651
FXUS65 KBOU 121132
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
532 AM MDT Fri Jun 12 2026

.KEY MESSAGES...

- Elevated to near critical fire weather conditions likely today
  and possible on Saturday across the high country.

- Trending cooler for Saturday and Sunday behind a cold front.

- The best chances for precipitation this week will be Sunday
  into Monday before another warming trend develops, peaking by
  midweek.

&&

.DISCUSSION /Through Thursday/...
Issued at 1234 AM MDT Fri Jun 12 2026

Water vapor imagery and current observations show it`s still dry
across a large portion of the forecast area late tonight, with
relative humidity (RH) values struggling to recover across the
urban corridor where values range from roughly 20%-40%, and only
slightly higher values are observed in our mountain valleys where
values range from 30%-40%. Temperatures are expected to heat back
up to summer-like values today, with upper 80s to low 90s
forecast across the lower elevations, and 70s for the mountain
valleys. The main concerns for today continue to be with elevated
to critical fire weather conditions developing as 40kt to 50kt,
500 mb zonal flow aloft will be in place across the region. This
will bring gusty winds to the higher elevations and high mountain
valleys, where the poor RH recoveries are currently in place.
While winds and RH are expected to reach critical values across
much of the higher elevations, fuels are not considered critical
at this time where the gusty winds and low RH will coincide.
Across the lower elevations, we are expecting RH values to drop
into the single digits, but winds will be the limiting factor to
keep critical fire weather conditions from developing. There is a
chance (~20%) that some of the gustier winds mix down to the
surface this afternoon across the lower elevations, though if this
does occur, it wouldn`t be for a long enough time period to
warrant any fire weather highlights, but we could see some patchy
elevated to critical fire weather conditions in the later
afternoon if this happens.

A cold front is expected to move from north to south across the
forecast area late tonight that will bring cooler temperatures
back for Saturday. This will also increase low-level moisture
across the lower elevations which will limit fire weather
concerns, despite gusty northeast winds expected to stick around
through the day behind the front. Though our mountain valleys will
still see RH drop into the low to mid teens where we will see
winds gust between 20-30 mph in the afternoon. This will keep
elevated to patchy near-critical fire weather conditions in place
in these locations once again. We will start to see precipitation
chances increase by Saturday afternoon as upslope flow will
increase moisture enough for isolated to scattered shower
potential, mainly for the southern foothills and Palmer Divide.

Further cooling is expected for Sunday as a secondary surge of
cooler air will stream in from the north, dropping temps to below
normal values. There are still some inconsistencies across
guidance with how much we cool, but for now it looks like
temperatures will struggle to get out of the 60s across the
plains so have started to blend cooler temps in with the
expectation that the NBM will trend cooler in the next few runs.

There will be a few chances for some light precipitation through
the weekend, but ensembles have trended drier over the past few
runs. The best chances will be Sunday afternoon and evening as a
shortwave looks to move across the Rockies. Areas to have the best
chances will be our southern foothills and Palmer Divide, but QPF
totals don`t look too impressive, with totals ranging from a few
hundredths on the northern extent to a few tenths possible along
the Palmer Divide.

By midweek next week, hot temperatures are expected to return as
ensembles show mid to upper 90s possible once again across the
plains, with some locations pushing towards the triple-digits.

&&

.AVIATION /12Z TAFS through 12Z Saturday/...
Issued at 514 AM MDT Fri Jun 12 2026

VFR conditions expected through the TAF period. Southerly winds
are in place with gusts between 20-25 kts at KDEN/KAPA and are
expected through about 12-14Z. Confidence dwindles beyond the
morning, as hi-res models have been underperforming with regards
to gusty winds mixing down in the afternoon for the past few days.
While they portray this happening again today, with NW gusts
averaging between 20-25 kts by 20-21Z, we continue to steer our
forecast more towards MOS and climatology, which would lean
towards winds turning towards the NE to SE for the afternoon and
evening at KDEN/KAPA with much lighter speeds. KBJC will have a
better shot at seeing some of the stronger gusts, so have kept the
TEMPO for this potential through the afternoon. Confidence stands
at about a 60% chance for the current TAF to pan out, and about
30% the gusty NW winds mix down. If the stronger winds win out,
should see them diminish between 0-2Z and turn towards drainage
for a few hours before a cold front is expected to turn winds to
the north late tomorrow night. Looking like the cold front should
start moving across the northern TAF sites between 11Z-13Z,
reaching KAPA about an hour after passing through KDEN/KBJC.
Gusty north to northeast winds are expected with the frontal
passage, with gusts between 20-30kts possible as it passes.

&&

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

&&

$$

DISCUSSION...9
AVIATION...9

NWS BOU Office Area Forecast Discussion