397
FXUS65 KBOU 231127
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
527 AM MDT Sun Mar 23 2025

.KEY MESSAGES...

- Breezy conditions today for the mountains/northern plains, with
  elevated to near-critical fire weather conditions.

- Strong winds will impact the mountains, foothills and adjacent
  lower elevations tonight into early Monday morning with gusts
  55-70 mph expected.

- Mainly dry weather expected Tuesday through Thursday, with near
  record temperatures likely by Thursday.

- Cooler with a chance of precipitation late Friday and Saturday.

&&

.SHORT TERM /Through Tonight/...
Issued at 215 AM MDT Sun Mar 23 2025

Snow showers are hanging on along and just east of the
Continental Divide early this morning under the trailing right
entrance region of the departing jet, but will largely end by
sunrise as moisture gets compressed into a shallow near-surface
layer and QG subsidence increases.

Robust northwest flow on the southern periphery of the jet will
sustain gusty winds in the high country and northern plains in
particular, with another moderately dry day in store for the lower
elevations leading to widespread elevated fire weather conditions,
and near-critical conditions in our northeast plains. Red Flag
criteria could be met for an hour or two in our northeast corner,
but such conditions aren`t likely to be prolonged enough to
warrant any headlines. Temperatures will run a few degrees cooler
than yesterday behind the overnight front.

Tonight, a weak disturbance most evident at the 700mb level will
clip northern portions of the forecast area, with increasing
northwest flow aloft and slightly deeper mid-level moisture. These
ingredients would be enough to produce some orographically-forced
snow showers focused primarily over our northern mountains, so
have increased PoPs for this timeframe. This feature will also
strengthen cross-barrier flow to around 40 kts overnight, with a
pronounced stable layer developing after midnight and aiding in
development of stronger gusts of 55-70 mph for favored wind-prone
locations in the lee of the mountains and foothills, especially
in/around Boulder, Gilpin and northern Jefferson Counties.
Locations near the base of the foothills will see a notably milder
night given compressional warming, with lows remaining in the
40`s.

&&

.LONG TERM /Monday through Saturday/...
Issued at 215 AM MDT Sun Mar 23 2025

Rather brisk northwest flow aloft will hold over the region for
one more day on Monday. Then the flow will relax with upper level
ridging building in Tuesday through Thursday. We`re still on
track for a change late in the week.

For Monday, strong, gusty winds and a mountain wave will continue
for the Front Range foothills and nearby adjacent plains including
Highway 93 between Boulder and Golden. Peak gusts of 60 mph or
more early in the morning should slowly abate during the day as
the mountain top stable layer weakens. At the same time, daytime
heating and mixing will allow the gusty winds to spread east
across much of the plains, but at a lesser intensity (30-35 mph).
That will support at least elevated fire weather conditions.
However, humidities should only bottom out near 20% despite the
warmer temperatures, as models support enough mid level moisture
advection. Speaking of which, that moisture will keep a chance of
light snow showers or flurries in the mountains for another day,
but essentially no accumulation. Warm advection combined with
downslope flow will support high temperatures pushing 70F across
the plains.

Tuesday won`t see much change in temperatures, as a weak backdoor
cool front late Monday night balances a little warm advection and
ridging aloft. Winds will be lighter as pressure gradients relax.

The warmup will resume Wednesday and continue into Thursday.
Thursday is still shaping up to be the warmest day of the coming
week, with highs pushing 80F across the plains and I-25 Corridor,
which would be at or near record warmth for the date. Models are
indicating a little moisture now, perhaps just enough to generate
a light pm shower over the higher terrain.

Looking ahead to the end of the week, there was a notable slowing
in the ensembles, now suggesting the next trough to arrive
Saturday. Therefore, ensembles are now in better agreement of
the warmer than normal weather persisting into Friday. Winds
should also pick up the day before the trough arrives, so fire
weather conditions may become a concern again toward Friday. For
Saturday`s system, the vast majority of models are too warm and
too far north for significant precipitation or snowfall, with
only a few members showing a colder and more favorable southern
track. At this time, those are definitely in the minority (10-15%
chance), and the pattern still remains too progressive and similar
to other storm systems this month.

&&

.AVIATION /12Z TAFS through 12Z Monday/...
Issued at 523 AM MDT Sun Mar 23 2025

All terminals VFR thru TAF period. Weak anticyclone this AM will
promote mostly SE flow w/ occsnl VRB directions possible.
Prevailing wind will become WNW this PM starting 20-21Z, w/ gusts
mostly 11-17 kts. For KDEN/KAPA, expect wind to back this evening
to lighter S/SW drainage. Mtn wave development tonight will lead
to strengthening W winds between 07-12Z at KBJC and increased
LLWS, especially W of I-25.

&&

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

&&

$$

SHORT TERM...Rodriguez
LONG TERM...Barjenbruch
AVIATION...Rodriguez