537
FXUS65 KBOU 051741
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1141 AM MDT Wed Aug 5 2026

.KEY MESSAGES...

- Red Flag Warning today for the northern mountains and high
valleys.

- Elevated to critical fire weather conditions likely to persist
across the high mountain valleys through the weekend.

- Slightly warmer today before temperatures gradually warm back to
the triple digits by the weekend.

&&

.DISCUSSION /Through Tuesday/...
Issued at 210 AM MDT Wed Aug 5 2026

The cold front did not disappoint in bringing some relief from
the heat on Tuesday. We will see one more day of sub 90s today
before the upper level ridge pushes slightly east, centering
itself over the Four Corners and Great Basin for the rest of the
week. This all-too-familiar pattern will be responsible for
another hot and dry week, with temperatures still expected to
gradually warm each day, with the urban corridor reaching the mid
to upper 90s by Thursday.

The main concern for today will be with increasing northwesterly
flow bringing gusty winds to the higher elevations where very low
relative humidity will be in place (single digits). A Red Flag
Warning is in effect for the northern mountains and high valleys
from 12 PM to 7 PM today. Across the lower elevations, early
morning fog and low clouds will help keep cooler temperatures (mid
to upper 70s) in place across the far eastern plains, with mid to
upper 80s expected for the urban corridor. Northerly flow from an
early morning surface cyclone is expected to bring some low clouds
and potentially some fog into the urban corridor near sunrise.
This is expected to clear out through the morning, but this could
keep temperatures a few degrees cooler than forecast if it sticks
around longer than expected. While smoke will remain across the
area today, conditions should improve slightly compared to
yesterday before another surge of heavier concentrations arrives
by Wednesday morning.

Precipitation chances continue to look bleak under the persistent
ridge, with dry conditions expected through most of the forecast
period. The next opportunity for measurable precipitation arrives
Sunday afternoon as PWATs increase to near-normal values over the
mountains. Even then, precipitation amounts are expected to
remain light, with only a few hundredths possible for the
mountains from I-70 southward.

&&

.AVIATION /18Z TAFS through 18Z Thursday/...
Issued at 1116 AM MDT Wed Aug 5 2026

Current observations show winds gradually turning north/northeast
as the cyclone continues east of the terminals. Typical diurnal
wind pattern expected throughout the day with winds transitioning
to southeast and then drainage by tonight. With the low stratus
clearing in the past hour, no ceiling issues expected for the rest
of the day. However, smoke today may cause slant-wise visibility
issues this afternoon/evening.

Tomorrow morning, low stratus will form again, but will likely
stay east of all terminals. However, with dewpoint depressions
decreasing we could see haze in the morning. Guidance has
continued to indicate smoke concentration increasing by
mid-morning, which will likely cause more visibility issues
throughout the day.

&&

.FIRE WEATHER...
Issued at 210 AM MDT Wed Aug 5 2026

Dry and windy conditions are expected across the mountains and
high valleys today, where single digit relative humidity will
coincide with 25-35 mph gusts. A Red Flag Warning is in effect
for the northern mountains and high valleys from 12 PM to 7 PM
today. While winds are expected to slacken a bit on Thursday, very
dry conditions are expected to persist through the week, spreading
eastward onto the lower elevations by Thursday afternoon.
Elevated fire weather conditions are expected to persist across
the higher elevations through the week, with localized areas of
critical fire weather conditions. Winds are largely expected to
remain below critical thresholds across the plains, but single
digit to low teens RH is expected each afternoon for the majority
of our lower elevations, which will create some limited and
localized elevated to critical fire weather conditions each
afternoon this week.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 7 PM MDT this evening for COZ211>214-217-
218.

&&

$$

DISCUSSION...9
AVIATION...MAI
FIRE WEATHER...9

NWS BOU Office Area Forecast Discussion