448
FXUS65 KBOU 241205
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
505 AM MST Tue Feb 24 2026

.KEY MESSAGES...

- Well above-normal temperatures continue for the week.

- Strong winds expected along the east slopes of the Front Range
  Mountains and foothills through this evening, with a few gusts
  of 80-90 mph possible.

- Brief, but heavy round of mountain snow looking increasingly
  likely across the northern mountains this evening through
  Wednesday.

- Elevated to critical fire weather conditions possible across the
  plains through the rest of the week.

&&

.UPDATE...
Issued at 435 AM MST Tue Feb 24 2026

A few notes from the overnight forecast desk tonight.

First, lets talk wind. We`re starting to see winds gradually
strengthen across the Front Range this morning, with a recent gust
of 70KT at the Dakota Hill AWOS. Most high resolution models show
a sharp ramp up by the mid morning hours, along with a steady push
eastward into the foothills. A few gusts of 80-90 mph look likely
given the consistent signal across the HRRR/RRFS/WRF-ARW, with a
peak in winds sometime during the early afternoon. The last
remaining question is if any winds manage to spread anywhere near
the base of the foothills (Boulder/Highway 93 corridor). From a
purely ingredients based approach, I`m not sure we have enough of
a stable layer to bend the wave down. Not surprisingly, the
deterministic output across HREF members echo that idea, with a
majority of the winds occurring between roughly 6500-9500ft
today. Across the plains, the general forecast has not changed
significantly, with channels of gusty winds likely across most of
the I-25 corridor, and steadier gusts across the Cheyenne ridge
into far northeast Colorado.

On the other side of the divide, snow is the main story going into
Wednesday. As mentioned in the previous discussion, the plume of
Pacific moisture is rather remarkable. In fact, ensemble plume
data from CW3E classify this as a AR2 from this evening into
roughly 18z Wednesday for the Park Range... with integrated vapor
transport values near 250-350 kg/m/s (yes that`s a real unit of
measurement). The anomalous moisture is also reflected by
GEFS/ECMWF ensemble standardized anomalies... with specific
humidity/PWAT/IVT values all near 4-6 sigma, which is either near
the 99th percentile or exceeding the model climatology. However, a
few factors will limit snow amounts across the northern mountains:
(1) the deeper moisture is only available for around 18 hours,
(2) temperatures are very warm for this time of year, and (3)
lapse rates are rather poor. Snow levels hang around 8-8.5kft
tonight, and as a result snow ratios are well below climatology
for this time of year. The University of Utah`s snow ensemble
keeps snow to liquid ratios near 7-10:1 even across the higher
peaks tonight and only increases a bit tomorrow. That said, the
amount of moisture and orographic lift will be enough for warning
criteria snowfall across most of the northern mountains tonight
into the first half of Wednesday. A HRRR/RRFS blend would favor
1-2" of QPF through Wednesday afternoon... translating to roughly
8-18" of snow. In addition to upgrading the northern Front Range
mountains to a WSW, we also made various tweaks to the start times
of all of the winter weather segments.

&&

.DISCUSSION /Through Monday/...
Issued at 1134 PM MST Mon Feb 23 2026

It will be windy and warm across much of the forecast area on
Tuesday, with a High Wind Warning in place for the Front Range
Mountains, elevations mainly above 7,000 feet, and a Red Flag
Warning in place for the urban corridor and parts of the northeast
plains. Winds are forecast to really ramp up early Tuesday morning
as a mountain wave develops with increasing cross-barrier flow.
Models have stayed fairly consistent in the strongest winds starting
out at the ridgetops, then gradually migrating down the lee of the
Front Range into areas down to around 7,000 feet (think our typical
windy spots like Jamestown, Coal Creek Canyon, and Buckeye) by late
morning. West winds ranging from 35 to 50 mph will be possible, with
gusts as high as 80-85 mph in the aforementioned areas. While the
strongest winds are expected to remain at elevations above 7,000
feet, there will likely be fingers of stronger winds (35-45 mph)
that do make their way into the lower elevations that will coincide
with low RH values (10-15%), leading to critical fire weather
conditions developing from late morning through the afternoon.
Winds are expected to retreat back up to the higher elevations
Tuesday evening. High temperatures are forecast to come within
reach of record values (current DIA record is 71F, current
forecast temp is 69F), which gives us a fair shot at tying the
current record if things warm slightly more than expected.

