918
FXUS65 KBOU 152041
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
241 PM MDT Mon Jun 15 2026

.KEY MESSAGES...

- Heat builds through midweek, with the warming trend peaking
  Wednesday. Some plains locations could see afternoon highs in
  the mid to upper 90s.

- Increasing fire weather concerns on Tuesday with widespread
  critical fire weather conditions possible on Wednesday.

- More active weather may return by the weekend.


&&

.DISCUSSION /Through Monday/...
Issued at 235 PM MDT Mon Jun 15 2026

Overall, it will be a hot, dry, and windy week with limited rain
chances. Fire weather concerns will increase throughout the week
likely peaking for our area on Wednesday. A ~590 mb ridge over the
southwestern United States will remain the driving force of our
weather for the majority of the week. The jet stream will
generally remain just to our north and east this week, but will
briefly move into Colorado on Wednesday.

The rest of today will be nice with temperatures a touch below
average- right around 80 degrees. Current GOES-19 satellite
imagery shows cumulus clouds over the western Palmer Divide and in
the mountains. There is a very low chance of rain showers (around
10%) for the southern mountains and Palmer Divide this afternoon
into the early evening with little to no measurable precipitation.
After today, the heat is on with our forecast calling for
temperatures in the 90s for nearly all the plains on Tuesday,
Wednesday, and Friday.

Tuesday will feature highs for the plains right around 90 degrees
as the ridge to the southwest strengthens and moves a bit closer.
Winds in the 500 to 700 mb layer will be a little stronger-
around 35 knots. Therefore, it will be another windy day in the
mountains with gusts of 30 to 40 mph expected and some stronger
wind gusts of up to about 30 mph possibly spreading into northern
Larimer and Weld counties in the afternoon.

Wednesday is still shaping up to be a very hot day for our area.
Northeast Colorado will be located in the right exit region of a
500 mb jet. Winds in the 500 to 700 mb level could reach as high
as 50 knots. This will promote subsidence, low RH values, and some
decent downsloping winds (compressional heating) putting us at
risk of fire and/or heat risk headlines. Ensemble guidance
continues to run a touch cooler than the deterministic models over
the last several runs- low to mid 90s vs. mid to upper 90s for
the Urban Corridor. The biggest question in this forecast remains
the timing of the surface cold front on Wednesday
afternoon/evening. The current forecast continues to lean toward
an afternoon arrival in our northeast counties and thus high
temperatures closer to 90 degrees in those locations with mid 90s
for the Urban Corridor. For now, there is still enough uncertainty
on the fuel status and with the timing of the front that we have
held off on any fire headlines for the Urban Corridor and adjacent
plains, but have issued a Fire Weather Watch for the mountains
and high valleys. See the Fire Weather Discussion for more
information. Heat risk headlines for Wednesday are possible,
especially for the Urban Corridor and adjacent plains, but we will
likely fall just short of criteria.

The cold front will bring one day of minor relief on Thursday. It
will be similar to today with temperatures back into the low to
mid 80s. The ridge will build back in on Friday over the southwest
United States and send high temperatures right back to above
average. By this weekend, the ridge will somewhat break down and
low rain and/or thunderstorm chances could enter the forecast
associated with a trough. Zonal flow looks to take hold early next
week with high temperatures generally still above average.

&&

.AVIATION /18Z TAFS through 18Z Tuesday/...
Issued at 1205 PM MDT Mon Jun 15 2026

VFR expected through the TAF period. Skies are clear and winds are
light and variable across most of eastern Colorado at this time. NNE-
NE winds will pick up slightly this afternoon, although they will
remain under 10KT. An isolated dry microburst could be possible in
the vicinity of KAPA late this afternoon as virga showers move off
the high terrain and DCAPE values sit around 800 J/kg. However, no
precipitation is expected. Weak S-SW drainage winds will set up
by 06Z tonight and become variable by 14Z Tuesday morning. Flow
aloft and near the surface will remain weak, with winds staying
variable for the first half of the day to a light NW wind in the
afternoon.

&&

.FIRE WEATHER...
Issued at 235 PM MDT Mon Jun 15 2026

This week will be windy in the mountains and mountain valleys and
will bring elevated to critical fire weather conditions nearly
every day. Gusts of 30 to 40 mph are expected today and tomorrow
with some locally higher wind gusts possible. Some stronger wind
gusts of up to about 30 mph are possible into northern Larimer and
Weld counties tomorrow afternoon. Relative humidity will be in
the upper teens to lower 20s for the mountains/valleys today and
then will be in the teens nearly area wide on Tuesday. Some
elevated to critical fire weather conditions are possible for
Larimer and Weld counties on Tuesday.

Wednesday will bring more widespread elevated to critical fire
weather conditions. RH will drop into the upper single digits and
lower teens for the mountains, I-25 Urban Corridor, and adjacent
plains. Winds for the mountains will be a tad stronger than the
previous two days- wind gusts around 30 to 45 mph with some
locally higher wind gusts. On Wednesday, wind gusts of 25 to 35
mph are possible for the Urban Corridor and adjacent plains. This
will lead to several hours of elevated to critical fire weather
conditions. We have gone ahead and issued a Fire Weather Watch for
Wednesday afternoon and early evening for the mountains and high
valleys given recent fuel status updates from our partners. In our
northeast counties, the incoming cold front could limit the scope
of fire weather conditions in these areas by providing slightly
higher RH values. Elevated to critical fire weather conditions
will remain possible on Thursday and Friday for the mountains and
valleys with continued breezy conditions and low RH values.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Wednesday afternoon through Wednesday
evening for COZ211>214-217-218.

&&

$$

DISCUSSION...MV
AVIATION...AA
FIRE WEATHER...MV

NWS BOU Office Area Forecast Discussion