661
FXUS65 KBOU 151846
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1246 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 1240 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.
Even though it will be windy for our mountains, fire weather
concerns remain low due to recent greenup. 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
with the timing of the front that we have held off on any fire
and/or heat risk headlines for Wednesday that could be needed,
especially for the Urban Corridor and adjacent plains.

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.

&&

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

&&

$$

DISCUSSION...MV
AVIATION...AA

NWS BOU Office Area Forecast Discussion