Wednesday will be brought to you by the letter W, for windy, warm,
and winter weather. A plume of Pacific moisture will stream into the
mountains beginning Tuesday afternoon/evening ahead of our next
approaching shortwave. Moderate amounts of new snowfall is expected
across the Front Range Mountains and Mountains of Summit County,
where a Winter Weather Advisory is in place for new snowfall
totals between 5-12 inches will be possible. With a slightly more
favorable flow regime for the Park Range, a winter storm warning
has been issued for where heavier accumulations between 8 and 18
inches are expected through early Thursday morning. With strong
winds around 55 to 65 mph possible, blowing snow will lead to
significantly reduced visibilities, making for very difficult
travel despite snowfall rates generally remaining light. Be
prepared for winter driving conditions if heading into the
mountains from Tuesday evening through early Thursday. Across the
lower elevations, well above-normal temperatures are expected
once again, with gusty winds expanding over much of the plains, as
a 75-80 kt, 500 mb jet drops south over the Wyoming border. Winds
will be strongest along the Wyoming border where 40 to 55 mph
gusts will be possible, with lighter gusts (35-45 mph) from the
Palmer Divide to just north of DIA. It`s looking like there will
be enough moisture to make it off the mountains that relative
humidities should stay above 20% (20- 25%) where winds strongest,
however, if RH were to drop even a little under what is forecast,
conditions would quickly reach critical thresholds, so will still
keep on eye on this to see how hi-res models handle tomorrow`s
conditions to see if any fire weather highlights are needed. A
few light showers will be possible Wednesday evening as QG fields
show some weak upwards motion and a cold front slides south
across the forecast area, though anything that falls will be
light, with the highest PoPs over the Palmer Divide, where
northerly winds behind the front could bring some upslope
conditions.

Warm, windy, and dry conditions will continue on Thursday and
Friday. Despite wind speeds being lighter than Wednesday, RH
looks to drop to 15% or lower across the majority of the plains
both afternoons, which will bring potential for widespread
elevated to critical fire weather conditions both days. Less wind
and slightly cooler temperatures are expected for next weekend
that should ease any fire weather conditions for at least a few
days!

&&

.AVIATION /12Z TAFS through 12Z Wednesday/...
Issued at 435 AM MST Tue Feb 24 2026

VFR through the TAF period, with winds the main concern through
early Wednesday. Drainage flow this morning should turn to the
west-northwest close to 18z. Most likely scenario for this
afternoon looks to be a few channels of stronger (G25-30KT) winds
near the terminals, with light - and perhaps briefly
south/southeast - winds outside those channels. Guidance is
surprisingly consistent in bringing one of those channels through
BJC-DEN through most of the afternoon hours with a little less
confidence for APA.

Winds should turn slowly turn towards southeasterly or drainage
flow by the evening hours with drainage likely continuing
overnight. Sustained/stronger WNW/NW flow is expected to develop
near 18z Wednesday.

&&

.FIRE WEATHER...
Issued at 1134 PM MST Mon Feb 23 2026

Another extended period with elevated to critical fire weather
conditions will persist through Friday. Strong winds are expected
to develop early Tuesday morning along the Front Range Mountains,
with gusts to around 80 mph possible down to elevations around
7,000 feet. RH values will range between 15-25% in areas where
winds are strongest (7,500-8,500 feet in elevation), while lower
RH values, as low as 10% are expected across portions of the
plains, where channels of winds gusting between 35-45 mph will be
possible throughout the afternoon. The RFW has been expanded to
now include Logan County where the latest guidance indicates
critical fire weather conditions are likely to develop.

Gusty winds will continue on Wednesday, but with RH values
improving over Tuesday`s with increasing Pacific moisture entering
the region, RH will range between 20-25% where the strongest winds
are expected to gust between 40-55 mph (generally along and north
of US-34 across the plains), though fire weather conditions will
be elevated across much of the plains due to the strong winds, no
fire highlights are planned at this time.

With continued warm, windy, and dry conditions expected again
Thursday and Friday, critical fire weather concerns will remain
elevated to critical for much of the plains as RH values are
expected to be at or below 15% both days, coinciding with gusty
winds.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning from 6 PM this evening to midnight MST
Wednesday night for COZ031.

High Wind Warning from 8 AM this morning to 6 PM MST this
evening for COZ033>035.

Winter Storm Warning from 8 PM this evening to midnight MST
Wednesday night for COZ033.

Winter Weather Advisory from midnight tonight to midnight MST
Wednesday night for COZ034.

Red Flag Warning from 10 AM this morning to 5 PM MST this
afternoon for COZ215-216-238>240-242-243-248.

&&

$$

UPDATE...Hiris
DISCUSSION...9
AVIATION...Hiris
FIRE WEATHER...9

NWS BOU Office Area Forecast Discussion