National Weather Service Forecast Discussion

Thornton Weather Forecast   
Today's Forecast Story   
654
FXUS65 KBOU 251153
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
453 AM MST Wed Feb 25 2026

.KEY MESSAGES...

- Heavy, wet, mountain snow will continue through Wednesday
  night. The heaviest snow amounts and worst travel conditions
  will be in the Park and Medicine Bow Ranges.

- Critical fire weather conditions Wednesday through Friday.

- Cooler temperatures and another wave of mountain snow possible next
  weekend.


&&

.DISCUSSION /Through Tuesday/...
Issued at 101 AM MST Wed Feb 25 2026

Water vapor imagery shows a plume of Pacific moisture rounding the
upper-level ridge and streaming into Colorado, where our forecast
area remains east of a broad ridge axis, and under northwesterly
flow aloft. Radar and webcams show that snow has started to fall
along the Divide this evening. This snow is expected to continue
through late Wednesday night, becoming heavy at times, warranting
the current winter weather highlights in place across the
mountains. No changes have been made to the current highlights,
though the latest snowfall totals have increased slightly across
the Park Range and Indian Peaks, but with the majority of the zone
that includes the Indian Peaks still below winter storm criteria,
we will keep the advisory as it stands. Just note that we do
expect heavier storm totals in the Indian Peaks of Boulder County
(around 15 to 20 inches of additional snowfall) than across the
rest of the zone, where 8 to 11 inches, with localized heavier
amounts will be possible at the highest elevations. We are also
expecting some pretty impressive snowfall rates overnight tonight
in the Park Range and Indian Peaks (~2"/hr) before they gradually
decrease through tomorrow.

There hasn`t been any significant changes to note in Wednesday`s
wind forecast. A tightening pressure gradient along with a 60-70 kt,
700 mb jet pushing southward into northern Colorado will support
another day of strong winds across much of the forecast area, with
gusts expected to approach, but not quite reach high wind criteria
(58 mph) across the northern plains, before a cold front pushes
south across northern Colorado in the late afternoon/early evening.
These strong winds are still expected to coincide with low relative
humidities throughout the day (near to just above critical
thresholds), bringing widespread critical fire weather conditions
across our lower elevations (more in fire discussion below), where a
Red Flag is in place from 10AM to 6PM. With the passing front and a
jet hanging out overhead, there is a low chance that some of the
plains see a little light precipitation (a few hundredths),
though all of the hi-res models really only show the main area to
see a brief passing shower to be along the Wyoming/Nebraska
borders as the front passes through. Therefore, PoPs were trimmed
back significantly to account for this.

For Thursday, mountain snow should gradually end through the
morning. Across the plains, despite having slightly cooler temps
behind the front, we will have a drier airmass in place that will
increase fire weather concerns. With another windy day expected
across the plains (though lighter winds than Wednesday), RH
values are forecast to drop into the mid-teens across the plains.
We have issued a Fire Weather Watch for much of the lower
elevations (more in fire discussion below).

Friday will be much of the same, more wind and even drier air (RHs
drop into the single digits across portions of the plains). The main
focus will be critical fire weather conditions once again, with
temperatures climbing back up into the mid to upper 60s across the
lower elevations as 700 mb temps warm by about 5-6C.

By Saturday, a surface high over southern Canada looks to start
pushing cold air south towards Colorado. The models typically
struggle to show how far west into Colorado the cold air makes it in
this type of regime, but there is a signal in the ensembles that by
Saturday we see some cooler temperatures start creeping into
northeastern Colorado, and by Monday, afternoon highs across the
plains will finally not reach 60 degrees! Our next shot at
mountain snow will be next weekend, as a shortwave approaches.
There are still many uncertainties within guidance that will need
to be worked out, but between cooler temps and increasing
moisture, there is a chance we see some light snow down here on
the plains by early next week!

&&

.AVIATION /12Z TAFS through 12Z Thursday/...
Issued at 441 AM MST Wed Feb 25 2026

VFR conditions, but gusty winds likely through the day today.
Winds this morning are somewhat variable, but should quickly turn
to the west-northwest by 15-17z. Guidance remains consistent
developing stronger gusts after 18-19z which continue through most
of the afternoon and early evening. BUFKIT profiles still suggest
some mixing potential closer to 45-50kt... and it wouldn`t be
surprising to see a few >45kt gusts at BJC this afternoon. For DEN
and APA, a few gusts around 40kt are possible, mainly between
19-00z. Winds should slowly diminish this evening with a brief
attempt at drainage flow late tonight. West-northwest to northwest
winds again look to develop by late morning Thursday though speeds
will be lighter than today.

&&

.FIRE WEATHER...
Issued at 101 AM MST Wed Feb 25 2026

Strong winds and low relative humidities are expected today,
though RH values will be slightly higher than critical thresholds
for much of the northern portions of the plains, with fuels
remaining very dry and winds expected to gust up to 55 mph, a Red
Flag Warning is in place for all of the plains from 10AM to 6PM
today. A cold front is expected to pass across the forecast area
tonight bringing drier air to the region for Thursday and Friday.
With persistent above-normal temps and winds remaining gusty
across the plains (though much lighter than Wednesday!), with
gusts between 25 to 40 mph expected, we have issued a Fire Weather
Watch for much of the plains for Thursday, as widespread RH
values in the mid-teens are expected. Friday will see similar
windy conditions with even lower RH values (single digits south of
Denver, low teens for the rest of the plains). Saturday will see
improvements to RHs, especially across the northern plains, but
there may still be some elevated to critical fire weather
conditions, though winds are expected to be much lighter in areas
where the RH will be lowest.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until midnight MST tonight for COZ031-033.

Winter Weather Advisory until midnight MST tonight for COZ034.

Red Flag Warning from 10 AM this morning to 6 PM MST this
evening for COZ238>251.

Fire Weather Watch from Thursday morning through Thursday
afternoon for COZ238>240-242>246-248>251.

&&

$$

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

NWS BOU Office Area Forecast Discussion