National Weather Service Forecast Discussion

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324
FXUS65 KBOU 252045
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
245 PM MDT Sat Apr 25 2026

.KEY MESSAGES...

- Cooler, more moist weather pattern expected for much of the next
  week. Primarily light precipitation amounts, with the exception
  of some heavier rain under thunderstorms.

&&

.DISCUSSION /Through Saturday/...
Issued at 159 PM MDT Sat Apr 25 2026

Temperatures this afternoon are 10 to 30 degrees cooler compared
to this time yesterday. This combined with dewpoints around 10 to
20 degrees higher than yesterday has increased RHs enough to end
our string of critical fire weather days. Weak upslope flow will
be present this afternoon as surface winds turn more easterly over
the plains and winds stay out of the west/southwest in the
mountains. This will lead to isolated to scattered showers this
afternoon. However, precip chances and amounts will stay on the
lower end this afternoon due to the lack of a strong forcing and
moisture.

Precipitation chances on Sunday look more promising. Southerly
surface winds will bring in moisture at the surface, while
southwesterly mid level winds will bring in moisture from the
Pacific. This will bring PWATs to around 150% to 200% of normal by
Sunday afternoon. Aloft, a shortwave is expected to move over the
area, providing upper level lift. Models are showing a surface
low forming near our area in the afternoon as well, which will
provide surface convergence and act as a focal point for
convective development. Instability looks decent enough (SBCAPEs
~300 to 800) for a few thunderstorms in the afternoon, potentially
even an isolated strong to severe storm. Main hazards will be
strong winds, dangerous lightning, and small hail. Rain amounts
tomorrow will generally be in the trace to around 0.5 inch range,
however localized areas under thunderstorms could see higher
amounts. The best chance for higher rain amounts will be in our
northeast Colorado plains. In the mountains, snow is likely for
areas above 8,500ft, with most areas seeing around 1 to 6 inches.
Roads could be slick at times in the mountains Sunday afternoon
into Sunday night.

Another cold front is expected to move through the area early
Monday. Behind the front, we`ll see breezy N/NW winds, with gusts
around 30 to 45mph. As we go into the afternoon, winds will start to
turn more to the northeast in the plains adjacent to the foothills,
providing some decent upslope. This could be enough to trigger a few
showers and storms over the Foothills, which would then progress
east into the late afternoon and evening. However, QG subsidence
behind the departing shortwave may try and hinder precip
development.

Another shortwave is expected to move over the area sometime late
Monday through mid Tuesday. The lift associated with this
disturbance will provide low to medium chances for additional
showers during this time period. Periods of isolated showers will
be possible for mid next week as we remain in this unsettled
pattern. However, models do not have good agreement on the extent
and timing of said precip. The best chances for precip across our
area will be Sunday and Monday into Tuesday with decreasing
confidence as we go later into the week. The upper level system on
Thursday into Friday continues to progress southward and a bit
slower. This gives us a glancing blow from the low, giving us some
hope for additional precip, but overall chances look much better
to our south.

&&

.AVIATION /18Z TAFS through 18Z Sunday/...
Issued at 1255 PM MDT Sat Apr 25 2026

Low ceilings have lifted at all three airports and VFR conditions
are currently in place. Current observations show that winds are
primarily from the E-NE at KDEN, while KBJC and KAPA are light and
variable. However, we expect winds to become easterly across the
region this afternoon. This easterly flow will bring the chance for
a few light high-based showers later this afternoon as moisture
continues to be transported into the region.

There is relatively high confidence (70% chance) that ceilings will
lower to around 1000ft at all airports in a window between 07Z and
14Z in the early morning hours. We decided to introduce a TEMPO for
600-800ft ceilings at KDEN and KBJC.

Winds will be a bit tricky tomorrow as they will likely start out
light and variable before a lee-side cyclone forms just east of the
Denver metro area, shifts east into the plains, and strengthens.
Additionally, this cyclone will aid in the formation of isolated
thunderstorms and scattered showers which will also provide wind
variability due to gusty outflows and microbursts. The timing of
thunderstorm activity will likely be between 19Z and 23Z Sunday,
but light showers and outflows may linger into the early evening
hours.

&&

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

&&

$$

DISCUSSION...AP
AVIATION...AA

NWS BOU Office Area Forecast Discussion