037
FXUS65 KBOU 161935
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
135 PM MDT Tue Jun 16 2026

.KEY MESSAGES...

- Warm this week, with heat peaking Wednesday. Portions of the
  plains could see afternoon highs in the low to mid 90s.

- Elevated to critical fire weather conditions possible each day
  this week, with widespread critical fire weather conditions
  likely for the mountains and valleys on Wednesday.

- More active weather may return by the weekend into early next
  week.


&&

.DISCUSSION /Through Tuesday/...
Issued at 125 PM MDT Tue Jun 16 2026

This week continues to look hot, dry, and breezy. We are on track
for highs today around 90 degrees for the plains with very few
clouds. It will be windy in the mountains and high valleys given
cross barrier flow of about 25 to 35 knots aloft. This will
translate to winds gusts of 25 to 35 mph in these areas with some
isolated higher gusts for the mountains. Portions of northern
Larimer and Weld counties could see winds gusts of 25 to 35 mph as
well for a few hours this afternoon. The stronger wind gusts will
likely continue overnight for the mountains as model cross
sections suggest that the cross barrier flow strengthens heading
into Wednesday.

Tomorrow, flow in the 500 to 700 mb layer is forecast to strengthen
further to as high as 45 to 55 knots for most of the day. Wind gusts
for the mountains and high valleys will likely be between 35 and
50 mph with some isolated gusts for the mountains even a bit
higher than that. Elevated to critical fire weather conditions are
likely in those areas. We have issued a Red Flag Warning for
Wednesday afternoon for the mountains and high mountain valleys.
See the Fire Weather Discussion for more details.

The flow aloft will likely result in downsloping winds and thus
compressional heating for the Urban Corridor and adjacent plains. It
is looking more likely that the cold front will move through our
northeastern counties in the morning, keeping high temperatures in
those areas in the mid 80s to near 90. The front could potentially
stall in Weld, Morgan, and Lincoln counties or even wash out before
moving through the I-25 corridor in the early evening. There is a
low (20%) chance tomorrow afternoon that the winds do not turn to
the northwest, a shear zone develops, and/or the cold front comes
through earlier than currently expected. The HRRR, NAM Nest, and
RDPS are some models showing this scenario unfolding. These
solutions would keep winds northeast for much of the afternoon for
the Urban Corridor and thus lower our high temperatures into the
upper 80s and low 90s. Additionally, the trend noted yesterday where
the deterministic models are running hotter than the ensembles has
continued. Given all the factors noted above, we have continued to
lean the forecast toward the ensemble means with highs for the Urban
Corridor and adjacent plains in the mid 90s. This will place us just
below heat advisory criteria. We still want to emphasize that those
sensitive to heat should take precautions.

Behind the cold front on Wednesday evening, highs on Thursday will
be more seasonable for the plains- in the mid 80s. This relief will
only last for one day as the upper level ridge strengthens and moves
over southern CO and northern NM on Friday. Highs on Friday will be
right back into the low 90s.

By Saturday, the upper level ridge starts to break down as a trough
approaches from the west introducing some low rain chances for our
area and potentially slightly cooler temperatures. The highest rain
chances for our areas will be for the eastern plains, but are still
only around 20-30%. As of now, the highest chances for severe
weather are expected for parts of Western Kansas and Nebraska, but
could nudge further west into our northeastern counties. Sunday
could be another day with near normal temperatures and some low rain
chances continuing mainly for the eastern plains. Zonal flow aloft
is expected to begin next week keeping temperatures above average
with a signal from model ensembles of low rain chances continuing.

&&

.AVIATION /18Z TAFS through 18Z Wednesday/...
Issued at 1134 AM MDT Tue Jun 16 2026

VFR conditions expected through the TAF period. Light and variable
winds will become gusty northwest winds this afternoon at all
terminals. BJC will see the NW winds first, likely between 20-22Z.
The winds may not show up at DEN and APA until between 22-00Z.

Tonight, winds will have more of a westerly component than typical
drainage. Winds may vary from due west (270) to southwest (220)
at times throughout the night with speeds generally from 8-12
knots.

There is large uncertainty with the wind direction and speed
tomorrow. Most models mix the warm air down to the surface with
strong northwest winds gusting up to 30 knots. However, there is
indication that a weak cold front will move through in the morning
hours. In these cases, the northeast winds usually win out and the
northwest winds are very slow to develop. Therefore, northeast
winds were put in the forecast for the majority of the day with
northwest winds late in the afternoon.

&&

.FIRE WEATHER...
Issued at 125 PM MDT Tue Jun 16 2026

For today, wind gusts up to 40 mph are possible for the
mountains and high valleys. Eventually northern Larimer and Weld
counties could see wind gusts up to 35 mph by later this
afternoon. Relative humidity values will drop into the teens to
low 20s. The conditions do not overlap for long enough or for a
large enough area for a Red Flag Warning to be warranted for
today. Nevertheless, elevated to critical fire weather conditions
are possible today.

Strong gusts are still possible in the mountains and high valleys
tonight, but there will be some modest RH recovery. Tomorrow,
widespread elevated to critical fire weather conditions are likely
for the mountains and high valleys. Fuels are critical, so a Red
Flag Warning is now in effect for Wednesday afternoon. Wind gusts
for the mountains and high valleys will likely be between 35 and
50 mph with some isolated gusts for the mountains possibly even a
bit higher than that. Elevated conditions are likely for the I-25
corridor and adjacent plains. The latest updates from our fuel
partners show that there are not critical fuel conditions for this
area. Wind gusts for the plains should be between 25 and 35 mph
tomorrow afternoon. RH values will be in the teens areawide
tomorrow.

Thursday through Saturday will continue to bring the possibility
of elevated to critical fire weather conditions mainly for the
mountains and high valleys. Winds are forecasted to be weaker, but
will be close to criteria on each afternoon. Highlights could be
needed in a later forecast package.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from noon to 8 PM MDT Wednesday for COZ211>214-
217-218.

&&

$$

DISCUSSION...MV
AVIATION...Danielson
FIRE WEATHER...MV

NWS BOU Office Area Forecast Discussion