879
FXUS65 KBOU 041014
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
414 AM MDT Tue Aug 4 2026

.KEY MESSAGES...

- Elevated to critical fire weather conditions likely across the
  high mountain valleys through the next few days.

- Cooler today and Wednesday before temperatures gradually warm
  back to the triple digits by next weekend.

&&

.DISCUSSION /Through Monday/...
Issued at 215 AM MDT Tue Aug 4 2026

Current conditions show a dramatic difference from this time last
night, with overnight temperatures a good 15 to 25 degrees cooler
than this time last night. Today`s high temperatures are still
expected to struggle to make it out of the 70s across our lower
elevations. This cooler airmass didn`t have enough oomph to make
much of a difference in our mountain valleys, where afternoon
highs are expected to warm into the mid to upper 80s once again
today. With increasing zonal flow aloft expected to bring some
gusty winds (25-30 mph) into North and Middle Park this afternoon,
where much drier air still resides, a Red Flag Warning is in
effect from 1 PM to 7 PM for these locations as relative
humidities are expected to drop into the low to mid teens.
Precipitation chances will remain limited to the southern Front
Range and Palmer Divide this afternoon, where a few showers and
thunderstorms will be possible. Westerly flow aloft will keep
smoke around, with patchy smoke expected across the forecast area
for at least another day.

Wednesday will bring one more day of below normal temperatures to
our lower elevations, though it will mark the start of another
warming trend, with zonal flow turning more to the northwest as
upper-level ridging starts to rebuild across the west. Critical
fire weather conditions are expected across our higher elevations,
expanding slightly due to RH dropping into the single digits
coinciding with gusty winds up to 30 mph. A Fire Weather Watch has
been issued for our mountain valleys and elevations above 9,000`.

Our stretch of record-breaking heat appears poised to continue as
temperatures are expected to gradually warm each day through the
weekend, with some locations on the plains reaching the triple-
digits as early as Friday. Precipitation chances don`t return to
the forecast until late this weekend/early next week, and
confidence in any meaningful rainfall remains low.


&&

.AVIATION /06Z TAFS through 06Z Wednesday/...
Issued at 1145 PM MDT Mon Aug 3 2026

Current satellite and observations show stratus are quickly
developing along the Front Range late tonight from persistent
upslope flow. Latest KBDU METAR shows cloud base are around
6,000`AGL and approaching KBJC (already in the vicinity). With
upslope expected to remain in place overnight, continued
moistening of the lower levels should keep stratus developing and
spread eastward across the other two TAF sites within the next
hour. Latest guidance shows CIG should remain between 3,000` to
5,000` AGL before gradually scattering out after 12Z, but there is
still a low chance (10-15%) that we see a few hours of CIG as low
as 2,000` AGL, with KBJC having the best chances for this outcome.

Smoke is expected to remain in the area through the TAF period,
keeping potential for slant range visibility concerns, though
there may be a few hours of clearer skies throughout the day.

Winds are expected to maintain a NE to easterly component through
the day today. Low confidence in winds late tonight as latest hi-
res guidance shows drainage winds will struggle to settle in
as a cyclone forms near the TAF sites. Depending on where the
cyclone forms will determine wind speeds and direction as well as
where a potential shear zone forms.

&&

.FIRE WEATHER...
Issued at 215 AM MDT Tue Aug 4 2026

A Red Flag Warning is in place from 1300 to 1900 today for North
and Middle park due to gusty westerly winds to 30 mph and relative
humidities in the low to mid teens. Elevated to critical fire
weather conditions are expected to persist across the higher
elevations for the next few days due to critical fuels and RH
dropping into the single digits each afternoon. A Fire Weather
Watch in effect for Wednesday for our mountain valleys and
elevations above 9,000` where winds are expected to remain gusty
for another day (gusts to 30 mph). Winds are expected to slacken a
bit after Wednesday, but with critical fuels and RH expected to
drop into the single digits each afternoon, elevated fire weather
concerns will likely remain in place through the forecast period.

By Friday, hot temperatures are expected to return to the upper
90s to triple digits across the plains that will start to
reintroduce localized concerns for elevated to critical fire
weather conditions each afternoon through the weekend, both for
the plains and higher elevations. Precipitation chances will
remain very limited through the rest of the week.


&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 1 PM this afternoon to 7 PM MDT this
evening for COZ211-213.

Fire Weather Watch from Wednesday afternoon through Wednesday
evening for COZ211>214-217-218.

&&

$$

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

NWS BOU Office Area Forecast Discussion