257
FXUS65 KBOU 172025
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
225 PM MDT Fri Oct 17 2025

.KEY MESSAGES...

- Cold front Saturday to bring cooler and windy weather, with
  elevated to near-critical fire weather conditions possible.

- Warmer Sunday with a slight reprieve in winds, but drier
  conditions will keep fire danger high for lower elevations.

- Another front will bring more strong winds Monday and cooler
  temperatures once more, along with potential for a few mountain
  snow showers. High fire danger continues.

- Lighter winds starting Tuesday, with more seasonal temperatures
  expected.

&&

.DISCUSSION /Through Friday/...
Issued at 151 PM MDT Fri Oct 17 2025

It`s rather tranquil today as we await the arrival Saturday`s
front. In the meantime, modest downslope flow as well as a little
elevated cloud cover will keep temperatures milder tonight east of
the mountains. Speaking of mountains, they`ll see a gradual
increase in winds overnight as the next trough continues its
encroachment into the Rockies, and the windier locations will see
gusts approaching 50 mph by daybreak Saturday.

The cold front will enter our northern tier of counties mid-
morning, spreading south through early afternoon, and packing a
notable punch when it comes to winds, producing gusts 30-35 mph
for the urban corridor, and 35-45 mph over the plains. Moisture
will be limited considering the northerly track, but under
northwest flow and with robust frontogenesis, there will still be
an opportunity for some snow and rain showers for our northern
mountains and the Cheyenne Ridge respectively. Any accumulations
shouldn`t amount to much more than a dusting to at most 1" in the
mountains. Foothill-adjacent areas roughly west of I-25 may see
near-critical fire weather conditions Saturday too, in spite of
the cooler temperatures...the northeast plains are expected to
remain the 50`s throughout the day, with only portions of the
urban corridor and the southern plains having a shot at breaking
into the 60`s.

Our first widespread freeze of the season is slated for Saturday
night following the frontal passage. All but a few locations
around the Denver metro and closer to the foothills look to fall
to or below the freezing mark, with patchy killing freeze
potential for the coldest plains locations which could fall to
around 26-28F. A Freeze Watch has been posted for the areas of
greater confidence.

Sunday brings a pause in the cooler weather as rising heights push
temperatures up into the mid to locally upper 70`s once again,
with low humidity in place. Surface winds will be notably weaker
beneath the ridge, however we`ll retain quite healthy mid-level
flow that should be able to mix down for a few hours in the
afternoon - enough to warrant a localized Fire Weather Watch for
parts of the urban corridor, foothills and Palmer Divide. There
won`t be much of a reprieve over the higher terrain however, where
40-50 mph gusts will continue.

The forecast hasn`t changed much as head into early next week.
Sunday`s ridge is quickly replaced by another fast-moving trough
and robust surface front on Monday, providing another surge of
strong winds to all of northeast Colorado, and an opportunity for
a few more snow showers predominantly in our northern mountains.
Once more, moisture will be a limiting factor, and the moderation
in humidity may not be sufficient to prevent development of
locally critical fire weather conditions east of the mountains. It
looks to be a rinse and repeat situation for temperatures as well,
with another widespread freeze favored for Monday night following
the front.

Fortunately, winds looks to taper off Tuesday onward as we
transition to a more zonal flow pattern aloft. Tuesday appears dry
with seasonal temperatures, before a chance (20-40%) of
precipitation returns Wednesday in association with an approaching
closed low near the Four Corners.

&&

.AVIATION /18Z TAFS through 18Z Saturday/...
Issued at 1131 AM MDT Fri Oct 17 2025

VFR conditions will persist through Saturday morning. Typical
light wind pattern expected to continue through the day at DEN
with winds becoming northeast 19-21Z, then slowly turning to the
southeast after 00Z, then southerly by 05-06Z. Stronger winds
will be possible at BJC tonight after 04-05Z with gusts reaching
25 knots or slightly stronger.

The next concern will be a cold front which arrives late Saturday
morning. While no precipitation or low clouds are expected, we
will likely (70-80% chance) see a blast of strong, gusty northerly
winds. We expect those to increase 16Z-18Z with potential gusts
to 30-35 kts behind the front.

&&

.FIRE WEATHER...
Issued at 151 PM MDT Fri Oct 17 2025

Almost all of our lower elevations will see widespread elevated to
near-critical fire weather conditions this weekend and into
Monday, driven by strong winds Saturday and Monday, and dry
conditions on Sunday. Alignment of wind and humidity thresholds
remains somewhat questionable for many areas however, which
complicates the potential issuance of any headlines.

Saturday, the primary concern lies with areas along the urban
corridor, where humidity should be less affected by the frontal
push. Locally critical conditions can`t be ruled out if humidity
approaches 15%, as winds will be well above criteria.

Humidity is much less marginal for Sunday, with most areas below
7,000-8,000 ft expected to fall below 15% in the afternoon.
Winds, however, will be weaker compared to other days.
Nonetheless, mixing should be sufficient in the afternoon to allow
for at least a few fingers of gustier winds 25-30 mph to develop
within the Fire Weather Watch. Just how prolonged or extensive
these conditions will be though is much less certain.

Finally, Monday will bring perhaps the strongest surge of frontal
winds to the region, with gusts in excess of 35-45 mph being
common for both the urban corridor and plains. Even with a slight
moderation in humidity levels, wind speeds alone may end up
supporting highlights assuming no significant trends in the
moisture forecast.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch Sunday afternoon for COZ216-239-241-246-247.

Freeze Watch from Saturday evening through Sunday morning for
COZ038-041>051.

Frost Advisory from 10 PM Saturday to 8 AM MDT Sunday for COZ039-
040.

&&

$$

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