539
FXUS65 KBOU 250518
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1118 PM MDT Tue Mar 24 2026

.KEY MESSAGES...

- Record heat for Wednesday. We may approach or tie monthly
  record highs set just last week.

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

- A cold front arrives sometime Thursday, with the coolest day on
  Friday.

- Temperatures warm well above normal again for the weekend into
  early next week.

&&

.DISCUSSION /Through Tuesday/...
Issued at 1112 PM MDT Tue Mar 24 2026

Upper level high centered along the US/Mexico border will
dominate the weather pattern Wednesday with record highs expected
for most locations. Skies have cleared some over the past few
hours, but the next batch of high clouds over the Great Basin will
move over the area towards sunrise Wednesday morning. These
clouds move off around midday, then during the afternoon hours we
see an increase in mid level clouds. By late afternoon, soundings
show we could even see some virga with gusty outflow winds to 40
mph.

The ridge is knocked down Thursday by a shortwave trough. At the
surface a cold front pushes southwest across eastern Colorado
during the late morning and afternoon. Ahead of it, temperatures
stay mild, but winds turn northerly Thursday morning as surface
pressure lowers over southeast Colorado and Kansas. With this
setup, would not be surprised the front arrive earlier, possibly
several hours early than the models show. Thus, the temperature
forecast is highly uncertain and depends when the cold front
arrives. The front will be strong enough that temperatures are
expected to fall through the afternoon hours. Low and mid level
moisture increases behind the front, and models show deep enough
upslope flow for light rain/snow showers along the Front Range
Thursday evening. Precipitation amounts will be light and are
expected to be less than a tenth inch.

On Friday, we lose the mid level clouds, but hang onto the low
level moisture/clouds through most or perhaps all day. The cooler
air and cloud cover will keep temperatures cool with highs in the
50s across northeast Colorado.

For the weekend, temperatures quickly warmup with a flat upper
level ridging rebuilding over the region. The main upper level
high will be centered over Texas with low aloft becoming more
southwesterly Sunday and into next week. For Sunday and Monday,
highs are expected to reach the upper 70s to lower 80s, which will
be close to record highs. With the help of a weak upper level
trough, moisture increases over the region Sunday and into early
next week. The mountains will see rain/snow showers and times with
a slight chance for light rain east of the mountains.

&&

.AVIATION /06Z TAFS through 06Z Thursday/...
Issued at 1112 PM MDT Tue Mar 24 2026

VFR conditions will prevail for all terminals through the TAF
period. Light south/southwest drainage flow will persist through
Wed AM. Past 18Z, wind conditions become more variable and
uncertain 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 continue to generally
favor a westerly direction through ~22Z, followed by SE/SSE, but
lighter and more variable remains remain a clear possibility.
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, hence the PROB30 groups for KDEN/KAPA.

&&

.FIRE WEATHER...
Issued at 1112 PM MDT Tue Mar 24 2026

Record warmth is once again expected Wednesday with relative
humidity levels dropping to around 10% across the plains. In the
foothills and mountains valleys, relative humidities bottom out at
13-20 percent. The flow aloft is not very strong, so even during
peak heating we think most wind gusts will stay under 25 mph.
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,
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.

On Thursday, elevated to locally critical conditions, will be
possible in the mountain valleys with west winds gusting to 20 to
30 mph. Over the plains, a cold front pushes through during the
late morning and early afternoon. The morning may be warm and dry,
but falling temperatures and increasing relative humidities are
expected during the afternoon.

&&

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

&&

$$

DISCUSSION...12
AVIATION...BRQ
FIRE WEATHER...12

NWS BOU Office Area Forecast Discussion