724
FXUS65 KBOU 131104
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
504 AM 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.

- A cold front Saturday night will bring sub-freezing wind chills
  Sunday, with strong north winds and light snow to the lower
  elevations. Difficult travel expected in the mountains Saturday
  night into Sunday morning due to snow and blowing snow.

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

&&

.DISCUSSION /Through Thursday/...
Issued at 1148 PM MDT Thu Mar 12 2026

The strongest winds have largely retreated into the high foothills
and leeside slopes, although breezy conditions are lingering across
the urban corridor and most notably in the Fort Collins area, where
gusts as of 1030 PM continue to register in the 50-65 mph range.
There should be a gradual reduction in speeds through the night for
the lower elevations, but they`ll remain hefty or even strengthen
slightly for the higher elevations with gusts exceeding 70-80 mph at
times. The westerly downslope flow won`t fully die down overnight
for the urban corridor either, resulting in mild overnight lows
that may not drop below 45-50F in the warmest locations near the
base of the foothills. A little different over in our northeast
plains, where a backdoor cold front which is creeping into the
state will provide for some sub-freezing lows from roughly Fort
Morgan eastward.

This front`s impact on temperatures Friday should be limited, with a
deeply mixed profile leading to a quick emergence of breezy west
winds beginning late morning and continuing through the afternoon.
Peak wind strength will not be comparable to Thursday in the absence
of any mountain wave activity, but widespread gusts 30-45 mph
(strongest along our northern tier of counties) will nonetheless
promote critical fire weather conditions for the lower elevations as
temperatures creep into the 70`s and humidity dips into the mid
teens. The higher terrain will see a reduction in peak winds during
the afternoon, but some gusts 55-65 mph can be expected to continue.

Zonal flow aloft is set to strengthen Saturday as a shortwave begins
to dig south towards Colorado. With additional low-level warming
(highs will push into the mid 70`s for the plains), we`ll have
another day of efficient mixing, which inevitably means more (and
stronger) winds. Daytime gusts for most areas will be 10-15 mph
stronger than Friday, and be relative widespread and persistent.
It will also be both the warmest and driest day of this stretch
of higher fire danger, so critical fire weather conditions are a
sure bet. As far as the Chinook winds are concerned, cross-
sections and forecast soundings are largely unsupportive of true
mountain wave development, lacking a well-defined critical or
stable layer. A surge of stronger winds off the foothills
spreading into the urban corridor is still favored for the mid
afternoon through mid evening period, with gusts roughly 40-55 mph
(and some decay with eastward displacement into the plains), but
driven mostly by brute force as pre-frontal winds peak in
strength.

By early Saturday evening, a strong cold front will push into our
area and progress south into the overnight hours. Increasing mid-
level moisture will impinge on the high country starting Saturday
evening leading to development of snow showers, spreading north to
south through the night. Snowfall will be boosted by healthy
orographic and jet-induced lift, as well as robust frontogenesis,
and mountain travel will become quite difficult across our
mountains. Blowing snow and significant visibility reductions will
be an additional concern that could snarl traffic even into the
Sunday morning timeframe as snowfall tapers. Winter Weather
Advisories have been issued as a result. The lower elevations won`t
be entirely left out, with a quick burst of banded snow showers
increasingly likely for the overnight and early morning hours as
temperatures take a nosedive. Despite Saturday`s warm temperatures,
the much colder airmass behind the front should allow for
accumulation on roads, although with limited moisture and the quick-
hitting nature of this system, amounts for most areas won`t be too
impressive (mostly 1" or less north of the Denver metro and for the
plains). That said, localized higher amounts of 2-3" are certainly
possible contingent on localized banding, and brief northerly
upslope flow would favor areas to the south of Denver, including the
Palmer Divide, for the highest accumulations. Snow will diminish
rather quickly Sunday as subsident flow takes hold, with wind
becoming the main story yet again. Post-frontal north winds will
gust 45-60 mph for much of the lower elevations well into the
afternoon, strongest in the rural plains, and will make for cold
wind chills through the day.

