an increase in
moisture with precipitable water values climbing to around 1.25 to
1.5 (in) across the plains, which is well above normal (~99th
percentile at 1.5 (in)). The increased moisture and shortwave are
expected to bring cloud cover Monday morning and possibly showers.
Temperatures will be cooler, but by how much depends how
extensive the cloud cover ends up being. Instability may also be
limited if clouds linger for most/all of the day. However, the
shortwave may help trigger showers and storms, making the forecast
a tricky one.

The center of the high slowly shifts south and westward Tuesday
and Wednesday, resulting in west to northwest flow aloft over
Colorado. Monsoonal moisture will be plentiful, with readings
continuing to be well above normal. This is expected to produce
scattered to numerous showers and thunderstorms Tuesday and
Wednesday. Temperatures will cool a little due to the increased
moisture and the high`s center shifting southwest of the area. By
Thursday, the high is expected to be near the Four Corners. This
is expected to continue the slightly cooler temperature trend with
highs in the upper 80s to mid 90s. The amount of moisture becomes
less clear, though scattered showers and thunderstorms are still
expected. Northwest flow aloft continues for Friday and Saturday.
Model consensus favors less moisture, which should result in
fewer showers and thunderstorms.

&&

.AVIATION /18Z TAFS through 18Z Sunday/...
Issued at 1121 AM MDT Sat Jul 25 2026

Winds will gradually become more SE by 21z with a few gusts to 20
mph. Sct higher based -shra along with an isold tstm will be
possible between 21z and 01z with brief gusty winds up to 35 mph.
After 01z there still may be a few lingering -shra thru 03z with
brief gusts to 30 mph. Winds by early evening will become SSW and
will stay that general direction overnight.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 9 PM MDT this evening for COZ038>040-043.

Heat Advisory from 10 AM to 9 PM MDT Sunday for COZ038>040-
042>051.

&&

$$

DISCUSSION...12
AVIATION...RPK

NWS BOU Office Area Forecast Discussion