511
FXUS65 KBOU 040917
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
317 AM MDT Sat May 4 2024

.KEY MESSAGES...

- A few showers and storms across the eastern plains this
  afternoon into tonight.

- Warmer and windy on Sunday.

- Periods of snow showers in the mountains late Sunday night
  through mid week. There could be travel impacts for the Monday
  morning commute along the I-70 Mountain Corridor.

- Highs winds possible in the mountains and foothills Monday into
  Tuesday.

- Across the plains, expect very windy conditions Monday and
  Tuesday with critical fire conditions across southeast Elbert
  and southern Lincoln counties.

&&

.SHORT TERM /Through tonight/...
Issued at 243 AM MDT Sat May 4 2024

GOES-18 CIRA Geocolor displays mostly clear skies this morning with
a few lingering low clouds along the urban corridor. This should
quickly dissipate this morning. A short-term upper level ridge
pattern will occur over northeastern Colorado today. Surface CAPE
values remain weak less than 100 J/kg and focused near areas south I-
70 this afternoon. Without much forcing and meager mid-level
moisture, isolated to scattered showers are possible through this
evening mainly for South Park and the southern foothills. Any
isolated thunderstorm that develops should remain non-severe.
Partly cloudy skies are expected by late afternoon. High
temperatures sit near normal today. This evening, southeasterly
flow increases across the plains. Winds could produce wind gusts
up to 35 mph overnight tonight.

&&

.LONG TERM /Sunday through Friday/...
Issued at 243 AM MDT Sat May 4 2024

A storm system will move into the Great Basin on Sun with increasing
SW flow aloft. Meanwhile, sfc low pres will intensify from
central WY into ern CO, with stg SSE low level flow across the
plains. This will lead to very windy conditions over the plains
with gusts up to 50 mph thru the aftn. As far as precip chances,
there will be some instability in the aftn to produce widely sct
showers over the higher terrain. Across the plains, there will be
a capping inversion which will inhibit tstm development. Highs
will be warmer on Sun as readings rise into the mid to upper 70s
across most of the plains. The only exception will be over the far
ern areas where readings may only reach the upper 60s.

For Sun night into Mon, the storm system will move quickly ENE into
ern WY by Mon aftn.  There will be a decent shot of QG ascent ahead
of the system late Sun night into early Mon. Thus this will bring
a round of snow especially to the nrn mtns north of I-70 with
advisory amounts possible. Elsewhere, as the main shot of QG
ascent moves across the plains Mon morning there will be a a chc
of showers and possibly a tstm. Meanwhile, rather stg downward
descent will quickly spread across the area by midday with a mtn
wave developing. Cross-barrier flow will increase to 50 kts by
late morning into the aftn hours, so there will be a potential
for high winds across the mtns and foothills. Across the plains, a
bora type front will move across by midday with very windy
conditions thru the aftn hours as well. As far as highs, readings
will drop back in the lower to mid 60s across nern CO.

Looking ahead to Mon night into Tue, a strong storm system will be
over the nrn Plains with rather stg WNW flow aloft over the area.
Cross-sections show moisture increasing overnight in the mtns so
there will likely be additional orographic snowfall thru Tue. Across
the plains, it will remain dry and windy with highs in the 60s. Once
again there will be some potential for high winds Mon night in the
mtns and foothills as cross-barrier flow remains around 50 kts.

By Tue night into Wed, the storm system will remain over the nrn
high Plains with a disturbance moving across. Thus, will continue
to see a good chc of snow in the mtns. Across the plains, will
keep in a slight chc of showers on Wed.

For Wed night into Thu, the storm system over the nrn Plains is fcst
to split as one piece of energy moves ESE while another piece moves
across the area.  In addition, a secondary shot of cooler air will
move into the region as well.  Overall, not sure how all of this
will evolve this far out, but have maintained a chc of precip across
much of the area on Thu with below normal temps.

On Fri, based on current data, it appears a cool an unsettled
pattern will remain in place as a weak upper level trough
continues across the area.

&&

.AVIATION /06Z TAFS through 06Z Sunday/...
Issued at 1134 PM MDT Fri May 3 2024

VFR conditions are expected through the TAF period.
Southeast winds should continue through Saturday afternoon.
Scattered showers will occur west of all terminals along the
higher terrain, but it is possible a shower or two could spread
into KBJC by Saturday evening. Models have favored this outcome
thus including a VCSH between 00-02Z. There is lower confidence in
this outcome for KAPA and KDEN due to unfavorable conditions for
thunderstorm development thus kept it out of the TAF for now.
Additionally, winds increase this afternoon gusting between
20-27kts briefly from 21-22Z until 00Z. Drainage winds are
unlikely by Saturday night and should remain south.

&&

.FIRE WEATHER...
Issued at 243 AM MDT Sat May 4 2024

Winds will increase across the plains on Sunday with gusts up
to 50 mph, however humidity levels will be above 20%.  For
Monday and Tuesday, very windy conditions will continue across
the plains. The most likely area for critical fire conditions
will be over southeast Elbert and southern Lincoln counties.

&&

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

&&

$$

SHORT TERM...AD
LONG TERM...RPK
AVIATION...AD
FIRE WEATHER...RPK