Our hectic stretch of weather looks to subside Monday as the trough
exits to our east and high pressure begins to expand over the
Western CONUS. This expansion will be steady and produce a rapid
warming trend through Tuesday, when 70`s looks to make a return.
That trend will slow the rest of the week, but certainly not cease,
with continued warming expected. Ensemble guidance indicates
considerable amplification of the high pressure as it migrates
closer to the Intermountain West, and confidence continues to rise
in a prolonged period of highly anomalous March heat that is poised
to threaten records.

&&

.AVIATION /12Z TAFS through 12Z Saturday/...
Issued at 452 AM MDT Fri Mar 13 2026

Winds at DIA have been a nightmare all night as they have remained
from the west and gusty at times. To complicate things even
further, there is a cool front just to the NE and E of DIA which
has been slowly trying to move westward. If the westerlies weaken,
then may see a brief wind shift to the east before things mix out
later this morning. Along and to the east of this front, smoke
from fires over Nebraska has been moving westward across the
plains overnight.  Visibility on some sensors has dropped down
to 1-3 miles. At this point, I believe there is only a 10 percent
chance of visbility restrictions this morning at DIA if the cool
front were to move across.

Don`t think the cool front will affect APA or BJC. Winds have been
gusting all night at BJC from the WNW so winds may just stay gusty
from the west or WNW all morning.

By 16z should see decent mixing occur with winds mainly from the
west at APA and DIA.  By 19z, winds at all of the airports should
be WNW with gusts from 30 to 35 mph thru the aftn.

For tonight, winds should decrease by 01z and become more SW or
SSW by 05z.

Finally, VFR conditions are expected thru the period except for
a 10% chance of lower visbility at DIA thru 15z due to smoke
behind the cool front.

&&

.FIRE WEATHER...
Issued at 1148 PM MDT Thu Mar 12 2026

Critical fire weather conditions will become widespread for the
lower elevations this afternoon as deep mixing allows for west
winds 15-25 mph and gusts 25-40 mph (strongest near the WY/NE
state line) to surface. Humidity will hover between 12 and 18%,
generally driest for the Denver metro and southern plains. Gusty
winds will subside quickly in the evening and retreat into the
foothills and mountains, however downslope flow will keep
overnight humidity recoveries low (25-35%) along the base of the
foothills and portions of the Denver metro.

West winds are set to strengthen Saturday ahead of an approaching
storm system, with sustained speeds 20-30 mp and gusts 35-50 mph
expected to be widespread. Saturday will also be the warmest and
driest day of this period of enhanced fire danger, with highs into
the mid 70`s and potential for humidity to locally lower into the
single digits in the plains, contributing to heightened fire
weather concerns. A window of stronger gusts for areas along and
west of I-25 is possible starting mid-afternoon with gusts up to
55 mph at times. Saturday evening, a potent cold front will
descend south and bring a shift in prevailing winds (becoming
north). These winds will be strong and will continue well into
Sunday, with gusts 40-60 mph for the lower elevations. However,
the front will be accompanied by notably higher humidity as well
as some light snow through Sunday morning.

After the brief cooler conditions on Sunday, much warmer and drier
conditions are expected to return quickly and build through the
week, with periods of elevated to near-critical fire weather
conditions possible as early as Tuesday depending on exact winds
as well as fuel susceptibility.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 7 PM Saturday to 8 AM MDT Sunday
for COZ031-033-034.

High Wind Warning until noon MDT today for COZ033>036.

Red Flag Warning from 11 AM this morning to 8 PM MDT this
evening for COZ238>251.

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

&&

$$

DISCUSSION...BRQ
AVIATION...RPK
FIRE WEATHER...BRQ

NWS BOU Office Area Forecast Discussion