137
FXUS65 KBOU 091147
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
547 AM MDT Thu Jul 9 2026

.KEY MESSAGES...

- Another round of scattered to numerous thunderstorms Thursday,
  with the severe threat expanding further west to the Front
  Range.

- Prolonged period of hot temperatures arrive Saturday, lasting
  through at least Tuesday. Thunderstorm chances remain low during
  this period.

&&

.DISCUSSION /Through Wednesday/...
Issued at 132 AM MDT Thu Jul 9 2026

Moisture will remain elevated today, with dewpoints in the upper 40s
to potentially low 60s for the plains this afternoon. This moisture
and steep low to mid level lapse rates will lead to decent
instability today (MLCAPEs around 1000 to 1800 J/kg). The
instability combined with weak upslope from east/southeast surface
winds, a weak shortwave moving over the area, and 0-6 km shear
around 30 to 45kts will provide the necessary ingredients for
scattered to numerous thunderstorms, some of which could be
severe. The main severe hazards today will be large hail and
strong winds, however we could see a landspout form if a storm
develops near the DCVZ. There will also be the potential for
localized heavy rainfall and flash flooding across the plains.
Showers and storms are expected to form in the higher terrain and
foothills in the early afternoon before moving east across the
plains throughout the afternoon and evening.

The upper level ridging will begin to build towards the area on
Friday. Weak subsidence on the backside of today`s shortwave and
ahead of the upper level ridge will put a damper on our storm
chances for Friday. However, storm chances won`t go away
completely. Dewpoints are forecast to remain in the 40s and 50s
with decent instability. Shear looks to weaken slightly for the
area on Friday, especially in our northern counties which will
limit the severe potential. The main question that remains is
where the outflow boundaries will set up on Friday from the
convection on Thursday. Convergence along any residual boundaries
and the weak upslope flow could be enough to trigger some more
isolated convection Friday afternoon, but the severe threat will
be lower (in both intensity and coverage) compared to Thursday.

The upper level ridge will continue to build over the area for the
weekend. The center of the high will move northeast throughout the
weekend, parking over the NE/SD/IA area through the middle of next
week. Under this strong ridge, we`ll see large scale subsidence and
hot temperatures. Temperatures are forecast to reach into the 90s to
around 103 degrees in the plains for the first part of next week.
The warmest temperatures are forecast to be in the northern I-25
corridor area. Right now, we have Major Heat Risk for portions of
the urban corridor and I-25 corridor for Monday and Tuesday,
including Denver, Boulder, and the Fort Collins area. This means
there is a major risk for heat related illness in these areas,
especially for people without effective cooling and proper hydration.

&&

.AVIATION /12Z TAFS through 12Z Friday/...
Issued at 540 AM MDT Thu Jul 9 2026

Isolated showers have developed over the higher terrain and
foothills and are moving east as of early this morning. There`s
uncertainty in how long they`ll survive off of the higher terrain
and their exact movement, so we have an hour or two of prob30 for
-SHRA this morning at each TAF site. Things should start to clear
 out in the mid morning before storms move into the area again for
 the afternoon. Storms are expected to form to the west of the TAF
 sites in the early afternoon and then progress east. The most
 likely storm timing is between 19Z and 23Z for KBJC and 20Z to
 23Z for KAPA and KDEN. Winds after the storms move through are
 still uncertain due to outflow boundaries, but sometime in the
 late evening to early overnight winds should turn towards
 drainage.


&&

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

&&

$$

DISCUSSION...AP
AVIATION...AP

NWS BOU Office Area Forecast Discussion