016
FXUS65 KBOU 151153
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
553 AM MDT Sat Mar 15 2025

.KEY MESSAGES...

- Another round of mountain snow showers today, with light
  accumulations expected.

- Warmer/drier Sunday and Monday with near critical fire weather
  conditions especially in and near the foothills Monday
  afternoon.

- A winter storm will bring snow to the mountains beginning
  Tuesday, with snow likely (50-80%) for the lower elevations
  Tuesday night.

&&

.SHORT TERM /Through Tonight/...
Issued at 435 AM MDT Sat Mar 15 2025

Current satellite imagery shows yesterday`s fast moving wind maker
has turned into quite a stunning mid-latitude cyclone. The center of
rotation has already made its way into southeastern Minnesota late
tonight. While associated severe storms with potential long track
tornadoes will wreck havoc across the Central Gulf states and
Tennessee Valley Region through the day today, impacts in
Colorado will continue to diminish through the morning, as surface
pressure climbs and pressure gradients slacken.

Within the WNW flow aloft, enough moisture will continue to usher
into the mountains to keep favorable conditions in place for
orographic snow showers throughout the day. Steepening lapse rates
will increase instability in the afternoon hours leading to some
increased snowfall rates including along the I-70 mountain corridor,
with some light accumulations potentially pushing into the southern
Front Range Foothills. Overall, accumulations will be light with
around 2-4" expected through the day, with the highest elevations
seeing slightly more, and less than an inch for the mountain
valleys.

Across the plains, high temperatures will be in the upper 40s to
mid 50s. Moisture will increase in the mid-levels as mountain
showers push eastward and a few virga showers slide across the
plains. With dry lower levels in place, any precipitation that
falls is not expected to reach the ground.

For tonight, we will see increasing NW flow aloft as an upper ridge
begins to push over the region. The NW flow could still support some
light orographic snowfall through the overnight hours. Clearing
skies across the plains will allow temperatures to cool into the
20s. Enough clearing is likely just before sunrise to allow our
mountain valleys to drop into the teens. Cross-sections show
potential for mountain wave development near sunrise Sunday
morning.

&&

.LONG TERM /Sunday through Friday/...
Issued at 435 AM MDT Sat Mar 15 2025

We`ll have strong warm advection Sunday and Sunday night, but
only a brief window of favorable conditions for mountain wave
amplification late Sunday. Otherwise, the flow will be pretty
sheared and the temperature profile will be warming fairly
equally. This still looks like a long period of windy conditions
(30-50 mph gusts) for the ridges and east slopes, but the threat
of 50-70 mph gusts looks confined to late afternoon and evening
Sunday for the Front Range ridges, higher east slopes, and wave
prone spots.

Forecast temperatures are looking good with about 10 degrees of
warming Sunday and 10 more on Monday. We`re a bit above guidance
for the lows and that`s probably alright with a steady breeze in
most places.

Models are in better agreement with the Tuesday system. The
operational GFS is still a little faster, but now only about 6
hours. It has the frontal band with strong cooling and rain/snow
during the day, while the operational EC is mostly in the evening.
EC ensembles though are spread across this time range with quite a
few being as quick as the operational GFS. We`ll show temperatures
cooling from the 50s into the 40s in the afternoon, but it may not
get that warm if the system is a little faster. The QPF looks to
be enough for an inch or two of snow where it`s cold enough
(probably the I-25 corridor/Palmer Divide), with less certainty
about amounts and precip type across the rest of the plains.
Bigger accumulations are looking less likely, but a quick shot of
heavy showers behind the front especially in the upslope south of
Denver is still a possibility. There will likely be advisory level
impacts in the mountains. All of this is limited by a fairly fast
motion of the system, so the significant precipitation may be
limited to 6-8 hours.

On Wednesday, the trough is exiting with pretty quick drying,
though there will likely be some lingering orographic snow in the
mountains at least in the morning. We`ve got a ridge for Thursday,
then another trough for Friday which also has better model
agreement tonight. Once again, the highs will depend on frontal
timing. This system looks less dynamic and in a drier environment.
NBM likelys for the mountains and low PoPs for the plains look
appropriate.

&&

.AVIATION /12Z TAFS through 12Z Sunday/...
Issued at 540 AM MDT Sat Mar 15 2025

VFR conditions expected through the TAF period. Winds are tricky
today as passing virga showers this afternoon may lead to gusty
outflows over the TAF sites. Have introduced a TEMPO to account
for the most likely timing this afternoon. As the virga showers
are expected to be high based, ceilings look to remain above 090
at KDEN/KAPA with potential to drop slightly lower (080) for KBJC,
but will remain above thresholds. Winds will turn to the west for
the overnight hours with some uncertainties remaining for wind
speeds and directions early Sunday morning as a potential mountain
wave develops over the Front Range.

&&

.FIRE WEATHER...
Issued at 435 AM MDT Sat Mar 15 2025

Dry and breezy conditions are expected for Sunday and Monday. It`s
looking more like the Front Range mountain wave will be keeping
the strongest winds in and near the foothills, with some momentum
spilling onto the plains south of Denver. These areas will have
conditions near Red Flag criteria for a few hours Sunday
afternoon, and then it will be warmer and maybe a little windier
on Monday afternoon. Models may be underdoing conditions a bit on
Monday, having dew points in the teens looks a bit suspect given
the dryness aloft.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SHORT TERM...Bonner
LONG TERM...Gimmestad
AVIATION...Bonner
FIRE WEATHER...Gimmestad