301
FXUS65 KBOU 010539
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1139 PM MDT Tue Mar 31 2026

.KEY MESSAGES...

- Mountain snow will continue through Wednesday evening, with
  some travel impacts for higher passes during heaver snow later
  in the day/evening.

- Numerous rain showers on the plains this afternoon and evening.
  Isolated thunderstorm or two possible. Still mainly light
  precipitation amounts.

- A brief warm up on Thursday, with potential for locally critical
  fire weather conditions.

- Windy and cooler Friday with another round of snow for the
  mountains. Plains look to be dry (80% confidence).

&&

.DISCUSSION /Through Tuesday/...
Issued at 1138 PM MDT Tue Mar 31 2026

Satellite shows a large plume of deepening moisture across the
western U.S. for a change...something we have seen very little of
this winter season and early spring. Integrated water vapor
transport (IVT) was more than impressive, reaching 6-8 standardized
anomalies when compared to climatology. In other words, this is
extremely rare event for this time of year (but also attributable
to the unseasonably warm airmass able to hold more water than
typical). At any rate, the bulk of this moisture plume will set
its sights on the mountains of western and southern Colorado,
with the northern mountains being more sheltered in southwest flow
aloft. There is still moderate synoptic scale lift and slight
instability ahead of the trough moving across the Great Basin.
Therefore, we still expect several inches of wet snow for the
mountain areas and thus a continuation of the Winter Weather
Advisory for the northern mountains above 9,000 feet. Locally a
foot or more is expected in the Park Range north of Rabbit Ears
Pass. Much of the Colorado mountains will finally benefit from a
high water content precipitation event, and the snowpack could use
every drop/flake it sees. Meanwhile, mountain valleys will
likely see a rain or rain/snow mix for this event, changing over
to all snow late this afternoon and evening as the upper level
trough and cold front arrive. While there may be a brief burst of
convective snow for the high country with this feature, there is
rather pronounced drying behind it so expect snow to decrease by
late evening, with only scattered lighter showers lingering in the
high country overnight.

On the plains, we`ll be fighting deep downslope flow for most of
this period so a significant precipitation event is not expected.
But by afternoon, surface cyclogenesis occurs along the Palmer
Divide into southeast Colorado, limiting our downslope component
and perhaps just enough to bring a brief period of shallow
upslope. At the same time, the better dynamics will be arriving
ahead of the upper level trough, and combined with weak
instability and abundant mid/upper level moisture we still expect
a round of showers/isolated thunderstorms to develop along the
Front Range/I-25 Corridor and move northeast across the plains
through the evening. While most of these will be light, the
convective and rich moisture components will allow a few
showers/isolated storms to produce a brief period of moderate to
heavy rain. Ensembles are still consistent that most areas will
only average 0.05-0.20 inch across the I-25 Corridor, but the
isolated heavier showers could put down 0.3 or 0.4 inch. Those
amounts will increase as you travel northeast across the plains
where the rain showers are expected to last longer into the
evening as the storm system intensifies in the Central Plains. A
few spots over the northeast plains could see a half inch (30-50%
chance) east of Sterling and Akron.

Behind this storm system, there will be a sharp but short break
Thursday. That break will feature flat ridging and lee troughing,
so expect breezy conditions and a quick warmup back to above
normal temperatures. With that, depending on how much
precipitation occurs tonight, fire weather conditions may be
ramping up again. The most prone areas would be south and
southeast of Denver across the Palmer Divide and adjacent plains.
However, with possibility of rainfall we`ll keep the existing fire
Weather Watch confined to eastern Elbert and Lincoln Counties
where less precipitation and more wind/lower RH is expected.

The next weather disturbance arrives by Thursday night. It`s
almost unanimous now that the center of the upper low tracks well
to our north through Wyoming, meaning strong westerly flow aloft,
mountain snow, and mainly dry weather for the plains. It will
also be turning colder and windy with strong low/mid level
gradients expected. Thus, there is potential for more fire weather
concerns for the lower elevations on Friday. Temperatures will
also be colder in the mountains, so despite less snowfall we do
anticipate more travel impacts for the high country Thursday night
potentially lingering through Friday.

For the weekend into early next week, ensembles suggest mainly dry
weather and gradual warming. However, we will be open to backdoor
cold fronts so one or two of those days should be cooler.

&&

.AVIATION /06Z TAFS through 06Z Thursday/...
Issued at 1138 PM MDT Tue Mar 31 2026

Winds will increase out of the south over the next couple of hours
with gusts to around 25 knots. This will lead to the development of
a Denver cyclone. Winds at DEN and APA are expected to turn to the
north to northwest 11-13Z as the cyclone shifts eastward. Location
and timing of the cyclones are usually tricky, leading to a lower
confidence forecast. Northwest to north winds are expected to
continue into the afternoon and early evening hours (18-02Z), though
outflow from convection could disrupt this pattern. Towards 06Z
Thursday, winds transisition to a southerly drainage direction.

Lift from the upper level system will move across eastern Colorado,
including the Denver area after 18Z. Scattered to numerous showers
are expected to form after 19-20Z with a few weak thunderstorms also
possible. Ceilings are expect to fall to around 5000 feet under the
showers/storms. Threat rain begins to decrease after 00Z Thursday.
Clouds start to scattered after 06Z with mostly clear skies expected
by 12Z Thursday.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 9 PM MDT Wednesday for COZ031-033-
034.

Fire Weather Watch from Thursday afternoon through Thursday
evening for COZ246-247.

&&

$$

DISCUSSION...20
AVIATION...12

NWS BOU Office Area Forecast Discussion