459
FXUS65 KBOU 132033
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
233 PM MDT Fri Mar 13 2026

.KEY MESSAGES...

- Gusty west winds, strongest Saturday, and warm/dry weather will
  sustain critical fire weather conditions for the plains/I-25
  corridor through Saturday. The mountain valleys will see
  elevated fire weather conditions.

- Difficult travel expected in the mountains Saturday night into
  Sunday morning due to snow and blowing snow.

- A cold front Saturday night will bring sub-freezing temperatures
  with strong north winds and light snow to the lower elevations.

- Rapid warming begins Monday into Tuesday, potentially
  culminating in record-breaking temperatures mid to late next
  week.

&&

.DISCUSSION /Through Friday/...
Issued at 212 PM MDT Fri Mar 13 2026

A shallow cold front pushed across the northeast plains this
morning with east-northeast winds behind it. Unfortunately, this
pushed smoke from the large Nebraska fires into northeast
Colorado. Visibility in Greeley and Fort Morgan decreased to as
low as 1 mile with poor air quality. Sunshine has allowed
temperatures across northeast Colorado to warm into the 60s which
has improved mixing and visibility and air quality as well. With
the improved mixing, west winds will increase soon and the smoke
will leave northeast Colorado.

The Red Flag Warning is on track today. The fire weather
conditions are discussed further in the fire weather section
below.

The High Wind Warning for this morning was allowed to expire at
noon as wind speeds have decreased below warning criteria. Wind
gusts up to 65 mph are possible across the mountains and foothills
throughout the rest of the day. Otherwise, temperatures will be
roughly 15 degrees above normal today.

On Saturday, winds aloft will turn to due west and will increase
in speed ahead of a digging shortwave trough over Idaho and
Wyoming. Looking at cross sections, there does not appear to be
much of a stable layer/inversion or a strong mean state critical
layer. However, there will be strong gradient winds that will
develop across the vast majority of our forecast area. With such
warm and dry conditions, soundings show a very deep boundary layer
which will be able to mix down the stronger winds aloft. Winds in
the mountains and foothills will gust up to 70 mph and winds
across the I-25 corridor and plains will gust up to 55 mph. Both
areas are currently forecast to be just below High Wind Warning
criteria but if there is confidence in higher winds than
currently forecast, a High Wind Warning may be needed.
Temperatures will be well above normal (15-20 degrees) with highs
in the low to mid 70s across the plains. For all those who will be
recreating outside tomorrow, the winds may make for a poor
experience despite the pleasant temperatures.

The aforementioned shortwave trough will move into Colorado
Saturday night. This will have a surface cold front associated
with it that will have an extremely sharp temperature gradient and
strong winds behind it. Temperatures may drop 15 degrees in 10
minutes behind this front. The front will also provide forcing for
a couple of bands of precipitation to form across the plains.
This precipitation may briefly fall as rain before quickly
transitioning over to snow for the rest of the event. Of note, the
vast majority of ensemble members from all global models have
accumulating snow in Denver. With that being said, only a trace
to 1" of snow is expected for the Denver metro with minimal
impacts to travel conditions. The Palmer Divide may have larger
impacts as more snow is expected to fall there. The Palmer Divide
is expected to see 1-4" of snow and with strong winds behind the
front, some blowing and drifting snow may be possible. Those
traveling along I-25 over the Palmer Divide may experience poor
travel conditions late Saturday night.

As for the mountains, the trough will bring a quick and somewhat
intense round of snow Saturday evening through Sunday morning. The
strong west-northwest winds will create great orographic flow for
the northern mountains of Colorado. 4-10" is expected mainly above
8,500 feet. With winds gusting to 65 mph, whiteout conditions are
possible Saturday night and hazardous travel conditions are
expected. The snow will come to an end quickly Sunday morning but
blowing snow may still linger. The Winter Weather Advisory was
extended to 6pm Saturday through Sunday at 9am.

The next impact will be high winds Sunday. Gusts could reach 60
mph right behind the cold front late Saturday night across the
plains. Then, early Sunday morning through the afternoon, strong
northerly 700 mb winds will mix down to the surface, thanks to
strong cold air advection, and create high winds across the
eastern plains of Colorado. A High Wind Warning was issued for the
eastern plains and Palmer Divide from 4am through 6pm for gusts
up to 65 mph. There may be blowing dust in areas that do not
receive much snow Saturday night.

Quieter weather will move in Monday and Tuesday as a ridge aloft
moves overhead.

Later next week may end up being one of the more significant
recording breaking warm weather periods for Colorado. 500 mb
temperatures may reach above 591 dm over western Colorado Thursday
through Saturday. The ensemble guidance shows the 50th
percentile is in the mid 80s for highs in Denver for the weekend
of March 21/22. If optimal downslope winds were to occur one of
those days, Denver could hit 90 degrees, which some ensemble
members do indicate is a real possibility. The earliest 90 in a
calendar year for Denver is April 30th. To even come close to that
would be very significant. Regardless of getting close to 90
degrees, breaking the all time warmest March high temperature for
Denver of 84 seems likely.

&&

.AVIATION /18Z TAFS through 18Z Saturday/...
Issued at 158 PM MDT Fri Mar 13 2026

Models keep the strong westerlies going at DIA through the afternoon
into the early evening hours.  Will go with gusts as high as 35
knots through about 00Z. Models do eventually go to true drainage
directions right after 06Z with fairly weak speeds. On Saturday,
strong westerlies winds are expected again by about 18Z. There
will be no ceiling issues.

&&

.FIRE WEATHER...
Issued at 212 PM MDT Fri Mar 13 2026

Many locations across the plains are reaching Red Flag criteria
this afternoon. A mountain wave cloud is reducing temperatures
slightly which is helping us avoid more severe fire weather
conditions but there will be an extended period of critical fire
weather conditions through the evening.

Another Red Flag Warning is in place for Saturday. The question
for Saturday will not be whether it will be critical fire weather
conditions or not. The question will be whether there will be
extremely critical fire weather conditions or not. Some of the
more recent high resolution guidance leaves the door open for
extremely critical fire weather conditions for the western I-25
corridor. Some guidance suggests winds could gust up to 80 mph in
Boulder and Golden during the afternoon, the warmest and driest
part of the day. If there is better confidence in these wind gusts
with later forecast updates, it is possible our office could
decide to go with a PDS Red Flag Warning for Boulder and Jefferson
Counties. However, there is not enough confidence in the strength
of the winds to increase the wording. Nonetheless, this will be a
high end fire danger event for our forecast area.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 6 PM Saturday to 9 AM MDT Sunday
for COZ031-033-034.

Red Flag Warning until 8 PM MDT this evening for COZ238>251.

Red Flag Warning from 11 AM to 9 PM MDT Saturday for COZ238>251.

High Wind Watch from late Saturday night through Sunday
afternoon for COZ041-042-044>051.

&&

$$

DISCUSSION...Danielson
AVIATION...RPK
FIRE WEATHER...Danielson

NWS BOU Office Area Forecast Discussion