540
FXUS65 KBOU 111528
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
828 AM MST Thu Dec 11 2025

.KEY MESSAGES...

- Strong winds will continue along the Front Range mountains and
  foothills through midday today. Gusts will be between 70-80 mph.

- An extended period of dry and mild weather will last through the
  middle of next week, with well above normal temperatures
  expected.


&&

.UPDATE...
Issued at 817 AM MST Thu Dec 11 2025

The decision was made to issue a Red Flag Warning for the lower
foothills, I-25 Corridor and adjacent plains through 5 PM today.
Current surface observations show widespread relative humidity
values already reaching critical thresholds, as downsloping winds
have allowed ample mixing across the foothills. Even if RH values
remain marginal this afternoon (>15% RH), wind gusts up to 40-50
mph will support red flag conditions.

&&

.SHORT TERM /Through Thursday/...
Issued at 256 PM MST Wed Dec 10 2025

Current surface observations across the high country show wind gusts
up to 70 mph, with gusts up to 50 mph (aside from an isolated gust
up to 68 near the Rocky Flats) across the wind-prone areas along the
foothills. While we haven`t met high wind criteria yet, we do expect
the winds to peak later this afternoon and into the evening.

SPC upper air analysis shows northwest flow aloft, with Colorado
generally being in the right exit region of the jet stream.
Modeled cross-sections have a decent ridgetop stable layer as well
as a wave induced critical layer for this afternoon/evening. In
addition, surface pressure gradients between Grand Junction and
Denver will likely increase to 11-14 mb. With these ingredients,
we do expect winds to gust up to 80 mph periodically across the
high country. High resolution models have consistently been
indicating channels of winds along the foothills and adjacent
plains, so expect isolated wind gusts up to 55 mph through the
evening. Overnight Wednesday, there will be a brief lull in strong
winds before it could pick up again Thursday morning, as cross-
sections indicate another critical layer forming. For this reason,
still expect High Wind Warning to continue till 11 AM Thursday
morning. However, if guidance changes this evening/overnight, the
warning could expire earlier.

Due to continuous downsloping winds, Thursday morning low
temperatures will be above normal. Across the plains, expect to wake
up to temperatures between high 30s and mid 40s. Denver`s record
warmest minimum temperature for December 11th is 44 degrees (set in
1933) and our current forecasted low is 43. We will keep any eye out
for any record-breaking minimum temperatures. The warming trend
will continue throughout the day Thursday, as breezy northwest
winds (gusting up to 45 mph a times) will aid in compressional
heating and allow temperatures to reach the mid-to-high 60s across
the plains (~20 degrees above normal!). Other than that, dry
conditions will prevail for the forecast area.

&&

.LONG TERM /Thursday night through Wednesday/...
Issued at 256 PM MST Wed Dec 10 2025

Pressure gradients will continue to slacken Thursday night, bringing
significant improvements to windy conditions across the mountains
and foothills through the overnight hours. An anomalous surface high
(2.4 - 3.1 sigma above normal) over western Canada will start to
usher arctic air into the northern US. This will be the main area of
uncertainty for the extended period, as the northern corner of
Colorado is situated along the temperature gradient, with Colorado
being on the warmer extent of the cold air. If the cold air pushes
just slightly southward, temperatures across the far northeast
plains could be 5-10 degrees colder than what is in the current
forecast, though the extreme cold temperatures are not expected to
make it into Colorado. The coldest temperatures are expected
overnight Saturday into Sunday, and though there is around a 6
degree spread between ensemble means, temps are forecast to drop
into the teens for locations along the Nebraska border. While
temperatures will be colder over the northeastern plains, well
above normal temperatures are expected across the forecast area
through the period, with afternoon high temperatures forecast to
reach the upper 50s/low 60s along the urban corridor each day.

Persistent northwesterly flow on the eastern side of upper level
ridging will remain in place for the majority of the extended
period. Despite the influx of Pacific moisture pumping into the
Pacific Northwest over the coming days, Colorado will remain too
far south to reap any benefits. Ensembles show widespread dry
conditions are expected through the weekend, with only some light
snowfall potential for the mountains towards the tail end of the
forecast period. The ridge is expected to gradually shift eastward
early next week, and ensembles are still holding onto a weak
shortwave traversing the region around Monday/Tuesday, though
they still show slight discrepancies on strength and timing.

&&

.AVIATION /12Z TAFS through 12Z Friday/...
Issued at 437 AM MST Thu Dec 11 2025

VFR conditions are expected through the TAF period. DEN winds have
been predominantly westerly overnight tonight and that should
continue into the mid morning hours. Speeds will vary greatly with
periods of gusts to 25 knots and periods where winds decrease to 6
knots. APA is expected to have light westerly winds for most of
the morning.

BJC has had strong winds for most of the night and those winds may
just continue for the rest of the day. Gusts between 40-45 knots
will be common although the mountain wave rotor will break down
from time to time and winds will be light with speeds less than
10 knots at different points throughout the day.

Winds will pick back up during the mid to late morning at DEN and
APA. Gusts could reach 38 knots at DEN and 30 knots at APA.
However, there may be periods of lighter winds throughout the
day.

West winds will continue into the evening hours before turning
more southwesterly by the late evening. A cold front is expected
to move through the terminals between 07-10Z tonight with
northeast winds behind it. West winds will build back in by the
late morning on Friday over all terminals.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
High Wind Warning until 11 AM MST this morning for COZ033>035.

Red Flag Warning until 5 PM MST this afternoon for COZ216-
238>243-245>247.

&&

$$

UPDATE...MAI
SHORT TERM...MAI
LONG TERM...9
AVIATION...Danielson