451
FXUS65 KBOU 150740
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
140 AM 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 upper 90s.

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

- More active weather may return by next weekend.


&&

.DISCUSSION /Through Sunday/...
Issued at 1157 PM MDT Sun Jun 14 2026

A building upper-level ridge over the western CONUS will be the
main driving force for this week`s forecast. This will put
northwesterly flow aloft over Colorado as we reside on its eastern
flank. A relatively hot and dry week is expected with a few cold
fronts to bring brief relief from the heat, mixed in with
multiple 90 degree days.

Today will initiate the warmup as 700 mb temps increase to around
15C, bringing surface temperatures back into the 80s across the
plains, 60s and 70s for the mountain valleys. Ensembles indicate a
significant drop in PWAT, with just enough moisture remaining
along the Palmer Divide (PWATs around 120% of normal) to keep a
few PoPs in the forecast in this location for this afternoon, but
that will be it for precipitation chances through at least
Friday.

The main weather concerns for Tuesday and Wednesday still continue
to be for fire weather. Winds and heat will increase on Tuesday
that will bring 90s back to much of the lower elevations and
breezy conditions are expected across the mountain valleys and
northern Larimer and Weld Counties. Gusts between 30-40 mph will
be possible in these areas where relative humidity is expected to
drop into the low to mid teens, but with greenup still underway in
these zones, this is looking like an elevated fire weather day. On
Wednesday, an 80kt, 500mb jet will position itself just north of
Colorado, in the northwesterly flow aloft. This will lead to
increasing winds and adiabatic warming and drying across the
forecast area. Very dry, hot, and breezy conditions are expected
to develop along the urban corridor and adjacent plains, but the
extent of how far east these conditions prevail depends on the
timing of a cold front. At this time, it still looks like we will
have critical fire weather conditions for areas along the urban
corridor and adjacent plains where fuels are considered critical,
as relative humidity in the single digits coinciding with 30 to
40mph winds is expected. The latest forecast has shown the cold
front progressing slightly sooner across the plains, and if this
continues to speed up, this would certainly limit fire weather
concerns for some of our eastern zones. Will have to monitor the
timing to determine where highlights will be needed, but we do
anticipate some areas needing highlights in the next forecast
package or two.

Thursday will be one of the aforementioned "relief" days as
temperatures drop to near-normal behind Wednesday`s front.
Expecting winds to decrease as the jet moves east, and mostly
sunny skies should prevail as the ridge also nudges eastward.

Afternoon highs are forecast to heat back up into the 90s on
Friday and Saturday before another cold front is expected to bring
some more relief for Sunday. PoPs start to enter the forecast for
the weekend, and with ensembles showing PWATs increase to around
120-130% of normal for this period with the ridge looking to
break down, this doesn`t seem unreasonable this far out.






&&

.AVIATION /06Z TAFS through 06Z Tuesday/...
Issued at 1122 PM MDT Sun Jun 14 2026

Upslope winds have continued to keep stratus in place across the
TAF sites late tonight. Winds are expected to transition to a more
southerly component in the next few hours, between 7Z-8Z, that
will start to breakup the lower CIGs and bring significant
improvements, likely scattering out fairly quickly after the
winds shift. VFR conditions are expected to then prevail through
the rest of the TAF period. Winds are expected to become light and
variable between 12Z-14Z before settling into a northeasterly
flow by 18Z through the afternoon and early evening.

&&

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

&&

$$

DISCUSSION...9
AVIATION...9

NWS BOU Office Area Forecast Discussion