451
FXUS65 KBOU 121134
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
534 AM MDT Sun Jul 12 2026

.KEY MESSAGES...

- Prolonged period of hot weather through the week ahead.

- Only hints of monsoon moisture reaching the high country by late
  in the week or next weekend.

- Prolonged hot and dry conditions will bring fire weather
  concerns although we`ll likely stay just shy of Red Flag
  criteria most days.

&&

.DISCUSSION /Through Saturday/...
Issued at 136 AM MDT Sun Jul 12 2026

The forecast pattern has not changed significantly at any point in
the last few days, and we look well on track for an extended
period of above normal to record high temperatures across the I-25
corridor and high country through the upcoming week.

The center of an expansive upper level ridge is now somewhere over
Wyoming, and the ridge is expected to continue strengthening today
while drifting off to the north and east. Like yesterday, we`ll be
on the edge/gradient of the mid-level thermal ridge, with the
warmest 700mb temperatures off to the west of our CWA. With little
change in the overall synoptic pattern, today`s highs look like
they`ll end up pretty similar to what we saw on Saturday... with
upper 80s to low 90s across North Park/Middle Park, mid to upper
90s for most of the urban corridor, and upper 80s to mid 90s
across the plains. Though there is some modest surface/boundary
layer moisture across the plains due to the southeasterly surface
flow, forecast soundings yield meager MLCAPE values... with no
real mechanism for any convection. There may be a couple of
showers across South Park and the surrounding higher terrain, but
moisture/instability is much more limited there.

The hot/dry pattern is expected to continue on Monday, with highs
potentially a degree or two warmer than today. Combined with mild
overnight low temperatures, Heat Risk values are a little closer
to the "Significant" category... it`s possible a Heat Advisory
will be needed for Monday/Monday night across the urban corridor.

The ridge across the northern CONUS will be slow to break down
through the week, and record high temperatures are likely to
continue across the higher elevations... which will remain closer
to the thermal ridge axis. Our deterministic forecast still calls
for daily, if not all time record high temperatures for many of
the longer term climate sites across Jackson/Grand/Summit
counties from Tuesday through Thursday.

Meanwhile, given the continued hot and dry conditions and a
gradual increase in the easterly surface flow, we could start to
see elevated to critical fire weather conditions develop around
the same time. At this point there`s rather high uncertainty
regarding how much overlap in gusty winds and critical relative
humidity across any given zone, but Fire Weather Watches may be
needed later in the week, mainly across the higher elevations.

As we get towards next weekend, moisture associated with the
monsoon will slowly start to work its way towards our forecast
area. Guidance continues to be a bit slower with the eastward push
due to unfavorable positioning of the ridge. Guidance has
consistently shown better PWs arriving sometime around Day 6 or
Day 7... but until we see this finally start advancing forward,
it`s difficult to have too much confidence. On the more optimistic
side, there is still a strong ensemble signal that once this
moisture arrives, it should stick around.

&&

.AVIATION /12Z TAFS through 12Z Monday/...
Issued at 533 AM MDT Sun Jul 12 2026

VFR conditions through the TAF period. Winds should become light
and variable over the next few hours, before settling on a steady
east/east-southeast wind by around 18z. Winds should then slowly
turn clockwise through the afternoon and evening. There may be a
brief period this evening or early overnight where drainage flow
is a bit stronger than normal, with a few gusts of 20-25kt.

&&

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

&&

$$

DISCUSSION...Hiris
AVIATION...Hiris

NWS BOU Office Area Forecast Discussion