039
FXUS65 KBOU 051155
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
555 AM MDT Sun Jul 5 2026

.KEY MESSAGES...

- A few storms expected each day of the coming week, with the
  highest probabilities shaping up for Tuesday and Wednesday from
  the Front Range eastward.

- Isolated dry thunderstorms in mountains could spark new
  wildfires.

- Good agreement that significant heat wave arrives by next
  weekend.

&&

.DISCUSSION /Through Saturday/...
Issued at 127 AM MDT Sun Jul 5 2026

Summer warmth will continue today as upper-level ridging builds
across the Rockies. This will warm afternoon high temps a few
degrees over Saturday`s with 90s forecast across the plains, 70s
and 80s for our mountain valleys. We will have less moisture to
work with, but there will still be enough for some high-based
showers/weak storms in the afternoon and evening, mainly for the
southern foothills and Palmer Divide. The main concerns will be
with gusty outflows/microbursts, as DCAPE is expected to range
between roughly 1200-1600 J/kg. Overnight low temperatures are
forecast to be 5 to 10 degrees above normal, with 50s and 60s
expected for the plains, and 40s for our mountain valleys.
Guidance suggests patchy smoke will creep back northward along the
Front Range and urban corridor with overnight southerly winds
tonight that will make for some potential hazy skies on Monday.

700mb temperatures will increase by about 4 degrees C on Monday as
the ridge persists, translating to afternoon high surface temps
warming a few more degrees over Sunday`s. There will be a slight
chance for showers and weak storms once again, with the best
chances along the Front Range, Palmer Divide, and Cheyenne Ridge.

Precipitation chances will increase Tuesday through Thursday as
PWAT values are expected to increase to above normal values.
Instability and shear are looking to increase to values worthy of
supporting at least a few stronger to severe storms on Wednesday
and Thursday (30-35kts bulk shear and 500-1200 J/kg of MLCAPE),
with upper-level support from passing shortwaves to the north.
These shortwaves will flatten the ridge for mid-week, but it`s
looking like it will build back with force by the weekend.

There is still consistent agreement amongst guidance with 500 mb
heights showing highly significant +2.0 to +2.5 sigma anomaly,
representing an extreme high pressure ridge that will likely bring
significant subsidence and low-level warming and drying across
the forecast area. Ensemble means continue to show well-above
normal temperatures by Saturday afternoon, and near record-breaking
temperatures possible Sunday (KDEN record high for 7/12 is 102F
and the current forecast high is 101F).

&&

.AVIATION /12Z TAFS through 12Z Monday/...
Issued at 542 AM MDT Sun Jul 5 2026

South to south-southwest winds are in currently in place at KDEN
and KAPA this morning, with light and VRB winds at KBJC. Webcams
show fairly smoky skies across the airfield at KDEN as portrayed
by hi-res guidance, which could cause some impacts to slant-range
vis this morning.

The main concern for the TAF period continues to be the potential
for some gusty high-based virga showers this afternoon/early
evening, with KAPA having the best chance for precipitation with
anything that develops. Instability is expected to be marginal,
with just enough for a brief thunderstorm to develop in the
southern foothills that could bring a TS close to KAPA, though
there is slightly higher confidence that anything that forms would
weaken before it makes it to the terminal. As it weakens, there
would be potential for -SHRA with gusty outflows between 25-35kts
with enough DCAPE (1200-1500 J/kg) to support microbursts. While
there is higher confidence for impacts at KAPA, there is still a
non-zero chance KDEN/KBJC sees some gusty outflows, but there is
not enough confidence to put in the TAF at this time outside of
KAPA. Therefore, have included VCSH with the expectation we see
some scattered cloud decks around 12,000` AGL while showers are in
the area. The best timing for gusty winds/microbursts would be
between 20Z to 1Z this afternoon/evening.

Hi-res guidance suggests that smoke will increase along the Front
Range late tonight, therefore have reintroduced it into the TAF
with the expectation we see some slant-range vis concerns return
by sunrise Monday morning.

&&

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

&&

$$

DISCUSSION...9
AVIATION...9

NWS BOU Office Area Forecast Discussion