864
FXUS65 KBOU 242341
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
541 PM MDT Tue Mar 24 2026

.KEY MESSAGES...

- Record heat almost a certainty for Wednesday. Bigger questions
  surrounds whether we approach or tie monthly record highs set
  just last week.

- Elevated to critical fire weather conditions, mainly on
  Wednesday.

- A cooldown arrives sometime Thursday, with the coolest day on
  Friday. Then warming well above normal again for the weekend into
  early next week.

- Signs of a pattern change by the mid to latter portions of next
  week, but highest chances of meaningful precipitation confined
  to the mountains.

&&

.DISCUSSION /Through Tuesday/...
Issued at 157 PM MDT Tue Mar 24 2026

An upper level high centered along the US/Mexico border will
continue to dominate our weather through Wednesday. Despite
similar temperature profiles, there are some subtle differences
in this heat dome versus the one late last week. This time, there
is a little more mid/upper level moisture rotating around it.
That means three things...1) we`ll start to see an increase of
clouds tomorrow afternoon, 2) humidities (while still being very
low) won`t plunge into the mid/upper single digits, and 3) maximum
potential temperatures may not be met. That said, we`ll be
starting off with shallow inversions and a light downslope
component which means a quick warmup can be expected. Record
monthly temperatures were shattered late last week by several
degrees in many locations, and this thermal profile would suggest
we get close if not break a couple more. However, with the above
mentioned mid/upper level moisture we`ll likely end up on the
ever so slightly cooler side of earlier guidance. Even then, we
should still be very close to tying or breaking the monthly March
record in Denver, since we "only" hit 86F last Saturday. Other
locations will be much more difficult and should remain a couple
degrees shy of the monthly records. Nonetheless, daily records at
most of our long standing climate sites will be shattered by 5-10
degrees!

With the mid level moisture arriving late in the day, it won`t be
impossible for some high based light showers or virga. DCAPE
increases to near 1300 J/kg on the plains so any high based
showers/virga would be capable of producing wind gusts to at least
40 mph in the very late afternoon or evening hours. The chance of
any thunder is minuscule given MLCAPE less than 100 J/kg in most
areas. Finally, winds will tick up a little, but mainly over the
high country. See Fire Weather discussion below.

On Thursday, a cold front arrives and latest trends are a little
quicker with the frontal passage. Cold advection kicks in so
temperatures will likely see an early/mid day high on the plains,
with steady or even slowly falling temperatures in the afternoon
hours given rather strong cold advection. Given an earlier
arrival, we`ve trimmed back our high temperature forecast a few
degrees for Thursday with mostly 60s to lower 70s expected across
the plains, but still lower 80s on the south side of the Palmer
Divide. And there`s still some potential for a high bust if the
front arrives even earlier. Northeast winds will be rather gusty
behind the front, with gusts of 30-40 mph expected east of I-25.
Meanwhile, mountain areas will only see a couple degrees of
cooling due to significantly less impacts from the front. Enough
mid level moisture and upslope to produce a few showers across the
mountains and adjacent plains, but ensemble guidance is meager
with precipitation amounts and in almost all cases less than 0.1".

Friday is still on course to be the coolest day with highs holding
in the 50s across most of the plains.

Then a warmup quickly resumes for the weekend with a flat upper
ridge building back across the region, resulting in downslope
drying and warming. Eventually, some moisture gets caught under
the ridge for an increase in shower chances by Monday and Tuesday.
The better chances (40-60%) will be reserved for the mountains,
as southwest flow aloft means more downslope dominated weather for
the plains and I-25 Corridor. There is still some hope (20-30%
chance) of mainly lighter showers for the plains. Temperatures
will be well above normal Saturday through Monday (nearly 20
degrees above normal!) with highs averaging in the upper 70s to
lower 80s across the plains. Perhaps some cooling by Tuesday if
more moisture and clouds arrive.

&&

.AVIATION /00Z TAFS through 00Z Thursday/...
Issued at 541 PM MDT Tue Mar 24 2026

VFR conditions to persist through Wednesday. Winds have become
light at the Denver airports and are expected to remain light and
variable before south-southwest drainage winds kick in 03-06Z. For
Wednesday, the wind pattern after 18Z becomes messy, as a surface
trough deepens along the base of the foothills (favoring easterly
winds), and deep mixing up to 500mb (favoring westerly winds)
occurs. Models generally favor a westerly direction, but wouldn`t
be surprised if lighter variable winds occur. High based cumulus
clouds develop after 21Z Wednesday. Isolated virga showers are
expected to form, with no rain expected to reach the ground.
However, a few areas may see gusty outflow winds from this.

&&

.FIRE WEATHER...
Issued at 157 PM MDT Tue Mar 24 2026

Elevated fire weather conditions this afternoon will ease early
this evening with the loss of daytime heating and weakening winds.

On Wednesday, record warmth is once again expected. Humidity
levels will drop to around 10% across all of the plains, with
minimums of 13-18% in most of the foothills and high mountain
valleys. The flow aloft is not very strong, so even during peak
heating we think most wind gusts will stay under 25 mph across the
forecast area. However, the winds are a little stronger to the
north so gusts closer to 30 mph can be expected from Jackson
County into the far northern foothills near the Wyoming border.
Humidity levels there, however, will be more marginal. Therefore,
the overlap of having both RH and wind gust criteria met in the
same location is rather limited and not widespread enough for any
Red Flag Warnings. That doesn`t mean quick flareups can`t happen
with any wildfire starts given the crispy nature of cured fuels,
but rapid spread is not anticipated as winds remain limited in
strength.

Thursday may see elevated to critical conditions, but a faster
arrival of a cold front means these heightened fire weather
concerns would almost certainly be confined to South Park and
perhaps southern Lincoln County where warmer temperatures and
lower humidities are more likely to persist. It will be windy on
the plains with gusts of 30-40 mph behind the front, but an
increase in humidity will help offset the increase in winds.

&&

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

&&

$$

DISCUSSION...20
AVIATION...12
FIRE WEATHER...20

NWS BOU Office Area Forecast Discussion